scholarly journals Molecular modelling of human complement subcomponent C1q and its complex with C1r2C1s2 derived from neutron-scattering curves and hydrodynamic properties

1985 ◽  
Vol 228 (1) ◽  
pp. 13-26 ◽  
Author(s):  
S J Perkins
Keyword(s):  
Electron Microscopy ◽  
Neutron Scattering ◽  
Shape Change ◽  
Scattering Data ◽  
Human Complement ◽  
Primary Sequence ◽  
Hydrodynamic Properties ◽  
Hydrodynamic Calculations ◽  
The Mean ◽  
Large Shape

Models for the structures of subcomponent C1q of first component C1 of human complement and its complex with subunit C1r2C1s2 are compared with experimental neutron-scattering curves. The length of the C1q collagenous arm is closer to 14.5 nm than to 11.5 nm proposed from electron microscopy, and this is consistent with the primary sequence of C1q. The mean C1q base-arm angle is 40-45 degrees and C1q is found to be flexible: the base-arm angle can vary up to 30 degrees from equilibrium at any moment. The complex of C1r2C1s2 and C1q requires a large shape change in C1r2C1s2. Ring-like models for C1r2C1s2 are not as successful at rationalizing the scattering data as are models that involve C1r2C1s2 binding to one side of C1q. Hydrodynamic calculations of the sedimentation coefficients for C1q and C1 are generally consistent with these neutron models.

Autocorrelation function of the spin misalignment in magnetic small-angle neutron scattering: application to nanocrystalline metals

2013 ◽  
Vol 46 (3) ◽  
pp. 788-790 ◽  
Author(s):  
Andreas Michels ◽  
Jens-Peter Bick
Keyword(s):  
Neutron Scattering ◽  
Autocorrelation Function ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Anisotropy Field ◽  
Real Space ◽  
Scattering Data ◽  
Stiffness Constant ◽  
The Mean ◽  
Cobalt And Nickel

Real-space magnetic small-angle neutron scattering data from nanocrystalline cobalt and nickel have been analysed in terms of a recently developed micromagnetic theory for the autocorrelation function of the spin misalignment [Michels (2010).Phys. Rev. B,82, 024433]. The approach provides information on the exchange-stiffness constant and on the mean magnetic `anisotropy-field' radius.

Insight into the Formation of Ultrafine Nanostructures in Bulk Amorphous Zr54.5 Ti7.5Al10Cu20Ni8

2001 ◽  
Vol 703 ◽  
Author(s):  
André Heinemann ◽  
Helmut Hermann ◽  
Albrecht Wiedenmann ◽  
Norbert Mattern ◽  
Uta Kühn ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Volume Fraction ◽  
High Volume ◽  
High Resolution Electron Microscopy ◽  
Scattering Data ◽  
Scanning Calorimetry ◽  
Enhanced Diffusion ◽  
Resolution Electron ◽  
The Mean ◽  
Interparticle Interference

ABSTRACTBulk amorphous Zr54.5 Ti7.5Al10Cu20Ni8 is investigated by means of smal-angle neutron scattering (SANS), differential-scanning calorimetry (DSC), high-resolution electron microscopy (HREM) and other methods. The formation of ultrafine nanostructures in the glassy phase is observed and explained by a new model. Structura fluctuations of randomly distributed partialy ordered domains grow during annealing just below the glass transition temperature by local re-ordering. During anneaing the DSC gives evidence for a increasing volume fraction of the localy ordered domains. At high volume fractions of impinging domains a percolation threshold on the interconnected domain boundaries occurs and enhanced diffusion becomes possible. At that stage SANS measurements lead to satistically significant scattering data. The SANS signals are anayzed in terms of a model taking into account spherica particles surrounded by diffusion zones and interparticle interference effects. The mean radius of the nanocrystaline particles is determined to 1 nm and the mean thickness of the depletion zone is 2 nm. The upper limit for the volume fraction after annealing at 653 K for 4hours is about 20 %. Electron microscopy confirms the size and shows that the particle are crystaline.

scholarly journals VC-Precipitation Kinetics Studied by Small-Angle Neutron Scattering in Nano-Steels

2018 ◽  
Vol 941 ◽  
pp. 236-244 ◽  
Author(s):  
Chrysoula Ioannidou ◽  
Zaloa Arechabaleta ◽  
Arjan Rijkenberg ◽  
Robert M. Dalgliesh ◽  
A.A. van Well ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Neutron Scattering ◽  
Small Angle ◽  
Inductively Coupled Plasma ◽  
Small Angle Neutron Scattering ◽  
Volume Fraction ◽  
Optical Emission ◽  
Scattering Data ◽  
High Tech ◽  
Precipitation Kinetics

Nanosteels are used in automotive applications to accomplish resource-efficiency while providing high-tech properties. Quantitative data and further understanding on the precipitation kinetics in Nanosteels can contribute to fulfil this goal. Small-Angle Neutron Scattering measurements are performed on a Fe-C-Mn-V steel, previously heat-treated in a dilatometer at 650°C for several holding times from seconds to 10 hours. The evolution of the precipitate volume fraction, size distribution and number density is calculated by fitting the experimental Small-Angle Neutron Scattering curves. The effect of phase transformation on precipitation kinetics is also discussed. Complementary Transmission Electron Microscopy, Scanning Electron Microscopy and Inductively Coupled Plasma Optical Emission Spectroscopy measurements are performed to support the Small-Angle Neutron Scattering data analysis.

Ultrafine nanostructure of partially crystallized bulk amorphous Zr54.5Ti7.5Al10Cu20Ni8

2001 ◽  
Vol 34 (5) ◽  
pp. 666-668 ◽  
Author(s):  
Helmut Hermann ◽  
André Heinemann ◽  
Hans-Dietrich Bauer ◽  
Norbert Mattern ◽  
Uta Kühn ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Small Angle Neutron Scattering ◽  
Volume Fraction ◽  
High Resolution Electron Microscopy ◽  
Scattering Data ◽  
Depletion Zone ◽  
Upper Limit ◽  
Resolution Electron ◽  
The Mean ◽  
Interparticle Interference

Bulk amorphous Zr54.5Ti7.5Al10Cu20Ni8was investigated by means of small-angle neutron scattering and high-resolution electron microscopy. Partially crystallized states were generated by annealing. The scattering data were analyzed in terms of a model taking into account both properties of the particles and interparticle interference. The mean radius of the particles is 1.3 nm. They are surrounded by a depletion zone with mean thickness of 2.6 nm. The volume fraction of the particles is estimated from the interparticle interference effect; its upper limit after annealing at 653 K for 4 h is 12%. Electron microscopy confirms the size determined from the scattering data and shows that the particles are crystalline.

Long-period modulated superstructures in Pd-12.5 at.%Ce and Pd-15 at.%Ce alloys

1990 ◽  
Vol 48 (4) ◽  
pp. 164-165
Author(s):  
Noriyuki Kuwano ◽  
Masaru Itakura ◽  
Kensuke Oki
Keyword(s):  
Electron Microscopy ◽  
Mean Value ◽  
Heavy Elements ◽  
Arc Furnace ◽  
X Ray ◽  
Long Period ◽  
Ultra High Purity ◽  
Heat Treated ◽  
Atomic Scattering ◽  
The Mean

Pd-Ce alloys exhibit various anomalies in physical properties due to mixed valences of Ce, and the anomalies are thought to be strongly related with the crystal structures. Since Pd and Ce are both heavy elements, relative magnitudes of (fcc-fpd) are so small compared with <f> that superlattice reflections, even if any, sometimes cannot be detected in conventional x-ray powder patterns, where fee and fpd are atomic scattering factors of Ce and Pd, and <f> the mean value in the crystal. However, superlattices in Pd-Ce alloys can be analyzed by electron microscopy, thanks to the high detectability of electron diffraction. In this work, we investigated modulated superstructures in alloys with 12.5 and 15.0 at.%Ce.Ingots of Pd-Ce alloys were prepared in an arc furnace under atmosphere of ultra high purity argon. The disc specimens cut out from the ingots were heat-treated in vacuum and electrothinned to electron transparency by a jet method.

Microstructure of die-cast alloys Mg–Zn–Al(–Ca): a study by electron microscopy and small-angle neutron scattering

2003 ◽  
Vol 94 (5) ◽  
pp. 564-571 ◽  
Author(s):  
Michael Vogel ◽  
Oliver Kraft ◽  
Peter Staron ◽  
Helmut Clemens ◽  
Rainer Rauh ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Die Cast ◽  
Cast Alloys

scholarly journals The force effects of two types of polyethylene terephthalate glyc-olmodified clear aligners immersed in artificial saliva

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Biao Xiang ◽  
Xingxing Wang ◽  
Gang Wu ◽  
Yichen Xu ◽  
Menghan Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polyethylene Terephthalate ◽  
Artificial Saliva ◽  
Orthodontic Force ◽  
The Mean ◽  
The Stability ◽  
Scanning Electron

AbstractNumerous factors can influence the force exerted by clear aligners on teeth. This study aimed to investigate the stability of the force delivered by two different material appliances. 90 clear aligners with 2 materials and three different activations were designed and fabricated. Then, a device was employed to measure the force generated by the two types of PET-G material appliances immersed in artificial saliva for 0, 3, 7, 10, 14 days. Scanning electron microscopy was applied to observe the morphologic alterations on the aligner surfaces, respectively. The forces generated by different activation appliance exhibited differently, 0.0 mm < 0.1 mm < 0.2 mm. In addition, increasing the immersion times and the orthodontic force also decreased, but the forces decreased differently. Compared with the forces of conventional PETG appliances with 0.20 mm activation, the modified PETG appliances with the same activation exhibited significantly higher mean force. When comparing the mean force for modified PETG appliances after 10 and 14 days with conventional PETG appliances, the delivery forces exhibited significant differences (P < 0.05). The force delivered by both materials decreased obviously following artificial saliva immersion, and the force generated by modified aligners exhibited better stability than conventional aligners.

scholarly journals Electron Microscopy and Hydrodynamic Properties of Factor XIII Subunits

1989 ◽  
Vol 264 (1) ◽  
pp. 551-556
Author(s):  
N A Carrell ◽  
H P Erickson ◽  
J McDonagh
Keyword(s):  
Electron Microscopy ◽  
Factor Xiii ◽  
Hydrodynamic Properties
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