FC 1-4 : A survey of attitudes, knowledge, and behavior regarding sun exposure and sunscreen use

( Sih Yeok Jang ),( Hyeong Ho Ryu ),( Eun Jung Hwang ),( Hyun Sun Park ),( So Yun Cho ),( Hyun Sun Yoon ) 대한피부과학회 2013 대한피부과학회 학술발표대회집 Vol.65 No.2

Background: Although sunscreen is used as a primary strategy to prevent sunburn, photoaging and skin cancer, only a few people regularly use sunscreen. Objectives: To investigate the awareness of effects of sunlight, the extent of sun exposure, and the behaviors about sunscreen uses in Korean. Methods: A questionnaire was administered 255 adult patients visited Dermatology Department at Seoul National University Boramae Hospital. It included questions about the awareness of benefit or harm of sunlight, perceived and actual extent of sun exposure, the use of sun-protective methods including sunscreen. Results: Sun exposure was chosen as the major cause of dyschromia (61.2%), skin cancer (62.8%) and wrinkle (28.6%). Respondents were likely to underestimate the extent of sun exposure. On average, quite a few respondents stated that they were exposed to sunlight more than one hour per day (23.1% on weekdays, 53.4% on weekends). But, only 8.7% thought that their sun exposures were problematic and 62.2% of respondents considered moderate sunlight exposure good for health. People`s sun protective behaviors were inadequate: only 30.8% used sunscreen regularly; 18.4% have never used sunscreen. SPF was the most important factor choosing sunscreen and 86.0% used sunscreen labeled SPF over 30. In contrast, only 40.3% used PA+++ sunscreen. Conclusion: Despite a fairly good knowledge about harmful effects of sunlight, people underestimated the risks of their sun exposure and behaviors were suboptimal.

한국인에서 일광노출과 자외선차단제에 대한 인식과 사용 행태 연구

장시혁 ( Si Hyeok Jang ),박현선 ( Hyun Sun Park ),조소연 ( So Yun Cho ),윤현선 ( Hyun Sun Yoon ) 대한피부과학회 2015 대한피부과학회지 Vol.53 No.1

Background: Although sunscreen is used as a primary strategy for the prevention of sunburn, photoaging, and skincancer, few people regularly use sunscreen. Objective: To investigate awareness regarding the effects of sunlight, the extent of sun exposure, and sunscreen usebehaviors in Korean subjects. Methods: A questionnaire was administered to 467 adult patients who visited the Dermatology Department at SeoulNational University Boramae Hospital. The questionnaire covered demographic characteristics, causes of wrinkles,sunspots, and skin cancer, awareness of the harmful effects of sun exposure, perceived and actual extent of sunexposure, and the use of sun-protective methods including sunscreen. Results: Sun exposure was selected as the major cause of age spots (60.6%), skin cancer (60.9%), and wrinkles(25.9%). Respondents were likely to underestimate the extent of sun exposure. On average, quite a few respondentsstated that they were exposed to sunlight for more than one hour per day (22.7% on weekdays, 52.4% onweekends). However, only 9.4% of respondents thought that their sun exposure was problematic and 62.7% ofrespondents considered moderate sunlight exposure healthy. Respondents`` sun-protective behaviors were inadequate:only 29.8% used sunscreen regularly, and 16.5% have never used sunscreen. SPF was the most important factor inchoosing sunscreen, and 83.3% used a sunscreen with a labeled SPF over 30. By contrast, only 34.6% ofrespondents used PA+++ sunscreen. Conclusion: Despite fairly good knowledge regarding the harmful effects of sunlight, subjects underestimated therisks of their sun exposure and sun-protective behaviors were suboptimal. Education on the risk of UV exposure andeffects of sunscreen is still needed. (Korean J Dermatol 2015;53(1):16∼22)

도시공원 열환경 실측과 근린주민 의식조사에 따른 체감열 특성 평가

박선영(Park, Sun-Young),주진희(Ju, Jin-Hee),윤용한(Yoon, Young-Han) 한국도시설계학회 2009 도시설계 : 한국도시설계학회지 Vol.10 No.4

본 연구는 청주시에 위치한 도시공원을 대상으로 기온·습도ㆍ풍향ㆍ풍속 및 산소 등 여름철 도시공원이 내포하고 있는 열섬저감효과를 실측하고, 근린주민을 대상으로 설문을 실시하여 체감열에 대한 의식조사를 수행하였다. 이에 열환경 실측과 근린주민 의식조사의 결과를 비교·검토하여 근린주민의 체감의식까지 수용된 실측결과를 바탕으로 실제 공원의 배치 및 식재설계 등 계획에 입안할 수있는 기초자료를 제공함을 목적으로 한다. 연구결과는 다음과 같다. 공원 주변의 기온저감효과와 영향범위, 공원의 쾌적감, 냉량감 및 청정감 등의 항목에서 기온의 실측데이터와 주민의식조사를 비교한 결과, 풍향을 중심으로 풍상측과 풍하측을 구분한 실측 및 의식조사의 결과를 제외하고 공원의 규모가 클수록, 공원으로의 거리가 가까워질수록 거주하는 근린주민은 쾌적감을 느낀다고 응답하였다. 따라서, 도시공원에 대한 열섬현상 완화를 고려해 같은 규모의 공원일 경우, 분산 배치하는 것이 좋으나 공원규모가 클수록 풍하측 기온저감의 영향범위가 넓어지는 경향을 나타내 공원 규모의 확대가 중요함을 보여주고 있다. This study has investigated the air temperature, humidity, wind direction, wind velocity and oxygen in urban parks in Cheong-ju. Heat-island temperature decrease effect in urban parks during summer was measured, and the sensible consciousness of neighborhood residents was investigated through a questionnaire survey. Based on the actual results after comparatively analyzing the measurement of thermal environment and sensible consciousness of neighborhood residents, basic data are presented to elaborate on the urban development plans such as for park placement and planting design. The study result showed that neighborhood residents felt greater comfort sensation when they are closely located to a larger park. When actual temperature data and sensible consciousness of neighborhood residents were compared in terms of temperature decrease effect and extent, comfort sensation, coldness sensation, and cleanliness sensation, similar results were observed in almost all categories except for wind direction which was divided into windward and leeward. Therefore, the significance of this paper is that its results can be used to elaborate realistic and practical park development and management plans in green network and resident’s use of parks.

한국인 폐확산능 정상예측식의 임상적 유용성과 정확성

나승원 ( Seung Won Ra ),박태선 ( Tai Sun Park ),홍윤기 ( Yoon Ki Hong ),홍상범 ( Sang Bum Hong ),심태선 ( Tae Sun Shim ),임채만 ( Chae Man Lim ),이상도 ( Sang Do Lee ),고윤석 ( Youn Suck Koh ),김우성 ( Woo Sung Kim ),김동순 ( Dong 대한결핵 및 호흡기학회 2008 Tuberculosis and Respiratory Diseases Vol.64 No.2

연구배경: 폐확산능을 해석하는 데 필요한 정상예측식으로는 한국인을 대상으로 하여 박 등이 개발한 식(박 식)이 있으나 아직 외국 정상예측식을 많이 사용하고 있다. 이에 국내에서 많이 사용하는 외국 정상예측식인 Burrows 식과 박 식의 임상적 유용성과 정확성을 비교하고자 하였다. 방법: 1. 임상적 유용성 연구; 2006년 7월부터 12월까지 6개월간 폐확산능검사를 시행한 환자 중 두 식을 각각 정상예측식으로 적용하였을 때 폐확산능 해석이 다른 276명(대상군 A)을 대상으로 하였다. 대상군 A에게 두 식을 각각 적용하였을 때 폐확산능 해석과 임상적 판단과의 일치도를 비교하여 임상적 유용성을 평가하였다. 2. 간질성폐질환 진단의 정확성 비교; 2001년부터 2006년까지 폐조직검사를 시행하여 확진된 간질성폐질환군과 서울아산병원에서 모집한 정상군을 대상으로 하여 정상예측식으로 두 식을 각각 적용하였을 때 폐확산능 해석의 정확도를 비교하였고, 두 식이 차이가 나는지 맥니머의 카이스퀘어 검정을 하였다. 결과: 1. 임상적 판단과의 일치도 비교; 276명을 임상정보를 토대로 폐확산능을 예측하여 분류한 결과 정상 54명, 감소 220명, 불분명이 2명이었다. 예측식으로 박 식과 Burrows 식을 적용하였을 때 임상적 판단과 일치하는 환자는 각각 78%와 22%이었다(p<0.001). 2. 간질성폐질환 진단의 정확성 비교; 박 식은 민감도 90.1%, 특이도 100%이었고 Burrows 식은 민감도 64.2%, 특이도 100%로 민감도가 통계학적으로 유의하게 박 식이 높았다(p<0.001). 결론: 우리나라 정상예측식인 박 식이 외국 정상예측식인 Burrows 식을 정상예측식으로 적용하는 것보다 임상적 유용성이나 간질성폐질환 진단의 민감도에서 더 우월하였다. 향후 폐확산능검사의 정상예측식으로 박 식을 사용해야 할 것으로 사료된다. Background: Park et al. developed the Korean reference equation for the measurement of diffusing capacity in 1985. However, the equation has not been widely used in Korea and foreign reference equations have been popularly used. We intended to compare the clinical usefulness and the accuracy of the the Korean reference equation (Park`s equation) with that of the foreign equation (Burrows` equation) that is commonly used in Korea. Methods: 1. Evaluation of clinical usefulness; Among 1,584 patients who underwent diffusing capacity (DLCO) at the Asan Medical Center from July to December 2006, group A subjects included 276 patients who had different interpretations of DLCO in trials employing Burrows` equation and Park`s equation. Clinical assessment was decided by consensus of two respiratory physicians. In order to evaluate the clinical usefulness of Burrows` equation and Park`s equation, agreement of clinical assessment and DLCO interpretation were measured. 2. Evaluation of accuracy; Group B subjects were 81 patients with interstitial lung disease (ILD) and 39 normal subjects. The 81 ILD patients were diagnosed following a surgical lung biopsy. The accuracy of diagnosing ILD as well as sensitivity and specificity were evaluated according to the use of the reference equations (Burrows` equation and Park`s equation) for DLCO. Results: Agreement between clinical assessment and interpretation of DLCO was 22% for the use of Burrows` equation and 78% for the use of Park`s equation. The sensitivity and specificity of the Burrows` equation for diagnosing ILD were 64.2% and 100%. The sensitivity and specificity of the Park`s equation for diagnosing ILD were 90.1% and 100%. The sensitivity of the Park`s equation for diagnosing ILD was significantly higher than that of Burrows` equation (p<0.001). Conclusion: The Korean reference equation (Park`s equation) was more clinically useful and had higher sensitivity for diagnosing ILD than the foreign reference equation (Burrows` equation). (Tuberc Respir Dis 2008;64:80-86)

단일 밴드 중적외선 영상으로부터 표면온도 추정을 위한 기초연구

박욱 ( Wook Park ),이윤경 ( Yoon Kyung Lee ),원중선 ( Joong Sun Won ),이승근 ( Seung Geun Lee ),김종민 ( Jong Min Kim ) 大韓遠隔探査學會 2008 大韓遠隔探査學會誌 Vol.24 No.2

3~5μm 파장대의 중적외선 영상은 화산 활동이나 산불과 같이 고온 현상을 관측하는데 효과적이다. 그러나 중적외선 영역은 지표의 복사율과 대기의 영향으로 인한 변화가 매우 심하고, 특히 낮 영상의 경우 태양 복사량에 의한 영향도 고려해야 하는 어려움이 있다. 따라서 단일밴드인 중적외선 영상을 이용하여 표면온도를 얻기 위해서는 영상이 취득된 시간과 장소에서 관측된 태양 복사량 및 여러 가지 대기 변수가 필요하다. 이 연구는 기존의 다중밴드 기반의 중적외선 영상 활용방법과 달리 단일 밴드 중적외선 영상을 이용하여 표면온도 측정을 위한 기초연구에 그 목적이 있다. 이를 위하여 MODIS 영상을 대상으로 MODTRAN을 사용하여 중적외선 영역의 대기보정 기법을 적용 한 뒤 복사전달 모델을 이용하여 지표의 온도를 측정하였다. 획득된 온도 영상의 정밀도를 측정하기 위해 기존의 온도 알고리즘인 MODIS Sea Surface Temperature 알고리즘에 의해 얻어진 해수온도와 비교를 통하여 오차 원인에 대해 분석을 실시하였다. 두 결과의 온도 차는 낮 영상의 경우 0.89±0.54℃ 밤 영상의 경우 1.25±0.41℃로 비교적 긍정적인 결과를 보였다. 그러나 낮 영상의 육지의 경우 대기에 의한 영향보다 태양빛의 반사가 주된 오차의 원인이 되며 이는 지표 복사율에 의한 영향이 매우 크게 작용하고 있음을 추정할 수 있다. 이 연구는 현재까지 해수에 대한 적용에 국한된 것으로 육상의 경우 복사율 변화가 매우 크기 때문에 중적외선 단일밴드에 의한 온도추정이 매우 어려울 것으로 예상된다. Middle-infrared (MIR) spectral region between 3.0 and 5.0 μm in wavelength is useful for observing high temperature events such as volcanic activities and forest fire. However, atmospheric effects and sun irradiance in day time has not been well studied for this MIR spectral band. The objectives of this basic study is to evaluate atmospheric effects and eventually to estimate surface temperature from a single channel MIR image, although a typical approach utilize split-window method using more than two channels. Several parameters are involved for the correction including various atmospheric data and sun-irradiance at the area of interest. To evaluate the effect of sun irradiance, MODIS MIR images acquired in day and night times were used for comparison. Atmospheric parameters were modeled by MODTRAN, and applied to a radiative transfer model for estimating the sea surface temperature. MODIS Sea Surface Temperature algorithm based upon multi-channel observation was performed in comparison with results from the radiative transfer model from a single channel. Temperature difference of the two methods was 0.89±0.54℃ and 1.25±0.41℃ from the day-time and night-time images, respectively. It is also shown that the emissivity effect has by more largely influenced on the estimated temperature than atmospheric effects. Although the test results encourage using a single channel MIR observation, it must be noted that the results were obtained from water body not from land surface. Because emissivity greatly varies on land, it is very difficult to retrieval land surface temperature from a single channel MIR data.

Protective Effects of N-acetylcystenine and Selenium against Doxorubicin Toxicity in Rats

Yeo-sung Yoon,Sun-don Kim,Min-hye Lee,Heung-shik S.Lee,In-se Lee,Je-kyung Sung,Eun-sung Park 대한수의학회 2003 Journal of Veterinary Science Vol.4 No.2

Effects of N-acetylcysteine and Selenium against Doxorubicin Toxicity in RatsEun-sung Park, Sun-don Kim1, Min-hye Lee, Heung-shik S. Lee, In-se Lee, Je-kyung Sung and Yeo-sung Yoon*

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

한국의 정신분열병 외래 환자의 직ㆍ간접비용

박종익,송선희,서동우,장현종,이종국,장안기,김윤,이철,홍진표 大韓神經精神醫學會 2000 신경정신의학 Vol.39 No.3

연구목적 : 정신분열병 외래 환자의 직접 비용과 간접 비용을 추산해 보고, 의료 자원의 적절한 운용과 효과적인 배분을 위한 보건 정책의 기초자료로 사용하고자 한다. 방 법 : 정신분열병 진단을 받은 289명의 환자를 대상으로 6개월간 외래를 방문하면서 사용한 의료비와 시간을 조사하여 직접 비용을 추산하였고, 이 기간 동안 소실된 생산성을 간접 비용으로 환산하였다. 만성질환인 관상동맥 질환을 앓고 있는 환자 82명을 대조군으로 하여 비용을 비교하였다. 결 과 : 정신분열병 환자의 실업률은 72.1%였으며, 직장을 가지고 있는 경우에도 단순노무직의 비율이 64.5%로 매우 높았다. 정신분열병의 직접 비용은 평균 81.5만원으로 관상동맥 질환의 평균 71.5 만원보다 상대적으로 많이 추산되었으나 유의하지는 않았다. 간접 비용은 평균 645.6만원, 258.9 만원으로 정신분열병군이 2.5배 정도 높았다. 결 론 : 정신분열병은 다른 만성질환에 비하여 상대적으로 매우 고비용이 요구되는 질환이며, 보다 체계적인 비용의 추산을 통하여 양질의 정신 보건 서비스를 제공할 수 있는 토대가 마련되어야 할 것이다. Objectives : We have aimed to estimate the direct and indirect costs of treating out-patients with schizophrenia in Korea, to use this fundamental data for the effective management and proper distribution of the medical resource. Method : To estimate the direct cost, we surveyed the medical cost and time of two hundred and eighty-nine out-patients with schizophrenia for six months. And the lost productivity as many months was converted into the indirect cost. Those of eighty-two coronary heart disease patients were also estimated as a comparison group. Results : An unemployement rate of schizophrenic patients was 72.1 percent. Moreover the ratio of the laborer in the sample was, even if employed, 64.5 percent. The mean direct cost of schizophrenic patients was, about 815,000 won, higher than that of coronary heart disease, 715,000 won however it was not statistically significant. The former was also estimated 2.5 times more than the latter for the indirect cost, or 6,456,000 won versus 2,589,000 won. Conclusion : Schizophrenia is a relatively costly illness compared to other chronic illness, so the systematic estimation of the cost is necessary to provide mental health service of high quality.

메치실린 내성 포도상구균에 대한 SK-302의 시험관내 및 생체내 효과

박윤선,김수기,신운섭,최선주,정종순,이종수 關東大學校醫科大學醫科學硏究所 1998 關東醫大學術誌 Vol.2 No.1

SK-302 is the active compound purified from culture filtrate of a streptomyces species (streptomyces sp. 302). The in vitro and in vivo antibacterial activities of SK-302 were evaluated against 6 clinically isolated MRSA strains and compared with the activities of vancomycin. SK-302 had node in virto antistaphylocoal activity stronger than that of vancomycin exhibiting MIC's, while vancomycin showed very weak 4 to 8fold lower than that of vancomycin. In SK-302 showed killing activity at the MIC, so SK-302 was superior to vancomycin. Furthermore, in acute systemic infections in mice, the ED_50s of SK-302 against infections by high-resistance MRSA were 30 to 40-feold less than that of vancomycin, therefore SK-302 showed potent in vive therapeutic efficacy against MRSA infection, These results suggest that SK-302 has excellent in virto in and in vivo activities against high-resistance MRSA.

승모판대치술후 도플러 심초음피를 이용한 인공 판막의 종류에 따른 최대혈류속도와 평균혈류속도에 관한 연구

박선우,김권배,김윤년,김기식 啓明大學校 醫科大學 1988 계명의대학술지 Vol.7 No.2

The conventional non-invasive and invasive technique have limitations in evaluating cardiac prosthetic valves and artificial valves. We have used continuous wave Doppler echocardiography to evaluate 48 patients with tissue and mechanical mitral valves implanted within 4 months prior to examination. The results are as follows. 1) Of these patients, male are 28. The mean ages of male are 35.60 (yr) and female are 41.82. 2) The differences of peak and mean velocities of prosthetic acardiac valves between male and female are not significant, but the differences of valvular size between male and female are significant(male:31.00±1.30(mm), female:29.36±2.11, p<0.01). 3) The difference of size and flow velocities between mechanical (Edwards-Duromedics) and tissue(Ionescue-Shiley) valves are not significant, but the ages of patients with mechanical valves are significantly lower than tissue valves(mechanical valve; 34.05±11.28, tissue valve; 43.62±11.26, p<0.01). 4) The differences of flow velocities between mechanical and tissue valves, sizes of which are 31mm, are significant statistically (peak velocity; 130.15±24.59 vs 110.00±19.41, mean velocity; 74.49±23.14 vs 51.38±12.71, p<0.01). 5) The sizes of valves are larger, the peak and mean velocities are lower, but it is not significant statistically. The results indicated that Doppler echocardiography is a useful method for evaluating function of prosthetic valves.