AIM： To evaluate the prevalence of chronic gastroin- testinal symptoms and their impact on health-related quality of life （HRQOL） in the Korean population. METHODS： A cross-sectional survey, using a reliable and v...AIM： To evaluate the prevalence of chronic gastroin- testinal symptoms and their impact on health-related quality of life （HRQOL） in the Korean population. METHODS： A cross-sectional survey, using a reliable and valid Rome I] based questionnaire, was per- formed on randomly selected residents, between 18 and 69 years in age. All respondents were interviewed at their homes or offices by a team of interviewers. The impact of chronic gastrointestinal symptoms on HRQOL was assessed using the Korean version of the 36-item Short-Form general health survey （SF-36）. RESULTS： Of the 1807 eligible subjects, 1417 （78.4%： male 762; female 655） were surveyed. Out of the respondents, 18.6% exhibited at least one chronic gastrointestinal symptom. The prevalence of gastro- esophageal reflux disease （GERD）, defined as heart- burn and/or acid regurgitation experienced at least weekly, was 3.5% （95% CI, 2.6-4.5）. The prevalence of uninvestigated dyspepsia, irritable bowel syndrome （IBS） and chronic constipation based on Rome Ⅱ criteria were 11.7% （95% CI, 10.1-13.5）, 2.2% （95% CI, 1.5-3.1）, and 2.6% （95% CI, 1.8-3.5） respectively. Compared with subjects without chronic gastrointesti- nal symptoms （n = 1153）, those with GERD （n = 50）, uninvestigated dyspepsia （n = 166） and IBS （n = 31） had significantly worse scores on most domains of the SF-36 scales. CONCLUSION： The prevalence of GERD, uninvesti- gated dyspepsia and IBS were 3.5%, 11.7% and 2.2% respectively, in the Korean population. The health- related quality of life was significantly impaired in subjects with GERD, uninvestigated dyspepsia and IBS in this community.展开更多
The cloud phase composition of cold clouds in the Antarctic atmosphere is explored using data from the Moderate Resolution Imaging Spectroradiometer （MODIS） and Cloud-Aerosol Lidar with Orthogonal Polarization （CAL...The cloud phase composition of cold clouds in the Antarctic atmosphere is explored using data from the Moderate Resolution Imaging Spectroradiometer （MODIS） and Cloud-Aerosol Lidar with Orthogonal Polarization （CALIOP） instruments for the period 2000-2006. We used the averaged fraction of liquid-phase clouds out of the total cloud amount at the cloud tops since the value is comparable in the two measurements. MODIS data for the winter months （June, July, and August） reveal liquid cloud fraction out of the total cloud amount significantly decreases with decreasing cloud-top temperature below 0°C. In addition, the CALIOP vertical profiles show that below the ice clouds, low-lying liquid clouds are distributed over ～20% of the area. With increasing latitude, the liquid cloud fraction decreases as a function of the local temperature. The MODIS-observed relation between the cloud-top liquid fraction and cloud-top temperature is then applied to evaluate the cloud phase parameterization in climate models, in which condensed cloud water is repartitioned between liquid water and ice on the basis of the grid point temperature. It is found that models assuming overly high cut-offs （ -40°C） for the separation of ice clouds from mixed-phase clouds may significantly underestimate the liquid cloud fraction in the winter Antarctic atmosphere. Correction of the bias in the liquid cloud fraction would serve to reduce the large uncertainty in cloud radiative effects.展开更多
The ever-increasing demand for smart optoelectronics spurs the relentless pursuit of transparent wireless devices as a game-changing technology that can provide unseen visual information behind the electronics.To enab...The ever-increasing demand for smart optoelectronics spurs the relentless pursuit of transparent wireless devices as a game-changing technology that can provide unseen visual information behind the electronics.To enable successful operation of the transparent wireless devices,their power sources should be highly transparent in addition to acquiring reliable electrochemical performance.Among various transparent power sources,supercapacitors(SCs)have been extensively investigated as a promising candidate due to their exceptional cyclability,power capability,material diversity,and scalable/low-cost processability.Herein,we describe current status and challenges of transparent SCs,with a focus on their core materials,performance advancements,and integration with application devices.A special attention is devoted to transparent conductive electrodes(TCEs)which act as a keyenabling component in the transparent SCs.Based on fundamental understanding of optical theories and operating principles of transparent materials,we comprehensively discuss materials chemistry,structural design,and fabrication techniques of TCEs.In addition,noteworthy progresses of transparent SCs are briefly overviewed in terms of their architectural design,opto-electrochemical performance,flexibility,form factors,and integration compatibility with transparent flexible/wearable devices of interest.Finally,development direction and outlook of transparent SCs are explored along with their viable roles in future application fields.展开更多
A promising strategy for the selective growth of ZnO nanorods on SiO2/Si substrates using a graphene buffer layer in a low temperature solution process is described. High densities of ZnO nanorods were grown over a la...A promising strategy for the selective growth of ZnO nanorods on SiO2/Si substrates using a graphene buffer layer in a low temperature solution process is described. High densities of ZnO nanorods were grown over a large area and most ZnO nanorods were vertically well-aligned on graphene. Furthermore, selective growth of ZnO nanorods on graphene was realized by applying a simple mechanical treatment, since ZnO nanorods formed on graphene are mechanically stable on an atomic level. These results were confirmed by first principles calculations which showed that the ZnO-graphene binding has a low destabilization energy. In addition, it was found that ZnO nanorods grown on SiO2/Si with a graphene buffer layer have better optical properties than ZnO nanorods grown on bare SiO2/Si. The nanostructured ZnO-graphene materials have promising applications in future flexible electronic and optical devices.展开更多
基金Supported by The Korean Society of Neurogastroenterlogy and Motility Fund and a 2000 grant from the Korean Academy of Medical Sciences, KMA
文摘AIM： To evaluate the prevalence of chronic gastroin- testinal symptoms and their impact on health-related quality of life （HRQOL） in the Korean population. METHODS： A cross-sectional survey, using a reliable and valid Rome I] based questionnaire, was per- formed on randomly selected residents, between 18 and 69 years in age. All respondents were interviewed at their homes or offices by a team of interviewers. The impact of chronic gastrointestinal symptoms on HRQOL was assessed using the Korean version of the 36-item Short-Form general health survey （SF-36）. RESULTS： Of the 1807 eligible subjects, 1417 （78.4%： male 762; female 655） were surveyed. Out of the respondents, 18.6% exhibited at least one chronic gastrointestinal symptom. The prevalence of gastro- esophageal reflux disease （GERD）, defined as heart- burn and/or acid regurgitation experienced at least weekly, was 3.5% （95% CI, 2.6-4.5）. The prevalence of uninvestigated dyspepsia, irritable bowel syndrome （IBS） and chronic constipation based on Rome Ⅱ criteria were 11.7% （95% CI, 10.1-13.5）, 2.2% （95% CI, 1.5-3.1）, and 2.6% （95% CI, 1.8-3.5） respectively. Compared with subjects without chronic gastrointesti- nal symptoms （n = 1153）, those with GERD （n = 50）, uninvestigated dyspepsia （n = 166） and IBS （n = 31） had significantly worse scores on most domains of the SF-36 scales. CONCLUSION： The prevalence of GERD, uninvesti- gated dyspepsia and IBS were 3.5%, 11.7% and 2.2% respectively, in the Korean population. The health- related quality of life was significantly impaired in subjects with GERD, uninvestigated dyspepsia and IBS in this community.
基金funded by Ko-rean Center for Atmospheric Sciences and Earthquake Re-search 2010–1178, and US Department of Energy grantDE-FG02-01ER63257
文摘The cloud phase composition of cold clouds in the Antarctic atmosphere is explored using data from the Moderate Resolution Imaging Spectroradiometer （MODIS） and Cloud-Aerosol Lidar with Orthogonal Polarization （CALIOP） instruments for the period 2000-2006. We used the averaged fraction of liquid-phase clouds out of the total cloud amount at the cloud tops since the value is comparable in the two measurements. MODIS data for the winter months （June, July, and August） reveal liquid cloud fraction out of the total cloud amount significantly decreases with decreasing cloud-top temperature below 0°C. In addition, the CALIOP vertical profiles show that below the ice clouds, low-lying liquid clouds are distributed over ～20% of the area. With increasing latitude, the liquid cloud fraction decreases as a function of the local temperature. The MODIS-observed relation between the cloud-top liquid fraction and cloud-top temperature is then applied to evaluate the cloud phase parameterization in climate models, in which condensed cloud water is repartitioned between liquid water and ice on the basis of the grid point temperature. It is found that models assuming overly high cut-offs （ -40°C） for the separation of ice clouds from mixed-phase clouds may significantly underestimate the liquid cloud fraction in the winter Antarctic atmosphere. Correction of the bias in the liquid cloud fraction would serve to reduce the large uncertainty in cloud radiative effects.
基金supported by the Basic Science Research Program(2018R1A2A1A05019733)Wearable Platform Materials Technology Center(2016R1A5A1009926)through the National Research Foundation of Korea(NRF)grant by the Korean Government(MSIT)Industry Technology Development Program(10080540)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)
文摘The ever-increasing demand for smart optoelectronics spurs the relentless pursuit of transparent wireless devices as a game-changing technology that can provide unseen visual information behind the electronics.To enable successful operation of the transparent wireless devices,their power sources should be highly transparent in addition to acquiring reliable electrochemical performance.Among various transparent power sources,supercapacitors(SCs)have been extensively investigated as a promising candidate due to their exceptional cyclability,power capability,material diversity,and scalable/low-cost processability.Herein,we describe current status and challenges of transparent SCs,with a focus on their core materials,performance advancements,and integration with application devices.A special attention is devoted to transparent conductive electrodes(TCEs)which act as a keyenabling component in the transparent SCs.Based on fundamental understanding of optical theories and operating principles of transparent materials,we comprehensively discuss materials chemistry,structural design,and fabrication techniques of TCEs.In addition,noteworthy progresses of transparent SCs are briefly overviewed in terms of their architectural design,opto-electrochemical performance,flexibility,form factors,and integration compatibility with transparent flexible/wearable devices of interest.Finally,development direction and outlook of transparent SCs are explored along with their viable roles in future application fields.
文摘A promising strategy for the selective growth of ZnO nanorods on SiO2/Si substrates using a graphene buffer layer in a low temperature solution process is described. High densities of ZnO nanorods were grown over a large area and most ZnO nanorods were vertically well-aligned on graphene. Furthermore, selective growth of ZnO nanorods on graphene was realized by applying a simple mechanical treatment, since ZnO nanorods formed on graphene are mechanically stable on an atomic level. These results were confirmed by first principles calculations which showed that the ZnO-graphene binding has a low destabilization energy. In addition, it was found that ZnO nanorods grown on SiO2/Si with a graphene buffer layer have better optical properties than ZnO nanorods grown on bare SiO2/Si. The nanostructured ZnO-graphene materials have promising applications in future flexible electronic and optical devices.
