全文获取类型
收费全文 | 7268篇 |
免费 | 423篇 |
国内免费 | 1篇 |
出版年
2022年 | 30篇 |
2021年 | 81篇 |
2020年 | 46篇 |
2019年 | 60篇 |
2018年 | 79篇 |
2017年 | 84篇 |
2016年 | 130篇 |
2015年 | 201篇 |
2014年 | 242篇 |
2013年 | 455篇 |
2012年 | 345篇 |
2011年 | 372篇 |
2010年 | 232篇 |
2009年 | 223篇 |
2008年 | 372篇 |
2007年 | 366篇 |
2006年 | 378篇 |
2005年 | 372篇 |
2004年 | 350篇 |
2003年 | 342篇 |
2002年 | 343篇 |
2001年 | 232篇 |
2000年 | 236篇 |
1999年 | 199篇 |
1998年 | 90篇 |
1997年 | 84篇 |
1996年 | 66篇 |
1995年 | 72篇 |
1994年 | 60篇 |
1993年 | 79篇 |
1992年 | 147篇 |
1991年 | 112篇 |
1990年 | 116篇 |
1989年 | 131篇 |
1988年 | 97篇 |
1987年 | 108篇 |
1986年 | 85篇 |
1985年 | 78篇 |
1984年 | 72篇 |
1983年 | 55篇 |
1982年 | 38篇 |
1981年 | 42篇 |
1980年 | 36篇 |
1979年 | 55篇 |
1978年 | 29篇 |
1977年 | 39篇 |
1976年 | 24篇 |
1975年 | 22篇 |
1974年 | 27篇 |
1973年 | 23篇 |
排序方式: 共有7692条查询结果,搜索用时 15 毫秒
81.
Yasuro Yoshimura Takayuki Kawano Mitsuru Kuroi Masaaki Morishita Masahiko Mori Kensaku Kawakatsu 《Histochemistry and cell biology》1970,22(4):337-346
Summary Analysis of lactate and malate dehydrogenase zymograms of rodent salivary glands showed species and organ specific patterns.Lactate dehydrogenase isoenzyme patterns occupied the middle positions in relation to those of skeletal and heart muscle. Activities of the major salivary glands were in the order submaxillary gland>parotid>sublingual gland. Zymogram of the mouse and rat showed LDH4 and LDH5 high activity patterns, while that of the rabbit was the fast moving active one. Hamster salivary gland exhibited a neutral type of the former and the latter.Malate dehydrogenase isoenzyme exhibited very similar patterns for the mouse, rat and hamster. Malate dehydrogenase zymogram of rabbit showed 3 active bands, which was different from the other rodents. 相似文献
82.
83.
84.
85.
86.
87.
Establishment of five human myeloma cell lines 总被引:3,自引:0,他引:3
Masayoshi Namba Takemi Ohtsuki Masaharu Mori Atsushi Togawa Hideho Wada Takashi Sugihara Yoshihito Yawata Tetsuo Kimoto 《In vitro cellular & developmental biology. Plant》1989,25(8):723-729
Summary Five human myeloma cell lines, KMM-1, KMS-5, KMS-11, KMS-12- PE, and KMS-12-BM, have been established at Kawasaki Medical
School since 1980. As the KMS-12-PE and KMS-12-BM lines were obtained from the same patient, these five cell lines have been
derived from four patients with multiple myeloma. The five myeloma cell lines are stably growing at present in RPMI 1640 medium
supplemented with 10% fetal bovine serum. They can also grow in a defined culture medium without serum. That these cell lines
were, human myeloma cells was confirmed by the following findings. Ultranstructually, all five cell lines showed features
characteristic of plasma cells. KMM-1 and KMS-11 cells secreted lambda and kappa chains into the culture medium, respectively,
but the other cell lines produced no immunoglobulins. KMM-1 expressed cytoplasmic lambda antigen, KMS-5 showed cytoplasmic
delta, and KMS-11 expressed surface kappa, whereas KMS-12-PE and KMS-12-BM cells showed no surface or cytoplasmic immunoglobulins.
Regarding reaction with a monoclonal plasma cell antibody (PCA-1), four of the five lines were positive, the exception being
KMS-5. Another monoclonal antibody (CD38), which also recognizes plasma cells, reponded to KMM-1, KMS-12-PE, and KSM-12-BM.
KMS-5 cells expressed acute lymphoblastic leukemia antigens (CALLA). These data suggest that such lines as KMM-1, KMS-11,
KMS-12-PE, and KMS-12-BM represent later stages of B-cell differentiation, and that KMS-5 represents a relatively early stage
of B-cell differentiation. All the cell lines lacked Epstein-Barr virus nuclear antigen, showed abnormal karyotypes of human
origin, and differed from each other in the isozyme patterns examined. Only KMS-5 was tumorigenic when transplanted subcutaneously
into nude mice. 相似文献
88.
Y Mori S Seino K Takeda I L Flink Y Murata G I Bell S Refetoff 《Molecular endocrinology (Baltimore, Md.)》1989,3(3):575-579
T4-binding globulin (TBG), a 54-kilodalton glycoprotein, is the major thyroid hormone transport protein in man. The exact nature of the mutations causing X chromosome-linked TBG deficiency, which affect about 1 in 2,500 newborn males, is unknown. Here we report the sequence of a unique variant TBG (TBG-Gary) encoding a protein with severely impaired T4 binding as well as decreased stability at 37 C, resulting in its rapid in vivo denaturation. A single nucleotide substitution in the codon for residue 96 of the mature protein replaces isoleucine with asparagine; this replacement creates an additional site for N-linked glycosylation. The anodal shift of TBG-Gary on isoelectric focusing gel electrophoresis suggests that this new site is likely glycosylated. Since glycosylated is required for TBG to assume its correct tertiary structure, but is not subsequently necessary for maintenance of the biological properties or stability of the molecule, we believe that the likely presence of additional carbohydrate probably affects a higher order structure of the molecule and is thus responsible for the reduced stability and hormone binding activity of TBG-Gary (TBGASN-96). 相似文献
89.
90.
One hundred and eighteen algal isolates comprising seven classes were obtained from a range of sites from polluted rivers running through Cu or Zn mining regions, and from unpolluted rivers. All the isolates were tested for photosynthetic activity when exposed to Cu, Cd or Zn. The tolerance levels of Bacillariophyceae, Charophyceae, Cyanophyceae and Chlorophyceae to Cu showed significant positive correlations with Cu concentrations in the field. However the distribution of metal sensitivities of the algae from the sites with the same metal concentration was broad. Both Bacillariophyceae and Charophyceae had a number of strains whose sensitivity to Cu differed more widely in relation to Cu levels in the environment than Cyanophyceae and Chlorophyceae. Cyanophyceae were sensitive to all three metals, whether or not isolates were obtained from polluted sites, whereas Chlorophyceae tended to have high tolerance even in isolates from unpolluted sites. For Cd and Zn the correlation between tolerance levels and concentrations in the field was not so clear as for Cu. The occurrence of Cu tolerance was shown in 4 diatom species and one Charophyceae, whereas metal resistance occurred in some Chlorophyceae. Cu-tolerant isolates tended also to be Zn-tolerant in Bacillariophyceae, and Cd-resistant isolates tended also to be Zn-resistant in Chlorophyceae. 相似文献