Perturbation of a collisional plasma by exterior bodies in a uniform external electric field

The charging of a metal sphere in a weakly ionized collisional plasma in a uniform external electric field is investigated with allowance for the effect of the space charge field and ionization-recombination processes. The sphere charge and the spatial distributions of charged plasma particles are calculated both numerically and analytically (for some particular cases) for the case of a strong external field. It is found that the size of the perturbed plasma region is determined by the external field and the intensity of recombination processes. It is shown that the total electric charge (the sphere charge plus the plasma space charge) is zero in accordance with predictions of the theory of static currents in a conducting medium.     

Interaction between two conducting spheres in weakly ionized collisional plasma

Charging of two conducting spheres in a weakly ionized collisional plasma flow is considered. The spheres are arranged along the flow, and the plasma is assumed to consist of two ion species with the charges equal in magnitude but opposite in sign. The problem is analyzed with allowance for the external electric field, charging of the spheres due to the sedimentation of plasma ions on them, the fields of the sphere charges, the space charge field, and the processes of recombination and molecular diffusion. The interaction between the spheres and plasma is studied by numerically solving a time-dependent problem in a bispherical coordinate system by the finite difference method. The steady-state values of the sphere charges and the distributions of the space charge and ion densities in the ambient plasma are found as functions of the plasma parameters and the distance between the spheres. The electrostatic forces acting on the spheres are determined, and the effects of the external field, the space charge fields, and the fields of the sphere charges are comparatively analyzed. It is shown that, for the considered plasma parameters, the main electrostatic effect in the interaction between two spheres is their mutual approach in the external field due to the difference in their charges (one sphere catches up with the other). Due to the friction force with the neutral gas, this mutual approach is much slower than all other processes in the system. For widely spaced spheres, the results coincide with the solution obtained previously for a solitary sphere.     

Theory of the polarization bremsstrahlung from thermal electrons scattered by the Debye sphere of an ion in a plasma

The polarization bremsstrahlung from thermal electrons scattered by the Debye sphere of an ion in a plasma is studied in the quasiclassical approximation. The model of the local plasma frequency is used to check the validity of the asymptotic expression for the polarizability of the electron cloud of an ion in the high-frequency range. This asymptotic expression is then used to derive a formula for the intensity of the total effective polarization bremsstrahlung. The R factor (the ratio of the contribution from the polarization bremsstrahlung to the contribution from conventional static bremsstrahlung) is obtained as a function of the plasma coupling parameter and electron density in order to analyze the role of the polarization bremsstrahlung in the total bremsstrahlung of the thermal plasma electrons. The spectral intensity of the effective polarization bremsstrahlung is calculated in the rotational approximation, which was previously employed in the theory of conventional static bremsstrahlung. It is shown that the spectral intensity of the polarization bremsstrahlung from thermal electrons scattered by the Debye sphere around an ion, as compared with the polarization bremsstrahlung by fast superthermal electrons, decreases more gradually with increasing frequency.     

Influence of the electron density on the characteristics of terahertz waves generated under laser–cluster interaction

A theory of generation of terahertz radiation under laser–cluster interaction, developed earlier for an overdense cluster plasma [A. A. Frolov, Plasma Phys. Rep. 42. 637 (2016)], is generalized for the case of arbitrary electron density. The spectral composition of radiation is shown to substantially depend on the density of free electrons in the cluster. For an underdense cluster plasma, there is a sharp peak in the terahertz spectrum at the frequency of the quadrupole mode of a plasma sphere. As the electron density increases to supercritical values, this spectral line vanishes and a broad maximum at the frequency comparable with the reciprocal of the laser pulse duration appears in the spectrum. The dependence of the total energy of terahertz radiation on the density of free electrons is analyzed. The radiation yield is shown to increase significantly under resonance conditions, when the laser frequency is close to the eigenfrequency of the dipole or quadrupole mode of a plasma sphere.     

Analysis of low molecular weight plasma proteins using ultrafiltration and large gel two‐dimensional electrophoresis

In this study, various solvent systems were applied to obtain a high and consistent recovery rate of low molecular weight plasma proteins (LMPP) from human plasma. A buffer system containing 7 M urea, 2 M thiourea, 25 mM NH₄HCO₃ + 20% ACN (pH 8.2) produced the highest recovery rate of LMPP. To validate the recovery of cut off membrane (COM) obtained using the urea buffer system, 27 different 30 kDa COMs were used to prepare the LMPP sample which were then subjected to 1‐D SDS‐PAGE. Statistical analysis showed that the buffer system with COM produced a consistent the recovery of LMPP. In addition, 2‐DE analysis was also conducted to determine the relative intensity of each protein spot. When molecular weight ranges over 30 kDa and under 30 kDa were evaluated, 953 and 587 protein spots were observed in the gels, respectively, resulting in a total of 1540 protein spots being resolved. Identification of the major proteins were then performed using a nano‐LC/MS system comprised of an HPLC system and an ESI‐quadrupole IT MS equipped with a nano‐ESI source.     

Simulation of perturbation produced by an absorbing spherical body in collisionless plasma

A steady plasma state reached in the course of charging of an absorbing spherical body is found using computational methods. Numerical simulations provide complete information on this process, thereby allowing one to find the spatiotemporal dependences of the physical quantities and observe the kinetic phenomena accompanying the formation of stable electron and ion distributions in phase space. The distribution function of trapped ions is obtained, and their contribution to the screening of the charged sphere is determined. The sphere charge and the charge of the trapped-ion cloud are determined as functions of the unperturbed plasma parameters.     

Plasma proteomic analysis of patients infected with H1N1 influenza virus

This study profiled the plasma proteins of patients infected by the 2011 H1N1 influenza virus. Differential protein expression was identified in plasma obtained from noninfected control subjects (n = 15) and H1N1‐infected subjects (n = 15). Plasma proteins were separated by a 2DE large gel system and identified by nano‐ultra performance LC‐MS. Western blot assays were performed to validate proteins. Eight plasma proteins were upregulated and six proteins were downregulated among 3316 plasma proteins in the H1N1‐infected group as compared with the control group. Of 14 up‐ and downregulated proteins, nine plasma proteins were validated by Western blot analysis. Putative protein FAM 157A, leucine‐rich alpha 2 glycoprotein, serum amyloid A protein, and dual oxidase 1 showed significant differential expression. The identified plasma proteins could be potential candidates for biomarkers of H1N1 influenza viral infection. Further studies are needed to develop these proteins as diagnostic biomarkers.     

胶质瘤来源外泌体通过高迁移率族蛋白B1促进胶质瘤干细胞形成

摘要 目的：研究胶质瘤来源外泌体中高迁移率族蛋白B1（HMGB1）对胶质瘤干细胞形成的影响及其意义。方法：使用外泌体提取试剂盒提取原代胶质母细胞瘤来源外泌体,通过透射电子显微镜、纳米粒度电位仪和Western blotting对外泌体进行鉴定;采用Western blotting检测外泌体中HMGB1的表达量;通过qRT-PCR、Western blotting、克隆球计数检测外泌体对胶质瘤干细胞形成的影响;siRNA敲低HMGB1的表达水平,并通过qRT-PCR、Western blotting、克隆球计数检测外泌体中HMGB1对胶质瘤干细胞形成的影响。结果：原代胶质瘤细胞可以分泌外泌体到肿瘤微环境并且外泌体中存在HMGB1;原代胶质瘤细胞来源外泌体可以上调邻近胶质瘤细胞干性相关分子CD133、OCT4、NANOG、SOX2的表达并促进干细胞克隆球的形成;通过siRNA敲低原代胶质瘤细胞HMGB1的表达后,外泌体中HMGB1的含量降低并且外泌体促进胶质瘤干细胞形成的作用减弱。结论：胶质瘤细胞来源外泌体可以通过HMGB1促进胶质瘤干细胞的形成。     

Formation of potential titanium antigens based on protein binding to titanium dioxide nanoparticles

Degradation products of titanium implants include free ions, organo-metallic complexes, and particles, ranging from nano to macro sizes. The biological effects, especially of nanoparticles, is yet unknown. The main objective of this study was to develop Ti-protein antigens in physiological solutions that can be used in testing of cellular responses. For this purpose, 0.1% TiO2 nanoparticles less than 100 nm were mixed with human serum albumin (HSA), 0.1% and 1%, in cell culture medium (DMEM, pH 7.2). The Ti concentrations in the resulting solutions were analyzed by inductively coupled plasma mass spectrometry. The stability of the nanoparticles in suspension was analyzed by UV-vis spectrophotometer and Dynamic Light Scattering. The concentration of Ti in suspension was dependent on the presence and concentration of HSA. Albumin prevented high aggregation rate of TiO2 nanoparticles in cell culture medium. It is shown that nano TiO2-protein stable aggregates can be produced under physiological conditions at high concentrations, and are candidates for use in cellular tests.     

Approaches to the study of N-linked glycoproteins in human plasma using lectin affinity chromatography and nano-HPLC coupled to electrospray linear ion trap--Fourier transform mass spectrometry

In this publication, we will describe the combination of lectin affinity chromatography with nano high performance liquid chromatography (HPLC) coupled to a linear ion trap Fourier transform mass spectrometer (capillary LC-LTQ/FTMS) to characterize N-linked glycosylation structures in human plasma proteins. We used a well-characterized glycoprotein, tissue plasminogen activator (rt-PA), which is present at low levels in blood, as a standard to determine the dynamic range of this approach. N-linked glycopeptides derived from rt-PA could be characterized at a ratio of 1:200 in human plasma (rtPA: total plasma protein, w/w) by accurate mass measurement in the FTMS and fragmentation (MS(n)) in the linear ion trap. We demonstrated that this platform has the potential to characterize the general N-linked glycosylation structures of abundant glycoproteins present in human plasma without the requirement for antibody-based purification, or additional carbohydrate analytical protocols. This conclusion was supported by the determination of carbohydrate structures for three glycoproteins, IgG, haptoglobin, and alpha-1-acid glycoprotein, at their natural levels in a human plasma sample, but only after the lectin enrichment step.     

Boundary of the trapping region in the problem of disturbance of collisionless plasma by an absorbing sphere

The structure of the plasma disturbance near a spherical charged body is analyzed with allowance for the boundedness of the region of finite particle motion. The significance of the outer radius of the spherical region in which trapped particles can exist is demonstrated. The radius of the trapping sphere is determined by the boundary condition imposed on Poisson’s equation. The important role played by the boundary of the trapping region in the general analysis and solution of the problem is illustrated by simple examples.     

Effects of bio fertilizer and nano Zn-Fe oxide on physiological traits,antioxidant enzymes activity and yield of wheat (Triticum aestivum L.) under salinity stress

In order to evaluate the effects of nano Zn-Fe oxide and bio fertilizer on physiological traits, antioxidant activity and yield of wheat under salinity stress, a factorial experiment was conducted based on RCBD with three replications.Treatments were included salinity in three levels (no-salt, salinity 25 and 50 mM NaCl), four bio fertilizers levels (no bio fertilizer, seed inoculation by Azotobacter, Azosperilium, Pseudomonas) and nano oxide (without nano, application of nano Zn oxide, nano Fe oxide and nano Fe-Zn oxide 1.5 g/lit). Salinty stress decreased the chlorophyll-a, chlorophyll-b, total chlorophyll, photochemical efficiency of PSII and yield of wheat, whearas electrical conductivity, soluble sugars, proline content, and the activities of Catalase (CAT), Peroxidase (POD) and Polyphenol Oxidase (PPO) enzymes increased. Similar results were observed in CAT, POD and PPO activities due to inoculation by bio fertilizers and nano oxide. Maximum of soluble sugars and proline content were observed in the highest salinity level and application of Pseudomonas. Application of nano Zn-Fe oxide increased about 17.40% from grain yield in comparision with no application of nano oxide in the highest salinity level. Generally, it was conducted that bio fertilizer and nano oxide can be used as a proper tool for increasing wheat yield under salinity condition.     

Model of Solar Wind in the Heliosphere at Low and High Latitudes

The spatial distributions of the magnetic field, plasma density, and current at distances of (20–400)R_S from the Sun (where R_S is the solar radius) are investigated within a stationary axisymmetric MHD model of the solar wind (SW) at all latitudes in the inertial frame of reference with the origin at the center of the Sun. The model takes into account differential (with respect to the heliolatitude) rotation of the Sun and full corotation of plasma inside a boundary sphere of radius 20RS, which breaks down beyond this sphere. Self-consistent distributions of the plasma density, current, and magnetic field in the SW are obtained by numerically solving a set of time-independent MHD equations in spherical coordinates. It is demonstrated that the calculated results do not contradict observational data and describe a gradual transition from the fast SW at high heliolatitudes to the slow SW at low heliolatitudes, as well as the steepening of the profiles of the main SW characteristics with increasing distance from the Sun. The obtained dependences extend understanding of the SW structure at low and high latitudes and agree with the well-known Parker model in the limit of a small Ampère force.     

Material related aspects of surface structured endoprostheses

In this article technical problems of surface-structured endoprostheses for cementless implantation are discussed. On the basis of four prostheses (two hip and two knee endoprostheses) various different porous coating technologies are compared. One sintered sphere layer, a cast sphere layer, a cast layer with "spongy-bone" structure and a plasma sprayed coating were compared. The quality of the bonding between the prosthesis and the porous surface layer was examined metallographically using polished specimens, with additional investigation of fraction surfaces of special tension test specimens. Additional information is given on the notch effect of the different coatings, in terms of a reduction in fatigue strength. The notch sensitivity differs for each material, and the reduction in fatigue strength is discussed for different implant alloys and different technologies for surface structuring. The investigation shows that the present quality of surface-structured endoprostheses is not satisfactory. We would like to thank the Dr. Johannes Heidenhain Foundation for financial support of this research.     

改性纳米TiO2对蓝藻的生理生态影响

在自然光照条件和日光灯光照条件下,用掺1％Ag纳米TiO2、掺5％Fe2O3纳米TiO2、掺10％ZnO纳米TiO2和纯纳米TiO2对铜绿微囊藻（Synechocystis sp．）PCC6803和集胞藻（Microcystis aeruginosa）进行处理,并对2种藻样的叶绿素含量、类胡萝卜素含量、体外超氧自由基含量及超氧化物歧化酶（superoxidase dismutase,SOD）活性进行测定。结果表明,自然光照条件比日光灯光照条件更利于纳米材料光催化反应的进行;改性后的3种纳米材料对蓝藻的抑制效果要好于纯纳米TiO2,其中效果最好的为掺1％Ag纳米TiO2;2种藻样在适应由光催化剂引发光催化而产生的自由基胁迫时,集胞藻的适应能力比铜绿微囊藻更强。     

Nano photo scouring and nano photo bleaching of raw cellulosic fabric using nano TiO2

Photo catalytic action of nano TiO(2) for decomposing of some organic compounds is a well known phenomenon. This can be extended to the application on nano TiO(2) on the desized cotton fabric to decompose the hydrophobic impurities and coloring matters of the fabric. This can be nominating as a replacement for the conventional scouring and bleaching processes on cotton fabric producing the hydrophilic white cotton fabric. The photo activities of the nano TiO(2) on the desized cotton through decomposition of the cotton impurities compared for two different light exposures: UV rays and daylight. The desized cotton fabrics treated in the ultrasonic bath containing a colloidal aqueous solution of nano TiO(2)/citric acid (CA)/sodium hypophosphite (SHP). Incorporating CA in the treatment bath enhanced the treatment durability against washing, created a durable hydrophilic white cotton fabric even after several successive washings. Increasing the nano TiO(2) content enhanced the fabric hydrophilicity and whiteness features. Overall, the nano photo scouring and nano photo bleaching on the cotton fabric introduced and thoroughly discussed. This gains the application of nano TiO(2) on textile materials besides the other well known characteristics obtained on the textiles including self-cleaning, antibacterial and UV protection.     

Comparative study on the responses of broiler chicken to hot and humid environment supplemented with different dietary levels and sources of selenium

Present study was carried out with the objective of investigating the role of green synthesized nano Se (GNS) in growth performance, digestibility of minerals, immunity, stress alleviation, antioxidant status, and body Se content of broiler chicken raised under hot and humid environment with respect to market nano Se (MNS) and inorganic Se. The experimental design was 3 × 3 factorial, in which three levels (0.15, 0.20, and 0.25 ppm) and three sources (inorganic, green nano, and market nano) of Se resulted in nine treatments viz. IS-0.15, GNS-0.15, MNS-0.15, IZ-0.20, GNS-0.20, MNS-0.20, IS-0.25, GNS-0.25, and MNS-0.25 (IS: inorganic Se, GNS: green nano Se, MNS: market nano Se). A total of 432 broiler chicken were divided among nine treatments with six replicates of birds per treatment (8 birds/replicate). Results of present study revealed significantly better growth performance of birds supplemented with 0.25 ppm nano Se. The supplementation of 0.25 ppm nano Se improved the immune response and lymphoid organ development of birds. Significantly higher Se and nitrogen digestibility coefficients, serum antioxidant activity and decline of Heterophil: Lymphocyte ratio and expression of HSP70 gene were observed in birds supplemented with 0.25 ppm Se and nano source of Se compared to inorganic Se. Significantly higher Se concentration in liver and breast muscle and higher serum Se concentration were observed in birds fed 0.25 ppm nano Se. The liver Se concentration was much higher than that of breast muscle. However, the nano Se synthesized by green method in this study did not differ significantly from the chemically synthesized nano Se. It was concluded that 0.25 ppm Se and nano form of Se are superior to lower levels and inorganic form of Se, respectively, in improving the immunity, growth, antioxidant status, and in stress alleviation of broiler chicken. However, GNS is equally efficient as chemically synthesized MNS.     

Formulation of Statistical Equation of Motion of Blood

A general form of the statistical equation of motion of the blood is derived by averaging the motion of individual elements of the blood over a small volume in space. This equation can be transformed into an explicit form to find the constitutive equations of the blood provided the detailed motion of the plasma in some neighborhood of a suspended particle is known. As a demonstration of such transformation, the general form of the statistical equation of motion is applied to the suspension of sphere with a very low concentration to find the effective viscosity.     

CARD-FISH技术及其在微生物生态学研究中的应用

催化报告沉积荧光原位杂交技术(Catalyzed reporter deposition-fluorescence in situ hybridization,CARDFISH)是基于传统的FISH技术发展而来,由于其较高的灵敏度及稳定性,可以检测微生物的rRNA、mRNA和DNA上的目标基因等,获得环境微生物的群落及功能信息,现已成为微生物生态学研究领域中的重要技术手段。近些年,CARD-FISH与同位素示踪技术、纳米二次离子质谱技术(Nano SIMS)、扫描电子显微镜(SEM)、流式细胞仪等技术方法的联合使用,不仅可以研究复杂环境中微生物的物种组成、数量及其高分辨形态学信息,而且可以获得微生物在单细胞水平的生理代谢信息及其活性,对在单细胞水平认识原位环境微生物的生理生态功能具有重要意义。本文重点介绍了CARD-FISH的技术路线和要点,并探讨CARD-FISH与相关技术联用在环境微生物生态学研究中的应用及进展。     

Development of the discharge apparatus in the fungus Entophlyctis

Correlative light and electron microscopic observations were used to reconstruct the morphological events involved in the development of the discharge apparatus of Entophlyctis zoosporangia. A discharge plug formed as vesicles containing fibrillar material fused with the plasma membrane and deposited their matrices between the plasma membrane and zoosporangial wall. At the apex of the enlarging plug, the zoosporangial wall lost its microfibrillar appearance, became diffuse, and left an inoperculate discharge pore. The discharge plug exuded through this pore and then expanded into a sphere which rested at the tip of the discharge papilla or tube. After the release of the discharge plug, the number of fibrilla containing vesicles decreased and abundant endoplasmic reticulum appeared in the cytoplasm below the plug. Granular material then accumulated at the interface of the discharge plug and the plasma membrane. This was the endo-operculum. A single layer of endoplasmic reticulum subtended the area of plasma membrane which the endo-operculum covered. Later, dictyosomes appeared in the cytoplasm below the endo-operculum. Fusion of Golgi vesicles with the plasma membrane below the endo-operculum coincided with the initiation of cytoplasmic cleavage. This sequence of events indicates that, unlike the discharge plug, the endo-operculum does not originate by vesicular addition of preformed material.