1,527 research outputs found

    The calculation of the wave drag of a family of low-drag axisymmetric nose shapes of fineness ratio 4.5 at zero incidence at supersonic speeds

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    The pressure drag coefficients of a particular family of convex logarithmic projectile nose shapes in which the nose angle is an important parameter have been calculated over a range of supersonic Mach numbers using a rapid approximate method due to Zienkiewicz.5 The optimum nose angle for minimum wave drag of these profiles for each Mach number has been obtained. It is shown that above N = 1.5„ approximately, the optimum shape is similar to the hypersonic optimum profile and has the sane or- less wave drag than this profile. However for values of M/F, where P is the fineness ratio, below 0.5, both the hypersonic and the logarithmic optimum profiles have a higher drag than the so-called cubic profile (Ref, 9)

    A short history of anti-rheumatic therapy. II. Aspirin

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    The discovery of aspirin, an antipyretic, anti-inflammatory and analgesic drug, undoubtedly represents a milestone in the history of medical therapy. Since ancient times the derivatives of willow (Salix alba) were used to treat a variety of fevers and pain syndromes, although the first report dates back to 1763 when the English Reverend Edward Stone described the effect of an extract of the bark willow in treating malaria. In the XIX century many apothecaries and chemists, including the Italian Raffaele Piria and Cesare Bertagnini, developed the biological processes of extraction and chemical synthesis of salicylates, and then analyzed their therapeutic properties and pharmacokinetic and pharmacodynamic characteristics. In 1899 the Bayer Company, where Felix Hoffmann, Heinrich Dreser and Arthur Eichengrun worked, recorded acetyl-salicylic acid under the name "Aspirin". In the XX century, besides the definition of the correct applications of aspirin in the anti-rheumatic therapy being defined, Lawrence L. Crawen identified the property of this drug as an anti-platelet agent, thus opening the way for more widespread uses in cardiovascular diseases

    [Filippo Civinini (1805-1844) and the discovery of plantar neuroma].

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    Pathological abnormality (neuroma) related to the painful foot condition commonly called "Morton's metatarsalgia" was first observed in 1835 by Filippo Civinini (1805-1844) of Pistoia, in course of a cadaverous dissection, and clearly described in the anatomic letter entitled "Su un nervoso gangliare rigonfiamento alla pianta del piede" ("On the neural gangliar swelling of the foot sole"). In this study a brief review on the history of Morton's metatarsalgia is carried out, and the importance of Civinini in the discovery of the neuroma of the III intermetatarsal web is underlined

    A short history of anti-rheumatic therapy - VI. Rheumatoid arthritis drugs

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    The treatment of rheumatoid arthritis traditionally includes symptomatic drugs, showing a prompt action on pain and infl ammation, but without any infl uence on disease progression, and other drugs that could modify the disease course and occasionally induce clinical remission (DMARDs or disease modifying anti-rheumatic drugs). This review describes the historical steps that led to the use of the main DMARDs in rheumatoid arthritis, such as gold salts, sulphasalazine, chloroquine and hydroxychloroquine, D-penicillamine, and other immunoactive drugs, including methotrexate, azathioprine, cyclosporin and lefl unomide. The historical evolution of use of these drugs is then discussed, including the strategy of progressive ("therapeutic pyramid") or of more aggressive treatment, through the simultaneous use of two or more DMARDs ("combination therapy")

    Wars in the history of rheumatology

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    Some important discoveries in the history of rheumatology happened during war periods. It is well known that arthritis associated with conjunctivitis and urethritis, following dysenteric episodes, has been described during the First World War from the German Hans Reiter and, nearly contemporarily, from the French Noel Fiessinger and Edgar Leroy. Less known is instead the fact that the first cases of sympathetic algoneurodystrophy have been reported by the American Silas Weir Mitchell in soldiers wounded by fire-arms, during the Civil War of Secession. Other war episodes have been crucial for the development of some drugs now abundantly applied to the care of rheumatic diseases. The discovery of therapeutic effects of immunosuppressive agents, in fact, happened as an indirect consequence of the use of poison gas, already during the First World War (mustard gas), but above all after an episode in the port of Bari in 1943, where an American cargo boat was sunk. It had been loaded with a quantity of cylinders containing a nitrogenous mustard, whose diffusion in the environment provoked more than 80 deaths owing to bone marrow aplasia.Moreover, the history of the cortisone shows a strict link to the Second World War, when Germany imported large quantities of bovine adrenal glands from Argentina, with the purpose of producing some gland extracts for the Luftwasse aviators, in order to increase their performance ability

    A short history of anti-rheumatic therapy. I. An introduction on traditional and drug treatments

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    The origins of anti-rheumatic therapy are very old and mainly related to the use of traditional, sometimes extravagant, treatments, as a part of folk medicine. Spa therapy has long been used for the treatment of rheumatic diseases, as well as, in later times, physical treatments, including electrotherapy. Drug treatment has developed beginning from substances of vegetable origin, such as willow and colchicum extracts. Then it has been spread out through the chemical synthesis of compounds with specific action and therefore more effective, owing to the great development of pharmaceutical industry

    The application of a Bayesian approach to assess the seismic vulnerability of historical centers

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    The seismic vulnerability of historical centers at a territorial scale cannot be assessed performing detailed analysis which are usually adopted at the single building scale. In fact, a traditional complete survey would be extremely time-consuming and not sustainable for this purpose. The approach described in this paper is based on the idea that it is possible to infer quantities which cannot be directly detected from buildings outside inspection starting from parameters that can be measured. In order to achieve this purpose, a Bayesian approach is applied, updating initial hypotheses when new data become available. In this context, the procedure herein proposed aims at applying a probabilistic approach instead of a deterministic one to define facades inter-storey height starting from buildings height knowledge. In order to validate the method, for out of plane local mechanisms of collapse (walls overturning), horizontal loads multiplier \uf0610 values are calculated and compared to results obtained by using data collected on-site

    Should we stop saying "epileptic"? A comparison of the effect of the terms "epileptic" and "person with epilepsy"

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    AbstractObjectiveThe advantages and disadvantages of using “epileptic” as a noun to describe someone with epilepsy have long been debated. Recent high-profile recommendations have stated that the term should not be used, including in English, as it perpetuates stigma. This decision was largely informed by a Brazilian Global Campaign Against Epilepsy study that reported experimental evidence indicating that, with students, the label evokes more negative attitudes than “person with epilepsy”. The generalizability of this effect to different countries/cultures, and thus the justification for the recommendations, has never been tested.MethodsWe replicated the Brazilian study in the UK, in English, while also addressing methodological limitations. It was powered to detect the effects reported by the Brazilian study, with 234 students completing a survey regarding epilepsy attitudes. Half were randomized to Group 1 and half to Group 2. In Group 1, patients were referred to as “people/person with epilepsy” within the attitudinal measures, while in Group 2 they were referred to as “epileptic/s”. Measures included translations of the questions used in the Brazilian study and the Attitudes and Beliefs about Living with Epilepsy scale. Participants' epilepsy familiarity and knowledge were also assessed.ResultsThe two groups were comparable in characteristics. A comparison of their responses to the attitude measures revealed no statistically significant or meaningful differences.ConclusionsIn this English replication, the word “epileptic” did not provoke more negative attitudes. This suggests that the effect reported by the Brazilian study might be culturally dependent. Methodological limitations to that study might also be relevant. Our results have implications for the global debate about how negative attitudes towards epilepsy might be addressed. Simply not saying “epileptic” may not promote the positive attitudes towards epilepsy that had been expected. To know how to best refer to those with epilepsy, evidence on the preferences of those actually living with epilepsy is needed

    Flatness optimization of micro-injection moulded parts: The case of a PMMA microfluidic component

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    Micro-injection moulding (µ-IM) has attracted a lot of interest because of its potential for the production of low-cost, miniaturized parts in high-volume. Applications of this technology are, amongst others, microfluidic components for lab-on-a-chip devices and micro-optical components. In both cases, the control of the part flatness is a key aspect to maintaining the component's functionality. The objective of this work is to determine the factors affecting the flatness of a polymer part manufactured by µ-IM and to control the manufacturing process with the aim of minimizing the in-process part deformation. As a case study, a PMMA microfluidic substrate with overall dimensions of 10 mm diameter and 1 mm thickness was investigated by designing a µ-IM experiment having flatness as the experimental response. The part flatness was measured using a micro-coordinate measuring machine. Finite elements analysis was also carried out to study the optimal ejection pin configuration. The results of this work show that the control of the µ-IM process conditions can improve the flatness of the polymer part up to about 15 µm. Part flatness as low as 4 µm can be achieved by modifying the design of the ejection system according to suggested guideline

    The main stages in the history of systemic lupus erythematosus

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    Systemic lupus erythematosus can be considered the most characteristic and important among the connective tissue diseases. In this short review the main stages of its history are sketched, from the introduction of the term "lupus", traditionally attributed to Roger Frugardi, in 1230 (but in fact already documented in the 10th century) to the actual knowledge of its clinical and laboratory aspects. Initially considered exclusively of dermatological interest, the first to describe a systemic form with visceral involvement were Moriz Kohn Kaposi and William Osler. Significant contribution was also given by serological diagnosis, and in particular, by the identification of specific markers of disease, such as anti-native DNA and anti-Sm antibodies, allowing early diagnosis and the establishment of an adequate therapy
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