Investigating photocatalytic activity of titania coated fresh water diatom frustules by the degradation of polluting dye

Silica frustules of diatoms contain nanoscale pores arranged in periodic order. In this report we have synthesized TiO2 nanoparticles coated diatom frustules followed by annealing at 500ºC. The as synthesized DT500 catalyst is characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM) and EDX. UV-visible spectroscopy is performed to analyze the band gap (BG) energy of the material which is found to lie in the visible light range. The photocatalytic properties of the catalysts are investigated via typical polluting dye as a model organic compound under visible light irradiation. The as synthesized DT500 catalyst contains anatase phase of titania exhibited more light absorption in the visible region and found to have higher photocatalytic efficiency due to morphology of frustules and TiO2 coating

Photocatalytic Degradation of Methyl Orange using MoS2 nanoparticles as catalyst

MoS2 is a semiconductor transition metal dichalcogenide material (TMD) which has exciting optoelectronic properties. Due to its band gap (BG) energy lying in the visible range it shows good photocatalytic behavior. In this report, we have synthesized MoS2 nanoparticles (NPs) and its morphology is characterized using XRD and SEM. EDX is performed to analyze the composition of the as-synthesized material. Multiple BG energy in the visible light range is observed from the analysis of UV-Visible spectroscopy. We have investigated the photocatalytic property by the degradation of Methyl Orange (MO) using MoS2 nanoparticles as catalyst. It is observed that the as-synthesized MoS2 NPs degrade MO very efficiently with 98% degradation using 1mg in 1ml 10μM dye solution in 2hr

Excision of choledochal cyst in children by Roux-en-Y hepaticojejunostomy

The aim of this study was to review our experience of total excision with Roux-en-Y hepatico-jejunostomy for the surgical management of type I and type IVa choledochal cysts in 30 children. Among them, 22 were in type I and 8 in type IVa choledochal cysts. All had complete excision and Roux-en-Y hepaticojejunostomy with no morality. Morbidity consisted of prolong drainage (n=2) and late onset cholangitis/pancreatitis (n=4). Choledochal cyst generally has an excellent prognosis with early complete excision and Roux-en-Y hepaticojejunostomy

Monitoring antimicrobial susceptibility of Neisseria gonorrhoeae isolated from Bangladesh during 1997- 2006: Emergence and pattern of drug-resistant isolates

Gonorrhoea is one of the most common sexually transmitted infections (STIs) in developing countries, and the emergence of resistance to antimicrobial agents in Neisseria gonorrhoeae is a major obstacle in the control of gonorrhoea. Periodical monitoring of antimicrobial susceptibility of N. gonorrhoeae is essential for the early detection of emergence of drug resistance. In total, 1, 767 gonococcal strains isolated from males and females (general population and those with high-risk behaviour) from different parts of Bangla-desh were studied during 1997- 2006 . Minimum inhibitory concentrations of penicillin, tetracycline, cipro-floxacin, ceftriaxone, spectinomycin, and azithromycin for the isolates were determined by the agar dilu-tion method. Isolates resistant to three or more antimicrobial agents are considered multidrug-resistant. The prevalence of plasmid-mediated penicillinase-producing N. gonorrhoeae (PPNG) and plasmid-mediated tetracycline-resistant N. gonorrhoeae (TRNG) was determined. Nine percent of the isolates were resistant to ciprofloxacin in 1997 compared to 87% in 2006. Multidrug-resistant N. gonorrhoeae have emerged in 1997 , and 44% of the strains (n= 66) isolated during 2006 were multidrug-resistant. Forty-two percent of the isolates in 2006 were both PPNG- and TRNG-positive compared to none in 1997 . The rapidly-changing pattern of gonococcal antimicrobial susceptibility warrants the need for an antimicrobial susceptibility-monitoring programme, and periodical analysis and dissemination of susceptibility data are essential to guide clinicians and for successful STI/HIV intervention programmes

The Childhood Acute Illness and Nutrition (CHAIN) network nested case-cohort study protocol: a multi-omics approach to understanding mortality among children in sub-Saharan Africa and South Asia

Introduction: Many acutely ill children in low- and middle-income settings have a high risk of mortality both during and after hospitalisation despite guideline-based care. Understanding the biological mechanisms underpinning mortality may suggest optimal pathways to target for interventions to further reduce mortality. The Childhood Acute Illness and Nutrition (CHAIN) Network ( www.chainnnetwork.org) Nested Case-Cohort Study (CNCC) aims to investigate biological mechanisms leading to inpatient and post-discharge mortality through an integrated multi-omic approach. Methods and analysis; The CNCC comprises a subset of participants from the CHAIN cohort (1278/3101 hospitalised participants, including 350 children who died and 658 survivors, and 270/1140 well community children of similar age and household location) from nine sites in six countries across sub-Saharan Africa and South Asia. Systemic proteome, metabolome, lipidome, lipopolysaccharides, haemoglobin variants, toxins, pathogens, intestinal microbiome and biomarkers of enteropathy will be determined. Computational systems biology analysis will include machine learning and multivariate predictive modelling with stacked generalization approaches accounting for the different characteristics of each biological modality. This systems approach is anticipated to yield mechanistic insights, show interactions and behaviours of the components of biological entities, and help develop interventions to reduce mortality among acutely ill children. Ethics and dissemination. The CHAIN Network cohort and CNCC was approved by institutional review boards of all partner sites. Results will be published in open access, peer reviewed scientific journals and presented to academic and policy stakeholders. Data will be made publicly available, including uploading to recognised omics databases. Trial registration NCT03208725

Eu-doped SnO

A density-functional theory employing generalized gradient approximation was used to study the Eu-doped SnO2. The work here deals with the investigation of the structural and electronic band arrangements in SnO2 with Eu doped at various sites. Through the formation energy calculation, it is observed that the introduction of Eu favors substitution with Sn affecting the crystallite size without manifesting any interstitial defect formations. Eu is found to contribute more prominently near the Fermi level of SnO2 in comparison to oxygen. The higher value of energy state’s peak for Eu doped at the top surface indicates that the contribution of Eu as dopant decreases with the increase in the coordination number

Synthesis of Ag nanoparticles using diatom cells for ammonia sensing

Growth of silver nanoparticles through photo induced bioreduction mechanism on the surface of diatom cells, which is a kind of photosensitive fresh water organism containing hydrated amorphous silica structure, has been found to be a cost-effective, rapid, non-toxic, eco-friendly, photo-induced bottom-up process. This material shows broad absorbance in the visible light spectra. Light sensitive fucoxanthin pigment of diatoms that contain hydroxyl (−OH) groups, play a vital role in the formation of silver cluster on the surface of diatom cells and its growth process. Involvement of the compounds and proteins of the diatoms which are responsible for reduction of metal ions and stabilization of the grown nanoparticles on diatom cells, are confirmed by FTIR analysis. Investigations are done to see if the synthesized samples acted as sensing material in the fabrication of a room temperature sensor of dissolved ammonia. With increase in ammonia concentration the visible light absorption peaks tend to higher intensity with blue shift due to the formation of [Ag(NH3)2]+ complexes causing repulsion between the Ag nanoparticles and consequently lead to the formation of smaller Ag nanoparticles. The intensity of absorption of the as-synthesized material is linearly correlated with the concentration of dissolved ammonia as observed from 0 to 100ppm. The use of naturally occurring diatoms for Ag nanoparticles synthesis has the benefits of amenability for large-scale easy production. Also the experimental findings indicate that the as-synthesized material can act as fast and reliable sensing material. Keywords: Diatoms, Fucoxanthin, Silver nanoparticles, Ammonia senso

WEBSCAT: A web application for the analysis of electromagnetic scattering from small particles

Development of an online web application to simulate and display plane wave scattering from small particles is presented. In particular, the computation of angular variation of the scattering properties (scattering matrix elements, scattering coefficients, single scattering albedo etc.) of particulate matter by using the Mie theory and the T-matrix method was incorporated in the application. Comparison of the results generated by using the web application with other reported benchmark results has shown that the web application is accurate and reliable for electromagnetic scattering computations. (C) 2014 Elsevier Ltd. All rights reserved