Electropolishing Behaviour of 73 Brass in a 70 vol % H3PO4 Solution by Using a Rotating Cylinder Electrode (RCE)

The electropolishing behaviour of 73 brass was studied by means of a rotating cylinder electrode (RCE) in a 70 vol % H3PO4 solution at 27 °C. Owing to the formation of a blue Cu2+-rich layer on the brass-RCE, an obvious transition peak was detected from kinetic- to diffusion-controlled dissolution in the anodic polarisation curve. Electropolishing was conducted at the potentials located at the transition peak, the start, the middle, and the end positions in the limiting-current plateau corresponding to the anodic polarisation curve of the brass-RCE. A well-polished surface can be obtained after potentiostatic electropolishing at the middle position in the limiting-current plateau. During potentiostatic etching in the limiting-current plateau, a blue Cu2+-rich layer was formed on the brass-RCE, reducing its anodic dissolution rate and obtaining a levelled and brightened brass-RCE. Moreover, a rod climbing phenomenon of the blue Cu2+-rich layer was observed on the rotating brass-RCE. This enhances the coverage of the Cu2+-rich layer on the brass-RCE and improves its electropolishing effect obviously

Anneal-Hardening Behavior of Cr-Fe-C Alloy Deposits Prepared in a Cr3+-Based Bath with Fe2+ Ions

Cr-Fe-C alloy deposits were successfully prepared on high-carbon tool steel in a Cr3+-based electroplating bath containing Fe2+ ions and suitable complex agents. A Cr-based alloy deposit was obtained with an electroplating current density higher than 25 Adm−2, and a Fe-based alloy deposit was obtained using a current density of 20 Adm−2. Following electroplating, these alloy deposited specimens were annealed via rapid thermal annealing (RTA) at 500 °C for different periods up to 30 s. The experimental results show that Cr- and Fe-based alloy deposits could be significantly hardened after RTA at 500 °C for a few seconds. The maximum hardness was that of the Cr-Fe-C alloy deposit annealed at 500 °C for 10 s. The maximum hardness of 1205 Hv was detected from the annealed Cr-based alloy deposit prepared with 30 ASD. The hardening mechanism of annealed Cr- and Fe-based alloy deposits is attributed to the precipitation of C-related membranes. The hardness values of the annealed Cr- and Fe-based alloy deposits increase with the increasing degree of crystallization of the C-related membranes

Insight into the Substrate Specificity of <i>Lactobacillus paracasei</i> Aspartate Ammonia-Lyase

Aspartate ammonia-lyase (AAL) catalyzes the reversible conversion reactions of aspartate to fumaric acid and ammonia. In this work, Lactobacillus paracasei LpAAL gene was heterologously expressed in Escherichia coli. As well as a recombinant His-tagged LpAAL protein, a maltose-binding protein (MBP) fused LpAAL protein was used to enhance its protein solubility and expression level. Both recombinant proteins showed broad substrate specificity, catalyzing aspartic acid, fumaric acid, phenylalanine, and tyrosine to produce fumaric acid, aspartic acid, trans-cinnamic acid, and p-coumaric acid, respectively. The optimum reaction pH and temperature of LpAAL protein for four substrates were measured at 8.0 and 40 °C, respectively. The Km values of LpAAL protein for aspartic acid, fumaric acid, phenylalanine, and tyrosine as substrates were 5.7, 8.5, 4.4, and 1.2 mM, respectively. The kcat values of LpAAL protein for aspartic acid, fumaric acid, phenylalanine, and tyrosine as substrates were 6.7, 0.45, 4.96, and 0.02 s−1, respectively. Therefore, aspartic acid, fumaric acid, phenylalanine, and tyrosine are bona fide substrates for LpAAL enzyme

The skin hydration and anti-inflammatory potential of zerumbone, a natural sesquiterpene of Zingiber zerumbet, enhanced Src/ERK-mediated HAS-2/AQP-3 and inhibited NFκB/AP-1 expression in UVB-irradiated human keratinocytes

We assayed skin hydration and anti-inflammatory efficacies of zerumbone (Zer, 2.5–10 μM), a natural sesquiterpene of Zingiber zerumbet, using non– or UVB (30 mJ/cm2)-irradiated keratinocytes (HaCaT). &amp; Zer increased cell viability, upregulated hyaluronic acid, and inhibited ROS generation in UVB-irradiated HaCaT cells. Zer promoted antioxidant Nrf2 nuclear translocation resulting in HO-1 and γ-GCLC expression. Zer promotes skin hyaluronic acid by increasing protein and mRNA expression of HAS-2 and AQP-3 in non– or UVB-irradiated HaCaT cells. Furthermore, Zer increased Src and ERK phosphorylation. Src silencing or ERK inhibitor (PD98059) diminished Zer-mediated skin hydration, as evidenced by decreased HAS-2 and AQP-3 expression. Interestingly, UVB-induced Src/ERK inhibition was reversed by Zer or N-acetylcysteine. Additionally, Zer inhibited inflammatory iNOS, COX-2, and IL-1β expression through NFκB (p65) and AP-1 (c-Jun/c-Fos) pathway in UVB-irradiated HaCaT cells. HaCaT cells treated with Zer enhanced the growth factors PDGF-A, VEGF, and EGFR expressions. Zerumbone might be utilized in cosmetic formulations

Optimization for hydrogen production from methanol partial oxidation over Ni–Cu/Al2O3 catalyst under sprays

In this work, a novel Ni–Cu/Al2O3 catalyst is used to trigger the partial oxidation of methanol (POM) for hydrogen production. This reaction system also employed ultrasonic sprays to aid in dispersing methanol fuel. The prepared catalyst is analyzed by scanning electron microscope (SEM), energy-dispersive X-ray (EDX) spectroscopy, and X-ray diffraction (XRD) to explore the catalyst's surface structure, elemental composition, and physical structure, respectively. The Box-Behnken design (BBD) of response surface methodology (RSM) is utilized for experimental design to achieve process optimization. The operating parameters comprise the O2/C molar ratio (0.5–0.7), preheating temperature (150–250 °C), and weight percent (wt%) of Ni (10–30%) in the catalyst. The results show that methanol conversion is 100% in all the operating conditions, while the reaction temperature for H2 production ranges from 160 to 750 °C, stemming from heat released by POM. The significance and suitability of operating conditions are also analyzed by analysis of variance (ANOVA). It indicates that the highest H2 yield is 2 mol (mol CH3OH)−1, occurring at O2/C = 0.5, preheating temperature = 150 °C, and Ni wt% = 10. Compared with the commercial h-BN-Pt/Al2O3 catalyst, the prepared Ni–Cu/Al2O3 catalysts have higher activity for H2 production. The O2/C ratio is the most influential factor in the H2 yield. Moreover, the interaction of the O2/C ratio and Ni content is sound, reflecting that changing Ni content in the catalyst will affect the trend of H2 yield under each O2/C

Tranexamic acid improves psoriasis-like skin inflammation: Evidence from in vivo and in vitro studies

The chronic disease psoriasis is associated with severe inflammation and abnormal keratinocyte propagation in the skin. Tranexamic acid (TXA), a plasmin inhibitor, is used to cure serious bleeding. We investigated whether TXA ointment mitigated Imiquimod (IMQ)-induced psoriasis-like inflammation. Furthermore, this study investigated the effect of noncytotoxic concentrations of TXA on IL-17-induced human keratinocyte (HaCaT) cells to determine the status of proliferative psoriatic keratinocytes. We found that TXA reduced IMQ-induced psoriasis-like erythema, thickness, scaling, and cumulative scores (erythema plus thickness plus scaling) on the back skin of BALB/c mice. Additionally, TXA decreased ear thickness and suppressed hyperkeratosis, hyperplasia, and inflammation of the ear epidermis in IMQ-induced BALB/c mice. Furthermore, TXA inhibited IMQ-induced splenomegaly in BALB/c mouse models. In IL-17-induced HaCaT cells, TXA inhibited ROS production and IL-8 secretion. Interestingly, TXA suppressed the IL-17-induced NFκB signaling pathway via IKK-mediated IκB degradation. TXA inhibited IL-17-induced activation of the NLRP3 inflammasome through caspase-1 and IL1β expression. TXA inhibited IL-17-induced NLRP3 inflammasome activation by enhancing autophagy, as indicated by LC3-II accumulation, p62/SQSTM1 expression, ATG4B inhibition, and Beclin-1/Bcl-2 dysregulation. Notably, TXA suppressed IL-17-induced Nrf2-mediated keratin 17 expression. N-acetylcysteine pretreatment reversed the effects of TXA on NFκB, NLRP3 inflammasomes, and the Nrf2-mediated keratin 17 pathway in IL-17-induced HaCaT cells. Results further confirmed that in the ear skin of IMQ-induced mice, psoriasis biomarkers such as NLRP3, IL1β, Nrf2, and keratin 17 expression were downregulated by TXA treatment. TXA improves IMQ-induced psoriasis-like inflammation in vivo and psoriatic keratinocytes in vitro. Tranexamic acid is a promising future treatment for psoriasis

Design of an LED Spot Light System with a Projection Distance of 10 km

We designed a spot light system with an illumination range of 10 km. In the designed system, an appropriate white light-emitting diode (LED) was selected according to the exitance and injection power required. Subsequently, through a first-order optical design, the geometry of the lens and reflector was determined using geometrical calculation. Because the central illuminance of the projection spot of the reflector was 2.5 times that of the cover lens, we first considered the fabrication error of the reflector. According to the adjustment of the optimized distance between the white LED and reflector, we modified the design of the cover lens to fit the new location of the white LED. An LED spot light module containing 16 spot light units was used. The module&rsquo;s power injection was only 68.2 W. Because of the excellent performance of the designed system in terms of the divergence angle of the projection beam and maximum luminous intensity, which were 1.6&deg; and 2,840,000 cd, respectively, the projection distance of the LED spot light module was 3.37 Km, according to the ANSI regulation. Finally, a spot light system with nine modules and capable of achieving a projection distance of 10 km was successfully fabricated