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   477篇
  免费   36篇
  国内免费   5篇
耳鼻咽喉   5篇
儿科学   49篇
妇产科学   3篇
基础医学   34篇
口腔科学   15篇
临床医学   63篇
内科学   90篇
皮肤病学   1篇
神经病学   6篇
特种医学   142篇
外科学   22篇
综合类   30篇
预防医学   20篇
眼科学   2篇
药学   23篇
肿瘤学   13篇
  2022年   1篇
  2021年   4篇
  2020年   1篇
  2019年   2篇
  2018年   9篇
  2017年   6篇
  2016年   6篇
  2015年   10篇
  2014年   18篇
  2013年   19篇
  2012年   8篇
  2011年   4篇
  2010年   10篇
  2009年   7篇
  2008年   10篇
  2007年   10篇
  2006年   9篇
  2005年   6篇
  2004年   9篇
  2003年   7篇
  2002年   8篇
  2001年   8篇
  2000年   6篇
  1999年   17篇
  1998年   30篇
  1997年   34篇
  1996年   34篇
  1995年   30篇
  1994年   30篇
  1993年   19篇
  1992年   6篇
  1991年   5篇
  1990年   5篇
  1989年   14篇
  1988年   17篇
  1987年   15篇
  1986年   16篇
  1985年   15篇
  1984年   9篇
  1983年   11篇
  1982年   4篇
  1981年   9篇
  1980年   5篇
  1979年   2篇
  1978年   2篇
  1977年   3篇
  1976年   5篇
  1975年   2篇
  1971年   1篇
排序方式: 共有518条查询结果,搜索用时 15 毫秒
61.
62.
BACKGROUND: The pattern of growth of the uterus was examined by ultrasound examinations of 358 girls who attended a paediatric endocrine outpatient department but were shown not to have any endocrine defect. METHOD: The uterus was measured in length and width at the cervix and at the fundus (cm). Endometrial thickness was measured (mm). Scans were divided by Tanner breast stage and the dimensions compared by one way analysis of variance (ANOVA, with the Student Newman Keuls post hoc test). RESULTS: There was an increase in uterine length, diameter of the fundus, and endometrial thickness at each breast stage from 1 to 5 (ANOVA, p < 0.05), and in the diameter of the cervix with each breast stage from 1 to 4 (ANOVA, p < 0.05). The ratio of the fundus to the cervix increased from 0.95 to 1.29 between breast stages 1 and 4. CONCLUSION: The onset of puberty is marked by an increase in the dimensions of the uterus and in endometrial thickness, but also by a change in the shape of the uterus from a tubular to a pear shaped organ.  相似文献   
63.
64.
ABSTRACT Isolated congenital tricuspid valve dysplasia is a rare and potentially lethal congenital heart disease that can be easily confused with persistent pulmonary hypertension of the newborn. We describe a neonate with isolated congenital tricuspid valve dysplasia who did not respond to mechanical ventilation but improved by tolazoline. Clinicians should be aware that the initial fulminant course of this condition may be reversed by reducing the pulmonary vascular resistance, thereby allowing time for spontaneous recovery.  相似文献   
65.
Endoscopic retrograde biliary drainage   总被引:1,自引:0,他引:1  
Marks  WM; Freeny  PC; Ball  TJ; Gannan  RM 《Radiology》1984,152(2):357
  相似文献   
66.
Large-cell lymphoma of the spleen: CT appearance   总被引:2,自引:0,他引:2  
Meyer  JE; Harris  NL; Elman  A; Stomper  PC 《Radiology》1983,148(1):199
  相似文献   
67.
Pulmonary infection caused by the opportunistic organisms Penicillium marneffei and Stenotrophomonas maltophilia in patients with Job’s syndrome is rare and not well documented. The case of a 30-year-old man with Job’s syndrome who developed recurrent pneumonia and lung abscesses caused by P marneffei and S maltophilia, complicated by massive hemoptysis, is described. Bronchial artery embolization was successful in controlling the hemoptysis; however, the infection proved fatal despite appropriate antimicrobial therapy. A brief review of the literature on Job’s syndrome and its associated infective pulmonary manifestations is also presented.  相似文献   
68.
69.
Simian betaretroviruses (SRV), formerly known as simian type D retroviruses, are endemic in many populations of Asian monkeys of the genus Macaca. Asian monkeys have been used extensively as animal models for preclinical HIV vaccine development, therapeutics, and other biomedical studies. SRV infection can sometimes lead to immune deficiency disease, which complicates such studies; thus, it is important to screen for SRV infection and remove infected animals from test populations. Real-time PCR assays were developed to specifically quantify SRV-1/3, SRV-2, and SRV-5 proviral DNA. The SRV provirus copy numbers were standardized relative to real-time PCR measurements of the rhesus macaque albumin gene. The primers and TaqMan probe sequences for the rhesus macaque (Indian origin) albumin gene also detect cynomolgus macaque and rhesus macaque (Chinese origin) albumin genes. The SRV primers and probes were designed to amplify gag gene sequences of SRV-1/3 (GeneBank accession number M11841), SRV-2 (GeneBank accession number M16605), and SRV-5 (GeneBank accession number AF252389). The optimized reactions for detection of each SRV serotype and the macaque albumin gene had amplification efficiencies of greater than 90% with a linear range spanning 1 x 10(1) to 2.5 x 10(6) copies per reaction. The R(2) values of all standard curves were greater than 0.995. Of 40 animals housed in quarantine, four animals were positive for SRV-1/3 with 28, 5450, 9780, and 14,500 copies of provirus per 10(6) PBMCs, and one animal was positive for SRV-2 with provirus copy number of 7790 per 10(6) PBMCs. All of 40 animals appeared to be seronegative and had normal CD4(+) and CD8(+) T-cell counts. These quantitative real-time PCR assays enhance the detection and quantitation of SRV infection and will facilitate the elimination of this virus from macaque colonies.  相似文献   
70.
Naratriptan: biological profile in animal models relevant to migraine   总被引:2,自引:0,他引:2  
The biological profile of naratriptan (N-methyl-3-(1-methyl-4-piperidinyl)-1H-indole-5-ethane-sulphona-mide), a novel 5HT1B/1D receptor agonist, was investigated in a variety of experimental models of relevance to migraine. Naratriptan has high affinity for human recombinant 5HT1B and 5HT1D receptors (pKi = 8.70.03 and 8.30.1, respectively) and causes contractions of dog isolated basilar and middle cerebral artery (EC50 values of 0.11 and 0.07 M, respectively). Naratriptan causes small contractions of human isolated coronary arteries (EC50 value of 0.17 M; maximum contraction equivalent to 33% of 5HT maximum). In anaesthetized dogs, naratriptan causes selective vasoconstriction of the carotid arterial bed (CD50 dose = 193 g kg−1) and, in anaesthetized rats, naratriptan selectively inhibits neurogenic plasma protein extravasation in the dura (ID50 = 4.1 g kg−1). In a variety of antinociceptive tests, naratriptan has no effect even at high doses. In conscious rats and dogs, naratriptan has high oral bioavailability (71% and 95%, respectively). The data show that naratriptan is a selective agonist at 5HT1B/1D receptors, with a pharmacological profile very similar to that of sumatriptan, albeit 2-3 fold more potent. These observations, coupled with high oral bioavailability in animals, suggest that naratriptan has the profile of an orally effective anti-migraine drug.  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