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

Challenges of “Reverse” Aortic Arch Debranching for Repair of the Ascending Aorta by Thoracic Endovascular Aortic Repair

IntroductionAscending aortic pathology presents a unique challenge for treatment by thoracic endovascular aortic repair (TEVAR), because of lack of adequate endograft landing zones. This report describes a unique “reverse” extra-anatomical aortic arch debranching procedure performed to enable TEVAR of the ascending aorta.ReportA 71-year-old male presented with a large ascending aortic pseudoaneurysm secondary to previous arch repair anastomosis. This pathology was treated by TEVAR of the ascending aorta. To create a sufficient landing zone for the endovascular stent graft, a “reverse” extra-anatomical aortic arch debranching procedure was performed. This involved a left subclavian artery to left carotid artery bypass, left to right carotid-to-carotid bypass, ligation of proximal left common carotid artery, and embolization of the innominate artery origin.DiscussionTEVAR of the ascending aorta can be made feasible through a novel debranching procedure that creates sufficient landing zones for the endograft. This surgical approach may prove useful in patients who present with aortic arch pathology and comorbidities that prevent open surgical repair

Exponential decay in one-dimensional Type II/III thermoelasticity with two porosities

In this paper we consider the theory of thermoelasticity with a double porosity structure in the context of the Green-Naghdi types II and III heat conduction models. For the type II, the problem is given by four hyperbolic equations and it is conservative (there is no energy dissipation). We introduce in the system a couple of dissipation mechanisms in order to obtain the exponential de- cay of the solutions. To be precise, we introduce a pair of the following damping mechanisms: viscoelasticity, viscoporosities and thermal dissipation. We prove that the system is exponentially stable in three different scenarios: viscoporosity in one structure jointly with thermal dissipation, viscoporosity in each structure, and viscoporosity in one structure jointly with viscoelasticity. However, if viscoelasticity and thermal dissipation are considered together, undamped solutions can be obtained.Peer ReviewedPostprint (author's final draft

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

Enteral Nutrition in Crohn’s Disease: An Underused Therapy

This paper reviews the literature on the history, efficacy, and putative mechanism of action of enteral nutrition for inflammatory bowel disease in both paediatric and adult patients. It also analyses the reasoning behind the low popularity of exclusive enteral nutrition in clinical practice despite the benefits and safety profile

Benchside to Bedside: The Launching of a Novel Bone Healing Agent

poster abstractThe ability to evolve a nascent idea into a successful entity requires navigation through a number of perils known to debilitate new ventures. Embryonic firms (or ideas) require sufficient development; from establishing an unambiguous approach, to attaining the necessary capital for evolution and growth, to fostering an environment and market for the idea or product. In the venture community, there are a number of advocates who possess the ability to contribute to new ventures (e.g. venture community support functions, venture capitalists, or informal contributors), and these individuals help navigate the startup or idea through inception to effectuation. Academic faculty, though, who often are not engrained into the local venture community, are frequently disadvantaged because their ideas or new firms come as an ancillary to their primary work. Already potentially impeded by the challenges presented by the legal constraints of providing sufficient equity for ideas to the university, developing a clear, effective path to market can be difficult for academic faculty. In addition to the systemic uncertainty, difficulty, and impediments faced by all entrepreneurs, academic faculty are constrained by limited time, funding, experience, and other resources – all related to their inclusion in the university or system. In order to alleviate these constraints and propel cutting-edge scientific breakthroughs and technological development, Innovation-to-Enterprise Central (ITEC) was initiated to assist academic faculties’ developments into the market – where, ultimately, these products will have the greatest utility to society. Osetofuse is an embryonic firm in the nascent stages of conceptualizing a revolutionary new product, which uses thrombopoietin as a novel bone healing agent. Through the ITEC program, Osteofuse has been able to facilitate the exploration of the potential value (clinically, economically, and societally) of its research and how the initial idea can be developed into a commercialized and monetized product. In the process, it has developed mechanisms to gauge the market’s acceptance of the product, the intellectual property and legal issue constraints facing the idea, potential commercialization streams and related valuations for marketization, and a quantitative analysis of projected revenue provisions. ITEC fosters continual compounding of knowledge capacity, as the trajectory of Osteofuse has not only inclined, but redirected because of specific uncovered data and insight from the program. As a result, Osteofuse has undergone dramatic transformation; in terms of both its formal identity and the potential approach to the market

Estimating the population health impact of a multi-cancer early detection genomic blood test to complement existing screening in the US and UK

Background: Multi-cancer early detection (MCED) next-generation-sequencing blood tests represent a potential paradigm shift in screening. Methods: We estimated the impact of screening in the US and UK. We used country-specific parameters for uptake, and test-specific sensitivity and false-positive rates for current screening: breast, colorectal, cervical and lung (US only) cancers. For the MCED test, we used cancer-specific sensitivities by stage. Outcomes included the true-positive:false-positive (TP:FP) ratio; and the cost of diagnostic investigations among screen positives, per cancer detected (Diagcost). Outcomes were estimated for recommended screening only, and then when giving the MCED test to anyone without cancer detected by current screening plus similarly aged adults ineligible for recommended screening. Results: In the US, current screening detects an estimated 189,498 breast, cervical, colorectal and lung cancers. An MCED test with 25–100% uptake detects an additional 105,526–422,105 cancers (multiple types). The estimated TP:FP (Diagcost) was 1.43 ($89,042) with current screening but only 1:1.8 ($7060) using an MCED test. For the UK the corresponding estimates were 1:18 (£10,452) for current screening, and 1:1.6 (£2175) using an MCED test. Conclusions: Adding an MCED blood test to recommended screening can potentially be an efficient strategy. Ongoing randomised studies are required for full efficacy and cost-effectiveness evaluations

Challenges and opportunities associated with waste management in India

India faces major environmental challenges associated with waste generation and inadequate waste collection, transport, treatment and disposal. Current systems in India cannot cope with the volumes of waste generated by an increasing urban population, and this impacts on the environment and public health. The challenges and barriers are significant, but so are the opportunities. This paper reports on an international seminar on ‘Sustainable solid waste management for cities: opportunities in South Asian Association for Regional Cooperation (SAARC) countries’ organized by the Council of Scientific and Industrial Research-National Environmental Engineering Research Institute and the Royal Society. A priority is to move from reliance on waste dumps that offer no environmental protection, to waste management systems that retain useful resources within the economy. Waste segregation at source and use of specialized waste processing facilities to separate recyclable materials has a key role. Disposal of residual waste after extraction of material resources needs engineered landfill sites and/or investment in waste-to-energy facilities. The potential for energy generation from landfill via methane extraction or thermal treatment is a major opportunity, but a key barrier is the shortage of qualified engineers and environmental professionals with the experience to deliver improved waste management systems in India

Conservation and immunogenicity of novel antigens in diverse isolates of enterotoxigenic Escherichia coli

BACKGROUND:Enterotoxigenic Escherichia coli (ETEC) are common causes of diarrheal morbidity and mortality in developing countries for which there is currently no vaccine. Heterogeneity in classical ETEC antigens known as colonization factors (CFs) and poor efficacy of toxoid-based approaches to date have impeded development of a broadly protective ETEC vaccine, prompting searches for novel molecular targets. METHODOLOGY:Using a variety of molecular methods, we examined a large collection of ETEC isolates for production of two secreted plasmid-encoded pathotype-specific antigens, the EtpA extracellular adhesin, and EatA, a mucin-degrading serine protease; and two chromosomally-encoded molecules, the YghJ metalloprotease and the EaeH adhesin, that are not specific to the ETEC pathovar, but which have been implicated in ETEC pathogenesis. ELISA assays were also performed on control and convalescent sera to characterize the immune response to these antigens. Finally, mice were immunized with recombinant EtpA (rEtpA), and a protease deficient version of the secreted EatA passenger domain (rEatApH134R) to examine the feasibility of combining these molecules in a subunit vaccine approach. PRINCIPAL FINDINGS:EtpA and EatA were secreted by more than half of all ETEC, distributed over diverse phylogenetic lineages belonging to multiple CF groups, and exhibited surprisingly little sequence variation. Both chromosomally-encoded molecules were also identified in a wide variety of ETEC strains and YghJ was secreted by 89% of isolates. Antibodies against both the ETEC pathovar-specific and conserved E. coli antigens were present in significantly higher titers in convalescent samples from subjects with ETEC infection than controls suggesting that each of these antigens is produced and recognized during infection. Finally, co-immunization of mice with rEtpA and rEatApH134R offered significant protection against ETEC infection. CONCLUSIONS:Collectively, these data suggest that novel antigens could significantly complement current approaches and foster improved strategies for development of broadly protective ETEC vaccines