Molecular dynamics simulations of the self-organization of side-chain decorated polyaromatic conjugation molecules: phase separated lamellar and columnar structures and dispersion behaviors in toluene solvent

The self-organization of five model side-chain decorated polyaromatic asphaltene molecules with or without toluene solvent was investigated by means of atomistic molecular dynamic (MD) simulations. It was found that the organizational structure of polycyclic asphaltene molecules is significantly affected by the position and length of side chains. In the present study, two types of phase-separated stacking configurations, including the phase separated lamellar structure (PSLS) and the phase separated columnar structure (PSCS), were found. The PSLS and PSCS were also maintained in the presence of a small amount of toluene additive (30% wt fraction). When adding excess toluene molecules, the asphaltene molecules formed highly dispersed nanoaggregates. The dynamic properties of the π–π stacking structures in the PSLS and PSCS, as well as the nanoaggregates, were probed. It was found that the number and size of alkyl side chains significantly impacted the size and number of π–π stacking structures in the aggregates. Through tracking the structural evolution of the nanoaggregates, a possible dissociation mechanism of nanoaggregates is also suggested.

The self-organization of five model side-chain decorated polyaromatic asphaltene molecules with or without toluene solvent was investigated by means of molecular dynamic (MD) simulations.     

Silicone rubber membrane with specific pore size enhances wound regeneration

A porous structure is critically important for wound dressing or tissue engineering scaffolds. However, the influence of the pore sizes on cell proliferation, tissue regeneration and the underlying mechanism remains unclear. In this study, silicone rubber membranes with different pore sizes were prepared using certain constituents of liquid silicone rubber precursor/liquid paraffin/hexane based on our previous studies. It was found that pore size had a significant impact on cell proliferation and wound healing. The CCK8 analysis revealed that the membrane with a certain pore size (110.47 μm, middle pore membrane, MPM) was suitable for cell proliferation compared with the membranes with other pore sizes (218.03 μm, large pore membrane, LPM; 5.27 μm, small pore membrane, SPM; non‐porous membrane, NPM). Further studies demonstrated that the MPM promoted cell proliferation via activating the Wnt/β‐catenin signalling pathway. More importantly, wound healing experiments showed that 7 days post‐wounding, the rate of wound healing was 89.25% with the MPM, which was significantly higher than with LPM, SPM or NPM. The in vivo data indicated that wound healing was accelerated by treatment with a silicone rubber membrane with a pore size of 110.47 μm. Our results strongly suggest that different pore structures might affect cell proliferation and wound healing and that a silicone rubber membrane with a specific pore size could potentially be used as a promising wound dressing. Copyright © 2017 John Wiley & Sons, Ltd.     

ZIF-8 derived Ag-doped ZnO photocatalyst with enhanced photocatalytic activity

Recently, zeolitic imidazolate framework-8 (ZIF-8) has been widely studied and used as a catalyst in various fields, due to its high specific surface area, tunable channels and thermal and chemical stability. In this paper, ZIF-8 was used as a precursor to fabricate a Ag/ZnO photocatalyst, and the influence of Ag on the photocatalytic activity of ZnO has been explored. All samples were characterised using XRD, SEM, TEM, and UV-vis diffuse reflectance spectra. The photocatalytic activity of all samples was evaluated by the degradation of a rhodamine B solution under UV light. The results show that ZIF-8 was completely transformed into ZnO when it was calcined at 550 °C for 6 h, and Ag was well loaded onto ZnO. The photocatalytic efficiency of ZnO is 92.32%. When ZnO was doped with Ag, its photocatalytic efficiency was highly improved (99.64%). Furthermore, Ag/ZnO exhibited high photocatalytic stability. After five repeated cycles, the photocatalytic activity of Ag/ZnO was highly retained at 97.48%.

In this paper, ZIF-8 was used as a precursor to fabricate a Ag/ZnO photocatalyst, and the influence of Ag on the photocatalytic activity of ZnO has also been explored.     

Robotic-assisted vs. laparoscopic and abdominal myomectomy for treatment of uterine fibroids: a meta-analysis

Uterine fibroids are extremely common uterine neoplasms. However, whether robotic-assisted laparoscopic myomectomy (RALM) is superior to laparoscopic myomectomy (LM) or abdominal myomectomy (AM) is still debatable. Consequently, we aimed to compare the three currently major surgical techniques used in patients with uterine fibroids. We searched the PubMed, the Cochrane Library, MEDLINE, Embase, and Web of Science databases up to April 22, 2017. The meta-analysis included 20 studies involving 2852 patients. The number of complications [odd ratio (OR) 0.52, p?=?0.009], estimated blood loss (EBL) [weighted mean difference (WMD) ?33.03, p?=?0.02], conversions (OR 0.34, p?=?0.03), and postoperative bleeding (OR 0.18, p?=?0.03) in RALM cases was significantly less than that for LM. The numbers of complications (OR 0.56, p?=?0.03), length of hospital stay (WMD ?1.74, p?p?p?p?相似文献   

Correction: Ultra-wideband manipulation of electromagnetic waves by bilayer scattering engineered gradient metasurface

Correction for ‘Ultra-wideband manipulation of electromagnetic waves by bilayer scattering engineered gradient metasurface’ by Yinghui Guo et al., RSC Adv., 2018, 8, 13061–13066.

The journal citations in ref. 10 and 11 were incorrect in the published article. The corrected references are shown below as ref. 1 and 2, respectively.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

云南省2010－2013年男男性行为人群艾滋病相关危险因素变化趋势分析

目的 了解云南省MSM人群知晓率、行为等艾滋病相关危险因素的变化趋势及其安全套使用的影响因素,为干预策略制定和效果评价提供依据。方法 2010-2013年在云南省连续开展MSM哨点监测,调查该人群一般人口学特征、艾滋病相关知识、性行为及安全套使用、吸毒行为、干预措施覆盖等情况,进行趋势和影响因素分析。结果 共调查9 073人,艾滋病知识知晓率、与同性发生性行为比例及安全套使用率均呈逐年上升趋势(P<0.01),与异性发生性行为时安全套使用率明显低于同性,吸毒比例和患性病比例呈下降趋势(P<0.01).同居、低知晓率、外省/外籍、居住时间不足一年、文化程度低、未接受过干预、肛交次数多、未曾做过HIV抗体检测等因素为影响MSM坚持使用安全套的危险因素。结论 云南省近4年MSM艾滋病综合干预效果初显,但多项指标仍处于较低水平,仍需重点关注同居、文化程度低、流动性较大、肛交次数多、有异性性行为的MSM干预,扩大干预覆盖面,继续强化落实HIV动员检测、安全套推广使用等核心干预措施。     

间质金属蛋白酶基因多态性与中心性肥胖在非酒精性脂肪肝病中交互作用研究

目的 探讨间质金属蛋白酶-9(MMP-9)-1562C/T(rs3918242)以及MMP-2-1306C/T(rs243865)位点单核苷酸多态性(SNP)与非酒精性脂肪肝(NAFLD)遗传易感性以及与中心性肥胖交互作用。方法 对545例NAFLD患者和636例正常对照,采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)分析rs24386以及rs3918242基因型、非条件logistic分析各基因型与脂肪肝发病易感性关系,利用非条件logistic分析和广义多因子降维(GMDR)法分析rs3918242、rs243865与中心性肥胖的交互作用。结果 MMP-9 rs3918242位点T基因携带者(TT/CT)与非T基因携带者(CC)的NAFLD罹患风险明显增加(OR=1.67,95%CI:1.32～2.12,P=0.001;调整OR=1.65,95%CI:1.31～2.01,P=0.008);而MMP-2 rs243865位点T基因携带者(TT/CT)与非T基因携带者(CC)的NAFLD罹患风险明显降低(OR=0.68,95%CI:0.53～0.86,P=0.001;调整OR=0.66,95%CI:0.49～0.90,P=0.007)。广义多因子降维法分析结果显示,rs3918242与中心性肥胖在NAFLD发病中存在交互作用(P=0.001)。利用非条件logistic校正年龄、性别、腰围、BMI、LDL-C、HDL-C、FPG、胰岛素抵抗指数后,分析显示,携带rs3918242 TT/CT基因型中心性肥胖个体罹患NAFLD的风险高于携带CC基因非吸烟个体(OR=4.50,95%CI:2.78～7.17,P=0.007)。结论 MMP-9基因的rs3918242以及MMP-2基因的rs243865与NAFLD患病罹患风险紧密相关,rs3918242与中心性肥胖在NAFLD发病中具有协同效应。     

Fast removal of Co(ii) from aqueous solution using porous carboxymethyl chitosan beads and its adsorption mechanism

Porous carboxymethyl chitosan (PCMC) beads were synthesized via ionic coacervation/chemical crosslinking, using polyethylene glycol (PEG) as a porogen and calcium chloride and glutaraldehyde as physical and chemical cross-linkers. The as-synthesized PCMC beads were characterized using SEM, EDS, BET, TGA, FTIR and XPS analysis and then tested for the removal of Co(ii) from aqueous solution. The effects of the initial pH, Co(ii) concentration and temperature were investigated. It was found that the adsorption equilibrium is reached within 6 h and the maximum adsorption capacity is 46.25 mg g⁻¹. In addition, the kinetics and equilibrium data are well described by pseudo-second-order kinetics and the Langmuir isotherm model. Moreover, the desorption and re-adsorption performance was also studied, and the results revealed that the prepared new adsorbent still showed good adsorption performance after five cycles of regeneration. Finally, the adsorption mechanism, including chemical and physical adsorption, was proposed on the basis of the microstructure analysis, adsorption kinetics and isotherm results, and chemical adsorption was found to be the main adsorption mechanism during the process of the removal of Co(ii).

The as-prepared adsorbent exhibits excellent adsorption capacity and fast kinetics for Co(ii).     

PLNseq: a multivariate Poisson lognormal distribution for high‐throughput matched RNA‐sequencing read count data

High‐throughput RNA‐sequencing (RNA‐seq) technology provides an attractive platform for gene expression analysis. In many experimental settings, RNA‐seq read counts are measured from matched samples or taken from the same subject under multiple treatment conditions. The induced correlation therefore should be evaluated and taken into account in deriving tests of differential expression. We proposed a novel method ‘PLNseq’, which uses a multivariate Poisson lognormal distribution to model matched read count data. The correlation is directly modeled through Gaussian random effects, and inferences are made by likelihood methods. A three‐stage numerical algorithm is developed to estimate unknown parameters and conduct differential expression analysis. Results using simulated data demonstrate that our method performs reasonably well in terms of parameter estimation, DE analysis power, and robustness. PLNseq also has better control of FDRs than the benchmarks edgeR and DESeq2 in the situations where the correlation is different across the genes but can still be accurately estimated. Furthermore, direct evaluation of correlation through PLNseq enables us to develop a new and more powerful test for DE analysis. Application to a lung cancer study is provided to illustrate the practical utilities of our method. An R package implementing the method is also publicly available. Copyright © 2015 John Wiley & Sons, Ltd.