10 research outputs found
Expansion of KPC-producing Enterobacterales in four large hospitals in Hanoi, Vietnam
Objectives
: The incidence of carbapenem resistance among nosocomial Gram-negative bacteria in Vietnam is high and increasing, including among Enterobacterales. In this study, we assessed the presence of one of the main carbapenemase genes, blaKPC, among carbapenem-resistant Enterobacterales (CRE) from four large hospitals in Hanoi, Vietnam, between 2010 and 2015, and described their key molecular characteristics.
Methods
: KPC-producing Enterobacterales were detected using conventional PCR and were further analysed using S1 nuclease pulsed-field gel electrophoresis (S1-PFGE), Southern blotting and whole-genome sequencing (WGS) for sequence typing and genetic characterisation.
Results
: blaKPC genes were detected in 122 (20.4%) of 599 CRE isolates. blaKPC-carrying plasmids were diverse in size. Klebsiella pneumoniae harbouring blaKPC genes belonged to ST15 and ST11, whereas KPC-producing Escherichia coli showed more diverse sequence types including ST3580, ST448, ST709 and ST405. Genotypic relationships supported the hypothesis of circulation of a population of ‘resident’ resistant bacteria in one hospital through the years and of transmission among these hospitals via patient transfer. WGS results revealed co-carriage of several other antimicrobial resistance genes and three different genetic contexts of blaKPC-2. Among these, the combination of ISEcp1–blaCTX-M and ISKpn27–blaKPC–ΔISKpn6 on the same plasmid is reported for the first time.
Conclusion
: We describe the dissemination of blaKPC-expressing Enterobacterales in four large hospitals in Hanoi, Vietnam, since 2010, which may have started earlier, along with their resistance patterns, sequence types, genotypic relationship, plasmid sizes and genetic context, thereby contributing to the overall picture of the antimicrobial resistance situation in Enterobacterales in Vietnam
Evaluation of awake prone positioning effectiveness in moderate to severe COVID-19
Evidence mainly from high income countries suggests that lying in the prone position may be beneficial in patients with COVID-19 even if they are not receiving invasive ventilation. Studies indicate that increased duration of prone position may be associated with improved outcomes, but achieving this requires additional staff time and resources. Our study aims to support prolonged (≥ 8hours/day) awake prone positioning in patients with moderate to severe COVID-19 disease in Vietnam. We use a specialist team to support prone positioning of patients and wearable devices to assist monitoring vital signs and prone position and an electronic data registry to capture routine clinical data
Applying Bim and Related Technologies for Maintenance and Quality Management of Construction Assets in Vietnam
Maintenance and quality management is an important task that aims to maintain the quality and performance of a construction asset under its design and requirements, to ensure the safety and the needs of its owner(s) and user(s). However, in reality, the uniqueness and complexity of construction assets along with the diversity of stakeholders involved are significant challenges that make the maintenance has not achieved the desired effect and goals, thus affect the construction assets quality. The paper studies application of Building Information Modelling (BIM), and related technologies such as Barcode, Radio Frequency Identification (RFID), Sensor, Internet of Things (IoT), Augmented Reality (AR) in many countries around the world; accompany with investigating into the readiness of these technologies in Vietnam. The study results show that all these technologies are available on the market in Vietnam. However, the technology readiness of the maintenance unit is narrow and needs to be improved. The study findings of the benefits and challenges of advanced technology adoption and the ability to implement them in Vietnam provide reliable ascertainment for researchers and construction asset managers in promoting the application of digital technologies to improve the quality and effectiveness of maintenance and quality management of construction assets in Vietna
Life Cycle Energy Consumption and Air Emissions Comparison of Alternative and Conventional Bus Fleets in Vietnam
The study (a) assesses the life cycle energy consumption and air emissions impacts of battery electric buses (e-buses) and conventional buses operated in Vietnam, and (b) compares them with those of hydrogen buses. The results indicate that e-buses and hydrogen buses are preferred options compared to conventional buses in terms of energy consumption, GHG emissions and other air quality impacts over their whole life cycle. Life cycle energy consumption of diesel buses is triple that of e-buses, and is significantly higher than that of hydrogen buses. Replacing conventional buses with e-buses can reduce energy consumption by 50%. For GHG emissions and air quality impacts, the adoption of electric and hydrogen mobility in replacement of conventional buses will reduce GHG emissions by 39%, and other impacts related to air quality by 13% to 90%
Optimization of Microwave-Assisted Extraction Process of Callicarpa candicans (Burm. f.) Hochr Essential Oil and Its Inhibitory Properties against Some Bacteria and Cancer Cell Lines
Callicarpa candicans (Burm. f.) Hochr. (Callicarpa cana L.) is a medicinal plant that is distributed mainly in the tropics and subtropics of Asia and finds a wide range of uses in traditional medicine. In this study, we attempted and optimized the microwave-assisted hydro-distillation (MAHD) process to obtain essential oil from the leaves of C. candicans. In addition, the obtained oil was analyzed for volatile composition by gas chromatography–mass spectrometry (GC-MS) and assayed for bioactivity against several bacteria and cancer cell lines. To optimize the extraction process, response surface methodology (RSM) in combination with central composite design (CCD) was adopted. Experimental design and optimization were carried out with respect to three experimental factors including the ratio of water to raw material, extraction time, and microwave power. The optimal extraction conditions were obtained as follows: water to raw material ratio of 6/1 (v/w), extraction time 42 min, and microwave power 440 W. Composition determination of the obtained C. candicans essential oil indicated the presence of predominant components including caryophyllene <b-> (10.45%), cadinene <d-> (10.28%), gurjunene <a-> (8.95%), muurolene <g-> (8.92%), selinene <a-> (7.06%), selinene <b-> (5.59%), and copaene <a-> (5.40%). In comparison with the essential oils obtained via traditional hydro-distillation method, the essential oil extracted by MAHD exhibited superior anti-proliferative activity on all tested cancer cell lines. Current results imply that the MAHD is capable of recovering biologically-active natural products of greater quantity than that recovered by the conventional distillation
Insights into Molten Salts Induced Structural Defects in Graphitic Carbon Nitrides for Piezo-Photocatalysis with Multiple H2O2 Production Channels
Recently, the production of hydrogen peroxide (H2O2) from water (H2O) and oxygen (O2) in the presence of graphitic carbon nitrides (g-C3N4) via a piezo-photocatalytic process has considerably ignited global interest in achieving sustainability. To fabricate porous g-C3N4, soft templates are frequently employed, leading to structural modifications originating from heteroatoms. However, many recent reports have ignored the roles of trace quantity of heteroatoms. Hence, to understand the impacts of the mentioned factors, we fabricated g-C3N4 containing oxygen and halogen atoms in the structures for piezo-photosynthesis of H2O2. Based on our analyzed results, oxygen atoms might be inserted into g-C3N4 in-plane structures, while halogen atoms tend to become intercalated between g-C3N4 layers. Furthermore, the presence of ammonium molten salts during the synthesis alters the concentration of mono and cluster vacancies of carbon and nitrogen in the materials. These defective contributions would meaningfully accelerate catalytic performance by providing trapping states. From the mechanistic view, different reduction and oxidation channels would play a pivotal role in generating H2O2. Thus, this study highlights the importance of modulating in-plane and out-of-plane structures of g-C3N4, benefiting catalytic properties under simultaneous irradiation
Promoted Hydrogen Peroxide Production from Pure Water on g-C3N4 with Nitrogen Defects Constructed through Solvent-Precursor Interactions: Exploring A Complex Story in Piezo-Photocatalysis
Hydrogen peroxide (H2O2) production via oxygen (O2) reduction reaction (ORR) in pure water (H2O) through graphitic carbon nitrides (g-C3N4)-based piezo-photocatalysts is an exciting approach in many current studies. However, the low Lewis-acid properties of g-C3N4 limited the catalytic performance because of the low O2 adsorption efficacy. To overcome this challenge, we utilized the interaction of g-C3N4 precursors with various solvents to synthesize g-C3N4, possessing multiple nitrogen-vacant species via thermal shocking polymerization. Our results suggest that the lack of nitrogen in g-C3N4 and the incident introduction of oxygen-functional groups enhance the Lewis acid-base interactions and polarize the g-C3N4 lattices, leading to the enormous enhancement, roughly 7 times from the optimal samples compared to pristine g-C3N4 in pure water via piezo-photocatalysis. Meanwhile, we also observed the correlation between the charge separation kinetic and the crystalline degree of the synthesized materials, which can elucidate how the nitrogen defects impacted the catalytic outcomes. Furthermore, the catalytic mechanisms were thoroughly studied, with the formation of H2O2 proceeding via radical and water oxidation pathways, in which the roles of light and ultrasound were carefully investigated. Thus, our findings not only reinforce the potential view of metal-free photocatalysts, accelerating the understanding of g-C3N4 working principles to generate H2O2 based on the oxygen reduction and water oxidation reactions, but also propose a facile one-step way for fabricating highly efficient and scalable photocatalysts to produce H2O2 without using sacrificial agents, pushing the practical application of in-situ solar H2O2 toward real-world scenarios
Multimodal analysis of methylomics and fragmentomics in plasma cell-free DNA for multi-cancer early detection and localization
Despite their promise, circulating tumor DNA (ctDNA)-based assays for multi-cancer early detection face challenges in test performance, due mostly to the limited abundance of ctDNA and its inherent variability. To address these challenges, published assays to date demanded a very high-depth sequencing, resulting in an elevated price of test. Herein, we developed a multimodal assay called SPOT-MAS (screening for the presence of tumor by methylation and size) to simultaneously profile methylomics, fragmentomics, copy number, and end motifs in a single workflow using targeted and shallow genome-wide sequencing (~0.55×) of cell-free DNA. We applied SPOT-MAS to 738 non-metastatic patients with breast, colorectal, gastric, lung, and liver cancer, and 1550 healthy controls. We then employed machine learning to extract multiple cancer and tissue-specific signatures for detecting and locating cancer. SPOT-MAS successfully detected the five cancer types with a sensitivity of 72.4% at 97.0% specificity. The sensitivities for detecting early-stage cancers were 73.9% and 62.3% for stages I and II, respectively, increasing to 88.3% for non-metastatic stage IIIA. For tumor-of-origin, our assay achieved an accuracy of 0.7. Our study demonstrates comparable performance to other ctDNA-based assays while requiring significantly lower sequencing depth, making it economically feasible for population-wide screening