497 research outputs found
Stroke care during the COVID-19 pandemic : experience from three large European countries
In order to cope with the exponentially increasing number of patients infected with SARS-CoV-2, European countries made enormous efforts to reorganize medical assistance and several diseases, including stroke, were particularly impacted. We report the experience of stroke neurologists from three European countries (Italy, France and Germany) that faced the pandemic at diverse time points and with different approaches, depending on their resources and healthcare system organization. Pre-hospital and in-hospital acute stroke pathways were reorganized to prioritize COVID-19 management and, in severely affected regions of Italy and France, stroke care was centralized to a limited number of centers, whereas the remaining stroke units were dedicated to patients with COVID-19. Access to acute stroke diagnostics and time-dependent therapies was limited or delayed because of reduced capacities of emergency services due to the burden of patients with COVID-19. A marked reduction in the number of patients presenting with transient ischaemic attack and stroke was noted in the emergency departments of all three countries. Although we only have preliminary data, these conditions may have affected stroke outcome. These indirect effects of the COVID-19 pandemic could negate the efforts of stroke neurologists over the last few years to improve outcome and reduce mortality of stroke patients. Although the SARS-CoV-2 infection rate is slowing down in Europe, the effects of ending lockdown in the next months are unpredictable. It is important for the European and world stroke community to share what has been learned so far to be plan strategies to ensure stroke care in the future and upcoming challenging times
Brain atrophy accelerates cognitive decline in cerebral small vessel disease: The LADIS study
Objective: To examine the independent contributions and combined interactions of medial temporal lobe atrophy (MTA), cortical and subcortical atrophy, and white matter lesion (WML) volume in longitudinal cognitive performance. Methods: A total of 477 subjects with age-relatedWMLwere evaluated with brain MRI and annual neuropsychological examinations in 3-year follow-up. Baseline MRI determinants of cognitive decline were analyzed with linear mixed models controlling for multiple confounders. Results: MTA and subcortical atrophy predicted significantly steeper rate of decline in global cognitive measures as well as compound scores for psychomotor speed, executive functions, and memory after adjusting for age, gender, education, lacunes/infarcts, and WML volume. Cortical atrophy independently predicted decline in psychomotor speed. WML volume remained significantly associated with cognitive decline even after controlling for the atrophy scores. Moreover, significant synergistic interactions were found between WML and atrophy measures in overall cognitive performance across time and the rate of cognitive decline. Synergistic effects were also observed between baseline lacunar infarcts and all atrophy measures on change in psychomotor speed. The main results remained robust after exclusion of subjects with clinical stroke or incident dementia, and after additional adjustments for progression of WML and lacunes. Conclusions: Brain atrophy and WML are independently related to longitudinal cognitive decline in small vessel disease. MTA, subcortical, and cortical atrophy seem to potentiate the effect ofWML and lacunes on cognitive decline
REAPROVEITAMENTO DA ÁGUA UTILIZADA NA LAVAGEM DE CANA DE AÇÚCAR ALIADO AO SEPARADOR SÓLIDO-LÍQUIDO PARA REMOÇÃO DE PARTICULADOS APLICADO A INDÚSTRIA SUCROALCOOLEIRA
Nas usinas sucroalcooleiras há diversos processos desde o recebimento da cana-de-açúcar, lavagem, moagem, separação do bagaço, destilação, até a finalização dos produtos. Dentre as diferentes etapas, destaca-se o processo de lavagem da cana-de-açúcar, pela alta demanda de recurso hídricos, correspondente a cerca de 25% do consumo de água na produção, acarretando custos consideráveis para captação de água e de outorga. Assim, reutilizar água do processo de lavagem é de grande importância para aumentar a eficiência e reduzir custos de produção. A recirculação da água de lavagem da cana (ALC) requer tratamentos para manutenção da qualidade da água, como também para eliminação de partículas capazes de provocar desgaste nas bombas e tubulações, através da extração do material sólido particulado (areia, terra e outros). Este trabalho é parte do projeto de pesquisa que visa estudar e desenvolver um separador sólido-líquido do tipo ciclone (desarenador) e tem como objetivos realizar uma revisão bibliográfica dos sistemas utilizados no tratamento da água de lavagem da cana nas indústrias, e os equipamentos e ensaios de laboratório para otimização destes tratamentos. PALAVRAS-CHAVE: separação sólido-líquido; lavagem de cana; reciclo; sedimentação primária
Mechanisms of Cognitive Impairment in Cerebral Small Vessel Disease: Multimodal MRI Results from the St George's Cognition and Neuroimaging in Stroke (SCANS) Study.
Cerebral small vessel disease (SVD) is a common cause of vascular cognitive impairment. A number of disease features can be assessed on MRI including lacunar infarcts, T2 lesion volume, brain atrophy, and cerebral microbleeds. In addition, diffusion tensor imaging (DTI) is sensitive to disruption of white matter ultrastructure, and recently it has been suggested that additional information on the pattern of damage may be obtained from axial diffusivity, a proposed marker of axonal damage, and radial diffusivity, an indicator of demyelination. We determined the contribution of these whole brain MRI markers to cognitive impairment in SVD. Consecutive patients with lacunar stroke and confluent leukoaraiosis were recruited into the ongoing SCANS study of cognitive impairment in SVD (n = 115), and underwent neuropsychological assessment and multimodal MRI. SVD subjects displayed poor performance on tests of executive function and processing speed. In the SVD group brain volume was lower, white matter hyperintensity volume higher and all diffusion characteristics differed significantly from control subjects (n = 50). On multi-predictor analysis independent predictors of executive function in SVD were lacunar infarct count and diffusivity of normal appearing white matter on DTI. Independent predictors of processing speed were lacunar infarct count and brain atrophy. Radial diffusivity was a stronger DTI predictor than axial diffusivity, suggesting ischaemic demyelination, seen neuropathologically in SVD, may be an important predictor of cognitive impairment in SVD. Our study provides information on the mechanism of cognitive impairment in SVD
In pursuit of giants: I. The evolution of the dust-to-stellar mass ratio in distant dusty galaxies
The dust-to-stellar mass ratio (Mdust/M?) is a crucial, albeit poorly constrained, parameter for improving our understanding of the
complex physical processes involved in the production of dust, metals, and stars in galaxy evolution. In this work, we explore trends
of Mdust/M? with dierent physical parameters and using observations of 300 massive dusty star-forming galaxies detected with
ALMA up to z 5. Additionally, we interpret our findings with dierent models of dusty galaxy formation. We find that Mdust/M?
evolves with redshift, stellar mass, specific star formation rates, and integrated dust size, but that evolution is dierent for mainsequence
galaxies than it is for starburst galaxies. In both galaxy populations, Mdust/M? increases until z 2, followed by a roughly
flat trend towards higher redshifts, suggesting ecient dust growth in the distant universe. We confirm that the inverse relation
between Mdust/M? and M? holds up to z 5 and can be interpreted as an evolutionary transition from early to late starburst phases.
We demonstrate that the Mdust/M? in starbursts reflects the increase in molecular gas fraction with redshift and attains the highest
values for sources with the most compact dusty star formation. State-of-the-art cosmological simulations that include self-consistent
dust growth have the capacity to broadly reproduce the evolution of Mdust/M? in main-sequence galaxies, but underestimating it in
starbursts. The latter is found to be linked to lower gas-phase metallicities and longer dust-growth timescales relative to observations.
The results of phenomenological models based on the main-sequence and starburst dichotomy as well as analytical models that include
recipes for rapid metal enrichment are consistent with our observations. Therefore, our results strongly suggest that high Mdust/M?
is due to rapid dust grain growth in the metal-enriched interstellar medium. This work highlights the multi-fold benefits of using
Mdust/M? as a diagnostic tool for: (1) disentangling main-sequence and starburst galaxies up to z 5; (2) probing the evolutionary
phase of massive objects; and (3) refining the treatment of the dust life cycle in simulations
Location of lacunar infarcts correlates with cognition in a sample of non-disabled subjects with age-related white-matter changes: the LADIS study
Objectives: In cerebral small vessel disease, whitematter hyperintensities (WMH) and lacunes are both related to cognition. Still, their respective contribution in older people remains unclear. The purpose of this study is to assess the topographic distribution of lacunes and determine whether it has an impact on cognitive functions in a sample of non-disabled patients with age-related white-matter changes. Methods: Data were drawn from the baseline evaluation of the LADIS (Leucoaraioisis and Disability study) cohort of non-disabled subjects beyond 65 years of age. The neuropsychological evaluation was based on the Mini Mental Status Examination (MMSE), a modified Alzheimer Diseases Assessment Scale for global cognitive functions, and compound Z scores for memory, executive functions, speed and motor control. WMH were rated according to the Fazekas scale; the number of lacunes was assessed in the following areas: lobar white matter, putamen/ pallidum, thalamus, caudate nucleus, internal/external capsule, infratentorial areas. An analysis of covariance was performed after adjustment for possible confounders. Results: Among 633 subjects, 47% had at least one lacune (31% at least one within basal ganglia). The presence of lacunes in the thalamus was associated with lower scores of MMSE (b=20.61; p=0.043), and worse compound scores for speed and motor control (b=20.25; p=0.006), executive functions (b=20.19; p=0.022) independently of the cognitive impact of WMH. There was also a significant negative association between the presence of lacunes in putamen/ pallidum and the memory compound Z score (b=20.13; p=0.038). By contrast, no significant negative association was found between cognitive parameters and the presence of lacunes in internal capsule, lobar white matter and caudate nucleus. Conclusion: In non-disabled elderly subjects with leucoaraisosis, the location of lacunes within subcortical grey matter is a determinant of cognitive impairment, independently of the extent of WMH
Impaired vasoreactivity in mildly disabled CADASIL patients
Background and purpose CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is a rare genetic disease caused by NOTCH3 gene mutations. A dysfunction in vasoreactivity has been proposed as an early event in the pathogenesis of the disease. The aim of this study was to verify whether endothelium dependent and/or independent function is altered in CADASIL patients with respect to controls. Methods Vasoreactivity was studied by a non-invasive pletismographic method in 49 mildly disabled CADASIL patients (30e65 years, 58% male, Rankin scale #2) and 25 controls. Endothelium dependent vasodilatation was assessed by reactive hyperaemia (flow mediated dilationeperipheral arterial tone (FMD-PAT)) and endothelium independent vasoreactivity by glyceryl trinitrate (GTN) administration (GTN-PAT). Results Patients and controls showed comparable age, gender and cardiovascular risk factor distribution. GTN-PAT values were significantly lower in CADASIL patients (1.54 (1.01 to 2.25)) than in controls (1.89 (1.61 to 2.59); p?0.041). FMD-PAT scores did not differ between patients and controls (1.88 (1.57 to 2.43) vs 2.08 (1.81 to 2.58); p?0.126) but 17 CADASIL patients (35%) had FMDPAT scores below the fifth percentile of controls. FMD-PAT and GTN-PAT values correlated both in controls (r?0.648, p<0.001) and CADASIL patients (r?0.563, p<0.001). By multivariable logistic regression for clinical and laboratory variables, only GTN-PAT (OR 0.39, 95% CI 0.15 to 0.97; p?0.044) was independently associated with FMD-PAT below the fifth percentile in CADASIL patients. Conclusions The impaired vasoreactivity observed in CADASIL patients highlights the fact that both endothelial and smooth muscle functional alterations may already be present in mildly disabled subjects. The improvement in vascular function could be a new target for pharmacological trials in CADASIL patients
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