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   801690篇
  免费   50398篇
  国内免费   1304篇
耳鼻咽喉   9912篇
儿科学   26607篇
妇产科学   19099篇
基础医学   121351篇
口腔科学   20500篇
临床医学   69794篇
内科学   154182篇
皮肤病学   16625篇
神经病学   59222篇
特种医学   30186篇
外国民族医学   76篇
外科学   121518篇
综合类   15648篇
现状与发展   2篇
一般理论   160篇
预防医学   60274篇
眼科学   17307篇
药学   58803篇
  3篇
中国医学   2361篇
肿瘤学   49762篇
  2021年   5469篇
  2018年   18917篇
  2017年   15102篇
  2016年   17710篇
  2015年   7942篇
  2014年   10593篇
  2013年   15691篇
  2012年   23619篇
  2011年   31324篇
  2010年   20569篇
  2009年   17826篇
  2008年   30289篇
  2007年   34313篇
  2006年   22175篇
  2005年   22452篇
  2004年   22550篇
  2003年   22866篇
  2002年   21064篇
  2001年   36655篇
  2000年   37462篇
  1999年   30604篇
  1998年   8079篇
  1997年   6934篇
  1996年   7129篇
  1995年   6797篇
  1994年   6292篇
  1993年   5740篇
  1992年   23115篇
  1991年   23088篇
  1990年   22464篇
  1989年   22219篇
  1988年   20157篇
  1987年   19563篇
  1986年   18591篇
  1985年   17427篇
  1984年   12784篇
  1983年   10816篇
  1982年   6017篇
  1979年   11629篇
  1978年   8201篇
  1977年   6852篇
  1976年   6665篇
  1975年   7274篇
  1974年   8530篇
  1973年   8152篇
  1972年   7659篇
  1971年   7131篇
  1970年   6913篇
  1969年   6349篇
  1968年   5810篇
排序方式: 共有10000条查询结果,搜索用时 328 毫秒
991.
Background: Dreaming reported after anesthesia remains a poorly understood phenomenon. Dreaming may be related to light anesthesia and represent near-miss awareness. However, few studies have assessed the relation between dreaming and depth of anesthesia, and their results were inconclusive. Therefore, the authors tested the hypothesis that dreaming during anesthesia is associated with light anesthesia, as evidenced by higher Bispectral Index values during maintenance of anesthesia.

Methods: With approval, 300 consenting healthy patients, aged 18-50 yr, presenting for elective surgery requiring relaxant general anesthesia with a broad range of agents were studied. Patients were interviewed on emergence and 2-4 h postoperatively. The Bispectral Index was recorded from induction until the first interview. Dream content and form were also assessed.

Results: Dreaming was reported by 22% of patients on emergence. There was no difference between dreamers and nondreamers in median Bispectral Index values during maintenance (37 [23-55] vs. 38 [20-59]; P = 0.68) or the time at Bispectral Index values greater than 60 (0 [0-7] vs. 0 [0-31] min; P = 0.38). Dreamers tended to be younger and male, to have high home dream recall, to receive propofol maintenance or regional anesthesia, and to open their eyes sooner after surgery. Most dreams were similar to dreams of sleep and were pleasant, and the content was unrelated to surgery.  相似文献   

992.
Unicompartmental knee arthroplasty (UKA) is considered the treatment of choice in patients with single compartment arthritis of the knee at early stages or with osteonecrosis limited to one compartment. However, results in the literature are still controversial and it is a technically difficult procedure. The main goal of UKA is to restore the articular space of the afflicted compartment, without influencing the limb alignment. Selection of patients and pre-operative planning are crucial. The necessity to improve functional results and to reduce immobilization of the patients has led to the development of minimally invasive surgery. Applied to UKA, this approach reduces blood loss and surgical time, causes fewer symptomatic postoperative complications, and permits earlier recovery compared to the traditional incision. The shorter incision makes careful pre-operative planning essential. We briefly review the indications for UKA, the pre-operative clinical and radiological assessment, and the surgical procedure. Proocedings of the Consensus Conference “TSS in hip and knee replacement” (Rapallo, Italy 22–24 June 2006)  相似文献   
993.
Background: Gabapentin has been reported to inhibit various acute and chronic pain conditions in animals and humans. Although the efficacy of gabapentin depends on the [alpha]2[delta] subunit of voltage-gated calcium channels, its analgesic mechanisms in vivo are still unknown. Here, the authors tested the role of spinal noradrenergic inhibition in gabapentin's analgesia for postoperative pain.

Methods: Gabapentin was administered orally and intracerebroventricularly to rats on the day after paw incision, and withdrawal threshold to paw pressure was measured. The authors also measured cerebrospinal fluid concentration of norepinephrine and postoperative morphine use after surgery in patients who received oral placebo or gabapentin.

Results: Both oral and intracerebroventricular gabapentin attenuated postoperative hypersensitivity in rats in a dose-dependent manner. This effect of gabapentin was blocked by intrathecal administration of the [alpha]2-adrenergic receptor antagonist idazoxan and the G protein-coupled inwardly rectifying potassium channel antagonist tertiapin-Q, but not by atropine. In humans, preoperative gabapentin, 1,200 mg, significantly increased norepinephrine concentration in cerebrospinal fluid and decreased morphine requirements.  相似文献   

994.
As demand for donor pancreases increases, attempts are being made to utilize even marginal grafts for transplantation. Injury during pancreas recovery can predispose to posttransplant complications and graft loss. Early recognition and correction can salvage these grafts. The authors report an instance of poor segmental perfusion of the pancreas graft that was salvaged by pancreas head resection and enteric drainage through a Roux-en-Y pancreatico-jejunostomy.  相似文献   
995.
Surgery passes through a continuous evolution, thanks to the introduction of new technologies and techniques. Tissue-sparing surgery is a concept introduced in the last years to address prosthetic surgery to a more conservative fashion. We discuss the TSS decalogue with a critical eye, pointing out how traditional surgery is evolving in accordance with TSS statements. Proceedings of the Consensus Conference “TSS in hip and knee replacement”, Rapallo, Italy, 22–24 June 2006  相似文献   
996.
997.
AIMS: To study the time and cost involved in the care of newly registered outpatients with Type 2 diabetes mellitus (DM), compared with patients with hypertension and/or hyperlipidaemia (HTL). METHODS: A total of 313 patients with DM and 58 patients with HTL without diabetes were registered on their first visits to 11 diabetes clinics across Japan. The time and cost involved in their care was recorded over the following 5 months. RESULTS: In the first 3 months, there was an extensive time commitment to both groups. The time spent by physicians was 1.5 times longer for DM than for HTL. The total care time spent by all the care providers for DM was twice that for HTL. The cost of DM care was twice that for HTL, with the cost of medicines excluded. However, half of the cost for DM was for laboratory tests. When these were excluded, and the remaining cost divided by the time spent, the amount for DM was half of that for HTL. Over the 5 months, mean glycated haemoglobin (HbA(1c)) in DM patients improved from 8.0% to 6.5%, and 72% of DM patients achieved the glycaemic target of HbA(1c) < or = 6.5%. CONCLUSIONS: DM care in a diabetes clinic requires a great deal more time and resources than HTL to achieve the best outcome. An educational system for self care, presently lacking in the primary care setting in Japan, would improve glycaemic control for DM patients in the community.  相似文献   
998.
For chronic thromboembolic pulmonary hypertension not amenable to pulmonary endarterectomy, effective medical therapy is desired. In an open-label uncontrolled clinical trial, 104 patients (mean +/- sem age 62 +/- 11 yrs) with inoperable chronic thromboembolic pulmonary hypertension were treated with 50 mg sildenafil t.i.d. At baseline, patients had severe pulmonary hypertension (pulmonary vascular resistance 863 +/- 38 dyn.s.cm(-5)) and a 6-min walking distance of 310 +/- 11 m. Eight patients were in World Health Organization functional class II, 76 in class III and 20 in class IV. After 3 months' treatment, there was significant haemodynamic improvement, with reduction of pulmonary vascular resistance to 759 +/- 62 dyn.s.cm(-5). The 6-min walking distance increased significantly to 361 +/- 15 m after 3 months' treatment, and to 366 +/- 18 m after 12 months' treatment. A subset of 67 patients received a single dose of 50 mg sildenafil during initial right heart catheterisation. The acute haemodynamic effect of this was not predictive of long-term outcome. In this large series of patients with inoperable chronic thromboembolic pulmonary hypertension, open-label treatment with sildenafil led to significant long-term functional improvement. The acute effect of sildenafil may not predict the long-term outcome of therapy.  相似文献   
999.
1000.
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