• 제목/요약/키워드: Fiber chain

검색결과 199건 처리시간 0.024초

부인강에서 발생한 설하신경의 신경초종 1례 (A Case of Parapharyngeal Neurilemmoma Arising from Hypoglossal Nerve)

  • 이성욱;은상용;박성준;이상훈
    • 대한두경부종양학회지
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    • 제16권1호
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    • pp.69-72
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    • 2000
  • The neurilemmoma is a relatively uncommon benign neoplasm which is known to be originated from the schwann sheath of the nerve fiber. Parapharyngeal neurilemmomas may originate from any nerve traversing this space, but the vast majority arise from the vagus nerve and sympathetic chain. The neurilemmomas arising from the extracranial portion of the hypoglossal nerve are extremely rare. To our knowledge, the case we present is the ninth one to be reported occurring in the parapharyngeal space. Recently we experienced a case of parapharyngeal neurilemmoma arising from the hypoglossal nerve and so we report our case with a brief review of literatures.

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Ethoxylated Hexylaminoanthraquinone에 의한 나일론의 내구성 대전방지가공 및 친수화 가공 (Durable Antistatic and Hydrophillic Finishing of Nylon Using Ethoxylated Hexylaminoanthraquinones)

  • 김명순;박현민;윤남식
    • 한국염색가공학회지
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    • 제17권2호
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    • pp.26-30
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    • 2005
  • Nylon fabric is widely used in stocking, inner wear, sports wear, and casual wear, but has a defect of easy electric static charging. Accordingly there has been great demand for the hydrophillic finishing technology that could be applied to nylon fiber more easily and efficiently. In this study, ethoxylated hexylantinoanthraquinones were exhausted onto nylon from aqueous bath, and hydrophillicity of the nylon was discussed. In the treatment of nylon fabrics with ethoxylated hexylaminoanthraquinones, they were successfully exhausted onto nylon fabric without any aid of chemical auxiliary. The hydrophilicity of the dyed nylon fabrics were increased with the length of ethoxylate chain. The durability of antistatic and hydrophilic characteristics was good enough as to maintain the initial properties even after 30 repeated launderings.

In Vitro Effects of Dietary Inulin on Human Fecal Microbiota and Butyrate Production

  • Jung, Tae-Hwan;Jeon, Woo-Min;Han, Kyoung-Sik
    • Journal of Microbiology and Biotechnology
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    • 제25권9호
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    • pp.1555-1558
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    • 2015
  • Administration of dietary fibers has various health benefits, mainly by increasing numbers of beneficial bacteria and enhancing production of short-chain fatty acids in the colon. There has been growing interest in the addition of dietary fiber to human diet, due to its prebiotic effects. This study aimed to evaluate the prebiotic activity of inulin using an in vitro batch fermentation system with human fecal microbiota. Fermentation of inulin resulted in a significantly greater ratio of Lactobacillus or Bifidobacteria to Enterobacteria strains as an index of healthy human intestine and elevated butyrate concentration, which are related to improvement of gut health.

Phase Transformation of Poly(trimethylene terephthalate) in Crystalline State: An Atomistic Modeling Approach

  • Jang, Seung-Soon;Jo, Won-Ho
    • Fibers and Polymers
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    • 제1권1호
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    • pp.18-24
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    • 2000
  • The phase transformation of poly(trimethylene terephthalate) in crystalline state was simulated by atomistic modeling using molecular mechanics technique. The crystalline structure of PTT was successfully prepared using the well-defined unit cell structure of PTT and was satisfactorily verified by comparing that with the structure obtained from the x-ray diffraction experiments. The basic elastic properties were predicted in this study, showing that the crystalline structure of PTT is very pliable to the deformation at small strain. When the crystalline structure of PTT was stepwise deformed up to 50% of strain in chain direction under uniaxial extension condition, the change in dihedral angle of trimethylene unit from gg to tt conformation was accompanied with a large increase of stress, indicating that the phase transformation of PTT in crystalline state is difficult to occur.

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Living cationic polymerization of Viny Ethers in Presence of Iodomethyl Methyl Ether and Zinc Iodide

  • Kwon, Soonhong;Lee, Yunsung;Mah, Soukil
    • Fibers and Polymers
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    • 제2권1호
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    • pp.131-134
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    • 2001
  • Living cationic polymerization behaviors of isobutyl vinyl ehters (IBVE), initiated by iodomethyl methyl ether (IMME)/zinc iodide ($Znl_2$) have been investigated. The polymerization was carried out at 0, -15, and $-30^{\circ}C$ in toluene. It was found that the rate of polymerization increased as the IMME concentration increased and decreased as temperature decreased. 100% conversion was always achieved without exception. Furthermore, the number-average molecular weight ($M_{n}$) of polymers increased in direct proportion to monomer conversion. The molecular weights of polymers were in good agreement with the theoretical values, calculated on the basis that one polymer chain was formed by one IMME molecule and the values of polydispersity index are always less than 1.2, revealing the living nature. The living nature was also confirmed by synthesis of poly(IBVE-b-TBVE) by subsequent monomer addition of t-butyl vinyl ether (TBVE).

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Photoisomerization and Photo-induced Optical Anisotropy of Polymethacrylate Containing Aminonitroazobenzene

  • Park, Dong-Hoon;Cho, Kang-Jin
    • Fibers and Polymers
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    • 제2권1호
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    • pp.123-130
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    • 2001
  • Photoresponsive side chain copolymer and homopolymer containing an aminonitroazobenzene were synthesized for studying photoisomerization behavior and photo-induced anisotropy. Trans-to-cis photoisomerization was observed under the exposure of a circularly polarized visible light with UV-Vis absorption spectroscopy. Reorientation of polar azobenzene molecules induced optical anisotropy under a linearly polarized light at 532nm. Polarized absorption spectroscopy was employed to investigate the anisotropy of the polymer film during irradiationg of the excitation light. Layers of two photosensitive polymers were used for aligning liquid crystal(LC) molecules instead of one of the rubbed polyimide layers in the conventional twisted nematic cell. For producing homogeneous alignment of a nematic LC molecule, a linearly polarized light was exposed to the films of two polymers. The stability of the LC alignment upon the linearly polarized light exposure was also studied.

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Synthesis and Characterization of Copolyester Sizing Agents

  • Baik, Doo-Hyun;Kim, Gil-Lae
    • Fibers and Polymers
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    • 제2권1호
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    • pp.148-151
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    • 2001
  • The effect of main chain structure of anion-containing copolyesters on the properties of copolyester sizing agents was investigated. The copolyesters were prepared by conventional two step polymerization technique from DMT, DMI, DMS, EG, and DEG. The copolyesters synthesized were characterized by atomic absorption spectroscopy, $^1$H-NMR Spectroscopy, GC, FTIR Spectroscopy, and DSC. The solubility decreased as the DMT content increased. The copolyesters having DMT:DMI = 1:1 showed the minimum viscosity. The effect of EG content on the solution stability was not clear and the samples having high DMI content showed better solution stability. The water resistance was best when only DMI and EG were used, while it was worst when DMT:DMI was 1:0.

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Epoxidized Polybutadiene as a Thermal Stabilizer for Poly(3-hydroxybutyrate). II. Thermal Stabilization of Poly(3-hydroxybutyrate) by Epoxidized Polybutadiene

  • Choi, Ju-Yol;Lee, Jong-Keun;You, Young;Park, Won-Ho
    • Fibers and Polymers
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    • 제4권4호
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    • pp.195-198
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    • 2003
  • Epoxidized polybutadiene (EPB) was prepared by polybutadiene (PB) with m-chloroperbenzoic acid (MCPBA) in homogeneous solution. EPB was blended with poly(3-hydroxybutyrate) (PHB) up to 30 wt% by solution-precipitation procedure. The thermal decomposition of PHB/EPB blends was studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and differential thermal analysis (DTA). The thermograms of PHB/EPB blends contained a two-step degradation process, while that of pure PHB sample exhibited only one-step degradation process. This degradation behavior of PHB/EPB blends, which have a higher thermal stability as measured by maximum decomposition temperature and residual weight, is probably due to crosslinking reactions of the epoxide groups in the EPB component with the carboxyl chain ends of PHB fragments during the degradation process, and the occurrence of such reactions can be assigned to the exothermic peaks in their DTA thermograms.

퍼머넌트 셋팅 후 탈색조건에 따른 모발의 손상 (Damage of Hair according to the Bleaching Condition after Permanent Setting)

  • 임순녀;최창남
    • 한국염색가공학회지
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    • 제24권1호
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    • pp.27-32
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    • 2012
  • Generally, hair treatments by complementary actions to give a sense of activity are permanent setting, dyeing, and bleaching, etc. In this study, we investigated the wave formation ability and hair damage occuring in permanent setting and bleaching process. The wave formation ability was evaluated by the differences of length and curl diameter after permanent setting. And the hair damage was also evaluated by the protein release ability and SEM of hair. The bleached hair immediately after permanent setting treatment has better wave formation ability, but much more damaged than the bleached hair after rinsing thoroughly with warm water. It was considered that the chain of hair keratin broke down easily by the bleaching action in the existence of permanent setting agents.

대장암에 대한 butyrate의 효과 (Effects of Butyrate on Colorectal Cancer)

  • 진지영;조광근;최인순
    • 생명과학회지
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    • 제23권1호
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    • pp.143-156
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    • 2013
  • 현재 우리나라는 높은 암 발생률과 사망률로 인해 암에 대한 관심과 심리적 불안감이 높아지고 있고, 따라서 많은 연구가 진행되고 있는 실정이다. 그럼에도 불구하고 암 발생률 빈도는 현저하게 증가하고 있는 추세이며, 그 중에서도 발병률이 높은 대장암은 발견 또한 늦어 사망률이 높다. 따라서 대장암의 예방이 무엇보다도 시급하다. 원인은 아주 다양하면서도 정확하게 규명되진 않았지만, 가장 크게 식생활의 서구화로 인한 결과로 여겨진다. 육류 위주의 서구식 식이습관 개선을 위해 식이섬유를 풍부하게 섭취하게 되면 항암제 역할을 하는 단쇄지방산인 butyrate가 위장관 내에서 장내 미생물에 의해 발생된다. 암의 치료에 있어서 항암제들은 종양세포의 apoptosis를 유도한다는 것이 알려졌고, 종양세포의 apoptosis 기전과 암의 치유기전 사이에는 서로 깊은 연관이 있음이 확인되었다. 따라서 butyrate가 직접적으로 대장암 세포의 apoptosis를 일으킴으로써 대장암을 억제하는 효과를 연구결과들을 통해서 확인하였고, 이는 대장암의 예방 및 치료에 직접적으로 영향을 미칠 것을 기대한다.