Synthesis of Poly(ethylene-block-vinylalcohol)for Use as Amphiphilic Film Surface at High Temperature

Poly (ethylene-block-vinyl alcohol), which consisted of both hydrophobic and hydrophilic blocks, was prepared by using polyethylene single crystals as starting material. Polyethylene single crystals reacted with fuming nitric acid resulting in long methylene chains with functional groups such as COOH and NO(2) at the ends (the chain length were almost same as the lamellar thickness of polyethylene single crystal). The functionalized methylene chains were allowed to react with 4-aminostyrene to give corresponding amides, i.e., methylene chains with vinyl groups at the ends (macromer). The macromers were extended by block-copolymerization with vinyl acetate, then saponified resulting in PE/PVA block co-polymer. The block copolymer was molded into sheets which were subsequently heat-treated in contact with hydrophilic or hydrophobic media. Depending on the media, the sheet surface changed at high temperature reversibly from hydrophilic to hydrophobic and vice versa. The surface property was fixed by quenching because both blocks were able to crystallize. Thus the surface of this material can be tailored for various purposes at high temperature, and then used in stable at room temperature

Scanning Probe Microscopy of Poly(p-phenylene benzobisthiazole) Lamellar Crystal

Rigid polymer, poly(p-phenylene benzobisthiazole), formed lamellar crystals where the molecular chains were oriented perpendicular to the lamellae. It was supposed that, because of wide distribution in the chain length, the lamellar surface bristled with the chain cilia among which many voids were included. Crystallographically, this region afforded us a transitional structure from full to deficient packings of chains. The structure was analyzed using the scanning probe microscope. In the course the method for imaging one molecular chain end was developed. From the images it was concluded that an isolated long cilius did not move so violently at room temperature

Color Image Watermarking Based on Radon Transform and Jordan Decomposition

Digital watermarking has been widely used for ownership identification and copyright protection. In this chapter, a color image watermarking method based on Radon transform (RT) and Jordan decomposition (JD) is proposed. Initially, the host color image is converted into L*a*b* color space. Then, the b* channel is selected and it is divided into 16 × 16 non-overlapping blocks. RT is applied to each of these blocks. JD is applied to the selected RT coefficients of each block represented in m × n matrix. Watermark data is embedded in the coefficients of the similarity transform matrix obtained from JD using a new quantization equation. Experimental results indicate that the proposed method is highly robust against various attacks such as noise addition, cropping, filtering, blurring, rotation, JPEG compression etc. In addition, it provides high quality watermarked images. Moreover, it shows superior performance than the state-of-the-art methods reported recently in terms of imperceptibility and robustness

Synthesis and Characterization of Poly[(benzo[1,2-d:5,4-d']bisthiazole-2,6-diyl)-1,4-phenylene]

Poly[(benzo[1,2-d:5,4-d']bissthiazole-2,6-diyl)-1,4-phenylene](cis-PBZT)with a relatively high molecular weight was prepared by a new synthesis route. Properties of the synthesized polymer, such as thermostability, liquid crystallinity etc. were investigated and compared with those of trans-PBZT. cis-PBZT was crystallized from dilute solution and the electron microscopy showed that the precipitate was a rod-like crystal similar to that of trans form. In spite of rigid nature of the back bone, cis-PBZT showed poor crystallinity

Solution-Grown Crystals of Poly(p-phenylene benzobisthiazole)

Rigid polymer poly(p-phenylene benzobisthiazole) was crystallized from dilute solution. Electron microscopy showed that upon quenching, flat fibrils with several nm thick were produced. Subsequent heat treatment in solvent changed the fibril into "shish-kebab". On the other hand, by isothermal crystallization, an aggregate of parallel rod-like crystals was obtained. The molecular chains were accommodated normal to the rod. Based on the observation of crystal morphology, the isothermal crystallization mechanism was proposed. Because of regidity of polymer chains and wide distribution of the molecular length, the chain ends were inevitably included within the crystals resulting in crystal defects such as axial shift, lattice curvature and edge dislocation which were directly observed by lattice imaging

Immunohistochemical Analysis of Oral Dysplasia: Diagnostic Assessment by Fascin and Podoplanin Expression

The aim of this study was to investigate fascin and podoplanin expression in oral dysplasia and carcinoma in situ (CIS) immunohistochemically, and to evaluate their relationship to histopathological diagnosis based on architectural and cytological features. Fascin and podoplanin expression patterns were analyzed immunohistologically in 26 specimens of oral lesions, including benign disease (hyperplasia, papilloma, and others), intraepithelial neoplasia/borderline disease (dysplasia), and malignant disease (CIS, invasive squamous cell carcinoma). Fascin expression was scored into four original categories, and podoplanin expression was scored into five previously established categories. The relationship between the immunohistochemically determined scores of fascin and podoplanin expression and the architectural and cytological features in the hematoxylin-eosin-stained slides was analyzed statistically. The immunostaining scores for fascin and podoplanin were significantly higher in dysplasia and CIS than in benign disease (p=0.0011, p=0.00036), and they were significantly higher in dysplasia than in benign disease (p=0.0087, p=0.0032). In all cases of invasive SCC, fascin was expressed mainly in the cytoplasm of the tumor cells and fascin expression extended from the destruction of the basal layer of the epithelium to the upper layer of the epithelium and podoplanin was expressed in the cytoplasm and membrane of the tumor cells. This was the first report of up-regulation of fascin in oral dysplasia. Our results suggest that it would be helpful for improving the diagnostic accuracy of oral dysplasia and CIS to assess the expression of fascin and podoplanin immunohistochemically

Recovery of Cryo-injured Rabbit Urethras by Biofabricated C-shaped Adipose-derived Mesenchymal Cell Structures

Article信州医学雑誌 68(6): 357-370(2020)journal articl

Biofabricated Structures Reconstruct Functional Urinary Bladders in Radiation-Injured Rat Bladders

The ability to repair damaged urinary bladders through the application of bone marrow-derived cells is in the earliest stages of development. We investigated the application of bone marrow-derived cells to repair radiation-injured bladders. We used a three-dimensional bioprinting robot system to biofabricate bone marrow-derived cell structures. We then determined if the biofabricated structures could restore the tissues and functions of radiation-injured bladders. The bladders of female 10-week-old Sprague-Dawley (SD) rats were irradiated with 2-Gy once a week for 5 weeks. Adherent and proliferating bone marrow-derived cells harvested from the femurs of male 17-week-old green fluorescence protein-transfected Tg-SD rats were cultured in collagen-coated flasks. Bone marrow-derived cell spheroids were formed in 96-well plates. Three layers of spheroids were assembled by the bioprinter onto a 9x9 microneedle array. The assembled spheroids were perfusion cultured for 7 days, and then the microneedle array was removed. Two weeks after the last radiation treatment, the biofabricated structures were transplanted into an incision on the anterior wall of the bladders (n=10). Control rats received the same surgery but without the biofabricated structures (sham-structure, n=12). At 2 and 4 weeks after surgery, the sham-structure control bladder tissues exhibited disorganized smooth muscle layers, decreased nerve cells, and significant fibrosis with increased presence of fibrosis-marker P4HB-positive cells and hypoxia-marker hypoxia-induced factor 1 (HIF1)-positive cells. The transplanted structures survived within the recipient tissues, and blood vessels extended within them from the recipient tissues. The bone marrow-derived cells in the structures differentiated into smooth muscle cells and formed smooth muscle clusters. The recipient tissues near the transplanted structures had distinct smooth muscle layers and reconstructed nerve cells, and only minimal fibrosis with decreased presence of P4HB- and HIF1-positive cells. At 4 weeks after surgery, the sham-structure control rats exhibited significant urinary frequency symptoms with irregular and short voiding intervals, and low micturition volumes. In contrast, the structure-transplanted rats had regular micturition with longer voiding intervals and higher micturition volumes compared with the control rats. Furthermore, the residual volume of the structure-transplanted rats was lower than for the controls. Therefore, transplantation of biofabricated bone marrow-derived cell structures reconstructed functional bladders.ArticleTISSUE ENGINEERING PART A.24(21-22):1574-1587(2018)journal articl