ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The purpose of this study was to evaluate the reactivity and the effect of concentration of three... more The purpose of this study was to evaluate the reactivity and the effect of concentration of three tertiary amines upon the mechanical properties of a chemical curing dental composite. Chemical cured composite pastes were prepared by keeping peroxide concentration constant at 1 wt% (by weight of resin mixture) and by varying the amine/peroxide molar ratio from 0.25 to 1.5. Composite samples were prepared for all three amine pastes aged for 1, 15, 30, 45, and 60 d stored at 8, 22, and 37 degrees C. The loss in activity of the tertiary amine with time was measured. Changes in compressive strength, diametral tensile strength, and microhardness were also measured. A sharp decrease in working and setting times corresponding to increased activity was noticed with an increased amine content. The activity was found to vary in the order N,N-dimethyl p-toluidine (DMPT) > 2-(4-dimethylaminophenyl)ethanol (DMAPEA) > N,Ndiethanol p-toluidine (DEPT). DMPT is found to be more temperature sensitive than DMAPEA and DEPT. However, DEPT is found to provide better storage stability out of all three amines tested. Each amine was found to possess optimum concentrations at which the mechanical properties showed maximum values. DEPT is preferred for long-term storage stability in chemical-cured dental composites where aging tends to reduce the activity of the amine.
... (II) + (Yl CHCLj C H2-N R1 (m) (UII) SCHEME 1 ... The NN'-difox-myl deriva-Craig for the... more ... (II) + (Yl CHCLj C H2-N R1 (m) (UII) SCHEME 1 ... The NN'-difox-myl deriva-Craig for the preparation of NNN'W-tetraphenyl-tive of 2-arnino-5-methyl-N-$-tolylbenzylamine (VII ; Part IV, RB Roy and G. A. Swan, J . Chenz. SOC. (C), 1969, R1 ...
The development of heterogeneous catalysts for fine chemicals synthesis has become a major area o... more The development of heterogeneous catalysts for fine chemicals synthesis has become a major area of research recently, as the potential advantages of these materials (simplified recovery and reusability, the potential for incorporation in continuous reactors and microreactors) ...
In the present study, we have analyzed the response of human smooth muscle cell (SMC)s to oxidati... more In the present study, we have analyzed the response of human smooth muscle cell (SMC)s to oxidative stress, in terms of recruitment of key elements of the stress-activated protein kinase (SAPK) pathway, such as Rac(1), p38, and the small heat shock protein (HSP)27. The level of expression of three small HSPs, alphaB-crystallin, HSP20, HSP27, as well as the phosphorylation levels of HSP27 and p38, were higher in cultured, asynchronously growing SMCs originating from left interior mammary artery (LIMA) than those originating from aorta, saphenous vein, and umbilical vein, validating the choice of SMCs from LIMA as a model system in our study. In synchronized, quiescent SMCs from LIMA, oxidative stress (H(2)O(2) stimulation)-induced membrane translocation of Rac(1), p38 phosphorylation, membrane translocation, and phosphorylation of HSP27. In these cells, simvastatin (S), an HMG-CoA reductase inhibitor, blocked, in a mevalonate-dependent way, oxidative stress-induced membrane translocation of Rac(1). However, S pretreatment prior to oxidative stress increased the levels of p38 phosphorylation, HSP27 membrane translocation/phosphorylation, actin polymerization, and apoptosis in these cells, in a mevalonate-dependent way. These results establish that S pretreatment has a stimulatory effect on the stress-activated p38/HSP27 pathway, despite its blocking effect on Rac(1) activation.
Carbonnitrogen bond forming reactions are one of the most widely used methodologies for the synt... more Carbonnitrogen bond forming reactions are one of the most widely used methodologies for the synthesis of biologically active molecules. N-arylheterocycles and benzyl amines are common motifs in pharmaceutical research [1]. Usually these compounds were synthesized via S ...
... The FTIR of chemically modified silica (imine) shows peak due to C N around 1640 cm −1 , whic... more ... The FTIR of chemically modified silica (imine) shows peak due to C N around 1640 cm −1 , which on complexation with copper shifts to lower value [12b]. The lowering in frequencies of the C N peak is indicative of the formation of metalligand bond. ...
Harmful Algal Blooms (HAB's) are a major concern all over the world due to their negative impacts... more Harmful Algal Blooms (HAB's) are a major concern all over the world due to their negative impacts on the marine environment, human health, and the economy. Their detection from space still remains a challenge particularly in turbid coastal waters. In this study we propose a simple reflectance band difference approach for use with Medium Resolution Imaging Spectrometer (MERIS) data to detect intense plankton blooms. For convenience we label this approach as the Extreme Bloom Index (EBI) which is defined as EBI = Rrs (709) - Rrs (665). Our initial analysis shows that this band difference approach has some advantages over the band ratio approaches, particularly in reducing errors due to imperfect atmospheric corrections. We also do a comparison between the proposed EBI technique and the Maximum Chlorophyll Index (MCI) Gower technique. Our preliminary result shows that both the EBI and MCI indeces detect intense plankton blooms, however, MCI is more vulnerable in highly scattering waters, giving more positive false alarms than EBI.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The purpose of this study was to evaluate the reactivity and the effect of concentration of three... more The purpose of this study was to evaluate the reactivity and the effect of concentration of three tertiary amines upon the mechanical properties of a chemical curing dental composite. Chemical cured composite pastes were prepared by keeping peroxide concentration constant at 1 wt% (by weight of resin mixture) and by varying the amine/peroxide molar ratio from 0.25 to 1.5. Composite samples were prepared for all three amine pastes aged for 1, 15, 30, 45, and 60 d stored at 8, 22, and 37 degrees C. The loss in activity of the tertiary amine with time was measured. Changes in compressive strength, diametral tensile strength, and microhardness were also measured. A sharp decrease in working and setting times corresponding to increased activity was noticed with an increased amine content. The activity was found to vary in the order N,N-dimethyl p-toluidine (DMPT) > 2-(4-dimethylaminophenyl)ethanol (DMAPEA) > N,Ndiethanol p-toluidine (DEPT). DMPT is found to be more temperature sensitive than DMAPEA and DEPT. However, DEPT is found to provide better storage stability out of all three amines tested. Each amine was found to possess optimum concentrations at which the mechanical properties showed maximum values. DEPT is preferred for long-term storage stability in chemical-cured dental composites where aging tends to reduce the activity of the amine.
... (II) + (Yl CHCLj C H2-N R1 (m) (UII) SCHEME 1 ... The NN'-difox-myl deriva-Craig for the... more ... (II) + (Yl CHCLj C H2-N R1 (m) (UII) SCHEME 1 ... The NN'-difox-myl deriva-Craig for the preparation of NNN'W-tetraphenyl-tive of 2-arnino-5-methyl-N-$-tolylbenzylamine (VII ; Part IV, RB Roy and G. A. Swan, J . Chenz. SOC. (C), 1969, R1 ...
The development of heterogeneous catalysts for fine chemicals synthesis has become a major area o... more The development of heterogeneous catalysts for fine chemicals synthesis has become a major area of research recently, as the potential advantages of these materials (simplified recovery and reusability, the potential for incorporation in continuous reactors and microreactors) ...
In the present study, we have analyzed the response of human smooth muscle cell (SMC)s to oxidati... more In the present study, we have analyzed the response of human smooth muscle cell (SMC)s to oxidative stress, in terms of recruitment of key elements of the stress-activated protein kinase (SAPK) pathway, such as Rac(1), p38, and the small heat shock protein (HSP)27. The level of expression of three small HSPs, alphaB-crystallin, HSP20, HSP27, as well as the phosphorylation levels of HSP27 and p38, were higher in cultured, asynchronously growing SMCs originating from left interior mammary artery (LIMA) than those originating from aorta, saphenous vein, and umbilical vein, validating the choice of SMCs from LIMA as a model system in our study. In synchronized, quiescent SMCs from LIMA, oxidative stress (H(2)O(2) stimulation)-induced membrane translocation of Rac(1), p38 phosphorylation, membrane translocation, and phosphorylation of HSP27. In these cells, simvastatin (S), an HMG-CoA reductase inhibitor, blocked, in a mevalonate-dependent way, oxidative stress-induced membrane translocation of Rac(1). However, S pretreatment prior to oxidative stress increased the levels of p38 phosphorylation, HSP27 membrane translocation/phosphorylation, actin polymerization, and apoptosis in these cells, in a mevalonate-dependent way. These results establish that S pretreatment has a stimulatory effect on the stress-activated p38/HSP27 pathway, despite its blocking effect on Rac(1) activation.
Carbonnitrogen bond forming reactions are one of the most widely used methodologies for the synt... more Carbonnitrogen bond forming reactions are one of the most widely used methodologies for the synthesis of biologically active molecules. N-arylheterocycles and benzyl amines are common motifs in pharmaceutical research [1]. Usually these compounds were synthesized via S ...
... The FTIR of chemically modified silica (imine) shows peak due to C N around 1640 cm −1 , whic... more ... The FTIR of chemically modified silica (imine) shows peak due to C N around 1640 cm −1 , which on complexation with copper shifts to lower value [12b]. The lowering in frequencies of the C N peak is indicative of the formation of metalligand bond. ...
Harmful Algal Blooms (HAB's) are a major concern all over the world due to their negative impacts... more Harmful Algal Blooms (HAB's) are a major concern all over the world due to their negative impacts on the marine environment, human health, and the economy. Their detection from space still remains a challenge particularly in turbid coastal waters. In this study we propose a simple reflectance band difference approach for use with Medium Resolution Imaging Spectrometer (MERIS) data to detect intense plankton blooms. For convenience we label this approach as the Extreme Bloom Index (EBI) which is defined as EBI = Rrs (709) - Rrs (665). Our initial analysis shows that this band difference approach has some advantages over the band ratio approaches, particularly in reducing errors due to imperfect atmospheric corrections. We also do a comparison between the proposed EBI technique and the Maximum Chlorophyll Index (MCI) Gower technique. Our preliminary result shows that both the EBI and MCI indeces detect intense plankton blooms, however, MCI is more vulnerable in highly scattering waters, giving more positive false alarms than EBI.
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