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1.
本文记了分别采自云南高黎贡山的栅蛛科栅蛛属Hahnia 2新种:垭口栅蛛,新种S.yakouensis sp.nov.和肾形栅蛛,新种S.reniformis sp.nov..垭口栅蛛后眼列前曲,交媾腔大,扁圆形,交媾孔1个,位于交媾腔下缘,交媾管粗,呈"人"字形下行分成2支再向两侧扭曲.纳精囊有一肓管斜向上伸出,鉴于上述特征而与Hahnia mridulae Tikader,1970不同.肾形栅蛛交媾孔2个,位于生殖厣腹面中央,纳精囊1对,大,肾形,插入器始于生殖球左下方,鉴于上述特征而与Hahnia xinjiangensis Wang et Liang,1989不同.
Abstract:
The present paper deals with two new species of the genus Hahnia collected from the Gaoligong Mountains Region of Yunnan Province, China: Hahnia yakouensis sp. nov., Hahnia reniformis sp. nov.. 相似文献
2.
中国医科大学博士后科研流动站始建1995年。目前学校设有基础医学、临床医学和生物学3个博士后科研流动站。但由于每年国家财力有限,资助名额很少,在有限条件下建立、健全博士后制度,加强对博士后人员的培养,调动博士后人员的积极性是一项重要的研究课题。 相似文献
3.
遗传物质的发现者之一——麦卡锡 总被引:1,自引:0,他引:1
1944年,3位科学家艾弗里、麦卡锡和麦克劳德在DNA遗传本质方面的发现是20世纪最重要的发现之一,这个发现打开了生物学革命的大门,从而改变了人类对自然界的看法,这项研究还为1953年沃森和克里克DNA双螺旋结构的发现奠定了坚实的基础,但不幸的是3位科学家都未曾荣获诺贝尔奖.通过介绍麦克林·麦卡锡的科学研究,从而对这项发现的基本状况有一个基本的了解. 相似文献
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《植物分类学报》2008,46(3):237-238
One and half centuries ago, Charles Darwin (1859) presented overwhelming evidence and argued that all life on the earth shared common descent, and "from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved". Ernst Haeckel (1886) and several of his contemporaries attempted to trace the pattern of descent among all extant and extinct forms in what Darwin referred to as "the great Tree of Life". Ever since then, systematists and evolutionary biologists have been exploring morphological, cytogenetic, chemical, developmental and molecular characters, and actively developing theories and methods to infer phylogenetic relationships among organisms from these characters. This endeavor has been especially stimulated by the rise of molecular biology and the emergence of computer science over the past 50 years. At the beginning of the 21st century, we are presented with an unprecedented opportunity to reconstruct the entire Tree of Life, and further, to study evolutionary processes and mechanisms in the context of a robust phylogenetic framework. 相似文献
5.
魏曦,字东升,1903年12月25日出生于湖南岳阳一个小职员家庭,父亲任职于邮政局.1914~1921年他在家乡湖滨中学读书,毕业后考入长沙湘雅医学院,学习两年后曾参加北伐军,任第四集团军警卫团三等军医.后退出军队,在长沙广雅中学任教.1928年入设立在上海的中央大学医学院(1932年独立为上海医学院)学习,1933年毕业,获博士学位. 相似文献
6.
高黎贡山北段东西坡种子植物区系的比较研究 总被引:2,自引:0,他引:2
高黎贡山北段的东西坡由于在降雨量和热量分配等方面存在着显著的差异,致使东西坡在植物的种类、组成及区系特征等方面表现出明显的差异.东坡记载野生种子植物152科,580属,1475种及192变种(亚种),西坡记载野生种子植物162科,659属,1804种及186变种(亚种).东西坡种子植物科、属、种的对比分析表明:1)东西坡现代种子植物区系具有相同的历史渊源,但其区系联系减弱了,东西坡区系相似性程度,依科、属、种的顺序依次递减;2)西坡现代种子植物区系比东坡具有更为深刻的热带起源烙印.就科、属、种三个水平来说,东坡的热带成分低于西坡,温带成分高于西坡.许多典型的泛热带大科在西坡比东坡有着更为丰富的种类,其中有些泛热带科分子在东坡缺乏分布,而在西坡找到了合适的驻留之地;3)西坡现代种子植物区系与东喜马拉雅植物区系的联系比东坡紧密,而东坡与高黎贡山以东的区系联系比西坡密切,由于高黎贡山山脉的阻隔,近代植物物种的东西坡交流发生了障碍;4)西坡生态地理环境比东坡更有利于物种的生存、繁衍和分化,它既是古老成分的避难所,又是孕育新生成分的摇篮. 相似文献
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Sequences of the chloroplast ndhF gene and the nuclear ribosomal ITS regions are employed to reconstruct the phylogeny of Prunus (Rosaceae), and evaluate the classification schemes of this genus. The two data sets are congruent in that the genera Prunus s.l. and Maddenia form a monophyletic group, with Maddenia nested within Prunus. However, the ndhF data set is incongruent with the ITS data supporting two major groups within Prunus one consisting of subgenera Laurocerasus (including Pygeum) and Padus as well as the genus Maddenia and another of subgenera Amygdalus, Cerasus, and Prunus. The ITS data, on the other hand, support a clade composed of subgenera Amygdalus and Prunus and Prunus sect. Microcerasus in addition to a paraphyletic grade of subgenera Laurocerasus and Padus (and the genus Maddenia) taxa. In general, the subgeneric classifications of Prunus s.l. are not supported. The ITS and ndhF phylogenies differ mainly in interspecific relationships and the relative position of the Padus/Laurocerasus group. Both ITS and ndhF data sets suggest that the formerly recognized genus Pygeum is polyphyletic and that the distinction of the subgenera Padus and Laurocerasus is not supported. The biogeographic interactions of the temperate and tropical members in the Padus/Laurocera- sus/Maddenia alliance including Pygeum are shown to be highly dynamic and complex. 相似文献
9.
2007年10月13日至11月5日进行敦煌市湿地鸟类调查时,分别在南湖湿地与候鸟自然保护区及党河水库使用Leica apo77高倍望远镜观察到3种水鸟,在以往的文献资料中未见其分布于甘肃的报道,应为甘肃鸟类新纪录。笔者用500mm镜头分别拍下3种水鸟的照片。1.赤颈(Podiceps grisegena)2007年10月13日13:30时,在南湖湿地与候鸟自然保护区的阳关水库(渥洼池)记录到2只赤颈。当时水面上同时有凤头(P.cristatus)、黑颈(P.nigricollis)以及大量鸭类、潜鸭类游禽活动,赤颈体形较凤头小,而又明显比黑颈大。其中一只赤颈的… 相似文献
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Young anthers excised from closed tea flower buds ( Camellia sinensis L.) were stained as fresh tissues with p-dimethylaminocinnamaldehyde reagent to localize flavanols associated with nuclei and chromosomes, apart from those flavanols stored in vacuoles. This staining reagent yields a blue colour for flavanols. In the nonsporogenic somatic cells of developing anthers, flavanols were found to be attached to chromosomes at all mitotic stages. Male meiosis started at a bud size of about 3.5 mm in diameter in pollen mother cells which displayed generally more or less pronounced blue nuclei and cytoplasm. The meiotic divisions from prophase I to telophase II were characterized by blue stained nuclei and chromosomes, but within the cytoplasm there was, if any, a random and very poor reaction for flavanols. Metaphase and telophase of meiotic divisions showed maximally condensed chromosomes staining dark blue. Early in telophase II, the cytoplasm was again stained blue; this faded at late tetrad stage. Flavanols of young mitotic and older non-mitotic anthers were determined using high pressure liquid chromatography--chemical reaction detection (HPLC-CRD). Catechin, epicatechin, B2, and epigallocatechin were minor compounds, whereas epicatechin gallate and epigallocatechin gallate were found in higher amounts. The major flavanol compound of the anthers, epicatechin gallate, exhibited a significant affinity to histone sulphate, as shown by UV-VIS spectroscopic titration. 相似文献
12.
Molecular Reproduction and Development is delighted to announce that editorial board member Mariana F. Wolfner has been elected to the National Academy of Sciences. Here, Dr Wolfner is interviewed by two of her former postdocs. She discusses her path to studying reproduction and her career as a researcher and mentor. 相似文献
13.
Jacques Padawer 《Cell and tissue research》1966,75(1):178-200
Summary Air dried peritoneal fluid and tissue spreads from rat, mouse, hamster, rabbit, guinea pig, cat, chicken, and frog were treated with paraformaldehyde (pCHO) at 80 ° C for 1 hr. Only rat and mouse mast cells fluoresced. In the rat, mast cells fluoresced whether present in vascular or avascular areas of mesentery, in fat depots, or in peritoneal fluid. Photographs were obtained by fluorescence microscopy, the preparations were then stained and the same fields rephotographed in white light. Comparison of the photographs showed that every fluorescent rat mesentery mast cell also stained with acidified toluidine blue and with Astrablau; a few fluorescent cells did not stain with toluidine blue and an occasional cell that did not fluoresce stained with this dye or with Astrablau. Paraformaldehyde depressed somewhat toluidine blue, inhibited strongly Astrablau, and abolished Alcian blue binding. It had no effect on the staining of purified heparin in model experiments.Reserpine administration in the rat did not prevent visualization of mast cells by the pCHO method.These experiments indicate that all rat mast cells contain serotonin, regardless of cell size (age ?) or site and suggest that no massive, cyclic release of this amine occurs either physiologically or in response to reserpine treatment.Some of the experiments for this paper were carried out in the laboratory of Dr. G. Bloom, Department of Cell Research and Genetics, Karolinska Institutet, Stockholm, Sweden, (September and October, 1963). I wish to acknowledge the help and cooperation of the members of his staff, and especially Dr. Martin Ritzén, whose open, warm, efficient and enthusiastic manner enabled me to accomplish much in a relatively short time. Availability of darkroom facilities to pursue much of the work in the laboratories of Dr. W. Bargmann, Anatomisches Institut, Neue Universität, Kiel, Germany and of Dr. R. Robineaux, Hôpital St. Antoine, Paris, is also gratefully acknowledged. Grant support was furnished by the American Heart Association (62 G 118) and NSF (GB-4166) (to the author), by NIH 5 T 1 GM 102, and by the Swedish Medical Research Council (to Prof. B. Uvnäs and Dr. G. Bloom).This paper is dedicated to Dr. Berta Scharrer on the occasion of her 60th birthday. 相似文献
14.
John S. Graham Mark A. Bryant Linda J. Kirkpatrick Donna L. Moltrup 《Biotechnic & histochemistry》1994,69(3):121-126
Multiple skin sections from three nonhuman primates (Macaca mulatta) and three hairless guinea pigs (Cavia porcellus) were stained with 12 different histologic stains to determine whether mast cells could be selectively stained for morphometric analysis using an image analysis system (IAS). Sections were first evaluated with routine light microscopy for mast cell granule staining and the intensity of background staining. Methylene blue-basic fuchsin and Unna's method for mast cells (polychrome methylene blue with differentiation in glycerin-ether) stained mast cell granules more intensely than background in both species. Toluidine blue-stained sections in the guinea pig yielded similar results. Staining of the nuclei of dermal connective tissue was enhanced with the methylene blue-basic fuchsin and toluidine blue stains. These two stains, along with the Unna's stain, were further evaluated on an IAS with and without various interference filters (400.5-700.5 nm wavelengths). In both the methylene blue-basic fuchsin and toluidine blue stained sections, mast cell granules and other cell nuclei were detected together by the IAS. The use of interference filters with these two stains did not distinguish mast cell granules from stained nuclei. Unna's stain was the best of the 12 stains evaluated because mast cell granule staining was strong and background staining was faint. This contrast was further enhanced by interference filters (500.5-539.5 nm) and allowed morphometric measurements of mast cells to be taken on the IAS without background interference. 相似文献
15.
Karel Beneš 《Biologia Plantarum》1964,6(2):142-151
As lipids can be a source of artefacts during intracellular localization of enzymes by cytochemical methodsin situ it was the aim of the present work to obtain orientation data on the distribution of lipids in the meristematic plant cells. The different fixation and object embedding methods examined revealed that it is best to fix the material by some formol fixative and without chroming, to embed it in polyethyleneglycol media. An alcoholic solution of Sudan black was found to be most reliable. In the meristematio cells the cytoplasm is usually stained more intensely than the nucleus. The ground cytoplasm is stained weakly while cytoplasmic particles are stained intensely. In some cases an intense black staining of nuclei, particularly in the prolongation zone, can be achieved. The staining intensity of cell components does not decrease on extracting lipids with pyridine. After extracting the dye from stained cell components a browninsh residual coloration remains. Chromatography of Sudan black revealed in all the samples tested slowly moving spots (blue and violet) and rapidly moving ones (red II, yellow, red I, colourless). 相似文献
16.
Effin T. Graham 《Biotechnic & histochemistry》1997,72(3):119-122
Immature fruit of tomato, Lycopersicon esculentum (Celebrity), was examined to observe the cuticle, its interface with the epidermis, and the general histology of the outer exocarp. Paraffin sections were stained first with Bismarck brown Y. Structures already stained in various hues of brown were stained again with either azure B, aluminum hematoxylin and alcian blue 8GX, or the periodic acid-Schiff (PAS) reaction. Bismarck brown-azure B displayed the cuticle in strong contrast with subjacent tissue; however, nuclei were not easily identified at low magnification. Bismarck brown-hematoxylinalcian blue produced a sharply contrasted combination of yellow cuticle, bright blue cell walls and purple nuclei. Nuclei stained purple with hematoxylin were easily identified at × 100. Bismarck brown-PAS stained the cuticle golden brown and subjacent tissues magenta red. Surprisingly, epidermal cells stained specifically and intensely with PAS while pretreatment with an aldehyde blockade and omission of periodic acid prevented staining of all other tissues. 相似文献
17.
Rybárová S Kluchová D Lovásová K Kocisová M Schmidtová K 《European journal of histochemistry : EJH》2000,44(4):377-384
In this study we have demonstrated the presence of neuropeptide substance P (SP)and nonpeptide neurotransmiter NO (nitric oxide) in the dorsal root ganglia (DRG) of rabbits. NADPH-diaphorase histochemical staining was used for detection of NO and an immunohistochemical method for detection of substance P. A number of DRG cells were stained by SP- and NADPH-d reactions. The presence of SP and NADPH-diaphorase positive cells varied depending upon the spinal level of the DRG. Positively stained neurons were only small and intermediate in size. Cells of large diameter profiles showed no staining. Substance P immunoreactive cells were of brown and dark brown colour, the intensity of NADPH-d staining varied from light to very dark blue. In some DRG cells, there was very significant neuronal co-localization of immunoreactivity for SP and reactivity for NADPH-d. In summary, DRG cells appear to express diaphorase and substance P activity, and some of them show the presence of both neurotransmitters. Recent studies on the participation of NO in the regulation of SP release in the spinal cord suggest, that also in the DRG neurons there may be a close interaction between NO and SP. 相似文献
18.
Summary The sequential application of the avidin-biotinperoxidase complex technique was used to localize multiple tissue antigens on a single free floating section of rat brain. sequential visualization of individual antigens was achieved by the silver-gold-intensified diaminobenzidine (DAB) in the first step, nickel-intensified DAB in the second step, and the DAB alone in the third step of the immunostain procedure. For the demonstration of this method, tyrosine hydroxylase (TH), corticotropin-releasing factor (CRF), and vasopressin (VAS) antisera were used. Sections from the hypothalamic paraventricular nucleus (PVN) of rats pretreated with colchicine were stained. Black TH containing cell bodies were clearly distinguished from blue stained CRF cells and from yellow stained VAS-containing cell bodies in the PVN on the 25–30 m thick vibratome sections. The sequential immunostaining procedure presented here results in superior staining of multiple antigens as compared to that achieved by the sequential application of the peroxidase-antiperoxidase (PAP) technique.Dedicated to Professor Dr. T.H. Schiebler on the occasion of his 65th birthday 相似文献
19.
Summary Sections of guinea-pig hypothalamus stained by various methods have been studied under bright-field and fluorescence microscopy to determine the characteristics of refractile granules originally observed in fixed tissue stained for cholinesterases but also seen in unfixed, unstained material.When sections of fresh tissue or tissue fixed in formaldehyde: Na2SO4 were examined by fluorescence microscopy, the granules emitted with a wave-length between 600 and 620 m. The density and distribution of the granules closely paralleled that of one of the components that stained with the aldehyde-fuchsin and chrome-alum techniques for neurosecretory substance; granules were absent, however, from the area characterized by Herring substance, and from the stained perikarya and beaded axons of the supraoptic and paraventricular nuclei.The granules were most numerous in the median eminence and infundibular nuclei. Their concentration was about average in mature males and in lactating and hypophysectomized females; they were more abundant in late pregnancy and after ovariectomy and were particularly plentiful some weeks after hysterectomy. They were virtually absent from immature males and females.The possible relation of the granules to releasing factors or to vasotocin-like neurosecretory material is discussed.The authors are most grateful to Dr. J. S. Perry who carried out the surgery involved in these experiments. They also wish to express their thanks to Dr. R. B. Heap who, with Dr. Perry, gave invaluable help in planning the experiments and assessing the data; to Mr. S.P. Mann and Dr. D. F. Sharman for advice on the fluorescence technique and to Miss M. Hamon for skilled technical assistance.Publication of the colour pictures was made possible by a generous grant from the Wellcome Foundation; this support is gratefully acknowledged.Thanks are also due to the University of Alberta for a contribution towards the cost of reprints. 相似文献
20.
Cultured endothelial cells derived from bovine calf pulmonary artery were subjected to a variety of fixatives and stained with 1% Alcian blue 8GX at pH 2.59 to 3.26. Within this range of pH, interphase nuclei and especially mitotic figures were (a) strongly stained in cells fixed with 10% formalin (phosphate buffered or unbuffered) or 2.5% buffered glutaraldehyde, (b) weakly stained or unstained in cells fixed in formaldehyde containing divalent cations, and (c) unstained in cells fixed in acetic acid-containing fluids. However, optimal nuclear staining with Alcian blue under the conditions of this study was judged to be achieved after fixation with neutral phosphate buffered 10% formalin. Endothelial cell cytoplasm exhibited a similar fixative-dependent staining. At pH 2.59 the cytoplasm of interphase cells fixed in formaldehyde (containing no divalent cations) or glutaraldehyde remained unstained; however, at higher pH cytoplasmic staining did occur and it increased as pH increased. In contrast, when these latter fixatives were employed the cytoplasm of mitotic cells stained at all pH levels tested. In cultured endothelial cells after appropriate fixation, 1% Alcian blue 8GX (pH 2.59) was found to possess the ability to stain nuclei with a selectivity and intensity that compared favorably to those of the Feulgen reaction of Heidenhain iron hematoxylin but without the latters' length and complexity. Therefore, this procedure may provide a rapid, simple, and selective method for visualizing interphase nuclei or mitotic figures, or both in the majority of cultured cells. 相似文献