How r-Plane Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Surface Modifications Impact the Growth of Epitaxial (001) CeO<Subscript>2</Subscript> Thin Films

We present evidence that it is the presence or absence of atomic terraces with a specific crystallographic orientation on the (102) Al₂O₃ surface that promotes growth of single-crystal (001) CeO₂ films over polycrystalline (111) CeO₂ films. The CeO₂ film nucleates so that the [010] and [100] directions of the film align parallel and perpendicular to the terrace edges. In the absence of terraces, multidomain (111) CeO₂ films result in which the in-plane orientation of the two domains are rotated by 85.71°, so that a [110] CeO₂ direction aligns parallel to either the or Al₂O₃ direction.     

多重转换：冗余电源系统电流限制的一种新方法

本文介绍了多重转换这一实现冗余电源系统电流限制的新方法,以及具体的解决方案--TPS2359.新型TPS2359热插拔控制器集成了两个AdvancedMC(AMC)模块的所有电源管理功能,其电流限制电路使得设计人员可以满足苛刻的AMC要求.这具有非常重要的意义,因为许多应用都使用了冗余电源.无论连接到负载的电源数量如何,一种称为多重转换的独特特性均可保持一个固定的电流限制.     

Significant Enhancement of Proton Transport in Bioinspired Peptide Fibrils by Single Acidic or Basic Amino Acid Mutation

Bioinspired materials are extremely suitable for the development of biocompatible and environmentally friendly functional materials. Peptide‐based assemblies are remarkably attractive for such tasks, since they provide a simple way to fuse together functional and structural protein motifs in artificial materials. Motivated by this idea, it is shown here that the introduction of a single acidic, or basic, amino acid into the side chain of a heptameric self‐assembling peptide increases proton conduction in the resulting fibers by two orders of magnitude. This self‐doping effect is much more pronounced than the effect induced by the peptide's acidic and basic termini groups. Furthermore, the self‐doping process is found to be significantly more effective for acidic side chains than for basic ones due to both much more effective self‐doping process, resulting in an order of magnitude larger concentration of charge carriers for the acidic assemblies, and higher mobility of the formed charge carriers – almost threefolds in this case. This work facilitates the realization of unique bioinspired self‐assembled proton conducting materials that may find uses in the emerging bioprotonic technology. The presented design flexibility and, in particular, the ability to introduce both proton and proton holes further extend the usefulness of these materials.     

Glycocalyx‐Like Hydrogel Coatings for Small Diameter Vascular Grafts

Novel biological vascular conduits, such as decellularized tissue engineered vascular grafts (TEVGs) are hindered by high thrombogenicity. To mimic the antithrombogenic surface of native vessels with a continuous glycosaminoglycan layer that is present on endothelial cells (ECs), a hyaluronic acid (HA) modified surface is established, to effectively shield blood platelets from collagen‐triggered activation. Using the amine groups present on 4 mm diameter decellularized TEVGs, a continuous HA hydrogel coating is built via a bifunctional thiol‐reactive cross‐linker, thereby avoiding nonspecific collagen matrix cross‐linking. The HA hydrogel layer recreates a luminal wall, “hiding” exposed collagen from the bloodstream. In vitro blood tests show that adhered platelets, fibrinogen absorption, and fibrin formation on HA‐coated decellularized TEVGs are significantly lower than on uncoated decellularized TEVGs. The HA surface also inhibits macrophage adhesion in vitro. HA‐coated decellularized syngeneic rat aortae (≈1.5 mm diameter), and TEVGs in rat and canine models, respectively, are protected from aggressive thrombus formation, and preserve normal blood flow. Re‐endothelialization is also observed. HA‐coated TEVGs may be an off‐the‐shelf small‐diameter vascular graft with dual benefits: antithrombogenic protection and promotion of endothelium.     

A Surface Chemistry Approach to Tailoring the Hydrophilicity and Lithiophilicity of Carbon Films for Hosting High‐Performance Lithium Metal Anodes

Porous carbon scaffolds can host lithium (Li) metal anodes to potentially enable stable Li metal batteries. However, the poor Li metal wettability on the carbon surface has inhibited the uniform distribution of metallic Li on most carbon scaffolds. Herein, this work reports a lithiophilic top layer through mild surface ozonolysis and ammoniation methods can universally facilitate the infiltration of liquid Li metal into most carbon matrices. Based on this finding, thin, a lightweight Li@carbon film (CF) composite anode with a high practical capacity of 3222 mAh g^?1 and suppressed volume expansion and dendrite formation is reported. It is observed that the deep stripping/plating pre‐cycling yields dense, trunky Li metal in the Li@CF composite, which allows for favorable long‐term cycling performance. The full cell combining the thin Li@CF composite anode and a high‐mass‐loading, cobalt‐free cathode can deliver high reversible capacity, good cycle stability, and good rate capability in the conventional carbonate electrolyte. The present study further establishes the relationship between lithiophilicity and hydrophilicity for carbon materials as well as provides insights into improving the liquid Li metal infiltration into other carbon scaffolds.     

Cell‐Tethered Ligands Modulate Bone Remodeling by Osteoblasts and Osteoclasts

The goals of the present study are to establish an in vitro co‐culture model of osteoblast and osteoclast function and to quantify the resulting bone remodeling. The bone is tissue engineered using well‐defined silk protein biomaterials in 2D and 3D formats in combination with human cells. Parathyroid hormone (PTH) and glucose‐dependent insulinotropic peptide (GIP) are selected because of their roles in bone remodeling for expression in tethered format on human mesenchymal stem cells (hMSCs). The cell‐modified biomaterial surfaces are reconstructed from scanning electron microscopy images into 3D models for quantitative measurement of surface characteristics. Increased calcium deposition and surface roughness are found in 3D surface models of silk protein films remodeled by co‐cultures containing tethered PTH, and decreased surface roughness is found for the films remodeled by tethered GIP co‐cultures. Increased surface roughness is not found in monocultures of hMSCs expressing tethered PTH, suggesting that osteoclast‐osteoblast interactions in the presence of PTH signaling are responsible for the increased mineralization. These data point towards the design of in vitro bone models in which osteoblast‐osteoclast interactions are mimicked for a better understanding of bone remodeling.     

Dependence of Photocurrent Enhancements in Quantum Dot (QD)‐Sensitized MoS2 Devices on MoS2 Film Properties

This report demonstrates highly efficient nonradiative energy transfer (NRET) from alloyed CdSeS/ZnS semiconductor nanocrystal quantum dots (QDs) to MoS₂ films of varying layer thicknesses, including pristine monolayers, mixed monolayer/bilayer, polycrystalline bilayers, and bulk‐like thicknesses, with NRET efficiencies of over 90%. Large‐area MoS₂ films are grown on Si/SiO₂ substrates by chemical vapor deposition. Despite the ultrahigh NRET efficiencies there is no distinct increase in the MoS₂ photoluminescence intensity. However, by studying the optoelectronic properties of the MoS₂ devices before and after adding the QD sensitizing layer photocurrent enhancements as large as ≈14‐fold for pristine monolayer devices are observed, with enhancements on the order of ≈2‐fold for MoS₂ devices of mixed monolayer and bilayer thicknesses. For the polycrystalline bilayer and bulk‐like MoS₂ devices there is almost no increase in the photocurrent after adding the QDs. Industrially scalable techniques are specifically utilized to fabricate the samples studied in this report, demonstrating the viability of this hybrid structure for commercial photodetector or light harvesting applications.     

New approach for forming bulk-heterojunction solar cells comprising a π-conjugated polymer and C60

A new approach for high-efficiency polymer solar cells utilizing a BHJ active layer consisting of poly(3-hexylthiophene) (P3HT) as a donor and buckminsterfullerene, C₆₀ as an acceptor was demonstrated. P3HT/C₆₀ BHJ films were made possible by in situ formation of C₆₀ from solubilized addends, C₆₀–CpCO₂R (R = Hex, Oct, and EHex) by retro Diels–Alder reaction at, or above, 100 °C. These cells exhibit enhanced performances compared to as-prepared P3HT/C₆₀ BHJ films, showing better morphology.     

Narrowband auscultatory blood pressure measurement

Auscultatory blood pressure measurement uses the presence and absence of acoustic pulses generated by an artery (i.e., Korotkoff sound), detected with a stethoscope or a sensitive microphone, to noninvasively estimate systolic and diastolic pressures. Unfortunately, in high noise situations, such as ambulatory environments or when the patient moves moderately, the current auscultatory blood pressure method is unreliable, if at all possible. Empirical evidence suggests that the pulse beneath an artery occlusion travels relatively slow compared with the speed of sound. By placing two microphones along the bicep muscle near the brachial artery under the occlusion cuff, a similar blood pressure pulse appears in the two microphones with a relative time delay. The acoustic noise, on the other hand, appears in both microphones simultaneously. The contribution of this paper is to utilize this phenomenon by filtering the microphone waveforms to create spatially narrowband information signals. With a narrowband signal, the microphone signal phasing information is adequate for distinguishing between acoustic noise and the blood pressure pulse. By choosing the microphone spacing correctly, subtraction of the two signals will enhance the information signal and cancel the noise signal. The general spacing problem is also presented.