Intraspecific differences of Asian/Australian Phragmites australis subgroups reveal no potentially invasive traits

Hydrobiologia - Phragmites australis is a cosmopolitan plant species with high intraspecific diversity and phenotypic plasticity. Due to its variability and large ecological niche breadth,...     

一株牛源阿卡斑病毒的分离鉴定

阿卡斑病毒(Akabane virus,AKV)是能引起牛、绵羊、山羊流产、早产、新生胎儿畸形的虫媒性RNA病毒。为了解家畜虫媒病毒在我国西南边境地区的分布和流行情况,本研究对中缅边境西盟县的52份牛抗凝血和140份血清(牛70份、羊70份)中的蓝舌病病毒(Bluetongue virus,BTV)、鹿流行性出血热病毒(Epizootic hemorrhagic disease virus,EHDV)、AKV等虫媒病毒进行检测与分离,通过ELISA及qRT-PCR方法检测病毒,通过核酸阳性抗凝血接种BHK细胞传代以分离病毒,通过设计特异性引物,扩增分离毒株S基因721bp片段及M基因816bp片段,通过克隆测序及中和试验以鉴定病毒,最终从38号牛的抗凝血中分离到一株AKV,TCID50为10-3.5/0.1mL,经比对,分离株S片段与日本KS-2/Mo/06毒株亲缘关系最近,核苷酸同源性为97.66%,M片段与中国DHL10M110毒株亲缘关系最近,核苷酸同源性为96.56%。本研究首次报告了从云南边境地区牛群中分离到AKV,证实了西南边境存在AKV的流行,为AKV在我国的流行病学和边境地区疫病风险防控提供了重要参考及有力依据。     

基于雪岭云杉树轮宽度重建过去339年天山中部巴音布鲁克地区夏季NDVI

归一化差异植被指数(NDVI)被广泛应用于植被研究的各个领域,但由于观测时长较短,难以满足长时间尺度的研究需要。基于巴音布鲁克地区雪岭云杉建立了树轮宽度年表(STD),计算年表和NDVI同气象观测数据的相关系数。结果表明:树轮宽度指数和NDVI均与同时段的气象数据具有显著相关。结合宽度年表与6—8月NDVI间的显著正相关(r=0.7,P＜0.01,n=38),使用回归模型重建了研究区过去339年的夏季(6—8月)NDVI变化序列,在1680—2018年,重建序列有4个高植被覆盖时段(1738—1765、1786—1798、1964—1973和2000—2018年)和5个低植被覆盖时段(1690—1714、1825—1834、1850—1880、1895—1920和1945—1955年)。重建结果也反映了天山中部水文气候。与周边重建的对比显示,当开都河径流量增加,且研究区处于较为潮湿的环境时,植被覆盖相对较高,反之植被覆盖偏低。重建序列的极值也捕捉了历史文献中一系列自然灾害。混合单粒子拉格朗日综合轨迹模型(HYSPLT)后向轨迹模型和风场分析表明,NDVI异常受到西风带来的降水影响。     

阿尔茨海默病的症状、诊断及其护理

阿尔茨海默病(Alzheimer's disease,AD),俗称老年痴呆病,是一种发病进程缓慢、随着时间不断恶化的神经退化性疾病.本研究根据认知能力和身体机能的恶化程度对阿尔茨海默病的病程进行分期描述,对前期、早期、中期和晚期4个时期的症状、临床诊断和护理进行了系统的分析,以期全面了解和认识阿尔茨海默病的症状和征候,为预防和早期干预阿尔茨海默病提供理论基础.     

scGET: Predicting Cell Fate Transition During Early Embryonic Development by Single-cell Graph Entropy

During early embryonic development, cell fate commitment represents a critical transition or"tipping point"of embryonic differentiation, at which there is a drastic and qualitative shift of the cell populations. In this study, we presented a computational approach, scGET, to explore the gene–gene associations based on single-cell RNA sequencing (scRNA-seq) data for critical transition prediction. Specifically, by transforming the gene expression data to the local network entropy, the single-cell graph entropy (SGE) value quantitatively characterizes the stability and criticality of gene regu-latory networks among cell populations and thus can be employed to detect the critical signal of cell fate or lineage commitment at the single-cell level. Being applied to five scRNA-seq datasets of embryonic differentiation, scGET accurately predicts all the impending cell fate transitions. After identifying the"dark genes"that are non-differentially expressed genes but sensitive to the SGE value, the underlying signaling mechanisms were revealed, suggesting that the synergy of dark genes and their downstream targets may play a key role in various cell development processes. The application in all five datasets demonstrates the effectiveness of scGET in analyzing scRNA-seq data from a network perspective and its potential to track the dynamics of cell differentiation. The source code of scGET is accessible at https://github.com/zhongjiayuna/scGET_Project.     

用于白蚁防治的联苯菊酯微胶囊的制备及性能研究

针对白蚁防治药剂联苯菊酯传统加工剂型存在的安全性差、持效期短等缺点,采用溶剂蒸发法制备联苯菊酯微胶囊.通过粒径大小、外观形貌、包封率以及载药量筛选出最佳芯壁比、乳化剂用量和剪切时间,并对微胶囊理化特性及释放性能进行表征,同时考察微胶囊对白蚁的杀灭效果和持效性.研究结果表明,芯壁比为1:1.5,乳化剂用量为7％,剪切时间为6 min时制备的联苯菊酯微胶囊粒径适中(97.6μm),包封率高达70.5％,缓释性能良好,与市售乳油相比,对白蚁的杀灭效果相当,但持效性能优异.该研究获得的联苯菊酯微胶囊为安全、高效防治白蚁提供了技术手段.     

6种复配杀虫剂对七星瓢虫的毒力测定及风险评估

采用药膜法分别测定了10％甲维盐·茚虫威悬浮剂、12％甲维盐·虫螨腈悬浮剂、12％虫螨腈·虱螨脲悬浮剂、14％呋虫胺·螺虫乙酯悬浮剂、22％吡虫啉·螺虫乙酯悬浮剂和6％吡虫啉·高效氯氟氰菊酯悬浮剂6种复配杀虫剂对七星瓢虫Coccinella septempunctata Linnaeus幼虫急性毒性,并进行了初级风险评估.结果 显示,6种药剂对七星瓢虫48 h的LR5o(半致死用量,Median lethal rate)分别为0.812、2.255、4.082、22.735、6.755和0.00467 g a.i/hm2.在农田内暴露场景下,6种复配杀虫剂对七星瓢虫风险均不可接受;在农田外暴露场景下,仅有14％呋虫胺·螺虫乙酯悬浮剂和22％吡虫啉·螺虫乙酯悬浮剂对七星瓢虫风险可接受,其它均不可接受.结果 表明在田间最大推荐用量下,6种药剂对七星瓢虫的初级风险评价均存在高风险.     

Single-cell transcriptomics of cardiac progenitors reveals functional subpopulations and their cooperative crosstalk in cardiac repair

Dear Editor,Myocardial infarction is one of the leading causes of morbidity and mortality.Stem/progenitor cells therapy has emerged as a promising strategy for the cardiac repair,especially those derived from cardiac tissue,have attracted worldwide attention(Tompkins et al.,2018).However,challenges and controversies remain in characterizing functional progenitors and explaining their mechanisms of action.