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   2431篇
  免费   245篇
  国内免费   12篇
耳鼻咽喉   14篇
儿科学   99篇
妇产科学   19篇
基础医学   273篇
口腔科学   71篇
临床医学   259篇
内科学   499篇
皮肤病学   87篇
神经病学   215篇
特种医学   50篇
外科学   486篇
综合类   57篇
一般理论   5篇
预防医学   145篇
眼科学   120篇
药学   132篇
中国医学   4篇
肿瘤学   153篇
  2023年   13篇
  2022年   26篇
  2021年   62篇
  2020年   42篇
  2019年   70篇
  2018年   59篇
  2017年   49篇
  2016年   46篇
  2015年   61篇
  2014年   79篇
  2013年   88篇
  2012年   127篇
  2011年   141篇
  2010年   92篇
  2009年   68篇
  2008年   132篇
  2007年   161篇
  2006年   142篇
  2005年   162篇
  2004年   146篇
  2003年   124篇
  2002年   121篇
  2001年   24篇
  2000年   19篇
  1999年   24篇
  1998年   28篇
  1997年   24篇
  1996年   21篇
  1995年   19篇
  1994年   16篇
  1992年   22篇
  1990年   17篇
  1989年   24篇
  1988年   17篇
  1987年   16篇
  1986年   29篇
  1984年   16篇
  1983年   29篇
  1982年   17篇
  1981年   22篇
  1980年   12篇
  1977年   14篇
  1975年   16篇
  1974年   16篇
  1973年   11篇
  1965年   11篇
  1963年   12篇
  1962年   12篇
  1961年   14篇
  1960年   21篇
排序方式: 共有2688条查询结果,搜索用时 15 毫秒
31.
32.
The pulse oximeter was evaluated for use in neonates in the delivery room. One hundred neonates, delivered vaginally or by Caesarean section with general or epidural anaesthesia, were studied. After delivery, pulse oximetry probes were placed simultaneously on the ulnar side of the right hand and on the right Achilles tendon to determine whether there was a difference in arterial oxygenation (SpO2). Measurements of SpO2 were taken at 1, 5, 10 min, and 24 hr after delivery. At one and five minutes, SpO2 recorded from the right hand was higher than that recorded from the lower extremities (71.9% +/- 6.5% vs 63.4% +/- 4.3% and 83.3% +/- 4.2% vs 76% +/- 4.1%, mean +/- SD, respectively). At ten minutes these differences diminished, and had almost completely disappeared after 24 hr. These results can be explained by the presence of R-L shunting at the ductus arteriosus level, producing reduced SaO2 in the lower extremities. Oxygen saturation did not differ between neonates delivered vaginally or by Caesarean section, regardless of the presence or type of anaesthesia. We concluded that neonates remain relatively desaturated in the immediate postpartum period and that the SpO2 obtained from the right hand is a better index of neonatal oxygenation than that obtained from the heel.  相似文献   
33.
PURPOSE: As the number of pediatric cancer survivors increases, so does the number of survivors previously exposed to anthracyclines as part of their cancer therapy. Because screening is costly, some have suggested that health-related quality of life (HRQL) measures might be useful in focusing screening tests on those patients with cases most likely to display positive findings. This study reports on the predictive ability of HRQL measures to detect patients with abnormalities on serial cardiac testing. METHODS: Using 127 patients from the ACE-Inhibitor after Anthracycline (AAA) Trial, this study compared serial measures of the Short Form-36 (SF-36; for ages > 13 years) and Child Health Questionnaire-Child Form 87 (CHQ-CF87; for ages < or = 13 years) to serial cardiac performance tests including echocardiographic shortening fraction, left ventricular end systolic wall stress (LVESWS), LVESWS-index, and maximal cardiac index (MCI; a measure of cardiac output at peak exercise). RESULTS: Generally, there was no clinically or statistically significant correlation between any HRQL measure and any cardiac function measure except between MCI and vitality and physical functioning. For each of these measures, the correlation between MCI was statistically significant (P < .006), but each HRQL subscale could explain no more than 7% of the variation in MCI. HRQL measures were not predictive of any other cardiac function measure. CONCLUSION: HRQL measures should not be used in isolation as a screen for cardiac function abnormalities in patients exposed to anthracylines who already have a mild degree of ventricular dysfunction. Patient history appears to be no substitute for cardiac testing in this cohort.  相似文献   
34.
35.
Purpose : Improvements in information and communication technology and the need for off‐campus delivery have led to the increased use of web‐based learning tools in optometry schools around the world. This study compared student‐reported preferences for traditional lecture‐based learning with their preferences when using a web‐based learning tool. Methods : One hundred and thirteen second and third year students from the School of Optometry and Vision Science at the University of New South Wales were surveyed. All students had worked with WebCT for at least two years. Students were asked to rank a range of learning tools in perceived usefulness and also to state how often they used the particular learning tools. Results : The students rated notes (lecture or WebCT delivered) and clinical laboratory sessions as their most useful learning tools. The use of specific learning tools was more diverse, with students reporting that they often used notes (lecture or WebCT delivered), the WebCT calendar tool and the WebCT discussion tool. This result highlights the valuable contribution of the communication aspect of WebCT to fostering learning communities. The least used learning tools were textbooks, websites mentioned in lectures and library print resources. Interestingly, the purchase of textbooks was high with 77 per cent of students on average reporting they had bought the recommended textbooks. Conclusion : Notes were the preferred learning tool of the optometry students at UNSW, suggesting that passive learning of content was the preferred learning style. It is hoped that the introduction of web‐based learning environments may allow students and staff to reflect on their preferred teaching and learning styles. Web‐based learning tools, such as WebCT, provide a powerful method to facilitate independent deeper learning in students with active learning styles. The current encouragement of student‐based active learning methods should see increased use of independent learning platforms, such as WebCT, in optometry schools.  相似文献   
36.
BACKGROUND AND PURPOSE: The primary objective of this study was to estimate the rate of tumour response to a cyclical hypofractionated palliative radiotherapy regimen (QUAD SHOT) in previously untreated patients with incurable squamous cell carcinoma of the head and neck. Secondary objectives were to prospectively evaluate toxicity, quality of life (QoL) and survival in these patients. PATIENTS AND METHODS: The QUAD SHOT consisted of 14 Gy in four fractions, given twice a day and at least 6h apart, for 2 consecutive days. This regimen was repeated at 4 weekly intervals for a further two courses if there was no tumour progression. The QoL tool used was an abbreviation of the EORTC QLQ-C30. RESULTS: Thirty eligible patients (29 Stage IV, 20 performance status 2-3) had at least one treatment and 16 patients completed all three cycles. Sixteen patients (53%) had an objective response (2CR, 14PR) and a further seven had stable disease. Median overall survival was 5.7 months, median progression free survival was 3.1 months. The treatment was very well tolerated, with improved QoL in 11 of 25 evaluable patients (44%). CONCLUSION: The QUAD SHOT regimen is an effective palliative treatment with minimal toxicity and a good response rate, which impacts positively on patients' QoL.  相似文献   
37.
38.
Context: Edible marijuana products are sold as brownies, cookies, and candies, which may be indistinguishable from counterparts without marijuana and are palatable to children and adults. The consumption of an entire product containing multiple dose-units may result in overdose.

Objective: To characterize edible marijuana exposures reported to US poison centers with subgroup analysis by age.

Methods: We analyzed single substance, human exposure calls coded to marijuana brownies, candies, cookies, beverages, or other foods reported to the National Poison Data System from January 2013 to December 2015. Calls were analyzed by state, age, gender, exposure route, clinical effect, therapies, and level of healthcare facility utilization.

Results: Four-hundred and thirty calls were reported: Colorado (N?=?166, 1.05/100,000 population/year) and Washington (96, 0.46) yielded the highest number of exposures. Three hundred and eighty-one (91%) calls occurred in states with decriminalized medical/recreational marijuana. The number of calls increased every year of the study. The most common age groups were: ≤5 years (N?=?109, 0.15/100,000 population/year) and 13–19 (78, 0.09). The most frequent clinical effects were drowsiness/lethargy (N?=?118, percentage?=?43%), tachycardia (84, 31%), agitated/irritable (37, 14%), and confusion (37, 14%). Children ≤5 years have more drowsiness/lethargy, ataxia, and red eye/conjunctivitis. No deaths were reported. The most common therapies administered were intravenous fluids (85, 20%), dilute/irrigate/wash (48, 11 %), and benzodiazepines (47, 11%). Three patients (ages 4, 10, and 57 years) received intubation. 97 (23%), 217 (50%), and 12 (3%) calls were managed at home, treated/released, admitted to a critical care unit, respectively.

Discussion: Although most clinical effects are minor, ventilatory support may be necessary for children and adults. We speculate the increasing exposures may be related to a combination of delayed absorption kinetics of Δ9-tetrahydrocannablnol, lagging packaging regulations, increased accessibility in decriminalized states, and increased familiarity of poison center specialists with edible product codes.

Conclusions: Edible marijuana exposures are increasing and may lead to severe respiratory depression.  相似文献   
39.
In brief Many active patients, particularly brief gymnasts, ballet dancers, wrestlers, and long-distance runners, do not consume enough iron or zinc. Iron and zinc are important for oxygen activation, electron transport, and injury healing. Subclinical deficiencies may impair athletic performance and prolong healing times. People who compete or exercise regularly should be counseled about the importance of these minerals and how to ensure adequate dietary intake.  相似文献   
40.
Acute suppurative bacterial dacryoadenitis (ASBD) with abscess formation is rarely seen in clinical practice. A retrospective review of medical records in the past 8 years identified two unilateral cases in children, one developed presumably after methicillin-sensitive Staphylococcus aureus (MSSA) conjunctivitis and the other due to community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection. Computerized tomography scans showed globe indentation by the enlarged lacrimal glands with rim-enhancing lesions. After failing to respond to intravenous antibiotics, both abscesses resolved promptly with surgical drainage without any long-term sequelae.  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