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   117篇
  免费   2篇
儿科学   9篇
妇产科学   3篇
基础医学   26篇
临床医学   2篇
内科学   27篇
神经病学   2篇
外科学   9篇
综合类   5篇
预防医学   16篇
药学   9篇
中国医学   2篇
肿瘤学   9篇
  2023年   4篇
  2022年   5篇
  2021年   8篇
  2020年   1篇
  2018年   1篇
  2017年   5篇
  2016年   4篇
  2015年   3篇
  2014年   11篇
  2013年   10篇
  2012年   14篇
  2011年   10篇
  2010年   6篇
  2009年   5篇
  2008年   3篇
  2007年   2篇
  2006年   5篇
  2005年   4篇
  2004年   5篇
  2003年   7篇
  2002年   1篇
  2001年   1篇
  2000年   2篇
  1999年   1篇
  1994年   1篇
排序方式: 共有119条查询结果,搜索用时 15 毫秒
71.
72.
Malignant Solitary Fibrous Tumor of the Pleura   总被引:2,自引:0,他引:2  
We describe a case of malignant solitary fibrous tumor of the pleura in a 15-year-old female who presented clinically with back pain. Grossly, the tumor had a pedicle attached to the pleura and histologically showed Proliforating spindle-shaped cells with a high mitotic index. Immunohistochemical and ultrastructural features were consistent with a tumor of fibroblastic origin. Flow cytometric DNA analysis revealed an aneuploid population among the tumor cells.  相似文献   
73.
Carboxymethyl cellulose (CMC) powder formulation of apomorphine was prepared by lyophilization and characterized with respect to the in vitro and intranasal in vivo release of apomorphine in rabbits. This was compared to apomorphine release from degradable starch microspheres (DSM) and lactose, as well as in vivo absorption after subcutaneous injection. In vitro apomorphine release from CMC was sustained, unlike that of DSM and lactose. Changing the drug loading of CMC from 15 to 30% (w/w) influenced drug release rate, which increased with increased drug loading. In vivo absorption of apomorphine from lactose, DSM and subcutaneous injection were rapid and not sustained. Slower absorption rates of apomorphine occurred from CMC. The fastest absorption rate was obtained with lactose and the slowest with CMC of 15% (w/w) drug loading. The T(max) from the CMC dosage forms were significantly prolonged compared to the immediate release forms. Plasma drug levels were sustained with CMC. The plasma concentration was maintained within 50% of the C(max), longer (15% (w/w), 70 min; 30% (w/w), 40 min) compared to the rest (lactose, 20 min; DSM, 25 min, subcutaneous injection, 35 min). The sustained plasma level of apomorphine by CMC was achieved with relative bioavailabilities equivalent to subcutaneous injection.  相似文献   
74.
Information on the economic burden of malaria in Africa is needed to target interventions efficiently and equitably, and to justify investment in research and control. A standard method of estimation has been to sum the direct costs of expenditure on prevention and treatment, and the indirect costs of productive labour time lost. This paper discusses the many problems in using such data to reflect the burden to society or the potential benefits from control. Studies have generally focussed on febrile illness, overestimating the burden of uncomplicated malaria, but underestimating the costs of severe illness, other debilitating manifestations, and mortality. Many use weak data to calculate indirect costs, which fail to account for seasonal variations, the difference between the average and marginal product of labour, and the ways households and firms 'cope' in response to illness episodes. Perhaps most importantly, the costs of coping mechanisms in response to the risk of disease are excluded, although they may significantly affect productive strategies and economic growth. Future work should be rooted in a sound understanding of the health burden of malaria and the organisation of economic activities, and address the impact on the productive environment, and epidemiological and socio-economic geographical variation.  相似文献   
75.
Surgical treatment of valvular heart disease in Nigeria, the most populous country in sub-Saharan Africa, is adversely affected by socioeconomic factors such as poverty and ignorance. To evaluate our experience in this context, we identified all patients who underwent surgery for acquired or congenital valvular heart disease at our Nigerian center from February 2013 through January 2019. We collected data from their medical records, including patient age and sex, pathophysiologic causes and types of valvular disease, surgical treatment, and outcomes. Ninety-three patients (43 males [46.2%]; mean age, 38.9 ± 10.0 yr [range, 11–80 yr]) underwent surgical treatment of a total of 122 diseased valves, including 72 (59.0%) mitral, 26 (21.3%) aortic, 21 (17.2%) tricuspid, and 3 (2.5%) pulmonary. The most prevalent pathophysiologic cause of disease was rheumatic (87 valves [71.3%]), followed by functional (20 [16.4%]), congenital (8 [6.6%]), degenerative (5 [4.1%]), and endocarditic (2 [1.6%]). All 3 diseased pulmonary valves had annular defects associated with congenital disease. Surgical treatment included mechanical prosthetic replacement of 92 valves (75.4%), surgical repair of 29 (23.8%), and bioprosthetic replacement of 1 (0.8%). We conclude that, in Nigeria, valvular disease is mainly rheumatic, affects mostly younger to middle-aged individuals, and is usually treated with prosthetic replacement  相似文献   
76.
Psychological distress is more common in cancer survivors than the general population, and is associated with adverse outcomes. This cross-sectional study aimed to assess the relationship between socioeconomic status (SES), race and psychological distress, using data from a nationally representative sample of cancer survivors in the United States. Outcomes of interest were mild, moderate, and severe psychological distress as assessed by the Patient Health Questionnaire-4 (PHQ-4). In our univariate model, there was no statistically significant difference in the PHQ-4 scores of Caucasian and African American respondents. On the other hand, a lower SES correlated with a higher likelihood of psychological distress, and this persisted in our multivariate model. This study brings additional awareness to the negative impact of a lower socioeconomic status on mental health outcomes in cancer survivors, and further highlights the importance of the timely identification and screening of individuals at a high risk of psychological distress, in order to limit missed opportunities for relevant mental health interventions in this population.  相似文献   
77.
78.
The arterial baroreflex is a key mechanism for the homeostatic control of blood pressure (BP). In animals and humans, psychological stressors suppress the capacity of the arterial baroreflex to control short-term fluctuations in BP, reflected by reduced baroreflex sensitivity (BRS). While animal studies have characterized the brain systems that link stressor processing to BRS suppression, comparable human studies are lacking. Here, we measured beat-to-beat BP and heart rate (HR) in 97 adults who performed a multisource interference task that evoked changes in spontaneous BRS, which were quantified by a validated sequence method. The same 97 participants also performed the task during functional magnetic resonance imaging (fMRI) of brain activity. Across participants, task performance (i) increased BP and HR and (ii) reduced BRS. Analyses of fMRI data further demonstrated that a greater task-evoked reduction in BRS covaried with greater activity in brain systems important for central autonomic and cardiovascular control, particularly the cingulate cortex, insula, amygdala, and midbrain periaqueductal gray (PAG). Moreover, task performance increased the functional connectivity of a discrete area of the anterior insula with both the cingulate cortex and amygdala. In parallel, this same insula area showed increased task-evoked functional connectivity with midbrain PAG and pons. These novel findings provide human evidence for the brain systems presumptively involved in suppressing baroreflex functionality, with relevance for understanding the neurobiological mechanisms of stressor-related cardiovascular reactivity and associated risk for essential hypertension and atherosclerotic heart disease.  相似文献   
79.
This study investigated the morphometric changes, biochemical parameters, and kidney morphology of male West African Dwarf goats exposed to graded levels of 2,4-dichlorophenoxyacetic acid (2,4-D). Four groups of five goats were used for this experiment. Goats in three of the groups were exposed to oral administration of 2,4-D as follows: group A, low dose (75 mg/kg body weight); group B, medium dose (100 mg/kg body weight); and group C, high dose (125 mg/kg body weight); every 72 h for a period of 112 days. The group D goats served as the control and received no 2,4-D treatment. Morphometric changes, biochemical parameters, and histomorphological features of the kidney of goats exposed to 2,4-D were compared with control goats. Exposing male goats to 2,4-D treatment led to reduction in mean body weights (p < 0.05), mean blood glucose (p < 0.05), and mean total serum protein (p < 0.05) concentrations. The histomorphology of the kidney sections of the 2,4-D-treated goats was that of subacute to chronic exudative glomerulonephritis; and the severity of lesions increased with higher 2,4-D concentration. It was concluded that exposing male West African Dwarf goats to varied concentrations of 2,4-D herbicide resulted in reduction in weight gain, changes in blood glucose and total serum protein concentrations, as well as glomerular, tubular, and interstitial lesions in the kidney.  相似文献   
80.
Plasmablastic lymphoma (PBL) is an uncommon, clinically aggressive, Epstein-Barr virus-driven B-cell lymphoma that was initially described in tumors of relatively young human immunodeficiency virus-positive men. Subsequent to initial reports, the clinical and pathological spectrum of this disease has been expanded such that, now, PBL is recognized to be a heterogeneous disease entity. Plasmablastic lymphoma has been seen in clinical settings outside those initially reported and has been shown to demonstrate a variety of morphologic patterns. We describe a case of extraoral PBL in an human immunodeficiency virus-infected patient with a computed tomography-identified heterogeneously enhancing mass in the stomach. Histologically, a prominent intravascular component was identified. Fluorescent in situ hybridization analysis for MYC/IGH (immunoglobulin heavy chain) rearrangement t(8;14) identified fusion signals, confirming the presence of MYC rearrangement. The presence of a prominent intravascular in our case is unique. To our knowledge, these findings have not been observed in the previous reports of PBL. The observation of this vascular component supports the heterogeneity of PBL and may be an indicator of tumor aggressiveness. We were able to demonstrate the MYC/IGH rearrangement in our case of PBL. The interplay between Epstein-Barr virus and this MYC rearrangement may be similar to what is observed in Burkitt lymphoma, another clinically aggressive non-Hodgkin lymphoma.  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