Ngoc Tuan - Academia.edu (original) (raw)

Papers by Ngoc Tuan

Journal of Magnetism and Magnetic Materials, 2002

The {Tb(Fe0.55Co0.45)1.5/Y0.2Fe0.8}40 multilayers are investigated by X-ray diffraction and SQUID... more The {Tb(Fe0.55Co0.45)1.5/Y0.2Fe0.8}40 multilayers are investigated by X-ray diffraction and SQUID measurements. The results show that in the as-deposited multilayer, the TbFeCo and YFe layers are amorphous. An excellent magnetic softness with a coercivity of 0.3mT was achieved after annealing at 250°C. These novel magnetic properties are associated to the evolution of a nanocrystalline structure in the YFe layers. Different temperature

Trends in Plant Science, 2009

Vegetative desiccation tolerance occurs in a unique group of species termed 'resurrection plants'... more Vegetative desiccation tolerance occurs in a unique group of species termed 'resurrection plants'. Here, we review the molecular genetic, physiological, biochemical, ultrastructural and biophysical studies that have been performed on a variety of resurrection plants to discover the mechanisms responsible for their tolerance. Desiccation tolerance in resurrection plants involves a combination of molecular genetic mechanisms, metabolic and antioxidant systems as well as macromolecular and structural stabilizing processes. We propose that a systems-biology approach coupled with multivariate data analysis is best suited to unraveling the mechanisms responsible for plant desiccation tolerance, as well as their integration with one another. This is of particular relevance to molecular biological engineering strategies for improving plant drought tolerance in important crop species, such as maize (Zea mays) and grapevine (Vitis vinifera).

Physica B-condensed Matter, 2003

MnPd/Co bilayers sputtered onto Si (1 0 0) substrates with varied MnPd thickness have been invest... more MnPd/Co bilayers sputtered onto Si (1 0 0) substrates with varied MnPd thickness have been investigated. Structural characterization of the bilayers was carried out with an X-ray diffractometer and their magnetic properties were measured by a vibrating-sample magnetometer. As-deposited bilayers exhibit large but quite usual exchange-biased coupling, i.e. the shift of the hysteresis loop towards the field direction opposite to the cooling-field direction. This exchange bias vanishes if the antiferromagnetic (AFM) layer thickness is below a certain value. However, for annealed bilayers with an MnPd layer thickness below a critical value, large exchange bias and asymmetric double-shifted loops are unexpectedly observed when the measuring field is along the cooling-field direction. These anomalies in the magnetization process can be explained if one postulates that the orientation of the AFM easy axis with respect to the spin direction of the ferromagnetic layer is changed when the thickness of the AFM layer decreases. r

Journal of Child Neurology, 2001

We describe a 5-year-old child with hypertrophic cardiomyopathy, mitochondrial myopathy, and lact... more We describe a 5-year-old child with hypertrophic cardiomyopathy, mitochondrial myopathy, and lactic acidosis. Mitochondrial DNA analysis showed a heteroplasmic A5814G point mutation in the tRNA(Cys) gene. The mutational load was extremely high (&amp;amp;amp;amp;amp;amp;amp;gt;95%) in muscle, fibroblasts, and blood. This report expands the clinical heterogeneity of the A5814G mutation, which should be considered in the differential diagnosis of hypertrophic cardiomyopathy in childhood.

Annals of Neurology, 1997

We identified large-scale heteroplasmic mitochondrial DNA (mtDNA) rearrangements in a 50–year-old... more We identified large-scale heteroplasmic mitochondrial DNA (mtDNA) rearrangements in a 50–year-old woman with an adult-onset progressive myopathy. The predominant mtDNA abnormality was a 21.2–kb duplicated molecule. In addition, a small population of the corresponding partially deleted 4.6–kb molecule was detected. Skeletal muscle histology revealed fibers that were negative for cytochrome c oxidase (COX) activity and had reduced mtDNA-encoded COX subunits. By single-fiber polymerase chain reaction analysis, COX-negative fibers contained a low number of wild-type or duplicated mtDNA molecules (ie, nondeleted). In situ hybridization demonstrated that the abnormal fibers contained increased amounts of mtDNA compared with normal fibers and that most of the genomes were deleted. We concluded that deleted mtDNA molecules were primarily responsible for the phenotype in this patient.

Muscle & Nerve, 2004

We report five patients with mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) who ha... more We report five patients with mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) who had demyelinating peripheral neuropathy. The MNGIE neuropathy had clinical and electrodiagnostic features typical of acquired, rather than inherited, etiologies. In fact, three patients were actually treated for chronic inflammatory demyelinating polyneuropathy (CIDP). We discuss findings that may help distinguish patients with MNGIE from those with CIDP. Muscle Nerve 29: 364–368, 2004

Chemical Physics Letters, 2006

We present a DFT study for the adsorption of single Pt atom and Pt clusters on graphene surface a... more We present a DFT study for the adsorption of single Pt atom and Pt clusters on graphene surface and carbon nanotube. Adsorption of a Pt atom shows a heavy dependence of binding energy on the graphene curvature. The adsorbed Pt atoms tend to form clusters, than to disperse on the graphene surface. The Pt-Pt bond length and the charge transfer from Pt clusters to the nanotube vary as a function of cluster size. A simulation of oxygen adsorption suggests higher performance for catalytic activities of Pt clusters adsorbed on the nanotube, in comparison with free Pt clusters.

Physical Review Letters, 1979

The composition of He metastable beams formed by charge exchange on alkali-metal vapors is determ... more The composition of He metastable beams formed by charge exchange on alkali-metal vapors is determined by a time-of-flight analysis. The relative abundance of the two components He(2 3 S) and He(2 1 S) is measured in the 100-1500-eV energy range. It is shown that a ...

Journal of Magnetism and Magnetic Materials, 2006

Exchange-biased CrMn/Co bilayers with various thicknesses of Co sputtered onto Si(1 0 0) substrat... more Exchange-biased CrMn/Co bilayers with various thicknesses of Co sputtered onto Si(1 0 0) substrates by the RF sputtering system have been studied. Double-shifted loops have been observed with the thickness of Co layer in a narrow range and become single-shifted loops after some cycles of measurement. Those results are interpreted as the association of positive and negative exchange bias. r

Journal of Physics: Conference Series, 2009

... magnetic fluid Pham Hoai Linh 1 , Nguyen Chi Thuan 1 , Nguyen Anh Tuan 1 , Pham Van Thach 1 ,... more ... magnetic fluid Pham Hoai Linh 1 , Nguyen Chi Thuan 1 , Nguyen Anh Tuan 1 , Pham Van Thach 1 , Tran Cong Yen 2 , Nguyen Thi Quy 2 , Hoang Thi My Nhung 2 , Phi Thi Xuyen 2 , Nguyen Xuan Phuc 1 and Le Van Hong 1 ...