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71.
An investigation of gamasid mites on the body surface of small mammals was carried out in Yunnan Province of China from 1990 to 2004. The small mammal hosts were captured from 25 counties which represent five geographical subregions, namely Middle Subregion of Hengduan Mountains, Southern Subregion of Hengduan Mountains, Eastern Plateau Subregion of Yunnan, Western Plateau Subregion of Yunnan and Southern Moun- tainous Subregion of Yunnan. The captured 10 803 small mammal hosts belong to nine families, 29 genera and 52 species in four orders (Rodentia, Insectivora, Scandentia and Lagomorpha). A total of 68 571 gamasid mites were collected from the body surface of the captured small mammal hosts and all the gamasid mites were identified to 10 families, 33 genera and 112 species. This paper lists all the mite species, together with their taxonomic position (genera and families) and their corresponding hosts. Much more mite species were found in the Middle Subregion of Hengduan Mountains than in other geographical subregions. The total individuals of mites and small mammals in the Middle Subregion of Hengduan Mountains are also the most plentiful in the five geographical subregions. Three dominant mite species and three dominant small mammal hosts were determined as the dominant species in the investigated areas of Yunnan Province. The dominant hosts are Rattus flavipectus (which accounts for 34.85% of the total individuals), Apodemus chevrieri (13.43%) and Rattus norvegicus (10.40%) while the dominant gamasid mite species are Laelaps nuttalli (Hirst, 1915) (27.84%), Laelaps echidninus (Berlese, 1887) (18.38%) and Laelaps guizhouensis (Gu et Wang, 1981) (14.79%). The results showed the high species diversity of gamasid mites in Yunnan Province and the uneven distribution feature in different subregions.  相似文献   
72.
Many randomized clinical controlled trials have confirmed the efficacy and safety of calcium dobesilate in treating diabetic retinopathy(DR).This systematic review critically evaluated the evidence that links calcium dobesilate to DR.In this fixed-effects meta-analysis,a total of 221 pertinent English-language articles published between January 1975 and October 2013 were identified.Systematic searches of PUBMED,Springer Link and the Cochrane Clinical Trials Database were conducted using the keywords “diabetic retinopathy” and “calcium dobesilate”.The extracted information included the study design,inclusion and exclusion criteria,setting,sample size,participant mean age,treatment regime,mean change in best corrected visual acuity,laboratory parameters,capillary fragility,intraocular pressure and fundus manifestations based on the findings of fluorescent angiography.The summary statistics indicated that calcium dobesilate was significantly associated with improving retinal microaneurysms(RR: 0.62,95%CI: 0.42?0.90,P=0.01),retinalhemorrhages(RR: 0.39,95% CI: 0.17?0.88,P=0.02); exudates(RR: 0.31,95% CI: 0.12?0.81,P=0.02),reduction of whole blood viscosity(MD: ?0.57 CP,95% CI: ?0.75 to ?0.38,P<0.001),plasma viscosity(MD: ?0.36 CP,95% CI: ?0.63 to ?0.09,P=0.01) and blood cholesterol(MD: ?0.48 mg m L?1,95% CI: ?0.64?0.33,P<0.00001).Intraocular pressure was also significantly reduced(MD: ?5.59 mm Hg,95% CI: ?6.69 to ?4.50,P<0.00001).The results indicate that calcium dobesilate effectively treats DR at the systematic and local ocular levels.  相似文献   
73.
Abstract The karyomorphology of three species in Dipentodon (Dipentodontaceae), Perrottetia (Celastraceae), and Tapiscia (Tapisciaceae), namely Dipentodon sinicus, Perrottetia racemosa, and Tapiscia sinensis, was investigated in the present study. Recent molecular research has discovered close relationships among these three genera, which has led to the establishment of the order Huerteales with Perrottetia being placed in Dipentodontaceae. Herein we report the chromosome numbers of D. sinicus and P. racemosa for the first time, and present their karyotype formulas as 2n = 34 = 22 sm + 12 st (D. sinicus), 2n = 20 = 11 m + 9 sm (P. racemosa), and 2n = 30 = 22 m(2SAT) + 8sm (T. sinensis). Asymmetry of their karyotypes is categorized to be Type 3B in D. sinicus, Type 2A in P. racemosa, and Type 2A in T. sinensis. Each of the species shows special cytological features. Compared with Perrottetia, Dipentodon has a different basic chromosome number, a higher karyotype asymmetry, and different karyomorphology of its interphase nuclei, mitotic prophase, and metaphase. Thus, on the basis of these results, we have reservations regarding the suggestion of placing Dipentodon and Perrottetia together in the family Dipentodontaceae.  相似文献   
74.
75.
条纹斑竹鲨线粒体DNA的研究   总被引:3,自引:0,他引:3  
用6种限制性内切酶分析了4条条纹斑竹鲨的线粒体DNA(mtDNA)。PstⅠ、Hpa Ⅰ、XbaⅠ、EcoRⅠ、EcoRⅤ、BglⅡ在条纹斑竹鲨mtDNA分子上分别具有0至2个切点, mtDNA分子大小为16.6kb,根据单酶和双酶完全酶解片段的大小,构建了条纹斑竹鲨mtDNA 的限制性酶切图谱。 Abstract:Mitochondrial DNA(mtDNA)form 4 samples of Chiloscyllium plagiosum was analyzed by 6 kinds of restriction.The number of cleavage sites were as follow:2 for HpaI,XbaI and EcoRI respectively;1 for BglII and EcoRV respectively;None for PstI.Molecular size of mtDNA was found to be 16.6kb.According to analysis of single and double enzyme cleavage,the map of restriction enzyme was constructed.  相似文献   
76.
从新生儿脐血和成人骨髓中分选出造血干/祖细胞(HSC/HPC),构建成cDNA文库,对其进行大规模表达序列标签(EST)测序,通过生物信息学等手段分析基因表达谱,并进行新基因的全长cDNA克隆。在所测的10512条可分析E ST序列中,有9866条来自脐血CD34+|细胞,其中4697条(47.6%)为已知基因,2603条(26.4%)为已知EST,1415条(14.3%)代表未知EST。在已知基因中,8.2%基因与造血相关,22.7%涉及细胞代谢、结构和迁移,13.0%与细胞分裂和防御相关,26.2%与RNA、蛋白质的合成相关,10.6%和细胞信号传递有关。对一些已知和未知的EST,综合测序、生物信息学等方法,进行全长克隆,已获得23个新基因的全长cDNA。 Abstract:Hematopoietic stem/progenitor cells were isolated from umbilical cord blood and adult bone marrow,and subject to cDNA library construction.The gene expression pattern in CD34+ cells and the identification and cloning of novel genes were performed by sequencing ESTs and analyzing them with the tools of bioinformatics.Among the obtained 10 512 ESTs which could be further analyzed,9,866 were from umbilical cord blood where 4 697(67.6%)were known genes,2 603(26.4%)were known ESTs and 1415(14.3%)represented novel ESTs.Within the identified genes,8.2% was involved in hematopoiesis,22.7% was associated with cell metabolism,structure and mobility,13.0% was linked to cell division and defence,26.2% was related to RNA protein synthesis and 10.6% was related with cell signal transduction.In parallel,we developed an efficient working system combining sequencing,bioinformatics,etc.and obtained 23 full-length cDNAs from both known and novel ESTs identified in this work.  相似文献   
77.
用长PCR方法检测含有较大缺失或插入的DNA大片段   总被引:1,自引:1,他引:0  
选择位于19q13.3上的人类肌张力蛋白激酶基因(myotonin protein kina se gene,MT-PK)为靶基因(基因全长为14kb),以G+C含量较高且含有1kb缺失或插入,由基因第8内含子中的Alu±1kb的5'端至第15外显子3'非编码区中的CTG重复序列3'端,即两者间的距离为5.3kb的DNA片段为待扩增靶序列,通过优化DNA聚合酶的组合和反应缓冲体系,点考查了含有Alu-1k b和Alu+1kb缺失或插入的MT-PK等位基因片段共扩增的长PCR方法。本方法可有效地同步扩增6.5kb和5.5kb两个等位基因片段,对6.5kb和5.5kb纯合等 位片段则达到了更有效的扩增。  相似文献   
78.
关于回交世代方差中加性×显性分量的讨论A   总被引:1,自引:0,他引:1  
当两系统存在k对基因差异,P1中增效基因为k-k’对,减效基因k’对时,两纯系杂交回交群体遗传方差加性×显性分量的数学式为F=(k-k’)∑(i=1)d1h1-k’∑(i=1) d1h1.。F的大小决定于显性齐性和基因分散的程度。因此在一般情况下,F的遗传含义是混杂不清的。只有基因完全相联时F=k∑(i=1)d1h1,与Mather 和Jinks 的推导结果一致,这时F反映显性齐性程度。Abstract: Assuming kpairs of different genes between two pure parental lines (P1 and P2), k-k’ pairs of increasing genes and k’ pairs of deereasing genes in P1,the comoponent of additive×dominance in the genetic variance of the backcross generation is represented as F=(k-k’)∑(i=1)d1h1-k’∑(i=1) d1h1.The component F is determined by both the consistency of dominance and the dispersion of genes. In genetral, the genetic implication of the component F is complexity.Only under the situation of complete associates of genes F=k∑(i=1)d1h1,which agrees with the result by Mather and Jinks. In such case, F illustrates the consistency of dominance.  相似文献   
79.
魏刚徐宁  李德俊  WEI  Gang  XU  Ning  LI  De  JUN吴    WU  Min 《遗传》1994,16(1):23-15
中亚林蛙(Rana asiatica)的核型为2n=26,NF=52。第2号染色体短臂有一条近端着丝粒区C带。第10号染色体长臂上有一对标准NORs。本文认为,田野林蛙(Rana arvalis)起源于欧洲,是欧洲林蛙群与亚洲2n=24的林蛙群间的过渡种类。The diploid number of Rana asiatica is 2n=26, NF=52,with an acrocetric C-band on 2p and a pair of standard NORs on 10q. The paper holds that Rana arvalis,originated in Europe, is a interim species between Rana group in Europe and Rana group in Asia with 2n=24.  相似文献   
80.
向齐君  吴兰佩XIANG  Qi-Jun  WU  Lan-Pei 《遗传》1994,16(1):35-37
在液体培养基上用0.05%的秋水仙素处理小麦-黑麦杂种幼穗愈伤组织,含秋水仙素的培养基采用两种方法灭菌:(1)秋水仙素与培养基成分混合在一起用灭菌锅灭菌。处理愈伤后愈伤组织无伤害迹象,推测可能是灭菌过程中秋水仙素浓度降低所致;再生植株的育性得到有效的恢复,48.1%的穗子结实,5.2%的穗子结实率达到34.8%;(2)秋水仙素经超滤灭菌后,在常温下与灭过菌的培养基成分混和,处理愈伤后愈伤组织伤害严重,几乎不能分化苗。  相似文献   
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