全文获取类型
收费全文 | 971篇 |
免费 | 68篇 |
国内免费 | 3篇 |
出版年
2023年 | 9篇 |
2022年 | 19篇 |
2021年 | 30篇 |
2020年 | 20篇 |
2019年 | 22篇 |
2018年 | 25篇 |
2017年 | 21篇 |
2016年 | 31篇 |
2015年 | 39篇 |
2014年 | 50篇 |
2013年 | 61篇 |
2012年 | 64篇 |
2011年 | 63篇 |
2010年 | 48篇 |
2009年 | 43篇 |
2008年 | 48篇 |
2007年 | 48篇 |
2006年 | 30篇 |
2005年 | 30篇 |
2004年 | 32篇 |
2003年 | 33篇 |
2002年 | 20篇 |
2001年 | 13篇 |
2000年 | 18篇 |
1999年 | 11篇 |
1998年 | 12篇 |
1997年 | 7篇 |
1996年 | 6篇 |
1995年 | 7篇 |
1994年 | 11篇 |
1993年 | 6篇 |
1992年 | 13篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1989年 | 9篇 |
1988年 | 9篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 16篇 |
1984年 | 6篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1974年 | 7篇 |
1972年 | 5篇 |
1967年 | 5篇 |
1966年 | 5篇 |
排序方式: 共有1042条查询结果,搜索用时 31 毫秒
1.
2.
Liang Zhong Chen Simon Easteal Philip G. Board Kim M. Summers Kuldeep K. Bhatia Robert L. Kirk 《Human genetics》1990,85(1):89-97
Summary We have determined the various haplotypic combinations between alleles as well as restriction fragment length polymorphisms of two linked genetic markers, albumin and vitamin D-binding protein or group-specific component, in a number of Asian-Pacific populations. Using the partial maximum likelihood method, we constructed a phylogenetic network from the haplotype frequencies to assess relationships among the populations sampled. No systematic linkage disequilibrium was detected between most of the combinations, suggesting a lack of operation of any selection pressure at the two loci. The phylogenetic analysis confirmed the known interrelationships among various populations in the Asian-Pacific region. The Australian aborigines clustered closely with the non-Austronesian-speaking highlanders from Papua New Guinea, as expected. Similarly, the Austronesian-speaking Polynesians, Micronesians, and the Southeast Asians branched off together as a separate group. The position of the Austronesian-speaking Tolais from New Britain with respect to other populations from the Southwest Pacific was anomalous. The Tolais revealed a strong affinity with the Australian aborigines, which is inexplicable. The populations from China formed a tight cluster with other populations from the Asian-Pacific region. Genetic interrelationships of these populations with the white Australians were remote, which is in accordance with the known affinities of various human racial groups. 相似文献
3.
4.
R Dahiya B Boyle B C Goldberg W H Yoon B Konety K Chen T S Yen W Blumenfeld P Narayan 《Biochimie et biologie cellulaire》1992,70(7):548-554
Metastatic variants of human prostatic adenocarcinoma cell lines (DU-145, LNCaP, and ND-1) were studied by using soft agar colony forming efficiency, nude mice tumorigenicity, in vitro invasion assay, and type IV collagenase assay. The DU-145 and ND-1 cell line showed higher metastatic potential than LNCaP. Lipids from DU-145, ND-1, and LNCaP cells were extracted and analyzed by thin-layer chromatography and gas-liquid chromatography. The major lipids were phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, fatty acids, and cholesterol. The sphingomyelin level was significantly higher in highly metastatic cells (DU-145 and ND-1) compared with the lower metastatic variant (LNCaP). The increase in the synthetic pathway and decrease in degradation pathway of sphingomyelin in microsomal fractions was sufficient to account for the measured increase in sphingomyelin in DU-145 cells compared with LNCaP cells. The major fatty acids of these lipids were palmitic (16:0), stearic (18:0), oelic (18:1), and arachidonic acid (20:4). The arachidonic acid level was significantly decreased in DU-145 and ND-1 compared with LNCaP cells. Electron microscopic studies showed no significant changes in the morphology of DU-145, ND-1, and LNCaP cells. The results of these investigations demonstrate for the first time that sphingomyelin and arachidonic acid contents are different in high and low metastatic variants of human prostatic adenocarcinoma cell lines. 相似文献
5.
The present communication deals with a histological study of the pituitary gland of the teleost fish Mugil cephalus , found in the estuarine waters of Cochin area. Six different cell types were identified in the pituitary gland on the basis of their grouping, distribution and staining properties. The prolactin and the TSH cells (thyroid stimulating hormone producing cells or thyrotrops) were identified in the rostral pars distalis and the ACTH cells (adrenocorticotropic hormone producing cells or corticotrops) in the interphase between the neurohypophysis and the rostral pars distalis. The STH cells (somatotropic hormone producing cells or somatotrops) and the gonadotropic cells were distinguished in the proximal pars distalis and the MSH cells (melanin stimulating hormone producing cells or melanotrops) in the pars intermedia. 相似文献
6.
7.
Stem segments of adult plants of Ficus religiosa L. cultured on MS medium containing 1.0 mg/l 2,4-D produced callus. Shoots were regenerated when the induced calli were transferred to medium supplemented with 0.05 to 2.0 mg/l BAP. Callus derived shoots produced roots and developed into plantlets when transferred to medium supplemented with 1.0 mg/l NAA.Abbreviations MS
Murashige and Skoog (1962)
- BAP
6-benzylaminopurine
- NAA
naphthaleneacetic acid
- 2,4-D
2,4-dichlorophenoxyacetic acid 相似文献
8.
9.
10.