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The study was conducted from June to December 2021 to assess the technical – financial aspect and the existing advantages and difficulties of the giant freshwater prawn culture in coconut garden ditch culture by interviewing 32 farming households in Thanh Phu district, Ben Tre Province. The study results showed that the average area for each ditch was 0.38 ± 0.29 ha, with density stocking 4.15 ± 1.21 PL/m2. For prawns were harvested after over 8 months, the prawn yield was 421.08 ± 172.21 ton/ha/crop, the profit was 34.02 ± 14.02 million VND/ha/crop and the benefit ratio was 1.33 ± 0.56 times. The yield and the profits were affected by density stocking and nursing survival rate. Besides the advantages of labor resources, natural conditions, and ease and less risk of giant freshwater prawn culture; however, the system currently faces many difficulties, such as lower nursing survival rate, unguaranteed quality, and quantity of postlarvae, salinity intrusion, unstableproduct market. Therefore, in order to contribute to sustainable aquaculture development, the necessary solutions include (1) providing high quality and quantity of postlarvae; (2) using settling ponds to have active water; (3) building and improving infrastructure, and irrigation systems to prevent salinity intrusion; and (4) finding the product market.

This study aimed to determine the agreement between a rapid diagnostic test (RDT) and a dried blood spot (DBS)-based electrochemiluminescence immunoassay (ECLIA) of hepatitis B surface antigen and to compare the costs of conducting serosurveys using RDTs and DBS in a field setting.A serosurvey was conducted in the South Central Coast region of Vietnam in May 2019. Participants aged 1-39 years were recruited using a four-stage random sampling method and tested for hepatitis B surface antigen using an RDT kit (Alere Determine) and a DBS-based ECLIA. The agreement between the RDT and the DBS-based ECLIA was assessed using cross-tabulation and Cohen kappa. Cost data were categorized by input (personnel, transportation, field consumables, laboratory consumables, and capital item/overhead) and survey phase (survey preparation, data/biospecimen collection, laboratory testing, and coordination).A total of 2072 participants were analyzed. There was a 99% agreement between the RDT and the DBS-based ECLIA results, with a Cohen kappa of 0.9. The estimated cost of conducting a serosurvey by DBS was UD $75,291, whereas RDT was $53,182.RDTs and DBS-based ECLIA provide test results with high agreements. RDTs are a better option in terms of cost, whereas the DBS-based ECLIA may be useful when evaluating multiple infectious diseases.

Combination products are therapeutic and diagnostic products that include two or more of the following: drug, biologic, and device. These products are needed for enhanced clinical outcomes and have more than one Mode of Action (MOA). Therefore, they require a more complex regulatory pathway and compliance with a minimum of two (2) sets of regulatory standards. In 2013, the 21 Code of Federal Regulations (CFR) Part 4 was published to clarify the applicable GMP regulations when drugs, devices, or biological products are included. The FDA (U.S. Food and Drug Administration) released additional guidance in 2017 to streamline the regulatory framework and provide transparency about demonstrating GMP compliance when multiple regulatory standards overlap. This paper summarizes the Current Good Manufacturing Practice (CGMP) requirements for drug-device combination products (Biologic combinations are not discussed in this paper). Emphasis is placed on considerations for structuring a compliant drug-device stability program, including the use of bracketing and matrixing the test schedule to support the establishment of the product expiry date and how legacy products can be evaluated to meet current standards.

Mild traumatic brain injuries (mTBI) are highly prevalent during early childhood and can lead to behavioral difficulties. Parent report questionnaires are widely used to assess children's behavior, but they are subject to parental bias. The aim of this study was to investigate parental discrepancies in internalized and externalized behavior ratings of children who sustain mTBI in early childhood (i.e., between 18 and 60 months) and to determine if parenting stress or family burden related to the injury contribute to parental discrepancies. Mothers and fathers of 85 children with mTBI, 58 orthopedic injured (OI), and 82 typically developing children (TDC) completed the Child Behavior Checklist 6 months after the injury. The primary caregiver completed the Parental Distress subscale of the Parenting Stress Index and the Family Burden of Injury Interview. Mothers reported more internalized and externalized behavior problems than fathers in the mTBI group. No group difference was found in the OI or TDC groups. Neither parenting stress nor family burden related to the injury predicted discrepancies in behavior ratings. Mothers' and fathers' perceptions of behavior after their young child sustains mTBI appear to differ, suggesting that both parents' views are useful in understanding outcome. This difference was not found in either of the comparison groups indicating that factors related to mTBI may underlie the rating discrepancies.

Purpose: To quantify the amino acids obtained from black garlic (Allium sativum L.) using high-performance liquid chromatography after derivatization with 9-fluorenylmethyloxycarbonyl chloride (FMOC-Cl). Methods: Homogenized black garlic samples were derivatized with 9-fluorenylmethyloxycarbonyl chloride (FMOC-Cl) reagent in borate buffer at 30 °C for 60 min. The black garlic samples were hydrolyzed with 5.0 mL HCl (6 N) and neutralized to pH 5 – 6 by adding 30 mL NaOH (1 N). Amino acids were measured using high-performance liquid chromatography coupled with a fluorescence detector after hydrolysis and derivatization with FMOC-Cl reagent. Gradient elution mixture consisted of acetonitrile, methanol, and water at a flow rate of 1.0 mL/min, 0.2 % ammonium acetate, and 0.1 % formic acid. Results: The ranges of the limits of detection and quantification were 30 and 100 g/mL, respectively. The overall intra- and inter-day variations (%RSD) for the precision findings were smaller than 3.43 and 4.63 %, respectively. The accuracy of the developed method was good, ranging from 90.9 to 106.8 %. The amino acids of six black garlic products from the market were determined using the suggested approach. The findings indicated that glutamic acid, the main amino acid, is present in the maximum concentration (564.64 – 1333.9 mg/100 g) in black garlic. Conclusion: The validated method is for the determination of the amino acids in black garlic and would be a helpful tool for the quality control of products containing black garlic.

Soil factors, especially metal elements in the soil, play a significant role in forming and accumulating secondary metabolites, which determine the medicinal properties of medicinal herbs. In this study, the concentrations of some metal elements (K, Mn, Fe, Cu, Zn, and Cr) in Cam Mountain and Tinh Bien Town, An Giang Province, Vietnam, were determined using the XRF method. We simultaneously determined the total phenolic and flavonoid content of some medicinal herbs collected from the collected soil sample areas, thereby assessing the influence of these elements on the formation of secondary metabolites in medicinal plants. The results showed that K, Mn, and Cr were mainly concentrated in the topsoil and transition layers; Fe and Cu elements tended to concentrate in the transition layer and the subsoil when surveying the soil profile. K, Mn, Cu, and Cr concentrations were more focused in Tinh Bien area, while Fe and Zn had higher concentrations at Cam Mountain. Additionally, results from evaluating the relationship between the content of the elements in the soil and the content of two active compounds also showed the corresponding relationship between Cr/Phenolic, Cu/Phenolic, and Zn/Flavonoid (R2 = 0.74; R2 = 0.75; R2 = 0.90, respectively) with the corresponding correlation equations at level six.

This study was conducted to evaluate the growth rate, survival rate, and biomass of all-male monosex giant freshwater prawn Macrobrachium rosenbergii. The experiment is in a completely randomized design with threereplications applying two treatments: (1) treatment involving the shrimps with pincers at a random selection – the control group and (2) treatment involving the shrimps without pincers – the experimental group. Each replication was carried out in a 6m3 shrimp culture tank with the density of 15 shrimps/m3 and the salinity of 5o=oo. The initial weight and length of the selected shrimps reached 7.29±2.01g/ind, and 9.12±1.03 cm, respectively. The results showed that after 90 days of treatment breaking the pincers, each individual shrimp weighs 26.87 g/ and its body is 13.08 cm in length, but it was not significantly different from the treatment without breaking pincers. The survival rate and biomass of shrimp in the treatment of breaking pincers were 84.44% and 361 ± 14.50 g/m3, which were higher and statistically significant compared to those in the treatment without breaking pincers.

The American Association of Pharmaceutical Scientists (AAPS) Chemistry, Manufacturing, and Controls (CMC) Community hosted two virtual panel discussions focusing on several novel regulatory review pathways for innovative oncology products: Real-Time Oncology Review (RTOR), Project Orbis, and the Product Quality Assessment Aid (PQAAid). The panel sessions were held on August 27, 2021, for the discussion of RTOR, and January 21, 2022, for the discussion of Project Orbis and the PQAAid. Both panel sessions included representatives from the US Food and Drug Administration (FDA) and subject matter experts from the pharmaceutical and biotechnology industries, with the aim of facilitating knowledge sharing on CMC-specific advantages, challenges, eligibility criteria for participation, and operational modifications instituted through the utilization of these acceleration initiatives. Key topics included managing cross-regional regulatory CMC requirements, adapting to expedited development timelines, coordinating interactions between health authorities and industry, and potential opportunities for future improvement and expansion of these programs. As RTOR, Project Orbis, and PQAAid are relatively new initiatives, the experiences shared by the panel experts are valuable for providing deeper insight into these new regulatory pathways and processes.

Previous major infection outbreaks have shown the importance of timely information about local conditions in guiding support and health care interventions. During the COVID-19 pandemic, UNICEF deve...

Calgary-based installation artist and printmaker Kim Huynh’s projects are profoundly aware of materiality and ways in which it can encourage us to jump out of the ruts and customary ways of categorizing and thinking in late Capitalism. The media that Kim Huynh adopts can range from the extraordinary to the banal, from a vast string of pearls to orange peels. This short interview with Kim Huynh investigates matters that are material and conceptual, incorporated into two projects referencing social injustice and embodied female experiences.

Although top management teams use their human capital, social capital, and cognition (i.e., dynamic managerial capabilities) to drive strategic change in their firms, faultlines within these teams may dampen the strategic change that they produce. While boards can enable but also restrict these change efforts, we know little about how precisely a board's monitoring and advice-giving condition the impact of the top management team's dynamic managerial capabilities on strategic change. We clarify how intense monitoring and advice-giving affect strategic change when faultlines between the top management team's and board's dynamic managerial capabilities are more or less salient. We explain that intense monitoring further stifles both the breadth and speed of strategic change that can be accomplished, and that this is more pronounced when the faultlines between the two bodies are strong. Furthermore, we outline that intensive advice-giving can be beneficial in improving the breadth of strategic change, but more so when these faultlines are weak and less so when they are strong. Notably we illuminate that the reverse happens in terms of speed of strategic change: intensive advice-giving can be detrimental engendering a further dampening of strategic change speed which is more pronounced when these faultlines are strong but less when they are weak.

This study was conducted through the direct interview of 90 households applying the alternative system of culturing frogs in Tra Vinh Province from 9/2020 to 3/2020. The study aimed to determine current status of frog farming. The collected data includes the technical and financial aspect of culturing frogs. The results showedthat there are two models of frog farming: culturing frogs in canvas (65.56% of households), and culturing frogs in cages (34.44% of households); Both models applied the same average farming area of 36.27 m2 with stocking density of 115 inds/m2. After 2.6 months of culturing, the average frog size was 257 g. The average frogyield produced 21,024 kg/1,000 m2/crop and the net income of 100 million VND/1,000 m2/crop was achieved. The result indicated that it is easy to raise frogs because the households can take advantage of the surrounding area of their houses for raising frogs and therefore the farmers’ could improve by this method.

This study was conducted to evaluate the current status of the intensive white-leg shrimp farming in earthen system and tarpaulin pond system in Tra Vinh Province by interviewing 110 farmers in Trà Vinh from May to December of 2019. The results of the study showed that an average stocking density in earthen systemand tarpaulin pond system were at 195 and 87 inds/m2 and the number of crops for earthen and tarpaulin ponds are respectively from 1 - 2 crops and 2 - 3 crops per year. The harvested shrimp size and the productivity in tarpaulin ponds (35 inds /kg; 48 tons/ha/crop) were significantly higher than those in the in earthen ponds (58 inds /kg; 12 tons/ha/crop). The net income obtained from the tarpaulin ponds model (1.760 millionVND/ha/crop) was significantly higher than that in the earthen ponds (267 million VND/ha/crop). Food change ratio in tarpaulin ponds was higher than in earthen ponds. The advantages and disadvantages of white - leg shrimp farmers in two models are also mentioned in this report.

Rice husk is a common agricultural waste and an abundant source in Viet Nam. In terms of composition, rice husk is a silica-rich material (SiO2) so it can be used to prepare negative electrode materials for rechargeable Li-ion batteries. Recent processes of synthesizing the silica materials for the rechargeable batteries are often complex, expensive, and energy-intensive. In this study, KOH was used to treat rice husk ash to obtain SiO2/C porous composite materials. X-ray diffraction results (XRD) showed that the diffraction peak between 22o and 23o (2q ) was characterized of SiO2 material, and the other peaks around 43-44o was featured of carbon material. Scanning electron microscope image (SEM) showed the porous structure with the pore size 3-5 mm.Besides, the amorphous structure with coverage layers was also confirmed through the Transmission Electron Microscope (TEM) images. Preliminary electrochemical results demonstratedthat Li-ion coin cell using the SiO2/C anode material exhibited a high capacity of 1200 mAh/g at a discharge current of 1.0 A/g and maintained 1000 mAh/g after 100 cycles. SiO2/C materials prepared from rice husks were highly promising for battery application thanks to their low cost, stable performance, environmental friendliness, and easy expansion for production scale.

The COVID-19 pandemic is unprecedented. The pandemic not only induced a public health crisis, but has led to severe economic, social, and educational crises. Across economies and societies, the distributional consequences of the pandemic have been uneven. Among groups living in vulnerable conditions, the pandemic substantially magnified the inequality gaps, with possible negative implications for these individuals' long-term physical, socioeconomic, and mental wellbeing. This Viewpoint proposes priority, programmatic, and policy recommendations that governments, resource partners, and relevant stakeholders should consider in formulating medium-term to long-term strategies for preventing the spread of COVID-19, addressing the virus's impacts, and decreasing health inequalities. The world is at a never more crucial moment, requiring collaboration and cooperation from all sectors to mitigate the inequality gaps and improve people's health and wellbeing with universal health coverage and social protection, in addition to implementation of the health in all policies approach.

Vietnam introduced a 3-dose hepatitis B (HBV) immunization program comprising 1 dose immediately after birth and 2 or 3 in infancy in the past 20 years, but the impact of the vaccine has not been systematically evaluated. Thus, we conducted this survey aiming to estimate the age-specific chronic HBV prevalence in the general population and to evaluate HBV immunization effectiveness.Population-based, four-stage cluster sampling was used in the South Central Coast region of Vietnam. The point-of-care Determine rapid test was used to assess hepatitis B surface antigen (HBsAg) positivity.A total of 2,075 samples were included in the study. HBsAg prevalence was significantly higher among adults aged 20-39 years than in the population aged 1-19 years (8.0% [95% confidence interval 5.0-12.0] vs. 2.0% [95% confidence interval 1.0-6.0], p0.01). HBsAg prevalence decreased after implementation of the 3-dose vaccination schedule during infancy from 1997 to 2002, whereas the change in prevalence after implementation of the birth dosing was not significant. A slight increase in HBsAg prevalence was observed for the cohort born in 2011, 2012, and 2013, when there was a vaccine shortage and media reports of immunization resistance.This is the first population-based assessment of the introduction of the HBV vaccine in Vietnam performed by estimating the HBsAg prevalence across a wide range of ages. The results showed that the HBV immunization policy effectively reduces HBsAg prevalence in general, although birth dosing of the vaccine and low immunization coverage should be carefully monitored.

Objective To assess the safety and efficacy of Tesomet (tesofensine plus metoprolol) in adults with hypothalamic obesity, a rare disease with no approved therapy. Research Design and Methods Twenty-one adults with hypothalamic obesity (16 females, 5 males) were randomized to Tesomet (0.5 mg tesofensine/50 mg metoprolol) (n=14) or placebo (n=8) during a 24-week double-blind period. On completion of the double-blind period, 17 (81%) subjects (11 Tesomet; 6 placebo) entered in to a 24-week open-label extension period and were treated with Tesomet. The primary endpoint was safety while secondary endpoints included measures of body weight, waist circumference, and body composition. Trial NCT03845075. Results The most common adverse events following the 24-week double-blind period and the 24-week open-label extension period were sleep disorder, dizziness, dry mouth, and headache; the majority of these adverse events were mild to moderate in severity. No significant nor clinically meaningful changes in heart rate or blood pressure were observed during the study. On completion of the double-blind period mean change in body weight (kg) was -7.84 for the Tesomet group versus -0.34 kg for the placebo group (P=0. 03). At the end of the open-label extension period mean change in body weight (kg) from baseline was -6.34 for the Tesomet-Tesomet group and -6. 03 for the placebo-Tesomet group. On completion of the double-blind period mean change in waist circumference (cm) was -7. 09 cm for the Tesomet group versus -1.16 for the placebo group (P=NS). At the end of the open-label extension period mean change in waist circumference (cm) from baseline was -5.73 for the Tesomet-Tesomet group and -3. 04 for the placebo-Tesomet group. On completion of the double-blind period mean change in fat mass (kg) was -5.28 for the Tesomet group versus -1.11 for the placebo group (P=NS). At the end of the open-label extension period mean change in fat mass (kg) from baseline was -4.84 for the Tesomet-Tesomet group and -3.85 for the placebo-Tesomet group. On completion of the double-blind period mean change in lean tissue mass (kg) was -2.76 for the Tesomet group versus 0.36 for the placebo group (P Discussion Tesomet was generally well tolerated after 48 weeks treatment and resulted in clinically meaningful improvements in body weight and body composition measures in adults with hypothalamic obesity. In contrast to previous studies of tesofensine monotherapy in general obesity, no significant nor clinically meaningful changes in cardiovascular measures were observed during the study. Conclusion Tesomet is a promising new experimental treatment for hypothalamic obesity. A randomized, placebo controlled, multi-center, dose-finding, Phase 2b study has now been initiated. Presentation: No date and time listed

Context Hypothalamic injury often leads to rapid, intractable weight gain causing hypothalamic obesity, which is associated with increased risk of cardiovascular and metabolic morbidity and mortality. There are no approved or effective pharmacological treatments for hypothalamic obesity, and conventional lifestyle management remains ineffective. Objective To investigate the safety and efficacy of Tesomet (0.5 mg tesofensine/50 mg metoprolol) in adults with hypothalamic obesity. Methods Twenty-one adults with hypothalamic obesity (16 females) were randomized to Tesomet (0.5 mg/50 mg) or placebo for 24 weeks. Patients also received diet/lifestyle counselling. The primary endpoint was safety; secondary endpoints included measures of body weight, appetite scores, quality of life, and metabolic profile. Results Eighteen patients completed 24 weeks. Consent withdrawal, eligibility, and serious adverse events (SAE) unrelated to treatment resulted in dropouts. One patient experienced a Tesomet-related SAE of exacerbated pre-existing anxiety leading to treatment discontinuation. Tesomet-related adverse events were otherwise mostly mild and included sleep disturbances (Tesomet 50%, placebo 13%), dry mouth (Tesomet 43%, placebo 0%), and headache (Tesomet 36%, placebo 0%). No significant differences in heart rate or blood pressure were observed between groups. Compared to placebo, Tesomet resulted in additional mean (95% CI) weight change of −6.3% ((−11.3; −1.3); P = 0.017), increased the number of patients achieving ≥5% weight loss (Tesomet 8/13, placebo 1/8; P = 0.046), and tended to augment the reduction in waist circumference by 5.7 cm ((−0.1; 11.5); P = 0.054). Conclusion Tesomet was welltolerated, did not affect heart rate or blood pressure, and resulted in significant reductions in body weight compared to placebo in adults with hypothalamic obesity.

The Stability Community of the American Association of Pharmaceutical Scientists (AAPS) held a virtual workshop on “Vaccine Stability Considerations to Enable Rapid Development and Deployment”, on March 24-25, 2021. The workshop included distinguished speakers and panelists from across the industry, academia, regulatory agencies, as well as health care leaders. This paper presents a review of the topics covered. Specifically the challenges in accelerating vaccine development and analytical characterization techniques to establish shelf-life were covered. Additionally, vaccine stability modeling using prior knowledge stability models and advanced kinetic analysis played a key in the EUA approaches discussed during the workshop. Finally, the role of stability studies in addressing the challenges of vaccine distribution and deployment during the pandemic were a focus of presentations and panel discussions.Although the workshop did not have any presentation topics directly dedicated to the mRNA vaccines, the techniques discussed are generally applicable. The mRNA vaccine developers were represented in the panel discussions, where experts involved in the EUA approval/deployment stages for this vaccine type could discuss the challenges as applied to their vaccines.

Nano carbon-semiconductor hybrid materials such as graphene and zinc oxide (ZnO) have been vigorously explored for their direct electron transfer properties and high specific surface areas. We fabricated a three-dimensional anodic electrode catalyst nanostructure for a direct glucose fuel cell (DGFC) utilizing two-dimensional monolayer graphene and one-dimensional ZnO nanorods, which accommodate silver/nickel (Ag/Ni) nanoparticle catalyst. Glucose, as an unlimited and safe natural energy resource, has become the most popular fuel for energy storage. Ag and Ni nanoparticles, having superior catalytic activities and anti-poisoning effect, respectively, demonstrate a 73-times enhanced cell performance (550 µW cm−2 or 8 mW mg−1) when deposited on zinc oxide nanorods with a small amount of ∼0.069 mg in 0.5 M of glucose and 1 M of KOH solution at 60 oC. This three-dimensional anodic electrode catalyst nanostructure presents promise to open up a new generation of fuel cells with non-Pt, low mass loading of catalyst, and 3D nanostructure electrodes for high electrochemical performances.

The American Association of Pharmaceutical Scientists (AAPS) Chemistry, Manufacturing, and Control (CMC) Community hosted a virtual panel discussion on December 9, 2020, to provide a forum to discuss N-nitrosamine control strategies in the pharmaceutical and biotechnology industries. The panel included staff from the US Food and Drug Administration (FDA) and industry subject matter experts. Meeting topics included acceptable intake levels for nitrosamine impurities, definitions of "acceptable level of risk," water as a contributor in nitrosamine risk assessments, nitrosamine impurity control strategies based upon fate/purge data, early vs. late development assessment expectations, application to oncology programs developed under ICH S9, and Drug Master File (DMF) regulatory expectations. During the meeting, divergence in global health authority expectations was additionally discussed. One of the most important outputs from this AAPS panel discussion was the criticality of continued dialog between industry and health authorities to help understand actual versus perceived risks and provide pragmatic, scientifically justified solutions to ensure patients are provided with an uninterrupted supply of safe medicines based on globally harmonized requirements.

Background In 2016-2017, 68 women in Southern Vietnam had RT-PCR confirmed Zika virus (ZIKV) infection during pregnancy. We report here the outcomes of the pregnancies and the virological analyses related to this outbreak. Methods We collected clinical and epidemiological information from the women who were enrolled in the study. Medical records related to the pregnancy in 2016–2017 were retrieved for those who were not able to be enrolled in the study. Children born to women with ZIKV infection during pregnancy were also enrolled. Serum samples were evaluated for presence of ZIKV antibodies. Phylogenetic analyses were performed on Zika virus genomes sequenced from the 2016–2017 serum samples. Findings Of the 68 pregnancies, 58 were livebirths and 10 were medically terminated. Four of the medical records from cases of fetal demise were able to be retrieved, of which one was consistent with congenital ZIKV infection. Of the 58 women with a livebirth, 21 participated in the follow-up investigation. All but two women had serologic evidence of ZIKV infection. Of the 21 children included in the study (mean age: 30.3 months), 3 had microcephaly at birth. No other clinical abnormalities were reported and no differences in neurodevelopment were observed compared to a control group. Phylogenetic analysis revealed a clade within the ZIKV Asian lineage and branch at the root of samples from the 2013–2014 French Polynesian outbreak. The prM S139N mutation was not observed. Interpretation We have been able to demonstrate a clade within the ZIKV Asian lineage implicated in adverse pregnancy outcomes in Southern Vietnam. Funding INCEPTION project (PIA/ANR-16-CONV-0005) and a grant received from BNP Paribas Simplidon.

Relatively little is known about the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies and COVID-19-related behaviors in the general population in Vietnam, where the first case of COVID-19 was detected on January 22, 2020. We surveyed a group of 885 blood donors at community blood donation sessions in Ho Chi Minh City from August 27 to November 7, 2020. Blood was collected to test for SARS-CoV-2 IgG antibodies using the plaque reduction neutralization test. We adjusted the seroprevalence by weight for ages 18 to 59 years old obtained from the 2019 population census. The weighted seroprevalence estimate for SARS-CoV-2 neutralizing IgG antibodies was 0.20% (95% CI, 0.05–0.81). Reports of usually or always using a mask in public places were observed at high levels of 28.6% and 67.5%, respectively. The percentages of usually or always washing hands with soap or disinfecting with hand sanitizer after touching items in public places were 48.0% and 37.6%, respectively. Although our findings suggest undocumented exposure to the virus, the seroprevalence of SARS-CoV-2 IgG antibodies among blood donors was low in this city.

A family of layered manganese-pnictide antiferromagnets ${\mathrm{BaMn}}_{2}{Pn}_{2}$ ($\mathit{Pn}$ stands for P, As, Sb, and Bi) has been recently shown to host anomalously large magnetoresistance (MR) with both positive and negative MR components. In search for the microscopic picture of MR in this family, we here report a local-probe $^{55}\mathrm{Mn}$ nuclear magnetic resonance (NMR) study. The zero-field NMR spectra and the temperature dependence of the spin-lattice relaxation rates are fully consistent with the proposed G-type antiferromagnetic order. However, a close inspection of the $^{55}\mathrm{Mn}$ NMR spectra reveals a fine structure, which is due to the weakly localized charge carriers. As these carriers localize and segregate in the presence of electron correlations, they also undergo collective spin fluctuations which freeze-out at low temperatures and thus contribute to the $^{55}\mathrm{Mn}$ spin-lattice relaxation. The characteristic temperatures of the appearance of these additional features in the magnetic response probed by $^{55}\mathrm{Mn}$ NMR correlate well with the anomalies in the resistivity and anomalously large MR, which hints that the two phenomena are connected.

High voltage Li-ion batteries have been expected a forward technology designed for vehicles, marines and other high power and energy density applications 1–3. Among high voltage cathodes, LiNi0.5Mn1.5O4 is considered a promising cathode to reduce the battery cost as well as environmental hazard issues4,5. However, a high operation potential and Mn dissolution brings the most critical challenges for achieving the long cycle-life of Li-ion cell6,7. In this study, we report a rational design of nonflammable electrolyte based on LiBF4 and sulfolane (TMS) mixed with a dimethyl carbonate (DMC) as co-solvent to enhance conductivity. Among different molar ratios, the electrolyte LiBF4: TMS: DMC =1:2:1 in mol. exhibited the highest electrochemical stability (~ 6.1 V vs. Li+/Li) and ionic conductivity up to 1.57 mS.cm-1 at 30 oC. Cycling performance of LNMO/Li half-cell and LNMO/graphite full-cell cycled were carried out using the optimized electrolyte. While half-cells LNMO//Li display a high initial capacity of 118 mAh.g-1 and remain 56.48 % of initial value after 100 cycles, a full cell LNMO//Graphite with an areal loading of 1.0 mAh.cm-2 and low N/P ratio (~1.2) exhibited a better cycling stability than the one using commercial electrolyte 1M LiPF6/EC-DMC, 1:1 in vol (with initial capacity of 87 mAh.g-1 and capacity retention of 18% after 100 cycles8). References Goodenough JB, Kim Y. Challenges for Rechargeable Li Batteries. Chem Mater. 2010;22(3):587-603. Etacheri V, Marom R, Elazari R, Salitra G, Aurbach D. Challenges in the development of advanced Li-ion batteries: a review. Energy Environ Sci. 2011;4(9):3243. Amine K, Kanno R, Tzeng Y. Rechargeable lithium batteries and beyond: Progress, challenges, and future directions. MRS Bull. 2014;39(5):395-401. Kim J-H, Myung S-T, Sun Y-K. Molten salt synthesis of LiNi0.5Mn1.5O4 spinel for 5 V class cathode material of Li-ion secondary battery. Electrochim Acta. 2004;49(2):219-227. Patoux S, Daniel L, Bourbon C. High voltage spinel oxides for Li-ion batteries: From the material research to the application. J Power Sources. 2009;189(1):344-352. Jang DH, Shin YJ, Oh SM. Dissolution of Spinel Oxides and Capacity Losses in 4 V Li / LixMn2O4 Cells. J Electrochem Soc. 1996;143(7):2204-2211. Du Pasquier A, Blyr A, Courjal P. Mechanism for Limited 55°C Storage Performance of Li1.05Mn1.95 O 4 Electrodes. J Electrochem Soc. 1999;146(2):428-436. Wang J, Yamada Y, Sodeyama K, Chiang CH, Tateyama Y, Yamada A. Superconcentrated electrolytes for a high-voltage lithium-ion battery. Nat Commun. 2016;7(1):12032. Acknowledgement This work is supported by Ho Chi Minh city - Department of Science and Technology (DOST) under grant number 54/2020/HĐ-QPTKHCN.