73 research outputs found
High-order geometric integrators for the variational Gaussian approximation
Among the single-trajectory Gaussian-based methods for solving the
time-dependent Schr\"{o}dinger equation, the variational Gaussian approximation
is the most accurate one. In contrast to Heller's original thawed Gaussian
approximation, it is symplectic, conserves energy exactly, and may partially
account for tunneling. However, the variational method is also much more
expensive. To improve its efficiency, we symmetrically compose the second-order
symplectic integrator of Faou and Lubich and obtain geometric integrators that
can achieve an arbitrary even order of convergence in the time step. We
demonstrate that the high-order integrators can speed up convergence
drastically compared to the second-order algorithm and, in contrast to the
popular fourth-order Runge-Kutta method, are time-reversible and conserve the
norm and the symplectic structure exactly, regardless of the time step. To show
that the method is not restricted to low-dimensional systems, we perform most
of the analysis on a non-separable twenty-dimensional model of coupled Morse
oscillators. We also show that the variational method may capture tunneling
and, in general, improves accuracy over the non-variational thawed Gaussian
approximation.Comment: 17 pages, 11 figure
The effect of massage on pain intensity in patients with knee surgery by Arthroscopy technique
Background: Pain as a main social problem has involved millions of people. Surface massag is one of the
effective ways for reducing pain after surgery. The aim of this study was to evaluate the effect of surface
massage technique on pain intensity in knee surgery patients with Arthroscopy technique.
Material and Methods: This is a clinical trial study on 60 Knee surgery patientsSamples were selected
using conveniencecontinuity method and then they were randomly divided into intervention and control
groups. In intervention group, besides routine treatments, patients were taking surface massage technique by
the researcher for 20 minutes each day and pain severity was evaluated before and after the surface stroking
technique. Control group received only routine medical care and pain severity was evaluated in first and after
20 minutes. Data was analyzed by presenting descriptive and inferential statistics with using SPSS version 15
software.
Results: Results showed that there was a statistical different between mean score of pain severity before and
after surface massage in intervention group (p <0.001) but this difference wasn't meaningful in control group
(p=0.32).
Conclusion: Considering surface massage as a safe and effective intervention, it could be used as an easy,
cheap and executable method for treating pain in all medical health care centers and even at patient's home
Association of Emotional Intelligence and Professional Socialization in Operating Room Students
Background & Aims: Socialization is a constant process throughout human life. The enhancers of socialization
must be identified in order to promote this process. The present study aimed to investigate the correlation
between the emotional intelligence and professional socialization of the operating room students at Isfahan
University of Medical Sciences, Iran.
Materials & Methods: This cross-sectional, correlational study was conducted on 93 operating room students
at Isfahan University of Medical Sciences after determining the sample size. Data were collected using a
demographic questionnaire, Shirring and Siberia self-report questionnaire of emotional intelligence, and
professional socialization questionnaire by Toit. Data analysis was performed in SPSS version 16 using
descriptive and inferential statistics.
Results: The results of Pearson’s correlation-coefficient indicated direct correlations between the professional
socialization of students and the total score of emotional intelligence (P=0.04), social component (P<0.001),
empathy (P=0.04), and self-awareness (P=0.045). However, no significant associations were observed between
emotional intelligence and the other components (P>0.05).
Conclusion: According to the results, it seems that the professional socialization of operating room students is
remarkably influenced by emotional intelligence and the level of learning in the academic environment. Given
the importance of intelligence and socialization in the clinical environment and comprehensive patient care,
clinical students must be adequately trained on emotional intelligence skills
Rituximab and risk of COVID-19 infection and its severity in patients with MS and NMOSD
Background: Choosing a safe disease modifying therapy during the COVID-19 pandemic is challenging. This case series study was conducted to determine the incidence rate and the course of Covid-19 infection in MS/NMOSD patients treated with Rituximab. Methods: In this study, we designed a web-based questionnaire. Baseline information such as patient- reported walking disability, total number of Rituximab infusions received, delayed injections, occurrence of any relapse, and the use of corticosteroids during the pandemic were collected. Also, information regarding the Covid-19 pandemic such as adherence to self-isolation, any recent exposure to an infected individual and the presence of suggestive symptoms were collected. In case of positive test results, patients were grouped into 2 categories; mild to moderate and seriously ill and outcomes were evaluated as favorable (improved/ discharged) and unfavorable (expired). Results: Two hundred fifty-eight patients with Multiple Sclerosis were enrolled in this study, 9 of the subjects (3.4) were confirmed positive for Covid-19, five of which required hospitalizations (55.5), two patients required ICU admission (22.2) and 2 two patients died (22.2). None of these patients ever mentioned using corticosteroids during the pandemic. In comparison to MS patients who were not receiving disease modifying therapy (DMT), our study indicated a higher incidence of Covid-19 infection, higher ratio of serious illness and a higher fatality ratio. Conclusions: Rituximab seems not to be safe enough during the pandemic. © 2021, The Author(s)
ExploreASL: an image processing pipeline for multi-center ASL perfusion MRI studies
Arterial spin labeling (ASL) has undergone significant development since its inception, with a focus on improving standardization and reproducibility of its acquisition and quantification. In a community-wide effort towards robust and reproducible clinical ASL image processing, we developed the software package ExploreASL, allowing standardized analyses across centers and scanners. The procedures used in ExploreASL capitalize on published image processing advancements and address the challenges of multi-center datasets with scanner-specific processing and artifact reduction to limit patient exclusion. ExploreASL is self-contained, written in MATLAB and based on Statistical Parameter Mapping (SPM) and runs on multiple operating systems. To facilitate collaboration and data-exchange, the toolbox follows several standards and recommendations for data structure, provenance, and best analysis practice. ExploreASL was iteratively refined and tested in the analysis of >10,000 ASL scans using different pulse-sequences in a variety of clinical populations, resulting in four processing modules: Import, Structural, ASL, and Population that perform tasks, respectively, for data curation, structural and ASL image processing and quality control, and finally preparing the results for statistical analyses on both single-subject and group level. We illustrate ExploreASL processing results from three cohorts: perinatally HIV-infected children, healthy adults, and elderly at risk for neurodegenerative disease. We show the reproducibility for each cohort when processed at different centers with different operating systems and MATLAB versions, and its effects on the quantification of gray matter cerebral blood flow. ExploreASL facilitates the standardization of image processing and quality control, allowing the pooling of cohorts which may increase statistical power and discover between-group perfusion differences. Ultimately, this workflow may advance ASL for wider adoption in clinical studies, trials, and practice
The prevalence of potentially beneficial and harmful drug-drug interactions in intensive care units
Background The present study was conducted with the aim of investigating the prevalence of potentially beneficial and harmful drug-drug interactions (DDIs) in intensive care units (ICUs). Methods The present cross-sectional prospective study was conducted in two ICUs in Shahr-e Kord city, Iran. The study sample was consisted of 300 patients. The Drug Interaction Facts reference text book [Tatro DS. Drug interaction facts. St Louis, MO: Walters Kluwer Health, 2010.] was used to determine the type and the frequency of the DDIs. Results The participants consisted of 189 patients men and 111 women. The mean age of patients was 44.2 ± 24.6 years. Totally, 60.5% of patients had at least one drug-drug interaction in their profile. The total number of DDIs found was 663 (the mean of the total number of drug-drug interactions was 2.4 interactions per patient). Of all the 663 interactions, 574 were harmful and others were beneficial. In terms of starting time, 98 of the potential interactions were rapid and 565 of them were delayed. In terms of severity, 511 of the potential interactions were moderate. Some of the drugs in the patients' medical records including phenytoin, dopamine, ranitidine, corticosteroid, dopamine, heparin, midazolam, aspirin, magnesium, calcium gluconate, and antibiotics, the type of ventilation, the type of nutrition and the duration of hospital stay were among the factors that were associated with high risk of potential DDIs (p < 0.05). Conclusions The prevalence of potentially beneficial and harmful DDIs, especially harmful drug-drug interactions, is high in ICUs and it is necessary to reduce these interactions by implementing appropriate programs and interventions
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