Analytical Prediction and Experimental Verification of Blade Loads Experienced by Two, Three-Bladed, Fixed Pitch, Horizontal Axis Wind Turbines

Wind turbine blade structural designers need measured blade structural load data to project blade life. These data are necessary to validate analytical predicton models and to optimize advanced blade structural designs. The objective of this work is to furnish designers current blade load data and to compare the analytical blade load predictions to the measured loads. This analysis is based on ninety hours of wind turbine loads data collected in 1990, on the SERI 7.9 m and Aerostar 7.5 m blades. The blades were installed on identical turbines, located adjacent to each other. The data were collected covering a wide range of atmospheric conditions. The data were characterized based on several meteorological parameters that are well correlated with loads, including atmospheric stability, turbulence level, and mean wind speed. As part of this effort, measured blade flapwise and edgewise bending moments were compared to FLAP: an analytical computer prediction model, developed at the Solar Energy Research Institute. Four mean wind speed data sets: 12, 17, 22, and 27 mph, were used in the load comparisons. The methodology included experimental determination of two important, but often difficult to model, input parameters: blade mass and stiffness distributions. From the ninety hours of test data, 409 valid 10-minut

Quality of life in the follow-up of uveal melanoma patients after CyberKnife treatment

To assess quality of life in uveal melanoma patients within the first and second year after CyberKnife radiosurgery. Overall, 91 uveal melanoma patients were evaluated for quality of life through the Short-form (SF-12) Health Survey at baseline and at every follow-up visit over 2 years after CyberKnife radiosurgery. Statistical analysis was carried out using SF Health Outcomes Scoring Software and included subgroup analysis of patients developing secondary glaucoma and of patients maintaining a best corrected visual acuity (BCVA) of the treated eye of 0.5 log(MAR) or better. Analysis of variance, Greenhouse-Geisser correction, Student's t-test, and Fisher's exact test were used to determine statistical significance. Physical Functioning (PF) and Role Physical (RP) showed a significant decrease after CyberKnife radiosurgery, whereas Mental Health (MH) improved (P=0.007, P<0.0001 and P=0.023). MH and Social Functioning (SF) increased significantly (P=0.0003 and 0.026) in the no glaucoma group, MH being higher compared with glaucoma patients (P=0.02). PF and RP were significantly higher in patients with higher BCVA at the second follow-up (P=0.02). RP decreased in patients with BCVA<0.5 log(MAR) (P=0.013). Vitality (VT) increased significantly in patients whose BCVA could be preserved (P=0.031). Neither tumor localization nor size influenced the development of secondary glaucoma or change in BCVA. Although PF and RP decreased over time, MH improved continuously. Prevention of secondary glaucoma has a significant influence on both SF and MH, whereas preservation of BCVA affects VT. Emotional stability throughout follow-up contributes positively toward overall quality of life. CyberKnife radiosurgery may contribute to attenuation of emotional distress in uveal melanoma patients

Inhibition of cholesterol recycling impairs cellular PrPSc propagation

The infectious agent in prion diseases consists of an aberrantly folded isoform of the cellular prion protein (PrPc), termed PrPSc, which accumulates in brains of affected individuals. Studies on prion-infected cultured cells indicate that cellular cholesterol homeostasis influences PrPSc propagation. Here, we demonstrate that the cellular PrPSc content decreases upon accumulation of cholesterol in late endosomes, as induced by NPC-1 knock-down or treatment with U18666A. PrPc trafficking, lipid raft association, and membrane turnover are not significantly altered by such treatments. Cellular PrPSc formation is not impaired, suggesting that PrPSc degradation is increased by intracellular cholesterol accumulation. Interestingly, PrPSc propagation in U18666A-treated cells was partially restored by overexpression of rab 9, which causes redistribution of cholesterol and possibly of PrPSc to the trans-Golgi network. Surprisingly, rab 9 overexpression itself reduced cellular PrPSc content, indicating that PrPSc production is highly sensitive to alterations in dynamics of vesicle trafficking

Quinpramine Ameliorates Rat Experimental Autoimmune Neuritis and Redistributes MHC Class II Molecules

Activation of inflammatory cells is central to the pathogenesis of autoimmune demyelinating diseases of the peripheral nervous system. The novel chimeric compound quinpramine—generated from imipramine and quinacrine—redistributes cholesterol rich membrane domains to intracellular compartments. We studied the immunological and clinical effects of quinpramine in myelin homogenate induced Lewis rat experimental autoimmune neuritis (EAN), a model system for acute human inflammatory neuropathies, such as the Guillain-Barré syndrome. EAN animals develop paresis of all limbs due to autoimmune inflammation of peripheral nerves. Quinpramine treatment ameliorated clinical disease severity of EAN and infiltration of macrophages into peripheral nerves. It reduced expression of MHC class II molecules on antigen presenting cells and antigen specific T cell proliferation both in vitro and in vivo. Quinpramine exerted its anti-proliferatory effect on antigen presenting cells, but not on responder T cells. Our data suggest that quinpramine represents a candidate pharmaceutical for inflammatory neuropathies

Identification of an Intracellular Site of Prion Conversion

Prion diseases are fatal, neurodegenerative disorders in humans and animals and are characterized by the accumulation of an abnormally folded isoform of the cellular prion protein (PrPC), denoted PrPSc, which represents the major component of infectious scrapie prions. Characterization of the mechanism of conversion of PrPC into PrPSc and identification of the intracellular site where it occurs are among the most important questions in prion biology. Despite numerous efforts, both of these questions remain unsolved. We have quantitatively analyzed the distribution of PrPC and PrPSc and measured PrPSc levels in different infected neuronal cell lines in which protein trafficking has been selectively impaired. Our data exclude roles for both early and late endosomes and identify the endosomal recycling compartment as the likely site of prion conversion. These findings represent a fundamental step towards understanding the cellular mechanism of prion conversion and will allow the development of new therapeutic approaches for prion diseases

Minimally invasive total knee replacement : techniques and results

In this review, we outlined the definition of minimally invasive surgery (MIS) in total knee replacement (TKR) and described the different surgical approaches reported in the literature. Afterwards we went through the most recent studies assessing MIS TKR. Next, we searched for potential limitations of MIS knee replacement and tried to answer the following questions: Are there selective criteria and specific patient selection for MIS knee surgery? If there are, then what are they? After all, a discussion and conclusion completed this article. There is certainly room for MIS or at least less invasive surgery (LIS) for appropriate selected patients. Nonetheless, there are differences between approaches. Mini medial parapatellar is easy to master, quick to perform and potentially extendable, whereas mini subvastus and mini midvastus are trickier and require more caution related to risk of hematoma and VMO nerve damage. Current evidence on the safety and efficacy of mini-incision surgery for TKR does not appear fully adequate for the procedure to be used without special arrangements for consent and for audit or continuing research. There is an argument that a sudden jump from standard TKR to MIS TKR, especially without computer assistance such as navigation, patient specific instrumentation (PSI) or robotic, may breach a surgeon's duty of care toward patients because it exposes patients to unnecessary risks. As a final point, more evidence is required on the long-term safety and efficacy of this procedure which will give objective shed light on real benefits of MIS TKR