全文获取类型
收费全文 | 2150篇 |
免费 | 163篇 |
国内免费 | 1篇 |
专业分类
2314篇 |
出版年
2022年 | 13篇 |
2021年 | 30篇 |
2020年 | 15篇 |
2019年 | 12篇 |
2018年 | 24篇 |
2017年 | 25篇 |
2016年 | 41篇 |
2015年 | 57篇 |
2014年 | 78篇 |
2013年 | 111篇 |
2012年 | 138篇 |
2011年 | 134篇 |
2010年 | 88篇 |
2009年 | 82篇 |
2008年 | 114篇 |
2007年 | 135篇 |
2006年 | 122篇 |
2005年 | 117篇 |
2004年 | 113篇 |
2003年 | 112篇 |
2002年 | 102篇 |
2001年 | 46篇 |
2000年 | 37篇 |
1999年 | 55篇 |
1998年 | 22篇 |
1997年 | 31篇 |
1996年 | 32篇 |
1995年 | 23篇 |
1994年 | 22篇 |
1993年 | 16篇 |
1992年 | 37篇 |
1991年 | 31篇 |
1990年 | 39篇 |
1989年 | 29篇 |
1988年 | 28篇 |
1987年 | 25篇 |
1986年 | 29篇 |
1985年 | 22篇 |
1984年 | 16篇 |
1983年 | 15篇 |
1982年 | 22篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 12篇 |
1978年 | 6篇 |
1977年 | 6篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1973年 | 4篇 |
1968年 | 3篇 |
排序方式: 共有2314条查询结果,搜索用时 15 毫秒
991.
Two Distinct Types of Repression Domain in Engrailed: One Interacts with the Groucho Corepressor and Is Preferentially Active on Integrated Target Genes 总被引:18,自引:7,他引:11 下载免费PDF全文
992.
Linkage Disequilibrium and Haplotype Studies of Chromosome 8p 11.1-21.1 Markers and Werner Syndrome 总被引:2,自引:2,他引:0 下载免费PDF全文
Chang-En Yu Junko Oshima Katrina A. B. Goddard Tetsuro Miki Jun Nakura Toshio Ogihara Martin Poot Holger Hoehn Marco Fraccaro Charles Piussan George M. Martin Gerard D. Schellenberg Ellen M. Wijsman 《American journal of human genetics》1994,55(2):356-364
Werner syndrome (WS) is an autosomal recessive disorder, characterized as a progeroid syndrome, previously mapped to the 8p 11.1-21.1 region. Because WS is so rare, and because many patients are from consanguineous marriages, fine localization of the gene by traditional meiotic mapping methods is unlikely to succeed. Here we present the results of a search for a region that exhibits linkage disequilibrium with the disorder, under the assumption that identification of such a region may provide an alternative method of narrowing down the location of WRN, the gene responsible for WS. We present allele frequencies in Japanese and Caucasian cases and controls for D8S137, D8S131, D8S87, D8S278, D8S259, D8S283, fibroblast growth factor receptor 1, ankyrin 1, D8S339, and two polymorphisms in glutathione reductase (GSR), covering ~16.5 cM in total. We show that three of the markers examined—D8S339 and both polymorphisms in the GSR locus—show strong statistically significant evidence of disequilibrium with WRN in the Japanese population but not in the Caucasian population. In addition, we show that a limited number of haplotypes are associated with the disease in both populations and that these haplotypes define clusters of apparently related haplotypes that may identify as many as eight or nine independent WRN mutations in these two populations. 相似文献
993.
994.
Multi-Gene Family of Major Surface Glycoproteins of Pneumocystis carinii: Full-Size cDNA Cloning and Expression 总被引:2,自引:0,他引:2
The major surface glycoprotein (MSG) of Pneumocystis cariniiplays a crucial role in the fatal pneumonia caused by this organismin AIDS patients. A cDNA encoding a full-length MSG polypeptidewas isolated from a phage library of rat-derived P. cariniicDNAs. The deduced MSG, referred to as the MSG5 subtype, isa 120,765-Da protein composed of 1,076 amino acids and containsan anchoring hydrophobic sequence at the C-terminus of the protein.Sequence analyses of cloned MSG-cDNAs revealed an MSG-gene familywith 70% protein sequence identity between subtypes. P. cariniikaryotype hybridization analyses indicated that the MSG genefamily members are scattered throughout most of the P. cariniichromosomes. These recombinant MSG proteins reacted with theantiserum from P. carinii-infected rats, as expected, and antiserumgenerated against P. carinii-infected mice, indicating the existenceof common determinants in MSG polypeptides. The family of MSGproteins is rich in cysteine residues and these cysteine arehighly conserved in all MSG subtypes regardless of species specificity,suggesting the structural and/or functional importance of thesecysteine. The pathobiological significance of the MSG gene familyand its sequence diversity in P. carinii is discussed. 相似文献
995.
Miki Shirakihara Hideyoshi Yoshida † Hiroyuki Yokochi ‡ Hisao Ogawa § Taro Hosokawa ¶ Naoto Higashi Toshio Kasuya 《Marine Mammal Science》2007,23(3):694-706
We conducted aerial surveys of dugongs ( Dugong dugon ) using the line-transect method and snorkeling surveys of dugong feeding trails in 1998 and 1999 around Okinawa Island (26°30'N, 128°00'E) and the Sakishima Islands, southern Japan. A total of ten dugongs were sighted and feeding trails were confirmed in the sea grass beds off the east coast of Okinawa Island. In the Sakishima Islands, however, no dugongs were observed, and there was no evidence of feeding trails despite the existence of apparently suitable sea grass beds for feeding. The results of these surveys and other available information suggest that Okinawan dugongs represent a small, geographically isolated population. Our sightings of dugongs during the daytime, offshore of sea grass beds where feeding trails were recorded, suggest that Okinawan dugongs principally feed at night when human activities are limited. Survival of this remnant dugong population is threatened by habitat degradation and occasional entanglement mortality in fishing nets. 相似文献
996.
McmA‐dependent and ‐independent regulatory systems governing expression of ClrB‐regulated cellulase and hemicellulase genes in Aspergillus nidulans 下载免费PDF全文
997.
C55 bacteriocin produced by ETB‐plasmid positive Staphylococcus aureus strains is a key factor for competition with S. aureus strains 下载免费PDF全文
Miki Kawada‐Matsuo Fariha Shammi Yuichi Oogai Norifumi Nakamura Motoyuki Sugai Hitoshi Komatsuzawa 《Microbiology and immunology》2016,60(3):139-147
998.
Effects of disinfectants against norovirus virus‐like particles predict norovirus inactivation 下载免费PDF全文
Jun Sato Motohiro Miki Hiromi Kubota Jun Hitomi Hajime Tokuda Reiko Todaka‐Takai Kazuhiko Katayama 《Microbiology and immunology》2016,60(9):609-616
Human noroviruses (NoVs) are a major cause of epidemic and sporadic acute gastroenteritis worldwide. Public and personal hygiene is one of the most important countermeasures for preventing spread of NoV infection. However, no a practicable cell culture system for NoV had been developed, initial tests of the virucidal effectiveness of anti‐NoV disinfectants and sanitizers have been performed using surrogate viruses. In this study, NoV virus‐like particles (VLPs) were used as a new surrogate for NoVs and a method for evaluating NoV inactivation using them developed. This method is based on morphological changes in VLPs after treatment with sodium hypochlorite. VLP specimens were found to become deformed and degraded in a concentration‐dependent manner. Based on these results, the effects of sodium hypochlorite on VLPs were classified into four phases according to morphological changes and number of particles. Using the criteria thus established, the efficacy of ethanol, carbonates and alkali solutions against VLPs was evaluated. Deformation and aggregation of VLPs were observed after treatment with these disinfectants under specific conditions. To determine the degradation mechanism(s), VLPs were examined by SDS‐PAGE and immunoblotting after treatment with sodium hypochlorite and ethanol. The band corresponding to the major capsid protein, VP1, was not detected after treatment with sodium hypochlorite at concentrations greater than 500 ppm, but remained after treatment with ethanol. These results suggest that VLPs have excellent potential as a surrogate marker for NoVs and can be used in initial virucidal effectiveness tests to determine the mechanism(s) of chemical agents on NoVs. 相似文献
999.
Summer profundal hypoxia determines the coupling of methanotrophic production and the pelagic food web in a subtropical reservoir 下载免费PDF全文
Pei‐Chi Ho Noboru Okuda Takeshi Miki Masayuki Itoh Fuh‐Kwo Shiah Chun‐Wei Chang Silver Sung‐Yun Hsiao Shuh‐Ji Kao Megumu Fujibayashi Chih‐Hao Hsieh 《Freshwater Biology》2016,61(10):1694-1706
1000.
Yui Iwagaki Saeko Sugawara Yasuhisa Huruya Miki Sato Qiming Wu Shuang E 《Bioscience, biotechnology, and biochemistry》2018,82(4):709-715
AbstractWe aimed to find new physiological effects of the Japanese diet. First, to determine the key components in serum from mice fed the 1975 diet, serum from mice fed the 1960, 1975, 1990 or 2005 Japanese diet was analyzed using CE-TOFMS and LC-TOFMS. Based on these results, the key components were determined by principal component analysis. Among the identified compounds, GABA was included. Therefore, a stress reduction effect was inferred as a novel physiological effect of this diet. Next, we tested whether the 1975 diet had an actual stress reduction effect in mice. Mice were given the 1975 diet or a control diet for 4 weeks, after which they were divided into restraint stress and non-stress groups. Mice fed the 1975 diet had significantly decreased stress parameters compared with those fed the control diet. These results provide the first evidence that the 1975 Japanese diet has a stress reduction effect. 相似文献