全文获取类型
收费全文 | 3338篇 |
免费 | 246篇 |
国内免费 | 2篇 |
出版年
2022年 | 9篇 |
2021年 | 51篇 |
2020年 | 20篇 |
2019年 | 21篇 |
2018年 | 52篇 |
2017年 | 35篇 |
2016年 | 63篇 |
2015年 | 94篇 |
2014年 | 101篇 |
2013年 | 204篇 |
2012年 | 158篇 |
2011年 | 174篇 |
2010年 | 101篇 |
2009年 | 105篇 |
2008年 | 168篇 |
2007年 | 172篇 |
2006年 | 186篇 |
2005年 | 166篇 |
2004年 | 172篇 |
2003年 | 162篇 |
2002年 | 160篇 |
2001年 | 97篇 |
2000年 | 117篇 |
1999年 | 83篇 |
1998年 | 62篇 |
1997年 | 44篇 |
1996年 | 39篇 |
1995年 | 38篇 |
1994年 | 36篇 |
1993年 | 32篇 |
1992年 | 41篇 |
1991年 | 57篇 |
1990年 | 57篇 |
1989年 | 41篇 |
1988年 | 51篇 |
1987年 | 48篇 |
1986年 | 40篇 |
1985年 | 48篇 |
1984年 | 23篇 |
1983年 | 27篇 |
1982年 | 23篇 |
1981年 | 22篇 |
1980年 | 17篇 |
1979年 | 18篇 |
1978年 | 17篇 |
1977年 | 25篇 |
1976年 | 19篇 |
1974年 | 12篇 |
1973年 | 18篇 |
1971年 | 10篇 |
排序方式: 共有3586条查询结果,搜索用时 15 毫秒
121.
Isolation and characterization of a cDNA clone encoding rat nucleoside diphosphate kinase 总被引:9,自引:0,他引:9
N Kimura N Shimada K Nomura K Watanabe 《The Journal of biological chemistry》1990,265(26):15744-15749
A cDNA clone for cytosolic nucleoside diphosphate (NDP) kinase was isolated from a cDNA library of rat skeletal muscle using synthetic oligonucleotides as probes. The clone constitutes a 621-base pair cDNA sequence including the 456-base pair coding region and 137-base pair 3'-untranslated one with polyadenylation site. The complete primary structure of NDP kinase was deduced from the coding sequence. An NH2-terminal amino acid sequence analysis suggested that the translated enzyme protein suffered proteolytic cleavage followed by modification at the alpha-NH2 group of the newly produced NH2-terminal amino acid residue. Taking this into account, it was tentatively concluded that the mature NDP kinase consists of 147 amino acid residues with a molecular weight of 16,724. Northern blot hybridization analysis showed that NDP kinase mRNA could be detected in total RNA fractions of brain, spleen, heart, lung, liver, kidney, testis as well as skeletal muscle, and that there was no difference in the size of mRNAs from these tissues. Tissue distribution of the mRNA nearly paralleled those of protein moiety and activity of the enzyme. 相似文献
122.
H Kumano T Kuboki R Tawara T Sasaki S Nomura H Suematsu E Ogata 《Endocrinologia japonica》1990,37(4):583-589
To determine the interrelationship between muscle dysfunction and a low T3 state, both seen in anorexia nervosa, we studied the relationship between the degree of muscle involvement, as assessed by the circulating concentration of the three muscle indicators (CPK, GOT and LDH), and serum T3 in thirty-three patients when they were admitted to the hospital. We also studied the malnutritional state, as assessed by their body weight or serum GH, serum potassium and the degree of hyperactivity exhibited. Additionally, another twelve patients were studied in order to explore the mounding phenomenon which is typically elicited in hypothyroidism. The logarithms of serum CPK and GOT correlated only with the serum T3 concentration (r = -0.35, p less than 0.05; r = -0.41, p less than 0.05; respectively). The logarithm of serum LDH highly correlated with serum T3, the percentage of ideal body weight, and the logarithm of serum GH (r = -0.55, p less than 0.01; r = -0.66, p less than 0.001; r = 0.43, p less than 0.05; respectively). The mounding phenomenon was elicited in ten out of twelve patients. In conclusion, it was implied that a low T3 state was associated with an increase in serum muscle indicators and thus with muscle dysfunction encountered in anorexia nervosa. 相似文献
123.
Tests for calluses rich in tropane alkaloids were made with newly induced calluses of Atropa belladonna, Datura stramonium and Hyoscyamus niger. Only calluses of H. niger gave an alkaloid-positive test.A Hyoscyamus cell line had the highest total alkaloid content of all the calluses screened by the cell-squash alkaloid assay. Both hyoscyamine and scopolamine were identified in the cultured cells of this line by TLC, GLC and GC-MS.Abbreviations NAA
1-Naphthaleneacetic acid
- BA
Benzyladenine
- BSA
N,O-Bis(trimethylsilyl) acetamide 相似文献
124.
Cartilage-derived factor (CDF) : II. Somatomedin-like action on cultured chondrocytes 总被引:2,自引:0,他引:2
Yukio Kato Yoshio Nomura Mitsuko Tsuji Hiroaki Ohmae Masahiko Kinoshita Shinji Hamamoto Fujio Suzuki 《Experimental cell research》1981,132(2):339-347
Previously, we showed that fetal bovine cartilage contains a polypeptide that stimulates the incorporation of [35S]sulfate into proteoglycans synthesized by rat and rabbit costal chondrocytes in culture. In this paper, we report that the cartilage-derived factor (CDF) increases not only [35S]sulfate incorporation but also [3H]thymidine incorporation into rabbit chondrocytes in monolayer culture. The dose-response curve of CDF stimulation of DNA synthesis was similar in profile to that of CDF stimulation of proteoglycan synthesis. In addition, CDF markedly enhanced [3H]uridine incorporation into rabbit chondrocytes and significantly enhanced [3H]serine incorporation into total protein. These findings indicate that fetal bovine cartilage contains a factor that shows somatomedin-like activity in monolayer cultures of rabbit chondrocytes. 相似文献
125.
Deletion analysis of the expression of rRNA genes and associated tRNA genes carried by a lambda transducing bacteriophage.
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Transducing phage lambdailv5 carries genes for rRNA's, spacer tRNA's (tRNA1 Ile and tRNA1B Ala), and two other tRNA's (TRNA1 Asp and tRNA Trp). We have isolated a mutant of lambdailv5, lambdailv5su7, which carries an amber suppressor mutation in the tRNA Trp gene. A series of deletion mutants were isolated from the lambdailv5su7 phage. Genetic and biochemical analyses of these deletion mutants have confirmed our previous conclusion (E. A. Morgan, T. Ikemura, L. Lindahl, A. M. Fallon, and M. Nomura, Cell 13:335--344, 1978) that the genes for tRNA1 Asp and tRNA Trp located at the distal end of the rRNA operon (rrnC) are cotranscribed with other rRNA genes in that operon. In addition, these deletions were used to define roughly the physical location of the promoter(s) of the rRNA operon carried by the lambdailv5su7 transducing phage. 相似文献
126.
Tunicamycin-resistant mutants and chromosomal locations of mutational sites in Bacillus subtilis.
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The types of tunicamycin-resistant mutants of Bacillus subtilis were analyzed, and their mutational sites on the chromosome were mapped. A type 1 mutation that simultaneously expressed hyperproductivity of extracellular alpha-amylase was located close to amy E. Type 2 mutations were near aroI. 相似文献
127.
128.
129.
130.
The structural genes for six ribosomal proteins (r-proteins) located in the str-spc region around 64 minutes on the Escherichia coli chromosome have been mapped physically with respect to each other and the neighboring genes aroE and trkA. The genes code for the 30 S r-proteins S4 (ram), S5 (spc), S8, S11, S13 and S14. Furthermore, regions coding for unidentified 50 S r-proteins have been indicated.The mapping was performed by biochemical methods employing DNA from the specialized transducing phage λspc1, which carries the aroE-trkA-spc region of the E. coli chromosome. The phage DNA was cleaved by restriction endonucleases, and the generated DNA fragments used as templates for synthesis of r-proteins in a DNA-dependent cell-free system. Since the relative order of the DNA fragments created by the restriction endonucleases is known, a genetic map could be constructed. 相似文献