Growth of large La2−xSrxCuO4 single crystals using tilting-mirror-type infrared heating image furnace

Large single crystals of La_2−xSr_xCuO₄ (LSCO) high-T_c superconductors were grown by the infrared heating floating zone (IR-FZ) method using a tilting-mirror-type image furnace. The maximum diameter of the LSCO crystals increased to 10 mm in the tilting-mirror-type image furnace from 6 mm in the conventional image furnace. CuO rich feeds were required for the crystal growth using the tilting-mirror-type image furnace to compensate for the lack of CuO caused by the significant evaporation of CuO during the growth. The evaporation of CuO was affected by the tilting angle of the mirrors of the image furnace and by feed diameter. The optimized growth conditions were as follows: mirror tilting angle, 20°; feed diameter, 10 mm∅; and feed composition 50.7 mol% CuO.     

Nephroprotective Effects of Alhagi camelorum against Cisplatin-Induced Nephrotoxicity in Albino Wistar Rats

Alhagi camelorum (AC) is an old plant with a significant therapeutic value throughout Africa, Asia, and Latin America. The overuse of cisplatin (Cis > 50 mg/m²) is associated with observed nephrotoxicity, ototoxicity, gastrotoxicity, myelosuppression, and allergic reactions. Remedial measures are needed for the protection of nephrotoxicity against cisplatin. Thus, we investigated the nephroprotective effects of AC plant extract to prevent cisplatin-induced nephrotoxicity in albino Wistar rats. The presence of polyphenols, phenolic compounds, tannins, and saponins was revealed during phytochemical investigation, and a significantly intense antioxidant activity was recorded. There were no toxicological symptoms in the treated rats, and no anatomical, physiological, or histological abnormalities were found compared to the control rats. The results of correcting cisplatin-induced nephrotoxicity revealed that the extract has a significant ability to treat kidney damage, with most parameters returning to normal after only three weeks of therapy. It is concluded that co-administration of cisplatin with AC extract showed exceptional nephroprotective effects at a dose of 600 mg/kg for Cis-induced nephrotoxicity.     

High energy neutrinos from gamma-ray bursts with precursor supernovae

The high energy neutrino signature from proton-proton and photo-meson interactions in a supernova remnant shell ejected prior to a gamma-ray burst provides a test for the precursor supernova, or supranova, model of gamma-ray bursts. Protons in the supernova remnant shell and photons entrapped from a supernova explosion or a pulsar wind from a fast-rotating neutron star remnant provide ample targets for protons escaping the internal shocks of the gamma-ray burst to interact and produce high energy neutrinos. We calculate the expected neutrino fluxes, which can be detected by current and future experiments.     

Synthesis of 2-Aminopyrimidine Derivatives and Their Evaluation as β-Glucuronidase Inhibitors: In Vitro and In Silico Studies

Currently the discovery and development of potent β-glucuronidase inhibitors is an active area of research due to the observation that increased activity of this enzyme is associated with many pathological conditions, such as colon cancer, renal diseases, and infections of the urinary tract. In this study, twenty-seven 2-aminopyrimidine derivatives 1–27 were synthesized by fusion of 2-amino-4,6-dichloropyrimidine with a variety of amines in the presence of triethylamine without using any solvent and catalyst, in good to excellent yields. All synthesized compounds were characterized by EI-MS, HREI-MS and NMR spectroscopy. Compounds 1–27 were then evaluated for their β-glucuronidase inhibitory activity, and among them, compound 24 (IC₅₀ = 2.8 ± 0.10 µM) showed an activity much superior to standard D-saccharic acid 1,4-lactone (IC₅₀ = 45.75 ± 2.16 µM). To predict the binding mode of the substrate and β-glucuronidase, in silico study was performed. Conclusively, this study has identified a potent β-glucuronidase inhibitor that deserves to be further studied for the development of pharmaceutical products.     

Synthesis and Characterization of High-Quality Polycrystalline Sample NiV2O6 by Solid-State Reaction Technique

Physics of the Solid State - Employing the solid-state reaction route, good quality polycrystalline sample NiV2O6 is prepared that has effective application in rechargeable Li-ion batteries. The...     

Modified signed-digit trinary addition using synthetic wavelet filter

The modified signed-digit (MSD) number system has been a topic of interest as it allows for parallel carry-free addition of two numbers for digital optical computing. In this paper, harmonic wavelet joint transform (HWJT)-based correlation technique is introduced for optical implementation of MSD trinary adder implementation. The realization of the carry-propagation-free addition of MSD trinary numerals is demonstrated using synthetic HWJT correlator model. It is also shown that the proposed synthetic wavelet filter-based correlator shows high performance in logic processing. Simulation results are presented to validate the performance of the proposed technique.     

Synthesis and characterization of room temperature sol–gel-assisted transparent tin-doped magnesium oxide nanoparticles’ protective coating

Journal of Sol-Gel Science and Technology - Using in-situ sol–gel processing, Sn-doped MgO2 nanofilm has been fabricated by spin-coating technique. Cracked and uneven distribution of...     

Gamma-ray bursts in the swift-Fermi era

Gamma-ray bursts （GRBs） are among the most violent occurrences in the universe. They are pow- erful explosions, visible to high redshift, and thought to be the signature of black hole birth. They are highly luminous events and provide excellent probes of the distant universe. GRB research has greatly advanced over the past 10 years with the results from Swift, Fermi and an active followup community. In this review we survey the interplay between these recent observations and the theoretical models of the prompt GRB emission and the subsequent afterglows.     

Engineering of Cysteine Residues Leads to Improved Production of a Human Dipeptidase Enzyme in <Emphasis Type="Italic">E. coli</Emphasis>

Low yields, poor folding efficiencies and improper disulfide bridge formation limit large-scale production of cysteine-rich proteins in Escherichia coli. Human renal dipeptidase (MDP), the only human β-lactamase known to date, is a homodimeric enzyme, which contains six cysteine residues per monomer. It hydrolyses penem and carbapenem β-lactam antibiotics and can cleave dipeptides containing amino acids in both d- and l-configurations. In this study, MDP accumulated in inactive form in high molecular weight, disulfide-linked aggregates when produced in the E. coli periplasm. Mutagenesis of Cys361 that mediates dimer formation and Cys93 that is unpaired in the native MDP led to production of soluble recombinant enzyme, with no change in activity compared with the wild-type enzyme. The removal of unpaired or structurally inessential cysteine residues in this manner may allow functional production of many multiply disulfide-linked recombinant proteins in E. coli.