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   1641篇
  免费   80篇
  国内免费   56篇
耳鼻咽喉   8篇
儿科学   72篇
妇产科学   14篇
基础医学   197篇
口腔科学   26篇
临床医学   175篇
内科学   433篇
皮肤病学   56篇
神经病学   106篇
特种医学   318篇
外科学   107篇
综合类   23篇
预防医学   110篇
眼科学   5篇
药学   64篇
中国医学   2篇
肿瘤学   61篇
  2022年   6篇
  2021年   20篇
  2020年   11篇
  2019年   12篇
  2018年   20篇
  2017年   7篇
  2016年   12篇
  2015年   20篇
  2014年   29篇
  2013年   61篇
  2012年   46篇
  2011年   36篇
  2010年   51篇
  2009年   81篇
  2008年   48篇
  2007年   87篇
  2006年   49篇
  2005年   45篇
  2004年   40篇
  2003年   39篇
  2002年   32篇
  2001年   29篇
  2000年   29篇
  1999年   40篇
  1998年   74篇
  1997年   85篇
  1996年   105篇
  1995年   64篇
  1994年   61篇
  1993年   55篇
  1992年   36篇
  1991年   27篇
  1990年   31篇
  1989年   52篇
  1988年   37篇
  1987年   39篇
  1986年   47篇
  1985年   46篇
  1984年   13篇
  1983年   16篇
  1982年   18篇
  1981年   11篇
  1980年   14篇
  1979年   11篇
  1978年   16篇
  1977年   12篇
  1976年   15篇
  1975年   13篇
  1974年   6篇
  1973年   7篇
排序方式: 共有1777条查询结果,搜索用时 15 毫秒
101.
The authors describe their experience with methyl tertiary butyl ether (MTBE) in a larger series of patients than previously reported in order to acquaint physicians with both its effectiveness for dissolution of common bile duct calculi and the limitations of its use. Ten patients with 13 biliary calculi underwent percutaneous stone dissolution treatment with the experimental cholesterol solvent, MTBE. Three stones completely dissolved within 30 minutes, seven were reduced in size, and three were visibly unaffected. All stones not completely dissolved were easily extracted by means of a stone basket except for one in a patient taken to surgery. Although MTBE perfusion is an effective technique for management of biliary calculi, practitioners should be aware that its use is quite time consuming and its odor difficult to control.  相似文献   
102.

Objective

To establish the relation between handball playing, passive hip range of motion (ROM), and the development of radiological hip osteoarthritis (OA) in former elite handball players. Two related issues are addressed: (a) the relation between long term elite handball playing and the incidence of hip OA; (b) the relations between hip ROM, OA, and pain.

Methods

Data on 20 former elite handball players and 39 control subjects were collected. A questionnaire yielded personal details, loading patterns during physical activity, and previous lower limb joint injury. Bilateral radiographs were analysed to diagnose and classify hip OA. Passive hip ROM was measured bilaterally with a goniometer.

Results

A close relation was found between long term elite handball practice and the incidence of hip OA: 60% of the handball players were diagnosed with OA in at least one of the hip joints compared with 13% of the control subjects. Passive ROM measured in the handball players was significantly lower for hip flexion and medial rotation and higher for abduction, extension, and lateral rotation than the control values. The handball players with OA reported less pain in the hip joints during daily activities than the control subjects with OA.

Conclusion

The risk of developing premature hip OA seems high for retired handball players and significantly greater than for the general population. Pain and discomfort represent two difficult diagnostic challenges to the sports physician, as the repetitive nature of movements that are specific to handball can lead to alterations that are rarely seen in the general population.  相似文献   
103.
Differences in magnetic resonance (MR) imaging signal-to-noise (S/N) performance between saddle-shaped and solenoidal coils have been postulated. Each coil shape is tied to a particular magnetic field configuration, so that they are not typically interchangeable except in special situations. The solenoidal coil is predicted to have a two- to three-fold advantage over the saddle-shaped coil. Simple basic arguments raise a dispute with this assertion. Experiments show that both coils produce essentially equivalent S/N levels.  相似文献   
104.
The authors achieved successful percutaneous extraction of urinary calculi via an intercostal approach in 24 patients. In one patient, a large hydrothorax developed and thoracentesis was required; 2 patients had moderate and 6 minimal pleural fluid collections which did not require treatment. No patient had pneumothorax. Intercostal puncture provides direct access to the upper and middle poles of the kidney when they lie above the twelfth rib and subcostal angulation is not feasible. Such an approach is advantageous for stones in the ureter, as well as renal stones which are inaccessible from the lower pole. Fluoroscopy should be performed when planning the puncture in order to avoid the lung, and a working sheath is recommended.  相似文献   
105.
Conces  DJ  Jr; Lappas  JC; Cockerill  EM 《Radiology》1985,155(1):49-50
Forty-five patients undergoing double-contrast barium enema examinations were studied to identify the incidence of transient bacteremia associated with the examination. Blood cultures were obtained immediately prior to the examination and at 5, 10, and 20 minutes after the start of the examination. Blood samples were cultured in both aerobic and anaerobic media, and four of these cultures were positive for organisms that are common skin contaminants. No bacteremia was identified from enteric pathogens. The data herein suggest that patients with cardiac valvular disease are not at greater risk of bacteremia during double-contrast barium enema examinations.  相似文献   
106.
The radiopharmaceutical iodine 131 metaiodobenzylguanidine (I-131 MIBG) has been shown to locate pheochromocytomas scintigraphically with a false-negative rate of approximately 13%. To improve image quality and reduce the false-negative rate, I-123 was examined as a radioactive label for MIBG, as it has many advantages over I-131, including superior dosimetry and better detection efficiency. Diagnostic doses of 0.5 mCi (18.5 MBq) I-131 MIBG and 10.0 mCi (370.0 MBq) I-123 MIBG with nearly equivalent radiation dosimetries were compared in 18 patients with known or suspected pheochromocytomas. Images of superior quality were obtained with I-123 MIBG in 18 of 18 patients, and in eight cases lesions not visualized on I-131 MIBG scintigraphy were portrayed. A further advantage of I-123 MIBG is that it permits single photon emission computed tomography (SPECT). This was performed in six cases and provided additional information in three cases. The adrenal medullae were definitely visualized using I-123 scintigraphy in eight of 14 patients still possessing adrenal glands, whereas I-131 MIBG images portrayed the adrenal medulla in only one of 14 cases. Five remaining patients had multiple abdominal tumor deposits that were difficult to differentiate from normal adrenal medullae.  相似文献   
107.
Fifty-two patients with clinical stage A and B carcinomas of the prostate were imaged by ultrasound (US) transrectally with a 5-MHz linear array transducer and transabdominally with a 3-MHz sector scanner prior to radical prostatectomy. The fresh specimens of 44 prostate glands were scanned in a water bath with a 5-MHz linear array transducer in multiple planes. In all cases, histopathologic correlation was obtained. Prostatic carcinoma presented as an echopenic lesion in 54% of the specimens, as a slightly hypoechoic area in 22%, and could not be identified in 24% because of its isoechoic characteristics. In contrast to many previous reports, no instance of echogenic cancer was observed.  相似文献   
108.
Arteriovenous malformations of the extremities: MR imaging   总被引:3,自引:0,他引:3  
Cohen  JM; Weinreb  JC; Redman  HC 《Radiology》1986,158(2):475-479
Eight patients with angiographically proved arteriovenous malformations (AVMs) of the extremities (seven congenital, one posttraumatic) were evaluated with magnetic resonance (MR) imaging using a 0.35-T superconducting system and spin-echo pulse sequences. Congenital AVMs appeared as accumulations of dilated tortuous blood vessels infiltrating the involved muscles. A posttraumatic acquired AVM of the shoulder consisted of a large feeding artery associated with a pseudoaneurysm and a soft-tissue mass. MR imaging allowed precise anatomic localization and provided details concerning the size and extent of the AVMs. The relationship of AVMs to specific muscle groups, bones, and vascular structures could be accurately determined. Although major feeding and draining vessels were identified, the exact arteries and veins supplying and draining the AVM could not be ascertained. Images obtained in the transverse plane consistently yielded the most useful information. MR imaging and angiography may be complementary techniques in the initial evaluation, follow-up, and treatment planning of AVMs of the extremities.  相似文献   
109.
Thirty-five patients hospitalized for recent angiographically documented arterial occlusion in the legs (27 femoropopliteal arteries and eight grafts) benefited from local fibrinolytic therapy delivered at the site of the occlusion with a 4- or 5-F catheter. This therapy combined a continuous urokinase (UK) infusion of 1,000 U/kg/hour and a lysyl plasminogen (LYS-PLG) infusion of 15 microkatals every 30 minutes. Angiographically confirmed lysis was obtained in 85% of the cases. Only 3% of the patients had major and 6% had minor groin hematomas. Only two patients had concentrations of fibrinogen as low as 100 mg/dl. Intravascular infusion of UK-LYS-PLG is as effective as streptokinase. Its excellent tolerance makes it a good alternative in the treatment of acute ischemia in the lower limbs.  相似文献   
110.
Birnholz  JC 《Radiology》1986,158(3):805-807
Ultrasound (US) can be used to visualize vertebral segments, suggesting a quantitative means of studying vertebral column growth in utero and thus a means of detecting developmental abnormalities. US images of the lumbar spine were obtained in 128 clinically normal fetuses between the gestational age of 11 through 41 weeks. A large-aperture, dynamically focused US system capable of regional magnification was used. Average lumbar spacing was calculated from distance between centrums of at least four lumbar bodies. The average distance between lumbar centrums increased nearly linearly throughout the second and third trimesters (r2 = 0.98). Enhanced anatomic display implies new capabilities for recognizing developmental abnormalities antenatally.  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