bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurements of plasma metanephrines by immunoassay vs liquid chromatography with tandem mass spectrometry for diagnosis of pheochromocytoma
Authors: Weismann Dirk , Peitzsch Mirko , Raida Anna , Prejbisz Aleksander , Gosk Maria , Riester Anna , Willenberg Holger S , Klemm Reiner , Manz Georg , Deutschbein Timo , Kroiss Matthias , Därr Roland , Bidlingmaier Martin , Januszewicz Andrzej , Eisenhofer Graeme , Fassnacht Martin 
Published: December 2014

BackgroundReports conflict concerning measurements of plasma metanephrines (MNs) for diagnosis of pheochromocytomas/paragangliomas (PPGLs) by immunoassays compared with other methods. We aimed to compare the performance of a commercially available enzyme-linked immunoassay (EIA) kit with liquid chromatography–tandem mass spectrometric (LC–MS/MS) measurements of MNs to diagnose PPGLs.MethodsIn a substudy of a prospective, multicenter trial to study the biochemical profiles of monoamine-producing tumors, we included 341 patients (174 males and 167 females) with suspected PPGLs (median age 54 years), of whom 54 had confirmed PPGLs. Plasma MNs were measured by EIA and LC–MS/MS, each in a specialized laboratory.ResultsPlasma normetanephrine (NMN) and MN were measured 60 and 39% lower by EIA than by LC–MS/MS. Using upper cut-offs stipulated for the EIA, diagnostic sensitivity was only 74.1% at a specificity of 99.3%. In contrast, use of similar cut-offs for MN and overall lower age-adjusted cut-offs for NMN measured by LC–MS/MS returned a diagnostic sensitivity and specificity of 98.1 and 99.7%. Areas under receiver-operating characteristic curves, nevertheless, indicated comparable diagnostic performance of the EIA (0.993) and LC–MS/MS (0.985). Diagnostic sensitivity for the EIA increased to 96.2% with a minimal loss in specificity (95.1%) following use of cut-offs for the EIA adapted to correct for the negative bias.ConclusionsThe EIA underestimates plasma MNs and diagnostic sensitivity is poor using commonly stipulated cut-offs, resulting in a high risk for missing patients with PPGLs. Correction of this shortcoming can be achieved by appropriately determined cut-offs resulting in comparable diagnostic performance of EIA and LC–MS/MS assays.
Parallel Profiling of Fission Yeast Deletion Mutants for Proliferation and for Lifespan During Long-Term Quiescence
Authors: Sideri Theodora , Rallis Charalampos , Bitton Danny A , Lages Bruno M , Suo Fang , Rodríguez-López María , Du Li-Lin , Bähler Jürg 
Published: December 2014

Abstract
Genetic factors underlying aging are remarkably conserved from yeast to human. The fission yeast Schizosaccharomyces pombe is an emerging genetic model to analyze cellular aging. Chronological lifespan (CLS) has been studied in stationary-phase yeast cells depleted for glucose, which only survive for a few days. Here, we analyzed CLS in quiescent S. pombe cells deprived of nitrogen, which arrest in a differentiated, G0-like state and survive for more than 2 months. We applied parallel mutant phenotyping by barcode sequencing (Bar-seq) to assay pooled haploid deletion mutants as they aged together during long-term quiescence. As expected, mutants with defects in autophagy or quiescence were under-represented or not detected. Lifespan scores could be calculated for 1199 mutants. We focus the discussion on the 48 most long-lived mutants, including both known aging genes in other model systems and genes not previously implicated in aging. Genes encoding membrane proteins were particularly prominent as pro-aging factors. We independently verified the extended CLS in individual assays for 30 selected mutants, showing the efficacy of the screen. We also applied Bar-seq to profile all pooled deletion mutants for proliferation under a standard growth condition. Unlike for stationary-phase cells, no inverse correlation between growth and CLS of quiescent cells was evident. These screens provide a rich resource for further studies, and they suggest that the quiescence model can provide unique, complementary insights into cellular aging.
Mean of the Typical Decoding Rates: A New Translation Efficiency Index Based on the Analysis of Ribosome Profiling Data
Authors: Dana Alexandra , Tuller Tamir 
Published: December 2014

Abstract
Gene translation modeling and prediction is a fundamental problem that has numerous biomedical implementations. In this work we present a novel, user-friendly tool/index for calculating the mean of the typical decoding rates that enables predicting translation elongation efficiency of protein coding genes for different tissue types, developmental stages, and experimental conditions. The suggested translation efficiency index is based on the analysis of the organism’s ribosome profiling data. This index could be used for example to predict changes in translation elongation efficiency of lowly expressed genes that usually have relatively low and/or biased ribosomal densities and protein levels measurements, or can be used for example for predicting translation efficiency of new genetically engineered genes. We demonstrate the usability of this index via the analysis of six organisms in different tissues and developmental stages. Distributable cross platform application and guideline are available for download at: http://www.cs.tau.ac.il/~tamirtul/MTDR/MTDR_Install.html
Neuroimaging and Neurodevelopmental Outcome in Extremely Preterm Infants
Authors: Hintz Susan R. , Barnes Patrick D. , Bulas Dorothy , Slovis Thomas L. , Finer Neil N. , Wrage Lisa A. , Das Abhik , Tyson Jon E. , Stevenson David K. , Carlo Waldemar A. , Walsh Michele C. , Laptook Abbot R. , Yoder Bradley A. , Van Meurs Krisa P. , Faix Roger G. , Rich Wade , Newman Nancy S. , Cheng Helen , Heyne Roy J. , Vohr Betty R. , Acarregui Michael J. , Vaucher Yvonne E. , Pappas Athina , Peralta-Carcelen Myriam , Wilson-Costello Deanne E. , Evans Patricia W. , Goldstein Ricki F. , Myers Gary J. , Poindexter Brenda B. , McGowan Elisabeth C. , Adams-Chapman Ira , Fuller Janell , Higgins Rosemary D. ,   for the SUPPORT Study Group of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network
Published: December 2014

BACKGROUND:
Extremely preterm infants are at risk for neurodevelopmental impairment (NDI). Early cranial ultrasound (CUS) is usual practice, but near-term brain MRI has been reported to better predict outcomes. We prospectively evaluated MRI white matter abnormality (WMA) and cerebellar lesions, and serial CUS adverse findings as predictors of outcomes at 18 to 22 months’ corrected age.

METHODS:
Early and late CUS, and brain MRI were read by masked central readers, in a large cohort (n = 480) of infants &lt;28 weeks’ gestation surviving to near term in the Neonatal Research Network. Outcomes included NDI or death after neuroimaging, and significant gross motor impairment or death, with NDI defined as cognitive composite score &lt;70, significant gross motor impairment, and severe hearing or visual impairment. Multivariable models evaluated the relative predictive value of neuroimaging while controlling for other factors.

RESULTS:
Of 480 infants, 15 died and 20 were lost. Increasing severity of WMA and significant cerebellar lesions on MRI were associated with adverse outcomes. Cerebellar lesions were rarely identified by CUS. In full multivariable models, both late CUS and MRI, but not early CUS, remained independently associated with NDI or death (MRI cerebellar lesions: odds ratio, 3.0 [95% confidence interval: 1.3–6.8]; late CUS: odds ratio, 9.8 [95% confidence interval: 2.8–35]), and significant gross motor impairment or death. In models that did not include late CUS, MRI moderate-severe WMA was independently associated with adverse outcomes.

CONCLUSIONS:
Both late CUS and near-term MRI abnormalities were associated with outcomes, independent of early CUS and other factors, underscoring the relative prognostic value of near-term neuroimaging.
Calculation of loading-induced tendon slip in beams prestressed with external tendons. Part I: Experiment
Authors: Diep Bui Khac , Quang Lam Huu 
Published: December 2014

This study consists of two parts, in which both experimental and numerical studies on externally prestressed concrete beams were investigated. In Part I, three identical beams of T-shaped section prestressed with external tendons have been tested to failure to investigate the effects of geometry of the applied load on flexural behavior of externally prestressed concrete beams. The tendon slip at deviators was also monitored in order to examine the evolution of stress in the external tendons. Test results were presented with emphasis on the effects of geometry of applied load and tendon slip at deviators.
Dynamic analysis of prestressed Bernoulli beams resting on two-parameter foundation under moving harmonic load
Authors: Kien Nguyen Dinh , Hai Bui Thanh 
Published: December 2014

This paper describes the dynamic analysis of prestressed Bernoulli beams resting on a two-parameter elastic foundation under a moving harmonic load by the finite element method. Using the cubic Hermitian polynomials as interpolation functions for the deflection, the stiffness of the Bernoulli beam element augmented by that of the foundation support and prestress is formulated. The nodal load vector is derived using the polynomials with the abscissa measured from the left-hand node of the current loading element to the position of the moving load. Using the formulated element, the dynamic response of the beams is computed with the aid of the direct integration Newmark method. The effects of the foundation support, prestress as well as excitation frequency, velocity and acceleration on the dynamic characteristics of the beams are investigated in detail and highlighted.
The method of transmission matrix for investigating planar mechanisms
Authors: Sanh Do , Khoa Do Dang 
Published: December 2014

In this paper the method of transmission matrix is applied for investigating planar mechanisms [5-7]. As is known, in many engineering problems, for example, in the problem of synthesis and analysis of motion, the following problem is more and more interested. There is an object (a particle or body) connected with a frame of reference, which moves with respect to another frame. It is necessary to define the configuration (the position, velocity, acceleration) of the object under consideration in the latter frame. There are two types of the frame of reference. A frame that is fixed in time named inertia frame or global frame of reference and the frame attached to each body of the system- the body frame of reference. The problem is stated now as follows: Determine the configuration in global frame of a particle fixed in any body of the system.In this paper a method is constructed for solving such a problem by means of transmission matrices.The obtained results are illustrated by examples.
An alternative method for determining the coefficient of thermal expansion of composite material of spherical particles
Authors: Duc Nguyen Dinh , Tung Hoang Van , Hang Do Thanh 
Published: December 2014

Composite material is widely used in modern structures. Many researchers have been involved in studying, developing and applying this kind of material. The composite material of spherical particles is a material composed of continuous matrix phase and spherical particles. In modern technique, it is very necessary to consider the influence of temperature on toughness and stability of structures. Therefore, determining the coefficient of thermal expansion of composite as a function of the coefficients and volume fractions of matrix and particle phases is a practical requirement. In this paper. we would like to introduce an alternative derivation method in order to obtain the thermal expansion coefficient of two-phase composite of spherical particles. Our results are the same as Vanin's and other authors'.
Influence of trajectories on the joint torques of kinematically redundant manipulators
Authors: Khang Nguyen Van , Tuan Do Anh , Dien Nguyen Phong , Nam Tran Hoang 
Published: December 2014

This paper presents an algorithm for solving the inverse dynamics problem of redundant manipulators using MAPLE software. The method has the advantage of generating efficient symbolic solutions which reduces the computational cost. The influence of trajectories on the joint torques of redundant manipulators is considered. The theory is illustrated by the numerical simulation of a redundant four-link planar manipulator.
A Cauchy like problem in plane elasticity
Authors: Ang Dang Dinh , Dung Nguyen 
Published: December 2014

Let \(\Omega \) be a bounded domain in the plane, representing an elastic body. Let \(\Gamma_0 \) be a portion of the boundary \(\Gamma\) of \(\Omega \), \(\Gamma_0 \) being assumed to be paralled to the \(x\)-axis. It is proposed to determine the stress field in \(\Omega \) from the displacements and surface stresses given on \(\Gamma_0 \). Under the assumption of plane stress, it is shown that \(u_x + u_y\) is a harmonic function. An Airy stress function is introduced, from which the stress field is computed.
On a feedback-feedforward identification control algorithm for feedback active controlled structures
Authors: Viet La Duc , Anh Nguyen Dong 
Published: December 2014

Linear quadratic regulator (LQR) is an effective method of feedback active control theory. However, the LQR control is not truly optimal because it is only a feedback algorithm, i.e. the external excitation term is ignored in the optimal equation. In a previous paper [1], the identification algorithm is presented for feedback active controlled systems to identify the excitation from the structural response measured. The aim of this paper is to propose a feedback-feedforward control algorithm using the identified excitation to improve the classical LQR control. A numerical simulation is applied to an eight story building subjected to base acceleration and controlled by active mass damper system.
Research on aerodynamics of a wing-in-surface-effect ship by theory and experiment
Authors: Tang Pham Xuan , Thang Ngo Tri , Uy Pham Vu , Hai Duong Ngoc 
Published: December 2014

The paper presents the results of theoretical and experimental studies of the aerodynamic characteristics of a wing-in-surface-effect ship (WISES), which was made under coordination of the Institute of Mechanics, Vietnamese Academy of Science and Technology. The theoretical researches are carried out by the half analytical method and together by the linear and nonlinear vortex lattice methods. The experiment was conducted by the model on wind tunnel OTl of The Technical Institute of Air Force - Air Defense.
Construction, verification of a software for the 2D dam-break flow and some its applications
Authors: Lai Hoang Van , Don Nguyen Thanh 
Published: December 2014

In this paper the numerical method for the shallow water equations is studied. The paper consists of 3 sections. In the section 1 the theoretical basis and software IMECI-L2DBREAK for simulation of the 2D dam-break or dyke-break flows is outlined. In the section 2 some results in verification of the IMECH_2DBREAK by the test cases proposed in the big European Hydraulics Laboratories are shown. In the last section some applications of IMECH_2DBREAK for the inundation problem in the Red river delta in the Northern of Vietnam are presented.
Non-linear vibration of eccentrically stiffened laminated composite shells
Authors: Bich Dao Huy , Long Vu Do 
Published: December 2014

The present paper deals with a non-linear vibration of eccentrically stiffened laminated composite doubly curved shallow shells. The calculations of internal forces and displacements of the shell are based upon the thin shell theory considering the geometrical non-linearity and the Lekhnitsky's smeared stiffeners technique. From the deformation compatibility equation and the motion equation a system of partial differential equations for stress function and deflection of shell is obtained. The Bubnov-Galerkin's method and iterative procedure in conjunction with Newmark constant acceleration scheme are used for dynamical analysis of shells to give the frequency-amplitude relation of free nonlinear vibration and non-linear transient responses. Numerical results show the influence of boundary conditions and Gauss curvature on the non-linear vibration of shells.
Experimental results of gaslift process
Authors: Hai Duong Ngoc , Thien Nguyen Duy , Canh Nguyen Van 
Published: December 2014

In the paper, the investigation results of periodical gas-lift flows in vertical pipes using experiment method are presented. The experiment facilities consist of flow measurement equipment, gas and fluid supplier facilities, tubing system. To study the influence of medium physical and dynamical characteristics on the process efficiency, two liquid-gas systems are used, namely, water-air and spindle oil-air. The objects of investigation are to obtain data from tests conducted in some conduits and to analyse the influence of system physical, geometrical and etc. parameters such as: initial liquid height in the conduits, gas injected volume, conduit diameter, conduit configuration and etc. on the considered process.
Analysis of stiffened laminated composite plates by finite element based on higher-order displacement theory
Authors: Thinh Tran Ich , Quoc Tran Huu 
Published: December 2014

In this paper, authors use a finite element model based on higher-order displacement plate theory for analysis of stiffened laminated composite plates. Transverse shear deformation is included in the formulation making the model applicable for both moderately thick and thin composite plates. The plate element used is a nine-noded isoparametric one with nine degrees of freedom at each node. The stiffness of stiffener is reflected at all nine nodes of plate element in which it is placed. Accordingly, the stiffeners can be positioned anywhere within the place element. Free vibration and deflection of stiffened laminated composite plates are carried out, and results are compared with existing analytical and other solutions.
Crack analysis for some structures subjected to thermal and dynamic loads
Authors: Nhu Ngo Huong 
Published: December 2014

Numerical methods of crack analysis for some 2D-elasticity problems with thermal and dynamic loads are considered in this work. The general steps of the algorithm are presented. Some programs are written by Gibian languages in the codes Castem for crack analysis of different structures. Numerical illustrations are realized for the crack dam model, the plate with one and two cracks the plate with crack at the hole subjected to under variable tension of thermal loads. The influence of the temperature, dynamic loads or position of the crack on fracture parameters for these structures are investigated. The given programs may be useful for estimating the failure of dams, tunnels or other structures.
Thermal buckling of imperfect functionally graded cylindrical shells according to Wan-Donnell model
Authors: Tung Hoang Van , Duc Nguyen Dinh 
Published: December 2014

A thermal buckling analysis of imperfect circular cylindrical shells of functionally graded material is considered. The material properties are assumed varying as a power form of thickness coordinate variable. The Donnell equilibrium and stability equations are considered and the Wan-Donnell model for initial geometrical imperfection is adopted. The thermal loads include the uniform temperature rise and nonlinear temperature change across the thickness of shell. A closed form solution for the thermal buckling of simply supported cylindrical FG shell under the described thermal loads is obtained. The influences of the relative thickness, the imperfection size and the power law index on buckling thermal loads are all discussed.
Slip-shakedown analysis and the assumption of small coupling in frictional contact
Authors: Antoni Nicolas , Son Nguyen Quoc 
Published: December 2014

In the frictional contact of solids under cyclic loads, the shakedown behaviour of the relative displacement is of interest in the same spirit as the plastic deformation in plasticity. Cumulative slips may lead to the failure due to large relative displacements of the components of an assembly while cyclic slips are often undesired because of wear and fretting÷fatigue problems. Under Coulomb friction, it is well known that Melan and Koiter theorems are generally not available, except in certain particular cases. In this discussion, the particular case of small coupling between the contact pressures and the slip-displacements is considered. This assumption means that the tangent displacements have small or no influence on the contact pressures which can be then computed from the elastic response as in the uncoupling case. The pressure is thus a given time-dependent function and the Coulomb criterion is reduced to a Mises-like standard law of friction. It is shown here that Melan and Koiter theorems can be applied again as in standard plasticity. The dependence of the yield limit on the loading amplitude is however not classical and the extension of the static and kinematic approaches is discussed to obtain the critical shakedown load or the limit load. The validity of the assumption of small coupling is also explored by numerical simulation in a practical example.
On the solutions of the Mathieu’s equation
Authors: Bich Dao Huy , Bich Nguyen Dang , Tuan Nguyen Anh 
Published: December 2014

As shown in [1] solutions of the Mathieu’s equation were classified on three fundamental kinds depending mainly on its parameters. These solutions were constructed in the form of infinite series. This paper presents a new approach in which approximated analytical solutions of the Mathieu’s equation are constructed in the finite form. Depending on parameters of Mathieu’s equations general solutions may obtain following behaviors: either bounded almost periodic, or infinitely increased combining with infinitely decreased and or infinitely increased combining with periodic.
An interesting material that appears to be fit to possibly all future mechanical vibration textbooks
Authors: Elishakoff Isaac 
Published: December 2014

A material is suggested for future mechanical vibration textbooks. Both mathematically and conceptually it is simpler than most of the material that is already included in the existing textbooks. It pertains to the inverse vibration problem for inhomogeneous beam, i.e. the beam with the modulus of elasticity that varies along the axial coordinate. Specifically, the solution of the following problem is presented: Find a distribution of the modulus of elasticity of an inhomogeneous beam such that the beam would possess the preselected simple, polynomial vibration mode shape.
Nonlinear dynamics of pipeline with liquid in a vicinity of critical flow velocities
Authors: Limarchenko O. , Vasilevskiy Yu. 
Published: December 2014

We developed the nonlinear model of pipeline dynamics with high-speed liquid motion. On the basis of the variational methods we constructed the nonlinear discrete model and numerical algorithm for investigation of problems of dynamics and dynamical stability of pipeline. We considered examples of dynamical behavior of the system for different velocities of liquid flowing, including the case of critical velocity of flow, when loss of straight line stability of pipeline is possible.