全文获取类型
收费全文 | 1340篇 |
免费 | 64篇 |
国内免费 | 1篇 |
出版年
2022年 | 10篇 |
2021年 | 16篇 |
2019年 | 7篇 |
2018年 | 21篇 |
2017年 | 13篇 |
2016年 | 29篇 |
2015年 | 32篇 |
2014年 | 32篇 |
2013年 | 87篇 |
2012年 | 69篇 |
2011年 | 76篇 |
2010年 | 47篇 |
2009年 | 32篇 |
2008年 | 66篇 |
2007年 | 64篇 |
2006年 | 76篇 |
2005年 | 62篇 |
2004年 | 66篇 |
2003年 | 73篇 |
2002年 | 58篇 |
2001年 | 31篇 |
2000年 | 34篇 |
1999年 | 25篇 |
1998年 | 21篇 |
1997年 | 14篇 |
1996年 | 13篇 |
1995年 | 7篇 |
1993年 | 7篇 |
1992年 | 22篇 |
1991年 | 16篇 |
1990年 | 21篇 |
1989年 | 11篇 |
1988年 | 18篇 |
1987年 | 12篇 |
1986年 | 13篇 |
1985年 | 20篇 |
1984年 | 16篇 |
1983年 | 11篇 |
1982年 | 8篇 |
1981年 | 7篇 |
1980年 | 14篇 |
1979年 | 6篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1975年 | 12篇 |
1974年 | 11篇 |
1972年 | 15篇 |
1971年 | 11篇 |
1968年 | 11篇 |
1967年 | 8篇 |
排序方式: 共有1405条查询结果,搜索用时 734 毫秒
51.
The marine opisthobranch molluscAplysia punctata was cultured at the Laboratoire de Biologie Marine in Concarneau, France.A. punctata veligers settled and underwent metamorphosis on the algaLomentaria articulata, but not onUlva spp., Palmaria marina, Laminaria spp. andFucus spp.Research supported by grants from The Arts Foundation and the Lerner Fund for Marine Research of the American Museum of Natural History. We wish to thank Director Yves Legal, College de France for his support and cooperation. 相似文献
52.
Mössbauer spectra of metapyrocatechase 总被引:1,自引:0,他引:1
53.
Four tests for antibody to varicella-zoster (V-Z) virus were compared; these were tests of complement fixation (CF), neutralization (NT), fluorescent antibody to membrane antigen (FAMA) and immune adherence hemagglutination (IAHA). Fifty-two sera from patients with varicella and zoster and from recipients of live varicella vaccine were examined by the 4 tests. The CF test was least sensitive, but the antibody titers by the NT, FAMA and IAHA tests were roughly comparable. The IAHA test was the simplest and fastest to perform, and appeared suitable for routine serological assay to V-Z virus. The correlation between the IAHA antibody titer and susceptibility of individuals to clinical varicella was investigated retrospectively using sera obtained during 2 outbreaks of varicella in an institution for children, where all the unvaccinated children had developed varicella symptoms. Most of the 25 pre-exposure sera from unvaccinated children examined by the IAHA test had tiers of less than 1:2. In contrast, all the 23 sera from vaccinated children who did not develop varicella had detectable antibody titers of 1:2 to 1:64. These results indicate that the IAHA titer reflects the susceptibility or resistance of individuals to clinical varicella. 相似文献
54.
Takumi Yoshizawa Nobuichi Morooka Yuzuru Sawada Shun-Ichi Udagawa 《Applied microbiology》1976,32(3):441-442
A tremorgenic mycotoxin was isolated from Penicillium paraherquei Abe ex G. Smith and identified as verruculogen. It was produced at the rate of approximately 1 mg/g of the dried fungal mycelium cultured on peptone-enriched Czapek-Dox medium at 28°C. 相似文献
55.
Cultured fibroblasts derived from rat carrageenin granuloma were treated with bleomycin and the synthesis of hexosamine-containing substances was compared with that in control cells. Four day treatment with o.1 mug bleomycin/ml resulted in a significant increase of the production of these macromolecules by the cells, though DNA synthesis was remarkably inhibited at this dose of bleomycin. The stimulatory effect could be seen as early as the second day of bleomycin treatment, and was enhanced with increasing treatment time. Further fractionation of the hexosamine-containing substances revealed that synthesis of acidic glycosaminoglycans was more sensitive to bleomycin than that of glycoproteins, i.e., acidic glycosaminoglycans increased by 80% and glycoproteins by 53% after four day treatment with 0.1 mug bleomycin/ml. The increased components of acidic glycosaminoglycans included not only hyaluronic acid but also sulphated glycosaminoglycans. Collagen synthesis was increased by 23% by the same dose of bleomycin. N-Acetyl-beta-glucosaminidase, one of the degradation enzymes for acidic glycosaminoglycans released into the cultured medium, was decreased significantly by bleomycin. 相似文献
56.
Keishi Abe Yoichi Otsuka Minoru Yasujima Satoru Ciba Masahide Seino Nobuo Irokawa Kaoru Yoshinaga Fumio Hirata Shiro Ohki Nobuhiko Nakazawa Toshio Hanyu 《Prostaglandins & other lipid mediators》1976,12(5):843-848
The excretion rates of main urinary metabolite of PG F2α were measured radioimmunologically in 4 healthy persons and in 13 essential hypertensives. The resting values were 9.3±0.73 in the former and 10.4±2.17 ng/min in the latter. There was no significant differences between them. The excretion of the metabolite decresed prominently after the administration of furosemide. The percent decrease was 57% in healthy persons and 70% in essential hypertension. The percent result supports that furosemide inhibit the catabolism of PG F2α. 相似文献
57.
Kinetics of proton transfer between lysozyme and a pH indicator p-nitrophenol (p-Np) were measured by the temperature-jump method in a pH range of 6.0–7.0. Two well-defined relaxation processes were observed. The fast process (τ ? 15 μsec) was also observed for a lysozyme derivative succinylated at the terminal α-amino group of Lys 1. Therefore, the fast process was found to be attributable to the proton transfer reaction of His 15 with p-Np. The slow process (τ ? 50 μsec) was found to be characteristic of the proton transfer reaction of Glu 35, because it disappeared completely in solution containing a lysozyme derivative having an ester crosslink between the carboxyl group of Glu 35 and indol C-2 of Trp 108. The rate constants for proton transfer from Glu 35 and His 15 to p-Np were found to be 9 × 106/sec/M (±65%, 23°C) and 3 × 108/sec/M (±20%, 25°C), respectively. These data indicate that the proton of the carboxyl group of Glu 35 is kinetically stabilized in lysozyme. 相似文献
58.
A case of Turner's syndrome with short stature and 45, XO/46, XXr mosaicism in chromosome study was presented. With special emphasis on endocrinological study, the size of the breasts was normal in contrast to the poor development of the breasts in most of types of Turner's syndrome. She showed normal thyroid function, slightly low level of urinary 17-OHCS, decreased 17-KS, poor response in metopirone test and poor response of HGH to insulin. 相似文献
59.
60.
Kimiko Anno Kimiko Otsuka Nobuko Seno 《Biochimica et Biophysica Acta (BBA)/General Subjects》1974,362(1):215-219
Considerable amounts of water-soluble polysaccharides were found in the test of the tunicate Halocynthia roretzi. After fractionation with ethanol, a chitin sulfate-like polysaccharide was isolated. From the results of chemical analysis, optical rotation, infrared spectrum and alkaline treatment, it is suggested that the predominant structure for this polysaccharide is (1→4)-2-acetamido-2-deoxy-6-O-sulfo-β-D-glucopyranan. 相似文献