Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions

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

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

Operation of Different Reverse Osmosis (RO) Membrane Modules for the Treatment of High-Strength Wastewater to Enhance the Recovery of Clean Water—A Case Study in Bac Ninh, Vietnam

In this study, a wastewater treatment plant (WWTP) in Vietnam receiving high-strength wastewater with COD of about 30,000 mg/L and various heavy metals from industries was treated by different RO membrane modules in order to meet the stringent national discharge standard and recover wastewater for reuse. The Fenton and coagulation pre-treatments were employed based on optimal conditions, which were experimentally pre-determined. For the RO membrane system, the two-stage treatment employed a plate frame RO (PFRO) followed by spiral wound RO (SPRO) to obtain high-quality permeate, while the high-pressure PFRO (HP PFRO) module was employed for the recovery of concentrated streams from the PFRO unit. As a result, a significant COD removal efficiency of 99.62% was achieved in the SPRO module. The heavy metal concentrations (i.e., Cu, Fe, Zn, Mn, Cr) measured in the output mostly met the standards for discharge levels. A significant decrease in electrical conductivity (EC) to below 250 µS/cm was achieved. In addition, high rates of water recovery were achieved from the RO modules (i.e., PFRO 63%, HP PFRO 9–12%, SPRO > 80–90%). The high-quality treated wastewater was thus suitable for reuse purposes. This study highlights the feasibility of RO membranes for practical treatment of high-strength wastewater and provides valuable data for the WWTP operator

Operation of Different Reverse Osmosis (RO) Membrane Modules for the Treatment of High-Strength Wastewater to Enhance the Recovery of Clean Water&mdash;A Case Study in Bac Ninh, Vietnam

In this study, a wastewater treatment plant (WWTP) in Vietnam receiving high-strength wastewater with COD of about 30,000 mg/L and various heavy metals from industries was treated by different RO membrane modules in order to meet the stringent national discharge standard and recover wastewater for reuse. The Fenton and coagulation pre-treatments were employed based on optimal conditions, which were experimentally pre-determined. For the RO membrane system, the two-stage treatment employed a plate frame RO (PFRO) followed by spiral wound RO (SPRO) to obtain high-quality permeate, while the high-pressure PFRO (HP PFRO) module was employed for the recovery of concentrated streams from the PFRO unit. As a result, a significant COD removal efficiency of 99.62% was achieved in the SPRO module. The heavy metal concentrations (i.e., Cu, Fe, Zn, Mn, Cr) measured in the output mostly met the standards for discharge levels. A significant decrease in electrical conductivity (EC) to below 250 &micro;S/cm was achieved. In addition, high rates of water recovery were achieved from the RO modules (i.e., PFRO 63%, HP PFRO 9&ndash;12%, SPRO &gt; 80&ndash;90%). The high-quality treated wastewater was thus suitable for reuse purposes. This study highlights the feasibility of RO membranes for practical treatment of high-strength wastewater and provides valuable data for the WWTP operator

From drainage to resource: a practice approach to reuse greywater for household irrigation purposes

The United Nations indicates that available freshwater resources will decrease significantly due to pollution growth and urbanization; two-thirds of the world's population may face water shortages by 2030. Extended use of greywater is an alternative option for reducing potable water consumption in urban areas. Recently, the reuse of treated greywater for home gardens, peri-urban agriculture, and landscaping has become a widespread concern in many developing countries. This paper presents a study on a low-cost system that can perform greywater treatment for household use. This treatment system employed physical filtration by ceramic filters, quartz gravel, hollow fiber membrane, and UV disinfection. Three greywater samples collected from the kitchen, washing basins, and bathroom were investigated. The operation process determines the system's effectiveness by considering turbidity, coliform, Biochemical Oxygen Demand (BOD5), and Chemical Oxygen Demand (COD) concentration of the inlet and outlet water. As a result, high removal efficiency (i.e., >60%) could be obtained for each investigated parameter. Results also showed that grey water generated from washing basins has the highest potential for reuse since the water quality after treatment satisfies the water reuse standards for household irrigation. The findings encourage further exploration and implementation of greywater reuse practices. HIGHLIGHTS A greywater treatment system with six filter layers and a PVDF hollow fiber membrane was investigated.; The system's performance was assessed by measuring the pH, turbidity, BOD5, COD, and coliform concentration.; UV disinfection made washing basin greywater suitable for garden irrigation, meeting international standards.; An efficient and cost-effective system for greywater reuse in Southeast Asian households.

Ocena jakości wody surowej na potrzeby planu poprawy w stacji uzdatniania wody Thu Duc w Wietnamie

A conventional water treatment process is currently operated at Thu Duc Water Treatment Plant (TDWTP, Ho Chi Minh City, Vietnam) in which raw water is collected from Dong Nai River at Hoa An water intake and pumping station. The raw water quality is currently fluctuated due to the effects of run-off flows which has been increasing recently. This issue directly affects the operation and performance of existing treatment process at TDWTP since the current treatment are all based on traditional technologies and have been operating for a long time. This study is conducted to evaluate the quality of raw water collected at Hoa An intake station during the period of 2018–2020 with the aim to support the consideration of improvement and enhance the operation efficiency at TDWTP. The raw water quality is evaluated by investigating physico-chemical and biological parameters during the 36 months monitoring. This helps to produce a feasible and reliable results which may then can be used as a scientific database for the improvement plan at TDWTP. Results show that the changes of water quality during the investigated time is so complicated, and the concentration of most monitoring parameters is highly seasonal fluctuated. Specifically, the amounts of organic matters, microorganism, nitrogen compounds (NH4 +, NO2 - , NO3 - ) tend to increase strongly, which may be due to the urbanization and industrialization. The management of run-off flows on upstream of water intake and pumping station is also an important aspect which need to be considered to prevent the diffusion and spread of pollution. In addition, the effects of climate changes are the important reason which leads to the seasonal changes of flow and water quality. These issues cause a big challenge for TDWTP to maintain the treatment efficiency and overall performance. This study also proposes several management and technical solutions to address the changes of raw water quality in the future, which may be useful for TDWTP during their consideration to improve the treatment process.Konwencjonalny proces uzdatniania wody jest obecnie prowadzony w zakładzie uzdatniania wody Thu Duc (TDWTP, miasto Ho Chi Minh, Wietnam), w którym surowa woda jest pobierana z rzeki Dong Nai i z przepompowni Hoa An. Jakość wody surowej podlega obecnie wahaniom ze względu na skutki spływów, które ostatnio nasilają się. Kwestia ta ma bezpośredni wpływ na funkcjonowanie i wydajność istniejących procesów oczyszczania w TDWTP, gdyż wszystkie obecne działające oczyszczalnie oparte są na tradycyjnych technologiach i działają od dłuższego czasu. Niniejsze badanie ma na celu ocenę jakości wody surowej pobieranej ze stacji poboru Hoa An w latach 2018–2020 w celu wsparcia rozważań nad poprawą i zwiększeniem efektywności działania TDWTP. Jakość wody surowej oceniana jest poprzez badanie parametrów fizykochemicznych i biologicznych podczas 36-miesięcznego monitoringu. Pozwoliłó to uzyskanie wiarygodnych wyników, które następnie mogą być wykorzystane jako naukowa baza danych dla planu modernizacji TDWTP. Wyniki pokazują, że zmiany jakości wody w badanym okresie są bardzo złożone, a stężenia większości parametrów monitoringu podlegają dużym wahaniom sezonowym. Szczególnie silnie wzrastają ilości materii organicznej, mikroorganizmów, związków azotu (NH4 +, NO2 - , NO3 - ), co może być spowodowane urbanizacją i uprzemysłowieniem. Ważnym aspektem, który należy wziąć pod uwagę, aby zapobiec rozprzestrzenianiu się zanieczyszczeń, jest również zarządzanie przepływami odpływowymi przed ujęciem wody i przepompownią. Ponadto skutki zmian klimatu są ważną przyczyną sezonowych zmian przepływu i jakości wody. Kwestie te stanowią duże wyzwanie dla TDWTP, aby utrzymać skuteczność oczyszczania i ogólną wydajność. W niniejszym opracowaniu zaproponowano również kilka rozwiązań w zakresie zarządzania i rozwiązań technicznych mających na celu zajęcie się zmianami jakości wody surowej w przyszłości, które mogą być przydatne dla TDWTP podczas rozważań nad poprawą procesu oczyszczania

Exploring characteristics of the corner sections of a domain wall trap nanostructure with the two-field direction method

A 2D polycrystalline permalloy domain wall trap nanostructure with a thickness of 20 nm was studied. The structure was alternatively designed and patterned using QCAD/L-Edit software and focused-ion beam technique. With this design, a magnetic domain wall can be created and propagated with a sequence of two-field directions in a Lorentz microscopy. The trap consists of two horizontal nanowires and three 90°-tilted ones. Each nanowire has an in-plane dimension of 200 × 1000 nm(2). The trap corners were curved to allow a created domain wall that easily moves through the structure. A head-to-head domain-wall aims to create using a continuous field, this created wall can be propagated in the trap using a sequence of two-field directions. The designed trap was simulated using the Object Oriented Micro-Magnetic Framework software. Lorentz microscopy and simulation results indicate that the propagation of a domain wall is strongly affected by the precise roughness behavior of the trap elements. Domain wall pinning and transformation of wall chirality are sensitively correlated to the corner sections of the trap structure and field directions at a certain regime. Using the two-field direction method enables us to explore characteristics of the corner sections of the patterned trap nanostructure. This study is vital to fabricate an optimal nano-trap which supports a reproducible domain wall motion. This also suggests a useful method for the domain wall propagation using sequences of two-field directions. This work provides a better understanding of wall creation and propagation in polycrystalline permalloy curved nanowires which are of interest for concepts of nonvolatile data storage devices

VinDr-CXR: An open dataset of chest X-rays with radiologist’s annotations

Measurement(s) diseases and abnormal findings from chest X-ray scans Technology Type(s) AI is used to detect diseases and abnormal findings Sample Characteristic - Location Vietna