Search Results (3,000)

Integrated gate commutated thyristors (IGCTs) are critical components in high-voltage, high-current, and high-power conversion systems, particularly in offshore wind energy systems. However, the working environment of offshore wind energy conversion systems is extremely harsh. In this article, we propose an active damage control approach aiming at enhancing the reliability of the conversion system. By employing electro-thermal modeling for the equipment of the offshore wind energy conversion system, the junction temperature and fatigue damage of IGCT are simulated during the operation process. Using the improved model predictive current control (MPCC) method, active damage control effectively regulates the switching frequency of IGCT. IGCTs are symmetrically distributed on each leg of the converter, so the lifespan of the two IGCTs on each leg is also considered to be similar. This method balances the life of the IGCTs on the three legs of the converter and optimizes their utilization to the maximum extent. These measures effectively enhance the reliability of the conversion system and lower the operation and maintenance cost of high-power IGCT converters. The effectiveness of the proposed method is validated by co-simulation results by ANSYS and MATLAB/Simulink. Full article

Prior research has demonstrated that incorporating solid waste from various sources, such as plastics, civil engineering waste, and industrial and mining waste, into pavement and civil works mixes has notable environmental benefits. This includes reducing the over-exploitation of aggregate banks and preventing waste materials from being deposited in open-pit landfills for extended periods. This review focuses on sustainable aggregates produced from solid waste with rheological or mechanical properties suitable for replacing conventional aggregates in asphalt or hydraulic concrete mixtures. The aim is to determine the optimal replacement percentage in the mixture to directly impact pavement performance. This review also delves into the impact on fatigue resistance and permanent deformation based on the type of waste material used in construction. Additionally, using sustainable aggregates presents added benefits for pavement binders, such as inhibiting reflection cracks, reducing traffic noise, and prolonging the service life of the pavement. However, it is crucial to study the percentage of replacement of sustainable aggregates in conjunction with other materials using mathematical models and simulations to ensure a substantial contribution to the sustainability of the construction industry. Full article

Atrial fibrillation (AF) is the most common heart rhythm disorder in the Western world. Between the years 2010 and 2019, the global prevalence of AF rose from 33.5 million to 59 million, highlighting the importance of developing equitable treatments for patients. The disease is associated with symptoms such as palpitations, dizziness, fatigue, shortness of breath, and cognitive dysfunction. In addition, AF increases the risk of developing a stroke and heart failure. Despite new insights into risk factors that can lead to the development of AF, the success of current treatments is suboptimal. Numerous risk factors, such as hypertension, diabetes, and obesity, have been associated with the development and progression of AF. As these can be lifestyle-related risk factors, lifestyle modification may be a solution to reduce AF-related symptoms as well as episodes. Research results show that certain dietary changes can reduce AF and numerous risk factors for AF. Increasing attention is being given to Mediterranean and whole, plant-based eating patterns, which emphasize eating grains, legumes, vegetables, fruits, and nuts, while excluding most—or all—animal products. Hence, what are the beneficial aspects of a Mediterranean and plant-based diet which consists mainly of unprocessed foods? In the current review, we discuss the outcomes of diet-based treatments. Moreover, other diet-related treatments, brought up by patient initiatives, are highlighted. These patient-initiated studies include L-glutamine and electrolytes as options to manage AF. Also, we highlight the emerging importance of valuing patient needs and a quality-of-life-centered approach to medicine. As indicated by recent studies and patient experiences, citizen science can create inclusive solutions that lead to patient empowerment and a holistic approach for AF management. Full article

Breast cancer (BC) is the most common invasive neoplasm and affects many women of working age. The return to work (RTW) of female survivors (BCSs) is associated with a better quality of life and longer survival. A tailored intervention to promote RTW was launched in 2022. A year later, the women were contacted to find out if RTW had occurred regularly and what their health conditions were compared to the baseline. BCSs reported excessive fatigue, poor sleep quality, anxiety, depression and reduced work ability; these parameters had not improved significantly compared to the baseline. Thematic analysis of the interviews confirmed the presence of personal, company, and societal factors that could hinder or favor RTW. The interviews demonstrated that, even in an economically developed country that has provided numerous benefits for BCSs, protection is not always effective. Personalized intervention seems necessary to complete the process of reintegrating BCSs into their future working careers. Full article

Background: Fatigue with obesity negatively affects the motivation to lose weight and causes failure of treatment. So, obesity and fatigue are two related entities that worsen each other in a vicious circle. This study aimed to examine the changes in fatigue levels in obese patients undergoing laparoscopic sleeve gastrectomy (LSG). Methods: Preoperative and postoperative BMI, fat percentage, and obesity degree were determined based on Tanita test results, and the rates of change were calculated. The Fatigue Assessment Scale (FAS) was used to assess the impact of obesity on mental and physical fatigue. Results: Six months after LSG, there was a 29.7% decrease in Body Mass Index (BMI) across all patients (45.0 to 31.4, p < 0.001). Significant reductions in the percentage of body fat, obesity grade, and HgA1C were observed in both women and men and overall (p < 0.001 for all comparisons). Scores on the Fatigue Assessment Scale (FAS) for total, mental, and physical scales decreased significantly for women, men, and all participants (p < 0.001 for all comparisons). There was a weak but significant positive correlation between the percentage change in FAS total and FAS physical scale scores and the change in BMI% (p = 0.015 and 0.004; r = 0.089, 0.106, respectively). Change in obesity grade and FAS physical subscale scores negatively correlated (p = 0.029, r = 0.080). Conclusions: LSG not only leads to significant weight reduction but also improves fatigue levels in patients with obesity. Full article

Background: Dissection of the axillary lymph nodes during surgery for breast cancer with lymph node involvement is burdened by a complication: lymphedema. Approximately half of women undergoing axillary dissection suffer from it, with a notable impact in terms of perceived discomfort, presented quality of life, and alteration of body image. There is also no shortage of problems in the patient’s social and professional life. Methods: The present review aims to select Randomized Controlled Trials (RCTs) present in the literature regarding the effects of yoga as an alternative therapy in patients with breast cancer-related lymphedema. A search of four databases was undertaken: Cochrane, Pubmed, Scopus, and Web of Science. The searches were conducted on 19 May 2024, and updated to 30 June 2024 without date limits. RCTs without language limitations, in any context, and with any yoga variant were considered. Results: The postulated search strings highlighted a total of 69 potentially eligible studies. The study selection system consisted of two levels of screening, (1) abstract selection and (2) full-text selection, for a total of three studies included in the review. The three RCTs included involved mixed treatment sessions in an outpatient setting with a yoga teacher and at home using a DVD. In the various studies, the outcome measures concerned quality of life, ROM, spinal mobility, limb volume, and tissue induration. Conclusions: According to the analysis of the data obtained, yoga as an alternative therapy could be useful if combined with the usual care routine in women with lymphedema related to sensory cancer, in terms of improving physical, professional, and emotional quality of life and reducing symptoms such as fatigue, pain, and insomnia. Furthermore, yoga could bring about a reduction in tissue induration of the limb, greater spinal mobility evaluated in terms of improvement of the pelvic and kyphotic angle, and greater strength in shoulder abduction. Full article

A bimetallic steel bar (BSB) consisting of stainless-steel cladding and carbon steel substrate exhibits excellent corrosion resistance and good mechanical properties. The bimetallic structure of BSBs may affect their low-cycle fatigue performance, and current investigations on the above issue are limited. In this study, the low-cycle fatigue properties of bimetallic steel bars (BSBs) with inelastic buckling were investigated. Experiments and numerical studies were conducted to investigate the low-cycle fatigue capacity for BSBs, considering buckling. The buckling mode of BSBs is discussed. The hysteretic loops and energy properties of BSBs with various slenderness ratios (L/D) and fatigue strain amplitudes (ε_a) are investigated. With increases in the L/D and ε_a, the original symmetry for hysteresis loops disappears gradually, which is caused by the buckling. A predictive equation revealing the relation between the ε_a and fatigue life is suggested, which considers the effects of the L/D. A numerical modelling method is suggested to predict the hysteretic curves of BSBs. The effect of buckling on the stress and energy properties of BSBs is discussed through the numerical analysis of 44 models including the effects of the L/D, ε_a, and cladding ratios. The numerical analysis results illustrate that the hysteresis loops of BSBs with various ε_a values exhibit similar shapes. The increase in the cladding ratio reduces the peak stress and the dissipated energy properties of BSBs. The hysteresis loop energy density decreases by about 3% with an increase of 0.1 in the cladding ratio. It is recommended that the proportion of stainless steel inBSBs should be minimized once the corrosion resistance requirements are met. Full article

Inclusions are an important parameter affecting the fatigue life of materials. In this paper, the type, size, and quantity of inclusions in bearing steel were quantitatively analyzed using scanning electron microscopy and automatic scanning electron microscopy with an X-ray energy dispersive spectroscopy function. The effects of the inclusion parameters and positions on the rotating bending fatigue properties were analyzed using the rotating bending fatigue test. The results proved that for samples 1 and 2, the inclusions were mainly sulfides, Ti-containing inclusions, and their composite inclusions. For samples 3 and 4, the inclusions were mainly oxides or sulfide–oxide complexes. The number and maximum size of inclusions in sample 2 were relatively small. This was mainly due to the difference in the content of Al, S, and Ca elements in the different samples. The inclusion distance to the surface and the maximum inclusion size had a larger influence on the rotating bending fatigue life in comparison to the inclusion type. Moreover, nitride–oxides had a more detrimental effect on the rotating bending fatigue life as compared to the sulfide–oxide complex inclusions. A model was established on the basis of the inclusion size, depth, and stress by using the Python software. The simulation demonstrated that using five parameters fit well with the experiment results. Full article

Ethnic and racial sexual minority men with HIV have a disproportionately higher risk of HIV-related cardiovascular disease (CVD). There is a lack of tailored and culturally salient behavioral interventions to address HIV-related chronic illness in ethnic and racial sexual minority men, and literature on their understanding and awareness of modifiable behavioral risks is limited. The purpose of this study was to assess illness perceptions about HIV and HTN, and describe physical activity, tobacco, and e-cigarette use in Black and Latinx sexual minority men living with HIV. We used the validated Illness Perception Questionnaire-Revised (IPQ-R) to assess perceptions about two interrelated chronic diseases, HIV and CVD. To assess CVD behavioral risk, we assessed physical activity using the International Physical Activity Questionnaire. Tobacco and e-cigarette use were assessed using items from the Behavioral Risk Factor Surveillance System. Sleep difficulties were the most prevalent symptom attributed to HIV, and were statistically associated with fatigue, upset stomach, and loss of strength. Anxiety was reported to be caused by HIV (57%) and HTN (39%). Half of the participants engaged in vigorous activity for 128 min (SD = 135) daily, and 63% engaged in moderate activity for 94 min (SD = 88) daily. Over a third reported current tobacco use and 20% reported current e-cigarette use. This study provides formative data to better understand how Black and Latinx sexual minority men with HIV perceive intersecting chronic illnesses and their engagement in modifiable CVD risk behaviors. Sleep, mental health disparities, and financial hardships were commonly reported. More research is needed to address intersecting chronic illnesses and mental health conditions that are influenced by social positioning over the life course, and impact CVD risk factors. This study was not registered. Full article

Cystinosis is a rare autosomal recessive disorder in which cystine crystals accumulate within the cellular lysosomes, causing damage to multiple organs. Due to challenges with the stringent cysteamine treatment regimen and side effects, adherence is often sub-optimal. This study aimed to assess the level of adherence to cysteamine therapy among cystinosis patients in Saudi Arabia and its impact on their quality of life. Electronic medical record data of 39 cystinosis patients from the Department of Nephrology at King Faisal Specialist Hospital and Research Center in Saudi Arabia were reviewed, and 25 patients were included in this study. Out of the 25 patients included in the final analysis, 64% (n = 16) were female. The mean age was 19.04 years. Almost all patients (23/25, 92%) were on oral IR cysteamine therapy, and 52% (13/25) were on topical cysteamine eye drop treatment. Of the 15 patients who responded to the Morisky Medication Adherence Scale-8 (MMAS-8) questionnaire, only 4 (26.7%) were highly adherent to cysteamine therapy. Most of the respondents (7/15, 46.7%) showed a medium level of treatment adherence. Based on the medication possession ratio for oral cysteamine, only 6 out of 23 patients (26.1%) were found to be 96–100% adherent. For the cysteamine eye drops, only 5/13 patients (38.4%) were 76–95% adherent. The 36-Item Short Form Health Survey (SF-36) used to assess patients’ health-related outcomes showed that their quality of life was affected in the domains of ‘social functioning’ and ‘energy/fatigue.’ Despite a small sample size, this study shows sub-optimal adherence to cysteamine treatment in patients from Saudi Arabia. The possible reasons for low treatment adherence could be a high frequency of administration and treatment-related side effects. Full article

Paroxysmal nocturnal haemoglobinuria (PNH) is a rare, potentially life-threatening haematological disease characterised by chronic complement-mediated haemolysis with multiple clinical consequences that impair quality of life. This post hoc analysis assessed haematological and clinical responses to the first targeted complement C3 inhibitor pegcetacoplan in patients with PNH and impaired bone marrow function in the PEGASUS (NCT03500549) and PRINCE (NCT04085601) studies. For patients with impaired bone marrow function, defined herein as haemoglobin <10 g/dL and absolute neutrophil count <1.5 × 10⁹ cells/L, normalisation of the parameters may be difficult. Indeed, 20% and 43% had normalised haemoglobin in PEGASUS and PRINCE, respectively; 60% and 57% had normalised LDH, and 40% and 29% had normalised fatigue scores. A new set of parameters was applied using changes associated with clinically meaningful improvements, namely an increase in haemoglobin to ≥2 g/dL above baseline, decrease in LDH to ≤1.5× the upper limit of normal, and an increase in fatigue scores to ≥5 points above baseline. With these new parameters, 40% and 71% of PEGASUS and PRINCE patients had improved haemoglobin; 60% and 71% had an improvement in LDH, and 60% and 43% had an improvement in fatigue scores. Thus, even patients with impaired bone marrow function may achieve clinically meaningful improvements with pegcetacoplan. Full article

This paper investigates the impact of various manufacturing parameters on the mechanical and tribological properties of high-performance PLA (polylactic acid) parts produced using Fused Filament Fabrication (FFF). It addresses the challenges associated with optimizing additive manufacturing processes, particularly for polymer-based materials, and emphasizes the importance of understanding how factors such as build orientation, layer thickness, and infill density influence the final properties of the printed parts. This study highlights the improvements that can be achieved by incorporating reinforcements such as carbon fibers and graphene nanoplatelets into PLA, enhancing its mechanical strength and wear resistance. Experimental results show that optimizing printing parameters can significantly reduce the coefficient of friction and wear, leading to better performance in applications involving movement and mechanical stress. Key findings include the observation that higher infill densities and specific build orientations improve the fatigue life and tensile strength of PLA parts. Additionally, post-printing thermal treatments can alleviate internal stresses and enhance interlayer adhesion, further improving mechanical properties. The article concludes that with proper optimization, high-performance PLA can be a viable material for industrial applications, offering both environmental benefits and enhanced performance. Full article

Background: Long COVID-19 syndrome remains a global public health problem, with more than 145 million people affected with multisystemic symptoms. Addressing the requirements of individuals impacted by a syndrome characterised by a complex and variable clinical presentation is of utmost importance. Identifying the variables that can exert influence and understanding their progression is essential for directing treatment strategies aimed at enhancing both independence and quality of life. Therefore, the aim of this study was to analyse the influence of sociodemographic and clinical variables on existence and their relationship with asthenia, anxiety symptoms and low mood. Methods: An analytical study secondary to an observational cross-sectional descriptive study. Results: Logistic regression showed significant univariate effects on asthenia [sex (p = 0.034); age (p = 0.042); Activities of Daily Living Questionnaire [ADQL (p = 0.002)] [physical functioning (p < 0.001) and general health (p = 0.014)] and multivariate [sex (p = 0.019), adult age (p = 0.01) and physical functioning (p = 0.04)]]; low mood [time of evolution (p = 0.028) and multivariate [time course (p = 0.007), ADLQ (p = 0.011), role physical (p = 0.013) and general health (p = 0.001)]] and anxiety [physical functioning (p = 0.046) and multivariate [physical functioning (p = 0.034), age (p = 0.011), time of evolution (p = 0.001) and ADQL (p = 0.011)]]. Conclusions: Increased age, gender and longer evolution time seem to favour the prevalence and occurrence of mental health symptoms; greater independence and good physical functioning are protective factors with respect to the occurrence of mental health-related symptoms in patients affected by post-COVID-19 condition. Full article

The cyclic loading generated by injection and production operations in underground gas storage facilities can lead to fatigue damage to cement sheaths and compromise the integrity of wellbores. To investigate the influence of cyclic loading on the fatigue damage of well cement, uniaxial and triaxial loading tests were conducted at different temperatures, with maximum cyclic loading intensity ranging from 60% to 90% of the ultimate strength. Test results indicate that the compressive strength and elastic modulus of well cement subjected to monotonic loading under high-temperature and high-pressure (HTHP) testing conditions were 14–21% lower than those obtained under ambient testing conditions. The stress–strain curve exhibits stress–strain hysteresis loops during cyclic loading tests, and the plastic deformation capacity is enhanced at HTHP conditions. Notably, a higher intensity of cyclic loading results in more significant plastic strain in oil-well cement, leading to the conversion of more input energy into dissipative energy. Furthermore, the secant modulus of well cement decreased with cycle number, which is especially significant under ambient test conditions with high loading intensity. Within 20 cycles of cyclic loading tests, only the sample tested at a loading intensity of 90% ultimate strength under an ambient environment failed. For samples that remained intact after 20 cycles of cyclic loading, the compressive strength and stress–strain behavior were similar to those obtained before cyclic loading. Only a slight decrease in the elastic modulus is observed in samples cycled with high loading intensity. Overall, oil-well cement has a longer fatigue life when subjected to HTHP testing conditions compared to that tested under ambient conditions. The fatigue life of well cement increases significantly with a decrease in loading intensity and can be predicted based on the plastic strain evolution rate. Full article

A prevalent symptom among Inflammatory Bowel Disease (IBD) patients is fatigue, characterized by a persistent sense of energy depletion that affects all aspects of daily life. This review aims to evaluate nursing interventions reported in the literature to alleviate fatigue in IBD patients. A comprehensive search was conducted across four electronic databases—PubMed, CINAHL, Cochrane, and Scopus—and four scientific journals: “Gastroenterology”, “Inflammatory Bowel Disease”, “Journal of Crohn’s and Colitis”, and “United European Gastroenterology Journal”. Inclusion criteria were clinical trials involving adult IBD patients in remission or mild disease activity. Out of 234 studies, 2 were selected for review. These studies assess the effectiveness of Solution-Focused Therapy (SFT) that emphasizes solving problems and developing strategies for improvement, and Problem-Solving Therapy (PST) that focuses on identifying problems and coping strategies. SFT showed a positive impact on fatigue with a significant improvement in the Checklist Individual Strength after three months: 45.5% in the control group, 85.7% in the SFT group, and 60% in the PST group, but its impact declined over time. Additionally, SFT demonstrated potential for reducing healthcare costs compared to standard of care and PST. Further research is needed to provide nurses interventions for managing fatigue in IBD patients. The review protocol has been registered at OSF.io. Full article