196 research outputs found
Flight, Wind Tunnel, and Numerical Experiments with a Slender Cone at Incidence
The three-dimensional leeward separation about a 5-deg semi-angle cone of 11 deg angle of incidence was Investigated in night, in the wind tunnel, and by numerical computations. The test conditions were Mach numbers of 0.6, 1.5, and 1.8 at Reynolds numbers between 7 and 10 million based on freestream conditions and a 76.2-cm (30-in.) length of surface. The surface pressure conditions measured included those of fluctuating and mean static, as well as recovery pressures generated by obstacle blocks to provide skin friction and separation-line locations. The mean static pressures from flight and wind tunnel were in reasonably good agreement. The computed results gave the same distributions, but were slightly more positive in magnitude. The experimentally measured primary and secondary separation line locations compared closely with computed results. There were substantial differences In level between the surface root-mean-square pressure fluctuations obtained in night and in the wind tunnel, due, It Is thought, to a relatively high acoustic disturbance level in the tunnel compared with the quiescent atmospheric conditions in night
Paget's Osteosarcoma â no Cure in Sight
Purpose Paget' s osteosarcoma has a fearful reputation with a quoted
survival of at best 5% at 5 years.We therefore reviewed our experience of 26 patients treated
over the last 25 years using modern staging and limb salvage techniques to see if there had
been any improvement in survival
Predicting Mid-Life Capital Formation with Pre-School Delay of Gratification and Life-Course Measures of Self-Regulation
How well do pre-school delay of gratification and life-course measures of self-regulation predict mid-life capital formation? We surveyed 113 participants of the 1967â1973 Bing pre-school studies on delay of gratification when they were in their late 40âs. They reported 11 mid-life capital formation outcomes, including net worth, permanent income, absence of high-interest debt, forward-looking behaviors, and educational attainment. To address multiple hypothesis testing and our small sample, we pre-registered an analysis plan of wellâpowered tests. As predicted, a newly constructed and pre-registered measure derived from preschool delay of gratification does not predict the 11 capital formation variables (i.e., the sign-adjusted average correlation was 0.02). A pre-registered composite self-regulation index, combining preschool delay of gratification with survey measures of self-regulation collected at ages 17, 27, and 37, does predict 10 of the 11 capital formation variables in the expected direction, with an average correlation of 0.19. The inclusion of the preschool delay of gratification measure in this composite index does not affect the index\u27s predictive power. We tested several hypothesized reasons that preschool delay of gratification does not have predictive power for our mid-life capital formation variables
Ibuprofen ingestion does not affect markers of post-exercise muscle inflammation
PURPOSE: We investigated if oral ingestion of ibuprofen influenced leucocyte recruitment and infiltration following an acute bout of traditional resistance exercise Methods: Sixteen male subjects were divided into two groups that received the maximum over-the-counter dose of ibuprofen (1200mg d(-1)) or a similarly administered placebo following lower body resistance exercise. Muscle biopsies were taken from m.vastus lateralis and blood serum samples were obtained before and immediately after exercise, and at 3 and 24 h after exercise. Muscle cross-sections were stained with antibodies against neutrophils (CD66b and MPO) and macrophages (CD68). Muscle damage was assessed via creatine kinase and myoglobin in blood serum samples, and muscle soreness was rated on a ten-point pain scale. RESULTS: The resistance exercise protocol stimulated a significant increase in the number of CD66b(+) and MPO(+) cells when measured 3 h post exercise. Serum creatine kinase, myoglobin and subjective muscle soreness all increased post-exercise. Muscle leucocyte infiltration, creatine kinase, myoglobin and subjective muscle soreness were unaffected by ibuprofen treatment when compared to placebo. There was also no association between increases in inflammatory leucocytes and any other marker of cellular muscle damage. CONCLUSION: Ibuprofen administration had no effect on the accumulation of neutrophils, markers of muscle damage or muscle soreness during the first 24 h of post-exercise muscle recovery
Acute Resistance Exercise Induces Sestrin2 Phosphorylation and p62 Dephosphorylation in Human Skeletal Muscle
Sestrins (1, 2, 3) are a family of stress-inducible proteins capable of attenuating oxidative stress, regulating metabolism, and stimulating autophagy. Sequestosome1 (p62) is also a stress-inducible multifunctional protein acting as a signaling hub for oxidative stress and selective autophagy. It is unclear whether Sestrin and p62Ser403 are regulated acutely or chronically by resistance exercise (RE) or training (RT) in human skeletal muscle. Therefore, the acute and chronic effects of RE on Sestrin and p62 in human skeletal muscle were examined through two studies. In Study 1, nine active men (22.1 ± 2.2 years) performed a bout of single-leg strength exercises and muscle biopsies were collected before, 2, 24, and 48 h after exercise. In Study 2, 10 active men (21.3 ± 1.9 years) strength trained for 12 weeks (2 days per week) and biopsies were collected pre- and post-training. Acutely, 2 h postexercise, phosphorylation of p62Ser403 was downregulated, while there was a mobility shift of Sestrin2, indicative of increased phosphorylation. Forty-eight hours postexercise, the protein expression of both Sestrin1 and total p62 increased. Chronic exercise had no impact on the gene or protein expression of Sestrin2/3 or p62, but Sestrin1 protein was upregulated. These findings demonstrated an inverse relationship between Sestrin2 and p62 phosphorylation after a single bout of RE, indicating they are transiently regulated. Contrarily, 12 weeks of RT increased protein expression of Sestrin1, suggesting that despite the strong sequence homology of the Sestrin family, they are differentially regulated in response to acute RE and chronic RT
Control of rotorcraft retreating blade stall using air-jet vortex generators
A series of low-speed wind tunnel tests were carried out on an oscillating airfoil fitted with two rows of air-jet vortex generators (AJVGs). The airfoil used had an RAE 9645 section and the two spanwise arrays of AJVGs were located at x/c=0.12 and 0.62. The devices and their distribution were chosen to assess their ability to modify/control dynamic stall; the goal being to enhance the aerodynamic performance of helicopter rotors on the retreating blade side of the disc. The model was pitched about the quarter chord with a reduced frequency
(k) of 0.1 in a sinusoidal motion defined by a=15o+10sin_ t. The measured data indicate that, for continuous blowing from the front row of AJVGs with a momentum blowing coefficient (C μ) greater than 0.008, modifications to the stalling process are encouraging. In particular, the pitching moment behavior exhibits delayed stall and there is a marked reduction in the normal force hysteresis
Characterization of large in-frame von Willebrand factor deletions highlights differing pathogenic mechanisms
Copy number variation (CNV) is known to cause all von Willebrand disease (VWD) types, although the associated pathogenic mechanisms involved have not been extensively studied. Notably, in-frame CNV provides a unique opportunity to investigate how specific von Willebrand factor (VWF) domains influence the processing and packaging of the protein. Using multiplex ligation-dependent probe amplification, this study determined the extent to which CNV contributed to VWD in the Molecular and Clinical Markers for the Diagnosis and Management of Type 1 von Willebrand Disease cohort, highlighting in-frame deletions of exons 3, 4-5, 32-34, and 33-34. Heterozygous in vitro recombinant VWF expression demonstrated that, although deletion of exons 3, 32-34, and 33-34 all resulted in significant reductions in total VWF (P < .0001, P < .001, and P < .01, respectively), only deletion of exons 3 and 32-34 had a significant impact on VWF secretion (P < .0001). High-resolution microscopy of heterozygous and homozygous deletions confirmed these observations, indicating that deletion of exons 3 and 32-34 severely impaired pseudo-Weibel-Palade body (WPB) formation, whereas deletion of exons 33-34 did not, with this variant still exhibiting pseudo-WPB formation similar to wild-type VWF. In-frame deletions in VWD, therefore, contribute to pathogenesis via moderate or severe defects in VWF biosynthesis and secretion
Genetic analysis of haemophilia A in Bulgaria
BACKGROUND: Haemophilias are the most common hereditary severe disorders of blood clotting. In families afflicted with heamophilia, genetic analysis provides opportunities to prevent recurrence of the disease. This study establishes a diagnostical strategy for carriership determination and prenatal diagnostics of haemophilia A in Bulgarian haemophilic population. METHODS: A diagnostical strategy consisting of screening for most common mutations in the factor VIII gene and analysis of a panel of eight linked to the factor VIII gene locus polymorphisms was established. RESULTS: Polymorphic analysis for carrier status determination of haemophilia A was successful in 30 families out of 32 (94%). Carrier status was determined in 25 of a total of 28 women at risk (89%). Fourteen prenatal diagnoses in women at high risk of having a haemophilia A â affected child were performed, resulting in 6 healthy boys and 5 girls. CONCLUSION: The compound approach proves to be a highly informative and cost-effective strategy for prevention of recurrence of haemophilia A in Bulgaria. DNA analysis facilitates carriership determination and subsequent prenatal diagnosis in the majority of Bulgarian families affected by haemophilia A
Inhibiting ERK Activation with CI-1040 Leads to Compensatory Upregulation of Alternate MAPKs and Plasminogen Activator Inhibitor-1 following Subtotal Nephrectomy with No Impact on Kidney Fibrosis
Extracellular-signal regulated kinase (ERK) activation by MEK plays a key role in many of the cellular processes that underlie progressive kidney fibrosis including cell proliferation, apoptosis and transforming growth factor ÎČ1-mediated epithelial to mesenchymal transition. We therefore assessed the therapeutic impact of ERK1/2 inhibition using a MEK inhibitor in the rat 5/6 subtotal nephrectomy (SNx) model of kidney fibrosis. There was a twentyfold upregulation in phospho-ERK1/2 expression in the kidney after SNx in Male Wistar rats. Rats undergoing SNx became hypertensive, proteinuric and developed progressive kidney failure with reduced creatinine clearance. Treatment with the MEK inhibitor, CI-1040 abolished phospho- ERK1/2 expression in kidney tissue and prevented phospho-ERK1/2 expression in peripheral lymphocytes during the entire course of therapy. CI-1040 had no impact on creatinine clearance, proteinuria, glomerular and tubular fibrosis, and α-smooth muscle actin expression. However, inhibition of ERK1/2 activation led to significant compensatory upregulation of the MAP kinases, p38 and JNK in kidney tissue. CI-1040 also increased the expression of plasminogen activator inhibitor-1 (PAI-1), a key inhibitor of plasmin-dependent matrix metalloproteinases. Thus inhibition of ERK1/2 activation has no therapeutic effect on kidney fibrosis in SNx possibly due to increased compensatory activation of the p38 and JNK signalling pathways with subsequent upregulation of PAI-1
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