scholarly journals Computational study of bacterial depolymerization process of xenobiotic polymer

2018 ◽  
Vol 189 ◽  
pp. 02007
Author(s):  
Masaji Watanabe ◽  
Fusako Kawai
Keyword(s):  
Sole Carbon Source ◽  
Culture Media ◽  
Computational Study ◽  
Time Factor ◽  
Computational Techniques ◽  
Weight Distributions ◽  
Molecular Factor ◽  
Before And After ◽  
Parameter Values ◽  
Two Parameter

This study shows an efficient applicability of computational techniques to analyses of microbial depolymerisation process. Microorganisms were cultivated in a culture media in which a polymer was a sole carbon source, and weight distributions before and after cultivation were introduced into inverse analysis for a molecular factor and a time factor of a degradation rate. An inverse problem for two parameter values associated with the time factor was solved numerically. Once the molecular factor and the time factor were given, microbial depolymerization process was simulated.

Structural integrity after cold storage of human epidermal model in hypothermosol: A correlative ultrastructural and fluorescent assay

1994 ◽  
Vol 52 ◽  
pp. 270-271
Author(s):  
Henry H. Eichelberger ◽  
John G. Baust ◽  
Robert G. Van Buskirk
Keyword(s):  
Cold Storage ◽  
Structural Integrity ◽  
Culture Media ◽  
Cell Structure ◽  
Natural State ◽  
Sodium Cacodylate ◽  
Ruthenium Tetroxide ◽  
Cacodylate Buffer ◽  
Before And After

For research in cell differentiation and in vitro toxicology it is essential to provide a natural state of cell structure as a benchmark for interpreting results. Hypothermosol (Cryomedical Sciences, Rockville, MD) has proven useful in insuring the viability of synthetic human epidermis during cold-storage and in maintaining the epidermis’ ability to continue to differentiate following warming.Human epidermal equivalent, EpiDerm (MatTek Corporation, Ashland, MA) consisting of fully differentiated stratified human epidermal cells were grown on a microporous membrane. EpiDerm samples were fixed before and after cold-storage (4°C) for 5 days in Hypothermosol or skin culture media (MatTek Corporation) and allowed to recover for 7 days at 37°C. EpiDerm samples were fixed 1 hour in 2.5% glutaraldehyde in sodium cacodylate buffer (pH 7.2). A secondary fixation with 0.2% ruthenium tetroxide (Polysciences, Inc., Warrington, PA) in sodium cacodylate was carried out for 3 hours at 4°C. Other samples were similarly fixed, but with 1% Osmium tetroxide in place of ruthenium tetroxide. Samples were dehydrated through a graded acetone series, infiltrated with Spurrs resin (Polysciences Inc.) and polymerized at 70°C.

Cytocompatibility of Magnesium-Zinc-Calcium Alloys with Bone Marrow Derived Mesenchymal Stem Cells

2014 ◽  
Vol 922 ◽  
pp. 1-6
Author(s):  
Aaron F. Cipriano ◽  
Christopher Miller ◽  
Hui Nan Liu
Keyword(s):  
Biomedical Applications ◽  
Culture Media ◽  
Corrosion Properties ◽  
Cell Culture Media ◽  
Tissue Culture Polystyrene ◽  
Metallic Biomaterials ◽  
Zn Content ◽  
Before And After ◽  
Orthopedic Applications ◽  
Early Indication

Magnesium (Mg)-based alloys have attracted great interest as metallic biomaterials for orthopedic applications due to their biocompatibility, biodegradability, and mechanical properties that resemble those of cortical bone. However, the potential toxicity of alloying elements in commercially available Mg alloys makes it critical to engineer and screen new alloys specifically for biomedical applications. The objective of this study was to evaluate and compare the in vitrodegradation and cytocompatibility of two distinct Mg - Zinc (Zn) - Calcium (Ca) alloys (Mg-4%Zn-1%Ca and Mg-9%Zn-1%Ca, wt. %; abbreviated as ZCa41 and ZCa91, respectively) using a bonemarrow derived mesenchymal stem cell (BMSC) model. Both Zn and Ca play critical roles in boneformation and growth, and have been shown to increase mechanical and corrosion properties of Mgalloys. BMSCs provide vertebrates the continuous supply of osteoblasts needed for bone remodelingand repair, and thus were selected to determine the effect of increasing Zn content on cell behavior.Surface microstructure and composition of the alloys were characterized before and after BMSC culture using field emission scanning electron microscopy (FESEM) and energy dispersive X-rayspectroscopy (EDS). Thermanox® treated glass and plasma treated tissue culture polystyrene were used as a control and reference, respectively. Results indicated that the ZCa91 alloy improved BMSC adhesion as compared with ZCa41 alloy. The formation of high-aspect ratio needle-likefeatures on the surface of ZCa41 alloy after its degradation in cell culture media was speculated tocontribute to the lower cell adhesion. This study provided an early indication on cytocompatibility of Mg-Zn-Ca alloys for biomedical applications.

scholarly journals A High Throughput Approach Based on Dynamic High Pressure for the Encapsulation of Active Compounds in Exosomes for Precision Medicine

2021 ◽  
Vol 22 (18) ◽  
pp. 9896
Author(s):  
Eugenia Romano ◽  
Paolo Antonio Netti ◽  
Enza Torino
Keyword(s):  
Cell Culture ◽  
High Pressure ◽  
Culture Media ◽  
Preliminary Test ◽  
Bilayer Membrane ◽  
Microfluidic System ◽  
Culture Model ◽  
Before And After ◽  
Dynamic High Pressure

In recent decades, endogenous nanocarrier-exosomes have received considerable scientific interest as drug delivery systems. The unique proteo-lipid architecture allows the crossing of various natural barriers and protects exosomes cargo from degradation in the bloodstream. However, the presence of this bilayer membrane as well as their endogenous content make loading of exogenous molecules challenging. In the present work, we will investigate how to promote the manipulation of vesicles curvature by a high-pressure microfluidic system as a ground-breaking method for exosomes encapsulation. Exosomes isolated from Uppsala 87 Malignant Glioma (U87-MG) cell culture media were characterized before and after the treatment with high-pressure homogenization. Once their structural and biological stability were validated, we applied this novel method for the encapsulation in the lipidic exosomal bilayer of the chemotherapeutic Irinotecan HCl Trihydrate-CPT 11. Finally, we performed in vitro preliminary test to validate the nanobiointeraction of exosomes, uptake mechanisms, and cytotoxic effect in cell culture model.

scholarly journals Short-term dosage regimen for stimulation-induced long-lasting desynchronization

2017 ◽  
Author(s):  
Thanos Manos ◽  
Magteld Zeitler ◽  
Peter A. Tass
Keyword(s):  
Dosage Regimen ◽  
Computational Study ◽  
Spike Timing ◽  
Stimulation Frequency ◽  
Dose Finding ◽  
Short Term ◽  
Neuronal Synchrony ◽  
Stimulation Parameters ◽  
Human Dose ◽  
Parameter Values

AbstractIn this paper, we computationally generate hypotheses for dose-finding studies in the context of desynchronizing neuromodulation techniques. Abnormally strong neuronal synchronization is a hallmark of several brain disorders. Coordinated Reset (CR) stimulation is a spatio-temporally patterned stimulation technique that specifically aims at disrupting abnormal neuronal synchrony. In networks with spike-timing-dependent plasticity CR stimulation may ultimately cause an anti-kindling, i.e. an unlearning of abnormal synaptic connectivity and neuronal synchrony. This long-lasting desynchronization was theoretically predicted and verified in several pre-clinical and clinical studies. We have shown that CR stimulation with rapidly varying sequences (RVS) robustly induces an anti-kindling at low intensities e.g. if the CR stimulation frequency (i.e. stimulus pattern repetition rate) is in the range of the frequency of the neuronal oscillation. In contrast, CR stimulation with slowly varying sequences (SVS) turned out to induce an anti-kindling more strongly, but less robustly with respect to variations of the CR stimulation frequency. Motivated by clinical constraints and inspired by the spacing principle of learning theory, in this computational study we propose a short-term dosage regimen that enables a robust anti-kindling effect of both RVS and SVS CR stimulation, also for those parameter values where RVS and SVS CR stimulation previously turned out to be ineffective. Intriguingly, for the vast majority of parameter values tested, spaced multishot CR stimulation with demand-controlled variation of stimulation frequency and intensity caused a robust and pronounced anti-kindling. In contrast, spaced CR stimulation with fixed stimulation parameters as well as singleshot CR stimulation of equal integral duration failed to improve the stimulation outcome. In the model network under consideration, our short-term dosage regimen enables to robustly induce long-term desynchronization at comparably short stimulation duration and low integral stimulation duration. Currently, clinical proof of concept is available for deep brain CR stimulation for Parkinson’s therapy and acoustic CR stimulation for tinnitus therapy. Promising first in human data is available for vibrotactile CR stimulation for Parkinson’s treatment. For the clinical development of these treatments it is mandatory to perform dose-finding studies to reveal optimal stimulation parameters and dosage regimens. Our findings can straightforwardly be tested in human dose-finding studies.

scholarly journals TFPIβ is the GPI-anchored TFPI isoform on human endothelial cells and placental microsomes

Blood ◽  
2012 ◽  
Vol 119 (5) ◽  
pp. 1256-1262 ◽  
Author(s):  
Thomas J. Girard ◽  
Elodee Tuley ◽  
George J. Broze
Keyword(s):  
Endothelial Cells ◽  
Tissue Factor ◽  
Feedback Inhibition ◽  
Culture Media ◽  
Factor Viia ◽  
Factor Xa ◽  
Gpi Anchor ◽  
C Terminus ◽  
Before And After ◽  
Tissue Factor Pathway

Abstract Tissue factor pathway inhibitor (TFPI) produces factor Xa-dependent feedback inhibition of factor VIIa/tissue factor-induced coagulation. Messages for 2 isoforms of TFPI have been identified. TFPIα mRNA encodes a protein with an acidic N-terminus, 3 Kunitz-type protease inhibitor domains and a basic C-terminus that has been purified from plasma and culture media. TFPIβ mRNA encodes a form in which the Kunitz-3 and C-terminal domains of TFPIα are replaced with an alternative C-terminus that directs the attachment of a glycosylphosphatidylinositol (GPI) anchor, but whether TFPIβ protein is actually expressed is not clear. Moreover, previous studies have suggested that the predominant form of TFPI released from cells by phosphatidylinositol-specific phospholipase C (PIPLC) treatment is TFPIα, implying it is bound at cell surfaces to a separate GPI-anchored coreceptor. Our studies show that the form of TFPI released by PIPLC treatment of cultured endothelial cells and placental microsomes is actually TFPIβ based on (1) migration on SDS-PAGE before and after deglycosylation, (2) the lack of a Kunitz-3 domain, and (3) it contains a GPI anchor. Immunoassays demonstrate that, although endothelial cells secrete TFPIα, greater than 95% of the TFPI released by PIPLC treatment from the surface of endothelial cells and from placental microsomes is TFPIβ.

Condition Monitoring Technology for Connecting Part and Sliding Part of Reciprocating Compressor

2017 ◽  
Author(s):  
Yoshifumi Mori ◽  
Takashi Saito ◽  
Yu Mizobe
Keyword(s):  
Mathematical Model ◽  
Natural Frequencies ◽  
Error Function ◽  
Connecting Rod ◽  
Value Analysis ◽  
Before And After ◽  
The Difference ◽  
Bending Modes ◽  
Parameter Values ◽  
The Mathematical Model

We focused on vibration characteristics of reciprocating compressors and constructed the mathematical model to calculate the natural frequencies and modes for crank angles and proposed a method to estimate the degree and the suspicious portion of failure by difference of temporal parameter values obtained using measuring data in operation and the mathematical model. In this paper, according to the proposed method, a case study is carried out using the field data, where the data were acquired before and after the failures occurred in the connecting parts of connecting rod, to prospect the difference between each parameter value for two operating states. Inspecting resonant characteristics each in the frequency response data relating to the natural frequencies for bending modes of the piston rod, we determined two resonant frequencies, which could correspond to the 1st and 2nd mode about bending of the piston rod. To equate the calculated each natural frequency from eigen value analysis based on the proposed model with each resonant frequency, we define the error function for the identified problem, namely optimum problem. In the identified results, it is found that some parameter values have much difference and the corresponding failure could occur around the connecting rod. We could show the possibility to detect both the change of the parameter values and the deterioration parts for two different kinds of the operating states by our proposed method.

A computational study of the interactions between anthocyans and cyclodextrins

2020 ◽  
Vol 75 (11-12) ◽  
pp. 433-441
Author(s):  
Raluca Pop ◽  
Adina Căta ◽  
Mariana Nela Ștefănuț ◽  
Ioana Maria Carmen Ienașcu
Keyword(s):  
Hydrogen Bonds ◽  
Inclusion Complexes ◽  
Acidic Medium ◽  
Ph Value ◽  
Computational Study ◽  
Dependence Structure ◽  
Computational Techniques ◽  
Oh Groups ◽  
Alkaline Environment

AbstractThe interactions between six anthocyans (cyanidin-3-O-glucoside, delphinidin-3-O-glucoside, malvidin-3-O-glucoside, cyanidin-3-O-rutinoside, delphinidin-3-O-rutinoside, malvidin-3-O-rutinoside) and cyclodextrins were investigated by means of computational techniques. Four different structures of the aforementioned anthocyans were considered, as a result of the dependence structure – pH value (flavylium cations in acidic medium, hemiketals in neutral solutions and two tautomeric quinones in alkaline environment). The results outlined that the anthocyanidin-3-O-rutinoside are favored for the obtaining of inclusion complexes with the cyclodextrins, mostly due to the larger number of OH groups involved in the formation of hydrogen bonds. For all the four types of structures, best results have been obtained for β- and γ-cyclodextrins.

Research on the Effects of Roughness on the Tactile Properties of Rice Straw Particleboard Surface

2020 ◽  
Vol 12 (6) ◽  
pp. 795-801 ◽  
Author(s):  
Xian-Qing Xiong ◽  
Ying-Ying Yuan ◽  
Yi-Ting Niu ◽  
Liang-Ting Zhang
Keyword(s):  
Surface Roughness ◽  
Rice Straw ◽  
Interior Design ◽  
Roughness Parameter ◽  
Chemical Properties ◽  
Mesh Size ◽  
Design Guidelines ◽  
Before And After ◽  
The Difference ◽  
Parameter Values

To explore the effects of roughness on the tactile properties of rice straw particleboard (RSP), the surface roughness and psychological tactile and visual experiments were conducted for RSP substrates with 0.76 g/cm3 and 0.55 g/cm3 densities after sanding with sandpaper (mesh 180#, 360#, and 600#). The effects of different sandpaper types, sanding time, and density of RSP on the surface roughness were analyzed. The experimental results are as follows. The sanding treatment had significant influence on the surface roughness characterization parameters Ra and Rpv of the RSP specimens. Surface roughness differences between the 180# and 360# mesh-prepared samples were obvious. The tactile and visual psychological values of the 360# and 600# mesh-sanded specimens were higher, and the psychological quantities of untreated and 180# mesh-sanded specimens were lower. After comparing the samples with sanding treatment of sandpaper 0∼180#, the change in surface roughness of RSP with a density of 0.76 g/cm3 was smaller than that of the specimen with a density of 0.55 g/cm3. The psychological quantity difference of RSP specimens with a density of 0.55 g/cm3 was evident. When the sanding time was 1 min., the values of the roughness characterization parameters Ra and Rpv increased slightly. After 3 min. sanding, the Ra and Rpv values stabilized. When the sanding time was 5 min, the roughness was essentially unchanged. With the change in sanding time, the measured values of the tactile psychological quantity varied greatly and the measured values of the visual psychology were very close. For the RSP substrates with higher density, the surface roughness was less after sanding with a smoother surface and better tactile properties. There were significant differences between the surface roughness of the RSPs before and after sanding. After manual sanding over the same time span, the surface roughness evaluation parameter values decreased with an increase of mesh size of the sandpaper, and the tactile properties were improved. The longer the sanding time, the smaller the difference in the surface roughness parameter values, and the smaller the difference between the tactile psychological quantity and the visual psychological quantity. To expand the research scope of RSP products, this study investigates not only the physical and chemical properties but also the subjective feelings when using the RSP products. This will provide analytical methods and design guidelines for the consideration of environmental factors in furniture and interior design.

Effects of Geometrical Shapes and Orientations of Metal Foams Subjected to Impact Loading

2014 ◽  
Vol 564 ◽  
pp. 31-37 ◽  
Author(s):  
M. Ghazali Kamardan ◽  
Ahmad Mujahid Ahmad Zaidi ◽  
Z. Fitri Z. Abidin ◽  
M. Noh Dalimin ◽  
Othman Mohd Zaid
Keyword(s):  
Impact Loading ◽  
Metal Foam ◽  
Dynamic Deformation ◽  
Foam Cell ◽  
Deformation Behaviour ◽  
Metal Foams ◽  
Geometrical Shapes ◽  
Shape Effects ◽  
Parameter Values ◽  
Two Parameter

The effects of geometrical shapes are believed to play significant role in the deformation of metal foams under impact loading. This research was carried out to investigate the deformation behaviour of a single cellular cell of metal foam with different geometrical shapes. The simulation analyses were done on various two dimensional shapes with the consideration of the material properties. Two parameter values had been studied to determine the dynamic deformation behaviour of various geometrical shapes i.e. the internal energy and kinetic energy. It is found that, the geometrical shapes have shown significant effects on the dynamic deformation of single metal foam cell. It is hoped that this study could contribute significant result to the research of the metal foams especially in analyzing the shape effects to the behaviour of the metal foam under impact loading.

Morphology of Polythiophene Films Produced via Surface Polymerization by Ion-Assisted Deposition: A Combined Experimental and Computational Study

2006 ◽  
Vol 937 ◽  
Author(s):  
Sanja Tepavcevic ◽  
Wen-Dung Hsu ◽  
Susan B Sinnott ◽  
Luke Hanley
Keyword(s):  
Density Functional ◽  
Computational Study ◽  
Growth Patterns ◽  
Limiting Factors ◽  
Computational Techniques ◽  
Thermal Processes ◽  
Film Morphology ◽  
Dynamic Simulations ◽  
Surface Polymerization ◽  
Chemical Events

ABSTRACTControl of film morphology is widely recognized as one of the limiting factors in the development of conjugated polymers for photonic and electronic applications. Surface polymerization by ion-assisted deposition (SPIAD) is shown to drive film morphology. A wide variety of structures form in the SPIAD polythiophene films, including islands, lamellar structures, nanoscale crystallites, and fractal-like growth patterns. Density functional theory-molecular dynamic simulations are utilized to illustrate the manner in the incident ions affect polymerization, bond dissociation, and other chemical events in SPIAD. These ion-assisted events mediate thermal processes such as neutral deposition, sublimation, diffusion, and dewetting. However, these thermal processes are on longer timescales that cannot be directly studied by the computational techniques reported here.

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