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   43228篇
  免费   3237篇
  国内免费   577篇
耳鼻咽喉   482篇
儿科学   1164篇
妇产科学   712篇
基础医学   6284篇
口腔科学   708篇
临床医学   3976篇
内科学   9218篇
皮肤病学   956篇
神经病学   3184篇
特种医学   1893篇
外国民族医学   18篇
外科学   5489篇
综合类   1440篇
现状与发展   1篇
一般理论   2篇
预防医学   3258篇
眼科学   896篇
药学   3335篇
  7篇
中国医学   777篇
肿瘤学   3242篇
  2023年   346篇
  2022年   918篇
  2021年   1471篇
  2020年   854篇
  2019年   1105篇
  2018年   1300篇
  2017年   952篇
  2016年   1061篇
  2015年   1307篇
  2014年   1643篇
  2013年   2051篇
  2012年   3043篇
  2011年   2951篇
  2010年   1738篇
  2009年   1488篇
  2008年   2159篇
  2007年   2105篇
  2006年   2018篇
  2005年   1841篇
  2004年   1669篇
  2003年   1601篇
  2002年   1457篇
  2001年   1294篇
  2000年   1269篇
  1999年   1134篇
  1998年   423篇
  1997年   350篇
  1996年   309篇
  1995年   250篇
  1994年   231篇
  1993年   200篇
  1992年   550篇
  1991年   542篇
  1990年   499篇
  1989年   461篇
  1988年   482篇
  1987年   406篇
  1986年   396篇
  1985年   396篇
  1984年   275篇
  1983年   208篇
  1982年   134篇
  1981年   116篇
  1979年   228篇
  1978年   123篇
  1977年   131篇
  1976年   124篇
  1974年   139篇
  1972年   135篇
  1970年   110篇
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
51.
52.
The authors report 3 cases of slowly progressive aphasia with different language disturbances: anomia, pure word deafness and Broca's aphasia. All patients were independent in daily life activities. Insight, judgement and overall behaviour were intact. There was no major disturbance of other cognitive functions, but psychometric tests showed mild deficits suggesting widespread involvement. CT scans and magnetic resonance imaging showed focal dilatation of the left sylvian fissure. A positron emission tomographic study showed left perisylvian hypometabolism. A review of the literature yielded an increasing number of cases of this degenerative syndrome affecting dominant hemisphere language areas. Our cases confirm the clinical heterogeneity of degenerative aphasia. Postmortem neuropathological examinations are rare and many causes are found: Pick's disease, Alzheimer's disease or aspecific gliosis.  相似文献   
53.
54.
55.
56.
We studied 54 patients who, after small intestinal resection, developed a massive protracted diarrhea with a daily fecal loss greater than 2 kg, status we defined as the "overwhelmed intestine syndrome" (OIS). Median length of residual small bowel was 120 cm, 19 patients had a definitive stoma (jejunostomy, n = 9; colostomy, n = 10), 26 patients had a provisional jejunostomy. Fecal weight greater than 2 kg was related to enteral hyperalimentation (greater than 3,500 Kcal) in 19 patients (induced OIS) and was clearly independent in 16 others who had fecal weight over 3 kg while receiving approximately 2,000 Kcal (obligatory OIS); the last 19 patients had fecal weight between 2 and 3 kg during normoalimentation. Hypocalcemia and hypomagnesemia were common in the three groups. The other complications were seen mostly in patients with obligatory OIS: in those patients, parenteral nutrition was maintained in 9 cases out of 16 (vs. 0 in other groups), nutritional gain was scanty, sodium equilibrium was difficult to obtain in spite of a large sodium intake (380 mmol/day), hospitalization lasted several months and autonomy via the enteral route could not be achieved in 7 out of the 9 patients with definitive short bowel (vs. 0 in other groups). This study shows that the OIS is an unique functional entity. Complications and prognosis are dependent on the obligatory or induced pattern of the syndrome. Only patients with obligatory OIS require definitive home parenteral nutrition.  相似文献   
57.
A retrospective study of 2498 patients who made multiple visits to a sexually transmitted disease clinic over a 13-year period analyzed risk factors, default patterns, and repeated infections associated with gonococcal urethritis. An analysis of visitation patterns found that being young, black, and male and having a history of gonococcal urethritis before visiting the clinic was positively related to the total time a patient remained involved with the clinic. Default rates for all patients increased with successive clinic visits. A focused analysis was carried out on the records of 146 patients who returned to the clinic within 12 months with a second diagnosis of gonococcal urethritis. It was found that this group of "repeaters," who comprised 15% of the total population with gonococcal urethritis, accounted for approximately 29% of all diagnoses of this infection over the 13-year study period. Repeaters were found to be more frequently male, black, single, and to be less likely to return for a test-of-cure culture. Longitudinal analysis found that the median time repeaters remained involved with the clinic was approximately 130 days. The relatively brief clinic "half-life" and rapid rates of removal of repeaters are discussed in terms of the development of strain-specific immunity to Neisseria gonorrhoeae in a closed population of patients.  相似文献   
58.
OX39, a murine IgG1 monoclonal antibody (MoAb) that recognizes the 55 kDa alpha chain of the rat interleukin 2 receptor (R-IL2), was studied in vitro for its ability to interfere with IL2 binding and IL2-induced proliferation on rat concanavalin A (ConA) blasts and in vivo in a model of rat heart allografts. In vitro studies indicated that OX39 MoAb interacts with a single class of sites on the alpha chain of the rat R-IL2 with a high affinity (KD=0.8 nm) and competes with IL2 binding on this chain (KI=0.53 nm). In contrast, OX39 MoAb was found to be 10–20 times less efficient in competing with IL2 binding to the high-affinity R-IL2 (KI10 nm). It is proposed that the epitope recognized by OX39 on the alpha chain (low-affinity R-IL2) is modified on (or buried in) the high-affinity R-IL2 configuration. Accordingly, OX39 was found to be a weak inhibitor in vitro on IL2-induced proliferation and in vivo on allograft rejection. Allograft survival was unaffected by doses of OX39 of 20 and 50 g/rat for 9 days; only a borderline effect was noted when doses as high as 250 g/rat were used. A significant, but restricted, effect of OX39 could be further detected when combined with low doses of cyclosporine A (1.5 mg/kg), which were ineffective by themselves. Together, our data suggest that in order to be efficient in vivo, anti-R-IL2 MoAbs must bind with high affinity to epitopes involved in the high-affinity IL2 binding site.  相似文献   
59.
Solitary plasmacytoma of the spine. Long-term clinical course   总被引:6,自引:0,他引:6  
The data for 19 patients with solitary plasmacytoma of the spine were reviewed with regard to clinical course and prognosis (median follow-up, 96 months). Eight patients presented with spinal cord compression. A monoclonal immunoglobulin was initially detected in seven of 15 evaluable patients. Treatment included radiotherapy (18 of 19) and/or surgery (11 of 19) and chemotherapy (eight of 19). Spinal cord compression was reversed in every patient. The expected survival rate was 85% at 10 years after diagnosis. Local recurrence or dissemination was observed in 13 patients. It occurred within 5 years of diagnosis in 11 patients and was localized (that is, local recurrence or single bone metastasis) in eight patients. It was always associated with the appearance or an increase of the M component. Dissemination frequently had a "metastatic" pattern with no diffuse bone marrow plasmacytosis. The incidence of local recurrence (five patients) and leukemia (four patients) was high. Local recurrence and/or dissemination were significantly more frequent in patients with the M component at diagnosis than in those without it (P less than 0.05; relative risk, R = 4). The effectiveness of surgery and chemotherapy combined with radiotherapy is also discussed.  相似文献   
60.
Spectrum of NSD1 mutations in Sotos and Weaver syndromes   总被引:8,自引:0,他引:8  
Interestingly, mental retardation was consistently more severe in patients with NSD1 deletions. Macrocephaly and facial gestalt but not overgrowth and advanced bone age were consistently observed in Sotos syndrome patients. We suggest therefore considering macrocephaly and facial gestalt as mandatory criteria for the diagnosis of Sotos syndrome and overgrowth and advanced bone age as minor criteria.  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