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   2350293篇
  免费   169264篇
  国内免费   4744篇
耳鼻咽喉   31694篇
儿科学   73188篇
妇产科学   63128篇
基础医学   334381篇
口腔科学   70050篇
临床医学   210174篇
内科学   457178篇
皮肤病学   52143篇
神经病学   182691篇
特种医学   89401篇
外国民族医学   319篇
外科学   361688篇
综合类   52531篇
现状与发展   4篇
一般理论   734篇
预防医学   170543篇
眼科学   56099篇
药学   175351篇
  10篇
中国医学   5926篇
肿瘤学   137068篇
  2019年   17728篇
  2018年   25945篇
  2017年   19895篇
  2016年   22019篇
  2015年   25126篇
  2014年   34543篇
  2013年   50452篇
  2012年   69654篇
  2011年   73294篇
  2010年   43449篇
  2009年   40863篇
  2008年   68969篇
  2007年   73071篇
  2006年   73944篇
  2005年   70602篇
  2004年   68299篇
  2003年   65014篇
  2002年   62929篇
  2001年   125392篇
  2000年   128519篇
  1999年   106511篇
  1998年   27243篇
  1997年   23829篇
  1996年   23940篇
  1995年   22878篇
  1994年   20966篇
  1993年   19417篇
  1992年   80837篇
  1991年   77852篇
  1990年   75005篇
  1989年   72413篇
  1988年   65894篇
  1987年   64268篇
  1986年   60508篇
  1985年   57528篇
  1984年   41977篇
  1983年   35747篇
  1982年   19677篇
  1979年   37267篇
  1978年   25580篇
  1977年   21791篇
  1976年   19951篇
  1975年   21295篇
  1974年   25812篇
  1973年   24725篇
  1972年   23107篇
  1971年   21551篇
  1970年   20224篇
  1969年   18913篇
  1968年   17517篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
82.
83.
84.
Although surgical lung resection could improve prognosis in some patients with multidrug-resistant tuberculosis (MDR-TB), there are no reports on the optimal candidates for this surgery. The aim of the present study was to elucidate the prognostic factors for surgery in patients with MDR-TB. Patients who underwent lung resection for the treatment of MDR-TB between March 1993 and December 2004 were included in the present study. Treatment failure was defined as greater than or equal to two of the five cultures recorded in the final 12 months of treatment being positive, any one of the final three cultures being positive, or the patient having died during treatment. The variables that affected treatment outcomes were identified through univariate and multivariate logistic regression analysis. In total, 79 patients with MDR-TB were included in the present study. The treatment outcomes of 22 (27.8%) patients were classified as failure. A body mass index <18.5 kg x m(-2), primary resistance, resistance to ofloxacin and the presence of a cavitary lesion beyond the range of the surgical resection were associated with treatment failure. Low body mass index, primary resistance, resistance to ofloxacin and cavitary lesions beyond the range of resection are possible poor prognostic factors for surgical lung resection in multidrug-resistant tuberculosis patients.  相似文献   
85.
86.
Background Familial partial lipodystrophy (FPLD) is a monogenic form of diabetes characterised by a dominantly inherited disorder of adipose tissue associated with the loss of subcutaneous fat from the limbs and trunk, with excess fat deposited around the face and neck. The lipodystrophy causes severe insulin resistance, resulting in acanthosis nigricans, diabetes, dyslipidaemia, and increased risk of cardiovascular disease. Preliminary results from animals and man suggest that increasing subcutaneous fat by treatment with thiazolidinediones should improve insulin resistance and the associated features of this syndrome. Case report We report a 24-year-old patient with FPLD caused by a mutation in the LMNA gene (R482W) treated with 12 months of rosiglitazone. Subcutaneous fat increased following rosiglitazone treatment as demonstrated by a 29% generalised increase in skin-fold thickness. Leptin levels increased from 5.8 to 11.2 ng/ml. Compared with treatment on Metformin, there was an increase in insulin sensitivity (HOMA S% 17.2–31.6) but no change in glycaemic control. The lipid profile worsened during the follow-up period. Conclusion This initial case suggests that, for modification of cardiovascular risk factors, there are no clear advantages in treating patients with FPLD with rosiglitazone despite increases in subcutaneous adipose tissue. Larger series will be needed to identify moderate beneficial effects and treatment may be more effective in patients with generalised forms of lipodystrophy.  相似文献   
87.
88.
The purpose of this study is to determine the role of liver biopsy and outcome of patients undergoing donor evaluation for adult-to-adult right hepatic lobe living donor liver transplantation (LDLT). Records of patients presenting for a comprehensive donor evaluation between 1997 and February 2005 were reviewed. Liver biopsy was performed only in patients with risk factors for abnormal histology. Two hundred and sixty patients underwent a comprehensive donor evaluation and 116 of 260 (45%) were suitable for donation, 14 of 260 (5.4%) did not complete evaluation and 130 of 260 (50%) were rejected. Four patients underwent unsuccessful hepatectomy surgery due to discovery of intraoperative abnormalities. Between 1997 and 2001, the acceptance rate of donor candidates (63%) was higher than 2002-2005 (36%), p < 0.0001. Sixty-six of the 150 eligible patients (44%) fulfilled criteria for liver biopsy and 28 of 66 (42%) had an abnormal finding. Less than half of the patients undergoing donor evaluation were suitable donors and the donor acceptance rate has declined over time. A large proportion of the patients undergoing liver biopsy have abnormal findings. Our evaluation process failed to identify 4 of 103 who had aborted donor surgeries.  相似文献   
89.
We previously reported poorer survival among non-Hispanic blacks and Hispanics with idiopathic pulmonary fibrosis (IPF) compared to non-Hispanic whites at our center. In the current study, we hypothesized that these disparities would exist in a nationwide cohort of wait-listed patients with IPF. We performed a retrospective cohort study of 2635 patients with IPF listed for lung transplantation between 1995 and 2003 at 94 transplant centers in the United States. The age-adjusted mortality rate was higher among non-Hispanic blacks [hazard ratio (HR) = 1.24, 95% confidence interval (CI) 1.06-1.45, p = 0.009] and Hispanics (HR = 1.29, 95% CI 1.06-1.56, p = 0.01) compared to non-Hispanic whites. These findings persisted after adjustment for transplantation, medical comorbidities and socioeconomic status. Worse lung function at the time of listing appeared to explain some of these differences (HR for non-Hispanic blacks after adjustment for forced vital capacity percent predicted = 1.16, 95% CI 0.98-1.36, p = 0.09; HR for Hispanics = 1.21, 95% CI 0.99-1.48, p = 0.056). In summary, black and Hispanic patients with IPF have worse survival than whites after listing for lung transplant.  相似文献   
90.
In floating hip injuries, the priority of the steps in fixation has not been well described. We have treated these patients in accordance with the following protocols. In patients with pelvic ring fractures, the external fixation should be performed first, and in patients with acetabular fractures, the femoral fractures should be internally fixated first. The purpose of the present study was to review our experience with these fracture treatments to evaluate our strategy. For 8 years, 31 patients with femoral fractures associated with ipsilateral fractures: 26 unstable pelvic ring fractures and 7 unstable acetabular fractures were surgically treated at our level 1 trauma center. We reviewed the admission, operation, and follow-up records retrospectively and evaluated the order of the fixation and the complications. Two patients with acetabular fractures failed to follow our protocol outlined at the preoperative planning stage. There were no surgical difficulties other than two patients with the hemipelvis dislocated proximally who required traction of the fixated femur. The complications that were thought to be related to our protocol were one fat embolism syndrome and one pubic fracture displacement. One heterotopic ossification seemed to occur due to using a single approach for both fractures. We believe our protocol to be generally effective, however, in patients with acetabular and vertical shear type pelvic ring fractures, the internal or external fixation of the femur should be performed before the internal fixation of the pelvis.  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