BMP-2-Immobilized Porous Matrix with Leaf-Stacked Structure as a Bioactive GBR Membrane

2018 ◽  
Vol 10 (36) ◽  
pp. 30115-30124 ◽  
Author(s):  
Ho Yong Kim ◽  
Jin Hyun Park ◽  
June-Ho Byun ◽  
Jin Ho Lee ◽  
Se Heang Oh
Keyword(s):  
Porous Matrix ◽  
Gbr Membrane

Outbursts of comet Schwassmann-Wachmann 1, and the cloud of interplanetary boulders

1974 ◽  
Vol 22 ◽  
pp. 307 ◽  
Author(s):  
Zdenek Sekanina
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Interplanetary Space ◽  
Porous Matrix ◽  
Maximum Diameter ◽  
Expansion Velocity ◽  
Solid Constituent ◽  
Meteoric Material ◽  
Periodic Comet

AbstractIt is suggested that the outbursts of Periodic Comet Schwassmann-Wachmann 1 are triggered by impacts of interplanetary boulders on the surface of the comet’s nucleus. The existence of a cloud of such boulders in interplanetary space was predicted by Harwit (1967). We have used the hypothesis to calculate the characteristics of the outbursts – such as their mean rate, optically important dimensions of ejected debris, expansion velocity of the ejecta, maximum diameter of the expanding cloud before it fades out, and the magnitude of the accompanying orbital impulse – and found them reasonably consistent with observations, if the solid constituent of the comet is assumed in the form of a porous matrix of lowstrength meteoric material. A Monte Carlo method was applied to simulate the distributions of impacts, their directions and impact velocities.

The Radiation Peculiarities of Nanoscale SnO2 in a Porous Matrix

2020 ◽  
Vol 12 (3) ◽  
pp. 03020-1-03020-4
Author(s):  
S. A. Gevelyuk ◽  
◽  
V. S. Grinevich ◽  
I. K. Doycho ◽  
Y. I. Lepikh ◽  
...  
Keyword(s):  
Porous Matrix

scholarly journals Wetting front dynamics in an isotropic porous medium

2012 ◽  
Vol 694 ◽  
pp. 399-407 ◽  
Author(s):  
Yulii D. Shikhmurzaev ◽  
James E. Sprittles
Keyword(s):  
Porous Medium ◽  
Incompressible Liquid ◽  
Porous Matrix ◽  
Viscous Incompressible Liquid ◽  
Pore Scale ◽  
Wetting Front ◽  
Model Case ◽  
New Approach ◽  
Threshold Phenomena ◽  
Front Dynamics

AbstractA new approach to the modelling of wetting fronts in porous media on the Darcy scale is developed, based on considering the types (modes) of motion the menisci go through on the pore scale. This approach is illustrated using a simple model case of imbibition of a viscous incompressible liquid into an isotropic porous matrix with two modes of motion for the menisci, the wetting mode and the threshold mode. The latter makes it necessary to introduce an essentially new technique of conjugate problems that allows one to link threshold phenomena on the pore scale with the motion on the Darcy scale. The developed approach (a) makes room for incorporating the actual physics of wetting on the pore scale, (b) brings in the physics associated with pore-scale thresholds, which determine when sections of the wetting front will be brought to a halt (pinned), and, importantly, (c) provides a regular framework for constructing models of increasing complexity.

scholarly journals Development of FGF-2-loaded electrospun waterborne polyurethane fibrous membranes for bone regeneration

2020 ◽  
Author(s):  
Chi Zhang ◽  
Jianxiong Wang ◽  
Yujie Xie ◽  
Li Wang ◽  
Lishi Yang ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Periodontal Regeneration ◽  
Waterborne Polyurethane ◽  
Related Factors ◽  
Positive Meaning ◽  
Chain Extenders ◽  
Biomimetic Membrane ◽  
Fibrous Membranes ◽  
Green Chemical Synthesis ◽  
Gbr Membrane

Abstract Guided bone regeneration (GBR) membrane has been used to improve functional outcomes for periodontal regeneration. However, few studies have focused on the biomimetic membrane mimicking the vascularization of the periodontal membrane. This study aimed to fabricate waterborne polyurethane (WPU) fibrous membranes loaded fibroblast growth factor-2 (FGF-2) via emulsion electrospinning, which can promote regeneration of periodontal tissue via the vascularization of the biomimetic GBR membrane. A biodegradable WPU was synthesized by using lysine and dimethylpropionic acid as chain extenders according to the rule of green chemical synthesis technology. The WPU fibers with FGF-2 was fabricated via emulsion electrospinning. The results confirmed that controlled properties of the fibrous membrane had been achieved with controlled degradation, suitable mechanical properties and sustained release of the factor. The immunohistochemical expression of angiogenic-related factors was positive, meaning that FGF-2 loaded in fibers can significantly promote cell vascularization. The fiber scaffold loaded FGF-2 has the potential to be used as a functional GBR membrane to promote the formation of extraosseous blood vessels during periodontal repairing.

scholarly journals Survey Summary on Salts Hydrates and Composites Used in Thermochemical Sorption Heat Storage: A Review

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3105
Author(s):  
Mohamed Zbair ◽  
Simona Bennici
Keyword(s):  
Composite Materials ◽  
Energy Density ◽  
Low Temperature ◽  
Mass Transport ◽  
Lower Energy ◽  
Heat Storage ◽  
Porous Matrix ◽  
Salt Hydrates ◽  
Sorption Heat ◽  
The Stability

To improve the proficiency of energy systems in addition to increasing the usage of renewable energies, thermal energy storage (TES) is a strategic path. The present literature review reports an overview of the recent advancements in the utilization of salt hydrates (single or binary mixtures) and composites as sorbents for sorption heat storage. Starting by introducing various heat storage systems, the operating concept of the adsorption TES was clarified and contrasted to other technologies. Consequently, a deep examination and crucial problems related to the different types of salt hydrates and adsorbents were performed. Recent advances in the composite materials used in sorption heat storage were also reviewed and compared. A deep discussion related to safety, price, availability, and hydrothermal stability issues is reported. Salt hydrates display high theoretical energy densities, which are promising materials in TES. However, they show a number of drawbacks for use in the basic state including low temperature overhydration and deliquescence (e.g., MgCl2), high temperature degradation, sluggish kinetics leading to a low temperature rise (e.g., MgSO4), corrosiveness and toxicity (e.g., Na2S), and low mass transport due to the material macrostructure. The biggest advantage of adsorption materials is that they are more hydrothermally stable. However, since adsorption is the most common sorption phenomenon, such materials have a lower energy content. Furthermore, when compared to salt hydrates, they have higher prices per mass, which reduces their appeal even further when combined with lower energy densities. Economies of scale and the optimization of manufacturing processes may help cut costs. Among the zeolites, Zeolite 13X is among the most promising. Temperature lifts of 35–45 °C were reached in lab-scale reactors and micro-scale experiments under the device operating settings. Although the key disadvantage is an excessively high desorption temperature, which is problematic to attain using heat sources, for instance, solar thermal collectors. To increase the energy densities and enhance the stability of adsorbents, composite materials have been examined to ameliorate the stability and to achieve suitable energy densities. Based on the reviewed materials, MgSO4 has been identified as the most promising salt; it presents a higher energy density compared to other salts and can be impregnated in a porous matrix to prepare composites in order to overcome the drawbacks connected to its use as pure salt. However, due to pore volume reduction, potential deliquescence and salt leakage from the composite as well as degradation, issues with heat and mass transport can still exist. In addition, to increase the kinetics, stability, and energy density, the use of binary salt deposited in a porous matrix is suitable. Nevertheless, this solution should take into account the deliquescence, safety, and cost of the selected salts. Therefore, binary systems can be the solution to design innovative materials with predetermined sorption properties adapted to particular sorption heat storage cycles. Finally, working condition, desorption temperature, material costs, lifetime, and reparation, among others, are the essential point for commercial competitiveness. High material costs and desorption temperatures, combined with lower energy densities under normal device operating conditions, decrease their market attractiveness. As a result, the introduction of performance metrics within the scientific community and the use of economic features on a material scale are suggested.

Diverse anion exchange of pliable [X2@Pd3L4]4+ double cages: a molecular ruler for recognition of polyatomic anions

2020 ◽  
Vol 49 (19) ◽  
pp. 6183-6190 ◽  
Author(s):  
Ganguri Sarada ◽  
Ahreum Kim ◽  
Dongwon Kim ◽  
Ok-Sang Jung
Keyword(s):  
Anion Exchange ◽  
Porous Matrix ◽  
Molecular Ruler

This pliable double cage is an efficient, tolerant, and reproducible porous matrix for diverse anion exchange, which is as a ruler for recognition of ubiquitous polyatomic anions.

Antibacterial Properties of Guided Bone Regeneration Membrane for Periodontal Applications

2014 ◽  
Vol 606 ◽  
pp. 47-50
Author(s):  
Nur Najiha Saarani ◽  
K. Jamuna-Thevi ◽  
Ida Idayu Muhammad ◽  
Hendra Hermawan
Keyword(s):  
Staphylococcus Aureus ◽  
Bone Regeneration ◽  
Composite Membrane ◽  
Lauric Acid ◽  
Antibacterial Properties ◽  
Guided Bone Regeneration ◽  
Significant Inhibition ◽  
Thermally Induced ◽  
Zones Of Inhibition ◽  
Gbr Membrane

Guided Bone Regeneration (GBR) membrane is used as a barrier to prevent soft tissue ingrowth and to encourage bone regeneration through cellular exclusion. This study aims to assess antibacterial properties of recently developed three-layered poly(lactic-co-glycolic acid) (PLGA) /lauric acid (LA) composite membrane towards Staphylococcus aureus. One of the outmost layers of three-layered membrane was incorporated with 1-3 wt% of LA. The composite membrane was developed using thermally induced phase separation/solvent leaching technique. SEM results shows formation of PLGA matrix with smaller pores by the addition of 1 wt% LA compared with pure PLGA membrane. Samples of 1.7 cm diameter disk containing 1, 2 and 3 wt% of lauric acid were tested and pure membrane without lauric acid was used as a control. Results showed that the zones of inhibition were 2.3 cm and 2.5 cm for the 2 wt% and 3 wt% LA-containing membranes, respectively. However, 1 wt% LA-containing membrane observed to have no inhibition at all, indicating that increasing concentration of LA has significant inhibition against Staphylococcus aureus. The 3 wt% LA composition will be used in the mechanically optimized membranes for degradation studies in future works.

The Dynamics of Chiral 5*CB Molecules Confined in a Porous Matrix

2014 ◽  
Vol 592 (1) ◽  
pp. 106-114 ◽  
Author(s):  
A. Bąk ◽  
K. Chłędowska ◽  
W. Szaj
Keyword(s):  
Porous Matrix
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