Synthesis,structural characterization and luminescent properties of Tb3+-doped AgLaP2O7 phosphors

Silver lanthanum diphosphates doped with terbium, AgLa_1-xTb_xP₂O₇ (x=0%, 1%, 5%, 10%, 15% and 20%), were prepared by solid state reaction at T=500°. The obtained compounds were investigated by means of a multi-methodological approach, involving the Scanning Electron Microscopy (SEM) equipped with energy dispersive X-Ray spectroscopy (EDS) for morphological investigation and semi-quantitative chemical analysis, respectively; powder X-ray diffraction (PXRD) for structural characterization and Rietveld refinement; Fourier Transform InfraRed (FTIR) and Raman spectroscopies for qualitative study. Finally, emission spectra were collected in order to detect the fluorescence properties of the compounds.The unit cell parameters and the space group of all the family members were determined by PXRD data. The compounds crystallize in the orthorhombic Pnma space group, with the AgLaP₂O₇ cell constants equal to: a?=?8.6706(1) Å, b?=?5.3218(1) Å, c?=?12.8839(1) Å and cell volume V?=?594.51(1) ų. A decreasing trend for unit cell parameters was observed at increase of dopant concentration. For the pure phase, the investigation was completed with the structure solution via Direct Methods and Rietveld refinement. The crystal structure consists of compact layers of LaO₉ polyhedra, down the c axis, bridged by P₂O₇ diphosphate groups and by zig-zag chains of AgO₉ polyhedra down b.The FTIR and Raman analysis supports the chemical structure, highlighting the deformation (δPO₃) and stretching (νPO₃) vibration of PO₃ groups, and the characteristic bands of P₂O₇^4- groups attributed to the symmetric and asymmetric stretching (ν_s and ν_as) of P-O-P bridge, respectively.The luminescence properties of Tb³⁺ activating ion in AgLa_1-xTb_xP₂O₇ (x=1%, 5%, 10%, 15% and 20%) were also examined. No concentration quenching of the main ⁵D₄-→⁷F₅ emission, responsible for the well known green emission of Tb³⁺ ion, was observed in the studied concentration range, whereas a concentration quenching of the emission from ⁵D₃ level, due to ⁵D₃^-→⁵D₄ cross relaxation process, was revealed.     

Who blogs? Personality predictors of blogging

The Big Five personality inventory measures personality based on five key traits: neuroticism, extraversion, agreeableness, openness to experience, and conscientiousness [Costa, P. T., Jr., & McCrae, R. R. (1992). Normal personality assessment in clinical practice: The NEO Personality Inventory. Psychological Assessment 4, 5–13]. There is a growing body of evidence indicating that individual differences on the Big Five factors are associated with different types of Internet usage [Amichai-Hamburger, Y., & Ben-Artzi, E. (2003). Loneliness and Internet use. Computers in Human Behavior 19, 71–80; Hamburger, Y. A., & Ben-Artzi, E. (2000). Relationship between extraversion and neuroticism and the different uses of the Internet. Computers in Human Behavior 16, 441–449]. Two studies sought to extend this research to a relatively new online format for expression: blogging. Specifically, we examined whether the different Big Five traits predicted blogging. The results of two studies indicate that people who are high in openness to new experience and high in neuroticism are likely to be bloggers. Additionally, the neuroticism relationship was moderated by gender indicating that women who are high in neuroticism are more likely to be bloggers as compared to those low in neuroticism whereas there was no difference for men. These results indicate that personality factors impact the likelihood of being a blogger and have implications for understanding who blogs.     

Analytical Solutions for Stress Intensity Factor,T-Stress and Weight Function for the Edge-Cracked Half-Space

An analytical solution for the linear-elastic problem of an edge-cracked semi-infinite body was given already in 1957. For the numerical evaluation of this solution an iteration procedure had to be applied. This might be the reason why the related analysis was not commonly used. By means of powerful mathematical tools developed in the last years it is now possible to evaluate highly-precise stress intensity factors, T-stress terms, weight functions etc. This will be shown in this paper in detail.     

Hypercube computations on partitioned optical passive stars networks

This paper shows that an n=2/sup k/ processor partitioned optical passive stars (POPS) network with g groups and d processors per group can simulate every bidirectional move of an n processor hypercube using one slot when dg. Moreover, the same POPS network can simulate every monodirectional move of a processor hypercube using one slot when d=g. All these results are shown to be optimal. Our simulations improve on the literature whenever d/spl ne/g and directly yield several important consequences. For example, as a direct consequence of our simulations, a POPS network, n=dg and d相似文献   

The MTCY428.08 gene of Mycobacterium tuberculosis codes for NAD+ synthetase

The product of the MTCY428.08 gene of Mycobacterium tuberculosis shows sequence homology with several NAD+ synthetases. The MTCY428.08 gene was cloned into the expression vectors pGEX-4T-1 and pET-15b. Expression in Escherichia coli led to overproduction of glutathione S-transferase fused and His6-tagged gene products, which were enzymatically assayed for NAD synthetase activity. Our results demonstrate that the MTCY428.08 gene of M. tuberculosis is the structural gene for NAD+ synthetase.     

Effects of chemical composition on nanocrystallization kinetics, microstructure and magnetic properties of finemet-type amorphous alloys

In this study, the kinetics of nanocrystallization of amorphous Fe_73.5Si_13.5B₉Nb₃Cu₁ (F1) and Fe₇₇Si₁₁B₉Nb_2.4Cu_0.6 (F2) alloys is investigated. The microstructure and magnetic properties of the nanocrystalline alloys are compared. The crystallization temperature of F2 alloy is shifted towards lower temperatures with respect to F1. Thus, the crystalline volume fraction and the crystalline grain size at specific annealing temperature for the F2 alloy are higher than for the F1 alloy, accounting for the higher coercive force of F2 alloy with respect to the one of F1 alloy. According to isoconversional methods, the activation energy for crystallization is variable as a function of transformed fraction because of the continuous changes in chemical composition during the transformation. Mean values of 350 and 290 kJ/mol are obtained for F1 and F2, respectively. Microstructural observations confirm that minor changes in chemical composition affect the kinetics and final microstructure of the nanocrystalline alloy, that determine the observed magnetic properties.     

Ultramicronized Palmitoylethanolamide in the Management of Sepsis-Induced Coagulopathy and Disseminated Intravascular Coagulation

Disseminated intravascular coagulation (DIC) is a severe condition characterized by the systemic formation of microthrombi complicated with bleeding tendency and organ dysfunction. In the last years, it represents one of the most frequent consequences of coronavirus disease 2019 (COVID-19). The pathogenesis of DIC is complex, with cross-talk between the coagulant and inflammatory pathways. The objective of this study is to investigate the anti-inflammatory action of ultramicronized palmitoylethanolamide (um-PEA) in a lipopolysaccharide (LPS)-induced DIC model in rats. Experimental DIC was induced by continual infusion of LPS (30 mg/kg) for 4 h through the tail vein. Um-PEA (30 mg/kg) was given orally 30 min before and 1 h after the start of intravenous infusion of LPS. Results showed that um-PEA reduced alteration of coagulation markers, as well as proinflammatory cytokine release in plasma and lung samples, induced by LPS infusion. Furthermore, um-PEA also has the effect of preventing the formation of fibrin deposition and lung damage. Moreover, um-PEA was able to reduce the number of mast cells (MCs) and the release of its serine proteases, which are also necessary for SARS-CoV-2 infection. These results suggest that um-PEA could be considered as a potential therapeutic approach in the management of DIC and in clinical implications associated to coagulopathy and lung dysfunction, such as COVID-19.     

Epigallocatechin-3-Gallate Modulates Postoperative Pain by Regulating Biochemical and Molecular Pathways

Treating postoperative (PO) pain is a clinical challenge. Inadequate PO pain management can lead to worse outcomes, for example chronic post-surgical pain. Therefore, acquiring new information on the PO pain mechanism would increase the therapeutic options available. In this paper, we evaluated the role of a natural substance, epigallocatechin-3-gallate (EGCG), on pain and neuroinflammation induced by a surgical procedure in an animal model of PO pain. We performed an incision of the hind paw and EGCG was administered for five days. Mechanical allodynia, thermal hyperalgesia, and motor dysfunction were assessed 24 h, and three and five days after surgery. At the same time points, animals were sacrificed, and sera and lumbar spinal cord tissues were harvested for molecular analysis. EGCG administration significantly alleviated hyperalgesia and allodynia, and reduced motor disfunction. From the molecular point of view, EGCG reduced the activation of the WNT pathway, reducing WNT3a, cysteine-rich domain frizzled (FZ)1 and FZ8 expressions, and both cytosolic and nuclear β-catenin expression, and the noncanonical β-catenin–independent signaling pathways, reducing the activation of the NMDA receptor subtype NR2B (pNR2B), pPKC and cAMP response element-binding protein (pCREB) expressions at all time points. Additionally, EGCG reduced spinal astrocytes and microglia activation, cytokines overexpression and nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB) pathway, downregulating inducible nitric oxide synthase (iNOS) activation, cyclooxygenase 2 (COX-2) expression, and prostaglandin E2 (PGE2) levels. Thus, EGCG administration managing the WNT/β-catenin signaling pathways modulates PO pain related neurochemical and inflammatory alterations.