4,729 research outputs found

    Thermochemistry of Alane Complexes for Hydrogen Storage: A Theoretical and Experimental Investigation.

    Get PDF
    Knowledge of the relative stabilities of alane (AlH(3)) complexes with electron donors is essential for identifying hydrogen storage materials for vehicular applications that can be regenerated by off-board methods; however, almost no thermodynamic data are available to make this assessment. To fill this gap, we employed the G4(MP2) method to determine heats of formation, entropies, and Gibbs free energies of formation for 38 alane complexes with NH(3-n)R(n) (R = Me, Et; n = 0-3), pyridine, pyrazine, triethylenediamine (TEDA), quinuclidine, OH(2-n)R(n) (R = Me, Et; n = 0-2), dioxane, and tetrahydrofuran (THF). Monomer, bis, and selected dimer complex geometries were considered. Using these data, we computed the thermodynamics of the key formation and dehydrogenation reactions that would occur during hydrogen delivery and alane regeneration, from which trends in complex stability were identified. These predictions were tested by synthesizing six amine-alane complexes involving trimethylamine, triethylamine, dimethylethylamine, TEDA, quinuclidine, and hexamine and obtaining upper limits of ΔG° for their formation from metallic aluminum. Combining these computational and experimental results, we establish a criterion for complex stability relevant to hydrogen storage that can be used to assess potential ligands prior to attempting synthesis of the alane complex. On the basis of this, we conclude that only a subset of the tertiary amine complexes considered and none of the ether complexes can be successfully formed by direct reaction with aluminum and regenerated in an alane-based hydrogen storage system

    The clinical profile and respiratory ciliary assessment in Kartageners syndrome

    Get PDF
    published_or_final_versio

    Evaluation of Hylleraas-CI atomic integrals by integration over the coordinates of one electron. IV. An improved algorithm for three-electron kinetic energy integrals

    Full text link
    An improved algorithm to evaluate the nonrelativistic three-electron Hylleraas-Configuration Interaction (Hy-CI) kinetic energy integrals over Slater orbitals and the Hamiltonian in Hylleraas coordinates is shown. The resulting analytical expressions are general for all quantum numbers of the orbitals. From there, the restriction of employing orbitals with quantum numbers l≀2l \le 2 of the above algorithm presented in paper I of this series has been removed. With the new algorithm it is possible, in the direct integration method described in this series, to carry out Hy-CI atomic structure calculations including ff-, gg-, 
\ldots , ll and higher angular-momentum Slater orbitals and to determine FF, GG, 
\ldots , LL and states of higher order symmetry.Comment: 32 pages, 14 references, 1 figure and 1 table, Journal of Mathematical Chemistry, January 201

    Costs associated with febrile neutropenia in solid tumor and lymphoma patients - an observational study in Singapore.

    Get PDF
    BackgroundThe primary objective was to describe the total direct inpatient costs among solid tumor and lymphoma patients with chemotherapy-induced febrile neutropenia (FN) and the factors that were associated with higher direct cost. The secondary objective was to describe the out-of-pocket patient payments and the factors that were associated with higher out-of-pocket patient payments.MethodsThis was a single-center observational study conducted at the largest cancer center in Singapore. All of the adult cancer patients hospitalized due to FN from 2009 to 2012 were studied. The primary outcomes were the total hospital cost and the out-of-pocket patient payments (adjusted by government subsidy) per FN episode. Univariate analysis and multiple linear regression were conducted to identify the factors associated with higher FN costs.ResultsThree hundred and sixty seven adult cancer patients were documented with FN-related hospitalizations. The mean total hospital cost was US4,193(954,193 (95% CI: US3,779-4,607) and the mean out-of-pocket patient payment was US2,230(952,230 (95% CI: US1,976-2,484), per FN episode. The factors associated with a higher total hospital cost were longer length of stay, severe sepsis, and lymphoma as underlying cancer. The out-of-pocket patient payment was positively associated with longer length of stay, severe sepsis, lymphoma diagnosed as underlying cancer, the therapeutic use of granulocyte colony-stimulating factor (GCSF), the private ward class, and younger patients.ConclusionsThe total hospital cost and out-of-pocket patient payments of FN management in lymphoma cases were substantial compared with other solid tumors. Factors associated with a higher FN management cost may be useful for developing appropriate strategies to reduce the cost of FN for cancer patients

    Computational analysis of image-based drug profiling predicts synergistic drug combinations: Applications in triple-negative breast cancer

    Full text link
    © 2014 Federation of European Biochemical Societies. An imaged-based profiling and analysis system was developed to predict clinically effective synergistic drug combinations that could accelerate the identification of effective multi-drug therapies for the treatment of triple-negative breast cancer and other challenging malignancies. The identification of effective drug combinations for the treatment of triple-negative breast cancer (TNBC) was achieved by integrating high-content screening, computational analysis, and experimental biology. The approach was based on altered cellular phenotypes induced by 55 FDA-approved drugs and biologically active compounds, acquired using fluorescence microscopy and retained in multivariate compound profiles. Dissimilarities between compound profiles guided the identification of 5 combinations, which were assessed for qualitative interaction on TNBC cell growth. The combination of the microtubule-targeting drug vinblastine with KSP/Eg5 motor protein inhibitors monastrol or ispinesib showed potent synergism in 3 independent TNBC cell lines, which was not substantiated in normal fibroblasts. The synergistic interaction was mediated by an increase in mitotic arrest with cells demonstrating typical ispinesib-induced monopolar mitotic spindles, which translated into enhanced apoptosis induction. The antitumour activity of the combination vinblastine/ispinesib was confirmed in an orthotopic mouse model of TNBC. Compared to single drug treatment, combination treatment significantly reduced tumour growth without causing increased toxicity. Image-based profiling and analysis led to the rapid discovery of a drug combination effective against TNBC invitro and invivo, and has the potential to lead to the development of new therapeutic options in other hard-to-treat cancers

    OXSR1 inhibits inflammasome activation by limiting potassium efflux during mycobacterial infection.

    Get PDF
    Pathogenic mycobacteria inhibit inflammasome activation to establish infection. Although it is known that potassium efflux is a trigger for inflammasome activation, the interaction between mycobacterial infection, potassium efflux, and inflammasome activation has not been investigated. Here, we use Mycobacterium marinum infection of zebrafish embryos and Mycobacterium tuberculosis infection of THP-1 cells to demonstrate that pathogenic mycobacteria up-regulate the host WNK signalling pathway kinases SPAK and OXSR1 which control intracellular potassium balance. We show that genetic depletion or inhibition of OXSR1 decreases bacterial burden and intracellular potassium levels. The protective effects of OXSR1 depletion are at least partially mediated by NLRP3 inflammasome activation, caspase-mediated release of IL-1ÎČ, and downstream activation of protective TNF-α. The elucidation of this druggable pathway to potentiate inflammasome activation provides a new avenue for the development of host-directed therapies against intracellular infections

    Heritage branding orientation: The case of Ach. Brito and the dynamics between corporate and product heritage brands

    Get PDF
    The notion of heritage branding orientation is introduced and explicated. Heritage branding orientation is designated as embracing both product and corporate brands and differs from corporate heritage brand orientation which has an explicit corporate focus. Empirical insights are drawn from an in-depth and longitudinal case study of Ach. Brito, a celebrated Portuguese manufacturer of soaps and toiletries. This study shows how, by the pursuance of a strategy derived from a heritage branding orientation Ach. Brito – after a prolonged period of decline – achieved a dramatic strategic turnaround. The findings reveal how institutional heritage can be a strategic resource via its adoption and activation at both the product and corporate levels. Moreover, the study showed how the bi-lateral interplay between product and corporate brand levels can be mutually reinforcing. In instrumental terms, the study shows how heritage can be activated and articulated in different ways. For instance, it can re-position both product and/or corporate brands; it can be meaningfully informed by product brand heritage and shape corporate heritage; and can be of strategic importance to both medium-sized and small enterprises

    A qualitative study of the views of patients with long-term conditions on family doctors in Hong Kong

    Get PDF
    <b>Background</b> Primary care based management of long-term conditions (LTCs) is high on the international healthcare agenda, including the Asia-Pacific region. Hong Kong has a 'mixed economy' healthcare system with both public and private sectors with a range of types of primary care doctors. Recent Hong Kong Government policy aims to enhance the management of LTCs in primary care possibly based on a 'family doctor' model. Patients' views on this are not well documented and the aim of the present study was to explore the views of patients with LTCs on family doctors in Hong Kong.<p></p> <b>Methods</b> The views of patients (with a variety of LTCs) on family doctors in Hong Kong were explored. Two groups of participants were interviewed; a) those who considered themselves as having a family doctor, b) those who considered themselves as not having a family doctor (either with a regular primary care doctor but not a family doctor or with no regular primary care doctor). In-depth individual semi-structured interviews were carried out with 28 participants (10 with a family doctor, 10 with a regular doctor, and 8 with no regular doctor) and analysed using the constant comparative method.<p></p> <b>Results</b> Participants who did not have a family doctor were familiar with the concept but regarded it as a 'luxury item' for the rich within the private healthcare system. Those with a regular family doctor (all private) regarded having one as important to their and their family's health. Participants in both groups felt that as well as the more usual family medicine specialist or general practitioner, traditional Chinese medicine practitioners also had the potential to be family doctors. However most participants attended the public healthcare system for management of their LTCs whether they had a family doctor or not. Cost, perceived need, quality, trust, and choice were all barriers to the use of family doctors for the management of their LTCs.<p></p> <b>Conclusions</b> Important barriers to the adoption of a 'family doctor' model of management of LTCs exist in Hong Kong. Effective policy implementation seems unlikely unless these complex barriers are addressed

    Attitudes and perceptions towards hypoglycaemia in patients with diabetes mellitus: A multinational cross-sectional study

    Get PDF
    BACKGROUND: Preventing hypoglycaemia is an essential component of diabetes self-management that is affected by patients' attitudes and perceptions. This study aimed to explore the hypoglycaemia problem-solving ability of patients who have diabetes mellitus and factors that determine their attitudes and perceptions towards their previous events. METHODOLOGY: A cross-sectional study was conducted between October 2017 and May 2018 in three Arab countries (Jordan, Saudi Arabia and Kuwait) in patients with diabetes mellitus, who were prescribed antidiabetic therapy and had experienced hypoglycaemic events in the past six months. The Hypoglycaemia Problem-Solving Scale was used in this study. This scale contains two subscales, problem orientation (six questions) and problem-solving skills (eighteen questions), using a five-point Likert scale (range 0-4). Multiple linear regression analysis was used to identify predictors of hypoglycaemia problem-solving abilities. RESULTS: A total of 895 patients participated in this study from the three countries (300 in Jordan, 302 in Saudi Arabia, and 293 in Kuwait). The average age of the patients was 53.5 years (standard deviation = 13.7) and 52.4% (n = 469) were males. Patients had moderate overall problem-solving ability with a median score of 63.00 (interquartile range = 13.00). Patients' problem-solving skills score (68.1%) was better than their problem-orientation skills score (58.3%). The highest sub-scale scores were for detection control, setting problem-solving goals, and evaluating strategies, 75.0%. The lowest sub-scale score was for problem-solving perception and immediate management, 50.0%. Older age, being educated, being married, having T2DM, prescribed insulin therapy, and not having been admitted to hospital for hypoglycaemia were important predictors of patients' problem-solving ability (p < 0.05). CONCLUSIONS: Healthcare professionals are advised to provide more education to patients on how to self-manage hypoglycaemic events. Specifically, they should focus on the overall problem-solving perception of hypoglycaemia and its immediate management
    • 

    corecore