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Abstract: The inhibition of cyclooxygenase enzymes plays an important role in the treatment of inflammatory diseases. N-Hydroxy-4-(5-methyl-3-phenylisoxazol-4-yl)benzenesulfonamide (3)—a primary metabolite of the highly selective COX-2 inhibitor valdecoxib—was synthesized and stabilized as its monohydrate (3a·H2O). The anti-inflammatory properties of 3a·H2O were investigated in carrageenan-induced edema and in acute and chronic pain models. Based on our biological investigation, we conclude that N-hydroxy-valdecoxib 3a is an active metabolite of valdecoxib. [Copyright &y& Elsevier]

Tin (Sn) -bentonite was prepared by ion exchange method from Ca-bentonite. For the ion exchange process, tin-chloride (SnCl 2) solution was prepared from metallic tin, and the tin concentration was determined by Microwave Plasma Atomic Emission Spectroscopy (MP-AES). Sn-bentonite was characterized by X-ray fluorescence spectrometry (XRF), X-ray powder diffraction (XRPD), X-ray photoelectron spectroscopy (XPS) and 119Sn as well as iron-57 (57Fe) Mössbauer spectroscopy. 119Sn Mössbauer spectroscopy and XPS undoubtedly revealed both Sn+2 and Sn+4 ions in Sn-bentonite. SnII was attributed to be incorporated into the interlayer space while SnIV located partly in the octahedral position and in the interlayer space of montmorillonite. The removal of radioactive pertechnetate anion (99mTcO 4 -) was studied on Sn-bentonite in aqueous and artificial urine media. Based on the measurement results, 99mTcO 4 - ion can be removed, in case of aqueous media, the equilibrium is reached after 5 mins (x = 99.9 ± 0.01%, k = 4.2 ± 0.83 1/min) (Buzetzky et al., 2019), while in the case of urine media the equilibrium is reached after 30 mins (x = 59.1% ± 2.7, k = 0.18 ± 0.05 1/min). Pertechnetate anoin sorption on tin-bentonite is a (Sn(II/IV)-TcO 4 -) redox reaction. Thus, Sn-bentonite can be a suitable sorbent for radioactive waste management. [Display omitted] [ABSTRACT FROM AUTHOR]

Grain boundary (GB) diffusion of Si in polycrystalline Cu film was studied in the temperature range of 403–453 K, in the C-type kinetic regime. The amorphous Si layer (80 nm) and polycrystalline Cu layer (40 nm) were successively deposited by magnetron sputtering at room temperature onto a Si (111) wafer. Appearance of Si atoms on the copper surface due to GB diffusion through the copper layer was detected by low energy ion scattering spectroscopy with high sensitivity. The depth distribution of Si in Cu grain boundaries was revealed by secondary neutral mass spectrometry. Surface morphology of Cu films was investigated by scanning tunneling microscopy. Identification of Si chemical bonds on the surface layer was made by X-ray photoelectron spectroscopy. GB diffusion coefficients were estimated by the relation used for calculation of diffusant distribution from a constant source in assumption that the diffusion path equals to the film thickness at the moment of appearing Si atoms on the Cu surface. At 453 K we estimated the surface segregation factor and detected formation of Cu–O–Si atomic bonds on the Cu film surface. • Nanoscale grain boundary diffusion of silicon. • Nanoscale depth profile analysis. • Application of low energy ion scattering for study of nanoscale diffusion mechanisms. [ABSTRACT FROM AUTHOR]

Mitochondria are essential in cellular stress responses. Mitochondrial output to environmental stress is a major factor in metabolic adaptation and is regulated by a complex network of energy and nutrient sensing proteins. Activation of poly(ADP-ribose) polymerases (PARPs) has been known to impair mitochondrial function; however, our view of PARP-mediated mitochondrial dysfunction and injury has only recently fundamentally evolved. In this review, we examine our current understanding of PARP-elicited mitochondrial damage, PARP-mediated signal transduction pathways, transcription factors that interact with PARPs and govern mitochondrial biogenesis, as well as mitochondrial diseases that are mediated by PARPs. With PARP activation emerging as a common underlying mechanism in numerous pathologies, a better understanding the role of various PARPs in mitochondrial regulation may help open new therapeutic avenues. [ABSTRACT FROM AUTHOR]

Abstract Veneering ceramics should be strongly bonded to zirconia core in order to achieve successfully long-term clinical practice. Indeed, to pursue the high zirconia core–veneering ceramic bonding is still a concerned issue. In this regard, this study was to treat zirconia surface using a 3 wt% Si 3 N 4 solution in 4 M NaOH and to investigate the effect of soaking time (5, 10, and 20 days) on the surface properties of zirconia and shear bond strength between zirconia and veneering ceramics. The residual veneering ceramics on zirconia surfaces and failure modes were also examined after fracture. The results showed that the phase composition of zirconia before and after surface modification was not changed. The elemental mapping and depth profiling consistently revealed the soaking-time-dependent Si content on the zirconia surface. The surface roughness of zirconia was significantly (P < 0.05) increased with the increasing soaking time. When zirconia was treated for 10 days, the shear bond strength value of 27.4 MPa was significantly (P < 0.05) higher than the control (18.6 MPa), associated with greater remaining amounts of veneering ceramics on the zirconia surface. The failure mode of the treated zirconia was almost the mixed failure. On the basis of the data, surface modification using Si 3 N 4 in NaOH solution for zirconia core could be a simple and effective method for enhancing the veneering ceramic–zirconia bonding. [ABSTRACT FROM AUTHOR]

Abstract: Poly(ADP-ribose) polymerase-2 (PARP-2) is acknowledged as a DNA repair enzyme. However, recent investigations have attributed unique roles to PARP-2 in metabolic regulation in the liver. We assessed changes in hepatic lipid homeostasis upon the deletion of PARP-2 and found that cholesterol levels were higher in PARP-2−/− mice as compared to wild-type littermates. To uncover the molecular background, we analyzed changes in steady-state mRNA levels upon the knockdown of PARP-2 in HepG2 cells and in murine liver that revealed higher expression of sterol-regulatory element binding protein (SREBP)-1 dependent genes. We demonstrated that PARP-2 is a suppressor of the SREBP1 promoter, and the suppression of the SREBP1 gene depends on the enzymatic activation of PARP-2. Consequently, the knockdown of PARP-2 enhances SREBP1 expression that in turn induces the genes driven by SREBP1 culminating in higher hepatic cholesterol content. We did not detect hypercholesterolemia, higher fecal cholesterol content or increase in serum LDL, although serum HDL levels decreased in the PARP-2−/− mice. In cells and mice where PARP-2 was deleted we observed decreased ABCA1 mRNA and protein expression that is probably linked to lower HDL levels. In our current study we show that PARP-2 impacts on hepatic and systemic cholesterol homeostasis. Furthermore, the depletion of PARP-2 leads to lower HDL levels which represent a risk factor to cardiovascular diseases. [Copyright &y& Elsevier]

• Dependence of effective minority carrier lifetime on surface contaminations. • Controlled ppb-level contamination of silicon wafer surfaces. • Low energy LA-ICP-MS method to measure low-level surface metal contaminations. • Surface mapping of ppb-level Cu contaminations. Contamination of silicon semiconductor cells strongly influences their working properties, such as minority carrier lifetime. During manufacture, i.e. cutting off the silicon ingot, the entry of metal contaminants into the silicon needs to be avoided since it decreases the performance of solar cells. To study this effect, controlled contaminations were performed by immersing silicon wafers in dilute HCl-based (pH = 1.3) solutions, containing precisely defined amounts of metal concentrations of 30, 100, 300, and 1000 ppb. The two most common and most damaging transient metals, the iron and copper, were tested. Determination of surface contaminations was carried out by two different methods: Total Reflection X-ray Fluorescence (TXRF) measurements and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). The minority carrier lifetime was checked by photoluminescence (PL) measurements. The LA-ICP-MS method was proved to be an effective arrangement for direct determination of ppb-level surface impurities and their penetration depths. The results received by TXRF and LA-ICP-MS were compared. The advantage of LA-ICP-MS was that in addition to a simple contamination level determination it could be used to acquire the total surface map of contamination. [ABSTRACT FROM AUTHOR]