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1.
Phys Rev E ; 108(3-1): 034115, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37849126

RESUMO

We investigate the transport properties of a complex porous structure with branched fractal architectures formed due to the gradual deposition of dimers in a model of multilayer adsorption. We thoroughly study the interplay between the orientational anisotropy parameter p_{0} of deposited dimers and the formation of porous structures, as well as its impact on the conductivity of the system, through extensive numerical simulations. By systematically varying the value of p_{0}, several critical and off-critical scaling relations characterizing the behavior of the system are examined. The results demonstrate that the degree of orientational anisotropy of dimers plays a significant role in determining the structural and physical characteristics of the system. We find that the Einstein relation relating to the size scaling of the electrical conductance holds true only in the limiting case of p_{0}→1. Monitoring the fractal dimension of the interface of the multilayer formation for various p_{0} values, we reveal that in a wide range of p_{0}>0.2 interface shows the characteristic of a self-avoiding random walk, compared to the limiting case of p_{0}→0 where it is characterized by the fractal dimension of the backbone of ordinary percolation cluster at criticality. Our results thus can provide useful information about the fundamental mechanisms underlying the formation and behavior of wide varieties of amorphous and disordered systems that are of paramount importance both in science and technology as well as in environmental studies.

2.
Phys Rev E ; 106(3-1): 034120, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36266888

RESUMO

In this paper, we study the transport properties (percolation and conductivity) of a two-dimensional structure created by depositing dimers on a one-dimensional substrate where multilayer deposition is allowed. Specifically, we are interested in studying how the mentioned properties vary as a function of the height of the multilayer. The critical parameters of the percolation transition are calculated using finite-size scaling analysis, obtaining the scaling laws for the probability of percolation and the conductivity of the system. To calculate the electrical conductivity of the multilayer, we use the Frank-Lobb algorithm.

5.
Braz. j. biol ; 82: e237604, 2022. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1285586

RESUMO

This study goal to evaluate the effects of different concentrations of lead (Pb) and silver (Ag) on germination, initial growth and anatomical alterations of Lactuca sativa L. Plants use various mechanisms to reduce the impacts caused by anthropic action, such as xenobiotic elements of soils and water contaminated by heavy metals. These metals were supplied as lead nitrate and silver nitrate and the following treatments were established: control for both metals, maximum dose of heavy metals, for arable soils, allowed by the National Council of the Environment (Ag = 25 mg. Kg-1, Pb = 180 mg. Kg-1), double (Ag = 50 mg. Kg-1, Pb = 360 mg. Kg-1) and triple (Ag = 75 mg. Kg-1, Pb = 540 mg. Kg -1) of this dosage. Vigor and germination tests of the seeds and possible anatomical changes in the leaves and roots of lettuce plants were performed. The species showed a high capacity to germinate under Pb and Ag stress, and the germination was never completely inhibited; however, the germination decreased with increasing Pb concentrations, but not under Ag stress. The use of increasing doses of metals reduced seed vigor and increased chlorophyll content. An increase in biomass was also observed in plants from treatments submitted to Pb. The phytotoxic effects of metals were more pronounced at 15 days after sowing. Anatomically, L. sativa was influenced by metal concentrations, and had a reduction of up to 79.9% in root epidermis thickness at the highest Pb concentration, although some structures did not suffer significant changes. The results suggest that L. sativa presents tolerance to high concentrations of heavy metals, showing possible mechanisms to overcome the stress caused by these metals. In this research lettuce possibly used the mechanism of exclusion of metals retaining Pb and Ag in the roots preserving the photosynthetic apparatus in the aerial part of the plants. In general, the chemical element Pb was more toxic than Ag, in these experimental conditions.


Este estudo teve como objetivo avaliar os efeitos de diferentes concentrações de chumbo (Pb) e prata (Ag) na germinação, crescimento inicial e alterações anatômicas de Lactuca sativa L. As plantas utilizam vários mecanismos para reduzir os impactos causados pela ação antrópica, como elementos xenobióticos de solos e água contaminada por metais pesados. Esses metais foram fornecidos como nitrato de chumbo e nitrato de prata e foram estabelecidos os seguintes tratamentos: controle para ambos os metais, dose máxima de metais pesados, para solos cultiváveis, permitida pelo Conselho Nacional do Meio Ambiente (Ag = 25mg.Kg-1, Pb = 180mg.Kg-1), dobro (Ag = 50mg.Kg-1, Pb = 360mg.Kg-1) e triplo (Ag = 75mg.Kg-1, Pb = 540 mg.Kg -1) desta dosagem. Foram realizados testes de vigor e germinação das sementes e possíveis alterações anatômicas nas folhas e raízes das plantas de alface. A espécie apresentou alta capacidade de germinar sob estresse de Ag e Pb, e a germinação nunca foi completamente inibida; entretanto, a germinação diminuiu com o aumento das concentrações de Pb, mas não sob estresse de Ag. O uso de doses crescentes dos metais, reduziu o vigor das sementes e aumentou o teor de clorofila. Também foi observado aumento da biomassa nas plantas a partir dos tratamentos submetidos ao Pb. Os efeitos fitotóxicos dos metais foram mais acentuados aos 15 dias após a semeadura. Anatomicamente, L. sativa foi influenciada pelas concentrações de metais, e teve uma redução de até 79,9% na espessura da epiderme radicular na maior concentração de Pb, embora algumas estruturas não tenham sofrido alterações significativas. Os resultados sugerem que L. sativa apresenta tolerância a altas concentrações de metais pesados, mostrando possíveis mecanismos para superar o estresse causado por esses metais. Nesta pesquisa a alface possivelmente utilizou o mecanismo de exclusão de metais retendo Pb e Ag nas raízes preservando o aparato fotossintético na parte aérea das plantas. De forma geral o elemento químico Pb se mostrou mais tóxico que Ag, nestas condições experimentais.


Assuntos
Poluentes do Solo/toxicidade , Metais Pesados/análise , Metais Pesados/toxicidade , Nitrato de Prata , Solo , Alface , Chumbo/toxicidade , Nitratos/toxicidade
6.
Braz. j. biol ; 82: 1-9, 2022. graf, ilus, tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1468492

RESUMO

This study goal to evaluate the effects of different concentrations of lead (Pb) and silver (Ag) on germination, initial growth and anatomical alterations of Lactuca sativa L. Plants use various mechanisms to reduce the impacts caused by anthropic action, such as xenobiotic elements of soils and water contaminated by heavy metals. These metals were supplied as lead nitrate and silver nitrate and the following treatments were established: control for both metals, maximum dose of heavy metals, for arable soils, allowed by the National Council of the Environment (Ag = 25 mg. Kg-¹, Pb = 180 mg. Kg-¹), double (Ag = 50 mg. Kg-¹, Pb = 360 mg. Kg-¹) and triple (Ag = 75 mg. Kg-¹, Pb = 540 mg. Kg-¹) of this dosage. Vigor and germination tests of the seeds and possible anatomical changes in the leaves and roots of lettuce plants were performed. The species showed a high capacity to germinate under Pb and Ag stress, and the germination was never completely inhibited; however, the germination decreased with increasing Pb concentrations, but not under Ag stress. The use of increasing doses of metals reduced seed vigor and increased chlorophyll content. An increase in biomass was also observed in plants from treatments submitted to Pb. The phytotoxic effects of metals were more pronounced at 15 days after sowing. Anatomically, L. sativa was influenced by metal concentrations, and had a reduction of up to 79.9% in root epidermis thickness at the highest Pb concentration, although some structures did not suffer significant changes. The results suggest that L. sativa presents tolerance to high concentrations of heavy metals, showing possible mechanisms to overcome the stress caused by these metals. In this research lettuce possibly used the mechanism of exclusion of metals retaining Pb and Ag in the roots preserving the photosynthetic apparatus in the aerial part of the plants. In general, the chemical element Pb was more toxic than Ag, in these experimental conditions.


Este estudo teve como objetivo avaliar os efeitos de diferentes concentrações de chumbo (Pb) e prata (Ag) na germinação, crescimento inicial e alterações anatômicas de Lactuca sativa L. As plantas utilizam vários mecanismos para reduzir os impactos causados pela ação antrópica, como elementos xenobióticos de solos e água contaminada por metais pesados. Esses metais foram fornecidos como nitrato de chumbo e nitrato de prata e foram estabelecidos os seguintes tratamentos:controle para ambos os metais, dose máxima de metais pesados, para solos cultiváveis, permitida pelo Conselho Nacional do Meio Ambiente (Ag = 25mg.Kg-¹, Pb = 180mg.Kg-¹), dobro (Ag = 50mg.Kg-¹, Pb = 360mg.Kg-¹) e triplo (Ag = 75mg.Kg-¹, Pb = 540 mg.Kg-¹) desta dosagem. Foram realizados testes de vigor e germinação das sementes e possíveis alterações anatômicas nas folhas e raízes das plantas de alface. A espécie apresentou alta capacidade de germinar sob estresse de Ag e Pb, e a germinação nunca foi completamente inibida; entretanto, a germinação diminuiu com o aumento das concentrações de Pb, mas não sob estresse de Ag. O uso de doses crescentes dos metais, reduziu o vigor das sementes e aumentou o teor de clorofila. Também foi observado aumento da biomassa nas plantas a partir dos tratamentos submetidos ao Pb. Os efeitos fitotóxicos dos metais foram mais acentuados aos 15 dias após a semeadura. Anatomicamente, L. sativa foi influenciada pelas concentrações de metais, e teve uma redução de até 79,9% na espessura da epiderme radicular na maior concentração de Pb, embora algumas estruturas não tenham sofrido alterações significativas. Os resultados sugerem que L. sativa apresenta tolerância a altas concentrações de metais pesados, mostrando possíveis mecanismos para superar o estresse causado por esses metais. Nesta pesquisa a alface possivelmente utilizou o mecanismo de exclusão de metais retendo Pb e Ag nas raízes preservando o aparato [...].


Assuntos
Alface/crescimento & desenvolvimento , Alface/fisiologia , Chumbo/administração & dosagem , Chumbo/toxicidade , Prata/administração & dosagem , Prata/toxicidade
7.
Braz. j. biol ; 822022.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1468679

RESUMO

Abstract This study goal to evaluate the effects of different concentrations of lead (Pb) and silver (Ag) on germination, initial growth and anatomical alterations of Lactuca sativa L. Plants use various mechanisms to reduce the impacts caused by anthropic action, such as xenobiotic elements of soils and water contaminated by heavy metals. These metals were supplied as lead nitrate and silver nitrate and the following treatments were established: control for both metals, maximum dose of heavy metals, for arable soils, allowed by the National Council of the Environment (Ag = 25 mg. Kg-1, Pb = 180 mg. Kg-1), double (Ag = 50 mg. Kg-1, Pb = 360 mg. Kg-1) and triple (Ag = 75 mg. Kg-1, Pb = 540 mg. Kg -1) of this dosage. Vigor and germination tests of the seeds and possible anatomical changes in the leaves and roots of lettuce plants were performed. The species showed a high capacity to germinate under Pb and Ag stress, and the germination was never completely inhibited; however, the germination decreased with increasing Pb concentrations, but not under Ag stress. The use of increasing doses of metals reduced seed vigor and increased chlorophyll content. An increase in biomass was also observed in plants from treatments submitted to Pb. The phytotoxic effects of metals were more pronounced at 15 days after sowing. Anatomically, L. sativa was influenced by metal concentrations, and had a reduction of up to 79.9% in root epidermis thickness at the highest Pb concentration, although some structures did not suffer significant changes. The results suggest that L. sativa presents tolerance to high concentrations of heavy metals, showing possible mechanisms to overcome the stress caused by these metals. In this research lettuce possibly used the mechanism of exclusion of metals retaining Pb and Ag in the roots preserving the photosynthetic apparatus in the aerial part of the plants. In general, the chemical element Pb was more toxic than Ag, in these experimental conditions.


Resumo Este estudo teve como objetivo avaliar os efeitos de diferentes concentrações de chumbo (Pb) e prata (Ag) na germinação, crescimento inicial e alterações anatômicas de Lactuca sativa L. As plantas utilizam vários mecanismos para reduzir os impactos causados pela ação antrópica, como elementos xenobióticos de solos e água contaminada por metais pesados. Esses metais foram fornecidos como nitrato de chumbo e nitrato de prata e foram estabelecidos os seguintes tratamentos: controle para ambos os metais, dose máxima de metais pesados, para solos cultiváveis, permitida pelo Conselho Nacional do Meio Ambiente (Ag = 25 mg.Kg-1, Pb = 180 mg.Kg-1), dobro (Ag = 50 mg.Kg-1, Pb = 360 mg.Kg-1) e triplo (Ag = 75 mg.Kg-1, Pb = 540 mg.Kg -1) desta dosagem. Foram realizados testes de vigor e germinação das sementes e possíveis alterações anatômicas nas folhas e raízes das plantas de alface. A espécie apresentou alta capacidade de germinar sob estresse de Ag e Pb, e a germinação nunca foi completamente inibida; entretanto, a germinação diminuiu com o aumento das concentrações de Pb, mas não sob estresse de Ag. O uso de doses crescentes dos metais, reduziu o vigor das sementes e aumentou o teor de clorofila. Também foi observado aumento da biomassa nas plantas a partir dos tratamentos submetidos ao Pb. Os efeitos fitotóxicos dos metais foram mais acentuados aos 15 dias após a semeadura. Anatomicamente, L. sativa foi influenciada pelas concentrações de metais, e teve uma redução de até 79,9% na espessura da epiderme radicular na maior concentração de Pb, embora algumas estruturas não tenham sofrido alterações significativas. Os resultados sugerem que L. sativa apresenta tolerância a altas concentrações de metais pesados, mostrando possíveis mecanismos para superar o estresse causado por esses metais. Nesta pesquisa a alface possivelmente utilizou o mecanismo de exclusão de metais retendo Pb e Ag nas raízes preservando o aparato fotossintético na parte aérea das plantas. De forma geral o elemento químico Pb se mostrou mais tóxico que Ag, nestas condições experimentais.

8.
Braz J Biol ; 82: e237604, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34105671

RESUMO

This study goal to evaluate the effects of different concentrations of lead (Pb) and silver (Ag) on germination, initial growth and anatomical alterations of Lactuca sativa L. Plants use various mechanisms to reduce the impacts caused by anthropic action, such as xenobiotic elements of soils and water contaminated by heavy metals. These metals were supplied as lead nitrate and silver nitrate and the following treatments were established: control for both metals, maximum dose of heavy metals, for arable soils, allowed by the National Council of the Environment (Ag = 25 mg. Kg-1, Pb = 180 mg. Kg-1), double (Ag = 50 mg. Kg-1, Pb = 360 mg. Kg-1) and triple (Ag = 75 mg. Kg-1, Pb = 540 mg. Kg -1) of this dosage. Vigor and germination tests of the seeds and possible anatomical changes in the leaves and roots of lettuce plants were performed. The species showed a high capacity to germinate under Pb and Ag stress, and the germination was never completely inhibited; however, the germination decreased with increasing Pb concentrations, but not under Ag stress. The use of increasing doses of metals reduced seed vigor and increased chlorophyll content. An increase in biomass was also observed in plants from treatments submitted to Pb. The phytotoxic effects of metals were more pronounced at 15 days after sowing. Anatomically, L. sativa was influenced by metal concentrations, and had a reduction of up to 79.9% in root epidermis thickness at the highest Pb concentration, although some structures did not suffer significant changes. The results suggest that L. sativa presents tolerance to high concentrations of heavy metals, showing possible mechanisms to overcome the stress caused by these metals. In this research lettuce possibly used the mechanism of exclusion of metals retaining Pb and Ag in the roots preserving the photosynthetic apparatus in the aerial part of the plants. In general, the chemical element Pb was more toxic than Ag, in these experimental conditions.


Assuntos
Metais Pesados , Poluentes do Solo , Chumbo/toxicidade , Metais Pesados/análise , Metais Pesados/toxicidade , Nitratos/toxicidade , Nitrato de Prata , Solo , Poluentes do Solo/toxicidade
9.
Braz J Med Biol Res ; 54(2): e10466, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33439935

RESUMO

Preoperative evaluation in elective surgeries has been associated with successful surgical treatment. However, there is no solid scientific evidence that screening for coronary artery disease (CAD) reduces surgical risk. The aims of this study were to describe the frequency of inappropriate investigation of obstructive CAD induced by pre-anesthetic assessment in individuals without cardiovascular symptoms (candidates for low- to intermediate-risk surgeries) and to evaluate predictors of this conduct. We performed a retrospective evaluation of medical records of anesthesiology services from patients undergoing pre-anesthesia assessment between May 2015 and May 2016, including those with functional capacity ≥4 metabolic equivalents without a diagnosis of heart disease. A total of 778 medical records (47±16 years of age, 62.6% female) were studied. A private hospital performed 50.1% of the surgeries and 60.4% were of intermediate risk. Only 2.7% (95%CI: 1.7-4.1%) were screened for CAD, and 91% of these requests were mediated by cardiology consultations performed during pre-anesthetic testing visits. Factors associated with screening for CAD were hypertension, diabetes, moderate systemic disease (ASA III), cardiac consultation, previous diagnosis of CAD, and admission to a private hospital. Independent predictors were private hospitals (OR: 3.9; 95%CI: 1.3-11.0), ASA III (OR: 5.3; 95%CI: 1.7-16.2), and hypertension (OR: 3.8; 95%CI: 1.5-9.8). The frequency of inappropriate requests for CAD screening in asymptomatic individuals without untreated systemic diseases was low in pre-anesthetic visits. Although infrequent, screening for CAD is more common in the private setting, in patients with poorer health status, and is usually prescribed during cardiology consultation.


Assuntos
Anestesia , Doença da Artéria Coronariana , Procedimentos Desnecessários , Adulto , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/cirurgia , Feminino , Cardiopatias , Humanos , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Estudos Retrospectivos , Medição de Risco , Fatores de Risco
10.
Braz. j. med. biol. res ; 54(2): e10466, 2021. tab
Artigo em Inglês | LILACS | ID: biblio-1153513

RESUMO

Preoperative evaluation in elective surgeries has been associated with successful surgical treatment. However, there is no solid scientific evidence that screening for coronary artery disease (CAD) reduces surgical risk. The aims of this study were to describe the frequency of inappropriate investigation of obstructive CAD induced by pre-anesthetic assessment in individuals without cardiovascular symptoms (candidates for low- to intermediate-risk surgeries) and to evaluate predictors of this conduct. We performed a retrospective evaluation of medical records of anesthesiology services from patients undergoing pre-anesthesia assessment between May 2015 and May 2016, including those with functional capacity ≥4 metabolic equivalents without a diagnosis of heart disease. A total of 778 medical records (47±16 years of age, 62.6% female) were studied. A private hospital performed 50.1% of the surgeries and 60.4% were of intermediate risk. Only 2.7% (95%CI: 1.7-4.1%) were screened for CAD, and 91% of these requests were mediated by cardiology consultations performed during pre-anesthetic testing visits. Factors associated with screening for CAD were hypertension, diabetes, moderate systemic disease (ASA III), cardiac consultation, previous diagnosis of CAD, and admission to a private hospital. Independent predictors were private hospitals (OR: 3.9; 95%CI: 1.3-11.0), ASA III (OR: 5.3; 95%CI: 1.7-16.2), and hypertension (OR: 3.8; 95%CI: 1.5-9.8). The frequency of inappropriate requests for CAD screening in asymptomatic individuals without untreated systemic diseases was low in pre-anesthetic visits. Although infrequent, screening for CAD is more common in the private setting, in patients with poorer health status, and is usually prescribed during cardiology consultation.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Doença da Artéria Coronariana/cirurgia , Doença da Artéria Coronariana/diagnóstico , Procedimentos Desnecessários , Anestesia , Programas de Rastreamento , Estudos Retrospectivos , Fatores de Risco , Medição de Risco , Cardiopatias
12.
Carbohydr Res ; 493: 108035, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32497942

RESUMO

Nanocrystalline chitosan (NCC) is a modified form of chitosan, prepared from the method for obtaining chitosan acetate (CA). Due to the greater crystallinity of chitosan nanoparticles in relation to CA, NCC is more thermally stable and thus has great potential in the development of a new generation of biomaterials potentially useful in regenerative medicine and tissue engineering. NCC is also characterized by having similar properties to its precursor chitosan, such as its biocompatibility, bioactivity, ability to be bioabsorbed and lack of toxicity. One of the major problems associated with obtaining NCC is the low productivity of the methods. While known methods of obtaining nanostructures produce small amounts (milligrams), the method of synthesis for creating NCC from its salt is often more productive and less costly, and is patented by the authors of this work (registration number: BR10201702272). Thus, the objective of this study was to characterize NCC obtained through this innovative method, and analyze its chemical and physical properties using Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and mechanical property analysis with the mean values for the elasticity module, the resistance to tensile strength and the tensile strength. The results indicate that this new process of obtaining the NCC did not modify the chemical structure of the chitosan. The structure of the film surface created was homogeneous and the mechanical properties emphasized the plastifying effect of glycerol under NCC. The thermogravimetric analysis of NCC indicated greater stability in the polysaccharide structure of the nanocrystalline, due to an increased crystalline region compared to the CA which was confirmed by DSC.


Assuntos
Quitosana/química , Nanopartículas/química , Configuração de Carboidratos , Cristalização , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Resistência à Tração
14.
Arq. bras. med. vet. zootec. (Online) ; 71(4): 1269-1276, jul.-ago. 2019. ilus
Artigo em Português | LILACS, VETINDEX | ID: biblio-1038603

RESUMO

Objetivou-se descrever comparativamente as artérias responsáveis pela irrigação dos lobos tímicos cervicais e torácicos dos javalis, determinando-se também as características morfológicas do referido órgão nessa espécie, a ponto de correlacioná-las evolutivamente com os demais representantes da família Suidae. Os lobos tímicos cervicais direito e esquerdo receberam ramos distribuídos pelas artérias carótidas comuns direita e esquerda e cervicais superficiais direita e esquerda e, por vezes, pelas artérias torácica externa esquerda e subclávia esquerda. Essa característica vascular foi mantida ao longo da evolução, estando presente em linhagens e raças mais recentes de suídeos. A irrigação dos lobos tímicos torácicos direito e esquerdo foi realizada predominantemente por ramos diretos e indiretos ipsilaterais e contralaterais das artérias torácicas internas direita e esquerda, e também por ramos da artéria subclávia esquerda. Ramos diretos das artérias cervicais superficiais direita e esquerda e ramos diretos da artéria torácica interna direita foram encontrados para o lobo tímico médio, sendo essa uma descrição única nessa espécie, o que demonstra uma característica evolutiva primitiva nesse ancestral.(AU)


The objective of this study was to comparatively describe the arteries responsible for the irrigation of the cervical and thoracic thymus lobes of Boars, also determining the morphological characteristics of this body in this species to the point of evolutionarily correlating them with other representatives of the Suidae family. The left and right cervical thymic lobes received branches distributed by common right and left, superficial right and left carotid arteries, and neck and, sometimes, the outer left chest and left subclavian arteries. This feature was vascular maintained throughout evolution and is present in more recent strains and breeds of swine. Irrigation of the right and left thoracic thymic lobes was performed predominantly by direct and indirect ipsilateral and contralateral branches of the right and left internal thoracic arteries and also by branches of the left subclavian artery. Direct branches of the right and left superficial cervical artery and right branches of the right internal thoracic artery were found for the average thymic lobe, this being a unique description in this species, demonstrating a primitive feature in this evolutionary ancestor.(AU)


Assuntos
Animais , Timo/crescimento & desenvolvimento , Timo/irrigação sanguínea , Artérias Carótidas , Sus scrofa/anatomia & histologia
15.
Arq. bras. med. vet. zootec. (Online) ; 71(4): 1149-1157, jul.-ago. 2019. tab, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1038607

RESUMO

This work aimed to describe the origin, distribution, and ramifications of the ischiadicus nerve in the giant anteater and to provide anatomical data which could explain not only the evolutionary aspects but also provide important information for other related works. For the present study, four specimens were used, prepared by perfusion of 10% formaldehyde solution via the femoral artery, for conservation and dissection. The origin of the right and left ischiadicus nerves in the giant anteater from the ventral ramification of the third lumbar (L3) and the first (S1), second (S2), and third (S3) sacral spinal nerves. These nerves were symmetrical in all animals studied. The distribution and ramification occurred to the superficial, middle, and deep gluteal, gemelli, piriform, quadratus femoris, tensor fasciae latae, caudal crural abductor, cranial and caudal parts of the biceps femoris, adductor, semitendinous, and cranial and caudal parts of the semimembranous muscles. Based on the origins of the ischiadicus nerves, there is a caudal migration in the nerve location in animals in a more recent position on the evolutionary scale due to reconfiguration of the lumbosacral plexus, resulting from the increase in a number of lumbar vertebrae. There is no complete homology of the muscle innervation.(AU)


Objetivou-se descrever as origens, distribuições e ramificações dos nervos isquiáticos no tamanduá-bandeira, disponibilizando, assim, dados anatômicos que possam não só elucidar os aspectos evolutivos como também fornecer informações importantes para áreas afins. Foram utilizados quatro espécimes preparados por meio da perfusão de formaldeído 10% via artéria femoral, para conservação e dissecação. As origens dos nervos isquiáticos direito e esquerdo no tamanduá-bandeira foram provenientes dos ramos ventrais dos nervos espinhais lombares três e sacrais um, dois e três, sendo simétricos em todos os animais estudados. As distribuições e ramificações ocorreram nos músculos glúteos superficial, médio e profundo; gêmeo; piriforme; quadrado femoral; tensor da fáscia lata; abdutor crural caudal; bíceps femoral parte cranial; bíceps femoral parte caudal; adutor; semitendíneo; semimembranáceo parte cranial e semimembranáceo parte caudal. Notou-se que houve uma migração caudal na localização deste nervo nos animais mais recentes na escala evolutiva, devido a uma reconfiguração do plexo lombossacral decorrente do aumento no número de vértebras lombares, não havendo uma homologia total quanto à inervação dos músculos.(AU)


Assuntos
Animais , Nervo Isquiático/anatomia & histologia , Nervo Isquiático/irrigação sanguínea , Xenarthra/anatomia & histologia
16.
Nutrire Rev. Soc. Bras. Aliment. Nutr ; 42: 1-6, Dec. 2017. ilus, tab
Artigo em Inglês | LILACS | ID: biblio-880872

RESUMO

BACKGROUND: Chronic hepatitis C causes chronic hepatic inflammation, which can lead to cirrhosis, terminal liver failure, and hepatocellular carcinoma. The treatment aims to achieve viral clearance, but the usage of pegylated interferon and ribavirin is linked to side effects such as severe weight loss, which can lead to complications and treatment discontinuation. The aim of this study was to investigate which anthropometric measures were more affected in patients with chronic hepatitis C during 24 weeks of treatment with pegy lated interferon and ribavirin. Then, the influence of age, sex, hepatic fibrosis stage, and ribavirin doses on each measure was also evaluated. METHODS: Seventy-six patients were included and their weight, triceps skin fold thickness, arm circumference, middle-arm muscle circumference, and corrected arm muscle area were measured before and after 24 weeks of treatment. Epidemiological data and liver biopsy findings were obtained from patients' records. The sample was divided into two groups: one with advanced hepatic fibrosis and another group with mild to moderate fibrosis. Comparisons into each group were made using Wilcoxon or paired tests. After that, a linear regression model was applied to estimate the anthropometric changes during the treatment according to age, sex, hepatic fibrosis stage, and ribavirin doses. RESULTS: The subjects suffered reductions of important anthropometric measures, mainly related to fat mass (p<0.001).Some decrease of fat-free mass was also observed in subjects with advanced fibrosis. The statistic model showed that age and sex were more associated with the anthropometric changes observed. CONCLUSIONS: In conclusion, the antiviral treatment caused loss of relevant anthropometric measures, and the model proposed was able to estimate some of them


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Hepatite C/tratamento farmacológico , Interferons/efeitos adversos , Interferons/uso terapêutico , Ribavirina/efeitos adversos , Ribavirina/uso terapêutico , Redução de Peso/efeitos dos fármacos , Antropometria
17.
Mater Sci Eng C Mater Biol Appl ; 81: 148-155, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28887959

RESUMO

The lack of intrinsic open porosity in calcium phosphate cements slows down the resorption rate and bone ingrowth when implanted In Vivo. In this study, macroporous structures were obtained by mixing α-TCP cement with a foamed liquid phase containing different concentrations of sodium hydrogen phosphate and a nonionic surfactant. The cement paste was prepared by hand mixing in a novel system of two syringes connected by a tube. Two different liquid to powder (L/P) ratios were used to prepare the cement paste. The cement samples showed open macropores with diameters>100µm. The specimens prepared with lower L/P ratio showed smaller porosity, macroporosity and pore size distribution. The cohesion of the cement paste in liquid solutions was assessed by adding 2wt% sodium alginate to the liquid phase. This study suggests that the final macrostructure of the foamed cements can be controlled by varying the phosphate and surfactant concentrations in the liquid phase and the L/P ratio.


Assuntos
Tensoativos/química , Cimentos Ósseos , Fosfatos de Cálcio , Teste de Materiais , Fosfatos , Porosidade , Pós , Seringas
18.
Mater Sci Eng C Mater Biol Appl ; 77: 874-882, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28532104

RESUMO

In this work, a biomimetic synthesis reaction for the production of hydroxyapatite (HA)/natural rubber (NR) composites is presented. HA was synthesized in the presence of solubilized NR in tetrahydrofuran (THF), which permits that negatively charged domains in proteins and lipids in NR work as nucleation sites for hydroxyapatite. The mechanical and physicochemical properties of composites containing 10, 20 and 30wt% HA were studied. NR influenced HA crystallite morphology, shape and size and was able to disperse the HA particles in THF. The dispersion of HA in the composites promoted the enhancement of mechanical properties and loss of solubility of composites, which is believed to be macroscopic manifestations of the physical adsorption of NR to HA particles, known as the bound rubber phenomenon. Preliminary cell studies indicated that HepG2 cells presented viabilities ranging from 71.6 to 91.3%, with cell proliferation positively influenced by HA content at shorter culture times. The good dispersion of HA in the composites is expected to improve NR bioactivity and direct its use towards bone applications.


Assuntos
Borracha/química , Osso e Ossos , Durapatita , Humanos , Teste de Materiais
19.
Genet Mol Res ; 16(2)2017 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-28437557

RESUMO

In this study, we evaluated the fungicide effect on the incidence of rot grains and expression of catalase (CAT), alcohol dehydrogenase (ADH), and malate dehydrogenase (MDH) enzymes in commercial maize hybrids grown with conventional and reduced spacing in Guarapuava, PR, Brazil. The experiment was designed in random blocks with a 3 × 8-factorial scheme, totaling 24 treatments. The first factor constituted three levels, the first with foliar fungicide application [150.0 g/L trifloxystrobin (15.0%, w/v) + 175.0 g/L prothioconazole (17.5%, w/v)] at a dose of 0.4 L/ha at V8-stage eight expanded leaves and the second with an application of 0.5 L/ha at VT-tasseling and check (no fungicide application) stage. The second factor comprised eight maize hybrids that were divided into two groups, complex (AG 9045PRO, AG 8041PRO, DKB245PRO2, and 2B707PW) and susceptible (P 32R48H, DKB390PRO, P 30F53H, and P 30R50H), according to their reaction to the causative fungus, totaling 72 plots at each site in the crop of 2013/2014. The percentage of rot grains and the expression of CAT, ADH, and MDH were evaluated for each hybrid. The percentage of rot grains was influenced by the hybrid and fungicide used. The (trifloxystrobin + prothioconazole) reduced the incidence of rot grains, with relatively higher reduction in the hybrids considered susceptible. The higher expression of CAT enzyme was related to the higher incidence of rot grains because of grain deterioration, depending on the hybrids evaluated. A higher expression of ADH and MDH enzymes was observed in the maize hybrids belonging to the group considered tolerant.


Assuntos
Álcool Desidrogenase/genética , Antifúngicos/farmacologia , Catalase/genética , Malato Desidrogenase/genética , Proteínas de Plantas/genética , Zea mays/efeitos dos fármacos , Acetatos/farmacologia , Álcool Desidrogenase/metabolismo , Catalase/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Iminas/farmacologia , Malato Desidrogenase/metabolismo , Metacrilatos/farmacologia , Proteínas de Plantas/metabolismo , Sementes/efeitos dos fármacos , Sementes/enzimologia , Sementes/genética , Sementes/microbiologia , Estrobilurinas , Triazóis/farmacologia , Zea mays/enzimologia , Zea mays/genética , Zea mays/microbiologia
20.
Int J Oral Maxillofac Surg ; 46(7): 851-856, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28372991

RESUMO

Recurrent mandibular dislocation is a rare condition that can have a negative impact on quality of life. Different surgical techniques are employed in the treatment of this condition, and the demand for maximum healthcare quality has contributed to the implementation of evidence-based clinical practice. The objective of this study was to determine the level of scientific evidence in articles reporting open surgical treatment for recurrent mandibular dislocation. A comprehensive search strategy was conducted to locate relevant articles in the PubMed and Web of Science databases on open surgical treatment for recurrent mandibular dislocation published between January 1974 and August 2014. These were classified into one of the five established levels/sublevels of evidence: the level of evidence was determined based on the classification proposed by the Oxford Centre for Evidence-Based Medicine. One hundred and fourteen articles were identified, 91 of which were excluded based on the eligibility criteria. Thus, 23 articles were selected for inclusion in the review. All of the selected articles were rated as level 4 (low quality) regarding the level of evidence. The present review revealed that articles on open surgical treatment for recurrent mandibular dislocation exhibit a low level of scientific evidence. Thus, further studies on this topic with greater methodological rigour are needed.


Assuntos
Luxações Articulares/cirurgia , Transtornos da Articulação Temporomandibular/cirurgia , Humanos , Qualidade de Vida , Recidiva
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