Strain-retardant coherent perovskite phase stabilized Ni-rich cathode.

The use of state-of-the-art Ni-rich layered oxides (LiNixCoyMn1-x-yO2, x > 0.5) as the cathode material for lithium-ion batteries can push the energy and power density to a higher level than is currently available1,2. However, volume variation associated with anisotropic lattice strain and stress that is being developed during lithium (de)intercalation induces severe structural instability and electrochemical decay of the cathode materials, which is amplified further when the battery is operating at a high voltage (above 4.5 V), which is essential for unlocking its high energy3-6. Even after much effort by the research community, an intrinsic strain-retardant method for directly alleviating the continuous accumulation of lattice strain remains elusive. Here, by introducing a coherent perovskite phase into the layered structure functioning as a 'rivet', we significantly mitigate the pernicious structural evolutions by a pinning effect. The lattice strain evolution in every single cycle is markedly reduced by nearly 70% when compared with conventional materials, which significantly enhances morphological integrity leading to a notable improvement in battery cyclability. This strain-retardant approach broadens the perspective for lattice engineering to release the strain raised from lithium (de)intercalation and paves the way for the development of high-energy-density cathodes with long durability.

Origin of structural degradation in Li-rich layered oxide cathode.

Li- and Mn-rich (LMR) cathode materials that utilize both cation and anion redox can yield substantial increases in battery energy density1-3. However, although voltage decay issues cause continuous energy loss and impede commercialization, the prerequisite driving force for this phenomenon remains a mystery3-6 Here, with in situ nanoscale sensitive coherent X-ray diffraction imaging techniques, we reveal that nanostrain and lattice displacement accumulate continuously during operation of the cell. Evidence shows that this effect is the driving force for both structure degradation and oxygen loss, which trigger the well-known rapid voltage decay in LMR cathodes. By carrying out micro- to macro-length characterizations that span atomic structure, the primary particle, multiparticle and electrode levels, we demonstrate that the heterogeneous nature of LMR cathodes inevitably causes pernicious phase displacement/strain, which cannot be eliminated by conventional doping or coating methods. We therefore propose mesostructural design as a strategy to mitigate lattice displacement and inhomogeneous electrochemical/structural evolutions, thereby achieving stable voltage and capacity profiles. These findings highlight the significance of lattice strain/displacement in causing voltage decay and will inspire a wave of efforts to unlock the potential of the broad-scale commercialization of LMR cathode materials.

Deubiquitinase UCHL1 regulates estradiol synthesis by stabilizing voltage-dependent anion channel 2.

Lack of estradiol production by granulosa cells blocks follicle development, causes failure of estrous initiation, and results in an inability to ovulate. The ubiquitin-proteasome system plays a critical role in maintaining protein homeostasis and stability of the estrous cycle, but knowledge of deubiquitination enzyme function in estradiol synthesis is limited. Here, we observe that the deubiquitinase ubiquitin C-terminal hydrolase 1 (UCHL1) is more significant in estrous sows and high litter-size sows than in nonestrous sows and low-yielding sows. Overexpression of UCHL1 promotes estradiol synthesis in granulosa cells, and interference with UCHL1 has the opposite effect. UCHL1 binds, deubiquitinates, and stabilizes voltage-dependent anion channel 2 (VDAC2), promoting the synthesis of the estradiol precursor pregnenolone. Cysteine 90 (C90) of UCHL1 is necessary for its deubiquitination activity, and Lys45 and Lys64 in VDAC2 are essential for its ubiquitination and degradation. In vivo, compared with WT and sh-NC-AAV groups, the estrus cycle of female mice is disturbed, estradiol level is decreased, and the number of antral follicles is decreased after the injection of sh-UCHL1-AAV into ovarian tissue. These findings suggest that UCHL1 promotes estradiol synthesis by stabilizing VDAC2 and identify UCHL1 as a candidate gene affecting reproductive performance.

Decoupling the Synergy Between PGM and PGM-Free Moieties toward Oxygen Reduction Reaction.

Recently, coupling the conventional low Pt-group-metal (low-PGM, LP) and emerging PGM-free (PF) moiety to form a composite LP/PF catalyst is proposed to be an advanced strategy to improve the intrinsic activity and stability of oxygen reduction reaction (ORR) catalysts. Milestones in terms of ORR mass activity are created by this type of catalyst. However, the specific synergy between LP and PF moieties has not been well elucidated. Herein, two model catalysts are synthesized, i.e., atomically dispersed Co/N/C supporting Pt single atoms (Co/N/C@Pt-SAs) and PtCo nanoparticles (Co/N/C@PtCo-NPs). Interestingly, the Co/N/C@PtCo-NPs catalyst presents higher ORR mass activity prior to Co/N/C@Pt-SAs. This is theoretically due to the dual "built-in electric field" in Co/N/C@PtCo-NPs: one electric field with a direction from Pt to Co in NPs and another from Pt to Co/N/C; that is, Pt gains higher electron density in Co/N/C@PtCo-NPs than that in Co/N/C@Pt-SAs, thus forming an asymmetric electron cloud, and regulating the adsorption and activation of oxygen-containing species. In addition, the existence of Co significantly decreases the average valence state of PtCo NPs, indicating a stronger affinity between PtCo NPs and Co/N/C substrate, to account for the enhanced stability.

Selenium-Doped Sulfurized Polyacrylonitrile Hybrid Cathodes with Ultrahigh Sulfur Content for High-Performance Solid-State Lithium Sulfur Batteries.

The solid-state lithium sulfur battery (SSLSB) is an attractive next-generation energy storage system by reason of its remarkably high energy density and safety. However, the SSLSB still faces critical challenges, such as sluggish reaction kinetics, mismatched interface, and undesirable reversible capacity. Herein, a high-performance SSLSB is reported using sulfurized polyacrylonitrile with rich selenium-doped sulfur (Se/S-S@pPAN) as a cathode and poly(ethylene oxide)/Li7La3Zr1.4Ta0.6O12 (PEO-LLZTO) as an electrolyte. The sulfur content of the cathode up to 60.9 wt % can be achieved by dispersing selenium sulfide (SeSx) species in the sulfurized polyacrylonitrile (S@pPAN) skeleton at a molecular level. Selenium as a eutectic accelerator can be uniformly distributed in the composite through the Se-S bond and can accelerate the reaction kinetics. The PEO-LLZTO hybrid solid-state electrolyte (SSE) displays an attractive electrochemical performance and provides an intimate contact with electrodes. At 60 °C, Se/S-S@pPAN delivers an impressive discharge capacity of 1042 mAh g-1 at 0.1C and 445 mAh g-1 at 1C. Additionally, the LiFePO4 cathodes combined with PEO-LLZTO deliver a high reversible capacity (158.9 mAh g-1, 1C) and an ultralong lifespan (a capacity retention of 80%, 1000 cycles) at 1C. The synergetic design of the high-performance sulfur cathode and the organic/inorganic hybrid electrolyte is crucial for enabling the high-performance SSLSB.

Evolving aprotic Li-air batteries.

Lithium-air batteries (LABs) have attracted tremendous attention since the proposal of the LAB concept in 1996 because LABs have a super high theoretical/practical specific energy and an infinite supply of redox-active materials, and are environment-friendly. However, due to the lack of critical electrode materials and a thorough understanding of the chemistry of LABs, the development of LABs entered a germination period before 2010, when LABs research mainly focused on the development of air cathodes and carbonate-based electrolytes. In the growing period, i.e., from 2010 to the present, the investigation focused more on systematic electrode design, fabrication, and modification, as well as the comprehensive selection of electrolyte components. Nevertheless, over the past 25 years, the development of LABs has been full of retrospective steps and breakthroughs. In this review, the evolution of LABs is illustrated along with the constantly emerging design, fabrication, modification, and optimization strategies. At the end, perspectives and strategies are put forward for the development of future LABs and even other metal-air batteries.

Understanding the Synthesis Kinetics of Single-Crystal Co-Free Ni-Rich Cathodes.

Non-equilibrium kinetic intermediates are usually preferentially generated instead of thermodynamic stable phases in the solid-state synthesis of layered oxides. Understanding the inherent complexity between thermodynamics and kinetics is important for designing high cationic ordering cathodes. Single-crystal strategy is an effective way to solve the intrinsic chemo-mechanical problems of Ni-rich cathodes. However, the synthesis of high-performance single-crystal is very challenging. Herein, the kinetic reaction path and the formation mechanism of non-equilibrium intermediates in the synthesis of single-crystal Co-free Ni-rich were explored. We demonstrate that the formation of non-equilibrium intermediate and the electrochemical-thermo-mechanical failure can be effectively inhibited by driving low-temperature topotactic lithiation. This work provides a basis for designing high-performance single-crystal Ni-rich layered oxides by regulating the defective structures.

Accelerated Transfer and Spillover of Carbon Monoxide through Tandem Catalysis for Kinetics-boosted Ethylene Electrosynthesis.

Cu-based catalysts have been widely applied in electroreduction of carbon dioxide (CO2 ER) to produce multicarbon (C2+ ) feedstocks (e.g., C2 H4 ). However, the high energy barriers for CO2 activation on the Cu surface is a challenge for a high catalytic efficiency and product selectivity. Herein, we developed an in situ *CO generation and spillover strategy by engineering single Ni atoms on a pyridinic N-enriched carbon support with a sodalite (SOD) topology (Ni-SOD/NC) that acted as a donor to feed adjacent Cu nanoparticles (NPs) with *CO intermediate. As a result, a high C2 H4 selectivity of 62.5 % and an industrial-level current density of 160 mA cm-2 at a low potential of -0.72 V were achieved. Our studies revealed that the isolated NiN3 active sites with adjacent pyridinic N species facilitated the *CO desorption and the massive *CO intermediate released from Ni-SOD/NC then overflowed to Cu NPs surface to enrich the *CO coverage for improving the selectivity of CO2 ER to C2 H4 .

Identifying Luminol Electrochemiluminescence at the Cathode via Single-Atom Catalysts Tuned Oxygen Reduction Reaction.

Luminol-based electrochemiluminescence (ECL) can be readily excited by various reactive oxygen species (ROS) electrogenerated with an oxygen reduction reaction (ORR). However, the multiple active intermediates involved in the ORR catalyzed with complex nanomaterials lead to recognizing the role of ROS still elusive. Moreover, suffering from the absence of the direct electrochemical oxidation of luminol at the cathode and poor transformation efficiency of O2 to ROS, the weak cathodic ECL emission of luminol is often neglected. Herein, owing to the tunable coordination environment and structure-dependent catalytic feature, single-atom catalysts (SACs) are employed to uncover the relationship between the intrinsic ORR activity and ECL behavior. Interestingly, the traditionally negligible cathodic ECL of luminol is first boosted (ca. 70-fold) owing to the combination of electrochemical ORR catalyzed via SACs and chemical oxidation of luminol. The boosted cathodic ECL emission exhibits electron-transfer pathway-dependent response by adjusting the surrounding environment of the center metal atoms in a controlled way to selectively produce different active intermediates. This work bridges the relationship between ORR performance and ECL behavior, which will guide the development of an amplified sensing platform through rational tailoring of the ORR activity of SACs and potential-resolved ECL assays based on the high-efficiency cathodic ECL reported.

Platelet-to-lymphocyte ratio and C-reactive protein as markers for colorectal polyp histological type.

BACKGROUND: The platelet-to-lymphocyte ratio (PLR) and C-reactive protein (CRP) level are markers that have been reported to predict the histological type of various tumors, and here, we evaluated their utility in predicting colorectal polyp histological types. METHODS: We retrospectively reviewed 172 patients with colorectal polyps who underwent endoscopic polypectomy. The associations between histological type and clinicopathologic parameters were assessed by multivariate analysis. RESULTS: The optimal PLR and CRP cut-off values were 113.32 and 0.39, respectively. The PLR (P = 0.002) and CRP (P = 0.009) values were associated with the histological type according to the univariate analysis, whereas low PLR (P ≤ 0.001) and CRP (P = 0.017) values were independent risk factors in the multivariate analysis together with maximum tumor diameter (P ≤ 0.001) and tumor number (P = 0.0014). CONCLUSIONS: Preoperative PLR and CRP are correlated with the colorectal polyp histological type.

Broadband Tunable Mid-infrared Plasmon Resonances in Cadmium Oxide Nanocrystals Induced by Size-Dependent Nonstoichiometry.

A central theme of nanocrystal (NC) research involves synthesis of dimension-controlled NCs and studyof size-dependent scaling laws governing their optical, electrical, magnetic, and thermodynamic properties. Here, we describe the synthesis of monodisperse CdO NCs that exhibit high quality-factor (up to 5.5) mid-infrared (MIR) localized surface plasmon resonances (LSPR) and elucidate the inverse scaling relationship between carrier concentration and NC size. The LSPR wavelength is readily tunable between 2.4 and ∼6.0 µm by controlling the size of CdO NCs. Structural and spectroscopic characterization provide strong evidence that free electrons primarily originate from self-doping due to NC surface-induced nonstoichiometry. The ability to probe and to control NC stoichiometry and intrinsic defects will pave the way toward predictive synthesis of doped NCs with desirable LSPR characteristics.

Alloying Nickel with Molybdenum Significantly Accelerates Alkaline Hydrogen Electrocatalysis.

Bifunctional hydrogen electrocatalysis (hydrogen-oxidation and hydrogen-evolution reactions) in alkaline solution is desirable but challenging. Among all available electrocatalysts, Ni-based materials are the only non-precious-metal-based candidates for alkaline hydrogen oxidation, but they generally suffer from low activity. Here, we demonstrate that properly alloying Ni with Mo could significantly promote its electrocatalytic performance. Ni4 Mo alloy nanoparticles are prepared from the reduction of molybdate-intercalated Ni(OH)2 nanosheets. The final product exhibits an apparent hydrogen-oxidation activity exceeding that of the Pt benchmark and a record-high mass-specific kinetic current of 79 A g-1 at an overpotential of 50 mV. A superior hydrogen-evolution performance is also measured in alkaline solution. These experimental data are rationalized by our theoretical simulations, which show that alloying Ni with Mo significantly weakens its hydrogen adsorption, improves the hydroxyl adsorption and decreases the reaction barrier for water formation.

Structural Distortion Induced by Manganese Activation in a Lithium-Rich Layered Cathode.

The search for batteries with high energy density has highlighted lithium-rich manganese-based layered oxides due to their exceptionally high capacity. Although it is clear that both cationic and anionic redox are present in the charge compensation mechanism, the microstructural evolution of the Li2MnO3-like phase during anionic redox and its role in battery performance and structural stability are still not fully understood. Here, we systematically probe microstructural evolution using spatially resolved synchrotron X-ray measurements and reveal an underlying interaction between the Li2MnO3-like domains and bulk rhombohedral structure. Mn ion activation and a previously unobserved structural distortion are discovered at high voltages, and can be related to structural strain present in the Li2MnO3-like phase upon substantial lithium ion extraction. Moreover, we elucidate a correlation between this structural distortion and irreversible phase transitions by thermally perturbing delithiated samples. These insights highlight a pathway toward achieving high capacity cathode materials required for future commercial applications.

Architecting a Stable High-Energy Aqueous Al-Ion Battery.

Aqueous Al-ion batteries (AAIBs) are the subject of great interest due to the inherent safety and high theoretical capacity of aluminum. The high abundancy and easy accessibility of aluminum raw materials further make AAIBs appealing for grid-scale energy storage. However, the passivating oxide film formation and hydrogen side reactions at the aluminum anode as well as limited availability of the cathode lead to low discharge voltage and poor cycling stability. Here, we proposed a new AAIB system consisting of an AlxMnO2 cathode, a zinc substrate-supported Zn-Al alloy anode, and an Al(OTF)3 aqueous electrolyte. Through the in situ electrochemical activation of MnO, the cathode was synthesized to incorporate a two-electron reaction, thus enabling its high theoretical capacity. The anode was realized by a simple deposition process of Al3+ onto Zn foil substrate. The featured alloy interface layer can effectively alleviate the passivation and suppress the dendrite growth, ensuring ultralong-term stable aluminum stripping/plating. The architected cell delivers a record-high discharge voltage plateau near 1.6 V and specific capacity of 460 mAh g-1 for over 80 cycles. This work provides new opportunities for the development of high-performance and low-cost AAIBs for practical applications.

Dynamic Stabilization of Foam Films with Acoustic Sound.

This paper demonstrates the stabilization of single foam films at dynamic conditions induced by exposure to the acoustic sound. The foam films were formed from aqueous solutions using a Sheludko cell. In the presence of sound at certain sound frequencies and above certain thresholds of sound amplitude, the lifetime of the film with 1 × 10-4 M sodium dodecyl sulfate (SDS) in the presence of 0.1 M NaCl was significantly increased, and a stabilization map was drawn to show the three levels of film stability (i.e., unstable, metastable, and stable) obtained over a broad range of sound frequencies (1-19 kHz) and amplitudes (74-125 dB). In particular, stable films were observed at relatively high frequencies (14-19 kHz) and high amplitudes (>107 dB) and metastable films were observed at intermediate frequencies (8.8-9.3 kHz) and high amplitudes (>111 dB). The stabilization effect was also demonstrated with different surfactants at different concentrations, at different electrolyte concentrations (in the presence and absence of the surfactant), and at different temperatures. Image analysis suggested the presence of liquid flow within the films that were stabilized by exposure to the acoustic sound. The stabilization effect could be attributed to the hydrodynamic pressure arising at dynamic conditions.

Crystal-Growth-Dominated Fabrication of Metal-Organic Frameworks with Orderly Distributed Hierarchical Porosity.

Constructing architectures with hierarchical porosity has been widely considered as the most efficient way to bypass the problems related to slow mass transfer and inaccessibility of internal space in MOFs. Now, a crystal-growth-dominated strategy is proposed to fabricate hierarchically porous MOFs (HP-MOFs). When the crystal growth is dominated by the monomer attachment, the aggregation of nonionic surfactant or polymer can be easily captured and released during the crystal growth process, resulting in the formation and ordering hierarchical pores along the radial direction. Owing to the accelerated mass diffusion and more exposed active sites of this design, HP-MOFs exhibited an enhanced catalytic efficiency in styrene oxidation.

Thermal Emitting Strategy to Synthesize Atomically Dispersed Pt Metal Sites from Bulk Pt Metal.

Developing a facile route to access active and well-defined single atom sites catalysts has been a major area of focus for single atoms catalysts (SACs). Herein, we demonstrate a simple approach to generate atomically dispersed platinum via a thermal emitting method using bulk Pt metal as a precursor, significantly simplifying synthesis routes and minimizing synthesis costs. The ammonia produced by pyrolysis of Dicyandiamide can coordinate with platinum atoms by strong coordination effect. Then, the volatile Pt(NH3) x can be anchored onto the surface of defective graphene. The as-prepared Pt SAs/DG exhibits high activity for the electrochemical hydrogen evolution reaction and selective oxidation of various organosilanes. This viable thermal emitting strategy can also be applied to other single metal atoms, for example, gold and palladium. Our findings provide an enabling and versatile platform for facile accessing SACs toward many industrial important reactions.

Primary tumor-secreted VEGF induces vascular hyperpermeability in premetastatic lung via the occludin phosphorylation/ubiquitination pathway.

Primary tumor can induce the formation of premetastatic niche. The hyperpermeability of the vessels in the premetastatic niche is the first step in the development of metastasis. However, the cellular and molecular mechanisms of vascular hyperpermeability remain to be elucidated. In this study, 4T1 breast cells were injected into the breasts of mice to establish a tumor model. Our results showed that primary tumors induced hyperpermeability of the vessels in the premetastatic lung. Subsequent studies showed that the level of vascular endothelial growth factor (VEGF) was elevated in the tumor-bearing mice serum and the levels of tight junction (TJ) proteins occludin and ZO-1 were decreased in the premetastatic lung. In vitro studies demonstrated that VEGF increased the permeability of dextran and decreased the levels of occludin and ZO-1 in human umbilical vein endothelial cells. Moreover, the hyperpermeability of vessels and the degradation of occludin was blocked by bevacizumab. Overexpression of occludin alleviated the VEGF-induced hyperpermeability. Further investigations revealed that VEGF-induced occludin phosphorylation at Ser-490 and ubiquitination. Finally, we showed that VEGF accelerated the process of occludin degradation through the ubiquitin-proteasome system. In conclusion, primary tumor-secrete VEGF induce the occludin phosphorylation/ubiquitination and downregulation, resulting in the disruption of TJs and hyperpermeability of vessels in premetastatic lung. The occludin phosphorylation/ubiquitination pathway may be the mechanism of VEGF-induced vascular hyperpermeability in the lung premetastatic niche.

ZIF-8 with Ferrocene Encapsulated: A Promising Precursor to Single-Atom Fe Embedded Nitrogen-Doped Carbon as Highly Efficient Catalyst for Oxygen Electroreduction.

The oxygen reduction reaction (ORR) plays an important role in the fields of energy storage and conversion technologies, including metal-air batteries and fuel cells. The development of nonprecious metal electrocatalysts with both high ORR activity and durability to replace the currently used costly Pt-based catalyst is critical and still a major challenge. Herein, a facile and scalable method is reported to prepare ZIF-8 with single ferrocene molecules trapped within its cavities (Fc@ZIF-8), which is utilized as precursor to porous single-atom Fe embedded nitrogen-doped carbon (Fe-N-C) during high temperature pyrolysis. The catalyst shows a half-wave potential (E1/2 ) of 0.904 V, 67 mV higher than commercial Pt/C catalyst (0.837 V), which is among the best compared with reported results for ORR. Significant electrochemical properties are attributed to the special configuration of Fc@ZIF-8 transforming into a highly dispersed iron-nitrogen coordination moieties embedded carbon matrix.

Loss of ß-arrestin1 expression predicts unfavorable prognosis for non-small cell lung cancer patients.

We aimed to study the expression status of ß-arrestin1 in non-small cell lung cancer (NSCLC) specimens and its clinicopathologic significance. The correlation between ß-arrestin1 and the tumor migration biomarker E-cadherin, as well as smoking index were studied. A total of 152 patients with NSCLC who undergone surgery were enrolled. Altogether, 88 lung squamous cell lung cancer (SCC) specimens and 64 adenocarcinoma (ADC) specimens were tested for immunohistochemistry. Patients' survival was analyzed by the Kaplan-Meier method. Univariate and multivariate analyses were performed to determine independent prognostic factors. Spearman rank correlation test was used to show data associations. For SCC patients, the expression of ß-arrestin1 was either lost (56 of 88, 63.6 %) or low (32 of 88, 36.4 %), which was significantly and negatively associated with E-cadherin expression (P = 0.017). The similar correlation existed between smoking index and ß-arrestin1 expression (P = 0.044). For ADC patients, the deletion of ß-arrestin1 expression was rare (4 of 64, 6.3 %). Loss of ß-arrestin1 expression indicated poorer survival for both SCC (P = 0.026) and ADC patients (P = 0.006). ß-arrestin1 expression was detected in the other ADC specimens but showed no significant correlation with survival. In SCC patients, the loss expression of ß-arrestin1 was frequently observed, and ß-arrestin1 expression was significantly correlated with the smoking index and E-cadherin expression, which all indicated ß-arrestin1's significant clinicopathologic role. However, ß-arrestin1 was expressed in most ADC patients, but its clinicopathologic role seemed to be obscure and might need further exploration.