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   742篇
  免费   42篇
  国内免费   9篇
耳鼻咽喉   32篇
儿科学   23篇
妇产科学   12篇
基础医学   63篇
口腔科学   19篇
临床医学   55篇
内科学   130篇
皮肤病学   21篇
神经病学   99篇
特种医学   36篇
外科学   179篇
综合类   7篇
预防医学   20篇
眼科学   13篇
药学   58篇
肿瘤学   26篇
  2023年   8篇
  2022年   9篇
  2021年   27篇
  2020年   19篇
  2019年   17篇
  2018年   13篇
  2017年   15篇
  2016年   32篇
  2015年   43篇
  2014年   39篇
  2013年   43篇
  2012年   67篇
  2011年   69篇
  2010年   31篇
  2009年   28篇
  2008年   33篇
  2007年   47篇
  2006年   36篇
  2005年   57篇
  2004年   38篇
  2003年   35篇
  2002年   23篇
  2001年   10篇
  2000年   8篇
  1999年   10篇
  1998年   5篇
  1997年   2篇
  1996年   2篇
  1995年   5篇
  1994年   2篇
  1993年   3篇
  1992年   3篇
  1991年   2篇
  1990年   1篇
  1989年   2篇
  1988年   4篇
  1987年   3篇
  1986年   1篇
  1983年   1篇
排序方式: 共有793条查询结果,搜索用时 31 毫秒
61.
62.
Since percutaneous nephrolithotomy (PNL) is a surgical intervention, it may show deteriorative effects on renal function in the early postoperative period. In this study, the deteriorative effects of PNL on renal function were investigated in the geriatric population, and it was compared to the non-geriatric population. A total of 711 patients [64 in the geriatric group (female/male ratio: 33/31, mean age: 70.4 ± 4.2 years), 647 in the non-geriatric group (female/male ratio: 267/380, mean age: 40.9 ± 12.7 years)] were included in the study. Demographic data, biochemical parameters, stone diameters, duration of the operation and estimated glomerular filtration rates (eGFR) were recorded both preoperatively and postoperatively. The eGFR ratio (post-/preoperative) was 1.13 ± 1.00 in the geriatric group, 0.98 ± 0.20 in the non-geriatric group (P < 0.001). Although the mean stone diameter was larger in the geriatric group than the non-geriatric group (10.08 ± 6.5 mm, 8.28 ± 5.54 mm, P = 0.037), the mean duration of the operation was shorter in the geriatric group than in the non-geriatric group (55.7 ± 13.6 min, 61.3 ± 20.9 min, P = 0.036). Hematocrit, hemoglobin, urea levels, and grade of hydronephrosis were not different between the groups. Renal function impairment is expected to be common in the geriatric patient population since they already have lower basal renal function. In the present study, the ratio of postoperative to preoperative eGFR was higher in the geriatric group. Hematocrit, hemoglobin, and urea levels and degree of hydronephrosis of these two groups did not show a great difference. The relatively short duration of the operation in the geriatric group and the diversity of perioperative and postoperative care of these two groups may explain the difference.  相似文献   
63.
Transsphenoidal encephaloceles are rare and the transsellar variety is the least common. We present a 1-year-old male patient with transsellar transsphenoidal encephalocele which herniated into the oral cavity through the congenital split palate. The patient was operated on using a combined transcranial and transpalatal approach without mortality or permanent morbidity. Clinical findings, imaging reviews, surgical repair techniques and postoperative morbidity are discussed with the relevant literature. We conclude that repair of a transsphenoidal encephalocele should be coordinated between a team of neurosurgeons and otorhinolaryngologists. Our surgical outcome supports a transcranial approach for the treatment of these difficult lesions, with transpalatal dissection and exposure.  相似文献   
64.
65.
66.

Background  

Nocturnal enuresis is an important problem among young children living in Turkey. The purpose of this study was to determine the possible differences in the prevalence of enuresis between children in boarding school and daytime school and the association of enuresis with sociodemographic factors.  相似文献   
67.
68.
Persistent exposure to inorganic lead (Pb) is known to adversely affect the immune system. In the present study, we assessed the effect of chronic Pb exposure on susceptibility to infection by the facultative intracellular pathogen Salmonella enterica serovar Typhimurium. Mice were exposed to 10 mM Pb-acetate in drinking water for approximately 16 weeks, resulting in a significant level of Pb in the blood (106.2+/-8.9 microg/dl). Pb exposure rendered mice susceptible to Salmonella infection, manifested by increased bacterial burden in target organs and heightened mortality. Flow cytometric analysis of the splenic cellular composition in normal and Pb-exposed mice revealed no gross alteration in the ratios of B and T lymphocytes or myeloid cells. Similarly, the capacity of B and T cells to upregulate the expression of activation antigens in response to mitogenic or inflammatory stimuli was not hindered by Pb exposure. Analysis of the ability of ex vivo-cultured splenocytes to secrete cytokines demonstrated a marked reduction in IFN-gamma and IL-12p40 production associated with Pb exposure. In contrast, secretion of IL-4 by splenocytes of Pb-treated mice was 3- to 3.6-fold higher than in normal mice. The increased capacity to produce IL-4 correlated with a shift in the in vivo anti-Salmonella antibody response from the protective IgG2a isotype to the Th2-induced IgG1 isotype. We conclude that chronic exposure to high levels of Pb results in a state of immunodeficiency which is not due to an overt cytotoxic or immunosuppressive mechanism, but rather is largely caused by a shift in immune responsiveness to Th2-type reactions.  相似文献   
69.
70.
IntroductionThe recent interest in sleep-related breathing disorders has re-opened the old debate as to whether there is a causal relationship between upper respiratory obstruction and abnormalities in dentofacial development.ObjectiveTo establish the impact of dentofacial development on sleep-related breathing disorders in children.MethodThis is a prospective study in which the dentofacial studies of 30 children, diagnosed with a sleep-related breathing disorder using polysomnography, were compared with a control group of 30 healthy children. The ages of both groups were between 3 and 13 years.ResultsThe statistical analysis showed significant differences between the groups in the proportion of children with a narrow palate (83% of the problem group and 57% in the control; P = 0.024) and cross bite (40% and 13%; P = 0.020). On comparing the angles measured, the only statistically-significant difference was the skull base-mandibular plane angle: The problem children group had a mean of 37.59 ± 5.56 and the control group, a mean of 34.41 ± 4.62 (P = 0.023).ConclusionChildren with sleep-related breathing disorders have abnormalities in facial and dental development caused by upper respiratory obstruction. These anomalies, vertical growth of the face, narrow palate and dental occlusion changes should be taken into account when assessing the indication for a adenotonsillectomy.  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