63 research outputs found

    The roles of, activities of, and competencies for, community nursing services in rural Vietnam: Implications for policy decisions

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    Community health workforce plays a vital role in providing primary health care services as per the needs of residents; however, few studies have examined how nurses work within commune health centers (CHCs). Using qualitative methods including interviews and focus group discussions with key stakeholders, this study explores the roles, activities, and competencies required of community nursing services in rural districts within Vietnam. Two primary roles were identified: CHC nursing and family nursing. For the latter, in addition to providing people with general health care and health communication, they were expected to also deliver psychological care. CHC nursing fulfilled more roles and required four specific competencies: clinical care, communication, management, and planning/coordination activities. Despite these various roles serving people within a community, few ongoing efforts at either the local or national level are aimed at supporting these nurses. The study highlights the need for policy decisions via either developing a new job position policy or adapting the existing policy by integrating new roles into the existing positions of CHC nurses in Vietnam. © 2018 John Wiley & Sons, Ltd. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Nguyen Huy" is provided in this record*

    Methodological Improvements With Conductive Materials for Volume Imaging of Neural Circuits by Electron Microscopy

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    Recent advancements in electron microscope volume imaging, such as serial imaging using scanning electron microscopy (SEM), have facilitated the acquisition of three-dimensional ultrastructural information of biological samples. These advancements help build a comprehensive understanding of the functional structures in entire organelles, cells, organs and organisms, including large-scale wiring maps of neural circuitry in various species. Advanced volume imaging of biological specimens has often been limited by artifacts and insufficient contrast, which are partly caused by problems in staining, serial sectioning and electron beam irradiation. To address these issues, methods of sample preparation have been modified and improved in order to achieve better resolution and higher signal-to-noise ratios (SNRs) in large tissue volumes. These improvements include the development of new embedding media for electron microscope imaging that have desirable physical properties such as less deformation in the electron beam and higher stability for sectioning. The optimization of embedding media involves multiple resins and filler materials including biological tissues, metallic particles and conductive carbon black. These materials alter the physical properties of the embedding media, such as conductivity, which reduces specimen charge, ameliorates damage to sections, reduces image deformation and results in better ultrastructural data. These improvements and further studies to improve electron microscope volume imaging methods provide options for better scale, quality and throughput in the three-dimensional ultrastructural analyses of biological samples. These efforts will enable a deeper understanding of neuronal circuitry and the structural foundation of basic and higher brain functions

    STUDY OF NEGATIVE REFRACTIVE INDEX IN Rb FOUR-LEVEL N-TYPE ATOMIC GAS MEDIUM

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    In this work, we study the generation of a negative refractive index based on electromagnetically induced transparency (EIT) in a Rb four-level N-type atomic gas medium. We derive analytic expressions for the relative permittivity and relative permeability of the medium according to the parameters of the probe, pump, and signal laser fields. We then investigate the variation of the real parts of the relative permittivity and relative permeability with respect to the intensity and frequency of the pump and signal laser fields. In the presence of the pump laser beam, the medium becomes transparent to the probe laser beam even in the resonant region. At the same time, the real parts of the relative permittivity and relative permeability are simultaneously negative (i.e., the medium exhibits a negative refractive index) in the EIT spectral domain. In the presence of the signal laser beam, the EIT effect occurs over two different frequency domains of the probe beam, so a negative refractive index is also generated in these two frequency domains. The investigation of the real parts of the relative permittivity and relative permeability with intensity and frequency of the pump and signal laser fields allowed us to find the laser parameters for the appearance of the negative refractive index, which can be useful for experimental observations

    Intensity Distribution of the 31P¬11S+ Band System of NaLi

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    In the framework of adiabatic approximation we perform numerical calculations of intensity distribution for the 31P¬11S+ band system of NaLi based on the Franck-Condon (FC) principle. In addition, the internuclear distances at which the most favorable transitions occurred are predicted.  Comparing the calculated FC factors and the corresponding spectral lines observed recently reveals a good agreement, particularly, at node of envelop of the FC factors. Some local deviations in spectral intensity between the calculated results and experimental data indicate local perturbations in the 31P state. This result requires further investigations in details

    Controllable Optical Properties of Multiple Electromagnetically Induced Transparency in Gaseous Atomic Media

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    The advent of electromagnetically induced transparency (EIT) offered a new coherent material with exotic and controllable optical properties. Although, studies on single-EIT are described in detail for single-EIT, however, extension from single- to multi- EIT is currently of current interest due to it gains advantages in multi-channel optical communication, waveguides for optical signal processing and multi-channel quantum information processing. In this work, we review recent research works concerning multi-EIT and some related applications, as controlling group velocity of light, giant Kerr nonlinearity, optical bistability. A special attention of the review also gives for analytical interpretations of EIT spectrum, its dispersion and related applications such as EIT enhanced Kerr nonlinearity and optical bistability to give physics insight. From experimental point of view, a latest development for measuring multi-EIT spectrum and its dispersion in hot medium is presented and compared to theoretical analytical representations

    Polarization Labelling Spectroscopy for NaLi

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    We use the polarization labelling spectroscopy technique for simplification of the spectra of alkali-metal NaLi molecule. As a result, the rotational resolution observation for NaLi in the 21 electronic state is reported for the first time

    OPTICAL BISTABILITY IN A DEGENERATE TWO-LEVEL EIT MEDIUM UNDER THE INFLUENCE OF AN EXTERNAL MAGNETIC FIELD: AN ANALYTICAL APPROACH

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    We investigate the behavior of optical bistability in a degenerate two-level atomic medium using an external magnetic field to separate the lower level into two distinct levels that both connect to an upper level by the probe and coupling laser fields. Based on analytical solutions, the absorption spectrum and behavior of optical bistability in an electromagnetically induced transparency regime under an external magnetic field are investigated. By controlling the external magnetic field, we find that the appearance and disappearance of the optical bistability can be easily controlled according to the strength of the magnetic field in the transparent window domain. Furthermore, the effects of the intensity of the coupling laser field and the parameters of the system on the behavior of optical bistability are also considered. The proposed model is useful for applications in all-optical switches and magneto-optic storage devices.We investigate the behavior of optical bistability in a degenerate two-level atomic medium using an external magnetic field to separate the lower level into two distinct levels that both connect to an upper level by the probe and coupling laser fields. Based on analytical solutions, the absorption spectrum and behavior of optical bistability in an electromagnetically induced transparency regime under an external magnetic field are investigated. By controlling the external magnetic field, we find that the appearance and disappearance of the optical bistability can be easily controlled according to the strength of the magnetic field in the transparent window domain. Furthermore, the effects of the intensity of the coupling laser field and the parameters of the system on the behavior of optical bistability are also considered. The proposed model is useful for applications in all-optical switches and magneto-optic storage devices

    Dexamethasone and long-term outcome of tuberculous meningitis in Vietnamese adults and adolescents.

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    BACKGROUND: Dexamethasone has been shown to reduce mortality in patients with tuberculous meningitis but the long-term outcome of the disease is unknown. METHODS: Vietnamese adults and adolescents with tuberculous meningitis recruited to a randomised, double-blind, placebo-controlled trial of adjunctive dexamethasone were followed-up at five years, to determine the effect of dexamethasone on long-term survival and neurological disability. RESULTS: 545 patients were randomised to receive either dexamethasone (274 patients) or placebo (271 patients). 50 patients (9.2%) were lost to follow-up at five years. In all patients two-year survival, probabilities tended to be higher in the dexamethasone arm (0.63 versus 0.55; p = 0.07) but five-year survival rates were similar (0.54 versus 0.51, p = 0.51) in both groups. In patients with grade 1 TBM, but not with grade 2 or grade 3 TBM, the benefit of dexamethasone treatment tended to persist over time (five-year survival probabilities 0.69 versus 0.55, p = 0.07) but there was no conclusive evidence of treatment effect heterogeneity by TBM grade (p = 0.36). The dexamethasone group had a similar proportion of severely disabled patients among survivors at five years as the placebo group (17/128, 13.2% vs. 17/116, 14.7%) and there was no significant association between dexamethasone treatment and disability status at five years (p = 0.32). CONCLUSIONS: Adjunctive dexamethasone appears to improve the probability of survival in patients with TBM, until at least two years of follow-up. We could not demonstrate a five-year survival benefit of dexamethasone treatment which may be confined to patients with grade 1 TBM. TRIAL REGISTRATION: ClinicalTrials.gov NCT01317654

    A Comparative Study of Optical Bistability in Three-Level EIT Configurations

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    We present a comparative study of optical bistability (OB) in three-level atomic configurations, including Λ\Lambda -, cascade-, and V- types under the conditions of electromagnetically induced transparency (EIT). In the steady regime, the input-output intensity relations for the OB in each configuration have been derived in analytical form. The model allows one to construct a clear picture on how the threshold intensity, and other characteristics of the OB are continuously modified with respects to controllable parameters of the laser fields, cooperation parameter, and other physical parameters of atomic system. The results showed that the threshold intensity of OB in Λ\Lambda -type system is much less than the other ones and the threshold intensity of OB in V-type system is the largest one. The analytical result is convenient to choose excitation configuration for experimental observations and related applications in photonic devices

    EIT enhanced self-Kerr nonlinearity in the three-level lambda system under Doppler broadening

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    Using density-matrix theory, an analytical expression of the self-Kerr nonlinear coefficient of a three-level lambda EIT medium for a weak probe light is derived. Influences of the coupling light and Doppler broadening on the self-Kerr coefficient are investigated and compared to experimental observation with a good agreement. The self-Kerr nonlinearity is basically modified and greatly enhanced in the spectral region corresponding to EIT transparent window. Furthermore, sign, slope, and magnitude of the self-Kerr coefficient can be controlled with frequency and intensity of the coupling light and temperature. Such controllable Kerr nonlinearity can find interesting applications in optoelectronic devices working with low-light intensity
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