Polydimethylsiloxane (PDMS) elastomers are extensively used for soft lithographic replication of microstructures in microfluidic and micro-engineering applications. Elastomeric microstructures are commonly required to fulfil an explicit mechanical role and accordingly their mechanical properties can critically affect device performance. The mechanical properties of elastomers are known to vary with both curing and operational temperatures. However, even for the elastomer most commonly employed in microfluidic applications, Sylgard 184, only a very limited range of data exists regarding the variation in mechanical properties of bulk PDMS with curing temperature. We report an investigation of the variation in the mechanical properties of bulk Sylgard 184 with curing temperature, over the range 25 °C to 200 °C. PDMS samples for tensile and compressive testing were fabricated according to ASTM standards. Data obtained indicates variation in mechanical properties due to curing temperature for Young's modulus of 1.32–2.97 MPa, ultimate tensile strength of 3.51–7.65 MPa, compressive modulus of 117.8–186.9 MPa and ultimate compressive strength of 28.4–51.7 GPa in a range up to 40% strain and hardness of 44–54 ShA.

Despite the considerable progress in the classification of the idiopathic interstitial pneumonias (IIPs), the lack of an international standard has resulted in variable and confusing diagnostic criteria and terminology. The advent of high-resolution computerized tomography, the narrowed pathologic definition of usual interstitial pneumonia (UIP) and recognition of the prognostic importance of separating UIP from other IIP patterns have profoundly changed the approach to the IIPs. This is an international Consensus Statement defining the clinical manifestations, pathology, and radiologic features of patients with IIP. The major objectives of this statement are to standardize the classification of the idiopathic interstitial pneumonias (IIPs) and to establish a uniform set of definitions and criteria for the diagnosis of IIPs. The targeted specialties are pulmonologists, radiologists, and pathologists. A multidisciplinary core panel was responsible for review of background articles and writing of the document. In addition, this group reviewed the clinical, radiologic, and pathologic aspects of a wide spectrum of cases of diffuse parenchymal interstitial lung diseases to establish a uniform and consistent approach to these diseases and to clarify the terminology, definitions, and descriptions used in routine clinical practice. The final statement was drafted after a series of meetings of the entire committee. The level of evidence for the recommendations made in this statement is largely that of expert opinion developed by consensus. This classification of IIPs includes seven clinico-radiologic-pathologic entities: idiopathic pulmonary fibrosis (IPF), nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, acute interstitial pneumonia, respiratory bronchiolitis-associated interstitial lung disease, desquamative interstitial pneumonia, and lymphoid interstitial pneumonia. The need for dynamic interaction between pathologists, radiologists, and pulmonologists to accurately diagnose these disorders is emphasized. The level of evidence for the recommendations made in this Statement is largely that of expert opinion developed by consensus. This Statement is an integrated clinical, radiologic, and pathologic approach to the classification of the IIPs. Use of this international multidisciplinary classification will provide a standardized nomenclature and diagnostic criteria for IIP. This Statement provides a framework for the future study of these entities. Key Messages * Unclassifiable interstitial pneumonia : Some cases are unclassifiable for a variety of reasons (see text). † This group represents a heterogeneous group with poorly characterized clinical and radiologic features that needs further study. ‡ COP is the preferred term, but it is synonymous with idiopathic bronchiolitis obliterans organizing pneumonia.

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Objective-To investigate the role of occupational and domestic exposure to dust in the aetiology of cryptogenic fibrosing alveolitis.Design-Matched case-control study. Subjects-40 Patients with cryptogenic fibrosing alveolitis and 106 community controls matched for age and sex who responded to a questionnaire.Main outcome measure-Responses to self administered questionnaire asking about lifetime exposure to dust, animals, and smoke at home and at work.Results-The patients with cryptogenic fibrosing alveolitis were more likely to report occupational exposure to metal dust (matched odds ratio (95% confidence interval 2*30 to 52.4), p<0-001) or wood dust (2-94 (0.87 to 9.90), p=0.08), to have worked with cattle (10-89 (1-24 to 96 0), p=0.01), and to have lived in a house heated by a wood fire (12-55 (1-04 to 114), p=0009). A history of smoking and social class based on occupation were not significantly related to disease state.Conclusion-Environmental exposure to dust may be an important factor in the aetiology of cryptogenic fibrosing alveolitis.

Abstractprognosis. Physicians generally considered CFA to be a clinical diagnosis and Background -Mortality due to cryptodid not initiate treatment in up to half of genic fibrosing alveolitis (CFA) is inpatients at presentation. creasing, particularly in the elderly. (Thorax 1997;52:38-44) Optimum management remains uncertain and previous studies of the disease have Keywords: cryptogenic fibrosing alveolitis, presentation, largely been from specialist centres. A treatment, British Thoracic Society.national study was carried out of the presentation and initial management of CFA in the UK.In England and Wales mortality due to cryptoMethods -All respiratory physicians in genic fibrosing alveolitis (CFA, also known as England, Scotland and Wales were invited idiopathic pulmonary fibrosis) doubled beto enter patients with newly diagnosed tween 1979 and 1988 1 and continues to in-CFA over a two year period. CFA was crease in the UK, Australia, and Canada. 2 The diagnosed on histological grounds or acincrease in mortality in the elderly is particularly cording to clinical criteria which included striking and the median age at diagnosis has the absence of a defined connective tissue been most recently reported as being in the disorder or pneumoconiosis. Participating seventh decade. 3 4 This compares with earlier physicians (n=150) completed a quesreports of the disease presenting in the fifth or tionnaire at patient entry and at all subsixth decade. [5][6][7] There are indications that the sequent follow up visits and death.disease is frequently diagnosed on clinical Results -A total of 588 patients (373 men, grounds 3 despite previous recommendations 63%) were studied of whom 441 (75%) were that histological data should be obtained. to initiate treatment was made pre-ticipate in a study designed by the Research dominantly on symptomatic grounds. Two