摘要：
<![CDATA[<ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0005" xml:lang="en" view="all" class="author"><ce:section-title id="st0005">Abstract</ce:section-title><ce:abstract-sec id="as0005" view="all"><ce:simple-para id="sp0050" view="all">We for the first time confirmed that the low concentrations of Ag(I) could induce a silver specific aptamer probe (SAP) from a random coil sequence form to G-quadruplex structure. Thereby, a novel highly sensitive fluorescence strategy for silver(I) assay was established. The designed multifunctional SAP could act as a recognition element for Ag(I) and a signal reporter. The use of such a SAP can ultrasensitively and selectively detect Ag(I), giving a detection limit down to 0.64nM. This is much lower than those reported by related literatures. This strategy has been applied successfully for the detection of Ag(I) in real samples, further proving its reliability. Taken together, the designed SAP is not only a useful recognition and signal probe for silver, but also gives a platform to study the interaction of monovalent cations with DNA.</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0010" class="graphical" xml:lang="en" view="all"><ce:section-title id="st0010">Graphical Abstract</ce:section-title><ce:abstract-sec id="as0010" view="all"><ce:simple-para id="sp0055" view="all">The presence of Ag<ce:sup loc="post">+</ce:sup>leads to the conformational change of a silver specific aptamer probe from a random coil sequence to a G-quadruplex structure. This results in a quenching in the fluorescence, which was proportional to the concentrations of Ag<ce:sup loc="post">+</ce:sup>.</ce:simple-para><ce:simple-para>Display Omitted</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.co
摘要：
The coordination reaction of thorium (IV) with a ditopic bidentate ligand to form supramolecular polymer was studied by resonance light scattering (RLS) spectra, second-order scattering (SOS) spectra and frequency-doubling scattering (FDS) spectra, respectively. The ditopic bidentate ligand is isophthalaldehyde-tetrapyrrole (IPTP). It was synthesized through a condensation reaction of isophthalaldehyde with pyrrole. The formation of supramolecular polymer results in remarkable intensity enhancements of the three light scattering signals. The maximum scattering wavelengths of RLS, FDS and SOS were 290, 568 and 340 nm, respectively. The reaction was used to establish new light scattering methods for the determination of thorium (IV) by using IPTP as probe. Under optimum conditions, the intensity enhancements of RLS, SOS and FDS were directly proportional to the concentration of thorium (IV) in the ranges of 0.01 to 1.2 mu g mL(-1), 0.05 to 1.2 mu g mL(-1) and 0.05 to 1.2 mu g mL(-1), respectively. The detection limits were 0.003 mu g mL(-1), 0.012 mu g mL(-1) and 0.021 mu g mL(-1), respectively. The methods were suitable for analyzing thorium (IV) in actual samples. The results show acceptable recoveries and precision compared with a reference method. (C) 2017 Elsevier B.V. All rights reserved.
作者机构：
[Feng, Shaolong; Wang, Wuxiang; Deng, Ziyong; Zhou, Furong; Liao, Fen] Univ South China, Sch Publ Hlth, Hengyang 421001, Peoples R China.;[Wang, Wuxiang] Univ South China, Lib, Hengyang 421001, Peoples R China.;[Feng, Yuqin] Jilin Univ, Coll Mat Sci & Engn, Changchun 130022, Peoples R China.;[Wang, Xinming] Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Organ Geochem, Guangzhou 510640, Guangdong, Peoples R China.
通讯机构：
[Feng, Shaolong] U;[Wang, Xinming] C;Univ South China, Sch Publ Hlth, Hengyang 421001, Peoples R China.;Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Organ Geochem, Guangzhou 510640, Guangdong, Peoples R China.
关键词：
Fine particulate matter (PM2.5);Endothelial cell (EC);Apoptosis;p53;Guangzhou
摘要：
Exposure to airborne fine particulate matter (PM2.5) is associated with cardiovascular diseases (CVDs). Nevertheless, a comprehensive understanding of the underlying biological mechanisms by which PM2.5 exposure induces or aggravates CVD5 remain insufficiently clear. In the present study, the flow cytometry was employed to investigate the apoptosis of human umbilical vein endothelial cells (HUVECs) induced by PM2.5 in culture. The underlying apoptotic pathway was also studied through the determination of the protein expression and activation of p53, Bax, Bcl-2, caspases-9, -7, -3, and PARP by western blot. The results showed that PM2.5 could significantly induce the apoptosis of HUVECs at the tested concentrations (0.2,1, 5, 25 mu g mL(-1)), compared with the negative control (p < 0.05, p < 0.01). The apoptotic rate of HUVECs increased with the elevating levels of PM2.5 exposure, showing a clear dose-effect relationship. Moreover, the increasing phosphorylation of p53, decreasing ratio of Bcl-2/Bax, and enhancing activation of the downstream proteins caspase-9, -7, -3 and PARP, were also observed with the increasing concentrations of PM2.5 administration in the western blot, indicating that the intracellular approach of apoptosis, the p53-Bax-caspases pathway, is the major way of PM2.5-induced apoptosis in HUVECs. In conclusion, these results suggested that induction of EC apoptosis is an important mechanism by which ambient PM2.5 exposure poses adverse effects on the cardiovascular system. (C) 2017 Elsevier Ltd. All rights reserved.
作者机构：
[Zhang, Peng; Chai, Zhifang; Ma, Yuhui; Wang, Guohua; Zhang, Zhiyong; Zhang, Junzhe; Ding, Yayun; Xie, Changjian; He, Xiao; Luo, Wenhe] Chinese Acad Sci, Inst High Energy Phys, Key Lab Biomed Effects Nanomat & Nanosafety, Beijing 100049, Peoples R China.;[Zhang, Zhaohui] Univ South China, Sch Publ Hlth, Hengyang, Hunan, Peoples R China.;[Qu, Meihua] Weifang Med Univ, Weifang 261042, Shandong, Peoples R China.;[Zhang, Jing; Chu, Shengqi] Chinese Acad Sci, Inst High Energy Phys, Beijing Synchrotron Radiat Facil, Beijing 100049, Peoples R China.;[Zhang, Zhiyong] Univ Chinese Acad Sci, Sch Phys Sci, Beijing 100049, Peoples R China.
通讯机构：
[Zhang, Zhiyong] C;Chinese Acad Sci, Inst High Energy Phys, Key Lab Biomed Effects Nanomat & Nanosafety, Beijing 100049, Peoples R China.
关键词：
CeO2 NPs;Phytotoxicity;Phosphate;Transformation;Agar medium
摘要：
Fate and toxicity of manufactured nanoparticles (NPs) in the living organisms and the environment are highly related to their transformation. In the present study, the effect of phosphate on the phytotoxicity and transformation of CeO2 NPs was investigated in an agar medium using head lettuce plants that are sensitive to Ce3+ ions. Plants were treated by CeO2 NPs with or without phosphate for 10 days. Results suggest that the treatments of P deficiency (P(-)) and CeO2 NPs (P(+)&Ce) could separately induce significant inhibition on the growth of lettuce seedlings and cause oxidative stress, but the inhibition was the most serious when the two conditions were combined (P(-)&Ce). In the absence of phosphate, more CeO2 NPs were transformed to Ce(III) in the roots and more Ce3+ ions were translocated to the shoots, which induced higher toxicity to head lettuce. Phosphates could alleviate the phytotoxic effect of CeO2 NPs through the precipitation of dissociated Ce3+ ions. Considering the wide existence of phosphate in the environment, phosphate-related transformation may be a critical factor in evaluating the toxicity and fate of many other metal-based NPs. (C) 2017 Elsevier Ltd. All rights reserved.
摘要：
We report a highly sensitive and selective strategy for Cd(II) assay using a singly labeled multifunctional probe consisting of a Cd(II)-specific aptamer (CAP), which acted as a recognition element for Cd(II) and a signal reporter. The presence of Cd(II) can induce the conformational switching of the CAP, accompanied by a change in fluorescence intensity. Thereby, a fluorescence strategy for Cd(II) assay was established. The proposed method has a detection limit of 2.15 nM, which is much lower than the detection limits reported in related literature. This strategy involves only an aptamer probe, and the use of such a G4-based quencher avoids the dual labeling of the CAP with fluorophore/quencher units. It is obviously more convenient and economical than the other aptamer-based biosensors for Cd(II) detection. The mechanism by which Cd(II) induces the CAP to change from a random coil sequence to a stem-loop structure was studied in a series of control experiments. This strategy would be helpful in the design of a sensitive analytical platform for various target assays in environmental and biomedical fields. Graphical Abstract The presence of Cd(2+) leads to the conformational change of CAP from a random coil sequence to a stem-loop structure, resulting in a quenching in the fluorescence.
摘要：
With the development of science and technology, electronic learning has played a more and more important role in school teaching while the course resource platform of higher vocational colleges for nursing develops slowly. This paper analyzes theories of course resource platform from home and abroad, designing a virtual nursing course resource platform. This platform is divided into three modules-nursing teaching, database design and function, combining with data interaction, synchronization, analysis and processing to advance development of the platform. This paper also states problems in detail, like data and software update and gives a reference to the development of Internet teaching resource through the design of this platform.
期刊：
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY,2016年169:208-215 ISSN：1386-1425
通讯作者：
Li, Guirong
作者机构：
[Han, Qian; Li, Guirong; Li, Jiekang] Univ South China, Coll Publ Hlth, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Li, Guirong] U;Univ South China, Coll Publ Hlth, Hengyang 421001, Hunan, Peoples R China.
关键词：
Uranyl;[UO22+-salophen] complex;Photo-catalytic resonance fluorescence method;Dual cloud point extraction
摘要：
In this paper, two kinds of salophens (Sal) with different solubilities, Sal1 and Sal2, have been respectively synthesized, and they all can combine with uranyl to form stable complexes: [UO22+-Sal1] and [UO22+-Sal2]. Among them, [UO22+-Sal1] was used as ligand to extract uranium in complex samples by dual cloud point extraction (dCPE), and [UO22+-Sal2] was used as catalyst for the determination of uranium by photocatalytic resonance fluorescence (RF) method. The photocatalytic characteristic of [UO22+-Sal2] on the oxidized pyronine Y (PRY) by potassium bromate which leads to the decrease of RF intensity of PRY were studied. The reduced value of RF intensity of reaction system (Delta F) is in proportional to the concentration of uranium (c), and a novel photo-catalytic RF method was developed for the determination of trace uranium (VI) after dCPE. The combination of photo catalytic RF techniques and dCPE procedure endows the presented methods with enhanced sensitivity and selectivity. Under optimal conditions, the linear calibration curves range for 0.067 to 6.57 ng mL(-1), the linear regression equation was Delta F = 438.0 c (ng mL(-1)) + 175.6 with the correlation coefficient r = 0.9981. The limit of detection was 0.066 ng mL(-1). The proposed method was successfully applied for the separation and determination of uranium in real samples with the recoveries of 95.0-103.5%. The mechanisms of the indicator reaction and dCPE are discussed. (C) 2016 Elsevier B.V. All rights reserved.
摘要：
With rapid development of novel nanomaterials (NMs), the state of the art technologies with high efficiency and high-throughput characteristics had been applied for nanosafety evaluation. High-content screening (HCS), a cell-based multi-parametric image analysis technique, was adopted in the evaluation of eight different NMs in this study. A set of different endpoints including reactive oxygen species (ROS) production, Ca2+ transient, mitochondrial membrane potential (MMP) and cellular pH levels were checked in human bronchial epithelial (16HBE) cells after incubating with NMs for 24 hours. All NMs induced significant increase of intracellular ROS levels in 16HBE cells, although the decrease of cell viability was only found in Ag and ZnO NMs-treated cells. MMP level had a dose-response decrease in Ag, ZnO and CeO2 NMs-treated cells, while showed a significant increase in TiO2 NMs-treated cells. All tested NMs showed significant up-regulation of cellular lysosomal pH levels. However, none of NMs caused significant changes in cellular Ca2+ level at 24-hour time point. HCS allows for efficient and reliable screening of multiple responses of cells simultaneously within one screen test, which can avoid the problematic interpretation of investigations when carried on a single toxicological endpoint. Therefore, the present data provide insight and inspiration that HCS is an effective and powerful method for image-based assessments with a broad set of biological endpoints in toxicity evaluation of nanomaterials.
摘要：
A novel dual-channel strategy for the detection of metallothioneins (MTs) and Hg2+ has been developed based on a mercury-mediated aptamer beacon (MAB) using thymidine-mercury-thymidine complex as a quencher for the first time. In the presence of Hg2+, the T-rich oligonucleotide with a 6-carboxyfluorescein (TRO-FAM) can form an aptamer beacon via the formation of T-Hg2+-T base pairs, which results in a fluorescence quenching of the sensing system owing to the fluorescence resonance energy transfer (FRET) from the fluorophore of FAM to the terminated T-Hg2+-T base pair. The addition of MTs into this solution leads to the disruption of the T-Hg2+-T complex, resulting in an increase of the fluorescent signal of the system. In the optimizing condition, Delta F was directly proportional to the concentrations ranging from 5.63 nM to 0.275 mu M for MTs, and 14.2 nM to 0.30 mu M for Hg2+ with the detection limits of 1.69 nM and 4.28 nM, respectively. The proposed dual-channel method avoids the label steps of a quencher in common molecular beacon strategies, without tedious procedure or the requirement of sophisticated equipment, and is rapid, inexpensive and sensitive. (C) 2015 Elsevier B.V. All rights reserved.
