[en] Unicellular cyanobacterium Synechocystis 6803 showed appreciable resistance to ⁶⁰CO γ-Radiation with a D₁₀ (dose required for one log cycle reduction in cell number) value of - 800 Gy. Differential RNA sequencing (dRNA-seq) of the cells after exposure to ~ 550 Gy (LD₅₀) of these radiation showed significant changes in transcriptional status of several genes especially upregulation of the genes on the mega-plasmid such as sll6053, sll6054, sll6055, slr6056 indicating a possible role of these essential genomic elements in providing stress tolerance. (author)

[en] Founded in 1984, the CANDU Owners Group (COG) is the preeminent organization providing collaborative R&D and information sharing to allow our Members globally to achieve operational excellence. This presentation will start with a brief overview of COG and our role in driving innovation across the industry. The strategic trends and drivers for the industry leading us into the future will be discussed and linked to COG's mandate to maintain performance excellence at the sites, support R&D for new technologies, and ensure a sustainable industry through an industry R&D program and pipeline of subject matter experts. Examples of key areas of innovation that are being pursued jointly by the CANDU owners to sustain the current fleet for 40+ years of operation, will be discussed, including AI, machine learning, and plant modernization. The presentation will then speak to leveraging the COG Collaboration Model for the future of the industry and support to new nuclear builds, as well as capacity building. COG is positioned to work together with the industry to build a strong future where around the world, our fleet of reactors is providing clean and reliable energy. (author)

[en] The aim of this study was to evaluate the effects of in vivo and in vitro treatments with selective estrogen receptor modulator (SERM), tamoxifen on testicular functions. The testis treated with tamoxifen, in vivo or in vitro, showed dose-dependent regressive changes in spermatogenesis. This study showed that the decreased estrogenic effect due to tamoxifen may be directly responsible for decreased testicular expression of aromatase, which in turn may be responsible for decreased synthesis of estradiol in the testis. The decreased endogenous estradiol through cAMP-CREB signaling mechanism may decline germ cells proliferation (PCNA) and survival (Bcl2). The tamoxifen-induced decreased estrogenic effect may also be responsible for increased expression of testicular NOS and consequently increased production of NO, which may cause increased germ cells apoptosis (Caspase-3) and impaired spermatogenesis. Both in vivo and in vitro studies showed the inhibitory effect on testicular steroidogenic factors. Thus, tamoxifen inhibits testicular spermatogenesis and steroidogenesis either directly acting on testis or indirectly through gonadotropin release. - Highlights: •Treatment of tamoxifen, in vivo or in vitro, caused dose-dependent regressive changes in spermatogenesis. •The tamoxifen induced decreased estradiol suppresses germ cells proliferation and survival via cAMP-CREB signaling. • The tamoxifen-induced decreased estrogen may increase production of NO by increasing expression of iNOS.

[en] Highlights: • Sol–gel process is used to obtain spherical nanocrystallites of SiO_2:RE_2O_3 [RE = Y, Gd] powder. • Effect of four steps annealing is studied on micro strain, nanocrystallite size and dislocation density. • Optical properties are examined by absorption spectra and PL. • SiO_2:RE_2O_3 [RE = Y, Gd] binary oxides are promising materials for high temperature structural applications. - Abstract: SiO_2:RE_2O_3 [RE = Y, Gd] powder were prepared by wet chemical technique and the prepared binary oxides annealed at 500 °C and 900 °C. The crystalline structure, phase transformation, and surface morphologies of as-prepared and annealed samples were investigated by XRD and TEM. The normal transmission was measured using FTIR spectroscopy. Optical properties have been studied with UV–Vis spectroscopy and PL study. XRD results shows that the as prepared samples of SiO_2:RE_2O_3 [RE = Y, Gd] powder has mixed phases of RE(NO_3)_3 and Si(OH)_3. However, cubic rare earth oxide phase alone is found for annealed samples. The strain values are calculated from W–H plot for annealed samples. TEM micrograph shows that the samples are composed of individual spherical nanocrystallites at 500 °C and aggregated nanocrystallites at 900 °C. From the UV–Vis spectra, it is found that the position of the absorption peak is shifted toward the higher wavelength side when annealing temperature is increased. In the PL spectra, the broad emission bands are observed between 570–600 nm and the presence of O–Si–O (silica) and metal oxide is confirmed by FTIR spectra

[en] Planar chromatography of thirty six metal ions on titanium(IV) phosphate, titanium(IV) tungstate and titanium(IV) molybdate impregnated papers in DMSO-HNO₃ mobile phases has been carried out. The ion-exchange capacity of papers is determined and the effects of solvent composition, impregnation and pH on R_F values are studied. For K⁺, Rb⁺ and Cs⁺, R_F = KC^1/2, where C is the nitric acid concentration. The movement of ions is explained on the basis of ion-exchange, adsorption and precipitation. Alberti and Torracca's view for the prediction of elution sequence from R_F values has been checked. The sequence of adsorption of ions follows the order : titanium(IV) molybdate > titanium(IV) tungstate > titanium(IV) phosphate. Some of the analytically important separations are reported. (author)

[en] A complex impedance spectroscopy procedure was utilized to examine the impedance and modulus of (Na_0.5Bi_0.5TiO₃) _(1−x) (BaZrO₃) _x (x = 0.00, 0.03, 0.05 and 0.07) solid solution. The microstructural examinations demonstrate that BaZrO₃ acts as a grain development inhibitor. The imaginary part of the impedance plot shows the presence of non-Debye type grain and grain boundary relaxation. The activation energy obtained from impedance and modulus plots was found to increase with an increase in BaZrO₃ content. The Cole–Cole investigation reveals a colossal augmentation in the grain boundary resistance with BaZrO₃ content. However the grain resistance was observed to be almost the same for all the compositions. These outcomes are clarified on the premise of grain boundary-space charge impact and grain-size. (paper)

[en] The present investigation deals with the synthesis of Nd³⁺ doped Y₂O₃:SiO₂ nanopowder around moderate annealing temperatures (450 °C & 850 °C) using sol gel technique. The X-ray diffraction technique was used for phase identification, structural analysis and grain size determination. FTIR spectra of the prepared powder were taken at room temperature in the range 400–4000 cm⁻¹. The morphology of nanoparticles and particle size was confirmed by Transmission Electron Microscope. From structural investigations, initial development of crystalline phase of yttium oxide was obtained in sample S2 annealed at 450 °C. While in sample S3 due to high annealing temperature (850 °C), agglomeration occurred. In this agglomerated sample temperature quenching results thus suppress the luminescence. Therefore, we have reported the optical investigations of sample S2 only. It is also demonstrated that the addition of SiO₂ as sintering agent could improve both the optical and structural properties. The optical absorption spectrum has been observed in the 200–600 nm range. The absorption spectrum of Nd³⁺ doped Y₂O₃-SiO₂ powder depicts absorption edge in ultra-violet region (310 nm) with prominent peaks of neodymium ion (808 nm) in IR region. The band edge absorption wavelength has been used to estimate the band-gap energy of the prepared nanocomposite by Tauc's plot. The emission spectrum has been obtained using two different excitation wavelength (λ_ex = 310 & 808 nm) in UV and NIR regions, respectively. Using λ_ex = 310 nm, strong emission bands have observed in 500–600 nm correspond to Si-O/Y-O or may be due to composite formation. However, the photoluminescence emission corresponding to λ_ex = 808 nm have been centered at 890, 1042 and 1275 nm was attributed to neodymium ion. The structural and optical investigations of Nd³⁺ doped Y₂O₃:SiO₂ is of basic importance for better utilization of such nanopowder in the fabrication of photonic devices, catalytic systems, solid state lasers, opto-and micro-electronics, nanophosphours and optical fiber amplifiers etc. - Highlights: • Sol-gel process is used to obtain Nd³⁺:Y₂O₃-SiO₂ powder at 450 °C temperature. • Effect of annealing is studied on structural and optical evolutions of nanopowder. • Uv–vis spectrum obtained in 300–810 nm range which has Nd ion peaks (808 nm). • PL emission at λ_ex = 310 nm is found due to host ion and defects present at surface. • Emission at λ_ex = 808 nm is attributed to specific Nd ion in 850–1300 nm regions.

[en] Dielectric and phase transition studies of (1−x) Na_0.5Bi_0.5TiO₃-xBaZrO₃ (x = 0.00, 0.01, 0.03, 0.05 and 0.07) solid solution were carried out in the temperature range 0 °C to 475 °C. The dielectric constant values at room temperature as well as at Curie temperature decreases gradually up to x = 0.03, thereafter, a sharp increase in its value is observed for x = 0.05, and 0.07. The loss tangent was found to increase with BaZrO₃ content at high temperature (>400 °C) and low frequency (<10 kHz). The increase of BaZrO₃ content lowers the Curie temperature, tetragonal-to-rhombohedral transition temperature and depolarization temperature. The temperature range of coexistence for the rhombohedral and the tetragonal phases is independent on the BaZrO₃ content. The results are explained on the basis of reduction in the polarizability, augmentation of defect concentration and the emergence of tetragonal phase with the addition of BaZrO₃ in NBT. (paper)

[en] Highlights: •An algorithm combining clinical data and radiology features of hypervascular mediastinal masses is proposed to determine further evaluation and subsequently guide treatment. •Characteristic features and known association with syndromes and genetic mutations assists in achieving a diagnosis. •MRI and functional imaging can be very helpful in the evaluation of hypervascular mediastinal masses. •Identification of hypervascularity within mediastinal masses should alert the radiologist and clinician and an attempt should be made to preferably avoid percutaneous CT guided biopsies and attempt tissue sampling surgically with better control of post procedure hemorrhage. -- Abstract: Hypervascular mediastinal masses are a distinct group of rare diseases that include a subset of benign and malignant entities. Characteristic features and known association with syndromes and genetic mutations assist in achieving a diagnosis. Imaging allows an understanding of the vascularity of the lesion and should alert the radiologist and clinician to potential hemorrhagic complications and avoid percutaneous CT guided biopsies. In such cases, pre-procedure embolization and surgical biopsy maybe considered for better control of post procedure hemorrhage. The purpose of this article is to describe and illustrate the clinical features and radiologic spectrum of hypervascular mediastinal masses, and discuss the associated clinical and genetic syndromes. We will present an imaging algorithm to determine further evaluation and subsequently guide treatment

[en] The overall goal of this research was to further develop and improve an existing skin diffusion model by experimentally confirming the predicted absorption rates of topically-applied volatile organic compounds (VOCs) based on their physicochemical properties, the skin surface temperature, and the wind velocity. In vitro human skin permeation of two hydrophilic solvents (acetone and ethanol) and two lipophilic solvents (benzene and 1,2-dichloroethane) was studied in Franz cells placed in a fume hood. Four doses of each "1"4C-radiolabed compound were tested — 5, 10, 20, and 40 μL cm"−"2, corresponding to specific doses ranging in mass from 5.0 to 63 mg cm"−"2. The maximum percentage of radiolabel absorbed into the receptor solutions for all test conditions was 0.3%. Although the absolute absorption of each solvent increased with dose, percentage absorption decreased. This decrease was consistent with the concept of a stratum corneum deposition region, which traps small amounts of solvent in the upper skin layers, decreasing the evaporation rate. The diffusion model satisfactorily described the cumulative absorption of ethanol; however, values for the other VOCs were underpredicted in a manner related to their ability to disrupt or solubilize skin lipids. In order to more closely describe the permeation data, significant increases in the stratum corneum/water partition coefficients, K_s_c, and modest changes to the diffusion coefficients, D_s_c, were required. The analysis provided strong evidence for both skin swelling and barrier disruption by VOCs, even by the minute amounts absorbed under these in vitro test conditions. - Highlights: • Human skin absorption of small doses of VOCs was measured in vitro in a fume hood. • The VOCs tested were ethanol, acetone, benzene and 1,2-dichloroethane. • Fraction of dose absorbed for all compounds at all doses tested was less than 0.3%. • The more aggressive VOCs absorbed at higher levels than diffusion model predictions. • We conclude that even small exposures to VOCs temporarily alter skin permeability