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   175233篇
  免费   7612篇
  国内免费   646篇
耳鼻咽喉   2797篇
儿科学   4968篇
妇产科学   3993篇
基础医学   23463篇
口腔科学   6437篇
临床医学   11298篇
内科学   43203篇
皮肤病学   5490篇
神经病学   14200篇
特种医学   3921篇
外国民族医学   2篇
外科学   21624篇
综合类   1065篇
一般理论   49篇
预防医学   16636篇
眼科学   3818篇
药学   12080篇
中国医学   952篇
肿瘤学   7495篇
  2023年   1136篇
  2022年   2104篇
  2021年   4955篇
  2020年   2484篇
  2019年   4567篇
  2018年   6340篇
  2017年   3791篇
  2016年   3655篇
  2015年   4173篇
  2014年   5748篇
  2013年   7920篇
  2012年   12464篇
  2011年   13378篇
  2010年   7060篇
  2009年   5699篇
  2008年   10306篇
  2007年   10863篇
  2006年   10033篇
  2005年   9903篇
  2004年   8884篇
  2003年   8168篇
  2002年   7635篇
  2001年   4497篇
  2000年   5061篇
  1999年   4009篇
  1998年   1007篇
  1997年   819篇
  1996年   649篇
  1995年   562篇
  1994年   463篇
  1993年   398篇
  1992年   1549篇
  1991年   1296篇
  1990年   1178篇
  1989年   953篇
  1988年   822篇
  1987年   756篇
  1986年   775篇
  1985年   668篇
  1984年   492篇
  1983年   410篇
  1979年   454篇
  1975年   318篇
  1974年   397篇
  1973年   396篇
  1972年   337篇
  1971年   377篇
  1970年   338篇
  1969年   352篇
  1968年   309篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
PURPOSE: This multicenter, open-label, phase I/IIa study was undertaken to establish the safety/toxicity profile of cetuximab in combination with gemcitabine and carboplatin in patients with chemotherapy-na?ve, epidermal growth factor receptor-positive, stage IV non-small-cell lung cancer. Secondary objectives were to gather preliminary evidence of efficacy including tumor response rate, time to progression, and overall survival. PATIENTS AND METHODS: Thirty-five patients received a total of 264 3-week cycles of treatment with cetuximab, carboplatin, and gemcitabine. An initial dose of cetuximab 400 mg/m2 intravenously was administered the first week, followed by weekly doses of 250 mg/m2. Carboplatin (area under the curve = 5, day 1) and gemcitabine 1,000 mg/m2 on days 1 and 8 were administered every 3 weeks. Patients were evaluated for tumor response after every two cycles of therapy. RESULTS: The most frequently reported adverse events related to cetuximab included an acne-like rash (88.6%), dry skin (34.3%), asthenia and skin disorders (31.4%), mucositis/stomatitis (25.7%), fever/chills (20%), and nausea/vomiting (17.1%). The majority of these toxicities were mild to moderate. One patient withdrew from the study because of a grade 3 allergic reaction. Myelosuppression was the most frequently observed toxicity related to chemotherapy. Responses among 35 assessable patients included 10 partial responses (28.6%). Twenty-one patients had stable disease. The median time to progression was 165 days, and the median overall survival was 310 days. CONCLUSION: The combination of cetuximab, carboplatin, and gemcitabine was well tolerated with an acceptable toxicity profile. Most grade 3 adverse events were attributable to chemotherapy. The response rate and median survival are encouraging and warrant additional investigation.  相似文献   
992.
993.
There is evidence that B vitamins produce antinociception in animals. However, potentiation of NSAID‐induced antinociception by B vitamins is unclear. The current study was designed to investigate the antinociceptive interaction between a mixture of B vitamins and either acetaminophen or metamizol. Acetaminophen (56–316 mg/kg), metamizol (32–178 mg/kg), and the mixture of B vitamins (32–178 mg/kg of thiamine, pyridoxine, and cyanocobalamin in a 100:100:1 proportion, respectively) or a combination of each drug with the B vitamins mixture was administered orally to female Wistar rats, and the antinociceptive effect determined in the formalin test. Isobolographic analyses were used to define the nature of the interaction between NSAIDs and B vitamins. Oral administration of either drug produced a dose‐related antinociceptive effect. Isobolographic analyses revealed that both acetaminophen or metamizol and the B vitamins mixture interacted synergistically in the formalin test, suggesting that these two combinations could be useful in treating inflammatory pain states. Drug Dev. Res. 66:286–294, 2006. © 2006 Wiley‐Liss, Inc.  相似文献   
994.
OBJECTIVES: To assess treatment options for calculi in horseshoe kidneys and the impact of extracorporeal shockwave lithotripsy (ESWL) on the management of renal stones. MATERIAL AND METHODS: From June 1971 to January 1998, 52 patients with horseshoe kidneys and calculi received treatment at our Urologic Stone Unit. There were 40 men (77%) and 12 women (23%). Average patient age was 41 years (range: 10-70 years). Clinical onset, treatment received and outcome were evaluated retrospectively. A successful outcome was defined as a patient without residual calculi or with fragments <0.4 cm in size. RESULTS: Clinical onset was mainly low back pain in 37 patients (71%). Eighty-nine stones were treated, i.e. an average of 1.7 treatments per patient. Before the ESWL era (May 1987), we performed two heminephrectomies, 16 pyelolithotomies, 12 pyelolithotomies combined with ureteropyeloplasty and one percutaneous nephrolithotomy. Since the advent of ESWL, seven pyelolithotomies and three pyelolithotomies combined with ureteropyloplasty have been done. ESWL was used to treat 48 calculi. In three cases the patient was placed in the prone position due to difficulties in stone focusing. In 37 cases (77%) patients were either rendered stone-free or had residual fragments <0.4 cm in size. Urinary diversion for obstruction was carried out in two cases (4%). CONCLUSIONS: At present ESWL is the first-choice treatment for calculi in horseshoe kidneys. It involves no significant focusing difficulties and is associated with a low incidence of obstructive complications. Open surgery is indicated in cases of stone-related pyeloureteral stenosis and in the presence of calculi >2-2.5 cm in size.  相似文献   
995.
An 81-year-old woman with right lower limb ischemia was scheduled for revascularization of a femoropopliteal bypass grafted 10 years earlier. A popliteal blockade, attempted as part of regional anesthesia with the aid of a nerve stimulator, was not achieved because the posterior tibial nerve could not be located. After surgery, the patient mentioned symptoms in the region of the right knee consistent with complex regional pain syndrome (Ducke's stage 3); the symptoms appeared after the first operation and would explain the absence of response to the nerve stimulator. Using a nerve stimulator to facilitate location of the various nerve trunks for anesthesia involves obtaining a motor response to electrical stimulation. The procedure is becoming more and more frequent because of its many advantages over other more traditional methods. However, it may be impossible to locate a nerve for a variety of reasons.  相似文献   
996.
Heart arrest in cemented hip arthroplasty   总被引:12,自引:0,他引:12  
Hip arthroplasty is a common surgical intervention in our hospital practice, involving high perioperative risk related to patients age and multiple concomitant diseases. Hemodynamic complications described vary from slight hypotension during surgery to heart failure and sudden death, particularly if the operation involves a cemented femoral component. Because of the type of patients undergoing such operations (elderly patients, with osteoporosis and scarce cardiopulmonary reserve), the unclear origin of complications and the lack of consensus on what constitutes adequate monitoring during surgery, hip arthroplasty is problematic for the specialists involved. We report on five deaths during cemented hip arthroplasty; after reviewing the case history and autopsy report of one, we believe the events leading to death were triggered by massive pulmonary embolism.  相似文献   
997.
998.
Arterial catheterization is a simple technique that yields great benefits, such as continuous monitoring of arterial pressure and the possibility of taking repeated samples for analysis. However, it is not free of complications, the main ones being limb ischemia and gas embolism. To reduce the risk of complications, guidelines for insertion and maintenance of arterial catheters have been established. We report two cases of acute hand ischemia secondary to arterial catheterization. Both patients were undergoing surgery for sarcoma-type abdominal cancer and developed acute ischemia of the hand lasting several hours. The predisposing factor in both cases was the existence of a highly advanced sarcoma-type abdominal tumor, probably related to a state of hypercoagulability.  相似文献   
999.
Management of the cervical spine in orotracheal intubation for general anesthesia is an important aspect of daily practice in anesthesiology. Also important are the requirements, techniques and consequences of patient position during surgery. We report a case of tetraplegia during the early postoperative period after stapedectomy for otosclerosis. After surgery, the spontaneously breathing patient was transferred to the recovery room, where a clinical picture of anesthesia and paralysis of all four limbs was evident. We ordered an emergency magnetic resonance image of the cervical spine, which revealed a massive acutely herniated disk at C6-C7 with signs of ischemia or necrosis of the medulla at the same level. After eight months, the patient was still paraplegic and lacked sensation in the lower limbs. Sensation and motor function in the upper limbs was nearly normal. We review the etiopathogenetic mechanisms that might be responsible for this clinical profile.  相似文献   
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