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1.
导水管周围灰质(periaqueductal gray,PAG)在疼痛的调控过程中处于一个不可或缺的位置.其不仅是痛觉信息上行传递的重要部位,还是疼痛抑制系统的重要组成部分.在PAG,包括γ-氨基丁酸(γ-aminobutyric acid,GABA)、5-羟色胺(5-hydroxytryptamine,5-HT)和谷氨酸(glutamate,Glu)在内的神经递质以及内源性阿片肽(endogenous opioid peptides,EOP)和内源性大麻素(endocannabinoid,e CB)为代表的神经调质都参与了PAG对疼痛的信息传递以及调节.本文重点综述GABA、5-HT、Glu、EOP和eCB在PAG参与疼痛生理调控机制的研究进展,以期为中枢神经系统的镇痛研究提供一定的理论基础.  相似文献   
2.
Abstract  All ants (Hymenoptera, Formicidae) are highly eusocial insects that are characterized by reproductive division of labor with sterile castes (worker and soldier) helping fertile castes (queen and male) to reproduce.
Ant societies, like other complex animal societies, have developed a sophisticated communication system, in which recognition behaviors are frequently involved Recognition abilities allow individuals to orient and modulate their behaviors effectively and appropriately in response to the characteristics andlor signals expressed by other organisms. Among recognition behaviors, nestmate recognition and kin recognition mechanisms have attracted great attention of sociobiologists, ecologists, insect physiologists and biochemists since 1970's. This is parallel with the popularization of Hamilton's kin selection theory. The present paper aims at reviewing the current understanding on nestmate/kin recognition in ants. This review consists of three parts. The first part concerns the diversity of recognition behaviors and their ecological implications with emphasis on nestmatelkin recognition; in the second part, the current understandings on the mechanism of nestmatelkin recognition are outlined; and in the third part, we discuss the ontogenetic development of nestmate recognition behavior and naturally mixed colonies. The study of the integration mechanism of social parasite may provide heuristic clues to the understanding of kin/nestmate recognition system.  相似文献   
3.
在整理由青海省采得蝗虫标本时,发现1新种,记述如下。模式标本保存于山东大学生物系。青海雏蝗Chorthippus qinghaiensis,新种(图1—8) 雄:体小型。头部短于前胸背板。头顶平,侧缘明显隆起,顶锐角形。头侧窝狭长方形,长为宽的3.3倍。颜面向后倾斜,颜面隆起纵沟较浅,具刻点,侧缘在中眼处略狭。触角丝状,中段一节长为宽的1.4倍。复眼较小,卵圆形,纵径为横径的1.3倍,  相似文献   
4.
中国稻蝗属细胞分类学研究(英文)   总被引:4,自引:0,他引:4  
本文对分布于中国境内11省区,27个采集地点的八种稻蝗进行了染色体C带核型比较研究。结果表明:中华稻蝗Oxya chinensis,上海稻蝗O.shanghaiensis,无齿稻蝗O.adentata C带分布型式相似,但染色体分组型式、交叉定位数据以及异染色质含量具有差异;山稻蝗O.agauisa具有本身独特的带纹结构,与本属其它种类迥异;双带稻蝗O.bicingula染色体带型结构相似于山稻蝗及中华稻蝗类群,表明三者在进化历程中有一定联系。小稻蝗O.hyla intricata中一个亲缘种团(Sibling species group),体现在种内的形态差异及染色体带型结构的不同。显示该种近期内分化速率较高。据此,本文讨论了稻蝗属内八个种相互间的亲缘关系和分类地位,本文认为稻蝗属内务物种进化速率是不均衡的,这种状态应归因于各物种的遗传背景和环境因素的影响。  相似文献   
5.
Black cumin (Nigella sativa) seed protein (BCSP) was individually hydrolyzed with pepsin, trypsin, and α-chymotrypsin. After ultrafiltration, the α-chymotrypsin hydrolysate (< 3 kDa) exhibited the highest ACE inhibitory (ACEI) activity with an IC50 value of 34.4 ± 1.5 μg/mL. This hydrolysate was orthogonally fractionalized using reversed-phase high-performance liquid chromatography (RP-HPLC) and strong cation exchange (SCX) chromatography, and the most active RP-HPLC and SCX fractions (F7 and H4, respectively) were individually screened out by ACEI assay. These two fractions were analyzed with liquid chromatography-tandem mass spectrometry (LC–MS/MS) followed by automated de novo peptide sequencing, and totally 43 ACEI candidate peptides were identified. Three overlapping peptides (VTPVGVPKW, VVTPVGVPKW, and LVLTL) were simultaneously contained in both fractions, and VTPVGVPKW (VW-9) was speculated as to the most potent ACEI peptide based on the in silico analysis. Synthetic VW-9 was used to confirm the identity, and a remarkable IC50 value of VW-9 (1.8 ± 0.09 μM) was determined. Preincubation and inhibition mechanism studies indicated that VW-9 was a true inhibitor as well as a non-competitive inhibitor on ACE, which was further illustrated with the molecular docking simulation. Our study revealed that the application of VW-9 to antihypertensive products is promising.  相似文献   
6.
侯祥  韩宁  封托  张博  陈晓宁  王京  常罡 《生态学报》2020,40(14):4836-4841
受全球气候变化的影响,气候因素与害鼠种群变化之间的关系成为害鼠防治研究中的热点问题。以西安市长安区周边分布的黑线姬鼠为研究对象,通过标志重捕法进行种群动态监测,掌握其种群数量的动态变化规律,并结合非线性的统计方法广义可加模型,对该地区2015—2018年黑线姬鼠种群密度和气候因素数据进行分析,探讨该鼠种群变化与气候因素之间的关系。结果表明,该地区黑线姬鼠种群数量总体显现为下降趋势。黑线姬鼠种群密度存在显著的正向自我调节效应(F_(1.00, 5.77)=27.062,P0.01),且与上一月种群密度存在线性的正相关。当月平均温度与该鼠种群密度之间存在显著的非线性效应(F_(1.90, 5.77 )=4.696,P0.05),两者之间显现为钟型关系,当温度21℃时,两者之间显现为正相关,黑线姬鼠种群密度随温度的升高而升高,反之显现为负相关。当月累计降雨量与其种群密度之间也存在显著的非线性效应(F_(1.87, 5.77)=3.879,P0.05),同样,两者之间也显现为钟型关系,当降雨量90 mm时,两者之间显现为负相关,种群密度随降雨量的增加而降低,反之显现为正相关。因此,温度和降雨对黑线姬鼠种群变化具有调节作用,低温干旱和高温多雨均不适合该鼠的繁殖与生长。  相似文献   
7.
Menispermaceae is one of the core groups of Ranunculales. The single fertile ovule in each ovary in Menispermaceae varies greatly in integument number, micropyle formation, and integument lobe. However, data regarding ovule morphogenesis in the family are very limited. In this study, we document ovule development of selected species in the Menispermaceae using scanning electron microscopy and light microscopy. Ovule development in Menispermaceae shows the following characteristics. Two ovules are initiated in a young carpel, one of them degenerates gradually and the other develops into a fertile ovule in subsequent stages. Bitegmic in Sinomenium Diels. and Cocculus DC. and unitegmic in Stephania Lour. The formation of unitegmy is probably due to integumentary shifting. The annularly initiated inner integument is of dermal origin and has 2–3 cell layers in the family, but the semi-annularly initiated outer integument is of both dermal and subdermal origin. Both inner and outer integument are cup-shaped at maturity. The cup-shaped outer integument is formed due to the outer integument's extension to the concave (adaxial) side of the funiculus. The obturator is well developed and consists of 2–3 cell layers in Cocculus or 9–11 cell layers in Stephania. Ovule development of Menispermaceae suggests some common characteristics between Cocculus and Sinomenium, and derived unitegmy supports molecular data that indicate Stephania is one of the late-diverging lineages in the family. Integument lobations are present. The sterile ovule shows variations in the degeneration process. These results will provide evidence for exploring the evolution of ovules in Ranunculales.  相似文献   
8.
直系同源(orthology)是指由于物种形成事件而享有共同祖先的基因之间的关系,直系同源基因之间通常具有相似的结构和生物学功能.由于基因组和转录组序列的快速积累,精确的识别直系同源基因有助于功能基因的注释,比较和进化基因组学研究.综述了现有的识别直系同源基因的主要方法,并列举了由此构建的数据库.这些方法可以归纳为三大类,第一类是基于序列相似性的方法,具有识别速度快以及灵敏度高等优点;第二类是基于构建系统发育树的方法,具有准确性高和信息量大等优点;第三类是将上述两种方法结合起来的混合方法,更好地平衡了灵敏性和准确性.最后总结了识别过程所面临的问题.  相似文献   
9.
A novel fluorescence assay system for glucose was developed with thioglycollic acid (TGA)‐capped CdTe quantum dots (QDs) as probes. The luminescence quantum yield of the TGA‐capped CdTe QDs was highly sensitive to H2O2 and pH. In the presence of glucose oxidase, glucose is oxidized to yield, gluconic acid and H2O2. H2O2 and H+ (dissociated from gluconic acid) intensively quenched the fluorescence of QDs. The experimental results showed that the quenched fluorescence was proportional to the glucose concentration within the range of 0.01–5.0 mm under optimized experimental conditions. Compared with most of the existing methods, this newly developed system possesses many advantages, including simplicity, low cost, high flexibility, and good sensitivity. Furthermore, no complicated chemical modification of QDs and enzyme immobilization was needed in this system. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
10.
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