529 research outputs found

    Rasch analysis of the Fatigue Severity Scale in Italian subjects with multiple sclerosis.

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    To perform a psychometric analysis of the Fatigue Severity Scale (FSS) using Rasch analysis in a sample of Italian subjects with multiple sclerosis

    Analysis of the Energy Consumption of a Novel DC Power Supplied Industrial Robot

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    The energy consumption and electrical characteristics of a novel direct current (DC) power supplied industrial robot prototype are compared and analyzed with a state of the art alternating current (AC) supplied industrial robot. An extensive set of experiments shows an important reduction of the total energy consumption for different electrical power profiles measured in various robot trajectories with specific working temperatures. The recuperated energy is also analyzed in the different scenarios. Experimental results show that a DC type robot can be up to 12.5% more energy-efficient than an equivalent AC type robot

    Physicochemical and biological properties of natural and synthetic C-22 and C-23 hydroxylated bile acids.

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    In order to define the effect of a side chain hydroxy group on bile acid (BA) physicochemical and biological properties, 23-hydroxylated bile acids were synthesized following a new efficient route involving the alpha-oxygenation of silylalkenes. 22-Hydroxylated bile acids were also studied. The synthesized bile acids included R and S epimers of 3 alpha,7 alpha,23-trihydroxy-5 beta-cholan-24-oic acid (23R epimer: phocaecholic acid), 3 alpha,12 alpha,23-trihydroxy-5 beta-cholan-24-oic (23R epimer: bitocholic acid), and 3 alpha,7 beta,23-trihydroxy-5 beta-cholan-24-oic acid. A 3 alpha,7 alpha,22-trihydroxy-5 beta-cholan-24-oic acid (haemulcholic acid) was also studied. The presence of a hydroxy group on the side chain slightly modified the physicochemical behavior in aqueous solution with respect to common BA: the critical micellar concentration (CMC) and the hydrophilicity were similar to naturally occurring trihydroxy BA such as cholic acid. The pKa value was lowered by 1.5 units with respect to common BA, being 3.8 for all the C-23 hydroxy BA. C-22 had a higher pKa (4.2) as a result of the increased distance of the hydroxy group from the carboxy group. When the C-23 hydroxylated BA were intravenously administered to bile fistula rats, they were efficiently recovered in bile (more than 80% unmodified) while the corresponding analogs, lacking the 23- hydroxy group, were almost completely glycine- or taurine-conjugated. On the other hand, the C-22 hydroxylated BA were extensively conjugated with taurine and less than 40% of the administered dose was secreted without being conjugated. In the presence of intestinal bacteria, they were mostly metabolized to the corresponding 7-dehydroxylated compound similar to common BA with the exception of bitocholic acid which was relatively stable. The presence of a hydroxy group at the C-23 position increased the acidity of the BA and this accounted for poor absorption within the biliary tree and efficient biliary secretion without the need for conjugation. 3 alpha,7 beta-23 R/S trihydroxy-5 beta-cholan-24-oic acids could improve the efficiency of ursodeoxycholic acid (UDCA) for gallstone dissolution or cholestatic syndrome therapy, as it is relatively hydrophilic and efficiently secreted into bile without altering the glycine and taurine hepatic pool

    The Golgi apparatus is a primary site of intracellular damage after photosensitization with Rose Bengal acetate

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    The aim of the present investigation was to elucidate whether the Golgi apparatus undergoes photodamage following administration of the fluorogenic substrates Rose Bengal acetate (RBAc) and irradiation at the appropriate wavelength. Human HeLa cells were treated in culture and the changes in the organization of the Golgi apparatus were studied using fluorescence confocal microscopy and electron microscopy, after immunocytochemical labeling. To see whether the cytoskeletal components primarily involved in vescicle traffic (i.e., microtubules) might also be affected, experiments of tubulin immunolabeling were performed. After treatment with RBAc and irradiation, cells were allowed to grow in drug-free medium for different times. 24hr after irradiation, the cisternae of the Golgi apparatus became packed, and after 48-72 hr they appeared more fragmented and scattered throughout the cytoplasm; these changes in the organization of the Golgi cisternae were confirmed at electron microscopy. Interestingly enough, apoptosis was found to occur especially 48-72h after irradiation, and apoptotic cells exhibited a dramatic fragmentation of the Golgi membranes. The immunolabeling with anti-tubulin antibody showed that microtubules were also affected by irradiation in RBAc-treated cells

    Online motion accuracy compensation of industrial servomechanisms using machine learning approaches

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    This paper addresses the crucial aspect of position error modeling and compensation in industrial servomechanisms with the aim to achieve accurate control and high-performance operation in industrial robots and automated production systems. The inherent complexity and nonlinear behavior of these modules, usually consisting of a servomotor and a speed reducer, often challenge traditional analytical modeling approaches. In response, the study extensively explores the design and implementation of Machine Learning (ML) algorithms to obtain a comprehensive model of the Transmission Error (TE) in rotating vector reducers, which is a main source of robot motion accuracy errors. The ML models are trained with experimental data obtained from a special purpose test rig, where the reducer is tested under different combinations of input speed, applied load and oil temperature. In the second part of the work, the resulting predictive model, tailored to capture the intricate dynamics of the analyzed reducer, is imported into a programmable logic controller to enable online compensation strategies during the execution of custom motion profiles. Experimental tests are conducted using two distinct motion profiles: one generated with a cycloidal law, typical of industrial machinery, and the other extrapolated from the joints of an industrial robot during a pick-and-place task. The results demonstrate the effectiveness of the proposed approach, enabling accurate prediction and substantial reductions (over 90%) in the overall reducer TE through the implemented predictive model

    The correlation between low back pain and strength training in elite athletes: a literature review

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    This study aims to analyze the correlation between LBP and elite athletes who practice sports where strength training intervenes via weightlifting. To analyse the correlation between low back pain and athletes who practice sports where strength training programs, a narrative review was conducted by two independent author through MEDLINE database search. Inclued study’s methodology quality has been evaluated using NIH quality assessment tool for Observational Cohort and Cross-Sectional Studies. Out of 830 retrieved articles, after titles, abstracts and full text assessment, four studies met the inclusion criteria and were included in the present narrative review. The NIH total score ranged from 10 to 12 points. Demographic and sport-specific factors can influence the prevalence of LBP. Our findings highlight the importance of developing future research to provide prevention programs to reduce the incidence of LBP, taking into account the demographics of athletes and the unique nature of their sport activity

    Autoimmune encephalitis and CSF anti-glur3 antibodies in an MS patient after alemtuzumab treatment

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    A 45-year-old Italian woman, affected by relapsing-remitting multiple sclerosis (RR-MS) starting from 2011, started treatment with alemtuzumab in July 2016. Nine months after the second infusion, she had an immune thrombocytopenic purpura (ITP) with complete recovery after steroid treatment. Three months after the ITP, the patient presented with transient aphasia, cognitive deficits, and focal epilepsy. Serial brain magnetic resonance imaging showed a pattern compatible with encephalitis. Autoantibodies to glutamate receptor 3 peptide A and B were detected in cerebrospinal fluid and serum, in the absence of any other diagnostic cues. After three courses of intravenous immunoglobulin (0.4 mg/kg/day for 5 days, 1 month apart), followed by boosters (0.4 mg/kg/day) every 4-6 weeks, her neurological status improved and is currently comparable with that preceding the encephalitis. Autoimmune complications of the central nervous system during alemtuzumab therapy are relatively rare: only one previous case of autoimmune encephalitis following alemtuzumab treatment has been reported to date

    Barriers to sEMG assessment during overground robot-assisted gait training in subacute stroke patients

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    Background: The limitation to the use of ElectroMyoGraphy (sEMG) in rehabilitation services is in contrast with its potential diagnostic capacity for rational planning and monitoring of the rehabilitation treatments, especially the overground Robot-Assisted Gait Training (o-RAGT). Objective: To assess the barriers to the implementation of a sEMG-based assessment protocol in a clinical context for evaluating the effects of o-RAGT in subacute stroke patients. Methods: Anobservationalstudywasconductedinarehabilitationhospital.Theprimary outcome was the success rate of the implementation of the sEMG-based assessment. The number of dropouts and the motivations have been registered. A detailed report on difficulties in implementing the sEMG protocol has been edited for each patient. The educational level and the working status of the staff have been registered.Each member of staff completed a brief survey indicating their level of knowledge of sEMG, using a five-point Likert scale. Results: The sEMG protocol was carried out by a multidisciplinary team composed of Physical Therapists (PTs) and Biomedical Engineers (BEs). Indeed, the educational level andtheexpertiseofthemembersofstaffinfluencedthefulfillmentoftheimplementation of the study.ThePTsinvolved in the study did not receive any for maleducationonsEMG during their course of study. The low success rate (22.7%) of the protocol was caused by several factors which could be grouped in: patient-related barriers; cultural barriers; technical barriers; and administrative barriers. Conclusions: Since a series of barriers limited the use of sEMG in the clinical rehabilitative environment, concrete actions are needed for disseminating sEMG in rehabilitation services. The sEMG assessment should be included in health systems regulations and specific education should be part of the rehabilitation professionals’ curriculum. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03395717

    Regional Precuneus Cortical Hyperexcitability in Alzheimer's Disease Patients

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    Objective: Neuronal excitation/inhibition (E/I) imbalance is a potential cause of neuronal network malfunctioning in Alzheimer's disease (AD), contributing to cognitive dysfunction. Here, we used a novel approach combining transcranial magnetic stimulation (TMS) and electroencephalography (EEG) to probe cortical excitability in different brain areas known to be directly involved in AD pathology. Methods: We performed TMS-EEG recordings targeting the left dorsolateral prefrontal cortex (l-DLPFC), the left posterior parietal cortex (l-PPC), and the precuneus (PC) in a large sample of patients with mild-to-moderate AD (n = 65) that were compared with a group of age-matched healthy controls (n = 21). Results: We found that patients with AD are characterized by a regional cortical hyperexcitability in the PC and, to some extent, in the frontal lobe, as measured by TMS-evoked potentials. Notably, cortical excitability assessed over the l-PPC was comparable between the 2 groups. Furthermore, we found that the individual level of PC excitability was associated with the level of cognitive impairment, as measured with Mini-Mental State Examination, and with corticospinal fluid levels of Aβ42 . Interpretation: Our data provide novel evidence that precuneus cortical hyperexcitability is a key feature of synaptic dysfunction in patients with AD. The current results point to the combined approach of TMS and EEG as a novel promising technique to measure hyperexcitability in patients with AD. This index could represent a useful biomarker to stage disease severity and evaluate response to novel therapies. ANN NEUROL 2022
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