129 research outputs found
Modelling compressive behaviour of cement paste with superabsorbent polymer
No full textSuperabsorbent polymer (SAP) can modify the microstructure and influence the mechanical properties of cement paste in at least two ways: while cavities left by SAP increase the total porosity, water released by SAP affects the hydration degree of the surrounding paste. As a starting point for investigation into the overall effect, this study presents a numerical model comprised of spherical voids, affected zones, and the unaffected matrix. In comparison, a binary model consisting only of the voids and the unaffected matrix is built up. Compressive loads are applied to both paste models. The results show that in either model a considerable negative normal stress (compressive) is typical in the middle part of SAP pore walls. The void-surrounding area subject to positive normal stress seems to be larger in the SAP-containing paste than in the other one. Nevertheless, there is a 10% reduction in maximum principal stress caused by the tougher affected zone
Berberine and palmatine, acting as allosteric potential ligands of α7 nAChR, synergistically regulate inflammation and phagocytosis of microglial cells
No full textBerberine and palmatine are isoquinoline quaternary alkaloids derived from Chinese medicinal herbs. These alkaloids have shown promising synergy in inhibiting acetylcholinesterase (AChE), indicating their potential in treating Alzheimer's disease (AD). Besides, the anti-inflammatory effects of berberine and palmatine have been widely reported, although the underlying mechanism remains unclear. Here, we found that berberine and palmatine could induce calcium ion (Ca2+) influx via activating α7 nicotinic acetylcholine receptor (α7 nAChR) in cultured microglial cells, possibly serving as its allosteric potential ligands. Furthermore, we examined the synergistic anti-inflammatory effects of berberine and palmatine in the LPS-induced microglia, that significantly suppressed the production of TNF-α and iNOS. Notably, this suppression was reversed by co-treatment with a selective antagonist of α7 nAChR. Moreover, the alkaloid-induced microglial phagocytosis was shown to be mediated by the induction of Ca2+ influx through α7 nAChR and subsequent CaMKII-Rac1-dependent pathway. Additionally, the combination of berberine and palmatine, at low concentration, protected against the LPS-induced endoplasmic reticulum stress and mitochondrial dysfunction in microglia. These findings indicate the potential of berberine and palmatine, either individually or in combination, in contributing to anti-AD drug development, which provide valuable insights into the mechanisms by which natural products, such as plant alkaloids, exert their anti-AD effects.</p
The Effects of Baclofen for the Treatment of Gastroesophageal Reflux Disease: A Meta-Analysis of Randomized Controlled Trials
No full textObjectives. Baclofen can relieve gastroesophageal reflux-related symptoms in healthy subjects and gastroesophageal reflux disease (GERD) patients by reducing the incidence of transient lower esophageal sphincter relaxation. This meta-analysis aimed to evaluate the efficacy and safety of baclofen for the treatment of GERD. Methods. We systematically searched randomized controlled trials published prior to November 2013 from PubMed, Medline, Embase, ScienceDirect, ClinicalTrials.gov, and the Cochrane Central Register of Randomized Controlled Trials. We performed a meta-analysis of all eligible trials. Results. Nine studies were identified with a total of 283 GERD patients and healthy subjects. Comparative analysis provided high quality data supporting the ability of baclofen to promote a short-term decrease in the number of reflux episodes per patient, the average length of reflux episodes, and the incidence of transient lower esophageal sphincter relaxation. No serious adverse events or death events were reported, and there were no significant differences in the overall adverse events between baclofen and placebo. All reported side effects of baclofen were of mild-to-moderate intensity, and the drug was well tolerated. Conclusion. Abundant evidence suggests that baclofen may be a useful approach for the treatment of GERD patients; however, a larger well-designed research study would further confirm this recommendation
ChemInform Abstract: Phase Transfer Catalytic Synthesis of Phenylacetyl Arylthioureas under Microwave Irradiation Conditions.
No full textChemInform Abstract: Synthesis of Benzoyl‐N‐phenylthioureas under Microwave Irradiation and Phase Transfer Catalysis Conditions.
No full textstudy of enhanced thermal conductivity in ordered AlGaO3 alloys
No full textThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 115, 242103 (2019) and may be found at https://aip.scitation.org/doi/10.1063/1.5131755.We compute the lattice thermal conductivity of monoclinic β-Ga2O3 and the ordered AlGaO3 alloy from the phonon Boltzmann transport equation, with the harmonic and third-order anharmonic force constants calculated from density functional theory. The calculated thermal conductivity of β-Ga2O3 is consistent with experiment. We demonstrate that the lowest-energy structure of an Al0.5Ga0.5 alloy, which is ordered, has a thermal conductivity that is raised by more than 70% compared to β-Ga2O3. We attribute the enhancement to (1) increased group velocities and (2) reduced anharmonic scattering rates due to the reduced weighted phase space. The findings offer an avenue toward improved heat dissipation from Ga2O3 devices.
The authors acknowledge Shengying Yue, Jingjing Shi, Samuel Graham, and Yuewei Zhang for fruitful discussions. This work was supported by the GAME MURI of the Air Force Office of Scientific Research (No. FA9550-18-1-0479). Computing resources were provided by the Center for Scientific Computing supported by the California NanoSystems Institute and the Materials Research Science and Engineering Center (MRSEC) at UC Santa Barbara through the National Science Foundation (NSF) (Nos. DMR-1720256 and CNS-1725797) and by the Extreme Science and Engineering Discovery Environment (XSEDE), which was supported by NSF Grant No. ACI-1548562
ERCC1 rs11615 polymorphism and chemosensitivity to platinum drugs in patients with ovarian cancer: a systematic review and meta-analysis
No full textAbstract Objective To explore the relationship between ERCC1 rs11615 polymorphism and chemosensitivity to platinum drugs in ovarian cancer by the method of meta-analysis. Methods Pubmed, Web of Science, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), and China Wanfang databases were comprehensively searched up to September 2020, to identify the relationship between ERCC1 rs11615 polymorphism and chemosensitivity of ovarian cancer. The data was analyzed by Stata 15.0 statistic software. Results A total of 10 published papers were included, including 1866 patients with ovarian cancer. The results showed that compared allele C at ERCC1 rs11615 locus with allele T, the pooled OR was 0.92 (95%CI:0.68 ~ 1.24, P > 0.05). There were no significant differences in recessive, dominant, homozygous, and heterozygous models. In accordance with a subgroup analysis of Ethnicity, all genotypes were statistically significant in the Asian population. In the allelic, dominant, recessive, homozygous and heterozygous models, the OR was 0.70 (95%CI:0.51 ~ 0.95), 0.20 (95%CI:0.07 ~ 0.56), 0.79 (95%CI:0.63 ~ 1.00), 0.21 (95%CI:0.07 ~ 0.59), 0.19 (95%CI:0.07 ~ 0.54), respectively, while in the Caucasian population, no statistically significant genotype was found. Conclusion The ERCC1 rs11615 polymorphism is associated with chemosensitivity in patients with ovarian cancer, especially in the Asian population, but not in the Caucasian population
Genetic polymorphism analysis of cytochrome P4502E1 (CYP2E1) in Chinese Han populations from four different geographic areas of Mainland China
No full textAbstractCYP2E1 is one of a superfamily of enzymes that play a central role in activating and detoxifying many xenobiotics and endogenous compounds thought to be involved in the development of several human diseases. Among other factors, individual susceptibility to developing these pathologies relies on genetic polymorphisms, which are related to ethnic differences, since the frequency of mutant genotypes varies in different populations. The aim of this study was to investigate the genetic basis of CYP2E1 polymorphisms in the populations of four different geographical locations of China. Twenty-two different CYP2E1 polymorphisms, including six novel variants in promoter regions and a novel nonsense mutation, were identified. The frequencies of some polymorphisms and genotypes demonstrated significant differences among the four populations. Linkage disequilibrium analysis and tag SNP selection were performed. Haplotypes were analyzed within the selected tag SNPs. Tag SNP selection and haplotype distributions showed differences across the four populations
1,25(OH) 2 D 3 induces regulatory T cell differentiation by influencing the VDR/PLC-γ1/TGF-β1/pathway
No full text- …
