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   167篇
  免费   9篇
儿科学   34篇
妇产科学   17篇
基础医学   17篇
口腔科学   2篇
临床医学   10篇
内科学   36篇
皮肤病学   1篇
神经病学   2篇
特种医学   4篇
外科学   25篇
综合类   2篇
预防医学   8篇
眼科学   2篇
药学   15篇
肿瘤学   1篇
  2023年   1篇
  2022年   2篇
  2021年   4篇
  2020年   1篇
  2019年   4篇
  2018年   1篇
  2016年   9篇
  2015年   5篇
  2014年   4篇
  2013年   8篇
  2012年   13篇
  2011年   12篇
  2010年   8篇
  2009年   7篇
  2008年   7篇
  2007年   9篇
  2006年   10篇
  2005年   10篇
  2004年   16篇
  2003年   3篇
  2002年   2篇
  2001年   1篇
  2000年   4篇
  1999年   4篇
  1997年   2篇
  1996年   3篇
  1992年   2篇
  1991年   5篇
  1990年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1983年   2篇
  1982年   2篇
  1980年   1篇
  1979年   5篇
  1971年   2篇
  1969年   1篇
  1968年   2篇
排序方式: 共有176条查询结果,搜索用时 15 毫秒
1.
2.
The purpose of this study was to determine the prevalence of suicide attempts, and to identify the risk factors for suicide attempts in Turkish children and adolescents between the ages 10 and 20 years. Multi-step, stratified, cluster sampling was used. A stratified sample of 4256 students was selected as representative of the city's school children population. Data was obtained with a pair of structured questionnaires designed to evaluate the presence and risk factors of suicide attempts, both in the children and adolescents and their parents. These questionnaires investigated family environment, subject characteristics, and various risk factors for suicide attempts. Child Beck Depression Inventory (CBDI) was administered to all children and adolescents. After the data quality control process, the study sample was reduced to 4143 children and adolescents. Children and adolescents were divided two groups according to the experience or non-experience of suicide attempts: group 1 (n=80) and group 2 (n=4063), respectively. Three categories of independent variables were assessed: adolescent, family, and socioeconomic characteristics. Logistic regression models were based on the children and adolescents and on parent reports. The prevalence of suicide attempts as reported by the children and adolescents was 1.93% (n=80).The mean age of group 1 was higher than that of group 2 (p=0.002, t=-3.172), as was the mean score of CBDI (p=0.000, t=-9.083). Logistic regression analysis indicated that having problems with parents, using illicit drugs, and psychiatric problems in relatives best predicted suicide attempts in Turkish children and adolescents.  相似文献   
3.
4.
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   
5.
6.
Brain abscess due to Entamoeba histolytica (E. histolytica) may pose a diagnostic problem or a therapeutic challenge, as evidenced by the paucity of papers reporting complete recovery after treatment. An 11-year-old girl presented with progressive drowsiness, diminished movements of the left upper limb, and swallowing problems. Cranial MRI showed multiple, contrast-dense masses with fluid content. She was started on meropenem. Surgical drainage was performed. No bacterial or fungal growth was observed in drainage samples. Entamoeba histolytica trophozoites were detected in the tissue sample. Intravenous metronidazole was started and continued for 6 weeks, at the end of which abscesses were found and to have shrunk considerably. Intravenous therapy was switched to oral metronidazole, which was continued for 2 weeks. She regained all her preexisting abilities. Multiple brain abscesses due to E. histolytica is a very rare occurrence, and histopathologic evaluation is important in diagnosis.Brain abscess, a rare form of Entamoeba histolytica (E. histolytica) infection, is characterized by an abrupt onset of symptoms and rapid progression and early death if untreated. Although many erroneously consider it as a disease of economically-developing countries, brain abscess due to E. histolytica may pose a diagnostic problem or a therapeutic challenge as evidenced by the paucity of papers reporting complete recovery after treatment. Extra-abdominal amebiasis, including cerebral amebic abscess, develops as a complication of hepatic amebiasis, rather than direct dissemination from the intestine. Cerebral amebic abscess disease has an incubation period starting from a few days to several months. As cerebral bacterial infections have a medical profile similar to that of protozoans (including partial muscular weakness, lethargy, and headache) differential diagnosis is difficult. The aim of the current study is to present a case of a brain abscess not associated with hepatic amebiasis.1-3 Multiple brain abscesses due to E. histolytica is a rarely seen occurrence. Serological and histopathological evaluations may prove to be very important in the diagnosis.  相似文献   
7.
8.
Determination of risk of severe bacterial infection complication in children with cancer is important to diminish the cost of hospitalization and therapy. In this study, children with cancer (leukemia excluded) were evaluated for risk of severe infection complication, success of therapy and the relation between clinical and inflammatory parameters during neutropenic fever attacks. Children who fulfilled the criteria of neutropenic fever with cancer were enrolled in the study. During admission, together with clinical and laboratory parameters; interleukin-6, interleukin-8, soluble tumor necrosis factor receptor II, and soluble interleukin 2 reseptor ve procalcitonin levels were detected. Empirical therapy was started with piperacillin/tazobactam and relation between the inflammatory cytokine levels and therapy response parameters were evaluated. The study population included 31 children and 50 neutropenic attacks were studied. In 48% of the attacks, absolute neutrophile count was >100/mm3 and infectious agents were shown microbiologically in 12% of the attacks. In the study group with piperacillin/tazobactam monotherapy, the success rate without modification was 58%. In the therapy modified group mean duration of fever, antibiotherapy and hospitalization were significantly longer than the group without modification. Inflammatory cytokines’ levels during admission (interleukin-6, interleukin-8, soluble tumor necrosis factor reseptor II) were higher in patients with fever >3 days and in multiple regression analysis, it has been shown that they have a determinative role on fever control time. Other cytokines did not show any significant relationship with risk of severe bacterial infection complication and success of therapy.  相似文献   
9.
This study reports substantial improvement in the process for oxidising α-pinene, using environmentally friendly H2O2 at high atom economy (∼93%) and selectivity to α-pinene oxide (100%). The epoxidation of α-pinene with H2O2 was catalysed by tungsten-based polyoxometalates without any solvent. The variables in the screening parameters were temperatures (30–70 °C), oxidant amount (100–200 mol%), acid concentrations (0.02–0.09 M) and solvent types (i.e., 1,2-dichloroethane, toluene, p-cymene and acetonitrile). Screening the process parameters revealed that almost 100% selective epoxidation of α-pinene to α-pinene oxide was possible with negligible side product formation within a short reaction time (∼20 min), using process conditions of a 50 °C temperature in the absence of solvent and α-pinene/H2O2/catalyst molar ratio of 5 : 1 : 0.01. A kinetic investigation showed that the reaction was first-order for α-pinene and catalyst concentration, and a fractional order (∼0.5) for H2O2 concentration. The activation energy (Ea) for the epoxidation of α-pinene was ∼35 kJ mol−1. The advantages of the epoxidation reported here are that the reaction could be performed isothermally in an organic solvent-free environment to enhance the reaction rate, achieving nearly 100% selectivity to α-pinene oxide.

Products obtained from the oxidation of α-pinene with hydrogen peroxide (H2O2) in the presence of tungsten-based polyoxometalates (α-pinene 1, α-pinene oxide 2, pinanediol 3, campholenic aldehyde 4, sobrerol 5, verbenol 6 and verbenone 7).  相似文献   
10.
Partial airway obstruction due to the enlargement of the tonsils and adenoids is a well recognized clinical entity, but cardiorespiratory changes due to chronic obstruction have infrequently been reported. Four children with severe nasopharyngeal obstruction due to tonsil and adenoid hypertrophy, who developed pulmonary hypertension and cardiac failure, were studied. Relief of upper airway obstruction by adenotonsillectomy resulted in a regression of the presenting signs and symptoms.  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