Na+₋sensing quantum dots for cell-based screening of intracellular Na+ concentrations ([Na+]i)

We have developed a Na-quantum dot (QD) nanosensor for [Na⁺]i measurements. Using this Na-QD, we determined the dynamic physiological responses of [Na⁺]i in nonexcitable human HEK-293F cells and excitable primary rat cardiac myocytes by pharmacologically manipulating the membrane permeability to Na⁺, the Na-K-2Cl cotransporter, and the Na⁺/H⁺ antiporter. These data suggest that the mechanisms of [Na⁺]i homeostasis can now be elucidated with this novel Na-QD nanosensor. This could have a broad impact on Na⁺ channel drug discovery.     

Synthesis of 4,4-dialkoxy-3-piperidinols. Application to the synthesis of γ-acetate dehydropipecolinonitrile

The synthesis of 4,4-dialkoxy-3-piperidinols 7 was carried out by the α-bromination of piperidin-4-one 5 with N-bromosuccinimide in acetic acid and alkoxide ion-mediated α,α-dialkoxyhydroxylation. Under acidic condition, trimethyl orthoformate-mediated reaction of compound 7a yielded aminodienylester 8 in the presence of Ph₃PCHCO₂Et. The γ-acetate dehydropipecolinonitrile 4 was also synthesized via boron trifluoride etherate-promoted addition of compound 8 with trimethylsilyl cyanide and N-bromosuccinimide and selective hydrogenation.     

Facile and quick synthesis of 1-monosubstituted aryl 1,2,3-triazoles: a copper-free [3+2] cycloaddition

An efficient copper-free synthesis of 1-monosubstituted aryl 1,2,3-triazoles from sodium acetylide and aryl azides was developed, which was found suitable for various aryl azides and completed within 15 min at room temperature with moderate to excellent yields.     

First nucleophilic addition of acetylide to 1,3-diketonate anions: reaction of 1-aryl-4,4,4-trifluorobutane-1,3-diones with sodium acetylide

The nucleophilic addition of sodium acetylide to 1,3-diketonates derived from 1-aryl-4,4,4-trifluorobutane-1,3-diones is reported. Tertiary 1,4-alkynediols containing CF₃ and aroylmethyl groups are synthesized. 5,5′-Diaryl-3,3′-bis(trifluoromethyl)-2,2′-bifurans are prepared via a novel double cyclization of these alkynediols.     

On-line coupling of gel electrophoresis and inductively coupled plasma-mass spectrometry

The on-line coupling of gel electrophoresis with inductively coupled plasma-mass spectrometry (GE-ICP-MS) is a powerful tool for simultaneous separation, detection and quantification of bio-molecules, and has been applied to the determination of phosphorus in DNA, phosphoproteins, and phosphopeptides, gold in nano-particles, iron in metalloproteins, and iodine in aerosols, and cisplatin-oligonucleotide interactions. However, since the first report in 2005, relatively few papers have been published, perhaps reflecting the lack of familiarity with the benefits of this promising methodology. So, here for the first time, we critically review the applications of GE-ICP-MS, and explore the advantages and the limitations of the technique for various applications. Such scrutiny may be useful in not only the development of the technique but also highlighting its potential in proteomics, genomics and metallomics.     

油酸钠微乳液体系中镧的萃取

研究了油酸钠、正戊醇、正庚烷和氯化钠水溶液组成的微乳液对镧的萃取行为及机理,分别考察了萃取时间、水乳比、油酸钠浓度、戊醇浓度、水相pH值及无机盐浓度对萃取过程的影响,通过实验得到油酸钠微乳液体系非常稳定,在不加萃取剂的条件下对La3+有非常好的萃取效果,当油酸钠和正戊醇质量分数分别为6%和32%,水乳比R=7,pH值在3.5~7范围内,萃取率均高于99.5%。     

CdS纳米材料共振瑞利散射测定氧氟沙星的研究

在表面活性剂十二烷基磺酸钠SDS存在下,硫化镉能与氧氟沙星借静电引力及疏水作用力结合,形成粒径较大的聚集体.这种聚集体的形成导致硫化镉共振散射RRS强度显著增强,最大散射峰位于365nm.在适当条件下,散射强度△Ⅰ与氧氟沙星浓度成正比,据此提出了硫化镉-氧氟沙星-SDS体系测定氧氟沙星的新方法.方法的线性范围为4.0×...     

以无机硫为原料制备硫化铅量子点及其表征

根据高温下快速成核低温下慢速生长的量子点制备原理, 采用胶体化学的方法成功制备了不同粒径的硫化铅半导体量子点. 这种方法的特点是以无味和低毒的硫化钠作为制备硫化铅量子点硫的前驱物, 因此这是一种量子点的绿色化学合成方法. 油酸作为稳定剂控制硫化铅的粒径. 采用X射线衍射和高分辨透射电镜表征了量子点的晶体结构、形貌和粒径, 采用可见-近红外吸收光谱研究了硫化铅量子点的量子尺寸效应. 通过降低油酸的添加量可以促进量子点的生长, 得到较大粒径量子点. 并探讨了量子点的生长机理.     

超临界二氧化碳微乳液增溶多元醇特性

用2.5%、5.0%和7.5% (w)的1,3-丙二醇(1,3-PDO)稀水溶液为模型物质, 以超临界二氧化碳为连续相, 以琥珀酸二酯磺酸钠(AOT)为表面活性剂, 乙醇为助剂, 在压力为6.9-10.3 MPa的范围内, 温度为30-50 °C时, 分别对三种AOT浓度下的四元体系AOT/CO₂/乙醇/水和五元体系AOT/CO₂/乙醇/1,3-PDO/水的热力学行为进行了实验研究. 实验结果证明: 通过合理调控系统的操作条件, 可以形成热力学稳定的超临界二氧化碳微乳液, 并能实现选择性增溶1,3-丙二醇. 该结果可为指导工业生产提供依据.     

Thermodynamic representation of the NaCl + Na2SO4 + H2O system with electrolyte NRTL model

A comprehensive thermodynamic model based on the electrolyte NRTL (eNRTL) activity coefficient equation is developed for the NaCl + H₂O binary, the Na₂SO₄ + H₂O binary and the NaCl + Na₂SO₄ + H₂O ternary. The NRTL binary parameters for pairs H₂O-(Na⁺, Cl⁻) and H₂O-(Na⁺, SO₄²⁻), and the aqueous phase infinite dilution heat capacity parameters for ions Cl⁻ and SO₄²⁻ are regressed from fitting experimental data on mean ionic activity coefficient, heat capacity, liquid enthalpy and dissolution enthalpy for the NaCl + H₂O binary and the Na₂SO₄ + H₂O binary with electrolyte concentrations up to saturation and temperature up to 473.15 K. The Gibbs energy of formation, enthalpy of formation and heat capacity parameters for solids NaCl_(s), NaCl·2H₂O_(s), Na₂SO_4(s) and Na₂SO₄·10H₂O_(s) are obtained by fitting experimental data on solubilities of NaCl and Na₂SO₄ in water. The NRTL binary parameters for the (Na⁺, Cl⁻)-(Na⁺, SO₄²⁻) pair are regressed from fitting experimental data on dissolution enthalpies and solubilities for the NaCl + Na₂SO₄ + H₂O ternary.