151 research outputs found

    Automated mechanism design for B2B e-commerce models

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    Business-to-business electronic marketplaces (B2B e-Marketplaces) have been in the limelight since 1999 with the commercialisation of the Internet and subsequent “dot.com” boom [1]. Literature is indicative of the growth of the B2B sectors in all industries, and B2B e-Marketplace is one of the sectors that have witnessed a rapid increase. Consequently, the importance of developing the B2B e-Commerce Model for improved value chain in B2B exchanges is extremely important for SMEs to expose to the world marketplace. There are three research objectives (ROs) in this study; first (RO1) to critical review the concepts of the B2B e-Marketplace including their technologies, operations, business relationships and functionalities; second (RO2) to design an automated mechanism of B2B e-Marketplace for Small to Medium Sized Enterprises (SMEs); and third (RO3) to propose a conceptual B2B e-Commerce model for SMEs. The proposed model is constructed by the analytical findings obtained from the contemporary B2B e-Marketplace literature

    Socioeconomic position and use of hospital-based care towards the end of life: a mediation analysis using the English Longitudinal Study of Ageing

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    © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license Background: Many patients prefer to avoid hospital-based care towards the end of life, yet hospitalisation is common and more likely for people with low socioeconomic position. The reasons underlying this socioeconomic inequality are not well understood. This study investigated health, service access, and social support as potential mediating pathways between socioeconomic position and receipt of hospital-based care towards the end of life. Methods: For this observational cohort study, we included deceased participants from the nationally representative English Longitudinal Study of Ageing of people aged 50 years or older in England. We used a multiple mediation model with age-adjusted and gender-adjusted probit regression to estimate the direct effect of socioeconomic position (measured by wealth and education) on death in hospital and three or more hospital admissions in the last 2 years of life, and the indirect effects of socioeconomic position via three mediators: health and function, access to health-care services, and social support. Findings: 737 participants were included (314 [42·6%] female, 423 [57·4%] male), with a median age at death of 78 years (IQR 71–85). For death in hospital, higher wealth had a direct negative effect (probit coefficient −0·16, 95% CI −0·25 to −0·06), which was not mediated by any of the pathways tested. For frequent hospital admissions, health and function mediated the effect of wealth (−0·04, −0·08 to −0·01), accounting for 34·6% of the total negative effect of higher wealth (−0·13, −0·23 to −0·02). Higher wealth was associated with better health and function (0·25, 0·18 to 0·33). Education was associated with the outcomes only indirectly via wealth. Interpretation: Our findings suggest that worse health and function could partly explain why people with lower wealth have more hospital admissions, highlighting the importance of socioeconomically driven health differences in explaining patterns of hospital use towards the end of life. The findings should raise awareness about the related risk factors of low wealth and worse health for patients approaching the end of life, and strengthen calls for resource allocation to be made on the basis of health need and socioeconomic profile. Funding: Dunhill Medical Trust Fellowship Grant (RTF74/0116)

    Polymer nanocomposites functionalised with nanocrystals of zeolitic imidazolate frameworks as ethylene control agents

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    Ethylene (C2H4) management involves the usage of materials such as KMnO4 or processes such as ozone oxidation or combined photocatalysis/photochemistry. The ubiquity of C2H4, especially in an industrial context, necessitates a simpler and much more effective approach, and herein we propose the usage of tuneable polymer nanocomposites for the adsorption of C2H4 through the modification of the polymer matrices via the incorporation of nanocrystals of zeolitic imidazolate frameworks (nano-ZIFs). We demonstrate that the inclusion of ZIF-8 and ZIF-7 nanocrystals into polymeric matrices (Matrimid and polyurethane [PU]) yields robust nanocomposites that preserve the C2H4 adsorption/desorption capacity of nanocrystals while shielding it from degrading factors. We report new insights into the adsorption/desorption kinetics of the polymer and its corresponding nanocomposites, which can be tailored by exploiting the underlying polymeric molecular interactions. Importantly, we also elucidated the retention of the intrinsic structural framework dynamics of the nano-ZIFs even when embedded within the polymeric matrix, as evidenced from the breathing and gate-opening phenomena. Our findings pave the way for bespoke designs of novel polymer nanocomposites, which will subsequently impact the deployment of tailored nanomaterials for effective industrial applications.E. M. Mahdi would like to thank Yayasan Khazanah (YK) for the DPhil scholarship that made this work possible. The research in the MMC Lab (J.C.T.) was supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 771575 - PROMOFS), and the EPSRC grant no. EP/N014960/1. The authors acknowledge the provision of the TGA and TEM by the Research Complex at Harwell (RCaH), in Rutherford Appleton Laboratory, Oxfordshire. J.S.A. acknowledges financial support by MINECO (Project MAT2016-80285-p), H2020 (MSCA-RISE-2016/NanoMed Project), and GV (PROMETEOII/2014/004)

    Association between plasma neutrophil gelatinase-associated lipocalin and cardiac disease hospitalizations and deaths in older women

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    Background Neutrophil gelatinase-associated lipocalin ( NGAL ) or lipocalin 2 may promote atherosclerosis and plaque instability leading to increased risk of cardiac events. We investigated the relationships between plasma NGAL , cardiovascular disease biomarkers, and long-term cardiac events. Methods and Results The study population consisted of 1131 ambulant older white women (mean age 75 years) without clinical coronary heart disease ( CHD ) and measures of plasma NGAL in the Perth Longitudinal Study of Ageing Women with 14.5-year CHD and heart failure hospitalizations or death (events) captured using linked records. Over 14.5 years, 256 women had CHD events, while 118 had heart failure events. Per SD increase in log-transformed NGAL there was a 35% to 37% increase in relative hazards for CHD and heart failure events in unadjusted analyses, which remained significant after adjustment for conventional risk factors for CHD events (hazard ratio 1.29, 95% CI 1.13-1.48, P0.05). Women in the highest 2 quartiles of NGAL had higher relative hazards for CHD events compared with women in the lowest quartile hazard ratio 1.61, 95% CI 1.08-2.39, P=0.019 and hazard ratio 1.97, 95% CI 1.33-3.93, P=0.001, respectively. These associations were independent of high-sensitivity cardiac troponin I, homocysteine, and estimated renal function. NGAL correctly reclassified 1 in 4 women who sustained a CHD event up in risk and 1 in 10 women without CHD events down in risk. Conclusions NGAL was associated with increased risk of long-term CHD events, independent of conventional risk factors and biomarkers. These findings provide mechanistic insight into the role of NGAL with cardiac events

    Lepton flavor violating signals of a little Higgs model at the high energy linear e+e−e^{+}e^{-} colliders

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    Littlest Higgs (LH)(LH) model predicts the existence of the doubly charged scalars Ί±±\Phi^{\pm\pm}, which generally have large flavor changing couplings to leptons. We calculate the contributions of Ί±±\Phi^{\pm\pm} to the lepton flavor violating (LFV)(LFV) processes li→ljÎłl_{i}\to l_{j}\gamma and li→ljlklkl_{i}\to l_{j}l_{k}l_{k}, and compare our numerical results with the current experimental upper limits on these processes. We find that some of these processes can give severe constraints on the coupling constant YijY_{ij} and the mass parameter MΊM_{\Phi}. Taking into account the constraints on these free parameters, we further discuss the possible lepton flavor violating signals of Ί±±\Phi^{\pm\pm} at the high energy linear e+e−e^{+}e^{-} collider (ILC)(ILC) experiments. Our numerical results show that the possible signals of Ί±±\Phi^{\pm\pm} might be detected via the subprocesses e±e±→l±l±e^{\pm}e^{\pm}\to l^{\pm}l^{\pm} in the future ILCILC experiments.Comment: 16 pages, 7 figures. Discussions and references added, typos correcte

    Characterization of anticoagulant heparinoids by immunoprofiling

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    Heparinoids are used in the clinic as anticoagulants. A specific pentasaccharide in heparinoids activates antithrombin III, resulting in inactivation of factor Xa and–when additional saccharides are present–inactivation of factor IIa. Structural and functional analysis of the heterogeneous heparinoids generally requires advanced equipment, is time consuming, and needs (extensive) sample preparation. In this study, a novel and fast method for the characterization of heparinoids is introduced based on reactivity with nine unique anti-heparin antibodies. Eight heparinoids were biochemically analyzed by electrophoresis and their reactivity with domain-specific anti-heparin antibodies was established by ELISA. Each heparinoid displayed a distinct immunoprofile matching its structural characteristics. The immunoprofile could also be linked to biological characteristics, such as the anti-Xa/anti-IIa ratio, which was reflected by reactivity of the heparinoids with antibodies HS4C3 (indicative for 3-O-sulfates) and HS4E4 (indicative for domains allowing anti-factor IIa activity). In addition, the immunoprofile could be indicative for heparinoid-induced side-effects, such as heparin-induced thrombocytopenia, as illustrated by reactivity with antibody NS4F5, which defines a very high sulfated domain. In conclusion, immunoprofiling provides a novel, fast, and simple methodology for the characterization of heparinoids, and allows high-throughput screening of (new) heparinoids for defined structural and biological characteristics

    Survival among older adults with kidney failure is better in the first three years with chronic dialysis treatment than not

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    Comparisons of survival between dialysis and nondialysis care for older adults with kidney failure have been limited to those managed by nephrologists, and are vulnerable to lead and immortal time biases. So we compared time to all-cause mortality among older adults with kidney failure treated vs. not treated with chronic dialysis. Our retrospective cohort study used linked administrative and laboratory data to identify adults aged 65 or more years of age in Alberta, Canada, with kidney failure (2002-2012), defined by two or more consecutive outpatient estimated glomerular filtration rates less than 10 mL/min/1.73m2, spanning 90 or more days. We used marginal structural Cox models to assess the association between receipt of dialysis and all-cause mortality by allowing control for both time-varying and baseline confounders. Overall, 838 patients met inclusion criteria (mean age 79.1; 48.6% male; mean estimated glomerular filtration rate 7.8 mL/min/1.73m2). Dialysis treatment (vs. no dialysis) was associated with a significantly lower risk of death for the first three years of follow-up (hazard ratio 0.59 [95% confidence interval 0.46-0.77]), but not thereafter (1.22 [0.69-2.17]). However, dialysis was associated with a significantly higher risk of hospitalization (1.40 [1.16-1.69]). Thus, among older adults with kidney failure, treatment with dialysis was associated with longer survival up to three years after reaching kidney failure, though with a higher risk of hospital admissions. These findings may assist shared decision-making about treatment of kidney failure

    COL4A2 is associated with lacunar ischemic stroke and deep ICH: Meta-analyses among 21,500 cases and 40,600 controls

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    Objective: To determine whether common variants in familial cerebral small vessel disease (SVD) genes confer risk of sporadic cerebral SVD. Methods: We meta-analyzed genotype data from individuals of European ancestry to determine associations of common single nucleotide polymorphisms (SNPs) in 6 familial cerebral SVD genes (COL4A1, COL4A2, NOTCH3, HTRA1, TREX1, and CECR1) with intracerebral hemorrhage (ICH) (deep, lobar, all; 1,878 cases, 2,830 controls) and ischemic stroke (IS) (lacunar, cardioembolic, large vessel disease, all; 19,569 cases, 37,853 controls). We applied data quality filters and set statistical significance thresholds accounting for linkage disequilibrium and multiple testing. Results: A locus in COL4A2 was associated (significance threshold p , 3.5 3 1024) with both lacunar IS (lead SNP rs9515201: odds ratio [OR] 1.17, 95%confidence interval [CI] 1.11-1.24, p 56.62 31028) and deep ICH (lead SNP rs4771674: OR 1.28, 95%CI 1.13-1.44, p 55.76 3 1025). A SNP in HTRA1 was associated (significance threshold p , 5.5 3 1024) with lacunar IS (rs79043147: OR 1.23, 95%CI 1.10-1.37, p 5 1.90 3 1024) and less robustly with deep ICH. There was no clear evidence for association of common variants in either COL4A2 or HTRA1 with non-SVD strokes or in any of the other genes with any stroke phenotype

    The phenotype of Floating-Harbor syndrome: Clinical characterization of 52 individuals with mutations in exon 34 of SRCAP

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    Background: Floating-Harbor syndrome (FHS) is a rare condition characterized by short stature, delays in expressive language, and a distinctive facial appearance. Recently, heterozygous truncating mutations in SRCAP were determined to be disease-causing. With the availability of a DNA based confirmatory test, we set forth to define the clinical features of this syndrome. Methods and results. Clinical information on fifty-two individuals with SRCAP mutations was collected using standardized questionnaires. Twenty-four males and twenty-eight females were studied with ages ranging from

    Serum magnesium and calcium levels in relation to ischemic stroke : Mendelian randomization study

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    ObjectiveTo determine whether serum magnesium and calcium concentrations are causally associated with ischemic stroke or any of its subtypes using the mendelian randomization approach.MethodsAnalyses were conducted using summary statistics data for 13 single-nucleotide polymorphisms robustly associated with serum magnesium (n = 6) or serum calcium (n = 7) concentrations. The corresponding data for ischemic stroke were obtained from the MEGASTROKE consortium (34,217 cases and 404,630 noncases).ResultsIn standard mendelian randomization analysis, the odds ratios for each 0.1 mmol/L (about 1 SD) increase in genetically predicted serum magnesium concentrations were 0.78 (95% confidence interval [CI] 0.69-0.89; p = 1.3 7 10-4) for all ischemic stroke, 0.63 (95% CI 0.50-0.80; p = 1.6 7 10-4) for cardioembolic stroke, and 0.60 (95% CI 0.44-0.82; p = 0.001) for large artery stroke; there was no association with small vessel stroke (odds ratio 0.90, 95% CI 0.67-1.20; p = 0.46). Only the association with cardioembolic stroke was robust in sensitivity analyses. There was no association of genetically predicted serum calcium concentrations with all ischemic stroke (per 0.5 mg/dL [about 1 SD] increase in serum calcium: odds ratio 1.03, 95% CI 0.88-1.21) or with any subtype.ConclusionsThis study found that genetically higher serum magnesium concentrations are associated with a reduced risk of cardioembolic stroke but found no significant association of genetically higher serum calcium concentrations with any ischemic stroke subtype
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