2,535 research outputs found

    Novel hybrid organic/inorganic single-sited catalysts and supports for fine chemical and pharmaceutical intermediate synthesis

    Get PDF
    The study of catalysis is a fundamental aspect of chemical engineering, as its implications affect all chemical transformations. Traditionally, catalysis has been subdivided into two areas: homogeneous and heterogeneous catalysis. Homogeneous catalysis refers to single-sited catalysts that exist in the same phase as the reaction media. These catalysts tend to be highly active and selective but often difficult to recover and reuse. In contrast, heterogeneous catalysts are typically multi-sited catalysts that exist in a different phase from the reaction media. These catalysts tend to be less active and selective than their homogeneous counterparts. However, the vast majority of industrial scale catalysts are heterogeneous because they can be easily separated, making them easily implemented in continuous processes, allowing for efficient, large scale operations. Due to the limitations of traditional homogeneous and heterogeneous catalysts, researchers have increasingly investigated hybrid catalysts that incorporate aspects of homogeneous and heterogeneous catalysis. This is accomplished via immobilization of homogeneous catalyst analogues onto solid-phase supports, thereby preserving the activity and selectivity of homogeneous catalysts while allowing for facile recovery and reuse from the insoluble, heterogeneous support. A variety of systems is presented here including organic and organometallic catalysts immobilized on organic and inorganic supports. Five cases are included. The first discusses utilization of supported acid and base catalysts for use in one-pot cascade reactions. The second example illustrates use of silica-coated magnetic nanoparticle supported acid catalysts for organic transformations. The third case presents novel polymer brush supported Cobalt-salen catalysts for the enantioselective, hydrolytic kinetic resolution of epoxides. A fourth case presents novel, magnetic polymer brush supported organic and organometallic catalysts for organic transformations. The fifth example illustrates polymer and silica supported ruthenium-salen catalysts for the asymmetric cyclopropanation of olefins. The overall goal of this thesis work is to develop novel supports and immobilization techniques to advance the field of hybrid organic/inorganic catalysts for the production of fine chemical and pharmaceutical intermediates.Ph.D.Committee Chair: Jones, Christopher; Committee Member: Agrawal, Pradeep; Committee Member: Teja, Amyn; Committee Member: Weck, Marcus; Committee Member: Zhang, Joh

    THE CONTRIBUTION OF HIP STRENGTH TO HIP ADDUCTION DURING RUNNING IS INFLUENCED BY STEP RATE, ANKLE DORSIFLEXION AND INJURY STATUS

    Get PDF
    Peak hip adduction angle is frequently associated with running related injuries. The purpose of this study was to identify how clinical assessment measures interact to determine the presence of high or low peak hip adduction angles during running. A mixed sex sample of runners (n=125) comprising both injured and healthy controls were assessed for hip abduction strength and range of movement of the hip and ankle. Each runner then ran on a treadmill whilst 3D kinematic data was recorded, with peak hip adduction angles isolated from the data. All interest variables were analysed using a classification and regression tree procedure. This produced a model which was able to classify runners with either high or low peak hip adduction angles with an accuracy of 83.2%. The contribution of hip abductor strength to peak hip adduction angles was influenced by step rate, ankle dorsiflexion range of movement and injury status. This adds to our understanding of the relationship between hip strength and peak hip adduction

    Online virtual fit is not yet fit for purpose: An analysis of fashion e-commerce interfaces

    Get PDF
    To unify the methodology of Virtual Fit platforms and allowing cross platform integration of 3D Body Scanning, the current Virtual Fit platforms need to be assessed in terms of their size recommendation approach and user interaction. Digital data, interactivity, and internet technology are changing the ways we interact in online shopping, with the Virtual Fit platforms having great potential to increase retail engagement and market share. This will support online purchasing activities while minimising the perceived risk in garment returns due to the poor sizing fit information. Current research has focused on the analysis of computer modelling techniques, avatars, cloth, fabric draping simulations, and customer behaviour / aesthetic impact in the online domain. From a technical perspective, these investigations offer an interesting insight, although do not address issues of implementation or customer attitude. Therefore, to judge the current and potential impact of such technologies, it is important to understand 1) how they are being enacted online, 2) the Interaction Design elements of the user journey, 3) the application (or lack thereof) of mathematical models, and 4) how such interfaces are embedded within websites. Once these four key questions have been answered a greater understanding of how 3D Body Scanning and Technologies integrated into eCommerce and Virtual Fit platforms in the consumer market may be reached. Through analysis of nine leading Virtual Fit platforms, the persona of a single female dress form was used to work through the customer journey. Through this, screen shot data captured along each stage in relation to the four research questions listed above. Following this, the study utilised content analysis structure with NVivo as a qualitative thematic analysis tool. This study found that despite a large number of platforms using virtual fit technology, only a handful companies exist that provide such technology and interfaces; often based upon subjective ‘previous purchases’ rather than scientific prediction. This issue is made more complicated in how subjective measures such as personal perception of one’s body is required (e.g. what size are you), besides body shape; a concept shown to be ‘broken’ and not fit-for-purpose. In addition, many of the technologies use limited and often misinterpreted body measurements, the impact of which is explored in greater detail within the paper. This study contributes to the understanding of the information required from users by virtual fit platforms, and the understanding of the output as presented by virtual fit platforms. The research goal is to contribute to knowledge as a potential guideline for any future projects in virtual fit and to help direct body scanning developments to better support these platforms

    Statistical characteristics of finger-tapping data in Huntington’s disease

    Get PDF
    Measuring the rate of finger tapping is a technique commonly used as an indicator of impairment in degenerative neurological conditions, such as Huntington’s disease. The information it provides can be greatly enhanced by analysing not simply the overall tapping rate, but also the statistical characteristics of the individual times between each successive response. Recent technological improvements in the recording equipment allow the responses to be analysed extremely quickly, and permit modification of the task in the interest of greater clinical specificity. Here we illustrate its use with some pilot data from a group of manifest HD patients and age-matched controls. Even in this small cohort, differences in the responses are apparent that appear to relate to the severity of the disease as measured by conventional behavioural tests

    Neonatal resuscitation and immediate newborn assessment and stimulation for the prevention of neonatal deaths: a systematic review, meta-analysis and Delphi estimation of mortality effect

    Get PDF
    BACKGROUND: Of 136 million babies born annually, around 10 million require assistance to breathe. Each year 814,000 neonatal deaths result from intrapartum-related events in term babies (previously "birth asphyxia") and 1.03 million from complications of prematurity. No systematic assessment of mortality reduction from tactile stimulation or resuscitation has been published. OBJECTIVE: To estimate the mortality effect of immediate newborn assessment and stimulation, and basic resuscitation on neonatal deaths due to term intrapartum-related events or preterm birth, for facility and home births. METHODS: We conducted systematic reviews for studies reporting relevant mortality or morbidity outcomes. Evidence was assessed using GRADE criteria adapted to provide a systematic approach to mortality effect estimates for the Lives Saved Tool (LiST). Meta-analysis was performed if appropriate. For interventions with low quality evidence but strong recommendation for implementation, a Delphi panel was convened to estimate effect size. RESULTS: We identified 24 studies of neonatal resuscitation reporting mortality outcomes (20 observational, 2 quasi-experimental, 2 cluster randomized controlled trials), but none of immediate newborn assessment and stimulation alone. A meta-analysis of three facility-based studies examined the effect of resuscitation training on intrapartum-related neonatal deaths (RR= 0.70, 95%CI 0.59-0.84); this estimate was used for the effect of facility-based basic neonatal resuscitation (additional to stimulation). The evidence for preterm mortality effect was low quality and thus expert opinion was sought. In community-based studies, resuscitation training was part of packages with multiple concurrent interventions, and/or studies did not distinguish term intrapartum-related from preterm deaths, hence no meta-analysis was conducted. Our Delphi panel of 18 experts estimated that immediate newborn assessment and stimulation would reduce both intrapartum-related and preterm deaths by 10%, facility-based resuscitation would prevent a further 10% of preterm deaths, and community-based resuscitation would prevent further 20% of intrapartum-related and 5% of preterm deaths. CONCLUSION: Neonatal resuscitation training in facilities reduces term intrapartum-related deaths by 30%. Yet, coverage of this intervention remains low in countries where most neonatal deaths occur and is a missed opportunity to save lives. Expert opinion supports smaller effects of neonatal resuscitation on preterm mortality in facilities and of basic resuscitation and newborn assessment and stimulation at community level. Further evaluation is required for impact, cost and implementation strategies in various contexts. FUNDING: This work was supported by the Bill & Melinda Gates Foundation through a grant to the US Fund for UNICEF, and to the Saving Newborn Lives program of Save the Children, through Save the Children US

    Biomarker panel predicts survival after resection in pancreatic ductal adenocarcinoma: a multi-institutional cohort study.

    Get PDF
    Background: Up to 60% of patients who undergo curative-intent pancreatic ductal adenocarcinoma (PDAC) resection experience disease recurrence within six months. We recently published a systematic review of prognostic immunohistochemical biomarkers in PDAC and shortlisted a panel of those reported with the highest level of evidence, including p53, p16, Ca-125, S100A4, FOXC1, EGFR, mesothelin, CD24 and UPAR. This study aims to discover and validate the prognostic significance of a combinatorial panel of tumor biomarkers in patients with resected PDAC. Methods: Patients who underwent PDAC resection were included from a single institution discovery cohort and a multi-institutional validation cohort. Tumors in the discovery cohort were stained immunohistochemically for all nine shortlisted biomarkers. Biomarkers significantly associated with overall survival (OS) were reevaluated as a combinatorial panel in both discovery and validation cohorts for its prognostic significance. Results: 224 and 191 patients were included in the discovery and validation cohorts, respectively. In both cohorts, S100A4, Ca-125 and mesothelin expression were associated with shorter OS. In both cohorts, the number of these biomarkers expressed was significantly associated with OS (discovery cohort 36.8 vs. 26.4 vs 16.3 vs 12.8 months, P < 0.001; validation cohort 25.2 vs 18.3 vs 13.6 vs 11.9 months, P = 0.008 for expression of zero, one, two and three biomarkers, respectively). On multivariable analysis, expression of at least one of three biomarkers was independently associated with shorter OS. Conclusion: Combinations of S100A4, Ca-125 and mesothelin expression stratify survival after resection of localized PDAC. Co-expression of all three biomarkers is associated with the poorest prognostic outcome
    • …
    corecore