首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   9905篇
  免费   953篇
  国内免费   18篇
耳鼻咽喉   168篇
儿科学   394篇
妇产科学   205篇
基础医学   1302篇
口腔科学   128篇
临床医学   985篇
内科学   1713篇
皮肤病学   357篇
神经病学   1018篇
特种医学   470篇
外科学   1290篇
综合类   240篇
一般理论   5篇
预防医学   1248篇
眼科学   145篇
药学   688篇
中国医学   4篇
肿瘤学   516篇
  2021年   103篇
  2020年   71篇
  2019年   112篇
  2018年   137篇
  2017年   131篇
  2016年   100篇
  2015年   122篇
  2014年   202篇
  2013年   301篇
  2012年   339篇
  2011年   370篇
  2010年   235篇
  2009年   221篇
  2008年   399篇
  2007年   493篇
  2006年   417篇
  2005年   375篇
  2004年   375篇
  2003年   359篇
  2002年   354篇
  2001年   340篇
  2000年   405篇
  1999年   320篇
  1998年   192篇
  1997年   146篇
  1996年   153篇
  1995年   149篇
  1994年   141篇
  1993年   121篇
  1992年   281篇
  1991年   227篇
  1990年   264篇
  1989年   224篇
  1988年   236篇
  1987年   202篇
  1986年   203篇
  1985年   227篇
  1984年   140篇
  1983年   107篇
  1982年   116篇
  1981年   79篇
  1980年   80篇
  1979年   117篇
  1978年   106篇
  1977年   87篇
  1976年   104篇
  1975年   83篇
  1974年   93篇
  1973年   93篇
  1972年   74篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Although the infection of BHK cells with foot-and-mouth disease virus did not cause a marked inhibition of cellular protein synthesis, the proteins synthesized gradually changed from host-specific to virus-specific. The synthesis of at least thirteen virus-induced proteins was demonstrated by polyacrylamide electrophoretic analysis of the infected cells. Only a small proportion of the virus-induced proteins was incorporated into the mature virus particles. The addition of amino acid analogues caused an accumulation of the larger mol. wt. proteins, suggesting that in infected cells, some cleavages occurred, giving rise to the smaller mol. wt. proteins. The operation of the precursor-cleavage mechanism was more clearly shown in pulse-chase experiments, in which it was found that the proteins were degraded from larger to smaller mol. wt.  相似文献   
82.
In fetal testes of non-inbred guinea pigs, virus-like particles were seen in the primordial germ cells, but not in the somatic cells. Using the particles as a marker for the gonocytes it was possible to trace the phagocytosis of degenerating gonocytes by the Sertoli cells in the fetal testis.  相似文献   
83.
Cholera and other vibrioses in the United States   总被引:62,自引:0,他引:62  
  相似文献   
84.
In 1985 the families of 137 passengers killed when a Delta Airlines jet crashed at Dallas-Fort Worth International Airport stayed in a secluded hotel while waiting for the victims' bodies to be retrieved and identified. In this protected environment, which the author calls the "libidinal cocoon," the families received intensive nurturing from the author, a Dallas psychiatrist; a team of Red Cross nurses; hotel staff; airline representatives; clergy; and each other. The supportive environment allowed the families to regress safely and to satisfy the basic yearning, intensified in times of personal loss, for an idealized caretaker who will meet all one's needs. The author believes this kind of intervention may be useful in future disasters with massive casualties.  相似文献   
85.
Instabilities of the wrist   总被引:2,自引:0,他引:2  
Carpal instability is the result of ligamentous injury to the wrist. Although any ligament may be injured, certain recurring patterns are frequently seen. Common to the treatment of all instability patterns is the need to transfer load from the capitate to the radius: reliably, without stressing normal joints, and while preserving functional motion. Limited wrist arthrodesis fulfills these needs. The radius and carpal bones are shaped so that in their "normal" position, they are preloaded. Were it not for complex ligamentous systems, the bones would immediately assume unloaded "neutral anatomic" positions. Because the shape of the wrist bones tends to displace them with significant forces, current ligamentous reconstructions are inadequate. Common radial side instabilities invariably lead to degenerative arthritis.  相似文献   
86.
Levels and causes of stress among residents   总被引:7,自引:0,他引:7  
Medical and dental residents at the University of Rochester Medical Center were surveyed to measure stress and its causes. Their stress, as measured by the brief symptom inventory, showed levels slightly above those of an adult comparison group. The average levels of stress decreased with the residents' advancing levels of training. Comparison of the top quartile with the lowest quartile of scores of everyday stress showed significantly elevated stress for rotations in the emergency room, greater frequency of being on call, and lesser amount of sleep. The residents' reports showed that the bleakest three days of residency tended to occur in the first year and during intensive care rotations. Stress during these bleakest times was significantly higher than everyday levels. The residents described the major causes of distress during bleakest times as lack of sleep, inadequate support from senior professionals, large patient load, and competition from peers. "High quality" teaching rounds, a night-float system, and sick leave were felt by the residents to lessen stress. To cope with the stress, the residents reported they talked to others, tried to see humor in the situation, or slept.  相似文献   
87.
88.
89.
The need for an animal model to test bone graft materials simulating a weight bearing clinical situation is identified. The concept, design and operative detail of a new model is described. This model involved the creation of a mid-diaphyseal wedge defect in the femur of the adult beagle which separated both cortices, plating with a six-hole dynamic compression plate, and allowed immediate full weight bearing. At six months plates were removed and immediate weight bearing was allowed for an additional six months to sacrifice. The initial animal project utilizing this model to evaluate a hydroxyapatite based synthetic graft material was performed using 12 dogs. In addition to the operative procedure, the retrieval testing in torsion of 12 healed grafted bones and their 12 contralateral unoperated controls is described and evaluated. Results showed no statistically significant difference between the torsional strength of test and control femurs (p less than or equal to 0.05). In addition, the future development of the model is discussed.  相似文献   
90.
Since previous studies have suggested that the coupling of oxidation to phosphorylation is impaired in Alzheimer brain and fibroblasts, the effects of carbonyl cyanide m-chlorophenylhydrazone, a hydrazone known to uncouple mitochondrial oxidative phosphorylation, were tested on the development of immunoreactivity with antibodies to "Alzheimer antigens" in cultured fibroblasts from cognitively intact subjects. The fibroblasts were exposed for 10 to 14 days to a medium (DMd) modeled on media that favor neuronal differentiation in fetal brain cultures. The addition of a 10-microns concentration of carbonyl cyanide m-chlorophenylhydrazone to the DMd culture medium increased by more than 10-fold the proportion of cells reacting immunocytochemically with antibodies to paired helical filaments and by 157-fold the proportion of cells reacting with the Alz-50 monoclonal antibody. These observations suggest that the oxidative abnormalities previously described in tissues from patients with Alzheimer's disease may contribute to the accumulation of abnormal cytoskeletal materials in this disorder.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号