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Huyen NTT, Tsakitzidis G, Tam NM, Valcke M, Chuong HV, Wens J. Perceptions and experiences of primary healthcare providers toward interprofessional collaboration in chronic disease management in Hue, Vietnam. J Interprof Care 2024; 38:52-61. [PMID: 37366565 DOI: 10.1080/13561820.2023.2227650] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 04/19/2023] [Accepted: 06/08/2023] [Indexed: 06/28/2023]
Abstract
In Vietnam, each primary care community health center (CHC) consists of a multi-professional team with six disciplines, including a physician, assistant physician, nurse, pharmacist, midwife, and Vietnamese traditional physician, who are able to meet the majority of patient's needs at the primary care level. How they collaborate, especially in chronic disease management (CDM), is still limited described in the literature. This study aims to gain insight into the perceptions and the experiences of primary health care providers (PHCPs) toward interprofessional collaboration (IPC) in CDM in CHCs in (Hue) Vietnam. A qualitative study of descriptive phenomenology was performed using two focus groups and 15 semi-structured interviews with PHCPs from six professions relevant to CDM in CHCs. The data were analyzed using NVivo 12.0 with a thematic analysis method by a multiprofessional research team. From the analysis, the data were classified into three main themes: "lack of collaborative practice," "knowledge," and "facilitators and barriers to IPC." This study provided evidence of the awareness that actual collaboration in daily care is fragmentarily organized and that PHCPs try to finish their tasks within their profession. PHCPs work multiprofessionally and lack shared decision-making in patient-centered care. There is a need to develop an interprofessional education program and training to address these deficiencies in the Vietnamese context to improve interprofessional collaboration in health care.
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Affiliation(s)
- Nguyen Thi Thanh Huyen
- Department of Family Medicine, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam
- Department of Primary and Interdisciplinary Care, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerpen, Belgium
| | - Giannoula Tsakitzidis
- Department of Primary and Interdisciplinary Care, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerpen, Belgium
| | - Nguyen Minh Tam
- Department of Family Medicine, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam
| | - Martin Valcke
- Department of Educational Studies, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Huynh Van Chuong
- The Education Quality Management Agency, Ministry of Education and Training, Vietnam
| | - Johan Wens
- Department of Primary and Interdisciplinary Care, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerpen, Belgium
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2
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Nguyen-Ha BN, Phan Dang CT, Van Duong L, Pham-Ho MP, Nguyen MT, Tam NM. Formation of pyramidal structures through mixing gold and platinum atoms: the Au xPt y2+ clusters with x + y = 10. RSC Adv 2023; 13:32893-32903. [PMID: 38025864 PMCID: PMC10630918 DOI: 10.1039/d3ra06000d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 10/30/2023] [Indexed: 12/01/2023] Open
Abstract
The geometric and electronic structures of a small series of mixed gold and platinum AuxPty2+ clusters, with x + y = 10, were investigated using quantum chemical methods. A consistent tetrahedral pyramid structure emerges, displaying two patterns of structural growth by a notable critical point at y = 5. This affects the clusters' electron population, chemical bonding, and stability. For the Pt-doped Au clusters with y values from 2 to 5, the bonds enable Pt atoms to assemble into symmetric line, triangle, quadrangle, and tetragonal pyramidal Pty blocks, respectively. For the Au-doped Pt clusters, with larger values of y > 5, the structures are more relaxed and the d electrons of Pt atoms become delocalized over more centers, leading to lower symmetry structures. A certain aromaticity arising from delocalization of d electrons over the multi-center framework in the doped Pt clusters contributes to their stability, with Pt102+ at y = 10 exhibiting the highest stability. While the ground electronic state of the neutral platinum atom [Xe]. 4f145d96s1 leads to a triplet state (3D3), the total magnetic moments of AuxPty2+ are large increasing steadily from 0 to 10 μB and primarily located on Pt atoms, corresponding to the increase of the number of Pt atoms from 0 to 10 and significantly enhancing the magnetic moments. An admixture of both Au and Pt atoms thus emerges as an elegant way of keeping a small pyramidal structure but bringing in a high and controllable magnetic moment.
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Affiliation(s)
- Bao-Ngan Nguyen-Ha
- Laboratory for Chemical Computation and Modeling, Institute for Computational Science and Artificial Intelligence, Van Lang University Ho Chi Minh City Vietnam
- Faculty of Applied Technology, School of Technology, Van Lang University Ho Chi Minh City Vietnam
| | - Cam-Tu Phan Dang
- Faculty of Natural Sciences, Duy Tan University Da Nang Vietnam
- Institute of Research and Development, Duy Tan University Da Nang Vietnam
| | - Long Van Duong
- Faculty of Applied Technology, School of Technology, Van Lang University Ho Chi Minh City Vietnam
- Atomic Molecular and Optical Physics Research Group, Science and Technology Advanced Institute, Van Lang University Ho Chi Minh City Vietnam
| | - My Phuong Pham-Ho
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT) 268 Ly Thuong Kiet Street, District 10 Ho Chi Minh City Vietnam
- Vietnam National University Ho Chi Minh City Linh Trung Ward, Thu Duc City Ho Chi Minh City Vietnam
| | - Minh Tho Nguyen
- Laboratory for Chemical Computation and Modeling, Institute for Computational Science and Artificial Intelligence, Van Lang University Ho Chi Minh City Vietnam
- Faculty of Applied Technology, School of Technology, Van Lang University Ho Chi Minh City Vietnam
| | - Nguyen Minh Tam
- Faculty of Basic Sciences, University of Phan Thiet 225 Nguyen Thong Phan Thiet City Binh Thuan Vietnam
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Tam NM, Nguyen TH, Pham MQ, Hong ND, Tung NT, Vu VV, Quang DT, Ngo ST. Upgrading nirmatrelvir to inhibit SARS-CoV-2 Mpro via DeepFrag and free energy calculations. J Mol Graph Model 2023; 124:108535. [PMID: 37295158 PMCID: PMC10233213 DOI: 10.1016/j.jmgm.2023.108535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/23/2023] [Accepted: 05/31/2023] [Indexed: 06/12/2023]
Abstract
The first oral drug for the treatment of COVID-19, Paxlovid, has been authorized; however, nirmatrelvir, a major component of the drug, is reported to be associated with some side effects. Moreover, the appearance of many novel variants raises concerns about drug resistance, and designing new potent inhibitors to prevent viral replication is thus urgent. In this context, using a hybrid approach combining machine learning (ML) and free energy simulations, 6 compounds obtained by modifying nirmatrelvir were proposed to bind strongly to SARS-CoV-2 Mpro. The structural modification of nirmatrelvir significantly enhances the electrostatic interaction free energy between the protein and ligand and slightly decreases the vdW term. However, the vdW term is the most important factor in controlling the ligand-binding affinity. In addition, the modified nirmatrelvir might be less toxic to the human body than the original inhibitor.
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Affiliation(s)
- Nguyen Minh Tam
- Faculty of Basic Sciences, University of Phan Thiet, Phan Thiet City, Binh Thuan, Viet Nam
| | - Trung Hai Nguyen
- Laboratory of Biophysics, Institute for Advanced Study in Technology, Ton Duc Thang University, Ho Chi Minh City, Viet Nam; Faculty of Pharmacy, Ton Duc Thang University, Ho Chi Minh City, Viet Nam
| | - Minh Quan Pham
- Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology, Hanoi, Viet Nam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Viet Nam
| | - Nam Dao Hong
- University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Viet Nam
| | - Nguyen Thanh Tung
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Viet Nam; Institute of Materials Science, Vietnam Academy of Science and Technology, Hanoi, Viet Nam.
| | - Van V Vu
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, Ho Chi Minh City, Viet Nam
| | - Duong Tuan Quang
- Department of Chemistry, Hue University, Thua Thien Hue Province, Hue City, Viet Nam.
| | - Son Tung Ngo
- Laboratory of Biophysics, Institute for Advanced Study in Technology, Ton Duc Thang University, Ho Chi Minh City, Viet Nam; Faculty of Pharmacy, Ton Duc Thang University, Ho Chi Minh City, Viet Nam.
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Phan Dang CT, Tam NM, Huynh TN, Trung NT. Revisiting conventional noncovalent interactions towards a complete understanding: from tetrel to pnicogen, chalcogen, and halogen bond. RSC Adv 2023; 13:31507-31517. [PMID: 37901266 PMCID: PMC10606978 DOI: 10.1039/d3ra06078k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 10/23/2023] [Indexed: 10/31/2023] Open
Abstract
Typical noncovalent interactions, including tetrel (TtB), pnicogen (PniB), chalcogen (ChalB), and halogen bonds (HalB), were systematically re-investigated by modeling the N⋯Z interactions (Z = Si, P, S, Cl) between NH3 - as a nucleophilic, and SiF4, PF3, SF2, and ClF - as electrophilic components, employing highly reliable ab initio methods. The characteristics of N⋯Z interactions when Z goes from Si to Cl, were examined through their changes in stability, vibrational spectroscopy, electron density, and natural orbital analyses. The binding energies of these complexes at CCSD(T)/CBS indicate that NH3 tends to hold tightly most with ClF (-34.7 kJ mol-1) and SiF4 (-23.7 kJ mol-1) to form N⋯Cl HalB and N⋯Si TtB, respectively. Remarkably, the interaction energies obtained from various approaches imply that the strength of these noncovalent interactions follows the order: N⋯Si TtB > N⋯Cl HalB > N⋯S ChalB > N⋯P PniB, that differs the order of their corresponding complex stability. The conventional N⋯Z noncovalent interactions are characterized by the local vibrational frequencies of 351, 126, 167, and 261 cm-1 for TtB, PniB, ChalB, and HalB, respectively. The SAPT2+(3)dMP2 calculations demonstrate that the primary force controlling their strength retains the electrostatic term. Accompanied by the stronger strength of N⋯Si TtB and N⋯Cl HalB, the AIM and NBO results state that they are partly covalent in nature with amounts of 18.57% and 27.53%, respectively. Among various analysis approaches, the force constant of the local N⋯Z stretching vibration is shown to be most accurate in describing the noncovalent interactions.
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Affiliation(s)
- Cam-Tu Phan Dang
- Faculty of Natural Sciences, Duy Tan University Da Nang 550000 Vietnam
- Institute of Research and Development, Duy Tan University Da Nang 550000 Vietnam
| | - Nguyen Minh Tam
- Faculty of Basic Sciences, University of Phan Thiet 225 Nguyen Thong Phan Thiet City Binh Thuan Vietnam
| | - Thanh-Nam Huynh
- Institute of Catalysis Research and Technology, Karlsruhe Institute of Technology Eggenstein-Leopoldshafen 76344 Germany
| | - Nguyen Tien Trung
- Laboratory of Computational Chemistry and Modelling (LCCM), Quy Nhon University Quy Nhon City 590000 Vietnam
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5
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Dan HK, Trung ND, Tam NM, Ha LT, Le Thai N, Thanh TD, Zhou D, Qiu J. The effect of MnCO 3 on the gain coefficient for the 4I 13/2 → 4I 15/2 transition of Er 3+ ions and near-infrared emission bandwidth flatness of Er 3+/Tm 3+/Yb 3+ co-doped barium zinc silicate glasses. RSC Adv 2023; 13:31881-31890. [PMID: 37915440 PMCID: PMC10616754 DOI: 10.1039/d3ra06348h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 10/17/2023] [Indexed: 11/03/2023] Open
Abstract
The roles of Mn2+ ions in the MnCO3 compound, leading to the formation of an Mn2+-Yb3+ dimer and affecting the gain coefficient for the 4I13/2 → 4I15/2 transition of Er3+ ions and near-infrared (NIR) emission bandwidth flatness of Er3+/Tm3+/Yb3+ co-doped in SiO2-ZnO-BaO (SZB) barium zinc silicate glasses, were investigated in this work. The composition of all elements from the original raw materials that exist in the host glasses was determined using energy-dispersive X-ray spectroscopy (EDS). Under the excitation of a 980 nm laser diode (LD), the NIR emission of Er3+/Tm3+/Yb3+-co-doped SZB glasses produced a bandwidth of about 430 nm covering the O, E, and C bands. The effects of Mn2+ ions and the Mn2+-Yb3+ dimer on the gain coefficient for the 4I13/2 → 4I15/2 transition of Er3+ ions and bandwidth flatness of NIR emission of Er3+/Tm3+-co-doped and Er3+/Tm3+/Yb3+-co-doped SZB glasses were also assigned. The optimal molar concentration of Mn2+ ions was determined such that the NIR bandwidth flatness of Er3+/Tm3+/Yb3+-co-doped SZB glasses was the flattest. In addition, the role of Mn2+ ions in reducing the gain coefficient for the 4I13/2 → 4I15/2 transition of Er3+ ions was also calculated and discussed.
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Affiliation(s)
- Ho Kim Dan
- Optical Materials Research Group, Science and Technology Advanced Institute, Van Lang University Ho Chi Minh City Vietnam
- Faculty of Applied Technology, School of Technology, Van Lang University Ho Chi Minh City Vietnam
| | - Nguyen Dinh Trung
- Center for Analysis and Testing, Dalat University Lam Dong Vietnam
- Faculty of Chemistry and Environment, Dalat University Lam Dong Vietnam
| | - Nguyen Minh Tam
- Faculty of Basic Sciences, University of Phan Thiet 225 Nguyen Thong Phan Thiet City Binh Thuan Vietnam
| | - L T Ha
- Institute of Science and Technology, TNU-University of Sciences Thai Nguyen 250000 Vietnam
| | - Nguyen Le Thai
- Faculty of Engineering and Technology, Nguyen Tat Thanh University Ho Chi Minh City Vietnam
| | - Tran Dang Thanh
- Institute of Materials Science, Vietnam Academy of Science and Technology (VAST) 18 Hoang Quoc Viet Hanoi Vietnam
| | - Dacheng Zhou
- Key Laboratory of Advanced Materials of Yunnan Province, Kunming University of Science and Technology Kunming 650093 China
| | - Jianbei Qiu
- Key Laboratory of Advanced Materials of Yunnan Province, Kunming University of Science and Technology Kunming 650093 China
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6
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Huyen NTT, Tam NM, Wens J, Tsakitzidis G, Van Chi L, Anh LHTQ, Len Len CT, Van Chuong H, Huy NVQ, Valcke M. Comparison of students' readiness from six health education programs for interprofessional learning in Vietnam: a cross-sectional study. BMC Med Educ 2023; 23:798. [PMID: 37880693 PMCID: PMC10601104 DOI: 10.1186/s12909-023-04776-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 10/16/2023] [Indexed: 10/27/2023]
Abstract
BACKGROUND Interprofessional education (IPE) is expected to help prepare undergraduate health profession students to collaborate with other healthcare professionals in realising quality of care. Studies stress the necessity of students' readiness for interprofessional learning (IPL) in view of designing IPE programs. The present study aims to determine students' IPL-readiness and looks at related differences in students enrolled in different programs and at different phases in their educational program. METHODS A cross-sectional survey study was set up among 1139 students from six health programs at HueUMP, using the Readiness for Interprofessional Learning Scale (RIPLS). Statistical analysis was performed using Kruskal-Wallis H and Mann-Whitney U tests. RESULTS The overall mean RIPLS score was 68.89. RIPLS scores significantly differed between programs and between phases in the educational programs. Medical students presented a lower readiness level for IPL than students from other programs. In contrast to a significant increase in RIPLS scores of students in the clinical phase in Vietnamese traditional medicine, medicine, and pharmacy, a decrease in RIPLS scores was observed in students in the clinical phase in odonto-stomatology. CONCLUSIONS The differences could be related to differences in educational programs and the study phases in a particular program. These results offer insights to direct the design and implementation of IPE in health education curricula and especially underscore the need to provide IPE throughout the curriculum.
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Affiliation(s)
- Nguyen Thi Thanh Huyen
- Family Medicine Centre, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam
- Department of Primary and Interdisciplinary Care, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Nguyen Minh Tam
- Family Medicine Centre, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam.
| | - Johan Wens
- Department of Primary and Interdisciplinary Care, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Giannoula Tsakitzidis
- Department of Primary and Interdisciplinary Care, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Le Van Chi
- Department of Internal Medicine, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam
| | - Le Ho Thi Quynh Anh
- Family Medicine Centre, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam
| | - Che Thi Len Len
- Family Medicine Centre, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam
| | - Huynh Van Chuong
- The Education Quality Management Agency, Ministry of Education and Training, Hanoi, Vietnam
| | - Nguyen Vu Quoc Huy
- Department of Obstetrics & Gynaecology, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam
| | - Martin Valcke
- Department of Educational Studies, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
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7
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Tam NM, Tran LH, Vo QV, Pham MQ, Phung HTT. Designing Potential Inhibitors of SARS-CoV-2 Mpro Using Deep-Learning and Steered-Molecular Dynamic Simulations. J Comput Biophys Chem 2023. [DOI: 10.1142/s2737416523500242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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8
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Dan HK, Trung ND, Tam NM, Ha LT, Ha CV, Zhou D, Qiu J. Optical band gaps and spectroscopy properties of Bi m+/Eu n+/Yb 3+ co-doped ( m = 0, 2, 3; and n = 2, 3) zinc calcium silicate glasses. RSC Adv 2023; 13:6861-6871. [PMID: 36874941 PMCID: PMC9977400 DOI: 10.1039/d2ra07310b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 02/02/2023] [Indexed: 03/05/2023] Open
Abstract
In this study, the indirect/direct optical band gaps and spectroscopy properties of Bi m+/Eu n+/Yb3+ co-doped (m = 0, 2, 3; and n = 2, 3) zinc calcium silicate glasses under different excitation wavelengths were investigated. Zinc calcium silicate glasses with the main compositions of SiO2-ZnO-CaF2-LaF3-TiO2 were prepared by the conventional melting method. EDS analysis was performed to determine the elemental composition existing in the zinc calcium silicate glasses. Visible (VIS)-, upconversion (UC)-, and near-infrared (NIR)-emission spectra of Bi m+/Eu n+/Yb3+ co-doped glasses were also investigated. Indirect optical band gaps and direct optical band gaps of Bi m+-, Eu n+- single-doped, and Bi m+-Eu n+ co-doped SiO2-ZnO-CaF2-LaF3-TiO2-Bi2O3-EuF3-YbF3 zinc calcium silicate glasses were calculated and analyzed. CIE 1931(x, y) color coordinates for VIS and UC emission spectra of Bi m+/Eu n+/Yb3+ co-doped glasses were determined. Besides, the mechanism of VIS-, UC-, NIR-emissions, and energy transfer (ET) processes between Bi m+ and Eu n+ ions were also proposed and discussed.
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Affiliation(s)
- Ho Kim Dan
- Optical Materials Research Group, Science and Technology Advanced Institute, Van Lang University Ho Chi Minh City Vietnam.,Faculty of Applied Technology, School of Technology, Van Lang University Ho Chi Minh City Vietnam
| | - Nguyen Dinh Trung
- Center for Analysis and Testing, Dalat University Lam Dong Vietnam.,Faculty of Chemistry and Environment, Dalat University Lam Dong Vietnam
| | - Nguyen Minh Tam
- Faculty of Basic Sciences, University of Phan Thiet 225 Nguyen Thong Phan Thiet City Binh Thuan Vietnam
| | - L T Ha
- Institute of Science and Technology, TNU-University of Sciences Thai Nguyen 250000 Vietnam
| | - C V Ha
- Faculty of Physics, TNU-University of Education Thai Nguyen 250000 Vietnam
| | - Dacheng Zhou
- Key Laboratory of Advanced Materials of Yunnan Province, School of Materials Science and Engineering, Kunming University of Science and Technology Kunming 650093 China
| | - Jianbei Qiu
- Key Laboratory of Advanced Materials of Yunnan Province, School of Materials Science and Engineering, Kunming University of Science and Technology Kunming 650093 China
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Nguyen TH, Tam NM, Tuan MV, Zhan P, Vu VV, Quang DT, Ngo ST. Searching for potential inhibitors of SARS-COV-2 main protease using supervised learning and perturbation calculations. Chem Phys 2023; 564:111709. [PMID: 36188488 PMCID: PMC9511900 DOI: 10.1016/j.chemphys.2022.111709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 08/11/2022] [Accepted: 09/21/2022] [Indexed: 11/28/2022]
Abstract
Inhibiting the biological activity of SARS-CoV-2 Mpro can prevent viral replication. In this context, a hybrid approach using knowledge- and physics-based methods was proposed to characterize potential inhibitors for SARS-CoV-2 Mpro. Initially, supervised machine learning (ML) models were trained to predict a ligand-binding affinity of ca. 2 million compounds with the correlation on a test set of R=0.748±0.044. Atomistic simulations were then used to refine the outcome of the ML model. Using LIE/FEP calculations, nine compounds from the top 100 ML inhibitors were suggested to bind well to the protease with the domination of van der Waals interactions. Furthermore, the binding affinity of these compounds is also higher than that of nirmatrelvir, which was recently approved by the US FDA to treat COVID-19. In addition, the ligands altered the catalytic triad Cys145 - His41 - Asp187, possibly disturbing the biological activity of SARS-CoV-2.
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Lan NT, Mai NT, Cuong NT, Van PTH, La DD, Tam NM, Ngo ST, Tung NT. Density Functional Study of Size-Dependent Hydrogen Adsorption on Ag n Cr ( n = 1-12) Clusters. ACS Omega 2022; 7:37379-37387. [PMID: 36312417 PMCID: PMC9607664 DOI: 10.1021/acsomega.2c04107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
Increasing interest has been paid for hydrogen adsorption on atomically controlled nanoalloys due to their potential applications in catalytic processes and energy storage. In this work, we investigate the interaction of H2 with small-sized Ag n Cr (n = 1-12) using density functional theory calculations. It is found that the cluster structures are preserved during the adsorption of H2 either molecularly or dissociatively. Ag3Cr-H2, Ag6Cr-H2, and Ag9Cr-H2 clusters are identified to be relatively more stable from computed binding energies and second-order energy difference. The dissociation of adsorbed H2 on Ag2Cr, Ag3Cr, Ag6Cr, and Ag7Cr clusters is favored both thermodynamically and kinetically. The dissociative adsorption is unlikely to occur because of a considerable energy barrier before reaching the final state for Ag4Cr or due to energetic preferences for n = 1, 5, and 8-12 species. Comprehensive analysis shows that the geometric structure of clusters, the relative electronegativity, and the coordination number of the Cr impurity play a decisive role in determining the preferred adsorption configuration.
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Affiliation(s)
- Ngo Thi Lan
- Institute
of Materials Science and Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi11307, Vietnam
- Institute
of Science and Technology, TNU-University
of Sciences, Tan Thinh Ward, Thai
Nguyen City250000, Vietnam
| | - Nguyen Thi Mai
- Institute
of Materials Science and Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi11307, Vietnam
| | - Ngo Tuan Cuong
- Center
for Computational Science, Hanoi National
University of Education, Hanoi10000, Vietnam
| | - Phung Thi Hong Van
- Hanoi
University of Natural Resources and Environment, Hanoi10000, Vietnam
| | - Duong Duc La
- Institute
of Chemistry and Materials, Hanoi10000, Vietnam
| | - Nguyen Minh Tam
- Laboratory
of Theoretical and Computational Biophysics, Advanced Institute of
Materials Science, Ton Duc Thang University, Ho Chi Minh City72915, Vietnam
- Faculty
of Pharmacy, Ton Duc Thang University, Ho Chi Minh City72915, Vietnam
| | - Son Tung Ngo
- Laboratory
of Theoretical and Computational Biophysics, Advanced Institute of
Materials Science, Ton Duc Thang University, Ho Chi Minh City72915, Vietnam
- Faculty
of Pharmacy, Ton Duc Thang University, Ho Chi Minh City72915, Vietnam
| | - Nguyen Thanh Tung
- Institute
of Materials Science and Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi11307, Vietnam
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Nguyen HT, Cuong NT, Lan NT, Tung NT, Nguyen MT, Tam NM. First-row transition metal doped germanium clusters Ge 16M: some remarkable superhalogens. RSC Adv 2022; 12:13487-13499. [PMID: 35527729 PMCID: PMC9068264 DOI: 10.1039/d1ra08527a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 04/26/2022] [Indexed: 11/21/2022] Open
Abstract
A theoretical study of geometric and electronic structures, stability and magnetic properties of both neutral and anionic Ge16M0/− clusters with M being a first-row 3d transition metal atom, is performed using quantum chemical approaches. Both the isoelectronic Ge16Sc− anion and neutral Ge16Ti that have a perfect Frank–Kasper tetrahedral Td shape and an electron shell filled with 68 valence electrons, emerge as magic clusters with an enhanced thermodynamic stability. The latter can be rationalized by the simple Jellium model. Geometric distortions from the Frank–Kasper tetrahedron of Ge16M having more or less than 68 valence electrons can be understood by a Jahn–Teller effect. Remarkably, DFT calculations reveal that both neutral Ge16Sc and Ge16Cu can be considered as superhalogens as their electron affinities (≥3.6 eV) exceed the value of the halogen atoms and even that of icosahedral Al13. A detailed view of the magnetic behavior of Ge16M0/− clusters shows that the magnetic moments of the atomic metals remain large even when they are quenched upon doping. When M goes from Sc to Zn, the total spin magnetic moment of Ge16M0/− increases steadily and reaches the maximum value of 3 μB with M = Mn before decreasing towards the end of the first-row 3d block metals. Furthermore, the IR spectra of some tetrahedral Ge16M are also predicted. A theoretical study of geometric and electronic structures, stability and magnetic properties of both neutral and anionic Ge16M0/− clusters with M being a first-row 3d transition metal atom, is performed using quantum chemical approaches.![]()
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Affiliation(s)
- Huu Tho Nguyen
- Faculty of Natural Sciences Education, Sai Gon University 273 An Duong Vuong Street Ho Chi Minh City Vietnam
| | - Ngo Tuan Cuong
- Center for Computational Science, Faculty of Chemistry, Hanoi National University of Education Hanoi Vietnam
| | - Ngo Thi Lan
- Institute of Materials Science and Graduate University of Science and Technology, Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Hanoi Vietnam.,Institute of Science and Technology, TNU-University of Sciences Tan Thinh Ward Thai Nguyen City Vietnam
| | - Nguyen Thanh Tung
- Institute of Materials Science and Graduate University of Science and Technology, Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Hanoi Vietnam
| | - Minh Tho Nguyen
- Institute for Computational Science and Technology (ICST) Quang Trung Software City Ho Chi Minh City Vietnam
| | - Nguyen Minh Tam
- Laboratory of Theoretical and Computational Biophysics, Advanced Institute of Materials Science, Ton Duc Thang University Ho Chi Minh City Vietnam .,Faculty of Pharmacy, Ton Duc Thang University Ho Chi Minh City Vietnam
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12
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Lan NT, Mai NT, La DD, Tam NM, Ngo ST, Cuong NT, Dang NV, Phung TT, Tung NT. DFT investigation of Au9M2+ nanoclusters (M = Sc-Ni): The magnetic superatomic behavior of Au9Cr2+. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.139451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Tam NM, Nguyen TH, Ngan VT, Tung NT, Ngo ST. Unbinding ligands from SARS-CoV-2 Mpro via umbrella sampling simulations. R Soc Open Sci 2022; 9:211480. [PMID: 35116157 PMCID: PMC8790385 DOI: 10.1098/rsos.211480] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 12/20/2021] [Indexed: 05/03/2023]
Abstract
The umbrella sampling (US) simulation is demonstrated to be an efficient approach for determining the unbinding pathway and binding affinity to the SARS-CoV-2 Mpro of small molecule inhibitors. The accuracy of US is in the same range as the linear interaction energy (LIE) and fast pulling of ligand (FPL) methods. In detail, the correlation coefficient between US and experiments does not differ from FPL and is slightly smaller than LIE. The root mean square error of US simulations is smaller than that of LIE. Moreover, US is better than FPL and poorer than LIE in classifying SARS-CoV-2 Mpro inhibitors owing to the reciever operating characteristic-area under the curve analysis. Furthermore, the US simulations also provide detailed insights on unbinding pathways of ligands from the binding cleft of SARS-CoV-2 Mpro. The residues Cys44, Thr45, Ser46, Leu141, Asn142, Gly143, Glu166, Leu167, Pro168, Ala191, Gln192 and Ala193 probably play an important role in the ligand dissociation. Therefore, substitutions at these points may change the mechanism of binding of inhibitors to SARS-CoV-2 Mpro.
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Affiliation(s)
- Nguyen Minh Tam
- Computational Chemistry Research Group, Ton Duc Thang University, Ho Chi Minh City, Vietnam
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Trung Hai Nguyen
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
- Laboratory of Theoretical and Computational Biophysics, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Vu Thi Ngan
- Laboratory of Computational Chemistry and Modelling, Department of Chemistry, Quy Nhon University, Quy Nhon, Vietnam
| | - Nguyen Thanh Tung
- Institute of Materials Science, Vietnam Academy of Science and Technology, Hanoi, Vietnam
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Son Tung Ngo
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
- Laboratory of Theoretical and Computational Biophysics, Ton Duc Thang University, Ho Chi Minh City, Vietnam
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14
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Cuong NT, Mai NT, Tung NT, Lan NT, Van Duong L, Nguyen MT, Tam NM. Correction: The binary aluminum scandium clusters Al x Sc y with x + y = 13: when is the icosahedron retained? RSC Adv 2021; 12:719. [PMID: 35427096 PMCID: PMC8978877 DOI: 10.1039/d1ra90178h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 12/20/2021] [Indexed: 11/21/2022] Open
Abstract
Correction for ‘The binary aluminum scandium clusters AlxScy with x + y = 13: when is the icosahedron retained?’ by Ngo Tuan Cuong et al., RSC Adv., 2021, 11, 40072–40084. DOI: 10.1039/D1RA06994B.
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Affiliation(s)
- Ngo Tuan Cuong
- Faculty of Chemistry, Center for Computational Science, Hanoi National University of Education Hanoi Vietnam
| | - Nguyen Thi Mai
- Institute of Materials Science, Graduate University of Science and Technology, Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Hanoi Vietnam
| | - Nguyen Thanh Tung
- Institute of Materials Science, Graduate University of Science and Technology, Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Hanoi Vietnam
| | - Ngo Thi Lan
- Institute of Materials Science, Graduate University of Science and Technology, Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Hanoi Vietnam.,Department of Physics and Technology, Thai Nguyen University of Science Thai Nguyen Vietnam
| | - Long Van Duong
- Institute for Computational Science and Technology (ICST), Quang Trung Software City Ho Chi Minh City Vietnam
| | - Minh Tho Nguyen
- Department of Chemistry, KU Leuven Celestijnenlaan 200F B-3001 Leuven Belgium
| | - Nguyen Minh Tam
- Computational Chemistry Research Group, Ton Duc Thang University Ho Chi Minh City Vietnam .,Faculty of Applied Sciences, Ton Duc Thang University Ho Chi Minh City Vietnam
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15
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Tam NM, Pham DH, Hiep DM, Tran PT, Quang DT, Ngo ST. Searching and designing potential inhibitors for SARS-CoV-2 Mpro from natural sources using atomistic and deep-learning calculations. RSC Adv 2021; 11:38495-38504. [PMID: 35493244 PMCID: PMC9044063 DOI: 10.1039/d1ra06534c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 11/16/2021] [Indexed: 12/15/2022] Open
Abstract
The spread of severe acute respiratory syndrome coronavirus 2 novel coronavirus (SARS-CoV-2) worldwide has caused the coronavirus disease 2019 (COVID-19) pandemic. A hundred million people were infected, resulting in several millions of death worldwide. In order to prevent viral replication, scientists have been aiming to prevent the biological activity of the SARS-CoV-2 main protease (3CL pro or Mpro). In this work, we demonstrate that using a reasonable combination of deep-learning calculations and atomistic simulations could lead to a new approach for developing SARS-CoV-2 main protease (Mpro) inhibitors. Initially, the binding affinities of the natural compounds to SARS-CoV-2 Mpro were estimated via atomistic simulations. The compound tomatine, thevetine, and tribuloside could bind to SARS-CoV-2 Mpro with nanomolar/high-nanomolar affinities. Secondly, the deep-learning (DL) calculations were performed to chemically alter the top-lead natural compounds to improve ligand-binding affinity. The obtained results were then validated by free energy calculations using atomistic simulations. The outcome of the research will probably boost COVID-19 therapy. The hybrid DeepFrag/atomistic simulation approach could lead to a new scheme for developing SARS-CoV-2 3CLpro/Mpro inhibitors.![]()
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Affiliation(s)
- Nguyen Minh Tam
- Computational Chemistry Research Group, Ton Duc Thang University Ho Chi Minh City Vietnam.,Faculty of Applied Sciences, Ton Duc Thang University Ho Chi Minh City Vietnam
| | - Duc-Hung Pham
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center Cincinnati Ohio 45229 USA
| | - Dinh Minh Hiep
- Department of Agriculture and Rural Development Ho Chi Minh City 71007 Vietnam
| | | | - Duong Tuan Quang
- Department of Chemistry, Hue University, Thua Thien Hue Province Hue City Vietnam
| | - Son Tung Ngo
- Faculty of Applied Sciences, Ton Duc Thang University Ho Chi Minh City Vietnam.,Laboratory of Theoretical and Computational Biophysics, Ton Duc Thang University Ho Chi Minh City Vietnam
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16
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Pham TNH, Nguyen TH, Tam NM, Y Vu T, Pham NT, Huy NT, Mai BK, Tung NT, Pham MQ, V Vu V, Ngo ST. Improving ligand-ranking of AutoDock Vina by changing the empirical parameters. J Comput Chem 2021; 43:160-169. [PMID: 34716930 DOI: 10.1002/jcc.26779] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/10/2021] [Accepted: 10/14/2021] [Indexed: 01/09/2023]
Abstract
AutoDock Vina (Vina) achieved a very high docking-success rate, p ^ , but give a rather low correlation coefficient, R , for binding affinity with respect to experiments. This low correlation can be an obstacle for ranking of ligand-binding affinity, which is the main objective of docking simulations. In this context, we evaluated the dependence of Vina R coefficient upon its empirical parameters. R is affected more by changing the gauss2 and rotation than other terms. The docking-success rate p ^ is sensitive to the alterations of the gauss1, gauss2, repulsion, and hydrogen bond parameters. Based on our benchmarks, the parameter set1 has been suggested to be the most optimal. The testing study over 800 complexes indicated that the modified Vina provided higher correlation with experiment R set 1 = 0.556 ± 0.025 compared with R Default = 0.493 ± 0.028 obtained by the original Vina and R Vina 1.2 = 0.503 ± 0.029 by Vina version 1.2. Besides, the modified Vina can be also applied more widely, giving R ≥ 0.500 for 32/48 targets, compared with the default package, giving R ≥ 0.500 for 31/48 targets. In addition, validation calculations for 1036 complexes obtained from version 2019 of PDBbind refined structures showed that the set1 of parameters gave higher correlation coefficient ( R set 1 = 0.617 ± 0.017 ) than the default package ( R Default = 0.543 ± 0.020 ) and Vina version 1.2 ( R Vina 1.2 = 0.540 ± 0.020 ). The version of Vina with set1 of parameters can be downloaded at https://github.com/sontungngo/mvina. The outcomes would enhance the ranking of ligand-binding affinity using Autodock Vina.
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Affiliation(s)
- T Ngoc Han Pham
- Faculty of Pharmacy, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Trung Hai Nguyen
- Laboratory of Theoretical and Computational Biophysics, Ton Duc Thang University, Ho Chi Minh City, Vietnam.,Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Nguyen Minh Tam
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam.,Computational Chemistry Research Group, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Thien Y Vu
- Faculty of Pharmacy, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Nhat Truong Pham
- Faculty of Electrical and Electronics Engineering, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Nguyen Truong Huy
- Faculty of Pharmacy, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Binh Khanh Mai
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Nguyen Thanh Tung
- Institute of Materials Science, Vietnam Academy of Science and Technology, Hanoi, Vietnam.,Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Minh Quan Pham
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam.,Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Van V Vu
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, Ho Chi Minh City, Vietnam
| | - Son Tung Ngo
- Laboratory of Theoretical and Computational Biophysics, Ton Duc Thang University, Ho Chi Minh City, Vietnam.,Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
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17
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Ngo ST, Vu KB, Pham MQ, Tam NM, Tran PT. Marine derivatives prevent wMUS81 in silico studies. R Soc Open Sci 2021; 8:210974. [PMID: 34527278 PMCID: PMC8424343 DOI: 10.1098/rsos.210974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/11/2021] [Indexed: 05/15/2023]
Abstract
The winged-helix domain of the methyl methanesulfonate and ultraviolet-sensitive 81 (wMUS81) is a potential cancer drug target. In this context, marine fungi compounds were indicated to be able to prevent wMUS81 structure via atomistic simulations. Eight compounds such as D197 (Tryptoquivaline U), D220 (Epiremisporine B), D67 (Aspergiolide A), D153 (Preussomerin G), D547 (12,13-dihydroxyfumitremorgin C), D152 (Preussomerin K), D20 (Marinopyrrole B) and D559 (Fumuquinazoline K) were indicated that they are able to prevent the conformation of wMUS81 via forming a strong binding affinity to the enzyme via perturbation approach. The electrostatic interaction is the dominant factor in the binding process of ligands to wMUS81. The residues Trp55, Arg59, Leu62, His63 and Arg69 were found to frequently form non-bonded contacts and hydrogen bonds to inhibitors. Moreover, the influence of the ligand D197, which formed the lowest binding free energy to wMUS81, on the structural change of enzyme was investigated using replica exchange molecular dynamics simulations. The obtained results indicated that D197, which forms a strong binding affinity, can modify the structure of wMUS81. Overall, the marine compounds probably inhibit wMUS81 due to forming a strong binding affinity to the enzyme as well as altering the enzymic conformation.
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Affiliation(s)
- Son Tung Ngo
- Laboratory of Theoretical and Computational Biophysics, Ton Duc Thang University, Ho Chi Minh City, Vietnam
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Khanh B. Vu
- Department of Chemical Engineering, International University, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Minh Quan Pham
- Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology, Hanoi, Vietnam
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Nguyen Minh Tam
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Phuong-Thao Tran
- Department of Pharmaceutical Chemistry, Hanoi University of Pharmacy, Hanoi, Vietnam
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18
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Mai NT, Lan NT, Cuong NT, Tam NM, Ngo ST, Phung TT, Dang NV, Tung NT. Systematic Investigation of the Structure, Stability, and Spin Magnetic Moment of CrM n Clusters (M = Cu, Ag, Au, and n = 2-20) by DFT Calculations. ACS Omega 2021; 6:20341-20350. [PMID: 34395982 PMCID: PMC8358970 DOI: 10.1021/acsomega.1c02282] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
Binary clusters of transition-metal and noble-metal elements have been gathering momentum for not only advanced fundamental understanding but also potential as elementary blocks of novel nanostructured materials. In this regard, the geometries, electronic structures, stability, and magnetic properties of Cr-doped Cu n , Ag n , and Au n clusters (n = 2-20) have been systematically studied by means of density functional theory calculations. It is found that the structural evolutions of CrCu n and CrAg n clusters are identical. The icosahedral CrCu12 and CrAg12 are crucial sizes for doped copper and silver species. Small CrAu n clusters prefer the planar geometries, while the larger ones appear as on the way to establish the tetrahedral CrAu19. Our results show that while each noble atom contributes one s valence electron to the cluster shell, the number of chromium delocalized electrons is strongly size-dependent. The localization and delocalization behavior of 3d orbitals of the chromium decide how they participate in metallic bonding, stabilize the cluster, and give rise to and eventually quench the spin magnetic moment. Moreover, molecular orbital analysis in combination with a qualitative interpretation using the phenomenological shell model is applied to reveal the complex interplay between geometric structure, electronic structure, and magnetic moment of clusters. The finding results are expected to provide greater insight into how a host material electronic structure influences the geometry, stability, and formation of spin magnetic moments in doped systems.
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Affiliation(s)
- Nguyen Thi Mai
- Institute
of Materials Science and Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi 11307, Vietnam
| | - Ngo Thi Lan
- Institute
of Materials Science and Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi 11307, Vietnam
- Department
of Physics and Technology, Thai Nguyen University
of Science, Thai Nguyen 250000, Vietnam
| | - Ngo Tuan Cuong
- Center
for Computational Science, Hanoi National
University of Education, Hanoi 11310, Vietnam
| | - Nguyen Minh Tam
- Computational
Chemistry Research Group, Ton Duc Thang
University, Ho Chi
Minh City 72915, Vietnam
- Faculty
of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City 72915, Vietnam
| | - Son Tung Ngo
- Faculty
of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City 72915, Vietnam
- Laboratory
of Theoretical and Computational Biophysics, Ton Duc Thang University, Ho Chi
Minh City 72915, Vietnam
| | - Thu Thi Phung
- University
of Science and Technology of Hanoi, Vietnam
Academy of Science and Technology, Hanoi 11307, Vietnam
| | - Nguyen Van Dang
- Department
of Physics and Technology, Thai Nguyen University
of Science, Thai Nguyen 250000, Vietnam
| | - Nguyen Thanh Tung
- Institute
of Materials Science and Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi 11307, Vietnam
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19
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Tam NM, Hieu LT, Thong NM, Hoa NT, Hoang LP, Nam PC, Quang DT, Mechler A, Vo QV. Mechanistic and kinetic studies of the radical scavenging activity of natural abietanes: A theoretical insight. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138737] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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20
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Tam NM, Pham MQ, Nguyen HT, Hong ND, Hien NK, Quang DT, Thu Phung HT, Ngo ST. Potential inhibitors for SARS-CoV-2 Mpro from marine compounds. RSC Adv 2021; 11:22206-22213. [PMID: 35480831 PMCID: PMC9034196 DOI: 10.1039/d1ra03852d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 06/18/2021] [Indexed: 12/26/2022] Open
Abstract
Preventing the biological activity of SARS-CoV-2 main protease using natural compounds is of great interest. In this context, using a combination of AutoDock Vina and fast pulling of ligand simulations, eleven marine fungi compounds were identified that probably play as highly potent inhibitors for preventing viral replication. In particular, four compounds including M15 (3-O-(6-O-α-l-arabinopyranosyl)-β-d-glucopyranosyl-1,4-dimethoxyxanthone), M8 (wailupemycins H), M11 (cottoquinazolines B), and M9 (wailupemycins I) adopted the predicted ligand-binding free energy of −9.87, −9.82, −9.62, and −9.35 kcal mol−1, respectively, whereas the other adopted predicted ligand-binding free energies in the range from −8.54 to −8.94 kcal mol−1. The results were obtained using a combination of Vina and FPL simulations. Notably, although, AutoDock4 adopted higher accurate results in comparison with Vina, Vina is proven to be a more suitable technique for rapidly screening ligand-binding affinity with a large database of compounds since it requires much smaller computing resources. Furthermore, FPL is better than Vina to classify inhibitors upon ROC-AUC analysis. Preventing the biological activity of SARS-CoV-2 main protease using natural compounds is of great interest.![]()
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Affiliation(s)
- Nguyen Minh Tam
- Computational Chemistry Research Group, Ton Duc Thang University Ho Chi Minh City Vietnam.,Faculty of Applied Sciences, Ton Duc Thang University Ho Chi Minh City Vietnam
| | - Minh Quan Pham
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology Hanoi Vietnam.,Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology Hanoi Vietnam
| | - Huy Truong Nguyen
- Faculty of Pharmacy, Ton Duc Thang University Ho Chi Minh City Vietnam
| | - Nam Dao Hong
- University of Medicine and Pharmacy at Ho Chi Minh City Ho Chi Minh City Vietnam
| | - Nguyen Khoa Hien
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology Hanoi Vietnam.,Mientrung Institute for Scientific Research, Vietnam Academy of Science and Technology Hue City Thua Thien Hue Province Vietnam
| | - Duong Tuan Quang
- Department of Chemistry, Hue University Hue City Thua Thien Hue Province Vietnam
| | | | - Son Tung Ngo
- Faculty of Applied Sciences, Ton Duc Thang University Ho Chi Minh City Vietnam.,Laboratory of Theoretical and Computational Biophysics, Ton Duc Thang University Ho Chi Minh City Vietnam
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21
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Abstract
The COVID-19 pandemic has killed millions of people worldwide since its outbreak in December 2019. The pandemic is caused by the SARS-CoV-2 virus whose main protease (Mpro) is a promising drug target since it plays a key role in viral proliferation and replication. Currently, developing an effective therapy is an urgent task, which requires accurately estimating the ligand-binding free energy to SARS-CoV-2 Mpro. However, it should be noted that the accuracy of a free energy method probably depends on the protein target. A highly accurate approach for some targets may fail to produce a reasonable correlation with the experiment when a novel enzyme is considered as a drug target. Therefore, in this context, the ligand-binding affinity to SARS-CoV-2 Mpro was calculated via various approaches. The molecular docking approach was manipulated using Autodock Vina (Vina) and Autodock4 (AD4) protocols to preliminarily investigate the ligand-binding affinity and pose to SARS-CoV-2 Mpro. The binding free energy was then refined using the fast pulling of ligand (FPL), linear interaction energy (LIE), molecular mechanics-Poisson-Boltzmann surface area (MM-PBSA), and free energy perturbation (FEP) methods. The benchmark results indicated that for docking calculations, Vina is more accurate than AD4, and for free energy methods, FEP is the most accurate method, followed by LIE, FPL, and MM-PBSA (FEP > LIE ≈ FPL > MM-PBSA). Moreover, atomistic simulations revealed that the van der Waals interaction is the dominant factor. The residues Thr26, His41, Ser46, Asn142, Gly143, Cys145, His164, Glu166, and Gln189 are essential elements affecting the binding process. Our benchmark provides guidelines for further investigations using computational approaches.
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Affiliation(s)
- Son Tung Ngo
- Laboratory of Theoretical and Computational
Biophysics, Ton Duc Thang University, Ho Chi Minh City 700000,
Vietnam
- Faculty of Applied Sciences, Ton Duc
Thang University, Ho Chi Minh City 700000,
Vietnam
| | - Nguyen Minh Tam
- Faculty of Applied Sciences, Ton Duc
Thang University, Ho Chi Minh City 700000,
Vietnam
- Computional Chemistry Research Group, Ton
Duc Thang University, Ho Chi Minh City 700000,
Vietnam
| | - Minh Quan Pham
- Graduate University of Science and Technology,
Vietnam Academy of Science and Technology, Hanoi 100000,
Vietnam
- Institute of Natural Products Chemistry,
Vietnam Academy of Science and Technology, Hanoi 100000,
Vietnam
| | - Trung Hai Nguyen
- Laboratory of Theoretical and Computational
Biophysics, Ton Duc Thang University, Ho Chi Minh City 700000,
Vietnam
- Faculty of Applied Sciences, Ton Duc
Thang University, Ho Chi Minh City 700000,
Vietnam
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22
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Tam NM, Thong NM, Le Huyen T, Hoang LP, Mechler A, Vo QV. The radical scavenging activity of abietane diterpenoids: Theoretical insights. J Mol Graph Model 2021; 105:107892. [PMID: 33743519 DOI: 10.1016/j.jmgm.2021.107892] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 01/15/2021] [Accepted: 03/01/2021] [Indexed: 11/29/2022]
Abstract
Salvia species are frequently used in traditional medicine and are a source of diterpenoid antioxidants. In this study, the hydroperoxide radical scavenging activity of seven known abietane diterpenoids (ADs), isolated from Salvia barrelieri, are investigated using a quantum chemical approach. The ADs are 7-oxoroyleanone-12-methyl ether (1), 7a-acetoxyroyleanone-12-methyl ether (2), royleanone (3), horminone (4), 7-acetylhorminone (5), cryptojaponol (6), and inuroyleanol (7). It was found that formal hydrogen transfer is the main mechanism of the antiradical activity of these ADs in nonpolar environments, whereas the single electron transfer mechanism of anion states is favored in aqueous environment. The antioxidant activity of compounds 1-5 involves H-abstraction at the C7(15)-H bonds whereas for the compounds 6 and 7 the H abstraction takes place at the O12-H bond. The HOO• scavenging activity of compounds 1-5 is minor in all of the studied media, however 6 and 7 exhibit excellent antiradical activity in aqueous solution. Remarkably, the HOO• scavenging activity of compound 7 is substantially higher than that of Trolox, the reference antioxidant: the calculated rate constant was 122.3 times higher in polar and 6.1 times higher in nonpolar environments, respectively. Consistently 7 is a promising radical scavenger in physiological environments.
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Affiliation(s)
- Nguyen Minh Tam
- Computational Chemistry Research Group, Ton Duc Thang University, Ho Chi Minh City, Vietnam; Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Nguyen Minh Thong
- The University of Danang, Campus in Kon Tum, 704 Phan Dinh Phung, Kon Tum, Vietnam
| | - Trinh Le Huyen
- Department of Applied Chemistry and Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Loc Phuoc Hoang
- Institute of Research and Development, Duy Tan University, Danang 550000, Vietnam
| | - Adam Mechler
- Department of Chemistry and Physics, La Trobe University, Victoria 3086, Australia
| | - Quan V Vo
- Faculty of Chemical Technology- Environment, The University of Danang - University of Technology and Education, Danang 550000, Vietnam.
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23
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Trang NV, Tam NM, Dung TN, Nguyen MT. A theoretical design of bipolar host materials for blue phosphorescent OLED. J Mol Graph Model 2021; 105:107845. [PMID: 33588352 DOI: 10.1016/j.jmgm.2021.107845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 01/18/2021] [Accepted: 01/18/2021] [Indexed: 11/29/2022]
Abstract
A series of host molecules have been designed and characterized for use in phosphorescent organic light-emitting diode devices. The parent host molecule was modified by adding nitrogen-containing group at different positions. The first triplet excited (T1) and first singlet excited (S1) states energies, frontier orbital energy levels, reorganization energies and injection barriers of the molecules designed were calculated in comparison to those of the reference host, emitter, hole and electron transport materials. Interestingly, our results suggest that addition of nitrogen group into the dibenzothiophene by a N-C linkage increases the triplet energy separation and decreases the injection barriers making them suitable for use as blue phosphorescent materials.
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Affiliation(s)
- Nguyen Van Trang
- Computational Chemistry Research Group Ton Duc Thang University, Ho Chi Minh City, 700000 Viet Nam; Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, 700000, Viet Nam
| | - Nguyen Minh Tam
- Computational Chemistry Research Group Ton Duc Thang University, Ho Chi Minh City, 700000 Viet Nam; Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, 700000, Viet Nam
| | - Tran Ngoc Dung
- Center for Computational Sciences and Faculty of Chemistry, Hanoi National University of Education, Cau Giay, Hanoi, Viet Nam
| | - Minh Tho Nguyen
- Institute for Computational Science and Technology (ICST), Ho Chi Minh City, Viet Nam.
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Tam NM, Nam PC, Quang DT, Tung NT, Vu VV, Ngo ST. Binding of inhibitors to the monomeric and dimeric SARS-CoV-2 Mpro. RSC Adv 2021; 11:2926-2934. [PMID: 35424256 PMCID: PMC8694027 DOI: 10.1039/d0ra09858b] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/04/2021] [Indexed: 11/29/2022] Open
Abstract
SARS-CoV-2 rapidly infects millions of people worldwide since December 2019. There is still no effective treatment for the virus, resulting in the death of more than one million patients. Inhibiting the activity of SARS-CoV-2 main protease (Mpro), 3C-like protease (3CLP), is able to block the viral replication and proliferation. In this context, our study has revealed that in silico screening for inhibitors of SARS-CoV-2 Mpro can be reliably done using the monomeric structure of the Mpro instead of the dimeric one. Docking and fast pulling of ligand (FPL) simulations for both monomeric and dimeric forms correlate well with the corresponding experimental binding affinity data of 24 compounds. The obtained results were also confirmed via binding pose and noncovalent contact analyses. Our study results show that it is possible to speed up computer-aided drug design for SARS-CoV-2 Mpro by focusing on the monomeric form instead of the larger dimeric one.
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Affiliation(s)
- Nguyen Minh Tam
- Computational Chemistry Research Group, Ton Duc Thang University Ho Chi Minh City Vietnam
- Faculty of Applied Sciences, Ton Duc Thang University Ho Chi Minh City Vietnam
| | - Pham Cam Nam
- Department of Chemistry, The University of Danang, University of Science and Technology Danang Vietnam
| | | | - Nguyen Thanh Tung
- Institute of Materials Science, Vietnam Academy of Science and Technology Hanoi Vietnam
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology Hanoi Vietnam
| | - Van V Vu
- NTT Hi-Tech Institute, Nguyen Tat Thanh University Ho Chi Minh City Vietnam
| | - Son Tung Ngo
- Faculty of Applied Sciences, Ton Duc Thang University Ho Chi Minh City Vietnam
- Laboratory of Theoretical and Computational Biophysics, Ton Duc Thang University Ho Chi Minh City Vietnam
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Cuong NT, Mai NT, Tung NT, Lan NT, Duong LV, Nguyen MT, Tam NM. The binary aluminum scandium clusters Al xSc y with x + y = 13: when is the icosahedron retained? RSC Adv 2021; 11:40072-40084. [PMID: 35494155 PMCID: PMC9044545 DOI: 10.1039/d1ra06994b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 12/24/2021] [Accepted: 12/07/2021] [Indexed: 11/27/2022] Open
Abstract
Geometrical and electronic structures of the 13-atom clusters AlxScy with x + y = 13, as well as their thermodynamic stabilities were investigated using DFT calculations. Both anionic and neutral isomers of AlxScy were found to retain an icosahedral shape of both Al13 and Sc13 systems in which an Al atom occupies the endohedral central position of the icosahedral cage, irrespective of the number of Al atoms present. Such a phenomenon occurs to maximize the number of stronger Al–Al and Sc–Al bonds instead of the weaker Sc–Sc bonds. NBO analyses were applied to examine their electron configurations and rationalize the large number of open shells and thereby high multiplicities of the mixed clusters having more than three Sc atoms. The SOMOs are the molecular orbitals belonged to the irreducible representations of the symmetry point group of the clusters studied, rather than to the cluster electron shells. Evaluation of the average binding energies showed that the thermodynamic stability of AlxScy clusters is insignificantly altered as the number y goes from 0 to 7 and then steadily decreases when y attains the 7–13 range. Increase of the Sc atom number also reduces the electron affinities of the binary AlxScy clusters, and thus they gradually lose the superhalogen characteristics with respect to the pure Al13. The icosahedral structure of the AlxScy clusters with x + y = 13.![]()
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Affiliation(s)
- Ngo Tuan Cuong
- Faculty of Chemistry, Center for Computational Science, Hanoi National University of Education, Hanoi, Vietnam
| | - Nguyen Thi Mai
- Institute of Materials Science, Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc, Hanoi Vietnam
| | - Nguyen Thanh Tung
- Institute of Materials Science, Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc, Hanoi Vietnam
| | - Ngo Thi Lan
- Institute of Materials Science, Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc, Hanoi Vietnam
- Department of Physics and Technology, Thai Nguyen University of Science, Thai Nguyen, Vietnam
| | - Long Van Duong
- Institute for Computational Science and Technology (ICST), Quang Trung Software City, Ho Chi Minh City, Vietnam
| | - Minh Tho Nguyen
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Nguyen Minh Tam
- Computational Chemistry Research Group, Ton Duc Thang University, Ho Chi Minh City, Vietnam
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
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Tam NM, Pham MQ, Ha NX, Nam PC, Phung HTT. Computational estimation of potential inhibitors from known drugs against the main protease of SARS-CoV-2. RSC Adv 2021; 11:17478-17486. [PMID: 35479689 PMCID: PMC9032918 DOI: 10.1039/d1ra02529e] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 05/03/2021] [Indexed: 12/20/2022] Open
Abstract
The coronavirus disease (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread worldwide recently, leading to global social and economic disruption. Although the emergently approved vaccine programs against SARS-CoV-2 have been rolled out globally, the number of COVID-19 daily cases and deaths has remained significantly high. Here, we attempt to computationally screen for possible medications for COVID-19 via rapidly estimating the highly potential inhibitors from an FDA-approved drug database against the main protease (Mpro) of SARS-CoV-2. The approach combined molecular docking and fast pulling of ligand (FPL) simulations that were demonstrated to be accurate and suitable for quick prediction of SARS-CoV-2 Mpro inhibitors. The results suggested that twenty-seven compounds were capable of strongly associating with SARS-CoV-2 Mpro. Among them, the seven top leads are daclatasvir, teniposide, etoposide, levoleucovorin, naldemedine, cabozantinib, and irinotecan. The potential application of these drugs in COVID-19 therapy has thus been discussed. Approved drugs predicted to interact with critical residues in the substrate-binding site of SARS-CoV-2 Mpro can be promising inhibitors.![]()
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Affiliation(s)
- Nguyen Minh Tam
- Computational Chemistry Research Group
- Ton Duc Thang University
- Ho Chi Minh City
- Vietnam
- Faculty of Applied Sciences
| | - Minh Quan Pham
- Institute of Natural Products Chemistry
- Vietnam Academy of Science and Technology
- Hanoi
- Vietnam
- Graduate University of Science and Technology
| | - Nguyen Xuan Ha
- Faculty of Chemistry and Environment
- Thuyloi University
- Ministry of Agriculture and Rural Development
- Hanoi
- Vietnam
| | - Pham Cam Nam
- Department of Chemical Engineering
- The University of Da Nang
- University of Science and Technology
- Da Nang City
- Vietnam
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Hoa NT, Derese A, Peersman W, Markuns JF, Willems S, Tam NM. Primary care quality in Vietnam: Perceptions and opinions of primary care physicians in commune health centers - a mixed-methods study. PLoS One 2020; 15:e0241311. [PMID: 33119666 PMCID: PMC7595414 DOI: 10.1371/journal.pone.0241311] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 10/12/2020] [Indexed: 11/21/2022] Open
Abstract
Introduction Measuring the performance of a primary care system is one of the very first steps to find out whether there is room for improvement. To obtain an objective and comprehensive view, this measurement should come from both the supply and demand sides of the system. Patients’ experiences of primary care have been studied around the world, but much less energy has been invested in researching providers’ perspectives. This research aims to explore how primary care physicians working at commune health centers in Vietnam evaluate their performance and their opinions on how to improve the quality of primary care services. Materials and methods First, a quantitative study was conducted using the validated Vietnamese PCAT questionnaire—provider expanded version (VN PCAT PE) targeting all primary care physicians (PCPs) working at commune health centers in a province of Central Vietnam. Next, a qualitative study was carried out, consisting of in-depth interviews with PCPs, to better understand the results of the quantitative survey and gain insight on barriers of primary care services and how to overcome them. Results In the quantitative portion of our study, 150 PCPs rated the quality of ongoing care and first contact in CHCs as the best (3.09 and 3.11 out of 4, respectively), and coordination as the worst performing core domain (2.53). Twenty-two PCPs also participated in our qualitative research. In regards to challenges that primary care physicians face during their daily practice, three central themes emerged: 1) patient factors such as client attitude and knowledge, 2) provider factors such as the burden of administrative work and lack of training opportunities, and 3) contextual factors such as low income and lack of resources including medicines and diagnostics. Participants recommended more health promotion campaigns in the media, increasing the number of services available at CHCs (such as being able to take blood samples), reducing the workload related to administration for CHC leaders, greater government subsidies, and providing more training courses for PCPs. Conclusions Findings from this study offer a valuable view from the supply-side of the primary care system, specifically those who directly deliver primary care services. Along with the earlier study on consumers’ evaluation of the Vietnamese primary care system, and literature from other low and middle-income countries, these findings offer emerging evidence for policymakers to improve the quality of primary care in Vietnam.
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Affiliation(s)
- Nguyen Thi Hoa
- Department of Family Medicine, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam
- Department of Public Health and Primary Care, Ghent University, Gent, Belgium
- * E-mail: (NMT); (NTH)
| | - Anselme Derese
- Department of Public Health and Primary Care, Ghent University, Gent, Belgium
| | - Wim Peersman
- Research Group Social and Community Work, Odisee University College, Brussel, Belgium
- Department of Rehabilitation Sciences, Ghent University, Gent, Belgium
| | - Jeffrey F. Markuns
- Global Health Collaborative, Department of Family Medicine, Boston University, Boston, MA, United States of America
| | - Sara Willems
- Department of Public Health and Primary Care, Ghent University, Gent, Belgium
| | - Nguyen Minh Tam
- Department of Family Medicine, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam
- * E-mail: (NMT); (NTH)
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Vo QV, Thong NM, Le Huyen T, Nam PC, Tam NM, Hoa NT, Mechler A. A thermodynamic and kinetic study of the antioxidant activity of natural hydroanthraquinones. RSC Adv 2020; 10:20089-20097. [PMID: 35520421 PMCID: PMC9054120 DOI: 10.1039/d0ra04013d] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 05/15/2020] [Indexed: 11/21/2022] Open
Abstract
Novel hydroanthraquinones isolated from marine algal-derived endophytic fungus Talaromyces islandicus EN-501 exhibited promising antioxidant properties in preliminary studies, raising the prospect of adapting these compounds for therapeutic use in diseases caused by oxidative stress. For medicinal applications it is beneficial to develop a full understanding of the antioxidant activity of these compounds. In this study, the hydroperoxide radical scavenging activity of five natural hydroanthraquinones was evaluated by kinetic and thermodynamic calculations. The results showed that the radical scavenging of these hydroanthraquinones in the gas phase and in lipid solvents was defined by the formal hydrogen transfer mechanism, that for the polar environments was decided by the sequential proton loss electron transfer pathway. The hydroanthraquinones exhibited good hydroperoxide scavenging activity in both polar and non-polar media. The overall rate constant values for the radical scavenging reaction were in the range of 3.42 × 101 to 2.60 × 105 M-1 s-1 and 3.80 × 106 to 5.87 × 107 M-1 s-1 in pentyl ethanoate and water solvents, respectively. Thus the activity of 8-hydroxyconiothyrinone B (1) is about 2.6 and 444.6 times higher than that of Trolox in the studied solvents, identifying 8-hydroxyconiothyrinone B as a promising antioxidant.
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Affiliation(s)
- Quan V Vo
- Institute of Research and Development, Duy Tan University Danang 550000 Vietnam
| | - Nguyen Minh Thong
- The University of Danang, Campus in Kon Tum 704 Phan Dinh Phung Kon Tum Vietnam
| | - Trinh Le Huyen
- Department of Applied Chemistry, National Chiao Tung University Hsinchu 30010 Taiwan
- Department of Chemical Engineering, The University of Danang, University of Science and Technology Danang 550000 Vietnam
| | - Pham Cam Nam
- Department of Chemical Engineering, The University of Danang, University of Science and Technology Danang 550000 Vietnam
| | - Nguyen Minh Tam
- Computational Chemistry Research Group, Ton Duc Thang University Ho Chi Minh City Vietnam
- Faculty of Applied Sciences, Ton Duc Thang University Ho Chi Minh City Vietnam
| | - Nguyen Thi Hoa
- Academic Affairs, The University of Danang-University of Technology and Education 48 Cao Thang Da Nang 550000 Vietnam
| | - Adam Mechler
- Department of Chemistry and Physics, La Trobe University Victoria 3086 Australia
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Abstract
The antioxidant activity of hydralazine derivatives in the gas-phase and in physiological environments were examined by thermodynamic and kinetic calculations.
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Affiliation(s)
- Houssem Boulebd
- Laboratory of Synthesis of Molecules with Biological Interest
- University of Frères Mentouri Constantine 1
- Constantine
- Algeria
| | - Nguyen Minh Tam
- Computational Chemistry Research Group
- Ton Duc Thang University
- Ho Chi Minh City
- Vietnam
- Faculty of Applied Sciences
| | - Adam Mechler
- Department of Chemistry and Physics
- La Trobe University
- Victoria 3086
- Australia
| | - Quan V. Vo
- Institute of Research and Development
- Duy Tan University
- Danang 550000
- Vietnam
- The University of Danang-University of Technology and Education
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Pham HT, Phan CTD, Nguyen MT, Tam NM. A remarkable mixture of germanium with phosphorus and arsenic atoms making stable pentagonal hetero-prisms [M@Ge5E5]+, E = P, As and M = Fe, Ru, Os. RSC Adv 2020; 10:19781-19789. [PMID: 35520435 PMCID: PMC9054236 DOI: 10.1039/d0ra01316a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 05/12/2020] [Indexed: 01/11/2023] Open
Abstract
A pentagonal hetero-prismatic structural motif was found for singly transition metal doped M@Ge5E5+ clusters, where the transition metal atom is located at the centre of a (5/5) Ge5E5 prism in which Ge is mixed with either P or As atoms. Structural characterization indicates that each (5/5) Ge5E5 prism is established by joining of two Ge3E2 and Ge2E3 strings in a prismatic fashion rather than two Ge5 and E5 strings. Each string results from a remarkable mixture of Ge and E atoms and contains only one E–E connection due to the fact that Ge–E bonds are much stronger than E–E connections. From the donor–acceptor perspective, the Ge5E5 tube donates electrons to the M center, which behaves as an acceptor. NBO atomic charge and ELI_D analyses demonstrate such electrostatic interactions of the M dopant with a Ge5E5+ tube which likely induce thermodynamic stability for the resulting M@Ge5E5+ cluster. CMO analysis illustrates that the conventional 18 electron count is recovered in the M@Ge5E5+ cations. Geometric shape of the lowest-energy structure M@Ge5E5+.![]()
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Affiliation(s)
- Hung Tan Pham
- Department of Chemistry
- KU Leuven
- B-3001 Leuven
- Belgium
| | - Cam-Tu Dang Phan
- Laboratory of Computational Chemistry and Modelling
- Quy Nhon University
- Quy Nhon
- Vietnam
| | - Minh Tho Nguyen
- Institute for Computational Science and Technology (ICST)
- Ho Chi Minh City
- Vietnam
| | - Nguyen Minh Tam
- Computational Chemistry Research Group
- Ton Duc Thang University
- Ho Chi Minh City
- Vietnam
- Faculty of Applied Sciences
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Abstract
Highlight of experimental and computational studies about the interaction of CO with transition and coinage metal clusters, particularly discussing the influence of dopant atoms.
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Affiliation(s)
- Piero Ferrari
- Quantum Solid-State Physics
- Department of Physics and Astronomy
- KU Leuven
- 3001 Leuven
- Belgium
| | - Guillaume Libeert
- Quantum Solid-State Physics
- Department of Physics and Astronomy
- KU Leuven
- 3001 Leuven
- Belgium
| | - Nguyen Minh Tam
- Computational Chemistry Research Group & Faculty of Applied Sciences
- Ton Duc Thang University
- Ho Chi Minh City
- Vietnam
| | - Ewald Janssens
- Quantum Solid-State Physics
- Department of Physics and Astronomy
- KU Leuven
- 3001 Leuven
- Belgium
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Vo QV, Tam NM, Hieu LT, Van Bay M, Thong NM, Le Huyen T, Hoa NT, Mechler A. The antioxidant activity of natural diterpenes: theoretical insights. RSC Adv 2020; 10:14937-14943. [PMID: 35497147 PMCID: PMC9052119 DOI: 10.1039/d0ra02681f] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 04/02/2020] [Indexed: 01/18/2023] Open
Abstract
Diterpenes that were isolated from Crossopetalum gaumeri (Loes.) Lundell (Celastraceae) plants are reported to exhibit a range of biological activities, in particular as radical scavengers. Thus further insight into the antioxidant activity of diterpenes in physiological environments is much needed but not studied yet. In this study, the antioxidant activity of nine natural diterpenes was evaluated using kinetic and thermodynamic calculations. It was found that the sequential proton loss electron transfer (SPLET) mechanism is favored in polar environments, whereas formal hydrogen transfer (FHT) is the main pathway for the radical scavenging of these diterpenes in the gas phase as well as in lipid media. The rate constants for the HOO˙ radical scavenging of these compounds in the gas phase, polar and nonpolar solvents are in the range of 2.29 × 10−2 to 4.58 × 107, 9.74 × 10−3 to 1.67 × 108 and 3.54 × 10−5 to 1.31 × 105 M−1 s−1, respectively. 7-Deoxynimbidiol (6), exhibits the highest HOO˙ radical scavenging with koverall = 1.69 × 108 M−1 s−1 and 9.10 × 104 M−1 s−1 in water and pentyl ethanoate solvents, respectively, that is about 1300 times higher than that of Trolox in polar environments. It is thus a promising natural antioxidant in physiological environments. Diterpenes that were isolated from Crossopetalum gaumeri (Loes.) Lundell (Celastraceae) plants are reported to exhibit a range of biological activities, in particular as radical scavengers.![]()
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Affiliation(s)
- Quan V. Vo
- Institute of Research and Development
- Duy Tan University
- Danang 550000
- Vietnam
- Faculty of Chemical Technology - Environment
| | - Nguyen Minh Tam
- Computational Chemistry Research Group
- Ton Duc Thang University
- Ho Chi Minh City
- Vietnam
- Faculty of Applied Sciences
| | - Le Trung Hieu
- University of Sciences-Hue University
- Hue 530000
- Vietnam
| | - Mai Van Bay
- Department of Chemistry
- The University of Danang-
- University of Science and Education
- Danang 550000
- Vietnam
| | | | - Trinh Le Huyen
- Department of Applied Chemistry
- National Chiao Tung University
- Hsinchu 30010
- Taiwan
- Department of Chemical Engineering
| | - Nguyen Thi Hoa
- Academic Affairs
- The University of Danang-University of Technology and Education
- Danang 550000
- Vietnam
| | - Adam Mechler
- Department of Chemistry and Physics
- La Trobe University
- Victoria 3086
- Australia
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Hoa NT, Tam NM, Derese A, Markuns JF, Peersman W. Patient experiences of primary care quality amongst different types of health care facilities in central Vietnam. BMC Health Serv Res 2019; 19:275. [PMID: 31046750 PMCID: PMC6498623 DOI: 10.1186/s12913-019-4089-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 04/09/2019] [Indexed: 11/24/2022] Open
Abstract
Background Patient experience with primary health care services can vary markedly between different types of health care facilities, even within the same country setting. Given known benefits of high quality primary health care, the performance of these facilities may significantly impact population health. The aim of this study was to compare the quality of primary care in different types of health facilities as experienced by Vietnamese consumers. Methods 1662 people who utilized primary health care services at least once over the past two years in various types of facilities in central Vietnam were surveyed in a cross-sectional study using the Vietnamese version of the Primary Care Assessment Tool (VN PCAT-AE) to assess overall primary care quality as well as several different domains of high quality primary care services. Results Commune health centers were associated with the highest overall primary care quality (PCAT expanded score 21.07, p < 0.001) as well as high scores in nearly all individual domains of primary care quality experienced by consumers compared with other types of facilities. Conversely, private facilities such as private clinics and pharmacies were rated lowest overall (PCAT expanded score 18.45, p < 0.05 and 16.90, p < 0.001 respectively). District hospitals and other government hospitals (PCAT expanded score 20.10 and 19.72 respectively) were reported as the best quality in comprehensiveness of available services (p < 0.001). Polyclinics performed quite well in comprehensiveness of services available (3.11) and first contact-access (2.79) but less so in other domains, especially in cultural competency (1.87). Conclusions The high quality of primary care services experienced by consumers in commune health centers compared with other facilities gives Vietnam ample reason to promote greater use of these community-based primary care facilities. Populations may benefit most from building and strengthening grassroots networks of such community-based health centers as an effective solution for overcrowding at hospitals while simultaneously providing better overall health outcomes. Electronic supplementary material The online version of this article (10.1186/s12913-019-4089-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nguyen Thi Hoa
- Department of Family Medicine, Hue University of Medicine and Pharmacy, Hue University, 06 Ngo Quyen street, Hue, Vietnam.,Department of Public Health and Primary Care, Campus UZ 6K3, C.Heymanslaan 10, B-9000, Ghent, Belgium
| | - Nguyen Minh Tam
- Department of Family Medicine, Hue University of Medicine and Pharmacy, Hue University, 06 Ngo Quyen street, Hue, Vietnam.
| | - Anselme Derese
- Department of Public Health and Primary Care, Campus UZ 6K3, C.Heymanslaan 10, B-9000, Ghent, Belgium
| | - Jeffrey F Markuns
- Global Health Collaborative, Department of Family Medicine, Boston University, Boston, MA, 02118, USA
| | - Wim Peersman
- Research Group Social Work, Odisee University College, Warmoesberg 26, B-1000, Brussel, Belgium.,Department of Rehabilitation Sciences, Ghent University, Campus UZ, C. Heymanslaan 10, B-9000, Ghent, Belgium
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Tam NM, Duong LV, Cuong NT, Nguyen MT. Structure, stability, absorption spectra and aromaticity of the singly and doubly silicon doped aluminum clusters AlnSim0/+ with n = 3–16 and m = 1, 2. RSC Adv 2019; 9:27208-27223. [PMID: 35529187 PMCID: PMC9070575 DOI: 10.1039/c9ra04004h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 08/21/2019] [Indexed: 11/22/2022] Open
Abstract
Structures of the binary AlnSim clusters in both neutral and cationic states were investigated using DFT and TD-DFT (B3LYP/6-311+G(d)) and (U)CCSD(T)/cc-pvTZ calculations. Silicon-doped aluminum clusters are characterized by low spin ground states. For small sizes, the Si dopant prefers to be located at vertices having many edges. For larger sizes, the Si atom prefers to be endohedrally doped inside an Aln cage. Relative stability, adiabatic ionization energy and dissociation energies of each cluster size were evaluated. A characteristic of most Si doped Al clusters is the energetic degeneracy of two lowest-lying isomers. Calculated results confirm the high stability of the sizes Al4Si2, Al12Si and Al11Si2+ as “magic” clusters, that exhibit 20 or 40 shell electrons and are thermodynamically more stable as compared to their neighbors. Electronic absorption spectra of isoelectronic magic clusters Al13−, Al12Si, and Al11Si2+ that have two pronounced bands corresponding to blue and violet lights, have been rationalized by using the electron shell model. The magnetically included ring current density (MICD) analyses suggest that they are also aromatic structures as a result of the “magic” 40 shell electrons. The isoelectronic “magic” clusters with 40 shell electrons have enhanced thermochemical stability. ![]()
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Affiliation(s)
- Nguyen Minh Tam
- Computational Chemistry Research Group
- Ton Duc Thang University
- Ho Chi Minh City
- Vietnam
- Faculty of Applied Sciences
| | - Long Van Duong
- Institute for Computational Science and Technology (ICST)
- Ho Chi Minh City
- Vietnam
| | - Ngo Tuan Cuong
- Faculty of Chemistry and Center for Computational Science
- Hanoi National University of Education
- Hanoi
- Vietnam
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Tam NM, Duong LV, Pham HT, Nguyen MT, Pham-Ho MP. Effects of single and double nickel doping on boron clusters: stabilization of tubular structures in BnNim, n = 2–22, m = 1, 2. Phys Chem Chem Phys 2019; 21:8365-8375. [DOI: 10.1039/c9cp00762h] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A systematic investigation on structure, relative stabilities, dissociation behavior and bonding of the singly and doubly Ni doped boron clusters BnNim with n = 2–22 and m = 1–2, was carried out using density functional theory (TPSSh functional) calculations.
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Affiliation(s)
- Nguyen Minh Tam
- Computational Chemistry Research Group
- Ton Duc Thang University
- Ho Chi Minh City
- Vietnam
- Faculty of Applied Sciences
| | - Long Van Duong
- Institute for Computational Science and Technology (ICST)
- Quang Trung Software City
- Ho Chi Minh City
- Vietnam
| | - Hung Tan Pham
- Department of Chemistry
- KU Leuven
- B-3001 Leuven
- Belgium
| | | | - My Phuong Pham-Ho
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology
- Ho Chi Minh City
- Vietnam
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Tam NM, Vu KB, Vu VV, Ngo ST. Influence of various force fields in estimating the binding affinity of acetylcholinesterase inhibitors using fast pulling of ligand scheme. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.04.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Pham HT, Dang TTM, Van Duong L, Tam NM, Nguyen MT. B 3@Si 12+: strong stabilizing effects of a triatomic cyclic boron unit on tubular silicon clusters. Phys Chem Chem Phys 2018; 20:7588-7592. [PMID: 29493696 DOI: 10.1039/c8cp00380g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Remarkably strong effects of the aromatic B3 cycle in stabilizing tubular silicon clusters were observed for the first time. The doped cluster B3@Si12+ presents a novel structural motif for silicon clusters in which a B3 cycle is encapsulated into a (6 × 2) Si12 prism giving rise to a high symmetry stable tubular structure (D3h). A large amount of electron density is transferred to the boron cycle, and the B3δ- unit not only retains a delocalized bonding pattern within the Si12 prism but also enables a two-fold aromaticity for the resulting silicon double ring. This double ring can be used as a building block to make longer nanotubes.
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Affiliation(s)
- Hung Tan Pham
- Institute for Computational Science and Technology (ICST), Ho Chi Minh City, Vietnam
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Hoa NT, Tam NM, Peersman W, Derese A, Markuns JF. Development and validation of the Vietnamese primary care assessment tool. PLoS One 2018; 13:e0191181. [PMID: 29324851 PMCID: PMC5764365 DOI: 10.1371/journal.pone.0191181] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 12/31/2017] [Indexed: 11/19/2022] Open
Abstract
Objective To adapt the consumer version of the Primary Care Assessment Tool (PCAT) for Vietnam and determine its internal consistency and validity. Design A quantitative cross sectional study. Setting 56 communes in 3 representative provinces of central Vietnam. Participants Total of 3289 people who used health care services at health facility at least once over the past two years. Results The Vietnamese adult expanded consumer version of the PCAT (VN PCAT-AE) is an instrument for evaluation of primary care in Vietnam with 70 items comprising six scales representing four core primary care domains, and three additional scales representing three derivative domains. Sixteen other items from the original tool were not included in the final instrument, due to problems with missing values, floor or ceiling effects, and item-total correlations. All the retained scales have a Cronbach’s alpha above 0.70 except for the subscale of Family Centeredness. Conclusions The VN PCAT-AE demonstrates adequate internal consistency and validity to be used as an effective tool for measuring the quality of primary care in Vietnam from the consumer perspective. Additional work in the future to optimize valid measurement in all domains consistent with the original version of the tool may be helpful as the primary care system in Vietnam further develops.
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Affiliation(s)
- Nguyen Thi Hoa
- Department of Family Medicine, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam
- Department of Family Medicine and Primary Healthcare, Ghent University, Ghent, Belgium
- * E-mail:
| | - Nguyen Minh Tam
- Department of Family Medicine, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam
| | - Wim Peersman
- Social and Community Work, Odisee University College, Brussels, Belgium
| | - Anselme Derese
- Department of Family Medicine and Primary Healthcare, Ghent University, Ghent, Belgium
| | - Jeffrey F. Markuns
- Global Health Collaborative, Department of Family Medicine, Boston University, Boston, Massachusetts, United States of America
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Abstract
An investigation on structure, stability, and magnetic properties of singly doped Au19M (M=Cr, Mn, and Fe) clusters is carried out by means of density functional theory calculations. The studied clusters prefer forming magnetic versions of the unique tetrahedral Au20. Stable sextet Au19Cr is identified as the least reactive species and can be qualified as a magnetic superatom. Analysis on cluster electronic structures shows that the competition between localized and delocalized electronic states governs the stability and magnetic properties of Au19M clusters.
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Affiliation(s)
- Nguyen Minh Tam
- Computational Chemistry Research Group, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
| | - Ngo Tuan Cuong
- Faculty of Chemistry and Center for Computational Science, Hanoi National University of Education, Hanoi, Vietnam
| | - Hung Tan Pham
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001, Leuven, Belgium
| | - Nguyen Thanh Tung
- Institute of Materials Science and Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam.
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Pham HT, Tam NM, Jeilani YA, Nguyen MT. Structural evolution and bonding of phosphorus-doped silicon clusters SinPm−/0/+ with n = 1–10, m = 1, 2. COMPUT THEOR CHEM 2017. [DOI: 10.1016/j.comptc.2017.01.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Duc NM, Duy VD, Xuan BTT, Thang BV, Ha NTH, Tam NM. Genetic structure of the threatened Dipterocarpus costatus populations in lowland tropical rainforests of southern Vietnam. Genet Mol Res 2016; 15:gmr-15-gmr15048821. [PMID: 27813581 DOI: 10.4238/gmr15048821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Dipterocarpus costatus is an endangered species restricted to the lowland forests of southern Vietnam. Habitat loss and over-exploitation of D. costatus wood are the major threats to this species. We investigated the level of genetic variability within and among populations of D. costatus in order to provide guidelines for the conservation, management, and restoration of this species to the Forest Protection Department, Vietnam. Nine microsatellite markers were used to analyze 114 samples from four populations representing the natural range of D. costatus in southeast Vietnam. We indicated the low allelic diversity (NA = 2.3) and low genetic diversities with an average observed and expected heterozygosity of 0.130 and 0.151, respectively, in the lowland forests of southeast Vietnam. The low genetic diversity might be a consequence of inbreeding within the small and isolated populations of D. costatus owing to its habitat loss and over-exploitation. All populations deviated from Hardy-Weinberg equilibrium showing reduced heterozygosity. Alleles were lost from the populations by genetic drift. Genetic differentiation among populations was high (average pairwise FST = 0.405), indicating low gene flow (<1) and isolated populations due to its destructed habitat and large geographical distances (P < 0.05) among populations. Heterozygosity excess tests (except of Bu Gia Map only under infinite allele model) were negative. The high genetic variation (62.7%) was found within populations. The STRUCTURE and neighbor joining tree results suggest strong differentiation among D. costatus populations, with the three genetic clusters, Phu Quoc, Tan Phu and Bu Gia Map, and Lo Go-Xa Mat due to habitat fragmentation and isolation. The threatened status of D. costatus was related to a lack of genetic diversity, with all its populations isolated in small forest patches. We recommend the establishment of an ex situ conservation site for D. costatus with a new big population comprising all genetic groups in order to enhance its survival under different environmental stresses.
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Affiliation(s)
- N M Duc
- Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology (VAST), Cau Giay, Hanoi, Vietnam
| | - V D Duy
- Vietnam National Museum of Nature (VAST), Cau Giay, Hanoi, Vietnam
| | - B T T Xuan
- Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology (VAST), Cau Giay, Hanoi, Vietnam
| | - B V Thang
- College of Forestry Biotechnology, Vietnam Forestry University, Xuan Mai, Chuong My, Hanoi, Vietnam
| | - N T H Ha
- College of Forestry Biotechnology, Vietnam Forestry University, Xuan Mai, Chuong My, Hanoi, Vietnam
| | - N M Tam
- Vietnam National Museum of Nature (VAST), Cau Giay, Hanoi, Vietnam
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Pham HT, Cuong NT, Tam NM, Tung NT. A Systematic Investigation on CrCun Clusters with n = 9-16: Noble Gas and Tunable Magnetic Property. J Phys Chem A 2016; 120:7335-43. [PMID: 27556591 DOI: 10.1021/acs.jpca.6b04221] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A systematic investigation on structure, dissociation behavior, chemical bonding, and magnetic property of Cr-doped Cun clusters (n = 9-16) is carried out using the mean of density functional theory calculations. It is found that CrCu12 is a crucial size, preferring an icosahedral Cu12 cage with the central Cr dopant. Smaller cluster sizes appear as on the way to form the CrCu12 icosahedron while larger ones are produced by attaching additional Cu atoms to the CrCu12 core. The presence of Cr dopant obviously enhances the stability of CrCun clusters in comparison to that of pure counterparts. Exceptionally stable CrCu12 has an 18-electron closed-shell electronic structure, mimicking a noble gas in the viewpoint of superatom concept. Analysis on cluster electronic structure shows that the interplay between 3d orbitals of Cr and 4s orbitals of Cu has a vital role on the magnetic properties of CrCun clusters.
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Affiliation(s)
- Hung Tan Pham
- Institute for Computational Science and Technology , Ho Chi Minh City, Vietnam
| | - Ngo Tuan Cuong
- Center for Computational Science, Hanoi National University of Education , Hanoi, Vietnam
| | - Nguyen Minh Tam
- Computational Chemistry Research Group & Faculty of Applied Sciences, Ton Duc Thang University , Ho Chi Minh City, Vietnam
| | - Nguyen Thanh Tung
- Institute of Materials Science, Vietnam Academy of Science and Technology , Hanoi, Vietnam
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Thornblade LW, Henry EG, Minh Tam N, Markuns JF. A novel tool for assessing primary care quality at the point of care in Vietnam. Educ Prim Care 2016; 27:416-420. [PMID: 27583531 DOI: 10.1080/14739879.2016.1222505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND The development of improved primary care systems around the world has received increased attention as a step towards improved health care for all. Vietnam is engaged in efforts to improve health care quality with a focus on primary care and Family Medicine training. New methods of assessment are needed to accurately measure competency in primary care practice. METHODS A behaviourally-anchored rating scale was developed focused on core primary care principles for use in direct observation at the site of primary care delivery. This assessment tool was implemented with trainees in Family Medicine and a cohort of physicians not trained in Family Medicine. RESULTS The tool measured statistically significant differences in selected behaviours related to communication skills and comprehensiveness among Family Medicine trained physicians. No significant differences were measured in other primary care domains. CONCLUSION This behaviourally-anchored rating scale is a feasible tool for use in direct observation of primary care practice delivery in developing settings. More work is needed to refine this tool and assess its sensitivity, validity and reliability.
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Affiliation(s)
| | | | - Nguyen Minh Tam
- c Department of Family Medicine , Hue University of Medicine and Pharmacy , Hue , Vietnam
| | - Jeffrey F Markuns
- d Department of Family Medicine, Global Health Collaborative , Boston University , Boston , MA , USA
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Pham HT, Cuong NT, Tam NM, Lam VD, Tung NT. Structure, magnetism, and dissociation energy of small bimetallic cobalt-chromium oxide cluster cations: A density-functional-theory study. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2015.11.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Pham HT, Tam NM, Pham-Ho MP, Nguyen MT. Stability and bonding of the multiply coordinated bimetallic boron cycles: B8M22−, B7NM2and B6C2M2with M = Sc and Ti. RSC Adv 2016. [DOI: 10.1039/c6ra04948f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A theoretical investigation of the geometry, stability and aromaticity of boron clusters doped by two Sc and Ti atoms was carried out using DFT calculations.
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Affiliation(s)
- Hung Tan Pham
- Computational Chemistry Research Group
- Ton Duc Thang University
- Ho Chi Minh City
- Vietnam
- Faculty of Applied Sciences
| | - Nguyen Minh Tam
- Computational Chemistry Research Group
- Ton Duc Thang University
- Ho Chi Minh City
- Vietnam
- Faculty of Applied Sciences
| | - My Phuong Pham-Ho
- Institute for Computational Science and Technology (ICST)
- Ho Chi Minh City
- Vietnam
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Huong NTT, Mundy G, Neukom J, Zule W, Tuan NM, Tam NM. Social marketing of low dead space syringes in Vietnam: findings from a 1-year pilot program in Hanoi, Thai Nguyen, and Ho Chi Minh City. Harm Reduct J 2015; 12:15. [PMID: 26024921 PMCID: PMC4460649 DOI: 10.1186/s12954-015-0049-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 05/14/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Although a growing body of evidence suggests that low dead space syringes may reduce the risk of human immunodeficiency virus (HIV) and Hepatitis C virus infection associated with sharing syringes among people who inject drugs, there is little evidence of effective approaches to motivate people who inject drugs (PWID) to shift from high to low dead space syringes. METHODS Using a mix of consumer and trade marketing approaches, informed by rapid assessments of both the syringe market and PWID preferences, practices, and behaviors in Hanoi and Ho Chi Minh City, Population Services International (PSI) Vietnam piloted an intervention to increase the use of low dead space syringes (LDSS) in the three provinces of Hanoi, Ho Chi Minh City, and Thai Nguyen, where an estimated 31% of PWID are HIV positive and 58% are living with hepatitis C virus (HCV). RESULTS This paper provides a summary of the social marketing activities implemented and results achieved by PSI Vietnam during an initial 1-year pilot period from December 2012 to December 2013 in these three provinces to explore their effectiveness in motivating PWID to use low dead space syringes. We found major increases in sales of LDSS accompanied by increases in reported use and consistent use of LDSS among PWID in the three provinces included in the pilot program and a positive and independent association (odds ratio (OR) 21.08; 95% confidence interval (CI) 10.6-27.3) between LDSS use and exposure to social marketing activities. We also found that LDSS use had a stronger association with perceptions of LDSS product quality than with perceptions regarding LDSS potential to reduce HIV transmission risk and use. CONCLUSIONS We conclude that social marketing interventions have an important role to play in widening access to and the use of LDSS for PWID, as they address the need for PWID to find LDSS when and where they need them and also promote the benefits of LDSS use to PWID. High coverage of these activities among PWID appears to be the key in achieving these successes.
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Affiliation(s)
| | - Gary Mundy
- Population Services International, Washington, USA.
| | | | - William Zule
- Research Triangle Institute International, Durham, USA.
| | | | - Nguyen Minh Tam
- Vietnam Administration for HIV/AIDS Control/Ministry of Health, Hanoi, Vietnam.
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Tam NM, Hang TD, Pham HT, Nguyen HT, Pham-Ho MP, Denis PA, Nguyen MT. Bonding and singlet-triplet gap of silicon trimer: Effects of protonation and attachment of alkali metal cations. J Comput Chem 2015; 36:805-15. [DOI: 10.1002/jcc.23856] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 11/30/2014] [Accepted: 12/15/2014] [Indexed: 11/06/2022]
Affiliation(s)
- Nguyen Minh Tam
- Institute for Computational Science and Technology (ICST), Quang Trung Software City; Ho Chi Minh City Vietnam
- Department of Chemistry; University of Leuven; B-3001 Leuven Belgium
| | - Tran Dieu Hang
- Department of Chemistry; University of Leuven; B-3001 Leuven Belgium
| | - Hung Tan Pham
- Institute for Computational Science and Technology (ICST), Quang Trung Software City; Ho Chi Minh City Vietnam
| | - Huyen Thi Nguyen
- Department of Chemistry; University of Leuven; B-3001 Leuven Belgium
| | - My Phuong Pham-Ho
- Institute for Computational Science and Technology (ICST), Quang Trung Software City; Ho Chi Minh City Vietnam
| | - Pablo A. Denis
- Computational Nanotechnology, DETEMA Facultad de Quımica; Gral, UDELAR, Flores 2124, CC 1157, 11800 Montevideo Uruguay
| | - Minh Tho Nguyen
- Department of Chemistry; University of Leuven; B-3001 Leuven Belgium
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Abstract
The smallest triple ring tubular silicon cluster Mn2@Si15 is reported for the first time.
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Affiliation(s)
- Hung Tan Pham
- Institute for Computational Science and Technology (ICST)
- Ho Chi Minh City
- Vietnam
| | - Thu-Thuy Phan
- Institute for Computational Science and Technology (ICST)
- Ho Chi Minh City
- Vietnam
| | - Nguyen Minh Tam
- Institute for Computational Science and Technology (ICST)
- Ho Chi Minh City
- Vietnam
- Department of Chemistry
- KU Leuven
| | - Long Van Duong
- Institute for Computational Science and Technology (ICST)
- Ho Chi Minh City
- Vietnam
| | - My Phuong Pham-Ho
- Institute for Computational Science and Technology (ICST)
- Ho Chi Minh City
- Vietnam
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Tam NM, Pham HT, Duong LV, Pham-Ho MP, Nguyen MT. Fullerene-like boron clusters stabilized by an endohedrally doped iron atom: BnFe with n = 14, 16, 18 and 20. Phys Chem Chem Phys 2015; 17:3000-3. [DOI: 10.1039/c4cp04279d] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Stabilized fullerene and tubular forms can be produced in boron clusters Bnin small sizes fromn∼ 14 to 20 upon doping by transition metal atoms.
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Affiliation(s)
- Nguyen Minh Tam
- Institute for Computational Science and Technology (ICST)
- Ho Chi Minh City
- Vietnam
- Department of Chemistry
- University of Leuven
| | - Hung Tan Pham
- Institute for Computational Science and Technology (ICST)
- Ho Chi Minh City
- Vietnam
| | - Long Van Duong
- Institute for Computational Science and Technology (ICST)
- Ho Chi Minh City
- Vietnam
| | - My Phuong Pham-Ho
- Institute for Computational Science and Technology (ICST)
- Ho Chi Minh City
- Vietnam
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