A theoretical study of methanol oxidation mechanisms by methanol dehydrogenase enzymes for fuel cell applications

Enzymes are considered for electrochemical generation of power in fuel cells. Methanol dehydrogenase (MDH) is one such enzyme, which has been used as an anodic catalyst for a methanol-fed biofuel cell producing enough power for small electronic device applications. In practice, however, there are power output limitations associated with this MDH fuel cell, which may potentially be eliminated or reduced if the reactivity of this enzyme during the oxidation of methanol at the molecular level is clearly understood. Two mechanisms for the methanol oxidation process by MDH have been proposed in the literature, Addition-Elimination (A-E) and Hydride Transfer (H-T), but no agreement has been reached about what mechanism actually operates in reality. Also, it was suggested that ion-modified MDH, particularly Ba 2+-MDH enzyme, is more active towards oxidation of methanol than Ca 2+-MDH from experimental kinetic observations. In this dissertation, MDH active site models of varying sizes were tested for the A-E and H-T methanol oxidation in the presence of both Ca2+ and Ba2+. Potential energy surfaces for the reactions were calculated, and the feasibility of the suggested reaction mechanisms was judged by comparison with available experimental free energy barriers. By systematically increasing the size of the models, deeper insight into the details of the reactions was obtained, and the role of the various active site residues was also analyzed. Comparison of free energy barriers calculated for the rate-determining steps in this work for the A-E and H-T oxidation mechanisms with experimental Gibbs energy of activation by Ca2+-MDH showed that these two mechanisms may not be correctly proposed in the literature. Also, the reduction of barriers for the rate-determining steps in the presence of Ba2+ for A-E and H-T obtained with the best MDH active site model tested here is almost twice as much the experimental free energy reduction with Ba 2+-MDH for methanol oxidation. A modified first step of original H-T resulted in a newly proposed two-step H-T oxidation mechanism, where the barrier for the formation of final product, formaldehyde, during the first step is very much comparable (11.4 kcal/mol) to the experimental Gibbs energy of activation (8.5 kcal/mol). In the case of Ba2+ presence during this new mechanism, the free energy barrier is 6.2 kcal/mol, which is comparable to free energy of activation for oxidation of methanol by Ba2+-MDH (3.5 kcal/mol). The second and final step involving proton transfer in this Two-step H-T was observed to be mediated by a water molecule in the presence of both ions. Moreover, DFT-MD investigations on the reactant complex and necessary intermediates associated with all mechanisms also lead us to the conclusion that oxidation of methanol by MDH has a greater probability of proceeding through the two-step hydride transfer mechanism compared to proposed A-E and H-T

Skilled yet lost? Challenges of international medical graduates in psychiatry: Australian perspective

Abstract of presentation at the 67th Annual National Conference of the Indian Psychiatric Society (ANCIPS 2015), at Hyderabad, India, 8-11 January 2015

Early Australian experience in the maintenance of schizophrenia management with 3-monthly paliperidone palmitate

Objectives: Real-world experience from a 6-month product familiarization programme (PFP) for 3-monthly paliperidone palmitate in schizophrenia maintenance treatment. Methods: Prescribers completed an online questionnaire for each patient at enrolment with further questions at second dose (re-supply) stage and a second survey of their overall experience at the end. Results: Ninety-four patients were enrolled and received a first dose and 23 received a second dose within the 6-month programme; 51.1% had been hospitalised for symptom relapse in the previous 2 years. Reasons for prescribing were convenience of 3-monthly dosing for patients (94.7%) and patient choice (54.6%). Prescribers followed-up at least once-monthly (69.6% cases) and indicated in 48.9% they would consider shared GP care. All patients were satisfied with symptom control and either maintained functioning or showed improvement. Clinicians felt confident with administration and identifying suitable patients and were all \u27satisfied\u27 or \u27somewhat satisfied\u27 with efficacy and tolerability. All felt patients\u27 treatment goals were either \u27met\u27 (81.3%) or \u27partly met\u27 (18.7%) and none reported dissatisfaction with relapse prevention. Conclusions: Convenient 3-monthly dosing was preferred by clinicians and patients, and symptoms were adequately managed. This has the potential to improve adherence and lead to better outcomes as patients only need four intramuscular doses per year

A systematic review of the quality of life of carers of children with cleft lip and/or plate

Caring for an infant or child requires a significant amount of time, energy and resources; this burden is further increased when the infant or child has a chronic condition or disability. Prior research has demonstrated that caregiving for a child with special needs impacts upon parents or carers mental health, well-being and quality of life. This article systematically reviews the literature pertaining to the impact of caring for a child with cleft lip and /or palate upon parental quality of life. A search of four databases was conducted with a number of key terms; the titles, abstracts and finally the whole article were read and assessed for relevance. Only articles written in English were included in the review. The results yielded four relevant articles; that displayed inconsistent results. The results of these articles are reviewed. It was evident that the construct of quality of life was narrowly operationalised in all four articles either being assessed as health-related quality of life or as the impact upon the family. Further all four studies emanated from the same country. The limitations are discussed with recommendations made for future research endeavours

Depletion of glutathione and enhanced lipid peroxidation in the CSF of acute psychotics following haloperidol administration

Haloperidol administration for 2 weeks results in significant reduction in the concentration of GSH in the CSF. Concomitantly, the levels of lipid peroxidation products increased as evidenced by increased malondialdehyde levels. The malondialdehyde levels in the CSF prior to haloparidol administration were not significantly higher than that seen in CSF from normal controls (data not shown) suggesting that increased oxidative stress did not exist in these patients prior to haloperidol administration. All the patients included in the present study were drug naive and hence the changes observed in the glutathione and malon6ialdehyde levels in the CSF were indeed mediated by haloperidol administration. The only other medication that was administered namely, anticholinergic drug, trihexyphenidyl is not known to cause any oxidative stress. The present study thus demonsuates that haloperidol administration results in significant oxidative stress. The generation of the oxidative stress is probably due to the increased turnover of dopemine caused by typical neuroleptics. Increased dopamine turnover is also observed in Parkinson's disease and the combination therapy consisting of antioxidant vitamin E and monoamine oxidase inhibitor, deprenyl has been shown to offer limited protection against the progression of the disease (Parkinson Disease Study Group 1989). In the present study, all the 15 patients exhibited extrapyramidal symptoms although the time of onset, the duration and the severity of the side effects differed between patients. On the presumption that the oxidative stress generated by haloperidel may cause extrapyramidal symptoms, the present study in humans taken together with the evidence provided in our earlier studies on rats (Shivakumar and Ravindranath 1992,1993) may justify experimental coadministration of antioxidanls (e.g., vitamin E) with typical neuroleptics like haloperidol to prevent the acute side effects

Optimal Power Flow with Static VAR Compensator Using Galaxy Based Search Algorithm to Minimize Real Power Losses

AbstractIn this paper, Galaxy based search algorithm (GbSA) is used to solve multi-objective problem of optimization in power systems. The proposed GbSA resembles the spiral arms of some galaxies to search for the optimal solutions. The GbSA also uses a modified Hill Climbing algorithm as a local search. Simulation results show that the GbSA finds the optimal or very near optimal values in all runs of the algorithm. The weighted sum technique with equal weights has been chosen to solve the multi-objective function. The functions considered are to minimize the power losses in transmission line, cost of the real power generation and voltage deviation. Static VAR Compensator (SVC) is used for the purpose of optimal power flow. L-index is used to identify the optimal location to place SVC. The results have been compared with Genetic algorithm (GA) for IEEE-14 System

CBDC: EMPIRICAL STUDY ON DETERMINANTS OF CBDC USAGE PURPOSE AMONG CONSUMERS

Abstract The initiative from the government of India in making India into a digitally vibrant nation is highly admirable. India economic growth over the decade is raising at higher rate, it due to adoption of digitalization in every part of economy from banking, business, and international payment. Banks are updating according to needs and demands of the consumers providing amenable services at finger tips of the consumers. From small vendor to high business transitions are carry forward with the help of digital transition or digital currency. The primary objective of the study is determining CBDC usage purpose among consumers. The study used convenient sampling method and covered 160 banking consumers using digital banking. The findings of the study show Determinants of CBDC Usage Purpose among Consumers have been segregated into two dominant dimensions namely Payment Terminal and Financial Statibility Factor which dealing with cost of using online banking, usage of the same at all branches both nationally and internationally and security of the banking. The second factor is Usage and Payment Efficiency Factor which deals with usage of the digital banking, efficiency of the payment over the geographical location and ability of use the same without internet connections. Consumer Perception on CBDC have been segregated into two dominant dimensions namely Expectancy and Performance Factor which deals with expectancy of the consumers over usage of CBDC, knowledge on using digital currency and trust over the banking while using digital currency. A positive and significant impact of Consumer Perception on CBDC on Determinants of CBDC Usage Purpose among Consumers has been identified

ADVERTISEMENT EFFECTIVENESS: "IMPACT OF CELEBRITY ENDORSEMENT AND ADVERTISEMENT EFFECTIVENESS ON CONSUMER PURCHASE BEHAVIOUR"

Abstract Advertisement is the key for promoting any product or service to the consumer. It greatly attracts consumer to purchase product from the marketer. The usage of celebrity in advertainment strongly influence the purchase behaviour of consumer in long run. The presence of celebrity in an advertisement stimulate consumer and possessing him to purchase the product or service. The objective of the present study is to assess the role of celebrity endorsement and advertisement effectiveness in influencing consumer purchase behaviour in the city of Bangaluru. The study adopted stratified random sampling method and collected around 240 samples after segregating the city into four zones. To assess the celebrity endorsement 12 determinant have been observed which were factorised into two dominant factors, while advertisement effectiveness has been measured with eight variables which were factorised into two dominant factors namely Glorious and Transparency Factor and Hallmark and Significance Factor. The consumer purchase behaviour have been measured using ten determinants and are factorised into two factors namely Engrossment and Apprising Factor and Willingness and Involvement Factor. The outcome of multiple regression and SEM shows that both celebrity endorsement and advertisement effectiveness have significant influence on Consumer Purchase Intention of Celebrity Endorsed Product. It is suggested that market need to focus more on faithfulness and integrity of the advertisement which in turn attract and uphold the existing customer in long run. To enhance the reaches of the advertisement among the consumers, marketer should focus on positivity of the product contents

Defect Investigation as a Tool for Quality Improvement

Defect investigation is an important tool for quality improvement as it identifies the root cause of errors and steps to be taken to eliminate these. In this paper, four cases of defect investigation are presented. The case studies cover link elevator, wing-fuselage attachment bolt, and stiff nut for Lakshya unmanned aerial vehicle. It was observed that the link elevator was discolourised even though the material used was the stainless steel. Investigations revealed that the stainless steel was heat-treated. In the case of leading edge, it was found that there was no provision for the location of a component in the tool, resulting in mismatch. Thread damage was noticed in wing-fuselage attachment bolts because of over tightening. All these studies resulted in improvement in the raw material bonding, inspection procedures, and fabrication methods, thus resulting in quality improvement

CONSUMER BEHAVIOUR: AN EMPIRICAL STUDY ON CONSUMERS' PERCEPTION ON PURCHASE BEHAVIOUR TOWARDS E-PRODUCTS THROUGH E-RETAIL MARKET

Abstract The emergence of internet has created opportunities for firms to stay competitive by providing customers with a convenient, faster and cheaper way to make purchases. Electronic Retailing is more than just buying and selling products online. It also includes entire online process of developing, marketing, selling, delivering, servicing and paying for products and services. India has shown tremendous growth in E-Retailing segment. With an internet user base of over 300 million, India has third largest internet population after US & China. India has witnessed major breakthrough E-commerce success stories particularly in e-retail in Consumer Electronics & Fashion Apparel & Home Furnishing segments. E-Retailing creates new opportunities for entrepreneurial start-ups. Ease of Internet access, Safe and secure payment modes coupled with aggressive marketing by E-Retailing Giants has revolutionized this segment. Rapid development in mobile technology has given way to e-logistics companies to serve people as and when required very effectively