The relationship between age and seroprevalence can be used to estimate the annual attack rate of an infectious disease. For pathogens with multiple serologically distinct strains, there is a need to ...describe composite exposure to an antigenically variable group of pathogens. In this study, we assay 24,402 general-population serum samples, collected in Vietnam between 2009 to 2015, for antibodies to eleven human influenza A strains. We report that a principal components decomposition of antibody titer data gives the first principal component as an appropriate surrogate for seroprevalence; this results in annual attack rate estimates of 25.6% (95% CI: 24.1% - 27.1%) for subtype H3 and 16.0% (95% CI: 14.7% - 17.3%) for subtype H1. The remaining principal components separate the strains by serological similarity and associate birth cohorts with their particular influenza histories. Our work shows that dimensionality reduction can be used on human antibody profiles to construct an age-seroprevalence relationship for antigenically variable pathogens.
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Berberine (BBR) is a plant-origin quaternary isoquinoline alkaloid presenting exogenous cholesterol lowering and anti-hyperlipidemia therapeutic effects. The aim of this study was to ...design and generate BBR-loaded proliposomes (PLs) as solid templates for high-dose liposomes and consequently, to enhance the oral bioavailability and therapeutic effect of BBR. An air-suspension coating (layering) method was used for generating BBR-loaded PLs. The size, distribution size, morphology, and entrapment efficiency (EE) of the final reconstituted liposomes were assessed. The oral bioavailability and endogenous cholesterol lowering effects of BBR loaded in liposomes were investigated in rats and mice, respectively. The BBR-loaded PLs showed a smooth BBR-embedded film around micron-scale carrier particles (mannitol). The reconstituted BBR-loaded liposomes had a nano-scale average size (116.6 ± 5.8 nm), narrow size distribution (polydispersity index, PDI 0.269 ± 0.038), and high EE (87.8 ± 1.0%). The oral bioavailability of reconstituted BBR-loaded liposomes at a dose of 100 mg/kg in rats was increased even 628% compared to that obtained with pure BBR (according to 90% confidence interval). The BBR-loaded liposomes at the daily oral dose 100 mg/kg in P-407- reduced total cholesterol, triglycerides and low-density lipoprotein cholesterol (LDL-C) in hyperlipidemic mice by 15.8%, 38.2%, and 57.0%, respectively.
Sepsis is the most common cause of in-hospital deaths, especially from low-income and lower-middle-income countries (LMICs). This study aimed to investigate the mortality rate and associated factors ...from sepsis in intensive care units (ICUs) in an LMIC. We did a multicenter cross-sectional study of septic patients presenting to 15 adult ICUs throughout Vietnam on the 4 days representing the different seasons of 2019. Of 252 patients, 40.1% died in hospital and 33.3% died in ICU. ICUs with accredited training programs (odds ratio, OR: 0.309; 95% confidence interval, CI 0.122-0.783) and completion of the 3-h sepsis bundle (OR: 0.294; 95% CI 0.083-1.048) were associated with decreased hospital mortality. ICUs with intensivist-to-patient ratio of 1:6 to 8 (OR: 4.533; 95% CI 1.621-12.677), mechanical ventilation (OR: 3.890; 95% CI 1.445-10.474) and renal replacement therapy (OR: 2.816; 95% CI 1.318-6.016) were associated with increased ICU mortality, in contrast to non-surgical source control (OR: 0.292; 95% CI 0.126-0.678) which was associated with decreased ICU mortality. Improvements are needed in the management of sepsis in Vietnam such as increasing resources in critical care settings, making accredited training programs more available, improving compliance with sepsis bundles of care, and treating underlying illness and shock optimally in septic patients.
The current study reports the preparation and investigation of several Pt-based anode catalysts loaded on reduced graphene oxide (rGO) as electrocatalysts in both acid and alkaline media for ethanol ...electrooxidation. The synthesized catalysts are evaluated by the method of XRD, Raman spectroscopy, XPS and TEM. Electrocatalytic properties of these catalysts for ethanol oxidation were investigated by cyclic voltammetry and chronoamperometry. It was found that the as-prepared nanocatalysts doped by metals and oxide metals showed the improvement of catalytic performance compared to Pt-only supported on graphene catalyst. The results indicated that the presence of Al favoured Pt nanoparticles dispersing on the surface of rGO sheets. Indeed, the PAG catalyst exhibits the highest mass activity for the ethanol oxidation of 1194 mA mg−1Pt in acid medium and 3691 mA mg−1Pt in alkaline medium. In addition, the PAG catalyst also shows good antipoisoning ability for ethanol electrooxidation in both media. This catalyst could be a potential catalyst for direct ethanol fuel cell (DEFC).
•Graphene-supported Pt-based multimetallic catalysts were successfully synthesized.•Electrocatalytic performances of catalysts were examined in acid and alkaline media.•Catalyst containing Pt and Al shows the best electroactivity for ethanol electrooxidation.•Promotion effect of catalysts should be attributed to the presence of AlOOH.•Durability of PtAl-based catalyst was evaluated in both media.
In this work, Pt-SiO2/graphene nanocomposites have been synthesized under solvothermal conditions and investigated as electrocatalysts for methanol oxidation. Structure and morphology of these ...catalysts are characterized by transmission electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and nitrogen adsorption/desorption studies. The Pt and SiO2 contents of these nanocomposites are determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Their electrocatalytic properties are investigated by cyclic voltammetry, chronoamperometry, chronopotentiometry and electrochemical impendence spectroscopy. The as-prepared nanocomposites show the improved catalytic performance, better stability and good antiposoining ability compared with Pt supported on graphene catalyst. Particularly, the catalyst containing 9.24% of SiO2 exhibits the best electrocatalytic performance for methanol oxidation with mass activity of 1047mAmg−1.
Although it is unclear how Zn
2+
cooperates with Cu
2+
in synergistic antibacterial activity, a 1:10 ratio of Cu
2+
/Zn
2+
atoms and ethylenediaminetetra-acetic acid and urea ligands can be used to ...form a chelation complex containing Cu
2+
and Zn
2+
. This study investigated the effects of the combination of Cu
2+
and Zn
2+
in chelation with EDTA and urea. The results were compared with the outcomes of either copper or zinc alone against gram-negative
Escherichia coli (E. coli
) and gram-positive
Staphylococcus aureus (S. aureus
) bacteria. The antibacterial activity was determined through MICs, disc diffusion method, and bacterial cell growth curves. In addition, bacterial destruction by this chelation complex has been observed through SEM images. The presence of copper ion and zinc ion inside the bacterial cells has been proved through EDS measurements. The obtained results allowed us to draw conclusions that the use of both Cu
2+
and Zn
2+
in a chelation complex with EDTA and urea enhances the antimicrobial activity against these bacteria. The bacterial inhibition of this complex was stronger than that of Cu
2+
alone chelated with EDTA or CuSO
4
solution by approximately 100-fold for
S. aureus
and 20-fold for
E. coli
.
Shigella sonnei is a human-adapted pathogen that is emerging globally as the dominant agent of bacterial dysentery. To investigate local establishment, we sequenced the genomes of 263 Vietnamese S. ...sonnei isolated over 15 y. Our data show that S. sonnei was introduced into Vietnam in the 1980s and has undergone localized clonal expansion, punctuated by genomic fixation events through periodic selective sweeps. We uncover geographical spread, spatially restricted frontier populations, and convergent evolution through local gene pool sampling. This work provides a unique, high-resolution insight into the microevolution of a pioneering human pathogen during its establishment in a new host population.
Titanium dioxide (TiO
2
) nanotubes were synthesized via one-step dynamic hydrothermal process from commercial TiO
2
powder. The effects of NaOH concentration, reaction time, reaction temperature, ...stirring process and washing on the morphology, and the exchange ions of the nanotubes were investigated. The morphology of the nanotubes was characterized in detail with transmission electron microscopy and scanning electron microscope. In the dynamic hydrothermal process, stirring can reduce the reaction time of transformation from particles to nanotubes. The nanotubes were formed when the expected reaction temperature reached to 130 °C. Energy dispersive X-ray analysis was used to determine the exchange of sodium ions and protons in washing process. The Na
+
ions attached in the nanotubes were removed completely by HCl aqueous solution and deionized water treatments. X-ray diffraction patterns showed the titanate phase of the as-synthesized sample and anatase phase of TiO
2
nanotubes after calcination process at 400 °C for 2 h.
Background
The simple scoring systems for predicting the outcome of sepsis in intensive care units (ICUs) are few, especially for limited-resource settings. Therefore, this study aimed to evaluate ...the accuracy of the quick Sequential (Sepsis-Related) Organ Failure Assessment (qSOFA) score in predicting the mortality of ICU patients with sepsis in Vietnam.
Methods
We did a multicenter cross-sectional study of patients with sepsis (≥18 years old) presenting to 15 adult ICUs throughout Vietnam on the specified days (i.e., 9th January, 3rd April, 3rd July, and 9th October) representing the different seasons of 2019. The primary and secondary outcomes were the hospital and ICU all-cause mortalities, respectively. The area under the receiver operating characteristic curve (AUROC) was calculated to determine the discriminatory ability of the qSOFA score for deaths in the hospital and ICU. The cut-off value of the qSOFA scores was determined by the receiver operating characteristic curve analysis. Upon ICU admission, factors associated with the hospital and ICU mortalities were assessed in univariable and multivariable logistic models.
Results
Of 252 patients, 40.1% died in the hospital, and 33.3% died in the ICU. The qSOFA score had a poor discriminatory ability for both the hospital (AUROC: 0.610 95% CI: 0.538 to 0.681; cut-off value: ≥2.5; sensitivity: 34.7%; specificity: 84.1%; P
AUROC
= 0.003) and ICU (AUROC: 0.619 95% CI: 0.544 to 0.694; cutoff value: ≥2.5; sensitivity: 36.9%; specificity: 83.3%; P
AUROC
= 0.002) mortalities. However, multivariable logistic regression analyses show that the qSOFA score of 3 was independently associated with the increased risk of deaths in both the hospital (adjusted odds ratio, AOR: 3.358; 95% confidence interval, CI: 1.756 to 6.422) and the ICU (AOR: 3.060; 95% CI: 1.651 to 5.671).
Conclusion
In our study, despite having a poor discriminatory value, the qSOFA score seems worthwhile in predicting mortality in ICU patients with sepsis in limited-resource settings.
Clinical trial registration
Clinical trials registry–India:
CTRI/2019/01/016898
This study aimed to investigate antimicrobial resistance profile, multidrug resistance (MDR), and molecular characteristics of pathogenic Staphylococcus aureus isolates from hospitalized Vietnamese ...adults. Two hundred and twenty-three pathogenic S. aureus isolates were obtained from the hospitals located in 3 regions of Vietnam. The minimum inhibitory concentrations were determined to detect the antibiotic susceptibility of the isolates. The molecular characteristics of S. aureus isolates were investigated through antibiotic-resistant genes analysis, staphylococcal cassette chromosome mec typing, pulsed-field gel electrophoresis, and multilocus sequence typing. Substantial differences among the 3 regions were found in the prevalence rates of methicillin-resistant S. aureus (north: 48.6%, central: 58.7%, south: 78.9%) and MDR (north: 65.8%, central: 79.7%, and south: 84.2%). The prevalence rates of the genes tetK/M, aacA/aphD, ermA/B/C, and mecA increased substantially from north to south. ST188-SCCmecIV and ST239-SCCmecII isolates were most commonly found in the 2 largest clusters. ST188 predominance was observed in the largest cluster in methicillin-resistant and methicillin-sensitive S. aureus isolates, including SCCmecIII and SCCmecIVa, in fatal cases. Our results revealed a high occurrence of MDR and possible north−south trend in antibiotic resistance profile, MDR patterns, and frequency of antibiotic-conferring genes among S. aureus isolates. ST188 predominance raises concerns about the global importance of host-adapted ST188 in East Asian populations.
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