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   255篇
  免费   19篇
  国内免费   1篇
耳鼻咽喉   2篇
儿科学   11篇
妇产科学   8篇
基础医学   26篇
口腔科学   9篇
临床医学   27篇
内科学   63篇
皮肤病学   14篇
神经病学   16篇
特种医学   13篇
外科学   21篇
综合类   7篇
预防医学   24篇
眼科学   2篇
药学   21篇
肿瘤学   11篇
  2024年   1篇
  2023年   9篇
  2022年   17篇
  2021年   33篇
  2020年   12篇
  2019年   17篇
  2018年   17篇
  2017年   12篇
  2016年   11篇
  2015年   14篇
  2014年   7篇
  2013年   14篇
  2012年   14篇
  2011年   28篇
  2010年   8篇
  2009年   13篇
  2008年   5篇
  2007年   3篇
  2006年   16篇
  2005年   5篇
  2004年   4篇
  2003年   1篇
  2000年   5篇
  1999年   1篇
  1998年   1篇
  1996年   1篇
  1994年   1篇
  1992年   1篇
  1989年   1篇
  1987年   2篇
  1968年   1篇
排序方式: 共有275条查询结果,搜索用时 15 毫秒
21.
22.
23.
AimTo evaluate the efficacy of an ethanolic Salvadora persica extract in removing the smear layer following a root canal procedure.MethodsSixty extracted, single-rooted human teeth were cleaned, shaped, and divided into four groups. Experimental groups 1 (n = 20) and 2 (n = 20) were irrigated with 1 mg/ml and 5 mg/ml of S. persica, respectively. The positive controls (n = 10) were irrigated with 17% ethylenediaminetetraacetic acid (EDTA), while the negative controls (n = 10) were irrigated with saline. Approximately 5 ml of the irrigating solution was delivered into the root canals for 5 min, and the final rinse was performed with 5 ml of 1% sodium hypochlorite. Scanning electron microscopy was used to evaluate the endodontic smear layer removal at the coronal, middle, and apical thirds of the specimens.ResultsA significant difference in smear layer removal between groups 1 and 2 at the coronal and middle thirds of the canal was observed, and no significant difference was seen between group 2 and the positive control at the coronal third. At the apical third, both concentrations of S. persica had similar effects and were less effective than the positive control in removing the smear layer.ConclusionThe 5 mg/ml S. persica solution was significantly more effective than the 1 mg/ml solution. In addition, the 5 mg/ml S. persica solution was as effective as 17% EDTA in removing the smear layer from the coronal third of the canal wall.  相似文献   
24.

Background

Numerous tools to assess activity of rheumatoid arthritis (RA) are available to use. For any marker to be a more appropriate indicator of disease activity, it should be more authentic to the patho-physiologic basis of the disease.

Aim of the work

To determine the performance of serum adenosine deaminase (sADA) in measuring disease activity in RA.

Patients and Methods

100 RA patients and 100 matched controls were included in the study. The disease activity score (DAS28) with erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were assessed. sADA level was determined by spectrophotometry. The sADA level was integrated in the DAS28 formulae and the corresponding values were determined.

Results

The mean age of the RA patients was 61.8?±?9.7?years, 68% were females and they had a disease duration of 12.5?±?3.7?years. The mean DAS28-ESR was 4.2?±?1.3 and DAS28-CRP 3.5?±?1.1. The mean sADA was significantly higher in the patients (33.6?±?11.6?U/L) compared to the control (25.1?±?9.9?U/L) (p?<?0.001). The sADA level and DAS28-sADA did not differ according to the gender, methotrexate use, rheumatoid factor or anti-citrullinated protein autoantibodies positivity. The mean DAS28-sADA significantly increased in higher activity categories (p?<?0.001). sADA significantly correlated with the disease activity parameters. DAS28-sADA significantly correlated with DAS28-ESR (r?=?0.57, p?<?0.001) and DAS28-CRP (r?=?0.604, p?<?0.001). DAS28-sADA showed a sensitivity of 0.9 and specificity 0.69 for detection of disease activity measured with DAS28-ESR and was 0.88 and 0.65 when measured with DAS28-CRP.

Conclusion

Integration of sADA in the DAS28 index can be a useful marker that reflects RA activity.  相似文献   
25.

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   
26.
A new triterpenoidal saponin identified as 3-O-[β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 4)-β-d-xylopyranosyl]-2β,3β,16α-trihydroxyolean-12-en-23,28-dioic acid-28-O-α-l-rhamnopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 2)-α-l-arabinopyranoside 1 together with a new oleanane triterpene identified as 2β,3β,13α,22α-tetrahydroxy olean-23,28-dioic acid 2 and 6 known compounds (3–8) have been isolated from Gladiolus segetum Ker-Gawl corms. The structural elucidation of the isolated compounds was confirmed using different chemical and spectroscopic methods, including 1D and 2D NMR experiments as well as HR-ESI-MS. Moreover, the in vitro cytotoxic activity of the fractions and that of the isolated compounds 1–8 were investigated against five human cancer cell lines (PC-3, A-549, HePG-2, MCF-7 and HCT-116) using doxorubicin as a reference drug. The results showed that the saponin fraction exhibited potent in vitro cytotoxic activity against the five human cancer cell lines, whereas the maximum activity was exhibited against the PC-3 and A-549 cell lines with the IC50 values of 1.13 and 1.98 μg mL−1, respectively. In addition, compound 1 exhibited potent activity against A-549 and PC-3 with the IC50 values of 2.41 μg mL−1 and 3.45 μg mL−1, respectively. Interestingly, compound 2 showed the maximum activity against PC-3 with an IC50 of 2.01 μg mL−1. These biological results were in harmony with that of the molecular modeling study, which showed that the cytotoxic activity of compound 2 might occur through the inhibition of the HER-2 enzyme.

A new triterpenoidal saponin 1, a new oleanane triterpene 2, and 6 known compounds (3–8) have been isolated from Gladiolus segetum Ker-Gawl corms.  相似文献   
27.
Methotrexate[MTX] is commonly employed as the initial DMARD used for treatment of Rheumatoid arthritis[RA]. We aimed to contribute to the safety profile of MTX by assessing its cumulative effect on renal filtration. Fifty two RA adult females with normal base-line serum creatinine and GFR at the initial diagnosis of the disease were included. Group-1[G1] included 30 patients[mean age 40.4 ± 4.4 years] on MTX and NSAIDS, while 22 RA patients[mean age 38.5 ± 8.2 years] who received NSAIDs only served as the control group[G2]. Renal function was assessed by GFR-measurement using Technetium diethylenetriamine-pentaacetic acid[Tc-99 m-DTPA] at the point of the study time corresponding to disease duration. 21/30[70%] in G1 showed reduced GFR compared to 6/22[27.3%] in G2[P0.007] with 3.3 ± 0.5% annual reduction of GFR. Reduced GFR in G1 showed significant negative correlation with age[r = ?0.396, P = 0.005], MTX-cumulative dose[r = ?0.263, P = 0.049], MTX-intake duration[r = ?0.293, P = 0.031] and NSAID-intake duration[r = ?0.344, P = 0.014]. Low dose MTX has a slow cumulative effect on renal filtration manifested by GFR reduction over time that could be monitored by Tc-99 m DTPA.  相似文献   
28.
29.
AIM: To investigate the relationship between low molecular polypeptide-7 (LMP-7) gene polymorphism and response to interferon (IFN) therapy in chronic hepatitis C virus (HCV) patients.METHODS: LMP-7 polymorphism at codon 49 with nucleotide substitution from A to C was amplified in 104 chronic HCV patients of genotype 4. The amplicons were digested with restriction endonuclease BsmI and the produced restriction fragment length polymorphism was analyzed. Patients received IFN + regional blood volume therapy for 48 wk and the frequency of this single nucleotide polymorphism (SNP) was statistically correlated with treatment response. The exclusion criteria for these patients were stated by the national health program for treating viral hepatitis. Main exclusion criteria included co-infection with hepatitis B virus or schistosomiasis, thyroid dysfunction, uncontrolled diabetes mellitus, history of long term drug or alcohol intake and autoimmune hepatitis. Multivariate analyses were done to correlate LMP-7 SNP plus several factors such as age, gender, weight, serum alpha-fetoprotein (AFP) and alanine aminotransferase levels, liver activity, fibrosis score and viral load with response to therapy.RESULTS: The data presented in this study clearly demonstrated statistically significant differences between sustained virological response (SVR) (defined as the absence of HCV RNA levels in the patient’s sera at least 6 mo after discontinuation of treatment) and non-response (NR) (where HCV RNA levels in the patient’s sera never become undetectable for 6 mo during or after treatment). Variables were described as odds ratio with 95%CI. The data were considered significant if P values were ≤ 0.05; highly significant if P < 0.01 and very highly significant if P < 0.001. Current data showed that 91.7% of patients carrying LMP-7 C/C allele were associated with SVR, while the other two genotypes C/A and A/A were associated with NR patients, 83.3% and 64.3% respectively, showing that genotype CC was strongly associated with response to interferon (95%CI: 12.0719-134.6572, P = 0.0001). The majority of parameters recorded in SVR and NR patients included higher values of mean age (P = 0.004), alanine aminotransferase (P = 0.001), AFP (P = 0.001), body weight (P = 0.025), viral load (P = 0.025), higher fibrosis and histological activity index indices among NR vs SVR patients. Also, the multivariate statistical analysis of the different factors of fibrosis score, liver activity grade, genotypes and alleles of LMP-7 gene polymorphism in responders and NRs of HCV patients in this study showed that HCV patients with A allele had a very highly significant association with the NRs, high fibrosis and higher liver activity, while the C allele had a very highly significant association with the responders, low fibrosis and lower liver activity (95%CI: 3.5800-13.2519, P = 0.0001).CONCLUSION: LMP-7 SNP is a candidate gene that should be considered when designing a mathematical model for predicting response to therapy and disease progression in HCV patients.  相似文献   
30.
IntroductionEgypt has established different types of surveillance systems to monitor influenza activities, early detect outbreaks, and tailor efficient prevention and control strategies. This is the first study to describe epidemiology and outcome of influenza‐associated infections among hospitalized patients using the National Electronic Disease Surveillance System (NEDSS) data, 2016‐2019.MethodsData reported from 284 hospitals all over Egypt were extracted from the NEDSS. Data of hospitalized patients with Acute Respiratory Infections (ARI), 2016‐2019, were included in the analysis. Laboratory testing for influenza by RT‐PCR according to US CDC testing protocol was used to confirm influenza type and subtype.ResultsOverall 46 417 patients hospitalized with ARI were identified, their mean age was 30.9 ± 26 and 52.9% were males. Among 41 512 (89.4%) laboratory‐tested patients, 7167 (17.3%) were positive for one or more types of influenza viruses. Influenza viruses circulated in all ages and throughout the year, with higher rates in winter, late childhood, and middle ages. Mortality from influenza was significantly higher than other causes of ARIs (5.0% vs 3.8%, P < .001), and it was associated with older ages, December‐May, delay in hospital admission, residence in urban and frontier governorates and infection with A/H1N1 virus. The distribution of influenza subtype by time shows alternate pattern between A/H1N1 and H3N2, each subtype peaks every other year with a high peak of A/H1N1 in 2016.ConclusionsThe national Egyptian surveillance succeeded to describe the epidemiology of hospitalized patients with ARIs and influenza in Egypt over time. Surveillance with strain‐specific laboratory testing and annual assessment of associated severity might be useful to guide influenza prevention and control strategies including vaccination and case management.  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