Mechanical Self-Assembly of a Strain-Engineered Flexible Layer: Wrinkling, Rolling, and Twisting

Self-shaping of curved structures, especially those involving flexible thin layers, has attracted increasing attention because of their broad potential applications in e.g. nanoelectromechanical/micro-electromechanical systems (NEMS/MEMS), sensors, artificial skins, stretchable electronics, robotics, and drug delivery. Here, we provide an overview of recent experimental, theoretical, and computational studies on the mechanical self-assembly of strain-engineered thin layers, with an emphasis on systems in which the competition between bending and stretchingenergy gives rise to a variety ofdeformations,such as wrinkling, rolling, and twisting. We address the principle of mechanical instabilities, which is often manifested in wrinkling or multistability of strain-engineered thin layers. The principles of shape selection and transition in helical ribbons are also systematically examined. We hope that a more comprehensive understanding of the mechanical principles underlying these rich phenomena can foster the development of new techniques for manufacturing functional three- dimensional structures on demand for a broad spectrum of engineering applications.Comment: 91 pages, 35 figures, review articl

Analysis of beauvericin in Isaria cicadae Miquel culture on different media

Objective To analyze beauvericin and enniatins concentrations in the culture complex after Isaria cicadae Miquel was inoculated on different media for certain time. Methods One strain of Isaria cicadae Miquel was inoculated on 4 kinds of liquid culture media and 4 kinds of solid culture media. After incubation for 1-7 weeks under 25 ℃, high performance liquid chromatography tandem mass spectrometry was employed to detect beauvericin and enniatins. Results The detection rates of beauvericin in Isaria cicadae Miquel culture on 4 kinds of liquid media ranged between 42.9%-100.0%, and the beauvericin concentrations varied from 1.0 to 94.6 μg/L. The positive rates of beauvericin in Isaria cicadae Miquel culture on 4 kinds of solid media were 100.0%, and the beauvericin concentrations ranged from 60.9 to 44 677.5 μg/kg. Enniatins were negative for Isaria cicadae Miquel on 8 kinds of culture media. Conclusion The strain of Isaria cicadae Miquel used in our study could produce beauvericin in 8 kinds of culture media after incubation for certain time, and the beauvericin concentrations in solid media were much higher than in liquid media. The strain of Isaria cicadae Miquel didn’t produce enniatins in 8 kinds of culture media after incubation for certain time

An All-Solid-State Phosphate Electrode with H3PO4 Doped Polyaniline as the Sensitive Layer

We here describe the construction of a highly sensitive and selective all-solid-state phosphate electrode based on polyaniline and H3PO4 doped polyaniline. The polyaniline layer was electroplated on the gold substrate with Chronoamperometry method and was in-situ doped by H3PO4. The Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM, EDS) and contact angle measurement was taken to explain the difference of the two layers. This electrode can be used in both freshwater and seawater systems. In both of the two systems, the electrode exhibits linear response in the concentration range 10-1 to 10-6 M with detection limit of 10-6 M. and response time of <1 seconds. The selectivity of the electrodes was also studied in 10-1-10-5 M KH2PO4 solutions containing either 0.01 M sulfate, nitrate, chloride as the interference ions. During 12 hours continuous monitoring in 10-3 M KH2PO4 with 3.5% NaCl the potential drift was 0.05 mV/h and the lifetime of the electrode was over 40 days when preserved in this solutionpublishersversionPeer reviewe

Interventional Treatment of Endometriosis

Patients with endometriosis and adenomyosis naturally improve after menopause. Therefore, some patients only need to relieve symptoms, especially those near menopause, and they prefer to be treated by conservative methods. We summarized several minimally invasive interventional methods: uterine artery intervention (Uterine artery embolization, UAE), nerve intervention (upper and lower abdominal plexus block, SHPB), ultrasound intervention (puncture sclerotherapy; high intensity focused ultrasound treatment)

Atomic-number dependence of the magnetic-sublevel population in the autoionization state formed in dielectronic recombination

The magnetic-sublevel population of the autoionization state formed in dielectronic recombination (DR) of highly charged heavy ions has been experimentally investigated by combining two types of measurements with an electron beam ion trap. The two different measurements are the differential x-ray measurement at 90∘ with respect to the electron beam and the integral resonance-strength measurement. The alignment parameter, which denotes the magnetic-sublevel population distribution, has been obtained for the autoionization states [1s2s22p1/2]1 formed in DR of Li-like Pr (atomic number Z=59) and Ho (Z=67). This work is a complement to our previous work [Phys. Rev. Lett. 108, 073002 (2012)] on Li-like Au (Z=79). The experimental results are in reasonable agreement with theoretical predictions, and a strong Z-dependent tendency due to the Breit interaction has been confirmed

Constructing Heterostructure through Bidentate Coordination toward Operationally Stable Inverted Perovskite Solar Cells

It has been reported that one of the influencing factors leading to stability issues in iodine-containing perovskite solar cells is the iodine loss from the perovskite layer. Herein, bidentate coordination is used with undercoordinated I− of the perovskite surface to construct the stable perovskite-based heterostructure. This strong halogen bonding effectively inhibits interfacial migration of I− into functional layers such as C60 and Ag. Moreover, passivation of the undercoordinated I− suppresses the release of I2 and further delays the formation of voids at the perovskite surface. The resulting inverted perovskite solar cell exhibits a power conversion efficiency of 22.59% and the unencapsulated device maintains 96.15% of its initial value after continuous operation for 500 h under illumination.journal articl

Conformal Three-Dimensional Interphase of Li Metal Anode Revealed by Low Dose Cryo-Electron Microscopy

Using cryogenic transmission electron microscopy, we revealed three dimensional (3D) structural details of the electrochemically plated lithium (Li) flakes and their solid electrolyte interphase (SEI), including the composite SEI skin-layer and SEI fossil pieces buried inside the Li matrix. As the SEI skin-layer is largely comprised of nanocrystalline LiF and Li2O in amorphous polymeric matrix, when complete Li stripping occurs, the compromised SEI three-dimensional framework buckles, forming nanoscale bends and wrinkles. We showed that the flexibility and resilience of the SEI skin-layer plays a vital role in preserving an intact SEI 3D framework after Li stripping. The intact SEI network enables the nucleation and growth of the newly plated Li inside the previously formed SEI network in the subsequent cycles, preventing additional large amount of SEI formation between newly plated Li metal and the electrolyte. In addition, cells cycled under the accurately controlled uniaxial pressure can further enhance the repeated utilization of the SEI framework and improve the coulombic efficiency (CE) by up to 97%, demonstrating an effective strategy of reducing the formation of additional SEI and inactive dead Li. The identification of such flexible and porous 3D SEI framework clarifies the working mechanism of SEI in lithium metal anode for batteries. The insights provided in this work will inspire researchers to design more functional artificial 3D SEI on other metal anodes to improve rechargeable metal battery with long cycle life

Clarifying the mechanisms of the light-induced color formation of apple peel under dark conditions through metabolomics and transcriptomic analyses

Many studies have demonstrated that anthocyanin synthesis in apple peel is induced by light, but the color of bagged apple peel continues to change under dark conditions after light induction has not been characterized. Here, transcriptional and metabolic changes associated with changes in apple peel coloration in the dark after different light induction treatments were studied. Apple pericarp can achieve a normal color under complete darkness followed by light induction. Metabolomics analysis indicated that the expression levels of cyanidin-3-O-galactoside and cyanidin-3-O-glucoside were high, which might be associated with the red color development of apple peel. Transcriptome analysis revealed high expression levels of MdUFGTs, MdMYBs, and MdNACs, which might play a key role in light-induced anthocyanin accumulation under dark conditions. 13 key genes related to dark coloring after light induction was screened. The results of this study provide new insights into the mechanism of anthocyanin synthesis under dark conditions

Comparison of riboflavin/ultraviolet-A cross-linking in porcine, rabbit, and human sclera

. Purpose. To compare the biomechanical properties of porcine, rabbit, and human sclera before and after riboflavin/ultraviolet-A (UVA) collagen cross-linking (CXL). Methods. Eight rabbits, 8 porcine eyeballs, and 8 human eyeballs were included. One rabbit eye and half of each bisected human and porcine eyeball were treated with riboflavin/UVA CXL. Untreated fellow rabbit eyes and eyeball halves served as controls. A 10 mm × 20 mm scleral band was harvested from each specimen. From this band, two 3.5 mm × 15.0 mm strips were prepared for biomechanical testing. The biomechanical parameters were ultimate stress, stress and Young&apos;s modulus. Results. Values of stress, and Young&apos;s modulus showed that human sclera was 4 times stiffer than porcine sclera and 3 times stiffer than rabbit sclera. In rabbit sclera, both the stress and Young&apos;s modulus were significantly increased by CXL ( &lt; 0.05). In porcine sclera, only the ultimate stress was significantly increased by CXL ( &lt; 0.05). The biomechanical properties of human sclera were not statistically affected by CXL ( &gt; 0.05). Conclusions. Human sclera has higher biomechanical stiffness than porcine and rabbit sclera. With the same irradiation dose, riboflavin/UVA CXL increases the biomechanical stiffness of rabbit sclera but not porcine or human sclera