Nanoscale Graded Nitrogen-Doping of TiO via Pulsed Laser Deposition for Enhancing Charge Transfer in Perovskite Solar Cells.

An electron transport layer (ETL) for highly efficient perovskite solar cells (PSCs) should exhibit superior electrical transport properties and have its band levels aligned with interfacing layers to ensure efficient extraction of photo-generated carriers. Nitrogen-doped TiO (TiO:N) is considered a promising ETL because it offers higher electrical conductivity compared to conventional ETLs made from spray-pyrolyzed TiO. However, the application of highly doped TiO:N in PSCs is often limited by the misalignment of energy band levels with adjacent layers and reduced optical transparency.

Effect of Repetitive Corticosteroid Injection on Tennis Elbow Surgery.

Background: Lateral epicondylitis is a chronic tendinopathy of humeral origin of the common extensor tendon. Most patients show improvement after nonoperative treatment. However, 4% to 11% of patients require surgical treatment.

Remnant Preservation of the Primary Vertical Graft in Revision Anterior Cruciate Ligament Reconstruction.

Background: The remnant preservation of a primary vertical graft in revision anterior cruciate ligament reconstruction (ACLR) can benefit anteroposterior stability. However, studies that address this concept are rare.

Purpose: To evaluate clinical outcomes of remnant preservation of primary vertical graft in revision ACLR.

Ultrafast Na Transport into Crystalline Sn via Dislocation-Pipe Diffusion.

The charging process of secondary batteries is always associated with a large volume expansion of the alloying anodes, which in many cases, develops high compressive residual stresses near the propagating interface. This phenomenon causes a significant reduction in the rate performance of the anodes and is detrimental to the development of fast-charging batteries. However, for the Na-Sn battery system, the residual stresses that develop near the interface are not stored, but are relieved by the generation of high-density dislocations in crystalline Sn.

Self-Assembly of Pulverized Nanoparticles: An Approach to Realize Large-Capacity, Long-Lasting, and Ultra-Fast-Chargeable Na-Ion Batteries.

The fabrication of battery anodes simultaneously exhibiting large capacity, fast charging capability, and high cyclic stability is challenging because these properties are mutually contrasting in nature. Here, we report a rational strategy to design anodes outperforming the current anodes by simultaneous provision of the above characteristics without utilizing nanomaterials and surface modifications. This is achieved by promoting spontaneous structural evolution of coarse Sn particles to 3D-networked nanostructures during battery cycling in an appropriate electrolyte.

Direct-Contact Microelectrical Measurement of the Electrical Resistivity of a Solid Electrolyte Interface.

Because of its effectiveness in blocking electrons, the solid electrolyte interface (SEI) suppresses decomposition reactions of the electrolyte and contributes to the stability and reversibility of batteries. Despite the critical role of SEI in determining the properties of batteries, the electrical properties of SEI layers have never been measured directly. In this paper, we present the first experimental results of the electrical resistivity of a LiF-rich SEI layer measured using a direct-contact microelectrical device mounted in an electron microscope.

Peculiar elastic behavior of mechanical metamaterials with various minimal surfaces.

Molecular dynamics simulations were performed on nanostructured metamaterials (NMs) with gyroid, diamond, and primitive structures to evaluate their mechanical behavior, especially elastic properties. Unlike the constant nature of Young's (E) and shear (μ) moduli of bulk materials, the values of both E and μ of NMs change with relative density and cell size but at different rates depending on the morphologies of the structure. This is particularly the case for μ; for a given relative density and cell size of NMs, the μ values differ greatly, depending on the types of structure, causing the NMs to display differing μ/E values and thus resistance to shear deformation.

Ultrafast Sodiation of Single-Crystalline Sn Anodes.

Sodiation was performed on crystalline Sn cylinders using an in situ electron microscope to evaluate the rate performance of the Sn anode by directly measuring the sodiation rate. We observed that the sodiation rate of the Sn anode is more than 2 orders of magnitude higher than the lithiation rate of the Si anode under the same conditions. This unprecedented rate displayed by the Na-Sn system is attributed to the bond characteristics and crystalline-to-amorphous transformation of the Sn crystal at the thin interface of the Na-Sn diffusion couple.

Interfacial Reactions in the Li/Si diffusion couples: Origin of Anisotropic Lithiation of Crystalline Si in Li-Si batteries.

As opposed to the common understanding that diffusion into a cubic-structured single crystal is independent of its crystalline orientation, the diffusion of Li to crystalline Si (c-Si) is anisotropic, which acts as the major cause for the fracture of Si anodes in Li-ion batteries. Here, by conducting comprehensive/multi-scale simulation studies based on molecular dynamics and density functional theory, we elucidate how and why Li diffusion in c-Si is anisotropic. We found that Li ions diffuse to c-Si by following a particular atomic-scale space corresponding to the lowest value of the valence orbital in c-Si, causing Li ions to take a tortuous diffusion pathway.

Unusually high ratio of shear modulus to Young's modulus in a nano-structured gyroid metamaterial.

Unlike the constant nature of elastic coefficients of isotropic bulk materials, the Young's (E) and shear (μ) moduli of nano-structured (NS) gyroid metamaterials change with relative density (ρ), but at different rates depending on the cell size of the structure. These elastic behaviors displayed by E and μ cause crossover/inversion of these two moduli, such that μ of the NS gyroid metamaterials is greater than E for the structures with ρ < 0.23.

[Hong Seok-hoo's translation of "New Edition of Physiology Textbook"(1906) and its meanings].

Hong Seok-hoo, who took charge of Jejungwon, was successful in translating Jiro Tsuboi's book titled "New Edition of Physiology Textbook (1897)" in Japanese and publishing it with a title of "New Edition of Physiology Textbook" in 1906. Jiro Tsuboi, the original author of that book, was a doctor having majored in Hygienics in Germany and was also known to have done pioneering work in Hygienics and Occupational and Environmental Medicine in Japan. At that time, he wrote that book for the purpose of teaching his students at Ordinary Middle School and Normal School.

[The translation and its meanings of Materia Medica Part. I in the Jejungwon].

For more systematic medical education, Dr. O. R.