Role of anion exchangers in Cl- and HCO3- secretion by the human airway epithelial cell line Calu-3

Despite the importance of airway surface liquid pH in the lung's defenses against infection, the mechanism of airway HCO3- secretion remains unclear. Our aim was to assess the contribution of apical and basolateral Cl-/HCO3- exchangers to Cl- and HCO3- transport in the Calu-3 cell line, derived from human airway submucosal glands. Changes in intracellular pH (pH(i)) were measured following substitution of Cl- with gluconate. Apical Cl- substitution led to an alkalinization in forskolin-stimulated cells, indicative of Cl-/HCO3- exchange. This was unaffected by the anion exchange inhibitor DIDS but inhibited by the CFTR blocker CFTRinh-172, suggesting that the HCO3- influx might occur via CFTR, rather than a solute carrier family 26 (SLC26) exchanger, as recently proposed. The anion selectivity of the recovery process more closely resembled that of CFTR than an SLC26 exchanger, and quantitative RT-PCR showed only low levels of SLC26 exchanger transcripts relative to CFTR and anion exchanger 2 (AE2). For pHi to rise to observed values (similar to 7.8) through HCO3- entry via CFTR, the apical membrane potential must reverse to at least + 20 mV following Cl- substitution; this was confirmed by perforated-patch recordings. Substitution of basolateral Cl- evoked a DIDS-sensitive alkalinization, attributed to Cl-/HCO3- exchange via AE2. This appeared to be abolished in forskolin-stimulated cells but was unmasked by blocking apical efflux of HCO3- via CFTR. We conclude that Calu-3 cells secrete HCO3- predominantly via CFTR, and, contrary to previous reports, the basolateral anion exchanger AE2 remains active during stimulation, providing an important pathway for basolateral Cl- uptake

The Mechanism of Bicarbonate Secretion in Human Airway Epithelial Cell

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Observation of Atmospheric Water Vapors Using AIRS

The Atmospheric Infrared Sounder (AIRS) aboard the Aqua satellite, which is one of the Earth Observing System satellites managed by National Aeronautics and Space Administration, provides global measurements of the water vapor in the atmosphere using infrared (IR) channels. In this paper, we restored precipitable water vapor (PWV) over a permanent GPS station in Incheon using the IR measurements of AIRS and compared the result with GPS-based PWV estimates. As a result, AIRS PWV had similar trends with GPS PWV; the bias of AIRS PWV against GPS PWV is 0.3 cm and root mean square error (RMSE) 0.7 cm. In addition, the correlation coefficient between AIRS PWV and GPS PWV was 0.89. Thus we conclude that the AIRS PWV reflects local characteristics of the water vapor content

Self-Assembly of Poly(3-dodecylthiophene)-block-poly(methylmethacrylate)Copolymers Driven by Competition between Microphase Separation and Crystallization

We synthesized, via anionic coupling reaction, poly(3-dodecylthiophene)-block-poly(methyl methacrylate) copolymers (P3DDT-b-PMMA) having narrow molecular weight distribution and several block compositions. P3DDT was chosen because of moderate rod/rod interaction compared with a weak interaction of poly(3-(2'-ethyl)-hexylthiophene) (P3EHT) or a strong interaction of poly(3-hexylthiophene) (P3HT). The moderate rod/rod interaction of P3DDT enables us to investigate final morphologies affected by crystallization arising from the rod/rod interaction of P3DDT or the microphase separation between P3DDT and PMMA blocks. When the weight fraction (w(P3DDT)) of P3DDT block of P3DDT-b-PMMAs was smaller than similar to 0.6, various microdomains such as body-centered-cubic spheres, hexagonally packed cylinders, and lamellae were observed similar to those reported in conventional coil coil type block copolymers. Interestingly, these microdomains were maintained even after P3DDT blocks were crystallized, indicating that P3DDT crystals were successfully confined within P3DDT microdomains. On the other hand, when W-P3DDT was high (e.g., W-P3DDT similar to 0.76), the rod/rod interaction became dominant over microphase separation between two blocks. As a result, only fibril structure was found after the crystallization of P3DDT block.X113025sciescopu

Validation of the Atmospheric Infrared Sounder Water Vapor Retrievals Using Global Positioning System: Case Study in South Korea

The atmospheric infrared sounder (AIRS) sensor loaded on the Aqua satellite observes the global vertical structure of atmosphere and enables verification of the water vapor distribution over the entire area of South Korea. In this study, we performed a comparative analysis of the accuracy of the total precipitable water (TPW) provided as the AIRS level 2 standard retrieval product by Jet Propulsion Laboratory (JPL) over the South Korean area using the global positioning system (GPS) TPW data. The analysis TPW for the period of one year in 2008 showed that the accuracy of the data produced by the combination of the Advanced Microwave Sounding Unit sensor with the AIRS sensor to correct the effect of clouds (AIRS-X) was higher than that of the AIRS IR-only data (AIRS-I). The annual means of the root mean square error with reference to the GPS data were 5.2 kg/m2 and 4.3 kg/m2 for AIRS-I and AIRS-X, respectively. The accuracy of AIRS-X was higher in summer than in winter while measurement values of AIRS-I and AIRS-X were lower than those of GPS TPW to some extent

Multi-scale gabor feature based eye localization

Abstract—Eye localization is necessary for face recognition and related application areas. Most of eye localization algorithms reported so far still need to be improved about precision and computational time for successful applications. In this paper, we propose an eye location method based on multi-scale Gabor feature vectors, which is more robust with respect to initial points. The eye localization based on Gabor feature vectors first needs to constructs an Eye Model Bunch for each eye (left or right eye) which consists of n Gabor jets and average eye coordinates of each eyes obtained from n model face images, and then tries to localize eyes in an incoming face image by utilizing the fact that the true eye coordinates is most likely to be very close to the position where the Gabor jet will have the best Gabor jet similarity matching with a Gabor jet in the Eye Model Bunch. Similar ideas have been already proposed in such as EBGM (Elastic Bunch Graph Matching). However, the method used in EBGM is known to be not robust with respect to initial values and may need extensive search range for achieving the required performance, but extensive search ranges will cause much more computational burden. In this paper, we propose a multi-scale approach with a little increased computational burden where one first tries to localize eyes based on Gabor feature vectors in a coarse face image obtained from down sampling of the original face image, and then localize eyes based on Gabor feature vectors in the original resolution face image by using the eye coordinates localized in the coarse scaled image as initial points. Several experiments and comparisons with other eye localization methods reported in the other papers show the efficiency of our proposed method

Self-Assembly of Poly(3-dodecylthiophene)-<i>block</i>-poly(methyl methacrylate) Copolymers Driven by Competition between Microphase Separation and Crystallization

We synthesized, via anionic coupling reaction, poly­(3-dodecylthiophene)-<i>block</i>-poly­(methyl methacrylate) copolymers (P3DDT-<i>b</i>-PMMA) having narrow molecular weight distribution and several block compositions. P3DDT was chosen because of moderate rod/rod interaction compared with a weak interaction of poly­(3-(2′-ethyl)­hexylthiophene) (P3EHT) or a strong interaction of poly­(3-hexylthiophene) (P3HT). The moderate rod/rod interaction of P3DDT enables us to investigate final morphologies affected by crystallization arising from the rod/rod interaction of P3DDT or the microphase separation between P3DDT and PMMA blocks. When the weight fraction (<i>w</i>_P3DDT) of P3DDT block of P3DDT-<i>b</i>-PMMAs was smaller than ∼0.6, various microdomains such as body-centered-cubic spheres, hexagonally packed cylinders, and lamellae were observed similar to those reported in conventional coil–coil type block copolymers. Interestingly, these microdomains were maintained even after P3DDT blocks were crystallized, indicating that P3DDT crystals were successfully confined within P3DDT microdomains. On the other hand, when <i>w</i>_P3DDT was high (e.g., <i>w</i>_P3DDT ∼ 0.76), the rod/rod interaction became dominant over microphase separation between two blocks. As a result, only fibril structure was found after the crystallization of P3DDT block

Hierarchically Well-Ordered Array of Concentric Silver Nanorings for Highly Sensitive Surface -Enhanced Raman Scattering Substrate

We fabricated a high density array of concentric silver nanorings in a large area (over in.(2)) with uniform gap distance by utilizing half onion-shaped micro domains prepared by symmetric polystyrene-block-poly(methyl methacrylate) copolymers (PS-b-PMMA) confined within hemispherical cavities in anodized aluminum oxide (AAO) template. Silver nanoparticles with 6 nm height were selectively deposited only on the PS microdomains by thermal evaporation. The gap distance of two neighboring silver nanorings was controlled from 12 to 24 nm by changing the total molecular weight of PS-b-PMMAs. The substrate showed high surface-enhanced Raman scattering (SERS) enhancement factor as high as 4.3 x 10(7) with good reproducibility (+/-7%). It could be used for biosensing, detection of trace-level explosive and hazardous chemicals, and reaction monitoring.X11109sciescopu