scholarly journals Crystal twinning of bicontinuous cubic structures

IUCrJ ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 228-237 ◽  
Author(s):  
Lu Han ◽  
Nobuhisa Fujita ◽  
Hao Chen ◽  
Chenyu Jin ◽  
Osamu Terasaki ◽  
...  
Keyword(s):  
Differential Geometry ◽  
Mesoporous Silica ◽  
Numerical Modelling ◽  
Structure Formation ◽  
Twin Boundary ◽  
Soft Matter ◽  
Early Stage ◽  
Bicontinuous Cubic ◽  
Crystal Twinning ◽  
Silica Crystals

Bicontinuous cubic structures in soft matter consist of two intertwining labyrinths separated by a partitioning layer. Combining experiments, numerical modelling and techniques in differential geometry, we investigate twinning defects in bicontinuous cubic structures. We first demonstrate that a twin boundary is most likely to occur at a plane that cuts the partitioning layer almost perpendicularly, so that the perturbation caused by twinning remains minimal. This principle can be used as a criterion to identify potential twin boundaries, as demonstrated through detailed investigations of mesoporous silica crystals characterized by diamond and gyroid surfaces. We then discuss that a twin boundary can result from a stacking fault in the arrangement of inter-lamellar attachments at an early stage of structure formation. It is further shown that enhanced curvature fluctuations near the twin boundary would cost energy because of geometrical frustration, which would be eased by a crystal distortion that is experimentally observed.

scholarly journals Facile Synthesis of Large-Pore Bicontinuous Cubic Mesoporous Silica Nanoparticles for Intracellular Gene Delivery

ChemNanoMat ◽  
2016 ◽  
Vol 2 (3) ◽  
pp. 220-225 ◽  
Author(s):  
Anand Kumar Meka ◽  
Yuting Niu ◽  
Surajit Karmakar ◽  
Sandy Budi Hartono ◽  
Jun Zhang ◽  
...  
Keyword(s):  
Gene Delivery ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Facile Synthesis ◽  
Large Pore ◽  
Bicontinuous Cubic ◽  
Cubic Mesoporous

scholarly journals Neutrophil Extracellular Traps and Microcrystals

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Balázs Rada
Keyword(s):  
Early Stage ◽  
Neutrophil Extracellular Traps ◽  
Calcium Pyrophosphate ◽  
Cholesterol Crystals ◽  
Extracellular Traps ◽  
Calcium Pyrophosphate Dehydrate ◽  
Innate Immune Mechanism ◽  
Silica Crystals ◽  
Net Release ◽  
Urate Crystals

Neutrophil extracellular traps represent a fascinating mechanism by which PMNs entrap extracellular microbes. The primary purpose of this innate immune mechanism is thought to localize the infection at an early stage. Interestingly, the ability of different microcrystals to induce NET formation has been recently described. Microcrystals are insoluble crystals with a size of 1–100 micrometers that have different composition and shape. Microcrystals have it in common that they irritate phagocytes including PMNs and typically trigger an inflammatory response. This review is the first to summarize observations with regard to PMN activation and NET release induced by microcrystals. Gout-causing monosodium urate crystals, pseudogout-causing calcium pyrophosphate dehydrate crystals, cholesterol crystals associated with atherosclerosis, silicosis-causing silica crystals, and adjuvant alum crystals are discussed.

scholarly journals Structure Formation in Soft-Matter Solutions Induced by Solvent Evaporation

2017 ◽  
Vol 29 (45) ◽  
pp. 1703769 ◽  
Author(s):  
Jiajia Zhou ◽  
Xingkun Man ◽  
Ying Jiang ◽  
Masao Doi
Keyword(s):  
Structure Formation ◽  
Soft Matter ◽  
Solvent Evaporation

scholarly journals Kinetic Influence of Siliceous Reactions on Structure Formation of Mesoporous Silica Formed via the Co-Structure Directing Agent Route

2016 ◽  
Vol 120 (7) ◽  
pp. 3814-3821 ◽  
Author(s):  
Ruiyu Lin ◽  
Göran Carlström ◽  
Quoc Dat Pham ◽  
Michael W. Anderson ◽  
Daniel Topgaard ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Structure Formation ◽  
Structure Directing Agent

scholarly journals Structure formation peculiarities at early stage of Antarctic–Australia separation based on physical modeling

2019 ◽  
pp. 76-91
Author(s):  
E. P. Dubinin ◽  
G. L. Leichenkov ◽  
A. L. Grokholsky ◽  
V. M. Sergeeva ◽  
G. D. Agranov
Keyword(s):  
Surface Morphology ◽  
Structure Formation ◽  
Physical Modeling ◽  
Early Stage ◽  
Early Period ◽  
High Amplitude ◽  
Seismic Profiles ◽  
Natural Conditions ◽  
Propagating Rift ◽  
Breakup Model

The paper addresses crustal formation in the Australian–Antarctic basin at the early period of separation of Australia and Antarctica. The study covers long rifting (~160–80 Ma), ultraslow spreading (~80–45 Ma) with the formation of proto-oceanic, mainly ultrabasic crust, spreading (~45-40 Ma), and stationary spreading at medium velocities (after 40 Ma). The different stages of oceanic opening are clearly expressed in the changes of basement morphology (the top of the second oceanic layer) on seismic profiles. Physical modeling is used to reveal the peculiarities in the surface morphology of the oceanic (magmatic) crust which developed in the transitional conditions from ultraslow to slow and medium spreading. Our experiments established that (1) the presence of a stronger block in the pre-breakup model lithosphere in the pathway of the propagating rift faults can significantly affect the geometry of the spreading axis in its vicinity and lead to the development of transversal structures and a highly rugged relief; (2) under the conditions of ultraslow ocean accretion, numerous jumps of the spreading axes occur; (3) the temporary cessation of spreading leads to the development of linear high-amplitude uplifts corresponding to amagmatic ridges in the natural conditions.

Synthesis of SBA-16 and SBA-15 mesoporous silica crystals templated with neutral block copolymer surfactants

2008 ◽  
Vol 69 (2-3) ◽  
pp. 415-419 ◽  
Author(s):  
Chun-Ling Lin ◽  
Yi-Shung Pang ◽  
Mann-Chien Chao ◽  
Bi-Chung Chen ◽  
Hong-Ping Lin ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Mesoporous Silica ◽  
Silica Crystals

Modeling and Simulation of Soft Contact and Adhesion of Stem Cells

2010 ◽  
Vol 1274 ◽  
Author(s):  
Shaofan Li ◽  
Xiaowei Zeng
Keyword(s):  
Stem Cells ◽  
Liquid Crystal ◽  
Modeling And Simulation ◽  
Focal Adhesion ◽  
Soft Matter ◽  
Cell Model ◽  
Early Stage ◽  
Constitutive Relations ◽  
Receptor Interaction ◽  
Cell Contact

AbstractIn this paper, we briefly report our recent work on multiscale modeling and simulations of soft elasticity and focal adhesion of stem cells. In particular, our work is focused on modeling and simulation of contact and adhesion of stem cells on substrates with different rigidities. In order to understand the precise mechanical influences on cell contact/adhesion and to explain the possible mechanotransduction mechanism, we have developed a three-dimensional soft-matter cell model that uses liquid-crystal gel or liquid-crystal elastomer gel to model the overall constitutive relations of the cell, and we have simulated the responses of the cell to extra-cellular stimulus. The discussion here is specifically focused on the following issues: (1) how to model the overall myosin responses at the early stage of differentiation process of the stem cell, (2) the effects of both the adhesive force due to ligand-receptor interaction or focal adhesion and the surface tension, and (3) possible cell conformation and configuration changes triggered by substrate's rigidity.

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