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   637篇
  免费   62篇
  国内免费   8篇
耳鼻咽喉   4篇
儿科学   14篇
妇产科学   11篇
基础医学   79篇
口腔科学   35篇
临床医学   70篇
内科学   147篇
皮肤病学   68篇
神经病学   42篇
特种医学   18篇
外国民族医学   1篇
外科学   36篇
综合类   5篇
预防医学   30篇
眼科学   9篇
药学   93篇
中国医学   4篇
肿瘤学   41篇
  2024年   2篇
  2023年   20篇
  2022年   53篇
  2021年   76篇
  2020年   50篇
  2019年   66篇
  2018年   71篇
  2017年   51篇
  2016年   36篇
  2015年   40篇
  2014年   30篇
  2013年   39篇
  2012年   50篇
  2011年   40篇
  2010年   15篇
  2009年   8篇
  2008年   7篇
  2007年   13篇
  2006年   12篇
  2005年   5篇
  2004年   6篇
  2003年   7篇
  2002年   3篇
  2001年   1篇
  2000年   1篇
  1993年   1篇
  1988年   1篇
  1980年   1篇
  1979年   2篇
排序方式: 共有707条查询结果,搜索用时 15 毫秒
1.

Background

Diabetic foot ulceration (DFU) is a serious diabetic complication that can progress to amputation and since SIRT1 regulates glucose metabolism, inflammation, and oxidative stress which are the major contributors in diabetic complications, So we aimed to discuss its role as an epigenetic biomarker in DFU and highlight its link to oxidative stress and inflammatory cytokines.

Method

60 DM patients were enrolled in the study, 30 without DFU and 30 with DFU in addition to 15 healthy subjects (control group). SIRT1 mRNA relative gene expression was assessed. Catalase activity, advanced glycation end products (AGEs), tumor necrosis factor alpha (TNFα), interleukin 6 (IL-6) and High mobility group box1 (HMGB1) levels were measured. DNA fragmentation was also performed.

Result

SIRT1 expression and catalase activity were significantly decreased in diabetic patients compared to control group with the lowest levels in DFU patients, TNFα, IL-6, HMGB 1 and AGEs levels were significantly higher in the diabetic patients compared to control group with the highest levels in DFU patients. DNA fragmentation was more profound in DFU patients.

Conclusion

The study revealed that SIRT1 mRNA expression can be considered as a novel biomarker in DFU being a major player involved in its pathogenesis.  相似文献   
2.
Diabetic nephropathy is a clinical syndrome characterized by albuminuria, hypertension and progressive renal insufficiency. The aim of this study was to investigate the effect of strawberry (Fragaria × ananassa) leaf extract on diabetic nephropathy in rats. Streptozotocin (STZ) diabetic rats were orally treated with three doses (50, 100 and 200 mg/kg) of strawberry leaf extract for 30 days. Nephropathy biomarkers in plasma and kidney were examined at the end of the experiment. The three doses of strawberry leaf extract significantly decreased the levels of blood glucose, urea nitrogen, plasma creatinine, kidney injury molecule (Kim)‐1, renal malondialdehyde (MDA), tumour necrosis factor alpha (TNF‐α), interleukin (IL)‐ 6 and caspase‐3 in diabetic rats. Meanwhile, the levels of plasma insulin, albumin, uric acid, renal catalase (CAT), superoxide dismutase (SOD) and vascular endothelial growth factor A (VEGF‐A) were significantly elevated in diabetic rats treated with strawberry leaf extract. These results indicate the role of strawberry leaves extract as anti‐diabetic, antioxidant, anti‐inflammatory and anti‐apoptosis in diabetic nephropathy.  相似文献   
3.

Background

Health care is increasingly provided in general practice. To meet this demand, the English Department of Health recommends that 50% of all medical students should train for general practice after qualification. Currently 19% of medical students express general practice as their first career choice. Undergraduate exposure to general practice positively influences future career choice. Appropriate undergraduate exposure to general practice is therefore highly relevant to workforce planning

Aim

This study seeks to quantify current exposure of medical students to general practice and compare it with past provision and also with postgraduate provision.

Design and setting

A cross-sectional questionnaire in the UK.

Method

A questionnaire regarding provision of undergraduate teaching was sent to the general practice teaching leads in all UK medical schools. Information was gathered on the amount of undergraduate teaching, how this was supported financially, and whether there was an integrated department of general practice. The data were then compared with results from previous studies of teaching provision. The provision of postgraduate teaching in general practice was also examined.

Results

General practice teaching for medical students increased from <1.0% of clinical teaching in 1968 to 13.0% by 2008; since then, the percentage has plateaued. The total amount of general practice teaching per student has fallen by 2 weeks since 2002. Medical schools providing financial data delivered 14.6% of the clinical curriculum and received 7.1% of clinical teaching funding. The number of departments of general practice has halved since 2002. Provision of postgraduate teaching has tripled since 2000.

Conclusion

Current levels of undergraduate teaching in general practice are too low to fulfil future workforce requirements and may be falling. Financial support for current teaching is disproportionately low and the mechanism counterproductive. Central intervention may be required to solve this.  相似文献   
4.
Self-rated health reflects a person’s integrated perception of health, including its biological, psychological, and social dimensions. It is a predictor of morbidity and mortality. To assess the current status of self-rated health and associated factors in the Kingdom of Saudi Arabia, we analyzed data from the Saudi Health Interview Survey. We conducted a large national survey of adults aged 15 years or older. A total of 10,735 participants completed a standardized health questionnaire. Respondents rated their health with a five-point scale. Data on socio-demographic characteristics, chronic diseases, health-related habits and behaviors, and anthropometric measurements were collected. Associated factors of self-rated health were analyzed using a backward elimination multivariate logistic regression model. More than 77 % of respondents rated their health as excellent/very good. Female sex [odds ratio (OR) 1.52, 95 % confidence interval (CI) 1.24–1.88], decades of age (OR 1.35, 95 % CI 1.25–1.46), diagnosed diabetes mellitus (OR 1.54, 95 % CI 1.22–1.93), diagnosed hypercholesterolemia (OR 1.37, 95 % CI 1.06–1.79), diagnosed hypertension (OR 1.55, 95 % CI 1.22–1.96), number of other diagnosed chronic diseases (OR 1.69, 95 % CI 1.41–2.03), limited vigorous activity (OR 3.59, 95 % CI 2.84–4.53), need for special equipment (OR 2.62, 95 % CI 1.96–3.51), and more than 3 h of daily television/computer screen time (OR 1.59, 95 % CI1.11–2.29) were positively associated with poor/fair health. Smoking, obesity, and physical inactivity were not associated with self-reported health. We found that preventable risk factors are not associated with Saudis’ self-rated health. This optimistic perception of health poses a challenge for preventive interventions in the Kingdom and calls for campaigns to educate the public about the harm of unhealthy behaviors.  相似文献   
5.
Considerably, variability in the clinical response to inotropic agents is observed and could be explained partially by the genetic variants, such as single-nucleotide polymorphism (SNP) in genes encoding for enzymes implicated in catecholamines synthesis, metabolism, storage and release or in the signaling pathway. This review highlights the potential effect of pharmacogenetics studies in hemodynamic response and identified 11 SNPs that could be relevant to explain the high variability drug response for a same dose. Cardiovascular instability, such as hypotension, is one of the premature birth complications. The pharmacogenetics studies evaluating these SNP may be useful to better understand the clinical outcome, particularly in this population.  相似文献   
6.
A new species Kudoa azevedoi sp. n. (Myxozoa, Multivalvulida) is described in Trachurus trachurus Linnaeus, 1758 (Carangidae) from fishing harbors in Tunisian coasts using spore morphology and SSU rDNA sequence data. The parasite occurs only in ovaries within oocytes of mature and immature specimens. Spores are quadrate in shape in apical view with rounded edges, having four shell valves and four symmetrical polar capsules. They are of small sizes and measure 3.5?±?0.41 (3–4.2)?×?4.5?±?0.44 (4–5.2) length by width. The polar capsules are pyriform in shape measuring 1.5?±?0.22 (1.5–2)?×?0.75?±?0.14 (0.5–1)?μm. Infected oocytes are hypertrophied, whitish colored, and filled with mature spores. Plasmodia are tubular and ramified from the inner membrane toward the center of the oocyte. Phylogenetic analysis based on small subunit ribosomal DNA sequences shows the highest similarity (96 %) with the ovary parasite Kudoa ovivora. Some morphological details and spore dimensions support the creation of a new species in the genus Kudoa. Mean prevalence among examined females is of about 55.5 %. It varies between localities and length of fish. The present myxosporea is the second Kudoa species reported in fish ovaries.  相似文献   
7.
IntroductionCurcumin therapeutic applications are constrained by its prominent metabolic instability as well as inadequate absorption and bioavailability. The current study was designed to enhance the curcumin bioavailability by exploiting nanoparticles.Material and methodsEleven groups of mice were divided into: normal and nanoparticle control groups, a hepatocellular carcinoma (HCC) group induced by diethylnitrosamine (DEN), 2 groups treated with DEN plus a high dose/low dose of free curcumin, 2 groups treated with a high dose/low dose of free curcumin, 2 groups treated with DEN plus a high dose/low dose of nanoparticulate curcumin, and 2 groups treated with a high dose/low dose of nanoparticulate curcumin.ResultsDEN administration significantly increased liver enzymes, vascular endothelial growth factor, tumor necrosis factor-α, α-fetoprotein, malondialdehyde, and nucelar factor-κB. Also, it decreased serum albumin and tissue antioxidant activities and caused severe histological changes in hepatic tissue. Oral treatment of DEN-injected mice with either a high dose of free curcumin or the tested doses of nanoparticulate curcumin resulted in a significant improvement of all the tested parameters.ConclusionsAlthough the two tested doses of nanoparticulate curcumin were much lower than free curcumin, both doses were effective in preventing HCC development while the low dose of free curcumin was hardly effective. Hence, we conclude that nanoparticles enhance the bioavailability of curcumin.  相似文献   
8.
We herein have developed a mild approach for the fabrication of glauconite clay (G)-modified chitosan (CS) nanocomposites by the combination of a simple blending and crosslinking method. The chitosan was modified with ethylenediaminetetraacetic acid (EDTA), glutaraldehyde (GL), sodium dodecyl sulfate (SDS), and cetyltrimethyl ammonium bromide (CTAB). The as-prepared composites were identified using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), nitrogen physical adsorption (BET), atomic absorption spectrophotometry (AA), and thermal gravimetric analysis (TGA). The adsorption activities of the as-prepared materials were assessed for the removal of fluoride ions from aqueous media using a batch technique. Raw glauconite (G), GL-CS/G, SDS-CS/G, EDTA-GL-CS/G, and CTAB-CS/G adsorbents displayed maximum adsorption capacity values of 1.15, 4.31, 4.55, 6.90, and 9.03 mg g−1, respectively. The adsorption results were well described by employing the pseudo-second-order kinetic and Langmuir isotherm models. The estimated thermodynamic constants indicated that the F ion adsorption was a spontaneous, physisorption process. Furthermore, the modified chitosan adsorbents are good candidates for the adsorptive elimination of F ions from aqueous solutions, according to their reusability, high stability, good adsorption capacity, and applicability for actual field water samples.

We herein have developed a mild approach for the fabrication of glauconite clay (G)-modified chitosan (CS) nanocomposites by the combination of a simple blending and crosslinking method.  相似文献   
9.

Background

Primary cutaneous amyloidosis (PCA) comprises three main forms: macular, lichen, and nodular amyloidosis. The current available treatments are quite disappointing.

Objectives

Assess and compare the clinical and histological changes induced by different modes of Fractional CO2 laser in treatment of PCA.

Patients and Methods

Twenty five patients with PCA (16 macular and 9 lichen amyloidosis) were treated by fractional CO2 using; superficial ablation (area A ) and deep rejuvenation (area B ). Each patient received 4 sessions with 4 weeks intervals. Skin biopsies were obtained from all patients at baseline and one month after the last session. Patients were assessed clinically and histologically (Congo red staining, polarized light). Patients were followed‐up for 3 months after treatment.

Results

Both modes yielded significant reduction of pigmentation, thickness, itching, and amyloid deposits (P‐value < 0.001). However, the percentage of reduction of pigmentation was significantly higher in area A (P‐value = 0.003). Pain was significantly higher in area B. Significant reduction in dermal amyloid deposits denotes their trans‐epidermal elimination induced by fractional photothermolysis.

Conclusion

Both superficial and deep modes of fractional CO2 laser showed comparable efficacy in treatment of PCA. Superficial mode being better tolerated by patients, is recommended as a valid therapeutic option. Lasers Surg. Med. 47:388–395, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   
10.

Background

There is risk of premature atherosclerosis in juvenile idiopathic arthritis (JIA) patients which predisposes to cardiovascular disease (CVD) in adulthood. This can be assessed by flow mediated dilatation (FMD) and carotid intima media thickness (IMT) of the arterial wall and by soluble vascular cell adhesion molecule (sVCAM-1).

Aim of the work

To assess endothelial dysfunction in JIA children and to correlate sVCAM with FMD of brachial artery and carotid IMT.

Patients and methods

The study was conducted on 55 JIA patients. The following was assessed: body mass index (BMI), blood pressure, juvenile arthritis disease activity score (JADAS27). Childhood Health Assessment Questionnaire (C-HAQ), physical activity questionnaire (PAQ), fatigue assessment using The Pediatric Quality of Life (PedsQL) inventory, full blood count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), serum creatinine and lipid profile, sVCAM-1, FMD and IMT.

Results

The patients’ age was 10.9?±?3.9?years and were 28 (50.9%) females. JADAS-27 and CRP was higher in systemic JIA, but fatigue scores were significantly lower. CHAQ was significantly lower in patients with polyarticular disease. Patients with high disease activity had significantly younger age of onset, lower BMI, shorter disease duration, lower fatigue scale and physical activity scores and higher CHAQ. sVCAM-1 significantly correlated with CHAQ, low-density lipoprotein, CRP and ESR while FMD significantly correlated with PedsQL and PAQ.

Conclusion

JIA patients had impaired endothelial function and increased cIMT with increased sVCAM-1, impaired lipid profile, decreased physical activity and increased fatigue with a potentially higher cardiovascular risk in this pediatric population.  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