Effect of α-Lipoic Acid on the Development of Human Skin Equivalents Using a Pumpless Skin-on-a-Chip Model

Owing to the prohibition of cosmetic animal testing, various attempts have recently been made using skin-on-a-chip (SOC) technology as a replacement for animal testing. Previously, we reported the development of a pumpless SOC capable of drug testing with a simple drive using the principle that the medium flows along the channel by gravity when the chip is tilted using a microfluidic channel. In this study, using pumpless SOC, instead of drug testing at the single-cell level, we evaluated the efficacy of α-lipoic acid (ALA), which is known as an anti-aging substance in skin equivalents, for skin tissue and epidermal structure formation. The expression of proteins and changes in genotyping were compared and evaluated. Hematoxylin and eosin staining for histological analysis showed a difference in the activity of fibroblasts in the dermis layer with respect to the presence or absence of ALA. We observed that the epidermis layer became increasingly prominent as the culture period was extended by treatment with 10 μM ALA. The expression of epidermal structural proteins of filaggrin, involucrin, keratin 10, and collagen IV increased because of the effect of ALA. Changes in the epidermis layer were noticeable after the ALA treatment. As a result of aging, damage to the skin-barrier function and structural integrity is reduced, indicating that ALA has an anti-aging effect. We performed a gene analysis of filaggrin, involucrin, keratin 10, integrin, and collagen I genes in ALA-treated human skin equivalents, which indicated an increase in filaggrin gene expression after ALA treatment. These results indicate that pumpless SOC can be used as an in vitro skin model similar to human skin, protein and gene expression can be analyzed, and it can be used for functional drug tests of cosmetic materials in the future. This technology is expected to contribute to the development of skin disease models.     

小型核桃脱壳分选一体机的设计

核桃不仅营养价值极高,而且核桃壳的药用价值也非常高,国内小企业和家庭在核桃硬壳脱壳加工环节,一般采用人工破壳取仁的方式,这种方式劳动强度大,人工成本高且不卫生;针对这个问题设计了一款小型的硬壳脱壳,壳仁分离分选的机器来提高生产效率,减少成本,提高收入。     

AQP3 Increases Intercellular Cohesion in NSCLC A549 Cell Spheroids through Exploratory Cell Protrusions

Tumor cell aggregation is critical for cell survival following the loss of extracellular matrix attachment and dissemination. However, the underlying mechanotransduction of clustering solitary tumor cells is poorly understood, especially in non-small cell lung cancers (NSCLC). Here, we examined whether cell surface protrusions played an important role in facilitating the physical contact between floating cells detached from a substrate. We employed poly-2-hydroxyethyl methacrylate-based 3D culture methods to mimic in vivo tumor cell cluster formation. The suprastructural analysis of human NSCLC A549 cell spheroids showed that finger-like protrusions clung together via the actin cytoskeleton. Time-lapse holotomography demonstrated that the finger-like protrusions of free-floating cells in 3D culture displayed exploratory coalescence. Global gene expression analysis demonstrated that the genes in the organic hydroxyl transport were particularly enriched in the A549 cell spheroids. Particularly, the knockdown of the water channel aquaporin 3 gene (AQP3) impaired multicellular aggregate formation in 3D culture through the rearrangement of the actomyosin cytoskeleton. Moreover, the cells with reduced levels of AQP3 decreased their transmigration. Overall, these data indicate that cell detachment-upregulated AQP3 contributes to cell surface protrusions through actomyosin cytoskeleton remodeling, causing the aggressive aggregation of free-floating cells dependent on the property of the substratum and collective metastasis.     

Colossal dielectric response and relaxation behavior in novel system of Zr4+ and Nb5+ co-substituted CaCu3Ti4O12 ceramics

In this work, we developed a novel system of isovalent Zr⁴⁺ and donor Nb⁵⁺ co-doped CaCu₃Ti₄O₁₂ (CCTO) ceramics to enhance dielectric response. The influences of Zr⁴⁺ and Nb⁵⁺ co-substituting on the colossal dielectric response and relaxation behavior of the CCTO ceramics fabricated by a conventional solid-phase synthesis method were investigated methodically. Co-doping of Zr⁴⁺ and Nb⁵⁺ ions leads to a significant reduction in grain size for the CCTO ceramics sintered at 1060 °C for 10 h. XRD and Raman results of the CaCu₃Ti_3.8-xZr_xNb_0.2O₁₂ (CCTZNO) ceramics show a cubic perovskite structure with space group Im-3. The first principle calculation result exhibits a better thermodynamic stability of the CCTO structure co-doped with Zr⁴⁺ and Nb⁵⁺ ions than that of single-doped with Zr⁴⁺ or Nb⁵⁺ ion. Interestingly, the CCTZNO ceramics exhibit greatly improved dielectric constant (~10⁵) at a frequency range of 10²–10⁵ Hz and at a temperature range of 20–210 °C, indicating a giant dielectric response within broader frequency and temperature ranges. The dielectric properties of CCTZNO ceramics were analyzed from the viewpoints of defect-dipole effect and internal barrier layer capacitance (IBLC) model. Accordingly, the immensely enhanced dielectric response is primarily ascribed to the complex defect dipoles associated with oxygen vacancies by co-doping Zr⁴⁺ and Nb⁵⁺ ions into CCTO structure. In addition, the obvious dielectric relaxation behavior has been found in CCTZNO ceramics, and the relaxation process in middle frequency regions is attributed to the grain boundary response confirmed by complex impedance spectroscopy and electric modulus.     

Bi-templated grain growth maximizing the effects of texture on piezoelectricity

Templated grain growth is beneficial for piezoelectric materials, the properties of which become the best in their single crystalline form. Nevertheless, a textured ceramic prepared by a templated grain growth technique often fails in exhibiting as good properties as expected in single crystals even with a high degree of orientation factor. Here, we propose a new strategy for maximizing texturing effect by suppressing the growth of untextured matrix grains. The textured ceramics made by our method, so-called bi-templated grain growth, are featured by ultrahigh piezoelectric properties (d₃₃ = ～1,031 pC/N, d?g = ～59,000, k_p = ～0.76). A special emphasis is on the achieved electric-field-induced strain of 0.13 % at 1 kV/mm, which is as high as that of single crystals. This work demonstrates that not only the degree of texture but also the coarsening of untextured matrix grains should be well-controlled to best exploit the templated grain growth technique.     

Electrodeposition of B,Ni co-doped diamond-like carbon films on AZ91D magnesium alloy: Corrosion and wear resistance

Diamond-like carbon (DLC) possesses brilliant and excellent properties, including excellent corrosion resistance as well as outstanding wear resistance. Ni and B co-doped DLC films were deposited on AZ91D magnesium alloy by electrodeposition under mild conditions (300 V and 25°C). Uniform and dense morphology of co-doped DLC films were observed, and Ni and B were uniformly incorporated into the carbon-based films. Among all the electrodeposits, the appearance of D and G peaks near 1330 and 1570 cm⁻¹ revealed that the as-deposited films were typical DLC films. As the addition of Ni was increased to 0.05 g, the highest microindentation hardness, the lowest friction coefficient, and wear loss were achieved to be 164.5 HV, 0.3, and 0.6 × 10⁻⁵ kg/m, respectively. The amorphous carbon films fabricated at 0.05 g Ni had the lowest corrosion current density and the most positive corrosion potential, which was mainly due to the small and dense granular structure effectively hindering the penetration of corrosion media.     

Optimization of sensitizer concentration for upconversion photoluminescence of Yb3+/Er3+: La10W22O81 nanophosphor rods

Yb³⁺/Er³⁺codoped La₁₀W₂₂O₈₁ (LWO) nanophosphor rods have been successfully synthesized by a facile hydrothermal assisted solid state reaction method, and their upconversion photoluminescence properties were systematically studied. X-ray diffraction patterns revealed that the nanophosphors have an orthorhombic structure with space group Pbcn (60). A microflowers-like morphology with irregular hexagonal nanorods was observed using field emission scanning electron microscopy for the Yb³⁺(2 mol%)/Er³⁺(2 mol%):LWO nanophosphor. The shape and size of the nanophosphor and the elements along with their ionic states in the material were confirmed by TEM and XPS studies, respectively. A green upconversion emission was observed in the Er³⁺: LWO nanophosphors under 980 nm laser excitation. A significant improvement in upconversion emission has been observed in the Er³⁺: LWO nanophosphors by increasing the Er³⁺ ion concentration. A decrease in the upconversion emission occurred due to concentration quenching when the doping concentration of Er³⁺ ions was greater than 2 mol%. An optimized Er³⁺(2 mol%): LWO nanophosphor exhibited a strong near infrared emission at 1.53 μm by 980 nm excitation. The green upconversion emission of Er³⁺(2 mol%): LWO was remarkably enhanced by co-doping with Yb³⁺ ions under 980 nm excitation because of energy transfer from Yb³⁺ to Er³⁺. The naked eye observed this upconversion emission when co-doping with 2 mol% Yb³⁺. In order to obtain the high upconversion green emission, the optimized sensitizer concentration of Yb³⁺ ions was found to be 2 mol%. The upconversion emission trends were studied as a function of stimulating laser power for an optimized sample. Moreover, the NIR emission intensity has also been enhanced by co-doping with Yb³⁺ ions due to energy transfer from Yb³⁺ to Er³⁺. The energy transfer dynamics were systematically elucidated by energy level scheme. Colorimetric coordinates were determined for Er³⁺ and Yb³⁺/Er³⁺: LWO nanophosphors. The energy transfer mechanism was well explained and substantiated by several fluorescence dynamics of upconversion emission spectra and CIE coordinates. The results demonstrated that the co-doped Yb³⁺(2 mol%)/Er³⁺(2 mol%): LWO nanophosphor material is found to be a suitable candidate for the novel upconversion photonic devices.     

Self-healing capacity of Mullite-Yb2SiO5 environmental barrier coating material with embedded Ti2AlC MAX phase particles

Repetitive heating and cooling cycles inevitably cause crack damage of hot gas components of gas turbine engines, such as blades and vanes. In this study the self-healing capacity is investigated of mullite + ytterbium monosilicate (Yb₂SiO₅) as EBC material with Ti₂AlC MAX phase particles embedded as a crack-healing agent. The effect of Ti₂AlC in the EBC was compared with the self-healing ability of the mullite + Yb₂SiO₅ material. After introducing cracks by Vickers indentation on the surface of each sample, crack healing was realized by controlling the temperature and time during the post-heat-treatment process. For the mullite + Yb₂SiO₅ composite with Ti₂AlC particles, crack healing occurred at 1000 °C, while in the case of the mullite + Yb₂SiO₅ composite without Ti₂AlC, a sustained temperature of 1300 °C or higher was required. Compared with the healing of the mullite + Yb₂SiO₅ composite by the formation of a eutectic phase, the addition of Ti₂AlC promoted healing via the oxidation of Ti and Al. Notably, the surface formation of a ternary oxide of Ti–Yb–O was confirmed, which completely covered the damage area. Consequently, the addition of a Ti₂AlC MAX phase to the EBC composite resulted in a complete strength recovery, while the mullite + Yb₂SiO₅ composite without Ti₂AlC showed a strength recovery of about 80%. Furthermore, by analyzing the indentation load–displacement curve to indicate the role of Ti₂AlC, the addition of Ti₂AlC improved both the hardness and stiffness of the composite.     

Enhanced the photocatalytic activity of B–C–N–TiO2 under visible light:Synergistic effect of element doping and Z-scheme interface heterojunction constructed with Ag nanoparticles

In order to enhance the photocatalytic activity of TiO₂ under visible light, Ag nanoparticles were introduced into tridoped B–C–N–TiO₂ (TT) catalyst by photoreduction deposition. Ag/B–C–N–TiO₂ (ATT) catalysts with the functions of reducing band gap and carrier recombination were prepared. At the same time, the effect of the amount of Ag on the photocatalytic performance of ATT catalyst was investigated. Through XRD, XPS, PL and other characterization methods, the (211)/(101)/Ag interface heterojunction mechanism similar to the traditional Z-scheme heterojunction was proposed. The intervention of Ag nanoparticles changed the P–N interface heterojunction between (211)/(101) to the (211)/(101)/Ag Z-scheme interface heterojunction. The results show that ATT catalyst exhibits the highest photocatalytic activity when the molar amount of Ag is 0.005% with the MB degradation rate of the ATT catalyst (0.01707 min^?1), which is 14.59 times of TiO₂ (0.00117 min^?1) and 2.02 times of TT (0.00847 min^?1). In addition, the four cycles efficiencies of ATT for MB degradation were all above 94.00%.This study reveals the possibility of construction of Z-scheme heterojunctions between precious metal nanoparticles and different interfaces of TiO₂, and provides a reference for the construction of Z-scheme interface heterojunctions.     

气藏平均地层压力跟踪计算新方法

平均地层压力是产能评价和动态分析的基础，准确、快速获取平均地层压力对高效开发气藏意义重大。基于地层压力随时间变化的规律，分析了平均地层压力的变化规律。研究结果表明：平均地层压力等效点仅随时间发生改变，平均地层压力的下降速率等于或者近似等于井底流压的下降速率。从封闭弹性驱动气藏的物质平衡方程出发，考虑偏差系数和井底流压随平均地层压力的变化，推导建立了平均地层压力跟踪计算新方法，根据生产数据可迭代计算平均地层压力。方法验证结果显示，采气速度和采出程度共同影响模型的计算结果。应用实例表明，跟踪计算法与压力恢复试井和物质平衡法之间的相对误差均较小，满足工程计算精度要求，且跟踪计算法不需依托生产测试数据，节约了测试费用，避免了测试占产。