42 research outputs found
Variable dampers to mitigate structural demand to wind turbines: The role of the monitoring system features for the effectiveness of the control strategy
In the last decade, some researchers and professionals have been engaged in the study of methods and techniques that can build high wind turbines while containing construction costs within the limits of economic convenience. Among the most promising solutions is that of using innovative devices to mitigate the structural demand for the towers. The reduction in the stress demand in the foundation makes the strategy particularly interesting for the repowering of existing plants, where it is convenient not to demolish and rebuild the foundation, but rather to reuse the existing one for the new plant. A semi-active vibration control strategy, based on the adoption of controllable dissipative devices, is presented herein. The proposed technique requires the tower to be equipped with a measurement system suitable for the real time monitoring of structural response. Performing reliable high-frequency measurements of the horizontal displacement of points located at heights of tens of meters is not simple. With the purpose of assessing the efficiency and feasibility of Global Navigation Satellite System (GNSS)-based systems for the control of wind turbine structures, the proposed paper tries to investigate the characteristics and data processing techniques that are able to make the GNSS useful for such applications. Several numerical simulations were carried out with reference to a case-study wind turbine to quantitatively assess how the performance of the control system changes as the features of the monitoring system worsen, and finally to draw conclusions and suggestions for the minimum performance that monitoring devices must have for an effective reduction in structural demand
A conical self-expanding metallic stent for the management of critical complex tracheobronchial malignant stenosis
Tracheobronchial malignant stenosis is a life-threatening and challenging condition. In inoperable patients, a stent is the mainstay treatment to ensure ventilation. Here, we report the use of a fully covered standard conical self-expandable metallic stent as an emergency treatment for complex tracheobronchial malignant stenosis. CASE REPOR
Genetically modified animals as models of pulmonary disease
Improvements in biological research and the development of new techniques for human health protection require animal experimentation of various species. In particular, animal models are always necessary to test new therapies for the treatment of various human diseases. The latest advances in molecular biology involving genetic modification are aimed at developing new animal models of human diseases that are not present in spontaneous murine broods or obtainable with other experimental manipulations. Transgenic techniques and, in particular, the possibility to directly modify specific genetic information in the experimental animal have led to the acquisition of important knowledge on the physiologic functions of many proteins and their function in the course of various diseases. The advent of new transgenic animals is opening up new and interesting frontiers, full of hope and opportunity, for the research into pulmonary diseases. New advances in cystic fibrosis, emphysema, and pulmonary fibrosis have been made through the study of a large number of proteins implicated in the complex of acute and chronic inflammatory processes of lung parenchyma, which are responsible for permanent changes in organ structure and function. Recent studies carried out on murine inbred strains have yielded significant new data on the multifactor origin of pulmonary disease, because of their correlation with the major histocompatibility complex (H2 in mice) or through the different genetic map of the strains. Today it is possible to outweigh or potentiate the function and expression of some genes, obtaining a deficit or abundance, respectively, of specific proteins. These techniques have permitted and will continue to permit the development of new models of human disease, leading to further therapeutic advances as a consequence
Molecular characterization of a Tax-2C protein variant identified in Brazilian subjects infected by HTLV-2C
Although the etiologic difference in pathogenic properties of HTLV-1 and HTLV-2 still remains unclear, it has been suggested that it could be attributed to the differential structure and activities of their transactivating Tax proteins. Tax-1 and Tax-2, although having 85% amino acid (aa) similarity, present phenotypic differences consistent with a more robust transformation capacity of Tax-1. Interestingly, the HTLV-2C Brazilian variant present in Amerindians and in IDU from urban areas is genotypically close to HTLV-2A but Tax-2C possesses an additional 25aa in the C-terminal region similar to that of Tax-2B. We have already demonstrated that Tax-1 and Tax-2B have several common domains, but present differential cellular distribution. To add some information concerning the structure and site domains present in Tax-2C we conducted the present study. We have obtained the Tax-2C sequence from 25 different HTLV-2C subjects and analyzed the aminoacid homology between Tax-2B and Tax-2C variants. We found that they differ for amino acidic substitutions in eleven different positions that may affect cellular localization or post-translational modification. Studies on phenotypic properties and cellular localization of Tax-2C are in progress