查找使用阿拉丁产品的科研文献

Identification of 20(S)-Ginsenoside Rh2 as a Potential EGFR Tyrosine Kinase Inhibitor

Yuan Liang,Jingqi Zhao,Haoyang Zou,Jie Zhang,Tiehua Zhang

As the main active ingredients of Panax ginseng, ginsenosides possess numerous bioactivities. Epidermal growth factor receptor (EGFR) was widely used as a valid target in anticancer therapy. Herein, the EGFR targeting activities of 20(S)-ginsenoside Rh2 (20(S)-Rh2) and the relationship of their structure-activity were investigated. Homogeneous time-resolved fluorescence assay showed that 20(S)-Rh2 significantly inhibited the activity against EGFR kinase. 20(S)-Rh2 was confirmed to effectively inhibited cell proliferation in a dose-dependent manner by MTT assay. Furthermore, quantitative real-time PCR and western blotting analysis revealed that 20(S)-Rh2 inhibited A549 cells growth via the EGFR-MAPK pathway. Meanwhile, 20(S)-Rh2 could promote cell apoptosis, block cell cycle, and reduce cell migration of A549 cells, respectively. In silico, the result suggested that both hydrophobic interactions and hydrogen-bonding interactions could contribute to stabilize their binding. Molecular dynamics simulation showed that the side chain sugar moiety of 20(S)-Rh2 was too flexible to be fixed at the active site of EGFR. Collectively, these findings suggested that 20(S)-Rh2 might serve as a potential EGFR tyrosine kinase inhibitor.

Long-Pursued Structure of Au23(S-Adm)16 and the Unexpected Doping Effects

Lei Feng,Ze-Min Zhu,Ying Yang,Zongbin He,Jiafeng Zou,Man-Bo Li,Yan Zhao,Zhikun Wu

Metal nanoclusters are rising stars in material science , and one advantage is their atomically precise tunability. It is well known that metal doping can efficiently modify the properties of metal nanoclusters. In particular, without altering the parent nanocluster framework, doping a single heterometal atom can tailor the properties of metal nanoclusters and aid investigations of the structure–property relationship of metal nanoclusters. To our knowledge, the simultaneous synthesis of a single heterometaldoped nanocluster and its parent nanocluster is challenging and has not been previously reported; however, this is highly desirable because it can prevent the influence of trace impurities and allow comparison between doped and undoped nanoclusters. The single Cd-doped gold nanocluster Au 22 Cd 1 (S-Adm) 16 (S-Adm = 1-adamantanethiolate) has been previously synthesized and structurally elucidated. However, the structure of the parent nanocluster, Au 23 (S-Adm) 16 , remains unknown, inspiring this investigation. In this study, we synthesized Au 23 (S-Adm) 16 and its single-doped Au 22 Cd 1 (S-Adm) 16 nanocluster in one pot for the first time, and we resolved their structures using single-crystal X-ray crystallography. The structure of Au 22 Cd 1 (S-Adm) 16 is similar to that of Au 23 (S-Adm) 16 except that a kernel Au atom in Au 23 (S-Adm) 16 is replaced with a Cd atom. This Cd replacement causes the kernel Au―Au bond length to increase owing to the loosening of the original closely packed structure. In contrast to prior reports, Au 23 (S-Adm) 16 is surprisingly more stable than Au 22 Cd 1 (S-Adm) 16 , as determined via ultraviolet visible-near infrared (UV-Vis-NIR) spectroscopy at 80 °C. This stability was attributed to the decrease in the kernel Au―Au bond length. Although the maximum absorption of Au 22 Cd 1 (S-Adm) 16 slightly red-shifted from 605 to 608 nm after Cd doping, the molar extinction coefficient of Au 23 (S-Adm) 16 at 605 nm was approximately twice that of Au 22 Cd 1 (S-Adm) 16 at 608 nm. Thus, the increase in kernel Au―Au bond length may decrease the photoexcitation electron transfer efficiency owing to lengthening of the photoexcitation electron transfer pathway. As further support for this opinion, although the two nanoclusters showed similar emission profiles and maxima (750 nm for Au 23 (S-Adm) 16 and 760 nm for Au 22 Cd 1 (S-Adm) 16 ), they exhibited obvious emission intensity differences. Specifically, the quantum yield of Au 23 (S-Adm) 16 (approximately 3.160 × 10 −5 ) was found to be 1.13 times that of Au 22 Cd 1 (S-Adm) 16 (approximately 2.793 × 10 −5 ). Thus, the stability and absorption and emission intensities correlate with the kernel Au―Au bond length. This study shows that two metal nanoclusters with slight structural differences can exhibit different properties in terms of optical and thermal stability, providing a good reference for studying their structure–property relationships. Download: Download high-res image (68KB) Download: Download full-size image

Crosslinked polyacrylonitrile precursor for S@pPAN composite cathode materials for rechargeable lithium batteries

Jingyu Lei,Huichao Lu,Jiahang Chen,Jun Yang,Yanna Nuli,Jiulin Wang

S@pPAN has become promising cathode materials in rechargeable batteries due to its high compressed density, low E/S ratio, no polysulfide dissolution, no self-discharge, and stable cycling. However, it is a big challenge to enhance its sulfur content which determines its practical specific capacity. Herein, we prepare crosslinked PAN as precursor, leading to effective enhancement of sulfur content up to 55 wt% and a reversible specific capacity of 838 mAh g -1 composites at 0.2C. Because of the microporous structure and high specific area, crosslinked PAN provides more space to accommodate sulfur molecule and improve the interfacial reaction of S@pPAN as well. This work provides a promising direction to design S@pPAN for lithium sulfur batteries with high energy density.

Amino-functionalized SiO2 modified porous polyetherimide separator for high performance Li-S batteries

Jiuqing Liu,Fanli Zeng,Meng Liu,Junying He,Qihou Li,Feifei Song,Zikun Hong,Ya Chen,Lishun Bai,Chen Cheng,Zehao Chen

Summary As one of the most promising energy storage systems, the application of lithium sulfur battery is hindered by low ionic conductivity, poor thermal stability, and a serious shuttle effect of polysulfide species of commercial polyolefin separators. Herein, a kind of novel porous polyetherimide (PEI) based separator (IAPEI-4) with excellent heat resistance and electrochemical properties was prepared. Briefly, by grafting amino group (–NH 2 ) onto the surface of SiO 2 , highly dispersed amino-functionalized SiO 2 (A-SiO 2 ) were synthesized as fillers to blend PEI matrix. Based on physical characterizations of the representative IAPEI-4 separator, abundant micropores and mesopores exist in the separator, and A-SiO 2 nanoparticles are uniformly distributed in the PEI matrix. The ameliorated Li + transport channels and the uniform distribution of A-SiO 2 nanoparticles endow IAPEI-4 separator with higher ionic conductivity (1.60 mS cm −1 ) and Li + transfer number (0.63). Besides, the IAPEI-4 separator exhibits good electrochemical stability and excellent thermal stability (no shrinkage at 200°C). The Li-S cells with the IAPEI separator also show greatly enhanced electrochemical performances. After 100 cycles, its specific discharge capacity can reach 695.4 mAh g −1 at 0.2 C and its capacity retention rate is 84.8%. This simple and effective separator modification method can provide a general strategy to achieve high-performance Li-S batteries.

Anodized Aluminum Oxide Separators with Aligned Channels for High-Performance Li–S Batteries

Bo Wang,Wei Guo,Yongzhu Fu

Lithium–sulfur (Li–S) batteries are promising to enable high-energy-density storage systems; however, their commercialization is hampered by several technical challenges such as polysulfide shuttle and safety issues related to the lithium metal anode. Herein, we use anodized aluminum oxide (AAO) membranes as separators in Li–S batteries for the first time. AAO membranes are rigid and nonflammable, which is helpful for improving battery safety. The aligned and uniform channels within AAO membranes provide fast pathways for lithium ion transport, leading to low areal specific resistance due to the electroosmotic flow of lithium ions in nanoscaled channels. In addition, the AAO separator leads to low overpotential during lithium deposition/stripping in lithium symmetric cells. The Li–S cells with AAO separators show better cycling performance than those with Celgard ones, in particular, at high C rates. At the 2 C rate, the cell shows a battery performance of 480 cycles with a capacity degradation rate of 0.105%, which is much better than that when the Celgard separator is used. This work demonstrates that AAO membranes are promising separators with unique properties for improving the performance of Li–S batteries.

Aggregation-induced Emission-active Hyperbranched Poly(tetrahydropyrimidine) s Synthesized from Multicomponent Tandem Polymerization

Huang Yuzhang,Chen Ping,Wei Bo,Hu Rongrong,Tang Ben Zhong

Hyperbranched polymer with highly branched three-dimensional topological structure, a large number of end groups, and multifaceted functionalities have gained much attention, while polymers with aggregation-induced emission (AIE) properties become a group of popular luminescent materials recently. The design and synthesis of AIE-active hyperbranched polymers, which combine the advantages of these two types of materials, are attractive but challenging. In this work, four hyperbranched poly(tetrahydropyrimidine)s were synthesized from the metal-free room temperature multicomponent tandem polymerization of diester group-activated internal alkyne, polyfunctional aromatic amines, and formaldehyde in methanol under the catalysis of acetic acid. Through different monomer combination and controlling the monomer loading order, hyperbranched polymers with various topological structures as well as sequences of different functional groups in the polymer backbone were obtained with high molecular weights (up to 3.0 × 10 4 g/mol) in high yields (up to 98%). The hyperbranched poly(tetrahydropyrimidine) emitted faintly in solution, while its luminescence was notably enhanced in the aggregated state, suggesting its typical aggregation-induced emission property. It is anticipated that the multicomponent polymerization may provide a synthetic platform for the construction of hyperbranched polyheterocycles with diverse structures and functionalities.

Preparation and Application of a Novel S-Scheme Nanoheterojunction Photocatalyst (LaNi0.6Fe0.4O3/g-C3N4)

Kexin Zhang,Rui Wang,Xin Zhong,Fubin Jiang

Rapid recombination of photogenerated electrons and holes affects the performance of a semiconductor device and limits the efficiency of photocatalytic water splitting for hydrogen production. The use of an S-scheme nanoscale heterojunction catalyst for the separation of photogenerated charge carriers is a feasible approach to achieve high-efficiency photocatalytic hydrogen evolution. Therefore, we synthesized a three-dimensional S-scheme nanoscale heterojunction catalyst (LaNi0.6Fe0.4O3/g-C3N4) and investigated its activity in photocatalytic water splitting. An analysis of the band structure (XPS, UPS, and Mott–Schottky) indicated effective interfacial charge transfer in an S-scheme nanoscale heterojunction composed of two n-type semiconductors. X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) spectroscopy confirmed that the light-induced charge transfer followed the S-scheme mechanism. Based on the capture test (EPR) of •OH free radicals, it can be seen that the enhanced activity is attributed to the S-scheme carrier migration mechanism in heterojunction, which promotes the rapid adsorption of H+ by the abundant amino sites in g-C3N4, thus effectively generating H2. The 2D/2D LaNi0.6Fe0.4O3/g-C3N4 heterojunction has a good interface and produces a built-in electric field, improving the separation of e– and h+ while increasing the oxygen vacancy. The synergistic effect of the heterostructure and oxygen vacancy makes the photocatalyst significantly better than LaNi0.6Fe0.4O3 and g-C3N4 in visible light. The hydrogen evolution rate of the composite catalyst (LaNi0.6Fe0.4O3/g-C3N4-70 wt %) was 34.50 mmol·h–1·g–1, which was 40.6 times and 9.2 times higher than that of the catalysts (LaNiO3 and g-C3N4), respectively. After 25 h of cyclic testing, the catalyst (LaNi0.6Fe0.4O3/g-C3N4-70 wt %) composite material still exhibited excellent hydrogen evolution performance and photostability. It was confirmed that the synergistic effect between abundant active sites, enriched oxygen vacancies, and 2D/2D heterojunctions improved the photoinduced carrier separation and the light absorption efficiency of visible light. This study opens up new possibilities for the logical design of efficient photodecomposition using 2D/2D heterojunctions combined with oxygen vacancies.

High-Energy-Density Solid-Electrolyte-Based Liquid Li-S and Li-Se Batteries

Yang Jin,Kai Liu,Jialiang Lang,Xin Jiang,Zhikun Zheng,Qinghe Su,Zeya Huang,Yuanzheng Long,Chang-an Wang,Hui Wu,Yi Cui

Lithium-sulfur (Li-S) and Lithium-selenium (Li-Se) batteries are considered as promising candidates for next-generation battery technologies, as they have high energy density and low cost. However, due to the use of a solid Li-metal anode and a liquid organic electrolyte, the current Li-S and Li-Se batteries face several issues in terms of Coulombic efficiency and cycling stability, which seriously impeded their development. Here, we report solid-electrolyte-based liquid Li-S and Li-Se (SELL-S and SELL-Se in short) batteries. The batteries use a Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) ceramic tube as electrolyte and work at temperatures higher than the melting point of Li; thus, polysulfide or polyselenide shuttle effects and Li dendrite growth are effectively prevented, and high energy density, together with high stability, fast charge/discharge capability, high Coulombic efficiency, and high energy efficiency, can be achieved. The SELL-S and SELL-Se batteries provide broader platforms for constructing high-energy, high-power, long-lifetime, and low-cost energy storage.

Polypyrrole-Reinforced N,S-Doping Graphene Foam for Efficient Solar Purification of Wastewater

Lifen Su,Yuying Ning,Ziqiang Ma,Yuhao Zhang,Chuanlei Liu,Youli Zhang,Lei Miao,Jianhua Zhou,Bin Wu,Jiasheng Qian

Solar vapor generation is a sustainable and cost-effective approach to addressing the issue of water shortage. However, the challenges of solar steam generation still exist for achieving a high evaporation efficiency combined with long-term stability in the wastewater containing heavy metal ions and wide degrees of acidity and alkalinity (pH = 1–14). Herein, polypyrrole (PPy) loading on the N,S-doped graphene oxide (N,S-GO) foam is used for high-efficiency solar evaporation of treating wastewater. With the advantages of excellent broadband solar absorption ( >97%), extremely low emissivity (0.70), and outstanding hydrophilicity, the N,S-GO/PPy foam achieves a high evaporation efficiency of 90.5% under 1 sun illumination. More notably, the N,S-GO/PPy foam has strong adsorption of heavy metal ions (Fe 3+ , Cu 2+ , and Cr 6+ ) for treating wastewater synchronously evaporates at higher efficiencies of 94.7–98.4%. Interestingly, the high-toxicity Cr 6+ can be reduced to low-toxicity Cr 3+ effectively by the synergistic effect of N,S-GO and PPy. In addition, the N,S-GO foam shows a better long-term resistance of acidity and alkalinity for 45 days. A new insight is offered into high-efficiency solar evaporation for treating wastewater and water purification.

Atmospheric Modified Thiol-Based Solution Deposition for Cu2ZnSn(S,Se)4 Absorber Layer

Chen Ruilan,Cui Guonan,Yang Yanchun,Li Yuemin,Alata H.,Tian Xiao,Tegus O.

Abandoning the traditional deposition of as-prepared Cu 2 ZnSnS 4 (CZTS) thin films in a glove box, a modified thiol-based solution system suitable for deposition in air is described to further reduce device production costs. In this modified approach, metal salts and thiourea are used as the starting materials and are dissolved in a mixed solution of thioglycolic acid and 2-methoxyethanol, forming a homogeneous precursor solution. The as-deposited CZTS thin films are obtained by spin-coating the precursor solution in air, followed by the selenization process to form large-grained Cu 2 ZnSn(S,Se) 4 thin films. Combining the microstructural results with compositional analyses, the optimal selenization conditions for the Cu 2 ZnSn(S,Se) 4 absorber layer were found to be 540°C and 10 min.

Effect of polydopamine coating on improving photostability of poly(1,3,4-oxadiazole)s fiber

Yang Xiao,Duan Lian,Cheng Xinjian,Ran Xiaoqi

Effect of polydopamine coating on improving photostability of poly(1,3,4-oxadiazole)s (POD) fiber was studied in detail. Due to strong adhesion ability of polydopamine, the POD fiber could be coated easily by dopamine in Tris–HCl ( pH  = 8.5) solution at room temperature with exist of oxygen. The polydopamine coating was characterized by SEM, XPS and ATR-FTIR. It was proved by UV-spectra analysis that the polydopamine coating had a strong absorbance in ultraviolet wavelength and was very stable to ultraviolet. Additionally, it was found by pyrogallol autoxidation method that the polydopamine could efficiently capture superoxide anion radical, which was an important factor that resulted in photodegradation of POD fiber, due to its catechol structure. These two findings implied that polydopamine coating was a potential photoprotection agent. Finally, compared to POD fiber, the tensile test of POD fiber coated by polydopamine further proved that the polydopamine did improve the photostability of POD fiber. And the FTIR analysis of POD coated by polydopamine also confirmed that there was almost no macromolecular change after UV exposure.

Fiber SPR Sensor Based on S-Taper Sensitivity Enhancement for Nickel Ion Detection

Yong Wei,Jing Cheng,Yabin Shao,Chunlan Liu,Puxi Ren,Yixiong Tang,Ziqiang Zhang,Mingjun Cai,Zhihai Liu