COMPOSITES SCIENCE AND TECHNOLOGY
·
2019
·
IF 6.309
Chuanhui Xu,Zhongjie Zheng,Wenchao Wu,Lihua Fu,Baofeng Lin
Thermosetting resin-based composites are applied widely, but they are insoluble and infusible once complete curing so that they may be wasteful when the materials have some damages. Here, we use a simple and efficient method to design an epoxy composite which can be healed and recycled via interesterification reaction at elevated temperature. Carboxylated cellulose nanocrystals (CCNs) with a large number of carboxyl groups on the surface were isolated from cotton by hydrochloric acid and nitric acid, and then were used as crosslinker to react with diglycidyl ether of bisphenol A (DGEBA). Fourier transform infrared (FTIR) spectroscopy result indicates that β-hydroxyl ester bonds were formed between carboxyl groups and epoxy groups , while the equilibrium swelling experiment result confirms the formation of β-hydroxyl ester bond-crosslinked networks. Interestingly, the char yields of composites (>16%), much higher than that of CCNs (7.05%) and DGEBA (4.44%), were about three times higher than the calculated values, showing a significantly improved thermal stability. It was found that the composite with a carboxyl/epoxy = 0.2 has a better and more obvious healing affect at 180 °C than others.
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CELLULOSE
·
2019
·Vol. 26
·期 16
·8829-8841
·
IF 3.917
Huang Hongye,Liu Meiying,Chen Junyu,Mao Liucheng,Wan Qing,Wen Yuanqing,Deng Fengjie,Zhou Naigen,Zhang Xiaoyong,Wei Yen
Abstract Since the first discovery by Tang in 2001, aggregation-induced emission (AIE) phenomenon has attracted considerable research interest in various fields. In this contribution, AIE-active composites (named as An-HPG-β-CD) have been fabricated via conjugation of AIE-active compound An-B(OH) 2 and hyperbranched polyglycerol functionalized β cyclodextrin (HPG-β-CD) based on dynamic phenyl borate for the first time. The potential biomedical applications of these AIE-active composites for biological imaging and drug delivery applications were further explored. The successful preparation of An-HPG-β-CD composites was confirmed through a series of characterization techniques. The An-HPG-β-CD composites possess great water dispersibility, low cytotoxicity, excellent fluorescence properties and uniform size and morphology, which make them promising for cell imaging. Furthermore, the cavities of An-HPG-β-CD composites could be utilized for loading with doxorubicin for drug delivery applications. In conclusion, we have developed a novel method for fabrication of AIE-active An-HPG-β-CD composites through formation of dynamic phenylboronic borate between β cyclodextrin containing hyperbranched polyglycerol and phenylboronic containing AIE dye. These AIE-active composites are of great potential in biological imaging and drug delivery applications. Graphic abstract
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TALANTA
·
2018
·
IF 4.244
Yarong Li,Pengpeng Lu,Jincheng Cheng,Xiaoliang Zhu,Wang Guo,Lijun Liu,Qiang Wang,Chiyang He,Shaorong Liu
A new microporous β -cyclodextrin polymer (MP-CDP) was prepared for the simultaneous solid-phase extraction (SPE) of bisphenol F (BPF), bisphenol A (BPA) and bisphenol AF (BPAF). The MP-CDP was characterized by Fourier transform infrared spectroscopy, solid-phase 13 C nuclear magnetic resonance, thermo-gravimetric analysis, scanning electron microscopy, and nitrogen adsorption and desorption analysis. Results indicated that the MP-CDP had micron-level particle size, microporous structure, a high BET surface area, and a high product yield. Adsorption tests showed that the MP-CDP sorbent had high adsorption ability and fast binding kinetics for bisphenols . Moreover, the MP-CDP presented high extraction efficiencies, high enrichment factor, good reusability and good batch-to-batch reproducibility for SPE of bisphenols. Based on the MP-CDP sorbent, a SPE-HPLC-UV method was developed and successfully applied to simultaneously detect three bisphenols in water samples and orange juice with the recoveries of 95.7–106.3% (RSD = 2.0–5.2%) for BPF, 92.9–107.0% (RSD = 1.5–5.1%) for BPA, and 96.0–103.5% (RSD = 1.7–5.0%) for BPAF, respectively. The limit of detection (S/N = 3) and the limit of quantification (S/N = 10) for all bisphenols in these samples were 0.15 ng/mL and 0.5 ng/mL, respectively. The new MP-CDP can be potentially utilized as a good sorbent for simultaneous SPE of trace bisphenols in environmental water samples and beverages.
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高影响因子
Analytical Methods
·
2018
·Vol. 10
·期 36
·4430-4437
·
IF 2.073
Yanli Zhou,Congming Li,Xiaoqiao Li,Xu Zhu,Baoxian Ye,Maotian Xu
In this study, we developed a novel and facile electrochemical aptasensor for β-amyloid (Aβ) oligomer detection based on metal–organic frameworks (MOFs) as signal probes. By using an aptamer-tethered gold nanoflower (AuNF) modified electrode for target capture and aptamer-tagged gold nanoparticles/Cu-MOF (AuNPs/Cu-MOF) conjugates for sensitive signal generation, an effective sandwich sensor was obtained for the detection of Aβ oligomers. The unique physico-chemical properties of AuNPs/Cu-MOF conjugates, such as high electrochemical activity and large surface area, endow the sensor with excellent analytical performances. The designed aptasensor exhibits a wide linear range from 1 nM to 2 μM with a linear correlation coefficient of 0.996 and a relatively low detection limit of 0.45 nM for the detection of Aβ oligomers. For the evaluation of Aβ oligomers in artificial cerebrospinal fluid, the high recoveries and accuracy indicate the feasibility, which will provide valuable information for the early diagnosis of Alzheimer's disease. Moreover, the proposed electrochemical aptasensor based on multifunctional MOFs will provide a general strategy for sensing other analytes.
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Frontiers in Pharmacology
·
2018
·
IF 3.831
Zhang Zhi-Hao,Li Ming-Hua,Liu Dan,Chen Hua,Chen Dan-Qian,Tan Ning-Hua,Ma Shuang-Cheng,Zhao Ying-Yong
Tubulointerstitial fibrosis is the final common pathway for all kidney diseases leading to chronic kidney disease (CKD). TGF-β/Smad signaling pathway plays a key role in renal fibrosis. Previous studies have revealed that rhubarb extracts attenuated the increase of transforming growth factor-β 1 (TGF-β1) in CKD rats. To gain an in-depth insight into the mechanism of the anti-fibrotic activities of the rhubarb extracts, we investigated the influence of rhubarb extracts on TGF-β/Smad signaling pathway and the influence on metabolome in a rat model of CKD with adenine-induced chronic tubulointerstitial nephropathy. Male Sprague-Dawley rats were divided into four groups, including control, CKD, CKD + petroleum ether extract, CKD + ethyl acetate extract, and CKD + n-butanol extract groups. Kidneys harvested on the week three were evaluated for renal fibrosis, the expression of proteins in TGF-β/Smad signaling pathway and metabolomic study. We found rhubarb extracts suppressed TGF-β/Smad3-mediated renal fibrosis by reducing the TGF-β1, transforming growth factor-β receptor I (TGF-β RI), transforming growth factor-β receptor II (TGF-β RII), Smad2, p-Smad2, Smad3, p-Smad3, and Smad4, meanwhile increased Smad7. In addition, rhubarb extracts mitigated renal injury and dysfunction, and either fully or partially reversed the abnormalities of tissue metabolites. Thus, rebalancing the disorder of TGF-β/Smad signaling and metabolic dysfunction by treatment with rhubarb extracts may represent as an effective therapy for CKD associated with fibrosis.
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BIOSENSORS & BIOELECTRONICS
·
2018
·
IF 8.173
Chengji Sui,Tingting Wang,Yunlei Zhou,Huanshun Yin,Xiangjian Meng,Shenran Zhang,Geoffrey I.N. Waterhouse,Qin Xu,Yuping Zhuge,Shiyun Ai
5-Hydroxymethylcytosine (5hmC) plays an important role in switching genes on and off in mammals, and it is implicated in both embryonic development and cancer progression. Herein, a novel photoelectrochemical (PEC) biosensor was developed for 5hmC detection based on WS 2 nanosheets as the photoactive material and boronic acid functionalized carbon dots (B-CDs) for signal amplification unit. This biosensor can also be used for T4-β-glucosyltransferase (β-GT) activity assessment. Firstly, WS 2 nanosheets and gold nanoparticles (AuNPs) were immobilized on an ITO electrode surface . Then probe DNA was immobilized on this electrode surface via Au-S bond. Afterwards, the complementary DNA containing 5hmC was then captured on the modified electrode surface by hybridization. Subsequently, β-GT transferred glucose from uridine diphosphoglucose to the hydroxyl groups of the 5hmC residues. After glycosylation , B-CDs could further be immobilized on the modified electrode surface resulting in a strong photocurrent . The PEC biosensor afforded high selectivity , excellent sensitivity and good reproducibility, with detection limits of 0.0034 nM and 0.028 unit/mL for 5hmC and β-GT, respectively. Results demonstrate that the photoelectrochemical strategy introduced here based on WS 2 nanosheets and B-CDs offers a versatile platform for hydroxymethylated DNA detection, β-GT activity assessment and β-GT inhibitor screening.
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FOOD HYDROCOLLOIDS
·
2018
·
IF 5.089
Dongwen Fu,Sumeng Deng,David Julian McClements,Lei Zhou,Liqiang Zou,Jiang Yi,Chengmei Liu,Wei Liu
β-carotene was encapsulated in Pickering emulsions stabilized by biopolymer particles formed by wheat gluten nanoparticles (WGN) or wheat gluten nanoparticle-xanthan gum (WGN-XG) complexes. The WGN-XG emulsions had larger initial mean particle diameters (23.9 μm) than the WGN ones (9.4 μm), but they were still stable to aggregation over a wide range of pH values (4–8) and salt levels (0–1000 mM NaCl). They were also effective at protecting β-carotene from chemical degradation during storage, with around 94.3% and 70.1% of the carotenoids being retained after one-month storage at 25 and 37 °C, respectively. WGN-XG and WGN emulsions were both stable to thermal sterilization. An in vitro digestion experiment showed that β-carotene had a higher bioaccessibility in the WGN-XG emulsions than in the WGN ones. These results may facilitate the design of Pickering emulsions with high stability for nutraceutical delivery in food and supplement products.
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DRUG DEVELOPMENT AND INDUSTRIAL PHARMACY
·
2018
·
IF 1.883
Ning Li,Ning Wang,Tingni Wu,Changlu Qiu,Xueting Wang,Shaohong Jiang,Zina Zhang,Ting Liu,Chunliu Wei,Ting Wang
The curcumin (CUR)-hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion complex (CUR-HP-β-CD) was prepared to erase its therapeutic restrictions of poor aqueous solubility and low oral bioavailability. CUR-HP-β-CD was prepared by a simple procedure of water-ethanol cosolvent incubation-lyophilization which may be suitable for scale up production, and characterized by Fourier transform-infrared spectroscopy (FT-IR), powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC), phase solubility method and dissolution study; the in vitro cytotoxicity was assayed by MTT, whereas the in vivo pharmacokinetics was tested by HPLC in rats receiving formulations via intravenous and oral administration, respectively. CUR was successfully encapsulated in HP-β-CD with a loading capacity of about 1:7 of CUR to HP-β-CD mole ratio, which remarkably enhanced drug water solubility and maintained well the antitumour activity of CUR. The CUR-HP-β-CD and free CUR have a similar pharmacokinetic behaviour in rats after intravenous administration; however, the oral bioavailability of CUR was enhanced to 2.77-fold by the HP-β-CD. The CUR-HP-β-CD can be successfully prepared by a simple method, which may be feasible for industrial scaling up, to remarkably increase drug water solubility and oral bioavailability while maintaining its bioactivity and may be a promising therapeutic preparation.
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高影响因子
ANALYST
·
2018
·Vol. 144
·期 2
·504-511
·
IF 3.864
Yin Zhang,Si Meng,Jinhua Ding,Qiwen Peng,Yanyan Yu
Herein, we developed a sensitive graphitic carbon nitride quantum dot (gCNQD)-based fluorescent strategy for β-amyloid peptide monomer (Aβ) determination down to the ng mL−1 level for the first time. To realize this goal, the nanostructured gCNQDs were firstly coordinated with four transition metal ions (Cu2+, Cu+, Fe3+, Zn2+). Our findings showed that the fluorescence (FL) intensity of gCNQDs was quenched in the presence of these metal ions possibly due to the effective chelation with the nitrogen element in gCNQDs and subsequent photoinduced electron transfer (PET) of gCNQDs. The degree of fluorescence quenching was found to be the most intense with the addition of Cu2+ and therefore, we selected Cu2+ as the quencher for the following Aβ determination. Through binding to Cu2+, the introduction of Aβ unexpectedly induced a further decline of FL intensity. Importantly, on account of different peptide sequences coexisting in the same cerebral system, including Aβ1–11, Aβ1–16, Aβ1–38, Aβ1–40 and Aβ1–42, their affinities to Cu2+ could be reflected by the distinguished declining extent of FL intensity. The possible mechanism of Aβ sensing by the probe was clarified by TEM characterization. The developed fluorescent biosensor was demonstrated to give a wide linear range from 1 to 700 ng mL−1 and a low detection limit of 0.18 ng mL−1 for Aβ1–42. In the end, the proposed fluorescence approach was successfully applied to monitoring of Aβ1–42 variations in the cortex and hippocampus of AD rats.
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BIOORGANIC CHEMISTRY
·
2018
·
IF 3.929
Juan Wang,Wei Li,Jingfang Qin,Li Wang,Shenqi Wei,Huang Tang
A series of 6-substituted azaanthraquinone derivatives have been designed, synthesized, and their anti-inflammatory activities, antiaggregation effects on β-amyloid proteins, anticholinesterase and neuroprotective activity were tested. The new derivatives strongly suppressed NO and iNOS production and modulate the production of cytokines by decreasing TNF-a, IL-1β and IL-6 formation in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Meanwhile, the derivatives exhibited a significant in vitro inhibitory activity toward the self-induced Aβ aggregation. While, treatment of SH-SY5Y cells overexpressing the Swedish mutant form of human b-amyloid precursor protein (APPsw) with derivatives was associated with significant reduction of Aβ42 secretion levels. Moreover, the derivatives exhibited moderate inhibitory potency toward acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Further investigations indicated that compound 7b could attenuate H 2 O 2 -induced neurotoxicity toward SH-SY5Y neuroblastoma cells and half of the synthetic compounds were predicted to be able to cross the blood–brain barrier (BBB) to reach their targets in the central nervous system (CNS) according to a parallel artificial membrane permeation assay for BBB. Taken together, azaanthraquinone derivatives targeting multiple pathogenetic factors deserves further investigation for prevention and treatment of AD.
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APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2015
·Vol. 121
·期 1
·193-202
·
IF 1.704
Lü Mengyun,Guan Tengpeng,Li Ai-Hua,Sun Zhijun
In solvothermal synthesis of Er 3+ -doped NaGd 1− x
Yb
x
F 4 nanocrystals, morphology of the nanoparticles is dependent on the molar ratio of the chelating agent (e.g., trisodium citrate) to the lanthanide ions. Usually, addition of chelating agent is reported to be effective only when the molar ratio is below a critical value usually around 1 for the preparation of Er 3+ - and Yb 3+ -doped NaYF 4 nanocrystals. In this work, we found that, by increasing the Yb 3+ concentration, the critical molar ratio can be up to more than 4 in the preparation of Er 3+ -doped NaGd 1− x
Yb
x
F 4 nanocrystals, which provides a new route to control the nanoparticles’ size. The result is particularly useful for the synthesis of small Er 3+ -doped NaGd 1− x
Yb
x
F 4 nanocrystals with high concentration of the Yb 3+ dopant. We also investigated mechanisms on the formation of such particles ( β -NaGd 0.3 Yb 0.7 F 4 :Er 3+ ) with large size in a sub-micrometer scale, i.e., the aggregation-induced crystal growth. In addition, upconversion luminescence properties of the powdery samples were studied, which is shown to be dependent both on size of the nanoparticles and on dosage of the trisodium citrate.
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Polymer Chemistry
·
2012
·Vol. 4
·期 5
·1557-1564
·
IF 5.321
Qiangfang He,Hui Liang,Jiang Lu
Living/controlled polymerization of a salicylaldehyde-functionalized vinyl monomer, 2-hydrox-5-vinylbenzaldehyde (HVB), was achieved by reversible addition–fragmentation chain transfer (RAFT) polymerization with S-1-dodecyl-S′-(α,α′-dimethyl-α′′-acetic acid)trithiocarbonate as the RAFT agent in THF at 65 °C. The resulting well-defined polymer with pendant salicylaldehyde groups could react directly with mono-6-deoxy-6-aminoethyl-β-CD to yield a new β-CD-containing polymeric salicylidene Schiff base PHVB-graft-β-CD with precise structure and high solubility. PHVB-graft-β-CD was then coordinated with zinc ions to give the luminescent PHVB-graft-β-CD/Zn2+ complex which displayed intense blue fluorescence with a maximum emission peak around 452 nm in DMF. The obtained PHVB-graft-β-CD/Zn2+ tended to self-aggregate in aqueous media because of the hydrophobic nature of PHVB-graft-β-CD backbone, and therefore its fluorescence emission in water was weak as a result of the aggregation-induced fluorescence quenching. An obvious decrease of the aggregate size from 290 nm to 40 nm in aqueous media was observed after adding 1.0 equiv. (relative to β-CD moieties) of the guest molecule, sodium adamantanecarboxylate (Ad-COONa), and concomitantly a remarkable fluorescence enhancement (4.5-fold) was obtained due to a better water-dispersibility of PHVB-graft-β-CD/Zn2+. The incorporation of carboxylic groups on the PHVB-graft-β-CD/Zn2+ complex via the inclusion with Ad-COONa also endowed the resulting fluorescent nanoparticles with a further protein-binding function. Upon gradual addition of the fluorescent nanoparticle aqueous dispersion to the BSA buffer solution, the fluorescence intensity at ∼349 nm corresponding to BSA decreased, while the fluorescence intensity of the nanoparticle at ∼429 nm increased through an isoemissive point at 388 nm, indicating the occurrence of efficient fluorescence resonance energy transfer (FRET) between the fluorescent nanoparticles and protein. This novel protein sensing capability would give the fluorescent nanoparticles great potential in biotechnology.
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