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   972篇
  免费   46篇
耳鼻咽喉   8篇
儿科学   50篇
妇产科学   12篇
基础医学   139篇
口腔科学   14篇
临床医学   143篇
内科学   191篇
皮肤病学   7篇
神经病学   142篇
特种医学   14篇
外科学   72篇
综合类   11篇
一般理论   1篇
预防医学   138篇
眼科学   14篇
药学   33篇
中国医学   1篇
肿瘤学   28篇
  2023年   9篇
  2022年   9篇
  2021年   30篇
  2020年   16篇
  2019年   37篇
  2018年   52篇
  2017年   34篇
  2016年   26篇
  2015年   24篇
  2014年   42篇
  2013年   55篇
  2012年   78篇
  2011年   73篇
  2010年   48篇
  2009年   40篇
  2008年   81篇
  2007年   68篇
  2006年   72篇
  2005年   50篇
  2004年   54篇
  2003年   22篇
  2002年   40篇
  2001年   6篇
  2000年   6篇
  1999年   6篇
  1998年   6篇
  1997年   7篇
  1996年   4篇
  1995年   2篇
  1993年   1篇
  1992年   4篇
  1991年   2篇
  1990年   5篇
  1989年   2篇
  1988年   2篇
  1984年   1篇
  1981年   1篇
  1979年   3篇
排序方式: 共有1018条查询结果,搜索用时 375 毫秒
131.
This study examined the factor structure of the Children's Depression Inventory (CDI) among children and adolescents with chronic pain using exploratory and confirmatory factor analysis in a large, multisite sample of treatment-seeking youth. Participants included 1,043 children and adolescents (ages 8–18) with a range of chronic pain complaints who presented for initial evaluation at 1 of 3 tertiary care pediatric chronic pain clinics across the United States. They completed the CDI and reported on pain intensity and functional disability. Factor analysis was conducted using a 2-step (exploratory and confirmatory) approach. Results supported a 5-factor model for the CDI with good fit to the data. The distribution and item-total correlations of the somatic items (eg, pain complaints, fatigue) were explored in this sample. Results indicate that the CDI is a useful tool for assessing depressive symptoms in youth with chronic pain, but some caution is warranted in interpreting the clinical significance of scores in light of the overlap of specific symptoms common to both pain and depression.PerspectiveThe CDI can be considered a valid tool for assessing mood symptoms in children with chronic pain. Caution is encouraged when interpreting the clinical significance of scores due to symptom overlap between chronic pain and depression.  相似文献   
132.
133.
134.
A comparison of salivary flow rates was made between two groups of healthy, unmedicated, elderly, Caucasian men and women ranging in age from 60 to 90 years. One group was a control group, while the other group had both active and restored root caries. The control group consisted of 69 individuals with a mean age of 73 years. The root caries group consisted of 39 individuals with a mean age of 71 years. The groups were evaluated for unstimulated (UPAR) and stimulated parotid gland flow rates (SPAR), unstimulated (USUB) and stimulated submandibular/sublingual gland flow rates (SSUB), and stimulated whole saliva flow rates (SWhole). Parotid flow rates were determined with the use of a Carlson-Crittenden cup, while submandibular/sublingual flow rates were determined by means of the NlDR collector. A 2% citrate solution was used for stimulation in glandular collections. Subjects chewed a 1-cm3 cube of paraffin to stimulate whole saliva. The results showed that the control group had higher UPAR, SPAR, USUB, SSUB, and SWhole than the root caries group.  相似文献   
135.
Success in using adjunctive surfactant therapy for meconium aspiration has been inconsistent. We tested the hypothesis that the ability of exogenous surfactant to improve gas exchange and pulmonary compliance after meconium aspiration is related to the method of surfactant administration. In anesthetized rabbits (2.4 +/- 0.16 kg body weight), an endotracheal tube (ETT) was placed in the lower trachea, and the lungs were ventilated mechanically. After a control period, filtered meconium (3-5 mL/kg) was instilled through the ETT. Group 1 (n = 5) was not given surfactant. Thirty minutes after meconium instillation, group 2 (n = 5) was given a bolus of bovine surfactant (Beractant, 4 mL/kg) through the ETT, and group 3 (n = 5) was given an infusion of Beractant (4 mL/kg for 1 hr) through the side-port of the ETT. Thirty minutes after meconium instillation, tracheal pressure increased by 8 +/- 1 cm H(2)O (mean +/- SEM), dynamic compliance decreased by 0.36 +/- 0.07 mL/cm H(2)O/kg, arterial PO(2) (PaO(2)) decreased by 49 +/- 6.0 mmHg, arterial PCO(2) (PaCO(2)) increased by 12 +/- 2.4 mmHg, and arterial pH (pHa) decreased by 0.09 +/- 0.02. After 3 hr of exposure to meconium, tracheal pressure was significantly (P < 0.001) lower in group 3 compared to groups 1 or 2. PaO(2) remained below baseline in all groups. Group 3 had a significantly (P = 0.001) higher dynamic compliance than groups 1 or 2. Likewise, static compliance was higher for group 3 compared to groups 1 or 2, with the greatest difference at low lung volume. Mean arterial blood pressure, pulse rate, PaCO(2), and pHa were not significantly different between groups. These results suggest that continuous infusion of exogenous surfactant is more effective than bolus administration in improving pulmonary function after meconium aspiration.  相似文献   
136.
目的:本研究的目的是通过对非妊娠妇女的纵向取样,评价社会心理压力与细菌性阴道病的相关性。研究设计:设计为1年期前瞻性纵向研究,3614例15~44岁非妊娠妇女在常规健康检查时纳入研究。每季度评价一次,共1年。包括:标准盆腔检查、临床症状评价及详细的自我汇报式面谈。结果:社  相似文献   
137.
We report on a set of monozygotic twin boys concordant for Rubinstein-Taybi syndrome, and discuss the possible genetic basis of the disorder. © 1993 Wiley-Liss, Inc.  相似文献   
138.
Elevated levels of trans-4-hydroxy-2-nonenal (HNE) are observed in brain tissues in patients with neurodegenerative diseases. Although astrocytes are known to play a crucial role in regulating and supporting neuronal processes, their capacity to detoxify HNE is unknown. In this work, we examined the extent to which HNE undergoes phase I and phase II metabolism in astrocytes. Murine astrocytes were exposed to three different concentrations of HNE. The loss of HNE was approximately 90%, 80%, and 70% for 1, 5, and 15 microM HNE, respectively, following a 10 min incubation. The expected metabolites trans-4-hydroxy-2-nonenoic acid (HNEAcid), (4-hydroxynonanal-3-yl)glutathione (GSHNE), and (1,4-dihydroxynonane-3-yl)glutathione (GSDHN) accounted for 90% of HNE lost at 1 microM HNE. However, when astrocytes were exposed to 5 and 15 microM HNE, those metabolites accounted only for 50% and 17%, respectively. Binding to macromolecules accounted for only 5-10% of HNE loss. Furthermore, depletion of GSH content had only a small effect on HNE metabolism without elevating HNE oxidation and suggests that other unidentified metabolic pathways are functioning. We identified two novel metabolites of HNE, gamma-nonalactone and the potent pyrrole forming compound, 4-oxo-nonanal (ONA). Occurrence of 1,4-dihydroxynonene was observed as well. These data suggest that the biotransformation of HNE yields products with differing or enhanced toxicity, as well as nontoxic products.  相似文献   
139.
Managed care's influence on health care is enormous. Social workers in medical and mental health settings spend increasing amounts of time dealing with client issues that result from managed care decisions. We first provide a brief overview on the impact of managed care decisions on access to quality and appropriate medical care. Next, we present the U.S. Supreme Court's decision in Aetna Health Inc. vs. Davila (2004) and its impact on consumers' access to appropriate health care. Finally, we discuss the implications of this case for social work practice.  相似文献   
140.
NKT cell activation plays an important role in regulating innate and adaptive immunity during infection. We have previously found that there is a dramatic reduction in the NKT cell population on day 3 after an acute lymphocytic choriomeningitis virus (LCMV) infection. In this study, we report that this loss continued for at least 3 months and was not simply due to internalization of the TCR. Concomitant with the decrease in NKT cells was an increase in the percentage of Annexin V(+) NKT cells that remained in vivo, suggesting that the reduction in NKT cells at these late stages post-infection occurred by activation-induced cell death. Interestingly, APC from LCMV-infected mice could activate NKT cells in vitro at higher levels than those from uninfected mice and was concomitant with an increase in apoptosis in NKT cells. However, this could not be blocked by mAb to murine CD1d, and APC from LCMV-infected (but not uninfected) CD1d1-deficient mice could also stimulate NKT cells. Collectively, our data suggest that the activation and subsequent long-term loss of NKT cells is a normal component of the host's antiviral immune response, and this occurs in a CD1d-independent manner.  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