全文获取类型
收费全文 | 271篇 |
免费 | 7篇 |
国内免费 | 8篇 |
专业分类
286篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 7篇 |
2020年 | 7篇 |
2019年 | 4篇 |
2018年 | 1篇 |
2017年 | 7篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2014年 | 13篇 |
2013年 | 16篇 |
2012年 | 11篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 22篇 |
2008年 | 11篇 |
2007年 | 9篇 |
2006年 | 13篇 |
2005年 | 9篇 |
2004年 | 9篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 14篇 |
2000年 | 15篇 |
1999年 | 7篇 |
1998年 | 7篇 |
1997年 | 10篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 13篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
排序方式: 共有286条查询结果,搜索用时 0 毫秒
121.
Cytogenetic characteristics of the Caspian Pond Turtle, Mauremys caspica, in Golestan and Mazandaran provinces in the northern part of Iran show that the chromosome number is 2n?=?52 and the arm number NF?=?78. The karyotype consisted of 9 metacentric (M), 1 submetacentric (SM), 3 subtelocentric (ST) and 13 telocentric (T) chromosome pairs. The Centromeric Index ranges from 11.79 to 45.68, the arm ratio between 1.18 and 7.47, the relative length between 1.60 and 11.46, and the length variation between 1.05 and 7.48. Average total length of the chromosomes is 65.27 µm. The largest chromosome in this species is a pair of the metacentric chromosome. Location of NOR was determined on chromosome pair no. 10. 相似文献
122.
《Biotechnic & histochemistry》2013,88(2):94-97
AbstractIn just half a century since the human diploid chromosome number was correctly identified as 46, there has been a rapid expansion in our understanding of both the genetic foundation of normal human development and the development of various constitutional and acquired abnormalities. The ability to detect numerical and structural chromosomal abnormalities was made possible by the Giemsa stain. Despite the recent advent of powerful molecular-based cytogenetic techniques (e.g., fluorescence in situ hybridization, array-based comparative genomic hybridization), Giemsa-based chromosomal banding and staining techniques retain their crucial role in cytogenetics. 相似文献
123.
Makroo RN Chowdhry M Mishra M Srivastava P Fauzdar A 《Indian journal of human genetics》2011,17(3):238-240
We report a case of an elderly 68-year-old male who presented in our hospital with chief complaints of petechial rashes and ecchymosis over extremities and bleeding from the oral cavity since 3-4 days prior to hospitalization. He saw a physician before coming to our hospital and received one dose of IV methylprednisolone and oral wysolone. He had come to our hospital for further management. Bone marrow karyotyping was done and chromosomal analysis revealed two cell lines. Eighty percent of the cells analyzed revealed apparently normal male karyotype. However, 20% cells analyzed revealed a total of 184 chromosomes, suggesting octaploidy. 相似文献
124.
Di Bucchianico S Giardi MF De Marco P Ottaviano L Botti D 《Journal of molecular recognition : JMR》2011,24(4):608-618
The Marek's disease virus (MDV) integration may induce a novel organization of chromatin architecture with a modified genetic expression. In our opinion it is worthwhile trying to relate cytogenetic stability to functional modifications. Recently, atomic force microscopy technique was applied to study the structure of chromosomes at a nanoscale level. This high resolution allows to investigate the different structure of chromatin in order to study cytogenetic stability and chromosome aberrations due to MDV insertion. In this paper data are presented indicating a duplication [78,WZ,dup(1p)(p22-p23)] and a deletion [78,WZ cht del(3)(q2.10)] of Chromosomes 1 and 3 relatively. Relationships between GTG (G-bands by Trypsin using Giemsa) bands and the topography of chromosomes are also discussed, naming them Topographic Banding. The architecture of chromosomes observed by AFM can be related to the data obtained with classic banding techniques thus overcoming the optical resolution limits. The presence of chromatin bridges between sister chromatids at most of the heterochromatic regions is also evidenced. Besides, we present different studies of the longitudinal and transversal symmetry of the hetero and euchromatic regions to clearly demonstrate a different underlying architecture of these regions. It is indeed evident that the heterochromatic bands are more symmetrical than euchromatic bands. 相似文献
125.
Blanco DR Bertollo LA Lui RL Vicari MR Margarido VP Artoni RF Moreira-Filho O 《Journal of fish biology》2012,81(1):351-357
This study presents an adaptation of current methodologies for preparing mitotic chromosomes from fishes, optimized for use in the field. The high-quality preparations obtained using this modified methodology is suitable for subsequent chromosomal analysis. Importantly, this method is particularly useful when specimen collection sites are far from research laboratories or when researchers are working with highly sensitive species that do not survive long outside of their natural habitats. 相似文献
126.
Nancy Shui-Fong Ma Rolando Aquino William E. Collins 《American journal of primatology》1985,9(4):333-341
The observation of remarkable karyotypic variation in owl monkeys (Aotus trivirgatus) stimulated us to study the chromosomal evolution of this New World genus. As an extension of this project, we examined the chromosome complement of a “phenotype-B” Aotus population from Peru. In addition to karyotype V(2n = 46), two new karyotypes with diploid numbers of 47 and 48 were identified. A G-band comparison of these karyotypes indicated that the chromosome number polymorphism in these Peruvian owl monkeys resulted from a single fusion or fission event involving a single metacentric and two acrocentric chromosome pairs. This mechanism is also known to be responsible for the chromosome number polymorphism in at least two other populations of phenotype B Aotus, one from Colombia and the other from Panama. 相似文献
127.
The resting metabolic rate of passerines is shown to be negatively correlated with genome size when body mass is held constant (r = –0.75, P < 0.01). This finding extends previous conclusion for mammals to this bird order. The result holds when higher taxonomic levels are used instead of the species (for genera, r = –0.76, P < 0.03; for families, r = –0.991, P < 0.01) as well as when the independent contrasts derived from the resolved phylogeny are used instead of the taxa (r = –0.73, P < 0.02), with the evolutionarily older contrasts being more strongly correlated (for the contrasts older than 30 million yr, r = –0.998, P < 0.002). The concept of evolutionary characters consolidation (ECC), previously formulated for mammals, is tested with special reference to the error fraction in the total character variance. In this test, the ECC for the nucleotypic effect cannot be proven for mammals as a whole class, but it holds for the two separate orders tested, rodents and passerine birds. An upper taxonomic limit for the ECC is suggested. 相似文献
128.
129.
荧光原位杂交技术在植物细胞遗传学和绘制基因图谱中的应用现状与展望 总被引:7,自引:1,他引:6
荧光原位杂交是在分子水平上检测外源染色质的一种有效方法。其探针主要有染色体重复序列、总基因组DNA、寡单拷贝序列和染色体涂色集中等,该技术在研究植物细胞遗传学、基因扩增、基因作图及植物进化和亲缘关系的鉴定上已广泛应用。简要概述了荧光原位杂交技术在植物细胞遗传学和绘制基因图谱中的应用现状与展望。 相似文献
130.