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

Papers by Nguyen Tien

Research paper thumbnail of Convergence versus integrability in Birkhoff normal form

Annals of Mathematics, 2005

We show that any analytically integrable Hamiltonian system near an equilibrium point admits a co... more We show that any analytically integrable Hamiltonian system near an equilibrium point admits a convergent Birkhoff normalization. The proof is based on a new, geometric approach to the problem.

Research paper thumbnail of Symplectic Topology of Integrable Hamiltonian Systems, II: Topological Classification

Compositio Mathematica, 2003

The main purpose of this paper is to give a topological and symplectic classification of complete... more The main purpose of this paper is to give a topological and symplectic classification of completely integrable Hamiltonian systems in terms of characteristic classes and other local and global invariants.

Research paper thumbnail of A pharmacokinetic and pharmacodynamic study of intravenous vs oral artesunate in uncomplicated falciparum malaria: Pharmacokinetics of artesunate in falciparum malaria

British Journal of Clinical Pharmacology, 2002

Aims To obtain comprehensive pharmacokinetic and pharmacodynamic data for artesunate (ARTS) and i... more Aims To obtain comprehensive pharmacokinetic and pharmacodynamic data for artesunate (ARTS) and its active metabolite dihydroartemisinin (DHA) following i.v. and oral administration of ARTS to patients with acute, uncomplicated falciparum malaria.Methods Twenty-six Vietnamese patients with falciparum malaria were randomized to receive either i.v. ARTS (120 mg; group 1) or oral ARTS (100 mg; group 2), with the alternative preparation given 8 h later in an open crossover design. Mefloquine (750 mg) was administered at 24 h. Plasma concentrations of ARTS and DHA were determined by h.p.l.c. assay. Pharmacokinetic parameters were calculated by non-compartmental methods. The time to 50% parasite clearance (PCT50 ) was calculated by linear interpolation of parasite density determinations. Linear least squares and multiple linear regression analyses were used to evaluate pharmacokinetic-pharmacodynamic relationships.Results Following i.v. bolus, ARTS had a peak concentration of 29.5 μm (11 mg l−1 ), elimination t1/2=2.7 min, CL=2.33 l h−1 kg−1 and V=0.14 l kg−1. The Cmax for DHA was 9.3 μm (2.64 mg l−1 ), t1/2=40 min, CL=0.75 l h−1 kg−1 and V=0.76 l kg−1. Following oral ARTS, relative bioavailability of DHA was 82%, Cmax was 2.6 μm (0.74 mg l−1 ), t1/2=39 min, and MAT=67 min. Overall, the PCT50 and fever clearance time (FCT) were 6.5 h and 24 h, respectively. There was no correlation between PCT50 or FCT and AUC, Cmax or MRT for DHA.Conclusions Despite rapid clearance of ARTS and DHA in patients with uncomplicated falciparum malaria, prompt parasite and fever clearance were achieved. High relative bioavailability of DHA following oral ARTS administration, and clinical outcomes comparable with those after i.v. ARTS, support the use of the oral formulation in the primary care setting.

Research paper thumbnail of Symplectic topology of integrable Hamiltonian systems, I: Arnold-Liouville with singularities

International Journal of Computer Mathematics, 2001

The classical Arnold-Liouville theorem describes the geometry of an integrable Hamiltonian system... more The classical Arnold-Liouville theorem describes the geometry of an integrable Hamiltonian system near a regular level set of the moment map. Our results describe it near a nondegenerate singular level set: a tubular neighborhood of a connected singular nondegenerate level set, after a normal finite covering, admits a non-complete system of action-angle functions (the number of action functions is equal to the rank of the moment map), and it can be decomposed topologically, together with the associated singular Lagrangian foliation, to a direct product of simplest (codimension 1 and codimension 2) singularities. These results are essential for the global topological study of integrable Hamiltonian systems.

Research paper thumbnail of Some investigation results of the instability of humidity sensors based on alumina and porous silicon materials

Sensors and Actuators B-chemical, 2000

The alumina and porous silicon humidity sensors (PS sensors) have been fabricated in the same str... more The alumina and porous silicon humidity sensors (PS sensors) have been fabricated in the same structure by using the anodic technique. The sensitive films (ie, alumina and porous silicon) were formed on aluminium and silicon substrates by anodization [1]. In this report, the ...

Research paper thumbnail of Lignans with Inhibitory Activity against NFAT Transcription from Schisandra chinensis

Planta Medica, 2003

Seven lignans from Schisandra chinensis were investigated for their inhibitory activity on NFAT t... more Seven lignans from Schisandra chinensis were investigated for their inhibitory activity on NFAT transcription. Both gomisin N (IC 50 : 1.33 +/- 0.05 microM) and schisandrol A (IC 50 : 1.34 +/- 0.05 microM) showed higher activity than gomisin E (IC 50 : 4.73 +/- 0.09 microM), schisandrin A (IC 50 : 7.23 +/- 0.21 microM), schisandrin C (IC 50 : 7.54 +/- 0.22 microM), benzoylisogomisin O (IC 50 : 11.06 +/- 1.02 microM) and schisandrol B (IC 50 : 16.37 +/- 1.00 microM).

Research paper thumbnail of PCR detection and analysis of Pasteurella multocida from the tonsils of slaughtered pigs in Vietnam

Veterinary Microbiology, 2000

A total of 36 tonsil swab samples were collected from healthy swine prior to slaughter at the aba... more A total of 36 tonsil swab samples were collected from healthy swine prior to slaughter at the abattoirs in Can tho and Tien giang provinces of Southern Vietnam. The presence of Pasteurella multocida in these samples was detected by the combination of direct cultivation and isolation, mouse inoculation and the polymerase chain reaction (PM-PCR). P. multocida was detected in 16 samples by PCR, with 17 strains ultimately isolated. All samples were negative for serogroup B by HSB-PCR and conventional serotyping, with isolates identi®ed as A:3, D:1 or D:3. In addition, all samples were determined to be negative for the P. multocida toxin (PMT). Characterisation of isolated P. multocida by REP-PCR and biotyping revealed nine distinct REP pro®les and seven biotypes among the 17 isolates. Some correlation was seen with P. multocida isolated from a previous Australian outbreak of acute swine pasteurellosis, and those isolated from fowl cholera outbreaks in Vietnamese poultry. #

Research paper thumbnail of Symplectic Topology of Integrable Hamiltonian Systems, II: Topological Classification

International Journal of Computer Mathematics, 2000

The classical Arnold-Liouville theorem describes the geometry of an integrable Hamiltonian system... more The classical Arnold-Liouville theorem describes the geometry of an integrable Hamiltonian system near a regular level set of the moment map. Our results describe it near a nondegenerate singular level set: a tubular neighborhood of a connected singular nondegenerate level set, after a normal finite covering, admits a non-complete system of action-angle functions (the number of action functions is equal to the rank of the moment map), and it can be decomposed topologically, together with the associated singular Lagrangian foliation, to a direct product of simplest (codimension 1 and codimension 2) singularities. These results are essential for the global topological study of integrable Hamiltonian systems.

Research paper thumbnail of Con h , h t bao gi

SGTT -4 giờ trước SGTT.VN -Hàng ngày, khoa tâm lý bệnh viện Nhi Đồng 1, TP.HCM tiếp nhận nhiều ph... more SGTT -4 giờ trước SGTT.VN -Hàng ngày, khoa tâm lý bệnh viện Nhi Đồng 1, TP.HCM tiếp nhận nhiều phụ huynh đau khổ vì những hành vi bất thường của con ở mọi lứa tuổi. Những hành vi bất thường đó thường xuất hiện ở trẻ là con một được nuông chiều quá mức, đến nỗi trở thành một vị vua trong gia đình.

Research paper thumbnail of E C 2 1 E A C

Research paper thumbnail of Doko vn-33207-giup-tre-ung-pho-voi-cang-thang

Ngày nay nhiều nghiên cứu đã chỉ ra rằng trẻ em đương đầu với căng thẳng theo cả 2 cách có lợi và... more Ngày nay nhiều nghiên cứu đã chỉ ra rằng trẻ em đương đầu với căng thẳng theo cả 2 cách có lợi và không có lợi cho sức khỏe, trong khi đó chúng không thể đối thoại về những rắc rối của chúng, chúng cần bố mẹ giúp chúng đương đầu với những cảm xúc của chúng. Nhưng điều này không dễ dàng đối với cha mẹ để biết cách giải tỏa với những cảm xúc căng thẳng của con họ. Dưới đây là một vài ý tưởng:

Research paper thumbnail of Convergence versus integrability in Birkhoff normal form

Annals of Mathematics, 2005

We show that any analytically integrable Hamiltonian system near an equilibrium point admits a co... more We show that any analytically integrable Hamiltonian system near an equilibrium point admits a convergent Birkhoff normalization. The proof is based on a new, geometric approach to the problem.

Research paper thumbnail of Symplectic Topology of Integrable Hamiltonian Systems, II: Topological Classification

Compositio Mathematica, 2003

The main purpose of this paper is to give a topological and symplectic classification of complete... more The main purpose of this paper is to give a topological and symplectic classification of completely integrable Hamiltonian systems in terms of characteristic classes and other local and global invariants.

Research paper thumbnail of A pharmacokinetic and pharmacodynamic study of intravenous vs oral artesunate in uncomplicated falciparum malaria: Pharmacokinetics of artesunate in falciparum malaria

British Journal of Clinical Pharmacology, 2002

Aims To obtain comprehensive pharmacokinetic and pharmacodynamic data for artesunate (ARTS) and i... more Aims To obtain comprehensive pharmacokinetic and pharmacodynamic data for artesunate (ARTS) and its active metabolite dihydroartemisinin (DHA) following i.v. and oral administration of ARTS to patients with acute, uncomplicated falciparum malaria.Methods Twenty-six Vietnamese patients with falciparum malaria were randomized to receive either i.v. ARTS (120 mg; group 1) or oral ARTS (100 mg; group 2), with the alternative preparation given 8 h later in an open crossover design. Mefloquine (750 mg) was administered at 24 h. Plasma concentrations of ARTS and DHA were determined by h.p.l.c. assay. Pharmacokinetic parameters were calculated by non-compartmental methods. The time to 50% parasite clearance (PCT50 ) was calculated by linear interpolation of parasite density determinations. Linear least squares and multiple linear regression analyses were used to evaluate pharmacokinetic-pharmacodynamic relationships.Results Following i.v. bolus, ARTS had a peak concentration of 29.5 μm (11 mg l−1 ), elimination t1/2=2.7 min, CL=2.33 l h−1 kg−1 and V=0.14 l kg−1. The Cmax for DHA was 9.3 μm (2.64 mg l−1 ), t1/2=40 min, CL=0.75 l h−1 kg−1 and V=0.76 l kg−1. Following oral ARTS, relative bioavailability of DHA was 82%, Cmax was 2.6 μm (0.74 mg l−1 ), t1/2=39 min, and MAT=67 min. Overall, the PCT50 and fever clearance time (FCT) were 6.5 h and 24 h, respectively. There was no correlation between PCT50 or FCT and AUC, Cmax or MRT for DHA.Conclusions Despite rapid clearance of ARTS and DHA in patients with uncomplicated falciparum malaria, prompt parasite and fever clearance were achieved. High relative bioavailability of DHA following oral ARTS administration, and clinical outcomes comparable with those after i.v. ARTS, support the use of the oral formulation in the primary care setting.

Research paper thumbnail of Symplectic topology of integrable Hamiltonian systems, I: Arnold-Liouville with singularities

International Journal of Computer Mathematics, 2001

The classical Arnold-Liouville theorem describes the geometry of an integrable Hamiltonian system... more The classical Arnold-Liouville theorem describes the geometry of an integrable Hamiltonian system near a regular level set of the moment map. Our results describe it near a nondegenerate singular level set: a tubular neighborhood of a connected singular nondegenerate level set, after a normal finite covering, admits a non-complete system of action-angle functions (the number of action functions is equal to the rank of the moment map), and it can be decomposed topologically, together with the associated singular Lagrangian foliation, to a direct product of simplest (codimension 1 and codimension 2) singularities. These results are essential for the global topological study of integrable Hamiltonian systems.

Research paper thumbnail of Some investigation results of the instability of humidity sensors based on alumina and porous silicon materials

Sensors and Actuators B-chemical, 2000

The alumina and porous silicon humidity sensors (PS sensors) have been fabricated in the same str... more The alumina and porous silicon humidity sensors (PS sensors) have been fabricated in the same structure by using the anodic technique. The sensitive films (ie, alumina and porous silicon) were formed on aluminium and silicon substrates by anodization [1]. In this report, the ...

Research paper thumbnail of Lignans with Inhibitory Activity against NFAT Transcription from Schisandra chinensis

Planta Medica, 2003

Seven lignans from Schisandra chinensis were investigated for their inhibitory activity on NFAT t... more Seven lignans from Schisandra chinensis were investigated for their inhibitory activity on NFAT transcription. Both gomisin N (IC 50 : 1.33 +/- 0.05 microM) and schisandrol A (IC 50 : 1.34 +/- 0.05 microM) showed higher activity than gomisin E (IC 50 : 4.73 +/- 0.09 microM), schisandrin A (IC 50 : 7.23 +/- 0.21 microM), schisandrin C (IC 50 : 7.54 +/- 0.22 microM), benzoylisogomisin O (IC 50 : 11.06 +/- 1.02 microM) and schisandrol B (IC 50 : 16.37 +/- 1.00 microM).

Research paper thumbnail of PCR detection and analysis of Pasteurella multocida from the tonsils of slaughtered pigs in Vietnam

Veterinary Microbiology, 2000

A total of 36 tonsil swab samples were collected from healthy swine prior to slaughter at the aba... more A total of 36 tonsil swab samples were collected from healthy swine prior to slaughter at the abattoirs in Can tho and Tien giang provinces of Southern Vietnam. The presence of Pasteurella multocida in these samples was detected by the combination of direct cultivation and isolation, mouse inoculation and the polymerase chain reaction (PM-PCR). P. multocida was detected in 16 samples by PCR, with 17 strains ultimately isolated. All samples were negative for serogroup B by HSB-PCR and conventional serotyping, with isolates identi®ed as A:3, D:1 or D:3. In addition, all samples were determined to be negative for the P. multocida toxin (PMT). Characterisation of isolated P. multocida by REP-PCR and biotyping revealed nine distinct REP pro®les and seven biotypes among the 17 isolates. Some correlation was seen with P. multocida isolated from a previous Australian outbreak of acute swine pasteurellosis, and those isolated from fowl cholera outbreaks in Vietnamese poultry. #

Research paper thumbnail of Symplectic Topology of Integrable Hamiltonian Systems, II: Topological Classification

International Journal of Computer Mathematics, 2000

The classical Arnold-Liouville theorem describes the geometry of an integrable Hamiltonian system... more The classical Arnold-Liouville theorem describes the geometry of an integrable Hamiltonian system near a regular level set of the moment map. Our results describe it near a nondegenerate singular level set: a tubular neighborhood of a connected singular nondegenerate level set, after a normal finite covering, admits a non-complete system of action-angle functions (the number of action functions is equal to the rank of the moment map), and it can be decomposed topologically, together with the associated singular Lagrangian foliation, to a direct product of simplest (codimension 1 and codimension 2) singularities. These results are essential for the global topological study of integrable Hamiltonian systems.

Research paper thumbnail of Con h , h t bao gi

SGTT -4 giờ trước SGTT.VN -Hàng ngày, khoa tâm lý bệnh viện Nhi Đồng 1, TP.HCM tiếp nhận nhiều ph... more SGTT -4 giờ trước SGTT.VN -Hàng ngày, khoa tâm lý bệnh viện Nhi Đồng 1, TP.HCM tiếp nhận nhiều phụ huynh đau khổ vì những hành vi bất thường của con ở mọi lứa tuổi. Những hành vi bất thường đó thường xuất hiện ở trẻ là con một được nuông chiều quá mức, đến nỗi trở thành một vị vua trong gia đình.

Research paper thumbnail of E C 2 1 E A C

Research paper thumbnail of Doko vn-33207-giup-tre-ung-pho-voi-cang-thang

Ngày nay nhiều nghiên cứu đã chỉ ra rằng trẻ em đương đầu với căng thẳng theo cả 2 cách có lợi và... more Ngày nay nhiều nghiên cứu đã chỉ ra rằng trẻ em đương đầu với căng thẳng theo cả 2 cách có lợi và không có lợi cho sức khỏe, trong khi đó chúng không thể đối thoại về những rắc rối của chúng, chúng cần bố mẹ giúp chúng đương đầu với những cảm xúc của chúng. Nhưng điều này không dễ dàng đối với cha mẹ để biết cách giải tỏa với những cảm xúc căng thẳng của con họ. Dưới đây là một vài ý tưởng: