A novel reaction of dimethylsulfonium methylide with Michael acceptors: application to the synthesis of difficultly accessible vinyl silanes and styrenes

Rather than the usual cyclopropanation and Peterson-type olefination, conditions for a novel elimination reaction from the adduct of dimethylsulfonium methylide and 2-silylalkylidene/arylidene malonate/cyanoacetate/phosphonoacetate leading to geminally substituted vinyl silanes or styrenes, respectively, have been established.     

Index theorems and supersymmetry in the soliton sector: (II). Magnetic monopoles in 3+1 dimensions

For supersymmetric Yang-Mills theories with Bogomolny-Prasad-Sommerfield monopoles, we use an open-space trace theorem on $\text{R}{}^3$ to calculate the O(?) correction to the monopole mass. For the N = 2 theory, the unrenormalized mass correction is non-vanishing (and divergent). To the same order, we calculate the quantum corrections to the central charges, and demonstrate explicitly that the Bogomolny bound is saturated. We also show that the mass correction for the N = 4 theory vanishes to O(?). Finally we discuss the renormalization of the mass correction for the N = 2 theory. This requires the parameters of the theory to be renormalized in the monopole background-field gauge, although there is no simple way known to do this. We exhibit calculations in standard gauges to show explicitly that they give gauge-dependent answers. Physical arguments based on the Dirac quantization condition suggest that the renormalized mass correction vanishes.     

A source of nonclassical radiations exhibiting photon antibunching

We show that coherent spontaneous emission by a two-level atomic system in a Dicke state placed in a resonant cavity gives a non-classical radiation exhibiting photon-antibunching. It is assumed that the “effective” population of the ground state atoms is initially large compared to unity.     

Budding dynamics of multicomponent membranes

The budding of multicomponent membranes is studied by computer simulations and scaling arguments. The simulation algorithm combines dynamic triangulation with Kawasaki exchange dynamics. The budding process exhibits three distinct time regimes: (i) formation and growth of intramembrane domains; (ii) formation of many buds; and (iii) coalescence of small buds into larger ones. The coalescence regime (iii) is characterized by scaling laws which describe the long-time behavior. Thus, the number of buds, N(bud), decays as N(bud) approximately 1/t(theta) for large time t with theta = 1/2 and theta = 2/3 in the absence and the presence of hydrodynamic interactions, respectively.     

Plane Symmetric Inhomogeneous Cosmological Models with a Perfect Fluid in General Relativity

In this paper we investigate a class of solutions of Einstein equations for the plane- symmetric perfect fluid case with shear and vanishing acceleration. If these solutions have shear, they must necessarily be non-static. We examine the integrable cases of the field equations systematically. Among the cases with shear we find three classes of solutions. PACS No.: 04.20.-q.     

Trust Based Intrusion Detection Technique to Detect Selfish Nodes in Mobile Ad Hoc Networks

The applications and protocols conceived for mobile ad hoc networks rely on the assumption of cooperation amongst the mobile nodes because of lacking infrastructure. All nodes have to spend their precious resources (e.g. battery power, memory, computational power, and network bandwidth) for routing and packet forwarding operations for other nodes, in a cooperative way in the network. However, there are some nodes that may intentionally turn themselves to behave selfishly in order to conserve their valuable resources. The selfish behaviour of such nodes drastically reduces the desired degree of cooperation amongst the mobile nodes. Over the course of time, the non-cooperative activities of, such selfish nodes would paralyze the normal functioning of the whole network. Therefore, these types of nodes should be detected and isolated from the network, as soon as they begin to exhibit their selfish behaviour. In this paper, a dynamic trust based intrusion detection technique is presented to detect and isolate the selfish nodes from the network, where the direct trust degree based on direct communication interactions and indirect (recommended) trust degree based on the neighbours’ recommendations are taking into account to accurately judge the selfishness nature of the nodes. The results obtained throughout the simulation experiments clearly show the feasibility and effectiveness of the proposed intrusion detection technique.     

Transition metal complexes of a hydrazone derived from hydralazine hydrochloride and 3,5-di-tert-butylsalicylaldehyde

Mononuclear Co(III), Ni(II) and Cu(II) coordination compounds of (E)-1-(3,5-di-tert-butyl-2-hydroxybenzylidene)-2-(phthalazin-1-yl)hydrazine (LH) were prepared and characterized by physicochemical and spectroscopic methods. The metal-to-ligand ratio was found to be 1:2 in [Co(L)₂]Cl·2H₂O (1) and [Ni(L)₂]·2H₂O (2), while it is 1:1 in [Cu(L)Cl]·2CH₃OH (3). The X-ray crystal structures of LH and complex 1 is are reported. LH shows monobasic behavior, coordinating through NNO donor atoms. The complexes were investigated for their antimicrobial properties. Complexes 1 and 3 show excellent antibacterial and antifungal activities, respectively.     

Dithiobissuccinimidyl propionate self assembled monolayer based cholesterol biosensor

A dithiobissuccinimidyl propionate (DTSP) self-assembled monolayer (SAM) prepared onto a gold (Au) surface has been utilized for covalent immobilization of cholesterol oxidase (ChOx) and cholesterol esterase (ChEt). These ChOx-ChEt/DTSP/Au bio-electrodes have been characterized using electrochemical impedance and cyclic voltammetric (CV) techniques, respectively. Differential pulse voltammetry (DPV) has been used for enzymatic assay of immobilized ChOx and ChEt onto the DTSP modified gold surface as a function of cholesterol oleate concentration. The response measurement conducted on ChOx-ChEt/DTSP/Au bio-electrode reveal the value of Michaelis-Menten constant (Km) as 0.95 mM suggesting enhanced affinity of enzymes (ChOx and ChEt). The ChOx-ChEt/DTSP/Au bio-electrodes show linearity in range of 50 to 400 mg dl(-1) of cholesterol oleate and the shelf-life of more than 50 days when stored at 4 degrees C. This biosensing electrode shows correlation coefficient of 0.9973 and standard deviation of regression as 0.859 microA.