全文获取类型
收费全文 | 894篇 |
免费 | 34篇 |
专业分类
928篇 |
出版年
2022年 | 5篇 |
2021年 | 6篇 |
2019年 | 14篇 |
2018年 | 8篇 |
2017年 | 2篇 |
2016年 | 17篇 |
2015年 | 29篇 |
2014年 | 29篇 |
2013年 | 95篇 |
2012年 | 37篇 |
2011年 | 49篇 |
2010年 | 26篇 |
2009年 | 44篇 |
2008年 | 38篇 |
2007年 | 40篇 |
2006年 | 33篇 |
2005年 | 54篇 |
2004年 | 64篇 |
2003年 | 57篇 |
2002年 | 56篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 11篇 |
1998年 | 21篇 |
1997年 | 16篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 12篇 |
1993年 | 14篇 |
1992年 | 10篇 |
1991年 | 4篇 |
1990年 | 10篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1983年 | 9篇 |
1982年 | 9篇 |
1981年 | 11篇 |
1980年 | 8篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1974年 | 3篇 |
1972年 | 2篇 |
1965年 | 1篇 |
1963年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有928条查询结果,搜索用时 0 毫秒
131.
Shinichi Nakamura Satoshi Nakashio Masato Mikawa Kiyotaka Yamakawa Seiichi Okumura Shoki Nishida 《Microbiology and immunology》1982,26(1):25-30
A total of 79 Clostridium difficile strains from healthy young and elderly adults, elderly patients without gastrointestinal disease, elderly patients receiving antibiotics without gastrointestinal complications, and elderly patients with antibiotic-associated diarrhea or pseudomembranous colitis were tested for their susceptibilities to 24 antimicrobial agents. All of the 79 strains were inhibited by low concentrations of rifampicin, metronidazole, fusidic acid, vancomycin, ampicillin, and penicillin G. The strains were highly resistant to aminoglycosides, trimethoprim, sulfamethoxazole, nalidixic acid, and cycloserine and often resistant to neomycin, cefoxitin, and cefalexin. Wide variations in the susceptibility of C. difficile strains to erythromycin, clindamycin, lincomycin, chloramphenicol, and tetracycline were found. Strains resistant to erythromycin, clindamycin, and lincomycin were more frequently found among strains isolated from elderly adults than those isolated from young adults, with particularly high frequency among strains isolated from elderly patients receiving antibiotics. None of the 23 strains isolated from healthy young adults was resistant to chloramphenicol. All of the 14 strains resistant to erythromycin, clindamycin, lincomycin, and chloramphenicol were sensitive to tetracycline and all of the 15 strains resistant to erythromycin, clindamycin, lincomycin, and tetracycline were sensitive to chloramphenicol. Only one out of 19 tetracycline-resistant strains was highly toxigenic, whereas 42 (70%) of 60 sensitive strains were highly toxigenic. 相似文献
132.
Jun-Ichi Nakamura Shin Yazawa Toshikazu Hada Takayuki Asao Hiroshi Naitoh Seiichi Takenoshita Masaaki Kosaka Suguru Akamatsu Tetsuya Tachikawa Yukio Nagamachi 《Glycoconjugate journal》1997,14(1):81-87
Levels of fucosylated antigens in sera from patients with liver diseases were examined by a newly developed sandwich-type enzyme immuno assay with the aid of anti-fucosylated antigen antibody, YB-2 which reacts simultaneously with Y, Leb and H type 2 antigens. When the cut-off value was set arbitrarily at mean [3 SD values of normal, 30 (69.8%) of the 43 patients with HCC, 14 (53.8%) of the 26 patients with liver cirrhosis (LC) and 24 (45.3%) of the 53 patients with chronic hepatitis (CH) were found to be positive, whereas all of the 30 samples from healthy controls were negative. The levels of -fetoprotein (AFP) and protein induced by vitamin K absence or antagonist-II (PIVKA-II) in HCC were not correlated with those of YB-2 antigens. The positive rates of the combination YB-2 and AFP assay and YB-2 and PIVKA-II assay in HCC were significantly higher (83.7 and 86.0%, respectively) than that of the AFP and PIVKA-II combination (65.1%) which had been reported to be the best combination up to this time. 相似文献
133.
134.
Rapid and efficientAgrobacterium-mediated transformation in rice 总被引:1,自引:0,他引:1
Seiichi Toki 《Plant Molecular Biology Reporter》1997,15(1):16-21
An improved protocol forAgrobacterium-mediated transformation of rice is described. The procedure permitted the regeneration of transgenic plants from callus in
only two months. 相似文献
135.
A novel polysaccharide having a N-acetylglucosamine (GlcNAc) residue as one of the constituents was synthesized by incubation of Acetobacter xylinum in a modified Schramm-Hestrin medium containing lysozyme-susceptible phosphoryl chitin (P-chitin) andd-glucose. HPLC of the culture medium snowed that the P-chitin added was depolymerized to monomeric and oligomeric P-chitins during the incubation, and the P-chitins with permeable sizes were utilized as a carbon source by the bacteria.13C NMR analysis revealed that the P-chitin consists mainly of GlcNAc 6-P residues. Furthermore, monomeric GlcNAc 6-phosphate was also found to enhance the incorporation of GlcNAc residues into the polysaccharide. However, no incorporation of the GlcNAc residues was observed when A. xylinum was incubated in a medium containing either highly phosphorylated chitin (DS = 1.90) or its oligomers produced by acid hydrolysis. 相似文献
136.
Atsushi Hayakawa Kazuo Kuwata Seiichi Era Masaru Sogami Hiroyuki Shimonaka Michio Yamamoto Shuji Dohi Hajime Hirose 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1997,698(1-2)
Human serum albumin is a mixture of mercapt- (HMA, reduced form) and nonmercaptalbumin (HNA, oxidized form). We studied the mercapt↔nonmercapt conversion of human serum albumin, which reflects the redox state of the extracellular fluids, in cardiac and other common surgical patients using high-performance liquid chromatography. Mean values of [(HMA)/(HMA + HNA)] ± standard deviation [fHMA ± σ], for patients who received common surgery (group 1) and cardiac surgery (group 2) at the start of anesthesia were0.636±0.50(n=83) and 0.615±0.062(n=14), respectively. fHMA values were markedly lower than those for healthy male adults of 0.750±0.028(n=28). fHMA values increased at 24 h after the start of anesthesia and decreased on the 4th postoperative day in most of the patients. These postoperative changes were prominent in surgical cardiac patients. Although fHMA values after the 7th postoperative day recovered to those at the start of anesthesia in almost all of common surgical patients, those in cardiac surgical patients, never recovered even on the 21st postoperative day. 相似文献
137.
Pseudorabies virus (PrV) YS-81 strain latently infected in 6-week-old BALB/c mice was detectable by nasal swabbing, and serum antibody was shown to increase in titer after intraperitoneal injection for 3 days with acetylcholine or dexamethasone. 相似文献
138.
Etiolated seedlings of Phaseolus mungo were fed with 14C-glucoseand the incorporation of 14C into shikimic and quinic acidswas determined. The incorporation of 14C into shikimic acidwas enhanced when non-labeled shikimic, quinic or 5-dehydroquinicacid was not significantly affected by these alicyclic acids.To examine whether the difference in biosynthetic patterns betweenshikimic and quinic acids is common in higher plants, flowersand leaves of several plants were fed with 14C-glucose or 14C-erythroseand the effciencies of these labeled sugars as precursors ofshikimic and quinic acids were compared. In seven of eight plantsamples, erythrose was superior to glucose as the precursorof shikimic acid, while there was no great difference in theefficiency of either sugar as the precursor of quinic acid.The possibility that the biosynthetic mechanism for quinic aciddiffers from that for shikimic acid is discussed. (Received September 12, 1973; ) 相似文献
139.
140.
Inhibition of NADPH oxidase subunits translocation by tea catechin EGCG in mast cell 总被引:1,自引:0,他引:1
Nishikawa H Wakano K Kitani S 《Biochemical and biophysical research communications》2007,362(2):504-509
The inhibitory mechanism of tea catechins for allergy remains undefined. We studied the effect of catechins, mainly EGCG, on the activation of mast cell line canine cutaneous mastocytoma cells (CM-MC). Compound 48/80 induced the degranulation in CM-MC dose dependently, whereas its release of beta-hexosaminidase was inhibited by EGCG and O-methylated EGCG (EGCG-Me). Both catechins were found to inhibit intracellular ROS generation dose dependently together with DPI. Intracellular ROS generation in human polymorphonuclear leukocytes was also inhibited by EGCG. Neither L-NAME, ebeselen nor NAC inhibited ROS generation. From the Western blot analysis of the subunits components of NADPH oxidase, we detected cytosolic subunits; p47(phox), p67(phox), p40(phox), rac2 and membrane subunits; gp91(phox), p22(phox) in CM-MC. Cytosolic subunits were translocated from cytosol to membrane time dependently after stimulation with compound 48/80. EGCG and DPI inhibited cytosolic subunits from translocating into membrane. These data suggest that EGCG inhibits the activation of NADPH oxidase in CM-MC. 相似文献