An Improved MobileNet for Disease Detection on Tomato Leaves

Tomatoes are widely grown vegetables, and farmers face challenges in caring for them, particularly regarding plant diseases. The MobileNet architecture is renowned for its simplicity and compatibility with mobile devices. This study introduces MobileNet as a deep learning model to enhance disease detection efficiency in tomato plants. The model is evaluated on a dataset of 2,064 tomato leaf images, encompassing early blight, leaf spot, yellow curl, and healthy leaves. Results demonstrate promising accuracy, exceeding 0.980 for disease classification and 0.975 for distinguishing between diseases and healthy cases. Moreover, the proposed model outperforms existing approaches in terms of accuracy and training time for plant leaf disease detection

SỬ DỤNG AXIT OXALIC LÀM CHẤT CHUẨN ĐỂ XÁC ĐỊNH NHU CẦU OXI HÓA HỌC BẰNG PHƯƠNG PHÁP ĐUN HỒI LƯU KÍN – TRẮC QUANG

Potassium hydrogen phthalate (KHP) is used as a standard to determine the chemical oxygen demand (COD) with the closed reflux-colourimetric method (colourimetric method). Besides KHP, it is possible to utilize oxalic acid for this purpose. After boiling at 150 °C for more than 30 minutes in H2SO4 containing Ag2SO4, K2Cr2O7 reacts completely with H2C2O4 at a molar ratio of 1:3. The experimentally determined chemical oxygen demand of H2C2O4 coincides with its theoretical value at 16.0 mg O2/mole H2C2O4. The average COD values of two river water samples, determined with the colourimetric method by using KHP standard and oxalic acid, are not statistically different. Oxalic acid can be used as a standard to determine COD with the colourimetric method.Kali hydro phthalate (KHP) được dùng làm chất chuẩn để xác định nhu cầu oxi hóa học (COD) bằng phương pháp đun hồi lưu kín – trắc quang (phương pháp trắc quang). Ngoài KHP, có thể sử dụng axit oxalic cho mục đích này. Sau khi đun hơn 30 phút ở 150 °C trong môi trường H2SO4 chứa Ag2SO4, K2Cr2O7 sẽ phản ứng hoàn toàn với H2C2O4 theo tỷ lệ mol 1:3. Nhu cầu oxi hóa học của H2C2O4 đã xác định bằng thực nghiệm hoàn toàn trùng khớp với giá trị nhu cầu oxi lý thuyết của hợp chất này là 16,0 mg O2/mol H2C2O4. Nhu cầu oxi hóa học trung bình của hai mẫu nước sông xác định bằng phương pháp trắc quang với hai đường chuẩn dùng KHP và axit oxalic không khác nhau về mặt thống kê. Như vậy, có thể sử dụng axit oxalic làm chất chuẩn để xác định COD bằng phương pháp đã nêu

Immobilizing Alcalase® Enzyme onto Magnetic Nanoparticles

In recent years, magnetic nanoparticles (MNPs) have been applied to numerous biological systems. The nanoparticles are particularly useful in separating biological molecules due to its low price, scalable ability and very little interference. Here, MNPs, which can efficiently separate biocatalysts from reaction media by external magnet, was used to immobilize an alkaline protease (Alcalase®). Covalent attachment of the enzyme to MNPs began with the functionalization of the MNPs' surface with amines (APTES). Then, glutaraldehyde was introduced to link the MNP surface amines with enzyme surface amine residues, typically lysine. Successful covalent bonds were checked by FT-IR. Our results showed the attached enzyme did not affect superparamagnetic property of MNPs, therefore the MNPs-attached enzyme was easily recovered after the reaction. The immobilized enzyme maintained its activities after 10 times of recycle uses

The impact of brand positioning and knowledge on attitude towards brand and purchase intention: A study of organic rice in Ho Chi Minh City

The purpose of this study is to measure the effectiveness of factors of brand, including Brand Positioning, Brand Knowledge, Attitude towards Organic Rice Brand, and Organic Rice Purchase Intention. The survey was conducted with a sample of 224 consumers shopping at four organic rice shops in Ho Chi Minh City. The research was performed by quantitative research methods: Cronbach's Alpha Reliability Analysis, Exploratory Factor Analysis (EFA), Confirm Factor Analysis (CFA), and Structural Equation Modeling (SEM). The research results were conducted in two direct models and the indirect models in which the indirect model was supported. This means that brand positioning and brand knowledge had no direct impact on the Intention to buy organic rice, but only an indirect one through the consumer attitude towards the organic rice brand

Influence of foliar application with Moringa oleifera residue fertilizer on growth, and yield quality of leafy vegetables

Biofertilizers produced from organic materials help to promote the growth, and yield quality of crops and is more environmentally friendly than chemical fertilizers. Moringa oleifera is a leafy vegetable whose leaves are also used to make biofertilizers. The use of moringa non-edible parts in biofertilizer preparation remains under-explored. In this study, a procedure to produce moringa foliar biofertilizer (MFB) from non-edible parts was developed. The effect of composting time (3 to 4 months) on the quality of MFB was investigated, and four-month incubation was found suitable for biofertilizers yield with the highest nitrogen content and optimal pH. Furthermore, the influences of MFB doses (20 to 100 mL per Litre) on the growth of lettuce and mustard spinach were studied. The yield of these leafy vegetables was the highest at 100 mL per Litre of MFB spray. Finally, MFB was compared with other commercial foliar sprays, including chitosan fertilizer and seaweed fertilizer. Each foliar treatment was applied every five days until five days before harvest. Plant height, the number of leaves, canopy diameter, leaf area index, actual yield, ascorbic acid content, and Brix were found to be similar in lettuce sprayed with MFB, chitosan, and seaweed fertilizers. In conclusion, the application of MFB promoted the growth and yield of mustard spinach

Quantitative Analysis of Sodium Metal Deposition and Interphase in Na Metal Batteries

Sodium-ion batteries exhibit significant promise as a viable alternative to current lithium-ion technologies owing to their sustainability, low cost per energy density, reliability, and safety. Despite recent advancements in cathode materials for this category of energy storage systems, the primary challenge in realizing practical applications of sodium-ion systems is the absence of an anode system with high energy density and durability. Although Na metal is the ultimate anode that can facilitate high-energy sodium-ion batteries, its use remains limited due to safety concerns and the high-capacity loss associated with the high reactivity of Na metal. In this study, titration gas chromatography is employed to accurately quantify the sodium inventory loss in ether- and carbonate-based electrolytes. Uniaxial pressure is developed as a powerful tool to control the deposition of sodium metal with dense morphology, thereby enabling high initial coulombic efficiencies. In ether-based electrolytes, the Na metal surface exhibits the presence of a uniform solid electrolyte interphase layer, primarily characterized by favorable inorganic chemical components with close-packed structures. The full cell, utilizing a controlled electroplated sodium metal in ether-based electrolyte, provides capacity retention of 91.84% after 500 cycles at 2C current rate and delivers 86 mAh/g discharge capacity at 45C current rate, suggesting the potential to enable Na metal in the next generation of sodium-ion technologies with specifications close to practical requirements

Design principles for enabling an anode-free sodium all-solid-state battery

Anode-free batteries possess the optimal cell architecture due to their reduced weight, volume and cost. However, their implementation has been limited by unstable anode morphological changes and anode–liquid electrolyte interface reactions. Here we show that an electrochemically stable solid electrolyte and the application of stack pressure can solve these issues by enabling the deposition of dense sodium metal. Furthermore, an aluminium current collector is found to achieve intimate solid–solid contact with the solid electrolyte, which allows highly reversible sodium plating and stripping at both high areal capacities and current densities, previously unobtainable with conventional aluminium foil. A sodium anode-free all-solid-state battery full cell is demonstrated with stable cycling for several hundred cycles. This cell architecture serves as a future direction for other battery chemistries to enable low-cost, high-energy-density and fast-charging batteries

Evaluating Electrolyte–Anode Interface Stability in Sodium All-Solid-State Batteries

All-solid-state batteries have recently gained considerable attention due to their potential improvements in safety, energy density, and cycle-life compared to conventional liquid electrolyte batteries. Sodium all-solid-state batteries also offer the potential to eliminate costly materials containing lithium, nickel, and cobalt, making them ideal for emerging grid energy storage applications. However, significant work is required to understand the persisting limitations and long-term cyclability of Na all-solid-state-based batteries. In this work, we demonstrate the importance of careful solid electrolyte selection for use against an alloy anode in Na all-solid-state batteries. Three emerging solid electrolyte material classes were chosen for this study: the chloride Na2.25Y0.25Zr0.75Cl6, sulfide Na3PS4, and borohydride Na2(B10H10)0.5(B12H12)0.5. Focused ion beam scanning electron microscopy (FIB-SEM) imaging, X-ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS) were utilized to characterize the evolution of the anode–electrolyte interface upon electrochemical cycling. The obtained results revealed that the interface stability is determined by both the intrinsic electrochemical stability of the solid electrolyte and the passivating properties of the formed interfacial products. With appropriate material selection for stability at the respective anode and cathode interfaces, stable cycling performance can be achieved for Na all-solid-state batteries

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

Surveillance and treatment of primary hepatocellular carcinoma (aka. STOP HCC): protocol for a prospective cohort study of high-risk patients for HCC using GALAD-score.

Vietnam and Saudi Arabia have high disease burden of primary hepatocellular carcinoma (HCC). Early detection in asymptomatic patients at risk for HCC is a strategy to improve survival outcomes in HCC management. GALAD score, a serum-based panel, has demonstrated promising clinical utility in HCC management. However, in order to ascertain its potential role in the surveillance of the early detection of HCC, GALAD needs to be validated prospectively for clinical surveillance of HCC (i.e., phase IV biomarker validation study). Thus, we propose to conduct a phase IV biomarker validation study to prospectively survey a cohort of patients with advanced fibrosis or compensated cirrhosis, irrespective of etiologies, using semi-annual abdominal ultrasound and GALAD score for five years. We plan to recruit a cohort of 1,600 patients, male or female, with advanced fibrosis or cirrhosis (i.e., F3 or F4) and MELD ≤ 15, in Vietnam and Saudi Arabia (n = 800 each). Individuals with a liver mass ≥ 1 cm in diameter, elevated alpha-fetoprotein (AFP) (≥ 9 ng/mL), and/or elevated GALAD score (≥ -0.63) will be scanned with dynamic contrast-enhanced magnetic resonance imaging (MRI), and a diagnosis of HCC will be made by Liver Imaging Reporting and Data System (LiRADS) assessment (LiRADS-5). Additionally, those who do not exhibit abnormal imaging findings, elevated AFP titer, and/or elevated GALAD score will obtain a dynamic contrast-enhanced MRI annually for five years to assess for HCC. Only MRI nearest to the time of GALAD score measurement, ultrasound and/or AFP evaluation will be included in the diagnostic validation analysis. MRI will be replaced with an abdominal computed tomography scan when MRI results are poor due to patient conditions such as movement etc. Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced MRI will not be carried out in study sites in both countries. Bootstrap resampling technique will be used to account for repeated measures to estimate standard errors and confidence intervals. Additionally, we will use the Cox proportional hazards regression model with covariates tailored to the hypothesis under investigation for time-to-HCC data as predicted by time-varying biomarker data. The present work will evaluate the performance of GALAD score in early detection of liver cancer. Furthermore, by leveraging the prospective cohort, we will establish a biorepository of longitudinally collected biospecimens from patients with advanced fibrosis or cirrhosis to be used as a reference set for future research in early detection of HCC in the two countries. Name of the registry: ClinicalTrials.gov Registration date: 22 April 2022 Trial registration number: NCT05342350 URL of trial registry record