Government College

About: Government College is a based out in . It is known for research contribution in the topics: Population & Ring (chemistry). The organization has 4481 authors who have published 5986 publications receiving 57398 citations.

A malaria outbreak in Naxalbari, Darjeeling district, West Bengal, India, 2005: weaknesses in disease control, important risk factors.

Abstract: An outbreak of malaria in Naxalbari, West Bengal, India, in 2005 was investigated to understand determinants and propose control measures. Malaria cases were slide-confirmed. Methods included calculation of annual blood examination rates (ABER, number of slides examined/population), collection of water specimens from potential vector-breeding sites, sorting of villages in categories depending on the number of abandoned wells within two kilometers radius and review of the DDT spray coverage. Cases were compared with matched neighbourhood controls in terms of personal protection using matched odds ratios (MOR). 7,303 cases and 17 deaths were reported between April 2005 and March 2006 with a peak during October rains (Attack rate: 50 per 1,000, case fatality: 0.2%). The attack rate increased according to the number of abandoned wells within 2 kilometres radius (P < 0.0001, Chi-square for trend). Abandoned wells were Anopheles breeding sites. Compared with controls, cases were more likely to sleep outdoors (MOR: 3.8) and less likely to use of mosquito nets and repellents (MOR: 0.3 and 0.1, respectively). DDT spray coverage and ABER were 39% and 3.5%, below the recommended 85% and 10%, respectively. Overall, this outbreak resulted from weaknesses in malaria control measures and a combination of factors, including vector breeding, low implementation of personal protection and weak case detection.

Synthesis and characterization of magnesium oxide nanocrystallites and probing the vacancy-type defects through positron annihilation studies

Abstract: Magnesium oxide nanocrystallites exhibit certain abnormal characteristics when compared to those of other wide band gap oxide semiconductors in the sense they are most prone to water absorption and formation of a hydroxide layer on the surface. The problem can be rectified by heating and pure nanocrystallites can be synthesized with controllable sizes. Inevitably the defect properties are distinctly divided between two stages, the one with the hydroxide layer (region I) and the other after the removal of the layer by annealing (region II). The lattice parameters, the optical band gap and even the positron annihilation characteristics are conspicuous by their distinct behavior in the two stages of the surface configurations of nanoparticles. While region I was specific with the formation of positronium-hydrogen complexes that drastically altered the defect-specific positron lifetimes, pick-off annihilation of orthopositronium atoms marked region II. The vacancy clusters within the nanocrystallites also trapped positrons. They agglomerated due to the effect of the higher temperatures and resulted in the growth of the nanocrystallites. The coincidence Doppler broadening spectroscopic measurements supported these findings and all the more indicated the trapping of positrons additionally into the neutral divacancies and negatively charged trivacancies. This is apart from the Mg2+ monovacancies which acted as the dominant trapping centers for positrons.

Work-related musculoskeletal pain among dentists in Madhya Pradesh, India: prevalence, associated risk factors, and preventive measures.

Abstract: Dentists are at risk for developing musculoskeletal problems. This provided the impetus for a study of prevalence, distribution, and the associated risk factors of these problems in the dentist population of Madhya Pradesh, India. The data were analyzed from 213 dentists of Madhya Pradesh, India, who fulfilled the inclusion criteria and gave their consent for this cross-sectional study. Subjects were assessed by a special questionnaire using demographic details with working conditions. Chi-square test was used for the statistical analysis of the data. Of total 213 participants, 83.10% had at least one musculoskeletal pain in the past 12 months. Low back pain was most frequent (57.75%) followed by neck pain (31.17%) and wrist pain (17.84%). The pain was significantly prevalent among the group who worked in direct vision, without assistant, in standing position or following none of the fitness regimen.

Effect of nickel on plant water relations and growth in green gram

Abstract: Effect of nickel on water potential (ψw), osmotic potential (ψs), turgor potential (ψp) and relative water content (RWC) was studied in the first trifoliate leaf of green gram [Vigna radiata (L.) Wilczek] in order to establish its possible influences on growth through altered water relations. Plants were grown on silica with nutrient solution containing 1, 10, 100 and 1,000 μM, Ni as NiC12·6H2O. The effect of Ni on water relations was highly concentration dependent. The growth promoting concentration of Ni (1 μM) resulted in the highest ψw and ψp, and lowest ψs. The growth inhibiting concentrations of Ni (10, 100 and 1,000 μM) significantly decreased ψw and ψp. At 1,000 μM Ni significantly increased ψs. At 1 μM Ni significantly increased RWC, while it was adversely affected at 10–1,000 μM Ni concentrations. One μM Ni treatment increased chlorophyll contents and growth, while higher concentrations (10–1,000 μM) of Ni significantly decreased the chlorophyll contents and growth.

Miscibility, UV resistance, thermal degradation, and mechanical properties of PMMA/SAN blends and their composites with MWCNTs

Abstract: Poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) (PMMA/SAN) blends, with varying concentrations, were prepared by melt-mixing technique. The miscibility is ensured by fixing the acrylonitrile (AN) content of styrene acrylonitrile (SAN) as 25% by weight. The blends were transparent as well. The Fourier transform infrared spectroscopic (FTIR) studies did not reveal any specific interactions, supporting the well accepted 'copolymer repulsion effect' as the driving mechanism for miscibility. Addition of SAN increased the stability of PMMA towards ultraviolet (UV) radiations and thermal degradation. Incorporation of even 0.05% by weight of multi-walled carbon nanotubes (MWCNTs) significantly improved the UV absorbance and thermal stability. Moreover, the composites exhibited good strength and modulus. However, at higher concentrations of MWCNTs (0.5 and 1% by weight) the thermo-mechanical properties experienced deterioration, mainly due to the agglomeration of MWCNTs. It was observed that composites with 0.05% by weight of finely dispersed and well distributed MWCNTs provided excellent protection in most extreme climatic conditions. Thus, PMMA/SAN/MWCNTs composites can act as excellent light screens and may be useful, as cost-effective UV absorbers, in the outdoor applications.