9,209 research outputs found

    A monolithic and flexible fluoropolymer film microreactor for organic synthesis applications

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    A photocurable and viscous fluoropolymer with chemical stability is a highly desirable material for fabrication of microchemical devices. Lack of a reliable fabrication method, however, limits actual applications for organic reactions. Herein, we report fabrication of a monolithic and flexible fluoropolymer film microreactor and its use as a new microfluidic platform. The fabrication involves facile soft lithography techniques that enable partial curing of thin laminates, which can be readily bonded by conformal contact without any external forces. We demonstrate fabrication of various functional channels (similar to 300 mu m thick) such as those embedded with either a herringbone micromixer pattern or a droplet generator. Organic reactions under strongly acidic and basic conditions can be carried out in this film microreactor even at elevated temperature with excellent reproducibility. In particular, the transparent film microreactor with good deformability could be wrapped around a light-emitting lamp for close contact with the light source for efficient photochemical reactions with visible light, which demonstrates easy integration with optical components for functional miniaturized systems.open1112Ysciescopu

    Possible flat band bending of the Bi1.5Sb0.5Te1.7Se1.3 crystal cleaved in an ambient air probed by terahertz emission spectroscopy

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    We investigate an evolution of the surface electronic state of the Bi1.5Sb0.5Te1.7Se1.3 single crystal, which is one of the most bulk insulating topological insulators, by examining terahertz light emitted from the sample surface upon the illumination of the near-infrared femtosecond laser pulses. We find that the surface state with a flat band bending can appear in the course of the natural maturation process of the surface state in an ambient air. Furthermore, we demonstrate that the evolution of the surface electronic state can be accelerated, decelerated, or even stopped by controlling environmental conditions to contain different amount of H2O, in particular.1121Ysciescopu

    Effects of Rosiglitazone on the Expression of PPAR-&#947 and the Production of IL-6 and IL-8 in Acute Lung Injury Model Using Human Pulmonary Epithelial Cells

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    Purpose: Peroxisome proliferator-activated receptor (PPAR)-γ ligand is known to repress the expression of pro-inflammatory mediators. However, it is unclear how it affects PPAR-γ expression and the inflammatory response in the human lung. We investigated the effects of rosiglitazone (synthetic PPAR-γ ligand) on the PPAR-γ expression and on the IL-6 and IL-8 production in acute lung injury model using human lung epithelial cells.Methods: A549 and Beas-2B cells were pre-treated with rosiglitazone and/or BADGE (selective PPAR-γ antagonist) and then treated with media control or cytokine mixture including TNF-α, IL-1 β, and IFN-γ. PPAR-γ expression was analyzed in cell lysates by Western blot. IL-6 and IL-8 production was measured in the culture supernatants by ELISA.Results: PPAR-γ expression was identified in all experimental groups except for the control. The cytokine mixture-induced IL-6 and IL-8 production was significantly inhibited by pre-treatment with rosiglitazone (P<0.01). However, this inhibitory effect of rosiglitazone was not reversed by BADGE.Conclusion: These suggest that rosiglitazone induces the PPAR-γ expression and it may inhibit the cytokine mixture-induced IL-6 and IL-8 production through the PPAR-γ independent pathway. The inhibitory mechanisms of rosiglitazone on the cytokine mixture-induced IL-6 and IL-8 production in human alveolar and bronchial epithelial cells remain to be further investigated.Keywords: Rosiglitazone, PPAR-γ, IL-6, IL-8, Acute lung injur

    Effects of Rosiglitazone on the Expression of PPAR-&#947 and on the Production of IL-6 and IL-8 in Acute Lung Injury Model Using Human Pulmonary Epithelial Cells

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    Purpose: Peroxisome proliferator-activated receptor (PPAR)-γ ligand is known to repress the expression of pro-inflammatory mediators. However, it is unclear how it affects PPAR-γ expression and the inflammatory response in the human lung. We investigated the effects of rosiglitazone (synthetic PPAR-γ ligand) on the PPAR-γ expression and on the IL-6 and IL-8 production in acute lung injury model using human lung epithelial cells.Methods: A549 and Beas-2B cells were pre-treated with rosiglitazone and/or BADGE (selective PPAR-γ antagonist) and then treated with media control or cytokine mixture including TNF-α, IL-1β, and IFN-γ. PPAR-γ expression was analyzed in cell lysates by Western blot. IL-6 and IL-8 production was measured in the culture supernatants by ELISA.Results: PPAR-γ expression was identified in all experimental groups except for the control. The cytokine mixture-induced IL-6 and IL-8 production was significantly inhibited by pre-treatment with rosiglitazone (P<0.01). However, this inhibitory effect of rosiglitazone was not reversed by BADGE. Conclusion: These suggest that rosiglitazone induces the PPAR-γ expression and it may inhibit the cytokine mixture-induced IL-6 and IL-8 production through the PPAR-γ independent pathway. The inhibitory mechanisms of rosiglitazone on the cytokine mixture-induced IL-6 and IL-8 production in human alveolar, and bronchial epithelial cells remain to be further investigated.Keywords: Rosiglitazone, PPAR-γ expression, IL-6, IL-8, Acute lung injur

    Fundamental mechanisms of telomerase action in yeasts and mammals: understanding telomeres and telomerase in cancer cells

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    Aberrant activation of telomerase occurs in 85-90% of all cancers and underpins the ability of cancer cells to bypass their proliferative limit, rendering them immortal. The activity of telomerase is tightly controlled at multiple levels, from transcriptional regulation of the telomerase components to holoenzyme biogenesis and recruitment to the telomere, and finally activation and processivity. However, studies using cancer cell lines and other model systems have begun to reveal features of telomeres and telomerase that are unique to cancer. This review summarizes our current knowledge on the mechanisms of telomerase recruitment and activation using insights from studies in mammals and budding and fission yeasts. Finally, we discuss the differences in telomere homeostasis between normal cells and cancer cells, which may provide a foundation for telomere/telomerase targeted cancer treatments

    Management of hypoxaemia in the critically ill patient.

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    Hypoxaemia is a common presentation in critically ill patients, with the potential for severe harm if not addressed appropriately. This review provides a framework to guide the management of any hypoxaemic patient, regardless of the clinical setting. Key steps in managing such patients include ascertaining the severity of hypoxaemia, the underlying diagnosis and implementing the most appropriate treatment. Oxygen therapy can be delivered by variable or fixed rate devices, and non-invasive ventilation; if patients deteriorate they may require tracheal intubation and mechanical ventilation. Early critical care team involvement is a key part of this pathway. Specialist treatments for severe hypoxaemia can only be undertaken on an intensive care unit and this field is developing rapidly as trial results become available. It is important that each new scenario is approached in a structured manner with an open diagnostic mind and a clear escalation plan

    Organic bilayer photovoltaics for efficient indoor light harvesting

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    Indoor organic photovoltaics (OPVs) are a potential niche application for organic semiconductors due to their strong and well-matched absorption with the emission of indoor lighting. However, due to extremely low photocurrent generation, the device parameters critical for efficient indoor OPVs differ from those under 1 Sun conditions. Herein, these critical device parametersā€”recombination loss and shunt resistance (Rsh)ā€”are identified and it is demonstrated that bilayer OPVs are suitable for indoor PV applications. Compared to bulk-heterojunction (BHJ), the open-circuit voltage loss of bilayer devices under low light intensities is much smaller, consistent with a larger surface photovoltage response, indicating suppressed recombination losses. The bilayer devices show a higher fill factor at low light intensities, resulting from high Rsh afforded by the ideal interfacial contacts between the photoactive and the charge transport layers. The high Rsh enables bilayer devices to perform well without a light-soaking process. Finally, the charge carriers are extracted rapidly in bilayers, which are attributed to strongly suppressed trap states possibly induced by isolated domains and non-ideal interfacial contacts in BHJs. This study highlights the excellent suitability of bilayer OPVs for indoor applications and demonstrates the importance of device architecture and interfacial structures for efficient indoor OPVs

    Turning to Peers: Integrating Understanding of the Self, the Condition, and Othersā€™ Experiences in Making Sense of Complex Chronic Conditions

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    People are increasingly involved in the self-management of their own health, including chronic conditions. With technology advances, the choice of self-management practices, tools, and technologies has never been greater. The studies reported here investigated the information seeking practices of two different chronic health populations in their quest to manage their health conditions. Migraine and diabetes patients and clinicians in the UK and the US were interviewed about their information needs and practices, and representative online communities were explored to inform a qualitative study. We found that people with either chronic condition require personally relevant information and use a broad and varied set of practices and tools to make sense of their specific symptoms, triggers, and treatments. Participants sought out different types of information from varied sources about themselves, their medical condition, and their peersā€™ experiences of the same chronic condition. People with diabetes and migraine expended great effort to validate their personal experiences of their condition and determine whether these experiences were ā€˜normalā€™. Based on these findings, we discuss the need for future personal health technologies that support people in engaging in meaningful and personalised data collection, information seeking, and information sharing with peers in flexible ways that enable them to better understand their own condition

    Using a Clinic-based Screening Tool for Primary Care Providers to Identify Commercially Sexually Exploited Children

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    Introduction: Commercial Sexual Exploitation of Children (CSEC), which encompasses acts of domestic minor sex trafficking, is a hidden problem in the U.S. that affects an estimated 300,000 children. Significant health impacts to victims include violence, substance abuse, mental illness, sexually transmitted diseases, and unintended pregnancy. However, due to the covert nature of sexual exploitation, the lack of understanding among service providers and law enforcement, and complex psychological factors experienced by victims, identifying CSEC is a tremendous challenge. Primary care providers can play a critical role in identifying CSEC victims within clinical settings to help address this silent epidemic. Objective: The goal of this project was to assess the prevalence of CSEC using a clinic-based screening tool within a community health center serving indigent populations, with a large proportion of the patients being of Asian and Pacific Islander descent. Methods: Medical charts were reviewed of young female patients (n=621) between 13-23 years of age and seeking clinical services in Asian Health Servicesā€™ Teen Clinic from 2008 through 2011, during the implementation of a clinic-based CSEC screening tool used by primary care providers. The CSEC screening tool consists of two questions about sexual exploitation. Results: Of the 621 patients in the study, 57.5% were Asian and Pacific Islander. Clinical providers applied the CSEC screening tool on 28.5% (n=177) of female patients in the study. Of the 177 patients who were screened, 7.3% (n=13) responded positive to questions about commercial sexual exploitation. Discussion: Using a clinic-based screening tool with patients who have identified risk factors helps primary care providers identify CSEC victims and link them to available resources. Under-reporting among victims and under-screening among providers remain major considerations in estimating CSEC prevalence. To address under-screening, it is important to raise awareness among primary care providers around the CSEC epidemic and their potential role for intervention, including screening for a history of sexual exploitation among youth patients

    PUK21 LONG-TERM COST-EFFECTIVENESS OF SIROLIMUS BASED REGIMEN COMPARED WITH CALCINEURIN INHIBITOR BASED REGIMENS IN LOWER IMMUNOLOGICAL RISK RENAL TRANSPLANT RECIPIENTS IN KOREA

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