The Reduction of Alkynes over Pd-based Catalyst Materials-A Pathway to Chemical Synthesis

Many reactions, including selective hydrogenation of alkynes, take place on solid surfaces. These reactions are vital in many areas of industry including the manufacture of polymers and fine chemicals such as vitamins, fragrances, and drugs. The choice of a catalyst is a trade-off between activity, selectivity and costs. Palladium-based heterogeneous catalysts are traditionally used for these processes as they provide the activation of hydrogen at room temperatures and offers reasonable selectivity, but these catalysts have a number of practical drawbacks. This review discusses recent research work in the selective hydrogenation of alkynes on palladium-based catalysts, emphasises the mechanism and catalytic materials and important applications including alkyne removal from gas-phase alkene precursors for polymer synthesis and liquid phase selective hydrogenation for the synthesis of fine chemicals. Langmuir-Hinshelwood reaction kinetic models, reaction intermediates, formation of carbonaceous layer, the nature of active sites and the effects of reversible and irreversible adsorbates over Pd surface are discussed as well as the factors affecting catalyst activity and selectivity and how these can be optimised in synthetic protocols for these reactions

Fabrication of novel carbon quantum dots modified bismuth oxide (α-Bi2O3/C-dots): Material properties and catalytic applications

The present work reports the facile and the template free sonochemical synthesis of a novel catalyst, α-Bi2O3/C-dots, for the degradation of indigo carmine (IC) dye, its simulated dyebath effluent and levofloxacin under visible light catalysis. The compositional, structural, optical and morphological analysis of α-Bi2O3/C-dots was studied using analytical, spectroscopic and microscopic techniques. X-ray diffraction (XRD) results confirmed the presence of a monoclinic phase of α-Bi2O3in the nanocomposite and crystallite size of 28.75 nm. Photoluminescence (PL) and UV–vis diffuse reflectance spectra (UV-DRS) studies showed good optical properties and a band gap of 2.49 eV. The synthesized photocatalyst showed superior visible-light driven photocatalytic activity for the degradation of indigo carmine dye (86% dye degradation in 120 min) compared to pure α-Bi2O3(57%). α-Bi2O3/C-dots also exhibited 79% degradation of antibiotic drug levofloxacin within 120 min, under optimized conditions of pH, catalyst dose and initial dye concentration. Scavenger studies revealed that hydroxyl radicals and electrons played predominant roles in the photocatalytic degradation of IC dye. With respect to total organic carbon (TOC) analysis, 68.8% total organic carbon reduction of the IC dye (10 mg/L) was observed under the same experimental conditions. The catalytic efficiency of C-dots in the photocatalytic process is explained by proposing a degradation mechanism

Comparison of the safety and efficacy of caroverine and betahistine in patients of subjective tinnitus

Background: Owing to lack of any established treatment and handicap assessment methods, subjective tinnitus can be a debilitating disorder. This study was carried out to compare the safety and efficacy of caroverine and betahistine in patients of subjective tinnitus.Methods: A total of 60 patients of subjective tinnitus were randomized into two groups and followed-up for 12 weeks using tinnitus handicap inventory (THI) questionnaire. One group received 8 mg betahistine tablet TDS for a month whereas the other group was given supervised intravenous (IV) infusion of 160 mg of caroverine dihydrochloride. Data for the safety were also recorded.Results: Both the drugs showed significant improvement in severity of symptoms at 1 week, 4 weeks and 12 weeks individually as assessed by the THI scores. The response to caroverine was significant up to 4 weeks, but it was not significant at 12 weeks; whereas the response to betahistine was significant up to 12 weeks. A total of 28 adverse drug reactions (ADRs) were reported (53.6% with caroverine, 46.4% with betahistine). 24 ADRs were mild and 4 were moderate in intensity. There was no serious adverse event.Conclusions: Both the drugs are safe and efficacious in reducing the handicap of subjective tinnitus. A single IV infusion of caroverine may suffice for 4-6 weeks, so it may be repeated after 6 weeks to maintain the relief

A case of nevirapine-induced exfoliative dermatitis in an immunocompromised patient: a case report

Nevirapine is a non-nucleoside reverse transcriptase inhibitor used as one of the first-line drugs for the highly active antiretroviral therapy (HAART) in human immunodeficiency virus positive patients. The side effects range from skin rashes to fulminant hepatotoxicity. The most of the side effects are manifested in the first 6-10 weeks indicating a need for close monitoring and follow-up of the patient in first few weeks. We hereby are presenting a case of a 41-year-old female who developed exfoliative dermatitis after 4 weeks of therapy

A study on the effectiveness of nicotine and counselling in tobacoo smoking cessation

Background: Effectiveness of pharmacotherapy and counselling has been suggested by various research workers in smoking cessation, but studies show variable results with pharmacotherapy. Also efficacy of counselling and pharmacological intervention differs from centre to centre. So we conducted this study, to observe the role of counselling and nicotine gums in our setup.Methods: 86 smokers willing to quit smoking were enrolled. Baseline counselling was provided at the time of enrolment, then at 1 week, 1 month, 3 months and at 6 months. Telephonic counselling was given to those who did not come for face to face counselling. Nicotine gums were prescribed for 3 months duration. At the end of 12 months, follow up outcome was measured.Results: At 1 week 24% smokers, at 1 month 23%, at 3 months 12% and at 6 months 33% smokers attended face to face counselling session. At 1 week 66%, at 1 month 57%, at 3 months 63% and at 6 months 59% smokers received telephonic counselling. Nicotine gums were used by only 76% smokers. Out of those who used nicotine gums, only 3% used gums for 3 months duration and 97% stopped prematurely. Among those who used gums, 29% experienced side effects. Total 22 (26%) smokers stopped smoking at 12 months.Conclusions: Less number of smokers coming for follow up counselling visits, suggest lack of motivation. Alternative counselling, like telephonic counselling, was much more accepted and was found to be helpful. Acceptance of nicotine gums was very less which also shows the lack of motivation. Abstinence rate of 26% shows that counselling and nicotine gums help in quitting smoking

Socio-demographic profile of multi-drug resistant tuberculosis patients and its association with severity of adverse drug reactions in DOTS plus centre at tertiary hospital in Himachal Pradesh, India

Background: Multi-drug resistant tuberculosis has become major public health problem and obstacle to effective control of tuberculosis. Objectives was to study the socio-demographic profile of multi- drug resistant tuberculosis patients and its association with severity of ADR (adverse drug reactions) in DOTS plus centre at tertiary hospital in Himachal Pradesh.Methods: It was a prospective observational study carried out from November 2012 to October 2013 on multi-drug resistant tuberculosis (MDR-TB) patients after approved from Institutional Ethics Committee.Results: Out of 104 patients the mean age of patients was 39.9 ±14.26 years. Majority of the patients were in the economically productive age groups. Multi-drug resistant tuberculosis was more in male (76%) than female (24%) and 96% of patients were belonged to rural area. The educational status of the MDR-TB shows 24% patients were illiterate. 63.46% MDR-TB patients were underweight (BMI<18.5%) according to WHO guidelines for obesity. Severity of ADR assessed by Hart wig and Siegel’s scale showed 21% patients experienced mild ADRs, 49% patients had moderate and 17% patients had severe ADRs. Severity of ADR is seen more in male, economically productive age group, subjects on vegetarian diet, patients who were underweight (BMI<18.5%) and with lower educational status.Conclusions: MDR-TB is a rapidly increasing health problem with major socio-economic and individual consequences. Multi-drug resistant tuberculosis mainly affects middle age that is in the economically productive age group which hampers the social and economic development of individual, society and nation

Budget impact of adding ivabradine to standard of care in patients with chronic systolic heart failure in the United States

BACKGROUND: Heart failure (HF) costs $21 billion annually in direct health care costs, 80 OBJECTIVE: To estimate the budget impact of ivabradine from a U.S. commercial payer perspective. METHODS: A budget impact model estimated the per-member-per month (PMPM) impact of introducing ivabradine to existing formularies by comparing a reference scenario (SoC) and a new drug scenario (ivabradine + SoC) in hypothetical 1 million-member commercial and Medicare Advantage plans. In both scenarios, U.S. claims data were used for the reference cumulative annual rates of hospitalizations (HF, non-HF cardiovascular [CV], and non-CV), and hospitalization rates were adjusted using SHIFT data. The model controlled for mortality risk using SHIFT and U.S. life table data, and hospitalization costs were obtained from U.S. claims data: HF-related =$37,507; non-HF CV = $28,951; and non-CV =$17,904. The annualized wholesale acquisition cost of ivabradine was $4,500, with baseline use for this new drug at 2 RESULTS: Based on the approved U.S. indication, approximately 2,000 commercially insured patients from a 1 million-member commercial plan were eligible to receive ivabradine. Ivabradine resulted in a PMPM cost savings of$0.01 and $0.04 in years 1 and 3 of the core model, respectively. After including the acquisition price for ivabradine, the model showed a decrease in total costs in the commercial ($991,256 and $474,499, respectively) and Medicare populations ($13,849,262 and $4,280,291, respectively) in year 1. This decrease was driven by ivabradine’s reduction in hospitalization rates. For the core model, the estimated pharmacy-only PMPM in year 1 was$0.01 for the commercial population and $0.24 for the Medicare Advantage population. CONCLUSIONS: Adding ivabradine to SoC led to lower average annual treatment costs. The negative PMPM budget impact indicates that ivabradine is an affordable option for U.S. payers

Antihypertensive and Antioxidant Action of Amlodipine and Vitamin C in Patients of Essential Hypertension

The etiology of essential hypertension includes increased oxidative stress. The role of antihypertensive drug amlodipine as an antioxidant and the benefit of addition of vitamin C, an antioxidant to antihypertensive therapy were studied. Forty male patients of essential hypertension were randomly divided into two groups and treated with 5 mg amlodipine. In addition one group also received 1000 mg vitamin C (as two 500 mg tablets) once daily for three months. Although blood pressure decreased in both groups, the systolic blood pressure in patients given vitamin C was less (126.4 ± 7.47) compared to the other group (130.9 ± 7.27). A decrease in malondialdehyde, an increase in erythrocyte sodium-potassium adenosine triphosphatase (Na+ K+ ATPase) and an increase in the superoxide dismutase levels were observed in both groups. The increase in SOD was statistically more in the patients given vitamin C in addition to amlodipine (0.1717 ± 0.0150 compared to 0.152 ± 0.0219 units/100 ml assay). In spite of the known antihypertensive, antioxidant activity, similarity in correcting endothelial dysfunction independently, giving the two drugs together and early introduction of vitamin C perhaps decreases oxidative stress and augments the antioxidant status. This may prevent further vascular damage due to oxidative stress, leading to a better prognosis in essential hypertension patients

Ball convergence for an Aitken-Newton method

We present a local convergence analysis of an eighth-order Aitken-Newton method for approximating a locally unique solution of a nonlinear equation. Earlier studies have shown convergence of these methods under hypotheses up to the eighth derivative of the function although only the first derivative appears in the method. In this study, we expand the applicability of these methods using only hypotheses up to the first derivative of the function. This way the applicability of these methods is extended under weaker hypotheses. Moreover, the radius of convergence and computable error bounds on the distances involved are also given in this study. Numerical examples are also presented in this study