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   436篇
  免费   38篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   23篇
妇产科学   5篇
基础医学   49篇
口腔科学   1篇
临床医学   44篇
内科学   111篇
皮肤病学   4篇
神经病学   51篇
特种医学   35篇
外科学   67篇
综合类   3篇
预防医学   23篇
眼科学   11篇
药学   34篇
肿瘤学   13篇
  2024年   4篇
  2022年   5篇
  2021年   16篇
  2020年   8篇
  2019年   5篇
  2018年   12篇
  2017年   16篇
  2016年   12篇
  2015年   16篇
  2014年   13篇
  2013年   23篇
  2012年   31篇
  2011年   36篇
  2010年   11篇
  2009年   11篇
  2008年   24篇
  2007年   19篇
  2006年   20篇
  2005年   20篇
  2004年   17篇
  2003年   27篇
  2002年   19篇
  2001年   16篇
  2000年   21篇
  1999年   15篇
  1998年   2篇
  1997年   2篇
  1996年   4篇
  1995年   1篇
  1994年   1篇
  1993年   3篇
  1992年   2篇
  1991年   5篇
  1990年   2篇
  1989年   5篇
  1988年   2篇
  1987年   1篇
  1986年   5篇
  1985年   7篇
  1984年   2篇
  1983年   1篇
  1982年   1篇
  1981年   3篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1975年   2篇
  1973年   2篇
  1966年   1篇
  1965年   1篇
排序方式: 共有475条查询结果,搜索用时 15 毫秒
1.
Adenosine monophosphate, inosine monophosphate, inosine, adenosine, guanosine, adenine, guanine, hypoxanthine, xanthine and uric acid were determined in cerebrospinal fluid (CSF) of 15 children after complex febrile seizures (CFS) and in 27 after simple febrile seizures (SFS), and compared with those in a control group of 63 children. There was no statistically significant difference between the groups for any of these metabolites, suggesting that CFS and SFS neither significantly disturb the metabolism of nucleotides, nucleosides or bases nor significantly deplete neuron adenosine triphosphate levels.  相似文献   
2.
The risk of acquiring both hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in patients with hematological-oncological disorders has been documented. However, the impact and risk factors for such infections from different geographical areas vary, and the use of both immunological and molecular assays to determine HCV infections has been our approach. Children from a hematology-oncology unit (HOU) in Nicaragua were studied for both HBV and HCV serological markers; studies for the latter used both immunological (anti-HCV) and molecular (HCV RNA) assays. The children from the HOU included patients with leukemia, lymphoma, other neoplasias, and anemia and a smaller group with other hematological diseases. As a control group, children from other units at the same hospital were enrolled, as well as health care workers attending both patient populations. Pertinent clinical and personal data for each child at the HOU were obtained for statistical analysis. Of the 625 children from the HOU enrolled in this study 53.3% were infected with HCV and 29.4% had a prior or present HBV infection. In the child patient control group 3.2% had HBV markers and all were negative for HCV. The group of children with leukemia had the highest infection rate for both HBV and HCV. However, the determination of anti-HCV was found to have an overall low sensitivity in children from HOU, and a retest consisting of a molecular assay to determine HCV RNA was performed to better establish the total number of HCV-infected subjects in this group. The highest independent risk factor for infection was hospitalization. The very high prevalence rates for both HBV and HCV infection in this patient group indicate an urgent need to implement better control of known risk factors and to consider the use of both immunological and molecular assays for HCV diagnostic purposes.  相似文献   
3.
Sensory and motor functions of the stomach, including gastric emptying and accommodation, have significant effects on energy consumption and appetite. Obesity is characterized by energy imbalance; altered gastric functions, such as rapid gastric emptying and large fasting gastric volume in obesity, may result in increased food intake prior to reaching usual fullness and increased appetite. Thus, many different interventions for obesity, including different diets, anti-obesity medications, bariatric endoscopy, and surgery, alter gastric functions and gastrointestinal motility. In this review, we focus on the role of the gastric and intestinal functions in food intake, pathophysiology of obesity, and obesity management.  相似文献   
4.
ABSTRACT

Through qualitative data collected with women affected by drug use and drug-related violence in Bogotá, this article explores the convergence of harm reduction rationales and violence prevention programming in the urban margins to advocate for women’s health empowerment and health rights as victims of intergenerational trauma and violence. We propose a methodological shift of public health praxis from street-based outreach models to intimate spaces of intervention for health outcomes embodiment 1 1 Drawing from Krieger’s (2004) conceptualisation, we define embodiment as the stories our bodies hold and how they interact with the urban environment. as we continue to develop our community health model to work with marginalised communities in the urban global South. Through this work committed to social justice in marginalised urban communities, we seek to support women’s health needs through harm reduction in historically marginalised communities in urban settings. Our results expose how multi-level gender-based violence affects women’s health in their living spaces in the urban margins. Drawing from women’s voices and narratives of urban violence, we call for a feminist alternative to traditionally masculinist and public-space oriented harm reduction practice for health empowerment in the urban margins.  相似文献   
5.
The aim of this study was to examine whether breastfeeding may reduce the programming effect of birthweight on abdominal adiposity. Abdominal (in three regions: R1, R2 and R3) adiposity was measured by dual energy x‐ray absorptiometry in 314 adolescents. Breastfeeding duration, birthweight, duration of gestation and maternal educational level were obtained from questionnaire. Physical activity was objectively measured. We detected significant interactions between breastfeeding and birthweight on abdominal adiposity (Ps = 0.02–0.07). We observed that birthweight was associated with abdominal adiposity in the group who had never been breastfed (β = ?0.19 to ?0.23; Ps < 0.05), while no association was found in adolescents who had breastfeeding for ≥3 months (β = ?0.03 to ?0.07). The results were independent of duration of gestation, age, sex, maternal educational level and physical activity. Breastfeeding may reduce the adverse influence conferred by low birthweight on abdominal adiposity in adolescents.  相似文献   
6.
7.
OBJECTIVES: Changes in extracellular matrix glycosaminoglycans (GAGs) of the intestinal mucosa have been associated with inflammatory bowel disease. The aim of the present study was to follow the changes in GAGs metabolism during the progression from non-inflamed to inflamed intestinal colon of patients with Crohn's disease (CD), using direct biochemical analysis and specific immunohistochemistry against chondroitin/dermatan sulfate and heparan sulfate. DESIGN AND METHODS: The content of GAGs from inflamed and non-inflamed colon of eight patients with active CD was estimated by uronic acid per dry weight of tissue and analyzed by agarose gel electrophoresis and ion-exchange chromatography. Intestinal sections were stained using antibodies against dermatan sulfate/chondroitin 4-sulfate (DS/CS), heparan sulfate (HS), and ICAM-1 (CD54), and analyzed by confocal microscopy. RESULTS: There was a reduction in the amount of GAGs in the non-inflamed colon of patients with CD. In the inflamed colon, HS, CS and DS showed increased concentrations compared with the non-inflamed colon. GAGs showed a diffuse distribution in the lamina propria and in the basement membrane of both inflamed and non-inflamed mucosa of patients with CD. CONCLUSION: We observed a marked reduction in GAGs with altered patterns of distribution in the non-inflamed colon of patients with CD. The increase in the synthesis of GAGs observed in the inflamed colon may be a compensatory mechanism for the restoration of the integrity of the intestinal mucosa.  相似文献   
8.
9.
Metal hip replacements generate both metal particles and ions. The biological effects of peri-articular exposure to nanometre and micron sized cobalt chrome (CoCr) wear particles were investigated in a mouse model. Mice received injections of two clinically relevant doses of nanoparticles (32 nm), one of micron sized (2.9 μm) CoCr particles or vehicle alone into the right knee joint at 0, 6, 12 and 18 weeks. Mice were analysed for genotoxic and immunological effects 1, 4 and 40 weeks post exposure. Nanoparticles but not micron particles progressively corroded at the injection site. Micron sized particles were physically removed. No increase of Co or Cr was seen in peripheral blood between 1 and 40 weeks post exposure to particles. No significant inflammatory changes were observed in the knee tissues including ALVAL or necrosis. DNA damage was increased in bone marrow at one and forty weeks and in cells isolated from frontal cortex at 40 weeks after injection with nanoparticles. Mice exposed to the micron sized, but not nanoparticles became immunologically sensitized to Cr(III), Cr (VI) and Ni(II) over the 40 week period as determined by lymphocyte transformation and ELISpot (IFN-γ and IL-2) assays. The data indicated that the response to the micron sized particles was Th1 driven, indicative of type IV hypersensitivity. This study adds to understanding of the potential adverse biological reactions to metal wear products.  相似文献   
10.
BackgroundThe prognosis for unilateral lateral medullary infarction (ULMI) is generally good but may be aggravated by respiratory failure with fatal outcome. Respiratory failure has been reported in patients with severe bulbar dysfunction and large rostral medullary lesions, but its associated factors have not been systematically studied. We aimed to assess clinical and radiological characteristics associated with respiratory failure in patients with pure acute ULMI.Materials and MethodsSeventy-one patients (median age 55 years, 59 males) with MRI-confirmed acute pure ULMI were studied retrospectively. Clinical characteristics were assessed and bulbar symptoms were scored using a scale developed for this study. MRI lesions were classified into 4 groups based on their vertical extent (localized/extensive) and the involvement of the open and/or closed medulla. Clinical characteristics, bulbar scores and MRI lesion characteristics were compared between patients with and without respiratory failure.ResultsRespiratory failure occurred in 8(11%) patients. All patients with respiratory failure were male (p = 0.336), had extensive lesions involving the open medulla (p = 0.061), progression of bulbar symptoms (p=0.002) and aspiration pneumonia (p < 0.001). Peak bulbar score (OR, 7.9 [95% CI, 2.3–160.0]; p < 0.001) and older age (OR, 1.2 [95%CI, 1.0-1.6]; p=0.006) were independently associated with respiratory failure.ConclusionsExtensive damage involving the open/rostral medulla, clinically presenting with severe bulbar dysfunction, in conjunction with factors such as aspiration pneumonia and older age appears to be crucial for the development of respiratory failure in pure ULMI. Further prospective studies are needed to identify other potential risk factors, pathophysiology, and effective preventive measures for respiratory failure in these patients.  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