LiNi₁/₃Co₁/₃Mn₁/₃O₂-graphene composite as a promising cathode for lithium-ion batteries

The use of graphene as a conductive additive to enhance the discharge capacity and rate capability of LiNi(1/3)Co(1/3)Mn(1/3)O(2) electrode material has been demonstrated. LiNi(1/3)Co(1/3)Mn(1/3)O(2) and its composite with graphene (90:10 wt %) were prepared by microemulsion and ball-milling techniques, respectively. The structural and morphological features of the prepared materials were investigated with powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. Characterization techniques depict single-phase LiNi(1/3)Co(1/3)Mn(1/3)O(2) with particle sizes in the range of 220-280 nm. Electrochemical studies on LiNi(1/3)Co(1/3)Mn(1/3)O(2) and LiNi(1/3)Co(1/3)Mn(1/3)O(2)-graphene were conducted using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy methods by constructing a lithium half-cell. Cyclic voltammograms show the well-defined redox peaks corresponding to Ni(2+)/Ni(4+). Charge-discharge tests were performed at different C rates: 0.05, 1, and 5 between 2.5 and 4.4 V. The results indicate the better electrochemical performance of the LiNi(1/3)Co(1/3)Mn(1/3)O(2)-graphene composite in terms of high discharge capacity (188 mAh/g), good rate capability, and good cycling performance compared to LiNi(1/3)Mn(1/3)Co(1/3)O(2). The improved electrochemical performance of the LiNi(1/3)Co(1/3)Mn(1/3)O(2)-graphene composite is attributed to a decrease in the charge-transfer resistance.     

Involvement of sensory neurons in bone defect repair in rats

We investigated bone repair in sensory-denervated rats, compared with controls, to elucidate the involvement of sensory neurons. Nine-week-old male Wistar rats received subcutaneous injections of capsaicin to denervate sensory neurons. Rats treated with the same amount of vehicle served as controls. A standardized bone defect was created on the parietal bone. We measured the amount of repaired bone with quantitative radiographic analysis and the mRNA expressions of osteocalcin and cathepsin K with real-time polymerase chain reaction (PCR). Quantitative radiographic analysis showed that the standard deviations and coefficients of variation for the amount of repaired bone were much higher in the capsaicin-treated group than in the control group at any time point, which means that larger individual differences in the amount of repaired bone were found in capsaicin-treated rats than controls. Furthermore, radiographs showed radiolucency in pre-existing bone surrounding the standardized defect only in the capsaicin-treated group, and histological observation demonstrated some multinuclear cells corresponding to the radiolucent area. Real-time PCR indicated that there was no significant difference in the mRNA expression levels of osteocalcin and cathepsin K between the control group and the capsaicin-treated group. These results suggest that capsaicin-induced sensory denervation affects the bone defect repair.     

A novel approach to a fine particle coating using porous spherical silica as core particles

The applicability of porous spherical silica (PSS) was evaluated as core particles for pharmaceutical products by comparing it with commercial core particles such as mannitol (NP-108), sucrose and microcrystalline cellulose spheres. We investigated the physical properties of core particles, such as particle size distribution, flow properties, crushing strength, plastic limit, drying rate, hygroscopic property and aggregation degree. It was found that PSS was a core particle of small particle size, low friability, high water adsorption capacity, rapid drying rate and lower occurrence of particle aggregation, although wettability is a factor to be carefully considered. The aggregation and taste-masking ability using PSS and NP-108 as core particles were evaluated at a fluidized-bed coating process. The functional coating under the excess spray rate shows different aggregation trends and dissolution profiles between PSS and NP-108; thereby, exhibiting the formation of uniform coating under the excess spray rate in the case of PSS. This expands the range of the acceptable spray feed rates to coat fine particles, and indicates the possibility of decreasing the coating time. The results obtained in this study suggested that the core particle, which has a property like that of PSS, was useful in overcoming such disadvantages as large particle size, which feels gritty in oral cavity; particle aggregation; and the long coating time of the particle coating process. These results will enable the practical fine particle coating method by increasing the range of optimum coating conditions and decreasing the coating time in fluidized bed technology.     

A real-time inspection system using a terahertz technique to detect microleak defects in the seal of flexible plastic packages

A method to detect production faults in flexible plastic packages with the use of terahertz radiation is presented. Relying on the large difference between the absorption coefficients of plastic and water (for water-filled channel defects) and on the refraction index difference between plastic and air (for air-filled channel defects), our technique consists of focusing and scanning a terahertz beam on the sealed area of the package, followed by detection of the transmitted signal. Compared with previous methods, such as visual and ultrasound inspection, our technique can be applied to optically opaque packages and does not require immersion in a matching liquid. We tested our system on defects that we fabricated as water-filled and air-filled channels imbedded in polyethylene films, with diameters in the range of 10 to 100 microm. The detection limit (the minimum size of a detectable defect) depends on the conveying speed; this relationship was determined and analyzed. The results show that our system has the potential for application in an actual production line for real-time inspection.     

Integrating Oxygen and 3D Cell Culture System: A Simple Tool to Elucidate the Cell Fate Decision of hiPSCs

Oxygen, as an external environmental factor, plays a role in the early differentiation of human stem cells, such as induced pluripotent stem cells (hiPSCs). However, the effect of oxygen concentration on the early-stage differentiation of hiPSC is not fully understood, especially in 3D aggregate cultures. In this study, we cultivated the 3D aggregation of hiPSCs on oxygen-permeable microwells under different oxygen concentrations ranging from 2.5 to 20% and found that the aggregates became larger, corresponding to the increase in oxygen level. In a low oxygen environment, the glycolytic pathway was more profound, and the differentiation markers of the three germ layers were upregulated, suggesting that the oxygen concentration can function as a regulator of differentiation during the early stage of development. In conclusion, culturing stem cells on oxygen-permeable microwells may serve as a platform to investigate the effect of oxygen concentration on diverse cell fate decisions during development.     

Design and calibration of curved and see-through integral imaging 3D display

Virtual Reality - Heads-up displays that are ‘see-through’ and ‘curved’ and capable of displaying 3D contents are considered crucial for augmented reality-based navigation...     

Bio-Inspired Adhesive with Reset-On Demand,Reuse-Many (RORM) Modes

Development of tough, reusable adhesives is important, but remains a major challenge, especially in water. A tough reusable adhesive that resets entirely to its virgin condition when needed is reported using caffeic acid. Here, caffeic acid is employed as adhesive moiety to achieve such the functions due to its dual characteristics: an adhesive moiety from mussel-inspired catechol and a photo-reversible crosslink from cinnamic acid. Adhesion involves a two-step process. First, the caffeic acid-functionalized polymer is applied to the adherend, followed by UV irradiation (peak wavelength of light-emitting diode, λ_P: 365 nm) to form a durable pre-applied adhesive (PAA) layer through crosslinking among the caffeic acid moieties. Second, thermal activation of the PAA layer ensures repeated adhesion to a variety of adherends ( R euse- M any mode). The cyclic dimer of the caffeic acid moiety is de-crosslinked by UV irradiation at λ_P: 254 nm. This allows the complete removal of the adhesive residues from the adherends when the adhesive is no longer needed ( R eset- O n demand mode). Furthermore, using magnetic nanoparticles, the caffeic acid-functionalized polymer can be activated remotely under water by magnetic induction heating. This study paves the way for the rational design of bio-inspired adhesives that outperform nature using plant-derived raw materials.