Lattice pinning in MoO3 via coherent interface with stabilized Li+ intercalation.

Large lattice expansion/contraction with Li+ intercalation/deintercalation of electrode active materials results in severe structural degradation to electrodes and can negatively impact the cycle life of solid-state lithium-based batteries. In case of the layered orthorhombic MoO3 (α-MoO3), its large lattice variation along the b axis during Li+ insertion/extraction induces irreversible phase transition and structural degradation, leading to undesirable cycle life. Herein, we propose a lattice pinning strategy to construct a coherent interface between α-MoO3 and η-Mo4O11 with epitaxial intergrowth structure. Owing to the minimal lattice change of η-Mo4O11 during Li+ insertion/extraction, η-Mo4O11 domains serve as pin centers that can effectively suppress the lattice expansion of α-MoO3, evidenced by the noticeably decreased lattice expansion from about 16% to 2% along the b direction. The designed α-MoO3/η-Mo4O11 intergrown heterostructure enables robust structural stability during cycling (about 81% capacity retention after 3000 cycles at a specific current of 2 A g-1 and 298 ± 2 K) by harnessing the merits of epitaxial stabilization and the pinning effect. Finally, benefiting from the stable positive electrode-solid electrolyte interface, a highly durable and flexible all-solid-state thin-film lithium microbattery is further demonstrated. This work advances the fundamental understanding of the unstable structure evolution for α-MoO3, and may offer a rational strategy to develop highly stable electrode materials for advanced batteries.

Clinical diagnosis of genetic disorders at both single-nucleotide and chromosomal levels based on BGISEQ-500 platform.

Most variations in the human genome refer to single-nucleotide variation (SNV), small fragment insertions and deletions, and genomic copy number variation (CNV). Many human diseases including genetic disorders are associated with variations in the genome. These disorders are often difficult to be diagnosed because of their complex clinical conditions, therefore, an effective detection method is needed to facilitate clinical diagnosis and prevent birth defects. With the development of high-throughput sequencing technology, the method of targeted sequence capture chip has been extensively used owing to its high throughput, high accuracy, fast speed, and low cost. In this study, we designed a chip that potentially captured the coding region of 3043 genes associated with 4013 monogenic diseases, with an addition of 148 chromosomal abnormalities that can be identified by targeting specific regions. To assess the efficiency, a strategy of combining the BGISEQ500 sequencing platform with the designed chip was utilized to screen variants in 63 patients. Eventually, 67 disease-associated variants were found, 31 of which were novel. The results of the evaluation test also show that this combined strategy complies with the requirements of clinical testing and has proper clinical application value.

A novel gene ZNF862 causes hereditary gingival fibromatosis.

Hereditary gingival fibromatosis (HGF) is the most common genetic form of gingival fibromatosis which is featured as a localized or generalized overgrowth of gingivae. Currently two genes (SOS1 and REST), as well as four loci (2p22.1, 2p23.3-p22.3, 5q13-q22, and 11p15), have been identified as associated with HGF in a dominant inheritance pattern. Here, we report 13 individuals with autosomal-dominant HGF from a four-generation Chinese family. Whole-exome sequencing followed by further genetic co-segregation analysis was performed for the family members across three generations. A novel heterozygous missense mutation (c.2812G > A) in zinc finger protein 862 gene (ZNF862) was identified, and it is absent among the population as per the Genome Aggregation Database. The functional study supports a biological role of ZNF862 for increasing the profibrotic factors particularly COL1A1 synthesis and hence resulting in HGF. Here, for the first time we identify the physiological role of ZNF862 for the association with the HGF.

Synergistic Interface-Assisted Electrode-Electrolyte Coupling Toward Advanced Charge Storage.

Owing to the limited charge storage capability of transitional metal oxides in aqueous electrolytes, the use of redox electrolytes (RE) represents a promising strategy to further increase the energy density of aqueous batteries or pseudocapacitors. The usual coupling of an electrode and an RE possesses weak electrode/RE interaction and weak adsorption of redox moieties on the electrode, resulting in a low capacity contribution and fast self-discharge. In this work, Fe(CN)6 4- groups are grafted on the surface of Co3 O4 electrode via formation of CoN bonds, creating a synergistic interface between the electrode and the RE. With such an interface, the coupled Co3 O4 -RE system exhibits greatly enhanced charge storage from both Co3 O4 and RE, delivering a large reversible capacity of ≈1000 mC cm-2 together with greatly reduced self-discharge. The significantly improved electrochemical activity of Co3 O4 can be attributed to the tuned work function via charge injection from Fe(CN)6 4- , while the greatly enhanced adsorption of K3 Fe(CN)6 molecules is achieved by the interface induced dipole-dipole interaction on the liquid side. Furthermore, this enhanced electrode-electrolyte coupling is also applicable in the NiO-RE system, demonstrating that the synergistic interface design can be a general strategy to integrate electrode and electrolyte for high-performance energy storage devices.

Two novel fan-shaped trinuclear Pt(ii) complexes act as G-quadruplex binders and telomerase inhibitors.

Two new trinuclear Pt(ii) complexes {[Pt(dien)]3(tib)}(NO3)6 (1) and {[Pt(dpa)]3(tib)}(NO3)6 (2) (dien: diethylenetriamine, dpa: bis-(2-pyridylmethyl)amine, tib: 1,3,5-tris(1H-imidazol-1-yl)benzene) have been designed, synthesized, characterized and applied to a series of biochemical studies. We found that both of the Pt(ii) complexes exhibited much better selectivity for human telomeric G-quadruplex sequence than promoter G-quadruplexes (c-kit, c-myc, and bcl2) or duplex DNA. Both complexes displayed comparative stability and affinity towards human telomeric G-quadruplex by the studies from surface plasmon resonance, fluorescence resonance energy transfer and polymerase chain reaction stop assays. The circular dichroism indicated that both complexes could induce and stabilize anti-parallel G-quadruplex structures. Molecule docking presented that Pt(ii) complex intercalated into the large groove of human telomeric G-quadruplex (PDB ID: 143D). Furthermore, telomeric repeat amplification protocol assays quantitatively evaluated the inhibition of telomerase activity caused by the Pt(ii) complexes. The obtained IC50 values of 6.41 ± 0.042 µM and 2.67 ± 0.035 µM for 1 and 2, respectively, exhibited strong telomerase inhibitions. All results suggest that such fan-shaped trinuclear Pt(ii) complexes are effective and selective G-quadruplex binders, as well as strong telomerase inhibitors. This study provides insight into the development of human telomeric G-quadruplex targeted anticancer drugs based on the metal complex.

Birnessite Nanosheet Arrays with High K Content as a High-Capacity and Ultrastable Cathode for K-Ion Batteries.

Potassium-ion batteries (PIBs) are one of the emerging energy-storage technologies due to the low cost of potassium and theoretically high energy density. However, the development of PIBs is hindered by the poor K+ transport kinetics and the structural instability of the cathode materials during K+ intercalation/deintercalation. In this work, birnessite nanosheet arrays with high K content (K0.77 MnO2 ⋅0.23H2 O) are prepared by "hydrothermal potassiation" as a potential cathode for PIBs, demonstrating ultrahigh reversible specific capacity of about 134 mAh g-1 at a current density of 100 mA g-1 , as well as great rate capability (77 mAh g-1 at 1000 mA g-1 ) and superior cycling stability (80.5% capacity retention after 1000 cycles at 1000 mA g-1 ). With the introduction of adequate K+ ions in the interlayer, the K-birnessite exhibits highly stabilized layered structure with highly reversible structure variation upon K+ intercalation/deintercalation. The practical feasibility of the K-birnessite cathode in PIBs is further demonstrated by constructing full cells with a hard-soft composite carbon anode. This study highlights effective K+ -intercalation for birnessite to achieve superior K-storage performance for PIBs, making it a general strategy for developing high-performance cathodes in rechargeable batteries beyond lithium-ion batteries.

Achieving Insertion-Like Capacity at Ultrahigh Rate via Tunable Surface Pseudocapacitance.

The insertion/deinsertion mechanism enables plenty of charge-storage sites in the bulk phase to be accessible to intercalated ions, giving rise to at least one more order of magnitude higher energy density than the adsorption/desorption mechanism. However, the sluggish ion diffusion in the bulk phase leads to several orders of magnitude slower charge-transport kinetics. An ideal energy-storage device should possess high power density and large energy density simultaneously. Herein, surface-modified Fe2 O3 quantum dots anchored on graphene nanosheets are developed and exhibit greatly enhanced pseudocapacitance via fast dual-ion-involved redox reactions with both large specific capacity and fast charge/discharge capability. By using an aqueous Na2 SO3 electrolyte, the oxygen-vacancy-tuned Fe2 O3 surface greatly enhances the absorption of SO32- anions that majorly increase the surface pseudocapacitance. Significantly, the Fe2 O3 -based electrode delivers a high specific capacity of 749 C g-1 at 5 mV s-1 and retains 290 C g-1 at an ultrahigh scan rate of 3.2 V s-1 . With a novel dual-electrolyte design, a 2 V Fe2 O3 /Na2 SO3 //MnO2 /Na2 SO4 asymmetric supercapacitor is constructed, delivering a high energy density of 75 W h kg-1 at a power density of 3125 W kg-1 .

Effects of Population Bottleneck and Balancing Selection on the Chinese Alligator Are Revealed by Locus-Specific Characterization of MHC Genes.

Chinese alligator (Alligator sinensis) is an endangered freshwater crocodilian endemic to China, which experienced a severe bottleneck about 30 years ago. In this study, we developed locus-specific primers to investigate the polymorphism of 3 major histocompatibility complex (MHC) loci in 3 Chinese alligator populations, in combination with 6 neutral microsatellite markers as a contrast. We found the genetic trace for the bottleneck effect on the endangered Chinese alligator: the low allelic diversity (2 alleles at each locus), the low nucleotide substitution rate (no more than 0.009) at all sites, the deviation from Hardy-Weinberg Equilibrium/heterozygote deficiency, and the significant Tajima's D values, indicating the MHC class I and class II loci being at different stages of bottleneck. We also obtained 3 pieces of evidence for balancing selection on this severely bottlenecked reptile: an obvious excess of nonsynonymous substitutions over synonymous at the antigen-binding positions, the mean synonymous substitution rate of MHC exons significantly higher than mean nucleotide substitution rate of introns, and the differentiation coefficient F ST of MHC loci significantly lower than that of microsatellite loci. Consequently, we emphasize that the Chinese alligator holds a pretty low adaptive ability and requires scientific conservation strategies to ensure the long-term population development.

Phosphate Ion Functionalized Co3 O4 Ultrathin Nanosheets with Greatly Improved Surface Reactivity for High Performance Pseudocapacitors.

A surface-modified Co3 O4 ultrathin nanosheet (denoted as PCO) is reported via controllable phosphate ion functionalization for pseudocapacitors. An energy density of 71.6 W h kg-1 (at 1500 W kg-1 ) is achieved by the PCO-based pseudocapacitor. The unique porous nanosheet morphology, high surface reactivity, and fast electrode kinetics of PCO are found to be responsible for the enhanced pseudocapacitive performance.

Acid Treatment Enables Suppression of Electron-Hole Recombination in Hematite for Photoelectrochemical Water Splitting.

We report a strategy for efficient suppression of electron-hole recombination in hematite photoanodes. Acid-treated hematite showed a substantially enhanced photocurrent density compared to untreated samples. Electrochemical impedance spectroscopy studies revealed that the enhanced photocurrent is partly due to improved efficiency of charge separation. Transient absorption spectroscopic studies coupled to electrochemical measurements indicate that, in addition to improved bulk electrochemical properties, acid-treated hematite has significantly decreased surface electron-hole recombination losses owing to a greater yield of the trapped photoelectrons being extracted to the external circuit.

MnO2 nanomaterials for flexible supercapacitors: performance enhancement via intrinsic and extrinsic modification.

Increasing power and energy demands for next-generation portable and flexible electronics have raised critical requirements (flexibility, stretch-ability, environmental friendliness, lightweight, etc.) for the energy storage devices. Flexible supercapacitors (SCs), as one of the most promising next-generation energy storage devices, have stimulated intensive interest owing to their outstanding features including small size, low weight, ease of handling, excellent reliability, and high power density. Manganese oxide (MnO2), has attracted much interest in the development of flexible SCs with high electrochemical performance. Yet, the poor electronic and ionic transport in MnO2 electrodes still limits its promotion in practical applications. This review aims to describe the recent progress in the application of MnO2 materials in the development of flexible SCs and summarizes the intrinsic modification of MnO2via crystallinity, crystal structure, and oxygen vacancy introduction and the extrinsic modification of MnO2via non-three-dimensional (3D) and 3D flexible conductive scaffolds for high performance flexible SCs. Moreover, we also discuss briefly on the current challenges, future directions, and opportunities for the development of high-performance MnO2 based flexible SCs.

Hierarchical Fe3O4@Fe2O3 Core-Shell Nanorod Arrays as High-Performance Anodes for Asymmetric Supercapacitors.

Anode materials with relatively low capacitance remain a great challenge for asymmetric supercapacitors (ASCs) to pursue high energy density. Hematite (α-Fe2O3) has attracted intensive attention as anode material for ASCs, because of its suitable reversible redox reactions in a negative potential window (from 0 V to -1 V vs Ag/AgCl), high theoretical capacitance, rich abundance, and nontoxic features. Nevertheless, the Fe2O3 electrode cannot deliver large volumetric capacitance at a high rate, because of its poor electrical conductivity (∼10(-14) S/cm), resulting in low power density and low energy density. In this work, a hierarchical heterostructure comprising Fe3O4@Fe2O3 core-shell nanorod arrays (NRAs) is presented and investigated as the negative electrode for ASCs. Consequently, the Fe3O4@Fe2O3 electrode exhibits superior supercapacitive performance, compared to the bare Fe2O3 and Fe3O4 NRAs electrodes, demonstrating large volumetric capacitance (up to 1206 F/cm(3) with a mass loading of 1.25 mg/cm(2)), as well as good rate capability and cycling stability. The hybrid electrode design is also adopted to prepare Fe3O4@MnO2 core-shell NRAs as the positive electrode for ASCs. Significantly, the as-assembled 2 V ASC device delivered a high energy density of 0.83 mWh/cm(3) at a power density of 15.6 mW/cm(3). This work constitutes the first demonstration of Fe3O4 as the conductive supports for Fe2O3 to address the concerns about its poor electronic and ionic transport.

Photohole Induced Corrosion of Titanium Dioxide: Mechanism and Solutions.

Titanium dioxide (TiO2) has been extensively investigated as photoanode for water oxidation, as it is believed to be one of the most stable photoanode materials. Yet, we surprisingly found that TiO2 photoanodes (rutile nanowire, anatase nanotube, and P25 nanoparticle film) suffered from substantial photocurrent decay in neutral (Na2SO4) as well as basic (KOH) electrolyte solution. Photoelectrochemical measurements togehter with electron microscopy studies performed on rutile TiO2 nanowire photoanode show that the photocurrent decay is due to photohole induced corrosion, which competes with water oxidation reaction. Further studies reveal that photocurrent decay profile in neutral and basic solutions are fundamentally different. Notably, the structural reconstruction of nanowire surface occurs simultaneously with the corrosion of TiO2 in KOH solution resulting in the formation of an amorphous layer of titanium hydroxide, which slows down the photocorrosion. Based on this discovery, we demonstrate that the photoelectrochemical stability of TiO2 photoanode can be significantly improved by intentionally coating an amorphous layer of titanium hydroxide on the nanowire surface. The pretreated TiO2 photaonode exhibits an excellent photocurrent retention rate of 97% after testing in KOH solution for 72 h, while in comparison the untreated sample lost 10-20% of photocurrent in 12 h under the same measurement conditions. This work provides new insights in understanding of the photoelectrochemical stability of bare TiO2 photoanodes.

An Electrochemical Capacitor with Applicable Energy Density of 7.4 Wh/kg at Average Power Density of 3000 W/kg.

Electrochemical capacitors represent a new class of charge storage devices that can simultaneously achieve high energy density and high power density. Previous reports have been primarily focused on the development of high performance capacitor electrodes. Although these electrodes have achieved excellent specific capacitance based on per unit mass of active materials, the gravimetric energy densities calculated based on the weight of entire capacitor device were fairly small. This is mainly due to the large mass ratio between current collector and active material. We aimed to address this issue by a 2-fold approach of minimizing the mass of current collector and increasing the electrode performance. Here we report an electrochemical capacitor using 3D graphene hollow structure as current collector, vanadium sulfide and manganese oxide as anode and cathode materials, respectively. 3D graphene hollow structure provides a lightweight and highly conductive scaffold for deposition of pseudocapacitive materials. The device achieves an excellent active material ratio of 24%. Significantly, it delivers a remarkable energy density of 7.4 Wh/kg (based on the weight of entire device) at the average power density of 3000 W/kg. This is the highest gravimetric energy density reported for asymmetric electrochemical capacitors at such a high power density.

Effects of the size and morphology of zinc oxide nanoparticles on the germination of Chinese cabbage seeds.

The toxicity of four zinc oxide nanoparticles (i.e., spheric ZnO-30, spheric ZnO-50, columnar ZnO-90, and hexagon rod-like ZnO-150) to the seed germination of Chinese cabbage (Brassica pekinensis L.) was investigated in this study. The results showed that zinc oxide nanoparticles (nano-ZnOs) did not affect germination rates at concentrations of 1-80 mg/L but significantly inhibited the root and shoot elongation of Chinese cabbage seedlings, with the roots being more sensitive. The inhibition was evident mainly during seed incubation rather than the seed soaking process. Both the production of free hydroxyl groups (·OH) and the Zn bioaccumulation in roots or shoots resulted in toxicity of nano-ZnOs to Chinese cabbage seedlings. The toxicity of nano-ZnOs was affected significantly by their primary particle sizes in the minimum dimensionality, but large columnar ZnO-90 and small spherical ZnO-50 had comparable toxicities. Therefore, both the particle size and morphology affected the toxicity of nano-ZnOs.

A new benchmark capacitance for supercapacitor anodes by mixed-valence sulfur-doped V6O(13-x).

A new pseudocapacitor anode, sulfur-doped V6O(13-x), is reported. It achieves a benchmark capacitance of 1353 F/g (0.72 F/cm(2)) at a current density of 1.9 A/g (1 mA/cm(2)) in 5 M LiCl solution. The charges are stored chemically in the electrode via reversible redox reactions that involve multiple oxidation states of vanadium (V(3+), V(4+) and V(5+)).

Polyaniline and polypyrrole pseudocapacitor electrodes with excellent cycling stability.

Conducting polymers such as polyaniline and polypyrrole have been widely used as pseudocapacitive electrode materials for supercapacitors. However, their structural instability resulting from repeated volumetric swelling and shrinking during charge/discharge process has been a major hurdle for their practical applications. This work demonstrates a simple and general strategy to substantially enhance the cycling stability of conductive polymer electrodes by deposition of a thin carbonaceous shell onto their surface. Significantly, carbonaceous shell-coated polyaniline and polypyrrole electrodes achieved remarkable capacitance retentions of ∼95 and ∼85% after 10,000 cycles. Electron microscopy studies revealed that the presence of ∼5 nm thick carbonaceous shell can effective prevent the structural breakdown of polymer electrodes during charge/discharge process. Importantly, the polymer electrodes with a ∼5 nm thick carbonaceous shell exhibited comparable specific capacitance and pseudocapacitive behavior as the bare polymer electrodes. We anticipate that the same strategy can be applied for stabilizing other polymer electrode materials. The capability of fabricating stable polymer electrodes could open up new opportunities for pseudocapacitive devices.

Solid-state supercapacitor based on activated carbon cloths exhibits excellent rate capability.

Activated carbon cloth is used as an electrode, achieving an excellent areal capacitance of 88 mF/cm(2) (8.8 mF/g) without the use of any other capacitive materials. Significantly, when it is incorporated as part of a symmetric solid-state supercapacitor device, a remarkable charge/discharge rate capability is observed; 50% of the capacitance is retained when the charging rate increases from 10 to 10,000 mV/s.