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   1338篇
  免费   83篇
  国内免费   6篇
耳鼻咽喉   11篇
儿科学   31篇
妇产科学   32篇
基础医学   158篇
口腔科学   89篇
临床医学   154篇
内科学   344篇
皮肤病学   19篇
神经病学   73篇
特种医学   84篇
外科学   123篇
综合类   7篇
预防医学   41篇
眼科学   101篇
药学   100篇
中国医学   6篇
肿瘤学   54篇
  2024年   1篇
  2023年   19篇
  2022年   54篇
  2021年   59篇
  2020年   41篇
  2019年   48篇
  2018年   59篇
  2017年   41篇
  2016年   53篇
  2015年   67篇
  2014年   85篇
  2013年   79篇
  2012年   94篇
  2011年   109篇
  2010年   46篇
  2009年   51篇
  2008年   97篇
  2007年   85篇
  2006年   74篇
  2005年   63篇
  2004年   49篇
  2003年   28篇
  2002年   26篇
  2001年   21篇
  2000年   21篇
  1999年   25篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1995年   3篇
  1993年   3篇
  1992年   3篇
  1991年   7篇
  1989年   5篇
  1988年   1篇
  1987年   3篇
  1983年   1篇
  1971年   1篇
  1970年   1篇
  1969年   1篇
排序方式: 共有1427条查询结果,搜索用时 0 毫秒
71.
Latinos are the largest minority population in the United States. Although usually classified as a single ethnic group by researchers, Latinos are heterogeneous from cultural, socioeconomic, and genetic perspectives. From a cultural and social perspective, Latinos represent a wide variety of national origins and ethnic and cultural groups, with a full spectrum of social class. From a genetic perspective, Latinos are descended from indigenous American, European, and African populations. We review the historical events that led to the formation of contemporary Latino populations and use results from recent genetic and clinical studies to illustrate the unique opportunity Latino groups offer for studying the interaction between racial, genetic, and environmental contributions to disease occurrence and drug response.  相似文献   
72.
The aim of this study was to determine the effect of a mechanical bowel preparation on postoperative surgical wound infections in patients treated with identical antimicrobial prophylaxis undergoing wide excision and primary closure for chronic pilonidal sinus disease. Patients more than 18 years old were included in the study. All patients had intravenous antimicrobial prophylaxis at the time of anesthesia induction. In a prospective, randomized setting, patients were allocated to either the bowel preparation group or the no-bowel-preparation group. Mechanical bowel preparation was performed using an oral sodium phosphate solution. On the morning of the procedure a rectal enema was performed with the phosphate solution. The primary outcome measure was the rate of wound infection, but all postoperative complications and recurrences were recorded. All patients were actively observed for 1 year after discharge. The overall infection rate for the entire study population was 12.8% (13/101) including 14.3% (7/49) of those who had had the bowel preparation and 11.5% (6/52) of those with no bowel preparation. There was no statistically significant difference between groups (P = 0.680). The mean rate of recurrence for all 101 patients was 4.9% (5/101) at 19.2 months (range 12–32 months) of follow-up. The recurrence rate was 6.1% (3/49) in the bowel preparation group and 3.8% (2/52) in the no-bowel-preparation group (P = 1.000). Although the number of patients is small in this study, our results showed that the mechanical bowel preparation does not cause a decrease in the rate of surgical wound infections after excision and primary closure in patients with chronic pilonidal sinus disease.  相似文献   
73.
74.
75.
BACKGROUND: Autonomously functioning toxic adenomas are a common cause of hyperthyroidism. Although 131I seems to be a good therapeutic option with little postablative hypothyroidism for these patients, only a small number of recent studies have objectively evaluated changes in nodule size by ultrasonography following radioiodine therapy. METHODS: We prospectively followed 39 patients with a mean age of 51.2 (35-75) years for 12 months and the patients who remained toxic thereafter, until euthyroidism was provided. Thyroid function tests, sonographic volumes were determined initially and 3, 6 and 12 months after treatment. Radioiodine doses of 3.7 MBq.g(-1) thyroid tissue corrected to a 100% 24 h 131I uptake were given. Thirty patients received a single dose, two required two doses and three required three to five doses of 131I due to persistent thyrotoxicosis. Sonographic volumes of the diffuse parts of the glands decreased significantly by 18% from a mean+/-SD value of 50+/-27.6 ml to 41+/-27.4 ml by the end of the 12 months. A significant decrease (8.3%, P=0.002) was achieved in the first three months. Toxic adenomas decreased in size more efficiently (54%) from a mean of 26+/-24 ml to 12+/-10 ml during 12 months, but also most significantly (28.8%, P=0.003) in the first 3 months of the follow-up. Thirty of the patients (76.9%) became euthyroid at the end of 12 months of follow-up. Four patients (10.3%) became overtly hypothyroid during the follow-up. CONCLUSION: Single or multiple doses of radioiodine can successfully treat toxic adenomas with a low rate of hypothyroidism and considerable nodule-volume reduction.  相似文献   
76.
An attempt has been made to study the ability of patients with amyotrophic lateral sclerosis (ALS) to 'plan' a task. Electroencephalogram (EEG) data corresponding to 'planning of a movement task' is analyzed in comparison with a normal relaxed state. The study was conducted on 12 patients with ALS (6 males, 3 females, mean age 46.75 years) and on same number of controls (10 males, 2 females, mean age 48.75 years) to evaluate a difference in the ability to 'plan' a movement task between them. Patients with ALS were divided in two groups defined by unclear/clear speech. It has been observed that patients with ALS having unclear speech (Group I) showed considerable reduction (p<0.0001) in 'planning' a movement task, whereas patients with ALS having clear speech (Group II) showed no deficit in 'planning' a movement task (p=0.0577), both in comparison with age-matched controls. Apart from supporting the earlier reports of a possible extended neuronal degeneration across wide area of the frontal lobes, the findings reveal a possible reduction in planning, an executive function of the prefrontal cortex of brain, and also reveal that speech impairment may be associated with cognitive deficits in patients with ALS.  相似文献   
77.
In Streptococcus pneumoniae, the two-component signaling system MicAB was previously shown to contribute to repression of competence when oxygen is limited. In virulent strains expressing the serotype 2 and 6 capsule, mutation of the MicB kinase reduced the lag period of growth when cultures were switched from an aerobic to anaerobic atmosphere. After intranasal challenge of mice, the micB::km mutation decreased virulence, as shown by the absence of symptoms and by a lower level of recovery of CFU from lungs and blood. It is proposed that MicAB is involved in the adaptive response of the bacteria to changes in oxygen level during the course of infection.  相似文献   
78.
A 37-year-old, experienced female diver developed gastric rupture due to rapid ascent from a depth of 37 meters. The incident was preceded by a heavy meal, intake of soda beverages, swallowing of air and water under water, and panic. Sharp abdominal pain was present immediately after surfacing and afterwards. Full abdominal distension developed within two hours after the ascent. No other diving-related pathology was found. Surgery was performed around three hours after the accident and revealed pneumoperitoneum, gastric rupture, gastric content in the abdomen cavity, and signs of acute peritonitis. On surgery, a 4-cm rupture of the lesser curvature was found and sutured. The patient was discharged eight days after the event.  相似文献   
79.
80.
Purpose: To investigate the useof silicone oil in thepatients who had undergone vitrectomy for the treatment of endophthalmitis associated with retinal detachment.Methods: Six consecutive cases of endophthalmitis associated with retinal detachment were included in the study. The mean age of the 4 males and 2 females was 47.25 ± 23.76 years. Endophthalmitis associated with retinal detachment occurred following perforating injuries in 4 eyes, pneumatic retinopexy in 1 eye and cataract surgery complicated with vitreous loss in 1 eye. Preoperative visual acuity was light perception-only in all eyes. Red reflex was absent in all eyes. All the patients underwent vitreous tapping,encirclement, vitrectomy ,liquid-gasexchange, endolaser photocoagulation and silicone oil injection. Results: Mean follow-up time was 14.3 ± 7.20 months. The microorganisms that were isolated from the vitreous aspiration were Staphylococcus epidermidis in 3 cases, Staphylococcus aureus in 1 case. Remaining cases were culture negative. Retinal breaks could be found in 4 eyes. Inflammation subsided significantly at 5 days in all cases. Final retinal reattachment and treatment of endophthalmitis was achieved in 5 eyes at the end of follow-up . Final visual acuity was 20/40 in 1 case, counting finger in 4 cases and no light perception in 1 case. The postoperative complications were optic atrophy in 1 eye, epiretinal membrane in 2 eyes and phitisis bulbi in 1 eye.Conclusion: Silicone oil, a retinal tamponading agent that has antimicrobial activity, may have benefical effect in the surgical treatment of endophthalmitis associated with retinal detachment.  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