Activating ZnO nanorods photoanodes in visible light by CdS surface sensitiser

Thin films of c-axis aligned uniform ZnO nanorods (NRs) were fabricated on to fluorine-doped tin oxide-coated soda lime glass substrate by a two-step chemical route. Thereafter ZnO NRs/CdS core shell structures were successfully synthesised by depositing CdS layer on top of vertically aligned ZnO NRs using less hazardous nanocrystal layer deposition technique. The presence of CdS in ZnO NRs/CdS core shell structures was confirmed by energy dispersive X-ray analysis. Examination of structure and morphology of the fabricated films by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) revealed that both films have one-dimensional hexagonal wurtzite structure. Optical properties evaluated from ultraviolet-visible and photoluminescence spectra demonstrated better photo response of ZnO NRs/CdS core shell structure with respect to bare ZnO NR structure. Optical to chemical conversion efficiency of ZnO NRs/CdS photoanode was found to be similar to 1.75 times higher than bare ZnO NRs photoanode in photo electrochemical water splitting under visible light

EVALUATING THE ANTI-MICROBIAL EFFECT OF EUGENOL EXTRACTED FROM OCIMUM SANCTUM

Eugenol is a phytochemical present in herbal and medicinal plants. It possess anti tubercular, anti-inflammatory, anti-mutagenic properties. Commercial or synthesised eugenol is used extensively in the market nowadays. The aim is to evaluate the anti-microbial property of eugenol extracted from both the powder and leaf samples of Ocimum sanctum (tulsi) and to have a comparative analysis of the synthetic eugenol and the naturally extracted eugenol from tulsi leaves. The eugenol is extracted from tulsi leaves by steam distillation. For quantitative analysis of the natural eugenol, HPLC and UV Spectroscopy are performed with commercial eugenol as the reference. While Raman Spectroscopy is performed for qualitative analysis of the constituents of tulsi leaves. Membrane casting is done with eugenol as the core ingredient and porosity of the membrane is checked by SEM. Further microbial assay is performed to evaluate the effect of eugenol. From the results it can be concluded that the eugenol extracted from the powder and fresh leaves of tulsi has anti-microbial effect and the membrane composed of eugenol has the capability to retain the eugenol. Keywords: Ocimum sanctum, eugenol, anti-microbial, membrane,anti-microbial

Histopathological and Immunohistochemical Analysis of Rare Parotid Tumours: A Case Series

Malignant salivary gland tumours are rare representing only 2% of all head and neck malignancies. The most common malignant salivary gland tumour is mucoepidermoid carcinoma followed by adenoid cystic carcinoma while parotid is the most common site. But there are presence of other rare variants with diverse biological feature of maliganacy including Salivary Duct Carcinoma (SDC), basal cell adenocarcinoma, Carcinoma ex Pleomorphic Adenoma (CXPA), polymorphous adenocarcinoma which represent 1-5% of all salivary gland neoplasm. They typically are high-grade carcinomas with presence lymph nodal metastases. Hereby, author report 5 rare cases of parotid gland malignancy detected by histopathological examination along with confirmation by immunohistochemical examination. A 60-year-old and 65-year-old male diagnosed with salivary duct carcinoma of left parotid and right parotid respectively with ipsilateral cervical lymph node involvement but peripheral resection margins were free from tumour invasion. A 50-year-old female diagnosed with basal cell adenocarcinoma of left parotid with lymph node metastasis and resection margin was involved by the tumour. A 60-year-old male presented with recurrent swelling in left parotid region, diagnosed as carcinoma ex pleomorphic adenoma with lymph node involvement in a case of pleomorphic adenoma of parotid, reported previously. A 52-year-old male presented with right-sided parotid region swelling for last six months having Fine Needle Aspiration Cytology (FNAC) report of pleomorphic adenoma. Parotidectomy revealed diagnosis of polymorphous adenocarcinoma while surgical resection margins were free. Surgery is the main mode of treatment in these tumours. Involvement of resection margins, extraparotid extension, lymphovascular and perineural invasion along with lymph node metastasis are the common indicator for postoperative radiation therapy

Nanostructured ZnO thin film with improved optical and electrochemical properties prepared by hydrothermal electrochemical deposition technique

Zinc oxide (ZnO) thin films were grown on fluorine-doped tin oxide coated glass substrate by the hydrothermal electrochemical deposition (HTED) route using slightly acidic aqueous zinc acetate solution at 80°C and were characterised by various techniques. The deposited films showed n-type behaviour with improved carrier concentration. The steady state photocurrent densities were found to be 0.4 mA/cm2(under UV irradiation) and 8 μA/cm 2(under visible light illumination) at zero bias potential. Significant improvement of optical, electrochemical and photoelectrochemical properties of deposited films could be achieved using HTED technique

PSP_MCSVM: brainstorming consensus prediction of protein secondary structures using two-stage multiclass support vector machines

Secondary structure prediction is a crucial task for understanding the variety of protein structures and performed biological functions. Prediction of secondary structures for new proteins using their amino acid sequences is of fundamental importance in bioinformatics. We propose a novel technique to predict protein secondary structures based on position-specific scoring matrices (PSSMs) and physico-chemical properties of amino acids. It is a two stage approach involving multiclass support vector machines (SVMs) as classifiers for three different structural conformations, viz., helix, sheet and coil. In the first stage, PSSMs obtained from PSI-BLAST and five specially selected physicochemical properties of amino acids are fed into SVMs as features for sequence-to-structure prediction. Confidence values for forming helix, sheet and coil that are obtained from the first stage SVM are then used in the second stage SVM for performing structure-to-structure prediction. The two-stage cascaded classifiers (PSP_MCSVM) are trained with proteins from RS126 dataset. The classifiers are finally tested on target proteins of critical assessment of protein structure prediction experiment-9 (CASP9). PSP_MCSVM with brainstorming consensus procedure performs better than the prediction servers like Predator, DSC, SIMPA96, for randomly selected proteins from CASP9 targets. The overall performance is found to be comparable with the current state-of-the art. PSP_MCSVM source code, train-test datasets and supplementary files are available freely in public domain at: http://sysbio.icm.edu.pl/secstruct and http://code.google.com/p/cmater-bioinfo

Development of antibiotic loaded mesoporous bioactive glass and its drug release kinetics

Aim of the study was to develop an efficient alternative for bone infections obtained during or after reconstruction surgeries using third generation antibiotic ceftriaxone and sulbactam sodium (CFS)] loaded mesoporous bioactive glass (MBG) nanopowders. MBG nanopowders were prepared using cationic surfactant CTAB by wet chemical process, which gave spherical morphology ( < 125 nm), high surface area (473.2 m(2)/g) and pore volume (0.27 c.c./g). Antibiotic loading to powders was performed through vacuum infiltration followed by freeze drying process and loading efficiency was found to be similar to 40.4% calculated from TGA, verified by CHN analysis (similar to 39%). Other characterizations like XRD, FTIR and EDX also confirmed successful encapsulation of antibiotics into MBG. Antibiotic release kinetics from nanopowders was studied up to7 days in contact with three different buffers (pH 1.2, 4.9 and 7.4) to understand pH dependency of intercalated system. Finally, both the systems have been further studied for antibiotic susceptibility assay by observing `zone of inhibition' against gram positive and gram negative bacteria. We have found that variation in pH environment could slightly control antibiotics release kinetics in terms of clinical applications. We have noticed that CFS-MBG pallets were significantly able to inhibit both pathogens (S. aureus and E. coli) by creating clear `zone of inhibition'. In contrast, visible presence of zone of inhibition was absent in case of bare MBG samples. However elution rate of CFS was initially high followed by sustained release can contribute for treatment of local bone infection and diseases

Performance investigation of Pb(II) removal by synthesized hydroxyapatite based ceramic ultrafiltration membrane: Bench scale study

In this study, a low pressure novel ultrafiltration membrane has been developed using synthesized hydroxyapatite nanoparticle over low cost clay-alumina based porous ceramic substrate with multichannel configuration. The nanoparticles and membrane were characterized by FESEM, EDX, XRD, BET, FTIR analyses. The FESEM and EDX images revealed a crack free uniform hydroxyapatite coating layer over porous support with maximum presence of Ca and P at top of the active layer compared to other ceramic elements. The nominal pore size of the membrane was measured as 2.8 nm (BET analysis). Bench scale membrane separation process was performed for the removal of toxic Pb(II) from spiked aqueous solution using 500 mm long synthesized hydroxyapatite ceramic membrane. The clean water permeability and the flux were 79.8 L m(-2)h(-1) bar(-1) and 28.4 L m(-2)h(-1) (at 0.5 bar pressure), respectively. The developed membrane showed 99.6% rejections of Pb(II) from 5 mg L-1 solutions at 1 bar pressure. Furthermore, pH effect on rejection efficiency was also studied and it demonstrated maximum rejections at pH 7.4. The probable mechanism of high rejection was established by XPS analysis as complexation reaction. The membrane was regenerated and subsequently reused. However, this study highlights on designing, fabrication and performance evaluation of novel hydroxyapatite clay-alumina ceramic ultrafiltration membrane in bench scale via simple method that can be potentially applied for industrial purposes

Low-temperature synthesis of strain sensor based on flexible ZnO nanowire-cellulose paper composite

ZnO nanowire was synthesised chemically at low temperature on a flexible three-dimensional and porous cellulose paper. The morphology and crystallography of the composite was characterised by field emission scanning electron microscope and X-ray diffraction. Performance of the developed ZnO nanowire-cellulose paper composite as strain sensor demonstrated good stability, high gauge factor and good repeatability. The results indicate the possible use of this sensitive and robust strain sensor in the fields of biomedical sciences, MEMS devices and structural health monitoring and other fields