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   668篇
  免费   18篇
耳鼻咽喉   6篇
儿科学   29篇
妇产科学   29篇
基础医学   40篇
口腔科学   9篇
临床医学   62篇
内科学   193篇
皮肤病学   17篇
神经病学   18篇
特种医学   70篇
外科学   76篇
综合类   19篇
预防医学   55篇
眼科学   17篇
药学   29篇
中国医学   3篇
肿瘤学   14篇
  2022年   8篇
  2021年   24篇
  2020年   10篇
  2019年   8篇
  2018年   15篇
  2017年   11篇
  2016年   8篇
  2015年   9篇
  2014年   17篇
  2013年   15篇
  2012年   29篇
  2011年   31篇
  2010年   14篇
  2009年   14篇
  2008年   34篇
  2007年   39篇
  2006年   44篇
  2005年   36篇
  2004年   43篇
  2003年   18篇
  2002年   19篇
  2001年   11篇
  2000年   16篇
  1999年   7篇
  1998年   3篇
  1997年   6篇
  1996年   3篇
  1993年   3篇
  1992年   15篇
  1991年   16篇
  1990年   13篇
  1989年   18篇
  1988年   18篇
  1987年   19篇
  1986年   13篇
  1985年   11篇
  1984年   6篇
  1983年   8篇
  1982年   3篇
  1981年   7篇
  1980年   3篇
  1979年   4篇
  1978年   3篇
  1977年   4篇
  1975年   4篇
  1972年   3篇
  1970年   2篇
  1969年   2篇
  1967年   7篇
  1966年   3篇
排序方式: 共有686条查询结果,搜索用时 15 毫秒
1.
2.
In three patients the diagnosis of sacral osteomyelitis was made when CT demonstrated intraosseous (two) and intraforaminal (one) gas. Two of the three patients also had radionuclide bone scans, one of which was unremarkable. In the other case, radionuclide scintigraphy greatly underestimated the extent of the disease process when compared with CT. All three patients had contiguous pelvic abscesses as a cause of the osteomyelitis. Although there was a high clinical suspicion for an intraabdominal process, the diagnosis of superimposed osteomyelitis of the sacrum was unsuspected. The detection of intraosseous gas is a pathognomonic, albeit uncommon, manifestation of osteomyelitis. Although the radionuclide bone scan is the method of choice for detecting osteomyelitis, CT should be used as a complementary study in certain patients.  相似文献   
3.
OBJECTIVE: To clarify the role played by tissue factor pathway inhibitor (TFPI) in pregnancy hypertension. METHODS: Using enzyme-linked immunosorbent assays, hemostatic measurements were obtained for women with pre-eclampsia (n=51), nonproteinuric hypertension of pregnancy (n=62), postpartum pre-eclampsia 24 h after childbirth (n=31), and no hypertension (healthy pregnant controls, n=100). RESULTS: There was a significant increase in circulating free TFPI levels in women with pre-eclampsia (9.7+/-6.2 ng/mL) or nonproteinuric hypertension of pregnancy (8.3+/-5.3 ng/mL) compared with healthy controls (5.3+/-2.1 ng/mL). In women with pre-eclampsia the levels remained elevated after placental delivery (10.6+/-4.0 ng/mL). Free protein S levels were significantly higher in women with pre-eclampsia (40.0%+/-10.7%), nonproteinuric hypertension of pregnancy (37.1%+/-12.5%), or postpartum pre-eclampsia (39.3%+/-9.1%) than in healthy pregnant controls (32.2%+/-8.5%). CONCLUSION: Increased levels of the physiologically active free forms of TFPI and free protein S, 2 coagulation inhibitors, may protect women with pregnancy-induced hypertension from the risks of hemostatic activation.  相似文献   
4.
Nineteen normal subjects were studied before and after pancreatic stimulation. Duodenal flow was quantitated by means of a dilution indicator technique, and the secretion pattern of lactoferrin, amylase, total bile acids, and bicarbonate was studied. Output of lactoferrin in the duodenum was increased both after stimulation with a test meal and after hormonal stimulation by cholecystokinin alone or cholecystokinin in combination with secretin. Output of lactoferrin was not affected by stimulation by secretin alone. Lactoferrin was secreted in parallel with amylase and bile acids. The results indicate that the origin of lactoferrin in duodenum can be bile or pancreatic juice, or a combination of these.  相似文献   
5.
We report a case of an infantile myofibromatosis with hemangiopericytoma-like features arising in the tongue of a 5-month-old female infant. Many authors now classify neoplasms as infantile myofibromatosis that were previously called infantile hemangiopericytoma. The ultrastructural features of our tumor illustrate its biphasic nature and provide a possible explanation for its histogenesis. Infantile myofibromatosis, including those diagnosed as infantile hemangiopericytomas, rarely arise in any intraoral location. Despite the generally good prognosis associated with these neoplasms, complete surgical excision is recommended to avoid recurrences.  相似文献   
6.
As a multifactorial disease and with the need of primordial prevention coronary heart disease (CHT), a risk scoring system for the prediction of CHD was devised at Community Medicine Department Ain Shams University, Cairo, EGYPT. In this matched case-control study of 119 cases and 121 age and sex matched controls, current cigarette smoking, lack of siesta, hypertension, diabetes mellitus, low occupational physical activity, hypercholesterolemia, marital status, urban residence, level of education, work index, coffee consumption, positive family history, BMI, elevated W/H ratio, low HDL and elevated TC/HDL were studied for association with CHD. The additive risk scoring system based on the results of conditional multiple logistic regression identified the first six factors with statistical weights of 1, 5, 10, 6, 6, 11, respectively. On back validation receiver operating characteristic (ROC) curve, a total score of 17 was found to be the cut off point above which there was increased risk of CHD. The overall predictive accuracy of this system--equivalent to the area under the ROC curve--was 0.873. Future studies need to assess the risk scoring system in population based studies.  相似文献   
7.
PURPOSE: To determine incidence of non-AIDS-defining cancers (NADC) in HIV-infected patients before (P1) and during (P2) the use of highly active antiretroviral therapy (HAART) relative to that observed in the French general population (FGP) of the same age and sex. PATIENTS AND METHODS: Sex- and age-adjusted NADC standardized incidence ratios (SIR), with FGP as reference, were estimated in 1992 to 1995 (P1) and in 1996 to 1999 (P2) in a French Hospital Database on HIV prospective hospital cohort study. RESULTS: NADCs were diagnosed in 260 patients during P1 and 391 patients during P2 among the 77,025 patients included in the database between January 1, 1992, and December 31, 1999. Estimated incidence of all cancers was higher in HIV-infected men than in FGP during both periods (P1 SIR = 2.36 and P2 SIR = 1.91). No excess of cancers was observed among HIV-infected women in either period. Incidence of all cancers did not change from P1 to P2 in either sex (SIR = 0.96 for men and 1.00 for women). In contrast, incidence of Hodgkin's disease (HD) was higher than in FGP in both sexes and both periods and increased in P2 as compared with P1; incidence of lung cancer was higher in both sexes during P2. CONCLUSION: Relative to FGP, the overall incidence of NADCs was increased in HIV-infected men but not in women and did not differ between P1 and P2. Only HD was much more common in HIV infection, and the potential role of HAART on HD cannot be excluded.  相似文献   
8.
OBJECTIVE: We determined the relative value of teleradiology and radiology resident coverage of the emergency department by measuring and comparing the effects of physician specialty, training level, and image display method on accuracy of radiograph interpretation. MATERIALS AND METHODS: A sample of four faculty emergency medicine physicians, four emergency medicine residents, four faculty radiologists, and four radiology residents participated in our study. Each physician interpreted 120 radiographs, approximately half containing a clinically important index finding. Radiographs were interpreted using the original films and high-resolution digital monitors. Accuracy of radiograph interpretation was measured as the area under the physicians' receiver operating characteristic (ROC) curves. RESULTS: The area under the ROC curve was 0.15 (95% confidence interval [CI], 0.10-0.20) greater for radiologists than for emergency medicine physicians, 0.07 (95% CI, 0.02-0.12) greater for faculty than for residents, and 0.07 (95% CI, 0.02-0.12) greater for films than for video monitors. Using these results, we estimated that teleradiology coverage by faculty radiologists would add 0.09 (95% CI, 0.03-0.15) to the area under the ROC curve for radiograph interpretation by emergency medicine faculty alone, and radiology resident coverage would add 0.08 (95% CI, 0.02-0.14) to this area. CONCLUSION: We observed significant differences between the interpretation of radiographs on film and on digital monitors. However, we observed differences of equal or greater magnitude associated with the training level and physician specialty of each observer. In evaluating teleradiology services, observer characteristics must be considered in addition to the quality of image display.  相似文献   
9.
Endoscopy in children with recurrent abdominal pain   总被引:1,自引:0,他引:1  
  相似文献   
10.
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