中国药用当归属植物研究进展及质量标志物的预测分析*

中国药用当归属植物资源丰富,包括当归、白芷、独活等34种药材,临床使用广且药用价值极高,富含香豆素类、多糖类、有机酸类、苯酚类、挥发油类等成分,除补血活血、调经止痛、润肠通便的传统功效,还具有抗氧化、抗衰老、保护神经元、抗肿瘤等药理作用,应用前景广阔。综述了中国药用当归属植物的分布及其药用功效、化学成分和药理作用的研究进展,为当归属植物的开发利用提供参考。并且根据质量标志物(Q-marker)概念,把影响中国药用当归属植物质量的因素概括为当归属药用植物品种、植物产区、化学成分、炮制方法,以及传统功效和网络药理学的预测分析等。从不同方面对中国药用当归属植物进行分析和论述,为建立和完善中国药用当归属植物的质量控制及评价方法提供参考。     

亚洲虎种群恢复的机遇与挑战

虎(Panthera tigris)作为顶级捕食者, 对维持森林生态系统服务和结构完整性有着重要作用, 是研究和保护工作的旗舰物种。历史上, 虎曾广泛分布于亚洲大部分地区, 如今仅分布于南亚、东南亚和东北亚的破碎化栖息地, 各区域种群处于濒危或极度濒危状态。准确了解野生虎的种群状态和生态需求信息对于科学开展保护和恢复工作至关重要。本文通过综述近几十年的研究文献, 总结了野生虎种群现状和主要威胁因素, 评价了已有研究的重点与不足, 为未来亚洲虎种群的研究和保护提出了建议。目前与虎相关的研究主要集中在分布范围最广的孟加拉虎(P. t. tigris)和东北虎(P. t. altaica) 2个亚种, 而最急需关注的其他亚种仍研究不足。经过近十几年的努力和保护投入, 目前野生虎种群数量已从2010年的大约3,200只恢复到现在约4,500只, 但在越南、柬埔寨和老挝3个国家已经灭绝。虎面临的主要威胁包括持续的栖息地破坏和隔离、猎物缺乏、近交衰退、人虎冲突、贸易与盗猎和疾病威胁等。未来的研究和保护工作需要加强种群和栖息地连通性恢复、个体重引入、疾病管控以及加强跨境合作和反盗猎等。     

miR-483 inhibits bovine myoblast cell proliferation and differentiation via IGF1/PI3K/AKT signal pathway

MicroRNAs (miRNAs) have been established to regulate skeletal muscle development in mammals. However, few studies have been conducted on the regulation of proliferation and differentiation of bovine myoblast cells by miRNAs. The aim of our study was to explore the function of miR-483 in cell proliferation and differentiation of bovine myoblast. Here, we found that miR-483 declined in both proliferation and differentiation stages of bovine myoblast cells. During the proliferation phase, the overexpression of miR-483 downregulated the cell cycle–associated genes cyclin-dependent kinase 2 (CDK2), proliferating cell nuclear antigen (PCNA) messenger RNA (mRNA), and the protein levels. At the cellular level, cell cycle, cell counting kit-8, and 5-ethynyl-2´-deoxyuridine results indicated that the overexpression of miR-483 block cell proliferation. During differentiation, the overexpression of miR-483 led to a decrease in the levels of the myogenic marker genes MyoD1 and MyoG mRNA and protein. Furthermore, the immunofluorescence analysis results showed that the number of MyHC-positive myotubes was reduced. In contrast, the opposite experimental results were obtained concerning both proliferation and differentiation after the inhibition of miR-483. Mechanistically, we demonstrated that miR-483 target insulin-like growth factor 1 (IGF1) and downregulated the expression of key proteins in the PI3K/AKT signaling pathway. Altogether, our findings indicate that miR-483 acts as a negative regulator of bovine myoblast cell proliferation and differentiation.     

Spatial distribution,pollution levels,and source identification of heavy metals in wetlands of Suzhou Industrial Park,China

Wetlands Ecology and Management - As one of the earliest national demonstration ecological industrial parks (EIPs) in China, Suzhou Industrial Park (SIP) is developed on the principles of material...     

NKG2D discriminates diverse ligands through selectively mechano‐regulated ligand conformational changes

Stimulatory immune receptor NKG2D binds diverse ligands to elicit differential anti‐tumor and anti‐virus immune responses. Two conflicting degeneracy recognition models based on static crystal structures and in‐solution binding affinities have been considered for almost two decades. Whether and how NKG2D recognizes and discriminates diverse ligands still remain unclear. Using live‐cell‐based single‐molecule biomechanical assay, we characterized the in situ binding kinetics of NKG2D interacting with different ligands in the absence or presence of mechanical force. We found that mechanical force application selectively prolonged NKG2D interaction lifetimes with the ligands MICA and MICB, but not with ULBPs, and that force‐strengthened binding is much more pronounced for MICA than for other ligands. We also integrated steered molecular dynamics simulations and mutagenesis to reveal force‐induced rotational conformational changes of MICA, involving formation of additional hydrogen bonds on its binding interface with NKG2D, impeding MICA dissociation under force. We further provided a kinetic triggering model to reveal that force‐dependent affinity determines NKG2D ligand discrimination and its downstream NK cell activation. Together, our results demonstrate that NKG2D has a discrimination power to recognize different ligands, which depends on selective mechanical force‐induced ligand conformational changes.     

甘肃鼢鼠骨骼13种微量元素测定

对甘肃鼢鼠(Myospalax cansus)骨骼中Fe、Cu、Zn、Mn、Cr、Ni、Co、Mo、Cd、As、Pb、F、Al等13种微量元素进行了测定。结果表明,甘肃鼢鼠全骨中13种元素含量依次为Al>Fe>Zn>F>Mn>Cu>Pb>As>Cr>Co>Ni>Mo>Cd;同一元素在不同骨骼分布不均,头骨最丰富,除Zn、Mn外,同一元素在不同部位骨骼的含量存在显著差异;13种微量元素之间的相关性,Zn-Pb、Mn-Cd、As-Pb3组呈显著负相关(0.01相似文献   

川硬皮肿腿蜂染色体制备方法探讨

对川硬皮肿腿蜂Scleroderma sichuanensis Xiao(Hymenoptera:bethylidae Sclerderma)染色体制备方法进行了探讨,结果表明;以川硬皮肿腿蜂雌成虫卵巢为材料,经0.01%秋水仙素水溶液处理10min,蒸馏水低渗5min,用甲醇、冰醋酸(3∶1)固定液固定15min,Giemsa染液染色30min,可以获得形态良好、分散适中、着色清晰的染色体.     

牛视网膜微血管内皮细胞的培养和鉴定

牛视网膜微血管内皮细胞的培养和鉴定ＣＵＬＴＵＲＥＡＮＤＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦＢＯＶＩＮＥＲＥＴＩＮＡＬＣＡＰＩＬＬＡＲＹＥＮＤＯＴＨＥＬＩＡＬＣＥＬＬ关键词内皮细胞微血管视网膜体外培养牛ＫｅｙｗｏｒｄｓＥｎｄｏｔｈｅｌｉａｌｃｅｌｓ,...     

植物肉桂酰辅酶A还原酶基因克隆研究进展

木质素单体合成的过程中涉及了许多酶的参与,而肉桂酰辅酶A还原酶(cinnamoyl-CoA reductase,CCR)是该过程中的一个关键酶。综述了CCR基因在植物体内的克隆、基因功能及在植物组织中的表达情况,并介绍了该基因在植物的抗病虫害和抗逆性研究、饲草和能源上的应用潜力,为进一步研究CCR基因生物学功能和利用奠定了基础。