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A hydroxyl radical generating system consisting of 0.1 mmol/L FeCl3, 0.1 mmol/L ascorbic acid, and various H2O2 concentrations (0, 0.25, 0.5, 1.0, 2.5, 5, 10 and 25 mmol/L) was established and used to investigate the interaction mechanism of differently oxidized myofibrillar proteins (MPs) with 3-methyl butanal, pentanal, hexanal and heptanal. First, the binding capacity of oxidized MPs to the four aldehydes were determined by gas chromatography-mass spectrometry (GC-MS). Then, ultraviolet (UV) absorption spectroscopy, fluorescence spectroscopy (quenching mechanism and thermodynamic analysis) and circular dichroism (CD) spectroscopy were used to reveal the interaction mechanism between oxidized MPs and aldehydes. The results showed that heptanal had the strongest binding capacity with MPs, and the binding capacity of oxidized MPs with a H2O2 concentration of 1.0 mmol/L to all four aldehydes was the highest (P < 0.05). UV absorption spectra and fluorescence spectra demonstrated that oxidized MPs interacted with the four aldehydes via static and dynamic quenching. The maximum absorption peaks of both tyrosine and tryptophan residues were red-shifted with an increase in heptanal concentration, indicating that the tyrosine and tryptophan residues of MPs were exposed to a more hydrophilic environment. Thermodynamic analysis showed that the interaction between MPs and heptanal was mainly driven by hydrophobic interaction. The CD spectra showed that the α-helix content decreased from 19.24% to 16.88% (P < 0.05) and the β-sheet content increased from 24.59% to 26.47% (P < 0.05) with increasing heptanal concentration, and the structure of MPs changed from the ordered to the disordered state. This study provides a theoretical basis for flavor regulation of meat products.

This paper builds a time series prediction model of recurrent neural networks based on time series electricity load forecasting. In this paper, the household electricity consumption record data of some residents in urban area S is taken as the research object, and the laws and characteristics of users’ electricity consumption behavior are analyzed in depth based on the real residential electricity consumption data. External factors such as temperature conditions, holidays, etc. The arithmetic cases are also analyzed using real load data sets. In the short-term continuous electricity data analysis, the smaller the time interval is, the closer its corresponding electricity consumption ratio is to 1. There is a negative correlation between long-term continuous electricity consumption. When the temperature is 30~35oC versus -5~0oC, electricity consumption rises significantly. Comparing and analyzing the time series decomposition-RNN with several models, the time series decomposition-RNN model has the highest fit at 10:00-12:00 and 12:00-14:00, and the result verifies the validity of the model proposed in this paper.

Protein aggregation is associated with various diseases caused by protein misfolding. Among them, amylin deposition is a prominent feature of type 2 diabetes. At present, the mechanism of amylin aggregation remains unclear, and this has hindered the treatment of type 2 diabetes. In this study, we analyzed the aggregation process of amylin using the quantum dot (QD) imaging method. QD fluorescence imaging revealed that in the presence of 100 μM amylin, aggregates appeared after 12 h of incubation, while a large number of aggregates formed after 24 h of incubation, with a standard deviation (SD) value of 5.435. In contrast, 50 μM amylin did not induce the formation of aggregates after 12 h of incubation, although a large number of aggregates were observed after 24 h of incubation, with an SD value of 2.883. Confocal laser microscopy observations revealed that these aggregates were deposited in three dimensions. Transmission electron microscopy revealed that amylin existed as misfolded fibrils in vitro and that QDs were uniformly bound to the amylin fibrils. In addition, using a microliter-scale high-throughput screening (MSHTS) system, we found that rosmarinic acid, a polyphenol, inhibited amylin aggregation at a half-maximal effective concentration of 852.8 μM. These results demonstrate that the MSHTS system is a powerful tool for evaluating the inhibitory activity of amylin aggregation. Our findings will contribute to the understanding of the pathogenesis of amylin-related diseases and the discovery of compounds that may be useful in the treatment and prevention of these diseases. [ABSTRACT FROM AUTHOR]

Reforming instruction is challenging. In this comparative case study of 12 school districts, we investigated the dilemmas that emerged for system leaders as they engaged in system building for elementary science and the approaches leaders took in managing them. We found that system leaders' efforts to manage their environments contributed to the preferential treatment of literacy and mathematics relative to science. Leaders managed this dilemma using three strategies: (a) integration of science with other subjects, (b) specialization of teachers, and (c) adopting curriculum materials. This study contributes to literature on dilemma management by showing that dilemmas in education system building are school-subject sensitive, emerge in relation to system building for other subjects, and are embedded in school and education systems' structural/organizational arrangements. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The stereochemical synthesis of highly substituted Danishefsky‐type dienes remains unsolved in organic chemistry. We describe a simple and efficient approach for the stereoselective synthesis of Danishefsky‐type trisubstituted dienes from readily available propargylic esters via Pd‐catalyzed dienylation reaction through the key intermediate metallacyclobutene in a regio‐, chemo‐ and stereoselective fashion. This method facilitates a broad range of challenging trisubstituted dienes with a high level of stereocontrol. The synthetic utilities of oxygenated trisubstituted dienes have been demonstrated by the downstream chemistry, which notably undergoes Diels‐Alder reaction with a variety of electron‐deficient dienophiles to furnish multisubstituted cyclohexenes in good yields with excellent stereoselectivity. [ABSTRACT FROM AUTHOR]

Ciprofol is a novel short-acting intravenous anaesthetic developed in China that is mainly metabolized by cytochrome P450 2B6 (CYP2B6) and uridine diphosphate glucuronosyltransferase 1A9 (UGT1A9). Currently, insufficient evidence is available to support drug‒drug interactions between ciprofol and CYP2B6 inactivators. Here, we established a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method to assess the concentration of ciprofol and investigated the effects of psoralen and clopidogrel on the metabolism of ciprofol in liver microsomes and rats. In rat and human liver microsomes, the median inhibitory concentration (IC50) values of psoralen were 63.31 μmol·L-1 and 34.05 μmol·L-1, respectively, showing mild inhibitory effects on ciprofol metabolism, whereas the IC50 values of clopidogrel were 6.380 μmol·L-1 and 2.565 μmol·L-1, respectively, with moderate inhibitory effects. SD rats were randomly divided into three groups: psoralen (27 mg·kg-1), clopidogrel (7.5 mg·kg-1), and the same volume of 0.5% carboxy methyl cellulose. After 7 days, all rats were injected with 2.4 mg·kg-1 ciprofol. Compared with the control group, the AUC and MRT values of ciprofol in the psoralen and clopidogrel groups were significantly greater, whereas the CL values were significantly lower. In addition, the durations of loss of righting reflex (LORR) in the psoralen and clopidogrel groups were 16.1% and 23.0% longer than that in the control group, respectively. In conclusion, psoralen and clopidogrel inhibit ciprofol metabolism to different degrees and prolong the duration of LORR in rats. [ABSTRACT FROM AUTHOR]

Counter-gravity casting (CGC) aims to eliminate turbulent melt flow and defect formation during filling and subsequent solidification by pushing high-temperature melt into the mold cavity against gravity with regulated pressure. However, limited by the opaqueness of molten metals and the complexity of the CGC apparatus, it is extremely difficult to directly quantify the high-velocity mold filling and pressurized solidification in real-time. Here, we report the design and characterization of a CGC system capable of in situ monitoring of mold filling and subsequent solidification processes in the synchrotron beamlines by deploying a high-energy, high-speed synchrotron x-ray imaging technique. The high-velocity melt flow and dendrite growth during pressurized solidification have been quantified for systematical process parameter analysis by investigating time-resolved x-ray images of an exemplary Al–Cu alloy. The high-speed imaging results demonstrate that the in situ CGC system provides a useful way to better understand the fundamentals of mold filling, pressurized solidification, and experimental inputs for high-fidelity modeling in scientific and industrial applications. [ABSTRACT FROM AUTHOR]