수열합성법을 이용한 향균성 TiO_(2) 나노입자의 제조와 특성

김강혁,이우진,이상화,김인수 東亞大學交附設 生産技術硏究所 2005 生産技術硏究所硏究論文集 Vol.10 No.-

TiO_(2) particles in range of 10-30nm were successfully synthesized through a hydrothermal process. The conditions for manufacturing TiO_(2) particles were investigated in terms of precipitation pH, reaction period, Zetapotential etc. and synthesized particles were characterized by XRD, DSC, UV-Visible spectra. The photocatalytic efficiencies decrease with content of Agdoped to TiO_(2). Thus, it is concluded that 0.5 wt% Ag content is the most suitable in view of photocatalytic and antibacterial properties.

실내 사육실에서 늦반딧불이의 성충 수명

김강혁,정재훈 한국응용곤충학회 2017 한국응용곤충학회 학술대회논문집 Vol.2017 No.04

무주군에서 2014년 6~7월 사이에 채집한 늦반딧불이 유충을 실내에서 사육하여 생물적 특성을 조사하였다. 사육실의 조건은 온도를 23℃, 습도는 75%, 광주기는 14L:10D로 하였다. 유충은 곳체다슬기(Semisulcospira gottschei)를 먹이로 하여 번데기가 되기 전까지의 유충 기간을 사육하였다. 늦반딧불이의 전용 기간, 번데기 기간, 성충 기간과 산란수를 조사한 결과 암컷의 전용 기간은 4.3일, 번데기 기간은 9.7일, 암컷 성충 기간은 10.7일이었고, 수컷의 전용 기간은 5.2일, 번데기 기간은 11.5일, 성충 기간은 22.1일이었다. 또한 산란 전기간은 5.3일, 산란 기간은 4.5일이었 고, 암컷의 산란수는 65.3개 였다. 일별 산란은 최초 산란 후 2일까지 산란수가 전체 산란수의 약 75%를 차지하였다.

혀에 발생한 선천 흑색증성 모반 -증례보고-

김강혁,조정우,정승환,김진수,박재억,김창현 대한구강악안면병리학회 2016 대한구강악안면병리학회지 Vol.40 No.5

Oral hyperpigmentation is common in patients older 40 years. But lesions in a newborn are unusual and congenital melanotic macule of the tongue has rarely been reported. A 2-month-old infant with 3 pigmented lesion on the right side of the dorsal tongue was evaluated. They were brown black but not homogeneous in color, smooth, nonblanchable, and nonpalpable, with irregular margins. We recommend excisional biopsy under general anesthesia because of possibility of malignancy, but parents refuse invasive procedure. On a following-up examination of the child at the age of 1 year, the pigmented lesions were unchanged. We report a case of congenital melanotic macules on the tongue and a review of literature about the lesion.

Congenital Melanotic Macules of the Tongue: Case Report and Literature Review

김강혁,조정우,정승환,김진수,박재억,김창현 대한구강악안면병리학회 2016 대한구강악안면병리학회지 Vol.40 No.5

Oral hyperpigmentation is common in patients older 40 years. But lesions in a newborn are unusual and congenital melanotic macule of the tongue has rarely been reported. A 2-month-old infant with 3 pigmented lesion on the right side of the dorsal tongue was evaluated. They were brown black but not homogeneous in color, smooth, nonblanchable, and nonpalpable, with irregular margins. We recommend excisional biopsy under general anesthesia because of possibility of malignancy, but parents refuse invasive procedure. On a following-up examination of the child at the age of 1 year, the pigmented lesions were unchanged. We report a case of congenital melanotic macules on the tongue and a review of literature about the lesion.

애반딧불이 실내사육과정에서 알과 성충의 계절적 특성

김강혁,김하곤,정재훈,Kim, Kang-Hyeok,Kim, Ha-Gon,Jeong, Jae-Hun 한국응용곤충학회 2014 한국응용곤충학회지 Vol.53 No.3

Seasonal changes in the firefly (Luciola lateralis) were studied in the laboratory to understand biological characteristics. Fecundity varies with seasons; these were measures at $162.0{\pm}8.67$ in the winter, $226.9{\pm}15.84$ in the spring and $166.6{\pm}9.3$ in the summer. Seasonal change also influenced oviposition period ($6.9{\pm}0.59$ days in the winter, $16.1{\pm}1.10$ days in the spring and $8.2{\pm}0.61$ days in the summer). The firefly oviposited every $2.5{\pm}0.22$ days in the winter, $3.9{\pm}0.25$ days in the spring, and $2.3{\pm}0.14$ days in the summer. Oviposition occurred 3 times in the winter, and 4 times in the spring and summer. The number of eggs per cycle was $52.2{\pm}4.56$ and $55.9{\pm}4.38$ in winter and spring, respectively, and was lower in the summer ($42.2{\pm}3.76$). Egg period significantly differed among seasons. The life span of the firefly was $17.9{\pm}0.14$ days in the winter, $19.7{\pm}0.25$ days in the spring and $16.5{\pm}0.43$ days in the summer. 실험실 내에서 계절의 변화에 따른 애반딧불이(Luciola lateralis)의 계절적 특성을 조사하였다. 그 결과 산란 수는 겨울 $162.0{\pm}8.67$개, 봄 $226.9{\pm}15.84$개, 여름 $166.6{\pm}9.3$개였다. 산란 기간은 겨울 $6.9{\pm}0.59$일, 봄 $16.1{\pm}1.10$일, 여름 $8.2{\pm}0.61$일 이였다. 산란 간격은 겨울 $2.5{\pm}0.22$일, 봄 $3.9{\pm}0.25$일, 여름 $2.3{\pm}0.14$일 이였고, 산란 횟수는 겨울 $3.1{\pm}0.17$회, 봄 $4.1{\pm}0.29$회, 여름 $3.9{\pm}0.23$회 이였으며, 일회 산란 수 겨울 $52.2{\pm}4.56$개, 봄 $55.9{\pm}4.38$개, 여름 $42.2{\pm}3.76$개였다. 난기간은 겨울 $25.3{\pm}0.13$일, 봄 $29.6{\pm}0.18$일, 여름 $26.8{\pm}0.09$일 이였으며 부화하는데 걸리는 기간은 겨울 $3.0{\pm}0.28$일, 봄 $6.4{\pm}0.50$일, 여름 $4.6{\pm}0.32$일 이였다. 알의 부화율은 겨울 99.9%, 봄 99%, 여름 100%이였다. 계절별 성충수명은 겨울 암컷 $15.8{\pm}0.15$일, 수컷 $20.8{\pm}0.21$일 이였으며, 봄 암컷 $18.0{\pm}0.31$, 수컷 $21.4{\pm}0.37$일 이였고, 여름 암컷 $16.7{\pm}0.43$일, 수컷 $16.3{\pm}0.74$일 이였다. 또한 성충의 평균 수명을 보면 겨울 $17.9{\pm}0.14$일, 봄 $19.7{\pm}0.25$일, 여름 $16.5{\pm}0.43$일 이였다.

The Effect of Asthma Clinical Guideline for Adults on Inhaled Corticosteroids PrescriptionTrend: A Quasi-Experimental Study

김강혁,조비룡,신동욱,황승식,이혜진,안은미,윤재문,정윤희,남유선 대한의학회 2015 Journal of Korean medical science Vol.30 No.8

In order to increase inhaled corticosteroid (ICS) use and to reduce hospitalization, emergency department visits and ultimately the economic burden of asthma, “Korean Asthma Management Guideline for Adults 2007” was developed. To assess the guideline effects on physician’s ICS prescription for asthma, we conducted segmented regression and multilevel logistic regression using National Health Insurance claims database of outpatient visits from 2003 to 2010. We set each quarter of a year as a time unit and compared ICS prescription between before and after guideline dissemination. A total of 624,309 quarterly visits for asthma was observed. The ICS prescription rate before and after guideline dissemination was 13.3% and 16.4% respectively (P < 0.001). In the segmented regression, there was no significant guideline effect on overall ICS prescription rate. In multilevel logistic regression analyses, the effect of guideline on overall ICS prescription was not significant (odds ratio, 1.03; 95% CI, 1.00-1.06). In subgroup analysis, ICS prescription increased in secondary care hospitals (odds ratio, 1.15; 95% CI, 1.02-1.30) and in general hospitals (odds ratio, 1.10; 95% CI, 1.04-1.16). However, in primary clinics, which covered 81.7% of asthma cases, there was no significant change (odds ratio, 0.98; 95% CI, 0.94-1.02). From the in-depth interview, we could identify that the reimbursement criteria of the Health Insurance Review and Assessment Service and patient’s preference for oral drug were barriers for the ICS prescription. The domestic asthma clinical guideline have no significant effect on ICS prescription, especially in primary clinics.

멀티패스 SCTP의 경로검증을 위한 인증메커니즘

김강혁 ( Gangheok Kim ),송주석 ( Jooseok Song ) 한국정보처리학회 2009 한국정보처리학회 학술대회논문집 Vol.16 No.1

SCTP(Stream Control Transmission Protocol)는 새로운 전송계층 프로토콜로 TCP와 UDP의 장점을 결합한 대체 프로토콜로 기대되고 있다. 다양한 환경에서의 연구와 함께 SCTP에서 보안서비스를 제공하는 보안메커니즘에 관한 연구도 활발히 진행되고 있다. SCTP를 위한 E2E 보안메커니즘은 대부분 4계층 이상에서의 보안서비스를 결합한 방식으로 제안되고 있으며, IP계층에서의 보안을 위한 IPSEC은 멀티호밍의 특성을 적절히 지원하지 못하고 있다. 그래서 IP계층에서의 IP주소인증 및 IP패킷의 보안서비스 제공을 위한 보안메커니즘이 요구된다. 본 논문에서는 멀티호밍의 SCTP에서 각 IP 주소를 인증하고 비밀키를 공유하는 인증메커니즘을 제안한다.

실내 사육실에서 늦반딧불이 암컷의 생물적 특성

김하곤,정재훈,김강혁 한국응용곤충학회 2015 한국응용곤충학회 학술대회논문집 Vol.2015 No.04

무주군에서 2014년 6~7월 사이에 채집한 늦반딧불이 유충을 사육하여 생물적 특성을 조사하였다. 사육실의 조건은 온도를 23℃, 습도는 75%, 광주기는 14L:10D로 하였다. 유충은 곳체다슬기(Semisulcospira gottschei)를 먹이로 하여 번데기가 되기 전까지의 유충 기간을 사육하였다. 늦반딧불이의 전용기간, 번데기기간, 성충 기간과 산란수를 조사한 결과 전용기간은 4.3일, 번데기 기간은 9.7일, 암컷 성충기간은 10.7일이 걸렸다. 또한 산란 전기간은 5.3일, 산란기간은 4.5일 이였고, 암컷의 산란수는 65개 이였다. 일별 산란은 우화 후 4일까지 산란수가 전체 산란수의 약 95%를 차지하였다.

Enhanced photoactivity of stable colloidal TiO2 nanoparticles prepared in water by nanosecond infrared laser pulses

김유권,이규성,김유나,강혁 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.6

A simple laser ablation technique was used to prepare a stable colloidal TiO2 suspension in pure water. A transparent TiO2 aqueous solution was obtained within a few minutes and its photoactivity for the degradation of methylene blue was measured to be higher than that of commercial TiO2 nanoparticles. SEM analysis revealed that the average size of the nanoparticles increased from 20 to 40 nm as the laser power was raised from 0.5 to 2W. The variation in size, however, had little influence on the resulting photodegradation rate under the given condition. Instead, the photodegradation rate is related to the number of colloidal TiO2 particles in the aqueous solution, which increases proportionally to the ablation time. As the TiO2 particle density increases, however, the photoactivity is measured to be gradually reduced due to the formation of TiO2 aggregates. Thus, the optimum ablation time is 10-30 min under our ablation condition. Our results show that well-dispersed small TiO2 nanoparticles of about a few tens nm can be readily formed by laser ablation within only a few minutes and can be used as highly efficient photocatalysts for photocatalytic remediation of water.

Pneumomediastinum and Subcutaneous Emphysema after Periodontal Treatment Using Air-Flow Equipment : A Case Report

이정헌,김강혁,김준규,박재억,김창현 대한구강악안면병리학회 2015 대한구강악안면병리학회지 Vol.39 No.4

Subcutaneous emphysema is a rare but serious side effect of dental and oral surgery procedures. The condition is characterized by air being forced underneath the tissue, leading to swelling, crepitus on palpation, and with potential to spread along the fascial planes to the periorbital, mediastinal, pericardial, and/or thoracic spaces. A wide range of causes have been documented for the origin of subcutaneous emphysema during dental treatment including: crown preparations, other operative procedures, endodontic therapy, extractions, as well as oral surgery procedures. The patient was a 58-year-old woman who presented to the Seoul Saint mary’s hospital emergency department with a chief complaint of facial edema, dyspnea and chest discomfort after periodontal treatment using an air-flow equipment in local dental clinic. During treatment in the emergency department, oxygen therapy and intravenous injection of steroid and anti-histamine was done. it was noted that the patient had pain and swelling on left lower molar region, pus discharging on same site. Severe edema was observed on periorbital region to neck with heatness. An audible crepitus sound was heard during palpation on facial area. Neck CT scan and antibiotic therapy was done, as symptom suggesting dental abscess is observed. 3 hours after injection of antibiotics, the patient’s symptom was relieved, but she felt chest discomfort continuously. CT scan with constrast depicted confluent and extensive soft tissue emphysematous changes involving face and deep neck spaces and pneumomediastinum. The patient was refered to thoracic surgery department, oxygen therapy was decided continuously. After 10 hours, patient’s chief complaint was resolved, and discharged. After 1 week, all symptom was disappear and follow-up neck CT scan finding was disappearance of edema and pnuemomediastinum. We report a case of cervical subcutaneous emphysema and pneumomediastinum occurring after periodontal treatment using an air-flow equipment and case on the diagnosis and treatment of subcutaneous emphysema and pneumomediastinum, along with a review of the literature.