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Considerable efforts have been devoted to Li-S batteries, typically the soluble polysulfides shuttling effect. As a typical transition metal sulfide, MoS2 is a magic bullet for addressing the issues of Li-S batteries, drawing increasing attention. In this study, we introduce amorphous MoS3 as analogous sulfur cathode material and elucidate the dynamic phase evolution in the electrochemical reaction. The metallic 1T phase incorporated 2H phase MoS2 with sulfur vacancies (SVs-1T/2H-MoS2) decomposed from amorphous MoS3 achieves refined mixing with the "newborn" sulfur at the molecular level and supplies continuous conduction pathways and controllable physical confinement. Meanwhile, the in situ-generated SVs-1T/2H-MoS2 allows lithium intercalation in advance at high discharge voltage (≥1.8 V) and enables fast electron transfer. Moreover, aiming at the unbonded sulfur, diphenyl diselenide (PDSe), as a model redox mediator is applied, which can covalently bond sulfur atoms to form conversion-type organoselenosulfides, changing the original redox pathway of "newborn" sulfur in MoS3, and suppressing the polysulfides shuttling effect. It also significantly lowers the activation energy and thus accelerates the sulfur reduction kinetics. Thus, the in situ-formed intercalation-conversion hybrid electrode of SVs-1T/2H-MoS2 and organoselenosulfides realizes enhanced rate capability and superior cycling stability. This work provides a novel concept for designing high-energy-density electrode materials.
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Regioselective benzanilide bromination that generates either regioisomer from the same starting material is desirable. Herein, we develop switchable site-selective C(sp2)-H bromination by promoter regulation. This protocol leads to regiodivergent brominated benzanilide starting from the single substrate via selection of promoters. The protocol demonstrates excellent regioselectivity and good tolerance of functional groups with high yields. The utility effectiveness of this method has been well exemplified in the late-stage modification of biologically important molecules.
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The sluggish kinetics of lithium-sulfur (Li-S) batteries severely impedes the application in extreme conditions. Bridging the sulfur cathode and lithium anode, the electrolyte plays a crucial role in regulating kinetic behaviors of Li-S batteries. Herein, we report a multifunctional electrolyte additive of phenyl selenium bromide (PhSeBr) to simultaneously exert positive influences on both electrodes and the electrolyte. For the cathode, an ideal conversion routine with lower energy barrier can be attained by the redox mediator and homogeneous catalyst derived from PhSeBr, thus improving the reaction kinetics and utilization of sulfur. Meanwhile, the presence of Se-Br bond helps to reconstruct a loose solvation sheath of lithium ions and a robust bilayer SEI with excellent ionic conductivity, which contributes to reducing the de-solvation energy and simultaneously enhancing the interfacial kinetics. The Li-S battery with PhSeBr displays superior long cycling stability with a reversible capacity of 1164.7â mAh g-1 after 300â cycles at 0.5â C rate. And the pouch cell exhibits a maximum capacity of 845.3â mAh and a capacity retention of 94.8 % after 50â cycles. Excellent electrochemical properties are also obtained in extreme conditions of high sulfur loadings and low temperature of -20 °C. This work demonstrates the versatility and practicability of the special additive, striking out an efficient but simple method to design advanced Li-S batteries.
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Achieving high energy density and long cycle life in realistic batteries is still an unmet need, which has triggered research into the discoveries of new electrode materials as well as new storage mechanisms. As a kind of new cathode materials for rechargeable lithium batteries, organosulfide compounds R-Sn -R (n = 3-6) based on conversion chemistries of SS bonds have many advantages and promising prospects; however, poor electric/ionic conductivity and sluggish redox kinetics is a major hinder for their applications. Here an organic-inorganic hybrid cathode by introducing 1T MoS2 grown on reduced graphene oxide to hybridize with phenyl tetrasulfide (Ph-S4 -Ph, theoretical specific capacity 570 mAh g-1 ), enhancing the battery performance is reported. This includes the improved charge transfer, stable long cycles, and close-to-practical energy density in coin cells and pouch cells, which also show high mass loadings and contents, and low electrolyte dependence. Furthermore, the dynamic 1T-2H mixed-phase during the charge/discharge is revealed to be critical for the improved performance. This study proves the hybrid nanomaterials as a promising solution to address the challenges facing lithium-organosulfide batteries.
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Great efforts have been made to tackle the issues of the shuttle effect and kinetics hysteresis in lithium-sulfur (Li-S) battery, but few on tuning the reaction path of sulfur cathode. Herein, we report a strategy to replace inorganic sulfur with liquid organosulfide and construct a novel liquid-liquid interface between cathode and electrolyte, which effectively inhibits the shuttle effect and simplifies the solid-liquid-solid conversion reaction to only liquid-solid process, thus greatly improving the reaction kinetics. The Li|PTS half-cell exhibits excellent cycling stability at 0.5â C, with a capacity retention of 64.9 % after 750 cycles. The Li|PTS pouch cell with a high PTS loading of 3.1â g delivers a maximum capacity of 997â mAh and maintains 82.1 % of initial capacity after 50 cycles at the current of 100â mA. This work enriches the reaction mechanism of Li-S batteries and provides new insights for the development of interphase chemistry in the design of cathodes.
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BACKGROUND: H type hypertension is defined as homocysteine (Hcy) ≥ 10 µmol/L in combination with primary hypertension. Studies demonstrated that the existence of hyperhomocysteine (HHcy) in hypertensive exacerbates the poor outcome of cardiocerebral incidents. This study was to investigate the current epidemic situation of H type hypertension and determine the risk factors in order to find intervention targets for H type hypertensives. METHODS: We conducted a cross-sectional study using cluster sampling design in Shanghai, China from July 2019 and April 2020. 23,652 patients with primary hypertension were enrolled in this study. Their medical information was recorded, and the level of Hcy concentrations and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphisms were detected. RESULTS: In total, 22,731 of 23,652 patients were recorded. The mean age was 68.9 ± 8.6 y and 43% were men. 80.0% of the enrolled patients had H type hypertension. The frequency of allele T was 40.9%, and the proportions of the CC, CT, and TT genotypes were 36.1%, 46.0%, and 17.9%, respectively. Compared with the TT genotype, the plasma Hcy concentration levels were lower in patients with the CC/CT genotype (18.96 ± 13.48 µmol/L vs. 13.62 ± 5.20/14.28 ± 5.36, F = 75.04, p < 0.01). The risk for H type hypertension was higher in elderly people. Men had ~ 5.55-fold odds of H type hypertension compared with women. Patients with CT genotype and TT genotype had ~ 1.36- and ~ 2.76-fold odds of H type hypertension compared with those with CC genotype, respectively. Smoking and diabetes were not significantly associated with H type hypertension. CONCLUSIONS: The prevalence of H type hypertension in patients with primary hypertension was 80.0%, which was higher than the 75% found in prior report in China. Age, gender, and MTHFR C677T polymorphisms rather than smoking and diabetes were independently associated with H type hypertension.
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Genotipo , Homocisteína/sangre , Hipertensión/sangre , Hipertensión/epidemiología , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Adulto , Anciano , Anciano de 80 o más Años , China/epidemiología , Estudios Transversales , Femenino , Humanos , Hiperhomocisteinemia/complicaciones , Hipertensión/genética , Masculino , Persona de Mediana Edad , Polimorfismo Genético , Prevalencia , Factores de RiesgoRESUMEN
Constructing carbonaceous materials with versatile surface structures still remains a great challenge due to limited self-assembly methods, especially at high temperatures. This study presents an innovative template evolution induced relay self-assembly (TEIRSA) for the fabrication of large polyoxometalate (POM)-mixed carbonaceous nanosheets featuring surface mesoporous structures through hydrothermal carbonization (HTC). The method employs POM and acetone as additives, cleverly modulating the Ostwald ripening-like process of P123-based micelles, effectively addressing the instability challenges inherent in traditional soft-template methods, especially within the demanding carbohydrate HTC process. Additionally, this method allows for the independent regulation of surface architectures through the selection of organic additives. The resulting nanosheets exhibit diverse surface morphologies, including surface spherical mesopores, 1D open channels, and smooth surfaces. Their unexpectedly versatile properties have swiftly garnered recognition, showing potential in the application of lithium-sulfur batteries.
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Maternal embryonic leucine zipper kinase (MELK) is a novel target for the treatment of various kinds of B-cell malignancies. However, the toxicity of inhibitors of MELK has led to clinical failures in cancer treatments. Moreover, inactivation of MELK catalytic domain is insufficient for achieving cancer cell apoptosis. To further confirm the role of MELK in Burkitt lymphoma treatment, we describe herein a structure-guided design of PROTACs targeting MELK. Through design, computer-assisted optimization and SAR studies, we developed the first-in-class MELK-targeting PROTAC MGP-39, which promoted a rapid and potent degradation of MELK in RAMOS cells. Additionally, the newly designed MELK degrader induced significant cell cycle arrest and apoptosis in cancer cells. Notably, compared to MELK inhibitors, MGP-39 has better anti-cancer activity and lower toxicity, indicating the practical role of PROTACs in avoiding the side effects of traditional inhibitors. More importantly, our results show that the use of a PROTAC can be adopted as a general and effective strategy for targeted cancer therapy.
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Enhancing the selectivity of alpha2-adrenoceptor (α2A-AR) agonists remains an unresolved issue. Herein, we reported the design of an α2A-AR agonist using the conformation constraint method, beginning with medetomidine. The structure-activity relationship indicated that the 8-substituent of chromane derivatives exerted the most pronounced effect on α2A-AR agonistic activity. Compounds A9 and B9 were identified as the most promising, exhibiting EC50 values of 0.78 and 0.23 nM, respectively. Their selectivity indexes surpassed dexmedetomidine (DMED) by 10-80 fold. In vivo studies demonstrated that both A9 and B9 dose-dependently increased the loss of righting reflex in mice, with ED50 values of 1.54 and 0.138 mg/kg, respectively. Binding mode calculations and mutation studies suggested the indispensability of the hydrogen bond between ASP1283.32 and α2A-AR agonist. In particular, A9 and B9 showed no dual reverse pharmacological effect, a characteristic exhibited by DMED in α2A-AR activation.
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Agonistas de Receptores Adrenérgicos alfa 2 , Cromanos , Diseño de Fármacos , Receptores Adrenérgicos alfa 2 , Animales , Receptores Adrenérgicos alfa 2/metabolismo , Cromanos/farmacología , Cromanos/química , Cromanos/síntesis química , Relación Estructura-Actividad , Ratones , Agonistas de Receptores Adrenérgicos alfa 2/farmacología , Agonistas de Receptores Adrenérgicos alfa 2/química , Humanos , Conformación Molecular , Simulación del Acoplamiento Molecular , MasculinoRESUMEN
Refractory high-entropy alloy nanocomposites (HEA-NPs) are important class of materials with unique structure and potential applications. Although several synthetic methods have been reported, developing novel routes to prepare nanoscale HEA-based catalysts facilely is still urgently desired. This work takes advantage of confinement assisted arc and plasma shock (APS) to prepare a series of HEA-NPs by regulating the type and proportion of metal precursors. The phase constitutes and morphology of the HEA-NPs are fully characterized. The prepared refractory HEA-NPs possesses five highly dispersed metal components, including titanium (Ti), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo) and simultaneously exhibits an uniform hexagonal morphology of nanocrystals. By taking advantage of its unique corrosion resistance, TiNbTaCrMo HEA-NPs can function as a promising candidate for electrocatalytic hydrogen evolution reaction (HER) in natural seawater. And its catalytic performance after alloying is significantly enhanced compared with the elemental metal. Theoretically, the promoted HER activity can be attributed to the strong adsorption for the various metal components in HEA-NPs caused by the upshifting d-band center close to the Fermi level. Furthermore, this confinement strategy can be further extended to synthesize other HEA-NPs. Our strategy provides a novel method to synthesize various HEA-NPs for further catalytic application.
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The objectives of this study are to assess the healing score (HS) and neointimal thickness of the Xinsorb scaffold, and explore the relationships between the implanted patterns, neointimal thickness, and HS. The Xinsorb bioresorbable sirolimus-eluting scaffold is the first domestically designed and fabricated bioresorbable scaffold in China. The 6-month follow-up found it to be safe and effective in the treatment of single de novo coronary lesions. The Xinsorb scaffolds were implanted in 30 patients with symptomatic ischemic coronary disease. A 6-month follow-up was performed in a subset of 19 patients; the HS and neointimal thickness were evaluated by optical coherence tomography. Struts were classified as ApposedCovered, ApposedUncovered, MalapposedCovered, MalapposedUncovered, jailing and presence of intraluminal masses. The implanted pressure, implanted duration, and post-expansion pressure were recorded during the operation. We evaluated the relationship between the HS or neointimal thickness and the implanted pressure, holding time, and post-expansion pressure. The device and procedure success rates were both 100%. No major adverse cardiac or scaffold-thrombus related events occurred. At 6 months, 12,295 struts were analyzed to determine the HS (6.23) and neointimal thickness (0.1021 ± 0.05718 mm) in the Xinsorb scaffolds. There was a strong negative relationship between the HS and the implantation duration (Pearson r = - 0.518, p = 0.023). A significant negative relationship also existed between the HS and post-dilatation (Pearson r = - 0.631, p = 0.004). The Xinsorb scaffold HS appears negative correlated with the implanted duration and post-dilatation. We will further evaluate the HS of randomized controlled trial of the Xissorb scaffold.