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  • 1
    Online Resource
    Online Resource
    Phenol Red Adsorption from Aqueous Solution on the Modified Bentonite
    Hindawi Limited ; 2020
    In:  Journal of Chemistry Vol. 2020 ( 2020-07-28), p. 1-14
    Details
    In: Journal of Chemistry, Hindawi Limited, Vol. 2020 ( 2020-07-28), p. 1-14
    Abstract: In the present work, the modified bentonites were prepared by the modification of bentonite with cetyltrimethylammonium bromide (CTAB), both cetyltrimethylammonium bromide and hydroxy-Fe cations and both cetyltrimethylammonium bromide and hydroxy-Al cations. X-ray diffraction (XRD), thermal analysis (TG-DTA), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and nitrogen adsorption/desorption isotherms were utilized to characterize the resultant modified bentonites. The modified bentonites were employed for the removal of phenol red dye from aqueous solution. Phenol red adsorption agreed well with the pseudo-second-order kinetic model. The equilibrium data were analyzed on the basis of various adsorption isotherm models, namely, Langmuir, Freundlich, and Dubinin‒Radushkevich models. The highest monolayer adsorption capacity of phenol red at 30°C derived from the Langmuir equation was 166.7 mg·g −1 , 125.0 mg·g −1 , and 100.0 mg·g −1 for CTAB‒bentonite, Al‒CTAB‒bentonite, and Fe‒CTAB‒bentonite, respectively. Different thermodynamic parameters were calculated, and it was concluded that the adsorption was spontaneous (∆ G °  〈  0) and endothermic (∆ H °  〉  0), with increased entropy (∆ S °  〉  0) in all the investigated temperature ranges .
    Type of Medium: Online Resource
    ISSN: 2090-9063 , 2090-9071
    URL: Article
    DOI: 10.1155/2020/1504805
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2020
    detail.hit.zdb_id: 2393625-3
    detail.hit.zdb_id: 2703077-5
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  • 2
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    Biological Characteristics and Antimicrobial Activity of Endophytic Streptomyces sp. TQR12-4 Isolated from Elite Citrus nobilis Cultivar Ham Yen of Vietnam
    Hindawi Limited ; 2016
    In:  International Journal of Microbiology Vol. 2016 ( 2016), p. 1-7
    Details
    In: International Journal of Microbiology, Hindawi Limited, Vol. 2016 ( 2016), p. 1-7
    Abstract: Ham Yen orange ( Citrus nobilis Lour) is the highly valuable commercial fruit of Vietnam. With the blooming of fruit production and farming area, this specialty crop is facing threats from several serious diseases; therefore the search for new effective biocontrollers is required to prevent the existing excessive use of fertilizers and plant protection chemicals. Endophytic actinomycetes are of great scientific interest due to their high potential of application in agriculture and pharmaceutical research. In this work, endophytic actinomycetes were isolated from a native orange species of Northeast mountainous province Tuyen Quang. Among 49 isolates obtained, the isolate TQR12-4 strongly inhibited test pathogens Colletotrichum truncatum , Geotrichum candidum , Fusarium oxysporum , and F. udum . This isolate gave comparatively high biomass yields on different substrates, for example, carboxy methyl cellulose, starch, protein, and chitin, within a wide range of temperature from 15 to 45°C and pH from 4 to 10. Sequence analysis of 16S rDNA gene showed that TQR12-4 shared 99% similarity to Streptomyces prasinopilosus ; however, it slightly differed from the latter in spore morphology and hence was named as Streptomyces sp. TQR12-4. A thermostable antifungal substance of nonpeptide nature produced by Streptomyces sp. TQR12-4 had MIC against Fusarium udum of 100  μ g/mL and 400  μ g/mL respective to extract fractions X 4 and X 5 .
    Type of Medium: Online Resource
    ISSN: 1687-918X , 1687-9198
    URL: Article
    DOI: 10.1155/2016/7207818
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2016
    detail.hit.zdb_id: 2467270-1
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  • 3
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    The Benzylation of p-Xylene Using ZnFe2O4 Nanoparticles as Heterogeneous Catalyst
    Hindawi Limited ; 2022
    In:  Journal of Nanomaterials Vol. 2022 ( 2022-4-4), p. 1-12
    Details
    In: Journal of Nanomaterials, Hindawi Limited, Vol. 2022 ( 2022-4-4), p. 1-12
    Abstract: In this paper, ZnFe2O4 nanomaterial synthesized in different solvents by hydrothermal method was used as catalyst for the benzylation of p-xylene. ZnFe2O4 catalyst was characterized by XRD, EDX, SEM and nitrogen adsorption/desorption isotherms. The influence of various parameters in the benzylation of p-xylene such as the Fe content of the prepared materials, the ratio molar of p-xylene/benzyl chloride, the catalyst dosage, and the temperature was investigated. The relationship between adsorption kinetics and reaction kinetics of p-xylene benzylation over ZnFe2O4 nanoparticles was discussed. The results indicated that ZnFe2O4 catalyst synthesized in ethylene glycol (ZFO-EG) showed high conversation for the benzylation of p-xylene. The reusability of the ZFO-EG catalyst was also investigated.
    Type of Medium: Online Resource
    ISSN: 1687-4129 , 1687-4110
    URL: Article
    DOI: 10.1155/2022/6490334
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2022
    detail.hit.zdb_id: 2229480-6
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  • 4
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    The Shifts of Band Gap and Binding Energies of Titania/Hydroxyapatite Material
    Hindawi Limited ; 2014
    In:  Journal of Composites Vol. 2014 ( 2014-07-10), p. 1-5
    Details
    In: Journal of Composites, Hindawi Limited, Vol. 2014 ( 2014-07-10), p. 1-5
    Abstract: The titania/hydroxyapatite (TiO 2 /HAp) product was prepared by precipitating hydroxyapatite in the presence of TiO(OH) 2 gel in the hydrothermal system. The characteristics of the material were determined by using the measurements such as X-ray photoemission spectroscopy (XPS), X-ray diffraction (XRD), diffuse reflectance spectra (DRS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX). The XPS analysis showed that the binding energy values of Ca (2p1/2, 2p3/2), P (2p1/2, 2p3/2), and O 1s levels related to hydroxyapatite phase whereas those of Ti (2p3/2, 2p1/2) levels corresponded with the characterization of titanium (IV) in TiO 2 . The XRD result revealed that TiO 2 /HAp sample had hydroxyapatite phase, but anatase or rutile phases were not found out. TEM image of TiO 2 /HAp product showed that the surface of the plate-shaped HAp particles had a lot of smaller particles which were considered as the compound of Ti. The experimental band gap of TiO 2 /HAp material calculated by the DRS measurement was 3.6 eV, while that of HAp pure was 5.3 eV and that of TiO 2 pure was around 3.2 eV. The shift of the band gap energy of TiO 2 in the range of 3.2–3.6 eV may be related to the shifts of Ti signals of XPS spectrum.
    Type of Medium: Online Resource
    ISSN: 2356-7252 , 2314-5978
    URL: Article
    DOI: 10.1155/2014/283034
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2014
    detail.hit.zdb_id: 2760434-2
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  • 5
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    Online Resource
    Hepatitis B Infection and Mother-to-Child Transmission in Haiphong, Vietnam: A Cohort Study with Implications for Interventions
    Hindawi Limited ; 2020
    In:  BioMed Research International Vol. 2020 ( 2020-08-20), p. 1-12
    Details
    In: BioMed Research International, Hindawi Limited, Vol. 2020 ( 2020-08-20), p. 1-12
    Abstract: Background . There is little data available on HBV infection and mother-to-child transmission (MTCT) in Vietnam. Objective . This study is aimed at assessing the prevalence of HBV infection and the current situation of MTCT in Haiphong, Vietnam. Methods . A transversal survey of 1721 pregnant women followed by an observational prospective cohort study of 183 HBV-infected women was conducted at Haiphong Gyneco-Obstetric Hospital. Women were followed up up to 12-month postpartum; use of prevention measures and the MTCT rate were evaluated. HBV infection in children was defined by a HBsAg-positive test at 12 months of age. Results . At baseline, 183 of 1721 pregnant women (10.6%) tested HBsAg positive. Among them, 23.0% were HBeAg positive, 26.2% had a detectable load of HBV DNA, and 13.1% had a HBV DNA load ≥ 200,000  IU/mL. All women underwent MTCT prevention antiviral therapy. At delivery, 98.9% of newborns receive a HBV vaccine birth dose, and 82% received HBIG. At 12 months of age, 94.7% have received the scheduled HBV vaccines. Eight percent of infants born from followed-up women were HBsAg positive. The mother’s HBeAg-positive status was associated with a higher risk of HBV infection in infants. Conclusion . The HBV prevalence and MTCT rates are high in Haiphong. A strong national plan to increase the access to preventive measures and to monitor results is needed in order to decrease this prevalence.
    Type of Medium: Online Resource
    ISSN: 2314-6133 , 2314-6141
    URL: Article
    DOI: 10.1155/2020/4747965
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2020
    detail.hit.zdb_id: 2698540-8
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  • 6
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    Single-Atom Ni Heterogeneous Catalysts Supported UiO-66 Structure: Synthesis and Catalytic Activities
    Hindawi Limited ; 2021
    In:  Journal of Nanomaterials Vol. 2021 ( 2021-5-19), p. 1-16
    Details
    In: Journal of Nanomaterials, Hindawi Limited, Vol. 2021 ( 2021-5-19), p. 1-16
    Abstract: Herein, the single-atom Ni site heterogeneous catalysts supported by the UiO-66 structure (University of Oslo-66 metal organic framework) were successfully synthesized by a postsynthetic metalation method, where Ni ions are covalently attached to the missing-linker defect sites at zirconium oxide clusters (Zr6O4(OH)4) in as-prepared UiO-66 structure, [Zr6O4(OH)4(BDC)(DMF)10(OH)10] (BDC (benzene-1,4-dicarboxylate), DMF (dimethylformamide)). The structure properties of the catalysts were characterized using powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), N2 adsorption-desorption isotherms (BET), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL). It was found that single-atom Ni heterogeneous catalysts supported by the UiO-66 structure, UiO-66/Ni1.0 [Zr6O4(OH)4(C8H4O4)(DMF)10(OH)8Ni2(OH)2(Cl)2] , showed a sphere-like morphology with a high specific surface area as well as good thermal stability. Specifically, the as-prepared UiO-66/Ni1.0 exhibited the excellent catalytic activity and stability for 4-nitrophenol reduction in terms of low activation energy ( E a = 23.15   kJ   mo l − 1 ), high turnover frequency (76.19 molecules g-1 min-1), and high apparent rate constant ( k app = 0.956 mi n − 1 ). In addition, methylene blue (MB) was also chosen as the organic dye model for catalytic reduction reaction. The k app and TOF for the reduction of MB using UiO-66/Ni1.0 were 0.787 min−1 and 33.89 × 10 20 molecules g−1 min−1, respectively.
    Type of Medium: Online Resource
    ISSN: 1687-4129 , 1687-4110
    URL: Article
    DOI: 10.1155/2021/6648704
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2021
    detail.hit.zdb_id: 2229480-6
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  • 7
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    Adsorption of Arsenate from Aqueous Solution onto Modified Vietnamese Bentonite
    Hindawi Limited ; 2019
    In:  Advances in Materials Science and Engineering Vol. 2019 ( 2019-04-11), p. 1-13
    Details
    In: Advances in Materials Science and Engineering, Hindawi Limited, Vol. 2019 ( 2019-04-11), p. 1-13
    Abstract: In this study, pillared layered clays were prepared by modifying Vietnamese bentonite with polymeric Al and Fe. The obtained materials were characteristic of X-ray diffraction analysis, thermal analysis, and nitrogen adsorption/desorption isotherms. The results indicated that hydroxy-aluminum ([Al 13 O 4 (OH) 24 (H 2 O) 12 ] 7+ ) and poly-hydroxyl-Fe or polyoxo-Fe cations were intercalated into layers of clay, resulting in an increase of d 001 values and of the specific surface areas compared with those of initial bentonite. Modified bentonites were employed to adsorb As(V) from aqueous solution. The adsorption of As(V) was strongly dependent on solution pH, and the maximum adsorption of modified bentonites was obtained in the pH 3.0 for Fe-bentonite and the pH 4.0 for Al-bentonite. The equilibrium adsorption study showed that the data were well fit by the Langmuir isotherm model. The maximum monolayer adsorption capacity of As(V) at 30°C derived from the Langmuir equation was 35.71 mg/g for Al-bentonite and 18.98 mg/g for Fe-bentonite. Adsorption kinetics, thermodynamics, and reusability of modified bentonites have been addressed.
    Type of Medium: Online Resource
    ISSN: 1687-8434 , 1687-8442
    URL: Article
    DOI: 10.1155/2019/2710926
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2019
    detail.hit.zdb_id: 2501025-6
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  • 8
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    Antibacterial Shoe Insole-Coated CuO-ZnO Nanocomposite Synthesized by the Sol-Gel Technique
    Hindawi Limited ; 2020
    In:  Journal of Nanomaterials Vol. 2020 ( 2020-12-17), p. 1-13
    Details
    In: Journal of Nanomaterials, Hindawi Limited, Vol. 2020 ( 2020-12-17), p. 1-13
    Abstract: In this study, CuO-ZnO composite was synthesized via the sol-gel method using oxalic acid to form the medium complex and its applications in antibacterial have been conducted with B. cereus, E. coli, S. aureus, Salmonella, and P. aeruginosa. Then, nanopowder of CuO-ZnO was coated on shoe insoles and their antibacterial effect with S. aureus was tested. The nanocomposite products were characterized by XRD, XPS, SEM, TEM, and UV-Vis. The results showed that the CuO-ZnO composite has the average particle size in a range of 20-50 nm, the point of zero charge of 7.8, and the bandgap of 1.7 eV. XPS result shows the composite structure with Cu2+ in the product. The minimum inhibitory concentration (MIC) of CuO-ZnO nanocomposite was 0.313 mg·mL-1 for S. aureus and Samonella, 0.625 mg·mL-1 for E. coli, and 5 mg·mL-1 for B. cereus and P. aeruginosa. The shoe insoles coated with 0.35 wt.% of CuO-ZnO nanocomposite also had high antibacterial activity against S. aureus, and this antibacterial nanocomposite was implanted durably on the surface of the shoe insoles.
    Type of Medium: Online Resource
    ISSN: 1687-4129 , 1687-4110
    URL: Article
    DOI: 10.1155/2020/8825567
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2020
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  • 9
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    Impact of pharmacist‐initiated educational interventions on improving medication reconciliation practice in geriatric inpatients during hospital admission in Vietnam
    Hindawi Limited ; 2022
    In:  Journal of Clinical Pharmacy and Therapeutics Vol. 47, No. 12 ( 2022-12), p. 2107-2114
    Details
    In: Journal of Clinical Pharmacy and Therapeutics, Hindawi Limited, Vol. 47, No. 12 ( 2022-12), p. 2107-2114
    Type of Medium: Online Resource
    ISSN: 0269-4727 , 1365-2710
    URL: Issue
    URL: Article
    DOI: 10.1111/jcpt.v47.12
    DOI: 10.1111/jcpt.13758
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2022
    detail.hit.zdb_id: 2006678-8
    SSG: 15,3
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  • 10
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    Novel Eco-Friendly Synthesis of Biosilver Nanoparticles as a Colorimetric Probe for Highly Selective Detection of Fe (III) Ions in Aqueous Solution
    Hindawi Limited ; 2021
    In:  Journal of Nanomaterials Vol. 2021 ( 2021-6-5), p. 1-17
    Details
    In: Journal of Nanomaterials, Hindawi Limited, Vol. 2021 ( 2021-6-5), p. 1-17
    Abstract: In this work, an eco-friendly approach for the synthesis of biogenic silver nanoparticles (bio-AgNPs) using botanical extracts in combination with an electrochemical process was carried out. We employed three types of plant extracts, including green tea leaf (GTE), grapefruit peel (GP), and mangosteen peel (MP) extracts to successfully synthesize the bio-AgNPs and optimized the experimental conditions aiming to get the highest synthetic yield. The formation of bio-AgNPs was monitored by UV-Vis spectroscopy via a surface plasmon resonance (SPR) band at about 420–430 nm. Transmission electron microscope (TEM) showed their spherical shape with the size range within 23–55 nm. While X-ray diffraction (XRD) analysis described in detail the crystalline structure of the bio-AgNPs with a face-centered cubic crystal lattice of metallic silver. The chemical bonding and elemental compositions of the bio-AgNPs were determined by Fourier Transform Infrared (FTIR) spectroscopy, in which organic compounds in the natural extracts not only acted as effective reductants but also capping agents for the fabricated bio-AgNPs. The prepared bio-AgNPs exhibited high stability and excellent dispersion for about four months. Based on the linear relationship between obtained SPR band intensity of bio-AgNP GTE in the presence of Fe (III) and concentration of Fe (III) ions, our bio-AgNP GTE can be used to develop a highly selective colorimetric sensor for the determination of Fe (III) ions within a linear range from 1 to 25 μM. According to that, the limit of detection (LOD) was recorded at approximately 0.532 μM, and the quantitative limit (LOQ) was calculated to be 1.77 μM. A detection mechanism was proposed through redox reactions between bio-AgNP GTE and Fe (III) ions. More interestingly, this method was successfully applied for the determination of Fe (III) ions in a lake water sample with percentage recovery of 107-150% and high reproducibility ( RSD = 1.49 % ).
    Type of Medium: Online Resource
    ISSN: 1687-4129 , 1687-4110
    URL: Article
    DOI: 10.1155/2021/5527519
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2021
    detail.hit.zdb_id: 2229480-6
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