Sökresultat
Filtrera
Filtyp
Din sökning på "*" gav 529860 sökträffar
Association of Napthalene-Labeled Poly(acrylic acid) and Interaction with Cationic Surfactants. Fluorescence Studies
Water-soluble poly(acrylic acid) has been covalently labeled with a fluorescent hydrophobic chromophore, naphthalene (Np), randomly attached onto the polymer backbone with an amount of 3 mol %. The polymer, which is a new type of hydrophobically modified polymer denoted PAAMeNp-34, was investigated using steady-state fluorescence spectroscopy in aqueous solutions of different pH and in methanol. T
Simulation of characteristics of a molecular single-electron tunneling transistor with a discrete energy spectrum of the central electrode
Current-voltage curves of molecular single-electron tunneling transistors are simulated based on a modified theory of single electronics that accounts for the discreteness of the energy spectrum of the molecule. The simulation was performed including effects of energy relaxation of the electrons in the molecule for two limiting cases of fast and slow relaxation, and for both equidistant and random
Tumour cell dissemination following endoscopic stent insertion
Core-level electron spectroscopy on the sodium dimer Na 2p level
The lifetime broadening and molecular field splitting of the sodium dimer 2p core level is studied by x-ray photoelectron spectroscopy and by Auger electron spectroscopy. The lifetime of the Na 2p core hole has been determined to be 15 +/- 8 fs, much shorter than what has previously been reported for solid sodium. The molecular field splitting of this core level has been determined to be 42 +/- 10
Effect of cooling on vascular smooth muscle response to endothelin-1 in human and rat veins
BACKGROUND: The plasma level of endothelin-1 is locally increased during cooling but the net vasoconstrictor effect will be dependent on temperature effects on the vascular smooth muscle reactivity in response to the polypeptide. The aim of this study was to investigate the effect of cooling on the vascular smooth muscle response to endothelin-1 in human and rat veins. METHODS: Registration of vas
Chromosomal aberration frequency in lymphocytes predicts the risk of cancer: results from a pooled cohort study of 22 358 subjects in 11 countries
Mechanistic evidence linking chromosomal aberration (CA) to early stages of cancer has been recently supported by the results of epidemiological studies that associated CA frequency in peripheral lymphocytes of healthy individuals to future cancer incidence. To overcome the limitations of single studies and to evaluate the strength of this association, a pooled analysis was carried out. The pooled
Can the LR test be helpful in choosing the optimal lag order in the VAR model when information criteria suggest different lag orders?
The objective of this simulation study is to investigate whether the likelihood ratio (LR) test can pick the optimal lag order in the vector autoregressive model when the most applied information criteria (i.e. vector Schwarz-Bayesian, SBC and vector Hannan-Quinn, HQC) suggest two different lag orders. This lag-choosing procedure has been suggested by Hatemi-J (1999). The results based on the Mont
A coupled carbon and water flux model to predict vegetation structure
A coupled carbon and water flux model (BIOME2) captures the broad-scale environmental controls on the natural distribution of vegetation structural and phenological types in Australia. Model input consists of latitude, soil type, and mean monthly climate (temperature, precipitation, and sunshine hours) data on a 1/10 degrees grid. Model output consists of foliage projective cover (FPC) for the qua
Glomerular permeability to macromolecules in the Necturus kidney
Tanner GA, Rippe C, Shao Y, Evan AP, Williams JC, Jr. Glomerular permeability to macromolecules in the Necturus kidney. Am J Physiol Renal Physiol 296: F1269-F1278, 2009. First published April 1, 2009; doi: 10.1152/ajprenal.00371.2007.-Many aspects of the glomerular filtration of macromolecules remain controversial, including the location of the major filtration barrier, the effects of electrical
Developing a competence-based core curriculum in biomedical laboratory science: a Delphi study.
In this study the Delphi technique has been used to develop a core curriculum for education of the biomedical scientist. The rapid development in biomedicine and the corresponding changes in methodology in biomedical laboratories demand careful planning of the education of biomedical scientists. The Delphi technique uses an anonymous panel of experts for suggestions and assessments aiming at conse
Questionnaire versus direct technical measurements in assessing postures and movements of the head, upper back, arms and hands
OBJECTIVES: This study compares questionnaire-assessed exposure data on work postures and movements with direct technical measurements. METHODS: Inclinometers and goniometers were used to make full workday measurements of 41 office workers and 41 cleaners, stratified for such factors as musculoskeletal complaints. The subjects answered a questionnaire on work postures of the head, back, and upper
Accelerating vector operations by utilizing reconfigurable coprocessor architectures
To enhance performance of digital signal processing tasks while keeping the flexibility of programmable solutions is a clear motivation for coprocessors implemented as reconfigurable hardware blocks. This paper investigates the applicability of such coprocessors targeting digital signal processing multi-media applications, initially in the field of speech and audio. A tightly coupled coprocessor a
The value of bronchoalveolar lavage in the diagnosis and prognosis of sarcoidosis
MHC-based patterns of social and extra-pair mate choice in the Seychelles warbler
The existence and nature of indirect genetic benefits to mate choice remain contentious. Major histocompatibility complex (MHC) genes, which play a vital role in determining pathogen resistance in vertebrates, may be the link between mate choice and the genetic inheritance of vigour in offspring. Studies have shown that MHC-dependent mate choice can occur in mammal and fish species, but little wor
Parameter selection methods for axisymmetric flame tomography through Tikhonov regularization
Deconvolution of optically collected axisymmetric flame data is equivalent to solving an ill-posed problem subject to severe error amplification. Tikhonov regularization has recently been shown to be well suited for stabilizing this deconvolution, although the success of this method hinges on choosing a suitable regularization parameter. Incorporating a parameter selection scheme transforms this t
Quantitative magnetization transfer by trains of radio frequency pulses in human brain: extension of a free evolution model to continuous-wave-like conditions
Structural effects of naturally occurring human blood group B galactosyltransferase mutations adjacent to the DXD motif
Human blood group A and B antigens are produced by two closely related glycosyltransferase enzymes. An N-acetylgalactosaminyltransferase (GTA) utilizes UDP-GalNAc to extend H antigen acceptors (Fuc alpha(1-2)Gal beta-OR) producing A antigens, whereas a galactosyltransferase (GTB) utilizes UDP-Gal as a donor to extend H structures producing B antigens. GTA and GTB have a characteristic (DVD213)-D-2
IL-1{beta} Induced Transcriptional Up-regulation of Bradykinin B1 and B2 Receptors in Murine Airways.
Hyperresponsiveness to bronchoconstrictor stimuli is a major pathophysiologic feature of asthma, but the molecular mechanisms behind this are not fully understood. The release of TNF-alpha and IL-1 beta during the inflammatory process is believed to play an important role in airway hyperresponsiveness. We have previously demonstrated, using a murine in vitro model of chronic airway inflammation, t
A numerical comparison of 2D resistivity imaging with 10 electrode arrays
Numerical simulations are used to compare the resolution and efficiency of 2D resistivity imaging surveys for 10 electrode arrays. The arrays analysed include pole-pole (PP), pole-dipole (PD), half-Wenner (HW), Wenner-alpha (WN), Schlumberger (SC), 'dipole-dipole (DD), Wenner-beta (WB), gamma-array (GM), multiple or moving gradient array (GD) and mid point-potential-referred measurement (MPR) arra