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BaCO3 and anatase-type TiO2 were adopted as initial materials to prepare BaTiO3 powder by the solid-state reaction method at a heating rate of 350°C/h. The electron paramagnetic resonance (EPR) technique was employed to monitor the formation of BaTiO3. TiO2 showed a series of complicated EPR signals associated primarily with Fe impurities. The formation of BaTiO3 can be monitored in terms of the evolution of EPR signals associated with Fe impurities with calcination and measurement temperatures. The activation of the g = 2.004 signal above the Curie point of BaTiO3 and the disappearance of the other EPR signals in the BaCO3/TiO2 mixture at room temperature are characteristic of the formation of BaTiO3.

Some enzymes catalyze the formation of precipitants of metal ions, and some others directly interact with metal-containing precursors. Such enzymes allow the synthesis of inorganic solids under mild conditions. Due to the nature of enzymatic reactions, enzyme-mediated ceramic synthesis techniques can facilitate (1) site-selective ceramic deposition, (2) low temperature ceramic synthesis, (3) intact combination of ceramics with heat-sensitive materials, and sometimes (4) synthesis of metastable phases. The morphology of the resultant ceramics can be tailored in many ways by immobilizing enzymes onto various templates. So far, successful cases have been reported in preparing thin film coatings, hollow micro- or nanospheres, multi-layer stacking, nanotubes, 2D patterns, honeycombs, 3D replicas of biominerals, and so on. Enzyme-mediated ceramic synthesis provoked the emergence of a new type of processing technique which employs proteins or peptides as the mediators. Practical applications of enzyme- or peptide-mediated ceramics are on the horizon in many fields, such as biomaterials, enzyme immobilization supports, and enzyme sensors. This article presents a comprehensive survey of the recent advances of enzyme-mediated ceramic synthesis and related techniques as well as future outlook.

In this work, two approaches were developed to extend the coating area of diamond by continuous deposition in a plasma-assisted chemical vapor deposition (CVD) method above the liquid. The techniques were based on the methods previously developed by our research group and the characteristic was to use dc (direct current) plasma generated between the liquid surface and the metal electrode. In the first approach, a tungsten rod was rotated in a chamber at reduced pressure so that a diamond film was formed as a ‘belt’ in 6 mm width around the side of the rod. The deposited diamond was polycrystalline with a grain size of 1–3 μm. The film thickness increased almost linearly with deposition time, whereas the grain size was almost constant against the deposition time. The second approach was for a plate substrate. A tungsten plate was hung with an iron wire and the plasma was horizontally generated between the liquid and plate surfaces. When the W plate was vertically slid down slowly, a diamond film was continuously deposited on the surface. The deposited film was covered with a soot-like carbon layer on the top and the post-treatment with H2O/N2 gas at 600 °C was effective in removing it. The continuous deposition successfully demonstrated the expansion of the deposition area with the novel plasma CVD method above the liquid.

We introduce an appropriate class of higher order linear ordinary differential operators with a large parameter and with simple poles in their coefficients, and study their structure from the viewpoint of exact WKB analysis, i.e., the WKB analysis based on the Borel resummation. Our main result is that an operator in the class is expressed as a product of two operators Q and R, with Q being irrelevant to the Stokes geometry and with R being a second order simple-pole type operator studied by Koike ([Ko1], [Ko2], [Ko3]). This decomposition theorem gives us a connection formula for WKB solutions near the simple pole in question, and it is used to explain the background mechanism of some intriguing phenomenon we encounter in the study of a particular third order operator. Some discussions on the scope of the future development of the theory are included.

It was early shown that Ti metal spontaneously bonds to living bone through an apatite layer formed on its surface in the living body, when it was subjected to NaOH and heat treatment to form a sodium titanate on its surface. This kind of bioactive Ti metal was applied to artificial hip joint and already clinically used in Japan. During the study of fabrication process of the hip joint, it was found that sodium content of the surface layer of the Ti metal is largely varied with washing condition after the NaOH treatment, and that apatite-forming ability of the NaOH- and heat-treated Ti metal is liable to decrease in humid environment for a long period. In the present study, the sodium content of the surface layer of the Ti metal was systematically changed by water or HCl treatment after NaOH treatment. Effect of the sodium content of the surface layer on apatite-forming ability in a simulated body fluid and its stability in humid environment of the NaOH- and heat-treated Ti metal were investigated. As a result, it was found that the NaOH- and heat-treated Ti metal gives high and stable apatite-forming ability, when the Ti metal was treated with water after the NaOH treatment to remove partially sodium ions in the surface layer, and subjected to heat treatment.

Titanium (Ti) metal was treated with water or HCl solutions after 5 M NaOH solution treatment and then subjected to heat treatment at 600 degrees C. The apatite-forming abilities of the treated Ti metals were examined in simulated body fluid. The apatite-forming ability of the Ti metal subjected to NaOH, water and heat treatment was lower than that of just NaOH and heat treatments. Ti metals subjected to NaOH, HCl and heat treatment showed apatite-forming abilities, which increased with increasing HCl concentrations up to the same level as that of NaOH- and heat-treated Ti metal. The former did not show a decrease in its apatite-forming ability, even in a humid environment for a long period, whereas the latter decreased its ability. The increase in the apatite-forming ability with increasing HCl concentrations suggests a different mechanism of apatite formation from that previously proposed.

To improve thermoelectric performance of p-type, Ca-Mg-Si alloys were synthesized by mechanical alloying (MA) and/or solid-liquid reaction (SLR). The Ca 16 . 7 Mg 50.0 Si 33.3 ― MA + SLR (synthesized by SLR with milling powder) and the Ca 16.7 Mg 45.5 Si 33.3 Ag 0.5 ― MA + SLR were composed of the phases of Mg 2 Si, CaMgSi and Ca 7 Mg 7 . 25 Si 14 . Their seebeck coefficient α showed positive, and their power factor P values were 0.02 x 10 -3 W·m -1 ·K -2 (670 K) and 0.4 x 10 -3 W·m -1 ·K -2 (730 K) respectively. The Ca 25.0 Mg 25 . 0 Si 50.0 - SLR (synthesized by SLR) was composed of the single Ca 7 Mg 7.25 Si 14 phase, and its α was metallic trend (α ≃ 0) with low electrical resistivity p. It is well-known that Mg 2 Si is n-type semiconductor. These results indicate that the CaMgSi is p-type. Its α was estimated at 750∼900 μV.K -1 (p-type) at 600 K and its p was lower than that of Mg 2 Si above 600 K. The P of CaMgSi single phase is expected more than 1.4 x 10 -3 W·m -1 ·K -2 (600 K). Thus, CaMgSi is attractive material with high thermoelectric performance of p-type.

Hollow hydroxyapatite (HAp) microspheres a few tens micrometers in diameter were fabricated by precipitating HAp preferentially on the surface of an organic polymer template using enzymatically supplied precipitant. The template, polydivinylbenzene (PDVB) microsphere encapsulating urease, was synthesized in W/O/W emulsion. HAp was precipitated on the surface of the template as ammonia was enzymatically supplied from inside of the template in a solution containing calcium ion, phosphate ion and urea. Within 21.6 ks, the surface of the template was covered with HAp. After the template was removed by calcination at 873 K, the HAp hollow microspheres were obtained. The size of the HAp microspheres reflected that of the template and the latter was easily controlled in a range from 10 to 200 μm by the preparation condition of the W/O/W emulsion. The shell thickness of the HAp sphere was also regulated by the duration of the enzymatic reaction. This material can be a promising candidate for the carrier of the drug delivery system.

Controversy still exists about the influence of prosthesis-patient mismatch on outcomes after aortic valve replacement in the elderly. Our aim was to evaluate the effect of prosthesis-patient mismatch on survival and the extent of left ventricular (LV) mass regression after aortic valve replacement for aortic stenosis in Japanese patients agedor=65 years.A total of 84 patients who underwent isolated aortic valve replacement for aortic stenosis between 1986 and 2006 were retrospectively analyzed. Patients were divided into two groups based on the definition of prosthesis-patient mismatch (indexed effective orifice areaor=0.85 cm(2)/m(2)), and long-term results were compared. The mean follow-up time was 4.5 +/- 4.5 years. In 49 patients, follow-up echocardiography was performed at least 6 months after surgery, and the extent of LV mass regression was analyzed according to the presence of a prosthesis-patient mismatch.Eight years after surgery, there was no significant difference between patients with and without mismatch in terms of actuarial freedom from cardiac-related death (P = 0.159) or death from any valve-related events (P = 0.107). The postoperative transvalvular pressure gradients were not significantly different between the two groups, and significant absolute and relative LV mass regression were observed in both groups.Although a moderate prosthesis-patient mismatch appeared to be tolerable, the criteria of prosthesis-patient mismatch may have to be reassessed for elderly Japanese patients.

In order to study method for preparing bioactive titanium metal, calcium ions were attempted to be incorporated into the surface of the titanium metal by ion exchange method. Titanium metal was soaked in 5M NaOH solution and 100mMCaCl2 solution and subjected to heat treatment. About 5 atom% of Na was incorporated into the surface of the titanium metal by the NaOH treatment This Na was completely replaced with calcium ion by the CaCl2 treatment and maintained even after the heat treatment. Critical detaching strength of the surface layer to the substrate of NaOH-treated titanium metal was a little increased by the CaCl2 treatment and remarkably increased by the heat treatment. Apatite-forming ability of the NaOH-treated titanium metal in SBF was increased by the CaCl2 treatment, but decreased by the subsequent heat treatment.

Fatty liver is strongly associated with the metabolic syndrome characterized by obesity, insulin resistance, and type 2 diabetes, but the genetic basis and functional mechanisms linking fatty liver with the metabolic syndrome are largely unknown. The SMXA-5 mouse is one of the SMXA recombinant inbred substrains established from SM/J and A/J strains and is a model for polygenic type 2 diabetes, characterized by moderately impaired glucose tolerance, hyperinsulinemia, and mild obesity. SMXA-5 mice also developed fatty liver, and a high-fat diet markedly worsened this trait, although SM/J and A/J mice are resistant to fatty liver development under a high-fat diet. To dissect loci for fatty liver in the A/J regions of the SMXA-5 genome, we attempted quantitative trait loci (QTLs) analysis in (SM/JxSMXA-5)F2 intercross mice fed a high-fat diet. We mapped a major QTL for relative liver weight and liver lipid content near D12Mit270 on chromosome 12 and designated this QTL Fl1sa. The A/J allele at this locus contributes to the increase in these traits. We confirmed the effect of Fl1sa on lipid accumulation in liver using the A/J-Chr12(SM) consomic strain, which showed significantly less accumulation than A/J mice. This suggests that the SM/J and A/J strains, neither of which develops fatty liver, possess loci causing fatty liver and that the coexistence of these loci causes fatty liver in SMXA-5 mice.

Modification of organic polymer with silanol groups in combination with calcium salts enables the polymer to show bioactivity, that is, the polymer forms apatite on its surface after exposure to body environment. However, how modification with silanol groups influences ability of apatite formation on the polymer substrate and adhesive strength between polymer and apatite is not yet known. In the present study, polyamide containing carboxyl groups was modified with different amounts of silanol groups, and its apatite-forming ability in 1.5SBF, which contained ion concentrations 1.5 times those of simulated body fluid (SBF), was examined. The rate of apatite formation increased with increasing content of silanol groups in the polyamide films. This may be attributed to enhancement of dipole interactions. A tendency for the adhesive strength of the apatite layer on the polyamide film to be decreased with increasing content of silanol groups was observed. This may be attributed to swelling in 1.5SBF and having a high degree of shrinkage after drying. These findings clearly show that modification of organic polymers with the functional groups induces apatite deposition, and also determines the adhesive strength of the apatite layer to the organic substrates.

In some countries, non-point source pollution derived from a city's economic activities tends to be a barrier to the improvement of water quality. Roadway runoff is known to contain toxic micro-pollutants such as polycyclic aromatic hydrocarbons (PAHs). Conversely, red soil is known to adsorb some organic matter. In this study, artificial roadway runoff water containing toxic micro-pollutants was made using roadway dust collected from a highway, and used for both batch-type tests and soil column tests with red soil in order to understand adsorption ability of the red soil on such toxic micro-pollutants, especially PAHs. In the batch-type tests, PAHs could be removed by approximately 40% when the contact time was 90 minutes. In the soil column tests, PAHs were removed by more than 80% while suspended solids were removed by more than 90%. Notably, PAHs with a high molecular weight were removed more readily in the tests than PAHs with a low molecular weight.

We generalize the reduction theorem for 0-parameter solutions of a traditional (i.e., second order) Painleve equation with a large parameter to those of some higher order Painleve equation, that is, each member of the Painleve hierarchies ( P J ) ( J = I , II - 1 or II-2). Thus the scope of applicability of the reduction theorem in [KT1] has been substantially enlarged; only six equations were covered by our previous result, while Theorem 3.2.1 of this paper applies to infinitely many equations.

The aim of this study is evaluate to the cellular viability of elution from the newly developed resin and Osteobond® in vitro. The basis of the newly developed resin are methacryloyloxyethyl methyl succinate and 1,6-Hexanediol dimethacrylate. The basis of Osteobond is methyl methacrylate. The concentrations of basis in each elution were determined by high-performance liquid chromatography (HPLC). Cellular viabilities of L-929 mouse fibroblasts were evaluated by direct cells counting, and then, each IC50 value was calculated. Moreover, patterns of cell death were analyzed using annexin V/propidium iodide staining with the phase-contrast microscope and flow cytometry. The concentration of Osteobond elution was 2.16 mM of MMA, and the newly developed resin elution was 1.02 mM of TA and 1.87 x 10-2 mM of HX. Until 72 hours of incubation, treatment with each elution impaired the viability of L-929 cells in a dose-dependent manner. IC50 value of Osteobond was 6.48 x 10-4 mM of MMA. However, IC50 of the newly developed resin was not calculated. Treatment with Osteobond elution showed more necrotic cells than with the newly developed resin elution. In conclusion, the results demonstrated much more excellent cellular viability of the newly developed resin than that of MMA resin. Thus, it is suggested that the newly developed resin will be more useful as an implantation material for dentistry and orthopaedics.

Bone morphogenetic protein (BMP) is known as a protein that induces new bone in heterotopic sites. This study was conducted to assess the cell-biological effects of crude porcine BMP and 3 pulp-capping materials by implantation and cell culture methods. The following results were obtained: a new bone site of approx 5mm in diameter were induced in the hind limbs, which confirmed the osteoinductive activity of the crude BMP. The pulp-capping materials hardly influenced the calcification of rat dental pulp (RDP) cells. Our data also suggest that the effect of the crude BMP on the proliferation and calcification depended on its quantity. The finding of a large increase in the ALPase activity and the formation of mineralized nodules caused by the crude BMP , suggests that the crude BMP enhanced the calcification by RDP cells. Consequently, it is quite possible that crude porcine BMP could be used as a pulp-capping material.

Apatite formation on polyamide films containing either carboxyl or sulfonic groups was compared in 1.5SBF, whose ion concentrations are 1.5 times those of a simulated body fluid (SBF). The sulfonic groups induced the apatite nucleation earlier than the carboxyl groups. In contrast, the rate of crystal growth depended not on the kind of functional group, but on the degree of supersaturation of the surrounding solution. The more ready association of sulfonic groups with calcium ions may lead to earlier apatite nucleation than that of carboxyl groups. Adhesive strength of the apatite layer to polyamide film containing sulfonic groups was significantly lower than that with carboxyl groups depending on the chemical interactions as well as on the mechanical properties of the polyamide film.

It has been reported that surgical repair of anterior left ventricular (LV) aneurysms is associated with reverse remodeling and improved myocardial function in the inferior LV wall. We evaluated wall motion in RCA territory using QGS in the mid-term period after endoventricular circular patch plasty (EVCPP). Eighteen patients, who underwent EVCPP, were studied by QGS before, and in the early and mid-term periods after surgery. Ten patients underwent CABG to the RCA because of RCA lesions (group B) and the other 8 patients did not have CABG to the RCA (group N). Regional wall thickening function was evaluated by the change in wall thickness through end-systole and end-diastole. We evaluated the RCA territory remote from the incision line of the EVCPP. Regional wall thickness improved significantly in the mid-term period after EVCPP in both groups. Although preoperative wall thickness was worse in group B than in group N, postoperative wall motion in group B was improved as well as in group N in the mid-term period. Inferior LV wall motion improved in patients with and without CABG in the mid-term period. We conclude that reverse remodeling occurred in the mid-term period after EVCPP.

The association constant between guanine and a series of cytosine derivatives in dichloromethane was determined by fluorescence quenching experiment of pyrene connected to guanine with methylene spacer. The association constant for guanine with 5-methylcytosine is found to be higher than that with cytosine. This enables us to distinguish target cytosine from its derivatives.

It is well known that bone morphogenetic protein (BMP) induces bone formation and requires for carriers. Poly-lactic acid / poly-glycolic acid (PLGA) is frequently used as the carriers of BMP. We developed a biodegradable composite PLGA membrane, which was containing oriented needle-like apatite with BMP. The composite membranes were implanted into the thigh muscle pouch of 3-week-old-mice. At 3 weeks after implantation, the implanted area was observed by optical microscopy. The composite membrane containing oriented needle-like apatite with BMP induced new bone formation. It seems that this composite membrane might be a scaffold of BMP and promoting the healing of bone defects.

The adhesion of bovine collagen type I, bovine serum albumin, bovine IgG, 1 % and 10 % (v/v) human serum to hydroxyapatite (HA), silicon-substituted hydroxyapatite (Si-HA) and tissue culture plastic were studied. The materials were incubated at 37 °C for 30 minutes, after which the protein solution was removed and analyzed. The adsorbed protein was evaluated by electrophoresis and immunoassay after extraction from the materials. The degree of adhesion was higher for collagen, followed by IgG and albumin on all materials. However there was no difference in the amount of collagen adsorbed onto the surface of each material and this was also the finding with albumin and IgG. These results suggest that the increased bioactivity seen with Si-HA is not due to the degree of protein adhesion, but may possibly be due to changes in the conformation of the bound proteins.

Hybrids consisting of hydroxyapatite and biodegradable polymers are attractive materials for bone repair. We recently developed hydroxyapatite-alginate hybrids through a soaking process of alginate modified with 3-aminopropyltriethoxysilane (APES), ethylenediamine (EDA) and CaCl2 in a solution mimicking body fluid such as SBF, 1.5SBF proposed by Kokubo et al.. In this study, biological behavior of the apatite-alginate hybrid fabricated through modification with APES and CaCl2 were evaluated after implantation in a rat tibia, in comparison with that of alginate gel without hydroxyapatite. The higher degree of calcification was observed for the hydroxyapatitealginate hybrid than the alginate gel without hydroxyapatite. The hydroxyapatite precipitated on and inside alginate allowed the hybrid to show not only osteoconduction but also suitable biodegradation after implantation in bony defect.

Organic polymer coated with hydroxyapatite (so-called apatite) on its surface is a candidate of new hybrid materials for medical applications since it is expected to show bone-bonding ability and achieve mechanical properties derived from organic substrate. We have shown that some kinds of polyamide films containing carboxyl group or sulfonic group form hydroxyapatite in the simulated body environment, when they are incorporated with calcium chloride. In the present study, the polyamide containing carboxyl groups were modified with silanol groups and its apatite-forming ability was investigated in 1.5SBF, which has ion concentrations 1.5 times those of a simulated body fluid (SBF). It was found that polyamide films modified with silanol groups showed higher ability to induce apatite on its surface in 1.5SBF than the films without the modification, when they were incorporated with calcium chloride.

The purpose of this study was to evaluate the physical properties of the composite membrane before and after soaking in simulated body fluid (SBF) and discuss both degradation and maintenance of their properties. Before and after soaking in SBF, some deposits were found on the preexisted apatite crystals, and Ca and P were mainly detected by energy dispersive X-ray analyzer (EDX). Our results suggest that the composite membrane consisting of apatite and the biodegradable PLGA copolymer would have excellent biocompatibility and maintain adequate physical properties for in vivo use.

Coating organic polymers with hydroxyapatite is an attractive method for the development of materials for medical applications, as it allows hydroxyapatite to show its unique biological properties such as its ability for bone bonding and protein adsorption. The biomimetic process focuses attention on fabricating such hydroxyapatite-polymer hybrids, where bone-like apatite is deposited on an organic polymer surface in solutions mimicking physiological conditions. In this process, a bone-like apatite layer can be coated onto organic substrates either by using a simulated body fluid (SBF), which has ion concentrations nearly equal to those of human extracellular fluid, or by using fluids that are supersaturated with respect to apatite at ambient conditions. We previously reported that apatite was deposited on polyamide films containing carboxyl groups in a solution mimicking body fluid, when they were incorporated with calcium salts. In the present study, to find an alternative functional group effective in apatite formation, we examined the apatite-forming ability of polyamide films containing sulfonic groups in the same solution. It was found that the polyamide film containing sulfonic groups could deposit apatite on its surface in the solution when the film was incorporated with calcium salts. These results show that the sulfonic group also acts as a functional group, and is as effective for apatite deposition in the body environment as the carboxyl group.

The biocompatibility and osteoconductive potential of Bonelikeand Bonelike � /PLGA hybrid materials were evaluated through subcutaneous and tibiae implantations for a 4 week period. Qualitative histology was performed to evaluate new bone formation and characterise bone-implant interface and results showed that Bonelike � /PLGA hybrid materials promote extensive bone growth. After the 4 week implantation period, Bonelikeresorption was recognized, which may be due to the presence of resorbableand �-tricalcium phosphate phases.

To analyze differential operators whose WKB solutions admit infinitely many phases, we introduce a class of differential operators of WKB type and analyze their exact WKB theoretic structure near their turning points. Our analysis makes full use of techniques and ideas in microlocal analysis; we use a quantized contact transformation to construct a WKB solution of a differential equation of WKB type, and we use a Spath-type division theorem for a differential operator of WKB type to study its structure near turning points. As an application, we show a connection formula for WKB solutions near a simple turning point.

Nous introduisons la notion d'operateur microdifferentiel du type BKW et developpons une analyse BKW exacte pour de tels operateurs en utilisant l'analyse microlocale : nous donnons une methode recursive pour construire une solution BKW d'un tel operateur au moyen du calcul symbolique des operateurs microdifferentiels. Nous etudions leur structure locale au voisinage des points de transition par un theoreme de division du type Weierstrass. Nous detaillons l'equation de Berk-Book en appendice.

It is known that a traditional Painleve equation (of the variable t) is obtained by the compatibility condition of a system of second order linear differential equations of the variables x and t. Here, when we focus upon the underlying linear system, the latter variable t is often called a deformation parameter. We can consider, with the appropriate introduction of a large parameter \(\eta \) into these systems, the Stokes geometry for both the linear and non-linear systems in the same way as that described in the previous chapter.

As we have observed so far, virtual turning points and (new) Stokes curves emanating from them play a crucially important role in discussing the Stokes geometry of a higher order ordinary differential equation and/or a system of ordinary differential equations of size greater than two. Once all the non-redundant virtual turning points are provided, then we can explicitly calculate the analytic continuation of solutions of an ordinary differential equation in view of its complete Stokes geometry and connection formulas discussed in Sect. 1.4. Adopting this approach, we consider the non-adiabatic transition problem for three levels and compute transition probabilities of solutions in this chapter. This is a good application of the exact WKB analysis for a higher order ordinary differential equation to a physical problem, illuminating the role of virtual turning points in the calculation of analytic continuation of solutions.

As we mentioned in Preface, global asymptotic analysis of higher order differential equations was thought impossible to construct in 1980s among specialists in asymptotic analysis. In hindsight we find it reasonable, because neither new Stokes curves nor virtual turning points were not in their toolboxes. At that time, physicists H.L. Berk et al. observed in [BNR] that the totality of ordinary Stokes curves was insufficient to describe the Stokes phenomena for WKB solutions of higher order equations and that “new” Stokes curves were needed. Unfortunately it seems that the importance of their observation was not properly appreciated by mathematical specialists in asymptotic analysis as the publication date of the survey article [F] indicates. We believe the reason was that they were not familiar with the Borel transformation depending on parameters, whereas such notion is crucially important in formulating the notion of virtual turning points. Thus we begin our discussion by recalling the core part of “WKB analysis based upon the Borel transformation with parameters” of the Schrodinger equation, a typical second order differential equation. Such analysis is usually referred to as the “exact WKB analysis”; here the adjective “exact” is used in contrast to “asymptotic”.

Objective: The radial artery graft (RA) still involves two unsolved problems, namely, vasospasm and intimal hyperplasia, although satisfactory early and mid-term outcomes have been obtained recently. Methods: Two hundred patients underwent coronary artery bypass surgery with RA between October,1996 and December,2000. We made a comparison of the luminal diameters at early and mid-term periods in 23 patients who underwent mid-term angiographies after a mean follow-up of 27 months. The proximal anastomoses of the RA were the ascending aorta in these patients. The G/N ratio was determined as a ratio of the luminal diameter of the graft to that of the revascularized coronary artery so as to evaluate the luminal discrepancy between the graft and the native artery. Results: In the 122 patients who underwent angiographies about one month after the operation, the patency rate was 99% (144 of 145) in the RA, 97% (139 of 143) in the left internal thoracic artery graft (LITA), 96% (75 of 78) in the saphenous vein graft (SV). In the 23 patients who underwent mid-term angiographies, the patency rate was 91% (24 of 26) in the RA, 100% (23 of 23) in the LITA, and 83% (20 of 24) in the SV. The luminal diameters of the RA and LITA significantly increased from 2.15 to 2.52 mm, and from 1.75 to 1.97 mm, respectively. The luminal change from 3.78 to 3.33 mm in the SV was not significant. The G/N ratios changed from 1.10 to 1.31, from 1.01 to 1.13, and from 2.05 to 1.86 in the RA, LITA, and SV, respectively. The change of the RA alone was statistically significant. Conclusions: The angiographic early patency rate was almost the same in three kinds of graft material, but the mid-term patency rate of the RA was between those of the LITA and SV. The mid-term luminal dilatation of the RA could involve two conflicting characteristics, namely, a good intimal function and a propensity to increase in the luminal discrepancy. Therefore, a further observation is required to evaluate whether the clinical outcome of the RA could remain as good as that of the LITA in the long-term period. q 2002 Elsevier Science B.V. All rights reserved.

The Schrodinger equation idψ/dt = ηHψ with a large parameter η and an appropriate 3×3 matrix H is studied by the exact WKB method, i.e. WKB analysis based on the Borel resummation. Transition probabilities of solutions of the equation are explicitly calculated with the help of the connection formula for WKB solutions. Since a 3×3 system is considered, addition of new Stokes curves is necessary to obtain the correct connection formula (Berk-Nevins-Roberts' observation), and we present a practically useful procedure for finding required new Stokes curves.

In order to determine the region where the Borel sum of a Wentzel–Kramers–Brillouin (WKB) solution ψ of an mth order (m⩾3) ordinary differential equation Pψ=0 with polynomial coefficients is well defined, we apply the steepest descent method to the Laplace integral of a WKB solution ψ of Pψ=0, with P denoting the Laplace transform of P. As a counterpart of the connection formula for ψ, we introduce a new notion of the exact steepest descent path, which is the union of bifurcated steepest descent paths. Both theoretical and computer-assisted experimental studies are given to show the importance of this notion.

Hollow magnetite (Fe3O4) microspheres a few tens micrometers in diameter were fabricated by calcining iron hydroxide precipitated on spherical polydivinylbenzene (PDVB) template with enzymatically supplied ammonia. Monophasic Fe3O4 hollow spheres were obtained by calcining the precursor at 1073 K for 3.6 ks in an equimolar mixed gas of CO2 and H2. The prepared Fe3O4 hollow spheres had smooth surfaces. The particle size and monodispersity of Fe3O4 spheres reflected those of the PDVB template, and the latter was controllable 10-30 μm in diameter during the process of the polymerization. The Fe3O4 spheres showed ferrimagnetic behavior. The use of urease to precipitate the precursor was found to be effective for preparing template-directed microspheres, and the Fe3O4 microspheres synthesized are considered to be promising thermoseeds for hyperthermic treatment.

The patency of coronary artery bypass grafts was evaluated by helical computed tomographic (CT) scan. One hundred forty patients who received an enhanced chest CT scan and a coronary angiography after bypass surgery were studied before discharge at the Fukui Cardiovascular Center. Among them was a total of 398 grafts and 436 anastomoses. For the evaluation of 248 vein grafts, the CT scan showed a 99.5% correct positive ratio and an overall accuracy of 96.4%. In 122 internal thoracic arteries tested, an overall accuracy of 64.7% was obtained. In gastroepiploic artery tests the overall accuracy was 33.3% and in radial artery tests it was 45.5%. Thirty-seven venous sequential anastomoses in 34 grafts and 1 internal thoracic artery sequential anastomosis were also evaluated. In the venous sequential anastomosis, the CT scan showed a 73.0% of accuracy overall. This study showed that the helical CT scan was useful to evaluate graft patency following bypass surgery. Cathet. Cardiovasc. Intervent. 46:322–326, 1999. © 1999 Wiley-Liss, Inc.

6-Hydroxynicotinate 3-monooxygenase, a membrane-bound, 42-kDa monomeric enzyme from Pseudomonas fluorescens TN5 was purified and characterized. The enzyme catalyzes the oxidative decarboxylation of 6-hydroxynicotinate and depends on O2, NADH and FAD with the holoenzyme containing 1 M of FAD per 1 M of enzyme. The isolated enzyme was used for the synthesis of 2,5-dihydroxypyridine, a precursor for the chemical synthesis of 5-aminolevulinic acid, which is applied as a plant growth hormone, a herbicide and in cancer therapy. A 1.8-kbp DNA fragment, which contains the ORF encoding 6-hydroxynicotinic acid 3-monooxygenase, was cloned, sequenced and expressed in Escherichia coli. The deduced 385 amino acid sequence of the cloned ORF is in agreement with the enzyme molecular mass, amino acid sequence of an internal peptide, contains a putative FAD-binding site and is homologous to similar flavoproteins such as salicylate 1-monoxygenase.