全文获取类型
收费全文 | 502篇 |
免费 | 49篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 1篇 |
妇产科学 | 5篇 |
基础医学 | 29篇 |
口腔科学 | 20篇 |
临床医学 | 28篇 |
内科学 | 33篇 |
皮肤病学 | 39篇 |
神经病学 | 16篇 |
特种医学 | 6篇 |
外科学 | 17篇 |
综合类 | 47篇 |
预防医学 | 48篇 |
眼科学 | 9篇 |
药学 | 168篇 |
中国医学 | 82篇 |
肿瘤学 | 33篇 |
出版年
2024年 | 1篇 |
2023年 | 9篇 |
2022年 | 18篇 |
2021年 | 22篇 |
2020年 | 17篇 |
2019年 | 13篇 |
2018年 | 25篇 |
2017年 | 21篇 |
2016年 | 17篇 |
2015年 | 22篇 |
2014年 | 34篇 |
2013年 | 38篇 |
2012年 | 37篇 |
2011年 | 33篇 |
2010年 | 30篇 |
2009年 | 29篇 |
2008年 | 38篇 |
2007年 | 23篇 |
2006年 | 30篇 |
2005年 | 18篇 |
2004年 | 17篇 |
2003年 | 13篇 |
2002年 | 9篇 |
2001年 | 9篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有582条查询结果,搜索用时 15 毫秒
21.
目的观察表没食子儿茶素没食子酸酯(EGCG)对实验性大鼠肺纤维化的干预作用及可能的作用机制。方法大鼠随机分为正常对照组、模型组、醋酸泼尼松组和EGCG大、中、小剂量组。通过气管内注入博莱霉素(BLM)复制大鼠肺纤维化模型,于造模后d 2各治疗组开始给药,给药后d7、14、28处死大鼠,取肺组织,观察形态学变化,并测定生化指标。结果EGCG能减少实验性肺纤维化大鼠肺组织中胶原沉积及降低肺系数(P<0.05,P<0.01),提高T-AOC、SOD水平(P<0.05,P<0.01),减轻肺部的病理损害。结论EGCG对BLM诱导产生的大鼠肺纤维化有一定的抑制作用。 相似文献
22.
Recently, in addition to carboxylesterases (CESs), we found that arylacetamide deacetylase (AADAC) plays an important role in the metabolism of some clinical drugs. In this study, we screened for food-related natural compounds that could specifically inhibit human AADAC, CES1, or CES2. AADAC, CES1, and CES2 activities in human liver microsomes were measured using phenacetin, fenofibrate, and procaine as specific substrates, respectively. In total, 43 natural compounds were screened for their inhibitory effects on each of these enzymes. Curcumin and quercetin showed strong inhibitory effects against all three enzymes, whereas epicatechin, epicatechin gallate (ECg), and epigallocatechin gallate (EGCg) specifically inhibited AADAC. In particular, ECg and EGCg showed strong inhibitory effects on AADAC (IC50 values: 3.0 ± 0.5 and 2.2 ± 0.2 μM, respectively). ECg and EGCg also strongly inhibited AADAC-mediated rifampicin hydrolase activity in human liver microsomes with IC50 values of 2.2 ± 1.4 and 1.7 ± 0.4 μM, respectively, whereas it weakly inhibited p-nitrophenyl acetate hydrolase activity, which is catalyzed by AADAC, CES1, and CES2. Our results indicate that ECg and EGCg are potent inhibitors of AADAC. 相似文献
23.
目的观察表没食子儿茶素没食子酸酯(EGCG)对柔红霉素(DNR)所致心肌损伤小鼠抗氧化作用的影响。方法昆明种小鼠随机分为空白对照组、模型组、EGCG高剂量组(80 mg/kg)、EGCG低剂量组(40 mg/kg)。空白对照组和模型组小鼠灌胃给予等体积生理盐水。给药7 d后,除空白对照组外,其余各组小鼠腹腔注射DNR(15 mg/kg)。48 h后取血,观察各组小鼠的血清和心肌组织的超氧化物歧化酶(SOD)、丙二醛(MDA)。结果模型组小鼠血清MDA含量显著高于空白对照组(P<0.05),SOD活性明显低于空白对照组(P<0.05)。EGCG高、低剂量组血清MDA含量显著低于模型组(P<0.05),EGCG高、低剂量组血清SOD活性则显著高于模型组(P<0.05)。模型组小鼠心肌MDA含量显著高于空白对照组(P<0.01),SOD活性明显降低(P<0.05)。EGCG高、低剂量组心肌MDA含量显著低于模型组(P<0.05),EGCG高剂量组心肌SOD活性显著高于模型组(P<0.05)。结论 EGCG对柔红霉素诱导的小鼠心肌损伤有一定的抗氧化作用。 相似文献
24.
Kuo-Chi Chang Jia Jang Yang Elizabeth Che-Hsiang Wang-Hsu Tsai-Hsien Chiu Fu-Chun Hsu 《Neuroscience letters》2009
(−)Epigallocatechin-3-gallate (EGCG), a tea catechin, has been known to cause many biological actions, such as anxiolytic and hypotensive effects in behavioral studies. However, to date, few reports investigate its neuronal modulation. In this study, intracellular recording was used to test the neuronal modulation of different catechins on locus coeruleus (LC) neuron, which has been demonstrated to be affected by cardiovascular function regulation and stressful events. Several catechins (1–1000 μM) were tested, including: (−)catechin (C), (−)catechingallate (CG), (−)epicatechin (EC), (−)epicatechin-3-gallate (ECG), (−)epigallocatechin (EGC) and EGCG. The results showed that catechins EC, ECG, EGC and EGCG could inhibit the spontaneous firing of the LC neurons; furthermore, these catechins show potency and efficacy in the order of EGCG > ECG > EC ≈ EGC. Among the tested catechins, EGCG was the most potent in inhibiting LC's spontaneous firing with IC50 of 20.5 μM. This caused us to further examine the EGCG's desensitization and tolerance properties. When continuously administering EGCG at 1–300 μM for 20 min, no acute desensitization appeared. However, repeated applications of 300 μM EGCG at 5 min each time showed different results. The second and third applications induced less responses compared to that of the first application, suggesting a development of tolerance towards EGCG in inhibiting LC neuronal activity. Our data suggest that EGCG can inhibit LC neuron's spontaneous firing in a dose-dependent manner, with developed tolerance only when high concentration of EGCG is repeatedly applied. 相似文献
25.
Sooyoung Kim Tae H. Park Woo I. Kim Suyeon Park Jae H. Kim Moon K. Cho 《Phytotherapy research : PTR》2021,35(1):374-383
Green tea extract (GTE) has been studied for the treatment of acne based on its anti‐inflammatory/antioxidant properties. This systematic review and meta‐analysis aimed to examine the effects of GTE on acne. Electronic databases, including PubMed, Embase, and the Cochrane Library were systematically searched up to August 2019. The effect size of acne lesion counts is presented as mean differences and 95% confidence intervals (CIs). Five randomized‐controlled studies were included in the meta‐analysis (N; experimental = 125, control = 122). GTE significantly reduced the number of inflammatory lesions (?9.38; 95% CI: ?14.13 to ?4.63). In subgroup analysis, topical GTE application significantly reduced the inflammatory lesion counts (?11.39; 95% CI: ?15.91 to ?6.86) whereas oral GTE intake showed minimal effect (?1.40; 95% CI: ?2.50 to ?0.30). Although GTE did not significantly reduce the number of non‐inflammatory lesions (?21.65; 95% CI: ?47.52 to 4.22), when stratified by the route of admission, non‐inflammatory acne lesions were significantly reduced by topical GTE application (?32.44; 95% CI: ?39.27 to ?25.62) but not with oral GTE administration (0.20; 95% CI: 0.00 to 0.40). This systematic review and meta‐analysis suggest that topical GTE application is beneficial for the treatment of acne without causing significant adverse events while oral GTE intake has limited effects. Further high‐quality clinical trials are warranted. 相似文献
26.
目的:观察表没食子儿茶素没食子酸酯(EGCG)对垂体后叶素(Pit)所致大鼠急性心肌缺血的保护作用。方法:采用大鼠舌下静脉注射Pit复制急性心肌缺血模型,观察EGCG(40 mg/kg、20 mg/kg、10 mg/kg)对Ⅱ导联心电图(ECG)ST段、急性缺血性心律失常、血清心肌酶学及心肌脂质过氧化的影响。结果:EGCG(40 mg/kg、20 mg/kg)能降低Pit所致的急性心肌缺血大鼠ECGST段的抬高,对抗急性缺血性心律失常,减少心肌细胞磷酸肌酸激酶和乳酸脱氢酶的释放,提高心肌组织中超氧化物歧化酶活性,降低心肌组织丙二醛含量。结论:EGCG对大鼠急性心肌缺血具有保护作用,其机制可能与清除自由基,抑制脂质过氧化反应有关。 相似文献
27.
28.
Dimitrios Stagos Gregorios D. Amoutzias Antonios Matakos Argyris Spyrou Aristides M. Tsatsakis Dimitrios Kouretas 《Food and chemical toxicology》2012
Primary liver cancer or hepatocellular carcinoma (HCC) is one of the most frequent tumors representing the fifth commonest malignancy worldwide and the third cause of mortality from cancer. Currently, the treatments for HCC are not so effective and new strategies are needed for its fight. Chemoprevention, the use of natural or synthetic chemical agents to reverse, suppress or prevent carcinogenesis is considered an important way for confronting HCC. Many of the chemopreventive agents are phytochemicals, namely non-nutritive plant chemicals with protective or disease preventive properties. In this review, we focus on plant polyphenols, one of the most important classes of phytochemicals, their chemopreventive properties against HCC and discuss the molecular mechanisms accounting for this activity. 相似文献
29.
Pon Velayutham Anandh Babu Kuruvimalai Ekambaram Sabitha Chennam Srinivasulu Shyamaladevi 《Food and chemical toxicology》2008,46(1):280-285
Diabetes leads to modification of collagen such as advanced glycation and cross-linking which play an important role in the pathogenesis of diabetes mellitus. We have investigated the effect of green tea on modification of collagen in streptozotocin (60 mg/kg body weight) induced diabetic rats. To investigate the therapeutic effect of green tea, treatment was begun six weeks after the onset of diabetes and green tea extract (300 mg/kg body weight) was given orally for 4 weeks. The collagen content, extent of advanced glycation, advanced glycation end products (AGE) and cross-linking of tail tendon collagen were investigated. Green tea reduced the tail tendon collagen content which increased in diabetic rats. Accelerated advanced glycation and AGE in diabetic animals, as detected by Ehrlich's-positive material and collagen linked fluorescence respectively were reduced significantly by green tea. The solubility of tail tendon collagen decreased significantly in diabetic rats indicating a remarkable increase in the cross-linking, whereas green tea increases the solubility of collagen in diabetic rats. The present study reveals that green tea is effective in reducing the modification of tail tendon collagen in diabetic rats. Thus green tea may have a therapeutic effect in the treatment of glycation induced complications of diabetes. 相似文献
30.
Mechanisms and Effects of Green Tea on Cardiovascular Health 总被引:1,自引:1,他引:1
Green tea, rich in antioxidant and anti-inflammatory catechins, especially epigallocatechin gallate (EGCG), has been shown to reduce surrogate markers of atherosclerosis and lipid peroxidation, particularly LDL oxidation and malondialdehyde concentrations, in several in vitro, animal, and limited clinical studies. Epidemiological observations in Southeast Asian countries indicate an inverse correlation exists between habitual consumption of green tea beverages and the incidence of cardiovascular events. A few short-term clinical studies have reported its effects in attenuating biomarkers of oxidative stress and inflammation among smokers, and an ability to decrease postprandial lipemia in hypercholesterolemic subjects has also been suggested. However, further investigations are needed to confirm the potential role of green tea beverages and the safety of green tea supplements in reducing body fat, as well as other biomarkers of cardiovascular disease risks. 相似文献