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化妆品去角质效果评价方法研究进展

日用化学品科学 2024年第2期47卷 48-53页

作者：赵聪孙丽丽邹青青刘爱静张晓洁三立慧评(北京)检测技术有限公司北京102401

皮肤角质层是表皮最为重要的组成结构,角质层太厚或太薄都会引起皮肤健康问题,因此化妆品去角质效果的全面、多维度的评价非常必要。《化妆品分类规则和分类目录》中对去角质的释义为有助于促进皮肤角质的脱落或促进角质的更新。从皮肤... 详细信息

皮肤角质层是表皮最为重要的组成结构,角质层太厚或太薄都会引起皮肤健康问题,因此化妆品去角质效果的全面、多维度的评价非常必要。《化妆品分类规则和分类目录》中对去角质的释义为有助于促进皮肤角质的脱落或促进角质的更新。从皮肤角质层的结构及其功能出发,详细介绍了脱落角质的测试方法、角质更新时间的追踪方法以及皮肤角质层表面和内部状态的评价方法,其中皮肤角质层状态评估方式又可以分为图像分析、仪器数据采集分析和主观评价3种方式,并且展望了化妆品去角质效果的评价体系的新发展方向。

关键词：去角质效果角质脱落角质更新评价方法

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Unseen Observation

Sino-US English Teaching 2014年第2期11卷 94-100页

作者： Mahmood Zahran ai-Waaili Ministry of Education Adam Oman

Classroom observation is an essential area that needs to be further investigated due to the role it plays in teachers professional development. However, there is a great dispute about the viability of the current practices by those responsible to evaluate and support teachers. This study aims at investigating the effectiveness of a new supervisory method called ＂Unseen Observation＂（henceforth UO）, a strategy where teachers sit for a pre/post-lesson discussions but with no observer in class. Teachers were interviewed to measure their perceptions of the new method. Various findings were reached as to the level of satisfaction by teachers and their abilities to reflect on their lessons without the presence of the observer in their lessons

关键词： UO (unseen observation) supervision method observers teachers

Mass and charge transport relevant to the formation of toroidal lithium peroxide nanoparticles in an aprotic lithium-oxygen battery： An experimental and theoretical modeling study

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Nano Research 2017年第12期10卷 4327-4336页

作者： Xiangyi Luo Rachid Amine Kah Chun Lau Jun Lu Chun Zhan Larry A. Curtiss Said ai Hallaj Brian P. Chaplin Khalil Amine Chemical Sciences and Engineering Division Argonne National Laboratory 9700 South Cass Avenue Lemont IL 60439 USA Materials Science Division Argonne National Laboratory 9700 South Cass Avenue Lemont IL 60439 USA Department of Chemical Engineering University of Illinois at Chicago 810 S. Clinton Chicago IL 60607 USA Department of Physics and Astronomy California State University Northridge 18111 Nordhoff Street Northridge CA 91330 USA

The discharge and charge mechanisms of rechargeable Li-O2 batteries have been the subject of extensive investigation recently. However, they are not fully understood yet. Here we report a systematic study of the morphological transition of Li2O2 from a single crystalline structure to a toroid like particle during the discharge-charge cycle, with the help of a theoretical model to explain the evolution of the Li2O2 at different stages of this process. The model suggests that the transition starts in the first monolayer of Li2O2, and is subsequently followed by a transition from particle growth to film growth if the applied current exceeds the exchange current for the oxygen reduction reaction in a Li-O2 cell. Furthermore, a sustainable mass transport of the diffusive active species （e.g., O2 and Li＋） and evolution of the underlying interfaces are critical to dictate desirable oxygen reduction （discharge） and evolution （charge） reactions in the oorous carbon electrode of a Li-O2 cell.

关键词： rechargeable Li-O2 battery electrocatalyst nanocomposite lithium peroxide

A multi-step induced strategy to fabricate core-shell Pt-Ni alloy as symmetric electrocatalysts for overall water splitting

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Nano Research 2022年第2期15卷 965-971页

作者： Wenjuan Xu Jinfa Chang Yinggang Cheng Hongqi Liu Jifan Li Yongjian ai Zenan Hu Xinyue Zhang Yiming Wang Qionglin Liang Yang Yang Hongbin Sun Department of Chemistry Northeastern UniversityShenyang 110819China NanoScience Technology Center Department of Materials Science and EngineeringUniversity of Central FloridaOrlandoFL 32826USA Key Laboratory of Bioorganic Phosphorus Chemistry&Chemical Biology(Ministry of Education) Department of ChemistryCenter for Synthetic and Systems BiologyTsinghua UniversityBeijing 100084China

Devising an electrocatalyst with brilliant efficiency and satisfactory durability for hydrogen production is of considerable demand,especially for large-scale ***,we adopt a multi-step consequential induced strategy to construct a bifunctional electrocatalyst for the overall water *** oxide(GO)was used as a carbon matrix and in situ oxygen source,which was supported by the octahedral PtNi alloy to form the PtxNiy-GO *** calcinating in Ar atmosphere,the oxygen in GO induced the surface segregation of Ni from the PtNi octahedron to form a core-shell structure of Ptx@***,the surface-enriched Ni continuously induced the reformation of C in reduced graphene oxide(rGO)to enhance the degree of *** multi-step induction formed a nanocatalyst Pt_(x)@Ni_(y)-rGO which has very high catalytic efficiency and *** optimizing the feeding ratio of PtNi(Pt:Ni=1:2),the electrolytic overall water splitting at 10 mA·cm^(-2) can be driven by an electrolytic voltage of as low as 1.485 V,and hydrogen evolution reaction(HER)only needs an overpotential of 37 mV in 1.0 M KOH aqueous ***,the catalyst exhibited consistent existence form in both HER and oxygen evolution reaction(OER),which was verified by switching the anode and cathode of the cell in the electrolysis of *** work provides a new idea for the synthesis and evaluation of the bifunctional catalysts for water splitting.

关键词： continuous induction core-shell structured Pt@Ni graphene oxide hydrogen evolution reaction alkaline water splitting

A Density Functional Study of the Gold Cages MAu_(16) (M=Si, Ge, and Sn)

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Chinese Physics Letters 2013年第7期30卷 162-166页

作者： TANG Chun-Mei ZHU Wei-Hua ZHANG ai-Mei ZHANG Kai-Xiao LIU Ming-Yi College of Science Hohai UniversityNanjing 210098

Relativistic density functional calculations are performed to explore the promise of MAu_(16)(M=Si,Ge,and Sn)clusters as magic clusters and building blocks in developing cluster-assembled materials.C_(1) and C_(s),two isomers of SiAu_(16),GeAu16 and SnAu_(16) with M(Ge or Sn)at the center of the cage,named,respectively,as SiAu_(16)–C_(1),SiAu_(16)–C_(s),GeAu16-center,and SnAu_(16)-center,are calculated to be the most *** Au–M bond should have both ionic and covalent *** static linear polarizabilities and first-order hyperpolarizabilities are found to be sensitive to the delocalization of the valence electrons of the M atom,as well as their structures and shapes.

关键词： materials. isomers

Depsides from Prunella vulgaris

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Chinese Chemical Letters 2000年第11期11卷 997-1000页

作者： Wang Z.J. Zhao Y.Y. Wang B. ai T.M. Chen Y.Y. Department of Natural Medicines Beijing Medical University Beijing 100083 China

A novel depsides 1, together with three known ones 2-4 and two phenylpropanoids 5-6 were isolated from the ethanol extract of the spikes of Prunella vulgaris. On the basis of spectral and chemical evidence, their structures were deternined as butyl rosmarinate 1, ethyl rosmarinate 2, methyl rosmarinate 3, rosmarinic acid 4, 3,4,α-trihydroxy-methyl phenylpropionate 5 and p-coumaric acid 6, respectively.

关键词： MS acid Wang DMSO 亚砜 FAB

香菇中麦角甾醇的提取纯化、表征及其抗氧化活性

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食品研究与开发 2024年第20期45卷 25-34页

作者：艾洪湖程艳芬云少君刘靖宇冯翠萍曹谨玲山西农业大学食品科学与工程学院山西晋中030801 黄土高原食用菌山西省重点实验室山西晋中030600

为建立一种香菇中麦角甾醇检测的三波长分光光度法,通过单因素试验和响应面试验获得最佳提取条件,并利用溶剂提取法、重结晶法及制备型高效液相法纯化香菇麦角甾醇,对其进行表征及抗氧化活性研究。结果表明,三波长分光光度法可以有效消... 详细信息

为建立一种香菇中麦角甾醇检测的三波长分光光度法,通过单因素试验和响应面试验获得最佳提取条件,并利用溶剂提取法、重结晶法及制备型高效液相法纯化香菇麦角甾醇,对其进行表征及抗氧化活性研究。结果表明,三波长分光光度法可以有效消除杂质和其他背景因素带来的影响,精确测定香菇中麦角甾醇的含量。香菇麦角甾醇的最佳提取条件为超声时间90 min、料液比1∶59(g/mL)、提取温度69℃,麦角甾醇含量的预测值为3.868 78 mg/g,实测值为3.781 4 mg/g。纯化后单体麦角甾醇的纯度可达96%以上,清除DPPH自由基、ABTS+自由基的半数抑制浓度IC_(50)分别为(0.72±0.06)、(0.17±0.01)mg/mL。所建立的方法重复性、稳定性、精密度良好,是一种快速准确测定香菇麦角甾醇的检测方法,且纯化的麦角甾醇具有良好的抗氧化活性。

关键词：香菇麦角甾醇三波长分光光度法提取纯化表征抗氧化

RNA INTERFERENCE OF ANNEXIN II GENE IN PC3 CELLS BY USING SMALL INTERFERENCE RNA SYNTHESIZED WITH IN VITRO TRANSCRIPTION

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Chinese Medical Sciences Journal 2007年第1期22卷 33-37页

作者： Ya-wei Yuan ai-min Sun Ying Lui Long-hua Chen Banerjee A. G Department of Radiotherapy Nanfang Hospital of Nanfang Medical University Guangzhou 510515 Department of Biochemistry and Molecular Biology University. of Nebraska Medical Center Omaha NE 68198-7835 USA

Objective To silence annexin Ⅱ gene expression by using small interference RNA （siRNA） in prostate cancer cell line PC3. Methods For in vitro transcription, four sequences of 29-nucleotide DNA template oligonucleotides were designed, and one pair of the sequences were complementary to annexin Ⅱ gene. The other pair was negative control. The 8 nucleotides at the 3＇ end of each oligonucleotide were complementary to the T7 Promoter Primer. The sense and anti-sense siRNA templates were transcribed by T7 RNA polymerase and the resulting RNA transcripts were hybridized to create dsRNA. The siRNA was transfected into prostate cancer cell PC3. For assaying the efficiency of siRNA, confocal microscopy, Northern blotting, and Western blotting were employed to examine the expression of annexin Ⅱ protein and its mRNA. ^3H thymidine was used to measure DNA synthesis. Results The siRNA sequence specific to annexin Ⅱ gene was capable of inhibiting the expression of annexin Ⅱ protein and its mRNA. And cellular DNA synthesis was significantly reduced in siRNA transfected cells.Conclusions The protocol for the synthesis of siRNA by T7 RNA polymerase is feasible. Annexin Ⅱ might be involved in DNA synthesis.

关键词： small interference RNA gene silencing annexin Ⅱ prostate cancer cell

Relationships between regulated DBPs and emerging DBPs of health concern in U.S. drinking water

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Journal of Environmental Sciences 2022年第7期34卷 161-172页

作者： Stuart W.Krasner ai Jia Chih-Fen T.Lee Raha Shirkhani Joshua M.Allen Susan D.Richardson Michael J.Plewa Metropolitan Water District of Southern California Water Quality LaboratoryCA 91750USA Department of Chemistry and Biochemistry University of South CarolinaSC 29208USA Department of Crop Sciences University of Illinois at Urbana-ChampaignIL 61801USA Safe Global Water Institute University of Illinois at Urbana-ChampaignIL 61801USA

A survey was conducted at eight U.S. drinking water plants, that spanned a wide range of water qualities and treatment/disinfection practices. Plants that treated heavily-wastewaterimpacted source waters had lower trihalomethane to dihaloacetonitrile ratios due to the presence of more organic nitrogen and HAN precursors. As the bromide to total organic carbon ratio increased, there was more bromine incorporation into DBPs. This has been shown in other studies for THMs and selected emerging DBPs(HANs), whereas this study examined bromine incorporation for a wider group of emerging DBPs(haloacetaldehydes, halonitromethanes). Moreover, bromine incorporation into the emerging DBPs was, in general, similar to that of the THMs. Epidemiology studies that show an association between adverse health effects and brominated THMs may be due to the formation of brominated emerging DBPs of heath concern. Plants with higher free chlorine contact times before ammonia addition to form chloramines had less iodinated DBP formation in chloraminated distribution systems, where there was more oxidation of the iodide to iodate(a sink for the iodide) by the chlorine. This has been shown in many bench-scale studies(primarily for iodinated THMs), but seldom in full-scale studies(where this study also showed the impact on total organic iodine. Collectively, the THMs, haloacetic acids, and emerging DBPs accounted for a significant portion of the TOCl, TOBr, and TOI;however, ~50% of the TOCl and TOBr is still unknown. The correlation of the sum of detected DBPs with the TOCl and TOBr suggests that they can be used as reliable surrogates.

关键词： Disinfection by-products Total organic bromine Total organic iodine Trihalomethanes Haloacetonitriles Haloacetaldehydes Iodo-trihalomethanes Iodoacetic acids