442 research outputs found

    Low Reynolds number turbulent flows over elastic walls

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    We study the laminar and turbulent channel flow over a viscous hyper-elastic wall and show that it is possible to sustain an unsteady chaotic turbulent-like flow at any Reynolds number by properly choosing the wall elastic modulus. We propose a physical explanation for this effect by evaluating the shear stress and the turbulent kinetic energy budget in the fluid and elastic layer. We vary the bulk Reynolds number from 2800 to 10 and identify two distinct mechanisms for turbulence production. At moderate and high Reynolds numbers, turbulent fluctuations activate the wall oscillations, which, in turn, amplify the turbulent Reynolds stresses in the fluid. At very low Reynolds number, the only production term is due to the energy input from the elastic wall, which increases with the wall elasticity. This mechanism may be exploited to passively enhance mixing in microfluidic devices

    Acoustic Emission from Paper Fracture

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    We report tensile failure experiments on paper sheets. The acoustic emission energy and the waiting times between acoustic events follow power-law distributions. This remains true while the strain rate is varied by more than two orders of magnitude. The energy statistics has the exponent β∼1.25±0.10\beta \sim 1.25 \pm 0.10 and the waiting times the exponent τ∼1.0±0.1\tau \sim 1.0 \pm 0.1, in particular for the energy roughly independent of the strain rate. These results do not compare well with fracture models, for (brittle) disordered media, which as such exhibit criticality. One reason may be residual stresses, neglected in most theories.Comment: 4 pages, 5 figure

    Assessment of molecular recognition element for the quantification of human epidermal growth factor using surface plasmon resonance

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    Background: A method for the selection of suitable molecular recognition element (MRE) for the quantification of human epidermal growth factor (hEGF) using surface plasmon resonance (SPR) is presented. Two types of hEGF antibody, monoclonal and polyclonal, were immobilized on the surface of chip and validated for its characteristics and performance in the quantification of hEGF. Validation of this analytical procedure was to demonstrate the stability and suitability of antibody for the quantification of target protein. Results: Specificity, accuracy and precision for all samples were within acceptable limit for both antibodies. The affinity and kinetic constant of antibodies-hEGF binding were evaluated using a 1:1 Langmuir interaction model. The model fitted well to all binding responses simultaneously. Polyclonal antibody (pAb) has better affinity (KD = 7.39e-10 M) than monoclonal antibody (mAb) (KD = 9.54e-9 M). Further evaluation of kinetic constant demonstrated that pAb has faster reaction rate during sample injection, slower dissociation rate during buffer injection and higher level of saturation state than mAb. Besides, pAb has longer shelf life and greater number of cycle run. Conclusions: Thus, pAb was more suitable to be used as a stable MRE for further quantification works from the consideration of kinetic, binding rate and shelf life assessment

    Being Grateful for My Stupid Little Life : Why We Need Movies

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    More and more I’m convinced the current cultural paradigm leaves us too thin. The practical and objective approach to reality doesn’t attend to the complexity and mystery of the created world; it doesn’t attend to the complexity and mystery of our humanity. Posting about how movies help make sense of our experiences from In All Things - an online hub committed to the claim that the life, death, and resurrection of Jesus Christ has implications for the entire world. http://inallthings.org/being-grateful-for-my-stupid-little-life-why-we-need-movies

    Mutations in LAMB1 Cause Cobblestone Brain Malformation without Muscular or Ocular Abnormalities

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    Cobblestone brain malformation (COB) is a neuronal migration disorder characterized by protrusions of neurons beyond the first cortical layer at the pial surface of the brain. It is usually seen in association with dystroglycanopathy types of congenital muscular dystrophies (CMDs) and ocular abnormalities termed muscle-eye-brain disease. Here we report homozygous deleterious mutations in LAMB1, encoding laminin subunit beta-1, in two families with autosomal-recessive COB. Affected individuals displayed a constellation of brain malformations including cortical gyral and white-matter signal abnormalities, severe cerebellar dysplasia, brainstem hypoplasia, and occipital encephalocele, but they had less apparent ocular or muscular abnormalities than are typically observed in COB. LAMB1 is localized to the pial basement membrane, suggesting that defective connection between radial glial cells and the pial surface mediated by LAMB1 leads to this malformation

    Salvage high-dose chemotherapy in female patients with relapsed/refractory germ-cell tumors: A retrospective analysis of the European Group for Blood and Marrow Transplantation (EBMT)

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    Background: High-dose chemotherapy (HDC) with hematopoietic progenitor cell transplantation is a standard option for relapsed/refractory testicular germ-cell tumor (GCT), but only few data have been reported in female patients with GCT. We conducted a retrospective analysis of female patients with GCT treated with HDC and registered with the European Society for Blood and Marrow Transplantation. Patients and methods: Between 1985 and 2013, 60 registered female patients with GCT, median age 27 years (range 15-48), were treated with salvage HDC. Forty patients (67%) had primary ovarian GCT, 8 (13%) mediastinal, 7 (12%) retroperitoneal and 5 (8%) other primary sites/unknown. Twenty-two patients (37%) received HDC as second-line therapy, 29 (48%) as third-line, and 9 (15%) as fourth- to sixth-line. Nine of 60 patients (15%) received HDC as late-intensification with no evidence of metastasis before HDC. The conditioning HDC regimens comprised carboplatin in 51 of 60 cases (85%), and consisted of a single HDC cycle in 31 cases (52%), a multi-cycle HDC regimen in 29 (48%). Results: Nine cases who underwent late intensification HDC were not evaluable for response. Of the other 51 assessable patients, 17 (33%) achieved a complete response (CR), 8 (16%) a marker-negative partial remission (PRm-), 5 (10%) a marker-positive partial remission, 5 (10%) stable disease, and 13 (25%) progressive disease. There were 3 toxic deaths (6%). With an overall median follow-up of 14 months (range 1-219), 7 of 9 (78%) patients with late intensification and 18 of the 25 patients (72%) achieving a CR/PRm- following HDC were free of relapse/progression. In total, 25 of 60 patients (42%) were progression-free following HDC at a median follow-up of 87 months (range 3-219 months). Conclusions: Salvage HDC based on carboplatin represents a therapeutic option for female patients with relapsed/refractory GCT

    Efficacy and safety of nilotinib as frontline treatment in elderly (> 65 years) chronic myeloid leukemia patients outside clinical trials

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    Here, we report real-world evidence on the safety and efficacy of nilotinib as a first-line treatment in elderly patients with chronic phase CML, treated in 18 Italian centers. Sixty patients aged > 65 years (median age 72 years (65-84)) were reported: 13 patients were older than 75 years. Comorbidities were recorded at baseline in 56/60 patients. At 3 months of treatment, all patients obtained complete hematological response (CHR), 43 (71.6%) an early molecular response (EMR), while 47 (78%) reached a complete cytogenetic response (CCyR). At last follow-up, 63.4% of patients still had a deep molecular response (MR4 or better), 21.6% reached MR3 as best response and 11.6% persisted without MR. Most patients (85%) started the treatment at the standard dose (300 mg BID), maintained at 3 months in 80% of patients and at 6 months in 89% of them. At the last median follow-up of 46.3 months, 15 patients discontinued definitively the treatment (8 due to side effects, 4 died for unrelated CML causes, 1 for failure, 2 were lost to follow-up). One patient entered in treatment-free remission. As to safety, 6 patients (10%) experienced cardiovascular events after a median time of 20.9 months from the start. Our data showed that nilotinib could be, as first-line treatment, effective and relatively safe even in elderly CML patients. In this setting, more data in the long term are needed about possible dose reduction to improve the tolerability, while maintaining the optimal molecular response
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