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   2296篇
  免费   199篇
  国内免费   31篇
耳鼻咽喉   32篇
儿科学   48篇
妇产科学   49篇
基础医学   311篇
口腔科学   63篇
临床医学   232篇
内科学   477篇
皮肤病学   72篇
神经病学   103篇
特种医学   88篇
外国民族医学   2篇
外科学   499篇
综合类   39篇
一般理论   1篇
预防医学   193篇
眼科学   30篇
药学   128篇
中国医学   8篇
肿瘤学   151篇
  2023年   24篇
  2022年   55篇
  2021年   73篇
  2020年   50篇
  2019年   81篇
  2018年   121篇
  2017年   71篇
  2016年   78篇
  2015年   75篇
  2014年   110篇
  2013年   120篇
  2012年   159篇
  2011年   168篇
  2010年   116篇
  2009年   88篇
  2008年   116篇
  2007年   129篇
  2006年   113篇
  2005年   123篇
  2004年   84篇
  2003年   87篇
  2002年   78篇
  2001年   59篇
  2000年   59篇
  1999年   38篇
  1998年   17篇
  1997年   15篇
  1996年   16篇
  1995年   10篇
  1994年   10篇
  1993年   8篇
  1992年   24篇
  1991年   12篇
  1990年   12篇
  1989年   16篇
  1988年   17篇
  1987年   9篇
  1986年   11篇
  1985年   9篇
  1984年   6篇
  1983年   5篇
  1981年   3篇
  1979年   9篇
  1978年   5篇
  1977年   3篇
  1976年   6篇
  1974年   5篇
  1973年   3篇
  1972年   3篇
  1969年   4篇
排序方式: 共有2526条查询结果,搜索用时 0 毫秒
31.
Obesity is often associated with chronic inflammatory state which contributes to the development of insulin resistance (IR) and type 2 diabetes mellitus (T2DM). This study investigated the effects of single and combined administration of atorvastatin (ATOR, lipid‐lowering drug) and losartan (LOS, angiotensin receptor antagonist) on metabolic disorders and inflammatory status that are implicated in the development of T2DM with the use of pioglitazone (PIO) as a standard antidiabetic drug. T2DM was induced in male rats by high‐fat diet (HFD) feeding for 16 weeks. Oral administrations of ATOR (10 mg/kg), LOS (20 mg/kg), PIO (3 mg/kg), their binary combinations, or vehicle were started in the last 4 weeks. Fasting serum glucose, oral glucose tolerance, fasting serum insulin, IR, serum lipid profile, serum TNF‐α and body composition index were determined. Results showed that all drugs and their combinations had positive impact effect on all measured parameters, and better results were achieved from binary drug combinations than administration of each drug alone. Combination of PIO with either ATOR or LOS provided better improvements on T2DM‐associated metabolic abnormalities and inflammatory status with respect to each drug alone. However, the most pronounced effects of drugs and their combinations regarding the above parameters were attributed to LOS + PIO combination. In conclusion, this study indicates that combination of ATOR + PIO and, in particular, LOS + PIO can be used as promising effective therapies in the management of HFD‐induced T2DM. This concept may be attributed to the combined effects of the respective monotherapies to improve lipid profile, insulin sensitivity, and TNF‐α level.  相似文献   
32.
33.
In a previous study, the musculoskeletal affections among kidney recipients (KR) were reported, with 63 KR suffering from joint affections. We sought to determine the prevalence of osteonecrosis (ON) among those KR with joint affections, its distribution among the affected joints, and possible risk predictors. KR were subjected to biochemical, haematological, and hepatitis serology estimations. Radiographic and magnetic resonance imaging were performed. Relevant data were retrieved from Patient Information System. Fourteen KR were suffering from ON, with an incidence of 22.2% in KR with joint affections and 12.0% in the target population of KR. The femoral head was affected in 57.1% and the femoral condyles in 28.6%. Hypocalcaemia was observed in KR with ON. Whether hypocalcaemia is a causative or associative of ON yet remains to be decided in forthcoming studies.  相似文献   
34.
Noroviruses and sapoviruses are members of the family Caliciviridae and emerging enteric pathogens of humans and animals. Since their discovery and characterization in swine, relatively few strains have been described in detail. In order to investigate their genetic diversity, a total of 266 fecal samples collected in the province of Quebec, Canada, between 2005 and 2007 were screened for the presence of caliciviruses by RT-PCR using broadly reactive primers. Genetically heterogeneous caliciviruses were detected on the majority of farms. Typical noroviruses related to known swine genotypes were present on 20% of the farms. Sapoviruses were detected on 75% of the farms and were the most heterogeneous group. Further characterization of selected strains in their 3′ end parts was carried out for their classification and unveiled possibly new clusters of sapoviruses. No human-like noroviruses or sapoviruses were detected in the present study. GenBank accession numbers of all sequences described in this study are indicated in the figure legends.  相似文献   
35.
36.
BACKGROUND: Colonoscopy preparation regimens are often poorly tolerated because they require use of large-volume bowel preparation solution and diet restrictions for adequate cleansing. This study evaluated the efficacy and tolerability of a split-dose polyethylene glycol-electrolyte solution plus bisacodyl and a regular diet. METHODS: A total of 187 patients (104 men, 83 women; age range 18-91 years) were randomly assigned to receive either 3 L of polyethylene glycol-electrolyte solution (n = 96; Group A) with a liquid diet on the day before colonoscopy, or 2 L of polyethylene glycol-electrolyte solution, one tablet of bisacodyl, and a minimally restricted diet on the day before colonoscopy, and then 1 L of the same solution on the day of colonoscopy (n = 91; Group B). Acceptability, adverse events, and willingness to retake the preparation were assessed by questionnaire. The quality of the preparation was graded by an endoscopist, blinded to the type of preparation, by using a previously described scale (excellent to poor). RESULTS: There were 96 patients in Group A and 91 in Group B. Colon cleansing was significantly better in Group B with regard to the overall quality of the preparation (p lt; 0.05). Compliance was significantly higher in Group B as evidenced by the lower number of patients who discontinued the preparation (4 vs. 15; p = 0.02) because of side effects such as nausea or vomiting. The degree of discomfort, adverse events, and willingness to retake the preparation were not significantly different between the groups. CONCLUSIONS: Colonic preparation with split-dose polyethylene glycol-electrolyte provided better quality colon cleansing and higher compliance, with less dietary restrictions, than preparation with whole-dose polyethylene glycol-electrolyte.  相似文献   
37.

Purpose

Results from a 6-month double-masked and a 6-month open-label study (SANSIKA) established the efficacy and safety of once-daily 0.1% cyclosporin A cationic emulsion (CsA CE) in severe keratitis due to dry eye disease (DED). This article presents results from the Post-SANSIKA study, a 24-month extension of SANSIKA assessing the sustained efficacy of CsA CE after treatment discontinuation.

Methods

Time to relapse (corneal fluorescein staining [CFS] score ≥4 [modified Oxford scale]) was assessed after treatment discontinuation in patients from the SANSIKA study who had CFS improvement from a score of 4 to ≤2 after 6 or 12 months of treatment with CsA CE.

Findings

Of 62 patients who achieved a CFS score ≤2 at the end of the SANSIKA study, 38 did not relapse and 24 (39%) relapsed during the 24-month period after CsA CE discontinuation; the latter (relapse) group comprised 35% of patients initially treated with CsA CE for 12 months in SANSIKA versus 47% of those treated for 6 months only. Patients spent the most time during the extension study at CFS scores of 1 or 2 (median duration of 8.5 weeks and 14.7 weeks per year, respectively), indicating marked improvement, and less time at scores of 3, 4, or 5 (median time, 2.0 weeks, 0 weeks, and 0 weeks per year). Of 23 patients eligible for safety analysis (ie, patients who received the study treatment at least once), 12 (52.2%) reported a total of 26 ocular adverse events (AEs). Among these, 5 ocular AEs, reported in 5 patients (21.7%), were considered related to study treatment: 3 events of mild instillation site pain in 3 patients (13.0%) and eye discharge and foreign body sensation, each reported in 1 patient (4.3%). Only 1 systemic AE (nasal congestion), reported in 1 patient (4.3%), was considered related to study treatment. None of the AEs led to treatment discontinuation.

Implications

The majority of patients who discontinued CsA CE after experiencing DED improvement in the SANSIKA study did not experience a relapse in this 24-month follow-up study; these patients spent the most time at CFS scores consistent with marked improvement. CsA CE had a favorable safety/tolerability profile over 2 years. Treatment for up to 12 months with CsA CE provides sustained improvements in patients with severe keratitis due to DED. EudraCT registration no. 2012-002066-12.  相似文献   
38.
In this study, we present a successful simple method for printing and finishing of polyester and cotton fabrics using gold and silver nanoparticles (Au-NPs and Ag-NPs, respectively) as stable, fast colorants and functional components. The surface plasmon resonance (SPR) bands of the colloidal gold and silver NPs were observed at λmax 520 nm and 450 nm, respectively, indicating the presence of spherical Au-NPs and Ag-NPs, which was further confirmed by TEM analysis. The printed samples were subjected to SEM, XRD and EDX analyses. The SEM images and EDX spectra unequivocally confirmed the existence of embedded NPs on the fabric surfaces. Both the cotton and polyester samples possessed excellent color fastness, as indicated from the color fastness test. The functional properties of the printed fabrics indicated that the incorporation of Au-NPs and Ag-NPs into the fabrics simultaneously imparted multifunctional properties such as stable brilliant colors, highly durable antimicrobial activity and very good UV-protection properties.

In this study, we present a successful simple method for printing and finishing of polyester and cotton fabrics using gold and silver nanoparticles (Au-NPs and Ag-NPs, respectively) as stable, fast colorants and functional components.  相似文献   
39.
AIMS: The aim of this study was to take a combination of animal and cell culture approaches to examine the individual responses of vascular cells to varying inflammatory factors in order to gain insights on the mechanism(s) by which poly(ADP-ribose) polymerase (PARP) inhibition promotes factors of plaque stability. METHODS AND RESULTS: Apolipoprotein (ApoE(-/-)) mice fed a high-fat diet were used as a model of atherosclerosis. Primary endothelial cells, smooth muscle cells (SMCs), and ex-vivo generated foam cells (FCs) were used in our in vitro studies. PARP inhibition significantly decreased the markers of oxidative stress and caspase-3 activation and increased smooth muscle actin within plaques from ApoE(-/-) mice fed a high-fat diet. PARP inhibition protected against apoptosis and/or necrosis in SMCs and endothelial cells in response to H(2)O(2) or tumour necrosis factor (TNF). Remarkably, PARP inhibition in FCs resulted in significant sensitization to 7-ketocholesterol (7-KC) by increasing cellular-toxic-free cholesterol, potentially through a down-regulation of acyl-CoA:cholesterol acyltransferase-1 (ACAT-1) expression. 7-KC induced necrosis exclusively in endothelial cells, which was, surprisingly, unaffected by PARP inhibition indicating that PARP inhibition does not prevent all forms of necrotic cell death. In SMCs, PARP-1 inhibition by gene deletion conferred protection against 7-KC or TNF, potentially by reducing caspase-3-like activation, preventing induction of c-Jun N-terminal protein kinase phosphorylation, and inducing extracellular signal-regulated kinase phosphorylation independently of PARP classical enzymatic activity. CONCLUSIONS: These data present PARP-1 as an important player in the death of cells constituting atherosclerotic plaques contributing to plaque dynamics. PARP inhibition may be a protective, a neutral, or a sensitizing factor. Additionally, PARP-1 may be a novel factor that can alter lipid metabolism. These novel functions of PARP not only challenge the current understanding of the role of the enzyme in cell death but also provide insights on the intricate contribution of PARP in cellular responses to predominant inflammatory factors within atherosclerotic plaques, presenting additional evidence for the viability of PARP inhibition as a therapeutic strategy for atherosclerosis.  相似文献   
40.
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