Additional file 1 of Giant unruptured sinus of Valsalva aneurysms causing angina pectoris

Supplementary Material

Helical 1:1 α/Sulfono-γ-AA Heterogeneous Peptides with Antibacterial Activity

As one of the greatest threats facing the 21st century, antibiotic resistance is now a major public health concern. Host-defense peptides (HDPs) offer an alternative approach to combat emerging multi-drug-resistant bacteria. It is known that helical HDPs such as magainin 2 and its analogs adopt cationic amphipathic conformations upon interaction with bacterial membranes, leading to membrane disruption and subsequent bacterial cell death. We have previously shown that amphipathic sulfono-γ-AApeptides could mimic magainin 2 and exhibit bactericidal activity. In this article, we demonstrate for the first time that amphipathic helical 1:1 α/sulfono-γ-AA heterogeneous peptides, in which regular amino acids and sulfono-γ-AApeptide building blocks are alternatively present in a 1:1 pattern, display potent antibacterial activity against both Gram-positive and Gram-negative bacterial pathogens. Small angle X-ray scattering (SAXS) suggests that the lead sequences adopt defined helical structures. The subsequent studies including fluorescence microscopy and time-kill experiments indicate that these hybrid peptides exert antimicrobial activity by mimicking the mechanism of HDPs. Our findings may lead to the development of HDP-mimicking antimicrobial peptidomimetics that combat drug-resistant bacterial pathogens. In addition, our results also demonstrate the effective design of a new class of helical foldamer, which could be employed to interrogate other important biological targets such as protein–protein interactions in the future

New Class of Heterogeneous Helical Peptidomimetics

A new class of unnatural heterogeneous foldamers is reported to contain alternative α-amino acid and sulfono-γ-AA amino acid residues in a 1:1 repeat pattern. Two-dimensional NMR data show that two 1:1 α/sulfono-γ-AA peptides with diverse side chains form analogous right-handed helical structures in solution. The effects of sequence length, side chain, N-capping, and temperature on folding propensity were further investigated using circular dichroism and small-angle X-ray scattering

Sustained Attention is Associated with Error Processing Impairment: Evidence from Mental Fatigue Study in Four-Choice Reaction Time Task

<div><p>Attention is important in error processing. Few studies have examined the link between sustained attention and error processing. In this study, we examined how error-related negativity (ERN) of a four-choice reaction time task was reduced in the mental fatigue condition and investigated the role of sustained attention in error processing. Forty-one recruited participants were divided into two groups. In the fatigue experiment group, 20 subjects performed a fatigue experiment and an additional continuous psychomotor vigilance test (PVT) for 1 h. In the normal experiment group, 21 subjects only performed the normal experimental procedures without the PVT test. Fatigue and sustained attention states were assessed with a questionnaire. Event-related potential results showed that ERN (p < 0.005) and peak (p < 0.05) mean amplitudes decreased in the fatigue experiment. ERN amplitudes were significantly associated with the attention and fatigue states in electrodes Fz, FC1, Cz, and FC2. These findings indicated that sustained attention was related to error processing and that decreased attention is likely the cause of error processing impairment.</p></div

PVT procedures.

<p>A fixation point was first presented for 400 ms. Then, each Arabic numeral was presented for 1,000 ms. Participants were asked to press the space key as soon as possible. The ISI was 1,000 ms to 3,000 ms.</p

Four-choice RT task procedures.

<p>First, a fixation point was presented for 350 ms. Then, each stimulus was presented for 3,000 ms. Participants were required to press the keys as soon as possible. The minimum ISI was 300 ms.</p

Helical Antimicrobial Sulfono-γ-AApeptides

Host-defense peptides (HDPs) such as magainin 2 have emerged as potential therapeutic agents combating antibiotic resistance. Inspired by their structures and mechanism of action, herein we report the first example of antimicrobial helical sulfono-γ-AApeptide foldamers. The lead molecule displays broad-spectrum and potent antimicrobial activity against multi-drug-resistant Gram-positive and Gram-negative bacterial pathogens. Time-kill studies and fluorescence microscopy suggest that sulfono-γ-AApeptides eradicate bacteria by taking a mode of action analogous to that of HDPs. Clear structure–function relationships exist in the studied sequences. Longer sequences, presumably adopting more-defined helical structures, are more potent than shorter ones. Interestingly, the sequence with less helical propensity in solution could be more selective than the stronger helix-forming sequences. Moreover, this class of antimicrobial agents are resistant to proteolytic degradation. These results may lead to the development of a new class of antimicrobial foldamers combating emerging antibiotic-resistant pathogens

ERN/CRN at electrodes Fz, Cz, FC1, and FC2 in the two experiments.

<p>(A) Response-locked averages for erroneous reactions in normal and fatigue experiments at electrodes Fz, Cz,FC1 and FC2. (B) Topographies for ERN and CRN at 40 ms post-response.(C) Topographies for ERN at 1–100 ms post-response.</p

Mean summary data for fatigue questionnaire subscales.

<p>Note: *p < 0.05,</p><p>**p < 0.01.</p><p>Mean summary data for fatigue questionnaire subscales.</p