Natural Sciences and Technology : [1086]

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Collection's Items (Sorted by Submit Date in Descending order): 1 to 20 of 1086
  • document.pdf.jpg
  • Article


  • Authors: Nguyen, Van Dung (2019)

  • Vegetable oil-based insulating oils have been successfully applied in the field of insulation for distribution transformers because vegetable oils are fully biodegradable, high dielectric strength, high flash point and better compatible with paper insulators than mineral-based insulating oil. However, vegetable oils still have drawbacks such as high viscosity, high pour point, low oxidation stability and low resistance to the formation of fast mode streamers. Therefore, many studies have been performed to improve properties of vegetable oils. This paper will summarize the important research results on physicochemical properties of vegetable oils as well as the methods used to improve ...

  • document(13).pdf.jpg
  • Article


  • Authors: Pham, Hong Cong; Nguyen, Dinh Duc (2019)

  • This paper presents an analytical approach to postbuckling behaviors of functionally graded multilayer nanocomposite plates reinforced by a low content of graphene platelets (GPLs) using the first order shear deformation theory, stress function and von Karman-type nonlinear kinematics and include the effect of an initial geometric imperfection. The weight fraction of GPL nano fillers is assumed to be constant in each individual GPL-reinforced composite (GPLRC). The modified Halpin-Tsai micromechanics model that takes into account the GPL geometry effect is adopted to estimate the effective Young’s modulus of GPLRC layers. The plate is assumed to resting on Pasternak foundation model a...

  • document(12).pdf.jpg
  • Article


  • Authors: Nguyen, Thi Dung; Hoang, Van Thanh; Nguyen, Dinh Lam (2019)

  • NaYF4:(Yb,Tm) upconversion materials were synthesized by the simple hydrothermal method. Growth duration was varied from 4h to 12h under a growth temperature of 150oC. The structural, optical and surface morphology characteristics of the NaYF4:(Yb,Tm) UC materials were investigated. The XRD and SEM results illustrated that the NaYF4:(Yb,Tm) materials were transformed from the multiple phases (hexagonal and cubic) to the single-phase (hexagonal prism) as growth duration being longer than 8h with the average diameter and length of these prisms being about 0.5 µm and 2 µm, respectively. Under 980 nm laser excitation, the NaYF4:(Yb,Tm) emits at peaks of 450 nm (1D2→ 3F4), 475 nm (1G4→3H6...

  • document(11).pdf.jpg
  • Article


  • Authors: Duong, Hong Anh; Vu, Minh Tuan; Van, Thi Thanh Huyen; Nguyen, Manh Huy; Nguyen, Thanh Dam (2019)

  • The optimized capillary electrophoresis (CE) was applied to separate and detect the 10-hydroxy-2-decenoic acid (10-HAD) in royal jelly products. The method only requires that the sample solution need to be centrifuged and filtered before analyzed by the home-made capillary electrophoresis system. Firstly, 10-HDA was separated in a fused silica column with a diameter of 50 um using 20 mM Tris/Acetic buffer (pH 8.5) as a background electrolyte and a separation voltage of -17kV. Then, 10-HDA was detected by capacitively coupled contactless conductivity detection (C4D) with the migration time less than 8 minutes. Nine commercial products of royal jelly with Vietnamese and imported origin ...

  • document(10).pdf.jpg
  • Article


  • Authors: Le, Huy Hoang; Pham, Thi Phuong; Nguyen, Thi Hanh; Ho, Ba Do; Nguyen, Quang Huy (2019)

  • In this study, acidic hydrolysis to release the aglycone quercetin from plant extracts under ultrasound-assisted conditions was investigated. Based on the stability of quercetin, the suitable conditions were as follows: methanol/H2O (50:20, v/v) was added to the powder plants (ratio 50:1, ml/g), these mixtures were placed in ultrasonic bath of 37 kHz/550W; kept at 70°C within 30 min and then filtered. The filtrate was acidified with HCl (70:8, ml/ml). Lastly, the ultrasonication was carried out for hydrolysis for 1 hour (the second ultrasound) to obtain quercetin. We have obtained quercetin containing hydrolyzed extract from 10 plants to determine quercetin concentrations (using the H...

  • document(9).pdf.jpg
  • Article


  • Authors: Nguyen, Huu Duc Ton; Nguyen, Thi Thuy Hien; Tran, Chi Canh; Dang, Hoa Thao; Nguyen, Thi Nha Y; Dinh, Minh Quang (2019)

  • This study was conducted in the coastal estuaries in Bac Lieu and Ca Mau provinces in order to provide data on morphological and histological characteristics of as well as the spermatocyte development at every stage of the development of testis of goby Glossogobius sparsipapillus. The analysis results of 226 fish individuals, collected monthly from April 2019 to September 2019 by using the bottom nets, showed that the testis of this fish was double strands. In stage I, testis was small, thin and transparent; and the weight and size of testis increased from that stage onward. The colour of the testis became ivory white with the smooth and puffed surface. Spermatogonia were found throug...

  • document(8).pdf.jpg
  • Article


  • Authors: Nguyen, Huu Tho; Trang, Thanh Tu (2019)

  • Geometries associated relative stabilities, averaged binding energy, fragmentation energy, second-order energy difference and energy gaps of V-doped germanium cationic clusters GenV+ (n = 9-13) have been investigated by using density functional theory with the BP86 exchange-correlation potential and effective core potential (ECP) LanL2DZ basis sets. Natural population analysis charge is also examined to understand the associated charge transfer in structures of clusters. When an electron is removed from neutral cluster GenV to form the cation cluster GenV+, geometric structure of the lowest energy isomers change. The endohedral cage structure of the cation clusters appears at n = 10 i...

  • document(7).pdf.jpg
  • Article


  • Authors: Hoang, Quoc Anh; Takahashi, Shin; Duong, Thi Thao; Nguyen, Hung Thai; Pham, Thanh Khiet; Nguyen, Thi Quynh Hoa; Le, Thi Phuong Quynh; Le, Nhu Da; Tu, Binh Minh; Tran, Manh Tri (2019)

  • Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in settled house dust and road dust samples collected from a core urban area of Hanoi. Levels of PAHs ranged from 830 to 3500 (median 2000) ng/g in house dust, and from 1400 to 4700 (median 1700) ng/g in road dust. Concentrations of PAHs in dust samples of this study were within the moderate range as compared with those from other countries in the world. Toxic equivalents to benzo[a]pyrene (BaP-EQs) in our samples ranged from 81 to 850 (median 330) ng BaP-EQ/g with principal contributors as BaP and dibenz[a,h]anthracene, which accounted for 69% to 93% of BaP-EQs. In almost all the samples, proportions of high...

  • document(6).pdf.jpg
  • Article


  • Authors: Nguyen, Van Ha; Doan, Thanh Dat; Trieu, Thi Nguyet (2019)

  • A theoretical study on stereo and electronic properties of a series of six 1,2,4-triazole-derived carbenes bearing different N4-substituents, namely isopropyl (1), benzyl (2), phenyl (3), mesityl (4), 2,6-diisopropylphenyl (5) and 1-naphthyl (6), has been carried out. Structures of the six carbenes were first optimized using Gaussian® 16 at B3LYP level. Their molecular geometries and electronic structures of the frontier orbitals were examined. The results suggest the similarity in nature of their HOMOs, which all posses s symmetry with respect to the heterocycle and essentially be the lone electron pair on the Ccarbene. Steric properties of the NHCs was also quantified using percent ...

  • document(5).pdf.jpg
  • Article


  • Authors: Bui, Van Bac (2019)

  • I examined variation in community structure, species richness, biomass and abundance of Coprini dung beetles from 45 trapping sites in meadows, 35-year-old secondary forests and primary forests in tropical, high-elevation karst ecosystems of Puluong Nature Reserve, Thanh Hoa Province. My main aim was to explore community response to the influence of land use change. By comparing the structure and community attributes of the beetles between 35-year-old secondary forests and primary forests, I expected to give indications on the conservation value of the old secondary forests for beetle conservation. Community structure significantly differed among land-use types. Species richness, abun...

  • document(4).pdf.jpg
  • Article


  • Authors: Nguyen, Minh Hai; Tran, Thi Tam Thu; Dinh, Thi Thao (2019)

  • A series of ligands containing pyrenyl core which are PyEt1, PyEt2, and PyEt3 have been successfully synthesized. PyEt2, a bidentate ligand and PyEt3, a tridentate ligand were used to prepared Pd(II) complexes by reactions with PdCl2(CH3CN)2. The titled compounds displayed intriguing geometries around the central palladium atoms. 1H-NMR results showed that palladium in Pd-PyEt3 adopts a five-coordinate configuration

  • document(3).pdf.jpg
  • Article


  • Authors: Luu, Thi Binh; Le, Thi Thanh Huong; Nguyen, Trung Thanh; Nguyen, Phu Hung (2019)

  • Cellular senescence is a state in wich cells can not longer divide. The dysregulation of the cell senescence signaling pathway could lead to uncontrolled cell proliferation and formation of malignant cells. Intervening in cell senessence signaling pathway to bring cancer cells back to cell senessence state is a potential way in cancertreatment. Recent studies show that tumor cells can undergo celluar senessencestate by using special chemotherapy. In this study, we indicatedthat All trans retinoic acid (ATRA) is able to influence the expression of genes involved in cell senessence signaling pathway in gastric cancer cells MKN45. ATRA down-regulatesthe expression of important genes cont...

  • document(2).pdf.jpg
  • Article


  • Authors: Pham, Thu Thuy; Pham, Chien Thang; Nguyen, Viet Ha; Trieu, Thi Nguyet (2019)

  • The curcumin derivative 4’,4’’-dibenzoylcurcumin (HL) was synthesized by the reaction between curcumin and benzoyl chloride in the presence of pyridine as a supporting base. The composition and structure of HL were characterized by spectroscopic methods such as IR, 1H and 13C NMR spectroscopy. Reactions of HL and transition metal ions, such as Fe3+ and Cu2+, in mixtures of CH3OH and CH2Cl2 gave rise to the corresponding complexes, compositions and structural features of which were studied by thermal analysis and IR spectroscopy. The results strongly suggested the obtained complexes with the compositions of [FeL3] and [CuL2]. In such compounds, metal ions coordinates with the deprotona...

  • document(1).pdf.jpg
  • Article


  • Authors: Nguyen, Danh Hung; Nguyen, Thanh Chung; Ly, Ngoc Sam; Le, Thi Huong (2019)

  • Amomum glabrum S. Q. Tong (Zingiberaceae), collected from the Provinces in North Central Vietnam (Thanh Hoa province: Xuan Lien Nature Reserve; Nghe An: Pu Mat National Park, Pu Huong and Pu Hoat Nature Resever; Ha Tinh: Vu Quang National Park; Quang Binh: Phong Nha-Ke Bang National Park; Thừa Thiên Huế: Bạch Mã National Park), is reported here as a new record for the flora of Vietnam, which raised the species number of Amomum to 13. A detailed description and coloured photographs are provided along with data on distribution, ecology, phenology, conservation status and notes on the relative species

  • Seasonal Variability in The Genus-Family Structure of Free-Living Nematode Communities in Organic Shrimp Farming Ponds, Ca Mau Province.pdf.jpg
  • Article


  • Authors: Tran, Thanh Thai; Ngo, Xuan Quang (2019)

  • This study determined the seasonal variability of free-living nematode communities structure (genus/family level) in organic shrimp farms ponds in Tam Giang commune, Nam Can district, Ca Mau province. Based on the result of SIMPER analysis, the average similarity in nematode communities at genus level was low with 30.75% and 30.81% (in dry and rainy season, respectively). However, the average dissimilarity between seasons was considerably high with 71.75%. Terschellingia, Daptonema, and Parodontophora were main genera contributing to similarity/dissimilarity between seasons. At the family level, results of SIMPER analysis showed that the average similarity was low with 37.12% and 39.0...

  • Research Synthesis of La3+ Doped TiO2 Nanoparticles by Hydrothermal Method, Study on Photocatalytic Activity of Decomposition of Methylene Blue under Ultraviolet Irradiation.pdf.jpg
  • Article


  • Authors: Đặng, Thị Minh Huệ; Nguyễn, Thị Tuyết Mai; Trần, Văn Châu; Trần, Thị Thu Huyền; Nguyễn, Thị Lan; Tạ, Ngọc Dũng; Huỳnh, Đăng Chính (2019)

  • Trong nghiên cứu này, với mục đích nâng cao hiệu quả xúc tác quang của TiO2, chúng tôi đã nghiên cứu tổng hợp vật liệu TiO2 pha tạp La3+ với các tỷ lệ pha tạp 1%, 2,5%, 5% (mol/mol so với Ti4+) bằng phương pháp thủy nhiệt. Nhiệt độ thủy nhiệt được khảo sát ở 180 oC trong 12 giờ. Các đặc trưng vật liệu đã được khảo sát bằng các phương pháp đo XRD, SEM, UV-Vis rắn. Kết quả cho thấy, các vật liệu tổng hợp được đều có kích thước hạt tinh thể nhỏ, mịn cỡ nano-mét (4,56,5 nm). Các mẫu TiO2 pha tạp bởi La3+ đã có sự chuyển dịch về phía bước sóng dài hơn ( 400500 nm) so với mẫu TiO2 không pha tạp ( 380 nm). Năng lượng vùng cấm quang Eg của các mẫu TiO2 pha tạp được giảm xuống tới 3,043...

  • Microarray Data Analysis of as-induced Rice Roots by using Easygo and Mapman Softwares.pdf.jpg
  • Article


  • Authors: Nguyễn, Thị Thúy Quỳnh; Phạm, Lê Ngọc Hân; Võ, Khánh Tâm; Phùng, Thị Kim Huệ; Huang, Tsai-Lien (2019)

  • Cây lúa là một trong những loại lương thực quan trọng của các nước trong khu vực Châu Á như Trung Quốc, Việt nam… Nhiều nghiên cứu gần đây cho thấy hàm lượng Asen (As) có trong gạo vượt ngưỡng quy định và điều này gây ảnh hưởng tới sức khỏe của con người. Việc nghiên cứu cơ chế phân tử và tìm ra những gen chống chịu As của cây lúa là điều vô cùng quan trọng và cấp thiết. Trong nghiên cứu này, chúng tôi tiến hành phân tích những thay đổi hệ phiên mã của tế bào rễ cây lúa sau 24 giờ xử lý với As bằng kỹ thuật microarray. Kết quả cho thấy một số lượng lớn các gen thay đổi mức độ biểu hiện (720 gen). Phần mềm EasyGO và Mapman là những công cụ đắc lực trong trong việc phân tích số liệu mic...

  • Expression of CYP2E1 gene in paint workers occupationally exposed to organic solvents.pdf.jpg
  • Article


  • Authors: Nguyễn, Thị Hiền; Đỗ, Thị Cẩm Nhung; Nguyễn, Phú Hùng; Bùi, Phương Thuận; Nguyễn, Quang Huy (2019)

  • Người lao động trong ngành sơn dễ bị phơi nhiễm với dung môi hữu cơ, đặc biệt là nhóm chất benzen, toluen, ethylbenzen và xylen (BTEX). CYP2E1 là gen mã hóa enzym CYP2E1 đóng vai trò quan trọng trong quá trình chuyển hóa nhóm chất BTEX giúp cơ thể thải độc. Mức độ biểu hiện của gen CYP2E1 là một chỉ thị sinh học có độ nhạy, chính xác cao và được một số tác giả đề xuất làm chỉ số giám sát sinh học cho người lao động có tiếp xúc nghề nghiệp với nhóm chất BTEX. Trong bài báo này, chúng tôi phân tích mức độ biểu hiện của gen CYP2E1 ở 118 người, trong đó 73 người làm việc tại công ty sản xuất sơn có tiếp xúc với BTEX và 45 người không tiếp xúc với BTEX thông qua phương pháp Real time – PCR...

  • Effect of Technological Factors on some Properties of Composite tube with Epoxy Resin K-153 Matrix.pdf.jpg
  • Article


  • Authors: Đặng, Thị Minh Huệ; Nguyễn, Thị Tuyết Mai; Trần, Văn Châu; Trần, Thị Thu Huyền; Nguyễn, Thị Lan; Tạ, Ngọc Dũng; Huỳnh, Đăng Chính (2019)

  • Trong nghiên cứu này, với mục đích nâng cao hiệu quả xúc tác quang của TiO2, chúng tôi đã nghiên cứu tổng hợp vật liệu TiO2 pha tạp La3+ với các tỷ lệ pha tạp 1%, 2,5%, 5% (mol/mol so với Ti4+) bằng phương pháp thủy nhiệt. Nhiệt độ thủy nhiệt được khảo sát ở 180 oC trong 12 giờ. Các đặc trưng vật liệu đã được khảo sát bằng các phương pháp đo XRD, SEM, UV-Vis rắn. Kết quả cho thấy, các vật liệu tổng hợp được đều có kích thước hạt tinh thể nhỏ, mịn cỡ nano-mét (4,56,5 nm). Các mẫu TiO2 pha tạp bởi La3+ đã có sự chuyển dịch về phía bước sóng dài hơn ( 400500 nm) so với mẫu TiO2 không pha tạp ( 380 nm). Năng lượng vùng cấm quang Eg của các mẫu TiO2 pha tạp được giảm xuống tới 3,043...

  • Expression of CYP2E1 gene in paint workers occupationally exposed to organic solvents.pdf.jpg
  • Article


  • Authors: Nguyễn, Thị Hiền; Đỗ, Thị Cẩm Nhung; Nguyễn, Phú Hùng; Bùi, Phương Thuận; Nguyễn, Quang Huy (2019)

  • Người lao động trong ngành sơn dễ bị phơi nhiễm với dung môi hữu cơ, đặc biệt là nhóm chất benzen, toluen, ethylbenzen và xylen (BTEX). CYP2E1 là gen mã hóa enzym CYP2E1 đóng vai trò quan trọng trong quá trình chuyển hóa nhóm chất BTEX giúp cơ thể thải độc. Mức độ biểu hiện của gen CYP2E1 là một chỉ thị sinh học có độ nhạy, chính xác cao và được một số tác giả đề xuất làm chỉ số giám sát sinh học cho người lao động có tiếp xúc nghề nghiệp với nhóm chất BTEX. Trong bài báo này, chúng tôi phân tích mức độ biểu hiện của gen CYP2E1 ở 118 người, trong đó 73 người làm việc tại công ty sản xuất sơn có tiếp xúc với BTEX và 45 người không tiếp xúc với BTEX thông qua phương pháp Real tim...

Collection's Items (Sorted by Submit Date in Descending order): 1 to 20 of 1086

Natural Sciences and Technology : [1086]

Follow this collection to receive daily e-mail notification of new additions
Collection's Items (Sorted by Submit Date in Descending order): 1 to 20 of 1086
  • document.pdf.jpg
  • Article


  • Authors: Nguyen, Van Dung (2019)

  • Vegetable oil-based insulating oils have been successfully applied in the field of insulation for distribution transformers because vegetable oils are fully biodegradable, high dielectric strength, high flash point and better compatible with paper insulators than mineral-based insulating oil. However, vegetable oils still have drawbacks such as high viscosity, high pour point, low oxidation stability and low resistance to the formation of fast mode streamers. Therefore, many studies have been performed to improve properties of vegetable oils. This paper will summarize the important research results on physicochemical properties of vegetable oils as well as the methods used to improve ...

  • document(13).pdf.jpg
  • Article


  • Authors: Pham, Hong Cong; Nguyen, Dinh Duc (2019)

  • This paper presents an analytical approach to postbuckling behaviors of functionally graded multilayer nanocomposite plates reinforced by a low content of graphene platelets (GPLs) using the first order shear deformation theory, stress function and von Karman-type nonlinear kinematics and include the effect of an initial geometric imperfection. The weight fraction of GPL nano fillers is assumed to be constant in each individual GPL-reinforced composite (GPLRC). The modified Halpin-Tsai micromechanics model that takes into account the GPL geometry effect is adopted to estimate the effective Young’s modulus of GPLRC layers. The plate is assumed to resting on Pasternak foundation model a...

  • document(12).pdf.jpg
  • Article


  • Authors: Nguyen, Thi Dung; Hoang, Van Thanh; Nguyen, Dinh Lam (2019)

  • NaYF4:(Yb,Tm) upconversion materials were synthesized by the simple hydrothermal method. Growth duration was varied from 4h to 12h under a growth temperature of 150oC. The structural, optical and surface morphology characteristics of the NaYF4:(Yb,Tm) UC materials were investigated. The XRD and SEM results illustrated that the NaYF4:(Yb,Tm) materials were transformed from the multiple phases (hexagonal and cubic) to the single-phase (hexagonal prism) as growth duration being longer than 8h with the average diameter and length of these prisms being about 0.5 µm and 2 µm, respectively. Under 980 nm laser excitation, the NaYF4:(Yb,Tm) emits at peaks of 450 nm (1D2→ 3F4), 475 nm (1G4→3H6...

  • document(11).pdf.jpg
  • Article


  • Authors: Duong, Hong Anh; Vu, Minh Tuan; Van, Thi Thanh Huyen; Nguyen, Manh Huy; Nguyen, Thanh Dam (2019)

  • The optimized capillary electrophoresis (CE) was applied to separate and detect the 10-hydroxy-2-decenoic acid (10-HAD) in royal jelly products. The method only requires that the sample solution need to be centrifuged and filtered before analyzed by the home-made capillary electrophoresis system. Firstly, 10-HDA was separated in a fused silica column with a diameter of 50 um using 20 mM Tris/Acetic buffer (pH 8.5) as a background electrolyte and a separation voltage of -17kV. Then, 10-HDA was detected by capacitively coupled contactless conductivity detection (C4D) with the migration time less than 8 minutes. Nine commercial products of royal jelly with Vietnamese and imported origin ...

  • document(10).pdf.jpg
  • Article


  • Authors: Le, Huy Hoang; Pham, Thi Phuong; Nguyen, Thi Hanh; Ho, Ba Do; Nguyen, Quang Huy (2019)

  • In this study, acidic hydrolysis to release the aglycone quercetin from plant extracts under ultrasound-assisted conditions was investigated. Based on the stability of quercetin, the suitable conditions were as follows: methanol/H2O (50:20, v/v) was added to the powder plants (ratio 50:1, ml/g), these mixtures were placed in ultrasonic bath of 37 kHz/550W; kept at 70°C within 30 min and then filtered. The filtrate was acidified with HCl (70:8, ml/ml). Lastly, the ultrasonication was carried out for hydrolysis for 1 hour (the second ultrasound) to obtain quercetin. We have obtained quercetin containing hydrolyzed extract from 10 plants to determine quercetin concentrations (using the H...

  • document(9).pdf.jpg
  • Article


  • Authors: Nguyen, Huu Duc Ton; Nguyen, Thi Thuy Hien; Tran, Chi Canh; Dang, Hoa Thao; Nguyen, Thi Nha Y; Dinh, Minh Quang (2019)

  • This study was conducted in the coastal estuaries in Bac Lieu and Ca Mau provinces in order to provide data on morphological and histological characteristics of as well as the spermatocyte development at every stage of the development of testis of goby Glossogobius sparsipapillus. The analysis results of 226 fish individuals, collected monthly from April 2019 to September 2019 by using the bottom nets, showed that the testis of this fish was double strands. In stage I, testis was small, thin and transparent; and the weight and size of testis increased from that stage onward. The colour of the testis became ivory white with the smooth and puffed surface. Spermatogonia were found throug...

  • document(8).pdf.jpg
  • Article


  • Authors: Nguyen, Huu Tho; Trang, Thanh Tu (2019)

  • Geometries associated relative stabilities, averaged binding energy, fragmentation energy, second-order energy difference and energy gaps of V-doped germanium cationic clusters GenV+ (n = 9-13) have been investigated by using density functional theory with the BP86 exchange-correlation potential and effective core potential (ECP) LanL2DZ basis sets. Natural population analysis charge is also examined to understand the associated charge transfer in structures of clusters. When an electron is removed from neutral cluster GenV to form the cation cluster GenV+, geometric structure of the lowest energy isomers change. The endohedral cage structure of the cation clusters appears at n = 10 i...

  • document(7).pdf.jpg
  • Article


  • Authors: Hoang, Quoc Anh; Takahashi, Shin; Duong, Thi Thao; Nguyen, Hung Thai; Pham, Thanh Khiet; Nguyen, Thi Quynh Hoa; Le, Thi Phuong Quynh; Le, Nhu Da; Tu, Binh Minh; Tran, Manh Tri (2019)

  • Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in settled house dust and road dust samples collected from a core urban area of Hanoi. Levels of PAHs ranged from 830 to 3500 (median 2000) ng/g in house dust, and from 1400 to 4700 (median 1700) ng/g in road dust. Concentrations of PAHs in dust samples of this study were within the moderate range as compared with those from other countries in the world. Toxic equivalents to benzo[a]pyrene (BaP-EQs) in our samples ranged from 81 to 850 (median 330) ng BaP-EQ/g with principal contributors as BaP and dibenz[a,h]anthracene, which accounted for 69% to 93% of BaP-EQs. In almost all the samples, proportions of high...

  • document(6).pdf.jpg
  • Article


  • Authors: Nguyen, Van Ha; Doan, Thanh Dat; Trieu, Thi Nguyet (2019)

  • A theoretical study on stereo and electronic properties of a series of six 1,2,4-triazole-derived carbenes bearing different N4-substituents, namely isopropyl (1), benzyl (2), phenyl (3), mesityl (4), 2,6-diisopropylphenyl (5) and 1-naphthyl (6), has been carried out. Structures of the six carbenes were first optimized using Gaussian® 16 at B3LYP level. Their molecular geometries and electronic structures of the frontier orbitals were examined. The results suggest the similarity in nature of their HOMOs, which all posses s symmetry with respect to the heterocycle and essentially be the lone electron pair on the Ccarbene. Steric properties of the NHCs was also quantified using percent ...

  • document(5).pdf.jpg
  • Article


  • Authors: Bui, Van Bac (2019)

  • I examined variation in community structure, species richness, biomass and abundance of Coprini dung beetles from 45 trapping sites in meadows, 35-year-old secondary forests and primary forests in tropical, high-elevation karst ecosystems of Puluong Nature Reserve, Thanh Hoa Province. My main aim was to explore community response to the influence of land use change. By comparing the structure and community attributes of the beetles between 35-year-old secondary forests and primary forests, I expected to give indications on the conservation value of the old secondary forests for beetle conservation. Community structure significantly differed among land-use types. Species richness, abun...

  • document(4).pdf.jpg
  • Article


  • Authors: Nguyen, Minh Hai; Tran, Thi Tam Thu; Dinh, Thi Thao (2019)

  • A series of ligands containing pyrenyl core which are PyEt1, PyEt2, and PyEt3 have been successfully synthesized. PyEt2, a bidentate ligand and PyEt3, a tridentate ligand were used to prepared Pd(II) complexes by reactions with PdCl2(CH3CN)2. The titled compounds displayed intriguing geometries around the central palladium atoms. 1H-NMR results showed that palladium in Pd-PyEt3 adopts a five-coordinate configuration

  • document(3).pdf.jpg
  • Article


  • Authors: Luu, Thi Binh; Le, Thi Thanh Huong; Nguyen, Trung Thanh; Nguyen, Phu Hung (2019)

  • Cellular senescence is a state in wich cells can not longer divide. The dysregulation of the cell senescence signaling pathway could lead to uncontrolled cell proliferation and formation of malignant cells. Intervening in cell senessence signaling pathway to bring cancer cells back to cell senessence state is a potential way in cancertreatment. Recent studies show that tumor cells can undergo celluar senessencestate by using special chemotherapy. In this study, we indicatedthat All trans retinoic acid (ATRA) is able to influence the expression of genes involved in cell senessence signaling pathway in gastric cancer cells MKN45. ATRA down-regulatesthe expression of important genes cont...

  • document(2).pdf.jpg
  • Article


  • Authors: Pham, Thu Thuy; Pham, Chien Thang; Nguyen, Viet Ha; Trieu, Thi Nguyet (2019)

  • The curcumin derivative 4’,4’’-dibenzoylcurcumin (HL) was synthesized by the reaction between curcumin and benzoyl chloride in the presence of pyridine as a supporting base. The composition and structure of HL were characterized by spectroscopic methods such as IR, 1H and 13C NMR spectroscopy. Reactions of HL and transition metal ions, such as Fe3+ and Cu2+, in mixtures of CH3OH and CH2Cl2 gave rise to the corresponding complexes, compositions and structural features of which were studied by thermal analysis and IR spectroscopy. The results strongly suggested the obtained complexes with the compositions of [FeL3] and [CuL2]. In such compounds, metal ions coordinates with the deprotona...

  • document(1).pdf.jpg
  • Article


  • Authors: Nguyen, Danh Hung; Nguyen, Thanh Chung; Ly, Ngoc Sam; Le, Thi Huong (2019)

  • Amomum glabrum S. Q. Tong (Zingiberaceae), collected from the Provinces in North Central Vietnam (Thanh Hoa province: Xuan Lien Nature Reserve; Nghe An: Pu Mat National Park, Pu Huong and Pu Hoat Nature Resever; Ha Tinh: Vu Quang National Park; Quang Binh: Phong Nha-Ke Bang National Park; Thừa Thiên Huế: Bạch Mã National Park), is reported here as a new record for the flora of Vietnam, which raised the species number of Amomum to 13. A detailed description and coloured photographs are provided along with data on distribution, ecology, phenology, conservation status and notes on the relative species

  • Seasonal Variability in The Genus-Family Structure of Free-Living Nematode Communities in Organic Shrimp Farming Ponds, Ca Mau Province.pdf.jpg
  • Article


  • Authors: Tran, Thanh Thai; Ngo, Xuan Quang (2019)

  • This study determined the seasonal variability of free-living nematode communities structure (genus/family level) in organic shrimp farms ponds in Tam Giang commune, Nam Can district, Ca Mau province. Based on the result of SIMPER analysis, the average similarity in nematode communities at genus level was low with 30.75% and 30.81% (in dry and rainy season, respectively). However, the average dissimilarity between seasons was considerably high with 71.75%. Terschellingia, Daptonema, and Parodontophora were main genera contributing to similarity/dissimilarity between seasons. At the family level, results of SIMPER analysis showed that the average similarity was low with 37.12% and 39.0...

  • Research Synthesis of La3+ Doped TiO2 Nanoparticles by Hydrothermal Method, Study on Photocatalytic Activity of Decomposition of Methylene Blue under Ultraviolet Irradiation.pdf.jpg
  • Article


  • Authors: Đặng, Thị Minh Huệ; Nguyễn, Thị Tuyết Mai; Trần, Văn Châu; Trần, Thị Thu Huyền; Nguyễn, Thị Lan; Tạ, Ngọc Dũng; Huỳnh, Đăng Chính (2019)

  • Trong nghiên cứu này, với mục đích nâng cao hiệu quả xúc tác quang của TiO2, chúng tôi đã nghiên cứu tổng hợp vật liệu TiO2 pha tạp La3+ với các tỷ lệ pha tạp 1%, 2,5%, 5% (mol/mol so với Ti4+) bằng phương pháp thủy nhiệt. Nhiệt độ thủy nhiệt được khảo sát ở 180 oC trong 12 giờ. Các đặc trưng vật liệu đã được khảo sát bằng các phương pháp đo XRD, SEM, UV-Vis rắn. Kết quả cho thấy, các vật liệu tổng hợp được đều có kích thước hạt tinh thể nhỏ, mịn cỡ nano-mét (4,56,5 nm). Các mẫu TiO2 pha tạp bởi La3+ đã có sự chuyển dịch về phía bước sóng dài hơn ( 400500 nm) so với mẫu TiO2 không pha tạp ( 380 nm). Năng lượng vùng cấm quang Eg của các mẫu TiO2 pha tạp được giảm xuống tới 3,043...

  • Microarray Data Analysis of as-induced Rice Roots by using Easygo and Mapman Softwares.pdf.jpg
  • Article


  • Authors: Nguyễn, Thị Thúy Quỳnh; Phạm, Lê Ngọc Hân; Võ, Khánh Tâm; Phùng, Thị Kim Huệ; Huang, Tsai-Lien (2019)

  • Cây lúa là một trong những loại lương thực quan trọng của các nước trong khu vực Châu Á như Trung Quốc, Việt nam… Nhiều nghiên cứu gần đây cho thấy hàm lượng Asen (As) có trong gạo vượt ngưỡng quy định và điều này gây ảnh hưởng tới sức khỏe của con người. Việc nghiên cứu cơ chế phân tử và tìm ra những gen chống chịu As của cây lúa là điều vô cùng quan trọng và cấp thiết. Trong nghiên cứu này, chúng tôi tiến hành phân tích những thay đổi hệ phiên mã của tế bào rễ cây lúa sau 24 giờ xử lý với As bằng kỹ thuật microarray. Kết quả cho thấy một số lượng lớn các gen thay đổi mức độ biểu hiện (720 gen). Phần mềm EasyGO và Mapman là những công cụ đắc lực trong trong việc phân tích số liệu mic...

  • Expression of CYP2E1 gene in paint workers occupationally exposed to organic solvents.pdf.jpg
  • Article


  • Authors: Nguyễn, Thị Hiền; Đỗ, Thị Cẩm Nhung; Nguyễn, Phú Hùng; Bùi, Phương Thuận; Nguyễn, Quang Huy (2019)

  • Người lao động trong ngành sơn dễ bị phơi nhiễm với dung môi hữu cơ, đặc biệt là nhóm chất benzen, toluen, ethylbenzen và xylen (BTEX). CYP2E1 là gen mã hóa enzym CYP2E1 đóng vai trò quan trọng trong quá trình chuyển hóa nhóm chất BTEX giúp cơ thể thải độc. Mức độ biểu hiện của gen CYP2E1 là một chỉ thị sinh học có độ nhạy, chính xác cao và được một số tác giả đề xuất làm chỉ số giám sát sinh học cho người lao động có tiếp xúc nghề nghiệp với nhóm chất BTEX. Trong bài báo này, chúng tôi phân tích mức độ biểu hiện của gen CYP2E1 ở 118 người, trong đó 73 người làm việc tại công ty sản xuất sơn có tiếp xúc với BTEX và 45 người không tiếp xúc với BTEX thông qua phương pháp Real time – PCR...

  • Effect of Technological Factors on some Properties of Composite tube with Epoxy Resin K-153 Matrix.pdf.jpg
  • Article


  • Authors: Đặng, Thị Minh Huệ; Nguyễn, Thị Tuyết Mai; Trần, Văn Châu; Trần, Thị Thu Huyền; Nguyễn, Thị Lan; Tạ, Ngọc Dũng; Huỳnh, Đăng Chính (2019)

  • Trong nghiên cứu này, với mục đích nâng cao hiệu quả xúc tác quang của TiO2, chúng tôi đã nghiên cứu tổng hợp vật liệu TiO2 pha tạp La3+ với các tỷ lệ pha tạp 1%, 2,5%, 5% (mol/mol so với Ti4+) bằng phương pháp thủy nhiệt. Nhiệt độ thủy nhiệt được khảo sát ở 180 oC trong 12 giờ. Các đặc trưng vật liệu đã được khảo sát bằng các phương pháp đo XRD, SEM, UV-Vis rắn. Kết quả cho thấy, các vật liệu tổng hợp được đều có kích thước hạt tinh thể nhỏ, mịn cỡ nano-mét (4,56,5 nm). Các mẫu TiO2 pha tạp bởi La3+ đã có sự chuyển dịch về phía bước sóng dài hơn ( 400500 nm) so với mẫu TiO2 không pha tạp ( 380 nm). Năng lượng vùng cấm quang Eg của các mẫu TiO2 pha tạp được giảm xuống tới 3,043...

  • Expression of CYP2E1 gene in paint workers occupationally exposed to organic solvents.pdf.jpg
  • Article


  • Authors: Nguyễn, Thị Hiền; Đỗ, Thị Cẩm Nhung; Nguyễn, Phú Hùng; Bùi, Phương Thuận; Nguyễn, Quang Huy (2019)

  • Người lao động trong ngành sơn dễ bị phơi nhiễm với dung môi hữu cơ, đặc biệt là nhóm chất benzen, toluen, ethylbenzen và xylen (BTEX). CYP2E1 là gen mã hóa enzym CYP2E1 đóng vai trò quan trọng trong quá trình chuyển hóa nhóm chất BTEX giúp cơ thể thải độc. Mức độ biểu hiện của gen CYP2E1 là một chỉ thị sinh học có độ nhạy, chính xác cao và được một số tác giả đề xuất làm chỉ số giám sát sinh học cho người lao động có tiếp xúc nghề nghiệp với nhóm chất BTEX. Trong bài báo này, chúng tôi phân tích mức độ biểu hiện của gen CYP2E1 ở 118 người, trong đó 73 người làm việc tại công ty sản xuất sơn có tiếp xúc với BTEX và 45 người không tiếp xúc với BTEX thông qua phương pháp Real tim...

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