Detection of coronary artery disease by magnetic resonance myocardial perfusion imaging with various contrast medium doses: first european multi-centre experience

Aims Magnetic resonance (MR) first-pass myocardial perfusion imaging during hyperaemia detects coronary artery stenoses in humans with test sensitivity depending on contrast medium (CM)-induced signal change in myocardium. In this prospective multi-centre study, the effect of CM dose on myocardial signal change and on diagnostic performance was evaluated using a stress-only approach. Methods and results Ninety-four patients with known or suspected coronary artery disease (CAD) were randomised to 0.05,0.10, or 0.15 mmol/kg body weight of an extravascular CM (Gd-DTPA) and X-ray coronary angiography was performed within 30 days prior/after the MR examination. A multi-slice MR technique with identical hardware and software in all centres was used during hyperaemia (adenosine 0.14 mg/kg/min) to monitor myocardial CM wash-in kinetics and data were analysed semi-automatically in a core laboratory. Protocol violations resulted in 80 complete studies with CAD (defined as ⩾1 vessel with diameter stenosis ⩾50% on quantitative coronary angiography) present in 19/29, 13/24, and 20/27 patients for doses 1, 2, and 3, respectively. In normal myocardium, the upslope increased with CM dose (overall-p<0.0001, ANOVA). For CAD detection the area under the receiver operator characteristics curve for subendocardial data (3 slices with quality score<4 representing 86% of cases) was 0.91±0.07 and 0.86±0.08 for doses 2 and 3, respectively, and was lower for dose 1 (0.53±0.13, p<0.01 and p<0.02 vs. doses 2 and 3, respectively). Corresponding sensitivities/specificities (95% confidence intervals) for pooled doses 2/3 were 93% (77-99%; ns vs. dose 1) and 75% (48-92%;p<0.05 vs. dose 1), respectively. Conclusions With increasing doses of CM, a higher signal response in the myocardium was achieved and consequently this stress-only protocol, with CM doses of 0.10-0.15 mmol/kg combined with a semi-automatic analysis, yielded a high diagnostic performance for the detection of CA

Chromatin features of plant telomeric sequences at terminal versus internal positions

Epigenetic mechanisms are involved in regulation of crucial cellular processes in eukaryotic organisms. Data on the epigenetic features of plant telomeres and their epigenetic regulation were published mostly for Arabidopsis thaliana, in which the presence of interstitial telomeric repeats (ITRs) may interfere with genuine telomeres in most analyses. Here, we studied the epigenetic landscape and transcription of telomeres and ITRs in Nicotiana tabacum with long telomeres and no detectable ITRs, and in Ballantinia antipoda with large blocks of pericentromeric ITRs and relatively short telomeres. Chromatin of genuine telomeres displayed heterochromatic as well as euchromatic marks, while ITRs were just heterochromatic. Methylated cytosines were present at telomeres and ITRs, but showed a bias with more methylation towards distal telomere positions and different blocks of B. antipoda ITRs methylated to different levels. Telomeric transcripts TERRA (G-rich) and ARRET (C-rich) were identified in both plants and their levels varied among tissues with a maximum in blossoms. Plants with substantially different proportions of internally and terminally located telomeric repeats are instrumental in clarifying the chromatin status of telomeric repeats at distinct chromosome locations

Noble metal -doped graphitic carbon nitride photocatalyst for enhancement photocatalytic decomposition of antibiotic pollutant in wastewater under visible light

This study the noble metal (Ag)-doped graphitic carbon nitride (g-C3N4) photocatalyst was synthesized via a facial thermal condensation method. The structure and surface elements distribution of synthesized materials were characterized using XRD, SEM, XPS, UV–vis and N2 adsorption-desorption experiment. The doping of Ag not only decreased the band-gap energy and particle size, but also enhanced the separation of charge carriers and decreased the electron/hole recombination in the g-C3N4 structure. The photocatalytic activity of Ag-doped g-C3N4 was investigated using oxytetracycline (OTC) as a model pollutant. The loading of 7% Ag onto g-C3N4 showed highest photocatalytic degradation efficiency of OT. The synthesized photocatalyst showed extremely high stability after 5 cycles as confirmed through various characterization techniques such as SEM and XRD. Eventually, several degradation intermediates of OTC were identified, and possible decomposition pathways were proposed. The 7-AgCN also was applied for the degradation of complex antibiotic wastewater, the removal efficiencies of OTC within 120 min was 98.7%. Overall, this work provides a novel strategy for the green synthesis of Ag-supportedg-C3N4, and its promising application prospect in environmental remediation.This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 104.05-2018.354 . Appendix AScopu