Synthesis of para-menthane 3,8 - diol from Eucalyptus citriodora essential oil for application in mosquito repellent products

To repel mosquitoes, there have been many highly effective chemical repellent products, but they carry the potential risk of being unsafe for humans and harmful to the environment. Insect repellent products derived from natural sources that are safe for humans and environmentally friendly are becoming increasingly popular. PMD is a broad-spectrum and effective insect repellent but is present in small amounts in the Eucalyptus citriodora essential oil (EO). In this study, we investigated and evaluated the conditions for synthesizing PMD from EO raw materials in an acidic environment to achieve the highest synthesis efficiency of 76.3%, and the PMD product was 96.4% pure after being converted for 5 hours at 50°C in a 0.25% H2SO4 solution. Additionally, the study also separated the two cis and trans isomers of PMD by column chromatography and determined their structures using infrared spectroscopy (IR) and nuclear magnetic resonance (NMR)

The clinical features of osteogenesis imperfecta in Vietnam

Purpose Osteogenesis imperfecta (OI) has not been studied in a Vietnamese population before. The aim of this study was to systematically collect epidemiological information, investigate clinical features and create a clinical database of OI patients in Vietnam for future research and treatment strategy development. Method Participants underwent clinical and physical examinations; also medical records were reviewed. Genealogical information was collected and family members’ phenotypical manifestations recorded. Cases were classified according to the Sillence classification. Results In total, 146 OI patients from 120 families were studied: 46 with OI Type I, 46 with Type III and 54 with Type IV. Almost patients had skeletal deformations. One hundred and forty-two had a history of fractures, 117 blue sclera, 89 dentinogenesis imperfecta and 26 hearing loss. The total number of fractures was 1,932. Thirty-four patients had intra-uterine fractures and nine had perinatal fractures. Surgery was performed 163 times in 58 patients; 100 osteosyntheses and 63 osteotomies. Bisphosphonate treatment was used in 37 patients. The number of affected individuals and predominance of severe forms of OI indicate that the disease is under diagnosed in Vietnam, especially in cases without a family history or with mild form of OI. Deformities appeared in all patients with different severity and localisation, affecting mostly the lower limbs. OI medical and surgical treatment rates are low and in most cases surgery was performed due to fractures. Conclusions Compared to previous studies, our results indicate a lower OI prevalence and greater severity of symptoms in the Vietnamese population when compared with other areas. Further investigation, improved diagnosis and treatment are needed to increase the patients’ quality of life

A novel ciprofloxacin-resistant subclade of H58 Salmonella Typhi is associated with fluoroquinolone treatment failure.

The interplay between bacterial antimicrobial susceptibility, phylogenetics and patient outcome is poorly understood. During a typhoid clinical treatment trial in Nepal, we observed several treatment failures and isolated highly fluoroquinolone-resistant Salmonella Typhi (S. Typhi). Seventy-eight S. Typhi isolates were genome sequenced and clinical observations, treatment failures and fever clearance times (FCTs) were stratified by lineage. Most fluoroquinolone-resistant S. Typhi belonged to a specific H58 subclade. Treatment failure with S. Typhi-H58 was significantly less frequent with ceftriaxone (3/31; 9.7%) than gatifloxacin (15/34; 44.1%)(Hazard Ratio 0.19, p=0.002). Further, for gatifloxacin-treated patients, those infected with fluoroquinolone-resistant organisms had significantly higher median FCTs (8.2 days) than those infected with susceptible (2.96) or intermediately resistant organisms (4.01)(pS. Typhi clade internationally, but there are no data regarding disease outcome with this organism. We report an emergent new subclade of S. Typhi-H58 that is associated with fluoroquinolone treatment failure

Internal Micro-electrolysis Using Fe/C Material for Pre-Treatment of Concentrated Coking Wastewater

Untreated coking effluent presents a great challenge for sustainable development of the steel industry and environment preservation. In this study, an internal micro-electrolysis method using Fe/C materials was employed for pretreatment of real coking wastewater with high mass concentration. The Fe/C materials were prepared by Fe powder and graphite powder; and the characteristics of surface morphology, structure, composition of the synthesized materials were examined by Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Energy Dispersive X-ray Spectroscopy (EDS). The effects of factors namely dosage of Fe/C material, treatment time, initial pH and temperature were investigated via chemical oxygen demand (COD) and phenol removal efficiencies. Optimal treatment efficiency was attained at pH of 4, Fe/C dosage of 40 g/L, treatment time of 360 minutes and temperature of 25°C. After the internal electrolysis process, the values of COD, BOD5, and phenol of the wastewater were 6500, 4850 and 0.1 mg/L, respectively

Synergistic Influences of Stearic Acid Coating and Recycled PET Microfibers on the Enhanced Properties of Composite Materials

International audienceThis study aims to produce novel composite artificial marble materials by bulk molding compound processes, and improve their thermal and mechanical properties. We employed stearic acid as an efficient surface modifying agent for CaCO3 particles, and for the first time, a pretreated, recycled, polyethylene terephthalate (PET) fibers mat is used to reinforce the artificial marble materials. The innovative aspects of the study are the surface treatment of CaCO3 particles by stearic acid. Stearic acid forms a monolayer shell, coating the CaCO3 particles, which enhances the compatibility between the CaCO3 particles and the matrix of the composite. The morphology of the composites, observed by scanning electron microscopy, revealed that the CaCO3 phase was homogeneously dispersed in the epoxy matrix under the support of stearic acid. A single layer of a recycled PET fibers mat was pretreated and designed in the core of the composite. As expected, these results indicated that the fibers could enhance flexural properties, and impact strength along with thermal stability for the composites. This combination of a pretreated, recycled, PET fibers mat and epoxy/CaCO3-stearic acid could produce novel artificial marble materials for construction applications able to meet environmental requirements

Co2+ substituted for Bi3+ in BiVO4 and its enhanced photocatalytic activity under visible LED light irradiation

We investigated the fabrication of Co-doped BiVO4 (Bi1-xCoxVO4+δ, 0.05 < x < 0.5) by the substitution of Co ions for Bi sites in BiVO4. The X-ray diffraction (XRD), Raman, and X-ray photoelectron spectroscopy (XPS) results indicated that the substitution of Co2+ ions for Bi3+ sites in BiVO4 was successful, although a change in the crystal phase of BiVO4 did not occur. UV-vis DRS and PL results suggested that the Co-incorporation could slightly improve the visible light absorption of BiVO4 and induce the separation of photoinduced electron-hole pairs; therefore, a significant enhancement of photocatalytic performance was achieved. The Bi0.8Co0.2VO4+δ sample showed superior photocatalytic activity in comparison with other samples, achieving 96.78% methylene blue (MB) removal within 180 min. In addition, the proposed mechanism of improved photocatalytic activities and the stability of the catalyst were also investigated.This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 104.05-2017.315

Determination of optimal loading and maintenance doses for continuous infusion of vancomycin in critically ill patients: Population pharmacokinetic modelling and simulations for improved dosing schemes

OBJECTIVES: Despite extensive clinical use, limited data are available on optimal loading and maintenance doses of vancomycin in critically ill patients. This study aimed to develop a rational approach for optimised dosage of vancomycin given in a continuous infusion in critically ill patients. METHODS: Vancomycin pharmacokinetic (PK) data (total serum concentrations) were obtained from 55 intensive care unit (ICU) patients (Bach Mai Hospital, Hanoi, Vietnam) receiving a 20 mg/kg loading dose followed by continuous infusion stratified by creatinine clearance (CLCr). Population PK modelling and Monte Carlo simulations were performed using a nonlinear mixed-effects modelling (NONMEM) program for a target of 20-30 mg/L to optimise efficacy and minimise nephrotoxicity. RESULTS: A two-compartment model with first-order elimination best fitted the PK data with central and peripheral volumes of distribution of 1.01 and 2.39 L/kg, respectively (allometric scaling to a 70 kg standard subject). The population total clearance of 3.63 L/h was only explained by renal function in the covariate and final model. The simulations showed that a 25-mg/kg loading dose infused over 90 minutes was optimal to reach the target range. The optimal maintenance dose for low renal function (CLCr 130 mL/min) the dose should be up to 3500 mg/day or even 4500 mg/day to achieve adequate exposure. These simulated maintenance doses were larger than previously proposed for non-ICU patients. CONCLUSION: Large loading and maintenance doses of vancomycin are generally needed in critically ill patients. Because of high interindividual variability in vancomycin PK, drug monitoring may still be necessary

BƯỚC ĐẦU KHẢO SÁT ĐỘT BIẾN GEN BRCA1 VÀ BRCA2 T RONG QUẦN THỂ UNG THƯ BIỂU MÔ BUỒNG TRỨNG NGƯỜI VIỆT NAM BẰNG KỸ THUẬT GIẢI TRÌNH TỰ THẾ HỆ MỚI

BRCA1 and BRCA2 are two important tumor suppressor genes. The germline and somatic mutations of these two genes in ovarian carcinomas are sensitive for treatment with ADP-ribose polymerase enzyme inhibitor (PARPi). Recently, several PARPi drugs, such as Olaparib and Rucaparib, have been approved for ovarian cancer with BRCA1/2 germline mutations by Food and Drug Administration (FDA), and for both germline and somatic mutations by European Medicines Agency (EMA). However, there have no been reliable data about the prevalence of mutations of these two genes in ovarian carcinomas population for treatment in Vietnam so far. Therefore, we studied the prevalence of the BRCA1/2 germline and somatic mutations among ovarian carcinomas patients in the Vietnamese population. In this study, we sequenced these two genes by using Ion Torrent PGM. The subjects of the study are 11 formalin-fixed paraffin-embedded tumor (FFPE) samples from 11 patients with ovarian carcinomas obtained from Tu Du Hospital of Obstetrics and Gynecology (Vietnam). Multiplex PCR then was performed on the DNA samples and two controls containing known mutations by using Oncomine BRCA Research Assay. Of the sequenced 11 samples, a pathogenic mutation (1/11 patient, 9.1%) detected on the BRCA1 gene was a nonsense point mutation causing stop codon at the position of amino acid 1772. Consequently, our sequencing workflow shows the success in identifying and investigating the prevalence of BRCA1/2 mutation in a small group of ovarian carcinomas with FFPE tumor samples.BRCA1 và BRCA2 là hai gen ức chế khối u quan trọng. Việc đột biến hai gen này ở bệnh nhân ung thư biểu mô buồng trứng dòng mầm và dòng sinh dưỡng thì đáp ứng tốt hơn với thuốc ức chế enzyme poly(ADP-ribose) polymerase inhibitor (PARPi). Gần đây, một vài thuốc PARPi, như Olaparib và Rucaparib, đã được chấp thuận dùng cho bệnh nhân ung thư buồng trứng với đột biến dòng mầm BRCA1/2 bởi Food and Drug Administration (FDA) và với đột biến dòng mầm và dòng sinh dưỡng đối với European Medicines Agency (EMA). Tuy nhiên, hiện nay Việt Nam chưa có dữ liệu nào đáng tin cậy về tình trạng đột biến hai gen này trong quần thể bệnh nhân ung thư biểu mô buồng trứng nhằm hỗ trợ cho điều trị. Do đó, chúng tôi tiến hành giải trình tự nhằm khảo sát đột biến hai gen BRCA1/2 dòng mầm và dòng sinh dưỡng ở bệnh nhân ung thư biểu mô buồng trứng người Việt Nam. Trong nghiên cứu này, chúng tôi tiến hành giải trình tự hai gen này bằng Ion Torrent PGM. Đối tượng nghiên cứu là 11 mẫu mô vùi nến được thu nhận từ Bệnh viện Từ Dũ của 11 bệnh nhân ung thư biểu mô buồng trứng. DNA từ các mẫu này và 2 mẫu đối chứng đã biết thông tin đột biến được tiến hành multilplex PCR với kit Oncomine BRCA Research Assay. Trong mười một mẫu được giải trình tự, một đột biến gây bệnh (1/11 bệnh nhân; 9,1%) đã được phát hiện trên gen BRCA1, là đột biến điểm đưa codon stop vào trình tự protein tại vị trí axit amin 1772. Tóm lại, quy trình giải trình tự của chúng tôi thành công trong việc xác định và khảo sát tỉ lệ đột biến BRCA1/2 trong một nhóm nhỏ bệnh nhân ung thư biểu mô buồng trứng với mẫu sinh phẩm là mô vùi nến

Exploration de la biodiversité végétale et microbienne pour la qualité et la sureté des aliments

International audienceLa qualité et sureté des aliments jouent un rôle important au Vietnam et dans la région de l'Asie du Sud Est. Dans son programme intégral, l'ASEAN met la sureté des aliments parmi des 12 priorités. Plusieurs travaux ont été focalises sur l'exploration de la biodiversité et des innovations technologiques en Asie du Sud Est afin d'améliorer la qualité et de gérer la sureté des aliments. C'est pour ces raisons, nous avons crée un réseau régional avec les soutiens des partenaires francophones et non-francophones en se basant sur les besoins de la région, l'expertise des partenaires et les coopérations étroites. Ce réseau est composé des 10 partenaires dynamiques et actifs provenant de la France, la Thaïlande, la Chine, et le Vietnam qui ont fait partie du Pre-projet de Coopération Scientifique Inter-universitaire PCSI http://pcsi2013.hust.edu.vn) de l'Agence Universitaire de la Francophonie (AUF) et le Laboratoire International Associe UB/AgroSup Dijon/HUST "Tropical Bioresources & Biotechnology"(www.umr-pam.fr/relation-internationale/tropical-bioresources-biotechnology.html). Notre présentation partagera nos expériences pour monter ce réseau a travers les régions et avec les partenaires francophones, souligner nos activités de recherche multidisciplinaires ainsi que notre point de vue vis-a-vis les interactions Nord-Sud et Sud-Sud. Nous allons aborder nos résultats issus de différents projets associes a ce réseau donc tels que la biodiversité des actinomycètes associes aux plantes médicinales, les bactéries lactiques dans les produits traditionnels fermentes du Vietnam et la valorisation de l'agriculture (riz, manioc) et leurs sous-produits par voies biologiques. (Résumé d'auteur