Lentinula edodes (Shiitake) Modulates Chemically Induced Mutagenesis by Enhancing Pitting

Patrı´cia L. Alves de Lima,Marina M. Sugui,Angela I.M. Petrı´cio,Lı´zia C. Vilela,Andre´a V.F. Pinto,Priscila R. Martins,Ramon Kaneno,Daniel A. Ribeiro,Daisy M.F. Salvadori,Lu´cia R. Ribeiro 한국식품영양과학회 2013 Journal of medicinal food Vol.16 No.8

This study was undertaken to understand how Lentinula edodes modulates in vivo mutagenesis induced by alkylating agents in bone marrow and peripheral blood as described in our previous article. Male Swiss mice were pretreated for 15 consecutive days with aqueous extracts prepared from L. edodes, after which, the number of circulating blood cells, normal erythroid bone marrow cell cycling, and phagocytosis of micronucleated reticulocyte (MNRET) and activation of spleen macrophages were assessed. The results indicate that the antimutagenicity seen in bone marrow and peripheral blood is exerted by distinct compounds with different actions. The antimutagenic effect in bone marrow is exerted by compounds subject to degradation at deep-freeze storage temperature of - 20 C. On the other hand, compounds responsible for antimutagenicity in peripheral blood are not subject to degradation at - 20 C. The results also indicate that the antimutagenic action in peripheral blood leading to the reduction of circulating MNRET occurs in the spleen primarily through a phagocytic activity due to higher macrophage numbers and probably not due to the enhanced activation state of individual cells.

Adsorption studies of methylene blue onto ZnCl2-activated carbon produced from buriti shells (Mauritia flexuosa L.)

Osvaldo Pezoti Jr,Andre´ L. Cazetta,Isis P.A.F. Souza,Karen C. Bedin,Alessandro C. Martins,Tais L. Silva,Vitor C. Almeida 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

The present study reports the preparation of an activated carbon produced from buriti shells (ACb) usingZnCl2 as activating agent and its ability to removemethylene blue dye (MB) from aqueous solutions. Theobtained ACb was characterized by N2 adsorption–desorption isotherms, SEM and FT-IR. The resultsshow that ACb presents microporous features with BET surface area (SBET) of 843 m2 g-1 and functionalgroups common in carbonaceous materials. Adsorption studies were carried out and experimental datawere fitted to three isotherm models (Langmuir, Freundlich, and Redlich–Peterson) and four kineticmodels (pseudo-first order, pseudo-second order, Elovich, and intraparticle diffusion). The isothermmodel which best fitted to experimental data was Redlich–Peterson. However, the g parameter of thismodel indicated that the adsorption of MB onto ACb occurs according to the mechanism proposed byLangmuir, which showed maximum monolayer adsorption capacity of 274.62 mg g-1. Kinetic studiesdemonstrated that the Elovich model is suitable to describe the experimental data. Moreover, it wasfound that the intraparticle diffusion is the limiting step of adsorption process.

Molecular Imaging of CXCL12 Promoter-driven HSV1-TK Reporter Gene Expression

Lina Alon,Dara L. Kraitchman,Michael Schär,Angel Cortez,Nirbhay N. Yadav,Rebecca Krimins,Peter V. Johnston,Michael T. McMahon,Peter C. M. van Zijl,Sridhar Nimmagadda,Martin G. Pomper,Jeff W. M. Bulte 한국생물공학회 2018 Biotechnology and Bioprocess Engineering Vol.23 No.2

The C-X-C motif chemokine 12 (CXCL12, SDF1a) and its receptor, CXCR4, play a fundamental role in several biological processes, including hematopoiesis, cardiogenesis, cancer progression, and stem cell migration. Noninvasive monitoring of CXCL12 is highly desirable for optimizing strategies that combine mobilization of therapeutic cells to combat cancer or to assist in cardiac tissue repair after myocardial infarction. Here, we report on an MRI reporter gene system for directly monitoring CXCL12 expression in vivo. Glioma cells and human adipose-derived stem cells (hADSC) were transduced with the herpes simplex virus type-1-thymidine kinase (HSV1- tk) reporter gene expressed under the CXCL12 promoter. HSV1-tk expression resulted in accumulation of the PET tracer [125I]FIAU in vitro and in vivo and induced cell death after ganciclovir treatment. Furthermore, the results show that conditional expression of the reporter gene can be induced by hypoxia in transduced cells. Transduced hADSC were incubated with the CEST MRI probe 5-methyl-5, 6- dihydrothymidine (5-MDHT) and transplanted into swine heart. Transplanted cells were clearly visible on Chemical Exchange Saturation Transfer (CEST) MRI using a 3T clinical scanner. Therefore, we conclude that it is possible to image CXCL12 expression with MRI in a large animal model, opening up a possible route to clinical translation.

Influence of the Target Molecule on the Oxygen Radical Absorbance Capacity Index: A Comparison Between Alizarin Red- and Fluorescein-Based Methodologies

I. Martin,A. Aspée,P. Torres,E. Lissi,C. López-Alarcón 한국식품영양과학회 2009 Journal of medicinal food Vol.12 No.6

A comparison of alizarin red (AR) and fluorescein (FL) as target molecules in oxygen radical absorbance capacity (ORAC)-like methods is reported. Galangin, apigenin, ferulic acid, and coumaric acid decreased AR initial consumption rate, whereas quercetin, kaempferol, luteolin, caffeic acid, and sinapic acid inhibited its consumption through an induction time, associated with a repair mechanism. On the other hand, all compounds protected FL with a clear induction time. AR was more selective and provides ORAC-AR values considerably smaller for compounds of low reactivity. The ORAC-AR value for luteolin was nearly 200 times that of coumaric acid. However, the ratio of ORAC-FL values for luteolin and coumaric acid was only 1.2. This different selectivity implies that AR provides ORAC values more related to reactivity than FL. ORAC-AR values of infusions were considerably smaller than the corresponding ORAC-FL values. These differences are interpreted in terms of the capacity of FL to generate induction times, irrespective of the reactivity of the additive. It is proposed that comparison of ORAC-AR and ORAC-FL values could afford a rough estimation of the average reactivity of the antioxidants titrated by the ORAC-FL methodology.

Computer modeling and analytical prediction of shear transfer in reinforced concrete structures

Marcela N. Kataoka,Ana Lúcia H.C. El Debs,Daniel de L. Araújo,Bárbara G. Martins 사단법인 한국계산역학회 2020 Computers and Concrete, An International Journal Vol.26 No.2

This paper presents an evaluation of shear transfer across cracks in reinforced concrete through finite element modelling (FEM) and analytical predictions. The aggregate interlock is one of the mechanisms responsible for the shear transfer between two slip surfaces of a crack; the others are the dowel action, when the reinforcement contributes resisting a parcel of shear displacement (reinforcement), and the uncracked concrete comprised by the shear resistance until the development of the first crack. The aim of this study deals with the development of a 3D numerical model, which describes the behavior of Z-type push-off specimen, in order to determine the properties of interface subjected to direct shear in terms cohesion and friction angle. The numerical model was validated based on experimental data and a parametric study was performed with the variation of the concrete strength. The numerical results were compared with analytical predictions and a new equation was proposed to predict the maximum shear stress in cracked concrete.

Rapid growth of organic aerosol nanoparticles over a wide tropospheric temperature range

Stolzenburg, Dominik,Fischer, Lukas,Vogel, Alexander L.,Heinritzi, Martin,Schervish, Meredith,Simon, Mario,Wagner, Andrea C.,Dada, Lubna,Ahonen, Lauri R.,Amorim, Antonio,Baccarini, Andrea,Bauer, Paulu National Academy of Sciences 2018 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.115 No.37

<▼1><P><B>Significance</B></P><P>Aerosol particles can form and grow by gas-to-particle conversion and eventually act as seeds for cloud droplets, influencing global climate. Volatile organic compounds emitted from plants are oxidized in the atmosphere, and the resulting products drive particle growth. We measure particle growth by oxidized biogenic vapors with a well-controlled laboratory setup over a wide range of tropospheric temperatures. While higher temperatures lead to increased reaction rates and concentrations of highly oxidized molecules, lower temperatures allow additional, but less oxidized, species to condense. We measure rapid growth over the full temperature range of our study, indicating that organics play an important role in aerosol growth throughout the troposphere. Our finding will help to sharpen the predictions of global aerosol models.</P></▼1><▼2><P>Nucleation and growth of aerosol particles from atmospheric vapors constitutes a major source of global cloud condensation nuclei (CCN). The fraction of newly formed particles that reaches CCN sizes is highly sensitive to particle growth rates, especially for particle sizes [FORMULA OMISSION]10 nm, where coagulation losses to larger aerosol particles are greatest. Recent results show that some oxidation products from biogenic volatile organic compounds are major contributors to particle formation and initial growth. However, whether oxidized organics contribute to particle growth over the broad span of tropospheric temperatures remains an open question, and quantitative mass balance for organic growth has yet to be demonstrated at any temperature. Here, in experiments performed under atmospheric conditions in the Cosmics Leaving Outdoor Droplets (CLOUD) chamber at the European Organization for Nuclear Research (CERN), we show that rapid growth of organic particles occurs over the range from [FORMULA OMISSION]C to [FORMULA OMISSION]C. The lower extent of autoxidation at reduced temperatures is compensated by the decreased volatility of all oxidized molecules. This is confirmed by particle-phase composition measurements, showing enhanced uptake of relatively less oxygenated products at cold temperatures. We can reproduce the measured growth rates using an aerosol growth model based entirely on the experimentally measured gas-phase spectra of oxidized organic molecules obtained from two complementary mass spectrometers. We show that the growth rates are sensitive to particle curvature, explaining widespread atmospheric observations that particle growth rates increase in the single-digit-nanometer size range. Our results demonstrate that organic vapors can contribute to particle growth over a wide range of tropospheric temperatures from molecular cluster sizes onward.</P></▼2>

THE 2014 ALMA LONG BASELINE CAMPAIGN: OBSERVATIONS OF THE STRONGLY LENSED SUBMILLIMETER GALAXY HATLAS J090311.6+003906 AT <i>z</i> = 3.042

Vlahakis, C.,Hunter, T. R.,Hodge, J. A.,Pé,rez, L. M.,Andreani, P.,Brogan, C. L.,Cox, P.,Martin, S.,Zwaan, M.,Matsushita, S.,Dent, W. R. F.,Impellizzeri, C. M. V.,Fomalont, E. B.,Asaki, Y.,Barka IOP Publishing 2015 ASTROPHYSICAL JOURNAL LETTERS - Vol.808 No.1

<P>We present initial results of very high resolution Atacama Large Millimeter/submillimeter Array (ALMA) observations of the z = 3.042 gravitationally lensed submillimeter galaxy HATLAS J090311.6+003906 (SDP. 81). These observations were carried out using a very extended configuration as part of Science Verification for the 2014 ALMA Long Baseline Campaign, with baselines of up to similar to 15 km. We present continuum imaging at 151, 236, and 290 GHz at unprecedented angular resolutions as fine as 23 mas, corresponding to an unmagnified spatial scale of similar to 180 pc at z = 3.042. The ALMA images clearly show two main gravitational arc components of an Einstein ring, with emission tracing a radius of similar to 1 ''.5. We also present imaging of CO J = 10 - 9, J = 8 - 7, and J = 5 - 4 and H2O (202-111) line emission. The CO emission, at an angular resolution of similar to 170 mas, is found to broadly trace the gravitational arc structures but with differing morphologies between the CO transitions and compared to the dust continuum. Our detection of H2O line emission, using only the shortest baselines, provides the most resolved detection to date of thermal H2O emission in an extragalactic source. The ALMA continuum and spectral line fluxes are consistent with previous Plateau de Bure Interferometer and Submillimeter Array observations despite the impressive increase in angular resolution. Finally, we detect weak unresolved continuum emission from a position that is spatially coincident with the center of the lens, with a spectral index that is consistent with emission from the core of the foreground lensing galaxy.</P>

Modelling of the Electrochemical Performance of Functionally Graded Fuel Cell Electrodes by Discrete Simulations

Schneider L.C.R.,Martin C.L.,Bultel Y.,Kapelski G.,Bouvard D. 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

Solid Oxide Fuel Cell technology uses powder processes to produce electrodes with residual porosity by partially sintering a mixture of electronically and ionically conducting particles. We model porous fuel cell electrodes with 3D packings of monosized spherical particles. These packings are created by numerical sintering. Each particle-particle contact is characteristic for an ionic, electronic or electrochemical resistance. The numerical packing is then discretized into a resistor network which is solved by using Kirchhoff's current law to evaluate the electrode's electrochemical performance. We investigate in particular percolation effects in functionally graded electrodes as compared to other types of electrodes.

A fourth order finite difference method applied to elastodynamics: Finite element and boundary element formulations

L. A. Souza,J. A. M. Carrer,C. J. Martins 국제구조공학회 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.17 No.6

Status of paratyphoid fever vaccine research and development

Martin, L.B.,Simon, R.,MacLennan, C.A.,Tennant, S.M.,Sahastrabuddhe, S.,Khan, M.I. Butterworths ; Elsevier Science Ltd 2016 Vaccine Vol.34 No.26

Salmonella enterica serovars Typhi and Paratyphi (S. Paratyphi) A and B cause enteric fever in humans. Of the paratyphoid group, S. Paratyphi A is the most common serovar. In 2000, there were an estimated 5.4 million cases of S. Paratyphi A worldwide. More recently paratyphoid fever has accounted for an increasing fraction of all cases of enteric fever. Although vaccines for typhoid fever have been developed and in use for decades, vaccines for paratyphoid fever have not yet been licensed. Several S. Paratyphi A vaccines, however, are in development and based on either whole cell live-attenuated strains or repeating units of the lipopolysaccharide O-antigen (O:2) conjugated to different protein carriers. An O-specific polysaccharide (O:2) of S. Paratyphi A conjugated to tetanus toxoid (O:2-TT), for example, has been determined to be safe and immunogenic after one dose in Phase I and Phase II trials. Two other conjugated vaccine candidates linked to diphtheria toxin and a live-attenuated oral vaccine candidate are currently in preclinical development. As promising vaccine candidates are advanced along the development pipeline, an adequate supply of vaccines will need to be ensured to meet growing demand, particularly in the most affected countries.