191 research outputs found
Vector cross product differential and difference equations in R^3 and in R^7
Through a matrix approach of the 2-fold vector cross product in R^3 and in R^7, some vector cross product
di erential and di erence equations are studied. Either the classical theory or convenient Drazin inverses, of elements belonging
to the class of index 1 matrices, are applied.MTM2017-83506-C2-2-P (Spain)info:eu-repo/semantics/publishedVersio
Humoral immune response against allogeneic equine mesenchymal stem cells (MSCs) mediated by the major histocompatibility complex (MHC): an issue to take into account for the safety and efficacy of treatment with MSCs
Allogeneic mesenchymal stem cells (MSCs) present several advantages, but recipient immune response needs to be further elucidated. Proinflammatory priming of MSCs activated their in vivo regulatory capacity, but repeated administrations led to slight inflammatory reaction in an osteoarthritis equine model. This may be associated with higher major histocompatibility complex (MHC) expression, which would increase MSC immunogenicity potentially inducing humoral mediated immune memory. This study aimed at assessing allo-antibody production against donor’s equine MHC (equine leukocyte antigen, ELA) in animals that received intra-articular repeated administration of allogeneic MSC-primed. For this purpose, we used stored samples from a previous study. Donor and recipients ELA-haplotypes were stablished by microsatellite typing and complementmediated microcytoxicity assays were carried out by exposing target cells from the donor (unstimulated MSCs [MSC-nai¨ve], MSC-primed or lymphocytes [control]) to sera collected at different time-points from 10 recipients: ELA-mismatched MSCnai ¨ve recipients, ELA-mismatched MSC-primed recipients or ELA-partially matched MSC-primed recipients. All animals receiving allogeneic MSCs produced allo-antibodies after the first injection, regardless of the matching degree. However, antibody peak production after second administration was only observed in ELA-mismatched recipients, both of MSC-nai¨ve and MSCprimed. Horses injected with MSC-primed produced fewer antibodies but MSC-primed were more targeted in the microcytoxicity assay. Thus, activated immunomodulatory profile of MSC-primed could have led to slighter humoral response after ..
Comparison of autologous bone marrow and adipose tissue derived mesenchymal stem cells, and platelet rich plasma, for treating surgically induced lesions of the equine superficial digital flexor tendon
Several therapies have been investigated for equine tendinopathies, but satisfactory long term results have not been achieved consistently and a better understanding of the healing mechanism elicited by regenerative therapies is needed. The aim of this study was to assess the separate effects of autologous bone marrow (BM) and adipose tissue (AT) derived mesenchymal stem cells (MSCs), and platelet rich plasma (PRP), for treating lesions induced in the superficial digital flexor tendon (SDFT) of horses. Lesions were created surgically in both SDFTs of the forelimbs of 12 horses and were treated with BM-MSCs (six tendons), AT-MSCs (six tendons) or PRP (six tendons). The remaining six tendons received lactated Ringer''s solution as control. Serial ultrasound assessment was performed prior to treatment and at 2, 6, 10, 20 and 45 weeks post-treatment. At 45 weeks, histopathology and gene expression analyses were performed. At week 6, the ultrasound echogenicity score in tendons treated with BM-MSCs suggested earlier improvement, whilst all treatment groups reached the same level at week 10, which was superior to the control group. Collagen orientation scores on histological examination suggested a better outcome in treated tendons. Gene expression was indicative of better tissue regeneration after all treatments, especially for BM-MSCs, as suggested by upregulation of collagen type I, decorin, tenascin and matrix metalloproteinase III mRNA. Considering all findings, a clear beneficial effect was elicited by all treatments compared with the control group. Although differences between treatments were relatively small, BM-MSCs resulted in a better outcome than PRP and AT-MSCs
Lorentz and CPT symmetries in commutative and noncommutative spacetime
We investigate the fermionic sector of a given theory, in which massive and
charged Dirac fermions interact with an Abelian gauge field, including a non
standard contribution that violates both Lorentz and CPT symmetries. We offer
an explicit calculation in which the radiative corrections due to the fermions
seem to generate a Chern-Simons-like effective action. Our results are obtained
under the general guidance of dimensional regularization, and they show that
there is no room for Lorentz and CPT violation in both commutative and
noncommutative spacetime.Comment: RevTex4, 7 pages, to be published in J. Phys.
Uso de marcadores moleculares para seleção e introdução de novos acessos de moringa.
A Moringa oleifera Lam., pertence à família Moringaceae e foi introduzida no Brasil como planta ornamental por volta de 1950. Atualmente é amplamente cultivada por sua característica de espécie multiuso. O objetivo do presente trabalho foi avaliar a diversidade genética de moringa, oriundas de sementes, para introdução de acessos no Banco Ativo de Germoplasma, implantado pela Embrapa Tabuleiros Costeiros. Foram testados sete primers ISSR, que resultaram em 32 fragmentos polimórficos (100%). A distância genética entre os indivíduos será utilizada para seleção dos que serão inseridos no BAG moringa
Caracterização físico-química da primeira colheita do banco ativo de germoplasma de mangaba da Embrapa Tabuleiros Costeiros.
Caracterização molecular de acessos de jenipapeiro.
O Banco Ativo de Germoplasma de Jenipapo pertencente a Embrapa Tabuleiros Costeiros foi implantado em 2009, no Campo Experimento Jorge Sobral em Nossa Senhora das Dores, visando a conservação do material genético. O objetivo desse trabalho foi realizar a caracterização molecular e avaliar a diversidade genética de 160 indivíduos de 18 acessos de jenipapo por meio de marcadores moleculares ISSR. Os resultados mostraram através da análise de agrupamento ACoP a formação de quatro grupos. Há um grande número de indivíduos agrupados no grupo I da ACoP, indicando pouca divergência entre eles. Os grupos I, II e III, se agruparam em posições diferentes no dendrograma, porém na ACoP estão relacionados. O grupo IV é o mais diferente dos demais grupos. A análise comparativa dos agrupamentos revelou que os marcadores ISSR foram eficientes para a caracterização molecular e existe variabilidade genética entre os acessos
High field level crossing studies on spin dimers in the low dimensional quantum spin system NaT(CO)(HO) with T=Ni,Co,Fe,Mn
In this paper we demonstrate the application of high magnetic fields to study
the magnetic properties of low dimensional spin systems. We present a case
study on the series of 2-leg spin-ladder compounds
NaT(CO)(HO) with T = Ni, Co, Fe and Mn. In all
compounds the transition metal is in the high spin configuation. The
localized spin varies from S=1 to 3/2, 2 and 5/2 within this series. The
magnetic properties were examined experimentally by magnetic susceptibility,
pulsed high field magnetization and specific heat measurements. The data are
analysed using a spin hamiltonian description. Although the transition metal
ions form structurally a 2-leg ladder, an isolated dimer model consistently
describes the observations very well. This behaviour can be understood in terms
of the different coordination and superexchange angles of the oxalate ligands
along the rungs and legs of the 2-leg spin ladder. All compounds exhibit
magnetic field driven ground state changes which at very low temperatures lead
to a multistep behaviour in the magnetization curves. In the Co and Fe
compounds a strong axial anisotropy induced by the orbital magnetism leads to a
nearly degenerate ground state and a strongly reduced critical field. We find a
monotonous decrease of the intradimer magnetic exchange if the spin quantum
number is increased
Alterações em abóbora após cocção.
A abóbora (Cucurbita moschata Duch) é uma olerícola de grande aceitação em todo o Brasil, especialmente na região Nordeste. É bastante utilizada na alimentação diária do nordestino, onde é conhecida por Jerimum, para elaboração de diversos pratos e doces, que podem ser caseiros ou industrializados. Durante o processo de cocção, há perda de nutrientes e alteração na qualidade do alimento a ser consumido. O trabalho foi desenvolvido com o objetivo de avaliar as alterações ocorridas em abóboras após a cocção. Os 115 frutos avaliados foram oriundos do programa de melhoramento de abóbora da Embrapa Tabuleiros Costeiros (CPATC), colhidos em outubro de 2013, no Campo Experimental Pedro Arle, locali zado no município de Frei Paulo, Sergipe. As análises foram realizadas na Sala de Pós-colheita do CPATC, em Aracaju. Os pedaços, pesando cerca de 200g foram fervidos em 1L de água, onde permaneceram por cinco minutos. Antes e após a cocção, todas as amostras foram avaliadas quanto ao peso da massa fresca, firmeza e teor de sólidos solúveis (SS). Foi realizado o teste de Tukey para comparação de médias, ao nível de 5% de significância, utilizando-se o programa estatístico SAS. Não ocorreu perda de massa fresca significativa, que variou de 142,28g (antes) a 138,27 g (após a cocção). Entretanto, o teor de SS diminuiu significativamente de 11,68 para 11,08ºBrix, e a firmeza, de 12,75 a 5,69N. As características avaliadas neste trabalho, associadas a outras de importância nutricional e comercial, são importantes informações ao programa de melhoramento da espécie
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