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   34556篇
  免费   1729篇
  国内免费   189篇
耳鼻咽喉   378篇
儿科学   629篇
妇产科学   314篇
基础医学   4396篇
口腔科学   950篇
临床医学   2450篇
内科学   8657篇
皮肤病学   582篇
神经病学   2620篇
特种医学   1359篇
外科学   5692篇
综合类   208篇
预防医学   1214篇
眼科学   503篇
药学   2881篇
中国医学   86篇
肿瘤学   3555篇
  2023年   168篇
  2022年   342篇
  2021年   620篇
  2020年   298篇
  2019年   447篇
  2018年   580篇
  2017年   497篇
  2016年   562篇
  2015年   626篇
  2014年   813篇
  2013年   1032篇
  2012年   1488篇
  2011年   1623篇
  2010年   932篇
  2009年   818篇
  2008年   1392篇
  2007年   1466篇
  2006年   1484篇
  2005年   1621篇
  2004年   1524篇
  2003年   1503篇
  2002年   1519篇
  2001年   1250篇
  2000年   1387篇
  1999年   1215篇
  1998年   441篇
  1997年   327篇
  1996年   342篇
  1995年   297篇
  1994年   274篇
  1993年   264篇
  1992年   808篇
  1991年   727篇
  1990年   741篇
  1989年   790篇
  1988年   717篇
  1987年   648篇
  1986年   613篇
  1985年   573篇
  1984年   448篇
  1983年   335篇
  1982年   195篇
  1981年   159篇
  1980年   168篇
  1979年   288篇
  1978年   226篇
  1977年   177篇
  1974年   168篇
  1971年   153篇
  1969年   171篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
We present herein the rare case of a young man who was found to have a solitary tumor in the right upper lobe of his lung by a routine chest X-ray. The tumor was removed by thoracoscopic surgery, and pathological examinations confirmed the diagnosis of a primary lymphangioma of the lung. A brief review of the available literature on this extremely rare type of benign tumor follows the case report.  相似文献   
42.
In an open trial, 1841 patients were treated with mainly 1 g of cefminox twice a day in adults or 20-30 mg/kg three or four times a day in children for up to 14 days. The clinical efficacy was assessed in 1560 patients (1256 adults, 304 children) and the efficacy rates were as follows: 82.3% in respiratory tract infections (n:525), 85.7% in biliary tract infections (n:87), 66.4% in urinary tract infections (n:509), 92.1% in gynaecological infections (n:126), 88.1% in peritonitis (n:84), 74.9% in all infections (n:1560). The overall bacterial response rates in single infections were 81.5% (81.5% for Staphylococcus aureus, 98.4% for Escherichia coli, 98.6% for Haemophilia influenzae and 38.8% for Pseudomonas aeruginosa). The safety of cefminox was assessed in 1831 patients. Adverse side-effects were reported in 35 patients (1.9%), the most frequent being rash.  相似文献   
43.
Two cases of skullbase-penetrating injuries caused by umbrella tips are reported. Case 1: 24-year-old male. Admitted with disturbance of consciousness, left hemiparesis, nasal bleeding, and laceration of left lower eyelid because of having been stabbed by an umbrella tip. Pupils and fundi revealed no definite findings. Plain skull X-ray showed turbid ethmoid sinus and fracture of planum sphenoidale. Cranial CT showed right putaminal hematoma with intraventricular hemorrhage and pneumocephalus. Increased ICP necessitated surgery two days after the injury. Dural laceration of planum sphnoidale, laceration of left optic nerve, right rectal gyrus contusion and rebleeding from the right lenticulostriate branch were observed. Dural plasty and removal of hematoma with external decompression were carried out. He had a good postoperative course, but left visual loss and left hemiparesis remained. Case 2: 29-year-old male. Admitted with excoriation of his right nostril because of having been stabbed by an umbrella tip, severe headache, and nasal discharge. Oculomotor palsy was observed as well as CSF rhinorrhea and meningeal irritability. Plain skull X-ray showed niveau in sphenoidal sinus, pneumocephalus, and fracture of sella turcica. His complaint disappeared after conservative therapy. We reviewed the literature and found only 4 similar cases. The skullbase, because of its anatomical character, is likely to be penetrated in orbital and periorbital injury caused by umbrella tips. Cases which include disturbance of consciousness have a poor prognosis. We hope the fact that umbrella tips can easily become life-threatening objects will come to the attention of the general public so that similar cases may be avoided.  相似文献   
44.
45.
46.
Diagnosis and treatment of thoracic outlet syndrome   总被引:2,自引:0,他引:2  
Patients who develop symptoms of thoracic outlet syndrome (TOS) have a predisposing anatomic abnormality. In most patients with TOS, the symptoms are caused by entrapment of the brachial plexus and they do not arise from compression of the subclavian artery, as was previously thought. The tests advocated for diagnosing this common syndrome (i.e., evaluating the positional compression of the artery when the arms are raised, the neck is turned, or the shoulders are braced) cannot accurately diagnose this syndrome. There are two reasons for this. The symptoms of TOS are not related to the compression of the artery in the outlet in 98% of patients, and 75% of normal individuals without symptoms show diminished radial pulse on various provocation tests. We employed four timed provocation tests (minute tests) to diagnose TOS: the timed Morley test, timed Wright test, timed Eden test, and elevated arm stress exercise, all of which are very sensitive. In normal individuals without symptoms, 20% experience transitional symptoms such as slight pain and tiredness, on these tests indicating a subclinical state. TOS is treated by keeping the thoracic outlet wide, this being done either conservatively or surgically. In 1993 and 1994, we conservatively treated 418 of 422 patients with TOS by means of active exercise, a brace, and by block therapy. These measures did not reduce the symptoms in 23 of these patients, so surgical treatment was indicated. In the remaining 4 of the 422 patients, conservative treatment was not indicated and surgery was performed directly. All the patients showed significant clinical improvement of varying degree. Presented at the 69th Annual Meeting of the Japanese Orthopaedic Association, Tokyo, April 12, 1996  相似文献   
47.
Spinal cord compression is an extremely serious complication of hereditary multiple exostoses (HME). A case of HME with compression of the cervical spinal cord is reported. Complete recovery following surgery was achieved. A review of the relevant literature revealed 51 previous cases of HME with cord/cauda equina compression. Most patients were under 30 years of age with more men affected than women. The family history was positive in 60%. The cervical and thoracic areas were predominantly affected, with the symptoms usually developing slowly. Recovery following surgery is to be expected in the majority of cases. In patients with HME and suffering from neurological symptoms, the possibility of spinal cord compression should be considered. Prompt diagnosis and surgical excision provide the best prognosis.  相似文献   
48.
49.
Urinary excretion of glycine.prolile dipeptidile aminopeptidase (GP-DAP), N-acetyl-beta-D-glucosaminidase (NAG), alanine aminopeptidase (AAP) and beta 2-microglobulin (beta 2-M), alpha 1-microglobulin (alpha 1-M) was studied preoperatively in 32 patients with renal cell carcinoma. The excretion indices of GP-DAP, AAP and NAG were significantly higher than those in the healthy control group. The excretion of these enzymes obviously reflected the degree of the tumor progression. However, positive rates were not remarkable (37% for GP-DAP, 37% for AAP and 28% for NAG). The excretion of beta 2-M and alpha 1-M was not increased in renal cell carcinoma patients.  相似文献   
50.
Air-pouch-type inflammation was induced by injecting sodium carboxymethyl cellulose solution containing leukotriene C4 (LTC4, 3.20 x 10(-7) M, 0.2 micrograms/ml) and prostaglandin E2 (PGE2, 5.68 x 10(-6) M, 2.0 micrograms/ml), platelet-activating factor (PAF, 1 x 10(-6) M, 0.52 micrograms/ml), or 12-O-tetradecanoyl phorbol 13-acetate (TPA, 1.62 x 10(-6) M, 1.0 micrograms/ml) into an air pouch made on the dorsum of rats. Vascular permeability and tissue edema formation were significantly increased by injecting the phlogogen solution. The histamine level in the pouch fluid was dramatically increased by injecting TPA but not by LTC4 and PGE2, or PAF. Injection of isoproterenol or procaterol with the phlogogen solution produced dose-dependent suppression of both vascular permeability increase and tissue edema formation. However, the TPA-induced increase in the histamine level was not suppressed in parallel with the decrease of vascular permeability or tissue edema formation. These results indicate that beta-agonists suppress vascular permeability response and local tissue edema formation not by inhibiting mast cell degranulation, but by inhibiting the reactivity of the local vasculature to chemical mediators such as arachidonate metabolites, PAF, and histamine and serotonin released from mast cells.  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