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21 pages, 3375 KiB  
Article
Obesity as Inducer of Cognitive Function Decline via Dysbiosis of Gut Microbiota in Rats
by Hoda B. Mabrok, Asmaa A. Ramadan, Ibrahim M. Hamed and Doha A. Mohamed
Brain Sci. 2024, 14(8), 807; https://doi.org/10.3390/brainsci14080807 (registering DOI) - 12 Aug 2024
Abstract
Diet-induced obesity is a global phenomenon that affects the population worldwide with manifestations at both the phenotypic and genotypic levels. Cognitive function decline is a major global health challenge. The relation between obesity and cognitive function is a debatable issue. The main goal [...] Read more.
Diet-induced obesity is a global phenomenon that affects the population worldwide with manifestations at both the phenotypic and genotypic levels. Cognitive function decline is a major global health challenge. The relation between obesity and cognitive function is a debatable issue. The main goal of the current research was to study the implications of obesity on cognitive function and gut microbiota diversity and its impact on plasma and brain metabolic parameters in rats. Obesity was induced in rats by feeding on a high-fat (HF) or a high-fat/high-sucrose (HFHS) diet. The results reveal that both the HF (0.683) and HFHS (0.688) diets were effective as obesity inducers, which was confirmed by a significant increase in the body mass index (BMI). Both diet groups showed dyslipidemia and elevation of oxidative stress, insulin resistance (IR), and inflammatory markers with alterations in liver and kidney functions. Obesity led to a reduction in cognitive function through a reduction in short-term memory by 23.8% and 30.7% in the rats fed HF and HFHS diets, respectively, and learning capacity and visuo-spatial memory reduced by 8.9 and 9.7 s in the rats fed an HF or HFHS diet, respectively. Bacteroidetes, Firmicutes, Proteobacteria, Fusobacteria, and Spirochaetes phyla were detected. The Firmicutes/Bacteroidetes ratio (F/B) significantly decreased in the HF group, while it increased in the HFHS group compared to the normal control. The two species, Bacteroides acidifaciens and Bacteroides ovatus, which are associated with IR, were drastically compromised by the high-fat/high-sucrose diet. Some species that have been linked to reduced inflammation showed a sharp decrease in the HFHS group, while Prevotella copri, which is linked to carbohydrate metabolism, was highly enriched. In conclusion: Obesity led to cognitive impairment through changes in short-term and visuo-spatial memory. A metagenomic analysis revealed alterations in the abundance of some microbial taxa associated with obesity, inflammation, and insulin resistance in the HF and HFHS groups. Full article
(This article belongs to the Section Nutritional Neuroscience)
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Graphical abstract
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<p>Flow chart of the animal experiment.</p>
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<p>Growth curves of different rat groups during the study. NC: Normal control, HF: High-fat, HFHS: High-fat/high-sucrose. Similar letters mean non-significant difference within groups at <span class="html-italic">p</span> &lt; 0.05.</p>
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<p>Acetyl cholinesterase in brain tissue of normal rat and obese rat groups. Similar letters mean non-significant difference within groups at <span class="html-italic">p</span> &lt; 0.05.</p>
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<p>Y-maze and Morris water maze tests of normal rat and obese rat groups. (<b>A</b>,<b>C</b>) Similar letters mean non-significant difference within groups at <span class="html-italic">p</span> &lt; 0.05. (<b>B</b>) * <span class="html-italic">p</span> &gt; 0.05 and *** <span class="html-italic">p</span> &gt; 0.001.</p>
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<p>Counts of Bacteroidetes and Firmicutes phyla in rat feces quantified by qPCR and expressed as log10 copies/g wet feces and Firmicutes/Bacteroidetes ratio. (<b>a</b>) Bacteroidetes and Firmicutes count; (<b>b</b>) Firmicutes/Bacteroidetes ratio. For each phylum, bars with different letters are significantly different at <span class="html-italic">p</span> ≤ 0.05.</p>
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<p>Relative abundance of microbiota at the phylum level in the guts of rats among the test groups using metagenomic analysis. NC: Normal control, HF: High-fat, HFHS: High-fat/high-sucrose.</p>
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<p>Relative abundance of microbiota at the family level in the guts of rats among the test groups using metagenomic analysis. NC: Normal control, HF: High-fat, HFHS: High-fat/high-sucrose.</p>
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<p>Relative abundance of microbiota at the genus level in the guts of rats among the test groups using metagenomic analysis. NC: Normal control, HF: High-fat, HFHS: High-fat/high-sucrose.</p>
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<p>Heat map of the top 25 species differentially enriched across the test groups. NC: Normal control, HF: High-fat, HFHS: High-fat/high-sucrose.</p>
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21 pages, 2438 KiB  
Review
Evaluating the Mechanisms and Efficiency of Johkasou Systems for Decentralized Domestic Effluent Treatment: A Review
by Xu Wang, Siyue Cheng and Huilun Chen
Water 2024, 16(16), 2266; https://doi.org/10.3390/w16162266 (registering DOI) - 12 Aug 2024
Viewed by 26
Abstract
Johkasou systems have emerged as quintessential examples of decentralized wastewater treatment technologies due to their compact design, easy operation, and robust resistance to mechanical impact attributes that are particularly effective in mitigating and treating rural domestic wastewater. Although the efficiency of the Johkasou [...] Read more.
Johkasou systems have emerged as quintessential examples of decentralized wastewater treatment technologies due to their compact design, easy operation, and robust resistance to mechanical impact attributes that are particularly effective in mitigating and treating rural domestic wastewater. Although the efficiency of the Johkasou process in removing nitrogen and phosphorus has been well-documented, a comprehensive synthesis of the underlying mechanisms and influencing factors is still elusive. This review seeks to elucidate these aspects by detailing the biogeochemical pathways involved in nitrogen and phosphorus removal, characterizing the key microbial consortia, and addressing the potential accumulation of nitrous oxide (N2O). Furthermore, the review critically examines the impact of various media used in Johkasou systems on nutrient removal efficacy, with a particular emphasis on nitrogen. It also proposes a range of practical adjustments to design parameters, including dissolved oxygen (DO), pH, temperature, and hydraulic retention time (HRT), to enhance process performance. Finally, the practical implementation of Johkasou systems and their integration with ancillary processes in actual domestic sewage treatment scenarios are synthesized, providing a theoretical foundation for advancing Johkasou methodologies in rural areas. Full article
(This article belongs to the Special Issue Wastewater Treatment and Reuse Advances Review)
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<p>Structure of small Johkasou.</p>
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<p>The main nitrogen removal pathways. (<b>a</b>) Complete nitrification and denitrification; (<b>b</b>) simultaneous nitrification and denitrification; (<b>c</b>) anaerobic ammonia oxidation. Note: AOB: ammonia-oxidizing bacteria; NOB: nitrite-oxidizing bacteria; DNB: denitrifying bacteria; AnAOB: anaerobic ammonia-oxidizing bacteria.</p>
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<p>Simplified introduction of the three N<sub>2</sub>O production pathways [<a href="#B62-water-16-02266" class="html-bibr">62</a>] (reprinted with permission).</p>
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<p>The main phosphorus removal pathways. (<b>a</b>) Anaerobic phosphorus release and aerobic phosphorus absorption [<a href="#B71-water-16-02266" class="html-bibr">71</a>]; (<b>b</b>) simultaneous nitrogen and phosphorus removal [<a href="#B72-water-16-02266" class="html-bibr">72</a>]; (<b>c</b>) electrocoagulation for phosphorus removal [<a href="#B73-water-16-02266" class="html-bibr">73</a>]. Note: PAOs: polyphosphate accumulating organisms; GAOs: glycogen accumulating organisms; AnAOB: anaerobic ammonia-oxidizing bacteria; CAOB: Comammox <span class="html-italic">Nitrospira</span> (reprinted with permission).</p>
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15 pages, 1073 KiB  
Review
Revisiting the Immunometabolic Basis for the Metabolic Syndrome from an Immunonutritional View
by César Jeri Apaza, Juan Francisco Cerezo, Aurora García-Tejedor, Juan Antonio Giménez-Bastida and José Moisés Laparra-Llopis
Biomedicines 2024, 12(8), 1825; https://doi.org/10.3390/biomedicines12081825 (registering DOI) - 12 Aug 2024
Viewed by 50
Abstract
Metabolic syndrome (MetS) implies different conditions where insulin resistance constitutes a major hallmark of the disease. The disease incurs a high risk for the development of cardiovascular complications, and takes its toll in regard to the gut–liver axis (pancreas, primary liver and colorectal)-associated [...] Read more.
Metabolic syndrome (MetS) implies different conditions where insulin resistance constitutes a major hallmark of the disease. The disease incurs a high risk for the development of cardiovascular complications, and takes its toll in regard to the gut–liver axis (pancreas, primary liver and colorectal)-associated immunity. The modulation of immunometabolic responses by immunonutritional factors (IFs) has emerged as a key determinant of the gut–liver axis’ metabolic and immune health. IFs from plant seeds have shown in vitro and pre-clinical effectiveness primarily in dealing with various immunometabolic and inflammatory diseases. Only recently have immunonutritional studies established the engagement of innate intestinal immunity to effectively control immune alterations in inflamed livers preceding the major features of the MetS. However, integrative analyses and the demonstration of causality between IFs and specific gut–liver axis-associated immunometabolic imbalances for the MetS remain ill-defined in the field. Herein, a better understanding of the IFs with a significant role in the MetS, as well as within the dynamic interplay in the functional differentiation of innate immune key effectors (i.e., monocytes/macrophages), worsening or improving the disease, could be of crucial relevance. The development of an adequate intermediary phenotype of these cells can significantly contribute to maintaining the function of Tregs and innate lymphoid cells for the prevention and treatment of MetS and associated comorbidities. Full article
(This article belongs to the Special Issue Immunometabolic Determinants of Gut–Liver Axis Health)
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Figure 1
<p>Schematic diagram for the interaction of the genetic and environmental factors influencing the control of hepatic fat accumulation by macrophages. ILCs, innate lymphoid cells; FA, fatty acids.</p>
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<p>Schematic hypothesis to explain the potential different contribution of TLR4 to the inflammatory phenotype of macrophages in the metabolic syndrome. SETIs, serine-type protease inhibitors; LPS, bacterial lipopolysaccharide; IRF3, interferon regulatory factor 3; IFNs, interferons; IS, insulin sensitivity. Small-dotted line represents the sequence of events triggered by the activation of TLR4 by the prototypical agonist LPS (red symbols and arrows). Solid line represents the sequence of events triggered by the activation of TLR4 by SETIs (green symbols and arrows). Large-dotted line represents the influence of insulin on the NRLP3 expression.</p>
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14 pages, 2693 KiB  
Article
Thermally Active Medium-Density Fiberboard (MDF) with the Addition of Phase Change Materials for Furniture and Interior Design
by Julia Dasiewicz, Anita Wronka, Aleksandra Jeżo and Grzegorz Kowaluk
Materials 2024, 17(16), 4001; https://doi.org/10.3390/ma17164001 (registering DOI) - 12 Aug 2024
Viewed by 72
Abstract
No matter where we reside, the issue of greenhouse gas emissions impacts us all. Their influence has a disastrous effect on the earth’s climate, producing global warming and many other irreversible environmental impacts, even though it is occasionally invisible to the independent eye. [...] Read more.
No matter where we reside, the issue of greenhouse gas emissions impacts us all. Their influence has a disastrous effect on the earth’s climate, producing global warming and many other irreversible environmental impacts, even though it is occasionally invisible to the independent eye. Phase change materials (PCMs) can store and release heat when it is abundant during the day (e.g., from solar radiation), for use at night, or on chilly days when buildings need to be heated. As a consequence, buildings use less energy to heat and cool, which lowers greenhouse gas emissions. Consequently, research on thermally active medium-density fiberboard (MDF) with PCMs is presented in this work. MDF is useful for interior design and furniture manufacturing. The boards were created using pine (Pinus sylvestris L.) and spruce (Picea abies L.) fibers, urea–formaldehyde resin, and PCM powder, with a phase transition temperature of 22 °C, a density of 785 kg m−3, a latent heat capacity of 160 kJ kg−1, a volumetric heat capacity of 126 MJ m−3, a specific heat capacity of 2.2 kJ kgK−1, a thermal conductivity of 0.18 W mK−1, and a maximum operating temperature of 200 °C. Before resination, the wood fibers were divided into two outer layers (16%) and an interior layer (68% by weight). Throughout the resination process, the PCM particles were solely integrated into the inner layer fibers. The mats were created by hand. A hydraulic press (AKE, Mariannelund, Sweden) was used to press the boards, and its operating parameters were 180 °C, 20 s/mm of nominal thickness, and 2.5 MPa for the maximum unit pressing pressure. Five variants of MDF with a PCM additive were developed: 0%, 5%, 10%, 30%, and 50%. According to the study, scores at the MOR, MOE, IB, and screw withdrawal resistance (SWR) tests decreased when PCM content was added, for example, MOE from 3176 to 1057 N mm−2, MOR from 41.2 to 11.5 N mm−2, and IB from 0.78 to 0.27 N mm−2. However, the results of the thickness swelling and water absorption tests indicate that the PCM particles do not exhibit a substantial capacity to absorb water, retaining the dimensional stability of the MDF boards. The thickness swelling positively decreased with the PCM content increase from 15.1 to 7.38% after 24 h of soaking. The panel’s thermal characteristics improved with the increasing PCM concentration, according to the data. The density profiles of all the variations under consideration had a somewhat U-shaped appearance; however, the version with a 50% PCM content had a flatter form and no obvious layer compaction on the panel surface. Therefore, certain mechanical and physical characteristics of the manufactured panels can be enhanced by a well-chosen PCM addition. Full article
(This article belongs to the Special Issue Thermal Stability and Fire Performance of Polymeric Materials)
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<p>Influence of various contents of PCM on the MOR of produced MDF.</p>
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<p>Influence of various contents of PCM on the MOE of produced MDF.</p>
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<p>Water absorption of the MDF produced with the use of various contents of PCM.</p>
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<p>Thickness swelling of the MDF produced with the use of various contents of PCM.</p>
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<p>Thermal properties of MDF produced with different contents of PCM.</p>
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<p>Screw withdrawal resistance of the MDF produced with the use of various contents of PCM.</p>
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<p>Internal bond of the MDF produced with the use of various contents of PCM.</p>
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<p>Density profiles of tested samples.</p>
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15 pages, 5822 KiB  
Article
Microstructure and Mechanical Properties of As-Cast Al-10Ce-3Mg-xZn Alloys
by Haiyang Zhang, Mingdong Wu, Zeyu Li, Daihong Xiao, Yang Huang, Lanping Huang and Wensheng Liu
Materials 2024, 17(16), 3999; https://doi.org/10.3390/ma17163999 (registering DOI) - 12 Aug 2024
Viewed by 100
Abstract
The microstructure and mechanical properties of as-cast Al-10Ce-3Mg-xZn (x = 0, 1, 3, 5 wt.%) alloys were systematically investigated, with a focus on the effect of Zn on the Al11Ce3 reinforcing phase in the alloy. The results showed that the [...] Read more.
The microstructure and mechanical properties of as-cast Al-10Ce-3Mg-xZn (x = 0, 1, 3, 5 wt.%) alloys were systematically investigated, with a focus on the effect of Zn on the Al11Ce3 reinforcing phase in the alloy. The results showed that the Al-10Ce-3Mg alloy consists of α-Al, a Chinese-script Al11Ce3 eutectic phase, and a massive Al11Ce3 primary phase. With the addition of Zn content, most of the Zn atoms are enriched in the Al11Ce3 phase to form the acicular-like Al2CeZn2 phase within the Al11Ce3 phase. Increasing the Zn content can increase the volume fraction of the Al11Ce3 phase. Compared to the alloy without Zn addition, the microhardness and elastic modulus of the Al2CeZn2-reinforced Al11Ce3 phase in the alloy with 5 wt.% Zn increased by 18.9% and 9.0%, respectively. Moreover, the room-temperature mechanical properties of Al-10Ce-3Mg alloys were significantly improved due to the addition of Zn element. The alloy containing 5 wt.% Zn had the best tensile properties with an ultimate tensile strength of 210 MPa and a yield strength of 171MPa, which were 21% and 77% higher than those of the alloy without Zn, respectively. The alloy containing 5 wt.% Zn demonstrated a superior retention ratio of tensile strength at 200–300 °C, indicating that the alloy has excellent heat resistance. The improvement in the mechanical properties is primarily attributed to second-phase strengthening and solid solution strengthening. Full article
(This article belongs to the Collection Alloy and Process Development of Light Metals)
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Graphical abstract
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<p>XRD patterns of the as-cast Al-10Ce-3Mg alloys with various Zn concentrations. The red dotted circle indicates that the intensity of the Al<sub>11</sub>Ce<sub>3</sub> peak increases with increasing Zn content.</p>
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<p>Backscattered SEM micrographs of the as-cast Al-10Ce-3Mg alloys with various Zn concentrations: (<b>a</b>) alloy 1, (<b>b</b>) alloy 2, (<b>c</b>) alloy 3, and (<b>d</b>) alloy 4.</p>
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<p>SEM micrographs of the 3D morphologies of intermetallic phases revealed by deep-etching in as-cast Al–10Ce-3Mg alloys with various Zn concentrations: (<b>a1</b>,<b>a2</b>) alloy 1, (<b>b1</b>,<b>b2</b>) alloy 2, (<b>c1</b>,<b>c2</b>) alloy 3, and (<b>d1</b>,<b>d2</b>) alloy 4.</p>
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<p>Electron probe microanalysis elemental maps of the as-cast Al-10Ce-3Mg alloys with various Zn concentrations: (<b>a</b>) alloy 1 and (<b>b</b>) alloy 4.</p>
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<p>TEM investigations of alloy 1: (<b>a</b>) HAADF-STEM micrograph of Al<sub>11</sub>Ce<sub>3</sub> phase; (<b>b</b>) HAADF-STEM image of the square area in (<b>a</b>); (<b>c</b>) HRTEM image and corresponding SAED patterns of the square area in (<b>b</b>); TEM investigations of alloy 4: (<b>d</b>) bright-field image of Al<sub>11</sub>Ce<sub>3</sub> phase; (<b>e</b>) HAADF-STEM image of the square area in (<b>d</b>); (<b>f</b>) HRTEM image and SAED patterns of the square area in (<b>e</b>); (<b>g</b>) corresponding EDS element maps of (<b>e</b>).</p>
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<p>A 3D-APT analysis of the as-cast Al-10Ce-3Mg-5Zn: (<b>a</b>) 3-D reconstruction with individual atoms shown, and 20 at% Zn isoconcentration surfaces are delineated in blue; (<b>b</b>) 3-D atom maps showing the distribution of each individual atomic species; (<b>c</b>) a proximity histogram showing the elemental distributions across a Zn-rich precipitate interface, as indicated by the red arrow in (<b>a</b>).</p>
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<p>Nanoindentation curves (<b>a</b>) and microhardness indents in the primary phase (<b>b</b>,<b>c</b>) of the as-cast Al-10Ce-3Mg alloys with various Zn concentrations.</p>
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<p>The hardness values of the as-cast Al-10Ce-3Mg alloys with various Zn concentrations.</p>
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<p>The engineering stress–strain curves of the as-cast Al-10Ce-3Mg alloys with various Zn concentrations at different temperatures: (<b>a</b>) 25 °C; (<b>b</b>) 200 °C; (<b>c</b>) 260 °C; (<b>d</b>) 300 °C.</p>
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<p>Fracture morphology and the longitudinal sectional area near the fracture surface of the as-cast Al-10Ce-3Mg alloys with various Zn concentrations: (<b>a1</b>,<b>a2</b>) alloy 1, (<b>b1</b>,<b>b2</b>) alloy 2, (<b>c1</b>,<b>c2</b>) alloy 3, and (<b>d1</b>,<b>d2</b>) alloy 4.</p>
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12 pages, 2991 KiB  
Article
Ohmic Contact Formation to β-Ga2O3 Nanosheet Transistors with Ar-Containing Plasma Treatment
by Jin-Xin Chen, Bing-Yan Liu, Yang Gu and Bin Li
Electronics 2024, 13(16), 3181; https://doi.org/10.3390/electronics13163181 (registering DOI) - 12 Aug 2024
Viewed by 159
Abstract
Effective Ohmic contact between metals and their conductive channels is a crucial step in developing high-performance Ga2O3-based transistors. Distinct from bulk materials, excess thermal energy of the annealing process can destroy the low-dimensional material itself. Given the thermal budget [...] Read more.
Effective Ohmic contact between metals and their conductive channels is a crucial step in developing high-performance Ga2O3-based transistors. Distinct from bulk materials, excess thermal energy of the annealing process can destroy the low-dimensional material itself. Given the thermal budget concern, a feasible and moderate solution (i.e., Ar-containing plasma treatment) is proposed to achieve effective Ohmic junctions with (100) β-Ga2O3 nanosheets. The impact of four kinds of plasma treatments (i.e., gas mixtures SF6/Ar, SF6/O2/Ar, SF6/O2, and Ar) on (100) β-Ga2O3 crystals is comparatively studied by X-ray photoemission spectroscopy for the first time. With the optimal plasma pre-treatment (i.e., Ar plasma, 100 W, 60 s), the resulting β-Ga2O3 nanosheet field-effect transistors (FETs) show effective Ohmic contact (i.e., contact resistance RC of 104 Ω·mm) without any post-annealing, which leads to competitive device performance such as a high current on/off ratio (>107), a low subthreshold swing (SS, 249 mV/dec), and acceptable field-effect mobility (μeff, ~21.73 cm2 V−1 s−1). By using heavily doped β-Ga2O3 crystals (Ne, ~1020 cm−3) for Ar plasma treatments, the contact resistance RC can be further decreased to 5.2 Ω·mm. This work opens up new opportunities to enhance the Ohmic contact performance of low-dimensional Ga2O3-based transistors and can further benefit other oxide-based nanodevices. Full article
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Figure 1
<p>XPS results for the (100)-oriented <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> bulk samples. (<b>a</b>) Ga 2<span class="html-italic">p</span><sub>3/2</sub>, (<b>b</b>) Ga 3<span class="html-italic">d</span>, and (<b>c</b>) O 1<span class="html-italic">s</span> core-level spectra from the pristine <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> without any plasma treatments. (<b>d</b>) Ga 2<span class="html-italic">p</span><sub>3/2</sub>, (<b>e</b>) Ga 3<span class="html-italic">d</span>, and (<b>f</b>) O 1<span class="html-italic">s</span> core-level spectra from the <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> treated with SF<sub>6</sub>/Ar plasmas.</p>
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<p>XPS results for (100) <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> bulk samples. (<b>a</b>) O 1<span class="html-italic">s</span>, (<b>b</b>) Ga 2<span class="html-italic">p</span><sub>3/2</sub>, and (<b>c</b>) Ga 3<span class="html-italic">d</span> core-level spectra from the <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> treated with SF<sub>6</sub>/O<sub>2</sub>/Ar plasmas. (<b>d</b>) O 1<span class="html-italic">s</span> and (<b>e</b>) F 1<span class="html-italic">s</span> core-level spectra from the <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> treated with SF<sub>6</sub>/O<sub>2</sub> plasmas. (<b>f</b>) Two-terminal <span class="html-italic">I</span>–<span class="html-italic">V</span> curves of the <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> nanosheet pre-treated with (red) and without (black) SF<sub>6</sub>/O<sub>2</sub> plasmas.</p>
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<p>XPS spectra of O 1<span class="html-italic">s</span> for the (100) <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> bulk samples treated by Ar plasmas with different power and time: (<b>a</b>) 100 W, 30 s; (<b>b</b>) 100 W, 60 s; (<b>c</b>) 100 W, 90 s; (<b>d</b>) 200 W, 30 s; (<b>e</b>) 200 W, 60 s; and (<b>f</b>) 200 W, 90 s.</p>
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<p>The <span class="html-italic">V</span><sub>O</sub>/(<span class="html-italic">L</span><sub>O</sub> + <span class="html-italic">V</span><sub>O</sub>) area ratio for the Ar-treated <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> (100) bulk samples as a function of treatment time and power.</p>
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<p>(<b>a</b>) Schematic view of the bottom-gated <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> nanosheet transistor with a 110 nm thick SiO<sub>2</sub> gate insulator. (<b>b</b>) Optical microscopy image of a prepared <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> nanosheet-based FET. (<b>c</b>) Thickness profile and optical micrograph from the peeled <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> nanosheet as acquired by AFM. (<b>d</b>) <span class="html-italic">I</span>–<span class="html-italic">V</span> characteristics at a low <span class="html-italic">V</span><sub>ds</sub> regime for this <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> nanosheet FET. (<b>e</b>) Output curves (<span class="html-italic">I</span><sub>ds</sub>-<span class="html-italic">V</span><sub>ds</sub>) from the <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> nanosheet FET. (<b>f</b>) Transfer characteristics (<span class="html-italic">I</span><sub>ds</sub>-<span class="html-italic">V</span><sub>bg</sub>) obtained from the <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> nanosheet transistor.</p>
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<p>Contact resistance in the heavily doped <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> nanosheet samples (<span class="html-italic">N</span><sub>e</sub>, ~10<sup>20</sup> cm<sup>−3</sup>). (<b>a</b>) <span class="html-italic">I</span>–<span class="html-italic">V</span> curves of the heavily doped <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> devices with different <span class="html-italic">L</span><sub>ch</sub>/<span class="html-italic">S</span> ratios determined by TLM. (<b>b</b>) Total resistance (<span class="html-italic">R</span><sub>t</sub>) plotted as a function of the <span class="html-italic">L</span><sub>ch</sub>/<span class="html-italic">S</span> ratio in <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> devices.</p>
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<p>(<b>a</b>) Micro-Raman spectra for the peeled <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> nanosheet on the SiO<sub>2</sub>/Si (p<sup>2+</sup>) substrate before and after Ar plasma pre-treatment (100 W, 60 s). (<b>b</b>) Micro-XRD pattern for the peeled <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> nanosheet on the SiO<sub>2</sub>/Si (p<sup>2+</sup>) substrate after Ar plasma pre-treatment. The inset gives the micro-XRD pattern of the <span class="html-italic">β</span>-Ga<sub>2</sub>O<sub>3</sub> nanosheet before Ar plasma pre-treatment.</p>
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12 pages, 2688 KiB  
Article
Application of High Hydrostatic Pressures and Refrigerated Storage on the Content of Resistant Starch in Selected Legume Seeds
by Adrianna Bojarczuk, Joanna Le-Thanh-Blicharz, Dorota Michałowska, Danuta Kotyrba and Krystian Marszałek
Appl. Sci. 2024, 14(16), 7049; https://doi.org/10.3390/app14167049 (registering DOI) - 11 Aug 2024
Viewed by 369
Abstract
Resistant starch (RS) is a fraction of starch not digested and absorbed in the small intestine, and it is fermented by the intestinal microbiota in the colon, thereby influencing many health benefits. Legumes such as beans, lentils, and chickpeas are rich in fermentable [...] Read more.
Resistant starch (RS) is a fraction of starch not digested and absorbed in the small intestine, and it is fermented by the intestinal microbiota in the colon, thereby influencing many health benefits. Legumes such as beans, lentils, and chickpeas are rich in fermentable dietary fiber, and RS can be included in this fiber group. These legumes are not considered a “typical” source of starch and have not been extensively studied as a source of RS. There are still insufficient data on modern non-thermal methods like high-pressure processing (HPP) and combining this method with refrigerated storage. The study aimed to investigate and compare the effects of HPP and HPP combined with refrigerated storage on the RS content of legumes, particularly white beans, green lentils, and chickpeas. Different pressure levels and processing times were used to evaluate changes in RS content and to assess the total fiber content and fiber fraction of the tested legumes. Our study showed that the increase in pressure and pressurization time affected changes in the RS content of the examined legumes. Furthermore, the cooling process of previously pressurized samples resulted in a significant increase in RS content. Full article
(This article belongs to the Section Food Science and Technology)
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<p>Total dietary fiber content in selected starchy products [%d.m].</p>
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<p>Content of total fiber and its fractions in the tested legumes.</p>
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<p>Effect of pressure time and pressure values on cooled and uncooled bean samples. (<b>a</b>,<b>b</b>) Uncooled samples; (<b>c</b>,<b>d</b>) cooled samples; control sample—unprocessed starch.</p>
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<p>Effect of pressure time and pressure values on cooled and uncooled chickpeas samples. (<b>a</b>,<b>b</b>) Uncooled samples; (<b>c</b>,<b>d</b>) cooled samples; control sample—unprocessed starch.</p>
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<p>Effect of pressure time and pressure values on cooled and uncooled lentil samples. (<b>a</b>,<b>b</b>) Uncooled samples; (<b>c</b>,<b>d</b>) cooled samples; control sample—unprocessed starch.</p>
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<p>The phase contrast microscopy image (600× magnification) of chickpeas starch structure after high-pressure treatments (600 MPa). (<b>a</b>) Control sample—unprocessed starch; (<b>b</b>) 3 min; (<b>c</b>) 6 min; (<b>d</b>) 9 min.</p>
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<p>Cooling effect on RS content from averages of all tested pressures and times on bean (<b>a</b>), chickpea (<b>b</b>), and lentil (<b>c</b>) samples.</p>
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19 pages, 4944 KiB  
Article
2D-URANS Study on the Impact of Relative Diameter on the Flow and Drag Characteristics of Circular Cylinder Arrays
by Mengyang Liu, Yisen Wang, Yiqing Gong and Shuxia Wang
Water 2024, 16(16), 2264; https://doi.org/10.3390/w16162264 (registering DOI) - 11 Aug 2024
Viewed by 355
Abstract
The flow structure around limited-size vegetation patches is crucial for understanding sediment transport and vegetation succession trends. While the influence of vegetation density has been extensively explored, the impact of the relative diameter of vegetation stems remains relatively unclear. After validating the reliability [...] Read more.
The flow structure around limited-size vegetation patches is crucial for understanding sediment transport and vegetation succession trends. While the influence of vegetation density has been extensively explored, the impact of the relative diameter of vegetation stems remains relatively unclear. After validating the reliability of the numerical model with experimental data, this study conducted 2D-URANS simulations (SST k-ω) to investigate the impact of varying relative diameters d/D under different vegetation densities λ on the hydrodynamic characteristics and drag force of vegetation patches. The results show that increasing d/D and decreasing λ are equivalent, both contributing to increased spacing between cylinder elements, allowing for the formation of element-scale Kármán vortices. Compared to vegetation density λ, the non-dimensional frontal area aD is a better predictor for the presence of array-scale Kármán vortex streets. Within the parameter range covered in this study, array-scale Kármán vortex streets appear when aD ≥ 1.4, which will significantly alter sediment transport patterns. For the same vegetation density, increasing the relative diameter d/D leads to a decrease in the array drag coefficient C¯D and an increase in the average element drag coefficient C¯d. When parameterizing vegetation resistance using aD, all data points collapse onto a single curve, following the relationships C¯D=0.34lnaD+0.78 and C¯d=0.42lnaD+0.82. Full article
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Figure 1
<p>Schematic of the computational domain (not to scale).</p>
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<p>Computational grid of the numerical domain: (<b>a</b>) local view; (<b>b</b>) global view.</p>
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<p>Comparison of numerical results with experimental measurements for <span class="html-italic">λ</span> = 0.03 (<span class="html-italic">aD</span> = 1.32): (<b>a</b>) longitudinal time-averaged velocity along the <span class="html-italic">y</span> = 0 line; (<b>b</b>) transverse time-averaged velocity along the <span class="html-italic">y</span> = 0.5<span class="html-italic">D</span> line. The shaded area indicates the location of the vegetation patch.</p>
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<p>Contour plots of non-dimensional time-averaged longitudinal flow velocity: (<b>a</b>) <span class="html-italic">λ</span> = 0.05 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05; (<b>b</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.039; (<b>c</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05; (<b>d</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.07; (<b>e</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.118; (<b>f</b>) <span class="html-italic">λ</span> = 0.16 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05.</p>
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<p>Contour plots of non-dimensional time-averaged transverse flow velocity: (<b>a</b>) <span class="html-italic">λ</span> = 0.05 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05; (<b>b</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.039; (<b>c</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05; (<b>d</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.07; (<b>e</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.118; (<b>f</b>) <span class="html-italic">λ</span> = 0.16 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05.</p>
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<p>Contour plots of near-field non-dimensional turbulent kinetic energy (left) and non-dimensional instantaneous vertical vorticity (right): (<b>a</b>) <span class="html-italic">λ</span> = 0.05 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05; (<b>b</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.039; (<b>c</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05; (<b>d</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.07; (<b>e</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.118; (<b>f</b>) <span class="html-italic">λ</span> = 0.16 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05.</p>
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<p>Contour plots of far-field non-dimensional turbulent kinetic energy: (<b>a</b>) <span class="html-italic">λ</span> = 0.05 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05; (<b>b</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.039; (<b>c</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05; (<b>d</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.07; (<b>e</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.118; (<b>f</b>) <span class="html-italic">λ</span> = 0.16 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05.</p>
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<p>Contour plots of far-field instantaneous non-dimensional vertical vorticity: (<b>a</b>) <span class="html-italic">λ</span> = 0.05 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.036; (<b>b</b>) <span class="html-italic">λ</span> = 0.05 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05; (<b>c</b>) <span class="html-italic">λ</span> = 0.05 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.085; (<b>d</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.039; (<b>e</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05; (<b>f</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.07; (<b>g</b>) <span class="html-italic">λ</span> = 0.097 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.118; (<b>h</b>) <span class="html-italic">λ</span> = 0.16 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.041; (<b>i</b>) <span class="html-italic">λ</span> = 0.16 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.05; (<b>j</b>) <span class="html-italic">λ</span> = 0.16 <span class="html-italic">d</span>/<span class="html-italic">D</span> = 0.064.</p>
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<p>Dependence of flow rate through the vegetation patch on (<b>a</b>) vegetation density <span class="html-italic">λ</span> and (<b>b</b>) non-dimensional frontal area <span class="html-italic">aD</span>.</p>
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<p>Dependence of (<b>a</b>) array drag coefficient and (<b>b</b>) average cylinder element drag coefficient on vegetation density.</p>
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<p>Dependence of (<b>a</b>) array drag coefficient and (<b>b</b>) average cylinder element drag coefficient on non-dimensional frontal area <span class="html-italic">aD</span>.</p>
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<p>Longitudinal distribution along the array centerline of (<b>a</b>) time-averaged longitudinal velocity and (<b>b</b>) turbulent kinetic energy. The shaded area indicates the location of the vegetation patch.</p>
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<p>Dependence of (<b>a</b>) bleeding flow velocity, (<b>b</b>) velocity in the steady wake region, and (<b>c</b>) length of the steady wake region on non-dimensional frontal area <span class="html-italic">aD</span>.</p>
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16 pages, 1908 KiB  
Article
Synthesis of Second-Generation Analogs of Temporin-SHa Peptide Having Broad-Spectrum Antibacterial and Anticancer Effects
by Arif Iftikhar Khan, Shahzad Nazir, Muhammad Nadeem ul Haque, Rukesh Maharjan, Farooq-Ahmad Khan, Hamza Olleik, Elise Courvoisier-Dezord, Marc Maresca and Farzana Shaheen
Antibiotics 2024, 13(8), 758; https://doi.org/10.3390/antibiotics13080758 (registering DOI) - 11 Aug 2024
Viewed by 317
Abstract
Antimicrobial peptides (AMPs) are a promising class of therapeutic alternatives with broad-spectrum activity against resistant pathogens. Small AMPs like temporin-SHa (1) and its first-generation analog [G10a]-SHa (2) possess notable efficacy against Gram-positive and Gram-negative bacteria. In an effort to [...] Read more.
Antimicrobial peptides (AMPs) are a promising class of therapeutic alternatives with broad-spectrum activity against resistant pathogens. Small AMPs like temporin-SHa (1) and its first-generation analog [G10a]-SHa (2) possess notable efficacy against Gram-positive and Gram-negative bacteria. In an effort to further improve this antimicrobial activity, second-generation analogs of 1 were synthesised by replacing the natural glycine residue at position-10 of the parent molecule with atypical amino acids, such as D-Phenylalanine, D-Tyrosine and (2-Naphthyl)-D-alanine, to study the effect of hydrophobicity on antimicrobial efficacy. The resultant analogs (36) emerged as broad-spectrum antibacterial agents. Notably, the [G10K]-SHa analog (4), having a lysine substitution, demonstrated a 4-fold increase in activity against Gram-negative (Enterobacter cloacae DSM 30054) and Gram-positive (Enterococcus faecalis DSM 2570) bacteria relative to the parent peptide (1). Among all analogs, [G10f]-SHa peptide (3), featuring a D-Phe substitution, showed the most potent anticancer activity against lung cancer (A549), skin cancer (MNT-1), prostate cancer (PC-3), pancreatic cancer (MiaPaCa-2) and breast cancer (MCF-7) cells, achieving an IC50 value in the range of 3.6–6.8 µM; however, it was also found to be cytotoxic against normal cell lines as compared to [G10K]-SHa (4). Peptide 4 also possessed good anticancer activity but was found to be less cytotoxic against normal cell lines as compared to 1 and 3. These findings underscore the potential of second-generation temporin-SHa analogs, especially analog 4, as promising leads to develop new broad-spectrum antibacterial and anticancer agents. Full article
(This article belongs to the Section Antimicrobial Peptides)
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<p>UPLC profiles of the synthesised peptides; (<b>A</b>) temporin-SHa; (<b>B</b>) [G10a]-SHa; (<b>C</b>) [G10f]-SHa; (<b>D</b>) [G10y]-SHa; (<b>E</b>) [G10n]-SHa and (<b>F</b>) [G10K]-SHa.</p>
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<p>Circular dichroism of temporin SHa, [G10a]-Sha, and newly synthesised second-generation analogs of [G10a]-SHa in 20 mM SDS.</p>
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<p>Antiproliferative effect of SHa derivatives on human cancer cells. The antiproliferative effect of SHa derivatives was measured on dividing cancer cells, as explained in <a href="#sec4-antibiotics-13-00758" class="html-sec">Section 4</a> (Temporin-SHa (<b>1</b>): open black circles, [G10a]-SHa (<b>2</b>): closed red circles, [G10f]-SHa (<b>2</b>): closed green squares, [G10K]-SHa (<b>3</b>): closed black diamonds, [G10n]-SHa (<b>4</b>): inverted open purple triangles, [G10y]-SHa (<b>5</b>): closed blue triangles). Results are expressed as a percentage of cell proliferation, the untreated cells giving 100% proliferation (means ± SD, <span class="html-italic">n</span> = 3).</p>
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<p>Antiproliferative effect of SHa derivatives on human normal/non cancerous cells. The antiproliferative effect of SHa derivatives was measured on dividing normal cells, as explained in <a href="#sec4-antibiotics-13-00758" class="html-sec">Section 4</a> (temporin-SHa (<b>1</b>): open black circles, [G10a]-SHa (<b>2</b>): closed red circles, [G10f]-SHa (<b>2</b>): closed green squares, [G10K]-SHa (<b>3</b>): closed black diamonds, [G10n]-SHa (<b>4</b>): inverted open purple triangles, [G10y]-SHa (<b>5</b>): closed blue triangles). Results are expressed as a percentage of cell proliferation, the untreated cells giving 100% proliferation (means ± SD, <span class="html-italic">n</span> = 3).</p>
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<p>Cytotoxic effect of SHa derivatives on human normal and cancer lung cells. The cytotoxic effect of temporin-SHa (<b>1</b>) derivatives was measured on confluent/non-dividing cells, as explained in <a href="#sec4-antibiotics-13-00758" class="html-sec">Section 4</a>, using human lung cancer (A549 cells) and normal cells (BEAS-2B cells); ([G10a]-SHa (<b>2</b>): closed red circles, [G10f]-SHa (<b>2</b>): closed green squares, [G10K]-SHa (<b>3</b>): closed black diamonds, [G10n]-SHa (<b>4</b>): inverted open purple triangles, [G10y]-SHa (<b>5</b>): closed blue triangles). Results are expressed as a percentage of cell proliferation, the untreated cells giving 100% proliferation (means ± SD, <span class="html-italic">n</span> = 3).</p>
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<p>Synthesis and structure of temporin-SHa (<b>1</b>), its first-generation [G10a]-SHa peptide (<b>2</b>) and newly synthesised second-generation analogs (<b>3</b>–<b>6</b>).</p>
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21 pages, 5648 KiB  
Article
Photosynthesis and Latex Burst Characteristics in Different Varieties of Rubber Trees (Hevea brasiliensis) under Chilling Stress, Combing Bark Tensile Property and Chemical Component Analysis
by Linlin Cheng, Huichuan Jiang, Guishui Xie, Jikun Wang, Wentao Peng, Lijun Zhou and Feng An
Forests 2024, 15(8), 1408; https://doi.org/10.3390/f15081408 (registering DOI) - 11 Aug 2024
Viewed by 306
Abstract
Rubber trees (Hevea brasiliensis) serve as the primary source of natural rubber. Their native habitat is characterized by warm and humid conditions, so they are particularly sensitive to low temperatures. Under such stress, latex burst can cause severe damage to rubber [...] Read more.
Rubber trees (Hevea brasiliensis) serve as the primary source of natural rubber. Their native habitat is characterized by warm and humid conditions, so they are particularly sensitive to low temperatures. Under such stress, latex burst can cause severe damage to rubber trees, which is due to the uniqueness of their economically productive parts. In order to establish a correlation between young and mature rubber trees and provide a novel prospective for investigating the mechanisms of latex burst and chilling resistance in rubber trees, the chlorophyll contents, photosynthesis, and chlorophyll fluorescence parameters in four varieties of one-year-old rubber tree seedlings were analyzed under artificially simulated chilling stress. The latex burst characteristics were subsequently recorded. A comprehensive statistical analysis of the chilling-resistance rank was conducted using the membership function method and the combination weighting method. Meanwhile, chemical compositions and tensile properties of barks from two-year-old twigs of mature rubber trees were ascertained. A correlation analysis between chilling resistance, chemical compositions, and tensile properties was performed to identify any interrelationships among them. The results showed that the number and the total area of latex-burst positions in variety Reken628 seedlings were greater than those in other varieties, and the lowest number and total area of latex-burst positions were observed in variety RRIM600 and variety PR107, respectively. With the exception of variety GT1, nectar secretion was noted in all other varieties of rubber tree seedlings under chilling stress. The chilling resistance of the four varieties decreased in the following order: variety GT1 > variety RRIM600 > variety PR107 > variety Reken628. The chilling resistance was strongly (p < 0.001) negatively correlated with cellulose content and acid-insoluble lignin content, respectively. The total area of latex burst was significantly (p < 0.001) and positively correlated with holocellulose content and maximum load, respectively. Furthermore, this study also provides new insights into the mechanism of nectar secretion induced by low temperatures and its association with the chilling resistance of rubber trees. Full article
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Figure 1
<p>Changes in photosynthetic pigment contents in rubber tree leaves under chilling stress. (<b>A</b>) Chlorophyll <span class="html-italic">a</span> content. (<b>B</b>) Chlorophyll <span class="html-italic">b</span> content. (<b>C</b>) Total chlorophyll content. (<b>D</b>) Carotenoid content. The data represent the average of three replicates. Bars show standard errors. Different lowercase letters represent significant differences (Duncan’s test of one-way ANOVA, <span class="html-italic">p</span> &lt; 0.05) among different varieties of rubber trees.</p>
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<p>Effect of chilling stress on the chlorophyll fluorescence parameters of rubber tree leaves. (<b>A</b>) The maximum photochemical efficiency of PSII, F<sub>v</sub>/F<sub>m</sub>. (<b>B</b>) The actual photochemical yield of PSII, Φ<sub>PSII</sub>. Data are means ± SEs (n = 3). Different lowercase letters represent significant differences (Duncan’s test of one-way ANOVA, <span class="html-italic">p</span> &lt; 0.05) among different rubber tree varieties.</p>
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<p>Effect of chilling stress on gas exchange parameters. (<b>A</b>) Photosynthetic rate is denoted as P<sub>n</sub>. (<b>B</b>) Stomatal conductance is denoted as G<sub>s</sub>. (<b>C</b>) Intercellular CO<sub>2</sub> concentration is denoted as C<sub>i</sub>. (<b>D</b>) Transpiration rate is denoted as T<sub>r</sub>. Different lowercase letters represent significant differences (Duncan’s test of one-way ANOVA, <span class="html-italic">p</span> &lt; 0.05) among different rubber tree varieties.</p>
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<p>Visual latex burst in different rubber tree seedlings. (<b>A-1</b>–<b>A-3</b>) Variety PR107 seedlings. (<b>B-1</b>–<b>B-4</b>) Variety RRIM600 seedlings. (<b>C-1</b>–<b>C-4</b>) Variety Reken628 seedlings. (<b>D-1</b>–<b>D-3</b>) Variety GT1 seedlings.</p>
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<p>Stress–strain curves for barks of two-year-old twigs in different varieties. Different colors represent different stress–strain curves of different specimens, respectively. (<b>A</b>) Variety PR107. (<b>B</b>) Variety RRIM600. (<b>C</b>) Variety Reken628. (<b>D</b>) Variety GT1.</p>
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<p>Correlation analysis between latex burst in seedlings exposed to chilling stress, bark tensile properties, and chemical components with the chilling resistance of different varieties of rubber trees. CR, chilling resistance; TALB, total area of latex burst; TLBP, total latex burst positions; BT, bark thickness; ML, maximum load; TS, tensile strength; DBP, displacement at break point; EBP, elongation at break point; YM, Young’s modulus; PC, pectin content; CC, cellulose content; AILC, acid-insoluble lignin content; HOC, holocellulose content. The larger the circle and the darker the color, the larger the correlation coefficient. Positive correlations are exhibited in red and negative correlations in blue. Significant differences are marked by asterisks, with the levels of significance indicated as follows: *** <span class="html-italic">p</span> &lt; 0.001.</p>
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18 pages, 7451 KiB  
Article
Study on the Lubrication Performance of Graphene-Based Polyphosphate Lubricants in High-Temperature Steel–Steel Friction Pair
by Kaifu Mi, Qingqing Ding, Xiangru Xu, Yu Lei, Juncheng Wang and Ning Kong
Surfaces 2024, 7(3), 571-588; https://doi.org/10.3390/surfaces7030039 (registering DOI) - 11 Aug 2024
Viewed by 286
Abstract
In the study, a hybrid lubricant was prepared by introducing graphene into a polyphosphate lubricant. In the tribological test of a steel/steel friction pair at the high temperature of 800 °C, the addition of a small proportion of graphene significantly enhances the lubrication [...] Read more.
In the study, a hybrid lubricant was prepared by introducing graphene into a polyphosphate lubricant. In the tribological test of a steel/steel friction pair at the high temperature of 800 °C, the addition of a small proportion of graphene significantly enhances the lubrication performance of polyphosphate at elevated temperatures. The coefficient of friction and the wear were obviously held down while the surface quality of the high-temperature friction pair was enhanced effectively with the graphene-strengthened polyphosphate lubricant, compared with the dry sliding condition. Through scanning electron microscopy and Raman spectroscopy analysis, the formation mechanism of tribofilm and the antiwear performance of the hybrid lubricant are further explained. This lubricant effectively combines the advantages of both; the combination of polyphosphate melted at elevated temperature with graphene and metal surfaces ensures the self-sealing of the friction contact area and brings better high-temperature oxidation resistance. At the same time, the presence of graphene provides excellent strength to the friction film and ensures the anti-wear and wear-resistant performance of the lubricant at high temperatures. Full article
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Graphical abstract

Graphical abstract
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<p>Three formulated lubricants and their main components.</p>
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<p>The temperature regime and the conditions of the tribotests.</p>
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<p>The TG curves and SEM images of (<b>a</b>) G showing its thermal stability in air and N2 and micro-morphology of initial film; (<b>b</b>) PO showing its thermal stability in air and N2 and micro-morphology of initial film; (<b>c</b>) G-PO showing its thermal stability in air and N2 and micro-morphology of initial film.</p>
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<p>Friction coefficient vs. time curves of dry friction and tribotests under different lubrication conditions.</p>
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<p>Laser scanning confocal microscopy, 3D topography, and height profile of the grinding mark for (<b>a</b>) dry friction; (<b>b</b>) tribotest under G lubricant; (<b>c</b>) tribotest under PO lubricant; (<b>d</b>) tribotest under G-PO lubricant.</p>
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<p>Wear loss of steel/steel pair under unlubricated and different lubricated conditions at 800 °C.</p>
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<p>SEM images of wear scars and tracks on the ball and flats after tribotests without lubricants (<b>a</b>,<b>b</b>), with G (<b>c</b>,<b>d</b>), with PO (<b>e</b>,<b>f</b>), and with G-PO (<b>g</b>,<b>h</b>); the Raman spectra of points within the grinding tracks on the flats after tribotests with G (<b>d’</b>) and G-PO (<b>h’</b>).</p>
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<p>Iron oxides in the grinding marks on the plates formed during tests at 800 °C without lubricants (<b>a</b>); with G (<b>b</b>); with PO (<b>c</b>); and with G-PO (<b>d</b>).</p>
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<p>The gradually enlarged SEM images of the interior of the grinding mark after tribotest with G-PO: (<b>a</b>) SEM image of the grinding mark; (<b>b</b>) the detail image of (<b>a</b>); (<b>c</b>) the detail image of the red position in (<b>b</b>); (<b>e</b>) the detail image of the blue position in (<b>b</b>); (<b>d</b>) The further amplification image of (<b>c</b>) and (<b>f</b>) the further amplification image of (<b>e</b>).</p>
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<p>The gradually enlarged SEM images of the edge of the grinding mark after tribotest with G-PO: (<b>a</b>–<b>c</b>).</p>
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<p>EDS mappings and the corresponding EDS spectra of the particle in <a href="#surfaces-07-00039-f009" class="html-fig">Figure 9</a>f (<b>a</b>,<b>b</b>) and <a href="#surfaces-07-00039-f010" class="html-fig">Figure 10</a>c (<b>c</b>,<b>d</b>).</p>
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<p>Lubrication mechanism of G-PO lubricant at various temperatures.</p>
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26 pages, 4780 KiB  
Article
Synthesis, Structural Properties and Biological Activities of Novel Hydrazones of 2-, 3-, 4-Iodobenzoic Acid
by Izabela Czyżewska, Liliana Mazur, Anna Biernasiuk, Anna Hordyjewska and Łukasz Popiołek
Molecules 2024, 29(16), 3814; https://doi.org/10.3390/molecules29163814 (registering DOI) - 11 Aug 2024
Viewed by 389
Abstract
Nowadays, searching for novel antimicrobial agents is crucial due to the increasing number of resistant bacterial strains. Moreover, cancer therapy is a major challenge for modern medicine. Currently used cytostatics have a large number of side effects and insufficient therapeutic effects. Due to [...] Read more.
Nowadays, searching for novel antimicrobial agents is crucial due to the increasing number of resistant bacterial strains. Moreover, cancer therapy is a major challenge for modern medicine. Currently used cytostatics have a large number of side effects and insufficient therapeutic effects. Due to the above-mentioned facts, we undertook research to synthesize novel compounds from the acylhydrazone group aimed at obtaining potential antimicrobial and anticancer agents. As a starting material, we employed hydrazides of 2-, 3- or 4-iodobenzoic acid, which gave three series of acylhydrazones in the condensation reaction with various aldehydes. The chemical structure of all obtained compounds was confirmed by IR, 1H NMR, and 13C NMR. The structure of selected compounds was determined by single-crystal X-ray diffraction analysis. Additionally, all samples were characterized using powder X-ray diffraction. The other issue in this research was to examine the possibility of the solvent-free synthesis of compounds using mechanochemical methods. The biological screening results revealed that some of the newly synthesized compounds indicated a beneficial antimicrobial effect even against MRSA—the methicillin-resistant Staphylococcus aureus ATCC 43300 strain. In many cases, the antibacterial activity of synthesized acylhydrazones was equal to or better than that of commercially available antibacterial agents that were used as reference substances in this research. Significantly, the tested compounds do not show toxicity to normal cell lines either. Full article
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Figure 1

Figure 1
<p>PXRD patterns of compound <b>13</b>: (<b>a</b>) simulated from the SCXRD data; (<b>b</b>) experimental after synthesis from solution; (<b>c</b>–<b>e</b>) experimental after liquid-assisted grinding (LAG) for 30, 60 and 90 min, respectively, using ethanol as a solvent; (<b>f</b>) experimental after LAG for 90 min using acetonitrile.</p>
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<p>Perspective view of the molecules constituting the asymmetric part in crystals <b>13</b>, <b>13</b>∙<b>ACN</b>, <b>20</b> and <b>26a</b> with the atom-numbering scheme. Thermal ellipsoids are drawn at the 50% probability level. Dashed lines indicate the hydrogen bonds.</p>
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<p>Molecular overlay of the conformers found in: (<b>a</b>) polymorphic modifications <b>26a</b> (red line), <b>26b</b> (green line) and <b>26c</b> (dark blue line); (<b>b</b>) unsolvated crystal <b>13</b> (molecule 13A—blue line, molecule 13B—green line) and its solvate <b>13</b>∙<b>ACN</b> (pink line).</p>
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<p>Part of the crystal structure of <b>13</b>·<b>ACN</b> in view along the <span class="html-italic">a</span> axis, showing the formation of channels filled in by the solvent molecules.</p>
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<p>Part of the crystal structure of <b>9</b> showing (<b>a</b>) supramolecular chains stabilized via strong N1–H1n∙∙∙O1A/N1A–H1nA∙∙∙O1 (x, y + 1, <span class="html-italic">z</span>) hydrogen bonds and weak C–H∙∙∙O/π interactions; (<b>b</b>) crystal packing viewed along the <span class="html-italic">b</span> axis with marked 2D layer parallel to the (−102) crystallographic plane. Molecules <b>9-A</b> and <b>9-B</b> are marked in green and blue, respectively. Dashed lines indicate hydrogen bonds.</p>
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<p>(<b>a</b>) Part of the crystal structure of <b>26a</b> showing hydrogen-bonding motifs; (<b>b</b>) crystal packing in <b>26a</b> viewed along the <span class="html-italic">b</span> axis; (<b>c</b>) crystal packing in <b>26b</b> viewed down the <span class="html-italic">a</span> axis; (<b>d</b>) hydrogen-bonding patterns in crystal <b>26c</b>, (<b>e</b>) part of the crystal structure of <b>26c</b> in view along the <span class="html-italic">a</span> axis. Dashed lines indicate inter- and intramolecular interactions.</p>
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<p>Synthesis of the hydrazides of 2-, 3- or 4-iodobenzoic acid.</p>
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<p>Synthesis of the acylhydrazones of 2-, 3- or 4-iodobenzoic acid.</p>
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18 pages, 357 KiB  
Review
Hypoxia as a Target for Combination with Transarterial Chemoembolization in Hepatocellular Carcinoma
by Zizhuo Wang, Qing Li and Bin Liang
Pharmaceuticals 2024, 17(8), 1057; https://doi.org/10.3390/ph17081057 (registering DOI) - 11 Aug 2024
Viewed by 348
Abstract
Hypoxia is a hallmark of solid tumors, including hepatocellular carcinoma (HCC). Hypoxia has proven to be involved in multiple tumor biological processes and associated with malignant progression and resistance to therapy. Transarterial chemoembolization (TACE) is a well-established locoregional therapy for patients with unresectable [...] Read more.
Hypoxia is a hallmark of solid tumors, including hepatocellular carcinoma (HCC). Hypoxia has proven to be involved in multiple tumor biological processes and associated with malignant progression and resistance to therapy. Transarterial chemoembolization (TACE) is a well-established locoregional therapy for patients with unresectable HCC. However, TACE-induced hypoxia regulates tumor angiogenesis, energy metabolism, epithelial-mesenchymal transition (EMT), and immune processes through hypoxia-inducible factor 1 (HIF-1), which may have adverse effects on the therapeutic efficacy of TACE. Hypoxia has emerged as a promising target for combination with TACE in the treatment of HCC. This review summarizes the impact of hypoxia on HCC tumor biology and the adverse effects of TACE-induced hypoxia on its therapeutic efficacy, highlighting the therapeutic potential of hypoxia-targeted therapy in combination with TACE for HCC. Full article
(This article belongs to the Special Issue Novel Therapeutic Target for Hepatocellular Carcinoma)
12 pages, 1531 KiB  
Article
Blistering Behavior of Beryllium and Beryllium Alloy under High-Dose Helium Ion Irradiation
by Ping-Ping Liu, Qi-Cong Wang, Yu-Mei Jia, Wen-Tuo Han, Xiao-Ou Yi, Qian Zhan and Fa-Rong Wan
Materials 2024, 17(16), 3997; https://doi.org/10.3390/ma17163997 (registering DOI) - 11 Aug 2024
Viewed by 224
Abstract
Beryllium (Be) has been selected as the solid neutron multiplier material for a tritium breeding blanket module in ITER, which is also the primary option of the Chinese TBM program. But the irradiation swelling of beryllium is severe under high temperature, high irradiation [...] Read more.
Beryllium (Be) has been selected as the solid neutron multiplier material for a tritium breeding blanket module in ITER, which is also the primary option of the Chinese TBM program. But the irradiation swelling of beryllium is severe under high temperature, high irradiation damage and high doses of transmutation-induced helium. Advanced neutron multipliers with high stability at high temperature are desired for the demonstration power plant (DEMO) reactors and the China Fusion Engineering Test Reactor (CFETR). Beryllium alloys mainly composed of Be12M (M is W or Ti) phase were fabricated by HIP, which has a high melting point and high beryllium content. Beryllium and beryllide (Be12Ti and Be12W) samples were irradiated by helium ion with 30 keV and 1 × 1018 cm−2 at RT. The microstructures of Be, Be12Ti and Be12W samples were analyzed by SEM and TEM before and after ion irradiation. The average size of the first blistering on the surface of Be-W alloy is about 0.8 μm, and that of secondary blistering is about 79 nm. The surface blistering rates of the beryllium and beryllide samples were also compared. These results may provide a preliminary experimental basis for evaluating the irradiation swelling resistance of beryllium alloy. Full article
22 pages, 14183 KiB  
Article
Microwave Bow-Tie Diodes on Bases of 2D Semiconductor Structures
by Steponas Ašmontas, Maksimas Anbinderis, Aurimas Čerškus, Jonas Gradauskas, Andžej Lučun and Algirdas Sužiedėlis
Crystals 2024, 14(8), 720; https://doi.org/10.3390/cryst14080720 (registering DOI) - 11 Aug 2024
Viewed by 158
Abstract
Planar microwave bow-tie diodes on bases of selectively doped semiconductor structures are successfully used in the detection and imaging of electromagnetic radiation in millimeter and submillimeter wavelength ranges. Although the signal formation mechanism in these high-frequency diodes is said to be based on [...] Read more.
Planar microwave bow-tie diodes on bases of selectively doped semiconductor structures are successfully used in the detection and imaging of electromagnetic radiation in millimeter and submillimeter wavelength ranges. Although the signal formation mechanism in these high-frequency diodes is said to be based on charge-carrier heating in a semiconductor in a strong electric field, the nature of the electrical signal across the bow-tie diodes is not yet properly identified. In this research paper, we present a comprehensive study of a series of various planar bow-tie diodes, starting with a simple asymmetrically shaped submicrometer-thick n-GaAs layer and finishing with bow-tie diodes based on selectively doped GaAs/AlGaAs structures of different electrical conductivity. The planar bow-tie diodes were fabricated on two different types of high-resistivity substrates: bulky semi-insulating GaAs substrate and elastic dielectric polyimide film of micrometer thickness. The microwave diodes were investigated using DC and high-frequency probe stations, which allowed us to examine a sufficient number of diodes and collect a large amount of data to perform a statistical analysis of the electrical parameters of these diodes. The use of probe stations made it possible to analyze the properties of the bow-tie diodes and clarify the nature of the detected voltage in the dark and under white-light illumination. The investigation revealed that the properties of various bow-tie diodes are largely determined by the energy states residing in semiconductor bulk, surface, and interfaces. It is most likely that these energy states are responsible for the slow relaxation processes observed in the studied bow-tie diodes. Full article
(This article belongs to the Section Inorganic Crystalline Materials)
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Figure 1
<p>Schematic view of bow-tie diodes of asymmetric configuration: (<b>a</b>) crystal diode; (<b>b</b>) filmy diode.</p>
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<p>Schematic view of asymmetric (AD) and symmetric (SD) bow-tie diodes.</p>
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<p>Cross-section of the investigated semiconductor structures and their energy band diagrams, showing the electron density distribution: (<b>a</b>) a heavily doped thick <span class="html-italic">n</span>-GaAs layer of submicrometric dimension epitaxially grown onto a non-intentionally doped <span class="html-italic">i</span>-GaAs layer (TG structure); (<b>b</b>) a selectively doped GaAs/AlGaAs structure without a spacer (SDWS structure); (<b>c</b>) a selectively doped GaAs/AlGaAs structure with a thick spacer (SDTS structure); (<b>d</b>) a selectively doped GaAs/AlGaAs structure with a homogeneously doped barrier (SDHD structure); (<b>e</b>) a selectively doped GaAs/AlGaAs structure with a delta-doped barrier (SDDD structure).</p>
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<p>Statistical representation of the voltage sensitivity of various bow-tie diodes in the illuminated and unilluminated scenarios. SD and AD denote symmetric and asymmetric bow-tie diodes, respectively, with <span class="html-italic">d</span> indicating the width of the diode’s narrowest part in micrometers. Positive values of <math display="inline"><semantics> <mi>S</mi> </semantics></math> correspond to the polarity of the thermal electromotive force of hot electrons.</p>
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<p>Statistical representation of the low-field electrical resistance of the bow-tie diodes in the dark and under illumination. SD and AD denote symmetric and asymmetric bow-tie diodes, with <span class="html-italic">d</span> indicating the width of the diode’s narrowest part in micrometers. The short dotted lines show the theoretical values calculated using Equation (4).</p>
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<p>Statistical data of the asymmetry of <span class="html-italic">I-V</span> characteristic of various bow-tie diodes, both illuminated and in the dark. SD and AD denote the bow-tie diodes, with <span class="html-italic">d</span> indicating the width of the neck in micrometers.</p>
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<p>Statistical data of the asymmetry of <span class="html-italic">I-V</span> characteristic of various bow-tie diodes, both illuminated and in the dark. SD and AD denote the bow-tie diodes, with <span class="html-italic">d</span> indicating the width of the neck in micrometers.</p>
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<p>Statistical representation of the non-linearity coefficient of the <span class="html-italic">I-V</span> characteristics of various bow-tie diodes, both illuminated and in the dark. SD and AD denote the bow-tie diodes, with the corresponding width of the neck <span class="html-italic">d</span> in micrometers.</p>
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<p>Statistical representation of the non-linearity coefficient of the <span class="html-italic">I-V</span> characteristics of various bow-tie diodes, both illuminated and in the dark. SD and AD denote the bow-tie diodes, with the corresponding width of the neck <span class="html-italic">d</span> in micrometers.</p>
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<p>Dependences of the nonlinearity coefficient <math display="inline"><semantics> <mi>β</mi> </semantics></math> of the <span class="html-italic">I-V</span> characteristic of test structures on distance <math display="inline"><semantics> <mi>L</mi> </semantics></math> between the ohmic contacts when the structures were in the dark and when they were illuminated: (<b>a</b>) histograms of <math display="inline"><semantics> <mi>β</mi> </semantics></math> versus <math display="inline"><semantics> <mi>L</mi> </semantics></math>; (<b>b</b>) the dependence of the ratio <math display="inline"><semantics> <mrow> <mi>β</mi> <mfenced> <mi>L</mi> </mfenced> <mo>/</mo> <mi>β</mi> <mfenced> <mrow> <mn>10</mn> <mo> </mo> <mrow> <mi mathvariant="sans-serif">μ</mi> <mi mathvariant="normal">m</mi> </mrow> </mrow> </mfenced> </mrow> </semantics></math> on <math display="inline"><semantics> <mi>L</mi> </semantics></math>.</p>
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<p>Photoluminescence spectra of the investigated structures at room temperature: (<b>a</b>) normalized CWPL spectra. The numbers in parentheses next to the spectra show the ratio between the main PL peaks of the samples and the peak of the TG sample.; (<b>b</b>) TRPL spectra. The spectra are shifted vertically for clarity.</p>
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<p>The dependence of the electrical resistance between ohmic contacts of the TLM test structure on the distance between the contacts <span class="html-italic">L</span> (dots). The red line marks the linear approximation of the experimental points; <span class="html-italic">R<sub>c</sub></span> denotes the contact resistance of the contacts, which forms half of the segment cut by the approximate line on the ordinate axis from 0 to the intersection with this axis; <span class="html-italic">w</span> = 100 μm is the width of the mesa of the test structure.</p>
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<p>Spectrum of the photo-lamp.</p>
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<p>Approximation of the current strength in the crystal AD1 bow-tie diode on the base of the SDHD structure, using Equation (7): (<b>a</b>) under illumination; (<b>b</b>) in the dark.</p>
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<p>The I-V characteristics of AD1 bow-tie diodes (<b>a</b>) and the dependencies of the resistance of the diodes on the applied voltage (<b>b</b>) of all studied structures in the dark and under illumination.</p>
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