52 research outputs found
Real-world study of children and young adults with myeloproliferative neoplasms: identifying risks and unmet needs
Myeloproliferative neoplasms (MPNs) are uncommon in children/young adults. Here, we present data on unselected patients diagnosed before 25 years of age included from 38 centers in 15 countries. Sequential patients were included. We identified 444 patients, with median follow-up 9.7 years (0-47.8). Forty-nine (11.1%) had a history of thrombosis at diagnosis, 49 new thrombotic events were recorded (1.16% patient per year [pt/y]), perihepatic vein thromboses were most frequent (47.6% venous events), and logistic regression identified JAK2V617F mutation (P = .016) and hyperviscosity symptoms (visual disturbances, dizziness, vertigo, headache) as risk factors (P = .040). New hemorrhagic events occurred in 44 patients (9.9%, 1.04% pt/y). Disease transformation occurred in 48 patients (10.9%, 1.13% pt/y), usually to myelofibrosis (7.5%) with splenomegaly as a novel risk factor for transformation in essential thrombocythemia (ET) (P= .000) in logistical regression. Eight deaths (1.8%) were recorded, 3 after allogeneic stem cell transplantation. Concerning conventional risk scores: International Prognostic Score for Essential Thrombocythemia-Thrombosis and new International Prognostic Score for Essential Thrombocythemia-Thrombosis differentiated ET patients in terms of thrombotic risk. Both scores identified high-risk patients with the same median thrombosis-free survival of 28.5 years. No contemporary scores were able to predict survival for young ET or polycythemia vera patients. Our data represents the largest real-world study of MPN patients age < 25 years at diagnosis. Rates of thrombotic events and transformation were higher than expected compared with the previous literature. Our study provides new and reliable information as a basis for prospective studies, trials, and development of harmonized international guidelines for the specific management of young patients with MPN
An experimental study on a generalized Maxwell model for nonlinear viscoelastic dampers used in seismic isolation
Long-stroke fluid dampers may be installed under seismic isolation systems to provide supplementary damping. Due to the larger vibration amplitude and velocity, highly nonlinear viscoelastic behavior may exist in a long-stroke fluid damper. In order to accurately simulate the hysteretic behavior of such a damper, this paper presents and experimentally verifies a mathematical model called the generalized Maxwell model (GMM). Similar to the classic Maxwell model, the GMM is composed of a stiffness and a viscous elements connected in series. However, nonlinearity is incorporated into both elements of the GMM by assuming that their resistant forces are exponential functions of the relative velocity and deformation of the damper. By adjusting the two exponential coefficients, the GMM is able to simulate the more complicated viscoelastic behavior of fluid dampers. The GMM is reduced to the Maxwell model when both exponential coefficients are set to one. To verify the GMM, both an element test with harmonic excitations and a shaking table test with seismic excitations were conducted for a long-stroke fluid damper with highly nonlinear viscoelastic behavior. The result of the element test confirms that the GMM model is very accurate in simulating the hysteretic property of the fluid damper under a wide range of excitation frequencies, while the classic Maxwell and the viscous models may only be accurate under a certain excitation frequency. Moreover, the shaking table test, in which the fluid damper is used to provide supplementary damping for a sliding isolation system, demonstrates that the GMM is able to more accurately predict the amount of energy dissipation by the damper and also the peak isolator drift of the isolation system, especially for an earthquake with a long-period pulse. (C) 2011 Published by Elsevier Ltd
Simultaneous occurrence of multiple aetiologies of polycythaemia: renal cell carcinoma, sleep apnoea syndrome, and relative polycythaemia in a smoker with masked polycythaemia rubra vera
A 58 year old male heavy smoker presented with intracranial haemorrhage and erythrocytosis. Four aetiologies of polycythaemia—polycythaemia rubra vera (PRV), renal cell carcinoma, sleep apnoea syndrome, and relative polycythaemia—were found to be associated with the underlying causes of erythrocytosis. He did not fulfill the diagnostic criteria for PRV at initial presentation, but an erythropoietin independent erythroid progenitor assay identified the masked PRV, and the low post-phlebotomy erythropoietin concentration also suggested the likelihood of PRV evolution. This case demonstrates that a search for all the possible causes of erythrocytosis is warranted in patients who already have one aetiology of polycythaemia. Key Words: erythrocytosis • polycythaemia rubra vera • renal cell carcinoma • sleep apnoea syndrome • relative polycythaemia • endogenous erythroid colon
Nonplanar Periodic and Chaotic Oscillation of an Axially Moving Viscoelastic Belt with One-to-One Internal Resonance
Ultrasensitive cell-based bioassay for the measurement of global estrogenic activity of flavonoid mixtures revealing additive, restrictive, and enhanced actions in binary and higher order combinations
10.1089/adt.2007.056Assay and Drug Development Technologies53355-36
The Development of Image-based Distance Measurement System
In this paper, a novel image-based method of distance measurement is proposed. Traditionally, the parallax method is frequently used to measure the distance between the camera and the measured surface. But for diminishing the computational complexity and inaccuracy cause by image processing procedure, the proposed system only using two parallel laser beams project to the measured surface then analyze the information of a captured image to compute the distance. Furthermore, in order to improve the accuracy of the experiment, the proposed algorithm also provides a mechanism to make sure the results will not be influenced by the angle between the optical axis of the camera and measured surface. The experimental results showed the proposed method provided precise measuring results in several different distances
Adsorption of dodecahydroxylated-fullerene monolayers at the air-water interface
We study the adsorption behaviors of dodecahydroxylated-fullerene C-60(OH)(12) at the air-water interface. With the hydrophilicity imposed by the 12 hydroxy groups randomly bounded on the C-60 cage, C-60(OH)(12) can dissolve in water slightly. Surface pressure-area isotherms, Brewster angle microscopy, and neutron reflection results for the aqueous solutions of C-60(OH)(12) provide consistent evidence of adsorbed C-60(OH)(12) monolayers at the air-water interface. A Langmuir-Blodgett film of C-60(OH)(12), prepared from the sample solution with the vertical dipping method, is examined using atomic force microscopy. (C) 2000 Elsevier Science B.V. All rights reserved
Lead time reduction models with defective items subject to a service level constraint
[[abstract]]Recently, several continuous review inventory models have been developed to consider lead time reduction problems but neglected the possible impact of defective items on an arrival order lot. In this study, we attempt to derive a continuous review inventory model with defective items, where the order quantity, reorder point and lead time are viewed as decision variables. Instead of having a stockout cost term in the objective function, a service level constraint is added to the model. The developments in this paper first assume that the lead time demand follows a normal distribution, and then relax this assumption by only assuming that the mean and variance of lead time demand are known. For each case, we develop a procedure to find the optimal solution. Numerical examples are presented to illustrate the proposed models.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]E
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