天然有色棉防紫外线辐射效果好

当纺织品中存在染料、色素、漆时,可吸收紫外线辐射保护皮肤。经染色的织物防晒性好于漂白的织物。由于天然有色棉中存在色素,可能防晒性更好。将浅绿色、茶色、棕色三种有色棉样品80AFUs(AmericanAssociationofTextileChemistsand Coloristsfadingunits)氙光曝晒并洗涤漂白后防紫外线UPF值为4.3,仍大于未处理常规棉布的UPF值(4.0),具有很好的防晒功能。天然有色棉防紫外线辐射效果好@牛巧鱼     

茶叶延缓皮肤老化的作用

皮肤老化表现为逐渐失去弹性形成皱纹和皮肤外表逐渐产生多种色斑,与细胞衰老和真皮细胞外基质蛋白的降解和结构改变有关。随着环境污染、社会压力、臭氧层变薄和食品安全等问题的日益突出,皮肤问题变得越来越复杂。茶叶富含茶多酚、茶氨酸、茶色素、咖啡碱、茶皂素、茶多糖等生理活性成分,具有滋养皮肤、延缓皮肤衰老的功效,茶元素的护肤品也深受人们的喜爱。本文主要从皮肤细胞衰老和细胞间质老化两个角度阐释茶叶延缓皮肤老化的作用,旨在为饮茶辅助美容养颜及茶叶功能成分在护肤品中的应用提供科学依据。     

萝卜种子简易安全贮藏技术试验

选择合理的包装对于蔬菜种子的安全贮藏至关重要,本试验采用萝卜种子作为材料,采用人工高温高湿加速老化的方法,比较了不同包装材料、干燥剂以及除氧剂延缓萝卜种子老化的效果。结果表明：采用铝箔袋密封包装,包装袋中添加硅胶干燥剂可以有效延缓种子的衰老,除氧剂未观察到延缓种子衰老的作用。以铝箔袋＋硅胶组合包装种子活力效果保持较好。     

茶叶成分抗皮肤光老化作用研究进展

光老化是皮肤受到紫外线照射后所表现出的一系列不同程度的损伤,影响人们的生活质量。茶叶中的活性成分主要有茶多酚、生物碱、茶色素、茶多糖和茶氨酸等。有研究报道茶能够通过一些途径保护皮肤免受紫外损伤,如抗氧化、清除自由基等。本文针对茶叶中的几种主要活性成分在防治皮肤光老化方面的研究现状和应用前景进行了简要综述。     

外界条件对作物叶片衰老的影响

作物叶片是光合作物的重要器官，延缓叶片的衰老，延长叶片的功能期充分掘叶片的光合生产潜力进而提高作物产量具有极其重要的意义，本文就外界条件对作物叶片衰老的影响进行了概念，旨在为今后人地采取调控措施延缓作物叶片的衰老及提高叶片的光合生产量提供理论依据。     

茶叶有效成分对黑色素形成的抑制作用

黑色素是一种高分子生物色素,皮肤的颜色由黑色素的合成类型、累积量、黑素小体的再分布及降解决定.太阳紫外线辐射是导致黑色素形成过多的最常见因素.黑色素虽能保护皮肤细胞免受紫外线损伤,但异常积累将会导致黑色素紊乱疾病的发生.因此开发绿色、安全、高效的植物来源的黑色素抑制剂成为近年来研究的热点.不少研究表明茶叶提取复合物或茶...     

利凉遮阳液在人参上的应用试验总结

<正>利凉遮阳液来自荷兰的高科技遮阳、降温产品,可有效解决春夏季温室大棚内的强光和高温问题,为作物提供理想的生长环境。利凉遮阳液可避免传统遮阳网遮光过多问题,提高作物产量,遮阳更有效。同时,它在温室大棚表面形成白色反光涂层即可以保护温室覆盖,又解决了室内闷热的问题。利凉遮阳液具有遮阳降温、耐风雨和紫外线辐射、延缓棚膜老化、经济实惠、操作简单的特点,在蔬菜大棚及温室上广泛应用,取得良好效果。     

紫外线辐射增强条件下的水稻育种思考

紫外线辐射随着臭氧层的变薄而增强。增强的紫外线B（UV—B）辐射对水稻的生长发育有较大影响。UV—B辐射增强使水稻的光合作用下降,植株矮化,叶面积减小,干物质生产量减少,每株有效穗、每穗总粒数、结实率、千粒重下降,最终导致水稻籽粒产量下降。水稻对UV—B辐射增强的反应具有基因型差异,不同品种间抵抗UV—B辐射作用的能力差异较大。建立抗UV—B辐射的水稻种质资源库,开展抗UV—B辐射的杂交水稻遗传和育种研究,选育抗（耐）UV—B辐射的优质高产及综合性状好的水稻品种（组合）,是提高应对紫外线辐射增强的能力,保证水稻生产持续发展,保证粮食安全的具有前瞻性的重要课题。     

小麦衰老生理

衰老具有普遍性生物学意义.1980年美国著名植物生理学家K.V.Thimann主编的《植物的衰老》(Senescence in Plants)一书认为,"衰老是导致自然死亡的一系列恶化过程".生物经衰老到死亡,是自然规律,但如能认识衰老原因,推迟衰老开始,或延缓衰老进程,尤其是防止早衰(非正常衰     

普洱茶抗辐射作用初探

实验通过紫外线辐射体外培养的NIH-3T3成纤维细胞,观察其损伤情况和普洱茶浸出物对细胞的保护作用,并设置Vit E的阳性对照和蒸馏水的阴性对照,采用MTT法检测细胞增殖活性。结果证明,紫外线辐射可引起NIH-3T3成纤维细胞损伤,Vit E以及普洱茶浸出物均表现出不同程度的抑制紫外线辐射的损伤效果,表明普洱茶具有抗紫外线辐射和保护细胞的作用。     

Dose-Response on the Chemopreventive Effects of Sarcophine-Diol on UVB-Induced Skin Tumor Development in SKH-1 Hairless Mice

Sarcophine-diol (SD) is a lactone ring-opened analogue of sarcophine. It has shown chemopreventive effects on chemically-induced skin tumor development in female CD-1 mice, as well as in a UVB-induced skin tumor development model in hairless SKH-1 mice at a dose of 30 μg SD applied topically and 180 mJ/cm² UVB. The objective of this study was to determine the dose-response on the chemopreventive effects of SD on SKH-1 hairless mice when exposed to a UVB radiation dose of 30 mJ/cm². This UVB dose better represents chronic human skin exposure to sunlight leading to skin cancer than previous studies applying much higher UVB doses. Carcinogenesis was initiated and promoted by UVB radiation. Female hairless SKH-1 mice were divided into five groups. The control group was topically treated with 200 μL of acetone (vehicle), and the SD treatment groups were topically treated with SD (30 μg, 45 μg, and 60 μg dissolved in 200 μL of acetone) 1 h before UVB radiation (30 mJ/cm²). The last group of animals received 60 μg SD/200 μL acetone without UVB exposure. These treatments were continued for 27 weeks. Tumor multiplicity and tumor volumes were recorded on a weekly basis for 27 weeks. Weight gain and any signs of toxicity were also closely monitored. Histological characteristics and the proliferating cell nuclear antigen (PCNA) were evaluated in the mice skin collected at the end of the experiment. The dose-response study proved a modest increase in chemopreventive effects with the increase in SD dose. SD reduced the number of cells positively stained with PCNA proliferation marker in mice skin. The study also showed that SD application without UVB exposure has no effect on the structure of skin. The results from this study suggest that broader range doses of SD are necessary to improve the chemopreventive effects.     

Development and Characterization of VEGF165-Chitosan Nanoparticles for the Treatment of Radiation-Induced Skin Injury in Rats

Radiation-induced skin injury, which remains a serious concern in radiation therapy, is currently believed to be the result of vascular endothelial cell injury and apoptosis. Here, we established a model of acute radiation-induced skin injury and compared the effect of different vascular growth factors on skin healing by observing the changes of microcirculation and cell apoptosis. Vascular endothelial growth factor (VEGF) was more effective at inhibiting apoptosis and preventing injury progression than other factors. A new strategy for improving the bioavailability of vascular growth factors was developed by loading VEGF with chitosan nanoparticles. The VEGF-chitosan nanoparticles showed a protective effect on vascular endothelial cells, improved the local microcirculation, and delayed the development of radioactive skin damage.     

Exploring the Potential of Nannochloropsis sp. Extract for Cosmeceutical Applications

Recently, there has been emerging interest in various natural products with skin protective effects as they are recognized as safe and efficient. Microalgae have developed chemical defense systems to protect themselves against oxidative stress caused by UV radiation by producing various bioactive compounds including a number of secondary metabolites, which have potential for cosmeceutical applications. In addition, microalgae have various advantages as a sustainable source for bioactive compounds with diverse functions due to their rapid growth rate, high productivity, and use of non-arable land. In this study, we aimed to investigate the cosmeceutical potential of ethanol extract from Nannochloropsis sp. G1-5 (NG15) isolated from the southern West Sea of the Republic of Korea. It contained PUFAs (including EPA), carotenoids (astaxanthin, canthaxanthin, β-carotene, zeaxanthin, violaxanthin), and phenolic compounds, which are known to have various skin protective functions. We confirmed that the NG15 extract showed various skin protective functions with low cytotoxicity, specifically anti-melanogenic, antioxidant, skin-moisturizing, anti-inflammatory, anti-wrinkling, and UV protective function, by measuring tyrosinase inhibition activity; melanin content; DPPH radical scavenging activity; expression of HAS-2, MMP-1, and Col1A1 genes; and elastase inhibition activity as well as cell viability after UV exposure. Our results indicated that the NG15 extract has the potential to be used for the development of natural cosmetics with a broad range of skin protective functions.     

Action of a finishing product in the improvement of the ultraviolet protection provided by modal and modal sun fabrics: Modelisation of the effect

The ultraviolet protection factor of a fabric is a quantitative measurement of the effectiveness of the fabric to protect the human skin against ultraviolet radiation. The protection provided by uncoloured cellulosic fabrics is, in general, too low, but can be improved by the finishing treatment with UV-absorbers. In the present paper Modal and Modal Sun fabrics with different compactness, and hence with different initial Ultraviolet Protection Factor values, are treated with several concentrations of an UV-absorber, according to a predefined experimental plan. The influence of each variable as well as their interaction on the response ultraviolet protection factor is analysed and a statistical model for predictions is proposed.     

Chemopreventive Effects of Sarcophine-diol on Ultraviolet B-induced Skin Tumor Development in SKH-1 Hairless Mice

Sarcophine-diol (SD), one of the structural modifications of sarcophine, has shown chemopreventive effects on 12-dimethylbenz(a)anthracene-initiated and 12-O-tetradecanoylphorbol-13-acetate-promoted skin tumor development in female CD-1 mice. The objective of this study was to determine the chemopreventive effects of SD on UVB-induced skin tumor development in hairless SKH-1 mice, a model more relevant to human skin cancer, and to determine the possible mechanisms of action. Carcinogenesis was initiated and promoted by UVB radiation. Female hairless SKH-1 mice were divided into two groups having 27 mice in each group: control and SD treatment. The control group was topically treated with 100 μL acetone and SD treatment group was topically treated with SD (30 μg/100 μL in acetone) 1 hour before each UVB radiation for 32 weeks. Tumor counts were recorded on a weekly basis for 30 weeks. Effects of SD on the expression of caspases were investigated to elucidate the possible mechanism of action. The proteins from epidermal homogenates of experimental mice were used for SDS-PAGE and Western blotting using specific antibodies against caspase-3, caspase-8 and caspase-9 respectively. TUNEL assay was used for determining DNA fragmented apoptotic cells in situ. Results showed that at the end of experiment, tumor multiplicity in control and SD treatment groups was 25.8 and 16.5 tumors per mouse respectively. Furthermore, Topical treatment of SD induced DNA fragmented apoptotic cells by upgrading the expressions of cleaved caspase-3 and caspase-8. This study clearly suggested that SD could be an effective chemopreventive agent for UVB-induced skin cancer by inducing caspase dependent apoptosis.     

Mycosporine-Like Amino Acids Promote Wound Healing through Focal Adhesion Kinase (FAK) and Mitogen-Activated Protein Kinases (MAP Kinases) Signaling Pathway in Keratinocytes

Mycosporine-like amino acids (MAAs) are secondary metabolites found in diverse marine, freshwater, and terrestrial organisms. Evidence suggests that MAAs have several beneficial effects on skin homeostasis such as protection against UV radiation and reactive oxygen species (ROS). In addition, MAAs are also involved in the modulation of skin fibroblasts proliferation. However, the regulatory function of MAAs on wound repair in human skin is not yet clearly elucidated. To investigate the roles of MAAs on the wound healing process in human keratinocytes, three MAAs, Shinorine (SH), Mycosporine-glycine (M-Gly), and Porphyra (P334) were purified from Chlamydomonas hedlyei and Porphyra yezoensis. We found that SH, M-Gly, and P334 have significant effects on the wound healing process in human keratinocytes and these effects were mediated by activation of focal adhesion kinases (FAK), extracellular signal-regulated kinases (ERK), and c-Jun N-terminal kinases (JNK). These results suggest that MAAs accelerate wound repair by activating the FAK-MAPK signaling pathways. This study also indicates that MAAs can act as a new wound healing agent and further suggests that MAAs might be a novel biomaterial for wound healing therapies.     

From Sea to Skin: Is There a Future for Natural Photoprotectants?

In the last few decades, the thinning of the ozone layer due to increased atmospheric pollution has exacerbated the negative effects of excessive exposure to solar ultraviolet radiation (UVR), and skin cancer has become a major public health concern. In order to prevent skin damage, public health advice mainly focuses on the use of sunscreens, along with wearing protective clothing and avoiding sun exposure during peak hours. Sunscreens present on the market are topical formulations that contain a number of different synthetic, organic, and inorganic UVR filters with different absorbance profiles, which, when combined, provide broad UVR spectrum protection. However, increased evidence suggests that some of these compounds cause subtle damage to marine ecosystems. One alternative may be the use of natural products that are produced in a wide range of marine species and are mainly thought to act as a defense against UVR-mediated damage. However, their potential for human photoprotection is largely under-investigated. In this review, attention has been placed on the molecular strategies adopted by marine organisms to counteract UVR-induced negative effects and we provide a broad portrayal of the recent literature concerning marine-derived natural products having potential as natural sunscreens/photoprotectants for human skin. Their chemical structure, UVR absorption properties, and their pleiotropic role as bioactive molecules are discussed. Most studies strongly suggest that these natural products could be promising for use in biocompatible sunscreens and may represent an alternative eco-friendly approach to protect humans against UV-induced skin damage.     

A simulation model to predict the drying time for pasture hay

A hay drying model (HAYDMO) which predicts the moisture content of pasture hay is described. It uses multiple regression equations based on field drying experiments with conditioned and unconditioned hay and predicts hourly changes in moisture content for both day and night and also those due to rain. The model can be used with three different combinations of weather, including hourly wet and dry bulb temperatures, radiation, wind speed and rainfall. Testing HAYDMO revealed a satisfactory agreement between predicted and observed moisture contents     

灰茶尺蠖核型多角体病毒(EgNPV)安全性试验

用20亿PIB/mL灰茶尺蠖病毒(EgNPV)对成年SD大鼠进行急性经口、经皮毒性试验,对白色家兔进行眼刺激和皮肤刺激试验,对豚鼠进行皮肤致敏试验以及进行小鼠急性致病性试验。结果表明20亿PIB/mL灰茶尺蠖病毒(EgNPV)水剂对SD大鼠的急性经口毒性(其LD50雌雄大鼠均5 000 mg/kg)属于低毒;对SD大鼠的急性经皮毒性(其LD50雌雄大鼠均2 000 mg/kg)属于低毒;对家兔的皮肤无刺激性;对家兔的眼睛也无刺激性:在染毒后24 h内不洗眼情况下,眼刺激积分最高为0;对豚鼠的皮肤致敏率为0,其致敏性分级为Ⅰ级,属弱致敏物;病理组织学检查结果表明,各实验组小鼠内脏组织均未见有病理改变,无急性致病性。