全文获取类型
收费全文 | 1626篇 |
免费 | 114篇 |
出版年
2021年 | 11篇 |
2020年 | 12篇 |
2019年 | 13篇 |
2018年 | 17篇 |
2017年 | 14篇 |
2016年 | 18篇 |
2015年 | 40篇 |
2014年 | 52篇 |
2013年 | 133篇 |
2012年 | 78篇 |
2011年 | 78篇 |
2010年 | 40篇 |
2009年 | 31篇 |
2008年 | 69篇 |
2007年 | 63篇 |
2006年 | 59篇 |
2005年 | 66篇 |
2004年 | 64篇 |
2003年 | 67篇 |
2002年 | 63篇 |
2001年 | 70篇 |
2000年 | 80篇 |
1999年 | 52篇 |
1998年 | 16篇 |
1997年 | 16篇 |
1996年 | 18篇 |
1995年 | 16篇 |
1993年 | 15篇 |
1992年 | 52篇 |
1991年 | 42篇 |
1990年 | 35篇 |
1989年 | 46篇 |
1988年 | 29篇 |
1987年 | 23篇 |
1986年 | 25篇 |
1985年 | 38篇 |
1984年 | 19篇 |
1983年 | 18篇 |
1982年 | 11篇 |
1981年 | 15篇 |
1980年 | 7篇 |
1979年 | 13篇 |
1978年 | 7篇 |
1977年 | 11篇 |
1976年 | 8篇 |
1975年 | 14篇 |
1974年 | 6篇 |
1973年 | 11篇 |
1968年 | 5篇 |
1966年 | 5篇 |
排序方式: 共有1740条查询结果,搜索用时 15 毫秒
991.
992.
K Noda M Oda M Sato N Yoshida 《International journal of peptide and protein research》1990,36(2):197-200
A series of p-nitroanilides of t-butyloxycarbonylamino acids, including Boc-Trp, Boc-Asn, Boc-Gln, Boc-Ser(But), Boc-Thr(But), Boc-Asp(OBut), Boc-Lys(TFA), and Boc-His(Boc), were prepared conveniently by the mixed anhydride method using 2,2-dimethylpropanoic chloride (pivaloyl chloride). The products were obtained in 40-60% yields after purification by column chromatography on Sephadex LH-20. p-Nitroanilide of histidine was purified after deprotection of Boc-His(Boc)-pNA and obtained as H-His-pNA.2HCl. 相似文献
993.
994.
Kiyoshi Tohyama Toshizo Sakurai Hiroshi Arai Akira Oda 《Microbiology and immunology》1972,16(5):385-395
Twenty-three temperate phages of Lactobacillus salivarius isolated from human feces were studied as to their morphological, biological, and serological properties. (1) Among 30 strains of L. salivarius tested, 23 strains were lysed by induction with mitomycin C (MC). In all these lysates, phage particles were detected by electron microscopic examination. (2) These phages were morphologically divided into three groups: particles with a regular hexagonal head and a long flexible tail; particles having a regular hexagonal head with or without a short tail-like structure; particles with an elongated head and a long noncontractile tail. (3) Only two, phage 223 having an elongated head and phage 227 with a regular hexagonal head and a long noncontractile tail, produced tiny and very turbid plaques on several host bacteria. Six phages could produce only inhibition zones, ranging from complete inhibition through partial inhibition to normal growth by a serial dilution spot test. (4) All these killer particles could also inhibit the growth of their producer cells. (5) A serological relationship was observed between temperate phages and killer particles, and this was somewhat consistent with the morphological groupings. 相似文献
995.
Synthesis and characterization of trisodium salt of bis(thiosalicylato)aurate(I): Na3[Au(TSA)2]·5H2O
K. Nomiya H. Yokoyama H. Nagano M. Oda S. Sakuma 《Journal of inorganic biochemistry》1995,60(4):289-297
Sodium salt of a water-soluble, anionic, and monomeric 1:2 complex of Au(I) with a dianion of thiosalicylic acid TSA2−(Hin2TSA) = o-HS(C6H4)COOH) was first prepared and isolated as colorless needle crystals through a stoichiometric reaction of NaAuCl4:H2TSA:NaOH = 1:4:8 molar ratio in aqueous/EtOH solution. In this reaction, TSA2− ligand has played a role of a reducing agent for the starting Au(III) ion and also of donor ligands coordinating to the reduced Au(I). This compound was characterized by complete elemental analyses, TG/DTA, FT-IR, 2D-NMR (1H-1H COSY, 1H-13C HMBC, and 1H-13C HMQC) spectroscopy, and the molmass measurement based on the cryoscopic method. It was shown that this complex was a monomeric species of Au(I) with a formula of Na3[Au(TSA)2]·5H2O in the solid state, but not a polymeric species even in aqueous solution. A full assignment of seven carbon and four proton resonances in the coordinated TSA2− ligand was achieved by the 2D 1H-13C HMBC NMR technique. 相似文献
996.
F Masugi T Ogihara S Saeki K Sakaguchi Y Kumahara K Satouchi M Oda K Saito K Tokunaga 《Life sciences》1988,42(4):455-460
Renovascular hypertension is relieved by percutaneous transluminal renal angioplasty. In four patients with renovascular hypertension, platelet-activating factor (PAF) was found to be released into the ipsilateral renal venous blood after percutaneous transluminal renal angioplasty, but was not found in the contralateral renal venous blood following this procedure. Anti-platelet-activating factor with a lipid-like property was also found, and its polarity was slightly lower than that of PAF judging by its behavior on thin layer chromatography. Anti-platelet-activating factor completely blocked the aggregation of rabbit platelets induced by PAF, ADP or arachidonic acid. These results indicate that PAF and anti-platelet-activating factor are released into renal venous blood following percutaneous transluminal renal angioplasty in patients with renovascular hypertension. 相似文献
997.
Hye-Ji Oh Hyun-Gi Jeong Gui-Sook Nam Yusuke Oda Wei Dai Eui-Haeng Lee 《Animal cells and systems.》2017,21(2):133-140
Rotifer community is often used as a taxon-based bioindicator for water quality. However, studies of the planktonic community from the viewpoint of functional groups in freshwater ecosystems have been limited, particularly for rotifers. Because rotifers have various trophi types determining their feeding strategies, thereby representing an ecological niche, their functional feeding groups can act as biological and ecological indicators in lakes and reservoirs where planktonic communities are dominant. We analyzed the patterns of spatial distribution of the rotifer community in various reservoirs and then its relationship with water quality through redundancy and regression analyses. Compared with taxon-based composition, the response of trophi-based composition appears simplistic and showed clearer tendency in relation with water-quality variables. Each trophi responded differently by the degree of eutrophication indicating that each trophi group is possibly affected by environments such as the combinations of water-quality variables in different ways. 相似文献
998.
The effect of interleukin (IL)-1 on the occurrence of stress-induced gastric erosions was examined in rats. The intracerebroventricular (icv) administration of IL-1 beta significantly inhibited the occurrence of water-immersion restraint stress-induced gastric erosion at doses of 200 ng, 500 ng and 1 microgram, whereas the intravenous (iv) administration of IL-1 beta altered the occurrence of gastric erosion only at a dose of 1 microgram. The inhibitory effect of IL-1 alpha icv administered on the occurrence of gastric erosion was found only at a dose of 1 microgram. The inhibitory effect of IL-1 beta icv administered on the occurrence of stress-induced gastric erosion was not influenced by icv administration of alpha-helical CRF(9-41), a corticotropin-releasing factor (CRF) receptor antagonist. Indomethacin completely blocked the inhibitory action of IL-1 beta icv administered on stress-induced gastric erosion. It is concluded from these results that IL-1 acts mainly in the central nervous system to inhibit the occurrence of stress-induced gastric erosion and that the IL-1 beta-induced inhibition of gastric erosion is mediated by prostaglandin in a manner that is independent of brain CRF. 相似文献
999.
K Abe T Shikata K Fujisawa M Yamauchi H Matsushita H Suzuki T Oda 《Japanese journal of medical science & biology》1986,39(3):119-127
Two chimpanzees were inoculated intravenously with acute-phase sera obtained from two patients with epidemic hepatitis. They developed histopathologically confirmed hepatitis. Electron microscopic examination of the liver showed peculiar cytoplasmic tubular structures in the hepatocytes. These ultrastructural findings were similar to those described for the livers of chimpanzees inoculated with the F strain of non-A, non-B hepatitis agent derived from a posttransfusion hepatitis case. The chimpanzee that had recovered from hepatitis caused by the F strain of non-A, non-B hepatitis agent was re-challenged with the serum from one of the patients. The chimpanzee developed neither clinical signs nor histological changes of hepatitis. These results suggested that non-A, non-B hepatitis agent was involved not only in post-transfusion hepatitis but also in epidemic hepatitis. 相似文献
1000.