WorldWideScience

Sample records for biological ion concentration

  1. Ion climate and radon concentration

    International Nuclear Information System (INIS)

    Busbarna, L.

    1981-01-01

    Characteristic values of radon concentration in natural ion climate and in open air were compared and the effect of artificially produced negative ion excess on the radon concentration of air was studied. The results show that the radon concentration measurable at the rise of negative ion excess is smaller than that in the case of natural equilibrium. This effect can be utilized lowering the background of the scintillation chambers, thus increasing their sensitivity. The negative ions of the artificial ion climate lower radon concentration in closed space. The question arises whether only the ion climate is responsible for the effects on the organism and on the nervous system or the radon concentration of the air also contributes to them. (author)

  2. Hip implants - Paper VI - Ion concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Sargeant, A. [Department of Biological Sciences, Ohio Northern University, Ada, OH 45810 (United States); Goswami, T. [Department of Mechanical Engineering, Ohio Northern University, Ada, OH 45810 (United States)]. E-mail: t-goswami@onu.edu

    2007-07-01

    Total hip-joint arthroplasty is performed in increasing numbers where it translates to about 0.16-0.2% of population per year in industrial countries. In most cases, an implant is a metallic component articulating with a metal, ceramic or poly-ethylene liner as seen in the case of hip, knee and spine. The metal implants release ions in vivo. Therefore, there is a need to study metallic implants and ions released as a result. Toxic concentrations of ions can lead to many adverse physiological effects, including cytotoxicity, genotoxicity, carcinogenicity, and metal sensitivity. There is a need to map ion concentrations establishing boundaries between normal and toxic levels; which however, does not exist. Reference levels of ion concentrations in body fluids and tissues determined by many studies are compiled, reviewed, and presented in this paper. The concentrations of ions released from different alloys, including cobalt, chromium, nickel, molybdenum titanium, aluminum, and vanadium, are presented in this paper. This paper reviews the literature pertaining to clinical data on metal ion concentrations in patients with metal joint prostheses, and laboratory data on the physiological effects of the metals.

  3. Ion-ion Recombination and Chemiion Concentrations In Aircraft Exhaust

    Science.gov (United States)

    Turco, R. P.; Yu, F.

    Jet aircraft emit large quantities of ultrafine volatile aerosols, as well as soot parti- cles, into the environment. To determine the long-term effects of these emissions, a better understanding of the mechanisms that control particle formation and evolution is needed, including the number and size dispersion. A recent explanation for aerosol nucleation in a jet wake involves the condensation of sulfuric acid vapor, and cer- tain organic compounds, onto charged molecular clusters (chemiions) generated in the engine combustors (Yu and Turco, 1997). Massive charged aggregates, along with sulfuric acid and organic precursor vapors, have been detected in jet plumes under cruise conditions. In developing the chemiion nucleation theory, Yu and Turco noted that ion-ion recombination in the engine train and jet core should limit the chemiion emission index to 1017/kg-fuel. This value is consistent with ion-ion recombination coefficients of 1×10-7 cm3/s over time scales of 10-2 s. However, the evolution of the ions through the engine has not been adequately studied. The conditions at the combustor exit are extreme-temperatures approach 1500 K, and pressures can reach 30 atmospheres. In this presentation, we show that as the combustion gases expand and cool, two- and three-body ion-ion recombination processes control the chemiion concentration. The concepts of mutual neutralization and Thomson recombination are first summarized, and appropriate temperature and pressure dependent recombination rate coefficients are derived for the aircraft problem. A model for ion losses in jet exhaust is then formulated using an "invariance" principle discussed by Turco and Yu (1997) in the context of a coagulating aerosol in an expanding plume. This recombina- tion model is applied to estimate chemiion emission indices for a range of operational engine conditions. The predicted ion emission rates are found to be consistent with observations. We discuss the sources of variance in chemiion

  4. Biologically produced sulfur particles and polysulfide ions

    NARCIS (Netherlands)

    Kleinjan, W.E.

    2005-01-01

    This thesis deals with the effects of particles of biologically produced sulfur (or 'biosulfur') on a biotechnological process for the removal of hydrogen sulfide from gas streams. Particular emphasis is given to the role of polysulfide ions in such a process. These

  5. Direct seawater desalination by ion concentration polarization

    Science.gov (United States)

    Kim, Sung Jae; Ko, Sung Hee; Kang, Kwan Hyoung; Han, Jongyoon

    2010-04-01

    A shortage of fresh water is one of the acute challenges facing the world today. An energy-efficient approach to converting sea water into fresh water could be of substantial benefit, but current desalination methods require high power consumption and operating costs or large-scale infrastructures, which make them difficult to implement in resource-limited settings or in disaster scenarios. Here, we report a process for converting sea water (salinity ~500 mM or ~30,000 mg l-1) to fresh water (salinity water is divided into desalted and concentrated streams by ion concentration polarization, a phenomenon that occurs when an ion current is passed through ion-selective membranes. During operation, both salts and larger particles (cells, viruses and microorganisms) are pushed away from the membrane (a nanochannel or nanoporous membrane), which significantly reduces the possibility of membrane fouling and salt accumulation, thus avoiding two problems that plague other membrane filtration methods. To implement this approach, a simple microfluidic device was fabricated and shown to be capable of continuous desalination of sea water (~99% salt rejection at 50% recovery rate) at a power consumption of less than 3.5 Wh l-1, which is comparable to current state-of-the-art systems. Rather than competing with larger desalination plants, the method could be used to make small- or medium-scale systems, with the possibility of battery-powered operation.

  6. Biological treatment of inorganic ion contamination including radionuclides

    International Nuclear Information System (INIS)

    Cherry, R.S.

    1997-01-01

    Microorganisms and plants are capable of a broad range of activities useful in treating inorganic contaminants in soil, groundwater, and surface runoff water Among the advantages of biological processes for this purpose are relatively low costs (related to their mild conditions) and the practicality of letting them run unattended. This talk will review both kinds of treatment chemistry that can be done biologically as well as present data from INEEL projects on bioremediation of specific elements. Biological processes can either solubilize or immobilize metals and other ions depending on the need. Uranium ions are solubilized from soil by the local bioproduction of organic acids as chelating agents, allowing removal of this ion as part of an ex-situ treatment process. Further, the microbial production of sulfuric acid can be used to solubilize Cs contamination in concrete surfaces. More usual though is the need to control metal movement in soil or water. Various metals such as Se and Cd are taken up from soil by hyper-accumulating plants, where they can be harvested in concentrated form in the leaves and stems. Excess acidity and a broad variety of toxic metals in acid rock drainage, such as Hg, Cd, Zn and others, can be removed by the production of sulfide ion in an easily fielded biological reactor which may be useful on phosphate processing runoff water contaminated with naturally occuring radioactive materials. Soluble Co, Cu, and Cd can be treated by sorption onto immobilized algae. Inorganic ions can also be directly reduced by bacteria as part of treatment, for example the conversion of soluble selenate ion to insoluble elemental selenium and the conversion of highly toxic CR(VI) to the far less soluble and less toxic Cr(III)

  7. Biological treatment of inorganic ion contamination including radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Cherry, R S [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

    1997-12-01

    Microorganisms and plants are capable of a broad range of activities useful in treating inorganic contaminants in soil, groundwater, and surface runoff water Among the advantages of biological processes for this purpose are relatively low costs (related to their mild conditions) and the practicality of letting them run unattended. This talk will review both kinds of treatment chemistry that can be done biologically as well as present data from INEEL projects on bioremediation of specific elements. Biological processes can either solubilize or immobilize metals and other ions depending on the need. Uranium ions are solubilized from soil by the local bioproduction of organic acids as chelating agents, allowing removal of this ion as part of an ex-situ treatment process. Further, the microbial production of sulfuric acid can be used to solubilize Cs contamination in concrete surfaces. More usual though is the need to control metal movement in soil or water. Various metals such as Se and Cd are taken up from soil by hyper-accumulating plants, where they can be harvested in concentrated form in the leaves and stems. Excess acidity and a broad variety of toxic metals in acid rock drainage, such as Hg, Cd, Zn and others, can be removed by the production of sulfide ion in an easily fielded biological reactor which may be useful on phosphate processing runoff water contaminated with naturally occuring radioactive materials. Soluble Co, Cu, and Cd can be treated by sorption onto immobilized algae. Inorganic ions can also be directly reduced by bacteria as part of treatment, for example the conversion of soluble selenate ion to insoluble elemental selenium and the conversion of highly toxic CR(VI) to the far less soluble and less toxic Cr(III).

  8. Studying of ion implantation effect on the biology in China

    International Nuclear Information System (INIS)

    Yu Zengliang

    1993-04-01

    Since low energy ion effect on the biology was observed, the ion implantation as a new mutagenic source has been widely used in improving crops and modifying microbes in China. The basic phenomenon of ion implantation effect on the biology and analytical results are reported, and the examples of its application and its further development are shown

  9. Ion Concentration- and Voltage-Dependent Push and Pull Mechanisms of Potassium Channel Ion Conduction.

    Directory of Open Access Journals (Sweden)

    Kota Kasahara

    Full Text Available The mechanism of ion conduction by potassium channels is one of the central issues in physiology. In particular, it is still unclear how the ion concentration and the membrane voltage drive ion conduction. We have investigated the dynamics of the ion conduction processes in the Kv1.2 pore domain, by molecular dynamics (MD simulations with several different voltages and ion concentrations. By focusing on the detailed ion movements through the pore including selectivity filter (SF and cavity, we found two major conduction mechanisms, called the III-IV-III and III-II-III mechanisms, and the balance between the ion concentration and the voltage determines the mechanism preference. In the III-IV-III mechanism, the outermost ion in the pore is pushed out by a new ion coming from the intracellular fluid, and four-ion states were transiently observed. In the III-II-III mechanism, the outermost ion is pulled out first, without pushing by incoming ions. Increases in the ion concentration and voltage accelerated ion conductions, but their mechanisms were different. The increase in the ion concentrations facilitated the III-IV-III conductions, while the higher voltages increased the III-II-III conductions, indicating that the pore domain of potassium channels permeates ions by using two different driving forces: a push by intracellular ions and a pull by voltage.

  10. Air ion concentrations in various urban outdoor environments

    Science.gov (United States)

    Ling, Xuan; Jayaratne, Rohan; Morawska, Lidia

    2010-06-01

    Atmospheric ions are produced by many natural and anthropogenic sources and their concentrations vary widely between different environments. There is very little information on their concentrations in different types of urban environments, how they compare across these environments and their dominant sources. In this study, we measured airborne concentrations of small ions, particles and net particle charge at 32 different outdoor sites in and around a major city in Australia and identified the main ion sources. Sites were classified into seven groups as follows: park, woodland, city centre, residential, freeway, power lines and power substation. Generally, parks were situated away from ion sources and represented the urban background value of about 270 ions cm -3. Median concentrations at all other groups were significantly higher than in the parks. We show that motor vehicles and power transmission systems are two major ion sources in urban areas. Power lines and substations constituted strong unipolar sources, while motor vehicle exhaust constituted strong bipolar sources. The small ion concentration in urban residential areas was about 960 cm -3. At sites where ion sources were co-located with particle sources, ion concentrations were inhibited due to the ion-particle attachment process. These results improved our understanding on air ion distribution and its interaction with particles in the urban outdoor environment.

  11. Concentrations of ions in blood or athletes using NAA

    International Nuclear Information System (INIS)

    Kovacs, Luciana; Zamboni, Cibele B.; Loureno, Thiago F.; Nunes, Lazaro A.S.; Macedo, Denise V.

    2011-01-01

    Sodium (Na), chlorine (Cl) and potassium (K) are widely distributed in the body and are the mainly of body fluids electrolytes. K is the major intracellular ion. Na and Cl are the major extracellular ions. Therefore, Na and Cl can be regarded as the most important osmotically active electrolytes. The concentrations of these ions in body fluids are very tightly controlled. These electrolytes play central roles in electrolytic balances and current, in osmotic control, in the transport of organic metabolites by cells, and stabilization of poly electrolytes in cells. In this study Na, Cl and K levels were investigated in blood of athletes submitted to physical exercise at Laboratorio de Bioquimica do Exercicio (LABEX/UNICAMP - Brazil) using Neutron Activation Analyses (NAA) technique. The blood samples were collected from six male athletes, ranging from 18 to 26 years old, before and after the physical training. These results were compared with the rest condition (before start the physical exercise), as well as with the control group (subjects of same age but not involved with physical activities), for checking the performance of the athletes during and after the exercise. The nuclear procedure adopted as NAA, it can be an alternative procedure to perform biochemistry analyses in blood, mainly when the biological material is scarce. (author)

  12. Influence of temperature and ion concentration on sedimentation ...

    African Journals Online (AJOL)

    TSP sedimentation order also ranged between 0.58 and 1.31 at constant phosphate ions concentration and between 1.55 and 1.81 at constant strontium ions concentration. ... Data may be employed as additional design information for modeling physiochemical phosphate removal in water treatment technology. Keywords: ...

  13. Heavy ion induced DNA transfer in biological cells

    International Nuclear Information System (INIS)

    Vilaithong, T.; Yu, L.D.; Apavatjrut, P.; Phanchaisri, B.; Sangyuenyongpipat, S.; Anuntalabhochai, S.; Brown, I.G.

    2004-01-01

    Low-energy ion beam bombardment of biological materials for genetic modification purposes has experienced rapid growth in the last decade, particularly for the direct DNA transfer into living organisms including both plants and bacteria. Attempts have been made to understand the mechanisms involved in ion-bombardment-induced direct gene transfer into biological cells. Here we summarize the present status of the application of low-energy ions for genetic modification of living sample materials

  14. Biological effects of accelerated boron, carbon, and neon ions

    International Nuclear Information System (INIS)

    Grigoryev, Yu.G.; Ryzhov, N.I.; Popov, V.I.

    1975-01-01

    The biological effects of accelerated boron, carbon, and neon ions on various biological materials were determined. The accelerated ions included 10 B, 11 B, 12 C, 20 Ne, 22 Ne, and 40 Ar. Gamma radiation and x radiation were used as references in the experiments. Among the biological materials used were mammalian cells and tissues, yeasts, unicellular algae (chlorella), and hydrogen bacteria. The results of the investigation are given and the biophysical aspects of the problem are discussed

  15. Detection of chloride ion concentration using chronopotentiometry

    NARCIS (Netherlands)

    Abbas, Yawar; Olthuis, Wouter; van den Berg, Albert

    2013-01-01

    In this paper, a novel approach is reported for the electrochemical measurement of chloride ions using chronopotentiometry. A current pulse is applied at the Ag/AgCl working electrode and the potential change is measured with respect to another identical Ag/AgCl electrode in the bulk electrolyte.

  16. Biological Membrane Ion Channels Dynamics, Structure, and Applications

    CERN Document Server

    Chung, Shin-Ho; Krishnamurthy, Vikram

    2007-01-01

    Ion channels are biological nanotubes that are formed by membrane proteins. Because ion channels regulate all electrical activities in living cells, understanding their mechanisms at a molecular level is a fundamental problem in biology. This book deals with recent breakthroughs in ion-channel research that have been brought about by the combined effort of experimental biophysicists and computational physicists, who together are beginning to unravel the story of these exquisitely designed biomolecules. With chapters by leading experts, the book is aimed at researchers in nanodevices and biosensors, as well as advanced undergraduate and graduate students in biology and the physical sciences. Key Features Presents the latest information on the molecular mechanisms of ion permeation through membrane ion channels Uses schematic diagrams to illustrate important concepts in biophysics Written by leading researchers in the area of ion channel investigations

  17. Quantum Interference and Selectivity through Biological Ion Channels.

    Science.gov (United States)

    Salari, Vahid; Naeij, Hamidreza; Shafiee, Afshin

    2017-01-30

    The mechanism of selectivity in ion channels is still an open question in biology for more than half a century. Here, we suggest that quantum interference can be a solution to explain the selectivity mechanism in ion channels since interference happens between similar ions through the same size of ion channels. In this paper, we simulate two neighboring ion channels on a cell membrane with the famous double-slit experiment in physics to investigate whether there is any possibility of matter-wave interference of ions via movement through ion channels. Our obtained decoherence timescales indicate that the quantum states of ions can only survive for short times, i.e. ≈100 picoseconds in each channel and ≈17-53 picoseconds outside the channels, giving the result that the quantum interference of ions seems unlikely due to environmental decoherence. However, we discuss our results and raise few points, which increase the possibility of interference.

  18. Biological effect of penetration controlled irradiation with ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Atsushi; Shimizu, Takashi; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Watanabe, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Yamashita, Takao

    1997-03-01

    To investigate the effect of local irradiation with ion beams on biological systems, technique for penetration controlled irradiation has been established. The range in a target was controlled by changing the distance from beam window in the atmosphere, and could be controlled linearly up to about 31 {mu}m in biological material. In addition, the effects of the penetration controlled irradiations with 1.5 MeV/u C and He ions were examined using tobacco pollen. The increased frequency of leaky pollen produced by ion beams suggests that the efficient pollen envelope damages would be induced at the range-end of ion beams. (author)

  19. Variability of air ion concentrations in urban Paris

    Science.gov (United States)

    Dos Santos, V. N.; Herrmann, E.; Manninen, H. E.; Hussein, T.; Hakala, J.; Nieminen, T.; Aalto, P. P.; Merkel, M.; Wiedensohler, A.; Kulmala, M.; Petäjä, T.; Hämeri, K.

    2015-12-01

    Air ion concentrations influence new particle formation and consequently the global aerosol as potential cloud condensation nuclei. We aimed to evaluate air ion concentrations and characteristics of new particle formation events (NPF) in the megacity of Paris, France, within the MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric Pollution and climate effects, and Integrated tools for assessment and mitigation) project. We measured air ion number size distributions (0.8-42 nm) with an air ion spectrometer and fine particle number concentrations (> 6 nm) with a twin differential mobility particle sizer in an urban site of Paris between 26 June 2009 and 4 October 2010. Air ions were size classified as small (0.8-2 nm), intermediate (2-7 nm), and large (7-20 nm). The median concentrations of small and large ions were 670 and 680 cm-3, respectively, (sum of positive and negative polarities), whereas the median concentration of intermediate ions was only 20 cm-3, as these ions were mostly present during new particle formation bursts, i.e. when gas-to-particle conversion produced fresh aerosol particles from gas phase precursors. During peaks in traffic-related particle number, the concentrations of small and intermediate ions decreased, whereas the concentrations of large ions increased. Seasonal variations affected the ion population differently, with respect to their size and polarity. NPF was observed in 13 % of the days, being most frequent in spring and late summer (April, May, July, and August). The results also suggest that NPF was favoured on the weekends in comparison to workdays, likely due to the lower levels of condensation sinks in the mornings of weekends (CS weekdays 09:00: 18 × 10-3 s-1; CS weekend 09:00: 8 × 10-3 s-1). The median growth rates (GR) of ions during the NPF events varied between 3 and 7 nm h-1, increasing with the ion size and being higher on workdays than on weekends for intermediate and large ions. The median GR of

  20. determination of serum chloride ion concentration in pregnant

    African Journals Online (AJOL)

    Yusif

    ABSTRACT. Serum chloride ion level in blood samples of pregnant women attending ante-natal care clinic in Minjibir was investigated. The mean and standard deviation of the ion in the samples is 100.51+ 4.89mmol/L. The distribution is skewed towards high frequency of low concentrations and could be attributed to.

  1. Effects of ion concentration on the hydrogen bonded structure of ...

    Indian Academy of Sciences (India)

    WINTEC

    Effects of ion concentration on the hydrogen bonded structure of water in the vicinity of ions in aqueous NaCl solutions. A NAG. 1. , D CHAKRABORTY and A CHANDRA*. Department of Chemistry, Indian Institute of Technology, Kanpur 208 016. 1. Present address: Department of Chemistry and Chemical Engineering,.

  2. Measurements of ion concentration in gasoline and diesel engine exhaust

    Science.gov (United States)

    Yu, Fangqun; Lanni, Thomas; Frank, Brian P.

    The nanoparticles formed in motor vehicle exhaust have received increasing attention due to their potential adverse health effects. It has been recently proposed that combustion-generated ions may play a critical role in the formation of these volatile nanoparticles. In this paper, we design an experiment to measure the total ion concentration in motor vehicle engine exhaust, and report some preliminary measurements in the exhaust of a gasoline engine (K-car) and a diesel engine (diesel generator). Under the experimental set-up reported in this study and for the specific engines used, the total ion concentration is ca. 3.3×10 6 cm -3 with almost all of the ions smaller than 3 nm in the gasoline engine exhaust, and is above 2.7×10 8 cm -3 with most of the ions larger than 3 nm in the diesel engine exhaust. This difference in the measured ion properties is interpreted as a result of the different residence times of exhaust inside the tailpipe/connecting pipe and the different concentrations of soot particles in the exhaust. The measured ion concentrations appear to be within the ranges predicted by a theoretical model describing the evolution of ions inside a pipe.

  3. Biological effect of nitrogen ion implantation on stevia

    International Nuclear Information System (INIS)

    Wang Cailian; Shen Mei; Chen Qiufang; Shu Shizhen

    1997-10-01

    Dry seed of stevia were implanted by 35∼150 keV nitrogen ions with various doses. The biological effect in M 1 was studied. The results showed that nitrogen ion beam was able to induce variation on chromosome structure in root tip cells. The rate of cells with chromosome aberration was increased with ion beam energy and dose added, but there was on significant linear regression relationship between ion dose and aberration rate. The results indicated the seedling height reduced with the increasing of dose for ion beam. The biological effect of nitrogen ion beam on M 1 stevia was lower than that of γ-rays. (6 refs., 1 fig., 4 tabs.)

  4. Capillary Ion Concentration Polarization for Power-Free Salt Purification

    Science.gov (United States)

    Park, Sungmin; Jung, Yeonsu; Cho, Inhee; Kim, Ho-Young; Kim, Sung Jae

    2014-11-01

    In this presentation, we experimentally and theoretically demonstrated the capillary based ion concentration polarization for power-free salt purification system. Traditional ion concentration polarization phenomenon has been studied for a decade for both fundamental nanoscale fluid dynamics and novel engineering applications such as desalination, preconcentration and energy harvesting devices. While the conventional system utilizes an external power source, the system based on capillary ion concentration polarization is capable of perm-selective ion transportation only by capillarity so that the same ion depletion zone can be formed without any external power sources. An ion concentration profile near the nanostructure was tracked using fluorescent probes and analyzed by solving the modified Nernst-Planck equation. As a result, the concentration in the vicinity of the nanostructure was at least 10 times lower than that of bulk electrolyte and thus, the liquid absorbed into the nanostructure had the low concentration. This mechanism can be used for the power free salt purification system which would be significantly useful in underdeveloped and remote area. This work was supported by Samsung Research Funding Center of Samsung Electronics under Project Number SRFC-MA1301-02.

  5. Procedure for reducing hydrogen ion concentration in acidic anion eluate

    International Nuclear Information System (INIS)

    Parobek, P.; Baloun, S.; Plevac, S.

    1992-01-01

    A procedure is suggested for reducing the concentration of hydrogen ions in the acidic anionic eluate formed during the separation of uranium. The procedure involves anex elution, precipitation, filtration, precipitate rinsing, and anex rinsing. The procedure is included in the uranium elution process and requires at least one ion exchanger column and at least one tank in the continuous or discontinuous mode. Sparing the neutralizing agent by reducing the hydrogen ion concentration in the acidic anionic eluate is a major asset of this procedure. (Z.S.). 1 fig

  6. Ion beam modification of biological materials in nanoscale

    Science.gov (United States)

    Yu, L. D.; Anuntalabhochai, S.

    2012-07-01

    Ion interaction with biological objects in nanoscale is a novel research area stemming from applications of low-energy ion beams in biotechnology and biomedicine. Although the ion beam applications in biotechnology and biomedicine have achieved great successes, many mechanisms remain unclear and many new applications are to be explored. We have carried out some research on exploring the mechanisms and new applications besides attaining ion beam induction of mutation breeding and gene transformation. In the studies on the mechanisms, we focused our investigations on the direct interaction in nanoscale between ions and biological living materials. Our research topics have included the low-energy ion range in DNA, low-energy ion or neutral beam bombardment effect on DNA topological form change and mutation, low-energy ion or neutral beam bombardment effect on the cell envelope and gene transformation, and molecular dynamics simulation of ultra-low-energy ion irradiation of DNA. In the exploration of new applications, we have started experiments on ion irradiation or bombardment, in the nanoscaled depth or area, of human cells for biomedical research. This paper introduces our experiments and reports interesting results.

  7. Ion beam modification of biological materials in nanoscale

    International Nuclear Information System (INIS)

    Yu, L.D.; Anuntalabhochai, S.

    2012-01-01

    Ion interaction with biological objects in nanoscale is a novel research area stemming from applications of low-energy ion beams in biotechnology and biomedicine. Although the ion beam applications in biotechnology and biomedicine have achieved great successes, many mechanisms remain unclear and many new applications are to be explored. We have carried out some research on exploring the mechanisms and new applications besides attaining ion beam induction of mutation breeding and gene transformation. In the studies on the mechanisms, we focused our investigations on the direct interaction in nanoscale between ions and biological living materials. Our research topics have included the low-energy ion range in DNA, low-energy ion or neutral beam bombardment effect on DNA topological form change and mutation, low-energy ion or neutral beam bombardment effect on the cell envelope and gene transformation, and molecular dynamics simulation of ultra-low-energy ion irradiation of DNA. In the exploration of new applications, we have started experiments on ion irradiation or bombardment, in the nanoscaled depth or area, of human cells for biomedical research. This paper introduces our experiments and reports interesting results.

  8. Assessing toxicity of varying major ion concentrations to marine organisms

    International Nuclear Information System (INIS)

    Mount, D.R.; Quast, W.

    1993-01-01

    Recent regulatory developments have required that produced waters discharged in the Gulf of Mexico be monitored for toxicity to marine organisms. While produced water may contain a variety of indigenous and introduced chemicals, virtually all have moderate to high concentrations of major ions. Although seawater is also rich in these ions, excessive salinity can cause toxicity to marine organisms. Perhaps more importantly, toxicity to marine organisms can be caused by deviations from normal ion ratios even if the total salinity is within organism tolerances. To provide a better understanding of marine organism responses to variations in major ion concentrations, the authors conducted a series of laboratory experiments to quantify the responses of mysid shrimp (Mysidopsis bahia) and sheepshead minnows (Cyprinodon variegatus) to modifications of normal seawater chemistry. Acute testing included both increasing and decreasing the concentrations of individual ions relative to seawater, as well as altering total salinity. Results show these organisms can be adversely affected by this altered chemistry and their sensitivity is dependent upon the individual ions that are manipulated. Results from these studies are being incorporated into an overall strategy for evaluating the influence of major ion chemistry on produced water toxicity tests

  9. Heavy metal ion removal by adsorption on to biological materials

    International Nuclear Information System (INIS)

    Jansson-Charrier, M.; Guibal, E.; Le Cloirec, P.; Surjous, R.

    1994-01-01

    The development of regulations constraints in the industrial waste-waters management leads to the study of new treatment processes, using raw or functionalized biological materials. These processes show competitive performances in metal ion sorption efficiency for the low metal content effluents. Uptake capacities of Uranium as high as 400 mg.g -1 chitosan, equivalent to the double of the uptake capacity of fungal origin biomass, can be reached. The application of these processes to real mine wastewaters gives efficiency coefficient upper to 90%, the residual concentrations are compatible to a direct injection into the environment. The grafting of functional groups onto the chitosan scales up the sorption performances to uptake capacity upper than 600 mg.g -1 polymer. pH, metal concentration are cited as major parameters, particle size influences both uptake kinetics and sorption equilibrium, in the case of the uranium accumulation by chitosan. The desorption of uranium from the sorbent allows the valorization of uranium and the re-use of the sorbent. (authors). 21 refs., 10 figs

  10. Ion-exchange concentration of inorganic anions from aqueous solution

    Directory of Open Access Journals (Sweden)

    L. P. Bondareva

    2016-01-01

    Full Text Available Monitoring of natural waters in the present time - consuming process, the accuracy of which is influenced by many factors: the composition of water, the presence of impurities and "interfering" components. The water sample preparation process includes the step of concentration and separation of ions determined. The most versatile, efficient, and frequently used method is the concentration of inorganic anions from aqueous solutions by ion exchanger, which can optimize the composition of water to the optimal for identification and quantitative determination of anions. The characteristics of sorption chloride, nitrate and sulfate ions of basic anion exchange resin AВ-17 and Purolite A430 were compared in the article. The constants of protolysis of ion exchangers both AB 17 and Purolite A430 are the same and equal 0.037 ± 0,002. The value of total capacity (POE Purolite A430 was 4.3 mmol/g, AB 17 – 3.4 mmol/g. The studied ion exchangers have the same type of ionic groups – quaternary ammonium, but their number and denotes differ. The number of quaternary ammonium groups is higher in Purolite A430, respectively the number of absorbed anions of these ion exchanger is higher. The values of dynamic exchange capacity (DOE of ion exchanger Purolite A430 is higher than these values of AB-17 and equal to 1.48 ± 0.03 mmol / dm3 for chloride ion, 1.50 ± 0.03 mmol / dm3 for nitrate ion, 1.62 ± 0.03 mmol / dm3 for sulfate ion. The values of the POE and DOE of anion-exchange resins Purolite A430 and AV-17 and the characteristics of the individual sorption of chloride, nitrate, sulfate ions showed an advantage of the Purolite for the concentrationing of anions. It is found that times of anions sorption from triple-anion solutions by Purolite A430 are significantly different for different anions, and these times are close for anion-exchanger AV-17. It proves the possibility of quantitative separation and concentration by anion-exchanger Purolite A430.

  11. Methods for obtaining a uniform volume concentration of implanted ions

    International Nuclear Information System (INIS)

    Reutov, V.F.

    1995-01-01

    Three simple practical methods of irradiations with high energy particles providing the conditions for obtaining a uniform volume concentration of the implanted ions in the massive samples are described in the present paper. Realization of the condition of two-sided irradiation of a plane sample during its rotation in the flux of the projectiles is the basis of the first method. The use of free air as a filter with varying absorbent ability due to movement of the irradiated sample along ion beam brought to the atmosphere is at the basis of the second method of uniform ion alloying. The third method for obtaining a uniform volume concentration of the implanted ions in a massive sample consists of irradiation of a sample through the absorbent filter in the shape of a foil curved according to the parabolic law moving along its surface. The first method is the most effective for obtaining a great number of the samples, for example, for mechanical tests, the second one - for irradiation in different gaseous media, and the third one - for obtaining high concentrations of the implanted ions under controlled (regulated) thermal and deformation conditions. 2 refs., 7 figs

  12. Electrodiffusive model for astrocytic and neuronal ion concentration dynamics.

    Directory of Open Access Journals (Sweden)

    Geir Halnes

    Full Text Available The cable equation is a proper framework for modeling electrical neural signalling that takes place at a timescale at which the ionic concentrations vary little. However, in neural tissue there are also key dynamic processes that occur at longer timescales. For example, endured periods of intense neural signaling may cause the local extracellular K(+-concentration to increase by several millimolars. The clearance of this excess K(+ depends partly on diffusion in the extracellular space, partly on local uptake by astrocytes, and partly on intracellular transport (spatial buffering within astrocytes. These processes, that take place at the time scale of seconds, demand a mathematical description able to account for the spatiotemporal variations in ion concentrations as well as the subsequent effects of these variations on the membrane potential. Here, we present a general electrodiffusive formalism for modeling of ion concentration dynamics in a one-dimensional geometry, including both the intra- and extracellular domains. Based on the Nernst-Planck equations, this formalism ensures that the membrane potential and ion concentrations are in consistency, it ensures global particle/charge conservation and it accounts for diffusion and concentration dependent variations in resistivity. We apply the formalism to a model of astrocytes exchanging ions with the extracellular space. The simulations show that K(+-removal from high-concentration regions is driven by a local depolarization of the astrocyte membrane, which concertedly (i increases the local astrocytic uptake of K(+, (ii suppresses extracellular transport of K(+, (iii increases axial transport of K(+ within astrocytes, and (iv facilitates astrocytic relase of K(+ in regions where the extracellular concentration is low. Together, these mechanisms seem to provide a robust regulatory scheme for shielding the extracellular space from excess K(+.

  13. Natural variability in the surface ocean carbonate ion concentration

    OpenAIRE

    N. S. Lovenduski; M. C. Long; K. Lindsay

    2015-01-01

    We investigate variability in the surface ocean carbonate ion concentration ([CO32−]) on the basis of a long control simulation with a fully-coupled Earth System Model. The simulation is run with a prescribed, pre-industrial atmospheric CO2 concentration for 1000 years, permitting investigation of natural [CO32−] variability on interannual to multi-decadal timescales. We find high interannual variability in surface [CO32−] in the tropical...

  14. Natural variability in the surface ocean carbonate ion concentration

    OpenAIRE

    Lovenduski, N. S.; Long, M. C.; Lindsay, K.

    2015-01-01

    We investigate variability in the surface ocean carbonate ion concentration ([CO32−]) on the basis of a~long control simulation with an Earth System Model. The simulation is run with a prescribed, pre-industrial atmospheric CO2 concentration for 1000 years, permitting investigation of natural [CO32−] variability on interannual to multi-decadal timescales. We find high interannual variability in surface [CO32−] in the tropical Pacific and ...

  15. The biological effectiveness of heavy ion radiations in the environment

    International Nuclear Information System (INIS)

    Craven, P.A.

    1996-03-01

    Although heavy ions are rarely encountered in the majority of terrestrial environments, the exposure of humans to this fascinating class of ionizing radiation is becoming more frequent. Long-duration spaceflight, new radiotherapeutic procedures and enhanced levels of radon, and other naturally-occurring alpha particle emitters, have all increased concern and stimulated interest recently within the radiological protection and radiobiological communities. Significant data concerning the long-term effects of low levels of heavy ions on mammalian systems are correspondingly scarce, leading to increased emphasis on modelling all aspects of the radiation-organism interaction. Contemporary radiation protection procedures reflect the need for a more fundamental understanding of the mechanisms responsible for the biological actions of such radiations. Major deficiencies exist in the current recommendations for assessment of relative effectiveness, the enhanced severity of the biological consequences instigated by heavy ions, over conventional sparsely ionizing radiations. In an attempt to remedy some of the inadequate concepts and assumptions presently employed and, simultaneously, to gain insight into the fundamental mechanisms behind the notion of radiation quality, a series of algorithms have been developed and executed as computer code, to evaluate the biological effectiveness of heavy ion radiation ''tracks'' according to a number of criteria. These include consideration of the spatial characteristics of physical energy deposition in idealised cellular structures (finite particle range, radial extension of tracks via δ-ray emission) and the likelihood of induction and mis-repair of severe molecular lesions (double-strand breaks, multiply-damaged sites). (author)

  16. Maximum concentrations at work and maximum biologically tolerable concentration for working materials 1991

    International Nuclear Information System (INIS)

    1991-01-01

    The meaning of the term 'maximum concentration at work' in regard of various pollutants is discussed. Specifically, a number of dusts and smokes are dealt with. The valuation criteria for maximum biologically tolerable concentrations for working materials are indicated. The working materials in question are corcinogeneous substances or substances liable to cause allergies or mutate the genome. (VT) [de

  17. Biological basis of heavy ion beams for cancer therapy

    International Nuclear Information System (INIS)

    Sakamoto, Kiyohiko

    1985-01-01

    Fast neutron therapy has started firstly and proton therapy has commenced secondly, fast neutron shows better biological effects compared to conventional radiations but its dose distribution is not good, and proton demonstrates excellent dose distribution but its biological effects are almost the same as that of conventional radiations. On the other hand, negative pi-mesons and heavy ions indicate high radiobiological effect and excellent dose distribution, therefore these particle radiations is considered to be more attractive for radiotherapeutic radiations to enhance cure rate of cancers. The biological strong points of these particles are as follows : 1) cells exposed to these particle radiations shows less recovery after irradiation compared to conventional radiations, 2) these radiations show high biological effects (high value of relative biological effectiveness = RBE) when the same dose is given, 3) big effects on hypoxic cells which exsist in tumor, i.e. the value of oxygen enhancement ratio (OER) is low, 4) the differences in radiosensitivity by stages of cell cycle are not so great (data was not shown in present paper), 5) biological effects at prepeak plateau region in depth dose curve formed by these particle radiations is less than that at peak region (therefore, if beam is modulated to cover tumor at spraed out broad peak, tumors is given more biological effect compared to normal tissues which is to be exposed to radiations at prepaeak region). Clinical trial using heavy ions are being performed at Lawrence Berkeley Laboratory which is only one facility to be able to try clinical trial. The results of clinical trials at Lawrence Berkeley Laboratory suggest to be very prospective to enhance tumor cure rate, however it is too early to estimate the effect of heavy ion therapy. (J.P.N.)

  18. Reactivity of the cadmium ion in concentrated phosphoric acid solutions.

    Science.gov (United States)

    De Gyves, J; Gonzales, J; Louis, C; Bessiere, J

    1989-07-01

    The solvation transfer coefficients which characterize the changes of ion reactivity with phosphoric acid concentration have been calculated for cadmium from the constants of the successive chloride complexes, and for silver and diethyldithiophosphate from potentiometric measurements. They evidence the strong desolvation of the cadmium species in concentrated phosphoric acid media, causing a remarkable increase of its reactivity. They allow the results of liquid-liquid extraction, precipitation and flotation reactions to be correctly interpreted and their changes to be foreseen when the reagents are modified.

  19. Ion beam induced fluorescence imaging in biological systems

    International Nuclear Information System (INIS)

    Bettiol, Andrew A.; Mi, Zhaohong; Vanga, Sudheer Kumar; Chen, Ce-belle; Tao, Ye; Watt, Frank

    2015-01-01

    Imaging fluorescence generated by MeV ions in biological systems such as cells and tissue sections requires a high resolution beam (<100 nm), a sensitive detection system and a fluorescent probe that has a high quantum efficiency and low bleaching rate. For cutting edge applications in bioimaging, the fluorescence imaging technique needs to break the optical diffraction limit allowing for sub-cellular structure to be visualized, leading to a better understanding of cellular function. In a nuclear microprobe this resolution requirement can be readily achieved utilizing low beam current techniques such as Scanning Transmission Ion Microscopy (STIM). In recent times, we have been able to extend this capability to fluorescence imaging through the development of a new high efficiency fluorescence detection system, and through the use of new novel fluorescent probes that are resistant to ion beam damage (bleaching). In this paper we demonstrate ion beam induced fluorescence imaging in several biological samples, highlighting the advantages and challenges associated with using this technique

  20. X-ray microanalytical surveys of minor element concentrations in unsectioned biological samples

    Science.gov (United States)

    Schofield, R. M. S.; Lefevre, H. W.; Overley, J. C.; Macdonald, J. D.

    1988-03-01

    Approximate concentration maps of small unsectioned biological samples are made using the pixel by pixel ratio of PIXE images to areal density images. Areal density images are derived from scanning transmission ion microscopy (STIM) proton energy-loss images. Corrections for X-ray production cross section variations, X-ray attenuation, and depth averaging are approximated or ignored. Estimates of the magnitude of the resulting error are made. Approximate calcium concentrations within the head of a fruit fly are reported. Concentrations in the retinula cell region of the eye average about 1 mg/g dry weight. Concentrations of zinc in the mandible of several ant species average about 40 mg/g. Zinc concentrations in the stomachs of these ants are at least 1 mg/g.

  1. Studies on influence of biological factors on concentration of radionuclides

    International Nuclear Information System (INIS)

    Anon.

    1974-01-01

    Biological factors influencing the concentration of radionuclides were studied from the points of uptake through digestive tract, food as pathways, and metabolic activities. The uptake of radionuclides by marine fishes through digestive tract was determined by whole body counter. 137 Cs, 65 Zn, 131 I, 54 Mn, 60 Co, 85 Sr, and 144 Ce were used as tracers and was given with solid feed. The feed given was excreated 24 to 48 hours later in small of middle sized fishes, and 20 to 48 hours later in large sized fishes. The uptake rate of 137 Cs and 65 Zn was high absorption of 20 to 80 per cent, that of 131 I, 60 Co and 54 Mn was not remarkable, and that of 85 Sr and 144 Ce was low absorption. The biological concentration of 137 Cs through pathways of food. In fishes taking up radionuclides through contaminated food, concentration factor increased in accordance with contamination level. In addition, radionuclides with small uptake but delayed excretion and those with high concentration rate could be the factors to decide the concentration factors of marine organisms. In order to study the relationship between metabolic activities and concentration, the uptake of one-year old fishes and adult fishes, and fishes fed and those non-fed were compared. One-year fishes took up large amount of 85 Sr during short period, however, concentration by metabolism in adult fishes was slow. Comparing feeding group and non-feeding group, the former showed 85 Sr concentration factor of 1.5 to 2 times that of the later, and the later showed 137 Cs concentration factor of 2 to 4 times that of the former. However, both uptake and excretion were rapid suggesting that taking food activated the metabolism of substances. (Kanao, N.)

  2. Atmospheric ions and probable indirect biological effect of low-level radiation

    International Nuclear Information System (INIS)

    Spurny, Z.

    1984-01-01

    The problem is discussed of the health consequences of low radiation doses (of less than 0.01 Gy). Owing to natural radioactivity and cosmic radiation, ions are formed in the atmosphere which may thus indirectly mediate the effects of ionizing radiation on the organism. The rate of ion formation is approximately 6.1 ion pairs/cm 3 .s and their number will not exceed 10 3 ions/cm 3 . In an environment where artificial radioactive sources are used, the ion concentration may reach up to 10 5 ions/cm 3 . The effect of ions on man may be divided into several types: 1. effect on mental state (behaviour, fatigue, headaches); 2. effect on the cardiovascular system; 3. effect on the bronchial system;and 4. effect on physiological processes, e.g., secretion by endocrine glands. It is not yet known whether the biological effect of small (fast) ions is a function of their electric charge only or of their kinetic energy as well. The view is discussed that low radiation doses through indirect effects have favourable and beneficial influence on the human organism. (M.D.)

  3. Enhanced Physicochemical and Biological Properties of Ion-Implanted Titanium Using Electron Cyclotron Resonance Ion Sources

    Directory of Open Access Journals (Sweden)

    Csaba Hegedűs

    2016-01-01

    Full Text Available The surface properties of metallic implants play an important role in their clinical success. Improving upon the inherent shortcomings of Ti implants, such as poor bioactivity, is imperative for achieving clinical use. In this study, we have developed a Ti implant modified with Ca or dual Ca + Si ions on the surface using an electron cyclotron resonance ion source (ECRIS. The physicochemical and biological properties of ion-implanted Ti surfaces were analyzed using various analytical techniques, such as surface analyses, potentiodynamic polarization and cell culture. Experimental results indicated that a rough morphology was observed on the Ti substrate surface modified by ECRIS plasma ions. The in vitro electrochemical measurement results also indicated that the Ca + Si ion-implanted surface had a more beneficial and desired behavior than the pristine Ti substrate. Compared to the pristine Ti substrate, all ion-implanted samples had a lower hemolysis ratio. MG63 cells cultured on the high Ca and dual Ca + Si ion-implanted surfaces revealed significantly greater cell viability in comparison to the pristine Ti substrate. In conclusion, surface modification by electron cyclotron resonance Ca and Si ion sources could be an effective method for Ti implants.

  4. EUD-based biological optimization for carbon ion therapy

    International Nuclear Information System (INIS)

    Brüningk, Sarah C.; Kamp, Florian; Wilkens, Jan J.

    2015-01-01

    Purpose: Treatment planning for carbon ion therapy requires an accurate modeling of the biological response of each tissue to estimate the clinical outcome of a treatment. The relative biological effectiveness (RBE) accounts for this biological response on a cellular level but does not refer to the actual impact on the organ as a whole. For photon therapy, the concept of equivalent uniform dose (EUD) represents a simple model to take the organ response into account, yet so far no formulation of EUD has been reported that is suitable to carbon ion therapy. The authors introduce the concept of an equivalent uniform effect (EUE) that is directly applicable to both ion and photon therapies and exemplarily implemented it as a basis for biological treatment plan optimization for carbon ion therapy. Methods: In addition to a classical EUD concept, which calculates a generalized mean over the RBE-weighted dose distribution, the authors propose the EUE to simplify the optimization process of carbon ion therapy plans. The EUE is defined as the biologically equivalent uniform effect that yields the same probability of injury as the inhomogeneous effect distribution in an organ. Its mathematical formulation is based on the generalized mean effect using an effect-volume parameter to account for different organ architectures and is thus independent of a reference radiation. For both EUD concepts, quadratic and logistic objective functions are implemented into a research treatment planning system. A flexible implementation allows choosing for each structure between biological effect constraints per voxel and EUD constraints per structure. Exemplary treatment plans are calculated for a head-and-neck patient for multiple combinations of objective functions and optimization parameters. Results: Treatment plans optimized using an EUE-based objective function were comparable to those optimized with an RBE-weighted EUD-based approach. In agreement with previous results from photon

  5. Compact high-sensitivity potentiometer for detection of low ion concentrations in liquids

    Science.gov (United States)

    Balevicius, Z.; Lescinskas, R.; Celiesiute, R.; Stirke, A.; Balevicius, S.; Kersulis, S.; Bleizgys, V.; Maciuleviciene, R.; Ramanavicius, A.; Zurauskiene, N.

    2018-04-01

    The compact potentiometer, based on an electronic circuit protected from electrostatic and electromagnetic interference, was developed for the measurement of low ion concentrations in liquids. The electronic circuit of the potentiometer, consisting of analogous and digital parts, enables the measurement of fA currents. This makes it possible to perform reliable measurements of ion concentrations in liquids that are as small as 10-8-10-7M. The instrument was tested using electrodes that were selective for tetraphenylphosphonium (TPP+) ions. It was demonstrated that the characteristic response time of the potentiometer electronic circuit to changes in the concentration of these ions in a liquid was in the order of 10 s. An investigation of TPP+ absorption by baker yeast has shown that this device can be successfully used for long term (several hours) measurements with zero signal drift, which was about 1 μV/s. Finally, due to the small dimensions of the electronic circuit (7.5 × 2 × 1.5 cm), this potentiometer can be easily installed at a large apparatus in the laboratory condition (≈25 °C), such as high pulsed electrical generators of magnetic fields that are used in electroporation studies of biological cells.

  6. Incineration of ion exchange resins using concentric burners

    International Nuclear Information System (INIS)

    Fukasawa, T.; Chino, K.; Kawamura, F.; Kuriyama, O.; Yusa, H.

    1985-01-01

    A new incineration method, using concentric burners, is studied to reduce the volume of spent ion exchange resins generated from nuclear power plants. Resins are ejected into the center of a propane-oxygen flame and burned within it. The flame length is theoretically evaluated by the diffusion-dominant model. By reforming the burner shape, flame length can be reduced by one-half. The decomposition ratio decreases with larger resin diameters due to the loss of unburned resin from the flame. A flame guide tube is adapted to increase resin holding time in the flame, which improves the decomposition ratio to over 98 wt%

  7. Anion analysis in uranium more concentrates by ion chromatography

    International Nuclear Information System (INIS)

    Badaut, V.

    2009-01-01

    In the present exploratory study, the applicability of anionic impurities or attributing nuclear material to a certain chemical process or origin has been investigated. Anions (e.g., nitrate, sulphate, fluoride, chloride) originate from acids or salt solutions that are used for processing of solutions containing uranium or plutonium. The study focuses on uranium ore concentrates ('yellow cakes') originating from different mines. Uranium is mined from different types of ore body and depending on the type of rock, different chemical processes for leaching, dissolving and precipitating the uranium need to be applied. Consequently, the anionic patterns observed in he products of these processes (the 'ore concentrates') are different. The concentrations of different anionic species were measured by ion chromatography using conductivity detection. The results show clear differences of anion concentrations and patterns between samples from different uranium mines. Besides this, differences between sampling campaigns n a same mine were also observed indicating that the uranium ore is not homogeneous in a mine. These within-mine variations, however, were smaller than the between-mine variations. (author)

  8. Determination of 18O concentrations in microsamples of biological fluids

    International Nuclear Information System (INIS)

    Cohen, D.D.; Bradshaw, S.D.; Bradshaw, F.J.

    1990-01-01

    The 18 O(p, α) 15 N reaction has been developed for the analysis of microsamples of biological fluids containing 18 O-enriched water. Samples as small as 50 μl have been used. Well characterized Ta 2 O 5 targets were prepared from these fluids and irradiated with several hundred nA of protons from the 3 MV Van de Graaff at Lucas Heights. The broad (47 keV) 846 kV resonance in this reaction was used to measure 18 O concentrations down to natural backgrounds (0.2 at.%) in a few minutes of accelerator running time. Concentrations of 18 O from 0 to 5 at.% were measured in body fluids in small Australian lizards directly after doping with 18 O-enriched water and then again after several days of roaming around in their natural desert environments. The changes in these levels were related to the metabolic rates of these animals. (orig.)

  9. Electrospray Ionization Mass Spectrometry: From Cluster Ions to Toxic metal Ions in Biology

    Energy Technology Data Exchange (ETDEWEB)

    Lentz, Nicholas B. [Iowa State Univ., Ames, IA (United States)

    2007-01-01

    This dissertation focused on using electrospray ionization mass spectrometry to study cluster ions and toxic metal ions in biology. In Chapter 2, it was shown that primary, secondary and quarternary amines exhibit different clustering characteristics under identical instrument conditions. Carbon chain length also played a role in cluster ion formation. In Chapters 3 and 4, the effects of solvent types/ratios and various instrumental parameters on cluster ion formation were examined. It was found that instrument interface design also plays a critical role in the cluster ion distribution seen in the mass spectrum. In Chapter 5, ESI-MS was used to investigate toxic metal binding to the [Gln11]-amyloid β-protein fragment (1-16). Pb and Cd bound stronger than Zn, even in the presence of excess Zn. Hg bound weaker than Zn. There are endless options for future work on cluster ions. Any molecule that is poorly ionized in positive ion mode can potentially show an increase in ionization efficiency if an appropriate anion is used to produce a net negative charge. It is possible that drug protein or drug/DNA complexes can also be stabilized by adding counter-ions. This would preserve the solution characteristics of the complex in the gas phase. Once in the gas phase, CID could determine the drug binding location on the biomolecule. There are many research projects regarding toxic metals in biology that have yet to be investigated or even discovered. This is an area of research with an almost endless future because of the changing dynamics of biological systems. What is deemed safe today may show toxic effects in the future. Evolutionary changes in protein structures may render them more susceptible to toxic metal binding. As the understanding of toxicity evolves, so does the demand for new toxic metal research. New instrumentation designs and software make it possible to perform research that could not be done in the past. What was undetectable yesterday will

  10. Ion Transport across Biological Membranes by Carborane-Capped Gold Nanoparticles.

    Science.gov (United States)

    Grzelczak, Marcin P; Danks, Stephen P; Klipp, Robert C; Belic, Domagoj; Zaulet, Adnana; Kunstmann-Olsen, Casper; Bradley, Dan F; Tsukuda, Tatsuya; Viñas, Clara; Teixidor, Francesc; Abramson, Jonathan J; Brust, Mathias

    2017-12-26

    Carborane-capped gold nanoparticles (Au/carborane NPs, 2-3 nm) can act as artificial ion transporters across biological membranes. The particles themselves are large hydrophobic anions that have the ability to disperse in aqueous media and to partition over both sides of a phospholipid bilayer membrane. Their presence therefore causes a membrane potential that is determined by the relative concentrations of particles on each side of the membrane according to the Nernst equation. The particles tend to adsorb to both sides of the membrane and can flip across if changes in membrane potential require their repartitioning. Such changes can be made either with a potentiostat in an electrochemical cell or by competition with another partitioning ion, for example, potassium in the presence of its specific transporter valinomycin. Carborane-capped gold nanoparticles have a ligand shell full of voids, which stem from the packing of near spherical ligands on a near spherical metal core. These voids are normally filled with sodium or potassium ions, and the charge is overcompensated by excess electrons in the metal core. The anionic particles are therefore able to take up and release a certain payload of cations and to adjust their net charge accordingly. It is demonstrated by potential-dependent fluorescence spectroscopy that polarized phospholipid membranes of vesicles can be depolarized by ion transport mediated by the particles. It is also shown that the particles act as alkali-ion-specific transporters across free-standing membranes under potentiostatic control. Magnesium ions are not transported.

  11. Scanning Ion Conductance Microscopy for Studying Biological Samples

    Directory of Open Access Journals (Sweden)

    Irmgard D. Dietzel

    2012-11-01

    Full Text Available Scanning ion conductance microscopy (SICM is a scanning probe technique that utilizes the increase in access resistance that occurs if an electrolyte filled glass micro-pipette is approached towards a poorly conducting surface. Since an increase in resistance can be monitored before the physical contact between scanning probe tip and sample, this technique is particularly useful to investigate the topography of delicate samples such as living cells. SICM has shown its potential in various applications such as high resolution and long-time imaging of living cells or the determination of local changes in cellular volume. Furthermore, SICM has been combined with various techniques such as fluorescence microscopy or patch clamping to reveal localized information about proteins or protein functions. This review details the various advantages and pitfalls of SICM and provides an overview of the recent developments and applications of SICM in biological imaging. Furthermore, we show that in principle, a combination of SICM and ion selective micro-electrodes enables one to monitor the local ion activity surrounding a living cell.

  12. Breath acetone concentration; biological variability and the influence of diet

    International Nuclear Information System (INIS)

    Španěl, Patrik; Dryahina, Kseniya; Rejšková, Alžběta; Chippendale, Thomas W E; Smith, David

    2011-01-01

    Previous measurements of acetone concentrations in the exhaled breath of healthy individuals and the small amount of comparable data for individuals suffering from diabetes are briefly reviewed as a prelude to the presentation of new data on the sporadic and wide variations of breath acetone that occur in ostensibly healthy individuals. Data are also presented which show that following a ketogenic diet taken by eight healthy individuals their breath acetone concentrations increased up to five times over the subsequent 6 h. Similarly, the breath acetone increased six and nine times when a low carbohydrate diet was taken by two volunteers and remained high for the several days for which the diet was continued. These new data, together with the previous data, clearly indicate that diet and natural intra-individual biological and diurnal variability result in wide variations in breath acetone concentration. This places an uncertainty in the use of breath acetone alone to monitor blood glucose and glycaemic control, except and unless the individual acts as their own control and is cognizant of the need for dietary control. (note)

  13. A concentration-independent micro/nanofluidic active diode using an asymmetric ion concentration polarization layer.

    Science.gov (United States)

    Lee, Hyekyung; Kim, Junsuk; Kim, Hyeonsoo; Kim, Ho-Young; Lee, Hyomin; Kim, Sung Jae

    2017-08-24

    Over the past decade, nanofluidic diodes that rectify ionic currents (i.e. greater current in one direction than in the opposite direction) have drawn significant attention in biomolecular sensing, switching and energy harvesting devices. To obtain current rectification, conventional nanofluidic diodes have utilized complex nanoscale asymmetry such as nanochannel geometry, surface charge density, and reservoir concentration. Avoiding the use of sophisticated nano-asymmetry, micro/nanofluidic diodes using microscale asymmetry have been recently introduced; however, their diodic performance is still impeded by (i) low (even absent) rectification effects at physiological concentrations over 100 mM and strong dependency on the bulk concentration, and (ii) the fact that they possess only passive predefined rectification factors. Here, we demonstrated a new class of micro/nanofluidic diode with an ideal perm-selective nanoporous membrane based on ion concentration polarization (ICP) phenomenon. Thin side-microchannels installed near a nanojunction served as mitigators of the amplified electrokinetic flows generated by ICP and induced convective salt transfer to the nanoporous membrane, leading to actively controlled micro-scale asymmetry. Using this device, current rectifications were successfully demonstrated in a wide range of electrolytic concentrations (10 -5 M to 3 M) as a function of the fluidic resistance of the side-microchannels. Noteworthily, it was confirmed that the rectification factors were independent from the bulk concentration due to the ideal perm-selectivity. Moreover, the rectification of the presenting diode was actively controlled by adjusting the external convective flows, while that of the previous diode was passively determined by invariant nanoscale asymmetry.

  14. [The relationship between PMI and concentration of potassium ion and sodium ion in swine aqueous humor after death].

    Science.gov (United States)

    Han, Ju; Yu, Guang-biao; Dong, Ye-qiang; Fang, Chao; Jing, Hua-lan; Luo, Si-min

    2010-04-01

    To explored the relationship between the concentration of potassium ion as well as sodium ion in the aqueous humor and post-mortem interval (PMI). The concentrations of potassium ion and sodium ion in the aqueous humor of swine within 48 h after death at 4 degrees C and 28 degrees C were detected using Z-500 atomic absorption spectrophotometer. The concentrations of potassium ion and sodium ion in aqueous humor of isolated swine eyeballs within 48 h after death when the environmental temperature was 4 degrees C were significantly related to PMI. The relationship between PMI and the concentration of potassium ion was PMI = -0.178[K+]2 + 49.978 (R2 = 0.995). The relationship between PMI and the rate of sodium ion and potassium ion was PMI = 120.987/[Na+/K+]-28.834 (R2 = 0.905). The concentration of potassium in aqueous humor of isolated swine eyeballs may be one of the reference indicators to estimate PMI of the corpses at lower temperatures.

  15. Biological processes for concentrating trace elements from uranium mine waters. Technical completion report

    International Nuclear Information System (INIS)

    Brierley, C.L.; Brierley, J.A.

    1981-12-01

    Waste water from uranium mines in the Ambrosia Lake district near Grants, New Mexico, USA, contains uranium, selenium, radium and molybdenum. The Kerr-McGee Corporation has a novel treatment process for waters from two mines to reduce the concentrations of the trace contaminants. Particulates are settled by ponding, and the waters are passed through an ion exchange resin to remove uranium; barium chloride is added to precipitate sulfate and radium from the mine waters. The mine waters are subsequently passed through three consecutive algae ponds prior to discharge. Water, sediment and biological samples were collected over a 4-year period and analyzed to assess the role of biological agents in removal of inorganic trace contaminants from the mine waters. Some of the conclusions derived from this study are: (1) The concentrations of soluble uranium, selenium and molybdenum were not diminished in the mine waters by passage through the series of impoundments which constituted the mine water treatment facility. Uranium concentrations were reduced but this was due to passage of the water through an ion exchange column. (2) The particulate concentrations of the mine water were reduced at least ten-fold by passage of the waters through the impoundments. (3) The sediments were anoxic and enriched in uranium, molybdenum and selenium. The deposition of particulates and the formation of insoluble compounds were proposed as mechanisms for sediment enrichment. (4) The predominant algae of the treatment ponds were the filamentous Spirogyra and Oscillatoria, and the benthic alga, Chara. (5) Adsorptive processes resulted in the accumulation of metals in the algae cells. (6) Stimulation of sulfate reduction by the bacteria resulted in retention of molybdenum, selenium, and uranium in sediments. 1 figure, 16 tables

  16. Ion transport through biological membranes an integrated theoretical approach

    CERN Document Server

    Mackey, Michael C

    1975-01-01

    This book illustrates some of the ways physics and mathematics have been, and are being, used to elucidate the underlying mechan­ isms of passive ion movement through biological membranes in general, and the membranes of excltable cells in particular. I have made no effort to be comprehensive in my introduction of biological material and the reader interested in a brief account of single cell electro­ physlology from a physically-oriented biologists viewpoint will find the chapters by Woodbury (1965) an excellent introduction. Part I is introductory in nature, exploring the basic electrical properties of inexcitable and excitable cell plasma membranes. Cable theory is utilized to illustrate the function of the non-decrementing action potential as a signaling mechanism for the long range trans­ mission of information in the nervous system, and to gain some in­ sight into the gross behaviour of neurons. The detailed analysis of Hodgkin and Huxley on the squid giant axon membrane ionic conductance properties...

  17. Natural variability in the surface ocean carbonate ion concentration

    Directory of Open Access Journals (Sweden)

    N. S. Lovenduski

    2015-11-01

    Full Text Available We investigate variability in the surface ocean carbonate ion concentration ([CO32−] on the basis of a~long control simulation with an Earth System Model. The simulation is run with a prescribed, pre-industrial atmospheric CO2 concentration for 1000 years, permitting investigation of natural [CO32−] variability on interannual to multi-decadal timescales. We find high interannual variability in surface [CO32−] in the tropical Pacific and at the boundaries between the subtropical and subpolar gyres in the Northern Hemisphere, and relatively low interannual variability in the centers of the subtropical gyres and in the Southern Ocean. Statistical analysis of modeled [CO32−] variance and autocorrelation suggests that significant anthropogenic trends in the saturation state of aragonite (Ωaragonite are already or nearly detectable at the sustained, open-ocean time series sites, whereas several decades of observations are required to detect anthropogenic trends in Ωaragonite in the tropical Pacific, North Pacific, and North Atlantic. The detection timescale for anthropogenic trends in pH is shorter than that for Ωaragonite, due to smaller noise-to-signal ratios and lower autocorrelation in pH. In the tropical Pacific, the leading mode of surface [CO32−] variability is primarily driven by variations in the vertical advection of dissolved inorganic carbon (DIC in association with El Niño–Southern Oscillation. In the North Pacific, surface [CO32−] variability is caused by circulation-driven variations in surface DIC and strongly correlated with the Pacific Decadal Oscillation, with peak spectral power at 20–30-year periods. North Atlantic [CO32−] variability is also driven by variations in surface DIC, and exhibits weak correlations with both the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. As the scientific community seeks to detect the anthropogenic influence on ocean carbonate chemistry, these results

  18. Natural variability in the surface ocean carbonate ion concentration

    Science.gov (United States)

    Lovenduski, N. S.; Long, M. C.; Lindsay, K.

    2015-11-01

    We investigate variability in the surface ocean carbonate ion concentration ([CO32-]) on the basis of a~long control simulation with an Earth System Model. The simulation is run with a prescribed, pre-industrial atmospheric CO2 concentration for 1000 years, permitting investigation of natural [CO32-] variability on interannual to multi-decadal timescales. We find high interannual variability in surface [CO32-] in the tropical Pacific and at the boundaries between the subtropical and subpolar gyres in the Northern Hemisphere, and relatively low interannual variability in the centers of the subtropical gyres and in the Southern Ocean. Statistical analysis of modeled [CO32-] variance and autocorrelation suggests that significant anthropogenic trends in the saturation state of aragonite (Ωaragonite) are already or nearly detectable at the sustained, open-ocean time series sites, whereas several decades of observations are required to detect anthropogenic trends in Ωaragonite in the tropical Pacific, North Pacific, and North Atlantic. The detection timescale for anthropogenic trends in pH is shorter than that for Ωaragonite, due to smaller noise-to-signal ratios and lower autocorrelation in pH. In the tropical Pacific, the leading mode of surface [CO32-] variability is primarily driven by variations in the vertical advection of dissolved inorganic carbon (DIC) in association with El Niño-Southern Oscillation. In the North Pacific, surface [CO32-] variability is caused by circulation-driven variations in surface DIC and strongly correlated with the Pacific Decadal Oscillation, with peak spectral power at 20-30-year periods. North Atlantic [CO32-] variability is also driven by variations in surface DIC, and exhibits weak correlations with both the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. As the scientific community seeks to detect the anthropogenic influence on ocean carbonate chemistry, these results will aid the interpretation of trends

  19. NO, nitrosonium ions, nitroxide ions, nitrosothiols and iron-nitrosyls in biology: a chemist's perspective.

    Science.gov (United States)

    Butler, A R; Flitney, F W; Williams, D L

    1995-01-01

    The multiplicity of biological functions thus far attributed to NO has led to suggestions that some effects might be mediated by other, related species instead. The radical nature of NO cannot account for its cytotoxicity, but its reaction with superoxide to form peroxynitite and highly reactive hydroxyl radicals may be important in this context. The ease with which NO can react with and destroy Fe-S clusters is also an important factor. Nitrosonium and nitroxide ions can be produced in vivo and will react under conditions that are physiologically relevant. Both could, in theory, serve in cell signalling or as cytotoxic agents. More direct experimental evidence for their involvement is needed before we can confidently assign them specific biological roles. In this article, Anthony Butler, Frederick Flitney and Lyn Williams discuss the chemistry of NO and related species.

  20. Ion-pair extraction of [3]histobadine from biological fluids

    International Nuclear Information System (INIS)

    Scasnar, V.

    1997-01-01

    A simple and specific radiometric assay was developed for determination of stobadine, a cardio protective drug, in the serum of experimental animals. It is based on a single extraction step of the radioactively labeled drug from serum into the benzene solution of dicarbolide of cobalt followed by the quantitation of the extracted radioactivity by using liquid scintillation counting. The extraction mechanism involves the ion-pair formation between the protonized molecule of stobadine and the hydrophobic, negatively charged molecule of dicarbollide of cobalt. The extraction of yield of stobadine from 1 ml of serum was 95% in the concentration range from 1 to 6000 ng/ml. The co extraction of metabolites was less than 5%. The assay was applied to determination of stobadine in serum of dogs and the data obtained were in good agreement with those obtained by high performance liquid chromatography. (author)

  1. A magnetic method to concentrate and trap biological targets

    KAUST Repository

    Li, Fuquan

    2012-11-01

    Magnetoresistive sensors in combination with magnetic particles have been used in biological applications due to, e.g., their small size and high sensitivity. A growing interest is to integrate magnetoresistive sensors with microchannels and electronics to fabricate devices that can perform complex analyses. A major task in such systems is to immobilize magnetic particles on top of the sensor surface, which is required to detect the particles\\' stray field. In the presented work, a bead concentrator, consisting of gold microstructures, at the bottom of a microchannel, is used to attract and move magnetic particles into a trap. The trap is made of a chamber with a gold microstructure underneath and is used to attract and immobilize a defined number of magnetic beads. In order to detect targets, two kinds of solutions were prepared; one containing only superparamagnetic particles, the other one containing beads with the protein Bovine serum albumin as the target and fluorescent markers. Due to the size difference between bare beads and beads with target, less magnetic beads were immobilized inside the volume chamber in case of magnetic beads with target as compared to bare magnetic beads. © 1965-2012 IEEE.

  2. A study on the ranges of low energy ions in biological samples and its mechanism of biological effects

    International Nuclear Information System (INIS)

    Lu Ting; Xie Liqing; Li Junping; Xia Ji

    1993-01-01

    The seeds of wheat and bean are irradiated by iron ion beam with energy 100 keV. The RBS spectra of the samples are observed and the ranges and distributions of the iron ions in the wheat and bean are calculated theoretically by means of Monte Carlo method. The results of theory and experiment are compared and the mechanism of biological effects induced by ion is discussed

  3. A Microfluidic Long-Period Fiber Grating Sensor Platform for Chloride Ion Concentration Measurement

    Directory of Open Access Journals (Sweden)

    Jian-Neng Wang

    2011-09-01

    Full Text Available Optical fiber sensors based on waveguide technology are promising and attractive in chemical, biotechnological, agronomy, and civil engineering applications. A microfluidic system equipped with a long-period fiber grating (LPFG capable of measuring chloride ion concentrations of several sample materials is presented. The LPFG-based microfluidic platform was shown to be effective in sensing very small quantities of samples and its transmitted light signal could easily be used as a measurand. The investigated sample materials included reverse osmosis (RO water, tap water, dilute aqueous sample of sea sand soaked in RO water, aqueous sample of sea sand soaked in RO water, dilute seawater, and seawater. By employing additionally a chloride ion-selective electrode sensor for the calibration of chloride-ion concentration, a useful correlation (R2 = 0.975 was found between the separately-measured chloride concentration and the light intensity transmitted through the LPFG at a wavelength of 1,550 nm. Experimental results show that the sensitivity of the LPFG sensor by light intensity interrogation was determined to be 5.0 × 10−6 mW/mg/L for chloride ion concentrations below 2,400 mg/L. The results obtained from the analysis of data variations in time-series measurements for all sample materials show that standard deviations of output power were relatively small and found in the range of 7.413 × 10−5–2.769 × 10−3 mW. In addition, a fairly small coefficients of variations were also obtained, which were in the range of 0.03%–1.29% and decreased with the decrease of chloride ion concentrations of sample materials. Moreover, the analysis of stability performance of the LPFG sensor indicated that the random walk coefficient decreased with the increase of the chloride ion concentration, illustrating that measurement stability using the microfluidic platform was capable of measuring transmitted optical power with accuracy in the range of −0

  4. COMPLEX OF NUMERICAL MODELS FOR COMPUTATION OF AIR ION CONCENTRATION IN PREMISES

    Directory of Open Access Journals (Sweden)

    M. M. Biliaiev

    2016-04-01

    Full Text Available Purpose. The article highlights the question about creation the complex numerical models in order to calculate the ions concentration fields in premises of various purpose and in work areas. Developed complex should take into account the main physical factors influencing the formation of the concentration field of ions, that is, aerodynamics of air jets in the room, presence of furniture, equipment, placement of ventilation holes, ventilation mode, location of ionization sources, transfer of ions under the electric field effect, other factors, determining the intensity and shape of the field of concentration of ions. In addition, complex of numerical models has to ensure conducting of the express calculation of the ions concentration in the premises, allowing quick sorting of possible variants and enabling «enlarged» evaluation of air ions concentration in the premises. Methodology. The complex numerical models to calculate air ion regime in the premises is developed. CFD numerical model is based on the use of aerodynamics, electrostatics and mass transfer equations, and takes into account the effect of air flows caused by the ventilation operation, diffusion, electric field effects, as well as the interaction of different polarities ions with each other and with the dust particles. The proposed balance model for computation of air ion regime indoors allows operative calculating the ions concentration field considering pulsed operation of the ionizer. Findings. The calculated data are received, on the basis of which one can estimate the ions concentration anywhere in the premises with artificial air ionization. An example of calculating the negative ions concentration on the basis of the CFD numerical model in the premises with reengineering transformations is given. On the basis of the developed balance model the air ions concentration in the room volume was calculated. Originality. Results of the air ion regime computation in premise, which

  5. Preferential solvation, ion pairing, and dynamics of concentrated aqueous solutions of divalent metal nitrate salts

    Science.gov (United States)

    Yadav, Sushma; Chandra, Amalendu

    2017-12-01

    We have investigated the characteristics of preferential solvation of ions, structure of solvation shells, ion pairing, and dynamics of aqueous solutions of divalent alkaline-earth metal nitrate salts at varying concentration by means of molecular dynamics simulations. Hydration shell structures and the extent of preferential solvation of the metal and nitrate ions in the solutions are investigated through calculations of radial distribution functions, tetrahedral ordering, and also spatial distribution functions. The Mg2+ ions are found to form solvent separated ion-pairs while the Ca2+ and Sr2+ ions form contact ion pairs with the nitrate ions. These findings are further corroborated by excess coordination numbers calculated through Kirkwood-Buff G factors for different ion-ion and ion-water pairs. The ion-pairing propensity is found to be in the order of Mg(NO3) 2 lead to the presence of substantial dynamical heterogeneity in these solutions of strongly interacting ions. The current study helps us to understand the molecular details of hydration structure, ion pairing, and dynamics of water in the solvation shells and also of ion diffusion in aqueous solutions of divalent metal nitrate salts.

  6. Ion concentration in micro and nanoscale electrospray emitters.

    Science.gov (United States)

    Yuill, Elizabeth M; Baker, Lane A

    2018-06-01

    Solution-phase ion transport during electrospray has been characterized for nanopipettes, or glass capillaries pulled to nanoscale tip dimensions, and micron-sized electrospray ionization emitters. Direct visualization of charged fluorophores during the electrospray process is used to evaluate impacts of emitter size, ionic strength, analyte size, and pressure-driven flow on heterogeneous ion transport during electrospray. Mass spectrometric measurements of positively- and negatively-charged proteins were taken for micron-sized and nanopipette emitters under low ionic strength conditions to further illustrate a discrepancy in solution-driven transport of charged analytes. A fundamental understanding of analyte electromigration during electrospray, which is not always considered, is expected to provide control over selective analyte depletion and enrichment, and can be harnessed for sample cleanup. Graphical abstract Fluorescence micrographs of ion migration in nanoscale pipettes while solution is electrosprayed.

  7. Direct Comparison of Biologically Optimized Spread-out Bragg Peaks for Protons and Carbon Ions

    International Nuclear Information System (INIS)

    Wilkens, Jan J.; Oelfke, Uwe

    2008-01-01

    Purpose: In radiotherapy with hadrons, it is anticipated that carbon ions are superior to protons, mainly because of their biological properties: the relative biological effectiveness (RBE) for carbon ions is supposedly higher in the target than in the surrounding normal tissue, leading to a therapeutic advantage over protons. The purpose of this report is to investigate this effect by using biological model calculations. Methods and Materials: We compared spread-out Bragg peaks for protons and carbon ions by using physical and biological optimization. The RBE for protons and carbon ions was calculated according to published biological models. These models predict increased RBE values in regions of high linear energy transfer (LET) and an inverse dependency of the RBE on dose. Results: For pure physical optimization, protons yield a better dose distribution along the central axis. In biologically optimized plans, RBE variations for protons were relatively small. For carbon ions, high RBE values were found in the high-LET target region, as well as in the low-dose region outside the target. This means that the LET dependency and dose dependency of the RBE can cancel each other. We show this for radioresistant tissues treated with two opposing beams, for which the predicted carbon RBE within the target volume was lower than outside. Conclusions: For tissue parameters used in this study, the model used does not predict a biologic advantage of carbon ions. More reliable model parameters and clinical trials are necessary to explore the true potential of radiotherapy with carbon ions

  8. A magnetic method to concentrate and trap biological targets

    KAUST Repository

    Li, Fuquan; Kosel, Jü rgen

    2012-01-01

    Magnetoresistive sensors in combination with magnetic particles have been used in biological applications due to, e.g., their small size and high sensitivity. A growing interest is to integrate magnetoresistive sensors with microchannels

  9. Poisson-Nernst-Planck-Fermi theory for modeling biological ion channels

    International Nuclear Information System (INIS)

    Liu, Jinn-Liang; Eisenberg, Bob

    2014-01-01

    A Poisson-Nernst-Planck-Fermi (PNPF) theory is developed for studying ionic transport through biological ion channels. Our goal is to deal with the finite size of particle using a Fermi like distribution without calculating the forces between the particles, because they are both expensive and tricky to compute. We include the steric effect of ions and water molecules with nonuniform sizes and interstitial voids, the correlation effect of crowded ions with different valences, and the screening effect of water molecules in an inhomogeneous aqueous electrolyte. Including the finite volume of water and the voids between particles is an important new part of the theory presented here. Fermi like distributions of all particle species are derived from the volume exclusion of classical particles. Volume exclusion and the resulting saturation phenomena are especially important to describe the binding and permeation mechanisms of ions in a narrow channel pore. The Gibbs free energy of the Fermi distribution reduces to that of a Boltzmann distribution when these effects are not considered. The classical Gibbs entropy is extended to a new entropy form — called Gibbs-Fermi entropy — that describes mixing configurations of all finite size particles and voids in a thermodynamic system where microstates do not have equal probabilities. The PNPF model describes the dynamic flow of ions, water molecules, as well as voids with electric fields and protein charges. The model also provides a quantitative mean-field description of the charge/space competition mechanism of particles within the highly charged and crowded channel pore. The PNPF results are in good accord with experimental currents recorded in a 10 8 -fold range of Ca 2+ concentrations. The results illustrate the anomalous mole fraction effect, a signature of L-type calcium channels. Moreover, numerical results concerning water density, dielectric permittivity, void volume, and steric energy provide useful details to

  10. Inactivation of the antibacterial and cytotoxic properties of silver ions by biologically relevant compounds.

    Directory of Open Access Journals (Sweden)

    Geraldine Mulley

    Full Text Available There has been a recent surge in the use of silver as an antimicrobial agent in a wide range of domestic and clinical products, intended to prevent or treat bacterial infections and reduce bacterial colonization of surfaces. It has been reported that the antibacterial and cytotoxic properties of silver are affected by the assay conditions, particularly the type of growth media used in vitro. The toxicity of Ag+ to bacterial cells is comparable to that of human cells. We demonstrate that biologically relevant compounds such as glutathione, cysteine and human blood components significantly reduce the toxicity of silver ions to clinically relevant pathogenic bacteria and primary human dermal fibroblasts (skin cells. Bacteria are able to grow normally in the presence of silver nitrate at >20-fold the minimum inhibitory concentration (MIC if Ag+ and thiols are added in a 1:1 ratio because the reaction of Ag+ with extracellular thiols prevents silver ions from interacting with cells. Extracellular thiols and human serum also significantly reduce the antimicrobial activity of silver wound dressings Aquacel-Ag (Convatec and Acticoat (Smith & Nephew to Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli in vitro. These results have important implications for the deployment of silver as an antimicrobial agent in environments exposed to biological tissue or secretions. Significant amounts of money and effort have been directed at the development of silver-coated medical devices (e.g. dressings, catheters, implants. We believe our findings are essential for the effective design and testing of antimicrobial silver coatings.

  11. Data to support "Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations & Biological Condition"

    Data.gov (United States)

    U.S. Environmental Protection Agency — Spreadsheets are included here to support the manuscript "Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations and Biological Condition". This...

  12. Detection of Chemical/Biological Agents and Stimulants using Quadrupole Ion Trap Mass Spectrometry

    International Nuclear Information System (INIS)

    Harmon, S.H.; Hart, K.J.; Vass, A.A.; Wise, M.B.; Wolf, D.A.

    1999-01-01

    Detection of Chemical/Biological Agents and Simulants A new detector for chemical and biological agents is being developed for the U. S. Army under the Chemical and Biological Mass Spectrometer Block II program. The CBMS Block II is designed to optimize detection of both chemical and biological agents through the use of direct sampling inlets[I], a multi- ported sampling valve and a turbo- based vacuum system to support chemical ionization. Unit mass resolution using air as the buffer gas[2] has been obtained using this design. Software to control the instrument and to analyze the data generated from the instrument has also been newly developed. Detection of chemical agents can be accomplished. using the CBMS Block II design via one of two inlets - a l/ I 6'' stainless steel sample line -Chemical Warfare Air (CW Air) or a ground probe with enclosed capillary currently in use by the US Army - CW Ground. The Block II design is capable of both electron ionization and chemical ionization. Ethanol is being used as the Cl reagent based on a study indicating best performance for the Biological Warfare (BW) detection task (31). Data showing good signal to noise for 500 pg of methyl salicylate injected into the CW Air inlet, 50 ng of dimethylmethylphosphonate exposed to the CW Ground probe and 5 ng of methyl stearate analyzed using the pyrolyzer inlet were presented. Biological agents are sampled using a ''bio-concentrator'' unit that is designed to concentrate particles in the low micron range. Particles are collected in the bottom of a quartz pyrolyzer tube. An automated injector is being developed to deliver approximately 2 pL of a methylating reagent, tetramethylamonium- hydroxide to 'the collected particles. Pyrolysis occurs by rapid heating to ca. 55OOC. Biological agents are then characterized by their fatty acid methyl ester profiles and by other biomarkers. A library of ETOH- Cl/ pyrolysis MS data of microorganisms used for a recently published study[3] has been

  13. Preparation of the Hexacyanoferrate Ion Exchanger Matrix to Concentrate 137Cs from Sea Water

    International Nuclear Information System (INIS)

    Murdahayu Makmur

    2007-01-01

    Preparation of the hexacyanoferrate ion exchanger matrix to concentrate 137 Cs from large volume sea water has been done. The Pre-concentration is needed because 137 Cs concentration in sea water is too low. The hexacyanoferrate ion exchanger matrix can be prepared by performing the reaction of 10 gram silica gel with potassium hexacyanoferrate on concentration variation of 0.0025 M - 0.04 M and copper chloride on concentration variation of 0.005 M - 0.08 M. The volume of each reagent was 25 ml. The performance of the ion exchanger matrix depends on the chemical compositions both of the mixtures, it was expected that no remaining Fe ion and free Cu from the initial reagent. The final effluent will analyzed for Fe and Cu using Atomic Absorption Spectrometer. The optimal molar composition ration for potassium hexacyanoferrate and copper chloride was 0.5 for 10 gram silica gel. (author)

  14. Variation and balance of positive air ion concentrations in a boreal forest

    Directory of Open Access Journals (Sweden)

    U. Hõrrak

    2008-02-01

    Full Text Available Air ions are characterized on the basis of measurements carried out in a boreal forest at the Hyytiälä SMEAR station, Finland, during the BIOFOR III campaign in spring 1999. The air ions were discriminated as small ions (charged molecular aggregates of the diameter of less than 2.5 nm, intermediate ions (charged aerosol particles of the diameter of 2.5–8 nm, and large ions (charged aerosol particles of the diameter of 8–20 nm. Statistical characteristics of the ion concentrations and the parameters of ion balance in the atmosphere are presented separately for the nucleation event days and non-event days. In the steady state, the ionization rate is balanced with the loss of small ions, which is expressed as the product of the small ion concentration and the ion sink rate. The widely known sinks of small ions are the recombination with small ions of opposite polarity and attachment to aerosol particles. The dependence of small ion concentration on the concentration of aerosol particles was investigated applying a model of the bipolar diffusion charging of particles by small ions. When the periods of relative humidity above 95% and wind speed less than 0.6 m s−1 were excluded, then the small ion concentration and the theoretically calculated small ion sink rate were closely negatively correlated (correlation coefficient −87%. However, an extra ion loss term of the same magnitude as the ion loss onto aerosol particles is needed for a quantitative explanation of the observations. This term is presumably due to the small ion deposition on coniferous forest. The hygroscopic growth correction of the measured aerosol particle size distributions was also found to be necessary for the proper estimation of the ion sink rate. In the case of nucleation burst events, the concentration of small positive ions followed the general balance equation, no extra ion loss in addition to the deposition on coniferous forest was detected, and the

  15. Concentration Distribution of Chloride Ion under the Influence of the Convection-Diffusion Coupling

    Directory of Open Access Journals (Sweden)

    Q. L. Zhao

    2017-01-01

    Full Text Available The transfer process of chloride ion under the action of the convection-diffusion coupling was analyzed in order to predict the corrosion of reinforcement and the durability of structure more accurately. Considering the time-varying properties of diffusion coefficient and the space-time effect of the convection velocity, the differential equation for chloride ion transfer under the action of the convection-diffusion coupling was constructed. And then the chloride ion transfer model was validated by the existing experimental datum and the actual project datum. The results showed that when only diffusion was considered, the chlorine ion concentration increased with the time and decreased with the decay index of time. Under the action of the convection-diffusion coupling, at each point of coupling region, the chloride ion concentration first increased and then decreased and tended to stabilize, and the maximum appeared at the moment of convection velocity being 0; in the diffusion zone, the chloride ion concentration increased over time, and the chloride ion concentration of the same location increased with the depth of convection (in the later period, the velocity of convection (in the early period, and the chloride ion concentration of the surface.

  16. Divalent Metal Ion Transport across Large Biological Ion Channels and Their Effect on Conductance and Selectivity

    Directory of Open Access Journals (Sweden)

    Elena García-Giménez

    2012-01-01

    Full Text Available Electrophysiological characterization of large protein channels, usually displaying multi-ionic transport and weak ion selectivity, is commonly performed at physiological conditions (moderate gradients of KCl solutions at decimolar concentrations buffered at neutral pH. We extend here the characterization of the OmpF porin, a wide channel of the outer membrane of E. coli, by studying the effect of salts of divalent cations on the transport properties of the channel. The regulation of divalent cations concentration is essential in cell metabolism and understanding their effects is of key importance, not only in the channels specifically designed to control their passage but also in other multiionic channels. In particular, in porin channels like OmpF, divalent cations modulate the efficiency of molecules having antimicrobial activity. Taking advantage of the fact that the OmpF channel atomic structure has been resolved both in water and in MgCl2 aqueous solutions, we analyze the single channel conductance and the channel selectivity inversion aiming to separate the role of the electrolyte itself, and the counterion accumulation induced by the protein channel charges and other factors (binding, steric effects, etc. that being of minor importance in salts of monovalent cations become crucial in the case of divalent cations.

  17. Use of a silver ion selective electrode to assess mechanisms responsible for biological effects of silver nanoparticles

    International Nuclear Information System (INIS)

    Koch, Marcus; Kiefer, Silke; Cavelius, Christian; Kraegeloh, Annette

    2012-01-01

    For a detailed analysis of the biological effects of silver nanoparticles, discrimination between effects related to the nano-scale size of the particles and effects of released silver ions is required. Silver ions are either present in the initial particle dispersion or released by the nanoparticles over time. The aim of this study is to monitor the free silver ion activity {Ag + } in the presence of silver nanoparticles using a silver ion selective electrode. Therefore, silver in the form of silver nanoparticles, 4.2 ± 1.4 nm and 2–30 nm in size, or silver nitrate was added to cell culture media in the absence or presence of A549 cells as a model for human type II alveolar epithelial cells. The free silver ion activity measured after the addition of silver nanoparticles was determined by the initial ionic silver content. The p {Ag + } values indicated that the cell culture media decrease the free silver ion activity due to binding of silver ions by constituents of the media. In the presence of A549 cells, the free silver ion activity was further reduced. The morphology of A549 cells, cultivated in DME medium containing 9.1% (v/v) FBS, was affected by adding AgNO 3 at concentrations of ≥30 μM after 24 h. In comparison, silver nanoparticles up to a concentration of 200 μM Ag did not affect cellular morphology. Our experiments indicate that the effect of silver nanoparticles is mainly mediated by silver ions. An effect of silver on cellular morphology was observed at p {Ag + } ≤ 9.2.

  18. Removing ferric ions from concentrated acid leaching solution of an uranium ore by jarosite

    International Nuclear Information System (INIS)

    Song Huanbi; Hu Yezang

    1997-01-01

    The author expounds the fundamental rules of removing ferric ions by jarosite and presents results of removing ferric ions from concentrated acid curing-trickle leaching solution of an uranium ore. It turns out that the method can be applied to uranium hydrometallurgical process effectively

  19. Energy loss and straggling of MeV ions through biological samples

    International Nuclear Information System (INIS)

    Ma Lei; Wang Yugang; Xue Jianming; Chen Qizhong; Zhang Weiming; Zhang Yanwen

    2007-01-01

    Energy loss and energy straggling of energetic ions through natural dehydrated biological samples were investigated using transmission technique. Biological samples (onion membrane, egg coat, and tomato coat) with different mass thickness were studied, together with Mylar for comparison. The energy loss and energy straggling of MeV H and He ions after penetrating the biological and Mylar samples were measured. The experimental results show that the average energy losses of MeV ions through the biological samples are consistent with SRIM predictions; however, large deviation in energy straggling is observed between the measured results and the SRIM predictions. Taking into account inhomogeneity in mass density and structure of the biological sample, an energy straggling formula is suggested, and the experimental energy straggling values are well predicted by the proposed formula

  20. Ion exchange separation of low boric acid concentrations from water

    International Nuclear Information System (INIS)

    Kysela, J.; Brabec, J.; Peterka, F.

    1975-01-01

    Boric acid poisoning of the moderator of the TR-O experimental heavy water reactor was studied. The possibility is discussed of removing boric acid from heavy water by means of a strong basic anion exchanger, below the residual concentration of 0.01 mg B/l. Measurements of the usable capacities of the strong basic anion exchanger Zerollit FF showed that the penetration of boric acid during the sorption period does not exceed the value of 0.015 mg B/l. The dependence was found of capacity on the boric acid concentration in the solution. Analytical methods used to determine B in water are also described. (author)

  1. Integrated Microanalytical System for Simultaneous Voltammetric Measurements of Free Metal Ion Concentrations in Natural Waters

    OpenAIRE

    Noël, Stéphane; Tercier-Waeber, Mary-Lou; Lin, Lin; Buffle, Jacques; Guenat, Olivier; Koudelka-Hep, Milena

    2007-01-01

    A complexing gel integrated microelectrode (CGIME) for direct measurements of free metal ion concentrations in natural waters has been developed. It is prepared by the successive deposition of microlayers of a chelating resin, an antifouling agarose gel and Hg on a 100-interconnected Ir-based microelectrode array. The trace metals of interest are in a first step accumulated on the chelating resin in proportion to their free ion concentration in solution, then released in acidic solution and d...

  2. Influence of Temperature and Ion Concentration on Sedimentation ...

    African Journals Online (AJOL)

    ADOWIE PERE

    2017-12-16

    Dec 16, 2017 ... Rate data of sedimentation is useful in the design of sedimentation tanks and in modeling two-phase flow operations (Obunwo and Iboroma,. 2015). Mathematical models such as those by Stokes and. Vesilind respectively describe sedimentation of particles in dilute and concentrated suspension media.

  3. Recent advances in biological effect and molecular mechanism of arabidopsis thaliana irradiated by ion beams

    International Nuclear Information System (INIS)

    Wu Dali; Hou Suiwen; Li Wenjian

    2008-01-01

    Newly research progresses were summarized in effect of ion beams on seed surface, biological effect, growth, development, gravitropism and so on. Furthermore, mutation molecular mechanism of Arabidopsis thaliana was discussed, for example, alteration of DNA bases, DNA damage, chromosomal recombination, characteristics of mutant transmissibility, etc. Meanwhile, the achievements of transfer- ring extraneous gene to Arabidopsis thaliana by ion beams were reviewed in the paper. At last, the future prospective are also discussed here in mutation molecular mechanism and the potential application of biological effect of heavy ion beams. (authors)

  4. Biological intercomparison using gut crypt survivals for proton and carbon ions

    International Nuclear Information System (INIS)

    Uzawa, Akiko; Ando, Koichi; Furusawa, Yoshiya

    2006-01-01

    Charged particle therapy depends on biological information for the dose prescription. Relative biological effectiveness or relative biological effectiveness (RBE) for this requirement could basically be provided by experimental data. As RBE values of protons and carbon ions depend on several factors such as cell/tissue type, endpoint, dose and fractionation schedule, a single RBE value could not function as a master key to open all rooms filled with guests of different radiosensitivities. However, any biological model with accurate reproducibility is useful for comparing biological effectiveness between different facilities. We used mouse gut crypt survivals as endpoint, and compared the cell killing efficiency of proton beams at three Japanese facilities. Three Linac X-ray machines with 4 and 6 MeV were used as reference beams, and there was only a small variation (coefficient of variance <2%) in biological effectiveness among them. The RBE values of protons relative to Linac X-rays ranged from 1.0 to 1.11 at the middle of a 6-cm SOBP (spread-out Bragg peak) and from 0.96 to 1.01 at the entrance plateau. The coefficient of variance for protons ranged between 4.0 and 5.1%. The biological comparison of carbon ions showed fairly good agreement in that the difference in biological effectiveness between National Institute of Radiological Sciences (NIRS)/Heavy Ion Medical Accelerator in Chiba (HIMAC) and Gesellschaft fur Schwerionenforschung (GSI)/Heavy Ion Synchrotron (SIS) was 1% for three positions within the 6-cm SOBP. The coefficient of variance was <1.7, <0.6 and <1.6% for proximal, middle and distal SOBP, respectively. We conclude that the inter-institutional variation of biological effectiveness is smaller for carbon ions than protons, and that beam-spreading methods of carbon ions do not critically influence gut crypt survival. (author)

  5. Biological intercomparison using gut crypt survivals for proton and carbon-ion beams

    International Nuclear Information System (INIS)

    Uzawa, Akiko; Ando, Koichi; Furusawa, Yoshiya

    2007-01-01

    Charged particle therapy depends on biological information for the dose prescription. Relative biological effectiveness or RBE for this requirement could basically be provided by experimental data. As RBE values of protons and carbon ions depend on several factors such as cell/tissue type, biological endpoint, dose and fractionation schedule, a single RBE value could not deal with all different radiosensitivities. However, any biological model with accurate reproducibility is useful for comparing biological effectiveness between different facilities. We used mouse gut crypt survivals as endpoint, and compared the cell killing efficiency of proton beams at three Japanese facilities. Three Linac X-ray machines with 4 and 6 MeV were used as reference beams, and there was only a small variation (coefficient of variance<2%) in biological effectiveness among them. The RBE values of protons relative to Linac X-rays ranged from 1.0 to 1.11 at the middle of a 6-cm SOBP (spread-out Bragg peak) and from 0.96 to 1.01 at the entrance plateau. The coefficient of variance for protons ranged between 4.0 and 5.1%. The biological comparison of carbon ions showed fairly good agreement in that the difference in biological effectiveness between National Institute of Radiological Sciences (NIRS)/ Heavy Ion Medical Accelerator in Chiba (HIMAC) and Gesellschaft fur Schwerionenforschung (GSI)/Heavy Ion Synchrotron (SIS) was 1% for three positions within the 6-cm SOBP. The coefficient of variance was <1.7, <0.6 and <1.6% for proximal, middle and distal SOBP, respectively. We conclude that the inter-institutional variation of biological effectiveness is smaller for carbon ions than protons, and that beam-spreading methods of carbon ions do not critically influence gut crypt survival. (author)

  6. Concentrated ion beam emitted from an enlarged cylindrical-anode-layer Hall plasma accelerator and mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Geng, S. F.; Wang, C. X. [Southwestern Institute of Physics, Chengdu 610041 (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Tang, D. L.; Qiu, X. M. [Southwestern Institute of Physics, Chengdu 610041 (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

    2013-01-28

    An enlarged cylindrical-anode-layer Hall plasma accelerator with an outlet diameter of 150 mm is experimentally demonstrated to produce a concentrated ion beam, especially at a high discharge voltage, with a high current utilization efficiency of up to {approx}0.9. Numerical investigation based on the three-dimensional particle-in-cell method is performed to study the ion dynamics and elucidate the origin of the ion beam characteristics. The simulation results reveal that the equipotential lines play an important role in the surface near the anode emitting the ions. The ion emitting surface is determined by the magnetic field lines near the anode and the magnetic mirror contributes to the concentrated beam significantly. The high current utilization efficiency results from the appropriate obliquity of the magnetic mirror.

  7. A concentrated electrolyte for zinc hexacyanoferrate electrodes in aqueous rechargeable zinc-ion batteries

    Science.gov (United States)

    Kim, D.; Lee, C.; Jeong, S.

    2018-01-01

    In this study, a concentrated electrolyte was applied in an aqueous rechargeable zinc-ion battery system with a zinc hexacyanoferrate (ZnHCF) electrode to improve the electrochemical performance by changing the hydration number of the zinc ions. To optimize the active material, ZnHCF was synthesized using aqueous solutions of zinc nitrate with three different concentrations. The synthesized materials exhibited some differences in structure, crystallinity, and particle size, as observed by X-ray diffraction and scanning electron microscopy. Subsequently, these well-structured materials were applied in electrochemical tests. A more than two-fold improvement in the charge/discharge capacities was observed when the concentrated electrolyte was used instead of the dilute electrolyte. Additionally, the cycling performance observed in the concentrated electrolyte was superior to that in the dilute electrolyte. This improvement in the electrochemical performance may result from a decrease in the hydration number of the zinc ions in the concentrated electrolyte.

  8. Effect of Ferric Ions on Bioleaching of Pentlandite Concentrate

    Science.gov (United States)

    Li, Qian; Lai, Huimin; Yang, Yongbin; Xu, Bin; Jiang, Tao; Zhang, Yaping

    The intensified effects of ferric phosphate and ferric sulfate as nutrient and oxidant on the bioleaching of pentlandite concentrate with Acidithiobacillus ferrooxidans and Sulfobacillus thermosulfidooxidans were studied. The results showed that the nickel leaching rate was enhanced continuously with FePO4 or Fe2(SO4)3 added in certain extent, but declined at excess. For A. ferrooxidans, the optimum additive amount of Fe2(SO4)3 was 6.63mM/L and the nickel leaching rate reached 71.76%. Compared with Fe2(SO4)3, the optimum additive amount of FePO4 was 26.52mM/L for both strains. For A. ferrooxidans and S. thermosulfidooxidans, the nickel leaching rate could increase to 98.06% and 98.11% which was 1.83 times and 1.55 times of the leachig rate of blank test, respectively.

  9. Influence of zirconium ion concentration in model extraction systems TBP - diluents - Zr+4 - nitric acid

    International Nuclear Information System (INIS)

    Rogoz, F.; Tlalka, M.

    1987-07-01

    In systems containing TBP, MBP, DBP and 1-butanol stable emulsions and precipitates are formed which separation is difficult in certain domain of concentration in zirconium ions. MPB and DBP increase stability of primary emulsion in kerosen and carbon tetrachloride but for different concentrations of nitric acid. Addition of 1-butanol decreases slightly the stability of primary emulsion [fr

  10. Binding of ferric ions is essential for the biological activity of glycine-extended gastrin

    International Nuclear Information System (INIS)

    Baldwin, G.S.; Pannequin, J.; Hollande, F.; Shulkes, A.

    2002-01-01

    Full text: Non-amidated gastrins, such as glycine-extended gastrin17 (Ggly), are now known to be biologically active. Ggly stimulates cell proliferation and migration, and was recently shown to bind two ferric ions with high affinity. The objective of the present work was to define the structure of Ggly for the first time, and to investigate the role of ferric ions in biological activity. Methods: The structure of Ggly, and the identity of the ammo acids that act as ferric ion ligands, were determined by NMR and fluorescence spectroscopy. The effect on the gastric epithelial cell line IMGE-5 of Ggly fragments, and of Ggy mutants with some or all of the five consecutive glutamate residues replaced by alanine, was measured in terms of cell proliferation, cell migration and phosphorylation of focal adhesion kinase. Results: Ggly adopts a well-defined loop stabilised by hydrophobic interactions between Leu5, Tyrl2, Trp 14 and Phe17. Studies with Ggly fragments indicated that ferric ions bind via the pentaglutamate sequence, which is necessary but not sufficient for full activity Selective replacement of some or all of the glutamates results in a reduction in ferric ion binding, and complete loss of biological activity. Conclusion: Our results are consistent with the hypothesis that ferric ion binding is necessary for biological activity

  11. Biological effectiveness and application of heavy ions in radiation therapy described by a physical and biological model

    International Nuclear Information System (INIS)

    Olsen, K.J.; Hansen, J.W.

    1982-12-01

    A description is given of the physical basis for applying track structure theory in the determination of the effectiveness of heavy-ion irradiation of single- and multi-hit target systems. It will be shown that for applying the theory to biological systems the effectiveness of heavy-ion irradiation is inadequately described by an RBE-factor, whereas the complete formulation of the probability of survival must be used, as survival depends on both radiation quality and dose. The theoretical model of track structure can be used in dose-effect calculations for neutron-, high-LET, and low-LET radiation applied simultaneously in therapy. (author)

  12. Purification and concentration of lead samples in biological monitoring of occupational exposures

    Directory of Open Access Journals (Sweden)

    A Rahimi-Froushani

    2006-04-01

    Full Text Available Background and Aims:Lead is an important environmental constituent widely used in industrialprocesses for production of synthetic materials and therefore can be released in the environmentcausing public exposure especially around the industrial residence area. For evaluation of humanexposure to trace toxic metal of Pb (II, environmental and biological monitoring are essentialprocesses, in which, preparation of such samples is one of the most time-consuming and errorproneaspects prior to analysis. The use of solid-phase extraction (SPE has grown and is a fertiletechnique of sample preparation as it provides better results than those produced by liquid-liquidextraction (LLE. The aim of this study was to investigate factors influencing sample pretreatmentfor trace analysis of lead in biological samples for evaluation of occupational exposure.Method :To evaluate factors influencing quantitative analysis scheme of lead, solid phaseextraction using mini columns filled with XAD-4 resin was optimized with regard to sample pH,ligand concentration, loading flow rate, elution solvent, sample volume (up to 500 ml, elutionvolume, amount of resins, and sample matrix interferences.Results :Lead was retained on solid sorbent and eluted followed by simple determination ofanalytes by using flame atomic absorption spectrometery. Obtained recoveries of the metal ionwere more than 92%. The amount of the analyte detected after simultaneous pre-concentrationwas basically in agreement with the added amounts. The optimized procedure was also validatedwith three different pools of spiked urine samples and showed a good reproducibility over sixconsecutive days as well as six within-day experiments. The developed method promised to beapplicable for evaluation of other metal ions present in different environmental and occupationalsamples as suitable results were obtained for relative standard deviation (less than 10%.Conclusion:This optimized method can be considered to be

  13. Bragg peak and relative biological efficiency of different ions

    Czech Academy of Sciences Publication Activity Database

    Lokajíček st., Miloš; Judas, Libor; Kundrát, Pavel

    2002-01-01

    Roč. 64, Suppl. 1 (2002), S309-S309 ISSN 0167-8140 R&D Projects: GA AV ČR(CZ) KSK4055109 Keywords : Bragg peak * relative biological efficisncy * radiological mechanism Subject RIV: CC - Organic Chemistry Impact factor: 2.838, year: 2002

  14. Effects of Organic Corrosion Inhibitor and Chloride Ion Concentration on Steel Depassivation and Repassivation in Solution

    Institute of Scientific and Technical Information of China (English)

    WANG Zixiao; YU Lei; LIU Zhiyong; SONG Ning

    2015-01-01

    Effect of an organic corrosion inhibitor (OCI) named PCI-2014 added in chloride solution on the critical chlo-ride concentration of mild steel depassivation and the critical OCI concentrations for repairing the steel in different chlo-ride solution were investigated. The results show that the critical chloride concentration increases exponentially with raises of PCI-2014 concentration in the solution. Within a certain chloride ion concentration range, the critical PCI-2014 concentration for repairing the corroded steel is also increases exponentially with enhancement of chloride content in the solution. Atomic force microscopy images display the molecular particles of inhibitor are adsorbed on the steel surface and formed a protective layer. Analysis of X-ray photoelectron spectroscopy shows the chloride ions at the surface of steel are displaced by atoms or molecules of the inhibitor in chloride condition.

  15. Reduced blood flow increases the in vivo ammonium ion concentration in the RIF-1 tumor

    International Nuclear Information System (INIS)

    Constantinidis, Ioannis; Gamcsik, Michael P.

    1995-01-01

    Purpose: Previous studies from our laboratory have suggested that pooling of ammonium in tumor tissues may be caused by its inefficient removal due to the poor vasculature commonly found in tumors. The purpose of these experiments was to validate the relationship between tumor ammonium ion concentration and tumor blood flow, and to determine whether large concentrations of ammonium ion detected by Nuclear Magnetic Resonance (NMR) spectroscopy are either produced within the tumor or simply imported into the tumor through the blood stream. Methods and Materials: To test this hypothesis, we reduced blood flow in subcutaneously grown Radiation Induced Fibrosarcoma-1 (RIF-1) tumors, either by creating partial ischemia with a bolus injection of hydralazine or by occlusion with surgical sutures. 14 N and 31 P NMR spectroscopy were used to detect the presence of ammonium, and to assess the bioenergetic status of the tumors, respectively. Results: A correlation between ammonium ion concentration and (PCr(P i )) ratio was established for untreated tumors. An increase in the in vivo tumor ammonium ion concentration was observed for every tumor that experienced a reduction in blood flow caused by either hydralazine injection or suture ligation. Changes in ammonium ion concentration paralleled changes in the bioenergetics of hydralazine-treated tumors. Conclusion: Our results support the hypothesis that a reduction in tumor blood flow is responsible for the accumulation of ammonium in tumors, and that detected ammonium originated from within the tumor

  16. Biological removal of metal ions from aqueous process streams

    International Nuclear Information System (INIS)

    Shumate, S.E. II; Strandberg, G.W.; Parrott, J.R. Jr.

    1978-01-01

    Aqueous waste streams from nuclear fuel processing operations may contain trace quantities of heavy metals such as uranium. Conventional chemical and physical treatment may be ineffective or very expensive when uranium concentrations in the range of 10 to 100 g/m 3 must be reduced to 1 g/m 3 or less. The ability of some microorganisms to adsorb or complex dissolved heavy metals offers an alternative treatment method. Uranium uptake by Saccharomyces cerevisiae NRRL Y-2574 and a strain of Pseudomonas aeruginosa was examined to identify factors which might affect a process for the removal of uranium from wastewater streams. At uranium concentrations in the range of 10 to 500 g/m 3 , where the binding capacity of the biomass was not exceeded, temperature, pH, and initial uranium concentration were found to influence the rate of uranium uptake, but not the soluble uranium concentration at equilibrium. 6 figs

  17. A procedure for reducing the concentration of hydrogen ions in acid anionic eluate and equipment therefore

    International Nuclear Information System (INIS)

    Parobek, P.; Baloun, S.; Plevac, S.

    1989-01-01

    The method is described of reducing the concentration of hydrogen ions in acid anionic eluate produced in the separation of uranium or other metals, in which anion exchanger elution, precipitation, filtration and precipitate and anion exchanger washing are used. The technological line for such elution comprises at least one ion exchange column and at least one container. They together form the first and the second stages of preparation of the acid anion elution solution, the sorption-elution separation of hydrogen ions on an cation exchanger being inserted between them. The preparation of the solution is divide into two stages. In the first stage, the acid and part of the solution for the preparation of the acid anion elution solution are supplied. The resulting enriched acid elution solution is fe onto the cation exchanger where the hydrogen ion concentration i reduced. It is then carried into the second stage where it is mixed with the remaining part of the solution. (B.S.)

  18. Effects of macro nutrient concentration on biological N2 fixation by Azotobacter vinelandii ATCC 12837

    International Nuclear Information System (INIS)

    Liew Pauline Woan Ying; Nazalan Najimudin; Jong Bor Chyan; Latiffah Noordin; Khairuddin Abdul Rahim; Amir Hamzah Ahmad Ghazali

    2010-01-01

    The dynamic changes of biological N 2 fixation by Azotobacter vinelandii ATCC 12837 under the influence of various macro nutrients, specifically phosphorus (P) and potassium (K), was investigated. In this attempt, Oryza sativa L. var. MR 219 was used as the model plant. Results obtained showed changes in the biological N 2 fixation activities with different macro nutrient(s) manipulations. The research activity enables optimisation of macro nutrients concentration for optimal/ enhanced biological N 2 fixation by A. vinelandii ATCC 12837. (author)

  19. The present state and perspectives of low-energy heavy ion biology

    International Nuclear Information System (INIS)

    Yuan Chengling; Yu Zengliang

    2004-01-01

    The interaction between low-energy ions and matter has been concerned rarely comparing to that of high-energy ions. It is even more unusual to find studies of the interaction of low-energy ions and complicated organisms. However, the discovery of bioeffects induced by ion beam implantation has opened a new branch in the field of ion beam applications in the life science--Low-energy Heavy Ion Biology. The mutagenic effect of low energy heavy ions was firstly reported in 1986 in rice. Since then, a damage mechanism involved in energy absorption, mass deposition, and charge exchange has been proposed. Accumulating evidence has indicated that these three factors are key determinants in the bioeffects induced by low energy heavy ions, which has opened new opportunities for mutational breeding, gene transferring, cell modification, and cell fusion. In recent years, the ion beam implantation technique has been widely applied in many fields, and increasing research interest in the field has been seen. The authors summarize recent advances in research on the role of low-energy ions in terms of the mechanisms and applications

  20. Effect of ion concentrations on uranium absorption from sodium carbonate solutions

    International Nuclear Information System (INIS)

    Traut, D.E.; El Hazek, N.M.T.; Palmer, G.R.; Nichols, I.L.

    1979-01-01

    The effect of various ion concentrations on uranium absorption from a sodium carbonate solution by a strong-base, anion resin was investigated in order to help assure an adequate uranium supply for future needs. The studies were conducted to improve the recovery of uranium from in situ leach solutions by ion exchange. The effects of carbonate, bicarbonate, chloride, and sulfate ions were examined. Relatively low (less than 5 g/l) concentrations of chloride, sulfate, and bicarbonate were found to be detrimental to the absorption of uranium. High (greater than 10 g/l) carbonate concentrations also adversely affected the uranium absorption. In addition, the effect of initial resin form was investigated in tests of the chloride, carbonate, and bicarbonate forms; resin form was shown to have no effect on the absorption of uranium

  1. Chaotic Dynamics Mediates Brain State Transitions, Driven by Changes in Extracellular Ion Concentrations

    DEFF Research Database (Denmark)

    Rasmussen, Rune; H. Jensen, Mogens; L. Heltberg, Mathias

    2017-01-01

    Previous studies have suggested that changes in extracellular ion concentrations initiate the transition from an activity state that characterizes sleep in cortical neurons to states that characterize wakeful- ness. However, because neuronal activity and extra- cellular ion concentrations...... are interdependent, isolating their unique roles during sleep-wake transitions is not possible in vivo. Here, we extend the Averaged-Neuron model and demonstrate that, although changes in extracellular ion concentrations occur concurrently, decreasing the conductance of calcium-dependent potassium channels initiates...... the transition from sleep to wakefulness. We find that sleep is governed by stable, self-sustained oscillations in neuronal firing patterns, whereas the quiet awake state and active awake state are both governed by irregular oscillations and chaotic dynamics; transitions between these separable awake states...

  2. Monitoring changes in membrane polarity, membrane integrity, and intracellular ion concentrations in Streptococcus pneumoniae using fluorescent dyes.

    Science.gov (United States)

    Clementi, Emily A; Marks, Laura R; Roche-Håkansson, Hazeline; Håkansson, Anders P

    2014-02-17

    Membrane depolarization and ion fluxes are events that have been studied extensively in biological systems due to their ability to profoundly impact cellular functions, including energetics and signal transductions. While both fluorescent and electrophysiological methods, including electrode usage and patch-clamping, have been well developed for measuring these events in eukaryotic cells, methodology for measuring similar events in microorganisms have proven more challenging to develop given their small size in combination with the more complex outer surface of bacteria shielding the membrane. During our studies of death-initiation in Streptococcus pneumoniae (pneumococcus), we wanted to elucidate the role of membrane events, including changes in polarity, integrity, and intracellular ion concentrations. Searching the literature, we found that very few studies exist. Other investigators had monitored radioisotope uptake or equilibrium to measure ion fluxes and membrane potential and a limited number of studies, mostly in Gram-negative organisms, had seen some success using carbocyanine or oxonol fluorescent dyes to measure membrane potential, or loading bacteria with cell-permeant acetoxymethyl (AM) ester versions of ion-sensitive fluorescent indicator dyes. We therefore established and optimized protocols for measuring membrane potential, rupture, and ion-transport in the Gram-positive organism S. pneumoniae. We developed protocols using the bis-oxonol dye DiBAC4(3) and the cell-impermeant dye propidium iodide to measure membrane depolarization and rupture, respectively, as well as methods to optimally load the pneumococci with the AM esters of the ratiometric dyes Fura-2, PBFI, and BCECF to detect changes in intracellular concentrations of Ca(2+), K(+), and H(+), respectively, using a fluorescence-detection plate reader. These protocols are the first of their kind for the pneumococcus and the majority of these dyes have not been used in any other bacterial

  3. The effect of hydrogen peroxide concentration on metal ion release from dental casting alloys.

    Science.gov (United States)

    Al-Salehi, S K; Hatton, P V; Johnson, A; Cox, A G; McLeod, C

    2008-04-01

    There are concerns that tooth bleaching agents may adversely affect dental materials. The aim of this study was to test the hypothesis that increasing concentrations of hydrogen peroxide (HP) are more effective than water at increasing metal ion release from two typical dental casting alloys during bleaching. Discs (n = 28 for each alloy) were prepared by casting and heat treated to simulate a typical porcelain-firing cycle. Discs (n = 7) of each alloy were immersed in either 0%, 3%, 10% or 30% (w/v) HP solutions for 24 h at 37 degrees C. Samples were taken for metal ion release determination using inductively coupled plasma-mass spectrometry and the data analysed using a two-way anova followed by a one-way anova. The surface roughness of each disc was measured using a Talysurf contact profilometer before and after bleaching and the data analysed using a paired t-test. With the exception of gold, the differences in metal ion concentration after treatment with 0% (control) and each of 3%, 10% and 30% HP (w/v) were statistically significant (P alloys increased with increasing HP concentrations (over 3000% increase in Ni and 1400% increase in Pd ions were recorded when HP concentration increased from 0% to 30%). Surface roughness values of the samples before and after bleaching were not significantly different (P > 0.05) Exposure of the two dental casting alloys to HP solutions increased metal ion release of all the elements except gold.

  4. Biological Effects of Drug-Free Alginate Beads Cross-Linked by Copper Ions Prepared Using External Ionotropic Gelation.

    Science.gov (United States)

    Pavelková, M; Kubová, K; Vysloužil, J; Kejdušová, M; Vetchý, D; Celer, V; Molinková, D; Lobová, D; Pechová, A; Vysloužil, J; Kulich, P

    2017-05-01

    External ionotropic gelation offers a unique possibility to entrap multivalent ions in a polymer structure. The aim of this experimental study was to prepare new drug-free sodium alginate (ALG) particles cross-linked by Cu 2+ ions and to investigate their technological parameters (particle size, sphericity, surface topology, swelling capacity, copper content, release of Cu 2+ ions, mucoadhesivity) and biological activity (cytotoxicity and efficiency against the most common vaginal pathogens-Herpes simplex, Escherichia coli, Candida albicans) with respect to potential vaginal administration. Beads prepared from NaALG dispersions (3 or 4%) were cross-linked by Cu 2+ ions (0.5 or 1.0 M CuCl 2 ) using external ionotropic gelation. Prepared mucoadhesive beads with particle size over 1000 μm exhibited sufficient sphericity (all ˃0.89) and copper content (214.8-249.07 g/kg), which increased with concentration of polymer and hardening solution. Dissolution behaviour was characterized by extended burst effect, followed by 2 h of copper release. The efficiency of all samples against the most common vaginal pathogens was observed at cytotoxic Cu 2+ concentrations. Anti-HSV activity was demonstrated at a Cu 2+ concentration of 546 mg/L. Antibacterial activity of beads (expressed as minimum inhibition concentration, MIC) was influenced mainly by the rate of Cu 2+ release which was controlled by the extent of swelling capacity. Lower MIC values were found for E. coli in comparison with C. albicans. Sample ALG-3_1.0 exhibited the fastest copper release and was proved to be the most effective against both bacteria. This could be a result of its lower polymer concentration in combination with smaller particle size and thus larger surface area.

  5. Studies on measurement of chloride ion concentration in concrete structures with long-period grating sensors

    Science.gov (United States)

    Tang, Jaw-Luen; Chiang, Tsung-Yu; Chang, Hsiang-Ping; Wang, Jian-Neng

    2006-03-01

    We report the development and demonstration of a simple and low-cost long-period grating (LPG) sensor for chloride ion concentration measurement in concrete structures. The LPG sensor is extremely sensitive to the refractive index of the medium surrounding the cladding surface of the sensing grating, thus allowing it to be used as an ambient index sensor or chemical concentration indicator with high stability and reliability. We have measured chloride ion levels in a concrete sample immersed in salt water solution with different weight concentration ranging from 0 % to 20 %, and results showed that the LPG sensor exhibited a linear decrease in the transmission loss and resonance wavelength shift when the concentration increased. The measurement accuracy for concentration of salt in water solution is estimated to be 0.6 % and the limit of detection for chloride ion is about 0.04 %. To further enhance its sensitivity for chloride concentrations, we have coated gold nanoparticles on the grating surface of the LPG sensor. The sensing mechanism is based on the sensitivity of localized surface plasmon resonance of self-assembled Au colloids on the grating portion of the LPG. With this method, a factor of two increases in sensitivity of detecting chemical solution concentrations was obtained. The advantage of this type of the sensor is relatively simple of construction and ease of use. Moreover, the sensor has the potential capability for on-site, in vivo, and remote sensing, and has the potential use for disposable sensors.

  6. Behaviour of radionuclides in biological and non-biological processes at very low concentrations

    International Nuclear Information System (INIS)

    Sinnaeve, J.; Frissel, M.J.; Klugt, N. van der; Geijn, S.C. van de.

    1980-01-01

    Four experiments using a 'biological exchange column', i.e. a cut papyrus stem were carried out. Prior to the passage of the labelled solution containing 250 μCi 137 Cs.l -1 , and 1 μCi 134 Cs.l -1 , the exchange sites of the stem were protonated. Two treatments were carried out, the first with 10 -4 M stable caesium in the labelled solution and the second with 10 -4 M potassium. After detection of the front of activity half way up the stem, 5 cm segments of the stem were cut and counted. (Auth.)

  7. A synthetic ion transporter that disrupts autophagy and induces apoptosis by perturbing cellular chloride concentrations

    Science.gov (United States)

    Busschaert, Nathalie; Park, Seong-Hyun; Baek, Kyung-Hwa; Choi, Yoon Pyo; Park, Jinhong; Howe, Ethan N. W.; Hiscock, Jennifer R.; Karagiannidis, Louise E.; Marques, Igor; Félix, Vítor; Namkung, Wan; Sessler, Jonathan L.; Gale, Philip A.; Shin, Injae

    2017-07-01

    Perturbations in cellular chloride concentrations can affect cellular pH and autophagy and lead to the onset of apoptosis. With this in mind, synthetic ion transporters have been used to disturb cellular ion homeostasis and thereby induce cell death; however, it is not clear whether synthetic ion transporters can also be used to disrupt autophagy. Here, we show that squaramide-based ion transporters enhance the transport of chloride anions in liposomal models and promote sodium chloride influx into the cytosol. Liposomal and cellular transport activity of the squaramides is shown to correlate with cell death activity, which is attributed to caspase-dependent apoptosis. One ion transporter was also shown to cause additional changes in lysosomal pH, which leads to impairment of lysosomal enzyme activity and disruption of autophagic processes. This disruption is independent of the initiation of apoptosis by the ion transporter. This study provides the first experimental evidence that synthetic ion transporters can disrupt both autophagy and induce apoptosis.

  8. Continuous measurement of the radon concentration in water using electret ion chamber method

    International Nuclear Information System (INIS)

    Dua, S.K.; Hopke, P.K.

    1992-10-01

    A radon concentration of 300 pCi/L has been proposed by the US Environmental Protection Agency as a limit for radon dissolved in municipal drinking water supplies. There is therefore a need for a continuous monitor to insure that the daily average concentration does not exceed this limit. In order to calibrate the system, varying concentrations of radon in water have been generated by bubbling radon laden air through a dynamic flowthrough water system. The value of steady state concentration of radon in water from this system depends on the concentration of radon in air, the air bubbling rate, and the water flow rate. The measurement system has been designed and tested using a 1 L volume electret ion chamber to determine the radon in water. In this dynamic method, water flows directly through the electret ion chamber. Radon is released to the air and measured with the electret. A flow of air is maintained through the chamber to prevent the build-up of high radon concentrations and too rapid discharge of the electret. It was found that the system worked well when the air flow was induced by the application of suction. The concentration in the water was calculated from the measured concentration in air and water and air flow rates. Preliminary results suggest that the method has sufficient sensitivity to measure concentrations of radon in water with acceptable accuracy and precision

  9. Determination of anionic concentrations in ground water samples using ion chromatography

    International Nuclear Information System (INIS)

    Prathibha, P.; Saradhi, I.V.; Pandit, G.G.; Puranik, V.D.

    2011-01-01

    Ion chromatography is a powerful separation technique for the quantitative measurement of anions in aqueous samples as well as in soil, sediment and air particulate samples leached in aqueous solutions. Ion chromatographic technique is developed by making use of suppressed ion conductivity detection (Small et.al.,1975) and it is a rapid multi ion analysis technique. The time, processing and effort required for the analysis of anions is much less compared to other techniques available such as ion selective electrode technique. In the present paper ground water samples collected around New BARC campus, Visakhapatnam are analyzed for anions using Ion chromatograph. The data generated will establish the current baseline status of the ionic contaminants in the study area. Groundwater samples are collected at 13 locations around BARC Vizag campus covering 30 km radius in September, 2009, April and July, 2010. The water samples include samples from hand pump and open wells in villages. The water samples are analyzed for fluoride, chloride, nitrate and sulphate using Metrohm make Ion chromatograph. The fluoride concentration in samples varied from 0.22 to 1.26 ppm, chloride from 18.7 to 810.9, nitrate from 1.34 to 378.5 ppm and sulphate from 13.29 to 250.69 ppm. No significant seasonal variations are observed in the samples collected from various locations except chloride at two locations. Ions Chromatograph is found to be a useful tool for simultaneous analysis of environmental samples with good accuracy where the concentrations of anions vary within an order of magnitude among them themselves. (author)

  10. Biological and medical research with accelerated heavy ions at the Bevalac, 1977-1980

    International Nuclear Information System (INIS)

    Pirruccello, M.C.; Tobias, C.A.

    1980-11-01

    Separate abstracts were prepared for the 46 papers presented in this progress report. This report is a major review of studies with accelerated heavy ions carried out by the Biology and Medicine Division of Lawrence Berkeley Laboratory from 1977 to 1980

  11. Biological and medical research with accelerated heavy ions at the Bevalac, 1977-1980. [Lead abstract

    Energy Technology Data Exchange (ETDEWEB)

    Pirruccello, M.C.; Tobias, C.A. (eds.)

    1980-11-01

    Separate abstracts were prepared for the 46 papers presented in this progress report. This report is a major review of studies with accelerated heavy ions carried out by the Biology and Medicine Division of Lawrence Berkeley Laboratory from 1977 to 1980. (KRM)

  12. Effect of metal ion concentration on the biosorption of Pb2+ and ...

    African Journals Online (AJOL)

    The influence of initial metal ion concentration of the batch sorption of Pb2+ and Cd2+ onto a low-cost biosorbent was investigated. The experimental results were analysed in terms of Langmuir and Freundlich isotherms. According to the evaluation using Langmuir equation, the monolayer sorption capacity obtained were ...

  13. Combined effects of water temperature and copper ion concentration on catalase activity in Crassostrea ariakensis

    Science.gov (United States)

    Wang, Hui; Yang, Hongshuai; Liu, Jiahui; Li, Yanhong; Liu, Zhigang

    2015-07-01

    A central composite experimental design and response surface method were used to investigate the combined effects of water temperature (18-34°C) and copper ion concentration (0.1-1.5 mg/L) on the catalase (CAT) activity in the digestive gland of Crassostrea ariakensis. The results showed that the linear effects of temperature were significant ( P0.05), and the quadratic effects of copper ion concentration were significant ( P0.05), and the effect of temperature was greater than that of copper ion concentration. A model equation of CAT enzyme activity in the digestive gland of C. ariakensis toward the two factors of interest was established, with R 2, Adj. R 2 and Pred. R 2 values as high as 0.943 7, 0.887 3 and 0.838 5, respectively. These findings suggested that the goodness of fit to experimental data and predictive capability of the model were satisfactory, and could be practically applied for prediction under the conditions of the study. Overall, the results suggest that the simultaneous variation of temperature and copper ion concentration alters the activity of the antioxidant enzyme CAT by modulating active oxygen species metabolism, which may be utilized as a biomarker to detect the effects of copper pollution.

  14. Electrochemical activation and inhibition of neuromuscular systems through modulation of ion concentrations with ion-selective membranes

    Science.gov (United States)

    Song, Yong-Ak; Melik, Rohat; Rabie, Amr N.; Ibrahim, Ahmed M. S.; Moses, David; Tan, Ara; Han, Jongyoon; Lin, Samuel J.

    2011-12-01

    Conventional functional electrical stimulation aims to restore functional motor activity of patients with disabilities resulting from spinal cord injury or neurological disorders. However, intervention with functional electrical stimulation in neurological diseases lacks an effective implantable method that suppresses unwanted nerve signals. We have developed an electrochemical method to activate and inhibit a nerve by electrically modulating ion concentrations in situ along the nerve. Using ion-selective membranes to achieve different excitability states of the nerve, we observe either a reduction of the electrical threshold for stimulation by up to approximately 40%, or voluntary, reversible inhibition of nerve signal propagation. This low-threshold electrochemical stimulation method is applicable in current implantable neuroprosthetic devices, whereas the on-demand nerve-blocking mechanism could offer effective clinical intervention in disease states caused by uncontrolled nerve activation, such as epilepsy and chronic pain syndromes.

  15. Chromium and cobalt ion concentrations in blood and serum following various types of metal-on-metal hip arthroplasties

    DEFF Research Database (Denmark)

    Jantzen, Christopher; Jørgensen, Henrik L; Duus, Benn R

    2013-01-01

    Widely different metal ion concentrations in blood and serum have been reported with metal-on-metal (MoM) implants. We reviewed the literature on blood and serum ion concentrations of chromium (Cr) and cobalt (Co) following various MoM hip arthroplasties.......Widely different metal ion concentrations in blood and serum have been reported with metal-on-metal (MoM) implants. We reviewed the literature on blood and serum ion concentrations of chromium (Cr) and cobalt (Co) following various MoM hip arthroplasties....

  16. Application of secondary ion mass spectrometry (SIMS) to biological sample analysis

    International Nuclear Information System (INIS)

    Tamura, Hifumi

    1990-01-01

    Some major issues and problems related with the analysis of biological samples are discussed, focusing on demonstrated and possible solutions and the application of secondary ion mass spectrometry (SIMS) to investigation of the composition of biological samples. The effective use of secondary electrons in combination with negative ions is most practical for the analysis of biological samples. Regardless of whether positive or negative ions are used, the electric potential at the surface of a sample stays around a constant value because of the absense of the accumulation of electric charges at the surface, leading to almost complete avoidance of the charging of the biological sample. A soft tissue sample can suffer damage to the tissue or migration of atoms in removing water from the sample. Some processes including fixation and freeze drying are available to prevent this. The application of SIMS to biological analysis is still in the basic research stage and further studies will be required to develop practical methods. Possible areas of its application include medicine, pathology, toxicology, pharmacology, plant physiology and other areas related with marine life and marine contamination. (N.K.)

  17. Alkali Metal Ion Complexes with Phosphates, Nucleotides, Amino Acids, and Related Ligands of Biological Relevance. Their Properties in Solution.

    Science.gov (United States)

    Crea, Francesco; De Stefano, Concetta; Foti, Claudia; Lando, Gabriele; Milea, Demetrio; Sammartano, Silvio

    2016-01-01

    Alkali metal ions play very important roles in all biological systems, some of them are essential for life. Their concentration depends on several physiological factors and is very variable. For example, sodium concentrations in human fluids vary from quite low (e.g., 8.2 mmol dm(-3) in mature maternal milk) to high values (0.14 mol dm(-3) in blood plasma). While many data on the concentration of Na(+) and K(+) in various fluids are available, the information on other alkali metal cations is scarce. Since many vital functions depend on the network of interactions occurring in various biofluids, this chapter reviews their complex formation with phosphates, nucleotides, amino acids, and related ligands of biological relevance. Literature data on this topic are quite rare if compared to other cations. Generally, the stability of alkali metal ion complexes of organic and inorganic ligands is rather low (usually log K  Na(+) > K(+) > Rb(+) > Cs(+). For example, for citrate it is: log K ML = 0.88, 0.80, 0.48, 0.38, and 0.13 at 25 °C and infinite dilution. Some considerations are made on the main aspects related to the difficulties in the determination of weak complexes. The importance of the alkali metal ion complexes was also studied in the light of modelling natural fluids and in the use of these cations as probes for different processes. Some empirical relationships are proposed for the dependence of the stability constants of Na(+) complexes on the ligand charge, as well as for correlations among log K values of NaL, KL or LiL species (L = generic ligand).

  18. Treatment planning for heavy ion radiotherapy: calculation and optimization of biologically effective dose

    International Nuclear Information System (INIS)

    Kraemer, M.; Scholz, M.

    2000-09-01

    We describe a novel approach to treatment planning for heavy ion radiotherapy based on the local effect model (LEM) which allows to calculate the biologically effective dose not only for the target region but for the entire irradiation volume. LEM is ideally suited to be used as an integral part of treatment planning code systems for active dose shaping devices like the GSI raster scan system. Thus, it has been incorporated into our standard treatment planning system for ion therapy (TRiP). Single intensity modulated fields can be optimized with respect to homogeneous biologically effective dose. The relative biological effectiveness (RBE) is calculated separately for each voxel of the patient CT. Our radiobiologically oriented code system is in use since 1995 for the planning of irradiation experiments with cell cultures and animals such as rats and minipigs. Since 1997 it is in regular and successful use for patient treatment planning. (orig.)

  19. Determination of molybdenum (VI) in sea water with preliminary concentration by the method of ion flotation

    International Nuclear Information System (INIS)

    Andreeva, I. Yu.; Drapchinskaya, O.L.; Lebedeva, L.I.

    1985-01-01

    The purpose of this paper is to assess the feasibility of using the method of ion flotation for the concentration of microamounts of molybdenum (VI) during determination in sea water. The ion flotation method is used for the purification of industrial sewage from the ions of nonferrous metals, including molybdenum (VI) with its content of up to 50 mg/liter. A 1.10 -4 M solution of sodium molybdate in 0.1M NaOH was used. The effect of different factors on the ion flotation process of molybdenum (VI) was investigated: pH of the solution, flotation times, concentrations of surface-active substances (SAS), molybdenum (IV), extraneous salts. Data presented show that the ion flotation method in conjunction with the photometric method of determining molybdenum with brompyrogallol red (BPR) and cetylpridinium chloride (CP) (limit of detection 0.02 micrograms/liter) allows the content of molybdenum (VI) in sea water to be established with sufficient reliability and reproducibility

  20. Proceedings of the 4th workshop on ion-beam-applied biology

    International Nuclear Information System (INIS)

    Kobayashi, Yasuhiko; Funayama, Tomoo; Wada, Seiichi; Hamada, Nobuyuki

    2005-09-01

    In order to promote research on biological application using ion beam at TIARA, we have annually hold the Workshop on Ion-beam-applied Biology at JAERI Takasaki since 2002. The 4th workshop entitled 'New Frontiers of Biological Research using microbeam - Application to Radio-microsurgery and Cellular Response to Radiations -' was held on June 22nd, 2005, aimed to overview the recent progress in microbeam-applied researches, and discuss the future direction of application of microbeam not to researches in life science and biotechnology, but also to clinical medicine. This workshop was hosted by JAERI Takasaki, with the cooperation of The Ion Beam Breeding Society, The Japan Radiation Research Society, The Japanese Society for Biological Sciences in Space, The Kanto-Kohetsu Branch of The Atomic Energy Society of Japan, and The Japan Radioisotope Association. There were 104 participants including clinicians attended from universities, public research institutions, and private companies. The papers presented in the workshop were about the ion-beam-applied biological researches at JAERI, the present status of microbeam facilities in Japan and foreign countries, and the microbeam-based analyses of damage repair machinery in insects and radiation-induced bystander effects. It was realized again that microbeam is quite useful for functional analyses by targeted disruption of specific tissues in bio-organisms, and is of critical importance in investigating biological influences of low-dose radiations as well as in its radiological application. These researches using microbeam are expected to further march on. The 13 of the presented papers are indexed individually. (J.P.N.)

  1. Effect of organic solvents on desorption and atomic absorption determination of heavy metal ions after ion exchange concentration

    International Nuclear Information System (INIS)

    Pilipenko, A.T.; Safronova, V.G.; Zakrevskaya, L.V.

    1986-01-01

    The effect of organic solvents (acetone, methylethylketone, dioxane, ethanol) on desorption of Cu, Mn, Co, Cd, Zn, Pb, Ni from cationite KU-23 ion exchange resin and on the detection limits of their atomic absorption determination has been examined. Cobalt and cadmium can be separated quantitatively using desorption by a mixture of HCl and acetone. Addition of an organic solvent results in a higher absorbance, mainly due to a high rate and efficiency of atomization. Acetone has proved to be the best solvent: addition of 60 vol. % of this solvent to the concentrate provides 2 times lower detection limits for the heavy metas in water

  2. Diffusion of ion-implanted B in high concentration P- and As-doped silicon

    International Nuclear Information System (INIS)

    Fair, R.B.; Pappas, P.N.

    1975-01-01

    The diffusion of ion-implanted B in Si in the presence of a uniform background of high concentration P or As was studied by correlating numerical profile calculations with profiles determined by secondary-ion mass spectrometry (SIMS). Retarded B diffusion is observed in both As- and P-doped Si, consistent with the effect of the local Fermi-level position in the Si band gap on B diffusivity, D/sub B/. It is shown that D/sub B/ is linearly dependent on the free hole concentration, p, over the range 0.1 less than p/n/sub ie/ less than 30, where n/sub ie/ is the effective intrinsic electron concentration. This result does not depend on the way in which the background dopant has been introduced (implantation predeposition or doped-oxide source), nor the type of dopant used (P or As). (U.S.)

  3. A Simplified Model to Estimate the Concentration of Inorganic Ions and Heavy Metals in Rivers

    Directory of Open Access Journals (Sweden)

    Clemêncio Nhantumbo

    2016-10-01

    Full Text Available This paper presents a model that uses only pH, alkalinity, and temperature to estimate the concentrations of major ions in rivers (Na+, K+, Mg2+, Ca2+, HCO3−, SO42−, Cl−, and NO3− together with the equilibrium concentrations of minor ions and heavy metals (Fe3+, Mn2+, Cd2+, Cu2+, Al3+, Pb2+, and Zn2+. Mining operations have been increasing, which has led to changes in the pollution loads to receiving water systems, meanwhile most developing countries cannot afford water quality monitoring. A possible solution is to implement less resource-demanding monitoring programs, supported by mathematical models that minimize the required sampling and analysis, while still being able to detect water quality changes, thereby allowing implementation of measures to protect the water resources. The present model was developed using existing theories for: (i carbonate equilibrium; (ii total alkalinity; (iii statistics of major ions; (iv solubility of minerals; and (v conductivity of salts in water. The model includes two options to estimate the concentrations of major ions: (1 a generalized method, which employs standard values from a world-wide data base; and (2 a customized method, which requires specific baseline data for the river of interest. The model was tested using data from four monitoring stations in Swedish rivers with satisfactory results.

  4. Determination of mercury concentration in biological materials by neutron activation analysis

    International Nuclear Information System (INIS)

    Munoz, L.; Gras, N.; Cortes, E.; Cassorla, V.

    1983-01-01

    The objective of this work was to obtain a confident analytical method for measuring the mercury concentration in biological materials. Destructive neutron activation analysis was used for this purpose and a radiochemical separation method was studied to isolate the mercury from its main interferences: sodium and phosphorus, because these elements in biological materials are in high concentrations. The method developed was based on the copper amalgamation under controlled conditions. Yield and reproductibility studies were performed using 203 Hg as radioactive tracer. Finally, food samples of regular consumption were analyzed and the results were compared with those recommended by FAO/WHO. (Author)

  5. Heavy-ion microbeam system at JAEA-Takasaki for microbeam biology

    International Nuclear Information System (INIS)

    Funayama, Tomoo; Wada, Seiichi; Yokota, Yuichiro

    2008-01-01

    Research concerning cellular responses to low dose irradiation, radiation-induced bystander effects, and the biological track structure of charged particles has recently received particular attention in the field of radiation biology. Target irradiation employing a microbeam represents a useful means of advancing this research by obviating some of the disadvantages associated with the conventional irradiation strategies. The heavy-ion microbeam system at Japan Atomic Energy Agency (JAEA)-Takasaki, which was planned in 1987 and started in the early 1990's, can provide target irradiation of heavy charged particles to biological material at atmospheric pressure using a minimum beam size 5 μm in diameter. A variety of biological material has been irradiated using this microbeam system including cultured mammalian and higher plant cells, isolated fibers of mouse skeletal muscle, silkworm (Bombyx mori) embryos and larvae, Arabidopsis thaliana roots, and the nematode Caenorhabditis elegans. The system can be applied to the investigation of mechanisms within biological organisms not only in the context of radiation biology, but also in the fields of general biology such as physiology, developmental biology and neurobiology, and should help to establish and contribute to the field of 'microbeam biology'. (author)

  6. Effects of ion concentration on thermally-chargeable double-layer supercapacitors

    Science.gov (United States)

    Lim, Hyuck; Lu, Weiyi; Chen, Xi; Qiao, Yu

    2013-11-01

    The concept of thermally-chargeable supercapacitor was discussed and validated experimentally. As two double-layer supercapacitor-type devices were placed at different temperatures and connected, due to the thermal dependence of surface charge structures, the electrode potentials became different, and thermal energy could be harvested and stored as electric energy. The important effect of ion concentration was investigated. The results were quite different from the prediction of conventional surface theory, which should be attributed to the unique behaviors of the ions confined in the nanoporous electrodes.

  7. Modeling the concentration-dependent permeation modes of the KcsA potassium ion channel.

    Science.gov (United States)

    Nelson, Peter Hugo

    2003-12-01

    The potassium channel from Streptomyces lividans (KcsA) is an integral membrane protein with sequence similarity to all known potassium channels, particularly in the selectivity filter region. A recently proposed model for ion channels containing either n or (n-1) single-file ions in their selectivity filters [P. H. Nelson, J. Chem. Phys. 177, 11396 (2002)] is applied to published KcsA channel K+ permeation data that exhibit a high-affinity process at low concentrations and a low-affinity process at high concentrations [M. LeMasurier et al., J. Gen. Physiol. 118, 303 (2001)]. The kinetic model is shown to provide a reasonable first-order explanation for both the high- and low-concentration permeation modes observed experimentally. The low-concentration mode ([K+]200 mM) has a 200-mV dissociation constant of 1100 mM and a conductance of 500 pS. Based on the permeation model, and x-ray analysis [J. H. Morais-Cabral et al., Nature (London) 414, 37 (2001)], it is suggested that the experimentally observed K+ permeation modes correspond to an n=3 mechanism at high concentrations and an n=2 mechanism at low concentrations. The ratio of the electrical dissociation distances for the high- and low-concentration modes is 3:2, also consistent with the proposed n=3 and n=2 modes. Model predictions for K+ channels that exhibit asymmetric current-voltage (I-V) curves are presented, and further validation of the kinetic model via molecular simulation and experiment is discussed. The qualitatively distinct I-V characteristics exhibited experimentally by Tl+, NH+4, and Rb+ ions at 100 mM concentration can also be explained using the model, but more extensive experimental tests are required for quantitative validation of the model predictions.

  8. Potentiometric Sensor for Real-Time Monitoring of Multivalent Ion Concentrations in Molten Salt

    International Nuclear Information System (INIS)

    Zink, Peter A.; Jue, Jan-Fong; Serrano, Brenda E.; Fredrickson, Guy L.; Cowan, Ben F.; Herrmann, Steven D.; Li, Shelly X.

    2010-01-01

    Electrorefining of spent metallic nuclear fuel in high temperature molten salt systems is a core technology in pyroprocessing, which in turn plays a critical role in the development of advanced fuel cycle technologies. In electrorefining, spent nuclear fuel is treated electrochemically in order to effect separations between uranium, noble metals, and active metals, which include the transuranics. The accumulation of active metals in a lithium chloride-potassium chloride (LiCl-KCl) eutectic molten salt electrolyte occurs at the expense of the UCl3-oxidant concentration in the electrolyte, which must be periodically replenished. Our interests lie with the accumulation of active metals in the molten salt electrolyte. The real-time monitoring of actinide concentrations in the molten salt electrolyte is highly desirable for controlling electrochemical operations and assuring materials control and accountancy. However, real-time monitoring is not possible with current methods for sampling and chemical analysis. A new solid-state electrochemical sensor is being developed for real-time monitoring of actinide ion concentrations in a molten salt electrorefiner. The ultimate function of the sensor is to monitor plutonium concentrations during electrorefining operations, but in this work gadolinium was employed as a surrogate material for plutonium. In a parametric study, polycrystalline sodium beta double-prime alumina (Na-β(double p rime)-alumina) discs and tubes were subject to vapor-phase exchange with gadolinium ions (Gd3+) using a gadolinium chloride salt (GdCl3) as a precursor to produce gadolinium beta double-prime alumina (Gd-β(double p rime)-alumina) samples. Electrochemical impedance spectroscopy and microstructural analysis were performed on the ion-exchanged discs to determine the relationship between ion exchange and Gd3+ ion conductivity. The ion-exchanged tubes were configured as potentiometric sensors in order to monitor real-time Gd3+ ion concentrations in

  9. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    International Nuclear Information System (INIS)

    Xu Gang; Wang Xiaoteng; Gan Cailing; Fang Yanqiong; Zhang Meng

    2012-01-01

    Highlights: ► We analyzed biological effects of N + implantation on dry Jatropha curcas seed. ► N + implantation greatly decreased seedling survival rate. ► At doses beyond 15 × 10 16 ion cm −2 , biological repair took place. ► CAT was essential for H 2 O 2 removal. POD mainly functioned as seed was severely hurt. ► HAsA–GSH cycle mainly contributed to the regeneration of HAsA. - Abstract: To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N + with energy of 25 keV was applied to treat the dry seed at six different doses. N + beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 10 16 to 15 × 10 16 ions cm −2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 10 16 ion cm −2 , biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 10 16 ions cm −2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA–GSH cycle appeared to be for regeneration of HAsA.

  10. A novel method for the in situ determination of concentration gradients in the electrolyte of Li-ion Batteries

    NARCIS (Netherlands)

    Zhou, J.; Danilov, D.; Notten, P.H.L.

    2006-01-01

    An electrochemical method has been developed for the in situ determination of concentration gradients in the electrolyte of sealed Li-ion batteries by measuring the potential difference between microreference electrodes. Formulas relating the concentration gradient and the potential difference

  11. submitter Biologically optimized helium ion plans: calculation approach and its in vitro validation

    CERN Document Server

    Mairani, A; Magro, G; Tessonnier, T; Kamp, F; Carlson, D J; Ciocca, M; Cerutti, F; Sala, P R; Ferrari, A; Böhlen, T T; Jäkel, O; Parodi, K; Debus, J; Abdollahi, A; Haberer, T

    2016-01-01

    Treatment planning studies on the biological effect of raster-scanned helium ion beams should be performed, together with their experimental verification, before their clinical application at the Heidelberg Ion Beam Therapy Center (HIT). For this purpose, we introduce a novel calculation approach based on integrating data-driven biological models in our Monte Carlo treatment planning (MCTP) tool. Dealing with a mixed radiation field, the biological effect of the primary $^4$He ion beams, of the secondary $^3$He and $^4$He (Z  =  2) fragments and of the produced protons, deuterons and tritons (Z  =  1) has to be taken into account. A spread-out Bragg peak (SOBP) in water, representative of a clinically-relevant scenario, has been biologically optimized with the MCTP and then delivered at HIT. Predictions of cell survival and RBE for a tumor cell line, characterized by ${{(\\alpha /\\beta )}_{\\text{ph}}}=5.4$ Gy, have been successfully compared against measured clonogenic survival data. The mean ...

  12. Concentration effect on the spectroscopic behavior of Tb3+ ions in zinc phosphate glasses

    International Nuclear Information System (INIS)

    Kesavulu, C.R.; Almeida Silva, Anielle Christine; Dousti, M.R.; Dantas, Noelio Oliveira; Camargo, A.S.S. de; Catunda, Tomaz

    2015-01-01

    Zinc phosphate glasses (PZABPTb) in the compositional system: P 2 O 5 –ZnO–Al 2 O 3 –BaO–PbO doped with variable Tb 3+ concentrations (1–5 wt% Tb 2 O 3 ) were prepared and characterized through absorption, excitation, emission and intensity decay rate measurements. The Judd–Ofelt model has been adopted to evaluate the radiative properties of the 5 D 4 → 7 F 6–3 emission transitions. The effect of Tb 3+ ion concentration on the emissions from the 5 D 3,4 excited levels is discussed in detail. Analysis of the intensity decay curves corresponding to blue and green emissions from levels 5 D 3 and 5 D 4 , respectively, allowed determination of effective lifetimes, which confirmed the Tb 3+ ion concentration quenching of the blue emission in these glasses. The decay curves for the 5 D 3 level are found to be non-exponential in nature for all the studied concentrations due to ion–ion energy transfer through cross-relaxation. In an attempt to identify the origin of the energy transfer mechanism, the decay curves were well fitted to the Inokuti–Hirayama model for S=6, which indicates that the energy transfer process is of dipole–dipole type. The optical band gap energy (E opt ) has been evaluated taking into account the ultraviolet edge of absorption spectra. - Highlights: • Tb 3+ -doped zinc phosphate glasses have been prepared by melt quenching technique. • Spectroscopic parameters were evaluated using the Judd–Ofelt theory. • Effects of Tb 3+ concentration on luminescence of the glasses were studied. • Strong intense laser transition for Tb 3+ ion in PZABPTb glasses is 5 D 4 → 7 F 5 (0.54 μm). • PZABPTb glasses could be used in the development of green color display devices and solid state visible lasers

  13. Measurement of chloride-ion concentration with long-period grating technology

    Science.gov (United States)

    Tang, Jaw-Luen; Wang, Jian-Neng

    2007-06-01

    A simple and low-cost long-period fiber grating (LPG) sensor suited for chloride-ion concentration measurement is presented. The LPG sensor is found to be sensitive to the refractive index of the medium around the cladding surface of the sensing grating, thus offering the prospect of development of practical sensors such as an ambient index sensor or a chemical concentration indicator with high stability and reliability. We measured chloride ions in a typical concrete sample immersed in salt water solutions with different weight concentrations ranging from 0% to 25%. Results show that the LPG sensor exhibited a linear decrease in the transmission loss and resonance wavelength shift when the concentration increased. The measurement accuracy for the concentration of salt in water solution is estimated to be 0.6% and the limit of detection for chloride ions is about 0.04%. To further enhance its sensitivity for chloride concentrations, we coated a monolayer of colloidal gold nanoparticles as the active material on the grating surface of the LPG sensor. The operating principle of sensing is based on the sensitivity of localized surface plasmon resonance of self-assembled gold colloids on the grating section of the LPG. With this method, a factor of two increase in the sensitivity of detecting chemical solution concentrations was obtained. The advantages of this type of fiber-optic sensor are that it is compact, relatively simple to construct and easy to use. Moreover, the sensor has the potential capability for on-site, in vivo and remote sensing, and it has potential use as a disposable sensor.

  14. Aminoglycoside antibiotics as a tool for the study of the biological role of calcium ions. Historical overview.

    Science.gov (United States)

    Corrado, A P; de Morais, I P; Prado, W A

    1989-01-01

    Beginning with the pioneering work of Vital-Brazil and Corrado (1957), which suggested a possible interaction between aminoglycoside antibiotics (AGA) and calcium ions at the neuromuscular junction, the authors review the studies that demonstrated the existence of a competitive antagonism between AGA and calcium ions. In view of the low liposolubility of AGA and their inability to cross biological membranes, this antagonism seems to occur exclusively at calcium-binding sites at the level of the outer opening of calcium channels of the N-subtype, which are also the sites of interaction of omega-conotoxin. Being highly water soluble, AGA are easily removed from their binding sites with a consequent rapid reversal of their effects, a factor of primary importance to explain their wide use as tools in the pharmacological analysis of the study of the biological role of calcium ion on the membrane's outer surface. This use has advantages over the use of inorganic di- and trivalent cations such as Mg2+, Mn2+, Cd2+, Ni2+, La3+, etc., since the latter, though they are considered to be the most specific competitive antagonists of calcium ions, may induce biphasic effects due to their ability to cross the membranes and replace calcium and/or increase intracellular calcium concentration. The performance of AGA is also superior when compared with the so-called "specific" organic calcium antagonists--verapamil and nifedipine derivatives--since the latter, in addition to inducing possible biphasic effects, antagonize calcium in a non-competitive manner. Finally, the authors remark that AGA-Ca2+ antagonism relevance is not limited only to basic aspects and that it may have therapeutic implications since it provides alternatives for reducing the toxic adverse effects of this important group of antibiotics.

  15. The influence of biological and environmental factors on metallothionein concentration in the blood.

    Science.gov (United States)

    Kowalska, Katarzyna; Bizoń, Anna; Zalewska, Marta; Milnerowicz, Halina

    2015-01-01

    The concentration of metallothionein (MT), a low-molecular-weight protein, is regulated by many factors, primarily metals (zinc, cadmium, copper), cytokines, glucocorticoides and free radicals. These factors are determined by such aspects of human biology as gender, pregnancy and age, as well as by environmental factors including the use of oral contraceptives and cigarette smoking, all which may affect MT levels in the body. The aim of this study was to investigate the influence of these biological and environmental factors on MT concentrations in erythrocyte lysate and in plasma. MT concentrations were determined by a two-step direct enzyme-linked immunosorbent assay. Evaluation of exposure to cigarette smoking was performed by checking cotinine levels in the plasma of subjects. The studies showed higher MT concentrations in both the erythrocyte lysate and plasma of women when compared to men. Furthermore, pregnancy causes an increase of MT concentration in plasma, while oral contraceptives cause an elevated concentration of MT in erythrocyte lysate. Age impacts plasma MT concentrations in men, whereas it does not affect concentrations of MT in erythrocyte lysate. Copyright © 2014 Elsevier GmbH. All rights reserved.

  16. Future strategy and puzzles of heavy ion beam mediated technique in genetic improvement of biological bodies

    International Nuclear Information System (INIS)

    Huang Qunce

    2007-01-01

    The 7 research puzzles in the genetic improvement of biological bodies made by ion beam mediated technique, are worth noticed. The technical ideas, including one mediated technique in physics, 2 significant subjects, 3 effective changes, the mediated evidences of 4 aspects and 5 biological characteristics, were particularly put forward according to the existing states in the field. The 2 significant subjects consist of the mechanics of the allogenetic materials entering into the acceptor and they being to be recombined. The 3 effective changes include from studying morphology to genetic laws, from researching M1 generation to the next generations, from determining the single character to the synthetic traits. The mediated evidences of 4 aspects come from morphology, physiology and biochemistry, molecule biology. The 5 biological characteristics are mainly reproduction, development, photosynthesis, bad condition-resistant and quality. (authors)

  17. Change of pH and Iron Ion Concentration During Photodegradation of TCE with Ferrioxalate/UVvis Process

    International Nuclear Information System (INIS)

    Hareyama, Wataru; Suto, Koichi; Inoue, Chihiro; Chida, Tadashi; Nakazawa, Hiroshi

    2006-01-01

    Recently, some studies show various organic compounds such as pesticides and dyes degraded with the irradiation of ultraviolet light and visible light in the presence of oxalic acid and ferric ion (ferrioxalate/UVvis process). The process has much advance than other technologies because it can utilize the wavelength of 300∼450nm and also under the condition of neutral pH. Chlorinated organic compounds such as trichloroethene (TCE), which have caused ground water pollution on a lot of sites, have never been applied by photodegradation with this process. In this study, we showed the degradation of TCE in the presence of oxalic acid and iron ion and the change of pH, ferric and ferrous ion concentration during the photodegradation of TCE with ferrioxalate/UV-vis process. TCE was degraded in the presence of oxalic acid and iron ion. In the reactions, the equilibrium of oxalate ion and iron ion is important since it determines the amount of ferrioxalate complex which absorbs light and induces the reactions of the degradation of TCE. Thus, the pH value and iron ion concentration are the important factors which determine the amount of ferrioxalate complex. The pH is nearly constant during the photodegradation of TCE. The ferrous ion concentration was decreased as soon as beginning photodegradation of TCE, and then the ferrous ion concentration and ferric ion concentration became constant

  18. Evolution of ion damage at 773K in Ni- containing concentrated solid-solution alloys

    Science.gov (United States)

    Shi, Shi; He, Mo-Rigen; Jin, Ke; Bei, Hongbin; Robertson, Ian M.

    2018-04-01

    Quantitative analysis of the impact of the compositional complexity in a series of Ni-containing concentrated solid-solution alloys, Ni, NiCo, NiFe, NiCoCr, NiCoFeCr, NiCoFeCrMn and NiCoFeCrPd, on the evolution of defects produced by 1 MeV Kr ion irradiation at 773 K is reported. The dynamics of the evolution of the damage structure during irradiation to a dose of 2 displacements per atom were observed directly by performing the ion irradiations in electron transparent foils in a transmission electron microscope coupled to an ion accelerator. The defect evolution was assessed through measurement of the defect density, defect size and fraction of perfect and Frank loops. These three parameters were dependent on the alloying element as well as the number of elements. The population of loops was sensitive to the ion dose and alloy composition as faulted Frank loops were observed to unfault to perfect loops with increasing ion dose. These dependences are explained in terms of the influence of each element on the lifetime of the displacement cascade as well as on defect formation and migration energies.

  19. Dependence of radiocaesium biological half-life in freshwater fish on water potassium concentration and temperature

    International Nuclear Information System (INIS)

    Carreiro, M.C.V.; Corisco, J.A.G.

    1998-01-01

    Short-term experiments (35-49 days) showed that the rate of cesium elimination from fish increases with increasing potassium concentration in water (the biological half-life decreases); this, however, is only true of the potassium concentration range of 0.35 to 3.5 ppm, whereas higher potassium concentrations do not seem to affect the elimination rate. Decrease in water temperature within the 20 degC to 5 degC range slows down the cesium elimination process. (P.A.)

  20. Isolation of transplutonium elements on ion exchangers from solutions of high salt concentration

    International Nuclear Information System (INIS)

    Guseva, L.I.; Tikhomirova, G.S.; Stepushkina, V.V.

    1985-01-01

    The behaviour of transplutonium elements (TPE) on cation and anion exchangers in aqueous alcoholic solutions of chlorides and nitrates of some alkali and alkaline earth metals depending on different factors: salt concentration, content of alcohol and of acid in the solution as well as the nature of a cation was studied. The data obtained were used to determine the optimal conditions of concentration of TPE on ion exchangers from solutions containing great quantities of salts. The advantages of the use of aqueous alcoholic solutions of nitric acid in the isolation of TPE are shown. (author)

  1. Flow injection spectrophotometric determination of low concentrations of orthosphate in natural waters employing ion exchange resin

    International Nuclear Information System (INIS)

    Pessenda, L.C.R.

    1981-01-01

    A simple and fast method for the determination of low concentrations of orthophosphate in natural waters is described. Ion exchange is incorporated into a flow injection system by usina a resin column in the sample loop of a proportion injector. Effects of sample aspiration rate, sampling time, eluting agent concentration, pumping rate of the sample carrier stream and interfaces, were investigated both using 32 PO 3- 4 or 31 PO 3- 4 with columns coupled to a gerger-muller detector and incorporated in a flow system with molybdenum blue colorinetry. (M.A.C.) [pt

  2. Spectroscopic Analysis of Ion Concentration Profile at Electrode/Electrolyte Interface by Interferometry

    Science.gov (United States)

    Moore, David; Saraf, Ravi

    2014-03-01

    Owing to the difference in Fermi levels at an electrode/electrolyte interface, ions form an electrical double layer (EDL) with ion concentrations well over 10-fold compared to bulk. The concentration profile of the EDL intrinsically affects the electrochemical reaction rates at the electrode, which is of great significance in many applications, such as batteries and biosensors. Conventionally, using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), the electrical properties of the EDL are represented as ``equivalent circuits'' consisting of the resistance to charge transfer (Rct), the double layer capacitance (Cdl) and a ``Warburg (constant phase) diffusion element'' that represents the long range diffusion of ions to the electrode. The translation to the well-understood physical structure can be lost as complicated effects are often lumped together. For example, the effect of subtle modification of the electrode surface by say, redox compounds, enzymes, or polymers is not directly measured, and must be inferred by capacitance changes. An interferometer method will be described to directly measure changes in concentration at the interface during redox process. This method in concert with CV or EIS performed concomitantly will lead to more information to model the diffuse layer for improved understanding of the kinetics of the reaction at different distances from the electrode. Applications to DNA and polymer adsorption binding will be discussed.

  3. Investigating the robustness of ion beam therapy treatment plans to uncertainties in biological treatment parameters

    CERN Document Server

    Boehlen, T T; Dosanjh, M; Ferrari, A; Fossati, P; Haberer, T; Mairani, A; Patera, V

    2012-01-01

    Uncertainties in determining clinically used relative biological effectiveness (RBE) values for ion beam therapy carry the risk of absolute and relative misestimations of RBE-weighted doses for clinical scenarios. This study assesses the consequences of hypothetical misestimations of input parameters to the RBE modelling for carbon ion treatment plans by a variational approach. The impact of the variations on resulting cell survival and RBE values is evaluated as a function of the remaining ion range. In addition, the sensitivity to misestimations in RBE modelling is compared for single fields and two opposed fields using differing optimization criteria. It is demonstrated for single treatment fields that moderate variations (up to +/-50\\%) of representative nominal input parameters for four tumours result mainly in a misestimation of the RBE-weighted dose in the planning target volume (PTV) by a constant factor and only smaller RBE-weighted dose gradients. Ensuring a more uniform radiation quality in the PTV...

  4. Biological effects of N+ ion implantation and UV radiation on streptomyces albus

    International Nuclear Information System (INIS)

    Wu Jian; Dai Guifu

    2005-01-01

    The results of both 30 keV N + ion implantation and UV irradiation of Streptomyces albus showed complicate biological effects. The 'saddle shape' pattern of the dose-dependent curve formed by N + ion implantation with low energy was studied, and it proved that vacuum was not the reason, and the fact, the 'saddle shape' curve may be regarded as a HRS/IRR (hyper-radiosensitivity/increased radiaoresistance) effect caused by low dose irradiation. But Streptomyces albus UV irradiated after vacuum treatment only showed IRR effect or hormesis (survival rate >100%). The streptomycin resistance mutation of Streptomyces albus caused by low energy N + ion implantation and UV irradiation was also studied. the results showed that UV radiation is one effective means for streptomyces albus breeding. (authors)

  5. Uranium uptake by baker's yeast (Saccharomyces cerevisiae) - development of a biological ion exchanger

    International Nuclear Information System (INIS)

    Oost, T.; Schoening, K.U.

    1991-01-01

    The use of micro-organisms for decontamination of, and heavy metal recovery from industrial waste water is a modern, low-cost, and environmentally friendly alternative to the conventional chemical and physical methods. The uptake of uranium by baker's yeast is investigated under the aspect of application in biotechnology. A novel, regenerable biological ion exchanger was produced by immobilisation of the yeast in agar gel. (orig.) [de

  6. Optimization of free ammonia concentration for nitrite accumulation in shortcut biological nitrogen removal process.

    Science.gov (United States)

    Chung, Jinwook; Shim, Hojae; Park, Seong-Jun; Kim, Seung-Jin; Bae, Wookeun

    2006-03-01

    A shortcut biological nitrogen removal (SBNR) utilizes the concept of a direct conversion of ammonium to nitrite and then to nitrogen gas. A successful SBNR requires accumulation of nitrite in the system and inhibition of the activity of nitrite oxidizers. A high concentration of free ammonia (FA) inhibits nitrite oxidizers, but unfortunately decreases the ammonium removal rate as well. Therefore, the optimal range of FA concentration is necessary not only to stabilize nitrite accumulation but also to achieve maximum ammonium removal. In order to derive such optimal FA concentrations, the specific substrate utilization rates of ammonium and nitrite oxidizers were measured. The optimal FA concentration range appeared to be 5-10 mg/L for the adapted sludge. The simulated results from the modified inhibition model expressed by FA and ammonium/nitrite concentrations were shown very similar to the experimental results.

  7. Nano-ranged low-energy ion-beam-induced DNA transfer in biological cells

    Energy Technology Data Exchange (ETDEWEB)

    Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wongkham, W. [Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Sangwijit, K.; Inthanon, K. [Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongkumkoon, P. [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wanichapichart, P. [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Membrane Science and Technology Research Center, Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkla 90112 (Thailand); Anuntalabhochai, S. [Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2013-06-15

    Low-energy ion beams at a few tens of keV were demonstrated to be able to induce exogenous macromolecules to transfer into plant and bacterial cells. In the process, the ion beam with well controlled energy and fluence bombarded living cells to cause certain degree damage in the cell envelope in nanoscales to facilitate the macromolecules such as DNA to pass through the cell envelope and enter the cell. Consequently, the technique was applied for manipulating positive improvements in the biological species. This physical DNA transfer method was highly efficient and had less risk of side-effects compared with chemical and biological methods. For better understanding of mechanisms involved in the process, a systematic study on the mechanisms was carried out. Applications of the technique were also expanded from DNA transfer in plant and bacterial cells to DNA transfection in human cancer cells potentially for the stem cell therapy purpose. Low-energy nitrogen and argon ion beams that were applied in our experiments had ranges of 100 nm or less in the cell envelope membrane which was majorly composed of polymeric cellulose. The ion beam bombardment caused chain-scission dominant damage in the polymer and electrical property changes such as increase in the impedance in the envelope membrane. These nano-modifications of the cell envelope eventually enhanced the permeability of the envelope membrane to favor the DNA transfer. The paper reports details of our research in this direction.

  8. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    Science.gov (United States)

    Xu, Gang; Wang, Xiao-teng; Gan, Cai-ling; Fang, Yan-qiong; Zhang, Meng

    2012-09-01

    To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N+ with energy of 25 keV was applied to treat the dry seed at six different doses. N+ beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 1016 to 15 × 1016 ions cm-2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 1016 ion cm-2, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 1016 ions cm-2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

  9. Physical, biological and clinical basis of light ions using in radiotherapy: EULIMA project

    International Nuclear Information System (INIS)

    Chauvel, P.

    1991-01-01

    Improving the efficiency of radiotherapy is a constant concern in oncology: more than half of the patients who contract cancer receive radiotherapy at some stage. Use of charged particles in radiotherapy represents indisputable progress in localization of the dose delivered to tumour masses, thereby allowing reduction of dose received by adjacent healthy tissues. Protons improve the physical selectivity of the irradiation, i.e. the dose distribution. High-LET (Linear Energy Transfer) radiations produce different biological effects, decreasing the differences in radiosensitivity, and allowing radiation therapy to control radioresistant tumours. Fast neutrons represent the most known of these high-LET particles, but they suffer of a relatively poor physical selectivity. The two approaches (physical selectivity and biological advantages) are joined in by light ions (Carbon, Oxygen, Neon). Highly selective high-LET radiation therapy can be performed for radioresistant tumours without damage to healthy tissues. Preliminary results obtained in Berkeley (USA) demonstrate an improved local control of unresectable, slowly growing tumours, confirming what could be extrapolated from proton and neutrontherapy. Furthermore, radioactive light ion beams can be used to verify the accuracy of treatment planning by checking the range of the particle with a PET camera, and in the future for the treatment itself. In the framework of its programme Europe against Cancer, the Commission of the European Communities participates in the funding of the EULIMA (European Light Ion Medical Accelerator) project feasibility study, aiming to design an hospital-based light ion therapy facility in Europe [fr

  10. Proceedings of the 1st workshop on ion beam applied biology

    International Nuclear Information System (INIS)

    Shikazono, Naoya; Hase, Yoshihiro; Sakamoto, Ayako; Oono, Yutaka; Tanaka, Atsushi

    2003-03-01

    Application of ion beam-irradiation to biology has been undertaken in JAERI. To establish further development of the research by strengthening the industrial, governmental, and academic cooperation, to share the knowledge of the present status of the field with researchers outside JAERI, and to find out future plans, the 1st workshop on ion beam-applied biology was held. The theme of the workshop was on 'Development of breeding techniques using ion beam-irradiation'. This workshop was held by JAERI on November 19, 2002 under the joint auspices of Kanto·Kouetsu branch of Atomic Energy Society of Japan, Breeding Science Society of Japan, and Genetics Society of Japan. One hundred and thirty people participated in the workshop. Highly qualified presentations were given on irradiation techniques, on outcomes of research, and on novel varieties that had been put to practical use, which were the results obtained at the irradiation facilities of JAERI, RIKEN, and WERC. Many new plant resources are expected to be produced by ion beam irradiation, and application of new irradiation techniques, such as microbeams, would be useful in the near future. The 8 of the presented papers are indexed individually. (J.P.N)

  11. Nano-ranged low-energy ion-beam-induced DNA transfer in biological cells

    International Nuclear Information System (INIS)

    Yu, L.D.; Wongkham, W.; Prakrajang, K.; Sangwijit, K.; Inthanon, K.; Thongkumkoon, P.; Wanichapichart, P.; Anuntalabhochai, S.

    2013-01-01

    Low-energy ion beams at a few tens of keV were demonstrated to be able to induce exogenous macromolecules to transfer into plant and bacterial cells. In the process, the ion beam with well controlled energy and fluence bombarded living cells to cause certain degree damage in the cell envelope in nanoscales to facilitate the macromolecules such as DNA to pass through the cell envelope and enter the cell. Consequently, the technique was applied for manipulating positive improvements in the biological species. This physical DNA transfer method was highly efficient and had less risk of side-effects compared with chemical and biological methods. For better understanding of mechanisms involved in the process, a systematic study on the mechanisms was carried out. Applications of the technique were also expanded from DNA transfer in plant and bacterial cells to DNA transfection in human cancer cells potentially for the stem cell therapy purpose. Low-energy nitrogen and argon ion beams that were applied in our experiments had ranges of 100 nm or less in the cell envelope membrane which was majorly composed of polymeric cellulose. The ion beam bombardment caused chain-scission dominant damage in the polymer and electrical property changes such as increase in the impedance in the envelope membrane. These nano-modifications of the cell envelope eventually enhanced the permeability of the envelope membrane to favor the DNA transfer. The paper reports details of our research in this direction.

  12. A model of heavy ion detection in physical and biological systems

    International Nuclear Information System (INIS)

    Waligorski, M.P.R.

    1988-01-01

    Track structure theory (the Katz model) and its application to the detection of heavy ions in physical and biological systems are reviewed. Following the use of a new corrected formula describing the radial distribution of average dose around the path of a heavy ion, based on results of Monte Carlo calculations and on results of experimental measurements, better agreement is achieved between model calculations and experimentally measured relative effectiveness, for enzymatic and viral systems, for the Fricke dosemeter and for alanine and thermoluminescent (TDL-700) dosemeters irradiated with beams of heavy charged particles. From experimentally measured RBE dependences for survival and frequency of neoplastic transformations in a mammalian cell culture irradiated with beams of energetic heavy ions, values of model parameters for these biological endpoints have been extracted, and a model extrapolation to the low-dose region performed. Results of model calculations are then compared with evaluations of the lung cancer hazard in populations exposed to radon and its progeny. The model can be applied to practical phenomenological analysis of radiation damage in solid-state systems and to dosimetry of charged particle and fast neutron beams using a variety of detectors. The model can also serve as a guide in building more basic models of the action of ionizing radiation with physical and biological systems and guide of development of models of radiation risk more relevant than that used presently. 185 refs., 31 figs., 3 tabs. (author)

  13. Impact parameter determination for the passage of cosmic heavy ions through mesoscopic biological test organisms

    International Nuclear Information System (INIS)

    Facius, R.; Reitz, G.; Buecker, H.; Nevzgodina, L.V.; Maximova, E.N.

    1992-01-01

    Seeds of the plant Lactuca sativa as a prototype of a mesoscopic, i.e. neither micro- nor truly macroscopic, biological test organism, were exposed during the Biocosmos 9 mission to cosmic heavy ions within stacks of visual track detectors in order to explore the not yet properly understood radiobiological effects of single heavy ions. In such an investigation, the establishment of the geometrical correlation between the ion trajectories and the location of radiation-sensitive biological substructures is an essential task. We describe how this was achieved for biological test organisms, whose location and orientation had to be derived from contact photographs displaying their outlines and those of the holder plates only. The overall qualitative and quantitative precision achieved, as well as the contributing sources of uncertainties are discussed in detail. A precision of ≅ 10μm was accomplished for the coordinates of particle trajectories, which is near the limit set by the mechanical precision and stability of the detector material. The precision of the impact parameter is limited by the uncertainty in the location of the internal structures, which at best is around 50 and at worst around 150 μm, but is still acceptable when compared with the extension of the sensitive structures. (author)

  14. Impact parameter determination for the passage of cosmic heavy ions through mesoscopic biological test organisms

    Energy Technology Data Exchange (ETDEWEB)

    Facius, R.; Reitz, G.; Buecker, H. (Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Koeln (Germany)); Nevzgodina, L.V.; Maximova, E.N. (Institute of Biomedical Problems, Moscow (USSR))

    1992-01-01

    Seeds of the plant Lactuca sativa as a prototype of a mesoscopic, i.e. neither micro- nor truly macroscopic, biological test organism, were exposed during the Biocosmos 9 mission to cosmic heavy ions within stacks of visual track detectors in order to explore the not yet properly understood radiobiological effects of single heavy ions. In such an investigation, the establishment of the geometrical correlation between the ion trajectories and the location of radiation-sensitive biological substructures is an essential task. We describe how this was achieved for biological test organisms, whose location and orientation had to be derived from contact photographs displaying their outlines and those of the holder plates only. The overall qualitative and quantitative precision achieved, as well as the contributing sources of uncertainties are discussed in detail. A precision of {approx equal} 10{mu}m was accomplished for the coordinates of particle trajectories, which is near the limit set by the mechanical precision and stability of the detector material. The precision of the impact parameter is limited by the uncertainty in the location of the internal structures, which at best is around 50 and at worst around 150 {mu}m, but is still acceptable when compared with the extension of the sensitive structures. (author).

  15. Comparison of Model Calculations of Biological Damage from Exposure to Heavy Ions with Measurements

    Science.gov (United States)

    Kim, Myung-Hee Y.; Hada, Megumi; Cucinotta, Francis A.; Wu, Honglu

    2014-01-01

    The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the major protection to astronauts from harmful exposure. Unlike low-LET gamma or X rays, the presence of shielding does not always reduce the radiation risks for energetic charged-particle exposure. Dose delivered by the charged particle increases sharply at the Bragg peak. However, the Bragg curve does not necessarily represent the biological damage along the particle path since biological effects are influenced by the track structures of both primary and secondary particles. Therefore, the ''biological Bragg curve'' is dependent on the energy and the type of the primary particle and may vary for different biological end points. Measurements of the induction of micronuclei (MN) have made across the Bragg curve in human fibroblasts exposed to energetic silicon and iron ions in vitro at two different energies, 300 MeV/nucleon and 1 GeV/nucleon. Although the data did not reveal an increased yield of MN at the location of the Bragg peak, the increased inhibition of cell progression, which is related to cell death, was found at the Bragg peak location. These results are compared to the calculations of biological damage using a stochastic Monte-Carlo track structure model, Galactic Cosmic Ray Event-based Risk Model (GERM) code (Cucinotta, et al., 2011). The GERM code estimates the basic physical properties along the passage of heavy ions in tissue and shielding materials, by which the experimental set-up can be interpreted. The code can also be used to describe the biophysical events of interest in radiobiology, cancer therapy, and space exploration. The calculation has shown that the severely damaged cells at the Bragg peak are more likely to go through reproductive death, the so called "overkill".

  16. Concentration and purification of plutonium solutions by means of ion-exchange columns

    Energy Technology Data Exchange (ETDEWEB)

    Durham, R W; Aikin, A M

    1953-02-15

    Equilibrium experiments using Dowex 50 ion-exchange resin and nitric acid solutions of Pu{sup 3+}, UO{sub 2}{sup 2+}, Fe{sup 2+} cations have yielded values for the absorption affinities for these ions. Trivalent plutonium was found to be far more strongly absorbed than UO{sub 2}{sup 2+} and Fe{sup 2+}. Column studies have shown that uranium can be completely separated from plutonium even when the initial concentration of uranium is very much greater than that of the plutonium. A plutonium concentration increase of about fifty-fold can be obtained from solutions about 10{sup -3} M in plutonium and 1.0M in nitric acid. The equation K{sub Pu}{sup 3+} = X{sub R} (1-X{sub S}){sup 3} C{sub S}{sup 2}/X{sub S} (1-X{sub R}){sup 3} C{sub R}{sup 2} for estimating the maximum amount of plutonium taken up by a column of resin of unit volume from a solution of total equivalent concentration, C{sub S} , has been shown to hold for values of C{sub S} up to 3 equivalents per litre. X{sub R}, the equivalent fraction of plutonium on the resin, is the number of equivalents of plutonium absorbed by the resin divided by the total capacity of the column. X{sub S}, the equivalent fraction of plutonium in solution, is the equivalent concentration of plutonium divided by the total equivalent concentration of cations in solution. C{sub R} is the total capacity of the resin in milli-equivalents per gram of dry resin. Recommendations have been made for the application and operation of ion-exchange columns in the Plutonium-Extraction Plant. (author)

  17. Biological Effects of Osteoblast-Like Cells on Nanohydroxyapatite Particles at a Low Concentration Range

    Directory of Open Access Journals (Sweden)

    Xiaochen Liu

    2011-01-01

    Full Text Available The biological effects of osteoblast-like MG-63 cells on nanohydroxyapatite (n-HA at the low concentration range (5–25 g/mL for 5 days was investigated. The results showed the viability and actin cytoskeleton of the cells descended with the increase of the concentration of n-HA, and the actin cytoskeleton of cells was depolymerised and became more disordered. Apoptotic rate of cells (1.85%, 1.99%, and 2.29% increased with the increase of n-HA concentration (5, 15, and 25 g/mL and become significantly higher than the control. Total intracellular protein content decreased with n-HA concentration increase, showing significant difference between 25 g/mL and the control, and no significant change of ALP activity was observed at the 5th day. The results revealed that the cell growth was inhibited by n-HA in a concentration-dependent manner, and the obvious biological effects of MG-63 cells on n-HA existed at the low concentration range from 5 to 25 g/mL.

  18. Uncovering biologically significant lipid isomers with liquid chromatography, ion mobility spectrometry and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kyle, Jennifer E.; Zhang, Xing; Weitz, Karl K.; Monroe, Matthew E.; Ibrahim, Yehia M.; Moore, Ronald J.; Cha, Jeeyeon; Sun, Xiaofei; Lovelace, Erica S.; Wagoner, Jessica; Polyak, Steve; Metz, Thomas O.; Dey, Sudhansu K.; Smith, Richard D.; Burnum-Johnson, Kristin E.; Baker, Erin Shammel

    2016-01-01

    Understanding how biological molecules are generated, metabolized and eliminated in living systems is important for interpreting processes such as immune response and disease pathology. While genomic and proteomic studies have provided vast amounts of information over the last several decades, interest in lipidomics has also grown due to improved analytical technologies revealing altered lipid metabolism in type 2 diabetes, cancer, and lipid storage disease. Liquid chromatography and mass spectrometry (LC-MS) measurements are currently the dominant approach for characterizing the lipidome by providing detailed information on the spatial and temporal composition of lipids. However, interpreting lipids’ biological roles is challenging due to the existence of numerous structural and stereoisomers (i.e. distinct acyl chain and double-bond positions), which are unresolvable using present LC-MS approaches. Here we show that combining structurally-based ion mobility spectrometry (IMS) with LC-MS measurements distinguishes lipid isomers and allows insight into biological and disease processes.

  19. Helium Ion Microscopy (HIM) for the imaging of biological samples at sub-nanometer resolution

    Science.gov (United States)

    Joens, Matthew S.; Huynh, Chuong; Kasuboski, James M.; Ferranti, David; Sigal, Yury J.; Zeitvogel, Fabian; Obst, Martin; Burkhardt, Claus J.; Curran, Kevin P.; Chalasani, Sreekanth H.; Stern, Lewis A.; Goetze, Bernhard; Fitzpatrick, James A. J.

    2013-12-01

    Scanning Electron Microscopy (SEM) has long been the standard in imaging the sub-micrometer surface ultrastructure of both hard and soft materials. In the case of biological samples, it has provided great insights into their physical architecture. However, three of the fundamental challenges in the SEM imaging of soft materials are that of limited imaging resolution at high magnification, charging caused by the insulating properties of most biological samples and the loss of subtle surface features by heavy metal coating. These challenges have recently been overcome with the development of the Helium Ion Microscope (HIM), which boasts advances in charge reduction, minimized sample damage, high surface contrast without the need for metal coating, increased depth of field, and 5 angstrom imaging resolution. We demonstrate the advantages of HIM for imaging biological surfaces as well as compare and contrast the effects of sample preparation techniques and their consequences on sub-nanometer ultrastructure.

  20. Measurement of diffusion coefficient of thallium ion in H2O and D2O systems at different concentrations

    International Nuclear Information System (INIS)

    Das, A.; Changdar, S.N.

    1992-01-01

    Sliding cell method, developed in our laboratory, has been used to measure the inter diffusion coefficient of thallium ion in thallous sulphate solution over a wide concentration range using both water and heavy water as solvent at 35degC. The results have been analysed from the point of view of both ion-ion and ion-solvent interactions. The comparison of the diffusivities of the same ion in D 2 O and H 2 O electrolyte solutions at the same temperature indicate that the addition of salt affects the two solvent differently. (author). 8 refs., 1 fig., 1 tab

  1. A Novel Passive Wireless Sensing Method for Concrete Chloride Ion Concentration Monitoring

    Directory of Open Access Journals (Sweden)

    Shuangxi Zhou

    2017-12-01

    Full Text Available In this paper, a novel approach for concrete chloride ion concentration measuring based on passive and wireless sensor tag is proposed. The chloride ion sensor based on RFID communication protocol is consisting of an energy harvesting and management circuit, a low dropout voltage regulator, a MCU, a RFID tag chip and a pair of electrodes. The proposed sensor harvests energy radiated by the RFID reader to power its circuitry. To improve the stability of power supply, a three-stage boost rectifier is customized to rectify the harvested power into dc power and step-up the voltage. Since the measured data is wirelessly transmitted, it contains miscellaneous noises which would decrease the accuracy of measuring. Thus, in this paper, the wavelet denoising method is adopted to denoise the raw data. Besides, a monitoring software is developed to display the measurement results in real-time. The measurement results indicate that the proposed passive sensor tag can achieve a reliable communication distance of 16.3 m and can reliably measure the chloride ion concentration in concrete.

  2. A Novel Passive Wireless Sensing Method for Concrete Chloride Ion Concentration Monitoring.

    Science.gov (United States)

    Zhou, Shuangxi; Sheng, Wei; Deng, Fangming; Wu, Xiang; Fu, Zhihui

    2017-12-11

    In this paper, a novel approach for concrete chloride ion concentration measuring based on passive and wireless sensor tag is proposed. The chloride ion sensor based on RFID communication protocol is consisting of an energy harvesting and management circuit, a low dropout voltage regulator, a MCU, a RFID tag chip and a pair of electrodes. The proposed sensor harvests energy radiated by the RFID reader to power its circuitry. To improve the stability of power supply, a three-stage boost rectifier is customized to rectify the harvested power into dc power and step-up the voltage. Since the measured data is wirelessly transmitted, it contains miscellaneous noises which would decrease the accuracy of measuring. Thus, in this paper, the wavelet denoising method is adopted to denoise the raw data. Besides, a monitoring software is developed to display the measurement results in real-time. The measurement results indicate that the proposed passive sensor tag can achieve a reliable communication distance of 16.3 m and can reliably measure the chloride ion concentration in concrete.

  3. Proceedings of the 3rd workshop on ion-beam-applied biology

    International Nuclear Information System (INIS)

    Matsuhashi, Shinpei; Suzui, Nobuo; Ishioka, Noriko S.

    2005-09-01

    In order to encourage research on biological application using ion beam at TIARA, we have had the workshop on ion beam applied biology at JAERI Takasaki every year since 2002. The 3rd workshop titled 'Future development of plant research using the positron imaging method - Understanding the plant functions through visualization images-' is held this year. The main topics of this workshop are introduction of the latest studies on the assimilation and transportation of nutrients by plant using positron imaging method. Further, related technologies of the positron imaging and prospect of positron imaging for is discussed. We hope this workshop popularizes positron imaging technology for plants, accelerates cooperation between industries, universities and governmental institutes and contributes future projects of understanding of the physiological functions of plants using the positron imaging method. This workshop was held on September 29th 2004, hosted by JAERI Takasaki and cooperated by The Japan Radioisotope Association, Japanese Society of Soil Science and Plant Nutrition. The Japanese Society of Plant Physiologists, Atomic Energy Society of Japan, The Japanese Society of Nuclear and Radiochemical Science and The Ion Beam Breeding Society. There were 85 participants from not only universities and laboratories but also private company developing the environment conservation technology, so on. Highly qualified presentations were given on biological studies with ion beam, on analysis of plant functions using the positron imaging method and on supporting technology for the positron imaging monitoring. Progress in the elucidation of plant functions is expected to develop the technologies for production of safe provisions and conservation of environment with plant. The 14 of the presented papers are indexed individually. (J.P.N.)

  4. The impact of loading approach and biological activity on NOM removal by ion exchange resins.

    Science.gov (United States)

    Winter, Joerg; Wray, Heather E; Schulz, Martin; Vortisch, Roman; Barbeau, Benoit; Bérubé, Pierre R

    2018-05-01

    The present study investigated the impact of different loading approaches and microbial activity on the Natural Organic Matter (NOM) removal efficiency and capacity of ion exchange resins. Gaining further knowledge on the impact of loading approaches is of relevance because laboratory-scale multiple loading tests (MLTs) have been introduced as a simpler and faster alternative to column tests for predicting the performance of IEX, but only anecdotal evidence exists to support their ability to forecast contaminant removal and runtime until breakthrough of IEX systems. The overall trends observed for the removal and the time to breakthrough of organic material estimated using MLTs differed from those estimated using column tests. The results nonetheless suggest that MLTs could best be used as an effective tool to screen different ion exchange resins in terms of their ability to remove various contaminants of interest from different raw waters. The microbial activity was also observed to impact the removal and time to breakthrough. In the absence of regeneration, a microbial community rapidly established itself in ion exchange columns and contributed to the removal of organic material. Biological ion exchange (BIEX) removed more organic material and enabled operation beyond the point when the resin capacity would have otherwise been exhausted using conventional (i.e. in the absence of a microbial community) ion exchange. Furthermore, significantly greater removal of organic matter could be achieved with BIEX than biological activated carbon (BAC) (i.e. 56 ± 7% vs. 15 ± 5%, respectively) when operated at similar loading rates. The results suggest that for some raw waters, BIEX could replace BAC as the technology of choice for the removal of organic material. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Helium ions for radiotherapy? Physical and biological verifications of a novel treatment modality

    Energy Technology Data Exchange (ETDEWEB)

    Krämer, Michael, E-mail: m.kraemer@gsi.de; Scifoni, Emanuele; Schuy, Christoph; Rovituso, Marta; Maier, Andreas; Kaderka, Robert; Kraft-Weyrather, Wilma [Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany); Tinganelli, Walter; Durante, Marco [Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany and Trento Institute for Fundamental Physics and Application (TIFPA-INFN), 38123, via Sommarive 14, Trento (Italy); Brons, Stephan; Tessonnier, Thomas [Heidelberger Ionenstrahl-Therapiezentrum (HIT), Im Neuenheimer Feld 450, 69120 Heidelberg, Germany and Radioonkologie und Strahlentherapie, Universitätsklinikums Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg (Germany); Parodi, Katia [Heidelberger Ionenstrahl-Therapiezentrum (HIT), Im Neuenheimer Feld 450, 69120 Heidelberg (Germany); Radioonkologie und Strahlentherapie, Universitätsklinikums Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg (Germany); Ludwig-Maximilians-Universitaet Muenchen (LMU Munich), Department of Medical Physics, Am Coulombwall 1, 85748 Munich (Germany)

    2016-04-15

    Purpose: Modern facilities for actively scanned ion beam radiotherapy allow in principle the use of helium beams, which could present specific advantages, especially for pediatric tumors. In order to assess the potential use of these beams for radiotherapy, i.e., to create realistic treatment plans, the authors set up a dedicated {sup 4}He beam model, providing base data for their treatment planning system TRiP98, and they have reported that in this work together with its physical and biological validations. Methods: A semiempirical beam model for the physical depth dose deposition and the production of nuclear fragments was developed and introduced in TRiP98. For the biological effect calculations the last version of the local effect model was used. The model predictions were experimentally verified at the HIT facility. The primary beam attenuation and the characteristics of secondary charged particles at various depth in water were investigated using {sup 4}He ion beams of 200 MeV/u. The nuclear charge of secondary fragments was identified using a ΔE/E telescope. 3D absorbed dose distributions were measured with pin point ionization chambers and the biological dosimetry experiments were realized irradiating a Chinese hamster ovary cells stack arranged in an extended target. Results: The few experimental data available on basic physical processes are reproduced by their beam model. The experimental verification of absorbed dose distributions in extended target volumes yields an overall agreement, with a slight underestimation of the lateral spread. Cell survival along a 4 cm extended target is reproduced with remarkable accuracy. Conclusions: The authors presented a simple simulation model for therapeutical {sup 4}He beams which they introduced in TRiP98, and which is validated experimentally by means of physical and biological dosimetries. Thus, it is now possible to perform detailed treatment planning studies with {sup 4}He beams, either exclusively or in

  6. Biological treatment of concentrated hazardous, toxic, and radionuclide mixed wastes without dilution

    International Nuclear Information System (INIS)

    Stringfellow, William T.; Komada, Tatsuyuki; Chang, Li-Yang

    2004-01-01

    Approximately 10 percent of all radioactive wastes produced in the U. S. are mixed with hazardous or toxic chemicals and therefore can not be placed in secure land disposal facilities. Mixed wastes containing hazardous organic chemicals are often incinerated, but volatile radioactive elements are released directly into the biosphere. Some mixed wastes do not currently have any identified disposal option and are stored locally awaiting new developments. Biological treatment has been proposed as a potentially safer alternative to incineration for the treatment of hazardous organic mixed wastes, since biological treatment would not release volatile radioisotopes and the residual low-level radioactive waste would no longer be restricted from land disposal. Prior studies have shown that toxicity associated with acetonitrile is a significant limiting factor for the application of biotreatment to mixed wastes and excessive dilution was required to avoid inhibition of biological treatment. In this study, we demonstrate that a novel reactor configuration, where the concentrated toxic waste is drip-fed into a complete-mix bioreactor containing a pre-concentrated active microbial population, can be used to treat a surrogate acetonitrile mixed waste stream without excessive dilution. Using a drip-feed bioreactor, we were able to treat a 90,000 mg/L acetonitrile solution to less than 0.1 mg/L final concentration using a dilution factor of only 3.4. It was determined that the acetonitrile degradation reaction was inhibited at a pH above 7.2 and that the reactor could be modeled using conventional kinetic and mass balance approaches. Using a drip-feed reactor configuration addresses a major limiting factor (toxic inhibition) for the biological treatment of toxic, hazardous, or radioactive mixed wastes and suggests that drip-feed bioreactors could be used to treat other concentrated toxic waste streams, such as chemical warfare materiel

  7. Biological treatment of concentrated hazardous, toxic, andradionuclide mixed wastes without dilution

    Energy Technology Data Exchange (ETDEWEB)

    Stringfellow, William T.; Komada, Tatsuyuki; Chang, Li-Yang

    2004-06-15

    Approximately 10 percent of all radioactive wastes produced in the U. S. are mixed with hazardous or toxic chemicals and therefore can not be placed in secure land disposal facilities. Mixed wastes containing hazardous organic chemicals are often incinerated, but volatile radioactive elements are released directly into the biosphere. Some mixed wastes do not currently have any identified disposal option and are stored locally awaiting new developments. Biological treatment has been proposed as a potentially safer alternative to incineration for the treatment of hazardous organic mixed wastes, since biological treatment would not release volatile radioisotopes and the residual low-level radioactive waste would no longer be restricted from land disposal. Prior studies have shown that toxicity associated with acetonitrile is a significant limiting factor for the application of biotreatment to mixed wastes and excessive dilution was required to avoid inhibition of biological treatment. In this study, we demonstrate that a novel reactor configuration, where the concentrated toxic waste is drip-fed into a complete-mix bioreactor containing a pre-concentrated active microbial population, can be used to treat a surrogate acetonitrile mixed waste stream without excessive dilution. Using a drip-feed bioreactor, we were able to treat a 90,000 mg/L acetonitrile solution to less than 0.1 mg/L final concentration using a dilution factor of only 3.4. It was determined that the acetonitrile degradation reaction was inhibited at a pH above 7.2 and that the reactor could be modeled using conventional kinetic and mass balance approaches. Using a drip-feed reactor configuration addresses a major limiting factor (toxic inhibition) for the biological treatment of toxic, hazardous, or radioactive mixed wastes and suggests that drip-feed bioreactors could be used to treat other concentrated toxic waste streams, such as chemical warfare materiel.

  8. Concentration effect on the spectroscopic behavior of Tb{sup 3+} ions in zinc phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kesavulu, C.R., E-mail: crkesavulu2005@gmail.com [Instituto de Fisica de São Carlos, Universidade de São Paulo, Avenida Trabalhador Sãocarlense 400, São Carlos, SP (Brazil); Almeida Silva, Anielle Christine [Laboratorio de Novos Materials Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberândia, MG (Brazil); Dousti, M.R. [Instituto de Fisica de São Carlos, Universidade de São Paulo, Avenida Trabalhador Sãocarlense 400, São Carlos, SP (Brazil); Dantas, Noelio Oliveira [Laboratorio de Novos Materials Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberândia, MG (Brazil); Camargo, A.S.S. de; Catunda, Tomaz [Instituto de Fisica de São Carlos, Universidade de São Paulo, Avenida Trabalhador Sãocarlense 400, São Carlos, SP (Brazil)

    2015-09-15

    Zinc phosphate glasses (PZABPTb) in the compositional system: P{sub 2}O{sub 5}–ZnO–Al{sub 2}O{sub 3}–BaO–PbO doped with variable Tb{sup 3+} concentrations (1–5 wt% Tb{sub 2}O{sub 3}) were prepared and characterized through absorption, excitation, emission and intensity decay rate measurements. The Judd–Ofelt model has been adopted to evaluate the radiative properties of the {sup 5}D{sub 4}→{sup 7}F{sub 6–3} emission transitions. The effect of Tb{sup 3+} ion concentration on the emissions from the {sup 5}D{sub 3,4} excited levels is discussed in detail. Analysis of the intensity decay curves corresponding to blue and green emissions from levels {sup 5}D{sub 3} and {sup 5}D{sub 4}, respectively, allowed determination of effective lifetimes, which confirmed the Tb{sup 3+} ion concentration quenching of the blue emission in these glasses. The decay curves for the {sup 5}D{sub 3} level are found to be non-exponential in nature for all the studied concentrations due to ion–ion energy transfer through cross-relaxation. In an attempt to identify the origin of the energy transfer mechanism, the decay curves were well fitted to the Inokuti–Hirayama model for S=6, which indicates that the energy transfer process is of dipole–dipole type. The optical band gap energy (E{sub opt}) has been evaluated taking into account the ultraviolet edge of absorption spectra. - Highlights: • Tb{sup 3+}-doped zinc phosphate glasses have been prepared by melt quenching technique. • Spectroscopic parameters were evaluated using the Judd–Ofelt theory. • Effects of Tb{sup 3+} concentration on luminescence of the glasses were studied. • Strong intense laser transition for Tb{sup 3+} ion in PZABPTb glasses is {sup 5}D{sub 4}→{sup 7}F{sub 5} (0.54 μm). • PZABPTb glasses could be used in the development of green color display devices and solid state visible lasers.

  9. Highly sensitive colour change system within slight differences in metal ion concentrations based on homo-binuclear complex formation equilibrium for visual threshold detection of trace metal ions

    International Nuclear Information System (INIS)

    Mizuguchi, Hitoshi; Atsumi, Hiroshi; Hashimoto, Keigo; Shimada, Yasuhiro; Kudo, Yuki; Endo, Masatoshi; Yokota, Fumihiko; Shida, Junichi; Yotsuyanagi, Takao

    2004-01-01

    A new technique of expressing slight differences in metal ion concentrations by clear difference in colour was established for visual threshold detection of trace metal ions. The proposed method is based on rapid change of the mole fraction of the homo-binuclear complex (M 2 L) about a ligand in a narrow range of the total metal ion concentration (M T ) in a small excess, in case the second metal ion is bound to the reagent molecule which can bind two metal ions. Theoretical simulations showed that the highly sensitive colour change within slight differences in metal ion concentrations would be realized under the following conditions: (i) both of the stepwise formation constants of complex species are sufficiently large; (ii) the stepwise formation constant of the 1:1 complex (ML) is larger than that of M 2 L; and (iii) the absorption spectrum of M 2 L is far apart from the other species in the visible region. Furthermore, the boundary of the colour region in M T would be readily controlled by the total ligand concentration (L T ). Based on this theory, the proposed model was verified with the 3,3'-bis[bis(carboxymethyl)amino]methyl derivatives of sulphonephthalein dyes such as xylenol orange (XO), methylthymol blue (MTB), and methylxylenol blue (MXB), which can bind two metal ions at both ends of a π-electron conjugated system. The above-mentioned model was proved with the iron(III)-XO system at pH 2. In addition, MTB and MXB were suitable reagents for the visual threshold detection of trivalent metal ions such as iron(III), aluminium(III), gallium(III) and indium(III) ion in slightly acidic media. The proposed method has been applied successfully as a screening test for aluminium(III) ion in river water sampled at the downstream area of an old mine

  10. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    Energy Technology Data Exchange (ETDEWEB)

    Xu Gang, E-mail: xg335300@yahoo.com.cn [Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang 550025 (China); Institute of Entomology, Guizhou University, Guiyang 550025 (China); Wang Xiaoteng [Department of Agricultural Resources and Environment, College of Agricultural, Guizhou University, Guiyang 550025 (China); Gan Cailing; Fang Yanqiong; Zhang Meng [College of Life Sciences, Guizhou University, Guiyang 550025 (China)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We analyzed biological effects of N{sup +} implantation on dry Jatropha curcas seed. Black-Right-Pointing-Pointer N{sup +} implantation greatly decreased seedling survival rate. Black-Right-Pointing-Pointer At doses beyond 15 Multiplication-Sign 10{sup 16} ion cm{sup -2}, biological repair took place. Black-Right-Pointing-Pointer CAT was essential for H{sub 2}O{sub 2} removal. POD mainly functioned as seed was severely hurt. Black-Right-Pointing-Pointer HAsA-GSH cycle mainly contributed to the regeneration of HAsA. - Abstract: To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N{sup +} with energy of 25 keV was applied to treat the dry seed at six different doses. N{sup +} beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 Multiplication-Sign 10{sup 16} to 15 Multiplication-Sign 10{sup 16} ions cm{sup -2} severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 Multiplication-Sign 10{sup 16} ion cm{sup -2}, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 Multiplication-Sign 10{sup 16} ions cm{sup -2} may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

  11. Effect of oxide ion concentration on the electrochemical oxidation of carbon in molten LiCl

    International Nuclear Information System (INIS)

    Yun, J. W.; Choi, I. K.; Park, Y. S.; Kim, W. H.

    2001-01-01

    The continuous measurement of lithium oxide concentration was required in DOR (Direct Oxide Reduction) process, which converts spent nuclear fuel to metal form, for the reactivity monitor and effective control of the process. The concentration of lithium oxide was measured by the electrochemical method, which was based on the phenomenon that carbon atoms of glassy carbon electrode electrochemically react with oxygen ions of lithium oxide in molten LiCl medium. From the results of electrode polarization experiments, the trend of oxidation rate of carbon atoms was classified into two different regions, which were proportional and non-proportional ones, dependent on the amount of lithium oxide. Below about 2.5 wt % Li 2 O, as the carbon atom ionization rate was fast enough for reacting with diffusing lithium oxide to the surface of carbon electrode. In this concentration range, the oxidation rate of carbon atoms was controlled by the diffusion of lithium oxide, and the concentration of lithium oxide could be measured by electrochemical method. But, above 2.5 wt % Li 2 O, the oxidation rate of carbon atoms was controlled by the applied electrochemical potential, because the carbon atom ionization rate was suppressed by the huge amounts of diffusing Li 2 O. Above this concentration, the electrochemical method was not applicable to determine the concentration of lithium oxide

  12. Scanning transmission ion micro-tomography (STIM-T) of biological specimens

    International Nuclear Information System (INIS)

    Schwertner, Michael; Sakellariou, Arthur; Reinert, Tilo; Butz, Tilman

    2006-01-01

    Computed tomography (CT) was applied to sets of Scanning Transmission Ion Microscopy (STIM) projections recorded at the LIPSION ion beam laboratory (Leipzig) in order to visualize the 3D-mass distribution in several specimens. Examples for a test structure (copper grid) and for biological specimens (cartilage cells, cygospore) are shown. Scanning Transmission Micro-Tomography (STIM-T) at a resolution of 260 nm was demonstrated for the first time. Sub-micron features of the Cu-grid specimen were verified by scanning electron microscopy. The ion energy loss measured during a STIM-T experiment is related to the mass density of the specimen. Typically, biological specimens can be analysed without staining. Only shock freezing and freeze-drying is required to preserve the ultra-structure of the specimen. The radiation damage to the specimen during the experiment can be neglected. This is an advantage compared to other techniques like X-ray micro-tomography. At present, the spatial resolution is limited by beam position fluctuations and specimen vibrations

  13. Heavy-ion radiobiology: new approaches to delineate mechanisms underlying enhanced biological effectiveness

    Science.gov (United States)

    Blakely, E. A.; Kronenberg, A.; Chatterjee, A. (Principal Investigator)

    1998-01-01

    Shortly after the discovery of polonium and radium by Marie Curie and her husband and colleague, Pierre Curie, it was learned that exposure to these alpha-particle emitters produced deleterious biological effects. The mechanisms underlying the increased biological effectiveness of densely ionizing radiations, including alpha particles, neutrons and highly energetic heavy charged particles, remain an active area of investigation. In this paper, we review recent advances in several areas of the radiobiology of these densely ionizing radiations, also known as heavy ions. Advances are described in the areas of DNA damage and repair, chromosome aberrations, mutagenesis, neoplastic transformation in vitro, genomic instability, normal tissue radiobiology and carcinogenesis in vivo. We focus on technical innovations, including novel applications of pulsed-field gel electrophoresis, fluorescence in situ hybridization (FISH), linkage analysis, and studies of gene expression and protein expression. We also highlight the use of new cellular and animal systems, including those with defined DNA repair deficiencies, as well as epithelial cell model systems to assess neoplastic transformation both in vitro and in vivo. The studies reviewed herein have had a substantial impact on our understanding of the genotoxic effects of heavy ions as well as their distinct effects on tissue homeostasis. The use of these radiations in cancer therapy is also discussed. The use of both heavy-ion and proton therapy is on the upswing in several centers around the world, due to their unique energy deposition characteristics that enhance the therapeutic effect and help reduce damage to normal tissue.

  14. Cystatin C and lactoferrin concentrations in biological fluids as possible prognostic factors in eye tumor development

    Directory of Open Access Journals (Sweden)

    Mariya A. Dikovskaya

    2013-08-01

    Full Text Available Objectives. To investigate the possible role of cystatin C in eye biological fluids locally and in serum and lactoferrin revealing anti-tumor activity in eye tumor development. Background. The increased number of eye tumors was registered recently not only in the countries with high insolation, but also in the northern countries including Russia (11 cases per million of population. Search for new biological markers is important for diagnosis and prognosis in eye tumors. Cystatin C, an endogenous inhibitor of cysteine proteases, plays an important protective role in several tumors. Lactoferrin was shown to express anti-tumor and antiviral activities. It was hypothesized that cystatin C and lactoferrin could serve as possible biomarkers in the diagnosis of malignant and benign eye tumors. Study design. A total of 54 patients with choroidal melanoma and benign eye tumors were examined (part of them undergoing surgical treatment. Serum, tear fluid and intraocular fluid samples obtained from the anterior chamber of eyes in patients with choroidal melanoma were studied. Methods. Cystatin C concentration in serum and eye biological fluids was measured by commercial ELISA kits for human (BioVendor, Czechia; lactoferrin concentration – by Lactoferrin-strip D 4106 ELISA test systems (Vector-BEST, Novosibirsk Region, Russia. Results. Cystatin C concentration in serum of healthy persons was significantly higher as compared to tear and intraocular fluids. In patients with choroidal melanoma, increased cystatin C concentration was similar in tear fluid of both the eyes. Lactoferrin level in tear fluid of healthy persons was significantly higher than its serum level. Significantly increased lactoferrin concentration in tear fluid was noted in patients with benign and malignant eye tumors. Conclusion. Increased level of cystatin C in tear fluid seems to be a possible diagnostic factor in the eye tumors studied. However, it does not allow us to differentiate

  15. Biological and medical research with accelerated heavy ions at the Bevalac, 1974--1977

    International Nuclear Information System (INIS)

    Elam, S.

    1977-04-01

    The Bevalac, a versatile high-energy heavy-ion accelerator complex, has been in operation for less than two years. A major purpose for which the Bevalac was constructed was to explore the possibility of heavy-ion teams for therapy for certain forms of cancer. Significant progress has been made in this direction. The National Cancer Institute has recognized the advantages that these and other accelerated particles offer, and heavy ions have been included in a long-term plan for particle therapy that will assess by means of controlled therapeutic tests the value of various modalities. Since accelerated heavy ions became available, the possibility of other contributions, not planned, became apparent. We are developig a new diagnostic method known as heavy-ion radiography that has greatly increased sensitivity for soft-tissue detail and that may become a powerful tool for localizing early tumors and metastases. We have discovered that radioactive beams are formed from fragmentation of stable deflected beams. Use of these autoradioactive beams is just beginning; however, we know that these beams will be helpful in localizing the region in the body where therapy is being delivered. In addition, it has been demonstrated that instant implantation of the radioactive beam allows direct measurements of blood perfusion rates in inaccessible parts of the body, and such a technique may become a new tool for the study of fast hot atom reactions in biochemistry, tracer biology and nuclear medicine. The Bevalac will also be useful for the continuation of previously developed methods for the control of acromegaly, Cushing's disease and, on a research basis, advanced diabetes mellitus with vascular disease. The ability to make small bloodless lesions in the brain and elsewhere with heavy-ion beams has great potential for nervous-system studies and perhaps later for radioneurosurgery

  16. High mass accuracy and high mass resolving power FT-ICR secondary ion mass spectrometry for biological tissue imaging

    NARCIS (Netherlands)

    Smith, D.F.; Kiss, A.; Leach, F.E.; Robinson, E.W.; Paša-Tolić, L.; Heeren, R.M.A.

    2013-01-01

    Biological tissue imaging by secondary ion mass spectrometry has seen rapid development with the commercial availability of polyatomic primary ion sources. Endogenous lipids and other small bio-molecules can now be routinely mapped on the sub-micrometer scale. Such experiments are typically

  17. A Method for Selective Depletion of Zn(II) Ions from Complex Biological Media and Evaluation of Cellular Consequences of Zn(II) Deficiency

    Science.gov (United States)

    Richardson, Christopher E. R.; Cunden, Lisa S.; Butty, Vincent L.; Nolan, Elizabeth M.; Lippard, Stephen J.; Shoulders, Matthew D.

    2018-01-01

    We describe the preparation, evaluation, and application of an S100A12 protein-conjugated solid support, hereafter the “A12-resin,” that can remove 99% of Zn(II) from complex biological solutions without significantly perturbing the concentrations of other metal ions. The A12-resin can be applied to selectively deplete Zn(II) from diverse tissue culture media and from other biological fluids, including human serum. To further demonstrate the utility of this approach, we investigated metabolic, transcriptomic, and metallomic responses of HEK293 cells cultured in medium depleted of Zn(II) using S100A12. The resulting data provide insight into how cells respond to acute Zn(II) deficiency. We expect that the A12-resin will facilitate interrogation of disrupted Zn(II) homeostasis in biological settings, uncovering novel roles for Zn(II) in biology. PMID:29334734

  18. Studies on biological effects of nitrogen ion implantation in different genotype rice

    International Nuclear Information System (INIS)

    Xie Jiahua; Xia Yingwu; Shu Qingyao

    1994-01-01

    The biological effects of nitrogen ion implantation on different genotype rice (Oryza sativa L) were studied. The results showed that there were obvious differences in physiological damages for the M 1 generation, mutation frequencies and mutagenic efficiencies of chlorophyll, heading date and plant height for M 2 generation of different genotypes. Treated by nitrogen ions, the varieties with high mutation frequency and mutagenic efficiency of chlorophyll in the M 2 generation were not necessarily high in those of heading date and plant height. Moreover, the radiation sensitivity of Fu8530 and Fuxian No.6 which were bred by using early maturing and semidwarf mutants as maternal plant was low. The early maturing and high stature mutation were not induced with these two varieties

  19. Distorted wave calculations for electron loss process induced by bare ion impact on biological targets

    International Nuclear Information System (INIS)

    Monti, J.M.; Tachino, C.A.; Hanssen, J.; Fojón, O.A.; Galassi, M.E.; Champion, C.; Rivarola, R.D.

    2014-01-01

    Distorted wave models are employed to investigate the electron loss process induced by bare ions on biological targets. The two main reactions which contribute to this process, namely, the single electron ionization as well as the single electron capture are here studied. In order to further assess the validity of the theoretical descriptions used, the influence of particular mechanisms are studied, like dynamic screening for the case of electron ionization and energy deposition on the target by the impacting projectile for the electron capture one. Results are compared with existing experimental data. - Highlights: ► Distorted wave models are used to investigate ion-molecule collisions. ► Differential and total cross-sections for capture and ionization are evaluated. ► The influence of dynamic screening is determined. ► Capture reaction dominates the mean energy deposited by the projectile on the target

  20. The Gellyfish: an in-situ equilibrium-based sampler for determining multiple free metal ion concentrations in marine ecosystems

    Science.gov (United States)

    Free metal ions are usually the most bioavailable and toxic metal species to aquatic organisms, but they are difficult to measure because of their extremely low concentrations in the marine environment. Many of the current methods for determining free metal ions are complicated a...

  1. Major Ion Concentrations in WDC05Q and WDC06A Ice Cores (WAIS Divide), Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains major ion concentrations from the chemical analysis of two WAIS Divide ice cores (WDC05Q, 0-114 m; WDC06A, 0-129 m). The analytical technique...

  2. Determination of the total concentration and speciation of metal ions in river, estuarine and seawater samples.

    Science.gov (United States)

    Alberti, Giancarla; Biesuz, Raffaela; Pesavento, Maria

    2008-12-01

    Different natural water samples were investigated to determine the total concentration and the distribution of species for Cu(II), Pb(II), Al(III) and U(VI). The proposed method, named resin titration (RT), was developed in our laboratory to investigate the distribution of species for metal ions in complex matrices. It is a competition method, in which a complexing resin competes with natural ligands present in the sample to combine with the metal ions. In the present paper, river, estuarine and seawater samples, collected during a cruise in Adriatic Sea, were investigated. For each sample, two RTs were performed, using different complexing resins: the iminodiacetic Chelex 100 and the carboxylic Amberlite CG50. In this way, it was possible to detect different class of ligands. Satisfactory results have been obtained and are commented on critically. They were summarized by principal component analysis (PCA) and the correlations with physicochemical parameters allowed one to follow the evolution of the metals along the considered transect. It should be pointed out that, according to our findings, the ligands responsible for metal ions complexation are not the major components of the water system, since they form considerably weaker complexes.

  3. [Effect of different oxygen concentrations on biological properties of bone marrow hematopoietic stem cells of mice].

    Science.gov (United States)

    Ma, Yi-Ran; Ren, Si-Hua; He, Yu-Xin; Wang, Lin-Lin; Jin, Li; Hao, Yi-Wen

    2012-10-01

    This study purposed to investigate the effects of different oxygen concentrations and reactive oxygen species (ROS) on the biological characteristics of hematopoietic stem cells (HSC) and their possible mechanisms through simulating oxygen environment to which the peripheral blood HSC are subjected in peripheral blood HSCT. The proliferation ability, cell cycle, directed differentiation ability, ROS level and hematopoietic reconstitution ability of Lin(-)c-kit(+)Sca-1(+) BMHSC were detected by using in vitro amplification test, directional differentiation test, cell cycle analysis, ROS assay and transplantation of Lin(-)c-kit(+)Sca-1(+) HSC from sublethally irradiated mice respectively. The results showed that oxygen concentrations lower than normal oxygen concentration, especially in hypoxic oxygen environment, could reduce ROS generation and amplify more primitive CD34(+)AC133(+) HSC and active CD34(+) HSC, and maintain more stem cells in the G(0)/G(1) phase, which is more helpful to the growth of CFU-S and viability of mice. At the same time, BMHSC exposed to normal oxygen level or inconstant and greatly changed oxygen concentrations could produce a high level of ROS, and the above-mentioned features and functional indicators are relatively low. It is concluded that ROS levels of HSC in BMHSCT are closely related with the oxygen concentration surrounding the cells and its stability. Low oxygen concentration and antioxidant intervention are helpful to transplantation of BMHSC.

  4. preparation of beryllia n concentrate from beryllium minerals by ion exchange method

    International Nuclear Information System (INIS)

    Shoukry, M.M.; Atrees, M. Sh.; Hashem, M.D.

    2007-01-01

    The present work is concerned with the preparation of pure Beryllia concentrate from Zabara beryl mineralization in the mica schist of Wadi El Gemal area in the eastern desert. This has been possible through application of ion exchange techniques to selectively concentrate. This method is based on the fact that the beryllium complex of ethylene diamine tetra acetic acid (EDTA) at a ph of about 3.5, is much weaker than the corresponding complexes of iron and aluminum. It was, therefore, possible to effect a complete separation of beryllium from the latter on a cation exchange resin, the studied optimum conditions of separation include a contact time of 3 minute and ph of 3.5 for the selective separation of beryllium from its EDTA solution after a prior separation of alum

  5. Leachability of cesium from cemented evaporator concentrates and ion-exchange resins

    International Nuclear Information System (INIS)

    Muurinen, A.

    1985-03-01

    Leachabilities of cesium from cemented evaporator concentrates and ion-exchange resins were measured. The standard draft of the International Organization for Standardization (ISO, 1979) for long-term leach testing was followed in the research. Three resin concretes and three concentrate concretes were tested. Deionized water and groundwater were used as leachants. The leaching temperature was 20-23 deg C. The incremental leach rate at the end of the three and a half year test varied between 5x10 -12 - 15x10 -12 m/s and the cumulative activity fraction leached between 1.5x10 -3 - 6x10 -3 m. The apparent diffusion coefficients in groundwater varied between 10 -9 - 10 -8 m/day. Because of the cracking the specimens cannot, however, be regarded as whole blocks, but the effects of cracking should be taken into account. (author)

  6. The effect of magnesium ion concentration on the fibrocartilage regeneration potential of goat costal chondrocytes.

    Science.gov (United States)

    Hagandora, Catherine K; Tudares, Mauro A; Almarza, Alejandro J

    2012-03-01

    Magnesium has recently been explored as a potential biomaterial for degradable orthopedic implants but its effect on fibrocartilage remains unknown. The objective of this study was to assess the effect of high concentrations of magnesium ions on the matrix production of goat costal fibrochondrocytes in vitro. Cells were cultured using a scaffoldless approach with media containing magnesium chloride (MgCl(2)) or magnesium sulfate (MgSO(4)) at concentrations of 20, 50, and 100 mM in addition to the baseline magnesium concentration of 0.8 mM MgSO(4). At 4 weeks, there were no significant differences in compressive tangent modulus and total matrix production between constructs cultured in 20 mM Mg(2+) and the 0.8 mM Mg(2+) control (435 ± 47 kPa). There was a significant decrease in compressive tangent modulus compared to the 0.8 mM Mg(2+) constructs in the 50 mM MgCl(2) and MgSO(4) groups, while the 100 mM groups were not mechanically testable (p < 0.05). The collagen and glycosaminoglycan (GAG) content of the 50 and 100 mM MgCl(2) and MgSO(4) constructs was significantly lower than the control (6.9 ± 0.5% and 16.5 ± 1.3% per dry weight, respectively) (p < 0.05). The results show that goat costal fibrochondrocytes exhibit a high degree of resiliency to magnesium ion concentrations up to 20 mM in vitro.

  7. The use of an ion-beam source to alter the surface morphology of biological implant materials

    Science.gov (United States)

    Weigand, A. J.

    1978-01-01

    An electron-bombardment ion-thruster was used as a neutralized-ion-beam sputtering source to texture the surfaces of biological implant materials. The materials investigated included 316 stainless steel; titanium-6% aluminum, 4% vanadium; cobalt-20% chromium, 15% tungsten; cobalt-35% nickel, 20% chromium, 10% molybdenum; polytetrafluoroethylene; polyoxymethylene; silicone and polyurethane copolymer; 32%-carbon-impregnated polyolefin; segmented polyurethane; silicone rubber; and alumina. Scanning electron microscopy was used to determine surface morphology changes of all materials after ion-texturing. Electron spectroscopy for chemical analysis was used to determine the effects of ion-texturing on the surface chemical composition of some polymers. Liquid contact angle data were obtained for ion-textured and untextured polymer samples. Results of tensile and fatigue tests of ion-textured metal alloys are presented. Preliminary data of tissue response to ion-textured surfaces of some metals, polytetrafluoroethylene, alumina, and segmented polyurethane have been obtained.

  8. Integrated pretreatment and desalination by electrocoagulation (EC)-ion concentration polarization (ICP) hybrid.

    Science.gov (United States)

    Choi, Siwon; Kim, Bumjoo; Han, Jongyoon

    2017-06-13

    Conventional water treatment process is composed of multiple stages, including desalination (salt removal) and pre/post-treatment of desalination to remove particles, chemicals, and other potential foulants for desalination. In this work, we developed a microfluidic proof-of-concept for a single device water treatment system, which removes both salt ions and non-salt contaminants. Our system combines electrocoagulation (EC), a versatile contaminant removal process, and ion concentration polarization (ICP) desalination, which is an electromembrane desalination process. We demonstrated a continuous EC-ICP operation that removed >95% of suspended solids and reduced the salinity from brackish range (20 mM NaCl) to a potable level (<8.6 mM NaCl). We also demonstrated that our system is flexible in terms of the type and concentration of contaminants it can handle. Combining two different electrochemical processes into a single system, we can reduce unnecessary voltage drop by having a shared anode, and achieve both seamless integration and energy efficient operation. Our system will find applications as a small-scale water treatment system, if properly scaled up in the future.

  9. THE HYDROGEN ION CONCENTRATION OF JOINT EXUDATES IN RHEUMATIC FEVER AND OTHER FORMS OF ARTHRITIS.

    Science.gov (United States)

    Boots, R H; Cullen, G E

    1922-09-30

    1. The hydrogen ion concentration of joint exudates aspirated from patients ill with acute rheumatic fever, arthritis of undetermined origin, and bacterial arthritis was determined. The hydrogen ion concentrations of the joint exudates from patients with acute rheumatic fever approximated the normal reaction of blood, varying from pH 7.27 to 7.42. Exudates from patients with arthritis of undetermined origin varied in pH from 7.33 to 7.47. The pH of a joint effusion occurring in a patient with myocardial insufficiency was 7.34. Bacteriologically, all of these fluids were sterile by ordinary means of cultivation. An exudate aspirated from a knee infected with Staphylococcus aureus had a pH of 6.69, while that from a patient having an arthritis due to Streptococcus hoemolyticus was also acid, having a pH of 6.19. 2. Since a definitely acid medium is necessary for the liberation of free salicylic acid and since all of the joint fluids from patients with acute rheumatic fever were slightly alkaline, no free salicylic acid could possibly exist in such joint fluids following the administration of salicylates.

  10. Concentration of ions in selected bottled water samples sold in Malaysia

    Science.gov (United States)

    Aris, Ahmad Zaharin; Kam, Ryan Chuan Yang; Lim, Ai Phing; Praveena, Sarva Mangala

    2013-03-01

    Many consumers around the world, including Malaysians, have turned to bottled water as their main source of drinking water. The aim of this study is to determine the physical and chemical properties of bottled water samples sold in Selangor, Malaysia. A total of 20 bottled water brands consisting of `natural mineral (NM)' and `packaged drinking (PD)' types were randomly collected and analyzed for their physical-chemical characteristics: hydrogen ion concentration (pH), electrical conductivity (EC) and total dissolved solids (TDS), selected major ions: calcium (Ca), potassium (K), magnesium (Mg) and sodium (Na), and minor trace constituents: copper (Cu) and zinc (Zn) to ascertain their suitability for human consumption. The results obtained were compared with guideline values recommended by World Health Organization (WHO) and Malaysian Ministry of Health (MMOH), respectively. It was found that all bottled water samples were in accordance with the guidelines set by WHO and MMOH except for one sample (D3) which was below the pH limit of 6.5. Both NM and PD bottled water were dominated by Na + K > Ca > Mg. Low values for EC and TDS in the bottled water samples showed that water was deficient in essential elements, likely an indication that these were removed by water treatment. Minerals like major ions were present in very low concentrations which could pose a risk to individuals who consume this water on a regular basis. Generally, the overall quality of the supplied bottled water was in accordance to standards and guidelines set by WHO and MMOH and safe for consumption.

  11. Development of ion-exchange properties of bamboo charcoal modified with concentrated nitric acid

    Science.gov (United States)

    Khandaker, S.; Kuba, T.; Toyohara, Y.; Kamida, S.; Uchikawa, Y.

    2017-08-01

    The surface chemistry and the structural properties of activated carbon can be altered by the acidic modification. The objective of this study is to investigate the changes occurring in bamboo charcoal (BC) during activation with concentrated nitric acid. Low temperature (500°C) carbonized BC has been prepared and oxidized with 70% concentrated boiling nitric acid (BC-AC). The porous properties of the BC are analyzed with nitrogen adsorption isotherm at 77 K. The surface structure is observed by Field emission scanning electronic microscope (FESEM) and the surface functional groups are examined by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and the pH of the point of zero charge (pHPZC). The results reveal that severe oxidation with HNO3 considerably decreases the surface area of BC with enhanced pore widening and FESEM observation demonstrates the erosive effect of oxidation. The FTIR analysis detects that some absorption bands are assigned for carboxyl, aldehyde and ketone groups on BC-AC. The XPS analysis also clearly shows that the ratio of oxygen and acidic functional groups has been enriched significantly on the BC-AC. The low pHPZC value of BC-AC confirms that the surface is highly acidic for the fixation of acidic functional groups on surface. In general, the existence of the abundant amount of acidic functional groups on adsorbents enhances the sorption of heavy metals ions in aqueous solution. Therefore, it is strongly expected that the modified BC, activated under the proposed conditions would be a promising ion exchanger in aqueous solution and can be applied for the adsorption of different heavy metal ions and radioactive materials from effluent.

  12. Influence of hydrogen-ion concentration exponent on undrained shear behaviour of bentonites; Bentonaito no hihaisui sendan kyodo ni oyobosu suiso ion nodo shisu no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Kamei, T [Kiso Jiban Consultants Co. Ltd., Tokyo (Japan); Tokida, M [Nagano National College of Technology, Nagano (Japan)

    1994-12-21

    Because there is a report example that the yield stress of a landslide clay increases along with a decrease of a hydrogen-ion concentration exponent, it is thought that a shear strength of the landslide clay depends on the hydrogen-ion concentration exponent. Furthermore, when the soil stabilization method by lime is applied to the soft ground and high organic earth, it is pointed out that the hydrogen-ion concentration exponent will become one of the harmful factors. Accordingly, it is understood that revealing an influence of a hydrogen-ion concentration exponent affects on the characteristics of an earth is one of the important factors, to evaluate a strength, deformation and so forth of the viscous ground. In this study, in order to examine an influence of a hydrogen-ion concentration exponent affecting on an undrained shear behavior of the bentonites, for the artificially adjusted bentonite specimens with 5 kinds of different pH, the isotropic consolidated undrained triaxial compression tests were performed, and consequently an influence of pH affecting on the engineering characteristics of the bentonites was made clear quantitatively. 28 refs., 16 figs., 5 tabs.

  13. Biological effects of tritium on fish cells in the concentration range of international drinking water standards.

    Science.gov (United States)

    Stuart, Marilyne; Festarini, Amy; Schleicher, Krista; Tan, Elizabeth; Kim, Sang Bog; Wen, Kendall; Gawlik, Jilian; Ulsh, Brant

    2016-10-01

    To evaluate whether the current Canadian tritium drinking water limit is protective of aquatic biota, an in vitro study was designed to assess the biological effects of low concentrations of tritium, similar to what would typically be found near a Canadian nuclear power station, and higher concentrations spanning the range of international tritium drinking water standards. Channel catfish peripheral blood B-lymphoblast and fathead minnow testis cells were exposed to 10-100,000 Bq l(-1) of tritium, after which eight molecular and cellular endpoints were assessed. Increased numbers of DNA strand breaks were observed and ATP levels were increased. There were no increases in γH2AX-mediated DNA repair. No differences in cell growth were noted. Exposure to the lowest concentrations of tritium were associated with a modest increase in the viability of fathead minnow testicular cells. Using the micronucleus assay, an adaptive response was observed in catfish B-lymphoblasts. Using molecular endpoints, biological responses to tritium in the range of Canadian and international drinking water standards were observed. At the cellular level, no detrimental effects were noted on growth or cycling, and protective effects were observed as an increase in cell viability and an induced resistance to a large challenge dose.

  14. Measurement of the Cupric Ion Concentration Variation near Electrodes in the Copper Electroplating System

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Je Young; Chung, Bum Jin [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The heat fluxes to the side wall imposed at the upper metallic layer, are known to increase with the reduction of layer height. This 'Focusing effect' is varied by cooling condition of upper boundary and height of the metallic layer. The heat transfer experiments were replaced by mass transfer experiments based on the heat and mass transfer analogy concept. When the electroplating system is adopted as the mass transfer system, in order to simulate the different temperature conditions of top and side walls, an electrical resistance was attached to the top wall so that it is mimics hotter wall condition. Because the quantitative temperature conditions according to the electrical resistance were unknown, the methodology development is necessary. The electrical resistance was adopted to the top plate. But the quantitative temperature conditions depending on the electrical resistance were unknown. In order to overcome the limitations of mass transfer, this work tried to measure the cupric ion concentration. The methods of concentration measurement are RGB, Brightness, ICP, PIV, and Interferometry. The key of RGB, Brightness and PIV method is the clear images of the concentration boundary layer corresponding the thermal boundary layer of heat transfer. The results for ICP method can be got by taking the trace sample of a solution, accurately. The formation of patterns in the interferometry is very important. The characteristics of the interference pattern depend on the nature of the light source, the precise orientation of the mirrors, etc. The methodology of concentration measurement is still under development stage.

  15. Measurement of the Cupric Ion Concentration Variation near Electrodes in the Copper Electroplating System

    International Nuclear Information System (INIS)

    Moon, Je Young; Chung, Bum Jin

    2016-01-01

    The heat fluxes to the side wall imposed at the upper metallic layer, are known to increase with the reduction of layer height. This 'Focusing effect' is varied by cooling condition of upper boundary and height of the metallic layer. The heat transfer experiments were replaced by mass transfer experiments based on the heat and mass transfer analogy concept. When the electroplating system is adopted as the mass transfer system, in order to simulate the different temperature conditions of top and side walls, an electrical resistance was attached to the top wall so that it is mimics hotter wall condition. Because the quantitative temperature conditions according to the electrical resistance were unknown, the methodology development is necessary. The electrical resistance was adopted to the top plate. But the quantitative temperature conditions depending on the electrical resistance were unknown. In order to overcome the limitations of mass transfer, this work tried to measure the cupric ion concentration. The methods of concentration measurement are RGB, Brightness, ICP, PIV, and Interferometry. The key of RGB, Brightness and PIV method is the clear images of the concentration boundary layer corresponding the thermal boundary layer of heat transfer. The results for ICP method can be got by taking the trace sample of a solution, accurately. The formation of patterns in the interferometry is very important. The characteristics of the interference pattern depend on the nature of the light source, the precise orientation of the mirrors, etc. The methodology of concentration measurement is still under development stage.

  16. Concentration and characteristics of depleted uranium in biological and water samples collected in Bosnia and Herzegovina

    International Nuclear Information System (INIS)

    Jia Guogang; Belli, Maria; Sansone, Umberto; Rosamilia, Silvia; Gaudino, Stefania

    2006-01-01

    During Balkan conflicts in 1994-1995, depleted uranium (DU) ordnance was employed and was left in the battlefield. Health concern is related to the risk arising from contamination of the environment with DU penetrators and dust. In order to evaluate the impact of DU on the environment and population in Bosnia and Herzegovina, radiological survey of DU in biological and water samples were carried out over the period 12-24 October 2002. The uranium isotopic concentrations in biological samples collected in Bosnia and Herzegovina, mainly lichens, mosses and barks, were found to be in the range of 0.27-35.7 Bq kg -1 for 238 U, 0.24-16.8 Bq kg -1 for 234 U, and 0.02-1.11 Bq kg -1 for 235 U, showing uranium levels to be higher than in the samples collected at the control site. Moreover, the 236 U in some of the samples was detectable. The isotopic ratios of 234 U/ 238 U showed DU to be detectable in many biological samples at most sites examined, but in very low levels. The presence of DU in the biological samples was as a result of DU contamination in air. The uranium concentrations in water samples collected in Bosnia and Herzegovina were found to be in the range of 0.27-16.2 mBq l -1 for 238 U, 0.41-15.6 mBq l -1 for 234 U and 0.012-0.695 mBq l -1 for 235 U, and two water samples were observed to be DU positive; these values are much lower than those in mineral water found in central Italy and below the WHO guideline for public drinking water. From radiotoxicological point of view, at this moment there is no significant radiological risk related to these investigated sites in terms of possible DU contamination of water and/or plants

  17. Selective removal of arsenic and monovalent ions from brackish water reverse osmosis concentrate.

    Science.gov (United States)

    Xu, Pei; Capito, Marissa; Cath, Tzahi Y

    2013-09-15

    Concentrate disposal and management is a considerable challenge for the implementation of desalination technologies, especially for inland applications where concentrate disposal options are limited. This study has focused on selective removal of arsenic and monovalent ions from brackish groundwater reverse osmosis (RO) concentrate for beneficial use and safe environmental disposal using in situ and pre-formed hydrous ferric oxides/hydroxides adsorption, and electrodialysis (ED) with monovalent permselective membranes. Coagulation with ferric salts is highly efficient at removing arsenic from RO concentrate to meet a drinking water standard of 10 μg/L. The chemical demand for ferric chloride however is much lower than ferric sulfate as coagulant. An alternative method using ferric sludge from surface water treatment plant is demonstrated as an efficient adsorbent to remove arsenic from RO concentrate, providing a promising low cost, "waste treat waste" approach. The monovalent permselective anion exchange membranes exhibit high selectivity in removing monovalent anions over di- and multi-valent anions. The transport of sulfate and phosphate through the anion exchange membranes was negligible over a broad range of electrical current density. However, the transport of divalent cations such as calcium and magnesium increases through monovalent permselective cation exchange membranes with increasing current density. Higher overall salt concentration reduction is achieved around limiting current density while higher normalized salt removal rate in terms of mass of salt per membrane area and applied energy is attained at lower current density because the energy unitization efficiency decreases at higher current density. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Interpretation of biological-rate coefficients derived from radionuclide content, radionuclide concentration and specific activity experiments

    International Nuclear Information System (INIS)

    Vanderploeg, H.A.; Booth, R.S.

    1976-01-01

    Rigorous expressions are derived for the biological-rate coefficients (BRCs) determined from time-dependent measurements of three different dependent variables of radionuclide tracer experiments. These variables, which apply to a single organism, are radionuclide content, radionuclide concentration and specific activity. The BRCs derived from these variables have different mathematical expressions and, for high growth rates, their numerical values can be quite different. The precise mathematical expressions for the BRCs are presented here to aid modelers in selecting the correct parameters for their models and to aid experiments in interpreting their results. The usefulness of these three variables in quantifying elemental uptakes and losses by organisms is discussed. (U.K.)

  19. Comparison of Biological Effectiveness of Carbon-Ion Beams in Japan and Germany

    International Nuclear Information System (INIS)

    Uzawa, Akiko; Ando, Koichi; Koike, Sachiko; Furusawa, Yoshiya; Matsumoto, Yoshitaka; Takai, Nobuhiko; Hirayama, Ryoichi; Watanabe, Masahiko; Scholz, Michael; Elsaesser, Thilo; Peschke, Peter

    2009-01-01

    Purpose: To compare the biological effectiveness of 290 MeV/amu carbon-ion beams in Chiba, Japan and in Darmstadt, Germany, given that different methods for beam delivery are used for each. Methods and Materials: Murine small intestine and human salivary gland tumor (HSG) cells exponentially growing in vitro were irradiated with 6-cm width of spread-out Bragg peaks (SOBPs) adjusted to achieve nearly identical beam depth-dose profiles at the Heavy-Ion Medical Accelerator in Chiba, and the SchwerIonen Synchrotron in Darmstadt. Cell kill efficiencies of carbon ions were measured by colony formation for HSG cells and jejunum crypts survival in mice. Cobalt-60 γ rays were used as the reference radiation. Isoeffective doses at given survivals were used for relative biological effectiveness (RBE) calculations and interinstitutional comparisons. Results: Isoeffective D 10 doses (mean ± standard deviation) of HSG cells ranged from 2.37 ± 0.14 Gy to 3.47 ± 0.19 Gy for Chiba and from 2.31 ± 0.11 Gy to 3.66 ± 0.17 Gy for Darmstadt. Isoeffective D 10 doses of gut crypts after single doses ranged from 8.25 ± 0.17 Gy to 10.32 ± 0.14 Gy for Chiba and from 8.27 ± 0.10 Gy to 10.27 ± 0.27 Gy for Darmstadt, whereas isoeffective D 30 doses after three fractionated doses were 9.89 ± 0.17 Gy through 13.70 ± 0.54 Gy and 10.14 ± 0.20 Gy through 13.30 ± 0.41 Gy for Chiba and Darmstadt, respectively. Overall difference of RBE between the two facilities was 0-5% or 3-7% for gut crypt survival or HSG cell kill, respectively. Conclusion: The carbon-ion beams at the National Institute of Radiological Sciences in Chiba, Japan and the Gesellschaft fuer Schwerionenforschung in Darmstadt, Germany are biologically identical after single and daily fractionated irradiation.

  20. The Effect of Low Level Laser Therapy on Some Plasma Ions Concentration

    Directory of Open Access Journals (Sweden)

    Nadia H. Sahib

    2017-12-01

    two pore leak channels(K2P, which act as signal integrators from the periphery to the cortex. Objectives and Results Fifteen blood samples were collected from healthy adult volunteers, subjected to low level laser therapy  (LLLT with different wavelengths (650, 532 and 405 nm, plasma concentration of Ca++, Na+, K+ and Cl- were estimated after (30 min. of incubation. The mean concentration of each ion before and after LLLT were as follows (Ca++: 8.67 vs. 8.93, 8.79, 8.82 mg/dl, (Na+: 147.4 vs. 146.73, 146.73, 146.13 mmol/L, (K+: 3.94 vs. 3.94, 3.78, 3.92 mmol/L and (Cl-: 99.93 vs. 97.86, 102.73, 96.4 mmol/L. In the same manner, activated partial thromboplastin time (APTT was estimated, the mean value of which were as follows (30.07 vs. 18.45, 21.72, 17.29 sec..

  1. Quantification of the Relative Biological Effectiveness for Ion Beam Radiotherapy: Direct Experimental Comparison of Proton and Carbon Ion Beams and a Novel Approach for Treatment Planning

    International Nuclear Information System (INIS)

    Elsaesser, Thilo; Weyrather, Wilma K.; Friedrich, Thomas; Durante, Marco; Iancu, Gheorghe; Kraemer, Michael; Kragl, Gabriele; Brons, Stephan; Winter, Marcus; Weber, Klaus-Josef; Scholz, Michael

    2010-01-01

    Purpose: To present the first direct experimental in vitro comparison of the biological effectiveness of range-equivalent protons and carbon ion beams for Chinese hamster ovary cells exposed in a three-dimensional phantom using a pencil beam scanning technique and to compare the experimental data with a novel biophysical model. Methods and Materials: Cell survival was measured in the phantom after irradiation with two opposing fields, thus mimicking the typical patient treatment scenario. The novel biophysical model represents a substantial extension of the local effect model, previously used for treatment planning in carbon ion therapy for more than 400 patients, and potentially can be used to predict effectiveness of all ion species relevant for radiotherapy. A key feature of the new approach is the more sophisticated consideration of spatially correlated damage induced by ion irradiation. Results: The experimental data obtained for Chinese hamster ovary cells clearly demonstrate that higher cell killing is achieved in the target region with carbon ions as compared with protons when the effects in the entrance channel are comparable. The model predictions demonstrate agreement with these experimental data and with data obtained with helium ions under similar conditions. Good agreement is also achieved with relative biological effectiveness values reported in the literature for other cell lines for monoenergetic proton, helium, and carbon ions. Conclusion: Both the experimental data and the new modeling approach are supportive of the advantages of carbon ions as compared with protons for treatment-like field configurations. Because the model predicts the effectiveness for several ion species with similar accuracy, it represents a powerful tool for further optimization and utilization of the potential of ion beams in tumor therapy.

  2. Dynamics of Intracellular Polymers in Enhanced Biological Phosphorus Removal Processes under Different Organic Carbon Concentrations

    Directory of Open Access Journals (Sweden)

    Lizhen Xing

    2013-01-01

    Full Text Available Enhanced biological phosphorus removal (EBPR may deteriorate or fail during low organic carbon loading periods. Polyphosphate accumulating organisms (PAOs in EBPR were acclimated under both high and low organic carbon conditions, and then dynamics of polymers in typical cycles, anaerobic conditions with excess organic carbons, and endogenous respiration conditions were examined. After long-term acclimation, it was found that organic loading rates did not affect the yield of PAOs and the applied low organic carbon concentrations were advantageous for the enrichment of PAOs. A low influent organic carbon concentration induced a high production of extracellular carbohydrate. During both anaerobic and aerobic endogenous respirations, when glycogen decreased to around 80 ± 10 mg C per gram of volatile suspended solids, PAOs began to utilize polyphosphate significantly. Regressed by the first-order reaction model, glycogen possessed the highest degradation rate and then was followed by polyphosphate, while biomass decay had the lowest degradation rate.

  3. Variations in Calcium and Alginate Ions Concentration in Relation to the Properties of Calcium Alginate Nanoparticles

    Directory of Open Access Journals (Sweden)

    Hamed Daemi

    2013-05-01

    Full Text Available Alginate belongs to a group of natural polymers called polysaccharides. They have carboxylic functional groups beside hydroxyls which are common in all polysaccharides. These materials show interesting properties due to theirfunctional groups. One of these properties is the ability of this polymer as a suitable carrier of protecting and transferring drugs and biomolecules. The particle sizes of these polymers are very important for their applications, so different techniques were used for preparation of these materials. In this way polymeric nanoparticles of calcium alginate which are excellent carriers in drug delivery systems were prepared by addition of calcium chloride solution to dilute solution of sodium alginate. Investigation of the size and distribution of nanoparticles were analyzed by SEM method. The concentration effects of both alginate and calcium ions on the size and distribution of  nanoparticles were studied in this research. Results showed that the size of nanoparticles obviously decreased with decreasing polymeric alginate concentration because of lower active sites in polymer chain. On the other hand, thesize and distribution of nanoparticles are significantly improved with increase of calcium cation concentrations. The mean particle size 40-70 nm and spherical shape are the main characteristics of the prepared nanoparticles.

  4. Determination of the free ion concentration of trace metals in soil solution using a soil column Donnan membrane technique

    NARCIS (Netherlands)

    Weng, L.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2001-01-01

    Accurate measurement of the free metal ion is difficult, especially for trace metals present in very small concentrations (less than micromolar) in natural systems. The recently developed Donnan membrane technique can measure the concentrations in solution in the presence of inorganic and organic

  5. The hemodynamic effect of calcium ion concentration in the infusate during predilution hemofiltration in chronic renal failure

    DEFF Research Database (Denmark)

    Karamperis, N.; Sloth, E.; Jensen, Jens Dam

    2005-01-01

    BACKGROUND: It is the prevailing view that convective dialysis techniques stabilize blood pressure. Calcium concentration in the substitution fluid may be important in this respect. The aim of this study is to investigate the influence of calcium ion concentration in the substitution fluid on hem...

  6. pH buffers for sea water media based on the total hydrogen ion concentration scale

    Science.gov (United States)

    Dickson, Andrew G.

    1993-01-01

    Published e.m.f. values measured using the cell ? where p° = 101.325 kPa, and BH + and B are the conjugate acid-base pairs of 2-aminopyridine, 2-amino-2-hydroxymethyl-1,3-propanediol (tris), tetrahydro-1,4-isoxazine (morpholine), and 2-amino-2-methyl-1, 3-propanediol (bis), have been re-evaluated to assign pH values based on the "total" hydrogen ion concentration scale to equimolal ( m =0.04 mol kg -1) buffer solutions based on these compounds. These pH values are consistent with the best available equilibrium constants for acid-base processes in sea water and such pH buffers can be used as pH calibration standards to measure accurate values for oceanic pH on the "total" hydrogen ion pH scale. In addition, the published e.m.f. results for these various amine bases have been used to calculate their respective acidity constants on this pH scale.

  7. [Effect of high magnesium ion concentration on the electron transport rate and proton exchange in thylakoid membranes in higher plants].

    Science.gov (United States)

    Ignat'ev, A R; Khorobrykh, S A; Ivanov, B N

    2001-01-01

    The effects of magnesium ion concentration on the rate of electron transport in isolated pea thylakoids were investigated in the pH range from 4.0 up to 8.0. In the absence of magnesium ions in the medium and in the presence of 5 mM MgCl2 in the experiments not only without added artificial acceptors but also with ferricyanide or methylviologen as an acceptor, this rate had a well-expressed maximum at pH 5.0. It was shown that, after depression to minimal values at pH 5.5-6.5, it gradually rose with increasing pH. An increase in magnesium ion concentration up to 20 mM essentially affected the electron transfer rate: it decreased somewhat at pH 4.0-5.0 but increased at higher pH values. At this magnesium ion concentration, the maximum rate was at pH 6.0-6.5 and the minimum, at pH 7.0. Subsequent rise upon increasing pH to 8.0 was expressed more sharply. The influence of high magnesium ion concentration on the rate of electron transport was not observed in the presence of gramicidin D. It was found that without uncoupler, the changes in the electron transfer rate under the influence of magnesium ions correlated to the changes in the first-order rate constant of the proton efflux from thylakoids. It is supposed that the change in the ability of thylakoids to keep protons by the action of magnesium ions is the result of electrostatic interactions of these ions with the charges on the external surface of membranes. A possible role of regulation of the electron transport rate by magnesium ions in vivo is discussed.

  8. Sorption properties of algae Spirogyra sp. and their use for determination of heavy metal ions concentrations in surface water.

    Science.gov (United States)

    Rajfur, Małgorzata; Kłos, Andrzej; Wacławek, Maria

    2010-11-01

    Kinetics of heavy-metal ions sorption by alga Spirogyra sp. was evaluated experimentally in the laboratory, using both the static and the dynamic approach. The metal ions--Mn(2+), Cu(2+), Zn(2+) and Cd(2+)--were sorbed from aqueous solutions of their salts. The static experiments showed that the sorption equilibria were attained in 30 min, with 90-95% of metal ions sorbed in first 10 min of each process. The sorption equilibria were approximated with the Langmuir isotherm model. The algae sorbed each heavy metal ions proportionally to the amount of this metal ions in solution. The experiments confirmed that after 30 min of exposition to contaminated water, the concentration of heavy metal ions in the algae, which initially contained small amounts of these metal ions, increased proportionally to the concentration of metal ions in solution. The presented results can be used for elaboration of a method for classification of surface waters that complies with the legal regulations. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Dependence of ion - photon emission characteristics on the concentration of implanted atoms of the bombarding beam

    International Nuclear Information System (INIS)

    Belykh, S.F.; Evtukhov, R.N.; Redina, I.V.; Ferleger, V.Kh.

    1989-01-01

    Results of experiment, where Dy + beams, its spraying products emitting intensively optical radiation with continuous spectrum (CSR), are used for tantalum surface bombardment, are presented. The given experiment allowed one to separate the scattered particle CSR contribution and was conducted under controlled beam n atom concentration on the target surface. E 0 energy and j 0 dysprosium ion flux density made up respectively 3.5 keV and 3x10 5 Axcm -2 . The obtained result analysis has shown that a notable dependence of spectrum type on n value is detected. Dy scattered atoms to not emit CSR. The main contribution to CSR is made by sprayed particles, containing dysprosium atoms

  10. Spray-type drying unit for spent ion exchange resins, sludges and radioactive concentrates

    International Nuclear Information System (INIS)

    Raibaud, J.

    1986-01-01

    The process for drying radwaste in the liquid form or in aqueous suspension is a very attractive solution from the standpoint of volume reduction. Most of the existing drying facilities are not well adapted for drying the varieties of aqueous waste produced by the nuclear research centres and nuclear power plants, such as: - ion exchange resins, bead type or powdered resins, - centrifuge sludges, - settling sludges, - evaporator bottoms. Technicatome has selected the LEAFLASH process developed by Rhone Poulenc Recherches for drying the nuclear aqueous waste. This process has been well tried at full scale in a large number of industrial branches. The advantages of the process have been confirmed by the results obtained in operating a pilot facility. They include: - high flexibility in operation: - quick start-up and stoppage procedures, - adaptation to a wide spectrum of liquid waste without significant changes in the adjustment of the device. - compactness, - low power consumption, - complete drying of the waste for any initial concentration [fr

  11. Radiobiological experiments with heavy ions: a comparison of the cross sections of different biological endpoints

    International Nuclear Information System (INIS)

    Kraft, G.

    1989-01-01

    Biological effect of heavy charged particles was studied in experiment at the Unilac on different physical, chemical and biological levels. On these experiments a large body of radiobiological data, cross sections for cell inactivation and mutation, induction of both, chromosome aberrations, and strand breaks, of DNA have been measured for different atomic numbers, from helium (z=2) to uranium (z=92), and at an LET range from 10 to 16000 keV/μm. At LET values below 100 keV/μm all data points to one specific effect form one single curve as a function of LET, independent of the atomic number of the ion. In this LET range the biological effects are independent of the particle energy or track structure and depend only on the energy transfer. Therefore LET is a good parameter in this regime. For LET values greater than 100 keV/μm this regime LET is no longer a good parameter and the physical parameters of the formation of particle track are important. The energy and angular distribution of the electrons in a solid target has to be measured. 28 refs.; 14 figs

  12. Influence of chloride ion concentration on the corrosion behavior of Al-bearing TRIP steels

    International Nuclear Information System (INIS)

    El-Taib Heakal, F.; Tantawy, N.S.; Shehta, O.S.

    2011-01-01

    Highlights: → Systematic increase of chloride concentration has a critical influence on TRIP steel corrosion. → TRIP microalloyed with Nb and Cr showed lower corrosion rate and smaller threshold Cl - value. → Increasing Al content by 220 times in the TRIP deteriorates its corrosion behavior. → Impedance results and surface examinations confirmed the obtained results. - Abstract: The effect of a systematic increase of chloride ion concentration on the electrochemical corrosion behavior of two types of Al-bearing TRIP steels (T 1 and T 2 ) was studied in aqueous NaCl solutions. Several electrochemical techniques were used comprising open circuit potential measurements, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Chloride concentration has a critical influence on the corrosion rate of the two tested steel samples. For both steels the corrosion rate first increased with increasing chloride content up to a certain critical concentration (CC), and then decreased in solution with chloride level higher than the threshold value. TRIP steel T 1 microalloyed with Nb and Cr as compared to steel T 2 not containing these two elements, exhibited lower corrosion rate and smaller CC value, indicating better corrosion resistance to chloride attack, albeit the Al content in T 2 is 220 times higher than that in T 1 . This is because Nb alloyed with TRIP steel likely enhances the formation on the surface of a stable rust layer enriched with other passivating elements Al, Cu, Cr and Ni, which has higher corrosion resistance and hence improve greatly the passive performance of the TRIP sample. The ac impedance data are in good agreement with the OCP and dc polarization measurements. Surface examinations via scanning electron microscope confirmed well the obtained results.

  13. Influence of chloride ion concentration on the corrosion behavior of Al-bearing TRIP steels

    Energy Technology Data Exchange (ETDEWEB)

    El-Taib Heakal, F., E-mail: fakihaheakal@yahoo.com [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt); Tantawy, N.S. [Chemistry Department, Girl' s College for Arts, Science and Education, Ain Shams University, Cairo (Egypt); Shehta, O.S. [Physical Chemistry Department, National Research Centre, Dokki, Giza (Egypt)

    2011-10-17

    Highlights: {yields} Systematic increase of chloride concentration has a critical influence on TRIP steel corrosion. {yields} TRIP microalloyed with Nb and Cr showed lower corrosion rate and smaller threshold Cl{sup -} value. {yields} Increasing Al content by 220 times in the TRIP deteriorates its corrosion behavior. {yields} Impedance results and surface examinations confirmed the obtained results. - Abstract: The effect of a systematic increase of chloride ion concentration on the electrochemical corrosion behavior of two types of Al-bearing TRIP steels (T{sub 1} and T{sub 2}) was studied in aqueous NaCl solutions. Several electrochemical techniques were used comprising open circuit potential measurements, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Chloride concentration has a critical influence on the corrosion rate of the two tested steel samples. For both steels the corrosion rate first increased with increasing chloride content up to a certain critical concentration (CC), and then decreased in solution with chloride level higher than the threshold value. TRIP steel T{sub 1} microalloyed with Nb and Cr as compared to steel T{sub 2} not containing these two elements, exhibited lower corrosion rate and smaller CC value, indicating better corrosion resistance to chloride attack, albeit the Al content in T{sub 2} is 220 times higher than that in T{sub 1}. This is because Nb alloyed with TRIP steel likely enhances the formation on the surface of a stable rust layer enriched with other passivating elements Al, Cu, Cr and Ni, which has higher corrosion resistance and hence improve greatly the passive performance of the TRIP sample. The ac impedance data are in good agreement with the OCP and dc polarization measurements. Surface examinations via scanning electron microscope confirmed well the obtained results.

  14. Rapid localization of carbon 14-labeled molecules in biological samples by ion mass microscopy

    International Nuclear Information System (INIS)

    Hindie, E.; Escaig, F.; Coulomb, B.; Lebreton, C.; Galle, P.

    1989-01-01

    We report here on the ability of secondary ion mass spectrometry (SIMS) to provide rapid imaging of the intracellular distribution of 14 C-labeled molecules. The validity of this method, using mass discrimination of carbon 14 atoms, was assessed by imaging the distribution of two molecules of well-known metabolism, [ 14 C]-thymidine and [ 14 C]-uridine, incorporated by human fibroblasts in culture. As expected, 14 C ion images showed the presence of [ 14 C]-thymidine in the nucleus of dividing cells, whereas [ 14 C]-uridine was present in the cytoplasm as well as the nucleus of all cells, with a large concentration in the nucleoli. The time required to obtain the distribution images with the SMI 300 microscope was less than 6 min, whereas microautoradiography, the classical method for mapping the tissue distribution of 14 C-labeled molecules, usually requires exposure times of several months. Secondary ion mass spectrometry using in situ mass discrimination is proposed here as a very sensitive method which permits rapid imaging of the subcellular distribution of molecules labeled with carbon 14

  15. Permeating disciplines: Overcoming barriers between molecular simulations and classical structure-function approaches in biological ion transport.

    Science.gov (United States)

    Howard, Rebecca J; Carnevale, Vincenzo; Delemotte, Lucie; Hellmich, Ute A; Rothberg, Brad S

    2018-04-01

    Ion translocation across biological barriers is a fundamental requirement for life. In many cases, controlling this process-for example with neuroactive drugs-demands an understanding of rapid and reversible structural changes in membrane-embedded proteins, including ion channels and transporters. Classical approaches to electrophysiology and structural biology have provided valuable insights into several such proteins over macroscopic, often discontinuous scales of space and time. Integrating these observations into meaningful mechanistic models now relies increasingly on computational methods, particularly molecular dynamics simulations, while surfacing important challenges in data management and conceptual alignment. Here, we seek to provide contemporary context, concrete examples, and a look to the future for bridging disciplinary gaps in biological ion transport. This article is part of a Special Issue entitled: Beyond the Structure-Function Horizon of Membrane Proteins edited by Ute Hellmich, Rupak Doshi and Benjamin McIlwain. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Application of Fourier transform infrared ellipsometry to assess the concentration of biological molecules

    Science.gov (United States)

    Garcia-Caurel, Enric; Drevillon, Bernard; De Martino, Antonello; Schwartz, Laurent

    2002-12-01

    Spectroscopic ellipsometry is a noninvasive optical characterization technique mainly used in the semiconductor field to characterize bare substrates and thin films. In particular, it allows the gathering of information concerning the physical structure of the sample, such as roughness and film thickness, as well as its optical response. In the mid-infrared (IR) range each molecule exhibits a characteristic absorption fingerprint, which makes this technique chemically selective. Phase-modulated IR ellipsometry does not require a baseline correction procedure or suppression of atmospheric CO2 and water-vapor absorption bands, thus greatly reducing the subjectivity in data analysis. We have found that ellipsometric measurements of thin films, such as the solid residuals left on a plane surface after evaporation of a liquid drop containing a given compound in solution, are particularly favorable for dosing purposes because the intensity of IR absorptions shows a linear behavior along a wide range of solution concentrations of the given compound. Our aim is to illustrate with a concrete example and to justify theoretically the linearity experimentally found between radiation absorption and molecule concentration. For the example, we prepared aqueous solutions of glycogen, a molecule of huge biological importance currently tested in biochemical analyses, at concentrations ranging from 1 mg/l to 1 g/l, which correspond to those found in physiological conditions. The results of this example are promising for the application of ellipsometry for dosing purposes in biochemistry and biomedicine.

  17. Engineering Bacteria to Search for Specific Concentrations of Molecules by a Systematic Synthetic Biology Design Method.

    Science.gov (United States)

    Tien, Shin-Ming; Hsu, Chih-Yuan; Chen, Bor-Sen

    2016-01-01

    Bacteria navigate environments full of various chemicals to seek favorable places for survival by controlling the flagella's rotation using a complicated signal transduction pathway. By influencing the pathway, bacteria can be engineered to search for specific molecules, which has great potential for application to biomedicine and bioremediation. In this study, genetic circuits were constructed to make bacteria search for a specific molecule at particular concentrations in their environment through a synthetic biology method. In addition, by replacing the "brake component" in the synthetic circuit with some specific sensitivities, the bacteria can be engineered to locate areas containing specific concentrations of the molecule. Measured by the swarm assay qualitatively and microfluidic techniques quantitatively, the characteristics of each "brake component" were identified and represented by a mathematical model. Furthermore, we established another mathematical model to anticipate the characteristics of the "brake component". Based on this model, an abundant component library can be established to provide adequate component selection for different searching conditions without identifying all components individually. Finally, a systematic design procedure was proposed. Following this systematic procedure, one can design a genetic circuit for bacteria to rapidly search for and locate different concentrations of particular molecules by selecting the most adequate "brake component" in the library. Moreover, following simple procedures, one can also establish an exclusive component library suitable for other cultivated environments, promoter systems, or bacterial strains.

  18. Engineering Bacteria to Search for Specific Concentrations of Molecules by a Systematic Synthetic Biology Design Method.

    Directory of Open Access Journals (Sweden)

    Shin-Ming Tien

    Full Text Available Bacteria navigate environments full of various chemicals to seek favorable places for survival by controlling the flagella's rotation using a complicated signal transduction pathway. By influencing the pathway, bacteria can be engineered to search for specific molecules, which has great potential for application to biomedicine and bioremediation. In this study, genetic circuits were constructed to make bacteria search for a specific molecule at particular concentrations in their environment through a synthetic biology method. In addition, by replacing the "brake component" in the synthetic circuit with some specific sensitivities, the bacteria can be engineered to locate areas containing specific concentrations of the molecule. Measured by the swarm assay qualitatively and microfluidic techniques quantitatively, the characteristics of each "brake component" were identified and represented by a mathematical model. Furthermore, we established another mathematical model to anticipate the characteristics of the "brake component". Based on this model, an abundant component library can be established to provide adequate component selection for different searching conditions without identifying all components individually. Finally, a systematic design procedure was proposed. Following this systematic procedure, one can design a genetic circuit for bacteria to rapidly search for and locate different concentrations of particular molecules by selecting the most adequate "brake component" in the library. Moreover, following simple procedures, one can also establish an exclusive component library suitable for other cultivated environments, promoter systems, or bacterial strains.

  19. Electrochemical detection of copper ions leached from CuO nanoparticles in saline buffers and biological media using a gold wire working electrode

    Energy Technology Data Exchange (ETDEWEB)

    Baldisserri, Carlo, E-mail: carlo.baldisserri@istec.cnr.it; Costa, Anna Luisa [ISTEC-CNR (Italy)

    2016-04-15

    We performed explorative cyclic voltammetry in phosphate-buffered saline buffers, Dulbecco’s modified Eagle’s medium (DMEM), and fetal bovine serum-added DMEM using Au wire as working electrode, both in the absence and in the presence of known nominal concentrations of Cu{sup 2+} ions or 15 nm CuO nanoparticles. Addition of either Cu{sup 2+} ions or aqueous suspension of CuO nanoparticles caused a single anodic peak to appear in the double-layer region of all three pristine media. The height of the anodic peak was found to increase in a monotonic fashion vs. Cu{sup 2+} concentration in Cu{sup 2+}-added media, and versus time since CuO addition in CuO-added media. Stepwise addition of glycine to Cu{sup 2+}-added phosphate-buffered saline buffer caused an increasing cathodic shift of the anodic peak accompanied by decreasing peak currents. Results indicate that preparing Cu{sup 2+}-free suspensions of CuO nanoparticles in such media is difficult, owing to the presence of leached copper ions. The implications on results of experiments in which CuO nanoparticle-added biological media are used as cell culture substrates are discussed. Literature data on the interactions between Cu{sup 2+} ions, dissolved carbon dioxide in aqueous CuO suspensions, and amino acids present in such media are compared to our results.

  20. Electrochemical detection of copper ions leached from CuO nanoparticles in saline buffers and biological media using a gold wire working electrode

    Science.gov (United States)

    Baldisserri, Carlo; Costa, Anna Luisa

    2016-04-01

    We performed explorative cyclic voltammetry in phosphate-buffered saline buffers, Dulbecco's modified Eagle's medium (DMEM), and fetal bovine serum-added DMEM using Au wire as working electrode, both in the absence and in the presence of known nominal concentrations of Cu2+ ions or 15 nm CuO nanoparticles. Addition of either Cu2+ ions or aqueous suspension of CuO nanoparticles caused a single anodic peak to appear in the double-layer region of all three pristine media. The height of the anodic peak was found to increase in a monotonic fashion vs. Cu2+ concentration in Cu2+-added media, and versus time since CuO addition in CuO-added media. Stepwise addition of glycine to Cu2+-added phosphate-buffered saline buffer caused an increasing cathodic shift of the anodic peak accompanied by decreasing peak currents. Results indicate that preparing Cu2+-free suspensions of CuO nanoparticles in such media is difficult, owing to the presence of leached copper ions. The implications on results of experiments in which CuO nanoparticle-added biological media are used as cell culture substrates are discussed. Literature data on the interactions between Cu2+ ions, dissolved carbon dioxide in aqueous CuO suspensions, and amino acids present in such media are compared to our results.

  1. Spectroscopic and redox properties of curium and californium ions in concentrated aqueous carbonate-bicarbonate media

    International Nuclear Information System (INIS)

    Hobart, D.E.; Varlashkin, P.G.; Samhoun, K.; Haire, R.G.; Peterson, J.R.

    1983-01-01

    Multimilligram quantities of trivalent curium-248 and californium-249 were investigated by absorption spectroscopy, cyclic voltammetry, and bulk solution electrolysis in concentrated aqueous carbonate-bicarbonate solution. Actinide concentrations between 10 -4 and 10 -2 M were studied in 2 M sodium carbonate and 5.5 M potassium carbonate solutions at pH values from 8 to 14. The solution absorption spectra of Cm(III) and Cf(III) in carbonate media are presented for the first time and compared to literature spectra of these species in noncomplexing aqueous solution. It was anticipated that carbonate complexation of the actinide ions could provide a sufficient negative shift in the formal potentials of the M(IV)/M(III) couples of Cm and Cf to permit the generation and stabilization of their tetravalent states in aqueous carbonate-bicarbonate medium. No conclusive evidence was found in the present work to indicate the existence of any higher oxidation states of curium or californium in carbonate solution. Some possible reasons for our inability to generate and detect oxidized species of curium and californium in this medium are discussed

  2. Microfluidic paper-based biomolecule preconcentrator based on ion concentration polarization.

    Science.gov (United States)

    Han, Sung Il; Hwang, Kyo Seon; Kwak, Rhokyun; Lee, Jeong Hoon

    2016-06-21

    Microfluidic paper-based analytical devices (μPADs) for molecular detection have great potential in the field of point-of-care diagnostics. Currently, a critical problem being faced by μPADs is improving their detection sensitivity. Various preconcentration processes have been developed, but they still have complicated structures and fabrication processes to integrate into μPADs. To address this issue, we have developed a novel paper-based preconcentrator utilizing ion concentration polarization (ICP) with minimal addition on lateral-flow paper. The cation selective membrane (i.e., Nafion) is patterned on adhesive tape, and this tape is then attached to paper-based channels. When an electric field is applied across the Nafion, ICP is initiated to preconcentrate the biomolecules in the paper channel. Departing from previous paper-based preconcentrators, we maintain steady lateral fluid flow with the separated Nafion layer; as a result, fluorescent dyes and proteins (FITC-albumin and bovine serum albumin) are continuously delivered to the preconcentration zone, achieving high preconcentration performance up to 1000-fold. In addition, we demonstrate that the Nafion-patterned tape can be integrated with various geometries (multiplexed preconcentrator) and platforms (string and polymer microfluidic channel). This work would facilitate integration of various ICP devices, including preconcentrators, pH/concentration modulators, and micro mixers, with steady lateral flows in paper-based platforms.

  3. Sputtering effect of low-energy ions on biological target: The analysis of sputtering product of urea and capsaicin

    International Nuclear Information System (INIS)

    Zhang, Lili; Xu, Xue; Wu, Yuejin

    2013-01-01

    Sputtering is a process whereby atoms are ejected from a solid target material due to bombardment of the target by energetic particles. Recent years, ion implantation was successfully applied to biological research based on the fragments sputtering and form open paths in cell structure caused by ion sputtering. In this study, we focused on urea and chilli pepper pericarp samples implanted with N + and Ar + ions. To investigate the sputtering effect, we designed a collecting unit containing a disk sample and a glass pipe. The urea content and capsaicin content recovered from glass pipes were adopted to represent the sputtering product. The result of urea showed that the sputtering effect is positively correlated with the ion energy and dose, also affected by the ion type. The result of capsaicin was different from that of urea at 20 keV and possibly due to biological complex composition and structure. Therefore the sputtering yield depended on both the parameters of incident ions and the state of target materials. The sputtering yield of urea was also simulated by computational method achieved through the TRIM program. The trajectories of primary and recoiled atoms were calculated on the basis of the binary collision approximation using Monte Carlo method. The experimental results were much higher than the calculated results. The possible explanation is that in the physical model the target were assumed as a disordered lattice and independent atoms, which is much less complicated than that of the biological models

  4. TH-A-19A-05: Modeling Physics Properties and Biologic Effects Induced by Proton and Helium Ions

    Energy Technology Data Exchange (ETDEWEB)

    Taleei, R; Titt, U; Peeler, C; Guan, F; Mirkovic, D; Grosshans, D; Mohan, R [UT MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-15

    Purpose: Currently, proton and carbon ions are used for cancer treatment. More recently, other light ions including helium ions have shown interesting physical and biological properties. The purpose of this work is to study the biological and physical properties of helium ions (He-3) in comparison to protons. Methods: Monte Carlo simulations with FLUKA, GEANT4 and MCNPX were used to calculate proton and He-3 dose distributions in water phantoms. The energy spectra of proton and He-3 beams were calculated with high resolution for use in biological models. The repair-misrepairfixation (RMF) model was subsequently used to calculate the RBE. Results: The proton Bragg curve calculations show good agreement between the three general purpose Monte Carlo codes. In contrast, the He-3 Bragg curve calculations show disagreement (for the magnitude of the Bragg peak) between FLUKA and the other two Monte Carlo codes. The differences in the magnitude of the Bragg peak are mainly due to the discrepancy in the secondary fragmentation cross sections used by the codes. The RBE for V79 cell lines is about 0.96 and 0.98 at the entrance of proton and He-3 ions depth dose respectively. The RBE increases to 1.06 and 1.59 at the Bragg peak of proton and He-3 ions. The results demonstrated that LET, microdosimetric parameters (such as dose-mean lineal energy) and RBE are nearly constant along the plateau region of Bragg curve, while all parameters increase within the Bragg peak and at the distal edge for both proton and He-3 ions. Conclusion: The Monte Carlo codes should revise the fragmentation cross sections to more accurately simulate the physical properties of He-3 ions. The increase in RBE for He-3 ions is higher than for proton beams at the Bragg peak.

  5. Dynamics from seconds to hours in Hodgkin-Huxley model with time-dependent ion concentrations and buffer reservoirs.

    Directory of Open Access Journals (Sweden)

    Niklas Hübel

    2014-12-01

    Full Text Available The classical Hodgkin-Huxley (HH model neglects the time-dependence of ion concentrations in spiking dynamics. The dynamics is therefore limited to a time scale of milliseconds, which is determined by the membrane capacitance multiplied by the resistance of the ion channels, and by the gating time constants. We study slow dynamics in an extended HH framework that includes time-dependent ion concentrations, pumps, and buffers. Fluxes across the neuronal membrane change intra- and extracellular ion concentrations, whereby the latter can also change through contact to reservoirs in the surroundings. Ion gain and loss of the system is identified as a bifurcation parameter whose essential importance was not realized in earlier studies. Our systematic study of the bifurcation structure and thus the phase space structure helps to understand activation and inhibition of a new excitability in ion homeostasis which emerges in such extended models. Also modulatory mechanisms that regulate the spiking rate can be explained by bifurcations. The dynamics on three distinct slow times scales is determined by the cell volume-to-surface-area ratio and the membrane permeability (seconds, the buffer time constants (tens of seconds, and the slower backward buffering (minutes to hours. The modulatory dynamics and the newly emerging excitable dynamics corresponds to pathological conditions observed in epileptiform burst activity, and spreading depression in migraine aura and stroke, respectively.

  6. Dynamics from seconds to hours in Hodgkin-Huxley model with time-dependent ion concentrations and buffer reservoirs.

    Science.gov (United States)

    Hübel, Niklas; Dahlem, Markus A

    2014-12-01

    The classical Hodgkin-Huxley (HH) model neglects the time-dependence of ion concentrations in spiking dynamics. The dynamics is therefore limited to a time scale of milliseconds, which is determined by the membrane capacitance multiplied by the resistance of the ion channels, and by the gating time constants. We study slow dynamics in an extended HH framework that includes time-dependent ion concentrations, pumps, and buffers. Fluxes across the neuronal membrane change intra- and extracellular ion concentrations, whereby the latter can also change through contact to reservoirs in the surroundings. Ion gain and loss of the system is identified as a bifurcation parameter whose essential importance was not realized in earlier studies. Our systematic study of the bifurcation structure and thus the phase space structure helps to understand activation and inhibition of a new excitability in ion homeostasis which emerges in such extended models. Also modulatory mechanisms that regulate the spiking rate can be explained by bifurcations. The dynamics on three distinct slow times scales is determined by the cell volume-to-surface-area ratio and the membrane permeability (seconds), the buffer time constants (tens of seconds), and the slower backward buffering (minutes to hours). The modulatory dynamics and the newly emerging excitable dynamics corresponds to pathological conditions observed in epileptiform burst activity, and spreading depression in migraine aura and stroke, respectively.

  7. Heavy ion radiation biology research facility and ongoing activities at the Inter-University Accelerator Centre, New Delhi

    International Nuclear Information System (INIS)

    Sarma, Asitikantha

    2014-01-01

    Heavy Ion Radiation Biology is an interdisciplinary science involving use of charged particle accelerator in the study of molecular biology. It is the study of the interaction of a beam of swift heavy ions with a biological system. In contrast to the sparsely ionizing photon or electron radiation, the high velocity charged heavy ions leave a track of densely populated ionization sites resulting in clustered DNA damage. The growing interest in this field encompasses the studies in gene expression, mechanisms of cell death, DNA damage and repair, signal transduction etc. induced because of this unique assault on the genetic material. IUAC radiation biology programme is focused on the in-vitro studies of different effects of heavy ion irradiation on eukaryotic cells. The facility provides a laboratory for pre and post irradiation treatment of samples. The irradiation system called ASPIRE (Automatic Sample Positioning for Irradiation in Radiation Biology Experiments) is installed at the dedicated Radiation Biology Beam line. It produces a nearly uniform flux distribution over a irradiation field of 40 mm diameter. The particle doses can be preselected and repeated within inherent statistical accuracy. The particle energy can also be measured. The facility is at present utilized by the University researchers of India. A few results obtained by the investigators would be presented. The outcome of the research in heavy ion radiation biology would be of immense use in augmenting the efficacy of Hadron therapy of cancer. The results would also contribute to the field of space radiation protection. It would also help in understanding the phenomena subsequent to complex DNA damage. (author)

  8. How carbo-benzenes fit molecules in their inner core as do biologic ion carriers?

    KAUST Repository

    Turias, Francesc

    2015-09-25

    The present computational study complements experimental efforts to describe and characterize carbo-benzene derivatives as paradigms of aromatic carbo-mers. A long-lasting issue has been the possibility of the π-electron crown of the C18 carbo-benzene ring to fit metals or any chemical agents in its core. A systematic screening of candidate inclusion complexes was carried out by density functional theory calculations. Mayer bond order, aromaticity indices, and energy decomposition analyses complete the understanding of the strength of the host-guest interaction. The change in steric and electronic properties induced by the guest agent is investigated by means of steric maps. Substitution of H atoms at the carbo-benzene periphery by electron-withdrawing or electron-donating groups is shown to have a determining influence on the stability of the inclusion complex ions: while electronegative substituents enhance the recognition of cations, electropositive substituents do the same for anions. The results confirm the experimental failure hitherto to evidence a carbo-benzene complex. Nevertheless, the affinity of carbo-benzene for the potassium cation appears promising for the design of planar hydrocarbon analogues of biologic ion carriers. © 2015 Springer Science+Business Media New York.

  9. Biological effects of ion implantation on processing tomato and eggplant seed

    International Nuclear Information System (INIS)

    Mao Peihong; Zeng Xianxian; Jin Xiang

    2004-01-01

    The seed of processing tomato '87-5' (Lycopersicon esculentum Mill) were implanted by the low energy nitrogen ion (N + ) with 6 different doses. The rate of emergence was little reduced in M1 generation, but the fruiting number per plant was increased and it's maturing earlier 20 days than the control. The precocity, disease resistance and stronger growth vigor were shown in M2 generation. Experimental results of two years showed that, according to synthetic analysis in factors such as precocity, disease resistance, high yield and quality, the N + dose of 6 x 10 16 cm -2 (60 times of pulse) for tomato seed '87-5' had been proved to have notable biological effects on M1 and M2 generation. The seed of eggplant 'Wuyeqie' (Solanum melongena L.) was also implanted by the low energy nitrogen ion (N + ) with 2 different doses. Multi-vertical channel fruits were obtained in variable M1 generation, which liked the pomelo without peel. The seed of these variable eggplants was taken and planted in the next year. The meaningful variable fruits, the characters of disease-resistance, purple-peel, small-navel, lantern-form, large-scale, etc. were obtained in beneficial M2 generation. The biggest single-fruit weight reached 1.53 kg, providing valuable germplasm resource for breeding. (authors)

  10. Biological response to radiation. Studies of model organism, C. elegans, with micro-ion beam

    International Nuclear Information System (INIS)

    Higashitani, Atsushi

    2006-01-01

    Described are mainly author's studies on radiation response and its biological significance in a nematode, C. elegans, particularly focusing its germ cells. The model organism is bisexual and the mature one is suitable to observe the development, differentiation and concomitant chromosome dynamics of male and female germ cells, and accordingly, the responses occurring in those cells at different stages post irradiation of the whole worm. Authors have shown in the organism irradiated by 100 Gy X-ray that pachytene cells in meiosis have high radio-resistance due to their increased expression of enzymes related with homologous recombination. They have also presented the apoptotic cascade in germ cells triggered by radiation by comparison of wild type and ab1-1-gene-deleted worms. Micro-beam of 12 C 5+ ion in Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) has been used to irradiate the body parts of the worm to study the bystander effects, which has revealed that germ cells are shielded from the effect in the worm. It is thought important to use the micro-beam, with which the irradiation area can be precisely controllable, for studying the bystander effect in a body of higher animals like a mouse as well as in worm somatic cells. (T.I.)

  11. How carbo-benzenes fit molecules in their inner core as do biologic ion carriers?

    KAUST Repository

    Turias, Francesc; Poater, Jordi; Chauvin, Remi; Poater, Albert

    2015-01-01

    The present computational study complements experimental efforts to describe and characterize carbo-benzene derivatives as paradigms of aromatic carbo-mers. A long-lasting issue has been the possibility of the π-electron crown of the C18 carbo-benzene ring to fit metals or any chemical agents in its core. A systematic screening of candidate inclusion complexes was carried out by density functional theory calculations. Mayer bond order, aromaticity indices, and energy decomposition analyses complete the understanding of the strength of the host-guest interaction. The change in steric and electronic properties induced by the guest agent is investigated by means of steric maps. Substitution of H atoms at the carbo-benzene periphery by electron-withdrawing or electron-donating groups is shown to have a determining influence on the stability of the inclusion complex ions: while electronegative substituents enhance the recognition of cations, electropositive substituents do the same for anions. The results confirm the experimental failure hitherto to evidence a carbo-benzene complex. Nevertheless, the affinity of carbo-benzene for the potassium cation appears promising for the design of planar hydrocarbon analogues of biologic ion carriers. © 2015 Springer Science+Business Media New York.

  12. Decomposing the effects of ocean warming on chlorophyll a concentrations into physically and biologically driven contributions

    International Nuclear Information System (INIS)

    Olonscheck, D; Hofmann, M; Schellnhuber, H J; Worm, B

    2013-01-01

    Recently compiled observational data suggest a substantial decline in the global median chlorophyll a concentration over the 20th century, a trend that appears to be linked to ocean warming. Several modelling studies have considered changes in the ocean’s physical structure as a possible cause, while experimental work supports a biological mechanism, namely an observed increase in zooplankton grazing rate that outpaces phytoplankton production at higher temperatures. Here, we present transient simulations derived from a coupled ocean general circulation and carbon cycle model forced by atmospheric fields under unabated anthropogenic global warming (IPCC SRES A1FI scenario). The simulations account for both physical and biological mechanisms, and can reproduce about one quarter of the observed chlorophyll a decline during the 20th century, when using realistically parameterized temperature sensitivity of zooplankton metabolism (Q 10 between 2 and 4) and phytoplankton growth (Q 10 ∼ 1.9). Therefore, we have employed and re-calibrated the standard ecosystem model which assumes a lower temperature sensitivity of zooplankton grazing (Q 10 = 1.1049) by re-scaling phytoplankton growth rates and zooplankton grazing rates. Our model projects a global chlorophyll a decline of >50% by the end of the 21st century. While phytoplankton abundance and chlorophyll a experience pronounced negative effects, primary production and zooplankton concentrations are less sensitive to ocean warming. Although changes in physical structure play an important role, much of the simulated change in chlorophyll a and productivity is related to the uneven temperature sensitivity of the marine ecosystem. (letter)

  13. Effect of electrolytes concentration on recovery of cesium from AMP-PAN by Electrodialysis-Ion Exchange (EDIX)

    International Nuclear Information System (INIS)

    Mahendra, Ch.; Rajan, K.K.; SatyaSai, P.M.; Anand Babu, C.

    2014-01-01

    Cesium from the simulated acidic waste solution was separated using Ammonium Molybdophosphate (AMP) - Polyacrylonitrile (PAN) ion exchange resin in column operations. Electrodialysis - Ion exchange (EDIX) has been tried for the recovery of cesium from the AMP-PAN which was saturated with cesium. The electrodialysis setup consists of three compartments; cesium loaded AMP-PAN is placed in the middle compartment and is separated from the anode and cathode compartments by cation exchange membranes. Ammonium sulphate was used as anolyte and HNO 3 as catholyte. 0.1N HNO 3 was circulated in the middle compartment containing AMP-PAN to keep the resin in acidic form. On application of potential, the ammonium ions from the anode compartment migrate towards cathode through the middle compartment where they exchange with cesium ions on the resin and the exchanged cesium ions migrate towards cathode to get concentrated. Some part of cesium is recovered in the middle compartment due to convection. Cesium recovery from the AMP-PAN in the electrodialysis setup was studied at different anolyte and catholyte concentrations. All the experiments were carried out at constant current density of 40 mA/cm 2 for 15h. It was found that more than 50% of cesium recovery was observed for all the experiments studied and recovery percentage increased with increasing the anolyte concentration. It was observed that the electrolytes concentration affects the voltage drop across the cell

  14. Radial dependence of biological response of spores of Bacillus subtilis around tracks of heavy ions

    International Nuclear Information System (INIS)

    Facius, R.; Buecker, H.; Reitz, G.; Schaefer, M.

    1978-01-01

    Results on the biological action of heavy cosmic particles from the Biostack I and II experiments had been reported at the two preceeding symposia on microdosimetry. Analysis of these results with respect to spores of Bacillus subtilis indicated that the range of inactivation by a single heavy ion extended to larger impact parameters than to be expected from delta-ray dose only. Improved experimental techniques, as described at the last symposium, were successfully applied for the evaluation of the latest Biostack III experiment during the Apollo-Soyuz Test Project (ASTP). These techniques allowed the determination of the impact parameters with an accuracy of down to +-0.2 μm, which is well below the size of a spore. Results of the ASTP experiment will be presented concerning the physical composition of the radiation field and the biological response of the spores in dependence on the impact parameter. These results confirm the previous findings insofar as inactivation of spores reaches out to about 4-5 μm. This finding will be discussed together with results from other Biostack test objects. Comparative accelerator experiments with Bacillus subtilis spores are presented in an additional paper

  15. Parametrics for Molecular Deuterium Concentrations in the Source Region of the UW-IEC Device Using an Ion Acoustic Wave Diagnostic

    Science.gov (United States)

    Boris, D. R.; Emmert, G. A.

    2007-11-01

    The ion source region of the UW-Inertial Electrostatic Confinement device is comprised of a filament assisted DC discharge plasma that exists between the wall of the IEC vacuum chamber and the grounded spherical steel grid that makes up the anode of the IEC device. A 0-dimensional rate equation calculation of the molecular deuterium ion species concentration has been applied utilizing varying primary electron energy, and neutral gas pressure. By propagating ion acoustic waves in the source region of the IEC device the concentrations of molecular deuterium ion species have been determined for these varying plasma conditions, and high D3^+ concentrations have been verified. This was done by utilizing the multi-species ion acoustic wave dispersion relation, which relates the phase speed of the multi-species ion acoustic wave, vph, to the sum in quadrature of the concentration weighted ion acoustic sound speeds of the individual ion species.

  16. Biological concentration of radionuclides in plants and animals after Chernobyl catastrophe

    International Nuclear Information System (INIS)

    Nakajima, Hiroo; Ryo, Haruko; Nomura, Taisei; Yamaguchi, Yoshiaki; Saito, Tadashi; Yeliseeva, K.G.; Piskunov, V.S.; Krupnova, E.V.; Voitovich, A.M.

    2000-01-01

    The 137 Cs radioactivity and its distribution in plants (trees, mushrooms, berries, duckweed, and etc.) and animals (insects, mice, fish, and etc.) were measured in contaminated areas of southern Belarus, which was highly polluted by radionuclides as a result of the Chernobyl catastrophe in Ukraine in 1986. Gamma spectrometry of 137 Cs was carried out, and a computer graphic imaging analysis was performed to visualize the distribution of radioactive nuclides in the organisms. The specimen was placed on the imaging plate, the plate was exposed for 20 h. High 137 Cs radioactivity was detected in both the animals (mice, moles, dragonflies, grasshoppers, and fish) and the plants (pine trees, oak leaves, mushrooms, berries, duckweed). The 137 Cs radioactivity in the organisms was proportional to the radioactivity in the soil. Assessment of its distribution showed that 137 Cs was highly concentrated in muscle, but there were no substantial differences in 137 Cs radioactivity according to organ or species. Computer graphic imaging analysis clearly revealed non-uniform distribution of 137 Cs radioactivity in the animals and plants. In pine trees, the highest level of radioactivity was found in the bark, and it decreased toward the center of the tree. In conclusion, the authors suggest that self-cleaning of the soil will require a very long time and that the biological concentrations will persist and increase in higher animals for a long time, resulting in accumulation of both external and internal radiation exposure in animals. (K.H.)

  17. Determination of sup 18 O concentrations in microsamples of biological fluids

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, D D [Australian Nuclear Science and Technology Organisation (ANSTO), Menai (Australia); Bradshaw, S D; Bradshaw, F J [University of Western Australia, Perth (Australia). Dept. of Zoology; Katsaros, A [Australian Inst. of Nuclear Science and Engineering (AINSE), Menai (Australia)

    1990-04-01

    The {sup 18}O(p, {alpha}){sup 15}N reaction has been developed for the analysis of microsamples of biological fluids containing {sup 18}O-enriched water. Samples as small as 50 {mu}l have been used. Well characterized Ta{sub 2}O{sub 5} targets were prepared from these fluids and irradiated with several hundred nA of protons from the 3 MV Van de Graaff at Lucas Heights. The broad (47 keV) 846 kV resonance in this reaction was used to measure {sup 18}O concentrations down to natural backgrounds (0.2 at.%) in a few minutes of accelerator running time. Concentrations of {sup 18}O from 0 to 5 at.% were measured in body fluids in small Australian lizards directly after doping with {sup 18}O-enriched water and then again after several days of roaming around in their natural desert environments. The changes in these levels were related to the metabolic rates of these animals. (orig.).

  18. Biological treatment and toxicity of low concentrations of oily wastewater (bilgewater)

    Energy Technology Data Exchange (ETDEWEB)

    Stamper, D.M. [NAVSEA Carderrock Div., West Bethesda, MD (United States). Biological Sciences Group; Montgomery, M.T. [Naval Research Laboratory, Washington, DC (United States). Marine Biochemistry Section

    2008-08-15

    Oily waste water from ships occurs when materials leak, spill, or are washed off the decks and drain into the bilge compartments of ships. The wastes include diesel fuel, coolants, and engine, transmission, and hydraulic oils. Treatments for oily waste water in the United States Navy are based on a combination of density separation and ceramic membrane ultrafiltration techniques, which may not meet planned regulations that will require lower levels of oil pollutants. This study tested the biodegradability and toxicity of low concentrations of oily waste water in order to establish the feasibility of using a combined shipboard oily and sanitary waste water treatment system. The toxic effects of diesel fuel and other components of the waste water were also tested. The study showed that diluting the oily effluent with the sanitary waste stream resulted in waste water with low enough oil content to meet the anticipated changes in waste water regulations. The study also showed that the low concentrations of waste water were catabolized in the presence of the sanitary waste stream. A modified PolyTox assay was used to test the waste water samples. Results of the study showed that heterotrophic bacterial production rates did not show any toxic effects. The addition of detergent in the samples had no impact on toxicity levels. It was concluded that combining oil and sanitary waste water in a single biological treatment system is a feasible option for ensuring the future regulations are met. 37 refs., 2 tabs., 4 figs.

  19. [On-line analysis and mass concentration characters of the alkali metal ions of PM10 in Beijing].

    Science.gov (United States)

    Zhang, Kai; Wang, Yue-Si; Wen, Tian-Xue; Liu, Guang-Ren; Hu, Bo; Zhao, Ya-Nan

    2008-01-01

    The mass concentration characters and the sources of water-soluble alkali metal ions in PM10 in 2004 and 2005 in Beijing were analyzed by using the system of rapid collection of particles. The result showed that the average concentration of Na+, K+, Mg2+ and Ca2+ was 0.5-1.4, 0.5-2.5, 0.1-0.5 and 0.6-5.8 microg/m3, respectively. The highest and lowest concentration appeared in different seasons for the alkali metal ions, which was related to the quality and source. The concentration of alkali metal ions was no difference between the heating period and no heating period, which meant the heating was not the main source. Sea salt and soil were the important sources of Na+. The source of K+ came from biomass burning and vegetation. Soil was the large source of Mg2+ and Ca2+. The alkali metal ions appeared different daily variation in different seasons. Precipitation could decrease the concentration of Na+, K+, Mg2+ and Ca2+, which was 10%-70%, 20%-80%, 10%-77%, 5%-80% respectively.

  20. Measurement of the Cupric Ion Concentration in the Simulation of the Focusing effect

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Je-Young; Hong, Seung-Hyun; Chung, Bum-Jin [Kyung Hee University, Seoul (Korea, Republic of)

    2015-10-15

    The Rayleigh number and aspect ratio (H/R) ranged from 8.49x10{sup 7} to 5.43x10{sup 9} and 0.135 to 0.541 respectively. In order to simulate the different temperature conditions of top and side wall, an electrical resistance was attached to the top wall so that it is mimics hotter wall condition. The heat transfer experiments were replaced by mass transfer experiments based on the heat and mass transfer analogy concept. A sulfuric acid-copper sulfate (H{sub 2}SO{sub 4} - CuSO{sub 4}) electroplating system was adopted as the mass transfer system. The experimental study was performed to investigate the focusing effect according to the different temperature conditions and the height in metallic layer. This work devised a method to simulate the different cooling conditions of the top and side walls and adopted an electrical resistance to the top plate. The electrical resistance was varied for the height of side wall. The experimental results agreed well with the Rayleigh-Benard convection correlations of Dropkin and Somerscales and Globe and Dropkin. The heat transfer was enhanced by increasing the electrical resistance and decreasing the height of side wall. The focusing effect at the side wall was improved by the hotter top wall condition. In order to overcome the limitations of mass transfer, this work tried to measure the cupric ion concentration. The methods of concentration measurement are RGB, Brightness, ICP and PIV. The key of RGB, Brightness and PIV method is the clear images of the thermal boundary layer.

  1. Multisite Ion Model in Concentrated Solutions of Divalent Cations (MgCl2 and CaCl2): Osmotic Pressure Calculations

    Science.gov (United States)

    2015-01-01

    Accurate force field parameters for ions are essential for meaningful simulation studies of proteins and nucleic acids. Currently accepted models of ions, especially for divalent ions, do not necessarily reproduce the right physiological behavior of Ca2+ and Mg2+ ions. Saxena and Sept (J. Chem. Theor. Comput.2013, 9, 3538–3542) described a model, called the multisite-ion model, where instead of treating the ions as an isolated sphere, the charge was split into multiple sites with partial charge. This model provided accurate inner shell coordination of the ion with biomolecules and predicted better free energies for proteins and nucleic acids. Here, we expand and refine the multisite model to describe the behavior of divalent ions in concentrated MgCl2 and CaCl2 electrolyte solutions, eliminating the unusual ion–ion pairing and clustering of ions which occurred in the original model. We calibrate and improve the parameters of the multisite model by matching the osmotic pressure of concentrated solutions of MgCl2 to the experimental values and then use these parameters to test the behavior of CaCl2 solutions. We find that the concentrated solutions of both divalent ions exhibit the experimentally observed behavior with correct osmotic pressure, the presence of solvent separated ion pairs instead of direct ion pairs, and no aggregation of ions. The improved multisite model for (Mg2+ and Ca2+) can be used in classical simulations of biomolecules at physiologically relevant salt concentrations. PMID:25482831

  2. Concentrations of ions and metals in blood of amateur and elite runners using NAA

    International Nuclear Information System (INIS)

    Kovacs, L.; Zamboni, C.B.; Nunes, L.A.S.; Lourenco, T.F.; Macedo, D.V.

    2013-01-01

    Intense physical training is known to be associated with increased mineral losses through sweating (during the exercise) and also through urine (after the exercise). Nowadays physical training is recognized for adapting or damaging the muscles, depending on the intensity and duration of the effort, provoking detectable metabolic alterations in blood, mainly in the content of some ions. In this study Br, Ca, Cl, K, Mg, Na and S levels were investigated in blood of Brazilian athletes that were submitted to constant physical exercise, at Laboratorio de Bioquimica do Exercicio (LABEX/UNICAMP) using Neutron Activation Analyses technique (NAA). The blood samples were collected from male amateurs and elite athletes, ranging from 18 to 36 years old. The blood samples were irradiated in the nuclear reactor (IEA-R1, 3-4.5 MW, pool type) at IPEN/Sao Paulo-Brazil. The concentrations data were compared with the control group (subjects of same gender and age but not involved with physical activities). These data can be useful for evaluating the performance of endurance athletes during the period of competition preparation as well as to propose new evaluation of protocols not yet reported. (author)

  3. Alternative solidification techniques for radioactive ion exchange resins and liquid concentrates

    International Nuclear Information System (INIS)

    Thegerstroem, C.

    1980-01-01

    Methods, that are used or are under development for solidification of radioactive ion exchange resins or liquid concentrates, utilize normally cement, bitumen or some polymere as matrix material. This report contains a review and a description of these solidification processes and their products, especially of relatively new techniques that are under development in different countries. It is possible that solidification in thermosetting resins will be more used in the future, especially when product quality requirements are high (for instance when solidifying medium level resins) or when special waste categories has to be solidified. However it is not probable that thermosetting resins will be extensively used in a broad application as matrix material. In that case the methods are to complicated and expensive compared to, for instance, solidification in concrete. Systems for incorporation in polyesteremulsions (Dow-process) have a potential as they are quite simple and can accept a large variation of liquid wastes. Some methods in an early stage of development (for instance Inert Carrier Radwaste Process) will have to be tested in active application before they can be further evaluated. (author)

  4. Ion-pair extraction of [3H]stobadine from biological fluids

    International Nuclear Information System (INIS)

    Scasnar, V.

    1998-01-01

    A simple and specific radiometric assay was developed for the determination of stobadine, a cardioprotective drug, in the serum of experimental animals. The assay is based on a single extraction step of the radioactively labeled drug from serum into the benzene solution of dicarbolide of cobalt followed by quantitation of the extracted radioactivity by using liquid scintillation counting. The extraction mechanism involves the ion-pair formation between the protonized molecule of stobadine and the hydrophobic, negatively charged molecule of dicarbolide of cobalt. The extraction yield of stobadine from 1 ml of serum was 95% in the concentration range from 1 to 6000 ng/ml. The co-extraction of metabolites was less than 5%. The method was applied to the determination of stobadine in serum of dogs and the data obtained were in a good agreement with those obtained by high performance liquid chromatography. (author)

  5. Seasonal dynamics of nitrate and ammonium ion concentrations in soil solutions collected using MacroRhizon suction cups.

    Science.gov (United States)

    Kabala, Cezary; Karczewska, Anna; Gałka, Bernard; Cuske, Mateusz; Sowiński, Józef

    2017-07-01

    The aims of the study were to analyse the concentration of nitrate and ammonium ions in soil solutions obtained using MacroRhizon miniaturized composite suction cups under field conditions and to determine potential nitrogen leaching from soil fertilized with three types of fertilizers (standard urea, slow-release urea, and ammonium nitrate) at the doses of 90 and 180 kg ha -1 , applied once or divided into two rates. During a 3-year growing experiment with sugar sorghum, the concentration of nitrate and ammonium ions in soil solutions was the highest with standard urea fertilization and the lowest in variants fertilized with slow-release urea for most of the months of the growing season. Higher concentrations of both nitrogen forms were noted at the fertilizer dose of 180 kg ha -1 . One-time fertilization, at both doses, resulted in higher nitrate concentrations in June and July, while dividing the dose into two rates resulted in higher nitrate concentrations between August and November. The highest potential for nitrate leaching during the growing season was in July. The tests confirmed that the miniaturized suction cups MacroRhizon are highly useful for routine monitoring the concentration of nitrate and ammonium ions in soil solutions under field conditions.

  6. Sensing local pH and ion concentration at graphene electrode surfaces using in situ Raman spectroscopy.

    Science.gov (United States)

    Shi, Haotian; Poudel, Nirakar; Hou, Bingya; Shen, Lang; Chen, Jihan; Benderskii, Alexander V; Cronin, Stephen B

    2018-02-01

    We report a novel approach to probe the local ion concentration at graphene/water interfaces using in situ Raman spectroscopy. Here, the upshifts observed in the G band Raman mode under applied electrochemical potentials are used to determine the charge density in the graphene sheet. For voltages up to ±0.8 V vs. NHE, we observe substantial upshifts in the G band Raman mode by as much as 19 cm -1 , which corresponds to electron and hole carrier densities of 1.4 × 10 13 cm -2 and Fermi energy shifts of ±430 meV. The charge density in the graphene electrode is also measured independently using the capacitance-voltage characteristics (i.e., Q = CV), and is found to be consistent with those measured by Raman spectroscopy. From charge neutrality requirements, the ion concentration in solution per unit area must be equal and opposite to the charge density in the graphene electrode. Based on these charge densities, we estimate the local ion concentration as a function of electrochemical potential in both pure DI water and 1 M KCl solutions, which span a pH range from 3.8 to 10.4 for pure DI water and net ion concentrations of ±0.7 mol L -1 for KCl under these applied voltages.

  7. Structural and Dynamical Properties of Alkaline Earth Metal Halides in Supercritical Water: Effect of Ion Size and Concentration.

    Science.gov (United States)

    Keshri, Sonanki; Tembe, B L

    2017-11-22

    Constant temperature-constant pressure molecular dynamics simulations have been performed for aqueous alkaline earth metal chloride [M 2+ -Cl - (M = Mg, Ca, Sr, and Ba)] solutions over a wide range of concentrations (0.27-5.55 m) in supercritical (SC) and ambient conditions to investigate their structural and dynamical properties. A strong influence of the salt concentration is observed on the ion-ion pair correlation functions in both ambient and SC conditions. In SC conditions, significant clustering is observed in the 0.27 m solution, whereas the reverse situation is observed at room temperature and this is also supported by the residence times of the clusters. The concentration and ion size (cation size) seem to have opposite effects on the average number of hydrogen bonds. The simulation results show that the self-diffusion coefficients of water, cations, and the chloride ion increase with increasing temperature, whereas they decrease with increasing salt concentration. The cluster size distribution shows a strong density dependence in both ambient and SC conditions. In SC conditions, cluster sizes display a near-Gaussian distribution, whereas the distribution decays monotonically in ambient conditions.

  8. Biological effects of tritiated water in low concentration of human lymphocyte chromosome

    International Nuclear Information System (INIS)

    Tanaka, K.; Kamada, N.; Sawaeda, S.

    1992-01-01

    This study was undertaken to investigate the dose-response relationship of tritiated water (HTO) for chromosome aberration in the human lymphocytes, at low dose in vitro exposure ranging from 0.1-1 Gy. The Relative Biological Effectiveness values of HTO with respect to 60 Co gamma ray at a dose rate of 2 cGy/min(15 mCi/ml), at low dose range for the induction of dicentric and centric ring chromosomes were 2.7 in lymphocytes. Also lymphocytes were chronically exposed to HTO for 67 to 80 hrs at different lower dose rates (0.5 and 0.02 cGy/min). There was a 77% decrease in the yields of dicentrics and centric rings, at the dose rate of 0.02cGy/min of HTO, presenting a clear dose rate effect of HTO. The RBE value of HTO relative to 137 Cs gamma ray was 2.0 at the dose rate of 0.02cGy/min(0.15mCi/ml). This suggests that a higher dose rate of HTO exposure has a higher risk and a decrease of RBE value at low dose rate. These results provide useful information for the assessment of health risks in humans specially exposed to low concentration of HTO. (author). 6 refs., 2 figs

  9. Concentrations, input prediction and probabilistic biological risk assessment of polycyclic aromatic hydrocarbons (PAHs) along Gujarat coastline.

    Science.gov (United States)

    Gosai, Haren B; Sachaniya, Bhumi K; Dudhagara, Dushyant R; Rajpara, Rahul K; Dave, Bharti P

    2018-04-01

    A comprehensive investigation was conducted in order to assess the levels of PAHs, their input prediction and potential risks to bacterial abundance and human health along Gujarat coastline. A total of 40 sediment samples were collected at quarterly intervals within a year from two contaminated sites-Alang-Sosiya Shipbreaking Yard (ASSBRY) and Navlakhi Port (NAV), situated at Gulf of Khambhat and Gulf of Kutch, respectively. The concentration of ΣPAHs ranged from 408.00 to 54240.45 ng g -1  dw, indicating heavy pollution of PAHs at both the contaminated sites. Furthermore, isomeric ratios and principal component analysis have revealed that inputs of PAHs at both contaminated sites were mixed-pyrogenic and petrogenic. Pearson co-relation test and regression analysis have disclosed Nap, Acel and Phe as major predictors for bacterial abundance at both contaminated sites. Significantly, cancer risk assessment of the PAHs has been exercised based on incremental lifetime cancer risks. Overall, index of cancer risk of PAHs for ASSBRY and NAV ranged from 4.11 × 10 -6 -2.11 × 10 -5 and 9.08 × 10 -6 -4.50 × 10 -3 indicating higher cancer risk at NAV compared to ASSBRY. The present findings provide baseline information that may help in developing advanced bioremediation and bioleaching strategies to minimize biological risk.

  10. Influence of chloride ion concentration on the electrochemical corrosion behaviour of plasma electrolytic oxidation coated AM50 magnesium alloy

    International Nuclear Information System (INIS)

    Liang, J.; Srinivasan, P. Bala; Blawert, C.; Dietzel, W.

    2010-01-01

    The electrochemical degradation of a silicate- and a phosphate-based plasma electrolytic oxidation (PEO) coated AM50 magnesium alloy obtained using a pulsed DC power supply was investigated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) in NaCl solutions of different chloride ion concentrations viz., 0.01 M, 0.1 M, 0.5 M and 1 M. The surface of the PEO coated specimens after 50 h of immersion/EIS testing was examined by optical microscopy and scanning electron microscopy. The results showed that the corrosion deterioration of PEO coated magnesium alloy in NaCl solutions was significantly influenced by chloride ion concentration. The silicate-based coating was found to offer a superior corrosion resistance to the magnesium substrate than the phosphate-based coatings in lower chloride ion concentration NaCl solutions (0.01 M and 0.1 M NaCl). On the other hand both these PEO coatings were found to be highly susceptible to localized damage, and could not provide an effective corrosion protection to Mg alloy substrate in solutions containing higher chloride concentrations (0.5 M and 1 M). The extent of localized damage was observed to be more with increase in chloride concentration in both the cases.

  11. Application of the atomic absorption technical to available the concentration of silver ions incorporated in glass matrix by ionic exchange process

    International Nuclear Information System (INIS)

    Mendes, E.; Silva, K.F.; Teixeira, A.; Silva, L.; Paula, M.M.S.; Angioletto, E.; Riella, H.G.; Fiori, M. A.

    2009-01-01

    Ion specimens can be incorporated in glasses or natural clays by ionic exchange process with different concentrations dependent of matrix's type and of the ionic exchange parameters. In particular, the incorporation of silver ions presents high interest by its biocidal properties. A compound contending ion silver specimens presents bactericidal and fungicidal properties with effect proportional to ion concentration. This work presents results about application of the atomic absorption technical to determine the silver ion concentration incorporated in a glass matrix by ionic exchange process. The ionic exchange experiments were realized with different AgNO 3 concentration and constant temperature. After ionic exchange process, the glass samples were submitted to characterization by Energy Dispersive X-Ray Spectroscopy and Atomic Absorption Techniques. The comparative results between different techniques showed that atomic absorption technical is adequate to determine ion silver concentration incorporated in the glass matrix after ionic exchange process. (author)

  12. Application of ion mobility spectrometry for the determination of tramadol in biological samples

    Directory of Open Access Journals (Sweden)

    Ali Sheibani

    2014-12-01

    Full Text Available In this study, a simple and rapid ion mobility spectrometry (IMS method has been described for the determination of tramadol. The operating instrumental parameters that could influence IMS were investigated and optimized (temperature; injection: 220 and IMS cell: 190°C, flow rate; carrier: 300 and drift: 600 mL/minute, voltage; corona: 2300 and drift: 7000 V, pulse width: 100 μs. Under optimum conditions, the calibration curves were linear within two orders of magnitude with R2 ≥ 0.998 for the determination of tramadol in human plasma, saliva, serum, and urine samples. The limits of detection and the limits of quantitation were between 0.1 and 0.3 and 0.3 and 1 ng/mL, respectively. The relative standard deviations were between 7.5 and 8.8%. The recovery results (90–103.9% indicate that the proposed method can be applied for tramadol analysis in different biological samples.

  13. Study of biological effects of accelerated heavy ions irradiation on rices: Pt. 1

    International Nuclear Information System (INIS)

    Liu Zhensheng; Qiu Quanfa; Huang Wenzhong; Mei Mantong; Yang, T.C.H.

    1991-01-01

    The dried rice seeds were irradiated with accelerated 56 Fe and 40 Ar ion beams or 60 Co γ-rays at various doses. The irradiation effects on seeding growth as well as micronuclei and chronosome aberration induction were observed. The results indicated that the seeding height raduction, frequency of micronucleated cells and frequency of chromosome aberrations all appeared to dose dependent for these three types of rediation. The RBE value for seeding height reduction, determined at fifity percent of hight inhibition level, was found to be about 6.3, 1.9 and 1 for 56 Fe, 40 Ar and 60 Co γ-ray respectively. However, the RBE values for the frequency of micronucleated cells were about 11, 4 and 1 for 56 Fe and 40 Ar particles and 60 Co γ-ray. It appeared that the effectiveness of high LET radiation in inducing biological effects at the first generation was higler than that of low LET radiation, especially in inducing the micronuclei formation

  14. Carbon Heavy-ion Radiation Induced Biological effects on Oryza sativa L.

    Science.gov (United States)

    Zhang, Meng; Sun, Yeqing; Li, Xishan; Gong, Ning; Meng, Qingmei; Liu, Jiawei; Wang, Ting

    2016-07-01

    Large number of researches on rice after spaceflights indicated that rice was a favorable model organism to study biological effects induced by space radiation. The stimulative effect could often be found on rice seedlings after irradiation by low-dose energetic heavy-ion radiation. Spaceflight also could induce stimulative effect on kinds of seeds. To further understand the mechanism of low-dose radiation biological effects and the dose range, the germinated rice seeds which were irradiated by different doses of carbon heavy-ion (0, 0.02, 0.1, 0.2, 1, 2, 5, 10, 15 and 20Gy, LET=27.3keV/µm) were used as materials to study. By investigating the variation of rice phenotype under different doses, we found that 2Gy radiation dose was a dividing point of the phenotypic variation. Transmission electron microscopy was used to observe the variation of mitochondria, chloroplast, endoplasmic reticulum, ribosome and nucleus in mesophyll cell of rice apical meristem at 24 hours after radiation with different doses. The cells were not apparently physiologically damaged when the dose of radiation was less than 2Gy. The number of chloroplast did not change significantly, but the number of mitochondria was significantly increased, and gathered around in the chloroplast and endoplasmic reticulum; the obvious lesion of chloroplast and mitochondria were found at the mesophyll cells when radiation dose was higher than 2Gy. The mitochondria were swelling and appearing blurred crest. The chloroplast and mitochondrial mutation rate increased significantly (pmitochondrial was an important organelle involved in the antioxidative systems, its dysfunction could result in the increase of reactive oxygen species and lipid peroxidation. We found that the growth stimulation induced by low-dose radiation mainly occurred at three-leaf stage along with the increasing activity of antioxidase system and damages of lipid peroxidation. We also found that the relative expression of genes sdhb and aox1a

  15. The effect of different phosphate ion concentrations and ph of the phosphate buffer on lipase bioproduction by rhizopus oligosporus

    International Nuclear Information System (INIS)

    Haq, I.; Ali, S.; Awan, U.F.; Javed, W.; Mirza, S.

    2005-01-01

    In the present investigation, we report the effect of phosphate ion concentration and different ph of the phosphate buffer (as diluent) on lipase bioproduction by Rhizopus oligosporus. For this purpose, solid state fermentation was employed. Different agricultural by-products such as wheat bran, rice husk, almond meal, soybean meal and sunflower meal were used as substrate. The maximum lipase activity (72.60 U/g) was observed with the almond meal. Addition of phosphate ions (K/sub 2/HPO/sub 4/) influenced the lipase production. The ph of the phosphate buffer (7.0) was found to be effective for higher yield of lipase. (author)

  16. Selectivity improvement of positive photoionization ion mobility spectrometry for rapid detection of organophosphorus pesticides by switching dopant concentration.

    Science.gov (United States)

    Zhou, Qinghua; Li, Jia; Wang, Bin; Wang, Shuang; Li, Haiyang; Chen, Jinyuan

    2018-01-01

    Ion mobility spectrometry (IMS) opened a potential avenue for the rapid detection of organophosphorus pesticides (OPPs), though an improved selectivity of stand-alone IMS was still in high demand. In this study, a stand-alone positive photoionization ion mobility spectrometry (PP-IMS) apparatus was constructed for the rapid detection of OPPs with acetone as dopant. The photoionization of acetone molecules was induced by the ultraviolet irradiation to produce the reactant ions (Ac) 2 H + , which were employed to ionize the OPPs including fenthion, imidan, phosphamidon, dursban, dimethoate and isocarbophos via the proton transfer reaction. Due to the difference in proton affinity, the tested OPPs exhibited the different dopant-dependent manners. Based on this observation, the switching of dopant concentration was implemented to improve the selectivity of PP-IMS for OPPs detection. For instance, a mixture of fenthion, dursban and dimethoate was tested. By switching the concentration of doped acetone from 0.07 to 2.33 to 19.94mgL -1 , the ion peaks of fenthion and dursban were inhibited in succession, achieving the selective detection of dimethoate at last. In addition, another mixture of imidan and phosphamidon was initially detected by PP-IMS with a dose of 0.07mgL -1 acetone, indicating that their ion peaks were severely overlapped; when the concentration of doped acetone was switched to 19.94mgL -1 , the inhibition of imidan signals promised the accurate identification of phosphamidon in mixture. Finally, the PP-IMS in combination of switching dopant concentration was applied to detect the mixed fenthion, dursban and dimethoate in Chinese cabbage, demonstrating the applicability of proposed method to real samples. Copyright © 2017. Published by Elsevier B.V.

  17. Impact of environmental regulations on control of copper ion concentration in the DIII-D cooling water system

    International Nuclear Information System (INIS)

    Gootgeld, A.M.

    1993-10-01

    Tokamaks and industrial users are faced with the task of maintaining closed-loop, low conductivity, low impurity, cooling water systems. Operating these systems concentrates the impurities in the water requiring subsequent disposal. Environmental regulations are making this increasingly difficult. This paper will discuss the solution to the problem of removing and disposing of copper ions in the DIII-D low conductivity water system. Since the commissioning of the Doublet facility, the quality of the water in the 3000 gpm system that cools the DIII-D vacuum vessel coils, power supplies and auxiliary heating components has been controlled with mixed-bed ion exchangers. Low ion levels, particularly copper, are required to operate this equipment. In early 1992, the company that leases and regenerates DIII-D ion exchangers said they no longer can accept these resin beds for regeneration due to the level of copper ion on the resin. This change in policy, a change that has been adopted throughout their industry, was necessary to assure that the Metropolitan Sewerage System of the City of San Diego stays in compliance with State of California regulations and EPA-mandated national pretreatment standards and regulations. A cost effective solution was implemented which utilizes a reverse osmosis filtration system with the ion exchangers for make-up water. Levels of copper ion disposed to the sewer are in compliance with government standards. These measures have thus far proved effective in maintaining low conductivity and overall good quality cooling water. Specifically, this paper discusses DIII-D deionized cooling water quality requirements and an affective means to meet these requirements in order to be in compliance with government regulations for copper ion disposal. The problems discussed, the alternatives considered and the approach taken would be readily applicable to any deionized cooling water system containing copper where EPA standards and regulations are mandated

  18. [Relationship among the Oxygen Concentration, Reactive Oxygen Species and the Biological Characteristics of Mouse Bone Marrow Hematopoietic Stem Cells].

    Science.gov (United States)

    Ren, Si-Hua; He, Yu-Xin; Ma, Yi-Ran; Jin, Jing-Chun; Kang, Dan

    2016-02-01

    To investigate the effects of oxygen concentration and reactive oxygen species (ROS) on the biological characteristics of hematopoietic stem cells (HSC) and to analyzed the relationship among the oxygen concentration, ROS and the biological characteristics of mouse HSC through simulation of oxygen environment experienced by PB HSC during transplantation. The detection of reactive oxygen species (ROS), in vitro amplification, directional differentiation (BFU-E, CFU-GM, CFU-Mix), homing of adhesion molecules (CXCR4, CD44, VLA4, VLA5, P-selectin), migration rate, CFU-S of NOD/SCID mice irradiated with sublethal dose were performed to study the effect of oxgen concentration and reactive oxygen species on the biological characteristics of mouse BM-HSC and the relationship among them. The oxygen concentrations lower than normal oxygen concentration (especially hypoxic oxygen environment) could reduce ROS level and amplify more Lin(-) c-kit(+) Sca-1(+) BM HSC, which was more helpful to the growth of various colonies (BFU-E, CFU-GM, CFU-Mix) and to maintain the migratory ability of HSC, thus promoting CFU-S growth significantly after the transplantation of HSC in NOD/SCID mice irradiated by a sublethal dose. BM HSC exposed to oxygen environments of normal, inconstant oxygen level and strenuously thanging of oxygen concentration could result in higher level of ROS, at the same time, the above-mentioned features and functional indicators were relatively lower. The ROS levels of BM HSC in PB HSCT are closely related to the concentrations and stability of oxygen surrounding the cells. High oxygen concentration results in an high level of ROS, which is not helpful to maintain the biological characteristics of BM HSC. Before transplantation and in vitro amplification, the application of antioxidancs and constant oxygen level environments may be beneficial for transplantation of BMMSC.

  19. Paper-Based Analytical Device for Zinc Ion Quantification in Water Samples with Power-Free Analyte Concentration

    Directory of Open Access Journals (Sweden)

    Hiroko Kudo

    2017-04-01

    Full Text Available Insufficient sensitivity is a general issue of colorimetric paper-based analytical devices (PADs for trace analyte detection, such as metal ions, in environmental water. This paper demonstrates the colorimetric detection of zinc ions (Zn2+ on a paper-based analytical device with an integrated analyte concentration system. Concentration of Zn2+ ions from an enlarged sample volume (1 mL has been achieved with the aid of a colorimetric Zn2+ indicator (Zincon electrostatically immobilized onto a filter paper substrate in combination with highly water-absorbent materials. Analyte concentration as well as sample pretreatment, including pH adjustment and interferent masking, has been elaborated. The resulting device enables colorimetric quantification of Zn2+ in environmental water samples (tap water, river water from a single sample application. The achieved detection limit of 0.53 μM is a significant improvement over that of a commercial colorimetric Zn2+ test paper (9.7 μM, demonstrating the efficiency of the developed analyte concentration system not requiring any equipment.

  20. Handheld Device Adapted to Smartphone Cameras for the Measurement of Sodium Ion Concentrations at Saliva-Relevant Levels via Fluorescence

    Directory of Open Access Journals (Sweden)

    Michelle Lipowicz

    2015-06-01

    Full Text Available The use of saliva sampling as a minimally-invasive means for drug testing and monitoring physiology is a subject of great interest to researchers and clinicians. This study describes a new optical method based on non-axially symmetric focusing of light using an oblate spheroid sample chamber. The device is simple, lightweight, low cost and is easily attached to several different brands/models of smartphones (Apple, Samsung, HTC and Nokia for the measurement of sodium ion levels at physiologically-relevant saliva concentrations. The sample and fluorescent reagent solutions are placed in a specially-designed, lightweight device that excludes ambient light and concentrates 470-nm excitation light, from a low-power photodiode, within the sample through non-axially-symmetric refraction. The study found that smartphone cameras and post-image processing quantitated sodium ion concentration in water over the range of 0.5–10 mM, yielding best-fit regressions of the data that agree well with a data regression of microplate luminometer results. The data suggest that fluorescence can be used for the measurement of salivary sodium ion concentrations in low-resource or point-of-care settings. With further fluorescent assay testing, the device may find application in a variety of enzymatic or chemical assays.

  1. Full Monte Carlo-Based Biologic Treatment Plan Optimization System for Intensity Modulated Carbon Ion Therapy on Graphics Processing Unit.

    Science.gov (United States)

    Qin, Nan; Shen, Chenyang; Tsai, Min-Yu; Pinto, Marco; Tian, Zhen; Dedes, Georgios; Pompos, Arnold; Jiang, Steve B; Parodi, Katia; Jia, Xun

    2018-01-01

    One of the major benefits of carbon ion therapy is enhanced biological effectiveness at the Bragg peak region. For intensity modulated carbon ion therapy (IMCT), it is desirable to use Monte Carlo (MC) methods to compute the properties of each pencil beam spot for treatment planning, because of their accuracy in modeling physics processes and estimating biological effects. We previously developed goCMC, a graphics processing unit (GPU)-oriented MC engine for carbon ion therapy. The purpose of the present study was to build a biological treatment plan optimization system using goCMC. The repair-misrepair-fixation model was implemented to compute the spatial distribution of linear-quadratic model parameters for each spot. A treatment plan optimization module was developed to minimize the difference between the prescribed and actual biological effect. We used a gradient-based algorithm to solve the optimization problem. The system was embedded in the Varian Eclipse treatment planning system under a client-server architecture to achieve a user-friendly planning environment. We tested the system with a 1-dimensional homogeneous water case and 3 3-dimensional patient cases. Our system generated treatment plans with biological spread-out Bragg peaks covering the targeted regions and sparing critical structures. Using 4 NVidia GTX 1080 GPUs, the total computation time, including spot simulation, optimization, and final dose calculation, was 0.6 hour for the prostate case (8282 spots), 0.2 hour for the pancreas case (3795 spots), and 0.3 hour for the brain case (6724 spots). The computation time was dominated by MC spot simulation. We built a biological treatment plan optimization system for IMCT that performs simulations using a fast MC engine, goCMC. To the best of our knowledge, this is the first time that full MC-based IMCT inverse planning has been achieved in a clinically viable time frame. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. ''Spray'' drying unit for spent ion-exchange resins sludges and radioactive concentrates

    International Nuclear Information System (INIS)

    Raibaud, J.

    1985-01-01

    The procedure consisting in drying radwaste either in liquid form or in aqueous suspension is a very attractive solution for volume Reduction. Technicatome presents an experimental spray drying station for 50 kg/hr, using the LEAFLASH process, developed by Rhone Poulenc Recherches. This process, used at full scale in a large number of branches in industry, is applicable to the drying of various materials: bead type ion-echange resins, powered ion exchange resins, centrifuge sludges, filter sludges, evaporator bottoms [fr

  3. Development of biological treatment of high concentration sodium nitrate waste liquid

    International Nuclear Information System (INIS)

    Ogawa, Naoki; Kuroda, Kazuhiko; Shibata, Katsushi; Kawato, Yoshimi; Meguro, Yoshihiro; Takahashi, Kuniaki

    2009-01-01

    An electrolytic reduction, chemical reduction, and biological reduction have been picked up as a method of nitrate liquid waste treatment system exhausted from the reprocessing process. As a result of comparing them, it was shown that the biological treatment was the most excellent method in safety and the economy. (author)

  4. Relationship of Ambient Atmosphere and Biological Aerosol Responses from a Fielded Pyrolysis-Gas Chromatography-Ion Mobility Spectrometry Bioanalytical Detector

    National Research Council Canada - National Science Library

    Snyder, A

    2003-01-01

    .... A pyrolysis-gas chromatography-ion mobility spectrometry stand-alone bioaerosol system was interfaced to an aerosol concentrator to collect ambient background aerosols and produce bioanalytical...

  5. Development of Voltammetric Double-Polymer-Modified Electrodes for Nanomolar Ion Detection for Environmental and Biological Applications

    Science.gov (United States)

    Kim, Yushin

    Qualitative and quantitative electrochemical methods for trace ion analysis of organic and inorganic species with environmental and biological attention have been developed and reported during past decades. The development of fast and accurate electrochemical methods is critical for field applications with various blocking contaminants. Voltammetric method is attractive not only to analyze selective ion species due to its characteristic based on ion lipophilicity, but also to lower the limit of detection by combining with stripping analysis. In my PhD work, I have developed and studied a highly selective and sensitive electrochemical method that can be used to characterize fundamental transport dynamics and to develop electrochemical sensors at liquid/liquid interfaces based on electrochemically-controlled ion transfer and recognition. The understanding of the kinetic and thermodynamic properties of the voltammetric ion transfer through polymer-modified ion-selective electrodes leads to realize the highly selective and sensitive analytical method. The ultrathin polymer membrane is used to maximize a current response by complete exhaustion of preconcentrated ions. Therefore, nanomolar detection is achieved and confirmed by a thermodynamic mechanism that controls the detection limit. It was also demonstrated experimentally and theoretically that more lipophilic ionic species gives a significantly lower detection limit. The voltammetric method was expanded into inexpensive and disposable applications based on pencil lead modified with the thin polymer membrane. In the other hand, micropipet/nanopipet voltammetry as an artificial cell membrane was used to study the interface between two immiscible solutions for environmental and biomedical applications. It is very useful to get quantitative kinetic and thermodynamic information by studying numerical simulations of ion transfer and diffusion. Molecular recognition and transport of heparin and low

  6. Biological effects of environmentally relevant concentrations of the pharmaceutical Triclosan in the marine mussel Perna perna (Linnaeus, 1758)

    Energy Technology Data Exchange (ETDEWEB)

    Sanzi Cortez, Fernando, E-mail: lecotox@unisanta.br [Instituto de Pesquisas Energeticas e Nucleares IPEN-CNEN/SP, 05508-000 Sao Paulo, SP (Brazil); Laboratorio de Ecotoxicologia, Universidade Santa Cecilia, 11045-907 Santos, SP (Brazil); Dias Seabra Pereira, Camilo [Laboratorio de Ecotoxicologia, Universidade Santa Cecilia, 11045-907 Santos, SP (Brazil); Instituto do Mar, Universidade Federal de Sao Paulo, 11030-400 Santos, SP (Brazil); Ramos Santos, Aldo Ramos [Laboratorio de Ecotoxicologia, Universidade Santa Cecilia, 11045-907 Santos, SP (Brazil); Cesar, Augusto; Choueri, Rodrigo Brasil [Laboratorio de Ecotoxicologia, Universidade Santa Cecilia, 11045-907 Santos, SP (Brazil); Instituto do Mar, Universidade Federal de Sao Paulo, 11030-400 Santos, SP (Brazil); Martini, Gisela de Assis [Laboratorio de Ecotoxicologia, Universidade Santa Cecilia, 11045-907 Santos, SP (Brazil); Bohrer-Morel, Maria Beatriz [Instituto de Pesquisas Energeticas e Nucleares IPEN-CNEN/SP, 05508-000 Sao Paulo, SP (Brazil)

    2012-09-15

    Triclosan (5-Chloro-2-(2,4-dichlorophenoxy) phenol) is an antibacterial compound widely employed in pharmaceuticals and personal care products. Although this emerging compound has been detected in aquatic environments, scarce information is found on the effects of Triclosan to marine organisms. The aim of this study was to evaluate the toxicity of a concentration range of Triclosan through fertilization assay (reproductive success), embryo-larval development assay (early life stage) and physiological stress (Neutral Red Retention Time assay - NRRT) (adult stage) in the marine sentinel organism Perna perna. The mean inhibition concentrations for fertilization (IC{sub 50} = 0.490 mg L{sup -1}) and embryo-larval development (IC{sub 50} = 0.135 mg L{sup -1}) tests were above environmental relevant concentrations (ng L{sup -1}) given by previous studies. Differently, significant reduction on NRRT results was found at 12 ng L{sup -1}, demonstrating the current risk of the continuous introduction of Triclosan into aquatic environments, and the need of ecotoxicological studies oriented by the mechanism of action of the compound. - Highlights: Black-Right-Pointing-Pointer Triclosan causes biological adverse effects at environmental relevant concentrations. Black-Right-Pointing-Pointer Mechanisms of action oriented assays were more sensitive to detect biological damages. Black-Right-Pointing-Pointer Currently there is environmental risks concerned Triclosan in aquatic ecosystems. - Triclosan causes biological adverse effects at environmentally relevant concentrations.

  7. Biological effects of environmentally relevant concentrations of the pharmaceutical Triclosan in the marine mussel Perna perna (Linnaeus, 1758)

    International Nuclear Information System (INIS)

    Sanzi Cortez, Fernando; Dias Seabra Pereira, Camilo; Ramos Santos, Aldo Ramos; Cesar, Augusto; Choueri, Rodrigo Brasil; Martini, Gisela de Assis; Bohrer-Morel, Maria Beatriz

    2012-01-01

    Triclosan (5-Chloro-2-(2,4-dichlorophenoxy) phenol) is an antibacterial compound widely employed in pharmaceuticals and personal care products. Although this emerging compound has been detected in aquatic environments, scarce information is found on the effects of Triclosan to marine organisms. The aim of this study was to evaluate the toxicity of a concentration range of Triclosan through fertilization assay (reproductive success), embryo-larval development assay (early life stage) and physiological stress (Neutral Red Retention Time assay - NRRT) (adult stage) in the marine sentinel organism Perna perna. The mean inhibition concentrations for fertilization (IC 50 = 0.490 mg L −1 ) and embryo-larval development (IC 50 = 0.135 mg L −1 ) tests were above environmental relevant concentrations (ng L −1 ) given by previous studies. Differently, significant reduction on NRRT results was found at 12 ng L −1 , demonstrating the current risk of the continuous introduction of Triclosan into aquatic environments, and the need of ecotoxicological studies oriented by the mechanism of action of the compound. - Highlights: ► Triclosan causes biological adverse effects at environmental relevant concentrations. ► Mechanisms of action oriented assays were more sensitive to detect biological damages. ► Currently there is environmental risks concerned Triclosan in aquatic ecosystems. - Triclosan causes biological adverse effects at environmentally relevant concentrations.

  8. Simulation of a relativistic heavy ions beam transport in the matter: contribution of the fragmentation process and biological implications

    International Nuclear Information System (INIS)

    Ibnouzahir, M.

    1995-03-01

    The study of relativistic heavy ion collisions permit an approach of the properties of dense and not hadronic matter, and an analysis of the reaction mechanisms. Such studies are also interesting on the biological point of view, since there exist now well defined projects concerning the radiotherapy with high LET particles as neutrons, protons, heavy ions. It is thus necessary to have a good understanding of the processes which occur in the propagation of a relativistic heavy ion beam (E≥ 100 A.MeV) in matter. We have elaborated a three dimensional transport code, using a Monte Carlo method, in order to describe the propagation of Ne and Ar ions in water. Violent nuclear collisions giving fragmentation process have been taken into account by use of the FREESCO program. We have tested the validity of our transport model and we show an important change of the energy deposition at the vicinity of the Bragg peak; such a distortion, due mainly to fragmentation reactions, is of a great interest for biological applications. (author)

  9. The effect of cation source and dietary cation-anion difference on rumen ion concentrations in lactating dairy cows.

    Science.gov (United States)

    Catterton, T L; Erdman, R A

    2016-08-01

    Many studies have focused on the influence of dietary cation-anion difference (DCAD) on animal performance but few have examined the effect of DCAD on the rumen ionic environment. The objective of this study was to examine the effects of DCAD, cation source (Na vs. K), and anion source (Cl vs. bicarbonate or carbonate) on rumen environment and fermentation. The study used 5 rumen-fistulated dairy cows and 5 dietary treatments that were applied using a 5×5 Latin square design with 2-wk experimental periods. Treatments consisted of (1) the basal total mixed ration (TMR); (2) the basal TMR plus 340mEq/kg of Na (dry matter basis) using NaCl; (3) the basal TMR plus 340mEq/kg of K using KCl; (4) the basal TMR plus 340mEq/kg of Na using NaHCO3; and (5) the basal TMR plus 340mEq/kg of K using K2CO3. On the last day of each experimental period, rumen samples were collected and pooled from 5 different locations at 0, 1.5, 3, 4.5, 6, 9, and 12h postfeeding for measurement of rumen pH and concentrations of strong ions and volatile fatty acids (VFA). Dietary supplementation of individual strong ions increased the corresponding rumen ion concentration. Rumen Na was decreased by 24mEq/L when K was substituted for Na in the diet, but added dietary Na had no effect on rumen K. Rumen Cl was increased by 10mEq/L in diets supplemented with Cl. Cation source had no effect on rumen pH or total VFA concentration. Increased DCAD increased rumen pH by 0.10 pH units and increased rumen acetate by 4mEq/L but did not increase total VFA. This study demonstrated that rumen ion concentrations can be manipulated by dietary ion concentrations. If production and feed efficiency responses to DCAD and ionophores in the diet are affected by rumen Na and K concentrations, then manipulating dietary Na and K could be used either to enhance or diminish those responses. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. The relationship between sucrose hydrolysis, sorbitol formation and mineral ion concentration during bioethanol formation using Zymomonas mobilis 2716

    Energy Technology Data Exchange (ETDEWEB)

    Doelle, M.B.; Doelle, H.W. (Queensland Univ., St. Lucia (Australia). Dept. of Microbiology); Greenfield, P.F. (Queensland Univ., St. Lucia (Australia). Dept. of Chemical Engineering)

    1990-11-01

    Investigations into the relationship between sucrose hydrolysis, sorbitol formation and mineral ion concentration during bioethanol formation by Zymomonas mobilis 2716 revealed two distinct phenomena responsible for carbon flow diversion, a 'sucrose effect' and a 'salt effect'. Neither of the two phenomena affects sucrose hydrolysis, but they divert carbon flow of the fructose monomer leading to its own accumulation, sorbitol or oligosaccharide formation. Sucrose concentrations in excess of 15% (w/v) led to sorbitol formation, the level of which may exceed 2% (w/v) depending upon glucose accumulation during sucrose hydrolysis. Increasing mineral ion concentrations led initially to carbon losses and finally to fructose accumulation instead of sorbitol formation. This carbon loss can be corrected by the addition of invertase, which in turn leads to an increase in sorbitol, fructose and ethanol. Potassium and chloride are the dominant ions responsible for suppression of sorbitol formation and fructose uptake, encouraging oligosaccharide formation. These fructooligosaccharides must be of a type which can be converted to fructose, sorbitol and ethanol through the action of invertase. The requirement of invertase addition to prevent fructooligosaccharide formation is indirect evidence that Z. mobilis 2716 does not produce invertase. (orig.).

  11. Effect of the minority concentration on ion cyclotron resonance heating in presence of the ITER-like wall in JET

    Energy Technology Data Exchange (ETDEWEB)

    Van Eester, D.; Lerche, E.; Crombé, K.; Jachmich, S. [LPP-ERM/KMS, Association Euratom-Belgian State, TEC Partner, Brussels (Belgium); Jacquet, P.; Graham, M.; Kiptily, V.; Matthews, G.; Mayoral, M.-L.; Mc Cormick, K.; Monakhov, I.; Noble, C.; Rimini, F.; Solano, E. R. [Euratom-CCFE Fusion Association, Culham Science Centre (United Kingdom); Bobkov, V.; Maggi, C.; Neu, R.; Pütterich, T. [MPI für Plasmaphysik Euratom Assoziation, Garching (Germany); Czarnecka, A. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Coenen, J. W. [IEK-4, EURATOM-FZJ, TEC Partner, Jülich (Germany); and others

    2014-02-12

    The most recent JET campaign has focused on characterizing operation with the 'ITER-like' wall. One of the questions that needed to be answered is whether the auxiliary heating methods do not lead to unacceptably high levels of impurity influx, preventing fusion-relevant operation. In view of its high single pass absorption, hydrogen minority fundamental cyclotron heating in a deuterium plasma was chosen as the reference wave heating scheme in the ion cyclotron domain of frequencies. The present paper discusses the plasma behavior as a function of the minority concentration X[H] in L-mode with up to 4MW of RF power. It was found that the tungsten concentration decreases by a factor of 4 when the minority concentration is increased from X[H] ≈ 5% to X[H] % 20% and that it remains at a similar level when X[H] is further increased to 30%; a monotonic decrease in Beryllium emission is simultaneously observed. The radiated power drops by a factor of 2 and reaches a minimum at X[H] ≈ 20%. It is discussed that poor single pass absorption at too high minority concentrations ultimately tailors the avoidance of the RF induced impurity influx. The edge density being different for different minority concentrations, it is argued that the impact ICRH has on the fate of heavy ions is not only a result of core (wave and transport) physics but also of edge dynamics and fueling.

  12. Depth concentrations of deuterium ions implanted into some pure metals and alloys

    International Nuclear Information System (INIS)

    Didyk, A.Yu.; Wisniewski, R.; Kitowski, K.; Wilczynska, T.; Hofman, A.; Kulikauskas, V.; Shiryaev, A.A.; Zubavichyus, Ya.V.

    2011-01-01

    Pure metals (Cu, Ti, Zr, V, Pd) and diluted Pd alloys (Pd-Ag, Pd-Pt, Pd-Ru, Pd-Rh) were implanted by 25-keV deuterium ions at fluences in the range (1.2-2.3) x 10 22 D + /m 2 . The post-treatment depth distributions of deuterium ions were measured 10 days and three months after the implantation by using Elastic Recoil Detection Analysis (ERDA) and Rutherford Backscattering (RBS). Comparison of the obtained results allowed us to make conclusions about relative stability of deuterium and hydrogen gases in pure metals and diluted Pd alloys. Very high diffusion rates of implanted deuterium ions from V and Pd pure metals and Pd alloys were observed. Small-angle X-ray scattering revealed formation of nanosized defects in implanted corundum and titanium

  13. Rapid MCNP simulation of DNA double strand break (DSB) relative biological effectiveness (RBE) for photons, neutrons, and light ions.

    Science.gov (United States)

    Stewart, Robert D; Streitmatter, Seth W; Argento, David C; Kirkby, Charles; Goorley, John T; Moffitt, Greg; Jevremovic, Tatjana; Sandison, George A

    2015-11-07

    To account for particle interactions in the extracellular (physical) environment, information from the cell-level Monte Carlo damage simulation (MCDS) for DNA double strand break (DSB) induction has been integrated into the general purpose Monte Carlo N-particle (MCNP) radiation transport code system. The effort to integrate these models is motivated by the need for a computationally efficient model to accurately predict particle relative biological effectiveness (RBE) in cell cultures and in vivo. To illustrate the approach and highlight the impact of the larger scale physical environment (e.g. establishing charged particle equilibrium), we examined the RBE for DSB induction (RBEDSB) of x-rays, (137)Cs γ-rays, neutrons and light ions relative to γ-rays from (60)Co in monolayer cell cultures at various depths in water. Under normoxic conditions, we found that (137)Cs γ-rays are about 1.7% more effective at creating DSB than γ-rays from (60)Co (RBEDSB  =  1.017) whereas 60-250 kV x-rays are 1.1 to 1.25 times more efficient at creating DSB than (60)Co. Under anoxic conditions, kV x-rays may have an RBEDSB up to 1.51 times as large as (60)Co γ-rays. Fission neutrons passing through monolayer cell cultures have an RBEDSB that ranges from 2.6 to 3.0 in normoxic cells, but may be as large as 9.93 for anoxic cells. For proton pencil beams, Monte Carlo simulations suggest an RBEDSB of about 1.2 at the tip of the Bragg peak and up to 1.6 a few mm beyond the Bragg peak. Bragg peak RBEDSB increases with decreasing oxygen concentration, which may create opportunities to apply proton dose painting to help address tumor hypoxia. Modeling of the particle RBE for DSB induction across multiple physical and biological scales has the potential to aid in the interpretation of laboratory experiments and provide useful information to advance the safety and effectiveness of hadron therapy in the treatment of cancer.

  14. Concentrations and biological availability of 238U and 230Th in the environs of a uranium milling operation

    International Nuclear Information System (INIS)

    Ibrahim, S.; Flot, S.; Whicker, F.W.

    1982-01-01

    This paper reports on a study whose objectives were to determine 238 U and 230 Th concentrations in soil and native plants from various sites around a conventional acid leach uranium milling operation in the Western US, and to estimate plant/soil concentration factors. Soil and vegetation samples were collected from exposed, weathered tailings; near the edge of a tailings pond; from a reclamation area; and at several native range background (control) locations. The results indicate that mean plant/soil concentration factors varied significantly among sites and between radionuclides, but no significant differences between plant groups were found. Concentration factors for 230 Th were greater than for 238 U for plants growing at the edge of the tailings pond. It is speculated that the lower concentration factors for uranium relative to thorium at this site may be due to the proportion of their contents in soil that is biologically available for plant uptake

  15. Demonstration on endurance of ion exchange membrane immersed in high-concentration tritiated water under the Broader Approach Activities

    Energy Technology Data Exchange (ETDEWEB)

    Iwai, Yasunori, E-mail: iwai.yasunori@jaea.go.jp; Sato, Katsumi; Kawamura, Yoshinori; Yamanishi, Toshihiko

    2013-10-15

    Highlights: • Endurance of Nafion ion exchange membrane immersed in 1.38 × 10{sup 12} Bq/kg of highly concentrated tritiated water was demonstrated. • Degradation of Nafion backbone structure by tritium beta was similar to that by gamma rays and electron beams at an equivalent dose. • Degradation directly by radiation was dominant at room temperature compared with that by reactions with radicals produced from water radiolysis. -- Abstract: The Nafion{sup ®} ion exchange membrane is a key material for electrolysis cells of the water detritiation system. Endurance of Nafion ion exchange membrane immersed in 1.38 × 10{sup 12} Bq/kg of highly concentrated tritiated water has been demonstrated at room temperature for up to 2 years under the Broader Approach Activities. The curves of percent elongation at break vs. dose and tensile strength vs. dose for the Nafion membranes immersed in tritiated water were well consistent with those for Nafion membranes irradiated to an equivalent dose with gamma rays and electron beams. This shows that the degradation of Nafion backbone structure by tritium beta is similar to that by gamma rays and electron beams. The results of ferric Fenton test indicated that the degradation directly by radiation was dominant at room temperature compared with that by reactions with radicals produced from water radiolysis. The curve of ion exchange capacity vs. dose for the Nafion membranes immersed in tritiated water was also well consistent with that for Nafion membranes irradiated to an equivalent dose with gamma rays and electron beams. These results showed irradiation tests with gamma rays and electron beams were alternative for predicting degradation of ion exchange membrane by tritium beta.

  16. Speciation of Am(III)/Eu(III) sorbed on γ-alumina. Effect of metal ion concentration

    International Nuclear Information System (INIS)

    Kumar, S.; Tomar, B.S.; Godbole, S.V.

    2013-01-01

    The present paper describes the speciation of Am(III)/Eu(III) sorbed on γ-alumina, and its evolution with changing metal ion concentration, studied using batch sorption experiment, time resolved fluorescence spectroscopy (TRFS), extended X-ray absorption fine structure (EXAFS) and surface Complexation modeling (SCM). Though numerous studies exist in the literature on the speciation of trivalent actinides and lanthanides on alumina surface, the mechanism of sorption at high metal ion concentrations is not yet fully understood. Batch sorption experiments of Am(III) on γ-alumina under varying condition of pH (3-10), ionic strength (0.005-0.1 M NaClO 4 ) and metal ion concentration (10 -7 -10 -4 M) were performed. Higher metal ion concentration was achieved by the addition of Eu(III) considering it as an analogue of Am(III). Time resolved fluorescence spectroscopy (TRFS) study of Eu(III) sorbed on γ-alumina at the metal ion concentration of 5.0 x 10 -5 M was carried out over pH 4 to 7. TRFS showed the presence of two surface species, with distinctly different fluorescence decay life times. The shorter lifetime value and its changing pattern with pH indicate the surface species corresponding to this component to be monodentate species > AlOAm 2+ and its hydrolyzed forms. The sorbed Eu 3+ species corresponding to the longer lifetime value has 2-3 water molecules in its first coordination sphere and is multidentate in its binding on alumina surface. Extended X-ray absorption fine structure (EXAFS) measurement of Eu:γ-Al 2 O 3 sorption systems at pH 6.18 and 7.15 corroborate the existence of two surface complexes. Further it suggests the edge sharing bidentate binding of Eu on AlO 6 octahedra as the co-ordination mode of the higher lifetime component. Surface Complexation Modeling (SCM) of Am(III)/Eu(III) sorption onto γ-alumina at pH ≤7 has been carried out using these two surface species. 2-pK surface complexation modeling coupled with constant capacitance model

  17. Ion association in concentrated NaCl brines from ambient to supercritical conditions: results from classical molecular dynamics simulations

    Directory of Open Access Journals (Sweden)

    Collings Matthew D

    2002-11-01

    Full Text Available Highly concentrated NaCl brines are important geothermal fluids; chloride complexation of metals in such brines increases the solubility of minerals and plays a fundamental role in the genesis of hydrothermal ore deposits. There is experimental evidence that the molecular nature of the NaCl–water system changes over the pressure–temperature range of the Earth's crust. A transition of concentrated NaCl–H2O brines to a "hydrous molten salt" at high P and T has been argued to stabilize an aqueous fluid phase in the deep crust. In this work, we have done molecular dynamic simulations using classical potentials to determine the nature of concentrated (0.5–16 m NaCl–water mixtures under ambient (25°C, 1 bar, hydrothermal (325°C, 1 kbar and deep crustal (625°C, 15 kbar conditions. We used the well-established SPCE model for water together with the Smith and Dang Lennard-Jones potentials for the ions (J. Chem. Phys., 1994, 100, 3757. With increasing temperature at 1 kbar, the dielectric constant of water decreases to give extensive ion-association and the formation of polyatomic (NanClmn-m clusters in addition to simple NaCl ion pairs. Large polyatomic (NanClmn-m clusters resemble what would be expected in a hydrous NaCl melt in which water and NaCl were completely miscible. Although ion association decreases with pressure, temperatures of 625°C are not enough to overcome pressures of 15 kbar; consequently, there is still enhanced Na–Cl association in brines under deep crustal conditions.

  18. Concentration levels of rare-earth elements and thorium on plants from the Morro de Ferro environment as an indicator for the biological availability of transuranium elements

    International Nuclear Information System (INIS)

    Miekeley, N.; Casartelli, E.A.; Dotto, R.M.

    1994-01-01

    Plants and soils from a natural thorium and rare-earth element occurrence (Morro do Ferro, Brazil) were analyzed by alpha spectrometry (Th) and ICP-AES (REE), after pre-concentration of the elements by solvent extraction, co-precipitation and ion exchange procedures. Leaching experiments with humic acid solutions and different soils were performed to estimate the fraction of elements biologically available. High concentrations of the light rare-earth elements (LREE) and of Th, reaching some hundreds of μg/g-ash, were measured in plant leaves from the areas of the highest concentration of these elements in soil and in near-surface waters. Chondrite normalized REE plots of plant leaves and corresponding soils are very similar, suggesting that there is no significant fractionation between the REE during uptake from the soil solution and incorporation into the leaves. However, Ce-depletion was observed for some plant species, increasing for Solanum ciliatum in the sequence: leaves -3 to 10 -2 . Leaching experiments confirmed the importance of humic acid complexation for the bio-uptake of Th and REE and further showed that only a very small fraction of these elements in soil is leachable. The implications of these results on the calculated CR's will be discussed. (author) 26 refs.; 5 figs.; 5 tabs

  19. Electrochemical behavior and biological response of Mesenchymal Stem Cells on cp-Ti after N-ions implantation

    Energy Technology Data Exchange (ETDEWEB)

    Rizwan, M.; Ahmad, A. [Department of Metallurgical and Materials Engineering, University of Engineering and Technology, 54890 Lahore (Pakistan); Deen, K.M. [Corrosion Control Research Cell, Department of Metallurgy and Materials Engineering, CEET, University of the Punjab, 54590 Lahore (Pakistan); Haider, W., E-mail: haiderw@utpa.edu [Mechanical Engineering Department, University of Texas Pan American, Edinburg, TX 78539 (United States)

    2014-11-30

    Highlights: • Nitrogen ions of known dosage were implanted on cp-Ti. • Increase in surface roughness with increase in ions dose was confirmed by AFM. • TiN{sub 0.3} and Ti{sub 3}N{sub 2−x} nitride phases were formed and validated by XRD. • The ions implantation reduced the corrosion rate and stabilized the passive film. • Surface roughness greatly affected the morphology and growth of Mesenchymal Stem Cells. - Abstract: Titanium and its alloys are most widely used as implant materials due to their excellent biocompatibility, mechanical properties and chemical stability. In this study Nitrogen ions of known dosage were implanted over cp-Ti by Pelletron accelerator with beam energy of 0.25 MeV.The atomic force microscopy of bare and nitrogen implanted specimens confirmed increase in surface roughness with increase in nitrogen ions concentration. X-ray diffraction patterns of ions implanted surfaces validated the formation of TiN{sub 0.3} and Ti{sub 3}N{sub 2-x}nitride phases. The tendency to form passive film and electrochemical behavior of these surfaces in ringer lactate (RL) solution was evaluated by Potentiodynamic polarization and electrochemical impedance spectroscopy respectively. It is proved that nitrogen ions implantation was beneficial to reduce corrosion rate and stabilizing passive film by increasing charge transfer resistance in RL. It was concluded that morphology and proliferation of Mesenchymal Stem Cells on nitrogen ions implanted surfaces strongly depends on surface roughness and nitride phases.

  20. A nonlocal species concentration theory for diffusion and phase changes in electrode particles of lithium ion batteries

    Science.gov (United States)

    Zhang, Tao; Kamlah, Marc

    2018-01-01

    A nonlocal species concentration theory for diffusion and phase changes is introduced from a nonlocal free energy density. It can be applied, say, to electrode materials of lithium ion batteries. This theory incorporates two second-order partial differential equations involving second-order spatial derivatives of species concentration and an additional variable called nonlocal species concentration. Nonlocal species concentration theory can be interpreted as an extension of the Cahn-Hilliard theory. In principle, nonlocal effects beyond an infinitesimal neighborhood are taken into account. In this theory, the nonlocal free energy density is split into the penalty energy density and the variance energy density. The thickness of the interface between two phases in phase segregated states of a material is controlled by a normalized penalty energy coefficient and a characteristic interface length scale. We implemented the theory in COMSOL Multiphysics^{circledR } for a spherically symmetric boundary value problem of lithium insertion into a Li_xMn_2O_4 cathode material particle of a lithium ion battery. The two above-mentioned material parameters controlling the interface are determined for Li_xMn_2O_4 , and the interface evolution is studied. Comparison to the Cahn-Hilliard theory shows that nonlocal species concentration theory is superior when simulating problems where the dimensions of the microstructure such as phase boundaries are of the same order of magnitude as the problem size. This is typically the case in nanosized particles of phase-separating electrode materials. For example, the nonlocality of nonlocal species concentration theory turns out to make the interface of the local concentration field thinner than in Cahn-Hilliard theory.

  1. Comparative Salt Stress Study on Intracellular Ion Concentration in Marine and Salt-adapted Freshwater Strains of Microalgae

    Directory of Open Access Journals (Sweden)

    Ahmad Farhad TALEBI

    2013-08-01

    Full Text Available Salinity imposes significant stresses in various living organisms including microalgae. High extracellular concentration of Na+ directly influences ionic balance inside the cell and subsequently the cellular activities. In the present study, the effect of such stress on growth and intracellular ions concentration (IIC of Dunaliella salina and Chlorella Spp. was investigated. IIC was analyzed using Ion chromatography technique. D. salina showed the highest degree of resistance to increase in salinity as little changes occurred both in IIC and in growth parameters. D. salina could maintain the balance of K+ inside the cell and eject the excess Na+ even at NaCl concentrations above 1M. Moreover, D. salina accumulated β-carotene in order to protect its photosynthetic apparatus. Among Chlorella species, C. vulgaris showed signs of adaptation to high content of salinity, though it is a fresh water species by nature. Moreover, the response shown by C. vulgaris to rise in salinity was even stronger than that of C. salina, which is presumably a salt-water resistant species. In fact, C. vulgaris could maintain intracellular K+ better than C. salina in response to increasing salinity, and as a result, it could survive at NaCl concentrations as high as 0.75 M. Marine strains such as D. salina well cope with the fluctuations in salinity through the existing adaptation mechanisms i.e. maintaining the K+/N+ balance inside the cell, K+ accumulation and Na+ ejection, accumulation of photosynthetic pigments like β-carotene.

  2. [Ion channels that are sensitive to the extracellular concentration of protons: their structure, function, pharmacology and pathophysiology].

    Science.gov (United States)

    Mercado, F; Vega, R; Soto, E

    Acid sensing ion channels (ASIC) members of the ENaC degenerine channel family, have been shown to participate in various sensorial pathways including nociception, also they have been shown to participate in synaptic transmission, learning and memory processes and in the physiopathology of the ischemic stroke. The proton concentration in the organism is strictly regulated by distinct buffer systems. Drastic changes of pH are generated only by pathological conditions as is the ischemia; however, some physiological processes may produce local changes in the extracellular pH. Recently, a new family of proton receptors known as ASIC has been cloned. These are ionic channels inactivated at physiological pH (7.4) and activated with a pH fall (increase in H+ concentration). ASICs are permeable to sodium ions and in a lesser degree to calcium ions, activation of these channels leads to an increase in cell excitability. The ASICs are distributed widely in the central and peripheral nervous system, and in specialized epithelia. In the past few years they have become a focus of interest due to its role in nociception, taste perception, long term potentation and the physiopathology of ischemic stroke. In this review we address the most relevant molecular, physiological and pharmacological aspects of the ASICs, its participation in some pathological process, and the perspectives of basic and clinic investigation in this arising research field.

  3. Biological dosimetry of heavy ion induced chromosome lesions in human peripheral blood lymphocytes of different healthy donors

    International Nuclear Information System (INIS)

    Groesser, T.; Rydberg, B.; Ritter, S.; Hessel, P.; Kraft, G.

    2003-01-01

    Full text: In the presented work the effect of sparsely ionizing X-rays or densely ionizing carbon ions on human peripheral blood lymphocytes (PBL) from healthy donors regarding the fluctuations in radiosensitivity within the same donor and between different donors was examined. This is not only of special interest for physicians and radiation biologists but also plays an important role in space flights because such fluctuations in the radiation response would reduce the accuracy of the biological dosimetry. In this context, biological changes in the aberration rate of metaphase cells as well as in cell proliferation and the mitotic index were measured. Since chromosome analyses are presently the most powerful biological method to quantify radiation exposure, the study focused on the measurements of chromosome aberrations in first-metaphase cells. The investigations showed that the aberration yield after 400 MeV/u carbon ion exposure (LET = 11 keV/micrometer) was higher than after X-irradiation. The aberration yield in first mitotic cells as well as the proportion of damaged cells was stable over the examined period up to 72h after exposure to X-rays or carbon ions. Furthermore, the results of the presented work revealed pronounced fluctuations in the measured parameters in the same donor as well as between different donors. If the dose effect curves of such parameters were used as calibration curves for radiation dose assessment these fluctuations will decrease their potential of use for dose estimation. This demonstrates that a general calibration curve for dose assessment might not be sufficiently precise and individual calibration curves might improve the accuracy of the biological dosimetry

  4. Concentration of Co2+, Fe3+ and Zn2+ ions with microbiological collectors

    International Nuclear Information System (INIS)

    Fisel, S.; Dulman, V.; Cecal, A.

    1975-01-01

    By means of the Spicaria Biolacea Abbott fungus a satisfactory microbiological concentration of 60 Co 2+ , sup(55+59)Fe 3+ and 65 Zn 2+ can be obtained under optimum experimental conditions. By repeating the cultures on the media obtained after filtration, multistage processes, and by adding the necessary nutritive substances, practically quantitative concentration of these three elements can be produced. The experimental results plead in favour of a concentration mechanism of the isotopes inside the cell with no surface adsorption. The influence of the experimental conditions i.e. pH, time and concentration have been investigated. (T.G.)

  5. Concentration dependent spectroscopic properties of Dy3+ ions doped boro-phosphate glasses

    Science.gov (United States)

    Mariyappan, M.; Marimuthu, K.

    2016-05-01

    Dy3+ ions doped boro-phosphate glasses have been synthesized by melt quenching method and characterized through FTIR, absorption and luminescence spectral measurements. The presence of various stretching and bending vibrations of different borate and phosphate groups were identified from the FTIR spectra. In order to examine the electronic band structure of the studied glasses, Optical energy gap (Eopt) and Urbach energy (ΔE) values were estimated from the absorption spectra. The Judd-Ofelt (JO) intensity parameters were calculated to examine the symmetry of the ligand environment around the Dy3+ ions site. The emission spectra exhibit two intense emission bands at around 482 nm (blue) and 574 nm (yellow) corresponding to the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions respectively. The emission spectra were characterized through Commission International d'Eclairage (CIE) 1931 chromaticity diagram to explore its suitability for WLED applications.

  6. Removal method of fluorescent dyes as pretreatment for measurement of major ion concentrations and hydrogen and oxygen isotopic ratios

    International Nuclear Information System (INIS)

    Nakata, Kotaro; Hasegawa, Takuma; Kashiwaya, Koki; Kodama, Hiroki; Miyajima, Tohru

    2011-01-01

    The major ion concentration and isotope ratio of hydrogen and oxygen can provide important information for migration of groundwater. Sometimes, quantitative estimation of these chemical and isotopic characteristics of solution is necessary for groundwater containing fluorescent dyes, which are used in drilling borehole and tracer experiments. However, sometimes correct estimation is disturbed by dyes and they become a cause of troubles for measurement equipments. Thus development of method to remove dyes is required so that the characteristics of groundwater can be estimated without the negative effect of dyes on measurement or equipments. In this study, removal of four representative dyes (Uranin, Eosin, Naphthalenesulfonic acid sodium(NAP) and Amino G acid potassium salt (AG)) was investigated. Uranin and Eosin were found to be removed by non-ionic synthetic resin: HP2MG. 99.99% of the dyes were removed from initial solutions containing dyes with 10 mg/L after contact with resin, while the contact had little effect on ion concentrations and oxygen and hydrogen isotope ratios. Thus the chemical and isotopic characteristics of groundwater samples containing Uranin and Eosin can be obtained by using the HP2MG resin. On the other hand, the NAP and AG were found to be difficult to remove by the HP2MG resin but they were able to be removed by anion exchange resin (Dowex 1x8). Though contact of solution with Dowex 1x8 did not affect cation concentrations and hydrogen and oxygen isotope ratios, anion concentrations were changed by the contact. Therefore the Dowex 1x8 is only applicable to estimation of the cation concentrations and isotope ratio of hydrogen and oxygen. When both anion and cation concentrations from the samples were necessary, Uranin or Eosin were recommended as a tracer in drilling or tracer experiments. (author)

  7. Translocation of metal ions from soil to tobacco roots and their concentration in the plant parts.

    Science.gov (United States)

    da Silva, Cleber Pinto; de Almeida, Thiago E; Zittel, Rosimara; de Oliveira Stremel, Tatiana R; Domingues, Cinthia E; Kordiak, Januário; de Campos, Sandro Xavier

    2016-12-01

    This paper presents a study on the translocation factors (TFs) and bioconcentration factors (BCFs) of copper (Cu), manganese (Mn), zinc (Zn), cobalt (Co), chromium (Cr), cadmium (Cd), lead (Pb), iron (Fe), nickel (Ni), and arsenic (As) ions in roots, stems, and leaves of tobacco. The results revealed that during the tobacco growth, the roots are able to increase the sensitiveness of the physiological control, reducing the translocation of the metals Ni (0.38) and Pb (0.48) to the leaves. Cd and Zn presented factors TF and BCF >1 in the three tissues under analysis, which indicates the high potential for transportation and accumulation of these metals in all plant tissues. The TF values for Cr (0.65) and As (0.63) revealed low translocation of these ions to the aerial parts, indicating low mobility of ions from the roots. Therefore, tobacco can be considered an efficient accumulator of Ni, Cr, As and Pb in roots and Cd and Zn in all plant parts.

  8. Effect of Fe ion concentration on corrosion of carbon steel in CO2 environment

    DEFF Research Database (Denmark)

    Rogowska, Magdalena; Gudme, J.; Rubin, A.

    2016-01-01

    In this work, the corrosion behaviour of steel wires in solutions containing different concentrations of Fe2+ was investigated by the linear polarisation resistance method, while the evolution of pH was monitored in situ and changes of the Fe2+ concentration were monitored ex situ. Characterisation...

  9. Zinc, copper and lead contents of wines. Comparison between the total concentrations by atomic absorption spectrometry and the concentrations of the free ions by polarography

    Directory of Open Access Journals (Sweden)

    J.-B. Fournier

    1998-03-01

    Full Text Available In the introduction of this article, some examples of the use of trace element data in the characterisation of viticultural produce are reminded. This paper described the determination of zinc, copper and lead by two techniques based on radically different principles. The atomic absorption spectrometry, applied after the mineralisation of the samples by wet process, allows the determination of the total element contents in wine. The polarography allows the analysis of the concentrations of these elements that are under labile chemical forms, and which are dissolved under the ionic forms Zn++, Cu++ and Pb++. The wines analysed in this study were produced from three different parcels chosen in relation to their geological qualities. The vines implanted on these parcels are strictly identical, and three fermentation techniques were applied to each lots of grapes. The results obtained shows that the copper is only under ionic form and that the temperature of the fermentation influences the total copper level in the final wine. At the opposite, there is no ion Pb++ in the samples, but a long duration of maceration increases the lead content. Concerning zinc, only the ions Zn++ are present in the wine in case of a short duration of the maceration. When this duration increases, some other chemical forms of zinc are dissolved in addition to the ions Zn++ which are instantaneously dissociated in aqueous solutions. The problem of the contamination of grapes by the materials used, the phytosanitary treatments and the atmospheric pollution is discussed. The knowledge of the proportion of a trace element that is under ionic forms is indispensable to evaluate the bio-availability of the considered element and the toxicologic risks. The advent and the expansion of the electrochemical methods is expected as an important advance in this field of research.

  10. Impact of incoherent pumping field and Er3+ ion concentration on group velocity and index of refraction in an Er3+-doped YAG crystal

    International Nuclear Information System (INIS)

    Jafarzadeh, Hossein; Asadpour, Seyyed Hossein; Soleimani, H Rahimpour

    2015-01-01

    The effect of Er 3+ ion concentration and incoherent pumping field on the refractive index and group index in an Er 3+ : YAG crystal is investigated. It is shown that under different concentrations of Er 3+ ion in the crystal, the index of refraction and absorption can be changed and a high index of refraction is accompanied by amplification in the medium. Also, it is shown that with the switching from subluminal to superluminal, or vice versa, light propagation can be obtained by different concentrations of Er 3+ ions in the crystal. (paper)

  11. Impact of tissue specific parameters on the predition of the biological effectiveness for treatment planning in ion beam therapy

    International Nuclear Information System (INIS)

    Gruen, Rebecca Antonia

    2014-01-01

    Treatment planning in ion beam therapy requires a reliable estimation of the relative biological effectiveness (RBE) of the irradiated tissue. For the pilot project at GSI Helmholtzzentrum fuer Schwerionenforschung GmbH and at other European ion beam therapy centers RBE prediction is based on a biophysical model, the Local Effect Model (LEM). The model version in use, LEM I, is optimized to give a reliable estimation of RBE in the target volume for carbon ion irradiation. However, systematic deviations are observed for the entrance channel of carbon ions and in general for lighter ions. Thus, the LEM has been continuously developed to improve accuracy. The recent version LEM IV has proven to better describe in-vitro cell experiments. Thus, for the clinical application of LEM IV it is of interest to analyze potential differences compared to LEM I under treatment-like conditions. The systematic analysis presented in this work is aiming at the comparison of RBE-weighted doses resulting from different approaches and model versions for protons and carbon ions. This will facilitate the assessment of consequences for clinical application and the interpretation of clinical results from different institutions. In the course of this thesis it has been shown that the RBE-weighted doses predicted on the basis of LEM IV for typical situations representing chordoma treatments differ on average by less than 10 % to those based on LEM I and thus also allow a consistent interpretation of the clinical results. At Japanese ion beam therapy centers the RBE is estimated using their clinical experience from neutron therapy in combination with in-vitro measurements for carbon ions (HIMAC approach). The methods presented in this work allow direct comparison of the HIMAC approach and the LEM and thus of the clinical results obtained at Japanese and European ion beam therapy centers. Furthermore, the sensitivity of the RBE on the model parameters was evaluated. Among all parameters the

  12. Failla Memorial lecture. The future of heavy-ion science in biology and medicine.

    Science.gov (United States)

    Tobias, C A

    1985-07-01

    Interplanetary space contains fluxes of fast moving atomic nuclei. The distribution of these reflects the atomic composition of the universe, and such particles may pose limitations for space flight and for life in space. Over the past 50 years, since the invention of Ernest Lawrence's cyclotron, advances in accelerator technology have permitted the acceleration of charged nuclei to very high velocities. Currently, beams of any stable isotope species up to uranium are available at kinetic energies of several hundred MeV/nucleon at the Berkeley Bevalac. Recently, new areas of particle physics research relating to the mechanisms of spallation and fission have opened up for investigation, and it is now realistic to search for nuclear super-dense states that might be produced in heavy nuclear collisions. The heavy ions hold interest for a broad spectrum of research because of their effectiveness in producing a series of major lesions in DNA along single particle tracks and because of the Bragg depth ionization properties that allow the precise deposition of highly localized doses deep in the human body. Individual heavy ions can also interrupt the continuity of membraneous regions in cells. Heavy ions, when compared to low-LET radiation, have increased effectiveness for mammalian cell lethality, chromosome mutations, and cell transformation. The molecular mechanisms are not completely understood but appear to involve fragmentation and reintegration of DNA. Cells attempt to repair these lesions, and many of the deleterious effects are due to misrepair or misrejoining of DNA. Heavy ions do not require the presence of oxygen for producing their effects, and hypoxic cells in necrotic regions have nearly the same sensitivity as cells in well-oxygenated tissues. Heavy ions are effective in delaying or blocking the cell division process. Heavy ions are also strong enhancers of viral-induced cell transformation, a process that requires integration of foreign DNA. Some cell

  13. Effect of high calcium concentration influents on enhanced biological phosphorus removal process

    International Nuclear Information System (INIS)

    Montoya Martinez, T.; Aguado Garcia, D.; Ferrer Polo, J.

    2010-01-01

    In this work, the effect of calcium concentration in wastewater on the polyphosphate accumulating organisms (PAO) is investigated as well as its influence in PAO metabolism, specifically in the Y P O4 (ratio between phosphorus release and acetic acid uptake). For this study a sequencing batch reactor (SBR) anaerobic-aerobic was used, in which the PAO enriched biomass was exposed to different calcium concentrations in the influent wastewater. The results indicate that until a given calcium level in the influent wastewater (35 mg Ca/l) the metabolism is not affect, but higher calcium concentrations lead to significant Y P O4 decline. (Author) 18 refs.

  14. Electrochemical behavior and biological response of Mesenchymal Stem Cells on cp-Ti after N-ions implantation

    Science.gov (United States)

    Rizwan, M.; Ahmad, A.; Deen, K. M.; Haider, W.

    2014-11-01

    Titanium and its alloys are most widely used as implant materials due to their excellent biocompatibility, mechanical properties and chemical stability. In this study Nitrogen ions of known dosage were implanted over cp-Ti by Pelletron accelerator with beam energy of 0.25 MeV.The atomic force microscopy of bare and nitrogen implanted specimens confirmed increase in surface roughness with increase in nitrogen ions concentration. X-ray diffraction patterns of ions implanted surfaces validated the formation of TiN0.3 and Ti3N2-xnitride phases. The tendency to form passive film and electrochemical behavior of these surfaces in ringer lactate (RL) solution was evaluated by Potentiodynamic polarization and electrochemical impedance spectroscopy respectively. It is proved that nitrogen ions implantation was beneficial to reduce corrosion rate and stabilizing passive film by increasing charge transfer resistance in RL. It was concluded that morphology and proliferation of Mesenchymal Stem Cells on nitrogen ions implanted surfaces strongly depends on surface roughness and nitride phases.

  15. Lysimeter study with a cambric arenosol exposed to artificial acid rain: I. Concentrations of ions in leachate

    International Nuclear Information System (INIS)

    Sogn, T.A.; Abrahamsen, G.; Stuanes, A.O.

    1993-01-01

    The effects of artificial acid rain on soil leachate composition were studied in a lysimeter experiment. Cambic Arenosol (Typic Udipsamment) in monolith lysimeters was treated for 6 1/2 year with 125 mm yr -1 artificial rain in addition to natural precipitation. Artificial acid rain was produced from groundwater with H 2 SO 4 added. pH levels of 6.1, 4 and 3 were used. Increasing content of H 2 SO 4 in the artificial rain increased the concentration of Ca 2+ and Mg 2+ in the leachate significantly. The pH of the leachate was slightly reduced only by the most acidic treatment (pH 3). The H + retention was not accompanied by a proportionate increase in the Al ion concentration. A slight increase in the Al ion concentration was only observed in the leachate from the pH 3-treated lysimeter. It is concluded that cation exchange and/or weathering were the main buffer mechanisms in the soil. The study supports conclusions from other acidification studies, that acidic precipitation is likely to increase the leaching of Ca 2+ and Mg 2+ from soils. 25 refs., 3 figs., 7 tabs

  16. An introduction to the technique of combined ion mobility spectrometry-mass spectrometry for the analysis of complex biological samples

    International Nuclear Information System (INIS)

    McDowall, Mark A.; Bateman, Robert H.; Bajic, Steve; Giles, Kevin; Langridge, Jim; McKenna, Therese; Pringle, Steven D.; Wildgoose, Jason L.

    2008-01-01

    Full Text: Ultra Performance Liquid Chromatography (UPLC) offers several advantages compared with conventional High Performance Liquid Chromatography (HPLC) as an 'inlet system' for mass spectrometry. UPLC provides improved chromatographic resolution, increased sensitivity and reduced analysis time. This is achieved through the use of sub 2μm particles (stationary phase) combined with high-pressure solvent delivery (up to 15,000 psi). When coupled with orthogonal acceleration time-of-flight (oa-TOF) mass spectrometry (MS), UPLC presents a means to achieve high sample throughput with reduced spectral overlap, increased sensitivity, and exact mass measurement capabilities with high mass spectral resolution (Ca 20,000 FWHM). Dispersive ion mobility spectrometry (IMS) implemented within a traveling-wave ion guide provides an orthogonal separation strategy for ions in the gas phase that can resolve isobaric ions formed by either Electrospray of MALDI ionization typically in Ca 20 mille seconds. All three techniques have the potential to be combined on-line (e.g. UPLC-IMS-MS/MS) in real time to maximize peak capacity and resolving power for the analysis of complex biological mixtures including; intact proteins, modified peptides and endogenous/exogenous metabolites

  17. Biological effects induced by the inner-target reaction of accelerated 7Li+3 ions with wheat embryo

    International Nuclear Information System (INIS)

    Yang Juncheng; Pan Wei; Zheng Qicheng; Liu Luxiang; Wang Jing; Zhao Linshu; Yu Weixiang; Zhao Wenrong; Bai Xixiang

    2004-01-01

    Using the mechanism of the nuclear reaction of accelerated 7 Li +3 ions with the inner target in mutant material i.e 1 H( 7 Li, 7 Be)n, the biological effects were studied. The wheat seeds were irradiated with the doses ranged from 1.416 x 10 10 ions/cm 2 to 1.416 x 10 12 ions/cm 2 . It was found that the cell membrane ruptured, the plasmolysis occurred, the nucleus shape changed. The serious changes of the chloroplast were as follows: the membrane protuberance, the grand disorder, the membrane disappearance, crista of mitochondrion rupture etc. by checking of the sub-microstructure of leaf cell. The single micronucleus and multi-micronucleus were observed at the interphase. The chromosome aberrational cells including chromosome fragment, lagging chromosome, chromosome bridge and circular chromosome were found during the mitosis. RAPD analysis of seedling genomic DNA variation in M 2 generation of three mutants showed their DNA sequences had changed. The result confirmed that the implantation of 7 Li +3 ions could induce genetic mutation in wheat

  18. Set-up and calibration of a method to measure {sup 10}B concentration in biological samples by neutron autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Gadan, M.A. [National Commission for Atomic Energy (CNEA), Buenos Aires (Argentina); Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Bortolussi, S., E-mail: silva.bortolussi@pv.infn.it [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute for Nuclear Physics (INFN), Section of Pavia, Pavia (Italy); Postuma, I. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Ballarini, F. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute for Nuclear Physics (INFN), Section of Pavia, Pavia (Italy); Bruschi, P. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Protti, N.; Santoro, D.; Stella, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute for Nuclear Physics (INFN), Section of Pavia, Pavia (Italy); Cansolino, L.; Clerici, A.; Ferrari, C.; Zonta, A.; Zonta, C. [Department of Experimental Surgery, University of Pavia, Pavia (Italy); Altieri, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute for Nuclear Physics (INFN), Section of Pavia, Pavia (Italy)

    2012-03-01

    A selective uptake of boron in the tumor is the base of Boron Neutron Capture Therapy, which can destroy the tumor substantially sparing the normal tissue. In order to deliver a lethal dose to the tumor, keeping the dose absorbed by normal tissues below the tolerance level, it is mandatory to know the {sup 10}B concentration present in each kind of tissue at the moment of irradiation. This work presents the calibration procedure adopted for a boron concentration measurement method based on neutron autoradiography, where biological samples are deposited on sensitive films and irradiated in the thermal column of the TRIGA reactor (University of Pavia). The latent tracks produced in the film by the charged particles coming from the neutron capture in {sup 10}B are made visible by a proper etching, allowing the measurement of the track density. A calibration procedure with standard samples provides curves of track density as a function of boron concentration, to be used in the measurement of biological samples. In this paper, the bulk etch rate parameter and the calibration curves obtained for both liquid samples and biological tissues with known boron concentration are presented. A bulk etch rate value of (1.64 {+-} 0.02) {mu}m/h and a linear dependence with etching time were found. The plots representing the track density versus the boron concentration in a range between 5 and 50 {mu}g/g (ppm) are linear, with an angular coefficient of (1.614 {+-} 0.169){center_dot}10{sup -3} tracks/({mu}m{sup 2} ppm) for liquids and (1.598 {+-} 0.097){center_dot}10{sup -2} tracks/({mu}m{sup 2} ppm) for tissues.

  19. Capacitance of Nanoporous Carbon-Based Supercapacitors Is a Trade-Off between the Concentration and the Separability of the Ions.

    Science.gov (United States)

    Burt, Ryan; Breitsprecher, Konrad; Daffos, Barbara; Taberna, Pierre-Louis; Simon, Patrice; Birkett, Greg; Zhao, X S; Holm, Christian; Salanne, Mathieu

    2016-10-06

    Nanoporous carbon-based supercapacitors store electricity through adsorption of ions from the electrolyte at the surface of the electrodes. Room temperature ionic liquids, which show the largest ion concentrations among organic liquid electrolytes, should in principle yield larger capacitances. Here, we show by using electrochemical measurements that the capacitance is not significantly affected when switching from a pure ionic liquid to a conventional organic electrolyte using the same ionic species. By performing additional molecular dynamics simulations, we interpret this result as an increasing difficulty of separating ions of opposite charges when they are more concentrated, that is, in the absence of a solvent that screens the Coulombic interactions. The charging mechanism consistently changes with ion concentration, switching from counterion adsorption in the diluted organic electrolyte to ion exchange in the pure ionic liquid. Contrarily to the capacitance, in-pore diffusion coefficients largely depend on the composition, with a noticeable slowing of the dynamics in the pure ionic liquid.

  20. Coupling Front-End Separations, Ion Mobility Spectrometry, and Mass Spectrometry For Enhanced Multidimensional Biological and Environmental Analyses

    Science.gov (United States)

    Zheng, Xueyun; Wojcik, Roza; Zhang, Xing; Ibrahim, Yehia M.; Burnum-Johnson, Kristin E.; Orton, Daniel J.; Monroe, Matthew E.; Moore, Ronald J.; Smith, Richard D.; Baker, Erin S.

    2017-01-01

    Ion mobility spectrometry (IMS) is a widely used analytical technique for rapid molecular separations in the gas phase. Though IMS alone is useful, its coupling with mass spectrometry (MS) and front-end separations is extremely beneficial for increasing measurement sensitivity, peak capacity of complex mixtures, and the scope of molecular information available from biological and environmental sample analyses. In fact, multiple disease screening and environmental evaluations have illustrated that the IMS-based multidimensional separations extract information that cannot be acquired with each technique individually. This review highlights three-dimensional separations using IMS-MS in conjunction with a range of front-end techniques, such as gas chromatography, supercritical fluid chromatography, liquid chromatography, solid-phase extractions, capillary electrophoresis, field asymmetric ion mobility spectrometry, and microfluidic devices. The origination, current state, various applications, and future capabilities of these multidimensional approaches are described in detail to provide insight into their uses and benefits. PMID:28301728

  1. Coupling Front-End Separations, Ion Mobility Spectrometry, and Mass Spectrometry For Enhanced Multidimensional Biological and Environmental Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Xueyun; Wojcik, Roza; Zhang, Xing; Ibrahim, Yehia M.; Burnum-Johnson, Kristin E.; Orton, Daniel J.; Monroe, Matthew E.; Moore, Ronald J.; Smith, Richard D.; Baker, Erin M.

    2017-06-12

    Ion mobility spectrometry (IMS) is a widely used analytical technique for rapid molecular separations in the gas phase. IMS alone is useful, but its coupling with mass spectrometry (MS) and front-end separations has been extremely beneficial for increasing measurement sensitivity, peak capacity of complex mixtures, and the scope of molecular information in biological and environmental sample analyses. Multiple studies in disease screening and environmental evaluations have even shown these IMS-based multidimensional separations extract information not possible with each technique individually. This review highlights 3-dimensional separations using IMS-MS in conjunction with a range of front-end techniques, such as gas chromatography (GC), supercritical fluid chromatography (SFC), liquid chromatography (LC), solid phase extractions (SPE), capillary electrophoresis (CE), field asymmetric ion mobility spectrometry (FAIMS), and microfluidic devices. The origination, current state, various applications, and future capabilities for these multidimensional approaches are described to provide insight into the utility and potential of each technique.

  2. Concentration of uranium-235 in mixtures with uranium-238 using ion exchange resins

    International Nuclear Information System (INIS)

    Seko, M.; Kakihana, H.

    1976-01-01

    A method is described of simultaneously obtaining separate enriched fractions of 235 U and 238 U from isotopic mixtures thereof with the use of an ion exchange column by passing a liquid body containing the isotopic mixture through the column. The uranium as it is passed through the column is presented as a U(IV) coordination compound with a ligand at different valent states and is followed by an eluant and forms a band which travels through the column, the front and rear portions of which are respectively enriched in one of the isotopes and depleted in the other. 16 claims

  3. Concentration of uranium-235 in mixtures with uranium-238 using ion exchange resins

    International Nuclear Information System (INIS)

    Seko, M.; Kakihana, H.

    1976-01-01

    A method is described for simultaneously obtaining separate enriched fractions of 235 U and 238 U from isotopic mixtures of these with the use of an ion exchange column by passing a liquid body containing the isotopic mixture through the column. The uranium as it is passed through the column is present as a U(IV) coordination compound with a ligand at different valent states and is followed by an eluant and forms a band which travels through the column, the front and rear portions of which are respectively enriched in one of the isotopes and depleted in the other. 16 claims, no drawings

  4. Method for the concentration and separation of actinides from biological and environmental samples

    International Nuclear Information System (INIS)

    Horwitz, E.P.; Dietz, M.L.

    1989-01-01

    A method and apparatus for the quantitative recover of actinide values from biological and environmental sample by passing appropriately prepared samples in a mineral acid solution through a separation column of a dialkyl(phenyl)-N,N-dialylcarbamoylmethylphosphine oxide dissolved in tri-n-butyl phosphate on an inert substrate which selectively extracts the actinide values. The actinide values can be eluted either as a group or individually and their presence quantitatively detected by alpha counting. 3 figs

  5. Determination of element concentrations in biological reference materials by solid sampling and other analytical methods

    International Nuclear Information System (INIS)

    Schauenburg, H.; Weigert, P.

    1992-01-01

    Using solid sampling with graphite furnace atomic absorption spectrometry (GFAAS), values for cadmium, copper, lead and zinc in six biological reference materials were obtained from up to four laboratories participating in three collaborative studies. These results are compared with those obtained with other methods used in routine analysis from laboratories of official food control. Under certain conditions solid sampling with GFAAS seems to be suitable for routine analysis as well as conventional methods. (orig.)

  6. The association effect of human serum albumin under different zinc ion concentrations studied by small angle of neutron scattering

    International Nuclear Information System (INIS)

    He Jian; Xu Yanping; Yang Tonghua; He Jintian; Li Lianzhi; Zhou Yongqia

    1997-01-01

    The microscopic parameters of the HSA-Zn 2+ , R g and I(0), are obtained directedly by small angle of neutron scattering (SANS) under different concentrations of zinc ion. Comparing with other relevant experimental results, e.g. equilibrium dialysis, we can determine and distinguish the apparent interactive subsequences into more detailed sub-actions, such as self-association, inter-association, disintegration and deconformation et al., or even certain combination of them, other than some indirect and microscopic results. Results obtained by SANS can qualitatively and readily interpret the characteristics from the viewpoint of microscopic process

  7. The trial of obtaining a high-grade gadolinium concentrate using the fractional precipitation together with the ion exchange

    International Nuclear Information System (INIS)

    Ozga, W.; Soltysiak, I.

    1980-01-01

    The modified fractional precipitation of lanthanon-potassium double chromate was used for preliminary separation of gadolinium concentrate containing 60% Gd 2 O 3 , 33,3% Sm 2 O 3 . The 1-st fraction enriched with samarium (60% Sm 2 O 3 ) and 2-nd fraction enriched with gadolinium (80% Gd 2 O 3 with efficiency of 82% recounting on Gd 2 O 3 ) were obtained. Both fractions were separated by the elution with EDTA solution buffered with ammonium acetate. The good results were obtained by ion exchange separation only of the 1-st fraction. (author)

  8. The FLUKA Monte Carlo code coupled with the local effect model for biological calculations in carbon ion therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mairani, A [University of Pavia, Department of Nuclear and Theoretical Physics, and INFN, via Bassi 6, 27100 Pavia (Italy); Brons, S; Parodi, K [Heidelberg Ion Beam Therapy Center and Department of Radiation Oncology, Im Neuenheimer Feld 450, 69120 Heidelberg (Germany); Cerutti, F; Ferrari, A; Sommerer, F [CERN, 1211 Geneva 23 (Switzerland); Fasso, A [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Kraemer, M; Scholz, M, E-mail: Andrea.Mairani@mi.infn.i [GSI Biophysik, Planck-Str. 1, D-64291 Darmstadt (Germany)

    2010-08-07

    Clinical Monte Carlo (MC) calculations for carbon ion therapy have to provide absorbed and RBE-weighted dose. The latter is defined as the product of the dose and the relative biological effectiveness (RBE). At the GSI Helmholtzzentrum fuer Schwerionenforschung as well as at the Heidelberg Ion Therapy Center (HIT), the RBE values are calculated according to the local effect model (LEM). In this paper, we describe the approach followed for coupling the FLUKA MC code with the LEM and its application to dose and RBE-weighted dose calculations for a superimposition of two opposed {sup 12}C ion fields as applied in therapeutic irradiations. The obtained results are compared with the available experimental data of CHO (Chinese hamster ovary) cell survival and the outcomes of the GSI analytical treatment planning code TRiP98. Some discrepancies have been observed between the analytical and MC calculations of absorbed physical dose profiles, which can be explained by the differences between the laterally integrated depth-dose distributions in water used as input basic data in TRiP98 and the FLUKA recalculated ones. On the other hand, taking into account the differences in the physical beam modeling, the FLUKA-based biological calculations of the CHO cell survival profiles are found in good agreement with the experimental data as well with the TRiP98 predictions. The developed approach that combines the MC transport/interaction capability with the same biological model as in the treatment planning system (TPS) will be used at HIT to support validation/improvement of both dose and RBE-weighted dose calculations performed by the analytical TPS.

  9. US Subseabed Disposal Program radioecological data base: summaries of available radionuclide concentration factors and biological half-lives

    International Nuclear Information System (INIS)

    Gomez, L.S.; Marietta, M.G.; Jackson, D.W.

    1984-01-01

    The US Subseabed Disposal Program has compiled an extensive objective concentration factor and biological half-life data base from the international marine radioecological literature. A microcomputer-based data management system has been implemented to provide statistical and graphical summaries of these data. The data base is constructed in a manner which allows subsets to be sorted using a number of inter-study variables such as organism category, tissue/organ category, geographic location (for in situ studies), and several laboratory-related conditions (e.g., exposure time and exposure concentration). We discuss concentration factor data summaries for many elements. We also discuss summary material for biological half-life data. We discuss the results of our review with the estimates of mean concentration factors provided by the IAEA. It is proposed that this presentation scheme will enable those concerned with predictive assessment of radiation dose in the marine environment to make a more judicious selection of data for a given application. 7 references

  10. Effects of lead on Na+, K+-ATPase and hemolymph ion concentrations in the freshwater mussel Elliptio complanata

    Science.gov (United States)

    Mosher, Shad; Cope, W. Gregory; Weber, Frank X.; Shea, Damian; Kwak, Thomas J.

    2012-01-01

    Freshwater mussels are an imperiled fauna exposed to a variety of environmental toxicants such as lead (Pb) and studies are urgently needed to assess their health and condition to guide conservation efforts. A 28-day laboratory toxicity test with Pb and adult Eastern elliptio mussels (Elliptio complanata) was conducted to determine uptake kinetics and to assess the toxicological effects of Pb exposure. Test mussels were collected from a relatively uncontaminated reference site and exposed to a water-only control and five concentrations of Pb (as lead nitrate) ranging from 1 to 245 mu g/L in a static renewal test with a water hardness of 42 mg/L. Endpoints included tissue Pb concentrations, hemolymph Pb and ion (Na+, K+, Cl-, Ca2+) concentrations, and Na+, K+-ATPase enzyme activity in gill tissue. Mussels accumulated Pb rapidly, with tissue concentrations increasing at an exposure-dependent rate for the first 2 weeks, but with no significant increase from 2 to 4 weeks. Mussel tissue Pb concentrations ranged from 0.34 to 898 mu g/g dry weight, were strongly related to Pb in test water at every time interval (7, 14, 21, and 28 days), and did not significantly increase after day 14. Hemolymph Pb concentration was variable, dependent on exposure concentration, and showed no appreciable change with time beyond day 7, except for mussels in the greatest exposure concentration (245 mu g/L), which showed a significant reduction in Pb by 28 days, suggesting a threshold for Pb binding or elimination in hemolymph at concentrations near 1000 mu g/g. The Na+, K+-ATPase activity in the gill tissue of mussels was significantly reduced by Pb on day 28 and was highly correlated with tissue Pb concentration (R2 = 0.92; P = 0.013). The Na+, K+-ATPase activity was correlated with reduced hemolymph Na+ concentration at the greatest Pb exposure when enzyme activity was at 30% of controls. Hemolymph Ca2+ concentration increased significantly in mussels from the greatest Pb exposure and may

  11. Concentration dependent spectroscopic properties of Dy{sup 3+} ions doped boro-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Mariyappan, M.; Marimuthu, K., E-mail: mari-ram2000@yahoo.com [Department of Physics, Gandhigram Rural Institute - Deemed University, Gandhigram – 624 302 (India)

    2016-05-23

    Dy{sup 3+} ions doped boro-phosphate glasses have been synthesized by melt quenching method and characterized through FTIR, absorption and luminescence spectral measurements. The presence of various stretching and bending vibrations of different borate and phosphate groups were identified from the FTIR spectra. In order to examine the electronic band structure of the studied glasses, Optical energy gap (E{sub opt}) and Urbach energy (ΔE) values were estimated from the absorption spectra. The Judd-Ofelt (JO) intensity parameters were calculated to examine the symmetry of the ligand environment around the Dy{sup 3+} ions site. The emission spectra exhibit two intense emission bands at around 482 nm (blue) and 574 nm (yellow) corresponding to the {sup 4}F{sub 9/2}→{sup 6}H{sub 15/2} and {sup 4}F{sub 9/2}→{sup 6}H{sub 13/2} transitions respectively. The emission spectra were characterized through Commission International d’Eclairage (CIE) 1931 chromaticity diagram to explore its suitability for WLED applications.

  12. Particulate sulfate ion concentration and SO2 emission trends in the United States from the early 1990s through 2010

    Directory of Open Access Journals (Sweden)

    W. C. Malm

    2012-11-01

    Full Text Available We examined particulate sulfate ion concentrations across the United States from the early 1990s through 2010 using remote/rural data from the Interagency Monitoring of Protected Visual Environments (IMPROVE network and from early 2000 through 2010 using data from the Environmental Protection Agency's (EPA urban Chemical Speciation Network (CSN. We also examined measured sulfur dioxide (SO2 emissions from power plants from 1995 through 2010 from the EPA's Acid Rain Program. The 1992–2010 annual mean sulfate concentrations at long-term rural sites in the United States have decreased significantly and fairly consistently across the United States at a rate of −2.7% yr−1 (p −1 (p −1 (p 2 emissions from power plants across the United States have decreased at a similar rate as sulfate concentrations from 2001 to 2010 (−6.2% yr−1, p 2 emissions and average sulfate concentrations. This linearity was strongest in the eastern United States and weakest in the West where power plant SO2 emissions were lowest and sulfate concentrations were more influenced by non-power-plant and perhaps international SO2 emissions. In addition, annual mean, short-term sulfate concentrations decreased more rapidly in the East relative to the West due to differences in seasonal trends at certain regions in the West. Specifically, increased wintertime concentrations in the central and northern Great Plains and increased springtime concentrations in the western United States were observed. These seasonal and regional positive trends could not be explained by changes in known local and regional SO2 emissions, suggesting other contributing influences. This work implies that on an annual mean basis across the United States, air quality mitigation strategies have been successful in reducing the particulate loading of sulfate in the atmosphere; however, for certain seasons and regions, especially in the West, current mitigation strategies appear insufficient.

  13. Effect of europium ion concentration on the structural and photoluminescence properties of novel Li2BaZrO4: Eu3+ nanocrystals

    Science.gov (United States)

    Ahemen, I.; Dejene, F. B.; Kroon, R. E.; Swart, H. C.

    2017-12-01

    This work reports the influence of Eu3+ ion concentration on the structure and photoluminescence properties of Li2BaZrO4 nanocrystals including its intrinsic quantum efficiency (IQE). Chemical bath method was employed in the synthesis procedure. X-ray diffraction results showed tetragonal phase for Eu3+ ion concentration in the range 1 and 7 mol% and cubic phase at 8 mol%. The presence of barium oxide (BaO) was confirmed from selected area electron diffraction (SAED). The excitation spectra for these phosphors consisted of broad charge transfer (CT) bands due to the combination of Zr4+ - O2- and Eu3+-O2- charge transfer states. Superimposed on the CT band were direct excitation levels of Eu3+ and Ba2+ ions, in the range 320-450 nm. At high Eu3+ ions concentrations, the intensities of CT bands decreased because some of the ions were coordinated with Ba2+ ions. Photoluminescence emissions for all the doped samples at room temperature appeared to be entirely from intraconfigurational Eu3+ emissions and depended both on the site symmetry as well as the ion concentration. The quadrupole-quadrupole multipolar process was found to be solely responsible for the luminescence quenching. The intensity parameters (Ω2 ,Ω4), asymmetry ratio, R0 and the average decay lifetime of the nanocrystals showed dependence on concentration. High internal quantum efficiency (IQE) values were obtained at low Eu3+ ion concentrations, but efficiency decreased with increasing ion concentration. The CIE coordinates values were comparable to existing red phosphors and in combination with the high IQE make this phosphor a good candidate for red light emitting applications.

  14. Ion mobility spectrometry as a simple and rapid method to measure the plasma propofol concentrations for intravenous anaesthesia monitoring

    Science.gov (United States)

    Wang, Xin; Zhou, Qinghua; Jiang, Dandan; Gong, Yulei; Li, Enyou; Li, Haiyang

    2016-11-01

    The plasma propofol concentration is important information for anaesthetists to monitor and adjust the anaesthesia depth for patients during a surgery operation. In this paper, a stand-alone ion mobility spectrometer (IMS) was constructed for the rapid measurement of the plasma propofol concentrations. Without any sample pre-treatment, the plasma samples were dropped on a piece of glass microfiber paper and then introduced into the IMS cell by the thermal desorption directly. Each individual measurement could be accomplished within 1 min. For the plasma propofol concentrations from 1 to 12 μg mL-1, the IMS response was linear with a correlation coefficient R2 of 0.998, while the limit of detection was evaluated to be 0.1 μg mL-1. These measurement results did meet the clinical application requirements. Furthermore, other clinically-often-used drugs, including remifentanil, flurbiprofen and atracurium, were found no significant interference with the qualitative and quantitative analysis of the plasma propofol. The plasma propofol concentrations measured by IMS were correlated well with those measured by the high performance liquid chromatography (HPLC). The results confirmed an excellent agreement between these two methods. Finally, this method was applied to monitor the plasma propofol concentrations for a patient undergoing surgery, demonstrating its capability of anaesthesia monitoring in real clinical environments.

  15. Evaluation of the biological effect of the concentration of ''CMU''on the leaves plant breeding

    International Nuclear Information System (INIS)

    Revilla Pedreira, R.

    1980-01-01

    The effect of CMU (3-p-chlorophenyl)-1,1-dimethylurea on the photosynthetic activity of six species of higher plants and on chlorella pyrenoidosa was studied. In the higher plants the absorption of CMU was studied using 14 C-CMU. The effect of different concentrations of this herbicide on the photosynthetic assimilation of CO 2 by the plant's leaves has also been determined. Moreover, the inhibitory effect of the CMU on the Hill reaction of isolated chloroplasts has been studied. The results indicate that there is a correlation between the concentration of the herbicide and the degree of inhibition of photosynthesis for concentration between 10 -8 M and 10 -4 M. As a consequence of the results obtained, a biotest is proposed for the detection of residues of the photosynthesis inhibitors using the alga chlorella pyrenoidosa as the sensory element. (auth.)

  16. The specific ion effect on emulsions, foam and gels of a seed protein concentrate

    International Nuclear Information System (INIS)

    Lawal, O.S.

    2008-05-01

    Protein concentrate was prepared from the seeds of jack bean (Canavalia ensiformis) and the influences of selected Hofmeister salts on some functional properties of the protein concentrate were investigated. The results indicate that kosmotropic salts (Na 2 SO 4 , NaCl, NaBr) had improved water absorption capacities over the chaotropic salts (NaI, NaClO 4 , NaSCN) and generally, the reduction in water absorption capacity followed the Hofmeister trend: Na 2 SO 4 > NaCl > NaBr > NaI > NaClO 4 > NaSCN. However, the reverse was observed for the foaming and emulsification properties. The least gelation concentration (LGC) was used as the index of gelation properties and the results showed that LGC were higher in kosmotropic salts than in chaotropic salts. Generally, increases in salt concentration reduced the water absorption capacity, the surfactant properties as well as the gelation property. The findings would provide insight into the understanding of the structure property relations of the protein concentrate. (author)

  17. Relative Biological Effectiveness of HZE Fe Ions for Induction ofMicro-Nuclei at Low Doses

    Energy Technology Data Exchange (ETDEWEB)

    Groesser, Torsten; Chun, Eugene; Rydberg, Bjorn

    2007-01-16

    Dose-response curves for induction of micro-nuclei (MN) was measured in Chinese hamster V79 and xrs6 (Ku80-) cells and in human mammary epithelial MCF10A cells in the dose range of 0.05-1 Gy. The Chinese Hamster cells were exposed to 1 GeV/u Fe ions, 600 MeV/u Fe ions, and 300 MeV/u Fe ions (LETs of 151, 176 and 235 keV/{micro}m respectively) as well as with 320 kVp X-rays as reference. Second-order polynomials were fitted to the induction curves and the initial slopes (the alpha values) were used to calculate RBE. For the repair proficient V79 cells the RBE at these low doses increased with LET. The values obtained were 3.1 (LET=151 keV/{micro}m), 4.3 (LET = 176 keV/{micro}m) and 5.7 (LET = 235 keV/{micro}m), while the RBE was close to 1 for the repair deficient xrs6 cells regardless of LET. For the MCF10A cells the RBE was determined for 1 GeV/u Fe ions and found to be 5.4, slightly higher than for V79 cells. To test the effect of shielding, the 1 GeV/u Fe ion beam was intercepted by various thickness of high-density polyethylene plastic absorbers, which resulted in energy loss and fragmentation. It was found that the MN yield for V79 cells placed behind the absorbers decreased in proportion to the decrease in dose both before and after the Fe ion Bragg peak (excluding the area around the Fe-ion Bragg peak itself), indicating that RBE did not change significantly due to shielding. At the Bragg peak the effectiveness for MN formation per unit dose was decreased, indicating an 'overkill' effect by low-energy very high-LET Fe ions.

  18. Heavy cosmic ions with charge Z = 3q-40 and their biological implications

    International Nuclear Information System (INIS)

    Hasegan, D.; Dudkin, E.V.; Marenny, M.A.

    1979-01-01

    Heavy cosmic ions were studied by plastic detectors flown in cosmic space aboard the artificial Earth satellites COSMOS 690, 782 and 936. Charge spectra in the range of Z = 3q-40 of cosmic nuclei having energy E >= 1 GeV/nucleon are presented. LET spectra of heavy cosmic ions were measured in these experiments, as well as the LET variation inside the stacks of plastic detectors. The variation of the irreversible inactivation cross sections and the Fractional Cell Loss with depth are derived. Three-dimensional energy deposition around the trajectories of the particles, in the studied ranges of charges and energies, is computed using Katz's model. (author)

  19. Additional transport channel of carbon ions for biological research at the Nuclotron of JINR

    International Nuclear Information System (INIS)

    Yudin, I.P.; Panasik, V.A.; Tyutyunnikov, S.I.

    2011-01-01

    The paper deals with the construction of the 12 C +6 beam transport line for biomedical research at the Nuclotron accelerator complex, JINR. We have studied the scheme and modes of magneto-optical elements of the channel. The results of calculations of the investigated beam transport of carbon ions are presented. The algorithms to control the carbon ion beam in the transportation system are discussed. The choice of the magneto-optical system is motivated. The graphs of the beam envelopes in the channel are given. The scanning control beam functions are considered

  20. Additional transport channel of carbon ions for biological research at the Nuclotron of JINR

    International Nuclear Information System (INIS)

    Yudin, I.P.; Panasik, V.A.; Tyutyunnikov, S.I.

    2012-01-01

    The paper deals with the construction of the beam 12 C +6 transport line for biomedical research at the Nuclotron accelerator complex, JINR. We have studied the scheme and modes of magneto-optical elements of the channel. The results of calculations of the investigated beam transport of carbon ions are presented. The algorithms to control the carbon ion beam in the transportation system are discussed. The choice of the magneto-optical system is motivated. The graphs of the beam envelopes in the channel are given. The scanning control beam functions are considered

  1. A Sensitive Cell-Based Assay to Measure the Doxycycline Concentration in Biological Samples

    NARCIS (Netherlands)

    Kleibeuker, Wendy; Zhou, Xue; Centlivre, Mireille; Legrand, Nicolas; Page, Mark; Almond, Neil; Berkhout, Ben; Das, Atze T.

    2009-01-01

    Doxycycline (DOX) is widely used as a pharmacological agent and as an effector molecule in inducible gene expression systems. For most applications, it is important to determine whether the DOX concentration reaches the level required for optimal efficacy. We developed a sensitive bioassay for

  2. Compilation of elemental concentration data for NBS Biological and Environmental Standard Reference Materials

    International Nuclear Information System (INIS)

    Gladney, E.S.

    1980-07-01

    Concentration data on up to 76 elementals in 19 NBS Standard Reference Materials have been collected from 325 journal articles and technical reports. These data are summarized into mean +- one standard deviation values and compared with available data from NBS and other review articles. Data are presented on the analytical procedures employed and all raw data are presented in appendixes

  3. Biological phosphorus and nitrogen removal in sequencing batch reactors: effects of cycle length, dissolved oxygen concentration and influent particulate matter.

    Science.gov (United States)

    Ginige, Maneesha P; Kayaalp, Ahmet S; Cheng, Ka Yu; Wylie, Jason; Kaksonen, Anna H

    2013-01-01

    Removal of phosphorus (P) and nitrogen (N) from municipal wastewaters is required to mitigate eutrophication of receiving water bodies. While most treatment plants achieve good N removal using influent carbon (C), the use of influent C to facilitate enhanced biological phosphorus removal (EBPR) is poorly explored. A number of operational parameters can facilitate optimum use of influent C and this study investigated the effects of cycle length, dissolved oxygen (DO) concentration during aerobic period and influent solids on biological P and N removal in sequencing batch reactors (SRBs) using municipal wastewaters. Increasing cycle length from 3 to 6 h increased P removal efficiency, which was attributed to larger portion of N being removed via nitrite pathway and more biodegradable organic C becoming available for EBPR. Further increasing cycle length from 6 to 8 h decreased P removal efficiencies as the demand for biodegradable organic C for denitrification increased as a result of complete nitrification. Decreasing DO concentration in the aerobic period from 2 to 0.8 mg L(-1) increased P removal efficiency but decreased nitrification rates possibly due to oxygen limitation. Further, sedimented wastewater was proved to be a better influent stream than non-sedimented wastewater possibility due to the detrimental effect of particulate matter on biological nutrient removal.

  4. Ultraviolet Laser Damage Dependence on Contamination Concentration in Fused Silica Optics during Reactive Ion Etching Process

    Directory of Open Access Journals (Sweden)

    Laixi Sun

    2018-04-01

    Full Text Available The reactive ion etching (RIE process of fused silica is often accompanied by surface contamination, which seriously degrades the ultraviolet laser damage performance of the optics. In this study, we find that the contamination behavior on the fused silica surface is very sensitive to the RIE process which can be significantly optimized by changing the plasma generating conditions such as discharge mode, etchant gas and electrode material. Additionally, an optimized RIE process is proposed to thoroughly remove polishing-introduced contamination and efficiently prevent the introduction of other contamination during the etching process. The research demonstrates the feasibility of improving the damage performance of fused silica optics by using the RIE technique.

  5. Investigation on degradation mechanism of ion exchange membrane immersed in highly concentrated tritiated water under the Broader Approach Activities

    Energy Technology Data Exchange (ETDEWEB)

    Iwai, Yasunori, E-mail: iwai.yasunori@jaea.go.jp; Sato, Katsumi; Yamanishi, Toshihiko

    2014-10-15

    Highlights: • Endurance of Nafion ion exchange membrane immersed into 1.38 × 10{sup 12} Bq/kg of highly concentrated tritiated water has been demonstrated. • The formation of free hydrophobic free products by reactions between radicals on the membrane and oxygen caused the decrease in ionic conductivity. • From the {sup 19}F NMR spectrum, no distinctive degradation in the membrane structure by interaction with tritium was measured. - Abstract: The ion exchange membrane is a key material for electrolysis cells of the water detritiation system. Durability of ion exchange membrane has been demonstrated under the Broader Approach Activities. Long-term exposure of Nafion{sup ®} ion exchange membrane in 1.38 × 10{sup 12} Bq/kg of tritiated water was conducted at room temperature for up to 2 years. The ionic conductivity of Nafion{sup ®} membrane after immersed in tritiated water was changed. The change in color of membrane from colorless to yellowish was caused by reactions of radicals on the polymer and oxygen molecules in air. Infrared Fourier transform spectrum of a yellowish membrane revealed a small peak for bending vibration of C-H situated at 1437 cm{sup −1}, demonstrating the formation of hydrophobic functional group in the membrane. The hydrophilic network in Nafion{sup ®} membrane was partially obstructed by the hydrophobic free products. This caused the decrease in ionic conductivity. The peak for bending vibration was clearly eliminated in the spectrum of the membrane after treatment by acid for removal of free products. The high-resolution solid state {sup 19}F NMR spectrum of a membrane after immersed in tritiated water was similar to that of a membrane irradiated with gamma-rays. From the {sup 19}F NMR spectrum, no distinctive degradation in the membrane structure by interaction with tritium was measured.

  6. Mixed moderate thermophilic bioleaching of Cu, Mo and Re from molybdenite concentrate: effects of silver ion, medium and energy sources

    Directory of Open Access Journals (Sweden)

    Hadi Abdollahi

    2017-12-01

    Full Text Available This study evaluates the effects of different additives such as silver ion, medium and energy sources on the efficiency of mixed moderate thermophilic bioleaching approach to extract Cu, Mo and Re from molybdenite concentrate containing 0.98% Cu, 1.56% Fe, 53.84% Mo, and 0.055% Re. Molybdenite was the major phase of Mo-bearing mineral and chalcopyrite, covellite and pyrite were distinguished as minor phases. The higher copper extraction was obtained in tests with silver additives in all types and quantities rather than tests without silver ion. Kinetic of copper dissolution varied in these experiments and depended on the types and amounts of silver, and other supplemented additives such as ferric ion. There was no clear difference in the copper extraction by various culture media and 100% of Cu was dissolved after 30 days of treatment, using 50 mg/L of silver nitrate as additives. In the best condition and without silver additives, maximum 60% of copper was extracted even in the presence of energy sources such as sulfur, ferrous and ferric ions. In the most effective test with initial pH 1.57, 50 mg/L silver nitrate, and 50 g/L ferric sulfate, 100% of copper was dissolved in less than a week with highest kinetics rate. Molybdenum and rhenium extraction had the same tends with redox potential graph. By increasing the redox potential to the 550-600mV, molybdenite started to dissolve and finally, molybdenum and rhenium were extracted 2% and 9.53% in the best condition; respectively.

  7. Investigation on degradation mechanism of ion exchange membrane immersed in highly concentrated tritiated water under the Broader Approach Activities

    International Nuclear Information System (INIS)

    Iwai, Yasunori; Sato, Katsumi; Yamanishi, Toshihiko

    2014-01-01

    Highlights: • Endurance of Nafion ion exchange membrane immersed into 1.38 × 10 12 Bq/kg of highly concentrated tritiated water has been demonstrated. • The formation of free hydrophobic free products by reactions between radicals on the membrane and oxygen caused the decrease in ionic conductivity. • From the 19 F NMR spectrum, no distinctive degradation in the membrane structure by interaction with tritium was measured. - Abstract: The ion exchange membrane is a key material for electrolysis cells of the water detritiation system. Durability of ion exchange membrane has been demonstrated under the Broader Approach Activities. Long-term exposure of Nafion ® ion exchange membrane in 1.38 × 10 12 Bq/kg of tritiated water was conducted at room temperature for up to 2 years. The ionic conductivity of Nafion ® membrane after immersed in tritiated water was changed. The change in color of membrane from colorless to yellowish was caused by reactions of radicals on the polymer and oxygen molecules in air. Infrared Fourier transform spectrum of a yellowish membrane revealed a small peak for bending vibration of C-H situated at 1437 cm −1 , demonstrating the formation of hydrophobic functional group in the membrane. The hydrophilic network in Nafion ® membrane was partially obstructed by the hydrophobic free products. This caused the decrease in ionic conductivity. The peak for bending vibration was clearly eliminated in the spectrum of the membrane after treatment by acid for removal of free products. The high-resolution solid state 19 F NMR spectrum of a membrane after immersed in tritiated water was similar to that of a membrane irradiated with gamma-rays. From the 19 F NMR spectrum, no distinctive degradation in the membrane structure by interaction with tritium was measured

  8. Analysis of cocaine and its metabolites from biological specimens using solid-phase extraction and positive ion chemical ionization mass spectrometry.

    Science.gov (United States)

    Crouch, D J; Alburges, M E; Spanbauer, A C; Rollins, D E; Moody, D E

    1995-10-01

    An accurate and reliable gas chromatographic-mass spectrometric method was developed to analyze tissue, whole blood, plasma, and urine samples for cocaine (COC) and its major metabolites. COC, benzoylecgonine (BZE), and ecgonine methyl ester (EME) were isolated from the biological matrix using solid-phase extraction, and the tert-butyldimethylsilyl derivatives of BZE, EME, and their deuterium-labeled internal standards were formed. Separation of the compounds was performed by capillary chromatography, and analysis was performed by positive ion chemical ionization mass spectrometry using methane and ammonia as the reagent gases. The tert-butyldimethylsilyl derivatives of BZE and EME were stable and produced mass spectral ions with higher mass-to-charge ratios than trimethylsilyl derivatives. Recovery of COC and its metabolites exceeded 80% at all three concentrations tested. Linearity of the method was established from 2.5 to 2000 microg/L. Intra-assay precision had a coefficient of variation (CV) of less than 9% for all analytes when tested at 10, 25, 100, and 200 microg/L. Interassay precision also had a CV of less than 9% for COC, BZE, and EME at 25 and 100 microg/L. At 200 microg/L, %CVs for COC, BZE, and EME were 11.5, 12.0, and 12.7, respectively. In addition to the analysis of COC, BZE, and EME, the method was used to quantitate cocaethylene and to identify norcocaine.

  9. Developing on-site paper colorimetric monitoring technique for quick evaluating copper ion concentration in mineral wastewater

    Science.gov (United States)

    Liu, Guokun; Peng, Jingji; Zheng, Hong; Yuan, Dongxing

    2018-05-01

    With the reinforce of the copper mining, the on-site monitoring of the accompanied effluent discharge is highly demanded for the emergency response to minimize the negative effect of the effluent on the surrounding ecosystem. On the basis of the specific interaction between Cu2+ and L-Cysteine (L-Cys), which was modified on gold nanoparticles (Au NPs), and the aggregation dependent surface plasmon resonance (SPR) of Au NPs, we developed an easy-on-going paper colorimetric method for the quick evaluating the copper ion concentration in the waste water excreted from the copper mine. The color change of L-Cys modified Au NPs (L-Cys-Au NPs)immobilized on a filter paper was very sensitive to the Cu2+ concentration and free of interference from other metal ions typically in waste water. The proposed paper colorimetry has the LOD of 0.09 mg/L and the linear range of 0.1-10 mg/L, respectively, with the RSD (n = 5) was 6.6% for 1 mg/L Cu2+ and 3.5% for 5 mg/L Cu2+. The quantitative analysis results for the mineral wastewater is in good agreement the China National Environmental Protection Standards HJ485-2009, which indicates the current method could be developed to the on-site detection technique for the emergency response in monitoring Cu2+ in industrial wastewater or polluted water.

  10. Measurement of excitation, ionization, and electron temperatures and positive ion concentrations in a 144 MHz inductively coupled radiofrequency plasma

    International Nuclear Information System (INIS)

    Walters, P.E.; Chester, T.L.; Winefordner, J.D.

    1977-01-01

    Diagnostic measurements of 144 MHz radiofrequency inductively coupled plasmas at pressures between 0.5 and 14 Torr have been made. Other variables studied included the gas type (Ar or Ne) and material in plasma (Ti or Tl). Parameters measured included excitation temperatures via the atomic Boltzmann plot and the two-line method, ionization electric probes. Excitation temperatures increased as the pressure of Ar or Ne plasmas decreased and reached a maximum of approx.9000 degreeK in the latter case and approx.6700 degreeK in the former case; Tl in the Ar plasma resulted in in a smaller rate of decrease of excitation temperature with increase of pressure of Ar. The ionization temperatures were lower than the excitation temperatures and were similar for both the Ar and Ne plasmas. Electron temperatures were about 10 times higher than the excitation temperatures indicating non-LTE behavior. Again, the electron temperatures indicating in Ne were considerably higher than in Ar. With the presence of metals, the electron temperatures with a metal in the Ar plasma were higher than in the absence. Positive ion concentrations were also measured for the various plasmas and were found to be similar (approx.10 18 m -3 ) in both the Ar and Ne plasmas. The presence of metals caused significant increase in the positive ion concentrations. From the results obtained, the optimum Ar pressure for Tl electrodeless discharge lamps operated at 144 MHz would be between 2 and 4 Torr

  11. Beyond the Hofmeister Series: Ion-Specific Effects on Proteins and Their Biological Functions

    Czech Academy of Sciences Publication Activity Database

    Okur, H. I.; Hladílková, Jana; Rembert, K. B.; Cho, Y.; Heyda, J.; Dzubiella, J.; Cremer, P. S.; Jungwirth, Pavel

    2017-01-01

    Roč. 121, č. 9 (2017), s. 1997-2014 ISSN 1520-6106 R&D Projects: GA ČR(CZ) GA16-01074S Institutional support: RVO:61388963 Keywords : Hofmeister series * ions * proteins * molecular dynamics Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 3.177, year: 2016

  12. Derivatization chemistry of the double-decker dicobalt sandwich ion targeted to design biologically active substances

    Czech Academy of Sciences Publication Activity Database

    Grüner, Bohumír; Švec, Petr; Hájková, Zuzana; Císařová, I.; Pokorná, Jana; Konvalinka, Jan

    2012-01-01

    Roč. 84, č. 11 (2012), s. 2243-2262 ISSN 0033-4545 R&D Projects: GA AV ČR IAAX00320901 Institutional support: RVO:61388980 ; RVO:61388963 Keywords : AIDS treatment * boranes * canastide ion * carboranes * dicarbollides * HIV -protease Subject RIV: CA - Inorganic Chemistry Impact factor: 3.386, year: 2012

  13. Automation of a battery of ion exchange columns for the determination of Pu in biological samples

    International Nuclear Information System (INIS)

    Jeanmaire, L.; Ballada, J.; Rigaudiere, R.; Patti, F.; Clanet, F.

    1967-01-01

    The document describes an apparatus allowing ten automatic and simultaneous determination of plutonium by ion exchange resins in urine. The constant flow rate reactants supply is realized by plastic siphons. The different determination phases are controlled by a programmer. (A.L.B.) [fr

  14. The importance of biological factors affecting trace metal concentration as revealed from accumulation patterns in co-occurring terrestrial invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickx, Frederik; Maelfait, Jean-Pierre; Bogaert, Nicolas; Tojal, Catarina; Du Laing, Gijs; Tack, Filip M.G.; Verloo, Marc G

    2004-02-01

    As physicochemical properties of the soil highly influence the bioavailable fraction of a particular trace metal, measured metal body burdens in a particular species are often assumed to be more reliable estimators of the contamination of the biota. To test this we compared the Cd, Cu and Zn content of three spiders (generalist predators) and two amphipods (detritivores), co-occurring in seven tidal marshes along the river Schelde, between each other and with the total metal concentrations and the concentrations of four sequential extractions of the soils. Correlations were significant in only one case and significant sitexspecies interactions for all metals demonstrate that factors affecting metal concentration were species and site specific and not solely determined by site specific characteristics. These results emphasize that site and species specific biological factors might be of the utmost importance in determining the contamination of the biota, at least for higher trophic levels. A hypothetical example clarifies these findings. - Site and species specific biological factors are important in determining contamination of biota.

  15. Electrochemical oxidation of biological pretreated and membrane separated landfill leachate concentrates on boron doped diamond anode

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Bo, E-mail: 357436235@qq.com [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Yu, Zhiming, E-mail: zhiming@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Wei, Qiuping, E-mail: qiupwei@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Long, HangYu, E-mail: 55686385@qq.com [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Xie, Youneng, E-mail: 1187272844@qq.com [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Wang, Yijia, E-mail: 503630433@qq.com [School of Materials Science and Engineering, Central South University, Changsha 410083 (China)

    2016-07-30

    Highlights: • High quality boron-doped diamond film electrodes were synthesized on Nb substrates. • Electrochemical oxidation on boron-doped diamond anode is an effective method for treating landfill leachate concentrates. • Optimal operating conditions for electrochemical oxidation of landfill leachate concentrates is determined. • 87.5% COD removal and 74.06% NH{sub 3}−N removal were achieved after 6 h treatment. - Abstract: In the present study, the high quality boron-doped diamond (BDD) electrodes with excellent electrochemical properties were deposited on niobium (Nb) substrates by hot filament chemical vapor deposition (HFCVD) method. The electrochemical oxidation of landfill leachate concentrates from disc tube reverse osmosis (DTRO) process over a BDD anode was investigated. The effects of varying operating parameters, such as current density, initial pH, flow velocity and cathode material on degradation efficiency were also evaluated following changes in chemical oxygen demand (COD) and ammonium nitrogen (NH{sub 3}−N). The instantaneous current efficiency (ICE) was used to appraise different operating conditions. As a result, the best conditions obtained were as follows, current density 50 mA cm{sup −2}, pH 5.16, flow velocity 6 L h{sup −1}. Under these conditions, 87.5% COD and 74.06% NH{sub 3}−N removal were achieved after 6 h treatment, with specific energy consumption of 223.2 kWh m{sup −3}. In short, these results indicated that the electrochemical oxidation with BDD/Nb anode is an effective method for the treatment of landfill leachate concentrates.

  16. Research on electrochemical methods for concentration measurement of dissolved ion in molten salt to apply to electrolytic process control. Innovative research adopted in 2002 fiscal year

    International Nuclear Information System (INIS)

    Nagai, Takayuki

    2005-03-01

    The purpose of this research is to establish the online (in-situ) technique for concentration measuring of dissolved ion in the molten salt, and this technique is due to the electrochemical method for the concentration measuring of dissolved ion in solutions like the polarization curve measurement. This research executed the following four items. 1) Examination of possibility for concentration measuring of dissolved ion in molten salt by cyclic voltammetry. 2) Examination of possibility for concentration measuring of dissolved ion in molten salt by various electrochemical methods. 3) Examination of suitable electrochemical method for concentration measuring of dissolved ion. 4) Confirmation of selected electrochemical method for concentration measuring of dissolved ion. It has been understood that the differential pulse voltammetry (DPV) is a promising electrochemical technique for the concentration measuring of dissolved ion in the molten salt as a result of this research. An appropriate measurement condition is as follows, the potential sweep rate is -0.1 V/s, the pulse cycle is 0.1 s, the pulse width is 10 ms, and the pulse voltage is 50 mV. As for the electrodes, the platinum working electrode, the glassy carbon counter electrode, and silver/silver chloride reference electrode are suitable. Moreover, the molar absorptivities of U 3+ , U 4+ , UO 2 + , UO 2 2+ , and the standard redox potentials of couples of U 4+ /U 3+ and UO 2 2+ /UO 2 + were acquired as a basic data of the uranium and the uranyl ion in molten NaCl-2CsCl. (author)

  17. Mineralization Process of Biocemented Sand and Impact of Bacteria and Calcium Ions Concentrations on Crystal Morphology

    Directory of Open Access Journals (Sweden)

    Guobin Xu

    2017-01-01

    Full Text Available Microbial-induced calcite precipitation (MICP is a sustainable technique used to improve sandy soil. Analysis of the mineralization process, as well as different bacterial suspensions and calcium concentrations on the crystal morphology, revealed that the mineralization process included four stages: self-organised hydrolysis of microorganisms, molecular recognition and interface interaction, growth modulation, and epitaxial growth. By increasing bacterial suspensions and calcium concentrations, the crystal morphology changed from hexahedron to oblique polyhedron to ellipsoid; the best crystal structure occurs at OD600 = 1.0 and [Ca2+] = 0.75 mol/l. It should be noted that interfacial hydrogen bonding is the main force that binds the loose sand particles. These results will help in understanding the mechanism of MICP.

  18. The use of Na+ and K+ ion concentrations as potential diagnostic indicators of subclinical mastitis in dairy cows

    Directory of Open Access Journals (Sweden)

    Abdul Wahid Haron

    2014-11-01

    Full Text Available Aim: This study was conducted to evaluate the concentrations of sodium (Na+ and potassium (K+ ions in milk of lactating dairy cows with and without subclinical mastitis as putative indicators for detecting subclinical mastitis in dairy cows. Materials and Methods: Thirty seven lactating dairy cows were screened for the evidence of subclinical mastitis using California mastitis test (CMT. The lactating dairy cows were categorized as CMT-Positive (CMT-P; n=20 and CMT-Negative (CMT-N; n=17 based on whether they were positive or negative for CMT using a standard kit. The CMT-P lactating dairy cows were further sub divided into subclinical 1+ (S1+; n=6, subclinical 2+ (S2+; n=9, and subclinical 3+(S3+; n=5. Direct microscopy somatic cell count (SCC was used to determine the SCC using Wright’s stain. The samples were filtered and diluted at 1:100 dilutions before being measured for the concentrations of Na+ and K+ using atomic absorption spectrophotometer. Results: There was a significant increase (p<0.05 in SCCs and Na+ concentration in the milk of CMT-P dairy cows, with a mean Log10 SCC score of 5.35±0.06 cells/ml and mean Na+ concentration of 232±19.1 mg/dL. However, there was a significant reduction (p<0.05 in the concentration of K+ (123±7.6 mg/dL in the milk samples of the CMT-P cows. There were significant differences (p<0.05 in SCC, Na+ and K+ concentrations between milk samples from the CMT-N dairy cows and CMT-P subgroups; S1+, S2+, and S3+ respectively. Potassium (K+ concentration had a significant strong negative correlation with sodium (Na+ concentration (r=−0.688; p<0.01 and weak positive correlation with SCC (r=−0.436; p<0.01. The sensitivity of using Na+ and K+ concentrations as detection indices for sub-clinical mastitis is 40% and 90%, respectively, while the specificity of each was 100%. Conclusion: This study thus shows that evaluation of Na+ and K+ concentrations from milk samples of dairy cows with sub clinical mastitis

  19. Fast vaporization solid phase microextraction and ion mobility spectrometry: A new approach for determination of creatinine in biological fluids.

    Science.gov (United States)

    Jafari, Mostafa; Ebrahimzadeh, Homeira; Banitaba, Mohamma Hossein

    2015-11-01

    In this work a rapid and simple method for creatinine determination in urine and plasma samples based on aqueous derivatization of creatinine and complete vaporization of sample (as low as 10 µL), followed by ion mobility spectrometry analysis has been proposed. The effect of four important parameters (extraction temperature, total volume of solution, desorption temperature and extraction time) on ion mobility signal has been studied. Under the optimized conditions, the quantitative response of ion mobility spectrometry for creatinine was linear in the range of 0-500 mg L(-1) with a detection limit of 0.6 mg L(-1) in urine and 0-250 mg L(-1) with a detection limit of 2.6 mg L(-1) in plasma sample. The limit of quantitation of creatinine was 2.1 mg L(-1) and 8.7 mg L(-1) in urine and plasma samples, respectively. The relative standard deviation of the method was found to be 13%. The method was successfully applied to the analysis of creatinine in biological samples, showing recoveries from 92% to 104% in urine and 101-110% in plasma samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Accurate determination of trace amounts of lanthanum, yttrium and all stable lanthanides in biological materials by Ion Chromatography

    International Nuclear Information System (INIS)

    Dybczynski, R.S.; Kulisa, K.; Danko, B.; Samczynski, Z.

    2007-01-01

    The analytical procedure for the isolation and preconcentration of La, Y and the lanthanides from biological materials and their determination by ion chromatography (IC) with the use of Dionex Ion Pac CS3 + CG3 column (sulfonic acid type), α-hydroxyisobutyric acid (α-HIBA) as an eluent, and PAR or Arsenazo III as color forming reagents, was elaborated. The scheme originally devised for NAA, involving microwave assisted digestion and multi step separation employing ion exchange and extraction chromatography columns was used to selectively recover REE fraction (without scandium) with 100% yield. The REE fraction was analyzed by IC at 25 and 70 o C. The run at 70 o C enabled resolution of Y and Dy peaks and as a result made possible quantitative determination of La, Y, and all lanthanides. Investigation on the mechanism of band spreading revealed that longitudinal diffusion in the stationary phase considerably contributed to the total plate height. Surprisingly, the plate height (H) calculated from Y peak was distinctly lower than H values of the adjacent lanthanides. The method was validated by analyzing several certified reference materials (CRMs). (authors)

  1. The FLUKA Monte Carlo code coupled with the local effect model for biological calculations in carbon ion therapy

    CERN Document Server

    Mairani, A; Kraemer, M; Sommerer, F; Parodi, K; Scholz, M; Cerutti, F; Ferrari, A; Fasso, A

    2010-01-01

    Clinical Monte Carlo (MC) calculations for carbon ion therapy have to provide absorbed and RBE-weighted dose. The latter is defined as the product of the dose and the relative biological effectiveness (RBE). At the GSI Helmholtzzentrum fur Schwerionenforschung as well as at the Heidelberg Ion Therapy Center (HIT), the RBE values are calculated according to the local effect model (LEM). In this paper, we describe the approach followed for coupling the FLUKA MC code with the LEM and its application to dose and RBE-weighted dose calculations for a superimposition of two opposed C-12 ion fields as applied in therapeutic irradiations. The obtained results are compared with the available experimental data of CHO (Chinese hamster ovary) cell survival and the outcomes of the GSI analytical treatment planning code TRiP98. Some discrepancies have been observed between the analytical and MC calculations of absorbed physical dose profiles, which can be explained by the differences between the laterally integrated depth-d...

  2. Evaluation of Metal Ion Concentration in Hard Tissues of Teeth in Residents of Central Poland

    Directory of Open Access Journals (Sweden)

    Piotr Wychowanski

    2017-01-01

    Full Text Available Objectives. The aim of the study was an assessment of the content of trace elements in enamel and dentin of teeth extracted in patients residing in urban and agricultural areas of Poland. Methods. The study included 30 generally healthy patients with retained third molars. 65 samples of enamel and dentin from individuals living in urban areas and 85 samples of enamel and dentin from individuals living in agricultural areas were prepared. The content of manganese, lead, cadmium, and chromium in the studied enamel and dentin samples from retained teeth was determined by Graphite Furnace Atomic Absorption Spectrometry. In the process of statistical hypothesis testing, the level of significance was assumed at α=0.05. Results. A comparative analysis of the data showed that enamel and dentin of inhabitants of industrialized areas contain significantly higher amounts of lead and cadmium than hard tissues of teeth in residents of agricultural areas and comparable amounts of manganese and chromium. Significance. It appears that hard tissues of retained teeth may constitute valuable material for assessment of long-term environmental exposure to metal ions. The study confirms that the risk of exposure to heavy metals depends on the place of residence and environmental pollution.

  3. WE-H-BRA-09: Application of a Modified Microdosimetric-Kinetic Model to Analyze Relative Biological Effectiveness of Ions Relevant to Light Ion Therapy Using the Particle Heavy Ion Transport System

    Energy Technology Data Exchange (ETDEWEB)

    Butkus, M [Yale-New Haven Hospital, New Haven, CT (United States); Palmer, T [Oregon State University, Corvallis, OR (United States)

    2016-06-15

    Purpose: To evaluate the dose and biological effectiveness of various ions that could potentially be used for actively scanned particle therapy. Methods: The PHITS Monte Carlo code paired with a microscopic analytical function was used to determine probability distribution functions of the lineal energy in 0.3µm diameter spheres throughout a water phantom. Twenty million primary particles for 1H beams and ten million particles for 4He, 7Li, 10B, 12C, 14N, 16O, and 20Ne were simulated for 0.6cm diameter pencil beams. Beam energies corresponding to Bragg peak depths of 50, 100, 150, 200, 250, and 300mm were used and evaluated transversely every millimeter and radially in annuli with outer radius of 1.0, 2.0, 3.0, 3.2, 3.4, 3.6, 4.0, 5.0, 10.0, 15.0, 20.0 and 25.0mm. The acquired probability distributions were reduced to dose-mean lineal energies and applied to the modified microdosimetric kinetic model for five different cell types to calculate relative biological effectiveness (RBE) compared to 60Co beams at the 10% survival threshold. The product of the calculated RBEs and the simulated physical dose was taken to create biological dose and comparisons were then made between the various ions. Results: Transversely, the 10B beam was seen to minimize relative biological dose in both the constant and accelerated dose change regions, proximal to the Bragg Peak, for all beams traveling greater than 50mm. For the 50mm beam, 7Li was seen to provide the most optimal biological dose profile. Radially small fluctuations (<4.2%) were seen in RBE while physical dose was greater than 1% for all beams. Conclusion: Even with the growing usage of 12C, it may not be the most optimal ion in all clinical situations. Boron was calculated to have slightly enhanced RBE characteristics, leading to lower relative biological doses.

  4. Improved Technique for the Determination of Uranium Minor Isotopes Concentrations in Microparticles by Using Secondary Ion Mass-Spectrometer in Multicollection Mode

    International Nuclear Information System (INIS)

    Aleshin, M.; Elantyev, I.; Stebelkov, Y.

    2015-01-01

    Traditional method of the analysis implies simultaneous measuring of secondary ion currents of isotopes 234U + , 235U + , 238U + , ions with mass 236 amu (236U + and 235UH + ) and hydride ions 238UH + by using mass-spectrometer Cameca IMS1280 in multicollection mode. Calculating of uranium isotopic composition is performed using the results of 40 successive measurements of those currents (cycles). Duration of each measurement is 8 s. Small amounts of uranium minor isotopes are limitation for precise determination of their concentrations. To prevent the damage of the secondary ions detector the intensity of ion current should be no more than 5 x 10 5 s -1 . This limitation does not allow setting a higher primary ion current for the increasing of minor uranium isotopes ions emission because of the signal of ions 238U + gets too high. New technique is developed to improve the accuracy of determination of uranium minor isotopes concentrations. Process of measurement is divided on two steps. First step is a measurement of ion currents during 20 cycles by five detectors. The second step implies the elimination of ions 238U + hitting to the detector and 10 times increasing of primary ion current. The ratio 235U/238U is calculated from the first step results, so uncertainty of determination of this value is 1.4 times bigger than with duration of 40 cycles of the measurement. The ratios 234U/235U and 236U/235U are calculated during the second step. This technique allows to determine content of 234U and 236U with 3 and 5 times less uncertainties respectively, but with different degree of the sputtering particles. Moreover the duration of each cycle was set less (1 second) to use data more efficient. The technique accordingly with every second counting provides uncertainty of determination 236U concentration 4 times less than traditional method at the same degree of sputtering particles. (author)

  5. Element concentrations in candidate biological and environmental reference materials by k0-standardized INAA

    International Nuclear Information System (INIS)

    Freitas, M.C.

    1993-01-01

    K 0 -Based Neutron Activation Analysis (k 0 INAA) was used to analyze the candidate reference materials Apple Leaves and Peach Leaves, and Oriental Tobacco Leaves and Virginia Tobacco Leaves. Concentration values for 27 elements were measured. The accuracy was ascertained by analysis of two certified reference materials. NIST 1572 Citrus Leaves and 1573 Tomato Leaves. The homogeneity test of the IAEA Evernia prunastri candidate reference material in aliquots ≥ 100 mg is extended to the elements Sc, Cr, Fe, Co, Zn, Rb, Sb, Cs, Ba, Ce and Th. (orig.)

  6. Analysis of movements of both specific activity of tritium and concentration of each ion in short-term precipitation at typhoons

    International Nuclear Information System (INIS)

    Yamada, Ryuta; Watanabe, Minami; Ying, Wang; Kataoka, Noriaki; Morita, Syogo; Imaizumi, Hiroshi; Kano, Naoki

    2015-01-01

    Both the specific activity of tritium and the concentration of several ions(Na + , K + , Mg 2+ , Ca 2+ , Cl - , NO 3 - , SO 4 2- ) in precipitation at typhoons in Niigata city, Japan were measured, and the following matters were found as to precipitation at typhoon. (1) Specific activities of tritium at typhoons were under the average of the activities in precipitation in the same month. (2) The specific activity of tritium depends on that whether the precipitation was sampled after the several days from the last rain, or not so long. (3) Movements of these ion concentrations in precipitation are similar to each other except nitrate ion. (4) Each ion concentration ratio in precipitation at a typhoon became to be similar to that in sea with time. (5) Using relative compositional ratio of sampled water to sea water defined in this research, the effect of sea water on precipitation can be revealed. (author)

  7. A semi-analytical model of biological effectiveness for treatment planning in light ion radiotherapy

    Czech Academy of Sciences Publication Activity Database

    Kundrát, Pavel

    2007-01-01

    Roč. 34, č. 6 (2007), s. 2654-2654 ISSN 0094-2405. [AAPM Annual Meeting. Minneapolis, 22.07.2007-26.07.2007] R&D Projects: GA ČR GA202/05/2728 Institutional research plan: CEZ:AV0Z10100502 Keywords : treatment planning * light-ion therapy * radiobiological models Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.198, year: 2007

  8. Effect of Fe ion concentration on fatigue life of carbon steel in aqueous CO2 environment

    DEFF Research Database (Denmark)

    Rogowska, Magdalena; Gudme, J.; Rubin, A.

    2016-01-01

    situ measurements of Fe2+ and pH. Characterisation of the corrosion scales and crack formations was performed using microscopic and diffraction techniques. Fatigue results showed two times better fatigue life, at the stress ranges of 250 MPa, for samples tested in solutions containing the concentration...... of Fe2+ marginally above the solubility limit of FeCO3 compared to the samples tested in highly supersaturated solution of Fe2+. Results revealed that the impact of the alternating stresses on the corrosion behaviour of samples reduces with lowering the applied stresses. At the stress range of 100 MPa...

  9. Ag ion irradiated based sensor for the electrochemical determination of epinephrine and 5-hydroxytryptamine in human biological fluids

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, Rajendra N., E-mail: rngcyfcy@iitr.ernet.in [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Agrawal, Bharati [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667 (India)

    2012-09-19

    Highlights: Black-Right-Pointing-Pointer Ag ions irradiation enhances the electrocatalytic activity of carbon nano tubes. Black-Right-Pointing-Pointer The low fluence of irradiation caused the ordering of carbon nano tubes. Black-Right-Pointing-Pointer Simultaneous determination of epinephrine and 5-hydroxytryptamine has been carried out. Black-Right-Pointing-Pointer The determination of the neurotransmitters in human blood and urine is reported. - Abstract: A promising and highly sensitive voltammetric method has been developed for the first time for the determination of epinephrine (EP) and 5-hydroxytryptamine (5-HT) using 120 MeV Ag ion irradiated multi-walled carbon nano tube (MWCNT) based sensor. The MWCNT were irradiated at various fluences of 1e12, 3e12 and 1e13 ions cm{sup -2} using palletron accelerator. The simultaneous determination of EP and 5-HT has been carried out in phosphate buffer solution of pH 7.20 using square wave voltammetry and cyclic voltammetry. Experimental results suggested that irradiation of MWCNT by Ag ions enhanced the electrocatalytic activity due to increase in effective surface area and insertion of Ag ions, leading to a remarkable enhancement in peak currents and shift of peak potentials to less positive values as compared to the unirradiated MWCNT (pristine). The developed sensor exhibited a linear relationship between peak current and concentration of EP and 5-HT in the range 0.1-105 {mu}M with detection limit (3{sigma}/b) of 2 nM and 0.75 nM, respectively. The practical utility of irradiation based MWCNT sensor has been demonstrated for the determination of EP and 5-HT in human urine and blood samples.

  10. Simulation of biological ion channels with technology computer-aided design.

    Science.gov (United States)

    Pandey, Santosh; Bortei-Doku, Akwete; White, Marvin H

    2007-01-01

    Computer simulations of realistic ion channel structures have always been challenging and a subject of rigorous study. Simulations based on continuum electrostatics have proven to be computationally cheap and reasonably accurate in predicting a channel's behavior. In this paper we discuss the use of a device simulator, SILVACO, to build a solid-state model for KcsA channel and study its steady-state response. SILVACO is a well-established program, typically used by electrical engineers to simulate the process flow and electrical characteristics of solid-state devices. By employing this simulation program, we have presented an alternative computing platform for performing ion channel simulations, besides the known methods of writing codes in programming languages. With the ease of varying the different parameters in the channel's vestibule and the ability of incorporating surface charges, we have shown the wide-ranging possibilities of using a device simulator for ion channel simulations. Our simulated results closely agree with the experimental data, validating our model.

  11. Angiotensin-I converting enzyme (ACE): structure, biological roles, and molecular basis for chloride ion dependence.

    Science.gov (United States)

    Masuyer, Geoffrey; Yates, Christopher J; Sturrock, Edward D; Acharya, K Ravi

    2014-10-01

    Somatic angiotensin-I converting enzyme (sACE) has an essential role in the regulation of blood pressure and electrolyte fluid homeostasis. It is a zinc protease that cleaves angiotensin-I (AngI), bradykinin, and a broad range of other signalling peptides. The enzyme activity is provided by two homologous domains (N- and C-), which display clear differences in substrate specificities and chloride activation. The presence of chloride ions in sACE and its unusual role in activity was identified early on in the characterisation of the enzyme. The molecular mechanisms of chloride activation have been investigated thoroughly through mutagenesis studies and shown to be substrate-dependent. Recent results from X-ray crystallography structural analysis have provided the basis for the intricate interactions between ACE, its substrate and chloride ions. Here we describe the role of chloride ions in human ACE and its physiological consequences. Insights into the chloride activation of the N- and C-domains could impact the design of improved domain-specific ACE inhibitors.

  12. Combined ion exchange / biological denitrification for nitrate removal from ground water

    NARCIS (Netherlands)

    Hoek, van der J.P.

    1988-01-01

    This thesis deals with the development of a new process for nitrate removal from ground water. High nitrate concentrations in ground water are a result of fertilization in agriculture. According to a directive of the European Community the maximum admissible concentration of nitrate in

  13. MAK and BAT values list 2014. Maximum permissible concentrations at the place of work and biological tolerance values for working materials

    International Nuclear Information System (INIS)

    2014-01-01

    The book on the MAK (maximum permissible concentrations at the place of work) and BAT (biological tolerance values for working materials) value list 2014 includes the following chapters: (a) Maximum permissible concentrations at the place of work: definition, application and determination of MAT values, list of materials; carcinogenic working materials, sensibilizing working materials, aerosols, limiting the exposition peaks, skin resorption, MAK values during pregnancy, germ cell mutagens, specific working materials; (b) Biological tolerance values for working materials: definition and application of BAT values, list of materials, carcinogenic working materials, biological guide values, biological working material reference values.

  14. MAK and BAT values list 2015. Maximum permissible concentrations at the place of work and biological tolerance values for working materials

    International Nuclear Information System (INIS)

    2015-01-01

    The book on the MAK (maximum permissible concentrations at the place of work) and BAT (biological tolerance values for working materials) value list 2015 includes the following chapters: (a) Maximum permissible concentrations at the place of work: definition, application and determination of MAT values, list of materials; carcinogenic working materials, sensibilizing working materials, aerosols, limiting the exposition peaks, skin resorption, MAK values during pregnancy, germ cell mutagens, specific working materials; (b) Biological tolerance values for working materials: definition and application of BAT values, list of materials, carcinogenic working materials, biological guide values, biological working material reference values.

  15. Ion chromatography separation of lanthanides at trace concentrations from Gd Matrix and quantification by ICP-MS

    International Nuclear Information System (INIS)

    Raut, V.V.; Jeyakumar, S.; Nagar, B.K.; Deb, S.B.; Saxena, M.K.; Tomar, B.S.

    2014-01-01

    Gadolinium compounds are mainly used as burnable poison. The presence of certain impurities is undesirable in the nuclear grade Gd compounds. Gd 2 O 3 , a most common raw material used for the preparation of nuclear grade Gd compounds. Analysis of rare earth impurities in Gd-matrices is one of the important exercises carried out to ensure the purity of Gd 2 O 3 . Determination of lanthanides at trace concentrations in lanthanide (Gd) matrix is complicated and difficult to realize. This is because the selective separation of REE's in one of the lanthanide elements is a challenging task. The present study was carried out to explore the feasibility of separating trace level lanthanides from Gd matrix by ion interaction chromatography (IIC) and to develop an analytical methodology for the determination of lanthanides by inductively coupled plasma mass spectrometry (ICP-MS). In the present investigation, the reversed phase column was dynamically modified into sulphonic acid functionalized surface by using 0.025 M n-Octane sulphonic acid (OSA). With α-HIBA eluent system, the elution order follows as Lu to La. The separations are employed with gradient elution mode. Since the sample has large excess of Gd, elution profiles with concentration gradient of HIBA were attempted. Separated fractions of Light lanthanides (LLn) and Heavy lanthanides (HLn) were collected and analyzed by ICP-MS. During MS analysis, it was observed that due to high concentration of salt (Na salt of OSA) present in the collected fractions caused difficulty in ICP-MS . Hence the experiments were carried out using another ion interacting reagent viz. 0.03 M camphor-10-sulphonic acid (CSA). Initial concentration of HIBA was kept at 0.025 M up to 15 min for the elution of HLns i.e. from Lu to Tb and it was then increased to 0.05 M to 0.3 M in 30 min. After elution of Tb, outlet of the column was switched to drain for 7 min to separate bulk Gd fraction. From 22 to 35 min effluent fraction containing Eu

  16. Long-range Transported African Dust in the Caribbean Region: Dust Concentrations and Water-soluble Ions

    Science.gov (United States)

    Santos-Figueroa, G.; Avilés-Piñeiro, G. M.; Mayol-Bracero, O. L.

    2017-12-01

    Long-range transported African dust (LRTAD) particles reach the Caribbean region every year during the summer months causing an increase in PM10 concentrations and by consequence degradation of air quality. During African dust (AD) incursions at the Caribbean region, PM10 concentration could exceeds the exposure limit of 50 µg/m³ 24-hour mean established by the World Health Organization (WHO). To have a better understanding of the impacts of AD particles to climate and public health at the Caribbean region it is necessary to study and determine the spatial and temporal distribution of dust particles. In order to address this, aerosols samples were collected during and absence of AD incursions during the summer of 2017 using a Hi-Volume (Hi-Vol) sampler for total suspended particles (TSP) at two sampling stations in Puerto Rico. The first station is a marine site located at Cabezas de San Juan (CSJ) Nature Reserve in Fajardo, and the second station is an urban site located at the Facundo Bueso (FB) building at the University of Puerto Rico-Rio Piedras. Aerosol samples were collected using Whatman 41 grade filters from which we determined the concentration of dust particles and the water-soluble ions (e.g., Na+, NH4+, Ca+2, Cl-, SO4-2) in the presence and absence of LRTAD particles. Saharan Air Layer (SAL) imagery, the results from the air mass backward trajectories calculated with the NOAA Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT), and the spectral coefficients from measurements at CSJ were used to monitor and confirm the presence of air masses coming from North Africa. Average dust concentrations using the Stacked-Filter Units (SFUs) at CSJ are around 4 μg/m3. LRTAD concentrations and ionic speciation results using the Hi-Vol for the marine and urban sites will be presented at the conference.

  17. Low acetate concentrations favor polyphosphate-accumulating organisms over glycogen-accumulating organisms in enhanced biological phosphorus removal from wastewater.

    Science.gov (United States)

    Tu, Yunjie; Schuler, Andrew J

    2013-04-16

    Glycogen-accumulating organisms (GAOs) are thought to compete with polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) wastewater treatment systems. A laboratory sequencing batch reactor (SBR) was operated for one year to test the hypothesis that PAOs have a competitive advantage at low acetate concentrations, with a focus on low pH conditions previously shown to favor GAOs. PAOs dominated the system under conventional SBR operation with rapid acetate addition (producing high in-reactor concentrations) and pH values of 7.4-8.4. GAOs dominated when the pH was decreased (6.4-7.0). Decreasing the acetate addition rate led to very low reactor acetate concentrations, and PAOs recovered, supporting the study hypothesis. When the acetate feed rate was increased, EBPR failed again. Dominant PAOs and GAOs were Candidatus Accumulibacter phosphatis and Defluviicoccus Cluster 2, respectively, according to fluorescent in situ hybridization and 454 pyrosequencing. Surprisingly, GAOs were not the immediate causes of PAO failures, based on functional and population measurements. Pyrosequencing results suggested Dechloromonas and Tetrasphaera spp. may have also been PAOs, and additional potential GAOs were also identified. Full-scale systems typically have lower in-reactor acetate concentrations than laboratory SBRs, and so, previous laboratory studies may have overestimated the practical importance of GAOs as causes of EBPR failure.

  18. Luminescent passive-oxidized silicon quantum dots as biological staining labels and their cytotoxicity effects at high concentration

    International Nuclear Information System (INIS)

    Fujioka, Kouki; Manabe, Noriyoshi; Hanada, Sanshiro; Hoshino, Akiyoshi; Yamamoto, Kenji; Hiruoka, Masaki; Sato, Keisuke; Hirakuri, Kenji; Miyasaka, Ryosuke; Tilley, Richard D; Manome, Yoshinobu

    2008-01-01

    Semiconductor quantum dots (QDs) hold some advantages over conventional organic fluorescent dyes. Due to these advantages, they are becoming increasingly popular in the field of bioimaging. However, recent work suggests that cadmium based QDs affect cellular activity. As a substitute for cadmium based QDs, we have developed photoluminescent stable silicon quantum dots (Si-QDs) with a passive-oxidation technique. Si-QDs (size: 6.5 ± 1.5 nm) emit green light, and they have been used as biological labels for living cell imaging. In order to determine the minimum concentration for cytotoxicity, we investigated the response of HeLa cells. We have shown that the toxicity of Si-QDs was not observed at 112 μg ml -1 and that Si-QDs were less toxic than CdSe-QDs at high concentration in mitochondrial assays and with lactate dehydrogenase (LDH) assays. Especially under UV exposure, Si-QDs were more than ten times safer than CdSe-QDs. We suggest that one mechanism for the cytotoxicity is that Si-QDs can generate oxygen radicals and these radicals are associated with membrane damages. This work has demonstrated the suitability of Si-QDs for bioimaging in lower concentration, and their cytotoxicity and one toxicity mechanism at high concentration

  19. Mapping the Galvanic Corrosion of Three Coupled Metal Alloys Using Coupled Multielectrode Array: Influence of Chloride Ion Concentration

    Directory of Open Access Journals (Sweden)

    Hong Ju

    2018-04-01

    Full Text Available The galvanic corrosion behavior of three metal alloys commonly used in water desalination plants was investigated using coupled multielectrode arrays consisting of aluminum-brass (HAl77-2, titanium alloy (TA2, and 316L stainless steel (316L SS. The three electrode types were coupled galvanically and arranged in different geometric configurations. Their corrosion behavior was characterized as a function of the chloride concentration. The potential and current distributions of the three-electrode coupling systems display electrochemical inhomogeneity. Generally, the aluminum-brass wires are anodic versus the titanium alloy and stainless steel. The titanium alloy acts as a primary cathode, and the 316L SS acts as a secondary cathode. The corrosion rate of aluminum-brass depends on the concentration of chloride ion, with a maximum corrosion rate at a chloride concentration of 2.3 wt %. In terms of geometrical arrangements, when the anodic HAl77-2 wires are located on the edge and are connected to the 316L SS wires in the coupling system, the main anodic area enlarges, especially in the area adjacent to the 316L SS wires. When the HAl77-2 wires are located between (in the middle of the two other types of wires, the corrosion rates are higher than the corrosion rates observed from the other two geometrical arrangements.

  20. Mapping the Galvanic Corrosion of Three Coupled Metal Alloys Using Coupled Multielectrode Array: Influence of Chloride Ion Concentration.

    Science.gov (United States)

    Ju, Hong; Duan, JinZhuo; Yang, Yuanfeng; Cao, Ning; Li, Yan

    2018-04-20

    The galvanic corrosion behavior of three metal alloys commonly used in water desalination plants was investigated using coupled multielectrode arrays consisting of aluminum-brass (HAl77-2), titanium alloy (TA2), and 316L stainless steel (316L SS). The three electrode types were coupled galvanically and arranged in different geometric configurations. Their corrosion behavior was characterized as a function of the chloride concentration. The potential and current distributions of the three-electrode coupling systems display electrochemical inhomogeneity. Generally, the aluminum-brass wires are anodic versus the titanium alloy and stainless steel. The titanium alloy acts as a primary cathode, and the 316L SS acts as a secondary cathode. The corrosion rate of aluminum-brass depends on the concentration of chloride ion, with a maximum corrosion rate at a chloride concentration of 2.3 wt %. In terms of geometrical arrangements, when the anodic HAl77-2 wires are located on the edge and are connected to the 316L SS wires in the coupling system, the main anodic area enlarges, especially in the area adjacent to the 316L SS wires. When the HAl77-2 wires are located between (in the middle of) the two other types of wires, the corrosion rates are higher than the corrosion rates observed from the other two geometrical arrangements.

  1. Concentration and characteristics of depleted uranium in water, air and biological samples collected in Serbia and Montenegro

    International Nuclear Information System (INIS)

    Jia Guogang; Belli, Maria; Sansone, Umberto; Rosamilia, Silvia; Gaudino, Stefania

    2005-01-01

    During the Balkan conflicts, in 1995 and 1999, depleted uranium (DU) rounds were employed and were left in the battlefield. Health concern is related to the risk arising from contamination of the environment with DU penetrators and dust. In order to evaluate the impact of DU on the environment and population in Serbia and Montenegro, radiological surveys of DU in water, air and biological samples were carried out over the period 27 October-5 November 2001. The uranium isotopic concentrations in biological samples collected in Serbia and Montenegro, mainly lichens and barks, were found to be in the range of 0.67-704 Bq kg -1 for 238 U, 0.48-93.9 Bq kg -1 for 234 U and 0.02-12.2 Bq kg -1 for 235 U, showing uranium levels to be higher than in the samples collected at the control sites. Moreover, 236 U was detectable in some of the samples. The isotopic ratios of 234 U/ 238 U showed DU to be detectable in many biological samples at all examined sites, especially in Montenegro, indicating widespread ground-surface DU contamination, albeit at very low level. The uranium isotopic concentrations in air obtained from the air filter samples collected in Serbia and Montenegro were found to be in the range of 1.99-42.1 μBq m -3 for 238 U, 0.96-38.0 μBq m -3 for 234 U, and 0.05-1.83 μBq m -3 for 235 U, being in the typical range of natural uranium values. Thus said, most of the air samples are DU positive, this fact agreeing well with the widespread DU contamination detected in the biological samples. The uranium concentrations in water samples collected in Serbia and Montenegro were found to be in the range of 0.40-21.9 mBq l -1 for 238 U, 0.27-28.1 mBq l -1 for 234 U, and 0.01-0.88 mBq l -1 for 235 U, these values being much lower than those in mineral water found in central Italy and below the WHO guideline for drinking water. From a radiotoxicological point of view, at this moment there is no significant radiological risk related to these investigated sites in terms of

  2. Concentration and characteristics of depleted uranium in water, air and biological samples collected in Serbia and Montenegro.

    Science.gov (United States)

    Jia, Guogang; Belli, Maria; Sansone, Umberto; Rosamilia, Silvia; Gaudino, Stefania

    2005-09-01

    During the Balkan conflicts, in 1995 and 1999, depleted uranium (DU) rounds were employed and were left in the battlefield. Health concern is related to the risk arising from contamination of the environment with DU penetrators and dust. In order to evaluate the impact of DU on the environment and population in Serbia and Montenegro, radiological surveys of DU in water, air and biological samples were carried out over the period 27 October-5 November 2001. The uranium isotopic concentrations in biological samples collected in Serbia and Montenegro, mainly lichens and barks, were found to be in the range of 0.67-704 Bqkg(-1) for (238)U, 0.48-93.9 Bqkg(-1) for (234)U and 0.02-12.2 Bqkg(-1) for (235)U, showing uranium levels to be higher than in the samples collected at the control sites. Moreover, (236)U was detectable in some of the samples. The isotopic ratios of (234)U/(238)U showed DU to be detectable in many biological samples at all examined sites, especially in Montenegro, indicating widespread ground-surface DU contamination, albeit at very low level. The uranium isotopic concentrations in air obtained from the air filter samples collected in Serbia and Montenegro were found to be in the range of 1.99-42.1 microBqm(-3) for (238)U, 0.96-38.0 microBqm(-3) for (234)U, and 0.05-1.83 microBqm(-3) for (235)U, being in the typical range of natural uranium values. Thus said, most of the air samples are DU positive, this fact agreeing well with the widespread DU contamination detected in the biological samples. The uranium concentrations in water samples collected in Serbia and Montenegro were found to be in the range of 0.40-21.9 mBql(-1) for (238)U, 0.27-28.1 mBql(-1) for (234)U, and 0.01-0.88 mBql(-1) for (235)U, these values being much lower than those in mineral water found in central Italy and below the WHO guideline for drinking water. From a radiotoxicological point of view, at this moment there is no significant radiological risk related to these investigated

  3. [Biologic effects of different concentrations of putrescine on human umbilical vein endothelial cells].

    Science.gov (United States)

    Chen, Jianxia; Rong, Xinzhou; Fan, Guicheng; Li, Songze; Zhang, Tao; Li, Qinghui

    2015-12-01

    To explore the effects of different concentrations of putrescine on proliferation, migration, and apoptosis of human umbilical vein endothelial cells (HUVECs). HUVECs were routinely cultured in vitro. The 3rd to the 5th passage of HUVECs were used in the following experiments. (1) Cells were divided into 500, 1 000, and 5 000 µg/mL putrescine groups according to the random number table (the same grouping method was used for following grouping), with 3 wells in each group, which were respectively cultured with complete culture solution containing putrescine in the corresponding concentration for 24 h. Morphology of cells was observed by inverted optical microscope. (2) Cells were divided into 0.5, 1.0, 5.0, 10.0, 50.0, 100.0, 500.0, 1 000.0 µg/mL putrescine groups, and control group, with 4 wells in each group. Cells in the putrescine groups were respectively cultured with complete culture solution containing putrescine in the corresponding concentration for 24 h, and cells in control group were cultured with complete culture solution with no additional putrescine for 24 h. Cell proliferation activity (denoted as absorption value) was measured by colorimetry. (3) Cells were divided (with one well in each group) and cultured as in experiment (2), and the migration ability was detected by transwell migration assay. (4) Cells were divided (with one flask in each group) and cultured as in experiment (2), and the cell apoptosis rate was determined by flow cytometer. Data were processed with one-way analysis of variance, Kruskal-Wallis test, and Dunnett test. (1) After 24-h culture, cell attachment was good in 500 µg/mL putrescine group, and no obvious change in the shape was observed; cell attachment was less in 1 000 µg/mL putrescine group and the cells were small and rounded; cells in 5 000 µg/mL putrescine group were in fragmentation without attachment. (2) The absorption values of cells in 0.5, 1.0, 5.0, 10.0, 50.0, 100.0, 500.0, 1 000.0 µg/mL putrescine groups

  4. A study of the effect of helium concentration and displacement damage on the microstructure of helium ion irradiated tungsten

    Science.gov (United States)

    Harrison, R. W.; Greaves, G.; Hinks, J. A.; Donnelly, S. E.

    2017-11-01

    Transmission electron microscopy (TEM) with in-situ He ion irradiation has been used to examine the damage microstructure of W when varying the helium concentration to displacement damage ratio, irradiation temperature and total dose. Irradiations employed 15, 60 or 85 keV He ions, at temperatures between 500 and 1000 °C up to doses of ∼3.0 DPA. Once nucleated and grown to an observable size in the TEM, bubble diameter as a function of irradiation dose did not measurably increase at irradiation temperatures of 500 °C between 1.0 and 3.0 DPA; this is attributed to the low mobility of vacancies and He/vacancy complexes at these temperatures. Bubble diameter increased slightly for irradiation temperatures of 750 °C and rapidly increased when irradiated at 1000 °C. Dislocation loops were observed at irradiation temperatures of 500 and 750 °C and no loops were observed at 1000 °C. Burgers vectors of the dislocations were determined to be b = ±½ type only and both vacancy and interstitial loops were observed. The proportion of interstitial loops increased with He-appm/DPA ratio and this is attributed to the concomitant increase in bubble areal density, which reduces the vacancy flux for both the growth of vacancy-type loops and the annihilation of interstitial clusters.

  5. Online Measurement of Exhaled NO Concentration and Its Production Sites by Fast Non-equilibrium Dilution Ion Mobility Spectrometry

    Science.gov (United States)

    Peng, Liying; Jiang, Dandan; Wang, Zhenxin; Liu, Jiwei; Li, Haiyang

    2016-03-01

    Exhaled nitric oxide (NO) is one of the most promising breath markers for respiratory diseases. Its profile for exhalation and the respiratory NO production sites can provide useful information for medical disease diagnosis and therapeutic procedures. However, the high-level moisture in exhaled gas always leads to the poor selectivity and sensitivity for ion spectrometric techniques. Herein, a method based on fast non-equilibrium dilution ion mobility spectrometry (NED-IMS) was firstly proposed to directly monitor the exhaled NO profile on line. The moisture interference was eliminated by turbulently diluting the original moisture to 21% of the original with the drift gas and dilution gas. Weak enhancement was observed for humid NO response and its limit of detection at 100% relative humidity was down to 0.58 ppb. The NO concentrations at multiple exhalation flow rates were measured, while its respiratory production sites were determined by using two-compartment model (2CM) and Högman and Meriläinen algorithm (HMA). Last but not the least, the NO production sites were analyzed hourly to tentatively investigate the daily physiological process of NO. The results demonstrated the capacity of NED-IMS in the real-time analysis of exhaled NO and its production sites for clinical diagnosis and assessment.

  6. Fast Biological Modeling for Voxel-based Heavy Ion Treatment Planning Using the Mechanistic Repair-Misrepair-Fixation Model and Nuclear Fragment Spectra

    Energy Technology Data Exchange (ETDEWEB)

    Kamp, Florian [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); Department of Radiation Oncology, Technische Universität München, Klinikum Rechts der Isar, München (Germany); Physik-Department, Technische Universität München, Garching (Germany); Cabal, Gonzalo [Experimental Physics–Medical Physics, Ludwig Maximilians University Munich, Garching (Germany); Mairani, Andrea [Medical Physics Unit, Centro Nazionale Adroterapia Oncologica (CNAO), Pavia (Italy); Heidelberg Ion-Beam Therapy Center, Heidelberg (Germany); Parodi, Katia [Experimental Physics–Medical Physics, Ludwig Maximilians University Munich, Garching (Germany); Wilkens, Jan J. [Department of Radiation Oncology, Technische Universität München, Klinikum Rechts der Isar, München (Germany); Physik-Department, Technische Universität München, Garching (Germany); Carlson, David J., E-mail: david.j.carlson@yale.edu [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States)

    2015-11-01

    Purpose: The physical and biological differences between heavy ions and photons have not been fully exploited and could improve treatment outcomes. In carbon ion therapy, treatment planning must account for physical properties, such as the absorbed dose and nuclear fragmentation, and for differences in the relative biological effectiveness (RBE) of ions compared with photons. We combined the mechanistic repair-misrepair-fixation (RMF) model with Monte Carlo-generated fragmentation spectra for biological optimization of carbon ion treatment plans. Methods and Materials: Relative changes in double-strand break yields and radiosensitivity parameters with particle type and energy were determined using the independently benchmarked Monte Carlo damage simulation and the RMF model to estimate the RBE values for primary carbon ions and secondary fragments. Depth-dependent energy spectra were generated with the Monte Carlo code FLUKA for clinically relevant initial carbon ion energies. The predicted trends in RBE were compared with the published experimental data. Biological optimization for carbon ions was implemented in a 3-dimensional research treatment planning tool. Results: We compared the RBE and RBE-weighted dose (RWD) distributions of different carbon ion treatment scenarios with and without nuclear fragments. The inclusion of fragments in the simulations led to smaller RBE predictions. A validation of RMF against measured cell survival data reported in published studies showed reasonable agreement. We calculated and optimized the RWD distributions on patient data and compared the RMF predictions with those from other biological models. The RBE values in an astrocytoma tumor ranged from 2.2 to 4.9 (mean 2.8) for a RWD of 3 Gy(RBE) assuming (α/β){sub X} = 2 Gy. Conclusions: These studies provide new information to quantify and assess uncertainties in the clinically relevant RBE values for carbon ion therapy based on biophysical mechanisms. We present results from

  7. A biological indicator of inorganic arsenic exposure using the sum of urinary inorganic arsenic and monomethylarsonic acid concentrations

    Science.gov (United States)

    Hata, Akihisa; Kurosawa, Hidetoshi; Endo, Yoko; Yamanaka, Kenzo; Fujitani, Noboru; Endo, Ginji

    2016-01-01

    Objectives: The sum of urinary inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) concentrations is used for the biological monitoring of occupational iAs exposure. Although DMA is a major metabolite of iAs, it is an inadequate index because high DMA levels are present in urine after seafood consumption. We estimated the urinary iAs+MMA concentration corresponding to iAs exposure. Methods: We used data from two arsenic speciation analyses of urine samples from 330 Bangladeshi with oral iAs exposure and 172 Japanese workers without occupational iAs exposure using high-performance liquid chromatography with inductively coupled plasma mass spectrometry. Results: iAs, MMA, and DMA, but not arsenobetaine (AsBe), were detected in the urine of the Bangladeshi subjects. The correlation between iAs+MMA+DMA and iAs+MMA was obtained as log (iAs+MMA) = 1.038 log (iAs+MMA+DMA) -0.658. Using the regression formula, the iAs+MMA value was calculated as 2.15 and 7.5 μg As/l, corresponding to 3 and 10 μg As/m3 of exposures, respectively. In the urine of the Japanese workers, arsenic was mostly excreted as AsBe. We used the 95th percentile of iAs+MMA (12.6 μg As/l) as the background value. The sum of the calculated and background values can be used as a biological indicator of iAs exposure. Conclusion: We propose 14.8 and 20.1 μg As/l of urinary iAs+MMA as the biological indicators of 3 and 10 μg As/m3 iAs exposure, respectively. PMID:27010090

  8. Water-soluble metal-binding polymers with ultrafiltration: A technology for the removal, concentration, and recovery of metal ions from aqueous streams

    International Nuclear Information System (INIS)

    Smith, B.F.; Robison, T.W.; Jarvinen, G.D.

    1997-01-01

    The use of water-soluble metal-binding polymers coupled with ultrafiltration (UF) is a technology under development to selectively concentrate and recover valuable or regulated metal-ions from dilute process or waste waters. The polymers have a sufficiently large molecular size that they can be separated and concentrated using commercially available UF technology. The polymers can then be reused by changing the solution conditions to release the metal-ions, which are recovered in a concentrated form for recycle or disposal. Pilot-scale demonstrations have been completed for a variety of waste streams containing low concentrations of metal ions including electroplating wastes (zinc and nickel) and nuclear waste streams (plutonium and americium). Many other potential commercial applications exist including remediation of contaminated solids. An overview of both the pilot-scale demonstrated applications and small scale testing of this technology are presented

  9. Water-soluble metal-binding polymers with ultrafiltration: A technology for the removal, concentration, and recovery of metal ions from aqueous streams

    Energy Technology Data Exchange (ETDEWEB)

    Smith, B.F.; Robison, T.W.; Jarvinen, G.D.

    1997-12-31

    The use of water-soluble metal-binding polymers coupled with ultrafiltration (UF) is a technology under development to selectively concentrate and recover valuable or regulated metal-ions from dilute process or waste waters. The polymers have a sufficiently large molecular size that they can be separated and concentrated using commercially available UF technology. The polymers can then be reused by changing the solution conditions to release the metal-ions, which are recovered in a concentrated form for recycle or disposal. Pilot-scale demonstrations have been completed for a variety of waste streams containing low concentrations of metal ions including electroplating wastes (zinc and nickel) and nuclear waste streams (plutonium and americium). Many other potential commercial applications exist including remediation of contaminated solids. An overview of both the pilot-scale demonstrated applications and small scale testing of this technology are presented.

  10. Application of Ion Mobility Spectrometry (IMS) in forensic chemistry and toxicology with focus on biological matrices

    Science.gov (United States)

    Bernhard, Werner; Keller, Thomas; Regenscheit, Priska

    1995-01-01

    The IMS (Ion Mobility Spectroscopy) instrument 'Ionscan' takes advantage of the fact that trace quantities of illicit drugs are adsorbed on dust particles on clothes, in cars and on other items of evidence. The dust particles are collected on a membrane filter by a special attachment on a vacuum cleaner. The sample is then directly inserted into the spectrometer and can be analyzed immediately. We show casework applications of a forensic chemistry and toxicology laboratory. One new application of IMS in forensic chemistry is the detection of psilocybin in dried mushrooms without any further sample preparation.

  11. Biological effect of 20 keV N+ ion implantation on Stevia rebaudianum

    International Nuclear Information System (INIS)

    Su Tingting; Yang Tingting; Ji Guohong; Xiang Xingjia; Chen Xuetao; Wang Yu; Wu Yaojin

    2010-01-01

    The germinability and gemination rate of Stevia rebaudianum seeds implanted with 20 keV N + ions in doses of 0 (CK), 100 x 2500, 400 x 2500 and 1000 x 2500 N + /cm 2 were studied by analyzing the differences in seed germinability and gemination rate between the groups. By statistical analysis, the germinability and gemination rate were affected at the level of α=0.05 by the implantation dose. The results showed that the germinability and gemination rate increased with the dose first and then decreased. At 400 x 2500 N + /cm 2 , the seeds had the largest germinability and the gemination rate. (authors)

  12. Application of ion mobility spectrometry for the determination of tramadol in biological samples

    OpenAIRE

    Ali Sheibani; Najmeh Haghpazir

    2014-01-01

    In this study, a simple and rapid ion mobility spectrometry (IMS) method has been described for the determination of tramadol. The operating instrumental parameters that could influence IMS were investigated and optimized (temperature; injection: 220 and IMS cell: 190°C, flow rate; carrier: 300 and drift: 600 mL/minute, voltage; corona: 2300 and drift: 7000 V, pulse width: 100 μs). Under optimum conditions, the calibration curves were linear within two orders of magnitude with R2 ≥ 0.998 for ...

  13. Biological nitrogen and carbon removal in a gravity flow biomass concentrator reactor for municipal sewage treatment.

    Science.gov (United States)

    Scott, Daniel; Hidaka, Taira; Campo, Pablo; Kleiner, Eric; Suidan, Makram T; Venosa, Albert D

    2013-01-01

    A novel membrane system, the Biomass Concentrator Reactor (BCR), was evaluated as an alternative technology for the treatment of municipal wastewater. Because the BCR is equipped with a membrane whose average poresize is 20 μm (18-28 μm), the reactor requires low-pressure differential to operate (gravity). The effectiveness of this system was evaluated for the removal of carbon and nitrogen using two identical BCRs, identified as conventional and hybrid, that were operated in parallel. The conventional reactor was operated under full aerobic conditions (i.e., organic carbon and ammonia oxidation), while the hybrid reactor incorporated an anoxic zone for nitrate reduction as well as an aerobic zone for organic carbon and ammonia oxidation. Both reactors were fed synthetic wastewater at a flow rate of 71 L d(-1), which resulted in a hydraulic retention time of 9 h. In the case of the hybrid reactor, the recycle flow from the aerobic zone to the anoxic zone was twice the feed flow rate. Reactor performance was evaluated under two solids retention times (6 and 15 d). Under these conditions, the BCRs achieved nearly 100% mixed liquor solids separation with a hydraulic head differential of less than 2.5 cm. The COD removal efficiency was over 90%. Essentially complete nitrification was achieved in both systems, and nitrogen removal in the hybrid reactor was close to the expected value (67%). Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Spectral and spatial shaping of a laser-produced ion beam for radiation-biology experiments

    Directory of Open Access Journals (Sweden)

    L. Pommarel

    2017-03-01

    Full Text Available The study of radiation biology on laser-based accelerators is most interesting due to the unique irradiation conditions they can produce, in terms of peak current and duration of the irradiation. In this paper we present the implementation of a beam transport system to transport and shape the proton beam generated by laser-target interaction for in vitro irradiation of biological samples. A set of four permanent magnet quadrupoles is used to transport and focus the beam, efficiently shaping the spectrum and providing a large and relatively uniform irradiation surface. Real time, absolutely calibrated, dosimetry is installed on the beam line, to enable shot-to-shot control of dose deposition in the irradiated volume. Preliminary results of cell sample irradiation are presented to validate the robustness of the full system.

  15. Blood concentrations of ions and metals in amateur and elite runners using neutron activation analyses

    International Nuclear Information System (INIS)

    Santos, Luciana Kovacs dos

    2012-01-01

    In this study Br, Ca, Cl, Fe, I, K, Mg, Na, S and Zn concentration were investigated in blood of Brazilian athletes (endurance) using Neutron Activation Analyses technique (NAA). The blood samples were collected from male amateur athletes (AR) and male and female elite athletes (ER), ranging from 18 to 36 year old. The blood samples were collected at the LABEX/UNICAMP and they were irradiated in the nuclear reactor IEA-R1 at IPEN (Sao Paulo, Brazil). The range (at rest) established for AR and ER were compared with the control group (CG), subjects of same gender and age but not involved with physical activities, and showed significant differences for Ca (51 - 439 mgL -1 for CG, 162 - 410 mgL -1 for AR and 64 - 152 mgL -1 for ER) and Br (7.4 - 30.6 mgL -1 for CG, 4.0 - 9.6 mgL -1 for AR and 1.9 - 3.5 mgL -1 for ER), suggesting that a strong dependency of these limits in function of adopted physical training exists. We also performed a systematic investigation for the AR before, during and after the exercise program. These data can be considered for the preparation of a balanced diet, for evaluating the performance of the athletes during the period of competition preparation as well as contributing for proposing new protocols of clinical evaluation not reported in the literature yet. (author)

  16. Integral equation models for the inverse problem of biological ion channel distributions

    International Nuclear Information System (INIS)

    French, D A; Groetsch, C W

    2007-01-01

    Olfactory cilia are thin hair-like filaments that extend from olfactory receptor neurons into the nasal mucus. Transduction of an odor into an electrical signal is accomplished by a depolarizing influx of ions through cyclic-nucleotide-gated channels in the membrane that forms the lateral surface of the cilium. In an experimental procedure developed by S. Kleene, a cilium is detached at its base and drawn into a recording pipette. The cilium base is then immersed in a bath of a channel activating agent (cAMP) which is allowed to diffuse into the cilium interior, opening channels as it goes and initiating a transmembrane current. The total current is recorded as a function of time and serves as data for a nonlinear integral equation of the first kind modeling the spatial distribution of ion channels along the length of the cilium. We discuss some linear Fredholm integral equations that result from simplifications of this model. A numerical procedure is proposed for a class of integral equations suggested by this simplified model and numerical results using simulated and laboratory data are presented

  17. Alcohol intoxication at Swedish football matches: A study using biological sampling to assess blood alcohol concentration levels among spectators.

    Directory of Open Access Journals (Sweden)

    Natalie Durbeej

    Full Text Available Alcohol use and alcohol-related problems, including accidents, vandalism and violence, at sporting events are of increased concern in Sweden and other countries. The relationship between alcohol use and violence has been established and can be explained by the level of intoxication. Given the occurrence of alcohol use and alcohol-related problems at sporting events, research has assessed intoxication levels measured through biological sampling among spectators. This cross-sectional study aimed to assess the level of alcohol intoxication among spectators at football matches in the Swedish Premier Football League. Spectators were randomly selected and invited to participate in the study. Alcohol intoxication was measured with a breath analyser for Blood Alcohol Concentration levels, and data on gender, age, and recent alcohol use were gathered through a face-to-face interview. Blood Alcohol Concentration samples from 4420 spectators were collected. Almost half (46.8% had a positive Blood Alcohol Concentration level, with a mean value of 0.063%, while 8.9% had a Blood Alcohol Concentration level ≥ 0.1%, with a mean value of 0.135%. Factors that predicted a higher Blood Alcohol Concentration level included male gender (p = 0.005, lower age (p < 0.001, attending a local derby (p < 0.001, alcohol use prior to having entered the arena (p < 0.001, attending a weekend match (p < 0.001, and being a spectator at supporter sections (p < 0.001. About half of all spectators at football matches in the Swedish Premier Football League drink alcohol in conjunction with the match. Approximately one tenth have a high level of alcohol intoxication.

  18. Biological and life-history factors affecting total mercury concentrations in Arctic charr from Heintzelman Lake, Ellesmere Island, Nunavut

    International Nuclear Information System (INIS)

    Velden, Shannon van der; Reist, James D.; Babaluk, John A.; Power, Michael

    2012-01-01

    A snapshot sample of Arctic charr (Salvelinus alpinus) from Heintzelman Lake (81°42′N, 66°56′W), Ellesmere Island, Canada was used to elucidate the biological and life-history factors potentially influencing individual total mercury (THg) concentrations. Migratory history was significant, with anadromous fish having a lower mean THg concentration (64 μg/kg ww) than the non-anadromous Arctic charr (117 μg/kg ww). The increase in individual THg concentration with age was shown to be independent of length-at-age when large and small individuals within the same age groups were compared. Similarly, the diets of individual Arctic charr were comparable regardless of size, and there was no apparent ontogenetic shift in diet that could explain differences in length-at-age or THg concentration among fast- and slow-growing groups of fish (i.e., fish of the same age but differing sizes). Maturity state was also not related to THg concentration, but appears to be related to differences in length-at-age, with slow-growing fish allocating more energy to reproduction than fast-growing conspecifics. The differences in THg concentration among individual Arctic charr were best explained by fish age. We suggest that the increase in mercury concentration with age can be altered by a shift in diet (e.g., to piscivory) or habitat (e.g., anadromy), but is otherwise unaffected by changes in size or length-at-age. -- Highlights: ► Total mercury concentrations ([THg]) were measured in Arctic charr from a single lake in the Canadian high Arctic. ► Anadromous Arctic charr had a significantly lower mean [THg] (64 μg/kg ww) than the non-anadromous fish (117 μg/kg ww). ► Length-at-age (i.e., average somatic growth rate) was not related to mean [THg] when same-age groups were compared. ► Prey resource use, determined by δ 13 C and δ 15 N isotopes and gut contents, was similar among fast- and slow-growing fish. ► Maturity state was not related to [THg], but the slow

  19. Recent progress of task-specific ionic liquids in chiral resolution and extraction of biological samples and metal ions.

    Science.gov (United States)

    Wu, Datong; Cai, Pengfei; Zhao, Xiaoyong; Kong, Yong; Pan, Yuanjiang

    2018-01-01

    Ionic liquids have been functionalized for modern applications. The functional ionic liquids are also called task-specific ionic liquids. Various task-specific ionic liquids with certain groups have been constructed and exploited widely in the field of separation. To take advantage of their properties in separation science, task-specific ionic liquids are generally used in techniques such as liquid-liquid extraction, solid-phase extraction, gas chromatography, high-performance liquid chromatography, and capillary electrophoresis. This review mainly covers original research papers published in the last five years, and we will focus on task-specific ionic liquids as the chiral selectors in chiral resolution and as extractant or sensor for biological samples and metal ion purification. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Enhancement of biological mass spectrometry by using separations based on changes in ion mobility (FAIMS and DMS).

    Science.gov (United States)

    Purves, Randy W

    2013-01-01

    Analysis of complex biological samples for low-level analytes by liquid chromatography-tandem mass spectrometry (LC-MS/MS) often requires additional selectivity. Differential mobility techniques (FAIMS and DMS) have been shown to enhance LC-MS/MS analyses by separating ions in the gas-phase on a millisecond timescale by use of a mechanism that is complementary to both liquid chromatography and mass spectrometry. In this overview, a simplified description of the operation of these devices is given and an example presented that illustrates the utility of FAIMS (DMS) for solving a challenging analytical assay. Important recent advances in the field, including work with gas modifiers, are presented, along with an outlook for the technology.

  1. Tertiary treatment of textile wastewater with combined media biological aerated filter (CMBAF) at different hydraulic loadings and dissolved oxygen concentrations

    International Nuclear Information System (INIS)

    Liu Fang; Zhao Chaocheng; Zhao Dongfeng; Liu Guohua

    2008-01-01

    An up-flow biological aerated filter packed with two layers media was employed for tertiary treatment of textile wastewater secondary effluent. Under steady state conditions, good performance of the reactor was achieved and the average COD, NH 4 + -N and total nitrogen (TN) in the effluent were 31, 2 and 8 mg/L, respectively. For a fixed dissolved oxygen (DO) concentration, an increase of hydraulic loading resulted in a decrease in substrate removal. With the increase of hydraulic loadings from 0.13 to 0.78 m 3 /(m 2 h), the removal efficiencies of COD, NH 4 + -N and TN all decreased, which dropped from 52 to 38%, from 90 to 68% and from 45 to 33%, respectively. In addition, the results also confirmed that the increase of COD and NH 4 + -N removal efficiencies resulted from the increase of DO concentrations, but this variation trend was not observed for TN removal. With the increase of DO concentrations from 2.4 to 6.1 mg/L, the removal efficiencies of COD and NH 4 + -N were 39-53% and 64-88%, whenas TN removal efficiencies increased from 39 to 42% and then dropped to 35%

  2. The separation of [32P]inositol phosphates by ion-pair chromatography: Optimization of the method and biological applications

    International Nuclear Information System (INIS)

    Sulpice, J.C.; Gascard, P.; Journet, E.; Rendu, F.; Renard, D.; Poggioli, J.; Giraud, F.

    1989-01-01

    We have developed an ion-pair reverse-phase HPLC method to measure inositol phosphates in 32 P-labeled cells. The different chromatographic parameters were analyzed to optimize the resolution of the 32 P-labeled metabolites. Analysis of inositol phosphates in biological samples was improved by a single charcoal pretreatment which eliminated interfering nucleotides without removing inositol phosphates. The kinetics of production of inositol phosphates in calcium-activated erythrocytes, vasopressin-stimulated hepatocytes, and thrombin-activated platelets were analyzed. Original data on the activation of phosphoinositide phospholipase C were obtained in intact erythrocytes by direct measurement of inositol (1,4,5)P3. Data from agonist-stimulated hepatocytes and platelets were consistent with those from previous studies. In conclusion, this technique offers many advantages over the methodologies currently employed involving anion-exchange chromatography and [ 3 H]inositol labeling: (i) 32 P labeling is less expensive and more efficient than 3 H labeling and can be used with all types of cells without permeabilization treatments and (ii) ion-pair HPLC gives good resolution of inositol phosphates from nucleotides with shorter retention times, and long reequilibration periods are not required

  3. On the concept of resting potential--pumping ratio of the Na⁺/K⁺ pump and concentration ratios of potassium ions outside and inside the cell to sodium ions inside and outside the cell.

    Science.gov (United States)

    Xu, Ning

    2013-01-01

    In animal cells, the resting potential is established by the concentration gradients of sodium and potassium ions and the different permeabilities of the cell membrane to them. The large concentration gradients of sodium and potassium ions are maintained by the Na⁺/K⁺ pump. Under physiological conditions, the pump transports three sodium ions out of and two potassium ions into the cell per ATP hydrolyzed. However, unlike other primary or secondary active transporters, the Na⁺/K⁺ pump does not work at the equilibrium state, so the pumping ratio is not a thermodynamic property of the pump. In this article, I propose a dipole-charging model of the Na⁺/K⁺ pump to prove that the three Na⁺ to two K⁺ pumping ratio of the Na⁺/K⁺ pump is determined by the ratio of the ionic mobilities of potassium to sodium ions, which is to ensure the time constant τ and the τ-dependent processes, such as the normal working state of the Na⁺/K⁺ pump and the propagation of an action potential. Further, the concentration ratios of potassium ions outside and inside the cell to sodium ions inside and outside the cell are 0.3027 and 0.9788, respectively, and the sum of the potassium and sodium equilibrium potentials is -30.3 mV. A comparative study on these constants is made for some marine, freshwater and terrestrial animals. These findings suggest that the pumping ratio of the Na⁺/K⁺ pump and the ion concentration ratios play a role in the evolution of animal cells.

  4. Last Glacial to Holocene changes of deep and intermediate water carbonate ion concentrations in the Southern Ocean: constraints from foraminiferal Boron/Calcium ratios

    OpenAIRE

    Kersten, Franziska

    2013-01-01

    In this thesis, the first records of intermediate and deep water carbonate ion concentrations in the South Pacific were generated in order to study carbon cycle dynamics throughout the past 30,000 years. Benthic foraminiferal B/Ca, an indicator of past seawater carbonate ion saturation is the main paleoceanographic proxy that was used in this study. Down-core proxy studies carried out within the scope of this thesis were used to address currently unresolved questions about the origin, mechani...

  5. High-Thermal- and Air-Stability Cathode Material with Concentration-Gradient Buffer for Li-Ion Batteries.

    Science.gov (United States)

    Shi, Ji-Lei; Qi, Ran; Zhang, Xu-Dong; Wang, Peng-Fei; Fu, Wei-Gui; Yin, Ya-Xia; Xu, Jian; Wan, Li-Jun; Guo, Yu-Guo

    2017-12-13

    Delivery of high capacity with high thermal and air stability is a great challenge in the development of Ni-rich layered cathodes for commercialized Li-ion batteries (LIBs). Herein we present a surface concentration-gradient spherical particle with varying elemental composition from the outer end LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM) to the inner end LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA). This cathode material with the merit of NCM concentration-gradient protective buffer and the inner NCA core shows high capacity retention of 99.8% after 200 cycles at 0.5 C. Furthermore, this cathode material exhibits much improved thermal and air stability compared with bare NCA. These results provide new insights into the structural design of high-performance cathodes with high energy density, long life span, and storage stability materials for LIBs in the future.

  6. Zero-Gap Alkaline Water Electrolysis Using Ion-Solvating Polymer Electrolyte Membranes at Reduced KOH Concentrations

    DEFF Research Database (Denmark)

    Kraglund, Mikkel Rykær; Aili, David; Jankova Atanasova, Katja

    2016-01-01

    Membranes based on poly(2,2'-(m-phenylene)-5,5-bibenzimidazole) (m-PBI) can dissolve large amounts of aqueous KOH to give electrolyte systems with ion conductivity in a practically useful range. The conductivity of the membrane strongly depends on the concentration of the aqueous KOH phase......, reaching about 10-1 S cm-1 or higher in 15-25 wt% KOH. Herein, m-PBI membranes are systematically characterized with respect to performance and short-term stability as electrolyte in a zero-gap alkaline water electrolyzer at different KOH concentrations. Using plain uncatalyzed nickel foam electrodes......, the cell based on m-PBI outperforms the cell based on the commercially available state-of-the-art diaphragm and reaches a current density of 1500 mA cm-2 at 2.4 V in 20 wt% KOH at 80°C. The cell performance remained stable during two days of operation, though post analysis of the membrane using size...

  7. Effect of Carbon Concentration on the Sputtering of Carbon-Rich SiC Bombarded by Helium Ions

    Directory of Open Access Journals (Sweden)

    Xinghao Liang

    2018-02-01

    Full Text Available Silicon carbide (SiC is considered as an important material for nuclear engineering due to its excellent properties. Changing the carbon content in SiC can regulate and control its elastic and thermodynamic properties, but a simulation study of the effect of carbon content on the sputtering (caused by the helium ions of SiC is still lacking. In this work, we used the Monte-Carlo and molecular dynamics simulation methods to study the effects of carbon concentration, incidence energy, incident angle, and target temperature on the sputtering yield of SiC. The results show that the incident ions’ energy and angle have a significant effect on sputtering yield of SiC when the carbon concentration in SiC is around 62 at %, while the target temperature has a little effect on the sputtering yield of SiC. Our work might provide theoretical support for the experimental research and engineering application of carbon fiber-reinforced SiC that be used as the plasma-facing material in tokamak fusion reactors.

  8. Energy deposition and the formation of biologically significant lesions by accelerated ions

    International Nuclear Information System (INIS)

    Kiefer, J.

    1985-01-01

    The assumption that the number of biologically significant lesions depends only on the amount of of energy absorbed in a critical cellular site is not able to explain the increase of RBE with LET and leads to large discrepancies between predicted and measured inactivation cross sections in the LET range between 20 and 200 keV.μm -1 . It has, therefore, to be concluded that not only the amount of energy absorbed but also the spatial pattern of this deposition plays a decisive role. In the model presented it is postulated that two or more energy deposition events in nanometre sites are required for the formation of biologically significant lesions. This cooperative action has to take place in very short times so that only interactions within a single particle track contribute. The mathematical treatment will be outlined and qualitatively shown that the model is able to predict RBE-LET relationships. The calculations use a track structure model based on classical collision mechanics. It is compared with existing experimental results showing good agreement at least for higher particle energies. (author)

  9. Evaluation of the relative biological effectiveness of carbon ion beams in the cerebellum using the rat organotypic slice culture system

    International Nuclear Information System (INIS)

    Yoshida, Yukari; Katoh, Hiroyuki; Nakano, Takashi; Suzuki, Yoshiyuki; Al-Jahdari, Wael S.; Shirai, Katsuyuki; Hamada, Nobuyuki; Funayama, Tomoo; Sakashita, Tetsuya; Kobayashi, Yasuhiko

    2012-01-01

    The purpose of this study was to clarify the relative biological effectiveness (RBE) values of carbon ion (C) beams in normal brain tissues, a rat organotypic slice culture system was used. The cerebellum was dissected from 10-day-old Wistar rats, cut parasagittally into approximately 600-μm-thick slices and cultivated using a membrane-based culture system with a liquid-air interface. Slices were irradiated with 140 kV X-rays and 18.3 MeV/amu C-beams (linear energy transfer=108 keV/μm). After irradiation, the slices were evaluated histopathologically using hematoxylin and eosin staining, and apoptosis was quantified using the TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay. Disorganization of the external granule cell layer (EGL) and apoptosis of the external granule cells (EGCs) were induced within 24 h after exposure to doses of more than 5 Gy from C-beams and X-rays. In the early postnatal cerebellum, morphological changes following exposure to C-beams were similar to those following exposure to X-rays. The RBEs values of C-beams using the EGL disorganization and the EGC TUNEL index endpoints ranged from 1.4 to 1.5. This system represents a useful model for assaying the biological effects of radiation on the brain, especially physiological and time-dependent phenomena. (author)

  10. Quantitative Visualization of Salt Concentration Distributions in Lithium-Ion Battery Electrolytes during Battery Operation Using X-ray Phase Imaging.

    Science.gov (United States)

    Takamatsu, Daiko; Yoneyama, Akio; Asari, Yusuke; Hirano, Tatsumi

    2018-02-07

    A fundamental understanding of concentrations of salts in lithium-ion battery electrolytes during battery operation is important for optimal operation and design of lithium-ion batteries. However, there are few techniques that can be used to quantitatively characterize salt concentration distributions in the electrolytes during battery operation. In this paper, we demonstrate that in operando X-ray phase imaging can quantitatively visualize the salt concentration distributions that arise in electrolytes during battery operation. From quantitative evaluation of the concentration distributions at steady states, we obtained the salt diffusivities in electrolytes with different initial salt concentrations. Because of no restriction on samples and high temporal and spatial resolutions, X-ray phase imaging will be a versatile technique for evaluating electrolytes, both aqueous and nonaqueous, of many electrochemical systems.

  11. N,N'-Dimethylthiourea dioxide formation from N,N'-dimethylthiourea reflects hydrogen peroxide concentrations in simple biological systems

    International Nuclear Information System (INIS)

    Curtis, W.E.; Muldrow, M.E.; Parker, N.B.; Barkley, R.; Linas, S.L.; Repine, J.E.

    1988-01-01

    The authors hypothesized that measurement of a specific product from reaction of N,N'-dimethylthiourea (Me 2 TU) and H 2 O 2 would provide a good indication of the H 2 O 2 scavenging and protection seen after addition of Me 2 TU to biological systems. They found that addition of H 2 O 2 to Me 2 TU yielded a single stable product, Me 2 TU dioxide. Me 2 TU dioxide formation correlated with Me 2 TU consumption as a function of added H 2 O 2 concentration and was prevented by simultaneous addition of catalase (but not boiled catalase), superoxide dismutase, dimethyl sulfoxide, mannitol, or sodium benzoate. Me 2 TU dioxide formation, Me 2 TU consumption, and H 2 O 2 concentration increases occurred in mixtures containing phorbol 12-myristate 13-acetate (PMA) and normal human neutrophils but not in mixtures containing PMA and neutrophils from patients with chronic granulomatous disease or in mixtures containing PMA and normal neutrophils and catalase. Me 2 TU dioxide formation also occurred in isolated rat lungs perfused with Me 2 TU and H 2 O 2 but not in lungs perfused with Me 2 TU and elastase, histamine, or oleic acid. In contrast, Me 2 TU dioxide formation did not occur after exposure of Me 2 TU to 60 Co-generated hydroxyl radical or hypochlorous acid in the presence of catalase. The results indicate that reaction of Me 2 TU with H 2 O 2 selectively forms Me 2 TU may be useful for assessing the presence and significance of H 2 O 2 in biological systems

  12. Metal Ion Concentrations in Body Fluids after Implantation of Hip Replacements with Metal-on-Metal Bearing – Systematic Review of Clinical and Epidemiological Studies

    Science.gov (United States)

    Hartmann, Albrecht; Hannemann, Franziska; Lützner, Jörg; Seidler, Andreas; Drexler, Hans; Günther, Klaus-Peter; Schmitt, Jochen

    2013-01-01

    Introduction The use of metal-on-metal (MoM) total hip arthroplasty (THA) increased in the last decades. A release of metal products (i.e. particles, ions, metallo-organic compounds) in these implants may cause local and/or systemic adverse reactions. Metal ion concentrations in body fluids are surrogate measures of metal exposure. Objective To systematically summarize and critically appraise published studies concerning metal ion concentrations after MoM THA. Methods Systematic review of clinical trials (RCTs) and epidemiological studies with assessment of metal ion levels (cobalt, chromium, titanium, nickel, molybdenum) in body fluids after implantation of metalliferous hip replacements. Systematic search in PubMed and Embase in January 2012 supplemented by hand search. Standardized abstraction of pre- and postoperative metal ion concentrations stratified by type of bearing (primary explanatory factor), patient characteristics as well as study quality characteristics (secondary explanatory factors). Results Overall, 104 studies (11 RCTs, 93 epidemiological studies) totaling 9.957 patients with measurement of metal ions in body fluids were identified and analyzed. Consistently, median metal ion concentrations were persistently elevated after implantation of MoM-bearings in all investigated mediums (whole blood, serum, plasma, erythrocytes, urine) irrespective of patient characteristics and study characteristics. In several studies very high serum cobalt concentrations above 50 µg/L were measured (detection limit typically 0.3 µg/L). Highest metal ion concentrations were observed after treatment with stemmed large-head MoM-implants and hip resurfacing arthroplasty. Discussion Due to the risk of local and systemic accumulation of metallic products after treatment with MoM-bearing, risk and benefits should be carefully balanced preoperatively. The authors support a proposed „time out“ for stemmed large-head MoM-THA and recommend a restricted indication for hip

  13. Metal ion concentrations in body fluids after implantation of hip replacements with metal-on-metal bearing--systematic review of clinical and epidemiological studies.

    Directory of Open Access Journals (Sweden)

    Albrecht Hartmann

    Full Text Available INTRODUCTION: The use of metal-on-metal (MoM total hip arthroplasty (THA increased in the last decades. A release of metal products (i.e. particles, ions, metallo-organic compounds in these implants may cause local and/or systemic adverse reactions. Metal ion concentrations in body fluids are surrogate measures of metal exposure. OBJECTIVE: To systematically summarize and critically appraise published studies concerning metal ion concentrations after MoM THA. METHODS: Systematic review of clinical trials (RCTs and epidemiological studies with assessment of metal ion levels (cobalt, chromium, titanium, nickel, molybdenum in body fluids after implantation of metalliferous hip replacements. Systematic search in PubMed and Embase in January 2012 supplemented by hand search. Standardized abstraction of pre- and postoperative metal ion concentrations stratified by type of bearing (primary explanatory factor, patient characteristics as well as study quality characteristics (secondary explanatory factors. RESULTS: Overall, 104 studies (11 RCTs, 93 epidemiological studies totaling 9.957 patients with measurement of metal ions in body fluids were identified and analyzed. Consistently, median metal ion concentrations were persistently elevated after implantation of MoM-bearings in all investigated mediums (whole blood, serum, plasma, erythrocytes, urine irrespective of patient characteristics and study characteristics. In several studies very high serum cobalt concentrations above 50 µg/L were measured (detection limit typically 0.3 µg/L. Highest metal ion concentrations were observed after treatment with stemmed large-head MoM-implants and hip resurfacing arthroplasty. DISCUSSION: Due to the risk of local and systemic accumulation of metallic products after treatment with MoM-bearing, risk and benefits should be carefully balanced preoperatively. The authors support a proposed "time out" for stemmed large-head MoM-THA and recommend a restricted

  14. Studies on biological effects of low energy N+ on ion beam implantation rice

    International Nuclear Information System (INIS)

    Wang Songli; Huang Qunce; Wang Tiegu; Qin Guangyong

    2006-01-01

    Dry seeds of five varieties of rice were implanted by 25 KeV low energy N + with doses of 2.0 x 10 17 , 2.5 x 10 17 and 3.0 x 10 17 N + /cm 2 , respectively. Mutant plants were selected from their progenies and the biological effects of the mutant plants were studied. The results showed that chlorophyll content of mutant plants was higher than that of the control, and one of those is as high as 148.67% of chlorophyll content compared with the control. Isoenzyme activities (POD, CAT and SOD) of mutant plants were different from the control plants. And AFLP analysis showed that the similarity between variant plants and feminine control plants was higher than that between variant plants and masculine control plants. (authors)

  15. MAK and BAT values list 2016. Maximum permissible concentrations at the place of work and biological tolerance values for working materials

    International Nuclear Information System (INIS)

    2016-01-01

    The MAK and BAT values list 2016 includes the maximum permissible concentrations at the place of work and biological tolerance values for working materials. The following working materials are covered: carcinogenic working materials, sensitizing materials and aerosols. The report discusses the restriction of exposure peaks, skin resorption, MAK (maximum working place concentration) values during pregnancy, germ cell mutagens and specific working materials. Importance and application of BAT (biological working material tolerance) values, list of materials, carcinogens, biological guide values and reference values are also included.

  16. MAK and BAT values list 2017. Maximum permissible concentrations at the place of work and biological tolerance values for working materials

    International Nuclear Information System (INIS)

    2017-01-01

    The MAK and BAT values list 2017 includes the maximum permissible concentrations at the place of work and biological tolerance values for working materials. The following working materials are covered: carcinogenic working materials, sensitizing materials and aerosols. The report discusses the restriction of exposure peaks, skin resorption, MAK (maximum working place concentration) values during pregnancy, germ cell mutagens and specific working materials. Importance and application of BAT (biological working material tolerance) values, list of materials, carcinogens, biological guide values and reference values are also included.

  17. Applicability of cloud point extraction for the separation trace amount of lead ion in environmental and biological samples prior to determination by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Sayed Zia Mohammadi

    2016-09-01

    Full Text Available A sensitive cloud point extraction procedure(CPE for the preconcentration of trace lead prior to its determination by flame atomic absorption spectrometry (FAAS has been developed. The CPE method is based on the complex of Pb(II ion with 1-(2-pyridylazo-2-naphthol (PAN, and then entrapped in the non-ionic surfactant Triton X-114. The main factors affecting CPE efficiency, such as pH of sample solution, concentration of PAN and Triton X-114, equilibration temperature and time, were investigated in detail. A preconcentration factor of 30 was obtained for the preconcentration of Pb(II ion with 15.0 mL solution. Under the optimal conditions, the calibration curve was linear in the range of 7.5 ng mL−1–3.5 μg mL−1 of lead with R2 = 0.9998 (n = 10. Detection limit based on three times the standard deviation of the blank (3Sb was 5.27 ng mL−1. Eight replicate determinations of 1.0 μg mL−1 lead gave a mean absorbance of 0.275 with a relative standard deviation of 1.6%. The high efficiency of cloud point extraction to carry out the determination of analytes in complex matrices was demonstrated. The proposed method has been applied for determination of trace amounts of lead in biological and water samples with satisfactory results.

  18. [Serial change of perilymphatic potassium ion concentration in the scala tympani after introducing KCl-solution into the guinea pigs' tympanic cavity].

    Science.gov (United States)

    Ikeno, K

    1990-09-01

    Characteristic nystagmus similar to the Meniere's attack could be observed after introducing KCl solution into the tympanic cavity of guinea pigs. To confirm the fact that this nystagmus was provoked by the high perilymphatic potassium ion concentration, the K+ activity of perilymph was recorded serially through the K+ specific microelectrode inserted into the scala tympani. The rapid increment of K+ activity reached maximum at 120 minutes after introducing KCl solution, and then it decreased gradually to a half of the maximum activity. However, such change of perilymphatic potassium ion concentration was not observed by introducing sucrose solution as control.

  19. Digital ELISA for the quantification of attomolar concentrations of Alzheimer's disease biomarker protein Tau in biological samples.

    Science.gov (United States)

    Pérez-Ruiz, Elena; Decrop, Deborah; Ven, Karen; Tripodi, Lisa; Leirs, Karen; Rosseels, Joelle; van de Wouwer, Marlies; Geukens, Nick; De Vos, Ann; Vanmechelen, Eugeen; Winderickx, Joris; Lammertyn, Jeroen; Spasic, Dragana

    2018-07-26

    The close correlation between Tau pathology and Alzheimer's disease (AD) progression makes this protein a suitable biomarker for diagnosis and monitoring of the disorder evolution. However, the use of Tau in diagnostics has been hampered, as it currently requires collection of cerebrospinal fluid (CSF), which is an invasive clinical procedure. Although measuring Tau-levels in blood plasma would be favorable, the concentrations are below the detection limit of a conventional ELISA. In this work, we developed a digital ELISA for the quantification of attomolar protein Tau concentrations in both buffer and biological samples. Individual Tau molecules were first captured on the surface of magnetic particles using in-house developed antibodies and subsequently isolated into the femtoliter-sized wells of a 2 × 2 mm 2 microwell array. Combination of high-affinity antibodies, optimal assay conditions and a digital quantification approach resulted in a 24 ± 7 aM limit of detection (LOD) in buffer samples. Additionally, a dynamic range of 6 orders of magnitude was achieved by combining the digital readout with an analogue approach, allowing quantification from attomolar to picomolar levels of Tau using the same platform. This proves the compatibility of the presented assay with the wide range of Tau concentrations encountered in different biological samples. Next, the developed digital assay was applied to detect total Tau levels in spiked blood plasma. A similar LOD (55 ± 29 aM) was obtained compared to the buffer samples, which was 5000-fold more sensitive than commercially available ELISAs and even outperformed previously reported digital assays with 10-fold increase in sensitivity. Finally, the performance of the developed digital ELISA was assessed by quantifying protein Tau in three clinical CSF samples. Here, a high correlation (i.e. Pearson coefficient of 0.99) was found between the measured percentage of active particles and the reference protein Tau

  20. Potentiometric studies on ternary complexes involving some divalent transition metal ions, gallic acid and biologically abundant aliphatic dicarboxylic acids in aqueous solutions

    Directory of Open Access Journals (Sweden)

    Abdelatty Mohamed Radalla

    2015-06-01

    Full Text Available Formation of binary and ternary complexes of the divalent transition metal ions, Cu2+, Ni2+, Co2+ and Zn2+ with gallic acid and the biologically important aliphatic dicarboxylic acids (adipic, succinic, malic, malonic, maleic, tartaric and oxalic acids were investigated by means of the potentiometric technique at 25 °C and I = 0.10 mol dm−3 NaNO3. The acid-base properties of the ligands were investigated and discussed. The acidity constants of gallic acid and aliphatic dicarboxylic acids were determined and used for determining the stability constants of the binary and ternary complexes formed in the aqueous medium under the above experimental conditions. The formation of the different 1:1 and 1:2 binary complexes and 1:1:1 ternary complexes are inferred from the corresponding potentiometric pH-metric titration curves. The ternary complex formation was found to occur in a stepwise manner. The stability constants of these binary and ternary systems were calculated. The values of Δ log K, percentage of relative stabilization (%R.S. and log X were evaluated and discussed. The concentration distribution of the various complex species formed in solution was evaluated and discussed. The mode of chelation of ternary complexes formed was ascertained by conductivity measurements.

  1. {mu}PIXE for a {mu}Brain: The vinegar fly's brain, antenna, sensilla hairs and eye ion concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Reinert, Anja, E-mail: areinert@ice.mpg.de [Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Strasse 8, 07745 Jena (Germany); Barapatre, Nirav [Institute for Experimental Physics II, University of Leipzig, Linnestrasse 5, 04103 Leipzig (Germany); Sachse, Silke [Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Strasse 8, 07745 Jena (Germany); Reinert, Tilo [Department of Physics, University of North Texas, 1155 Union Circle, 76203 Denton, TX (United States)

    2011-10-15

    The vinegar fly Drosophila melanogaster is used as model organism to study a variety of different scientific purposes. Thus, our laboratory studies the olfactory system by neurobiological experiments. These techniques are often disruptive and need to compensate or exchange the body fluid, the lymph, with an artificial Ringer's solution in defined compartments of the fly. The solution mainly contains Na, Cl, K and Ca and is to keep physiological conditions. Therefore, the knowledge about the ion concentrations in the respective Drosophila lymph is required for a correct mixture of the ions. This paper presents the spatially resolved concentrations of P, S, Cl, K, Ca, Fe, Cu and Zn in lyophilised head cryosections of Drosophila by using quantitative {mu}PIXE at the ion beam facility LIPSION in Leipzig. The PIXE maps enable a detailed analysis of particular regions of interest down to a spatial resolution of 0.5 {mu}m. We quantified the ion concentrations especially in the brain, the antenna and its sensilla hairs acting as the olfactory organ of the fly, in the compound eye and in the mouthparts. The averaged element concentrations of these main compartments are (in descending order): P: 90 mM, K: 81 mM, S: 38 mM, Cl: 18 mM, Ca: 4.9 mM, Fe: 1.4 mM, Zn: 1.2 mM, Cu: 0.06 mM. Certain structures or cavities possess a remarkably high concentration of particular elements and might reflect the different functions of the compartments. An example presented in more detail is the composition of the compound eye. Conclusively, our findings on the ion concentrations might be useful for the mixture of the Drosophila Ringer's solution to ensure physiological conditions in experiments.

  2. Determination of Trace Anions in Concentrated Hydrogen Peroxide by Direct Injection Ion Chromatography with Conductivity Detection after Pt-Catalyzed On-Line Decomposition

    International Nuclear Information System (INIS)

    Kim, Do Hee; Lee, Bo Kyung; Lee, Dong Soo

    1999-01-01

    A method has been developed for the determination of trace anion impurities in concentrated hydrogen peroxide. The method involves on-line decomposition of hydrogen peroxide, ion chromatographic separation and subsequent suppressed-type conductivity detection. H 2 O 2 is decomposed in Pt-catalyst filled Gore-Tex membrane tubing and the resulting aqueous solution containing analytes is introduced to the injection valve of an ion chromatograph for periodic determinations. The oxygen gas evolving within the membrane tubing escapes freely through the membrane wall causing no problem in ion chromatographic analysis. Decomposition efficiency is above 99.99% at a flow rate of 0.4mL/min for a 30% hydrogen peroxide concentration. Analytes are quantitatively retained. The analysis results for several brands of commercial hydrogen peroxides are reported

  3. Intra-individual biological variation in sweat chloride concentrations in CF, CFTR dysfunction, and healthy pediatric subjects.

    Science.gov (United States)

    Cirilli, Natalia; Raia, Valeria; Rocco, Ilaria; De Gregorio, Fabiola; Tosco, Antonella; Salvadori, Laura; Sepe, Angela Ornella; Buzzetti, Roberto; Minicuci, Nadia; Castaldo, Giuseppe

    2018-04-02

    The sweat test is one of the main diagnostic tools used in newborn screening programs and as a confirmatory test, in case of suspect of Cystic Fibrosis (CF). Since sweat chloride (Cl) concentration is also considered an appropriate parameter to explore the efficacy of CFTR modulators in clinical trials, it is crucial to evaluate the biological variability of this test in healthy and pathological conditions. The aim of this pilot study was to determine the intra-individual biological variability of sweat Cl, both in healthy individuals and CF patients and to assess its correlation with diet, season, and menstrual cycle. Thirty-five out of 36 selected subjects (6-18 years) were enrolled by 2 CF care centers and assigned to 3 cohorts: CF, CFTR-related disorder (CFTR-RD) and healthy volunteers. Each participant was subjected to eight sweat tests in different conditions and time of the year. Data were analyzed using linear mixed effects models for repeated measures, taking also into account intra-individual correlations. We observed a high intra-individual variability of sweat Cl, with the lowest mean CV% values among CF patients (20.21 in CF, 29.74 in CFTR-RD, and 31.15 in healthy subjects). Gender and diet had no influence on sweat Cl variability, nor had pubertal age and menstrual phase. Results of this pilot study confirmed that sweat Cl variability is high in CF patients, although non-CF individuals displayed even higher mean CV% values. Season significantly influenced sweat test values only in CF patients, likely due to changes in their hydration status. © 2018 Wiley Periodicals, Inc.

  4. Persistent after-effects of heavy rain on concentrations of ice nuclei and rainfall suggest a biological cause

    Science.gov (United States)

    Bigg, E. K.; Soubeyrand, S.; Morris, C. E.

    2015-03-01

    Rainfall is one of the most important aspects of climate, but the extent to which atmospheric ice nuclei (IN) influence its formation, quantity, frequency, and location is not clear. Microorganisms and other biological particles are released following rainfall and have been shown to serve as efficient IN, in turn impacting cloud and precipitation formation. Here we investigated potential long-term effects of IN on rainfall frequency and quantity. Differences in IN concentrations and rainfall after and before days of large rainfall accumulation (i.e., key days) were calculated for measurements made over the past century in southeastern and southwestern Australia. Cumulative differences in IN concentrations and daily rainfall quantity and frequency as a function of days from a key day demonstrated statistically significant increasing logarithmic trends (R2 > 0.97). Based on observations that cumulative effects of rainfall persisted for about 20 days, we calculated cumulative differences for the entire sequence of key days at each site to create a historical record of how the differences changed with time. Comparison of pre-1960 and post-1960 sequences most commonly showed smaller rainfall totals in the post-1960 sequences, particularly in regions downwind from coal-fired power stations. This led us to explore the hypothesis that the increased leaf surface populations of IN-active bacteria due to rain led to a sustained but slowly diminishing increase in atmospheric concentrations of IN that could potentially initiate or augment rainfall. This hypothesis is supported by previous research showing that leaf surface populations of the ice-nucleating bacterium Pseudomonas syringae increased by orders of magnitude after heavy rain and that microorganisms become airborne during and after rain in a forest ecosystem. At the sites studied in this work, aerosols that could have initiated rain from sources unrelated to previous rainfall events (such as power stations) would

  5. Immobilised metal-ion affinity chromatography purification of histidine-tagged recombinant proteins : a wash step with a low concentration of EDTA

    NARCIS (Netherlands)

    Westra, DF; Welling, GW; Koedijk, DGAM; Scheffer, AJ; The, TH; Welling-Wester, S

    2001-01-01

    Immobilised metal-ion affinity chromatography (IMAC) is widely used for the purification of recombinant proteins in which a poly-histidine tag is introduced. However, other proteins may also bind to IMAC columns. We describe the use of a washing buffer with a low concentration of EDTA (0.5 mM) for

  6. Simultaneous determination of free calcium, magnesium, sodium and potassium ion concentrations in simulated milk ultrafiltrate and reconstituted skim milk using the Donnan Membrane Technique

    NARCIS (Netherlands)

    Gao, R.; Temminghoff, E.J.M.; Leeuwen, van H.P.; Valenberg, van H.J.F.; Eisner, M.D.; Boekel, van M.A.J.S.

    2009-01-01

    This study focused on determination of free Ca2+, Mg2+, Na+ and K+ concentrations in a series of CaCl2 solutions, simulated milk ultrafiltrate and reconstituted skim milk using a recently developed Donnan Membrane Technique (DMT). A calcium ion selective electrode was used to compare the DMT

  7. A New Approach to Studying Biological and Soft Materials Using Focused Ion Beam Scanning Electron Microscopy (FIB SEM)

    International Nuclear Information System (INIS)

    Stokes, D J; Morrissey, F; Lich, B H

    2006-01-01

    Over the last decade techniques such as confocal light microscopy, in combination with fluorescent labelling, have helped biologists and life scientists to study biological architectures at tissue and cell level in great detail. Meanwhile, obtaining information at very small length scales is possible with the combination of sample preparation techniques and transmission electron microscopy (TEM) or scanning transmission electron microscopy (STEM). Scanning electron microscopy (SEM) is well known for the determination of surface characteristics and morphology. However, the desire to understand the three dimensional relationships of meso-scale hierarchies has led to the development of advanced microscopy techniques, to give a further complementary approach. A focused ion beam (FIB) can be used as a nano-scalpel and hence allows us to reveal internal microstructure in a site-specific manner. Whilst FIB instruments have been used to study and verify the three-dimensional architecture of man made materials, SEM and FIB technologies have now been brought together in a single instrument representing a powerful combination for the study of biological specimens and soft materials. We demonstrate the use of FIB SEM to study three-dimensional relationships for a range of length scales and materials, from small-scale cellular structures to the larger scale interactions between biomedical materials and tissues. FIB cutting of heterogeneous mixtures of hard and soft materials, resulting in a uniform cross-section, has proved to be of particular value since classical preparation methods tend to introduce artefacts. Furthermore, by appropriate selection, we can sequentially cross-section to create a series of 'slices' at specific intervals. 3D reconstruction software can then be used to volume-render information from the 2D slices, enabling us to immediately see the spatial relationships between microstructural components

  8. Uranium Isotopes in Calcium Carbonate: A Possible Proxy for Paleo-pH and Carbonate Ion Concentration?

    Science.gov (United States)

    Chen, X.; Romaniello, S. J.; Herrmann, A. D.; Wasylenki, L. E.; Anbar, A. D.

    2015-12-01

    Natural variations of 238U/235U in marine carbonates are being explored as a paleoredox proxy. However, in order for this proxy to be robust, it is important to understand how pH and alkalinity affect the fractionation of 238U/235U during coprecipitation with calcite and aragonite. Recent work suggests that the U/Ca ratio of foraminiferal calcite may vary with seawater [CO32-] concentration due to changes in U speciation[1]. Here we explore analogous isotopic consequences in inorganic laboratory co-precipitation experiments. Uranium coprecipitation experiments with calcite and aragonite were performed at pH 8.5 ± 0.1 and 7.5 ± 0.1 using a constant addition method [2]. Dissolved U in the remaining solution was periodically collected throughout the experiments. Samples were purified with UTEVA resin and 238U/235U was determined using a 233U-236U double-spike and MC-ICP-MS, attaining a precision of ± 0.10 ‰ [3]. Small but resolvable U isotope fractionation was observed in aragonite experiments at pH ~8.5, preferentially enriching heavier U isotopes in the solid phase. 238U/235U of the dissolved U in these experiments can be fit by Rayleigh fractionation curves with fractionation factors of 1.00002 - 1.00009. In contrast, no resolvable U isotope fractionation was detected in an aragonite experiment at pH ~7.5 or in calcite experiments at either pH. Equilibrium isotope fractionation among dissolved U species is the most likely mechanism driving these isotope effects. Our quantitative model of this process assumes that charged U species are preferentially incorporated into CaCO3 relative to the neutral U species Ca2UO2(CO3)3(aq), which we hypothesize to have a lighter equilibrium U isotope composition than the charged U species. According to this model, the magnitude of U isotope fractionation should scale with the fraction of the neutral U species in the solution, in agreement with our experimental results. These findings suggest that U isotope variations in

  9. A single low dose of Fe ions can cause long-term biological responses in NL20 human bronchial epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Qianlin; Wang, Jingdong; Cao, Jianping; Yang, Hongying [Medical College of Soochow University/Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, School of Radiation Medicine and Protection, Suzhou, Jiangsu (China); Liu, Wei [Soochow University, Department of Radiotherapy and Oncology, Second Affiliated Hospital, Suzhou, Jiangsu (China)

    2018-03-15

    Space radiation cancer risk may be a potential obstacle for long-duration spaceflight. Among all types of cancer space radiation may induce, lung cancer has been estimated to be the largest potential risk. Although previous animal study has shown that Fe ions, the most important contributor to the total dose equivalent of space radiation, induced a higher incidence of lung tumorigenesis per dose than X-rays, the underlying mechanisms at cellular level remained unclear. Therefore, in the present study, we investigated long-term biological changes in NL20 human bronchial epithelial cells after exposure to Fe ion or X-ray irradiation. We found that compared with sham control, the progeny of NL20 cells irradiated with 0.1 Gy of Fe ions showed slightly increased micronucleus formation, significantly decreased cell proliferation, disturbed cell cycle distribution, and obviously elevated intracellular ROS levels accompanied by reduced SOD1 and SOD2 expression, but the progeny of NL20 cells irradiated with 0.9 Gy of X-rays did not show any significant changes. More importantly, Fe ion exposure caused much greater soft-agar colony formation than X-rays did in the progeny of irradiated NL20 cells, clearly suggesting higher cell transformation potential of Fe ions compared with X-rays. These data may shed the light on the potential lung tumorigenesis risk from Fe ion exposure. In addition, ATM inhibition by Ku55933 reversed some of the changes in the progeny of Fe ion-irradiated cells but not others such as soft-agar colony formation, suggesting complex processes from DNA damage to carcinogenesis. These data indicate that even a single low dose of Fe ions can induce long-term biological responses such as cell transformation, etc., suggesting unignorable health risk from space radiation to astronauts. (orig.)

  10. Direct measurement of the concentration of metastable ions produced from neutral gas particles using laser-induced fluorescence

    Science.gov (United States)

    Chu, Feng; Skiff, Fred; Berumen, Jorge; Mattingly, Sean; Hood, Ryan

    2017-10-01

    Extensive information can be obtained on wave-particle interactions and wave fields by direct measurement of perturbed ion distribution functions using laser-induced fluorescence (LIF). For practical purposes, LIF is frequently performed on metastables that are produced from neutral gas particles and existing ions in other electronic states. We numerically simulate the ion velocity distribution measurement and wave-detection process using a Lagrangian model for the LIF signal. The results show that under circumstances where the metastable ion population is coming directly from the ionization of neutrals (as opposed to the excitation of ground-state ions), the velocity distribution will only faithfully represent processes which act on the ion dynamics in a time shorter than the metastable lifetime. Therefore, it is important to know the ratio of metastable population coming from neutrals to that from existing ions to correct the LIF measurements of plasma ion temperature and electrostatic waves. In this paper, we experimentally investigate the ratio of these two populations by externally launching an ion acoustic wave and comparing the wave amplitudes that are measured with LIF and a Langmuir probe using a lock-in amplifier. DE-FG02-99ER54543.

  11. Nicotine dose-concentration relationship and pregnancy outcomes in rat: Biologic plausibility and implications for future research

    International Nuclear Information System (INIS)

    Hussein, Jabeen; Farkas, Svetlana; MacKinnon, Yolanda; Ariano, Robert E.; Sitar, Daniel S.; Hasan, Shabih U.

    2007-01-01

    Cigarette smoke (CS) exposure during pregnancy can lead to profound adverse effects on fetal development. Although CS contains several thousand chemicals, nicotine has been widely used as its surrogate as well as in its own right as a neuroteratogen. The justification for the route and dose of nicotine administration is largely based on inferential data suggesting that nicotine 6 mg/kg/day infused continuously via osmotic mini pumps (OMP) would mimic maternal CS exposure. We provide evidence that 6 mg/kg/day nicotine dose as commonly administered to pregnant rats leads to plasma nicotine concentrations that are 3-10-fold higher than those observed in moderate to heavy smokers and pregnant mothers, respectively. Furthermore, the cumulative daily nicotine dose exceeds by several hundred fold the amount consumed by human heavy smokers. Our study does not support the widely accepted notion that regardless of the nicotine dose, a linear nicotine dose-concentration relationship exists in a steady-state OMP model. We also show that total nicotine clearance increases with advancing pregnancy but no significant change is observed between the 2nd and 3rd trimester. Furthermore, nicotine infusion even at this extremely high dose has little effect on a number of maternal and fetal biologic variables and pregnancy outcome suggesting that CS constituents other than nicotine mediate the fetal growth restriction in infants born to smoking mothers. Our current study has major implications for translational research in developmental toxicology and pharmacotherapy using nicotine replacement treatment as an aid to cessation of cigarette smoking in pregnant mothers

  12. The Biological Effectiveness of Four Energies of Neon Ions for the Induction of Chromosome Damage in Human Lymphocytes

    Science.gov (United States)

    George, Kerry; Hada, Megumi; Cucinotta, F. A.

    2011-01-01

    Chromosomal aberrations were measured in human peripheral blood lymphocytes after in vitro exposure to neon ions at energies of 64, 89, 142, or 267. The corresponding LET values for these energies of neon ranged from 38-103 keV/micrometers and doses delivered were in the 10 to 80 cGy range. Chromosome exchanges were assessed in metaphase and G2 phase cells at first division after exposure using fluorescence in situ hybridization (FISH) with whole chromosome probes and dose response curves were generated for different types of chromosomal exchanges. The yields of total chromosome exchanges were similar for the 64, 89, and 142 MeV exposures, whereas the 267 MeV/u neon with LET of 38 keV/micrometers produced about half as many exchanges per unit dose. The induction of complex type chromosome exchanges (exchanges involving three or more breaks and two or more chromosomes) showed a clear LET dependence for all energies. The ratio of simple to complex type exchanges increased with LET from 18 to 51%. The relative biological effectiveness (RBE) was estimated from the initial slope of the dose response curve for chromosome damage with respect to gamma-rays. The RBE(sub max) values for total chromosome exchanges for the 64 MeV/u was around 30.

  13. Study of the interaction of multiply charged ions and complex systems of biological interest: effects of the molecular environment

    International Nuclear Information System (INIS)

    Capron, Michael

    2011-01-01

    This PhD thesis describes the experimental study of the interaction between slow multiply charged ions (tens of keV) and molecular systems of biological interest (amino acids and nucleobases). It is the aim to identify and to better understand the effect of a molecular environment on different collision induced phenomena. To do so, the time of flight spectra of cationic products emerging from collisions with isolated molecules as well as clusters are compared. It is shown that the molecular environment protects the molecule as it allows to distribute the transferred energies and charges over the whole system (global decrease of the fragmentation and quenching of some fragmentation channels). Furthermore, in the case of adenine clusters, the molecular environment weakens some intramolecular bonds. Moreover, products of chemical reactions are observed concerning proton transfer processes in hydrated cluster of adenine and the formation of peptides bonds between beta-alanine molecules in a cluster. The latter finding is studied as a function of the cluster size and type of the projectile. Some criteria for peptide bond formation, such as flexibility and geometry of the molecule, are investigated for different amino acids. (author)

  14. Synthesis, Characterization and Spectral Studies of Noble Heterobinuclear Complexes of Transition Metal Ions and their Biological Activity

    Directory of Open Access Journals (Sweden)

    Netra Pal Singh

    2011-01-01

    Full Text Available Some noble heterobinuclear complexes of transition metal ions with bis(salicylaldehydemalonyl-dihydrazone in the presence of 5-nitroindazole Cu(II / Ni(II- chloride of the type [ML1M‘L2Cl2] or [ML1FeL2Cl2]Cl, where M = Ni(II, Cu(II and M' = Mn(II, Co(II, have been prepared. All the complexes have been characterized by IR, UV vis and EPR spectroscopy, elemental analysis, magnetic moment and molar conductance measurement. Spectral studies and magnetic moment measurement in DMF suggest the covalent nature of the complexes, except the [ML1FeL2Cl2]Cl complex which is 1:1 electrolyte. An octahedral geometry is proposed for M‘ and square planer for M for the heterobinuclear complexes. The low value of magnetic moment and overlapping EPR signals are due to spin crossover since both of the metals have unpaired electrons with same molecular symmetry. The lowering of the magnetic moment has been discussed. The biological activity (antifungal and antibacterial of the represented compounds has been studied.

  15. Kinetic energy distributions of ions after surface collisions

    International Nuclear Information System (INIS)

    Short, R.T.; Todd, P.J.; Grimm, C.C.

    1991-01-01

    As a part of the development of an organic ion microprobe, to be used for imaging of particular organic compounds in biological tissue, various methods of quadrupole-based tandem mass spectroscopy (MS/MS) have been investigated. High transmission efficiency is essential for the success of the organic ion microprobe, due to expected low analyte concentrations in biological tissue and the potential for sample damage from prolonged exposure to the primary ion beam. MS/MS is necessary for organic ion imaging because of the complex nature of the biological matrices. The goal of these studies of was to optimize the efficiency of daughter ion production and transmission by first determining daughter ion properties and then designing ion optics based on those properties. The properties of main interest are daughter ion kinetic energy and angular distribution. 1 fig

  16. Raman spectroscopy for the evaluation of the effects of different concentrations of Copper on the chemical composition and biological activity of basil essential oil

    Science.gov (United States)

    Nawaz, Haq; Hanif, Muhammad Asif; Ayub, Muhammad Adnan; Ishtiaq, Faiqa; Kanwal, Nazish; Rashid, Nosheen; Saleem, Muhammad; Ahmad, Mushtaq

    2017-10-01

    The present study is performed to evaluate the effect of different concentrations of Cu as fertilizer on the chemical composition of basil essential oil and its biological activity including antioxidant and antifungal activities by employing Raman spectroscopy. Moreover, the effect of Cu is also determined on the vegetative growth and essential oil yield. Both, antifungal and antioxidant activities were found to be maximum with essential oils obtained at 0.04 mg/l concentration of Cu fertilizer. The results of the GC-MS and Raman spectroscopy have revealed that the linalool and estragole are found to be as a major chemical compound in basil essential oil. The Raman spectral changes associated with these biological components lead to the conclusion that estragole seems to have dominating effect in the biological activities of the basil essential oil as compared to linalool although the latter is observed in greater concentration.

  17. Entry of Nd+3 ions into the LiYF4 matrix and determination of Nd+3 concentration by the nondestructing spectrophotometric method

    International Nuclear Information System (INIS)

    Tkachuk, A.M.; Poletimova, A.V.; Petrova, M.A.; Egorov, V.Yu.; Korolev, N.E.

    1991-01-01

    Entering of Nd 3+ ions into LiYF 4 lattice was investigation. Nondestructive spectrophotometric method for determining activator concentration in the crystal was developed. It enables to determine both the average integral concentration in the active element. Absorption cross sections were determined for a series of reference lines λ i with the lowest polarization degree. Values of β(λ i ) coefficients, enabling to determine the average neodymium concentration in the sample, are presented. Coefficient of neodymium entering into LiYF 4 lattice was determined: K nd =0.31+-0.02

  18. Behaviour of the pH adjustment, Ion exchange and concentrate precipitation stages in the acid leaching of uranium phosphate ores

    International Nuclear Information System (INIS)

    Estrada Aguilar, J.; Uriarte Hueda, A.

    1962-01-01

    The uranium recovery from acid leach solutions of uranium-phosphate ores has been studied. Relations have been found between the solution characteristics and the results obtained at different stages of the process. The following data can thus be predicted: solids to remove and uranium recovery in the pH adjustment stage, uranium capacity of the resin, more suitable eluating agent, elution velocity and uranium concentration in the eluate in the ion exchange stage, and composition of the concentrate produced by direct precipitation of the eluate in the concentrate precipitation stage. (Author) 8 refs

  19. Effect of low-oxygen-concentration layer on iron gettering capability of carbon-cluster ion-implanted Si wafer for CMOS image sensors

    Science.gov (United States)

    Onaka-Masada, Ayumi; Nakai, Toshiro; Okuyama, Ryosuke; Okuda, Hidehiko; Kadono, Takeshi; Hirose, Ryo; Koga, Yoshihiro; Kurita, Kazunari; Sueoka, Koji

    2018-02-01

    The effect of oxygen (O) concentration on the Fe gettering capability in a carbon-cluster (C3H5) ion-implanted region was investigated by comparing a Czochralski (CZ)-grown silicon substrate and an epitaxial growth layer. A high Fe gettering efficiency in a carbon-cluster ion-implanted epitaxial growth layer, which has a low oxygen region, was observed by deep-level transient spectroscopy (DLTS) and secondary ion mass spectroscopy (SIMS). It was demonstrated that the amount of gettered Fe in the epitaxial growth layer is approximately two times higher than that in the CZ-grown silicon substrate. Furthermore, by measuring the cathodeluminescence, the number of intrinsic point defects induced by carbon-cluster ion implantation was found to differ between the CZ-grown silicon substrate and the epitaxial growth layer. It is suggested that Fe gettering by carbon-cluster ion implantation comes through point defect clusters, and that O in the carbon-cluster ion-implanted region affects the formation of gettering sinks for Fe.

  20. Influence of NO2 and metal ions on oxidation of aqueous-phase S(IV in atmospheric concentrations

    Directory of Open Access Journals (Sweden)

    Cláudia R. Martins

    2008-06-01

    Full Text Available An investigation was made of the influence of atmospheric concentrations (15 or 130 ppbv of NO2 on the aqueous-phase oxidation rate of S(IV in the presence and absence of Fe(III, Mn(II and Cr(VI metal ions under controlled experimental conditions (pH, T, concentration of reactants, etc.. The reaction rate in the presence of the NO2 flow was slower than the reaction rate using only clean air with an initial S(IV concentration of 10-4 mol/L. NO2 appears to react with S(IV, producing a kind of inhibitor that slows down the reaction. Conversely, tenfold lower concentrations of S(IV ([S(IV]º = 10-5 mol/L caused a faster reaction in the presence of NO2 than the reaction using purified air. Under these conditions, therefore, the equilibrium shifts to sulfate formation. With the addition of Fe(III, Mn(II or Cr(VI in the presence of a NO2 flow, the reaction occurred faster under all the conditions in which S(IV oxidation was investigated.A reação de oxidação de S(IV em fase aquosa foi estudada em laboratório em presença de NO2 dos íons metálicos Fe(III, Mn(II, e Cr(VI sob condições experimentais controladas (pH, T, concentração dos reagentes, etc.. Na presença de corrente de ar com NO2 (15 ou 130 ppbv a reação de oxidação de S(IV ocorreu mais lentamente do que na presença de ar purificado, para uma concentração inicial de S(IV de 10-4 mol/L. Ao contrário, para concentração inicial de S(IV dez vezes menor ([S(IV]° = 10-5 mol/L a reação ocorreu mais rapidamente na presença de NO2. A explicação está relacionada com o equilíbrio envolvendo a formação de espécies intermediárias de longa vida, que impedem o prosseguimento da reação, porém a depender das concentrações relativas de S(IV e NO2, essas espécies se decompõem deslocando o equilíbrio no sentido de formação de sulfato. A adição dos íons Fe(III, Mn(II ou Cr(VI em presença de corrente de ar com NO2 indicou atividade catalítica para esses íons, em todas

  1. Effect of DSPE-PEG on compound action potential, injury potential and ion concentration following compression in ex vivo spinal cord.

    Science.gov (United States)

    Wang, Aihua; Huo, Xiaolin; Zhang, Guanghao; Wang, Xiaochen; Zhang, Cheng; Wu, Changzhe; Rong, Wei; Xu, Jing; Song, Tao

    2016-05-04

    It has been shown that polyethylene glycol (PEG) can reseal membrane disruption on the spinal cord, but only high concentrations of PEG have been shown to have this effect. Therefore, the effect of PEG is somewhat limited, and it is necessary to investigate a new approach to repair spinal cord injury. This study assesses the ability of 1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly (ethylene glycol)) 2000] (DSPE-PEG) to recover physiological function and attenuate the injury-induced influx of extracellular ions in ex vivo spinal cord injury. Isolated spinal cords were subjected to compression injury and treated with PEG or DSPE-PEG immediately after injury. The compound action potential (CAP) was recorded before and after injury to assess the functional recovery. Furthermore, injury potential, the difference in gap potentials before and after compression, and the concentration of intracellular ions were used to evaluate the effect of DSPE-PEG on reducing ion influx. Data showed that the injury potential and ion concentration of the untreated, PEG and DSPE-PEG group, without significant difference among them, are remarkably higher than those of the intact group. Moreover, the CAP recovery of the DSPE-PEG and PEG treated spinal cords was significantly greater than that of the untreated spinal cords. The level of CAP recovery in the DSPE-PEG and PEG treated groups was the same, but the concentration of DSPE-PEG used was much lower than the concentration of PEG. These results suggest that instant application of DSPE-PEG could effectively repair functional disturbance in SCI at a much lower concentration than PEG. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Time‐of‐flight secondary ion mass spectrometry imaging of biological samples with delayed extraction for high mass and high spatial resolutions

    Science.gov (United States)

    Vanbellingen, Quentin P.; Elie, Nicolas; Eller, Michael J.; Della‐Negra, Serge; Touboul, David

    2015-01-01

    Rationale In Time‐of‐Flight Secondary Ion Mass Spectrometry (TOF‐SIMS), pulsed and focused primary ion beams enable mass spectrometry imaging, a method which is particularly useful to map various small molecules such as lipids at the surface of biological samples. When using TOF‐SIMS instruments, the focusing modes of the primary ion beam delivered by liquid metal ion guns can provide either a mass resolution of several thousand or a sub‐µm lateral resolution, but the combination of both is generally not possible. Methods With a TOF‐SIMS setup, a delayed extraction applied to secondary ions has been studied extensively on rat cerebellum sections in order to compensate for the effect of long primary ion bunches. Results The use of a delayed extraction has been proven to be an efficient solution leading to unique features, i.e. a mass resolution up to 10000 at m/z 385.4 combined with a lateral resolution of about 400 nm. Simulations of ion trajectories confirm the experimental determination of optimal delayed extraction and allow understanding of the behavior of ions as a function of their mass‐to‐charge ratio. Conclusions Although the use of a delayed extraction has been well known for many years and is very popular in MALDI, it is much less used in TOF‐SIMS. Its full characterization now enables secondary ion images to be recorded in a single run with a submicron spatial resolution and with a mass resolution of several thousand. This improvement is very useful when analyzing lipids on tissue sections, or rare, precious, or very small size samples. © 2015 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd. PMID:26395603

  3. Effect of Ion Concentration Changes in the Limited Extracellular Spaces on Sarcolemmal Ion Transport and Ca2+ Turnover in a Model of Human Ventricular Cardiomyocyte

    Czech Academy of Sciences Publication Activity Database

    Hrabcová, D.; Pásek, Michal; Šimurda, J.; Christé, G.

    2013-01-01

    Roč. 14, č. 12 (2013), s. 24271-24292 E-ISSN 1422-0067 Grant - others:GA MZd(CZ) NT14301 Institutional support: RVO:61388998 Keywords : human heart * cardiac cell * t-tubule * intercellular clefts * calcium * ion transport * computer model Subject RIV: BO - Biophysics Impact factor: 2.339, year: 2013

  4. Studies on Pu(IV)/(III)-oxalate precipitation from nitric acid containing high concentration of calcium and fluoride ions

    International Nuclear Information System (INIS)

    Kalsi, P.K.; Pawar, S.M.; Ghadse, D.R.; Joshi, A.R.; Ramakrishna, V.V.; Vaidya, V.N.; Venugopal, V.

    2003-01-01

    Plutonium (IV)/(III) oxalate precipitation from nitric acid solution, containing large amount of calcium and fluoride ions was investigated. It was observed that direct precipitation of Pu (IV) oxalate from nitric acid containing large amount of calcium and fluoride ions did not give good decontamination of Pu from calcium and fluoride impurities. However, incorporation of hydroxide precipitation using ammonium hydroxide prior to Pu (IV) oxalate precipitation results into PuO 2 with much less calcium and fluoride impurities. Whereas, good decontamination from calcium and fluoride impurities could be obtained by employing Pu (III) oxalate precipitation directly from nitric acid containing large amount of calcium and fluoride ions. A method was also developed to recover Pu from the oxalate waste containing calcium and fluoride ions. (author)

  5. Determination of hexavalent chromium concentration in industrial waste incinerator stack gas by using a modified ion chromatography with post-column derivatization method.

    Science.gov (United States)

    Miyake, Yuichi; Tokumura, Masahiro; Iwazaki, Yuta; Wang, Qi; Amagai, Takashi; Horii, Yuichi; Otsuka, Hideyuki; Tanikawa, Noboru; Kobayashi, Takeshi; Oguchi, Masahiro

    2017-06-16

    An ion chromatography with post-column derivatization with 1,5-diphenylcarbazide (IC-DPC) analytical method was modified to enable measurement of trace-level hexavalent chromium (Cr(VI)) in air. One of the difficulties in determining trace levels of Cr(VI) in air with conventional IC-DPC methods is co-elution of the solvent and ion peaks due to high concentrations of ionic compounds in the extract. However, by using gradient elution rather than isocratic elution we were able to fully resolve the Cr(VI) ion peak from the solvent peak without the need for diluting the extract, which would have reduced the minimum quantifiable level of the method. With this method, we were able to detect Cr(VI) in air at concentrations of 5.3ng/m 3 (assuming a sampling volume of 1m 3 and a final solution volume of 10mL). Recovery tests at three different concentrations of Cr(VI) (50, 250, 1000ng) were performed with or without fly ash; recovery rates at all the concentrations of Cr(VI), with or without fly ash, ranged from 68% to 110% (mean±relative standard deviation, 96%±11%), and there were no differences in recovery rates with respect to the presence or absence of fly ash. Finally, we used the developed method to determine the concentration of Cr(VI) in stack gases collected from eight industrial waste incinerators located in Japan. The concentration of Cr(VI) in the stack gases ranged from below the method quantification limit to 3100ng/m 3 . The highest concentrations of Cr(VI) detected in the stack gases were two to three orders of magnitude higher than that in ambient air in Japan. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. To measure ammonia and the ammonium-ion in high concentrations with sensitrodes; Messreihen mit Ammoniak- und Ammonium-Sensitroden in ungewoehnlich hohen Konzentrationsbereichen

    Energy Technology Data Exchange (ETDEWEB)

    Brosche, P. [DBI-EWI GmbH, Freiberg (Germany)

    1996-08-01

    Ammonia up to 8 Mol/kg and the ammonium-ion up to 5 Mol/kg were investigated by sensitrodes. Sensitrodes of different manufacturers, the influence of different salts, the temperature (25 and 50 C) and ammonia in mixture with the ammonium-ion were assessed in respect of the result for measuring. The functional correlation between the pH-value and the logarithmus for the ratio of ammonium-ion to ammonia in respect of the equation from Henderson and Hasselbalch was examined. The given concentration for ammonia respectively the ammonium-ion was compared with the calculated concentration of the calibration curve. The investigated sensitrodes may be installed in the manufacturing of ammonium salts in mixture with ammonia as measuring and controlling unit. (orig.) [Deutsch] Ammoniak bis 8 mol/kg und das Ammoniumion bis 5 mol/kg wurden mittels Sensitroden untersucht. Bewertet wurden Sensitroden verschiedener Hersteller, der Einfluss von Salzen, der Temperatur (25 und 50 C) und Ammoniak im Gemisch mit dem Ammoniumion auf das Messergebnis. Der funktionale Zusammenhang zwischen dem pH-Wert und dem Logarithmus des Verhaeltnisses von Ammoniumion und Ammoniak entsprechend der Gleichung von Henderson und Hasselbalch wurde untersucht. Die eingegebenen Konzentrationen an Ammoniak bzw. des Ammoniumions wurden mit den aus den Kalibrierungskurven errechneten Konzentrationen verglichen. Die untersuchten Sensitroden koennen in der Produktion von Ammoniumsalzen im Gemisch mit Ammoniak als Mess- und Steuergeraet eingesetzt werden. (orig.)

  7. Energy recovery from effluents of sugar processing industries in the UASB reactors seeded with granular sludge developed under low and high concentrations of calcium ion

    Energy Technology Data Exchange (ETDEWEB)

    Raphael, D M; Rubindamayugi, M S.T. [Univ. of Dar es Salaam, Dept. of Botany, Applied Microbiology Unit (Tanzania, United Republic of)

    1998-12-31

    The digestion of wastewater from sugar processing industries in a single phase UASB reactor was evaluated by a step wise increase in organic loading rate. This study was conducted to compare the treatability of effluents from sugar processing industries in a single phase UASB reactors inoculated with granular sludge developed under low and high concentrations of calcium ions. At OLR of 11.34 g COD/l/day and HRT of 16 hours, UASB reactor R2 attained a COD removal efficiency of 90% with a maximum methane production rate of 3 l/l/day. From the results, the digestion of the wastewater from sugar industries in the UASB reactor inoculated with granular sludge developed under high calcium ion concentration seem feasible with regard to COD removal efficiency and methane production rate. (au) 24 refs.

  8. Energy recovery from effluents of sugar processing industries in the UASB reactors seeded with granular sludge developed under low and high concentrations of calcium ion

    Energy Technology Data Exchange (ETDEWEB)

    Raphael, D.M.; Rubindamayugi, M.S.T. [Univ. of Dar es Salaam, Dept. of Botany, Applied Microbiology Unit (Tanzania, United Republic of)

    1997-12-31

    The digestion of wastewater from sugar processing industries in a single phase UASB reactor was evaluated by a step wise increase in organic loading rate. This study was conducted to compare the treatability of effluents from sugar processing industries in a single phase UASB reactors inoculated with granular sludge developed under low and high concentrations of calcium ions. At OLR of 11.34 g COD/l/day and HRT of 16 hours, UASB reactor R2 attained a COD removal efficiency of 90% with a maximum methane production rate of 3 l/l/day. From the results, the digestion of the wastewater from sugar industries in the UASB reactor inoculated with granular sludge developed under high calcium ion concentration seem feasible with regard to COD removal efficiency and methane production rate. (au) 24 refs.

  9. Changes in the Concentration of Ions in Saliva and Dental Plaque after Application of CPP-ACP with and without Fluoride among 6-9 Year Old Children

    Directory of Open Access Journals (Sweden)

    Poureslami H

    2017-03-01

    Full Text Available Statement of Problem: The casein phospho peptide-amorphous calcium phosphate with or without fluoride (CPP-ACPF and CPP-ACP respectively are of considerably new materials which are highly recommended for prevention of dental caries. However, there is a shortage in literature on how they affect the ion concentration of saliva or dental plaque. Objectives: The aim of this study was to evaluate the concentration of calcium, phosphate and fluoride in the plaque and saliva of children with Early Childhood Caries (ECC after applying the CPP-ACP paste in comparison with the use of CPP- ACPF paste. Materials and Methods: One ml of un-stimulated saliva of 25 preschool children was collected and then 1 mg of the plaque sample was collected from the buccal surfaces of the two first primary molars on the upper jaw. CPP-ACP as well as CPP- ACPF pastes were applied on the tooth surfaces in two separate steps. In steps, plaque and saliva sampling was performed after 60 minutes. The amount of calcium ions was measured by Atomic Absorption Device and the amount of phosphate and fluoride ions was measured by Ion Chromatography instrument. Data were analyzed using Repeated Measurements ANOVA at a p < 0.05 level of significance. Results: Application of both CPP-ACPF and CPP-ACP significantly increased the concentration of calcium, phosphate, and fluoride in both saliva and dental plaque. Moreover, significantly higher salivary fluoride concentration was seen after application of CPP-ACPF compared to CPP-ACP. No other significant difference was observed between these two materials. Conclusions: CPP-ACPF can be more useful than CPP-ACP in protecting the primary teeth against caries process, especially when there is poor hygiene.

  10. Changes in the Concentration of Ions in Saliva and Dental Plaque after Application of CPP-ACP with and without Fluoride among 6-9 Year Old Children.

    Science.gov (United States)

    Poureslami, H; Hoseinifar, Ra; Khazaeli, P; Hoseinifar, Re; Sharifi, H; Poureslami, P

    2017-03-01

    The casein phospho peptide-amorphous calcium phosphate with or without fluoride (CPP-ACPF and CPP-ACP respectively) are of considerably new materials which are highly recommended for prevention of dental caries. However, there is a shortage in literature on how they affect the ion concentration of saliva or dental plaque. The aim of this study was to evaluate the concentration of calcium, phosphate and fluoride in the plaque and saliva of children with Early Childhood Caries (ECC) after applying the CPP-ACP paste in comparison with the use of CPP-ACPF paste. One ml of un-stimulated saliva of 25 preschool children was collected and then 1 mg of the plaque sample was collected from the buccal surfaces of the two first primary molars on the upper jaw. CPP-ACP as well as CPP-ACPF pastes were applied on the tooth surfaces in two separate steps. In steps, plaque and saliva sampling was performed after 60 minutes. The amount of calcium ions was measured by Atomic Absorption Device and the amount of phosphate and fluoride ions was measured by Ion Chromatography instrument. Data were analyzed using Repeated Measurements ANOVA at a p Application of both CPP-ACPF and CPP-ACP significantly increased the concentration of calcium, phosphate, and fluoride in both saliva and dental plaque. Moreover, significantly higher salivary fluoride concentration was seen after application of CPP-ACPF compared to CPP-ACP. No other significant difference was observed between these two materials. CPP-ACPF can be more useful than CPP-ACP in protecting the primary teeth against caries process, especially when there is poor hygiene.

  11. Dopant-assisted negative photoionization Ion mobility spectrometry coupled with on-line cooling inlet for real-time monitoring H2S concentration in sewer gas.

    Science.gov (United States)

    Peng, Liying; Jiang, Dandan; Wang, Zhenxin; Hua, Lei; Li, Haiyang

    2016-06-01

    Malodorous hydrogen sulfide (H2S) gas often exists in the sewer system and associates with the problems of releasing the dangerous odor to the atmosphere and causing sewer pipe to be corroded. A simple method is in demand for real-time measuring H2S level in the sewer gas. In this paper, an innovated method based on dopant-assisted negative photoionization ion mobility spectrometry (DANP-IMS) with on-line semiconductor cooling inlet was put forward and successfully applied for the real-time measurement of H2S in sewer gas. The influence of moisture was effectively reduced via an on-line cooling method and a non-equilibrium dilution with drift gas. The limits of quantitation for the H2S in ≥60% relative humidity air could be obtained at ≤79.0ng L(-1) with linear ranges of 129-2064ng L(-1). The H2S concentration in a sewer manhole was successfully determined while its product ions were identified by an ion-mobility time-of-fight mass spectrometry. Finally, the correlation between sewer H2S concentration and the daily routines and habits of residents was investigated through hourly or real-time monitoring the variation of sewer H2S in manholes, indicating the power of this DANP-IMS method in assessing the H2S concentration in sewer system. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Cytological comparison of gill chloride cells and blood serum ion concentrations in kutum (Rutilus frisii kutum spawners from brackish (Caspian Sea and fresh water (Khoshkrood River environments

    Directory of Open Access Journals (Sweden)

    Ghahremanzadeh Zahra

    2014-09-01

    Full Text Available The size and number of chloride cells and serum ion concentrations in kutum, Rutillus frisii kutum Nordman, from brackish (Caspian Sea and fresh water (Khoshkrood River environments were studied to gain a better understanding of osmoregulation in this species. Twenty mature kutum specimens were collected from the Caspian Sea (Anzali coasts, 8.49 ppt salinity and 12.4°C temperature and 20 specimens from Khoshkrood River (0.18 ppt salinity and 18°C temperature. Gill samples were analyzed histologically and concentrations of Na+, Cl- , K+, and Mg2+ ions were determined in the blood serum. Concentrations of Na+, Cl- , K+, and Mg2+ ions and osmotic pressure in mature kutum from brackish water were significantly higher than in specimens from fresh water. The average size and number of chloride cells in the fish from seawater were considerably larger than those from fresh water. The mean size of chloride cells was 6.89 ± 1.16 μm in brackish water samples and 5.1 ± 0.81 μm in river samples. The average number of chloride cells in brackish and river water samples were 16.92 and 6.57, respectively. The density and size of chloride cells increased with increases in salinity

  13. A hydrogen-ferric ion rebalance cell operating at low hydrogen concentrations for capacity restoration of iron-chromium redox flow batteries

    Science.gov (United States)

    Zeng, Y. K.; Zhao, T. S.; Zhou, X. L.; Zou, J.; Ren, Y. X.

    2017-06-01

    To eliminate the adverse impacts of hydrogen evolution on the capacity of iron-chromium redox flow batteries (ICRFBs) during the long-term operation and ensure the safe operation of the battery, a rebalance cell that reduces the excessive Fe(III) ions at the positive electrolyte by using the hydrogen evolved from the negative electrolyte is designed, fabricated and tested. The effects of the flow field, hydrogen concentration and H2/N2 mixture gas flow rate on the performance of the hydrogen-ferric ion rebalance cell have been investigated. Results show that: i) an interdigitated flow field based rebalance cell delivers higher limiting current densities than serpentine flow field based one does; ii) the hydrogen utilization can approach 100% at low hydrogen concentrations (≤5%); iii) the apparent exchange current density of hydrogen oxidation reaction in the rebalance cell is proportional to the square root of the hydrogen concentration at the hydrogen concentration from 1.3% to 50%; iv) a continuous rebalance process is demonstrated at the current density of 60 mA cm-2 and hydrogen concentration of 2.5%. Moreover, the cost analysis shows that the rebalance cell is just approximately 1% of an ICRFB system cost.

  14. Concentration of ions Co(II), Ni(II) at the Tokem-250 carboxylic cation exchange for catalysts development

    Science.gov (United States)

    Zharkova, Valentina; Bobkova, Ludmila; Brichkov, Anton; Kozik, Vladimir

    2017-11-01

    Sorption and catalytic properties of the cation exchanger are investigated. It was found that the Tokem-250 has a wide operating range of pH. The value of the effective ionization constant of the functional groups of the cation exchanger (pKa) is 6.59. The Tokem-250 cation exchanger exhibits selectivity to Ni2+ ions to Co2+ (D˜103). This is probably due to the stability of ion-exchange complexes detected by the method of diffuse reflectance electron spectroscopy (ESDD). According to these data, for Co2+ ions, in contrast to Ni2+, tetragonal distortion of octahedral coordination is characteristic, which has a positive effect on the stability of complexes with Co2+. To obtain spherical catalysts on the basis of Tokem-250, cobalt-containing samples of cation exchanger were used. The developed spherical materials have catalytic activity in the reactions of deep and partial oxidation of n-heptane.

  15. The dynamic ocean biological pump: Insights from a global compilation of particulate organic carbon, CaCO3, and opal concentration profiles from the mesopelagic

    Science.gov (United States)

    Lam, Phoebe J.; Doney, Scott C.; Bishop, James K. B.

    2011-09-01

    We have compiled a global data set of 62 open ocean profiles of particulate organic carbon (POC), CaCO3, and opal concentrations collected by large volume in situ filtration in the upper 1000 m over the last 30 years. We define concentration-based metrics for the strength (POC concentration at depth) and efficiency (attenuation of POC with depth in the mesopelagic) of the biological pump. We show that the strength and efficiency of the biological pump are dynamic and are characterized by a regime of constant and high transfer efficiency at low to moderate surface POC and a bloom regime where the height of the bloom is characterized by a weak deep biological pump and low transfer efficiency. The variability in POC attenuation length scale manifests in a clear decoupling between the strength of the shallow biological pump (e.g., POC at the export depth) and the strength of the deep biological pump (POC at 500 m). We suggest that the paradigm of diatom-driven export production is driven by a too restrictive perspective on upper mesopelagic dynamics. Indeed, our full mesopelagic analysis suggests that large, blooming diatoms have low transfer efficiency and thus may not export substantially to depth; rather, our analysis suggests that ecosystems characterized by smaller cells and moderately high %CaCO3 have a high mesopelagic transfer efficiency and can have higher POC concentrations in the deep mesopelagic even with relatively low surface or near-surface POC. This has negative implications for the carbon sequestration prospects of deliberate iron fertilization.

  16. A Liquid Inorganic Electrolyte Showing an Unusually High Lithium Ion Transference Number: A Concentrated Solution of LiAlCl4 in Sulfur Dioxide

    Directory of Open Access Journals (Sweden)

    Martin Winter

    2013-08-01

    Full Text Available We report on studies of an inorganic electrolyte: LiAlCl4 in liquid sulfur dioxide. Concentrated solutions show a very high conductivity when compared with typical electrolytes for lithium ion batteries that are based on organic solvents. Our investigations include conductivity measurements and measurements of transference numbers via nuclear magnetic resonance (NMR and by a classical direct method, Hittorf’s method. For the use of Hittorf’s method, it is necessary to measure the concentration of the electrolyte in a selected cell compartment before and after electrochemical polarization very precisely. This task was finally performed by potentiometric titration after hydrolysis of the salt. The Haven ratio was determined to estimate the association behavior of this very concentrated electrolyte solution. The measured unusually high transference number of the lithium cation of the studied most concentrated solution, a molten solvate LiAlCl4 × 1.6SO2, makes this electrolyte a promising alternative for lithium ion cells with high power ability.

  17. Proton concentrations can be a major contributor to the modification of osteoclast and osteoblast differentiation, working independently of extracellular bicarbonate ions.

    Science.gov (United States)

    Kato, Kohtaro; Matsushita, Misao

    2014-01-01

    We established a system to separately analyze the role of protons and bicarbonate ions in vitro in which the pH of the medium was controlled by HEPES at various concentrations of sodium bicarbonate (NaHCO3) in the absence of carbon dioxide (CO2). Using this system, we demonstrated that acidosis promoted osteoclast formation independently of extracellular NaHCO3 in a short-term culture. Protons and bicarbonate ions acted on osteoclast differentiation with opposite effects, the former positively and the latter negatively. The HEPES-based system maintained pH in the absence of extracellular NaHCO3 without CO2. Therefore, we could demonstrate that osteoblast differentiation was promoted at higher pH in a long-term culture system without NaHCO3 in which ALP activity and nodule mineralization were enhanced. This finding indicates that protons negatively control osteoblast differentiation independently of extracellular bicarbonate ions. However, the difference in the concentration of NaHCO3 did not have any influence on nodule mineralization. The opposite effects of protons, the promotion of osteoclast formation and the inhibition of osteoblast differentiation, were suppressed in the presence of 5 mM N-acetyl cysteine, a reagent activating the scavenging of reactive oxygen species (ROS), implying that ROS act on both systems, the promotion of large osteoclast formation and the deterioration of osteoblast formation under acidosis.

  18. A neuronal lactate uptake inhibitor slows recovery of extracellular ion concentration changes in the hippocampal CA3 region by affecting energy metabolism.

    Science.gov (United States)

    Angamo, Eskedar Ayele; Rösner, Joerg; Liotta, Agustin; Kovács, Richard; Heinemann, Uwe

    2016-11-01

    Astrocyte-derived lactate supports pathologically enhanced neuronal metabolism, but its role under physiological conditions is still a matter of debate. Here, we determined the contribution of astrocytic neuronal lactate shuttle for maintenance of ion homeostasis and energy metabolism. We tested for the effects of α-cyano-4-hydroxycinnamic acid (4-CIN), which could interfere with energy metabolism by blocking monocarboxylate-transporter 2 (MCT2)-mediated neuronal lactate uptake, on evoked potentials, stimulus-induced changes in K + , Na + , Ca 2+ , and oxygen concentrations as well as on changes in flavin adenine dinucleotide (FAD) autofluorescence in the hippocampal area CA3. MCT2 blockade by 4-CIN reduced synaptically evoked but not antidromic population spikes. This effect was dependent on the activation of K ATP channels indicating reduced neuronal ATP synthesis. By contrast, lactate receptor activation by 3,5-dihydroxybenzoic acid (3,5-DHBA) resulted in increased antidromic and orthodromic population spikes suggesting that 4-CIN effects are not mediated by lactate accumulation and subsequent activation of lactate receptors. Recovery kinetics of all ion transients were prolonged and baseline K + concentration became elevated by blockade of lactate uptake. Lactate contributed to oxidative metabolism as both baseline respiration and stimulus-induced changes in Po 2 were decreased, while FAD fluorescence increased likely due to a reduced conversion of FAD into FADH 2 These data suggest that lactate shuttle contributes to regulation of ion homeostatsis and synaptic signaling even in the presence of ample glucose. Copyright © 2016 the American Physiological Society.

  19. Accelerator mass spectrometry analysis of 14C-oxaliplatin concentrations in biological samples and 14C contents in biological samples and antineoplastic agents

    Science.gov (United States)

    Toyoguchi, Teiko; Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi; Kato, Kazuhiro; Tokanai, Fuyuki

    2015-10-01

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the 14C concentration in 14C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) - AMS system. The calibration curves of 14C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a 14C content of water in three vacuum blood collection tubes and a syringe were measured. 14C was not detected from water in these devices. The mean 14C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of 14C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, 14C contents of the antineoplastic agents were quantitated. 14C contents were different among 10 antineoplastic agents; 14C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  20. Accelerator mass spectrometry analysis of "1"4C-oxaliplatin concentrations in biological samples and "1"4C contents in biological samples and antineoplastic agents

    International Nuclear Information System (INIS)

    Toyoguchi, Teiko; Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi; Kato, Kazuhiro; Tokanai, Fuyuki

    2015-01-01

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the "1"4C concentration in "1"4C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) – AMS system. The calibration curves of "1"4C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a "1"4C content of water in three vacuum blood collection tubes and a syringe were measured. "1"4C was not detected from water in these devices. The mean "1"4C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of "1"4C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, "1"4C contents of the antineoplastic agents were quantitated. "1"4C contents were different among 10 antineoplastic agents; "1"4C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  1. Accelerator mass spectrometry analysis of {sup 14}C-oxaliplatin concentrations in biological samples and {sup 14}C contents in biological samples and antineoplastic agents

    Energy Technology Data Exchange (ETDEWEB)

    Toyoguchi, Teiko, E-mail: tteiko@med.id.yamagata-u.ac.jp [Department of Pharmacy, Yamagata University Hospital, 2-2-2 Iida-Nishi, Yamagata-shi, Yamagata 990-9585 (Japan); Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi [Department of Pharmacy, Yamagata University Hospital, 2-2-2 Iida-Nishi, Yamagata-shi, Yamagata 990-9585 (Japan); Kato, Kazuhiro; Tokanai, Fuyuki [Department of Physics, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata-shi, Yamagata 990-8560 (Japan)

    2015-10-15

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the {sup 14}C concentration in {sup 14}C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) – AMS system. The calibration curves of {sup 14}C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a {sup 14}C content of water in three vacuum blood collection tubes and a syringe were measured. {sup 14}C was not detected from water in these devices. The mean {sup 14}C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of {sup 14}C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, {sup 14}C contents of the antineoplastic agents were quantitated. {sup 14}C contents were different among 10 antineoplastic agents; {sup 14}C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  2. Comparison of metal toxic impacts between aquatic and terrestrial organisms: is the free ion concentration a sufficient descriptor?

    DEFF Research Database (Denmark)

    Owsianiak, Mikolaj; Rosenbaum, Ralph K.; Larsen, Henrik Fred

    2011-01-01

    Characterization of metal toxic impacts in comparative risk assessment and life cycle impact assessment (LCIA) should take into account metal speciation and interactions with soil/water organic constituents, because these mechanisms control metal bioavailability and may influence their toxic...... that the free metal ion is an appropriate “general”descriptor of metal toxicity. Results for 128 laboratory tests on Daphnia magna exposed to copper ions (Cu2+) in water show that variation of several orders of magnitude are observed between the toxicity tests. These variations may be a result of the inability...... of magnitude difference occur for the extreme case of barley (Hordeum vulgare). Given the scarcity of terrestrial effect data compared to aquatic data, reliable and transparent, mechanistic-based predictions of terrestrial toxic impacts from aquatic effect data would be an important step ahead in the context...

  3. Biological and medical research with accelerated heavy ions at the Bevalac, 1974--1977. [Planning for use for radiotherapy and as radiation source for diagnostic radiography

    Energy Technology Data Exchange (ETDEWEB)

    Elam, S. (ed.)

    1977-04-01

    The Bevalac, a versatile high-energy heavy-ion accelerator complex, has been in operation for less than two years. A major purpose for which the Bevalac was constructed was to explore the possibility of heavy-ion teams for therapy for certain forms of cancer. Significant progress has been made in this direction. The National Cancer Institute has recognized the advantages that these and other accelerated particles offer, and heavy ions have been included in a long-term plan for particle therapy that will assess by means of controlled therapeutic tests the value of various modalities. Since accelerated heavy ions became available, the possibility of other contributions, not planned, became apparent. We are developig a new diagnostic method known as heavy-ion radiography that has greatly increased sensitivity for soft-tissue detail and that may become a powerful tool for localizing early tumors and metastases. We have discovered that radioactive beams are formed from fragmentation of stable deflected beams. Use of these autoradioactive beams is just beginning; however, we know that these beams will be helpful in localizing the region in the body where therapy is being delivered. In addition, it has been demonstrated that instant implantation of the radioactive beam allows direct measurements of blood perfusion rates in inaccessible parts of the body, and such a technique may become a new tool for the study of fast hot atom reactions in biochemistry, tracer biology and nuclear medicine. The Bevalac will also be useful for the continuation of previously developed methods for the control of acromegaly, Cushing's disease and, on a research basis, advanced diabetes mellitus with vascular disease. The ability to make small bloodless lesions in the brain and elsewhere with heavy-ion beams has great potential for nervous-system studies and perhaps later for radioneurosurgery.

  4. Handheld Device Adapted to Smartphone Cameras for the Measurement of Sodium Ion Concentrations at Saliva-Relevant Levels via Fluorescence

    OpenAIRE

    Lipowicz, Michelle; Garcia, Antonio

    2015-01-01

    The use of saliva sampling as a minimally-invasive means for drug testing and monitoring physiology is a subject of great interest to researchers and clinicians. This study describes a new optical method based on non-axially symmetric focusing of light using an oblate spheroid sample chamber. The device is simple, lightweight, low cost and is easily attached to several different brands/models of smartphones (Apple, Samsung, HTC and Nokia) for the measurement of sodium ion levels at physiologi...

  5. Hydronium-dominated ion transport in carbon-dioxide-saturated electrolytes at low salt concentrations in nanochannels

    DEFF Research Database (Denmark)

    Lund Jensen, Kristian; Kristensen, Jesper Toft; Crumrine, Andrew Michael

    2011-01-01

    the nanochannel conductance at low salt concentrations and identify a conductance minimum before saturation at a value independent of salt concentration in the dilute limit. Via the Poisson-Boltzmann equation, our model self-consistently couples chemical-equilibrium dissociation models of the silica wall...

  6. Spectral variations and energy transfer processes on both Er 3+ ion concentration and excitation densities in Yb 3+-Er 3+ codoped LaF3 materials

    International Nuclear Information System (INIS)

    Zhang Jisen; Qin Weiping; Zhao Dan; Degejihu; Zhang Jishuang; Wang Yan; Cao Chunyan

    2007-01-01

    In comparison with the up-conversion spectra of Yb 3+ -Er 3+ codopded systems reported previously, the interesting intensity changes of up-conversion luminescence between the violet, the blue, the green and the red on the both Er 3+ ion concentration and excitation density with 978 nm laser diodes as an excitation source were observed in Yb 3+ -Er 3+ codopded LaF 3 powders. In order to clarify the change mechanisms, the up-conversion spectra of LaF 3 : 10 mol% Yb 3+ , 0.5 mol% Er 3+ and LaF 3 : 10 mol% Yb 3+ , 1 mol% Er 3+ were investigated and the results indicated that the cross-relaxation processes between Er 3+ ions and the thermal population of the 2 H 11/2 level play significant roles

  7. High concentrations of Na+ and Cl- ions in soil solution have simultaneous detrimental effects on growth of faba bean under salinity stress.

    Science.gov (United States)

    Tavakkoli, Ehsan; Rengasamy, Pichu; McDonald, Glenn K

    2010-10-01

    Despite the fact that most plants accumulate both sodium (Na(+)) and chloride (Cl(-)) ions to high concentration in their shoot tissues when grown in saline soils, most research on salt tolerance in annual plants has focused on the toxic effects of Na(+) accumulation. There have also been some recent concerns about the ability of hydroponic systems to predict the responses of plants to salinity in soil. To address these two issues, an experiment was conducted to compare the responses to Na(+) and to Cl(-) separately in comparison with the response to NaCl in a soil-based system using two varieties of faba bean (Vicia faba), that differed in salinity tolerance. The variety Nura is a salt-sensitive variety that accumulates Na(+) and Cl(-) to high concentrations while the line 1487/7 is salt tolerant which accumulates lower concentrations of Na(+) and Cl(-). Soils were prepared which were treated with Na(+) or Cl(-) by using a combination of different Na(+) salts and Cl(-) salts, respectively, or with NaCl. While this method produced Na(+)-dominant and Cl(-)-dominant soils, it unavoidably led to changes in the availability of other anions and cations, but tissue analysis of the plants did not indicate any nutritional deficiencies or toxicities other than those targeted by the salt treatments. The growth, water use, ionic composition, photosynthesis, and chlorophyll fluorescence were measured. Both high Na(+) and high Cl(-) reduced growth of faba bean but plants were more sensitive to Cl(-) than to Na(+). The reductions in growth and photosynthesis were greater under NaCl stress and the effect was mainly additive. An important difference to previous hydroponic studies was that increasing the concentrations of NaCl in the soil increased the concentration of Cl(-) more than the concentration of Na(+). The data showed that salinity caused by high concentrations of NaCl can reduce growth by the accumulation of high concentrations of both Na(+) and Cl(-) simultaneously, but

  8. In situ Raman spectroscopic studies on concentration change of electrolyte salt in a lithium ion model battery with closely faced graphite composite and LiCoO2 composite electrodes by using an ultrafine microprobe

    International Nuclear Information System (INIS)

    Yamanaka, Toshiro; Nakagawa, Hiroe; Tsubouchi, Shigetaka; Domi, Yasuhiro; Doi, Takayuki; Abe, Takeshi; Ogumi, Zempachi

    2017-01-01

    The concentration of ions in the electrolyte solution in lithium ion batteries changes during operation, reflecting the resistance to ion migration and the positions of diffusion barriers. The change causes various negative effects on the performance of batteries. Thus, it is important to elucidate how the concentration changes during operation. In this work, the concentration change of ions in the electrolyte solution in deep narrow spaces in a realistic battery was studied by in situ ultrafine microprobe Raman spectroscopy. Graphite composite and LiCoO 2 composite electrodes, which are the most commonly used electrodes in practical batteries, were placed facing each other and their distance was set to 80 μm, which is close to the distance between electrodes in practical batteries. After repeated charge/discharge cycles, the concentration of ions increased and decreased greatly during charging and discharging, respectively. The maximum concentration was more than three-times higher than the minimum concentration. The rate of changes in concentration increased almost linearly with increase in current density. The results have important implications about concentration changes of ions occurring in practical batteries.

  9. Development of an Analytical Protocol for Determination of Cyanide in Human Biological Samples Based on Application of Ion Chromatography with Pulsed Amperometric Detection

    Directory of Open Access Journals (Sweden)

    Ewa Jaszczak

    2017-01-01

    Full Text Available A simple and accurate ion chromatography (IC method with pulsed amperometric detection (PAD was proposed for the determination of cyanide ion in urine, sweat, and saliva samples. The sample pretreatment relies on alkaline digestion and application of Dionex OnGuard II H cartridge. Under the optimized conditions, the method showed good linearity in the range of 1–100 μg/L for urine, 5–100 μg/L for saliva, and 3–100 μg/L for sweat samples with determination coefficients (R>0.992. Low detection limits (LODs in the range of 1.8 μg/L, 5.1 μg/L, and 5.8 μg/L for urine, saliva, and sweat samples, respectively, and good repeatability (CV < 3%, n=3 were obtained. The proposed method has been successfully applied to the analysis of human biological samples.

  10. Development of an Analytical Protocol for Determination of Cyanide in Human Biological Samples Based on Application of Ion Chromatography with Pulsed Amperometric Detection.

    Science.gov (United States)

    Jaszczak, Ewa; Ruman, Marek; Narkowicz, Sylwia; Namieśnik, Jacek; Polkowska, Żaneta

    2017-01-01

    A simple and accurate ion chromatography (IC) method with pulsed amperometric detection (PAD) was proposed for the determination of cyanide ion in urine, sweat, and saliva samples. The sample pretreatment relies on alkaline digestion and application of Dionex OnGuard II H cartridge. Under the optimized conditions, the method showed good linearity in the range of 1-100  μ g/L for urine, 5-100  μ g/L for saliva, and 3-100  μ g/L for sweat samples with determination coefficients ( R ) > 0.992. Low detection limits (LODs) in the range of 1.8  μ g/L, 5.1  μ g/L, and 5.8  μ g/L for urine, saliva, and sweat samples, respectively, and good repeatability (CV < 3%, n = 3) were obtained. The proposed method has been successfully applied to the analysis of human biological samples.

  11. X-ray fluorescence analysis (XRF) and secondary ion mass spectrometry (SIMS) for analysis of iodine concentration in vitro in benign and malignant thyroid tissue

    International Nuclear Information System (INIS)

    Hansson, Marie; Berg, Gertrud; Ericsson, Lars; Grunditz, Torsten; Isaksson, Mats; Jansson, Svante; Nystrom, Ernst; Sodervall, Ulf

    2005-01-01

    Full text: The thyroid ability to store and concentrate iodine is of importance for radioiodine therapy in thyroid cancer. It is known that a normal thyroid contains 2-20 mg iodine while the information regarding malignant thyroid tissue is scarce. The purpose of this study was to investigate the iodine concentration in benign compared to malignant tissue. Methods: Thyroid tissue samples from healthy patients and from patients with papillary cancer were collected and frozen in connection with surgery. For the thyroid cancer patients, tissue was taken from both benign and malignant tissue. The iodine concentration was analysed with an XRF system consisting of a 241-Am source and an HPGe detector. When irradiating iodine containing tissue, characteristic X-rays are emitted. That radiation is detected with the strength of the detected signal being proportional to the amount of iodine in the sample. SIMS was used on glutaraldehyde fixed tissue as a histological tool for quantification and localization of iodine by sputtering and analysis of secondary ions. Results: The iodine concentration in benign tissue is considerably higher than in malignant samples. XRF measurements showed a medium iodine concentration in healthy thyroid tissue of 0.5 mg/mL. For the cancer patients, the iodine concentration was 0.3 mg/mL in benign tissue while no iodine could be detected in the malignant samples. These findings were consistent with the results from the SIMS investigation that gave a 100 times lower iodine concentration in malignant than in benign tissue. SIMS also showed that the iodine in benign tissue was predominantly located in the follicle lumen, while in the cancer cells low iodine concentration was found intra cellular as well as in the lumen. Conclusion: Iodine concentration in tissue from papillary cancer can be 100 times lower than in normal thyroid tissue. This is in accordance with the empirical knowledge that thyroid cancer should need about 100 times higher activity

  12. Influences of hydrological regime on heavy metal and salt ion concentrations in intertidal sediment from Chongming Dongtan, Changjiang River estuary, China

    Science.gov (United States)

    Zhao, Jiale; Gao, Xiaojiang; Yang, Jin

    2017-11-01

    The tidal flat along the Changjiang (Yangtze) River estuary has long been reclaimed for the agricultural purposes, with the prevailing hydrological conditions during such pedogenic transformations being of great importance to their successful development. In this study, samples of surface sediment from Chongming Dongtan, situated at the mouth of the Changjiang River estuary, were collected and analyzed in order to understand how hydrological management can influence the concentrations of heavy metals and salt ions in pore water, and chemical fractionation of heavy metals during the reclamation process. We performed a series of experiments that simulated three different hydrological regimes: permanent flooding (R1), alternative five-day periods of wetting and drying (R2), continuous field capacity (R3). Our results exhibited good Pearson correlations coefficients between heavy metals and salt ions in the pore water for both R1 and R2. In particular, the concentrations of salt ions in the pore water decreased in all three regimes, but showed the biggest decline in R2. With this R2 experiment, the periodic concentration patterns in the pore water varied for Fe and Mn, but not for Cr, Cu, Pb and Zn. Neither the fractionation of Ni nor the residual fractions of any metals changed significantly in any regime. In R1, the reducible fractions of heavy metals (Cr, Cu, Zn and Pb) in the sediment decreased, while the acid extractable fractions increased. In R2, the acid extractable and the reducible fractions of Cr, Cu, Zn and Pb both decreased, as did the oxidizable fraction of Cu. These data suggest that an alternating hydrological regime can reduce both salinity and the availability of heavy metals in sediments.

  13. The relative biological effectiveness for carbon and oxygen ion beams using the raster-scanning technique in hepatocellular carcinoma cell lines.

    Directory of Open Access Journals (Sweden)

    Daniel Habermehl

    Full Text Available BACKGROUND: Aim of this study was to evaluate the relative biological effectiveness (RBE of carbon (12C and oxygen ion (16O-irradiation applied in the raster-scanning technique at the Heidelberg Ion beam Therapy center (HIT based on clonogenic survival in hepatocellular carcinoma cell lines compared to photon irradiation. METHODS: Four human HCC lines Hep3B, PLC, HepG2 and HUH7 were irradiated with photons, 12C and 16O using a customized experimental setting at HIT for in-vitro trials. Cells were irradiated with increasing physical photon single doses of 0, 2, 4 and 6 Gy and heavy ion-single doses of 0, 0.125, 0.5, 1, 2, 3 Gy (12C and 16O. SOBP-penetration depth and extension was 35 mm +/-4 mm and 36 mm +/-5 mm for carbon ions and oxygen ions respectively. Mean energy level and mean linear energy transfer (LET were 130 MeV/u and 112 keV/um for 12C, and 154 MeV/u and 146 keV/um for 16O. Clonogenic survival was computated and relative biological effectiveness (RBE values were defined. RESULTS: For all cell lines and both particle modalities α- and β-values were determined. As expected, α-values were significantly higher for 12C and 16O than for photons, reflecting a steeper decline of the initial slope of the survival curves for high-LET beams. RBE-values were in the range of 2.1-3.3 and 1.9-3.1 for 12C and 16O, respectively. CONCLUSION: Both irradiation with 12C and 16O using the raster-scanning technique leads to an enhanced RBE in HCC cell lines. No relevant differences between achieved RBE-values for 12C and 16O were found. Results of this work will further influence biological-adapted treatment planning for HCC patients that will undergo particle therapy with 12C or 16O.

  14. Decreased Sensitivity to Changes in the Concentration of Metal Ions as the Basis for the Hyperactivity of DtxR(E175K)

    Energy Technology Data Exchange (ETDEWEB)

    D’Aquino, J. Alejandro; Denninger, Andrew R.; Moulin, Aaron G.; D’Aquino, Katharine E.; Ringe, Dagmar; (Harvard-Med); (Brandeis)

    2010-01-12

    The metal-ion-activated diphtheria toxin repressor (DtxR) is responsible for the regulation of virulence and other genes in Corynebacterium diphtheriae. A single point mutation in DtxR, DtxR(E175K), causes this mutant repressor to have a hyperactive phenotype. Mice infected with Mycobacterium tuberculosis transformed with plasmids carrying this mutant gene show reduced signs of the tuberculosis infection. Corynebacterial DtxR is able to complement mycobacterial IdeR and vice versa. To date, an explanation for the hyperactivity of DtxR(E175K) has remained elusive. In an attempt to address this issue, we have solved the first crystal structure of DtxR(E175K) and characterized this mutant using circular dichroism, isothermal titration calorimetry, and other biochemical techniques. The results show that although DtxR(E175K) and the wild type have similar secondary structures, DtxR(E175K) gains additional thermostability upon activation with metal ions, which may lead to this mutant requiring a lower concentration of metal ions to reach the same levels of thermostability as the wild-type protein. The E175K mutation causes binding site 1 to retain metal ion bound at all times, which can only be removed by incubation with an ion chelator. The crystal structure of DtxR(E175K) shows an empty binding site 2 without evidence of oxidation of Cys102. The association constant for this low-affinity binding site of DtxR(E175K) obtained from calorimetric titration with Ni(II) is K{sub a} = 7.6 {+-} 0.5 x 10{sup 4}, which is very similar to the reported value for the wild-type repressor, K{sub a} = 6.3 x 10{sup 4}. Both the wild type and DtxR(E175K) require the same amount of metal ion to produce a shift in the electrophoretic mobility shift assay, but unlike the wild type, DtxR(E175K) binding to its cognate DNA [tox promoter-operator (toxPO)] does not require metal-ion supplementation in the running buffer. In the timescale of these experiments, the Mn(II)-DtxR(E175K)-toxPO complex

  15. The DC Electrical Resistivity Curves of Bismuth-2212 Ceramic Superconductors: Evaluation of the Hole-Carrier Concentrations per-Cu Ion

    Directory of Open Access Journals (Sweden)

    nurmalita .

    2016-04-01

    Full Text Available In this study the samples of Bismuth ceramic superconductors were synthesized by the melt textured growth methods from a 2212 stoichiometric composition in order to obtain a large amount of pure Bi-2212. The effects of Pb substitution on the properties of Bi-based Bi2−xPbxSr2CaCu2Oy superconductor with x = 0, 0.2, and 0.4 were investigated by means of DC electrical resistivity measurements. It has been found that the hole-carrier concentrations per-Cu ion of the samples change independently of Pb content.

  16. Biological removal of sulfur from coal flotation concentrate by culture isolated from coal washery plant tailing dump

    Energy Technology Data Exchange (ETDEWEB)

    Jorjani, E. [Azad University, Tehran (Iran). Mining Engineering Dept.

    2005-10-15

    A combination of flotation and microbial leaching processes was used to achieve acceptable level of sulfur and ash in Tabas coal sample of Iran. Representative sample of the minus 500 micron size fraction was subjected to flotation separation for the removal of ash and sulfur. The final concentrate with recovery, combustion value and sulfur content of 86.03, 86.45 and 1.35% respectively was achieved at pH 8 and following reagent dosage and operating conditions: collector: diesel oil (1200 g/ton), frother: MIBC (5%) + pine oil (95%) with concentration of 120 (g/ton), depressant: sodium silicate (1000 g/ton), particle size: {lt} 500 {mu} m and pulp density: 7%. Because of fine distribution of sulfur on Tabas coal macerals and lithotypes, high percentage of total sulfur (79.9%) is distributed in flotation concentrate and only 20.1% is yielded in the tails. So microbial leaching using a species isolated from coal washery plant tailing dump was used in batch system to remove sulfur from flotation concentrate. The conditions were optimized for the maximum removal of sulfur. These conditions were found to be pH of 2, particle size less than 0.18 mm; pulp density: 8%, temperature: 30 {sup o}C, shaking rate: 150 rpm conditions. Total sulfur and ash content was reduced by bioleaching from 13.55 and 1.35 in flotation concentrate to 9.47 and 0.55 in the final leached concentrate, a reduction of 35 and 61.9% respectively. Sterilization of coal adversely affects the sulfur reduction. The results suggest that the isolated culture is sufficiently effective for depyritization of Tabas coal flotation concentrate in stirred system.

  17. Adverse reaction to metal debris in a consecutive series of DUROM™ hip resurfacing: pseudotumour incidence and metal ion concentration.

    Science.gov (United States)

    Hartmann, Albrecht; Kieback, Jan-Dirk; Lützner, Jörg; Günther, Klaus-Peter; Goronzy, Jens

    2017-07-25

    The aim of this study was to evaluate the incidence of adverse reactions to metal debris (ARMD) in a consecutive series of DUROM™ Hip Resurfacing Arthroplasty (HRA) at mid-term follow-up. Between October 2003 and March 2007 a total of 134 consecutive DUROM™ HRA in 121 patients were performed at our institution. Follow-up could be obtained in 101 unrevised patients (83%) at a mean time of 8.51 ± 0.97 years postoperatively and included patient-related outcome measurement, plain radiographs, MARS-MRI as well as whole blood metal ion assessment. 17 (16.5%) out of 103 hips revealed pseudotumour occurrence in MRI investigation, 1 (10.6%) with a diameter of ≥2 cm. Higher incidence of pseudotumours was found patients with femoral component size 7 μg/l. In contrast to cobalt determination, only elevated chromium values showed a positive association with pseudotumour occurrence and size. A significant proportion of patients developed pseudotumours and metal ion elevation in a consecutive cohort of DUROM™ HRA after mid-term follow-up. The incidence, however, seems not to differ from results of other well performing resurfacing brands; clinical relevance of our findings is unclear. Regarding potential local as well as systemic effects of metal particle release, close follow-up of patients is essential, even with clinically well-performing implants.

  18. Direct evaluation of radiobiological parameters from clinical data in the case of ion beam therapy: an alternative approach to the relative biological effectiveness

    International Nuclear Information System (INIS)

    Cometto, A; Russo, G; Giordanengo, S; Marchetto, F; Cirio, R; Attili, A; Bourhaleb, F; Milian, F M

    2014-01-01

    The relative biological effectiveness (RBE) concept is commonly used in treatment planning for ion beam therapy. Whether models based on in vitro/in vivo RBE data can be used to predict human response to treatments is an open issue. In this work an alternative method, based on an effective radiobiological parameterization directly derived from clinical data, is presented. The method has been applied to the analysis of prostate cancer trials with protons and carbon ions. Prostate cancer trials with proton and carbon ion beams reporting 5 year-local control (LC5) and grade 2 (G2) or higher genitourinary toxicity rates (TOX) were selected from literature to test the method. Treatment simulations were performed on a representative subset of patients to produce dose and linear energy transfer distribution, which were used as explicative physical variables for the radiobiological modelling. Two models were taken into consideration: the microdosimetric kinetic model (MKM) and a linear model (LM). The radiobiological parameters of the LM and MKM were obtained by coupling them with the tumor control probability and normal tissue complication probability models to fit the LC5 and TOX data through likelihood maximization. The model ranking was based on the Akaike information criterion. Results showed large confidence intervals due to the limited variety of available treatment schedules. RBE values, such as RBE = 1.1 for protons in the treated volume, were derived as a by-product of the method, showing a consistency with current approaches. Carbon ion RBE values were also derived, showing lower values than those assumed for the original treatment planning in the target region, whereas higher values were found in the bladder. Most importantly, this work shows the possibility to infer the radiobiological parametrization for proton and carbon ion treatment directly from clinical data. (paper)

  19. [Concentration of calcium ions in the saliva and the value of the pH of the saliva in female and male smokers].

    Science.gov (United States)

    Nakonieczna-Rudnicka, Marta; Bachanek, Teresa; Rogowska, Wanda

    2009-01-01

    Dental decay is a pathological process of extrasomatic origin which leads to demineralization and proteolytic degradation of hard surfaces of a tooth susceptible to this disease. Saliva composition, including calcium ion concentration and its pH value, is of importance in the development of the carious process. Tobacco smoke contains toxic compounds which negatively influence oral health. The aim of the study was evaluation of the selected saliva components: protein concentration, Ca2+ concentration, pH value both in male and female smokers. The investigated group included 65 patients reporting for the treatment to the Department of Conservative Dentistry of Medical University in Lublin. In the investigated group male smokers constituted 15.38%, female smokers--20.00%, male nicotine abstinents 21.54% and female nicotine abstinent 43.08%. The study included both survey examinations of patients and biochemical examinations of the saliva. Mixed, non-stimulated saliva was used as a material for biochemical examinations. Ca2+ concentration and pH of the saliva were assayed with the use of Rapidlab 348 analyzer. Protein in the saliva was assayed with calorimetric method according to Lowry. Saliva was collected from smokers 10-120 minutes after smoking of several cigarettes. It was stated that Ca2+ and protein concentration as well as pH of the saliva were not correlated with sex and cigarette smoking or non-smoking.

  20. Biological variables and health status affecting inorganic element concentrations in harbour porpoises (Phocoena phocoena) from Portugal (western Iberian Peninsula)

    International Nuclear Information System (INIS)

    Ferreira, Marisa; Monteiro, Silvia S.; Torres, Jordi; Oliveira, Isabel; Sequeira, Marina; López, Alfredo

    2016-01-01

    The coastal preferences of harbour porpoise (Phocoena phocoena) intensify their exposure to human activities. The harbour porpoise Iberian population is presently very small and information about the threats it endures is vital for the conservation efforts that are being implemented to avoid local extinction. The present study explored the possible relation between the accumulation of trace elements by porpoises and their sex, body length, nutritional state, presence of parasites and gross pathologies. The concentrations of arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), zinc (Zn) and selenium (Se) were evaluated in 42 porpoises stranded in Portugal between 2005 and 2013. Considering European waters, porpoises stranded in Portugal present the highest Hg concentrations and the lowest Cd concentrations, which may reflect dietary preferences and the geographic availability of these pollutants. While no effect of sex on trace element concentrations was detected, there was a positive relationship between porpoise body length and the concentration of Cd, Hg and Pb. Animals in worse nutritional condition showed higher levels of Zn. Harbour porpoises with high parasite burdens showed lower levels of Zn and As in all analysed tissues and also lower levels of renal Ni, while those showing gross pathologies presented higher Zn and Hg levels. This is the first data on the relationship between trace elements and health-related variables in porpoises from southern European Atlantic waters, providing valuable baseline information about the contamination status of this vulnerable population. - Highlights: • High levels of mercury in harbour porpoises from Portugal. • Evidence of bioaccumulation of non-essential trace elements. • Presence of parasites influenced some essential trace elements. • Evidence of nutritional state effect on Zn levels. • Presence of gross pathologies influenced Zn and Hg levels. - The small harbour

  1. Effect of pH and complementary ion concentration on nitrate removal using puroliteA400 Resin impregnated Cu in batch system

    Science.gov (United States)

    Turmuzi, M.; Tarigan, Z. N.; Nadapdap, L.; Batubara, F.

    2018-02-01

    The total nitrogen content in water bodies should be below 50 mg NO3 -/L (11.3 mgN/l) World Health Organization (WHO) 2006. The content of nitrogen exceeding the quality standard threshold will cause damage to the aquatic ecosystem and be carcinogenic to humans. The Purolite A-400 resin will be modified with Cu metal by batch method to see the adsorption allowance of nitrate in synthetic liquid waste with nitrate concentration of 50 mg/l. This study will evaluate the effect of pH and complementary ions on the adsorption process. From the result of the research, the second order pseudo model is the most suitable adsorption kinetics model. For the adsorption isotherms the most suitable model is the Freundlich adsorption isotherm model. The optimum pH conditions were at the range of 8.5. The addition of complementary ions sulfate and phosphate did not show any significant change, but sulfate is the most effective complementary ion with a content of 20 mg/l.

  2. Numerical simulation and experimental validation of the three-dimensional flow field and relative analyte concentration distribution in an atmospheric pressure ion source.

    Science.gov (United States)

    Poehler, Thorsten; Kunte, Robert; Hoenen, Herwart; Jeschke, Peter; Wissdorf, Walter; Brockmann, Klaus J; Benter, Thorsten

    2011-11-01

    In this study, the validation and analysis of steady state numerical simulations of the gas flows within a multi-purpose ion source (MPIS) are presented. The experimental results were obtained with particle image velocimetry (PIV) measurements in a non-scaled MPIS. Two-dimensional time-averaged velocity and turbulent kinetic energy distributions are presented for two dry gas volume flow rates. The numerical results of the validation simulations are in very good agreement with the experimental data. All significant flow features have been correctly predicted within the accuracy of the experiments. For technical reasons, the experiments were conducted at room temperature. Thus, numerical simulations of ionization conditions at two operating points of the MPIS are also presented. It is clearly shown that the dry gas volume flow rate has the most significant impact on the overall flow pattern within the APLI source; far less critical is the (larger) nebulization gas flow. In addition to the approximate solution of Reynolds-Averaged Navier-Stokes equations, a transport equation for the relative analyte concentration has been solved. The results yield information on the three-dimensional analyte distribution within the source. It becomes evident that for ion transport into the MS ion transfer capillary, electromagnetic forces are at least as important as fluid dynamic forces. However, only the fluid dynamics determines the three-dimensional distribution of analyte gas. Thus, local flow phenomena in close proximity to the spray shield are strongly impacting on the ionization efficiency.

  3. Photoluminescence and spectroscopic dependence of fluorophosphate glasses on samarium ions concentration and the induced defects by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Marzouk, M.A., E-mail: marzouk_nrc@yahoo.com [Glass Research Department, National Research Centre, 33 El Bohouth Street (former EL Tahrir), P.O. 12622, Dokki, Giza (Egypt); Hamdy, Y.M. [Spectroscopy Department, National Research Centre, 33 El Bohouth Street (former EL Tahrir), P.O. 12622, Dokki, Giza (Egypt); ElBatal, H.A. [Glass Research Department, National Research Centre, 33 El Bohouth Street (former EL Tahrir), P.O. 12622, Dokki, Giza (Egypt); Ezz ElDin, F.M. [National Institute for Radiation Research & Technology, Nasr City, Cairo (Egypt)

    2015-10-15

    Combined optical, FTIR and photoluminescence spectra of varying Sm{sup 3+} ions in NaF–AlF{sub 3}–phosphate glasses were investigated before and after successive gamma irradiation. Optical (UV–visible) absorption of the base undoped glass reveals UV absorption which becomes broadened and strong with progressive gamma irradiation. The UV absorption of the undoped glass is related to unavoidable trace iron impurity (Fe{sup 3+}) contaminated within the chemicals used for its preparation. Upon gamma irradiation, ferrous ions present in noticeable percent within the impurity due to the reducing nature of phosphate glass interact with positive holes during the irradiation process and are transformed to ferric ions through photochemical reactions and the additionally formed Fe{sup 3+} ions impart their characteristic strong absorption in the UV region. Sm{sup 3+} containing glasses show characteristic small peaks arranged into two regions from about 350 to 900 nm and from about 1000 to 1600 nm. Such absorption peaks are more distinct with the increase of Sm{sub 2}O{sub 3} content. Most of the limited number of absorption peaks are due to transitions from the {sup 6}H{sub 5/2} level to the various excited {sup 2s+1}L{sub J} levels. The majority of the transitions in the spectra are assumed to originate from induced electric dipole (ED) interactions with the selection rule ∆J≤6. The intense band {sup 6}P{sub 3/2}←{sup 6}H{sub 5/2} around 25,000 cm{sup −1} (~400 nm) is spin-allowed. The emission spectra of Sm{sup 2+} ions were recorded under the excitation wavelength of 402 nm for all prepared Sm{sub 2}O{sub 3}-containing glasses. The photoluminescence spectra show four emission lines, of which three consist of strong bands while the last line is a weak band. The wavelengths of the four luminescence peaks occur at about 560, 596, 642 and 702 nm and they are assigned to transitions from {sup 4}G{sub 5/2} to {sup 6}H{sub 5/2}, {sup 6}H{sub 7/2}, {sup 6}H{sub 9

  4. Concentration-elastic-stress instabilities in the distribution of ions and neutral particles in the insulator layer at the semiconductor surface

    International Nuclear Information System (INIS)

    Gol'dman, E. I.

    2006-01-01

    Mobile impurities in the form of ions and neutral associations are present in the insulator films that isolate the semiconductor from the metal electrode. If temperatures and the polarizing electric field are sufficiently high, impurities concentrate at the insulator-semiconductor interface where they exchange electrons with the semiconductor. It is shown that the pairwise interaction of particles via the field of elastic stresses caused by the concentration-related expansion of the insulator can give rise to an instability in the impurity distribution that is uniform over the contact. The stationary small-scale ordering of the particles over the contact of the insulator with the semiconductor arises in the solution of point defects, which is accompanied by annular flows of the particles

  5. Determination of human and Sprague-Dawley rat trimethylseleonium ion and total selenium urine concentrations from endogenous body selenium pool by neutron activation analysis

    International Nuclear Information System (INIS)

    Blotcky, A.J.; Claassen, J.P.; Rack, E.P.

    1992-01-01

    This study determined trimethylselenonium ion [TMSe,(CH 3 ) 3 Se + ] and total organic selenium cationic species urinary excretion values for healthy human subjects and Sprague-Dawley rats fed regular diets. The only source of TMSe was from the endogenous selenium body pool. Total selenium concentration in urine was determined by instrumental neutron activation analysis. TMSe and total selenium cationic species concentrations and percent of total selenium urine excretion were determined by chemical neutron activation analysis and coupled anion-cation exchange chromatography and anion-exchange chromatography, respectively. Within experimental error, mean values for TMSe and cationic species as percent selenium were comparable for both human subjects and Sprague-Dawley rats. This study suggested that TMSe excreated in urine by healthy human subjects and Sprague-Dawley rats fed a normal diet is not a minor but a general metabolite of selenium ingested in a normal diet. (author) 27 refs.; 1 fig.; 2 tabs

  6. Immobilization of α-amylase and amyloglucosidase onto ion-exchange resin beads and hydrolysis of natural starch at high concentration.

    Science.gov (United States)

    Gupta, Kapish; Jana, Asim Kumar; Kumar, Sandeep; Maiti, Mithu

    2013-11-01

    α-Amylase was immobilized on Dowex MAC-3 with 88 % yield and amyloglucosidase on Amberlite IRA-400 ion-exchange resin beads with 54 % yield by adsorption process. Immobilized enzymes were characterized to measure the kinetic parameters and optimal operational parameters. Optimum substrate concentration and temperature were higher for immobilized enzymes. The thermal stability of the enzymes enhanced after the immobilization. Immobilized enzymes were used in the hydrolysis of the natural starch at high concentration (35 % w/v). The time required for liquefaction of starch to 10 dextrose equivalent (DE) and saccharification of liquefied starch to 96 DE increased. Immobilized enzymes showed the potential for use in starch hydrolysis as done in industry.

  7. INTRACELLULAR ION CONCENTRATIONS IN BRANCHIAL EPITHELIAL CELLS OF BROWN TROUT (SALMO TRUTTA L.) DETERMINED BY X-RAY MICROANALYSIS

    Science.gov (United States)

    Morgan; Potts; Oates

    1994-09-01

    The intracellular concentrations of sodium, chloride, phosphorus and potassium under normal conditions in pavement epithelial (PE) cells of brown trout (Salmo trutta) gill were 66, 51, 87 and 88 mmol l-1 respectively. The concentrations of these elements under identical conditions in mitochondria-rich (MR) cells were not significantly different, except for that of chlorine, which was lower in MR cells (40 mmol l-1). The concentration of sodium in the PE cells decreased slightly after exposure of the fish to low external [Na+] (25 µmol l-1) for 7 days but increased greatly within 5 min of subsequent exposure to 1 mmol l-1 external Na+. These changes in external [Na+] had no significant effect on MR cells. Exposure of fish to low [Cl-] (25 µmol l-1) had no effect on PE or MR cells, but on exposure to 1 mmol l-1 Cl- the concentrations of chlorine, phosphorus and potassium in both types of cells increased, whilst the intracellular sodium concentration decreased only in MR cells. The PE cells were little affected by exposure of the fish to the carbonic anhydrase inhibitor acetazolamide. In contrast, 0.5 mmol l-1 external acetazolamide caused a significant decrease in intracellular phosphorus, chlorine and potassium concentrations in MR cells. This suggests that the PE cells are the sites of sodium uptake in the gills of the brown trout and that chloride uptake occurs via the MR cells. These results are discussed with respect to the sites and possible mechanisms of ionic exchange in freshwater vertebrates.

  8. A novel ion-exclusion chromatography-mass spectrometry method to measure concentrations and cycling rates of carbohydrates and amino sugars in freshwaters.

    Science.gov (United States)

    Horňák, Karel; Pernthaler, Jakob

    2014-10-24

    The concentrations of free neutral carbohydrates and amino sugars were determined in freshwater samples of distinct matrix complexity, including meso-, eu- and dystrophic lakes and ponds, using high-performance ion-exclusion chromatography (HPIEC) coupled to mass spectrometry (MS). In contrast to other methods, our approach allowed the quantification of free neutral carbohydrates and amino sugars at low nM concentrations without derivatization, de-salting or pre-concentration. New sample preparation procedures were applied prior to injection employing syringe and hollow fiber filtration. Analytes were separated on a strong cation exchange resin under 100% aqueous conditions using 0.1% formic acid as a mobile phase. To minimize background noise in MS, analytes were detected in a multiple reaction monitoring scan mode with double ion filtering. Detection limits of carbohydrates and amino sugars ranged between 0.2 and 2nM at a signal-to-noise ratio >5. Error ranged between 1 and 12% at 0.5-500nM levels. Using a stable isotope dilution approach, both the utilization and recycling of glucose in Lake Zurich was observed. In contrast, N-acetyl-glucosamine was equally rapidly consumed but there was no visible de novo production. The simple and rapid sample preparation makes our protocol suitable for routine analyses of organic compounds in freshwater samples. Application of stable isotope tracers along with accurate measures of carbohydrate and amino sugar concentrations enables novel insights into the compound in situ dynamics. Copyright © 2014 Elsevier B.V. All rights reserved.