773 research outputs found
Efecto de cuatro fechas de siembra sobre la incidencia de insectos fitófagos en frijol En la región de Texcoco, México
El cultivo de frijol en nuestro país tiene profundas raíces milenarias. Actualmente el papel de esta leguminosa sigue siendo fundamental porque representa una fuente importante de ocupación e ingreso para la economía campesina, así como una garantía de seguridad alimentaria, vía autoconsumo, mientras que en la dieta representa la principal y única fuente de proteínas para amplias capas de la población mexicana (Varela, 1995). En nuestro país ocupa el segundo lugar en superficie cultivada
Suscetibilidade e morbidade na infecção do camundongo domestico, por Angiostrongylus costâricensis.
The clinical translation of plastic scintillation dosimetry
Contemporary radiotherapy focuses on achieving the best patient outcomes by delivering highly targeted treatments that often include small fields and high dose gradients. Plastic scintillators outperform traditional dosimeters in these fields as they are close to water-equivalent. However, the translation of scintillation dosimeters into the clinic has been limited by three roadblocks. The generation of Cerenkov radiation in an optic fibre irradiated by megavoltage radiation contaminates the scintillation signal. Two Cerenkov removal methods (spectral discrimination and air core) were found to be accurate in accounting for Cerenkov radiation and their clinical robustness was improved. The light readout system is often the limiting factor for the accuracy of scintillators. PMTs outperform camera-based systems, though their implementation for array dosimetry is complex. A novel system with a multianode PMT was constructed and enabled multiple light signals from an array to be simultaneously measured. Arrays of scintillation dosimeters are difficult to create due to the complex arrangement of detectors and their optical pathways. Two innovative approaches (square waveguides and 3D printing) were used to build prototype scintillation dosimeter arrays. These arrays showed that scintillation dosimeters can measure dose distributions with high spatial and temporal resolution. Addressing these roadblocks has enabled the clinical translation of scintillation dosimeters. In small field dosimetry, an air core dosimeter was used as a reference to calculate and predict correction factors for existing dosimeters. For brachytherapy, an array of scintillators provided real-time dose measurements that improved the safety of the treatment. For rotational treatments, a cylindrical array was used to verify the dose delivered during simulated stereotactic treatments. Traditional dosimeters cannot be used in these applications and this demonstrates the potential of scintillation dosimetry
Evolution in swimming "science" research
Swimming seems to be one of the
sports more studied .
More than one decade ago, Clarys
(1996) made an content analysis of
the research about swimming. However,
in these last 13 years several
developments happened in the
aquatic activities
The importance of drug metabolites synthesis: the case-study of cardiotoxic anticancer drugs
Anticancer drugs are presently guarantying more survivors as a result of more powerful drugs or combinations of drugs used in therapy. Thus, it has become more crucial to study and overcome the side effects of these therapies. Cardiotoxicity is one of the most relevant side effects on the long-term cancer survivors, because of its high social and economic impact. Drug metabolism can result in active metabolites or toxic metabolites that can lead to important side effects. The metabolites of anticancer drugs are possible culprits of cardiotoxicity; however, the cardiotoxicity of many of the metabolites in several drug classes was not yet suitably studied so far. On the other hand, the use of prodrugs that are bioactivated through metabolism can be a good alternative to obtain more cardio safe drugs. In this review, the methods to obtain and study metabolites are summarized and their application to the study of a group of anticancer drugs with acknowledged cardiotoxicity is highlighted. In this group of drugs, doxorubicin (DOX, 1), mitoxantrone (MTX, 2), cyclophosphamide (CTX, 3) and 5-fluorouracil (5-FU, 4) are included, as well as the tyrosine kinase inhibitors, such as imatinib (5), sunitinib (6) and sorafenib (7). Only with the synthesis and purification of considerable amounts of the metabolites can reliable studies be performed, either in vitro or in vivo that allow accurate conclusions regarding the cardiotoxicity of anticancer drug metabolites and then pharmacological prevention or treatment of the cardiac side effects can be done. © 2017 Informa UK Limited, trading as Taylor & Francis Group.This work was supported by FEDER funds through the Operational Programme for Competitiveness Factors?COMPETE and by national funds by the Funda??o para a Ci?ncia e Tecnologia (FCT) FCT/MCTES?Foundation for Science and Technology from the Minister of Science, Technology and Higher Education (PIDDAC) and European Regional Development Fund (ERDF) through the COMPETE?Programa Operacional Factores de Competitividade (POFC) programme, within the projects ?PTDC/DTP-FTO/1489/2014?POCI-01-0145-FEDER-016537?, in the framework of the programme PT2020 and by the project INNOVMAR - Innovation and Sustainability in the Management and Exploitation of Marine Resources (reference NORTE-01-0145-FEDER-000035, within Research Line NOVELMAR), supported by North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). V.M.C. (SFRH/BPD/110001/2015) acknowledges ?Funda??o para a Ci?ncia e Tecnologia (FCT)? for her Post Doc grant
Evolution on Swimming Science Research: content analysis of the “Biomechanics and Medicine in Swimming” Proceedings Books from 1971 to 2006
Swimming seems to be one of the
sports more studied .
More than one decade ago, Clarys
(1996) made an content analysis of
the research about swimming. However,
in these last 13 years several
developments happened in the
aquatic activities
Avaliação das alterações hemodinâmicas e do sensório em pacientes submetidos à rinoplastia estética sob anestesia local
OBJECTIVE: To determine the extension of hemodynamic changes in patients submitted to rhinoplasty under local anesthesia.MATERIALS AND METHODS: One hundred consecutive patients were investigated. They were operated between September 1988 and February 1989 at Clinica Planas,Barcelona, Spain. The evaluation included continuous monitoring of patients’ heart rate, arterial pressure, oxygen saturation, cardiac rhythm, and consciousness level throughout the procedure.RESULTS: The curve of arterial pressure variation was in accordance with the adrenaline peak, when injected subcutaneously (slower). This underscores theimportance of waiting at least 20 minutes before starting the procedure, in order to have the best vasoconstrictive effect. Sinus tachycardia is the most remarkable rhythmalteration observed in this study. It is present in almost all patients at the adrenaline peak. Hemodynamic alterations, mainly arterial hypertension, must be carefully observed, especially on predisposed patients.CONCLUSION: When the patient receives adequate preoperative care and intraoperative monitoring, rhinoplasty under local anesthesia is a safe procedure.OBJETIVO: Determinar as alterações hemodinâmicas em pacientes submetidos à rinoplastia estética sob anestesia local.MÉTODO: Foram investigados 100 pacientes consecutivos submetidos à rinoplastia estética sob anestesia local e sedação, no período de setembro de 1988 a fevereiro de 1989, na Clínica Planas, Barcelona, Espanha. A avaliação foi feita pela monitorização da freqüência cardíaca, pressão arterial sistêmica, saturação do oxigênio, ritmo cardíaco e nível de consciência do paciente, continuamente, do início ao término da intervenção.RESULTADOS: A curva de variação da pressão arterial esteve de acordo com o pico de ação da adrenalina, quando injetada subcutaneamente (mais lento), demonstrando a importância de esperar ao redor de 20 minutos após a injeção local para a obtençãode um efeito vasoconstritor ótimo. A taquicardia sinusal é a alteração de ritmo mais marcante neste estudo, aparecendo no pico de ação da adrenalina em quase todos os pacientes. As alterações hemodinâmicas, notadamente a hipertensão arterial, devem merecer cuidados, principalmente em pacientes predispostos.CONCLUSÃO: Quando o paciente está adequadamente assistido e monitorizado, a rinoplastia sob anestesia local é um procedimento seguro
Zeta function method and repulsive Casimir forces for an unusual pair of plates at finite temperature
We apply the generalized zeta function method to compute the Casimir energy
and pressure between an unusual pair of parallel plates at finite temperature,
namely: a perfectly conducting plate and an infinitely permeable one. The high
and low temperature limits of these quantities are discussed; relationships
between high and low temperature limits are estabkished by means of a modified
version of the temperature inversion symmetry.Comment: latex file 9 pages, 3 figure
Некоторые особенности продольной проводимости монокристаллов Y₁₋zPrzBa₂Cu₃O₇₋δ с различным содержанием празеодима
Исследовано влияние допирования празеодимом на проводимость в базисной плоскости ВТСП-монокристаллов Y₁₋zPrzBa₂Cu₃O₇₋δ. Установлено, что по мере ростаконцентрации празеодима в интервале 0.0 ≤ z ≤ 0.5 происходит существенное смещение температурных участков, отвечающих переходу вида металл–диэлектрик и режиму реализации псевдощелевой аномалии. При этом участки кривых в окрестности перехода металл–диэлектрик хорошо описываются с помощью асимптотической зависимости, отвечающей реализации в системе квантового критического режима, – так называемого закона «1/3». Показано, что избыточная проводимость Δσ(Т) образцов с промежуточным содержанием празеодима в широком интервале температур Tf < Т < T* подчиняется экспоненциальной температурной зависимости Δσ ~ (1 – Т/Т*)exp(Δ*ab/T) и может быть интерпретирована в терминах теории кроссовера БКШ–БЭК, где Т* представлена как среднеполевая температура сверхпроводящего перехода.Досліджено вплив допіювання празеодимом на провідність в базисній площині ВТНП-монокристалів Y₁₋zPrzBa₂Cu₃O₇₋δ. Встановлено, що по мірі зростання концентрації празеодиму в інтервалі 0.0 ≤ z ≤ 0.5 відбувається істотне зміщення температурних ділянок, які відповідають переходу виду метал–діелектрик та режиму псевдощілинної аномалії. При цьому ділянки кривих поблизу переходу метал–діелектрик добре описуються за допомогою асимптотичної залежності, що відповідає реалізації в системі квантового критичного режиму, – так званого закону «1/3». Показано, що надлишкова провідність Δσ(Т) зразків з проміжним вмістом празеодиму в широкому інтервалі температур Tf < Т < T* підкоряється експоненціальній температурній залежності Δσ ~ (1 – Т/T*)exp(Δ*ab/T) і може бути інтерпретована в термінах теорії кросовера БКШ–БЕК, де T* представлена як середньопольова температура надпровідного переходу.Conductivity in the basal plane of Pr-doped Y₁₋zPrzBa₂Cu₃O₇₋δ single crystals has been investigated. It is shown that with the increasing of praseodymium concentration in an interval 0.05 ≤ z ≤ 0.5 there is substantial displacement of temperature areas which respond to the metal–dielectric transition and to the mode of the pseudogap anomaly. Thus, sections of the curves in the vicinity of metal–dielectric transition are well described by asymptotic dependence which answers realization in the system of the quantum critical mode – the so-called law «1/3». It is shown that the excess conductivity for the analyzed samples shows dependence Δσ ~ (1 – Т/T* )exp(Δ*ab/T) in a wide temperature range Tf < Т < T* , where T* is the mean field temperature of superconducting transition. The temperature dependence of the pseudogap can be satisfactorily described in terms of the BCS–BEC crossover theoretical model
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