312 research outputs found
The fraction of Bose-Einstein condensed triplons in TlCuCl3 from magnetization M(T,H)-data
In this study we calculate the fraction of condensed magnetic quasiparticles
of TlCuCl3 from magnetization M(T,H)-data. It is independent of the direction
of the magnetic field and slightly decreases with increasing magnetic field.Comment: 8 pages, 10 figure
Experimental tests for macroscopic phase coherence in magnetic-quasiparticle condensates of insulating spin systems
For most kinds of already known Bose-Einstein condensates experimental
evidence for the existence of a macroscopic coherent quantum state has been
provided, e.g., from the observation of interference phenomena, the formation
vortices, the detection of Josephson effects, or even by the manifestation of
superfluid behaviour. However, none of these hallmarks for a true, macroscopic
phase-coherent state has ever been reported for any insulating spin system in a
solid in which magnetic bosonic quasiparticles are thought to condense close to
a quantum critical point. We describe an attempt to detect superfluid behaviour
in TlCuCl3, and discuss in more detail a proposal for an experiment in which
the a.c. Josephson effect can be probed by using a device composed of two
weakly coupled magnetic insulators with different critical fields. We conclude
that the detection of the a.c. Josephson effect is feasible for a proper choice
of compounds with realistic material parameters.Comment: 6 pages, 2 figure
Selection of Candidates for Lung Transplantation: The First Italian Consensus Statement
Lung transplantation is a well-established treatment for selected patients with advanced chronic respiratory insufficiency. Recognizing those patients with end-stage lung disease who might benefit from lung transplantation is a crucial task. Considering the presence of inadequate evidence-based practice, international and national scientific societies provided consensus opinions regarding the appropriate timing of listing. The Study Group for Thoracic Organs Transplantation (branch of the Italian Society for Organs Transplantation) promoted and realized a Delphi conference among the Italian lung transplantation centers to provide guidance to clinical practice based on international recommendations. The experts from the nine Italian centers completed two rounds of standardized questionnaires (answer rate, 100%): 42 statements received a consensus >= 80%. The selected statements presented in this article are intended to assist Italian clinicians in selecting patients for lung transplantation
The effects of disorder in dimerized quantum magnets in mean field approximations
We study theoretically the effects of disorder on Bose-Einstein condensates
(BEC) of bosonic triplon quasiparticles in doped dimerized quantum magnets. The
condensation occurs in a strong enough magnetic field Hc, where the
concentration of bosons in the random potential is sufficient to form the
condensate. The effect of doping is partly modeled by delta - correlated
disorder potential, which (i) leads to the uniform renormalization of the
system parameters and (ii) produces disorder in the system with renormalized
parameters. These approaches can explain qualitatively the available
magnetization data in the Tl_(1-x)K_(x)CuCl_3 compound taken as an example. In
addition to the magnetization, we found that the speed of the Bogoliubov mode
has a peak as a function of doping parameter, x. No evidence of the pure Bose
glass phase has been obtained in the BEC regime.Comment: Includes 19 pages, 5 figure
Sialadenoma papilliferum of the bronchus: a rare tumour of salivary gland origin
Sialadenoma papilliferum is a benign salivary tumour which rarely occurs in the bronchial tree. Up to now, only four cases of pulmonary papillary sialadenoma have been reported in the literature.We discuss the case of a male patient with an accidental finding of a middle lobe nodule. The patient underwent a minimally invasive anatomical resection of the lobe to remove the lesion; the postoperative course was regular, and he was healthy at the last follow-up
Twenty years experience in oncologic surgery for primary cardiac tumors
Introduction. Primary cardiac tumors are uncommon in cardiac surgery. To investigate the clinical presentation, surgical results and long-term follow-up we retrospectively analyzed our experience in the treatment of primary cardiac tumors.
Patients and methods. Ninety-one patients with primary cardiac tumors underwent surgery in our department in the last 20 years. Fifthy-one patients were female, the mean age was 62,2 years. Sixty-three had myxomas, 22 had papillary fibroelastoma, 4 had malignant neoformations and 2 had other benign tumors.
Results. All myxomas, fibroelastomas and angiomyolipoma were radically removed. Only a palliative treatment was possible in malignant disease. In-hospital mortality was 1.2%. The mean follow-up time was 78.5 months. Three patients had recurrence of myxoma, all patients with malignant disease dead during the follow-up.
Discussion. Primary benign cardiac tumors can be treated with low morbidity and mortality. The follow-up demonstrates that radical surgery is curative in case of benign tumors. The prognosis of malignant tumors is still poor. Palliative procedures have small impact on survival in these patients
Validated Prognostic Scores to Predict Outcomes in ECLS-Bridged Patients to Lung Transplantation
Selection of patients who may benefit from extracorporeal life support (ECLS) as a bridge to lung transplant (LTx) is crucial. The aim was to assess if validated prognostic scores could help in selecting patients who may benefit from ECLS-bridging predicting their outcomes. Clinical data of patients successfully ECLS-bridged to LTx from 2009 to 2021 were collected from two European centers. For each patient, we calculated Sequential Organ Failure Assessment (SOFA), Simplified Acute Physiology Score III (SAPS III), Acute Physiology and Chronic Health Evaluation II (APACHE II), before placing ECLS support, and then correlated with outcome. Median values of SOFA, SAPS III, and APACHE II were 5 (IQR 3-9), 57 (IQR 47.5-65), and 21 (IQR 15-26). In-hospital, 30 and 90 days mortality were 21%, 14%, and 22%. SOFA, SAPS III, and APACHE II were analyzed as predictors of in-hospital, 30 and 90 days mortality (SOFA C-Index: 0.67, 0.78, 0.72; SAPS III C-index: 0.48, 0.45, 0.51; APACHE II C-Index: 0.49, 0.45, 0.52). For SOFA, the score with the best performance, a value ≥9 was identified to be the optimal cut-off for the prediction of the outcomes of interest. SOFA may be considered an adequate predictor in these patients, helping clinical decision-making. More specific and simplified scores for this population are necessary
The surplus transplant lung allocation system in italy: An evaluation of the allocation process via stochastic modeling
Responsabilidad social universitaria en Maracaibo, Venezuela
This article aims to analyze university social responsibility in Maracaibo, Venezuela. The work is based on the postulates of Rodriguez (2010), De la Cuesta (2011) and the Ministry of Education in Spain (2011), among others. It is a descriptive, field study. The population consisted of authorities from five universities, one (1) public and four (4) private, located in Maracaibo, who were accessed through a questionnaire composed of thirty-two (32) closed items. The instrument was validated by experts in the university management field. To determine the questionnaire’s reliability, the test-retest method was applied, obtaining a 0.94 coefficient. To analyze data, the arithmetic mean or average was used. Results indicate that the universities under study exhibit a social responsibility model with an instrumental, entrepreneurial tendency, where knowledge is seen as the main asset available for society’s use. However, a greater integration of these higher education institutions with their stakeholders is required.
El presente artículo tiene como objetivo analizar la responsabilidad social universitaria en Maracaibo, Venezuela. El trabajo se sustenta en los postulados de Rodríguez (2010), De la Cuesta (2011), el Ministerio de Educación de España (2011), entre otros. El estudio fue descriptivo, de campo. La población estuvo conformada por autoridades de cinco (5) universidades, una (1) pública y cuatro (4) privadas ubicadas en Maracaibo, a las cuales se accedió mediante un cuestionario compuesto por treinta y dos (32) ítems cerrados. El instrumento fue validado por expertos en el ámbito de la gerencia universitaria. Para determinar la confiabilidad del cuestionario se aplicó el método test-retest, obteniéndose un coeficiente de 0,94. Para analizar los datos se utilizó el promedio aritmético o media. Los resultados indican que las universidades estudiadas exhiben un modelo de responsabilidad social de tendencia empresarial instrumental, donde el conocimiento se perfila como el principal activo disponible para su uso por la sociedad, pero se requiere una mayor integración de las instituciones de educación superior con sus stakeholders.
 
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