Carbon nanotube (CNT) reinforced (0.05–0.5% by wt) polycaprolactone (PCL)‐based composites were prepared by compression molding. Addition of 0.2% CNT caused a 131% improvement of tensile strength (TS) of PCL films. The tensile modulus (TM) and elongation at break (Eb) of PCL were also significantly improved with the addition of CNT. The water vapor permeability of PCL was 1.51 g·mm/m2·day but 0.2% CNT containing PCL films showed 1.08 g·mm/m2·day. Similarly, the oxygen transmission rate (OTR) of PCL films was found to decrease with the addition of CNT. But, carbon dioxide transmission rate (CO2TR) of PCL film was improved due to incorporation of CNT. Effect of gamma radiation on PCL films and CNT reinforced PCL‐based composites were also studied. The TS of the irradiated (10 kGy) PCL films gained to 75% higher than control sample. The TS of the 0.2% CNT reinforced composite film was reached to 41 MPa at 15 kGy dose. The barrier properties of non‐irradiated and irradiated (10 kGy) PCL films and composites (0.2% CNT reinforced) were also measured. Both PCL films and composites showed lower values of WVP upon irradiation and indicated better water vapor barrier. The OTR and CO2TR of the irradiated (10 kGy) PCL films and composites were decreased compared to their counterparts. Surface and interface morphologies of the composites were studied by scanning electron microscopy. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
The anti-neutrophil cytoplasmic antibody (ANCA)associated vasculitides (AAVs) are diseases characterized by inflammation of blood vessels, endothelial injury and tissue damage. The three types of small-vessel vasculitis, namely granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic GPA (EGPA; previously known as Churg-Strauss syndrome), feature a loss of tolerance to neutrophil primary granule proteins, most often leukocyte proteinase 3 (PR3; also known as myeloblastin) or myeloperoxidase (MPO) (Table 1). The vessels involved in AAV are typically capillaries, arterioles and venules but small arteries and veins may also be affected. Autoimmunity is documented clinically by serum ANCAs to PR3 (PR3-ANCA) or MPO (MPO-ANCA), which are generally associated with the main syndromic AAV presentations (box 1). AAVs collectively represent one of several types of autoimmune vasculitis (Fig. 1). GPA and MPA can involve small blood vessels in any organ or tissue but commonly affect the upper and lower respiratory tract and the kidneys (box 2). Patients with AAV typically present with severe organ-threatening or life-threatening disease, although less severe presentations also occur. GPA is predominantly associated with PR3-ANCA and its clinical features typically include sinonasal disease, lower respiratory tract involvement with pulmonary haemorrhage and granulomatous inflammation, and glomerulonephritis. MPA is usually associated with MPO-ANCA and clinical features include more severe renal disease and some of the manifestations of GPA but without granulomatous inflammation. EGPA is characterized by asthma, eosinophilia and, in many (but not all) cases, vasculitis. EGPA is less common than GPA or MPA and, in some cases, is associated with ANCAs, mainly MPO-ANCA (Table 1). Although categorized as a form of AAV, EGPA has less overlap with the other AAVs than that between GPA and MPA with regard to its genetic, pathogenetic, and clinical features and its management and is typically considered a separate entity. Improvements in treatment and prognosis for patients with AAV have resulted from the translation of both preclinical and clinical research findings. Here, we provide an updated overview of the clinical and
Background The impact of COVID-19 on physical and mental health and employment after hospitalisation with acute disease is not well understood. The aim of this study was to determine the effects of COVID-19-related hospitalisation on health and employment, to identify factors associated with recovery, and to describe recovery phenotypes. MethodsThe Post-hospitalisation COVID-19 study (PHOSP-COVID) is a multicentre, long-term follow-up study of adults (aged ≥18 years) discharged from hospital in the UK with a clinical diagnosis of COVID-19, involving an assessment between 2 and 7 months after discharge, including detailed recording of symptoms, and physiological and biochemical testing. Multivariable logistic regression was done for the primary outcome of patient-perceived recovery, with age, sex, ethnicity, body-mass index, comorbidities, and severity of acute illness as covariates. A posthoc cluster analysis of outcomes for breathlessness, fatigue, mental health, cognitive impairment, and physical performance was done using the clustering large applications k-medoids approach. The study is registered on the ISRCTN Registry (ISRCTN10980107). Findings We report findings for 1077 patients discharged from hospital between March 5 and Nov 30, 2020, who underwent assessment at a median of 5•9 months (IQR 4•9-6•5) after discharge. Participants had a mean age of 58 years (SD 13); 384 (36%) were female, 710 (69%) were of white ethnicity, 288 (27%) had received mechanical ventilation, and 540 (50%) had at least two comorbidities. At follow-up, only 239 (29%) of 830 participants felt fully recovered, 158 (20%) of 806 had a new disability (assessed by the Washington Group Short Set on Functioning), and 124 (19%) of 641 experienced a health-related change in occupation. Factors associated with not recovering were female sex, middle age (40-59 years), two or more comorbidities, and more severe acute illness. The magnitude of the persistent health burden was substantial but only weakly associated with the severity of acute illness. Four clusters were identified with different severities of mental and physical health impairment (n=767): very severe (131 patients, 17%), severe (159, 21%), moderate along with cognitive impairment (127, 17%), and mild (350, 46%). Of the outcomes used in the cluster analysis, all were closely related except for cognitive impairment. Three (3%) of 113 patients in the very severe cluster, nine (7%) of 129 in the severe cluster, 36 (36%) of 99 in the moderate cluster, and 114 (43%) of 267 in the mild cluster reported feeling fully recovered. Persistently elevated serum C-reactive protein was positively associated with cluster severity.Interpretation We identified factors related to not recovering after hospital admission with COVID-19 at 6 months after discharge (eg, female sex, middle age, two or more comorbidities, and more acute severe illness), and four different recovery phenotypes. The severity of physical and mental health impairments were closely related, whereas cognitive health impairments w...
It is now 25 years since the first European studies on vasculitis--the anti-neutrophil cytoplasmic antibody (ANCA) standardization project. Over that period of time, there have been major developments in the classification of the vasculitides, which has permitted the conduct of high-quality epidemiology studies. Studying the epidemiology of rare diseases such as the ANCA-associated vasculitides (AAV) poses considerable challenges to epidemiologists. The first is the need for a clear definition of a case with good differentiation from similar disorders. The second is case capture. The vasculitides are rare, and therefore, a large population is required to determine the incidence and prevalence, and this poses questions of feasibility. A large population increases the risk of incomplete case detection but permits a reasonable number of cases to be collected in a practicable time frame, whereas a smaller population requires a much longer time frame to collect the necessary cases, which may also not be feasible. Statistical methods of capture-recapture analysis enable estimates to be made of the number of missing cases. The third is case ascertainment. The AAV are virtually always managed in secondary care, and therefore, hospital-based case ascertainment may be appropriate. Fourthly, the rarity of the conditions makes prospective case-control studies investigating risk factors difficult to conduct because the population size required to achieve statistical confidence is in excess of that which is readily available. Thus, much of the data on risk factors are derived from retrospective studies with inherent potential bias.
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