A novel 3D mammalian cell perfusion-culture system in microfluidic channels

Mammalian cells cultured on 2D surfaces in microfluidic channels are increasingly used in drug development and biological research applications. These systems would have more biological or clinical relevance if the cells exhibit 3D phenotypes similar to the cells in vivo. We have developed a microfluidic channel based system that allows cells to be perfusion-cultured in 3D by supporting them with adequate 3D cell-cell and cell-matrix interactions. The maximal cell-cell interaction was achieved by perfusion-seeding cells through an array of micropillars; and 3D cell-matrix interactions were achieved by a polyelectrolyte complex coacervation process to form a thin layer of matrix conforming to the 3D cell shapes. Carcinoma cell lines (HepG2, MCF7), primary differentiated (hepatocytes) and primary progenitor cells (bone marrow mesenchymal stem cells) were perfusion-cultured for 72 hours to 1 week in the microfluidic channel, which preserved their 3D cyto-architecture and cell-specific functions or differentiation competence. This transparent 3D microfluidic channel-based cell culture system also allows direct optical monitoring of cellular events for a wide range of applications.     

Synthesis and size control of monodisperse copper nanoparticles by polyol method

We describe herein the synthesis of metallic copper nanoparticles in the presence of poly(vinylpyrrolidone), employed as a protecting agent, via a polyol method in ambient atmosphere. The obtained copper particles were confirmed by XRD to be crystalline copper with a face-centered cubic (fcc) structure. We observed monodisperse spherical copper nanoparticles with a diameter range 45+/-8 nm. The particle size and its distribution are controlled by varying the synthesis parameters such as the reducing agent concentration, reaction temperature, and precursor injection rate. The precursor injection rate plays an important role in controlling the size of the copper nanoparticles. On the basis of XPS and HRTEM results, we demonstrate that the surface of the copper is surrounded by amorphous CuO and that poly(vinylpyrrolidone) is chemisorbed on the copper surface.     

1H and 13C NMR assignments for two new angular furanocoumarin glycosides from Peucedanum praeruptorum

Two novel angular-type furanocoumarin glycosides, peucedanoside A (1) and peucedanoside B (2), along with a known compound apterin (3), were isolated from the roots of Peucedanum praeruptorum Dunn. Their chemical structures were determined by MS, NMR spectroscopy and chemical analysis. Complete assignments of the 1H and 13C NMR spectroscopic data were achieved by 1D and 2D NMR experiments including DEPT, HSQC, HMBC and ROESY.     

Dy(ClO_4)_3·3H_2O-18C6-CH_3CN体系的相平衡及其固体配合物的合成

近年来稀土冠醚配合物的研究受到广泛重视,但稀土高氯酸盐冠醚配合物的研究报道较少。高氯酸镝与冠醚18C6的配合物尚未见报道。我们利用半微量相平衡方法研究了Dy(ClO_4)_3·3H_2O-18C6-CH_3CN三元体系在15℃时的溶解度。同时制得了固态配合物,用化学分析及物理化学方法研究了配合物的组成和性质。     

甲基丙烯酸3-磺酸钾丙酯-苯乙烯共聚物与N,N,N-三甲基十六烷基溴化铵相互作用研究

两亲分子由于具有自组装性质,如表面活性剂分子自组装形成胶束,囊泡,天然的磷脂分子自组装形成脂质体,继而参于生物膜的形成,这是大家所熟悉的．高分子两亲分子尤其是两亲性两嵌段高分子具有自组装性质,并形成规整性好的聚集体［１～３］．聚电介质 表面活性剂体系...     

高效液相色谱法测定萨拉沙星

采用高效液相色谱法测定了萨拉沙星。色谱柱为μ－BondapakTMC18柱（3．9mm×300mm）,流动相为V（乙腈）：V（甲醇）：V（2mmol／L磷酸,用三乙胺调pH3．5）＝30：5：65,用二极管阵列检测器检测,检测波长278nm,得到了满意的分离效果。     

Synthesis and Characterization of Chiral Binuclear Organolanthanide and Yttrium Alkoxides Containing Cyclopentadienyl Ligand

Recently,variousdimericlanthanidealkoxidesofthetype[(Ln(p-oR)(Cp)2}2]havebeenpreparedbytreatmentofthechlorocomplexeswithsodiumalkoxideslorprotonationofLn(Cp)3withstoichiometricamountsofalcohols2.Butthechiralorganolanthanidepolymericalkoxidescontainingcyclopentadienylgroupsandopticallypurediolligandshavenotbeenreporteduptonow3.Furthermore,themethodofprotonationisusuallyappliedinnon-coordinatingsolventssuchasheptane,hexane,benzeneandtoluene.Inthispaper,wewishtoreportthefirstsynthesisofchiralcy…     

甲基丙烯酸3—磺酸钾丙酯—苯乙烯共聚物与N,N,N—三甲基十六烷基化铵相 …

两亲分子由于具有自组装性质,如表面活性剂分子自组装形成胶束,囊泡,天然的磷脂分子自组装形成脂质体,继而参于生物膜的形成,这是大家所熟悉的．高分子两亲分子尤其是两亲性两嵌段高分子具有自组装性质,并形成规整性好的聚集体［１～３］．聚电介质表面活性剂体系...     

Synthesis and Infrared Multi‐band Absorption Properties of Core‐shell NaYF4:Yb3+, Er3+@SiO2 Nanoparticles

Due to the unique size effects, nanomaterials in infrared absorption have attracted much attention for their strong absorption in the infrared region. To achieve the infrared multi‐band absorption, we propose to synthesize a core‐shell structure nanomaterial consisting of NaYF₄:Yb³⁺, Er³⁺ core and a layer of SiO₂ as shell. A series of NaYF₄:Yb³⁺, Er³⁺ nanocrystals were synthesized through hydrothermal method by adjusting the ratio of citric acid(CA)‐to‐NaOH, and the effects of CA concentration, and NaOH concentration were studied in detail. NaYF₄:Yb³⁺, Er³⁺@SiO₂ nanoparticles were synthesized by sol‐gel method using TEOS as silica source. The results show that the core‐shell NaYF₄:Yb³⁺, Er³⁺@SiO₂ nanoparticles were successfully synthesized. Up‐conversion spectra of these nanoparticles were recorded with 980 nm laser excitation under room temperature. There are no changes of the emission centers of nanoparticles before or after silica coating, but the emission intensities of nanoparticles after silica coating are weakened. Furthermore, the property of infrared multi‐band absorption was tested through ultraviolet‐visible‐near infrared spectrophotometer and infrared absorption spectra. The results illustrate that the multi‐band infrared absorption nanomaterial was successfully synthesized.