Mass Transfer Analysis of Growth and Substance Metabolism of NSCs Cultured in Collagen-Based Scaffold In Vitro

2014 ◽  
Vol 174 (6) ◽  
pp. 2114-2130 ◽  
Author(s):  
Kedong Song ◽  
Dan Ge ◽  
Shui Guan ◽  
Chenggong Sun ◽  
Xuehu Ma ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Substance Metabolism

scholarly journals Hydrocolloids in human digestion: Dynamic in-vitro assessment of the effect of food formulation on mass transfer

2014 ◽  
Vol 42 ◽  
pp. 378-385 ◽  
Author(s):  
O. Gouseti ◽  
M.R. Jaime-Fonseca ◽  
P.J. Fryer ◽  
C. Mills ◽  
M.S.J. Wickham ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Effect Of Food ◽  
In Vitro Assessment

Biological plywood film formation from para-nematic liquid crystalline organization

Soft Matter ◽  
2017 ◽  
Vol 13 (44) ◽  
pp. 8076-8088 ◽  
Author(s):  
Oscar F. Aguilar Gutierrez ◽  
Alejandro D. Rey
Keyword(s):  
Mass Transfer ◽  
Liquid Crystalline ◽  
Film Formation ◽  
Relative Speed ◽  
Chiral Phase ◽  
Phase Ordering ◽  
Non Equilibrium

The coupling of mass transfer and chiral phase ordering present in non-equilibriumin vitrodrying of biomacromolecules leading to different microstructures depending on the relative speed of both processes.

Analysis of Ultrafiltration and Mass Transfer in a Bioartificial Pancreas

1988 ◽  
Vol 110 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. Y. Jaffrin ◽  
G. Reach ◽  
D. Notelet
Keyword(s):  
Mass Transfer ◽  
Reverse Direction ◽  
Hydraulic Permeability ◽  
Bioartificial Pancreas ◽  
Permeable Membrane ◽  
Insulin Secreting Cells ◽  
Flat Membrane ◽  
Polyacrylonitrile Membrane ◽  
In Vitro Data

A bioartificial pancreas is an implantable device which contains insulin secreting cells (Langerhans islets), separated from the circulating blood by a semi-permeable membrane to avoid rejection. This paper describes the operation of such a device and evaluates the respective contributions of diffusion and ultrafiltration to the glucose and insulin mass transfer. It is shown that the pressure drop along the blood channel produces across the first half of the channel an ultrafiltration flux toward the islet compartment followed in the second half by an equal flux in reverse direction from islets to blood. The mass transfer analysis is carried out for an optimal geometry in which a U-shaped blood channel surrounds closely a very thin islet compartment formed by a folded flat membrane. A complete model of insulin release by this device is developed and is compared with in vitro data obtained with rats islets. Satisfactory kinetics is achieved with a polyacrylonitrile membrane used in hemodialysis. But the model shows that the membrane hydraulic permeability should be increased by a factor of 10 to significantly improve the performance.

Simultaneous Convective and Diffusive Mass Transfers in a Hemodialyser

1990 ◽  
Vol 112 (2) ◽  
pp. 212-219 ◽  
Author(s):  
Michel Y. Jaffrin ◽  
Luhui Ding ◽  
Jean Marc Laurent
Keyword(s):  
Mass Transfer ◽  
Blood Flow ◽  
Boundary Layers ◽  
Flow Rate ◽  
Local Blood Flow ◽  
Mass Fluxes ◽  
In Vitro Measurements ◽  
Mass Transfers ◽  
Good Agreement

The mass transfer in a hemodialyser in the presence of combined dialysis and ultrafiltration has been calculated by integration of mass fluxes across the boundary layers in blood and dialysate phase taking into account the partial rejection of solute as well as changes in local blood flow and ultrafiltration flux along the membrane. Clearances of creatinin, vitamin B12, and myoglobin have been calculated as a function of blood and ultrafiltrate flow rate and were found to be in good agreement with in vitro measurements. The data suggest the following empirical correlation for the hemodiafiltration clearance CL=CLD+0.46QF where QF is the ultrafiltration flow rate and CLD is the clearance at QF=0.

scholarly journals Characterization of different biocatalyst formats for BVMO-catalyzed cyclohexanone oxidation

2021 ◽  
Author(s):  
Lisa Bretschneider ◽  
Ingeborg Heuschkel ◽  
Afaq Ahmed ◽  
Katja Bühler ◽  
Rohan Karande ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Process Stability ◽  
Cyclic Ketones ◽  
Nadph Regeneration ◽  
Cyclohexanone Monooxygenase ◽  
Whole Cells ◽  
Suspended Cells ◽  
Substrate Spectrum

Cyclohexanone monooxygenase (CHMO), a member of the Baeyer-Villiger monooxygenase family, is a versatile biocatalyst that efficiently catalyzes the conversion of cyclic ketones to lactones. In this study, an Acidovorax-derived CHMO gene was expressed in Pseudomonas taiwanensis VLB120. Upon purification, the enzyme was characterized in vitro and shown to feature a broad substrate spectrum and up to 100% conversion in 6 h. Further, we determined and compared the cyclohexanone conversion kinetics for different CHMO-biocatalyst formats, i.e., isolated enzyme, suspended whole cells, and biofilms, the latter two based on recombinant CHMO-containing P. taiwanensis VLB120. Biofilms showed less favorable values for K (9.3-fold higher) and k (4.8-fold lower) compared to corresponding K and k values of isolated CHMO, but a favorable K for cyclohexanone (5.3-fold higher). The unfavorable K and k values are related to mass transfer- and possibly heterogeneity issues and deserve further investigation and engineering, in order to exploit the high potential of biofilms regarding process stability. Suspended cells showed an only 1.8-fold higher K, but 1.3- and 4.2-fold higher k and K values than isolated CHMO. This together with the efficient NADPH regeneration via glucose metabolism makes this format highly promising from a kinetics perspective.

scholarly journals Breed Differences in the Expression Levels of gga-miR-222a in Laying Hens Influenced H2S Production by Regulating Methionine Synthase Genes in Gut Bacteria

2020 ◽  
Author(s):  
Sicheng Xing ◽  
Chunbo Huang ◽  
Yiwen Yang ◽  
Jingyuan Chen ◽  
Jiandui Mi ◽  
...  
Keyword(s):  
Laying Hens ◽  
Expression Profiles ◽  
Gas Production ◽  
Methionine Synthase ◽  
Differentially Expressed ◽  
Cecal Content ◽  
Differentially Expressed Mirnas ◽  
Microbial Genes ◽  
Substance Metabolism

Abstract Background: The microbiota in the cecum of laying hens is critical for substance metabolism and odor gas production. Recent studies have suggested that host miRNAs can regulate gene expression in the gut microbiota. The expression profiles of host-derived miRNAs in the cecal content of two laying hen breeds, Hy-line Gray and Lohmann Pink, which have dissimilar H2S production, were characterized, and their possible effects on H2S production by regulating the expression of related genes in the microbiota were demonstrated. Results: The differential expression of microbial serine O-acetyltransferase, methionine synthase, aspartate aminotransferase, methionine-gamma-lyase and adenylylsulfate kinase between the two breeds resulted in lower H2S production in the Hy-line hens. The results also demonstrated miRNA microvesicles in the cecal content of laying hens and found potential miRNA-target relationships between 9 differentially expressed miRNAs and 9 differentially expressed microbial genes related to H2S production, among which gga-miR-222a targeted two methionine synthase genes, Odosp_3416 and BF9343_2953. An in vitro fermentation experiment showed that gga-miR-222a upregulated the expression of these genes, which increased methionine concentrations but decreased H2S production and soluble sulfide concentrations, indicating the potential of host-derived gga-miR-222a to reduce H2S emission in laying hens. Conclusion: These findings identify both a physiologic role by which miRNA shapes the cecal microbiota of laying hens and a strategy to use host miRNAs to manipulate the microbiome and actively expressed key microbial genes to reduce H2S emission and breed environmentally friendly laying hens.

scholarly journals Nonsteroidal Anti-Inflammatory Drug Solid-State Microencapsulation on Green Activated Carbon - Mass Transfer and Host-Guest Interactions

2019 ◽  
Vol 33 (2) ◽  
pp. 249-269 ◽  
Author(s):  
Zvezdelina Lyubenova Yaneva
Keyword(s):  
Mass Transfer ◽  
Activated Carbon ◽  
Solid Phase ◽  
Drug Carrier ◽  
In Vitro Release ◽  
Inflammatory Drug ◽  
Mass Transfer Mechanism ◽  
Carbon Mass ◽  
Anti Inflammatory

The present study investigated the drug-carrier capacity of green activated carbon derived from fruit stones by steam-gas activation (ACSTA) towards the nonsteroidal anti-inflammatory drug (NSAID) ibuprofen (IBU), and assessed the host-guest interactions and mass transfer mechanism/s of the drug microencapsulation and in vitro release processes. The mass transfer studies outlined that the process of IBU encapsulation on ACSTA microparticles was predominantly controlled by intraparticle solid phase diffusion.

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