Search

This paper presents the effect of quantum confinement on the potential of short channel mono-layer molybdenum disulfide (MoS2) based transistor using Ritz Galerkin finite element technique. Unlike earlier models, only two iterations are used to obtain the potential. This model makes use of the coupled Poisson-Schrödinger equation by considering quantum mechanical effects for evaluating the potential with the support of Exciton Bohr radius, bandgap, electron energy state, Density of State (DOS), and electron concentration. Furthermore, this coupled equation along with Neumann boundary condition is employed to approximate the wave function of the Schrödinger equation, which is used again in the Poisson equation for calculating the potential. This work accurately predicts the impact of quantum confinement effects in the perpendicular direction of the channel surface. [ABSTRACT FROM AUTHOR]

This paper investigates quantum mechanical effects on surface potential and threshold voltage in a two-dimensional molybdenum disulfide (MoS 2 ) based transistor. Drain current improvement occurs as a result of the low work function for metal Ti and electron affinity of MoS 2 , thereby reducing the Schottky barrier height (SBH). The titanium (Ti) contact introduced into the mono-layer MoS 2 helps in obtaining lower contact resistance and improved drain current due to the lowering of SBH. An analytical model is proposed for evaluating various device parameters such as surface potential, threshold voltage, contact resistance, mobility, and drain current. This model provides useful aspects for understanding the physics of quantum mechanical effects. Compared to other conventional devices, this transistor incorporates Ti, a low work function metal, in the contact region, producing better current drive and lower contact resistance values. A positive Schottky barrier is noticed between the mono-layer MoS 2 and the Ti metal. Compared to other high function metals, the proposed device displayed about 11% improvement in current drive and 8% less contact resistance. By attaining an enhanced carrier injection and decreased contact resistance, this device serves as a suitable prospect for low-power applications. [ABSTRACT FROM AUTHOR]

The expressed recombinant leptospiral surface adhesion lipoprotein (Lsa27) of pathogenic Leptospira in E. coli was evaluated for the detection of Leptospira antibodies in cattle sera by latex agglutination test (LAT). The Lsa27 lacking signal peptide coding gene sequences from L. interrogans serovar Pomona was amplified (~ 660 bp) by PCR and the amplicon was cloned into pETiteN-HisKan vector. The expressed recombinant Lsa27 histidine-tagged fusion protein (rLsa27) was Ni–NTA affinity purified under denaturation followed by renaturation methods. The purified rLsa27 was characterized by SDS-PAGE and immunoblot, which confirmed the leptospiral protein with a MW of ~ 25 kDa. Further, the prepared sensitized latex beads coated with rLsa27 were evaluated as a diagnostic antigen for detection of pathogenic Leptospira antibodies by using known microscopic agglutination test (MAT) positive (n = 74) and negative (n = 62) sera for Leptospira antibodies in LAT, which revealed the relative diagnostic sensitivity of 91.89% and specificity of 87.10% against the gold standard serological test, MAT. Furthermore, on evaluation of developed rLsa27 LAT using serum samples from cattle associated with the history of abortions and reproductive disorder (n = 309), the relative sensitivity of 96.15%, and specificity of 89.11% were observed. Therefore, this rapid field test using the rLsa27 is first of its kind and it could be used as a screening test for the detection of Leptospira antibodies or it can be complemented by other diagnostics for the diagnosis /surveillance of bovine leptospirosis. [ABSTRACT FROM AUTHOR]

Congestive heart failure (CHF) is a major public health problem that results in tremendous economic burden. Diastolic heart failure (DHF) forms an important subset with increasing incidence and prevalence. There are widely variable estimates of the prevalence, ranging from 13% to 74% of all CHF presentations, and this is predominantly a result of a lack of uniform criteria for establishing a diagnosis. New developments in management of DHF have lagged behind those for systolic heart failure (SHF), for which numerous new therapeutic and device strategies have been instituted. The renin-angiotensin-aldosterone system (RAAS) plays an important role in the pathophysiology of both SHF as well as DHF. The beneficial role of ACE inhibitors as well as aldosterone antagonists in SHF has been well established. Because of its unique role of the RAAS in establishing fibrosis at a molecular level, RAAS blockade provides an opportunity to expand the therapeutic options for DHF. Thus far, in patients with primary DHF only the angiotensin receptor type 1 antagonist candesartan has been reported to decrease morbidity and probably mortality. Large, ongoing randomized trials including TOPCAT (Trial of Aldosterone Antagonist Therapy in Adults with Preserved Ejection Fraction Congestive Heart) and the I-PRESERVE (Irbesartan in Heart Failure with Preserved Systolic Function) are currently underway to establish the role of aldosterone antagonists in patients with DHF. [ABSTRACT FROM AUTHOR]