Theoretical studies on the conformation of saccharides. VIII. Solvent effect on the stability of β-cellobiose conformers

Biopolymers ◽  
1984 ◽  
Vol 23 (10) ◽  
pp. 1951-1960 ◽  
Author(s):  
Igor Tvaroška
Keyword(s):  
Solvent Effect ◽  
Theoretical Studies ◽  
The Stability

scholarly journals Structural Properties of G,T-Parallel Duplexes

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Anna Aviñó ◽  
Elena Cubero ◽  
Raimundo Gargallo ◽  
Carlos González ◽  
Modesto Orozco ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Structural Properties ◽  
Theoretical Calculations ◽  
Md Simulations ◽  
Theoretical Studies ◽  
Duplex Structure ◽  
Strong Stabilization ◽  
The Stability ◽  
The Impact

The structure of G,T-parallel-stranded duplexes of DNA carrying similar amounts of adenine and guanine residues is studied by means of molecular dynamics (MD) simulations and UV- and CD spectroscopies. In addition the impact of the substitution of adenine by 8-aminoadenine and guanine by 8-aminoguanine is analyzed. The presence of 8-aminoadenine and 8-aminoguanine stabilizes the parallel duplex structure. Binding of these oligonucleotides to their target polypyrimidine sequences to form the corresponding G,T-parallel triplex was not observed. Instead, when unmodified parallel-stranded duplexes were mixed with their polypyrimidine target, an interstrand Watson-Crick duplex was formed. As predicted by theoretical calculations parallel-stranded duplexes carrying 8-aminopurines did not bind to their target. The preference for the parallel-duplex over the Watson-Crick antiparallel duplex is attributed to the strong stabilization of the parallel duplex produced by the 8-aminopurines. Theoretical studies show that the isomorphism of the triads is crucial for the stability of the parallel triplex.

REVIEW ON THEORETICAL STUDIES OF SUPERHEAVY NUCLEI

2006 ◽  
Vol 15 (07) ◽  
pp. 1587-1599 ◽  
Author(s):  
ZHONGZHOU REN ◽  
DINGHAN CHEN ◽  
CHANG XU
Keyword(s):  
Ground State ◽  
Large Mass ◽  
Mass Region ◽  
Superheavy Nuclei ◽  
Theoretical Studies ◽  
Shape Coexistence ◽  
Good Test ◽  
Α Decay ◽  
The Stability ◽  
Theoretical Results

Superheavy elements have provided a good test of the validity of both nuclear structure models and nuclear decay models in a large mass region. We firstly review the recent progress on theoretical studies of superheavy nuclei. Emphasis is placed on the structure and decay of superheavy nuclei. Then theoretical results of odd-odd nuclei with Z = 109 - 115 are presented and discussed. It is clearly demonstrated that there is shape coexistence for the ground state of many superheavy nuclei from different models and many superheavy nuclei are deformed. In some cases superdeformation can become the ground state of superheavy nuclei and it is important for future studies of superheavy nuclei. This can lead to the existence of low-energy isomers in the superheavy region and it plays an important role for the stability of superheavy nuclei. As α-decay and spontaneous fission plays a crucial role for identifications of new elements, we also review some typical models of α-decay half-lives and spontaneous fissions half-lives. Some new views on superheavy nuclei are presented.

scholarly journals Traveling and standing waves mediate pattern formation in cellular protrusions

2020 ◽  
Vol 6 (32) ◽  
pp. eaay7682
Author(s):  
Sayak Bhattacharya ◽  
Tatsat Banerjee ◽  
Yuchuan Miao ◽  
Huiwang Zhan ◽  
Peter N. Devreotes ◽  
...  
Keyword(s):  
Pattern Formation ◽  
Traveling Waves ◽  
Standing Waves ◽  
Cell Cortex ◽  
Theoretical Studies ◽  
Direct Transformation ◽  
Diffusion Parameters ◽  
Excitable Systems ◽  
Mutant Strains ◽  
The Stability

The mechanisms regulating protrusions during amoeboid migration exhibit excitability. Theoretical studies have suggested the possible coexistence of traveling and standing waves in excitable systems. Here, we demonstrate the direct transformation of a traveling into a standing wave and establish conditions for the stability of this conversion. This theory combines excitable wave stopping and the emergence of a family of standing waves at zero velocity, without altering diffusion parameters. Experimentally, we show the existence of this phenomenon on the cell cortex of some Dictyostelium and mammalian mutant strains. We further predict a template that encompasses a spectrum of protrusive phenotypes, including pseudopodia and filopodia, through transitions between traveling and standing waves, allowing the cell to switch between excitability and bistability. Overall, this suggests that a previously-unidentified method of pattern formation, in which traveling waves spread, stop, and turn into standing waves that rearrange to form stable patterns, governs cell motility.

Synthesis and characterization of 1,3,5-triarylpyrazol-4-ols and 3,5-diarylisoxazol-4-ols from chalcones and theoretical studies of the stability of pyrazol-4-ol toward acid dehydration

2020 ◽  
Vol 1204 ◽  
pp. 127536
Author(s):  
Edna Carolina Cipagauta Esquivel ◽  
Virgínia Camila Rufino ◽  
Matheus Henrique Trindade Nogueira ◽  
Ana Carolina Carbonaro Souza ◽  
Josefredo Rodriguez Pliego Júnior ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Theoretical Studies ◽  
The Stability

Intrinsic Defects in GaAs - the Case of El2

1987 ◽  
Vol 104 ◽  
Author(s):  
H. J. Von Bardeleben ◽  
D. Stievemard
Keyword(s):  
Electronic Structure ◽  
Stable Configuration ◽  
Theoretical Studies ◽  
Absorption Bands ◽  
Teller Distortion ◽  
Jahn Teller ◽  
The Stability ◽  
Additional Support ◽  
Jahn Teller Distortion ◽  
Experimental And Theoretical Studies

ABSTRACTThe arsenic antisite-arsenic interstitial pair model for the stable configuration of the EL2 defect in GaAs has stimulated new experimental and theoretical studies, the results of which lead to additional support for this model. Recent theoretical studies, taking into account the effect of a Jahn Teller distortion of the T2 Asi levels have given an insight into the stability and the electronic structure of the defect pair. Further, ODENDOR studies have directly confirmed this model and allowed one to specify the lattice location and the charge state of the Asi ion. The pair structure of this defect implies a reconsideration of the charge states of the EL2 defect, as well as the origin of the optical absorption bands for which transitions on the Asi ion and intracenter bands have also to be considered. The model leads further to a description of the metastable configuration : an arsenic molecule at the gallium vacancy site, the electronic structure of which is calculated. The vacancy related defects, known from electron irradiation studies, are not detected in LEC grown GaAs as native defects.

scholarly journals A New Approach to Decoupled Non-Resonant Polishing

Micromachines ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 484
Author(s):  
Yucheng Li ◽  
Xiaoqin Zhou ◽  
Guilian Wang ◽  
Peiqun Ma ◽  
Rongqi Wang
Keyword(s):  
Theoretical Model ◽  
Vibration Frequency ◽  
Theoretical Studies ◽  
Workpiece Surface ◽  
New Approach ◽  
Structured Surfaces ◽  
Processing Demands ◽  
The Stability ◽  
Polishing Tool ◽  
Very High

Two-dimensional vibration-assisted polishing (2D-VAP) is a new polishing approach proposed in recent years, which is considered to be very suitable for the polishing of micro-optical parts and micro-structured surfaces. The advantages of the 2D-VAP approach are as follows: A very high relative velocity can be obtained between the workpiece and the polishing tool; the desired motion trajectory can be formed in one polishing cycle. However, there are still some problems to be solved in the 2D-VAP approach, mainly involving: The vibration frequency of the resonant excitation cannot be regulated, which makes it difficult to adapt to the processing demands of different materials; the theoretical model of removal function has been studied in few papers; and motion coupling occurs easily between the horizontal and vertical directions, which affects the trajectory synthesized at the polishing tool. In order to solve these problems, a new approach to decoupled non-resonant polishing is developed in this paper, and its effectiveness is investigated by the theoretical analysis and polishing experiments. Theoretical studies of removal function show that the vibration frequency, vibration amplitude and loading force are proportional to the removal depth. The comparison of experimental and modeling results of removal function show that they have good coherence, and the correctness of the theoretical model of removal function is verified. In addition, the stability experiments of removal function prove that the polishing approach has better stability and is beneficial to the convergence of workpiece surface.

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