461 research outputs found
Two-dimensional TiO2 inverse opal with a closed top surface structure for enhanced light extraction from polymer light-emitting diodes
Fractional exhaled nitric oxide measurements in rhinitis and asthma in children.
Exaled nitric oxide (FeNO) is considered a good noninvasive marker to assess airway inflammation in asthma and allergic rhinitis. In asthma, exhaled NO is very useful to verify adherence to therapy, and to predict upcoming asthma exacerbations. It has been also proposed that adjusting anti-inflammatory drugs guided by the monitoring of exhaled NO, could improve overall asthma control. Other studies showed increased FeNO levels in subjects with allergic rhinitis
Rapid Dye Regeneration Mechanism of Dye-Sensitized Solar Cells
During the light-harvesting process of dye-sensitized solar cells (DSSCs), the hole localized on the dye after the charge separation yields an oxidized dye, D^+. The fast regeneration of D^+ using the redox pair (typically the I^–/I_(3)^– couple) is critical for the efficient DSSCs. However, the kinetic processes of dye regeneration remain uncertain, still promoting vigorous debates. Here, we use molecular dynamics simulations to determine that the inner-sphere electron-transfer pathway provides a rapid dye regeneration route of ∼4 ps, where penetration of I^− next to D^+ enables an immediate electron transfer, forming a kinetic barrier. This explains the recently reported ultrafast dye regeneration rate of a few picoseconds determined experimentally. We expect that our MD based comprehensive understanding of the dye regeneration mechanism will provide a helpful guideline in designing TiO_2−dye−electrolyte interfacial systems for better performing DSSCs
Prediction of the Chemical Composition and Fermentation Parameters of Fresh Coarse Italian Ryegrass Haylage Using Near Infrared Spectroscopy
Italian ryegrass (Lolium multiflorum) is an annual forage grass species which is widely cultivated in South Korea. It grows extensively in the southern part of the country and is an important component of winter forage for livestock. Each year, in Korea, over one million hectares of Italian ryegrass is converted to round bale haylage. Quality control is an important field in forage utilization research and marketing, and involves the estimation of forage nutrient content. Wet chemistry is the traditional method used to analyze the nutrient content of forage. However, this technique is often destructive, expensive, and time consuming, and it is not suitable for real-time feedstuff analysis. Near infrared spectroscopy (NIRS), on the other hand, is an alternative technique that has several major advantages over traditional methods. The analysis of silage nutrient content, using NIR, conventionally includes the drying and milling of samples. However, these processes can lead to reduction of volatile acids, which are important components of silage. NIRS can be affected by spectral regions, drying and grinding methods, particle size, packing density and the temperature of samples (Reeves and Blosser, 1991). In order to obtain accurate NIRS results, sample preparation, and the measurement conditions of the calibration set and predicted samples, need to match. The objectives of this study were to (1) assess the usefulness of NIRS in determining the nutritional composition and fermentative parameters of fresh coarse samples of Italian ryegrass haylage, (2) assess the predictive value of various NIRS calibration models, and (3) explore cost-effective and time saving methods for forage quality estimation, in field populations
Current Status of Biportal Endoscopic Decompression for Lumbar Central Stenosis
Degenerative lumbar spinal stenosis commonly occurs in elderly patients aged above 50-60 years. Surgical intervention is indicated for patient refractory to conservative management, and microscopic decompression has been used for direct spinal canal decompression. The development of surgical instruments and spinal endoscopic system can make possible endoscopic surgery as the useful treatment option for degenerative lumbar disease. Endoscopic spine surgery was mainly preformed in lumbar disc disease through transforaminal route. And then, endoscopic interlaminar approach was introduced using endoscopic drill, more developed endoscopic disc forceps, and Kerrison punches, and so on. Uniportal endoscopic spine surgery through interlaminar space can make possible direct spinal canal decompression in cases with lumbar spinal stenosis, however stiff learning curve still remains the limitation of this surgery. Biportal endoscopic spine surgery was also introduced as the minimal invasive spine surgery, which is basically similar to microscopic surgery and relatively familiar approach to spine surgeons. Biportal endoscopic spine surgery can offer clean operative view in monitor through continuous irrigation and endoscope with large diameter compared to uniportal endoscopic equipment, and this approach may be alternative surgical approach for decompression of lumbar spinal stenosis. Now many spine surgeons perform biportal endoscopic surgery for lumbar central spinal stenosis, and the reports have been published. He we write the technical procedure of biportal endoscopic surgery for lumbar spinal stenosis, discussing about surgical considerations, and also review the surgical outcomes from the previously published articles
Active subglacial lakes and channelized water flow beneath the Kamb Ice Stream
We identify two previously unknown subglacial lakes beneath the stagnated trunk of the Kamb Ice Stream (KIS). Rapid fill-drain hydrologic events over several months are inferred from surface height changes measured by CryoSat-2 altimetry and indicate that the lakes are probably connected by a subglacial drainage network, whose structure is inferred from the regional hydraulic potential and probably links the lakes. The sequential fill-drain behavior of the subglacial lakes and concurrent rapid thinning in a channel-like topographic feature near the grounding line implies that the subglacial water repeatedly flows from the region above the trunk to the KIS grounding line and out beneath the Ross Ice Shelf. Ice shelf elevation near the hypothesized outlet is observed to decrease slowly during the study period. Our finding supports a previously published conceptual model of the KIS shutdown stemming from a transition from distributed flow to well-drained channelized flow of subglacial water. However, a water-piracy hypothesis in which the KIS subglacial water system is being starved by drainage in adjacent ice streams is also supported by the fact that the degree of KIS trunk subglacial lake activity is relatively weaker than those of the upstream lakes.OAIID:RECH_ACHV_DSTSH_NO:T201501631RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A079127CITE_RATE:4.906FILENAME:2016_Kim_TC.pdfDEPT_NM:지구과학교육과EMAIL:[email protected]_YN:YFILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/0f782ccb-87d7-4af5-89fc-9ed5599fd0f7/linkCONFIRM:
Relationship Between Earlobe Crease and Brachial-ankle Pulse Wave Velocity in Non-hypertensive, Non-diabetic Adults in Korea
OBJECTIVES: Several studies have found a significant association between the presence of earlobe crease (ELC) and cardiovascular disease (CVD). Brachial-ankle Pulse Wave Velocity (baPWV) is a non-invasive and useful measure of arterial stiffness predicting cardiovascular events and mortality. However, few studies have reported the relationship between ELC and baPWV as a new measure of arterial stiffness. the purpose of this study was to determine whether ELC is related to baPWV in non-diabetic, non-hypertensive, and apparently healthy Korean adults.
METHODS: A cross-sectional study was conducted on 573 non-hypertensive, non-diabetic Korean adults aged 20-80 yr. Subjects were stratified into three groups according to gender and menopausal status. baPWV was measured by an automatic waveform analyser. the association between ELC and baPWV was assessed by multiple linear regression analysis after adjusting for conventional cardiovascular disease risk factors including age, gender, blood pressure, lipid profile, and smoking status etc.
RESULTS: the overall frequency of ELC was 19.02% and the subjects with ELC showed significantly higher mean baPWV (p<0.0001). Multiple linear regression of subjects revealed that the presence of ELC was independently associated with baPWV (male, p<0.0001; premenopausal female p=0.0162; postmenopausal female p=0.0208).
CONCLUSION: ELC had a significant correlation with baPWV, independently controlling for other classical cardiovascular risk factors in adults aged 20 yr or older. ELC is an important surrogate marker of increased arterial stiffness as measured by baPWV in Korean adults.ope
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