Magnetotransport studies of Fe vacancy-ordered Fe4+δSe5 nanowires.

We studied the electrical transport of Fe4+δSe5 single-crystal nanowires exhibiting √5 × âˆš5 Fe-vacancy order and mixed valence of Fe. Fe4+δSe5 compound has been identified as the parent phase of FeSe superconductor. A first-order metal-insulator (MI) transition of transition temperature T MI ∼ 28 K is observed at zero magnetic fields (B). Colossal positive magnetoresistance emerges, resulting from the magnetic field-dependent MI transition. T MI demonstrates anisotropic magnetic field dependence with the preferred orientation along the c axis. At temperature T < ∼17 K, the state of near-magnetic field-independent resistance, which is due to spin polarized even at zero fields, preserves under magnetic fields up to B = 9 T. The Arrhenius law shift of the transition on the source-drain frequency dependence reveals that it is a nonoxide compound with the Verwey-like electronic correlation. The observation of the magnetic field-independent magnetoresistance at low temperature suggests it is in a charge-ordered state below T ∼ 17 K. The results of the field orientation measurements indicate that the spin-orbital coupling is crucial in √5 × âˆš5 Fe vacancy-ordered Fe4+δSe5 at low temperatures. Our findings provide valuable information to better understand the orbital nature and the interplay between the MI transition and superconductivity in FeSe-based materials.

Role of the extra Fe in K2-x Fe4+y Se5 superconductors.

The exact superconducting phase of K2-x Fe4+y Se5 has so far not been conclusively decided since its discovery due to its intrinsic multiphase in early material. In an attempt to resolve this mystery, we have carried out systematic structural studies on a set of well-controlled samples with exact chemical stoichiometry K2-x Fe4+x Se5 (x = 0-0.3) that are heat-treated at different temperatures. Using high-resolution synchrotron radiation X-ray diffraction, our investigations have determined the superconducting transition by focusing on the detailed temperature evolution of the crystalline phases. Our results show that superconductivity appears only in those samples that have been treated at high-enough temperature and then quenched to room temperature. The volume fraction of superconducting transition strongly depends on the annealing temperature used. The most striking result is the observation of a clear contrast in crystalline phase between the nonsuperconducting parent compound K2Fe4Se5 and the superconducting K2-x Fe4+y Se5 samples. The X-ray diffraction patterned can be well indexed to the phase with I4/m symmetry in all temperatures investigated. However, we need two phases with similar I4/m symmetry but different parameters to best fit the data at a temperature below the Fe vacancy order temperature. The results strongly suggest that superconductivity in K2-x Fe4+y Se5 critically depends on the occupation of Fe atoms on the originally empty 4d site.

High-performance 1-10 THz integrating sphere.

The SPICA far-infrared instrument (SAFARI), one of instruments of the space infrared telescope for cosmology and astrophysics, requires a calibration source assembly to calibrate the transition edge sensor readout circuits. A high-performance integrating sphere working at SAFARI wavelength (34-230 µm) is essential. A novel process for preparing terahertz integrating spheres was developed. The aluminum surfaces after sandblasting, wet-etching, and gold plating processes demonstrate rough morphology but high reflectance of 0.91 in 1-10 THz. The spatial distribution of the measured output power excellently agrees with the numerical simulation results based on the assumption of uniform surface radiation at the output port.

Non-health outcomes affecting self-care behaviors and medical decision-making preference in patients with type 2 diabetes: a cross-sectional study.

BACKGROUND: The effects of patient sustained self-care behaviors on glycemic control are even greater than the effects of medical treatment, indicating the value of identifying the factors that influence self-care behaviors. To date, these factors have not been placed in a single model to clarify the critical path affecting self-care behaviors. The aims of this study were to explore the relationships of these factors and the differences in patient preference for medical decision-making. METHODS: A cross-sectional study was conducted among outpatients with type 2 diabetes at a regional teaching hospital. Purposive sampling was adopted to recruit 316 eligible patients via self-administered questionnaires. Partial least squares structural equation modeling was used for analysis. RESULTS: Significant direct pathways were identified from health literacy to self-efficacy, patient empowerment, and self-care behaviors; from self-efficacy to self-care behaviors; and from patient empowerment to self-care behaviors. Indirect pathways were from health literacy to self-care behaviors via self-efficacy or patient empowerment. The pathway from health literacy to self-efficacy was significantly stronger in those preferring shared decision-making than in those who preferred physician decision-making. CONCLUSIONS: Health literacy is a critical factor in improving self-care behaviors in patients with type 2 diabetes, and the effect of health literacy on self-efficacy was more significant in the shared decision-making than in the physician decision-making. Therefore, developing an effective health strategy to strengthen health literacy awareness and designing friendly, diverse health literacy materials, and application tools is the most important factor to facilitate self-care behaviors in this population.

Fe-vacancy order and superconductivity in tetragonal ß-Fe1-xSe.

Several superconducting transition temperatures in the range of 30-46 K were reported in the recently discovered intercalated FeSe system (A1-xFe2-ySe2, A = K, Rb, Cs, Tl). Although the superconducting phases were not yet conclusively decided, more than one magnetic phase with particular orders of iron vacancy and/or potassium vacancy were identified, and some were argued to be the parent phase. Here we show the discovery of the presence and ordering of iron vacancy in nonintercalated FeSe (PbO-type tetragonal ß-Fe1-xSe). Three types of iron-vacancy order were found through analytical electron microscopy, and one was identified to be nonsuperconducting and magnetic at low temperature. This discovery suggests that the rich-phases found in A1-xFe2-ySe2 are not exclusive in Fe-Se and related superconductors. In addition, the magnetic ß-Fe1-xSe phases with particular iron-vacancy orders are more likely to be the parent phase of the FeSe superconducting system instead of the previously assigned ß-Fe1+δTe.

Substrate Charge Transfer Induced Ferromagnetism in MnSe/SrTiO3 Ultrathin Films.

The observation of superconductivity in MnSe at 12 GPa motivated us to investigate whether superconductivity could be induced in MnSe at ambient conditions. A strain-induced structural change in the ultrathin film could be one route to the emergence of superconductivity. In this report, we present the physical property of MnSe ultrathin films, which become tetragonal (stretched ab-plane and shortened c-axis) on a (001) SrTiO3 (STO) substrate, prepared by the pulsed laser deposition (PLD) method. The physical properties of the tetragonal MnSe ultrathin films exhibit very different characteristics from those of the thick films and polycrystalline samples. The tetragonal MnSe films show substantial conductivity enhancement, which could be associated with the presence of superparamagnetism. The optical absorption data indicate that the electron transition through the indirect bandgap to the conduction band is significantly enhanced in tetragonal MnSe. Furthermore, the X-ray Mn L-edge absorption results also reveal an increase in unoccupied state valance bands. This theoretical study suggests that charge transfer from the substrate plays an important role in conductivity enhancement and the emergence of a ferromagnetic order that leads to superparamagnetism.

CCT- and CRI-tuning of white light-emitting diodes using three-dimensional non-close-packed colloidal photonic crystals with photonic stop-bands.

This study exhibited the correlated color temperature (CCT)- and color-rendering index (CRI)-tuning behavior of light emission from white light-emitting diodes (WLEDs) using three-dimensional non-close-packed (3D NCP) colloidal photonic crystals (CPhCs). The CCT of approximately 5300 K (characteristic of cold WLEDs) of white light propagated through the NCP CPhCs dropped to 3000 K (characteristic of warm WLEDs) because of the photonic stop-bands based on the photonic band structures of NCP CPhCs. This study successfully developed a novel technique that introduces lower-cost CCT- and CRI-tuning cold WLEDs with a CRI of over 90 that of warm WLEDs by using 3D NCP CPhCs.

Recent advances in ß-FeSe1-x and related superconductors.

It has been more than four years since the discovery of ß-FeSe1-x superconductors. Through the efforts of many outstanding research groups, unprecedented advances in the field have been achieved. High-quality single crystals of ß-FeSe1-x and related compounds have been prepared by various techniques, allowing us to explore in detail the physical properties of this class of materials. Detailed characterizations of the structure and properties of these crystals have helped us to understand the origin of superconductivity in ß-FeSe1-x . The occurrence of superconductivity is associated with the low-temperature structure distortion, which is accompanied by several anomalies. Recent measurements on quasiparticle and acoustic phonon dynamics with respect to the orbital modification in ß-FeSe1-x suggest the opening of an energy gap below 130-140 K, accompanied by a coincident transfer of optical spectral weight in the visible range and alterations in transport properties. These observations provide convincing evidence that the modification of the electronic structure occurs prior to the lattice distortion. They further suggest that the high-temperature gap and the lattice symmetry breaking are driven by short-range orbital and/or charge orders.

Strategies for Improving the Utilization of Preventive Care Services: Application of Importance-Performance Gap Analysis Method.

The utilization of preventive care services is limited. Previous studies based on communities have looked at many types of barriers to preventive care (i.e., why not do). This study aimed to gain an insight into the key factors and performance gaps (i.e., why do and how to do) of people who attended a regional teaching hospital to undergo health check-ups using a purposive sampling method to recruit people to complete a self-administered questionnaire. Paired sample t-tests and importance-performance gap and regression analyses were performed. The results indicated that the participants' wish to understand their health status, the quality of medical devices and the completeness of items, and process layout planning were the key factors that affect people's health check-up behavior. Promoting the effectiveness of hospital performance may improve the positive cycle of people's health check-up behavior from the community to the hospital. Continuing to promote the knowledge of preventive care services is necessary, and it is very important for people to have a good experience of undergoing health check-ups in the hospital. Important strategies for improving the utilization of preventive care services may include: meeting the person's personalization needs, improving the quality of medical devices and the completeness of items, and having appropriate process layout planning, a detailed interpretation of the results, and further follow-ups in the hospital.

Improving Patient Health Literacy in Hospitals - A Challenge for Hospital Health Education Programs.

BACKGROUND: The health literacy of hospital patients has become a very important issue, especially in the face of emerging infectious diseases. The design of and measures used by hospitals, however, have not yet taken into account whether patients can develop their health literacy through the process of medical treatment. Hospitals should take on this role as part of health education programs. METHODS: A cross-sectional survey was conducted at pre-admission testing center patients waiting to be hospitalized in a regional teaching hospital. A purposive sampling method was used to recruit 406 patients via self-administered questionnaires. RESULTS: Among the 406 participants, 36.1% had adequate health literacy. There were significant differences in age, education attainment, and history of chronic diseases for health literacy. The ability to find and judge information on health was lower. Watching health-related TV programs was positively correlated with health literacy. Health literacy, health promotion literacy, and understanding information on health were positively correlated to self-care and management. 65.8% of patients did not understand the treatment for which they were being admitted. Health literacy, healthcare health literacy, the ability to judge health information were positively related to understanding the treatment. CONCLUSION: Health literacy is a critical facilitating factor in improving self-care and management and understanding treatment on admission. Health education programs cannot, however, be one-size-fits-all. To help patients change their behavior, the change must be made easy. To this end, health information in the form of entertainment programs and simplified materials may be useful and even necessary.

Glycemic control in type 2 diabetes: role of health literacy and shared decision-making.

Background: Improving glycemic control requires that patients actively participate in decisions about how to best live with the disease and adapt to the realities of self-care. Limited health literacy (HL) is related to poorer health outcomes and may make it difficult for patients to participate in shared decision-making (SDM). As such, understanding the relationship between HL and SDM and its impact on diabetes control is an urgent issue. Methods: A cross-sectional survey was conducted among outpatients with type 2 diabetes in a regional teaching hospital. Purposive sampling was used to recruit eligible 372 patients via self-administered questionnaires. HbA1C values were obtained from each patient's laboratory assay. Results: Among the 372 participants, 50.4% of patients preferred physician decision-making, 39.3% preferred SDM, and 10.3% preferred patient decision-making. The physician explaining the illness in colloquial language, having adequate time for discussion, and encouragement from the healthcare provider were the major factors influencing patients' involvement in SDM. Interactive HL and critical HL had positive correlations with patients' perceived involvement in SDM. Educational attainment and HL were positively related. The HbA1C values for patient decision-making and physician decision-making were approximately 1.4 times and 1.24 times higher than those of SDM, respectively. Conclusion: SDM led to better glycemic control. HL increased patients' perceived involvement in SDM. Therefore, it is necessary to improve levels of HL based on the educational attainment of patients. Physicians explaining illness in colloquial language is the key factor in promoting patients' perceived involvement in SDM.

Study on doctor shopping behavior: insight from patients with upper respiratory tract infection in Taiwan.

OBJECTIVES: Based on the actual medical records of ambulatory care visits, this study analyzed patients' healthcare seeking behavior and doctor shopping behavior (DSB), and investigated the underlying factors and the impact on the depletion of the healthcare resources for health policy makers to build a better health delivery system. METHODS: Among a cohort comprised of 200,000 patients randomly chosen from the National Health Insurance Research Database of Taiwan in 2004, only the patients seeking ambulatory care visits for upper respiratory tract infection (URI) were analyzed. RESULTS: Among the 45,951 URI patients, 2875 of them exhibited DSB (prevalence 6.3%). The DSB showed a reverse U-shaped relationship with the patient age (the highest DSB in age 18-34 years). The episodes of the URI had a negative impact on the DSB. The odds ratios of gender and the frequency of consultation versus DSB were 1.10 and 4.72, respectively, and the depletion of days of medication and repeat prescription increased with doctor shopping. CONCLUSIONS: Health education to raise DSB awareness is necessary, especially for female's age 18-34 years. Implementing a proper referral system with efficient data exchange, setting up control parameters in the IC cards, and strengthening the integrated care plan could reduce the unnecessary waste of the healthcare resources.