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   523篇
  免费   39篇
  国内免费   3篇
耳鼻咽喉   17篇
儿科学   9篇
妇产科学   12篇
基础医学   61篇
口腔科学   11篇
临床医学   66篇
内科学   115篇
皮肤病学   16篇
神经病学   45篇
特种医学   11篇
外科学   49篇
预防医学   49篇
眼科学   15篇
药学   42篇
中国医学   7篇
肿瘤学   40篇
  2024年   1篇
  2023年   8篇
  2022年   6篇
  2021年   43篇
  2020年   17篇
  2019年   46篇
  2018年   31篇
  2017年   15篇
  2016年   15篇
  2015年   22篇
  2014年   22篇
  2013年   35篇
  2012年   64篇
  2011年   53篇
  2010年   46篇
  2009年   23篇
  2008年   22篇
  2007年   28篇
  2006年   14篇
  2005年   18篇
  2004年   13篇
  2003年   11篇
  2002年   11篇
  2000年   1篇
排序方式: 共有565条查询结果,搜索用时 20 毫秒
11.
D-Fraction is protein-bound β-1,6 and β-1,3 glucans (proteoglucan) extracted from the edible and medicinal mushroom Grifola frondosa (Maitake). The antitumoral effect of D-Fraction has long been exclusively attributed to their immunostimulatory capacity. However, in recent years increasing evidence showed that D-Fraction directly affects the viability of canine and human tumor cells, independent of the immune system. Previously, we have reported that D-Fraction modulates the expression of genes associated with cell proliferation, cell death, migration, invasion, and metastasis in MCF7 human breast cancer cells. Therefore, the purpose of the current study is to investigate if this modulation of gene expression by Maitake D-Fraction really modulates tumor progression. In the present work, we demonstrate for the first time that Maitake D-Fraction is able to act directly on mammary tumor cells, modulating different cellular processes involved in the development and progression of cancer. We demonstrate that D-Fraction decreases cell viability, increases cell adhesion, and reduces the migration and invasion of mammary tumor cells, generating a less aggressive cell behavior. In concordance with these results, we also demonstrate that D-Fraction decreases tumor burden and the number of lung metastases in a murine model of breast cancer.  相似文献   
12.
This is a summary of a presentation made in the symposium “Improved Continuous Quality Care in Patients with Pressure Ulcers and Chronic Injuries”, which was held in Toledo in 2009. A 76 year old woman had been assessed (she belonged to the age group that frequently suffers this condition). She lived in a social healthcare centre and had a III stage sacral pressure ulcer. Using Gordon's Functional Health Patterns for assessing “Acute pain”, a nursing diagnosis is described and the nursing care plan has been presented according to NANDA, NIC, NOC taxonomy. The aim of this article is to show the importance of considering the pain in patients who suffer from this type of lesion, which, although almost always present, it is often undervalued by nursing staff, resulting in an even worse quality of life for the patient, due to both physical and psychological effects.This case shows how to assess pain in a patient with ulcers, and helps establish an individualised care plan with a priority on pain treatment and relief. As as result of the interventions carried out, a better perception of pain is achieved, thus helping to improve patient′s mobility and night rest.  相似文献   
13.
Changes with ageing in several leukocyte functions of male and female rats   总被引:6,自引:0,他引:6  
The impairment of the immune system with aging, or immunosenescence, appears to contribute to the increased morbidity and mortality of aged subjects. T cell functions and Natural Killer activity seem to be the immune responses most affected by ageing. Since the immune system works more efficiently in females than in males, we have studied the changes of several immune functions with age in rats of both sexes. In addition, we have investigated if ovariectomy, a model of menopause in rats, produces a loss of this gender-related advantage. In the present work, the changes with age (2, 6, 12, 14, 18, 22 and 24 months old) in lymphocyte chemotaxis, T lymphoproliferative response to the mitogen ConA, IL-2 release and Natural Killer activity of cells from axillary nodes and spleen of male and female rats as well as of females ovariectomized at 12 months of age have been studied. An age-related decrease was found in all investigated functions, with a slightly different evolution depending on the immune organ and gender considered. In general, the data obtained show that a certain degree of immunosenescence takes place with age in rats, with males being less immunocompetent than intact age-matched females, but showing an immune response similar to that of ovariectomized animals.  相似文献   
14.
The use of nanoparticles (NPs) for intranasal (IN) drug delivery to the brain represents a hopeful strategy to enhance brain targeting of anti-epileptic drugs. In the present work, chitosan–lecithin NPs loaded with phenytoin (PHT), were prepared using the nano-precipitation method. The spherical nature of the NPs and their stability were confirmed using scanning and transmission electron microscopy, while the average dynamic size and zeta potential were measured using dynamic light scattering. The encapsulation efficiency of PHT was higher than 60% for all prepared NPs. Release studies showed that the amount of released PHT was directly related to the amount of chitosan used. The optimum preparation, L10Ci+ was administered via the IN route, and the levels of PHT in the brain were measured in three-time points. Two experimental controls were given via the intraperitoneal (IP) and IN routes. The highest PHT amount reaching 1.01 ± 0.55% for L10Ci+, which was associated with a sustained release of PHT. These preliminary findings show that the IN delivery of PHT-loaded NPs is very promising for managing epilepsy. The direct nose-to-brain approach increases the safety margins of PHT, while the sustained release could improve patient compliance in a clinical setting.

The use of nanoparticles (NPs) for intranasal (IN) drug delivery to the brain represents a hopeful strategy to enhance brain targeting of anti-epileptic drugs.  相似文献   
15.
16.
Background: In the development of the central nervous system (CNS), neuronal migration and neuritogenesis are crucial processes for establishing functional neural circuits. This relies on the regulation exerted by several signaling molecules, which play important roles in axonal growth and guidance. The urokinase‐type plasminogen activator (uPA)—in association with its receptor—triggers extracellular matrix proteolysis and other cellular processes through the activation of intracellular signaling pathways. Even though the uPA‐uPAR complex is well characterized in nonneuronal systems, little is known about its signaling role during CNS development. Results : In response to uPA, neuronal migration and neuritogenesis are promoted in a dose‐dependent manner. After stimulation, uPAR interacts with α5‐ and β1‐integrin subunits, which may constitute an αβ‐heterodimer that acts as a uPA‐uPAR coreceptor favoring the activation of multiple kinases. This interaction may be responsible for the uPA‐promoted phosphorylation of focal adhesion kinase (FAK) and its relocation toward growth cones, triggering cytoskeletal reorganization which, in turn, induces morphological changes related to neuronal migration and neuritogenesis. Conclusions : uPA has a key role during CNS development. In association with its receptor, it orchestrates both proteolytic and nonproteolytic events that govern the proper formation of neural networks. Developmental Dynamics 243:676–689, 2014. © 2014 Wiley Periodicals, Inc.  相似文献   
17.
This study investigates whether changes in nitric oxide (NO) production participate in the cardiovascular manifestations of hypothyroidism and whether these changes are age-related. Sprague-Dawley rats aged 2 and 18 months old were treated with 0.02% methimazole (wt/vol) during 28 days. Left ventricular function was evaluated by echocardiography. Measurements of arterial blood pressure, heart rate, nitric oxide synthase (NOS) activity and NOS/caveolin-1 and -3 protein levels were performed. Hypothyroidism enhanced the age-related changes in heart function. Hypothyroid state decreased atrial NOS activity in both young and adult rats, associated with a reduction in protein levels of the three NOS isoforms in young animals and increased caveolin (cav) 1 expression in adult rats. Ventricle and aorta NOS activity increased in young and adult hypothyroid animals. In ventricle, changes in NOS activity were accompanied by an increase in inducible NOS isoform in young rats and by an increase in caveolins expression in adult rats. Greater aorta NOS activity level in young and in adult Hypo rats would derive from the inducible and the endothelial NOS isoform, respectively. Thyroid hormones would be one of the factors involved in the modulation of cardiovascular NO production and caveolin-1 and -3 tissue-specific abundance, regardless of age. Hypothyroidism appears to contribute in a differential way to aging-induced changes in the myocardium and aorta tissues. Low thyroid hormones levels would enhance the aging effect on the heart. Age-related changes in NO production participate in the cardiovascular manifestations of hypothyroidism.  相似文献   
18.
Velopharyngeal incompetence is a contributing factor to speech disorders and implies the presence of hypernasality, inappropriate nasal escape, and decreased air pressure during speech. One prosthetic treatment is a rehabilitative procedure employing a palatal lift prosthesis (PLP), which reduces hypernasality by approximating the incompetent soft palate to the posterior pharyngeal wall and consists of two parts, the anterior denture base and the palatal lifting plate, which are connected with steel wires; however, it seems difficult to reproduce the mobility of the soft palate in speaking, and it is therefore likely that the palatal lifting plate stimulates or oppresses the tissue of the soft palate and hinders rather than assists articulatory function. To avoid these disturbances we devised an adjustable PLP with a flexible conjunction between the denture base and the palatal lifting plate to obtain the optimal vertical lifting angle. The palatal plate was adapted to conform in a passive manner to the soft palate with light‐cured resin. The designed PLP simplified the procedure and reduced the number of adjustments and visits.  相似文献   
19.
20.
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