全文获取类型
收费全文 | 836篇 |
免费 | 53篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 28篇 |
妇产科学 | 26篇 |
基础医学 | 144篇 |
口腔科学 | 23篇 |
临床医学 | 99篇 |
内科学 | 199篇 |
皮肤病学 | 15篇 |
神经病学 | 64篇 |
特种医学 | 20篇 |
外科学 | 80篇 |
综合类 | 12篇 |
预防医学 | 50篇 |
眼科学 | 23篇 |
药学 | 71篇 |
中国医学 | 8篇 |
肿瘤学 | 31篇 |
出版年
2024年 | 2篇 |
2023年 | 14篇 |
2022年 | 38篇 |
2021年 | 76篇 |
2020年 | 34篇 |
2019年 | 42篇 |
2018年 | 53篇 |
2017年 | 46篇 |
2016年 | 41篇 |
2015年 | 32篇 |
2014年 | 40篇 |
2013年 | 49篇 |
2012年 | 77篇 |
2011年 | 68篇 |
2010年 | 39篇 |
2009年 | 43篇 |
2008年 | 35篇 |
2007年 | 44篇 |
2006年 | 33篇 |
2005年 | 19篇 |
2004年 | 19篇 |
2003年 | 14篇 |
2002年 | 10篇 |
2001年 | 8篇 |
2000年 | 11篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1990年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有896条查询结果,搜索用时 15 毫秒
61.
62.
N. Zendehdel F. Biramijamal N. Zendehdel H. Sarie M. Doughaiemoghaddam A. Pourshams S. Latifi‐Navid M. Dehghani 《Diseases of the esophagus》2010,23(7):603-607
Reflux esophagitis is a common complication of the gastroesophageal reflux disease. Glutathione s‐transferases (GSTs) have important role in the protection of cells from the products of oxidative stress. GSTP1*B allele has a correlation with susceptibility to several diseases. In this case‐control study, the role and frequency of GSTP1 polymorphism was evaluated in Iranian patients with erosive reflux esophagitis. Seventy patients with erosive reflux esophagitis and 75 normal individuals were enrolled in this study. The grade of esophagitis was determined via endoscopy. DNA was extracted from venous blood of each subject using the salting out method. GSTP1 genetic polymorphisms were detected using the polymerase chain reaction restriction fragment length polymorphism method. There was a significant difference in GSTP1 genotype frequency between patients and normal groups (P= 0.006). Also, in the patient group, the grade B of esophagitis was significantly associated with variant GSTP1 genotype (P= 0.028). The rate of throat pain symptom was higher in the no‐variant group (P < 0.036). The GSTP1*B allele frequency in Iranian normal groups is similar to Orientals. Reflux esophagitis are more commonly found in variant (*B/*B and *A/*B) GSTP1 genotypes. In addition, GSTP1 polymorphism is correlated with a higher grade of esophagitis. 相似文献
63.
64.
Nizal Sarrafzadegan Masoumeh Sadeghi Aliakbar Tavassoli Masood Mohseni Hasan Alikhasi Katayoun Rabiei Ahmad Bahonar 《Zeitschrift fur Gesundheitswissenschaften》2009,17(4):257-263
Aims To study the feasibility and impact of a comprehensive, integrated, community-based program directed towards reducing modifiable
risk factors for cardiovascular disease. In this study, we reported the differences in the impacts of IHHP on physical activity,
smoking and nutritional behaviors of a study population based on sex.
Subjects and methods Using multi-stage cluster sampling on people aged ≥19 years of both intervention and reference areas, 12,514 individuals in
2001, 5,891 in 2002, 4,793 in 2003 and 6,097 in 2004 as well as a sample of 3,011 participants from the intervention area
in 2005 were enrolled. Women made up 50.8 percent of participants, with similar proportions from 2001 to 2005 and comparable
distribution between intervention and reference areas. Eight distinct component interventional projects were designed separately
for both sexes to improve modifiable risk factors in the intervention area. The WHO STEPwise risk factor surveillance questionnaires
were used to conduct the annual cross-sectional surveys for behavioral changes. Estimates of intervention effect ratio were
conducted based on annual changes in the behavioral modifiable risk factors for both men and women.
Results Intervention activities positively affected the total and leisure-time physical activities in men, but not women. Dietary
choice of both sexes showed modest degrees of improvement. Smoking status of men improved in the study period (except 2004),
while the effect on women was not significant.
Conclusions Further interventions to improve physical activity in women should be regarded as a health priority in Iran. Sex differences
should be considered in implementing any health promotion activity.
Grant no. HQ/03/873531, WHO Department of Chronic Disease and Health Promotion 相似文献
65.
Electrical impedance tomography (EIT) is a non-invasive technique that aims to reconstruct images of internal electrical properties of a domain, based on electrical measurements on the periphery. Improvements in instrumentation and numerical modeling have led to three-dimensional (3D) imaging. The availability of 3D modeling and imaging raises the question of identifying the best possible excitation patterns that will yield to data, which can be used to produce the best image reconstruction of internal properties. In this work, we describe our 3D finite element model of EIT. Through singular value decomposition as well as examples of reconstructed images, we show that for a homogenous female breast model with four layers of electrodes, a driving pattern where each excitation plane is a sinusoidal pattern out-of-phase with its neighboring plane produces better qualitative images. However, in terms of quantitative imaging an excitation pattern where all electrode layers are in phase produces better results. 相似文献
66.
Comparison of the anti-influenza virus activity of RWJ-270201 with those of oseltamivir and zanamivir 总被引:5,自引:0,他引:5
下载免费PDF全文
![点击此处可从《Antimicrobial agents and chemotherapy》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Bantia S Parker CD Ananth SL Horn LL Andries K Chand P Kotian PL Dehghani A El-Kattan Y Lin T Hutchison TL Montgomery JA Kellog DL Babu YS 《Antimicrobial agents and chemotherapy》2001,45(4):1162-1167
We have recently reported an influenza virus neuraminidase inhibitor, RWJ-270201 (BCX-1812), a novel cyclopentane derivative discovered through structure-based drug design. In this paper, we compare the potency of three compounds, RWJ-270201, oseltamivir, and zanamivir, against neuraminidase enzymes from various subtypes of influenza. RWJ-270201 effectively inhibited all tested influenza A and influenza B neuraminidases in vitro, with 50% inhibitory concentrations of 0.09 to 1.4 nM for influenza A neuraminidases and 0.6 to 11 nM for influenza B neuraminidases. These values were comparable to or lower than those for oseltamivir carboxylate (GS4071) and zanamivir (GG167). RWJ-270201 demonstrated excellent selectivity (>10,000-fold) for influenza virus neuraminidase over mammalian, bacterial, or other viral neuraminidases. Oral administration of a dosage of 1 mg/kg of body weight/day of RWJ-270201 for 5 days (beginning 4 h preinfection) showed efficacy in the murine model of influenza virus infection as determined by lethality and weight loss protection. RWJ-270201 administered intranasally at 0.01 mg/kg/day in the murine influenza model demonstrated complete protection against lethality, whereas oseltamivir carboxylate and zanamivir at the same dose demonstrated only partial protection. In the delayed-treatment murine influenza model, oral administration of a 10-mg/kg/day dose of RWJ-270201 or oseltamivir (GS4104, a prodrug of GS4071) at 24 h postinfection showed significant protection against lethality (P < 0.001 versus control). However, when the treatment was delayed for 48 h, no significant protection was observed in either drug group. No drug-related toxicity was observed in mice receiving 100 mg/kg/day of RWJ-270201 for 5 days. These efficacy and safety profiles justify further consideration of RWJ-270201 for the treatment and prevention of human influenza. 相似文献
67.
Background
The aim of this study is to investigate the pattern of changes in serum albumin level after mini-gastric bypass (MGB) and its association with gender, age, and body mass index (BMI) of the patients.Methods
This cohort study was conducted on 196 morbidly obese patients undergoing MGB followed for 1 year. The data on BMI, serum albumin level, demographic, anthropometric, biochemical variables and comorbidities were gathered before and after (3, 6, and 12 months) surgery. The trend of changes in BMI and serum albumin of the patients was investigated by repeated measures tests using general linear model (GLM) and generalized estimating equations (GEE) approaches.Results
The mean age, baseline median BMI, and albumin of the patients were 41.34 ± 11.03 years, 44.54 kg/m2, and 4.00 g/dl, respectively. There was a chronologically significant trend of decline in BMI (P < 0.001). GEE demonstrated no chronologically significant trend in serum albumin (P = 0.278). The trend of changes in albumin was significantly associated only with age grouping and baseline serum albumin level (P = 0.017 and 0.001, respectively). This trend had fluctuations in patients older than 40 years with baseline serum albumin level of 3.50–3.90 g/dl. For patients with any age and baseline serum albumin level of 4.00–4.90 g/dl, this trend was stable in all periods of follow-up.Conclusion
MGB is an effective technique to lose weight. The trend of changes in serum albumin level was affected by its baseline levels and age.68.
Siavash Babajafari Masoumeh Akhlaghi Seyed Mohammad Mazloomi Mehdi Ayaz Ali Noorafshan Peyman Jafari Abdollah Hojhabrimanesh 《Burns : journal of the International Society for Burn Injuries》2018,44(1):140-149
Introduction
The objective was to determine the effect of isolated soy protein (ISP) and flaxseed oil (FO) on inflammatory and oxidative stress indices, acute phase proteins, and wound healing of burn patients.Methods
One hundred eighty-eight patients were assessed for eligibility in this randomized controlled trial. Of these, seventy-three eligible patients (total burn surface area 20–50%) were randomly assigned to 3 isocaloric groups, labeled as control (wheat flour + corn oil (CO)), ISP + FO, and ISP + CO, to receive these nutrients for 3 weeks. We used intention to treat analysis to overcome bias. Because of the large perturbation in water compartments, patients received nutrients from 4th to 25th day of admission. Serum high sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), superoxide dismutase (SOD), ferritin, albumin, and transferrin were measured. The wound area was evaluated by stereological test.Results
During the 3-week intervention, hs-CRP (?19.4 ± 5.6, ?11.7 ± 4.7 μg/ml) and ferritin (?83.8 ± 20.5, ?80.1 ± 19.6 ng/ml) levels changes significantly reduced compared to the control group (P < 0.05). MDA level (?0.05 ± 0.21 μmol/l) significantly decreased in group A (P < 0/05) but was not significant in groups B and control (P > 0.05). Albumin level (0.59 ± 0.14, 0.30 ± 0.12 g/dl) significantly increased in group A compared to the control group (P < 0.05), but no significant relationship was found between other groups (P > 0.05). Transferrin level (4.9 ± 3.6, 2.9 ± 5.1 g/dl) significantly increased in ISP groups compared to the control (P < 0.05). SOD improved in all groups with no significant difference between them (P > 0.05). The stereology examination showed significant improvement in wound healing in the ISP groups on days 22 and 25 compared to the control group.Conclusion
Nutritional supplements with ISP may attenuate post-burn oxidative stress and inflammation, leading to improved wound healing in burn patients. Flaxseed oil may not exert a beneficial effect over the ISP. 相似文献69.
70.
Tobias Pukrop Faramarz Dehghani Han‐Ning. Chuang Raphaela Lohaus Kathrin Bayanga Stephan Heermann Tommy Regen Denise Van Rossum Florian Klemm Matthias Schulz Laila Siam Anja Hoffmann Lorenz Trümper Christine Stadelmann Ingo Bechmann Uwe‐Karsten Hanisch Claudia Binder 《Glia》2010,58(12):1477-1489
Although there is increasing evidence that blood‐derived macrophages support tumor progression, it is still unclear whether specialized resident macrophages, such as brain microglia, also play a prominent role in metastasis formation. Here, we show that microglia enhance invasion and colonization of brain tissue by breast cancer cells, serving both as active transporters and guiding rails. This is antagonized by inactivation of microglia as well as by the Wnt inhibitor Dickkopf‐2. Proinvasive microglia demonstrate altered morphology, but neither upregulation of M2‐like cytokines nor differential gene expression. Bacterial lipopolysacharide shifts tumor‐educated microglia into a classical M1 phenotype, reduces their proinvasive function, and unmasks inflammatory and Wnt signaling as the most strongly regulated pathways. Histological findings in human brain metastases underline the significance of these results. In conclusion, microglia are critical for the successful colonization of the brain by epithelial cancer cells, suggesting inhibition of proinvasive microglia as a promising antimetastatic strategy. © 2010 Wiley‐Liss, Inc. 相似文献