血清DCN、NRG-1、MIF水平与首发未服药精神分裂症患者临床症状和认知功能的相关性分析

目的:探讨血清核心蛋白多糖(DCN)、神经调节蛋白-1(NRG-1)、巨噬细胞迁移抑制因子(MIF)水平与首发未服药精神分裂症患者临床症状和认知功能的相关性。方法:选择2018年1月~2020年11月期间长江大学附属第一医院收治的首发未服药精神分裂症患者80例作为精神分裂症组,同期于长江大学附属第一医院进行体检的健康志愿者80例作为对照组。应用阳性和阴性症状量表(PANSS)评估患者精神病理症状,应用MATRICS共识认知成套测验(MCCB)评估所有受试者认知功能。根据PANSS评分将精神分裂症组分为PANSS评分高分组和低分组,比较两组血清DCN、NRG-1、MIF水平,并分析以上指标水平与PANSS总分、MCCB各项评分的相关性。结果:精神分裂症组患者PANSS总分为(77.18±13.57)分。精神分裂症组MCCB各项评分均低于对照组(P<0.05)。精神分裂症组血清DCN、NRG-1水平低于对照组,MIF水平高于对照组(P<0.05)。PANSS高分组血清DCN、NRG-1水平低于PANSS低分组,MIF水平高于PANSS低分组(P<0.05)。Pearson相关性分析显示,首发未服药精神分裂症患者血清DCN、NRG-1水平与PANSS总分呈负相关,与MCCB各项评分呈正相关,MIF水平与PANSS总分呈正相关,与MCCB各项评分呈负相关(均P<0.05)。结论:首发未服药精神分裂症患者血清DCN、NRG-1、MIF水平异常,且以上指标水平与患者临床症状和认知功能受损有一定联系,提示检测以上指标水平可能为该病患者认知功能及临床症状的评估提供参考。     

Reducing acetylated tau is neuroprotective in brain injury

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QTL analysis of pasta quality using a composite microsatellite and SNP map of durum wheat

Bright yellow color, firmness and low cooking loss are important factors for the production of good-quality pasta products. However, the genetic factors underlying those traits are still poorly understood. To fill this gap we developed a population of 93 recombinant inbred lines (RIL) from the cross between experimental line UC1113 (intermediate pasta quality) with the cultivar Kofa (excellent pasta quality). A total of 269 markers, including 23 SNP markers, were arranged on 14 linkage groups covering a total length of 2,140 cM. Samples from each RIL from five different environments were used for complete pasta quality testing and the results from each year were used for QTL analyses. The combined effect of different loci, environment and their interactions were analyzed using factorial ANOVAs for each trait. We identified major QTLs for pasta color on chromosomes 1B, 4B, 6A, 7A and 7B. The 4B QTL was linked to a polymorphic deletion in the Lpx-B1.1 lipoxygenase locus, suggesting that it was associated with pigment degradation during pasta processing. The 7B QTL for pasta color was linked to the Phytoene synthase 1 (Psy-B1) locus suggesting difference in pigment biosynthesis. QTLs affecting pasta firmness and cooking loss were detected on chromosomes 5A and 7B, and in both cases they were overlapping with QTL for grain protein content and wet gluten content. These last two parameters were highly correlated with pasta firmness (R > 0.71) and inversely correlated to cooking loss (R < −0.37). The location and effect of other QTLs affecting grain size and weight, gluten strength, mixing properties, and ash content are also discussed. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

基于数字PCR的单分子DNA定量技术研究进展

数字PCR是一项针对单分子目标DNA的绝对定量技术．该技术是将含有DNA模板的反应溶液分配到大量独立的反应室中并且发生扩增反应,通过统计反应室中的阳性信号来定量DNA的拷贝数．DNA样品在反应室中随机和独立分布是单分子成功扩增和准确定量DNA拷贝数的关键因素．本文综述了数字PCR的发展历史、数字PCR与实时荧光定量PCR的区别,以及数字PCR在临床诊断、转基因成分定量、单细胞基因表达、环境微生物检测和下一代测序等方面的最新进展,并展望了该技术的应用前景．     

DNA and nucleotide-induced conformational changes in the Escherichia coli Rep and helicase II (UvrD) proteins

The domain structures of the Escherichia coli Rep and Helicase II proteins and their ligand-dependent conformational changes have been examined by monitoring the sensitivity of these helicases to proteolysis by trypsin and chymotrypsin. Limited treatment of unliganded Rep protein (73 kDa) with trypsin results in cleavage at a single site in its carboxyl-terminal region, producing a 68-kDa polypeptide which is stabilized in the presence of ATP, ADP, or adenosine 5'-O-thiotriphosphate) (ATP gamma S). The purified 68-kDa Rep tryptic polypeptide retains single-stranded (ss) DNA binding, DNA unwinding (helicase), and full ATPase activities. When bound to ssDNA, the Rep protein can be cleaved by trypsin at an additional site in its carboxyl-terminal region, producing a 58-kDa polypeptide that also retains ssDNA binding and ATPase activities. This 58-kDa Rep tryptic polypeptide can also be produced by further tryptic treatment of the 68-kDa Rep tryptic polypeptide when the latter is bound to ssDNA. This 58-kDa polypeptide displays a lower affinity for ssDNA indicating that the 10-kDa carboxyl-terminal peptide facilitates Rep protein binding to ssDNA. The 58-kDa Rep tryptic polypeptide is also stabilized in the presence of nucleotides. Based on these and previous studies that showed that the 68-kDa Rep tryptic polypeptide cannot support DNA replication in a system that is dependent upon the phi X174 cis-A protein (Arai, N. & Kornberg, A. (1981) J. Biol. Chem. 256, 5294-5298), we conclude that the carboxyl-terminal end (approximately 5 kDa) of the Rep protein is not required for its helicase or ATPase activities. However, we suggest that this region of the Rep protein is important for its interactions with the phi X174 cis-A protein. Limited treatment of unliganded Helicase II protein (82 kDa) with chymotrypsin results in cleavage after Tyr254, producing a 29-kDa amino-terminal polypeptide and a 53-kDa carboxyl-terminal polypeptide, which remain associated under nondenaturing conditions. This chymotrypsin cleavage reduces the ssDNA binding activity and eliminates the ssDNA-dependent ATPase and helicase activities of the Helicase II protein. The binding of ATP, ADP, ATP gamma S, and/or DNA to Helicase II protein results in protection of this site (Tyr254) from cleavage by chymotrypsin. Limited treatment of Helicase II protein with trypsin results in cleavage near its carboxyl-terminal end producing two polypeptides with apparent Mr = 72,000, in a manner similar to that observed with the Rep protein; these polypeptides are also stabilized by binding ATP or single-stranded DNA.(ABSTRACT TRUNCATED AT 400 WORDS)     

西江下游浮游植物群落周年变化模式

西江肇庆段是珠江干流汇入珠三角河网水域的咽喉通道,对2009年该江段的浮游植物群落组成及变化进行系统阐析.调查期间共发现浮游植物7门,245种(包括变种、变型),其中硅藻和绿藻是浮游植物群落组成的最主要类群,分别占总种数的42.44％和34.69％,其次是裸藻和蓝藻.PCA分析结果显示,浮游植物各类群的种类丰富度和生物量的周年变化趋势主要受水温和径流量的影响.浮游植物种类丰富度的周年变化呈现明显的高温季节高,低温季节低的特征,除因大多数藻类物种直接喜好高温之外,径流量的增大有助于真浮游绿藻种类的外源注入及半浮游和偶然性浮游硅藻种类的增加.浮游植物生物量的周年变化呈现明显的双峰型,峰值分别出现在8月和11月.然而8月份第1个高峰出现之前,生物量波动不大,尽管水温的升高有助于生物量的增加,但是径流量增大所带来的稀释作用掩盖了水温上升对浮游植物生长的促进作用.真浮游植物生物量的变化趋势和数值与总浮游植物极其接近,主要得益于真浮游硅藻物种颗粒直链藻在总种群中的绝对优势地位.综上,水温升高对浮游植物种类丰富度和生物量的增长均有促进,径流量的增大虽然有助于种类丰富度的增加,但不利于生物量的增加.     

Mediator structure and conformation change

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Kinematics,Deformation,and Aerodynamics of a Flexible Flapping Rotary Wing in Hovering Flight

The Flapping Rotary Wing(FRW)is a micro air vehicle wing layout coupling flapping,pitching,and rotating motions.It can gain bencfits in high lift from a fast passive rotating motion,which is tightly related to the passive pitching motion directly caused by wing flexible deformation.Therefore,flexible deformation is crucial for the wing kinematics and aerodynamic performance of an FRW.In this paper,we explored the effct of flexibility on wing kinematics and acrodynamics on the basis of a mechanical FRW model.A photogrammetric method was adopted to capture motion images according to which wing orientations and deformations were reconstructed.Corresponding acrodynamic force was computed using computational fluid dynamic method,and wing kinematics and deformations were used as simulation inputs.The experimental measurements presented the real orientation and deformation pattem of a real FRW.The wing passive deformation of a high-intensity FRW was found to be mainly caused by inertial force,and a linear positive spanwise twist was observed in the FRW.The effects of wing deformation on aerodynamic force production and the underlying mechanism were addressed.Results showed that lift augment,rotating moment enhancement,and power efficiency improvement can be achieved when a wing becomes flexible.Wing spanwise twist mainly accounts for these changes in aerodynamics,and increment in spanwise twist could further contributes to aerodynamic improvement.     

CAP1, a target of miR-144/451, negatively regulates erythroid differentiation and enucleation

The exact molecular mechanism underlying erythroblast enucleation has been a fundamental biological question for decades. In this study, we found that miR-144/451 critically regulated erythroid differentiation and enucleation. We further identified CAP1, a G-actin-binding protein, as a direct target of miR-144/451 in these processes. During terminal erythropoiesis, CAP1 expression declines along with gradually increased miR-144/451 levels. Enforced CAP1 up-regulation inhibits the formation of contractile actin rings in erythroblasts and prevents their terminal differentiation and enucleation. Our findings reveal a negative regulatory role of CAP1 in miR-144/451-mediated erythropoiesis and thus shed light on how microRNAs fine-tune terminal erythroid development through regulating actin dynamics.     

Pericytes augment glioblastoma cell resistance to temozolomide through CCL5-CCR5 paracrine signaling

Glioblastoma (GBM) is a prevalent and highly lethal form of glioma, with rapid tumor progression and frequent recurrence. Excessive outgrowth of pericytes in GBM governs the ecology of the perivascular niche, but their function in mediating chemoresistance has not been fully explored. Herein, we uncovered that pericytes potentiate DNA damage repair (DDR) in GBM cells residing in the perivascular niche, which induces temozolomide (TMZ) chemoresistance. We found that increased pericyte proportion correlates with accelerated tumor recurrence and worse prognosis. Genetic depletion of pericytes in GBM xenografts enhances TMZ-induced cytotoxicity and prolongs survival of tumor-bearing mice. Mechanistically, C-C motif chemokine ligand 5 (CCL5) secreted by pericytes activates C-C motif chemokine receptor 5 (CCR5) on GBM cells to enable DNA-dependent protein kinase catalytic subunit (DNA-PKcs)-mediated DDR upon TMZ treatment. Disrupting CCL5-CCR5 paracrine signaling through the brain-penetrable CCR5 antagonist maraviroc (MVC) potently inhibits pericyte-promoted DDR and effectively improves the chemotherapeutic efficacy of TMZ. GBM patient-derived xenografts with high CCL5 expression benefit from combined treatment with TMZ and MVC. Our study reveals the role of pericytes as an extrinsic stimulator potentiating DDR signaling in GBM cells and suggests that targeting CCL5-CCR5 signaling could be an effective therapeutic strategy to improve chemotherapeutic efficacy against GBM.Subject terms: Cancer microenvironment, CNS cancer, Cancer therapy