Assessment of the Toxic Effect of Hexavalent Chromium on the Hematological Indices in Nile Tilapia, Oreochromis Niloticus

The presence of heavy metals, which are typically released into water bodies as a result of fast industrialization, causes the aquatic environment to become extremely contaminated. Chromium is one of the most common heavy metals in the environment and is used in several types of industries. The effect of sublethal toxicity of hexavalent chromium Cr (VI) on hematological indices of the Nile tilapia, Oreochromis niloticus has been analyzed following exposure of concentration 9.349 mg/L and 18.698 mg/L (10% & 20% of LC50 value) of potassium dichromate (K2Cr2O7) as hexavalent chromium for 7, 15, 30 days. Hematological parameters are the most important indicators of fish health status. The aim of this study was to determine the effect of Cr (VI) toxicity on hematological parameters in O. niloticus. The results show that hemoglobin percentage (Hb%), red blood cell (RBC), mean corpuscular volume (MCV), and platelet count level were significantly (P > 0.05) decreased and the total count of white blood cell (WBC) was significantly (P > 0.05) increased with increasing time of exposure at a concentration of 9.349 mg/L of K2Cr2O7 in the test groups compared to the control group. At the concentration of 18.69 mg/L, Hb%, RBC, MCV, mean corpuscular hemoglobin concentration (MCHC), and platelet count level were significantly (P > 0.05) decreased and the total count of WBC and erythrocyte sedimentation rate (ESR) value were significantly (P > 0.05) increased with the increasing time of exposure in the test groups compared to the control group. To study the R2 value of the linear regression equation, we found that the trend of the chronic toxic effect of hexavalent chromium at 60 and 90 days of both the sublethal concentrations 9.349 mg/L and 18.69 mg/L of K2Cr2O7, where the value of Hb, RBC, packed volume cell (PCV), MCV are found to drastically decreased and the value ESR and WBC are found to drastically increased in the experimental groups compared to the control group. The investigation recommended that the presence of hexavalent chromium in the aquatic medium has a strong impact on the hematological indices in O. niloticus

Functionalization of manganite nanoparticles and their interaction with biologically relevant small ligands: picosecond time-resolved FRET studies

We report molecular functionalization of the promising manganite nanoparticles La0.67Sr0.33MnO3 (LSMO) for their solubilization in aqueous environments. The functionalization of individual NPs with the biocompatible citrate ligand, as confirmed by Fourier transform infrared (FTIR) spectroscopy, reveals that citrates are covalently attached to the surface of the NPs. UV-VIS spectroscopic studies on the citrate functionalized NPs reveals an optical band in the visible region. Uniform size selectivity (2.6 nm) of the functionalization process is confirmed from high resolution transmission electron microscope (HRTEM). In the present study we have used the optical band of the functionalized NPs to monitor their interaction with other biologically important ligands. Forster resonance energy transfer (FRET) of a covalently attached probe 4-nitrophenylanthranilate (NPA) with the capped NPs confirm the attachment of the NPA ligands to the surface functional group (-OH) of the citrate ligand. The FRET of a DNA base mimic, 2-aminopurine (2AP), with the NPs confirms the surface adsorption of 2AP. Our study may find relevance in the study of the interaction of individual manganite NPs with drug/ligand molecules

Facile synthesis of reduced graphene oxide-gold nanohybrid for potential use in industrial waste-water treatment

Here, we report a facile approach, by the photochemical reduction technique, for in situ synthesis of Au-reduced graphene oxide (Au-RGO) nanohybrids, which demonstrate excellent adsorption capacities and recyclability for a broad range of dyes. High-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) data confirm the successful synthesis of Au-RGO nanohybrids. The effect of several experimental parameters (temperature and pH) variation can effectively control the dye adsorption capability. Furthermore, kinetic adsorption data reveal that the adsorption process follows a pseudo second-order model. The negative value of Gibbs free energy (Delta G(0)) confirms spontaneity while the positive enthalpy (Delta H-0) indicates the endothermic nature of the adsorption process. Picosecond resolved fluorescence technique unravels the excited state dynamical processes of dye molecules adsorbed on the Au-RGO surface. Time resolved fluorescence quenching of Rh123 after adsorption on Au-RGO nanohybrids indicates efficient energy transfer from Rh123 to Au nanoparticles. A prototype device has been fabricated using Au-RGO nanohybrids on a syringe filter (pore size: 0.220 mu m) and the experimental data indicate efficient removal of dyes from waste water with high recyclability. The application of this nanohybrid may lead to the development of an efficient reusable adsorbent in portable water purification. GRAPHICS

Efficacy of nano-hydroxyapatite prepared by an aqueous solution combustion technique in healing bone defects of goat

The present study was undertaken to evaluate porous hydroxyapatite (HAp), the powder of which was prepared by a novel aqueous solution combustion technique, as a bone substitute in healing bone defects in vivo, as assessed by radiologic and histopathologic methods, oxytetracycline labeling, and angiogenic features in Bengal goat. Bone defects were created in the diaphysis of the radius and either not filled (group I) or filled with a HAp strut (group II). The radiologic study in group II showed the presence of unabsorbed implants which acted as a scaffold for new bone growth across the defect, and the quality of healing of the bone defect was almost indistinguishable from the control group, in which the defect was more or less similar, although the newly formed bony tissue was more organized when HAp was used. Histologic methods showed complete normal ossification with development of Haversian canals and well-defined osteoblasts at the periphery in group II, whereas the control group had moderate fibro-collagenization and an adequate amount of marrow material, fat cells, and blood vessels. An oxytetracycline labeling study showed moderate activity of new bone formation with crossing-over of new bone trabeculae along with the presence of resorption cavities in group II, whereas in the control group, the process of new bone formation was active from both ends and the defect site appeared as a homogenous non-fluoroscent area. Angiograms of the animals in the control group showed uniform angiogenesis in the defect site with establishment of trans-transplant angiogenesis, whereas in group II there was complete trans-transplant shunting of blood vessel communication. Porous HAp ceramic prepared by an aqueous combustion technique promoted bone formation over the defect, confirming their biologic osteoconductive property

Deposition and characterization of diamond-like nanocomposite coatings grown by plasma enhanced chemical vapour deposition over different substrate materials

Diamond-like nanocomposite (DLN) coatings have been deposited over different substrates used for biomedical applications by plasma-enhanced chemical vapour deposition (PECVD). DLN has an interconnecting network of amorphous hydrogenated carbon and quartz-like oxygenated silicon. Raman spectroscopy, Fourier transform-infra red (FT-IR) spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD) have been used for structural characterization. Typical DLN growth rate is about 1 m/h, measured by stylus profilometer. Due to the presence of quartz-like Si:O in the structure, it is found to have very good adhesive property with all the substrates. The adhesion strength found to be as high as 0 center dot 6 N on SS 316 L steel substrates by scratch testing method. The Young's modulus and hardness have found to be 132 GPa and 14 center dot 4 GPa, respectively. DLN coatings have wear factor in the order of 1 x 10 (-aEuro parts per thousand 7) mm (3) /N-m. This coating has found to be compatible with all important biomedical substrate materials and has successfully been deposited over Co-Cr alloy based knee implant of complex shape

A Rare HBV Subgenotype D4 with Unique Genomic Signatures Identified in North-Eastern India –An Emerging Clinical Challenge?

BACKGROUND/AIMS: HBV has been classified into ten genotypes (A-J) and multiple subgenotypes, some of which strongly influence disease outcome and their distribution also correlate with human migration. HBV infection is highly prevalent in India and its diverse population provides an excellent opportunity to study the distinctiveness of HBV, its evolution and disease biology in variegated ethnic groups. The North-East India, having international frontiers on three sides, is one of the most ethnically and linguistically diverse region of the country. Given the paucity of information on molecular epidemiology of HBV in this region, the study aimed to carry out an in-depth genetic characterization of HBV prevailing in North-East state of Tripura. METHODS: From sera of chronically HBV infected patients biochemical/serological tests, HBV DNA quantification, PCR-amplification, sequencing of PreS/S or full-length HBV genomes were done. HBV genotype/subgenotype determination and sequence variability were assessed by MEGA5-software. The evolutionary divergence times of different HBV subgenotypes were estimated by DNAMLK/PHYLIP program while jpHMM method was used to detect any recombination event in HBV genomes. RESULTS: HBV genotypes D (89.5%), C (6.6%) and A (3.9%) were detected among chronic carriers. While all HBV/A and HBV/C isolates belonged to subgenotype-A1 and C1 respectively, five subgenotypes of HBV/D (D1-D5) were identified including the first detection of rare D4. These non-recombinant Indian D4 (IndD4) formed a distinct phylogenetic clade, had 2.7% nucleotide divergence and recent evolutionary radiation than other global D4. Ten unique amino acids and 9 novel nucleotide substitutions were identified as IndD4 signatures. All IndD4 carried T120 and R129 in ORF-S that may cause immune/vaccine/diagnostic escape and N128 in ORF-P, implicated as compensatory Lamivudine resistance mutation. CONCLUSIONS: IndD4 has potential to undermine vaccination programs or anti-viral therapy and its introduction to North-East India is believed to be linked with the settlement of ancient Tibeto-Burman migrants from East-Asia

Biocontrol of larval mosquitoes by Acilius sulcatus (Coleoptera: Dytiscidae)

<p>Abstract</p> <p>Background</p> <p>Problems associated with resistant mosquitoes and the effects on non-target species by chemicals, evoke a reason to find alternative methods to control mosquitoes, like the use of natural predators. In this regard, aquatic coleopterans have been explored less compared to other insect predators. In the present study, an evaluation of the role of the larvae of <it>Acilius sulcatus </it>Linnaeus 1758 (Coleoptera: Dytiscidae) as predator of mosquito immatures was made in the laboratory. Its efficacy under field condition was also determined to emphasize its potential as bio-control agent of mosquitoes.</p> <p>Methods</p> <p>In the laboratory, the predation potential of the larvae of <it>A. sulcatus </it>was assessed using the larvae of <it>Culex quinquefasciatus </it>Say 1823 (Diptera: Culicidae) as prey at varying predator and prey densities and available space. Under field conditions, the effectiveness of the larvae of <it>A. sulcatus </it>was evaluated through augmentative release in ten cemented tanks hosting immatures of different mosquito species at varying density. The dip density changes in the mosquito immatures were used as indicator for the effectiveness of <it>A. sulcatus </it>larvae.</p> <p>Results</p> <p>A single larva of <it>A. sulcatus </it>consumed on an average 34 IV instar larvae of <it>Cx. quinquefasciatus </it>in a 24 h period. It was observed that feeding rate of <it>A. sulcatus </it>did not differ between the light-on (6 a.m. – 6 p.m.), and dark (6 p.m. – 6 a.m.) phases, but decreased with the volume of water i.e., space availability. The prey consumption of the larvae of <it>A. sulcatus </it>differed significantly (P < 0.05) with different prey, predator and volume combinations, revealed through univariate ANOVA. The field study revealed a significant decrease (p < 0.05) in larval density of different species of mosquitoes after 30 days from the introduction of <it>A. sulcatus </it>larvae, while with the withdrawal, a significant increase (p < 0.05) in larval density was noted indicating the efficacy of <it>A. sulcatus </it>in regulating mosquito immatures. In the control tanks, mean larval density did not differ (p > 0.05) throughout the study period.</p> <p>Conclusion</p> <p>the larvae of the dytiscid beetle <it>A. sulcatus </it>proved to be an efficient predator of mosquito immatures and may be useful in biocontrol of medically important mosquitoes.</p