Several different self-assembling peptide systems that form nanofibers have been investigated as vaccine platforms, but design principles for adjusting the character of the immune responses they raise have yet to be well articulated. Here we compared the immune responses raised by two structurally dissimilar peptide nanofibers, one a β-sheet fibrillar system (Q11), and one an α-helical nanofiber system (Coil29), hypothesizing that integrated T-cell epitopes within the latter would promote T follicular helper (Tfh) cell engagement and lead to improved antibody titers and quality. Despite significantly different internal structures, nanofibers of the two peptides exhibited surprisingly similar nanoscale morphologies, and both were capable of raising strong antibody responses to conjugated peptide epitopes in mice without adjuvant. Both were minimally inflammatory, but as hypothesized Coil29 nanofibers elicited antibody responses with higher titers and avidities against a conjugated model epitope (OVA323-339) and a candidate peptide epitope for vaccination against S. aureus. Subsequent investigation indicated that Coil29 nanofibers possessed internal CD4+ T cell epitopes whereas Q11 nanofibers required co-assembly of additional CD4+ T cell epitopes to be immunogenic, Coil29 nanofibers did not. Coil29 nanofibers also raised stronger germinal center B cell responses and follicular helper T cell (Tfh) responses relative to Q11 nanofibers, likely facilitating the improvement of the antibody response. These findings illustrate design strategies for improving humoral responses raised by self-assembled peptide nanofibers.The photoelectron spectroscopy of CH2NC (isocyanomethyl) radical species is investigated for the first time between 9.3 and 11.2 eV in the vicinity of the first photoionizing transition X+1A1← X 2B1. https://www.selleckchem.com/products/hexamethonium-bromide.html The experiment combines a microwave discharge flow-tube reactor to produce the radicals through the CH3NC + F → CH2NC + HF reaction, a VUV synchrotron radiation excitation, and a double imaging electron/ion coincidence spectrometer which allows the recording of mass-selected threshold photoelectron spectra. Assignment of the observed vibrational structure of the CH2NC+ cation is guided by ab initio calculations and Franck-Condon simulations. From the experimental spectrum, the first adiabatic ionization energy of the CH2NC radical is measured as 9.439(6) eV. Fundamental wavenumbers are determined for several vibrational modes of the cation [small nu, Greek, tilde]1+(CH2 symmetric stretch) = 2999(80) cm-1, [small nu, Greek, tilde]2+(NC stretch) = 1925(40) cm-1, [small nu, Greek, tilde]4+(H2C-N stretch) = 1193(40) cm-1, [small nu, Greek, tilde]6+(CNC out-of-plane bend) = 237(50) cm-1, and [small nu, Greek, tilde]8+(CH2 rock) = 1185(60) cm-1.Besides commonly used graphite, carbon nanotubes are also often chosen as precursor materials for the synthesis of new carbon phases. Here we identify, using ab initio calculations, two new three-dimensional crystalline modifications of carbon nanotubes with P63/mcm (D36h) symmetry derived from (6,0) and (9,0) nanotubes via a three-fold distortion assisted reconstruction mechanism. The resulting sp2 + sp3 hybrid network structures have a 24- and 36-atom hexagonal unit cell, termed as (6,0)-hP24 and (9,0)-hP36 carbon, and they topologically correspond to two-dimensional graphyne and graphdiyne. Total-energy calculations show that they are energetically more stable than the original nanotubes and previously reported polymerized nanotube structures. Their dynamic stability has been confirmed by phonon mode analysis. Electronic band structure calculations reveal that they are semiconductors with an indirect band gap of 0.18 eV for hP24, and a direct band gap of 2.15 eV for hP36. The present results establish a new type of carbon phase and offer insights into understanding the complex structural landscape of polymerized nanotubes.The phase diagram of oxygen is investigated for pressures from 50 to 130 GPa and temperatures up to 1200 K using first-principles theory. A metallic molecular structure with the P63/mmc symmetry (η' phase) is determined to be thermodynamically stable in this pressure range at elevated temperatures above the ε(O8) phase. Crucial for obtaining this result is the inclusion of anharmonic lattice dynamics effects and accurate calculations of exchange interactions in the presence of thermal disorder. We present analysis of electronic, structural, and thermodynamic properties of solid oxygen at 0 K and finite temperature with hybrid exchange functionals, including a comparison with available experimental data.Background Throat packs are placed around the airway in patients undergoing upper airway surgical procedures under general anaesthetic to prevent aspiration or ingestion of blood, and consequent chest infections or postoperative nausea and vomiting (PONV). There is no definitive evidence for this, and each time a pack is placed, it risks being retained and obstructing the upper airway. This study aimed to determine whether throat packs are of benefit to patients undergoing upper airway surgical procedures. Methods Medline, Embase and Central were searched from conception to 15th January 2018 using individualised search strategies. A systematic search of multiple databases was undertaken using custom strategies to identify all relevant randomised controlled trials. Screening, risk of bias assessment and data extraction were undertaken independently by two authors. Primary outcomes included throat pain and PONV. Secondary outcomes included any adverse event documented. Results Thirteen papers were eligible for inclusion. No studies reported any instances of retained throat packs. Ten studies assessed the effect of throat packs on post-operative throat pain, with four papers showing a significantly higher incidence of pain when throat packs were used. One study showed throat pain to be slightly, but significantly, worse 24 hours post-surgery when a pack was not used. No paper showed throat packs to be of benefit in preventing PONV. Conclusion The study was limited by methodological flaws of included trials, overall relatively low numbers of patients and difficulty in contacting authors to clarify information and obtain raw data. However, this systematic review found no evidence to support the use of throat packs. This supports the proposal that there is no indication for the routine use of throat packs in ENT, maxillofacial and dental procedures.