Topical proteolytic enzymes affect epidermal and dermal properties

Although proteolytic enzymes have a history of use in skin care products it is not known whether they simply induce superficial exfoliation or with continued use can alter epidermal and dermal skin properties. We examined herein whether enhanced exfoliation resulting from treatment with an aspartyl dependent acid protease produces appearance improvements and over time, changes in the epidermis and dermis. Test participants applied 15% enzyme containing serum and a simple moisturizer twice daily for 3 months; a matched control group applied the same serum (without enzyme) and moisturizer. Changes in skin smoothness and texture, the depth and number of lines and wrinkles, and epidermal and dermal firmness and thickness were examined in a double-blind fashion. Treatment with 15% enzyme product(s) resulted in significant improvement in epidermal properties after 1 month and both epidermal and dermal properties after 3 months. The control group showed modest improvements in surface properties only. These results demonstrate that significant appearance benefits can be derived from use of exfoliative proteolytic enzymes. Such improvements are the result of changes to the epidermis and dermis and are strikingly similar to results observed with higher concentrations of AHAs (alpha hydroxy acids).     

复合土钉墙在黄土地层基坑支护中的应用

概述了黄土质基坑的破坏成因,并以某电厂翻车机室基坑的支护为例,概述了场地的工程地质概况以及选用的支护方式,根据土质基坑的破坏模型进行基坑的稳定性验算并调整设计参数,确定最终设计方案。同时介绍了支护方案,即复合土钉墙的施工技术应用,基坑的变形监测;总结了施工经验和体会。     

复杂地层跟管钻进套管强度的有限元分析

针对复杂地层的跟管钻进技术进行研究,分析了跟管钻具的受力情况,并对易损部件进行有限元分析,对实践过程中出现的问题进行改进以及对套管螺纹结构的优化设计,提出了改进方案。     

钻探中泥浆性能的调整

在钻探生产过程中,为了适应各种不同岩性的地层泥浆性能的要求,单靠粘土和水的加量是不够的,还要加入化学药剂来改善或控制泥浆性能。实践证明只有根据孔内的具体情况,科学地运用化学处理剂来调整泥浆的性能,才能实现优质高速钻进的目标。     

Effect of AlInGaN barrier layers with various TMGa flows on optoelectronic characteristics of near UV light-emitting diodes grown by atmospheric pressure metalorganic vapor phase epitaxy

Near ultraviolet light-emitting diodes (LEDs) with quaternary AlInGaN quantum barriers (QBs) are grown by atmospheric pressure metalorganic vapor phase epitaxy. The indium mole fraction of AlInGaN QB could be enhanced as we increased the TMG flow rate. Both the wavelength shift in EL spectra and forward voltage at 20 mA current injection were reduced by using AlInGaN QB. Under 100 mA current injection, the LED output power with Al_0.089In_0.035Ga_0.876N QB can be enhanced by 15.9%, compared to LED with GaN QB. It should be attributed to a reduction of lattice mismatch induced polarization mismatch in the active layer.     

Stratum corneum free amino acids following barrier perturbation and repair

Modulation of the skin environment after stratum corneum (SC) perturbation has profound effects on the rate and effectiveness of barrier repair. Intermediate water exposure, e.g. moderate relative humidity, may provide the optimum water gradient for SC repair. More rapid recovery with semipermeable (SP) films in vivo was associated with increased hydration measured as moisture accumulation rate. We hypothesized that (i) damaged SC recovering under the high water exposure of full occlusion (FO) would have lower free amino acids (FAA) than sites with low hydration (no occlusion, NO) and semi‐occlusion (SP, semipermeable film, intermediate hydration) and (ii) SC under semi‐occlusion would have higher FAA than with low hydration. Volar forearm sites in 15 healthy adults were perturbed via cellophane tape stripping and treated with SP, FO and NO for five days. Barrier recovery rate, hydration, dryness and erythema were determined. Serial SC samples (n = 15) were collected on day 5 and FAA quantified using reverse‐phase HPLC and fluorescence detection. The cumulative protein removed was higher for SP than the control, NO and FO. FAA as total, individual amino acids and citrulline were consistently higher in the control than the three damaged sites. Generally, FAA was higher in NO than FO. Citrulline was higher for NO than SP and FO over the sampled SC. Levels were higher for SP than FO in certain, but not all of the FAAs. FAA was inversely correlated to barrier integrity. Skin hydration was relatively constant at the external microenvironment of the SP site, whereas the NO and FO had a reduction, i.e. a gradient, over the time. Overall, barrier recovery under conditions of a decreasing hydration gradient produced SC with higher levels of FAA than did conditions of full occlusion.     

Thermoelectric properties of quaternary chalcogenide Cu2ZnSnS4 synthesised by mechanical alloying

ABSTRACT

The quaternary chalcogenide Cu₂ZnSnS₄ has emerged as a potential thermoelectric (TE) material due to its low thermal conductivity (κ), high Seebeck coefficient (S) and composition including earth-abundant, low-cost and non-toxic elements. In this work, Cu₂ZnSnS₄ was synthesised from a mixture of Cu, Zn, Sn and S powders using a mechanical alloying method. As a result, Cu₂ZnSnS₄ powders were formed after 16?h of milling, without additional heat treatment. After milling, the powders were heat-treated at 723?K for 24?h and then sintered by spark plasma sintering under an applied pressure of 60?MPa at 873?K for 10?min. The heat-treated Cu₂ZnSnS₄ sample showed a wide-band-gap of 1.49?eV. The sintered Cu₂ZnSnS₄ sample exhibited S and κ values of 170 μV K^?1 and 1.06 W m^?1 K^?1, respectively with an electrical conductivity σ of 1240 S m^?1 and a dimensionless figure of merit (ZT) of 0.022 at 663?K.     

Enhanced low-temperature catalytic performance in CO2 hydrogenation over Mn-promoted NiMgAl catalysts derived from quaternary hydrotalcite-like compounds

Mn-promoted NiMgAl mixed-oxide (NiMnx-LDO, x = 0, 5, 10, 15) catalysts derived from hydrotalcite were synthesized using co-precipitation for CO₂ hydrogenation to synthetic natural gas. By regulating Mn contents, NiMn5-LDO delivered the most excellent catalytic performance, being about 2 times higher than that of undoped NiMn0-LDO catalyst (TOF of NiMn5-LDO and NiMn0-LDO: 0.61 s⁻¹ vs 0.31 s⁻¹ @ 240 °C). Through extensive characterization, it was found that Mn dopants promoted the reduction of bulk NiO through tuning the interaction between Ni and Mg(Mn)AlOx support. A high surface ratio of Ni⁰/Ni²⁺ was achieved over NiMn5-LDO. Furthermore, the surface basicity strength was tailored by Mn dopants. With 5 wt% of Mn, NiMn5-LDO catalyst showed a stronger medium-strength basicity and higher capacity of CO₂ adsorption than others. Particularly, TOF indicates a good correlation with medium-strength basicity over NiMnx-LDO catalysts. The strong metal-support interaction originated from the hydrotalcite structure kept nickel uniformly dispersed, endowing to the improved catalytic performance.     

Comprehensive characterization of CIGS absorber layers grown by one-step sputtering process

We have demonstrated that the use of a one-step sputtering process allowed for the fabrication of copper indium gallium diselenide (CIGS) thin films by RF magnetron sputtering without an additional selenization process. The CIGS thin films deposited at different substrate temperatures were synthesized on soda-lime glass (SLG) substrates using a single quaternary CIGS target. The film composition ratios of ([Cu]/[In]+[Ga]), ([Ga]/[In]+[Ga]), and ([Se]/[Cu]+[In]+[Ga]) were almost consistent with those of the sputtering target. X-ray diffraction (XRD) and Raman results showed that the crystallinity of the CIGS thin films was gradually improved as substrate temperatures increased. Transmission electron microscopy (TEM) showed that the films grown at 600?°C have a columnar structure with the grain size of ~100?nm. In addition, for the CIGS films grown at 600?°C, TEM-EDX analysis revealed that the synchronized fluctuation of the Cu and Se signals was observed in the direction of the film depth, while the In and Ga signals were constant. As a result, the CIGS solar cell made using the film showed a degraded cell efficiency of 2.5%, which might be have been caused by not only Cu-rich and Se-poor compositions but the locally unstable composition in the CIGS films fabricated by one-step sputtering.     

山东东部白垩系莱阳群沉积地层与有机质特征

为了解山东东部白垩系莱阳群沉积地层，研究有机质特征，在对灵山岛、崂山垭口-八仙墩及胶莱盆地的典型剖面地层野外踏勘的基础上，结合灵山岛元素地球化学、胶莱盆地有机地球化学的相关研究成果，采用了沉积学、沉积地球化学、有机地球化学的研究方法手段，系统研究了灵山岛莱阳群地层的有机质特征。胶莱盆地早白垩世莱阳期主要发育一套河湖相及冲积扇相的陆相沉积地层，有机地球化学研究表明，其水南段烃源岩样品主要为腐泥型（Ⅰ型）和腐殖腐泥型（Ⅱ₁型），已进入生烃门限，处于热演化成熟阶段；而灵山岛、崂山垭口-八仙墩早白垩世莱阳期则主要发育深水重力流、深水牵引流为主的海相沉积地层，对灵山岛粉砂岩和页岩进行元素地球化学研究指示了其沉积环境为海相还原环境，且有机地球化学研究表明，灵山岛样品为腐殖型（Ⅲ型）和腐殖腐泥型（Ⅱ₁型），处于高成熟到过成熟阶段，灵山岛浊积岩可能已经完成了生排烃过程。