Comparison of the Plasma Metabolome Profiles Between the Internal Thoracic Artery and Ascending Aorta in Patients Undergoing Coronary Artery Bypass Graft Surgery Using Gas Chromatography Time-of-Flight Mass Spectrometry.

BackgroundThe left internal thoracic artery (LITA) has been used as the first conduit of choice in coronary artery bypass grafting (CABG) because of excellent long-term patency and outcomes. However, no studies have examined substances other than nitric oxide that could be beneficial for the bypass conduit, native coronary artery or ischemic myocardium. This study was conducted to evaluate differences in metabolic profiles between the LITA and ascending aorta using gas chromatography-time of flight-mass spectrometry (GC-TOF-MS).MethodsTwenty patients who underwent CABG using the LITA were prospectively enrolled. Plasma samples were collected simultaneously from the LITA and ascending aorta. GC-TOF-MS based untargeted metabolomic analyses were performed and a 2-step volcano plot analysis was used to identify distinguishable markers from two plasma metabolome profiles. Semi-quantitative and quantitative analyses were performed using GC-TOF-MS and enzyme-linked immunosorbent assay, respectively, after selecting target metabolites based on the metabolite set enrichment analysis.ResultsInitial volcano plot analysis demonstrated 5 possible markers among 851 peaks detected. The final analysis demonstrated that the L-cysteine peak was significantly higher in the LITA than in the ascending aorta (fold change = 1.86). The concentrations of intermediate metabolites such as L-cysteine, L-methionine and L-cystine in the 'cysteine and methionine metabolism pathway' were significantly higher in the LITA than in the ascending aorta (2.0-, 1.4- and 1.2-fold, respectively). Quantitative analysis showed that the concentration of hydrogen sulfide (H₂S) was significantly higher in the LITA.ConclusionThe plasma metabolome profiles of the LITA and ascending aorta were different, particularly higher plasma concentrations of L-cysteine and H₂S in the LITA

Routes for efficiency enhancement in fluorescent TADF exciplex host OLEDs gained from an electro‐optical device model

Fluorescence-based organic light-emitting diodes (OLEDs) using thermally activated delayed fluorescence (TADF) have increasingly attracted attention in research and industry. One method to implement TADF is based on an emitter layer composed of an exciplex host and a fluorescent dopant. Even though the experimental realization of this concept has demonstrated promising external quantum efficiencies, the full potential of this approach has not yet been assessed. To this end, a comprehensive electro-optical device model accounting for the full exciton dynamics including triplet harvesting and exciton quenching is presented. The model parameters are fitted to multiple output characteristics of an OLED comprising a TADF exciplex host with a fluorescent emitter, showing an external quantum efficiency of >10%. With the model at hand, an emission zone analysis and a parameter study are performed, and possible routes for further efficiency enhancement are presented

Fabrication of multimode polymeric waveguides and micromirrors using deep x-ray lithography

Multimode polymeric waveguides and 45° micromirrors have been fabricated using deep X-ray lithography. Polymethylmetacrylate was used as a core layer and silica and silicone elastomer as a lower and upper cladding layer, respectively. The propagation loss of the waveguide was 0.54 dB/cm at 830 nm and the loss of micromirrors was less than 0.43 dB at the wavelength. The X-ray lithography technique offers the controllability of mirror angles to 45° and -45° so that it gives flexibility to the system architecture of optical interconnections

Stacked Polymeric Multimode Waveguide Arrays for Two-Dimensional Optical Interconnects

Two-dimensional (2-D) polymeric multimode waveguide arrays with two reflection-mirrors have been fabricated for optical interconnects between 2-D arrayed vertical-cavity surface-emitting lasers and detectors. Contact printing lithography was adopted for simple and low-cost process using ultraviolet-curable epoxy-based polymers. Fabricated waveguides were diced of the same size and stacked one by one with lateral positional errors less than ±20 μm. Two kinds of mirrors were fabricated: single-reflection mirror and double-reflection mirror. Double-reflected mirrors resulted in lower losses with 1.2 dB than single reflected mirrors with 2.1 dB. The average insertion losses of 16-channel arrayed waveguides with two single-reflection mirrors and with two double-reflection-mirrors were measured to be 6.1 and 4.4 dB for 6-cm-long waveguides at a wavelength of 830 nm, respectively. The crosstalk between the waveguides was less than -25 dB. The characteristics of the waveguide arrays are good enough for applications to optical interconnects.This work was supported by the Ministry of Commerce, Industry and Energy and by the BK 21 program

The role of small bowel endoscopy in small bowel Crohn's disease: when and how?

Endoscopy has a crucial role in the diagnosis, management, and surveillance of inflammatory bowel disease (IBD). It contributes in supporting the diagnosis of IBD with the clinical history, physical examination, laboratory findings, and targeted biopsies. Furthermore, endoscopy has a significant role in assessing disease activity and distribution in treatment efficacy evaluation, post-surgical recurrence risk, and cancer surveillance in patients with long-lasting illness. Endoscopy also provides therapeutic potential for the treatment of IBD, especially with stricture dilatation and treatment of bleeding. Small bowel (SB) endoscopy (capsule endoscopy and device-assisted enteroscopy) and cross-sectional radiologic imaging (computed tomography enterography and magnetic resonance enterography) have become important diagnostic options to diagnose and treat patients with SB Crohn's disease. We reviewed the present role of SB endoscopy in patients with SB Crohn's disease