全文获取类型
收费全文 | 2496篇 |
免费 | 240篇 |
国内免费 | 109篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 3篇 |
妇产科学 | 19篇 |
基础医学 | 99篇 |
口腔科学 | 81篇 |
临床医学 | 85篇 |
内科学 | 155篇 |
皮肤病学 | 76篇 |
神经病学 | 33篇 |
特种医学 | 30篇 |
外科学 | 63篇 |
综合类 | 353篇 |
现状与发展 | 1篇 |
预防医学 | 710篇 |
眼科学 | 18篇 |
药学 | 486篇 |
中国医学 | 425篇 |
肿瘤学 | 206篇 |
出版年
2024年 | 5篇 |
2023年 | 21篇 |
2022年 | 126篇 |
2021年 | 157篇 |
2020年 | 64篇 |
2019年 | 60篇 |
2018年 | 58篇 |
2017年 | 106篇 |
2016年 | 115篇 |
2015年 | 111篇 |
2014年 | 159篇 |
2013年 | 247篇 |
2012年 | 134篇 |
2011年 | 161篇 |
2010年 | 130篇 |
2009年 | 129篇 |
2008年 | 143篇 |
2007年 | 126篇 |
2006年 | 102篇 |
2005年 | 87篇 |
2004年 | 88篇 |
2003年 | 82篇 |
2002年 | 60篇 |
2001年 | 56篇 |
2000年 | 60篇 |
1999年 | 41篇 |
1998年 | 46篇 |
1997年 | 43篇 |
1996年 | 24篇 |
1995年 | 26篇 |
1994年 | 15篇 |
1993年 | 17篇 |
1992年 | 16篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有2845条查询结果,搜索用时 15 毫秒
61.
Neeta Y. Yousaf Guojun Wu Melania Melis Mariano Mastinu Cristina Contini Tiziana Cabras Iole Tomassini Barbarossa Liping Zhao Yan Y. Lam Beverly J. Tepper 《Nutrients》2022,14(7)
Diet and salivary proteins influence the composition of the oral microbiome, and recent data suggest that TAS2R38 bitter taste genetics may also play a role. We investigated the effects of daily exposure to a cranberry polyphenol oral rinse on taste perception, salivary proteins, and oral microbiota. 6-n-Propylthiouracil (PROP) super-tasters (ST, n = 10) and non-tasters (NT, n = 10) rinsed with 30 mL of 0.75 g/L cranberry polyphenol extract (CPE) in spring water, twice daily for 11 days while consuming their habitual diets. The 16S rRNA gene sequencing showed that the NT oral microbiome composition was different than that of STs at baseline (p = 0.012) but not after the intervention (p = 0.525). Principal coordinates analysis using unweighted UniFrac distance showed that CPE modified microbiome composition in NTs (p = 0.023) but not in STs (p = 0.096). The intervention also altered specific salivary protein levels (α-amylase, MUC-5B, and selected S-type Cystatins) with no changes in sensory perception. Correlation networks between oral microbiota, salivary proteins, and sensory ratings showed that the ST microbiome had a more complex relationship with salivary proteins, particularly proline-rich proteins, than that in NTs. These findings show that CPE modulated the oral microbiome of NTs to be similar to that of STs, which could have implications for oral health. 相似文献
62.
Alessandra DAmico Elena Cavarretta Chiara Fossati Paolo Borrione Fabio Pigozzi Giacomo Frati Sebastiano Sciarretta Vincenzo Costa Fabrizio De Grandis Antonia Nigro Mariangela Peruzzi Fabio Miraldi Wael Saade Antonella Calogero Paolo Rosa Gioacchino Galardo Lorenzo Loffredo Pasquale Pignatelli Cristina Nocella Roberto Carnevale 《Nutrients》2022,14(8)
Mechanisms of exercise-induced muscle injury with etiopathogenesis and its consequences have been described; however, the impact of different intensities of exercise on the mechanisms of muscular injury development is not well understood. The aim of this study was to exploit the relationship between platelet activation, oxidative stress and muscular injuries induced by physical exercise in elite football players compared to amateur athletes. Oxidant/antioxidant status, platelet activation and markers of muscle damage were evaluated in 23 elite football players and 23 amateur athletes. Compared to amateurs, elite football players showed lower antioxidant capacity and higher oxidative stress paralleled by increased platelet activation and muscle damage markers. Simple linear regression analysis showed that sNOX2-dp and H2O2, sCD40L and PDGF-bb were associated with a significant increase in muscle damage biomarkers. In vitro studies also showed that plasma obtained from elite athletes increased oxidative stress and muscle damage in human skeletal muscle myoblasts cell line compared to amateurs’ plasma, an effect blunted by the NOX2 inhibitor or by the cell treatment with cocoa-derived polyphenols. These results indicate that platelet activation increased muscular injuries induced by oxidative stress. Moreover, NOX2 inhibition and polyphenol extracts treatment positively modulates redox status and reduce exercise-induced muscular injury. 相似文献
63.
Ana Paula Rachid Margarida Moncada Maria Fernanda de Mesquita Jos Brito Maria Alexandra Bernardo Maria Leonor Silva 《Nutrients》2022,14(8)
Cinnamon is a spice used in traditional cuisine that has been investigated due to hypoglycemic properties. The objective of this study was to investigate the effect of aqueous cinnamon extract on postprandial glycemia levels in type 2 diabetes mellitus (DM2) adults. This clinical trial enrolled 36 adults with DM2, randomly allocated in two groups: the control group (n = 18) took only an oral glucose tolerance test (OGTT) and the intervention group (n = 18) took OGTT immediately followed by aqueous cinnamon extract (6 g/100 mL) ingestion. Blood glucose levels were measured on fasting and after 30, 60, 90 and 120 min in both groups. The chemical analysis of the aqueous cinnamon extract included total phenols content determination and antioxidant activity assessment through FRAP and DPPH methods. The data reveal that aqueous cinnamon extract ingestion did not show a significant difference in the incremental area under the curve (p = 0.834), maximum glucose concentration (p = 0.527) and glucose concentration variation (p = 0.873) compared with the control group. Cinnamon extract possess a total phenol content of 1554.9 mg/L gallic acid equivalent and a strong antioxidant capacity, revealed by the DPPH (5125.0 µmol Trolox/L) and FRAP (3658.8 µmol Trolox/L) tests. Aqueous cinnamon extract did not significantly influence postprandial glucose response in diabetic patients during an OGTT. 相似文献
64.
Xuanli Liu Gaosheng Hu Anhua Wang Guoqing Long Yongcheng Yang Dongdong Wang Nanfang Zhong Jingming Jia 《Nutrients》2022,14(8)
Black tea was reported to alter the microbiome populations and metabolites in diet-induced obese mice and displays properties that prevent obesity, but the underlying mechanism of the preventative effect of black tea on high-fat diet (HFD) induced obesity has not been elucidated. Epigenetic studies are a useful tool for determining the relationship between obesity and environment. Here, we show that the water extract of black tea (Lapsang souchong, LS) reverses HFD-induced gut dysbiosis, alters the tissue gene expression, changes the level of a major epigenetic modification (DNA methylation), and prevents obesity in HFD feeding mice. The anti-obesity properties of black tea are due to alkaloids, which are the principal active components. Our data indicate that the anti-obesity benefits of black tea are transmitted via fecal transplantation, and the change of tissue gene expression and the preventative effects on HFD-induced obesity in mice of black tea are dependent on the gut microbiota. We further show that black tea could regulate the DNA methylation of imprinted genes in the spermatozoa of high-fat diet mice. Our results show a mechanistic link between black tea, changes in the gut microbiota, epigenetic processes, and tissue gene expression in the modulation of diet-induced metabolic dysfunction. 相似文献
65.
Iwona Szydowska Jolanta Nawrocka-Rutkowska Agnieszka Brodowska Aleksandra Marciniak Andrzej Starczewski Magorzata Szczuko 《Nutrients》2022,14(4)
An analysis of the literature generated within the past 20 year-span concerning risks of uterine fibroids (UFs) occurrence and dietary factors was carried out. A link between Vitamin D deficiency and UFs formation is strongly indicated, making it a potent compound in leiomyoma therapy. Analogs of the 25-hydroxyvitamin D3, not susceptible to degradation by tissue 24-hydroxylase, appear to be especially promising and tend to show better therapeutic results. Although research on the role of Vitamin A in the formation of fibroids is contradictory, Vitamin A-enriched diet, as well as synthetic retinoid analogues, may be preventative or limit the growth of fibroids. Unambiguous conclusions cannot be drawn regarding Vitamin E and C supplementation, except for alpha-tocopherol. Alpha-tocopherol as a phytoestrogen taking part in the modulation of estrogen receptors (ERs) involved in UF etiology, should be particularly avoided in therapy. A diet enriched in fruits and vegetables, as sources of carotenoids, polyphenols, quercetin, and indole-3-carbinol, constitutes an easily modifiable lifestyle element with beneficial results in patients with UFs. Other natural substances, such as curcumin, can reduce the oxidative stress and protect against inflammation in leiomyoma. Although the exact effect of probiotics on uterine fibroids has not yet been thoroughly evaluated at this point, the protective role of dairy products, i.e., yogurt consumption, has been indicated. Trace elements such as selenium can also contribute to antioxidative and anti-inflammatory properties of a recommended diet. In contrast, heavy metals, endocrine disrupting chemicals, cigarette smoking, and a diet low in antioxidants and fiber were, alongside genetic predispositions, associated with UFs formation. 相似文献
66.
Katherine M. Weh Yun Zhang Connor L. Howard Amy B. Howell Jennifer L. Clarke Laura A. Kresty 《Nutrients》2022,14(5)
Esophageal adenocarcinoma (EAC) is a cancer characterized by rapidly rising incidence and poor survival, resulting in the need for new prevention and treatment options. We utilized two cranberry polyphenol extracts, one proanthocyanidin enriched (C-PAC) and a combination of anthocyanins, flavonoids, and glycosides (AFG) to assess inhibitory mechanisms utilizing premalignant Barrett’s esophagus (BE) and EAC derived cell lines. We employed reverse phase protein arrays (RPPA) and Western blots to examine cancer-associated pathways and specific signaling cascades modulated by C-PAC or AFG. Viability results show that C-PAC is more potent than AFG at inducing cell death in BE and EAC cell lines. Based on the RPPA results, C-PAC significantly modulated 37 and 69 proteins in JH-EsoAd1 (JHAD1) and OE19 EAC cells, respectively. AFG treatment significantly altered 49 proteins in both JHAD1 and OE19 cells. Bioinformatic analysis of RPPA results revealed many previously unidentified pathways as modulated by cranberry polyphenols including NOTCH signaling, immune response, and epithelial to mesenchymal transition. Collectively, these results provide new insight regarding mechanisms by which cranberry polyphenols exert cancer inhibitory effects targeting EAC, with implications for potential use of cranberry constituents as cancer preventive agents. 相似文献
67.
The contamination of potential mycotoxins in tea production and consumption has always been a concern. However, the risk monitoring on multiple mycotoxins remains a challenge by existing methods due to the high cost and complex operation in tea matrices. This research has developed a simple ultra-performance liquid chromatography-tandem mass spectrometry strategy based on our homemade purification column, which can be applied in the detections of mycotoxins in complex tea matrices with high-effectively purifying and removing pigment capacity for 16 mycotoxins. The limits of detection and the limits of quantification were in the ranges of 0.015~15.00 and 0.03~30.00 µg·kg−1 for 16 mycotoxins, respectively. Recoveries from mycotoxin-fortified tea samples (0.13~1200 µg·kg−1) in different tea matrices ranged from 61.27 to 118.46%, with their relative standard deviations below 20%. Moreover, this method has been successfully applied to the analysis and investigation of the levels of 16 mycotoxins in major categories of tea and the monitoring of multiple mycotoxins in processed samples of ripened Pu-erh. In conclusion, the proposed strategy is simple, effective, time-saving, and low-cost for the determination of a large number of tea samples. 相似文献
68.
69.
低氟砖茶预防大鼠砖茶型氟中毒的实验观察 总被引:1,自引:1,他引:1
目的 观察低氟砖茶预防砖茶型氟中毒的效果。方法 用低氟砖茶(含氟量210.0mg/kg)和普通砖茶(含氟量503.5mg/kg)制备的茶水喂饲Wistar大鼠,在4,8,12个月时观察动物的日总摄氟量,茶氟在动物体内的代谢情况和氟中毒情况。结果 普通砖茶组动物在0.3mg左右的日总摄氟量时,8个月开始出现以棕、白横纹为主的氟斑牙,12个月后发展为以白垩为主的氟斑牙,患病率达75.0%。低氟砖茶组动物日总摄氟量0.19mg,实验期间未出现氟中毒症状。氟代谢观察表明,半量茶氟通过尿、粪便排出体外,体内吸收的氟绝大部分进入骨骼。结论 低氟砖茶能有效预防砖茶型氟中毒。 相似文献
70.
Vitalini S Gardana C Zanzotto A Simonetti P Faoro F Fico G Iriti M 《Journal of pineal research》2011,51(3):331-337
Melatonin has been reported in a variety of food plants and, consequently, in a number of plant-derived foodstuffs. In grapevine (Vitis vinifera L.) products, it was found in berry exocarp (skin) of different cultivars and monovarietal wines. Herein, we assessed, by means of mass spectrometry, the occurrence of melatonin in all berry tissues (skin, flesh, and seed) at two different phenological stages, pre-véraison and véraison. We detected the highest melatonin content in skin, at pre-véraison, whereas, at véraison, the highest levels were reported in the seed. Furthermore, during ripening, melatonin decreased in skin, while increasing in both seed and flesh. The relative concentrations of melatonin in diverse berry tissues were somewhat different from those of total polyphenols (TP), the latter measured by the Folin-Ciocalteau assay, and more abundant in seed at pre-véraison and in exocarp at véraison. The highest antiradical activity, determined by both DPPH (2,2-diphenyl-1-pycryl hydrazyl) and ABTS [(2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] radical-scavenging assay, was reported at pre-veráison in seed. To the best of our knowledge, we reported, for the first time, the occurrence of melatonin in grape seeds. 相似文献