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   10899篇
  免费   785篇
  国内免费   82篇
耳鼻咽喉   81篇
儿科学   257篇
妇产科学   284篇
基础医学   1473篇
口腔科学   148篇
临床医学   846篇
内科学   2922篇
皮肤病学   128篇
神经病学   1462篇
特种医学   427篇
外科学   1092篇
综合类   21篇
一般理论   3篇
预防医学   480篇
眼科学   131篇
药学   819篇
中国医学   10篇
肿瘤学   1182篇
  2024年   26篇
  2023年   170篇
  2022年   290篇
  2021年   501篇
  2020年   270篇
  2019年   387篇
  2018年   424篇
  2017年   317篇
  2016年   383篇
  2015年   405篇
  2014年   580篇
  2013年   658篇
  2012年   879篇
  2011年   937篇
  2010年   527篇
  2009年   473篇
  2008年   695篇
  2007年   639篇
  2006年   620篇
  2005年   544篇
  2004年   407篇
  2003年   349篇
  2002年   302篇
  2001年   96篇
  2000年   84篇
  1999年   94篇
  1998年   58篇
  1997年   47篇
  1996年   52篇
  1995年   34篇
  1994年   36篇
  1993年   25篇
  1992年   36篇
  1991年   52篇
  1990年   36篇
  1989年   41篇
  1988年   41篇
  1987年   29篇
  1986年   28篇
  1985年   24篇
  1984年   21篇
  1983年   21篇
  1982年   9篇
  1981年   12篇
  1980年   8篇
  1979年   20篇
  1978年   13篇
  1977年   8篇
  1976年   11篇
  1973年   11篇
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
51.
Aim: In this systematic review, guidelines on non-alcoholic fatty liver disease (NAFLD) were evaluated, aiming at a guideline synthesis focusing on diagnosis an...  相似文献   
52.
The presence of synchronous dual hematological diseases is an uncommon finding. We report an unusual case of coexistence of primary central nervous system lymphoma and primary breast lymphoma without systemic involvement in an immunocompetent patient. To our knowledge a similar case has not yet been reported in the literature. We especially focus on presenting the imaging features, the associated clinical findings and treatment management of each entity, with the aim of raising awareness on these two rare types of lymphomas and the possibility of their coexistence.  相似文献   
53.
54.
55.
56.
STUDY OBJECTIVE: To track the incidence of in-hospital postoperative nausea and vomiting (PONV) requiring postoperative parenteral nursing interventions after outpatient reconstruction of the anterior cruciate ligament (ACL) with one of two types of regional anesthesia to determine the extent to which various anesthetic techniques, preemptive antiemetics, and other factors were associated with the lowest probability of PONV. DESIGN: Retrospective chart (database) review of all ACL procedures at the University of Pittsburgh Medical Center from August 1997 through June 1999. SETTING: University medical center. MEASUREMENTS: We reviewed our institutional database of 347 consecutive patients undergoing ACL reconstruction with either spinal with femoral nerve block (SPI-FNB) or lumbar plexus and sciatic nerve block (LUM-SCI). Recorded variables and outcomes included gender, history of PONV, intravenous (i.v.) fentanyl before and during surgery, preemptive antiemetics given, and parenteral nursing interventions for PONV performed. Chi-square tests and logistic regression were used to determine factors associated with PONV. MAIN RESULTS: For SPI-FNB, PONV incidence was 13% (26/208), but it was higher for LUM-SCI [25%, 34/139, p = 0.002; odds ratio (OR) = 2.2]. Regression modeling demonstrated that women (OR = 2.8, p = 0.003) and LUM-SCI patients (OR = 3.0, p = 0.005) were at greater risk for PONV. The combination of dexamethasone (4 to 10 mg i.v.) and perphenazine (1.2 to 2.0 mg i.v.) was associated with less PONV (OR = 0.3, p = 0.005). Type of local anesthetic used for lumbar plexus block was not associated with PONV incidence. CONCLUSIONS: For ACL reconstruction with regional anesthesia, use of LUM-SCI was associated with a higher rate of PONV, whereas combination antiemetic prophylaxis with perphenazine and dexamethasone was associated with less PONV.  相似文献   
57.
BACKGROUND: Celsior is an extracellular-type, low-viscosity, preservation solution already used for heart, lung, liver, and kidney transplantation. We report the results of a single-center, prospective, randomized pilot study specifically designed to compare the safety profile of Celsior solution with University of Wisconsin (UW) solution in clinical pancreas transplantation. METHODS: A total of 105 consecutive procurements were randomized to graft preservation with UW (n=53) solution or Celsior (n=52) solution. The groups were comparable with regard to all donor and recipient characteristics. RESULTS: Five grafts were discarded and 100 grafts (50 UW vs. 50 Celsior) were transplanted. Mean cold and warm ischemia times were 11.0 +/- 2.1 hr and 37.2 +/- 6.0 min for UW compared with 10.8 +/- 1.8 hr and 38.1 +/- 5.9 min for Celsior (P =not significant). Delayed endocrine pancreas function was recorded in one graft preserved with UW solution. Eleven recipients (UW 12% vs. Celsior 10%, P =not significant) required a relaparotomy. The mean serum levels of glucose, amylase, and lipase remained comparable between the study arms at equivalent intervals after transplantation. One recipient died with functioning grafts in each study arm; two further grafts were lost to arterial thrombosis (Celsior) and chronic rejection (UW), respectively. Actuarial 1-year patient and graft survival rates overlapped in the two study arms (98% and 96%, respectively). CONCLUSIONS: Within the range of cold ischemia time reported in this study, UW and Celsior solutions have similar safety profiles for pancreas preservation.  相似文献   
58.
59.

Post–mortem computed tomography (PMCT) is a routine tool in many forensic pathology departments as it is fast and non-destructive and allows less gruesome visualization than photographs, and the images are indefinitely storable. Several studies investigated congruence between PMCT and autopsy for skull fracture but registered only the presence or absence of fracture systems. The objective of this study was to determine location-specific sensitivity and specificity of PMCT for individual fracture lines in blunt force head trauma. Accurate 3D models based on PMCT data with all fracture lines visible are important for future studies on fractures, applying finite element analysis (FEA). We retrospectively sampled adult cases from 2013 to 2019 with skull fracture mentioned in the autopsy report. PMCT was on a Siemens 64-slice scanner and autopsy according to international guidelines. The location and direction of all fracture lines at autopsy and at de novo interpretation of scans were registered and compared. Ninety-nine cases with 4809 individual findings were included. Age ranged from 18 to 100 years. The overall sensitivity was 0.58, and specificity was 0.91. For individual locations, sensitivity ranged from 0.24 to 0.85, and specificity ranged from 0.73 to 1.00. Intra-observer agreement was 0.74, and inter-observer agreement ranged from 0.43 to 0.58. In conclusion, PMCT is suited for detection of fracture systems, but not for detection of all individual fracture lines. Our results differed from the existing literature due to the methodological choices of registering individual fracture lines. Future studies utilising FEA must supplement PMCT with autopsy data.

  相似文献   
60.

Background

Information from randomized trials on the role of combination chemotherapy in the adjuvant treatment of pancreatic adenocarcinoma is limited. This randomized phase II trial aimed to identify the most promising regimen warranting phase III evaluation.

Methods

Therapy-naive patients, age 18?C75?years, Karnofsky Performance Status (KPS) >60, gross total resection of stage IB?CIII pancreatic adenocarcinoma, stratified for center and surgical margins, were randomly assigned to receive either gemcitabine 1?g/m2 weekly on days 1, 8, and 15 (arm A) or the PEFG regimen (cisplatin and epirubicin 40?mg/m2, day 1; gemcitabine 600?mg/m2, days 1, 8; 5-fluorouracil 200?mg/m2 daily, days 1?C28) (arm B). Chemotherapy was administered every 4?weeks for 3?months and followed by irradiation concurrent to continuous infusion of 5-fluorouracil 250?mg/m2 daily. Primary endpoint was the probability of being disease-free at 1?year from surgery. Assuming P0?=?35% and P1?=?55%, ???=?.05 and ???=?.10, the study was to enroll 51 patients per arm.

Results

A total of 102 patients were randomized; 100 were eligible (arm A: 51; arm B: 49). Baseline characteristic (A/B) were: Median age was 61/60?years; 75% had KPS >80 75/76%; 36% grade 3 tumor 29/43%, 79% stage IIB/III 75/84%, 31% R1 resection 35/29%. Survival figures (A/B) were: Median disease-free survival was 11.7 and 15.2?months; 1-year disease-free survival 49.0% (95% confidence interval [95% CI] 35?C63%) and 69.4% (95% CI 56?C83%); median survival 24.8 and 28.9?months. Combination chemotherapy produced more hematological toxicity without relevant differences in nonhematological toxicities.

Conclusions

The 4-drug regimen deserves further assessment in resectable pancreatic cancer.  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