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   200篇
  免费   7篇
儿科学   8篇
妇产科学   15篇
基础医学   20篇
口腔科学   1篇
临床医学   15篇
内科学   31篇
皮肤病学   12篇
神经病学   8篇
特种医学   4篇
外科学   9篇
综合类   1篇
预防医学   24篇
眼科学   1篇
药学   43篇
中国医学   11篇
肿瘤学   4篇
  2024年   1篇
  2023年   3篇
  2022年   9篇
  2021年   15篇
  2020年   12篇
  2019年   22篇
  2018年   7篇
  2017年   13篇
  2016年   8篇
  2015年   5篇
  2014年   9篇
  2013年   13篇
  2012年   13篇
  2011年   15篇
  2010年   13篇
  2009年   11篇
  2008年   9篇
  2007年   12篇
  2006年   12篇
  2005年   2篇
  2004年   2篇
  2003年   1篇
排序方式: 共有207条查询结果,搜索用时 15 毫秒
11.
12.
The present study has been carried out to investigate the effect of aqueous extract of shallot (Allium ascalonicum) and garlic (Allium satium) on the fasting insulin resistance index (FIRI) and intraperitoneal glucose tolerance test (IPGTT) of fructose-induced insulin resistance rats. Male albino Wistar rats were fed either normal or high-fructose diet for a period of eight weeks. Fasting blood glucose level, fasting blood triglyceride level, FIRI, and the area under the glucose tolerance curve were significantly elevated in fructose-fed animals. Fructose-induced insulin resistance rats treated by aqueous shallot or garlic extract (500 mg/kg body weight/day, i.p.) for duration of eight weeks. Control animals only received normal saline (0.9%). The results showed that neither shallot nor garlic extracts significantly altered the FIRI and the IPGTT at the fourth week after treatment. The fasting blood glucose in fructose-induced insulin resistance animals has been significantly decreased in 8-week treated animals by both shallot and garlic extracts. Shallot extract administration, but not garlic extract, for a period of eight weeks can significantly improve the intraperitoneal glucose tolerance and diminish the FIRI. These results indicate that shallot and garlic extracts have a hypoglycemic influence on the fructose-induced insulin resistance animals and aqueous shallot extract is a stronger hypoglycemic agent than the garlic extract.  相似文献   
13.
Aneuploidy is of great relevance to embryo selection, as it represents one of the important causes of implantation failure. Furthermore, immature oocytes, retrieved during gonadotrophin-stimulated IVF cycles, are generally discarded in clinics; whereas, there was no detectable comprehensive evidence on higher rates of aneuploidy based on maturity status on the day of oocyte retrieval. As well, the correlation between embryo morphology on aneuploidy remains unclear. The aim was to evaluate the developmental and genetic integrity of human preimplantation embryos from rescue in-vitro matured MII stage oocytes as well as in vivo matured oocytes. 541 rescue in-vitro matured oocytes as case as well as 659 in-vivo matured oocytes as control were used for the developmental assay. Finally, 121 cleaved embryos with good quality were analyzed by FISH technique for the detection of chromosomes X, Y, 13, 15, 16, 18, 21 and 22. The fertilization rates were 61.62% and 61.76% in case and control groups, respectively. Also, embryo formation rates of 89.1% vs. 92.2% were recorded for case and control groups, respectively. Good quality embryos on day 3 were 62.54% in case and 68.36% in control groups. There were insignificant differences in fertilization, embryo formation and quality between the groups. Total abnormality in 35 of the 60 embryos was 58.5% in case and 62.3% in control (p < 0.05). There were significant differences between aneuploidy rates of embryos using only sex chromosome preimplantation genetic screening (PGS) and sex chromosome in combination with autosomal chromosomes PGS in case (58.5% vs 28.3%, p = 0.000) and control groups (62.3% vs 21.3%; p = 0.000). The results demonstrated that a high proportion of good quality embryos were aneuploid in both patient groups with no obvious increase in aneuploidies as a result of rescue IVM application. Furthermore, the morphological characteristics of embryos do not completely consistent with chromosomal content. Despite the Rescue IVM is currently not a routine procedure in association with IVF, our finding suggested a viable option for young infertile women facing cancellation of their IVF treatment due to ovarian over-response or resistance factors as well as patients with low functional ovarian reserve considering good quality of embryos from rescue IVM-MII oocytes.  相似文献   
14.
This study aimed to investigate dietary supplement use among Iranian adults in northern Iran. A cross-sectional study was undertaken on randomly selected men and women in Guilan province, northern Iran. The study population was parents of children and adolescents studying in schools. Totally, 1,425 women and 676 men were studied and data on age, body weight, height, educational level, and supplement use was gathered using a self-administrated questionnaire. These data showed that supplement use was related to sex, body mass index, and educational levels in both sexes. Most common supplements used in this population were Iron, calcium, multivitamin/multiminerals and fish oils. These results showed that 13.3, 3.4, 2.2, and 1.1 % of the study men used iron, calcium, multivitamin/multimineral, and fish oil, respectively. In women, 27.1, 10.7, 5.1, and 5.5 % used Iron, calcium, multivitamin/multimineral, and fish oil, respectively. More educated men and women and those with more healthy weight were more likely to use any dietary supplement than the less educated and overweight/obese men and women. This study showed that iron was the most common dietary supplement in this study middle aged Iranians. Using the other supplements was mostly related to age, educational level, and body weight status in this population. These data indicated that dietary supplement use was inversely related to some health-related behaviors and socioeconomic factors.  相似文献   
15.
Objectives: Natural products have a potential role on food intake in mammals. It has been reported that phytohormone abscisic acid (ABA) has a regulatory role on metabolic processes. Here, the effects of ABA on feeding behavior and brain oxidative stress were investigated in male Wistar rats.

Methods: ABA was injected intracerebroventricularly. Experimental groups were included (n = 9): control (received no injection), ABA vehicle (received normal saline), and ABA-treated groups were injected with different doses of ABA (2.5, 5, and 10 μg/rat for 7 days). Daily cumulative daytime and nighttime food consumption, meal frequency, meal duration, and alteration in body weight were recorded. At the end of behavioral experiment, catalase and peroxidase activity and malondialdehyde (MDA) and hydrogen peroxide (H2O2) levels were assayed.

Results: The results showed that ABA (5 and 10 μg) increased the meal frequency. Moreover, ABA could decrease body weight and MDA and H2O2 levels and increased the catalase and peroxidase activities in diencephalon. It also decreased the MDA concentration in the brain stem.

Discussion: Taken together, ABA has an important effect on feeding behavior and body weight in rats likely via increasing antioxidant capacity. However, further studies are still required to determine the underlying mechanisms of ABA on the feeding behavior.  相似文献   
16.
Background: Up-regulation of PIK3R3 (Phosphoinositide-3-Kinase Regulatory Subunit 3), the regulatory subunit of PI3K is correlated with the drug resistance of the glioblastoma cells. In the present study, the effect of PIK3R3 siRNA on erlotinib sensitivity of the U373-MG glioblastoma cells was explored. Methods: After PIK3R3 siRNA transfection, the expression of PIK3R3 mRNA was measured using RT-qPCR. Trypan blue exclusion assay was used to explore the effect of PIK3R3 siRNA on cell proliferation. The effects of PIK3R3 siRNA and erlotinib, alone and in combination, on cell survival and apoptosis were measured using MTT assay and ELISA cell death assay, respectively. Results: Our data showed that PIK3R3 siRNA markedly suppressed the expression of PIK3R3 in a time dependent way, inhibited the proliferation of the U373-MG cells and triggered apoptosis (p <0.05, relative to blank control). Pretreatment with PIK3R3 siRNA synergistically decreased the cell survival rate and lowered the IC50 of erlotinib. Moreover, PIK3R3 siRNA markedly enhanced the apoptotic effect of erlotinib. Conclusions: Our data propose that suppression of PIK3R3 can effectively triggers apoptosis and enhances the sensitivity of the glioblastoma cells to EGFR-TKI erlotinib. Thus, PIK3R3 can be a potential therapeutic target in glioblastoma patients.  相似文献   
17.
Transport of Ag(i), Cd(ii), Co(ii), Cu(ii), Ni(ii), Pb(ii) and Zn(ii) cations across a bulk liquid membrane (BLM) containing N,N′-dibenzyl-N′′-(2,2,2-trifluoroacetyl)-phosphoric triamide (PTC) as a new carrier is studied by atomic absorption spectrometry. The results show selective and efficient transport of the copper(ii) cation from aqueous solution in the presence of the other cations. Various factors are optimized in order to obtain maximum transport efficiency. The PTC ligand is characterized by single crystal X-ray diffraction analysis, IR, NMR (19F, 31P, 1H, 13C) and mass spectroscopy. The complex formation reaction between copper(ii) and PTC is studied by a conductometric method, which shows the 1 : 1 stoichiometry for ligand and copper(ii).

Selective transport of Cu(ii) cation in the presence of six other cations across a bulk liquid membrane containing a novel phosphoric triamide carrier is studied.  相似文献   
18.
Objectives:   The role of endogenous cannabinoids in ischemia/reperfusion induced germ cell apoptosis in rats was investigated.
Methods:   Baseline group was for basal normal values. The Sham operated group served as a control group. The torsion/detorsion (T/D) group underwent torsion (1 h) and detorsion; AN1, AN2, and AN3 groups received anandamide (10 mg/kg) 30 min before torsion, 30 min after torsion, and just after detorsion, respectively. In the AM251 group, AM251 (0.5 mg/kg) was injected 45 min before torsion and in the AN/AM group, AM251 and anandamide were injected 45 and 30 min before torsion, respectively. Lipid peroxidation, antioxidant enzymes, and germ cell apoptosis was determined.
Results:   Malondialdehyde (MDA) levels in the T/D group were significantly higher than the control group. Moreover, MDA values in the AN1, AN2, and AN3 groups were significantly lower than T/D. There were significant decreases in catalase and superoxide dismutase activities in the T/D group versus the control group. These values in the AN1, AN2, and AN3 groups were significantly higher than T/D. It was also shown that MDA levels in the AN/AM group were significantly higher than the AN1 group. In the AN/AM group, catalase and superoxide dismutase activities were significantly lower versus the AN1 group. The mean germ cell apoptosis scores in all animals with testicular T/D were significantly higher than the control group. There was no difference between the apoptotic indices in the AN1, AN2, AN3, and T/D groups. Apoptosis scores in AM251 and AN/AM were significantly higher compared with the T/D and AN1 groups.
Conclusions:   Although anandamide increased antioxidant markers, it failed to reduce germ cell apoptosis. AM251 worsened the antioxidant defense system, which is reflected as higher germ cell apoptosis.  相似文献   
19.
Novel 2-alkylsulfanyl-1-benzyl-5-imidazolecarboxylic acid hydrazides (15a,b) were synthesized as analogues of isocarboxazide, which is a known nonselective irreversible monoamine oxidase inhibitor and tested for monoamine oxidase A and B inhibitory activity. Neither of the compounds showed any inhibition of MAO B activity up to a high concentration of 100 microM. An MAO A activity was only slowly inhibited at this high concentration after prolonged incubation with either compound. This suggests any observed inhibition is not very specific.  相似文献   
20.
A 39-year-old man presented with progressive visual loss in both eyes. His past medical history was remarkable for biopsy-proven bilateral adrenal phaeochromocytomas. Ophthalmoscopy revealed an optic nerve head angioma and macular lipid exudates in the right eye and a regressed optic nerve head angioma in the left eye. A fluorescein angiogram revealed a lobulated pattern of leakage and venous staining from the optic nerve head angioma. Brain and orbital magnetic resonance imaging showed haemangioblastomas of the right intraorbital and left paraclinoid optic nerves and in the left cerebellopontine angle area. These findings were consistent with a clinical diagnosis of von Hippel-Lindau disease.  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