Cao  Hien Nguyen, K. S. Banh, N. M. A. Tran, T. H. A. Nguyen, C. H. Dang, V. D. Doan, T. K. C. Tran, V. Q. Hieu, and T. D. Nguyen, "Cyclodextrin modified with different groups to enhance the drug delivery efficiency of gold nanoparticles to treat cancer," Arabian Journal of Chemistry, vol. 16, no. 9, p. 105079, 2023

Trong nghiên cứu này, một phương pháp hai bước đã được sử dụng để tổng hợp Mono-6-(1,3-trimethylenediamine)-6-deoxy-β-cyclodextrin (TMACD), Chất này được dùng để chế tạo hạt nano vàng (AuNPs) bằng phương pháp tổng hợp có sự hỗ trợ của sóng siêu âm. Khả năng tải thuốc 5-FU được so sánh giữa ba dẫn xuất cyclodextrin, cụ thể (5-FU@AuNPs/CD), 5-FU@AuNPs/HPCD và 5-FU@AuNPs/TMACD.

Nguyễn Văn Hòa, Nghiên cứu tẩy trắng cao lanh bằng acid, Kỷ yếu hội thảo khoa học cấp khoa

Quá trình tẩy trắng cao lanh Bảo Lộc (chủ yếu là quá trình hòa tan sắt) bằng các đơn và đa acid đã được khảo sát trong nghiên cứu này. Kết quả phân tích XRD cho thấy thành phần khoáng là không thay đổi trong quá trình tẩy trắng. Hỗn hợp đa acid bao gồm AO + HCl và AO + SA cho hiệu quả tẩy trắng vượt trội so với các đơn acid thông thường. Nồng độ thích hợp của HCl hoặc AS bổ sung vào AO là 0,1 M; ở nồng độ cao hơn đều làm cho hiệu quả tách sắt giảm. Nhiệt độ là một yếu tố ảnh hưởng rất lớn đến khả năng tẩy trắng cao lanh, quá trình tẩy trắng xảy ra chậm ở nhiệt độ phòng nên để có hiệu quả tẩy trắng tương tự như ở 90 oC trong khoảng 3 giờ thì ở nhiệt độ phòng mất khoảng trên 18 ngày.

Hồ Thị Ngọc Sương, Ảnh hưởng của nhiệt độ nung tới hoạt tính quang xúc tác phân hủy phenol của vật liệu composite TiO2/SiO2,

Vật liệu TiO2-SiO2 được tổng hợp bằng phương pháp sol-gel với tiền chất ban đầu là titan n-butoxide và tetraethyl orthosilicate. Cấu trúc đặc trưng của vật liệu TiO2-SiO2 composite được xác định bởi phương pháp nhiễu xạ tia X (XRD), kính hiển vi điện tử quét (SEM) và đường đẳng nhiệt hấp phụ- giải hấp phụ N2 (BET). Tính chất quang xúc tác được đánh giá thông qua quá trình phân hủy phenol dưới ánh sáng khả kiến, sử dụng đèn compact 26 W. Xúc tác TiO2-SiO2 composite (Ti/Si là 95/5) tổng hợp đạt hiệu quả quang xúc tác cao nhất là 91,5% sau 4 h chiếu xạ. Mẫu đạt được ở điều kiện tổng hợp với tỉ lệ mol giữa titan n-butoxide: acetylacetone là 1:1, tỉ lệ khối lượng giữa titan n-butoxide: Polyethylene glycol là 1:0,05 và nhiệt độ nung 500 ºC

Nguyen Hoc Thang, Nguyen Van Phuc, Tran Thi Tu Nhi, Dang Xuan Cuong, Do Quang Minh. Novel polymer-based hydrogels of recent research in drug delivery for disease treatment related to SARS-CoV-2 virus. Express Polymer Letters, 2024.

Polymer-based hydrogels are hydrophilic polymer networks with a remarkable capacity to absorb substantial amounts of water and biological fluids, rendering them highly attractive for drug delivery applications. The COVID-19 pandemic has acted as a catalyst for research and innovation in the realm of polymer-based hydrogels for drug delivery, with a particular emphasis on antiviral therapeutics, vaccines, diagnostics, and precision delivery to the respiratory system. The distinctive attributes of hydrogels, such as their biocompatibility, customizable drug release profiles, and ease of functionalization, establish them as versatile platforms for the development of advanced drug delivery systems to combat not only COVID-19 but also a spectrum of other infectious diseases. This study is dedicated to scruti-nizing and evaluating the characteristics of polymer-based hydrogels employed in drug delivery for the treatment of diseases associated with the SARS-CoV-2 virus. Furthermore, the investigation introduces a novel classification system for polymer-based hydrogels deployed in drug delivery for SARS-CoV-2-related diseases. Additionally, the paper provides an up-to-date evaluation of the latest developed hydrogels utilized in drug delivery for the treatment of dis-eases linked to the SARS-CoV-2 virus, based on research conducted through the recent months of 2023.

Ngô Thanh An, Áp dụng biểu đồ thống kê đa biến Hotelling T² trong kiểm soát quá trình sản xuất, Tạp chí khoa học Đại học Công Thương, 2024

Biểu đồ thống kê đa biến là một công cụ phổ biến được áp dụng trong quản lý chất lượng để kiểm soát quá trình sản xuất. Trong bài báo này, biểu đồ thống kê đa biến Hotelling T² được sử dụng để đánh giá quá trình tuyển nổi chì - kẽm với dữ liệu tham khảo đã được công bố. Phương pháp xây dựng biểu đồ Hotelling T² được thể hiện qua từng giai đoạn. Kết quả các giá trị giới hạn kiểm soát và điểm ngoại lệ được xác định thông qua phương pháp thống kê Hotelling kết hợp với phương pháp phân tích thành phần chính PCA do phần mềm Minitab 21 thực hiện. Bên cạnh đó, các thông số chính gây ra điểm ngoại lệ cũng được phân tích bằng PCA và phương pháp phân tách T2 . Tương tự với biểu đồ thống kê đơn biến X, biểu đồ Hotelling T² cũng xác định “chiều cao lớp lỏng’’ và “giá trị pH” là hai thông số ảnh hưởng chính đến quá trình tuyển nổi. Tuy nhiên, số điểm ngoại lệ trên biểu đồ biểu đồ Hotelling T² ít hơn, thể hiện được sự tương quan của các thông số ảnh hưởng đến hiệu quả của quy trình. Qua đó cho thấy, nếu quá trình sản xuất có nhiều biến tác động và tương quan thì kiểm soát bằng biểu đồ đa biến Hotelling T² sẽ là công cụ hữu ích để đánh giá toàn diện hơn.

Nguyen Thanh Hoai Nam, Dang Phuc Truong, Truong Thien Vinh An, Quach Thi Thanh Huong, Nguyen Ngoc Kim Tuyen, Hoang An, Nguyen Duy Hai, Ninh Thi Tinh, Nguyen Le Khanh Linh, Nguyen Thi Truc Quynh, Tran Chi Lap, Nguyen Huu Hieu. Biological activity prospects of selenium-decorated graphene oxide composite by green synthesis using Sesbania sesban flower extract. Diamond and Related Materials, 2024.

In this work, the nanostructured composite of selenium and graphene oxide was synthesized using Sesbania sesban extract. Accordingly, the results showed a successful fabrication of the material, which involved the contribution of the phyto-compounds in the extract and graphene oxide as reducing and stabilizing agents. Moreover, the appearances of both nanoparticles and nanorods on the graphene oxide nanosheets were also observed without the occurrence of any interference. By applying the material to various microorganisms, the results were fruitful and provided insightful speculation. Specifically, both the antibacterial and antifungal activities revealed high performances, and the relative inhibition mechanism was generally discussed. Finally, the antioxidant and anti-inflammatory effects of the material were also assessed. In general, the results suggest the potential of the material as the smart alternative role in medical and pharmaceutical aspects

Nguyen Ngoc Kim Tuyen, Vo Khac Huy, Nguyen Huu Duy, Hoang An, Nguyen Thanh Hoai Nam, Nguyen Minh Dat, Quach Thi Thanh Huong, Nguyen Le Phuong Trang, Nguyen Do Phuong Anh, Lu Thi Mong Thy, Mai Thanh Phong, Nguyen Huu Hieu. Green synthesis of selenium nanorods using Muntingia calabura leaf extract: effect of pH on characterization and bioactivities. Waste and Biomass Valorization, 2023.

In this study, selenium nanomaterials (nano-Se) were synthesized via a biological route, in which the leaf extract of Muntigia calabura was efficiently utilized as not only a reducing agent but also a surfactant to stabilize the produced nanostructures. In detail, the effect of pH level on the shape and bioactivities of nano-Se was thoroughly investigated, which revealed the formation of selenium nanorods at pH 8 with uniform sizes of 30–50 nm in diameter and several micrometers in length, corresponding to the Se-pH8 sample. Besides, the material also exhibited excellent bactericidal rates against both Gram-negative and Gram-positive strains, while the cytotoxicity test using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay elucidated the notably low toxicity of Se-pH8 towards the normal HEK293 cells. Therefore, the obtained results show the great potential of the nano-Se material in multiple industrial applications, particularly in the medical and pharmaceutical sectors.

Nguyen Ngoc Kim Tuyen, Quach Thi Thanh Huong, Bui Thanh Duy, Nguyen Thanh Hoai Nam, Nguyen Duy Hai, Hoang An, Ninh Thi Tinh, Tran Nhat Khanh, Tran Le Hoai Nhi, Lam Thanh Ngan, Nguyen Huu Hieu. Selenium microparticles decorated graphene oxide via green synthesis using Psidium guajava leaves: preparation, characterization, and biological activities. New Journal of Chemistry, 2023.

An environmentally friendly method was used to synthesize selenium microparticles (SeMPs) by applying Psidium guajava leaf extracts as a reducing agent. In addition, in this study, SeMPs were combined with graphene oxide (Se/GO) via an ex situ method. The results of the phytochemical analysis of the Psidium guajava leaves revealed the presence of flavonoids, polyphenols, triterpenoids, and ascorbic acid. In addition, the results indicated that the SeMPs were spherical and uniformly distributed on graphene oxide (GO) sheets with an average diameter of about 475 nm. Moreover, the antioxidant activity was investigated with two free radical scavenging methods 2-diphenyl-1-picrylhydrazyl and 2,20-azino-bis(3- ethylbenzothiazoline-6-sulfonic acid) with yields of 63.34 and 90.9%, respectively. Additionally, the antibacterial performance of the resulting material, which showed a great inhibition performance against the Gram-positive strains of Staphylococcus aureus, Bacillus subtilis, and Limosilactobacillus fermentum, Gram-negative ones of Escherichia coli and Salmonella enterica, and the fungi strain of Candida albicanas, was investigated. Moreover, the anticancer activity was evaluated towards three cell lines, including liver cancer cells, lung cancer cells, and human embryonic kidney cells. The results revealed that the anticancer performance of the material achieved 90% with a Se/GO concentration of 256 mg mLÿ1. The anti-diabetic ability of the material toward the enzyme a-glucosides also showed high results with an inhibiting percentage of 100%, reaffirming the promising potential of the Se/GO materials in medical applications.

Lữ Thị Mộng Thy, Nghiên cứu sản xuất bột Matcha từ lá vối (Cleistocalyx operculatus) và ứng dụng bột matcha lá vối trong sản phẩm xà phòng, Trường Đại học Công thương TP.HCM, 2024

Mục tiêu của đề tài là nghiên cứu sản xuất bột “matcha” từ lá vối (Cleistocalyx Operculatus) và ứng dụng bột “matcha” lá vối trong phối liệu xà phòng.

Lữ Thị Mộng Thy, Nghiên cứu ảnh hưởng điều kiện sấy đến hàm lượng polyphenol, chlorophyll của lá vối (Cleistocalyx Operculatus), Tạp chí Công thương, 2024

Nội dung của báo cáo là khảo sát các điều kiện sấy trên 2 phương pháp sấy đối lưu nóng và sấy lạnh, đánh giá ảnh hưởng các điều kiện sấy đến hàm lượng polyphenol tổng, chlorophyll của lá vối (Cleistocalyx Operculatus). Qua kết quả khảo sát, phương pháp sấy lạnh với điều kiện sấy ở 50oC, thời gian 180 phút thu được bột lá vối có màu xanh thẫm, mịn và vẫn giữ mùi thơm lá vối. Kết quả phân tích bột lá vối sấy lạnh có độ ẩm thấp (5,73±0,01)%, hàm lượng polyphenol tổng và chlorophyll tổng lần lượt là 45,30±0,15 (mg/g) và 6,78±0,31 (mg/g).

Le Minh Huong, Nguyen Thanh Hoai Nam, Nguyen Tien Dat, Che Quang Cong, Lam Thanh Ngan, Hoang Thuy Kim Ngan, Hoang An, Le Tan Tai, Phan Nguyen Phu Hung, Huynh Khanh Duy, Nguyen Cong Anh Minh, Nguyen Duy Hai, Ninh Thi Tinh, Lu Thi Mong Thy, Nguyen Huu Hieu. Antibacterial mechanism of phyto-synthesized CuO-decorated ZnO nanostructure in relation to hydrogen peroxide generation under visible-light condition. Surfaces and Interfaces, 2023.

In this study, CuO-decorated ZnO (ZC) heterojunction nanocomposite was successfully green synthesized as a light-enhanced antibacterial material using Muntingia calabura leaf extract. Resultantly, it showed the formation of rice grain-shaped particles with 100 − 250 nm in length and 50 − 100 nm in width as shown through field emission-scanning electron microscopy images. Subsequently, the antibacterial activity of the ZC was evaluated against both Gram-negative and Gram-positive strains, in which the bactericidal properties of the material significantly increased upon being illuminated. The band structure of ZC nanocomposite reveals that the material generates free radicals and releases Zn2+ and Cu2+ ions to initiate the destruction of cell membranes. Besides, the ZC can also absorb light in the visible spectrum with a bandgap energy of 2.94 eV along with a feasible band structure that can facilitate the generation of free radicals as well as H2O2 concentration of 25 µM through a generation experiment within an oxygen-aerated aqueous media. Conclusively, the obtained results imply the great antibacterial capability for medical applications of green synthesized nanomaterials using biological plant extracts. Moreover, such results open up a new pathway to produce heterostructure through the use of plant extracts.

Nhat Tran Tan, Bleaching of red clay using Na2S2O4 and NaBH4 in acidic solution, Advances in Energy, Infrastructure and Environmental Research (ISBN: 978-604-357-239-1 ), 2023

Bleaching of red clay is carried out by reacting iron-containing clay with the system of two reducing agents Na2S2O4, and NaBH4, in an acidic environment. The treatment process is performed with the help of ultrasonic equipment, as well as mixing operations performed at high temperature. Several physical-chemical methods such as XRF, XRD, and FTIR were used to evaluate clay samples before and after treatment. The results showed effective iron-removal in red clay. Comparison of whiteness between the processed sample and the original sample is performed by measuring parameters in the CIE L*a*b* color-system. The analysis shows that the whiteness of the treated sample reached 78.72%, showing that the treated clay has clearly improved its whiteness, and can be applied in making high-end ceramic products that require the clay with high whiteness.

Nguyễn Hưng Thủy, Vật liệu composite trong sự phát triển bền vững kinh tế biển, Kỷ yếu hội thảo khoa học khoa công nghệ hóa học, 2024

Bài báo trình bày về vật liệu composite nền nhựa nhiệt rắn ứng dụng cho ngành hàng hải, đóng tàu, sửa chữa và khắc phục sự cố trên biển. Vật liệu composite nền nhựa nhiệt rắn cốt sợi FRP (fiber reinforced plastics) với tính ổn định bền lâu, nhẹ và dễ gia công và tính chất cơ lý hóa ưu việt rất thích hợp cho các vùng có khí hậu đặc thù ven biển. Việc áp dụng công nghệ composite cho các công trình ven biển, ngành hàng hải đánh bắt cá và du lịch biển đảo cần có các chính sách hỗ trợ về đào tạo, đầu tư xây dựng và chuyển giao công nghệ vật liệu này

Bùi Thu Hà, Nghiên cứu tổng hợp xúc tác LaNiO3 cho phản ứng hydro hóa p-nitrophenol, Kỷ yếu hội thảo khoa học - Khoa Công nghệ Hóa học, 2024

Trong nghiên cứu này, xúc tác LaNiO3 được tổng hợp bằng phương pháp đồng kết tủa với điều kiện nung 650 oC trong 2 h, sau đó được khử trong dòng hydrogen với nhiệt độ và thời gian khác nhau. Xúc tác LaNiO3 tốt nhất được tổng hợp với điều kiện khử ở nhiệt độ 550 oC trong 1 h, kích thước hạt 21,5 nm, thuộc dạng mao quản trung bình, diện tích bề mặt riêng 12,6 m2 /g và đường kính lỗ xốp 24 Å. Mẫu xúc tác LaNiO3 có hoạt tính tốt nhất đối với phản ứng hydro hóa p-nitrophenol (PNP) trong pha lỏng được khảo sát ở nhiệt độ phòng, với tác nhân khử NaBH4 đã xử lý 100% PNP chỉ sau 5 phút.

Hanh Ngoc Thi Le, Nguyen Huynh Phuong Uyen, Hung Duong Phuoc, Kiyoshi Imamura, Masakazu Furuta, Yasuaki Maeda. Preparation of high-quality oil from vegetable oil with high-free fatty acid (FFA) content using an ammonia/methanol solution. Journal of Oleo Science, 2023.

There are significant concerns regarding the quality of vegetable oils in the food and biofuel industries. In this study, we explored the preparation of high- quality oil from high-free fatty acid (FFA) vegetable oil using an ammonia/MeOH solvent as an alkali base. Among the six tested solvents, MeOH was the most suitable for the separation of the oil and FFAs. Among the three alkali bases, ammonia enhanced the miscibility of FFAs in MeOH by forming ammonium salts. The amounts of FFAs in the upper layer and oil in the lower layer were positively correlated (r = 0.9348 and 0.9617, respectively) with MeOH. With increasing MeOH concentration, the amount of oil in the lower layer increased along with the FFAs in the upper layer. Using the molar ratio of ammonia to FFA 1:1 and the ratio (v/w) of MeOH to oil 4:3, 91.6% FFAs and 97.8% oil in the upper and lower layers, respectively, were produced from 50% FFA oil. Using a relational expression of FFAs and oil in the upper layer, 97.1% FFAs and 99.6% oil in each layer was obtained from 10% FFA oil. The oil in the lower layer was further purified by extraction with MeOH. This method is easy and efficient for the separation and purification of oil, accompanied by the reuse of reagents with almost no loss of raw materials.

Biểu đồ thống kê đa biến là một công cụ phổ biến được áp dụng trong quản lý chất lượng để kiểm soát quá trình sản xuất. Trong bài báo này, biểu đồ thống kê đa biến Hotelling T² được sử dụng để đánh giá quá trình tuyển nổi chì - kẽm với dữ liệu tham khảo đã được công bố. Phương pháp xây dựng biểu đồ Hotelling T² được thể hiện qua từng giai đoạn. Kết quả các giá trị giới hạn kiểm soát và điểm ngoại lệ được xác định thông qua phương pháp thống kê Hotelling kết hợp với phương pháp phân tích thành phần chính PCA do phần mềm Minitab 21 thực hiện. Bên cạnh đó, các thông số chính gây ra điểm ngoại lệ cũng được phân tích bằng PCA và phương pháp phân tách T2 . Tương tự với biểu đồ thống kê đơn biến X, biểu đồ Hotelling T² cũng xác định “chiều cao lớp lỏng’’ và “giá trị pH” là hai thông số ảnh hưởng chính đến quá trình tuyển nổi. Tuy nhiên, số điểm ngoại lệ trên biểu đồ biểu đồ Hotelling T² ít hơn, thể hiện được sự tương quan của các thông số ảnh hưởng đến hiệu quả của quy trình. Qua đó cho thấy, nếu quá trình sản xuất có nhiều biến tác động và tương quan thì kiểm soát bằng biểu đồ đa biến Hotelling T² sẽ là công cụ hữu ích để đánh giá toàn diện hơn.

Bùi Thu Hải, Võ Minh Tâm, Võ Gia Huy, Nguyễn Cao Duy, Trần Thanh Tín, Lê Thị Thanh Ngân, Trần Nguyễn An Sa. Khảo sát các yếu tố ảnh hưởng đến quy trình chưng cất và xác định thành phần hóa học, hoạt tính kháng khuẩn của tinh dầu từ rễ và lá cây cách (Premna serratifolia L.). Tạp chí Đại học Đồng Tháp, 2024.

Nghiên cứu này nhằm mục đích khảo sát và đánh giá tác động của các yếu tố như thời gian, nồng độ NaCl và thể tích dung dịch NaCl đối với quy trình chưng cất tinh dầu từ lá và rễ của cây cách thu hái tại khu vực Sa đéc-Đồng Tháp. Sử dụng bộ định lượng tinh dầu theo Dược điển Việt Nam V, các thông số phù hợp để tách tinh dầu trong lá và rễ cách lần lượt là: thời gian 30-45 phút, nồng độ NaCl 5-10%, và tỉ lệ dung môi/ nguyên liệu là 5:3 đối với lá và 2:1 đối với rễ cây cách. Kết quả phân tích bằng phương pháp GC/MS cho thấy các thành phần chính trong tinh dầu lá cây cách bao gồm 1-octene-3-ol (19,01%), phytol (23,46%), linalool (16,59%). Thành phần trong tinh dầu từ rễ cây cách chủ yếu thuộc nhóm sesquiterpene (humulenol-II, α-selinene, ageratriol) và sesquiterpenoid (caryophyllene oxide, spathulenol). Ngoài ra, tinh dầu từ lá và rễ của cây cách đều thể hiện khả năng kháng mạnh đến vừa đối với vi khuẩn Staphylococcus aureus và có khả năng kháng nấm Candida albicans ở mức độ vừa, và kháng yếu đối với vi khuẩn Escherichia coli.

 Ba Long Do, Thu Ha Bui, Thanh Gia-Thien Ho, Nhat Linh Duong, Van Minh Nguyen, Trung Dang-Bao, Tri Nguyen, Phan Hong Phuong, Green synthesis of nano-silver and its antibacterial activity against methicillin-resistant Staphylococcus aureus, Journal of Saudi Chemical Society, 2023.

The current study presents a cost-effective and environmentally friendly technique for synthesizing silver nanoparticles (AgNPs) using Citrus maxima peel (CMP) extract as a reducing ans stablizing agent. UV–Vis Spectroscopy results confirmed the formation of AgNPs in the 400–500 nm wavelength range. The Powder X-ray diffraction (PXRD) and high-resolution transmission electron microscopy (HRTEM) results at the optimized synthesis conditions revealed highly crystalline AgNPs (face-centered cubic structure) with particles the size of 10–20 nm. The Fourier transform infrared spectroscopy (FT-IR) revealed the presence of flavonoids, terpenoids, phenolics, and glycosides in the phytochemical compositions of the CMP extract, which can serve as reducing agents for the formation of the spherical AgNPs. Minimum inhibitory concentration (MIC) values of 8.27 µg/mL, minimum bactericidal concentration (MBC) values of 16.54 µg/mL, and an inhibition zone of 11.7 mm were indicative of the potent antibacterial activity of as-prepared AgNPs against MRSA. The findings suggest biogenic silver nanoparticles could be an effective antimicrobial agent against nosocomial infections.

An environmentally friendly method was used to synthesize selenium microparticles (SeMPs) by applying Psidium guajava leaf extracts as a reducing agent. In addition, in this study, SeMPs were combined with graphene oxide (Se/GO) via an ex situ method. The results of the phytochemical analysis of the Psidium guajava leaves revealed the presence of flavonoids, polyphenols, triterpenoids, and ascorbic acid. In addition, the results indicated that the SeMPs were spherical and uniformly distributed on graphene oxide (GO) sheets with an average diameter of about 475 nm. Moreover, the antioxidant activity was investigated with two free radical scavenging methods 2-diphenyl-1-picrylhydrazyl and 2,20-azino-bis(3- ethylbenzothiazoline-6-sulfonic acid) with yields of 63.34 and 90.9%, respectively. Additionally, the antibacterial performance of the resulting material, which showed a great inhibition performance against the Gram-positive strains of Staphylococcus aureus, Bacillus subtilis, and Limosilactobacillus fermentum, Gram-negative ones of Escherichia coli and Salmonella enterica, and the fungi strain of Candida albicanas, was investigated. Moreover, the anticancer activity was evaluated towards three cell lines, including liver cancer cells, lung cancer cells, and human embryonic kidney cells. The results revealed that the anticancer performance of the material achieved 90% with a Se/GO concentration of 256 mg mLÿ1. The anti-diabetic ability of the material toward the enzyme a-glucosides also showed high results with an inhibiting percentage of 100%, reaffirming the promising potential of the Se/GO materials in medical applications.

The valorization of shrimp wastes to develop advanced materials brings economic and environmental advantages. This paper presents a facile and eco-friendly synthesis of shrimp chitosan-derived carbon (CCS) and CCS/NiO@Ni(OH)2(CSSN) aerogel nanocomposite for supercapacitor application, in which NiO and Ni(OH)2 nanoparticles were tightly attached to the porous surface of CCS aerogel. As a result, CCSN- 300 aerogel carbonized at 300 0C has high porosity and electrical conductivity and demonstrates its potential as an active electrode material for supercapacitors. The CCSN-300 aerogel material electrode exhibits a high capacitance of 316 mAh.g-1 at 1.0 A.g-1. Furthermore, the CCS//CCSN-300 device had a capacitance of 209 F.g-1 at 1.0 A.g-1 and over 84% remaining after the 10,000 cycles. Moreover, it has a high energy density of 65 Wh.kg-1 at a power density of 1500 W.kg-1. The results demonstrate that chitosan-derived carbon composites hold great promise in high application efficiency for energy storage.

Spent coffee grounds (SCGs), the main by-product in the coffee industry, were proposed as a starting material to fabricate both ultraviolet (UV) shielding material and nanocomposite based on polyvinyl alcohol (PVA). The extract using low SCGs concentration (0.25 wt%) contains a significant amount of UV-absorbing substances. The UV shielding film from 5 wt% PVA solution and SCGs extract (1 g SCGs/200 ml water) could shield most of the radiation in UV-B and UV-C regions and maintain 63% transmittance at 550 nm. The SCGs after washing were ball milled and the ultrasonic liquid processor was applied to synthesize SCGs nanoparticle. The effects of ultrasonic amplitude and hexadecyltrimethylammonium bromide (CTAB) on the particle’s hydrodynamic diameter were investigated. The particle’s size of 148 nm was obtained with 50% ultrasonic amplitude. Fourier-transformed infrared spectroscopy (FTIR) results confirmed the presence of hydroxyl groups (–OH) on the SCGs-based nanoparticle’s surface. The tensile strength of PVA-SCGs nanocomposite was significantly improved. However, the presence of CTAB in the nano solution could not show a better tensile result. The organic compounds contained in the SCGs extract and even in the nano SCGs solution could enhance thermal oxidation stability for both UV shielding films and nanocomposites.

 We present the in situ synthesis of silver nanoparticles (AgNPs) through ionotropic gelation utilizing the biodegradable saccharides lactose (Lac) and alginate (Alg). The lactose reduced silver ions to form AgNPs. The crystallite structure of the nanocomposite AgNPs@Lac/Alg, with a mean size of 4–6 nm, was confirmed by analytical techniques. The nanocomposite exhibited high catalytic performance in degrading the pollutants methyl orange and rhodamine B. The antibacterial activity of the nanocomposite is pH-dependent, related to the alterations in surface properties of the nanocomposite at different pH values. At pH 6, the nanocomposite demonstrated the highest antibacterial activity. These findings suggest that this nanocomposite has the potential to be tailored for specific applications in environmental and medicinal treatments, making it a highly promising material.

In the study, rGO was used as an electron mediator to establish WO3@rGO@AgI (WrGA) ternary heterojunction to apply for degradation of Amoxil upon excitation of visible light. Various characterization methods and technologies, such as XRD, SEM, TEM, UV–Vis and PL, and trapping experiments of active species were applied to determine charge separation as well as degradation mechanism. The achieved data showed that both WO3 and

AgI in the synthesized WrGA had suitable band gap energies to absorb provided visible light for e􀀀 jumping from valence band (VB) to conduction band (CB) leaving h+ at the VB. Then, the rGO effectively acted as e􀀀 mediator to promote Z scheme mechanism for its migration from the WO3 CB to the AgI VB to prevent charge recombination in WO3 as well as AgI. The charge separation via Z scheme mechanism also maintained significant charges

(e􀀀 at AgI CB and h+ at WO3 VB) with high redox potentials for photocatalysis. Therefore, the Amoxil degradation efficiency of the WrGA was 24% higher than that of the WA (without rGO). Finally, the recycling tests showed novel stability and recycling potential of the synthesized WrGA opening new era for its application in practical system for degradation of organic pollutants.

A facial strategy for the synthesis of hierarchical binary core-branch carbon microspheres (CMS)@α-Fe2O3 is presented. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), and Brunauer–Emmett–Teller (BET) were used to characterize the structural and morphological properties of the products. XRD diffraction analysis of CMS@α-Fe2O3 reveals the highly crystalline nature of α-Fe2O3 in the hierarchical binary core-branch CMS@α-Fe2O3 nanocomposite. Morphological analyses show that the α-Fe2O3 shell layer grew onto the surface of CMS to form nanoscale heterointerfaces in the core-branch structure, demonstrating the effectiveness of the synthesized route. More importantly, CMS@α-Fe2O3 demonstrated superior electrochemical behavior to CMS. The enhanced CMS@α-Fe2O3 electrochemical performance can be attributed to its large specific surface area, which allows for the rapid transfer of electrons into the electrode during the redox process. 

 In this work, a novel Ag-incorporated 3D flower-like porous Fe3O4 magnetic microstructure (Fe3O4/Ag-FM) was effectively prepared via a quasi-reverse emulsion soft template approach and reductive deposition of Ag nanoparticles. The synthesized Fe3O4/Ag-FM material was applied for the electrochemical sensing and catalytic reduction of 4-nitrophenol (4-NP). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques were used to determine the electrochemical sensing ability of the synthesized material. Results showed that the fabricated Fe3O4/Ag-FM-based electrode detected a low concentration of 4-NP (0.093 μM) and a linear response in the range of 1.0–15 μM. Furthermore, the Fe3O4/Ag-FM material also exhibited excellent reduction ability towards 4-NP with the assistance of NaBH4. This is because a synergistic effect formed between Ag nanoparticles and flower-like Fe3O4 magnetic microstructure enhanced the catalytic activity towards electrochemical detection and reduction of 4-NP. Overall, the current strategy could help design and synthesize future catalysts that can work as sensors and catalysts.

An increasing interest in nanocomposites prepared from agricultural/industrial byproducts has been paid for environmental remediation, especially in water treatment. This study reports the facile preparation of a low-cost magnetic biocomposite of magnetic Fe3O4 nanoparticles (NPs) incorporated with biopolymers extracted from durian husk, called bp-Fe3O4 and examined in the removal of methylene blue (MB) dye. Here, Fe2O3 NPs were first recovered from red mud waste and then converted to magnetic nanostructured Fe3O4 using a one-pot process via carbon combustion. The bp-Fe3O4 inherited the characteristics of each constituent component, while showing slightly higher saturation magnetization than the bare Fe3O4 NPs (19.84 and 18.66 emu/g, respectively), allowing for easy separation from the aqueous solution using a suitable magnet. The MB adsorption on bp-Fe3O4 reached an equilibrium state within 60 min reaction and achieved .90% of removal (at 50 mg/L MB) at an optimal pH range of 6–8. The effective adsorption of MB dye was attributed to both the hydroxylated-Fe3O4 NPs and biopolymers. The material showed excellent reusability tested up to the seventh MB adsorption cycle (decreased by ,2% of adsorption efficiency). Overall, the outstanding magnetic properties and low-cost bp-Fe3O4 rendered them easily manipulated and separated, and reusable for water/wastewater treatment of MB dye.

Low-cost adsorbents derived from agricultural by-products incorporated magnetic nanoparticles (NPs) are promising for wastewater treatment. They are always preferred due to their great performance and easy separation. This study reports cobalt superparamagnetic (CoFe2O4) nanoparticles (NPs) incorporated with triethanolamine (TEA) based surfactants from cashew nut shell liquid, namely TEA-CoFe2O4, for the removal of chromium (VI) ions from aqueous solutions. To have detailed characteristics of the morphology and structural properties, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry (VSM) were employed. The fabricated TEA-CoFe2O4 particles exhibit soft and superparamagnetic properties, which make the nanoparticles easily recycled by using a magnet. Chromate adsorption on the TEA-CoFe2O4 nanomaterials reached an optimal efficiency of 84.3% at pH = 3 with the initial adsorbent dose of 10 g/L and chromium (VI) concentration of 40 mg/L. The TEA-CoFe2O4 nanoparticles can maintain the effective adsorption of chromium (VI) ion (by 29% of efficiency loss) and retain the magnetic separation using a magnet up to three cycles of the regeneration, which promise a high potential of this low-cost adsorbent for long-term treatment of heavy metal ions from polluted waters.

This study presented two approaches to synthesize bio-surfactants using cashew nut shell liquid (CNSL), an abundant natural resource. The different preparation conditions were investigated and optimized to obtain the surfactant products of maximum weight and desired characteristics. The anionic sodium anacardate surfactant was recommended to be synthesized by carrying out the saponification reaction between CNSL and NaOH in a weight ratio of 1 : 2 at 85°C for 1 h. Meanwhile, the amphoteric triethanolamine anacardate surfactant was prepared using the neutralization reaction between CNSL and triethanolamine in a weight ratio of 1 : 1 at 70oC in 3 h. All the surfactant products were examined by Fourier transform infrared spectroscopy to confirm their chemical structure. In addition, characteristic properties of the surfactants including solubility, emulsifying ability and stability, foaming ability and stability, surface tension, and skin irritation were also explored. Both the sodium anacardate and triethanolamine anacardate demonstrated

comparable foaming capacity and surface tension with commercial surfactants. In an attempt, sodium anacardate was utilized to make industrial soap and shoe polish of good sensory quality.

In recent years, essential oils extracted from different plant species have become increasingly popular in the production of pharmaceuticals, cosmetics, and foods. The essential oil from orange (Citrus sinensis) is important in large-scale applications due to its antibacterial, antioxidant activities, and pleasant aroma. In this study, factors affecting the production of orange essential oil on a distillation device with an operating capacity of 50 L/batch, including the ratio of material to water, temperature, and time distillation, have been surveyed. Through the survey, it was found that the raw materials were pureed, the materials: water ratio was 1:3 g/g, the water heating temperature was 130 °C, and the distillation time was 140 min. The yield of the essential oil was 1.8 mL/g with compounds limonene accounting for 98%, α-Pinene (0.655–0.734%), and β-Pinene (1.114 and 1.163%) by the GC-MS method. The review also found that the hydrodistillation equipment was designed to be suitable for the semi-industrial scales of orange essential oil due to its stable yield and volatile compounds contained in the essential oil.

The gray abalone mushroom is a rich source of amino acids and carbohydrate compounds, with some biological activities and antioxidants. Nowadays, the variety of food additives on the market such as sodium glutamate (E621), sodium guanylate (E627), or sodium insonate (E631), could probably cause negative effects for people’s health. This study used gray abalone mushrooms to create naturally derived seasoning products without using flavor enhancers and synthetic compounds. The gray abalone mushroom was pretreated and dried at 60°C until attaining the moisture content of <5%, while the biological activity and antioxidant values were kept optimal. The mixture ingredients, including 5% abalone mushroom powder, 2% baby cornstarch, and other seasoning ingredients, were uniformly ground. The based-gray abalone mushroom powder that was packed in PE with the moisture content below 3% displayed stability in terms of quality throughout 90 days. Gray abalone mushroom seasoning powder contributed to creating safe, natural products as well as improving consumers’ health.

The aim of this study is to investigate the impact of time and temperature of the heat pump drying process of soursop slices at different levels on moisture content and total polyphenol content (TPC). Twelve types of classical kinetic models have been used in this work to describe the suitability of experimental data with models. The conformity is assessed based on statistical values (e.g., coefficient of determination (R2), Chi–square value (X2), etc.). The loss of moisture in the material is described in accordance with Fick’s diffusion law. Value of moisture rate (MR), and effective moisture diffusivities (Deff) have been identified. Experimental results show that MR value depends on the time and drying temperature, Deff increases when increasing the drying temperature from 20–50 °C with values of 1.24 × 10−9, 1.85 × 10−8, 7.69 × 10−8, and 5.54 × 10−7 m/s2. The Singh et al. model is the best option to describe the moisture of the sliced soursop drying process at 30 °C (R2 = 0.97815). The largest TPC decomposition occurs at a temperature of 50 °C. The ability to decompose TPC is proportional to the drying temperature. The TPC decomposition dynamic model follows a first–order reaction when drying at 20 °C with a determinant coefficient R2 = 0.9693.

Using mango purée from overripe mangoes to produce powders helped to solve agricultural product stagnation. The research investigates the effect of thickening additives, convection drying, and heat pump drying on bioactive compounds such as total phenolic content (TPC), total flavonoid content (TFC), color, and solubility of the final product. The obtained results showed that the mixture (gum arabic and maltodextrin in the ratio 50:50 w/w) at a concentration of 15% gave a good quality powder texture when dried by hot air convection at 55°C with TPC (21.24 ± 1.58 mg GAE/g dry weight [DW]) and TFC (0.34 ± 0.02 mg QE/g DW), respectively. In addition, the product has a high solubility of 64.35%, with the highest pass-through point of 17.11.

Polymer-based hydrogels are hydrophilic polymer networks with crosslinks widely applied for drug delivery applications because of their ability to hold large amounts of water and biological fluids and control drug release based on their unique physicochemical properties and biocompatibility. Current trends in the development of hydrogel drug delivery systems involve the release of drugs in response to specific triggers such as pH, temperature, or enzymes for targeted drug delivery and to reduce the potential for systemic toxicity. In addition, developing injectable hydrogel formulations that are easily used and sustain drug release during this extended time is a growing interest. Another emerging trend in hydrogel drug delivery is the synthesis of nano hydrogels and other functional substances for improving targeted drug loading and release efficacy. Following these development trends, advanced hydrogels possessing mechanically improved properties, controlled release rates, and biocompatibility is developing as a focus of the field. More complex drug delivery systems such as multi-drug delivery and combination therapies will be developed based on these advancements. In addition, polymer-based hydrogels are gaining increasing attention in personalized medicine because of their ability to be tailored to a specific patient, for example, drug release rates, drug combinations, target-specific drug delivery, improvement of disease treatment effectiveness, and healthcare cost reduction. Overall, hydrogel application is advancing rapidly, towards more efficient and effective drug delivery systems in the future.

Herein we report a method for the synthesis of 2-arylthiochromenones via a sulfuration of 2’-chlorochalcones. The chalcones could be prepared in advance or in situ obtained from 2’-chloroacetophenones and aromatic aldehydes. The conditions were tolerant of functionalities including chloro, fluoro, methylthio, phenoxy, and trifluoromethyl groups. 2-Heteroaryl thiochromenones could also be obtained in moderate yields. Our method appears to be a simple, general tactic to afford 2-aryl thiochromenones from commercial starting materials

In the study, rGO was used as an electron mediator to establish WO3@rGO@AgI (WrGA) ternary heterojunction to apply for degradation of Amoxil upon excitation of visible light. Various characterization methods and technologies, such as XRD, SEM, TEM, UV–Vis and PL, and trapping experiments of active species were applied to determine charge separation as well as degradation mechanism. The achieved data showed that both WO3 and AgI in the synthesized WrGA had suitable band gap energies to absorb provided visible light for e􀀀 jumping from valence band (VB) to conduction band (CB) leaving h+ at the VB. Then, the rGO effectively acted as e􀀀 mediator to promote Z scheme mechanism for its migration from the WO3 CB to the AgI VB to prevent charge recombination in WO3 as well as AgI. The charge separation via Z scheme mechanism also maintained significant charges (e􀀀 at AgI CB and h+ at WO3 VB) with high redox potentials for photocatalysis. Therefore, the Amoxil degradation efficiency of the WrGA was 24% higher than that of the WA (without rGO). Finally, the recycling tests showed novel stability and recycling potential of the synthesized WrGA opening new era for its application in practical system for degradation of organic pollutants.

In this research, ZnO/GO nanocomposites were successfully synthesized by a simple hydrothermal method using graphene oxide (GO) and zinc acetate dihydrate (Zn(CH3COO)2.2H2O) as the reactants. The effect of the hydrothermal reaction time on the structure and optical property of the ZnO/GO was systematically investigated. The structure, morphology and chemical composition of the samples were measured by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) and Raman and Fourier transform infrared (FTIR) spectroscopy, while the optical properties were measured using photoluminescence spectroscopy. The synthesized products consisted of large quantities of one-dimensional (1D) ZnO nanorods (NRs), which were dispersed uniformly on the GO surface. The XRD and Raman results reveal that the ZnO NRs in the fabricated samples had a hexagonal wurtzite structure with high crystalline quality. The FESEM and TEM images reveal that ZnO NRs with an average diameter in the range of ~85–270 nm and length in the range of ~0.3–6 µm were covered with GO sheets. Additionally, it was found that the crystallographic orientation of ZnO NRs was dependent not only on the hydrothermal reaction time but also on the presence of GO in the nanocomposites. However, the addition of GO did not affect the stoichiometric ratio and the crystal structure of ZnO NRs. The room-temperature PL results indicated that, compared to those of pure ZnO, the luminescence of the GO/ZnO nanocomposites was suppressed and shifted towards a higher wavelength (red shift), which was attributed to the incorporation of ZnO NRs within the GO matrix and the formation of a C-O-Zn chemical bond in the nanocomposites. The hydrothermal technique is considered one of the best routes due to its low cost, high growth rates, low-temperature synthesis, controllable crystallographic orientation, particle size, as well as morphology.

In this research, 2D-MoS2/rGO nanocomposites were successfully synthesized by a facile hydrothermal method using graphene oxide (GO), sodium molybdate (Na2MoO4) and thiourea (CH4N2S) as the reactants. The effect of hydrothermal temperature (180–240 °C) on structure and optical properties of the MoS2/rGO have been systematically investigated. The study of chemical composition, structural and morphological properties was performed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS) and Raman spectroscopy, while the optical properties were measured using photoluminescence spectroscopy. The FESEM and HRTEM results revealed that the ultrathin MoS2 nanosheets with thickness in the range of ~6–13 nm (~6–8 layers) and average lateral size of ~130–330 nm were uniformly dispersed on the GO surface. Both the XRD and Raman analyses confirm that the MoS2 sheets in all prepared samples have a hexagonal phase structure (2H-MoS2). By increasing hydrothermal temperature, the characteristic diffraction peak (002) of 2H-MoS2 phase (at 2θ ≈ 14.2–14.5o) becomes sharper and its intensity gradually increases, thereby showing a very strong preferential orientation and better crystal quality. The estimated optical band gap for MoS2/rGO is achieved in the range of ~1.56–2.38 eV and it seems to be controlled by adjusting the synthesis temperature. Our work underscores the principle that controlling hydrothermal reaction temperature may constitute a generic strategy for modifying microstructure and engineering the optical bandgap of these semiconductor 2D nanocrystals, which opens the possibility of its use in electronic applications

Polymer-based hydrogels are hydrophilic polymer networks with crosslinks widely applied for drug delivery applications because of their ability to hold large amounts of water and biological fluids and control drug release based on their unique physicochemical properties and biocompatibility. Current  trends in the development of hydrogel drug delivery systems involve the release of drugs in response to specific triggers such as pH, temperature, or enzymes for targeted drug delivery and to reduce the potential for systemic toxicity. In addition, developing injectable hydrogel formulations that are easily used and sustain drug release during this extended time is a growing interest. Another emerging trend in hydrogel drug delivery is the synthesis of nano hydrogels and other functional substances for improving targeted drug loading and release efficacy. Following these development trends, advanced hydrogels possessing mechanically improved properties, controlled release rates, and biocompatibility is developing as a focus of the field. More complex drug delivery systems such as multi-drug delivery and combination therapies will be developed based on these advancements. In addition, polymer-based hydrogels are gaining increasing attention in personalized medicine because of their ability to be tailored to a specific patient, for example, drug release rates, drug combinations, target-specific drug delivery, improvement of disease treatment effectiveness, and healthcare cost reduction. Overall, hydrogel application is advancing rapidly, towards more efficient and effective drug delivery systems in the future.

A new depsidone, parmoferone A (1), together with three known compounds, parmosidone K (2), albifolione (3), and 4-chloroorcinol (4) were isolated from the lichen Parmotrema cristiferum (Taylor) Hale (Parmeliaceae). The structures of isolated compounds were identified from its spectroscopic data and by comparison with the literature. Compounds 1-4 were evaluated for alpha-glucosidase inhibition. Compound 1 was determined to be a potent non-competitive inhibitor against alpha-glucosidase with an IC50 value of 18.1 μM.

In this work, a novel Ag-incorporated 3D flower-like porous Fe3O4 magnetic microstructure (Fe3O4/Ag-FM) was effectively prepared via a quasi-reverse emulsion soft template approach and reductive deposition of Ag nanoparticles. The synthesized Fe3O4/Ag-FM material was applied for the electrochemical sensing and catalytic reduction of 4-nitrophenol (4-NP). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques were used to determine the electrochemical sensing ability of the synthesized material. Results showed that the fabricated Fe3O4/Ag-FM-based electrode detected a low concentration of 4-NP (0.093 μM) and a linear response in the range of 1.0–15 μM. Furthermore, the Fe3O4/Ag-FM material also exhibited excellent reduction ability towards 4-NP with the assistance of NaBH4. This is because a synergistic effect formed between Ag nanoparticles and flower-like Fe3O4 magnetic microstructure enhanced the catalytic activity towards electrochemical detection and reduction of 4-NP. Overall, the current strategy could help design and synthesize future catalysts that can work as sensors and catalysts.

BACKGROUND: The surfactant-assisted extraction of essential oils from Melaleuca alternifolia foliage, also known as tea tree oil (TTO), was systematically studied with the design of experiments (DoE) aiming to improve the extraction of TTO. Specifically, the optimal parameters of hydrodistillation process were obtained with the response surface methodology (RSM) based on a central composite design (CCD). RESULTS: The concept of enhanced TTO extraction with the renewable nonionic Triton CG-110  urfactant was proven. An opti- mal extraction yield of TTO was predicted by the RSM model at 6.71 wt% under the following conditions: (i) 597 mg L−1 Triton CG-110 as liquid extractant, (ii) a ratio of liquid  tractant/desiccated leaf at 25.4 mL g−1, and (iii) 140 min for the extraction time. The presence of 650  g L−1 Triton CG-110 in the extractant could increase the extraction rate of TTO by 17.5%, compared to  hat without surfactant. The forecast of the DPPH antioxidant activity of TTO by RSM was in good accordance  ith the mea- sured values. Various microemulsion formulations of TTO with Triton CG-110 were  eveloped and reported.

Bài báo tập trung đưa ra quy trình tính toán thiết kế thiết bị truyền nhiệt phổ biến (dạng ống xoắn và vỏ bọc) và mô phỏng quá trình tính toán thiết kế trên phần mềm MATLAB. Nhiệt độ dòng nóng (chất tải nhiệt nóng), nhiệt độ dòng lạnh (chất tải nhiệt lạnh), loại chất tải nhiệt, lưu lượng dòng và loại thiết bị truyền nhiệt là những yếu tố quan trọng ảnh hưởng rất lớn đến kết quả tính toán. Mô phỏng tính toán thiết kế thiết bị truyền nhiệt giúp tính toán hàng trăm phép tính khi có sự thay đổi của một thông số bất kỳ

Trong vài năm qua, phương pháp phân tích thành phần chính Kernel - Kernel Principal Component Analysis (KPCA) được ứng dụng trong kiểm soát quá trình trong sản xuất để phát hiện lỗi sản phẩm. Đây là phương pháp có độ tin cậy cao và đang dần được triển khai rộng rãi tìm lỗi cấu trúc sản phẩm. Trong bài báo này, chúng tôi kết hợp đồng thời KPCA và đo khoảng cách Mahalanobis (MD) để xác định các cấu trúc bất thường trên các mẫu đĩa silicon. Độ đồng đều của bề dày đĩa sẽ được phân tích và tìm những vị trí lỗi dựa trên khác biệt độ dày của nó. Thông qua ứng dụng Python, đã phát hiện điểm bất thường  (outlier). Khoảng cách Mahalanobis chỉ ra sự biến đổi không gian mới bằng cách cho chạy KPCA qua các hàm khác nhau như Linear, Polynomial, Radial Basic Function (RBF), Sigmoid… Dữ liệu được tìm thấy, so sánh các MD khi tìm nghiệm qua các hàm này sẽ được kết quả tối ưu.

This study gave a new method to synthesize 2-arylquinoxalines from o-phenylenediamines and aryl methyl ketones. The reaction occurred via molecular iodinepromoted direct C(sp3)-H bond functionalization of aryl methyl ketones under transition metal-free conditions. The utilities of this study are the (1) direct Csp3-H bond functionalization, (2) inexpensive and abundant iodine source, (3) transition metal-catalyst free, and (4) different synthesis of 2-arylquinoxalines from common materials.

Bê tông tro bay hàm lượng cao (HVFC) được nghiên cứu trong những năm gần đây để giải quyết các vấn đề về ô nhiễm tro thải nhiệt điện và các vấn đề môi trường do ngành công nghiệp sản xuất xi măng gây ra. Nghiên cứu này tiến hành tạo mẫu cấp phối bê tông với hàm lượng tro bay 70% thay thế chất kết dính thủy lực xi măng. Sự bổ sung phụ gia vôi và Silica Fume (SF) đã có những cải thiện đáng kể về đặc tính kỹ thuật của sản phẩm so với các mẫu HVFC đã công bố trước đó. Các đặc tính kỹ thuật như cường độ nén, cường độ uốn, cường độ chẻ bửa, độ hút nước được đánh giá theo các tiêu chuẩn Việt Nam (TCVN) đang được áp dụng đối với bê tông thương mại trên thị trường (nhóm bê tông nặng có ρv = 2200 - 2500 kg/m3). Kết quả nghiên cứu của mẫu bê tông tro bay hàm lượng cao cũng được so sánh với sản phẩm đối chứng theo độ tuổi bảo dưỡng 3 ngày, 7 ngày, và 28 ngày.

Nghiên cứu này thực hiện khảo sát các thông số ảnh hưởng tới quá trình trích cao ethanol từ lá trứng cá, các thông số độc lập được tối ưu bằng phương pháp bề mặt đáp ứng gồm có: nhiệt độ, tỷ lệ dung môi và nguyên liệu, thời gian chiết. Kết quả cho thấy hiệu suất chiết cao nhất là 9,77% ở điều kiện nhiệt độ 80 °C, tỷ lệ dung môi/nguyên liệu là 19 mL/g, thời gian 36 phút. Nghiên cứu cũng thực hiện định lượng tổng polyphenol, flavonoid cũng như khả năng khử gốc tự do DPPH trong cao ethanol và các cao phân đoạn. Ở phân đoạn ethyl acetate, tổng hàm lượng flavonoid, polyphenol và khả năng kháng gốc tự do cao hơn các phân đoạn khác, có giá trị lần lượt là: 93,3 (mg/g); 319,0 (mg/g) và IC50 là 6,25 µg/mL.

The simultaneous spectrophotometric determination of copper(II) and cobalt(II) is based  on the  ormation of their complexes with diethyldithiocarbamate (DDTC) in the presence of polysorbate 20 (Tween 20) as a micellar media using partial least squares modeling. The absorption spectra were  ecorded from 290 to 500 nm. The calibration graph was linear in the range of 0.5-4.0 µg.mL-1  for Cu(II) (R2 = 0.9979) and 0.5-3.0 µg.mL-1 for Co(II) (R2 = 0.9976); The root mean squared error of prediction (RMSEP) was 0.160 and correlation coefficient (R2) for copper and cobalt by PLS method were 0.988; 0.954 respectively. The results indicate the probability of the method in the simultaneous determination of copper(II) and cobalt(II).