Copper nanoparticles differentially target testis of the catfish, Clarias batrachus: in vivo and in vitro study

Present study examined the impact of copper (Cu) as nanoparticle (Cu-NPs) and soluble form (CuSO4) in adult male catfish Clarias batrachus. Following treatment, upregulation of transcripts of several testis-related genes and increased androgen levels were evident. Though profound promotional effect was seen at gene and androgen levels, structural analysis revealed completely different scenario. Histological observations of testis showed disruption of basal lamina, distinct spermatogonium and enlarged spermatocytes in the treated groups. Quite alarmingly, transmission electron microscopic analysis showed damage of testicular lumen with irregular basal lamina and distinctive spermatocytes. In addition, Sertoli cells and erythrocytes exhibited damage after Cu treatments. Cytotoxic effects of Cu in catfish primary testis and TM3 Leydig cells showed cytotoxicity which is correlated well with morphological and flow cytometric analysis. Taken together, the results demonstrated that low dose of Cu/Cu-NPs can be detrimental to catfish testicular recrudescence vis-à-vis reproduction and the toxic effect manifest drastically in in vitro cultures

Effect of Etching on the Optical, Morphological Properties of Ag Thin Films for SERS Active Substrates

Structural, optical, and morphological properties of Ag thin films before and after etching were investigated by using X-ray diffraction, UV-Vis spectrophotometer, and field emission scanning electron microscopy (FESEM). The HNO3 roughened Ag thin films exhibit excellent enhancement features and better stability than pure Ag thin films. Further, the Ag nanostructures are covered with Rhodamine 6G (Rh6G) and then tested with surface enhanced raman spectroscopy (SERS) for active substrates. Etched Ag films were found to exhibit a strong SERS effect and excellent thermal stability. Hence, the present method is found to be useful in the development of plasmon-based analytical devices, especially SERS-based biosensors

Structural, conductivity and dielectric properties of Li

Li2SO4 have been synthesized from lithium sulphate monohydrate by melting at 880 °C and slow cooling. The XRD results indicates that the melt cooled Li2SO4 is crystallized to monoclinic structure. The AC conductivity (σac) and dielectric relaxation (tan δ) have been measured within the temperature range 170–250 °C and frequency range 100 Hz–120 kHz, respectively. The DC conductivities are conveniently extracted from σac (typical values ∼2 × 10−7 and ∼2 × 10−6 S/cm at 200 and 250 °C, respectively) and are fitted to linear Arrhenius plot. The slope of this linear plot leads to an activation energy of 1.10 eV. It is found that the conduction in Li2SO4 is mainly through Li+. Further, we carried out first principles calculations and obtained the structural and bonding properties of Li2SO4. From band structure, Li2SO4 is found to be a wide band gap insulator with a band gap of 6.1 eV. The partial density of states reveals the finite states of Li+ near to Fermi level, which limits its use of full capacity. This indicates a kinetic barrier for Li ions and electrons ambipolar diffusion

Label-free microscopy of mitotic chromosomes using the polarization orthogonality breaking technique

International audienceWe report how a recently developed polarization imaging technique, implementing micro-wave photonics and referred to as orthogonality-breaking (OB) imaging, can be adapted on a classical confocal fluorescence microscope, and is able to provide informative polarization images from a single scan of the cell sample. For instance, the comparison of the images of various cell lines at different cell-cycle stages obtained by OB polarization microscopy and fluorescence confocal images shows that an endogenous polarimetric contrast arizes with this instrument on compacted chromosomes during cell division

Study of coexisting phases in Bi doped La0.67Sr0.33MnO3

We report the remarkable phase separation behavior in La0.67Sr0.33MnO3 doped with Bi3+ ion at La site. The temperature dependent resistivity and magnetization of La0.67-xBixSr0.33MnO3 (x>0) show the presence of phase separation of ferromagnetic metallic and charge ordered antiferromagnetic insulating phases. Markedly, the field dependant magnetization studies of La0.67-xBixSr0.33MnO3 (x=0.3) show the metamagnetic nature of ferromagnetic metallic state implying the competition of coexisting ferromagnetic metallic and charge ordered antiferromagnetic phases. The electron spin resonance and exchange bias studies of La0.67-xBixSr0.33MnO3 (x=0.4 and 0.5) substantiate the coexistence of ferromagnetic clusters in antiferromagnetic matrix. (C) 2016 Elsevier B.V. All rights reserved