Large-scale fabrication of colloidal nano-sized CuCl solution with high concentration for using as fungicide for plant

Synthesis of nano-sized CuCl with Cu concentration from 4,000 to 6,000 ppm dispersed in chitosan solution (nano-sized CuCl/CTS) using CuSO4.5H2O as the precursor and NaHSO3 as the reducing agent in HCl acid medium on large scale of 1.000 kg/batch was carried out. The obtained nano-sized CuCl/CTS samples were characterized by transmission electron microscopy (TEM) and X-ray powder diffraction (XRD). Based on the obtained results, the reaction factors for fabrication of the colloidal nano-sized CuCl/CTS solution with Cu concentration of 5,000 ppm and CuCl nanoparticle size of about 7.7 nm dispersed in 1 % chitosan solution were selected for application in agriculture as a fungicide for plant protection. Keywords. Nano-sized CuCl, NaHSO3, HCl, chitosan

Determination of the relationship between Vietnam national coordinate reference system (VN-2000) and ITRS, WGS84 and PZ-90

In July 2000, Hanoi-72 reference system was replaced by the Vietnam reference system, namely as VN-2000 as an official geodetic background system in Vietnam. Ministry of Natural Resources and Environment of Vietnam has reported the transformation parameters between VN-2000 and WGS84. Nevertheless, there is a need to estimate a new transformation parameter set between VN-2000 and WGS84 because WGS84 has been updated. In addition, there is now a lack of an accurate published set of parameters for transformation from VN-2000 to not only the International Terrestrial Reference System ITRS but also PZ-90. In this study, coordinate transformation parameters between ITRS and VN-2000 are estimated through the use of a least square approach and the common points with known coordinates in both systems. These set of parameters was then deployed to determine the link between VN-2000 and WGS84 as well as PZ-90. The results denoted that the derived transformation parameters, on the basis of the results at the checkpoints, could generated station positions with the accuracy at several cm level for transformation from VN-2000 to the new realizations of ITRS, WGS84 and PZ90 and reversely. These achievements reveals that the set of parameters is great significance for many applications related to positioning in Vietnam

Effect of nanosilica/chitosan hybrid on leaf blast and blight diseases of rice in Vietnam

Nanosilica/chitosan (NSi/CTS) hybrid material was prepared using nanosilica (32.5 nm) from rice husk ash (RHA) and chitosan (CTS), and characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD). The obtained NSi/CTS was used for protection of rice leaf from blast disease (Piriculariaoryzae) and blight disease (Xanthomonasoryzae). Results indicated that foliar spraying of NSi/CTS with 100 ppm NSiand150 ppm CTS were effective against blast and blight diseases on rice (Oryza spp.). The leaf blast disease index (DI) (1.49 %) and the blight DI (1.45 %) were significantly decreased compared with control of 8.08 % and 9.29 %, respectively at 14th day after the first treatment. Thus, NSi/CTS hybrid material is promising to use for controlling plant diseases, particularly for rice

An Outbreak of Severe Infections with Community-Acquired MRSA Carrying the Panton-Valentine Leukocidin Following Vaccination

Background: Infections with community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) are emerging worldwide. We investigated an outbreak of severe CA-MRSA infections in children following out-patient vaccination. Methods and Findings: We carried out a field investigation after adverse events following immunization (AEFI) were reported. We reviewed the clinical data from all cases. S. aureus recovered from skin infections and from nasal and throat swabs were analyzed by pulse-field gel electrophoresis, multi locus sequence typing, PCR and microarray. In May 2006, nine children presented with AEFI, ranging from fatal toxic shock syndrome, necrotizing soft tissue infection, purulent abscesses, to fever with rash. All had received a vaccination injection in different health centres in one District of Ho Chi Minh City. Eight children had been vaccinated by the same health care worker (HCW). Deficiencies in vaccine quality, storage practices, or preparation and delivery were not found. Infection control practices were insufficient. CA-MRSA was cultured in four children and from nasal and throat swabs from the HCW. Strains from children and HCW were indistinguishable. All carried the Panton-Valentine leukocidine (PVL), the staphylococcal enterotoxin B gene, the gene complex for staphylococcal-cassette-chromosome mec type V, and were sequence type 59. Strain HCM3A is epidemiologically unrelated to a strain of ST59 prevalent in the USA, althoughthey belong to the same lineage. Conclusions. We describe an outbreak of infections with CA-MRSA in children, transmitted by an asymptomatic colonized HCW during immunization injection. Consistent adherence to injection practice guidelines is needed to prevent CA-MRSA transmission in both in- and outpatient settings

Influence of the Preparation Method on Some Characteristics of Alginate/Chitosan/Lovastatin Composites

This study investigates the effects of direct and indirect dispersion methods for lovastatin solid dispersion (LSD) in alginate (AG)/chitosan (CS) composites on the characteristics and properties of the AG/CS/LSD composites. The preparation method significantly influences the structure, morphology, and LSD size distribution of the composites as well as the drug release of LSD from the samples. The differences in dispersion methods for LSD lead to differences in the interaction between the components, the structure, and the control drug release of LSD. Lovastatin was released from the samples containing LSD in two stages (a fast release stage and a slow release stage), and the drug release content prepared using the indirect method is lower than that prepared using the direct method in the same buffer solution. After 32 h of testing, the released LSD content from the indirect and direct LSD dispersion methods in pH 2 and pH 7.4 buffer solutions was 87–94% and 41–61%, respectively. Drug release kinetics from the above samples in solutions with different pH values was also set up

Superspreading event of SARS-CoV-2 infection at a bar, Ho Chi Minh City, Vietnam

We report a superspreading event of severe acute respiratory syndrome coronavirus 2 infection initiated at a bar in Vietnam with evidence of symptomatic and asymptomatic transmission, based on ministry of health reports, patient interviews, and whole-genome sequence analysis. Crowds in enclosed indoor settings with poor ventilation may be considered at high risk for transmission

Clinical characteristics and laboratory values of children on admission, and outcome

†<p>Date of vaccination unless otherwise stated.</p>‡<p>HBV: Hepatitis B virus. Both received Euvax B™; MMR: Measles, Mumps, Rubella. All received Priorix™; varicella: Varilrix^R.</p>§<p>swelling at injection site beyond the expected after routine vaccination.</p>∥<p>Inotropes used were dopamine, dobutamine, noradrenaline.</p>**<p>MRSA: methicillin-resistant <i>Staphylococcus aureus</i>. NA denotes not available, a plus sign positive or present, and a minus sign negative or absent.</p>*<p>Normal ranges are as follows: hemoglobin concentration, 105–135 g/L; leukocyte count, 6 to 17.5·10⁹/L; platelet count, 150 to 400·10⁹/L; alanine aminotransferase (ALT) level, below 37 U/L; aspartate aminotransferase (AST) level, below 40 U/L; creatine phosphokinase (CK) below 200 U/L; serum creatinine concentration, 18–80 µmol/L;</p