Nguyen Gia Nam (FGW HN) (original) (raw)

Papers by Nguyen Gia Nam (FGW HN)

Meeting Abstracts of the Physical Society of Japan (Nihon Butsuri Gakkai koen gaiyoshu), 2009

Sixteen sesquiterpenoids (<b>1 </b>–<b> 16</b>), including two new compou... more Sixteen sesquiterpenoids (<b>1 </b>–<b> 16</b>), including two new compounds namely saussucostusosides A and B (<b>1</b> and <b>2</b>), were isolated from the roots of <i>Saussurea costus</i> by various chromatographic separations. Their structures were elucidated by 1 D and 2 D NMR and HR-QTOF-MS experiments. Among isolated compounds, costunlide (<b>6</b>), 3<i>β</i>-[4-hydroxymethacryloyloxy]-8<i>α</i>-hydroxycostunolide (<b>10</b>) and 11<i>β</i>,13-dihydrozaluzanin C (<b>16</b>) exhibited potent inhibitory effects on LPS-induced NO production in RAW264.7 cells with IC₅₀ values of 7.08 ± 0.34, 2.40 ± 0.06 and 5.55 ± 0.24 µM, respectively.

RSC Advances, 2020

The development of Mg–5Al–4Sn–xSr alloys with α-grain reduction, refined precipitates and pitting... more The development of Mg–5Al–4Sn–xSr alloys with α-grain reduction, refined precipitates and pitting corrosion resistance by die casting.

RSC Advances, 2020

The vascular endothelial growth factor 165 (VEGF165) is a quintessential biomarker in cancers.

VNU Journal of Science: Policy and Management Studies, 2019

Traditional economic development often faces the trade-off between economic growth and environmen... more Traditional economic development often faces the trade-off between economic growth and environmental quality. That is because of the linear approach, which relies on resource exploitation to make products, consumption and then dispose, resulting in natural resource degradation and waste increase. Circular economy is a change approach, towards restoration and regeneration, thereby reducing the dependence on natural resources and limiting emission, while not underestimating economic development. This paper conducts an in-depth analysis of the difference between the linear economy and circular economy. Moreover, it discusses the necessity of the transition from the linear economy to circular economy, which has recently become a trend in many countries around the world.

Natural Product Communications, 2010

A new lignan dimer, bilariciresinol (1), was isolated from the leaves of Mallotus philippensis, a... more A new lignan dimer, bilariciresinol (1), was isolated from the leaves of Mallotus philippensis, along with platanoside (2), isovitexin (3), dihydromyricetin (4), bergenin (5), 4 -O-galloylbergenin (6), and pachysandiol A (7). Their structures were elucidated by spectroscopic experiments including 1D and 2D NMR and FTICR-MS.

Natural Product Communications, 2014

Six secondary metabolites, including two novel iridoids, longifolides A (1) and B (2), were isola... more Six secondary metabolites, including two novel iridoids, longifolides A (1) and B (2), were isolated by various chromatographic methods from a methanol extract of branches and leaves of Morinda longifolia Craib. The structures of the compounds were determined on the basis of NMR spectroscopic (1H and 13C NMR, HSQC, HMBC, 1H-1H COSY, NOESY) and FTICR-MS data, as well as by comparison of them with literature values.

Natural Product Communications, 2014

Sea cucumbers have been used as a dietary delicacy and important ingredient in Asian traditional ... more Sea cucumbers have been used as a dietary delicacy and important ingredient in Asian traditional medicine and functional foods over many centuries. Using combined chromatographic methods, six triterpene saponins (1-6), including a new compound, stichloroside F (1), were isolated from a methanol extract of the sea cucumber Stichopus chloronotus Brandt. Their structures were determined on the basis of spectroscopic (1H and 13C NMR, HSQC, HMBC, 1H-1H COSY, ROESY) and FTICR-MS data and by comparison with literature values.

Natural Product Communications, 2013

Two new butenolide and pentenolide derivatives, dysideolides A-B, were isolated from the marine s... more Two new butenolide and pentenolide derivatives, dysideolides A-B, were isolated from the marine sponge Dysidea cinerea. Their structures were determined by the combination of spectroscopic and chemical methods, including 1D- and 2D-NMR spectroscopy, and CD spectra, as well as by comparing with the NMR data reported in the literature.

Natural Product Communications, 2009

From the methanol extract of Dracaena cambodiana roots two unusual 22S-spirostane steroids (1β,3β... more From the methanol extract of Dracaena cambodiana roots two unusual 22S-spirostane steroids (1β,3β,14α,20R,22S,25R)-spirost-5-ene-1,3, 14-triol (1) and (1β,3β,14α,15α,20R,22S,25R)-spirost-5-ene-tetrol (2) have been isolated, together with a known 22R-spirostane compound, namogenin B (3). Their structures were elucidated by spectroscopic and spectrometric methods, including HRMS and extensive 1D and 2D NMR spectroscopy. Compound 1 showed significant antimicrobial activity against Pseudomonas aeruginosa, Staphylococcus aureus and Fusarium oxysporum, with MIC values of 45.0, 25.0 and 50.0 μg/mL, respectively.

Natural Product Communications, 2009

Phytochemical study of the methanol extract of Mallotus anisopodus led to the isolation of two ne... more Phytochemical study of the methanol extract of Mallotus anisopodus led to the isolation of two new megastigmane sulphonoglucosides, namely anisoposides A (1) and B (2), along with junipetrioloside A (3), bergenin (4), α-tocopherol, and N1-methyl-2-pyridone-5-carboxamide. Their structures were deduced by spectroscopic and spectrometric methods including 1D-, 2D-NMR, ESIMS, and HRESIMS.

Chemical & pharmaceutical bulletin, Jan 21, 2018

Seven anthraquinones including two new compounds namely capillasterquinones A and B (1 and 2) and... more Seven anthraquinones including two new compounds namely capillasterquinones A and B (1 and 2) and one new butenolide namely capillasterolide (8) were isolated and structurally elucidated from the crinoid Capillaster multiradiatus. The inhibitory effect of compounds 1-8 on lipopolysaccharide (LPS)-induced nitric oxide (NO) production as well as inhibition of 1 on expressions of iNOS and COX-2 proteins in RAW264.7 cells were also evaluated. As the obtained results, capillasterquinone A (1) showed strong NO production inhibitory activity with an IC of 5.89 ± 0.11 µM. In addition, compound 1 reduced the LPS-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) expressions in a dose-dependent manner.

Taiwanese Journal of Mathematics, 2006

This paper deals with the classical distance function to closed sets and its extension to the cas... more This paper deals with the classical distance function to closed sets and its extension to the case of set-valued mappings. It has been well recognized that the distance functions play a crucial role in many aspects of variational analysis, optimization, and their applications. One of the most remarkable properties of even the classical distance function is its intrinsic nonsmoothness, which requires the usage of generalized differential constructions for its study and applications. In this paper we present new results in theser directions using mostly the generalized differential constructions introduced earlier by the first author, as well as their recent modifications. We pay the main attention to studying subgradients of the distance functions in out-of-set points, which is essentially more involved in comparison with the inset case. Most of the results obtained are new in both finite-dimensional and infinite-dimensional settings; some of them of provide essential improvements of known results even for convex sets.

Vietnam Social Sciences, 2002

The Thai Journal of Veterinary Medicine, Dec 15, 2014

The present study was to investigate the effects of low intensity laser therapy (LILT) on the hea... more The present study was to investigate the effects of low intensity laser therapy (LILT) on the healing of rabbit tibial defects. Circular defects were perforated at the medial site of tibial crests on both hind legs of 18 male New Zealand White rabbits. The defects were randomly allocated into 3 groups (n=12): 1) defects irradiated with LILT, at 4 J/cm 2 (LS4); 2) defects irradiated with LILT, at 20 J/cm 2 (LS20), and 3) defects receiving sham treatment (control group). Irradiation began 24 h after surgery, and repeated every 48 h, with a total of 8 sessions. In the 3 rd and 6 th weeks after surgery, the rabbits were euthanized, and the healing of defects was assessed by cone beam computed tomography, qualitative and quantitative histological techniques. Results showed that the 2 dosages of LILT similarly and significantly enhanced bone healing by increasing the bone area fraction in the 3 rd week and the density of newly formed bone tissues in the 6 th week after surgery. In conclusion, our findings support the hypothesis that LILT could improve the healing of the rabbit tibial defects via increased bone formation. The equal positive effects of the 2 settings suggest that the lower dosage of LILT may be more preferable and practical than the higher one in bio-stimulation of healing of bone fractures/defects.

Nmec 2012 Proceedings of the First International Workshop on Nano Materials For Energy Conversion and Fuel Cell, 2012

International Journal of Communication Networks and Information Security, Mar 19, 2014

Cognitive radio and femtocell are promising technologies which can satisfy the requirements of fu... more Cognitive radio and femtocell are promising technologies which can satisfy the requirements of future mobile communications in terms of dynamic spectrum sharing and high user density areas. Providing quality-of-service (QoS) guaranteed realtime services is challenging issue of future cognitive cellularfemtocell mobile networks. In this paper, we introduce a user's QoS management mechanism used to protect SINR of macro users from QoS violation caused by femtocell users. We design a novel uplink channel allocation scheme (denoted as "flexible scheme") for real-time connections. The scheme uses the information of interference level and channel occupancy collected at cognitive femtocell access points and their covering macro base station (MBS) and apply relevant selection criteria to select an appropriate channel which causes the minimums interference to macro users of the covering MBS. Performance results prove that comparing with femtocell-access-point (FAP)-based and MBS-based uplink channel allocation schemes, the novel "flexible scheme" can provide lower unsuccessful probability of new connection requests.

Several optimization schemes have been known for convex optimization problems. However, numerical... more Several optimization schemes have been known for convex optimization problems. However, numerical algorithms for solving nonconvex optimization problems are still underdeveloped. A progress to go beyond convexity was made by considering the class of functions representable as differences of convex functions. In this paper, we introduce a generalized proximal point algorithm to minimize the difference of a nonconvex function and a convex function. We also study convergence results of this algorithm under the main assumption that the objective function satisfies the Kurdyka-Lojasiewicz property.

Meeting Abstracts of the Physical Society of Japan (Nihon Butsuri Gakkai koen gaiyoshu), 2009

Sixteen sesquiterpenoids (<b>1 </b>–<b> 16</b>), including two new compou... more Sixteen sesquiterpenoids (<b>1 </b>–<b> 16</b>), including two new compounds namely saussucostusosides A and B (<b>1</b> and <b>2</b>), were isolated from the roots of <i>Saussurea costus</i> by various chromatographic separations. Their structures were elucidated by 1 D and 2 D NMR and HR-QTOF-MS experiments. Among isolated compounds, costunlide (<b>6</b>), 3<i>β</i>-[4-hydroxymethacryloyloxy]-8<i>α</i>-hydroxycostunolide (<b>10</b>) and 11<i>β</i>,13-dihydrozaluzanin C (<b>16</b>) exhibited potent inhibitory effects on LPS-induced NO production in RAW264.7 cells with IC₅₀ values of 7.08 ± 0.34, 2.40 ± 0.06 and 5.55 ± 0.24 µM, respectively.

RSC Advances, 2020

The development of Mg–5Al–4Sn–xSr alloys with α-grain reduction, refined precipitates and pitting... more The development of Mg–5Al–4Sn–xSr alloys with α-grain reduction, refined precipitates and pitting corrosion resistance by die casting.

RSC Advances, 2020

The vascular endothelial growth factor 165 (VEGF165) is a quintessential biomarker in cancers.

VNU Journal of Science: Policy and Management Studies, 2019

Traditional economic development often faces the trade-off between economic growth and environmen... more Traditional economic development often faces the trade-off between economic growth and environmental quality. That is because of the linear approach, which relies on resource exploitation to make products, consumption and then dispose, resulting in natural resource degradation and waste increase. Circular economy is a change approach, towards restoration and regeneration, thereby reducing the dependence on natural resources and limiting emission, while not underestimating economic development. This paper conducts an in-depth analysis of the difference between the linear economy and circular economy. Moreover, it discusses the necessity of the transition from the linear economy to circular economy, which has recently become a trend in many countries around the world.

Natural Product Communications, 2010

A new lignan dimer, bilariciresinol (1), was isolated from the leaves of Mallotus philippensis, a... more A new lignan dimer, bilariciresinol (1), was isolated from the leaves of Mallotus philippensis, along with platanoside (2), isovitexin (3), dihydromyricetin (4), bergenin (5), 4 -O-galloylbergenin (6), and pachysandiol A (7). Their structures were elucidated by spectroscopic experiments including 1D and 2D NMR and FTICR-MS.

Natural Product Communications, 2014

Six secondary metabolites, including two novel iridoids, longifolides A (1) and B (2), were isola... more Six secondary metabolites, including two novel iridoids, longifolides A (1) and B (2), were isolated by various chromatographic methods from a methanol extract of branches and leaves of Morinda longifolia Craib. The structures of the compounds were determined on the basis of NMR spectroscopic (1H and 13C NMR, HSQC, HMBC, 1H-1H COSY, NOESY) and FTICR-MS data, as well as by comparison of them with literature values.

Natural Product Communications, 2014

Sea cucumbers have been used as a dietary delicacy and important ingredient in Asian traditional ... more Sea cucumbers have been used as a dietary delicacy and important ingredient in Asian traditional medicine and functional foods over many centuries. Using combined chromatographic methods, six triterpene saponins (1-6), including a new compound, stichloroside F (1), were isolated from a methanol extract of the sea cucumber Stichopus chloronotus Brandt. Their structures were determined on the basis of spectroscopic (1H and 13C NMR, HSQC, HMBC, 1H-1H COSY, ROESY) and FTICR-MS data and by comparison with literature values.

Natural Product Communications, 2013

Two new butenolide and pentenolide derivatives, dysideolides A-B, were isolated from the marine s... more Two new butenolide and pentenolide derivatives, dysideolides A-B, were isolated from the marine sponge Dysidea cinerea. Their structures were determined by the combination of spectroscopic and chemical methods, including 1D- and 2D-NMR spectroscopy, and CD spectra, as well as by comparing with the NMR data reported in the literature.

Natural Product Communications, 2009

From the methanol extract of Dracaena cambodiana roots two unusual 22S-spirostane steroids (1β,3β... more From the methanol extract of Dracaena cambodiana roots two unusual 22S-spirostane steroids (1β,3β,14α,20R,22S,25R)-spirost-5-ene-1,3, 14-triol (1) and (1β,3β,14α,15α,20R,22S,25R)-spirost-5-ene-tetrol (2) have been isolated, together with a known 22R-spirostane compound, namogenin B (3). Their structures were elucidated by spectroscopic and spectrometric methods, including HRMS and extensive 1D and 2D NMR spectroscopy. Compound 1 showed significant antimicrobial activity against Pseudomonas aeruginosa, Staphylococcus aureus and Fusarium oxysporum, with MIC values of 45.0, 25.0 and 50.0 μg/mL, respectively.

Natural Product Communications, 2009

Phytochemical study of the methanol extract of Mallotus anisopodus led to the isolation of two ne... more Phytochemical study of the methanol extract of Mallotus anisopodus led to the isolation of two new megastigmane sulphonoglucosides, namely anisoposides A (1) and B (2), along with junipetrioloside A (3), bergenin (4), α-tocopherol, and N1-methyl-2-pyridone-5-carboxamide. Their structures were deduced by spectroscopic and spectrometric methods including 1D-, 2D-NMR, ESIMS, and HRESIMS.

Chemical & pharmaceutical bulletin, Jan 21, 2018

Seven anthraquinones including two new compounds namely capillasterquinones A and B (1 and 2) and... more Seven anthraquinones including two new compounds namely capillasterquinones A and B (1 and 2) and one new butenolide namely capillasterolide (8) were isolated and structurally elucidated from the crinoid Capillaster multiradiatus. The inhibitory effect of compounds 1-8 on lipopolysaccharide (LPS)-induced nitric oxide (NO) production as well as inhibition of 1 on expressions of iNOS and COX-2 proteins in RAW264.7 cells were also evaluated. As the obtained results, capillasterquinone A (1) showed strong NO production inhibitory activity with an IC of 5.89 ± 0.11 µM. In addition, compound 1 reduced the LPS-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) expressions in a dose-dependent manner.

Taiwanese Journal of Mathematics, 2006

This paper deals with the classical distance function to closed sets and its extension to the cas... more This paper deals with the classical distance function to closed sets and its extension to the case of set-valued mappings. It has been well recognized that the distance functions play a crucial role in many aspects of variational analysis, optimization, and their applications. One of the most remarkable properties of even the classical distance function is its intrinsic nonsmoothness, which requires the usage of generalized differential constructions for its study and applications. In this paper we present new results in theser directions using mostly the generalized differential constructions introduced earlier by the first author, as well as their recent modifications. We pay the main attention to studying subgradients of the distance functions in out-of-set points, which is essentially more involved in comparison with the inset case. Most of the results obtained are new in both finite-dimensional and infinite-dimensional settings; some of them of provide essential improvements of known results even for convex sets.

Vietnam Social Sciences, 2002

The Thai Journal of Veterinary Medicine, Dec 15, 2014

The present study was to investigate the effects of low intensity laser therapy (LILT) on the hea... more The present study was to investigate the effects of low intensity laser therapy (LILT) on the healing of rabbit tibial defects. Circular defects were perforated at the medial site of tibial crests on both hind legs of 18 male New Zealand White rabbits. The defects were randomly allocated into 3 groups (n=12): 1) defects irradiated with LILT, at 4 J/cm 2 (LS4); 2) defects irradiated with LILT, at 20 J/cm 2 (LS20), and 3) defects receiving sham treatment (control group). Irradiation began 24 h after surgery, and repeated every 48 h, with a total of 8 sessions. In the 3 rd and 6 th weeks after surgery, the rabbits were euthanized, and the healing of defects was assessed by cone beam computed tomography, qualitative and quantitative histological techniques. Results showed that the 2 dosages of LILT similarly and significantly enhanced bone healing by increasing the bone area fraction in the 3 rd week and the density of newly formed bone tissues in the 6 th week after surgery. In conclusion, our findings support the hypothesis that LILT could improve the healing of the rabbit tibial defects via increased bone formation. The equal positive effects of the 2 settings suggest that the lower dosage of LILT may be more preferable and practical than the higher one in bio-stimulation of healing of bone fractures/defects.

Nmec 2012 Proceedings of the First International Workshop on Nano Materials For Energy Conversion and Fuel Cell, 2012

International Journal of Communication Networks and Information Security, Mar 19, 2014

Cognitive radio and femtocell are promising technologies which can satisfy the requirements of fu... more Cognitive radio and femtocell are promising technologies which can satisfy the requirements of future mobile communications in terms of dynamic spectrum sharing and high user density areas. Providing quality-of-service (QoS) guaranteed realtime services is challenging issue of future cognitive cellularfemtocell mobile networks. In this paper, we introduce a user's QoS management mechanism used to protect SINR of macro users from QoS violation caused by femtocell users. We design a novel uplink channel allocation scheme (denoted as "flexible scheme") for real-time connections. The scheme uses the information of interference level and channel occupancy collected at cognitive femtocell access points and their covering macro base station (MBS) and apply relevant selection criteria to select an appropriate channel which causes the minimums interference to macro users of the covering MBS. Performance results prove that comparing with femtocell-access-point (FAP)-based and MBS-based uplink channel allocation schemes, the novel "flexible scheme" can provide lower unsuccessful probability of new connection requests.

Several optimization schemes have been known for convex optimization problems. However, numerical... more Several optimization schemes have been known for convex optimization problems. However, numerical algorithms for solving nonconvex optimization problems are still underdeveloped. A progress to go beyond convexity was made by considering the class of functions representable as differences of convex functions. In this paper, we introduce a generalized proximal point algorithm to minimize the difference of a nonconvex function and a convex function. We also study convergence results of this algorithm under the main assumption that the objective function satisfies the Kurdyka-Lojasiewicz property.