MACROMOLECULAR BIOSCIENCE
·
2015
·Vol. 15
·期 6
·829-838
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IF 3.851
Haiyang Yu,Zhaohui Tang,Dawei Zhang,Wantong Song,Taicheng Duan,Jingkai Gu,Xuesi Chen
A novel random copolypeptide of ornithine, arginine, glycine, and aspartic acid [Poly(ornithine-co-arginine-co-glycine-co-aspartic acid), Poly(O,R,G,D)] has been prepared through ring-opening polymerization of N -δ-carbobenzoxy-l-ornithine N -carboxyanhydride [Orn(Cbz)-NCA)], l-glycine N -carboxyanhydride (Gly-NCA) and β-benzyl l-aspartate N -carboxyanhydride [Asp(Bn)-NCA], following by subsequent deprotection and guanidization. The structure of Poly(O,R,G,D) was confirmed by nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). Low cytotoxicity of Poly(O,R,G,D) was confirmed from MTT assay. The Poly(O,R,G,D) contain some internal sequences of RXXR ( X = O, R, G, or D) that could be proteolytically cleaved to expose the cryptic CendR element and bind to Neuropilin-1. This would lead to vascular and tissue permeabilization. Therefore trypsin-cleaved Poly(O,R,G,D) increase the vascular leakage of Evans blue from dermal microvessels at the injection site in vivo skin permeability assay. The intratumoral injection of the Poly(O,R,G,D) significantly enhanced the concentration of cisplatin-loaded nanoparticles in MCF-7 solid tumors. These results show that Poly(O,R,G,D) could increase the vascular leakage and tissue penetration of nanoparticles in a solid tumor and can be used as a potential polymeric tumor-penetrating agent.
研究领域:
生物化学
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肿瘤学
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药剂学
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产品关联
DOI
PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
·
2023
·
IF 5.4
Qihan Meng,Lei Wang,Fei Chen,Qingfei Hao,Xudong Sun
Ramsdellite-type Li 2 Ti 3 O 7 (R-Li 2 Ti 3 O 7 ) hollow microspheres were successfully prepared for the first time by the flame melting method. The hollow microspheres are 50-120 μm in diameter and about 10 μm in shell thickness. The spherical morphology allows for a high tapping density (1.25 g cm −3 ), and the hollow structure increases the specific surface area which is beneficial to the electrochemical properties. Thus, the prepared R-Li 2 Ti 3 O 7 shows excellent electrochemical properties even at high tapping densities. A specific capacity of 212.1 mAh g −1 can be obtained at a rate of 0.1 C, and the capacity retention after 500 cycles at 1 C is 94.6% with a specific capacity of 150.3 mAh g −1 . The flame melting method is effective for the preparation of Li 2 Ti 3 O 7 hollow spheres which showed good performance as the anode for lithium-ion batteries.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
STEROIDS
·
2013
·
IF 2.803
Shu-Xiao Feng,Ya-Dong Zhang
One-pot synthesis of an 18-norsteroid compound, 13( R ),14( R )-epoxy-17β-methyl-20( S )-hydroxyl-18-nor-pregna-4-en-3-one has been achieved with peracetic acid/acetic acid under a mild condition, via a proved tandem epoxidation-rearrangement-epoxidation sequence. Its structure was designated on the basis of NMR and X-ray crystallography data.
研究领域:
有机化学
·
药物化学
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DOI
PubMed
高影响因子
NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY
·
2024
·
IF 3.1
Wei Liangli,Yuan Yuqi,Yang Ziteng,Li Yuqing,Wang Tingting,Hu Shenglin,Cai Biao,Wang Guangyun
The neuroprotective function of ginsenoside Rb1 (GRb1) in cerebral ischemia–reperfusion (I/R) was lately emphasized. However, whether GRb1 plays a regulatory role on endoplasmic reticulum (ER) stress-associated pathway in cerebral I/R damage is still unclear. The aim of this study is to explore the function of GRb1 in cerebral ischemia-induced ER stress and the underlying mechanism related to IRE1/TRAF2/JNK pathway. Longa method, cerebral infarct volume, and HE staining were used to evaluate the efficacy of GRb1 in mice with a mouse model of middle cerebral artery occlusion reperfusion (MCAO/R). We also investigated the effect and mechanism of GRb1 against ischemic stroke using in vitro oxygen–glucose deprivation reperfusion (OGD/R) model. We found that GRb1 could improve neurological scores, infarct volume, and histological injury in ischemic mice. Ischemic attack also activated neuronal apoptosis and ER stress, and this effect was attenuated by GRb1. In addition, GRb1 significantly reduced I/R-induced IRE1-TRAF2 interaction, IRE1, and JNK phosphorylation. The present study also confirmed that GRb1 significantly improved OGD/R-induced PC12 cells injury. GRb1 could decrease ER stress in OGD/R-injured PC12 cells, which was reflected by the decreased expression of GRP78 and CHOP. The ER stress inducer tunicamycin partially prevented the effects of GRb1 on cell viability, ER stress, and apoptosis after OGD/R, whereas the ER stress inhibitor 4-PBA exerted the opposite effect. Moreover, GRb1 markedly decreased IRE1-TRAF2 interaction, IRE1, and JNK phosphorylation in the presence of OGD/R insult. Furthermore, JNK inhibitor SP600125 and IRE1 inhibitor DBSA pretreatment further promoted the inhibition of GRb1 on ER stress induction and cell damage induced by OGD/R. Molecular docking further elucidated that the mechanism by which GRb1 improves cerebral ischemia maybe related to its direct binding to the kinase domain of IRE1, which in turn inhibited the phosphorylation of IRE1. Collectively, these results demonstrated that GRb1 reduced ischemic stroke-induced apoptosis through the ER stress-associated IRE1/TRAF2/JNK pathway and GRb1 has the potential as a protective drug for the treatment of cerebral ischemia.
研究领域:
神经科学
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药理学
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细胞生物学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2024
·
IF 5.5
Menghang Sun,Xinyu Zhou,Lili Li,Bo Wen,Yunzi Miao,Xiaofeng Liu,Wei Yan,Guorui Yang,Shujiang Ding
Recycling spent cathode materials is crucial for sustainably developing lithium-ion battery technology. To achieve the high-value utilization of spent LiFePO 4 (LFP) cathodes, this paper proposes a method for preparing MIL-100(Fe) based on solid waste residues from spent LFP cathodes. R-FeS 2 @C derived from MIL-100(Fe) can serve as an anode material for potassium-ion batteries featuring a porous structure. Electrochemical tests demonstrate that the R-FeS 2 @C exhibits more stable cycling performance compared with the FeS 2 @C derived from the traditional MIL-100(Fe), reaching 525 mAh g −1 after 100 cycles at a current density of 100 mA g −1 . Impressively, R-FeS 2 @C also showcases excellent rate performance (343 mAh g −1 specific capacity at 5 A g −1 ). Furthermore, full cells assembled with PI@rGO cathodes also exhibit excellent rate performance and stable cycling performance. The porous structure of R-FeS 2 @C provides numerous voids to accommodate volume changes and introduces sufficient channels for electrolyte penetration. The higher carbon content enhances the electrical conductivity improving the kinetics of the K + migration reaction. These researches can provide guidance for the recycling of spent lithium-ion batteries and the design of sulfide electrodes for PIBs.
研究领域:
材料科学
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能源存储技术
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环境工程
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产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
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2022
·
IF 5.304
Fei Cheng,Taiming Zhang,Chunhua Yang,Hongqiu Zhu,Yonggang Li,Tao Sun,Can Zhou
To determine the total iron concentration in aqueous solutions containing complexing matrix, a direct and rapid ultraviolet–visible spectroscopy determination method was developed using the Nitroso R salt as a chromogenic reagent. In the presence of NaI and CTMAB, the experiment shows that Nitroso R salt-Fe complex can produce a significantly sensitive and selective absorbance peak at 710 nm with no notable time for sensing. The experimental factors that affect the procedure such as temperature, acidity and dosages of various reagents were analyzed and optimized. Under the optimized experimental conditions, the limit of detection and limit of quantification of the method was 4.5 × 10 −8 and 1.5 × 10 −7 mol/L. The calibration curve was obtained in a wide linear range of 1.5 × 10 −7 -6.4 × 10 −5 mol/L with good linearity (R 2 = 0.9989). The method was free of any interference with common ions and can determine the iron content in the complex matrix of aqueous samples. The methodology was further validated by the certified reference water samples used for environmental monitoring and agreed with the ICP-OES spectrophotometry results. Compared with the conventional method, the relative standard deviations of the spike test in various actual samples were in the range of 0.31%-2.9% ( n = 5). Good recoveries between 96.4% and 107% were obtained. The proposed method provides great promise for application in-field analysis of iron content in various environmental samples and hydrometallurgical solutions owing to its high sensitivity, low cost, good reproducibility, and no need for any complex pretreatment.
研究领域:
分析化学
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环境科学
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冶金工程
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 6
·2258-2272
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IF 3.5
Luo Hanqiong,Hu Quanli,Yue Bin,Du Suxuan
Rare earth orthocobaltates nanofibers (PrCoO 3 , EuCoO 3 , and GdCoO 3 ) were prepared by a simple electrospinning method coupled with calcination. The PrCoO 3 , EuCoO 3 , and GdCoO 3 nanofibers have orthorhombic perovskite structure. The fabricated electrodes presented the typical pseudocapacitive characteristics, which originated from the reversible redox reactions of Co 2+ /Co 3+ and Fe(CN) 6 3− /Fe(CN) 6 4− . At 1 A g −1 , the specific capacitances of the PrCoO 3 , EuCoO 3 , and GdCoO 3 nanofibers were 119, 133, and 196 F g −1 , respectively. The electrochemical characteristics of the PrCoO 3 , EuCoO 3 , and GdCoO 3 nanofibers exhibited favorable specific capacitance, good long-term cycling stability, and high coulombic efficiency, proving the possible application into energy storage devices. PrCoO 3 and EuCoO 3 nanofibers exhibited a magnetic state transition from paramagnetic to antiferromagnetic state. GdCoO 3 nanofibers showed a paramagnetic ordering at high temperature. The cooperation of the R 3+ ions and the Co 2+ ions contributed to the magnetism of rare earth orthocobaltates nanofibers. The antiferromagnetic behaviors of the fabricated samples confirm the potential application into spin-electronic devices.
研究领域:
材料科学
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电化学
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纳米技术
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固态物理
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能量存储
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DOI
高影响因子
JOURNAL OF INFORMATION SCIENCE
·
2018
·
IF 1.939
Esam Al-Nsour,Azzam Sleit,Mohammad Alshraideh
Spatial data indexing methods are of extreme importance as they massively build up as a result of the explosive growth in capturing data with spatial features. No matter how much the data size is, eventually it will reside on disk pages. Disk pages have to be properly indexed to preserve spatial properties of objects, optimise disk space usage and improve objects’ retrieval performance. One of the most popular spatial data indexes is the R-tree which is a height balanced tree data structure, where leaf nodes resemble disk pages and contain pointers to objects’ locations. A single tree node can host up to a maximum number of objects, where any more insertion makes it an overflown node and it has to be split. Better splits lead to better index performance and more utilisation of disk space. In this work, we introduce a new way of finding the most proper split for an overflown node in the R-tree index. The proposed work scans – in a linear cost – the overflown node’s objects once to identify the distribution of objects’ locations (minimum bounding rectangles (MBRs)) in relative to its node’s bounding rectangle (node’s MBR). It uses objects’ locations to calculate – for each main axis – the split quality factors: expected overlap between resulting nodes, objects distribution evenness among resulting nodes and the perimeter of resulting nodes. The axis with better combined quality factors values is selected as the split axis. The Splitting based on Objects’ Locations Distribution (SOLD) algorithm was implemented and tested against two other splitting algorithms, experiments using synthetic and real data files showed good results and it outperformed both algorithms in index creation tests and data retrieval tests.
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DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2026
·
IF 4.9
Zhenzhen Zhang,Miaomiao Chai,Wei Li,Zhenhui Wang,Xueqian He
Eighteen new sulfonamide-pyrrole derivatives were isolated from a fungus. • New compounds were elucidated by a combination of NMR, HRESIMS and X-ray. • Six compounds showed promising acetylcholinesterase inhibitory activity. Eighteen new sulfonamide-pyrrole derivatives, designated myrosurroles A-R ( 1 - 18 ), were obtained via a late-stage functionalization strategy employing precursor-directed biosynthesis. This was achieved by supplementing cultures of the wetland-derived fungus Myrothecium verrucaria HPU-ZMN with sulfanilamide derivatives. The structures of new compounds were elucidated by NMR, HRESIMS, and X-ray crystallographic analysis. Myrosurroles represent the first compounds featuring a sulfonamide-pyrrole hybrid backbone obtained via a chemobiological approach. Six compounds ( 4, 5 , and 8-11 ) displayed promising acetylcholinesterase (AChE) inhibitory activity, with IC₅₀ values ranging from 1.58 to 4.79 μ M, demonstrating potency on the same order of magnitude as the positive control, donepezil (IC₅₀ = 1.08 μ M). Download: Download high-res image (227KB) Download: Download full-size image
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DOI
高影响因子
Journal of Materials Chemistry A
·
2026
·
IF 9.2
Zhiyu Jin,Lei Chen,Jiayu Li,Xiang Chen,Pengxiang Gao,Jiuxiang Sun,Chong Zhang,Bingcheng Hu
Substituent effects play a pivotal role in modulating the properties of organic ionic compounds through the synergistic electronic and steric effects. The substituent effect is one of the core theoretical foundations for studying structure–property relationships in materials science and organic chemistry. However, in-depth examination of the substituent effects on significant cyclo-pentazolate anion (cyclo-N5−) salts has not been studied. Herein, to explore how different substituents (R) in 4-R-1,5-diaminotetrazolium cations affect the properties of their cyclo-N5− salts, four types of cyclo-N5− salts bearing distinct substituents (−CH3, –CH2COCH3, –CH2CONH2, and –CH2COOCH3) were designed and synthesized. Analysis using X-ray single-crystal diffraction indicates that the crystal structures of these salts vary significantly based on the substituents. Among them, the cyclo-N5− salt with the –CH3 substituent exhibits optimal crystal density and stability. The –CH2CONH2 group improves crystal stability via increased hydrogen-bonding capacity. In contrast, –CH2COCH3 and –CH2COOCH3 lead to reduced stability and crystal density due to larger steric bulk and lack of hydrogen-bonding interactions. Additionally, Hirshfeld surface analysis and fingerprint plots were employed to investigate the interionic interaction regions, revealing extensive van der Waals interactions and the formation of N–H⋯N hydrogen bonds. The cyclo-N5− salt with the –CH3 substituent displays the highest detonation performance (D: 8811.47 m s−1; P: 26.94 GPa), which benefits from a higher enthalpy of formation.
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DOI
高影响因子
JACS Au
·
2025
·
IF 8.7
Hui-Peng Lv,Yong Ai,Wei Hu,Yuqin Susan Xiong,Yan-Ran Weng,Xian-Jiang Song,Yan Qin,Wei-Qiang Liao,Ren-Gen Xiong
Molecule intercalation has shown distinct advantages in modulating the superconducting properties of 2D materials. Chiral molecule intercalation provides a strategy for tuning electronic properties, while this approach has been limited to a few 2D materials such as TaS2 and TiS2. Although extensive research on 2D SnSe2 exists, chiral molecule intercalation in SnSe2 remains unexplored. Herein, we report the first successful electrochemical intercalation of chiral CTA cations (CTA = 3-chloro-2-hydroxypropyltrimethylammonium) into SnSe2 by using piezoelectric R/S-CTA-Cl with a large piezoelectric coefficient of approximately 24 pm/V as the precursors, leading to the formation of superconductors R/S-CTA–SnSe2. Characterization techniques, including powder X-ray diffraction, Raman spectroscopy, and circular dichroism spectroscopy, confirm a significant lattice expansion in SnSe2 and the successful intercalation of chiral CTA cations, while polar R/S-CTA-Cl does not endow R/S-CTA–SnSe2 with piezoelectric/ferroelectric properties. Magnetic susceptibility and electrical transport measurements reveal that the intercalated R/S-CTA–SnSe2 materials exhibit a superconducting transition at around 5 K. Notably, the distinct out-of-plane and in-plane upper critical magnetic fields demonstrate the 2D nature of the intercalated compounds. This work highlights an approach for designing and tailoring superconducting materials through chiral cation intercalation and opens avenues for further exploration of chiral effects in superconductors.
研究领域:
材料科学
·
凝聚态物理
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纳米技术
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电化学
·
固体物理
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产品关联
DOI
PubMed
高影响因子
CHEMISTRY OF NATURAL COMPOUNDS
·
2019
·Vol. 55
·期 6
·1080-1084
·
IF 0.567
Yu Pan,Li Dong-dong,Ni Jun-jun,Xia Chao-jie,Wang Zhen-zhong,Xiao Wei,Ding Gang,Zhao Lin-guo
Four novel betulinic acid (BA) derivatives modified at the C-3 position were prepared by the Mitsunobu reaction and subsequently evaluated for antitumor activity against four common cancer cell lines in vitro. The results from the MTT assay revealed that the four tested compounds showed remarkable cytotoxic activity against four cancer cell lines, much better than BA. Western blotting results indicated that the four compounds, especially compound 2c , caused a significant up-regulation expression of the caspase-12 in CT26 cell. Our results showed that configuration inversions of chiral C-3 of BA could also produce BA derivatives with potent antitumor activity.
研究领域:
药理学
·
肿瘤学
·
有机化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）