Structure and Electrochemical Impedance of LiNix_{x}Mn2−x_{2 - x}O4_{4}

Ni-substitution spinel LiNixMn2−xO4 (x = 0, 0.1, 0.2) materials were synthesized by the sol--gel method. The structure and  morphology of the samples were characterized by the X-ray diffraction (XRD)  and the scanning electron microscopy. The ac conduction of the materials was  investigated by electrochemical impedance spectroscopy (EIS) measurements.  The refinement results showed that the substitution of Ni decreased the  lattice constant and Mn--O distance, while increased Li--O bond length and  16c octahedral volume. The EIS results confirmed the decrease of  conductivity with increasing Ni substitution content. Based on XRD and EIS  results, the relationship between the crystal structure and electrochemical  behavior of the materials was discussed and explained

A Phase 2/3 double blinded, randomized, placebo-controlled study in healthy adult participants in Vietnam to examine the safety and immunogenicity of an inactivated whole virion, alum adjuvanted, A(H5N1) influenza vaccine (IVACFLU-A/H5N1)

Abstract Background A global shortfall of vaccines for avian influenza A(H5N1) would occur, especially in low- and-middle income countries, if a pandemic were to occur. To address this issue, development of a pre-pandemic influenza vaccine was initiated in 2012, leveraging a recently established influenza vaccine manufacturing capacity in Vietnam. Methods This was a Phase 2/3, double-blinded, randomized, placebo-controlled study to test the safety and immunogenicity of IVACFLU-A/H5N1 vaccine in healthy adults. Phase 2 was a dose selection study, in which 300 participants were randomized to one of the three groups (15 mcg, 30 mcg, or placebo). Safety and immunogenicity were assessed in all participants. In Phase 3, 630 participants were randomized to receive the IVACFLU-A/H5N1 vaccine dose selected in Phase 2 (15 mcg, n = 525) or placebo (n = 105). Safety was assessed in all Phase 3 participants and immunogenicity was measured in a subset of participants. Results The vaccine was well tolerated and most of the adverse events were mild and of short duration. Mild pain at the injection site was the most common adverse event seen in 60 percent of participants in the vaccine group in Phase 3. In Phase 2, both 15 mcg and 30 mcg doses were immunogenic, so the lower dose was selected for further testing in Phase 3. In Phase 3 overall seroconversion rates were 68 percent for hemagglutination inhibition (HI), 51 percent for microneutralization (MN) and 56 percent for single radial hemolysis (SRH). The seroprotection rates were 44 percent for HI, 41 percent for MN and 55 percent for SRH. The GMT ratio was 5.31 and 3.7 for HI and MN respectively; GMA was 4.75 for the SRH. Conclusion The IVACFLU A/H5N1 was safe and immunogenic. Development of this pandemic avian influenza vaccine is a welcome addition to the limited global pool of these vaccines. ClinicalTrials.gov register NCT02612909

Clinical, epidemiological, and socioeconomic analysis of an outbreak of Vibrio parahaemolyticus in Khanh Hoa Province, Vietnam.

From 1996 onward, a pandemic spread of Vibrio parahaemolyticus infections due to one clone has been reported in several Asian countries. During a population-based study that relied on passive surveillance, 548 cases of V. parahaemolyticus infection were detected between 1997 and 1999 in the Khanh Hoa province of Vietnam. Detection of cases of V. parahaemolyticus infection abruptly stopped in November 1999, although Vibrio species other than V. parahaemolyticus continued to be isolated throughout 2000. Of the infections, 90% occurred in individuals >5 years old; 53% of the patients presented with watery stools, and 6% reported blood in their stools. All patients had recovered by the time of discharge. A surprising risk factor for V. parahaemolyticus infections was high socioeconomic status. Like the interruption of the transmission of V. cholerae infections that had been observed earlier, the transmission of V. parahaemolyticus came to a halt without meteorological changes or changes in water supply and sanitation

Fabrication and characteristics of Zn1–xSnxO nanorod/ITO composite photocatalytic films

Zn _1−x Sn _x O NRs/ITO composite photocatalytic films were fabricated by the hydrothermal method. A concentration of Sn dopant in Zn _1−x Sn _x O nanorods (NRs) was varied from 0% to 7%. The structural and surface morphology characteristics of Zn _1−x Sn _x O NRs/ITO composite photocatalytic films were investigated by X-Ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. In addition, photocatalytic properties of synthesized materials were evaluated by degradation rates of Rhodamine-B aqueous solutions under UV light irradiation. The SEM results indicated that, with an increasing concentration of Sn dopant in Zn _1−x Sn _x O NRs/ITO, the effective surface areas were declined by an exponential decay function and the reduction was negligible as the Sn doping concentration was higher than 3%. With the similarity in effective surface area, the contribution of Sn in the enhancement of the photocatalytic activity of Zn _0.93 Sn _0.07 O NRs/ITO is clearly observed with 41% improvement in comparison to ZnO NRs/ITO

Apply Optimarin Ballast System for Vietnam’s Fleet to Prevent Sea Pollution from Non-Indigenous Aquatic Species

Marine species are usually transported from one area to another by the ballast water used to provide safe operation for vessels. After entering a new environment, they may cause damage to the local ecosystem, leading to the disruptions of the entire marine ecosystem, and seriously affecting not only biodiversity but also several industries such as fishing and aquaculture. Therefore, the United Nations (UN) considers the presence of non-indigenous oceanic species to be one of the top four serious threats to the global environment; and, how to effectively control the non-indigenous aquatic species has captivated the special attentions of several scientists worldwide. With the significant development in the maritime industry, strict requirements the control and management of ships’ ballast water and sediments set by The UN's International Maritime Organization (IMO) have well shaped the trend in installing ballast water treatment systems. Among them, Optimarin Ballast System is preferably used in practice. However, currently, Vietnam’s fleets use a different chemical method which is not utilized elsewhere in the world. Because it is not environmentally friendly and its effectiveness hasn’t been validated yet, this paper suggests the application of OBS in the Vietnam’s fleet in order to prevent sea pollution from non-indigenous aquatic species and minimize its associated negative impacts as well as make the Vietnam’s fleet comply with IMO requirements in protecting the global environment for sustainable development

Development of Itraconazole-Loaded Polymeric Nanoparticle Dermal Gel for Enhanced Antifungal Efficacy

Fungal infection of the skin is one of the most common dermatological diseases in the world. Gel formulations are among the most suitable dosage forms for topical use to treat cutaneous infection. Nanotechnology is a promising approach to penetrate the deeper skin layers and enhance permeability of itraconazole (ITZ) through the stratum corneum. ITZ-loaded nanoparticles (ITZ NPs) were fabricated using the evaporation emulsion method, followed by incorporation of NPs into gel using Carbopol 934 as the gel-forming excipient. The physical properties, in vitro release, ex vivo permeation studies, and antifungal activity of ITZ NP gel were characterized. ITZ NPs were almost spherical in shape with colloidal sizes in the range of 200 nm. The drug encapsulation efficiency was 98.79±1.24%. ITZ NP gel demonstrated a sustained ex vivo permeation of ITZ over 24 h through excised rat skin and a higher drug penetrating capacity than that of a gel containing ITZ-saturated suspension. The in vitro antifungal activity of the ITZ-loaded NP incorporated gel was better than that of ITZ dispersion. Incorporation of the ITZ-loaded nanosystem into gel has the potential to enhance antifungal activity through transdermal drug delivery

Detection of Shigella by a PCR Assay Targeting the ipaH Gene Suggests Increased Prevalence of Shigellosis in Nha Trang, Vietnam

Shigella spp. are exquisitely fastidious gram-negative organisms which frequently escape detection by traditional culture methods. To get a more complete understanding of the disease burden caused by Shigella in Nha Trang, Vietnam, real-time PCR was used to detect Shigella DNA. Randomly selected rectal swab specimens from 60 Shigella culture-positive patients and 500 Shigella culture-negative patients detected by population-based surveillance of patients seeking care for diarrhea were processed by real-time PCR. The target of the primer pair is the invasion plasmid antigen H gene sequence (ipaH), carried by all four Shigella species and enteroinvasive Escherichia coli. Shigella spp. could be isolated from the rectal swabs of 547 of 19,206 (3%) patients with diarrhea. IpaH was detected in 55 of 60 (93%) Shigella culture-positive specimens, whereas it was detected in 87 of 245 (36%) culture-negative patients free of dysentery (P < 0.001). The number of PCR cycles required to detect a PCR product was highest for culture-negative, nonbloody diarrheal specimens (mean number of cycles to detection, 36.6) and was lowest for children with culture-positive, bloody diarrheal specimens (mean number of cycles, 25.3) (P < 0.001). The data from real-time PCR amplification indicate that the culture-proven prevalence of Shigella among patients with diarrhea may underestimate the prevalence of Shigella infections. The clinical presentation of shigellosis may be directly related to the bacterial load

Rapid Screening and Quantitative Determination of Illegal Phosphodiesterase Type 5 Inhibitors (PDE-5i) in Herbal Dietary Supplements

Phosphodiesterase type 5 inhibitors (PDE-5i) are the first-line medication for oral erectile dysfunction, which are used according to the prescription of doctors. However, these substances have been found illegally in supplementary foods. The quality and safety of dietary supplements for enhancing male sexual performance have been questioned, raising the need for continual development of analytical methods. Liquid chromatography coupled with high-resolution mass spectrometry has become one of the most effective methods to identify and measure PDE-5i concentration. In this research, we focused on (i) developing and validating an effective screening and quantitation method for more than 53 PDE-5i in ingredients and supplementary products using LC-Q-Exactive after a simple sample extraction and (ii) assessing PDE-5i content in natural-based supplementary products available in Vietnam market. The extraction method used a small amount of organic solvent, which makes it more environmentally friendly (greener). The developed method has a limit of detection of 0.4 mg/kg, a limit of quantitation of 1.2 mg/kg, recoveries from 80 to 110%, and repeatability lower than 15%. Ninety-two herbal supplementary foods and ingredients used for enhancement of male sexual performance available in Vietnamese markets were collected. Fourteen PDE-5i including conventional and novel analogous were detected and measured in eighteen food supplements and two formulation ingredient samples

Optimization of Oligomer Chitosan/Polyvinylpyrrolidone Coating for Enhancing Antibacterial, Hemostatic Effects and Biocompatibility of Nanofibrous Wound Dressing

A synergistic multilayer membrane design is necessary to satisfy a multitude of requirements of an ideal wound dressing. In this study, trilayer dressings with asymmetric wettability, composed of electrospun polycaprolactone (PCL) base membranes coated with oligomer chitosan (COS) in various concentrations of polyvinylpyrrolidone (PVP), are fabricated for wound dressing application. The membranes are expected to synergize the hygroscopic, antibacterial, hemostatic, and biocompatible properties of PCL and COS. The wound dressing was coated by spraying the solution of 3% COS and 6% PVP on the PCL base membrane (PVP6–3) three times, which shows good interaction with biological subjects, including bacterial strains and blood components. PVP6–3 samples confirm the diameter of inhibition zones of 20.0 ± 2.5 and 17.9 ± 2.5 mm against Pseudomonas aeruginosa and Staphylococcus aureus, respectively. The membrane induces hemostasis with a blood clotting index of 74% after 5 min of contact. In the mice model, wounds treated with PVP6–3 closed 95% of the area after 10 days. Histological study determines the progression of skin regeneration with the construction of granulation tissue, new vascular systems, and hair follicles. Furthermore, the newly-growth skin shares structural resemblances to that of native tissue. This study suggests a simple approach to a multi-purpose wound dressing for clinical treatment