• Title/Summary/Keyword: Fibrous materials

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Characterizations of Water-dispersed Biocellulose Nanofibers on the Skin Surface (피부 표면에서의 수분산 바이오셀룰로오스 미세섬유의 특성에 대한 연구)

  • Jun, Seung-Hyun;Kim, Seo Yeon;Park, Sun Gyoo;Lee, Cheon Koo;Lee, Seol-Hoon;Kang, Nae-Gyu
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.44 no.1
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    • pp.89-94
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    • 2018
  • In this study, water-dispersed biocellulose nanofibers (TC) were prepared via an oxidation reaction using 2,2,6,6-tetramethyl-1-piperidine-N-oxy radical (TEMPO) as a catalyst. The TC retained their unique structure in water as well as in emulsion. TC adhered to the skin surface while maintaining nanofibrous structures, providing inherent functions of biocellulose, such as high tensile strength and high water-holding capacity. When gelatin gels as model skin were coated with TC, the hardness representing the elasticity was increased by 20% compared to untreated gelatin gel because TC could tightly hold the gelatin structure. When porcine skin was treated with TC and TC-contained O/W emulsion, the initial water contact angles of TC were lower than other materials, and dramatically decreased over time as water penetrated the fibrous structure of the TC film. Characterization of TC on the skin surface offered insight into the function of nanofibers on the skin, which is important for their applications with respect to fiber-cosmetics.

Malignant Transformation of Giant Cell Tumor Not Associated with Radiotherapy (방사선 조사 없이 속발한 거대 세포종의 악성 전환)

  • Lee, Sang-Hoon;Oh, Joo-Han;Yoo, Kwang-Hyun;Suh, Sung-Wook;Ahn, Jun-Hwan;Kim, Han-Soo;Lim, Soo-Taek
    • The Journal of the Korean bone and joint tumor society
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    • v.8 no.1
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    • pp.12-19
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    • 2002
  • Purpose : Giant cell tumors(GCT) sometimes undergo malignant transformation after the radiotherapy, but very rarely do without radiotherapy. We reviewed the clinical experiences of the malignant transformation of GCT to suggest the guidelines for diagnosis and treatment of them. Materials and Methods : We examined four patients of pathologically proven malignant transformation of GCT, which occurred after the operative treatment alone without radiation, from September 1985 to January 2001. The mean follow-up period after the malignant transformation was 2.4 years(range, 1.3~4 years). Results : The mean time-interval from the initial diagnosis to the malignant transformation was 6.9 years(range, 2.2~13.5 years). The locations of tumors were soft tissues of proximal upper arm, proximal femur, distal femur and proximal tibia. The histology of malignant GCT was osteosarcoma in 3 cases and malignant fibrous histiocytoma in 1 case. Local recurrence developed in 1 patient and the pulmonary metastasis developed in 3 patients which transformed to osteosarcoma. Conclusion : Thorough sampling of the surgical specimen appears to be a very important factor for diagnosing the malignant transformation of GCT. In case of suspicion of malignancy in radiographs, the incisional biopsy should be followed by definite treatment rather than the improper resection.

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Role of the periosteum on bone regeneration in rabbit calvarial defects (가토의 두개골 결손부에서 골재생에 끼치는 골막의 역할)

  • Jang, Hyun-Seon;Kim, Sang-Mok;Park, Joo-Cheol;Kim, Byung-Ock
    • Journal of Periodontal and Implant Science
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    • v.35 no.4
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    • pp.939-948
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    • 2005
  • The role of the periosteum on osteointegration of $Bio-Oss^{(R)}$(Geistlich, Wolhusen/Switzerland) was studied in rabbit calvarial defect. 12 New Zealand white male rabbits between 2.8 and 4 kg were included in this randomized, blinded, prospective study. Each rabbit was anesthetized with Ketamine HCl(5 mg/kg) and Xylazine HCl(1.5 ml/kg). An incision was made to the bony cranium and the periosteum was reflected. Using a 6-mm trephine bur(3i. USA), four 8-mm defects were created with copious irrigation. The defects were classified into barrier membrane($Tefgen^{(R)}$, Lifecore Biomedical. Inc, U.S.A.) only group as a control, $Bio-Oss^{(R)}$ with barrier membrane group, $Bio-Oss^{(R)}$ with periosteum covering group, and $Bio-Oss^{(R)}$ without periosteum covering group. There were 2 rabbits in each group. The wound was closed with resorbable suture materials. Rabbits were sacrificed using phentobarbital(100 mg/kg) intravenously at 1, 2, and 4 weeks after surgery. The samples were fixed in 4% paraformaldehyde, and decalcified in hydrochloric acid decalcifying solution(Fisher Scientific, Tustin, CA) at $4^{\circ}C$ for 2-4 weeks. It was embedded in paraffin and cut into 6 ${\mu}m$ thickness. The sections were stained with H & E and observed by optical microscope. The results were as follows; 1. The periosteum played an important role in osteointegration of $Bio-Oss^{(R)}$ in bone defects. 2. When the periosteum remained intact and $Bio-Oss^{(R)}$ was placed on the defect, $Bio-Oss^{(R)}$ with periosteum covering has been incorporated into the newly formed bone from 2-week postoperatively. 3. When the periosteum was removed at the surgical procedure, invasion of connective tissue took place among the granules, and new bone formation was delayed compared to periosteum covering group. Therefore, when the bone grafting was performed with periosteal incision procedure to achieve tension-free suture, the integrity of the overlying periosteum should be maintained to avoid fibrous tissue ingrowth.

Elastofibroma Scapulae (견갑부 탄성섬유종)

  • Kang, Hyun-Guy;Cho, Hwan-Seong;Park, Weon-Seo;Lee, Joo-Hyuk;Kim, Han-Soo
    • The Journal of the Korean bone and joint tumor society
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    • v.12 no.2
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    • pp.118-125
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    • 2006
  • Purpose: We report elastofibroma which is a rare fibrous lesion that most commonly occurs in the between subscapularis and thoracic cage. Materials and Methods: Four patients include one man and three women, the average age was 70 years and the average follow up period was six months. Two patients had on left side, two patients had on both sides. Main symptom was palpable mass. One patient complained mild pain, two complained scapular snapping. Results: All four masses removed with marginal or wide margin. Average mass size was 9.7${\times}$7.2${\times}$3.8 cm. Preoperative symptoms disappeared after surgery. All of the patients have returned to their daily living and showed no recurrence. There was no serious complication such as limitation of shoulder motion and winged scapula. Conclusion: Elastofibroma scapulae can be diagnosed through patient's age, tumor location and radiological finding without preoperative biopsy. When patient is symptomless, observation is enough without surgical operation. Surgical operation considered for relieve of symptoms of pain and snapping.

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Primary bone tumors of fibula (비골에 발생한 원발성 골 종양)

  • Park, Jang-Won;Lee, Seung-Hwan;Shin, Kyoo-Ho
    • The Journal of the Korean bone and joint tumor society
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    • v.12 no.2
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    • pp.112-117
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    • 2006
  • Purpose: The purpose of this study was to investigate on primary bone tumors of fibula. Materials and Methods: Patients who received operative treatment from January 1993 to December 2005 for primary bone tumors of fibula were analyzed for clinical outcomes. Results: There were 17 patients(10 males, 7 females) who were diagnosed for primary bone tumors of fibula. Osteochondroma was the most common diagnosis and others were osteosarcoma, fibrous dysplasia. The malignant bone tumors were 10.5% of all fibula tumors. There were 12 cases on proximal, 4 cases on mid shaft, and 1 cases on distal part of fibula. At the final follow up, 14 patients reported patient satisfaction of either excellent or good. Conclusion: Bone tumor of fibula doesn't need reconstruction after the resection unless it invades tibia or its site distal, which enables easy surgical resection. However, generally it is rare and accompany with vague symptoms, so careful approach to diagnosis is necessary because late diagnosis can mean the needs for amputation.

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Compression Plate Fixation with Autogenous Bone Graft for Humerus Shaft Nonunion (상완골 간부 불유합에 대한 금속판 고정 및 자가골 이식술)

  • Cho, Chul-Hyun;Song, Kwang-Soon;Bae, Ki-Cheor;Kim, In-Kyoo;Kwon, Doo-Hyun
    • Clinics in Shoulder and Elbow
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    • v.12 no.1
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    • pp.33-37
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    • 2009
  • Purpose: To evaluate the results of the compression plate fixation and autogenous bone graft in the management of humerus shaft nonunion. Materials and Methods: Eighteen cases were treated for humerus shaft nonunion using compression plate fixation and an autogenous iliac bone graft. The mean follow-up period was 28 months. Bony union was confirmed from the serial radiographs and the clinical outcomes were assessed according to ASES scoring system. Results: In 12 cases of initial plate fixation, the causes of nonunion were 6 cases of inadequate plate length, 2 with a broken plate, 2 with screw loosening, 1 infection and 1 noncompliance of a psychiatric patient. In 3 cases of initial intramedullary fixation, the cause of nonunion was a distraction of the fracture site. In 3 cases of external fixation, the cause of nonunion was inadequate fixation. All cases showed bony union after an average of 24 weeks. The clinical outcomes were 11 excellent, 6 good and 1 fair. Conclusion: In the treatment for nonunion, compression plate fixation with autogeneous bone graft after complete removal of the fibrous and necrotic tissue is believed to give satisfactory results.

Canine Renal Failure Caused by Ochratoxin A and Citrinin in the Commercial Dog Food (시판 사료에 오염된 Ochratoxin A와 Citrinin에 의한 개의 신부전)

  • Ahn, So-Jeo;Jeoung, Seok-Young;Lim, Man-Su;Park, Son-Il;Han, Jeong-Hee;Kim, Doo
    • Journal of Veterinary Clinics
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    • v.24 no.2
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    • pp.82-87
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    • 2007
  • Five dogs with renal failure were referred to the Veterinary Medical Teaching Hospital at Kangwon National University. These dogs had the common history of consumption of Pedigree dry dog food produced in Thailand plant for over 1 month. The dogs showed anorexia, emaciation, vomiting, and polydipsia/polyuria. And in one severely affected dog, bloody diarrhea and hypothermia were seen. The remarkable clinicopathological signs were high value of BUN and creatinine. In some dogs, GGT, phosphorus and lipase were increased. However, no significant changes of complete blood count were found. In urinalysis, hematuria, low specific gravity urine, proteinuria, and calcium oxalate-like crystals were observed. Two severely affected dogs were died. The remained dogs were recovered gradually after change of dog food and supportive therapy. Pathological findings were seen typically in kidneys. Renal atrophy, congestion of the glomerular capillary, and diffuse degeneration, necrosis, dystrophic calcification and regeneration in the tubular epithelium were seen. Yellowish brown fluorolucent laminated materials or particles were quite often found in the lumina of the necrotizing renal tubules of cortex and medulla. Proliferation of fibrous tissue in the interstitium was also seen. By the mycotoxin analysis of the Pedigree dry dog food, ochratoxin A (OTA) and citrinin were detected as much as the concentration of 372.8 ppb and 8.3 ppb, respectively. The final diagnosis of renal failure caused by OTA and citrinin toxicosis was made on the basis of history takings, clinical signs, clinicopathological and pathological findings, and analysis of mycotoxins.

Ag-Loaded LaSrCoFeO3 Perovskite Nano-Fibrous Web for Effective Soot Oxidation (Ag 담지된 LaSrCoFeO3 섬유상 perovskite 촉매의 탄소 입자상 물질의 산화반응)

  • Lee, Chanmin;Jeon, Yukwon;Hwang, Ho Jung;Ji, Yunseong;Kwon, Ohchan;Jeon, Ok Sung;Shul, Yong-Gun
    • Korean Chemical Engineering Research
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    • v.57 no.4
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    • pp.584-588
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    • 2019
  • The catalytic combustion of particulate matter (PM) is one of the key technologies to meet emission standards of diesel engine system. Therefore, we herein suggest Ag loaded $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3$ perovskite web catalyst. They were produced by the electrospinning method. FE-SEM, EDS mapping, XRD, XPS were studied to investigate the crystal and morphological structures of loaded Ag particles and $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3$ perovskite web catalyst. Following the catalytic soot oxidation, we found that the Ag loaded $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3$ perovskiteweb catalyst showed the higher catalytic activities (e.g., $T_{50}=490^{\circ}C$) than the only $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3$ perovskite web catalyst (e.g., $T_{50}=586^{\circ}C$). Thus, this finding suggests that Ag loaded $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3$ perovskite web catalyst can be a promising candidate for enhancing the soot oxidation.

Manufacturing of Korean Paper(Hanji) with Indian Mallow (Abutilon avicennae Gaertner) as the Alternative Fiber Resources(I) - Productivity and Pulping Characteristics of Indian Mallow - (대용섬유자원으로써 어저귀를 이용한 한지제조(제1보) - 어저귀의 건물 생산량 및 펄프화 특성 -)

  • Jeong, Seon-Hwa;Cho, Nam-Seok;Choi, Tae-Ho
    • Journal of the Korean Wood Science and Technology
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    • v.30 no.2
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    • pp.144-150
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    • 2002
  • Indian mallow is characterized by the rapid growth and high harvest of the fibrous materials. This study was carried out to investigate the sheet properties of Hanji using Indian mallow, made by different pulping methods, such as alkali and sulfomethylated pulpings and different stock compositions, various mixing ratios of bast fiber, woody core and whole stalk fibers. The results from this study were summarized as follows. The length and width of the bast fibers were 1.40-430 mm(av. 235 mm), and 9.2-26.4 ㎛(av.18.3 ㎛), respectively. The cell wall thickness was 4.0-115 ㎛(av. 7.7 ㎛). Runkel ratio, flexibility coefficient and fiber length/fiber width ratio were 1.38, 0.42 and 128 respectively. Bast fiber and whole stalk were cooked by alkali and sulfomethylated methods. Sulfomethylated pulping resulted in superior pulp in terms of yield and quality as compared with those of alkali pulping. The pulp yields of bast fiber was higher than those of whole stalk

Synthesis of Nitrogen-Doped Porous Carbon Fibers Derived from Coffee Waste and Their Electrochemical Application (커피 폐기물 기반의 질소가 포함된 다공성 탄소 섬유의 제조 및 전기화학적 응용)

  • Dong Hyun Kim;Min Sang Kim;Suk Jekal;Jiwon Kim;Ha-Yeong Kim;Yeon-Ryong Chu;Chan-Gyo Kim;Hyung Sub Sim;Chang-Min Yoon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.31 no.1
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    • pp.57-68
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    • 2023
  • In this study, coffee waste was recycled into nitrogen-doped porous carbon fibers as an active material for high-energy EDLC (Electric Double Layer Capacitors). The coffee waste was mixed with polyvinylpyrrolidone and dissolved into dimethylformamide. The mixture was then electrospun to fabricate coffee waste-derived nanofibers (Bare-CWNF), and carbonization process was followed under a nitrogen atmosphere at 900℃. Similar to Bare-CWNF, the as-synthesized carbonized coffee waste-derived nanofibers (Carbonized-CWNF) maintained its fibrous form while preserving the composition of nitrogen. The electrochemical performance was analyzed for carbonized coffee waste (Carbonized-CW)-, carbonized PAN-derived nanofibers (Carbonized-PNF)-, and Carbonized-CWNF-based electrodes in the operating voltage window of -1.0-0.0V, Among the electrodes, Carbonized-CWNF-based electrodes exhibited the highest specific capacitance of 123.8F g-1 at 1A g-1 owing to presence of nitrogen and porous structure. As a result, nitrogen-contained porous carbon fibers synthesized from coffee waste showed excellent electrochemical performance as electrodes for high-energy EDLC. The experimental designed in this study successfully demonstrated the recycling of the coffee waste, one of the plant-based biomass that causes the environmental pollution into high-energy materials, also, attaining the ecofriendliness.