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   26783篇
  免费   3981篇
  国内免费   760篇
耳鼻咽喉   151篇
儿科学   506篇
妇产科学   700篇
基础医学   5437篇
口腔科学   673篇
临床医学   3200篇
内科学   2785篇
皮肤病学   310篇
神经病学   1227篇
特种医学   781篇
外科学   1827篇
综合类   3870篇
现状与发展   2篇
一般理论   5篇
预防医学   3339篇
眼科学   375篇
药学   2490篇
  62篇
中国医学   2087篇
肿瘤学   1697篇
  2024年   273篇
  2023年   1009篇
  2022年   1733篇
  2021年   2019篇
  2020年   1803篇
  2019年   1881篇
  2018年   2252篇
  2017年   1296篇
  2016年   1264篇
  2015年   1181篇
  2014年   1974篇
  2013年   2161篇
  2012年   1458篇
  2011年   1442篇
  2010年   975篇
  2009年   883篇
  2008年   871篇
  2007年   709篇
  2006年   669篇
  2005年   717篇
  2004年   489篇
  2003年   377篇
  2002年   341篇
  2001年   289篇
  2000年   451篇
  1999年   395篇
  1998年   385篇
  1997年   262篇
  1996年   243篇
  1995年   159篇
  1994年   220篇
  1993年   197篇
  1992年   278篇
  1991年   84篇
  1990年   176篇
  1989年   49篇
  1988年   134篇
  1987年   94篇
  1986年   65篇
  1985年   60篇
  1984年   56篇
  1983年   26篇
  1982年   47篇
  1981年   11篇
  1980年   12篇
  1979年   7篇
  1977年   5篇
  1976年   13篇
  1974年   12篇
  1971年   4篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
集成技术在医院图书馆的应用   总被引:1,自引:0,他引:1  
本文结合医院图书馆实际,采用系统集成及光驱虚拟技术,构建不同系统协同工作的网络环境,实现了多个系统功能的互通,提高了图书馆现代化管理水平及综合服务能力,解决了图书馆建设中存在的管理水平低、服务手段落后及数据库资源闲置浪费等问题。本技术对资金和技术人员紧缺的中小型医院图书馆实现网络共享光盘数据库具有现实意义。  相似文献   
82.
83.
PURPOSE: We evaluate the role of contemporary urological intervention in patients with nephrolithiasis associated with autosomal dominant polycystic kidney disease. MATERIALS AND METHODS: Intervention for upper tract stones associated with autosomal dominant polycystic kidney disease was performed in 5 women and 2 men 29 to 65 years old (mean age 47). Indications for intervention consisted of flank pain in 6 patients and/or hematuria in 2. A total of 12 procedures (mean 1.7 per patient) were performed, including shock wave lithotripsy in 6 patients, percutaneous nephrolithotomy in 2, retrograde endoscopy or manipulation in 3 and extended pyelonephrolithotomy in 1. RESULTS: All patients were rendered stone-free or had only residual "dust." Hospital stay for 5 patients was 1 night or less and there were no complications. Renal function for each patient was stable or improved as measured by serum creatinine. CONCLUSIONS: Most patients with autosomal dominant polycystic kidney disease who require intervention for nephrolithiasis can be safely and effectively treated with essentially any or all contemporary, minimally invasive techniques. The choice of intervention can be based primarily on size and location of the upper tract stones rather than the associated presence of polycystic kidneys.  相似文献   
84.
Variation in clinical outcome following shock wave lithotripsy   总被引:9,自引:0,他引:9  
PURPOSE: We measure and compare operator specific success rates of extracorporeal shock wave lithotripsy (ESWL) performed by 12 urologists in 1 unit to determine interoperator variation. MATERIALS AND METHODS: From January 1, 1994 to September 1, 1997 a total of 5,769 renal and ureteral stones received 9,607 ESWL treatments by 15 urologists with a Dornier MFL 5000 lithotriptor. The 3-month followup data are available for 4,409 stones. Outcome measures consisted of patient demographics, stone characteristics, technical details of lithotripsy, and stone-free and success rates by treating urologists. RESULTS: Treatment results were analyzed for 12 urologists (surgeons A to L) who treated more than 100 stones each, totaling 4,244 with followup information available. Mean stone-free and success rates were 50.6% and 72.3%, respectively. Surgeon A had significantly higher stone-free and success rates of 56.2% and 76.7%, respectively (p<0.05), with treatment results from 877 stones, which was a significantly higher number than others (p<0.05). Significant differences existed in mean number of shocks delivered among urologists (p = 0.0001), with surgeons A and J delivering the highest mean numbers (2,317 and 2,801, respectively). There was no difference in treatment duration (p = 0.75) but variation existed among urologists in terms of mean maximum treatment voltage (p = 0.0001). Mean fluoroscopy time at 4.1 minutes was higher for surgeon A than others (p<0.05). Mean complication rate following ESWL was 4.9% with no difference among urologists (p = 0.175). Re-treatment was required in 21.7% of cases and surgeon A had the lowest rate (15.9%, p<0.05). CONCLUSIONS: We demonstrated clinically and statistically significant intra-institutional differences in success rates following ESWL. The best results were obtained by the urologist who treated the greatest number of patients, used a high number of shocks and had the longest fluoroscopy time. Accurate targeting is crucial when using a lithotriptor, such as the Dornier MFL 5000, with a narrow focal zone of 6.5 mm. in diameter. Other centers should be encouraged to develop similar programs of outcome analysis in an attempt to improve performance.  相似文献   
85.
PURPOSE: We describe the establishment and preliminary characterization of a cell line designated SCRC-1, which was derived from a primary renal small cell carcinoma. MATERIALS AND METHODS: Continuous cultures of a primary stage IVa renal small cell carcinoma and a xenograft in nude mice derived therefrom were characterized by immunohistology, electron microscopy, immunofluorescence/flow cytometry, cytogenetic analysis, and an in vitro drug resistance assay. RESULTS: SCRC-1 cells were reactive with antibodies to NSE, chromogranin-A, bombesin, Bcl-2, CD44s, CD44v6, CD44v7 to 8, vimentin and S100 protein (predominantly beta-subunit), and were unreactive with antibodies to EMA, CD54, EGFR(R1), URO-5, URO-7, URO-8 and URO-10. A similar immunoprofile was also found in both the primary tumor and the xenograft. Cytogenetic analysis revealed the following common clonal aberrations in all 50 metaphases analyzed: 45, XX, t (X;10;18) (p11;p11;q11), -der(18)t(X;10;18), indicating the clonal nature of this neoplasm. SCRC-1 cells showed low drug resistance to cyclophosphamide, doxorubicin, gemcitabine and fluorouracil, intermediate resistance to carmustine and mitomycin-C, and extreme resistance to cisplatin. CONCLUSION: We have documented the initial characterization of SCRC-1, which may be the first cell line reported to be derived from a primary small cell carcinoma of the kidney. This cell line can be used for further studies uncovering the biology and histogenesis of this rare cancer and delineating differences among small cell carcinomas of the kidney and other histological types.  相似文献   
86.
87.
88.
PURPOSE: We refined recently developed pressure flow cutoff values for female bladder outlet obstruction and applied these values in a consecutive group of women undergoing urodynamic testing for various lower urinary tract symptoms. MATERIALS AND METHODS: A total of 87 women with clinical obstruction determined by history and presenting complaint were enrolled in our prospective evaluation of pressure flow studies. We identified 3 groups of participants according to the suspected cause of obstruction, including prolapse in 33, previous incontinence surgery in 25, and no likely source of obstruction identified from history and physical examination only in 29. An additional 124 patients presenting for evaluation of stress urinary incontinence served as controls. Optimal cutoff values for determining obstruction were developed using receiver operating characteristic curves. To determine the prevalence of bladder outlet obstruction these values were prospectively applied to 106 women undergoing urodynamics for various voiding complaints. RESULTS: In controls the average maximum flow rate was 23 cc per second and average detrusor pressure was 21.9 cm. water, whereas the corresponding values in those with clinical obstruction were 10.7 cc per second and 40.8 cm. water (p <0.001). No differences were noted in the various obstruction groups. Receiver operating characteristics analysis revealed that cutoff values of 11 cc per second or less and 21 cm. water or more optimized the selection of patients with bladder outlet obstruction. Using these values we noted a bladder outlet obstruction prevalence of 20% in a consecutive cohort of women undergoing urodynamic studies at our center. CONCLUSIONS: We propose cutoff pressure flow values for identifying women with bladder outlet obstruction although they should be used only in conjunction with the overall clinical situation. Neither pressure flow data only nor clinical symptoms alone may be sufficient for diagnosing obstruction in women.  相似文献   
89.
90.
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