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   5076篇
  免费   296篇
  国内免费   27篇
耳鼻咽喉   31篇
儿科学   193篇
妇产科学   99篇
基础医学   755篇
口腔科学   69篇
临床医学   350篇
内科学   839篇
皮肤病学   92篇
神经病学   304篇
特种医学   175篇
外科学   551篇
综合类   373篇
一般理论   4篇
预防医学   368篇
眼科学   155篇
药学   536篇
中国医学   71篇
肿瘤学   434篇
  2023年   29篇
  2022年   77篇
  2021年   102篇
  2020年   78篇
  2019年   99篇
  2018年   126篇
  2017年   86篇
  2016年   104篇
  2015年   150篇
  2014年   163篇
  2013年   251篇
  2012年   328篇
  2011年   332篇
  2010年   242篇
  2009年   186篇
  2008年   265篇
  2007年   252篇
  2006年   309篇
  2005年   234篇
  2004年   216篇
  2003年   154篇
  2002年   163篇
  2001年   112篇
  2000年   117篇
  1999年   88篇
  1998年   79篇
  1997年   76篇
  1996年   67篇
  1995年   49篇
  1994年   45篇
  1993年   25篇
  1992年   60篇
  1991年   57篇
  1990年   49篇
  1989年   62篇
  1988年   52篇
  1987年   40篇
  1986年   36篇
  1985年   42篇
  1984年   37篇
  1983年   34篇
  1982年   21篇
  1981年   20篇
  1980年   21篇
  1979年   31篇
  1978年   20篇
  1977年   25篇
  1976年   15篇
  1974年   16篇
  1972年   15篇
排序方式: 共有5399条查询结果,搜索用时 31 毫秒
101.
102.
103.
104.
Rheologic predictors of the severity of the painful sickle cell crisis   总被引:4,自引:0,他引:4  
Ballas  SK; Larner  J; Smith  ED; Surrey  S; Schwartz  E; Rappaport  EF 《Blood》1988,72(4):1216-1223
Deformable sickle erythrocytes have been reported by Mohandas and Evans to be more adherent to vascular endothelium than rigid irreversibly sickled cells (ISC). To define the clinical implications of this finding we have determined genetic, hematological, clinical, and rheological characteristics of sickle erythrocytes obtained from 65 patients with sickle cell anemia and fetal hemoglobin (Hb F) levels less than 15%. The alpha-globin gene number had a significant effect on the hematological parameters, the percentage of dense cells, ISC number, and HB A2 levels. The presence or absence of alpha thalassemia, however, had no effect on the frequency and severity of the sickle cell painful crisis (r = 0.06, P greater than .05). RBC deformability, determined by an ektacytometer, showed great heterogeneity among patients with three or four alpha-globin genes. Linear regression analyses of the data showed significant positive correlation of the frequency and severity of the painful crisis with RBC deformability (r = 0.49, P less than .001), and negative correlations with the percentage of dense cells (r = -0.37, P = .002), and the percentage of ISC (r = -0.46, P less than .001). We propose that the more deformable the sickle RBC are, the greater their adherence to vascular endothelium, and the more they cause vaso-occlusive crises, RBC deformability and the percentage of dense cells (or ISC) seem to have a predictive value of the frequency and severity of painful crises in sickle cell anemia.  相似文献   
105.
106.

Background

The accurate diagnosis of abdominal tuberculosis usually takes a long time and requires a high index of suspicion in clinic practice. Eighty-eight immune-competent patients with abdominal tuberculosis were grouped according to symptoms at presentation and followed prospectively in order to investigate the effect of symptomatic presentation on clinical diagnosis and prognosis.

Methods

Based upon the clinical presentation, the patients were divided into groups such as non-specific abdominal pain & less prominent in bowel habit, ascites, alteration in bowel habit, acute abdomen and others. Demographic, clinical and laboratory features, coexistence of pulmonary tuberculosis, diagnostic procedures, definitive diagnostic tests, need for surgical therapy, and response to treatment were assessed in each group.

Results

According to clinical presentation, five groups were constituted as non-specific abdominal pain (n = 24), ascites (n = 24), bowel habit alteration (n = 22), acute abdomen (n = 9) and others (n = 9). Patients presenting with acute abdomen had significantly higher white blood cell counts (p = 0.002) and abnormalities in abdominal plain radiographs (p = 0.014). Patients presenting with alteration in bowel habit were younger (p = 0.048). The frequency of colonoscopic abnormalities (7.5%), and need for therapeutic surgery (12.5%) were lower in patients with ascites, (p = 0.04) and (p = 0.001), respectively. There was no difference in gender, disease duration, diagnostic modalities, response to treatment, period to initial response, and mortality between groups (p > 0.05). Gastrointestinal tract alone was the most frequently involved part (38.5%), and this was associated with acid-fast bacteria in the sputum (p = 0.003).

Conclusion

Gastrointestinal tract involvement is frequent in patients with active pulmonary tuberculosis. Although different clinical presentations of patients with abdominal tuberculosis determine diagnostic work up and need for therapeutic surgery, evidence based diagnosis and consequences of the disease does not change.  相似文献   
107.
108.
Response     
  相似文献   
109.
Tubercular liver abscess is a rare entity even in an endemic area for TB. We report here a rare case of pediatric tuberculous liver abscess, the etiology of which was established using recently introduced Cartridge based nucleic acid amplification test (CBNAAT). A 7 years old male child presented with vomiting, pain abdomen and fever. Hepatomegaly was found on examination. Ultrasound of abdomen revealed two liver abscesses in the right lobe. Patient remained symptomatic even after empirical antimicrobial therapy. On diagnostic tap Gram stained smear of the pus showed polymorphs with negative culture. CBNAAT was positive for Mycobacterial tuberculosis and sensitive to rifampicin. Subjecting difficult extrapulmonary specimens to relevant microbiological investigations along with CBNAAT and other newer methods may improve diagnosis of tuberculosis in such rare cases thus leading to an early management and decrease in morbidity.  相似文献   
110.
GeroScience - The neuroprotective effects of pituitary adenylate cyclase-activating polypeptide (PACAP) have been shown in numerous in vitro and in vivo models of Parkinson’s disease (PD)...  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