Benzoxazole-2-thiol/dibenzoyl peroxide combination as photoinitiator for methyl methacrylate polymerization

Benzoxazole-2-thiol ( 1 )/dibenzoyl peroxide (Bz₂O₂) was used as photoinitiator for the polymerization of methyl methacrylate (MMA) in bulk and in solution. The study of initiator decomposition was conducted spectrophotometrically. Kinetic studies of the photopolymerization indicated the formation of a complex between 1 and Bz₂O₂ in the stoichiometric ratio 2:1. The initiation is believed to occur via in situ formation of bis(benzoxazol-2-yl) disulfide in the presence of light.     

Influence of Fluctuating Water Temperature and Dietary Oxytetracycline on the Safety of Monosex Nile Tilapia Oreochromis niloticus Fries

The influence of fluctuating water temperature and dietary oxytetracycline (OTC) at 0 (0X), 80 (1X), 240 (3X), 400 (5X) and 800 mg (10X)/kg biomass/day for 30 consecutive days on the safety of monosex (all male) Nile tilapia Oreochromis niloticus fries in terms of feeding, growth, survival and histopathology of vital organs were assessed. A dose-dependent decline in feed intake and biomass was recorded. The OTC-dosed groups recorded higher mortalities than the control. The therapeutic OTC-dosing (1X) in conjunction with low temperature caused 75.56 ± 8.01% mortality and 25.75% reduced feed intake in 30 days. The mortalities increased with increasing OTC-doses from 85.19 ± 3.39% (1X) to 95.56 ± 2.22% (10X) and fluctuating temperature (12.00–21.50°C) even after the withdrawal of OTC. Relatively mild to moderate histopathological lesions were observed in the kidney, liver and intestine of OTC-dosed fries. These results suggested that dietary OTC and low water temperature may cause adverse effects on monosex O. niloticus fries.

     

Clinico-immunological profile in a case of hepatic tubercular abscess: A rare manifestation of extrapulmonary TB in an immunocompetent child

Tubercular liver abscess is a rare entity even in an endemic area for TB. We report here a rare case of pediatric tuberculous liver abscess, the etiology of which was established using recently introduced Cartridge based nucleic acid amplification test (CBNAAT). A 7 years old male child presented with vomiting, pain abdomen and fever. Hepatomegaly was found on examination. Ultrasound of abdomen revealed two liver abscesses in the right lobe. Patient remained symptomatic even after empirical antimicrobial therapy. On diagnostic tap Gram stained smear of the pus showed polymorphs with negative culture. CBNAAT was positive for Mycobacterial tuberculosis and sensitive to rifampicin. Subjecting difficult extrapulmonary specimens to relevant microbiological investigations along with CBNAAT and other newer methods may improve diagnosis of tuberculosis in such rare cases thus leading to an early management and decrease in morbidity.     

Phytoplankton nutrient dynamics and flow cytometry based population study of a eutrophic wetland habitat in eastern India,a Ramsar site

Phytoplankton diversity, their abundance based on flow cytometric (FCM) analysis and seasonal nutrient dynamics were investigated from a waste water fed wetland of Eastern India (88° 24.641′E and 22° 33.115′N). The primary objective of the study was to correlate the seasonal fluctuations in phytoplankton abundance to the environmental variables. Total chlorophyll content and FCM based cell counts were used to characterize and quantify the phytoplankton population. Multivariate statistical methods were employed in predicting the possible relationships between biotic and abiotic variables. Distinct seasonal variations characterized by high abundance during the pre-summer period compared to other seasons were detected. The results indicated that environmental factors like water temperature and nutrients, such as various forms of nitrogen and phosphate, influenced the seasonal phytoplankton accumulation. Cluster analysis and non-metric multidimensional scaling helped analyze the seasonal distribution of phytoplankton based on their composition. The dominant genera among the entire phytoplankton community were Scenedesmus spp. of Chlorophyta, followed by Merismopedia spp. of Cyanoprokaryota. Around 3.7 × 10⁵ phytoplankton mL⁻¹ were recorded during the study period. Due to the very high count of individual species in the community, FCM based counting was applied for determination of Species Diversity Index. The entire population was divided into 13 subpopulations based on the cell sorting method and the seasonal abundance in each sub-population was illustrated.

Phytoplankton diversity, their abundance based on flow cytometric (FCM) analysis and seasonal nutrient dynamics were investigated from a waste water fed wetland of Eastern India (88° 24.641′E and 22° 33.115′N).     

Assessing seasonal trends and variability of vegetation growth from NDVI3g,MODIS NDVI and EVI over South Asia

The characterization of vegetation dynamics over South Asia (SA) has been primarily conducted using satellite time series of Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (NDVI). However, various vegetation indices may show diverse trend patterns over the same area. This study analysed the consistency of the vegetation spatiotemporal trends from AVHRR version 3 NDVI (NDVI3g) with the Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI and Enhanced Vegetation Index (EVI) over SA during various seasons, assuming that MODIS products are of higher quality. Results showed that the spatiotemporal vegetation trends derived from the NDVI3g were analogous to both MODIS NDVI and EVI indicating greening over semi-arid regions where croplands dominate and browning over tropical/subtropical forest areas. Correlations among them were better during winter monsoon. Discrepancies occurred in tropical/subtropical densely vegetated (humid) and complex topographic areas specifically during summer monsoon (SM). This study improved the understanding of the heterogeneous vegetation trends over the vast complicated terrain of SA. It was revealed that NDVI3g is reliable to quantify vegetation trends over SA, however, calibration errors still could introduce biases during SM season.     

Nitric oxide integrated polyethylenimine-based tri-block copolymer for efficient antibacterial activity

The work demonstrated a successful synthesis of nitric oxide (NO)-releasing material and its antibacterial effect on Gram-negative Escherichia coli (E. coli), Gram-positive Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA). The polymeric support composed of thermosensitive Pluronic F68 having good biocompatibility and branched polyethylenimine (BPEI) housed N-diazeniumdiolates (NONOates) which could store and release NO under appropriate physiological condition. The developed F68–BPEI–NONOates releases a sufficient amount of NO under physiological condition to elicit effective killing of E. coli, S. aureus and MRSA. The antibacterial ability of the released NO was compared to untreated control or unmodified F68 polymer by using confocal microscopy; F68–BPEI–NONOates demonstrated excellent antibacterial activity with in vitro low cytotoxicity. TEM investigation also revealed the destruction of bacteria membrane caused by NO. The effectiveness of F68–BPEI–NONOates against resistant strains such as MRSA provides a very simple but highly efficient strategy to combat drug-resistant bacterial infections.     

Complete genome sequence analysis of Japanese encephalitis virus isolated from a horse in India

The complete genome of the Japanese encephalitis virus (JEV) strain JEV/eq/India/H225/2009(H225), isolated from an infected horse in India, was sequenced and compared to previously published JEV genomes. H225 genome was 10,977-nucleotides long, comprising a single ORF of 10,299-nucleotides, a 5′-UTR of 95 nucleotides and a 3′-UTR of 582 nucleotides. The H225 genome showed high levels of sequence identity with 47 fully sequenced JEV genomes, ranging from 99.3 % to 75.5 % for nucleotides and 99.2 % to 91.5 % for amino acid sequences. Phylogenetic analysis of the full-length sequence indicated that the H225 strain belongs to genotype III and is closely related to the Indian JEV strain Vellore P20778. A comparison of amino acids associated with neurovirulence in the E proteins and non-structural proteins of known virulent and attenuated JEV strains suggested H225 to be a highly virulent strain. This is the first report of whole-genome sequencing of a genotype III JEV genome isolated from equines.     

Detection of New Delhi Metallo‐beta‐Lactamase and Extended‐Spectrum beta‐Lactamase Genes in Escherichia coli Isolated from Mastitic Milk Samples

In this study, eight Escherichia coli isolates were obtained from milk samples of dairy cattle suffering from clinical/subclinical mastitis. Isolates were characterized for antimicrobial resistance traits and virulence genes. Results revealed that one isolate was harbouring New Delhi metallo‐beta‐lactamase gene (bla_NDM). Cloning and sequencing of the PCR amplicon confirmed the identity of the gene (GenBank accession no. KC769583 ) having 100% homology with bla_NDM‐5 (GenBank accession no. JN104597.1 ), and this isolate was susceptible to colistin, chloramphenicol and tetracycline only. Moreover, another isolate carried extended‐spectrum beta‐lactamase (ESBL) gene – bla_CTX‐M, and all isolates possessed bla_TEM gene. Of the eight isolates, only one isolate was positive for shiga toxin gene (stx2), and none were harbouring stx1 gene. Occurrence of New Delhi metallo‐beta‐lactamase (bla_NDM) in one E. coli isolate and ESBL genes in other isolates poses a potential threat to human health following possible entry and spread through food chain.