170 research outputs found
Rain: Relaxations in the sky
We demonstrate how, from the point of view of energy flow through an open
system, rain is analogous to many other relaxational processes in Nature such
as earthquakes. By identifying rain events as the basic entities of the
phenomenon, we show that the number density of rain events per year is
inversely proportional to the released water column raised to the power 1.4.
This is the rain-equivalent of the Gutenberg-Richter law for earthquakes. The
event durations and the waiting times between events are also characterised by
scaling regions, where no typical time scale exists. The Hurst exponent of the
rain intensity signal . It is valid in the temporal range from
minutes up to the full duration of the signal of half a year. All of our
findings are consistent with the concept of self-organised criticality, which
refers to the tendency of slowly driven non-equilibrium systems towards a state
of scale free behaviour.Comment: 9 pages, 8 figures, submitted to PR
Short pulse generation in solid state lasers by a novel passive technique
Includes bibliographical references (page 216).A novel passive Q-switching technique based on self-focusing is studied theoretically and experimentally. In this paper we present results obtained with a simple aberrationless gaussian model that describes the short pulse generation dynamics for different cavity configurations and different nonlinear characteristics of the focusing medium. Experimental results are also presented that are in good agreement with the predictions of the theoretical model. Preliminary results in ultrashort pulse generation are also presented
Competencias adquiridas y aplicadas por pasantes del Instituto de FisiopatologÃa Cardiovascular
En Argentina, los alumnos universitarios participan poco en investigación. El Instituto de FisiopatologÃa Cardiovascular (INFICA), Facultad de Medicina, Universidad de Buenos Aires, los incluyó en tareas investigativas desde 1992. El objetivo del trabajo es analizar qué competencias adquirieron quienes fueron o son pasantes del INFICA y en qué aspectos de su vida académica y profesional las aplican. Se administró una encuesta estructurada, voluntaria y anónima, con datos personales y académicos, conocimientos y habilidades adquiridas y utilidad de los mismos. La tasa de respuesta fue: 66%; 71% fueron mujeres; edad promedio 28,7 años (DE= 7,37). El 88% tiene como carrera medicina, siendo el 52%, graduado. Los alumnos aprendieron recopilación (86,6%) y análisis (80%) de datos. El 80% lo utiliza para comprender temas en clases y el 60% para elaborar trabajos escritos. El 94% de los graduados realizó formación de postgrado, aplicando las siguientes competencias: análisis (93,3%) y recopilación (80%) de datos y elaboración y exposición de trabajos cientÃficos (80%). Las utilizan en la participación (93,3%) y comprensión (73.3%) de temas en actividades académicas. El 66% de los graduados tiene actividad profesional, aplicando las competencias en exposición (100%) y elaboración (90,9%) de trabajos cientÃficos. En consecuencia, los pasantes adquieren competencias relacionadas con recopilar, analizar datos y elaborar y exponer trabajos cientÃficos, siendo aplicables en varios aspectos de su formación y profesión. En definitiva, la pasantÃa les ha brindado las bases a los futuros profesionales acerca de la metodologÃa de la investigación e incentivado la producción cientÃfica.Fil: Rancich, Ana MarÃa. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de BioquÃmica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de BioquÃmica y Medicina Molecular; ArgentinaFil: Méndez Diodati, Nahuel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de BioquÃmica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de BioquÃmica y Medicina Molecular; ArgentinaFil: Merino, Sabrina F.. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de BioquÃmica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de BioquÃmica y Medicina Molecular; ArgentinaFil: Donato, Pablo MartÃn. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de BioquÃmica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de BioquÃmica y Medicina Molecular; ArgentinaFil: Gelpi, Ricardo Jorge. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de BioquÃmica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de BioquÃmica y Medicina Molecular; Argentin
Drug-drug interactions between palbociclib and proton pump inhibitors may significantly affect clinical outcome of metastatic breast cancer patients
BACKGROUND: Proton-pump-inhibitors (PPIs) are frequently prescribed for the management of anticancer drug-related gastrointestinal symptoms. Palbociclib is a weak base with pH-dependent solubility and potential drug-drug interaction at the absorption level may affect clinical pharmacokinetics. The current study was aimed at investigating the effect of co-administration of PPIs and palbociclib on progression-free survival (PFS) in metastatic breast cancer (mBC) patients. PATIENTS AND METHODS: Patients affected by estrogen receptor-positive, human epidermal growth factor receptor 2-negative mBC, who were candidates for first-line treatment with palbociclib, were enrolled in this retrospective observational study. Patients were defined as ‘no concomitant PPIs’ if no PPIs were administered during palbociclib treatment, and as ‘concomitant PPIs’ if the administration of PPIs covered the entire or not less than two-thirds of treatment with palbociclib. All clinical interventions were made according to clinical practice. RESULTS: A total of 112 patients were enrolled in the study; 56 belonged to the ‘no concomitant PPIs’ group and 56 to the ‘concomitant PPIs’ group. Seventy-one patients were endocrine-sensitive and received palbociclib and letrozole, and 43 were endocrine-resistant and were treated with palbociclib and fulvestrant. The most prescribed PPI was lansoprazole. Patients taking PPIs had a shorter PFS than those taking palbociclib and endocrine therapy alone (14.0 versus 37.9 months, P 2 hematological toxicities [Common Terminology Criteria for Adverse Events (CTCAE) scale]. CONCLUSIONS: The present study demonstrates that concomitant use of PPIs in mBC patients treated with palbociclib has a detrimental effect on PFS. Therefore, it is recommended to prescribe PPIs with caution in these patients, strictly adhering to the indications in the summary of product characteristics (RCP)
Psychosocial care for adult cancer patients: guidelines of the Italian Medical Oncology Association
SIMPLE SUMMARY: People with cancer often experience psychological and social needs, related to their disease and treatments, that can negatively impact quality of life. Various social interventions can be helpful but are not always offered to patients who would benefit from them. This guideline aims to help oncology professionals address the psychosocial aspects of their adult patients and of those who care for them. It was compiled by a multidisciplinary panel, including patients, using rigorous methodology. Topics include patient information and communication, screening and management of psychosocial needs, and caregiver support. In particular, evidence emphasizes that nurses play a central role in providing psychosocial care and information for cancer patients, and that Physician communication skills must be improved with specific evidence-based training. In addition, psychosocial needs must be promptly detected and managed, especially with appropriate non-pharmacological interventions. ABSTRACT: Psychosocial morbidity can have negative consequences for cancer patients, including maladaptive coping, poor treatment adherence, and lower quality of life. Evidence shows that psychosocial interventions can positively impact quality of life, as well as symptoms and side effects; however, they are not always offered to patients who might benefit from them. These guidelines were produced by a multidisciplinary panel of 16 experts, including patients, following GRADE methodology. The panel framed clinical questions and voted on outcomes to investigate. Studies identified by rigorous search strategies were assessed to rate certainty of evidence, and recommendations were formulated by the panel. Although the quality of the evidence found was generally moderate, interventions could be recommended aimed at improving patient information, communication with healthcare professionals and involvement in decision-making; detecting and managing patient psychosocial needs, particularly with non-pharmacological therapy; and supporting families of patients with advanced cancer. The role of nurses as providers of information and psychosocial care is stressed. Most recommended interventions do not appear to necessitate new services or infrastructures, and therefore do not require allocation of additional resources, but predominantly involve changes in clinical staff behavior and/or ward organization. Patients should be made aware of psychosocial care standards so that they can expect to receive them
Tri-critical behavior in rupture induced by disorder
We discover a qualitatively new behavior for systems where the load transfer
has limiting stress amplification as in real fiber composites. We find that the
disorder is a relevant field leading to tri--criticality, separating a
first-order regime where rupture occurs without significant precursors from a
second-order regime where the macroscopic elastic coefficient exhibit power law
behavior. Our results are based on analytical analysis of fiber bundle models
and numerical simulations of a two-dimensional tensorial spring-block system in
which stick-slip motion and fracture compete.Comment: Revtex, 10 pages, 4 figures available upon reques
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