巻号一覧
24 巻 (1999)
- 6 号 p. 310-
- 5 号 p. 238-
- 4 号 p. 194-
- 3 号 p. 144-
- 2 号 p. 78-
- 1 号 p. 2-
24 巻, 4 号
選択された号の論文の6件中1～6を表示しています
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香川 靖雄1999 年 24 巻 4 号 p. 194-199
発行日: 1999/07/01
公開日: 2011/03/04
ジャーナル フリーATP synthase is the central enzyme for energy supply of cells. It is composed of a membrane portion (Fo) and a catalytic portion (F1). F1 is composed of 5 kinds of subunits (α3β3γδε), in which each α1β1 protomer has ATP-binding site. The α3β3 oligomer structure is needed for cooperativity of rapid ATP synthesis. Both the protomer and oligomer were reconstituted only in the case of thermophilic F1 (TF1). The basic structure of Fo is ab2c12. X-ray crystallography and nanomechanics of F1 demonstrated the intramolecular rotation of c-γ axis, which is driven by the electrochemical potential difference of protons (ΔμH+) across the membrane. Recent biological studies using mtDNA-less cell (ρ0 cell) by membrane fusion, and human genetics are also described. The uncoupling proteins dissipate ΔμH+to protect mitochondrial membrane.抄録全体を表示PDF形式でダウンロード (767K) -
川上 浩良1999 年 24 巻 4 号 p. 200-206
発行日: 1999/07/01
公開日: 2011/03/04
ジャーナル フリーIn this paper, a new possibility for gas separation is presented using an asymmetric fluorinated polyimide membrane with an ultrathin and defect-free skin layer. The structure of the asymmetric membrane prepared by a dry/wet phase inversion process shows an ultrathin skin layer and sponge-like structure characterized by the presence of macrovoids. The gas selectivity of the membrane increases with a decrease in the surface skin layer thickness, which may be due to the fact that the surface skin layer of the membrane with a thinner thickness forms a more packed structure. The stability of gas permeance in the membranes is also discussed. Additionally, a fluorinated polyimide hollow fiber has been synthesized to develop a novel membrane material for oxygenator. An asymmetric polyimide hollow fiber has also been prepared by the dry/wet phase invension spinning process. The asymmetric hollow fiber has two advantages ; (1) the hollow fiber dose not occur plasma leakage due to the dense skin layer of the surface and (2) O2 and CO2 transfer rates through the hollow fiber enhance due to the ultrathin skin layer and are significantly larger than those of presently available membrane oxygenator. The fluorinated polyimide also shows an excellent blood compatibility.抄録全体を表示PDF形式でダウンロード (1411K) -
高橋 浩1999 年 24 巻 4 号 p. 207-214
発行日: 1999/07/01
公開日: 2011/03/04
ジャーナル フリーDisaccharides and sugar alcohols have the ability to protect some organisms against low temperatures. In order to clarify the cryoprotective mechanism of these sugars, we have investigated the interactions of these sugars with phospholipids which are main component of biomembranes. For this purpose, simultaneous calorimetry/x-ray diffraction measurement and neutron solution scattering contrast variation method were used to study the structures and phase behavior of dihexadecyphosphatidylcholine (DHPC) in trehalose solution and the micelle structure of dihexanolyphosphatiodylcholine (dC (6) PC) in sorbitol solution, respectively. Following results were obtained : (1) Trehalose destabilizes the interdigitated gel phase structure of DHPC membranes and then the normal gel phase structure is formed in a trehalose solution with more than 1.2 M concentration. (2) As compared with dC (6) PC micelles in pure water, the aggregation number for the dC (6) PC micelles in 2.0 M sorbitol solution increases and on the other hand, the volume of per a single molecule in the micelle decreases. These results show that trehalose and sorbitol reduce the contact area between the lipid and aqueous phase. On the basis of this conclusion, we discuss the role of disaccharides and sugar alcohols for the ability of some organisms to survive at low temperatures.抄録全体を表示PDF形式でダウンロード (932K) -
永井 一清, 大野 正広, 仲川 勤1999 年 24 巻 4 号 p. 215-220
発行日: 1999/07/01
公開日: 2011/03/04
ジャーナル フリーCompared to other glassy polymers, poly (1-trimethylsilyl-1-propyne) [PMSP] has an extraordinarily large unrelaxed free volume, making PMSP the most permeable polymer known. In this paper, the gas permeabilities of PMSP films filled with polydimethylsiloxane [PDMS] and polyethylene glycol [PEG] are discussed. PMSP films were filled with PDMS and PEG by immersing the films in PDMS/ methyl ethyl ketone and PEG/1, 1, 2-trichloroethane solutions, respectively. The PDMS and PEG used were PDMS1000cs (Mw=3×104), PDMS100cs (Mw=6×103), PDMS10cs (Mw=1×103), and PEG6000 (Mw=6×103). Macro domains of PDMS and PEG oligomers are not formed in the filled PMSP films because no peaks appear in the DSC curves for the filled films. As PEG or PDMS content in the filled PMSP films increases, both the permeability coefficient and the equilibrium sorption concentration of carbon dioxide in these films decrease, while the separation factor for carbon dioxide over nitrogen increases. Compared to the carbon dioxide permeability of PDMS-filled PMSP films, the permeability of carbon dioxide is higher for PMSP films containing less than 20 wt% PEG and lower for films containing more than 20 wt% PEG. These results suggest that the gas sorption, diffusion, and permeation properties of filled PMSP films depend on oligomer content and morphology of the filled films.抄録全体を表示PDF形式でダウンロード (651K) -
加賀美 和宏, 大木 和夫1999 年 24 巻 4 号 p. 221-229
発行日: 1999/07/01
公開日: 2011/03/04
ジャーナル フリーThe mechanisms of intracellular transport of lipids and asymmetric distribution of membrane lipids were still unknown. The intracellular transport of fluorescent phosphatidylserine analogues, 1-palmitoyl-2- (N- [12 [(7-nitrobenz-2-oxa-1, 3-diazole-4-yl) amino] dodecanoyl]) -phosphatidylserine (C12-NBD-PS) and 1-palmitoyl-2- (N- [6 [(7-nitrobenz-2-oxa-1, 3-diazole-4-yl) amino] caproyl]) -phosphatidylserine (C6-NBD-PS) was investigated in CHO cells. When CHO cells were incubated with liposomes containing C12-NBD-PS for 30 min at 37°C, fluorescent PS appeared in the Golgi apparatus. On the other hand, C6-NBD-PS was observed in the intracellular membrane systems but not in the Golgi apparatus under the same experimental conditions.To investigate transport of C12-NBD-PS to the Golgi apparatus further, the plasma membranes of CHO cells were selectively perforated with θ-toxin from Clostridium perfringens and the cytosol was replaced by rat brain cytosol, ATP and Ca2+. In order to establish the optimal condition of cell permeabilization, release of lactate dehydrogenase (LD) activity from the CHO cells was determined as function of temperature, time of incubation and θ-toxin concentration. Then C12-NBD-PS transport to the Golgi apparatus was examined under various conditions.Incubation of the perforated cells with rat brain cytosol, ATP and Ca2+ results in reconstitution of transport of C12-NBD-PS to the Golgi apparatus. However in the absence of rat brain cytosol or ATP, this transport was not recovered. The results suggest that PS specific transport protein is involved in the transport of phosphatidylserine to the Golgi apparatus in CHO cells.抄録全体を表示PDF形式でダウンロード (2480K) -
浅原 智彦, 内藤 寿真子1999 年 24 巻 4 号 p. 234-235
発行日: 1999/07/01
公開日: 2011/03/04
ジャーナル フリーBIOCLUSIVE® H, polyurethane wound dressing with High Vapor Transmission Rate (HVTR), was developed. The product is mainly used for burn, ulcer, dermal-graft treatment, or post-surgical control in the hospital. The technical requirements to the product are, high vapor transmission rate, transparency, adhesiveness, handling, and sterile. Ultra-thin polyurethane film and adhesive (both HVTR) technologies are combined to this end.抄録全体を表示PDF形式でダウンロード (291K)
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