Katwa College, established in 1948, is one of the oldest colleges in Katwa, in Purba Bardhaman district. It offers undergraduate courses in Arts, Commerce and Sciences. It is affiliated to Burdwan University.
The nonlinear interactions of compressional Alfv & eacute;n wave and a steadily moving charged obstacle are examined in Hall magnetohydrodynamics (MHD). The interaction dynamics is shown to be described by a forced derivative nonlinear Schr & ouml;dinger equation (fDNLSE). The steadily moving charged obstacle induced weak perturbation is responsible for the forcing term. The variational structure is used to investigate the exact solitary wave solutions of the fDNLSE for a special analytic form of the forcing term by constructing a proper Hamiltonian of the system. The conditions for the stability of these solitary waves are delineated through variational method. The numerical solutions using the split-step Fourier method confirm the analytical results representing the pinned solitons. The relevance and potential applications of the results in astrophysics are also discussed.
Two new thiocyanato-bridged copper(ii) complexes of 1D polymeric chains of molecular formula [Cu(L1)(mu 1,3-NCS)]n (1) and [Cu(L2)(mu 1,3-NCS)]n (2) [HL1 = N-propyl-N-(5-bromosalcylidine)ethane-1,2-diamine; HL2 = N-propyl-N-(5-chlorosalcylidine)ethane-1,2-diamine] have been synthesized and characterized. Characterizations of 1 and 2 have been accomplished by several physicochemical techniques, including single crystal X-ray diffraction studies. X-ray diffraction analyses of 1 and 2 reveal that the monomeric units of the 1D polymers are bridged and interconnected via the mu 1,3-thiocyanato group. The coordination geometry around the Cu centers in 1 and 2 can be best described as a distorted square pyramidal environment. The current-voltage characteristics of the Al/1/ITO and Al/2/ITO structures have been analysed by considering the thermionic emission theory of the Schottky barrier diode. Employing a conventional method, the barrier height and ideality factor have been calculated to be 0.89 eV and 3.84 for 1, and 0.84 eV and 3.75 for 2, respectively. The series resistances have been obtained graphically as 4.24 x 103 Omega for Al/1/ITO and 2.65 x 103 Omega for Al/2/ITO structures using the modified Norde's technique. Both complexes 1 and 2 show moderate catecholase activity as observed by examining the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) to 3,5-di-tert-butylquinone (3,5-DTBQ). Density functional theory (DFT) calculations, including HOMOs and LUMOs, were carried out to acquire the Fukui function values at the Cu centers in 1 and 2 to understand that the substrate 3,5-DTBC most likely binds with the Cu(ii) for its activation during the catalytic process. However, a comparative assessment of their catecholase activities indicates that 2 (kcat = 29.76 h-1) has superior catalytic efficacy in comparison to 1 (kcat = 11.15 h-1).
Two new polymeric complexes of Ni(II), trans-{[Ni(en)2(dca)]& sdot;(dca)& sdot;H2O}n (1) and cis-{[Ni(en)2(dca)]& sdot;NO3}n (2) has been synthesized by reacting the nickel nitrate, ethylenediamine (en) and sodium dicyanamide {Na(dca)} in methanol-water medium. Structural analysis shows that both the complexes are 1D polymers, formed by linking the Ni(en)2 units through the mu 1,5-dicyanamido bridge. In complex 1, two bridging dca- anions coordinate with Ni (II) with respect to trans with each other whereas in complex 2, two dca- anions coordinate with Ni (II) with respect to cis with each other. Both the 1D polymers are connected by hydrogen bonding interactions to form a 3D supramolecular structure. Theoretical analysis shows that complex 1 is more stable than complex 2. The antimicrobial properties of complexes 1 & 2 have been investigated against E. coli, a gram-negative bacterium and B. subtilis, a gram-positive bacterium; they show positive inhibition activities. In the electrical studies, direct current (dc) measurements on the copper/complex (1 or 2)/copper M-S-M planar structure corroborates a definite development in the device current with applied bias, ranging between -2 V and +2 V. Moreover, in the ac analyses, both the Cu/1/Cu and Cu/2/Cu devices have shown decreasing trend in frequency dependent zero bias capacitance.
BackgroundHost genetic variation plays a critical role in shaping inflammatory responses to chronic environmental exposure in Chronic Obstructive Pulmonary Disease (COPD). The non-synonymous CHRNA5 polymorphism rs16969968 (G>A; D398N) has been associated with nicotine dependence; however, its immunomodulatory relevance in COPD remains insufficiently explored.ObjectivesTo investigate the association of the CHRNA5 rs16969968 polymorphism with COPD susceptibility and its relationship with inflammatory protease expression and cholinergic signaling pathways in a West Bengal population.MethodsWe enrolled 412 COPD patients and 390 controls (41–80 years). Lung function was assessed by spirometry. Genotyping was performed using the PCR-RFLP method. CHRNA5 and MMP9 mRNA expression levels were quantified by qRT-PCR, and CHRNA5 protein expression was assessed via Western blot; BALF MMP-9 levels were measured by ELISA. Computational tools were used to predict the potential structural and functional effects of the variant.ResultsThe rs16969968 AA genotype was significantly enriched among COPD patients and was associated with reduced pulmonary function in smokers. Carriers of the risk genotype reported lower CHRNA5 transcript and protein expression levels along with higher MMP-9 expression compared with other genotypes. In-silico analyses also predicted that the variant D398N likely to exert subtle functional effects on α5 nicotinic acetylcholine receptor subunit.ConclusionThe findings suggest that the CHRNA5 rs16969968 variant is associated with altered cholinergic signaling and increased MMP-9 expression in COPD. These observations support a potential role for CHRNA5-related inflammatory pathways in COPD susceptibility and tissue remodeling. However, the observed associations require further functional and mechanistic validation.
This study uses advanced geospatial technologies to examine the dynamics of Land Use Land Cover (LULC) changes, agricultural development, and their impacts on water storage (WS) in Haora district, West Bengal, India. Spanning 1467 square kilometers, Haora district has experienced significant LULC transformations between 2001 and 2011, closely linked to a substantial decline in WS. The district’s population, which has grown to 4.8 million at an annual rate of 13.3
