RESUMO
Nanocellulose is a bio-based material that holds significant potential in the field of water purification. Of particular interest is their potential use as a key sorbent material for the removal of metal ions from solution. However, the structure of metal ions adsorbed onto cellulose surfaces is not well understood. The focus of this work is to determine quantitatively the three-dimensional distribution of metal ions of different valencies surrounding negatively charged carboxylate functionalized cellulose nanocrystals (CNCs) using anomalous small-angle X-ray scattering (ASAXS). These distributions can affect the water and ionic permeability in these materials. The data show that increasing the carboxylate density on the surface of the CNCs from 740 to 1100 mmol/kg changed the nature of the structure of the adsorbed ions from a monolayer into a multilayer structure. The monolayer was modeled as a Stern layer around the CNC nanoparticles, whereas the multilayer structure was modeled as a diffuse layer on top of the Stern layer around the nanoparticles. Within the Stern layer, the maximum ion density increases from 1680 to 4350 mmol of Rb+/(kg of CNC) with the increase in the carboxylate density on the surface of the nanoparticles. Additionally, the data show that CNCs can leverage multiple mechanisms, such as electrostatic attraction and the chaotropic effect, to adsorb ions of different valencies. By understanding the spatial organization of the adsorbed metal ions, the design of cellulose-based sorbents can be further optimized to improve the uptake capacity and selectivity in separation applications.
RESUMO
ObjectivesTo estimate the absolute risk of cerebral venous thrombosis (CVT) and portal vein thrombosis (PVT) in the two weeks following a diagnosis of COVID-19, and to assess the relative risks (RR) compared to influenza or the administration of an mRNA vaccine against COVID-19. DesignRetrospective cohort study based on an electronic health records network SettingLinked records between primary and secondary care centres within 59 healthcare organisations, primarily in the USA ParticipantsAll patients with a confirmed diagnosis of COVID-19 between January 20, 2020 and March 25, 2021 were included (N=537,913, mean [SD] age: 46.2 [21.4] years; 54.9% females). Cohorts (matched for age, sex, and race) of participants diagnosed with influenza (N=392,424) or receiving the BNT162b2 or mRNA-1273 vaccine (N=366,869) were used for comparison. Main outcome measuresDiagnosis of CVT (ICD-10 code I67.6) or PVT (ICD-10 code I81) within 2 weeks after a diagnosis of COVID-19. ResultsThe incidence of CVT after COVID-19 diagnosis was 42.8 per million people (95% CI 28.5-64.2) including 35.3 per million (95% CI 22.6-55.2) first diagnoses. This was significantly higher than the CVT incidence in a matched cohort of patients with influenza (RR=3.83, 95% CI 1.56-9.41, P<0.001) and people who received an mRNA vaccine (RR=6.67, 95% CI 1.98-22.43, P<0.001). The incidence of PVT after COVID-19 diagnosis was 392.3 per million people (95% CI 342.8-448.9) including 175.0 per million (95% CI 143.0-214.1) first diagnoses. This was significantly higher than the PVT incidence in a matched cohort of patients with influenza (RR=1.39, 95% CI 1.06-1.83, P=0.02) and people who received an mRNA vaccine (RR=7.40, 95% CI 4.87-11.24, P<0.001). Mortality after CVT and PVT was 17.4% and 19.9% respectively. ConclusionsThe incidence of CVT and PVT is significantly increased after COVID-19. The data highlight the risk of serious thrombotic events in COVID-19 and can help contextualize the risks and benefits of vaccination in this regard. What is known- A systematic review of cohort studies suggested an incidence of CVT among hospitalised patients with COVID-19 to be about 800 per million patients. There was evidence of selection, ascertainment, and reporting bias in all included studies. - The incidence of CVT and PVT among both hospitalised and non-hospitalised patients with COVID-19 is unknown. - It is unknown if COVID-19 increases the risk of CVT and PVT. What this study addsOur study estimates that the absolute risk of CVT and PVT are respectively 42.8 and 392.3 per million patients (both hospitalised and non-hospitalised) in the 2 weeks after a diagnosis of COVID-19. COVID-19 increases the risk of CVT and PVT compared to patients diagnosed with influenza, and to people who have received a COVID-19 mRNA vaccine.
RESUMO
BackgroundThe medium-term effects of Coronavirus disease (COVID-19) on multiple organ health, exercise capacity, cognition, quality of life and mental health are poorly understood. MethodsFifty-eight COVID-19 patients post-hospital discharge and 30 comorbidity-matched controls were prospectively enrolled for multiorgan (brain, lungs, heart, liver and kidneys) magnetic resonance imaging (MRI), spirometry, six-minute walk test, cardiopulmonary exercise test (CPET), quality of life, cognitive and mental health assessments. FindingsAt 2-3 months from disease-onset, 64% of patients experienced persistent breathlessness and 55% complained of significant fatigue. On MRI, tissue signal abnormalities were seen in the lungs (60%), heart (26%), liver (10%) and kidneys (29%) of patients. COVID-19 patients also exhibited tissue changes in the thalamus, posterior thalamic radiations and sagittal stratum on brain MRI and demonstrated impaired cognitive performance, specifically in the executive and visuospatial domain relative to controls. Exercise tolerance (maximal oxygen consumption and ventilatory efficiency on CPET) and six-minute walk distance (405{+/-}118m vs 517{+/-}106m in controls, p<0.0001) were significantly reduced in patients. The extent of extra-pulmonary MRI abnormalities and exercise tolerance correlated with serum markers of ongoing inflammation and severity of acute illness. Patients were more likely to report symptoms of moderate to severe anxiety (35% versus 10%, p=0.012) and depression (39% versus 17%, p=0.036) and a significant impairment in all domains of quality of life compared to controls. InterpretationA significant proportion of COVID-19 patients discharged from hospital experience ongoing symptoms of breathlessness, fatigue, anxiety, depression and exercise limitation at 2-3 months from disease-onset. Persistent lung and extra-pulmonary organ MRI findings are common. In COVID-19 survivors, chronic inflammation may underlie multiorgan abnormalities and contribute to impaired quality of life. FundingNIHR Oxford and Oxford Health Biomedical Research Centres, British Heart Foundation Centre for Research Excellence, UKRI, Wellcome Trust, British Heart Foundation.
RESUMO
Schizophrenia is a severe mental disorder striking mainly young adults and leading to life-long disability in a substantial portion of the sufferers. On the other hand, substantial knowledge about its etiology and pathogenesis is still lacking. Therefore the European Science Foundation (ESF) sponsored a meeting of a panel of European experts on schizophrenia research to discuss the state of art and future perspectives of key topics in this area. The fields covered genetics, epidemiology, animal models, molecular neuropathology and imaging. This was a first step to establish a network of European groups dedicated to Schizophrenia research. The coming calls of the frame work program will be used to strengthen this network in order to achieve substantial progress in understanding and treating this devastating illness.
