Thi Nguyen - Academia.edu (original) (raw)

Papers by Thi Nguyen

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2015

ABSTRACT Doxorubicin (DOX) is one of the most effective anticancer drugs for treating many types ... more ABSTRACT Doxorubicin (DOX) is one of the most effective anticancer drugs for treating many types of cancer. However, the clinical applications of DOX were hindered because of serious side-effects resulting from the unselective delivery to cancer cell including congestive heart failure, chronic cardiomyopathy and drug resistance. Recently, it has been demonstrated that loading anti-cancer drugs onto drug delivery nanosystems helps to maximize therapeutic efficiency and minimize unwanted side-effects via passive and active targeting mechanisms. In this study we prepared folate decorated DOX loaded PLA-TPGS nanoparticles with the aim of improving the potential as well as reducing the side-effects of DOX. Characteristics of nanoparticles were investigated by field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS) method and Fourier transform infrared spectroscopy (FTIR). Anticancer activity of the nanoparticles was evaluated through cytotoxicity and cellular uptake assays on HeLa and HT29 cancer cell lines. The results showed that prepared drug delivery system had size around 100 nm and exhibited higher cytotoxicity and cellular uptake on both tested HeLa and HT29 cells.

Cytotoxic T lymphocytes (CTLs) play a vital part in controlling viral replication during human vi... more Cytotoxic T lymphocytes (CTLs) play a vital part in controlling viral replication during human viral infections. Most studies in human infections have focused on CTL specificities in chronic infection and few data exist regarding the specificity of the initial CTL response induced in acute infection. In this study, HIV-1 infection in persons expressing human histocompatibility leukocyte antigen (HLA)-A * 0201 was used as a means of addressing this issue. In chronic infection, the dominant HLA-A * 0201-restricted CTL response is directed towards the epitope SLYNTVATL ("SL9") in p17 Gag (residues 77-85). This epitope is targeted by 75% of HLA-A * 0201-positive adults, and the magnitude of this A * 0201-SL9 response shows a strong negative association with viral load in progressive infection. Despite using the highly sensitive peptide-major histocompatibility complex tetramer and intracellular cytokine assays, responses to the SL9 epitope were not detectable in any of 11 HLA-A * 0201-positive subjects with acute HIV-1 infection ( P ϭ 2 ϫ 10 Ϫ 6 ), even when assays were repeated using the SL9 peptide variant that was encoded by their autologous virus. In contrast, multiple responses (median 3) to other epitopes were evident in 7 of the 11 A * 0201-positive subjects. Longitudinal study of two subjects confirmed that the A * 0201-SL9 response emerged later than other CTL responses, and after viral set point had been reached. Together, these data show that the CTL responses that are present and that even may dominate in chronic infection may differ substantially from those that constitute the initial antiviral CTL response. This finding is an important consideration in vaccine design and in the evaluation of vaccine candidates.

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2013

CuO nanocrystals were prepared by thermal decomposition of Cu-oxalate at 400 • C; then CuO/TiO 2 ... more CuO nanocrystals were prepared by thermal decomposition of Cu-oxalate at 400 • C; then CuO/TiO 2 core/shell nanocrystals were formed via the hydrolysis of titanium isopropoxide (TIP) on the surface of CuO nanocrystals. The characteristics of the synthesized nanocrystals were systematically studied using appropriate techniques, namely the morphology by using scanning electron microscopy (SEM), and the crystalline structure by x-ray powder diffraction (XRD) and Raman spectroscopy. The structure, shape and size of the CuO and CuO/TiO 2 nanocrystals could be tuned by changing various technological parameters: (i) the reaction/growth time (from several minutes to several hours), (ii) reaction temperature (from room temperature to 90 • C) and (iii) the molar ratios of the precursors. The results showed that the reaction temperature and the molar ratio of the precursors play important roles in controlling the morphology and size of both CuO and CuO/TiO 2 nanocrystals. With increasing reaction temperature, nano-CuO evolved from spherical shaped nanoparticles to microspheres. By shelling the large-bandgap TiO 2 layers on CuO nanocrystals, the core/shell structure is formed and the narrow-bandgap nano-CuO core is expected to be resistant to photocorrosion.

2013 International Conference on Computing, Management and Telecommunications (ComManTel), 2013

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2012

Curcumin (Cur), extracted from the Curcuma longa L. plant, is well known for its anti-tumor, anti... more Curcumin (Cur), extracted from the Curcuma longa L. plant, is well known for its anti-tumor, anti-oxidant, anti-inflammatory and anti-bacterial properties. Nanofiber mats of polylactic acid (PLA) loading Cur (5 wt%) were fabricated by electrospinning (e-spinning). Morphology and structure of the fibers were characterized by field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared (FTIR) spectroscopy, respectively. The diameters of the obtained fibers varied from 200 to 300 nm. The release capacity of curcumin from curcumin-loaded PLA fibers was investigated in phosphate buffer saline (PBS) containing ethanol. After 24 h, 50% of the curcumin was released from curcumin-loaded PLA fibers. These results of electrospun (e-spun) fibers exhibit the potential for biomedical application.

The 8th IEEE International Workshop on Advanced Motion Control, 2004. AMC '04., 2004

Ship motion is a complex controlled process with several hydrodynamic parameters that vary in wid... more Ship motion is a complex controlled process with several hydrodynamic parameters that vary in wide ranges with respect to ship load condition, speed and surrounding conditions (such as wind, current, tide, etc.). Therefore, to effectively control ships in a designed track is always an important task for ship masters. This paper presents an effective adaptive autopilot for ships that ensure

OECD Working Papers on International Investment, 2004

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2011

The solvothermal reactions of 1,4-bezenedicarboxylic acid (H 2 BDC) or azobenzene-4,4 -dicarboxyl... more The solvothermal reactions of 1,4-bezenedicarboxylic acid (H 2 BDC) or azobenzene-4,4 -dicarboxylic acid (H 2 ABD) with zinc ions/clusters lead to the formation of four crystalline materials. All of these compounds were characterized by x-ray diffraction, optical microscopy, thermo-gravimetric analysis and nitrogen adsorption. Block-shaped crystals (BZ1) with various shapes and sizes were obtained at H 2 BDC : Zn mole ratio of 1:1 and H 2 BDC concentration of 0.1 M. At more dilute H 2 BDC concentration of 0.01 M and H 2 BDC : Zn mole ratio of 1 : 4, the reaction product was cubic crystals (BZ2) with a size of 250 µm. In the H 2 ABD system, flat-plate-like crystals (AZ1) were obtained at H 2 ABD : Zn mole ratio of 1 : 1 and H 2 ABD concentration of 0.01 M. Meanwhile, thick-block-like crystals (AZ2) were formed at the same H 2 ABD : Zn mole ratio but at 0.004 M H 2 ABD. The Langmuir surface area (S Lang ) of the materials was remarkable, enhanced by diluting the reaction solution. For the compounds synthesized in N ,N -dimethylformamide (DMF), S Lang increased from 304.6 m 2 g −1 for BZ1 to 2631 m 2 g −1 for BZ2 and from 475.8 m 2 g −1 for AZ1 to 3428 m 2 g −1 for AZ2. Meanwhile, BZ2 synthesized in N ,N -diethylformamide (BZ2/DEF) got the highest S Lang of 4330 m 2 g −1 . Both AZ2 and BZ2 materials were stable up to 400 • C.

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2013

This paper presents our recent research results on synthesis and bioapplications of dye-doped sil... more This paper presents our recent research results on synthesis and bioapplications of dye-doped silica-based nanoparticles. The dye-doped water soluble organically modified silicate (ORMOSIL) nanoparticles (NPs) with the size of 15-100 nm were synthesized by modified Stöber method from methyltriethoxysilane CH 3 Si(OCH 3 ) 3 precursor (MTEOS). Because thousands of fluorescent dye molecules are encapsulated in the silica-based matrix, the dye-doped nanoparticles are extremely bright and photostable. Their surfaces were modified with bovine serum albumin (BSA) and biocompatible chemical reagents. The highly intensive luminescent nanoparticles were combined with specific bacterial and breast cancer antigen antibodies. The antibody-conjugated nanoparticles can identify a variety of bacterium, such as Escherichia coli O157:H7, through antibody-antigen interaction and recognition. A highly sensitive breast cancer cell detection has been achieved with the anti-HER2 monoclonal antibody-nanoparticles complex. These results demonstrate the potential to apply these fluorescent nanoparticles in various biodetection systems.

Protein Expression and Purification, 2013

A gene coding for an endo-b-1,4-xylanase (XlnA) (glycosyl hydrolase family 10) from Aspergillus n... more A gene coding for an endo-b-1,4-xylanase (XlnA) (glycosyl hydrolase family 10) from Aspergillus niger DSM 1957 was cloned and sequenced. The cDNA sequence (984 bp) and its putative endoxylanase (327 aa protein with a predicted molecular mass of 35.5 kDa and pI 6.23) showed 91.3-99.5% and 96.3-99.1% identities with cDNA sequences and their corresponding endoxylanases from A. niger strains from GenBank, respectively. The cDNA was expressed in Pichia pastoris GS115 under the control of AOX1 promoter at a level of 46.4 U/ml culture supernatant, after 144 h of growth at 30°C in YP medium induced with 0.5% (v/v) of methanol. The molecular mass of the purified XlnA determined by SDS-PAGE was 35.5 kDa with a specific activity of 808.5 U/mg towards 1% (w/v) of birch wood xylan. Temperature and pH optimum were observed at 50°C and pH 7.0, respectively. The enzyme was stable over a temperature range of 25-40°C and at pH range of 4.5-8.5 and resistant to Tween 80 and acetone. The K m and V max value obtained for the purified xylanase were 25.5 mg/ml and 5000 lmol/min/mg protein with birch wood xylan as substrate, respectively. The xylanase was free of cellulase and mannanase activity but highly active towards birch wood xylan. The major products of the birch wood xylan hydrolysis were predicted as xylotriose, xylotetraose, and xylopentose. The biochemical characteristics suggested that the recombinant xylanase has a potential application, including use as a feed enzyme.

Environmental Science & Technology, 2001

This is the first publication on arsenic contamination of the Red River alluvial tract in the cit... more This is the first publication on arsenic contamination of the Red River alluvial tract in the city of Hanoi and in the surrounding rural districts. Due to naturally occurring organic matter in the sediments, the

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2015

ABSTRACT Doxorubicin (DOX) is one of the most effective anticancer drugs for treating many types ... more ABSTRACT Doxorubicin (DOX) is one of the most effective anticancer drugs for treating many types of cancer. However, the clinical applications of DOX were hindered because of serious side-effects resulting from the unselective delivery to cancer cell including congestive heart failure, chronic cardiomyopathy and drug resistance. Recently, it has been demonstrated that loading anti-cancer drugs onto drug delivery nanosystems helps to maximize therapeutic efficiency and minimize unwanted side-effects via passive and active targeting mechanisms. In this study we prepared folate decorated DOX loaded PLA-TPGS nanoparticles with the aim of improving the potential as well as reducing the side-effects of DOX. Characteristics of nanoparticles were investigated by field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS) method and Fourier transform infrared spectroscopy (FTIR). Anticancer activity of the nanoparticles was evaluated through cytotoxicity and cellular uptake assays on HeLa and HT29 cancer cell lines. The results showed that prepared drug delivery system had size around 100 nm and exhibited higher cytotoxicity and cellular uptake on both tested HeLa and HT29 cells.

Cytotoxic T lymphocytes (CTLs) play a vital part in controlling viral replication during human vi... more Cytotoxic T lymphocytes (CTLs) play a vital part in controlling viral replication during human viral infections. Most studies in human infections have focused on CTL specificities in chronic infection and few data exist regarding the specificity of the initial CTL response induced in acute infection. In this study, HIV-1 infection in persons expressing human histocompatibility leukocyte antigen (HLA)-A * 0201 was used as a means of addressing this issue. In chronic infection, the dominant HLA-A * 0201-restricted CTL response is directed towards the epitope SLYNTVATL ("SL9") in p17 Gag (residues 77-85). This epitope is targeted by 75% of HLA-A * 0201-positive adults, and the magnitude of this A * 0201-SL9 response shows a strong negative association with viral load in progressive infection. Despite using the highly sensitive peptide-major histocompatibility complex tetramer and intracellular cytokine assays, responses to the SL9 epitope were not detectable in any of 11 HLA-A * 0201-positive subjects with acute HIV-1 infection ( P ϭ 2 ϫ 10 Ϫ 6 ), even when assays were repeated using the SL9 peptide variant that was encoded by their autologous virus. In contrast, multiple responses (median 3) to other epitopes were evident in 7 of the 11 A * 0201-positive subjects. Longitudinal study of two subjects confirmed that the A * 0201-SL9 response emerged later than other CTL responses, and after viral set point had been reached. Together, these data show that the CTL responses that are present and that even may dominate in chronic infection may differ substantially from those that constitute the initial antiviral CTL response. This finding is an important consideration in vaccine design and in the evaluation of vaccine candidates.

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2013

CuO nanocrystals were prepared by thermal decomposition of Cu-oxalate at 400 • C; then CuO/TiO 2 ... more CuO nanocrystals were prepared by thermal decomposition of Cu-oxalate at 400 • C; then CuO/TiO 2 core/shell nanocrystals were formed via the hydrolysis of titanium isopropoxide (TIP) on the surface of CuO nanocrystals. The characteristics of the synthesized nanocrystals were systematically studied using appropriate techniques, namely the morphology by using scanning electron microscopy (SEM), and the crystalline structure by x-ray powder diffraction (XRD) and Raman spectroscopy. The structure, shape and size of the CuO and CuO/TiO 2 nanocrystals could be tuned by changing various technological parameters: (i) the reaction/growth time (from several minutes to several hours), (ii) reaction temperature (from room temperature to 90 • C) and (iii) the molar ratios of the precursors. The results showed that the reaction temperature and the molar ratio of the precursors play important roles in controlling the morphology and size of both CuO and CuO/TiO 2 nanocrystals. With increasing reaction temperature, nano-CuO evolved from spherical shaped nanoparticles to microspheres. By shelling the large-bandgap TiO 2 layers on CuO nanocrystals, the core/shell structure is formed and the narrow-bandgap nano-CuO core is expected to be resistant to photocorrosion.

2013 International Conference on Computing, Management and Telecommunications (ComManTel), 2013

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2012

Curcumin (Cur), extracted from the Curcuma longa L. plant, is well known for its anti-tumor, anti... more Curcumin (Cur), extracted from the Curcuma longa L. plant, is well known for its anti-tumor, anti-oxidant, anti-inflammatory and anti-bacterial properties. Nanofiber mats of polylactic acid (PLA) loading Cur (5 wt%) were fabricated by electrospinning (e-spinning). Morphology and structure of the fibers were characterized by field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared (FTIR) spectroscopy, respectively. The diameters of the obtained fibers varied from 200 to 300 nm. The release capacity of curcumin from curcumin-loaded PLA fibers was investigated in phosphate buffer saline (PBS) containing ethanol. After 24 h, 50% of the curcumin was released from curcumin-loaded PLA fibers. These results of electrospun (e-spun) fibers exhibit the potential for biomedical application.

The 8th IEEE International Workshop on Advanced Motion Control, 2004. AMC '04., 2004

Ship motion is a complex controlled process with several hydrodynamic parameters that vary in wid... more Ship motion is a complex controlled process with several hydrodynamic parameters that vary in wide ranges with respect to ship load condition, speed and surrounding conditions (such as wind, current, tide, etc.). Therefore, to effectively control ships in a designed track is always an important task for ship masters. This paper presents an effective adaptive autopilot for ships that ensure

OECD Working Papers on International Investment, 2004

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2011

The solvothermal reactions of 1,4-bezenedicarboxylic acid (H 2 BDC) or azobenzene-4,4 -dicarboxyl... more The solvothermal reactions of 1,4-bezenedicarboxylic acid (H 2 BDC) or azobenzene-4,4 -dicarboxylic acid (H 2 ABD) with zinc ions/clusters lead to the formation of four crystalline materials. All of these compounds were characterized by x-ray diffraction, optical microscopy, thermo-gravimetric analysis and nitrogen adsorption. Block-shaped crystals (BZ1) with various shapes and sizes were obtained at H 2 BDC : Zn mole ratio of 1:1 and H 2 BDC concentration of 0.1 M. At more dilute H 2 BDC concentration of 0.01 M and H 2 BDC : Zn mole ratio of 1 : 4, the reaction product was cubic crystals (BZ2) with a size of 250 µm. In the H 2 ABD system, flat-plate-like crystals (AZ1) were obtained at H 2 ABD : Zn mole ratio of 1 : 1 and H 2 ABD concentration of 0.01 M. Meanwhile, thick-block-like crystals (AZ2) were formed at the same H 2 ABD : Zn mole ratio but at 0.004 M H 2 ABD. The Langmuir surface area (S Lang ) of the materials was remarkable, enhanced by diluting the reaction solution. For the compounds synthesized in N ,N -dimethylformamide (DMF), S Lang increased from 304.6 m 2 g −1 for BZ1 to 2631 m 2 g −1 for BZ2 and from 475.8 m 2 g −1 for AZ1 to 3428 m 2 g −1 for AZ2. Meanwhile, BZ2 synthesized in N ,N -diethylformamide (BZ2/DEF) got the highest S Lang of 4330 m 2 g −1 . Both AZ2 and BZ2 materials were stable up to 400 • C.

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2013

This paper presents our recent research results on synthesis and bioapplications of dye-doped sil... more This paper presents our recent research results on synthesis and bioapplications of dye-doped silica-based nanoparticles. The dye-doped water soluble organically modified silicate (ORMOSIL) nanoparticles (NPs) with the size of 15-100 nm were synthesized by modified Stöber method from methyltriethoxysilane CH 3 Si(OCH 3 ) 3 precursor (MTEOS). Because thousands of fluorescent dye molecules are encapsulated in the silica-based matrix, the dye-doped nanoparticles are extremely bright and photostable. Their surfaces were modified with bovine serum albumin (BSA) and biocompatible chemical reagents. The highly intensive luminescent nanoparticles were combined with specific bacterial and breast cancer antigen antibodies. The antibody-conjugated nanoparticles can identify a variety of bacterium, such as Escherichia coli O157:H7, through antibody-antigen interaction and recognition. A highly sensitive breast cancer cell detection has been achieved with the anti-HER2 monoclonal antibody-nanoparticles complex. These results demonstrate the potential to apply these fluorescent nanoparticles in various biodetection systems.

Protein Expression and Purification, 2013

A gene coding for an endo-b-1,4-xylanase (XlnA) (glycosyl hydrolase family 10) from Aspergillus n... more A gene coding for an endo-b-1,4-xylanase (XlnA) (glycosyl hydrolase family 10) from Aspergillus niger DSM 1957 was cloned and sequenced. The cDNA sequence (984 bp) and its putative endoxylanase (327 aa protein with a predicted molecular mass of 35.5 kDa and pI 6.23) showed 91.3-99.5% and 96.3-99.1% identities with cDNA sequences and their corresponding endoxylanases from A. niger strains from GenBank, respectively. The cDNA was expressed in Pichia pastoris GS115 under the control of AOX1 promoter at a level of 46.4 U/ml culture supernatant, after 144 h of growth at 30°C in YP medium induced with 0.5% (v/v) of methanol. The molecular mass of the purified XlnA determined by SDS-PAGE was 35.5 kDa with a specific activity of 808.5 U/mg towards 1% (w/v) of birch wood xylan. Temperature and pH optimum were observed at 50°C and pH 7.0, respectively. The enzyme was stable over a temperature range of 25-40°C and at pH range of 4.5-8.5 and resistant to Tween 80 and acetone. The K m and V max value obtained for the purified xylanase were 25.5 mg/ml and 5000 lmol/min/mg protein with birch wood xylan as substrate, respectively. The xylanase was free of cellulase and mannanase activity but highly active towards birch wood xylan. The major products of the birch wood xylan hydrolysis were predicted as xylotriose, xylotetraose, and xylopentose. The biochemical characteristics suggested that the recombinant xylanase has a potential application, including use as a feed enzyme.

Environmental Science & Technology, 2001

This is the first publication on arsenic contamination of the Red River alluvial tract in the cit... more This is the first publication on arsenic contamination of the Red River alluvial tract in the city of Hanoi and in the surrounding rural districts. Due to naturally occurring organic matter in the sediments, the