The dynamics of thermally stimulated surface fluctuations of 100 nm thick films of long-branched polymers are measured for the first time. In contrast to comparable films of linear or cyclic chains that show no change in viscosity upon confinement, films of 6-pom, 6-star, and 6-end end-branched stars show viscosities, inferred from x-ray photon correlation spectroscopy, as much as 100 times higher than in the bulk. This difference varies in magnitude with chain architecture. Branching has a profound effect on confinement, even for these unentangled chains.
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http://dx.doi.org/10.1103/PhysRevLett.111.068303 | DOI Listing |
Chemphyschem
January 2025
Department of Physics, Yingbin Road 688, Jinhua, CHINA.
Undesirable loss of open-circuit voltage and current of metal halide perovskite (MHP) solar cells are closely associated with defects, so theoretical calculations have been often performed to scrutinize the nature of defects in bulk of MHPs. Yet, exploring the properties of defects at surfaces of MHPs is severely lacking given the complexity of the surface defects with high concentrations. In this study, IPb (PbI) antisite defects, namely one Pb (I) site being occupied by one I (Pb) atom at the surfaces of the FAPbI3 (FA = CH(NH2)2) material, are found to create electron (hole) traps when the surfaces with IPb (PbI) antisite defects are negatively (positively) charged.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China.
Developing switchable and multifunctional metasurfaces is essential for high-integration photonics. However, most previous studies encountered challenges such as limited degrees of freedom, simple tuning of predefined functionality, and complicated control systems. Here, we develop a general strategy to construct switchable and multifunctional metasurfaces.
View Article and Find Full Text PDFAnn Thorac Surg Short Rep
June 2024
Department of Pediatric Cardiovascular Surgery, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan.
The endocardial anchoring technique is a novel modification of total anomalous pulmonary venous return repair that involves creation of an L-shaped flap of the pulmonary venous confluence, subsequently anchoring it to the endocardium. A wide and smooth pathway can be expected from the theoretical advantages of this technique, namely, a smooth inner surface of the anchored flap and traction force to extend the orifice of the connection. An application of this technique for a rare variant of supracardiac total anomalous pulmonary venous return suggests its potential to be an alternative to the conventional repair, especially in patients with a curved pulmonary venous confluence.
View Article and Find Full Text PDFEur Heart J Cardiovasc Imaging
January 2025
Department of Radiology, UZ Leuven, Leuven, Belgium.
Aims: Atrial septal defect (ASD) and partial abnormal pulmonary venous connection (PAPVC) are noncyanotic congenital heart defects (CHD) that produce a left-to-right shunt. This single-center retrospective study aimed to assess the hemodynamic impact of isolated ASD, isolated PAPVC, and ASD-associated PAPVC using cardiovascular magnetic resonance (CMR).
Methods And Results: From our CMR registry (2002-2024), 110 patients were included: isolated ASD (n=64), isolated PAPVC (n=18), ASD-associated PAPVC (n=28, mostly sinus venosus septal defects).
Anal Chem
January 2025
Department of Earth and Environmental Sciences, University of Texas at Arlington, Arlington, Texas 76019, United States.
Fluorescence fluctuation spectroscopy experiments were conducted to better understand the complex mass transport dynamics of organic molecules in liquid-filled nanoporous media. Anodic aluminum oxide (AAO) membranes incorporating 10 and 20 nm diameter cylindrical pores were employed as model materials. Nile red (NR) dye was used as a fluorescent tracer.
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