The development of flexible zinc‐air batteries (FZABs) has attracted broad attention in the field of wearable electronic devices. Gel electrolyte is one of the most important components in FZABs, ...which is urgent to be optimized to match with Zn anode and adapt to severe climates. In this work, a polarized gel electrolyte of polyacrylamide‐sodium citric (PAM‐SC) is designed for FZABs, in which the SC molecules contain large amount of polarized −COO− functional groups. The polarized −COO− groups can form an electrical field between gel electrolyte and Zn anode to suppress Zn dendrite growth. Besides, the −COO− groups in PAM‐SC can fix H2O molecules, which prevents water from freezing and evaporating. The polarized PAM‐SC hydrogel delivers a high ionic conductivity of 324.68 mS cm−1 and water retention of 96.85 % after being exposed for 96 h. FZABs with the PAM‐SC gel electrolyte exhibit long cycling life of 700 cycles at −40 °C, showing the application prospect under extreme conditions.
A polarized gel electrolyte of polyacrylamide‐sodium citric (PAM‐SC) is synthesized for flexible zinc‐air batteries. The polarized −COO− functional groups in gel electrolyte not only form an electrical field to suppress Zn dendrite growth, but also prevent water from freezing and evaporating. The FZABs with the PAM‐SC gel electrolyte exhibit long cycling life of 700 cycles at −40 °C, showing the application prospect under extreme conditions.
It is still very urgent and challenging to simultaneously develop high‐rate and long‐cycle oxide cathodes for sodium‐ion batteries (SIBs) because of the sluggish kinetics and complex multiphase ...evolution during cycling. Here, the concept of accurately manipulating structural evolution and formulating high‐performance heterostructured biphasic layered oxide cathodes by local chemistry and orbital hybridization modulation is reported. The P2‐structure stoichiometric composition of the cathode material shows a layered P2‐ and O3‐type heterostructure that is explicitly evidenced by various macroscale and atomic‐scale techniques. Surprisingly, the heterostructured cathode displays excellent rate performance, remarkable cycling stability (capacity retention of 82.16% after 600 cycles at 2 C), and outstanding compatibility with hard carbon anode because of the integrated advantages of intergrowth structure and local environment regulation. Meanwhile, the formation process from precursors during calcination and the highly reversible dynamic structural evolution during the Na+ intercalation/deintercalation process are clearly articulated by a series of in situ characterization techniques. Also, the intrinsic structural properties and corresponding electrochemical behavior are further elucidated by the density of states and electron localization function of density functional theory calculations. Overall, this strategy, which finely tunes the local chemistry and orbitals hybridization for high‐performance SIBs, will open up a new field for other materials.
An abnormal heterostructured biphasic layered oxide cathode for sodium‐ion batteries (SIBs) is successfully constructed, and its dynamic formation process, intrinsic structural properties, and electrochemical behavior are elucidated by a series of in situ characterization techniques and density functional theory calculations. The concept of accurately manipulating structural evolution and formulating heterostructured cathode materials by local chemistry and orbital hybridization modulation is further demonstrated.
Abstract
Fatty acids (FAs) are essential nutrients, but how they are transported into cells remains unclear. Here, we show that FAs trigger caveolae-dependent CD36 internalization, which in turn ...delivers FAs into adipocytes. During the process, binding of FAs to CD36 activates its downstream kinase LYN, which phosphorylates DHHC5, the palmitoyl acyltransferase of CD36, at Tyr91 and inactivates it. CD36 then gets depalmitoylated by APT1 and recruits another tyrosine kinase SYK to phosphorylate JNK and VAVs to initiate endocytic uptake of FAs. Blocking CD36 internalization by inhibiting APT1, LYN or SYK abolishes CD36-dependent FA uptake. Restricting CD36 at either palmitoylated or depalmitoylated state eliminates its FA uptake activity, indicating an essential role of dynamic palmitoylation of CD36. Furthermore, blocking endocytosis by targeting LYN or SYK inhibits CD36-dependent lipid droplet growth in adipocytes and high-fat-diet induced weight gain in mice. Our study has uncovered a dynamic palmitoylation-regulated endocytic pathway to take up FAs.
Sodium‐ion batteries (SIBs) are considered as a low‐cost complementary or alternative system to prestigious lithium‐ion batteries (LIBs) because of their similar working principle to LIBs, ...cost‐effectiveness, and sustainable availability of sodium resources, especially in large‐scale energy storage systems (EESs). Among various cathode candidates for SIBs, Na‐based layered transition metal oxides have received extensive attention for their relatively large specific capacity, high operating potential, facile synthesis, and environmental benignity. However, there are a series of fatal issues in terms of poor air stability, unstable cathode/electrolyte interphase, and irreversible phase transition that lead to unsatisfactory battery performance from the perspective of preparation to application, outside to inside of layered oxide cathodes, which severely limit their practical application. This work is meant to review these critical problems associated with layered oxide cathodes to understand their fundamental roots and degradation mechanisms, and to provide a comprehensive summary of mainstream modification strategies including chemical substitution, surface modification, structure modulation, and so forth, concentrating on how to improve air stability, reduce interfacial side reaction, and suppress phase transition for realizing high structural reversibility, fast Na+ kinetics, and superior comprehensive electrochemical performance. The advantages and disadvantages of different strategies are discussed, and insights into future challenges and opportunities for layered oxide cathodes are also presented.
Recent progress in layered oxide cathodes for sodium‐ion batteries (SIBs) from air stability, interface chemistry, and phase transition are comprehensively summarized. The intrinsic degradation mechanisms behind electrochemical performance and mainstream modification strategies are systematically sorted out and analyzed. The remaining challenges, promising optimization strategies as well as endeavor directions to break current limitations are also presented for the future design of high‐performance layered oxide cathodes for SIBs.
Patient‐specific induced pluripotent stem cells (iPSCs) represent a potential source for developing novel drug and cell therapies. Although increasing numbers of disease‐specific iPSCs have been ...generated, there has been limited progress in iPSC‐based drug screening/discovery for liver diseases, and the low gene‐targeting efficiency in human iPSCs warrants further improvement. Using iPSC lines from patients with alpha‐1 antitrypsin (AAT) deficiency, for which there is currently no drug or gene therapy available, we established a platform to discover new drug candidates and correct disease‐causing mutation with a high efficiency. A high‐throughput format screening assay, based on our hepatic differentiation protocol, was implemented to facilitate automated quantification of cellular AAT accumulation using a 96‐well immunofluorescence reader. To expedite the eventual application of lead compounds to patients, we conducted drug screening utilizing our established library of clinical compounds (the Johns Hopkins Drug Library) with extensive safety profiles. Through a blind large‐scale drug screening, five clinical drugs were identified to reduce AAT accumulation in diverse patient iPSC‐derived hepatocyte‐like cells. In addition, using the recently developed transcription activator‐like effector nuclease technology, we achieved high gene‐targeting efficiency in AAT‐deficiency patient iPSCs with 25%‐33% of the clones demonstrating simultaneous targeting at both diseased alleles. The hepatocyte‐like cells derived from the gene‐corrected iPSCs were functional without the mutant AAT accumulation. This highly efficient and cost‐effective targeting technology will broadly benefit both basic and translational applications. Conclusions: Our results demonstrated the feasibility of effective large‐scale drug screening using an iPSC‐based disease model and highly robust gene targeting in human iPSCs, both of which are critical for translating the iPSC technology into novel therapies for untreatable diseases. (HEPATOLOGY 2013;57:2458–2468)
•Inexpensive Al2O3/C3N4 hybrid with high visible light activity is firstly reported.•Defect sites existed in amorphous Al2O3 are excellent electron acceptors.•G-C3N4 is surface modified by NH4OH to ...enhance hydroxyl groups.•The role of hydroxyl in the formation process of g-C3N4-based hybrids is discussed.•The reason responsible for the surface positive charges of Al2O3 is presented.
Novel Al2O3/g-C3N4 heterojunction photocatalysts were fabricated through ultrasonic dispersion method. Al2O3, obtained via solution combustion, contained amorphous ingredient with lots of defect sites and was used as active component for transferring photo-induced electrons of g-C3N4. G-C3N4 was grafted surface hydroxyl groups in the presence of ammonia aqueous solution to combine with Al2O3 possessing positive charges via hydrogen bond. The XRD, SEM, element map, TEM, HRTEM, FT-IR, and XPS results indicate that these synthesized materials are two-phase hybrids of Al2O3 and g-C3N4 with interaction. The photocatalytic results for the degradation of rhodamine B (RhB) indicate that the most active heterojunction proportion is 60wt.% g-C3N4:40wt.% Al2O3, the visible light photocatalytic activity of which is 3.8 times that of a mechanical mixture. The enhanced performance is attributed to the high separation efficiency of photo-induced electrons from the LUMO of g-C3N4 injected into the defect sites of Al2O3, which is verified by photoluminescence spectroscopy (PL) and surface photovoltage (SPV) measurements. The electron paramagnetic resonance (EPR) signals and radical scavengers trapping experiments reveal holes (h+) and superoxide anion radical (O2−) are the main active species responsible for the degradation of RhB.
We reported a large Chinese family diagnosed with autosomal dominant tubulointerstitial kidney disease caused by MUC1 mutation (ADTKD-MUC1). Cytosine duplication within a string of 7 cytosines in the ...variable-number tandem repeats (VNTR) region of the MUC1 gene was detected by long-read single-molecule real-time (SMRT) sequencing. MUC1 frameshift protein (MUC1fs) was found to be expressed in renal tubules and urinary exfoliated cells by pathological examination. The family, which consisted of 5 generations including 137 individuals, was followed for 5 years. Genetic testing was performed in thirty-four individuals, 17 of whom carried MUC1 mutations. The ADTKD-MUC1-affected individuals had an elevated incidence of hyperuricaemia without gout attack. Within five years, higher baseline levels of urinary α1-microglobulin were detected in affected individuals with rapidly progressing renal failure than in affected individuals with stable renal function, and the increases manifested even before increases in serum creatinine. This study demonstrates that SMRT sequencing is an effective method for the identification of MUC1 mutations. The pathological examination of MUC1fs expression in renal tissue and urinary exfoliated cells can contribute to early screening of family members suspected to be affected. It is suggested that affected individuals with elevated urinary α1-microglobulin levels should be closely monitored for renal function.
Insulin resistance is a major risk factor for type 2 diabetes mellitus. The protein encoded by the sirtuin 1 (Sirt1) gene, which is a mouse homolog of yeast Sir2, is implicated in the regulation of ...glucose metabolism and insulin sensitivity; however, the underlying mechanism remains elusive. Here, using mice with a liver-specific null mutation of Sirt1, we have identified a signaling pathway involving Sirt1, Rictor (a component of mTOR complex 2 mTorc2), Akt, and Foxo1 that regulates gluconeogenesis. We found that Sirt1 positively regulates transcription of the gene encoding Rictor, triggering a cascade of phosphorylation of Akt at S473 and Foxo1 at S253 and resulting in decreased transcription of the gluconeogenic genes glucose-6-phosphatase (G6pase) and phosphoenolpyruvate carboxykinase (Pepck). Liver-specific Sirt1 deficiency caused hepatic glucose overproduction, chronic hyperglycemia, and increased ROS production. This oxidative stress disrupted mTorc2 and impaired mTorc2/Akt signaling in other insulin-sensitive organs, leading to insulin resistance that could be largely reversed with antioxidant treatment. These data delineate a pathway through which Sirt1 maintains insulin sensitivity and suggest that treatment with antioxidants might provide protection against progressive insulin resistance in older human populations.
Bayan Obo ore deposit is the largest rare-earth element（REE） resource,and the second largest niobium（Nb） resource in the world.Due to the complicated element/mineral compositions and involving ...several geological events,the REE enrichment mechanism and genesis of this giant deposit still remains intense debated.The deposit is hosted in the massive dolomite,and nearly one hundred carbonatite dykes occur in the vicinity of the deposit.The carbonatite dykes can be divided into three types from early to late：dolomite,co-existing dolomite-calcite and calcite type,corresponding to different evolutionary stages of carbonatite magmatism based on the REE and trace element data.The latter always has higher REE content.The origin of the ore-hosting dolomite at Bayan Obo has been addressed in various models,ranging from a normal sedimentary carbonate rocks to volcano-sedimentary sequence,and a large carbonatitic intrusion.More geochemical evidences show that the coarse-grained dolomite represents a Mesoproterozoic carbonatite pluton and the fine-grained dolomite resulted from the extensive REE mineralization and modification of the coarse-grained variety.The ore bodies,distributed along an E-W striking belt,occur as large lenses and underwent more intense fluoritization and fenitization.The first episode mineralization is characterized by disseminated mineralization in the dolomite.The second or main-episode is banded and/or massive mineralization,cut by the third episode consisting of aegirinerich veins.Various dating methods gave different mineralization ages at Bayan Obo,resulting in long and hot debates.Compilation of available data suggests that the mineralization is rather variable with two peaks at～1400 and 440 Ma.The early mineralization peak closes in time to the intrusion of the carbonatite dykes.A significant thermal event at ca.440 Ma resulted in the formation of late-stage veins with coarse crystals of REE minerals.Fluids involving in the REE-Nb-Fe mineralization at Bayan Obo might be REE-F-C02-NaCI-H20 system.The presence of REE-carbonates as an abundant solid in the ores shows that the original ore-forming fluids are very rich in REE,and therefore,have the potential to produce economic REE ores at Bayan Obo.the Bayan Obo deposit is a product of mantle-derived carbonatitic magmatism at ca.1400 Ma,which was likely related to the breakup of Columbia.Some remobilization of REE occurred due to subduction of the Palaeo-Asian oceanic plate during the Silurian,forming weak vein-like mineralization.
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