基于LSMM与MSPA的深圳市绿色景观连通性研究

基于线性光谱混合模型(LSMM,Linear Spectral Mixture Model),引入形态学空间格局分析(MSPA,Morphological Spatial Pattern Analysis)进行城市地域绿色景观连通性评价。根据城市绿色景观特点和MSPA方法中的7种连通性类型的涵义,定义了城市绿色景观连通性功能类型。以深圳市1986年、1995年、2000年、2005年及2010年五期Landsat TM影像为数据源,应用线性光谱混合模型提取植被覆盖率,得到深圳市植被覆盖图。在此基础上,提取出高、全植被覆盖作为目标像元进行MSPA处理,分析植被覆盖状况与绿色景观功能类型的时序总体特征及空间梯度动态。结果表明:深圳市绿色景观破碎程度较高,表现为对结构连通性贡献最小的斑块类型总数最大。城市内部东西部连通性呈现出不同变化的趋势;右侧外圈层的大鹏半岛结构连通性最佳;在同一城市化发展梯度上,东部的样带连通性水平比西部要好。在城市化过程中,深圳市高、全覆被植被像元连通性大小受以下因素的影响:城市化程度,地形因素及区域定位。在同一城市化程度上,地形因素对景观连通性的影响较大。从整体的时间变化和空间梯度动态分析可知,在快速城市化过程中植被覆盖率和连通性功能均下降,而到稳定城市化阶段植被覆盖率和连通性均得到改善。研究表明线性光谱混合模型与形态学空间格局分析相结合可以较好的表征城市绿色景观连通性类型时空分布特征,进而明晰城市化过程与区域内绿色景观数量及连通性动态变化关系。     

Cardiac mitochondrial ATP-sensitive potassium channel is activated by nitric oxide in vitro

Previous observations on the activation of the mitochondrial ATP-sensitive potassium channel (mitoK(ATP)) by nitric oxide (NO) in myocardial preconditioning were based on indirect evidence. In this study, we have investigated the direct effect of NO on the rat cardiac mitoK(ATP) after reconstitution of the inner mitochondrial membranes into lipid bilayers. We found that the mitoK(ATP) was activated by exogenous NO donor S-nitroso-N-acetyl penicillamine or PAPA NONOate. This activation was inhibited by mitoK(ATP) blockers 5-hydroxydecanoate or glibenclamide. Our observations confirm that NO can directly activate the cardiac mitoK(ATP), which may underlie its contribution to myocardial preconditioning.     

混凝复配剂的制备及其污水处理效果

采用静态实验遴选不同种硅藻土,进而研究其与常用混凝剂的最佳组合及复配比,考察其中几种复配剂在一定条件对城市污水的处理效果。实验结果表明:硅藻土和混凝剂组成的复配剂具有强化混凝作用;氯化铝、硫酸亚铁和高分子絮凝剂与硅藻土分别在1:9,1:11,和1:9的配比时制备复配剂处理生活污水的效果最佳。     

A robust two-gene signature for glioblastoma survival prediction

Glioblastoma multiforme (GBM) is a highly malignant brain tumor. We explored the prognostic gene signature in 443 GBM samples by systematic bioinformatics analysis, using GSE16011 with microarray expression and corresponding clinical data from Gene Expression Omnibus as the training set. Meanwhile, patients from The Chinese Glioma Genome Atlas database (CGGA) were used as the test set and The Cancer Genome Atlas database (TCGA) as the validation set. Through Cox regression analysis, Kaplan-Meier analysis, t-distributed Stochastic Neighbor Embedding algorithm, clustering, and receiver operating characteristic analysis, a two-gene signature (GRIA2 and RYR3) associated with survival was selected in the GSE16011 dataset. The GRIA2-RYR3 signature divided patients into two risk groups with significantly different survival in the GSE16011 dataset (median: 0.72, 95% confidence interval [CI]: 0.64-0.98, vs median: 0.98, 95% CI: 0.65-1.61 years, logrank test P < .001), the CGGA dataset (median: 0.84, 95% CI: 0.70-1.18, vs median: 1.21, 95% CI: 0.95-2.94 years, logrank test P = .0017), and the TCGA dataset (median: 1.03, 95% CI: 0.86-1.24, vs median: 1.23, 95% CI: 1.04-1.85 years, logrank test P = .0064), validating the predictive value of the signature. And the survival predictive potency of the signature was independent from clinicopathological prognostic features in multivariable Cox analysis. We found that after transfection of U87 cells with small interfering RNA, GRIA2 and RYR3 influenced the biological behaviors of proliferation, migration, and invasion of glioblastoma cells. In conclusion, the two-gene signature was a robust prognostic model to predict GBM survival.     

Host cellular signaling induced by influenza virus

A wide range of host cellular signal transduction pathways can be stimulated by influenza virus infection. Some of these signal transduction pathways induce the host cell’s innate immune response against influenza virus, while others are essential for efficient influenza virus replication. This review examines the cellular signaling induced by influenza virus infection in host cells, including host pattern recognition receptor (PRR)-related signaling, protein kinase C (PKC), Raf/MEK/ERK and phosphatidylinositol- 3-kinase (PI3K)/Akt signaling, and the corresponding effects on the host cell and/or virus, such as recognition of virus by the host cell, viral absorption and entry, viral ribonucleoprotein (vRNP) export, translation control of cellular and viral proteins, and virus-induced cell apoptosis. Research into influenza virus-induced cell signaling promotes a clearer understanding of influenza virus-host interactions and assists in the identification of novel antiviral targets and antiviral strategies.     

英国等地不明原因儿童肝炎的暴发情况及病因

2022年3月31日,苏格兰首先报告了5例患有不明原因重症肝炎的儿童。世界卫生组织（World Health Organization,WHO）于4月15日就不明原因儿童肝炎发布指导性意见,对确诊病例、可疑病例和流行病学相关病例进行了定义。截至4月21日,已有12个国家报告169例确诊病例,从1月龄至16岁不等。临床表现为急性肝炎,谷草转氨酶（aspartate aminotransferase,AST）或谷丙转氨酶（alanine aminotransferase,ALT）>500IU/L,多数患儿有黄疸、恶心、腹痛、乏力、嗜睡和胃肠道症状,包括腹泻和呕吐,大多数患儿无发热。17例接受了肝移植,至少报告1例死亡。考虑到流行病学特点和患儿的临床特征,感染性因素导致该疾病的可能性更大。病例的实验室检查结果均排除了甲、乙、丙、丁和戊型肝炎,并提示腺病毒可能与不明原因儿童肝炎有关,但其他感染性因素或环境因素仍不能完全排除。本文对此次不明原因儿童肝炎的发展情况及其可能病因进行了介绍。该疾病存在输入性风险,我国应对此早做准备。     

Molecular insights into the antifungal mechanism of bacilysin

Bacilysin is one of the simplest antimicrobial peptides and has drawn great attention for its excellent performance against Candida albicans. In this study, the antifungal mechanism of bacilysin was investigated. The target enzyme glucosamine-6-phosphate synthase (GFA) was expressed heterologously in Escherichia coli and its inhibition by bacilysin and derivatives was studied. It was concluded that bacilysin could be hydrolyzed by a proteinase of C. albicans, and that the released product, anticapsin, then inhibited the aminotransferase activity of GFA. This result was verified by molecular simulation, and the interaction mode of anticapsin with GFA was detailed, which provides data for the development of novel antifungal drugs. Transport of bacilysin into fungal cells was also simulated and it was shown that bacilysin is more readily transported into cells than anticapsin. Thus, our findings support a mechanism whereby bacilysin is transported into fungal pathogens, hydrolyzed to anticapsin, which then inhibits GFA.