• Title/Summary/Keyword: Tissue paper

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Regenerative medicine using dental tissue derived induced pluripotent stem cell-biomaterials complex (구강조직유래 유도만능줄기세포-생체재료 복합체의 재생의료 동향)

  • Jun, Soo-Kyung;Lee, Hae-Hyoung;Kim, Hae-Won;Lee, Jung-Hwan
    • The Journal of the Korean dental association
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    • v.55 no.12
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    • pp.828-840
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    • 2017
  • In recent years, many researchers and clinicians found interest in regenerative medicine using induced pluripotent stem cells (iPSCs) with biomaterials due to their pluripotency, which is able to differentiate into any type of cells without human embryo, which of use is ethically controversial. However, there are limitations to make iPSCs from adult somatic cells due to their low stemness and donor site morbidity. Recently, to overcome above drawbacks, dental tissue-derived iPSCs have been highlighted as a type of alternative sources for their high stemness, easy gathering, and their complex (ectomesenchymal) origin, which easily differentiate them to various cell types for nerve, vessel, and other dental tissue regeneration. In other part, utilizing biomaterials for regenerative medicine using cell is recently highlighted because they can modulate cell adhesion, proliferation and (de)differentiation. Therefore, this paper will convey the overview of advantages and drawbacks of dental tissue-derived iPSCs and their future application with biomaterials.

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A Study on the Removal of Fluorescent Whitening Agents from Recycled Fibers

  • Lee, Ji-Young;Lee, Hak-Lae;Youn, Hye-Jung;Lim, Hyung-Woo
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06a
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    • pp.117-121
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    • 2006
  • Virgin bleached kraft pulp, CPO (computer printout) and white ledgers are main raw materials used in tissue mills. The utilization rate of recycled fibers and virgin pulp in South Korea tissue industry are 90% and 10%, respectively. To improve brightness of printing grades the use of 'fluorescent whitening agents (FWAs)' or 'optical brightening agents (OBAs)' has been increased. When recycling these papers for tissue production, it is unavoidable that FWAs contained in recycled papers flow into tissue production lines and remain in the products. And this draws great attention from the public. This study was carried out to develop a technology for the removal of fluorescent whitening agents from recycled fibers. Enzymatic removal of FWAs was evaluated as a method to remove FWAs from the recycled fiber. The ${\alpha}-amylase$ that degrades starched used for surface sizing of fine papers and contained substantial condition is needed to prevent the re-adsorption of FWAs on fibers. The temperature of pulp suspension was another important factor affecting on FWA removal. The higher the temperature, the greater the efficiency of removing FWAs was obtained. Optimum pH and temperature for the effective removal of FWAs were suggested to be pH 8.5 and $65^{\circ}C$, respectively. The enzymatic removal of FWAs showed a great synergistic effect when proper control in pH and temperature was made.

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Component Analysis of Paper Mulberry Bark for the Automation of Bark Peeling Process (닥나무 박피 자동화를 위한 닥 인피의 구성성분 분석)

  • Seo, Jin-Ho;Kim, Hyoung-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.43 no.1
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    • pp.74-82
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    • 2011
  • The bast fiber of Paper mulberry has been generally used as a fibrous raw material in traditional Hanji-making. Nowadays, its uses is expanded to different special purposes such as paper mulberry yarn, laminated paper, antimicrobial paper depending on its application. Despite the wide array of the use of mulberry fibers, it is still limited due to some difficulties in the automation process of manufacturing works. This study is focused on the analysis of chemical components and morphological properties of paper mulberry bark for the automation of bark peeling process. The bast tissue of paper mulberry was separated in three plies; black outer layer, green inner layer, and white inner layer. The total lignin content, holocelluloses, extractives and ashes, and the anatomical structure of the three layers in mulberry bark tissue were investigated. The analysis showed that the black outer layer is composed of about 50% of total lignin content, whereas the white inner layer is composed of about 90% of holocellulose content.

Virtual Environments for Medical Training: Soft tissue modeling (의료용 훈련을 위한 가상현실에 대한 연구)

  • Kim, Jung
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.372-377
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    • 2007
  • For more than 2,500 years, surgical teaching has been based on the so called "see one, do one, teach one" paradigm, in which the surgical trainee learns by operating on patients under close supervision of peers and superiors. However, higher demands on the quality of patient care and rising malpractice costs have made it increasingly risky to train on patients. Minimally invasive surgery, in particular, has made it more difficult for an instructor to demonstrate the required manual skills. It has been recognized that, similar to flight simulators for pilots, virtual reality (VR) based surgical simulators promise a safer and more comprehensive way to train manual skills of medical personnel in general and surgeons in particular. One of the major challenges in the development of VR-based surgical trainers is the real-time and realistic simulation of interactions between surgical instruments and biological tissues. It involves multi-disciplinary research areas including soft tissue mechanical behavior, tool-tissue contact mechanics, computer haptics, computer graphics and robotics integrated into VR-based training systems. The research described in this paper addresses the problem of characterizing soft tissue properties for medical virtual environments. A system to measure in vivo mechanical properties of soft tissues was designed, and eleven sets of animal experiments were performed to measure in vivo and in vitro biomechanical properties of porcine intra-abdominal organs. Viscoelastic tissue parameters were then extracted by matching finite element model predictions with the empirical data. Finally, the tissue parameters were combined with geometric organ models segmented from the Visible Human Dataset and integrated into a minimally invasive surgical simulation system consisting of haptic interface devices and a graphic display.

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Comparison of Vibrational Displacements Generated by Different Types of Surface Source in a Soft Tissue (여러 종류의 표면 진동원에 대한 연조직에서의 진동 변위 비교)

  • Park, Jeong Man;Kwon, Sung-Jae;Jeong, Mok-Kun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.32 no.5
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    • pp.469-483
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    • 2012
  • The propagation characteristics of a mechanical wave in human soft tissue depend on its elastic properties. Investigation of these propagation characteristics is of paramount importance because it may enable us to diagnose cancer or tumor from the vibration response of the tissue. This paper investigates and compares displacement patterns generated in soft tissue due to several forms of low-frequency vibration sources placed on a surface. Among vibration sources considered are a normal load, tangential load, and antiplane shear load. We derive analytical expressions for displacements in viscoelastic single layers, and calculate displacement patterns in half space and infinite plate type tissue. Also, we simulate the vibration response of a finite-sized tissue using finite element method. The effects of the type of stress, the size and frequency of vibration sources, and medium boundaries on displacement patterns are discussed.

MICROSCOPIC OBSERVATIONS OF FAT TRANSLOCATION IN THE TISSUE OF YELLOW CORVENIA DURING SALTING AND DRYING ("굴비" 제조과정중의 지방의 이동에 대한 조직학적 관찰)

  • PYEUN Jae-Hyeung;LEE Eung-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.1 no.2
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    • pp.63-71
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    • 1968
  • Salted and dried yellow corvenia(Pseudosciaena manchurica), so called 'Gul-bi', is one of nation-widely consuming fish foo::ls. It is suitable for a long term preservation and its pro-duce is also a great deal on sea food processing in this country. The texture of 'Gul-bi', however, have often appeared to be a delicate factor for the quality of the product. The loss or dislocation of fat in the tissue of the fish resulted by salting and drying is believed to profoundly relate to the texture of product. In this paper, the tissue of yellow corvenia and movement of fat were microscopically observed before salting, immediately after salting, and after drying and the results observed in the tissues dry salted, brine salted, and brine salted with the addition of BHA were compared. The cross section of yellow corvenia muscle showed that a distinctive border by connective tissue between white and red muscle could not be seen in general, and red muscle was surrounded by hypodermic fatty tissues. In the tissue of fresh yellow corvenia, the fat was mainly distributed in hypodermic fat layer which located under the corium while rarely distributed in white muscle. It was found that some parts of the fat in the tissue were permeated into intermuscular tissue passing through the connective tissues during salting. The result Was the same in both dry-salting and brine-salting tissue. However, the fat translocated into intermuscular tissues disappeared during drying process in the salted without BHA tissues whereas in BHA added tissue. This result suggested that BHA may take a role of multiple effect in translocation of fat in tissues as well as in retarding oxidation. In an advanced stage of salted and dehydration, the muscle fibers were ajoined together and then limits between muscle fibers already became indistinguishable. And the migrated fat into intermuscular tissue aggregated around the connective tissue and are apt to gradually to flow out from the muscular system through these tissues.

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Neutral Deinking of Photocopied Papers with Nonionic Surfactants (비이온 계면활성제를 이용한 복사고지의 중성탈묵)

  • 정영재;이학래
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.33 no.2
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    • pp.58-67
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    • 2001
  • MOW (Mixed Office Waste) mainly consisted of photocopied paper is being recycled to produce tissue or fine paper products. Toner particles that are fused and set on paper surface in photocopying process turns into large and plate-shaped particles after repulping which prevents them to be removed effectively in flotation deinking. The immediate purpose of this study is to find the effective deinking technology that increases the recycling potential of photocopied papers for manufacturing tissue and fine paper products. In this study the effects of pulping temperature and the type of hydrophobic groups of nonionic surfactants on the deinking efficiency of photocopied paper has been investigated. Particle size distribution of the toner particles after pulping and flotation, brightness, yield and ash removal were investigated. The size of toner particles after pulping increased as the pulping temperature was increased. When pulping at the low temperature finer toner particles were generated, however, greater amount of toner particles was found to attach to the fiber. When the pulping temperature was greater than Tg of the toner, the amount of coarse hairy particles increased. When nonionic surfactants with a double bond in hydrophobic groups were used, toner removal efficiency, brightness and ash removal were increased. As the addition level of surfactant was increased, yield decreased rather sharply without improving brightness.

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Enzymatic Deinking of Mixed Office Waste Paper(2) -Paper properties and utilization of DIP- (혼합사무용지의 효소 탈묵(2) -효소처리 혼합사무용지의 물성 및 용도-)

  • Park, Soung-Bae;Yoon, Kyung-Dong;Yoon, Byung-Tae;Eom, Tae-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.37 no.1 s.109
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    • pp.53-60
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    • 2005
  • The mechanical properties of deinked mixed office waste paper in relation to sorts and dosage of enzymes were investigated for successful enzymatic deinking of mixed office waste paper. The increasing of $\Delta$. freeness was most predominant in pulp of Denimax treated pulp. The tensile and burst properties are decreased with enzyme dosage while $\Delta$. freeness were increased. The fine content in disintegrated pulp was decreased with enzyme dosage of $0.4\%$ on the dried weight of paper. The water absorption of handsheets of enzyme deinked pulp was like as that of market roll tissue papers and the mechanical properties of handsheets of enzyme deinked pulp were improved with enzyme treatment comparing of market roll tissue papers.

Development of an Objective Softness Evaluation Method and Its Standardization for Hygiene Paper (위생용지 부드러움의 객관적 평가 방법 개발 및 표준화)

  • Ko, Young Chan;Park, Jong-Moon;Moon, Byoung-Geun
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.5
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    • pp.80-84
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    • 2015
  • Softness is considered one of the most important attributes of hygiene paper such as tissue and towel. Being subjective in nature, however, softness attribute has been generally believed to be impossible to evaluate using objective methods. Hallmark in his pioneering work proposed that tissue subjective softness should be mainly consisted of the bulk softness component and surface softness component. The bulk softness component can be determined by tensile stiffness; the surface softness component by surface tester. The surface friction turns out far more important than the surface roughness in determining the surface softness component. It cannot be too much emphasized that both results of the tensile stiffness and the surface friction should depend on measuring conditions such as an instrument used, sample sizes (e.g., basis weight, length, and width) and operating conditions of the instrument (e.g., gauge length, cross-head speed, size of stylus, and its scanning speed). This indicates that a direct comparison of the test results would be impossible or misleading unless they have been tested under the identical conditions. This may explain why the standard objective test method for tissue softness has not been available at present.

Development of a Multipurpose Cure-appliance Using Microwave (마이크로파를 이용한 다목적 치료기의 개발)

  • 박병욱;정병선
    • Journal of Biomedical Engineering Research
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    • v.10 no.2
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    • pp.179-184
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    • 1989
  • There are microwave hyperthermia, microwave surgical knife, and microwave tissue coagulator etc. as the cure-appliance using microwave. The object of this paper is to develope the multipurpose cure-appliance which has the functions that can be used intestinal tumor as well as the existing superficial tumor. And this also have the function of surgical knife and tissue coagulator with endoscope. And then ascertain its functions through the experiments, and to suggest the direction for reserch hereafter.

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