132 research outputs found

    Phase transformation-induced superconducting aluminium-silicon alloy rings

    Full text link
    The development of a materials platform that exhibits both superconducting and semiconducting properties is an important endeavour for a range of emerging quantum technologies. We investigate the formation of superconductivity in nanowires fabricated with silicon-on-insulator (SOI). Aluminium from deposited contact electrodes is found to interdiffuses with the Si nanowire structures to form an Al-Si alloy along the entire length of the predefined nanowire device over micron length scales at temperatures well below that of the Al-Si eutectic. The resultant transformed nanowire structures are layered in geometry with a continuous Al-Si alloy wire sitting on the buried oxide of the SOI and a residual Si cap sitting on top of the wire. The phase transformed material is conformal with any predefined device patterns and the resultant structures are exceptionally smooth-walled compared to similar nanowire devices formed by silicidation processes. The superconducting properties of a mesoscopic AlSi ring formed on a SOI platform are investigated. Low temperature magnetoresistance oscillations, quantized in units of the fluxoid, h/2e, are observed.Comment: 11 pages, 9 figure

    Kindlin-1 promotes pulmonary breast cancer metastasis

    Get PDF
    Abstract In breast cancer, increased expression of the cytoskeletal adaptor protein Kindlin-1 has been linked to increased risks of lung metastasis, but the functional basis is unknown. Here, we show that in a mouse model of polyomavirus middle T antigen–induced mammary tumorigenesis, loss of Kindlin-1 reduced early pulmonary arrest and later development of lung metastasis. This phenotype relied on the ability of Kindlin-1 to bind and activate β integrin heterodimers. Kindlin-1 loss reduced α4 integrin–mediated adhesion of mammary tumor cells to the adhesion molecule VCAM-1 on endothelial cells. Treating mice with an anti–VCAM-1 blocking antibody prevented early pulmonary arrest. Kindlin-1 loss also resulted in reduced secretion of several factors linked to metastatic spread, including the lung metastasis regulator tenascin-C, showing that Kindlin-1 regulated metastatic dissemination by an additional mechanism in the tumor microenvironment. Overall, our results show that Kindlin-1 contributes functionally to early pulmonary metastasis of breast cancer. Significance: These findings provide a mechanistic proof in mice that Kindin-1, an integrin-binding adaptor protein, is a critical mediator of early lung metastasis of breast cancer. Cancer Res; 78(6); 1484–96. ©2018 AACR.</jats:p

    Direct correlation between potentiometric and impedance biosensing of antibody-antigen interactions using an integrated system

    Get PDF
    A fully integrated system that combines extended gate field-effect transistor (EGFET)-based potentiometric biosensors and electrochemical impedance spectroscopy (EIS)-based biosensors has been demonstrated. This integrated configuration enables the sequential measurement of the same immunological binding event on the same sensing surface and consequently sheds light on the fundamental origins of sensing signals produced by FET and EIS biosensors, as well as the correlation between the two. Detection of both the bovine serum albumin (BSA)/anti-BSA model system in buffer solution and bovine parainfluenza antibodies in complex blood plasma samples was demonstrated using the integrated biosensors. Comparison of the EGFET and EIS sensor responses reveals similar dynamic ranges, while equivalent circuit modeling of the EIS response shows that the commonly reported total impedance change (DZtotal) is dominated by the change in charge transfer resistance (Rct) rather than surface capacitance (Csurface). Using electrochemical kinetics and the Butler-Volmer equation, we unveil that the surface potential and charge transfer resistance, measured by potentiometric and impedance biosensors, respectively, are, in fact, intrinsically linked. This observation suggests that there is no significant gain in using the FET/EIS integrated system and leads to the demonstration that low-cost EGFET biosensors are sufficient as a detection tool to resolve the charge information of biomolecules for practical sensing applications

    Demographic, socioeconomic, and health correlates of unmet need for mental health treatment in the United States, 2002–16: evidence from the national surveys on drug use and health

    Get PDF
    Abstract: Background: Unmet need for mental health services remains high in the United States and is disproportionately concentrated in some groups. The scale and nature of these disparities have not been fully elucidated and bear further scrutiny. As such, in this study, we examine the demographic, socioeconomic, and health correlates of unmet need for mental health treatment as well as the reasons for unmet need. Methods: We draw upon the National Survey for Drug Use and Health (NSDUH) from 2002 to 16 for adults aged 18 and over in the United States (n = 579,017). Using multivariable logistic regression, we simultaneously model the demographic, socioeconomic, and health correlates of unmet need for mental health treatment from 2002 to 16. We also analyse the reasons for unmet need expressed by these populations, reasons which include cost, perceived stigma, minimisation of symptoms, low perceived effectiveness of treatment, and structural barriers. Results: Major characteristics associated with increased odds of unmet need include past year substance abuse or dependence (other than hallucinogens and sedatives), fair, poor, or very poor health, being female, and an educational attainment of college or higher. With respect to reasons for unmet need, cost was most often cited, followed by perceived stigma, structural barriers, and minimisation. Characteristics associated with increased odds of indicating cost as a reason for unmet need include: being uninsured or aged 26–35. Minimisation and low perceived effectiveness are mentioned by high-income persons as reasons for unmet need. College-educated persons and women had higher odds of citing structural barriers as a reason for unmet need. Conclusions: The correlates and causes of unmet need highlight the intersectionality of individual health needs with implications on addressing inequities in mental health policy and practice

    Rapid Discovery and Structure-Activity Relationships of Pyrazolopyrimidines that Potently Suppress Breast Cancer Cell Growth via SRC Kinase Inhibition with Exceptional Selectivity over ABL Kinase

    Get PDF
    Novel pyrazolopyrimidines displaying high potency and selectivity toward SRC family kinases have been developed by combining ligand-based design and phenotypic screening in an iterative manner. Compounds were derived from the promiscuous kinase inhibitor PP1 to search for analogs that could potentially target a broad spectrum of kinases involved in cancer. Phenotypic screening against MCF7 mammary adenocarcinoma cells generated target-agnostic structure–activity relationships that biased subsequent designs toward breast cancer treatment rather than to a particular target. This strategy led to the discovery of two potent antiproliferative leads with phenotypically distinct anticancer mode of actions. Kinase profiling and further optimization resulted in eCF506, the first small molecule with subnanomolar IC<sub>50</sub> for SRC that requires 3 orders of magnitude greater concentration to inhibit ABL. eCF506 exhibits excellent water solubility, an optimal DMPK profile and oral bioavailability, halts SRC-associated neuromast migration in zebrafish embryos without inducing life-threatening heart defects, and inhibits SRC phosphorylation in tumor xenografts in mice

    Nurse prescribing of medicines in Western European and Anglo-Saxon countries: a systematic review of the literature

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>A growing number of countries are introducing some form of nurse prescribing. However, international reviews concerning nurse prescribing are scarce and lack a systematic and theoretical approach. The aim of this review was twofold: firstly, to gain insight into the scientific and professional literature describing the extent to and the ways in which nurse prescribing has been realised or is being introduced in Western European and Anglo-Saxon countries; secondly, to identify possible mechanisms underlying the introduction and organisation of nurse prescribing on the basis of Abbott's theory on the division of professional labor.</p> <p>Methods</p> <p>A comprehensive search of six literature databases and seven websites was performed without any limitation as to date of publication, language or country. Additionally, experts in the field of nurse prescribing were consulted. A three stage inclusion process, consisting of initial sifting, more detailed selection and checking full-text publications, was performed independently by pairs of reviewers. Data were synthesized using narrative and tabular methods.</p> <p>Results</p> <p>One hundred and twenty-four publications met the inclusion criteria. So far, seven Western European and Anglo-Saxon countries have implemented nurse prescribing of medicines, viz., Australia, Canada, Ireland, New Zealand, Sweden, the UK and the USA. The Netherlands and Spain are in the process of introducing nurse prescribing. A diversity of external and internal forces has led to the introduction of nurse prescribing internationally. The legal, educational and organizational conditions under which nurses prescribe medicines vary considerably between countries; from situations where nurses prescribe independently to situations in which prescribing by nurses is only allowed under strict conditions and supervision of physicians.</p> <p>Conclusions</p> <p>Differences between countries are reflected in the jurisdictional settlements between the nursing and medical professions concerning prescribing. In some countries, nurses share (full) jurisdiction with the medical profession, whereas in other countries nurses prescribe in a subordinate position. In most countries the jurisdiction over prescribing remains predominantly with the medical profession. There seems to be a mechanism linking the jurisdictional settlements between professions with the forces that led to the introduction of nurse prescribing. Forces focussing on efficiency appear to lead to more extensive prescribing rights.</p

    A higiene das mãos: as competências profissionais e as áreas de melhoria

    Get PDF
    El objetivo fue analizar los conocimientos sobre la higiene de las manos de los profesionales del Sistema Sanitario Público Andaluz (España). Estudio mediante encuestas en 2011, utilizando el Hand Hygiene Knowledge Questionnaire for Health-Care Workers con la técnica de análisis de clases latentes. La media de respuestas correctas fue de 17,51 ± 3,68. Las preguntas con porcentajes de respuestas correctas más bajos son las referidas a la prevención, mediante la higiene de las manos, de la transmisión de microorganismos después de la exposición al paciente y aquellas relacionadas con la utilización de preparados de base alcohólica. Se obtuvo un modelo de 7 clases latentes. Principales diferencias socio-demográficas: los profesionales con conocimientos más bajos suelen ser hombres, jóvenes y no sanitarios; el haber recibido formación previa no discrimina a los que presentan excelentes conocimientos. Concluimos que la revisión de los programas de formación en higiene de las manos es necesaria para mejorar los conocimientos sobre aspectos conceptuales de la transmisión de microorganismos a través de las manos.The objective of this study was to analyze knowledge on hand hygiene among staff workers in the Andalusian Public Health System (Spain). This was a cross-sectional study with surveys (2011) using the Hand Hygiene Knowledge Assessment Questionnaire for Healthcare Workers with the latent class analysis technique. The average number of questions answered correctly was 17.51±3.68. Questions with lower percentages of correct responses were those on hand hygiene for prevention of microorganism transmission to patients and those on hand- rubbing versus hand-washing. We obtained a model with 7 latent classes. Workers with lower knowledge tended to be younger, males, and non-healthcare workers. Having received previous training did not necessarily ensure excellent knowledge. The study concludes that hand hygiene training programs need to be revised in order to improve knowledge on conceptual characteristics involved in the transmission of microorganisms via the hands.O objetivo foi analisar o conhecimento sobre a higiene das mãos dos profissionais do Sistema de Saúde Andaluz (Espanha). Os inquéritos foram realizados em 2011, por meio do questionário Hand Hygiene Knowledge Questionnaire for Health-Care Workers, usando a técnica da análise de classe latente. Questões com porcentagens mais baixas de acertos são as relacionadas com a prevenção da transmissão de micro-organismos após exposição ao paciente por higiene das mãos e aquelas relacionadas com a utilização de preparações à base de álcool. Obtivemos um modelo de sete classes latentes. Principais diferenças sociodemográficas: os profissionais de conhecimentos mais baixos são homens, jovens e profissionais não relacionados à saúde; ter recebido treinamento anterior e não discriminar as pessoas com grande conhecimento. Concluímos que é necessária a revisão dos programas de formação de higiene das mãos para melhorar o conhecimento sobre aspectos conceituais da transmissão de micro-organismos pelas mãos

    Porous ferroelectrics for energy harvesting applications

    Get PDF
    This paper provides an overview of energy harvesting using ferroelectric materials, with a particular focus on the energy harvesting capabilities of porous ferroelectric ceramics for both piezo- and pyroelectric harvesting. The benefits of introducing porosity into ferro- electrics such as lead zirconate titanate (PZT) has been known for over 30 years, but the potential advantages for energy harvesting from both ambient vibrations and temperature fluctuations have not been studied in depth. The article briefly discusses piezoelectric and pyro- electric energy harvesting, before evaluating the potential benefits of porous materials for increasing energy harvesting figures of merits and electromechanical/electrothermal coupling factors. Established processing routes are evaluated in terms of the final porous structure and the resulting effects on the electrical, thermal and mechanical properties
    • …
    corecore