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Elucidating the state of interfacial water, especially the hydrogen-bond configurations, is considered to be key for a better understanding of the functions of polymers that are exhibited in the presence of water. Here, an analysis in this direction is conducted for two water-insoluble biocompatible polymers, poly(2-methoxyethyl acrylate) and cyclic(poly(2-methoxyethyl acrylate)), and a non-biocompatible polymer, poly(

There is a long, ongoing debate on how small molecules (osmolytes) affect the stability of proteins. The present study found that change in collective rotational dynamics of water in osmolyte solutions likely has a dominant effect on protein denaturation. According to THz spectroscopy analysis, osmolytes that stabilize proteins are accompanied by bound hydration water with slow dynamics, while the collective rotational dynamics of water is accelerated in the case of denaturant osmolytes. Among 15 osmolytes studied here, there is a good correlation between the change in mobility in terms of water rotational dynamics and the denaturation temperature of ribonuclease A. The changes in water dynamics due to osmolytes can be regarded as a pseudo-temperature-change, which agrees well with the change in protein denaturation temperature. These results indicate that the molecular dynamics of water around the protein is a key factor for protein denaturation.

In some synthetic polymers used for medical applications, hydration water in the vicinity of the polymer chains is known to play an important role in biocompatibility and is referred to as intermediate water. The crystallization of water below 0 °C observed during thermal analysis has been considered as evidence of the presence of intermediate water. However, the origin and physicochemical properties of intermediate water have not yet been elucidated. In this study, as a typical biocompatible polymer, poly(ethylene oxide) and its hydration water were investigated with the use of terahertz time-domain spectroscopy and quasi-elastic neutron scattering. The obtained results prove the existence of a significant amount of mobile water that interacts with the polymer chains even when the water content is low at physiological temperatures.

Poly(2-methoxyethyl acrylate) (PMEA) is known to exhibit excellent thromboresistance, i.e., hardly causing blood-clot formation on its surface. Hence, PMEA and its analogues have been commercially used for blood-contacting materials in medical devices. In this study, we investigated the conformation and solvation state of PMEA in mixtures of tetrahydrofuran (THF) and water with various water volume fractions (ϕwater) by viscosity, sedimentation equilibrium, small-angle X-ray scattering (SAXS), and dielectric relaxation measurements. We also comparatively investigated those of poly[2-(2-methoxyethoxy)ethyl methacrylate] (PMe2MA) and polystyrene (PS). For all of these, THF is a good solvent and water is a nonsolvent or poor solvent. PMe2MA and PMEA show equally good thromboresistance, while PS does not at all. The solution properties of PMe2MA and PMEA were found to be quite different from PS. There are clear attractive interactions (or correlation) between the PMEA chain (or PMe2MA) and the waters in the vicinity of the chain despite their water insolubility. These correlated waters give additional scattering and the angular dependence of SAXS was analyzed in terms of the hydration layer model that has been used in protein solution scattering. The hydration is related to increasing both the chain stiffness and excluded volume. These distinctive properties are likely related to the origin of its good thromboresistance.

Intermediate water (IW), which is formed not only by biocompatible polymers such as poly(2-methoxyethyl acrylate) (PMEA), but also by biomacromolecules, plays a key role in determining the biocompatibility of synthetic polymers. In this study, we compare the well-defined linear and cyclic PMEA using differential scanning calorimetry and atomic force microscopy. This study aims to clarify the role of the chain-end effect in IW formation to establish design guidelines for biomaterials.

When biomaterials come into contact with biological fluids, water molecules immediately adsorb onto the surface of the materials. To understand the origin of the crucial roles of water molecules in...

The regulation of adhesion and the subsequent behavior of fibroblast cells on the surface of biomaterials is important for successful tissue regeneration and wound healing by implanted biomaterials. We have synthesized poly(ω-methoxyalkyl acrylate)s (PMCxAs, x indicates the number of methylene carbons between the ester and ethyl oxygen), with a carbon chain length of x = 2–6, to investigate the regulation of fibroblast cell behavior including adhesion, proliferation, migration, differentiation and collagen production. We found that PMC2A suppressed the cell spreading, protein adsorption, formation of focal adhesion, and differentiation of normal human dermal fibroblasts, while PMC4A surfaces enhanced them compared to other PMCxAs. Our findings suggest that fibroblast activities attached to the PMCxA substrates can be modified by changing the number of methylene carbons in the side chains of the polymers. These results indicate that PMCxAs could be useful coating materials for use in skin regeneration and wound dressing applications.

Confluent monolayers of human umbilical vein endothelial cells (HUVECs) on a poly(2-methoxyethyl acrylate) (PMEA) antithrombogenic surface play a major role in mimicking the inner surface of native blood vessels. In this study, we extensively investigated the behavior of cell–polymer and cell–cell interactions by measuring adhesion strength using single-cell force spectroscopy. In addition, the attachment and migration of HUVECs on PMEA-analogous substrates were detected, and the migration rate was estimated. Moreover, the bilateral migration of HUVECs between two adjacent surfaces was observed. Furthermore, the outer surface of HUVEC was examined using frequency-modulation atomic force microscopy (FM-AFM). Hydration was found to be an indication of a healthy glycocalyx layer. The results were compared with the hydration states of individual PMEA-analogous polymers to understand the adhesion mechanism between the cells and substrates in the interface region. HUVECs could attach and spread on the PMEA surface with stronger adhesion strength than self-adhesion strength, and migration occurred over the surface of analogue polymers. We confirmed that platelets could not adhere to HUVEC monolayers cultured on the PMEA surface. FM-AFM images revealed a hydration layer on the HUVEC surfaces, indicating the presence of components of the glycocalyx layer in the presence of intermediate water. Our findings show that PMEA can mimic original blood vessels through an antithrombogenic HUVEC monolayer and is thus suitable for the construction of artificial small-diameter blood vessels.

Materials exhibiting "bio-inert properties" are essential for developing medical devices because they are less recognized as foreign substances by proteins and cells in the living body. We have reported that the presence of intermediate water (IW) with the water molecules loosely bound to a polymer is a useful index of the bio-inertness of materials. Here, we analyzed the hydration state and the responses to biomolecules of poly(2-hydroxyethyl methacrylate) (PHEMA) copolymers including small amounts of 2-(dimethylamino)ethyl methacrylate (DMAEMA) (N-series) or/and 2,2,2-trifluoroethyl methacrylate (TFEMA) (F-series). The hydration structure was analyzed by differential scanning calorimetry (DSC), the molecular mobility of the produced copolymers by temperature derivative of DSC (DDSC), and the water mobility by solid H-1 pulse nuclear magnetic resonance (NMR). Although the homopolymers did not show bio-inert properties, the binary and ternary PHEMA copolymers with low comonomer contents showed higher bio-inert properties than those of PHEMA homopolymers. The hydration state of PHEMA was changed by introducing a small amount of comonomers. The mobility of both water molecules and hydrated polymers was changed in the N-series nonfreezing water (NFW) with the water molecules tightly bound to a polymer and was shifted to high-mobility IW and free water (FW) with the water molecules scarcely bound to a polymer. On the other hand, in the F-series, FW turned to IW and NFW. Additionally, a synergetic effect was postulated when both comonomers coexist in the copolymers of HEMA, which was expressed by widening the temperature range of cold crystallization, contributing to further improvement of the bio-inert properties.

Objectives: Management of unstable intertrochanteric fractures is challenging, especially in patients with osteoporosis. Comminuted unstable intertrochanteric fractures require postoperative immobilization. Several recent reports have recommended hemiarthroplasty for treatment of unstable intertrochanteric fractures to avoid various immobilization-associated complications. The purpose of this study was to evaluate the functional and clinical outcomes of bipolar hemiarthroplasty for unstable intertrochanteric fractures in older persons. Methods: Sixty patients aged over 75 years underwent hemiarthroplasty to treat unstable intertrochanteric fractures and were followed up over 12 months. All surgeries were performed by the same surgical team using the standard posterolateral approach. Wires, cables, and plates were used as required. Use of cemented protheses was considered when the lesser trochanter had been displaced. All patients were allowed full weight-bearing as tolerated. Clinical evaluation was based on Harris Hip Scores. Results: The cohort comprised 16 men and 44 women (aged 75–96 years). According to the Jensen classification, 24 fractures were type III, 14 type IV, and 22 type V. Cement was used in 24 patients. At 12 months follow-up, Harris Hip Scores were excellent in 18%, good in 42%, fair in 25%, and poor in 15%. No radiological abnormalities were detected. Conclusions: Primary bipolar hemiarthroplasty for treating unstable intertrochanteric fractures eliminates the need for prolonged immobilization and permits early ambulation. As reported by others, hip hemiarthroplasty is an effective treatment choice for unstable intertrochanteric femoral fracture in older patients.

An excellent blood-compatible polymer, poly(2-methoxyethyl acrylate) (PMEA), exhibits nanometer-scale phase-separated structures at the interface with water or phosphate-buffered saline (PBS), and fibrinogen adsorption is suppressed, especially on the water-rich region. To understand the correlation between the interfacial structure based on the grafting density of PMEA and blood compatibility, grafted PMEA (gPMEA) surfaces with controlled density were prepared by immobilizing thiol-terminated PMEA on a gold substrate. The amount of adsorbed fibrinogen and the number of adhered platelets on gPMEAs decreased first with the increasing grafting density (σ), but increased after showed minimum at σ of approximately 0.11 chains/nm2. The interfacial structures of the gPMEA/PBS interface changed with grafting density, and the maximum area of water-rich region was obtained at σ = 0.11. The water contact angle at σ = 0.11 is smaller than that at the other grafting density. These results revealed that hydration to the polymer is very effective to suppress the platelet adhesion and water-rich region shows excellent blood compatibility on gPMEA surfaces. This work clearly indicated that the density of PMEA affects the interfacial structure and plays an important role in the blood compatibility of the material.

The surface dynamics of polyhedral oligomeric silsesquioxane (POSS)-functionalized polystyrene (PS-POSS) thin films above the glass transition temperature were studied by grazing-incidence X-ray photon correlation spectroscopy in order to elucidate the effects of POSS at the end of the polystyrene chains. Much slower fluctuations were observed in the surface of PS-POSS thin films than in the polystyrene thin films, despite the negligible difference in their bulk viscosity. Quantitative analysis based on fluctuation-dissipation theorem indicated that there is a high-viscosity layer at the surface of the PS-POSS films, and that the substrate interface originated from POSS segregation.

The practical use of the viscous liquid polymer, poly(2-methoxyethyl acrylate) (PMEA), was expanded from thin films with excellent blood compatibility to thick coatings and free-standing films without essentially sacrificing its blood compatibility. This was undertaken by creating multiple hydrogen-bonding polymer networks by introducing a functional methacrylic monomer bearing a 6-methyl-2-ureido-4[1H]-pyrimidone group in the PMEA backbone via free radical copolymerization. The hydrogen-bonded PMEA (H-PMEA) contained about 6 mol % of the functional monomer in the copolymer. These functional monomers as physical cross-links are distributed in the PMEA matrix with a Tg of −35 °C, making H-PMEA a solid rubber-like material with recoverable tensile strain. Additionally, mechanical tests revealed its tensile strength, and thermogravimetric analyses confirmed its higher thermostability. The dry and hydration states of H-PMEA were assessed by differential scanning calorimetry, contact angle, and atomic force microscopy measurements. Comparison with viscous PMEA was made. For the first time, we included PVC alongside PET, the surface we usually use as a negative control, in the platelet adhesion test with human blood, and found out that 1.5 times more platelets adhered onto the PVC surface than onto the PET surface, while H-PMEA proved to have a clear edge. Thus, H-PMEA may serve as a suitable replacement for polymers in products contacting blood as it shows potential for making free-standing films, thick coatings, implants, and articles with various geometries for the medicinal industry.

We calculate tidal torque due to semi-diurnal thermal tides in rotating hot Jupiters, taking account of the effects of radiative cooling in the envelope and of the planets rotation on the tidal responses. We use a simple Jovian model composed of a nearly isentropic convective core and a thin radiative envelope. To represent the tidal responses of rotating planets, we employ series expansions in terms of spherical harmonic functions $Y_l^m$ with different $l$s for a given $m$. For low forcing frequency, there occurs frequency resonance between the forcing and the $g$- and $r$-modes in the envelope and inertial modes in the core. We find that the resonance enhances the tidal torque, and that the resonance with the $g$- and $r$-modes produces broad peaks and that with the inertial modes very sharp peaks, depending on the magnitude of the non-adiabatic effects associated with the oscillation modes. We also find that the behavior of the tidal torque as a function of the forcing frequency (or period) is different between prograde and retrograde forcing, particularly for long forcing periods because the $r$-modes, which have long periods, exist only on the retrograde side., Comment: 18 pages, 13 figures

Nature-inspired material design concepts and recent progress on anti-fouling polymer materials are reviewed, and our recent researches on anti-fouling studies with polymer brushes are summarized. Zwitterionic polyelectrolyte brush immobilized surfaces represent significant anti-fouling for bio-macromolecules, oil foulants, marine fouling organisms and pipeline foulants. The anti-fouling mechanism was considered on the basis of the wetting, lubrication, hydrated chain dimension and hydrogen-bonding structure of hydrated water in the polyelectrolyte brushes.

Donor-acceptor crosslinked poly[poly(ethylene glycol) methyl ether-methacrylate]-block-poly[1,1'-bis(2-ethylpentyl)-6-methyl-6'-(5-methyl-3-vinylthiophen-2-yl)-[3,3'-biindoline]-2,2'-dione] (poly(PEGMA)m -b-poly(VTIID)n ) nanoparticles with various vinylthiophene donor/isoindigo acceptor ratios are synthesized successfully. The prepared nanoparticles have uniform sizes and well-defined core-shell nanostructures. The intramolecular charge transfer is effectively enhanced due to the incorporation of acceptor groups after the crosslinking reaction. A transistor memory device is assembled using the synthesized polymer and has nonvolatile flash-type memory and amphiphilic trapping behavior. The optimized devices exhibit a significant memory window of approximately 38 V, a retention ability of over 104 s, and an endurance of at least 100 cycles. This study examines multiple applications of crosslinked core-shell nanoparticles, which demonstrates their promise as charge-storage dielectric materials for use in organic memory devices.

The effects of thermal gradient on dynamical behavior of nanoparticles dispersed in polymer matrix were studied by X-ray photon correlation spectroscopy. Anisotropic motions of nanoparticles were observed when the sample was kept in a cell using a capillary tube covered with copper block. As the same experiment using another cell without such thermal gradient clearly demonstrated that even the small thermal gradient around the probe windows caused the anisotropic dynamical behavior.

The performance of a fast pixel array detector with a grid mask resolution enhancer has been demonstrated for X-ray photon correlation spectroscopy experiments., The performance of a fast pixel array detector with a grid mask resolution enhancer has been demonstrated for X-ray photon correlation spectroscopy (XPCS) measurements to investigate fast dynamics on a microscopic scale. A detecting system, in which each pixel of a single-photon-counting pixel array detector, PILATUS, is covered by grid mask apertures, was constructed for XPCS measurements of silica nanoparticles in polymer melts. The experimental results are confirmed to be consistent by comparison with other independent experiments. By applying this method, XPCS measurements can be carried out by customizing the hole size of the grid mask to suit the experimental conditions, such as beam size, detector size and sample-to-detector distance.

Nanoimprint lithography (NIL) is a simple and high-resolution patterning method. Nanoimprinted structures can be fabricated not only as surface structures but also as ‘buried’ structures for applications such as electro-optical devices. However, a precise and nondestructive evaluation method for nanoimprinted structures has not yet been established. Synchrotron radiation ultra-small angle X-ray scattering (SR-USAXS) is a nondestructive and high-resolution characterization method. In this study, we fabricated nanostructures on a poly(lactic acid) (PLA) film using NIL. In addition, the nanoimprinted PLA film was covered with a polystyrene thin film to fabricate a ‘buried’ structure. The fabricated surface and the ‘buried’ structure were evaluated using SR-USAXS. The scattering pattern was clearly obtained from the surface and the ‘buried’ structure. The size of the ‘buried’ structure, which was estimated from the diffraction pattern, was in good agreement with that of the surface structure. These results indicate that SR-USAXS is powerful tool for the nondestructive and precise characterization of surface and ‘buried’ structures. This study demonstrated that synchrotron radiation ultra-small angle X-ray scattering (SR-USAXS) enable us to evaluate the outermost surface and ‘buried’ periodic structure without any pretreatment and sample damage. Surface and ‘buried’ nanostructure were fabricated on poly(lactic acid) film by nanoimprint lithography. The resulting films were characterized by SR-USAXS. The size of surface and ‘buried’ structure were successfully determined by the analysis of scattering pattern.

The interfacial tension γ of the hexane solution of 1H,1H,10H,10H-perfluorodecane-1,10-diol (FC10diol) and 1H,1H,2H,2H-perfluorododecanol (TFC12OH) mixture against water was measured as a function of the total molality m and composition of TFC12OH in the mixture X2 at 298.15 K under atmospheric pressure. The interfacial pressure π vs. mean area per adsorbed molecule A curves and the phase diagram of adsorption (PDA) were constructed in order to shed light on the effect of the molecular orientation on the state of and the miscibility of FC10diol and TFC12OH in the adsorbed film. The π vs. A curves demonstrated that the mixed system exhibits three kinds of film states, parallel-condensed, normal-condensed, and multilayer states, depending on m and X2. The PDA indicated that film composition X2H in the parallel-condensed state never exceeds 0.14 even when X2 is increased to 0.9. This limited miscibility is probably due to a microphase separation that FC10diol and TFC12OH molecules are not dispersed molecularly but the parallel-condensed domains of FC10diol and the normal-condensed domains of TFC12OH are mixed at the interface. In the normal-condensed state, on the other hand, the FC10diol molecules may stand upright and be mixed with TFC12OH molecules. The multilayer is much richer in FC10diol than in TFC12OH when the multilayer is evolved from the parallel-condensed monolayer below X2 = 0.9, while the fraction of TFC12OH increases very rapidly when it is evolved from the normal-condensed monolayer above X2 = 0.925. Below X2 = 0.9, the X2H value in the multilayer is similar to that in the parallel-condensed monolayer. Thus it is plausible that FC10diol molecules are preferentially piled with parallel orientation in the upper layer of the multilayer. Above X2 = 0.925, the multilayer may not be homogeneous but heterogeneous in thickness. These views were confirmed from the X2 dependence of molality mieq of each component at the phase transition points.

The adsorbed film of 1-decyl-3-methylimidazolium bromide (DeMIMB) at the air/water interface was investigated employing the surface tension measurement and the x-ray absorption fine structure method under the total reflection condition (TRXAFS). From the surface tension measurement, the surface excess concentrations of ions were determined. From the XAFS measurement, two solvation states of bromide ion were found in the adsorbed film, which were assigned to be "free-Br" and "bound-Br". The hydration number of the former was estimated to be 6 while that of the latter was estimated to be 4. The results based on the XAFS analysis provided significant information on the formation of domains in the adsorbed film; the most conceivable situation is that the adsorbed molecules are definitely not homogeneously dispersed, but domains (islands or clusters) are dispersed in the adsorbed film. A regular and rather tight stacking of immidazolium rings may be formed in the domains.

The interfacial tensions (y) of the hexane solutions of 1H,1H-perfluorononanol (FDFC 9 OH) and its ω-hydrogenated analogue 1H,1H,9H-perfluorononanol (HDFC 9 OH) against water were measured as a function of temperature and concentration under atmospheric pressure in order to know the effect of ω-dipoles on the adsorption behavior of fluorononanols. The interfacial pressure (n) versus mean area per adsorbed molecule (A) curves consist of two discontinuous changes among three different states: the gaseous, expanded, and condensed states. The A values at given π in the gaseous and expanded states are larger for HDFC 9 OH than for FDFC 9 OH. The changes in partial molar entropy (s H 1 - s O 1 ) and energy (u H 1 - u O 1 ) of adsorption were evaluated. Their values are negative, and therefore, the alcohols have a smaller entropy and energy at the interface than in the bulk solution. Furthermore, the u H 1 - u O 1 value is more negative for HDFC 9 OH than for FDFC 9 OH in the expanded state and also in the condensed film just above the expanded-condensed phase transition point. This seems to be due to the following: (1) HDFC 9 OH may tilt from interface normal for ω-dipoles to interact effectively with water molecules in the interfacial region and to reduce their own repulsive interaction between neighbors arranging parallel in the adsorbed film. This leads to a lower u H 1 value for HDFC 9 OH than for FDFC 9 OH. (2) The contact of ω-dipoles with hexane molecules in the bulk solution is energetically unfavorable, and thus, the u O 1 value of HDFC 9 OH is expected to be larger than that of FDFC 9 -OH.

Peritoneal seeding is frequently detected in patients with gastric cancer. The peritoneal cavity is a compartment in which the immunologic host-tumor interaction can occur. Here, we investigated the gene expression levels of cytokines, and compared these gene expressions with the progression of gastric cancer. Total RNA was extracted from 50 ml of peritoneal washings from 78 patients with gastric cancer and 11 noncancerous patients. The gene expression levels of transforming growth factor-beta (TGF-beta), interleukin (IL)-2, IL-6 and IL-12 were analyzed by real-time reverse transcription-polymerase chain reaction. The gene expression levels of TGF-beta and IL-12 in 16 patients with peritoneal seeding (peritoneal metastasis or free cancer cells) did not differ from those in controls (n = 11) and stage I and II (n = 43) patients. However, the relative gene expression level of IL-2 in patients with peritoneal seeding (0.9) was lower than that in controls (1.4, p = 0.066) and stage I and II patients (1.4, p = 0.036). In contrast, the relative gene expression level of IL-6 in patients with peritoneal seeding (3.3) was higher than that in control (2.4, p = 0.064) and stage I and II patients (2.6, p = 0.065). Low IL-2 gene and high IL-6 gene expressions in the peritoneal cavity may correlate with cancer development in the peritoneal cavity in patients with gastric cancer.

The surface shear viscosity of the liquid expanded phase in Langmuir monolayers of fluorinated alcohols differs by orders of magnitude from the corresponding surface shear viscosity of Langmuir monolayers of their non-fluorinated counterparts. The line tension between the liquid expanded and the gaseous phase on the other hand is of similar magnitude for both fluorinated and non-fluorinated surfactants. The difference of fluorinated versus non-fluorinated monolayers is measured by active microrheology and by observing the shape relaxation of distorted liquid expanded domains toward a circular shape. Our microrheology measurements are supported by measurements of the relaxation rates of distortions, which in fluorinated liquid expanded phases are proportional to the deviation of the curvature from the mean curvature, whereas they are proportional to the square of the deviation of the curvature from the mean curvature in non-fluorinated monolayers.

The adsorption of 1H,1H,10H,10H-perfluorodecane-1,10-diol (FC10diol) at the hexane solution/water interface was investigated by the measurement of interfacial tension gamma as a function of pressure p and concentration m1 and the thermodynamic data analysis. The results obtained were compared with those of 1H,1H,2H,2H-perfluorodecanol (TFC10OH) in order to clarify the effect of molecular orientation on the structure and property of the adsorbed film from the viewpoint of volume change of adsorption. The interfacial pressure pi versus mean area per adsorbed molecule A curve revealed two types of phase transitions among expanded, parallel condensed, and multilayer states. The A value in the condensed state and the transition pressure between the expanded and condensed states were larger for FC10diol than for TFC10OH, which manifests the different molecular orientation that the dispersion interaction between hydrophobic chains is weaker in the parallel orientation of FC10diol than in the perpendicular orientation of TFC10OH. The partial molar volume of FC10diol in the condensed state nu1H.C is slightly larger than that of TFC10OH, although the partial molar volume in the hexane solution is much smaller for FC10diol than for TFC10OH. This supports the view that the fluorocarbon chains of FC10diol remain in their contact with hexane even in the condensed film because of the parallel molecular orientation. The partial molar volume in the nu1H,M was very close to the molar volume of solid FC10diol nu1S and smaller than that of nu1H.C at the condensed-multilayer phase transition, and increased gradually with molecular piling. This substantiates that FC10diol molecules are densely packed in a first few layers just above the phase transition and a little loosely packed in the upper layers of the multilayer with increasing molecular piling. Furthermore, the volume change associated with adsorption from the solid FC10diol Delta(nu)(S) evaluated from the gamma versus p curve under the existence of solid deposit was positive and showed a minimum against concentration for the multilayer state. This is primarily due to the minimum in interfacial density at the solubility limit Gamma1H,S and thus due to the minimum in nu1H,M.

The surface tension of the aqueous solution of 1H,1H,8H,8H-perfluorooctane-1,8-diol (FC(8)diol) was measured as a function of temperature and concentration under atmospheric pressure. The interfacial density and the entropy and energy of adsorption were evaluated and compared to those obtained for the adsorption of 1H,1H,10H,10H-perfluorodecane-1,10-diol (FC(10)diol) at the hexane solution/water interface. The surface tension curves show a break point corresponding to a phase transition of the adsorbed FC(8)diol film. The value of mean area per adsorbed molecule A just below the phase transition indicated the formation of a parallel condensed monolayer, and that above the phase transition suggested the spontaneous formation of a multilayer. The multilayer of FC(8)diol is less compressible and shows a smaller increase in layering with pi compared to FC(10)diol. This is probably because the surface force is repulsive for the hexane/FC/water interface, while it is attractive for the air/FC/water interface. The partial molar entropy change of adsorption is positive in the condensed FC(8)diol film, while it is negative in the condensed FC(10)diol film, which is reasonably explained in terms of the difference in entropy change accompanied by desolvation around the hydrophobic chain. From the viewpoints of the energetic stabilization accompanied by adsorption for the FC(8)diol system, the contribution from the replacement of air/water contact with air/fluorocarbon and fluorocarbon/water contacts and that from the molecular ordering in the adsorbed film is almost equal in case of the condensed monolayer, while in the multilayer the latter is comparatively larger than the former due to the hydrogen bonding between hydroxyl groups and the dispersion interaction among the ordered hydrophobic chains.

The adsorption behavior of 1,1,2,2,-tetrahydroheptadecafluorodecanol (FC10OH), 1-eicosanol (C20OH), and their mixtures at the hexane solution/water interface is summarized briefly and examined from the viewpoints of interfacial tensions in the presence of domains, domain formation, and the correlation between the phase transition and the miscibility of film forming substances in the adsorbed films. The two-dimensional analogue of the Laplace equation showed that the interfacial tension is always higher in the presence of domains than that in the absence of them. The higher tendency of domain formation of FC10OH compared to C20OH is mainly ascribed to the excess Gibbs energy of mixing of fluorocarbon chains and hydrocarbon solvent being positive and to the interaction energy between domains being more stable against cohesion for FC10OH than for C20OH. The thermodynamic equations derived here suggested the heteroazeotropy in the phase diagram of adsorption and the temperature dependence of interfacial tension at the phase transition points, which are in accord with the experimental findings qualitatively.

The interfacial tensions (gamma) of the hexane solutions of 1H,1H-perfluorononanol (FDFC9OH) and its omega-hydrogenated analogue 1H,1H,9H-perfluorononanol (HDFC9OH) against water were measured as a function of temperature and concentration under atmospheric pressure in order to know the effect of omega-dipoles on the adsorption behavior of fluorononanols. The interfacial pressure (pi) versus mean area per adsorbed molecule (A) curves consist of two discontinuous changes among three different states: the gaseous, expanded, and condensed states. The A values at given pi in the gaseous and expanded states are larger for HDFC9OH than for FDFC9OH. The changes in partial molar entropy (s1(H) - s1(O)) and energy (u1(H) - u1(O)) of adsorption were evaluated. Their values are negative, and therefore, the alcohols have a smaller entropy and energy at the interface than in the bulk solution. Furthermore, the u1(H) - u1(O) value is more negative for HDFC9OH than for FDFC9OH in the expanded state and also in the condensed film just above the expanded-condensed phase transition point. This seems to be due to the following: (1) HDFC9OH may tilt from interface normal for omega-dipoles to interact effectively with water molecules in the interfacial region and to reduce their own repulsive interaction between neighbors arranging parallel in the adsorbed film. This leads to a lower value for HDFC9OH than for FDFC9OH. (2) The contact of omega-dipoles with hexane molecules in the bulk solution is energetically unfavorable, and thus, the u1(O) value of HDFC9OH is expected to be larger than that of FDFC9OH.

The Akt signaling pathway controls the survival and growth of human cancers. We investigated the expression of phosphorylated Akt (pAkt) in patients with gastric cancer.The expression of pAkt was immunohistochemically examined in 140 gastric cancer patients who underwent a gastrectomy. The expression of pAkt was evaluated based on staining intensity, and staining was classified as negative or positive. We examined the expression of pAkt and its association with the clinicopathological findings, prognosis, depth of invasion, the expression of p53, and efficacy of oral fluorouracil chemotherapy after surgery.Expression of pAkt was positive in 81 (58%) patients and negative in 59 (42%) patients. There were no significant correlations between pAkt expression and the clinicopathological findings. The prognosis of patients with pAkt-negative tumors was superior to that of patients with pAkt-positive tumors, and the difference was significant for T3/T4 gastric cancer (P0.05). Among the patients with T3/T4 gastric cancer, postoperative oral fluorouracil treatment was effective in those who were pAkt-positive. Multivariate analysis revealed that pAkt expression and lymph node metastasis were independent prognostic factors. In 88 patients with T3 gastric carcinoma who had undergone curative surgery, in whom we studied the prognostic impact of a combined analysis of pAkt and p53 expression, patients with both pAkt- and p53-positive tumors showed a significantly poorer prognosis than patients with either or both pAkt- and p53-negative tumors (P0.05).Our results indicate that pAkt expression may be useful for predicting the prognosis and efficacy of fluorouracil treatment in patients with gastric cancer.

X-ray photon correlation spectroscopy system was setup at SPring-8, BL19LXU, and the partial coherence scattering data from the silica particles grafted with polymer brush in polystyrene matrix were measured. Firstly, the static speckle patterns were checked. Below the glass transition temperature of polystyrene (Tg), speckles were clearly observed, on the other hand, above Tg, the scattering patterns became smooth and speckles were hardly observed. These variances of the speckle patterns result from the particle motion. Secondly, from the time variance of the speckle data, time autocorrelation functions g2(q,t) are calculated. While the flat behaviour of g2(q,t) without relaxation were observed below Tg, the relaxation behavior with relaxation time~100–101 were observed above Tg