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   29012篇
  免费   2583篇
  国内免费   55篇
耳鼻咽喉   304篇
儿科学   995篇
妇产科学   784篇
基础医学   4245篇
口腔科学   478篇
临床医学   3777篇
内科学   5503篇
皮肤病学   450篇
神经病学   2619篇
特种医学   683篇
外国民族医学   1篇
外科学   3434篇
综合类   349篇
一般理论   35篇
预防医学   3257篇
眼科学   489篇
药学   2062篇
中国医学   25篇
肿瘤学   2160篇
  2023年   211篇
  2022年   357篇
  2021年   705篇
  2020年   490篇
  2019年   750篇
  2018年   829篇
  2017年   675篇
  2016年   747篇
  2015年   736篇
  2014年   1034篇
  2013年   1391篇
  2012年   1965篇
  2011年   2002篇
  2010年   1064篇
  2009年   969篇
  2008年   1581篇
  2007年   1629篇
  2006年   1591篇
  2005年   1574篇
  2004年   1381篇
  2003年   1181篇
  2002年   1094篇
  2001年   515篇
  2000年   553篇
  1999年   488篇
  1998年   285篇
  1997年   213篇
  1996年   210篇
  1995年   190篇
  1994年   189篇
  1993年   172篇
  1992年   331篇
  1991年   354篇
  1990年   356篇
  1989年   368篇
  1988年   279篇
  1987年   293篇
  1986年   249篇
  1985年   303篇
  1984年   208篇
  1983年   172篇
  1982年   137篇
  1981年   111篇
  1980年   107篇
  1979年   176篇
  1978年   133篇
  1977年   112篇
  1975年   105篇
  1974年   125篇
  1973年   111篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.

Background

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemoperfusion (HIPEC) are frequently used to treat appendiceal carcinomatosis. Some patients require multivisceral resection because of the volume of disease. It is unclear whether extent of CRS impacts survival in appendiceal carcinomatosis.

Methods

We analyzed 282 patients undergoing attempted CRS/HIPEC for appendiceal carcinomatosis. Patients were defined as having undergone Extensive CRS (n = 60) if they had >3 organ resections or >2 anastomoses; a subgroup of Extreme CRS patients (n = 10) had ≥5 organ resections and ≥3 anastomoses. Kaplan–Meier survival curves and multivariate Cox-regression models were used to identify prognostic factors affecting outcomes.

Results

Relative to the comparison group, patients undergoing Extensive CRS had a higher median peritoneal carcinomatosis index, operative duration, blood loss, and length of stay. No difference in completeness of cytoreduction, severe morbidity, or 60-day mortality was evident. Subgroup analysis of 10 patients undergoing extreme CRS likewise revealed no increase in severe morbidity or mortality. Median progression-free (PFS) and overall survival (OS) were 23.5 and 74 months in the comparison group; 18.5 (p = 0.086) and 51 (p = 0.85) months in the Extensive CRS group; and 40 months and not reached in the Extreme CRS subgroup. In a multivariable analysis, extent of CRS was not independently associated with PFS or OS.

Conclusions

Extensive CRS is associated with greater OR time, blood loss, and length of stay, but is not associated with higher morbidity, mortality, or inferior oncologic outcomes in patients with appendiceal carcinomatosis.  相似文献   
972.
973.
ObjectivesIn this nationwide retrospective study, we analysed species distribution, antimicrobial susceptibility and time to next occurrence of Achromobacter in Danish cystic fibrosis (CF) patients from 2000 to 2011.MethodsThirty-four primary isolates were identified to species level and subjected to antimicrobial susceptibility testing. Effectiveness of early antimicrobial treatment was assessed by a Kaplan–Meier estimation of time to recurrence.ResultsAchromobacter xylosoxidans accounted for 13 (38%) of the isolates, and an unnamed species accounted for 11 (32%) of the isolates. Meropenem, piperacillin–tazobactam and trimethoprim–sulfamethoxazole were highly active against chemotherapy-naïve Achromobacter, while ceftazidime, colistin and tobramycin were judged adequate for inhalation therapy. Fifty-five percent of 25 patients treated with inhaled ceftazidime, colistin, or tobramycin remained free of Achromobacter three years after acquisition, in contrast to 17% of 22 patients who did not receive inhaled antibiotics (P < 0.01).ConclusionsEarly treatment with inhaled antibiotics may prevent or postpone chronic infection with Achromobacter in CF patients.  相似文献   
974.
975.
976.
977.
978.
Abstract

Pathologic fractures may occur with minimal trauma after spinal cord injury (SCI) because of osteoporosis. Rats were evaluated to determine whether they could be used as an SCI animal model. Male Sprague-Dawley rats underwent spinal cord transection at the ninth thoracic vertebrae. Control rats underwent a sham procedure. Mechanical testing of the humeral shaft, femoral shaft, tibial shaft, femoral neck, distal femur, and proximal tibia was performed separately at 0, 8, and 24 weeks after surgery. At 24 weeks, significant differences between SCI and control rats were found in maximum torque needed to produce failure in the femoral shaft (63 percent of control, p < 0.05) and tibial shaft (63 percent, p < 0.01), and in compressive load to produce failure in cross-sectional specimens of the distal femur (51 percent, p < 0.05) and proximal tibia (50 percent, p < 0.01 ). No differences were found in the maximum torque needed to produce failure of the humeral shaft (106 percent, p = 0.77) between SCI and control rats. Reductions in relative bone strength in SCI rats at 24 weeks were similar in magnitude to bone mineral density changes reported in humans with chronic paraplegia. Thus, Sprague-Dawley rats appear to be good animal models in which to evaluate changes in bone strength following SCI. U Spinal Cord Med 1998; 21:302-308)  相似文献   
979.
The aim of this study was to evaluate the outcome of primary percutaneous transluminal coronary angiography (PTCA) in the treatment of acute myocardial infarction (AMI) The study included patients with electrocardiographic signs of transmural AMI, symptom duration of less than 12 h, and with no contraindications to thrombolytic therapy. Patients who had undergone primary PTCA were matched consecutively, for age, gender, infarct localization and duration of symptoms, to patients who had received thrombolytic therapy (82 patients to each group). Patients who were admitted to hospital during daytime had a primary PTCA, whereas those admitted outside daytime were given thrombolytic therapy. In the primary PTCA group, 9 patients had a combined endpoint compared with 22 patients in the thrombolysis group (p &lt; 0.02 ). In-hospital mortality was 3.7% in the PTCA group and 4.9% in the thrombolysis group (ns). At six months, a combined endpoint occurred in 23 patients in the primary PTCA group and in 50 patients in the thrombolysis group (p &lt; 0.00005). Six months' mortality was 4.9% in the PTCA group and 7.3% in the thrombolysis group (ns). Among patients in the PTCA group, left ventricular ejection fraction was significantly higher, stay in hospital was shorter and there were significantly fewer incidences of heart failure and severe arrhythmias than among patients in the thrombolysis group. The results of primary PTCA implemented in our departments are comparable with those reported in randomized trials from experienced centres. Our study indicates that patients treated with primary PTCA have fewer complications, a better left ventricular systolic function and a shorter hospital stay compared with patients treated with thrombolysis.  相似文献   
980.
Intra-articular injection of local anaesthetic is a confirmed method of treatment of postoperative pain, particularly after arthroscopy of the knee. The wrist however, has a limited capacity for intra-articular instillation of local anaesthetic, and the aim of this study was to investigate the effect of intra-articular bupivacaine on postoperative pain after arthroscopy of the wrist. We did a prospective, non-randomised study with two comparable, consecutive series of patients undergoing diagnostic/therapeutic wrist joint arthroscopy 20 of whom were given intra-articular 0.5% bupivacaine 5 ml at the end of the arthroscopic procedure and 20 of whom were not. Postoperative pain and use of analgesics (morphine, non-steroidal anti-inflammatory drugs (NSAID) and paracetamol) were recorded in all patients during the following five postoperative days using a visual analogue scale (VAS) and a pain diary. The bupivacaine group reported less pain and less use of analgesics in the first postoperative hours, but for the remaining five postoperative day's pain and the use of analgesics were similar in the two groups. We conclude that intra-articular injection of 0.5% bupivacaine 5 ml after wrist joint arthroscopy reduces pain and use of analgesics during the first postoperative hours, but has no effect during the following five days.  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