全文获取类型
收费全文 | 5505篇 |
免费 | 359篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 35篇 |
儿科学 | 230篇 |
妇产科学 | 164篇 |
基础医学 | 866篇 |
口腔科学 | 46篇 |
临床医学 | 425篇 |
内科学 | 1084篇 |
皮肤病学 | 141篇 |
神经病学 | 305篇 |
特种医学 | 173篇 |
外科学 | 729篇 |
综合类 | 194篇 |
一般理论 | 6篇 |
预防医学 | 418篇 |
眼科学 | 156篇 |
药学 | 445篇 |
中国医学 | 53篇 |
肿瘤学 | 409篇 |
出版年
2023年 | 22篇 |
2022年 | 54篇 |
2021年 | 128篇 |
2020年 | 59篇 |
2019年 | 115篇 |
2018年 | 146篇 |
2017年 | 82篇 |
2016年 | 107篇 |
2015年 | 124篇 |
2014年 | 192篇 |
2013年 | 241篇 |
2012年 | 398篇 |
2011年 | 429篇 |
2010年 | 218篇 |
2009年 | 166篇 |
2008年 | 305篇 |
2007年 | 279篇 |
2006年 | 301篇 |
2005年 | 288篇 |
2004年 | 258篇 |
2003年 | 239篇 |
2002年 | 194篇 |
2001年 | 169篇 |
2000年 | 138篇 |
1999年 | 135篇 |
1998年 | 67篇 |
1997年 | 47篇 |
1996年 | 34篇 |
1995年 | 36篇 |
1994年 | 49篇 |
1993年 | 34篇 |
1992年 | 89篇 |
1991年 | 65篇 |
1990年 | 54篇 |
1989年 | 54篇 |
1988年 | 44篇 |
1987年 | 46篇 |
1986年 | 57篇 |
1985年 | 60篇 |
1984年 | 32篇 |
1983年 | 29篇 |
1982年 | 19篇 |
1979年 | 22篇 |
1978年 | 22篇 |
1977年 | 19篇 |
1975年 | 16篇 |
1974年 | 16篇 |
1973年 | 23篇 |
1972年 | 18篇 |
1968年 | 17篇 |
排序方式: 共有5879条查询结果,搜索用时 15 毫秒
1.
2.
The paper presents machine learning (ML) models that predict sedimentation in the harbour basin of the Port of Rotterdam. The important factors affecting the sedimentation process such as waves, wind, tides, surge, river discharge, etc. are studied, the corresponding time series data is analysed, missing values are estimated and the most important variables behind the process are chosen as the inputs. Two ML methods are used: MLP ANN and M5 model tree. The latter is a collection of piece-wise linear regression models, each being an expert for a particular region of the input space. The models are trained on the data collected during 1992-1998 and tested by the data of 1999-2000. The predictive accuracy of the models is found to be adequate for the potential use in the operational decision making. 相似文献
3.
D Adhikari M De P K Paladhi S Chandra D K Bhattacharya 《Journal of the Indian Medical Association》1991,89(7):190-192
Blood bank staff, 8 out of 25 (32%) have been exposed to hepatitis B virus (HBV) and the prevalence of HBV markers in blood bank employees handling high risk subjects show hepatitis B surface antigen (n = 1), hepatitis B surface antibody (n = 7), hepatitis B core antibody (n = 6) and combined hepatitis B surface antibody and hepatitis B core antibody (n = 6) seropositivity but all are negative to human immunodeficiency virus (HIV). Serum alanine aminotransferase was raised in the employees than normal subjects and it is suggestive of sub-clinical hepatitis. The employees of blood bank should be trained for proper handling of test materials and must be periodically monitored for HBV and HIV. Immunisation for HBV is mandatory only for the employees of transfusion centre which handles high risk subjects. 相似文献
4.
The authors report a case of massive Trichuris trichiura infection, resulting in severe anaemia and congestive cardiac failure in a 9-year-old Iban boy, who was resistant to the usual oral anthelmintic treatment, but promptly responded to mebendazole retention enema. This patient also had an associated Entamoeba histolytica infection. 相似文献
5.
6.
Akshay Pratap Devendra Kumar Gupta Chandra Shekhar Agrawal Rakesh Kumar Pandit Shailesh Adhikary Anand Kumar Awadhesh Tiwari Satyendra Narayan Singh 《International journal of urology》2007,14(3):198-202
OBJECTIVES: We analyzed the methods and outcomes of urethroplasty in men with complex urethral disruptions. METHODS: The medical records of 40 men with complex urethral disruptions were analyzed. Surgical methods were individualized according to stricture location, severity and length of the stricture, bladder neck characteristics and presence of complicating factors. Patients were divided into four groups based on the above characteristics. RESULTS: End-to-end urethroplasty performed in six patients with short bulbar strictures (<3 cm) was successful in all. Elaborated perineal repair was performed in 10 patients with intermediate (3-6 cm) strictures with or without complicating factors. Elaborated perineal repair with urethral substitution was performed in nine patients with long segment stricture (>6 cm). Abdominal transpubic repair was successfully applied to patients with rectourethral fistula or lacerated bladder neck. Success rate of anastomotic urethroplasty was 95% while over all success rate was 85%. CONCLUSION: Guidelines for urethral reconstruction of complex urethral disruptions are predicated on stricture length, location, bladder neck characteristics and associated complicating factors. End-to-end urethroplasty with stricture excision is highly reliable for short strictures for which previous operative repair have failed. Elaborated perineal repair is extremely versatile for intermediate and longer strictures with associated complicating factors. Abdominal transpubic urethroplasty is effective for patients with rectourethral fistula or lacerated bladder neck. 相似文献
7.
D K Srinivasa A Sahai S B Rotti M B Soudarssanane M Danabalan R N Sahoo K A Narayan G Ramalingam S Srinivasan S Mahadevan B V Bhat P Nalini 《Journal of epidemiology and community health》1997,51(4):443-448
STUDY OBJECTIVES: To assess the poliomyelitis trend, including study of the epidemiological features, and to correlate this with the immunisation coverage of infants. DESIGN: Three annual lameness surveys in children aged 0-60 months employing cluster sampling methods and a series of five cross sectional surveys of immunisation coverage in children aged 12-23 months of age were undertaken. SETTING: Pondicherry, India, 1988-92. SUBJECTS: More than 10,000 children in the age group of 0-60 months took part in the three annual lameness surveys and samples of 210 children aged 12-23 months were covered each year in immunisation coverage surveys. MEASUREMENTS AND MAIN RESULTS: Altogether 50 of 11,461, 24 of 10,093, and 17 of 11,218 children surveyed during 1989, 1990, and 1991 respectively had become lame as a result of poliomyelitis, giving prevalences of 4.4, 2.4, and 1.5 per 1000 children for the three surveys. The corrected prevalences of poliomyelitis were 5.9, 3.2, and 2.0 per 1000 children during 1989, 1990, and 1991 respectively. The proportion of cases aged up to 36 months fell from 48% in 1989 to 12.5% in 1990 and 6% in 1991. The age at onset was less than 1 year in most. The median age at onset was 10.7 months. About 54% of the affected children had received three doses of oral poliomyelitis vaccine (OPV) before the onset of paralysis. In 1988 immunisation coverage for the third dose of OPV was 91% and in 1992 it was 97.6%. The drop out rate for the first versus the third dose of OPV fell from 6.3 in 1988 to 1.9% in 1992. CONCLUSION: Three successive annual lameness surveys showed that poliomyelitis was declining between 1989 and 1991. Five immunisation coverage surveys conducted from 1988 to 1992 showed high initial coverage followed by an improvement in the form of almost universal coverage for OPV. 相似文献
8.
9.
V Bhattacharya G R Reddy Sunish Goyal Umesh Kumar 《Journal of plastic, reconstructive & aesthetic surgery》2007,60(8):892-897
Defects involving the distal leg and foot are frequently encountered following various aetiological factors. Paucity of local tissue causes surgeons to resort to the retrograde peninsular flap, the cross leg flap or the free flap. With specific knowledge of perforators, the fasciocutaneous flap from the calf area can be transferred to the defect in a single stage based on skeletonised distal perforators. The surgical anatomy, flap planning and procedure have been detailed. Nineteen patients were treated during the period 1995 to 2005. The perforators were identified preoperatively by audio Doppler. The flaps were marked and dissected proximal to the defect skeletonising the distal perforators under loupe magnification and transferred to the defect in a single stage. The donor site was skin grafted. Out of 19 cases, 16 flaps healed uneventfully, one flap necrosed completely and in two cases there was marginal necrosis. The cases were followed up for 2-10 years with an average of 6 years. With detailed knowledge of perforators one can safely reconstruct distal moderate-size defects of the lower limb in a single stage, thus having the benefits of free tissue transfer without resorting to microsurgery. This technique has proved to be an advancement in the reconstructive repertoire allowing flaps of non conventional dimensions to be perfused by skeletonised perforators. 相似文献
10.
A total of 168 strains of Salmonella were isolated in the Command Pathology Laboratory (WC) Delhi Cantt during the year 1990. Out of this, 143 were Salmonella typhi, 17 Salmonella paratyphi A, 7 Salmonella typhimurium and 1 Salmonella manhattan. The commonest phage type and biotype of Salmonella typhi was type E1 and type 1 respectively. The dominant biotype of Salmonella paratyphi A was type I. There was a very high degree of multidrug resistance of most of the strains. But all the strains were sensitive to ciprofloxacin and norfloxacin. 相似文献