703 research outputs found

    New Symmetries in Crystals and Handed Structures

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    For over a century, the structure of materials has been described by a combination of rotations, rotation-inversions and translational symmetries. By recognizing the reversal of static structural rotations between clockwise and counterclockwise directions as a distinct symmetry operation, here we show that there are many more structural symmetries than are currently recognized in right- or left-handed handed helices, spirals, and in antidistorted structures composed equally of rotations of both handedness. For example, though a helix or spiral cannot possess conventional mirror or inversion symmetries, they can possess them in combination with the rotation reversal symmetry. Similarly, we show that many antidistorted perovskites possess twice the number of symmetry elements as conventionally identified. These new symmetries predict new forms for "roto" properties that relate to static rotations, such as rotoelectricity, piezorotation, and rotomagnetism. They also enable symmetry-based search for new phenomena, such as multiferroicity involving a coupling of spins, electric polarization and static rotations. This work is relevant to structure-property relationships in all material structures with static rotations such as minerals, polymers, proteins, and engineered structures.Comment: 15 Pages, 4 figures, 3 Tables; Fig. 2b has error

    The use of thermographic imaging to evaluate therapeutic response in human tumour xenograft models

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    YesNon-invasive methods to monitor tumour growth are an important goal in cancer drug development. Thermographic imaging systems offer potential in this area, since a change in temperature is known to be induced due to changes within the tumour microenvironment. This study demonstrates that this imaging modality can be applied to a broad range of tumour xenografts and also, for the first time, the methodology’s suitability to assess anti-cancer agent efficacy. Mice bearing subcutaneously implanted H460 lung cancer xenografts were treated with a novel vascular disrupting agent, ICT-2552, and the cytotoxin doxorubicin. The effects on tumour temperature were assessed using thermographic imaging over the first 6 hours post-administration and subsequently a further 7 days. For ICT-2552 a significant initial temperature drop was observed, whilst for both agents a significant temperature drop was seen compared to controls over the longer time period. Thus thermographic imaging can detect functional differences (manifesting as temperature reductions) in the tumour response to these anti-cancer agents compared to controls. Importantly, these effects can be detected in the first few hours following treatment and therefore the tumour is observable non-invasively. As discussed, this technique will have considerable 3Rs benefits in terms of reduction and refinement of animal use.University of Bradfor

    Long-term burden of increased body mass index from childhood on adult dyslipidemia: the i3C Consortium study

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    Background: Data are limited regarding the association of cumulative burden and trajectory of body mass index (BMI) from early life with adult lipid disorders. Methods: The study cohort consisted of 5195 adults who had BMI repeatedly measured 4 to 21 times from childhood and had blood lipid measurements of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) and information on lipid-lowering medications in the last adult survey. The area under the curve (AUC) was calculated as a measure of long-term burden (total AUC) and trends (incremental AUC) of BMI. Results: Participants with dyslipidemia, high LDL-C, low HDL-C and high TG had consistently and significantly higher BMI levels from childhood to adulthood compared to those with normal lipid levels. After adjusting for age, race, sex, and cohort, increased risk of adult dyslipidemia was significantly associated with higher values of childhood BMI, adulthood BMI, total AUC and incremental AUC, with odds ratio (95% confidence interval) = 1.22 (1.15-1.29), 1.85 (1.74-1.97), 1.61 (1.52-1.71), and 1.59 (1.50-1.69), respectively, and p Conclusions: Adults with dyslipidemia versus normal lipid levels have consistently higher levels and distinct life-course trajectories of BMI, suggesting that the impact of excessive body weight on dyslipidemia originates in early life

    Childhood/adolescent smoking and adult smoking and cessation: The International Childhood Cardiovascular Cohort (i3C) Consortium

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    Background: Despite declining US adolescent smoking prevalence from 40% among 12th graders in 1995 to around 10% in 2018, adolescent smoking is still a significant problem. Using the International Childhood Cardiovascular Cohort (i3C) Consortium, which includes 7 international cohorts recruited in childhood and followed into adulthood, the present study was designed to confirm the important relation between adolescent smoking and daily adult smoking and present new data on adult smoking into the forties and comparison of smoking in the United States, Finland, and Australia. Methods and Results: Childhood smoking experience during ages 6 to 19 in the 1970s and 1980s was classifiable in 6687 i3C participants who also provided smoking status in their twenties and forties through 2011-2018. Prevalence of daily smoking in their twenties was directly related to degree of smoking during adolescence and inversely related to the age at which that smoking experience occurred (P trend, P trend, Conclusions: These long-term follow-up data show that smoking intensity increased throughout adolescence. Prevalence of adult smoking and cessation by the forties were both correlated with levels of childhood smoking intensity. These data lend support to preventive strategies designed to reduce, delay, or eliminate any youth access to cigarettes

    Are old running shoes detrimental to your feet? A pedobarographic study

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    <p>Abstract</p> <p>Background</p> <p>Footwear characteristics have been implicated in fatigue and foot pain. The recommended time for changing running shoes is every 500 miles. The aim of our study was to assess and compare plantar peak pressures and pressure time integrals in new and old running shoes.</p> <p>Findings</p> <p>This was a prospective study involving 11 healthy female volunteers with no previous foot and ankle problems. New running shoes were provided to the participants. Plantar pressures were measured using the Novel Pedar system while walking with new and participants' personal old running shoes. Plantar pressures were measured in nine areas of the feet. Demographic data, age of old running shoes, Body Mass Index (BMI), peak pressures and pressure-time integral were acquired. The right and left feet were selected at random and assessed separately. Statistical analysis was done using the paired t test to compare measurements between old and new running shoes.</p> <p>The mean peak pressures were higher in new running shoes (330.5 ± 79.6 kiloPascals kPa) when compared to used old running shoes (304 ± 58.1 kPa) (p = 0.01). The pressure-time integral was significantly higher in the new running shoes (110 ± 28.3 kPa s) compared to used old running shoes (100.7 ± 24.0 kPa s) (p = 0.01).</p> <p>Conclusion</p> <p>Plantar pressure measurements in general were higher in new running shoes. This could be due to the lack of flexibility in new running shoes. The risk of injury to the foot and ankle would appear to be higher if running shoes are changed frequently. We recommend breaking into new running shoes slowly using them for mild physical activity.</p

    Why is it difficult to implement e-health initiatives? A qualitative study

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    &lt;b&gt;Background&lt;/b&gt; The use of information and communication technologies in healthcare is seen as essential for high quality and cost-effective healthcare. However, implementation of e-health initiatives has often been problematic, with many failing to demonstrate predicted benefits. This study aimed to explore and understand the experiences of implementers - the senior managers and other staff charged with implementing e-health initiatives and their assessment of factors which promote or inhibit the successful implementation, embedding, and integration of e-health initiatives.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods&lt;/b&gt; We used a case study methodology, using semi-structured interviews with implementers for data collection. Case studies were selected to provide a range of healthcare contexts (primary, secondary, community care), e-health initiatives, and degrees of normalization. The initiatives studied were Picture Archiving and Communication System (PACS) in secondary care, a Community Nurse Information System (CNIS) in community care, and Choose and Book (C&#38;B) across the primary-secondary care interface. Implementers were selected to provide a range of seniority, including chief executive officers, middle managers, and staff with 'on the ground' experience. Interview data were analyzed using a framework derived from Normalization Process Theory (NPT).&lt;p&gt;&lt;/p&gt; &lt;b&gt;Results&lt;/b&gt; Twenty-three interviews were completed across the three case studies. There were wide differences in experiences of implementation and embedding across these case studies; these differences were well explained by collective action components of NPT. New technology was most likely to 'normalize' where implementers perceived that it had a positive impact on interactions between professionals and patients and between different professional groups, and fit well with the organisational goals and skill sets of existing staff. However, where implementers perceived problems in one or more of these areas, they also perceived a lower level of normalization.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions&lt;/b&gt; Implementers had rich understandings of barriers and facilitators to successful implementation of e-health initiatives, and their views should continue to be sought in future research. NPT can be used to explain observed variations in implementation processes, and may be useful in drawing planners' attention to potential problems with a view to addressing them during implementation planning

    A cross sectional evaluation of an alcohol intervention targeting young university students

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    BACKGROUND: Hazardous drinking has been found to be higher among young university students compared to their non-university peers. Although young university students are exposed to new and exciting experiences, including greater availability and emphasis on social functions involving alcohol there are few multi strategy comprehensive interventions aimed at reducing alcohol-related harms. METHODS: Random cross sectional online surveys were administered to 18-24 year old students studying at the main campus of a large metropolitan university in Perth, Western Australia. Prior to the completion of the second survey an alcohol intervention was implemented on campus. Completed surveys were received from 2465 (Baseline; T1) and 2422 (Post Year 1: T2) students. Students who consumed alcohol in the past 12 months were categorised as low risk or hazardous drinkers using the Alcohol Use Disorders Identification Test (AUDIT). Due to the cross sectional nature of the two samples two-tailed two-proportion z-test and two sample t-tests were employed to determine statistical significance between the two time periods for categorical and continuous variables respectively. RESULTS: At T1 and T2 89.1 % and 87.2 % of the total sample reported drinking alcohol in the past month respectively. Hazardous levels of alcohol consumption reduced slightly between T1 (39.7 %) and T2 (38 %). In both time periods hazardous drinkers reported significantly higher mean scores for experienced harm, second-hand harm and witnessed harm scores compared to low risk drinkers (p &lt;0.001). Hazardous drinkers were significantly more likely to experience academic problems due to their alcohol consumption and to report more positive alcohol expectations than low risk drinkers at both time periods (p &lt;0.001). CONCLUSIONS: Harms and problems for students who report hazardous drinking are of concern and efforts should be made to ensure integrated and targeted strategies reach higher risk students and focus on specific issues such as driving while intoxicated and alcohol related unplanned sexual activity. However there is also a need for universal strategies targeting all students and low risk drinkers as they too are exposed to alcohol harms within the drinking and social environment. Changing the culture of the university environment is a long term aim and to effect change a sustained combination of organisational actions, partnerships and educational actions is required

    Understanding clinician attitudes towards implementation of guided self-help cognitive behaviour therapy for those who hear distressing voices: using factor analysis to test normalisation process theory

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    Background The Normalisation Process Theory (NPT) has been used to understand the implementation of physical health care interventions. The current study aims to apply the NPT model to a secondary mental health context, and test the model using exploratory factor analysis. This study will consider the implementation of a brief cognitive behaviour therapy for psychosis (CBTp) intervention. Methods Mental health clinicians were asked to complete a NPT-based questionnaire on the implementation of a brief CBTp intervention. All clinicians had experience of either working with the target client group or were able to deliver psychological therapies. In total, 201 clinicians completed the questionnaire. Results The results of the exploratory factor analysis found partial support for the NPT model, as three of the NPT factors were extracted: (1) coherence, (2) cognitive participation, and (3) reflexive monitoring. We did not find support for the fourth NPT factor (collective action). All scales showed strong internal consistency. Secondary analysis of these factors showed clinicians to generally support the implementation of the brief CBTp intervention. Conclusions This study provides strong evidence for the validity of the three NPT factors extracted. Further research is needed to determine whether participants’ level of seniority moderates factor extraction, whether this factor structure can be generalised to other healthcare settings, and whether pre-implementation attitudes predict actual implementation outcomes

    An exploratory randomised controlled trial of a premises-level intervention to reduce alcohol-related harm including violence in the United Kingdom

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    &lt;b&gt;Background&lt;/b&gt;&lt;p&gt;&lt;/p&gt; To assess the feasibility of a randomised controlled trial of a licensed premises intervention to reduce severe intoxication and disorder; to establish effect sizes and identify appropriate approaches to the development and maintenance of a rigorous research design and intervention implementation.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods&lt;/b&gt;&lt;p&gt;&lt;/p&gt; An exploratory two-armed parallel randomised controlled trial with a nested process evaluation. An audit of risk factors and a tailored action plan for high risk premises, with three month follow up audit and feedback. Thirty-two premises that had experienced at least one assault in the year prior to the intervention were recruited, match paired and randomly allocated to control or intervention group. Police violence data and data from a street survey of study premises’ customers, including measures of breath alcohol concentration and surveyor rated customer intoxication, were used to assess effect sizes for a future definitive trial. A nested process evaluation explored implementation barriers and the fidelity of the intervention with key stakeholders and senior staff in intervention premises using semi-structured interviews.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Results&lt;/b&gt;&lt;p&gt;&lt;/p&gt; The process evaluation indicated implementation barriers and low fidelity, with a reluctance to implement the intervention and to submit to a formal risk audit. Power calculations suggest the intervention effect on violence and subjective intoxication would be raised to significance with a study size of 517 premises.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions&lt;/b&gt;&lt;p&gt;&lt;/p&gt; It is methodologically feasible to conduct randomised controlled trials where licensed premises are the unit of allocation. However, lack of enthusiasm in senior premises staff indicates the need for intervention enforcement, rather than voluntary agreements, and on-going strategies to promote sustainability
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