基于ANEP染料荧光光谱迁移的单波长心脏光学标测系统

近几年来,光学标测技术已经成为心脏电生理研究中一种非常重要的手段。它利用对嵌在细胞膜上的电压敏感染料随着膜电位变化而产生的荧光光谱迁移进行成像,来进行心律失常与电击除颤等电生理研究。文章测量了常用的电压敏感染料di-4-ANEPPS的荧光光谱,并根据该染料的光谱迁移,设计了一套包括一个通用CCD相机的单波长光学标测系统,可以达到较高的时空分辨率。记录心肌细胞中的电兴奋传导过程,从而可以为今后国内心律失常作用机制的研究工作提供一个有力的工具。

Solid-phase extraction and separation of indium with P_(2)O_(4)-UiO-66-MOFs (di-2-ethylhexyl phosphoric acid-UiO-66-metal-organic frameworks)

Compared with the traditional liquid–liquid extraction method,solid-phase extraction agents are of great significance for the recovery of indium metal due to their convenience,free of organic solvents,and fully exposed activity.In this study,P_(2)O_(4)(di-2-ethylhexyl phosphoric acid)was chemically modified by using UiO-66 to form the solid-phase extraction agent P_(2)O_(4)-UiO-66-MOFs(di-2-ethylhexyl phosphoric acid-UiO-66-metal-organic frameworks)to adsorb In(Ⅲ).The results show that the Zr of UiO-66 bonds with the P-OH of P_(2)O_(4) to form a composite P_(2)O_(4)-UiO-66-MOF,which was confirmed by X-ray photoelectron spectroscopy(XPS)and Fourier transform infrared spectroscopy(FT-IR).The adsorption process of indium on P_(2)O_(4)-UiO-66-MOFs followed pseudo first-order kinetics,and the adsorption isotherms fit the Langmuir adsorption isotherm model.The adsorption capabilities can reach 192.8 mg/g.After five consecutive cycles of adsorption-desorption-regeneration,the indium adsorption capacity by P_(2)O_(4)-UiO-66-MOFs remained above 99%.The adsorption mechanism analysis showed that the P=O and P-OH of P_(2)O_(4) molecules coated on the surface of P_(2)O_(4)-UiO-66-MOFs participated in the adsorption reaction of indium.In this paper,the extractant P_(2)O_(4) was modified into solid P_(2)O_(4)-UiO-66-MOFs for the first time.This work provides a new idea for the development of solid-phase extractants for the recovery of indium.

Distribution of Prestin on Outer Hair Cell Basolateral Surface

Prestin has been identified as a motor protein responsible for outer hair cell (OHC) electromotility and is expressed on the OHC surface. Previous studies revealed that OHC electromotility and its associated nonlinear capacitance were mainly located at the OHC lateral wall and absent at the apical cuticular plate and the basal nucleus region. Immunofluorescent staining for prestin also failed to demonstrate prestin expression at the OHC basal ends in whole-mount preparation of the organ of Corti. However, there lacks a definitive demonstration of the pattern of prestin distribution. The OHC lateral wall has a trilaminate organization and is composed of the plasma membrane, cortical lattice, and subsurface cisternae. In this study, the location of prestin proteins in dissociated OHCs was examined using immunofluorescent staining and confocal microscopy. We found that prestin was uniformly expressed on the basolateral surface, including the basal pole. No staining was seen on the cuticular plate and stereocilia. When co-stained with a membrane marker di-8-ANEPPS, prestin-labeling was found to be in the outer layer of the OHC lateral wall. After separating the plasma membrane from the underlying subsurface cisternae using a hypotonic extracellular solution, prestin-labeling was found to be in the plasma membrane, not the subsurface cisternae. The data show that prestin is expressed in the plasma membrane on the entire OHC basolateral surface.

Membrane lipid raft organization during cotton fiber development

Background:Cotton fiber is a single-celled seed trichome that originates from the ovule epidermis.It is an excellent model for studying cell elongation.Along with the elongation of cotton fiber cell,the plasma membrane is also extremely expanded.Despite progress in understanding cotton fiber cell elongation,knowledge regarding the relationship of plasma membrane in cotton fiber cell development remains elusive.Methods:The plasma membrane of cotton fiber cells was marked with a low toxic fluorescent dye,di-4-ANEPPDHQ,at different stages of development.Fluorescence images were obtained using a confocal laser scanning microscopy.Subsequently,we investigated the relationship between lipid raft activity and cotton fiber development by calculating generalized polarization(GP values)and dual-channel ratio imaging.Results:We demonstrated that the optimum dyeing conditions were treatment with 3μmol·L-1 di-4-ANEPPDHQ for 5 min at room temperature,and the optimal fluorescence images were obtained with 488 nm excitation and500–580 nm and 620–720 nm dual channel emission.First,we examined lipid raft organization in the course of fiber development.The GP values were high in the fiber elongation stage(5–10 DPA,days past anthesis)and relatively low in the initial(0 DPA),secondary cell wall synthesis(20 DPA),and stable synthesis(30 DPA)stages.The GP value peaked in the 10 DPA fiber,and the value in 30 DPA fiber was the lowest.Furthermore,we examined the differences in lipid raft activity in fiber cells between the short fiber cotton mutant,Li-1,and its wild-type.The GP values of the Li-1 mutant fiber were lower than those of the wild type fiber at the elongation stage,and the GP values of 10 DPA fibers were lower than those of 5 DPA fibers in the Li-1 mutant.Conclusions:We established a system for examining membrane lipid raft activity in cotton fiber cells.We verified that lipid raft activity exhibited a low-high-low change regularity during the development of cotton fiber cell,and the pattern was disrupted in the short lint fiber Li-1 mutant,suggesting that membrane lipid order and lipid raft activity are closely linked to fiber cell development.

Two New Copper Complexes by H_4AQTC(Anthraquinone-1,4,5,8-tetracarboxylic Acid):Syntheses,Structures and Properties

Two new complexes[Cu(AQTC)_(0.5)(H_(2)O)_(3)]·3H_(2)O}_(n) (1,H_(4)AQTC=anthraquinone-1,4,5,8-tetracarboxylic acid) and Cu[(Py)_(2)C(OH)_(2)]_(2)(H_(2)AQTC)·2H_(2)O (2,(Py)_(2)CO=di-2-pyridyl ketone) have been prepared and characterized by elemental analyses and IR spectroscopy.X-ray crystallographic studies show that complex 1crystallizes in monoclinic space group C2/m and complex 2 in monoclinic space group P2_1/c.Complex 1 features a1D chain structure by carboxyl oxygen atoms.Complex 2 displays a mononuclear structure and anions and cations are separated.What's interesting is that the ligand of H_(4)AQTC with eight carboxyl oxygen atoms and two quinone oxygen atoms does not directly coordinate with metals,and only exist as a counter-anion in complex 2.Three-dimensional structures of two complexes are formed by intermolecular interactions.The thermogravimetric analyses of two complexes are investigated.The luminescent properties of complex 1 are investigated as well.

工业模式微生物膜有序性的活细胞定量分析

作为一种相位敏感的荧光探针,Di-4-ANEPPDHQ可以特异性标记膜的有序相和无序相,在理论上可以对细胞膜的有序性进行定量成像。通过将Di-4-ANEPPDHQ和激光扫描共聚焦显微术相结合,对多种具有代表性的工业模式微生物进行了有序相和无序相活细胞成像,结合极性归一化数值的统计比较,最终实现对上述工业模式微生物细胞膜有序性的定量分析,为细胞膜工程提供了一种直观且快速的活细胞检测方法。