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231.
Syntheses,Structures, and Luminescent Properties of d10 Coordination Polymers with 2‐(4‐Carboxyphenyl)‐imidazo[4, 5‐f]‐1, 10‐phenanthroline and 1, 3‐Benzenedicarboxylate Derivatives 下载免费PDF全文
Jie‐Fang Fang Jing‐Xiang Cheng Shu‐Ting Huang Jing Zhang Chang‐Qiong Ni Yan‐Ju Xiong Qian Cheng Fei‐Fei Zhu Yun Li Shan‐Tang Yue 《无机化学与普通化学杂志》2015,641(15):2657-2663
Four ZnII/CdII coordination polymers (CPs) based on 2‐(4‐carboxy‐phenyl)imidazo[4, 5‐f]‐1, 10‐phenanthroline (HNCP) and different derivatives of 5‐R‐1, 3‐benzenedicarboxylate (5‐R‐1, 3‐BDC) (R = NO2, H, OH), [Zn(HNCP)(5‐NO2‐1, 3‐BDC)]n ( 1 ), [Cd(HNCP)(5‐NO2‐1, 3‐BDC)]n ( 2 ), [Zn(HNCP)(1, 3‐BDC)(H2O)2]n ( 3 ), and {[Zn(HNCP)(5‐OH‐1, 3‐BDC)(H2O) · H2O}n ( 4 ) were synthesized under hydrothermal conditions. Compounds 1 – 4 were determined by elemental analyses, IR spectroscopy, and single‐crystal and powder X‐ray diffraction. Compounds 1 and 2 are isomorphous, presenting a 4‐connected uninodal (4, 4)‐sql 2D framework with threefold interpenetration, which are further extended into the three‐dimensional (3D) supramolecular architecture through π ··· π stacking interactions between the aryl rings of 5‐NO2‐1, 3‐BDC. Compared to compound 1 , 3 is obtained by using different reaction temperatures and metal‐ligand ratios, generating a 3D framework with –ABAB– fashion via π ··· π stacking interactions. Compound 4 is a 1D chain, which is further extended into a 3D supramolecular net by hydrogen bonds and π ··· π stacking interactions. The thermogravimetric and fluorescence properties of 1 – 4 were also explored. 相似文献
232.
An Antibacterial Nonenzymatic Glucose Sensor Composed of Carbon Nanotubes Decorated with Silver Nanoparticles 下载免费PDF全文
Yingzhu Liu Shan Liu Rongsheng Chen Weiting Zhan Hongwei Ni Feng Liang 《Electroanalysis》2015,27(5):1138-1143
A glucose sensor composed of silver nanoparticles decorated carbon nanotubes (Ag‐NPs/CNTs) prepared by ion implantation is described. Ag‐NPs with size of 2–4 nm are uniformly distributed in the CNTs after ion implantation. This process provides a strong combination between Ag‐NPs and CNTs and can effectively prevent the Ag‐NPs from aggregation. A linear range of 125 µM to 10 mM towards glucose determination was obtained. The Ag‐NPs/CNTs electrode shows minimal interferences from co‐existence species such as uric acid and ascorbic acid and an antibacterial rate of 94 % towards E. coli. 相似文献
233.
Automated headspace solid‐phase microextraction and on‐fiber derivatization for the determination of clenbuterol in meat products by gas chromatography coupled to mass spectrometry 下载免费PDF全文
A method was developed for the determination of clenbuterol in meat using stable‐isotope‐dilution gas chromatography with mass spectrometry coupled with solid‐phase microextraction and on‐fiber derivatization. The samples were first homogenized with hydrochloric acid followed by protein deposition. After headspace solid‐phase microextraction and on‐fiber derivatization, the content of clenbuterol was measured with the aid of stable‐isotope dilution. The condition of solid‐phase microextraction was optimized by central composite design. The relative standard deviations, limit of detection, and recoveries for clenbuterol were 4.2–9.2%, 0.48 μg/kg, and 96–104%, respectively. The proposed method was satisfactory for analysis of real samples as compared with the Chinese standard method. 相似文献
234.
Screening of drugs of abuse and toxic compounds in human whole blood using online solid‐phase extraction and high‐performance liquid chromatography with time‐of‐flight mass spectrometry 下载免费PDF全文
Xiaomei Teng Chen Liang Rong Wang Tao Sun Yulan Rao Chunfang Ni Libo Zeng Lingjuan Xiong Yuan Li Yurong Zhang 《Journal of separation science》2015,38(1):50-59
A novel method for the screening of 151 drugs of abuse and toxic compounds in human whole blood has been developed and validated by online solid‐phase extraction with liquid chromatography coupled to time‐of‐flight mass spectrometry. Analytes were extracted and separated by using a fully automated online solid‐phase extraction liquid chromatography system with total chromatographic run time of 26 min. Time‐of‐flight mass spectrometry screening of 151 drugs of abuse and toxic compounds was performed in a full‐scan (m/z 50–800) mode using an MSE acquisition of molecular ions and fragment ions data at two collision energies (one was 6 eV and another one was in the range of 5–45 eV). The compounds were identified based on retention times and exact mass of molecular ions and fragment ions. The limit of detection ranged from 1 to 100 ng/mL and the recovery of the method ranged from 6.3 to 163.5%. This method is proved to be a valuable screening method allowing fast and specific identification of drugs in human whole blood. 相似文献
235.
Paul Tanui Martin Kullberg Ni Song Yashodhan Chivate Eriks Rozners 《Tetrahedron》2010,66(27-28):4961-4964
Amides as neutral and hydrophobic internucleoside linkages in RNA are highly interesting modifications for RNA interference. However, testing amides in siRNAs is hampered by the shortage of efficient methods to synthesize the monomeric building blocks, the nucleoside amino acid equivalents. This paper reports an efficient synthesis of protected ribonucleoside 5′-amino 3′-carboxylic acids from d-xylose in 14 steps 7% overall yield. The key features that ensure efficiency and ease of operations are chemoselective reduction of the ester and minimization of protecting group manipulation. 相似文献
236.
采用不同合成方法制备了4种组成为Ce0.5Zr0.5O2的铈锆固溶体.通过XRD,BET,H2-TPR,HREM以及SEAD等表征手段,研究了微观晶相结构对铈锆固溶体还原性能的影响规律,以及对固溶体储放氧能力的影响.分析结果表明,在同一组成下,不同制备方法得到截然不同的晶相组成,4种固溶体包含4种不同的晶相组合.通过对微观晶相结构的定量分析,发现立方相的形成对促进固溶体的还原性能起到重要作用.其中,反相微乳法制得的铈锆固溶体能够形成完整的立方相结构,在H2-TPR还原过程中耗氢量最大,表明其具有优良的可还原性及储放氧能力,适合作为TWC,POX等催化剂载体. 相似文献
237.
238.
柠檬酸镧诱导肿瘤细胞凋亡的研究 总被引:2,自引:1,他引:2
采用噻唑蓝(MTT)法检测稀土化合物柠檬酸镧在1×10-3~5 mmol·L-1浓度范围内对体外培养的人乳腺癌细胞株MCF-7、前列腺癌细胞株PC-3、肝癌细胞株HepG2和宫颈癌细胞株HeLa生长的影响.结果表明,柠檬酸镧对各种癌细胞生长的影响存在浓度依赖性,在实验浓度范围内,低浓度无明显作用特征,高浓度抑制癌细胞生长;不同肿瘤细胞对稀土的响应不同,HeLa细胞相对敏感,其IC50值为(0.16±0.08)mmol·L-1,而MCF-7细胞为(0.18±0.02)mmol·L-1,PC-3细胞为(1.55±0.45)mmol·L-1,HepG2细胞为(2.71±0.11)mmol·L-1.进一步以0.15 mmol·L-1的柠檬酸镧作用于HeLa细胞,采用Hoechst 33258荧光染色、PI单染流式细胞仪检测、Annexin V-FITC/PI双染色法观察镧对HeLa细胞的毒性作用.结果表明,柠檬酸镧作用24 h后,HeLB细胞出现明显的凋亡特征,PI染色流式细胞仪检测可见凋亡峰,细胞周期分析表明sub-G1期细胞硅著增加,G0/G1期细胞显著减少(P<0.05),Annexin V-FITC/PI双染检测细胞凋亡率为(61.65±4.60)%(P<0.05).上述结果表明柠檬酸镧能诱导癌细胞发生凋亡.以HeLa细胞最灵敏而对HepG2并不敏感,其次序为HeLa>McF-7>Pc-3>HepG2. 相似文献
239.
Zeng Y Zhang W Xu C Xiao N Huang Y Yu DY Hng HH Yan Q 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(13):4026-4030
Single-crystalline TiOF(2) nanotubes were prepared by a one-step solvothermal method. The nanotubes are rectangular in shape with a length of 2-3?μm, width of 200-300?nm, and wall thickness of 40-60?nm. The formation of TiOF(2) nanotubes is directly driven by the interaction between TiF(4) and oleic acid in octadecane to form the 1D nanorods, and this is followed by a mass diffusion process to form the hollow structures. The synthesis approach can be extended to grow TiOF(2) nanoparticles and nanorods. Compared with TiO(2), which is the more commonly considered anode material in lithium-ion batteries, TiOF(2) has the advantages of a lower Li-intercalation voltage (e.g., to help increase the total voltage of the battery cell) and higher specific capacities. The TiOF(2) nanotubes showed good Li-storage properties with high specific capacities, stable cyclabilities, and good rate capabilities. 相似文献
240.
A selective and sensitive high-performance liquid chromatography-electrospray ionization mass spectrometry (MS) for the determination of nisoldipine in human plasma is first presented. With nimodipine as the internal standard, nisoldipine is extracted from plasma with ethyl acetate. The organic layer is evaporated and the residue is resuspended in the mobile phase of methanol-water (80:20, v/v). An aliquot of 40 microL is chromatographically analyzed on an Agilent ODS C18 reversed-phase column (5 microm, 250- x 4.6-mm i.d.) by means of selected-ion monitoring mode MS. The calibration curve of nisoldipine in plasma exhibits a linear range from 0.5 to 20.0 ng/mL with a correlation coefficient of 0.9995. The limit of detection is 0.2 ng/mL. The within- and between-day variations (relative standard deviation) are less than 9.28% and 11.13% (n = 5), respectively. The developed method is validated through successful use for the analysis of nisoldipine contained in biological fluids resulting from a phase-I human pharmacokinetic study. 相似文献