Search results for "Complex."
showing 10 items of 5824 documents
Model order effects on ICA of resting-state complex-valued fMRI data : application to schizophrenia
2018
Abstract Background Component splitting at higher model orders is a widely accepted finding for independent component analysis (ICA) of functional magnetic resonance imaging (fMRI) data. However, our recent study found that intact components occurred with subcomponents at higher model orders. New method This study investigated model order effects on ICA of resting-state complex-valued fMRI data from 82 subjects, which included 40 healthy controls (HCs) and 42 schizophrenia patients. In addition, we explored underlying causes for distinct component splitting between complex-valued data and magnitude-only data by examining model order effects on ICA of phase fMRI data. A best run selection me…
Aids in sicily: Prevalence of antibodies to human immunodeficiency virus (HIV) in low and high risk groups
1987
A seroepidemiological survey, carried out to evaluate the prevalence of antibodies to HIV in patients with ARC and in healthy individuals at risk for AIDS, showed the infection to be widespread in the groups at risk, namely in drug abusers and hemophiliacs. However, remarkable difference existed between the prevalence of antibodies to HIV in drug abusers of the city of Palermo and those of other Sicilian provinces. Spread of the virus among Sicilian thalassemics, however, was very low and quite similar in all geographic areas. Antibodies were found very rarely (0.06%) in unpaid voluntary blood donors. The spread of the virus is still confined in high risk groups, and the major part of the s…
Rasch validation of the Depression Scale among patients with low back pain.
2020
BACKGROUND: The Depression Scale (DEPS) is a commonly used screening tool for major depression in studies investigating low back pain, yet it has not been validated for patients with back-specific problems. OBJECTIVE: To assess the psychometric properties of the DEPS in patients with degenerative spinal disease. METHODS: Six hundred and thirty-seven patients with a degenerative spinal disease completed the DEPS instrument. The Rasch Measurement Theory was applied to analyze the measurement properties of the DEPS. The main hypothesis-driven approach was whether the DEPS would meet relevant psychometric criteria for assessing depressive symptoms among patients with degenerative spinal disease…
The keyhole concept in aneurysm surgery: results of the past 20 years.
2011
Item does not contain fulltext BACKGROUND: Improvements in preoperative imaging and intraoperative visualization have led to a refinement in surgical techniques. OBJECTIVE: Report of a 20-year experience with application of the keyhole technique as a contribution to the ongoing debate on the impact of limited craniotomies in aneurysm surgery. METHODS: Over a 20-year period, 1000 consecutive patients with 1297 aneurysms were surgically treated in 1062 operations: 651 in the acute stage after SAH and 411 with unruptured aneurysms. The outcome was assessed with the modified Rankin scale and approach-related complications. RESULTS: The majority of the cases were treated by 4 different keyhole a…
Influence of age on the interrelation between EEG frequency bands during NREM and REM sleep.
2004
The age-dependence of temporal interrelations between distinct frequency bands of sleep EEG was investigated in a group of 59 healthy young and middle-aged males via cross correlation analysis. Based on global evaluation throughout the entire night, a highly significant decline of the delta/theta correlation with increasing age was found. A separate analysis for non-rapid eye movement (NREM) and rapid eye movement (REM) sleep revealed different changes with aging. During NREM sleep, the correlation between the delta and theta frequency bands decreased with increasing age. In contrast, during REM sleep, a stronger correlation became obvious between the theta, alpha, and beta frequency bands …
Epidemiological survey of 214 families with bladder exstrophy-epispadias complex.
2007
We sought to identify causative nongenetic and genetic risk factors for the bladder exstrophy-epispadias complex.A total of 237 families with the bladder exstrophy-epispadias complex were invited to participate in the study, and information was obtained from 214 families, mainly from European countries.Two families showed familial occurrence. Male predominance was found among all subgroups comprising epispadias, classic bladder exstrophy and cloacal exstrophy, with male-to-female ratios of 1.4:1, 2.8:1 and 2.0:1, respectively (p = 0.001). No association with parental age, maternal reproductive history or periconceptional maternal exposure to alcohol, drugs, chemical noxae, radiation or infe…
Complex regional pain syndrome: evidence for warm and cold subtypes in a large prospective clinical sample.
2016
Limited research suggests that there may be Warm complex regional pain syndrome (CRPS) and Cold CRPS subtypes, with inflammatory mechanisms contributing most strongly to the former. This study for the first time used an unbiased statistical pattern recognition technique to evaluate whether distinct Warm vs Cold CRPS subtypes can be discerned in the clinical population. An international, multisite study was conducted using standardized procedures to evaluate signs and symptoms in 152 patients with clinical CRPS at baseline, with 3-month follow-up evaluations in 112 of these patients. Two-step cluster analysis using automated cluster selection identified a 2-cluster solution as optimal. Resul…
The effect of radiofrequency catheter ablation of frequent premature ventricular complexes and arrhythmia burden on left ventricular function
2016
Background: Frequent premature ventricular complexes (PVC) are related to reversible tachycardia-induced cardiomyopathy. However, the role of arrhythmia burden on the outcome of the catheter ablation has not been fully recognised. Aim: The aim of this study was to assess the effect of catheter ablation and PVC burden in patients with and without structural heart disease (SHD) on left ventricular ejection fraction (LVEF). Methods: Transthoracic echocardiography was done before and six months after radiofrequency catheter ablation in 109 consecutive patients (61 men, age 55 ± 17 years) with frequent PVCs. Sixty-five (59.6%) patients had underlying SHD. Results: The catheter ablation procedure…
Immunological study of Melkersson-Rosenthal syndrome. Lack of response to food additive challenge
1995
Summary A study was made of six patients with Melkersson-Rosenthal syndrome (MRS) to establish the aetiological role of foodstuffs and/or additives and the possible associated immunological alterations. In all cases Melkersson-Rosenthal syndrome (MRS) was diagnosed both clinically and histologically, excluding other causes of orofacial granulomatosis (OFG). A detailed study of possible triggering factors was performed in all patients. Blood analysis, x-rays and cultures, were always within normal limits, with the exception of the finding of circulating immune complexes (CICs) in three patients with facial palsy associated, and C-reactive protein positivity in two patients who presented pers…
Association between platelet glycoprotein Ib-alpha and myocardial infarction: results of a pilot study performed in male and female patients from Sic…
2007
Myocardial infarction (AMI) is a complex multifactorial disorder. Platelet adhesion and thrombosis are pivotal events in the development of atherosclerotic lesions. Occlusive thrombus is almost exclusively initiated by plaque rupture and adhesion of platelets to subendothelial von Willebrand factor (vWf) by its specific platelet receptor, the alpha-chain of glycoprotein (GP) Ib-IX-V complex of the human platelet-specific antigens (HPA). Two polymorphisms have been reported in the sequence of GPIb-alpha. The first, a C/T transition at nucleotide 1018 results in an amino acid dimorphism (Thr/Met) at residue 145 of GPIb-alpha, which is located within the vWF-binding domain of the receptor. The…