RESUMO
AIMS: Penicillium digitatum, Alternaria alternata and Colletotrichum gloeosporioides are pathogens responsible for large decays and production losses of citrus. They are commonly controlled by fungicides, whose excessive applications have led to the emergence of resistant P. digitatum strains. Alternative approaches are imperative for sustainable and environmental harmless citrus production, being biological control a promising strategy. The objective was to evaluate the potential of Trichoderma strains native from the rhizosphere of citrus trees to control these pathogens. METHODS AND RESULTS: Seven strains were isolated and identified as Trichoderma harzianum, T. guizhouense, T. atroviride and T. koningiopsis through morphological and molecular analyses. Five of them showed effective antagonist performance in vitro against the pathogens. The strain T. harzianum IC-30 was the best biological control agent in vivo, obtaining a reduction of rot percentage around 80% after 3 weeks of infection of oranges with P. digitatum A21 (resistant to pyrimethanil). This strain also showed the highest chitinase and glucanase activities. CONCLUSIONS: Trichoderma harzianum IC-30 is an optimal antagonist for the control of green mould spreading and other pathogens in post-harvest citrus fruits. SIGNIFICANCE AND IMPACT OF THE STUDY: The strain combined with supplementary practices could lead to sustainable management of citrus fungal diseases, dispensing with synthetic fungicides.
Assuntos
Citrus sinensis/microbiologia , Farmacorresistência Fúngica , Fungicidas Industriais/farmacologia , Doenças das Plantas/prevenção & controle , Trichoderma/fisiologia , Antibiose , Fungos/efeitos dos fármacos , Fungos/patogenicidade , Controle Biológico de Vetores , Doenças das Plantas/microbiologia , Pirimidinas/farmacologia , RizosferaRESUMO
Magnetic systems with competing anisotropies generally exhibit asymmetry between the maximum amplitudes of the right and left maxima in a magnetoimpedance curve. Small errors in positioning the samples at the experimental setup may also produce such asymmetry. In this work, we present a study on the sources of the asymmetry between magnetoimpedance peaks in systems that present the exchange bias phenomenon, by comparing a phenomenological model to experimental data. A set of samples with different repetitions of the NiFe/FeMn exchange-biased bilayer was used in this study. From the frequency evolution of the asymmetry, together with magnetization curves, we were able to identify the sources for the observed magnetoimpedance asymmetry found on our experimental data.
RESUMO
The development of new electroluminescence polymers for specific colour tuning in Polymer Light Emitting Devices (PLEDs) is currently one of the most important fields for organic electronics. This work reports a synthesis of a new electroluminescent polymer and the concomitant test as PLED emissive layer. The polymer, synthesised from fluorene, is poly(9,9'-n-dihexil-2,7-fluorenodiilvinylene-alt-2,5thiophene) or PFT. The luminescence shows large bands with maxima around 480 nm in absorption and 560 nm in emission. The device was made in a three layer structure, with PEDOT:PSS as hole transport layer, PFT as emissive layer and butyl-PBD as electron transport layer. The electroluminescence spectrum shows a strong band peaked at 540 nm. For an applied voltage of 12 Volt, the brightness at normal angle of viewing is near 10 cd/m2 and the luminous efficiency is of 0.01 lm/W. A discussion about carrier transport and the electroluminescence properties is made.
RESUMO
Cryostat sections of clinicopathologically characterized breast cancer tissues were eluted with phosphate-buffered 0.9% sodium chloride solution, pH 7.2. The proteins were then characterized by polyacrylamide gel electrophoresis with and without prior treatment with sodium dodecyl sulfate. Approximately 65% of the brease cancer tissue eluates contained a prominent protein fraction with a molecular weight of 47,000 to 55,000 (p50). No such component was found in 15 of 17 eluates of benign breast tissue. Charge density studies disclosed that the p50 component included three populations of proteins that could be characterized according to the migration relative to gp55 derived from RIII murine mammary tumor virus, namely, fast (F-p50), intermediate (I-p50), and slow (S-p50). Prognostically favorable pathological characteristics, i.e., stage, nuclear grade, and lymphoreticuloendothelial responses, were proportionately most frequently found among S-p50 bbreast cancers and were least frequently found among F-p50 breast cancers. It appears that the S-p50 component acts in vivo as a prognostically significant immunogen. Further knowledge of the relationship between protein characteristics and clinicopathological features of human breast cancers would contribute to our understanding of mammary carcinogenesis and biological behavior.
Assuntos
Neoplasias da Mama/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias da Mama/patologia , Densitometria , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Vírus do Tumor Mamário do Camundongo/metabolismo , Peso Molecular , Proteínas de Neoplasias/isolamento & purificação , Proteínas Virais/metabolismoRESUMO
We studied the amino acid and lipid dynamics during embryogenesis of Homarus gammarus. Major essential amino acids (EAA) in the last stage of embryonic development were arginine, lysine and leucine; major nonessential amino acids (NEAA) were glutamic acid, aspartic acid, valine and glycine. The highest percent of utilization occurred in respect to EAA (27.8%), mainly due to a significant decrease (p<0.05) of methionine (38.3%) and threonine (36.0%). NEAA also decreased significantly (p<0.05, 11.4%), namely serine (38.1%), tyrosine (26.4%) and glutamic acid (25.7%). In contrast, the free amino acid content increased significantly (p<0.05) during embryonic development, especially the free nonessential amino acids (FNEAA). In the last stage, the most abundant FNEAA were glycine, proline, alanine and taurine, and the major free essential amino acids (FEAA) were arginine, lysine and leucine. Lipid content decreased significantly (p<0.05) during embryonic development. A substantial decrease in all neutral lipid classes was observed (>80% of utilization). Major fatty acids were 16:0, 18:0, 18:1n-9, 18:2n-6, 18:3n-3, 20:5n-3 and 22:6n-3. Unsaturated (UFA) and saturated fatty acids (SFA) were used up at similar rates (76.5% and 76.3%, respectively). Within UFA, monounsaturates (MUFA) were consumed more than polyunsaturates (PUFA) (82.9% and 67.5%, respectively).
Assuntos
Aminoácidos/metabolismo , Desenvolvimento Embrionário , Metabolismo dos Lipídeos , Nephropidae/embriologia , Nephropidae/metabolismo , Aminoácidos/análise , Animais , Ácidos Graxos/análise , Ácidos Graxos/química , Feminino , Lipídeos/análise , Lipídeos/classificação , Óvulo/química , Óvulo/crescimento & desenvolvimento , Água/análiseRESUMO
Previous studies have shown that Biomphalaria glabrata contains a complete cellulolytic system which includes an endoglucanase, an exoglucanase and a beta-glucosidase. In the present report, a scheme for the purification of the endoglucanase from this invertebrate is proposed. Two major problems were encountered during the study: 1) the presence of a green-brownish pigment, which could not be eliminated by thermal shock or ammonium sulfate precipitation and 2) relative instability of enzymatic activity. Various alternatives were tested and the best sequence of steps was: 1) a sample of the crude extract, obtained by homogenization of the digestive glands in 50 mM Tris-HCl buffer, pH 8.4, and ultracentrifugation, was applied to a Q-Sepharose FPLC column (50 mM Tris-HCl buffer, pH 8.4; 10 mm x 22.2 cm column; flow rate 1.5 ml/min; 0.1 to 0.5 M NaCl gradient); 2) the eluate peak containing activity was dialyzed, lyophilized and eluted from a Superdex-75 gel filtration FPLC column (50 mM ammonium acetate buffer, pH 4.8; 16 mm x 60 cm column; flow rate 1.0 ml/min). A low degree of purification (about 36-fold) and recovery (about 12%) were observed, probably due to enzyme instability. SDS-electrophoresis of the active fraction showed a major peak of 30 kDa. In order to improve the purification scheme, further studies are required to stabilize this enzyme during purification and storage.
Assuntos
Biomphalaria/enzimologia , Glicosídeo Hidrolases/isolamento & purificação , Animais , Cromatografia em Agarose , Glicosídeo Hidrolases/metabolismo , Concentração de Íons de Hidrogênio , Peso Molecular , UltracentrifugaçãoRESUMO
Synthesis and physico-chemical properties of 3-(4-bromobenzyl)-, 3-(4-chlorobenzyl)-5-arylidene-thiazolidine-2,4-diones and 3-(4-chlorobenzyl)-4-thioxo-5-arylidene-thiazolidin-2- ones are described. Twelve new products were synthesized by the aldolisation-crotonisation reaction from aromatic aldehydes and N-alkylated thiazolidinediones or thioxothiazolidinones. Seven compounds were preliminary tested for their bacteriostatic activity.
Assuntos
Antibacterianos/síntese química , Tiazóis/síntese química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Tiazóis/farmacologiaRESUMO
A new set of derivative thioxothiazolidinones and thioxoimidazolidinones 3,5-dissubstituted has been synthesized with satisfactory yield from the condensation Knoevenagel type between benzaldéhydes and 4-thioxothiazolidin-2-one, 2-thioxothiazolidin-4-one and 1-méthyl-2-thioxoimidazolidin-4-one compounds following by N-alkylation with aryl or acyl halides. The physico-chemical properties of the 5-benzylidene-3-[2-(4-chlorophenyl)-2-oxoethyl]-2 (or 4)-thioxothiazolidin-4 (or 2)-ones and 5-benzylidene-1-methyl-2-thioxoimidazolidin-4-ones synthesized have been described.
Assuntos
Imidazóis/química , Tiazóis/química , Tionas/química , Alquilação , Fenômenos Químicos , Físico-Química , Imidazóis/síntese química , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Tiazóis/síntese química , Tionas/síntese químicaRESUMO
Este trabalho teve como objetivo avaliar o efeito do treinamento sobre as variáveis da cinemática de equinos jovens da raça Brasileiro de Hipismo no salto em liberdade. Foram utilizados 14 equinos da raça Brasileiro de Hipismo com idade de 40 a 42 meses, peso vivo de 436,3±11,6kg e 448,2±12,7kg e altura na cernelha de 1,57±0,03m e 1,58±0,03m ao início e ao final do experimento, respectivamente. Os equinos realizaram dois protocolos de avaliação de salto, um antes e outro após o treinamento. O treinamento teve a duração de cinco meses e consistiu em 50 minutos de atividade física por dia, montados, sendo dois dias de flexionamento, dois dias de condicionamento físico e dois dias de trabalho específico de salto de obstáculos. Nos protocolos de avaliação, foram filmados cinco saltos em liberdade sobre um obstáculo oxer, com o primeiro e o segundo elemento na altura de 0,90m e 1,00m de altura, respectivamente, e 0,90m de largura. Foram fixados marcadores reflexivos nos equinos em pontos anatômicos utilizados como pontos de referência para a avaliação das características cinemáticas no salto. As filmagens foram realizadas com câmera de 100Hz, e as imagens, processadas no Simi Reality Motion Systems (r). Os resultados das variáveis avaliadas foram comparados com o teste de t pareado (P<0,05). O treinamento resultou no aumento das variáveis (P<0,05): velocidade da passada anterior ao salto, velocidade do salto, deslocamento horizontal da cernelha no salto, ângulo escapuloumeral, distância vertical entre as articulações escapuloumeral e metacarpofalângica, ângulo coxofemoral e ângulo femorotibial. No entanto, os valores dos ângulos umerorradial e tibiometatarsiano apresentaram redução após o treinamento (P>0,05). Conclui-se que o treinamento específico para salto com cinco meses de duração altera algumas variáveis cinemáticas dos equinos no salto de obstáculo proporcionando melhoria, principalmente, na trajetória do salto...
This study was carried out to evaluate the effect of training on the kinematic traits of young Brazilian Sport Horse in free jumping. 14 Brazilian Sport Horse were used, aged between 40 and 42 months, with body weight of 436.3±11.6kg and 448.2±12.7kg and height withers of 1.58±0.03m and 1.58±0.03m at the beginning and end of training, respectively. Two jumping evaluation protocols were used: before and after training. The training had the duration of five months and consisted of 50 minutes of exercise activities by day with a rider; two days of flexing, two days of physical conditioning and two days of specific jumping exercises. The evaluations were carried out, and five free jumps in each evaluation were record in an oxer, with the front fence of 0.90m and the back fence of 1.00m height and 0.90m of width. The horse's anatomical points were highlighted by reflective markers. The recordings were performed with 100Hz camera and the images processed in Simi Reality Motion Systems(r). The results were analyzed as paired data (P<0.05). The training increased the traits kinematics (P<0.05): last stride velocity speed prior to jumping, jumping velocity, horizontal withers displacement at jumping, scapulohumeral angle, vertical distance between scapulohumeral and metacarpophalangeal joint, coxofemoral angle and femorotibial angle. However, the kinematic traits reduced with training: humeroradial angle and tibiometatarsal angle (P<0.05). In conclusion, the jumping training with a five month duration changed some kinematic traits of free jumping in horses, especially the jumping trajectory...
Assuntos
Animais , Exercícios em Circuitos/veterinária , Fenômenos Biomecânicos/fisiologia , Cavalos , Equidae/anatomia & histologia , Atividade Motora , Esforço FísicoRESUMO
Bacterial invasiveness and immunological responses were studied in germfree (GF) and conventional (CV) mice infected with Salmonella typhimurium. Bacterial counts of homogenates prepared from liver and spleen showed that the colony forming units (CFU) increased rapidly in GF mice and reached lethal proportions (10(9) cell per organ) by day 6. In CV mice, these counts increased to about 10(4.5) log cell per organ by day 6 and then declined slowly. An increase in serotype-specific IgM and IgG levels was noted in CV mice with a maximum by day 2. Very low values of these IgM and IgG were observed in GF mice during the course of infection. Delayed type hypersensitivity (DTH) response as measured by footpad swelling was higher in CV animals. Higher hypersensitivity to LPS during infection in GF animals resulted in death of all the animals tested for DTH after day 2. The data obtained suggest that during a rapid invasive bacterial infection, the slow development of immune response of GF mice may result in death of these animals.
Assuntos
Vida Livre de Germes , Camundongos/imunologia , Salmonelose Animal/imunologia , Salmonella typhimurium/imunologia , Animais , Anticorpos Antibacterianos/biossíntese , Suscetibilidade a Doenças/imunologia , Hipersensibilidade Tardia/imunologia , Imunidade Inata , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Fígado/microbiologia , Tecido Linfoide/microbiologia , Camundongos/microbiologia , Salmonelose Animal/microbiologia , Salmonella typhimurium/isolamento & purificação , Fatores de TempoRESUMO
A study on presence of antibodies to Trichomonis vaginalis in serum was done on a group of 500 pregnant, asymptomatic Angolan women. A serologic screening, done by ELISA, revealed that 41% of the women had IgG and IgM against the parasite. Analysis of sera by immunoblotting revealed that 94.4% of sera with anti-T. vaginalis IgG class antibodies were reactive against a common immunogenic protein of 115 kDa. The common immunogen was identified as the protozoan alpha-actinin. All sera recognizing the 115-kDa antigen were reactive against both native and recombinant T. vaginalis alpha-actinin and nonreactive against human alpha-actinin. The findings presented in this work offer a new tool for epidemiologic studies and open new perspectives for vaccination.
Assuntos
Actinina/imunologia , Anticorpos Antiprotozoários/imunologia , Complicações Parasitárias na Gravidez/imunologia , Vaginite por Trichomonas/imunologia , Trichomonas vaginalis/imunologia , Actinina/genética , Animais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Western Blotting , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Gravidez , Complicações Parasitárias na Gravidez/parasitologia , Proteínas Recombinantes/imunologia , Vaginite por Trichomonas/parasitologiaRESUMO
Previous studies have shown that Biomphalaria glabrata contains a complete cellulolytic system which includes an endoglucanase, an exoglucanase and a ß-glucosidase. In the present report, a scheme for the purification of the endoglucanase from this invertebrate is proposed. Two major problems were encountered during the study: 1) the presence of a green-brownish pigment, which could not be eliminated by thermal shock or ammonium sulfate precipitation and 2) relative instability of enzymatic activity. Various alternatives were tested and the best sequence of steps was: 1) a sample of the crude extract, obtained by homogenization of the digestive glands in 50 mM Tris-HCl buffer, pH 8.4, and ultracentrifugation, was applied to a Q-Sepharose FPLC column (50 mM Tris-HCl buffer, pH 8.4; 10 mm x 22.2 cm column; flow rate 1.5 ml/min; 0.1 to 0.5 M NaCl gradient); 2) the eluate peak containing activity was dialyzed, lyophilized and eluted from a Superdex-75 gel filtration FPLC column (50 mM ammonium acetate buffer, pH 4.8; 16 mm x 60 cm column; flow rate 1.0 ml/min). A low degree of purification (about 36-fold) and recovery (about 12 percent) were observed, probably due to enzyme instability. SDS-electrophoresis of the active fraction showed a major peak of 30 kDa. In order to improve the purification scheme, further studies are required to stabilize this enzyme during purification and storage