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   1252421篇
  免费   96439篇
  国内免费   5863篇
耳鼻咽喉   18272篇
儿科学   33005篇
妇产科学   35795篇
基础医学   177422篇
口腔科学   37303篇
临床医学   107909篇
内科学   244237篇
皮肤病学   25598篇
神经病学   97674篇
特种医学   49626篇
外国民族医学   259篇
外科学   197553篇
综合类   36861篇
现状与发展   9篇
一般理论   327篇
预防医学   85443篇
眼科学   30305篇
药学   96988篇
  21篇
中国医学   5029篇
肿瘤学   75087篇
  2018年   12875篇
  2017年   9958篇
  2016年   10869篇
  2015年   13089篇
  2014年   18411篇
  2013年   26083篇
  2012年   35570篇
  2011年   36695篇
  2010年   21868篇
  2009年   20472篇
  2008年   33755篇
  2007年   36467篇
  2006年   36208篇
  2005年   34839篇
  2004年   33777篇
  2003年   32619篇
  2002年   31156篇
  2001年   61300篇
  2000年   62422篇
  1999年   52506篇
  1998年   14212篇
  1997年   12639篇
  1996年   12175篇
  1995年   11388篇
  1994年   10691篇
  1992年   41611篇
  1991年   39944篇
  1990年   38894篇
  1989年   37836篇
  1988年   35048篇
  1987年   34288篇
  1986年   32258篇
  1985年   30933篇
  1984年   22956篇
  1983年   19395篇
  1982年   11433篇
  1981年   10307篇
  1979年   22019篇
  1978年   15356篇
  1977年   13042篇
  1976年   11525篇
  1975年   12689篇
  1974年   15580篇
  1973年   14869篇
  1972年   14266篇
  1971年   13379篇
  1970年   12656篇
  1969年   12367篇
  1968年   11068篇
  1967年   10105篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
A highly sensitive method for the quantitative determination of a potential antiarrhythmic drug (OF-7976) in the blood plasma has been developed. The method is based on the electron spray ionization/mass spectrometry (ESI-MS) technique without preliminary chromatographic separation and makes use of nibentan as the internal standard. A linear relationship between drug concentration and the peak intensity of ions of the analyzed substance (m/z = 398) and the internal standard (m/z = 382) is established. The detection limit is 3 ng/(0.5 ml plasma). The method is linear from 3 to 25 ng/(0.5 ml plasma) with a correlation coefficient of 0.98. The coefficient of variation was less than 7 %. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 41, No. 3, pp. 45–48, March, 2007.  相似文献   
992.
Background: The Rhinitis Symptom Utility Index (RSUI), originally developed in the United States, consists of a patient-preference weighting scheme and a 10-item questionnaire measuring the severity and frequency of rhinitis related symptoms over a 14-day period. This study aimed to determine whether the Chinese RSUI could adopt the US-based multi-attribute utility function (MAUF) in scoring rhinitis symptoms. Methods: In a Hong Kong study, 116 Chinese adults with allergic rhinitis completed the RSUI questionnaire and 36-item Short-Form Health Survey (SF-36) after they had been seen by two otorhinolaryngologists for disease-severity ratings. Respondents then completed computer-administered direct preference measures, i.e., visual analogue scale (VAS) and standard gamble (SG) assessments. The VAS and SG data were used to estimate a MAUF for the Chinese-based RSUI. Results: The derived MAUF was somewhat different than the one developed for the US RSUI. Test–retest reliability for the Chinese RSUI was satisfactory (ICC = 0.71, p<0.001). Scores differentiated among cases with mild, moderate, and severe symptoms (p<0.001); and between those who did and did not require medications to control symptoms (p = 0.031). Findings were significantly correlated with SF-36 domain scores (r = 0.19 to 0.37; p=0.041 to <0.001). When the US-based scoring function was applied to the Chinese subjects, the resulting mean RSUI score was significantly lower (p<0.001). Comparisons between directly measured VAS and SG scores between the US and Chinese samples, demonstrated significant differences (all p<0.05), with the US subjects consistently rating rhinitis symptoms as worse than Chinese subjects. Conclusions: The Chinese RSUI has good measurement properties that reflect patient preferences from the Chinese. Results suggest that there are differences in preference rating between US and Chinese subjects and that use of the US-based preference function for the RSUI would bias the measurement of rhinitis symptom outcomes in Chinese subjects.  相似文献   
993.
Quality of life after total mesorectal excision for rectal cancer   总被引:3,自引:0,他引:3  
BACKGROUND: After total mesorectal excision for rectal cancer, many surgeons try to avoid an abdominoperineal resection (APR) by performing a transanally double stapled low colo-rectal anastomosis (LRA), frequently without a pouch. This policy is mainly based on the assumption that the quality of life after such LRA is higher than after APR. It has been suggested that a better functional outcome and therefore a higher quality of life might be achieved by a colo-anal J-pouch anastomosis (CPA). The aim of this study was to assess quality of life among disease-free survivors after APR, LRA and CPA. METHODS: The charts of 301 consecutive patients who had undergone surgery for cancer in the middle or lower third of the rectum were analysed. Two hundred four patients were eligible for inclusion. The quality of life among these patients was assessed using one generic (EQ-5D) and two disease-specific questionnaires (EORTC QLQ-C30 and EORTC QLQ-CR38). RESULTS: The response rate was 82%. The median follow-up was 31 months. Overall, quality of life was good but CPA patients had better quality of life scores than APR and LRA patients. This difference was not only due to the better functional outcome but also to the lower incidence of disturbed micturition and sexual problems in the CPA group. CONCLUSION: The quality of life after colo-anal J-pouch anastomosis is better than after abdominoperineal resection (APR) and low colo-rectal anastomosis (LRA). The quality of life after APR is similar to that after LRA.  相似文献   
994.
995.
996.
Phenytoin-induced gingival overgrowth is a recognized side effect in many cerebral palsy patients using diphenyl hydantoin for the control of seizures. Severe gingival overgrowth in these patients can affect normal masticatory function, lead to poor occlusal development, and compromise esthetics. This report addresses the complex nature of treating phenytoin-induced gingival overgrowth in a mentally retarded 20-year-old female patient. For this patient, full-mouth gingivectomy procedure was performed under general anesthesia in a single session. Post operative follow-up was uneventful. This article discusses major indications, contraindications, and protocols to be followed for periodontal surgical procedures done under general anesthesia.  相似文献   
997.
Prostate thermotherapy consisting of 6 sessions of intrarectal 60 min irradiation of 915 MHz microwave generated by a prostathermer (Blodan, Isreal) was performed once or twice a week on 30 patients with benign prostatic hyperplasia. Excluding 2 cases who refused further therapy at the first session because of rectal discomfort, 28 cases were evaluated for the efficacy of the treatment. Good or fair improvement in subjective symptoms was observed in 24 (85.7%) of the cases. Nocturia was significantly relieved from 2.9 to 2.0 a night. Among the objective responses, no improvement was achieved as to residual urine or prostate size, while a significant increase of maximum or average flow rate on uroflowmetry was observed. Adverse effects were minor or moderate, including 2 cases of urethral bleeding and rectal discomfort, 2 cases of lower urinary tract infection and 1 case of hypotension, which occurred at the 5th session. The scoring criteria taking into account of both subjective and objective responses showed that the efficacy is good in 10 cases (33.3%) and fair or good in 20 cases (66.7%). These results indicated the usefulness of the prostathermer as one of non-surgical therapies for benign prostatic hyperplasia.  相似文献   
998.
As a prospective study on asymptomatic microhematuria, complete urological examinations including cystoscopy, IVP, ultrasound and urinary cytology were performed on 422 patients over 40 years old between January 1987 and December 1988 (group A). The results of group A was compared with that of retrospective study on 266 patients, who had incomplete urological examination between January 1984 and December 1985 (group B). Cystoscopy was performed on 321 patients (87.2%) in group A and on 108 patients (40.6%) in group B. Bladder tumor was found in 10 cases (2.4%) in group A, including 7 cases of male patients (5.7%), but in only 1 case (0.4%) in group B. Since the negative rate of abnormal urinary cytology was 50% and that of abnormal IVP was 90% in 10 cases of bladder tumor in group A, cystoscopy was considered to be an essential examination for the screening of patients with asymptomatic microhematuria over 40 years old patients.  相似文献   
999.
The effects of procainamide administration were assessed in a 5-yr-old boy with Schwartz-Jampel syndrome (chondrodystrophic myotonia). Without procainamide the resting metabolic rate was found to be significantly higher than in an age-matched control group. With a serum level of 3.8 mg l-1 procainamide a reduction of the resting metabolic rate of 22% was observed, and times needed to climb stairs and to re-open eyes after forceful contraction (blepharospasm) were significantly reduced.  相似文献   
1000.
BACKGROUND AND PURPOSE: This study investigated the characteristics of intussusception in Taiwanese children of different age groups, including the incidence, length of hospitalization and hospital costs. METHODS: Children with a diagnosis of intussusception who were hospitalized from 1999 through 2001 were identified from a nationwide health insurance claims database. The incidence of intussusception was calculated by age, gender, and season. Length of hospitalization and hospital costs were also analyzed. RESULTS: A total of 6988 cases of intussusception were identified in Taiwan from 1999 to 2001. Among them, 4859 cases occurred in children below 15 years of age. The average incidence among children below age 15 years was 34.5 per 100,000, with a peak incidence of 118.8 per 100,000 observed among children younger than 24 months old. The highest incidence of intussusception in Taiwanese children occurred between 12 and 24 months of age. According to the data for patients below 15 years of age hospitalized for intussusception in year 2000, males were more likely to be affected than females (61.3% vs 38.7%). Intussusception-related hospitalizations were rare in infants in the first few months of life, increased in those 6 to 12 months old, and peaked among children 1 to 3 years old. Among the 952 patients with intussusception admitted to hospitals in 2000, 297 (31.2%) received surgery, incurring higher median medical costs (New Taiwan Dollars [NT dollars] 42,265 or US dollars 1234) and longer median hospital stay (6.2 days) than the 655 patients who did not require surgery (NT dollars 6290 or US dollars 185 for hospitalization of 2.4 days). CONCLUSIONS: The study found that the incidence of intussusception peaked in the second year of life in Taiwanese children. There was also a male predominance and lack of seasonal variation in incidence.  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