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   21569篇
  免费   2274篇
  国内免费   47篇
耳鼻咽喉   206篇
儿科学   749篇
妇产科学   564篇
基础医学   3077篇
口腔科学   531篇
临床医学   2999篇
内科学   3709篇
皮肤病学   460篇
神经病学   2003篇
特种医学   573篇
外国民族医学   3篇
外科学   2641篇
综合类   541篇
一般理论   30篇
预防医学   2301篇
眼科学   372篇
药学   1651篇
中国医学   20篇
肿瘤学   1460篇
  2023年   197篇
  2022年   297篇
  2021年   543篇
  2020年   359篇
  2019年   517篇
  2018年   571篇
  2017年   440篇
  2016年   474篇
  2015年   514篇
  2014年   627篇
  2013年   876篇
  2012年   1242篇
  2011年   1299篇
  2010年   708篇
  2009年   616篇
  2008年   983篇
  2007年   1114篇
  2006年   1009篇
  2005年   999篇
  2004年   948篇
  2003年   818篇
  2002年   906篇
  2001年   535篇
  2000年   547篇
  1999年   490篇
  1998年   223篇
  1997年   167篇
  1996年   205篇
  1995年   195篇
  1994年   190篇
  1993年   168篇
  1992年   338篇
  1991年   329篇
  1990年   315篇
  1989年   274篇
  1988年   271篇
  1987年   266篇
  1986年   281篇
  1985年   289篇
  1984年   225篇
  1983年   186篇
  1982年   120篇
  1981年   133篇
  1979年   191篇
  1978年   123篇
  1977年   120篇
  1974年   118篇
  1973年   117篇
  1972年   120篇
  1968年   117篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
To describe the treatment of a subchondral bone cyst in the proximal phalanx with parathyroid hormone peptide‐enriched fibrin hydrogel in a warmblood filly. The cyst was localized with computer‐assisted orthopaedic surgery, then curetted and finally filled with parathyroid hormone fragment peptide 1–34 (PTH1−34) covalently attached to a fibrin hydrogel. The cyst healed quickly without any complications. This result supports the hypothesis that PTH1−34 delivered locally in a fibrin hydrogel may improve the postoperative prognosis of surgical management of subchondral bone cysts in horses. Subchondral bone cysts are fairly common in horses. Especially in older horses, the prognosis is poor, even after surgical curettage. Therefore, different management protocols have been investigated in conjunction with surgical curettage to improve prognosis. Locally delivered PTH1−34 seems to be a new method in the treatment of subchondral bone cysts.  相似文献   
22.
We report our experience with elastic stable intramedullary titanium nailing (ESIN) of femoral shaft fractures in children. From 1998 to 2001, we treated 31 children (20 boys), median age 6 (4-11) years, with ESIN for 29 closed and 2 grade I open femoral shaft fractures. We reviewed 30 children clinically after median 1.5 (1-3) years. Their median hospital stay was 6 (2-20) days. All fractures were radiographically united at a median of 7 (5-9) weeks. The nails were removed in 29 children after a median of 22 (6-38) weeks postoperatively. At follow-up, we found a leg-length discrepancy up to 1 cm in 6 children and 10 degrees of internal rotational deformity in 1 child. No angular deformity had occurred. Elastic stable intramedullary nailing seems to be a safe method for the treatment of femoral shaft fractures in children between 4 and 11 years of age.  相似文献   
23.
OBJECTIVE: The purpose of this study was to examine the effect of optimal seated positioning in individually fitted furniture versus suboptimal seated positioning in standard classroom furniture on typical 6- and 7-year-old children's object manipulation skills as measured by the In-hand Manipulation Test (IMT). METHOD: An experimental research design was used to compare IMT performance of two groups of 20 children. One group was positioned in standard, too-large classroom furniture that did not support an optimal seated position, and one group was positioned optimally in furniture fitted to each child for tabletop activities, which allowed for hip flexion to 90 degrees, and foot placement on the floor, and the table to be at flexed elbow height. RESULTS: Independent groups' t tests indicated that children who were optimally positioned performed significantly better (t = -2.77, df = 38, p < .01) than children who were tested in the too-large standard classroom furniture. The difference between groups was greater on the more difficult object manipulation items (t = -3.29, df = 38, p = .001) than on the easier items (t = -1.38, df = 38, p = .08). Age and gender may have differentially affected the results. CONCLUSION: The study's results suggest that the fit of furniture relative to the child's size may have a significant impact on a young, typical child's object manipulation skills. Complex hand skills, such as those involving in-hand manipulation with stabilization, appear to be more affected by the quality of the child's seated position than are simpler, more well-established skills. Findings suggest that test administrators should strive to test young children in the most optimal seated position possible, particularly when the test involves complex hand skills. Further study is needed to assess the impact of the fit of furniture on hand skills in children with disabilities and on children's performance of other tasks.  相似文献   
24.
25.
The aim of the current study was to investigate the in-vitro and in-vivo performance of a press-coated tablet (PCT) intended for time delayed drug release, consisting of a rapidly disintegrating theophylline core tablet, press-coated with barrier granules containing glyceryl behenate (GB) and low-substituted hydroxypropylcellulose (L-HPC). The PCTs showed pulsatile release with a lag time dependent upon the GB and L-HPC composition of the barrier layer. In-vivo gamma-scintigraphic studies were carried out for PCTs containing GB:L-HPC at 65:35 w/w and 75:25 w/w in the barrier layer in four beagle dogs, in either the fed or fasted state. The in-vivo lag time in both the fed and fasted states did not differ significantly (p>0.05) from the in-vitro lag time. Additionally, no significant difference (p<0.05) between in-vivo fed and fasted disintegration times was observed, demonstrating that in-vivo performance of the PCT was not influenced by the presence or absence of food in the gastrointestinal tract. A distinct lag time was obtained prior to the appearance of drug in plasma and correlated (R2=0.98) with disintegration time observed from scintigraphic images. However, following disintegration, no difference in pharmacokinetic parameters (AUC(0-6 dis), K(el), Cmax) was observed. The current study highlighted the potential use of these formulations for chronopharmaceutical drug delivery.  相似文献   
26.
Eighteen renal transplant recipients and sixteen volunteers were subjected to the physiological manoeuvre of head-out water immersion, in order to compare changes in electrolyte and humoral responses known to occur in healthy individuals with those arising as a result of renal denervation in the transplant recipients. Although the tubular sodium response to water immersion was normal, tubular potassium excretion was markedly different in the transplant patients. Plasma values of atrial natriuretic factor increased in both groups and showed a close temporal relationship to urinary excretion of cyclic GMP. The attenuation in transplant recipients of the well-documented suppression of plasma renin activity during water immersion was probably due to a combination of factors, namely lack of renal innervation and an increase in circulating ANF. The small but significant increase in the excretion of enzymically active urinary kallikrein observed only in the transplant recipients during immersion still requires explanation.  相似文献   
27.
28.
29.
Abstract: We report a patient with cutis marmorata telangiectatica with the hitherto unreported anomaly of a double aortic arch. The presence of two major vascular anomalies in this patient may be secondary to a developmental defect of the mesoderm during embryogenesis.  相似文献   
30.
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