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   2843篇
  免费   155篇
  国内免费   17篇
耳鼻咽喉   30篇
儿科学   79篇
妇产科学   134篇
基础医学   292篇
口腔科学   69篇
临床医学   215篇
内科学   488篇
皮肤病学   36篇
神经病学   142篇
特种医学   115篇
外科学   508篇
综合类   129篇
一般理论   2篇
预防医学   212篇
眼科学   108篇
药学   279篇
中国医学   30篇
肿瘤学   147篇
  2023年   29篇
  2022年   71篇
  2021年   102篇
  2020年   55篇
  2019年   102篇
  2018年   125篇
  2017年   66篇
  2016年   77篇
  2015年   93篇
  2014年   118篇
  2013年   127篇
  2012年   233篇
  2011年   255篇
  2010年   147篇
  2009年   103篇
  2008年   168篇
  2007年   178篇
  2006年   145篇
  2005年   127篇
  2004年   110篇
  2003年   115篇
  2002年   81篇
  2001年   43篇
  2000年   36篇
  1999年   31篇
  1998年   20篇
  1997年   10篇
  1996年   15篇
  1995年   7篇
  1994年   13篇
  1993年   9篇
  1992年   27篇
  1991年   19篇
  1990年   12篇
  1989年   19篇
  1988年   9篇
  1987年   15篇
  1986年   7篇
  1985年   5篇
  1984年   10篇
  1983年   9篇
  1982年   13篇
  1981年   4篇
  1980年   6篇
  1978年   4篇
  1977年   4篇
  1976年   7篇
  1974年   5篇
  1973年   5篇
  1971年   4篇
排序方式: 共有3015条查询结果,搜索用时 15 毫秒
41.
This study was conducted to measure selected hematological parameters in goats naturally infected with Anaplasma ovis. In this study 193 blood samples were collected from adult and young goats in north (Gonbad) and northeast (Mashhad) of Iran. Out of the 193 blood samples, 123 samples were positive (infected group) and 70 samples were negative (uninfected group) for A. ovis by polymerase chain reaction. Hematological analysis was carried out on 47 samples from the infected group and 37 samples from the uninfected group. Hematological analysis indicated significant decreases (P?<?0.01) in RBC counts, HCT values, and hemoglobin concentrations in the A. ovis-infected group of goats compared to the uninfected group (P?<?0.01). The mean corpuscular volume, mean corpuscular hemoglobin, WBC counts, lymphocytes, eosinophils, and monocytes in the infected group were lower but neutrophils were higher than in the uninfected group. These differences were not statistically significant (P?>?0.05). The result from this study revealed that A. ovis infection in goats is associated with marked changes in hematological parameters.  相似文献   
42.
43.
44.
45.
46.
47.
The purpose of the present investigation was to assess the reactivity of porcine coronary arteries under in vitro conditions following their exposure to methyl methacrylate (MMA) and hydroxyethyl methacrylate (HEMA) monomers. Confirming previous studies using rat aortas, both MMA and HEMA induced acute/direct relaxation of coronary ring preparations, which was partly dependent on the endothelium. With prolonged tissue exposure, both monomers caused time- and concentration-dependent inhibition of receptor-mediated contraction of the vascular smooth muscle caused by prostaglandin F2∝ (PGF2∝), with HEMA causing more inhibition than MMA. Hydroxyethyl methacrylate, but not MMA, also produced impairment of non-receptor-mediated contraction of the coronary smooth muscle induced by KCl. On the other hand, neither HEMA nor MMA altered relaxation of the smooth muscle produced by the direct-acting pharmacological agent, sodium nitroprusside (SNP). While exposure to HEMA impaired endothelium-dependent vasorelaxation caused by bradykinin (BK), MMA markedly enhanced this endothelial-mediated response of the arteries. The enhanced endothelial response produced by MMA was linked to nitric oxide (NO) release. In conclusion, with prolonged tissue exposure, MMA causes less pronounced effects/adverse consequences on coronary smooth muscle function relative to the effect of HEMA, while enhancing vasorelaxation associated with release of NO from the endothelium. Accordingly, MMA-containing resin materials appear to be safer for human applications than materials containing HEMA.  相似文献   
48.
49.
Management of femoral diaphyseal fractures in the age group of 6-16 years is controversial. There has been a resurgence worldwide for operative fixation in general and TENS (titanium elastic nailing system) in particular.We performed a retrospective review of pediatric femoral fractures treated by TENS. The data was collected from cases operated between July 2007 and June 2010 at Sohar Hospital, Oman.We had treated 16 children (14 boys and 2 girls) with TENS for femoral shaft fractures. The mean age was 12.5 years (range 7-16 years) and mean hospital stay was 7.6 days (range 4-15 days). All fractures were radio-graphically united at a mean of 7.5 weeks (range 5-10 weeks). The nails were removed in 14 children after a mean of 22 weeks (range 6-38 weeks) postoperatively. At follow-up, we had found leg length discrepancy of 1 cm in one child and 10° of internal rotational deformity in another. No angular deformity had occurred.Titanium elastic nailing seems to be a safe and effective method for the treatment of femoral shaft fractures in children between 7 and 16 years of age.  相似文献   
50.
Glucose-6-phosphate dehydrogenase (G6PD) deficiency may cause severe hyperbilirubinemia with bilirubin encephalopathy unless intervention is initiated. The aim of this study was to assess the efficacy of clofibrate in full term G6PD deficient neonates with jaundice. A randomized clinical trial study was performed in two groups of full-term G6PD deficient jaundiced neonates (clofibrate treated group, n = 21; control group, n = 19). Infants in the clofibrate group received a single oral dose of 100 mg/kg clofibrate, whereas control group received nothing. Both groups were treated with phototherapy. Serum total and direct bilirubin levels were measured at the onset of treatments, 16, 24 and 48 hours later. On enrollment, the mean total serum bilirubin (TSB) level in the clofibrate treated group was 18.40 +/- 2.41 and in the control group was 17.49 +/- 1.03 (p = 0.401). At 16, 24 and 48 hours of treatment, the mean TSB in the clofibrate group were 15.2 +/- 1.9, 12.6 +/- 2.4, and 10.1 +/- 2.4 and in the control group were 16.5 +/- 1.2, 13.3 +/- 2.2 and 11.4 +/- 2.4, respectively (p = 0.047). At 48 hours, 7 (33%) cases in the clofibrate group and one (5%) case in the control group were discharged with a TSB < 10 mg/dl (p = 0.031). No side effects were observed on serial examinations during hospitalization, or on the 1st and 7th days after discharge. The results show that clofibrate induces a faster decline in serum total bilirubin level, a shorter duration of phototherapy, and hospitalization with no side effects in full-term G6PD deficient neonates with jaundice.  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