• 한국산업보건학회지
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• 제16권3호
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• pp.193-201
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• 2006

This study was performed to investigate employee exposures to waste anesthetic gases, such as enflurane and sevoflurane in operating rooms of general surgical, children's and dental clinics of a large hospital located in Seoul and to analyze factors affecting the concentrations of waste anesthetic gases. The results of the study are summarized below. 1. Based on results of personal and area samples for airborne enflurane, all of the employees investigated in this study were exposed to airborne enflurane concentrations below the ACGIH-threshold limit value (TLV) of 75 ppm. 2. However, based on results of personal samples for sevoflurane, employees of two (2) out of eleven (11) operating rooms were exposed to sevoflurane concentrations in excess of the NIOSH recommended exposure limit (REL) of 2 ppm. A similar trend was found in the area samples. 3. To investigate the source of sevoflurane emissions, airborne sevoflurane concentrations were measured on an anesthesia machine, a drug cabinet and a desk. It was indicated that the geometric means were 0.93 ppm, 0.83 ppm and 0.72 ppm, respectively. 4. Factors affecting waste anesthetic gas concentrations were the age of anesthesia machine, the volume of operating room and the extent of ventilation (p<0.05). 5. It is recommended that the use of anesthesia equipments be properly controlled, the operating room be well ventilated, and the airborne concentrations of anesthetic gases be continuously monitored.

• 자원리싸이클링
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• 제16권3호
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• pp.3-11
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• 2007

현재 금의 대부분은 금광과 납, 구리 등의 비철금속을 제련하는 공정에서 발생되는 부산물인 양극 슬라임으로부터 제련되고 있다. 뿐만 아니라 금은 사용 후 수거되는 치과 의료용 재료와 폐도금액 그리고 폐인쇄회로기판(폐PCBs) 등의 폐기물로부터 상당량이 제련되고 있다. 금광과 수거되는 고 함량 금함유 폐기물로부터 금을 제련하는 방법에는 크게 염화법, 청화법, 아말감법 등이 있으며, 비철금속 제련공정상의 부산물인 양극 슬라임으로부터 금을 제련하는 방법에는 전기분해법이 있다. 전기분해법은 크게 배소-고온용융-전기분해 공정으로 구성되어 진다. 또한 폐PCBs 같은 저 함량 금함유 폐기물로부터 금을 제련하는 방법에는 주로 건식법이 사용되고 있다. 본 고에서는 금을 제련하는 기술 현황에 대하여 소개하고, 이어서 최근에 국내에서 개발 중인 금제련 기술개발을 간략히 소개하고자 한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제45권6호
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• pp.332-342
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• 2019

Objectives: Socket grafting is vital to prevent bone resorption after tooth extraction. Several techniques to prevent resorption have been described, and various bone graft substitutes have been developed and used with varying success. We conducted this pilot study to evaluate the performance of nanohydroxyapatite (nHA) derived from chicken eggshells in socket preservation. Materials and Methods: This was a prospective, single center, outcome assessor-blinded evaluation of 23 sockets (11 patients) grafted with nHA and covered with platelet-rich fibrin (PRF) membrane as a barrier. Bone width and radiographic bone density were measured using digital radiographs at 1, 12, and 24 weeks post-procedure. Postoperative histomorphometric and micro-computed tomography (CT) evaluation were performed. The study protocol was approved by the Institutional Ethics Committee. Results: All patients had uneventful wound healing without graft material displacement or leaching despite partial exposure of the grafted socket. Tissue re-epithelialized with thick gingival biotype (>3 mm). Width of the bone was maintained and radiographic density increased significantly with a trabecular pattern (73.91% of sockets) within 12 weeks. Histomorphometric analysis showed 56.52% Grade 3 bone formation and micro-CT analysis revealed newly formed bone with interconnecting trabeculae. Conclusion: Use of a PRF membrane with nHA resulted in good bone regeneration in sockets. Use of a PRF membrane prevents periosteal-releasing incisions for primary closure, thereby facilitating the preservation of keratinized mucosa and gingival architecture. This technique, which uses eggshell-derived nHA and PRF membrane from the patient's own blood, is innovative and is free of disease transfer risks. nHA is a promising economic bone graft substitute for bone regeneration and reconstruction because of the abundant availability of eggshell waste as a raw material.

• Biomaterials and Biomechanics in Bioengineering
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• 제4권1호
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• pp.21-32
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• 2019

Eggshell is a waste material after the usage of egg. In this work, biowaste chicken eggshells were used for preparing carbonated hydroxyapatite (HA) nanoparticles of high purity through aqueous precipitation method at room temperature. The eggshell-derived HA will be a cost-effective bioceramics for biomedical applications and an effective material-recycling technology. Additionally, mulberry leaf extract was used as a template to regulate the morphology, size and crystallinity of HA, and the effects of pH value were also examined. Characterization of the samples was performed by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. Scanning electron microscopy (SEM) was used to determine the size, shape and morphology of HA. The results indicate that only one phase of HA were synthesized in the both absence and presence of mulberry leaf extract at pH of 7 and above, while DCPD or DCPA/DCPD phase was observed at pH 4 condition. The crystallite sizes of the HA samples obviously decreased when adding mulberry leaf extract as a template, while they decreased gradually as the solution pH levels increased. With increasing pH level from 7 to 14, the rod-like HA nanoparticles gradually changed to spherical shape at pH 14. Note that, the obtained product is Mg and Sr containing A- and B-type carbonate HA at alkaline pH and it can be a potential material for biomedical applications.

• 치위생과학회지
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• 제13권3호
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• pp.254-263
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• 2013

본 연구는 국내 치과의료기관 감염관리 평가지표를 도출하고 타당성을 검증하고자 하는 연구로서 평가지표의 구성단계, 개발단계, 검증단계로 설계되었으며, 평가지표 구성단계에서 이론적 고찰과 모형의 적용, 평가지표의 개발단계에서 국내 치과병원 감염관리담당자를 대상으로 양적, 질적방법의 예비조사와 관련 전문가를 대상으로 설문조사와 면접조사가 실시되었으며 신뢰도, 안면타당도와 내용타당도검증을 실시하였고 전국의 치과병원 감염관리담당자 121명을 대상으로 감염관리 평가지표 항목에 대한 가중치 조사 및 현장 적용의 문제점을 확인하였다. 평가지표 검증 단계에서는 탐색적 요인분석과 경로분석을 통해 구성타당도를 확인하였다. 이상의 모든 통계적 처리는 PASW Statistics 18.0 프로그램과 AMOS 5.0 프로그램을 이용하였다. 연구의 결과로 국내 치과병원 감염관리 평가지표는 구조, 과정, 결과 영역이 수립되었으며 구조 영역에서 5개 평가요인에서 21개의 세부 평가지표가 도출되었고, 과정 영역에서 8개 평가요인에서 32개의 세부 평가지표가 도출되었으며, 결과 영역에서 1개 평가요인에서 5개의 세부 평가지표가 도출되어, 각 영역에서 총 14개의 평가요인과 58개의 세부 평가지표가 도출되었다. 또한 상관성이 성립되는 8개 평가요인에 대한 경로분석 결과 '표준주의지침($x_1$)', '감염관리지원체계($x_2$)', '내외부적 특성($x_3$)'은 다른 변수들에 영향을 주는 외생관측변수이고 '표준감염관리($y_1$)', '기구 장비관리, 손씻기($y_2$)', '환경감염관리($y_3$)', '개인보호장구($y_4$)', '세탁물 및 폐기물관리($y_5$)' 등은 다른 변수들로부터 영향을 받는 내생관측변수로 작용함을 알 수 있었다. 본 연구에서는 우리나라 치과의료기관 실정에 맞는 감염관리 표준을 위해 평가지표를 개발하고자 하였으며 개발된 치과의료기관 감염관리 평가지표를 통해 국내 치과의료기관 감염관리 체계 활성화 및 감염관리 우선순위 결정에 기여하고자 한다. 향후 치과의료기관 감염관리의 질적 제고를 위하여 감염관리 평가제도 및 인증제도 활성화를 제안하며 향후 지속적인 연구와 관심이 필요하다.

• 한국학교보건학회지
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• 제2권1호
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• pp.91-107
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• 1989

This study was designed to evaluate current level of school health practice in Chonbuk province and to analyze the relationship between school health practice and variables. All the subjects in this study were 140 schools themselves in Chonbuk province. Survey data was collected through the interviewed checklists from the widly accepted school health responsibilities of administration and practice and the direct observation by the interviewer. It was conducted from 1st of Nov. to 17 th of Dec, 1988. The major findings of this study are as follows: A. Level of school health practice was relatively low in score (Mean=64.5). $\cdot$ Healthful School Living -76.14 $\cdot$ School Health Service -71.29 $\cdot$ School Health Instruction -47.98 B. Strengths and Weakness field in School Health Practice. 1. Healthful School Living: Strengths: Waste disposal, Seating, Playground. Weakness: School site, Safety control. 2. School Health Service : Strenths : Health Appraisal, Follow up and Counseling. Weakness: Dental Health, Prevention and Control of Communicable Disease, Facilities and Equipment of Health Clinic. 3. School Health Instruction : Strength : None, Weakness : Program Organization, Curriculum Planning and Evaluation, Curriculum Content, Instructional Aids. C. Significance between degree of School Health Practice and Variables. 1. Healthful School Living : (1) Toilet : Area (p<0.001), No.of Class (p<0.001), School Nurse (p<0.05) (2) Water Supply : School Nurse (p<0.05) (3) Safety Control : School Nurse (p<0.05) 2. School Health Service : (1) Health Appraisal : School Nurse (p<0.05) (2) Follow up and Counseling : School Nurse (p<0.001) (3) Dental Health : Area (p<0.05), Level of School (p<0.05) (4) Prevention and Control of Communicable Disease : Level of School (p<0.001), School Nurse (p<0.05) (5) Emergency Care : Area (p<0.001), No. of Class (p<0.001), School Nurse(p<0.001) (6) Facilities and Equipment of Clinic : Level of School (p<0.001), No.of Class (p<0.001), School Nurse (p<0.001) 3. School Health Instruction: (1) Program Organization : No. of Class (p<0.05), School Nurse (p<0.001) (2) Curriculum Planning land Evaluation : School Nurse (p<0.001) (3) Instructional Aids : Level of School (p<0.001), School Nurse (p<0.05) Recommendation for the Improvement of School Health Practice are as follows : A. There should be further study to strengthen the school health practice, especially in the field of school health instruction. B. It is strictly required to employ and utilize school nurse at each school level not only for the school health service but also for the school health in struction. C. There should be much considerations about adequate size and easily accessible distance in school site.