Investigation of photocatalytic performance of titania based hybrid nanocomposite structure for dilapidation of organic contaminants.

This research paper attempt to provide the photocatalytic performance of nitrogen ion (N+) entrenched anodized Ti with hydroxyapatite hybrid nano-sctructure meant for dilapidation of organic contaminant from the environment. The N+ was entrenched at 70 keV with varying doses (1 × 1016, 5 × 1016, 1 × 1017 and 2.5 × 1017 N+/cm2) into anodized Ti surface. Functional groups, phase structure, topographic and morphologic characterizations of the synthesized hybrid nano-sctructure were analyzed using Infra Red Spectroscopy, X-ray diffraction and Microscopic techniques, respectively. Wettability of the specimens was found out using contact angle measurements. The anodized Ti specimens without N+ have exhibited less surface energy than the specimens with N+. Porous shell gets smoothened after the entrenchment of N+. Compared to all the doses of nitrogen implantation, better performance was observed for 5 × 1016 N+/cm2 dose. Moreover, the samples with N+ showed better charge transfer resistance indicating enhanced photocatalytic performance of N+ entrenched titania than other samples.

Comparison of Simarouba glauca seed shell carbons for enhanced direct red 12B dye adsorption: Adsorption isotherm and kinetic studies.

This study aims at the transformation of the waste lignocellulosic biomass, Simarouba glauca seed shell obtained from biofuel industries, into a value-added adsorbent for the removal of dyes from aqueous media. The basic dye direct red (DR) 12B was adsorbed using chemically (ZnCl2) and thermally activated Simarouba seed shell carbon (ZASRC and SRC, respectively). Dye removal in batch mode was studied by evaluating adsorbent dosage, contact time, pH, adsorption isotherm and kinetics. Enhanced adsorption of DR12B was attained within 80 min at pH 5 with the maximal adsorption capacity (Q0) of 17.48 and 64.94 mg g-1, for SRC and ZASRC, respectively. Further, the dye removal followed Freundlich isotherm model and pseudo second-order kinetics. The mean-free energy of adsorption demonstrated that dye adsorption onto ZASRC occurs through ion-exchange. Thus, ZASRC can be safely and easily applied for the removal of direct red 12B from aqueous solutions.

Characterization of active lead molecules from Lissocarinus orbicularis with potential antimicrobial resistance inhibition properties.

BACKGROUND: Marine organisms are the potential contributors of novel bioactive molecules. Nevertheless, their biodiversity and the versatility of bioactive metabolites have not been fully explored. Hence, the aim of the present study was to investigate the potentials of gut associated bacteria from a marine crab for the production of novel antibacterial compound. METHODS: Aerobic gut autochthonous bacteria isolated from marine crab (Lissocarinus orbicularis) collected from Pazhayar coastal area in Nagapattinam district of Tamil Nadu, India were screened for antibacterial activity. Optimization for bacterial growth and antimicrobial compound production, extraction, purification and characterization were studied. RESULTS: In the present study, eight morphologically distinct colonies of L. orbicularis gut associated aerobic bacterial isolates (Iso1-Iso8) on Zobell marine agar plate were selected. Isolates were screened for antimicrobial activity against human bacterial pathogens such as Salmonella paratyphi, Vibrio cholera, Vibrio parahaemolyticus, Aeromonas hydrophila and Listeria monocytogenes. On the basis of screening results, isolate 5 (Iso5) was selected as the most potential strain and identified as Paenibacillus polymyxa using biochemical and 16S rRNA sequencing methods. The sequence data was submitted to NCBI (Gene bank Accession No: MK583465). Optimization of P. polymyxa for growth and antimicrobial compound production revealed incubation period (36 h), agitation (150 rpm), pH 8.0, 35 °C, 2.5% salinity, 2% glucose and 1% yeast extract as carbon and nitrogen sources respectively were the ideal conditions and mass culture was done with these parameters. Antimicrobial compound from the cell free supernatant of mass culture medium was extracted using ethanol. The lowest minimum inhibitory concentration (MIC) of 16 µg/ml was observed against of both V. parahaemolyticus and V. cholerae. GC-MS analysis of the active ethanol fraction showed the presence of different components such as dodecane (96.72%), Tridecane (1.69%), Undecane, 2,6-dimethyl- (1.69%), Tetradecane (1.12%) and Dodecane, 2,6,11-trimethyl- (1.12%). CONCLUSION: The present study showed that the gut associated autochthonous bacteria of marine crabs are one of the potential sources of antibacterial compound. However, further studies are needed for the identification of the antimicrobial compound.

A Novel Metal Nanoparticles-Graphene Nanodisks-Quantum Dots Hybrid-System-Based Spaser.

Active nanoplasmonics have recently led to the emergence of many promising applications. One of them is the spaser (surface plasmons amplification by stimulated emission of radiation) that has been shown to generate coherent and intense fields of selected surface plasmon modes that are strongly localized in the nanoscale. We propose a novel nanospaser composed of a metal nanoparticles-graphene nanodisks hybrid plasmonic system as its resonator and a quantum dots cascade stack as its gain medium. We derive the plasmonic fields induced by pulsed excitation through the use of the effective medium theory. Based on the density matrix approach and by solving the Lindblad quantum master equation, we analyze the ultrafast dynamics of the spaser associated with coherent amplified plasmonic fields. The intensity of the plasmonic field is significantly affected by the width of the metallic contact and the time duration of the laser pulse used to launch the surface plasmons. The proposed nanospaser shows an extremely low spasing threshold and operates in the mid-infrared region that has received much attention due to its wide biomedical, chemical and telecommunication applications.

Impact of Diabetes Mellitus on Human Erythrocytes: Atomic Force Microscopy and Spectral Investigations.

Diabetes mellitus (DM) is a common metabolic disease indicated by high sugar levels in the blood over a prolonged period. When left untreated, it can lead to long-term complications, such as cardiovascular disease, stroke, and diabetic retinopathy or foot ulcers. Approximately 415 million people (about 8.3% of the world's population) had diabetes worldwide in 2015, with 90% of the cases classified as Type 2 DM, which is caused by insulin resistance that arises mostly from being overweight and from a lack of exercise. DM affects every part of the body, including the erythrocytes. The aim of the present report is to gain insight into the damage done to the erythrocytes of patients classified with pre-diabetes and diabetes (plenty are found in the Kingdom of Saudi Arabia, a country where young people encompass a large segment of the population). The study presents results on the morphological analysis of erythrocytes by atomic force microscopy (AFM) and molecular investigations by fluorescence spectroscopy (FS). Our results indicate significant differences (in the morphology, size, and hemolytic end products) between the erythrocytes of diabetic patients (HbA1C, glycated hemoglobin, levels of 8⁻10%) and normal controls. It is well-known that DM and smoking are two major contributory factors for cardiovascular diseases (CVDs), and our observations presented in this study suggest that diabetes plays a relatively less damaging role than smoking for CVD.

Gamma-Irradiation Effects on the Spectral and Amplified Spontaneous Emission (ASE) Properties of Conjugated Polymers in Solution.

In this paper, we investigate the effects of gamma (γ) radiation on the spectral and mplified spontaneous emission (ASE) properties of two conjugated polymers (CPs) viz., poly [2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH⁻PPV) (CPM) and poly{[2-[2',5'-bis(2″-ethylhexyloxy)phenyl]-1,4-phenylenevinylene]-co-[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene]} (BEHP-co-MEH⁻PPV) (BMP) in tetrahydrofuran (THF). Gamma irradiation strongly affected the photophysical properties of these CPs. To explore these changes, gamma radiation, in the range of 2⁻50 kGy, was used to maintain the temperature at 5 °C constant for all doses at a dose rate of 12.67 kGy/h, using a 60Co gamma ray. The ASE profiles of the CPs in THF were obtained under the high power excitation of a Nd:YAG laser (355 nm), pre- and post-radiation. The result revealed a dramatic blue shift of the fluorescence and the ASE spectra after gamma irradiation. This shift in the luminescence and ASE spectra could be a response to the conformational disorders such as gamma irradiation-induced polymer crosslinking, which was verified using Raman spectra, FTIR, and swelling experiments. This could be the first report on the effect of gamma radiation on the ASE properties of conjugated polymers.