全文获取类型
收费全文 | 843篇 |
免费 | 52篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 40篇 |
妇产科学 | 18篇 |
基础医学 | 104篇 |
口腔科学 | 35篇 |
临床医学 | 75篇 |
内科学 | 167篇 |
皮肤病学 | 29篇 |
神经病学 | 35篇 |
特种医学 | 81篇 |
外科学 | 76篇 |
综合类 | 38篇 |
预防医学 | 28篇 |
眼科学 | 34篇 |
药学 | 75篇 |
中国医学 | 1篇 |
肿瘤学 | 55篇 |
出版年
2023年 | 8篇 |
2022年 | 18篇 |
2021年 | 30篇 |
2020年 | 19篇 |
2019年 | 21篇 |
2018年 | 32篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 25篇 |
2014年 | 30篇 |
2013年 | 34篇 |
2012年 | 60篇 |
2011年 | 54篇 |
2010年 | 31篇 |
2009年 | 28篇 |
2008年 | 28篇 |
2007年 | 31篇 |
2006年 | 35篇 |
2005年 | 31篇 |
2004年 | 27篇 |
2003年 | 16篇 |
2002年 | 20篇 |
2001年 | 29篇 |
2000年 | 11篇 |
1999年 | 10篇 |
1998年 | 29篇 |
1997年 | 20篇 |
1996年 | 23篇 |
1995年 | 19篇 |
1994年 | 10篇 |
1993年 | 9篇 |
1991年 | 5篇 |
1990年 | 7篇 |
1989年 | 12篇 |
1988年 | 13篇 |
1987年 | 14篇 |
1986年 | 11篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 10篇 |
1976年 | 11篇 |
1975年 | 3篇 |
1972年 | 5篇 |
1969年 | 3篇 |
1968年 | 4篇 |
排序方式: 共有916条查询结果,搜索用时 15 毫秒
51.
Fábio S Lira José C Rosa Gustavo D Pimentel Victor AF Tarini Ricardo M Arida Flávio Faloppa Eduardo S Alves Cláudia O do Nascimento Lila M Oyama Marília Seelaender Marco T de Mello Ronaldo VT Santos 《Lipids in health and disease》2010,9(1):1-10
Introduction
Cytokines (IL-6, IL-10 and TNF-α) are increased after exhaustive exercise in the rat retroperitoneal (RPAT) and mesenteric adipose tissue (MEAT) pads. On the other hand, these cytokines show decreased expression in these depots in response to a chronic exercise protocol. However, the effect of exercise with overload combined with a short recovery period on pro- and anti-inflammatory cytokine expression is unknown. In the present study, we investigated the regulation of cytokine production in the adipose tissue of rats after an overtraining-inducing exercise protocol.Methods
Male Wistar rats were divided into four groups: Control (C), Trained (Tr), Overtrained (OT) and recovered overtrained (R). Cytokines (IL-6, TNF-α and IL-10) levels and Toll Like Receptor 4 (TLR4), Nuclear Factor kBp65 (NF-kBp65), Hormone Sensitive Lipase (HSL) and, Perilipin protein expression were assessed in the adipose tissue. Furthermore, we analysed plasma lipid profile, insulin, testosterone, corticosterone and endotoxin levels, and liver triacylglycerol, cytokine content, as well as apolipoprotein B (apoB) and TLR4 expression in the liver.Results
OT and R groups exhibited reduced performance accompanied by lower testosterone and increased corticosterone and endotoxin levels when compared with the control and trained groups. IL-6 and IL-10 protein levels were increased in the adipose tissue of the group allowed to recover, in comparison with all the other studied groups. TLR-4 and NF-kBp65 were increased in this same group when compared with both control and trained groups. The protein expression of HSL was increased and that of Perilipin, decreased in the adipose in R in relation to the control. In addition, we found increased liver and serum TAG, along with reduced apoB protein expression and IL-6 and IL-10 levels in the of R in relation to the control and trained groups.Conclusion
In conclusion, we have shown that increases in pro-inflammatory cytokines in the adipose tissue after an overtraining protocol may be mediated via TLR-4 and NF-kBp65 signalling, leading to an inflammatory state in this tissue. 相似文献52.
Mirella Youssef Tawfik Rehab Ali Mohamed 《Zeitschrift fur Gesundheitswissenschaften》2016,24(2):153-164
Aim
This study aims to investigate the effect of a cardiovascular risk (CVR) communication intervention on the accuracy of CVR perception, diabetes self-care (DSC), glycosylated hemoglobin percent (HbA1c%), and CVR in patients with type 2 diabetes mellitus (T2DM).Subject and methods
A randomized controlled trial was performed in T2DM patients attending the family medicine outpatient clinic in Suez Canal University Hospital, Ismailia. The intervention group (n?=?107) received a comprehensive CVR communication. Control subjects (n?=?107) received the standard usual care. The outcome measures were: accuracy of risk perception, DSC, HbA1c%, and CVR scores. Patients were investigated at baseline and 3 months after the intervention. Differences between arms were assessed using chi-square and Student's t-test, and within-group differences were assessed using the paired t-test and McNemar’s test.Results
After the intervention, the accuracy rate of risk perception was significantly improved (from 44.9 % to 89.7 %) in the intervention group with excellent improvement in agreement between perceived and objective risk (kappa?±?SE 83.7?±?4.4 %, p?<?0.000). Diabetes self-care sum scale scores and HbA1c% showed statistically significant improvements for within-intervention group comparisons and between groups after the intervention (p?<?0.000). Cardiovascular risk scores showed minimal, not statistically significant improvement in both groups.Conclusion
Our intervention significantly improved CVR perception, DSC, and HbA1c% in patients with T2DM. Further research is needed to investigate the effectiveness of applying more complex and longer lifestyle interventions and to confirm the credibility and sustainability of improvement.53.
Atif S. Tantawy Magda N. A. Nasr Magda A. A. El-Sayed Samar S. Tawfik 《Medicinal chemistry research》2012,21(12):4139-4149
A new series of 4-substituted 3-methyl-1,5-diphenyl-1H-pyrazoles 4–11 has been synthesized and evaluated for its in vitro antiviral activity and cytotoxicity against herpes simplex virus type-1 grown on Vero African green monkey kidney cells through plaque-reduction assay method using acyclovir as a positive control. The synthesis was achieved through Claisen-Schmidt condensation reaction of 3-methyl-1,5-diphenyl-1H-pyrazole-4-carbaldehyde (3) with acetophenone derivatives to give various enones 4a–f which are considered an important synthon for the construction of different heterocyclic rings as isoxazoline, pyrazoline, pyrimidine, pyridine, and fused pyridine via several synthetic routes. Biological evaluation of the prepared compounds showed that 3-(4-methylphenyl)-5-(3-methyl-1,5-diphenyl-1H-pyrazol-4-yl)-4,5-dihydroisoxazole (5f), 6-(4-methylphenyl)-N-[(3-(methylsulfanyl)phenyl)]-4-(3-methyl-1,5-diphenyl-1H-pyrazol-4-yl)pyrimidin-2-amine (7), 6-(4-bromophenyl)-4-(3-methyl-1,5-diphenyl-1H-pyrazol-4-yl)-2-oxo-1,2-dihydropyridine-3-carbonitrile (8), and 2-amino-6-(4-bromophenyl)-4-(3-methyl-1,5-diphenyl-1H-pyrazol-4-yl) pyridine-3-carbonitrile (9) exhibited strong antiviral activity with IC50 (0.02, 0.04, 0.03, 0.03), respectively, compared to the used reference drug. The synthesized compounds were characterized by physical constants and the structures of the title compounds were confirmed by IR, 1H NMR, mass spectra, and elemental analyses. 相似文献
54.
Allele and genotype frequencies of CYP2B6 and CYP2C19 polymorphisms in Egyptian agricultural workers
Ellison CA Abou El-Ella SS Tawfik M Lein PJ Olson JR 《Journal of toxicology and environmental health. Part A》2012,75(4):232-241
Genetic variability in cytochrome P-450 (CYP) has the potential to modify pharmacological and toxicological responses to many chemicals. Both CYP2B6 and CYP2C19 are pharmacologically and toxicologically relevant due to their ability to metabolize multiple drugs and environmental contaminants, including the organophosphorus (OP) pesticide chlorpyrifos. The aim of this study was to determine the prevalence of CYP2B6 and CYP2C19 variants in an indigenous Egyptian population (n = 120) that was shown to be occupationally exposed to chlorpyrifos. Further, the genotyping data was compared for Egyptians with previously studied populations to determine between population differences. Allelic frequencies were CYP2B6 1459C > T (3.8%), CYP2B6 785A > G (30.4%), CYP2B6 516G > T (28.8%), CYP2C19 681G > A (3.8%), and CYP2C19 431G > A (0%). The most prevalent CYP2B6 genotype combinations were CYP2B6 *1/*1 (44%), *1/*6 (38%), *6/*6 (8%), and *1/*5 (6%). The frequency of the CYP2C19 genotype combinations were CYP2C19 *1/*1 (93%), *1/*2 (6%), and *2/*2 (1%). The frequency of the CYP2B6 516G > T and CYP2B6 785A > G polymorphisms in this Egyptian cohort is similar to that found North American and European populations but significantly different from that reported for West African populations, while that of CYP2B6 1459C > T is similar to that found in Africans and African Americans. The observed frequency of CYP2C19 681G > A in Egyptians is similar to that of African pygmies but significantly different from other world populations, while CYP2C19 431 G > A was significantly different from that of African pygmies but similar to other world populations. 相似文献
55.
Mamdouh Ali Kotb Tatsuya Mima Yoshino Ueki Tahamina Begum Amal Tawfik Khafagi Hidenao Fukuyama Takashi Nagamine 《Clinical neurophysiology》2005,116(5):1195-1200
OBJECTIVE: Recent transcranial magnetic stimulation (TMS) studies showed that the sensory input can decrease the motor cortex excitability (afferent inhibition). To clarify the effect of attention on sensorimotor integration, we investigated the effect of spatial attention on afferent inhibition. METHODS: Right median nerve electrical stimulation followed, at variable delays (10-300 ms), by TMS over the left motor cortex was applied to 9 subjects, during 3 conditions; spatial attention to the right and left hand, and control (no attention) tasks. RESULTS: Inhibition of the motor evoked potential occurred at inter-stimulus interval of 20 and 100 ms, which was more was marked during spatial attention to the right than to the left hand. CONCLUSIONS: Enhancement of the afferent inhibition induced by spatial attention to the stimulated side is likely to reflect the interaction between attention and sensorimotor integration. SIGNIFICANCE: The spatial attention may modulate the sensorimotor integration studied by afferent inhibition of the MEP. 相似文献
56.
目的:观察低血糖指数的膳食对2型糖尿病患者氧化应激状态的影响。方法:2004-10/11在上海市静安区二个社区卫生服务中心招募受试者,经医生明确诊断为2型糖尿病、病程超过6个月,体质量指数≥24kg/m2的老年糖尿病志愿者43名,受试者对试验知情同意。采用随机交叉试验随机分配至低血糖指数饮食组和高血糖指数饮食组,每种膳食分别连续使用4周,间隔洗脱期4周,比较试验前后患者超氧化物歧化酶、脂质过氧化产物丙二醛和谷胱甘肽过氧化物酶含量的变化。结果:受试者依从性好,除1人因试验期间发现肿瘤而退出试验,42名志愿者按设计要求完成试验。膳食干预后低血糖指数饮食组和高血糖指数饮食组的超氧化物歧化酶活力分别升高了15.68%和21.33%,丙二醛水平分别下降23.94%和21.55%,谷胱甘肽过氧化物酶活力分别升高了15.74%和17.09%;干预后低血糖指数饮食组丙二醛下降水平与高血糖指数饮食组比较差异有显著性意义(P<0.05),而超氧化物歧化酶和谷胱甘肽过氧化物酶活性两组间差异无显著性意义(P>0.05)。结论:在控制总能量的基础上给予平衡膳食能够改善其氧化应激水平,采用低血糖指数食物有助于氧化应激水平的改善。 相似文献
57.
Emir UE Raatz S McPherson S Hodges JS Torkelson C Tawfik P White T Terpstra M 《NMR in biomedicine》2011,24(7):888-894
In this study, ascorbate (Asc) and glutathione (GSH) concentrations were quantified noninvasively using double-edited (1)H MRS at 4 T in the occipital cortex of healthy young [age (mean ± standard deviation) = 20.4 ± 1.4 years] and elderly (age = 76.6 ± 6.1 years) human subjects. Elderly subjects had a lower GSH concentration than younger subjects (p < 0.05). The Asc concentration was not significantly associated with age. Furthermore, the lactate (Lac) concentration was higher in elderly than young subjects. Lower GSH and higher Lac concentrations are indications of defective protection against oxidative damage and impaired mitochondrial respiration. The extent to which the observed concentration differences could be associated with physiological differences and methodological artifacts is discussed. In conclusion, GSH and Asc concentrations were compared noninvasively for the first time in young vs elderly subjects. 相似文献
58.
Efficacy of propentofylline, a glial modulating agent, on existing mechanical allodynia following peripheral nerve injury 总被引:11,自引:0,他引:11
Tawfik VL Nutile-McMenemy N Lacroix-Fralish ML Deleo JA 《Brain, behavior, and immunity》2007,21(2):238-246
Increasing evidence points to a role for spinal neuroimmune dysregulation (glial cell activation and cytokine expression) in the pathogenesis of chronic pain. Suppression of astrocytic and microglial activation with the methylxanthine derivative, propentofylline, pre-emptively attenuates the development of nerve injury-induced allodynia. Currently, we investigated the ability of systemic propentofylline to reverse existing, long-term allodynia after nerve injury--a clinically relevant paradigm. Rats received L5 spinal nerve transection or sham surgery and the development of mechanical allodynia was assessed daily for 2 weeks, at which time injured rats exhibited robust responses to non-noxious von Frey filaments. On days 14-27, rats received either saline or 101 mg/kg propentofylline by intraperitoneal (i.p.) injection. On day 28 or 42 (after a 14-day drug washout period), lumbar spinal cord sections were processed for assessment of astrocytic glial fibrillary acidic protein (GFAP) and microglial OX-42 (antibody against CR3/CD11b). Propentofylline treatment to nerve injured rats resulted in significant reversal of allodynia that lasted throughout the 14-day washout period. Spinal microglial activation was observed at days 28 and 42 post-injury at the protein level, in the absence of mRNA level changes. Less robust increases in GFAP immunoreactivity were observed at days 28 and 42 post-transection. Interestingly, propentofylline treatment suppressed microglial activation at both time points in this paradigm. Taken together, our results highlight the clinical potential of the glial modulating agent, propentofylline, for the treatment of neuropathic pain as well as a role for microglia in the long-term maintenance of allodynia. 相似文献
59.
Goris Gbenou MC Wahidy T Llinares K Cracco D Perrot A Riquet D 《Case reports in oncology》2011,4(3):542-546
Background
Cutaneous metastases from colorectal cancer are uncommon, accounting for 6.5% of all secondary skin lesions. They occur in advanced disease. The most common site is the abdomen. The penis is a rare site.Case Report
We report the case of a 79-year-old patient who presented, two years after rectocolectomy for a rectal adenocarcinoma, obstructive renal failure secondary to a presacral recurrence, as well as symptomatic phimosis associated with papulonodules invading the penis, scrotum and pubis. After hemodialysis, percutaneous pyelostomy, and double-J catheter placement, the patient underwent circumcision and a pubic skin biopsy. On histology and immunohistochemistry, a cutaneous metastasis originating from the rectal adenocarcinoma was diagnosed.Conclusions
Penile invasion by colorectal cancer revealed by phimosis is a rare occurrence but needs to be recognized and promptly diagnosed by biopsy in order to propose appropriate adjuvant therapy. These rare lesions can occur without any liver or lung involvement.Key words: Colorectal cancer, Phimosis, Penile metastasis, Cutaneous metastasis 相似文献60.