Cathode active materials using rare metals recovered from waste lithium-ion batteries: A review.

Large-scale lithium-ion batteries (LIBs) are overtaking as power sources for electric vehicles and grid-scale energy-storage systems for renewable sources. Accordingly, large amounts of LIBs are expected to be discarded in the near future. Recycling technologies for waste LIBs, particularly for valuable rare metals (Li, Co, and Ni) used in cathode active materials, need to be developed to construct continuous LIB supply chains. Various recovery methodologies, such as pyrometallurgy, hydrometallurgy, and direct recycling, as well as their advantages, disadvantages, and technical features, are briefly introduced. We review the electrochemical performances of these cathode active materials based on recycled rare metals from LIB waste. Moreover, the physicochemical properties and electrochemical performance of the cathode active materials with impurities incorporated during recycling, which have high academic significance, are outlined. In hydrometallurgy-based LIB recycling, the complete removal of impurities in cathode active materials is not realistic for the mass and sustainable production of LIBs; thus, optimal control of the impurity levels is of significance. Meanwhile, the studies on the direct recycling of LIB showed the necessity of almost complete impurity removal and restoration of physicochemical properties in cathode active materials. This review provides a survey of the technological outlook of reusing cathode active materials from waste LIBs.

Role of SiOx in rice-husk-derived anodes for Li-ion batteries.

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.

Suitable binder for Li-ion battery anode produced from rice husk.

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.

N- and O-arylation of pyridin-2-ones with diaryliodonium salts: base-dependent orthogonal selectivity under metal-free conditions.

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.

Synthesis of RNA Crosslinking Oligonucleotides Modified with 2-Amino-7-Deaza-7-Propynyl-6-Vinylpurine.

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.

Mitotic phosphorylation of HP1α regulates its cell cycle-dependent chromatin binding.

Heterochromatin protein 1 (HP1) is an evolutionarily conserved chromosomal protein that plays a crucial role in heterochromatin-mediated gene silencing. We previously showed that mammalian HP1α is constitutively phosphorylated at its N-terminal serine residues by casein kinase II (CK2), and that this phosphorylation enhances HP1α's binding specificity for nucleosomes containing lysine 9-methylated histone H3 (H3K9me). Although the presence of additional HP1α phosphorylation during mitosis was reported more than a decade ago, its biological significance remains largely elusive. Here we found that mitosis-specific HP1α phosphorylation affected HP1α's ability to bind chromatin. Using biochemical and mutational analyses, we showed that HP1α's mitotic phosphorylation was located in its hinge region and was reversibly regulated by Aurora B kinase and serine/threonine phosphatases. In addition, chromatin fractionation and electrophoretic mobility shift assays revealed that hinge region-phosphorylated HP1α was preferentially dissociated from mitotic chromatin and exhibited a reduced DNA-binding activity. Although HP1's mitotic behaviour was previously linked to H3 serine 10 phosphorylation, which blocks the binding of HP1's chromodomain to H3K9me3, our findings suggest that mitotic phosphorylation in HP1α's hinge region also contributes to changes in HP1α's association with mitotic chromatin.

Synthesis and Properties of 2'-OMe-RNAs Modified with Cross-Linkable 7-Deazaguanosine Derivatives.

Cross-linkable 7-deaza-6-vinylguanosine (ADVP) and 7-propynyl-7-deaza-6-vinylguanosine (ADpVP) derivatives were synthesized and successfully incorporated into 2'-OMe-RNA oligonucleotides by solid-phase oligonucleotide synthesis. Analysis of their cross-link properties revealed that the 7-propynyl substituent on ADpVP induces a significant enhancement of the cross-link kinetics of the proximal 6-vinyl group to the complementary uracil base in the target RNA compared to that of ADVP. In addition, the 2'-OMe-RNA oligonucleotide containing ADpVP exhibited a higher antisense effect on luciferase production in the cell lysate than that of ADVP. These results suggested that the 7-substituted 7-deaza-6-vinylguanosine derivatives can be used as potent cross-linkers to target mRNA inside of cells.

A new insight into cystatin C contained in milk basic protein to bone metabolism: Effects on osteoclasts and osteoblastic MC3T3-E1 cells in vitro.

A milk protein fraction possessing alkaline isoelectric points (milk basic protein [MBP]) improves bone metabolism in vivo, and it inhibits bone resorption by osteoclasts and promotes mouse osteoblastic MC3T3-E1 cells proliferation in vitro. Cystatin C (CysC) is a component of MBP and shows bone resorption inhibitory activity. Therefore, it is likely that MBP with higher CysC content improves bone metabolism more effectively. In this study, we prepared MBP with low and high contents of CysC and compared its effects on bone metabolism with standard MBP in vitro. Our results showed that the CysC content in MBP was positively related to not only bone resorption inhibitory activity but also MC3T3-E1 cells proliferative activity. Furthermore, purified CysC stimulated MC3T3-E1 cells proliferation. These results indicate that CysC contributes to promotion of MC3T3-E1 cells proliferation, and MBP with higher CysC content shows enhanced bone resorption inhibitory activity and MC3T3-E1 cells proliferative activity. CysC is considered an important factor in the effect on bone metabolism of MBP.

Bluish-White Luminescence in Rare-Earth-Free Vanadate Garnet Phosphors: Structural Characterization of LiCa3MV3O12 (M = Zn and Mg).

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 efficiencies of 40.1% (M = Zn) and 44.0% (M = Mg), respectively. Therefore, these vanadate garnet phosphors can provide a new blue color source for LED devices.

Appropriate control time constant in relation to characteristics of the baroreflex vascular system in 1/R control of the total artificial heart.

1/R control is a physiological control method of the total artificial heart (TAH) with which long-term survival was obtained with animal experiments. However, 1/R control occasionally diverged in the undulation pump TAH (UPTAH) animal experiment. To improve the control stability of the 1/R control, appropriate control time constant in relation to characteristics of the baroreflex vascular system was investigated with frequency analysis and numerical simulation. In the frequency analysis, data of five goats in which the UPTAH was implanted were analyzed with first Fourier transform technique to examine the vasomotion frequency. The numerical simulation was carried out repeatedly changing baroreflex parameters and control time constant using the elements-expanded Windkessel model. Results of the frequency analysis showed that the 1/R control tended to diverge when very low frequency band that was an indication of the vasomotion frequency was relative high. In numerical simulation, divergence of the 1/R control could be reproduced and the boundary curves between the divergence and convergence of the 1/R control varied depending on the control time constant. These results suggested that the 1/R control tended to be unstable when the TAH recipient had high reflex speed in the baroreflex vascular system. Therefore, the control time constant should be adjusted appropriately with the individual vasomotion frequency.

Principle and basic property of the sequential flow pump.

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.

Antithrombotic Protein Filter Composed of Hybrid Tissue-Fabric Material has a Long Lifetime.

There are recent reports of hybrid tissue-fabric materials with good performance-high biocompatibility and high mechanical strength. In this study, we demonstrate the capability of a hybrid material as a long-term filter for blood proteins. Polyester fabrics were implanted into rats to fabricate hybrid tissue-fabric material sheets. The hybrid materials comprised biological tissue grown on the fabric. The materials were extracted from the rat's body, approximately 100 days post-implantation. The tissues were decellularized to prevent immunological rejection. An antithrombogenicity test was performed by dropping blood onto the hybrid material surface. The hybrid material showed lesser blood coagulation than polysulfone and cellulose. Blood plasma was filtered using the hybrid material to evaluate the protein removal percentage and the lifetime of the hybrid material in vitro. The hybrid material showed a comparable performance to conventional filters for protein removal. Moreover, the hybrid material could work as a protein filter for 1 month, which is six times the lifetime of polysulfone.

Enantioselective Synthesis of Silacyclopentanes.

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

Ultraflexible organic amplifier with biocompatible gel electrodes.

In vivo electronic monitoring systems are promising technology to obtain biosignals with high spatiotemporal resolution and sensitivity. Here we demonstrate the fabrication of a biocompatible highly conductive gel composite comprising multi-walled carbon nanotube-dispersed sheet with an aqueous hydrogel. This gel composite exhibits admittance of 100 mS cm(-2) and maintains high admittance even in a low-frequency range. On implantation into a living hypodermal tissue for 4 weeks, it showed a small foreign-body reaction compared with widely used metal electrodes. Capitalizing on the multi-functional gel composite, we fabricated an ultrathin and mechanically flexible organic active matrix amplifier on a 1.2-µm-thick polyethylene-naphthalate film to amplify (amplification factor: ∼200) weak biosignals. The composite was integrated to the amplifier to realize a direct lead epicardial electrocardiography that is easily spread over an uneven heart tissue.

Viscosity-adjusted estimation of pressure head and pump flow with quasi-pulsatile modulation of rotary blood pump for a total artificial heart.

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.

HP1-Assisted Aurora B Kinase Activity Prevents Chromosome Segregation Errors.

Incorrect attachment of kinetochore microtubules is the leading cause of chromosome missegregation in cancers. The highly conserved chromosomal passenger complex (CPC), containing mitotic kinase Aurora B as a catalytic subunit, ensures faithful chromosome segregation through destabilizing incorrect microtubule attachments and promoting biorientation of chromosomes on the mitotic spindle. It is unknown whether CPC dysfunction affects chromosome segregation fidelity in cancers and, if so, how. Here, we show that heterochromatin protein 1 (HP1) is an essential CPC component required for full Aurora B activity. HP1 binding to the CPC becomes particularly important when Aurora B phosphorylates kinetochore targets to eliminate erroneous microtubule attachments. Remarkably, a reduced proportion of HP1 bound to CPC is widespread in cancers, which causes an impairment in Aurora B activity. These results indicate that HP1 is an essential modulator for CPC function and identify a molecular basis for chromosome segregation errors in cancer cells.

Histopathology Image Analysis in Two Long-Term Animal Experiments with Helical Flow Total Artificial Heart.

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.

Reorientational Relaxation of Small Solutes in Viscoelastic Liquids.

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.