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   955篇
  免费   78篇
  国内免费   4篇
耳鼻咽喉   5篇
儿科学   37篇
妇产科学   31篇
基础医学   97篇
口腔科学   11篇
临床医学   121篇
内科学   125篇
皮肤病学   16篇
神经病学   69篇
特种医学   17篇
外科学   246篇
综合类   20篇
预防医学   96篇
眼科学   3篇
药学   116篇
中国医学   1篇
肿瘤学   26篇
  2021年   13篇
  2019年   11篇
  2018年   19篇
  2016年   13篇
  2015年   13篇
  2014年   12篇
  2013年   33篇
  2012年   24篇
  2011年   35篇
  2010年   28篇
  2009年   14篇
  2008年   31篇
  2007年   42篇
  2006年   34篇
  2005年   34篇
  2004年   32篇
  2003年   19篇
  2002年   28篇
  2001年   24篇
  2000年   24篇
  1999年   25篇
  1998年   17篇
  1993年   11篇
  1992年   25篇
  1991年   19篇
  1990年   17篇
  1989年   20篇
  1988年   11篇
  1987年   13篇
  1986年   19篇
  1985年   16篇
  1984年   16篇
  1983年   18篇
  1982年   18篇
  1981年   12篇
  1980年   13篇
  1979年   28篇
  1978年   20篇
  1977年   12篇
  1976年   20篇
  1975年   17篇
  1974年   21篇
  1973年   17篇
  1972年   14篇
  1971年   15篇
  1970年   13篇
  1969年   11篇
  1968年   12篇
  1967年   11篇
  1966年   10篇
排序方式: 共有1037条查询结果,搜索用时 31 毫秒
21.
Leukemia is one of the major diseases causing cancer‐related deaths in the young population, and its cure rate is unsatisfying with side effects on patients. Fluorouracil (5‐FU) is currently used as an anticancer drug for leukemia patients. Casticin, a natural polymethoxyflavone, exerts anticancer activity against many human cancer cell lines in vitro, but no other reports show 5‐FU combined with casticin increased the mouse leukemia cell apoptosis in vitro. Herein, the antileukemia activity of 5‐FU combined with casticin in WEHI‐3 mouse leukemia cells was investigated in vitro. Treatment of two‐drug combination had a higher decrease in cell viability and a higher increase in apoptotic cell death, the level of DNA condensation, and the length of comet tail than that of 5‐FU or casticin treatment alone in WEHI‐3 cells. In addition, the two‐drug combination has a greater production rate of reactive oxygen species but a lower level of Ca2+ release and mitochondrial membrane potential (ΔΨm) than that of 5‐FU alone. Combined drugs also induced higher caspase‐3 and caspase‐8 activities than that of casticin alone and higher caspase‐9 activity than that of 5‐FU or casticin alone at 48 hours treatment. Furthermore, 5‐FU combined with casticin has a higher expression of Cu/Zn superoxide dismutase (SOD [Cu/Zn]) and lower catalase than that of 5‐FU or casticin treatment alone. The combined treatment has higher levels of Bax, Endo G, and cytochrome C of proapoptotic proteins than that of casticin alone and induced lower levels of B‐cell lymphoma 2 (BCL‐2) and BCL‐X of antiapoptotic proteins than that of 5‐FU or casticin only. Furthermore, the combined treatment had a higher expression of cleaved poly (ADP‐ribose) polymerase (PARP) than that of casticin only. Based on these findings, we may suggest that 5‐FU combined with casticin treatment increased apoptotic cell death in WEHI‐3 mouse leukemia cells that may undergo mitochondria and caspases signaling pathways in vitro.  相似文献   
22.
23.

Background

We designed an assessment and education program which was delivered to patients prior to first outpatient appointment for bariatric surgery. We hypothesised that this program would streamline care and would lead to improved weight loss following bariatric surgery.

Methods

The program incorporates a structured general practitioners (GP) review, a patient information evening and an on-line learning package. It was introduced in September 2012. Patient flow through the program was recorded. Outcomes of the new program were compared with contemporaneously treated patients who did not undertake the pre-hospital program.

Results

All 636 patients on the waiting list for first appointment at the Alfred Health bariatric surgery clinic were invited to participate. There were 400 patients ultimately removed from the waiting list for first appointment. Of the remaining 236 patients, 229 consented to participate in the new program. The mean BMI was 47.8?±?9.2. The fail to attend first appointment rate dropped from 12 to 2.1 %. At 12 months post-bariatric surgery, patients who undertook the new program (n?=?82) had a mean excess weight loss (EWL) of 41.1?±?20.3 % where as those treated on the standard pathway (n?=?61) had a mean EWL 32?±?18.0 % (p?=?0.012).

Conclusions

The introduction of a pre-hospital education program has led to an improvement in attendance rates and early weight loss post-bariatric surgery.
  相似文献   
24.
OBJECTIVES: The purpose was to investigate managers' perceptions of organizational culture and attitudinal and behavioral reactions during and after restructuring, and to test a model linking culture to outcome. BACKGROUND: Healthcare reform has altered the work environment, but few studies have documented the impact of system changes on managers responsible for clinical services. METHODS: Survey data were collected from clinical managers (N = 104; 99) employed by 3 institutional boards in Newfoundland and Labrador in 2000 and 2002. Response rates were 57.6% and 47.7%, respectively. RESULTS: For both periods, most variable ratings were in the low range and depicted moderately, positive intercorrelations. Select culture variables, trust, and job satisfaction emerged as significant predictors of commitment. Although culture and trust exerted inconsistent effects on intent, satisfaction remained a predictor over time. CONCLUSION: The findings support the negative impact of reform on clinical managers, and the strong link between positive ratings of culture, trust, and satisfaction, and greater commitment and intent to stay. Greater attention should focus on promoting more positive cultures and work-related attitudes, and less turnover intentions.  相似文献   
25.
We followed a patient with manganese transporter deficiency due to homozygous SLC30A10 mutations from age 14 years until his death at age 38 years and present the first postmortem findings of this disorder. The basal ganglia showed neuronal loss, rhodanine‐positive deposits, astrocytosis, myelin loss, and spongiosis. SLC30A10 protein was reduced in residual basal ganglia neurons. Depigmentation of the substantia nigra and other brainstem nuclei was present. Manganese content of basal ganglia and liver was increased 16‐fold and 9‐fold, respectively. Our study provides a pathological foundation for further investigation of central nervous system toxicity secondary to deregulation of manganese metabolism. Ann Neurol 2014;75:608–612  相似文献   
26.
Tetrandrine (TET) has been reported to induce anti‐cancer activity in many human cancer cells and also to inhibit cancer cell migration and invasion. However, there are no reports to show TET inhibits cell migration and invasion in human brain glioblastoma multiforme GBM 8401 cells. In this study, we investigated the anti‐metastasis effects of TET on GBM 8401 cells in vitro. Under sub‐lethal concentrations (from 1, 5 up to 10 μM), TET significantly inhibited cell mobility, migration and invasion of GBM 8401 cells that were assayed by wound healing and Transwell assays. Gelatin zymography assay showed that TET inhibited MMP‐2 activity in GBM 8401 cells. Western blotting results indicated that TET inhibited several key metastasis‐related proteins, such as p‐EGFR(Tyr1068), SOS‐1, GRB2, Ras, p‐AKT(Ser473) and p‐AKT(Thr308), NF‐κB‐p65, Snail, E‐cadherin, N‐cadherin, NF‐κB, MMP‐2 and MMP‐9 that were significant reduction at 24 and 48 hours treatment by TET. TET reduced MAPK signaling associated proteins such as p‐JNK1/2 and p‐c‐Jun in GBM 8401 cells. The electrophoretic mobility shift (EMSA) assay was used to investigate NF‐κB and DNA binding was reduced by TET in a dose‐dependently. Based on these findings, we suggested that TET could be used in anti‐metastasis of human brain glioblastoma multiforme GBM 8401 cells in the future.  相似文献   
27.
28.
Peroxisome proliferator-activated receptor gamma (PPAR gamma) agonists, including the glitazone class of drugs, are insulin sensitizers that reduce glucose and lipid levels in patients with type 2 diabetes mellitus. To more fully understand the molecular mechanisms underlying their therapeutic actions, we have characterized the effects of the potent, tyrosine-based PPAR gamma ligand GW1929 on serum glucose and lipid parameters and gene expression in Zucker diabetic fatty rats. In time-course studies, GW1929 treatment decreased circulating FFA levels before reducing glucose and triglyceride levels. We used a comprehensive and unbiased messenger RNA profiling technique to identify genes regulated either directly or indirectly by PPAR gamma in epididymal white adipose tissue, interscapular brown adipose tissue, liver, and soleus skeletal muscle. PPAR gamma activation stimulated the expression of a large number of genes involved in lipogenesis and fatty acid metabolism in both white adipose tissue and brown adipose tissue. In muscle, PPAR gamma agonist treatment decreased the expression of pyruvate dehydrogenase kinase 4, which represses oxidative glucose metabolism, and also decreased the expression of genes involved in fatty acid transport and oxidation. These changes suggest a molecular basis for PPAR gamma-mediated increases in glucose utilization in muscle. In liver, PPAR gamma activation coordinately decreased the expression of genes involved in gluconeogenesis. We conclude from these studies that the antidiabetic actions of PPAR gamma agonists are probably the consequence of 1) their effects on FFA levels, and 2), their coordinate effects on gene expression in multiple insulin-sensitive tissues.  相似文献   
29.
Schizophrenia (SZ) and bipolar disorder (BD) share some similarities in terms of genetic-risk genes and abnormalities of gray-matter structure in the brain, but white matter (WM) abnormalities have not been studied in depth. We undertook a comparative multimodal meta-analysis to identify common and disorder-specific abnormalities in WM structure between SZ and BD. Anisotropic effect size-signed differential mapping software was used to conduct a comparative meta-analysis of 68 diffusion tensor imaging (DTI) and 34 voxel-based morphometry (VBM) studies comparing fractional anisotropy (FA) and white matter volume (WMV), respectively, between patients with SZ (DTI: N = 1543; VBM: N = 1068) and BD (DTI: N = 983; VBM: N = 518) and healthy controls (HCs). The bilateral corpus callosum (extending to the anterior and superior corona radiata) showed shared decreased WMV and FA in SZ and BD. Compared with BD patients, SZ patients showed remarkable disorder-specific WM abnormalities: decreased FA and increased WMV in the left cingulum, and increased FA plus decreased WMV in the right anterior limb of the internal capsule. SZ patients showed more extensive alterations in WM than BD cases, which may be the pathophysiological basis for the clinical continuity of both disorders. The disorder-specific regions in the left cingulum and right anterior limb of the internal capsule provided novel insights into both disorders. Our study adds value to further understanding of the pathophysiology, classification, and differential diagnosis of SZ and BD.  相似文献   
30.
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