Science China-Chemistry
·
2020
·Vol. 63
·期 7
·924-935
·
IF 6.356
Yuan Haifeng,Zhao Yan,Yang Chan,Zhang Cheng,Yang Yue,Meng Hongmin,Huan Shuangyan,Song Guosheng,Zhang Xiaobing
For chemotherapy, drug delivery systems often suffer from the inefficient drug loading capability, which usually cause systems toxicity and extra burden to excrete carrier itself. Moreover, the cancer therapeutic efficacy is also greatly limited by the specificity of tumor microenvironment for reactive oxygen species (ROS) based cancer therapeutic strategy ( e.g. , chemodynamic therapy). Herein, we have developed metal-drug coordination nanoplatform that can not only be responsive to tumor microenvironment but also modulate it, so as to achieve efficient treatment of cancer. Excitingly, by employing small molecule drug (6-thioguanine) as ligand copper ions, we achieve a high drug loading rate (60.1%) and 100% of utilization of metal-drug coordination nanoplatform (Cu-TG). Interestingly, Cu-TG possessed high-efficiently horseradish peroxidase-like, glutathione peroxidase-like and catalase-like activity. Under the tumor microenvironment, Cu-TG exhibited the self-reinforcing circular catalysis that is able to amplify the cellular oxidative stress, inducing notable cancer cellular apoptosis. Moreover, Cu-TG could be activated with glutathione (GSH) and facilitated for GSH triggered 6-TG release, higher selective therapeutic effect toward cancer cells, and GSH activated T 1 weight-magnetic resonance imaging. Based on the above properties, Cu-TG exhibited magnetic resonance imaging (MRI) guiding, efficient and synergistic combination of chemodynamic and chemotherapy with self-reinforcing therapeutic outcomes in vivo .
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 150
·期 12
·3553-3560
·
IF 2.482
Tian Yi,Zhang Ruoqi,Zhao Wenguang,Wen Sha,Xiang Yanping,Liu Xianxiang
Abstract Alkyl levulinates are important biobased chemicals with great fuel-blending properties and good reactivity. In this work, a new functionalized nitrogen-containing organic polymer bearing sulfonic acid groups (PDVTA-SO 3 H) was successfully prepared and studied for the esterification of levulinic acid with alcohols to produce alkyl levulinates. The results showed that this sulfonic acid-functionalized organic polymer possessed high catalytic activity, and the yield of n -butyl levulinate reached 97.4% under the mild conditions. PDVTA-SO 3 H exhibited strong acidic sites and high stability, and would be well expected to be a potential candidate better than some commercial sulfonic solid catalysts for alkyl levulinates production. The catalyst had been reused without any treatment for five times and the results proved its potential for industrial applications. Graphic Abstract
A new sulfonic acid-functionalized organic polymer showed high activity in the conversion of biomass derived levulinic acid into alkyl levulinates.
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2020
·Vol. 13
·期 3
·621-629
·
IF 8.183
Pan Jialiang,Guo Honggui,Wang Min,Yang Hui,Hu Haowen,Liu Peng,Zhu Hongwei
Although Fe 3 O 4 particles have exhibited excellent microwave absorbing capacity and widely used in practical application due to the synergistic effect of magnetic loss and dielectric loss, their applications are still limited for the required high mass fraction in absorbers. To overcome this problem, the development of Fe 3 O 4 materials with low dimensional structures is necessary. In this study, the shape anisotropic Fe 3 O 4 nanotubes (NTs) with low mass ratios were applied to realize efficient microwave absorption. The NTs with different aspect ratios were prepared through facile electrospinning followed by two-step thermal treatments and mechanical shearing. The cross-linked nanotubular structure enabled the absorbers to have much higher electrical conductivity, multiple scattering, polarization relaxation and better anti-reflection surface, while the shape anisotropic NTs maintained significant multiple resonances with stronger coercivity. These all were beneficial to microwave absorption with enhanced dielectric loss, magnetic loss and sterling impedance matching. Results showed that the absorber with 33.3 wt.% of short Fe 3 O 4 NTs had minimum reflection loss of -58.36 dB at 17.32 GHz with a thickness of 1.27 mm, and had the maximum effective absorbing bandwidth (EAB) of 5.27 GHz when the thickness was 1.53 mm. The absorber with 14.3 wt.% of long Fe 3 O 4 NTs presented the widest EAB in certain radar band with attenuated 80.75% X band and 85% Ku band energy bellow -10 dB at the thickness of 2.65 and 1.53 mm, respectively. This study provided an approach for the development of shape anisotropic magnetic absorbing materials, and broadened their practical applications as magnetic absorbers.
✓ 已验证
产品关联
DOI
高影响因子
WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
·
2020
·Vol. 36
·期 3
·1-10
·
IF 2.477
Shi Chaohong,Gu Wenjie,Zhu Nengwu
Biorecovery is emerging as a promising approach to retrieve gold from various sources, while its efficiency is usually restricted by the limited functional groups on natural microbial biomass surface. This study aims to intensify Pycnoporus sanguineus boosted sorption-reduction coupled gold biorecovery process via microbial surface modification. Results showed that grafting polyallylamine hydrochloride onto P. sanguineus biomass surface increased amino group content on microbial biomass surface from 1.29 to 2.81 mmol/g. When applying modified biomass to gold biorecovery with initial gold concentrations of 1.0, 2.0 and 3.0 mM, biosorption equilibrium time shortened to the 12.5%, 37.5% and 41.7% of those obtained with pristine biomass, and sorption rate constants correspondingly increased to 11.2, 3.1 and 3.7 folds as well. Maximum sorption capacity increased 30% and the affinity between biomass and gold enhanced heavily after microbial surface modification. Meanwhile, microbial surface modification favored gold reduction and gold nanoparticles (AuNPs) formation. The change of microbial biomass morphology from smooth surface with some branched structure to layered stacking structure with many pores and the increase of amino group content on microbial biomass surface were the main impetus for the gold bioreocovery process intensification.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 3
·1-10
·
IF 6.232
Zhu Wanying,Zhou Ying,Tao Mengdan,Yan Xiaoqiang,Liu Yan,Zhou Xuemin
A novel electrochemical and fluorescence dual-signal assay was developed for the determination of hydrogen peroxide (H 2 O 2 ) based on Fe 3 O 4 @MnO 2 and N-doped carbon dots (NCDs). Fe 3 O 4 @MnO 2 was not only applied as the recognizer for H 2 O 2 but also served as the fluorescence quencher and electrochemical enhancer. This permits the dual-signal readout of the analytical system. In the absence of H 2 O 2 , the NCDs were quenched by Fe 3 O 4 @MnO 2 , and the oxidation of the electrochemical probe ferrocene (Fc) was catalyzed by Fe 3 O 4 @MnO 2 . In the presence of H 2 O 2 , MnO 2 was reduced to Mn 2+ , leading to the fluorescence recovery of NCDs and the reduction in the oxidation signal of Fc. By combining the electrochemical method and the fluorescence assay, more comprehensive and valuable information for H 2 O 2 determination was provided to meet different analytical demands. The method exhibits good repeatability and selectivity with a detection limit of 1.0 μM for the fluorescence assay and 0.6 μM for the electrochemical method. The proposed approach holds great potential for probing released targets from living cells.
Graphical abstract
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER BULLETIN
·
2020
·Vol. 78
·期 2
·753-768
·
IF 2.014
Wu Jie,Zhai Wentao,Gao Xue,Liu Bingxin,Zhang Ruling,Yu Yueqin
Well-defined triblock copolymers poly( N -isopropylacrylamide)-b-poly(3-methacryloxypropyltrimethoxysilane)-b-poly( N -isopropylacrylamide) (PNIPAM-b-PMEMO-b-PNIPAM) with varying block ratios were successfully synthesized via reversible addition–fragmentation chain transfer polymerization. The amphiphilic triblock copolymers showed surfactant-like behavior in aqueous solution and could easily self-assemble into dendritic micelles with hydrophobic PMEMO as the core and hydrophilic PNIPAM as the shell when the copolymer concentration exceeded the critical micelle concentration (CMC). Transmittance measurements showed the triblock copolymers were thermosensitive, and it was worth noting that the lower critical solution temperature (LCST) values of copolymers exceeded pure PNIPAM to about 35.3 °C, which was very close to physiological temperature of human body. This was attributed to the effect of Si–O–CH 3 hydrolysis in polymers. The effect of a series of inorganic salts on thermosensitivity of PNIPAM-b-PMEMO-b-PNIPAM was investigated, and our results suggested that the block copolymers maintained good thermosensitivity in all salt solutions. The LCST did not change significantly in different concentrations of NaCl, CaCl 2 and MgCl 2 solutions, which proved the polymer had good salt resistance. Dynamic light scattering experiments showed that the micelles were well dispersed at about 120 nm below LCST with a small polydispersity index. In addition, the drug-loading experiments of micelles showed high drug encapsulation efficiency indicating their potential as drug carriers.
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2020
·Vol. 412
·期 11
·2433-2441
·
IF 3.637
Cheng Jinyan,Wang Xuedong,Nie Tianyin,Yin Long,Wang Shiman,Zhao Yanchu,Wu Huimin,Mei He
Dopamine homeostasis is an important clinical diagnostic index, because an abnormal level in the human body is closely related to certain serious diseases. Herein, a novel electrochemical sensing platform based on gold nanobipyramid/multi-walled carbon nanotube hybrids (AuNBP/MWCNTs) is developed to detect dopamine in human fluids. Using field emission scanning electron microscopy, it is observed that AuNBPs of about 60 nm with two pyramids are well dispersed on the surface of MWCNTs. Energy-dispersive X-ray spectrometry, X-ray diffraction and X-ray photoelectron spectroscopy confirm that AuNBPs are self-assembled onto the surface of MWCNTs to form the hybrids. Cyclic voltammetry reveals that the AuNBP/MWCNTs exhibit good electrocatalytic activity toward dopamine oxidation owing to the synergistic effects of AuNBPs and MWCNTs. In addition, both cyclic voltammetry and differential pulse voltammetry display three well-resolved and distinct oxidation peaks on the AuNBP/MWCNT-modified glassy carbon electrode. Based on AuNBP/MWCNTs, the newly developed electrochemical sensor is used to detect dopamine in the presence of ascorbic acid and uric acid over a wide linear range from 50 nM to 2.7 mM and a low detection limit of 15 nM (at S/N = 3). The electrochemical sensor can also be applied for the quantitative analysis of dopamine in real samples.
A novel electrochemical sensing platform based on gold nanobipyramid/multi-walled carbon nanotube hybrids (AuNBP/MWCNTs) was proposed to detect dopamine in the presence of ascorbic acid and uric acid.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 5
·3899-3909
·
IF 2.22
Tian Chen,Zhou Min,Hua Zhongqiu,Yuan Wenjing,Wu Yi,Tian Xuemin,Song Tao
In the present work, gas sensors based on Cr 2 WO 6 nanoparticles were fabricated by a screen-printing technique, and the sensing properties were characterized with acetone and other typical reducing gases under both dry and humid air backgrounds. Interestingly, it was found that Cr 2 WO 6 sensors showed a p-type conduction characteristic with a highly sensitive response to acetone vapor in a relatively low concentration. In the presence of humidity, resistances of Cr 2 WO 6 sensors were significantly increased; nevertheless, sensor responses were obviously inhibited. In addition, the basic sensing mechanism of Cr 2 WO 6 sensor was also investigated based on oxygen adsorption behavior and catalytic properties of Cr 2 WO 6 surface. According to experimental results, it is proposed that the resistive responses of Cr 2 WO 6 sensor to reducing gases were highly oxygen-dependent, indicating that the surface oxygen adsorption and reaction also played the basic role in the sensing process as that observed in typical n-type MOS sensors. Additionally, sensors also suffered from a high cross-sensitivity to water vapor due to the competition of chemisorption of water and oxygen on the surface of Cr 2 WO 6 .
✓ 已验证
产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2020
·Vol. 78
·期 1
·335-358
·
IF 2.014
Yuan Haikuan,Wang Chengchong,Liu Xiaodi,Lu Jie
In order to ameliorate the trade-off effect in pervaporation process and to reduce the micro-phase separation of hybrid membrane, polyvinyl alcohol (PVA)-perfluorosulfonic acid (PFSA) blending materials were modified by two inorganic components to prepare PVA-PFSA-Si hybrid membrane. PVA-PFSA-Si membrane was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), contact angle measurements, scanning electron microscopy (SEM), positron annihilation lifetime spectrometer (PALS) and swelling measurements. As a second inorganic modifier, the effect of γ-glycidyloxypropyl trimethoxysilane (GPTMS) on the morphology of hybrid membrane was better than that of γ-aminopropyl triethoxysilane (APTEOS). PVA-PFSA-Si/polyacrylonitrile (PAN) composite membrane was used to pervaporatively dehydrate ethyl acetate (EAc)/H 2 O binary, EAc/ethanol (EtOH)/H 2 O ternary EAc/acetic acid (HAc)/EtOH/H 2 O quaternary solutions. At feed temperature of 40 °C, M8 membrane had the permeation fluxes ( J ) of 262.7, 215.2 and 182.6 g m −2 h −1 and the separation factors ( α ) of 6673, 3453 and 5374 for pervaporative dehydration of EAc/H 2 O (98/2, wt%) binary, EAc/EtOH/H 2 O (96/2/2, wt%) ternary and EAc/HAc/EtOH/H 2 O (96/1/1/2, wt%) quaternary solutions, respectively. The pervaporative results showed that PVA-PFSA-Si membrane had the excellent dehydration performances for EAc binary or multicomponent aqueous solutions.
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Peptide Research and Therapeutics
·
2020
·Vol. 26
·期 4
·2285-2296
·
IF 1.5
Chen Xiaolong,Hu Cuihua,Zhang Yanan,Hao Wenjing,He Xu,Li Qing,Huang Yuxi,Huang Yibing,Chen Yuxin
Conjugation of cell-penetrating peptides to anticancer peptides is an effective strategy to enhance tumor treatment. The hybrid peptide, kla-TAT, by attaching the TAT peptide to the C-terminus of the pro-apoptotic peptide kla exhibited strong anticancer activity when co-administration with other peptide, but the systematic mechanism was not clear. In this study, the mechanisms of action of kla-TAT including the uptake pathway, distribution in cytoplasm, apoptosis-inducing ability and micro-morphology were investigated. The results indicated that the hybrid peptide internalized into A549 cells through two transmembrane mechanisms: endocytosis mediated by the clathrin-mediated endocytosis route and the rapid membrane disruption mechanism. Peptides that were endocytosed could interact with the mitochondrial membrane, while peptides internalized by disrupting the cell membrane caused disruption of the mitochondrial membrane. Thus, the hybrid kla-TAT peptide transfers through the cell membrane, inducing apoptosis by destroying the mitochondrial membrane and causethe expression of cyclin-D1 down-regulation. Meanwhile, the changes of the micro-morphology of the cancer cells was detected using atomic force microscope (AFM) and scanning electron microscope (SEM), which provided the visualized evidence for the mechanism of the peptides.
✓ 已验证
产品关联
DOI
高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 9
·5055-5069
·
IF 4.21
Shan Bo,Xiong Yuzhu,Li Yihang,Yang Hang,Chen Yuanfu
It is urgent and significant to develop a thermal interface material (TIM) with both high thermal conductivity and excellent mechanical strength for high-performance electronic devices. For the first time, we designed and fabricated a sandwich structured TIM, constructed by a cellulose nanofiber (CNF) core layer sandwiched by reduced graphene oxide (rGO) shell, with copper ions as a crosslinker, via a facile and scalable vacuum filtration process. The continuous rGO layers on the surface of the composite provided a good thermal conductive pathway for the composite films. The thermal conductivity of the sandwiched films with 8.0 wt% rGO reached 29.5 W/mK, which is over eight times than the CNF films, and realized an ultrafast thermal diffusion time at 73 ms. The sandwich structure combined with the cross-linker of copper ions also plays a synergistic role in construct mechanical strength. Compared to the CNF, the tensile strength of the sandwiched films with 8.0 wt% rGO unprecedentedly reached 314 MPa (nearly three times of bare CNF films), and the elongation increased 63%. In addition, the films also shows high water stability and excellent flexibility, which makes it a very promising for advanced flexible or wearable electronics. This work provides a new insight in rational structure design and novel scalable fabrication strategy to develop TIM with outstanding mechanical strength and thermal conductivity.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 19
·8170-8184
·
IF 3.553
Duan Guangyu,Cao Yutong,Quan Jiayou,Hu Zuming,Wang Yan,Yu Junrong,Zhu Jing
This paper reports that a novel polyimide dielectric composite with three-dimensional (3D) thermally conductive networks and enhanced breakdown strength was firstly fabricated by filling with core-double-shell structured F-BA fillers. The F-BA particles were composed of nano-sized boron nitride (nBN) and polydopamine-coated spherical alumina (PDA@Al 2 O 3 ). Moreover, to ameliorate interfacial compatibility between F-BA fillers and PI matrix as well as restrain phonons scattering during propagation, 1,6-Diisocyanatohexane (HDI) was innovatively used as “bridge agent” to connect and functionalize nBN and PDA@Al 2 O 3 particles to generate core-double-shell structure. The results revealed that breakdown strength of PI dielectric composite with 25 wt % F-BA fillers was increased to 146.3 MV·m −1 , showing an increment of 68.5% in comparison with that of pure PI. Furthermore, the thermal conductivity of F-BA/PI composite with 25 wt % F-BA fillers increases to 6.41 W/m·K of in-plane direction and 1.01 W/m·K of through-plane direction, respectively, which shows 36 and 6 times higher than polyimide of 0.18 W/m·K. For dielectric properties of F-BA/PI composite, the dielectric constant and loss are less than 3.5 and 0.02, respectively. Considering these properties, the prepared PI dielectric composite shows potential application in high-performance electronic devices.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）