95 research outputs found

    Line-start permanent-magnet motor single-phase steady-state performance analysis

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    This paper describes an efficient calculating procedure for the steady-state operation of a single-phase line-start capacitor-run permanent-magnet motor. This class of motor is beginning to be applied in hermetic refrigerator compressors as a high-efficiency alternative to either a plain induction motor or a full inverter-fed drive. The calculation relies on a combination of reference-frame transformations including symmetrical components to cope with imbalance, and dq axes to cope with saliency. Computed results are compared with test data. The agreement is generally good, especially in describing the general properties of the motor. However, it is shown that certain important effects are beyond the limit of simple circuit analysis and require a more complex numerical analysis method

    Recent Developments in the Use of Flow Hydrogenation in the Field of Medicinal Chemistry

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    This chapter focuses on recent applications of flow hydrogenation in medicinal chemistry. Flow reactors can enhance laboratory safety, reducing the risks associated with pyrophoric catalysts, due to their containment in catalyst cartridges or omnifit columns. Flow hydrogenation reduces the risks arising from hydrogen gas, with either hydrogen generated in situ from water, or precise management of the gas flow rate through tube-in-tube reactors. There is an increasing body of evidence that flow hydrogenation enhances reduction outcomes across nitro, imine, nitrile, amide, azide, and azo reductions, together with de-aromatisation and hydrodehalogenation. In addition, olefin, alkyne, carbonyl, and benzyl reductions have been widely examined. Further, protocols involving multistage flow reactions involving hydrogenation are highlighted

    Reversible Dual-Covalent Molecular Locking of the 14-3-3/ERRÎł Protein-Protein Interaction as a Molecular Glue Drug Discovery Approach

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    Molecules that stabilize protein-protein interactions (PPIs) are invaluable as tool compounds for biophysics and (structural) biology, and as starting points for molecular glue drug discovery. However, identifying initial starting points for PPI stabilizing matter is highly challenging, and chemical optimization is labor-intensive. Inspired by chemical crosslinking and reversible covalent fragment-based drug discovery, we developed an approach that we term “molecular locks” to rapidly access molecular glue-like tool compounds. These dual-covalent small molecules reversibly react with a nucleophilic amino acid on each of the partner proteins to dynamically crosslink the protein complex. The PPI between the hub protein 14-3-3 and estrogen-related receptor γ (ERRγ) was used as a pharmacologically relevant case study. Based on a focused library of dual-reactive small molecules, a molecular glue tool compound was rapidly developed. Biochemical assays and X-ray crystallographic studies validated the ternary covalent complex formation and overall PPI stabilization via dynamic covalent crosslinking. The molecular lock approach is highly selective for the specific 14-3-3/ERRγ complex, over other 14-3-3 complexes. This selectivity is driven by the interplay of molecular reactivity and molecular recognition of the composite PPI binding interface. The long lifetime of the dual-covalent locks enabled the selective stabilization of the 14-3-3/ERRγ complex even in the presence of several other competing 14-3-3 clients with higher intrinsic binding affinities. The molecular lock approach enables systematic, selective, and potent stabilization of protein complexes to support molecular glue drug discovery.</p

    Health risks encountered by Dutch medical students during an elective in the tropics and the quality and comprehensiveness of pre-and post-travel care

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    <p>Abstract</p> <p>Background</p> <p>Clinical and research electives abroad offer medical students many unique experiences. However, participating in an unfamiliar health-care setting combined with limited medical experience may place students at risk of illness. To improve pre-and post-travel care, we assessed the health risks and the quality and comprehensiveness of pre-and post-travel care in a cohort of Dutch medical students returning form an elective abroad.</p> <p>Methods</p> <p>All medical students who had performed an elective in the tropics between July 2006 and December 2008 were sent an informative email asking them to complete a web-based questionnaire.</p> <p>Results</p> <p>180 of 242 (74%) students completed the questionnaire. Regarding the risk of bloodborne viral infection: 67% of all students and 32% of junior students engaged in procedures that constitute a risk of exposure to bloodborne viral infection, often in countries with high HIV prevalence rates. None of nine students who experienced possible or certain mucosal or percutaneous exposure to potentially infectious body fluids reported the exposure at the time it occurred and none used PEP. Regarding other health risks: 8 of 40 (20%) students stopped using mefloquine due to adverse effects. This left a sizeable proportion unprotected in countries that are hyperendemic for malaria. Post-travel screening for schistosomiasis, tuberculosis (tuberculin skin test) and carriage of methicillin-resistant Staphylococcus aureus (MRSA) encompassed approximately half of all students who should have been screened.</p> <p>Conclusions</p> <p>Based on the results of this study we have adopted an integral set of measures to reduce the health risks associated with an elective abroad. The pre and post-travel consult has been centralized and standardized as well as the distribution of PEP. In addition we have developed a mandatory module on Global Health for all medical students planning an elective abroad.</p

    Rape, inequality and the criminal justice response in England: The importance of age and gender

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    © The Author(s) 2019. This article draws upon quantitative and content analysis of 585 reports of rape recorded within two police force areas in England in 2010 and in 2014 tracking individual incidents to eventual outcome to examine the impact, if any, of intersecting inequalities on trajectories of rape cases reported to police. The data were collected as part of the wider Economic and Social Research Council funded Justice, Inequality and Gender-Based Violence research project which examined victim-survivor experiences and perspectives on justice. Building on existing distinctions between types of rape case based on the relationship between victim-survivor and accused, the results suggest age and gender are significant factors in how sexual violence, and the criminal justice system, is experienced. While younger women and girls were disproportionately affected by certain types of sexual violence case and more likely to come into contact with the criminal justice system compared to men and older women, they were not necessarily more likely to achieve a conviction. The findings also confirm that some of the most vulnerable victims-survivors of sexual violence, especially those with poor mental health, are still not achieving criminal justice. Victims-survivors from Black and minority ethnic group or lesbian, gay, bisexual, transgender, transsexual, queer groups are underrepresented within the criminal justice system, implying these groups are not seeking a criminal justice response in the same way as ‘white’ heterosexual victims-survivors

    ‘I actually know that things will get better’:The many pathways to resilience of LGBTQIA+ youth in out-of-home care

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    Research on the lives of lesbian, gay, bisexual, transgender, queer, intersex, asexual and other forms of sexual identities and orientations (LGBTQIA+) youth in care has mainly examined their experiences from a risk-based approach, while few studies have explored their resilience experiences. Using in-depth interviews, the present study aims to illuminate the resilience experiences of 13 LGBTQIA+ young people in out-of-home care in the Netherlands. Four themes emerged from their narratives: relationships that support and empower; construction of a positive identity around their sexual orientation and gender identity and expression (SOGIE); community involvement and self-relying strategies. Our findings support the view of resilience as a complex process that shows at an individual, interpersonal and social level

    Travel risk behaviours and uptake of pre-travel health preventions by university students in Australia

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    <p>Abstract</p> <p>Background</p> <p>Forward planning and preventative measures before travelling can significantly reduce the risk of many vaccine preventable travel-related infectious diseases. Higher education students may be at an increased risk of importing infectious disease as many undertake multiple visits to regions with higher infectious disease endemicity. Little is known about the health behaviours of domestic or international university students, particularly students from low resource countries who travel to high-resource countries for education. This study aimed to assess travel-associated health risks and preventative behaviours in a sample of both domestic and international university students in Australia.</p> <p>Methods</p> <p>In 2010, a 28 item self-administered online survey was distributed to students enrolled at the University of New South Wales, Sydney, Australia. Multiple methods of distributing links to the online survey were utilised. The survey examined the international travel history, travel intentions, infection control behaviours and self-reported vaccination history.</p> <p>Results</p> <p>A total of 1663 respondents completed the online survey, 22.1% were international students and 83.9% were enrolled at an undergraduate level. Half had travelled internationally in the previous 12 months, with 69% of those travelling only once during that time with no difference in travel from Australia between domestic and international students (<it>p </it>= 0.8). Uptake of pre-travel health advice was low overall with 68% of respondents reporting they had not sought any advice from a health professional prior to their last international trip. Domestic students were more likely to report uptake of a range of preventative travel health measures compared to international students, including diarrhoeal medication, insect repellent, food avoidance and condoms (<it>P </it>< 0.0001). Overall, students reported low risk perception of travel threats and a low corresponding concern for these threats.</p> <p>Conclusions</p> <p>Our study highlights the need to educate students about the risk associated with travel and improve preventative health-seeking and uptake of precautionary health measures in this highly mobile young adult population. Although immunisation is not an entry requirement to study at Universities in Australia, large tertiary institutions provide an opportunity to engage with young adults on the importance of travel health and provision of vaccines required for travel, including missed childhood vaccines.</p

    Re-evaluating the measurement and influence of conscious movement processing on gait performance in older adults: development of the Gait-Specific Attentional Profile

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    Background. Recent decades have seen increased interest in how anxiety–and associated changes in conscious movement processing (CMP)–can influence the control of balance and gait, particularly in older adults. However, the most prevalent scale used to measure CMP during gait (the Movement-Specific Reinvestment Scale (MSRS)) is generic (i.e., non-gait specific) and potentially lacks sensitivity in this context. Methods. In a preliminary study, we first sought to evaluate if MSRS scores associated with the number of CMP-related thoughts self-reported by older adults while walking. The next aim was to develop and validate a new questionnaire (the Gait-Specific Attentional Profile, G-SAP) capable of measuring gait-specific CMP, in addition to other attentional processes purported to influence gait. This scale was validated using responses from 117 (exploratory) and 107 (confirmatory factor analysis) older adults, resulting in an 11-item scale with four sub-scales: CMP, anxiety, fall-related ruminations, and processing inefficiencies. Finally, in a separate cohort of 53 older adults, we evaluated associations between scores from both the GSAP CMP subscale and the MSRS, and gait outcomes measured using a GAITRite walkway in addition to participants’ fall-history. Results. MSRS scores were not associated with self-reported thoughts categorised as representing CMP. In regression analyses that controlled for functional balance, unlike the MSRS, the G-SAP subscale of CMP significantly predicted several gait characteristics including velocity (p=.033), step length (p=.032), and double-limb support (p=.015). Significance. The G-SAP provides gait-specific measures of four psychological factors implicated in mediating the control of balance and gait. In particular, unlike the MSRS, the G-SAP subscale of CMP appears sensitive to relevant attentional processes known to influence gait performance. We suggest that the G-SAP offers an opportunity for the research community to further develop understanding of psychological factors impacting gait performance across a range of applied clinical contexts
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