强风沙流吹袭对樟子松幼苗生长特性及其逆境生理特征的影响

为了解樟子松幼苗对强风沙流不同时间吹袭的生理生态响应,2013年春季在内蒙古科尔沁沙地研究了8级大风下强风沙流(风速18 m·s-1,风沙流强度173 g·cm-1·min-1)吹袭10、20和30 min樟子松幼苗生长特性和一些生理指标的变化。结果表明:随着风吹时间增加,其株高生长速率下降,茎粗和冠幅生长加快,叶色发黄脱落量增加;与非风吹对照(CK)相比,30 min风吹处理的株高增长量下降52.6%,茎粗增长量、冠幅增长量和叶色发黄脱落量分别增加251.9%、256.0%和466.7%;随风吹时间增加,叶片相对含水量(RWC)和超氧化物歧化酶(SOD)活性下降,丙二醛(MDA)含量、膜透性、过氧化物酶(POD)活性、可溶性糖和脯氨酸含量趋于增加;与CK相比,30 min风吹处理的RWC下降4.1%,MDA和膜透性分别增加10.3%和9.3%,SOD活性下降1.9%,POD活性、可溶性糖和脯氨酸含量分别增加55.5%、26.4%和50.0%。结果说明,强风沙流持续吹袭造成樟子松幼苗水分胁迫,使其高生长受抑,部分叶片发黄脱落,叶片膜脂过氧化加剧,细胞膜受损,为适应强风沙流吹袭,樟子松幼苗加快了茎粗和冠幅生长,通过增加POD活性和可溶性糖、脯氨酸含量以减轻细胞膜伤害,维持细胞正常膨压。     

基于牧户感知和野外调查相结合的内蒙古东部草甸草原健康评价

治理草原退化是我国草原管理的重点和难点。我国目前关于草原退化判断、退化程度、原因及治理等系列问题的确定几乎皆以科学研究结果为依据,而忽视了牧户作为草原直接使用者和管理者的重要性。牧户对草原有自己的判断和认知,其与科学方法研究之间的矛盾已经影响到草原生态保护政策的有效实施。以内蒙古东部草甸草原牧户尺度草原为研究对象,借助牧户调研和野外调查相结合的方法,将牧户划分为高、中、低3个经济水平,并运用Condition-Vigor-Organization-Resilience (CVOR)指数评价法,分析评价草原生态系统健康状况。研究结果显示,牧户对草原健康状况的感知主要从植被、土壤、牲畜等方面,与科学方法评价指标选取具有相似性;牧户感知和CVOR指数法评价结果具有一致性,均判定草原生态系统呈现不同程度退化;统计检验显示牧户对植被、土壤、牲畜影响等指标变化感知方面均不存在显著差异(P0.05),CVOR指数法下不同经济水平牧户草场健康指数之间亦无显著差异(P0.05),两种方法均显示不同经济水平牧户草场退化程度无显著差异(P0.05)。研究证实了牧户感知在指标选取、评价结果方面具备用于准确评价草原健康状况的可行性和可信度。两种方法相互补充,将有利于更加准确、实时动态监测和评价牧户尺度草原生态健康状况,为调整优化畜牧业生产实践提供指导和草原生态保护和建设政策的有效实施提供保障。     

蜘蛛体内Wolbachia的快速检测

将蜘蛛匀浆离心后的上清液直接作为PCR反应的模板,用于检测蜘蛛体内的Wolbachia.该方法简便、无污染,与常规方法提取蜘蛛总DNA的检测效果相同,可以用于快速和大量检测蜘蛛体内的Wolbachia感染情况.     

The gnd gene of Buchnera as a new,effective DNA barcode for aphid identification

DNA barcoding uses a standard DNA sequence to facilitate species identification. Although the COI gene has been adopted as the standard, COI alone is imperfect due to several shortcomings. The primary endosymbiont of aphids, Buchnera, has higher evolutionary rates and interspecies divergence than its co‐diverging aphid hosts, making it a potential tool for resolving the ambiguities in aphid taxonomy. We compared the effectiveness of employing two different DNA regions, gnd and COI, for the discrimination of over 100 species of aphids. The mean interspecific divergence of the gnd region was significantly higher than the mean intraspecific variation; there were nearly nonoverlapping distributions between the intra‐ and interspecific samples. In contrast, COI showed a lower interspecific divergence, which led to difficulties in identifying closely related species. Our results show that gnd can identify species in the Aphididae, which suggests that the gnd region of Buchnera is a potentially effective barcode for aphid species identification. We also recommend the 2‐locus combination of gnd + COI as the aphid barcode. This will provide a universal framework for the routine use of DNA sequence data to identify specimens and contribute toward the discovery of overlooked species of aphids.     

Nrf2调控的铁死亡途径在非酒精性脂肪性肝病防治中的作用机制

非酒精性脂肪性肝病（NAFLD）是发病率很高的慢性肝病类型,与肥胖、糖尿病、高脂血症等代谢综合征密切相关,是当前重要的公共健康问题之一。其具体的发病机制尚不清楚。目前有研究认为铁死亡参与了NAFLD的发生与发展,铁死亡是一种新型程序性细胞死亡。核因子E2相关因子2 (Nrf2)是调控铁死亡过程中的重要核因子,对铁死亡过程中抗氧化、铁代谢以及脂质过氧化途径起到调控作用,并且已被报道可能通过抑制铁死亡改善NAFLD。本文通过对铁死亡与NAFLD的关系研究进行梳理,探究Nrf2调控铁死亡改善NAFLD的可能机制。最后,对存在的问题进行分析并提出未来研究展望。     

Multicellular thallophytes with differentiated tissues from Late Proterozoic phosphate rocks of South China

An assemblage of megascopic, multicellular thallophytes with well-preserved tissues and microstructures was discovered in phosphate rocks of the Late Proterozoic Doushantuo Formation (approximately 680 Ma old) at the Wengan-Fuquan Phosphate Mines, Guizhou Province, South China. Two new genera and three new species are erected: Thallophyca ramosa n. gen. et n. sp., Thallophyca simplica n. gen. et n. sp. and Wengania globosa n. gen. et n. sp. The thalli of Thallophyca are embedded in amorphous collophane and consist of differentiated tissues interpreted as cortex and medulla, and distinct structures (conceptacle-like cavities and special cell-groups or 'cell-islands'). Tissue differentiation and megascopic (millimetric to centrimetric) size of the thalli suggest that the new genus Thallophyca may represent a primitive metaphyte. The new genus Wengania is assigned to the Paleozoic algal group Solenoporaceae Pia. This study provides reliable fossil evidence of Late Proterozoic metaphytes and leads to the following conclusions: (1) diverse multicellular thallophytes had evolved during Late Proterozoic Ediacaran time; (2) adaptive radiations possibly took place more or less contemporaneously in both metazoans and metaphytes, and (3) Precambrian phosphate rocks can preserve megafossils with delicate microstructures.     

Neuronal Cell Death of Abdominal Ganglia (A3) and Characterization of Neuron-Killing Factor in Ventral Nerve Cord from Sweet Potato Hornworm, Agrius convolvuli

ABSTRACT The central nervous system of Agrius convolvuli is composed of brain, followed by subesophageal ganglion, three thoracic ganglia, and eight abdominal ganglia in late larval stage. After metamorphic transition from larva to pupa, thoracic (T₁ and T₂) and abdominal ganglia (A₁ and A₂) are moved toward T₃ and fused together to construct composite ganglion, pterothoracic ganglion. The formation of composite ganglion is completed about 90% at 4 day and 100% at 7 day after pupation. Neuronal cell death was occurred significantly around 3 or 4 day after pupation and just after adult ecdysis. Although 170 neurons were detected 3 day before adult ecdysis, 24 cells were counted 5 day after adult ecdysis. Data of scanning and tandem electron microscope showed the symptom of cell death. In order to identify the mechanism of cell death in A. convolvuli , 1,200 ventral nerve cords were homogenized. Extracts were boiled for 3 minutes at 100°C and collected below 30,000 dalton of molecular mass. Each fraction from reverse phase column chromatography by HPLC system was tested in ventral nerve cord culture system, and fractions having killing activity in culture were isolated. By the addition of 20 hydroxyecdysone, actinomycin D, or cycloheximide into the culture medium, cell death was delayed significantly when compared to control group.     

急性低氧下钙阻断剂对左,右心泵功能的影响

在20条麻醉开胸狗上,用RM-6000多道仪同步记录左心室内峰压(LVP)、左室压力变化率(L+dP/dt_(max))、右心室内峰压(RVP)、右室压力变化率(R±dp/dt_(max))、肺动脉压力(P_(Pa))、主动脉血流每搏峰值(Fa)、心率(HR)等各项生理指标,观察钙通道阻断剂Nife-dipine,Diltiazem和Verapamil对左、右心室功能影响。在钙通道阻断剂处理后,左室的LVP,L±dp/dt_(max)下降,而Fa增加;右室的RVF,R±dp/dt_(max)和P_(Pa)均有升高趋势,显示钙通道阻断剂对左、右心泵功能的影响不同。这可能提示左、右心室功能对钙离子的依赖程度不同。在急性低氧状态下,此三种钙阻断剂均使急性低氧引起LVP的增加反应消失,Fa增加明显,Verapamil和Diltiazem有减轻急性低氧引起的RVP和P_(Pa)的增压作用。从这些钙通道阻断剂对左右心泵功能影响的比较来看,Diltiazem比Verapamil和Nifedipine对急性低氧状态下的心泵功能有较好的作用。     

The apoptosis of HEL cells induced by hydroxyurea

INTRODUCTIONApoptosis(programmedcelldeath)playsafundamentalroleduringinvertebrateandvertebratedevelopment.Theoriginofhumancancermaybeassociatedwiththefailureofendangeredcellstoundergoapoptosis.Apoptosishasbeenobservedinmanydifferentcellsandinresponsetomanyphysiologicalsignalsortypesofstress[1,2].Itcanbeinducedbyglucocorticoidtreatment,exposuretoCa2 ionophoresorac--irradiationofmousethymocytesandgrowthfactordeprivationofbothhematopoieticandlymphoidcellsinvitro[3,4].Hydroxyureacanstimulate…     

国产合瓣花植物名称的后选模式指定——Ⅰ. 杜鹃花科

在整理保存于中国科学院植物研究所中国国家植物标本馆（PE）的国产合瓣花植物模式标本时,根据《国际藻类、菌类、植物命名法规》（墨尔本法规）规则9.5,发现一些植物名称的模式为合模式,其中包括杜鹃花科的奇异杜鹃、怒江杜鹃、绢毛杜鹃、橙黄杜鹃、光蕊杜鹃、棕背川滇杜鹃、拟镰果杜鹃、镰果杜鹃、粘毛杜鹃、粗毛杜鹃、腾冲杜鹃、剑川杜鹃和红粗毛杜鹃。遵照规则8.1、9.11和9.12,以及辅则9A.3的精神,对这13个名称做出后选模式指定。