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Volume 26 (2001)
- Issue 6 Pages 236-
- Issue 5 Pages 194-
- Issue 4 Pages 164-
- Issue 3 Pages 110-
- Issue 2 Pages 66-
- Issue 1 Pages 2-
Volume 26, Issue 2
Displaying 1-6 of 6 articles from this issue
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Hiroshi Fujise2001 Volume 26 Issue 2 Pages 66-71
Published: March 01, 2001
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSTransports of water and gases through cell membranes have conventionally been considered to diffuse across the lipid bilayer. Recently, however, it was reported that water transport was mediated by water channel, aquaporin (AQP). Gas permeation, such as CO2 and NH3, was greatly restricted by the apical membrane in epithelia of the urinary tract or colon crypt, a restriction not explained by diffusion. The reason for this low permeation rate was considered to be the difference in lipid composition of the cell membranes. On the other hand, band 3 and AQP have been suggested as possible gas or CO2 channels. In 1998, several reports indicated that AQP1 enhanced CO2 permeation of cell membranes or might be the CO2 channel, although other study disagreed. Recent studies on gas permeation of the cell membrane mediated by protein or an as yet unspecified channel were reviewed.View full abstractDownload PDF (775K) -
Ikuko Tsukamoto2001 Volume 26 Issue 2 Pages 72-78
Published: March 01, 2001
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSBesides O2 and CO2, many small molecules can be transferred between respiratory gases and blood. There is an alveocapillary membrane between respiratory gases and blood, that consists of alveolar epithelium and capillary endothelium, and gases should transfer via these cell membranes. Artificial lungs consist of polypropylene membranes, of which the thickness is nearly the same as that of the thin portion of the alveocapillary membrane in natural lungs (-0.5μm).
Volatile anesthetics are administered with inspired gas, and anesthetic molecules transter and interact with biomembranes to cause anesthesia. Both the interactions between anesthetics and functional proteins and those between anesthetics and membrane lipids are important to induce anesthesia. Membrane lipids are not simply the supporting matrix of the functional proteins, they also sometimes control the function of proteins.
In patients poisoned with volatile compounds, some of the compounds are usually eliminated in the expired gas. Since the method of obtaining expired gas is the least invasive, it may be the most practical sample to monitor cases of poisoning.
The gas transfer at alveolar provides much useful information about the body condition.View full abstractDownload PDF (1005K) -
Kenji Haraya2001 Volume 26 Issue 2 Pages 79-85
Published: March 01, 2001
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe present article reviews the outline of gas transport mechanism through membranes, such as sorption diffusion, molecular sieving, surface diffusion and Knudsen flow, and the recent development of design methods and fabrication techniques to improve performance of membranes made from polymeric and inorganic materials. Transport mechanism through micro pore influenced by mutual gas pair and pore shape is also introduced. In addition, the way how breaks through the trade-off relation between gas permeability and selectivity is discussed.View full abstractDownload PDF (1011K) -
Electric percolation phenomena and solubilization state of protein in reverse micellar organic mediaKazumitsu Naoe, Chiharu Matsumoto, Seiji Morii, Saki Kumano, Mikio Kaw ...2001 Volume 26 Issue 2 Pages 86-94
Published: March 01, 2001
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSElectric percolation phenomena of reverse micellar organic phase of sodium bis (2-ethylhexyl) sulfosuccinate (AOT) were investigated. Solubilization of electrolytes into the micellar water pool depressed the percolation between reverse micelles and increased the percolation temperature. In particular, caotropic GuHSCN and strong electrolyte KCl increased the percolation temperature more effectively. Solubilization of low-molecular-weight proteins into the micellar phase induced the percolation processes and lowered the percolation temperature, which was dependent on the protein concentration solubilized. The magnitude order of effectiveness of the protein on the percolation was cytochrome c > lysozyme > ribonuclease A. The efficiency of each protein in promoting percolation corresponded to its local solubilizing state in the micelles. In the cases of solubilizing both the electrolyte and the protein, the percolation processes were mutually affected by each additive. In the reverse micellar systems formed by different organic solvents (C6-10 alkane), the percolation temperature was linearly decreased with molecular volume of the solvent. The shift of the percolation temperature due to protein solubilization (ΔTp) depended upon the solvent molecular volume and the protein species. In the case of lysozyme, ΔTp increased with the molecular volume of solvent, while ΔTp of cytochrome c showed the minimum value at the molecular volume of C8-9 alkane.View full abstractDownload PDF (1207K) -
Toshinori Tsuru, Reiko Miyashita, Shin-ichi Nakao, Kenji Haraya2001 Volume 26 Issue 2 Pages 95-103
Published: March 01, 2001
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSComputer simulation was carried out for the system of ternary gaseous mixtures where the object component had the intermediate permeance among the mixtures. As for the model system of the 3-component mixtures, the gaseous mixtures of N2/CO2/H2O having molar compositions of 0.78/ 0.12/ 0.10, which is a typical composition of flue gases, were separated by a single permeator and two stage modules of various configurations with membrane permeances in the order of H2O> CO2> N2. Two-stage cascade configuration improved CO2 concentration in product stream in comparison with a single permeator, while the power consumption increased. Among three types of configuration of two-stage modules : permeate product of two-stage membrane series (abbreviated as PR-TSS), permeate product of two-stage membrane cascade (PP-TSC) and retentate product of two-stage membrane cascade (RP-TSC), the RP-TSC was found to be the best configuration for concentrating CO2 which has the intermediate permeance among the feed gases.View full abstractDownload PDF (1026K) -
Masao Kikuchi, Yoshihiro Kusuki2001 Volume 26 Issue 2 Pages 104-106
Published: March 01, 2001
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSUBE's process is based on the dehydration in vapor phase. Use of BPDA-polyimide makes it possible to produce a membrane with characteristics that include good water vapor permeation and excellent durability. The ethanol dehydration process has been used in UBE's chemical plant since 1990, resulting in reduced operating cost and improved operational stability. The IPA refinery system has been used in the LSI plant since 1993 and it also has produced good operating result.View full abstractDownload PDF (495K)
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