97 research outputs found
Logopenic and nonfluent variants of primary progressive aphasia are differentiated by acoustic measures of speech production
Differentiation of logopenic (lvPPA) and nonfluent/agrammatic (nfvPPA) variants of Primary Progressive Aphasia is important yet remains challenging since it hinges on expert based evaluation of speech and language production. In this study acoustic measures of speech in conjunction with voxel-based morphometry were used to determine the success of the measures as an adjunct to diagnosis and to explore the neural basis of apraxia of speech in nfvPPA. Forty-one patients (21 lvPPA, 20 nfvPPA) were recruited from a consecutive sample with suspected frontotemporal dementia. Patients were diagnosed using the current gold-standard of expert perceptual judgment, based on presence/absence of particular speech features during speaking tasks. Seventeen healthy age-matched adults served as controls. MRI scans were available for 11 control and 37 PPA cases; 23 of the PPA cases underwent amyloid ligand PET imaging. Measures, corresponding to perceptual features of apraxia of speech, were periods of silence during reading and relative vowel duration and intensity in polysyllable word repetition. Discriminant function analyses revealed that a measure of relative vowel duration differentiated nfvPPA cases from both control and lvPPA cases (r2 = 0.47) with 88% agreement with expert judgment of presence of apraxia of speech in nfvPPA cases. VBM analysis showed that relative vowel duration covaried with grey matter intensity in areas critical for speech motor planning and programming: precentral gyrus, supplementary motor area and inferior frontal gyrus bilaterally, only affected in the nfvPPA group. This bilateral involvement of frontal speech networks in nfvPPA potentially affects access to compensatory mechanisms involving right hemisphere homologues. Measures of silences during reading also discriminated the PPA and control groups, but did not increase predictive accuracy. Findings suggest that a measure of relative vowel duration from of a polysyllable word repetition task may be sufficient for detecting most cases of apraxia of speech and distinguishing between nfvPPA and lvPPA
Primary progressive aphasia: a clinical approach
This work was supported by the Alzheimer’s Society (AS-PG-16-007), the National Institute for Health Research University College London Hospitals Biomedical Research Centre and the UCL Leonard Wolfson Experimental Neurology Centre (PR/ylr/18575). Individual authors were supported by the Leonard Wolfson Foundation (Clinical Research Fellowship to CRM), the National Institute for Health Research (NIHR Doctoral Training Fellowship to AV), the National Brain Appeal–Frontotemporal Dementia Research Fund (CNC) and the Medical Research Council (PhD Studentships to CJDH and RLB, MRC Research Training Fellowship to PDF, MRC Clinician Scientist to JDR). MNR and NCF are NIHR Senior Investigators. SJC is supported by Grants from ESRC-NIHR (ES/L001810/1), EPSRC (EP/M006093/1) and Wellcome Trust (200783). JDW was supported by a Wellcome Trust Senior Research Fellowship in Clinical Science (091673/Z/10/Z)
Lead (Pb2+) Removal from Synthetic Aqueous Solution Using Food Waste Ash
Lead (Pb2+) Removal from Synthetic Aqueous Solution Using Food Waste Ash
AfsharniaM (Ph.D)1, Shams M (M.Sc)2, Sajjadi SA (Ph.D)1, Qasemi M (M.Sc)3
1. Assistant Professor, Department of Environmental Health Engineering, ,Gonabad University of Medical Sciences, Gonabad, Iran.
2. Instructor, Department of Environmental Health Engineering, Gonabad University of Medical Sciences, Gonabad, Iran.
3. Corresponding Author: M.Sc Student in Environmental Health Engineering, Gonabad University of Medical Sciences, Gonabad, Iran
Abstract
Introduction: Lead is a toxic heavy metal in some industrial wastewater that can pose hazards to the environment and human health. Adsorption is a promising technology for decontamination of water. The present study evaluated the efficiency of food waste ash as a cheap, environmental compatible and available adsorbent, in lead removal from synthetic aqueous solution.
Methods: In the presentexperimental study, lead removal by using food waste ash in series of batch experiments were investigated. The influence of different parameters on adsorption such as adsorbent dose, contact time, pH, lead concentrationand adsorption temperature also studied. The experimental data finally were analyzed using excel and the adsorption behavior was fitted to isotherm and kinetic models.
Results: The study showed that lead removal decreased with increasing lead concentration. In addition, it was found that lead adsorption increased by increasing pH and temperature. comparing adsorption capacity of food waste ash with the adsorbents used by scientist also showed the former have a remarkable higher capacity toward lead adsorption. The adsorption process also showed a good conformity to Freundlich model.
Conclusion: Current study endorsed the use of food waste ash in real adsorption systems, as a cheap and available adsorbent with high capacity toward lead
Recommended from our members
Differential associations of amyloid and tau (from PET) with brain volumes (from MRI) by cognitive status
Background: Alzheimer’s disease pathology (AD) is an important cause of neurodegeneration and brain atrophy. Non-AD mechanisms can also cause neurodegeneration alone or in conjunction with AD. Harboring combination of AD and non-AD pathologies leads to greater cognitive impairment and dementia. Here, we examined the hypothesis that the association of amyloid and tau burden from positron emission tomography (PET) with brain volumes from magnetic resonance imaging (MRI) is weaker in those with dementia compared to those with mild cognitive impairment (MCI) or normal cognition. Method: We used data from participants in the Alzheimer’s Disease Neuroimaging Initiative (ADNI) who had either florbetapir amyloid PET (N=1320) of flortaucipir tau PET (N=833, 535 of whom had both). We examined the association between volumes of brain structures (FreeSurfer-v7) and standardized uptake value ratios (SUVr) for amyloid (summary cortical region, normalized to whole cerebellum) and tau (meta-temporal region, normalized to inferior cerebellar gray matter) separately, using linear regressions adjusting for age, sex, and education. We report results in overall groups and by cognitive status (normal, MCI, dementia). We display semi-partial correlations (sr, thresholded at Puncorrected<0.05), as measures of effect size. Result: Table-1 summarizes participant characteristics. The effect of amyloid on brain volumes was modest in the overall cohort, with associations strongest for inferior/middle temporal, inferior parietal, entorhinal, hippocampus, and amygdala regions (sr∼-0.2, P<0.001 all). In those with dementia, however, there were no distinct associations between amyloid and brain atrophy (Figure-1). For tau, associations in the overall cohort were similarly strongest for inferior/middle temporal, inferior parietal, entorhinal, hippocampus, and amygdala regions (sr∼-0.3, P<0.001 all). In those with dementia, associations remained strong for inferior/middle temporal regions (sr∼-0.3, P<0.001) but tau was not associated with hippocampus volumes (left, sr=-0.05, P=0.6; right, sr=-0.12, P=0.14, Figure-2); this divergence is further highlighted in select regions (inferior temporal and hippocampus) in Figure-3. Conclusion: We found that the relationship between amyloid and tau burden and atrophy was stronger in the overall cohort than in participants with dementia. This was particularly the case for medial temporal lobe structures. The effect of non-AD pathologies on medial temporal lobe atrophy is a potential explanation for the observed results
Isolation of Acanthamoeba Spp. from Drinking Waters in Several Hospitals of Iran
Background: Acanthamoeba is an opportunistic amphizoic protozoan found in different water sources including swimming pool as well as in sewage. The aim of this study was to investigate the prevalence of Acanthamoeba in tap-water samples in Iran.Method: In this descriptive cross-sectional study, 94 samples of cold and warm tap-water were collected from different wards of hospitals in 13 cities of Iran in 2007-2008. Free residual chlorine, pH, and temperature of samples were measured. After filtration through multipore nylon membrane, samples were cultured on non-nutrient agar. Then we investigated existence of Acanthamoeba by reverse contrast phase microscope.Results: Acanthamoeba was found in 45 samples (48%). Thirty-four and 11 positive samples were collected from cold and warm tap water, respectively. The samples belonged to the category of 20-30 °C temperature with 0-2 ppm free residual chlorine and pH 6-7.4 showed the most coincidence to the positive cases. The greatest proportion of positive samples was obtained from Mashhad hospitals, while all samples collected from Arak and Semnan hospitals were negative.Conclusion: considering the results of this study and the pathogenic role of this protozoan on patients with immunodeficiency, as well as capability of this microorganism in carrying other pathogens such as Legionella, further studies are needed. What is more important, potable water in hospitals should follow the procedure of treatment and sanitation, in order to prevent the relevant nosocomial infections
On the fabrication of functional graded 3Y-PSZ/316L materials by SPS: Process optimization and characterization of the obtained products
Dense and crack free six-layered functional graded materials were successfully produced by Spark Plasma Sintering by combining 3 mol% Y2O3-partially stabilized ZrO2 (3Y-PSZ) and 316L stainless steel. All the sintered products consisted of a steel free layer on one side and a cermet composite containing 50 vol% of both constituents on the opposite side. Conversely, the stainless steel concentration in the interlayers was progressively changed following diverse spatial profiles. It was found that the temperature interval from 1080 to 1180 °C required for the full consolidation from the 50 vol% composite layer to the 3Y-PSZ one, respectively, can be reached when adopting a specific die configuration where the cross section was varied from 30 to 28 mm, respectively. Correspondingly, the densification level of each layer, as well as the related hardness and fracture toughness properties, were highly enhanced with respect to the standard cylindrical die. In addition, a significant improvement of the material toughness was obtained when the material concentration exponent was decreased from 2 to 1, whereas this effect tends to vanish when such parameter was further reduced to 0.5
- …