双绞铝丝纳秒电爆炸实验研究

在快前沿放电装置(约2 k A,12 ns)上对四种绞合波长(λt=0.37,0.5,0.75,1.0 mm)的双绞铝丝开展了纳秒电爆炸实验研究.实验结果表明,特定绞合波长会对能量沉积、膨胀过程、光辐射产生显著影响,当绞合波长为0.5 mm时,能量沉积为原子化焓的3.2倍,而其他三种绞合波长能量沉积变化不大,约为原子化焓的1.8倍;绞合波长为0.5 mm时膨胀速度达3.8×103m/s,光辐射相对强度也最高,在膨胀过程中较好地保持了初始结构,在t=246ns时,形成了密度约为1019cm-3,直径约为1.6 mm的中性原子柱,并且在表面形成了波长约为0.5 mm,幅值约为0.3 mm的周期性结构.     

Development of a double-layer microfluidic chip with flow medium for chemotherapy resistance analysis of lung cancer

Integration and miniaturization are main advantages of microchip-based systems. Vertical integration of the multiple operations within a multiple-layer chip is expected to satisfy the urgent demand for high-throughput and large-scale applications. This study aimed at establishing a double-layer chip to integrate the operations including the cell culture, the identification of the protein and the detection of the cell viability onto a platform systematically and supplied with flow fresh medium continuously via a syringe pump to mimic the microenvironment in vivo. With this device, human non-small cell lung cancer cell line (SPCA-1) was cultured well; the expression and the activity of multidrug resistance-associated protein (MRP1) were detected by immunofluorescence assay for the cells pretreated with or without MK-571, a known inhibitor of MRP1; apoptosis percentages were assayed for the cells after being treated by the anticancer drug etoposide (VP-16). The results demonstrated that the function of the MRP1 was inhibited by MK-571, and the percentage of apoptotic for the cells pretreated with MK-571 was higher than that of the control (38.2±2.5% versus 12.3±0.85%, p<0.005). All these indicated that the new device could provide a suitable condition for cell culture and functional analysis in biomedical research, and MK-571 is an effective inhibitor of MRP1 associated with the viability of SPCA-1 cell line treated by VP-16.     

Existence and Stability of Positive Solutions for an Elliptic Cooperative System

By discussing the properties of a linear cooperative system, the necessary and sufficient conditions for the existence of positive solutions of an elliptic cooperative system in terms of the principal eigenvalue of the associated linear system are established, and some local stability results for the positive solutions are also obtained.     

Wavefront measurement with a phase-shifting lateral-shearing Sagnac interferometer operating in broadband light

A phase-stepping lateral shearing Sagnac interferometer for wavefront measurement is described. Phase shifting is implemented using a polarisation modulator operating on the wavelength independent Pancharatnam's phase allowing accurate measurement of phase maps even with broadband light. We demonstrate the interferometer by measuring a range of different wavefront shapes using both laser and white light.     

一类未搅拌恒化器中食物网的共存态

本文讨论了一类在单种营养物输入的未搅拌恒化器中的简单食物网模型,该模型除了营养物以外,还包含有一个捕食者种群和两个竞争的食饵种群.应用Dancer不动点指数和度理论的知识,给出了该系统共存态存在的充分必要条件.     

Existence and uniqueness of coexistence states for an elliptic system coupled in the linear part

In this paper, we discuss the existence, uniqueness and stability of coexistence states for an elliptic system coupled in the linear part. The linear part of this system is co-operative. Our approaches are based on the maximum principle and some properties of linear cooperative system.     

Synthesis,crystal structures,antiproliferative activities and reverse docking studies of eight novel Schiff bases derived from benzil

Eight novel Schiff bases derived from benzil dihydrazone ( BDH ) or benzil monohydrazone ( BMH ) and four fused‐ring carbonyl compounds (3‐formylindole, FI ; 3‐acetylindole, AI ; 3‐formyl‐1‐methylindole, MFI ; 1‐formylnaphthalene, FN ) were synthesized and characterized by elemental analysis, ESI–QTOF–MS, ¹H and ¹³C NMR spectroscopy, as well as single‐crystal X‐ray diffraction. They are (1Z,2Z)‐1,2‐bis{(E)‐[(1H‐indol‐3‐yl)methylidene]hydrazinylidene}‐1,2‐diphenylethane ( BDHFI ), C₃₂H₂₄N₆, (1Z,2Z)‐1,2‐bis{(E)‐[1‐(1H‐indol‐3‐yl)ethylidene]hydrazinylidene}‐1,2‐diphenylethane ( BDHAI ), C₃₄H₂₈N₆, (1Z,2Z)‐1,2‐bis{(E)‐[(1‐methyl‐1H‐indol‐3‐yl)methylidene]hydrazinylidene}‐1,2‐diphenylethane ( BMHMFI ) acetonitrile hemisolvate, C₃₄H₂₈N₆·0.5CH₃CN, (1Z,2Z)‐1,2‐bis{(E)‐[(naphthalen‐1‐yl)methylidene]hydrazinylidene}‐1,2‐diphenylethane ( BDHFN ), C₃₆H₂₆N₄, (Z)‐2‐{(E)‐[(1H‐indol‐3‐yl)methylidene]hydrazinylidene}‐1,2‐diphenylethanone ( BMHFI ), C₂₃H₁₇N₃O, (Z)‐2‐{(E)‐[1‐(1H‐indol‐3‐yl)ethylidene]hydrazinylidene}‐1,2‐diphenylethanone ( BMHAI ), C₂₄H₁₉N₃O, (Z)‐2‐{(E)‐[(1‐methyl‐1H‐indol‐3‐yl)methylidene]hydrazinylidene}‐1,2‐diphenylethanone ( BMHMFI ), C₂₄H₁₉N₃O, and (Z)‐2‐{(E)‐[(naphthalen‐1‐yl)methylidene]hydrazinylidene}‐1,2‐diphenylethanone ( BMHFN ) C₂₅H₁₈N₂O. Moreover, the in vitro cytotoxicity of the eight title compounds was evaluated against two tumour cell lines (A549 human lung cancer and 4T₁ mouse breast cancer) and two normal cell lines (MRC‐5 normal lung cells and NIH 3T3 fibroblasts) by MTT assay. The results indicate that four ( BDHMFI , BDHFN , BMHMFI and BMHFN ) are inactive and the other four ( BDHFI , BDHAI , BMHFI and BMHAI ) show severe toxicities against human A549 and mouse 4T₁ cells, similar to the standard cisplatin. All the compounds exhibited weaker cytotoxicity against normal cells than cancer cells. The Swiss Target Prediction web server was applied for the prediction of protein targets. After analyzing the differences in frequency hits between these active and inactive Schiff bases, 18 probable targets were selected for reverse docking with the Surflex‐dock function in SYBYL‐X 2.0 software. Three target proteins, i.e. human ether‐á‐go‐go‐related (hERG) potassium channel, the inhibitor of apoptosis protein 3 and serine/threonine‐protein kinase PIM1, were chosen as the targets. Finally, the ligand‐based structure–activity relationships were analyzed based on the putative protein target (hERG) docking results, which will be used to design and synthesize novel hERG ion channel inhibitors.     

Development of an online X-ray fluorescence analysis system for heavy metals measurement in cement raw meal

ABSTRACT

Particulate matters, gaseous chemicals, and heavy metals emitted from industrial processes into the environment could be directly transmitted to humans through air inhalation. In order to accurately estimate health risk and control the source of pollution caused by cement raw meal, an online X-ray fluorescence analyzer system, consisting of an X-ray fluorescence analyzer with data acquisition software and a laser rangefinder, was developed to carry out the measurement of heavy metals in cement raw meal. The X-ray fluorescence analyzer was mounted on a sled, which can effectively smooth the surface of cement raw meal and reduce the impact of surface roughness during online measurement. The laser rangefinder was mounted over the sled for measuring the distance between cement raw meal sample and the analyzer. Several heavy metals and other elements in cement raw meal were online measured by the X-ray fluorescence analyzer directly above a conveyor belt. The limits of detection for Pb, Cr, Fe, Ti, Ca, and S by the analyzer were 47 ± 1, 33 ± 1, 37 ± 1, 44 ± 1, 246 ± 4, and 118 ± 1 mg kg^?1, respectively. The relative standard deviation (RSD) for the elements mentioned was less than 10.7%. By comparison with the results by inductively coupled plasma mass spectrometry (ICP-MS) and CHNS/O elemental analyzer, relative deviation (D) of the online X-ray fluorescence analyzer was less than 7.4% for Fe, Ti, Ca, and S, between 1.71% and 12.10% for Pb and Cr.     

Stabilizer‐Free Poly(lactide‐co‐glycolide) Nanoparticles Conjugated with Quantum Dots as a Potential Carrier Applied in Human Mesenchymal Stem Cells

We report that human mesenchymal stem cells (hMSCs) were successfully labeled with poly(lactide‐co‐glycolide) nanoparticles (PLGA NPs) surface‐conjugated quantum dots (QDs) (PLGA‐QD NPs) via endocytosis pathway. These NPs were not toxicity even treated with PLGA‐QD NPs at high concentrations for at least four weeks. Besides, PLGA‐QD NPs‐labeled hMSCs did not change their proliferation and differentiation capability toward the cell fates of adipocytes, osteocytes, and chrondrocytes. It's known that PLGA has been widely employed to act as delivery carrier which encapsulates drugs and releases them under a controlled way. Currently, we have also demonstrated that FITC‐loaded PLGA‐QD NPs degraded in hMSCs to achieve intracellular release of FITC. The aim of this research is to investigate viability, proliferation and differentiation capability and the potential for gene delivery of MSCs labeled with PLGA‐QD NPs. In addition to PLGA‐QD NPs, QDs alone were used to serve as a control set for comparison.