1,115 research outputs found

    Factors affecting the f× Q product of 3C-SiC microstrings: What is the upper limit for sensitivity?

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    © 2016 AIP Publishing LLC. The fn×Q (Hz) is a crucial sensitivity parameter for micro-electro-mechanical sensing. We have recently shown a fn×Q product of ∼1012Hz for microstrings made of cubic silicon carbide on silicon, establishing a new state-of-the-art and opening new frontiers for mass sensing applications. In this work, we analyse the main parameters influencing the frequency and quality factor of silicon carbide microstrings (material properties, microstring geometry, clamping condition, and environmental pressure) and investigate the potential for approaching the theoretical upper limit. We indicate that our previous result is only about a factor 2 lower than the thermoelastic dissipation limit. For fully reaching this upper limit, a substantial reduction of the defects in the silicon carbide thin film would be required, while maintaining a high residual tensile stress in the perfect-clamped strings

    The impact of hyperhidrosis on patients' daily life and quality of life : A qualitative investigation

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    Background: An understanding of the daily life impacts of hyperhidrosis and how patients deal with them, based on qualitative research, is lacking. This study investigated the impact of hyperhidrosis on the daily life of patients using a mix of qualitative research methods. Methods: Participants were recruited through hyperhidrosis patient support groups such as the Hyperhidrosis Support Group UK. Data were collected using focus groups, interviews and online surveys. A grounded theory approach was used in the analysis of data transcripts. Data were collected from 71 participants, out of an initial 100 individuals recruited. Results: Seventeen major themes capturing the impacts of hyperhidrosis were identified; these covered all areas of life including daily life, psychological well-being, social life, professional /school life, dealing with hyperhidrosis, unmet health care needs and physical impact. Conclusions: Psychosocial impacts are central to the overall impacts of hyperhidrosis, cutting across and underlying the limitations experienced in other areas of life.Peer reviewe

    Poro-mechanical analysis of a biomimetic scaffold for osteochondral defects

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    Osteochondral defects are focal areas of damage involving articular cartilage and sub-chondral bone. Tissue engineering scaffolds are used to improve the organism regeneration ability for this kind of injury, serving as biocompatible structures for cell viability and differentiation. Since biomechanical cues such as substrate stiffness, loading conditions and fluid permeation are fundamental for successful tissue repair, understanding how these features vary in the scaffold is of primary importance. Here we present a mathematical model based on porous media mechanics for the analysis of a tissue engineering scaffold. We consider a three-layered scaffold mimicking a complete osteochondral tissue and vary the mechanical properties of the intermediate layer over a physiological range. Our results show that the interstitial fluid pressure and the vertical component of the solid effective stress depend significantly on the stiffness and permeability of the intermediate layer under mechanical loading. By properly tuning these material properties, regimes of slow or fast temporal variations of mechanical stress can be obtained in the scaffold layer of interest

    Applying human factors methods to explore ‘Work as Imagined’ and ‘Work as Done’ in the Emergency Department’s response to chemical, biological, radiological, and nuclear events

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    The Emergency Department (ED) is a complex, hectic, and high-pressured environment. Chemical, Biological, Radiological, and Nuclear (CBRN) events are multi-faceted emergencies and present numerous challenges to ED staff (first receivers) with large scale trauma, consequently requiring a combination of complex responses. Human Factors and Ergonomics (HF/E) methods such as Hierarchical Task Analysis (HTA) have been used in healthcare research. However, HF/E methods and theory have not been combined to understand how the ED responds to CBRN events. This study aimed to compare Work as Imagined (WAI) and Work as Done (WAD) in the ED CBRN response in a UK based hospital. WAI was established by carrying out document analyses on a CBRN plan and WAD by exploring first receivers response to CBRN scenario cards. The responses were converted to HTAs and compared. The WAI HTAs showed 4-8 phases of general organizational responsibilities during a CBRN event. WAD HTAs placed emphasis on diagnosing and treating presenting conditions. A comparison of WAI and WAD HTAs highlighted common actions and tasks. This study has identified three key differences between WAI and WAD in the ED CBRN response: 1) documentation of the CBRN event 2) treating the patient and 3) diagnosing the presenting complaint. Findings from this study provide an evidence base which can be used to inform future clinical policy and practice in providing safe and high quality care during CBRN events in the ED

    Conformational Flexibility of Hybrid [3]- and [4]-Rotaxanes

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    The synthesis, structures, and properties of [4]- and [3]-rotaxane complexes are reported where [2]-rotaxanes, formed from heterometallic {Cr7Ni} rings, are bound to a fluoride-centered {CrNi2} triangle. The compounds have been characterized by single-crystal X-ray diffraction and have the formulas [CrNi2(F)(O2CtBu)6]{(BH)[Cr7NiF8(O2CtBu)16]}3 (3) and [CrNi2(F)(O2CtBu)6(THF)]{(BH)[Cr7NiF8(O2CtBu)16]}2 (4), where B = py-CH2CH2NHCH2C6H4SCH3. The [4]-rotaxane 3 is an isosceles triangle of three [2]-rotaxanes bound to the central triangle while the [3]-rotaxane 4 contains only two [2]-rotaxanes bound to the central triangle. Studies of the behavior of 3 and 4 in solution by small-angle X-ray scattering and atomistic molecular dynamic simulations show that the structure of 3 is similar to that found in the crystal but that 4 has a different conformation to the crystal. Continuous wave and pulsed electron paramagnetic resonance spectroscopy was used to study the structures present and demonstrate that in frozen solutions (at 5 K) 4 forms more extended molecules than 3 and with a wider range of conformations

    Design and feasibility testing of a novel group intervention for young women who binge drink in groups

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    BackgroundYoung women frequently drink alcohol in groups and binge drinking within these natural drinking groups is common. This study describes the design of a theoretically and empirically based group intervention to reduce binge drinking among young women. It also evaluates their engagement with the intervention and the acceptability of the study methods.MethodsFriendship groups of women aged 18–35 years, who had two or more episodes of binge drinking (>6 UK units on one occasion; 48g of alcohol) in the previous 30 days, were recruited from the community. A face-to-face group intervention, based on the Health Action Process Approach, was delivered over three sessions. Components of the intervention were woven around fun activities, such as making alcohol free cocktails. Women were followed up four months after the intervention was delivered. Results The target of 24 groups (comprising 97 women) was recruited. The common pattern of drinking was infrequent, heavy drinking (mean consumption on the heaviest drinking day was UK 18.1 units). Process evaluation revealed that the intervention was delivered with high fidelity and acceptability of the study methods was high. The women engaged positively with intervention components and made group decisions about cutting down. Twenty two groups set goals to reduce their drinking, and these were translated into action plans. Retention of individuals at follow up was 87%.ConclusionsThis study successfully recruited groups of young women whose patterns of drinking place them at high risk of acute harm. This novel approach to delivering an alcohol intervention has potential to reduce binge drinking among young women. The high levels of engagement with key steps in the behavior change process suggests that the group intervention should be tested in a full randomised controlled trial

    A pilot Internet "Value of Health" Panel: recruitment, participation and compliance

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    Objectives To pilot using a panel of members of the public to provide preference data via the Internet Methods A stratified random sample of members of the general public was recruited and familiarised with the standard gamble procedure using an Internet based tool. Health states were perdiodically presented in "sets" corresponding to different conditions, during the study. The following were described: Recruitment (proportion of people approached who were trained); Participation (a) the proportion of people trained who provided any preferences and (b) the proportion of panel members who contributed to each "set" of values; and Compliance (the proportion, per participant, of preference tasks which were completed). The influence of covariates on these outcomes was investigated using univariate and multivariate analyses. Results A panel of 112 people was recruited. 23% of those approached (n = 5,320) responded to the invitation, and 24% of respondents (n = 1,215) were willing to participate (net = 5.5%). However, eventual recruitment rates, following training, were low (2.1% of those approached). Recruitment from areas of high socioeconomic deprivation and among ethnic minority communities was low. Eighteen sets of health state descriptions were considered over 14 months. 74% of panel members carried out at least one valuation task. People from areas of higher socioeconomic deprivation and unmarried people were less likely to participate. An average of 41% of panel members expressed preferences on each set of descriptions. Compliance ranged from 3% to 100%. Conclusion It is feasible to establish a panel of members of the general public to express preferences on a wide range of health state descriptions using the Internet, although differential recruitment and attrition are important challenges. Particular attention to recruitment and retention in areas of high socioeconomic deprivation and among ethnic minority communities is necessary. Nevertheless, the panel approach to preference measurement using the Internet offers the potential to provide specific utility data in a responsive manner for use in economic evaluations and to address some of the outstanding methodological uncertainties in this field

    Exploring the current and future role of the pharmacists in osteoporosis screening and management in Malaysia

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    Background Several studies have found that pharmacists can assist in screening and prevention of osteoporosis by referring patients for bone mineral density scans and counselling on lifestyle changes. In Malaysia, screening osteoporosis in all elderly women is not mandatory due to its cost. One approach to address this gap is to develop a pharmacist-led osteoporosis screening and prevention program. However, there is a paucity of data on the perspectives of Malaysian pharmacists in this area. Objective To explore the perspective of stakeholders (policy makers, doctors, pharmacists, nurses and patients) towards the role of pharmacists in osteoporosis screening and management. Setting A primary care clinic located within a teaching hospital in Kuala Lumpur, Malaysia. Method Patients (n = 20), nurses (n = 10), pharmacists (n = 11), doctors (n = 10) and policy makers (n = 5) were individually interviewed using a semi-structured topic guide. Purposive sampling was used. Interviews were transcribed verbatim and analysed using thematic analysis. Main outcome measure Perspective of stakeholders on the current and future role of pharmacists. Results All participants perceived pharmacists to be suppliers of medication, although there was some recognition of roles in providing medication advice. Nonetheless, these stakeholders were eager for pharmacists to expand their non-dispensing roles towards counselling, creating awareness and screening of osteoporosis. Interviewed pharmacists referred to their current role as ‘robotic dispensers’ and unanimously agreed to spread out to osteoporosis management role. Conclusion Under stakeholders there is a willingness to expand the role of pharmacists in Malaysia to non-dispensing roles, particularly in osteoporosis screening and management

    ACE2 gene expression is up-regulated in the human failing heart

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    BACKGROUND: ACE2 is a novel homologue of angiotensin converting enzyme (ACE). ACE2 is highly expressed in human heart and animal data suggest that ACE2 is an essential regulator of cardiac function in vivo. Since overactivity of the renin-angiotensin system contributes to the progression of heart failure, this investigation assessed changes in gene expression of ACE2, ACE, AT(1 )receptor and renin in the human failing heart. METHODS: The sensitive technique of quantitative reverse transcriptase polymerase chain reaction was used to determine the level of mRNA expression of ACE and ACE2 in human ventricular myocardium from donors with non-diseased hearts (n = 9), idiopathic dilated cardiomyopathy (IDC, n = 11) and ischemic cardiomyopathy (ICM, n = 12). Following logarithmic transformation of the data, a one-way analysis of variance was performed for each target gene followed by a Dunnett's test to compare the two disease groups IDC and ICM versus control. RESULTS: As anticipated, ACE mRNA was found to be significantly increased in the failing heart with a 3.1 and 2.4-fold up-regulation found in IDC and ICM relative to non-diseased myocardium. Expression of ACE2 mRNA was also significantly up-regulated in IDC (2.4-fold increase) and ICM (1.8-fold increase) versus non-diseased myocardium. No change in angiotensin AT(1 )receptor mRNA expression was found in failing myocardium and renin mRNA was not detected. CONCLUSIONS: These data suggest that ACE2 is up-regulated in human IDC and ICM and are consistent with the hypothesis that differential regulation of this enzyme may have important functional consequences in heart failure. This strengthens the hypothesis that ACE2 may be a relevant target for the treatment of heart failure and will hopefully spur further studies to clarify the functional effects in human myocardium of ACE2 derived peptides
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