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Progressive systemic sclerosis (PSS), a disease still of unknown origin, is a generalized autoimmune disorder characterized by immunological abnormalities, microvascular dysfunction, and tissue fibrosis. The mechanism leading to selective microvascular injury in PSS is not completely known, however it is now clear that neuropeptides, vascular endothelium, and disturbances in the regulation of fibroblast function are the three major contributors to the increased fibrosis of skin and internal organs. Thus, endothelial cell and fibroblast dysfunction may be linked through the paracrine activity of soluble endothelial cell products: the cytokine cascade (IL-1, TGF-beta-1, PDGF, TNF, etc.). In systemic sclerosis, the exaggerated generalized vasospastic tendency is clinically represented by Raynaud's phenomenon as shown by an early digital arterial closure after cold stimulation, and by an inadequate vasodilatory response to heat. In this review we summarize recently established data that center around the role of adhesion molecules, immune reactions, and aberrant fibroblast biology and metabolism in effecting vascular and connective tissue alterations in this disease. Only a better knowledge of the pathophysiological process involved in scleroderma might lead to the development of new therapeutic approaches.  相似文献   
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Personalcasting: Tailored Broadcast News   总被引:1,自引:0,他引:1  
Broadcast news sources and newspapers provide society with the vast majority of real-time information. Unfortunately, cost efficiencies and real-time pressures demand that producers, editors, and writers select and organize content for stereotypical audiences. In this article we illustrate how content understanding, user modeling, and tailored presentation generation promise personalcasts on demand. Specifically, we report on the design and implementation of a personalized version of a broadcast news understanding system, MITRE’s Broadcast News Navigator (BNN), that tracks and infers user content interests and media preferences. We report on the incorporation of Local Context Analysis to both expand the user’s original query to the most related terms in the corpus, as well as to allow the user to provide interactive feedback to enhance the relevance of selected newsstories. We describe an empirical study of the search for stories on ten topics from a video corpus. By personalizing both the selection of stories and the form in which they are delivered, we provide users with tailored broadcast news. This individual news personalization provides more fine-grained content tailoring than current personalized television program level recommenders and does not rely on externally provided program metadata.  相似文献   
4.
Ionic liquids as coated catalysts or additives tremendously alter the selectivity pattern of the heterogeneous solid catalyst in the selective hydrogenation of limonene. The conventional monometallic ruthenium over alumina catalyst combined with an ionic liquid enables the one-pot synthesis of the intermediate p-menthene through limonene hydrogenation in supercritical carbon dioxide. Among eight screened imidazolium ILs, [C10mim]NTf2 was employed as additive, or as the coating agent of ruthenium catalyst in the reaction under supercritical conditions.The coating of the heterogeneous catalyst allows the selective production of p-menthene and increases the conversion level of limonene (>99%) compared to the conversion of limonene in the reaction carried out in the presence of an ionic liquid as an additive. Results of the catalyst recycling indicate that there is no depletion of catalyst reactivity even after four successive cycles of operation under the studied reaction conditions. Further hydrogenation of p-menthene is strongly inhibited by employing an ionic liquid. The solubility of limonene or p-menthene in an ionic liquid governs the selective hydrogenation of limonene towards p-menthene.  相似文献   
5.
The European Radiation Dosimetry Group, EURADOS, established a working group consisting of experts whose aim is to assist in the process of harmonisation of individual monitoring as part of the protection of occupationally exposed workers. A catalogue of facilities and internal dosimetric techniques related to individual monitoring in Europe has been completed as a result of this EURADOS study. A questionnaire was sent in 2002 to services requesting information on various topics including type of exposures, techniques used for direct and indirect measurements including calibration and sensitivity data and the methods employed for the assessment of internal doses. Information relating to Quality Control procedures for direct and indirect measurements, Quality Assurance Programmes in the facilities and legal requirements for "approved dosimetric services" were also considered. A total of 71 completed questionnaires were returned by internal dosimetry facilities in 26 countries. This results in an overview of the actual status of the processes used in internal exposure estimation in Europe. In many ways harmonisation is a reality in internal dose assessments, especially when taking into account the measurements of the activity retained or excreted from the body. However, a future study detailing the estimation of minimum detectable activity in the laboratories is highly recommended. Points to focus on in future harmonisation activities are as follows: the process of calculation of doses from measured activity, establishment of guidelines, similar dosimetric tools and application of the same ICRP recommendations. This would lead to a better and more harmonised approach to the estimation of internal exposures in all European facilities.  相似文献   
6.
The tropical forest cover has varied greatly over the last few decades. The rapid advance of agricultural crops and illegal clearings in natural areas has resulted in the conversion of the majority of the world’s forest into desolated patches. Although rates of deforestation have decreased compared to previous years, forest loss still remains a crucial concern. Latest studies conducted on a global scale identified the Latin American continent as one of the regions exhibiting the highest rates of deforestation in the world. The dynamics of forests over the past 40 years has attracted numerous remote-sensing-based studies to monitor forest loss, analyse patterns, and understand the drivers of land conversion. This review article provides a comprehensive overview of the remote-sensing-based studies of tropical forest dynamics in Latin America. Following an introduction with respect to global forest mapping products, a general outline of tropical forest ecoregions and drivers of deforestation in Latin America is provided. Subsequently, a review and categorization of the existing studies is presented, where focus is laid on selected sensors and data analysis methodologies apply. Furthermore, a case study for the whole of Paraguay is presented; Paraguay is a region which contains highly diverse ecosystems that have been ravaged as a result of deforestation over the past 40 years. The main results, challenges, and future needs are discussed.  相似文献   
7.
This paper is a compilation of quantitative data available on volatile compounds reported so far in 18 food items including some legume, cereals, grapes and cheeses as well as crab, lobster, cocoa and chocolate. No publications reporting quantitative data were found for five of these 18 food products, i.e. sultana grape, broad beans, cassava, oat and rye. About 440 volatile compounds have been assayed globally in the other 13 food products and more than 50% of them were found in grape or in grape juice. Levels of these volatile compounds in the selected foods were generally in the ppb range and less often in the low ppm range. Very high levels were found for some carboxylic acids in cheeses and cocoa and for some alcohols and acids as well as for ethyl acetate in grape juice.  相似文献   
8.
Thromboembolic disease (TE) is an important cause of in-hospital morbidity and mortality. The relationship between cancer and abnormalities of blood coagulation has been recognized for well over a century. Deep venous thrombosis (DVT) of the lower extremities is the most common cause of thromboembolic disease, but pulmonary embolism, upper extremity vein thrombosis, disseminated intravascular coagulation, and other, more unusual, clinical events, may occur. Unexplained TE may serve as a marker for the presence of a hidden tumor. The frequency of pulmonary embolism (PE) among patients with a malignant neoplasm at necropsy is highly increased in the elderly patients. Among subjects with a malignant neoplasm, patients with pancreatic and gastric cancer (mucin-secreting adenocarcinomas), cancer of the large bowel and women with ovarian cancer had the highest frequency of PE. Old age, female sex, gastrointestinal and ovarian cancers must be considered as a significant risk factor for PE. The potentially responsible mechanisms for the thrombotic events, clinical manifestations, diagnostic implications and aspects of treatment of TE in malignant disease are discussed.  相似文献   
9.
It has been demonstrated that mainly amorphous new formations grow during the hydration and strengthening of dump ferrous slag from different metallurgical processes, with or without activators (additions of 2–3% of Portland cement) and mixed with natural soils. Their high rates of strength, and water and frost resistance render of these new materials appropriate for the construction of roads and airfield runways, levee cores, industrial and municipal dumps, building foundations, etc. In addition to their economic advantages, these materials are extremely easy to use and do not create new residues.
Résumé Il a été démontré que la plupart des nouvelles formations amorphes croissent durant l'hydratation et le renforcement de déchets de scories ferreuses issus de différents processus métalurgiques, avec ou sans activateurs (addition de 2–3% de ciment Portland) et mélangés avec des sols naturels. Leur haute résistance et leur capacité à accepter l'eau et le gel rendent ces nouveaux matériaux appropriés pour la construction de routes et de pistes d'aéroports, de basements de digues, de décharges industrielles et municipales, de fondations d'immeubles, etc. En plus de leurs avantages économiques, ces matériaux sont très facilement utilisables et ne produisent pas de résidus supplémentaires.
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10.
A case of polycythaemia vera, in which a crural ulcer appeared numerous years after the onset of the disease, is reported. The absence of important angioneurological lesions and the signs at cutaneous lesion level of capillary dilatation, suggest that crural ulcer is a complication of polycythaemia. Aetiopathogenetic aspects are also discussed.  相似文献   
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