The use of helical hexapeptides to establish a surface dipole layer on a TiO substrate, with the goal of influencing the energy levels of a coadsorbed chromophore, is explored. Two helical hexapeptides, synthesized from 2-amino isobutyric acid (Aib) residues, were protected at the N-terminus with a carboxybenzyl group (Z) and at the C-terminus carried either a carboxylic acid or an isophthalic acid (Ipa) anchor group to form Z-(Aib)-COOH or Z-(Aib)-Ipa, respectively. Using a combination of vibrational and photoemission spectroscopies, bonding of the two peptides to TiO surfaces (either nanostructured or single-crystal TiO(110)) was found to be highly dependent on the anchor group, with Ipa establishing a monolayer much more efficiently than COOH. Furthermore, a monolayer of Z-(Aib)-Ipa on TiO(110) was exposed for different binding times to a solution of a zinc tetraphenylporphyrin (ZnTPP) derivative terminated with an Ipa anchor group (ZnTPP-P-Ipa). Photoemission spectroscopy revealed that ZnTPP-P-Ipa partly displaced Z-(Aib)-Ipa, forming a coadsorbed monolayer on the oxide surface. The presence of the peptide molecular dipole shifted the HOMO levels of the ZnTPP group to lower energy by ∼300 meV, in accordance with a simple parallel plate capacitor model. These results suggest that a mixed-layer approach, involving coadsorption of a strong molecular dipole compound with a chromophore, is a versatile method to shift the energy levels of such chromophores with respect to the band edges of the substrate.
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Am J Orthod Dentofacial Orthop
January 2025
Department of Orthodontics, Bauru Dental School, University of São Paulo, Bauru, Brazil.
Introduction: The objective of this study was to compare the dental and skeletal changes promoted by the miniscrew-anchored cantilever and pendulum appliance for Class II correction.
Methods: This retrospective study involved 52 patients with Class II malocclusion divided into 2 groups according to the treatment received: the miniscrew group (MG) with 23 patients (14 females and 9 males; mean initial age of 12.42 years) treated using the miniscrew-anchored cantilever, and the pendulum group (PG) with 29 patients (21 females and 8 males; mean initial age of 13.
JACC Heart Fail
January 2025
The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
Background: Left ventricular (LV) dilatation and extensive scar portend a poor prognosis in heart failure (HF). The Revivent TC system (BioVentrix Inc) is used either during a hybrid transcatheter-surgical or a surgical-only procedure to exclude transmural scar and reduce LV dimensions.
Objectives: The purpose of this study was to examine the safety and efficacy of the Revivent TC® anchor system in patients with HF.
Am J Sports Med
January 2025
Rothman Orthopaedic Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
Background: Arthroscopic labral repair of the hip is successfully performed with increasing frequency using either knotless or knotted suture anchors, each with its own risks and benefits.
Purpose: To examine biomechanical and clinical outcomes for labral repair of the hip based on the use of knotted or knotless suture anchors.
Study Design: Systematic review; Level of evidence, 4.
Adv Mater
January 2025
Liquid Crystals and Photonics Group, Department of Electronics and Information Systems, Ghent University, Technologiepark-Zwijnaarde 126, Ghent, 9052, Belgium.
In liquid crystal (LC) cells, the surface patterning directs the self-assembly of the uniaxial building blocks in the bulk, enabling the design of stimuli-response optical devices with various functionalities. The combination of different anchoring patterns at both substrates can lead to surface induced frustration, preventing a purely planar and defect-free configuration. In cells with crossed assembly of rotating anchoring patterns, elastic deformations allow to obtain a defect-free bulk configuration, but an electrical stimulus can induce disclination lines.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Department of Chemistry, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
The effect of solution pH on the formation and surface structure of 2-pyrazinethiolate (2-PyzS) self-assembled monolayers (SAMs) formed by the adsorption of 2-mercaptopyrazine (2-PyzSH) on Au(111) was investigated using scanning tunneling microscopy (STM) and X-ray photoelectron microscopy (XPS). Molecular-scale STM observations clearly revealed that 2-PyzS SAMs at pH 2 had a short-range ordered phase of (2√3 × √21)R30° structure with a standing-up adsorption structure. However, 2-PyzS SAMs at pH 8 had a very unique long-range ordered phase, showing a "ladder-like molecular arrangement" with bright repeating rows.
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