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Objective:To investigate the effect of copper ion(Cu2+) on the aggregation and neurotoxicity of Aβ, and affirm the role of Danggui Shaoyaosan in vitro,the Neuroblastoma (SH-SY5Y) cells treated with β-amyloid 1-42 (Aβ1-42) and Cu2+ were used as a vitro models of Alzheimer's disease(AD). Method:Aβ 1-42 (20 μmol·L-1) was reacted with different concentrations of copper sulfate (CuSO4,20,40 μmol·L-1), and then the thioflavine T (ThT) staining method was used to detect the Aβ aggregation state. The Aβ aggregation status was also detected by ThT staining in the Aβ1-42-Cu2+ group(20+20 μmol·L-1), and Danggui Shaoyaosan groups(1.6,3.2,6.4 mg·L-1).The SH-SY5Y cells were cultured and incubated with different concentrations of Aβ1-42(1.25,2.5,5,10,20,40 μmol·L-1) and Danggui Shaoyaosan(1.6, 3.2, 6.4,12.8 mg·L-1) for 24 h. Subsequently, SH-SY5Y cells were incubated with Aβ1-42 (20 μmol·L-1) and CuSO4(20 μmol·L-1) in the Aβ1-42-Cu2+ group, and incubated with Aβ1-42 (20 μmol·L-1), Danggui Shaoyaosan (1.6 mg·L-1) and CuSO4 (20 μmol·L-1) in Danggui Shaoyaosan group. Control group was added with the medium. After 24 h of co-action, the cell viability was detected by the methylthiazolyl tetrazolium (MTT) assay. The morphology of the cells was photographed by microscopy. The intracellular extracellular Aβ1-42 aggregation was detected by Western blot. Result:Cu2+ and Aβ1-42 bound to more and larger Aβ aggregates compared with the Aβ1-42 group. Compared with the normal group, cell viability was significantly reduced (PPβ1-42 aggregation was increased(PPβ-Cu2+ (PPβ1-42 protein (PPConclusion:Cu2+ can increase the aggregation and toxicity of Aβ; Danggui Shaoyaosan can significantly reduce the damage of SH-SY5Y cells induced by Cu2+-mediated Aβ aggregation, promote Aβ endocytosis, reduce extracellular Aβ aggregation and increase cell viability.
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Objective To use the liquid protein combined with MALDI-TOF-MS for screening the serum differential peptides markers in lung adenocarcinoma patients and to establish the lung adenocarcinoma diag-nosed prediction model for founding the potential markers for the diagnosis of lung adenocarcinoma.Methods 37 patients with lung adenocarcinoma and 33 healthy subjects and benign lung disease which were made up in control group were collected,in the two groups the age and the sex were matched.The two groups were ran-domly divided into training group(30 cases of lung adenocarcinoma,26 cases of control)and test group(7 ca-ses of lung adenocarcinoma,7 cases of control)according to 3:1.T he differential diagnosis of lung adenocarci-noma and control group was performed by liquid chip-time-of-flight mass spectrometry and software ClinPro-Tools 3.0 to establish a prediction model of lung adenocarcinoma.The diagnostic model was validated by using serum samples from the test group to assess the diagnostic efficacy of the model.Results Nine peptide peaks with significant differences(P<0.05)were obtained by ClinProTools 3.0 software analysis.The up-regulated peaks in lung adenocarcinoma(m/z)were 8 976.5,4 469.05,4 966.78,8 925.5,4 531.05,and the down-reg-ulated m/z were 3 304.44,8 594.76,3 266.82,3 195.52.According to the genetic algorithm(GA),the lung ad-enocarcinoma diagnosis and prediction model was established.The overall recognition ability of the model was 94.49%.The model was evaluated by the test group.The results showed that the sensitivity of the model was 100.0% and the specificity was 85.7%.Conclusion Among lung adenocarcinoma patients,serum benign lung disease and healthy,there are differences in the serum peptide.T he use of differential peptide peaks to estab-lish lung adenocarcinoma diagnostic prediction model for the early diagnosis of lung adenocarcinoma provides a new method.
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A silver nanowires(AgNWs) flexible electrode was prepared using polydimethylsiloxane (PDMS) as the substrate and AgNWs as the conductive layer. It is easier to change the shapes and sizes of the flexible electrode due to its excellent stretchability and foldability. A square wave stripping voltammetry (SWSV) method for the detection of trace copper in water was established using the electrode as the working electrode.The characterization of AgNWs flexible electrode showed that the spread of AgNWs was uniform and the average resistance was 1.03 Ω. The data of electrochemical analysis showed that the properties of the electrode were superior to commercialized gold electrode and silver electrode. The effects of Bi3+concentration, supporting electrolyte,pH value, enrichment potential and enrichment time were determined and optimized. We achieved the sharpest and highest peak of the SWSV curves for the detection of Cu2+in the range of-0.3-0.3 V,which means the most sensitive detection, under the following conditions such as 0.5 mg/L Bi3+,0.1 mol/L support electrolyte tartaric acid-sodium tartrate solution (pH, 4.8), 0.6 V of enrichment potential, and 600 s of enrichment time. Under such conditions, the linear detection range of Cu2+concentration was from 0.001 mg/L to 0.100 mg/L and the detection limit was 9.27×10-5mg/L. The advantages of this detection method are fast speed,high sensitivity and wide detection range. Therefore,it can not only meet the requirements for the copper ion detection but also provide a new method or experimental basis for the detection of other metal ions in water. In addition, the AgNWs flexible electrode has great potential in detections under special circumstances or instantaneous detections due to its wonderful flexibility and biocompatibility.
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Iron-doped titanium dioxide nanosheets was prepared by hydrothermal method using tetrabutyl titanate (C16H36O4Ti) and iron trifluoride (FeF3) and modified on ITO electrode.ITO/Fe : TiO2/CdS photoelectrochemical sensor was fabricated by successive ionic layer absorption and reaction(SILAR) method for determination of copper ion.The band gap of electode material was narrowed by iron doped TiO2 nanosheets,which made its absorption red-shifted and its response range of light was magnified.Based on the sensitization effect of CdS,the absorption and utilization of visible light of sensor was significantly enhanced and the photoelectric signal was amplified via reducing the recombination of electrons and holes.The sensor displayed excellent analytical performance for detection of copper ion with linear range of 0.2-4.0 μmol/L and 4.0-80.0 μmol/L and with the detection limit of 85 nmol/L.The sensor was used to detect copper ion in tap water,drinking water and Yongjiang river water with recoveries ranging from 94% to 111%.
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Objective To develop a method for determination of serumal copper ion in rabbit with implantation of copper intrauterine device.Methods At different time points after implantation,the serumal copper ion concentrations were determined by microwave digestion-inductively coupled plasma mass spectrometry(ICP-MS) using scandium(Sc) and indium(In) as internal standards to compensate sample matrix effects,and the pharmacokinetics parameters were calculated in order to reflect copper ion release and metabolic rule.Results The serumal copper ion concentrations were kept at a low and stable level.The recoveries were in the range of 98.7%-113.3%,with the relative standard deviations of less than 5.0%.Conclusion The analytical method is simple,fast,and can be used for the determination of serumal copper ion in rabbit.
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Objective To detect the transcription factors of copper ion (Cu,2+) metabolism and oxidative stress by Candida albicans knocked down different transcription factors.Methods Spot assay, growth curve were used.Results The sensitivity to Cu,2+ in Cup2Δ/Δ was increasing and the growth of Cup2Δ/Δ was inhibited in 5 mmol /L Cu,2+ medium.The results showed that Cup2Δ/Δ also increased the sensitivity to H2O2, interestingly, Cu,2+and H2O2 played a synergistic antifungal effect.The tolerance of Cup2Δ/Δ and SN250 to H2O2 induced oxidative stress was increased after BCS chelating Cu,2+.In the fluconazole, miconazole and ketoconazole susceptibility experiments, Cup2Δ/Δ did not show susceptibility to azole drugs.Conclusion Knockout transcription factor Cup2, which could increase the sensitivity to Cu,2+ and H2O2in Candida albicans.Transcription factor Cup2 might be involved in the regulation and control of Candida albicansmetabolism on Cu,2+ and oxidative stress induced by H2O2, but not involved in the regulation and control of drug resistance to azole drugs.
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A photochromic sensing platform composing of emeraldine salt of polyaniline ( ES-PANI ) and titanium dioxide nanoparticles ( TiO2 NPs) for visual detection of trace copper was developed. Under ultraviolet light irradiation, the greenish ES-PANI could be oxidized to dark blue pernigraniline salt by the photogenerated hole of excited TiO2 NPs. In the presence of Cu2+, a light yellow leucoemeraldine salt was visually observed. The overall mechanism of color change was verified to be corresponding to the different redox states of PANI regulated by Cu species during the photochromic process. By integrating the advantages of both photoelectric property and visual detection, the redox reaction-based sensing mechanism led to a good sensitivity and high selectivity in the detection of Cu2+ with the detection limit of 0. 4 μmol/L. Besides the naked eye, two color recognition methods including reading mean green intensities in Photoshop and recording ultraviolet absorbance in microplate reader were also studied. This method was successfully applied to Cu2+ detection in human hair with satisfactory recoveries. More significantly, this sensing platform was really simple, low-cost and able to detect an array of analytes within several minutes without requiring sophisticated equipment. This photoelectron-regulated colorimetric strategy provided a novel concept for the design of visual sensing platform, and could develop the portable test kits for rapid detection in clinical diagnosis.