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101.
Expression of adenovirus type 12 early region 1 in KB cells transformed by recombinants containing the gene. 总被引:10,自引:4,他引:6 下载免费PDF全文
K Shiroki I Saito K Maruyama Y Fukui Y Imatani K I Oda H Shimojo 《Journal of virology》1983,45(3):1074-1082
The adenovirus type 12 (Ad12) early region 1 (E1) gene was introduced into KB cells by using a dominant selection vector, pSV2-gpt, and over 80 Gpt+ KB cell clones were established. Three types of recombinant DNAs (gAE1A, gARC, and gABA) were constructed. They contained the AccI-H, EcoRI-C, and BamHI-A fragments, respectively, of Ad12 DNA in pSV2-gpt. Five of 50 (10%) gABA-transformed cell clones, 12 of 18 (67%) gAE1A-transformed cell clones, and 10 of 18 (56%) gARC-transformed cell clones complemented the growth of Ad5 dl312 (deletion in E1A) and were designated as Gpt+ Ad+ cell clones. In these cell clones at their early passages, recombinant genome sequences were detected in cellular DNA and were expressed. T antigen g (the E1A gene product) was detected by immunofluorescence. The Gpt+ Ad+ cell clones supported the growth of Ad5 deletion mutants in parallel with the expression of Ad12 E1A or E1A plus E1B genes. After infection of Gpt+ Ad+ cell clones with Ad5 dl312, the early genes of dl312 were efficiently transcribed, indicating the expression of the pre-early function of the Ad12 E1A gene. Two clones each from gAE1A-,gARC-, and gABA-transformed cells were subcultured for a long period to determine the stability of the transfecting DNAs. Subculture in a nonselective medium resulted in cells which lost the transfecting DNAs. Subculture in a selective medium resulted in the selection of cells which maintained the gpt gene expression but lost the Ad12 gene expression. These results indicate that the transfecting DNA is present in an unstable state in KB cells. 相似文献
102.
Throughout gestation pregnant mice received drinking water which contained [methyl-3H]thymidine (18.5 kBq/ml). The newborn mice were divided into two groups. One group was nursed by their own mothers, which were further supplied with tritiated thymidine until 4 weeks after delivery (Experiment I). The other group was nursed by "nonradioactive mothers" which were given no tritiated thymidine (Experiment II). Tritium incorporation into the small molecular components of the acid-soluble fraction, lipid, RNA, DNA, and protein was analyzed for the newborn mice at various ages. In Experiment II, total radioactivity per gram tissue decreased initially after birth with a half life of 2.5-2.9 days in spleen, liver, intestine, stomach, thymus, lung, kidney, heart, and brain. At about 2 weeks after birth, a slower component of tritium elimination due mainly to the DNA-bound tritium appeared. Specific activity of DNA at birth was organ specific, highest in heart and lowest in thymus. Cumulative absorbed dose in various organs was estimated for the first 4 weeks after birth based upon an assumption that total and DNA-bound tritium are uniformly distributed. The result showed that organ specificity of dose accumulation is obvious for DNA-bound tritium, highest in spleen (1.15 mGy) and lowest in brain (0.13 mGy). It was also shown that the tritium supply from mother's milk is of minor importance for dose accumulation of DNA-bound tritium in the cell nuclei of organs of suckling mice. 相似文献
103.
The effects of photoperiod on the sex expression of cucumberflowers were examined in relation to the endogenous GA and ethyleneproduction with short day (SD)- and long day (LD)-sensitivecultivars under controlled environmental conditions. Growth of plants was greatly reduced under LD in both typesof cultivars. Reflecting this, GA activity was greater and ethyleneevolution less in plants grown under SD than in those underLD. However, the number of pistillate flowers increased underSD and LD in SD- and LD-sensitive cultivar, respectively, indicatingthat a change in sex expression did not coincide with hormonalchanges in the SD-sensitive cultivar. Thus, the effect of photoperiodon the sex expression was found to be separate, at least inpart, from the effect of GA or ethylene in cucumber. (Received September 16, 1982; Accepted December 7, 1982) 相似文献
104.
105.
Quantitative isolation of total glycosphingolipids from animal cells 总被引:49,自引:0,他引:49
The quantitative isolation of total glycosphingolipids from crude lipid extracts without contamination from other lipid classes is described. The method consists of (a) acetylation of total lipids with pyridine and acetic anhydride, (b) separation of acetylated glycolipids from nonglycolipids on a magnesia-silica gel (Florisil) column, and (c) deacetylation of glycolipid in chloroform-methanol-sodium methoxide. This method is useful for determination of microgram quantities of glycolipids derived from less than 1 ml of packed cells. 相似文献
106.
107.
Possible site of flavonoid synthesis in the photosynthetic apparatus (Short Communication) 下载免费PDF全文
Koshi Saito 《The Biochemical journal》1974,144(2):431-432
Chloroplasts were prepared in aqueous suspension from buckwheat (Fagopyrum esculentum Moench.) seedlings, and the incorporation of [1-(14)C]acetic acid into quercetin (3,5,7,3',4'-pentahydroxyflavone) by the isolated chloroplast preparations was investigated. 相似文献
108.
109.
Comparison of the Pathogenicity for Mice of Mycobacterium fortuitum and Mycobacterium abscessus 总被引:3,自引:0,他引:3 下载免费PDF全文
The pathogenicity for mice of 12 strains of Mycobacterium abscessus was compared with that for 8 strains of M. fortuitum. Both species caused lesions in kidneys and produced "spinning disease" resulting from inner ear infections. No major differences in pathogenicity of these two species were demonstrated. Strain to strain variation was marked, especially with M. abscessus. For example, 1.6 x 10(6) organisms of strain 11188 of M. abscessus produced death in four of five animals within 42 days, whereas strain 380 of M. abscessus failed to produce any deaths within 42 days. In the case of M. fortuitum, the greatest mortality observed was one of five animals, yet the incidence of spinning disease and kidney disease occurred earlier postinfection than in mice infected with M. abscessus. Histologically, abscess formation by a strain of M. abscessus was greater than by a strain of M. fortuitum, but this difference cannot be interpreted as a species difference. 相似文献
110.