Minerals
·
2015
·Vol. 5
·期 4
·654-664
·
IF 1
Wei Ge,Hongqiang Li,Yanzeng Ren,Feiyu Zhao,Shaoxian Song
The hydrophilic flocculation of pyrite fines in aqueous suspensions with corn starch was studied by measuring particle size distribution, microscopy observation and micro-flotation. Furthermore, the interaction of corn starch with pyrite was investigated by determining the adsorption density and based on zeta potential measurements and X-ray photoelectron spectrometer (XPS) analysis in this work. The results of the particle size distribution measurement show that corn starch can effectively aggregate pyrite fines, and the pyrite floccules (flocs) are sensitive to mechanical stirring. The micro-flotation results suggest that the mechanical entrainment of pyrite fines in flotation can be effectively eliminated through the formation of large-size flocs. The zeta potential of pyrite particles decreases with the addition of corn starch. The XPS results prove that carboxyl groups are generated on the digested corn starch, and both iron hydroxyl compounds and ferrous disulfide on the pyrite surface can chemically interact with the corn starch digested by sodium hydroxide.Keywords:hydrophilic flocculation;pyrite fines;corn starch;mechanical entrainment;adsorption
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CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS
·
2015
·
IF 2.321
Jing-Jing Kong,Zeng-Ping Chen,Yao Chen,Xiu-Fang Yan,Ru-Qin Yu
Accurate quantification of genomic DNA is fundamental to many molecular analyses such as diagnostic assays and genotyping. Due to relatively low and varying extraction rates of DNA from cell lysates by genomic DNA extraction kits, it is desired to quantitatively determine DNA contents directly in cell lysates. However, the coexistence of scatterers (e.g., cell debris), absorbers, and intrinsic fluorophores in cell lysates prevents either UV–Vis spectrophotometric methods or fluorometric methods based on fluorescent dyes and ratiometric models to be directly applied to cell lysates. In this contribution, a novel fluorometric method based on an advanced chemometric model which can effectively eliminate the effects of scatterers and absorbers on fluorescence spectra of cell lysates was proposed for the direct quantification of DNA in lysates of CEM cells. Without cumbersome prior DNA extraction, the proposed method achieved quite stable and accurate DNA quantification with recovery rates in the range of 89%–115%, considerably better than that of either the fluorometric method based on the ratiometric model or the UV–Vis spectrophotometric method coupled with DNA extraction. The proposed method has the advantages of rapidness, simplicity, and high precision, and can be developed into a promising alternative for accurate quantification of genomic DNA.
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JOURNAL OF CHROMATOGRAPHY A
·
2014
·
IF 4.258
Qian Wu,Dapeng Wu,Yafeng Guan
For in vivo extraction of trace and polar components in tissues, extraction materials should be biocompatible, highly permeable to matrix and have high extraction capacity for polar and ionic compounds. In this study, nanofibers (∼200 nm) with rough polyaniline (PAn) sheath were prepared successfully for the first time by coaxial electrospinning and coelectrospun polymer sacrificing method. The nanofibers (0.5 mg) were then compressed into tiny bar ( Φ 1 mm × 2 mm) and inserted directly into the aloe leaf for in vivo extraction of trace phytohormones. Due to the large surface area (13.97 m 2 /g) of nanofibers and large through pores formed between fibers, high extraction capacity (up to 10 μg/bar) and permeability to tissue matrix of the tiny bar can be obtained. Moreover, PAn sheath has high adsorption equilibrium constants (10 7 –10 8 mL/mol) for acidic phytohormones in aloe leaf. Four phytohormones were detected by in vivo extraction with a spatial resolution of 3–8 mm 3 , temporal resolution of 20 min, and limit of detection down to 60 pg/g. The quantification results were well met with that by traditional in vitro organic solvent extraction.
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RSC Advances
·
2013
·Vol. 3
·期 44
·21715-21721
·
IF 2.562
Zenghong Song,Meirong Cai,Yongmin Liang,Mingjin Fan,Feng Zhou,Weimin Liu
Methoxy tris-ethoxy methylene benzotriazole (BTAG3) was synthesized and has good solubility in multiply-alkylated cyclopentanes (MACs) only when equal molar ratios of lithium salts, LiBF4, LiPF6, LiSO3CF3 or LiTFSI, were co-added into MACs due to the formation of ionic liquids (ILs), [Li(BTAG3)]BF4, [Li(BTAG3)]PF6, [Li(BTAG3)]SO3CF3 and [Li(BTAG3)]TFSI. The as-synthesized ILs have better solubilities in MACs than the conventional imidazolium ILs, 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (L-F108) and 1-butyl-3-methylimidazolium tetrafluoroborate (L-B104) or the unfunctionalized lithium-based IL, [Li(G3)]TFSI, which are insoluble in MACs. They were evaluated as anti-wear and anti-corrosion additive of MACs for steel–steel contact at room temperature (RT). It was found that the ILs possessed excellent friction-reducing and anti-wear properties in MACs compared with zinc dialkyldithiophosphate. Besides, the presence of benzotriazole means that these synthetic ILs have good anti-corrosion properties compared with the conventional IL, L-B104.
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BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2015
·Vol. 38
·期 5
·939-946
·
IF 1.997
Zeng Chaoxi,Qi Suijian,Li Zhigang,Luo Riming,Yang Bo,Wang Yonghua
A water-in-ionic liquid microemulsion ([Bmim]PF 6 /Tween20/H 2 O) was applied as reusable reaction medium to esterify phytosterols with fatty acid by Candida rugosa lipase (CRL) successfully. Two kinds of commercial CRLs, AY30 and AYS which cannot effectively catalyze esterification in conventional reaction system were found effective in the microemulsion system. Effects of reaction parameters on esterification were investigated; results showed that the conversion rate of 87.9 and 95.1 % was obtained in 24 and 48 h of reaction, respectively, under the optimized condition: the molar ratio of water to Tween 20 ( w
0 value) at 5.4, Tween 20 at a concentration of 305 mM, 50 °C,pH 7.4, 10 % of enzyme loading (w/w, with respect to total reactants), and phytosterols/lauric acid molar ratio of 1:2. Moreover, by using n-hexane as the extraction agent, the lipase-encapsulated microemulsion could be reused at least seven times (>168 h) without significant changes in the conversion rate, while achieving a purpose of simple separation and purification.
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International Journal of Inflammation
·
2014
·
IF 0
Hang Yang,Haili Qi,Jingli Ren,Jing Cui,Zhenfeng Li,Helge L. Waldum,Guanglin Cui
Nuclear factor-kappaB (NF-κB)/interleukin (IL-6) pathway links chronic inflammation to colitis associated cancer (CAC). In this study, we examined the dynamic temporal changes of the NF-κB/IL-6 pathway during the procession of experimental CAC mouse model. Mice were sacrificed after induction for 14, 16, 18, and 22 weeks for the examination of tumor burden, inflammation degree, and protein level of NF-κB and IL-6 in bowel tissues. The results showed that tumor burden and inflammation severity in the bowels were gradually increased over the observed time-points. The expressions of IL-6 and NF-κB proteins were gradually increased after induction of dysplastic lesions over times. These data provide new information on the dynamic temporal changes of NF-κB/IL-6 pathway in relation to CAC development that may be relevant in the design of future investigations of therapeutic interventions to effectively target CAC processes.
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JOURNAL OF NANOPARTICLE RESEARCH
·
2014
·Vol. 16
·期 7
·1-14
·
IF 2.278
Ma Xiaona,Shu Chang,Guo Jing,Pang Lili,Su Lin,Fu Degang,Zhong Wenying
Abstract A new targeted drug delivery system (DDS) based on oxidized single-wall carbon nanohorns (oxSWCNHs) was developed. Sodium alginate (SA) was used to modify oxSWCNHs to improve its dispersibility and biocompatibility, the first time such a modification to oxSWCNHs was reported. The humanized anti-vascular endothelial growth factor (anti-VEGF) monoclonal antibody was bound to the SA as targeting group to selectively kill the tumor cells. Doxorubicin hydrochloride (DOX) was conjugated to oxSWCNHs in basic pH solution by π–π stacking, and its release was triggered by the lower pH as the micro-environment of the tumor. Quantitative analyses showed that the DOX@oxSWCNHs/SA complexes contained 1 g DOX per gram of oxSWCNHs. Cell experiment showed that the DOX@oxSWCNHs/SA-mAb effectively targeted the human breast adenocarcinoma (MCF-7) cells and rarely adhered to the human embryonic kidney 293 (HEK293) cells. And the anticancer effects of the complexes were higher than those of the free DOX. Pharmaceutical efficiency in vivo showed that the relative tumor volumes (RTV) of normal saline (NS) group, oxSWCNH/SA-mAb (2.5 mg/kg) group, DOX (2.5 mg/kg) group, and DOX@oxSWCNHs/SA-mAb (2.5 mg/kg) group were approximately 61, 56, 14, and 7.2, respectively. In addition, higher drug dose (5 mg/kg) of DOX@oxSWCNHs/SA-mAb resulted in a better antitumor activity. Histopathological studies in mice confirmed that the DOX@oxSWCNHs/SA-mAb complexes did not demonstrate any detectable hepatotoxicity, cardiotoxicity, and nephrotoxicity. Graphical abstract
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ACS Nano
·
2014
·
IF 12.033
Enguo Ju,Zhen Liu,Yingda Du,Yu Tao,Jinsong Ren,Xiaogang Qu
Probes for detecting highly reactive oxygen species (hROS) are critical to both understanding the etiology of the disease and optimizing therapeutic interventions. However, problems such as low stability due to autoxidation and photobleaching and unsuitability for biological application in vitro and in vivo, as well as the high cost and complex procedure in synthesis and modification, largely limit their application. In this work, binary heterogeneous nanocomplexes (termed as C-dots-AuNC) constructed from gold clusters and carbon dots were reported. The fabrication takes full advantages of the inherent active groups on the surface of the nanoparticles to avoid tedious modification and chemical synthetic processes. Additionally, the assembly endowed C-dots-AuNC with improved performance such as the fluorescence enhancement of AuNCs and stability of C-dots to hROS. Moreover, the dual-emission property allows sensitive imaging and monitoring of the hROS signaling in living cells with high contrast. Importantly, with high physiological stability and excellent biocompatibility, C-dots-AuNC allows for the detection of hROS in the model of local ear inflammation.
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MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 10
·3833-3840
·
IF 4.58
Ma Liling,Sun Shan,Wang Yuhui,Jiang Kai,Zhu Jiali,Li Jun,Lin Hengwei
The authors describe a fluorometric nanoprobe for hypochlorite ion. It was prepared by covalently linking o-phenylenediamine to graphene quantum dots (GQDs). The probe displays green fluorescence with excitation/emission peaks at 440/534 nm. In the presence of chlorite, oPD is oxidized to form a quinone-iminium compound which induces a reduction in fluorescence intensity. The nanoprobe enables chlorite to be determined with a 69 nM limit of detection. The probe is highly selective, well water soluble and biocompatible. It was successfully employed in the determination of chlorite in spiked tap water and living cells. The method is believed to represent a promising tool for the determination of chlorite in environmental, biological and clinical samples.
A photoinduced electron transfer (PET) fluorimetric probe for chlorite detection based on o-phenylenediamine (oPD) modified graphene quantum dots (GQDs). It was applied to imaging of chlorite in MCF-7 cells.
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ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Yunfei Xie,Wangmei He,Fang Li,Thalagalage Shalika Harshani Perera,Lin Gan,Yingchao Han,Xinyu Wang,Shipu Li,Honglian Dai
Biocompatible, biodegradable, and luminescent nano material can be used as an alternative bioimaging agent for early cancer diagnosis, which is crucial to achieve successful treatment. Hydroxyapatite (HAP) nanocyrstals have good biocompatibility and biodegradability, and can be used as an excellent host for luminescent rare earth elements. In this study, based on the energy transfer from Gd3+ to Eu3+, the luminescence enhanced imaging agent of Eu/Gd codoping HAP (HAP:Eu/Gd) nanocrystals are obtained via coprecipitation with plate-like shape and no change in crystal phase composition. The luminescence can be much elevated (up to about 120%) with a nonlinear increase versus Gd doping content, which is due to the energy transfer (6PJ of Gd3+ → 5HJ of Eu3+) under 273 nm and the possible combination effect of the cooperative upconversion and the successive energy transfer under 394 nm, respectively. Results demonstrate that the biocompatible HAP:Eu/Gd nanocrystals can successfully perform cell labeling and in vivo imaging. The intracellular HAP:Eu/Gd nanocrystals display good biodegradability with a cumulative degradation of about 65% after 72 h. This biocompatible, biodegradable, and luminescence enhanced HAP:Eu/Gd nanocrystal has the potential to act as a fluorescent imaging agent in vitro and in vivo.
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ONCOLOGY REPORTS
·
2016
·Vol. 35
·期 5
·3059-3067
·
IF 2.486
Zhu Chen,En-Hua Xiao,Zhen Kang,Wen-Bin Zeng,Hui-Long Tan,Hua-Bing Li,Du-Jun Bian,Quan-Liang Shang
The present study aimed to assess the in vitro and in vivo magnetic resonance imaging (MRI) features of chlorotoxin (CTX)-conjugated superparamagnetic iron oxide (SPIO) nanoprobes. CTX-conjugated nanoprobes were composed of SPIO coated with polyethylene glycol (PEG) and conjugated with CTX. The nanoprobes were termed SPIO-PEG-CTX. MRI of the SPIO and SPIO-PEG-CTX solutions at a different concentration was performed with a 3.0-T MRI scanner (Philips Achieva 3.0T X Series; Phillips Healthcare, The Netherlands). Rabbit VX2 hepatocarcinoma was established by a traditional laparotomy method (injection of the tumor particles into the liver using a 15G syringe needle) following approval by the institutional animal care and use committee. Contrast-enhanced MRI of VX2 rabbits (n=8) was performed using the same MRI scanner with SPIO‑PEG-CTX solutions as the contrast agent. Data were analyzed with calibration curve and a paired t-test. The SPIO-PEG-CTX nanoparticles were successfully prepared. With increasing concentrations of the solutions, the MRI signal intensity was increased at T1WI, but decreased at T2WI, which were the same as that for SPIO. Rabbit VX2 carcinoma appeared as a low MRI signal at T1WI, and high at T2WI. After injection of the contrast agent, the MRI signal of carcinoma was decreased relative to that before injection at T2WI (1,161±331.5 vs. 1,346±300.5; P=0.004<0.05), while the signal of the adjacent normal hepatic tissues was unchanged (480.6±165.1 vs. 563.4±67.8; P=0.202>0.05). The SPIO-PEG-CTX nanoparticles showed MRI negative enhancement at T2WI and a targeting effect in liver cancer, which provides the theoretical basis for further study of the early diagnosis of hepatocellular carcinoma.
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ANALYTICAL CHEMISTRY
·
2016
·
IF 5.886
Changhui Liu,Weiju Chen,Zhihe Qing,Jing Zheng,Yue Xiao,Sheng Yang,Lili Wang,Yinhui Li,Ronghua Yang
By virtue of its high sensitivity and rapidity, Fenton reaction has been demonstrated as a powerful tool for in vitro biochemical analysis; however, in vivo applications of Fenton reaction still remain to be exploited. Herein, we report, for the first time, the design, formation and testing of Fenton reaction for in vivo fluorescence imaging of hydrogen peroxide (H2O2). To realize in vivo fluorescence imaging of H2O2via Fenton reaction, a functional nanosphere, Fc@MSN-FDNA/PTAD, is fabricated from mesoporous silica nanoparticle (MSN), a Fenton reagent of ferrocene (Fc), ROX-labeled DNA (FDNA), and a cationic perylene derivative (PTAD). The ferrocene molecules are locked in the pore entrances of MSN, and exterior of MSN is covalently immobilized with FDNA. As a key part, PTAD acts as not only the gatekeeper of MSN but also the efficient quencher of ROX. H2O2 can permeate into the nanosphere and react with ferrocene to product hydroxyl radical (·OH) via Fenton reaction, which cleaves FDNA to detach ROX from PTAD, thus in turn, lights the ROX fluorescence. Under physiological condition, H2O2 can be determined from 5.0 nM to 1.0 μM with a detection limit of 2.4 nM. Because of the rapid kinetics of Fenton reaction and high specificity for H2O2, the proposed method meets the requirement for real applications. The feasibility of Fc@MSN-FDNA/PTAD for in vivo applications is demonstrated for fluorescence imaging of exogenous and endogenous H2O2 in cells and mice. We expect that this work will not only contribute to the H2O2-releated studies but also open up a new way to exploit in vivo Fenton reaction for biochemical research.
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