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中国水螅属一新种(螅形目,水螅科) 总被引:2,自引:2,他引:0
记述采自北京地区水螅属1新种:北京水螅Hydra beijingensis sp.nov.。新种的主要鉴别特征是出现体部与柄的分化;钩刺丝囊内刺丝缠绕具有2种形态:大部分钩刺丝囊(占2/3左右)内顶端基部刺丝呈4~5圈横向弹簧状缠绕,而占所观察刺丝囊总数1/3左右的囊内刺丝为不规则缠绕和纵向缠绕。标本保存在哈尔滨师范大学生命与环境科学学院生物学系无脊椎动物研究室。 相似文献
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中国水螅属一新种(水螅纲,水螅科) 总被引:1,自引:0,他引:1
报道采自广东省肇庆市的淡水水螅1新种,多形水螅Hydra polymorphus sp.nov.,研究标本均来自1只水螅的单系繁殖群体,测量数据经生物统计学处理。新种的钩刺丝囊外形及内部刺丝盘旋均有多种形态,故新种名以此命名。所有研究标本保存于深圳大学生命科学学院。 相似文献
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中国水螅属一新种(螅形目,水螅科) 总被引:1,自引:0,他引:1
记述水螅科水螅属1新种:哈尔滨水螅Hydra harbinensis sp.nov.。本种与其它已报告的雌雄同体水螅有明显区别,只与美洲的海曼水螅较为相似,但也有不同,其与海曼水螅的区别为:生活于静水,能直立并可横向附着生活,实验室培养用储放的自来水可正常生活及生殖。粘刺丝囊小型。胚鞘的鞘膜表面有网格,每根圆锥形的棘刺发自每一网格中央,棘刺无结节,不分叉。精巢数目为2~6个,卵为4~6个。模式标本保存于哈尔滨师范大学生命与环境科学学院生物学系无脊椎动物研究室。 相似文献
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五种水螅基因组DNA的RAPD多态性研究 总被引:2,自引:1,他引:1
利用RAPD技术对水螅科2属5种水螅进行了基因组DNA多态性研究.80个随机引物筛选出18个引物,共扩增出303个清晰稳定的DNA片段,分子量在0.3~3.0kb之间.以UPGMA聚类法构建树状图,阐明水螅属种的分类关系:大庆水螅Hydra daqingensis、北京水螅H.beijingensis和强壮水螅H.robusta 3种分成两组并聚在一起;不同属的漠河水螅H.mohensis和绿水螅Chlorohydra sp.聚为一支;由此2属5种水螅分为两个支系. 相似文献
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腔肠动物具有其他动物所没有的特殊的刺细胞(cnidocyst),因而旧称刺胞动物(Cnidaria)。刺细胞来源于未分化的间细胞,发育过程很复杂(图1见封二,下同)。成熟的刺细胞一般呈椭圆形,端部的一侧具一小针状的刺针(cnidocil),细胞核位于细胞的基部。刺细胞中含有一囊状的细胞器称刺丝囊(nematocyst)(图2)。在腔肠动物中已识别出的刺丝囊有20余种。Weill(1923)研究了 相似文献
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中国水螅属一新种(水螅虫纲:螅形目) 总被引:4,自引:3,他引:1
报道采自黑龙江省漠河地区北极村水螅1新种,即漠河水螅Hydra mohensis sp.nov.,模式标本保存于哈尔滨师范大学生物学系无脊椎动物教学研究室。 相似文献
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水螅和涡虫的立体生态养殖 总被引:3,自引:1,他引:2
水螅(Hydra)和三角头涡虫(Dugesia)是动物学实验与研究的重要材料,但由于河流污染和生态环境的破坏,野外已不易采到。人们曾摸索了许多单纯饲养水螅和涡虫的方法,但由于投饵和经常换水等问题,工作量较大而不能长期养殖。我们在研究野外水螅和涡虫共同栖息的小生境的基础上,结合前人的一些经验,于1994年开始在室内进行了水螅和涡虫的立体生态混养实验,获得了成功。1 饲养缸的制作和安放用0.5cm厚的普通玻璃制作长55cm、宽33cm、高25cm和长35cm、宽35cm、高15cm的玻璃缸各1个,前… 相似文献
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Profiles of SARS-CoV-2 RNA and Antibodies in Inpatients with COVID-19 not Related with Clinical Manifestation: A Single Centre Study 下载免费PDF全文
Zhao Li Gao Ruqin Lu Roujian Wang Huijuan Deng Yao Niu Peihua Jiang Fachun Huang Baoying Liang Jiwei Jia Jing Zhang Feng Wang Wenling Wu Guizhen Tan Wenjie 《中国病毒学》2021,36(5):1088-1092
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera. 相似文献
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted. 相似文献
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Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme
responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare
the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show
that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by
distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of
demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least
one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of
the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable
potent antiproliferative synthetic drugs. 相似文献
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正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases 相似文献