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Root proliferation in native perennial grasses of arid Patagonia,Argentina

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Journal of Arid Land 2014年第2期6卷 195-204页

作者： Yanina A TORRES Carlos A BUSSO Oscar A MONTENEGRO Leticia ITHURRART Hugo D GIORGETT gustavo RODRíGUEZ Diego BENTIVEGNA Roberto E BREVEDAN Osvaldo A FERNández María M MUJICA Sandra S BAIONI José ENTíO María N FIORETTI Guillermo TUCAT Agronomy Department National University of the South and CERZOS (CONICET) Experimental Farm EEA INTA Patagones Ministery of Agrarian Issues Faculty of Agrarian Sciences National University of La Plata

Pappophorum vaginatum is the most abundant C4 perennial grass desirable to livestock in rangelands of northeastern Patagonia, Argentina. We hypothesized that （1） defoliation reduce net primary productivity, and root length density and weight in the native species, and （2） root net primary productivity, and root length density and weight, are greater in P. vaginatum than in the other, less desirable, native species （i.e., Aristida spegazzinfi, A. subulata and Sporobolus cryptandrus）. Plants of all species were either exposed or not to a severe defoliation twice a year during two growing seasons. Root proliferation was measured using the cylinder method. Cylindrical, iron structures, wrapped up using nylon mesh, were buried diagonally from the periphery to the center on individual plants. These structures, initially filled with soil without any organic residue, were dug up from the soil on 25 April 2008, after two successive defoliations in mid-spring 2007. During the second growing season （2008-2009）, cylinders were destructively harvested on 4 April 2009, after one or two defoliations in mid- and/or late-spring, respectively. Roots grown into the cylinders were obtained after washing the soil manually. Defoliation during two successive years did reduce the study variables only after plants of all species were defoliated twice, which supported the first hypothesis. The greater root net primary productivity, root length den- sity and weight in P. vaginatum than in the other native species, in support of the second hypothesis, could help to explain its greater abundance in rangelands of Argentina.

关键词： Aristida species competitive ability Pappophorum vaginatum Sporobolus cryptandrus warm-season perennial grasses

Morphological Characterization of Brazil Nut Tree (Bertholletia excelsa) Fruit Pericarp

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Journal of Renewable Materials 2019年第7期7卷 683-692页

作者： gustavo P.Petrechen Marcos Arduin JoséD.Ambrósio Materials Science and Engineering Postgraduate Program Federal University of São CarlosSão CarlosBrazil Center of Characterization and Materials Development Federal University of São CarlosSão CarlosBrazil Department of Botany Federal University of São CarlosSão CarlosBrazil Citlab-Science Innovation and Technology LaboratorySorocabaBrazil

This article presents the overall morphological structure of the Brazil nut tree(Bertholletia excelsa)fruit pericarp,from macro to nano *** acquired knowledge would be used for the development of new applications,like using the materials as fillers for biocomposites,or as a hierarchical architecture model for *** research was performed using stereo and light microscopy and conventional and force field emission scanning electron *** pericarp presents three layers:the exocarp,a dark gray,brittle and fragile outer layer;the mesocarp,a beige,dry,rigid,impermeable and fibrous intermediate layer;and the endocarp,an inner layer with similar characteristic as the exocarp,but formed next to the ***,the exocarp and the endocarp presented minor regions of sclereids,fibers and vascular cell bundles,inside major regions of parenchyma *** mesocarp presents a structure of fiber cells regions alternating with sclereids and vascular cells regions,arranged in a composite like arrangement,with the fibers cells bundles acting as randomly oriented disperse phases in a sclereid cells *** arrangement was associated with the mesocarp relative superior proprieties,indicating a great material for using as fillers for biocomposites or in biomimetics applications.

关键词： Bertholletia excelsa brazil nut fruit pericarp morphological structure microscopy

Evaluation of biostimulation and Tween 80 addition for the bioremediation of long-term DDT-contaminated soil

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Journal of Environmental Sciences 2015年第2期27卷 101-109页

作者： Bibiana Betancur-Corredor Nancy J.Pino Santiago Cardona gustavo A.Peuela GDCON Research Group Faculty of Engineering University Research Headquarters (SIU) University of Antioquia School of Geosciences and Environment Faculty of Mines National University of Colombia School of Microbiology University of Antioquia

The bioremediation of a long-term contaminated soil through biostimulation and surfactant addition was evaluated. The concentrations of 1,1,1-trichloro-2,2-bis（4-chlorophenyl）ethane（DDT） and its metabolites 1,1-dichloro-2,2-bis（4-chlorophenyl） ethane（DDD） and1,1-dichloro-2,2-bis（4-chlorophenyl） ethylene（DDE） were monitored during an 8-week remediation process. Physicochemical characterization of the treated soil was performed before and after the bioremediation process. The isolation and identification of predominant microorganisms during the remediation process were also carried out. The efficiency of detoxification was evaluated after each bioremediation protocol. Humidity and p H and the heterotrophic microorganism count were monitored weekly. The DDT concentration was reduced by 79% after 8 weeks via biostimulation with surfactant addition（B ＋ S） and 94.3%via biostimulation alone（B）. Likewise, the concentrations of the metabolites DDE and DDD were reduced to levels below the quantification limits. The microorganisms isolated during bioremediation were identified as Bacillus thuringiensis, Flavobacterium sp., Cuprivadius sp.,Variovorax soli, Phenylobacterium sp. and Lysobacter sp., among others. Analysis with scanning electron microscopy（SEM） allowed visualization of the colonization patterns of soil particles. The toxicity of the soil before and after bioremediation was evaluated using Vibrio fischeri as a bioluminescent sensor. A decrease in the toxic potential of the soil was verified by the increase of the concentration/effect relationship EC50 to 26.9% and 27.2% for B ＋ S and B, respectively, compared to 0.4% obtained for the soil before treatment and 2.5%by natural attenuation after 8 weeks of treatment.

关键词： DDT Soil Bioremediation Biostimulation Surfactant Toxicity

Complementarity of electric vehicles and pumped-hydro as energy storage in small isolated energy systems:case of La Palma,Canary Islands

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Journal of Modern Power Systems and Clean Energy 2016年第4期4卷 604-614页

作者： Alfredo RAMIREZ-DIAZ Francisco J.RAMOS-REAL gustavo A.MARRERO Departamento de Economı´a Contabilidad y FinanzasFacultad de Economı´aEmpresa y TurismoUniversidad de La Laguna38071 La LagunaSpain Instituto Universitario de Ciencias Polı´ticas y Sociales Universidad de La Laguna38071 La LagunaSpain Instituto Universitario de Desarrollo Regional Universidad de La Laguna38071 La LagunaSpain

Isolated energy systems in archipelagos are characterized for having a great dependence on fossil sources due to isolation and territorial *** island of La Palma is situated on the northwest of the Canary Islands,and its electric system is very *** policies planned by local authorities are aimed to increase the share of renewable energies and the reduction of fossil ***,intermittence and the concentration of unmanageable renewable energies in few locations may hinder the operation of the *** order to solve these problems,energy storage plays an essential *** aim of this paper is to analyse the effects of the introduction of two possible alternatives as a way of energy storage:pumped hydro storage and electric *** this,we use a simulation model adapted to the features of La Palma,considering different *** show that,in the most favourable scenario,the installation of an additional 25 MW from renewables(more than double the current power),supported by 20 MW of pumped hydro storage and a fleet of 3361 electric vehicles,would allow the current share of renewables to increase from11%(in 2015)to 49%.Furthermore,this would mean a 26%reduction in CO2 emissions,10%in costs of generated k Wh and 19%in energy dependence.

关键词： Energy storage Electric vehicles Vehicle-to-grid Grid-for-vehicles Pumped-hydro energy storage Isolated systems

Decoupling the adsorption mechanisms of arsenate at molecular level on modified cube-shaped sponge loaded superparamagnetic iron oxide nanoparticles

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Journal of Environmental Sciences 2022年第11期34卷 1-12页

作者： Xiang-Yang Lou Roberto Boada Veronica Verdugo Laura Simonelli gustavo Pérez Manuel Valiente GTS-UAB Research Group Department of ChemistryFacultat de CiènciesUniversitat Autonoma de Barcelona08193 BellaterraSpain ALBA Synchrotron Carrer de la llum 2-26Cerdanyola del Valles08290 BarcelonaSpain Centro de Excelencia en Nanotecnologia Leitat ChileSantiago 7500724Chile

In this study, a commercial cube-shaped open-celled cellulose sponge adsorbent was modified by in-situ co-precipitation of superparamagnetic iron oxide nanoparticles(SPION) and used to remove As(V) from aqueous solutions. Fe K-edge X-ray absorption spectroscopy(XAS) and TEM identified maghemite as the main iron phase of the SPION nanoparticles with an average size 13 nm. Batch adsorption experiments at 800 mg/L showed a 63% increase of adsorption capacity when loading 2.6 wt.% mass fraction of SPION in the *** determination of the adsorption thermodynamic parameters indicated that the As(V) adsorption on the composite material is a spontaneous and exothermic *** K-edge XAS results confirmed that the adsorption enhancement on the composite can be attributed to the nanoparticles loaded. In addition, adsorbed As(V) did not get reduced to more toxic As(Ⅲ) and formed a binuclear corner-sharing complex with SPION. The advantageous cube-shape of the sponge-loaded SPION composite together with its high affinity and good adsorption capacity for As(V), good regeneration capability and the enhanceddiffusion attributed to its open-celled structure make this adsorbent a good candidate for industrial applications.

关键词： Adsorption Cube composite adsorbent Arsenate removal Regeneration X-ray absorption spectroscopy

Epidermal stem cells and skin tissue engineering in hair follicle regeneration

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World Journal of Stem Cells 2015年第4期7卷 711-727页

作者： María Eugenia Balaná hernán Eduardo Charreau gustavo Jose Leirós Fundación Pablo Cassará-Instituto de Ciencia y Tecnología Dr.César Milstein Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET)Saladillo 2468 C1440FFXCiudad de Buenos AiresArgentina Technology Intelligence Unit ClarkeModet&C°Lavalle 1903°PisoC1047AAD Buenos AiresArgentina

The reconstitution of a fully organized and functional hair follicle from dissociated cells propagated under defined tissue culture conditions is a challenge stillpending in tissue engineering. The loss of hair follicles caused by injuries or pathologies such as alopecia not only affects the patients' psychological well-being, but also endangers certain inherent functions of the skin. It is then of great interest to find different strategies aiming to regenerate or neogenerate the hair follicle under conditions proper of an adult individual. Based upon current knowledge on the epithelial and dermal cells and their interactions during the embryonic hair generation and adult hair cycling, many researchers have tried to obtain mature hair follicles using different strategies and approaches depending on the causes of hair loss. This review summarizes current advances in the different experimental strategies to regenerate or neogenerate hair follicles, with emphasis on those involving neogenesis of hair follicles in adult individuals using isolated cells and tissue engineering. Most of these experiments were performed using rodent cells, particularly from embryonic or newborn origin. However, no successful strategy to generate human hair follicles from adult cells has yet been reported. This review identifies several issues that should be considered to achieve this objective. Perhaps the most important challenge is to provide threedimensional culture conditions mimicking the structure of living tissue. Improving culture conditions that allow the expansion of specific cells while protecting their inductive properties, as well as methods for selecting populations of epithelial stem cells, should give us the necessary tools to overcome the difficulties that constrain human hair follicle neogenesis. An analysis of patent trends shows that the number of patent applications aimed at hair follicle regeneration and neogenesis has been increasing during the last decade. This fiel

关键词： Adult stem cells Skin grafts Epidermis Multipotential differentiation Tissue regeneration Dermal papilla Epithelial-mesenchymal interactions

Effects of antioxidant-rich Lactiplantibacillus plantarum inoculated alfalfa silage on rumen fermentation,antioxidant and immunity status, and mammary gland gene expression in dairy goats.

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Heat shock protein 20 promotes sirtuin 1-dependent cell proliferation in induced pluripotent stem cells

畜牧与生物技术杂志(英文版) 2024年第3期 1227页

作者： Yixin Zhang Samaila Usman Qiang Li Fuhou Li Xia Zhang Luiz gustavo Nussio Xusheng Guo

来源：博看期刊评论

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World Journal of Stem Cells 2021年第6期13卷 659-669页

作者： Mujib Ullah Nicole Pek Min Qian gustavo Yannarelli Asma Akbar Institute for Immunity and Transplantation Stem Cell Biology and Regenerative MedicineSchool of MedicineStanford UniversityStanfordCA 94304United States Immunology and School of Medicine Stanford UniversityStanfordCA 94304United States Laboratorio de Regulación Génica y Células Madre Instituto de Medicina TraslacionalTrasplante y Bioingeniería(IMeTTyB)Universidad Favaloro-CONICETBuenos Aires 1078Argentina Institute for Molecular Medicine School of MedicineStanford UniversityStanfordCA 94304United States

BACKGROUND Heat shock proteins(HSPs)are molecular chaperones that protect cells against cellular stresses or ***,it has been increasingly recognized that they also play crucial roles in regulating fundamental cellular ***20 has been implicated in cell proliferation,but conflicting studies have shown that it can either promote or suppress *** underlying mechanisms by which HSP20 regulates cell proliferation and pluripotency remain *** the effect of HSP20 on cell proliferation has been recognized,its role in inducing pluripotency in human-induced pluripotent stem cells(iPSCs)has not been *** To evaluate the efficacy of HSP20 overexpression in human iPSCs and evaluate the ability to promote cell *** purpose of this study was to investigate whether overexpression of HSP20 in iPSCs can increase pluripotency and *** We used iPSCs,which retain their potential for cell ***20 overexpression effectively enhanced cell proliferation and *** of HSP20 in iPSCs was characterized by immunocytochemistry staining and realtime polymerase chain *** also used cell culture,cell counting,western blotting,and flow cytometry analyses to validate HSP20 overexpression and its *** This study demonstrated that overexpression of HSP20 can increase the pluripotency in ***,by overexpressing HSP20 in iPSCs,we showed that HSP20 upregulated proliferation markers,induced pluripotent genes,and drove cell proliferation in a sirtuin 1(SIRT1)-dependent *** data have practical applications in the field of stem cell-based therapies where the mass expansion of cells is needed to generate large quantities of stem cell-derived cells for transplantation *** We found that the overexpression of HSP20 enhanced the proliferation of iPSCs in a SIRT1-dependent ***,we established the distinct crosstalk between HSP20 and SIR

关键词： Heat shock proteins Stem cells Proliferation Induced pluripotent stem cells Sirtuin-1 Heat shock protein 20 Pluripotency

Urethane Modified Hydrophobic Compact Wood Pulp Paper for Oil Spill Cleanup: A Preliminary Study

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Journal of Renewable Materials 2020年第10期8卷 1257-1268页

作者： gustavo de Souza Ricardo K.Kramer Antonio J.F.Carvalho Department of Materials Engineering Sao Carlos School of Engineering(EESC)University of São Paulo(USP)São PauloBrazil

Oil spills and oil/water wastewater are among the great concerns regarding oil *** technologies face many limitations and in some cases are responsible for causing secondary pollution,therefore there is as seek for environmental friendly ***,from which celluloses are highlighted,are being employed for oil/water separation or oil absorbents ***,these membranes are obtained by freeze drying of CNF(cellulose nano-fibrils)suspensions followed by chemical modification for hydrophobization,which involves expensive process as chemical vapor deposition and expensive reactants as sylanes,turning these processes hardly ***,we produced a natural porous structure paper from eucalyptus pulp fibers modified by a dipping and heating process in a blocked diisocyanate *** the surface treatment,contact angle with water reached 144°and water absorption reduced seven times,keeping the good oil *** chemical modification process is simple to be performed and use a very low quantity of reactant estimated to be less than 0.1 wt%based on *** good mechanical properties of the material allows its use in non usual conditions which can be of great importance depending on the environmental conditions.

关键词： Cellulose oil removal hydrophobization water repellency blocked isocyanates