372 research outputs found

    Crystallization of Polymers from Solution under ShearingStress III Polybutene-1

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    It was shown that the fibrous crystals of isotactic polybutene-l crystallized from solution under shearing stress are also composed of the central threads with an extended chain character and the epitaxally deposited lamellae with a folded chain character. The characteristic behaviors in this polymer exist in; (1) that the resulting crystals possess the hexagonal modification of form 1'; (2) that at low polymer concentrations the lamellar crystals with an orthorhombic modification of form Ⅲ are precipitated in similar fashion to the case in the absence of stirring; (3) that the morphology in surface replica of thick deposited film is very similar to that of melt extruded polyethylene film crystallized in a highly stressed state

    Strategies to enhance the excitation energy-transfer efficiency in a light-harvesting system using the intra-molecular charge transfer character of carotenoids

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    Fucoxanthin is a carotenoid that is mainly found in light-harvesting complexes from brown algae and diatoms. Due to the presence of a carbonyl group attached to polyene chains in polar environments, excitation produces an excited intra-molecular charge transfer. This intra-molecular charge transfer state plays a key role in the highly efficient (∼95%) energy-transfer from fucoxanthin to chlorophyll a in the light-harvesting complexes from brown algae. In purple bacterial light-harvesting systems the efficiency of excitation energy-transfer from carotenoids to bacteriochlorophylls depends on the extent of conjugation of the carotenoids. In this study we were successful, for the first time, in incorporating fucoxanthin into a light-harvesting complex 1 from the purple photosynthetic bacterium, Rhodospirillum rubrum G9+ (a carotenoidless strain). Femtosecond pump-probe spectroscopy was applied to this reconstituted light-harvesting complex in order to determine the efficiency of excitation energy-transfer from fucoxanthin to bacteriochlorophyll a when they are bound to the light-harvesting 1 apo-proteins

    Pathological complete response of advanced gastric cancer with pyloric stenosis to neoadjuvant S-1/CDDP chemotherapy: A case report

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    A 59-year-old man with epigastric discomfort and anorexia was referred to our hospital. Endoscopy revealed a type 3 advanced gastric cancer with pyloric stenosis diagnosed as a poorly differentiated adenocarcinoma in the biopsy specimens. A gastrojejunal bypass operation was performed because of direct invasion to the pancreas. The patient was treated by three courses of neoadjuvant chemotherapy with S-1/CDDP. Follow-up abdominal CT scan revealed that the primary tumor had become smaller, suggesting that a partial response had been achieved. Distal gastrectomy with D2 lymphadenectomy was performed. The histopathological examination showed no residual cancer cells in the primary lesion or dissected lymph nodes. Final chemotherapy efficacy was evaluated as Grade 3. The patient was treated with S-1 for one year after the gastrectomy and lymphadenectomy and has been followed up for 18 months without evidence of recurrence

    Vision evaluation by functional observational battery, operant behavior test, and light/dark box test in retinal dystrophic RCS rats versus normal rats

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    BACKGROUND: Vision plays a key role in some behavior tests for rats. Okayama University-type retinal prosthesis (OUReP) is a photoelectric dye-coupled polyethylene film which generates electric potential in response to light and stimulates nearby neurons. This study aims to assess vision in retinal dystrophic (RCS) rats, in comparison with normal rats, by selected behavior tests. We also examined whether the tests could detect vision changes in RCS rats with dye-coupled film implantation. METHODS: Data sets were 5 normal rats, 4 untreated RCS rats, 7 RCS rats with dye-coupled films implanted at the age of 7 weeks after excluding unsuccessful implantation at autopsy. Behavior tests chosen were landing foot splay and visual forelimb-placing response in the menu of functional observational battery, operant-conditioning lever-press response and light/dark box test. RESULTS: Normal visual placing response was significantly less frequent in untreated RCS rats at the age of 9 and 11 weeks, compared with normal rats (P = 0.0027, chi-square test) while normal response was significantly more frequent at the age of 9 weeks in RCS rats with dye-coupled film implantation, compared with untreated RCS rats (P = 0.0221). In operant-conditioning lever-press test, the correct response rate was significantly lower in untreated RCS rats than in normal rats at the age of 9 weeks (P CONCLUSIONS: Behavior tests of functional observational battery, operant-conditioning lever-press response and light/dark box test discriminated vision between normal rats and RCS rats. The visual placing response and operant-conditioning lever-press test might have sensitivity to detect vision recovery in RCS rats with OUReP implantation

    Specific gene expression in unmyelinated dorsal root ganglion neurons in nonhuman primates by intra-nerve injection of AAV 6 vector

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    霊長類においてウイルスベクターを用いた痛覚神経への遺伝子導入に成功 --神経障害性疼痛治療への応用に期待--. 京都大学プレスリリース. 2021-08-12.Adeno-associated virus 6 has been proposed as a potential vector candidate for specific gene expression in pain-related dorsal root ganglion neurons, but this has not been confirmed in nonhuman primates. The aim of our study was to analyze the transduction efficiency and target specificity of this viral vector in the common marmoset by comparing with those in the rat. When green fluorescent protein-expressing serotype-6 vector was injected into the sciatic nerve, the efficiency of gene expression in dorsal root ganglion neurons was comparable in both species. We found that the serotype-6 vector was largely specific to the pain-related ganglion neurons in the marmoset as well as in the rat, whereas the serotype-9 vector resulted in contrasting effects in the two species. Neither AAV6 nor AAV9 resulted in DRG toxicity when administered via the sciatic nerve, suggesting this as a safer route of sensory nerve transduction than the currently used intrathecal or intravenous administrative routes. Furthermore, the adeno-associated virus 6 vector could be an optimal serotype for gene therapy for human chronic pain that has minimal effect on other somatosensory functions of dorsal root ganglion neurons
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