SOUTH AFRICAN JOURNAL OF BOTANY
·
2018
·
IF 1.442
J.J. Nair,J. Van Staden
Cancer is a leading cause of death worldwide. This, in spite of the tremendous gains made in cancer chemotherapies over the past several decades. The identification and development of new targets with greater structural diversities and better potencies are at the forefront of drug discovery endeavors across disciplines. Plants have afforded a significant number of successful anticancer drugs, several of which manifest their activities by inducing apoptosis (or programmed cell death) in cancer cells. The Amaryllidaceae alkaloids have similarly distinguished themselves as potent antiproliferative agents, some at the nanomolar level, with selective apoptosis inducing effects demonstrated in a wide variety of cancer cells. The proteolytic enzymes caspases are the key effectors of the apoptotic pathways, the main function of which is, in turn, the activation of caspases. Once activated caspases set in motion an intricately choreographed cascade of events leading to eventual cell death and phagocytosis. The lycorane and crinane group of alkaloids were amongst the first of the Amaryllidaceae for which apoptosis and attendant caspase inducing effects were discovered. These have been central in ongoing efforts to unravel the mechanistic basis to the cytotoxicity of these alkaloids. This review focuses on the various caspases which have been shown to be integral in apoptosis signaling pathways mediated by lycorane and crinane alkaloids.
研究领域:
药理学
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植物化学
·
肿瘤学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-11
·
IF 17.694
Yu Dejian,Cao Fei,Liao Jinfeng,Wang Bingzhe,Su Chenliang,Xing Guichuan
Mixed-dimensional 2D/3D halide perovskite solar cells promise high stability but practically deliver poor power conversion efficiency, and the 2D HP component has been held as the culprit because its intrinsic downsides (ill charge conductivity, wider bandgap, and strong exciton binding) were intuitively deemed to hinder carrier transport. Herein, we show that the 2D HP fragments, in fact, allow free migration of carriers in darkness but only block the carrier transport under illumination. While surely limiting the photovoltaic performance, such photoinduced carrier blocking effect is unexplainable by the traditional understanding above but is found to stem from the trap-filling-enhanced built-in potential of the 2D/3D HP interface. By parsing the depth-profile nanoscopic phase arrangement of the mixed-dimensional 2D/3D HP film for solar cells and revealing a photoinduced potential barrier up to several hundred meV, we further elucidate how the photoinduced carrier blocking mechanism jeopardizes the short-circuit current and fill factor.
研究领域:
材料科学
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光伏技术
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Xiaobin Zhao,Quansheng Wu,Xufeng Zhou,Shanshan Ye,Jianyan Ding
The realization of Eu 3+ reduction and its reduction mechanism have become focal points in the field of WLED phosphor research. In this study, the reduction of Eu 3+ was successfully achieved through cationic substitution strategy by replacing Zr 4+ with Hf 4+ in Na 2 ZrSiO 5 :Eu 3+ . The effects of substituting Hf 4+ for Zr 4+ on the phase, crystal structure, and luminescence properties of Na 2 Zr 1- x Hf x SiO 5 :Eu 0.03 (0 ≤ x ≤ 1) were thoroughly investigated based on Rietveld refinement , spectral data, DFT calculation and electronegativity of ions. Comprehensive consideration was given to the effect of site size change and site reducibility on Eu 3+ reduction. The results demonstrate that the reduction of Eu 3+ in Na 2 Zr 1- x Hf x SiO 5 :Eu 0.03 is attributed to the alteration in inducible effect caused by cationic substitution and the enhancement in site reducibility rather than changes in site size. Therefore, the cationic substitution strategy based on induction effect presents a novel approach for achieving Eu 3+ reduction and offers a new insight into developing and modifying Eu 2+ -activated phosphors.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yulin Xing,Jiangang Ku,Weng Fu,Lianzhou Wang,Huihuang Chen
Oxygen evolution reaction (OER) remains the bottleneck of many energy transformation and storage technologies due to the sluggish kinetics. Transition-metal (TM) hydroxide nanosheets with high-valent TM ions possess high intrinsic catalytic activity toward OER. Herein, by taking advantage of the inductive effect, this work presents a facile and universal strategy to fabricate atomic iridium (Ir) incorporated TM hydroxide nanosheets as highly active OER electrocatalysts . As a representative, the fabricated Ir-Ni(OH) 2 (4 wt% Ir) exhibits remarkable OER performance with a low overpotential (235 mV at 10 mA cm −2 ), a small Tafel slope (58.4 mV dec −1 ), and excellent durability (60 h) in alkaline solution, significantly outperforming the benchmark IrO 2 and Ni(OH) 2 . Mechanism studies unveil that the inductive effect between Ni and Ir endows Ni(OH) 2 with high-valent Ni species, which facilitate the adsorption of nucleophilic intermediates and boost the OER activity and long-term stability of Ir-Ni(OH) 2 . More importantly, the reported strategy could be extended to synthesize other monometallic/bimetallic TM hydroxide nanosheets (Co, CoMn) as highly efficient OER electrocatalysts. This work should pave a universal and promising avenue to rationally design and controllably synthesize efficient yet robust OER electrocatalysts in energy-related fields.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
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2022
·Vol. 12
·期 9
·1043
·
IF 4.501
Shuang Tang,Yang-Sen Xu,Wei-De Zhang
Molecular skeleton modification has become a recognized method that can effectively improve the photocatalytic performance of g-C3N4because it not only effectively promotes charge separation, but also tunes the conjugated system of g-C3N4to make it more conducive to photocatalytic reaction. Herein, thiophene-amide embedded g-C3N4(TA-CN-x) was successfully prepared by simple one-step thermal polycondensation using urea as a precursor and ethyl-2-amino-4-phenylthiophene-3-carboxylate (EAPC) as an additive. After embedding with thiophene-amide, the induction and delocalization effects are formed in TA-CN-x, which significantly improves the migration efficiency of photogenerated charge carriers. Meanwhile, the conjugate structure is changed due to structural modification, resulting in significant enhancement of visible light absorption compared to the pure g-C3N4(CN). Specifically, the optimized photocatalytic H2evolution rate of TA-CN-2 reaches 245.4 μmol·h−1, which is 8.4 times that of CN (with Pt nanoparticles as a co-catalyst), and the apparent quantum efficiency (AQY) at 450 nm is 13.6%. This work opens up a new modification process for fully tapping the photocatalytic hydrogen absorption potential of g-C3N4-based materials.Keywords:photocatalysts;g-C3N4;thiophene-amide;embedding;induction effect;delocalization effect;hydrogen evolution
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CURRENT DRUG METABOLISM
·
2022
·Vol. 23
·期 13
·1054-1066
·
IF 3.408
Chai Yuan-Yuan,Xu Yun-Xia,Xia Zi-Yin,Li An-Qin,Huang Xin,Zhang Lu-Yong,Jiang Zhen-Zhou
Background: The use of herbal medicines has tremendously increased over the past few decades. Case reports and controlled clinical investigations of herbal-drug interactions have been reported. Since Cytochrome P450 (CYP) enzymes play an important role in drug interactions. The evaluation
of the influence of herbal medicines on the activities of CYPs is beneficial to promote scientific and rational clinical use of herbal medicines. Objective: Herein, we aimed to develop and validate a method to simultaneously quantify seven CYP cocktail probe drugs consisting of phenacetin
(PNC), bupropion (BPP), losartan potassium (LK), omeprazole (OMP), dextromethorphan (DM), chlorzoxazone (CZZ) and midazolam (MDZ) and their respective metabolites in a single acquisition run and use this method to evaluate the influence of Zhuanggu Guanjie Pill (ZGGJP) on seven CYPs.
Methods: A cost-effective and simple UHPLC-(±)ESI-MS/MS method for simultaneous determination of seven probe drugs and metabolites in rat plasma was developed and validated. Male and female rats were randomly divided into three groups and treated with 1.2 g/kg/d ZGGJP, 5 g/kg/d ZGGJP
and 0.5% CMC-Na for 14 consecutive days. After 24 h of the last administration, all rats were administrated orally with probe drugs. The influence of ZGGJP on the CYPs was carried out by comparing the metabolic ratio (Cmax, AUC0-t) of metabolites/probe
drugs in rats. Results: The calibration curves were linear, with correlation coefficient > 0.99 for seven probe drugs and their corresponding metabolites. Intra- and inter-day precisions were not greater than 15% RSD and the accuracies were within ± 15% of nominal concentrations.
The ZGGJP showed significant inductive effect on CYP1A2, CYP2B6, CYP2C9 and CYP3A in male and female rats. Conclusion: ZGGJP had inductive effects on CYP1A2, CYP2B6, CYP2C9 and CYP3A in male and female rats.
研究领域:
药理学
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临床药学
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中药学
✓ 已验证
DOI
PubMed
高影响因子
Frontiers of Environmental Science & Engineering
·
2022
·Vol. 17
·期 5
·1-13
·
IF 6.048
Wang Zhe,Zhang Wenjuan,Wang Zhiwei,Chang Jing
For aromatic monomer compounds (AMCs), ozonation outcomes were usually predicted by the substituents of the benzene ring based on the electron inductive effect. However, the predicted results were occasionally unreliable for complex substituents, and other factors caused concern. In this study, p -chloronitrobenzene ( p -CNB) and ibuprofen (IBP) were selected for ozonation. According to the electron inductive theory, p -CNB should be less oxidizable, but the opposite was true. The higher rates of p -CNB were due to various sources of assistance. First, the hydroxyl radical (•OH) contributed 90 % to p -CNB removal at pH 7.0, while its contribution to IBP removal was 50 %. Other contributions came from molecular O 3 oxidation. Second, p -CNB achieved 40 % of the total organic carbon (TOC) removal and fewer by-product types and quantities, when compared to the results for IBP. Third, the oxidation of p -CNB started with hydroxyl substitution reactions on the benzene ring; then, the ring opened. However, IBP was initially oxidized mainly on the butane branched chain, with a chain-shortening process occurring before the ring opened. Finally, the degradation pathway of p -CNB was single and consumed fewer oxidants. However, both branches of IBP were attacked simultaneously, and three degradation pathways that relied on more oxidants were proposed. All of these factors were determinants of the rapid removal of p -CNB.
研究领域:
环境科学
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化学工程
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2022
·
IF 3.428
Qingmei Zhang,Songjie He,Kaiwen Zheng,Lupeng Zhang,Lihua Lin,Fenghua Chen,Xiujuan Du,Bing Li
A growing interest has emerged in carbon dot (CDs) fluorescent probes, as they are non-destructive, non-contact, sensitive, fast, and low-cost. However, the low fluorescence quantum yield (QY) and the uncertainty of fluorescence quenching mechanism are the main bottlenecks restricting its application. Here, we used mustard seeds as carbon source, CDs were synthesized by a simple hydrothermal method without further surface treatment with the QY reached a value as high as 17.92 % in 468 nm excitation energy. As a label-free fluorescent probe, CDs can be used to sense Fe 3+ ions in environmental water and human oral keratinocytes (Hok) cells, with a detection limit of 0.51 μM and the linear range of 0–75 μM. Moreover, we have conducted an in-depth study on the mechanism of fluorescence quenching of CDs caused by Fe 3+ ions. Our study provides powerful evidences that the mechanism of fluorescence quenching to Fe 3+ ions is a synergistic effect of static quenching (SQ) and aggregation-induced effect (AIE), which accompanied by forming a non-fluorescent ground state complex between CDs and Fe 3+ ions. This work promises to provide new ideas for the most appropriate detection strategy and design the best performing sensor, allowing their effective application in the sensing field.
研究领域:
材料科学
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环境科学
·
生物医学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2022
·Vol. 9
·期 24
·6448-6456
·
IF 7.779
Shan Zhang,Ao Gong,Xinxiang Yang,Pei Han,Ningning Sun,Yong Li,Liwen Zhang,Xihong Hao
The use of ferroelectric materials is believed to be a viable way to construct self-powered photodetectors based on the ferroelectric photovoltaic effect. However, the low photocurrent density of ferroelectric materials is a serious drawback that restricts their photo-detection applications. Herein, ultrahigh photo-detection performances are achieved in hexagonal YbMnO3-based self-powered photodetectors by optimizing the macroscopic polarization. The responsivity (R) and detectivity (D*) can reach 0.18/0.15 A W−1 and 6.73 × 1011/5.76 × 1011 Jones under monochromatic light with a wavelength of 365/700 nm when the YbMnO3 thin film [YbMnO3(1040)] is sintered at 1040 °C. These excellent photo-detection performances are attributed to the high short-circuit current density which reaches 10.9 mA cm−2 under 1 sun illumination. A systematic structure and photo-electric characteristic analysis suggests that the formation of a strong domain and the distortion of the crystal structure lead to an enhanced macroscopic polarization in YbMnO3(1040) without changing the bandgap. The enhanced polarization causes a ripple positive effect, which increases the driving force of photo-generated carrier separation and restrains recombination, leading to a high dissociation efficiency. This work demonstrates that the ferroelectric YbMnO3 thin film has great potential in the photo-detection field.
研究领域:
材料科学
·
光电子学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
W.Q. Yang,Y.X. Hua,Q.B. Zhang,H. Lei,C.Y. Xu
The development of earth-abundant, low-cost, highly active, and durable bifunctional catalysts competent for efficient electrochemical water-splitting is intensively demanding and of vital importance to realize high-purity hydrogen production . Herein, we report that 3D quasi-amorphous pompon-like Co-O and Co-Se hybrid films grown on copper foil (Co-O@Co-Se/Cu) can be electrochemically synthesized from a choline chloride and urea mixed deep eutectic solvent , denoted as Reline, via a facile one-step electrochemical deposition approach. Benefiting from the induction effect of Se, the obtained Co-O@Co-Se/Cu hybrid electrode exhibits strongly enhanced catalytic activity. The optimal Co-O@Co-Se/Cu sample shows good activity and excellent durability for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in an alkaline solution with low overpotentials of 85 mV for HER and 340 mV for OER, respectively to reach a catalytic current of 10 mA cm −2 . The Co-Se component within the hybrid films is gradually converted into Co-O species during the course of the OER, which are responsible for the good OER performance. In addition, when performed as bifunctional catalysts in a two-electrode configured electrolyzer, the Co-O@Co-Se/Cu couple displays a water-splitting current of 10 mA cm -2 at 1.65 V with reasonable stability for long-term electrolysis over 100 h. This simple one-step electrochemical synthesis route operated in the Reline-based deep eutectic solvent is demonstrated as an efficient strategy to fabricate active non-noble-free electrocatalysts toward overall water splitting applications.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
DYES AND PIGMENTS
·
2023
·
IF 4.5
He Zhang,Lucheng Li,Jun Chen,Jing Wang,Yang Liu,Huijie Zhang,Qiang Wang,Shuangqing Wang,Guoqiang Yang
Phthalocyanine compounds are a class of macrocyclic conjugated structures with 18 π-electrons. And have better photophysical properties. However, the π-π electron interactions lead to aggregation between phthalocyanine molecules, which affects optical limiting properties. In this work, the conjugated organic small molecule antiphenylenediamine ( PDA ) is grafted onto the phthalocyanine conjugate system through the azo condensation reaction , and the covalent organic framework polymer ( PDA-InPc ) was obtained. Then it is doped into the polymethyl methylmethacrylate ( PMMA ) matrix to produce a phthalocyanine solid device with different thickness ( PMMA-PDA-InPc ). The aggregation-free phthalocyanine covalent organic frameworks avoids intramolecular aggregation of the phthalocyanine units, and dispersing it in PMMA solid devices can also reduce intermolecular π-π stacking. As a result, the fluorescence lifetime of PMMA-PDA-InPc is τ 1 = 0.52 ns (A 1 = 95.71%) and τ 2 = 11.5 ns (A 2 = 4.29%), indicating that the phthalocyanine conjugated unit exists mainly as monomers (95.71%), while the proportion as aggregates is very small (4.29%). At the input laser energy of 9 μJ, the nonlinear absorption coefficient of PMMA-PDA-InPc device is (2.2 × 10 −9 m/W), which is significantly better than PMMA-InPc device (1.0 × 10 −9 m/W), indicating that PMMA-PDA-InPc has improved nonlinear absorption and reverse saturation absorption. This design idea of non-aggregated phthalocyanine covalent organic frameworks and its solid device expands a new idea for the development of useable phthalocyanine optical limiters .
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Nano-Micro Letters
·
2025
·Vol. 17
·期 1
·1-19
·
IF 36.3
Hu Haiman,Li Jiajia,Lin Fei,Huang Jiaqi,Zheng Huaiyang,Zhang Haitao,Ji Xiaoyan
Quasi-solid-state composite electrolytes (QSCEs) show promise for high-performance solid-state batteries, while they still struggle with interfacial stability and cycling performance. Herein, a F-grafted QSCE (F-QSCE) was developed via copolymerizing the F monomers and ionic liquid monomers. The F-QSCE demonstrates better overall performance, such as high ionic conductivity of 1.21 mS cm –1 at 25 °C, wide electrochemical windows of 5.20 V, and stable cycling stability for Li//Li symmetric cells over 4000 h. This is attributed to the significant electronegativity difference between C and F in the fluorinated chain (‒CF 2 ‒CF‒CF 3 ), which causes the electron cloud to shift toward the F atom, surrounding it with a negative charge and producing the inductive effect. Furthermore, the interactions between Li + and F, TFSI ‒ , and C are enhanced, reducing ion pair aggregation (Li + ‒TFSI ‒ ‒Li + ) and promoting Li + transport. Besides, ‒CF 2 ‒CF‒CF 3 decomposes to form LiF preferentially over TFSI – , resulting in better interfacial stability for F-QSCE. This work provides a pathway to enable the development of high-performance Li metal batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）