scholarly journals Characterization of the Asymmetry of the Cardiac and Sympathetic Arms of the Baroreflex From Spontaneous Variability During Incremental Head-Up Tilt

2019 ◽  
Vol 10 ◽  
Author(s):  
Beatrice De Maria ◽  
Vlasta Bari ◽  
Beatrice Cairo ◽  
Emanuele Vaini ◽  
Murray Esler ◽  
...  
Keyword(s):  
Head Up Tilt ◽  
The Asymmetry

Characterization of the cardiovascular control during modified head-up tilt test in healthy adult humans

2013 ◽  
Vol 179 (1-2) ◽  
pp. 166-169 ◽  
Author(s):  
Andrea Marchi ◽  
Riccardo Colombo ◽  
Stefano Guzzetti ◽  
Vlasta Bari ◽  
Tito Bassani ◽  
...  
Keyword(s):  
Healthy Adult ◽  
Cardiovascular Control ◽  
Tilt Test ◽  
Adult Humans ◽  
Head Up Tilt ◽  
Head Up Tilt Test

Information Transfer through the Spontaneous Baroreflex in Healthy Humans

2010 ◽  
Vol 49 (05) ◽  
pp. 506-510 ◽  
Author(s):  
A. M. Catai ◽  
A. C. M. Takahashi ◽  
V. Magagnin ◽  
T. Bassani ◽  
E. Tobaldini ◽  
...  
Keyword(s):  
Arterial Pressure ◽  
Information Transfer ◽  
Function Analysis ◽  
Systolic Arterial Pressure ◽  
Heart Period ◽  
Uniform Quantization ◽  
Transfer Function Analysis ◽  
Head Up Tilt ◽  
Spontaneous Baroreflex

Summary Objectives: This study assesses the information transfer through the spontaneous baroreflex (i.e. through the pathway linking systolic arterial pressure to heart period) during an experimental condition soliciting baroreflex (i.e. head-up tilt). Methods: The information transfer was calculated as the conditional entropy of heart period given systolic arterial pressure using a mutual neighbor approach and uniform quantization. The information transfer was monitored as a function of the forecasting time k. Results: We found that during head-up tilt the information transfer at k = 0 decreased but the rate of rise of information transfer as a function of k was faster. Conclusions: We suggest that the characterization of the information transfer from systolic arterial pressure to heart period might complement the traditional characterization of the spontaneous baroreflex based on transfer function analysis.

scholarly journals Simultaneous Characterization of Sympathetic and Cardiac Arms of the Baroreflex through Sequence Techniques during Incremental Head-Up Tilt

2016 ◽  
Vol 7 ◽  
Author(s):  
Andrea Marchi ◽  
Vlasta Bari ◽  
Beatrice De Maria ◽  
Murray Esler ◽  
Elisabeth Lambert ◽  
...  
Keyword(s):  
Head Up Tilt ◽  
Sequence Techniques

Experimental Characterization Of The Asymmetry And The Dip Form Of The H[sub β]-Line Profiles In Microwave-Produced Plasmas At Atmospheric Pressure

2008 ◽  
Author(s):  
J. M. Palomares ◽  
J. Torres ◽  
M. A. Gigosos ◽  
J. J. A. M. van der Mullen ◽  
A. Gamero ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Line Profiles ◽  
Experimental Characterization ◽  
The Asymmetry

scholarly journals Characterization of HIV-2 Protease Structure by Studying Its Asymmetry at the Different Levels of Protein Description

Symmetry ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 644 ◽  
Author(s):  
Guillaume Ollitrault ◽  
Sandrine Fartek ◽  
Diane Descamps ◽  
Anne-Claude Camproux ◽  
Benoît Visseaux ◽  
...  
Keyword(s):  
Ligand Binding ◽  
In Silico ◽  
Intrinsic Property ◽  
Structural Asymmetry ◽  
Important Target ◽  
Structural Deformations ◽  
The Asymmetry ◽  
Different Levels

HIV-2 protease (PR2) is a homodimer, which is an important target in the treatment of the HIV-2 infection. In this study, we developed an in silico protocol to analyze and characterize the asymmetry of the unbound PR2 structure using three levels of protein description by comparing the conformation, accessibility, and flexibility of each residue in the two PR2 chains. Our results showed that 65% of PR2 residues have at least one of the three studied asymmetries (structural, accessibility, or flexibility) with 10 positions presenting the three asymmetries in the same time. In addition, we noted that structural and flexibility asymmetries are linked indicating that the structural asymmetry of some positions result from their large flexibility. By comparing the structural asymmetry of the crystallographic and energetically minimized structures of the unbound PR2, we confirmed that the structural asymmetry of unbound PR2 is an intrinsic property of this protein with an important role for the PR2 deformation upon ligand binding. This analysis also allowed locating asymmetries corresponding to crystallization artefacts. This study provides insight that will help to better understand the structural deformations of PR2 and to identify key positions for ligand binding.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

Characterization of Coherent, Ordered Precipitates in Nickel-Base Alloys

1973 ◽  
Vol 31 ◽  
pp. 144-145
Author(s):  
B. H. Kear ◽  
J. M. Oblak
Keyword(s):  
Stable Phase ◽  
Nickel Base Superalloy ◽  
Alloy 718 ◽  
Commercial Alloy ◽  
Precipitate Morphology ◽  
Continuous Precipitation ◽  
Nickel Base ◽  
Base Superalloy ◽  
Strengthening Precipitate

A nickel-base superalloy is essentially a Ni/Cr solid solution hardened by additions of Al (Ti, Nb, etc.) to precipitate a coherent, ordered phase. In most commercial alloy systems, e.g. B-1900, IN-100 and Mar-M200, the stable precipitate is Ni3 (Al,Ti) γ′, with an LI2structure. In A lloy 901 the normal precipitate is metastable Nis Ti3 γ′ ; the stable phase is a hexagonal Do2 4 structure. In Alloy 718 the strengthening precipitate is metastable γ″, which has a body-centered tetragonal D022 structure.Precipitate MorphologyIn most systems the ordered γ′ phase forms by a continuous precipitation re-action, which gives rise to a uniform intragranular dispersion of precipitate particles. For zero γ/γ′ misfit, the γ′ precipitates assume a spheroidal.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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