The study of the thermal behavior of a new semicrystalline polyimide

Thermal properties of a new semicrystalline polyimide synthesized from 3,3',4,4' benzophenone tetracarboxylic dianhydride (BTDA) and 2,2 dimethyl 1,2-(4 aminophenoxy) propane (DMDA) were studied. Heat capacities in the solid and liquid states of BTDA-DMDA were measured. The heat capacity increase at the glass transition temperature (T sub g = 230 C) is 145 J/(C mol) for amorphous BTDA-DMDA. The equilibrium heat of fusion of the BTDA-DMDA crystals was obtained using wide angle X ray diffraction and differential scanning calorimetry measurements, and it is 75.8 kJ/mol. Based on the information of crystallinity and the heat capacity increase at T sub g, a rigid amorphous fraction is identified in semicrystalline BTDA-DMDA samples. The rigid amorphous fraction represents an interfacial region between the crystalline and amorphous states. In particular, this fraction increases with the crystallinity of the sample which should be associated with crystal sizes, and therefore, with crystal morphology. It was also found that this polymer has a high temperature crystal phase upon annealing above its original melting temperature. The thermal degradation activation energies are determined to be 154 and 150 kJ/mol in nitrogen and air, respectively

The Modern Diagnostic Approach to Community-Acquired Pneumonia in Adults

Respiratory tract infections, the majority of which are community acquired, are among the leading causes of death worldwide and a leading indication for hospital admission. The burden of disease demonstrates a "U"-shaped distribution, primarily affecting young children as the immune system matures, and older adults as the process of immunosenescence and accumulation of comorbidities leads to increased susceptibility to infection. Diagnosis of community-acquired pneumonia (CAP) is traditionally based on demonstration of a new infiltrate on a chest radiograph in a patient presenting with an acute respiratory illness or sepsis. Advances in diagnosis have been slow, and although there are increasing data on the value of computed tomography or lung ultrasound as more sensitive diagnostic methodologies, they are not widely used as initial diagnostic tests. There are a wide range of differential diagnoses and pneumonia "mimics" which should be considered in patients presenting with CAP. Once the diagnosis of CAP has been made, identifying the causative microorganism is the next stage in the diagnostic process. Traditional culture-based approaches are relatively insensitive and achieve a positive diagnosis in only 30 to 70% of cases, even when rigorously applied. Urinary antigen tests, polymerase chain reaction assays, and even next-generation sequencing technologies have become available and are increasing the rates of positive diagnosis. In an era of increasing antimicrobial resistance, the accurate diagnosis of CAP and determining the causative pathogen are ever more important. Getting these both right is key in reducing both morbidity and mortality from CAP, and appropriate antimicrobial stewardship which is now an international healthcare priority.</p

Reason and eros

This study is not intended as a work of research into any existing body of philosopny. It is, rather, an independent inquiry into the origins and the objective of philosophical activity. In this it assumes the somewhat enigmatic role of a philosophy of philosophy

A Survey of Quality of Service in Mobile Computing Environments

Accepted versio

EFFICIENT ANALYTIC COMPUTATION OF HIGHER-ORDER QCD AMPLITUDES

We review techniques simplifying the analytic calculation of one-loop QCD amplitudes with many external legs, for use in next-to-leading-order corrections to multi-jet processes. Particularly useful are the constraints imposed by perturbative unitarity, collinear singularities and a supersymmetry-inspired organization of helicity amplitudes. Certain sequences of one-loop helicity amplitudes with an arbitrary number of external gluons have been obtained using these constraints.Comment: Talk given at Beyond the Standard Model IV, December 13-18 1994, Lake Tahoe, CA. Latex, 4 pages, no figures

Caring for continence in stroke care settings: a qualitative study of patients’ and staff perspectives on the implementation of a new continence care intervention

Objectives: Investigate the perspectives of patients and nursing staff on the implementation of an augmented continence care intervention after stroke. Design: Qualitative data were elicited during semi-structured interviews with patients (n = 15) and staff (14 nurses; nine nursing assistants) and analysed using thematic analysis. Setting: Mixed acute and rehabilitation stroke ward. Participants: Stroke patients and nursing staff that experienced an enhanced continence care intervention. Results: Four themes emerged from patients’ interviews describing: (a) challenges communicating about continence (initiating conversations and information exchange); (b) mixed perceptions of continence care; (c) ambiguity of focus between mobility and continence issues; and (d) inconsistent involvement in continence care decision making. Patients’ perceptions reflected the severity of their urinary incontinence. Staff described changes in: (i) knowledge as a consequence of specialist training; (ii) continence interventions (including the development of nurse-led initiatives to reduce the incidence of unnecessary catheterisation among patients admitted to their ward); (iii) changes in attitude towards continence from containment approaches to continence rehabilitation; and (iv) the challenges of providing continence care within a stroke care context including limitations in access to continence care equipment or products, and institutional attitudes towards continence. Conclusion: Patients (particularly those with severe urinary incontinence) described challenges communicating about and involvement in continence care decisions. In contrast, nurses described improved continence knowledge, attitudes and confidence alongside a shift from containment to rehabilitative approaches. Contextual components including care from point of hospital admission, equipment accessibility and interdisciplinary approaches were perceived as important factors to enhancing continence care

Management of chronic airway diseases:What can we learn from real-life data?

Chronic obstructive pulmonary disease (COPD), alpha-1 antitrypsin deficiency (AATD) and non-cystic fibrosis bronchiectasis (hereafter referred to as bronchiectasis) are distinct but related airway diseases: COPD is characterised by persistent and usually progressive airflow limitation associated with an enhanced chronic inflammatory response in the airways and lung to noxious particles or gases (1). COPD is a clinical and physiological diagnosis. AATD is a genetic disorder that causes defective production of alpha-1-antitrypsin (AAT), leading to decreased AAT activity in the blood and lungs and deposition of excessive abnormal AAT protein in liver cells (2). AATD is a laboratory diagnosis. Bronchiectasis is characterised by the presence of airway dilatation and wall thickening on imaging (e.g. computed tomography [CT]), with persistent or recurrent bronchial infection (3). Bronchiectasis is a pathological or radiological diagnosis. Despite differences in the pathobiology of these conditions, they share many of the same clinical features and many of the same challenges. A definitive diagnosis is often complicated by symptom non-specificity as illustrated in a case study