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Phosphorus kinetics in calves experimentally submitted to a trickle infection with Cooperia punctata

LOUVANDINI, H.; RODRIGUES, R. R.; GENNARI, S. M.; MCMANUS, C. M.; VITTI, D. M. S. S.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
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46.24%
Ten male Holstein calves (74.3 +/- 3.2 kg LW) were used for a trial with trickle infection with Cooperia punctata to evaluate phosphorus (P) kinetics. Five calves were inoculated with 10,000 L(3) stage larvae per week during 35 days, while the other group of five calves was kept as a control. On the 29th day each calf was intravenously injected with 29.6 MBq of a (32)p solution. Blood samples were taken at 24 h periods for 7 days, after which all calves were slaughtered and worms burdens. Faeces, urine and tissue samples were taken for analysis using isotopic dilution and modeling techniques. The number of eggs per gram of faeces (EPG)was 1920 +/- 168 on 28th day and the total number of worms burdens was 11,131 +/- 1500. Infected calves showed lower feed intake and live weight gain, as well as lower P intake, absorption and retention than control calves. The P flows between body compartments were lower for blood to gastrointestinal tract (TGI), TGI to blood, blood to soft tissues, bone balance and soft tissue balance in infected calves when compared to the control. The trickle infection of C punctata affected P metabolism due to the decrease in P retained and live weight due to fall in feed intake. (C) 2009 Elsevier B.V. All rights reserved.; FAPESP[00/00640-0]; CNPq - Brazil

Estudo e desenvolvimento de fonte de fósforo-32 imobilizado em matriz polimérica para tratamento de câncer paravertebral e intracranial; Study and development of phosphorus-32 source immobilized in polymer matrix for paraspinal and intracranial cancer treatment

Benega, Marcos Antonio Gimenes
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 24/03/2015 PT
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As últimas estimativas da Organização Mundial da Saúde mostram a ocorrência de 14,1 milhões de novos casos de câncer em 2012. Sendo que desses casos, 8,2 milhões virão a óbito. Os tumores paravertebrais e intracraniais, também chamados de cânceres do Sistema Nervoso Central, tem origem no cérebro, nervos cranianos e meninges. Uma nova modalidade de braquiterapia começou a ser usada nesta última década. Neste procedimento, placas poliméricas flexíveis, carregando fósforo-32, são colocadas próximas ou em contato ao tumor para o tratamento. Este tratamento apresenta vantagens em relação aos demais porque aplica uma alta taxa de dose no tumor poupando tecidos sadios. A produção destas placas ainda é pouco estudada, embora já existam resultados satisfatórios no seu uso para o tratamento dos cânceres do sistema nervoso central. Neste trabalho foram realizados estudos iniciais para a produção deste tipo de placas poliméricas para braquiterapia. Foram avaliadas as propriedades mecânicas e a capacidade de imobilização de material radioativo de duas resinas comercias, uma poliuretânica e outra epoxídica, com e sem presença de substrato de policarbonato. Os testes iniciais apontaram o uso da resina epoxídica como melhor alternativa e com o uso dela foram feitos os primeiros protótipos e testes. O uso do policarbonato como substrato não foi necessário em uma das metodologias...

A model on biological flow of phosphorus in growing pigs

Lopes,J.B.; Moreira,J.A.; Kebreab,E.; Vitti,D.M.S.S.; Abdalla,A.L.; Crompton,L.A.; France,J.
Fonte: Universidade Federal de Minas Gerais, Escola de Veterinária Publicador: Universidade Federal de Minas Gerais, Escola de Veterinária
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2009 EN
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36.24%
Ten crossbred barrows weighting 20kg were allocated in five groups fed and on diets consisted of different total phosphorus (P) levels: 0.30%, 0.40%, 0.51%, 0.65%, and 0.73%. The animals were intravenously injected 7.4MBq of radioactive P (32P) and after seven days they were slaughtered for further analysis. The evaluated parameters were intake, excretion, specific activities, and flow of P in compartments (1-gut, 2-blood, 3-bone, and 4-soft tissue). Besides fecal losses, the kidneys played an import role in P regulation. The flows of P from tissue and gut to the blood were affected by P intake.

PHOSPHORUS METABOLISM AND ESTIMATION OF PHOSPHORUS REQUIREMENTS FOR SHEEP

LOUVANDINI,H; VITTI,D.M.S.S
Fonte: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz" Publicador: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/1996 EN
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The main objective of the present work was to determine the effects of different dietary phosphorus (P) levels on endogenous faecal loss and to estimate the minimum daily requirement of P for sheep. The study was conducted with 24 Suffolk sheep which received a basic diet consisting of hay-concentrate mixture. The treatments consisted of different amounts of bone meal, added to the basic diet, so as to obtain supplementary P levels of 0, 1, 2 and 3g/day. Twenty-one days after the introduction of the experimental diet, 7.4 MBq radioactive P (32P) was injected into the left jugular vein of each sheep and blood, faeces and urine samples were collected daily for 8 days at 24-hour intervals. The samples were analysed for inorganic P and for radioactive specific activities. Mean endogenous faecal losses of P were 19.00, 31.79, 39.35, and 38.06mg/kg live weight (LW) per day in sheep supplemented with 0, 1, 2, and 3g, respectively. A positive linear relationship was observed between endogenous faecal loss and consumed P, indicating that this loss was linked to dietary P. Total P excretion in the faeces, as well as P absorption, retention, urinary excretion and salivary secretion were also directly related to P intake, as part of the mechanism of homeostatic control of organism animal. The minimum endogenous faecal loss for zero P intake...

Effects of the Decay of Incorporated Radioactive Phosphorus on the Transfer of the Bacteriophage SP82G Genome 1

McAllister, William T.; Green, D. MacDonald
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1973 EN
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The last genetic markers to be transferred during bacteriophage SP82G infection have a higher sensitivity to the decay of incorporated radioactive phosphorous (32P) than those which are located on the proximal end of the genome. If 32P decay is permitted to take place after DNA transfer is complete (in frozen infective centers) and in the absence of DNA replication, no dependence of marker sensitivity on map position is observed. These results indicate that the decay of incorporated 32P leads to damages that prevent the efficient transfer of portions of the genome distal to the lesion. At 4 C, failure to transfer some portion of the genome occurs in 49% of all lethal events. Even though damages that prevent transfer of the genome are in themselves lethal, they do not prevent rescue of genetic markers on portions of the genome that are transferred. The portion of the genome that is transferred, is transferred at the same rate as an undamaged genome. We interpret these results to mean that double-strand breaks in the DNA are the lesions that prevent distal transfer and that single-strand breaks have little or no effect on the transfer of the bacteriophage SP82G genome.

Radioactive phosphorus uptake testing of choroidal lesions. A report of two false-negative tests.

Robertson, D M
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1976 EN
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36.15%
Two false-negative results from 32P testing for histologically verified malignant melanomas of the choroid are reported. In the first case, a haemorrhagic choroidal detachment caused an increase in probe; additionally, the tumour was necrotic. Both factors are likely to have contributed to the false-negative result. A satisfactory explanation for the false-negative result in the second case was not determined, although it may have accurately reflected a period of minimal tumour activity, inasmuch as repeat 32P testing was strongly positive eight months later, when unequivocal evidence of tumour growth was present. An alternative explanation is that the orally administered 32P was incompletely absorbed. Since 32P testing is frequently accompanied by significant manipulation both in the manoeuvre associated with tumour localization and in that associated with the actual radioactive counting, it would seem desirable to perform indicated enucleation immediately after completion of the 32P testing. While the properly performed 32P test remains a valuable diagnostic test for helping to establish the presence or absence of malignancies of the posterior globe, it is important to guard against the tendency to underestimate careful clinical evaluation.

DETERMINING THE SITE OF BRAIN TUMORS—The Use of Radioactive Iodine and Phosphorus

Amyes, Edwin W.; Deeb, Paul H.; Vogel, Philip J.; Adams, Ralph M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /03/1955 EN
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36.43%
By tests using radioactive iodine combined with diiodofluorescein, the site of tumors was correctly determined in 61 per cent of 39 cases of tumors of the cerebral hemispheres. In 19 cases where the focal radioactivity was increased 24 per cent or more over that of the surrounding area, there were no errors in localization. Fifteen patients with expanding intracranial lesions were tested at operation with radioactive phosphorus and 14 lesions were correctly localized. This procedure in which the needle probe was used was found of great value in rapidly locating and outlining the area of involvement.

THE PREPARATION AND USE OF TOBACCO MOSAIC VIRUS CONTAINING RADIOACTIVE PHOSPHORUS

Stanley, W. M.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/07/1942 EN
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46.72%
Normal and tobacco mosaic-diseased Turkish tobacco plants were grown in sand for a period of several weeks, during which they were fed daily a complete nutrient solution to which had been added disodium phosphate containing radioactive phosphorus. Determinations were made of the distribution of radioactive phosphorus in different fractions such as the wash from the sand and roots, the press cake obtained on pressing the juice from the plants, the protein and protein-free portions of the supernatant liquids obtained on ultracentrifugation of the juices, and the purified tobacco mosaic virus isolated from the diseased plants. Chemical analyses as well as radiographs of the normal and diseased leaves indicated that they contained the same amount of phosphorus. Approximately 30 per cent of the radioactive phosphorus absorbed by the diseased plants was found to be combined with the purified tobacco mosaic virus that was isolated from these plants. Following the inoculation of purified tobacco mosaic virus possessing high radioactivity to normal Turkish tobacco plants, most of the radioactivity was found to be associated with non-virus components of which about 40 per cent was in the inoculated and 60 per cent in the uninoculated portions of the plants. Although a small amount of radioactive virus was isolated from the uninoculated portions of the plants...

THE TURNOVER RATE OF PHOSPHOLIPIDS IN THE PLASMA OF THE DOG AS MEASURED WITH RADIOACTIVE PHOSPHORUS

Zilversmit, D. B.; Entenman, C.; Fishler, M. C.; Chaikoff, I. L.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/01/1943 EN
Relevância na Pesquisa
36.15%
1. A method for the determination of turnover time and turnover rate of plasma phospholipid is presented. 2. During the postabsorptive state 5.2 to 8.0 mg. of phospholipid phosphorus are turned over per hour in the plasma of dogs weighing 6–9 kilos. 3. The amount of phospholipid in an organ that is supplied by plasma phospholipid per hour is calculated.

TISSUE CULTURE STUDIES : III. THE RELATIONSHIP OF INCORPORATION OF RADIOACTIVE PHOSPHORUS IN NUCLEIC ACID TO THE GROWTH OF CELLS IN VITRO

Hull, Wayne; Kirk, Paul L.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/03/1950 EN
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46.52%
Growing cultures are shown to incorporate more radioactive phosphorus into ribo- and desoxyribonucleic acid than non-growing cultures. Strong indications are found that the incorporation of inorganic phosphorus into desoxyribonucleic acid parallels the mitotic coefficient and serves as a sensitive index of synthesis of new cells. There are indications that the phosphorus compounds from which the DNA molecule was synthesized were in equilibrium with the inorganic phosphorus of the medium. The effect of the implant upon growth of new cells and the assay of growth is discussed. Metabolic turnover was increased in adequate medium.

THE MORTALITY OF BACTERIOPHAGE CONTAINING ASSIMILATED RADIOACTIVE PHOSPHORUS

Hershey, A. D.; Kamen, M. D.; Kennedy, J. W.; Gest, H.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/01/1951 EN
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46.77%
The bacteriophage T4 containing assimilated radioactive phosphorus is inactivated at a rate proportional to the specific radioactivity of the constituent phosphorus. The beta radiation from the phosphorus makes a negligible contribution to this effect. The inactivation is therefore a direct consequence of the nuclear reaction, which kills the phage with an efficiency of about 1/12. Several phages related to T4 behave similarly. When radioactive phage is grown from a seed of non-radioactive phage, all of the phage progeny are subject to killing by radioactive decay. The phage is killed by beta radiation from P32 with an efficiency of about 1/100 per ionization within the particle volume. Bacteriophage T4 and its relatives contain about 500,000 atoms of phosphorus per infective particle. Virtually all this phosphorus is adsorbed to bacteria with the specificity characteristic of the infective particles, and none of it can be removed from the particles by the enzyme desoxyribonuclease. The phosphorus content per particle, together with the published data on analytical composition, indicates a particle diameter close to 110 mµ for the varieties of phage studied.

INACTIVATION OF BACTERIOPHAGES BY DECAY OF INCORPORATED RADIOACTIVE PHOSPHORUS

Stent, Gunther S.; Fuerst, Clarence R.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/03/1955 EN
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36.43%
The inactivation of the phages T1, T2, T3, T5, T7, and λ by decay of incorporated P32 has been studied. It was found that these phages fall into two classes of sensitivity to P32 decay: at the same specific activity of P32 in their deoxyribonucleic acid (DNA), T2 and T5 are inactivated three times as rapidly as T1, T3, T7, and λ. Since the strains of the first class were found to contain about three times as much total phosphorus per phage particle as those of the second) it appears that the fraction of all P32 disintegrations which are lethal is very nearly the same in all the strains. This fraction α depends on the temperature at which decay is allowed to proceed, being 0.05 at –196°C., 0.1 at +4°C., and 0.3 at 65°C. Decay of P32 taking place only after the penetration of the DNA of a radioactive phage particle into the interior of the bacterial cell can still prevent the reproduction of the parental phage, albeit inactivation now proceeds at a slightly reduced rate. T2 phages inactivated by decay of P32 can be cross-reactivated; i.e., donate some of their genetic characters to the progeny of a mixed infection with a non-radioactive phage. They do not, however, exhibit any multiplicity reactivation or photoreactivation. The fact that at low temperatures less than one-tenth of the P32 disintegrations are lethal to the phage particle and the dependence of the fraction of lethal disintegrations on temperature can be accounted for by the double stranded structure of the DNA macromolecule.

DECAY OF INCORPORATED RADIOACTIVE PHOSPHORUS DURING REPRODUCTION OF BACTERIOPHAGE T2

Stent, Gunther S.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/07/1955 EN
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36.43%
The multiplication of vegetative T2 bacteriophage in B/r bacteria has been followed by studying the lethal effects of decay of incorporated radiophosphorus P32 at various stages of the eclipse period. Experiment I. Non-radioactive B/r bacteria were infected with highly radioactive (i.e. P32-unstable) T2 and infection allowed to proceed at 37°C. for various numbers of minutes before freezing the infected cells and storing them in liquid nitrogen. The longer development had been allowed to proceed at 37°C. before freezing, the slower the inactivation of the frozen infective centers by P32 decay. Samples which were frozen after incubation for 9 minutes were completely stable. Experiment II. Radioactive B/r bacteria in radioactive growth medium were infected with non-radioactive (i.e. stable) T2 and incubated for various lengths of time before being frozen and stored in liquid nitrogen, like those of Experiment I. In this case, the infective centers were stable to P32 decay as long as they were frozen before the end of the eclipse period. The T2 progeny phages issuing from the infected bacteria were P32-unstable. Experiment III. Radioactive B/r bacteria in radioactive medium were infected with radioactive (i.e. P32-unstable) T2 and otherwise incubated and frozen like those of the first two experiments. In this case...

INACTIVATION OF BACTERIA BY DECAY OF INCORPORATED RADIOACTIVE PHOSPHORUS

Fuerst, Clarence R.; Stent, Gunther S.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/09/1956 EN
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36.49%
Cultures of Escherichia coli will not grow in media containing very high specific activities of radiophosphorus P32, the inhibition of growth being due to the decay of assimilated P32 atoms. Experiments with a differentially labeled thymineless strain of E. coli show that the P32 disintegrations which occur in the bacterial deoxyribonucleic acid, i.e. in the nucleus, are mainly responsible for the inactivation of the cell. The kinetics with which radioactive bacterial populations are inactivated indicate that the function of several nuclei per bacterial cell must be eliminated by P32 decay before the ability to generate a colony is lost. The efficiency with which each P32 disintegration inactivates the nucleus in which it has occurred is calculated to be 0.02 (at –196°), i.e., similar in magnitude to the killing efficiency of P32 decay in bacteriophages. P32 decay and thymine starvation cooperate in bringing about the death of individuals of the thymineless strain, from which observation it is inferred that "thymineless death" is likewise a nuclear inactivation. The descendants of a non-radioactive bacterial culture grown for several generations in the presence of P32 and the descendants of a radioactive culture grown in the absence of P32 are inactivated by P32 decay in a manner which indicates that the phosphorus atoms of bacterial nuclei are dispersed among the progeny nuclei in their line of descendance.

Radioactive Phosphorylation of Alcohols to Monitor Biocatalytic Diels-Alder Reactions

Nierth, Alexander; Jäschke, Andres
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 22/06/2011 EN
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36.25%
Nature has efficiently adopted phosphorylation for numerous biological key processes, spanning from cell signaling to energy storage and transmission. For the bioorganic chemist the number of possible ways to attach a single phosphate for radioactive labeling is surprisingly small. Here we describe a very simple and fast one-pot synthesis to phosphorylate an alcohol with phosphoric acid using trichloroacetonitrile as activating agent. Using this procedure, we efficiently attached the radioactive phosphorus isotope 32P to an anthracene diene, which is a substrate for the Diels-Alderase ribozyme—an RNA sequence that catalyzes the eponymous reaction. We used the 32P-substrate for the measurement of RNA-catalyzed reaction kinetics of several dye-labeled ribozyme variants for which precise optical activity determination (UV/vis, fluorescence) failed due to interference of the attached dyes. The reaction kinetics were analyzed by thin-layer chromatographic separation of the 32P-labeled reaction components and densitometric analysis of the substrate and product radioactivities, thereby allowing iterative optimization of the dye positions for future single-molecule studies. The phosphorylation strategy with trichloroacetonitrile may be applicable for labeling numerous other compounds that contain alcoholic hydroxyl groups.

Hydrocolloid-Stabilized Magnetite for Efficient Removal of Radioactive Phosphates

Vellora Thekkae Padil, Vinod; Rouha, Michael; Černík, Miroslav
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
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Liquid radioactive waste is a common by-product when using radioactive isotopes in research and medicine. Efficient remediation of such liquid waste is crucial for increasing safety during the necessary storage of the material. Herein, we present a novel Gum Karaya stabilized magnetite for the efficient removal of radioactive phosphorus 32P from liquid radioactive waste. This environmentally friendly material is well suited to be used as a nanohydrogel for the removal of liquid waste, which can then be stored in a smaller space and without the risk of the spills inherent to the initial liquid material. The maximum adsorption capacity of the GK/M in this study was found to be 15.68 GBq/g. We present a thorough morphological characterization of the synthesised GK/M, as well as a discussion of the possible phosphorus adsorption mechanisms.

Phosphorus efficiencies and responses of barley (Hordeum vulgare L.) to arbuscular mycorrhizal fungi grown in highly calcareous soil

Zhu, Y.; Smith, F.; Smith, S.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2003 EN
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36.24%
Two experiments were carried out to investigate phosphorus efficiencies and mycorrhizal responsiveness in an improved cultivar (Clipper) and a landrace (Sahara) of barley (Hordeum vulgare L.). In experiment 1, two pot sizes were used to evaluate the effect of soil volume on P uptake and mycorrhizal responsiveness. In experiment 2, a compartmented ("cross-pot") system was used to monitor (32)P delivery by external hyphae of arbuscular mycorrhizal fungi (AMF) to the host plant. Results showed that, irrespective of growth conditions, Sahara had much larger root biomass than Clipper and consequently substantially more P was allocated to roots in Sahara than in Clipper. Specific root length in Clipper was much longer than in Sahara. Increase in soil volume enhanced percentage root length colonised by AMF, plant growth and P uptake, and Sahara was more sensitive to changes in soil volume than Clipper. Pot size (soil volume) used to assess responsiveness to AMF by different plant species or genotypes with different root/shoot ratios might be a confounding factor. Clipper was more responsive to AMF than Sahara in terms of tissue P concentrations, which is partly related to their differences in root/shoot ratios. However, increases in SPU [specific P uptake...

Etude à l'aide du phosphore radioactif (P32) de la vitesse de passage d'un aliment liquide dans les diverses parties de l'intestin de l'abeille; Study on the transit speed of a liquid food in the various parts of honeybee gut with radioactive phosphorus (P32)

Zhdanov, S. V.; Dolotovskaya, U.A.; Kozyrev, E.M.
Fonte: INRA - Instituto Nacional de Investigação Agronômica da França Publicador: INRA - Instituto Nacional de Investigação Agronômica da França
Tipo: Journal Article-postprint
FR
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46.33%

Absorção e translocação de fósforo em dois cultivares de mamoneira (Ricinus communis L.), 'Campinas' e 'Guarani', com uso de 32p; Absorption and translocation of phosphorus labelled with 32p in Ricinus communis cvs. Campinas and Guarani

Nakagawa, Julio; Neptune, André Martin Louis; Muraoka, Takashi
Fonte: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz Publicador: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 01/01/1982 POR
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Com o objetivo de estudar a absorção e translocação do fósforo na cultura da mamoneira, instalou-se um ensaio em vasos com os cultivares 'Campinas' e 'Guarani' e empregou-se o fósforo radioativo (32p) como traçador. Os quatro tratamentos constaram da aplicação ao solo de 65 ppm de P contendo 32p, quando as plantas apresentavam seis, nove, doze e quatorze folhas, respectivamente e cortadas com nove, doze e quatorze folhas e as do quarto tratamento após 21 días da aplicação do fertilizante marcado. Através dos dados obtidos, pode-se concluir que, neste solo com baixo teor de fósforo, a aplicação deste elemento, na época da emissão de ínflorescências primárias, não influi no desenvolvimento das inflorescências, uma vez que se formam as expensas de fósforo previamente acumulado no pecíolo e no limbo, e que para lá se desloca a fim de participar do metabolismo de formação e desenvolvimento. Em outros termos, o fósforo, quando aplicado tardiamente, não incrementará a produção dos cachos primários e, consequentemente, não pode esperar que o potencial máximo do cultivar seja atingido, pois os cachos primários representam, no mínimo, 30% da produção total da mamoneira.; A pot experiment was carried out with treatments consisting of applications of solution of 65 ppm phosphorus labelled with 32p...

Efficiency of phosphorus (32P) uptake and use by eucalyptus seedlings and rice; Eficiência de absorção e utilização de fósforo (32P) por mudas de eucalipto e arroz

Luca, Edgar Fernando de; Boaretto, Antonio Enedi; Muraoka, Takashi; Chitolina, José Carlos
Fonte: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz Publicador: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; Formato: application/pdf
Publicado em 01/09/2002 POR
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36.39%
The knowledge on different plant abilities to take up soil phosphorus and its use for growth can be important to improve markedly the efficiency of phosphorus fertilization. Having this in mind, an experiment was carried out under greenhouse conditions to test the hypothesis that eucalyptus seedlings are more efficient than rice in absorbing phosphorus from low solubility sources applied to a Quartzamment soil, testing different efficiency concepts. The phosphorus sources Ca(H2(32)PO4).H 2O, CaH32PO4.2H2O and Ca3(32PO4)2 , synthesised in laboratory and identified by X-ray difratometry and thermal differential analyses, were used as radioactive tracers. It was concluded that rice is more efficient in absorbing phosphorus from these low solubility sources, while eucalyptus presents a higher coefficient of biologic P utilisation. The "difference" method (conventional) that in based on P recovery by plants, underestimated the absorption of this nutrient for both species in relation to the isotopic method.; O conhecimento das habilidades das plantas em absorver o fósforo do solo e utilizá-lo no seu crescimento é uma via que pode ser importante para melhorar sensivelmente a eficiência da adubação fosfatada. Conduziu-se um experimento em casa-de-vegetação com objetivo de testar a hipótese de que o eucalipto é mais eficiente do que o arroz em absorver o fósforo de fontes poucos solúveis aplicadas a um Neossolo Quartzarênico...