http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Evaluation of Hardness and Fracture Toughness in a Porcelain Stoneware with Pseudoboehmite Additions
O. Aguilar-García,S. Bribiesca-Vazquez,J. Zárate-Medina 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.1
The effect of pseudoboehmite additions to conventional stoneware porcelain is investigated. Green compacts were formed by slip casting of stabilized aqueous suspensions and then sintering at 1,150℃, 1,200℃ and 1,250℃. The phase evolution was followed by XRD, the densification degree was calculated from densities and the microstructures were studied by SEM. Hardness, H and fracture toughness, KIC were measured by Vicker’s indentation. When vitrification occurs the presence of the pseudoboehmite leads to a extra mullitization, which has two consequences: a volume expansion resulting in a high porosity and a decrease of the amount of liquid which causes problems with the densification, by these facts the pseudoboehmite particles decrease the fracture toughness of the bodies. The effect of pseudoboehmite additions to conventional stoneware porcelain is investigated. Green compacts were formed by slip casting of stabilized aqueous suspensions and then sintering at 1,150℃, 1,200℃ and 1,250℃. The phase evolution was followed by XRD, the densification degree was calculated from densities and the microstructures were studied by SEM. Hardness, H and fracture toughness, KIC were measured by Vicker’s indentation. When vitrification occurs the presence of the pseudoboehmite leads to a extra mullitization, which has two consequences: a volume expansion resulting in a high porosity and a decrease of the amount of liquid which causes problems with the densification, by these facts the pseudoboehmite particles decrease the fracture toughness of the bodies.
Alejandre-Castañeda Viridiana,Patiño-Medina J. Alberto,Valle-Maldonado Marco I.,García Alexis,Ortiz-Alvarado Rafael,Ruíz-Herrera León F.,Castro-Cerritos Karla Viridiana,Ramírez-Emiliano Joel,Ramírez-D 한국미생물학회 2023 The journal of microbiology Vol.61 No.12
Mucormycosis is a lethal and difficult-to-treat fungal infection caused by fungi of the order Mucorales. Mucor lusitanicus, a member of Mucorales, is commonly used as a model to understand disease pathogenesis. However, transcriptional control of hyphal growth and virulence in Mucorales is poorly understood. This study aimed to investigate the role of Tec proteins, which belong to the TEA/ATTS transcription factor family, in the hyphal development and virulence of M. lusitanicus. Unlike in the genome of Ascomycetes and Basidiomycetes, which have a single Tec homologue, in the genome of Mucorales, two Tec homologues, Tec1 and Tec2, were found, except in that of Phycomyces blakesleeanus, with only one Tec homologue. tec1 and tec2 overexpression in M. lusitanicus increased mycelial growth, mitochondrial content and activity, expression of the rhizoferrin synthetase-encoding gene rfs, and virulence in nematodes and wax moth larvae but decreased cAMP levels and protein kinase A (PKA) activity. Furthermore, tec1- and tec2-overexpressing strains required adequate mitochondrial metabolism to promote the virulent phenotype. The heterotrimeric G beta subunit 1-encoding gene deletant strain (Δgpb1) increased cAMP-PKA activity, downregulation of both tec genes, decreased both virulence and hyphal development, but tec1 and tec2 overexpression restored these defects. Overexpression of allele-mutated variants of Tec1(S332A) and Tec2(S168A) in the putative phosphorylation sites for PKA increased both virulence and hyphal growth of Δgpb1. These findings suggest that Tec homologues promote mycelial development and virulence by enhancing mitochondrial metabolism and rhizoferrin accumulation, providing new information for the rational control of the virulent phenotype of M. lusitanicus.
Mixture design to optimize the amount of deflocculants in aqueous porcelain precursor suspensions
O. Aguilar-García,S. Bribiesca-Vazquez,J. Zárate-Medina 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.2
The performance of dispersants poly(acrylic acid), a poly(methacrylic acid), sodium silicate, as well as binary and ternary deflocculant mixtures was compared for highly concentrated aqueous porcelain suspensions. These were formulated in ten stoneware recipes which were processed in the laboratory under fixed conditions, similar to those used in the ceramics industry, and viscosity measurements were made. The use of this methodology enabled the calculation of valid regression models (equations) relating viscosity with the contents of different deflocculant mixtures. The performance of dispersants poly(acrylic acid), a poly(methacrylic acid), sodium silicate, as well as binary and ternary deflocculant mixtures was compared for highly concentrated aqueous porcelain suspensions. These were formulated in ten stoneware recipes which were processed in the laboratory under fixed conditions, similar to those used in the ceramics industry, and viscosity measurements were made. The use of this methodology enabled the calculation of valid regression models (equations) relating viscosity with the contents of different deflocculant mixtures.
AURKA Gene Variants rs1047972, and rs8173 Are Associated With Breast Cancer
Eric Jonathan Maciel-Cruz,Luis Eduardo Figuera-Villanueva,Asbiel Felipe Garibaldi-Ríos,Belinda Claudia Gómez-Meda,Guillermo Moisés Zúñiga-González,Ana María Pérez,Paola B Castro-García,Ramiro Ramírez- 한국유방암학회 2023 Journal of breast cancer Vol.26 No.4
Purpose: Association between variants rs1047972 and rs8173 of the AURKA gene in healthy women and breast cancer (BC) in a Mexican population. Methods: Genomic DNA samples from 409 healthy women and 572 patients with BC were analyzed for variants rs1047972 and rs8173 of the AURKA gene by polymerase chain reaction-restriction fragment length polymorphism. Results: TT genotype (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.22–5.11; p = 0.0015) and the T allele (OR, 1.16; 95% CI, 1.23–2.12; p = 0.0007) of the rs1047972 variant were associated as risk susceptibility for BC relative to the control group. Contrarily, the GG genotype (OR, 0.64; 95% CI, 0.43–0.94; p = 0.029) was associated as a protective factor of susceptibility of BC of the variant rs8173 of the AURKA gene. Differences were observed in the patients with BC who were carriers of the CT genotype of the rs1047972 variant with overweight, obesity, estrogen receptor-positive plus obesity, Ki-67 (≥ 20%) plus history familial positive of cancer; and for variant rs8173 the BC patients who were CG carriers and presented chemotherapy gastric toxicity, hormonal receptor positive plus chemotherapy gastric toxicity, and menopause status plus chemotherapy gastric toxicity (p < 0.05). Two common haplotypes were identified in the study groups: CG and TC genotypes, were associated as a protective and risk factor, respectively (p < 0.05). Conclusion: Variants rs1047972 and rs8173 of the AURKA gene and the TC haplotype were associated as risk susceptibility factors for BC in this population.
Wheat Bran Globulins: Competitive Inhibitors of Mushroom Tyrosinase
Angel Martín Ortíz-Estrada,Jorge Nemesio Mercado-Ruiz,Alma Rosa Islas-Rubio,Ana María Mendoza-Wilson,René Renato Balandrán-Quintana,Jesús Manuel García-Robles 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.3
The inhibitory capacity of the globulin fraction of wheat bran against the diphenolase activity of mushroom tyrosinase, using L-tyrosine as substrate, was evaluated. Enzyme kinetics was monitored in the presence of globulin solutions by measuring the absorbance at 475nm. Lineweaver-Burk plots were drawn in order to determine Vmax, Km, and type of inhibition. Results showed that globulins from wheat bran competitively inhibited, the activity of mushroom tyrosinase with a KI of 0.79%(w/v). The degree of inhibition was 24% at 2 mM of the substrate L-tyrosine.
Félix Téllez-Ávila,Josué Barahona-Garrido,Sandra García-Osogobio,Gustavo López-Arce,Jesús Camacho-Escobedo,Angela Saúl,Salvador Herrera-Gómez,Javier Elizondo-Rivera,Rafael Barreto-Zúñiga 대한소화기내시경학회 2014 Clinical Endoscopy Vol.47 No.1
Background/Aims: No clear data have been established and validated regarding whether rectal retroflexion has an important and therapeutic impact. The aim of the present study was to evaluate the diagnostic yield and therapeutic impact of rectal retroflexion compared with straight view examination. Methods: A prospective single-blind study was conducted. Consecutive patients evaluated between October 2011 and April 2012 were included. Results: A total of 934 patients (542 women [58%]) were included. The mean age was 57.4±14.8 years. Retroflexion was successful in 917 patients (98.2%). Distinct lesions in the anorectal area were detected in 32 patients (3.4%), of which 10 (1%) were identified only on retroflex view and 22 (2.4%) on both straight and retroflex views. Of the 32 identified lesions, 16 (50%) were polyps, nine (28.1%) were angiodysplasias, six (18.8%) were ulcers, and one (3.1%) was a flat lesion. All 10 patients (1%) in whom lesions were detected only by rectal retroflexion showed a therapeutic impact. Conclusions: Rectal retroflexion has minimal diagnostic yield and therapeutic impact. However, its low rate of major complications and the possibility of detecting lesions undetectable by straight viewing justify its use.
Antibacterial and Antifungal Activities of Some Mexican Medicinal Plants
E. Ruiz-Bustos,C. Velazquez,A. Garibay-Escobar,Z. García,M. Plascencia-Jatomea,M.O. Cortez-Rocha,J. Hernandez-Martínez,R.E. Robles-Zepeda 한국식품영양과학회 2009 Journal of medicinal food Vol.12 No.6
In Mexico about 4,000 plant species have some medicinal use. The aim of this work was to evaluate the antimicrobial activity of six Mexican medicinal plants against fungi and Gram-positive and Gram-negative bacteria. Methanolic extracts were prepared from the Mexican medicinal plants Amphypteringium adstrigens, Castella tortuosa, Coutarea latiflora, Ibervillea sonorae, Jatropha cuneata, and Selaginella lepidophylla. The antibacterial and antifungal activities of the plants were determined by the broth microdilution method and the radial growth inhibition assay, respectively. All Mexican plants tested showed antimicrobial activity. Among the six plant extracts analyzed, J. cuneata showed the highest growth-inhibitory activity against fungi, Gram-positive and Gram-negative bacteria (J. cuneata > A. adstrigens > C. latiflora > C. tortuosa > I. sonorae ≈ S. lepidophylla). Shigella flexneri and Staphylococcus aureus were the most susceptible bacteria to plant extracts. Complete inhibition of S. flexneri growth was observed with J. cuneata methanolic extract at 90μg/mL. This plant extract also showed the strongest antifungal activity against Fusarium verticillioides and Aspergillus niger. Our data suggest that the medicinal plants tested have important antimicrobial properties. This is the first report describing the antimicrobial activities of several of the Mexican medicinal plants used in this study.
Pressure Dependence of the Magneto-transport Properties in Fe/MgO Granular Systems
A. Garc´ıa-Garc´ıa,P. A. Algarabel,J. A. Pardo,Z. Arnold,J. Kamarad 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.10
The effect of hydrostatic pressure at room temperature on the resistance and magnetoresistance (MR) of a discontinuous metal-insulator multilayer (DMIM) of nominal composition [Fe(tFe = 0.7nm)/MgO(tMgO = 3 nm)]15 has been studied. The resistivity of the DMIM, ρ, decreases linearly with pressure indicating an increase in conduction via tunneling effect. The value of coefficient (1/ρ0)dρ/dP = –3.9 × 10−2 kbar−1 is higher than reported values in other granular films implying that the electronic state of the DMIM is close to the iron percolation threshold. At the maximum applied magnetic field (3 kOe) the MR ratio increases from 0.6% at ambient pressure to 1.1% at 7 kbar. This result can be explained by a reduction of the tunnel barrier width induced by the hydrostatic pressure.
Optical Properties of a Quantum Dot-Ring System Grown Using Droplet Epitaxy
Linares-Garcí,a, Gabriel,Meza-Montes, Lilia,Stinaff, Eric,Alsolamy, S. M.,Ware, M. E.,Mazur, Y. I.,Wang, Z. M.,Lee, Jihoon,Salamo, G. J. Springer US 2016 NANOSCALE RESEARCH LETTERS Vol.11 No.1
<P>Electronic and optical properties of InAs/GaAs nanostructures grown by the droplet epitaxy method are studied. Carrier states were determined by <B>k</B><B>·</B><B>p</B> theory including effects of strain and In gradient concentration for a model geometry. Wavefunctions are highly localized in the dots. Coulomb and exchange interactions are studied and we found the system is in the strong confinement regime. Microphotoluminescence spectra and lifetimes were calculated and compared with measurements performed on a set of quantum rings in a single sample. Some features of spectra are in good agreement.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s11671-016-1518-2) contains supplementary material, which is available to authorized users.</P>
The Delta Scuti star 38 Eri from the ground and from space
Paparó,, M,Kollá,th, Z,Shobbrook, R R,Matthews, J M,Antoci, V,Benkő,, J M,Park, N-K,Mirtorabi, M T,Luedeke, K,Kusakin, A,Bogná,r, Zs,Só,dor, Á,Garcí,a-Hern&aac Oxford University Press 2018 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.477 No.4