8 research outputs found

    Solid Couplings With Flexible Intermediate Shafts For High Speed Turbocompressor Trains.

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    LecturePg. 101-110The design and application of solid couplings combined with flexible quill shafts for high speed turbocompressors are presented. Solid couplings are rigid in the axial direction. They transmit any residual thrust from one compressor casing to another, and even into the gear. A single thrust bearing then positions the complete rotor train. Elimination of individual thrust bearings results in a smaller lube-oil system and a reduced power loss. Any additional thrust components from a prestressed flexible-disc coupling or a gear-type coupling (gear lock) are completely avoided. The use of a flexible intermediate shaft (quill shaft) gives the solid coupling the same lateral flexibility as for a geartype or flexible-disc coupling. Criteria for allowable misalignment are given in this paper. A solid coupling is neither exposed to any kind of wear nor endangered by corrosion or stress corrosion so that no maintenance is necessary. Couplings have a decisive influence on rotordynamics. The conventional arrangement of a multicasing train with gear-type or flexible-disc couplings incorporates individual thrust bearings located outboard of the journal bearings (long shaft over hangs). Introducing solid couplings leads to a stiffer rotor by eliminating individual thrust bearings. A comparison of critical speeds of a high-speed/high-power compressor train is made alternatively equipped with solid couplings, flexible-disc or gear-type couplings. The response of the different rotors and couplings to specified unbalance weights is calculated and compared throughout the complete speed range. Torsional and lateral critical frequencies can easily be influenced by modification of intermediate shafts, even after installation of a compressor train. Operating experience on nearly 1500 compressors equipped with solid couplings have proven their excellent reliability especially on high speed, high power turbocompressor applications

    A rapid synthesis of the evidence on interventions supporting self-management for people with long-term conditions. (PRISMS Practical systematic RevIew of Self-Management Support for long-term conditions)

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    Background: Despite robust evidence concerning self-management for some long-term conditions (LTCs), others lack research explicitly on self-management and, consequently, some patient groups may be overlooked. Aim: To undertake a rapid, systematic overview of the evidence on self-management support for LTCs to inform health-care commissioners and providers about what works, for whom, and in what contexts. Methods: Self-management is ‘the tasks . . . individuals must undertake to live with one or more chronic conditions . . . [including] . . . having the confidence to deal with medical management, role management and emotional management of their conditions’. We convened an expert workshop and identified characteristics of LTCs potentially of relevance to self-management and 14 diverse exemplar LTCs (stroke, asthma, type 2 diabetes mellitus, depression, chronic obstructive pulmonary disease, chronic kidney disease, dementia, epilepsy, hypertension, inflammatory arthropathies, irritable bowel syndrome, low back pain, progressive neurological disorders and type 1 diabetes mellitus). For each LTC we conducted systematic overviews of systematic reviews of randomised controlled trials (RCTs) of self-management support interventions (‘quantitative meta-reviews’); and systematic overviews of systematic reviews of qualitative studies of patients’ experiences relating to self-management (‘qualitative meta-reviews’). We also conducted an original systematic review of implementation studies of self-management support in the LTCs. We synthesised all our data considering the different characteristics of LTCs. In parallel, we developed a taxonomy of the potential components of self-management support. Results: We included 30 qualitative systematic reviews (including 515 unique studies), 102 quantitative systematic reviews (including 969 RCTs), and 61 studies in the implementation systematic review. Effective self-management support interventions are multifaceted, should be tailored to the individual, their culture and beliefs, a specific LTC and position on the disease trajectory, and underpinned by a collaborative/communicative relationship between the patient and health-care professional (HCP) within the context of a health-care organisation that actively promotes self-management. Self-management support is a complex intervention and although many components were described and trialled in the studies no single component stood out as more important than any other. Core components include (1) provision of education about the LTC, recognising the importance of understanding patients’ pre-existing knowledge and beliefs about their LTC; (2) psychological strategies to support adjustment to life with a LTC; (3) strategies specifically to support adherence to treatments; (4) practical support tailored to the specific LTC, including support around activities of daily living for disabling conditions, action plans in conditions subject to marked exacerbations, intensive disease-specific training to enable self-management of specific clinical tasks; and (5) social support as appropriate. Implementation requires a whole-systems approach which intervenes at the level of the patient, the HCP and the organisation. The health-care organisation is responsible for providing the means (both training and time/material resources) to enable HCPs to implement, and patients to benefit from, self-management support, regularly evaluating self-management processes and clinical outcomes. More widely there is a societal need to address public understanding of LTCs. The lack of public story for many conditions impacted on patient help-seeking behaviour and public perceptions of need. Conclusions: Supporting self-management is inseparable from the high-quality care for LTCs. Commissioners and health-care providers should promote a culture of actively supporting self-management as a normal, expected, monitored and rewarded aspect of care. Further research is needed to understand how health service managers and staff can achieve this culture change in their health-care organisations. Study registration: This study is registered as PROSPERO CRD42012002898. Funding: The National Institute for Health Research Health Services and Delivery Research programme

    Deep abscopal response to radiotherapy and anti-PD-1 in an oligometastatic melanoma patient with unfavorable pretreatment immune signature

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    Radiotherapy can elicit abscopal effects in non-irradiated metastases, particularly under immune checkpoint blockade (ICB). We report on two elderly patients with oligometastatic melanoma treated with anti-PD-1 and stereotactic body radiation therapy (SBRT). Before treatment, patient 1 showed strong tumor infiltration with exhausted CD8+ T cells and high expression of T cell-attracting chemokines. This patient rapidly mounted a complete response, now ongoing for more than 4.5 years. Patient 2 exhibited low CD8+ T cell infiltration and high expression of immunosuppressive arginase. After the first SBRT, his non-irradiated metastases did not regress and new metastases occurred although neoepitope-specific and differentiation antigen-specific CD8+ T cells were detected in the blood. A second SBRT after 10 months on anti-PD-1 induced a radiologic complete response correlating with an increase in activated PD-1-expressing CD8 T cells. Apart from a new lung lesion, which was also irradiated, this deep abscopal response lasted for more than 2.5 years. However, thereafter, his disease progressed and the activated PD-1-expressing CD8 T cells dropped. Our data suggest that oligometastatic patients, where a large proportion of the tumor mass can be irradiated, are good candidates to improve ICB responses by RT, even in the case of an unfavorable pretreatment immune signature, after progression on anti-PD-1, and despite advanced age. Besides repeated irradiation, T cell epitope-based immunotherapies (e.g., vaccination) may prolong antitumor responses even in patients with unfavorable pretreatment immune signature

    B. Mittelalter und Neuzeit.

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