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   2697篇
  免费   146篇
  国内免费   12篇
耳鼻咽喉   29篇
儿科学   214篇
妇产科学   146篇
基础医学   245篇
口腔科学   85篇
临床医学   223篇
内科学   602篇
皮肤病学   121篇
神经病学   201篇
特种医学   121篇
外科学   335篇
综合类   43篇
预防医学   93篇
眼科学   137篇
药学   149篇
中国医学   7篇
肿瘤学   104篇
  2024年   2篇
  2023年   27篇
  2022年   32篇
  2021年   75篇
  2020年   63篇
  2019年   80篇
  2018年   95篇
  2017年   82篇
  2016年   110篇
  2015年   109篇
  2014年   138篇
  2013年   178篇
  2012年   197篇
  2011年   204篇
  2010年   114篇
  2009年   130篇
  2008年   183篇
  2007年   222篇
  2006年   179篇
  2005年   185篇
  2004年   141篇
  2003年   122篇
  2002年   73篇
  2001年   11篇
  2000年   12篇
  1999年   23篇
  1998年   7篇
  1997年   5篇
  1996年   4篇
  1995年   6篇
  1994年   8篇
  1993年   8篇
  1992年   7篇
  1991年   4篇
  1990年   4篇
  1989年   6篇
  1988年   4篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1976年   2篇
排序方式: 共有2855条查询结果,搜索用时 78 毫秒
91.
Objective: Late-preterm delivery is known to be associated with potential adverse effects on lung development. Passive smoking may result in alterations of pulmonary function in infants born late-preterm. Impulse oscillometry (IOS) is a noninvasive, rapid, and practicable technique that can assess lung function. This study aimed to evaluate the effect of passive smoking on lung function tests in preschool children born late-preterm using IOS.

Methods: The study population consisted of a total of 139 children between 3 and 7 years of age born late-preterm who were being followed-up at our outpatient unit at the time of study period. Late-preterms were subcategorized according to presence or absence of exposure to passive smoking (PS). Those with and without exposure to passive smoking were referred to as PS group (56.1%, n?=?78) and non-PS group (43.9%, n?=?61), respectively. Resistance (R5–R20), reactance (X5–X20), and resonant frequency were measured by impulse oscillometry (IOS) at 5–20?Hz.

Results: Median R5-R20 and Z5 were significantly higher and median X10 was significantly lower in PS group compared to non-PS group (p?Conclusions: This study demonstrated that passive smoking significantly increases peripheral airway resistance and seems to adversely affect lung function in children born late-preterm.  相似文献   
92.

Objective  

To estimate prevalence of malignancy and dysplasia in cervical polyps and to judge whether cervical polyps need to be removed routinely. Also to investigate if a cervical polyp is an indicator of endometrial pathology and to assess the necessity of performing dilatation and curettage (D&C).  相似文献   
93.

Purpose

Spondyloenchondrodysplasia is a rare immuno-osseous dysplasia caused by biallelic mutations in ACP5. We aimed to provide a survey of the skeletal, neurological and immune manifestations of this disease in a cohort of molecularly confirmed cases.

Methods

We compiled clinical, genetic and serological data from a total of 26 patients from 18 pedigrees, all with biallelic ACP5 mutations.

Results

We observed a variability in skeletal, neurological and immune phenotypes, which was sometimes marked even between affected siblings. In total, 22 of 26 patients manifested autoimmune disease, most frequently autoimmune thrombocytopenia and systemic lupus erythematosus. Four patients were considered to demonstrate no clinical autoimmune disease, although two were positive for autoantibodies. In the majority of patients tested we detected upregulated expression of interferon-stimulated genes (ISGs), in keeping with the autoimmune phenotype and the likely immune-regulatory function of the deficient protein tartrate resistant acid phosphatase (TRAP). Two mutation positive patients did not demonstrate an upregulation of ISGs, including one patient with significant autoimmune disease controlled by immunosuppressive therapy.

Conclusions

Our data expand the known phenotype of SPENCD. We propose that the OMIM differentiation between spondyloenchondrodysplasia and spondyloenchondrodysplasia with immune dysregulation is no longer appropriate, since the molecular evidence that we provide suggests that these phenotypes represent a continuum of the same disorder. In addition, the absence of an interferon signature following immunomodulatory treatments in a patient with significant autoimmune disease may indicate a therapeutic response important for the immune manifestations of spondyloenchondrodysplasia.
  相似文献   
94.
95.
96.
97.
The aim of this prospective study was to research features of insulin resistance and metabolic syndrome in offspring of diabetic parents and to find out whether there is a risk of developing type 2 diabetes mellitus (DM) in these children. Study participants were 30 children of parents with type 1 DM (DM1) (Group I) and 11 children of parents with type 2 DM (DM2) (Group II) who were being followed up in the Diabetes Department of Haseki Research and Training Hospital. The results were compared with a control group of 17 children in the same age group (Group III). There were no statistically significant differences between the Group I and the control group in fasting blood glucose, oral glucose tolerance test values, 1st 2nd and hour insulin, homeostasis model assessment (HOMA) values, body mass index (BMI), systolic and diastolic blood pressure, and lipid parameters, i.e. HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, total cholesterol, and triglycerides. Fasting, 1st and 2nd hour blood insulin levels, HOMA values, BMI, and systolic blood pressure values were significantly higher in Group II compared to the control group (p < 0.05). There were no statistically significant differences between Group II and the control group in lipid parameters, fasting blood glucose, OGTT values, or diastolic blood pressure. We conclude that in our population there is a tendency of insulin resistance and metabolic syndrome in the offspring of parents with DM2, and a risk for developing DM2. Thus, children of patients with DM2 should be followed up so as to recognize early metabolic defects of glucose metabolism and to plan effective preventive efforts to reduce cardiovascular and atherosclerotic risk factors.  相似文献   
98.
The aim of the study was to investigate the distribution and differentiation of cell types in the stroma of human placental stem villi (SV). A total of 14 human term placental tissues were studied. Double immunolabeling was performed for desmin-vimentin, desmin--smooth actin and vimentin--smooth actin. Cytokeratin 7, proliferating cell nuclear antigen immunolabeling was also performed. Parallel tissue samples were examined by transmission electron microscopy. HSCORE was performed for the semi-quantitative analysis of distribution of cells in the stroma of SV. Vimentin-labeled cells were mostly distributed in the subtrophoblastic area. Desmin-vimentin double immunolabeling was mainly localized in the triangular area and to a lesser degree in the perivascular area and vessel walls (p=<0.001). However, desmin- smooth actin labeling was observed predominantly in the vessel wall and perivascular area. Vimentin- smooth actin immunoreactivity was significantly stronger in the triangular and perivascular areas compared to the vessel walls (p=0.003).

Ultrastructurally, cells in the stroma of SV were mesenchyme cells, reticulum cells, fibroblasts, myofibroblasts, smooth muscle cells, and Hofbauer cells, filamented and vacuolated cells. The differentiation of myofibroblasts in the triangular and perivascular areas may play a role in maturation of SV and villous contractility, modulation of the intervillous space and this may have effects on maternofetal placental circulation.  相似文献   

99.
Tularemia outbreaks have occurred in various regions of Turkey in recent years. In this study, clinical (145 patients) and laboratory (97 patients) features of patients with oropharyngeal tularemia were evaluated during the tularemia outbreak in the district of Gölcük in Kocaeli, Turkey. We analyzed the risk factors for therapeutic failure and prolonged recovery time, and compared the efficacy of three antibiotic groups, namely aminoglycoside, tetracycline and quinolone. The most common physical sign and laboratory findings in patients were lymphadenopathy (LAP) and increased erythrocyte sedimentation rate, respectively. Treatment failure was observed in 55 of the 145 (38%) patients during one‐year follow‐up and the most successful results were obtained in the quinolone group. It was determined that antimicrobial therapy initiated 14 days after onset of symptoms was a statistically significiant risk factor, reducing the success rate (p=0.0001, OR=13.10, 95% CI=5.69–30.15) and prolonging the recovery period (p=0.001, OR=3.23, 95% CI=1.63–6.40) in oropharyngeal tularemia cases. These results suggest that antimicrobial treatment should be started early, and quinolones such as moxifloxacin and ciprofloxacin seem to be new alternatives in the treatment of oropharyngeal tularemia.  相似文献   
100.
We aimed to examine the sensitivity and specificity of the Ankara University Cerebral Dominance Inventory (AUCDI) in determining left cerebral dominance compared with the Wada test. The AUCDI and Wada test were applied to 49 patients referred to Ankara University for epilepsy surgery. Hand, foot and ‘total’ preference scores were specified according to the results of the inventory. Thirty-eight of the patients had left cerebral dominance and 11 had atypical cerebral dominance for language. 86 % of the patients were right-handed and 43 % were right-footed. When compared with the results of the Wada test, the sensitivity of the AUCDI for each ‘total preference’, and hand and foot preference was 90, 95 and 50 % and specificity was 46, 46 and 82 %, respectively. The percentage of right-footed patients was low when compared with the other studies. This difference might result from the method used for assessing foot preference by the actual demonstration of the task rather than just asking about the performance. The AUCDI was found to be sensitive in terms of ‘total preference’ and hand preference, and specific in terms of foot preference for determining the left hemisphere dominance in patients preferring the right side. It was a cheap and noninvasive alternative to the Wada test, appropriate for clinical bedside evaluation.  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