113 research outputs found

    Induced pseudoscalar coupling of the proton weak interaction

    Full text link
    The induced pseudoscalar coupling gpg_p is the least well known of the weak coupling constants of the proton's charged--current interaction. Its size is dictated by chiral symmetry arguments, and its measurement represents an important test of quantum chromodynamics at low energies. During the past decade a large body of new data relevant to the coupling gpg_p has been accumulated. This data includes measurements of radiative and non radiative muon capture on targets ranging from hydrogen and few--nucleon systems to complex nuclei. Herein the authors review the theoretical underpinnings of gpg_p, the experimental studies of gpg_p, and the procedures and uncertainties in extracting the coupling from data. Current puzzles are highlighted and future opportunities are discussed.Comment: 58 pages, Latex, Revtex4, prepared for Reviews of Modern Physic

    Мониторинг редокс-потенциала плазмы крови в процессе ее карантинизации (предварительное сообщение)

    Get PDF
    The purpose of the study: to identify significant changes in the electrochemical properties of quarantine-stored blood plasma and of donor blood plasma during its in vitro mixing with quarantined plasma in order to assess the effect of transfusion of quarantine-stored plasma on recipient plasma in a model experiment. Materials and methods. Blood plasma of 20 clinically healthy volunteer donors was quarantined for 6 months at -40°C. Monitoring of the redox potential (RP) of the quarantined plasma was carried out directly on the day of sampling without freezing the sample, and then on days 1, 3, 7 and 14, as well as after 1, 1.5, 2, 3, 4, 5 and 6 months of storage of frozen samples. Each of 15 blood plasma samples donated by clinically healthy volunteers was mixed in vitro with blood plasma quarantined for 6 months at a ratio 1:1, and the RP of the mixture was measured by a platinum microelectrode technique. Results. It was found that during the storage of quarantined samples at a temperature of -40°C, the blood RP shifted to more positive values in 70% of cases. Addition of the quarantined plasma to the plasma of practically healthy volunteer donors also led to a shift in the final mixture RP to positive values in 13 of 15 cases (87%). Conclusion. Significant changes in RP values have been found when measuring the RP of the quarantined blood plasma, demonstrating predominantly oxidative processes in the plasma. Since significant shift of RP in blood plasma to the positive values has been associated with the deterioration of the patient's state, we concluded that further clinical studies on the use of quarantined plasma with high positive RP values are warranted.Цель исследования: выявление значимых изменений электрохимических свойств плазмы крови в процессе карантинизации и плазмы крови доноров при взаимодействии с карантинизованной плазмой in vitro для оценки влияния трансфузии в модельном эксперименте. Материалы и методы. Плазму крови 20-и практически здоровых доноров-добровольцев карантинизировали в течение 6-и месяцев при -40°С. Мониторинг редокс-потенциала (РП) карантинизованной плазмы осуществляли непосредственно в день забора без замораживания образца, на 1, 3, 7, 14 -е сутки, а затем по достижении 1, 1,5, 2, 3, 4, 5, 6-и месяцев хранения. Плазму крови 15-и практически здоровых доноров-добровольцев смешивании в соотношении 1:1 с плазмой крови, карантинизованной в течение 6 месяцев in vitro и измеряли РП смеси. Измерения РП проводили на платиновом микроэлектроде. Результаты. Обнаружили, что в процессе карантинизации при температуре -40°С РП плазмы крови в 70% случаев смещается в область более положительных значений. Доказали in vitro, что добавление к плазме практически здоровых доноров-добровольцев карантинизованной плазмы в 13 из 15 случаев (87%) также приводило к смещению величины РП конечной смеси в область положительных значений. Заключение. С помощью измерения РП карантинизованной плазмы крови обнаружили значимые изменения, которые свидетельствуют о протекании в плазме преимущественно окислительных процессов. Учитывая данные о том, что значимое смещение РП в плазме крови в область положительных значений ассоциировано с ухудшением состояния пациента, сделали вывод о необходимости проведения дополнительных клинических исследований по применению карантинизованной плазмы с высокими положительными величинами РП.

    The PHENIX Experiment at RHIC

    Full text link
    The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

    ALK-positive histiocytosis: a new clinicopathologic spectrum highlighting neurologic involvement and responses to ALK inhibition

    Get PDF
    ALK-positive histiocytosis is a rare subtype of histiocytic neoplasm first described in 2008 in three infants with multisystemic disease involving the liver and hematopoietic system. This entity has subsequently been documented in case reports and series to occupy a wider clinicopathologic spectrum with recurrent KIF5B-ALK fusions. The full clinicopathologic and molecular spectra of ALK-positive histiocytosis remain, however, poorly characterized. Here, we describe the largest study of ALK-positive histiocytosis to date, with detailed clinicopathologic data of 39 cases, including 37 cases with confirmed ALKrearrangements. The clinical spectrum comprised distinct clinical phenotypic groups: infants with multisystemic disease with liver and hematopoietic involvement, as originally described (Group 1A: 6/39), other patients with multisystemic disease (Group 1B: 10/39), and patients with single-system disease (Group 2: 23/39). Nineteen patients of the entire cohort (49%) had neurologic involvement (seven and twelve from Groups 1B and 2, respectively). Histology included classic xanthogranuloma features in almost one third of cases, whereas the majority displayed a more densely cellular, monomorphic appearance without lipidized histiocytes but sometimes more spindled or epithelioid morphology. Neoplastic histiocytes were positive for macrophage markers and often conferred strong expression of phosphorylated-ERK, confirming MAPK pathway activation. KIF5B-ALK fusions were detected in 27 patients, while CLTC-ALK, TPM3-ALK, TFG-ALK, EML4-ALK and DCTN1-ALK fusions were identified in single cases. Robust and durable responses were observed in 11/11 patients treated with ALK inhibition, ten with neurologic involvement. This study presents the existing clinicopathologic and molecular landscape of ALK-positive histiocytosis, and provides guidance for the clinical management of this emerging histiocytic entity.Molecular tumour pathology - and tumour genetic

    Research and Science Today No. 2(4)/2012

    Full text link

    Thin-Film layers with Interfaces that reduce RF Losses on High-Resistivity Silicon Substrates

    Get PDF
    Radio-Frequency (RF) losses on High-Resistivity Silicon (HRS) substrates were studied for several different surface passivation layers comprising thin-films of SiC, SiN and SiO2 In many combinations, losses from conductive surface channels were reduced and increasing the number of interfaces between thin-films was found to be beneficial. In some cases the surface losses were completely eliminated. For example, with plasma-enhanced chemical-vapor deposition (PECVD) α-SiC layers up to a few tens of nm thick and exposed to nitridation or SiN growth at 850°C to form a SiC:N interface layer, values for the total losses of 1.6 dB/cm were achieved. Analysis of these layers was performed by using temperature dependent measurements of the RF losses on Coplanar Waveguides (CPWs), the capacitance-voltage characteristics and the sheet resistance along the Si surface. The overall results can be explained by assuming that the thin-films are so defected that they allow vertical current paths to highly-resistive interface layers where both fixed and mobile charge can be stored

    Monitoring of the Blood Plasma Redox Potential During Plasma Quarantining (Preliminary Report)

    Get PDF
    The purpose of the study: to identify significant changes in the electrochemical properties of quarantine-stored blood plasma and of donor blood plasma during its in vitro mixing with quarantined plasma in order to assess the effect of transfusion of quarantine-stored plasma on recipient plasma in a model experiment. Materials and methods. Blood plasma of 20 clinically healthy volunteer donors was quarantined for 6 months at -40°C. Monitoring of the redox potential (RP) of the quarantined plasma was carried out directly on the day of sampling without freezing the sample, and then on days 1, 3, 7 and 14, as well as after 1, 1.5, 2, 3, 4, 5 and 6 months of storage of frozen samples. Each of 15 blood plasma samples donated by clinically healthy volunteers was mixed in vitro with blood plasma quarantined for 6 months at a ratio 1:1, and the RP of the mixture was measured by a platinum microelectrode technique. Results. It was found that during the storage of quarantined samples at a temperature of -40°C, the blood RP shifted to more positive values in 70% of cases. Addition of the quarantined plasma to the plasma of practically healthy volunteer donors also led to a shift in the final mixture RP to positive values in 13 of 15 cases (87%). Conclusion. Significant changes in RP values have been found when measuring the RP of the quarantined blood plasma, demonstrating predominantly oxidative processes in the plasma. Since significant shift of RP in blood plasma to the positive values has been associated with the deterioration of the patient's state, we concluded that further clinical studies on the use of quarantined plasma with high positive RP values are warranted
    corecore