WATER QUALITY STATUS OF WHITE LEG SHRIMP FARMING AREAS IN BINH DAI DISTRICT, BEN TRE PROVINCE, VIETNAM

This study focused on water quality assessment of farmed shrimp ponds in Binh Dai District, Ben Tre Province. The goals of the study were to provide chemical parameters of pond water for farmers, to identify problems and causes in farmed shrimp related to water quality and disease, and to help managers find appropriate solutions to minimize damage to local shrimp farming. Water samples were collected monthly from January to June 2021 from 90 vannamei farmers in six different areas, including Vang Quoi Dong, Dinh Trung Binh Thoi, Phu Long, Phu Vang, and Binh Thang of Binh Dai District. Parameters investigated in this study included pH, alkalinity, NH4+, NH3, NO2- and three other minerals. Water quality parameters were analyzed based on APHA standard analysis methods. The results showed that the water quality of shrimp farming areas in Binh Dai fluctuated from time to time, and water quality parameters were suitable for vannamei shrimp farming. However, the concentration of NO2- was always higher than the permitted threshold. The results from cluster analysis and MANOVA testing showed that water quality of the shrimp farming areas in Binh Dai was significantly different (p < 0.05), especially NO2-, Ca, Mg and alkalinity. These findings suggest that farmers must apply proper solutions for water quality management in each farming area to maximize crop production

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

Natural auxiliary coagulants - perspectives for the treatment of textile wastewater

Applying chemical coagulants and auxiliary coagulants in wastewater treatment has become more popular in Vietnam. Although the efficacy of chemical coagulants has been well recognized, there are disadvantages associated with the use of these products, such as the inefficiency at low temperatures, increasing the residual cation in solution, causing health problems and distribution water, relatively high cost, producing high volume of sludge. Thus, it is desirable to replace these chemical coagulants for products that do not generate such drawbacks, such as natural polymers. In this paper, the authors conducted experiments by using natural auxiliary coagulants extracted from seeds of Cassia fistula (gum MHY) and chemical polymer as auxiliary coagulation to treat textile wastewater with basic polluted parameters: pH = 9.0; COD = 800 mgO2/L, color = 750 Pt-Co. The Jartest experiment results showed that the process efficiency of chemical polymer and gum MHY is not so different, with the COD removal efficiencies of 60.3% and 59.7%; the color removal efficiencies of 87.3% and 87.1%; the SS removal efficiencies of 93.2% and 92.6%. There-fore, coagulants obtained from gum MHY can be applied as the alternatives for chemical polymer in the process of treating textile wastewater.Các ứng dụng chất keo tụ và chất trợ keo tụ hóa học trong xử lý nước thải ngày càng trở nên phổ biến tại Việt Nam. Mặc dù có nhiều ghi nhận về hiệu quả xử lý của chất keo tụ hóa học, phương pháp xử lý này vẫn tồn tại một số nhược điểm như hiệu suất xử lý thấp ở nhiệt độ thấp, nước thải sau khi xử lý còn chứa nhiều hóa chất tiếp tục làm ô nhiễm nguồn tiếp nhận, chi phí xử lý cao và tạo ra nhiều bùn thải. Do đó việc tìm kiếm một phương án xử lý thay thế, chẳng hạn sử dụng polymer tự nhiên, có thể khắc phục những nhược điểm này là rất cần thiết. Nghiên cứu này tiến hành đánh giá hiệu quả sử dụng chất trợ keo tụ sinh học ly trích từ hạt trái Muồng Hoàng yến (Cassia fistula) và chất trợ keo tụ hóa học để xử lý nước thải dệt nhuộm có các thông số ô nhiễm cơ bản: pH = 9,0; COD = 800 mgO2/L, độ màu = 750 Pt-Co. Các thí nghiệm trên bộ Jartest cho thấy hiệu quả xử lý nước thải dệt nhuộm của chất trợ keo tụ gum Muồng Hoàng yến và chất trợ keo tụ hóa học không khác biệt có ý nghĩa với hiệu suất xử lý COD lần lượt là 60,3 và 59,7%; hiệu suất xử lý độ màu là 87,3 và 87,1%; xử lý SS là 93,2 và 92,6%. Kết quả nghiên cứu cho thấy gum hạt Muồng Hoàng yến có thể sử dụng làm chất trợ keo tụ thay thế chất trợ keo tụ hóa học trong xử lý ô nhiễm nước thải dệt nhuộm

Natural auxiliary coagulants - perspectives for the treatment of textile wastewater

Applying chemical coagulants and auxiliary coagulants in wastewater treatment has become more popular in Vietnam. Although the efficacy of chemical coagulants has been well recognized, there are disadvantages associated with the use of these products, such as the inefficiency at low temperatures, increasing the residual cation in solution, causing health problems and distribution water, relatively high cost, producing high volume of sludge. Thus, it is desirable to replace these chemical coagulants for products that do not generate such drawbacks, such as natural polymers. In this paper, the authors conducted experiments by using natural auxiliary coagulants extracted from seeds of Cassia fistula (gum MHY) and chemical polymer as auxiliary coagulation to treat textile wastewater with basic polluted parameters: pH = 9.0; COD = 800 mgO2/L, color = 750 Pt-Co. The Jartest experiment results showed that the process efficiency of chemical polymer and gum MHY is not so different, with the COD removal efficiencies of 60.3% and 59.7%; the color removal efficiencies of 87.3% and 87.1%; the SS removal efficiencies of 93.2% and 92.6%. There-fore, coagulants obtained from gum MHY can be applied as the alternatives for chemical polymer in the process of treating textile wastewater.Các ứng dụng chất keo tụ và chất trợ keo tụ hóa học trong xử lý nước thải ngày càng trở nên phổ biến tại Việt Nam. Mặc dù có nhiều ghi nhận về hiệu quả xử lý của chất keo tụ hóa học, phương pháp xử lý này vẫn tồn tại một số nhược điểm như hiệu suất xử lý thấp ở nhiệt độ thấp, nước thải sau khi xử lý còn chứa nhiều hóa chất tiếp tục làm ô nhiễm nguồn tiếp nhận, chi phí xử lý cao và tạo ra nhiều bùn thải. Do đó việc tìm kiếm một phương án xử lý thay thế, chẳng hạn sử dụng polymer tự nhiên, có thể khắc phục những nhược điểm này là rất cần thiết. Nghiên cứu này tiến hành đánh giá hiệu quả sử dụng chất trợ keo tụ sinh học ly trích từ hạt trái Muồng Hoàng yến (Cassia fistula) và chất trợ keo tụ hóa học để xử lý nước thải dệt nhuộm có các thông số ô nhiễm cơ bản: pH = 9,0; COD = 800 mgO2/L, độ màu = 750 Pt-Co. Các thí nghiệm trên bộ Jartest cho thấy hiệu quả xử lý nước thải dệt nhuộm của chất trợ keo tụ gum Muồng Hoàng yến và chất trợ keo tụ hóa học không khác biệt có ý nghĩa với hiệu suất xử lý COD lần lượt là 60,3 và 59,7%; hiệu suất xử lý độ màu là 87,3 và 87,1%; xử lý SS là 93,2 và 92,6%. Kết quả nghiên cứu cho thấy gum hạt Muồng Hoàng yến có thể sử dụng làm chất trợ keo tụ thay thế chất trợ keo tụ hóa học trong xử lý ô nhiễm nước thải dệt nhuộm

Purification and Characterization of High Purity Nano Zirconia by Liquid-Liquid Extraction Using D2EHPA/p-Xylenes

In this paper, Zr(IV) nitrate solution decomposed from Viet Nam zircon concentrate was the source of zirconium extraction by liquid-liquid extraction (L.L.E). The FT-IR and UV-Vis spectra confirmed the extraction of Zr(IV) by D2EHPA/p-xylenes. There were four stages for the purification of impurities from the Zr matrix. First, the extraction of elements in 3.0 M HNO3 by 50% D2EHPA/p-xylenes was conducted. Second, two scrubbing cycles of impurities using 6.0 M HNO3, 76.5% of the total amount of Zr(IV) were retained in the organic phase, and 23.5% remained in the aqueous phase. Third, the stripping of a macro amount of zirconium from loaded D2EHPA has been effectively carried out using 1.5 M H2SO4 with a stripping efficiency of 99.6%. Fourth, concentrated ammonia was added to the solution Zr(IV) after stripping extraction to form precipitate for calcination at 550 &deg;C for the final products. The refined products were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), EDS, XRF, and diffuse reflectance spectroscopy. The ZrO2 has high purity, is nanospherical, and has a uniform sphere-like morphology with small grain size of less than 30 nm and a bandgap value of about 3.30 eV

A deep learning-based pipeline for analyzing the influences of interfacial mechanochemical microenvironments on spheroid invasion using differential interference contrast microscopic images

Metastasis is the leading cause of cancer-related deaths. During this process, cancer cells are likely to navigate discrete tissue-tissue interfaces, enabling them to infiltrate and spread throughout the body. Three-dimensional (3D) spheroid modeling is receiving more attention due to its strengths in studying the invasive behavior of metastatic cancer cells. While microscopy is a conventional approach for investigating 3D invasion, post-invasion image analysis, which is a time-consuming process, remains a significant challenge for researchers. In this study, we presented an image processing pipeline that utilized a deep learning (DL) solution, with an encoder-decoder architecture, to assess and characterize the invasion dynamics of tumor spheroids. The developed models, equipped with feature extraction and measurement capabilities, could be successfully utilized for the automated segmentation of the invasive protrusions as well as the core region of spheroids situated within interfacial microenvironments with distinct mechanochemical factors. Our findings suggest that a combination of the spheroid culture and DL-based image analysis enable identification of time-lapse migratory patterns for tumor spheroids above matrix-substrate interfaces, thus paving the foundation for delineating the mechanism of local invasion during cancer metastasis

Ce3+/Ce4+-Doped ZrO2/CuO Nanocomposite for Enhanced Photocatalytic Degradation of Methylene Blue under Visible Light

In recent years, photocatalysis has been used as an environmentally friendly method for the degradation of organic pigments in water. In this study, Ce3+/Ce4+-doped ZrO2/CuO as a mixed semiconductor oxide was successfully prepared by a one-step hydrothermal method. The Ce3+/Ce4+-doped ZrO2/CuO has shown high degradation efficiency of methylene blue (MB), and the maximum degradation percentage was observed to be 94.5% at 180 min under irradiation visible light. The photocatalytic activity increases significantly by doping Ce3+/Ce4+ in ZrO2/CuO for MB degradation. Ce3+/Ce4+ doping is shown to reduce the (e-/h+) recombination rate and improve the charge transfer, leading to enhanced photocatalytic activity of materials. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), FTIR, EDS, BET and diffuse reflectance spectroscopy (DRS)

Chemical contamination

Ô nhiễm hóa chất gây tác động xấu đến con người và môi trườn

Accurate measurement of pipe wall reduction: High-precision instrument and minimization of uncertainties

The magnetic flux density method is suited for monitoring the pipe's wall thinning. However, the quantification of gradual reduction is challenging because its small signal is hindered inside the noise floor of magnetic field measurements. In this work, a high-precision instrument for the accurate measurements of small thickness reductions is presented. The size of a magnetizer is optimized with respect to the size range of pipes and minimization of the wobble effect. The flux density is measured by our ultrahigh-sensitivity magnetometer with a resolution of 1.4 nT and dynamic range from 0 to 50 mT. For reliable measurements, we investigate the appropriate strengths of the magnetizing field, appropriate sensor lift-off distances, and minimizing contributions from other uncertainties, such as signals at the pipe's ends and magnetic flux leakages from abrupt defects. Finally, a real-time measurement of the 12.5 % standard wall reduction sample is found to be highly reliable and reproducible. © 2022 Elsevier LtdFALS