Inactivating effect of phenolic unit structures on the biodegradation of lignin by lignin peroxidase from Phanerochaete chrysosporium

Thanh Mai Pham, L.,Eom, M.H.,Kim, Y.H. IPC Science and Technology Press ; Elsevier Scienc 2014 Enzyme and microbial technology Vol.61 No.-

An imbalance of electron in an intramolecular electron transfer pathway was identified as the central factor causing inefficient degradation of lignin by the lignin peroxidase H8 from Phanerochaete chrysosporium (LiPH8). It was elucidated that dimeric lignins or monolignolic analogs containing free-hydroxyl phenolic groups were not only favorable substrates for the reduction of LiPH8 but also strong inhibitors depressing the enzymatic degradation of lignin. The data collectively demonstrated that disturbing the interaction between the free ?OH group on the phenolic structure and the surface active sites around Trp171 caused the primary deficiency in electron transport between Trp171 and the heme site, which severely inhibited the efficiency of lignin biodegradation by LiPH8/H<SUB>2</SUB>O<SUB>2</SUB>.

ProverPSL : A Theorem Prover for Full Separation Logic

Mai H. Dinh,Sungwoo Park 한국정보과학회 2015 한국정보과학회 학술발표논문집 Vol.2015 No.12

Terahertz spin-orbital excitations in the paramagnetic state of multiferroicSr2FeSi2O7

Mai, Thuc T.,Svoboda, C.,Warren, M. T.,Jang, T.-H.,Brangham, J.,Jeong, Y. H.,Cheong, S.-W.,Valdé,s Aguilar, R. American Physical Society 2016 Physical Review B Vol.94 No.22

<P>We studied the novel multiferroic material Sr2FeSi2O7 and found three absorption modes above the magnetic ordering transition temperature using time-domain terahertz spectroscopy. These absorption modes can be explained as the optical transitions between the spin-orbit coupling and crystal-field split 3d(6) Fe2+ ground-state term in this material. Consideration of the compressed tetrahedral environment of the Fe2+ site is crucial to understand the excitations. We point out, however, discrepancies between the single-site atomic picture and the experimental results.</P>

Fit of interim crowns fabricated using photopolymer-jetting 3D printing

Mai, H.N.,Lee, K.B.,Lee, D.H. C. V. Mosby Co 2017 The Journal of prosthetic dentistry Vol.118 No.2

Statement of problem: The fit of interim crowns fabricated using 3-dimensional (3D) printing is unknown. Purpose: The purpose of this in vitro study was to evaluate the fit of interim crowns fabricated using photopolymer-jetting 3D printing and to compare it with that of milling and compression molding methods. Material and methods: Twelve study models were fabricated by making an impression of a metal master model of the mandibular first molar. On each study model, interim crowns (N=36) were fabricated using compression molding (molding group, n=12), milling (milling group, n=12), and 3D polymer-jetting methods. The crowns were prepared as follows: molding group, overimpression technique; milling group, a 5-axis dental milling machine; and polymer-jetting group using a 3D printer. The fit of interim crowns was evaluated in the proximal, marginal, internal axial, and internal occlusal regions by using the image-superimposition and silicone-replica techniques. The Mann-Whitney U test and Kruskal-Wallis tests were used to compare the results among groups (α=.05). Results: Compared with the molding group, the milling and polymer-jetting groups showed more accurate results in the proximal and marginal regions (P<.001). In the axial regions, even though the mean discrepancy was smallest in the molding group, the data showed large deviations. In the occlusal region, the polymer-jetting group was the most accurate, and compared with the other groups, the milling group showed larger internal discrepancies (P<.001). Conclusions: Polymer-jet 3D printing significantly enhanced the fit of interim crowns, particularly in the occlusal region.

골 결함 회복을 위한 Ti-Ta-Mo-Zr 합금의 two-step 표면 처리의 효과

Phuong Mai H.Nguyen,Ruizhi Yin,Shuang Wu,Yong-Seok Jang,Min-Ho Lee,Tae-Sung Bae 대한치과재료학회 2017 대한치과기재학회 학술대회 Vol.2017 No.11

The effect of two-step surface modification for Ti-Ta-Mo-Zr alloys on bone regeneration: An evaluation using calvarial defect on rat model

Nguyen, Phuong Mai H.,Won, Dae-Hee,Kim, Byung-Sam,Jang, Yong-Seok,Nguyen, Thuy-Duong T.,Lee, Min-Ho,Bae, Tae-Sung Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.442 No.-

<P><B>Abstract</B></P> <P>This study was conducted to explore the optimal anodization conditions and to evaluate the bioactivity of the coated-CaP TiO<SUB>2</SUB> nanotube layer on new Ti-Ta-Mo-Zr alloys. The nanotube was fabricated by anodization process, then anodized samples were treated with cyclic precalcification. Critical agents for nanotube morphology are anodizing voltage, time, and electrolyte compositions. The surface features were analyzed by field emission scanning electron microscopy equipped with an energy-dispersive X-ray spectrometer; X-ray diffractometer and surface roughness tester. The results showed clearer morphology and higher density of the nanotube structure on the surface of 71Ti-20Ta-1Mo-8Zr alloy than that of other alloys. The presence of precursors of hydroxyapatite (TCP, OCP) on the precalcified surface of this alloy inclined a high potential of hydroxyapatite formation. For in vivo test, membranes treated with either anodization (AH) or precalcification-combined anodization (APH) were covered on rat calvarial defects (8 mm of diameter) for 5 weeks, and untreated membranes were used as the control. The newly formed bone was evaluated by microcomputed tomography, histologic and fluorescent analysis. The newly formed bone on the APH membrane showed higher bone mineral density and a contact osseointegration, indicating that the APH treatment promotes durable osteogenesis at the early stage of bone defect repair.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The nanotube structure was formed on 71Ti-20Ta-1Mo-8Zr alloy by anodization. </LI> <LI> When the anodization parameters were changed, the nanotube properties were altered. </LI> <LI> Bioactive calcium-phosphate coated nanotube layer was created by precalcification. </LI> <LI> The bioactive coating promoted stable osteogenesis at the early bone defect healing. </LI> </UL> </P>

Soft x-ray absorption spectroscopy study of Mo-rich SrMn1−xMoxO3(x⩾0.5)

Hwang, J. H.,Kim, D. H.,Kang, J.-S.,Kolesnik, S.,Chmaissem, O.,Mais, J.,Dabrowski, B.,Baik, J.,Shin, H. J.,Lee, Jieun,Kim, Bongjae,Min, B. I. American Physical Society 2011 Physical review. B, Condensed matter and materials Vol.83 No.7

Magnetic properties and magnetocaloric effect in Fe90-x Sn x Zr10 alloy ribbons

Phan, T. L.,Dan, N. H.,Thanh, T. D.,Mai, N. T.,Ho, T. A.,Yu, S. C.,Le, Anh-Tuan,Phan, M. H. Korean Physical Society 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.8

<P>This work points out the possibility of tuning the magnetocaloric (MC) effect in Fe90-x Sn (x) Zr-10 alloy ribbons in the temperature range from 235 to 315 K by changing the Sn-doping content (x). Under an applied field change from 0 to 50 kOe, the maximum magnetic-entropy changes around the ferromagnetic-paramagnetic phase transition are about 3.6, 4.1 and 3.3 J kg(-1)center dot K-1 for x = 0, 2 and 4, respectively, which correspond to relative cooling powers of 280 similar to 410 J center dot kg(-1). Studying the magnetic properties of the alloy ribbons based on Banerjee's criteria and assessing the magneticordering parameter n = dLn|Delta S (m) |/dLnH (where Delta S (m) and H are the magnetic-entropy change and the magnetic field, respectively) reveals that the alloys undergo a second-order phase transition and exhibit a short-range ferromagnetic order. The nature of these phenomena is further analyzed by means of the results obtained from the analyses of the crystal structure, the Curie-Weiss law, and the Griffith phase.</P>

Molecular characterization of serotype A foot-and-mouth disease viruses circulating in Vietnam in 2009

Le, V.P.,Nguyen, T.,Lee, K.N.,Ko, Y.J.,Lee, H.S.,Nguyen, V.C.,Mai, T.D.,Do, T.H.,Kim, S.M.,Cho, I.S.,Park, J.H. Elsevier Scientific Pub. Co 2010 Veterinary microbiology Vol.144 No.1

Foot-and-mouth disease (FMD) is a major cause of endemic outbreaks in Vietnam in recent years. In this work, six serotype A foot-and-mouth disease viruses (FMDV), collected from endemic outbreaks during January and February of 2009 in four different provinces in Vietnam, were genetically characterized for their complete genome sequences. Genetic analysis based on the complete viral genome sequence indicated that they were closely related to each other and shared 99.0-99.8% amino acid (aa) identity. Genetic and deduced aa analysis of the capsid coding gene VP1 showed that the six Vietnamese strains were all classified into the genotype IX from a total of 10 major genotypes worldwide, sharing 98.1-100% aa identity each other. They were most closely related to the type A strains recently isolated in Laos (A/LAO/36/2003, A/LAO/½006, A/LAO/6/2006, A/LAO/7/2006, and A/LAO/8/2006), Thailand (A/TAI/2/1997 and A/TAI/118/1987), and Malaysia (A/MAY/2/2002), sharing 88.3-95.5% nucleotide (nt) identities. In contrast, Vietnamese type A strains showed low nt identities with the two old type A FMDVs, isolated in 1960 in Thailand (a15thailand iso43) and in 1975 in the Philippines (aphilippines iso50), ranging from 77.3 to 80.9% nt identity. A multiple alignment based on the deduced amino acid sequences of the capsid VP1 coding gene of type A FMDV revealed three amino acid substitutions between Vietnamese strains and the strains of other Southeast Asian countries (Laos, Thailand, Malaysia, and the Philippines). Alanine was replaced by valine at residue 24, asparagine by arginine at residue 85, and serine by threonine at residue 196. Furthermore, type A FMDV strains recently isolated in Vietnam, Laos, Thailand, and Malaysia all have one amino acid deletion at residue 140 of the capsid VP1 protein compared with the two old type A FMDV strains from Thailand and the Philippines as well as most other type A representatives worldwide. This article is the first to report on the comprehensive genetic characterization of type A FMDV circulating in Vietnam.

Direct typing and molecular evolutionary analysis of field samples of foot-and-mouth disease virus collected in Viet Nam between 2006 and 2007

Lee, K.N.,Nguyen, T.,Kim, S.M.,Park, J.H.,Do, H.T.,Ngo, H.T.,Mai, D.T.,Lee, S.Y.,Nguyen, C.V.,Yoon, S.H.,Kweon, C.H.,Cho, I.S.,Kim, H. Elsevier Scientific Pub. Co 2011 Veterinary microbiology Vol.147 No.3

In this study, we used universal or duplex serotype-specific (O and Asia 1) RT-PCR to analyze clinical field samples of foot-and-mouth disease virus (FMDV) or virus isolates collected in Viet Nam between 2006 and 2007. We found viral serotypes O and Asia 1 circulating concurrently during this period. Direct sequencing of type-specific RT-PCR products revealed the existence of three different topotypes of serotype O: Southeast Asia (SEA), Middle East-South Asia (ME-SA), and Cathay. Of these, SEA was most prevalent during the period. All samples of serotype Asia 1 belonged to genetic group V. Based on the rooted maximum likelihood phylogenetic trees inferred from the VP1 region, new lineages in topotype SEA were originating from Viet Nam, and group V strains of Asia 1 have undergone fewer passages from the common ancestor, compared with other genetic groups. The co-circulation of different types of FMDV may complicate the individual or population genomic structures of FMDV and make conventional multiplex diagnostic methods and phylogenetic analyses with relevant evolutionary models essential in Viet Nam.