A novel series of cleavable alkyltrimethylammonium surfactants with different hydrocarbon chain lengths (C8–16) were synthesized. A carbonate break site inserted between the polar head and the hydrocarbon chain makes these compounds hydrolyzable. The reagents used are renewable, (bio)degradable, or reusable. The hydrolysis of these cleavable surfactants will lead to the generation of fatty alcohols and choline, which is an essential biological nutrient. The surface activities in aqueous solution of the synthesized carbonates fulfill the requirement of being good surfactants. In addition, the cleavable compounds containing n-decyl and n-dodecyl chains showed similar or higher antimicrobial activities when compared to a non-cleavable analog. 相似文献
Journal of Materials Science - Phase separation is a relevant mode of transformation for microstructure development in multicomponent alloys. Its occurrence can drastically alter the composition... 相似文献
Both water balance (WB) and rating curve (RC) are methods for estimating streamflow. The first is mostly used to estimate reservoir outflows, while the second is usually adopted in hydrometeorological network streamflow gauges. While WB uses hourly collected data, the RC estimates streamflow using current water level and extrapolation techniques. The objective of this study was to analyze variations in the reservoir’s hourly outflow at Queimado Hydroelectric Power Plant (HPP Queimado) and to propose a method to evaluate whether the estimate of the daily outflows, obtained by the WB method, is similar to the flow values obtained at a conventional station. The logistic regression (LR) model was used because it is a method that adopts binary, categorically dependent variables to identify the event of interest. The results showed that the values of streamflow, obtained from an average of two daily readings, were a good representation of the flows in the region. The LR was able to identify atypical data, especially in the rainy season. This means that data consistency analysis can be faster and safer, when adequately employed and considering the proposed conditions, contributing to both management policies and the management of water resources.
Polycomb group (PcG) proteins are epigenetic regulators that facilitate both embryonic development and cancer progression. PcG proteins form Polycomb repressive complexes 1 and 2 (PRC1 and PRC2). PRC2 trimethylates histone H3 lysine 27 (H3K27me3), a histone mark recognized by the N-terminal chromodomain (ChD) of the CBX subunit of canonical PRC1. There are five PcG CBX paralogs in humans. CBX2 in particular is upregulated in a variety of cancers, particularly in advanced prostate cancers. Using CBX2 inhibitors to understand and target CBX2 in prostate cancer is highly desirable; however, high structural similarity among the CBX ChDs has been challenging for developing selective CBX ChD inhibitors. Here, we utilize selections of focused DNA encoded libraries (DELs) for the discovery of a selective CBX2 chromodomain probe, SW2_152F. SW2_152F binds to CBX2 ChD with a Kd of 80 nM and displays 24-1000-fold selectivity for CBX2 ChD over other CBX paralogs in vitro. SW2_152F is cell permeable, selectively inhibits CBX2 chromatin binding in cells, and blocks neuroendocrine differentiation of prostate cancer cell lines in response to androgen deprivation. 相似文献
Topics in Catalysis - Using the density functional theory, the mechanism of the water–gas shift reaction has been investigated employing a model catalyst formed by a Au5 cluster supported on... 相似文献
Viscoelastic properties of two nontraditional hydrocolloid dispersions were evaluated. Prosopis chilensis seed gum was evaluated based on temperature (5–80 °C) and added CaCl2 (0.07%), whereas nopal mucilage was evaluated based on temperature (5–80 °C) and sucrose concentration (0–20%). Viscoelasticity was tested by the small strain oscillatory shear test; storage modulus (G′), loss modulus (G″) and tan δ were reported. Prosopis chilensis and nopal dispersions behaved as weak gels (G’ > G’’) regardless of experimental condition. Raising temperature from 20 to 80 °C significantly increased G’. The gel structure was strengthened by adding CaCl2 and G’ increased at 40 °C. The sucrose effect depended on concentration and temperature; at low sucrose concentrations, G’ modulus increased regardless of temperature level, but at high concentrations, it decreased at temperatures >40 °C. In conclusion, nopal and Prosopis chilensis dispersions show weak gel structure regardless of experimental condition. G′ increases as temperature increases, and these dispersions could be suitable for food applications requiring heat tolerance. 相似文献
Tannase is an enzyme used in various industries and produced by a large number of microorganisms. The aim of this study was to evaluate tannase production to determine the biochemical, kinetic, and thermodynamic properties and to simulate tannase in vitro digestion. The tannase-producing fungal strain was isolated from “jamun” leaves and identified as Aspergillus tamarii. Temperature at 26°C for 67?h was the best combination for maximum tannase activity (6.35-fold; initial activity in Plackett–Burman design—15.53?U/mL and average final activity in Doehlert design—98.68?U/mL). The crude extract of tannase was optimally active at 40°C, pH 5.5 and 6.5. Moreover, tannase was stimulated by Na+, Ca2+, Mg2+, and Mn2+. The half-life at 40°C lasted 247.55?min. The free energy of Gibbs, enthalpy, and entropy, at 40°C, was 81.47, 16.85, and ?0.21?kJ/mol?·?K, respectively. After total digestion, 123.95% of the original activity was retained. Results suggested that tannase from A. tamarii URM 7115 is an enzyme of interest for industrial applications, such as gallic acid production, additive for feed industry, and for beverage manufacturing, due to its catalytic and thermodynamic properties. 相似文献