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    Abstract

    We investigated the effect of light intensity on diurnal differences in secondary wall formation of tracheids. Saplings of Cryptomeria japonica were grown in growth chambers with light intensity cycles set for 12-h high light: 12-h low light by combining two of four light intensity levels: 1.5, 2.8, 4.3, and 10.0 klx. Volumetric changes of differentiating cells were monitored by measuring the tangential strain on the inner bark surface, and the innermost surface of developing secondary walls of differentiating tracheids during the high-light and low-light periods was observed by field-emission scanning electron microscopy. Changes in the aspects of the innermost surface of developing secondary walls and the tangential strain corresponded to changes in the light intensity level. Cellulose microfibrils were clearly observed when the light intensity was high (10.0 or 4.3 klx) and the volume of differentiating cells was low, while abundant amorphous material was observed when the light intensity was lowest (1.5 klx) and the cells were turgid, regardless of the light intensity cycle. These results suggest that the diurnal periodicity in the supply of cell wall components to developing secondary walls is associated with changes in light intensity during the photoperiodic cycle.


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    Abstract

    Treatment of large (diameter 12–25 mm) or giant (diameter >25 mm) cerebral aneurysms with a broad neck in the cranio-cervical area is difficult and carries relatively high risks, even with surgical and/or endovascular methods. To this end, we have been developing a high-performance, self-expanding stent graft which consists of a commercially available NiTi stent (diameter 5 mm, length 20 mm) initially covered with a thin microporous segmented polyurethane membrane fabricated by the dip-coating method. Micropores are then created by the excimer laser ablation technique, and the outer surface is coated with argatroban. There are 2 types of micropore patterns: circular-shaped pore type (pore: diameter 100 μm, opening ratio 12.6%) and the bale-shaped pore type (pore: size 100 × 268 μm, opening ratio 23.6%). This self-expanding stent graft was tested on side-wall aneurysms of both canine carotid arteries that were experimentally induced using the venous pouches from the external jugular veins, with the self-expanding stent graft on one side and a bare self-expanding stent on the other side. All carotid arteries were patent and free of marked stenosis after 1 month. All aneurysms were occluded by stent grafts, while patent in those treated with bare stents. Histologically, the stent grafts with bale-shaped micropores and a high opening ratio were associated with less intimal hyperplasia (187 ± 98 μm) than the bare stents (341 ± 146 μm) or the stent grafts with circular micropores and a low opening ratio (441 ± 129 μm). A pore ratio of 23.6% was found to control intimal growth.


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    Abstract

    We measured the lattice spacing of the cellulose in sugi (Cryptomeria japonica D. Don) and hinoki (Chamaecyparis obtusa Endl.) cell walls under wet and dry conditions. We gave all specimens repeated wet-and-dry treatments and tried to induce substantial changes in the microstructure of the wood cell wall. Macroscopic dimensions, measured using a micrometer, showed well-known behaviors, that is, shrinkage by drying and swelling by wetting, which were unaffected after the repeated wet-and-dry treatments in both longitudinal and tangential directions. On the other hand, lattice spacing, measured using an X-ray diffractometer, showed different results. In particular, d200 lattice spacing expanded considerably with drying in the early stages of repeated wet-and-dry treatments. The d200 lattice spacing in the dried specimen then became gradually smaller in the later stages, whereas no such dynamic change was observed in d004 lattice spacing throughout the repeated wet-and-dry treatments. Once the d200 lattice spacing in the dried specimen had become smaller after giving wet-and-dry treatments, it did not recover, even after soaking in distilled water for 1 month. These results suggest that repeated drying and re-swelling caused structural changes in the wood cell wall, specifically an interfacial separation between cellulose microfibrils and matrix substances.


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    Abstract

    Head-to-head-type styrene and substituted styrene dimers bearing two fluoroalkyl end-groups have been efficiently synthesized by a simple reaction of perfluoroalkyl iodide with styrene under radical conditions as a mixture of meso and racemic forms. The meso form obtained from the mixture by recrystallization gave a crystal suitable for X-ray diffraction study and the crystal structure was found to be based on π-stacking of benzene rings and aggregation of fluoroalkyl chains. Dynamic light scattering measurements showed that meso-styrene dimers bearing two fluoroalkyl end-groups can form the nanometer size-controlled self-assemblies through the intermolecular π-stacking of benzene rings and aggregation of end-capped fluoroalkyl groups in methanol.

    Figure

    Self-assembled meso-perfluorohexylated styrene dimer [C6F13–CH2CHPh–CHPh–CH2–C6F13] based on π-stacking of benzene rings and aggregation of fluoroalkyl chains: Fluorous domains are constructed by self-assembly of fluoroalkyl chains.


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    Abstract

    Background

    Current knowledge in long-term results of tricuspid valve replacement is limited. Present study reviews our experience from a consecutive series.

    Methods

    We retrospectively studied the early and late results of 32 consecutive patients (7 male and 25 female; mean age 60.2 ± 18.1 years) undergoing bioprosthetic tricuspid valve replacement between 1985 and 2010. The etiology is rheumatic in 38 %, congenital in 3 %, endocarditis in 9 %, and functional in 50 %. Patients underwent isolated valve replacement. The remaining underwent combined aortic and tricuspid (n = 5, 16 %), mitral tricuspid (n = 15, 47 %), and aortic, mitral, and tricuspid (n = 1, 3 %) valve replacement. Preoperative liver dysfunction was evaluated using Model for End-stage Liver Disease (MELD) score. Mean follow-up was 5.6 ± 6.8 years (ranging from 0 to 25.0 years).

    Results

    Hospital mortality was 19 %. On univariate logistic regression analysis, NYHA class IV (p = 0.039, odds ratio 11.3, 95 % confidence interval 1.2–112.5), MELD score (>10) (p = 0.011, odds ratio 21.0, 95 % confidence interval 12.0–222.0) and congestive liver (p = 0.05, odds ratio 9.4, 95 % confidence interval 1.0–93.5) were incremental risk factors for hospital death. The 15- and 25-year actuarial survival were 56.5 ± 10.3 % and 45 ± 13.0 %, respectively. Multivariate analysis using Cox proportional hazard model showed MELD score (p = 0.024, hazard ratio 7.0, 95 % confidence interval 2.1–23.9) and postoperative pulmonary hypertension (p = 0.012, hazard ratio 4.4, 95 % confidence interval 1.4–14.1) were significantly associated with decreased survival. At 15 years, freedom rates from tricuspid valve reoperation, anticoagulation-related bleeding, and valve related events were 85.7 ± 13.2 %,95.7 ± 4.3 % and 81.8 ± 13.2 %, respectively. The linearized incidence of structural valve deterioration was 0.50 %/patient-year, anticoagulation-related bleeding was 0.94 %/patient-year, and valve-related events were 1.52 %/patient-year.

    Conclusion

    Preoperative hepatic congestion and liver dysfunction which were indicated by the MELD score >10 were associated with poor outcome for patients undergoing tricuspid valve replacement. The MELD score is useful to predict the morality among these patients.


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    Abstract

    We attempted to measure in situ the tensile elastic moduli of individual component polymers with a three-dimensional (3D) assembly mode in the cell walls of Sugi (Cryptomeria japonica D. Don) without isolating the polymers. To prepare wood tangential slices [50 × 6 × 0.2 mm (L × T × R)] consisting of lignin with a 3D assembly mode in the cell walls, cellulose and hemicellulose were removed using the method of Terashima and Yoshida (2006) to obtain methylated periodate lignin slices. To prepare wood slices consisting of polysaccharide with a 3D assembly mode in the cell walls, lignin was removed using the method of Maekawa and Koshijima (1983) to obtain holocellulose slices. Static tensile test was applied to determine the elastic moduli of 3D lignin and 3D polysaccharide slices. The followings were revealed. The elastic modulus of the 3D lignin slices was 2.8 GPa, regardless of the microfibril angle (MFA) in the slices. The elastic moduli of the 3D polysaccharide slices with MFAs of 14°, 23°, 34°, and 42° were 18, 12, 9, and 4 GPa, respectively. The former shows that the lignin with a 3D assembly mode behaves as an isotropic substance in the cell walls, while the latter suggests that the 3D polysaccharide slice shows marked anisotropic structure in the cell wall. Despite the fact that cellulose content increased after lignin removal, values of substantial elastic modulus of the cell wall slightly decreased regardless of MFA. Following two possible reasons were pointed out for explaining this phenomenon. First, lignin removal caused an artifactual deterioration in the polysaccharide slices at the level of macromolecular aggregate. Second, rigid and fusiform-shaped cellulose crystallites are dispersed in the soft matrix of amorphous polysaccharide, and those are loosely connected to each other by the intermediary of matrix polysaccharide. Those suggest that the rigid cellulose crystallite can optimize its strong mechanical performance in the polysaccharide framework of the wood cell wall in combination with the ligninification.


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    Abstract

    The purpose of this study is to investigate the effect of repeated moisture change on the crystallinity and crystal size of cellulose microfibrils (CMF) in sugi (Cryptomeria japonica D.Don) and karamatsu (Larix kaempferi Gord.) wood cell wall. Based on obtained results, we discussed the qualitative change in the fine structure of CMF caused by repeated dry-and-wet (RDW) treatments. Green quarter-sawn specimens (5 × 16 × 15 mm in thickness × length × width) and microcrystalline cellulose powder (Avicel) were prepared, and these specimens were subjected to 7 times at most of heated or unheated RDW treatments. After giving RDW treatments, specimens were seasoned to the fiber saturated point and absolutely dried. Wide angle X-ray diffraction measurements were adopted to determine the crystallinity and the crystal size in each condition. Results indicate that crystallinity and crystal size in wood specimens gradually increased with the progress of heated or unheated RDW treatments, while no such increases were observed in Avicel powder. Those results suggest that RDW treatments promote the crystallization of CMF in wood cell wall, regardless of heating. We presume that noncrystalline cellulose forms hydrogen bonding with the cellulose at the surface of crystalline region with the progress of RDW treatments, thus enlarging the crystal size. Avicel powder did not show features that were observed in wood specimens by RDW treatments, because it contained few noncrystalline cellulose.


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    Abstract

    Fluoro(silyl)acetylenes, which were prepared by reaction of 1,1-difluoroethylene with silyl chlorides, reacted with triethylamine to give dark-brown colored polyfluoro(silyl)acetylene powders in excellent to moderate isolated yields. In contrast, the corresponding nonfluorinated acetylene was unable to react with triethylamine at all to afford poly(silyl)acetylene under similar conditions. Polyfluoro(silyl)acetylenes thus obtained were nanometer size-controlled cubic fine particles with a good dispersibility and stability in a variety of solvents. These polyfluoro(silyl)acetylene nanoparticles exhibited clear absorption and emission spectra related to the conjugated units in polymer main chain. Furthermore, these polyfluoro(silyl)acetylene nanoparticles were applied to the surface modification of poly(methyl methacrylate) [PMMA] film to exhibit a higher oleophobicity imparted by fluorine on their surface, compared to that on the reverse side.

    Figure

    New polyfluoro(silyl)acetylenes were prepared by reaction of the creesponding fluoro(silyl)acetylenes with triethylamine in excellent to moderate isolated yields. In contrast, the corresponding nonfluorinated silylacetylene was unable to give poly(silyl)acetylene under similar conditions. These polyfluoro(silyl)acetylenes thus obtained can form the nanometer size-controlled cubic fine particles (within 100 nm) in a variety of solvents.


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    Abstract

    We investigated the influences of chemical pretreatments and subsequent repeated dry-and-wet (RDW) treatments on the mechanical linkage between cellulose microfibrils (CMFs) and matrix substances (MT) in wood cell wall. Sugi (Cryptomeria japonica D. Don) quarter-sawn specimens were subjected to various types of chemical pretreatments, including ethanol and benzene extraction, delignification, alkali extraction, and hygrothermal treatment, to give substantial damages to principal constituents of wood cell wall, followed by 5 times of RDW treatment. After giving chemical pretreatment, the d-spacing of (200) lattice plane of cellulose Iβ (d200), the crystallinity of wood cell wall, and the crystal size of the cellulose were measured at the fiber saturated point, using X-ray diffraction techniques. Thereafter, these were measured again at the absolutely dried condition in the process of subsequent RDW treatments. The d200 in specimens, which were given to light pretreatments, largely expanded by drying at the early stages of RDW treatments, then it decreased and became constant after 5 times of RDW treatments. On the other hand, d200 in specimens, which were given to intensive pretreatments, remained constant at a relatively small level throughout the whole process of RDW treatments. After 5 times of RDW treatments, d200 became similar values between the above two groups. This suggests that RDW treatments have similar effects as intensive pretreatments, which induce substantial damages to the microscopic region in the wood cell wall such as interfacial separation between CMF, MT, and so forth. These defects would weaken mechanical interaction between CMF and MT in the wood cell wall during drying.


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    Abstract

    Although sarcoidosis may involve the myocardium, there is little available information on its treatment, especially in cases requiring surgery, such as left ventricular restoration or mitral valve repair. This report presents two surgical cases with cardiac sarcoidosis treated by left ventricular restoration and mitral valve repair for a ventricular aneurysm and dilated cardiomyopathy with mitral regurgitation.


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    Abstract

    We described a 71-year-old female of aneurysm of the left sinus of Valsalva from mycotic origin. She underwent aortic valve replacement 11 years ago. Repeated CT scans showed rapidly growing aneurysm below the left coronary ostium. On sixth day after the admission, she suddenly developed myocardial ischemia complicated with ventricular fibrillation. The patient was treated with emergent aortic root replacement and she recovered. We recommend emergent surgical repair of mycotic saccular aneurysm of the left sinus of Valsalva because a delay of surgery could be fatal.


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    Abstract

    A 58-year-old female presenting with congestive heart failure due to a fistula between an aortic false aneurysm and the superior vena cava (SVC) is described. She had a history of Takayasu’s arteritis (TA) and she had undergone aortic valve and ascending aorta replacement and coronary artery bypass grafting 6 years before. The false aneurysm had occurred 1 year after the surgery, and she had been conservatively managed. The operation revealed that the cause of the false aneurysm was the detachment of the two proximal saphenous vein anastomoses to the ascending aortic graft. After the surgery, the patient made an uneventful recovery. A false aneurysm of the ascending aorta is one of the most serious complications after replacement of the ascending aorta for patients with TA (Miyata et al. in J Vasc Surg 27:438–445, 1998). We herein present the exceptional case of a fistula between an aortic false aneurysm and the SVC that occurred after ascending aorta graft replacement.


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    Abstract

    A wood block often changes its original dimension when it is kept in hot water. This is because the locked-in component of the growth stress is released by hygrothermal softening of the cell wall matrix. However, it is still unknown whether or not heating is a necessary requirement for the release of the visco-elastic locked-in component of the growth stress (GS). To solve this question, Agathis green specimen was treated by drying and re-swelling at room temperature, followed by boiling at 120 °C and 0.2 MPa. Then dimensions of green, re-swollen, and boiled specimens were measured at room temperature. Based on the obtained data, it was discussed whether the drying and subsequent re-swelling treatments release the visco-elastic locked-in component of the GS in green wood. The following conclusions were obtained. Locked-in component is released in part by the drying and subsequent re-swelling treatments without heating. After repeating the drying and subsequent re-swelling treatments, viscoelastic components are gradually released; however, rapid or complete release is made by boiling in hot water.


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    Abstract

    Tension wood, when kiln-dried, is likely to deform hugely, which is probably caused by a gelatinous layer of the gelatinous fiber. To elucidate the mechanism behind the deformation of tension wood during kiln-drying, the strains experienced by tension wood during a hygrothermal treatment that is akin to an early stage of kiln-drying were investigated. Normal wood elongated along the longitudinal axis after the first treatment and leveled off with repetitive treatments. During the first treatment, tension wood contracted significantly along the longitudinal axis, followed by small subsequent contractions, which occurred during successive treatments. This characteristic hygrothermal behavior of tension wood correlated with the areal ratio of the gelatinous layer. One of the possible reasons why tension wood behaves differently was thought to be particular behavior of gelatinous layer. This finding will contribute to the development of appropriate seasoning method for tension wood by clarifying the mechanism behind the deformation of the gelatinous layer.


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    Abstract

    Color changes of four softwood and seven hardwood species during hygrothermal treatment were compared among species and kinetically evaluated. Treatment temperature ranged from 70 to 120 °C, and the durations were 5–150 h. Generally, the \(L^{*}\) (lightness) decreased and the total color differences \((\Delta E_{\text{ab}}^{*})\) increased irrespective of the treatment temperature. \(a^{*}\) and \(b^{*}\) (redness and yellowness) values varied spuriously based on the wood species. Kinetic analysis using the time–temperature superposition principle, which uses the whole data set, was successfully applied to the color changes. The apparent activation energies of the color changes calculated from \(\Delta E_{\text{ab}}^{*}\) were 24.3–40.8 kJ/mol for softwood and 32.3–61.3 kJ/mol for hardwood. The average apparent activation energy for hardwood was higher than for softwood. These values were lower than those calculated from other material properties. The obtained results will contribute to assess the color changes during the early stage of kiln drying and hygrothermal modification of wood.


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    Abstract

    Hygrothermal recovery (HTR), the dimensional changes in wood induced by hygrothermal treatment, was investigated using both compression and normal wood of sugi (Cryptomeria japonica). The elastic released strain of growth stress was measured on living tree surfaces; subsequently, the specimens were taken from the same position to measure HTR. HTR was measured as dimensional changes due to treatment at 20, 40, 60, 80, and 100 °C in hot water ranging from 200 min to 177 days. The intensity of HTR had a positive relationship with elastic released strain of growth stress. This result suggests that HTR is the relaxation of the viscoelastic component of growth stress accumulated during the maturation process of trees. The rate of HTR clearly showed a time–temperature dependency: higher at higher treatment temperatures and lower at lower treatment temperatures. Based on kinetic analysis, the apparent activation energy (Ea) was calculated as 407 kJ/mol, which is similar to the published Ea of lignin softening implying that the HTR is a lignin-related phenomenon.


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    Abstract

    When a green wood specimen is hygrothermally treated, it often shows dimensional changes in the longitudinal and transversal directions, which is called hygrothermal recovery of wood. Hygrothermal recovery of tension wood is assumed to be behind the unusual contraction of gelatinous layer along the longitudinal axis. This study investigated whether hygrothermal recovery of tension wood was temperature-dependent. Hygrothermal treatment at 80, 100 and 120 °C was given to green Quercus serrata tension wood, and longitudinal and tangential dimensions were recorded. In the longitudinal direction, the trend line obtained after 10 times of 10-min hygrothermal treatments at respective temperatures unraveled that it was comprised of initial recovery and continuum contraction at 100 and 120 °C, but no initial recovery was recognized at 80 °C. In the tangential direction, both the initial and the continuum deformations were expansive, and initial recovery was smaller at 80 °C. The results of multiple comparison test revealed that the parameters characterizing the trend line differed significantly among three temperature sets. Further, the result highlighted the existence of breakage of hygrothermal recovery mechanism at temperature between 80 and 100 °C.


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    Abstract

    Preventing falls is one of the clinical problem and causes patients’ significant problem, since it may cause serious injuries such as an abrasion and fractures. An assessment score sheet for inpatients is one of the falls prevention system. In this paper, we focus on sheet for inpatients’ fall risk. In this paper, we validate the appropriateness of the falls estimate in patients hospitalising. We reassessed the score of 84 cases which consist of 42 sets of the actual patient data for patients who have fallen and 42 sets of the data for those who have not from seven wards from October 2013. The results showed four items as greatly influence the falls. With these items, we calculated fall probabilities of each patients, and compared them of patients who have fallen and those who have not. Then, we could not recognise the difference between two groups since the number of people whose probability of fall is more than 60% are 34 cases in patients who fallen and 24 cases who did not fall. From the result of the analysis, we discuss it is not enough that nurses estimate the patient’s fall risk only using the assessment in patients at the time of hospitalising. Instead, the importance of daily assessment is shown.


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    Abstract

    The delayed recovery of the longitudinal length in biomechanically pre-stressed wood, specifically tension wood with a conspicuous gelatinous layer in the cell wall structure, was generally induced by hygrothermal treatment. However, hygrothermal treatment should not be the sole method to induce delayed recovery in tension wood. In order to broaden our understanding of the mechanism underlying delayed recovery, tension wood of Quercus serrata was treated by drying and subsequent rewetting over many times. Interestingly, the longitudinal deformation over repeated drying and subsequent rewetting treatments (dry–wet treatments) was identical to the response of the tension wood during repetitive hygrothermal treatments. Hence, the longitudinal delayed recovery in pre-stressed tension wood was concluded to be induced not only by hygrothermal treatment but also by the dry–wet cycles.


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    Abstract

    To clarify the mechanism of irreversible dimensional changes due to the hygrothermal treatment of green wood, i.e., the hygrothermal recovery (HTR), the changes in vibrational properties of compression wood and normal wood were measured after hygrothermal treatment at 60 °C, 80 °C, and 100 °C. In addition, the relationship between those changes and HTR strains were discussed. The hygrothermal treatment induced an increase in mechanical loss tangent (tanδ) and decrease in specific dynamic Young’s modulus (E). It seems that the changes in vibrational properties due to hygrothermal treatment had a time–temperature dependency: Higher temperatures and longer treatment durations induce larger increases in tanδ and larger decreases in E′/ρ. In contrast to the quenching effect, tanδ and E′/ρ did not recover to their original state even after 60 days of conditioning in water at 20 °C. For compression wood with a large microfibril angle (MFA), there was a clear relationship between the changes in vibrational properties and HTR strains. The tanδ increased and E decreased with hygrothermal treatment, corresponding to dimensional changes in the L-direction. This suggests that structural changes in wood components are responsible for HTR. The most likely mechanism for HTR is that the hygrothermal treatment softens the lignin to release locked-in growth stress. Subsequently, irreversible structural changes in lignin induce both the changes in vibrational properties and HTR. For normal wood, because of the small MFA, the structural changes in lignin in the L-direction are possibly restricted by crystalline cellulose. As a result, the relationship between the changes in vibrational properties and HTR is uncertain.