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   332篇
  免费   31篇
  国内免费   27篇
耳鼻咽喉   1篇
儿科学   20篇
妇产科学   3篇
基础医学   44篇
口腔科学   18篇
临床医学   50篇
内科学   72篇
皮肤病学   8篇
神经病学   6篇
特种医学   25篇
外科学   87篇
综合类   18篇
预防医学   7篇
药学   15篇
中国医学   1篇
肿瘤学   15篇
  2022年   2篇
  2021年   2篇
  2020年   2篇
  2019年   3篇
  2018年   6篇
  2017年   8篇
  2016年   9篇
  2015年   7篇
  2014年   7篇
  2013年   14篇
  2012年   10篇
  2011年   7篇
  2010年   13篇
  2009年   13篇
  2008年   14篇
  2007年   17篇
  2006年   10篇
  2005年   15篇
  2004年   11篇
  2003年   9篇
  2002年   11篇
  2001年   12篇
  2000年   6篇
  1999年   11篇
  1998年   23篇
  1997年   18篇
  1996年   18篇
  1995年   13篇
  1994年   14篇
  1993年   4篇
  1992年   6篇
  1991年   5篇
  1990年   3篇
  1989年   10篇
  1988年   5篇
  1987年   6篇
  1986年   12篇
  1985年   6篇
  1982年   2篇
  1981年   3篇
  1980年   4篇
  1979年   1篇
  1978年   3篇
  1977年   3篇
  1976年   4篇
  1975年   3篇
  1973年   1篇
  1972年   1篇
  1968年   1篇
  1954年   1篇
排序方式: 共有390条查询结果,搜索用时 15 毫秒
61.
62.
Liver surgery for the treatment of colorectal liver metastases is the standard treatment in a dynamic surgical field with many variables that should be considered in a curative intent scenario. Hepatectomy for colorectal liver metastases has undergone constant changes over the last 30 years, including indications until the need for rescue procedures of recurrent and advanced diseases as well as minimally invasive surgery. These advancements in liver surgery have not only resulted from overall improvements in the surgical field but have also resulted from a better understanding of the biological behavior of the disease, liver regeneration, and homeostasis during and after surgery.Improvements in anesthesiology, intensive care medicine, radiology, and surgical devices have correlated with further advancements of hepatectomies. Moreover,changes are still forthcoming, and both fields of augmented reality and artificial intelligence will likely have future contributions in this field in regard to both diagnoses and the planning of procedures. The aim of this editorial is to emphasize several aspects that have contributed to the paradigm shifts in colorectal liver metastases surgery over the last three decades as well as to discuss the factors concerning patient selection and the technical aspects of liver surgery. Finally, this editorial will highlight the promising new features of this surgery for diagnoses and treatments in this field.  相似文献   
63.
64.

Background  

Allograft bone used in joint replacement surgery can additionally serve as a carrier for antibiotics and serve as a prophylaxis against infections. However, in vitro dose-response curves for bone chips impregnated with different kinds of antibiotics are not available. In addition, while it would be desirable to add the antibiotics to allograft bone chips before these are stored in a bone bank, the effects of different storage temperatures on antibiotics are unknown.  相似文献   
65.
66.
67.
Objective  To compare urinary placental growth factor (PlGF) concentration at 11+0 to 13+6 weeks of gestation in women who subsequently develop pre-eclampsia with normotensive controls.
Design  Nested case–control study within a prospective study for first trimester prediction of pre-eclampsia.
Setting  Routine antenatal visit in a teaching hospital.
Population  Fifty-two women who developed pre-eclampsia and 52 controls matched for gestational age and sample storage time.
Methods  Urinary PlGF concentration and PlGF to creatinine ratio were measured in women who developed pre-eclampsia and their matched controls. Comparisons between groups were performed using Student's t test.
Main outcome measures  Development of pre-eclampsia.
Results  In the pre-eclampsia group, the median urinary PlGF concentration (20.6 pg/ml, interquartile range [IQR] 9.1–32.0 pg/ml) and median urinary PlGF to creatinine ratio (1.6 pg/mg, IQR 1.2–2.5 pg/mg) were not significantly different from the control group (11.8 pg/ml, IQR 5.5–29.8 pg/ml, P = 0.1 and 1.7 pg/mg, IQR 1.2–2.3 pg/mg, P = 0.3, respectively). There were no significant differences between women with early-onset pre-eclampsia requiring delivery before 34 weeks ( n = 13) and those with late-onset pre-eclampsia ( n = 39) and between women with pre-eclampsia and fetal growth restriction (FGR) ( n = 25) and those with pre-eclampsia and no FGR ( n = 27) in either median PlGF concentration or median urinary PlGF to creatinine ratio.
Conclusions  The development of pre-eclampsia is not preceded by altered urinary PlGF concentration in the first trimester of pregnancy.  相似文献   
68.
SarCNU在MGMT耐药基因高表达荷瘤鼠中抗瘤作用分析   总被引:5,自引:0,他引:5  
目的 2-氯乙基-3-肌氨酸酰胺-1-亚硝脲(SarCNU)是一类新型亚硝脲类抗癌药,探讨其对MGMT耐药基因高表达胶质瘤的疗效。方法 腹腔注射SarCNU(500mg/m^2),BCNU(40mg/m^2),O^6-BG(300mg/m^2),观察其在动物体内胶质瘤的生长情况。结果 SarCNU处理组生长缓延34.7天,BCNU组生长延缓20.75天,差异有显著性,SarCNU与O^6-BG联合  相似文献   
69.
The mechanism of clinical cyclosporine nephrotoxicity has remained unclear. We have established an animal model of cyclosporine-induced acute renal failure in the male Munich-Wistar rat by giving four daily doses of parenteral cyclosporine 60 mg/kg intraperitoneally (IP). In this model, 20 minutes of bilateral renal ischemia preceding the first cyclosporine dose did not significantly increase the renal failure, but did increase mortality (65% v 17%), which was due in part to the CNS effect of cyclosporine. Pair-fed and pair-watered vehicle and saline controls were used. The renal morphologic changes induced by the castor oil vehicle of the commercial parenteral cyclosporine solution were quantitatively similar to those induced by cyclosporine, although the severity of the changes by light microscopy was considerably less in the vehicle-treated groups. However, by electron microscopy, pale lipid vacuoles were seen only in the cyclosporine-treated groups, whereas dense alterations in lysosomes and dilated endoplasmic reticulum were also seen in other groups. Renal blood flow determined by electromagnetic flow probe showed a significant decline during 2 hours after a single IP injection of cyclosporine (6.6 +/- 0.4 to 5.0 +/- 0.6 mL/min). A similar decline was seen following injection of the castor oil vehicle of the commercial cyclosporine parenteral preparation (6.6 +/- 0.5 to 5.1 +/- 0.5 mL/min), but not after an injection of a similar volume of mineral oil (6.7 +/- 0.3 to 6.3 +/- 0.2 mL/min). These studies suggest that brief renal ischemia does not increase cyclosporine nephrotoxicity significantly in this rat model.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
70.
To assess the prognostic significance of the growth fraction in diffuse large cell lymphoma (DLCL), we studied 105 DLCL patients with the monoclonal antibody Ki-67 applied to frozen tissue sections. Ki-67 detects a nuclear antigen associated with cell proliferation not found in resting cells. Ki-67 findings and other clinical prognostic factors were correlated with outcome using univariate and multivariate analyses in the proportional hazards model. High proliferative activity, defined as nuclear Ki-67 expression in greater than 60% of malignant cells (Ki- 67 greater than 60), was found to be a strong predictor of poor survival among these patients (P = .003, log-rank). The 19 patients with Ki-67 greater than 60% had a median survival of 8 months compared with a median survival of 39 months for the 86 patients with Ki-67 less than or equal to 60%. Examination of pretreatment clinical variables indicated the patient groups were similar with regard to age, sex, stage, B symptoms, tumor bulk, and lactate dehydrogenase (LDH). Both patient groups received comparable curative intent therapy and showed comparable complete response rate precluding treatment differences as modifying outcome. Multivariate analysis indicated Ki-67 is an independent predictor of survival (multivariate P = .006). Further statistical analysis using only B-cell DLCL patients treated with CHOP (63 patients) indicated that Ki-67 greater than 60 retained strong prediction of poor outcome (P = .002, log-rank) among this homogeneous group. We conclude that high proliferative activity (Ki-67 greater than 60) is an independent factor allowing laboratory prediction of probable poor outcome of DLCL.  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