scholarly journals The affine and Euclidean normalizers of the subperiodic groups

2015 ◽  
Vol 71 (2) ◽  
pp. 150-160
Author(s):  
Brian Kevin VanLeeuwen ◽  
Pedro Valentín De Jesús ◽  
Daniel B. Litvin ◽  
Venkatraman Gopalan
Keyword(s):  
Plane Group ◽  
Layer Groups ◽  
Special Metrics

The affine and Euclidean normalizers of the subperiodic groups, the frieze groups, the rod groups and the layer groups, are derived and listed. For the layer groups, the special metrics used for plane-group Euclidean normalizers have been considered.

Artefact in 20Å-Resolution Electron Images of Negatively Stained Twodimensional Membrane Protein Crystals

1982 ◽  
Vol 40 ◽  
pp. 92-93
Author(s):  
Douglas L. Dorset ◽  
Barbara Moss
Keyword(s):  
Electron Scattering ◽  
Cross Correlation ◽  
Transmission Function ◽  
Group Symmetry ◽  
Asymmetric Structure ◽  
Object Model ◽  
Phase Object ◽  
Computing Systems ◽  
Resolution Electron ◽  
Plane Group

A number of computing systems devoted to the averaging of electron images of two-dimensional macromolecular crystalline arrays have facilitated the visualization of negatively-stained biological structures. Either by simulation of optical filtering techniques or, in more refined treatments, by cross-correlation averaging, an idealized representation of the repeating asymmetric structure unit is constructed, eliminating image distortions due to radiation damage, stain irregularities and, in the latter approach, imperfections and distortions in the unit cell repeat. In these analyses it is generally assumed that the electron scattering from the thin negativelystained object is well-approximated by a phase object model. Even when absorption effects are considered (i.e. “amplitude contrast“), the expansion of the transmission function, q(x,y)=exp (iσɸ (x,y)), does not exceed the first (kinematical) term. Furthermore, in reconstruction of electron images, kinematical phases are applied to diffraction amplitudes and obey the constraints of the plane group symmetry.

Study on Clinical Application of Different Ultrasound-Guided Planar Techniques in Minimally Invasive Percutaneous Nephrolithotomy

2021 ◽  
pp. 155335062199779
Author(s):  
Difu Fan ◽  
Leming Song ◽  
Monong Li ◽  
Chunxiang Luo ◽  
Xiaohui Liao ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Real Time ◽  
Clinical Application ◽  
Short Axis ◽  
Ultrasound Guided ◽  
Out Of Plane ◽  
Minimally Invasive Percutaneous Nephrolithotomy ◽  
Plane Group ◽  
Plane Technique ◽  
Guided Puncture

Objective. The objective is to explore the clinical application value of ultrasound long- and short-axis planar technology in real-time guided puncture in minimally invasive percutaneous nephrology. Methods. The clinical data of 80 patients undergoing real-time ultrasound-guided minimally invasive percutaneous nephrolithotomy from September 2018 to October 2019 were analyzed. The patients were randomly divided into 2 groups with different ultrasound-guided puncture techniques, long-axis in-plane technique and short-axis out-of-plane technique. Results. Minimally invasive percutaneous nephrolithotomies under real-time ultrasound guidance were successfully completed in both groups of patients. The success rate of the first puncture in the short-axis out-of-plane group was significantly higher than that in the long-axis in-plane group, and the differences were statistically significant ( P <.05); the total puncture time in the short-axis out-of-plane group was significantly less than the long-axis in-plane group, and the differences were statistical significance ( P <.05); there was no significant difference in the single-stage stone removal rate, total percutaneous renal channels, total hospital stay, and rate of complications by the Clavien classification between the 2 groups ( P > .05). Conclusion. Ultrasound long-axis and short-axis planar technologies can achieve good clinical application results in real-time guided puncture to establish percutaneous renal channels during minimally invasive percutaneous nephrolithotomy. Compared with the long-axis in-plane technique, the short-axis out-of-plane technique can shorten the puncture time and improve the success rate of the first puncture.

scholarly journals A formalism for the investigation of algebraically special metrics. I

1974 ◽  
Vol 37 (4) ◽  
pp. 311-326 ◽  
Author(s):  
A. Held
Keyword(s):  
Special Metrics

Q-reducible two-dimensional space groups and layer groups

1987 ◽  
Vol 20 (7) ◽  
pp. 1655-1659 ◽  
Author(s):  
D B Litvin ◽  
V Kopsky
Keyword(s):  
Dimensional Space ◽  
Two Dimensional ◽  
Space Groups ◽  
Layer Groups

scholarly journals Spin-orbit semimetals in the layer groups

2016 ◽  
Vol 94 (15) ◽  
Author(s):  
Benjamin J. Wieder ◽  
C. L. Kane
Keyword(s):  
Spin Orbit ◽  
Layer Groups

Antiferromagnetism-Induced Spin Splitting in Systems Described by Magnetic Layer Groups

2021 ◽  
Author(s):  
Sergei A. Egorov ◽  
Daniel B. Litvin ◽  
Robert A. Evarestov
Keyword(s):  
Magnetic Layer ◽  
Spin Splitting ◽  
Layer Groups

GROWTH LAYER GROUPS (GLGs) IN THE TEETH OF AN ADULT BELUKHA WHALE (DELPHINAPTERUS LEUCAS) OF KNOWN AGE: EVIDENCE FOR TWO ANNUAL LAYERS

1987 ◽  
Vol 3 (1) ◽  
pp. 14-21 ◽  
Author(s):  
Arthur D. Goren ◽  
Paul F. Brodie ◽  
Stephen Spotte ◽  
G. Carleton Ray ◽  
H. W. Kaufman ◽  
...  
Keyword(s):  
Delphinapterus Leucas ◽  
Growth Layer ◽  
Layer Groups

The Eighty Layer Groups

1991 ◽  
pp. 18-26
Author(s):  
Daniel B. Litvin ◽  
Thomas R. Wike
Keyword(s):  
Layer Groups

scholarly journals First-Principles Predictions of Out-of-Plane Group IV and V Dimers as High-Symmetry, High-Spin Defects in Hexagonal Boron Nitride

2021 ◽  
Author(s):  
Jooyong Bhang ◽  
He Ma ◽  
Donggyu Yim ◽  
Giulia Galli ◽  
Hosung Seo
Keyword(s):  
Boron Nitride ◽  
High Spin ◽  
First Principles ◽  
Hexagonal Boron Nitride ◽  
Group Iv ◽  
High Symmetry ◽  
Out Of Plane ◽  
Plane Group

scholarly journals The site-symmetry induced representations of layer groups on the Bilbao Crystallographic Server

2019 ◽  
Vol 52 (5) ◽  
pp. 1214-1221 ◽  
Author(s):  
Gemma de la Flor ◽  
Danel Orobengoa ◽  
Robert A. Evarestov ◽  
Yuri E. Kitaev ◽  
Emre Tasci ◽  
...  
Keyword(s):  
Van Der Waals ◽  
Site Symmetry ◽  
Induced Representations ◽  
Symmetry Approach ◽  
Layered Crystals ◽  
Symmetry Relations ◽  
Layer Groups

The section of the Bilbao Crystallographic Server (http://www.cryst.ehu.es) dedicated to subperiodic groups includes a new tool called LSITESYM for the study of materials with layer and multilayer symmetry. This new program, based on the site-symmetry approach, establishes the symmetry relations between localized and extended crystal states using representations of layer groups. The efficiency and utility of the program LSITESYM is demonstrated by illustrative examples, which include the analysis of phonon symmetry in Aurivillius compounds and in van der Waals layered crystals MoS2 and WS2.

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