bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly efficient transfer hydrogenation of carbonyl compounds over supported nickel and palladium nanoparticles
Authors: Thien Co Thanh , Minh Nguyen Nhut , Khang Vo Ly Dinh
Published: March 2024

In this work, metal nanoparticles were successfully synthesized through the reduction of metal salts using reducing agents such as: ethylene glycol (EG) and sodium borohydride (NaBH4). These metal nanoparticles were impregnated into the supports M‐X (M = Ni, Pd; X = Bent, C, Zeolite, and Al2O3) in high yield. The physio‐chemical properties of these catalysts were characterized by various techniques such as UV‐Vis spectroscopy, powder X‐ray diffraction (PXRD), Transmission electron microscopy (TEM) and the specific surface area of M‐X was evaluated by N2 adsorption isotherm analysis at 77 K. All results corroborated the loading process. Literally, TEM images indicated that the palladium and nickel nanoparticles size are 6 and 13 nm, respectively. The efficiency of these catalysts was performed on the transfer hydrogenation of various carbonyl substrates in the presence of potassium hydroxide at atmosphere pressure. The results showed that both nickel and palladium supported X catalysts exhibited high activities over 99 % within 60 min in the presence of potassium hydroxide.
Synthesis, characterization and anticancer properties of platinum(II) complexes bearing chiral azomethine ligands
Authors: Trung Nguyen Quang , Nam Pham Thi Phuong , Van Tuyen Nguyen
Published: March 2024

Pt(II) complexes bearing one N‐salicylidene‐(S)‐1‐phenylethylamine [HL(S)] or N‐salicylidene‐(R)‐1‐phenylethylamine [HL(R)] were synthesized and characterized by electrospray ionization mass spectroscopy (ESI‐MS), Fourier‐transform infrared (FT‐IR), nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopies. The results of the micro‐analytic and spectroscopic methods disclosed that the reaction of K2PtCl4 with the chiral azomethine ligand in DMSO produced both trans‐ and cis‐[Pt(II)L(DMSO)Cl]. Then only trans‐[Pt(II)L(DMSO)Cl] isomers in Na2CO3 solution can transform to Pt(II) complexes 3 in coordination of the ligands to platinum as tridentate C,N,O‐donors. The photophysical properties of obtained platinum(II) complexes were studied by UV‐visible and luminescent spectra. The results showed that they all exhibited emission in the visible region. Anticancer properties in vitro of obtained Pt(II) complexes were scaned for KB and HepG‐2 cancer cell lines. They had good activity for the tested cancer cells. The cis‐Pt(II) complexes possessed higher anticancer activity than trans‐Pt(II) complexes and R‐enantiomers were found to be more cytotoxic than S‐enantiomers.
Preparation and study on the properties of acrylonitrile butadiene styrene/polyphenylene oxide polymer blend
Authors: Trung Tran Huu , Huynh Mai Duc , Cong Do Van , Thai Nguyen Thi , Tham Do Quang , Nguyen  , Dat Huu , Dung Trinh Quang , Hai Luong Như , Giang Nguyen Vu
Published: March 2024

Blends of polyphenylene oxide (PPO) and acrylonitrile butadiene styrene (ABS) were prepared by melt‐mixing method. Flammability of these blends was studied by using UL‐94 (plastics flammability standard) and LOI (limited oxygen index) tests. The results showed the role of PPO as flame retardant in the blends which can inhibit the burning process. All blends of PPO and ABS were graded as V‐1 and LOI values were higher than 21. As a physical mixture, tensile strength of PPO/ABS blends maintained values between the tensile of neat ABS and PPO. Melting rheology characterization of samples showed that the fabrication of PPO/ABS blend consumed less energy than that of PPO polymer. Differential scanning calorimetry analysis investigated that PPO and ABS were partially miscible in blend with two glass transition temperatures (Tg) which ranged between Tg of ABS and PPO.
Modified bis‐tetrahydrofuran inhibitors toward improved binding to HIV‐1 proteases
Authors: Paulin John P. , Franco Francisco C.
Published: March 2024

HIV treatment includes inhibiting HIV‐1 protease which is responsible for viral maturation. However, HIV‐1 protease responds to drug treatment by mutation making the protease‐resistant to inhibitors. In this study, binding interactions between bis‐tetrahydrofuran‐derived (bis‐THF) inhibitors and HIV‐1 protease were described by molecular docking. We characterized the binding energies and all the amino acids present during the binding of the bis‐THF derivatives to the wild type HIV‐1 protease and several mutant HIV‐1 proteases. We found that the modifications to the structure of darunavir helped improve its binding to the wild‐type protease. Also, these structures were found to interact with the mutant HIV‐1 proteases better than darunavir. Results showed that compound 4 had the highest binding energy to the wild‐type HIV‐1 protease and the V654/84 mutant, while compound 5 was found to interact greatly with cyclic urea‐based inhibitor‐resistant proteases and the multi‐protease inhibitor‐resistant HIV‐1 protease. The results may help explain how structural modifications to bis‐tetrahydrofuran inhibitors affect their response to wild‐type and resistant HIV‐1 proteases. Furthermore, this study is the first demonstration of the differences in the amino acids interacting with protease inhibitors for wild‐type and mutated HIV‐1 proteases and may help in the design of bis‐THF derivatives as HIV‐1 protease inhibitors.
Electrochemical study on the structure of PbO2 in mixed gel electrolytes during cycling by cyclic voltammetry
Authors: Binh Phan Thi , Van Anh Nguyen Thi , Thuy Mai Thi Thanh , Xuan Mai Thi , Duyen Nguyen The
Published: March 2024

Pb/PbO2 electrodes are made by anodizing method from H2SO4 solution (1.26 g/cm3). The mixed gel electrolyte was prepared by mixing H2SO4 (1.37 g/cm3) with liquid glass (LG) in the presence of polyacrylamide (PAM), propylene glycol (PPG), and nano fumed silica (NFS). After finishing 150 cycles by cyclic voltammetry (CV) in different electrolytes at a scan rate of 100 mV/s, the structure of PbO2, including morphology and the content of elements, were analysed by scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS), respectively, as well as by CV diagrams. There was found a huge difference in both the grain size and surface structure of PbO2 electrodes. Among them, the morphology of PbO2 electrode after cycling in mixed gel electrolyte using PAM with NFS is similar to that obtaining from H2SO4 solution (1.26 g/cm3). The appearance of α‐ and β‐PbO2 forms depends on the combination of gelling agents. The existence of α‐PbO2 form was found only by using separate PAM or PAM with PPG leading to small discharge densities, while both α‐ and β‐PbO2 forms were clearly observed by combining PAM with NFS. The height of redox peak in this case is approximately the same as that in sulfuric acid solution.
Modeling of titania slag carbochlorination
Authors: Hai Tran Duy , Khoa Tran Anh , Vien Le Minh , Tuan Phan Dinh
Published: March 2024

Titanium tetrachloride, a product of titanium slag chlorination in the presence of carbon, is an intermediate product for high grade TiO2 pigment preparation and titanium metallurgy. The chlorination of carbon‐titanium dioxide pellets with gas mixtures of N2 and Cl2 was studied at high temperatures (750‐1050 oC) and various partial pressures of chlorine (0.1‐0.8 atm) in a fixed‐bed reactor with the inner diameter of 80 mm. Based on the comparison of experimental and computational studies, a principal mechanism of the TiO2 carbochlorination was proposed, and chlorine concentration profile at different reaction conditions was clearly understandable. Porous diffusion of chlorine inside the C‐TiO2 pellet structure played an important role in the kinetic reaction model.
N‐Formylation of amines using a domestic microwave oven and bioactivities of some N‐formamides
Authors: Mai Nguyen Thi Ngoc , Van Dat Nguyen , Huan Trinh Thi , Hoan Duong Quoc
Published: March 2024

A reasonable and chemoselective approach for N‐formylation of various amines with N,N‐dimethylformamide in presence of acetic acid has been improved under irradiation of a domestic microwave oven. The method was found to be compatible with primary, secondary, aromatic and aliphatic amines with electron withdrawing and electron donating groups as well but did not support to form N‐formate derivatives. N‐formamides 1, 2, and 3 did not exhibit antibacterial activity on Gram(+), Gram(‐) and fungi but compounds 1, 2, 18 and 19 showed weak antioxidant activity with SC: 36.8 %, 38.3 %, 45.7 %, respectively. Compound 18 exhibited antioxidant activity with SC50: 47.2 μg/mL.
Visible light photocatalytic degradation of organic dyes using W‐modified TiO2/SiO2 catalyst
Authors: Van Hung Nguyen , Nguyet Bui Thi Minh , Nghi Nguyen Huu , Nguyen Vo Thang , Binh Thai Vu , Tu Nguyen Thi Thanh , Dung Nguyen Nho , Khieu Dinh Quang
Published: March 2024

In the present study, the synthesis of W‐modified TiO2/SiO2 composite and its catalytic activity in the visible light region is demonstrated. The W‐modified TiO2/SiO2 composite was obtained from the hydrolysis of a mixture containing titanium (IV) oxysulfate, ammonium metatungstate, and SiO2 powder in an alkaline medium. The obtained materials were characterized by using X‐ray diffraction (XRD), Fourier transformation‐infrared spectroscopy (FT‐IR), high‐resolution transmission electron microscopy (HRTEM), energy dispersive X‐ray elemental mapping observation, nitrogen adsorption/desorption isotherms, photoluminescence spectra (PL), and ultraviolet visible diffusive reflectance spectroscopy (UV‐Vis DRS). In this material, W‐modified TiO2 nanoparticles of about 3‐5 nm were highly dispersed on the silica network. Both W‐modified TiO2 and W‐modified TiO2 decorated on the SiO2 substrate significantly promoted the visible light absorption of the material. The photocatalytic activity of the prepared catalyst was assessed through the photodegradation of Methylene blue, Rhodamine‐B, Methyl orange, and Congo red dyes under visible light illumination. It was found that the kinetic and equilibrium data of the photocatalytic process fitted the modified Langmuir‐Hinshelwood model well. Recyclable studies have shown that the catalyst still retained its original activity after the third cycle.
A new meroterpene lactone and a new alkyl amino alcohol from the Vietnamese marine sponge Hippospongia fistulosa Lendenfeld, 1889
Authors: Hang Dan Thi Thuy , Trang Do Thi , Yen Pham Hai , Cuc Nguyen Thi , Dung Duong Thi , Tai Bui Huu , Nhiem Nguyen Xuan , Van Kiem Phan
Published: March 2024

From the methanol extract of the marine sponge Hippospongia fistulosa Lendenfeld, 1889, a new meroterpene lactone named as hippolactone A (1), a new alkyl amino alcohol named as 2‐aminotetradec‐13‐ene‐3,4,5,6,7‐pentaol (2), and three known meroterpenes, polyfibrospongol A (3), polyfibrospongol B (4), and 19‐hydroxy‐polyfibrospongol B (5), were isolated. Their structures were elucidated by extensive spectroscopic analyses including IR, HR‐ESI‐MS, 1D and 2D NMR, and by comparison of the spectral data with those of previously reported data. Compounds 1 and 2 exhibited cytotoxic effects on Hep‐G2, MCF‐7, SK‐LU‐1, and SK‐Mel‐2 human cancer cells with percentages of dead cells in the range from 18.2±1.1 % to 43.4±1.6 %.
Cytotoxic and antimicrobial benzodiazepine and phenolic metabolites from Aspergillus ostianusIMBC‐NMTP03
Authors: Quang Tran Hong , Anh Le Ngoc , Hanh Tran Thi Hong , Cuong Nguyen Xuan , Ngan Nguyen Thi Thanh , Trung Nguyen Quang , Nam Nguyen Hoai
Published: March 2024

Six benzodiazepine alkaloids and two phenolics were isolated from an ethyl acetate extract of the fungal strain Aspergillus ostianus IMBC‐NMTP03 fermentation culture. Their chemical structures were elucidated as circumdatins D (1), E (2), J (3), and I (4), cycloanthranilylproline (5), and (11aS)‐2,3‐dihydro‐7‐methoxy‐1H‐pyrrolo[2,1‐c][1,4]benzodiazepine‐5,11(10H,11aH)‐dione (6), 4‐hydroxybenzoic acid (7), and syringaldehyde (8) by spectroscopic methods, including 1D and 2D NMR and mass spectra in comparison with the literature data. Compounds 2, 4, and 5 showed cytotoxicity toward KB, MCF‐7, and LNCaP cancer cell lines (41.14‐49.76 % cell death) while 7 was cytotoxic against HL‐60, KB and LNCaP cells (41.77‐47.06 % cell death). Compounds 1‐3 and 5‐8 displayed antimicrobial activity against Enterococcus faecalis and Candida albicans, with MIC values ranging from 18.7‐100 μM.
Rate enhancement of ‘in water’ organic transformation by anionic‐nonionic mixed micelle
Authors: Rakshit Atanu , Chowdhury Suman , Acharjee Animesh , Saha Bidyut
Published: March 2024

Micellar medium has already promising uses in organic transformations. In the present experiment, mixture of anionic and neutral surfactants (SDS and TX‐100 respectively) has been discovered as a good reaction medium for the organic transformations. The kinetics of propanal oxidation by Cr(VI) has been studied in mixed micellar medium spectrophotometrically maintaining pseudo first order reaction condition at 30 °C. The kinetics of the same reactions promoted by three hetero‐aromatic bases (Phen, PA and Bpy) have already been studied in single as well as mixed micellar medium. The valid spectroscopic evidence of formation of the product and mixed micelle formation have been provided with necessary mechanistic pathways.
Study on preparation of pregna‐4‐en‐17α,21‐diol‐3,20‐dione from androst‐4‐en‐3,17‐dione
Authors: Huy Luu Duc , Tu Duong N. , Diep Nguyen T. , Khanh Ho V. , Kazantsev A. V. , Savinova T. S.
Published: March 2024

An efficient procedure was proposed for the preparation of pregna‐4‐en‐17α,21‐diol‐3,20‐dioneby using nitrile method to result in high yield up to 56.0‐57.0 % from androst‐4‐en‐3,20‐dione, a key intermediate for producing corticoids.
A review on application of marine algae as green corrosion inhibitors in acid medium
Authors: Ismail Nabilah , Mujad Siti Mariana , Zulkifli Mohammad Fakhratul Ridwan , Izionworu Vincent Onuegbu , Ghazali Mariyam Jameelah , Nik Wan Mohd Norsani Wan
Published: March 2024

Corrosion is significant and continuous issue that causes serious problem on environment, properties, our lives and leads to economic losses. So, prevention of corrosion requires more attention. Metal corrosion inhibitors, both inorganic and synthetic, are used to prevent and slow down corrosion, although these inhibitors are hazardous. Thus, green corrosion inhibitors which both environmentally and economically are likely the solution to this problem. A lot of research has been done to discover good corrosion inhibitors from natural sources. Marine algae is one of the most valuable sources of natural marine products because of its ability to survive in the dynamic environment of the ocean and considered a natural source for corrosion inhibition. In this review, various species of marine algae are discussed as green corrosion inhibitors in terms of secondary metabolites, mechanism of inhibition, and methodologies used to evaluate the corrosion rate of different metals in acidic media.
Determination of seven parabens in surface water samples by UHPLC‐MS/MS and solid‐phase extraction
Authors: Thuy Quan Cam , Phuong Pham Thi , Thien Tran Lam Thanh , Minh Bui Quang
Published: March 2024

Parabens are considered one of the ideal preservatives in numerous consumer products due to their high antimicrobial properties. Nevertheless, parabens have the following potentially detrimental effects on human health such as adverse effects on male reproductive system, or accelerated skin aging process and breast cancer. Here, ultra‐high performance liquid chromatography (UHPLC) coupled with a triple quadrupole mass spectrometry (MS/MS) combined with a solid‐phase extraction procedure was optimized for measuring seven parabens in surface water and proposed as a modified analytical method. The optimized protocol was validated according to the requirements of European standard SANTE/12682/2019. The limits of detection and quantification of the method obtained were 0.04 and 0.82 ng L‐1, respectively. The validated method was applied to analyzing surface water samples collected in Hanoi, Vietnam, indicating not only the presence of seven targeted parabens but also the prevalence of methylparaben in all water samples.
Electronic and optical properties of facial tris(8‐hydroxyquinoline) aluminum derivatives
Authors: Abdelfettah Bakadi , Abderrachid Helmaoui
Published: March 2024

In this study, we substitute facial Alq3 with (‐Mg) in positions 7 and 5 as electron donating group (EDG) and (‐Cl), (‐P) and (‐S) in position 7 as electron withdrawing groups (EWD). The ground and the first excited states geometries of facial Alq3 and their derivatives are optimized using B3lyp/6‐31G (d) methods. To analyse the electric transitions in these materials, the frontier molecular orbitals (FMOs) are calculated. It was found that the highest occupied molecular orbital (HOMO) is mainly situated on the phenoxide ring, while the lowest unoccupied molecular orbital (LUMO) is situated on the pyridyl ring, the atom C9 of phenoxide or in EWD atom. The dipole moment is calculated and analysed. The absorption and emission spectra are calculated with the TD‐DFT/6‐31G (d) method. It is seen that the electron donating or electron withdrawing groups in 7 positions caused a red‐shift in the absorption and emission spectra; what means that these substitutes have a significant effect on fac‐Alq3.
Chemical constituents of Clathria reinwardti
Authors: Trang Do Thi , Hang Dan Thi Thuy , Dung Duong Thi , Bang Ngo Anh , Huong Phan Thi Thanh , Yen Pham Hai , Tai Bui Huu , Cuc Nguyen Thi , An Do Hoai , Nhiem Nguyen Xuan , Thung Do Cong , Van Kiem Phan
Published: March 2024

Seven compounds, dihydrosinularin (1), 11‐epi‐sinulariolide acetate (2), 10,18‐diacetoxydilabella‐2,7‐dien‐6‐one (3), 4‐(2′,3′,4′‐trimethylphenyl)‐but‐(3E)‐en‐2‐one (4), 4‐hydroxybenzaldehyde (5), indole‐3‐aldehyde (6), and methyl indole‐3‐carboxylate (7) were isolated from Clathria reinwardti. The isolates were identified by ESIMS, 1D and 2D NMR spectra. Compounds 1‐4 significantly exhibited the cytotoxic activity against SK‐LU‐1, MCF‐7, HepG2, and SK‐Mel‐2 cell lines with the IC50 values ranging from 3.8 ± 0.1 to 23.0 ± 0.2 μM, compared to the positive control compound (ellipticine, IC50, ranging from 1.4 ± 0.2 to 1.7 ± 0.1 μM). This is the first report of these compounds from C. reinwardti.
Controllable synthesis of uniform MgAl‐hydrotalcite nanoplates and their size‐dependent on anti‐corrosion properties of carbon steel
Authors: Vuong Phan Minh , Thoa Tran Thi Kim , Nhu Pham Quynh , No Nguyen Thi Hong , Ty Nguyen Minh , Huy Do Manh , Thao Phan Thanh , Hang To Thi Xuan
Published: March 2024

Hydrotalcite, a three dimensional anionic clay with a high anion exchange capacity, is a potential candidate for application in various fields, especially in anti‐corrosion. This study reports a facile synthesis to control the uniform particle size and well‐defined MgAl‐hydrotalcite hexagonal nanoplates in stable homogeneous suspension. The synthesized crystals were characterized by XRD, FTIR, TG‐DSC, ICP‐MS, and FE‐SEM. The results show that the crystals are well‐controlled particle size and morphology of individual sheets. The stability of products was confirmed using zeta potential measurement for three months at room temperature, and the lateral dimension was controlled between 50 and 300 nm. The influence of particle size on the corrosion inhibition effect of carbon steel was investigated by electrochemical measurement. The polarization curves and impedance diagrams indicated that the corrosion resistance effect of MgAl‐HT depends on both sides of the surface electric and the level deposition of crystallite on the electrode surface. The highest effective inhibition is 80.18 %, archiving on the diameter across 152.1 nm of hexagonal nanoplates.
A one‐stage sono‐coprecipitation synthesis of porous Fe3O4/bentonite nanocomposite as an adsorbent for methylene blue removal in water
Authors: Linh Ha Xuan , Trung Nguyen Thanh , Van Thanh Dang , Huy Nguyen Nhat , Dung Nguyen Quoc , Toan Tran Quoc , Mai Nguyen Thi , Thuy Nguyen Thi , Khai Nguyen Manh
Published: March 2024

A porous Fe3O4/bentonite nanocomposite (FBC) was successfully synthesized via an efficient and green co‐precipitation reaction under ultrasonic assistance. The FBC material was characterized by XRD, BET, FTIR and SEM and employed for removing methylene blue from the aqueous solution. The results showed that this nanocomposite owned a reasonably high BET surface area of 98.36 m2/g and pore size of 9.32 nm. Adsorption isotherms were also studied for FBC material and methylene blue adsorption isotherm fitted well to Langmuir model with maximum adsorption capacity of 181.82 mg/g. The n value of Freundlich isotherm was 14.45 which indicated physical nature of the adsorption process. It demonstrated the great potential of the material in pollutants adsorption in water and wastewater treatment.
Hydrazineylidene‐3‐oxopropanal derivatives as antiviral agents for treatment of HBV and HCV: Experimental, DFT, and molecular docking studies
Authors: Benjamin Innocent , Louis Hitler , Udoikono Akaninyene D. , Agwamba Ernest C. , Unimuke Tomsmith O. , Ahuekwe Eze F.
Published: March 2024

In this study, two derivatives of hydrazineylidene‐3‐oxopropanal: chlorophenyl (CPHO) and Nitrophenyl (NPHO) substituted hydrazineylidene compounds were synthesized, spectroscopically characterized using (FT‐IR, UV, and NMR), and theoretically modelled as a potential drug for the treatment of antiviral hepatitis (HBV and HCV) using in‐sillico molecular docking approach. Electronic structure investigation based on density functional theory (DFT) at the B3LYP/6‐311++G(d,p) level of theory was conducted for the investigation of the structural, reactivities, and electronic properties of the studied compounds. The FT‐IR analysis in gas, water, ethanol and DMSO indicates a maximum stretching vibrations frequencies of C‐H in NPHO between 3249.38 to 3254.77 cm‐1 and 3236.04 to 3240.66 cm‐1 for CPHO, N‐H for NPHO is 3309.81 to 3336.37 cm‐1, and CPHO is 3330.11 to 3331.18 cm‐1, C=O in NPHO to be 1685.55 to 1705.60 cm‐1, and 1700.31 to 1679.15 cm‐1 for CPHO. The C‐N stretching vibrations in NPHO were 1519.98 to 1562.06 cm‐1 and 1430.05 to 1460.33 cm‐1 for CPHO. The UV‐Vis analysis indicates that NPHO wavelength absorption spectrum showed high excitation energy bands between 369.74 to 440.60 nm and CPHO at 178.95 to 434.08 nm. The highest stabilization energy of NPHO is LP (1) N12 donor and LP*(1) H10 acceptor with a value of 417.54 kcal/mol compared to πC17 ‐ O18 donor and π*C19 ‐ C28 acceptor with a value of 108.33 kcal/mol for CPHO. The molecular binding affinity of CPHO and NPHO had a high mean binding affinity of ‐5.83 and ‐6.05 kcal/mol, compared to the standard antiviral drugs with ‐5.00 kcal/mol. Therefore, the compounds show excellent reactivity based on the electronic structure, spectroscopic characterization and represent a potential antiviral agent treatment for HBV and HCV.
Plant extract mediated approach towards the synthesis of NiO nanoparticles: Evaluation of its antibacterial, antioxidant and photocatalytic activity
Authors: Ahmad Waseem , Bhatt Sumit Chandra , Kaur Nikky
Published: March 2024

Bio‐extract based nanoparticles have now become a global phenomenon. Their superior properties to the bulk material, and low cytotoxicity has made them essential component of nanotechnology. The current research was based on the phyto‐synthesised NiO nanoparticles by using Catharanthus roseus plant leaf extract. Sol gel method was used for this synthesis. The plant extract plays a significant role in the fabrication of nanoparticles. For characterization UV‐Vis spectroscopy, X‐ray diffraction analysis, FT IR analysis and scanning electron microscopy (SEM) were used. They were also examined for their antibacterial properties by using agar diffusion method (ADM) against different bacteria (gram negative strain of E. coli, Pseudomonas spp. and gram positive strain of Bacillus spp.). Photocatalytic degradation proficiency was studied for bromothymol blue dye. Phytochemicals‐coated Nickel Oxide nanoparticles demonstrated antibacterial properties against bacteria (gram negative strain of E. coli, Pseudomonas spp. and gram positive strain of Bacillus spp.) by showing highest zone of inhibition (19 mm, 22 mm, 15 mm).the antioxidant activity of the synthesized nanoparticles were also examined and the result show that the fabricated nanoparticles exhibited significant radical scavenging activity. Degradation proficiency of nanoparticles for bromothymol blue dye was found to be 2.76% in sunlight (for 90 min), and 1.76% in UV light (for 90 min).
Fabrication and characterization of PMMA/ZrO2 nanocomposite 3D printing filaments
Authors: Linh Nguyen Thi Dieu , Huy Khuc Duong , Dung Nguyen Thi Kim , Luong Ngo Xuan , Hoang Thai , Tham Do Quang
Published: March 2024

The 3D printing PMMA/ZrO2 filaments with a diameter of 1.75 ± 0.05 mm were fabricated by using a single‐screw extruder at temperatures of four heating zones of 190, 200, 210, and 210°C. Testing samples were prepared from the extruded filaments by using a fusion deposition modeling 3D printer and a Haake MiniJet piston injection molding machine. Fourier transform infrared spectroscopy, mechanical properties, field emission scanning electron microscopy (FESEM), differential scanning calorimetry, and thermogravimetric analysis of the filaments were investigated. It was suggested the formation of physical and molecular interactions between surface hydroxyl groups of ZrO2 nanoparticles and C‐O‐C groups of PMMA in the PMMA/ZrO2 filaments. FESEM images of the filaments indicated the good dispersion of ZrO2 nanoparticles in the PMMA matrix, nevertheless, there was still the formation of clusters of ZrO2 nanoparticles in the nanocomposite filaments. The incorporation of nano ZrO2 increased the thermal properties, bending, and tensile moduli of PMMA. The mechanical properties of the 3D‐printed samples were lower than those of the molded samples. However, the bending strength of the 3D‐printed samples was much higher than 50 MPa, bending modulus was much higher than 1800 MPa, as required for acrylic bone cement (in ISO 5833:2002).
In situ synthesis and characterization of nano‐hydroxyapatite/starch composites
Authors: Huong Nguyen Thi Lan , Tuan Phan Dinh , Bich Phan Thi Ngoc , Thao Nguyen Minh , Tung Mai Thanh
Published: March 2024

Nano‐hydroxyapatite/starch composite was synthesized using in situ precipitation. Starch concentration effect on the structure of composite was examined. Characterization of the obtained samples, The X‐ray diffraction and Fourier transform infrared spectroscopy demonstrated the purity of the formed nano‐HA in the starch matrix. Morphology studies of the samples, checked by field emission scanning electron microscope and transmission electron microscope, show the effects of starch on the size, shape, and morphology of hydroxyapatite nanoparticles.
Coatings made from chemicals: A review
Authors: Chowdhury Suman , Nepal Sadiksha , Bhattarai Ajaya , Saha Bidyut
Published: March 2024

In the ongoing process of civilization, surface modification has become almost an indispensable route to enjoy the optimum benefit from any material in the materialistic world. Especially, active metals require the modification maximum to escape the natural corrosion or passivation. The retention of sound performance of the metals as well as extension of their lifetime can be achieved by surface modification of coating formation. Chemical coating is one of the simple and low‐cost methods of coating with great versatility including pre‐treatment and post‐treatment. This paper includes the most widely used inorganic and organic chemical coating methods and their fewer details and their future outlooks.
Preparation and characterization of achira starch oxidized by different concentration of sodium hypochlorite
Authors: Van Khoi Nguyen , Tung Nguyen Thanh , Ha Pham Thi Thu , Trang Pham Thu , Duc Nguyen Trung , Huong Nguyen Thu , Phuong Nguyen Thi Lien
Published: March 2024

In this study, achira (Canna edulis) starch was oxidized by sodium hypochlorite and the effects of different concentration of oxidation agent (1, 2, 3 and 5%) on the physicochemical properties, morphological properties and crystallinity of achira starch (AS) was investigated. The carbonyl and carboxyl content, starch colour parameters, swelling capacity, solubility, IR spectra, SEM and XRD of native and oxidized achira starch (OAS) were evaluated. IR spectra of oxidized starch samples showed a new absorption peak which was assigned to the characteristic peak of carbonyl C=O, proved that starch had been oxidized. At lower concentration of sodium hypochlorite, there was no clearly change on the morphology of OAS granules, however, at higher concentration of oxidant (5%), there were some indentations and cracks on the surface of OAS‐5 starch granules. Oxidation with sodium hypochlorite has no significant effect on the crystallinity of the starch. Both AS and OAS granules showed the typical B‐type X‐ray diffractogram, indicating that the oxidation occurred in the amorphous region. After treating with oxidized agent, content of carboxyl groups increased significantly, whereas content of carbonyl groups slightly increased. The total oxidation degree of OAS samples increased with the increase of the concentration of hypochlorite treatment. Oxidation with sodium hypochlorite clearly increased both the swelling capacity and solubility of achira starch. Whiteness of starch was also improved.
Simple synthesis of mesoporous ferrite materials as magnetic adsorbents for phosphate removal
Authors: Ngo Duc Toan , Hoang Thanh Danh Nguyen , Pham Nguyen Anh Thu , Dang Tien Thi Thuy , Nguyen Quoc Thiet , Le Tien Khoa
Published: March 2024

Mesoporous MFe2O4 materials (M = Mn, Cu, and Co) as magnetic adsorbents for phosphate removal were synthesized by a simple coprecipitation method without annealing at high temperatures. Several techniques, including powder X‐ray diffraction, field emission electron scanning microscopy, nitrogen adsorption‐desorption and vibrating sample magnetometry were used to characterize the samples. The effects of M2+ ions on their point of zero charge and their phosphate adsorption capacity were investigated. All three samples consist of nanosized particles with cubic spinel structure and ferromagnetic properties, which allows them to be easily separated from aqueous effluents using a magnet. According to the batch experiments, the adsorption isotherms and the adsorption kinetics for these mesoporous materials are well fitted with the nonlinear Langmuir model and the nonlinear pseudo‐second‐order model, respectively. Among them, CuFe2O4 powder showed the best phosphate adsorption performance with the maximum P adsorption capacity of 27.49 mgP g‐1, which can be assigned to the highest surface area and the high pH value at its point of zero charge.
Recovery of Chlorella biomass using Fe3O4 and Fe3O4@SiO2 magnetic nanoparticles: isotherm and thermodynamic characteristics of adsorption
Authors: Van Do Thi Cam , Van Toan Lam , Dung Nguyen Thi Phuong , Thuan Tran Dang , Cuc Dinh Thi , Mai Dang Thi , Huong Pham Thi Mai , Yen Pham Thi Thanh
Published: March 2024

Harvesting microalgae by centrifugation and filtration is very costly, affecting technical and economical feasibility of downstream processing of algal biomas to bioproducts. Flocculation is a potential technique for recovery of algae biomass. Particularly, flocculation using magnetic nanoparticles offers high separation efficiency due to their high surface area and magnetic properties. In this work, the synthesized magnetic nanoparticles including Fe3O4 and Fe3O4@SiO2 were used to harvest C. sorokiniana TH01 from aqueous suspension. The effects of pH, adsorbent dosage, algal biomass concentration, temperature and reaction time on harvesting performance were investigated. It was revealed that the optimal C. sorokiniana TH01 harvesting conditions for Fe3O4 were pH of 5, adsorbent dosage of 0.5 g/L, biomass concentration of 2‐2.5 g/L, temperature 25oC and reaction time 20‐30 min. For Fe3O4@SiO2, the optimal conditions were pH of 7, adsorbent dosage of 0.6 g/L, with the same biomass concentration, temperature and reaction time as Fe3O4. Under the optimal conditions, Fe3O4 and Fe3O4@SiO2 can be regenerated up to three cycles with harvesting efficiency till remained over 55%. Adsorption of C. sorokiniana TH01 on Fe3O4 and Fe3O4@SiO2 exhibited the best fitness with Langmuir isortherm with R2 and maximal adsorption capacity estimated of 0.995 and 6.55 g/g and 0.9971 and 9.53 g/g, respectively. Thermodynamics study revealed that an adsorption of C. sorokiniana TH01 on Fe3O4 and Fe3O4@SiO2 was exothermic process. Furthermore, XRD, EDS, SEM, TGA and FT‐IR data confirmed the successful binding of microalgae cells on surfaces of Fe3O4 and Fe3O4@SiO2. The super‐magnetization intensities (> 22 emu/g) of the synthesized materials demonstrated an excellent separation capability with external magnetic devices.
A previously undescribed phenolic compound from Acanthus ilicifolius L.
Authors: Mai Nguyen Thi , Huyen Le Thi , Hanh Le Thi My , Huong Phan Thi Thanh , Nhiem Nguyen Xuan , Tai Bui Huu , Van Kiem Phan
Published: March 2024

The plants Acanthus ilicifolius L. (Acanthaceae) are used in Vietnamese folk medicine for the treatment of stomach pain, hepatitis, asthama, and rheumatism. Phytochemical study on the methanol extract of the aerial parts of this plant led to the isolation of seven phenolic compounds, (2R,3R,4R)‐3,4‐dihydroxy‐7‐methoxyflavan 5‐O‐[β‐D‐apiofuranosyl‐(1→6)]‐β‐D‐glucopyranoside (1), quercitrin (2), isoquercitrin (3), kaempferol 3‐O‐α‐L‐arabinopyranoside (4), kaempferol 3‐O‐α‐L‐rhamnopyranoside (5), kaempferol 3‐O‐β‐D‐glucopyranoside (6), and 6‐O‐vanilloylarbutin (7). Among these isolates, compound 1 was previously undescribed compounds. Their chemical structures and the absolute configurations of the new compound were elucidated by 1D‐, 2D NMR, HR‐ESI‐MS and ECD spectroscopic techniques. The known compounds were identified by comparison their NMR spectral data with those reported in the literature.
Equilibrium, kinetic and thermodynamic studies for the purification of wastewater from Congo red using simple and low cost adsorbents
Authors: Shakeel Muhammad , Khizar Sania , Atiq Adeel , Ali Shahid
Published: March 2024

This manuscript reports the purification of wastewater from Congo red (CR) by adsorbing it on sawdust of Pinus walichiana (PW) and Populus ciliata (PC) used as adsorbents. The adsorbents were characterized by Field emission scanning electron microscopy (FESEM), Energy dispersive X‐rays (EDX) spectroscopy, X‐rays diffraction (XRD) and BET surface area and pore size analysis. Different adsorption models like Langmuir, Temkin, Freundlich and Dubinin‐Radushkevich (R‐D) were applied to the system. The adsorption of CR on sawdust of both plants followed Freundlich adsorption isotherm to greater extent than Langmuir and Temkin isotherms which means that the surface of adsorbents was mostly heterogeneous and there occurred adsorbate‐adsorbate interaction which influenced the adsorption process. The process also obeyed D‐R model and mean free energy of adsorption was calculated to be 7.11 kJ.mol‐1 showing that the process of adsorption was physical. Adsorption of CR on both adsorbents followed film diffusion, particle diffusion, pseudo first order and Elovich models. It means that the process of adsorption was mixed diffusional in nature, occurred through physical process, the sites for adsorption increased exponentially with adsorption and multimolecular layer was formed on the surface of adsorbents. ∆H was 3.77 kJ.mol‐1 and 15.92 kJ.mol‐1, ∆S was 19.49 kJ.mol‐1 and 85.91 kJ.mol‐1 while ∆G was (‐1.75 to ‐2.33) kJ.mol‐1 and (‐8.39 to 10.97) kJ.mol‐1 for PW and PC, respectively. It means that the adsorption process was endodermic, resulted in increase in entropy and spontaneous for both the adsorbents. Isoelectric point (IEP) was determined by salt addition method, and it was found to be 6.9 for sawdust of PW and 5.1 for PC. The process of adsorption was found to be higher in the low pH range for both the adsorbents.
Structural, electrical and optical studies on organic NLO single crystal of N‐benzyl‐2‐methyl‐4‐nitroaniline (BNA)
Authors: Sathishkumar G. , Lenin M. , Gubendiran T. , Sathiyamoorthy B. , Nithiyanantham S. , Ramasamy P.
Published: March 2024

The 2‐methyl‐4‐nitroaniline (NA) was converted into the raw material N‐benzyl‐2‐methyl‐4‐nitroaniline (BNA), and the solubility of BNA in various organic solvents was calculated gravimetrically. BNA's solubility and crystal structure make it an excellent solvent for the low‐temperature solution growth method used to create single crystals of BNA with orthorhombic structure studied through single crystal analysis. Methanol was used to harvest the 3×10 mm3 BNA single crystals, which are big, translucent yellow crystals. BNA, the subject compound, the exothermic and endothermic nature was characterised by TG analyses, differential scanning calorimeter (DSC), functional studies by infrared (IR) spectra, NMR spectral and optical transmission studies. An Nd:YAG laser (1064 nm) was used to observe the second harmonic generation (SHG) of grown crystal leads about 3 times more than KDP crystal. Possible polarization for various temperatures, the crystal's dielectric properties was measured as a function of frequency. Larger surface morphology with high optical to wave conversion efficiency and the results were reviewed. Responding to electric field to leads to liquid crystal display and THz purposes.
Effect of micro‐sized luffa cylindrica fibers on the mechanical properties of epoxy epikote 828
Authors: Trung Dang Huu , Huu Nguyen The , Anh Nguyen Tuan , Oanh Doan Thi Yen , Viet Nguyen Minh , Hai Trinh Thi , Van Bach Tran , Van Bang Nguyen
Published: March 2024

Micro‐sized luffa cylindrica fibers (MLCFs) are made from raw luffa natural fibers from Vietnam and are environmentally friendly while possessing good mechanical strength. This work focuses on the mechanical properties of composite based on epoxy epikote 828 reinforced with MLCFs, particularly the fracture toughness. The results show that the MLCFs content has a great influence on the fracture toughness, especially the critical‐stress intensity factor (KIC) and izod impact strength of composite. Specifically, when using MLCFs reinforced from 0 to 2.0 wt.%, the critical‐stress intensity (KIC) increased from 1.89 to 4.60 MPa.m1/2, while the izod impact strength increased from 3.6 to 7 KJ/m2, respectively. The thermal behavior of the composite reinforced with MLCFs at different contents was determined using thermogravimetric analysis (TGA). The surface fracture structure of the composite samples was determined using scanning electron microscopy (SEM) method.
Extrarenal nephroblastomas in the inguinal region and paraspinal musculature with vertebral involvement and spinal cord compression in a 12‐year‐old dog
Authors: Soler Marta , Pérez‐Hernández María , Buendía Antonio J. , Agut Amalia
Published: March 2024

A 12‐year‐old, entire, male shar‐pei was presented with a 1‐month history of depression, lumbar pain and progressive hindlimb weakness. In addition, the owners had noticed a mass in the right inguinal region. Computed tomography showed a contrast‐enhanced soft tissue mass located at the right paraspinal musculature, affecting the vertebral body of T13, invading the vertebral canal and compressing the spinal cord. The inguinal mass showed similar imaging characteristics. Due to the uncertain prognosis, euthanasia was recommended, and postmortem examination was requested. Microscopic and immunohistochemical findings were consistent with ectopic nephroblastomas. According to this case report, ectopic nephroblastomas should be considered within the differential diagnosis of masses affecting the paraspinal musculature, as well as the inguinal region, even in senior dogs. To the authors’ knowledge, this is the first report of two ectopic nephroblastomas presented in different locations in a dog.
Sustainable electrode material from waste plastic for modern energy storage devices
Authors: Shrivastava Kriti , Jain Ankur
Published: March 2024

Among the total 17 UN‐SDGs (sustainable development goals) proposed by the United Nations, the goal 7 basically ensures easy global availability of sustainable, clean, cost effective, reliable, and modern energy. Researchers are primarily concentrating on renewable energy sources in this direction since they are sustainable, clean, and environmentally friendly. But there are numerous obstacles, such as their low reliability, irregular nature, remote availability, and so forth, that prevent them from being widely used in commercial applications. Combining these renewable energy sources with effective and affordable energy storage technologies can be a promising solution to approach concerns including rising energy consumption, reliable and consistent electric power, and better grid stability. Modern energy storage systems such as electric double layer capacitor (EDLC) and lithium‐ion batteries have a great deal of potential for a wide range of applications. Carbon‐derived materials are the most flexible and fundamental materials for the storage and conversion of modern energy. Since it requires the pyrolysis and activation of expensive starting materials like wood, petroleum, and coal, the commercially produced activated carbon is costly and unsustainable. Due to rapidly increasing amount of plastic waste and the requirement for sustainable development, the conversion of waste plastics into valuable yet inexpensive carbon nanomaterials have attracted significant research interest. Their outstanding capability for charge accumulation and transportation is due to their enormous surface area, high chemical stability, and electrical conductivity in combination with low density. The present article examines the necessity and the efforts undertaken to develop supercapacitors and Li‐ion batteries as sustainable modern energy storage devices using recycled waste plastic.

This article is categorized under:

Sustainable Development > Goals

Emerging Technologies > Energy Storage
Hate speech detection in social media: Techniques, recent trends, and future challenges
Authors: Rawat Anchal , Kumar Santosh , Samant Surender Singh
Published: March 2024

The realm of Natural Language Processing and Text Mining has seen a surge in interest from researchers in hate speech detection, leading to an increase in related studies. This analysis aims to create a valuable resource by summarizing the methods and strategies used to combat hate speech in social media. We perform a detailed review to achieve a deep knowledge of the hate speech detection landscape from 2018 to 2023, revealing global incidents of hate speech in 2022–2023. Sixty‐six relevant articles were selected for this review. Existing studies were analyzed and categorized into five method categories: Machine Learning, Deep Learning, Ensemble models, Graph Neural Networks, and Graph Convolutional Networks. These advancements can aid social networking services in identifying hate messages before being posted, reducing the risk of harassment. The review also covers available hate speech datasets and highlights research challenges, but it is clear that a definitive solution to this problem is yet to be found. Future research directions are recommended to address the ongoing challenges in Hate Speech Detection.

This article is categorized under:

Applications of Computational Statistics > Computational Linguistics

Statistical Learning and Exploratory Methods of the Data Sciences > Knowledge Discovery

Statistical Learning and Exploratory Methods of the Data Sciences > Classification and Regression Trees (CART)

Statistical Learning and Exploratory Methods of the Data Sciences > Text Mining
Setting the Film Studio Stage
Authors: Street Sarah
Published: March 2024

This chapter introduces the book’s main themes and approaches, setting out the key questions it engages with regarding Pinewood’s history and reputation. Relevant literature on Pinewood and film studios is surveyed as context for the book’s film-historical-materialist methodology combined with a ‘tectonic’ approach applied in the context of film studio analysis. The chapter presents a brief early history and information about Pinewood’s foundation in 1936, its development as a studio facility, and its experience of being requisitioned during the Second World War. The chapter sets out how the book’s particular structure and ‘pivot’ focus produces a micro history which offers new insights into the material, cultural, and social role of film studios during a key period of British film history.
In the Studio and on Location: Mapping Pinewood’s Culture in 1947–1950
Authors: Street Sarah
Published: March 2024

This chapter focuses on films produced by the Independent Producers at Pinewood during 1947, a key year in which the film industry was under great pressure to produce more films. It examines in detail the new techniques and approaches to set design in the films Blanche Fury (1948), The End of the River (1947), The Woman in the Hall (1947), Oliver Twist (1948), The Red Shoes (1948), Esther Waters (1948) and London Belongs to Me (1948). Experiments in Technicolor design in particular emerge as an important theme, and also techniques used for films shot primarily on location. The chapter concludes with an overview and assessment of the immediate post-war years when Pinewood supported many productions whose art direction practices and working methods were very much situated in the exigencies of post-war shortages and studio rehabilitation.
From classrooms to controllers: how school closures shaped children's video gaming habits
Authors: Abed Alah Muna , Abdeen Sami , Bougmiza Iheb , Selim Nagah
Published: March 2024

Objectives

This study aimed to assess the impact of COVID-19-related school closures on screen time and video gaming habits among governmental school students in Qatar and explore the prevalence of Internet Gaming Disorder (IGD) within this context.

Methods

A cross-sectional approach was employed, spanning two months from June to August 2022. A random sample of students aged 8–15 years was drawn from the national electronic health record system of Qatar. Telephone interviews with parents were conducted to collect data. The Parental Internet Gaming Disorder Scale (PIGDS) was used for IGD assessment.

Results

Of 428 parents, 257 (60%) confirmed their child's engagement in video gaming during school closures. Participants averaged 11 years in age with 92 (35.8%) females and 165 (64.2%) males. Nationality included 62.6% expatriates and 37.4% Qatari locals. Average weekly screen time increased significantly from 19.7 ± 10.1 h to 31.9 ± 12.6 h during closure (p < 0.001). Video gaming time rose from 8.6 ± 8.6 h to 13.0 ± 12.4 h per week (p < 0.001). The prevalence of IGD was 8.6% (95% CI 5.4–12.7). Male students, expatriates, and those reporting increased video gaming time were more likely to develop IGD than their female and local counterparts.

Conclusion

The observed associations between video gaming increase and IGD highlight the need for focused interventions to address potential risks and promote healthier digital habits among this population.
Regional trends in the number of COVID-19 cases
Authors: Chujo Keisuke , Seki Tatsunori , Murata Toshiki , Kimura Yu , Sakurai Tomoaki , Miyata Satoshi , Inoue Hiroyasu , Ito Nobuyasu
Published: March 2024

In this study, we analysed the novel coronavirus disease (COVID-19) cases data to investigate the regional infection trends in Japan. There had been seven outbreaks by October 2022 in Japan. In each outbreak, the number of COVID-19 cases has increased at different rates in different regions. The prefectural infection ratio is defined using COVID-19 cases data. We calculate the prefectural infection ratio and study the characteristic of each pandemic wave. The prefectural order of infection progression is estimated in each past wave of the COVID-19 pandemic. This study shows that the infection spread from the Kanto region in the fourth pandemic wave and the infection spread simultaneously from four regions in the sixth wave. It is also found that the infection situation trend in Okinawa differs from that in the other regions.