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We present bidirectional, asymmetric interlocking behaviors between tilted micro- and nanohair arrays inspired from the actual wing locking device of beetles. The measured shear adhesion force between two identical tilted microhair arrays (1.5 μm radius, 30 μm height) turned out to be higher in the reverse direction than that in the angled direction, suggesting that the directionality of beetle's microtrichia may play a critical role in preventing the elytra from shifting along the middle of insect body. Furthermore, we observed dramatic enhancement of shear adhesion using asymmetric interlocking of various nanohair arrays (tilting angle, δ < 40°). A maximum shear locking force of ∼60 N/cm(2) was measured for the nanohair arrays of 50 nm radius and 1 μm height with a hysteresis as high as ∼3. A simple theoretical model was developed to describe the measured asymmetric adhesion forces and hysteresis, in good agreement with the experimental data.
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http://dx.doi.org/10.1021/am3009289 | DOI Listing |
Confl Health
July 2025
ARQ International, ARQ National Psychotrauma Centre, Diemen, the Netherlands.
Background: Urban refugees face systemic disadvantages that significantly impact their mental health and overall wellbeing. Research on refugee mental health often examines risk factors in isolation, overlooking broader systemic patterns. This study applies a structural injustice framework to investigate how interconnected disadvantages shape the mental health of urban refugees.
View Article and Find Full Text PDFJ Am Chem Soc
June 2025
Department of Applied Chemistry, School of Chemistry and Materials Science, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
Iodine-based batteries have emerged prominently in grid energy storage due to their cost-effectiveness and versatility. However, traditional iodine cathodes featuring I/I mechanisms struggle to meet the current demands for high-energy-density batteries, considering their limited specific capacity and voltage. Here, we discover a unique eight-electron-transfer asymmetric three-stage conversion of iodine facilitated by the formation of interhalogens.
View Article and Find Full Text PDFChemistry
May 2025
Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi'an, 710127, China.
Rotaxanes, belonging to the class of classical mechanically interlocked molecules (MIMs), exhibit chiral properties that diverge from those of traditional chiral elements, particularly displaying mechanically planar chirality. Their distinctive spatial structure further augments their chiral significance, thereby imparting them with vast potential for applications in the realm of chiral materials and asymmetric catalysis. In recent years, mechanically planar chiral rotaxanes have garnered increasing attention from researchers.
View Article and Find Full Text PDFJ Vis Exp
March 2025
Program in Occupational Therapy, Washington University School of Medicine;
Numerous methods exist to assess hand and arm function after upper extremity peripheral nerve injury, but peripheral injuries are often unilateral, and few existing methods are designed to capture the unique consequences of unilateral injury. Unilateral impairment of an upper extremity can lead to increased or decreased use of the dominant hand, and either change may be adaptive or maladaptive depending on the individual patient's needs. To identify atypical hand usage (left/right choices), researchers and clinicians need to measure it.
View Article and Find Full Text PDFAdv Sci (Weinh)
July 2025
Department of Colorectal Surgery, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Medical Innovation Technology Transformation Center of Shenzhen Second People's Hospital, Shenzhen University, Shenzhen, 518035, P. R. China.
Well-integration of multiple bioactive components into a biological patch without damaging its cellular matrix structure is crucial for infectious abdominal wall defect repair but remains challenging. Herein, a novel asymmetric biological composite patch (bPVA/SIS-NP) is developed by in situ introducing zwitterionic polyvinyl alcohol molecular brush (bPVA) hydrogel to a cationic small intestinal submucosal decellularized matrix (SIS) via a self-induced phase separation based united strategy. Due to its high hydrogen bonding crosslinking and strong mechanical interlocking with SIS-NP layer, bPVA layer can maintain stable anti-contamination and the corresponding anti-adhesion properties in the contaminated environment.
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