103 research outputs found
oxidative stress in post acute ischemic stroke patients relevance of early intensive neurorehabilitation
Oxidative stress was investigated in 10 post-acute stroke patients (median age 76.40 ± 2.09 years) assigned to in-hospital neurorehabilitation within 7 days of onset of a first-ever ischemic stroke. Assessments were made before and after neurorehabilitation. Outcome measures were the National Institutes of Health Stroke Scale (NIHSS), the Barthel Index (BI), the Katz Index (KI), the modified Rankin Scale (mRS) and the modified PULSES profile. Differences between scores evaluated before and after neurorehabilitation were expressed as Δ scores. Oxidative stress was assessed by measuring plasma amount of total peroxides by-products, nitrite/nitrate metabolites (NOx), total plasma antioxidant capacity (TEAC), Cu/Zn Superoxide Dismutase (Cu/ZnSOD), and serum urate concentration. Ten healthy volunteers (median age 74.30 ± 3.03 years) were recruited as controls for comparison of oxidative markers. Neurorehabilitation was associated with an improvement (P<0.05) of all the outcome measures except the mRS score. ΔPULSES correlated negatively with ΔBI scores (r=-0.656; P=0.040). Higher plasma levels of total peroxidative by-products and NOx metabolites were found in stroke patients than in controls before neurorehabilitation (P<0.05). Their values decreased in stroke patients after neurorehabilitation and were higher than those measured in controls (P<0.05). TEAC, Cu/Zn SOD and serum urate levels were lower in stroke patients than in controls before neurorehabilitation (P<0.05). Their values increased after neurorehabilitation so that no differences were observed comparing these values with those found in controls. Changes observed before and after neurorehabilitation in plasma NOx amount (ΔNOx) correlated positively with ΔNIHSS scores (r=0.675; P=0.032) and negatively with ΔPULSES (r=- 0.845; P=0.002). Cu/ZnSOD changes found before and after neurorehabilitation (ΔCu/Zn SOD) and ΔKI correlated positively (r=0.713; P=0.021). Our results showed that intensive neurorehabilitation may modulate oxidative stress and suggest its effectiveness in redox-mediated plasticity processes involved in the recovery of stroke-induced neurological deficits
Equation of state and Rankine-Hugoniot shock relations for realistic dynamical processes in stellar atmospheres
The complexity of many of the processes that take place in the solar atmosphere and interior has led
to the development of large, often multidimensional, numerical models to understand in detail the underlying physics. The study of phenomena from jets, surges and spicules, all the way to coronal mass
ejections (CME´s) or solar flares, of structures such as coronal arcs or of processes such as convection
or wave propagation, requires combining aspects of hydrodynamics, electromagnetism, plasma physics
and radiative transport. The development of numerical codes allows to solve in detail the equations
of those fields together. One of the basic aspects of these numerical codes is the equation of state
(EOS) that they implement. The EOS can be very simple, or very complex, depending on the degree
of realism needed to obtain relevant results.
A code at the forefront of the study of dynamical processes in the solar atmosphere is the Bifrost code,
developed at the University of Oslo. The fundamental EOS implemented in Bifrost deals with an ideal
gas with ionization/recombination and molecular formation/dissociation processes; it is realistic and
complex, and contains detailed microphysics. In this Graduation Thesis, we study the Bifrost EOS
from a double perspective: on the one hand, we carry out a detailed characterization of the EOS,
covering a large variety of aspects of the thermodynamics of partially ionized gases; on the other
hand, we study the shock transitions, in particular the Hugoniot curves, allowed by the EOS. Concerning the first aspect, the motivation to carry out the characterization is that the Bifrost EOS is not
well documented in the literature, which may constitute a problem for users of the code. Concerning
the second, one cannot find publications that describe the general behavior of shocks calculated with
this EOS. Given the ionization/recombination and molecular formation/dissociation processes taking
place in the solar atmosphere and included in the EOS, this study can be important to understand
the properties of shocks in the numerical models.
In the first part, the characterization of the EOS is carried out by calculating thermodynamic quantities on the basis of the tables of temperature and pressure as a function of density and internal energy
obtained from the EOS. For all the numerical calculations throughout this work original Python programs have been developed independently of Bifrost’s own program suite. To begin with, quantities
that do not require advanced numerical methods, such as atomic mass per particle or specific heat at
constant volume, are determined. Next, we calculate more advanced quantities, such as the entropy
distribution, ionization or dissociation coefficients, the Chandrasekhar adiabatic coefficients, the adiabatic gradient, the specific heat ratio γ, and the speed of sound, most of which require high-order
integrations or interpolations in one or two dimensions. The results are compared to those obtained
for the equation of state for the simplest ideal gases, i.e., those with no changes in chemical composition, showing the importance of taking into account the ionization and molecular formation processes.
In the case of entropy, the integration methods used are discussed, and the results compared with
the adiabatic curves facilitated by Dr H Ludwig obtained in the context of the COBOLD code, thus
verifying the validity of our results. Additionally, a detailed analytical expression for the internal
energy of the gas is developed that includes all the ionization levels for Hydrogen and Helium and the
formation of H2 molecules. The obtained formula is tested by making calculations in regions where
the chemical composition does not vary, obtaining an excellent fit to the general curves obtained from
the Bifrost EOS table in those regions. In this way, we now have at our disposal detailed information
about the ionization or molecular formation processes for H and He that take place in the different
ranges of density and internal energy (or pressure and temperature) in the solar atmosphere.
In the second part of the work, the jumps of pressure, temperature and density across a shock, the
corresponding increase in entropy and the incoming Mach numbers allowed by the Bifrost EOS are
studied in detail. For this, the Rankine-Hugoniot jump relations are used and the corresponding
Hugoniot curves are obtained, comparing the results to the well known ones for simple ideal gases.
First, analytical expressions are derived for the jumps allowed when the component of the internal
energy associated with ionization and molecular dissociation processes is uniform in the local thermodynamical domains where the pre-shock and post-shock states are located. This leads to unexpected
results when that component has a different value before and after the shock transition. Also, an analytical expression for the derivative of post-shock pressure with respect to post-shock density along
the Hugoniot curve is calculated in the general case. Then, a program is created to calculate Hugoniot
and Mach number curves numerically for the general case. To illustrate the results, curves starting at
pre-schock states in five regions of interest are calculated. Those curves have entry states located in
regions of simple ideal gas, but are such that, along their path, cross bands of ionization or molecular
dissociation. The crossing gives rise to striking consequences: the density jump can become much
larger in those shocks than in the standard simple ideal gas ones; duplication in the admissible pressure and temperature jumps for a given density jump is also obtained. The temperature jump for
a given pressure jump is much reduced compared to the simplest ideal gas case when the postshock
state is in one of those bands, the reason being that the incoming energy in the shock may be used to
ionize (or cause molecular dissociation in) the gas to a larger extent than in increasing its temperature.
Summarizing, we have derived a large number of thermodynamical and shock-related properties of
the gas described by the EOS of use in the Bifrost code exclusively on the basis of the temperature
and pressure maps as functions of density and internal energy. The results illuminate the behavior
of the gas in various regimes of interest for the calculations in the upper solar interior, photosphere,
chromosphere, transition region and corona. Particularly interesting results are obtained concerning
the properties of shocks. We expect that the current results can be of use to the community using the
Bifrost code in future
Evidence-based careflow management systems: the case of post-stroke rehabilitation
AbstractThe activities of a care providers’ team need to be coordinated within a process properly designed on the basis of available best practice medical knowledge. It requires a rethinking of the management of care processes within health care organizations. The current workflow technology seems to offer the most convenient solution to build such cooperative systems. However, some of its present weaknesses still require an intense research effort to find solutions allowing its exploitation in real medical practice. This paper presents an approach to design and build evidence-based careflow management systems, which can be viewed as components of a knowledge management infrastructure each health care organization should be provided with to increase its performance in delivering high quality care by efficiently exploiting the available knowledge resources. The post-stroke rehabilitation process has been taken as a challenging care problem to assess our methodology for designing and developing careflow management systems. Then a system was co-developed with a team of rehabilitation professionals who will be committed to use it in their daily work. The system’s main goal is to deliver a full array of rehabilitation services provided by an interdisciplinary team. They are related to identify which patients are most likely to benefit from rehabilitation, manage a rehabilitation treatment plan, and monitor progress both during rehabilitation and after return to a community residence. A model of the rehabilitation process was derived from an international guideline and adapted to the local organization of work. It involves different organizational units, such as wards, rehabilitation units, clinical laboratories, and imaging services. Several organizational agents work within them and play one or more roles. Each role is defined by the goals’ set that she/he must fulfill. Special effort has been given to the design and development of a knowledge-based system for managing exceptions, which may occur in daily medical work as any deviation from the normal flow of activities. It allows either avoiding or recovering automatically from expected exceptions. When they are not expected, organizational agents, with enough power to do that, are allowed to modify the scheduled flow of activities for an individual patient under the only constraint of justifying their decision. After an intensive testing in a research laboratory, the system is now in the process of being transferred in a real working setting with the full support of its future users
Ensino de Química em Oficina Temática: “O que vai pelo ralo, rastros ambientais de produtos que consumimos”
O presente trabalho aborda o uso de oficinas temáticas como meio de divulgação científica e proposta metodológica no ensino de química, uma vez que promovem um ensino contextualizado com valorização do sujeito como ser ativo nos processos de ensino e aprendizagem. Além disso, discute a importância desse tipo de atividade no processo de formação de professores, tanto como participantes quanto organizadores. Para isso, é apresentada uma oficina temática fundamentada nos três momentos pedagógicos e nas relações entre Ciência, Tecnologia e Sociedade, com enfoque ambiental. A oficina proposta faz parte de um projeto de extensão que busca evidenciar como os conhecimentos químicos podem desempenhar um papel importante no dia-a-dia, na tomada de decisões e na cidadania. Como resultados, são apresentadas as avaliações dos participantes e a discussão sobre os limites e as possibilidades da oficina desenvolvida.
Computational rehabilitation of neglect:Using state-space models to understand the recovery mechanisms
Unilateral spatial neglect is a neuropsychological syndrome often observed in right hemisphere stroke patients. The symptoms differ from subject to subject. A few rehabilitation approaches, e.g. prism adaptation, have demonstrated some effect in reducing the symptoms, but the underlying mechanisms are still largely unclear. Recently, neural models have been proposed to qualitatively describe cortical lesions, the resulting neglect symptoms and the effects of treatment. However, these predictions are qualitative and cannot be used to compare different hypotheses or to interpret symptoms at individual subjects level. Here we propose a computational model of the trial-by-trial dynamics of training-induced recovery from neglect. Neglect is modelled in terms of an impaired internal representation of visual stimuli in the left hemispace. The model assumes that recovery is driven by the mismatch between defective representations of visual stimuli and the corresponding hand positions. The model reproduces the main observations of prism adaptation experiments. Using standard system identification techniques, we fitted the model to data from a rehabilitation trial based on a novel rehabilitation approach based on virtual reality, involving reaching movements within an adaptive environment. Our results suggest that the model can be used to interpret data from individual subjects and to formulate testable hypotheses on the mechanisms of recovery and directions for treatment
Health related quality of life in COVID-19 survivors discharged from acute hospitals: results of a short-form 36-item survey [version 1; peer review: awaiting peer review]
Background: Health-related quality of life (HRQL) is important for
evaluating the impact of a disease in the longer term across the
physical and psychological domains of human functioning. The aim of
this study is to evaluate HRQL in COVID-19 survivors in Italy using the
short form 36-items questionnaire (SF-36).
Methods: This is an observational study involving adults discharged
home following a coronavirus disease 2019 (COVID-19)-related
hospital admission. Baseline demographic and clinical data including
the Cumulative Illness Rating Scale (CIRS) and the Hospital Anxiety
and Depression Scale (HADS) were collected. The validated Italian
version of SF-36 was administered cross-sectionally. The SF-36
contains eight scales measuring limitations in physical and social
functioning, the impact on roles and activities, fatigue, emotional wellbeing, pain and general health perception.
Results: A total of 35 patients, with a mean age of 60 years,
completed the SF-36. The results showed difficulties across the
physical and psychological domains, particularly affecting the return
to previous roles and activities. A higher burden of co-morbidities as
well as a more severe muscle weakness was associated to a lower
physical functioning. Younger age, rather than older, correlated to a
perceived greater limitation in physical functioning and vitality.
Conclusions: COVID-19 survivors particularly the ones of working age
may need support for resuming their premorbid level of functioning
and returning to work
Computer-based cognitive rehabilitation: the CoRe system
This work aims at providing a tool for supporting cognitive rehabilitation. This is a wide field, that includes a variety of diseases and related clinical pictures; for this reason the need arises to have a tool available that overcomes the difficulties entailed by what currently is the most common approach, that is, the so-called pen and paper rehabilitation. Methods: We first organized a big number of stimuli in an ontology that represents concepts, attributes and a set of relationships among concepts. Stimuli may be words, sounds, 2D and 3D images. Then, we developed an engine that automatically generates exercises by exploiting that ontology. The design of exercises has been carried on in synergy with neuropsychologists and speech therapists. Solutions have been devised aimed at personalizing the exercises according to both patients’ preferences and performance. Results: Exercises addressed to rehabilitation of executive functions and aphasia-related diseases have been implemented. The system has been tested on both healthy volunteers (n 1/4 38) and patients (n 1/4 9), obtaining a favourable rating and suggestions for improvements. Conclusions: We created a tool able to automate the execution of cognitive rehabilitation tasks. We hope the variety and personalization of exercises will allow to increase compliance, particularly from elderly people, usually neither familiar with technology nor particularly willing to rely on it. The next step involves the creation of a telerehabilitation tool, to allow therapy sessions to be undergone from home, thus guaranteeing continuity of care and advantages in terms of time and costs for the patients and the National Healthcare System (NHS).Postprint (published version
Computer-Assessed Preference-Based Quality of Life in Patients with Spinal Cord Injury
Objectives. Our aims were to (1) measure quality of life (QoL) in spinal cord injury (SCI) patients using different methods and analyze differences; (2) enable targeted treatments by identifying variables that affect QoL; and (3) provide decision-makers with useful data for cost-utility analyses in SCI population. Methods. Seventy-one participants were enrolled. The computer-based tool UceWeb was used to elicit QoL in terms of utility coefficients, through the standard gamble, time trade-off, and rating scale methods. The SF36 questionnaire was also administered. Statistical analyses were performed to find predictors of QoL among collected variables. Results. Median values for rating scale, time trade-off, and standard gamble were 0.60, 0.82, and 0.85, respectively. All scales were significantly correlated. Rating scale and SF36 provided similar values, significantly lower than the other methods. Impairment level, male gender, older age, living alone, and higher education were correlated with lower QoL but accounted for only 20% of the variation in utility coefficients. Conclusions. Demographic and clinical variables are useful to predict QoL but do not completely capture utility coefficients variability. Therefore, direct preference-based utility elicitation should be strengthened. Finally, this is the first study providing data that can be used as a reference for cost-utility analyses in the Italian SCI population
OFICINAS TEMÁTICAS SOBRE QUÍMICA E CIDADANIA: PESQUISA, ENSINO E EXTENSÃO
Este trabalho tem como objetivo relatar e discutir as atividades desenvolvidas em oficinas temáticas sobre Química e cidadania em um projeto de extensão da Universidade Federal de São Carlos, campus Araras. O projeto de extensão consistiu em elaborar e oferecer à comunidade em geral oficinas que relacionassem conhecimentos químicos a aspectos sociais, políticos, econômicos e ambientais dos temas química forense, cosméticos, alimentação e poluição ambiental. É relatado o desenvolvimento de quatro oficinas que contaram com diferentes estratégias e metodologias de ensino, pautadas na pesquisa em ensino de química e nos pressupostos da abordagem Ciência, Tecnologia e Sociedade. Os resultados apontam para a articulação entre ensino, pesquisa e extensão e para as contribuições na formação docente das monitoras envolvidas. Conclui-se que as atividades realizadas permitiram uma abordagem diferenciada dos conhecimentos químicos, despertando o interesse da comunidade externa e interna à universidade pelos temas tratados
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