3,350 research outputs found
Evaluation of Microencapsulation of The UFV-AREG1 Bacteriophage in Alginate-Ca Microcapsules using Microfluidic Devices
The indiscriminate use of antibiotics and the emergence of resistant
microorganisms have become a major challenge for the food industry. The purpose
of this work was to microencapsulate the bacteriophage UFV-AREG1 in a calcium
alginate matrix using microfluidic devices and to study the viability and
efficiency of retention. The microcapsules were added to gel of propylene
glycol for use as an antimicrobial in the food industry. The technique showed
the number of the phage encapsulation, yielding drops with an average 100-250
m of diameter, 82.1 2% retention efficiency and stability in the gel
matrix for 21 days. The gel added to the microencapsulated phage showed
efficiency (not detectable on the surface) in reducing bacterial contamination
on the surface at a similar level to antimicrobial chemicals (alcohol 70%).
Therefore, it was possible to microencapsulate bacteriophages in alginate-Ca
and apply the microcapsules in gels for use as sanitizers in the food industry.Comment: 8 pages, 5 figure
Two interacting diffusing particles on low-dimensional discrete structures
In this paper we study the motion of two particles diffusing on
low-dimensional discrete structures in presence of a hard-core repulsive
interaction. We show that the problem can be mapped in two decoupled problems
of single particles diffusing on different graphs by a transformation we call
'diffusion graph transform'. This technique is applied to study two specific
cases: the narrow comb and the ladder lattice. We focus on the determination of
the long time probabilities for the contact between particles and their
reciprocal crossing. We also obtain the mean square dispersion of the particles
in the case of the narrow comb lattice. The case of a sticking potential and of
'vicious' particles are discussed.Comment: 9 pages, 6 postscript figures, to appear in 'Journal of Physics
A',-January 200
Yield and fruit quality of Santa Cruz and Italian tomatoes depending on fruit thinning
O manejo do tomateiro cultivado em ambiente protegido, com ênfase no raleio de frutos, pode contribuir de forma significativa para a produção de frutos de qualidade superior, expressando assim o potencial de cada cultivar. Foi avaliado o efeito do raleio de frutos na produtividade e seus componentes e em alguns atributos de qualidade de frutos de genótipos de tomateiro dos segmentos Santa Cruz e Italiano de crescimento indeterminado, visando ao consumo in natura. Avaliaram-se 12 genótipos de tomate de mesa (seis hÃbridos experimentais e seis cultivares) e dois modos de condução (plantas conduzidas com e sem raleio de frutos). O experimento foi com parcelas subdivididas, distribuÃdas em blocos completos ao acaso com três repetições. As parcelas foram representadas pelos genótipos e as subparcelas pelos modos de condução. Avaliaram-se o número de frutos por planta, produtividade comercial de frutos, produtividade de frutos não-comercializáveis, massa média do fruto, comprimento e largura do fruto, pH, teor de sólidos solúveis totais (SS), acidez titulável (AT), relação entre SS e AT, teor de ácido ascórbico e teor de licopeno. O raleio dos frutos proporcionou incremento da produtividade comercial, massa média, comprimento e largura do fruto para os hÃbridos THX-02 e THX-03, do segmento Santa Cruz, e THX-04, THX-05 e Netuno, do segmento Italiano e não mostrou vantagens para a produção e seus componentes para os demais genótipos e caracterÃsticas avaliadas. Considerando o raleio de frutos, os genótipos Giuliana e Sahel obtiveram maior produtividade comercial e massa média do fruto. Sem o raleio de frutos, 'Netuno' alcançou maior número de frutos por planta, porém, o hÃbrido Sahel foi quem se destacou por apresentar maior produtividade comercial e massa média do fruto. O raleio não influenciou a qualidade organoléptica dos genótipos avaliados. 'Avalon' apresentou maior teor de ácido ascórbico que 'Netuno' e 'Sahel'. 'Débora Max', THX-01, THX-02 e THX-04 foram semelhantes entre si quanto ao teor de licopeno e superaram 'Giuliana', 'Sahel', THX-03 e THX-06.The management of the tomato plant under greenhouse, with emphasis on fruit thinning, contributes significantly to the production of fruits of superior quality, expressing the potential of each cultivar. We determined the effect of fruit thinning on yield and its components in tomato hybrids of the Santa Cruz and Italian types of indeterminate growth, and we performed the qualitative characterization of the fruits, aiming in natura market. Twelve fresh-market tomato genotypes (six experimental hybrids and six commercial cultivars) and two training methods (with and without manual fruit thinning) were evaluated. A randomized complete block design was used in this trial, with split-plots and three replications. The plots were represented by genotypes and the subplots were constitued by training methods. Number of fruits per plant, yield of marketable and not marketable fruits, average fruit weight, fruit length and fruit width were measured. For quantitative characterization, pH, soluble solids concentration (SS), tritratable acidity (AT), ascorbic acid content, SS and AT ratio and lycopene content were measured. The fruit thinning increased marketable yield, average weight, length and width for the Santa Cruz hybrids THX-02 and THX-03 and for THX-04, THX-05 and Netuno, classified as Italian type. The fruit thinning did not provide benefits for yield and its components for the other evaluated characteristics and genotypes. Giuliana and Sahel genotypes presented higher marketable yield and average fruit weight. Without fruit thinning, 'Netuno' reached the highest number of fruits per plant, but the hybrid Sahel showed higher marketable yield and average fruit weight. Thinning did not affect the organoleptic quality of the genotypes. 'Avalon' showed higher ascorbic acid content than 'Netuno' and 'Sahel', and 'Débora Max', 'THX-01', 'THX-02' and 'THX-04', which were similar to each other in the content of lycopene, overcame 'Giuliana', 'Sahel', 'THX-03', and 'THX-06'.FAPESPCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES
Avaliação da presença de anticorpos IgG anti-Schistosoma mansoni no soro de pacientes com esquistossomose mansônica crônica, antes e após tratamento especÃfico
The circumoval precipitin test (COPT), enzyme-linked immunosorbent assay (ELISA) and the immunoblotting anti-adult worm antigen (AWA) and soluble egg antigen (SEA) tests were applied to 17 chronically schistosome-infected patients for the detection of anti-Schistosoma mansoni antibodies before and on four occasions after oxamniquine administration over a period of six months. Compared to a control group, schistosomiasis patients showed high levels of IgG antibodies in AWA and SEA-ELISA. A decrease in IgG levels was observed six months after treatment, although negative reactions were not obtained. Significant decreases in IgG1, IgG3 and, mainly, IgG4, but not anti-SEA IgG2 levels were observed six months after treatment, again without negativity. Analysis of anti-AWA IgG antibodies by immunoblotting before treatment showed a 31 kDa strand in 14 patients (82%) which disappeared in three cases up to six months after treatment; furthermore, anti-SEA IgG antibodies showed the same band in nine patients (53%) before treatment, which disappeared in only four cases up to six months after treatment.Em 17 pacientes com infecção crônica por Schistosoma mansoni utilizaram-se os testes de reação periovular, imunoenzimático (ELISA) e imunoblotting, empregando-se antÃgenos obtidos a partir de vermes adultos (AWA) ou de ovos de S. mansoni (SEA), para detecção de anticorpos anti-S. mansoni, antes e em quatro ocasiões após tratamento com oxamniquine. Quando cotejados a grupo controle os pacientes esquistossomóticos revelaram altos nÃveis séricos de anticorpos IgG nos testes ELISA (anti-AWA e anti-SEA), não se observando, porém, negativação até seis meses após tratamento especÃfico. Encontrou-se, entretanto, decréscimo significativo, sem negativação, dos nÃveis de IgG1, IgG3 e, principalmente, IgG4, quando se utilizou antÃgeno solúvel obtido a partir de ovos de S. mansoni (SEA), seis meses após administração de oxamniquine. O mesmo não foi observado no caso de anticorpos da subclasse IgG2. Nos imunoblottings efetuados com o emprego de antÃgeno de verme adulto (AWA), antes do tratamento com oxamniquine, evidenciou-se a presença de banda com 31 kDa em 14 (82%) dos 17 pacientes estudados, observando-se seu desaparecimento em três pacientes examinados seis meses após tratamento especÃfico. Quando se utilizou antÃgeno obtido a partir de ovos de S. mansoni (SEA) a mesma banda foi evidenciada em nove pacientes, desaparecendo em quatro casos, após o tratamento
Metric Features of a Dipolar Model
The lattice spin model, with nearest neighbor ferromagnetic exchange and long
range dipolar interaction, is studied by the method of time series for
observables based on cluster configurations and associated partitions, such as
Shannon entropy, Hamming and Rohlin distances. Previous results based on the
two peaks shape of the specific heat, suggested the existence of two possible
transitions. By the analysis of the Shannon entropy we are able to prove that
the first one is a true phase transition corresponding to a particular melting
process of oriented domains, where colored noise is present almost
independently of true fractality. The second one is not a real transition and
it may be ascribed to a smooth balancing between two geometrical effects: a
progressive fragmentation of the big clusters (possibly creating fractals), and
the slow onset of a small clusters chaotic phase. Comparison with the nearest
neighbor Ising ferromagnetic system points out a substantial difference in the
cluster geometrical properties of the two models and in their critical
behavior.Comment: 20 pages, 15 figures, submitted to JPhys
Optimal use of time dependent probability density data to extract potential energy surfaces
A novel algorithm was recently presented to utilize emerging time dependent
probability density data to extract molecular potential energy surfaces. This
paper builds on the previous work and seeks to enhance the capabilities of the
extraction algorithm: An improved method of removing the generally ill-posed
nature of the inverse problem is introduced via an extended Tikhonov
regularization and methods for choosing the optimal regularization parameters
are discussed. Several ways to incorporate multiple data sets are investigated,
including the means to optimally combine data from many experiments exploring
different portions of the potential. Results are presented on the stability of
the inversion procedure, including the optimal combination scheme, under the
influence of data noise. The method is applied to the simulated inversion of a
double well system.Comment: 34 pages, 5 figures, LaTeX with REVTeX and Graphicx-Package;
submitted to PhysRevA; several descriptions and explanations extended in Sec.
I
Selenotriapine – An isostere of the most studied thiosemicarbazone with pronounced pro-apoptotic activity, low toxicity and ability to challenge phenotype reprogramming of 3-D mammary adenocarcinoma tumors
Triapine, the most studied α-N-heterocyclic thiosemicarbazone, revealed potent activity against advanced leukemia, but was ineffective against a variety of solid tumors. Moreover, methemoglobinemia, which is a side effect of triapine administration, may limits all clinical application. To enhance anticancer activity and reduce side effects, we applied an isosteric replacement of sulfur to selenium atom was performed by synthesis and characterization of selenium triapine analog, 3-aminopyridine-2-carboxaldehyde selenosemicarbazone (selenotriapine). Compared to triapine, selenotriapine revealed superior pro-apoptotic activity with activation of intrinsic apoptotic pathway in both human monocytic leukemia (THP-1) and mammary adenocarcinoma (MCF-7) cell lines. For MCF-7 2-D cultures, selenotriapine induced notable increase in mitochondrial superoxide radical generation and dissipation of mitochondrial transmembrane potential. A significant delay in growth of MCF-7 spheroids (3-D culture) was accompanied by phenotypic stem cell reprogramming (Oct-4 expression). Additionally, selenotriapine demonstrated a very low toxicity profile as compared to triapine, confirmed over alleviated extent of methemoglobin formation and higher IC50 value in brine shrimp cytotoxicity assay
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