树叶为模板网状TiO2的制备及其光催化性能

采用模板法与溶胶-凝胶法相结合的方法, 以羽状网脉的洋槐树叶为模板制备出网状的二氧化钛光催化材料. 利用红外光谱仪(FT-IR)、扫描电子显微镜(SEM)、能量色散型X射线光谱仪(EDX)、X射线衍射仪(XRD)对样品的表面形貌、成分和晶型进行表征, 以甲基橙的脱色降解为模式反应, 考察了宏观形貌对TiO₂光催化性能的影响. 结果表明: 以树叶为模板制得的TiO₂, 呈网状结构, 网孔直径约为5～10 μm, 且有少量直径约为2～3 μm规则球形和直径约5 μm管状的TiO₂; 当pH＝3时, 网状TiO₂在3 h内对甲基橙的降解率分别比粉末TiO₂高37.2%, 比商品粉末TiO₂高44.6%, 且重复使用4次后, 降解率仍能保持在90%以上, 明显优于粉末TiO₂, 同时为制备其它形貌的TiO₂提供一种新思路.     

基于微流体脉冲驱动控制技术的电化学微流控芯片制备方法

基于微流体脉冲驱动控制技术搭建了电化学微流控芯片的制备系统.首先将纳米银墨水和甘油溶液分别微喷射到玻璃基底表面形成微电极图形和微流道液体阳模图形;然后分别进行烧结和聚二甲基硅氧烷(PDMS)模塑工艺制得微电极和微流道;最后将微电极和微流道键合形成电化学微流控芯片.研究了系统参量对液滴产生的影响以及液滴直径和重叠率对液滴成线的影响,制得的微电极最小线宽为45 μm、厚度为2.2 μm、电阻率为5.2 μΩ·cm,制得的微流道最小线宽为35 μm,流道表面光滑.采用制得的电化学微流控芯片进行了葡萄糖浓度的电化学流动检测.结果表明,葡萄糖溶液的浓度与响应电流具有较高的线性关系,可对一定浓度范围内的葡萄糖溶液进行定量检测.基于微流体脉冲驱动控制技术的电化学微流控芯片制备方法具有微喷射精度高、重复性好,制备系统结构简单、成本低廉等优点,可用于生化分析、生物传感器等领域的芯片制备.     

HAP自组装球的简易合成及其光催化增效作用

选择生物协同模板,通过简单的控制组装工艺,制备出结构均一有序的羟基磷灰石(HAP)纳米组装球.该纳米组装球整体尺寸约5-6 μm,球体中心部分尺寸约为2.5-3 μm.通过X射线粉末衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、傅里叶变换红外(FT-IR)光谱、比表面积(BET)测试等手段对产物形貌、结构和比表面积进行了表征.产物作为催化剂载体,对氧化锌催化降解罗丹明B (RhB)的催化效率提高了125%,催化剂回收率提高了23.1%,有效降低了催化剂的用量,在有机物降解领域具有潜在的应用价值.同时还对产物的控制生成过程和催化增效机理做了初步探讨.     

多层纸芯片乳腺癌组织微阵列用于抗肿瘤药物测试

开发了一种多层纸芯片细胞培养平台,将乳腺癌细胞分别接种于多层的图形化纸芯片的亲水区,折叠后构建了仿真实体肿瘤.多层纸芯片覆以微孔薄膜,用以仿真血管内皮层.培养不同时间后,拆解多层纸芯片检测乳腺癌组织内各层面的细胞形态、存活率、细胞周期分布以及细胞内乳酸含量.实验结果显示,各层纸芯片培养的乳腺癌细胞存活率均高于80％,并形成了类组织结构.芯片乳腺癌组织内部呈酸化倾向,且酸化程度随着培养时间的延长而升高.与二维(2D)培养细胞相比较,纸芯片乳腺癌组织内细胞增殖比例显著降低(15％ vs 60％).多层纸芯片乳腺癌组织显示了更接近体内情况的药物反应机制,细胞存活率随阿霉素浓度升高呈现缓慢下降趋势,IC50值显著高于2D培养细胞组(5.0 μmol/L vsl.144 μmol/L).这种多层纸芯片乳腺癌组织微阵列构建简便、仿真度高,有望成为抗肿瘤药物反应测试的有力工具.     

富钾正长岩水热分解生成沸石反应热力学

以安徽某地富钾正长岩粉体为原料,研究其水热碱法分解生成沸石化合物的反应热力学。采用“聚合多面体模型”计算了几种沸石的热力学参数,结合矿物端员组分热力学数据及“混合电解质模型”,构建了富钾正长岩-NaOH-H₂O水热体系平衡热力学模型。反应Gibbs自由能计算结果表明,在160-300 ℃范围内,由富钾正长岩水热分解生成羟钙霞石、方沸石、P型、A型等沸石的反应可自发进行;通过OLI Analyzer 9.3软件对该体系不同条件下的相平衡进行模拟,预测了富钾正长岩水热碱法分解生成羟钙霞石、方沸石的反应条件。通过实验验证,生成的方沸石呈规则的四角三八面体晶型,粒径约50 μm;羟钙霞石呈柱状,长约20 μm,截面尺寸约500 nm-1 μm,K₂O溶出率97%以上。     

框架核酸辅助的仿生膜构建

仿生膜的构建有利于了解并掌握生物膜的功能及其机理, 同时对其在生命医学及疾病诊断等相关领域的应用具有重要意义. 以框架核酸为组装单元, 构建新型仿生膜材料是一种有效且具有发展前景的方法和研究方向. 本文综述了框架核酸的设计、 制备与表征, 总结了框架核酸修饰到脂质膜上的方式. 同时, 对框架核酸辅助的仿生膜的应用情况进行了阐述, 并探讨了框架核酸在仿生膜研究领域所面临的机遇与挑战.     

小型微流控芯片流式细胞仪的研制

基于芯片正交光路检测模式,搭建了一套小型的微流控芯片流式细胞仪.以532 nm小型半导体激光器作为激发光源,激光束被透镜聚焦于芯片通道中央.采用光电二极管检测芯片通道内流动细胞的前向散射光信号,采用小型光电倍增管检测荧光信号,整套仪器体积为19 cm×15 cm×25 cm(长×宽×高),具有结构简单、体积小、价格低廉等特点.荧光检测系统对四甲基罗丹明异硫氰酸的检出限为4.4×10-8 mol/L,采用6 μm荧光微球作为模型样品考察了仪器的分析性能,同时初步实现了细胞样品的分析.     

邻苯二酚做螯合剂合成不同粒度、形貌的全硅方钠石分子筛大单晶

将邻苯二酚作为螯合剂加入到合成全硅方钠石分子筛的体系 (SiO2-NaOH -EG -R(R :邻苯二酚 ) )中 ,合成了 15 μm× 15 μm× 15 μm～ 6 0 μm×6 0 μm× 6 0 μm粒度不等的高质量的Si-SOD分子筛单晶 .实验结果表明 :当体系中有邻苯二酚存在时得到的产物具有较大尺寸和完美形貌的单晶 ,而不加邻苯二酚时却得到尺寸很小的孪晶 ;同时 ,体系中邻苯二酚的含量对晶体的粒度也有很大影响 .晶化动力学表明 ,邻苯二酚的加入极大地降低了晶化速度 ,这可能与体系中形成了硅 -邻苯二酚螯合物有关     

方波射频电压幅值对微型高场非对称波形离子迁移谱传感器芯片性能的影响

基于微机电系统技术(Micro electro mechanical system,MEMS),研制了微型高场非对称波形离子迁移谱(High-field asymmetric waveform ion mobility spectrometry,FAIMS)传感器芯片。芯片采用感应耦合等离子体(ICP)刻蚀和两次硅-玻璃键合工艺加工,尺寸为18.8mm×12.4mm×1.2mm,其中迁移区尺寸为10mm×5mm×0.2mm。设计了高场非对称方波电源,可输出最大频率2MHz,电压峰-峰值1000V,占空比20%～50%连续可调的方波射频电压。以乙醇为实验样品,分析了方波射频电压幅值对FAIMS传感器芯片性能的影响。实验表明,随着电压幅值的增加,FAIMS分辨率提高,灵敏度下降,补偿电压绝对值增大,且芯片对乙醇的检出限可达8.9mg/m3。     

静电层层自组装制备聚苯乙烯微球(核)/MCM-41纳米粒子(壳)阶层结构复合微粒

采用聚苯乙烯磺酸钠(PSS)和聚二烯丙基二甲基氯化铵(PDDA)两种聚电解质, 通过静电层层自组装成功地将MCM-41介孔二氧化硅纳米粒子包覆到聚苯乙烯(PS)微球表面. 实验结果表明, 当以尺寸为1.4 μm的PS微球为核时, 包覆了两个聚电解质双层(PDDA/PSS)2的PS(PDDA/PSS)2(PDDA/MCM-41)复合结构微粒与包覆了一个聚电解质双层(PDDA/PSS)的PS(PDDA/PSS)(PDDA/MCM-41)复合结构微粒相比, 复合结构微粒之间的交联程度降低, 但是MCM-41纳米粒子在聚苯乙烯微球表面的包覆都比较松散, 且产物中存在大量杂质. 而当以尺寸为5 μm的聚苯乙烯微球为核时, MCM-41纳米粒子紧密地包覆在聚苯乙烯微球表面, 复合结构微粒之间只有少量桥连物, 且产物中杂质很少.     

流动聚焦型微流控体系中的液滴的图案化排列和转变模式

流体在微流通道中形成剪切流场（低雷诺数）．不同于宏观体系,由于剪切力和表面张力的竞争作用,产生的液滴在微尺度下的微流通道中形成特殊的排列现象---周期性类似“晶格”排列现象．设计了新型流动聚焦型微流控芯片,分析研究在微流体系中液滴周期性图案化排列和转变机理性,液滴排列模式受两方面因素影响：水油两相的流速比值和微通道尺寸．当微通道宽度为250或300 μm时,液滴形成单层分散,双层和单层挤压排列．当微通道宽度为350 μm 时,液滴会形成单层分散到三层排列到双层挤压最后到单层挤压排列．当出口通道宽度增加到400 μm时,甚至出现了液滴四层排列的现象．同时研究了各个液滴排列模式的“转变点”.     

High‐throughput and sensitive particle counting by a novel microfluidic differential resistive pulse sensor with multidetecting channels and a common reference channel

High‐throughput particle counting by a differential resistive pulse sensing method in a microfluidic chip is presented in this paper. A sensitive differential microfluidic sensor with multiple detecting channels and one common reference channel was devised. To test the particle counting performance of this chip, an experimental system which consists of the microfluidic chip, electric resistors, an amplification circuit, a LabView based data acquisition device was developed. The influence of the common reference channel on the S/N of particle detection was investigated. The relationship between the hydraulic pressure drop applied across the detecting channel and the counting throughput was experimentally obtained. The experimental results show that the reference channel designed in this work can improve the S/N by ten times, thus enabling sensitive high‐throughput particle counting. Because of the greatly improved S/N, the sensing gate with a size of 25 × 50 × 10 μm (W × L × H) in our chips can detect and count particles larger than 1.5 μm in diameter. The counting throughput increases with the increase in the flowing velocity of the sample solution. An average throughput of 7140/min under a flow rate of 10 μL/min was achieved. Comparing with other methods, the structure of the chip and particle detecting mechanism reported in this paper is simple and sensitive, and does not have the crosstalking problem. Counting throughput can be adjusted simply by changing the number of the detecting channels.     

Automatic hierarchy classification in venation networks using directional morphological filtering for hierarchical structure traits extraction

The extraction of vein traits from venation networks is of great significance to the development of a variety of research fields, such as evolutionary biology. However, traditional studies normally target to the extraction of reticulate structure traits (ReSTs), which is not sufficient enough to distinguish the difference between vein orders. For hierarchical structure traits (HiSTs), only a few tools have made attempts with human assistance, and obviously are not practical for large-scale traits extraction. Thus, there is a necessity to develop the method of automated vein hierarchy classification, raising a new challenge yet to be addressed. We propose a novel vein hierarchy classification method based on directional morphological filtering to automatically classify vein orders. Different from traditional methods, our method classify vein orders from highly dense venation networks for the extraction of traits with ecological significance. To the best of our knowledge, this is the first attempt to automatically classify vein hierarchy. To evaluate the performance of our method, we prepare a soybean transmission image dataset (STID) composed of 1200 soybean leaf images and the vein orders of these leaves are manually coarsely annotated by experts as ground truth. We apply our method to classify vein orders of each leaf in the dataset. Compared with ground truth, the proposed method achieves great performance, while the average deviation on major vein is less than 5 pixels and the average completeness on second-order veins reaches 54.28%.     

膜吸附反应器（MAR）对饮用水系统中病毒的去除

以尺寸与人体肠道病毒相近的f2噬菌体作为模型病毒,本研究采用膜吸附反应器（Membrane adsorption reactor,MAR）,考察膜分离与纳米TiO2耦合工艺对饮用水中病毒的去除效果．两种不同孔径的PVDF（0．20μm）、PAN（0．05μm）平板膜在自来水体系中对f2噬菌体的截留效果分别为1．88～2．56log和4．78～5．95log,大大超过理论计算值,这与膜具有不规则孔型的重叠筛网状结构直接相关．吸附实验结果表明,纳米TiO2对f2噬菌体的吸附在60min内即可达到吸附平衡,符合Freundlich等温吸附模型qe=27．4·Ce1.24．两组MAR系统对f2噬菌体的总去除率分别高达3．88log与6．40log,这主要是由于纳米TiO2的吸附作用,以及运行中在膜表面形成有效的滤饼层．纳米材料与膜系统的耦合既保持了系统对病毒的高效去除,又实现了纳米颗粒的有效分离回收,操作简单、费用低．     

Multifunctional protein processing chip with integrated digestion, solid-phase extraction, separation and electrospray

We describe a microfluidic device in which integrated tryptic digestion, SPE, CE separation and electrospray ionization for MS are performed. The chip comprised of 10 × 30 μm channels for CE, and two serially connected 150?μm deep, 800?μm wide channels packed with 40 to 60 μm diameter beads, loaded with either immobilized trypsin, reversed-phase packing or both. On-chip digestion of cytochrome c using the trypsin bed showed complete consumption of the protein in 3 min, in contrast to the 2 h required for conventional solution phase tryptic digestion. SPE of 0.25 μg/mL solutions of the peptides leu-enkephalin, angiotensin II and LHRH gave concentration enhancements in the range of 4.4-12, for a ten times nominal volume ratio. A 100 nM cytochrome c sample concentrated 13.3 times on-chip gave a sequence coverage of 85.6%, with recovery values ranging from 41.2 to 106%. The same sample run without SPE showed only five fragment peaks and a sequence coverage of 41.3%. When both on-chip digestion and SPE (13.3 volume ratio concentration enhancement) were performed on 200 nM cytochrome c samples, a sequence coverage of 76.0% and recovery values of 21-105% were observed. Performing on-chip digestion alone on the same sample gave only one significant fragment peak. The above digestion/peptide concentration step was compared to on-chip protein concentration by SPE followed by on-chip digestion with solution phase trypsin. Both procedures gave similar recovery results; however, much larger trypsin autodigestion interference in the latter approach was apparent.     

丙丁梭菌萃取发酵产物的气相色谱分析

建立了3种溶剂中产物丙酮、乙醇、正丁醇的气相色谱分析方法。色谱条件为:DB-624色谱柱(30 m×0.32 mm,1.8μm)及FFAP色谱柱(30 m×0.32 mm,0.25μm),FID检测器,程序升温,氮气为载气。采用内标法定量,内标物为异丁醇,进样体积1μL。丙酮、乙醇、正丁醇的浓度与色谱峰面积线性相关,相关系数为0.997 43~0.999 97,测定结果的相对标准偏差为0.19%~2.01%(n=5),回收率为95.1%~101.2%。     

花生叶表面的高黏附超疏水特性研究及其仿生制备

花生是一种常见的豆科作物.与低黏附超疏水的荷叶不同,花生叶表面同时具有超疏水和高黏附特性.水滴在花生叶表面的接触角为151±2°,显示出超疏水特性.此外,水滴可以牢固地附着在花生叶表面,将花生叶翻转90°甚至180°,水滴均不会从表面滚落,显示了良好的黏附性(黏附力超过80μN).研究发现,花生叶表面呈现微纳米多级结构,丘陵状微米结构表面具有无规则排列的纳米结构.花生叶表面特殊的微纳米多尺度结构是其表面呈现高黏附超疏水特性的关键因素.结合实验数据,对花生叶表面特殊浸润性机理进行了简要阐述.受此启发,利用聚二甲基硅氧烷复形得到了与花生叶表面微结构类似的高黏附疏水表面.本文以期为仿生制备高黏附超疏水表面提供新思路.     

SERS decoding of micro gold shells moving in microfluidic systems

In this study, in situ surface‐enhanced Raman scattering (SERS) decoding was demonstrated in microfluidic chips using novel thin micro gold shells modified with Raman tags. The micro gold shells were fabricated using electroless gold plating on PMMA beads with diameter of 15 μm. These shells were sophisticatedly optimized to produce the maximum SERS intensity, which minimized the exposure time for quick and safe decoding. The shell surfaces produced well‐defined SERS spectra even at an extremely short exposure time, 1 ms, for a single micro gold shell combined with Raman tags such as 2‐naphthalenethiol and benzenethiol. The consecutive SERS spectra from a variety of combinations of Raman tags were successfully acquired from the micro gold shells moving in 25 μm deep and 75 μm wide channels on a glass microfluidic chip. The proposed functionalized micro gold shells exhibited the potential of an on‐chip microfluidic SERS decoding strategy for micro suspension array.     

微流控芯片流动注射气体扩散分离光度测定系统的研究

提出了纳升级进样量的微流控芯片流动注射气体扩散分离光度检测系统. 制作三层结构微流控芯片, 在玻璃片上加工微反应通道, 用聚二甲基硅氧烷[Poly(dimethylsiloxane), PDMS]加工气体渗透膜和具有接收气体微通道的底片, 实现了生成气体的化学反应、气-液分离和检测在同一微芯片上的集成化. 采用缝管阵列纳升流动注射进样系统连续进样, 用吸光度法测定NH+4以验证系统性能. 结果表明， 该系统对NH+4的检出限为140 μmol/L(3σ), 峰高精度为3.7%(n=9). 在进样时间12 s、注入载流48 s和每次进样消耗200 nL试样条件下, 系统分析通量可达60样/h. 若加大样品量到800 nL, 使接收溶液停流1 min, 该系统对NH+4的检出限可达到35 μmol/L(3σ), 但分析通量降低到20样/h.     

高氯酸镱对大鼠背根神经元细胞毒性及膜上钾通道的影响

研究了高氯酸镱(Yb(ClO4)3)诱导大鼠背根神经(DRG)元凋亡、引起胞内钙离子浓度变化以及对膜上钾离子通道的影响.急性分离大鼠DRG细胞,用不同浓度的Yb(ClO4)3处理DRG细胞24和96h,采用流式细胞仪和激光共聚焦法,检测细胞的凋亡和细胞内钙离子荧光强度的变化.利用全细胞膜片钳法,记录Yb(ClO4)3对细胞膜上不同钾通道电流的影响.结果表明,10,100,1000μmol/L Yb(ClO4)3处理DRG神经元24h,细胞基本不表现凋亡;处理96h,细胞出现明显的凋亡(P0.05～0.01),尤其是1000μmol/L Yb(ClO4)3,凋亡率达到了(55.23±3.76)%(P0.01).经Yb(ClO4)3孵育的DRG神经元胞内的Ca2+的荧光强度显著增大;Yb(ClO4)3抑制背根神经节纤维和神经元突起的生长.Yb(ClO4)3抑制DRG神经元膜上的钾电流,胞内和胞外的Yb(ClO4)3作用钾通道的部位不同.细胞外液中的Yb(ClO4)3不同程度地阻断了瞬间外向钾电流IA,对延迟整流钾电流几乎没影响;往电极内液中加入同样浓度的Yb(ClO4)3对IA影响很小,却特异性地阻断了延迟整流钾电流IK.10μmol/L Yb(ClO4)3使IA的激活和失活过程都显著右移,延长了瞬间外向钾电流达到峰值的时间和快速失活时间常数,增加神经元的兴奋性.