In the paper, a research programme focused on determination of steel fibre dispersion in self-compacting concrete using the X-ray computed tomography method is presented. Large scale specimens were cast (in the form of walls 1.2 m 9 1.2 m 9 0.15 m), containing different types of steel fibre. The tests were conducted on beam specimens cut from each wall. Both traditional destructive tests (compressive strength, three point bending) and non-destructive tests (X-ray computed tomography imaging followed by image analysis) were performed. The X-ray computed tomography method allowed to precisely determine fibre dispersion in the whole volume of the walls. These results were compared with mechanical properties of cut beams and their original location in the walls. Differences in fibre volume and dispersion between top and bottom parts of the walls were observed. The influence of the fibre type and the casting point location was also significant. Longer fibres became more effectively orientated in parallel to the bending loading direction, resulting in enhancement of the mechanical properties of the concrete. Tests on 16 beams (cut from each wall), through load-deflection relations, provided a thorough picture of mechanical uniformity of the material properties inside the walls. The X-ray computed tomography imaging proved to be intuitive and accurate in the assessment of steel fibre dispersion.
Clinical and biological assessment of the COVID-19 vaccine efficacy in the frail population is of crucial importance. The study focuses on measuring the levels of anti-SARS-CoV-2 IgG antibodies before and after BNT162b2 mRNA COVID-19 vaccination among long-term care facility (LTCF) elderly residents. We conducted a prospective, single-center, observational study among LTCF residents. The study protocol was based on three blood sample acquisitions: first taken at baseline—5 days before the first dose of the vaccine, second—20 days after the first dose, and third—12 days after the second shot of the vaccine. The comparison was made for two cohorts: patients with and without prior COVID-19 infection. The data was collected from January to March 2021. A total number of 78 LTCF residents (55 women and 23 men) aged 62–104, 85.72 ± 7.59 years (mean ± SD), were enrolled in the study. All study participants were investigated for the presence of SARS-CoV-2 anti-spike (S) protein IgG, using a chemiluminescent immunoassay. Frailty was assessed with the Clinical Frailty Scale. Among elderly COVID-19 survivors in LTCF, a single dose of vaccine significantly increased anti-SARS-CoV-2 IgG antibody levels. IgG concentration after a single and double dose was comparable, which may suggest that elderly COVID-19 survivors do not require a second dose of vaccine. For residents without a previous history of COVID-19, two doses are needed to achieve an effective serological response. The level of anti-SARS-CoV-2 IgG antibodies after vaccination with BNT162b2 mRNA COVID-19 did not correlate with the frailty and age of the studied individuals.
Deficiency in dopaminergic system function may be one of the hypothetical reasons of the frailty syndrome but its role still remains unclear. The aim of our study was to assess the frailty phenotype prevalence in geriatric inpatients with mild parkinsonian signs (MPS) and to investigate levodopa test in the frail patients with MPS. We examined 118 participants: 90 with MPS and 28 in control group (without MPS). The frailty syndrome presence was evaluated by the Fried criteria. Deficiency in dopaminergic system function was assessed by one of the modifications of an acute levodopa challenge test (LCT): in MPS group every patient was examined by performing Up and Go Test and also Step Test before and 3 h after taking 125 mg of Madopar (levodopa + benserazide). Sixty-nine study subjects (58%) met criteria for frailty. Fifty-five participants in MPS group (61.1% of MPS group) and fourteen (50%) in control group. All of the patients that scored positive in walk speed criterion of frailty were frail. When all MPS patients were considered, the number of components scored positive for frailty was directly related to the walk speed (r = -0.70, p < 0.0001). In MPS group LCT scores were significantly higher for frailty patients compared to non-frailty (p = 0.0027). When all MPS patients were considered, the number of components scored positive for frailty was directly related LCT score (r = 0.37, p = 0.0004). There was a relationship between LCT and walk speed (r = -0.31, p = 0.0032). Our observations provide new information about the relationship between frailty and MPS, suggest the need for increased awareness of frailty in MPS patients and conversely. Our study provides data for a discussion on pathophysiological background of the frailty syndrome (FS), emphasizing the theories of the important impact of dopaminergic system deficit and encourages further research on the role of LCT in measuring it.
Background
Children and adolescents with intellectual disabilities (IDs) are an identified group with postural disturbances resulting from a lack of integration among the visual, vestibular and proprioceptive systems. The insufficient level of maturity of the sensory systems is at least partly responsible for disturbances in maintaining body balance. More sway can increase the risk of falls and body injuries. The aims of the study were (1) to compare the ability to maintain the body balance of children and youth with a varying degree of ID, both with the eyes open and closed, and (2) to determine to what extent factors such as sex, level of ID, visual stimulus and body height independently affect the ability to maintain body balance in children and adolescents with ID.
Method
The study involved 131 people aged 13–21 years (65 girls and 66 boys). The participants were classified as (1) with mild disability (42 girls and 47 boys) and (2) with moderate disability (23 girls and 19 boys), based on IQ test results. Sway measures were collected with the Zebris platform, with the eyes open and closed. Sway path, sway path in anterio‐posterior and medio‐lateral directions and sway area were analysed.
Results
Boys with moderate ID were characterised by a significantly more sway indicating their worse postural balance ability than boys with mild ID, both in the trials with open eyes and closed ones. The type of test (eyes open/eyes closed) to a small extent had influenced the body balance of the examined children with ID. Results of analyses of covariance had showed that all analysed factors (sex, level of ID, type of the test performance and body height), irrespectively from direction of sway (sway path in anterio‐posterior and medio‐lateral directions), worked independently influencing body balance.
Conclusions
It could be assumed that lower height, moderate disability and male sex are factors significantly reducing ability of maintenance of balance of children and youth with ID.
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