共查询到18条相似文献,搜索用时 140 毫秒
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本简述了通过测定皮肤中SOD活力,羟脯氨酸,脂质过氧化物和脂褐素含量等这些与评价皮肤衰老有关的生化指标,证实了UVA和UVB长期照射可导致皮肤过早衰老。 相似文献
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紫外线对皮肤的光辐射损伤与防护研究 总被引:11,自引:2,他引:11
研究了阳光紫外线对皮肤造成的各种光辐损伤,探讨了如何采取积极有效的防护措施,各类防晒剂的应用状况,以及防晒化妆品的发展趋势,并对此进行了详细的论述。 相似文献
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紫外线对皮肤的影响及防晒制品 总被引:1,自引:0,他引:1
一、什么是紫外线紫夕P线是日光中的一部分,原指波长在200~400nm之间的不可见光部分。紫外线可分为紫外线短波(UV-C)190~280nm,紫外线中波(UV-B)280~320nm和紫外线长波(UV-A)320~400nm。太阳光是一种电磁辐射能,其能量和波长的关系可由下式表示:式中:E:能量C:光速λ:波长h:普朗克常数由上式可知,太阳光的能量与波长成反比,因此紫外线短波的能量要比紫外线长波的能量大。紫外线短波的能量最大,但这一部分的紫外线被离地球表面约万公里上空的臭氧层吸收,不易射达地面。我们平时所谈的防紫外线大多数情况下是指… 相似文献
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人体衰老过程中伴随着皮肤形态和生理的恶化,并随着年龄的增长而逐渐表现出来,如色素沉积、皱纹、干燥等。光老化是导致皮肤老化的主要原因,因此,研究光老化的信号通路以及探究相关的影响信号通路延缓皮肤衰老的植物提取物具有非常重要的意义。论文综述了调控皮肤光老化的主要信号通路,包括TGF-β1/Smad信号通路、NF-KB信号通路、Nrf2/ARE信号通路和MAPK信号通路,并重点介绍通过调控各种信号通路延缓皮肤衰老的植物提取物。通过对植物提取物抗光老化成分的详细阐述,以期为植物提取物更好地应用到抗衰老化妆品中提供借鉴。 相似文献
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论述日光中另一种成分—红外线对皮肤的影响。红外线除了对紫外线的损害起增强作用外,还通过其热辐射效应使皮肤温度升高,毛细血管扩张,充血,增加表皮水分蒸发等直接对皮肤造成的不良影响。其主要表现为红色丘疹、皮肤过早衰老和色素紊乱。一种经海洋植物生物合成的物质—珊瑚藻,能有效地防止红外线对皮肤的损害,珊瑚藻能够吸收800nm~4000nm波长的光,在1410nm处有一个特征性的强吸收峰。其特点为:1.表面积大;2.孔隙度大;3.导热性低。因此,除了能有效阻断红外线对皮肤的损害,还能缓冲外界剧烈温度变化对皮肤的影响。 相似文献
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紫外线伤害皮肤的机理与防护 总被引:1,自引:0,他引:1
论述了由于人们对臭氧层的破坏导致紫外线对人体皮肤的伤害以及防晒化妆品的防晒机理,人们应该如何科学选用防晒化妆品,同时介绍了防晒化妆品的相关规定。 相似文献
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美白产品始终是夏季护肤品市场竞争的焦点,旁氏推出“日夜美白不停顿”的新概念以应对传统美白产品的挑战,并利用策略发展和广告创意的源动力——“消费者洞察力”概念推出了一套精准的传播策略和创意出色的广告,对消费者产生了很强的吸引力。 相似文献
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讨论开发效果显著的紫外防护产品中的一些问题,并将着重讨论有效添加物。同时,将介绍一种新开发的二氧化钛产品,这种产品能给皮肤带来透明效果。 相似文献
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介绍了防晒剂的相关规定、使用方法、配方及潜在紫外线吸收剂的研制等.指出防水性和光稳定性是防晒霜的必备特性,其配方的组成会影响最终的防晒效果,而通过加快人体自身黑色素的生成和使用化学助褐剂同样可以具有防晒效果. 相似文献
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Kyong-Hwan Chung Hyo-Yun Jung Yong-Wook Lee Ki-Young Lee 《Journal of Industrial and Engineering Chemistry》2010,16(2):261-266
Titanium dioxide (TiO2) sol (TS) or TiO2 nanoparticles with chitosan shell were encapsulated to enhance their sun protection abilities. Nanocapsules loaded with TiO2 were evaluated for their ultraviolet (UV) absorption and UV protection rate. The effect of eicosapentaenoic acid (EPA) incorporation into the nanocapsules was examined in relation to UV absorption. The particle size of TiO2 crystallites in TS was below 30 nm, which was considerably smaller than that of a commercial TiO2 (P25 TiO2) particles. In the encapsulation of TiO2 with chitosan, the loading efficiencies of TS were higher than those of P25 TiO2. The sizes of the nanocapsules loaded with TiO2 particles ranged from 30 to 80 nm. The absorption range of irradiation wavelength was enlarged by the incorporation of EPA into the nanocapsules. The TS-loaded nanocapsules exhibited a high UV protection rate of up to 95% to both UV-A and UV-B. 相似文献
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对国家食品药品监督管理总局发布的防晒化妆品防晒效果标识要求进行了总结与阐释,将新规与旧规进行对比,详细列举了新规下防晒产品防晒指数(SPF)的标识方法,并对法规过渡期内防晒化妆品防晒指数的变更申请情况予以说明。 相似文献
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Alessandro Benedetti Luca Magagnin Francesca Passaretti Elisabetta Chelossi Marco Faimali Giampiero Montesperelli 《Electrochimica acta》2009,54(26):6472-6478
Cathodic protection of metals in seawater is known to be influenced by chemical–physical parameters affecting cathodic processes (oxygen discharge, hydrogen evolution and calcareous deposit precipitation). In shallow seawater, these parameters are influenced by sunlight photoperiod and photosynthetic activity. The results presented here represent the first step in studies dedicated to cathodic protection in shallow photic seawater. This paper reports on carbon steel protected at −850 mV vs. Ag/AgCl (oxygen limiting current regime) in the presence of sunlight radiation but in the absence of biological and photosynthetic activity, the role of which deserves future research. Comparison of results obtained by exposing electrochemical cells to daylight cycles in both biologically inactivated natural seawater and in NaCl 3.5 wt.% solutions showed that sunlight affects current densities and that calcareous deposit interfere with light-currents effects. Sunlight radiation and induced heating of the solution have been separated, highlighting results not otherwise obvious: (1) observed current waves concomitant with sunlight radiation depend fundamentally on solar radiation, (2) solar radiation can determine current enhancements from early to late phases of aragonite crystal growth, (3) a three-day-old CaCO3 layer reduces but does not eliminate the amplitude of the current waves. Theoretical calculations for oxygen limiting currents and additional field tests showed that sunlight, rather than bulk solution heating, is the main cause of daily current enhancements. This was confirmed by polarizations performed at −850 and −1000 mV vs. Ag/AgCl (constant bulk temperature), during which the electrode was irradiated with artificial lighting. This test also confirmed O2 discharge to be the cathodic process involved. A mechanism of radiation conversion to heat in the oxygen diffusion layer region is proposed. 相似文献