Determinants Influencing Liquidity of Listed Steel Firms in Vietnam

This study is conducted to investigate the impact levels of determinants influencing liquidity of listed steel firms on Vietnam Stock Exchange. Data were collected from audited financial statements of 25 listed food processing firms from 2014 to 2017. This research employs the least squares method (OLS) and tests to determine the influence of factors on the liquidity of listed sample firms. The results indicate that return on assets (ROA), operating period (AGE) and asset structure (AS) have positive impacts on the liquidity. In contrast, the firm size and debt ratio has the opposite effects. Based on the findings, a number of recommendations are proposed to increase the liquidity ratio of listed firms in the future. Keywords: Liquidity, steel firms, determinants, Vietnam Stock Exchange DOI: 10.7176/EJBM/11-7-10 Publication date:March 31st 201

Detection of a Sudan dye at low concentrations by surface-enhanced Raman spectroscopy using silver nanoparticles

Sudan dyes are red colorants banned from use for food due to their toxic properties. However, because of the cheapness, they are sometimes adulterated into food illegally. Currently surface-enhanced Raman spectroscopy (SERS) is emerging as a good method to detect residues (including trace amounts) of Sudan dyes in food. In this report we present the SERS detection of Sudan I (a type of Sudan dyes) to concentrations as low as 1 ppb, using a very simple SERS substrate, which is made from silver nanoparticles chemically deposited on silicon surface

The Photocatalytic Activity of the Bi2O3-B2O3-ZnO-TiO2 Glass Coating

Due to the low melting temperature, the glazes based on the Bi2O3-B2O3-ZnO system are used as coatings on the surface of industrial glass substrates. Moreover, the composition of these coatings does not contain PbO, meeting the optical and environmental properties requirements. In this study, TiO2 was used in the Bi2O3-B2O3-ZnO glaze system to improve its photocatalytic ability. This can be considered a four – component glass system Bi2O3-B2O3-ZnO-TiO2. The heating microscopy results show that the melting temperature of the glaze system is 606 °C. The Fourier transform infrared spectroscopy results show that the TiO2 polyhedra are located independently in the structure without participating in forming a glass network. Thanks to that, the photocatalytic properties of TiO2 are maintained. The X-ray diffraction patterns results show that the formed TiO2 nanocrystals are rutile and anatase crystals. The results of determining the band gap energy using UV-Vis show that the band gap energy of the base glaze system increases with the addition of TiO2. The methylene blue decomposition results also showed that the ability to decompose organic increased when TiO2 was added to the glaze coating. The characteristics such as melting temperature, microstructure, and photocatalytic capacity of Bi2O3-B2O3-ZnO-TiO2 white glazes (5 and 10 % weight of TiO2) also were indicated in this paper

Development of a solar/LED lighting system for a plant tissue culture room

As the green energy, sunlight provides a friendly-environment and reduces electricity used for lighting. Our target is to enhance the use of natural energy and minimize the consumption of electricity for improving indoor environments. For this reason, a hybrid lighting system, combining sunlight with LEDs for plant tissue culture, are presented. The optical fiber daylighting system consists of three main parts: concentration, collimation beam, and transportation. The concentration part is formed by Fresnel lenses to collect and focus the sunlight into a small area by a non-imaging optical effect. The collimation part consists of optical filters and collimator lenses; the optical filters are used to reflect the ultraviolet (UV) and near infrared (NIR) regions, therefore, only the visible range of the solar light can be transmitted. The transportation part is a large-core optical fiber bundle. To increase the coupling efficiency, the collimator lens is used to expand and to collimate the focused light beam. The collimated light beam is then transported by the optical fiber bundle into a plant tissue culture room. In order to keep the plant tissue culture room at a constant illumination, a lighting control system based on LEDs is used to compensate variations of the natural light. In this paper, a prototype of optical fiber daylighting system and our proposed application will be presented.Ánh sáng mặt trời, một nguồn năng lượng xanh, được sử dụng cho chiếu sáng nhằm mang lại nguồn ánh sáng thân thiện với môi trường và giảm điện năng. Mục tiêu của chúng tôi là tăng cường sử dụng năng lượng tự nhiên và linh kiện tiêu thụ điện thấp để cải thiện môi trường ánh sáng trong nhà và giảm tiêu thụ điện cho chiếu sáng. Vì lý do này, một hệ thống chiếu sáng kết hợp ánh sáng mặt trời với đèn LED để nuôi cấy mô thực vật sẽ được trình bày. Hệ thống chiếu sáng ban ngày bằng sợi quang bao gồm ba phần chính:Bộ phận thu nhận và hội tụ ánh sáng, bộ phận chuẩn trực chùm sáng và bộ phận vận chuyển ánh sáng mặt trời tới nơi cần chiếu sáng. Phần tập trung được hình thành bởi một thấu kính Fresnel để thu thập và hội tụ ánh sáng mặt trời vào một vùng nhỏ bằng hiệu ứng quang học không tạo ảnh. Bộ phận chuẩn trực chumg sáng bao gồm bộ lọc quang học và thấu kính chuẩn trực. Bộ phận vận chuyển là các bó sợi quang lõi lớn. Bộ lọc quang học được sử dụng để phản xạ vùng cực tím (UV) và vùng hồng ngoại gần (NIR), chỉ cho phần ánh sáng nhìn thấy truyền qua. Để tăng hiệu quả ghép nối, thấu kính chuẩn trực được sử dụng để mở rộng và chuẩn trực chùm ánh sáng hội tụ. Chùm sáng chuẩn trực sau đó được vận chuyển bởi bó sợi quang vào phòng nuôi cấy mô thực vật. Để giữ cho phòng nuôi cấy mô thực vật được chiếu sáng liên tục, một hệ thống điều khiển ánh sáng dựa trên đèn LED để bù lại sự biến đổi của ánh sáng tự nhiên. Trong bài báo này, một nguyên mẫu của hệ thống chiếu sáng ban ngày bằng sợi quang và ứng dụng đề xuất của hệ thống sẽ được trình bày

Overseas Treatment of Latent Tuberculosis Infection in US-Bound Immigrants.

Seventy percent of tuberculosis (TB) cases in the United States occur among non-US-born persons; cases usually result from reactivation of latent TB infection (LTBI) likely acquired before the person's US arrival. We conducted a prospective study among US immigrant visa applicants undergoing the required overseas medical examination in Vietnam. Consenting applicants >15 years of age were offered an interferon-γ release assay (IGRA); those 12-14 years of age received an IGRA as part of the required examination. Eligible participants were offered LTBI treatment with 12 doses of weekly isoniazid and rifapentine. Of 5,311 immigrant visa applicants recruited, 2,438 (46%) consented to participate; 2,276 had an IGRA processed, and 484 (21%) tested positive. Among 452 participants eligible for treatment, 304 (67%) initiated treatment, and 268 (88%) completed treatment. We demonstrated that using the overseas medical examination to provide voluntary LTBI testing and treatment should be considered to advance US TB elimination efforts

Severe Pandemic H1N1 2009 Infection Is Associated with Transient NK and T Deficiency and Aberrant CD8 Responses

BACKGROUND: It is unclear why the severity of influenza varies in healthy adults or why the burden of severe influenza shifts to young adults when pandemic strains emerge. One possibility is that cross-protective T cell responses wane in this age group in the absence of recent infection. We therefore compared the acute cellular immune response in previously healthy adults with severe versus mild pandemic H1N1 infection. METHODS AND PRINCIPAL FINDINGS: 49 previously healthy adults admitted to the National Hospital of Tropical Diseases, Viet Nam with RT-PCR-confirmed 2009 H1N1 infection were prospectively enrolled. 39 recovered quickly whereas 10 developed severe symptoms requiring supplemental oxygen and prolonged hospitalization. Peripheral blood lymphocyte subset counts and activation (HLADR, CD38) and differentiation (CD27, CD28) marker expression were determined on days 0, 2, 5, 10, 14 and 28 by flow cytometry. NK, CD4 and CD8 lymphopenia developed in 100%, 90% and 60% of severe cases versus 13% (p<0.001), 28%, (p = 0.001) and 18% (p = 0.014) of mild cases. CD4 and NK counts normalized following recovery. B cell counts were not significantly associated with severity. CD8 activation peaked 6-8 days after mild influenza onset, when 13% (6-22%) were HLADR+CD38+, and was accompanied by a significant loss of resting/CD27+CD28+ cells without accumulation of CD27+CD28- or CD27-CD28- cells. In severe influenza CD8 activation peaked more than 9 days post-onset, and/or was excessive (30-90% HLADR+CD38+) in association with accumulation of CD27+CD28- cells and maintenance of CD8 counts. CONCLUSION: Severe influenza is associated with transient T and NK cell deficiency. CD8 phenotype changes during mild influenza are consistent with a rapidly resolving memory response whereas in severe influenza activation is either delayed or excessive, and partially differentiated cells accumulate within blood indicating that recruitment of effector cells to the lung could be impaired