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Metal-free N- and O-arylation reactions of pyridin-2-ones as ambident nucleophiles have been achieved with diaryliodonium salts on the basis of base-dependent chemoselectivity. In the presence of N,N-diethylaniline in fluorobenzene, pyridin-2-ones were very selectively converted to N-arylated products in high yields. On the other hand, the O-arylation reactions smoothly proceeded with the use of quinoline in chlorobenzene, leading to high yields and selectivities. In these methods, a variety of pyridin-2-ones in addition to pyridin-4-one and a set of diaryliodonium salts were accepted as suitable reaction partners., Chemical Science, 11(31), pp.8295-8300; 2020

The present study investigated the role of SiOx in a rice-husk-derived C/SiOx anode on the rate and cycling performance of a Li-ion battery. C/SiOx active materials with different SiOx contents (45, 24, and 5 mass%) were prepared from rice husk by heat treatment and immersion in NaOH solution. The C and SiOx specific capacities were 375 and 475 mAh g−1, respectively. A stable anodic operation was achieved by pre-lithiating the C/SiOx anode. Full-cells consisting of this anode and a Li(Ni0.5Co0.2Mn0.3)O2 cathode displayed high initial Coulombic efficiency (~ 85%) and high discharge specific capacity, indicating the maximum performance of the cathode (~ 150 mAh g−1). At increased current density, the higher the SiOx content, the higher the specific capacity retention, suggesting that the time response of the reversible reaction of SiOx with Li ions is faster than that of the C component. The full-cell with the highest SiOx content exhibited the largest decrease in cell specific capacity during the cycle test. The structural decay caused by the volume expansion of SiOx during Li-ion uptake and release degraded the cycling performance. Based on its high production yield and electrochemical benefits, degree of cycling performance degradation, and disadvantages of its removal, SiOx is preferably retained for Li-ion battery anode applications.

Rice husk (RH) is a globally abundant and sustainable bioresource composed of lignocellulose and inorganic components, the majority of which consist of silicon oxides (approximately 20% w/w in dried RH). In this work, a RH-derived C/SiOx composite (RHC) was prepared by carbonization at 1000 °C for use in Li-ion battery anodes. To find a suitable binder for RHC, the RHC-based electrodes were fabricated using two different contemporary aqueous binders: polyacrylic acid (PAA) and a combination of carboxymethyl cellulose and styrene butadiene rubber (CMC/SBR). The rate and cycling performances of the RHC electrodes with respect to the insertion/extraction of Li ions were evaluated in a half-cell configuration. The cell was shorted for 24 h to completely lithiate the RHC. Impedance analysis was conducted to identify the source of the increase in the resistance of the RHC electrodes. The RHC electrode fabricated using PAA exhibited higher specific capacity for Li-ion extraction during the cycling test. The PAA binder strengthened the electrode and alleviated the increase in electrode resistance caused by the formation of the interphase film. The high affinity of PAA for SiOx in RHC was responsible for the stabilization of the anodic performance of Li-ion batteries.

We studied the pollination biology of a native orchid Spiranthes australis in Kobe, Hyogo, Japan, and observed that S. australis flowers are frequently visited by the managed honeybee A. mellifera. Since the honeybees extracted pollinaria from the anthers and deposited pollinia on the stigmas of many flowers, the behavior resulted in the successful pollination of multiple flowers even in a single visitation. Given that (i) the honeybee was the most frequent and intensive pollinator during our observation period and (ii) the fruit set in the investigated population was significantly higher than the fruit set of a previously investigated S. australis population, despite lack of ability for autonomous self-pollination, A. mellifera may promote a high reproductive success in S. australis. Our observation provides some insight into the diversity of orchid-pollinator interactions, drawing attention to the potential importance of non-native bees as pollinators.

In recent years, SiC power modules have attracted a lot of attention because they offer higher frequency and density as compared to the conventional Si power module. However high speed switching inevitably lead to the generation of surge voltage which may damage the power module. The design of layout, which composed of copper patterns, power semiconductors and terminals, is one of the factors that is necessary to overcome the problem. In this paper, the layout design of the half-bridge power module is optimized to reduce its internal inductance. The inductance was evaluated by electromagnetic field simulation.

The influence of the capacity ratio of the negative to positive electrode (N/P ratio) on the rate and cycling performances of LiFePO4/graphite lithium-ion batteries was investigated using 2032 coin-type full and three-electrode cells. LiFePO4/graphite coin cells were assembled with N/P ratios of 0.87, 1.03 and 1.20, which were adjusted by varying the mass of the graphite negative electrode. Three-electrode cells were also assembled with similar N/P ratios to understand the potential variations of the positive and negative electrodes. The cycling performances of the coin cells were evaluated by repeating the charge-discharge cycle 5000 times (1 C-rate for the 1st–1000th cycle and 2 C-rate for the 1001st–5000th cycle) at cell voltages of 2.5–4.2 V, during which their rate performances were intermittently evaluated (0.1–10 C-rate). Prior to the charge-discharge cycling test, the highest cell specific capacity was obtained from the lowest N/P ratio of 0.87. The coin cell with the highest N/P ratio of 1.20 exhibited the highest capacity retention of 86.5% at 1 or 2 C-rate in the 5000 cycle test. The results obtained using the three-electrode cells showed that the higher N/P ratio elevated the working potential ranges of the positive and negative electrodes. The lower N/P ratio led to deeper Li-ion intercalation for the negative electrode, lowering the potential of both the positive and negative electrodes. The lower N/P ratio was beneficial for achieving full performances from the initial service, but caused larger capacity fading due to the aging by cycling. The higher N/P ratio rather restricted the performances at the initial service, which was useful to prevent the cycling-derived capacity fading. The lowering of rate performance owing to the charge-discharge cycling, particularly at the high current densities of 5 and 10 C-rates, was enhanced by the decrease in the N/P ratio.

We report synthesis of nanosized oxide materials using a novel water assisted solid state reaction (WASSR) method. This novel soft chemical synthesis method is very simple and can synthesize nanoparticle materials just by storing or mixing raw materials added a small amount (typically 10wt%) of water in a reactor at low temperature below 373 K. Combinations of raw materials have a significant influence on the reaction rate.

Extensive attention has been focused toward studies on inexpensive and rare-earth-free garnet-structure vanadate phosphors, which do not have a low optical absorption due to the luminescence color being easily controlled by its high composition flexibility. However, bluish emission phosphors with a high quantum efficiency have not been found until now. In this study, we successfully discovered bluish-white emitting, garnet structure-based LiCa3MV3O12 (M = Zn and Mg) phosphors with a high quantum efficiency, and the detailed crystal structure was refined by the Rietveld analysis technique. These phosphors exhibit a broad-band emission spectra peak at 481 nm under near UV-light excitation at 341 nm, indicating no clear difference in the emission and excitation spectra. A very compact tetrahedral [VO4] unit is observed in the LiCa3MV3O12 (M = Zn and Mg) phosphors, which is not seen in other conventional garnet compounds, and generates a bluish-white emission. In addition, these phosphors exhibit high quantum...

Ceramic materials have been widely used in various applications and are significantly important in our daily life. The various methods for synthesizing ceramics powder materials have been already r...

Magnesium metavanadate dihydrate (MgV 2 O 6 ·2H 2 O) was synthesized as a nanophosphor by a water-assisted solid-state reaction (WASSR) method, and its crystal structure and luminescence properties were investigated in detail. MgV 2 O 6 ·2H 2 O has an orthorhombic structure with space group Pnma . In the crystal structure, the MgO 6 octahedra and VO 4 tetrahedra formed a layered structure in the direction of the b axis, and the VO 4 tetrahedra formed a chain structure along the a axis. The nanophosphor showed broad and strong optical absorption in the near-ultraviolet region and exhibited a broad yellow emission peak at 563 nm.

In the emergency care field, early treatment of acute heart or respiratory failure has been a global concern. In severe cases, patients are frequently required to be on an extracorporeal membrane oxygenator (ECMO) life support. To make the ECMO system more compact and portable, we proposed a sequential flow-type centrifugal pump named the sequential flow pump (SFP). In this study, principle and basic properties of this novel blood pump were examined by computational fluid dynamic (CFD) analysis and an experimental model. In the SFP, fluid is given centrifugal force sequentially twice with a single closed impeller. This sequential pressurization mechanism enables high-pressure output without high impeller speed. To realize easy integration of a blood pump with an artificial lung, the inlet and outlet ports are located at lateral side and center of the pump, respectively, which is the reverse configuration of conventional centrifugal pumps. The computational model was composed for CFD analysis and the experimental model was developed for the experiment of the actual pump. For both models, dimension of the impeller and volute was designed to be equal. In the CFD analysis, the SFP could generate higher performance than the single pressurization model with the same rotational speed of the impeller. Basic property of the experimental model was very similar to that of the computational model. The results showed the possibility that the SFP would be more suitable for the compact ECMO system than conventional centrifugal pumps.

A single-phase red-emitting NaEu(MoO4)2 phosphor with nanosized particles was synthesized using a water-assisted solid state reaction (WASSR) method, a new low-temperature synthesis method developed by our group. NaEu(MoO4)2 exhibits a monoclinic structure with a space group C2/c (no. 15), which is composed of a Na/EuO8 dodecahedron with the site occupancy of Na/Eu = 1 : 1 and an MoO4 tetrahedron. To enhance the emission intensity of the NaEu(MoO4)2 phosphor, Gd3+ was doped into the Eu3+ sites and NaEu1−xGdx(MoO4)2 (0 0.30. This indicates that the optimum composition of the phosphor for achieving a high emission intensity that is ∼3.8 times higher than that of the NaEu(MoO4)2 (x = 0) phosphor is NaEu0.70Gd0.30(MoO4)2. These phosphors exhibit a granular particle morphology with the particle size of the phosphor being ∼200 nm.

Lithium-ion batteries (LIBs) using a LiFePO4 cathode and graphite anode were assembled in coin cell form and subjected to 1000 charge-discharge cycles at 1, 2, and 5 C at 25 &deg, C. The performance degradation of the LIB cells under different C-rates was analyzed by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy. The most severe degradation occurred at 2 C while degradation was mitigated at the highest C-rate of 5 C. EIS data of the equivalent circuit model provided information on the changes in the internal resistance. The charge-transfer resistance within all the cells increased after the cycle test, with the cell cycled at 2 C presenting the greatest increment in the charge-transfer resistance. Agglomerates were observed on the graphite anodes of the cells cycled at 2 and 5 C, these were more abundantly produced in the former cell. The lower degradation of the cell cycled at 5 C was attributed to the lowered capacity utilization of the anode. The larger cell voltage drop caused by the increased C-rate reduced the electrode potential variation allocated to the net electrochemical reactions, contributing to the charge-discharge specific capacity of the cells.

This article describes procedures to synthesize 2'-OMe-RNA modified with cross-linkable 2-amino-7-deaza-7-propynyl-6-vinylpurine (ADpVP) and preparation of the RNA-crosslinking experiment in vitro. All synthesis steps yield the desired compound in moderate or high yield without expensive chemical reagents or specific devices. The crosslink-active form of modified RNA can also be purified by commonly used reversed-phase HPLC, can be stored at -80°C after lyophilization for a few days, and is ready to use for crosslinking experiments. This crosslink-active RNA can efficiently form covalent bonds with complementary RNA in a sequence-specific manner. © 2019 by John Wiley & Sons, Inc.

A variety of functionalized silacyclopentanes were synthesized by highly enantioselective β-eliminations of silacyclopentene oxides followed by stereospecific transformations. The reaction mechanism of the β-elimination was elucidated by DFT calculations. An in vitro biological assay with an oxy-functionalized silacyclopentane showed substantial binding to a serotonin receptor protein.

Estimation of pressure and flow has been an important subject for developing implantable artificial hearts. To realize real-time viscosity-adjusted estimation of pressure head and pump flow for a total artificial heart, we propose the table estimation method with quasi-pulsatile modulation of rotary blood pump in which systolic high flow and diastolic low flow phased are generated. The table estimation method utilizes three kinds of tables: viscosity, pressure and flow tables. Viscosity is estimated from the characteristic that differential value in motor speed between systolic and diastolic phases varies depending on viscosity. Potential of this estimation method was investigated using mock circulation system. Glycerin solution diluted with salty water was used to adjust viscosity of fluid. In verification of this method using continuous flow data, fairly good estimation could be possible when differential pulse width modulation (PWM) value of the motor between systolic and diastolic phases was high. In estimation under quasi-pulsatile condition, inertia correction was provided and fairly good estimation was possible when the differential PWM value was high, which was not different from the verification results using continuous flow data. In the experiment of real-time estimation applying moving average method to the estimated viscosity, fair estimation could be possible when the differential PWM value was high, showing that real-time viscosity-adjusted estimation of pressure head and pump flow would be possible with this novel estimation method when the differential PWM value would be set high.

Histopathological analysis can provide important information in long-term experiments with total artificial heart (TAH). Recently, a new type of blood pump, the helical flow total artificial heart (HF-TAH) was developed. This study aimed to investigate the changes in selected vital organs in animal experiments with implanted HF-TAH. Samples from lung, liver, and kidneys from two female goats (No. 1301 and No. 1304) with implanted HF-TAH were analyzed. Tissue samples were fixed in 10% formaldehyde and 4 µm thick transverse sections were stained with hematoxylin-eosin (HE). Additional staining was done for detection of connective tissue (Masson-Goldner stain) and for detection of iron (hemosiderin) deposits (Perls stain). Sections were scanned at 100× and 500× magnification with a light microscope. Experiment no. 1301 survived 100 days (cause of termination was heavy damage of the right pump); experimental goat no.1304 survived 68 days and was sacrificed due to severe right hydrodynamic bearing malfunction. Histopathological analysis of liver samples proved signs of chronic venostasis with limited focal necrotic zones. Dilated tubules, proteinaceous material in tubular lumen, and hemosiderin deposits were detected in kidney samples. Contamination of the organs by embolized micro-particles was suspected at the autopsy after discovery of visible damage (scratches) of the pump impeller surface (made from titanium alloy) in both experiments. Sporadic deposits of foreign micro-particles (presumably titanium) were observed in most of the analyzed parenchymal organs. However, the described deposits were not in direct connection with inflammatory reactions in the analyzed tissues. Histopathological analysis showed the presence of minimal contamination of the lung, kidney, and liver tissue samples by foreign material (titanium very likely). The analysis showed only limited pathological changes, especially in liver and kidneys, which might be attributed to the influence of artificial perfusion often observed in chronic TAH experiments.

The reorientational relaxation times of some small aromatic solutes are determined with nuclear magnetic resonance spectroscopy and time-resolved fluorescence anisotropy measurements in various solvents that exhibit viscoelasticity in the megahertz region. All the reorientational relaxation times in viscoelastic liquids are shorter than those predicted by the hydrodynamic Stokes-Einstein-Debye (SED) relation using the steady-state shear viscosity. The deviation from the SED relation becomes larger in solvents whose shear relaxation is slower. When the reorientational relaxation times in a solvent are compared, the deviation from the SED relation tends to decrease when the reorientational relaxation time increases. From a comparison with the shear relaxation spectra, it is demonstrated that the deviation from the SED relation can be ascribed to the effective reduction of the viscous friction on fast reorientation, reflecting the decrease in shear viscosity with increasing frequency.