全文获取类型
收费全文 | 259篇 |
免费 | 13篇 |
国内免费 | 4篇 |
专业分类
妇产科学 | 1篇 |
基础医学 | 8篇 |
口腔科学 | 3篇 |
临床医学 | 4篇 |
内科学 | 14篇 |
皮肤病学 | 16篇 |
神经病学 | 4篇 |
外科学 | 12篇 |
综合类 | 3篇 |
预防医学 | 124篇 |
眼科学 | 17篇 |
药学 | 18篇 |
中国医学 | 10篇 |
肿瘤学 | 42篇 |
出版年
2022年 | 17篇 |
2021年 | 24篇 |
2020年 | 8篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 11篇 |
2015年 | 10篇 |
2014年 | 12篇 |
2013年 | 33篇 |
2012年 | 12篇 |
2011年 | 8篇 |
2010年 | 8篇 |
2009年 | 6篇 |
2008年 | 5篇 |
2007年 | 6篇 |
2006年 | 14篇 |
2005年 | 15篇 |
2004年 | 14篇 |
2003年 | 12篇 |
2002年 | 13篇 |
2001年 | 11篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有276条查询结果,搜索用时 15 毫秒
91.
Intakes of fruits and vegetables,carotenoids and vitamins A,E, C in relation to the risk of bladder cancer in the ATBC cohort study 总被引:9,自引:0,他引:9
Michaud DS Pietinen P Taylor PR Virtanen M Virtamo J Albanes D 《British journal of cancer》2002,87(9):960-965
We examined the relation between dietary fruit and vegetables, carotenoids and vitamin intakes and the risk of bladder cancer among male smokers in a prospective cohort study. Over a median of 11 years, we followed 27 111 male smokers aged 50-69 years who were initially enrolled in the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study. During this period, 344 men developed bladder cancer. All of these men had completed a 276-food item dietary questionnaire at baseline. Cox proportional hazards models were used to estimate the relative risks and 95% confidence intervals and to simultaneously adjust for age, smoking history, energy intake and intervention group. Consumption of fruits and vegetables was not associated with the risk of bladder cancer (relative risk=1.28; 95% confidence intervals CI: 0.89-1.84, for highest vs lowest quintile). Similarly, no associations were observed for groups of fruits or vegetables (berries and cruciferous vegetables), or for specific fruits and vegetables. Dietary intakes of alpha-carotene, beta-carotene, lycopene, lutein/zeaxanthin, beta-cryptoxanthin, vitamins A, E, and C, and folate were not related to the risk of bladder cancer. These findings suggest that fruit and vegetable intakes are not likely to be associated with bladder cancer risk. However, these results may not be generalisable to non-smokers. 相似文献
92.
Holick CN De Vivo I Feskanich D Giovannucci E Stampfer M Michaud DS 《Cancer causes & control : CCC》2005,16(10):1135-1145
Objective: To examine the relation between fruits and vegetables, carotenoids, folate, and vitamins A, C, E and the risk of bladder
cancer in a prospective study of women
Methods: A total of 237 incident bladder cancer cases were documented during 20 years of follow-up among 88,796 women enrolled in
the Nurses’ Health Study. Dietary intake was assessed by food-frequency questionnaires every two to four years and incident
diagnosis of bladder cancer was ascertained every two years. Cox proportional hazard models were used to estimate incidence
rate ratios (RR) and 95% confidence intervals (CI) for bladder cancer risk, adjusting for age, pack-years of smoking, current
smoking, and total caloric intake.
Results: Consumption of total fruits and vegetables was not associated with bladder cancer risk (RR = 1.08, 95% CI = 0.70–1.65, for
> 5.5 compared to < 2.5 servings per day). Similarly, dietary intakes of carotenoids, folate, and vitamins A, C, E, were not
related to bladder cancer risk. No association was observed between supplemental intake of multivitamins, vitamins A, C, E
and bladder cancer risk.
Conclusions: We did not observe any association for fruit and vegetable consumption or vitamin intake and bladder cancer risk among women. 相似文献
93.
McNaughton SA Marks GC Gaffney P Williams G Green AC 《Cancer causes & control : CCC》2005,16(5):609-618
Objective To investigate the relationship between basal cell carcinoma (BCC) and antioxidant nutrients, specifically carotenoids, vitamin E and selenium.Methods The Nambour Skin Cancer Study is an ongoing, community-based study of randomly selected adult residents of a township in sub-tropical Queensland, Australia. Using a nested case–control design, incident cases of BCC (n=90) were compared with age and sex matched controls (n=90). Dietary exposure was measured using food frequency questionnaire estimates of intake as well as serum biomarkers. Other determinants of skin cancer including sun exposure were also considered. Dietary intakes were adjusted for energy intake, and serum carotenoids and vitamin E were adjusted for serum cholesterol. Odds ratios were calculated across quartiles of dietary intake and serum biomarkers and linear trends were assessed using logistic regression, adjusting for age, sex and supplement use.Results and conclusions In this prospective study no significant associations were found between BCC and carotenoids, vitamin E or selenium, as measured by serum biomarkers or dietary intake, although there was a suggestion of a positive association with lutein intake. 相似文献
94.
Leung EY Crozier JE Talwar D O'Reilly DS McKee RF Horgan PG McMillan DC 《International journal of cancer. Journal international du cancer》2008,123(10):2460-2464
Both the tumour growth and progression and the systemic inflammatory response have the potential to increase oxidative stress. We therefore examined the relationship between lipid-soluble antioxidant vitamins, lipid peroxidation, the systemic inflammatory response and survival in patients with primary operable (n = 53) and advanced inoperable (n = 53) colorectal cancer. Compared with those patients with primary operable colorectal cancer, patients with unresectable liver disease had significantly lower median concentrations of alpha-tocopherol (p < 0.001), lutein (p < 0.001), lycopene (p < 0.001), alpha-carotene (p < 0.01) and beta-carotene (p < 0.001) and higher malondialdehyde concentrations. An elevated systemic inflammatory response (Glasgow prognostic score, mGPS) was associated with a greater proportion of females (p < 0.05) and more advanced tumour stage (p < 0.05), lower circulating levels of retinol (p < 0.01), lutein (p < 0.01), lycopene (p < 0.01) and alpha- (p < 0.01) and beta-carotene but not MDA (p = 0.633). In the liver metastases group 41 patients died of their cancer and a further 1 patient died of intercurrent disease on follow-up. On univariate survival analysis, mGPS (p < 0.01), retinol (p < 0.001), alpha-tocopherol (p < 0.05) and alpha-carotene (p < 0.05) were associated significantly with cancer-specific survival. On multivariate survival analysis of these significant variables, only mGPS (p < 0.01) and retinol (p < 0.001) were independently associated with cancer-specific survival. The results of the present study showed that the systemic inflammatory response was associated with a reduction of lipid-soluble antioxidant vitamins, whereas advanced tumour stage was associated with increased lipid peroxidation in patients with colorectal cancer. Of the antioxidant vitamins measured, only retinol was independently associated with cancer-specific survival. 相似文献
95.
《Journal of microencapsulation》2012,29(8):704-714
AbstractAim: The aim of this study was to encapsulate red pepper waste (RPW) bioactives and monitor their stability in yogurt.Methods: RPW extract was encapsulated in whey protein using spray and freeze-drying techniques. Physicochemical characteristics of encapsulates were evaluated, and better encapsulates were used to develop functional yogurt. Retention of bioactives was followed over 21?days of storage, and sensory analyses were assessed.Results: Freeze-dried encapsulates (FDE) showed better characteristics like water activity, moisture content, solubility, flowing and colour properties, and, therefore, incorporated in yogurt. Yogurt with FDE successfully retained carotenoids (71.43%) and caused increasing of polyphenol retention (up to 123.73%). This yogurt exhibited higher sensory and general acceptability scores compared to control sample. The fortification of yogurts had a positive influence on maintaining the initial number of lactic acid bacteria during storage.Conclusion: Freeze drying and utilisation of pepper waste are efficient for functional food development, with improved nutritional, colour and bioactive properties. 相似文献
96.
Miki Tadaishi Yoriko Nishide Yuko Tousen Marlena C. Kruger Yoshiko Ishimi 《Journal of Clinical Biochemistry and Nutrition》2014,54(2):109-115
Osteoclasts play a major role in bone resorption. Several functional food components, such as soy isoflavones and carotenoids, are reported to inhibit osteoclast formation. However, the cooperative effect of functional foods or their constituents on bone metabolism has not been clarified. This study aimed to investigate the cooperative effect of soy isoflavones and carotenoids on osteoclast formation in vitro using cultures of RAW264 and bone marrow cells in the presence of receptor activator of nuclear factor κ-B ligand. In RAW264 cells, treatment with soy isoflavones (genistein or equol) or carotenoids (β-carotene) suppressed osteoclast formation. At 10 µM, genistein and equol inhibited RAW264 cell proliferation but did not affect cell viability. When 10 µM genistein or equol was combined with 0.1 µM β-carotene, we observed an additive suppressive effect on osteoclast differentiation. Similar results were observed with bone marrow cell cultures. We found that 10 µM of zeaxanthin or lutein suppressed osteoclast formation singly, and further enhanced the suppressive effects of daidzein or genistein when administered in combination. These results suggest that the combination of soy isoflavones and carotenoids have an enhanced suppressive effect on osteoclast formation. This knowledge might be important in planning diet for bone health. 相似文献
97.
The effect of exogenous glycine (a precursor for the biosynthesis of bacteriochlorophyll) on the cell growth and photopigment accumulation was investigated in phototrophic growing Rhodobacter azotoformans 134K20. The growth rate and the biomass of strain 134K20 were significantly inhibited by glycine addition when ammonium sulfate or glutamate were used as nitrogen sources and acetate or succinate as carbon sources. A characteristic absorption maximum at approximately 423 nm was present in the absorption spectra of glutamate cultures while it was absent by the addition of high-concentration glycine of 15 mM. The component account for the 423 nm peak was eventually identified as magnesium protoporphyrin IX monomethyl ester, a precursor of bacteriochlorophyll a (BChl a). Comparative analysis of pigment composition revealed that the amount of BChl a precursors was significantly decreased by the addition of 15-mM glycine while the BChl a accumulation was increased. Moreover, glycine changed the carotenoid compositions and stimulated the accumulation of spheroidene. The A850/A875 in the growth-inhibited cultures was increased, indicating an increased level of the light-harvesting complex 2 compared to the reaction center. The exogenous glycine possibly played an important regulation role in photosynthesis of purple bacteria. 相似文献
98.
Sherry A. Tanumihardjo 《Journal of clinical densitometry》2013,16(4):414-419
The role of vitamin A status as it relates to bone health is historical yet controversial. Population-based studies have linked high dietary intake of preformed vitamin A, which is obtained from animal-source foods, fortified foods, and some supplements, to greater risk of osteoporosis and hip fracture. In contrast, carotenoids, some of which are vitamin A precursors from plants, are associated with improved bone health. Carotenoids may be a biomarker that reflects a generally healthy lifestyle, which includes fruit and vegetable consumption. Current dietary recommendations to increase fruit and vegetable intake in the Dietary Guidelines for Americans will result in greater intakes of provitamin A carotenoids if consumers comply. This could lead to artificially high intakes of vitamin A in dietary analyses. However, multiple factors affect the bioconversion of provitamin A carotenoids to the active form of vitamin A. The human body will strive to maintain vitamin A balance by down-regulating provitamin A carotenoid bioconversion. If high preformed vitamin A intake is associated with poor bone health and provitamin A carotenoids are protective, future studies are needed to clarify the associations between total body stores of vitamin A, dietary intake of the pre- and pro-forms, and bone health throughout the life cycle. 相似文献
99.
Sudhir M. Baswan Allison E. Klosner Cathy Weir Dawna Salter-Venzon Kevin W. Gellenbeck Jesse Leverett Jean Krutmann 《Photodermatology, photoimmunology & photomedicine》2021,37(6):490-504
Carotenoids, a class of phytonutrients, have been well established to boost skin's innate resistance against ultraviolet (UV) B-induced erythema (sunburn). Many of the published clinical studies thus far have focused on the measurement of erythema as the primary clinical indicator of skin protection against UVB radiation. More recent studies have shown that carotenoid supplementation provides even more skin protection than previously shown as new clinical and molecular endpoints beyond UVB-induced erythema have been reported. These recent studies have demonstrated that carotenoids also provide photoprotection against UVA-induced pigmentation and inhibit molecular markers of oxidative stress such as intercellular adhesion molecule 1, heme oxygenase-1, and matrix metalloproteinases 1 and 9. This article provides a comprehensive review of the published clinical evidence on skin benefits of carotenoids in the last five decades and indicates new perspectives on the role of ingestible carotenoids in skin protection. 相似文献
100.
PurposeTo estimate the value of macular pigment optical density (MPOD) in adult south Indian population with wet age-related macular degeneration (AMD).MethodsA total of 33 patients with wet AMD and 29 age-matched controls >50 years of age underwent MPOD measurement with the macular densitometer. The patients were also tested for their dietary intake of carotenoids, smoking history, and lifetime UV exposure.ResultsThe mean MPOD values in the Indian population with wet AMD was 0.23 (95% CI: 0.18-0.29) vs control was 0.43 (95% CI: 0.37-0.49), P<0.0001, at 0.5° eccentricity. Ex-smokers had a lower MPOD than non-smokers (0.16 (0.09-0.23) vs 0.28 (0.22-0.34), P=0.026) and the lowest level of carotenoids intake had 48% lower MPOD than the highest level (0.14 (0.08-0.21) vs 0.33 (0.24-0.43), P=0.012). There was no significant age-related decline or gender variation in MPOD.ConclusionThis study establishes the MPOD in adult Indian population with wet AMD, with a lack of macular pigment in association with wet AMD. 相似文献