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   3172篇
  免费   178篇
  国内免费   14篇
耳鼻咽喉   43篇
儿科学   314篇
妇产科学   32篇
基础医学   293篇
口腔科学   91篇
临床医学   205篇
内科学   770篇
皮肤病学   69篇
神经病学   154篇
特种医学   96篇
外科学   588篇
综合类   101篇
一般理论   1篇
预防医学   120篇
眼科学   83篇
药学   154篇
中国医学   18篇
肿瘤学   232篇
  2023年   18篇
  2022年   46篇
  2021年   109篇
  2020年   55篇
  2019年   67篇
  2018年   87篇
  2017年   80篇
  2016年   74篇
  2015年   96篇
  2014年   128篇
  2013年   209篇
  2012年   204篇
  2011年   183篇
  2010年   108篇
  2009年   134篇
  2008年   214篇
  2007年   127篇
  2006年   129篇
  2005年   133篇
  2004年   117篇
  2003年   98篇
  2002年   77篇
  2001年   83篇
  2000年   84篇
  1999年   63篇
  1998年   33篇
  1997年   25篇
  1996年   17篇
  1995年   10篇
  1994年   15篇
  1993年   22篇
  1992年   41篇
  1991年   49篇
  1990年   38篇
  1989年   51篇
  1988年   41篇
  1987年   23篇
  1986年   39篇
  1985年   29篇
  1984年   22篇
  1983年   13篇
  1981年   17篇
  1979年   21篇
  1978年   9篇
  1976年   12篇
  1975年   12篇
  1973年   12篇
  1971年   9篇
  1970年   10篇
  1969年   18篇
排序方式: 共有3364条查询结果,搜索用时 0 毫秒
161.
We report the first case of polyneuropathy induced by levetiracetam, an anti-epileptic medication. Follow up electrodiagnostic studies showed significant improvement after discontinuation of the medication.  相似文献   
162.
163.
164.
A two compartment, double-blind, randomized, parallel study was performed comparing methandrostenolone with placebo in the treatment of osteoporosis. The duration of the study was 24 mo. Dependent parameters included total body calcium (TBCa), measured by neutron activation analysis; bone mineral content of the radius (BMC), measured by photon absorptiometry; and total body potassium (TBK), measured by total body counting. A significant increase in TBK occurred in the treated group, primarily in the first 6 mo; thereafter the TBK remained fairly constant. No significant changes in bone mass occurred, except the 6 mo TBCa measurement increased by 11 grams for the methandrostenolone group and decreased by 6 grams for the placebo group (p = .05). Other evidence also suggests that anabolic steroids may not produce sustained uncoupling of bone formation and bone resorption in osteoporosis. If methandrostenolone is capable of producing an increment in bone mass in osteoporosis, it was not readily observable with the sensitivity of the techniques employed in this study.  相似文献   
165.
CONCLUSIONS: Despite having very high neuronal firing rates, the VNC does not have unusually high mitochondrial activity in vitro. This study is the first in which functionally active mitochondria from the hindbrain have been isolated and characterized. OBJECTIVE: Neurons in the vestibular nucleus complex (VNC) have exceptionally high spontaneous firing rates. Neuronal mitochondria generate adenosine triphosphate critical for maintaining the membrane potentials required for axon firing. We therefore hypothesized a high rate of mitochondrial activity in the VNC. MATERIAL AND METHODS: To test this hypothesis, we compared mitochondrial activity in the VNC with mitochondrial activity from another area of the hindbrain, the cerebellum. Mitochondrial respiratory activity was assessed by measuring oxidative phosphorylation and mitochondrial respiratory enzyme complex activity. RESULTS: Assay results were not significantly different in the VNC compared to those obtained with the cerebellum or with rat brain mitochondria in previous studies.  相似文献   
166.
A 5-month-old boy presented with superior mediastinal syndrome due to a large, unresectable cervico-mediastinal neuroblastoma. He had an unusual constellation of findings not previously reported in neuroblastoma: Horner syndrome, phrenic nerve palsy, and palsy of the ipsilateral recurrent laryngeal nerve. This constellation of findings in adult malignancies is termed the Rowland-Payne syndrome. The child required prolonged mechanical ventilation but responded to chemotherapy and is now free of tumor and completely recovered.  相似文献   
167.
Deficiencies of micronutrients (zinc, iron, folic acid and iodine) during pregnancy are known causes of Low Birth Weight (LBW). Studies have documented status of one or two micronutrients amongst pregnant women (PW). However, no attempt has been made to concurrently assess the prevalence of multiple micronutrient deficiencies and the factors associated with them amongst PW.Objective: The present study was undertaken to assess the prevalence of multiple micronutrient deficiencies amongst PW in a rural area.Methods: A community based cross sectional survey was conducted in six villages of a rural area of district Faridabad in Haryana state, India during November 2000 and October 2001. All PW aged 18 years or more, with pregnancy duration of more than 28 weeks were enrolled. Data were collected on socio-economic status and other demographic parameters. Serum zinc, copper and magnesium levels were estimated by utilizing the Atomic absorption spectrophotometry (AAS); serum ferritin and folate was estimated by Enzyme Linked Immuno Sorbent Assay (ELISA) method and the Radio-lmmuno Assay (RIA) method, respectively and serum thyroid stimulating hormone (TSH) level was estimated by the Abbot AxSYM System. Serum zinc, copper, magnesium, ferritin, and folate levels less than 70.0 μg/dl, 80.0 μg/dl, 1.80 mg/dl, 15 ng/ml, and 3 ng/ml, respectively were considered as indicative of deficiency for respective micronutrients. The TSH levels of 4.670 and more indicated iodine deficiency status. Dietary intake of micronutrients was assessed utilizing 1-day 24-hour dietary recall methodology. Food consumption pattern was assessed utilizing the food frequency questionnaire methodology.Results: Nearly 73.5, 2.7, 43.6, 73.4, 26.3, and 6.4 percent PW were deficient in zinc, copper, magnesium, iron, folic acid and iodine, respectively. The highest concurrent prevalence of two, three, four and five micronutrient deficiency was of zinc and iron (54.9%); zinc, magnesium and iron (25.6%); zinc, magnesium, iron and folic acid (9.3%) and zinc, magnesium, iron, folic acid and iodine (0.8%), respectively. No pregnant woman was found to have concomitant deficiencies of all the six micronutrients. Dietary intake data revealed an inadequate nutrient intake. Over 19% PW were consuming less than 50% of the recommended calories. Similarly, 99, 86.2, 75.4, 23.6, 3.9 percent of the PW were consuming less than 50% of the recommended folic acid, zinc, iron, copper, and magnesium. The consumption of food groups rich in micronutrients (pulses, vegetables, fruits, nuts and oil seeds, animal foods) was infrequent. Univariate and Multivariate logistic regression analysis revealed that low dietary intake of nutrients, low frequency of consumption of food groups rich in micronutrients and increased reproductive cycles with short interpregnancy intervals were important factors leading to micronutrient deficiencies.Conclusion: There was a high prevalence of micronutrient deficiencies amongst the PW of the area, possibly due to the poor dietary intake of food and low frequency of consumption of food groups rich in micronutrients. The concurrent prevalence of two, three, four and five micronutrient deficiencies were common.  相似文献   
168.
A child with solitary functioning hydronephrotic kidney and hypertensive encephalopathy is described. Removal of the contralateral dysplastic kidney failed to normalize his blood pressure.  相似文献   
169.
The aim of this study was to determine the impact of training of health workers in the management of pediatric morbidity in terms of reduction in infant mortality rate (IMR) a 2-year period in rural Ballabgarh with a present IMR of 37 per 1000 live births. The study was designed as a pre- and post-intervention trial. The intervention was started in November 1999 and the outcome measured for the years 2000 and 2001. A sample size of 4000 was estimated for a power of 80 per cent at 5 per cent significance level. The training of the workers was for 4 days and included didactics, video-films, patient demonstrations, etc. Data on under-fives' deaths and their causes using a verbal autopsy tool was done as a part of the routine data collection system. The workers management of pediatric morbidity was assessed based on the post-training knowledge gain, forms filled by them, and referrals seen at the secondary level. The knowledge of the workers on disease and their management improved after the initial training but reached a plateau at a 50 per cent score. A review of 948 forms showed that the workers' disease classification and management was not satisfactory, especially for pneumonia and sick neonates. It was better for fever, measles, dysentery, and diarrhoea. A review of 11 cases referred by workers confirmed this. There was no impact on IMR. A look at the cause of death revealed that malnutrition, diarrhoea, and pneumonia to be the main causes among post-neonatal deaths and birth-asphyxia and prematurity as the main cause of deaths in the neonates. While implementing Integrated Management of Childhood Illnesses (IMCI) in India through the health workers, increased emphasis needs to be placed on training and supervision. Community level issues, such as healthcare seeking, female neglect, etc., may limit the scope of reduction in IMR due to implementation of IMCI.  相似文献   
170.
An 11-year-old girl with an almond lodging in the tracheobronchial tree is described. She presented with an uncommon symptom of subcutaneous emphysema The x-ray revealed left-sided pneumothorax and pneumomediastinum. Intercostal drain was inserted, but she developed respiratory failure and was ventilated. After initial stabilization for 60 hours, she deteriorated again and her x-ray revealed right-sided collapse. After removal of the foreign body, she was discharged but presented again with stridor necessitating tracheostomy. Tracheal stenosis was found and required end-to-end anastomosis. The authors feel that, while foreign bodies are uncommon in this age group with emphysema as a rarer manifestation, this cause should be kept in mind, even in the absence of forthcoming history. A high index of suspicion for tracheobronchial foreign body is required in atypical presentations of acute pediatric respiratory distress.  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