Inhomogeneous Ferromagnetism and Spin-Glass-Like Behavior in <inline-formula> <tex-math notation='TeX'> <tex> $({\rm Nd}_{1-x}{\rm Y}_{x})_{0.7}{\rm Sr}_{0.3}{\rm MnO}_{3}$ </tex> </tex-math></inline-formula> With <inline-formula> <tex-math notation='TeX

Phan, T. L.,Nguyen, V. D.,Ho, T. A.,Khiem, N. V.,Thanh, T. D.,Phuc, N. X.,Thang, P. D.,Yu, S. C. IEEE 2014 IEEE transactions on magnetics Vol.50 No.6

<P>The magnetic properties of polycrystalline ceramic samples (Nd1-xYx)(0.7)Sr0.3MnO3 with x = 0.21 - 0.35 were studied by means of dc magnetization and ac susceptibility measurements. Experimental results reveal a strong decrease of the ferromagnetic (FM)-paramagnetic phase-transition temperature (T-C) from 97 to 65 K as increasing x from 0.21 to 0.35, respectively. There is magnetic inhomogeneity associated with short-range FM order. Particularly, the samples undergo a spin-glass (SG) phase transition at the so-called blocking temperature (T-B) below T-C, which shifts toward lower temperatures with increasing the applied field, Hex; T-B -> T-g (the SG phase-transition temperature) as H-ex -> 0. The existence of the SG behavior in these samples was also confirmed by frequency (f) dependences of the ac susceptibility. For the in-phase/real component, chi' (T), it shows a frequency-dependent peak at the SG freezing temperature (T-f); T-f -> T-g as f -> 0. Dynamics of this process were analyzed by means of the slowing down scaling law, tau/tau(0) proportional to (T-f/T-g - 1)(-zv), where tau(0) and zv are the characteristic time and critical exponent, respectively. Fitting the experimental T-f(f) data to the scaling law gave the results of zv = 10.1-12.3 and tau(0) = 10(-21)-10(-15)s. These values are different from those expected for canonical SG systems with zv = 10 and tau(0) = 10(-13)s, revealing the cluster-SG behavior of (Nd1-xYx)(0.7)Sr0.3MnO3 samples. Notably, the increase in Y content leads to the shift of tau(0) and zv values toward those of canonical SG systems, which is ascribed to an expansion of SG clusters.</P>

Mixed-Metal Zeolitic Imidazolate Frameworks and their Selective Capture of Wet Carbon Dioxide over Methane

Nguyen, Nhung T. T.,Lo, Tien N. H.,Kim, Jaheon,Nguyen, Huong T. D.,Le, Toan B.,Cordova, Kyle E.,Furukawa, Hiroyasu American Chemical Society 2016 Inorganic Chemistry Vol.55 No.12

<P>A presynthesized, square planar copper imidazole complex, [Cu(imidazole)(4)](NO3)(2), was utilized as a precursor in the synthesis of a new series of zeolitic imidazolate frameworks, termed ZIF-202, -203, and -204. The structures of all three members were solved by single-crystal X-ray diffraction analysis, which revealed ZIF-203 and -204 having successfully integrated square planar units within the backbones of their respective frameworks. As a result of this unit, the structures of both ZIF-203 and -204 were found to adopt unprecedented three-dimensional nets, namely, ntn and thl, respectively. One member of this series, ZIF-204, was demonstrated to be highly porous, exhibit exceptional stability in water, and selectively capture CO2 over CH4 under both dry and wet conditions without any loss in performance over three cycles. Remarkably, the regeneration of ZIF-204 was performed under the mild conditions of flowing a pure N-2 gas through the material at ambient temperature.</P>

The reproduction potentials of four entomopathogenic nematode strains related to cost-effective production for biological control

Chau Nguyen N.,Anh Le T.,Vu Nguyen H.,Phuc Hoang K. 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.2

Bioassays to evaluate the mortality, virulence and reproduction potentials of four indigenous EPN strains, SPQ16, S-BM12, H-KT3987 and H-CB3452 on insect larvae of mealworm (Tenebrio molitor) and greater wax moth (Galleria mellonella) revealed the highest mortality rates of two insect larvae at the highest inoculation dose of 100 IJs to range from 89 to 100 percent and 94.3–100 percent at 48 h after inoculation, respectively. Virulence was high for all nematode strains, with LC 50 values between 29.6 and 47.3 IJs/insect host. The highest IJ yields were different between nematode strains and insect host, from 66.8 × 10 3 IJs (S-PQ16) to 118.6 × 10 3 IJs (HKT3987) on T. molitor, and from 54.2 × 10 3 IJs (S-BM12) to 163.3 × 10 3 IJs (H-KT3987) on G. mellonella. The culturing cost in terms of food expenditure for rearing insect larvae varied between insect larvae and nematode strains, from 6.76 to 26.63 USD per billion IJs for nematode strains cultured on T. molitor larvae and from 3.54 to 7.81 USD per billion IJs for nematode strains cultured on G. mellonella larvae. The full cost for a nematode product of 2.5 × 10 9 IJs per hectare, produced through in vivo mass culturing, of the most efficient nematode strain, H-KT3987, was 191.3 USD, slightly cheaper than 199.4 USD for the same nematode product produced through in vitro mass culturing.

Coronary Atherosclerosis T₁-Weighed Characterization With Integrated Anatomical Reference

Xie, Y.,Kim, Y.J.,Pang, J.,Kim, J.S.,Yang, Q.,Wei, J.,Nguyen, C.T.,Deng, Z.,Choi, B.W.,Fan, Z.,Bairey Merz, C.N.,Shah, P.K.,Berman, D.S.,Chang, H.J.,Li, D. Elsevier Science B.V. Amsterdam 2017 JACC CARDIOVASCULAR IMAGING Vol.10 No.6

Objectives: The aim of this work is the development of coronary atherosclerosis T<SUB>1</SUB>-weighted characterization with integrated anatomical reference (CATCH) technique and the validation by comparison with high-risk plaque features (HRPF) observed on intracoronary optical coherence tomography (OCT) and invasive coronary angiography. Background: T<SUB>1</SUB>-weighted cardiac magnetic resonance with or without contrast media has been used for characterizing coronary atherosclerosis showing promising prognostic value. Several limitations include: 1) coverage is limited to proximal coronary segments; 2) spatial resolution is low and often anisotropic; and 3) a separate magnetic resonance angiography acquisition is needed to localize lesions. Methods: CATCH acquired dark-blood T<SUB>1</SUB>-weighted images and bright-blood anatomical reference images in an interleaved fashion. Retrospective motion correction with 100% respiratory gating efficiency was achieved. Reference control subjects (n = 13) completed both pre- and post-contrast scans. Stable angina patients (n = 30) completed pre-contrast scans, among whom 26 eligible patients also completed post-contrast scans. After cardiac magnetic resonance, eligible patients (n = 22) underwent invasive coronary angiography and OCT for the interrogation of coronary atherosclerosis. OCT images were assessed and scored for HRPF (lipid-richness, macrophages, cholesterol crystals, and microvessels) by 2 experienced analysts blinded to magnetic resonance results. Results: Per-subject analysis showed none of the 13 reference control subjects had coronary hyperintensive plaques (CHIP) in either pre-contrast or post-contrast CATCH. Five patients had CHIP on pre-contrast CATCH and 5 patients had CHIP on post-contrast CATCH. Patients with CHIP had greater lipid abnormality than those without. Per-segment analysis showed elevated pre- and post-contrast plaque to myocardium signal ratio in the lesions with HRPF versus those without. Positive correlation was observed between plaque to myocardium signal ratio and OCT HRPF scoring. CHIP on pre-contrast CATCH were associated with significantly higher stenosis level than non-CHIP on invasive coronary angiography. Conclusions: CATCH provided accelerated whole heart coronary plaque characterization with simultaneously acquired anatomical reference. CHIP detected by CATCH showed positive association with high-risk plaque features on invasive imaging studies.

Steroid Components of Marine-Derived Fungal Strain Penicillium levitum N33.2 and Their Biological Activities

Chi K. Hoang,Cuong H. Le,Dat T. Nguyen,Hang T. N. Tran,Chinh V. Luu,Huong M. Le,Ha T. H. Tran 한국균학회 2023 Mycobiology Vol.51 No.4

Genus Penicillium comprising the most important and extensively studied fungi has beenwell-known as a rich source of secondary metabolites. Our study aimed to analyze andinvestigate biological activities, including in vitro anti-cancer, anti-inflammatory and anti-diabeticproperties, of metabolites from a marine-derived fungus belonging to P. levitum. Thechemical compounds in the culture broth of P. levitum strain N33.2 were extracted withethyl acetate. Followingly, chemical analysis of the extract leaded to the isolation of threeergostane-type steroid components, namely cerevisterol (1), ergosterol peroxide (2), and(3b,5a,22E)-ergosta-6,8(14),22-triene-3,5-diol (3). Among these, (3) was the most potent cytotoxicagainst human cancer cell lines Hep-G2, A549 and MCF-7 with IC50 values of 2.89,18.51, and 16.47 mg/mL, respectively, while the compound (1) showed no significant effectagainst tested cancer cells. Anti-inflammatory properties of purified compounds were evaluatedbased on NO-production in LPS-induced murine RAW264.7 macrophages. As a result,tested compounds performed diverse inhibitory effects on NO production by the macrophages,with the most significant inhibition rate of 81.37 ± 1.35% at 25 mg/mL by the compound(2). Interestingly, compounds (2) and (3) exhibited inhibitory activities againstpancreatic lipase and a-glucosidase enzymes in vitro assays. Our study brought out newdata concerning the chemical properties and biological activities of isolated steroids from aP. levitum fungus.

Traumatic brain injury-induced hypo-O-GlcNAcylation contributes to cognitive dysfunction in adult zebrafish

Ngan An Bui,Dong Yeol Kim,Jiwon Park,Sang-Min Kim,Hyun Jae Sung,Thuy-Duong ThiTran,Quynh T N Nguyen,Inn-Oc Han 한국당과학회 2022 한국당과학회 학술대회 Vol.2022 No.07

Traumatic brain injury (TBI) is known as a functional corruption of the brain caused by a bump or blast to the head when an object hits suddenly or pierces the skull and penetrates brain tissues. There is an urgent need of understanding the pathophysiology following TBI because the morbidity and mortality rates worldwide caused by TBI have remained high throughout decades. In this study, we used a novel model of adult zebrafish to study the molecular and physiological changes following TBI. Using T-maze, on the 3rd-day post-stab-lesion injury (dpi), learning and memory deficits and poor social response were observed. Results from mirror biting and novel tank tests also provided us insight into their defective mobility, explorational, and territorial instincts. Neurogenesis impairment and severe brain inflammation were also altered following TBI, especially at 3 dpi. Upon injury, a notable decrease of O-GlcNAc level was remarked at 3dpi. Deregulation of O-GlcNAcylation which led to impaired glucose metabolism was informed to contribute to the pathologies of neurodegenerative diseases. Glucosamine (GlcN), a natural compound found in cartilage, is known as a derivative of the pathway that can increase O-GlcNAcylation by bypassing the reaction catalyzed by a rate liming enzyme GFAT. To further investigate the correlation, after TBI exposure, zebrafish had been recovered 3 days in 0.1g/L glucosamine (GlcN) diluted in water. Under the treatment of GlcN, the inflammation level reduced significantly, indicated by the decrease of Nuclear factor-kappa B and Glial fibrillary acidic protein expression in the telencephalon. TBI-induced downregulation of the cAMP signaling pathway and its relevant proteins in synaptic plasticity were rescued by GlcN. O-GlcNAc deficiency observed previously, as well as L/M capability were retrieved. GlcN also elevated the number of new cells regenerations and neuronal differentiation. As a result, regulation of brain O-GlcNAcylation may hold a potential role in TBI’s recuperation.

Sorting CD4+ T Cells in Blood by Using Magnetic Nanoparticles Coated with Anti-CD4 Antibody

N. T. Khuat,V. T. A. Nguyen,T. N. Phan,L. H. Hoang,C. V. Thach,N. H. Hai,N. Chau 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.6

We used Fe3O4 magnetic nanoparticles (MNPs) which are coated with antiCD4 monoclonal antibody to bind selectively onto membranes of CD4+ T cells (hereafter antiCD4-MNPs). The antiCD4-MNPs were prepared through direct covalent interaction between the carboxyl group of the antiCD4 antibody and the amino group of amino-modified MNPs. The antiCD4-MNPs were mixed with human blood cells, followed by bursting the red blood cells with hypotonic buffer; then, the antiCD4-MNPs coated cells were separated by using a magnet. We observed the number of cells bound with magnetite clusters and particles. When fluorescence isothiocyanate labeled antiCD4- MNPs was used to observe the CD4+ T cells, the fluorescent intensity was improved by about two times compared to that when cells were labeled with the antiCD4 antibody only. This is a potential method to sort helper CD4+ T cells for observation under conventional microscopes. We used Fe3O4 magnetic nanoparticles (MNPs) which are coated with antiCD4 monoclonal antibody to bind selectively onto membranes of CD4+ T cells (hereafter antiCD4-MNPs). The antiCD4-MNPs were prepared through direct covalent interaction between the carboxyl group of the antiCD4 antibody and the amino group of amino-modified MNPs. The antiCD4-MNPs were mixed with human blood cells, followed by bursting the red blood cells with hypotonic buffer; then, the antiCD4-MNPs coated cells were separated by using a magnet. We observed the number of cells bound with magnetite clusters and particles. When fluorescence isothiocyanate labeled antiCD4- MNPs was used to observe the CD4+ T cells, the fluorescent intensity was improved by about two times compared to that when cells were labeled with the antiCD4 antibody only. This is a potential method to sort helper CD4+ T cells for observation under conventional microscopes.

Antiviral phenolics from the leaves of Cleistocalyx operculatus

Ha, T.K.Q.,Dao, T.T.,Nguyen, N.H.,Kim, J.,Kim, E.,Cho, T.Oh.,Oh, W.K. Elsevier 2016 Fitoterapia Vol.110 No.-

<P>During the screening program for anti-influenza agents from medicinal plants, the ethanolic extract of Cleistocalyx operculatus leaves was found to exhibit potential neuraminidase (NA) inhibitory activity. Bioassay directed fractionation led to the isolation of two new acetophenones (1 and 2) and one new flavanone (3), along with six known compounds (4-9). The structures of all isolated compounds were elucidated using various spectroscopic methods and through comparison with the previous literature. Compounds 6 and 8 exhibited strong enzymatic inhibition on various neuraminidases from different influenza viruses, including H1N1, H9N2, novel H1N1, and oseltamivir-resistant novel H1N1 (H274Y mutation) expressed in HEM293 cells (IC50 values ranging from 5.07 +/- 0.94 mu M to 9.34 +/- 2.52 mu M, respectively). Kinetic experiments revealed the non-competitive inhibitory mode of both compounds 6 and 8. Furthermore, these flavonoids reduced the cytopathic effect of the H1N1 virus in MDCK cells. The present study suggests the potential of two flavonoids (6 and 8) as new lead compounds for the development of novel NA inhibitors in the future. (C) 2016 Elsevier B.V. All rights reserved.</P>

Sorting CD4⁺ T Cells in Blood by Magnetic Nanoparticles Coated with Anti-CD4 Antibody

N.T. Khuat,V.A.T. Nguyen,T.N. Phan,C.V. Thach,N.H. Hai,N.H. Luong,N. Chau 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

The K\"{a}hler Different of a Set of Points in~$\pmpn$

Nguyen T. Hoa,Tran N. K. Linh,Le N. Long,Phan T. T. Nhan,Nguyen T. P. Nhi 대한수학회 2022 대한수학회보 Vol.59 No.4

Given an ACM set $\X$ of points in a multiprojective space $\pmpn$ over a field of characteristic zero, we are interested in studying the K\"ahler different and the Cayley-Bacharach property for $\X$. In $\bbP^1\times \bbP^1$, the Cayley-Bacharach property agrees with the complete intersection property and it is characterized by using the K\"ahler different. However, this result fails to hold in $\pmpn$ for $n>1$ or $m>1$. In this paper we start an investigation of the K\"ahler different and its Hilbert function and then prove that $\X$ is a complete intersection of type $(d_1,\ldots,d_m,d'_1,\ldots,d'_n)$ if and only if it has the Cayley-Bacharach property and the K\"ahler different is non-zero at a certain degree. We characterize the Cayley-Bacharach property of $\X$ under certain assumptions.