17 research outputs found

    Assessment of Drivers of Antimicrobial Usage in Poultry Farms in the Mekong Delta of Vietnam: A Combined Participatory Epidemiology and Q-Sorting Approach

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    In the Mekong Delta of Vietnam, poultry farmers use high amounts of antimicrobials, but little is known about the drivers that influence this usage. We aimed to identify these drivers using a novel approach that combined participatory epidemiology (PE) and Q-sorting (a methodology that allows the analysis of the subjectivity of individuals facing a common phenomenon). A total of 26 semi-structured collective interviews were conducted with 125 farmers representative of the most common farming systems in the area (chickens, meat ducks, and mobile grazing ducks), as well as with 73 farmers' advisors [veterinarians, veterinary drug shop owners, and government veterinarians/commune animal health workers (CAHWs)] in five districts of Dong Thap province (Mekong Delta). Through these interviews, 46 statements related to the antimicrobials' perceived reliability, costs, and impact on flock health were created. These statements were then investigated on 54 individuals (28 farmers and 26 farmers' advisors) using Q-sorting interviews. Farmers generally indicated a higher propensity for antimicrobial usage (AMU) should their flocks encounter bacterial infections (75.0–78.6%) compared with viral infections (8.3–66.7%). The most trusted sources of advice to farmers were, in decreasing order: government veterinarian/CAHWs, their own knowledge/experience, veterinary drug shop owners, and sales persons from pharmaceutical and feed companies. The highest peak of AMU took place in the early phase of the production cycle. Farmers and their advisors showed considerable heterogeneity of attitudes with regards to AMU, with, respectively, four and three discourses representing their views on AMU. Overall, farmers regarded the cost of AMU cheaper than other disease management practices implemented on their farms. However, they also believed that even though these measures were more expensive, they would also lead to more effective disease prevention. A key recommendation from this finding would be for the veterinary authorities to implement long-term sustainable training programs aiming at reducing farmers' reliance on antimicrobials

    Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

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    Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

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

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    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&ndash;3) three times, which shows good interaction with biological subjects, including bacterial strains and blood components. PVP6&ndash;3 samples confirm the diameter of inhibition zones of 20.0 &plusmn; 2.5 and 17.9 &plusmn; 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&ndash;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

    Moisture-Assisted Hydroboration of Nitriles and Conversion Thereof to N-Heterocyles and N-Containing Derivatives

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    The recent revelation of hidden-borane catalysis has revolutionized the field of catalytic hydroboration in organic synthesis. Many nucleophilic reaction promoters, previously believed to be the catalysts, in fact primarily facilitated the formation of borane (BH3), which subsequently acted as the true catalyst. This revelation prompted us to explore the untapped potential of these unexpected transformations, with a view to simplify hydroboration using more cost-effective and environmentally friendly nucleophilic pre-catalysts. Via computational studies, we were able to identify that water can actually undertake that role. Herein, we report a study on simple hydroboration of nitriles, a notorious-ly challenging yet synthetically valuable class of substrates, using nothing more than moisture as an activating agent. This moisture-assisted nitrile hydroboration process can seamlessly integrate with a range of downstream transfor-mations in a one-pot fashion to produce valuable N-containing products such as symmetrical imines, thioureas and bis(alcohol)amines as well as N-heterocyclic derivatives such as pyrroles, pyridines, pyridinium salts, 2-iminothiazolines and carbazoles

    Moisture-Assisted Hydroboration of Nitriles and Conversion Thereof to <i>N</i>‑Heterocyles and <i>N</i>‑Containing Derivatives

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    The recent revelation of hidden-borane catalysis has revolutionized the field of catalytic hydroboration in organic synthesis. Many nucleophilic reaction promoters, previously believed to be the catalysts, in fact primarily facilitated the formation of borane (BH3), which subsequently acted as the true catalyst. This revelation prompted us to explore the untapped potential of these unexpected transformations, with a view to simplify hydroboration using more cost-effective and environmentally friendly nucleophilic precatalysts. Via computational studies, we were able to identify that water can actually undertake that role. Herein, we report a study on the simple hydroboration of nitriles, a notoriously challenging yet synthetically valuable class of substrates, using nothing more than moisture as an activating agent. This moisture-assisted nitrile hydroboration process can seamlessly integrate with a range of downstream transformations in a one-pot fashion to produce valuable N-containing products such as symmetrical imines, thioureas, and bis(alcohol)amines as well as N-heterocycles such as pyrroles, pyridines, pyridinium salts, 2-iminothiazolines, and carbazoles

    Organosuperbase Catalyzed 1,1-Diboration of Alkynes

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    1,1-diboryl alkenes are versatile building blocks in organic synthesis and medicinal chemistry. There have been only a small number of established methods to prepare this class of compounds and most of them used transition metal catalysts, which are undesirable in the preparation of bioactive compounds. Herein, we report an unprecedented application of P1-tBu as an organocatalyst to promote 1,1-diboration reactions of unactivated aromatic as well as electron-deficient terminal alkynes. The strong basicity of this phosphazene enables the activation of reaction substrates while its steric bulk allows for high regio- and stereo-selectivity to be obtained. A combination of experimental and computational studies suggests interesting mechanistic insights for these phosphazene-catalyzed diboration reaction, which are also discussed in detail

    Assessment of drivers of antimicrobial usage in poultry farms in the Mekong delta of vietnam: A combined participatory epidemiology and Q-sorting approach

    No full text
    International audienceIn the Mekong Delta of Vietnam, poultry farmers use high amounts of antimicrobials, but little is known about the drivers that influence this usage. We aimed to identify these drivers using a novel approach that combined participatory epidemiology (PE) and Q-sorting (a methodology that allows the analysis of the subjectivity of individuals facing a common phenomenon). A total of 26 semi-structured collective interviews were conducted with 125 farmers representative of the most common farming systems in the area (chickens, meat ducks, and mobile grazing ducks), as well as with 73 farmers' advisors [veterinarians, veterinary drug shop owners, and government veterinarians/commune animal health workers (CAHWs)] in five districts of Dong Thap province (Mekong Delta). Through these interviews, 46 statements related to the antimicrobials' perceived reliability, costs, and impact on flock health were created. These statements were then investigated on 54 individuals (28 farmers and 26 farmers' advisors) using Q-sorting interviews. Farmers generally indicated a higher propensity for antimicrobial usage (AMU) should their flocks encounter bacterial infections (75.0-78.6%) compared with viral infections (8.3-66.7%). The most trusted sources of advice to farmers were, in decreasing order: government veterinarian/CAHWs, their own knowledge/experience, veterinary drug shop owners, and sales persons from pharmaceutical and feed companies. The highest peak of AMU took place in the early phase of the production cycle. Farmers and their advisors showed considerable heterogeneity of attitudes with regards to AMU, with, respectively, four and three discourses representing their views on AMU. Overall, farmers regarded the cost of AMU cheaper than other disease management practices implemented on their farms. However, they also believed that even though these measures were more expensive, they would also lead to more effective disease prevention. A key recommendation from this finding would be for the veterinary authorities to implement long-term sustainable training programs aiming at reducing farmers' reliance on antimicrobials

    Characterizations and Antibacterial Efficacy of Chitosan Oligomers Synthesized by Microwave-Assisted Hydrogen Peroxide Oxidative Depolymerization Method for Infectious Wound Applications

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    The use of naturally occurring materials with antibacterial properties has gained a great interest in infected wound management. Despite being an abundant resource in Vietnam, chitosan and its derivatives have not yet been intensively explored for their potential in such application. Here, we utilized a local chitosan source to synthesize chitosan oligomers (OCS) using hydrogen peroxide (H2O2) oxidation under the microwave irradiation method. The effects of H2O2 concentration on the physicochemical properties of OCS were investigated through molecular weight, degree of deacetylation, and heavy metal contamination for optimization of OCS formulation. Then, the antibacterial inhibition was examined; the minimum inhibitory concentration and minimum bactericidal concentration (MIC and MBC) of OCS-based materials were determined against common skin-inhabitant pathogens. The results show that the local Vietnamese chitosan and its derivative OCS possessed high-yield purification while the molecular weight of OCS was inversely proportional and proportional to the concentration of H2O2, respectively. Further, the MIC and MBC of OCS ranged from 3.75 to less than 15 mg/mL and 7.5–15 mg/mL, respectively. Thus, OCS-based materials induce excellent antimicrobial properties and can be attractive for wound dressings and require further investigation

    Fabrication of silver nanoparticle-containing electrospun polycaprolactone membrane coated with chitosan oligosaccharides for skin wound care

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    An ideal wound dressing should have several qualities to protect the wound from infection and other adverse factors. This study aimed to fabricate a wound care membrane combining the two well-known bioactive agents silver nanoparticles (AgNPs) and chitosan oligosaccharides (COS). In specific, this multilayer membrane (PCL-Ag/POX/COS) consisted of (1) the electrospun basement layer of poly(ε-caprolactone) (PCL) and AgNPs; (2) the intermediate amphiphilic layer of PCL and poloxamer 407 (POX); and (3) the coating layer of COS and poly(N-vinyl pyrrolidone) (PVP). Several characterisation tests showed that the membrane was successfully coated with COS and owned suitable characteristics as a wound dressing, including proper tensile strength (more significant than the typical value of the skin), the hydrophilic and fluid-absorbable innermost surface, the waterproof outermost basement, vapour permeability, rapid COS release, and gradual AgNP release. In vitro experiments proved its haemostatic effect and antibacterial activities. Though its 100% extract solution reduced in vitro fibroblast viability, through the skin-defected mouse model experiment, PCL-Ag/POX/COS was compatible with the wound tissue and exhibited several positive effects on wound healing. In conclusion, PCL-Ag/POX/COS was proven for its potential for wound care, but it needs further investigations to allow translation from bench to bedside
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