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   390篇
  免费   7篇
  国内免费   1篇
耳鼻咽喉   17篇
儿科学   32篇
妇产科学   28篇
基础医学   34篇
口腔科学   11篇
临床医学   29篇
内科学   44篇
皮肤病学   8篇
神经病学   17篇
特种医学   52篇
外科学   60篇
综合类   2篇
预防医学   11篇
眼科学   5篇
药学   35篇
中国医学   2篇
肿瘤学   11篇
  2023年   4篇
  2022年   8篇
  2021年   14篇
  2020年   7篇
  2019年   10篇
  2018年   7篇
  2017年   9篇
  2016年   8篇
  2015年   12篇
  2014年   9篇
  2013年   21篇
  2012年   23篇
  2011年   30篇
  2010年   21篇
  2009年   14篇
  2008年   44篇
  2007年   39篇
  2006年   29篇
  2005年   27篇
  2004年   24篇
  2003年   9篇
  2002年   15篇
  2000年   1篇
  1999年   3篇
  1997年   3篇
  1996年   1篇
  1994年   2篇
  1991年   1篇
  1970年   1篇
  1968年   1篇
  1967年   1篇
排序方式: 共有398条查询结果,搜索用时 31 毫秒
71.
BackgroundAbdominal aortic aneurysm (AAA) has risk factors similar to those of atherosclerosis. Salusin-β and arterial stiffness are novel parameters that have been shown to predict atherosclerosis and related cardiovascular disorders. However, their predictive value for detecting AAA remains unclear.MethodsForty-eight patients with AAA and 47 age- and sex-matched participants without AAA were enrolled in the study. Arterial stiffness parameters were obtained via an oscillometric Mobil-O-Graph PWA Monitor device (IEM GmbH) with integrated ARCSolver software (Australian Institute of Technology). Plasma salusin-β levels were analyzed using an enzyme-linked immunosorbent assay reagent kit (Abbkine, Inc). The measured salusin-β levels and arterial stiffness parameters of the AAA and control groups were compared.ResultsSalusin-β levels were significantly lower in patients with AAA (P = .014). There was a significant negative correlation between salusin-β levels and abdominal aorta diameter. No significant difference was detected between AAA and control groups in terms of arterial stiffness parameters (P > .05). In backward multiple regression analysis, the presence of AAA, platelet count, and augmentation index were found to be independent predictors of salusin-β levels (P = .006 and P = .023, respectively).ConclusionArterial stiffness parameters were not found to be associated with AAA. Contrary to previous results regarding atherosclerosis and related cardiovascular disorders, salusin-β levels were found to be lower in patients with AAA. Although AAA is thought to have similar risk factors as atherosclerosis, the exact pathophysiologic mechanism remains unclear.  相似文献   
72.
Periostin is an extracellular matrix protein from fasciclin family, and it plays an important role in the cell adhesion, migration, and growth of the organism. Periostin prevents apoptosis while stimulating cardiomyocytes. The present study was designed to investigate cardioprotective effects of the recombinant murine periostin peptide administration in a rat model of isoproterenol (ISO)-induced myocardial injury. The experiment was performed on 84 adult male Sprague Dawley rats in 4 groups (n = 21): control group (1), periostin-treated group (2), ISO-treated group (3), and ISO + periostin-treated group (4). The groups were further divided into three subgroups based on the duration of the experiment in which rats were killed on days 1, 7, and 28 (n = 7). Growth factors (VEGF, ANGPT, FGF-2, TGFβ), mitosis and apoptosis (Bcl-2, Bax, PCNA, Ki-67, phospho-histone H3), cell cycle activators and inhibitors (cyclin D1, D2, A2, Cdc2), the origin of regenerating cells (cKit and CD45) mRNA were detected using quantitative real-time polymerase chain reaction (PCR) and PCR array. Immunohistochemistry staining was used to directly detect protein level and distribution in the heart tissues. Administration of periostin following ISO-induced cardiotoxicity revealed that periostin alleviated deleterious effects of ISO through several pathways: (1) periostin induced mitotic activity of endothelial/fibroblastic cells, (2) periostin drives cardiomyocytes into S and M phases, thus promoting proliferation of cardiomyocytes, (3) periostin contributed to collagen degradation, tissue remodeling, and reduced cardiac fibrosis during the healing process following myocardial damage while preserving tissue matrix, (4) periostin stimulated angiogenesis by upregulating THBS1, TGFB2, and HGF genes, (5) periostin regulated cell growth and proliferation while maintaining cell shape and cellular muscle contractions (ACTB) and functioned as chemoattractant factor (CCL2) at the beginning of myocardial damage.  相似文献   
73.
Intraosseous lipoma of the calcaneus is a benign lesion formed by mature adipose tissue. When the lesion is symptomatic, the most frequent presentation is localized pain and soft tissue swelling. Because these lesions can regress spontaneously, conservative treatment methods are recommended. Operative excision is mostly required for painful lesions and pathologic fractures. The data from 14 patients with calcaneal intraosseous lipoma, who had undergone surgery in our clinic, were evaluated retrospectively. Using Milgram’s classification system, 9 lesions were classified as stage 1, 4 as stage 2, and 1 as stage 3. All lesions were occupying 100% of intracalcaneal cross-section in the coronal plane and >30% in the sagittal plane of magnetic resonance imaging sections. The mean preoperative visual analog scale score was 5.29 ± 1.14 (range 4 to 7), and the mean postoperative visual analog scale score at the last follow-up visit was 1.14 ± 0.36 (range 1 to 2), which was significantly better (p < .01). The mean Maryland foot score at the last follow-up visit was 97.71 ± 2.02 (range 95 to 100). The mean American Orthopaedic Foot and Ankle Society Ankle-Hindfoot scale score was 97.86 ± 2.11 (range 94 to 100) at the last follow-up visit. The differences between the pre- and postoperative values were statistically significant (p < .01). No recurrence had been detected within a median follow-up period of 84 months. Operative management of symptomatic lesions related to intraosseous lipoma of the calcaneus provides better results compared with the preoperative state.  相似文献   
74.
75.
BackgroundIn this study, benzothiazole-piperazine compounds were synthesized by condensing the functional groups of donepezil (DNP), FK-960, and sabeluzole, which are known to have therapeutic potential against Alzheimer's disease, with the aim of obtaining new and potent anti-Alzheimer agents.MethodsInitially, acetylcholinesterase/butyrylcholinesterase enzyme inhibition activities of the synthesized test compounds were investigated by Ellman's method. Effects of the compounds on a streptozotocin (STZ) model of Alzheimer's disease (SMAD) were investigated in rats. SMAD was established by intracerebroventricular (icv) injection of STZ (3 mg/kg), bilaterally. The elevated plus maze, Morris water maze, and active avoidance tests were used to examine the effects of test compounds (1,5, and 10 mg/kg) on learning and memory parameters of icv STZ-injected rats. Effects of the test compounds on spontaneous locomotor activities of rats were examined with the activity cage test.ResultsThe compounds B2–B5 and DNP exhibited significant selective inhibitory potencies against acetylcholinesterase. Compounds B2 and B3 at 10 mg/kg doses and compounds B4 and B5 at 5 and 10 mg/kg doses, as well as the reference drug DNP (1 and 3 mg/kg), significantly improved the learning and memory parameters of animals in all cognition tests. None of the test compounds changed spontaneous locomotor activities.ConclusionResults of the present study revealed that compounds B2-B5 repaired the parameters related to the learning and memory deficits of icv STZ-injected rats. Potencies of these test compounds were comparable to the activity of DNP.  相似文献   
76.
77.
78.
79.
BACKGROUND AND AIM: The effects of cholesterol supplementation on antioxidant enzyme activities were investigated hepatic tissue taken from Sprague Dawley rats. METHODS AND REULTS: The study involved 14 male Sprague Dawley rats: seven fed a normal laboratory diet and seven a normal diet plus cholesterol (3.6 g/kg/day) for three months, during which blood samples were obtained to measure serum cholesterol levels. At the end of the 3-month period, the livers were surgically removed in order to measure antioxidant enzyme activities (superoxide dismutase, catalase, glutathione peroxidase and paraoxonase-1). At the end of the study period, serum total cholesterol and HDL-cholesterol levels were significantly higher in the cholesterol-fed group than the control group. There were no significant between-group differences in hepatic superoxide dismutase, catalase and glutathione peroxidase activities, but there was a significant decrease in hepatic paraoxonase-1 activity in the cholesterol-fed group. CONCLUSIONS: Cholesterol supplementation significantly decreases paraoxonase-1 activity in rat liver tissue without changing the activities of other antioxidant enzymes. These results suggest that cholesterol significantly suppresses hepatic paraoxonase-1 synthesis. It seems that the decreased paraoxinase-1 activity in the plasma HDL-fraction of atherosclerotic patients is associated with suppressed liver synthesis. A reduction in paraoxonase-1 activity may therefore lead to the more intensive exposure of LDL to oxidant attacks.  相似文献   
80.
Abnormal location of the spleen, which is called wandering spleen, results from laxity or absence of the splenic pedicle. In the presence of an elongated splenic pedicle, torsion of the spleen or neighboring organs may occur, which results in acute or chronic abdominal pain. In this case report, we present imaging findings of a wandering spleen that manifested with volvulus of the pancreas.  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