非平衡等离子体水处理器的优化设计及性能评价

在正交实验和单因素实验的基础上,对非平衡等离子体水处理反应器的整体结构进行了优化设计,并对优化后反应器的性能进行了定性评价。正交实验结果表明,影响降解效率的因素为气高、液高和气体流量。针高度为4mm、电极间距为17mm、气体流量为96L·h^-1时甲基橙的降解效果最佳。用40目不锈钢网作地电极,采用正脉冲放电能提高降解效率,预处理溶液中放置不锈钢阻挡网有助于提高臭氧的利用率。降解效率和COD去除率随溶液初始浓度的增加而降低,但相同时间内有机污染物的绝对去除量增加,重复实验表明实验误差小于3.5%。     

Influence of wire mesh electrodes on the volume and surface characteristics of dielectric barrier discharge of atmospheric pressure helium

The dielectric barrier discharge of helium in a 6 mm gap at atmospheric pressure was studied. In this paper, the influence of electric field distribution on the uniformity of DBD is analyzed theoretically and verified by experiments. The experimental results show that the mesh electrode produces a local enhancement effect by affecting the electric field and then produces corona discharge, which provides seed electrons for the subsequent discharge process. The effects of mesh diameter and size on discharge uniformity and stability are analyzed, the electrode structure parameters are optimized, the method of a segmented electrode is proposed, and the discharge process and charge distribution are studied. The electrical diagnosis results of plasma technology show that the segmented mesh electrode reduces the breakdown voltage of DBD and increases the charge deposition.     

Numerical study of light-emitting diode with injected current modulated by designed electrode

Numerical model and procedure are developed to study the output optical performance of light-emitting diode (LED) in which injected current is spatially modulated by mesh-like top metal electrode. The mesh strips have rectangular crossection as in realistic LEDs. The finite element method is applied to obtain three-dimensional distributions of electric potential which are incorporated in the equations for total output power. The numerical procedure is applied to evaluate LED’s total output optical power at different geometric parameters of the electrode: the mesh pitch, the width, and the height of the top mesh-like electrodes. Modeling results demonstrate the effect of mesh pitch variation on the output optical power. In particular, at a certain value of the mesh pitch maximum total output optical power is revealed. The presented approach can be used in the optimization of the LEDs with designed metal electrodes.     

Dynamics of ablation plasma induced by a femtosecond laser pulse in electric fields

Direct observations of ablation plasma dynamics in electric field is presented. A time-resolved spatial profile of the ablation plasma induced by femtosecond laser ablation (fsLA) with high fluence is visualized using a planar-laser-induced fluorescence (P-LIF) method. The external electric field is produced by installing a mesh electrode at 6 mm from a Samarium solid target. The Sm ion plasma created by the fsLA showed collective motion regardless of the external electric field, until they reached close to the electrode. When the accelerating and decelerating field was applied, the ions almost disappeared behind the electrode from the field of view. The observations are understood utilizing a SIMION simulation with a conceivable potential gradient caused by Debye shield effect, which is that the ablation plasma keeps the same potential as the target voltage and follows electric potential gradient near the mesh electrode. It is also revealed that this effect degrades time-of-flight resolution at high fluence irradiation. This work gives a new direction for further developments of a fsLA time-of-flight spectrometer.     

铑电极在紫外区的表面增强拉曼散射机理

采用波长为 32 5nm的He Cd激光为激发光源 ,首次在粗糙铑电极上获得了高质量的表面增强拉曼信号。基于在紫外区获得SERS信号这一进展 ,以电磁场理论为基础 ,分别从定性和定量的角度对此新的实验结果做了理论分析。分析表明 ,在紫外区获得的铑的SERS信号主要源自于有着特定形貌的铑纳米粒子所引起的避雷针效应及微弱的表面等离子体共振效应的共同作用。对铑纳米粒子的表面平均SERS增强因子的计算结果与实验值较为一致 ,约为两个数量级。我们同时比较分析了在可见光及近红外区有着极佳SERS增强效应的银基底在采用 32 5nm激发光时却得不到任何SERS信号这一实验结果 ,这是因为银在此紫外区间已完全不能满足表面等离子激元共振的条件所致     

金纳米粒子对黑色素瘤细胞的重离子辐射增敏效应研究

采用配体交换法合成了粒径15 nm左右的11-巯基十一烷酸包被的金纳米粒子（mAuNPs）,使用透射电镜和纳米粒度电位仪对合成后的金纳米粒子进行了表征,然后用MTT法检测了mAuNPs对体外培养小鼠黑色素瘤B16-F10细胞的毒性。在传能线密度（LET）为50 keV/μm的碳离子束照射下,利用香豆素-3-羧酸（3CCA）作为荧光探针检测mAuNPs对水溶液中羟自由基的增强效应、二氯荧光素双醋酸盐（DCFHDA）检测mAuNPs对细胞内活性氧（ROS）的增强效应、克隆形成法检测mAuNPs对B16-F10细胞的辐射增敏效应。实验结果表明:mAuNPs对小鼠黑色素瘤B16-F10细胞基本无毒;mAuNPs对水溶液中的羟自由基产额增强为1.08~2.95倍;在共培养浓度为5 μg/mL情况下mAuNPs增加了胞内活性氧水平,mAuNPs在10%细胞存活水平下的辐射增敏比（SER）为1.15。因此,mAuNPs在黑色素瘤细胞中展现出对重离子的辐射增敏效应。     

In vitro studies of Photofrin® mediated photodynamic therapy on human rhabdomyosarcoma cell line (RD)

In the current study, the cytotoxic effects induced by the given photosensitizer (PS) on human rhybdomyosarcoma cancer cells (RD) as an experimental model were investigated. The experimental results like cytotoxic effects induced by the given PS on RD cells were dose dependent and the optimum concentration of Photofrin® (100 μg/ml) along with 120 J/cm² generates the maximum loss in cell viability which is almost 82%. The significant loss in cell viability is the result of interaction of suitable dose of laser light (630 nm of wavelength) with Photofrin®, after excitation of PS, production of reactive oxygen species (ROS), which leads to mitochondria damage and resulting of cell death (cell necrosis/cell apoptosis). Viability of controlled and treated RD cells with optimum dose of light (630 nm) has been assessed by neutral red assay (NRA) and cell damaging effect were verified by staining of mitochondria using Mitotracker® red as an efficient dye as well as reactive oxygen species (ROS) accumulation detection.     

碱性介质中正丁醇在铂电极上吸附和氧化的电化学原位FTIR反射光谱和EQCM研究

运用电化学循环伏安(CV)、原位FTIR反射光谱和电化学石英晶体微天平(EQCM)等方法研究了碱性介质中正丁醇在Pt电极表面吸附和氧化行为。结果表明：正丁醇电氧化过程与溶液酸碱性有着密切的关系。酸性介质中正丁醇在Pt电极上的CV曲线有2个正向氧化峰,而碱性介质中只有1个正向氧化峰, 第2个氧化峰的消失可能是由于碱性介质中Pt电极表面钝化引起的。原位FTIR反射光谱检测到,在实验条件下,碱性介质中正丁醇电氧化过程的最终产物只有丁酸根。EQCM研究还从电极表面质量定量变化的角度提供了正丁醇反应机理的新数据。     

Detection and comparison of reactive oxygen species (ROS) generated by chlorophyllin metal (Fe, Mg and Cu) complexes under ultrasonic and visible-light irradiation

In this paper, in order to examine the mechanisms of sonodynamic and photodynamic reactions, the chlorophyllin metal (Chl-M (M=Fe, Mg and Cu)) complexes were irradiated by ultrasound (US) and visible-light (VL), respectively, and the generation of reactive oxygen species (ROS) were detected by the method of Oxidation-Extraction Spectrometry (OES). That is, the 1,5-diphenyl carbazide (DPCI) is oxidized by the generated ROS into 1,5-diphenyl carbazone (DPCO), which can display a various visible absorption around 563 nm wavelength. Besides, some influence parameters on the generation of ROS were also reviewed. The results demonstrated an apparent synergistic effect of Chl-M and ultrasonic or visible-light irradiation for the generation of ROS. Moreover, the quantities of generated ROS increase with the increase of (ultrasonic or visible-light) irradiation time and Chl-M (M=Fe, Mg and Cu) concentration. Finally, several quenchers were used to determine the kind of the generated ROS. It is wished that this paper might offer some valuable references for the study on the sonodynamic therapy (SDT) and photodynamic therapy (PDT) mechanisms and the application of Chl-M in tumor treatment.     

X射线诱导的HeLa细胞旁效应中ROS和NO关系研究

活性氧(ROS)和一氧化氮（NO)是辐射诱导的旁效应信号通路中的两个重要信号分子。 实验研究了这两种信号分子在HeLa细胞旁效应信号通路中的关系。 通过微核实验, 发现X射线辐照过的HeLa细胞及其旁观者细胞微核形成明显增加, 而二甲亚砜（DMSO）预处理显著抑制了微核形成。 另外还发现, 接受条件培养基的旁观者细胞的增殖速率增加, 而DMSO预处理产生条件培养基的受辐照细胞则使旁观者细胞的增殖速率降低。 以上的结果从不同角度证实了HeLa细胞存在X射线诱导的旁效应, 且其可以被DMSO预处理所抑制。Western blotting和DAF FM DA荧光探针检测分别显示出辐照后细胞的诱导型一氧化氮合酶（iNOS）和NO水平均升高, 而DMSO预处理则降低其水平。 因此, 可以推测X射线诱导的HeLa旁效应当中ROS是NO的上游信号。 Accumulating evidence indicates that irradiated cells can release signals which induce a series of biological responses in non exposed cells. This is known as irradiation induced bystander effects. Both reactive oxygen species(ROS) and nitric oxide(NO) play important roles in bystander effects. In this study, we determined the relationship of ROS and NO in the signaling pathway of bystander effects. HeLa cells were treated with or without dimethye sulfoxide(DMSO) before X ray irradiation, and micronuclei formation as well as cell proliferation rate was detected in both irradiated and bystander cells. In addition, we also detected inducible nitric oxide synthase(iNOS) expression and NO level in irradiated cells using Western blotting and DAF FM DA fluorescent probe, respectively. Our results showed that micronuclei were induced in irradiated and bystander cells while DMSO treatment significantly suppressed the formation of micronuclei in both of them. We also found that when cells were irradiated their proliferation rate was suppressed while DMSO treatment eliminated this inhibition effect. In contrast, the cells received conditioned medium from irradiated cells proliferated more quickly than the cells received medium from non irradiated cells while DMSO treatment reduced the difference. Finally, we found that irradiated cells had higher level of iNOS and NO compared to non irradiated controls, whereas DMSO treatment decreased their levels. These results suggest that ROS is the upstream signal of NO in X ray induced bystander effects in HeLa cells.     

Protoporphyrin IX-mediated sonodynamic action induces apoptosis of K562 cells

Objectives

The present study aims to investigate apoptosis of human leukemia K562 cells induced by protoporphyrin IX (PpIX)-mediated sonodynamic therapy (PpIX-SDT).

Methods

The uptakes of intracellular PpIX in K562 cells were detected by flow cytometry. The sub-cellular localization of PpIX was imaged by confocal microscope. The cytotoxic effect of PpIX-SDT was assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenylter-trazolium bromide tetrazolium) assay. Apoptosis was evaluated by chromatin condensation with DAPI (4′-6-diamidino-2-phenylindole) staining, decrease of mitochondria membrane potential (MMP), re-distribution of Bax, and the expression changes of the key apoptosis-associated protein (Caspase-3 and polypeptide poly (ADP-robose) polymerase). The possible mechanism of SDT-induced apoptosis was investigated by detecting by intracellular ROS (reactive oxygen species) generation and effect of ROS scavenger-NAC (N-acetylcysteine) on SDT induced apoptosis.

Results

The intracellular PpIX increased quickly within 2 h after PpIX administration and PpIX mainly localized in the mitochondria. Compared with PpIX alone and ultrasound alone groups, the synergistic cytotoxicity of PpIX plus ultrasound was significantly boosted. In addition, the ultrasound induced some extent of chromatin condensation and MMP loss was greatly enhanced by the presence of 2 μg/ml PpIX, where PpIX alone treatment showed no or only slight effect. Time-dependent Bax translocation, caspase-3 activation and PARP cleavage were detected in SDT treatment groups. Besides, intracellular ROS production was significantly enhanced after SDT, and the general ROS scavenger NAC could obviously alleviate the SDT-caused cell viability loss, MMP loss, Bax redistribution and nuclear changes.

Conclusions

These results indicated that PpIX-mediated sonodynamic action could induce apoptosis on K562 cells, and the intracellular ROS was involved in the PpIX-SDT induced apoptosis.     

Spectroscopic investigation on the sonodynamic activity of Safranine T to bovine serum albumin damage

In this paper, the Safranine T (ST) was used as sonosensitive compound to study the sonodynamic damage to bovine serum albumin (BSA) under ultrasonic irradiation using fluorescence and UV–vis spectroscopy. The experimental results revealed the obvious synergetic effect of Safranine T (ST) and ultrasonic irradiation during the damage of BSA molecules. In addition, some influencing factors such as ultrasonic irradiation time, Safranine T (ST) concentration, pH value and ionic strength on the sonodynamic damage of BSA molecules were also considered. Finally, the generation of reactive oxygen species (ROS) in sonodynamic process was estimated by the method of Oxidation-Extraction Photometry (OEP). Meanwhile, several radical scavengers were used to determine the kind of generated ROS. Experiments showed that under ultrasonic irradiation the Safranine T (ST) can generate several kinds of ROS at the same time, at least including singlet oxygen (¹O₂) and hydroxyl radicals (OH).     

筛网盘对聚α-甲基苯乙烯微球弹跳性能的影响

 介绍了利用筛网设计制作出的一种新型的反弹盘,并用于聚α-甲基苯乙烯（PAMS）微球的弹跳实验。分析了筛网盘与玻璃盘之间的差别和由此带来的对PAMS微球弹跳性能影响。通过实验分别研究了筛网盘相关的参数对微球表面粗糙度的影响。结果表明：采用筛网盘与玻璃盘相比,PAMS微球的弹跳性能的改善非常明显;筛网盘的使用较好地解决了在无等离子体的镀膜环境下（如热蒸发的方法制备PAMS微球表面聚酰亚胺涂层）PAMS微球的弹跳问题;为降低微球表面粗糙度,反弹盘应采用间歇振动的模式。     

Modeling Fraunhofer diffractive characteristics for modulation transfer function analysis of tilted ring metallic mesh

In order to analyze the Fraunhofer diffractive characteristics and modulation transfer function (MTF) of a tilted ring metallic mesh, an optical intensity distribution model of Fraunhofer diffraction is built using Huygens–Fresnel diffraction theory and the diffraction integral is carried out directly in the tilted mesh plane. The diffraction characteristics of the tilted ring metallic mesh are in good agreement with experimental results, which proves the correctness of the model established. MTF of an optical system with metallic mesh is calculated based on the model established and Fourier transform. Analysis shows that the degradation of MTF caused by diffraction of a ring mesh is much less than that of a square mesh whether they are vertical or tilted to the optical axis. Therefore, ring mesh can provide higher imaging quality than square mesh when they are used as high-pass filters in optical windows. A tilted array diffraction modulating factor is abstracted and believed useful in the analysis of diffractive characteristics of tilted square mesh and ring mesh, and it can be extended to Fraunhofer diffractive characteristics analysis of other tilted diffraction arrays.     

Apoptosis induced by sonodynamic treatment by protoporphyrin IX on MDA-MB-231 cells

Sonodynamic therapy (SDT) is a promising modality for cancer treatment, involving the synergistic interaction of ultrasound and some chemical compounds termed as sono-sensitizers. It has been found that SDT can lead to apoptotic cell death because of the induction of direct sonochemical and subsequent redox reactions. However, the detailed mechanisms are not clear. This study was to identify the cytotoxic effects of ultrasound-activated protoporphyrin IX (PpIX) on MDA-MB-231 cells. The fluorescence microscope was used to detect the sub-cellular localization of PpIX. Several distinct sonochemical effects were found after SDT treatment, including the decrease of cell viability, generation of intracellular ROS, the loss of mitochondrial membrane potential. The activation of some special apoptosis-associated proteins [Caspase-9, Caspase-3 and polypeptide poly (ADP-robose) polymerase] was evaluated by western blotting. The results show that PpIX mediated SDT (PpIX-SDT) treatment could obviously inhibit the proliferation of MDA-MB-231 cells, and which was significantly reduced by the pan-Caspase inhibitor z-VAD-fmk and the reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC). Further, SDT induced a conspicuous loss of mitochondrial membrane potential (MMP) and a mass of ROS accumulation in MDA-MB-231 cells at 1 h post-treatment and the SDT-treated cells showed obvious Caspase-3 and Caspase-9 activation, and PARP cleavage at 6 h after treatment. And, the general apoptosis marker-Caspase-3 activation-was also greatly relieved by NAC. These findings primarily indicate a Caspase-depended apoptosis could be induced by PpIX-SDT in MDA-MB-231 cells, and the intracellular ROS was involved during the apoptotic process.     

Ultrasound-assisted blue light killing Vibrio parahaemolyticus to improve salmon preservation

Vibrio parahaemolyticus is a typical marine bacterium, which often contaminates seafood and poses a health risk to consumers. Some non-thermal sterilization technologies, such as ultrasonic field (UF) and blue light (BL) irradiation, have been widely used in clinical practice due to their efficiency, safety, and avoidance of drug resistance, but their application in food preservation has not been extensively studied. This study aims to investigate the effect of BL on V. parahaemolyticus in culture media and in ready-to-eat fresh salmon, and to evaluate the killing effectiveness of the UF combined with BL treatment on V. parahaemolyticus. The results showed that BL irradiation at 216 J/cm² was effective in causing cell death (close to 100%), cell shrinkage and reactive oxygen species (ROS) burst in V. parahaemolyticus. Application of imidazole (IMZ), an inhibitor of ROS generation, attenuated the cell death induced by BL, indicating that ROS were involved in the bactericidal effects of BL on V. parahaemolyticus. Furthermore, UF for 15 min enhanced the bactericidal effect of BL at 216 J/cm² on V. parahaemolyticus, with the bactericidal rate of 98.81%. In addition, BL sterilization did not affect the color and quality of salmon, and the additive UF treatment for 15 min did not significant impact on the color of salmon. These results suggest that BL or UF combined with BL treatment has potential for salmon preservation, however, it is crucial to strictly control the intensity of BL and the duration of UF treatment to prevent reducing the freshness and brightness of salmon.     

丝网印刷制备染料敏化太阳能电池

染料敏化太阳能电池（DSSC）是太阳能电池研究的热点领域之一,使用丝网印刷技术制备以纳米晶多孔TiO₂薄膜为光阳极的DSSC具有低成本、简单的制备工艺和高的光电转换效率（PCE）的特点,这类太阳能电池受到人们广泛关注。为了提高这类太阳能电池的光电转换效率,通过采用不同网目相同印刷胶体制备了太阳能电池的光阳极优化印刷工艺十分重要,采用不同网目的方法研究印刷工艺对太阳能电池光伏性能的影响是十分有效的。用溶胶-凝胶法制备了TiO₂胶体,通过扫描电镜看出TiO₂薄膜具有多孔结构,其高比表面积有利于薄膜对染料分子的吸附,也有利于提高电池对太阳光的吸收率。经过高温烧结后丝网印刷的TiO₂薄膜展现了明显的锐钛矿结构较窄衍射峰,意味着TiO₂颗粒已经完全晶化且粒径增加。制备目数从100增到300导致网孔直径减少而薄膜变得更加致密,使得TiO₂薄膜的XRD衍射峰逐渐增强,而从300目增到400目时由于网孔过小导致TiO₂胶体通过网孔数量变小使得衍射峰强度下降。用不同网目印刷了单层TiO₂光阳极研究DSSCs光伏性能的变化情况,发现制备目数是200目和300目印刷太阳能电池的性能较好,而400网目印刷太阳能电池的性能最差,这与XRD观察的结果一致。再分别采用网目为100目、200目、300目和400目的印网将胶体印刷成了多层TiO₂薄膜,以此为基础组装DSSC。实验结果表明：通过不同组合网目的丝网印刷制备TiO₂薄膜,组装后的染料敏化太阳能电池的光电转换效率得到了显著提升,其中以300目+200目+100目三层叠印时得到的优化光阳极的最高电池效率达到6.9%。以丝网印刷的方法制备电极不需要进行任何化学处理,在较高网目制备底层的情况下印刷的薄膜均匀牢固,且电池制备的步骤简单、重复性好,能量转换效率较高。     

ESR Study in Reactive Oxygen Species Free Radical Production of Pinus kesiya var. langbianensis Heartwood Treated with Laccase

Enzymatic oxidation of lignin phenolic hydroxyl groups can enhance the level of autoadhesion between wood fibers or particles depending upon the bonding mechanism of wood-based materials without synthetic adhesives such as urea and phenol formaldehyde. The adhesive effect is caused by an increased number of reactive oxygen groups at the fiber surface. The parameters of laccase-treated wood fibers play vital roles in generating reactive oxygen species (ROS) free radicals. Laccase I (white-rot fungi) and laccase II (Aspergillus sp.) are used to catalyze the oxidation of heartwood powder of Pinus kesiya var. langbianensis in suspension under different pH values, temperatures, treatment times and different laccase concentrations. Electron spin resonance spectroscopy and spin trapping technique were used to detect the ROS free radicals generated in the laccase-treated heartwood powder and it was found that in it the concentration of ROS free radicals was higher than that in the control. Analysis of variance indicates that there was a significant difference between the ROS concentration values of laccase-treated heartwood powder under different pH values, treatment temperatures and times, and laccase dosages for both laccase I and II. Furthermore, the concentration of ROS free radicals generated by laccase I is higher than that generated by laccase II. It was found that the optimum conditions for generation of ROS in laccase-treated heartwood powder by the two kinds of laccase are pH 3.0; treatment temperature, 50 °C; treatment time, 2 h; enzyme concentration, 20 units/g of wood powder. Authors' address: Xinfang Duan, Research Institute of Wood Industry, Chinese Academy of Forestry, Wan Shou Shan, Beijing 100091, People's Republic of China     

不同电极结构下介质阻挡放电电离特征的试验研究

由于具有工作气压高、放电均匀等特点,大气压介质阻挡放电成为近年来非平衡等离子体领域研究的主要技术。电极结构是电离特性的主要影响因素之一,因此,通过电极结构优化来改善电离特性,对等离子体放电设备的应用领域拓展及性能优化至关重要。为改善大气压介质阻挡放电的电离特性,产生高活性、高均匀性的低温等离子体,基于自主设计的同轴介质阻挡放电装置进行了不同电极结构的电离试验及参数诊断;在一个标准大气压、放电频率11.4 kHz、放电峰值电压5.4～13.4 kV条件下进行了氩气电离试验;采用原子发射光谱法（AES）对氩等离子体谱线的激发、分光进行了检测分析;研究了螺纹电极、齿状电极、圆柱电极放电的特征光谱参数及外施电压对介质阻挡放电特征参数的影响。结果表明,齿状电极放电所形成等离子体的放电强度更大且放电效果显著,电子平均能量利用率低,电子激励温度弱于圆柱电极;圆柱电极放电强度较弱,但易形成大面积均匀性等离子体;大气压环境下电子激励温度不因外源电压的升高而单调递加,这表明通道内微放电的主要特征并不依赖于外施电压的供给,而是取决于电极结构、气体组份、气体压强;增大外施电压仅能增加单位时间内微放电的数量,经整合电子激励温度可达3 500 K,符合典型的低温等离子体特征。     

同轴虚阴极微波输出模式分析

 对不同透过率的阳极网进行实验研究，得到了主频为3.4 GHz和3.7 GHz的辐射微波，对同轴虚阴极内的电子束分布进行了分析。对同轴虚阴极内的本征模式进行了计算，并与实验结果进行比较。实验结果表明：网内电子束的分布对微波输出模式有重要影响；同轴虚阴极微波频率是阴阳极间距及谐振腔共同作用的结果；阳极网透过率对频率有显著影响，透过率越高，则微波频率相应提高。