1,774 research outputs found

    Brachiaria As A Cover Crop To Improve Phosphorus Use Efficiency In A No-till Oxisol

    Get PDF
    Oxidic soils are phosphorus drains in soil; hence, P availability is a limiting factor in tropical, weathered Oxidic soils. It has been shown that some brachiarias grown as cover crops may increase soil available P to subsequent crops. The objective of this study was to evaluate soil P cycling and availability, as well as the response of soybean to soluble and natural reactive phosphates as affected by ruzi grass (Urochloa ruziziensis, R. Germ. and C.M. Evrard, Crin) grown as a cover crop in a no-till system. Experimental treatments consisted of the presence or absence of ruzi grass in combination with a control (0.0 P) and soluble and reactive rock phosphate broadcast on the soil surface in the winter (80 kg ha-1 P2O2), plus three rates of P applied to soybean furrows (0, 30, and 60 kg ha-1 of P2O5) at planting, in the form of triple superphosphate. Soybean was cropped in two seasons: 2010/2011 and 2011/2012. Soil samples were taken before soybean planting (after desiccation of Brachiaria) at 0.00-0.05 and 0.05-0.10 m for soil available P. Total weight of dry matter and P accumulated in ruzi grass were determined, as well as soybean yields, P in soybean grains, and P use efficiency (PUE). The use of natural phosphate increased soil P availability. The highest yields were obtained with higher application rates of triple superphosphate in the planting furrow combined with broadcast rock phosphate. Broadcast application of Arad reactive phosphate increases and maintains soil available P, and this practice, associated with ruzi grass grown as a cover crop and the use of triple superphosphate applied to soybean furrows, results in higher use of P by soybeans. © 2016, Revista Brasileira de Ciencia do Solo. All rights reserved.4

    Bound states in disclinated graphene with Coulomb impurities in the presence of a uniform magnetic field

    Get PDF
    AbstractIn this contribution, we study the effects caused by an impurity on the quantum dynamics of massive excitations in a disclinated graphene in the presence of an external magnetic field. Within a continuum approach, the problem is mathematically modeled by the definition of a special vector potential containing all the information about the topology and the interacting fields. The presence of disclination is introduced by a term in the Dirac equation that translates the appearance of a phase associated with the transport of the spinor around the apex of the cone. We solve exactly the Dirac equation for this problem and the eigenvalues are obtained. We observe the influence of the disclination on the spectrum of energy and the allowed values of magnetic field

    Environmental Services Associated With The Reclamation Of Areas Degraded By Mining: Potential For Payments For Environmental Services

    Get PDF
    This paper discusses the potential of associating environmental services (ES) with techniques for reclaiming degraded areas (RDA) used in the mining sector, considering the current trends in payments for environmental services (PES) in Brazil. A literature review with content analysis generated results which identified the ES generated for eight cases of RDA in mining. As an example, ES related to soil enhancement were found. A more extended review of general RDA techniques confirmed the potential for associating other ES to RDA techniques used in mining, an example here is the enhancement of carbon stocks. Support for actions could come from existing PES schemes, particularly for cases where the ES identified as associated with an RDA technique are related to soil and water conservation. Concluding remarks indicate that there is a potential scenario for ES diversification in the reclamation stage of mining operations. A first step towards accomplishing this diversification envisages the creation of a PES scheme specific to the mining sector. Further studies are needed to develop criteria for fostering a PES scheme specifically for the reclamation phase of mining operations in Brazil.19213716

    Multihierarchical electrodes based on titanate nanotubes and zinc oxide nanorods for photoelectrochemical water splitting

    No full text
    Studies involving water splitting to form hydrogen and oxygen have attracted attention because H2 is considered the fuel of the future. Photoelectrocatalysts have been widely used for this application, and several metal oxides can be applied as catalysts. Among them, we highlight zinc oxide nanorods (ZnONRs) and titanate nanotubes (TiNTs); however, their individual nanostructures exhibit disadvantages. For example, ZnONR shows rapid recombination of the photogenerated charges, and TiNT gives rise to randomly orientated films; these disadvantages limit their application as photoanodes. In this study, for the first time, we present a new class of multihierarchical electrodes based on TiNT-decorated ZnONR films that exhibited superior results to the individual species. The TiNTs are homogenously dispersed over the surface of the rods without forming agglomerates, giving rise to a heterojunction that exhibits lower recombination rates. It was found that the results are better when the contents of TiNT in the electrode are higher; thus, glycine was successfully used as a bridge to link both of the structures, increasing the amount of TiNT decorating the rods. As a result, the photocurrent generated with these multihierarchical electrodes is higher than that obtained for pure ZnONR electrodes (0.9 mA and 0.45 mA, respectively), and the electrode potentials for O2 evolution is lower than that observed for pure TiNT electrodes (0 V and 0.8 V vs. ERHE, respectively). The IPCE values are also higher for the multihierarchical electrodes

    Tratamiento conservador del hallux valgus juvenil mediante ortesis nocturnas

    Get PDF
    Se presentan los resultados obtenidos con tratamiento conservador del hallux valgus juvenil con el uso de ortesis nocturnas confeccionadas a medida, con material termoplástico, en 18 pacientes con edades de 8 a 15 años (media: 12 años). El tiempo medio de tratamiento fue de 18 meses y los pacientes fueron seguidos después del tratamiento por igual período de tiempo. Debe destacarse el alto abandono del método que alcanzó la cifra del 44%. Fueron utilizados como parámetros de valoración de resultados las medidas radiográficas de los ángulos de valguismo del hallux (AVH) e intermetatarsiano l-II (AIM), obtenidas antes y después de terminado el período de observación. El valor medio inicial del AVH fue de 22° y al final fue de 20°. Las medidas de los valores del AIM fueron 11 y 10,7°, respectivamente. Ambas medidas no se diferencian entre sí desde el punto de vista estadístico, lo que lleva a concluir que el tratamiento utilizado no fue capaz de corregir las deformidades básicas del hallus valgus infantil, pero evita la progresión de esas deformidades.The results of conservative treatment of adolescent hallux valgus using custom made nocturnal splints in 18 patients ranging in age from 8 to 15 years (mean 12) are presented. The average period of treatment and follow-up was 18 months. There was a high rate (44%) of treatment abandon. As assessment parameters were used radiographic measures of the hallux valgus angle and the intermetatarsal I-II angle. Measures were obtained before treatment and at the end of follow-up. The initial mean valgus angle was 22° and the last mean value 20°. The mean valus of the intermetatarsal angle were respectively 11° and 10,7°. There were no significant statistical differences, indicating that the treatment of hallux valgus using nocturnal splintage do not correct the deformity but avoid its progression

    Correlation of mixed lymphocyte culture with chronic graft-versus-host disease following allogeneic stem cell transplantation

    Get PDF
    The purpose of the present study was to evaluate the mixed lymphocyte culture as a predictive assay of acute and chronic graft-versus-host disease (GVHD). We studied 153 patients who received a first bone marrow transplantation from human leukocyte antigen-identical siblings. Acute GVHD was observed in 26 of 128 (20.3%) patients evaluated and chronic GVHD occurred in 60 of 114 (52.6%). One-way mixed lymphocyte culture (MLC) assays were performed by the standard method. MLC results are reported as the relative response (RR) from donor against patient cells. The responses ranged from -47.0 to 40.7%, with a median of 0.5%. The Kaplan-Meier probability of developing GVHD was determined for patients with positive and negative MLC. There was no significant difference in incidence of acute GVHD between the groups studied. However, the incidence of chronic GVHD was higher in recipients with RR >4.5% than in those with RR 4.5%), 2.9 for those who received peripheral blood progenitor cells as a graft, and 2.2 for patients who developed previous acute GVHD. MLC was not useful for predicting acute GVHD, but MLC with RR >4.5% associated with other risk factors could predict the development of chronic GVHD, being of help for the prevention and/or treatment of this late complication.56757

    Monitoring Of Bcr-abl Levels In Chronic Myeloid Leukemia Patients Treated With Imatinib In The Chronic Phase - The Importance Of A Major Molecular Response

    Get PDF
    Background: Real time PCR has become the most common technique to monitor BCR-ABL transcript levels of patients treated with kinase inhibitors. The aim of this study was to evaluate BCR-ABL levels of chronic myeloid leukemia patients treated with imatinib in the chronic phase and correlate the response to therapy and event-free survival. Methods: BCR-ABL levels were measured in peripheral blood cell samples using Real time PCR at diagnosis and then every 3 months after starting therapy with imatinib. Major molecular response was defined as a three-log reduction from the standardized baseline value. Major molecular response values were adjusted to international scale using a conversion factor of 1.19. The results are reported as a BCR-ABL/ABL ratio (%). Results: Hematological, major cytogenetic and complete cytogenetic responses were achieved by 57 (95%), 45 (75%) and 38 (63%) patients, respectively. Twenty-four out of sixty patients achieved a major molecular response (40%) in a median time of 8.5 months. Overall survival and event free survival were higher for patients with (100%) versus patients without (77%) a complete cytogenetic response (p-value = 0.01) at 48 months. Patients with complete cytogenetic response and major molecular response had a higher event free survival compared to patients with complete cytogenetic response but without major molecular response (p-value = 0.007). Conclusion: In conclusion, the prognostic impact of achieving complete cytogenetic response and a major molecular response and also the importance of molecular monitoring in the follow-up of chronic myeloid leukemia patients were demonstrated.333211215Melo, J.V., The molecular biology of chronic myeloid leukaemia (1996) Leukemia, 10 (5), pp. 751-756Wang, L., Pearson, K., Pillitteri, L., Ferguson, J.E., Clark, R.E., Serial monitoring of BCR-ABL by peripheral blood real-time polymerase chain reaction predicts the marrow cytogenetic response to imatinib mesylate in chronic myeloid leukaemia (2002) Br J Haematol, 118 (3), pp. 771-777Muller, M.C., Gattermann, N., Lahaye, T., Deininger, M.W., Berndt, A., Fruehauf, S., Dynamics of BCR-ABL mRNA expression in firstline therapy of chronic myelogenous leukemia patients with imatinib or interferon alpha/ara-C (2003) Leukemia, 17 (12), pp. 2392-2400Branford, S., Hughes, T.P., Rudzki, Z., Monitoring chronic myeloid leukaemia therapy by real-time quantitative PCR in blood is a reliable alternative to bone marrow cytogenetics (1999) Br J Haematol, 107 (3), pp. 587-599Radich, J.P., Gooley, T., Bryant, E., Chauncey, T., Clift, R., Beppu, L., The significance of bcr-abl molecular detection in chronic myeloid leukemia patients late, 18 months or more after transplantation (2001) Blood, 98 (6), pp. 1701-1707Hughes, T.P., Kaeda, J., Branford, S., Rudzki, Z., Hochhaus, A., Hensley, M.L., Frequency of major molecular responses to imatinib or interferon-alpha plus cytarabine in newly diagnosed chronic myeloid leukemia (2003) N Engl J Med, 349 (15), pp. 1423-1432Press, R.D., Love, Z., Tronnes, A.A., Yang, R., Tran, T., Mongoue- tchokote, S., BCR-ABL mRNA levels at and after the time of a complete cytogenetic response predict the duration of CCR in imatinib mesylate-treated patients with CML (2006) Blood, 107 (11), pp. 4250-4256Cortes, J., Talpaz, M., O'Brien, S., Jones, D., Luthra, R., Shan, J., Molecular responses in patients with chronic myelogenous leukemia in chronic phase treated with imatinib mesylate (2005) Clin Cancer Res, 11 (9), pp. 3425-3432Iacobucci, I., Saglio, G., Rosti, G., Testoni, N., Pane, F., Amabile, M., Achieving a major molecular response at the time of a complete cytogenetic response (CCgR) predicts a better duration of CCgR in imatinib-treated chronic myeloid leukemia patients (2006) Clin Cancer Res, 12 (10), pp. 3037-3042Baccarani, M., Saglio, G., Goldman, J., Hochhaus, A., Simonsson, B., Appelbaum, F., Evolving concepts in the management of chronic myeloid leukemia: Recommendations from an expert panel on behalf of the European LeukemiaNet (2006) Blood, 108 (6), pp. 1809-1820Hughes, T., Deininger, M., Hochhaus, A., Branford, S., Radich, J., Kaeda, J., Monitoring CML patients responding to treatment with tyrosine kinase inhibitors: Review and recommendations for harmonizing current methodology for detecting BCR-ABL transcripts and kinase domain mutations and for expressing results (2006) Blood, 108 (1), pp. 28-37Branford, S., Cross, N.C., Hochhaus, A., Radich, J., Saglio, G., Kaeda, J., Rationale for the recommendations for harmonizing current methodology for detecting BCR-ABL transcripts in patients with chronic myeloid leukaemia (2006) Leukemia, 20 (11), pp. 1925-1930Cortes, J., Baccarani, M., Fea, G., (2008) A Phase III, Randomized, Openlabel Study of 400 Mg Versus 800 Mg of Imatinib Mesylate (IM) in Patients With Newly Diagnosed, Previously Untreated Chronic Myeloid Leukemia in Chronic Phase (CML-CP), Using Molecular Endpoints: One Year Results of TOPS (Tyrosine Kinase Inhibitor Optimization and Selectivity) Study, , 50th ASH Annual Meeting and Exposition Online program and Abstracts. San Francisco, CABranford, S., Fletcher, L., Cross, N.C., Muller, M.C., Hochhaus, A., Kim, D.W., Desirable performance characteristics for BCR-ABL measurement on an international reporting scale to allow consistent interpretation of individual patient response and comparison of response rates between clinical trials (2008) Blood, 112 (8), pp. 3330-3338O'Brien, S.G., Guilhot, F., Larson, R.A., Gathmann, I., Baccarani, M., Cervantes, F., Imatinib compared with interferon and lowdose cytarabine for newly diagnosed chronic-phase chronic myeloid leukemia (2003) N Engl J Med, 348 (11), pp. 994-1004Marin, D., Milojkovic, D., Olavarria, E., Khorashad, J.S., de Lavallade, H., Reid, A.G., European LeukemiaNet criteria for failure or suboptimal response reliably identify patients with CML in early chronic phase treated with imatinib whose eventual outcome is poor (2008) Blood, 112 (12), pp. 4437-444

    A utilização do ELISA empregando antígenos homólogos e heterólogos para a detecção de IgG e subclasses (IgG1 e IgG2) no diagnóstico de Leishmaniose visceral canina

    Get PDF
    Indirect immunofluorescence is the method recommended for the diagnosis of visceral leishmanisis in dogs, however, the accuracy of this technique is low and its use on a large scale is limited. Since ELISA does not present these limitations, this technique might be an option for the detection of IgG or specific IgG1 and IgG2 subclasses. Canine ehrlichiosis is an important differential diagnosis of American Visceral Leishmaniasis (AVL). The present study compared ELISA using Leishmania chagasi and Leishmania braziliensis antigen for the detection of anti-Leishmania IgG and subclasses in serum samples from 37 dogs naturally infected with L. chagasi (AVL) and in samples from four dogs co-infected with L. braziliensis and L. chagasi (CI). The occurrence of cross-reactivity was investigated in control serum samples of 17 healthy dogs (HC) and 35 infected with Ehrlichia canis (EC). The mean optical density obtained for the detection of IgG was significantly higher when L. chagasi antigen was used, and was also higher in subgroup VLs (symptomatic) compared to subgroup Vla (asymptomatic). The correlation between IgG and IgG1 was low. The present results suggest that IgG ELISA using homologous antigen yields the best results, permitting the diagnosis of asymptomatic L. chagasi infection and the discrimination between cases of AVL and ehrlichiosis in dogs.A imunofluorescência indireta é o método recomendado para o diagnóstico de leishmaniose visceral em cães, entretanto, a acurácia dessa técnica é baixa e seu uso em grande escala é limitado. Uma vez que o ELISA não apresenta essas limitações, essa técnica poderia ser uma opção para a detecção de IgG ou subclasses IgG1 e IgG2 específicas. A ehrlichiose canina é um importante diagnóstico diferencial de Leishmaniose Visceral Americana (LVA). O presente estudo comparou o ELISA usando antígenos de Leishmania chagasi e Leishmania braziliensis para a detecção de IgG e subclasses anti-Leishmania em amostras de soro de 37 cães naturalmente infectados com L. chagasi (LVA) e em amostras de quatro cães co-infectados (CI). A ocorrência de reatividade cruzada foi investigada em amostras de soro controle de 17 animais saudáveis (HC) e 35 de infectados por Ehrlichia canis (EC). A média de densidade óptica obtida para a detecção de IgG foi significantemente maior quando o antígeno de L. chagasi foi usado e também mais elevada no subgrupo LVs (sintomático) quando comparado ao subgrupo LVa (assintomático). A correlação entre IgG e IgG1 foi baixa. O presente resultado sugere que ELISA IgG empregando antígeno homólogo, produz os melhores resultados, permitindo o diagnóstico de infecção assintomática por L. chagasi e a discriminação entre casos de LVA e ehrlichiose em cães

    The availability of full match sibling donors and feasibility of allogeneic bone marrow transplantation in Brazil

    Get PDF
    The feasibility of allogeneic bone marrow transplantation (alloBMT) in a developing country has not yet been demonstrated. Many adverse factors including social and economic limitations may reduce the overall results of this complex and expensive procedure. Our objective was to characterize the most important clinical, social and economic features of candidates for transplantation and their potential donors as well as the influence of these factors on overall survival in a retrospective and exploratory analysis at a university hospital. From July 1993 to July 2001, candidates for BMT were referred to the Bone Marrow Transplantation Unit by Hematology and Oncology Centers from several regions of Brazil. A total of 1138 patients were referred to us as candidates for alloBMT. Median age was 25 years (range: 2 months-60 years), 684 (60.1%) were males and 454 (39.9%) were females. The clinical indications were severe aplastic anemia and hematological malignancies. From the total of 1138 patients, 923 had HLA-typing; 497/923 (53.8%) candidates had full match donors; 352/1138 (30.8%) were eligible for alloBMT. Only 235 of 352 (66.7%) were transplanted. Schooling was 1st to 8th grade for 123/235 (52.3%); monthly family income ranged from US60(760 (7%) to more than US400 (36%). Overall survival for patients with chronic myeloid leukemia, severe aplastic anemia and acute myeloid leukemia was 58, 60 and 30%, respectively. Thus, overall survival rates for the most frequent hematological diseases were similar to those reported in the International Registry, except for acute myeloid leukemia. This descriptive and exploratory analysis suggests the feasibility of alloBMT in a developing country like Brazil.31532
    corecore