全文获取类型
收费全文 | 4099篇 |
免费 | 291篇 |
国内免费 | 1篇 |
出版年
2023年 | 20篇 |
2022年 | 54篇 |
2021年 | 111篇 |
2020年 | 62篇 |
2019年 | 61篇 |
2018年 | 91篇 |
2017年 | 70篇 |
2016年 | 125篇 |
2015年 | 195篇 |
2014年 | 188篇 |
2013年 | 273篇 |
2012年 | 320篇 |
2011年 | 353篇 |
2010年 | 202篇 |
2009年 | 178篇 |
2008年 | 226篇 |
2007年 | 273篇 |
2006年 | 264篇 |
2005年 | 223篇 |
2004年 | 250篇 |
2003年 | 211篇 |
2002年 | 204篇 |
2001年 | 33篇 |
2000年 | 20篇 |
1999年 | 31篇 |
1998年 | 42篇 |
1997年 | 26篇 |
1996年 | 27篇 |
1995年 | 25篇 |
1994年 | 13篇 |
1993年 | 19篇 |
1992年 | 20篇 |
1991年 | 17篇 |
1990年 | 17篇 |
1989年 | 5篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 14篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1981年 | 12篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1974年 | 5篇 |
1973年 | 7篇 |
1971年 | 6篇 |
1970年 | 6篇 |
1969年 | 5篇 |
排序方式: 共有4391条查询结果,搜索用时 15 毫秒
1.
Igor Loncaric Gabrielle L. Stalder Kemal Mehinagic Renate Rosengarten Franz Hoelzl Felix Knauer Chris Walzer 《PloS one》2013,8(12)
In order to test whether rooks (Corvus frugilegus) represent good indicators for the potential circulation of antibiotics in their native habitat, two populations with different migratory behavior were tested for the presence of beta-lactamase producing Enterobacteriaceae and methicillin-resistant Staphylococcus aureus (MRSA). In all, 54 and 102 samples of fresh feces of a migratory and a resident population were investigated. A total of 24 and 3 cefotaxime-resistant enterobacterial isolates were obtained from the migratory and resident population, respectively. In these isolates CTX-M-1 (n = 15), CTX-M-3 (n = 3), and CTX-M-15 (n = 3) genes were detected. TEM-1 and OXA-1 were associated with CTX-M in 3 and 2 isolates, respectively. In two E. coli isolates CMY-2 could be detected, where from one isolate displayed an overexpression of chromosomal AmpC as well. Among E. coli isolates the most common phylogenetic group was A (n = 11) and ST1683 (n = 5). In one E. coli of B2-ST131 the rfbO25b locus was detected. Three Enterobacter isolates were stably derepressed AmpC-producers. In five samples of the migratory population, PVL positive MRSA could be isolated. Two isolates were typed SCCmec IVa, spa type t127, and ST1. Three isolates carried a SCCmec type IVc, with spa type t852 and ST22. The highly significant difference of the occurrence of antibiotic resistance between the migratory population from eastern Europe compared to resident population in our study indicates that rooks may be good indicator species for the evaluation of environmental contamination with antibiotic resistant bacteria, especially due to their ecology, foraging behavior and differing migratory behavior. 相似文献
2.
3.
Nimra Khan Dylan Pelletier Thomas S. McAlear Nathalie Croteau Simon Veyron Andrew N. Bayne Corbin Black Muneyoshi Ichikawa Ahmad Abdelzaher Zaki Khalifa Sami Chaaban Igor Kurinov Gary Brouhard Susanne Bechstedt Khanh Huy Bui Jean-François Trempe 《Structure (London, England : 1993)》2021,29(6):572-586.e6
- Download : Download high-res image (220KB)
- Download : Download full-size image
4.
5.
6.
7.
The soybean trypsin inhibitor conjugate with a thermo-reactive water soluble polymer, poly(N-vinyl caprolactam), was successfully
used for thermally induced affinity precipitation of trypsin. The validity of the developed procedure was proven by a model
separation of trypsin from dilute solution containing a large excess of bovine serum albumin. 相似文献
8.
Igor A. Krasheninnikov Anton A. Komar Ivan A. Adzhubei 《Journal of Protein Chemistry》1991,10(5):445-453
Examination of nascent globin peptides accumulatingin vitro during globin synthesis in rabbit reticulocyte lysates was carried out. A view was supported that nonrandom distribution of codons with different usage frequencies in mRNA may determine the messenger's translation kinetics. Regions of reduced translation of - and -globin polypeptide chains were localized, and the cotranslational protein-folding model suggested previously was substantiated. An active conjunction of synthesis and folding of proteins was proposed as one of the main destinations of a translation nonuniformity. 相似文献
9.
I A Bochkov M Kravi A I Tse?tlina A Kh Ka?tmazov M S Shevchuk G S Barsukova 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1991,(10):19-22
The formation of microflora on the laryngeal mucosa in newborn infants during the first 5 days of their life was studied in one of the maternity hospitals of Moscow. In this work modern methods of the isolation and identification of aerobic and anaerobic microorganisms were used, and the results thus obtained were computer-processed. In the maternity hospital of the "mother-child" type the microbial colonization of the laryngeal mucosa by normal and opportunistic microorganisms was noted in newborn infants. A wave-like course of the formation of laryngeal microflora, indicative of microbial succession occurring in the child, was revealed. The attempt to establish the cases of microbial interference between the species colonizing the laryngeal mucosa revealed that it was very rarely observed in 5-day-old newborns. This feature was seemingly the cause of low resistance of the larynx to colonization in newborn infants, which determined frequent colonization of their laryngeal mucosa with Staphylococcus aureus and Klebsiella. 相似文献
10.
Igor Hudec 《Hydrobiologia》1983,107(1):63-69
Scapholeberis echinulata Sars is rediscribed, based on type material of Sars (S. echinulata), Daday (s. erinaceus) and the author's own samples. A differential diagnosis with Scapholeberis spinifera Nicolet and S. mucronata O. F. Müller, S. microcephala Sars, S. kingi Sars and S. aurita Fischer is given. 相似文献