Plasma membrane surface potential: dual effects upon ion uptake and toxicity
USDA-ARS?s Scientific Manuscript database
Electrical properties of plasma membranes (PMs), partially controlled by the ionic composition of the bathing medium, play significant roles in the distribution of ions at the exterior surface of PMs and in the transport of ions across PMs. The effects of coexistent cations (commonly Al3+, Ca2+, Mg...
NASA Technical Reports Server (NTRS)
Brinca, Armando L.; Tsurutani, Bruce T.
1989-01-01
The effect of multiple (singly ionized) coexisting newborn ion species on the stability of low-frequency electromagnetic waves was investigated using a plasma model in which solar wind magnetoplasma is made up of isotropic Maxwellian electron and proton populations with a common number density of 4.95/cu cm and temperatures equal to 17.2 eV and 6.9 eV, respectively. It is shown that the effect of multiple ions on wave growth, for given background magnetoplasma conditions and relative densities, depends not only on their mass but also on the physical nature of the wave modes. If the ion masses are disparate, each one of the coexisting ion beams tends to stimulate instabilities without undue influence from the other species. If the masses of newborn ions are similar, they can strongly catalyze wave growth of fluidlike nonresonant modes, but bring about weak growth enhancements in cyclotron resonant instabilities.
Selective recognition of dysprosium(III) ions by enhanced chemiluminescence CdSe quantum dots
NASA Astrophysics Data System (ADS)
Hosseini, Morteza; Ganjali, Mohammad R.; Vaezi, Zahra; Faridbod, Farnoush; Arabsorkhi, Batool; Sheikhha, Mohammad H.
2014-03-01
The intensity of emitted light from CdSe quantum dots (QDs)-H2O2 is described as a novel chemiluminescence (CL) reaction for determination of dysprosium. This reaction is based on the catalytic effect of Dy3+ ions, causing a significant increase in the light emission, as a result of the reaction of quantum dots (QDs) with hydrogen peroxide. In the optimum conditions, this method was satisfactorily described by linear calibration curve in the range of 8.3 × 10-7-5.0 × 10-6 M, the detection limit of 6.0 × 10-8 M, and the relative standard deviation for five determinations of 2.5 × 10-6 M Dy3+ 3.2%. The main experimental advantage of the proposed method is its selective to Dy3+ ions compared with common coexisting cations, therefore, it was successfully applied for the determination of dysprosium ions in water samples.
Comparative toxicity of silver nanoparticles and silver ions to Escherichia coli.
Choi, Yoojin; Kim, Hyun-A; Kim, Kyoung-Woong; Lee, Byung-Tae
2018-04-01
With the increase in silver (Ag)-based products in our lives, it is essential to test the potential toxicity of silver nanoparticles (AgNPs) and silver ions (Ag ions) on living organisms under various conditions. Here, we investigated the toxicity of AgNPs with Ag ions to Escherichia coli K-12 strain under various conditions. We observed that both AgNPs and Ag ions display antibacterial activities, and that Ag ions had higher toxicity to E. coli K-12 strain than AgNPs under the same concentrations. To understand the toxicity of AgNPs at a cellular level, reactive oxygen species (ROS) enzymes were detected for use as antioxidant enzymatic biomarkers. We have also studied the toxicity of AgNPs and Ag ions under various coexistence conditions including: fixed total concentration, with a varied the ratio of AgNPs to Ag ions; fixed the AgNPs concentration and then increased the Ag ions concentration; fixed Ag ions concentration and then increasing the AgNPs concentration. Exposure to AgNPs and Ag ions clearly had synergistic toxicity; however, decreased toxicity (for a fixed AgNPs concentration of 5mg/L, after increasing the Ag ions concentration) to E. coli K-12 strain. AgNPs and Ag ions in the presence of L-cysteine accelerated the bacterial cell growth rate, thereby reducing the bioavailability of Ag ions released from AgNPs under the single and coexistence conditions. Further works are needed to consider this potential for AgNPs and Ag ions toxicity across a range of environmental conditions. As silver nanoparticles (AgNPs)-based products are being broadly used in commercial industries, an ecotoxicological understanding of the AgNPs being released into the environment should be further considered. Here, we investigate the comparative toxicity of AgNPs and silver ions (Ag ions) to Escherichia coli K-12 strain, a representative ecotoxicological bioreporter. This study showed that toxicities of AgNPs and Ag ions to E. coli K-12 strain display different relationships when existing individually or when coexisting, and in the presence of L-cysteine materials. These findings suggest that the toxicology research of nanomaterials should consider conditions when NPs coexist with and without their bioavailable ions. Copyright © 2017. Published by Elsevier B.V.
Zhang, Xiaoyu; van Hulzen, Martijn; Singh, Deepak P; Brownrigg, Alex; Wright, Jonathan P; van Dijk, Niels H; Wagemaker, Marnix
2015-09-23
Phase transitions in Li-ion electrode materials during (dis)charge are decisive for battery performance, limiting high-rate capabilities and playing a crucial role in the cycle life of Li-ion batteries. However, the difficulty to probe the phase nucleation and growth in individual grains is hindering fundamental understanding and progress. Here we use synchrotron microbeam diffraction to disclose the cycling rate-dependent phase transition mechanism within individual particles of LiFePO4, a key Li-ion electrode material. At low (dis)charge rates well-defined nanometer thin plate-shaped domains co-exist and transform much slower and concurrent as compared with the commonly assumed mosaic transformation mechanism. As the (dis)charge rate increases phase boundaries become diffuse speeding up the transformation rates of individual grains. Direct observation of the transformation of individual grains reveals that local current densities significantly differ from what has previously been assumed, giving new insights in the working of Li-ion battery electrodes and their potential improvements.
Direct view on the phase evolution in individual LiFePO4 nanoparticles during Li-ion battery cycling
Zhang, Xiaoyu; van Hulzen, Martijn; Singh, Deepak P.; Brownrigg, Alex; Wright, Jonathan P.; van Dijk, Niels H.; Wagemaker, Marnix
2015-01-01
Phase transitions in Li-ion electrode materials during (dis)charge are decisive for battery performance, limiting high-rate capabilities and playing a crucial role in the cycle life of Li-ion batteries. However, the difficulty to probe the phase nucleation and growth in individual grains is hindering fundamental understanding and progress. Here we use synchrotron microbeam diffraction to disclose the cycling rate-dependent phase transition mechanism within individual particles of LiFePO4, a key Li-ion electrode material. At low (dis)charge rates well-defined nanometer thin plate-shaped domains co-exist and transform much slower and concurrent as compared with the commonly assumed mosaic transformation mechanism. As the (dis)charge rate increases phase boundaries become diffuse speeding up the transformation rates of individual grains. Direct observation of the transformation of individual grains reveals that local current densities significantly differ from what has previously been assumed, giving new insights in the working of Li-ion battery electrodes and their potential improvements. PMID:26395323
NASA Astrophysics Data System (ADS)
Luo, Aoheng; Wang, Hongqing; Wang, Yuyuan; Huang, Qiao; Zhang, Qin
2016-11-01
A novel rhodamine-based dual probe Rh-2 for trivalent ferric ions (Fe3 +) was successfully designed and synthesized, which exhibited a highly sensitive and selective recognition towards Fe3 + with an enhanced fluorescence emission in methanol-water media (v/v = 7/3, pH = 7.2). The probe Rh-2 could be applied to the determination of Fe3 + with a linear range covering from 3.0 × 10- 7 to 1.4 × 10- 5 M and a detection limit of 1.24 × 10- 8 M. Meanwhile, the binding ratio of Rh-2 and Fe3 + was found to be 1:1. Most importantly, the fluorescence and color signal changes of the Rh-2 solution were specific to Fe3 + over other commonly coexistent metal ions. Moreover, the probe Rh-2 has been used to image Fe3 + in living cells with satisfying results.
Biosorption and desorption of Cd2+ from wastewater by dehydrated shreds of Cladophora fascicularis
NASA Astrophysics Data System (ADS)
Deng, Liping; Zhu, Xiaobin; Su, Yingying; Su, Hua; Wang, Xinting
2008-02-01
The adsorption and desorption of algae Cladophora fascicularis and their relation with initial Cd2+ concentration, initial pH, and co-existing ions were studied. Adsorption equilibrium and biosorption kinetics were established from batch experiments. The adsorption equilibrium was adequately described by the Langmuir isotherm, and biosorption kinetics was in pseudo-second order model. The experiment on co-existing ions showed that the biosorption capacity of biomass decreased with an increasing concentration of competing ions. Desorption experiments indicated that EDTA was efficient desorbent for recovery from Cd2+. With high capacities of metal biosorption and desorption, the biomass of Cladophora fascicularis is promising as a cost-effective biosorbent for the removal of Cd2+ from wastewater.
Effect of Coexisting Ions on Adsorption of Arsenic by Metal Oxides
NASA Astrophysics Data System (ADS)
Meng, Xiaoguang; Shi, Qiantao; Christodoulatos, Christos
2017-04-01
Iron hydroxides and nano TiO2 are commonly used adsorbents for removal of arsenic in water. Iron hydroxides also play an important role in controlling the fate and transport of arsenic in groundwater. Co-existing anions, such as phosphate, silicate, and bicarbonate could significantly affect the adsorption capacity of the adsorbents for arsenate and arsenite and increase their mobility in groundwater aquifers. Arsenate and arsenite interactions at the solid-water interface were investigated using electrophoretic mobility (EM) measurements, Fourier transform infrared (FTIR) spectroscopy, and extended X-ray absorption fine structure (EXAFS) spectroscopy. Electrochemical scanning tunneling microscopy (ECSTM) and in-situ flow cell ATR-FTIR were applied to investigate the interactions between As(III), As(V) and carbonate in water and at the solid-water interface. The experimental results suggested that arsenate and arsenite formed inner-sphere complexes with the hydroxide groups on the adsorbents. Arsenite and carbonate could form ternary surface complexes with the hydroxyl groups on iron hydroxide.
NASA Astrophysics Data System (ADS)
Elkamash, I. S.; Kourakis, I.
2018-05-01
The criteria for occurrence and the dynamical features of electrostatic solitary waves in a homogeneous, unmagnetized ultradense plasma penetrated by a negative ion beam are investigated, relying on a quantum hydrodynamic model. The ionic components are modeled as inertial fluids, while the relativistic electrons obey Fermi-Dirac statistics. A new set of exact analytical conditions for localized solitary pulses to exist is obtained, in terms of plasma density. The algebraic analysis reveals that these depend sensitively on the negative ion beam characteristics, that is, the beam velocity and density. Particular attention is paid to the simultaneous occurrence of positive and negative potential pulses, identified by their respective distinct ambipolar electric field structure forms. It is shown that the coexistence of positive and negative potential pulses occurs in a certain interval of parameter values, where the ion beam inertia becomes significant.
Khoshbin, Zahra; Housaindokht, Mohammad Reza; Verdian, Asma; Bozorgmehr, Mohammad Reza
2018-09-30
The serious threats of mercury (Hg 2+ ) and lead (Pb 2+ ) ions for the public health makes it important to achieve the detection methods of the ions with high affinity and specificity. Metal ions usually coexist in some environment and foodstuff or clinical samples. Therefore, it is very necessary to develop a fast and simple method for simultaneous monitoring the amount of metal ions, especially when Hg 2+ and Pb 2+ coexist. DNAzyme-based biosensors and aptasensors have been highly regarded for this purpose as two main groups of the functional nucleic acid (FNA)-based biosensors. In this review, we summarize the recent achievements of functional nucleic acid-based biosensors for the simultaneous detection of Hg 2+ and Pb 2+ ions in two main optical and electrochemical groups. The tremendous interest in utilizing the various nanomaterials is also highlighted in the fabrication of the FNA-based biosensors. Finally, some results are presented based on the advantages and disadvantages of the studied FNA-based biosensors to compare their validation. Copyright © 2018 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Suzuki, T. T.; Sakai, O.
2017-04-01
Surface magnetism is analyzed by spin-dependent He+-ion neutralization (the Auger neutralization) in the vicinity of a surface using an electron spin-polarized low-energy He+-ion beam [spin-polarized ion scattering spectroscopy (SP-ISS)]. Recently, spin-orbit coupling (SOC) has been found to act as another mechanism of spin-dependent low-energy He+-ion scattering. Thus, it is crucial for surface magnetism analyses by SP-ISS to separate those two mechanisms. In the present study, we investigated the spin-induced asymmetry in scattering of low-energy He+ ions on ultrathin Au and Sn films as well as the oxygen adsorbate on a magnetized-Fe(100) surface where these two mechanisms may coexist. We found that the Fe surface magnetism immediately disappeared with the growth of those overlayers. On the other hand, we observed no induced spin polarization in the Au and Sn thin films even in the very initial stage of the growth. We also observed that the spin asymmetry of the O adsorbate was induced by the magnetism of the underlying Fe substrate. The present study demonstrates that the two mechanisms of the spin-asymmetric He+-ion scattering (the ion neutralization and SOC) can be separated by an azimuthal-angle-resolved SP-ISS measurement.
Doping effects on the relaxation of frustration and magnetic properties of YMn0.9Cu0.1O3
NASA Astrophysics Data System (ADS)
Xiao, L. X.; Xia, Z. C.; Wang, X.; Ni, Y.; Yu, W.; Shi, L. R.; Jin, Z.; Xiao, G. L.
2017-12-01
The crystal structure and magnetic properties of hexagonal YMn0.9Cu0.1O3 single crystal are systematically investigated. The refinement results of XRD show the lattice constant decreases, which is unusually due to the doped Cu2+ ion has a larger ionic radius than the Mn3+ ions. The XPS results show that the coexistence of Mn2+, Mn3+ and Mn4+ ions in YMn0.9Cu0.1O3 single crystal. Magnetization measurements show that Cu doped YMn0.9Cu0.1O3 and parent YMnO3 have almost the same antiferromagnetic transition temperature TN, which indicates the AFM interaction is robust in the geometry frustrated system. Because doping directly destroy some of the Mn3+ ions nets, the relaxation of frustration of Mn in-plane 2D triangular geometry network leads to the significantly decrease of Mn3+ ions AFM interaction. In addition, the coexistence and competition between the ferromagnetic and antiferromagnetic interactions among the Mn2+, Mn3+ and Mn4+ ions lead to a complicated and irreversible magnetization behavior in YMn0.9Cu0.1O3 single crystal.
NASA Astrophysics Data System (ADS)
Iijima, Mayumi; Moriwaki, Yutaka
1989-05-01
The crystal growth of octacalcium phosphate (OCP) is of particular interest, since there is a possibility that OCP is formed in the early stage of tooth enamel formation. In this study, the effects of CO2-3, Mg2+ and F-ions on the morphology of OCP were investigated in a membrane system, where a cation selective membrane was used to simulate amelogenesis. Reactions were carried out at pH 6.3, 6.5 and 6.8 for 3 days at 37°C. In most cases, these ions suppressed the crystal growth in the c-axis direction of OCP, particularly when they coexisted. The morphology of OCP crystal changed from ribbon-like to flake-like, depending on the inhibitory activity. The inhibitory activity, particularly that of F - ion, was suppressed at pH lower than pH 6.8. Antagonistic effect of Mg2+ and F-ion was observed at pH 6.5. In the case of F - ion, OCP crystals showed a unique pattern, which suggests hydrolysis of OCP and subsequent growth of apatite. These findings indicate that inorganic ions, particularly F - ion, influence the growth of OCP. Although CO2-3, Mg2+andF-ions coexisted, extended growth in the c-axis direction of OCP took place at pH 6.0.
Wang, Qingsong; Sun, Jinhua; Chen, Chunhua
2009-08-15
The thermal stability of lithiated graphite in the presence of solvents, electrolytes and LiPF(6) salt was studied using C80 micro-calorimeter. The presence of cyclic carbonates or linear carbonates increases the activity of Li(x)C(6)-solvent coexisting system, especially for the Li(x)C(6)-linear carbonates one. LiPF(6) was detected that it increases the activity greatly of its coexisting system with lithiated graphite. The coexisting system of Li(x)C(6) with the electrolyte of LiPF(6)/ethylene carbonate+diethyl carbonate shows less thermal stability, which is attributed to the activity between diethyl carbonate and Li(x)C(6). This also agrees with the experiment result of Li(x)C(6)-diethyl carbonate coexisting system.
Coexisting Disorders and Academic Achievement among Children with ADHD
ERIC Educational Resources Information Center
Barnard-Brak, Lucy; Sulak, Tracey N.; Fearon, Danielle D.
2011-01-01
Objective: ADHD is a commonly diagnosed neuropsychological disorder among school-aged children with reported high rates of coexisting or comorbid disorders. As ADHD has been associated with academic underachievement, the current study examines this association in view of the presence of coexisting disorders. The purpose of the current study is to…
NASA Astrophysics Data System (ADS)
Yue, Xiao-li; Wang, Zhao-qing; Li, Chao-rui; Yang, Zheng-yin
2018-03-01
In this paper, a simple naphthalene-based derivative (HL) has been designed and synthesized as a Al3 +-selective fluorescent chemosensor based on the PET mechanism. HL exhibited high selectivity and sensitivity towards Al3 + over other commonly coexisting metal ions in ethanol with a detection limit of 2.72 nM. The 1:1 binding stoichiometry of the complex (HL-Al3 +) was determined from the Job's plot based on fluorescence titrations and the ESI-MS spectrum data. Moreover, the binding site of HL with Al3 + was assured by the 1H NMR titration experiment. The binding constant (Ka) of the complex (HL-Al3 +) was calculated to be 5.06 × 104 M- 1 according to the Benesi-Hildebrand equation. In addition, the recognizing process of HL towards Al3 + was chemically reversible by adding Na2EDTA. Importantly, HL could directly and rapidly detect aluminum ion through the filter paper without resorting to additional instrumental analysis.
Li, Zhenhua; Chang, Xijun; Hu, Zheng; Huang, Xinping; Zou, Xiaojun; Wu, Qiong; Nie, Rong
2009-07-15
A new method that utilizes zincon-modified activated carbon (AC-ZCN) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III) and Pb(II) prior to the measurement by inductively coupled plasma optical emission spectrometry (ICP-OES). The separation/preconcentration conditions of analytes were investigated, including effects of pH, the shaking time, the sample flow rate and volume, the elution condition and the interfering ions. At pH 4, the maximum adsorption capacity of Cr(III) and Pb(II) onto the AC-ZCN were 17.9 and 26.7 mg g(-1), respectively. The adsorbed metal ions were quantitatively eluted by 1 mL of 0.1 mol L(-1) HCl. Common coexisting ions did not interfere with the separation. According to the definition of IUPAC, the detection limits (3 sigma) of this method for Cr(III) and Pb(II) were 0.91 and 0.65 ng mL(-1), respectively. The relative standard deviation under optimum condition is less than 3.5% (n=8). The method has been applied for the determination of Cr(III) and Pb(II) in biological materials and water samples with satisfactory results.
Effect of coexisting Al(III) ions on Pb(II) sorption on biochars: Role of pH buffer and competition.
Yang, Yuxi; Zhang, Weihua; Qiu, Hao; Tsang, Daniel C W; Morel, Jean-Louis; Qiu, Rongliang
2016-10-01
Biochar is being widely considered as a promising amendment agent for immobilizing heavy metals in contaminated acidic soils, where plenty of soluble Al(III) ions exist. In view of uncertain significance of the effects of coexisting Al(III) on Pb(II) sorption by biochars, this study used kenaf core biochar (KB550; high carbon, low ash) and sewage sludge biochar (SB550; low carbon, high ash) pyrolyzed at 550 °C to elucidate the influence of coexisting Al(III) species and biochars' mineral components on Pb(II) immobilization conducted in aqueous solution with initial pHs of 3.0-4.5. Results showed that Al(III) reduced Pb(II) sorption on KB550 primarily via pH buffering against biochar alkalinity, thus inhibiting lead carbonate formation. In contrast, the reduction on SB550 mainly resulted from direct competition for sorption sites, especially on Fe-rich phengite 2M1 and metakaolinite. Because of Pb-P precipitation and Pb-K interlayer exchange, the residual Pb(II) adsorption capacity resistant to coexisting Al(III) was 3-5 times higher on SB550 than on KB550. The Pb-K interlayer exchange was enhanced by lower pH and coexisting Al(III), while Pb-P precipitation was the dominant Pb(II) sorption mechanism on SB550 resistant to Al(III) buffering and competition at higher pH. Application of these two biochars as amendments confirmed that the mineral-rich SB550 was more suitable for Pb(II) immobilization in acidic soils with high levels of extractable Al(III). Copyright © 2016 Elsevier Ltd. All rights reserved.
The prevalence of transpancreatic common hepatic artery and coexisting variant anatomy.
Ishigami, Kousei; Nishie, Akihiro; Asayama, Yoshiki; Ushijima, Yasuhiro; Takayama, Yukihisa; Okamoto, Daisuke; Fujita, Nobuhiro; Yoshizumi, Tomoharu; Harimoto, Norifumi; Ohtsuka, Takao; Nakata, Kohei; Honda, Hiroshi
2018-05-01
We studied the prevalence of the transpancreatic common hepatic artery (tp-CHA) and coexisting variant anatomy. The study group comprised 788 consecutive liver transplant donor candidates who had undergone thin-section multidetector-row computed tomography (MDCT) studies to investigate vascular anatomy. Multiplanar reformatted (MPR) images obtained from the arterial phase were retrospectively reviewed to assess the presence/absence of the tp-CHA. Five cases of tp-CHA with pancreaticobiliary tumors were also included in an investigation of the presence/absence of variant hepatic arteries, celiac stenosis, and circumportal pancreas. Three of the 788 (0.38%) donor candidates had a tp-CHA. Overall, eight tp-CHA cases were assessed for coexisting variant anatomy. Seven of these eight cases had a hepatomesenteric trunk, six had celiac stenosis, and two had a circumportal pancreas. The prevalence of the tp-CHA was 0.38% (approx. one in 260 in normal populations). A tp-CHA can commonly be associated with a hepatomesenteric trunk and celiac stenosis. A circumportal pancreas can also coexist with a tp-CHA. Clin. Anat. 31:598-604, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Release of major ions during rigor mortis development in kid Longissimus dorsi muscle.
Feidt, C; Brun-Bellut, J
1999-01-01
Ionic strength plays an important role in post mortem muscle changes. Its increase is due to ion release during the development of rigor mortis. Twelve alpine kids were used to study the effects of chilling and meat pH on ion release. Free ions were measured in Longissimus dorsi muscle by capillary electrophoresis after water extraction. All free ion concentrations increased after death, but there were differences between ions. Temperature was not a factor affecting ion release in contrast to ultimate pH value. Three release mechanisms are believed to coexist: a passive binding to proteins, which stops as pH decreases, an active segregation which stops as ATP disappears and the production of metabolites due to anaerobic glycolysis.
Generalized Dicke Nonequilibrium Dynamics in Trapped Ions
NASA Astrophysics Data System (ADS)
Genway, Sam; Li, Weibin; Ates, Cenap; Lanyon, Benjamin P.; Lesanovsky, Igor
2014-01-01
We explore trapped ions as a setting to investigate nonequilibrium phases in a generalized Dicke model of dissipative spins coupled to phonon modes. We find a rich dynamical phase diagram including superradiantlike regimes, dynamical phase coexistence, and phonon-lasing behavior. A particular advantage of trapped ions is that these phases and transitions among them can be probed in situ through fluorescence. We demonstrate that the main physical insights are captured by a minimal model and consider an experimental realization with Ca+ ions trapped in a linear Paul trap with a dressing scheme to create effective two-level systems with a tunable dissipation rate.
Ahmad, Munir; Ahmad, Mahtab; Usman, Adel R A; Al-Faraj, Abdullah S; Abduljabbar, Adel S; Al-Wabel, Mohammad I
2017-09-18
Biochar (BC) was produced from date palm tree leaves and its composites were prepared with nano zerovalent iron (nZVI-BC) and hen eggshell powder (EP-BC). The produced BC and its composites were characterized by SEM, XRD, BET, and FTIR for surface structural, mineralogical, and chemical groups and tested for their efficiency for nitrate removal from aqueous solutions in the presence and absence of chloride ions. The incidence of graphene and nano zerovalent iron (Fe 0 ) in the nZVI-BC composite was confirmed by XRD. The nZVI-BC composite possessed highest surface area (220.92 m 2 g -1 ), carbon (80.55%), nitrogen (3.78%), and hydrogen (11.09%) contents compared to other materials. Nitrate sorption data was fitted well to the Langmuir (R 2 = 0.93-0.98) and Freundlich (R 2 = 0.90-0.99) isotherms. The sorption kinetics was adequately explained by the pseudo-second-order, power function, and Elovich models. The nZVI-BC composite showed highest Langmuir predicted sorption capacity (148.10 mg g -1 ) followed by EP-BC composite (72.77 mg g -1 ). In addition to the high surface area, the higher nitrate removal capacity of nZVI-BC composite could be attributed to the combination of two processes, i.e., chemisorption (outer-sphere complexation) and reduction of nitrate to ammonia or nitrogen by Fe 0 . The appearance of Fe-O stretching and N-H bonds in post-sorption FTIR spectra of nZVI-BC composite suggested the occurrence of redox reaction and formation of Fe compound with N, such as ferric nitrate (Fe(NO 3 ) 3 ·9H 2 O). Coexistence of chloride ions negatively influenced the nitrate sorption. The decrease in nitrate sorption with increasing chloride ion concentration was observed, which could be due to the competition of free active sites on the sorbents between nitrate and chloride ions. The nZVI-BC composite exhibited higher nitrate removal efficiency compared to other materials even in the presence of highest concentration (100 mg L -1 ) of coexisting chloride ion.
Rai, Neeraj; Maginn, Edward J
2012-01-01
Atomistic Monte Carlo simulations are used to compute vapour-liquid coexistence properties of a homologous series of [C(n)mim][NTf2] ionic liquids, with n = 1, 2, 4, 6. Estimates of the critical temperatures range from 1190 K to 1257 K, with longer cation alkyl chains serving to lower the critical temperature. Other quantities such as critical density, critical pressure, normal boiling point, and accentric factor are determined from the simulations. Vapour pressure curves and the temperature dependence of the enthalpy of vapourisation are computed and found to have a weak dependence on the length of the cation alkyl chain. The ions in the vapour phase are predominately in single ion pairs, although a significant number of ions are found in neutral clusters of larger sizes as temperature is increased. It is found that previous estimates of the critical point obtained from extrapolating experimental surface tension data agree reasonably well with the predictions obtained here, but group contribution methods and primitive models of ionic liquids do not capture many of the trends observed in the present study
NASA Astrophysics Data System (ADS)
Iwaoka, C.; Hyodo, F.; Taniguchi, T.; Shi, W.; Du, S.; Yamanaka, N.; Tateno, R.
2017-12-01
The symbiotic relationship between dominant canopy trees and soil microbes such as mycorrhiza or nitrogen (N) fixer are important determinants of soil N dynamics of a forest. However, it is not known how and to what extent the symbiotic relationship of dominant canopy trees with soil microbes affect the N source of co-existing trees in forest. We measured the δ15N of surface soils (0-10 cm), leaves, and roots of the dominant canopy trees and common understory trees in an arbuscular mycorrhizal N-fixing black locust (Robinia pseudoacacia) plantation and an ectomycorrhizal oak (Quercus liaotungensis) natural forest in a China dryland. We also analyzed the soil dissolved N content in soil extracts and absorbed by ion exchange resin, and soil ammonia-oxidizer abundance using real-time PCR. The δ15N of soil and leaves were higher in the black locust forest than in the oak forest, although the δ15N of fine roots was similar in the two forests, in co-existing understory trees as well as dominant canopy trees. Accordingly, the δ15N of leaves was similar to or higher than that of fine roots in the black locust forest, whereas it was consistently lower than that of fine roots in the oak forest. In the black locust forest, the soil dissolved organic N and ammonium N contents were less abundant but the nitrate N contents in soils and absorbed by the ion exchange resin and ammonia-oxidizer abundance were greater, due to N fixation or less uptake of organic N from arbuscular mycorrhiza. In contrast, the soil dissolved organic N and ammonium N contents were more abundant in the oak forest, whereas the N content featured very low nitrate, due to ectomycorrhizal ability to access organic N. These results suggest that the main N source is nitrate N in the black locust forest, but dissolved organic N or ammonium N in the oak forest. N fixation or high N loss due to high N availability would cause high δ15N in soil and leaves in black locust forest. On the other hand, low soil N availability in the oak forest may make 15N fractionation more active in roots via mycorrhizal association, resulting in higher δ15N in fine roots than in leaves. In conclusion, the symbiotic relationship between dominant canopy trees and soil microbes affected the N source of not only the dominant trees but also co-existing understory trees via the control of soil N dynamics.
NASA Astrophysics Data System (ADS)
Yabunaka, Shunsuke; Onuki, Akira
2017-09-01
We examine an electric double layer containing an antagonistic salt in an aqueous mixture, where the cations are small and hydrophilic but the anions are large and hydrophobic. In this situation, a strong coupling arises between the charge density and the solvent composition. As a result, the anions are trapped in an oil-rich adsorption layer on a hydrophobic wall. We then vary the surface charge density σ on the wall. For σ >0 the anions remain accumulated, but for σ <0 the cations are attracted to the wall with increasing |σ |. Furthermore, the electric potential drop Ψ (σ ) is nonmonotonic when the solvent interaction parameter χ (T ) exceeds a critical value χc determined by the composition and the ion density in the bulk. This leads to a first-order phase transition between two kinds of electric double layers with different σ and common Ψ . In equilibrium such two-layer regions can coexist. The steric effect due to finite ion sizes is crucial in these phenomena.
Xue, Fang-Min; Wang, He-Fang
2012-09-15
Neodymium (Nd(3+)) doped nanomaterials exhibited the unique near infrared (NIR) luminescence properties. However, the application of Nd-doped nanomaterials to chemosensors was rarely explored. Herein, the water-soluble 2-aminoethyl dihydrogen phosphate stabilized Nd-doped LaF(3) (ADP-Nd-LaF(3)) nanoparticles were explored as the NIR probe for chemosensors. The NIR emission intensity at 1061 nm of ADP-Nd-LaF(3) nanoparticles kept stable in the aqueous solution of various pH and coexisting of most common metal ions except copper ion, consequently, the ADP-Nd-LaF(3) nanoparticles were developed as a high selective NIR probe for Cu(II). The NIR emission of ADP-Nd-LaF(3) exhibits a linear quenching response to Cu(II) in the range 5-100 μM, with a detection limit of 0.8 μM. The precision of eleven replicate detections of 5 μM Cu(II) was 0.5% (RSD). The recovery of spiked Cu(II) in human urine and waste water samples ranged from 102 to 109%. The possible mechanism of Cu(II)-induced fluorescence quenching of ADP-Nd-LaF(3) nanoparticles was also discussed. Copyright © 2012 Elsevier B.V. All rights reserved.
Opting out against defection leads to stable coexistence with cooperation.
Zhang, Bo-Yu; Fan, Song-Jia; Li, Cong; Zheng, Xiu-Deng; Bao, Jian-Zhang; Cressman, Ross; Tao, Yi
2016-10-24
Cooperation coexisting with defection is a common phenomenon in nature and human society. Previous studies for promoting cooperation based on kin selection, direct and indirect reciprocity, graph selection and group selection have provided conditions that cooperators outcompete defectors. However, a simple mechanism of the long-term stable coexistence of cooperation and defection is still lacking. To reveal the effect of direct reciprocity on the coexistence of cooperation and defection, we conducted a simple experiment based on the Prisoner's Dilemma (PD) game, where the basic idea behind our experiment is that all players in a PD game should prefer a cooperator as an opponent. Our experimental and theoretical results show clearly that the strategies allowing opting out against defection are able to maintain this stable coexistence.
Feng, Xin-xin; Du, Er-deng; Guo, Ying-qing; Li, Hua-jie; Liu, Xiang; Zhou, Fang
2015-06-01
Organic sunscreens continue to enter the environment through people's daily consumption, and become a kind of emerging contaminants. The photochemical degradation of benzophenone-3 (BP-3) in water by UV/H2O2 process was investigated. Several factors, including the initial BP-3 concentration, H2O2 concentration, UV light intensity, coexisting cations and anions, humic acid and tert-butyl alcohol, were also discussed. The results showed that BP-3 degradation rate constant decreased with increasing initial BP-3 concentration, while increased with increasing H2O2 dosage and UV intensity. Coexisting anions could reduce the degradation rate, while coexisting ferric ions could stimulate the production of OH through Fenton-like reaction, further significantly accelerated BP-3 degradation process. The BP-3 degradation would be inhibited by humic acid or tert-butyl alcohol. The electrical energy per order (E(Eo)) values were also calculated to evaluate the cost of BP-3 degradation by UV/H2O2 process. The addition of ferric ions significantly reduced the value of E(Eo). The investigation of processing parameter could provide a reference for the practical engineering applications of benzophenone compounds removal by UV/H2O2 process.
Body size mediated coexistence of consumers competing for resources in space
Basset, A.; Angelis, D.L.
2007-01-01
Body size is a major phenotypic trait of individuals that commonly differentiates co-occurring species. We analyzed inter-specific competitive interactions between a large consumer and smaller competitors, whose energetics, selection and giving-up behaviour on identical resource patches scaled with individual body size. The aim was to investigate whether pure metabolic constraints on patch behaviour of vagile species can determine coexistence conditions consistent with existing theoretical and experimental evidence. We used an individual-based spatially explicit simulation model at a spatial scale defined by the home range of the large consumer, which was assumed to be parthenogenic and semelparous. Under exploitative conditions, competitive coexistence occurred in a range of body size ratios between 2 and 10. Asymmetrical competition and the mechanism underlying asymmetry, determined by the scaling of energetics and patch behaviour with consumer body size, were the proximate determinant of inter-specific coexistence. The small consumer exploited patches more efficiently, but searched for profitable patches less effectively than the larger competitor. Therefore, body-size related constraints induced niche partitioning, allowing competitive coexistence within a set of conditions where the large consumer maintained control over the small consumer and resource dynamics. The model summarises and extends the existing evidence of species coexistence on a limiting resource, and provides a mechanistic explanation for decoding the size-abundance distribution patterns commonly observed at guild and community levels. ?? Oikos.
Synergistic cross-scale coupling of turbulence in a tokamak plasma
DOE Office of Scientific and Technical Information (OSTI.GOV)
Howard, N. T., E-mail: nthoward@psfc.mit.edu; Holland, C.; White, A. E.
2014-11-15
For the first time, nonlinear gyrokinetic simulations spanning both the ion and electron spatio-temporal scales have been performed with realistic electron mass ratio ((m{sub D}∕m{sub e}){sup 1∕2 }= 60.0), realistic geometry, and all experimental inputs, demonstrating the coexistence and synergy of ion (k{sub θ}ρ{sub s}∼O(1.0)) and electron-scale (k{sub θ}ρ{sub e}∼O(1.0)) turbulence in the core of a tokamak plasma. All multi-scale simulations utilized the GYRO code [J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] to study the coupling of ion and electron-scale turbulence in the core (r/a = 0.6) of an Alcator C-Mod L-mode discharge shown previously to exhibit an under-predictionmore » of the electron heat flux when using simulations only including ion-scale turbulence. Electron-scale turbulence is found to play a dominant role in setting the electron heat flux level and radially elongated (k{sub r} ≪ k{sub θ}) “streamers” are found to coexist with ion-scale eddies in experimental plasma conditions. Inclusion of electron-scale turbulence in these simulations is found to increase both ion and electron heat flux levels by enhancing the transport at the ion-scale while also driving electron heat flux at sub-ρ{sub i} scales. The combined increases in the low and high-k driven electron heat flux may explain previously observed discrepancies between simulated and experimental electron heat fluxes and indicates a complex interaction of short and long wavelength turbulence.« less
Management of onychomycosis and co-existing tinea pedis.
Lipner, Shari R; Scher, Richard K
2015-05-01
Onychomycosis is a common nail infection that often co-exists with tinea pedis. Surveys have suggested the diseases co-exist in at least one third of patients, although actual numbers may be a lot higher due to significant under-reporting. The importance of evaluating and treating both diseases is being increasingly recognized, however, data on improved outcomes, and the potential to minimize re-infection are limited. We review a recent post hoc analysis of two large studies treating mild to moderate onychomycosis with efinaconazole topical solution, 10%, demonstrating that complete cure rates of onychomycosis are significantly improved when any co-existing tinea pedis is also treated.
Tu, Zhifeng; He, Qun; Chang, Xijun; Hu, Zheng; Gao, Ru; Zhang, Lina; Li, Zhenhua
2009-09-07
A novel method that utilizes 1-(2-formamidoethyl)-3-phenylurea-modified activated carbon (AC-1-(2-formamidoethyl)-3-phenylurea) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of trace levels of Cr(III), Cu(II), Fe(III) and Pb(II) were optimized using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4. And the adsorbed metal ions could be completely eluted by using 2.0 mL 2.0 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.8, 39.9, 77.8 and 17.3 mg g(-1) for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The detection limits of the method were found to be 0.15, 0.41, 0.27 and 0.36 ng mL(-1) for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The relative standard deviation (RSD) of the method was lower than 4.0% (n=8). The method was successfully applied for the preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) in natural and certified samples with satisfactory results.
Li, Zhenhua; Chang, Xijun; Zou, Xiaojun; Zhu, Xiangbing; Nie, Rong; Hu, Zheng; Li, Ruijun
2009-01-26
A new method that utilizes ethylenediamine-modified activated carbon (AC-EDA) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Fe(III), Hg(II) and Pb(II) prior to the measurement by inductively coupled plasma optical emission spectrometry (ICP-OES). The new sorbent was prepared by oxidative surface modification. Experimental conditions for effective adsorption of trace levels of Cr(III), Fe(III), Hg(II) and Pb(II) were optimized with respect to different experimental parameters using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4.0. Complete elution of absorbed metal ions from the sorbent surface was carried out using 3.0 mL of 2% (%w/w) thiourea and 0.5 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.4, 28.9, 60.5 and 49.9 mg g(-1) for Cr(III), Fe(III), Hg(II) and Pb(II), respectively. The time for 94% adsorption of target metal ions was less than 2 min. The detection limits of the method was found to be 0.28, 0.22, 0.09 and 0.17 ng mL(-1) for Cr(III), Fe(III), Hg(II) and Pb(II), respectively. The precision (R.S.D.) of the method was lower 4.0% (n=8). The prepared sorbent as solid-phase extractant was successfully applied for the preconcentration of trace Cr(III), Fe(III), Hg(II) and Pb(II) in natural and certified samples with satisfactory results.
NASA Astrophysics Data System (ADS)
Aragón, Fermin F. H.; Aquino, Juan C. R.; Ramos, Jesus E.; Coaquira, José A. H.; Gonzalez, Ismael; Macedo, Waldemar A. A.; da Silva, Sebastião W.; Morais, Paulo C.
2017-11-01
In this work, we report on a single-pot synthesis route based on a polymeric precursor method used for successfully producing undoped and iron-doped CeO2 nanoparticles with iron contents up to 10.0 mol. %. The formation of high-crystalline nanoparticles with a cubic fluorite structure is determined for all the studied samples. Meanwhile, the magnetic measurements of the undoped ceria nanoparticles revealed the occurrence of ferromagnetism of bound magnetic polarons of a fraction of Ce3+ at room temperature, and only a paramagnetic behavior of Fe3+ ions was determined for Fe-doped ceria nanoparticles. A monotonous reduction of the effective magnetic moment of the Fe3+ ions was determined. It suggests a change from a high-spin to low-spin state of Fe ions as the Fe content is increased. The 3+ valence state of the iron ions has been confirmed by the Fe K-edge X-ray absorption near-edge structure (XANES) and Mössbauer spectroscopy measurements. X-ray photoelectron spectroscopy data analysis evidenced a coexistence of Ce3+ and Ce4+ ions and a decreasing tendency of the relative fraction of Ce3+ ions in the surface region of the particles as the iron content is increased. Although the coexistence of Ce3+ and Ce4+ is confirmed by results obtained via Ce L3-edge XANES measurements, any clear dependence of the relative relation of Ce3+ ions on the iron content is determined, suggesting a homogeneous distribution of Ce3+ and Ce4+-ions in the whole volume of the particles. Ce L3-edge extended X-ray absorption fine structure revealed that the Ce-O bond distance shows a monotonous decrease as the Fe content is increased, which is in good agreement with the shrinking of the unit cell volume with the iron content determined from XRD data analysis, reinforcing the substitutional solution of Ce and Fe ions in the CeO2 matrix.
Wang, Lei; Li, Nanfang; Yao, Xiaoguang; Chang, Guijuan; Zhang, Delian; Heizhati, Mulalibieke; Wang, Menghui; Luo, Qin; Kong, Jianqiong
2017-01-01
Since the control rate of blood pressure is lower in mainland China, the aim of this study is to investigate the proportion of secondary causes and coexisting diseases of hypertension in hypertensive patients. Data on consecutive patients with hypertension who visited the Hypertension Center. Diseases were detected using an established strict screening protocol. Detection rate of secondary causes and coexisting diseases of hypertension was 39.5% among 3003 hypertensive patients. Obstructive sleep apnea (OSA) was the most common, accounting for 24.7% of patients, followed by primary aldosteronism (PA) (5.8%) and PA + OSA (4.9%). Endocrine hypertension accounted for 12.1% of patients, including 10.7% of patients with PA, 1.1% with hypothyroidism, 0.1% with pheochromocytoma, 0.1% with Cushing's syndrome, and 0.1% with hyperthyroidism, respectively. Those who smoke, those who are obese, and those who have diabetes accounted for 31.3%, 27.5%, and 16.6% of total patients, respectively. There were overlapping conditions in secondary causes and coexisting diseases of hypertension. OSA was the most common in each age- and BMI-stratified group. Findings from the current study suggest an increasing frequency of secondary forms of hypertension, highlighting the burden of OSA and PA in hypertensive patients.
Wang, Lei; Yao, Xiaoguang; Chang, Guijuan; Zhang, Delian; Heizhati, Mulalibieke; Wang, Menghui; Luo, Qin; Kong, Jianqiong
2017-01-01
Background Since the control rate of blood pressure is lower in mainland China, the aim of this study is to investigate the proportion of secondary causes and coexisting diseases of hypertension in hypertensive patients. Methods Data on consecutive patients with hypertension who visited the Hypertension Center. Diseases were detected using an established strict screening protocol. Results Detection rate of secondary causes and coexisting diseases of hypertension was 39.5% among 3003 hypertensive patients. Obstructive sleep apnea (OSA) was the most common, accounting for 24.7% of patients, followed by primary aldosteronism (PA) (5.8%) and PA + OSA (4.9%). Endocrine hypertension accounted for 12.1% of patients, including 10.7% of patients with PA, 1.1% with hypothyroidism, 0.1% with pheochromocytoma, 0.1% with Cushing's syndrome, and 0.1% with hyperthyroidism, respectively. Those who smoke, those who are obese, and those who have diabetes accounted for 31.3%, 27.5%, and 16.6% of total patients, respectively. There were overlapping conditions in secondary causes and coexisting diseases of hypertension. OSA was the most common in each age- and BMI-stratified group. Conclusion Findings from the current study suggest an increasing frequency of secondary forms of hypertension, highlighting the burden of OSA and PA in hypertensive patients. PMID:28691036
Further characterization of spectral features attributable to titanium on the moon
NASA Technical Reports Server (NTRS)
Burns, R. G.; Parkin, K. M.; Loeffler, B. M.; Leung, I. S.; Abu-Eid, R. M.
1976-01-01
The following transitions are observed in the electronic absorption spectra of lunar titanaugites: Fe(2+) spin-allowed and spin-forbidden crystal field; Ti(3+) spin allowed and Jahn-Teller split crystal field; Ti(3+)-Ti(4+) CT; Fe(2+)-Ti(4+) CT; and O(2-)-Fe(2+), Ti(3+), Ti(4+) CT. Of these, the transitions involving Ti(3+) are unique to lunar or nonferric-bearing titanaugites. All titanaugites have the Fe(2+) crystal field and Fe(2+)-Ti(4+) CT transitions in common. These features in the diffuse reflectance spectra of lunar materials give rise to the '1.0 band' and to the observed absorption around 0.5-0.6 micron, respectively. Since regolith contains a variety of phases with coexisting Fe(2+), Ti(3+), and Ti(4+) ions, several metal-metal charge transfer processes are possible.
Solubility of NaCl in water by molecular simulation revisited.
Aragones, J L; Sanz, E; Vega, C
2012-06-28
In this paper, the solubility of NaCl in water is evaluated by using computer simulations for three different force fields. The condition of chemical equilibrium (i.e., equal chemical potential of the salt in the solid and in the solution) is obtained at room temperature and pressure to determine the solubility of the salt. We used the same methodology that was described in our previous work [E. Sanz and C. Vega, J. Chem. Phys. 126, 014507 (2007)] although several modifications were introduced to improve the accuracy of the calculations. It is found that the predictions of the solubility are quite sensitive to the details of the force field used. Certain force fields underestimate the experimental solubility of NaCl in water by a factor of four, whereas the predictions of other force fields are within 20% of the experimental value. Direct coexistence molecular dynamic simulations were also performed to determine the solubility of the salt. Reasonable agreement was found between the solubility obtained from free energy calculations and that obtained from direct coexistence simulations. This work shows that the evaluation of the solubility of salts in water can now be performed in computer simulations. The solubility depends on the ion-ion, ion-water, and water-water interactions. For this reason, the prediction of the solubility can be quite useful in future work to develop force fields for ions in water.
Haler, Jean R N; Far, Johann; Aqil, Abdelhafid; Claereboudt, Jan; Tomczyk, Nick; Giles, Kevin; Jérôme, Christine; De Pauw, Edwin
2017-11-01
Ion mobility-mass spectrometry (IM-MS) has emerged as a powerful separation and identification tool to characterize synthetic polymer mixtures and topologies (linear, cyclic, star-shaped,…). Electrospray coupled to IM-MS already revealed the coexistence of several charge state-dependent conformations for a single charge state of biomolecules with strong intramolecular interactions, even when limited resolving power IM-MS instruments were used. For synthetic polymers, the sample's polydispersity allows the observation of several chain lengths. A unique collision cross-section (CCS) trend is usually observed when increasing the degree of polymerization (DP) at constant charge state, allowing the deciphering of different polymer topologies. In this paper, we report multiple coexisting CCS trends when increasing the DP at constant charge state for linear poly(acrylamide) PAAm in the gas phase. This is similar to observations on peptides and proteins. Biomolecules show in addition population changes when collisionally heating the ions. In the case of synthetic PAAm, fragmentation occurred before reaching the energy for conformation conversion. These observations, which were made on two different IM-MS instruments (SYNAPT G2 HDMS and high resolution multi-pass cyclic T-Wave prototype from Waters), limit the use of ion mobility for synthetic polymer topology interpretations to polymers where unique CCS values are observed for each DP at constant charge state. Graphical Abstract ᅟ.
NASA Astrophysics Data System (ADS)
Haler, Jean R. N.; Far, Johann; Aqil, Abdelhafid; Claereboudt, Jan; Tomczyk, Nick; Giles, Kevin; Jérôme, Christine; De Pauw, Edwin
2017-08-01
Ion mobility-mass spectrometry (IM-MS) has emerged as a powerful separation and identification tool to characterize synthetic polymer mixtures and topologies (linear, cyclic, star-shaped,…). Electrospray coupled to IM-MS already revealed the coexistence of several charge state-dependent conformations for a single charge state of biomolecules with strong intramolecular interactions, even when limited resolving power IM-MS instruments were used. For synthetic polymers, the sample's polydispersity allows the observation of several chain lengths. A unique collision cross-section (CCS) trend is usually observed when increasing the degree of polymerization (DP) at constant charge state, allowing the deciphering of different polymer topologies. In this paper, we report multiple coexisting CCS trends when increasing the DP at constant charge state for linear poly(acrylamide) PAAm in the gas phase. This is similar to observations on peptides and proteins. Biomolecules show in addition population changes when collisionally heating the ions. In the case of synthetic PAAm, fragmentation occurred before reaching the energy for conformation conversion. These observations, which were made on two different IM-MS instruments (SYNAPT G2 HDMS and high resolution multi-pass cyclic T-Wave prototype from Waters), limit the use of ion mobility for synthetic polymer topology interpretations to polymers where unique CCS values are observed for each DP at constant charge state. [Figure not available: see fulltext.
Species coexistence through simultaneous fluctuation-dependent mechanisms.
Letten, Andrew D; Dhami, Manpreet K; Ke, Po-Ju; Fukami, Tadashi
2018-06-12
Understanding the origins and maintenance of biodiversity remains one of biology's grand challenges. From theory and observational evidence, we know that variability in environmental conditions through time is likely critical to the coexistence of competing species. Nevertheless, experimental tests of fluctuation-driven coexistence are rare and have typically focused on just one of two potential mechanisms, the temporal storage effect, to the neglect of the theoretically equally plausible mechanism known as relative nonlinearity of competition. We combined experiments and simulations in a system of nectar yeasts to quantify the relative contribution of the two mechanisms to coexistence. Resource competition models parameterized from single-species assays predicted the outcomes of mixed-culture competition experiments with 83% accuracy. Model simulations revealed that both mechanisms have measurable effects on coexistence and that relative nonlinearity can be equal or greater in magnitude to the temporal storage effect. In addition, we show that their effect on coexistence can be both antagonistic and complementary. These results falsify the common assumption that relative nonlinearity is of negligible importance, and in doing so reveal the importance of testing coexistence mechanisms in combination.
Efficient removal of tetracycline with KOH-activated graphene from aqueous solution
Sun, Yiran; Yu, Fei
2017-01-01
Activated graphene absorbents with high specific surface area (SSA) were prepared by an easy KOH-activated method, and were applied in absorbing antibiotics, such as tetracycline (TC). After activation, many micropores were introduced to graphene oxide sheets, leading to higher SSA and many new oxygen-containing functional groups, which gave KOH-activated graphene excellent adsorption capacity (approx. 532.59 mg g−1) of TC. Further study on the adsorption mechanism showed that the Langmuir isotherm model and the pseudo-second-order kinetic model fitted with experiment data. To further understand the adsorption process, the effects of solid–liquid ratio, pH, ionic strength and coexisting ions were also investigated. The results revealed that, compared with pH and ionic strength, solid–liquid ratio and coexisting ions (Cu2+, CrO42−) had more significant influence over the adsorption performance. The findings provide guidance for application of KOH-activated graphene as a promising alternative adsorbent for antibiotics removal from aqueous solutions. PMID:29291064
Nanoparticle interactions with co-existing contaminants: joint toxicity, bioaccumulation and risk.
Deng, Rui; Lin, Daohui; Zhu, Lizhong; Majumdar, Sanghamitra; White, Jason C; Gardea-Torresdey, Jorge L; Xing, Baoshan
2017-06-01
With their growing production and application, engineered nanoparticles (NPs) are increasingly discharged into the environment. The released NPs can potentially interact with pre-existing contaminants, leading to biological effects (bioaccumulation and/or toxicity) that are poorly understood. Most studies on NPs focus on single analyte exposure; the existing literature on joint toxicity of NPs and co-existing contaminants is rather limited but beginning to develop rapidly. This is the first review paper evaluating the current state of knowledge regarding the joint effects of NPs and co-contaminants. Here, we review: (1) methods for investigating and evaluating joint effects of NPs and co-contaminants; (2) simultaneous toxicities from NPs co-exposed with organic contaminants, metal/metalloid ions, dissolved organic matter (DOM), inorganic ligands and additional NPs; and (3) the influence of NPs co-exposure on the bioaccumulation of organic contaminants and heavy metal ions, as well as the influence of contaminants on NPs bioaccumulation. In addition, future research needs are discussed so as to better understand risk associated with NPs-contaminant co-exposure.
The coexistence of natural and supernatural explanations within and across domains and development.
Busch, Justin T A; Watson-Jones, Rachel E; Legare, Cristine H
2017-03-01
People across highly diverse cultural contexts use both natural and supernatural explanations to explain questions of fundamental concern such as death, illness, and human origins. The present study examines the development of explanatory coexistence within and across domains of existential concern in individuals in Tanna, Vanuatu. We examined three age groups: 7- to 12-year-old children, 13- to 18-year-old adolescents, and 19- to 70-year-old adults (N = 72). Within the domain of death, biological and spontaneous explanations were most common across all ages. For illness, children showed the highest rates of explanatory coexistence, while adolescents and adults favoured biological explanations. Within the human origins domain, theistic explanations were most common across the age groups. Overall, these data show that coexistence reasoning in these domains is pervasive across cultures, yet at the same time it is deeply contextually specific, reflecting the nuanced differences in local ecologies and cultural beliefs. Statement of contribution What is already known on this subject? Individuals across highly diverse cultural contexts use both natural and supernatural explanations to understand the events that occur in their lives. Context and cultural input play a large role in determining when and how individuals incorporate natural and supernatural explanations. The development of explanatory coexistence has primarily studied explanations for isolated domains. What does this study add? We examined explanatory coexistence in a culture with recent conversion to Christianity and formal education. The current research examines how individuals reason within and across the domains of human origins, illness, and death. Developmental differences associated with explanatory coexistence are examined. © 2016 The British Psychological Society.
USDA-ARS?s Scientific Manuscript database
Herbivore induced plant volatiles (HIPVs) serve as specific cues to higher trophic levels. Novel, exotic herbivores entering foodwebs with a common co-existence history may disrupt the native infochemical network due to changes in HIPV profiles. Here we analyzed HIPV blends of native Brassica rapa p...
Benedicte Bachelot; María Uriarte; Krista L. McGuire; Jill Thompson; Jess Zimmerman
2017-01-01
Negative population feedbacks mediated by natural enemies can promote species coexistence at the community scale through disproportionate mortality of numerically dominant (common) tree species. Simultaneously, associations with arbuscular mycorrhizal fungi (AMF) can result in positive effects on tree populations. Coupling data on seedling foliar damage from herbivores...
[Coexistence of Addison-Biermer's disease with autoimmune thyroiditis - case report].
Lacka, Katarzyna; Maciejewski, Adam; Florczak-Wyspiańska, Jolanta
2013-01-01
Addison-Biermer's anaemia is an autoimmune disease and the most common cause of vitamin B12 deficiency. Hashimoto disease is the most common type of the thyroiditis and also has autoimmunological origin. Frequent coexistence of both mentioned entities has been observed. In the paper we report a case of a woman, who was diagnosed with pernicious anaemia (PA) with predominant neurological symptoms and concomitant autoimmune thyroiditis. Many efforts have been made in order to explain frequent coexistence of mentioned diseases. Both genetic (mainly HLA region genes) and environmental (mostly bacterial infections) factors are considered. The aim of the study (was to emphasize significance of diagnosing thyroid gland diseases among PA patients. It is also important to remember that neurological symptoms are frequent in the course of PA and may precede other complaints. However it should not prevent the right diagnosis.
NASA Astrophysics Data System (ADS)
Ghebache, Siham; Tribeche, Mouloud
2017-10-01
The problem of arbitrary amplitude ion-acoustic solitary waves (IASWs), which accompany electronegative plasmas having positive ions, negative ions, and nonextensive electrons is addressed. The energy integral equation with a new Sagdeev potential is analyzed to examine the existence regions of the IASWs. Different types of electronegative plasmas inspired from the experimental studies of Ichiki et al. (2001) are discussed. Our results show that in such plasmas IASWs, the amplitude and nature of which depend sensitively on the mass and density ratio of the positive and negative ions as well as the q-nonextensive parameter, can exist. Interestingly, one finds that our plasma model supports the coexistence of smooth rarefactive and spiky compressive IASWs. Our results complement and provide new insights on previously published findings on this problem.
Fu, Xiuli; Lou, Tingting; Chen, Zhaopeng; Lin, Meng; Feng, Weiwei; Chen, Lingxin
2012-02-01
A novel platform for effective "turn-on" fluorescence sensing of lead ions (Pb(2+)) in aqueous solution was developed based on gold nanoparticle (AuNP)-functionalized graphene. The AuNP-functionalized graphene exhibited minimal background fluorescence because of the extraordinarily high quenching ability of AuNPs. Interestingly, the AuNP-functionalized graphene underwent fluorescence restoration as well as significant enhancement upon adding Pb(2+), which was attributed to the fact that Pb(2+) could accelerate the leaching rate of the AuNPs on graphene surfaces in the presence of both thiosulfate (S(2)O(3)(2-)) and 2-mercaptoethanol (2-ME). Consequently, this could be utilized as the basis for selective detection of Pb(2+). With the optimum conditions chosen, the relative fluorescence intensity showed good linearity versus logarithm concentration of Pb(2+) in the range of 50-1000 nM (R = 0.9982), and a detection limit of 10 nM. High selectivity over common coexistent metal ions was also demonstrated. The practical application had been carried out for determination of Pb(2+) in tap water and mineral water samples. The Pb(2+)-specific "turn-on" fluorescence sensor, based on Pb(2+) accelerated leaching of AuNPs on the surface of graphene, provided new opportunities for highly sensitive and selective Pb(2+) detection in aqueous media.
Gao, Ru; Hu, Zheng; Chang, Xijun; He, Qun; Zhang, Lijun; Tu, Zhifeng; Shi, Jianping
2009-12-15
A new sorbent 1-acylthiosemicarbazide-modified activated carbon (AC-ATSC) was prepared as a solid-phase extractant and applied for removing of trace Cu(II), Hg(II) and Pb(II) prior to their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The separation/preconcentration conditions of analytes were investigated, including effects of pH, the shaking time, the sample flow rate and volume, the elution condition and the interfering ions. At pH 3, the maximum static adsorption capacity of Cu(II), Hg(II) and Pb(II) onto the AC-ATSC were 78.20, 67.80 and 48.56 mg g(-1), respectively. The adsorbed metal ions were quantitatively eluted by 3.0 mL of 2% CS(NH2)2 and 2.0 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation. According to the definition of IUPAC, the detection limits (3sigma) of this method for Cu(II), Hg(II) and Pb(II) were 0.20, 0.12 and 0.45 ng mL(-1), respectively. The relative standard deviation under optimum conditions is less than 4.0% (n=8). The prepared sorbent was applied for the preconcentration of trace Cu(II), Hg(II) and Pb(II) in certified and water samples with satisfactory results.
Coupled modes in magnetized dense plasma with relativistic-degenerate electrons
NASA Astrophysics Data System (ADS)
Khan, S. A.
2012-01-01
Low frequency electrostatic and electromagnetic waves are investigated in ultra-dense quantum magnetoplasma with relativistic-degenerate electron and non-degenerate ion fluids. The dispersion relation is derived for mobile as well as immobile ions by employing hydrodynamic equations for such plasma under the influence of electromagnetic forces and pressure gradient of relativistic-degenerate Fermi gas of electrons. The result shows the coexistence of shear Alfven and ion modes with relativistically modified dispersive properties. The relevance of results to the dense degenerate plasmas of astrophysical origin (for instance, white dwarf stars) is pointed out with brief discussion on ultra-relativistic and non-relativistic limits.
Positive Ion Induced Solidification of He4
NASA Astrophysics Data System (ADS)
Moroshkin, P.; Lebedev, V.; Weis, A.
2009-03-01
We have observed bulk solidification of He4 induced by nucleation on positive alkali ions in pressurized superfluid helium. The ions are extracted into the liquid from alkali-doped solid He by a static electric field. The experiments prove the existence of charged particles in a solid structure composed of doped He that was recently shown to coexist with superfluid helium below the He solidification pressure. This supports our earlier suggestion that the Coulomb interaction of positive ions surrounded by a solid He shell (snowballs) and electrons trapped in spherical cavities (electron bubbles), together with surface tension, is responsible for the stability of that structure against melting. We have determined the density of charges in the sample by two independent methods.
Electrochemical sensor for rutin detection based on Au nanoparticle-loaded helical carbon nanotubes
NASA Astrophysics Data System (ADS)
Yang, Haitang; Li, Bingyue; Cui, Rongjing; Xing, Ruimin; Liu, Shanhu
2017-10-01
The key step in the fabrication of highly active electrochemical sensors is seeking multifunctional nanocomposites as electrode modified materials. In this study, the gold nanoparticle-decorated helical carbon nanotube nanocomposites (AuNPs-HCNTs) were fabricated for rutin detection because of its superior sensitivity, the chemical stability of AuNPs, and the superior conductivity and unique 3D-helical structure of helical carbon nanotubes. Results showed the prepared nanocomposites exhibited superior electrocatalytic activity towards rutin due to the synergetic effects of AuNPs and HCNTs. Under the optimized conditions, the developed sensor exhibited a linear response range from 0.1 to 31 μmol/L for rutin with a low detectable limit of 81 nmol/L. The proposed method might offer a possibility for electrochemical analysis of rutin in Chinese medical analysis or serum monitoring owing to its low cost, simplicity, high sensitivity, good stability, and few interferences against common coexisting ions in real samples.
Holt, Galen; Chesson, Peter
2014-03-01
Temporal environmental variation is a leading hypothesis for the coexistence of desert annual plants. Environmental variation is hypothesized to cause species-specific patterns of variation in germination, which then generates the storage effect coexistence mechanism. However, it has never been shown how sufficient species differences in germination patterns for multispecies coexistence can arise from a shared fluctuating environment. Here we show that nonlinear germination responses to a single fluctuating physical environmental factor can lead to sufficient differences between species in germination pattern for the storage effect to yield coexistence of multiple species. We derive these nonlinear germination responses from experimental data on the effects of varying soil moisture duration. Although these nonlinearities lead to strong species asymmetries in germination patterns, the relative nonlinearity coexistence mechanism is minor compared with the storage effect. However, these asymmetries mean that the storage effect can be negative for some species, which then only persist in the face of interspecific competition through average fitness advantages. This work shows how a low dimensional physical environment can nevertheless stabilize multispecies coexistence when the species have different nonlinear responses to common conditions, as supported by our experimental data. Copyright © 2013 Elsevier Inc. All rights reserved.
Xu, Zhengming; Han, Dexia; Li, Yuan; Zhang, Pingling; You, Lijun; Zhao, Zhengang
2018-04-23
In this study, the FPA90-Cl resin was magnetized with supported Fe 3 O 4 particles using a chemical co-precipitation method and its removal performance of bromate and coexisting precursors was explored. The magnetized FPA90-Cl resin was structurally characterized by SEM, FT-IR, and XRD. The effects of the initial concentrations, temperature, and resin dosage on bromate and bromide ion removal in drinking water were investigated using batch experiments. The magnetized FPA90-Cl resin exhibited a high removal efficiency for bromate and bromide ions at three initial concentrations, and the residual bromate concentrations were under the maximum contaminant level (MCL) of 10 μg L -1 after 80 min. The adsorption data of bromate and bromide ion could be well described by a pseudo-first-order kinetic model (R 2 ˃ 0.98). The bromate removal alone was further studied by varying the initial solution pH, temperature, and competitive anions. The results showed that the magnetized FPA90-Cl resin could be used over a wide pH range (4.0-9.0). The maximum sorption capacity of the magnetized FPA90-Cl resin for bromate reached 132.83 mg g -1 at 298 K. The Freundlich and Redlich-Peterson isotherm models fit the bromate adsorption equilibrium better (R 2 ˃ 0.99) than the Langmuir isotherm model (R 2 ˃ 0.98). The thermodynamic analysis showed that the bromate adsorption process was endothermic. The negative ΔG and positive ΔS indicated that the process was spontaneous and that randomness increased after adsorption, respectively. The competition of coexisting anions with bromate was in the order of SO 4 2- > CO 3 2- > Cl - > NO 3 - > HCO 3 - > PO 4 3- . Additionally, the magnetized FPA90-Cl resin could maintain a high bromate and bromide ion adsorption capacity after five cycles of regeneration by a 0.1 M NaCl solution. Graphical abstract ᅟ.
NASA Astrophysics Data System (ADS)
Kleemann, W.; Shvartsman, V. V.; Borisov, P.; Kania, A.
2010-12-01
The coexistence of cluster glass with long-range antiferromagnetic order in the relaxor ferroelectric PbFe0.5Nb0.5O3 is elucidated. While the transition at TN=153K on the infinite antiferromagnetic cluster induces 3m symmetry with large EH2 magnetoelectric response, the disconnected subspace of isolated Fe3+ ions and finite clusters accommodates the cluster glass below Tg=10.6K with field-induced m' symmetry and EH-type magnetoelectric response. Critical slowing-down, memory and rejuvenation after aging, occurrence of a de Almeida-Thouless phase line, and stretched exponential relaxation of remanence corroborate the glass nature.
Spatial complementarity and the coexistence of species.
Velázquez, Jorge; Garrahan, Juan P; Eichhorn, Markus P
2014-01-01
Coexistence of apparently similar species remains an enduring paradox in ecology. Spatial structure has been predicted to enable coexistence even when population-level models predict competitive exclusion if it causes each species to limit its own population more than that of its competitor. Nevertheless, existing hypotheses conflict with regard to whether clustering favours or precludes coexistence. The spatial segregation hypothesis predicts that in clustered populations the frequency of intra-specific interactions will be increased, causing each species to be self-limiting. Alternatively, individuals of the same species might compete over greater distances, known as heteromyopia, breaking down clusters and opening space for a second species to invade. In this study we create an individual-based model in homogeneous two-dimensional space for two putative sessile species differing only in their demographic rates and the range and strength of their competitive interactions. We fully characterise the parameter space within which coexistence occurs beyond population-level predictions, thereby revealing a region of coexistence generated by a previously-unrecognised process which we term the triadic mechanism. Here coexistence occurs due to the ability of a second generation of offspring of the rarer species to escape competition from their ancestors. We diagnose the conditions under which each of three spatial coexistence mechanisms operates and their characteristic spatial signatures. Deriving insights from a novel metric - ecological pressure - we demonstrate that coexistence is not solely determined by features of the numerically-dominant species. This results in a common framework for predicting, given any pair of species and knowledge of the relevant parameters, whether they will coexist, the mechanism by which they will do so, and the resultant spatial pattern of the community. Spatial coexistence arises from complementary combinations of traits in each species rather than solely through self-limitation.
Spatial Complementarity and the Coexistence of Species
Velázquez, Jorge; Garrahan, Juan P.; Eichhorn, Markus P.
2014-01-01
Coexistence of apparently similar species remains an enduring paradox in ecology. Spatial structure has been predicted to enable coexistence even when population-level models predict competitive exclusion if it causes each species to limit its own population more than that of its competitor. Nevertheless, existing hypotheses conflict with regard to whether clustering favours or precludes coexistence. The spatial segregation hypothesis predicts that in clustered populations the frequency of intra-specific interactions will be increased, causing each species to be self-limiting. Alternatively, individuals of the same species might compete over greater distances, known as heteromyopia, breaking down clusters and opening space for a second species to invade. In this study we create an individual-based model in homogeneous two-dimensional space for two putative sessile species differing only in their demographic rates and the range and strength of their competitive interactions. We fully characterise the parameter space within which coexistence occurs beyond population-level predictions, thereby revealing a region of coexistence generated by a previously-unrecognised process which we term the triadic mechanism. Here coexistence occurs due to the ability of a second generation of offspring of the rarer species to escape competition from their ancestors. We diagnose the conditions under which each of three spatial coexistence mechanisms operates and their characteristic spatial signatures. Deriving insights from a novel metric — ecological pressure — we demonstrate that coexistence is not solely determined by features of the numerically-dominant species. This results in a common framework for predicting, given any pair of species and knowledge of the relevant parameters, whether they will coexist, the mechanism by which they will do so, and the resultant spatial pattern of the community. Spatial coexistence arises from complementary combinations of traits in each species rather than solely through self-limitation. PMID:25532018
Coexistence of Malaria and Thalassemia in Malaria Endemic Areas of Thailand
Kuesap, Jiraporn; Chaijaroenkul, W.; Rungsihirunrat, K.; Pongjantharasatien, K.; Na-Bangchang, Kesara
2015-01-01
Hemoglobinopathy and malaria are commonly found worldwide particularly in malaria endemic areas. Thalassemia, the alteration of globin chain synthesis, has been reported to confer resistance against malaria. The prevalence of thalassemia was investigated in 101 malaria patients with Plasmodium falciparum and Plasmodium vivax along the Thai-Myanmar border to examine protective effect of thalassemia against severe malaria. Hemoglobin typing was performed using low pressure liquid chromatography (LPLC) and α-thalassemia was confirmed by multiplex PCR. Five types of thalassemia were observed in malaria patients. The 2 major types of thalassemia were Hb E (18.8%) and α-thalassemia-2 (11.9%). There was no association between thalassemia hemoglobinopathy and malaria parasitemia, an indicator of malaria disease severity. Thalassemia had no significant association with P. vivax infection, but the parasitemia in patients with coexistence of P. vivax and thalassemia was about 2-3 times lower than those with coexistence of P. falciparum and thalassemia and malaria without thalassemia. Furthermore, the parasitemia of P. vivax in patients with coexistence of Hb E showed lower value than coexistence with other types of thalassemia and malaria without coexistence. Parasitemia, hemoglobin, and hematocrit values in patients with coexistence of thalassemia other than Hb E were significantly lower than those without coexistence of thalassemia. Furthermore, parasitemia with coexistence of Hb E were 2 times lower than those with coexistence of thalassemia other than Hb E. In conclusion, the results may, at least in part, support the protective effect of thalassemia on the development of hyperparasitemia and severe anemia in malaria patients. PMID:26174819
Hadronic Correlations and Fluctuations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Koch, Volker
2008-10-09
We will provide a review of some of the physics which can be addressed by studying fluctuations and correlations in heavy ion collisions. We will discuss Lattice QCD results on fluctuations and correlations and will put them into context with observables which have been measured in heavy-ion collisions. Special attention will be given to the QCD critical point and the first order co-existence region, and we will discuss how the measurement of fluctuations and correlations can help in an experimental search for non-trivial structures in the QCD phase diagram.
Phase Equilibria of the Brine Systems Containing Strontium and Calcium Ions
NASA Astrophysics Data System (ADS)
Wang, Xia; Zhao, Kaiyu; Li, Long; Guo, Yafei; Meng, Lingzong; Deng, Tianlong
2017-12-01
It is well known that the comprehensive utilization of the Salt Lake resources successfully must be guided corresponding to the aqueous phase equilibria and phase diagrams. Researches on the phase relationships of brine systems containing calcium and strontium ions are essential to promote the development for the relative resources discovered in China at recent years. In this paper, the phase equilibria of calcium-containing systems, strontium-containing systems and calcium-strontium coexisted brine systems around the world were reviewed. The problems existed recently and new trends in future were point out.
Masadome, Takashi; Imato, Toshihiko
2003-07-04
A plasticized poly (vinyl chloride) (PVC) membrane electrode sensitive to stearyltrimethylammonium (STA) ion is applied to the determination of cationic polyelectrolytes such as poly (diallyldimethylammonium chloride) (Cat-floc) by potentiometric titration, using a potassium poly (vinyl sulfate) (PVSK) solution as a titrant. The end-point of the titration is detected as the potential change of the plasticized PVC membrane electrode caused by decrease in the concentration of STA ion added to the sample solution as a marker ion due to the ion association reaction between the STA ion and PVSK. The effects of the concentration of STA ion, coexisting electrolytes in the sample solution and pH of the sample on the degree of the potential change at the end-point were examined. A linear relationship between the concentration of cationic polyelectrolyte and the end-point volume of the titrant exists in the concentration range from 2x10(-5) to 4x10(-4) N for Cat-floc, glycol chitosan, and methylglycol chitosan.
Liu, Hui; Zhang, Baogang; Yuan, Heyang; Cheng, Yutong; Wang, Song; He, Zhen
2017-12-01
Vanadium (V) pollution in groundwater has posed serious risks to the environment and public health. Anaerobic microbial reduction can achieve efficient and cost-effective remediation of V(V) pollution, but its interactions with coexisting common electron acceptors such as NO 3 - , Fe 3+ , SO 4 2- and CO 2 in groundwater remain unknown. In this study, the interactions between V(V) reduction and reduction of common electron acceptors were examined with revealing relevant microbial community and identifying dominant species. The results showed that the presence of NO 3 - slowed down the removal of V(V) in the early stage of the reaction but eventually led to a similar reduction efficiency (90.0% ± 0.4% in 72-h operation) to that in the reactor without NO 3 - . The addition of Fe 3+ , SO 4 2- , or CO 2 decreased the efficiency of V(V) reduction. Furthermore, the microbial reduction of these coexisting electron acceptors was also adversely affected by the presence of V(V). The addition of V(V) as well as the extra dose of Fe 3+ , SO 4 2- and CO 2 decreased microbial diversity and evenness, whereas the reactor supplied with NO 3 - showed the increased diversity. High-throughput 16S rRNA gene pyrosequencing analysis indicated the accumulation of Geobacter, Longilinea, Syntrophobacter, Spirochaeta and Anaerolinea, which might be responsible for the reduction of multiple electron acceptors. The findings of this study have demonstrated the feasibility of anaerobic bioremediation of V(V) and the possible influence of coexisting electron acceptors commonly found in groundwater. Copyright © 2017 Elsevier Ltd. All rights reserved.
Xuan, Jian-yong; Luo, Zhong-yang; Zhao, Lei; Jiang, Jian-ping; Gao, Xiang
2012-05-01
The spectrum of excited N2 molecules and ions was measured by optical emission spectroscopy in pulsed corona discharge with a wire-to-plate reactor. The ratio of emission intensities emitted by the excited molecules and ions of N2 was compared with numerical simulation to determine average electron energies and electric field distributions. Within 2 cm distance from wire electrode in horizontal and vertical directions, electric field and average electron energies appear to be in the ranges of 11.05 19.6 MV x m(-1) and 10.10-13.92 eV respectively; as the distance increases, average electron energies and electric field show a similar trend: first decrease and then increase. Chemically active species, such as OH, O and O3, can be generated through the energetic electron collisions with H2O and O2 directly or indirectly. For the NO oxidation, there is no coexistence of NO and O3, whereas there is a coexistence of NO and OH. NO is oxidized by O3 or O more efficiently than by OH radical.
NASA Astrophysics Data System (ADS)
Tian, Fengling; Huang, Wei; Yang, Jidong; Li, Qin
In pH 3.25-3.35 Britton-Robinson (BR) buffer solution, albendazole (ABZ) could react with eosin Y (EY) to form a 1:1 ion-association complex, which not only results in the quenching of fluorescence, but also resulted in the great enhancement of resonance Rayleigh scattering (RRS) and frequency doubling scattering (FDS). Furthermore, a new RRS spectrum will appear, and the maximum RRS wavelength was located at about 356 nm. The detection limit for ABZ were 21.51 ng mL-1 for the fluorophotometry, 6.93 ng mL-1 for the RRS method and 12.89 ng mL-1 for the FDS method. Among them, the RRS method had the highest sensitivity. The experimental conditions were optimized and effects of coexisting substances were evaluated. Meanwhile, the influences of coexisting substances were tested. The methods have been successfully applied to the determination of ABZ in capsules and human urine samples. The composition and structure of the ion-association complex and the reaction mechanism were discussed.
NASA Astrophysics Data System (ADS)
Božin, E. S.; Knox, K. R.; Juhás, P.; Hor, Y. S.; Mitchell, J. F.; Billinge, S. J. L.
2014-02-01
Increasingly, nanoscale phase coexistence and hidden broken symmetry states are being found in the vicinity of metal-insulator transitions (MIT), for example, in high temperature superconductors, heavy fermion and colossal magnetoresistive materials, but their importance and possible role in the MIT and related emergent behaviors is not understood. Despite their ubiquity, they are hard to study because they produce weak diffuse signals in most measurements. Here we propose Cu(Ir1 - xCrx)2S4 as a model system, where robust local structural signals lead to key new insights. We demonstrate a hitherto unobserved coexistence of an Ir4+ charge-localized dimer phase and Cr-ferromagnetism. The resulting phase diagram that takes into account the short range dimer order is highly reminiscent of a generic MIT phase diagram similar to the cuprates. We suggest that the presence of quenched strain from dopant ions acts as an arbiter deciding between the competing ground states.
Conventional magnetic superconductors
Wolowiec, C. T.; White, B. D.; Maple, M. B.
2015-07-01
We discuss several classes of conventional magnetic superconductors including the ternary rhodium borides and molybdenum chalcogenides (or Chevrel phases), and the quaternary nickel-borocarbides. These materials exhibit some exotic phenomena related to the interplay between superconductivity and long-range magnetic order including: the coexistence of superconductivity and antiferromagnetic order; reentrant and double reentrant superconductivity, magnetic field induced superconductivity, and the formation of a sinusoidally-modulated magnetic state that coexists with superconductivity. We introduce the article with a discussion of the binary and pseudobinary superconducting materials containing magnetic impurities which at best exhibit short-range “glassy” magnetic order. Early experiments on these materials led tomore » the idea of a magnetic exchange interaction between the localized spins of magnetic impurity ions and the spins of the conduction electrons which plays an important role in understanding conventional magnetic superconductors. Furthermore, these advances provide a natural foundation for investigating unconventional superconductivity in heavy-fermion compounds, cuprates, and other classes of materials in which superconductivity coexists with, or is in proximity to, a magnetically-ordered phase.« less
Bougea, A; Constantinides, V; Anagnostou, E; Kararizou, E
2015-01-01
The "other primary headaches" encompasses a group of uncommon but distinct headache disorders. The coexistence of their subforms such as primary sexual and exercise headache is not a new phenomenon, but in association with cough headache is rather uncommon. Report of cases: We report three cases with a rare coexistence of primary cough, exercise and associated with sexual activity headache. Indomethacin was effective in all patients. The leading pathophysiological explanation involves a rapid rise in intra-abdominal pressure exertional factors or an inappropriate reaction in the cerebral vasculature. Further studies are needed to confirm a common pathogenic mechanism in these patients. Τhe coexistence of these headaches needs to be taken into account in the final classification that is expected to be available in 2016. Hippokratia 2015; 19 (4): 369-371.
Zhang, Hui-Min; Fan, Zheng; Xu, Wei; Feng, Xiao; Wu, Zu-Cheng
2017-09-15
The recovery of heavy metals from aqueous solutions or e-wastes is of upmost importance. Retrieval of Au, Ag, and Cu with electricity generation through building an ethanol-metal coupled redox fuel cells (CRFCs) is demonstrated. The cell was uniquely assembled on PdNi/C anode the electro-oxidation of ethanol takes place to give electrons and then go through the external circuit reducing metal ions to metallic on the cathode, metals are recovered. Taking an example of removal of 100mgL -1 gold in 0.5M HAc-NaAc buffer solution as the catholyte, 2.0M ethanol in 1.0M alkaline solution as the anolyte, an open circuit voltage of 1.4V, more than 96% of gold removal efficiency in 20h, and equivalent energy production of 2.0kWhkg -1 of gold can be readily achieved in this system. When gold and copper ions coexist, it was confirmed that metallic Cu is formed on the cathodic electrode later than metallic Au formation by XPS analysis. Thus, this system can achieve step by step electrodeposition of gold and copper while the two metal ions coexisting. This work develops a new approach to retrieve valuable metals from aqueous solution or e-wastes. Copyright © 2017 Elsevier B.V. All rights reserved.
Climate variability has a stabilizing effect on the coexistence of prairie grasses
Adler, Peter B.; HilleRisLambers, Janneke; Kyriakidis, Phaedon C.; Guan, Qingfeng; Levine, Jonathan M.
2006-01-01
How expected increases in climate variability will affect species diversity depends on the role of such variability in regulating the coexistence of competing species. Despite theory linking temporal environmental fluctuations with the maintenance of diversity, the importance of climate variability for stabilizing coexistence remains unknown because of a lack of appropriate long-term observations. Here, we analyze three decades of demographic data from a Kansas prairie to demonstrate that interannual climate variability promotes the coexistence of three common grass species. Specifically, we show that (i) the dynamics of the three species satisfy all requirements of “storage effect” theory based on recruitment variability with overlapping generations, (ii) climate variables are correlated with interannual variation in species performance, and (iii) temporal variability increases low-density growth rates, buffering these species against competitive exclusion. Given that environmental fluctuations are ubiquitous in natural systems, our results suggest that coexistence based on the storage effect may be underappreciated and could provide an important alternative to recent neutral theories of diversity. Field evidence for positive effects of variability on coexistence also emphasizes the need to consider changes in both climate means and variances when forecasting the effects of global change on species diversity. PMID:16908862
A patient with coexisting narcolepsy and morbid jealousy showing favourable response to fluoxetine.
Wing, Y. K.; Lee, S.; Chiu, H. F.; Ho, C. K.; Chen, C. N.
1994-01-01
A 37 year old Chinese man suffered from coexisting narcolepsy and morbid jealousy which were precipitated by head injury 5 years previously. Fluoxetine 20 mg/day reduced his narcoleptic symptoms and morbid jealousy but not his sleepiness. On defaulting treatment, the patient's symptoms and marital problem recurred. A common central serotonin disturbance might be involved in mediating the sleep disorder and associated psychopathology. PMID:8140016
Palta, Anshu; Garg, Shailja; Chauhan, Sandeep; Varma, Neelam
2011-03-01
Coexistence of chronic lymphocytic leukemia (CLL) with myelofibrosis is a rare association with only isolated case reports in the literature. We report an unusual case of CLL in which the cause of anemia was coexistent myelofibrosis. In a case of CLL presenting with refractory anemia, besides common causes like autoimmune hemolytic anemia and marrow infiltration, other causes like myelofibrosis should be searched for.
Ghosh, Ujjayini; Yau, Wai-Ming; Tycko, Robert
2018-05-15
Fibrils formed by 40- and 42-residue amyloid-β (Aβ40 and Aβ42) peptides exhibit molecular-level structural polymorphisms. A recent screen of fibrils derived from brain tissue of Alzheimer's disease patients revealed a single predominant Aβ40 polymorph. We present solid state nuclear magnetic resonance (ssNMR) data that define its coexisting structurally ordered and disordered segments.
Effects of dispersible MoS2 nanosheets and Nano-silver coexistence on the metabolome of yeast.
Yang, Qi; Zhang, Lei; Ben, Ailing; Wu, Na; Yi, Yanliang; Jiang, Ling; Huang, He; Yu, Yadong
2018-05-01
As a new rising star in the post-graphene two-dimensional materials (2DMs), molybdenum disulfide (MoS 2 ) attracts increasing attentions and is widely applied. However, the chemical and toxicological interaction between MoS 2 and other co-contaminants is still poorly understood. Nano-silver (N-Ag) is the most commonly used nanomaterial in commercial products and distributed widely in the environment. Herein, we investigated the effects of chitosan functionalized MoS 2 (CS-MoS 2 ) nanosheets, a water-dispersible form of MoS 2 , on the microbial toxicity of N-Ag. We found that the incorporation of CS-MoS 2 nanosheets attenuated the oxidative stress induced by N-Ag on yeast cells, while caused more membrane stress. In addition, the inhibition of N-Ag on the metabolic activities of yeast cells could be attenuated by CS-MoS 2 nanosheets as well. The coexistence of N-Ag and CS-MoS 2 nanosheets mainly perturbed the amino acid-related metabolic pathways in yeast cells, and phosphoric acid was a potential nanotoxicity biomarker. We further found that CS-MoS 2 nanosheets dramatically absorbed the Ag ion released from N-Ag, which might be responsible for its attenuation effect on the microbial toxicity of N-Ag. Our findings provide more new insights for the ecotoxicity evaluation of MoS 2 and other 2DMs. Copyright © 2018 Elsevier Ltd. All rights reserved.
Jin, Yulong; Huang, Yanyan; Liu, Guoquan; Zhao, Rui
2013-09-21
A novel quartz crystal microbalance (QCM) sensor for rapid, highly selective and sensitive detection of copper ions was developed. As a signal amplifier, gold nanoparticles (Au NPs) were self-assembled onto the surface of the sensor. A simple dip-and-dry method enabled the whole detection procedure to be accomplished within 20 min. High selectivity of the sensor towards copper ions is demonstrated by both individual and coexisting assays with interference ions. This gold nanoparticle mediated amplification allowed a detection limit down to 3.1 μM. Together with good repeatability and regeneration, the QCM sensor was also applied to the analysis of copper contamination in drinking water. This work provides a flexible method for fabricating QCM sensors for the analysis of important small molecules in environmental and biological samples.
Correlations and Fluctuations: Status and Perspectives
DOE Office of Scientific and Technical Information (OSTI.GOV)
Koch, Volker; Koch, Volker
2008-04-15
We will provide an overview of the physics which can be addressed by studying fluctuations and correlations in heavy ion collisions. Observables, which have been discussed in the literature will be briefly reviewed and put in context with experiment and information from Lattice QCD. Special attention will be given to the QCD critical point and the first order co-existence region.
Degradation of florfenicol in water by UV/Na2S 2O 8 process.
Gao, Yu-Qiong; Gao, Nai-Yun; Deng, Yang; Yin, Da-Qiang; Zhang, Yan-Sen
2015-06-01
UV irradiation-activated sodium persulfate (UV/PS) was studied to degrade florfenicol (FLO), a phenicol antibiotic commonly used in aquaculture, in water. Compared with UV/H2O2 process, UV/PS process achieves a higher FLO degradation efficiency, greater mineralization, and less cost. The quantum yield for direct photolysis of FLO and the second-order rate constant of FLO with sulfate radicals were determined. The effects of various factors, namely PS concentration, anions (NO3 (-), Cl(-), and HCO3 (-)), ferrous ion, and humic acid (HA), on FLO degradation were investigated. The results showed that the pseudo-first-order rate constant increased linearly with increased PS concentration. The tested anions all adversely affected FLO degradation performance with the order of HCO3 (-) > Cl(-) > NO3 (-). Coexisting ferrous ions enhanced FLO degradation at a Fe(2+)/PS molar ratio under 1:1. HA significantly inhibited FLO degradation due to radical scavenging and light-screening effect. Toxicity assessment showed that it is capable of controlling the toxicity for FLO degradation. These findings indicated that UV/PS is a promising technology for water polluted by antibiotics, and the treatment is optimized only after the impacts of water characteristics are carefully considered.
Liu, Yong; Zhang, Le; Zhou, Jin-Yong; Pan, Jinshun; Hu, Wei; Zhou, Yi-Hua
2016-01-01
Coexistence of hepatitis B surface antigen (HBsAg) and antibody against HBsAg (anti-HBs) comprises an atypical serological profile in patients with chronic hepatitis B virus (HBV) infection. In this study, in total 94 patients with coexisting HBsAg and anti-HBs and 94 age- and sex-matched patients with positive HBsAg were characterized by quantitatively measuring HBsAg and HBV DNA, sequencing large S genes, and observing clinical features. Compared with common hepatitis B patients, the patients with coexisting HBsAg and anti-HBs had lower HBsAg and HBV DNA levels. These two groups had similar rate of pre-S deletion mutations. However, in patients with coexisting HBsAg and anti-HBs, more amino acid substitutions in the a determinant of S gene were observed in HBV genotype C, but not in genotype B. Fourteen patients with coexisting HBsAg and anti-HBs were followed up for an average of 15.5 months. There were no significant changes in the levels of HBsAg, anti-HBs, HBV DNA and ALT over the follow-up period. Compared with the baseline sequences, amino acid substitutions in the MHR of HBsAg occurred in 14.3% (2/14) patients. In conclusion, coexistence of HBsAg and anti-HBs may be associated with higher frequency of mutations in the a determinant of HBV genotype C.
Large-bodied Demodex mite infestation in 4 dogs.
Hillier, Andrew; Desch, Clifford E
2002-03-01
Large-bodied Demodex mites were detected in 4 dogs. The mites were readily detected in material obtained via deep skin scrapings and were most commonly found on the trunk. The mites were distinguishable from D. canis, because adult males were approximately 100% longer and adult females were approximately 50% longer than adult male and female D. canis mites, respectively. The large-bodied mites were found in the hair follicles, sebaceous ducts, and sebaceous glands in histologic sections of skin from 2 dogs. All dogs had adult-onset generalized demodicosis. Two dogs had coexistent iatrogenic hypercortisolism, 1 dog had hypothyroidism, and 1 dog did not have coexistent disease. Infestations responded to miticidal therapy, control of the coexistent disease, or both.
Lighting up micromotors with quantum dots for smart chemical sensing.
Jurado-Sánchez, B; Escarpa, A; Wang, J
2015-09-25
A new "on-the-fly" chemical optical detection strategy based on the incorporation of fluorescence CdTe quantum dots (QDs) on the surface of self-propelled tubular micromotors is presented. The motion-accelerated binding of trace Hg to the QDs selectively quenches the fluorescence emission and leads to an effective discrimination between different mercury species and other co-existing ions.
On the Dynamical Regimes of Pattern-Accelerated Electroconvection.
Davidson, Scott M; Wessling, Matthias; Mani, Ali
2016-03-03
Recent research has established that electroconvection can enhance ion transport at polarized surfaces such as membranes and electrodes where it would otherwise be limited by diffusion. The onset of such overlimiting transport can be influenced by the surface topology of the ion selective membranes as well as inhomogeneities in their electrochemical properties. However, there is little knowledge regarding the mechanisms through which these surface variations promote transport. We use high-resolution direct numerical simulations to develop a comprehensive analysis of electroconvective flows generated by geometric patterns of impermeable stripes and investigate their potential to regularize electrokinetic instabilities. Counterintuitively, we find that reducing the permeable area of an ion exchange membrane, with appropriate patterning, increases the overall ion transport rate by up to 80%. In addition, we present analysis of nonpatterned membranes, and find a novel regime of electroconvection where a multivalued current is possible due to the coexistence of multiple convective states.
Geriatric Syndromes in Hospitalized Older Adults Discharged to Skilled Nursing Facilities
Bell, Susan P.; Vasilevskis, Eduard E.; Saraf, Avantika A.; Jacobsen, J. Mary Lou; Kripalani, Sunil; Mixon, Amanda S.; Schnelle, John F.; Simmons, Sandra F.
2016-01-01
Background Geriatric syndromes are common in older adults and associated with adverse outcomes. The prevalence, recognition, co-occurrence and recent onset of geriatric syndromes in patients transferred from hospital to skilled nursing facilities (SNFs) are largely unknown. Design Quality improvement project. Setting Acute care academic medical center and 23 regional partner SNFs. Participants 686 Medicare beneficiaries hospitalized between January 2013 and April 2014 and referred to SNFs. Measurements Nine geriatric syndromes were measured by project staff -- weight loss, decreased appetite, incontinence and pain (standardized interview), depression (Geriatric Depression Scale), delirium (Brief-Confusion Assessment Method), cognitive impairment (Brief Interview for Mental Status), falls and pressure ulcers (hospital medical record utilizing hospital-implemented screening tools). Estimated prevalence, new-onset prevalence and common coexisting clusters were determined. The extent that syndromes were commonly recognized by treating physicians and communicated to SNFs in hospital discharge documentation was evaluated. Results Geriatric syndromes were prevalent in more than 90% of hospitalized adults referred to SNFs; 55% met criteria for 3 or more co-existing syndromes. Overall the most prevalent syndromes were falls (39%), incontinence (39%), decreased appetite (37%) and weight loss (33%). Of individuals that met criteria for 3 or more syndromes, the most common triad clusters included nutritional syndromes (weight loss, loss of appetite), incontinence and depression. Treating hospital physicians commonly did not recognize and document geriatric syndromes in discharge summaries, missing 33–95% of syndromes present as assessed by research personnel. Conclusion Geriatric syndromes in hospitalized older adults transferred to SNF are prevalent and commonly co-exist with the most frequent clusters including nutritional syndromes, depression and incontinence. Despite the high prevalence, this clinical information is rarely communicated to the SNF on discharge. PMID:27059831
Solis, Francisco J.; Vernon, Brent
2009-01-01
Doping of thermoreversible polymer gels with charged monomers provides a way to control phase separation and gelation conditions by coupling the properties of the gel with a tunable ionic environment. We analyze the dependence of the gelation and phase separation conditions on the amount of salt present using a mean field model of weakly charged associative polymers. The ions and co-ions present are explicitly considered at the mean field level, and we determine their concentrations in the different equilibrium phases when the system undergoes phase separation. For weak polymer charge, the entropic contributions of the ions to the free energy of the system play a central role in the determination of the location of phase equilibrium. In the simplest case, when the associative interaction responsible for gel formation is independent of the electrostatic interaction, the addition of salt changes the polymer equilibrium concentrations and indirectly changes the measurable swelling of the gel. We construct phase diagrams of these systems showing the location of the coexistence region, the gel-sol boundary and the location of the tie-lines. We determine the swelling of the gel within the co-existence region. Our main result is that the description of the effect of the salt on the properties of the weakly charged gel can be described through an extra contribution to the effective immiscibility parameter χ proportional to the square of the doping degree f2 and to the inverse square of the added salt concentration s−2. PMID:19759854
Identification of carbohydrate anomers using ion mobility-mass spectrometry.
Hofmann, J; Hahm, H S; Seeberger, P H; Pagel, K
2015-10-08
Carbohydrates are ubiquitous biological polymers that are important in a broad range of biological processes. However, owing to their branched structures and the presence of stereogenic centres at each glycosidic linkage between monomers, carbohydrates are harder to characterize than are peptides and oligonucleotides. Methods such as nuclear magnetic resonance spectroscopy can be used to characterize glycosidic linkages, but this technique requires milligram amounts of material and cannot detect small amounts of coexisting isomers. Mass spectrometry, on the other hand, can provide information on carbohydrate composition and connectivity for even small amounts of sample, but it cannot be used to distinguish between stereoisomers. Here, we demonstrate that ion mobility-mass spectrometry--a method that separates molecules according to their mass, charge, size, and shape--can unambiguously identify carbohydrate linkage-isomers and stereoisomers. We analysed six synthetic carbohydrate isomers that differ in composition, connectivity, or configuration. Our data show that coexisting carbohydrate isomers can be identified, and relative concentrations of the minor isomer as low as 0.1 per cent can be detected. In addition, the analysis is rapid, and requires no derivatization and only small amounts of sample. These results indicate that ion mobility-mass spectrometry is an effective tool for the analysis of complex carbohydrates. This method could have an impact on the field of carbohydrate synthesis similar to that of the advent of high-performance liquid chromatography on the field of peptide assembly in the late 1970s.
NASA Astrophysics Data System (ADS)
Gao, Qianhong; Hua, Jiangtao; Li, Rong; Xing, Zhe; Pang, Lijuan; Zhang, Mingxing; Xu, Lu; Wu, Guozhong
2017-01-01
A novel fibrous adsorbent containing amine and quaternary ammonium groups was prepared by radiation-induced graft of glycidyl methacrylate (GMA) onto ultra-high molecular weight polyethylene (UHMWPE) fiber and further modifying with triethylenetetramine (TETA) and glycidyl trimethylammonium chloride (GTA). The ATR-IR spectra and SEM observation demonstrated that amine and quaternary ammonium groups were immobilized onto the surface of UHMWPE fiber. The principal factors affecting the adsorption of Cr(VI) ions have been investigated including pH of the aqueous solution, contact time, temperature and coexisting anions. This novel fibrous adsorbent could effectively adsorb Cr(VI) in the range of pH 1-9, and the maximum adsorption capacity reached 295 mg/g at pH 3 and 25 °C based on the Langmuir isotherm. It was found that adsorption equilibrium could be achieved within 2 h for initial Cr(VI) of 100 mg/L, following the pseudo-second order model. The effect of coexisting anions (including SO42-, H2PO4-, NO3-and Cl-) on the uptake of Cr(VI) was investigated in detail. Additionally, the adsorption saturated fiber could be regenerated by soaking in 0.5 mol/L NaOH solution, and the adsorption performance of this adsorbent could be maintained at 90% after eight cycles of adsorption-desorption. ATR-IR and XPS analysis revealed that Cr(VI) ions were adsorbed on the fiber adsorbent through ion exchange mechanism.
Identification of carbohydrate anomers using ion mobility-mass spectrometry
NASA Astrophysics Data System (ADS)
Hofmann, J.; Hahm, H. S.; Seeberger, P. H.; Pagel, K.
2015-10-01
Carbohydrates are ubiquitous biological polymers that are important in a broad range of biological processes. However, owing to their branched structures and the presence of stereogenic centres at each glycosidic linkage between monomers, carbohydrates are harder to characterize than are peptides and oligonucleotides. Methods such as nuclear magnetic resonance spectroscopy can be used to characterize glycosidic linkages, but this technique requires milligram amounts of material and cannot detect small amounts of coexisting isomers. Mass spectrometry, on the other hand, can provide information on carbohydrate composition and connectivity for even small amounts of sample, but it cannot be used to distinguish between stereoisomers. Here, we demonstrate that ion mobility-mass spectrometry--a method that separates molecules according to their mass, charge, size, and shape--can unambiguously identify carbohydrate linkage-isomers and stereoisomers. We analysed six synthetic carbohydrate isomers that differ in composition, connectivity, or configuration. Our data show that coexisting carbohydrate isomers can be identified, and relative concentrations of the minor isomer as low as 0.1 per cent can be detected. In addition, the analysis is rapid, and requires no derivatization and only small amounts of sample. These results indicate that ion mobility-mass spectrometry is an effective tool for the analysis of complex carbohydrates. This method could have an impact on the field of carbohydrate synthesis similar to that of the advent of high-performance liquid chromatography on the field of peptide assembly in the late 1970s.
Nuclear ``pasta'' phase within density dependent hadronic models
NASA Astrophysics Data System (ADS)
Avancini, S. S.; Brito, L.; Marinelli, J. R.; Menezes, D. P.; de Moraes, M. M. W.; Providência, C.; Santos, A. M.
2009-03-01
In the present paper, we investigate the onset of the “pasta” phase with different parametrizations of the density dependent hadronic model and compare the results with one of the usual parametrizations of the nonlinear Walecka model. The influence of the scalar-isovector virtual δ meson is shown. At zero temperature, two different methods are used, one based on coexistent phases and the other on the Thomas-Fermi approximation. At finite temperature, only the coexistence phases method is used. npe matter with fixed proton fractions and in β equilibrium are studied. We compare our results with restrictions imposed on the values of the density and pressure at the inner edge of the crust, obtained from observations of the Vela pulsar and recent isospin diffusion data from heavy-ion reactions, and with predictions from spinodal calculations.
SPARTALIS, ELEFTHERIOS; GARMPIS, NIKOLAOS; SPARTALIS, MICHAEL; DAMASKOS, CHRISTOS; MORIS, DEMETRIOS; ATHANASIOU, ANTONIOS; GKOLFAKIS, PARASKEVAS; KORKOLOPOULOU, PENELOPE; DIMITROULIS, DIMITRIOS; MANTAS, DIMITRIOS
2018-01-01
Background/Aim: Adenocarcinoma is one of the most common malignant tumors of the small intestine complicating Crohn’s disease. However, the coexistence of both conditions with diverticulosis of small bowel in young age makes this coincidence rare and clinical diagnosis very difficult. Case Report: We report a case of a woman admitted to our Department with acute abdominal pain and fever. The surgical and histological investigation, revealed a rare coexistence that has never been mentioned in the published medical literature. Conclusion: Ileal diverticulosis is not frequent and often asymptomatic as well as adenocarcinoma of the small bowel. In this case, those diseases along with Crohn’s disease led the patient to acute symptoms. PMID:29275319
Uni-directional interaction and plant-pollinator-robber coexistence.
Wang, Yuanshi; DeAngelis, Donald L; Holland, J Nathaniel
2012-09-01
A mathematical model for the plant-pollinator-robber interaction is studied to understand the factors leading to the widespread occurrence and stability of such interactions. In the interaction, a flowering plant provides resource for its pollinator and the pollinator has both positive and negative effects on the plant. A nectar robber acts as a plant predator, consuming a common resource with the pollinator, but with a different functional response. Using dynamical systems theory, mechanisms of species coexistence are investigated to show how a robber could invade the plant-pollinator system and persist stably with the pollinator. In addition, circumstances are demonstrated in which the pollinator's positive and negative effects on the plant could determine the robber's invasibility and the three-species coexistence.
MAGNETIC BEHAVIOR OF IRON IONS IN THE P2O5·CaO GLASS MATRIX
NASA Astrophysics Data System (ADS)
ARDELEAN, I.; ANDRONACHE, C.; PǍŞCUŢǍ, P.
The temperature dependence of the magnetic susceptibility of xFe2O3·(100-x)-[P2O5·CaO] glasses with 0
NASA Astrophysics Data System (ADS)
Conde, L.; Domenech-Garret, J. L.; Donoso, J. M.; Damba, J.; Tierno, S. P.; Alamillo-Gamboa, E.; Castillo, M. A.
2017-12-01
The characteristics of supersonic ion beams from the alternative low power hybrid ion engine (ALPHIE) are discussed. This simple concept of a DC powered plasma accelerator that only needs one electron source for both neutral gas ionization and ion beam neutralization is also examined. The plasma production and space charge neutralization processes are thus coupled in this plasma thruster that has a total DC power consumption of below 450 W, and uses xenon or argon gas as a propellant. The operation parameters of the plasma engine are studied in the laboratory in connection with the ion energy distribution function obtained with a retarding-field energy analyzer. The ALPHIE plasma beam expansion produces a mesothermal plasma flow with two-peaked ion energy distribution functions composed of low and high speed ion groups. The characteristic drift velocities of the fast ion groups, in the range 36.6-43.5 Km/s, are controlled by the acceleration voltage. These supersonic speeds are higher than the typical ion sound velocities of the low energy ion group produced by the expansion of the plasma jet. The temperatures of the slow ion population lead to ion Debye lengths longer than the electron Debye lengths. Furthermore, the electron impact ionization can coexist with collisional ionization by fast ions downstream the grids. Finally, the performance characteristics and comparisons with other plasma accelerator schemes are also discussed.
Lung cancer and chronic obstructive pulmonary disease: From a clinical perspective
Dai, Jie; Yang, Ping; Cox, Angela; Jiang, Gening
2017-01-01
Chronic obstructive pulmonary disease (COPD) and lung cancer are devastating pulmonary diseases that commonly coexist and present a number of clinical challenges. COPD confers a higher risk for lung cancer development, but available chemopreventive measures remain rudimentary. Current studies have shown a marked benefit of cancer screening in the COPD population, although challenges remain, including the common underdiagnosis of COPD. COPD-associated lung cancer presents distinct clinical features. Treatment for lung cancer coexisting with COPD is challenging as COPD may increase postoperative morbidities and decrease survival. In this review, we outline current progress in the understanding of the clinical association between COPD and lung cancer, and suggest possible cancer prevention strategies in this patient population. PMID:28061470
Well-studied Cu-BTC still serves surprises: evidence for facile Cu2+/Cu+ interchange.
Szanyi, Janos; Daturi, Marco; Clet, Guillaume; Baer, Donald R; Peden, Charles H F
2012-04-07
Cu-BTC (also known as HKUST-1) is a well-characterized metal-organic framework material produced in an industrial scale and widely studied for a number of potential applications by the scientific community. The co-existence of Cu(+) and Cu(2+) entities has already been observed in this material, but the presence of Cu(+) ions was attributed to oxide impurities. The results presented here clearly demonstrate that Cu(+) ions can be present in high concentrations inside the hybrid structure. Furthermore, switching between the two copper oxidation states can be induced by redox treatments, using vacuum and/or reducing gases at different sample temperatures.
Well-studied Cu-BTC still serves surprises: evidence for facile Cu2+/Cu+ interchange
DOE Office of Scientific and Technical Information (OSTI.GOV)
Szanyi, Janos; Daturi, Marco; Clet, Guillame
2012-03-08
Cu-BTC (also known as HKUST-1) is a well-characterized Metal Organic Framework material produced in industrial scale and widely studied for a number of potential applications by the scientific community. The co-existence of Cu+ and Cu2+ entities has already been observed in this material, but the presence of Cu+ ions was attributed to oxide impurities. The results presented here clearly demonstrate that Cu+ ions can be present in high concentrations inside the hybrid structure. Furthermore, switching between the two copper oxidation states can be induced by redox treatments, using vacuum and/or reducing gases at different sample temperatures.
Field-aligned currents and ion convection at high altitudes
NASA Technical Reports Server (NTRS)
Burch, J. L.; Reiff, P. H.
1985-01-01
Hot plasma observations from Dynamics Explorer 1 have been used to investigate solar-wind ion injection, Birkeland currents, and plasma convection at altitudes above 2 earth-radii in the morning sector. The results of the study, along with the antiparallel merging hypothesis, have been used to construct a By-dependent global convection model. A significant element of the model is the coexistence of three types of convection cells (merging cells, viscous cells, and lobe cells). As the IMF direction varies, the model accounts for the changing roles of viscous and merging processes and makes testable predictions about several magnetospheric phenomena, including the newly-observed theta aurora in the polar cap.
Phase equilibria of H2SO4, HNO3, and HCl hydrates and the composition of polar stratospheric clouds
NASA Technical Reports Server (NTRS)
Wooldridge, Paul J.; Zhang, Renyi; Molina, Mario J.
1995-01-01
Thermodynamic properties and phase equilibria behavior for the hydrates and coexisting pairs of hydrates of common acids which exist in the stratosphere are assembled from new laboratory measurements and standard literature data. The analysis focuses upon solid-vapor and solid-solid-vapor equilibria at temperatures around 200 K and includes new calorimetric and vapor pressure data. Calculated partial pressures versus 1/T slopes for the hydrates and coexisting hydrates agree well with experimental data where available.
Phase Equilibria of H2SO4, HNO3, and HCl Hydrates and the Composition of Polar Stratospheric Clouds
NASA Technical Reports Server (NTRS)
Wooldridge, Paul J.; Zhang, Renyi; Molina, Mario J.
1995-01-01
Thermodynamic properties and phase equilibria behavior for the hydrates and coexisting pairs of hydrates of common acids which exist in the stratosphere are assembled from new laboratory measurements and standard literature data. The analysis focuses upon solid-vapor and solid-solid-vapor equilibria at temperatures around 200 K and includes new calorimetric and vapor pressure data. Calculated partial pressures versus 1/T slopes for the hydrates and coexisting hydrates agree well with experimental data where available.
The impact on the family of the co-existing conditions of children with autism spectrum disorder.
Petrou, Alexandra M; Soul, Abigail; Koshy, Beena; McConachie, Helen; Parr, Jeremy R
2018-05-01
We aimed to investigate whether the impact on families of children with Autism Spectrum Disorder (ASD) is associated with the number and/or type of emotional and behavioral co-existing conditions that parents/carers of children with ASD reported as occurring frequently. In addition, we examined whether there was a greater impact on families if their child was male, had lower levels of language, had more severe autism symptomatology, and whether impact was associated with the number and/or type of co-existing conditions. Families were recruited from large UK research databases. 420 parents/carers of children aged 3 years 2 months to 18 years 8 months completed the revised Impact on Family (IoF) Scale and reported on the frequency/rate of their child's co-existing conditions. Parents/carers reported higher mean IoF scores if their child: had a greater number of frequent co-existing conditions; had sleep problems; was only able to communicate physically; and had more severe autism symptomatology. The development and implementation of targeted treatment and management approaches are needed to reduce the impact of co-existing conditions on family life. Autism Res 2018, 11: 776-787. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. Autism Spectrum Disorder (ASD) is commonly associated with emotional and/or behavior conditions that affect family life. Parents/carers of children with ASD who: (a) reported a greater number of frequent co-existing conditions, (b) had sleep problems, (c) were only able to communicate physically, and (d) had more severe symptoms characteristic of autism, reported a greater burden/strain on the family. Treatment approaches to target co-existing conditions alongside characteristics of ASD are needed to reduce their impact on family life. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.
Comer, J.; Ortoleva, P.
2007-01-01
Coexistence of twisted and untwisted crystals is explained via a model that accounts for the coupling of the entropic and energetic effects of impurities and a supra-lattice-scale structural order parameter. It is shown that twisted impure crystals can be in equilibrium with untwisted purer ones. The model explains how coexistence can occur in agates and other systems under hydrostatic stress. The model implies that untwisted crystals grown under one set of conditions could undergo a phase separation that, when accompanied by an imposed compositional gradient, leads to commonly observed, alternating bands of twisted and untwisted crystals and, when occurring in the absence of an external gradient, mossy patterns of crystal texture can emerge. This phenomenon is not related to anisotropic applied stress. Rather coexistence is a consequence of a compositional segregation/twist phase transition. Since twist coexistence is a compositional equilibrium, it arises from the exchange between bulk phases; hence, the detailed nature of the atomic structure within an interface between twisted and untwisted zones is not relevant. The approach places crystal-twist phenomena within the theory of order/disorder phase transitions.
Zheng, Xiu-Deng; Li, Cong; Yu, Jie-Ru; Wang, Shi-Chang; Fan, Song-Jia; Zhang, Bo-Yu; Tao, Yi
2017-05-07
The long-term coexistence of cooperation and defection is a common phenomenon in nature and human society. However, none of the theoretical models based on the Prisoner's Dilemma (PD) game can provide a concise theoretical model to explain what leads to the stable coexistence of cooperation and defection in the long-term even though some rules for promoting cooperation have been summarized (Nowak, 2006, Science 314, 1560-1563). Here, based on the concept of direct reciprocity, we develop an elementary model to show why stable coexistence of cooperation and defection in the PD game is possible. The basic idea behind our theoretical model is that all players in a PD game prefer a cooperator as an opponent, and our results show that considering strategies allowing opting out against defection provide a general and concise way of understanding the fundamental importance of direct reciprocity in driving the evolution of cooperation. Copyright © 2017 Elsevier Ltd. All rights reserved.
Coexistence Analysis of Adjacent Long Term Evolution (LTE) Systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aulama, Mohannad M.; Olama, Mohammed M
As the licensing and deployment of Long term evolution (LTE) systems are ramping up, the study of coexistence of LTE systems is an essential topic in civil and military applications. In this paper, we present a coexistence study of adjacent LTE systems aiming at evaluating the effect of inter-system interference on system capacity and performance as a function of some of the most common mitigation techniques: frequency guard band, base station (BS) antenna coupling loss, and user equipment (UE) antenna spacing. A system model is constructed for two collocated macro LTE networks. The developed model takes into consideration the RFmore » propagation environment, power control scheme, and adjacent channel interference. Coexistence studies are performed for a different combination of time/frequency division duplex (TDD/FDD) systems under three different guard-bands of 0MHz, 5MHz, and 10MHz. Numerical results are presented to advice the minimum frequency guard band, BS coupling loss, and UE antenna isolation required for a healthy system operation.« less
Garzon-Lopez, Carol X; Ballesteros-Mejia, Liliana; Ordoñez, Alejandro; Bohlman, Stephanie A; Olff, Han; Jansen, Patrick A
2015-08-01
The coexistence of numerous tree species in tropical forests is commonly explained by negative dependence of recruitment on the conspecific seed and tree density due to specialist natural enemies that attack seeds and seedlings ('Janzen-Connell' effects). Less known is whether guilds of shared seed predators can induce a negative dependence of recruitment on the density of different species of the same plant functional group. We studied 54 plots in tropical forest on Barro Colorado Island, Panama, with contrasting mature tree densities of three coexisting large seeded tree species with shared seed predators. Levels of seed predation were far better explained by incorporating seed densities of all three focal species than by conspecific seed density alone. Both positive and negative density dependencies were observed for different species combinations. Thus, indirect interactions via shared seed predators can either promote or reduce the coexistence of different plant functional groups in tropical forest. © 2015 John Wiley & Sons Ltd/CNRS.
ERIC Educational Resources Information Center
Alexander, Hanan
2007-01-01
In this essay I critique two influential accounts of rational autonomy in common schooling that conceive liberalism as an ideal form of life, and I offer an alternative approach to democratic education that views liberal theory as concerned with coexistence among rival ways of living. This view places moral agency, not rational autonomy, at the…
Geriatric Syndromes in Hospitalized Older Adults Discharged to Skilled Nursing Facilities.
Bell, Susan P; Vasilevskis, Eduard E; Saraf, Avantika A; Jacobsen, J M L; Kripalani, Sunil; Mixon, Amanda S; Schnelle, John F; Simmons, Sandra F
2016-04-01
To determine the prevalence, recognition, co-occurrence, and recent onset of geriatric syndromes in individuals transferred from the hospital to a skilled nursing facility (SNF). Quality improvement project. Acute care academic medical center and 23 regional partner SNFs. Medicare beneficiaries hospitalized between January 2013 and April 2014 and referred to SNFs (N = 686). Project staff measured nine geriatric syndromes: weight loss, lack of appetite, incontinence, and pain (standardized interview); depression (Geriatric Depression Scale); delirium (Brief Confusion Assessment Method); cognitive impairment (Brief Interview for Mental Status); and falls and pressure ulcers (hospital medical record using hospital-implemented screening tools). Estimated prevalence, new-onset prevalence, and common coexisting clusters were determined. The extent to which treating physicians commonly recognized syndromes and communicated them to SNFs in hospital discharge documentation was evaluated. Geriatric syndromes were prevalent in more than 90% of hospitalized adults referred to SNFs; 55% met criteria for three or more coexisting syndromes. The most-prevalent syndromes were falls (39%), incontinence (39%), loss of appetite (37%), and weight loss (33%). In individuals who met criteria for three or more syndromes, the most common triad clusters were nutritional syndromes (weight loss, loss of appetite), incontinence, and depression. Treating hospital physicians commonly did not recognize and document geriatric syndromes in discharge summaries, missing 33% to 95% of syndromes present according to research personnel. Geriatric syndromes in hospitalized older adults transferred to SNFs are prevalent and commonly coexist, with the most frequent clusters including nutritional syndromes, depression, and incontinence. Despite the high prevalence, this clinical information is rarely communicated to SNFs on discharge. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.
Citric Acid Enhanced Copper Removal by a Novel Multi-amines Decorated Resin
Ling, Chen; Liu, Fuqiang; Pei, Zhiguo; Zhang, Xiaopeng; Wei, Mengmeng; Zhang, Yanhong; Zheng, Lirong; Zhang, Jing; Li, Aimin; Xing, Baoshan
2015-01-01
Cu removal by a novel multi-amines decorated resin (PAMD) from wastewater in the absence or presence of citric acid (CA) was examined. Adsorption capacity of Cu onto PAMD markedly increased by 186% to 5.07 mmol/g in the presence of CA, up to 7 times of that onto four commercial resins under the same conditions. Preloaded and kinetic studies demonstrated adsorption of [Cu-CA] complex instead of CA site-bridging and variations of adsorbate species were qualitatively illustrated. The interaction configuration was further studied with ESI-MS, FTIR, XPS and XANES characterizations. The large enhancement of Cu adsorption in Cu-CA bi-solutes systems was attributed to mechanism change from single-site to dual-sites interaction in which cationic or neutral Cu species (Cu2+ and CuHL0) coordinated with neutral amine sites and anionic complex species (CuL− and Cu2L22−) directly interacted with protonated amine sites via electrostatic attraction, and the ratio of the two interactions was approximately 0.5 for the equimolar bi-solutes system. Moreover, commonly coexisting ions in wastewaters had no obvious effect on the superior performance of PAMD. Also, Cu and CA could be recovered completely with HCl. Therefore, PAMD has a great potential to efficiently remove heavy metal ions from wastewaters in the presence of organic acids. PMID:25962970
Dong, Yuwei; Fan, Ruiqing; Chen, Wei; Wang, Ping; Yang, Yulin
2017-05-23
A new simple 'dual' chemosensor MQA ((E)-2-methoxy-N-((quinolin-2-yl)methylene)aniline) for distinguishing Zn 2+ and Hg 2+ has been designed, synthesized and characterized. The sensor showed excellent selectivity and sensitivity with a fluorescence enhancement to Zn 2+ /Hg 2+ over other commonly coexisting cations (such as Na + , Mg 2+ , Al 3+ , K + , Mn 2+ , Fe 2+ , Fe 3+ , Co 2+ , Ni 2+ , Cu 2+ , Ga 3+ , Cd 2+ , In 3+ and Pb 2+ ) in DMSO-H 2 O solution (1/99 v/v), which was reversible with the addition of ethylenediaminetetraacetic acid (EDTA). The detection limit for Zn 2+ /Hg 2+ by MQA both reached the 10 -8 M level. The 1 : 1 ligand-to-metal coordination patterns of the MQA-Zn2+ and MQA-Hg2+ were calculated through a Job's plot and ESI-MS spectra, and were further confirmed by X-ray crystal structures of complexes MQA-Zn2+ and MQA-Hg2+. This chemosensor can recognize similar metal ions by coherently utilizing intramolecular charge transfer (ICT) and different electronic affinities of various metal ions. DFT calculations have revealed that the energy gap between the HOMO and LUMO of MQA has decreased upon coordination with Zn(ii)/Hg(ii).
Spartalis, Eleftherios; Garmpis, Nikolaos; Spartalis, Michael; Damaskos, Christos; Moris, Demetrios; Athanasiou, Antonios; Gkolfakis, Paraskevas; Korkolopoulou, Penelope; Dimitroulis, Dimitrios; Mantas, Dimitrios
2018-01-01
Adenocarcinoma is one of the most common malignant tumors of the small intestine complicating Crohn's disease. However, the coexistence of both conditions with diverticulosis of small bowel in young age makes this coincidence rare and clinical diagnosis very difficult. We report a case of a woman admitted to our Department with acute abdominal pain and fever. The surgical and histological investigation, revealed a rare coexistence that has never been mentioned in the published medical literature. Ileal diverticulosis is not frequent and often asymptomatic as well as adenocarcinoma of the small bowel. In this case, those diseases along with Crohn's disease led the patient to acute symptoms. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.
The coexistence of renal artery stenosis and pheochromocytoma.
Hill, F S; Jander, H P; Murad, T; Diethelm, A G
1983-01-01
The coexistence of renal artery stenosis and pheochromocytoma has been recognized since 1958 and a total of 36 patients reported. This article provides an additional patient with an extra adrenal pheochromocytoma and fibrous bands constricting the left renal artery. Hypertension was confirmed to occur from both excess catecholamine production and hyperreninemia from the left kidney. Surgical removal of the functioning paraganglioma and correction of the renal artery stenosis restored the postoperative plasma catecholamine, renin, and blood pressure to normal. A literature review confirmed the coexistence of these two lesions but failed to provide a common etiology to explain the pathophysiology encountered. However, when the two diseases occur simultaneously, both must be diagnosed accurately and treated in a definitive manner. Images Figs. 1a and b. Figs. 2a and b. PMID:6830355
A statistical study of ions and magnetic fields in the Venus magnetotail
NASA Technical Reports Server (NTRS)
Moore, K. R.; Mccomas, D. J.; Russell, C. T.; Mihalov, J. D.
1990-01-01
A statistical characterization is made of the combined ion and magnetic field properties of the Venus magnetosheath and magnetotail, on the basis of plasma and magnetic field data from 223 Pioneer Venus orbits; no assumptions are made as to existing regions or their plasma and field characteristics. Plasma is found to flow tailward in all locations, and the magnetotail is highly draped. Weak magnetic field asymmetries are associated with the plasma dropouts. A high-E/q plasma population, previously interpreted as planetary-pickup ions, is found asymmetrically both within the tail and in the adjacent sheath. The Venus tail is filled with plasma that is primarily shocked solar wind, at fluxes that are sometimes undetectable; the tail coexists with a photoion population which generates asymmetries in the bulk plasma and magnetic field properties.
... people with chronic bronchitis are current or former smokers. Chronic bronchitis is usually part of the spectrum ... and emphysema often coexist in current or former smokers with COPD. Less commonly, chronic cough may be ...
NASA Astrophysics Data System (ADS)
Liu, Jing; Ren, Xiangling; Meng, Xianwei; Fang, Zheng; Tang, Fangqiong
2013-09-01
An easily prepared fluorescent Ag nanoclusters (Ag NCs) probe for the sensitive and selective detection of Hg2+ and Cu2+ ions was developed here. The Ag NCs were synthesized by using polymethacrylic acid sodium salt as a template via a convenient hydrothermal process. The as-prepared fluorescent Ag NCs were monodispersed, uniform and less than 2 nm in diameter, and can be quenched in the presence of mercury (Hg2+) or copper (Cu2+) ions. Excellent linear relationships existed between the quenching degree of the Ag NCs and the concentrations of Hg2+ or Cu2+ ions in the range of 10 nM to 20 μM or 10 nM to 30 μM, respectively. By using ethylenediaminetetraacetate (EDTA) as the masking agent of Cu2+, Hg2+ was exclusively detected in coexistence with Cu2+ with high sensitivity (LOD = 10 nM), which also provided a reusable detection method for Cu2+. Furthermore, the different quenching phenomena caused by the two metals ions such as changes in visible colour, shifts of UV absorbance peaks and changes in size of Ag NCs make it easy to distinguish between them. Therefore the easily synthesized fluorescent Ag NCs may have great potential as Hg2+ and Cu2+ ions sensors.An easily prepared fluorescent Ag nanoclusters (Ag NCs) probe for the sensitive and selective detection of Hg2+ and Cu2+ ions was developed here. The Ag NCs were synthesized by using polymethacrylic acid sodium salt as a template via a convenient hydrothermal process. The as-prepared fluorescent Ag NCs were monodispersed, uniform and less than 2 nm in diameter, and can be quenched in the presence of mercury (Hg2+) or copper (Cu2+) ions. Excellent linear relationships existed between the quenching degree of the Ag NCs and the concentrations of Hg2+ or Cu2+ ions in the range of 10 nM to 20 μM or 10 nM to 30 μM, respectively. By using ethylenediaminetetraacetate (EDTA) as the masking agent of Cu2+, Hg2+ was exclusively detected in coexistence with Cu2+ with high sensitivity (LOD = 10 nM), which also provided a reusable detection method for Cu2+. Furthermore, the different quenching phenomena caused by the two metals ions such as changes in visible colour, shifts of UV absorbance peaks and changes in size of Ag NCs make it easy to distinguish between them. Therefore the easily synthesized fluorescent Ag NCs may have great potential as Hg2+ and Cu2+ ions sensors. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr03329e
NASA Astrophysics Data System (ADS)
Tomlinson, E. L.; Müller, W.; EIMF
2009-03-01
We have determined the trace element compositions of coexisting fluid (carbonate-K-chloride-H 2O) and single-phase mineral inclusions in peridotitic (Cr-diopside) and eclogitic (omphacite, garnet) inclusions in fibrous diamonds from the Panda kimberlite (Slave craton, Canada). These diamonds provide a unique insight into the nature of the metasomatic agent, the metasomatised minerals and the pre-metasomatic protolith. The fluid component is strongly enriched in light rare earth elements (LREE) and large ion lithophile elements (LILE). Co-existing peridotitic minerals record a melt extraction event (high Cr and Ni) in the protolith prior to the influx of the trapped metasomatic fluid. The silicate minerals are also strongly enriched in LREE. Calculated partition coefficients agree with experimentally determined values in the literature, despite the complex composition of the natural fluid. This indicates that the minerals have re-equilibrated with the metasomatic fluid. The trace element compositions of the mineral inclusions are comparable to many equivalent phases in monocrystalline diamonds. This suggests that the metasomatic fluid and the process recorded in these samples may also be responsible for the growth of some types of monocrystalline diamonds.
Luminescence properties and color identification of Eu doped Ca3(PO4)2 phosphors calcined in air
NASA Astrophysics Data System (ADS)
Tong, Chao; Zhu, Yangguang; Xu, Chuanyan; Yang, Lei; Li, Yadong
2017-09-01
The Ca3(PO4)2:Eu (TCP) phosphor was synthesized by a high-temperature solid-state reaction in air atmosphere. X-ray powder diffraction(XRD) analysis indicates that the α-TCP↔β-TCP phase transition takes place under different calcination and cooling conditions. The luminescence properties of the two different phases of TCP were discussed according to the luminescence spectra during the heating and cooling transition. The CIE chromaticity coordinates of β-TCP phase located at the red region, α-TCP phase at bluish-green region because of the coexistence of Eu2+ and Eu3+ ions. The color-tunable emission of the products could also be directly observed under UV lamp. Pure red and bluish-green-emitting particles were observed respectively for the pure β-TCP phase and α-TCP phase samples whereas bluish-green and red mixture emitting particles were traced for the α-TCP /β-TCP phase co-existence samples. Therefore, results of this study suggested that Eu ion could be used as a spectroscopic probe to qualitatively identify the crystalline phase of TCP by a simple and convenient way to observe the color-tunable emission of the samples when irradiating it under 365 nm UV lamp.
Surfactants present complex joint effects on the toxicities of metal oxide nanoparticles.
Wang, Dali; Lin, Zhifen; Yao, Zhifeng; Yu, Hongxia
2014-08-01
The potential toxicities of nanoparticles (NPs) have been intensively discussed over the past decade. In addition to their single toxicities, NPs can interact with other environmental chemicals and thereby exert joint effects on biological systems and the environment. The present study investigated the combined toxicities of NPs and surfactants, which are among the chemicals that most likely coexist with NPs. Photobacterium phosphoreum was employed as the model organism. The results indicate that surfactants with different ion types can alter the properties of NPs (i.e., particle size and surface charge) in different ways and present complex joint effects on NP toxicities. Mixtures of different NPs and surfactants exhibited antagonistic, synergistic, and additive effects. In particular, the toxicity of ZnO was observed to result from its dissolved Zn(2+); thus, the joint effects of the ZnO NPs and surfactants can be explained by the interactions between the Zn ions and the surfactants. Our study suggests that the potential hazards caused by mixtures of NPs and surfactants are different from those caused by single NPs. Because surfactants are extensively used in the field of nanotechnology and are likely to coexist with NPs in natural waters, the ecological risk assessments of NPs should consider the impacts of surfactants. Copyright © 2014 Elsevier Ltd. All rights reserved.
Enhanced oxidation of arsenite to arsenate using tunable K+ concentration in the OMS-2 tunnel.
Hou, Jingtao; Sha, Zhenjie; Hartley, William; Tan, Wenfeng; Wang, Mingxia; Xiong, Juan; Li, Yuanzhi; Ke, Yujie; Long, Yi; Xue, Shengguo
2018-07-01
Cryptomelane-type octahedral molecular sieve manganese oxide (OMS-2) possesses high redox potential and has attracted much interest in its application for oxidation arsenite (As(III)) species of arsenic to arsenate (As(V)) to decrease arsenic toxicity and promote total arsenic removal. However, coexisting ions such as As(V) and phosphate are ubiquitous and readily bond to manganese oxide surface, consequently passivating surface active sites of manganese oxide and reducing As(III) oxidation. In this study, we present a novel strategy to significantly promote As(III) oxidation activity of OMS-2 by tuning K + concentration in the tunnel. Batch experimental results reveal that increasing K + concentration in the tunnel of OMS-2 not only considerably improved As(III) oxidation kinetics rate from 0.027 to 0.102 min -1 , but also reduced adverse effect of competitive ion on As(III) oxidation. The origin of K + concentration effect on As(III) oxidation was investigated through As(V) and phosphate adsorption kinetics, detection of Mn 2+ release in solution, surface charge characteristics, and density functional theory (DFT) calculations. Experimental results and theoretical calculations confirm that by increasing K + concentration in the OMS-2 tunnel not only does it improve arsenic adsorption on K + doped OMS-2, but also accelerates two electrons transfers from As(III) to each bonded Mn atom on OMS-2 surface, thus considerably improving As(III) oxidation kinetics rate, which is responsible for counteracting the adverse adsorption effects by coexisting ions. Copyright © 2018 Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Narey, Daniel C.
2012-01-01
Democracy is often theorized as a form of political association grounded in shared meanings, common experiences, and convergent interests among the associated individuals. Because differences and divergences seem to stand in the way of commonality and consensus, the coexistence of a plurality of meanings, experiences, interests, languages,…
Magnetic Phase Transition in Ion-Irradiated Ultrathin CoN Films via Magneto-Optic Faraday Effect.
Su, Chiung-Wu; Chang, Yen-Chu; Chang, Sheng-Chi
2013-11-15
The magnetic properties of 1 nm thick in-plane anisotropic Co ultrathin film on ZnO(0001) were investigated through successive 500 eV nitrogen-ion sputtering. Magneto-optical Faraday effects were used to observe the evolution of the ion-irradiated sample in longitudinal and perpendicular magnetic fields. The ferromagnetic phase of the initial in-plane anisotropic fcc β-Co phase transformation to β-Co(N) phase was terminated at paramagnetic CoN x phase. In-plane anisotropy with weak out-of-plane anisotropy of the Co/ZnO sample was initially observed in the as-grown condition. In the sputtering process, the N⁺ ions induced simultaneous sputtering and doping. An abrupt spin reorientation behavior from in-plane to out-of-plane was found under prolonged sputtering condition. The existence of perpendicular anisotropy measured from the out-of-plane Faraday effect may be attributed to the co-existence of residual β-Co and Co₄N exchange bonding force by the gradual depletion of Co-N thickness.
Lifetime measurements using the recoil distance method—achievements and perspectives
NASA Astrophysics Data System (ADS)
Krücken, R.
2001-07-01
The recoil distance method (RDM) for measuring pico-second nuclear level lifetimes and its use in nuclear structure studies is reviewed and perspectives for the future are presented. High precision measurements in the mass-130 region, studies of multi-phonon states in rare earth nuclei, the investigation of shape coexistence and the recently discovered phenomenon of "magnetic rotation" are reviewed. Prospects for lifetime measurements in exotic regions of nuclei such as the measurement of lifetimes in neutron rich nuclei populated via spontaneous and heavy-ion induced fission are discussed. Other prospects include the use of the RDM technique in conjunction with recoil separators. The relevance of these techniques for experiments with radioactive ion beams will be discussed.
Coexistence of gastrointestinal stromal tumor (GIST) and colorectal adenocarcinoma: A case report.
Efstathios, Papalambros; Athanasios, Petrou; Papaconstantinou, Ioannis; Alexandros, Papalambros; Frangisca, Sigala; Sotirios, Georgopoulos; Evangelos, Felekouras; Athanasios, Giannopoulos
2007-08-21
Gastrointestinal stromal tumors (GIST) represent the most common mesenchymal tumors of the digestive tract. Over the last ten years the management of GISTs has dramatically altered but their coexistence with other gasrointesinal tumors of different histogenesis presents a special interest. The coexistence of GISTs with other primaries is usually discovered incidentally during GI surgery for carcinomas. We present here, a case of a 66-year-old patient with intestinal GIST and a synchronous colorectal adenocarcinoma discovered incidentally during surgical treatment of the recurrent GIST. Immunohistochemical examination revealed the concurrence of histologically proved GIST (strongly positive staining for c-kit, vimentin, SMA, and focal positive in S-100, while CD-34 was negative) and Dukes Stage C, (T3, N3, M0 according the TNM staging classification of colorectal cancer). The coexistence of GIST with either synchronous or metachronous colorectal cancer represents a phenomenon with increasing number of relative reports in the literature the last 5 years. In any case of GIST the surgeon should be alert to recognize a possible coexistent tumor with different histological origin and to perform a thorough preoperative and intraoperative control. The correct diagnosis before and at the time of the surgical procedure is the cornerstone that secures the patients' best prognosis.
Ion evaporation from the surface of a Taylor cone.
Higuera, F J
2003-07-01
An analysis is carried out of the electric field-induced evaporation of ions from the surface of a polar liquid that is being electrosprayed in a vacuum. The high-field cone-to-jet transition region of the electrospray, where ion evaporation occurs, is studied taking advantage of its small size and neglecting the inertia of the liquid and the space charge around the liquid. Evaporated ions and charged drops coexist in a range of flow rates, which is investigated numerically. The structure of the cone-to-jet transition comprises: a hydrodynamic region where the nearly equipotential surface of the liquid departs from a Taylor cone and becomes a jet; a slender region where the radius of the jet decreases and the electric field increases while the pressure and the viscous stress balance the electric stress at the surface; the ion evaporation region of high, nearly constant field; and a charged, continuously strained jet that will eventually break into drops. Estimates of the ion and drop contributions to the total, conduction-limited current show that the first of these contributions dominates for small flow rates, while most of the mass is still carried by the drops.
Existence domain of electrostatic solitary waves in the lunar wake
NASA Astrophysics Data System (ADS)
Rubia, R.; Singh, S. V.; Lakhina, G. S.
2018-03-01
Electrostatic solitary waves (ESWs) and double layers are explored in a four-component plasma consisting of hot protons, hot heavier ions (He++), electron beam, and suprathermal electrons having κ-distribution using the Sagdeev pseudopotential method. Three modes exist: slow and fast ion-acoustic modes and electron-acoustic mode. The occurrence of ESWs and their existence domain as a function of various plasma parameters, such as the number densities of ions and electron beam, the spectral index, κ, the electron beam velocity, the temperatures of ions, and electron beam, are analyzed. It is observed that both the slow and fast ion-acoustic modes support both positive and negative potential solitons as well as their coexistence. Further, they support a "forbidden gap," the region in which the soliton ceases to propagate. In addition, slow ion-acoustic solitons support the existence of both positive and negative potential double layers. The electron-acoustic mode is only found to support negative potential solitons for parameters relevant to the lunar wake plasma. Fast Fourier transform of a soliton electric field produces a broadband frequency spectrum. It is suggested that all three soliton types taken together can provide a good explanation for the observed electrostatic waves in the lunar wake.
Membrane Bending Moduli of Coexisting Liquid Phases Containing Transmembrane Peptide.
Usery, Rebecca D; Enoki, Thais A; Wickramasinghe, Sanjula P; Nguyen, V P; Ackerman, David G; Greathouse, Denise V; Koeppe, Roger E; Barrera, Francisco N; Feigenson, Gerald W
2018-05-08
A number of highly curved membranes in vivo, such as epithelial cell microvilli, have the relatively high sphingolipid content associated with "raft-like" composition. Given the much lower bending energy measured for bilayers with "nonraft" low sphingomyelin and low cholesterol content, observing high curvature for presumably more rigid compositions seems counterintuitive. To understand this behavior, we measured membrane rigidity by fluctuation analysis of giant unilamellar vesicles. We found that including a transmembrane helical GWALP peptide increases the membrane bending modulus of the liquid-disordered (Ld) phase. We observed this increase at both low-cholesterol fraction and higher, more physiological cholesterol fraction. We find that simplified, commonly used Ld and liquid-ordered (Lo) phases are not representative of those that coexist. When Ld and Lo phases coexist, GWALP peptide favors the Ld phase with a partition coefficient of 3-10 depending on mixture composition. In model membranes at high cholesterol fractions, Ld phases with GWALP have greater bending moduli than the Lo phase that would coexist. Copyright © 2018 Biophysical Society. Published by Elsevier Inc. All rights reserved.
Life history trade-offs and community dynamics of small fishes in a seasonally pulsed wetland
DeAngelis, D.L.; Trexler, J.C.; Loftus, W.F.
2005-01-01
We used a one-dimensional, spatially explicit model to simulate the community of small fishes in the freshwater wetlands of southern Florida, USA. The seasonality of rainfall in these wetlands causes annual fluctuations in the amount of flooded area. We modeled fish populations that differed from each other only in efficiency of resource utilization and dispersal ability. The simulations showed that these trade-offs, along with the spatial and temporal variability of the environment, allow coexistence of several species competing exploitatively for a common resource type. This mechanism, while sharing some characteristics with other mechanisms proposed for coexistence of competing species, is novel in detail. Simulated fish densities resembled patterns observed in Everglades empirical data. Cells with hydroperiods less than 6 months accumulated negligible fish biomass. One unique model result was that, when multiple species coexisted, it was possible for one of the coexisting species to have both lower local resource utilization efficiency and lower dispersal ability than one of the other species. This counterintuitive result is a consequence of stronger effects of other competitors on the superior species. ?? 2005 NRC.
Coexisting stable conformations of gaseous protein ions.
Suckau, D; Shi, Y; Beu, S C; Senko, M W; Quinn, J P; Wampler, F M; McLafferty, F W
1993-01-01
For further insight into the role of solvent in protein conformer stabilization, the structural and dynamic properties of protein ions in vacuo have been probed by hydrogen-deuterium exchange in a Fourier-transform mass spectrometer. Multiply charged ions generated by electrospray ionization of five proteins show exchange reactions with 2H2O at 10(-7) torr (1 torr = 133.3 Pa) exhibiting pseudo-first-order kinetics. Gas-phase compactness of the S-S cross-linked RNase A relative to denatured S-derivatized RNase A is indicated by exchange of 35 and 135 hydrogen atoms, respectively. For pure cytochrome c ions, the existence of at least three distinct gaseous conformers is indicated by the substantially different values--52, 113, and 74--of reactive H atoms; the observation of these same values for ions of a number--2, 7, and 5, respectively--of different charge states indicates conformational insensitivity to coulombic forces. For each of these conformers, the compactness in vacuo indicated by these values corresponds directly to that of a known conformer structure in the solution from which the conformer ions are produced by electrospray. S-derivatized RNase A ions also exist as at least two gaseous conformers exchanging 50-140 H atoms. Gaseous conformer ions are isometrically stable for hours; removal of solvent greatly increases conformational rigidity. More specific ion-molecule reactions could provide further details of conformer structures. Images PMID:8381533
Effect of co-existing copper and calcium on the removal of As(V) by reused aluminum oxides.
Yang, J K; Park, Y J; Kim, K H; Lee, H Y; Min, K C; Lee, S M
2013-01-01
Among the various heavy metals, arsenic is frequently found in abandoned mine drainage and the environmental fate of arsenic in real aqueous solutions can be highly dependent on the presence of co-existing ions. In this study, removal of arsenate through adsorption on the reused aluminum oxide or through precipitation was investigated in a single and in a binary system as a function of pH and concentration. Different removal behaviors of arsenate were observed in the presence of different cations as well as a variation of the molar ratios of arsenate to cations. Co-operative effects on arsenate removal by precipitation in solution occurred with an increase of copper concentration, while a decrease of arsenate removal resulted in increasing calcium concentration. It was observed that the arsenate removal in the presence of calcium would be highly dependent on the molar ratios of both elements.
Facile approach to prepare nickel cobaltite nanowire materials for supercapacitors.
Wang, Huanlei; Gao, Qiuming; Jiang, Lei
2011-09-05
Excellent electrochemical performance results from the coexistence of nickel and cobalt ions, with mesoporous characteristics and nanocrystal structure. Nickel cobalt nanowire is prepared by hydrothermal and thermal decomposition processes. High capacitance of 722 F g(-1) can be obtained at 1 A g(-1) in 6 M KOH, with a capacitance retention ratio of ca. 79% at 20 A g(-1) . Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Edge-core interaction of ITG turbulence in Tokamaks: Is the Tail Wagging the Dog?
NASA Astrophysics Data System (ADS)
Ku, S.; Chang, C. S.; Dif-Pradalier, G.; Diamond, P. H.
2010-11-01
A full-f XGC1 gyrokinetic simulation of ITG turbulence, together with the neoclassical dynamics without scale separation, has been performed for the whole-volume plasma in realistic diverted DIII-D geometry. The simulation revealed that the global structure of the turbulence and transport in tokamak plasmas results from a synergy between edge-driven inward propagation of turbulence intensity and the core-driven outward heat transport. The global ion confinement and the ion temperature gradient then self-organize quickly at turbulence propagation time scale. This synergy results in inward-outward pulse scattering leading to spontaneous production of strong internal shear layers in which the turbulent transport is almost suppressed over several radial correlation lengths. Co-existence of the edge turbulence source and the strong internal shear layer leads to radially increasing turbulence intensity and ion thermal transport profiles.
Nonextensive statistical mechanics approach to electron trapping in degenerate plasmas
NASA Astrophysics Data System (ADS)
Mebrouk, Khireddine; Gougam, Leila Ait; Tribeche, Mouloud
2016-06-01
The electron trapping in a weakly nondegenerate plasma is reformulated and re-examined by incorporating the nonextensive entropy prescription. Using the q-deformed Fermi-Dirac distribution function including the quantum as well as the nonextensive statistical effects, we derive a new generalized electron density with a new contribution proportional to the electron temperature T, which may dominate the usual thermal correction (∼T2) at very low temperatures. To make the physics behind the effect of this new contribution more transparent, we analyze the modifications arising in the propagation of ion-acoustic solitary waves. Interestingly, we find that due to the nonextensive correction, our plasma model allows the possibility of existence of quantum ion-acoustic solitons with velocity higher than the Fermi ion-sound velocity. Moreover, as the nonextensive parameter q increases, the critical temperature Tc beyond which coexistence of compressive and rarefactive solitons sets in, is shifted towards higher values.
Soylak, Mustafa; Unsal, Yunus Emre
2011-10-01
A preconcentration-separation procedure has been established based on solid-phase extraction of Fe(III) and Pb(II) on bucky tubes (BTs) disc. Fe(III) and Pb(II) ions were quantitatively recovered at pH 6. The influences of the analytical parameters like sample volume, flow rates on the recoveries of analytes on BT disc were investigated. The effects of co-existing ions on the recoveries were also studied. The detection limits for iron and lead were found 1.6 and 4.9 μg L⁻¹, respectively. The validation of the presented method was checked by the analysis of TMDA-51.3 fortified water certified reference material. The presented procedure was successfully applied to the separation-preconcentration and determination of iron and lead content of some natural water and herbal plant samples from Kayseri, Turkey.
Evaluation of coexistence of cancer and active tuberculosis; 16 case series.
Çakar, Beyhan; Çiledağ, Aydın
2018-01-01
Tuberculosis is an important risk factor for cancer. Pulmonary TB and lung cancer(LC) may mimic each other especially in the aspect of the clinical and radiological features. The aim of the study was to evaluate the features and risk factors of cases with coexistence cancer and active TB. We retrospectively reviewed the medical records of patients with coexisting TB and cancer a period from 2009 to 2014. We evaluated demographic data, the ways diagnosis of TB cases, the location of TB and cancer, TB treatment results of the cases. We recorded 374 TB cases in our dyspensary at this study period. In 16 (4%) of these cases, a coexistence of cancer and TB was detected. The male/female ratio was 12/4. The mean age was 62,12 ± 15,13 years. There were TST results except three cases. There were ten pulmonary TB and six extra-pulmonary TB (four peripheral lymphadenopathy TB, one abdominal TB lymphadenopathy and one salivary gland TB). Cancer types were as follows; eight lung cancer, two breast cancer, one base of tongue, one endometrium cancer, one hypopharyngeal cancer, one stomach cancer, one bladder cancer and one maxillary cancer. Diagnosis of all cases was confirmed by bacteriologic and/or histopathological examination. Squamous cell carcinoma was the most common type of cancers. This rate was 9/16. All TB cases were new. There were risk factors out of two case in the cases. Five cases were died during TB treatment. Others completed TB treatment without any complication. In our study, the coexistence of LC and pulmonary TB was more common. The local immunity is deteriorated in cancer cases. If there is pulmonary infiltrates in lung or peripheral lymphadenopathy, we must search tuberculosis too out of metastatic lesion and other infectious diseases. We should not make delay in the diagnosis of active TB in cancer cases.
Kesavaraju, Banugopan; Damal, Kavitha; Juliano, Steven A.
2009-01-01
Predator-mediated coexistence of competitors occurs when a species that is superior in competition is also more vulnerable to a shared predator compared to a poorer competitor. The invasive mosquito Aedes albopictus is usually competitively superior to Ochlerotatus triseriatus. Among second instar larvae, A. albopictus show a lesser degree of behavioral modiWcation in response to waterborne cues from predation by the larval midge Corethrella appendiculata than do O. triseriatus, rendering A. albopictus more vulnerable to predation by C. appendiculata than O. triseriatus. The hypothesis that C. appendiculata predation favors coexistence of these competitors predicts that C. appendiculata abundances will be negatively and positively correlated with A. albopictus and O. triseriatus abundances, respectively, and that coexistence will occur where C. appendiculata are common. Actual abundances of O. triseriatus, A. albopictus, and C. appendiculata in three habitats Wt this prediction. In natural container habitats like tree holes, C. appendiculata were abundant and competitors co-existed at similar densities. In cemeteries and tires, which occur primarily in non-forested, human-dominated habitats, A. albopictus dominated, with abundances twice those found in tree holes, but C. appendiculata and O. triseriatus were rare or absent. We also tested for whether antipredatory behavioral responses of A. albopictus differed among habitats or populations, or were correlated with local C. appendiculata abundances. We could detect no differences in A. albopictus antipredatory behavioral responses to water-borne cues from predation. Tree hole habitats appear to promote co-existence of O. triseriatus and A. albopictus through interactions with predatory C. appendiculata, and this predator effect appears to limit invasion success of A. albopictus in tree holes. There are many studies on predator-mediated coexistence in natural habitats but to our knowledge this is the first study to suggest differential predator-mediated coexistence between natural and man-made habitats. PMID:18075759
Wang, Hongyu; Liu, Yibing; Jiang, Jia-Qian
2016-07-01
This paper investigates the degradation of acetaminophen (AAP) in aqueous solutions by ferrate (VI), aiming to propose the kinetics, pathways and the oxidation products' formation in the AAP degradation. A series of jar tests were undertaken over ferrate (VI) dosages (molar ratios of ferrate (VI):AAP, 5:1 to 25:1) and pH values (4-11). The effects of co-existing ions (0.2-5 mM) and humic acid (10-50 mg l(-1)) on the AAP removal were investigated. Ferrate (VI) can remove 99.6% AAP (from 1000 μg l(-1)) in 60 min under study conditions when majority of the AAP reduction occurred in the first 5 min. The treatment performance depended on the ferrate(VI) dosage, pH and the type and strength of co-existing ions and humic acid. Raising ferrate (VI) dosage with optimal pH 7 improved the AAP degradation. In the presence of humic acid, the AAP degradation by ferrate (VI) was promoted in a short period (<30 min) but then inhibited with increasing in humic acid contents. The presence of Al(3+), CO3(2-) and PO4(3-) ions declined but the existence of K(+), Na(+), Mg(2+) and Ca(2+) ions can improve the AAP removal. The catalytic function of Al(3+) on the decomposition of ferrate (VI) in aqueous solution was found. The kinetics of the reaction between ferrate (VI) and AAP was pseudo first-order for ferrete (VI) and pseudo second-order for AAP. The pseudo rate constant of ferrate (VI) with AAP was 1.4 × 10(-5) L(2) mg(-2) min(-1). Three oxidation products (OPs) were identified and the AAP degradation pathways were proposed. Copyright © 2016 Elsevier Ltd. All rights reserved.
Zutt, Rodi; Dijk, Joke M; Peall, Kathryn J; Speelman, Hans; Dreissen, Yasmine E M; Contarino, Maria Fiorella; Tijssen, Marina A J
2016-01-01
Myoclonus-dystonia (M-D) is a young onset movement disorder typically involving myoclonus and dystonia of the upper body. A proportion of the cases are caused by mutations to the autosomal dominantly inherited, maternally imprinted, epsilon-sarcoglycan gene (SGCE). Despite several sets of diagnostic criteria, identification of patients most likely to have an SGCE mutation remains difficult. Forty consecutive patients meeting pre-existing diagnostic clinical criteria for M-D underwent a standardized clinical examination (20 SGCE mutation positive and 20 negative). Each video was reviewed and systematically scored by two assessors blinded to mutation status. In addition, the presence and coexistence of myoclonus and dystonia was recorded in four body regions (neck, arms, legs, and trunk) at rest and with action. Thirty-nine patients were included in the study (one case was excluded owing to insufficient video footage). Based on previously proposed diagnostic criteria, patients were subdivided into 24 "definite," 5 "probable," and 10 "possible" M-D. Motor symptom severity was higher in the SGCE mutation-negative group. Myoclonus and dystonia were most commonly observed in the neck and upper limbs of both groups. Truncal dystonia with action was significantly seen more in the mutation-negative group (p < 0.05). Coexistence of myoclonus and dystonia in the same body part with action was more commonly seen in the mutation-negative cohort (p < 0.05). Truncal action dystonia and coexistence of myoclonus and dystonia in the same body part with action might suggest the presence of an alternative mutation in patients with M-D.
Sharma, Pankaj; Rana, Dilbag Singh; Umar, Ahmad; Kumar, Ramesh; Chauhan, Mohinder Singh; Chauhan, Suvarcha
2016-06-01
Herein, we report the large-scale low-temperature aqueous solution based synthesis of hexagonal-shaped cadmium oxide (CdO) nanodisks. The synthesized nanodisks were characterized in detail to investigate the morphological, structural, optical and compositional properties using various analytical tools. The detailed characterizations revealed that the synthesized CdO nanodisks are grown in high-density, possessing well-crystallinity with cubic crystal phase and exhibiting good optical properties. Further, the prepared CdO nanodisks were used as efficient scaffold for cyanide ion sensor and photocatalyst applications. A luminescent sensor for the determination of cyanide ion in aqueous solution was fabricated based on synthesized CdO nanodisks. The fabricated luminescent sensor exhibited an extremely low detection limit (~1.40μmolL(-1)) towards cyanide ion which is significantly lower than the maximum permitted value of cyanide ion by United States Environmental Protection Agency (EPA) for drinking water (7.69μmolL(-1)). The interference studies of the fabricated sensor also demonstrate excellent selectivity towards cyanide ions compared to other coexisting ions. As a photocatalyst, the synthesized CdO nanodisks exhibited high photodegradation (~99.7%) of toxic methyl orange dye just in 90min using 0.25g of CdO nanodisks. Copyright © 2016 Elsevier B.V. All rights reserved.
Lahav, N
1975-08-05
The formation of packets of parallel oriented platelets and separating distances of several angstrom units in montmorillonite-water systems produces an intrinsic inhomogeneity with respect to the proton donating power of internal and external zones. Stable packets can be induced by both inorganic and organic molecules or ions, in suspensions or in drying-out systems. The coexistence of zones with different proton donating power was demonstrated by the pH-sensitive color reaction of benzidine, where stable packets of montmorillonite platelets were formed by the use of either paraquat or diquat. The close proximity of the two types of zones, which can be of the order of several angstroms, produces the conditions which were defined by Katchalsky as essential for the polymerization of amino acids. Since these enviromental conditions are quite common in nature, both at present and in prebiotic times, it is proposed that the inhomogeneity of clay-water systems with respect to proton donating power should be taken into account in both theoretical and experimental efforts to demonstrate the catalytic activity of clays in prebiotic synthesis.
Altoos, Rola; Carr, Robert; Chung, Jonathan; Stern, Eric; Nevrekar, Dipti
2015-01-01
This is a pictorial essay in which we review and illustrate a variety of thoracic injuries related to blunt trauma. Non-aortic blunt thoracic trauma can be divided anatomically into injuries of the chest wall, lungs, pleura, mediastinum, and diaphragm. Some injuries involve more than one anatomic compartment, and multiple injuries commonly coexist. This article provides common imaging findings and discussion of both common and uncommon but critical thoracic injuries encountered. Published by Elsevier Inc.
Qu, Guangzhou; Kou, Liqing; Wang, Tiecheng; Liang, Dongli; Hu, Shibin
2017-10-01
An activated carbon fiber supported nanoscale zero-valent iron (ACF-nZVI) composite for Cr(VI) removal from groundwater was synthesized according to the liquid phase reduction method. The techniques of N 2 adsorption/desorption, FESEM, EDX, XRD and XPS were used to characterize the ACF-nZVI composite and the interaction between the ACF-nZVI composite and Cr(VI) ions. Batch experiments were conducted to evaluate the effects of several factors, including the amount of nZVI on activated carbon fiber (ACF), pH value, initial Cr(VI) concentration, and co-existing ions on Cr(VI) removal. The results indicate that presence of ACF can inhibit the aggregation of nanoscale zero-valent iron (nZVI) particles and increase its reactivity, and the Cr(VI) removal efficiency increases with increasing amounts of nZVI on ACF and a decrease in the initial Cr(VI) concentration. In acidic conditions, almost 100% of Cr(VI) in solution can be removed after 60 min of reaction, and the removal efficiency decreases with increasing initial pH values. The Cr(VI) removal is also dependent on the co-existing ions. Reusability experiments on ACF-nZVI demonstrate that the ACF-nZVI composite can keep a high reactivity after five successive reduction cycles. The removal mechanisms are proposed as a two-step interaction including the physical adsorption of Cr(VI) on the surface or inner layers of the ACF-nZVI composite and the subsequent reduction of Cr(VI) to Cr(III) by nZVI. Copyright © 2017 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Zeng, Xianzhong; Gu, Yonggeng
2018-03-01
This paper deals with a ratio-dependent predator-prey system with the crowing term and the weak growth in the prey equation. Under the condition that the coefficient λ is less than a critical value λ1D (Ω0), we obtain existence of multiple positive steady state solutions of the predator-prey system and the dynamical behaviors of its positive solutions. Our results show that the predator and the prey possess not only the common coexistence, but also the very weak coexistence which both of the predator and the prey are very low. Meantime, the persistence of the positive solutions for the corresponding parabolic type system sometime depends strictly on the ratio of its initial data. Therefore, our results may be used to explain some special phenomena which under some bad environment, the predator and the prey may still coexist.
Wu, Shaogui
2017-06-01
Two magnesium ions play important roles in nucleotide addition cycle (NAC) of gene transcription. However, at the end of each NAC, why does one ion stay in the active site while the other ion leaves with product pyrophosphate (PP i )? This problem still remains obscure. In this work, we studied the problem using all-atom molecular dynamics simulation combined with steered molecular dynamics and umbrella sampling simulation methods. Our simulations reveal that although both ions are located in the active site after chemistry, their detailed positions are not symmetrical, leading to their different forces from surrounding groups. One ion makes weaker contacts with PP i than the whole protein. Hence, PP i release is less likely to take it away. The other one forms tighter contacts with PP i relative to the protein. The formed (Mg 2+ -PP i ) 2- complex is found to break the contacts with surrounding protein residues one by one so as to dissociate from the active site. This effectively avoids the coexistence of two ions in the active site after PP i release and guarantees a reasonable Mg 2+ ion number in the active site for the next NAC. The observations from this work can provide valuable information for comprehensively understanding the molecular mechanism of transcription. Proteins 2017; 85:1002-1007. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
ISFM guidelines on population management and welfare of unowned domestic cats (Felis catus).
Sparkes, Andrew H; Bessant, Claire; Cope, Kevin; Ellis, Sarah L H; Finka, Lauren; Halls, Vicky; Hiestand, Karen; Horsford, Kim; Laurence, Christopher; MacFarlaine, Ian; Neville, Peter F; Stavisky, Jenny; Yeates, James
2013-09-01
GUIDELINES RATIONALE: Cats are among the most commonly kept domestic pets, and coexist with humans in a variety of different circumstances. Cats are sentient beings and, as such, humans have a responsibility for cat welfare where humans and cats coexist. Because cats reproduce efficiently, measures to control populations are frequently needed, but these should be based on ethical and humane approaches. These consensus guidelines from the International Society of Feline Medicine's Welfare Advisory Panel provide a framework for the approach to welfare and population control measures, primarily among unowned cats and those going through a homing programme.
Heterogeneous to homogeneous melting transition visualized with ultrafast electron diffraction
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
The ultrafast laser excitation of matters leads to non-equilibrium states with complex solid-liquid phase transition dynamics. We used electron diffraction at mega-electronvolt energies to visualize the ultrafast melting of gold on the atomic scale length. For energy densities approaching the irreversible melting regime, we first observed heterogeneous melting on time scales of 100 ps to 1000 ps, transitioning to homogeneous melting that occurs catastrophically within 10-20 ps at higher energy densities. We showed evidence for the heterogeneous coexistence of solid and liquid. We determined the ion and electron temperature evolution and found superheated conditions. Our results constrain the electron-ion couplingmore » rate, determine the Debye temperature and reveal the melting sensitivity to nucleation seeds.« less
Antagonistic and synergistic interactions among predators.
Huxel, Gary R
2007-08-01
The structure and dynamics of food webs are largely dependent upon interactions among consumers and their resources. However, interspecific interactions such as intraguild predation and interference competition can also play a significant role in the stability of communities. The role of antagonistic/synergistic interactions among predators has been largely ignored in food web theory. These mechanisms influence predation rates, which is one of the key factors regulating food web structure and dynamics, thus ignoring them can potentially limit understanding of food webs. Using nonlinear models, it is shown that critical aspects of multiple predator food web dynamics are antagonistic/synergistic interactions among predators. The influence of antagonistic/synergistic interactions on coexistence of predators depended largely upon the parameter set used and the degree of feeding niche differentiation. In all cases when there was no effect of antagonism or synergism (a ( ij )=1.00), the predators coexisted. Using the stable parameter set, coexistence occurred across the range of antagonism/synergism used. However, using the chaotic parameter strong antagonism resulted in the extinction of one or both species, while strong synergism tended to coexistence. Whereas using the limit cycle parameter set, coexistence was strongly dependent on the degree of feeding niche overlap. Additionally increasing the degree of feeding specialization of the predators on the two prey species increased the amount of parameter space in which coexistence of the two predators occurred. Bifurcation analyses supported the general pattern of increased stability when the predator interaction was synergistic and decreased stability when it was antagonistic. Thus, synergistic interactions should be more common than antagonistic interactions in ecological systems.
Kim, Eui Young; Kim, Won Gu; Kim, Won Bae; Kim, Tae Yong; Kim, Jung Min; Ryu, Jin-Sook; Hong, Suck Joon; Gong, Gyungyub; Shong, Young Kee
2009-10-01
The effect of coexistent chronic lymphocytic thyroiditis (CLT) on prognosis in papillary thyroid carcinoma (PTC) patients remains controversial. We evaluated the influence of coexistent CLT on prognostic outcome and the association of coexistent CLT with clinicopathological parameters. A retrospective study with a median follow-up of 70 months. Patients with PTC who underwent total thyroidectomy followed by (131)I remnant ablation between 1995 and 2003 at Asan Medical Center, Seoul, Korea were enrolled. CLT was diagnosed histopathologically. Among 1441 patients, 214 (14.9%) had coexistent CLT. A greater female preponderance was noted in the patients with CLT compared with those without CLT (P < 0.01). Mean tumour size in the patients with CLT was smaller than that in patients without CLT (2.0 +/- 1.2 vs. 2.2 +/- 1.4 cm; P = 0.02). One hundred and fifty-one (12.3%) patients without CLT had recurrence, whereas 14 (7.1%) patients with CLT had recurrence during the follow-up period (P = 0.016). In patients with cervical lymph node metastases, those with coexistent CLT showed a significantly lower recurrence rate than those without CLT (P = 0.012). However, this association was lost on multivariate analysis adjusting for other clinicopathological predictors for recurrence. In this study, CLT was commonly associated with PTC and was associated with smaller size of the primary tumour at presentation. CLT was also associated with a reduced risk of recurrence during follow-up, although this was not significant after adjustment for other prognostic factors.
The Private Lives of Minerals: Social Network Analysis Applied to Mineralogy and Petrology
NASA Astrophysics Data System (ADS)
Hazen, R. M.; Morrison, S. M.; Fox, P. A.; Golden, J. J.; Downs, R. T.; Eleish, A.; Prabhu, A.; Li, C.; Liu, C.
2016-12-01
Comprehensive databases of mineral species (rruff.info/ima) and their geographic localities and co-existing mineral assemblages (mindat.org) reveal patterns of mineral association and distribution that mimic social networks, as commonly applied to such varied topics as social media interactions, the spread of disease, terrorism networks, and research collaborations. Applying social network analysis (SNA) to common assemblages of rock-forming igneous and regional metamorphic mineral species, we find patterns of cohesion, segregation, density, and cliques that are similar to those of human social networks. These patterns highlight classic trends in lithologic evolution and are illustrated with sociograms, in which mineral species are the "nodes" and co-existing species form "links." Filters based on chemistry, age, structural group, and other parameters highlight visually both familiar and new aspects of mineralogy and petrology. We quantify sociograms with SNA metrics, including connectivity (based on the frequency of co-occurrence of mineral pairs), homophily (the extent to which co-existing mineral species share compositional and other characteristics), network closure (based on the degree of network interconnectivity), and segmentation (as revealed by isolated "cliques" of mineral species). Exploitation of large and growing mineral data resources with SNA offers promising avenues for discovering previously hidden trends in mineral diversity-distribution systematics, as well as providing new pedagogical approaches to teaching mineralogy and petrology.
Toscano, Benjamin J; Hin, Vincent; Rudolf, Volker H W
2017-11-01
Predators often exert strong top-down regulation of prey, but in many systems, juvenile predators must compete with their future prey for a shared resource. In such life-history intraguild predation (LHIGP) systems, prey can therefore also regulate the recruitment and thus population dynamics of their predator via competition. Theory predicts that such stage-structured systems exhibit a wide range of dynamics, including alternative stable states. Here we show that cannibalism is an exceedingly common interaction within natural LHIGP systems that determines what coexistence states are possible. Using a modeling approach that simulates a range of ontogenetic diet shift scenarios along a productivity gradient, we demonstrate that only if the predator is competitively dominant can cannibalism promote coexistence by allowing prey to persist. If the prey is competitively dominant, cannibalism instead results in competitive exclusion of the predator and the loss of potential alternative stable states. Further, predator exclusion occurs at low cannibalistic preference relative to empirical estimates and is consistent across LHIGP systems in which the predator undergoes a complete diet shift or diet broadening over ontogeny. Given that prey is frequently competitively dominant in natural systems, our results demonstrate that even weak cannibalism can inhibit predator persistence, prompting exploration of mechanisms that reconcile theory with the common occurrence of such interactions in nature.
Zhou, Na; Li, Jinhua; Chen, Hao; Liao, Chunyang; Chen, Lingxin
2013-02-21
A simple and sensitive electrochemical assay strategy of stripping voltammetry for mercury ions (Hg(2+)) detection is described based on the synergistic effect between ionic liquid functionalized graphene oxide (GO-IL) and gold nanoparticles (AuNPs). The AuNPs-GO-IL modified onto glassy carbon electrode (GCE) resulted in highly enhanced electron conductive nanostructured membrane and large electroactive surface area, which was excellently examined by scanning electron microscopy and cyclic voltammetry. After accumulating Hg(2+), anodic stripping voltammetry (ASV) was performed, and differential pulse voltammetry (DPV) was employed for signal recording of Hg(2+). Several main experimental parameters were optimized, i.e., deposition potential and time of AuNPs were -0.2 V and 180 s, respectively, and accumulation potential and time of Hg(2+) were -0.3 V and 660 s, respectively. Under the optimal conditions, this AuNPs-GO-IL-GCE sensor attained a good linearity in a wide range of 0.1-100 nM (R = 0.9808) between the concentration of the Hg(2+) standard and peak current. The limit of detection was estimated to be 0.03 nM at a signal-to-noise ratio of 3σ. A variety of common coexistent ions in water samples were investigated, showing no obvious interferences on the Hg(2+) detection. The practical application of the proposed sensor has been carried out and demonstrated as feasible for determination of trace levels of Hg(2+) in drinking and environmental water samples.
Origins and Widespread Distribution of Co-existing Polyploids in Arnica cordifolia (Asteraceae)
Kao, Rebecca Hufft
2008-01-01
Background and Aims Polyploidy is a central force structuring genetic diversity in angiosperms, but its ecological significance and modes of origin are not fully understood. This work investigated the patterns of coexistence and molecular relatedness of polyploids in the perennial herb, Arnica cordifolia. Methods The local- and broad-scale distributions of cytotypes were analysed using flow cytometry. Samples were collected from both roadside and understorey habitats to test the hypothesis of niche separation between triploids and tetraploids. The nuclear rDNA internal transcribed spacer (ITS) and plastid rpl16 spacer, trnL intron plus trnL-trnF spacer and trnK 3' intron regions were sequenced. Key Results Broad-scale sampling established that both triploids and tetraploids were common throughout the range of the species, pentaploids were rare, and diploids were not found. Local-scale sampling revealed coexistence of both triploids and tetraploids within the majority of sites. Triploids and tetraploids were equally represented in the understorey and roadside habitat. Triploids were more variable than tetraploids, but both cytotypes shared polymorphisms in ITS. Conclusions Coexistence of cytotypes appears to be the norm in A. cordifolia, but habitat differentiation (roadside vs. understorey) is not supported as a coexistence mechanism. Molecular analyses supported multiple events creating triploids but revealed a lack of variation in the tetraploids. Additionally, sequence polymorphisms in ITS suggested a hybridization event prior to polyploidization. PMID:17993653
Origins and widespread distribution of co-existing Polyploids in Arnica cordifolia (Asteraceae).
Kao, Rebecca Hufft
2008-01-01
Polyploidy is a central force structuring genetic diversity in angiosperms, but its ecological significance and modes of origin are not fully understood. This work investigated the patterns of coexistence and molecular relatedness of polyploids in the perennial herb, Arnica cordifolia. The local- and broad-scale distributions of cytotypes were analysed using flow cytometry. Samples were collected from both roadside and understorey habitats to test the hypothesis of niche separation between triploids and tetraploids. The nuclear rDNA internal transcribed spacer (ITS) and plastid rpl16 spacer, trnL intron plus trnL-trnF spacer and trnK 3' intron regions were sequenced. Broad-scale sampling established that both triploids and tetraploids were common throughout the range of the species, pentaploids were rare, and diploids were not found. Local-scale sampling revealed coexistence of both triploids and tetraploids within the majority of sites. Triploids and tetraploids were equally represented in the understorey and roadside habitat. Triploids were more variable than tetraploids, but both cytotypes shared polymorphisms in ITS. Coexistence of cytotypes appears to be the norm in A. cordifolia, but habitat differentiation (roadside vs. understorey) is not supported as a coexistence mechanism. Molecular analyses supported multiple events creating triploids but revealed a lack of variation in the tetraploids. Additionally, sequence polymorphisms in ITS suggested a hybridization event prior to polyploidization.
Shibasaki, Shota; Shirokawa, Yuka; Shimada, Masakazu
2017-05-21
Biological studies of the evolution of cooperation are challenging because this process is vulnerable to cheating. Many mechanisms, including kin discrimination, spatial structure, or by-products of self-interested behaviors, can explain this evolution. Here we propose that the evolution of cooperation can be induced by other cooperation. To test this idea, we used a model organism Dictyostelium discoideum because it exhibits two cooperative dormant phases, the fruiting body and the macrocyst. In both phases, the same chemoattractant, cyclic AMP (cAMP), is used to collect cells. This common feature led us to hypothesize that the evolution of macrocyst formation would be induced by coexistence with fruiting bodies. Before forming a mathematical model, we confirmed that macrocysts coexisted with fruiting bodies, at least under laboratory conditions. Next, we analyzed our evolutionary game theory-based model to investigate whether coexistence with fruiting bodies would stabilize macrocyst formation. The model suggests that macrocyst formation represents an evolutionarily stable strategy and a global invader strategy under this coexistence, but is unstable if the model ignores the fruiting body formation. This result indicates that the evolution of macrocyst formation and maintenance is attributable to coexistence with fruiting bodies. Therefore, macrocyst evolution can be considered as an example of evolution of cooperation induced by other cooperation. Copyright © 2017 Elsevier Ltd. All rights reserved.
Dickman, Amy J; Macdonald, Ewan A; Macdonald, David W
2011-08-23
One of the greatest challenges in biodiversity conservation today is how to facilitate protection of species that are highly valued at a global scale but have little or even negative value at a local scale. Imperiled species such as large predators can impose significant economic costs at a local level, often in poverty-stricken rural areas where households are least able to tolerate such costs, and impede efforts of local people, especially traditional pastoralists, to escape from poverty. Furthermore, the costs and benefits involved in predator conservation often include diverse dimensions, which are hard to quantify and nearly impossible to reconcile with one another. The best chance of effective conservation relies upon translating the global value of carnivores into tangible local benefits large enough to drive conservation "on the ground." Although human-carnivore coexistence involves significant noneconomic values, providing financial incentives to those affected negatively by carnivore presence is a common strategy for encouraging such coexistence, and this can also have important benefits in terms of reducing poverty. Here, we provide a critical overview of such financial instruments, which we term "payments to encourage coexistence"; assess the pitfalls and potentials of these methods, particularly compensation and insurance, revenue-sharing, and conservation payments; and discuss how existing strategies of payment to encourage coexistence could be combined to facilitate carnivore conservation and alleviate local poverty.
Hu, Shan; Shi, Qiantao; Jing, Chuanyong
2015-08-18
A pressing challenge in arsenic (As) adsorptive filtration is to decipher how the As atomic surface structure obtained in the laboratory can be used to accurately predict the field filtration cycle. The motivation of this study was therefore to integrate molecular level As adsorption mechanisms and capacities to predict effluent As from granular TiO2 columns in the field as well as its health impacts. Approximately 2,955 bed volumes of groundwater with an average of 542 μg/L As were filtered before the effluent As concentration exceeded 10 μg/L, corresponding to an adsorption capacity of 1.53 mg As/g TiO2. After regeneration, the TiO2 column could treat 2,563 bed volumes of groundwater, resulting in an As load of 1.36 mg/g TiO2. Column filtration and EXAFS results showed that among coexisting ions present in groundwater, only Ca(2+), Si(OH)4, and HCO3(-) would interfere with As adsorption. The compound effects of coexisting ions and molecular level structural information were incorporated in the PHREEQC program to satisfactorily predict the As breakthrough curves. The total urinary As concentration from four volunteers of local residences, ranging from 972 to 2,080 μg/L before groundwater treatment, decreased to the range 31.7-73.3 μg/L at the end of the experimental cycle (15-33 days).
ERIC Educational Resources Information Center
Reay, Diane
2011-01-01
This short paper is a response to Nel Noddings's article on schooling for democracy. Whilst agreeing with the basic premises of Noddings's argument, it questions the possibility of parity between academic and vocational tracks given the inequitable social and educational contexts the two types of learning would have to coexist within. Drawing on…
Multiple Sclerosis/Chronic Fatigue Syndrome overlap: When two common disorders collide.
Gaber, Tarek A-Z K; Oo, Wah Wah; Ringrose, Hollie
2014-01-01
Fatigue is a major cause of disability and handicap in Multiple Sclerosis (MS) patients. The management of this common problem is often difficult. Chronic Fatigue Syndrome (CFS/ME) is another common cause of fatigue which is prevalent in the same population of middle aged females commonly affected by MS. This report aims at examining the potential coexistence of MS and CFS/ME in the same patients. This is a retrospective study examining a cohort of MS patients referred for rehabilitation. The subjects were screened for CFS/ME symptoms. Sixty-four MS patients (43 females) were screened for CFS/ME. Nine patients (14%) with a mean age 52 (SD 9.7) who were all females fulfilled the Fukuda criteria for diagnosis of CFS/ME. Their symptoms, including muscular and joint pain, malaise and recurrent headaches, were not explained by the pattern of their MS. MS and CFS/ME are two common conditions with increased prevalence in middle aged females. As the diagnosis of CFS/ME is clinical with no positive clinical signs or investigations; it can be made with difficulty in the presence of another clear explanation for the disabling fatigue. Our results suggest that the two conditions may co-exist. Considering CFS/ME as a potential co-morbidity may lead to more focused and appropriate management.
Coexistence of bilateral first and second branchial arch anomalies
Thakur, J S; Shekar, Vidya; Saluja, Manika; Mohindroo, N K
2013-01-01
Branchial arch anomalies are one of the most common congenital anomalies that are usually unilateral and bilateral presentation is rare. The simultaneous presence of bilateral second branchial arch anomalies along with bilateral first arch anomalies is extremely rare, with only three such cases reported in the literature. We present two non-syndromic cases of coexisting bilateral first and second arch anomalies. Developmental anomalies of the branchial apparatus account for 17% of all paediatric cervical masses and are the most common type of congenital cervical mass. They usually present in the paediatric age group. About 96–97% of these anomalies are unilateral. Bilateral presentation is seen in 2–3% having a strong familial association. Congenital syndromes also have been associated with first and second branchial arch anomalies. Thorough clinical examination and investigations should be done to rule out these syndromes. PMID:23580675
Huang, Ying; Yang, Fei; Ai, Luoyan; Feng, Min; Wang, Chi; Wang, Zhaohui; Liu, Jianshe
2017-07-01
A large amount of chloride and ammonium ions were produced and released from industrial processes with non-biodegradable organic pollutants to affect efficiencies of advanced oxidation processes (AOPs). Here, the influences of chloride and ammonium ions on Co/peroxymonosulfate (Co/PMS) reaction system, a widely used AOPs to produce sulfate radicals, were investigated by examining the degradation efficiency of an azo dye (Acid Orange 7, AO7). The experimental results showed that a significant decrease in the degradation rate of AO7 was observed in the presence of NH 4 + , while a dual effect of chloride on AO7 bleaching appeared. The presence of NH 4 Cl was unfavorable for AO7 degradation at low concentration (<20 mM), whereas further addition of NH 4 Cl (>20 mM) apparently accelerated AO7 discoloration rate. The apparent effects of the two co-existing inorganic ions were determined by roles of the dominating ions at varied molar ratio of [NH 4 + ]/[Cl - ]. The present study may have technical implications for the treatment of industrial wastewater containing diverse ions in practice. Copyright © 2017 Elsevier Ltd. All rights reserved.
Bao, Shuangyou; Tang, Lihong; Li, Kai; Ning, Ping; Peng, Jinhui; Guo, Huibin; Zhu, Tingting; Liu, Ye
2016-01-15
Amino-functionalized Fe3O4@SiO2 magnetic nano-adsorbent was used as a novel sorbent to highly selective removal of Zn(II) ion from hot-dip galvanizing pickling waste in the presence of Fe(II). These hot-dip galvanizing pickling waste mainly contain ZnCl2 and FeCl2 in aqueous HCl media. The properties of this magnetic adsorbent were examined by transmission electron microscopy (TEM), powder X-ray diffraction (XRD), infrared spectrometer (FT-IR) and BET surface area measurements. Various factors influencing the adsorption of Zn(II) ion such as initial concentration of metal ions, the amount of adsorbent, pH value of the solutions, the concentration of coexisting iron ion were investigated by batch experiments. The results indicated that the adsorption equilibrium data obeyed the Freundlich model with maximum adsorption capacities for Zn(II) to 169.5mg/g. The maximum adsorption occurred at pH 5±0.1 and Fe(II) interferences had no obvious influence. This work provides a potential and unique technique for zinc ion removal from hot-dip galvanizing pickling waste. Copyright © 2015 Elsevier Inc. All rights reserved.
Zou, Yidong; Wang, Xiangxue; Khan, Ayub; Wang, Pengyi; Liu, Yunhai; Alsaedi, Ahmed; Hayat, Tasawar; Wang, Xiangke
2016-07-19
The presence of heavy metals in the industrial effluents has recently been a challenging issue for human health. Efficient removal of heavy metal ions from environment is one of the most important issues from biological and environmental point of view, and many studies have been devoted to investigate the environmental behavior of nanoscale zerovalent iron (NZVI) for the removal of toxic heavy metal ions, present both in the surface and underground wastewater. The aim of this review is to show the excellent removal capacity and environmental remediation of NZVI-based materials for various heavy metal ions. A new look on NZVI-based materials (e.g., modified or matrix-supported NZVI materials) and possible interaction mechanism (e.g., adsorption, reduction and oxidation) and the latest environmental application. The effects of various environmental conditions (e.g., pH, temperature, coexisting oxy-anions and cations) and potential problems for the removal of heavy metal ions on NZVI-based materials with the DFT theoretical calculations and EXAFS technology are discussed. Research shows that NZVI-based materials have satisfactory removal capacities for heavy metal ions and play an important role in the environmental pollution cleanup. Possible improvement of NZVI-based materials and potential areas for future applications in environment remediation are also proposed.
Xi, Long Fu; Edelstein, Zoe R; Meyers, Craig; Ho, Jesse; Cherne, Stephen L; Schiffman, Mark
2009-09-01
Infection with multiple human papillomavirus (HPV) types is common. However, it is unknown whether viral DNA load is related to the coexistence of other types. Study subjects were 802 and 303 women who were positive for HPV16 and HPV18, respectively, at enrollment into the Atypical Squamous Cells of Undetermined Significance and Low-Grade Squamous Intraepithelial Lesion Triage Study. HPV16 and HPV18 E7 copies per nanogram of cellular DNA in cervical swab samples were measured by real-time PCR in triplicate. Concurrent coinfection was common in this population of women with minor cervical lesions; multiple HPV types were detected in 573 (71.4%) of 802 HPV16-positive women and 227 (74.9%) of 303 HPV18-positive women. The adjusted odds ratio associating coinfection with per 1 log unit increase in HPV16 DNA load was 0.78 (95% confidence interval, 0.68-0.89); it was 0.64 (95% confidence interval, 0.52-0.79) for a similar analysis of HPV18 DNA load. Women with, compared with without, coinfection of A9 species types possessed a significantly lower HPV16 DNA load (P < 0.001), whereas women with, compared with without, coinfection of A7 species types possessed a significantly lower HPV18 DNA load (P = 0.001). A trend of decrease in HPV16 DNA load with increasing number of the coexisting non-HPV16 A9 species types was statistically significant (P(trend) = 0.001). Coinfection with other types was associated with lower HPV16 and HPV18 DNA load. The extent of reduction was correlated to phylogenetic distance of the coexisting types to HPV16 and HPV18, respectively.
Liu, Chuyang; Zhang, Yujing; Jia, Jingguo; Sui, Qiang; Ma, Ning; Du, Piyi
2015-01-01
Multiferroic ceramics with extraordinary susceptibilities coexisting are vitally important for the multi-functionality and integration of electronic devices. However, multiferroic composites, as the most potential candidates, will introduce inevitable interface deficiencies and thus dielectric loss from dissimilar phases. In this study, single-phased ferrite ceramics with considerable magnetic and dielectric performances appearing simultaneously were fabricated by doping target ions in higher valence than that of Fe3+, such as Ti4+, Nb5+ and Zr4+, into BaFe12O19. In terms of charge balance, Fe3+/Fe2+ pair dipoles are produced through the substitution of Fe3+ by high-valenced ions. The electron hopping between Fe3+ and Fe2+ ions results in colossal permittivity. Whilst the single-phased ceramics doped by target ions exhibit low dielectric loss naturally due to the diminishment of interfacial polarization and still maintain typical magnetic properties. This study provides a convenient method to attain practicable materials with both outstanding magnetic and dielectric properties, which may be of interest to integration and multi-functionality of electronic devices. PMID:25835175
Liu, Chuyang; Zhang, Yujing; Jia, Jingguo; Sui, Qiang; Ma, Ning; Du, Piyi
2015-04-02
Multiferroic ceramics with extraordinary susceptibilities coexisting are vitally important for the multi-functionality and integration of electronic devices. However, multiferroic composites, as the most potential candidates, will introduce inevitable interface deficiencies and thus dielectric loss from dissimilar phases. In this study, single-phased ferrite ceramics with considerable magnetic and dielectric performances appearing simultaneously were fabricated by doping target ions in higher valence than that of Fe(3+), such as Ti(4+), Nb(5+) and Zr(4+), into BaFe12O19. In terms of charge balance, Fe(3+)/Fe(2+) pair dipoles are produced through the substitution of Fe(3+) by high-valenced ions. The electron hopping between Fe(3+) and Fe(2+) ions results in colossal permittivity. Whilst the single-phased ceramics doped by target ions exhibit low dielectric loss naturally due to the diminishment of interfacial polarization and still maintain typical magnetic properties. This study provides a convenient method to attain practicable materials with both outstanding magnetic and dielectric properties, which may be of interest to integration and multi-functionality of electronic devices.
NASA Astrophysics Data System (ADS)
Liu, Chuyang; Zhang, Yujing; Jia, Jingguo; Sui, Qiang; Ma, Ning; Du, Piyi
2015-04-01
Multiferroic ceramics with extraordinary susceptibilities coexisting are vitally important for the multi-functionality and integration of electronic devices. However, multiferroic composites, as the most potential candidates, will introduce inevitable interface deficiencies and thus dielectric loss from dissimilar phases. In this study, single-phased ferrite ceramics with considerable magnetic and dielectric performances appearing simultaneously were fabricated by doping target ions in higher valence than that of Fe3+, such as Ti4+, Nb5+ and Zr4+, into BaFe12O19. In terms of charge balance, Fe3+/Fe2+ pair dipoles are produced through the substitution of Fe3+ by high-valenced ions. The electron hopping between Fe3+ and Fe2+ ions results in colossal permittivity. Whilst the single-phased ceramics doped by target ions exhibit low dielectric loss naturally due to the diminishment of interfacial polarization and still maintain typical magnetic properties. This study provides a convenient method to attain practicable materials with both outstanding magnetic and dielectric properties, which may be of interest to integration and multi-functionality of electronic devices.
NASA Astrophysics Data System (ADS)
Luo, Rui; Wu, Feng; Xie, Man; Ying, Yao; Zhou, Jiahui; Huang, Yongxin; Ye, Yusheng; Li, Li; Chen, RenJie
2018-04-01
Layered transition metal oxides are considered to be promising candidates as cathode materials for sodium-ion batteries. Herein, a facile solid-state reaction is developed to synthesize hexagons plate-like Na0.67Ni0.25Mn0.75O2+δ (denoted as P2-NNM) material with habit plane formed. The structure of this layered oxide is characterized by XRD, HR-TEM and SAED. The layered material delivers a high reversible capacity of 91.8 mAh g-1 at 0.2 C with a capacity retention of 94.4 % after 280 cycles, superior rate capability and long cycle life (84.2 % capacity retention after 1000 cycle). Ni2+ is an active ion and Ni doping alleviates the Jahn-Teller distortion, and Mn3+/Mn4+ coexist as Mn4+ is desired from the stability perspective. Particularly, CV and XPS results confirm these results. Moreover, the electrode exhibits a quasi-solid-solution reaction during the sodium extraction and insertion. This contribution demonstrates that P2-NNM is a promising cathode electrode for rechargeable long-life sodium-ion batteries.
CNTs grown on nanoporous carbon from zeolitic imidazolate frameworks for supercapacitors.
Kim, Jeonghun; Young, Christine; Lee, Jaewoo; Park, Min-Sik; Shahabuddin, Mohammed; Yamauchi, Yusuke; Kim, Jung Ho
2016-10-27
Carbon nanotubes (CNT) grown on nanoporous carbon (NPC), which yields coexisting amorphous and graphitic nanoarchitectures, have been prepared on a large scale from zeolitic imidazolate framework (ZIF) by introducing bimetallic ions (Co 2+ and Zn 2+ ). Interestingly, the hybrid Co/Zn-ZIF-derived NPC showed rich graphitic CNTs on the surface. This NPC was utilized for a coin-type supercapacitor cell with an aqueous electrolyte, which showed enhanced retention at high current density and good stability over 10 000 cycles.
Lin, Chung-King; Chen, Ling-Ping; Chang, Hsiu-Lin; Sung, Yung-Chuan
2014-08-01
Some physicians neglect the possible coexistence of an iron deficiency with a thalassemia minor and do not treat the iron deficiency accordingly. This motivated us to conduct this study. We retrospectively reviewed the records of 3892 patients who visited our clinics and had hemoglobin (Hb) electrophoreses performed in our hematologic laboratory from August 1, 2007 to December 31, 2012. The thalassemia minors were identified by characteristic complete blood count (CBC) parameters obtained from an autoanalyzer and Hb electrophoresis, and some cases were confirmed with molecular tests. Then, we checked iron studies [ferritin and/or serum iron with total iron-binding capacity (TIBC)] to determine the coexistence of an iron deficiency with a thalassemia minor and a response to iron, if such treatments were given. We found 792 cases with thalassemia minors, and excluded those without iron studies, with 661 cases as our sample. A total of 202/661 cases (31%) also had iron deficiencies. They had lower red blood cell (RBC) counts, Hb, and ferritin levels as compared to those thalassemia minor cases without coexistence of iron deficiencies. We concluded that the thalassemia minor patients did not have iron overload complications in our population. On the contrary, iron deficiencies commonly coexist in the clinical visits. We propose that if Hb < 11.5 g/dL in a case of thalassemia minor, one should screen for iron deficiency simultaneously. The sensitivity is 79.8% and the specificity is 82.6%. Therefore, physicians should be aware of this coexisting condition, and know how to recognize and treat it accordingly. Copyright © 2014. Published by Elsevier B.V.
Ogawara, Aoi; Harada, Makoto; Ichikawa, Tohru; Fujii, Kazuaki; Ehara, Takashi; Kobayashi, Mamoru
2017-12-01
Renal prognosis for anti-glomerular basement membrane (GBM) glomerulonephritis is poor. The greater the amount of anti-GBM antibody binding the antigen (type IV collagen of the glomerular basement membrane), the greater the number of crescents that develop in glomeruli, resulting in progression of renal impairment. Immunofluorescence staining reveals linear IgG depositions on glomerular capillary walls. Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome in middle-aged to elderly patients. Immune complex is deposited in the sub-epithelial space of the glomerulus resulting in the development of a membranous lesion. Immunofluorescence staining reveals granular IgG depositions on glomerular capillary walls. Coexisting anti-GBM glomerulonephritis and MN are rare and, here we report a case of coexisting anti-GBM glomerulonephritis and MN with preserved renal function. There are some cases of coexisting anti-GBM glomerulonephritis and MN do not show severely decreased renal function. A 76-year-old Japanese woman presented with nephrotic syndrome, microscopic hematuria, and was positive for anti-GBM antibody. Kidney biopsy revealed linear and granular IgG depositions in glomerular capillary walls, crescent formations, and electron-dense deposits in the sub-epithelial space. She was diagnosed with anti-GBM glomerulonephritis and MN. Steroid and cyclosporine therapy achieved complete remission, and kidney function was preserved. In conclusion, coexisting anti-GBM glomerulonephritis and MN can have preserved renal function. IgG subclass of deposited anti-GBM antibody may be associated with the severity of anti-GBM glomerulonephritis. In addition, in the case of nephrotic syndrome with hematuria, we should consider the possibility of coexisting anti-GBM glomerulonephritis and MN.
NASA Astrophysics Data System (ADS)
Huo, Xinming; Tang, Fei; Zhang, Xiaohua; Chen, Jin; Zhang, Yan; Guo, Cheng'an; Wang, Xiaohao
2016-10-01
The rectilinear ion trap (RIT) has gradually become one of the preferred mass analyzers for portable mass spectrometers because of its simple configuration. In order to enhance the performance, including sensitivity, quantitation capability, throughput, and resolution, a novel RIT mass spectrometer with dual pressure chambers was designed and characterized. The studied system constituted a quadrupole linear ion trap (QLIT) in the first chamber and a RIT in the second chamber. Two control modes are hereby proposed: Storage Quadrupole Linear Ion Trap-Rectilinear Ion Trap (SQLIT-RIT) mode, in which the QLIT was used at high pressure for ion storage and isolation, and the RIT was used for analysis; and Analysis Quadrupole Linear Ion Trap-Rectilinear Ion Trap (AQLIT-RIT) mode, in which the QLIT was used for ion storage and cooling. Subsequently, synchronous scanning and analysis were carried out by QLIT and RIT. In SQLIT-RIT mode, signal intensity was improved by a factor of 30; the limit of quantitation was reduced more than tenfold to 50 ng mL-1, and an optimal duty cycle of 96.4% was achieved. In AQLIT-RIT mode, the number of ions coexisting in the RIT was reduced, which weakened the space-charge effect and reduced the mass shift. Furthermore, the mass resolution was enhanced by a factor of 3. The results indicate that the novel control modes achieve satisfactory performance without adding any system complexity, which provides a viable pathway to guarantee good analytical performance in miniaturization of the mass spectrometer.
The survival of the conformist: social pressure and renewable resource management.
Tavoni, Alessandro; Schlüter, Maja; Levin, Simon
2012-04-21
This paper examines the role of other-regarding behavior as a mechanism for the establishment and maintenance of cooperation in resource use under variable social and environmental conditions. By coupling resource stock dynamics with social dynamics concerning compliance to a social norm prescribing non-excessive resource extraction in a common pool resource, we show that when reputational considerations matter and a sufficient level of social stigma affects the violators of a norm, sustainable outcomes are achieved. We find large parameter regions where norm-observing and norm-violating types coexist, and analyze to what extent such coexistence depends on the environment. Copyright © 2011 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Hervig, R. L.; Williams, L. B.
2011-12-01
Boron isotope fractionation depends strongly on the coordination of boron in coexisting phases. When boron is tetrahedrally coordinated in one phase and trigonally coordinated in another, equilibrium fractionation can record parameters such as temperature (over a surprisingly wide T for a stable isotope system) or the pH at which phases precipitated from low temperature solutions. The heavy isotope of B is strongly partitioned into fluid phases relative to minerals containing tetrahedrally-coordinated boron and thus B isotope ratios can provide evidence for separation of hydrous fluids from subducted materials and from silicate melts in volcanoes. However, in many cases, the B concentration of relevant solid phases is very low, leading to large errors in the isotope ratio. For example, common analytical protocols for the microanalysis of B on our secondary ion mass spectrometer (SIMS, Cameca 6f) use an O- primary beam, and detection of positive secondary ions at moderate mass resolving power. On samples containing a few ppm B, analyses may require up to ~2 hours to give integrated signals corresponding to errors of +/- 7 per mil (2 sigma). Increases in ion intensity would result from simply increasing the primary current (at the expense of beam diameter) or increasing transmission by reducing mass resolving power (at the expense of including 10BH+ ions on the 11B+ peak). Large magnetic sector SIMS instruments achieve higher transmission at high resolution, but the challenges of obtaining desired precision (+/- 1 permil) remain when boron is present at <2 ppm levels. Another direction to pursue is to find a B-containing ion that is formed more readily than the elemental positive ion. The logical choice is BO-, an ion isoelectronic with F-, and one we would expect to show very high ion yields. However, BO- can be unpleasant to deal with. Isobaric interferences include the toxic species of CN-: various combinations of the two carbon and nitrogen isotopes are silent but deadly additions to the mass spectrum requiring mass resolving powers exceeding 12000 (M/ΔM) for complete separation. In our preliminary studies, we have used a Cs+ primary beam, detection of negative secondary ions and the normal-incidence electron gun for neutralizing positive charge build-up in the crater. The observation of abundant carbon and nitrogen in clay mineral samples reveal the challenges of conducting these analyses. However, carbon and nitrogen contents in other phases of interest are very low, and contaminants can be controlled using careful sample preparation, ultra-high vacuum conditions, and restricting secondary ion detection to the central part of the analyzed crater. Using these conditions, BO- reeks with intensities up to 100x the elemental negative ion! Through a lot of sweat equity, we will demonstrate the use and limitations of BO- in isotope microanalyses of low-B samples. We thank the NSF EAR Instruments and Facilities program for encouraging us to explore new analytical techniques.
NASA Astrophysics Data System (ADS)
Liu, Bing; Xu, G. Q.; Gan, L. M.; Chew, C. H.; Li, W. S.; Shen, Z. X.
2001-01-01
Spherical and uniform CdS nanoclusters were synthesized by hydrothermal microemulsion. The reaction of Cd2+ ions with S2- ions generated from the decomposition of thioacetamide proceeded in water microdroplets. The mean diameter of the CdS nanoclusters can be varied from 20 to 80 nm by increasing the reaction temperature from 30 to 120 °C. XRD results indicate that the resulting CdS nanoclusters have a reduced and distorted hexagonal lattice compared to bulk materials. Two intense luminescence bands, i.e., green and red, were observed to coexist in the CdS nanoclusters. Their peak positions and relative intensities were found to be sensitive to the size and structure of nanoclusters. These emissions are attributed to surface defects (green emission) and the Cd-Cl composite vacancies (red emission).
Soave, P M; Conti, G; Costa, R; Arcangeli, A
2009-08-01
to review current knowledge concerning the use of magnesium in anesthesiology, the role of hypomagnesemia and hypermagnesemia in perioperative period, analyzing the cardiologic problems related to blood serum concentration changes of magnesium that can interesting in primis the anaesthesist in perioperative period. References were obtained from Pubmed (1995 to 2009). All categories of articles were selected, such as reviews, meta-analyses, s, clinical trials etc). Magnesium is a bivalent ion, like calcium, the fourth most common cation in the body, and the second most common intracellular cation after potassium. Magnesium deficiency has been demonstrated in 7-11% of the hospitalized patients and it has been found to coexist with other electrolyte disorders, particulary hypokalaemia or hypophosphatemia and, to a less extent, hyponatraemia and hypocalcaemia, in more than 40% of patients. Hypomagnesemia needs to be detected and corrected to prevent increased morbidity and mortality. Historically, magnesium sulphate has been proposed as a general anaesthetic. Magnesium reduces the catecholamine release during the stressful manouvres like intubation. Magnesium has also anti-nociceptive effects in animal and human models of pain by blocking the N-methyl-D-aspartate receptor and the associated ion channels and thus preventing central sensitization caused by peripheral nociceptive stimulation. So for some authors it reduces the need for intraoperative anesthetics and relaxant drugs and reduces the amount of morphine for the treatment of pospoperative pain. The use of magnesium is extended not only to general anaesthesia but also in loco-regional anaesthesia. The role of magnesium has been extensively studied in cardiology especially during myocardial infarction, arrhythmia and cardiac surgery. Recent studies show the important of magnesium to prevent the postoperative neurocognitive impairment during carotid endoarterectomy and its utility in treatment of severe asthma. Magnesium has many known indications. In peioperative period blood serum concentration changes of magnesium are frequent so anesthesiologists need to know the role of this important cation.
Coexistence of three specialist aphids on common milkweed, Asclepias syriaca.
Smith, R A; Mooney, K A; Agrawal, A A
2008-08-01
Coexistence of host-specific herbivores on plants is believed to be governed by interspecific interactions, but few empirical studies have systematically unraveled these dynamics. We investigated the role of several factors in promoting coexistence among the aphids Aphis nerii, Aphis asclepiadis, and Myzocallis asclepiadis that all specialize on common milkweed (Asclepias syriaca). Competitive exclusion is thought to occur when interspecific competition is stronger than intraspecific competition. Consequently, we investigated whether predators, mutualists, or resource quality affected the strength of intra- vs. interspecific competition among aphids in factorial manipulations of competition with exposure to predation, ants, and variable plant genotypes in three separate experiments. In the predation x competition experiment, predators reduced aphid per capita growth by 66%, but the strength of intra- and interspecific competition did not depend on predators. In the ants x competition experiment, ants reduced per capita growth of A. nerii and M. asclepiadis (neither of which were mutualists with ants) by approximately one-half. In so doing, ants ameliorated the negative effects of these competitors on ant-tended A. asclepiadis by two-thirds, representing a novel benefit of ant-aphid mutualism. Nevertheless, ants alone did not explain the persistence of competitively inferior A. asclepiadis as, even in the presence of ants, interspecific competition remained stronger than intraspecific competition. In the plant genotype x competition experiment, both A. asclepiadis and M. asclepiadis were competitively inferior to A. nerii, with the strength of interspecific competition exceeding that of intraspecific competition by 83% and 23%, respectively. Yet these effects differed among milkweed genotypes, and there were one or more plant genotypes for each aphid species where coexistence was predicted. A synthesis of our results shows that predators play little or no role in preferentially suppressing competitively dominant A. nerii. Nonetheless, A. asclepiadis benefits from ants, and A. asclepiadis and M. asclepiadis may escape competitive exclusion by A. nerii on select milkweed genotypes. Taken as a whole, the coexistence of three host-specific aphid species sharing the same resource was promoted by the dual action of ants as antagonists and mutualists and by genetic diversity in the plant population itself.
NASA Astrophysics Data System (ADS)
Zhu, Te; Jin, Shuoxue; Zhang, Peng; Song, Ligang; Lian, Xiangyu; Fan, Ping; Zhang, Qiaoli; Yuan, Daqing; Wu, Haibiao; Yu, Runsheng; Cao, Xingzhong; Xu, Qiu; Wang, Baoyi
2018-07-01
The formation of helium bubble precursors, i.e., helium-vacancy complexes, was investigated for Fe9Cr alloy, which was uniformly irradiated by using 100 keV helium ions with fluences up to 5 × 1016 ions/cm2 at RT, 523, 623, 723, and 873 K. Helium-irradiation-induced microstructures in the alloy were probed by positron annihilation technique. The results show that the ratio of helium atom to vacancy (m/n) in the irradiation induced HemVn clusters is affected by the irradiation temperature. Irradiated at room temperature, there is a coexistence of large amounts of HemV1 and mono-vacancies in the sample. However, the overpressured HemVn (m > n) clusters or helium bubbles are easily formed by the helium-filled vacancy clusters (HemV1 and HemVn (m ≈ n)) absorbing helium atoms when irradiated at 523 K and 823 K. The results also show that void swelling of the alloy is the largest under 723 K irradiation.
Influence of Au ions irradiation damage on helium implanted tungsten
NASA Astrophysics Data System (ADS)
Kong, Fanhang; Qu, Miao; Yan, Sha; Cao, Xingzhong; Peng, Shixiang; Zhang, Ailin; Xue, Jianming; Wang, Yugang; Zhang, Peng; Wang, Baoyi
2017-10-01
The damages of implanted helium ions together with energetic neutrons in tungsten is concerned under the background of nuclear fusion related materials research. Helium is lowly soluble in tungsten and has high binding energy with vacancy. In present work, noble metal Au ions were used to study the synergistic effect of radiation damage and helium implantation. Nano indenter and the Doppler broaden energy spectrum of positron annihilation analysis measurements were used to research the synergy of radiation damage and helium implantation in tungsten. In the helium fluence range of 4.8 × 1015 cm-2-4.8 × 1016 cm-2, vacancies played a role of trappers only at the very beginning of bubble nucleation. The size and density is not determined by vacancies, but the effective capture radius between helium bubbles and scattered helium atoms. Vacancies were occupied by helium bubbles even at the lowest helium fluence, leaving dislocations and helium bubbles co-exist in tungsten materials.
Optical properties of 3d transition-metal-doped MgAl2O4 spinels
NASA Astrophysics Data System (ADS)
Izumi, K.; Miyazaki, S.; Yoshida, S.; Mizokawa, T.; Hanamura, E.
2007-08-01
Strong emission bands in the visible region are observed in MgAl2O4 crystals doped with transition-metal ions under excitation at the band-to-band transitions. We report optical responses of Cr-, Co-, and Ni-doped MgAl2O4 and present optical models for M -doped MgAl2O4 ( M=Ti , V, Cr, Mn, Co, and Ni) to describe the charge-transfer transitions and the transitions between multiplet levels of 3d electrons, which are observed competitively or coexisting, depending on the number of 3d electrons. While the optical responses of Cr- and Ni-doped MgAl2O4 are dominated by the multiplet-multiplet transitions, those of Ti- and V-doped MgAl2O4 are governed by the charge-transfer transitions. The two kinds of transitions coexist in the Mn- and Co-doped MgAl2O4 . These behaviors are well understood based on the numerical results of unrestricted Hartree-Fock approximation.
Biosorption of copper(II) from aqueous solutions by green alga Cladophora fascicularis.
Deng, Liping; Zhu, Xiaobin; Wang, Xinting; Su, Yingying; Su, Hua
2007-08-01
Biosorption is an effective means of removal of heavy metals from wastewater. In this work the biosorption behavior of Cladophora fascicularis was investigated as a function of pH, amount of biosorbent, initial Cu2+ concentration, temperature, and co-existing ions. Adsorption equilibria were well described by Langmuir isotherm models. The enthalpy change for the biosorption process was found to be 6.86 kJ mol(-1) by use of the Langmuir constant b. The biosorption process was found to be rapid in the first 30 min. The presence of co-existing cations such as Na+, K+, Mg2+, and Ca2+ and anions such as chloride, nitrate, sulfate, and acetate did not significantly affect uptake of Cu2+ whereas EDTA substantially affected adsorption of the metal. When experiments were performed with different desorbents the results indicated that EDTA was an efficient desorbent for the recovery of Cu2+ from biomass. IR spectral analysis suggested amido or hydroxy, C=O, and C-O could combine strongly with Cu2+.
Robertson, Mary M
2015-01-01
This Series is a personal narrative of my experience with patients with Gilles de la Tourette syndrome and covers its definition and history since the first description in 1825. Controversy entered the prevalence debate early. Although originally considered very rare, in the 1980s, Tourette's syndrome was reported to be common. However, Tourette's syndrome has been shown to occur at a prevalence of about 0·85% to 1%. Tourette's syndrome is more common in the male population, more prominent during childhood, and usually improves, but does not disappear with age. Tourette's syndrome is considered less common in people of sub-Saharan black African, African-American, and American Hispanic ethnic origin. The phenomenology is similar worldwide, indicating a biological basis. The hallmark characteristics are multiple motor and one or more vocal/phonic tics. Other associated features include premonitory urges, a waxing and waning course, and to a much lesser degree, coprolalia. Comorbid disorders are common and are suggested to include obsessive-compulsive disorder and behaviours, attention deficit hyperactivity disorder, and autistic spectrum disorder. Coexistent psychopathologies are suggested to include depression and conduct and personality disorders. Importantly, I argue that Tourette's syndrome is not a unitary condition. Finally, I offer suggestions for future research. Copyright © 2015 Elsevier Ltd. All rights reserved.
Coexistence of glandular papilloma and sclerosing pneumocytoma in the bronchiole.
Kitawaki, Yuko; Fujishima, Fumiyoshi; Taniuchi, Shinji; Saito, Ryoko; Nakamura, Yasuhiro; Sato, Ryoko; Aoyama, Yayoi; Onodera, Yoshiaki; Inoshita, Naoko; Matsuda, Yasushi; Watanabe, Mika; Sasano, Hironobu
2018-04-25
Both glandular papilloma (GP) and sclerosing pneumocytoma (SP) are rare tumors in the lung. We herein report an extremely rare case of coexistence of these two uncommon tumors. The patient was a 40-year-old Japanese woman with no chief complaint. A solitary nodule of the lung was detected using chest computed tomography. The transbronchial biopsy revealed that the tumor histologically corresponded to GP. The patient subsequently underwent partial resection of the right upper lobe. Histological examination of the resected specimens further revealed that the mass contained two different and independent elements and displayed typically histological features of GP and SP. Molecular analysis further revealed the presence of BRAF V600E and AKT1 E17K mutations in GP, whereas only AKT1 mutation was detected in SP. To our knowledge, this is the first case of coexistence of GP and SP in the bronchiole harboring common AKT1 mutation and different BRAF V600E mutational status. © 2018 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.
Park, Hyun Woo; Lee, Hyun Seok; Hwang, Sejin; Lee, Han Sol; Bae, Han-Ik; Yoon, Ghilsuk
2017-04-01
A 31-year-old woman with a 15-year history of Takayasu's arteritis (TA) and a 13-year history of Hashimoto's thyroiditis presented with hematochezia. She received a diagnosis of Sjögren's syndrome at 1 month before her visit to Kyungpook National University Medical Center. Her colonoscopic findings were compatible with a diagnosis of ulcerative colitis (UC). She was treated with oral mesalazine, and her hematochezia symptoms subsequently disappeared. The coexistence of UC and TA has been reported; however, reports on the coexistence of UC and Sjögren's syndrome, or of UC and Hashimoto's thyroiditis are rare. Although the precise etiologies of these diseases are unknown, their presence together suggests that they may have a common pathophysiologic background. Furthermore, in patients with autoimmune or vascular diseases, including TA, systemic manifestations should be assessed with consideration of inflammatory bowel diseases including UC in the presence of gastrointestinal symptoms such as diarrhea and hematochezia.
NASA Astrophysics Data System (ADS)
Attygalle, Athula B.; Xia, Hanxue; Pavlov, Julius
2017-08-01
The gas-phase-ion generation technique and specific ion-source settings of a mass spectrometer influence heavily the protonation processes of molecules and the abundance ratio of the generated protomers. Hitherto that has been attributed primarily to the nature of the solvent and the pH. By utilizing electrospray ionization and ion-mobility mass spectrometry (IM-MS), we demonstrate, even in the seemingly trivial case of protonated aniline, that the protomer ratio strongly depends on the source conditions. Under low in-source ion activation, nearly 100% of the N-protomer of aniline is produced, and it can be subsequently converted to the C-protomer by collisional activation effected by increasing the electrical potential difference between the entrance and exit orifices of the first vacuum region. This activation and transformation process takes place even before the ion is mass-selected and subjected to IM separation. Despite the apparent simplicity of the problem, the preferred protonation site of aniline in the gas phase—the amino group or the aromatic ring—has been a topic of controversy. Our results not only provide unambiguous evidence that ring- and nitrogen-protonated aniline can coexist and be interconverted in the gas phase, but also that the ratio of the protomers depends on the internal energy of the original ion. There are many dynamic ion-transformation and fragmentation processes that take place in the different physical compartments of a Synapt G2 HDMS instrument. Such processes can dramatically change the very identity even of small ions, and therefore should be taken into account when interpreting product-ion mass spectra.
NASA Astrophysics Data System (ADS)
Patsahan, O. V.; Patsahan, T. M.; Holovko, M. F.
2018-02-01
We develop a theory based on the method of collective variables to study the vapor-liquid equilibrium of asymmetric ionic fluids confined in a disordered porous matrix. The approach allows us to formulate the perturbation theory using an extension of the scaled particle theory for a description of a reference system presented as a two-component hard-sphere fluid confined in a hard-sphere matrix. Treating an ionic fluid as a size- and charge-asymmetric primitive model (PM) we derive an explicit expression for the relevant chemical potential of a confined ionic system which takes into account the third-order correlations between ions. Using this expression, the phase diagrams for a size-asymmetric PM are calculated for different matrix porosities as well as for different sizes of matrix and fluid particles. It is observed that general trends of the coexistence curves with the matrix porosity are similar to those of simple fluids under disordered confinement, i.e., the coexistence region gets narrower with a decrease of porosity and, simultaneously, the reduced critical temperature Tc* and the critical density ρi,c * become lower. At the same time, our results suggest that an increase in size asymmetry of oppositely charged ions considerably affects the vapor-liquid diagrams leading to a faster decrease of Tc* and ρi,c * and even to a disappearance of the phase transition, especially for the case of small matrix particles.
Pulmonary Embolism and Atrial Fibrillation: Two Sides of the Same Coin? A Systematic Review.
Bikdeli, Behnood; Abou Ziki, Maen D; Lip, Gregory Y H
2017-11-01
Pulmonary embolism (PE) is a common, potentially fatal thrombotic disease. Atrial fibrillation (AF), the most common arrhythmia, may also lead to thromboembolic complications. Although initially appearing as distinct entities, PE and AF may coexist. The direction and extent of this association has not been well characterized. We performed a search of PubMed, Scopus, and the Cochrane Database of Systematic Reviews for publications that reported coexisting AF in patients with PE, or vice versa, to provide a systematic overview of pathophysiological and epidemiological aspects of this association (last search: October 13, 2016). We screened 650 articles following the PubMed search, and 697 through Scopus. PE and AF share many common risk factors, including old age, obesity, heart failure, and inflammatory states. In addition, PE may lead to AF through right-sided pressure overload or inflammatory cytokines. AF, in turn, might lead to right atrial appendage clot formation and thereby PE. Epidemiological studies indicate that AF can be seen as a presenting sign, during the early phase, or later in the course of recovery from PE. Patients with AF are also at increased risk of developing PE, a risk that correlates with the CHA 2 DS 2 -VASc score. For the choice of antithrombotic therapy, PE-related factors (provoked or unproved, active cancer, and prior recurrence) and AF-related factors (CHA 2 DS 2 -VASc score), risk of bleeding, and patient preferences should be considered. In conclusion, PE and AF may coexist, with an understudied bidirectional association. Prognostication and choice of antithrombotic therapy in patients with both PE and AF might be different compared with those who present with only one of the two and warrants further investigation. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
The coexistence of autoimmune rheumatic diseases and thymomas.
Jiang, Ying; Dai, Xiaodan; Duan, Liping; Zhou, Yaou
2017-01-01
Autoimmune rheumatic diseases (ARDs), involving immune disturbances resulting from auto-inflammatory mechanisms, are a group of diseases characterized by autoimmunity and autoimmunemediated organ damage. Thymoma, whose mechanism is also associated with immune abnormalities, is the most common neoplasm of the anterior mediastinum. But thymoma with ARDs is relatively less frequent. The clinical characteristics of the coexistence of ARDs and thymomas are still not very clear. And the therapeutic strategy for ARDs combined with thymomas varies, with an uncertain outcome. The aim of this study was to investigate the clinical characteristics of the coexistence of ARDs and thymomas in order to speculate whether a thymectomy is effective for ARDs combined with thymomas, and to seek the proper therapeutic strategy for treating ARDs combined with thymomas. We presented 2 cases of the coexistence of ARDs and thymomas. Then, we summarized 20 cases (including our 2 cases) in which the ARD was diagnosed concurrently with, or prior to, the thymoma. Pure red cell aplastic anemia (PRCA) might be associated with an ARD and a thymoma, and a thymectomy may lead to the appearance, exacerbation, or remission of ARDs. Searching for a thymoma is necessitated if a patient with ARDs experiences PRCA and the effects of thymectomy in ARDs combined with thymomas may be associated with the onset sequence of ARDs and thymomas.
Yeo, Min-Kyung; Bae, Ja Seong; Lee, Sohee; Kim, Min-Hee; Lim, Dong-Jun; Lee, Youn Soo; Jung, Chan Kwon
2015-01-01
Background. The Warthin-like variant of papillary thyroid (WLPTC) is a rare subtype of papillary thyroid carcinoma (PTC) resembling Warthin tumors of the salivary glands. Due to its rarity, the clinicopathologic and molecular features of WLPTC remain unclear. Methods. Of the 2,139 patients who underwent surgical treatment for PTC from 2012 to 2013, 40 patients with WLPTC were identified and compared to 200 consecutive patients with classic PTC. BRAF mutation was tested with pyrosequencing. Results. There were no significant differences in age, predilection for women, multifocality, extrathyroidal extension, or lymph node metastasis between WLPTC and classic PTC. However, WLPTCs were more commonly associated with Hashimoto's thyroiditis than classic PTCs (93% versus 36%, resp., P < 0.001) and showed significantly lower rate of BRAF mutation when compared to classic PTCs (65% versus 84%, resp., P = 0.007). In classic PTC, the frequency of BRAF mutations was negatively correlated with coexisting Hashimoto's thyroiditis. When we compared WLPTC and classic PTC in the patients with coexisting Hashimoto's thyroiditis, there were no significant differences in clinicopathologic characteristics or the BRAF mutational rate between the two groups. Conclusions. Patients with WLPTC have similar demographic, clinical, pathologic, and molecular characteristics to those with classic PTC coexisting with Hashimoto's thyroiditis.
Yeo, Min-kyung; Bae, Ja Seong; Lim, Dong-Jun; Lee, Youn Soo
2015-01-01
Background. The Warthin-like variant of papillary thyroid (WLPTC) is a rare subtype of papillary thyroid carcinoma (PTC) resembling Warthin tumors of the salivary glands. Due to its rarity, the clinicopathologic and molecular features of WLPTC remain unclear. Methods. Of the 2,139 patients who underwent surgical treatment for PTC from 2012 to 2013, 40 patients with WLPTC were identified and compared to 200 consecutive patients with classic PTC. BRAF mutation was tested with pyrosequencing. Results. There were no significant differences in age, predilection for women, multifocality, extrathyroidal extension, or lymph node metastasis between WLPTC and classic PTC. However, WLPTCs were more commonly associated with Hashimoto's thyroiditis than classic PTCs (93% versus 36%, resp., P < 0.001) and showed significantly lower rate of BRAF mutation when compared to classic PTCs (65% versus 84%, resp., P = 0.007). In classic PTC, the frequency of BRAF mutations was negatively correlated with coexisting Hashimoto's thyroiditis. When we compared WLPTC and classic PTC in the patients with coexisting Hashimoto's thyroiditis, there were no significant differences in clinicopathologic characteristics or the BRAF mutational rate between the two groups. Conclusions. Patients with WLPTC have similar demographic, clinical, pathologic, and molecular characteristics to those with classic PTC coexisting with Hashimoto's thyroiditis. PMID:25983754
Role of the constant region domain in the structural diversity of human antibody light chains.
Hifumi, Emi; Taguchi, Hiroaki; Kato, Ryuichi; Uda, Taizo
2017-04-01
Issues regarding the structural diversity (heterogeneity) of an antibody molecule have been the subject of discussion along with the development of antibody drugs. Research on heterogeneity has been extensive in recent years, but no clear solution has been reached. Heterogeneity is also observed in catalytic antibody κ light chains (CLs). In this study, we investigated how the constant region domain of CLs concerns structural diversity because it is a simple and good example for elucidating heterogeneity. By means of cation-exchange chromatography, SDS-PAGE, and 2-dimensional electrophoresis for the CL, multimolecular forms consisting of different electrical charges and molecular sizes coexisted in the solution, resulting in the similar heterogeneity of the full length of CLs. The addition of copper ion could cause the multimolecular forms to change to monomolecular forms. Copper ion contributed greatly to the enrichment of the dimer form of CL and the homogenization of the differently charged CLs. Two molecules of the CL protein bound one copper ion. The binding affinity of the ion was 48.0 μM -1 Several divalent metal ions were examined, but only zinc showed a similar effect.-Hifumi, E., Taguchi, H., Kato, R., Uda, T. Role of the constant region domain in the structural diversity of human antibody light chains. © FASEB.
NASA Astrophysics Data System (ADS)
Mahajan, Prasad G.; Dige, Nilam C.; Desai, Netaji K.; Patil, Shivajirao R.; Kondalkar, Vijay V.; Hong, Seong-Karp; Lee, Ki Hwan
2018-06-01
Nowadays scientist over the world are engaging to put forth improved methods to detect metal ion in an aqueous medium based on fluorescence studies. A simple, selective and sensitive method was proposed for detection of Co2+ ion using fluorescent organic nanoparticles. We synthesized a fluorescent small molecule viz. 4,4‧-{benzene-1,4-diylbis-[(Z)methylylidenenitrilo]}dibenzoic acid (BMBA) to explore its suitability as sensor for Co2+ ion and biocompatibility in form of nanoparticles. Fluorescence nanoparticles (BMBANPs) prepared by simple reprecipitation method. Aggregation induced enhanced emission of BMBANPs exhibits the narrower particle size of 68 nm and sphere shape morphology. The selective fluorescence quenching was observed by addition of Co2+ and does not affected by presence of other coexisting ion solutions. The photo-physical properties, viz. UV-absorption, fluorescence emission, and lifetime measurements are in support of ligand-metal interaction followed by static fluorescence quenching phenomenon in emission of BMBANPs. Finally, we develop a simple analytical method for selective and sensitive determination of Co2+ ion in environmental samples. The cell culture E. coli, Bacillus sps., and M. tuberculosis H37RV strain in the vicinity of BMBANPs indicates virtuous anti-bacterial and anti-tuberculosis activity which is of additional novel application shown by prepared nanoparticles.
Poultry litter-based activated carbon for removing heavy metal ions in water.
Guo, Mingxin; Qiu, Guannan; Song, Weiping
2010-02-01
Utilization of poultry litter as a precursor material to manufacture activated carbon for treating heavy metal-contaminated water is a value-added strategy for recycling the organic waste. Batch adsorption experiments were conducted to investigate kinetics, isotherms, and capacity of poultry litter-based activated carbon for removing heavy metal ions in water. It was revealed that poultry litter-based activated carbon possessed significantly higher adsorption affinity and capacity for heavy metals than commercial activated carbons derived from bituminous coal and coconut shell. Adsorption of metal ions onto poultry litter-based carbon was rapid and followed Sigmoidal Chapman patterns as a function of contact time. Adsorption isotherms could be described by different models such as Langmuir and Freundlich equations, depending on the metal species and the coexistence of other metal ions. Potentially 404 mmol of Cu2+, 945 mmol of Pb2+, 236 mmol of Zn2+, and 250-300 mmol of Cd2+ would be adsorbed per kg of poultry litter-derived activated carbon. Releases of nutrients and metal ions from litter-derived carbon did not pose secondary water contamination risks. The study suggests that poultry litter can be utilized as a precursor material for economically manufacturing granular activated carbon that is to be used in wastewater treatment for removing heavy metals.
A systematic probe in the properties of spray coated mixed spinel films of cobalt and manganese
NASA Astrophysics Data System (ADS)
Grace Victoria, S.; Moses Ezhil Raj, A.
2018-01-01
The multiple oxidation states of manganese and cobalt in cobalt manganese oxides play a crucial role in shaping up the vivid properties thus evoking curiosity among researchers. In the present work, mixed spinel films of CoMn(CoMn)2O4 were coated on glass substrates by the spray pyrolysis technique with different precursor concentrations of the acetate salts of the metals in ethyl alcohol. XRD investigations revealed an intermediate tetragonal spinel structure between cubic MnCo2O4 and tetragonal Mn3O4 (JCPDS 18-0410) with predominant orientation along (311) plane. The tetragonal distortion from cubic symmetry may be due to high Mn2+ ion content at octahedral sites. Raman spectroscopy highlighted two typical emission peaks characteristic of the deposited mixed spinel oxides. Functional groups were assigned with the aid of FTIR spectral analysis to the observed absorption bands. The binding energies of the photo-electron peaks observed for the transition metal ions and the oxygenated ions were recorded by XPS. The results indicated that the divalent and trivalent ions of cobalt co-existed with the divalent manganese ions. AFM images revealed vertically aligned columnar grains. The electrical measurements indicated conduction mechanism through jumps of polarons. Optical absorption revealed wide band gap energy of 3.76 eV.
Robustness, Death of Spiral Wave in the Network of Neurons under Partial Ion Channel Block
NASA Astrophysics Data System (ADS)
Ma, Jun; Huang, Long; Wang, Chun-Ni; Pu, Zhong-Sheng
2013-02-01
The development of spiral wave in a two-dimensional square array due to partial ion channel block (Potassium, Sodium) is investigated, the dynamics of the node is described by Hodgkin—Huxley neuron and these neurons are coupled with nearest neighbor connection. The parameter ratio xNa (and xK), which defines the ratio of working ion channel number of sodium (potassium) to the total ion channel number of sodium (and potassium), is used to measure the shift conductance induced by channel block. The distribution of statistical variable R in the two-parameter phase space (parameter ratio vs. poisoning area) is extensively calculated to mark the parameter region for transition of spiral wave induced by partial ion channel block, the area with smaller factors of synchronization R is associated the parameter region that spiral wave keeps alive and robust to the channel poisoning. Spiral wave keeps alive when the poisoned area (potassium or sodium) and degree of intoxication are small, distinct transition (death, several spiral waves coexist or multi-arm spiral wave emergence) occurs under moderate ratio xNa (and xK) when the size of blocked area exceeds certain thresholds. Breakup of spiral wave occurs and multi-arm of spiral waves are observed when the channel noise is considered.
First Principles Simulations fo the Supercritical Behavior of Ore Forming Fluids
DOE Office of Scientific and Technical Information (OSTI.GOV)
Weare, John H
2013-04-19
Abstract of Selected Research Progress: I. First-principles simulation of solvation structure and deprotonation reactions of ore forming metal ions in very nonideal solutions: Advances in algorithms and computational performance achieved in this grant period have allowed the atomic level dynamical simulation of complex nanoscale materials using interparticle forces calculated directly from an accurate density functional solution to the electronic Schr dinger equation (ab-initio molecular dynamics, AIMD). Focus of this program was on the prediction and analysis of the properties of environmentally important ions in aqueous solutions. AIMD methods have provided chemical interpretations of these very complex systems with an unprecedentedmore » level of accuracy and detail. The structure of the solvation region neighboring a highly charged metal ion (e.g., 3+) in an aqueous solution is very different from that of bulk water. The many-body behaviors (polarization, charge transfer, etc.) of the ion-water and water-water interactions in this region are difficult to capture with conventional empirical potentials. However, a large numbers of waters (up to 128 waters) are required to fully describe chemical events in the extended hydrations shells and long simulation times are needed to reliably sample the system. Taken together this makes simulation at the 1st principles level a very large computational problem. Our AIMD simulation results using these methods agree with the measured octahedral structure of the 1st solvation shell of Al3+ at the 1st shell boundary and a calculated radius of 1.937 (exp. 1.9). Our calculated average 2nd shell radius agrees remarkably well with the measured radius, 4.093 calculated vs. the measured value of 4.0-4.15 . Less can be experimentally determined about the structure of the 2nd shell. Our simulations show that this shell contains roughly 12 water molecules, which are trigonally coordinated to the 1st shell waters. This structure cannot be measured directly. However, the number of 2nd shell water molecules predicted by the simulation is consistent with experimental estimates. Tetrahedral bulk water coordination reappears just after the 2nd shell. Simulations with 128 waters are close to the maximum size that can effectively be performed with present day methods. While the time scale of our simulation are not long enough to observe transfers of waters from the 1st to the 2nd shell, we do see transfers occurring on a picosecond time scale between the 2nd shell and 3rd shell via an associative mechanism. This is faster than, but consistent with, the results of measurements on the more tightly bound Cr3+ system. For high temperature simulations, proton transfers occur in the solvation shells leading to transient hydrolysis species. The reaction coordinate for proton transfer involves the coordinates of neighboring solvent waters as in the Grotis mechanism for proton transfer in bulk water. Directly removing a proton from the hexaqua Al3+ ion leads to a much more labile solvation shell and to a five coordinated Al3+ ion. This is consistent with very recent rate measurements of ligand exchange and the conjugate base labilization effect. For the Al3+-H2O system results for high but subcritical temperatures are qualitatively similar to room temperature simulations. However, preliminary simulations for supercritical temperatures (750K) suggest that there may be a dramatic change in behavior in the hydration structure of ions for these temperatures. For transition metal ions the presence of d valence electrons plays a significant role in the behavior of the system. Our preliminary results for the Fe3+ ion suggest that this ion which is larger radius than the Al3+ ion has somewhat less rigid 1st and 2nd solvation shell. II. Gibbs Ensemble Monte Carlo Simulation of Vapor/Liquid and Metastable Liquid/Liquid Phase Equilibria in the CO2-CH4-N2 System Many fluid inclusions have compositions in the system CO2-CH4-N2. Estimates of the saturation pressures, compositions and volumetric properties of coexisting phases in the unaries, binaries and the ternary of this system have been obtained from simulations using the Gibbs Ensemble Monte Carlo method. The temperature and pressure range considered include liquid/vapor, gas/gas and metastable liquid/liquid regions. All the molecular interactions in the system were described with two-body Lennard-Jones potentials requiring only two temperature independent parameters for interactions between like molecules. The Berthhelot-Lorentz rules are used to define the Lennard-Jones interactions for unlike molecules with one additional temperature independent mixing parameter. The equilibrium compositions and molar volumes of the coexisting phases in all the mixtures are predicted with accuracy close to that of the data. These results, particularly for the phase densities and critical parameters, are considerably closer to the observed values than those that have been reported using equation of state methods(116). For very low temperatures liquid/metastable liquid/vapor coexistence was observed for the CO2-N2 and the CH4-CO2 systems, e.g. the L1L2V line. The possibility of gas-gas coexistence for the binary N2-CO2 at high temperatures and pressures was also investigated but not observed.« less
Depression and Heart Diseases: Leading Health Problems.
Raič, Matea
2017-12-01
Depression is the most common psychiatric disorder in the world population and the most frequent mental disorder in a primary health care. Unrecognized and untreated depression is associated with a poor outcome of treated chronic diseases which co-exist with depression. Depression and cardiovascular diseases are bidirectional related conditions, risks are for each other, and they often co-exist. Depression is a common disorder in cardiovascular patients with a prevalence of 20% to 45%, which is much more frequent than in the general population. In cardiac patients with acute myocardial infarction, depression occurs three times more often than in the general population. Depression has a direct effect on the pathophysiological changes of various organ systems, changing the values of blood pressure, heart rate, vasomotor tone, vascular resistance, blood viscosity and plasma volume. The potential mechanism for developing heart disease in depressed patients includes hypothalamic-pituitary-adrenal gland dysfunction, increased proinflammatory and prothrombotic factor activity, reduced omega-3 fatty acids, reduced heart rate variability, smoking, physical inactivity, reduced mood, self-esteem and self-efficacy.
Li, Yongtao; Whitaker, Joshua S; McCarty, Christina L
2012-07-06
A large volume direct aqueous injection method was developed for the analysis of iodinated haloacetic acids in drinking water by using reversed-phase liquid chromatography/electrospray ionization/tandem mass spectrometry in the negative ion mode. Both the external and internal standard calibration methods were studied for the analysis of monoiodoacetic acid, chloroiodoacetic acid, bromoiodoacetic acid, and diiodoacetic acid in drinking water. The use of a divert valve technique for the mobile phase solvent delay, along with isotopically labeled analogs used as internal standards, effectively reduced and compensated for the ionization suppression typically caused by coexisting common inorganic anions. Under the optimized method conditions, the mean absolute and relative recoveries resulting from the replicate fortified deionized water and chlorinated drinking water analyses were 83-107% with a relative standard deviation of 0.7-11.7% and 84-111% with a relative standard deviation of 0.8-12.1%, respectively. The method detection limits resulting from the external and internal standard calibrations, based on seven fortified deionized water replicates, were 0.7-2.3 ng/L and 0.5-1.9 ng/L, respectively. Copyright © 2012 Elsevier B.V. All rights reserved.
Daşbaşı, Teslima; Saçmacı, Şerife; Ülgen, Ahmet; Kartal, Şenol
2015-05-01
A relatively rapid, accurate and precise solid phase extraction method is presented for the determination of cadmium(II) and lead(II) in various food and water samples. Quantitation is carried out by flame atomic absorption spectrometry (FAAS). The method is based on the retention of the trace metal ions on Dowex Marathon C, a strong acid cation exchange resin. Some important parameters affecting the analytical performance of the method such as pH, flow rate and volume of the sample solution; type, concentration, volume, flow rate of the eluent; and matrix effects on the retention of the metal ions were investigated. Common coexisting ions did not interfere on the separation and determination of the analytes. The detection limits (3 σb) for Cd(II) and Pb(II) were found as 0.13 and 0.18 μg L(-1), respectively, while the limit of quantification values (10 σb) were computed as 0.43 and 0.60 μg L(-1) for the same sequence of the analytes. The precision (as relative standard deviation was lower than 4% at 5 μg L(-1) Cd(II) and 10 μg L(-1) Pb(II) levels, and the preconcentration factor was found to be 250. The accuracy of the proposed procedure was verified by analysing the certified reference materials, SPS-WW2 Batch 108 wastewater level 2 and INCT-TL-1 tea leaves, with the satisfactory results. In addition, for the accuracy of the method the recovery studies (⩾ 95%) were carried out. The method was applied to the determination of the analytes in the various natural waters (lake water, tap water, waste water with boric acid, waste water with H2SO4) and food samples (pomegranate flower, organic pear, radish leaf, lamb meat, etc.), and good results were obtained. While the food samples almost do not contain cadmium, they have included lead at low levels of 0.13-1.12 μg g(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Laszlo, Kenneth J.; Bush, Matthew F.
2015-12-01
Mass spectra of native-like protein complexes often exhibit narrow charge-state distributions, broad peaks, and contributions from multiple, coexisting species. These factors can make it challenging to interpret those spectra, particularly for mixtures with significant heterogeneity. Here we demonstrate the use of ion/ion proton transfer reactions to reduce the charge states of m/ z-selected, native-like ions of proteins and protein complexes, a technique that we refer to as cation to anion proton transfer reactions (CAPTR). We then demonstrate that CAPTR can increase the accuracy of charge state assignments and the resolution of interfering species in native mass spectrometry. The CAPTR product ion spectra for pyruvate kinase exhibit ~30 peaks and enable unambiguous determination of the charge state of each peak, whereas the corresponding precursor spectra exhibit ~6 peaks and the assigned charge states have an uncertainty of ±3%. 15+ bovine serum albumin and 21+ yeast enolase dimer both appear near m/ z 4450 and are completely unresolved in a mixture. After a single CAPTR event, the resulting product ions are baseline resolved. The separation of the product ions increases dramatically after each subsequent CAPTR event; 12 events resulted in a 3000-fold improvement in separation relative to the precursor ions. Finally, we introduce a framework for interpreting and predicting the figures of merit for CAPTR experiments. More generally, these results suggest that CAPTR strongly complements other mass spectrometry tools for analyzing proteins and protein complexes, particularly those in mixtures.
Functionalized polyethylene fibers for the selective capture of palladium ions from aqueous solution
NASA Astrophysics Data System (ADS)
Pang, Li-juan; Li, Rong; Hu, Jiang-tao; Zhang, Lin-juan; Zhang, Ming-xing; Yang, Chen-guang; Wu, Guo-zhong
2018-03-01
An innovative ultrahigh molecular weight polyethylene (UHMWPE) fibrous adsorbent was successfully synthesized via radiation grafting and applied to the selective capture of palladium ions from dilute aqueous solutions. The influence of the pH, initial Pd(II) concentration, and temperature on the adsorption performance was examined in a batch adsorption experiment. Pd K-edge extended X-ray absorption fine structure (EXAFS) spectra indicated that Pd(II) was immobilized on the adsorbent surface via a ligand exchange reaction that formed a stable UHMWPE-PMDA-Pd complex. Although the concentrations of coexisting ions (Cu(II), Zn(II), Cr(VI), Fe(III), and Ni(II)) in the solution were much higher than that of Pd(II), the adsorption capacity for Pd(II) of the as-prepared absorbent was significantly greater than that for other metal ions. Kinetic studies showed good correlation with the pseudo-second-order model. The maximum capacity for Pd(II) adsorption was approximately 221.8 mg·g-1 at 298 K. The adsorption behavior conformed to the Langmuir isotherm model. Thermodynamic studies revealed that the adsorption of Pd(II) was a feasible, spontaneous, and endothermic process.
Effect of Ca2+ Ions on Electrical Properties of Ba1-x Ca x Ti0.90Sn0.10O3-0.05Y2O3 Ceramics
NASA Astrophysics Data System (ADS)
Chen, Zhi-hui; Li, Zhi-wei; Ding, Jian-ning; Zhao, Tian-xiang; Qiu, Jian-hua; Zhu, Ke-qian; Xu, Jiu-jun; Zhang, Bing
2018-03-01
Ba1-x Ca x Ti0.90Sn0.10O3-0.05Y2O3 (BCTSY) lead-free piezoceramics with x = 0.02 to 0.10 have been fabricated by solid-state sintering method at 1420°C. The effects of Ca2+ ions on the microstructure and electrical properties of the samples were studied. X-ray diffraction analysis showed that all samples possessed pure perovskite structure with Ca2+ ions diffused into the matrix lattice. The rhombohedral phase and tetragonal phase coexisted in the composition range of 0.02 < x < 0.06. The microstructure of BCTSY ceramic became more homogeneous with addition of Ca2+ ions, and the average grain size of the samples decreased from 97 μm (x = 0.02) to 18 μm (x = 0.10). Addition of Ca2+ remarkably improved the piezoelectric properties, enhanced the dielectric frequency dispersion, and increased the Curie temperature of the ceramics. The piezoelectric properties of the ceramics were optimized at x = 0.04 with d 33 and K p values of 579 pC/N and 52.7%, respectively.
NASA Astrophysics Data System (ADS)
Zhu, Jing-Hui; Zhao, Xin; Yang, Jidong; Tan, Yu-Ting; Zhang, Lei; Liu, Shao-Pu; Liu, Zhong-Fang; Hu, Xiao-Li
2016-04-01
Under pH 4.0 HAc-NaAc buffer medium, curcumin alone possesses extraordinary weak fluorescence emission. Nevertheless, the introduction of Triton X-100 micelles can largely enhance the fluorescence intensity of curcumin. Uranyl ions can complex with micelles-capped curcumin, along with the slight red shift of curcumin fluorescence (about 1-7 nm), a clear decrement of absorbance (424 nm) and fluorescence (507 nm) intensities, and a distinct color change from bright yellow to orange. The fluorescence decrements (ΔF, 507 nm) are positively correlated to the amount of uranyl ions in the concentration range of 3.7 × 10- 6-1.4 × 10- 5 mol L- 1. The detection limit of this fluorescence quenching methods is 3.7 × 10- 6 mol L- 1, which is nearly 9000 times lower than the maximum allowable level in drinking water proposed by World Health Organization. Good selectivity is achieved because of a majority of co-existing substances (such as Ce4 +, La3 +, and Th4 +) do not affect the detection. The content of uranyl ions in tap water samples was determined by the proposed method with satisfactory results.
Effect of Ca2+ Ions on Electrical Properties of Ba1- x Ca x Ti0.90Sn0.10O3-0.05Y2O3 Ceramics
NASA Astrophysics Data System (ADS)
Chen, Zhi-hui; Li, Zhi-wei; Ding, Jian-ning; Zhao, Tian-xiang; Qiu, Jian-hua; Zhu, Ke-qian; Xu, Jiu-jun; Zhang, Bing
2018-07-01
Ba1- x Ca x Ti0.90Sn0.10O3-0.05Y2O3 (BCTSY) lead-free piezoceramics with x = 0.02 to 0.10 have been fabricated by solid-state sintering method at 1420°C. The effects of Ca2+ ions on the microstructure and electrical properties of the samples were studied. X-ray diffraction analysis showed that all samples possessed pure perovskite structure with Ca2+ ions diffused into the matrix lattice. The rhombohedral phase and tetragonal phase coexisted in the composition range of 0.02 < x < 0.06. The microstructure of BCTSY ceramic became more homogeneous with addition of Ca2+ ions, and the average grain size of the samples decreased from 97 μm ( x = 0.02) to 18 μm ( x = 0.10). Addition of Ca2+ remarkably improved the piezoelectric properties, enhanced the dielectric frequency dispersion, and increased the Curie temperature of the ceramics. The piezoelectric properties of the ceramics were optimized at x = 0.04 with d 33 and K p values of 579 pC/N and 52.7%, respectively.
Phenotype and Clinical Course of Inflammatory Bowel Disease with Co-Existent Celiac Disease.
Tse, Chung Sang; Deepak, Parakkal; De La Fuente, Jaime; Bledsoe, Adam C; Larson, Joseph J; Murray, Joseph A; Papadakis, Konstantinos A
2018-05-07
Inflammatory bowel diseases, principally Crohn's disease and ulcerative colitis, and celiac disease are among the most common immune-mediated gastrointestinal diseases. We aim to elucidate the clinical course and outcomes of patients with concomitant inflammatory bowel disease and celiac disease, a unique population that remains scarcely studied to date. A retrospective matched case-control study of adults with coexistent inflammatory bowel disease and celiac disease was performed at a tertiary referral institution in North America. Logistic regression and Kaplan-Meier curves compared disease characteristics and clinical outcomes of the two groups. A total of 342 inflammatory bowel disease patients were included in this study, of which 114 had coexistent celiac disease and 228 did not. Patients with coexistent inflammatory bowel disease and celiac disease had higher rates of primary sclerosing cholangitis (19.3% vs 5.7%; odds ratio, 4.4; 95% confidence interval, 2.1-9.4; p<0.001), extensive ulcerative colitis (78.1% vs 59.0%; odds ratio, 2.8; 95% confidence interval 1.5-5.5, p=0.002), and family history of celiac disease (10.5% vs 3.5%; odds ratio 3.2; 95% confidence interval 1.3-8.2; p=0.01), compared to patients without concomitant celiac disease. Patients with inflammatory bowel disease with concomitant celiac disease have unique phenotypic features compared to non-celiac inflammatory bowel disease, with higher risks for colitis-related hospitalizations, extensive colitis, and primary sclerosing cholangitis. Increased recognition of coexistent IBD and celiac disease can prompt clinicians to investigate for concomitant disease sooner, particularly in patients with seemingly refractory disease.
Multitrait successional forest dynamics enable diverse competitive coexistence
Brännström, Åke; Westoby, Mark; Dieckmann, Ulf
2017-01-01
To explain diversity in forests, niche theory must show how multiple plant species coexist while competing for the same resources. Although successional processes are widespread in forests, theoretical work has suggested that differentiation in successional strategy allows only a few species stably to coexist, including only a single shade tolerant. However, this conclusion is based on current niche models, which encode a very simplified view of plant communities, suggesting that the potential for niche differentiation has remained unexplored. Here, we show how extending successional niche models to include features common to all vegetation—height-structured competition for light under a prevailing disturbance regime and two trait-mediated tradeoffs in plant function—enhances the diversity of species that can be maintained, including a diversity of shade tolerants. We identify two distinct axes of potential niche differentiation, corresponding to the traits leaf mass per unit leaf area and height at maturation. The first axis allows for coexistence of different shade tolerances and the second axis for coexistence among species with the same shade tolerance. Addition of this second axis leads to communities with a high diversity of shade tolerants. Niche differentiation along the second axis also generates regions of trait space wherein fitness is almost equalized, an outcome we term “evolutionarily emergent near-neutrality.” For different environmental conditions, our model predicts diverse vegetation types and trait mixtures, akin to observations. These results indicate that the outcomes of successional niche differentiation are richer than previously thought and potentially account for mixtures of traits and species observed in forests worldwide. PMID:28283658
Ion-Specific Interfacial Crystallization of Polymer-Grafted Nanoparticles
Zhang, Honghu; Wang, Wenjie; Mallapragada, Surya; ...
2017-06-27
In this study, ion-specific effects on the assembly and crystallization of polyethylene-glycol-grafted Au nanoparticles (PEG-AuNPs) at the vapor–liquid interface are examined by surface sensitive synchrotron X-ray scattering methods. We show that monovalent salts, such as KCl and NaCl, that do not advance phase separation of pure PEG at room temperature induce two-dimensional (2D) self-assembly and crystallization of PEG-AuNPs with some distinctions. Whereas for KCl the 2D hexagonal coherence length of the PEG-AuNP superlattices is remarkably large compared to other salts (over micron-sized crystalline grains), NaCl induces coexistence of two hexagonal structures. Using various salts, we find that the value ofmore » the lattice constant is correlated to the ionic hydration entropy consistent with the Hofmeister series.« less
Block Copolymers and Ionic Liquids: A New Class of Functional Nanocomposites
NASA Astrophysics Data System (ADS)
Lodge, Timothy
2009-03-01
Block copolymers provide a remarkably versatile platform for achieving desired nanostructures by self-assembly, with lengthscales varying from a few nanometers up to several hundred nanometers. Ionic liquids are an emerging class of solvents, with an appealing set of physical attributes. These include negligible vapor pressure, high chemical and thermal stability, tunable solvation properties, high ionic conductivity, and wide electrochemical windows. For various applications it will be necessary to solidify the ionic liquid into particular spatial arrangements, such as membranes or gels, or to partition the ionic liquid in coexisting phases, such as microemulsions and micelles. One example includes formation of spherical, cylindrical, and vesicular micelles by poly(butadiene-b-ethylene oxide) and poly(styrene-b-methylmethacrylate) in the common hydrophobic ionic liquids [BMI][PF6] and [EMI][TFSI]. This work has been extended to the formation of reversible micelle shuttles between ionic liquids and water, whereby entire micelles transfer from one phase to the other, reversibly, depending on temperature and solvent quality. Formation of ion gels has been achieved by self-assembly of poly(styrene-b-ethylene oxide-b-styrene) triblocks in ionic liquids, and by the thermoreversible system poly(N-isopropylacrylamide-b-ethylene oxide-b-N-isopropylacrylamide), using as little as 4% copolymer. Further, these gels have been shown to be remarkably effective as gate dielectrics in organic thin film transistors. The remarkably high capacitance of the ion gels (> 10 μF/cm^2) supports a very high carrier density in an organic semiconductor such as poly(3-hexylthiophene), leading to milliamp currents for low applied voltages. Furthermore, the rapid mobility of the ions enables switching speeds approaching 10 kHz, orders of magnitude higher than achievable with other polymer-based dielectrics such as PEO/LiClO4. Finally, we have shown that ordered nanostructures of block copolymers plus ionic liquids show the characteristic self-assembly properties of strongly-segregated systems. Prospects for anisotropic ionic conductivity are also being explored.
Shang, Mengmeng; Liang, Sisi; Lian, Hongzhou; Lin, Jun
2017-06-05
A series of Eu 3+ /Tb 3+ /Mn 2+ -ion-doped Ca 19 Ce(PO 4 ) 14 (CCPO) phosphors have been prepared via the conventional high-temperature solid-state reaction process. Under UV radiation, the CCPO host presents a broad blue emission band from Ce 3+ ions, which are generated during the preparation process because of the formation of deficiency. The Eu 3+ -doped CCPO phosphors can exhibit magenta to red-orange emission as a result of the abnormal coexistence of Ce 3+ /Ce 4+ /Eu 3+ and the metal-metal charge-transfer (MMCT) effect between Ce 3+ and Eu 3+ . When Tb 3+ /Mn 2+ are doped into the hosts, the samples excited with 300 nm UV light present multicolor emissions due to energy transfer (ET) from the host (Ce 3+ ) to the activators with increasing activator concentrations. The emitting colors of CCPO:Tb 3+ phosphors can be tuned from blue to green, and the CCPO:Mn 2+ phosphors can emit red light. The ET mechanism from the host (Ce 3+ ) to Tb 3+ /Mn 2+ is demonstrated to be a dipole-quadrapole interaction for Ce 3+ → Tb 3+ and an exchange interaction for Ce 3+ → Mn 2+ in CCPO:Tb 3+ /Mn 2+ . Abundant emission colors containing white emission were obtained in the Tb 3+ - and Mn 2+ -codoped CCPO phosphors through control of the levels of doped Tb 3+ and Mn 2+ ions. The white-emitted CCPO:Tb 3+ /Mn 2+ phosphor exhibited excellent thermal stability. The photoluminescence properties have shown that these materials might have potential for UV-pumped white-light-emitting diodes.
Ozeki, K; Aoki, H
2016-08-12
Removal of radioactive substances, such as cesium (Cs) and strontium (Sr), has become an emerging issue after the Fukushima Daiichi Nuclear Power Plant Disaster. To assess the possibility that hydroxyapatite (HA) and zeolites can be used for removal of radioactive substances, the adsorption capacities of Cs and Sr on the HA and a zeolite were investigated. The influence of Fe ions on Cs and Sr adsorption on the HA and the zeolite was also evaluated, because Fe ions are the most effective inhibitor of Cs adsorption on the zeolite.In the Cs adsorption process on the HA and the zeolite, the zeolite showed a higher adsorption ratio than the HA, and the maximum sorption capacity of the zeolite was calculated as 196 mg/g, whereas the HA showed a higher Sr adsorption ratio than the zeolite. The maximum sorption capacity of Sr on the HA was 123 mg/g. Under coexistence with Fe, Cs adsorption on the zeolite decreased with increasing Fe concentration, reaching 2.0 ± 0.8% at 0.1 M Fe concentration. In contrast, Cs adsorption on the zeolite was improved by adding the HA. In the case of coexistence of the HA, the Cs adsorption on the mixture of the HA and the zeolite was 52.4% ± 3.6 % at 0.1 M Fe concentration, although Cs adsorption on the HA alone was quite low. In the Fe adsorption processes of the HA and the zeolite, the HA exhibited a maximum sorption capacity of 256 mg/g, which was much higher than that of the zeolite (111 mg/g). The high affinity of Fe on the HA contributes to the improvement of the deteriorated Cs adsorption on the zeolite due to Fe ions.
Gallo, Marco; Muscogiuri, Giovanna; Felicetti, Francesco; Faggiano, Antongiulio; Trimarchi, Francesco; Arvat, Emanuela; Vigneri, Riccardo; Colao, Annamaria
2018-01-01
Diabetes and cancer are common, chronic, and potentially fatal diseases that frequently co-exist. Observational studies have reported an increased risk of cancer in patients with diabetes. Furthermore, many patients with cancer already have diabetes, or develop hyperglycaemia as a consequence of the tumor or of cancer therapies, and coexisting diabetes confers a greater risk of mortality for many malignancies. Managing oncologic patients with diabetes is often complicated, since the co-existence of diabetes and cancer poses several complex clinical questions: what level of glycaemic control to achieve, which therapy to use, how to deal with glucocorticoid therapies and artificial nutrition, how diabetes complications can affect cancer management, which drug-drug interactions should be taken into account, or even how to manage diabetes at the end of life. In the clinical setting, both at hospital and at home, there are little agreed, evidence-based guidelines on the best management and criteria upon which clinical decisions should be based. A practical solution lies in the implementation of care networks based on communication and ongoing collaboration between Oncologists, Endocrinologists, and the nursing staff, with the patient at the centre of the care process. This manuscript aims to review the current evidence on the effect of cancer therapies on glucose metabolism and to address some of the more common challenges of diabetes treatment in patients with cancer. Copyright © 2017 Elsevier Inc. All rights reserved.
Similarity law for Widom lines and coexistence lines
NASA Astrophysics Data System (ADS)
Banuti, D. T.; Raju, M.; Ihme, M.
2017-05-01
The coexistence line of a fluid separates liquid and gaseous states at subcritical pressures, ending at the critical point. Only recently, it became clear that the supercritical state space can likewise be divided into regions with liquidlike and gaslike properties, separated by an extension to the coexistence line. This crossover line is commonly referred to as the Widom line, and is characterized by large changes in density or enthalpy, manifesting as maxima in the thermodynamic response functions. Thus, a reliable representation of the coexistence line and the Widom line is important for sub- and supercritical applications that depend on an accurate prediction of fluid properties. While it is known for subcritical pressures that nondimensionalization with the respective species critical pressures pcr and temperatures Tcr only collapses coexistence line data for simple fluids, this approach is used for Widom lines of all fluids. However, we show here that the Widom line does not adhere to the corresponding states principle, but instead to the extended corresponding states principle. We resolve this problem in two steps. First, we propose a Widom line functional based on the Clapeyron equation and derive an analytical, species specific expression for the only parameter from the Soave-Redlich-Kwong equation of state. This parameter is a function of the acentric factor ω and compares well with experimental data. Second, we introduce the scaled reduced pressure pr* to replace the previously used reduced pressure pr=p /pcr . We show that pr* is a function of the acentric factor only and can thus be readily determined from fluid property tables. It collapses both subcritical coexistence line and supercritical Widom line data over a wide range of species with acentric factors ranging from -0.38 (helium) to 0.34 (water), including alkanes up to n-hexane. By using pr*, the extended corresponding states principle can be applied within corresponding states principle formalism. Furthermore, pr* provides a theoretical foundation to compare Widom lines of different fluids.
Charter School Path Paved with Choice, Compromise, Common Sense
ERIC Educational Resources Information Center
Junge, Ember Reichgott
2014-01-01
A state legislator who played a key role in enacting the nation's first charter school law in Minnesota tells the story of shaping the ideas and the bill. She now looks for ways that charter schools can coexist with traditional public schools to deliver a better education for all children.
Children with Epilepsy in School: Special Service Usage and Assessment Practices
ERIC Educational Resources Information Center
Wodrich, David L.; Kaplan, Allen M.; Deering, William M.
2006-01-01
Special services usage and related assessment procedures were investigated for 50 students with epilepsy. Fifty-six percent of students with epilepsy received special education services, with mental retardation designation and self-contained placement common, especially among individuals with epilepsy plus a coexisting neurological diagnosis.…
Bipolar Disorder in Children: Implications for Speech-Language Pathologists
ERIC Educational Resources Information Center
Quattlebaum, Patricia D.; Grier, Betsy C.; Klubnik, Cynthia
2012-01-01
In the United States, bipolar disorder is an increasingly common diagnosis in children, and these children can present with severe behavior problems and emotionality. Many studies have documented the frequent coexistence of behavior disorders and speech-language disorders. Like other children with behavior disorders, children with bipolar disorder…
The Coexistence of Natural and Supernatural Explanations across Cultures and Development
ERIC Educational Resources Information Center
Legare, Cristine H.; Evans, E. Margaret; Rosengren, Karl S.; Harris, Paul L.
2012-01-01
Although often conceptualized in contradictory terms, the common assumption that natural and supernatural explanations are incompatible is psychologically inaccurate. Instead, there is considerable evidence that the same individuals use both natural and supernatural explanations to interpret the very same events and that there are multiple ways in…
Revealing Preconditions for Trustful Collaboration in CSCL
ERIC Educational Resources Information Center
Gerdes, Anne
2010-01-01
This paper analyses preconditions for trust in virtual learning environments. The concept of trust is discussed with reference to cases reporting trust in cyberspace and through a philosophical clarification holding that trust in the form of self-surrender is a common characteristic of all human co-existence. In virtual learning environments,…
Coexisting with fire: Ecosystems, people, and collaboration
Merrill R. Kaufmann; Ayn Shlisky; Jeffrey J. Brooks; Brian Kent
2009-01-01
We are in a "fire crisis." Many regions of the world are experiencing larger, more frequent, and more severe fires that threaten people's lives, livelihoods, and properties, and the health of ecosystems. Regardless of the causes of this crisis - a common threat that crosses cultural and geographical boundaries - societies need informed and...
Vascular Variations Associated with Intracranial Aneurysms.
Orakdogen, Metin; Emon, Selin Tural; Somay, Hakan; Engin, Taner; Is, Merih; Hakan, Tayfun
2017-01-01
To investigate the vascular variations in patients with intracranial aneurysm in circle of Willis. We used the data on 128 consecutive intracranial aneurysm cases. Cerebral angiography images were analyzed retrospectively. Arteries were grouped as anterior cerebral arterial system (ACS), posterior cerebral arterial system (PCS) and middle cerebral arterial system (MCS) for grouping vascular variations. Lateralization, being single/multiple, gender; and also any connection with accompanying aneurysms" number, localization, dimension, whether bleeding/incidental aneurysm has been inspected. Variations were demonstrated in 57.8% of the cases. The most common variation was A1 variation (34.4%). The rate of variations was 36.7%, 24.2% and 10.2% respectively in ACS, PCS and MCS. MCS variations were significantly higher in males. Anterior communicating artery (ACoA) aneurysm observance rates were significantly higher and posterior communicating artery (PCoA) aneurysm and middle cerebral artery (MCA) aneurysm observance rates were significantly lower when compared to "no ACS variation detected" cases. In "PCS variation detected" cases, PCoA aneurysm observance rates and coexistence of multiple variations were significantly higher. The rate of vascular variations in patients with aneurysms was 57.8%. Arterial hypoplasia and aplasia were the most common variations. ACS was the most common region that variations were located in; they were mostly detected on the right side. Coexistence of ACoA aneurysm was higher than PCoA and MCA aneurysms. In the PCS variations group, PCoA aneurysms were the most common aneurysms that accompanying the variation and multiple variations were more common than in the other two groups. The variations in MCS were most common in males.
Diffusive Public Goods and Coexistence of Cooperators and Cheaters on a 1D Lattice
Scheuring, István
2014-01-01
Many populations of cells cooperate through the production of extracellular materials. These materials (enzymes, siderophores) spread by diffusion and can be applied by both the cooperator and cheater (non-producer) cells. In this paper the problem of coexistence of cooperator and cheater cells is studied on a 1D lattice where cooperator cells produce a diffusive material which is beneficial to the individuals according to the local concentration of this public good. The reproduction success of a cell increases linearly with the benefit in the first model version and increases non-linearly (saturates) in the second version. Two types of update rules are considered; either the cooperative cell stops producing material before death (death-production-birth, DpB) or it produces the common material before it is selected to die (production-death-birth, pDB). The empty space is occupied by its neighbors according to their replication rates. By using analytical and numerical methods I have shown that coexistence of the cooperator and cheater cells is possible although atypical in the linear version of this 1D model if either DpB or pDB update rule is assumed. While coexistence is impossible in the non-linear model with pDB update rule, it is one of the typical behaviors in case of the non-linear model with DpB update rule. PMID:25025985
Inferring biodiversity maintenance mechanisms from ecological pattern
NASA Astrophysics Data System (ADS)
Ostling, Annette
Among a set of competitors for a single common resource, the best will simply exclude the others. Yet in nature we can see astounding diversity of competing species. Do close similarities in species' response to the local environment primarily explain their coexistence? Or is this diversity possible because of differences between species that stabilize their coexistence? And if so, what particular differences between species are important in particular communities? Some ecological communities lend themselves to experimental manipulation to begin to answer these questions. Yet for many other communities, such as tree species in forests, the logistical hurdles to this approach are daunting. Faster progress could be made in ecology if insight into biodiversity maintenance mechanisms could be gained from patterns exhibited in local ecological communities, such as how coexisting species are distributed in their ecological traits and relative abundance. Hurdles that we need to overcome to be able to gain such insight include: 1) further developing neutral theory, a quantitative process-based null model of community pattern resulting when species similarities are what allow their coexistence, and 2) better understanding what patterns to expect when species differences dominate instead, particularly in the context of stochasticity and immigration. I will describe our ongoing research to overcome these hurdles, to provide better tools for analyzing observed pattern. National Science Foundation Advancing Theory in Biology Grant 1038678, Danish National Research Foundation Grant DNRF 96 for the Center of Macroecology, Evolution and Climate.
Dickman, Amy J.; Macdonald, Ewan A.; Macdonald, David W.
2011-01-01
One of the greatest challenges in biodiversity conservation today is how to facilitate protection of species that are highly valued at a global scale but have little or even negative value at a local scale. Imperiled species such as large predators can impose significant economic costs at a local level, often in poverty-stricken rural areas where households are least able to tolerate such costs, and impede efforts of local people, especially traditional pastoralists, to escape from poverty. Furthermore, the costs and benefits involved in predator conservation often include diverse dimensions, which are hard to quantify and nearly impossible to reconcile with one another. The best chance of effective conservation relies upon translating the global value of carnivores into tangible local benefits large enough to drive conservation “on the ground.” Although human–carnivore coexistence involves significant noneconomic values, providing financial incentives to those affected negatively by carnivore presence is a common strategy for encouraging such coexistence, and this can also have important benefits in terms of reducing poverty. Here, we provide a critical overview of such financial instruments, which we term “payments to encourage coexistence”; assess the pitfalls and potentials of these methods, particularly compensation and insurance, revenue-sharing, and conservation payments; and discuss how existing strategies of payment to encourage coexistence could be combined to facilitate carnivore conservation and alleviate local poverty. PMID:21873181
Monolayer phase coarsening using oscillatory flow
NASA Astrophysics Data System (ADS)
Leung, J.; Lopez, J. M.; Vogel, M. J.
2005-11-01
The co-existing phase domains of monolayers commonly observed via microscope are examined on flowing systems. Recent evidence shows that co-existing phase domains have profound effects on monolayer response to bulk flow. The present flow geometry consists of an open-top rectangular cavity in which the flow is driven by the periodic oscillation of the floor in its own plane. The oscillation of the floor dilates and compresses any film at the gas/liquid interface while still maintaining an essentially flat interface. A range of flow conditions (oscillation frequency and amplitude) is chosen so that the flow remains essentially two-dimensional. Measurements at the interface, initially covered by an insoluble monolayer (vitamin K1 or stearic acid), are made using a Brewster angle microscope system with a pulsed laser. Various phenomena such as fragmentation (breaking up of co-existing domains into finer ones) had previously been observed in sheared monolayer flows. In this new flow regime, we have seen dramatic coarsening of the domains. Interesting relaxation behavior at short and long time scales will also be discussed.
Ito, Kazuaki; Takayama, Yohichi; Makabe, Nobuyuki; Mitsui, Ryo; Hirokawa, Takeshi
2005-08-12
A fast and highly sensitive ion chromatographic method using monolithic ODS columns was developed for the determination of nitrite (NO2-) and nitrate (NO3-) in seawater. Two monolithic ODS columns (50 mm x 4.6 mm i.d. + 100 mm x 4.6 mm i.d.) connected in series were coated and equilibrated with 5 mM cetyltrimethylammonium chloride (CTAC) aqueous solution. The column efficiency with 0.5 M NaCl as the mobile phase did not decrease in spite of the increase in flow rate of the mobile phase. Thus, good chromatograms were obtained within 3 minutes for NO2- and NO3 in artificial seawater without interferences by coexisting ions. The detection limit (S/N = 3) with UV detection at 225 nm was 0.8 and 1.6 microg/L for NO2- and NO3-, respectively. The characteristics of the monolithic CTA(+)-coated ODS columns were discussed. The present method was successfully applied to the fast and sensitive determination of NO2- and NO3- in real seawater samples.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Groves, D.J.; Short, H.; Thewaini, A.J.
Staphylococci were isolated from rural and urban populations in Iraq, which were not known to be exposed to either heavy metals or antibiotics. The antibiotic and heavy metal resistance patterns of these strains were analyzed in both mannitol-fermenting and nonfermenting strains. Over 90% of the strains were resistant to at least one of the following antibiotics: penicillin, chloramphenicol, erythromycin, tetracycline, cephalothin, lincomycin, and methicillin. In general, mannitol-fermenting strains were resistant to penicillin and cupric ions. Mannitol-negative strains were more frequently associated with mercuric ion and tetracycline resistance. Although resistance to penicillin and tetracycline can coexist, the combination of penicillin resistancemore » and tetracycline resistance usually occurred in mannitol-negative strains. The possibility of selection of heavy metal-resistant strains due to exposure to toxic levels of methylmercury was examined. No significant increase in mercuric ion-resistant strains of staphylococci or Escherichia coli were detected in exposed populations as compared to control groups. The possible reasons for this result are discussed.« less
Separation of thorium ions from wolframite and scandium concentrates using graphene oxide.
Jankovský, Ondřej; Sedmidubský, David; Šimek, Petr; Klímová, Kateřina; Bouša, Daniel; Boothroyd, Chris; Macková, Anna; Sofer, Zdeněk
2015-10-14
The separation of rare metals from the ores and commercially available compounds is an important issue due to the need of their high purity in advanced materials and devices. Important examples of two highly important elements that co-exist in the ores are scandium and thorium. Scandium containing ores and consequently also commercially available scandium compounds often contain traces of thorium which is very difficult to separate. We used graphene oxide for the selective sorption of thorium ions from scandium and thorium mixtures originating from the mined ores as well as from commercially available scandium salts. Our results showed that graphene oxide has an extreme affinity towards thorium ions. After the sorption process the graphene oxide contained over 20 wt% of thorium while the amount of scandium sorbed on GO was very low. This phenomenon of high sorption selectivity of graphene oxide can be applied in industry for the purification of various chemicals containing scandium and for separation of thorium containing mixtures. Alternatively, this methodology can be used for preconcentration of thorium from low-grade ores and its further use in the new generation of nuclear reactors.
A rare coexistence of aspergillosis with actinomycosis.
Vinay, B Hari; Mohan, Aditya; Haritha, P; Lakshmi, K Roja
2017-01-01
Aspergillosis is a common systemic mycosis which affects immunocompromised and immunocompetent hosts. Aspergillus spp. is wide spread in the environment in most countries, which renders an invasive form of disease. The presence conidial heads are pathognomic to aspergillosis in diagnosis. Actinomycosis is a subacute-to-chronic infection that causes sinus fistula, tract or abscess due to the invasion surrounding the soft tissue. Cervicofacial infection accounts for 50%-60% of all actinomycosis cases. The mandible and nasopharynx are the sites of predilection, but maxillary infection is rare. Aspergillosis and Actinomycosis each of them was reported in case, but mixed infection of both organisms is rare, only one case has been reported. This paper discussed about a case report of coexistence of aspergillosis with actinomycosis in 38-year-old male.
Sun, Yuanyuan; Yue, Qinyan; Mao, Yanpeng; Gao, Baoyu; Gao, Yuan; Huang, Lihui
2014-01-30
FeCl3, AlCl3 and MnCl2 were used as the assisted activation agent in activated carbon preparation by H3PO4 activation using microwave heating method. The physico-chemical properties of activated carbons were investigated by scanning electron microscope (SEM), N2 adsorption/desorption, Boehm's titration, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). To investigate the adsorption performances of chromium onto these newly developed activated carbons, a batch of experiments were performed under different adsorption conditions: solution pH, initial Cr(VI) ion concentration, contact time and co-existing ions. The results suggested that carbon with MnCl2 as assisted activation agent displayed the highest BET surface area (1332m(2)/g) and the highest pore volume (1.060cm(3)/g). FeCl3, AlCl3 and MnCl2 had successfully improved Cr(VI) adsorption and activated carbon with FeCl3 as assisted activation agent exhibited the best uptake capacity. To study the transformation of Cr(VI) in adsorption process, total chromium in the aqueous solution was also recorded. The ratio of the amount of Cr(VI) to Cr(III) on each adsorbent was explained by XPS analysis results. Both the co-existing salts (Na2SO4 and NaNO3) demonstrated promoted effects on Cr(VI) removal by four carbons. The pseudo-second-order model and Freundlich equation displayed a good correlation with adsorption data. Copyright © 2013 Elsevier B.V. All rights reserved.
Verma, Akash; Goh, Kee San; Phua, Chee Kiang; Sim, Wen Yuan; Tee, Kuan Sen; Lim, Albert Y.H.; Tai, Dessmon Y.H.; Goh, Soon Keng; Kor, Ai Ching; Ho, Benjamin; Lew, Sennen J.W.; Abisheganaden, John
2016-01-01
Abstract To compare the performance of convex probe endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) with conventional endobronchial biopsy (EBB) or transbronchial lung biopsy (TBLB) in patients with mediastinal, and coexisting endobronchial or peripheral lesions. Retrospective review of records of patients undergoing diagnostic EBUS-TBNA and conventional bronchoscopy in 2014. A total of 74 patients had mediastinal, and coexisting endobronchial or peripheral lesions. The detection rate of EBUS-TBNA for mediastinal lesion >1 cm in short axis, EBB for visible exophytic type of endobronchial lesion, and TBLB for peripheral lesion with bronchus sign were 71%, 75%, and 86%, respectively. In contrast, the detection rate of EBUS-TBNA for mediastinal lesion ≤1 cm in short axis, EBB for mucosal hyperemia type of endobronchial lesion, and TBLB for peripheral lesion without bronchus sign were 25%, 63%, and 38%, and improved to 63%, 88%, and 62% respectively by adding EBB or TBLB to EBUS-TBNA, and EBUS-TBNA to EBB or TBLB. Postprocedure bleeding was significantly more common in patients undergoing EBB and TBLB 8 (40%) versus convex probe EBUS-TBNA 2 patients (2.7%, P = 0.0004). EBUS-TBNA is a safer single diagnostic technique compared with EBB or TBLB in patients with mediastinal lesion of >1 cm in size, and coexisting exophytic type of endobronchial lesion, or peripheral lesion with bronchus sign. However, it requires combining with EBB or TBLB and vice versa to optimize yield when mediastinal lesion is ≤1 cm in size, and coexisting endobronchial and peripheral lesions lack exophytic nature, and bronchus sign, respectively. PMID:27977603
Morphological similarity and ecological overlap in two rotifer species.
Gabaldón, Carmen; Montero-Pau, Javier; Serra, Manuel; Carmona, María José
2013-01-01
Co-occurrence of cryptic species raises theoretically relevant questions regarding their coexistence and ecological similarity. Given their great morphological similitude and close phylogenetic relationship (i.e., niche retention), these species will have similar ecological requirements and are expected to have strong competitive interactions. This raises the problem of finding the mechanisms that may explain the coexistence of cryptic species and challenges the conventional view of coexistence based on niche differentiation. The cryptic species complex of the rotifer Brachionus plicatilis is an excellent model to study these questions and to test hypotheses regarding ecological differentiation. Rotifer species within this complex are filtering zooplankters commonly found inhabiting the same ponds across the Iberian Peninsula and exhibit an extremely similar morphology-some of them being even virtually identical. Here, we explore whether subtle differences in body size and morphology translate into ecological differentiation by comparing two extremely morphologically similar species belonging to this complex: B. plicatilis and B. manjavacas. We focus on three key ecological features related to body size: (1) functional response, expressed by clearance rates; (2) tolerance to starvation, measured by growth and reproduction; and (3) vulnerability to copepod predation, measured by the number of preyed upon neonates. No major differences between B. plicatilis and B. manjavacas were found in the response to these features. Our results demonstrate the existence of a substantial niche overlap, suggesting that the subtle size differences between these two cryptic species are not sufficient to explain their coexistence. This lack of evidence for ecological differentiation in the studied biotic niche features is in agreement with the phylogenetic limiting similarity hypothesis but requires a mechanistic explanation of the coexistence of these species not based on differentiation related to biotic niche axes.
Kneitel, Jamie M
2012-01-01
Trade-offs among species' ecological interactions is a pervasive explanation for species coexistence. The traits associated with trade-offs are typically measured to mechanistically explain species coexistence at a single spatial scale. However, species potentially interact at multiple scales and this may be reflected in the traits among coexisting species. I quantified species' ecological traits associated with the trade-offs expected at both local (competitive ability and predator tolerance) and regional (competitive ability and colonization rate) community scales. The most common species (four protozoa and a rotifer) from the middle trophic level of a pitcher plant (Sarracenia purpurea) inquiline community were used to link species traits to previously observed patterns of species diversity and abundance. Traits associated with trade-offs (competitive ability, predator tolerance, and colonization rate) and other ecological traits (size, growth rate, and carrying capacity) were measured for each of the focal species. Traits were correlated with one another with a negative relationship indicative of a trade-off. Protozoan and rotifer species exhibited a negative relationship between competitive ability and predator tolerance, indicative of coexistence at the local community scale. There was no relationship between competitive ability and colonization rate. Size, growth rate, and carrying capacity were correlated with each other and the trade-off traits: Size was related to both competitive ability and predator tolerance, but growth rate and carrying capacity were correlated with predator tolerance. When partial correlations were conducted controlling for size, growth rate and carrying capacity, the trade-offs largely disappeared. These results imply that body size is the trait that provides the basis for ecological interactions and trade-offs. Altogether, this study showed that the examination of species' traits in the context of coexistence at different scales can contribute to our understanding of the mechanisms underlying community structure.
Partial migration and transient coexistence of migrants and residents in animal populations.
Singh, Navinder J; Leonardsson, Kjell
2014-01-01
Partial migration, whereby a proportion of the population migrates, is common across the animal kingdom. Much of the focus in the literature has been on trying to explain the underlying mechanisms for the coexistence of migrants and residents. In addition, there has been an increasing number of reports on the prevalence and frequency of partially migratory populations. One possible explanation for the occurrence of partial migration, which has received no attention in the literature, is that of 'transient coexistence' during the invasion phase of a superior behaviour. In this study we develop a theoretical basis for explaining partial migration as a transient coexistence and derive a method to predict the frequency of residents and migrants in partially migrating populations. This method is useful to predict the frequencies of migrants and residents in a small set of populations as a complementing hypothesis to 'an Evolutionary Stable Strategy (ESS)'. We use the logistic growth equation to derive a formula for predicting the frequencies of residents and migrants. We also use simulations and empirical data from white perch (Morone americana), moose (Alces alces) and red deer (Cervus elaphus) to demonstrate our approach. We show that the probability of detecting partial migration due to transient coexistence depends upon a minimum number of tracked or marked individuals for a given number of populations. Our approach provides a starting point in searching for explanations to the observed frequencies, by contrasting the observed pattern with both the predicted transient and the uniform random pattern. Aggregating such information on observed patterns (proportions of migrants and residents) may eventually lead to the development of a quantitative theory for the equilibrium (ESS) populations as well.
Hicks, Gregory E; Sions, J Megan; Velasco, Teonette O
2017-10-27
To determine (1) whether there are differences in the prevalence of clinical hip symptoms between older adults with and without chronic low back pain (CLBP); and (2) whether coexisting hip symptoms are associated with worse physical performance and poorer health-related quality of life (HRQOL). Case-control study. Individuals participated in a standardized evaluation in a clinical laboratory. Clinical hip symptoms, which are proposed predictors of radiographic hip osteoarthritis according to American College of Rheumatology guidelines, were evaluated in a volunteer sample of community-dwelling older adults with CLBP (n=54; aged 60-85y) and in age- and sex-matched healthy controls (n=54). Not applicable. Physical performance was measured by the repeated chair rise test and stair-climbing test. HRQOL was measured by the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Hip joint pain, morning stiffness, and pain with hip internal rotation were more common among older adults with CLBP (P<.05). Participants with CLBP and coexisting hip symptoms had worse physical performance than individuals without CLBP or hip symptoms (P<.0001). Additionally, the presence of coexisting hip symptoms was associated with worse HRQOL, particularly in the domains of social functioning, mental health, and role limitations attributable to emotional problems as measured by the SF-36 (P<.01). Given our limited understanding of CLBP among older adults, there is a definitive need to systematically explore coexisting pain conditions that may contribute to worse outcomes. Based on these data, future longitudinal studies should explore whether coexisting hip symptoms are associated with a worse prognosis in older adults with CLBP. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
Goldstone, Andrew B; Howard, Jessica L; Cohen, Jeffrey E; MacArthur, John W; Atluri, Pavan; Kirkpatrick, James N; Woo, Y Joseph
2014-12-01
The management of coexistent tricuspid regurgitation in patients with mitral regurgitation remains controversial. We sought to define the incidence and natural history of coexistent tricuspid regurgitation in patients undergoing isolated mitral surgery for degenerative mitral regurgitation, as well as the effect of late secondary tricuspid regurgitation on cardiovascular symptom burden and survival. To minimize confounding, analysis was limited to 495 consecutive patients who underwent isolated mitral surgery for degenerative mitral valve disease between 2002 and 2011. Patients with coexistent severe tricuspid regurgitation were excluded because such patients typically undergo concomitant tricuspid intervention. Grade 1 to 3 coexistent tricuspid regurgitation was present in 215 patients (43%) preoperatively. Actuarial freedom from grade 3 to 4 tricuspid regurgitation 1, 5, and 9 years after surgery was 100% ± 0%, 90% ± 2%, and 64% ± 7%, respectively. Older age (P < .001) and grade of preoperative tricuspid regurgitation (P = .006) independently predicted postoperative progression of tricuspid regurgitation on multivariable analysis. However, when limited to patients with mild or absent tricuspid regurgitation, indexed tricuspid annular diameter was the only significant risk factor for late tricuspid regurgitation (P = .04). New York Heart Association functional class and long-term survival did not worsen with development of late secondary tricuspid regurgitation (P = .4 and P = .6, respectively). However, right ventricular dysfunction was significantly more common in patients with more severe late tricuspid regurgitation (P = .007). Despite durable correction of degenerative mitral regurgitation, less than severe tricuspid regurgitation is likely to progress after surgery if uncorrected. Given the low incremental risk of tricuspid annuloplasty, a more aggressive strategy of concomitant tricuspid repair may be warranted. Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.
Prevalence of endometrial polyps coexisting with uterine fibroids and associated factors
Kınay, Tuğba; Öztürk Başarır, Zehra; Fırtına Tuncer, Serap; Akpınar, Funda; Kayıkçıoğlu, Fulya; Koç, Sevgi
2016-01-01
Objective: The aim of the study was to investigate the prevalence of endometrial polyps in patients with uterine fibroids and associated factors of coexistence of these two pathologies. Materials and Methods: The medical records of 772 patients who underwent hysterectomy because of uterine fibroids were retrospectively reviewed. Patients were divided into two groups according to the presence of endometrial polyps in the histopathologic examination. Demographic, clinical and histopathologic findings of the patients with and without endometrial polyps were compared. Student’s t-test, Mann-Whitney U test, Pearson’s Chi-square test, and logistic regression analysis were used for statistical analysis. Results: The prevalence of the endometrial polyps in uterine fibroid cases was found 20.1% (n=155). Age ≥45 years (odds ratio [OR] 1.61; 95% confidence interval [CI]: [1.06-2.44]; p=0.014), presence of hypertension (23.9% vs. 17.5%; p=0.047), endometrial hyperplasia (OR 4.00; 95% CI: [1.92-8.33]; p<0.001) and cervical polyps (OR 3.13; 95% CI: [1.69-5.88]; p<0.001) were significantly associated with the coexistence of endometrial polyps and uterine fibroids. Endometrial polyps were more common in patients with ≥2 fibroids (p=0.023) and largest fibroid <8 cm (p=0.009). A negative correlation was found between condom use and endometrial polyps (8.1% vs. 3.9%; p=0.044). Conclusions: The prevalence of the endometrial polyps coexisting with uterine fibroids was 20.1%. Age, hypertension, endometrial hyperplasia, cervical polyps, and number of fibroids were positively correlated; condom use and size of largest fibroid were negatively correlated with the coexistence of these two pathologies. PMID:28913086
Morphological Similarity and Ecological Overlap in Two Rotifer Species
Gabaldón, Carmen; Montero-Pau, Javier; Serra, Manuel; Carmona, María José
2013-01-01
Co-occurrence of cryptic species raises theoretically relevant questions regarding their coexistence and ecological similarity. Given their great morphological similitude and close phylogenetic relationship (i.e., niche retention), these species will have similar ecological requirements and are expected to have strong competitive interactions. This raises the problem of finding the mechanisms that may explain the coexistence of cryptic species and challenges the conventional view of coexistence based on niche differentiation. The cryptic species complex of the rotifer Brachionus plicatilis is an excellent model to study these questions and to test hypotheses regarding ecological differentiation. Rotifer species within this complex are filtering zooplankters commonly found inhabiting the same ponds across the Iberian Peninsula and exhibit an extremely similar morphology—some of them being even virtually identical. Here, we explore whether subtle differences in body size and morphology translate into ecological differentiation by comparing two extremely morphologically similar species belonging to this complex: B. plicatilis and B. manjavacas. We focus on three key ecological features related to body size: (1) functional response, expressed by clearance rates; (2) tolerance to starvation, measured by growth and reproduction; and (3) vulnerability to copepod predation, measured by the number of preyed upon neonates. No major differences between B. plicatilis and B. manjavacas were found in the response to these features. Our results demonstrate the existence of a substantial niche overlap, suggesting that the subtle size differences between these two cryptic species are not sufficient to explain their coexistence. This lack of evidence for ecological differentiation in the studied biotic niche features is in agreement with the phylogenetic limiting similarity hypothesis but requires a mechanistic explanation of the coexistence of these species not based on differentiation related to biotic niche axes. PMID:23451154
Modification of nanostructured calcium carbonate for efficient gene delivery.
Zhao, Dong; Wang, Chao-Qun; Zhuo, Ren-Xi; Cheng, Si-Xue
2014-06-01
In this study, a facile method to modify nanostructured calcium carbonate (CaCO3) gene delivery systems by adding calcium phosphate (CaP) component was developed. CaCO3/CaP/DNA nanoparticles were prepared by the co-precipitation of Ca(2+) ions with plasmid DNA in the presence of carbonate and phosphate ions. For comparison, CaCO3/DNA nanoparticles and CaP/DNA co-precipitates were also prepared. The effects of carbonate ion/phosphate ion (CO3(2-)/PO4(3-)) ratio on the particle size and gene delivery efficiency were investigated. With an appropriate CO3(2-)/PO4(3-) ratio, the co-existence of carbonate and phosphate ions could control the size of co-precipitates effectively, and CaCO3/CaP/DNA nanoparticles with a decreased size and improved stability could be obtained. The in vitro gene transfections mediated by different nanoparticles in 293T cells and HeLa cells were carried out, using pGL3-Luc as a reporter plasmid. The gene transfection efficiency of CaCO3/CaP/DNA nanoparticles could be significantly improved as compared with CaCO3/DNA nanoparticles and CaP/DNA co-precipitates. The confocal microscopy study indicated that the cellular uptake and nuclear localization of CaCO3/CaP/DNA nanoparticles were significantly enhanced as compared with unmodified CaCO3/DNA nanoparticles. Copyright © 2014 Elsevier B.V. All rights reserved.
Sawtooth control in fusion plasmas
NASA Astrophysics Data System (ADS)
Graves, J. P.; Angioni, C.; Budny, R. V.; Buttery, R. J.; Coda, S.; Eriksson, L.-G.; Gimblett, C. G.; Goodman, T. P.; Hastie, R. J.; Henderson, M. A.; Koslowski, H. R.; Mantsinen, M. J.; Martynov, An; Mayoral, M.-L.; Mück, A.; Nave, M. F. F.; Sauter, O.; Westerhof, E.; Contributors, JET–EFDA
2005-12-01
Clear observations of early triggering of neo-classical tearing modes by sawteeth with long quiescent periods have motivated recent efforts to control, and in particular destabilize, sawteeth. One successful approach explored in TCV utilizes electron cyclotron heating in order to locally increase the current penetration time in the core. The latter is also achieved in various machines by depositing electron cyclotron current drive or ion cyclotron current drive close to the q = 1 rational surface. Crucially, localized current drive also succeeds in destabilizing sawteeth which are otherwise stabilized by a co-existing population of energetic trapped ions in the core. In addition, a recent reversed toroidal field campaign at JET demonstrates that counter-neutral beam injection (NBI) results in shorter sawtooth periods than in the Ohmic regime. The clear dependence of the sawtooth period on the NBI heating power and the direction of injection also manifests itself in terms of the toroidal plasma rotation, which consequently requires consideration in the theoretical interpretation of the experiments. Another feature of NBI, expected to be especially evident in the negative ion based neutral beam injection (NNBI) heating planned for ITER, is the parallel velocity asymmetry of the fast ion population. It is predicted that a finite orbit effect of asymmetrically distributed circulating ions could strongly modify sawtooth stability. Furthermore, NNBI driven current with non-monotonic profile could significantly slow down the evolution of the safety factor in the core, thereby delaying sawteeth.
NO Chemisorption on Cu/SSZ-13: a Comparative Study from Infrared Spectroscopy and DFT Calculations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, Renqin; McEwen, Jean-Sabin; Kollar, Marton
The locations and energies of Cu ions in a Cu/SSZ-13 zeolite catalyst were investigated by density functional theory (DFT) calculations. For 'naked' Cu2+ ions (i.e., Cu2+ ions with no ligands in their coordination spheres other than zeolite lattice oxygen atoms), the more energetically favorable sites are within a 6-membered ring. However, with the presence of various adsorbates, the energy difference between 6- and 8-membered ring locations greatly diminishes. Specifically, Cu2+ ions are substantially stabilized by -OH ligands (as [CuII(OH)]+), making the extra-framework sites in an 8-membered ring energetically more favorable than 6-membered ring sites. Under fully dehydrated high vacuum conditionsmore » with different Si/Al and Cu/Al ratios, three chemisorbed NO species coexist upon exposure of NO to Cu/SSZ-13: NO+, Cu2+-NO and Cu+-NO. The relative signal intensities for these bands vary greatly with Si/Al ratios. The vibrational frequency of chemisorbed NO was found to be very sensitive to the location of Cu2+ ions. On the one hand, with the aid from DFT calculations, the nature for these vibrations can be assigned in detail. On the other hand, the relative intensities for various Cu2+-NO species provide a good measure of the nature of Cu2+ ions as functions of Si/Al and Cu/Al ratios and the presence of humidity. These new findings cast doubt on the generally accepted proposal that only Cu2+ ions located in 6-membered rings are catalytically active for NH3-SCR.« less
Spectroscopic and DFT study of atenolol and metoprolol and their copper complexes
NASA Astrophysics Data System (ADS)
Cozar, O.; Szabó, L.; Cozar, I. B.; Leopold, N.; David, L.; Căinap, C.; Chiş, V.
2011-05-01
IR, Raman and surface-enhanced Raman scattering (SERS) spectra of atenolol (ATE) and metoprolol (MET) were recorded and assigned on the basis of density functional theory (DFT) calculations. A reliable assignment of vibrational IR and Raman bands of the two compounds was possible by a proper choice of models used in quantum chemical calculations. Both molecules are adsorbed to the silver surface mainly through the oxygen atoms and π-electrons of the phenyl ring. The coordination mode of the metal ions in Cu(II)-ATE and -MET compounds was also derived from IR and EPR spectra. EPR spectra give evidence for a square-planar arrangement around the copper (II) ion in the case of Cu-ATE complex, with a N 2O 2 chromophore. Only oxygen atoms are involved in the cooper coordination for Cu-MET complex, and two types of local symmetries with d and d as ground states for paramagnetic electron coexist.
Annealing temperature effects on the magnetic properties and induced defects in C/N/O implanted MgO
NASA Astrophysics Data System (ADS)
Li, Qiang; Ye, Bonian; Hao, Yingping; Liu, Jiandang; Kong, Wei; Ye, Bangjiao
2013-02-01
Virgin MgO single crystals were implanted with 70 keV C/N/O ions at room temperature to a dose of 2 × 1017/cm2. After implantation the samples showed room temperature hysteresis in magnetization loops. The annealing effects on the magnetic properties and induced defects of these samples were determined by vibrating sample magnetometer and positron annihilation spectroscopy, respectively. The experimental results indicate that ferromagnetism can be introduced to MgO single crystals by doping with C, N or introduction of Mg related vacancy defects. However, the Mg vacancies coexistence with C or N ions in the C-/N-implanted samples may play a negative role in magnetic performance in these MgO samples. The rapid increase of magnetic moment in O-implanted sample is attributed to the formation of new type of vacancy defects.
Kosaka, Koji; Asami, Mari; Takei, Kanako; Akiba, Michihiro
2011-01-01
An analytical method for determining bromate in drinking water was developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The (18)O-enriched bromate was used as an internal standard. The limit of quantification (LOQ) of bromate was 0.2 µg/L. The peak of bromate was separated from those of coexisting ions (i.e., chloride, nitrate and sulfate). The relative and absolute recoveries of bromate in two drinking water samples and in a synthesized ion solution (100 mg/L chloride, 10 mg N/L nitrate, and 100 mg/L sulfate) were 99-105 and 94-105%, respectively. Bromate concentrations in 11 drinking water samples determined by LC-MS/MS were <0.2-2.3 µg/L. The results of the present study indicated that the proposed method was suitable for determining bromate concentrations in drinking water without sample pretreatment.
Fukushi, Keiichi; Ito, Hideyuki; Kimura, Kenichi; Yokota, Kuriko; Saito, Keiitsu; Chayama, Kenji; Takeda, Sahori; Wakida, Shin-ichi
2006-02-17
We developed capillary zone electrophoresis (CZE) with direct UV detection for determination of ammonium in environmental water samples. Ammonium in the samples was partly converted into ammonia in the alkaline background electrolyte (BGE) during migration and was detected by molecular absorption of ammonia at 190 nm in approximately 7 min. The limit of detection (LOD) for ammonium was 0.24 mg/l (as nitrogen) at a signal-to-noise ratio of three. The respective values of the relative standard deviation (RSD) of peak area, peak height, and migration time for ammonium were 2.1, 1.8, and 0.46%. Major alkali and alkaline earth metal ions coexisting in the samples did not interfere with ammonium determination by the proposed method. The proposed method determined ammonium in surface water and sewage samples. The results were compared to those obtained using ion chromatography (IC).
Kamenarska, Zornitsa; Taniguchi, Tomokazu; Ohsawa, Noboru; Hiraoka, Masanori; Itoh, Nobuya
2007-05-01
Bromoperoxidase activity was initially detected in marine macroalgae belonging to the Solieriaceae family (Gigartinales, Rhodophyta), including Solieria robusta (Greville) Kylin, Eucheuma serra J. Agardh and Kappaphycus alvarezii (Doty) Doty, which are important industrial sources of the polysaccharide carrageenan. Notably, the purification of bromoperoxidase was difficult because due to the coexistence of viscoid polysaccharides. The activity of the partially purified enzyme was dependent on the vanadate ion, and displayed a distinct substrate spectrum from that of previously reported vanadium-dependent bromoperoxidases of marine macroalgae. The enzyme was specific for Br- and I- ions and inactive toward F- and Cl-. The K(m) values for Br- and H2O2 were 2.5x10(-3) M and 8.5x10(-5) M, respectively. The halogenated product, dibromoacetaldehyde, that accumulated in K. alvarezii was additionally determined.
Description of Mixed-Phase Clouds in Weather Forecast and Climate Models
2013-09-30
energy budget and thus the melting and freezing of sea ice , both at present and into the future. RELATED PROJECTS This project is a follow-up...Arctic sea - ice in late summer, Atmos. Chem. Phys. Discuss., 13, 13191-13244, doi: 10.5194/acpd-13-13191-2013. Sotiropoulou, G., M. Tjernström, J. Sedlar...common, by far the most common cloud type over the Arctic, when thermodynamic principles suggest that ice and liquid particles cannot coexist for
La ensenanza de idiomas en Puerto Rico (Language Teaching in Puerto Rico)
ERIC Educational Resources Information Center
Llorens, Washington
1976-01-01
The poor command of Spanish common to many Puerto Ricans is due, not to the teaching of English as a second language, but to the poor instruction of the native language and the lack of emphasis on reading good Spanish literature. The two languages can coexist. (Text is in Spanish.) (CHK)
USDA-ARS?s Scientific Manuscript database
Like common bacteriophages, Shiga toxin-producing Escherichia coli (STEC) bacteriophages are viruses that recognize and bind to specific bacterial host (STEC) for propagation. They co-exist with STEC hosts, which cause epidemic food and waterborne illnesses, but may act as host populations limiting ...
Alex Royo; Chris J. Peterson; John S. Stanovick; Walter P. Carson
2016-01-01
Salvage logging following windthrow is common throughout forests worldwide even though the practice is often considered inimical to forest recovery. Because salvaging removes trees, crushes seedlings, and compacts soils, many warn this practice may delay succession, suppress diversity, and alter composition. Here, over 8 yr following windthrow, we experimentally...
ERIC Educational Resources Information Center
Kirov, Roumen; Kinkelbur, Joerg; Banaschewski, Tobias; Rothenberger, Aribert
2007-01-01
Background: In children, attention-deficit/hyperactivity disorder (ADHD), tic disorder (TD), and their coexistence (ADHD + TD comorbidity) are very common and clinically important. Associated sleep patterns and their clinical role are still insufficiently investigated. This study aimed at characterizing these sleep patterns in children with ADHD,…
Sjögren syndrome and neuromyelitis optica spectrum disorder co-exist in a common autoimmune milieu.
Carvalho, Diogo C; Tironi, Tauana S; Freitas, Denise S; Kleinpaul, Rodrigo; Talim, Natalia C; Lana-Peixoto, Marco A
2014-08-01
The relationship between Sjögren's syndrome (SS) and neuromyelitis optica spectrum disorder (NMOSD) is not completely understood. We report two patients with both conditions and review 47 other previously reported cases meeting currently accepted diagnostic criteria, from 17 articles extracted from PubMed. Out of 44 patients whose gender was informed, 42 were females. Mean age at onset of neurological manifestation was 36.2 years (10-74). Serum anti-AQP4-IgG was positive in 32 patients, borderline in 1, and negative in 4. Our Case 1 was seronegative for AQP4-IgG and had no non-organ-specific autoantibodies other than anti-SSB antibodies. Our Case 2 had serum anti-AQP4, anti-SSA/SSB, anti-thyreoglobulin and anti-acethylcholine-receptor antibodies, as well as clinical hypothyreoidism, but no evidence of myasthenia gravis. Our Cases and others, as previously reported in literature, with similar heterogeneous autoimmune response to aquaporin-4, suggest that SS and NMO co-exist in a common autoimmune milieu which is not dependent on aquaporin-4 autoimmunity.
Li, Jian; Xie, Xing-Mei; Liao, Can; Li, Dong-Zhi
2014-12-01
To determine the prevalence of α-thalassaemia in β-thalassaemia individuals in a Chinese population. The standard diagnostic marker for β-thalassaemia was elevation of the Hb A2 level (>3.5%) with low mean corpuscular volume. The common α-thalassaemia mutations were studied by molecular analysis in all identified β-thalassaemia carriers. A prevalence rate of 3.3% for β-thalassaemia was found in our population; α- and β-thalassaemia interactions were found to co-exist in 17.8% of the β-thalassaemia carriers. The -SEA deletion was the most common α-thalassaemia mutation co-inherited with β-thalassaemia, followed by the -α3.7 deletion, the -α4.2 deletion, Hb Quong Sze, and Hb Constant Spring. Our results suggest that it could be valuable to study co-existing α-globin mutations in subjects with β-thalassaemia trait in a prenatal screening programme, especially in populations with a high prevalence of haemoglobinopathies. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
Sun, Jieping; Liang, Qionglin; Han, Qiang; Zhang, Xiaoqiong; Ding, Mingyu
2015-01-01
A novel magnetic graphene oxide nanocomposite was synthesized by one-step coprecipitation method and characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and vibrating sample magnetometer. The nanocomposite beard many intriguing properties, including chemical stability, high adsorption capacity, and superparamagnetic. These properties evoked great interest and desire of its exploration in magnetic solid-phase extraction of heavy metal ions from complex samples. Several parameters effecting the analytical performance, such as the sample pH, amounts of adsorbent, sample volumes, elution volumes, and coexisting ions, had been investigated in detail. The adsorbed metal ions were easy eluted by controlling the pH condition and the materials could be reused more than 20 times. Under the optimized conditions, the limits of detection were 0.016, 0.046, 0.395, 0.038, 0.157 μg L(-1) for Co(2+), Ni(2+), Cu(2+), Cd(2+), and Pb(2+), respectively. The intra-day relative standard deviations (n=5) were in the range of 1.8-5.5% at 10 μg L(-1). The proposed method was successfully applied to biological sample analysis and got excellent recoveries in the range of 81-113% even the matrix was complex. Copyright © 2014 Elsevier B.V. All rights reserved.
Ravikumar, Ayyanu; Panneerselvam, Perumal; Morad, Norhashimah
2018-05-24
In this paper, we propose a metal-polydopamine framework (MPDA) with specific molecular probe which appears to be the most promising approach to a strong fluorescence quencher. The MPDA framework quenching ability towards various organic fluorophore such as aminoethylcomarin acetate (AMCA), 6-carboxyfluorescein (FAM), carboxyteramethylrhodamine (TAMRA) and Cy5 are used to establish a fluorescent biosensor that can selectively recognize Hg2+ and Ag+ ion. The fluorescent quenching efficiency was sufficient to achieve more than 96%. The MPDA framework also exhibits different affinities with ssDNA and dsDNA. In addition, the FAM labelled ssDNA was adsorbed onto MPDA framework, based on their interaction with the complex formed between MPDA frameworks/ssDNA taken as a sensing platform. By taking advantage of this sensor highly sensitive and selective determination of Hg2+and Ag+ ions is achieved through Exonuclease III signal amplification activity. The detection limits of Hg2+and Ag+ achieved to be 1.2 pM and 34 pM respectively, were compared to co-existing metal ions and GO based sensors. Furthermore, the potential applications of this study establish the highly sensitive fluorescence detection targets in environmental and biological fields.
Scalable 2D Mesoporous Silicon Nanosheets for High-Performance Lithium-Ion Battery Anode.
Chen, Song; Chen, Zhuo; Xu, Xingyan; Cao, Chuanbao; Xia, Min; Luo, Yunjun
2018-03-01
Constructing unique mesoporous 2D Si nanostructures to shorten the lithium-ion diffusion pathway, facilitate interfacial charge transfer, and enlarge the electrode-electrolyte interface offers exciting opportunities in future high-performance lithium-ion batteries. However, simultaneous realization of 2D and mesoporous structures for Si material is quite difficult due to its non-van der Waals structure. Here, the coexistence of both mesoporous and 2D ultrathin nanosheets in the Si anodes and considerably high surface area (381.6 m 2 g -1 ) are successfully achieved by a scalable and cost-efficient method. After being encapsulated with the homogeneous carbon layer, the Si/C nanocomposite anodes achieve outstanding reversible capacity, high cycle stability, and excellent rate capability. In particular, the reversible capacity reaches 1072.2 mA h g -1 at 4 A g -1 even after 500 cycles. The obvious enhancements can be attributed to the synergistic effect between the unique 2D mesoporous nanostructure and carbon capsulation. Furthermore, full-cell evaluations indicate that the unique Si/C nanostructures have a great potential in the next-generation lithium-ion battery. These findings not only greatly improve the electrochemical performances of Si anode, but also shine some light on designing the unique nanomaterials for various energy devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Classical molecular dynamics simulations for non-equilibrium correlated plasmas
NASA Astrophysics Data System (ADS)
Ferri, S.; Calisti, A.; Talin, B.
2017-03-01
A classical molecular dynamics model was recently extended to simulate neutral multi-component plasmas where various charge states of the same atom and electrons coexist. It is used to investigate the plasma effects on the ion charge and on the ionization potential in dense plasmas. Different simulated statistical properties will show that the concept of isolated particles is lost in such correlated plasmas. The charge equilibration is discussed for a carbon plasma at solid density and investigation on the charge distribution and on the ionization potential depression (IPD) for aluminum plasmas is discussed with reference to existing experiments.
Complexity and Intermittent Turbulence in Space Plasmas
NASA Technical Reports Server (NTRS)
Chang, Tom; Tam, Sunny W. Y.; Wu, Cheng-Chin
2004-01-01
Sporadic and localized interactions of coherent structures arising from plasma resonances can be the origin of "complexity" of the coexistence of non- propagating spatiotemporal fluctuations and propagating modes in space plasmas. Numerical simulation results are presented to demonstrate the intermittent character of the non-propagating fluctuations. The technique of the dynamic renormalization-group is introduced and applied to the study of scale invariance of such type of multiscale fluctuations. We also demonstrate that the particle interactions with the intermittent turbulence can lead to the efficient energization of the plasma populations. An example related to the ion acceleration processes in the auroral zone is provided.
Gök, Kevser; Cengiz, Gizem; Erol, Kemal; Ozgocmen, Salih
2017-01-01
Familial Mediterranean fever (FMF) is the most common hereditary auto-inflammatory (periodic fever) syndrome, and usually successfully treated with colchicine. However, nearly 5-10% of FMF cases are resistant or intolerant to colchicine and treatment options are highly restricted in these cases. Biologics including anakinra, canakinumab, rilonacept, etanercept, infliximab, interferon-alpha, and tocilizumab are shown to have efficacy to control FMF attacks. Tofacitinib, a Janus kinase (JAK) inhibitor, is an orally administered non-biologic disease modifying anti-rheumatic drug for the treatment of rheumatoid arthritis (RA). Herein we report a female patient with coexisting RA and colchicine resistant FMF whose FMF attacks and disease activity were completely controlled after treatment with tofacitinib, a small-molecule JAK3 inhibitor.
Adaptive genetic complementarity in mate choice coexists with selection for elaborate sexual traits
Oh, Kevin P; Badyaev, Alexander V
2006-01-01
Choice of genetically unrelated mates is widely documented, yet it is not known how self-referential mate choice can co-occur with commonly observed directional selection on sexual displays. Across 10 breeding seasons in a wild bird population, we found strong fitness benefits of matings between genetically unrelated partners and show that self-referential choice of genetically unrelated mates alternates with sexual selection on elaborate plumage. Seasonal cycles of diminishing variation in ornamentation, caused by early pairing of the most elaborated males, and influx of increasingly genetically unrelated available mates caused by female-biased dispersal, lead to temporal fluctuations in the target of mate choice and enabled coexistence of directional selection for ornament elaboration with adaptive pairing of genetically unrelated partners. PMID:16822752
Bem, C
1996-01-01
Tuberculous lymphadenitis is common in Central Africa, where diagnosis by histological examination of a biopsied node is often delayed. In the present study, the naked eye appearance of the cut surface of 306 consecutive biopsied lymph nodes was compared with the histological diagnosis. One hundred and eight-eight nodes showed tuberculosis on histology (including two with coexisting second pathology). One hundred and forty-eight (79%) cases of tuberculous lymphadenitis (including both with coexisting second pathology) showed noncaseating tuberculomata or caseation visible on naked eye examination. Such signs were not seen in other nodes. Other signs were seen in another 18 (10%) tuberculous nodes. It is concluded that naked eye examination of nodes provides useful information for the diagnosis of tuberculous lymphadenitis, pending confirmation by histology.
Ion beam production and study of radioactive isotopes with the laser ion source at ISOLDE
NASA Astrophysics Data System (ADS)
Fedosseev, Valentin; Chrysalidis, Katerina; Day Goodacre, Thomas; Marsh, Bruce; Rothe, Sebastian; Seiffert, Christoph; Wendt, Klaus
2017-08-01
At ISOLDE the majority of radioactive ion beams are produced using the resonance ionization laser ion source (RILIS). This ion source is based on resonant excitation of atomic transitions by wavelength tunable laser radiation. Since its installation at the ISOLDE facility in 1994, the RILIS laser setup has been developed into a versatile remotely operated laser system comprising state-of-the-art solid state and dye lasers capable of generating multiple high quality laser beams at any wavelength in the range of 210-950 nm. A continuous programme of atomic ionization scheme development at CERN and at other laboratories has gradually increased the number of RILIS-ionized elements. At present, isotopes of 40 different elements have been selectively laser-ionized by the ISOLDE RILIS. Studies related to the optimization of the laser-atom interaction environment have yielded new laser ion source types: the laser ion source and trap and the versatile arc discharge and laser ion source. Depending on the specific experimental requirements for beam purity or versatility to switch between different ionization mechanisms, these may offer a favourable alternative to the standard hot metal cavity configuration. In addition to its main purpose of ion beam production, the RILIS is used for laser spectroscopy of radioisotopes. In an ongoing experimental campaign the isotope shifts and hyperfine structure of long isotopic chains have been measured by the extremely sensitive in-source laser spectroscopy method. The studies performed in the lead region were focused on nuclear deformation and shape coexistence effects around the closed proton shell Z = 82. The paper describes the functional principles of the RILIS, the current status of the laser system and demonstrated capabilities for the production of different ion beams including the high-resolution studies of short-lived isotopes and other applications of RILIS lasers for ISOLDE experiments. This article belongs to the Focus on Exotic Beams at ISOLDE: A Laboratory Portrait special issue.
Why do cryptic species tend not to co-occur? A case study on two cryptic pairs of butterflies.
Vodă, Raluca; Dapporto, Leonardo; Dincă, Vlad; Vila, Roger
2015-01-01
As cryptic diversity is being discovered, mostly thanks to advances in molecular techniques, it is becoming evident that many of these taxa display parapatric distributions in mainland and that they rarely coexist on islands. Genetic landscapes, haplotype networks and ecological niche modeling analyses were performed for two pairs of non-sister cryptic butterfly species, Aricia agestis-A. cramera and Polyommatus icarus-P. celina (Lycaenidae), to specifically assess non-coexistence on western Mediterranean islands, and to test potential causes producing such chequered distribution patterns. We show that the morphologically and ecologically equivalent pairs of species do not coexist on any of the studied islands, although nearly all islands are colonized by one of them. According to our models, the cryptic pairs displayed marked climatic preferences and 'precipitation during the driest quarter' was recovered as the most important climatic determinant. However, neither dispersal capacity, nor climatic or ecological factors fully explain the observed distributions across particular sea straits, and the existence of species interactions resulting in mutual exclusion is suggested as a necessary hypothesis. Given that the studied species are habitat generalists, feeding on virtually unlimited resources, we propose that reproductive interference, together with climatic preferences, sustain density-dependent mechanisms like "founder takes all" and impede coexistence on islands. Chequered distributions among cryptic taxa, both sister and non-sister, are common in butterflies, suggesting that the phenomenon revealed here could be important in determining biodiversity patterns.
Why Do Cryptic Species Tend Not to Co-Occur? A Case Study on Two Cryptic Pairs of Butterflies
Vodă, Raluca; Dapporto, Leonardo; Dincă, Vlad; Vila, Roger
2015-01-01
As cryptic diversity is being discovered, mostly thanks to advances in molecular techniques, it is becoming evident that many of these taxa display parapatric distributions in mainland and that they rarely coexist on islands. Genetic landscapes, haplotype networks and ecological niche modeling analyses were performed for two pairs of non-sister cryptic butterfly species, Aricia agestis-A. cramera and Polyommatus icarus—P. celina (Lycaenidae), to specifically assess non-coexistence on western Mediterranean islands, and to test potential causes producing such chequered distribution patterns. We show that the morphologically and ecologically equivalent pairs of species do not coexist on any of the studied islands, although nearly all islands are colonized by one of them. According to our models, the cryptic pairs displayed marked climatic preferences and ‘precipitation during the driest quarter’ was recovered as the most important climatic determinant. However, neither dispersal capacity, nor climatic or ecological factors fully explain the observed distributions across particular sea straits, and the existence of species interactions resulting in mutual exclusion is suggested as a necessary hypothesis. Given that the studied species are habitat generalists, feeding on virtually unlimited resources, we propose that reproductive interference, together with climatic preferences, sustain density-dependent mechanisms like “founder takes all” and impede coexistence on islands. Chequered distributions among cryptic taxa, both sister and non-sister, are common in butterflies, suggesting that the phenomenon revealed here could be important in determining biodiversity patterns. PMID:25692577
Screening for the coexistence of congenital muscular torticollis and developmental dysplasia of hip.
Kim, Sung Nyun; Shin, Yong Beom; Kim, Wan; Suh, Hwi; Son, Han Kyeong; Cha, Young Sun; Chang, Jae Hyeok; Ko, Hyun-Yoon; Lee, In Sook; Kim, Min Jeong
2011-08-01
To investigate the coexistence rate and related factors of developmental dysplasia of the hip (DDH) and congenital muscular torticollis (CMT), and to determine whether ultrasonography (US) gives good value for screening of DDH in CMT. We prospectively examined 121 infants (73 males and 48 females) diagnosed with CMT to determine the incidence of DDH by US. We also assessed the relationship between neck US findings and DDH occurrence, and investigated the clinical features of CMT related to DDH. 18 patients (14.9%) were diagnosed as having DDH by US. However, most DDH was subclinical and spontaneously resolved. Only 2 patients (1.7%) needed to be treated with a harness. The positive predictive value of clinical examinations for DDH was 52.6% and patients treated by harness were all clinically positive. DDH was more common in the left side (13 left, 4 right, 1 both), but 6 out of 18 DDH (33.3%) cases presented on the contralateral side of CMT. Sex difference was not observed. Breech presentation and oligohydramnios were not related to DDH occurrence. Neck US findings did not correlate with DDH occurrence. The coexistence rate of CMT and DDH was concluded to be 14.9%. If only DDH cases that required treatment were included, the coexistence rate of these two disorders would be lowered to 1.7%. All of these patients showed positive findings in clinical examination. Therefore, hip US should not be recommended routinely for patients with CMT.
Seedling survival and growth of three forest tree species: The role of spatial heterogeneity
Brian Beckage; James S. Clark
2003-01-01
Spatial heterogeneity in microenvironments may provide unique regeneration niches for trees and may promote forest diversity. We examined how heterogeneity in understory cover, mineral nutrients, and moisture and their interactions with canopy gaps contribute to the coexistence of three common, co-occuring tree species. We measured survival and height growth of 1080...
Curriculum Documents and Practice in the NZ Polytechnic Sector: Consensus and Dissensus
ERIC Educational Resources Information Center
Melles, Gavin
2008-01-01
In New Zealand the polytechnic sector embraces a range of post-compulsory education fields. Fields as diverse as nursing, business, social work and English as a Second Language (ESL) may co-exist on polytechnic campuses and are subject to similar curriculum documentation processes. The common competency-based framework and discourse of such…
USDA-ARS?s Scientific Manuscript database
Despite large variation in root traits among species, we have limited understanding of how traits are related to diverse soil resource acquisition strategies. We examined root trait variation among 33 species co-existing in Northeastern US forests that form the two most common mutualisms with mycorr...
Ramirez, Alexies; Gentlesk, Philip J; Peele, Mark E; Eckart, Robert E
2012-07-01
Device therapy is becoming common in those patients with renal insufficiency. Coexisting need for arteriovenous (AV) fistula placement is often contemplated relative to device placement. We describe the excimer laser lead extraction of a malfunctioning chronic atrial pacemaker lead ipsilateral to an AV fistula.
USDA-ARS?s Scientific Manuscript database
Background and aims: Patients with coexisting coronary heart disease (CHD) and type 2 diabetes mellitus (T2DM) are at high risk of cardiovascular recurrence, however, it is not well established whether they exhibit an increased intima-media thickness of both common carotid arteries (IMT-CC). Further...
ERIC Educational Resources Information Center
Masson, Steve; Potvin, Patrice; Riopel, Martin; Foisy, Lorie-Marlène Brault
2014-01-01
Science education studies have revealed that students often have misconceptions about how nature works, but what happens to misconceptions after a conceptual change remains poorly understood. Are misconceptions rejected and replaced by scientific conceptions, or are they still present in students' minds, coexisting with newly acquired…
ERIC Educational Resources Information Center
Sakurai, Ryo; Jacobson, Susan K.
2011-01-01
Co-existing with wildlife and maintaining rural livelihoods are common challenges in remote villages in Japan. The authors assess the effects of the Monkey-Persimmon Environmental Education Program developed to reduce wildlife conflicts and to revitalize a community in Nagano Prefecture. Development of a logic model helped guide interviews with…
Melfa, G; Bernardi, L; Tettamanti, M; Mangano, S
2004-01-01
We report a case of acute renal failure, quickly evolved, in which the coexistence of parenchimal nephropaty and renal mass, have induced not a common diagnostic and therapeutic approach, finalized to optimize the interventional nephrology procedures, with the use of various imaging procedures. It is followed a multidisciplinar therapeutic approach, with the employment of dialysis, steroid therapy and surgical treatment.
Burnt-Out but Engaged: The Co-Existence of Psychological Burnout and Engagement
ERIC Educational Resources Information Center
Timms, Carolyn; Brough, Paula; Graham, Deborah
2012-01-01
Purpose: This research sought to identify groups of school employees who were more similar in their responses to burnout and engagement measures, for the purpose of exploring what was similar in their school experiences. The profiles created in the present research enable a clearer appreciation of what is common to groups of school employees who…
ERIC Educational Resources Information Center
Lee, Jin Sook; Hill-Bonnet, Laura; Raley, Jason
2011-01-01
In settings where speakers of two or more different languages coexist, language brokering, the act of interpreting and translating between culturally and linguistically different speakers, is commonly practiced. Yet the examination of language brokering and its implications in classroom settings have not received much attention in the literature.…
NASA Astrophysics Data System (ADS)
Maneva, Y. G.; Poedts, S.
2017-12-01
Non-thermal kinetic components such as deformed velocity distributions, temperature anisotropies and relative drifts between the multiple ion populations are frequently observed features in the collisionless fast solar wind streams near the Earth whose origin is still to be better understood. Some of the traditional models consider the formation of the temperature anisotropies through the effect of the solar wind expansion, while others assume in situ heating and particle acceleration by local fluctuations, such as plasma waves, or by spacial structures, such as advected or locally generated current sheets. In this study we consider the evolution of initial ion temperature anisotropies and relative drifts in the presence of plasma oscillations, such as ion-cyclotron and kinetic Alfven waves. We perform 2.5D hybrid simulations to study the evolution of observed fast solar wind plasma parcels, including the development of the plasma micro-instabilities, the field-particle correlations and the energy transfer between the multiple ion species. We consider two distinct cases of highly anisotropic and quickly drifting protons which excite ion-cyclotron waves and of moderately anisotropic slower protons, which co-exist with kinetic Alfven waves. The alpha particles for both cases are slightly anisotropic in the beginning and remain anisotropic throughout the simulation time. Both the imposed magnetic fluctuations and the initial differential streaming decrease in time for both cases, while the minor ions are getting heated. Finally we study the effects of the solar wind expansion and discuss its implications for the nonlinear evolution of the system.
Ion sieving in graphene oxide membranes via cationic control of interlayer spacing
NASA Astrophysics Data System (ADS)
Chen, Liang; Shi, Guosheng; Shen, Jie; Peng, Bingquan; Zhang, Bowu; Wang, Yuzhu; Bian, Fenggang; Wang, Jiajun; Li, Deyuan; Qian, Zhe; Xu, Gang; Liu, Gongping; Zeng, Jianrong; Zhang, Lijuan; Yang, Yizhou; Zhou, Guoquan; Wu, Minghong; Jin, Wanqin; Li, Jingye; Fang, Haiping
2017-10-01
Graphene oxide membranes—partially oxidized, stacked sheets of graphene—can provide ultrathin, high-flux and energy-efficient membranes for precise ionic and molecular sieving in aqueous solution. These materials have shown potential in a variety of applications, including water desalination and purification, gas and ion separation, biosensors, proton conductors, lithium-based batteries and super-capacitors. Unlike the pores of carbon nanotube membranes, which have fixed sizes, the pores of graphene oxide membranes—that is, the interlayer spacing between graphene oxide sheets (a sheet is a single flake inside the membrane)—are of variable size. Furthermore, it is difficult to reduce the interlayer spacing sufficiently to exclude small ions and to maintain this spacing against the tendency of graphene oxide membranes to swell when immersed in aqueous solution. These challenges hinder the potential ion filtration applications of graphene oxide membranes. Here we demonstrate cationic control of the interlayer spacing of graphene oxide membranes with ångström precision using K+, Na+, Ca2+, Li+ or Mg2+ ions. Moreover, membrane spacings controlled by one type of cation can efficiently and selectively exclude other cations that have larger hydrated volumes. First-principles calculations and ultraviolet absorption spectroscopy reveal that the location of the most stable cation adsorption is where oxide groups and aromatic rings coexist. Previous density functional theory computations show that other cations (Fe2+, Co2+, Cu2+, Cd2+, Cr2+ and Pb2+) should have a much stronger cation-π interaction with the graphene sheet than Na+ has, suggesting that other ions could be used to produce a wider range of interlayer spacings.
Hsu, Keng-Chang; Lee, Cheng-Fa; Tseng, Wei-Chang; Chao, Yu-Ying; Huang, Yeou-Lih
2014-10-01
In this study we developed an on-line, eco-friendly, and highly selective method using a gold nanoparticle (AuNP)-coated polydimethylsiloxane (PDMS) composite microfluidic (MF) chip coupled to inductively coupled plasma mass spectrometry (ICP-MS) to separate trace Hg(2+) ions from aqueous samples. Because Hg(2+) ions interact with AuNPs to form Hg-Au complexes, we were able to separate Hg(2+) ions from aqueous samples. We prepared the AuNPs-PDMS composite through in situ synthesis using a PDMS cross-linking agent to both reduce and embed AuNPs onto PDMS microchannels so that no additional reductants were required for either AuNP synthesis or the PDMS surface modification (2% HAuCl4, room temperature, 48 h). To optimize the proposed on-line system, we investigated several factors that influenced the separation of Hg(2+) ions in the AuNPs-PDMS/MF, including adsorption pH, adsorption and elution flow rates, microchannel length, and interferences from coexisting ions. Under optimized conditions (pH 6.0; adsorption/elution flow rates: 0.05/0.5 mL min(-1); channel length: 840 mm), we evaluated the accuracy of the system using a standard addition method; the measured values had agreements of ≥ 93.0% with certified values obtained for Hg(2+) ions. The relative standard deviations of the proposed method ranged from 2.24% to 6.21%. The limit of detection for Hg(2+) for the proposed on-line AuNPs-PDMS/MF/ICP-MS analytical method was as low as 0.07 µg L(-1). Copyright © 2014 Elsevier B.V. All rights reserved.
Cronin, Adam L; Loeuille, Nicolas; Monnin, Thibaud
2016-02-05
Offspring investment strategies vary markedly between and within taxa, and much of this variation is thought to stem from the trade-off between offspring size and number. While producing larger offspring can increase their competitive ability, this often comes at a cost to their colonization ability. This competition-colonization trade-off (CCTO) is thought to be an important mechanism supporting coexistence of alternative strategies in a wide range of taxa. However, the relative importance of an alternative and possibly synergistic mechanism-spatial structuring of the environment-remains the topic of some debate. In this study, we explore the influence of these mechanisms on metacommunity structure using an agent-based model built around variable life-history traits. Our model combines explicit resource competition and spatial dynamics, allowing us to tease-apart the influence of, and explore the interaction between, the CCTO and the spatial structure of the environment. We test our model using two reproductive strategies which represent extremes of the CCTO and are common in ants. Our simulations show that colonisers outperform competitors in environments subject to higher temporal and spatial heterogeneity and are favoured when agents mature late and invest heavily in reproduction, whereas competitors dominate in low-disturbance, high resource environments and when maintenance costs are low. Varying life-history parameters has a marked influence on coexistence conditions and yields evolutionary stable strategies for both modes of reproduction. Nonetheless, we show that these strategies can coexist over a wide range of life-history and environmental parameter values, and that coexistence can in most cases be explained by a CCTO. By explicitly considering space, we are also able to demonstrate the importance of the interaction between dispersal and landscape structure. The CCTO permits species employing different reproductive strategies to coexist over a wide range of life-history and environmental parameters, and is likely to be an important factor in structuring ant communities. Our consideration of space highlights the importance of dispersal, which can limit the success of low-dispersers through kin competition, and enhance coexistence conditions for different strategies in spatially structured environments.
Host population structure and treatment frequency maintain balancing selection on drug resistance
Baskerville, Edward B.; Colijn, Caroline; Hanage, William; Fraser, Christophe; Lipsitch, Marc
2017-01-01
It is a truism that antimicrobial drugs select for resistance, but explaining pathogen- and population-specific variation in patterns of resistance remains an open problem. Like other common commensals, Streptococcus pneumoniae has demonstrated persistent coexistence of drug-sensitive and drug-resistant strains. Theoretically, this outcome is unlikely. We modelled the dynamics of competing strains of S. pneumoniae to investigate the impact of transmission dynamics and treatment-induced selective pressures on the probability of stable coexistence. We find that the outcome of competition is extremely sensitive to structure in the host population, although coexistence can arise from age-assortative transmission models with age-varying rates of antibiotic use. Moreover, we find that the selective pressure from antibiotics arises not so much from the rate of antibiotic use per se but from the frequency of treatment: frequent antibiotic therapy disproportionately impacts the fitness of sensitive strains. This same phenomenon explains why serotypes with longer durations of carriage tend to be more resistant. These dynamics may apply to other potentially pathogenic, microbial commensals and highlight how population structure, which is often omitted from models, can have a large impact. PMID:28835542
Invasion waves in the biochemical warfare between living organisms
NASA Astrophysics Data System (ADS)
Carvalho, S. A.; Martins, M. L.
2018-04-01
Microorganisms and plants very commonly release toxic secondary chemical compounds (allelochemicals) that inhibit or kill sensitive strains or individuals from their own or other species. In this work we study a model that describes two species interacting through allelopathic suppression and competing for resources. Employing linear stability analysis, the conditions for coexistence or extinction of species in spatially homogeneous systems were determined. We found that the borders between the regimes of bistability, coexistence, and the extinction of the weaker by the stronger competitor, are altered by allelopathic interactions. In addition, traveling wave solutions for one species invasion were obtained considering the spatially explicit nature of the model. Our findings indicate that the minimum speed of the invasion wavefronts depends primarily on the competition coefficients and the parameters characterizing the species' functional responses to their allelochemicals. As a general rule, the species provided with the most effective chemical weapons dominates the population dynamics. Finally, we found a tristability at the coexistence region due to the combination of allelopathy and patchy population distributions in space. So, our model provides a distinct mechanism, independent of social behaviors, that produces such unexpected tristability impossible in classical competition models involving one-to-one individual interactions.
A spatial scan statistic for multiple clusters.
Li, Xiao-Zhou; Wang, Jin-Feng; Yang, Wei-Zhong; Li, Zhong-Jie; Lai, Sheng-Jie
2011-10-01
Spatial scan statistics are commonly used for geographical disease surveillance and cluster detection. While there are multiple clusters coexisting in the study area, they become difficult to detect because of clusters' shadowing effect to each other. The recently proposed sequential method showed its better power for detecting the second weaker cluster, but did not improve the ability of detecting the first stronger cluster which is more important than the second one. We propose a new extension of the spatial scan statistic which could be used to detect multiple clusters. Through constructing two or more clusters in the alternative hypothesis, our proposed method accounts for other coexisting clusters in the detecting and evaluating process. The performance of the proposed method is compared to the sequential method through an intensive simulation study, in which our proposed method shows better power in terms of both rejecting the null hypothesis and accurately detecting the coexisting clusters. In the real study of hand-foot-mouth disease data in Pingdu city, a true cluster town is successfully detected by our proposed method, which cannot be evaluated to be statistically significant by the standard method due to another cluster's shadowing effect. Copyright © 2011 Elsevier Inc. All rights reserved.
Invasion waves in the biochemical warfare between living organisms.
Carvalho, S A; Martins, M L
2018-04-01
Microorganisms and plants very commonly release toxic secondary chemical compounds (allelochemicals) that inhibit or kill sensitive strains or individuals from their own or other species. In this work we study a model that describes two species interacting through allelopathic suppression and competing for resources. Employing linear stability analysis, the conditions for coexistence or extinction of species in spatially homogeneous systems were determined. We found that the borders between the regimes of bistability, coexistence, and the extinction of the weaker by the stronger competitor, are altered by allelopathic interactions. In addition, traveling wave solutions for one species invasion were obtained considering the spatially explicit nature of the model. Our findings indicate that the minimum speed of the invasion wavefronts depends primarily on the competition coefficients and the parameters characterizing the species' functional responses to their allelochemicals. As a general rule, the species provided with the most effective chemical weapons dominates the population dynamics. Finally, we found a tristability at the coexistence region due to the combination of allelopathy and patchy population distributions in space. So, our model provides a distinct mechanism, independent of social behaviors, that produces such unexpected tristability impossible in classical competition models involving one-to-one individual interactions.
NASA Astrophysics Data System (ADS)
Oliveira, M. P.; Mercena, S. G.; Meneses, C. T.; Jesus, C. B. R.; Pagliuso, P. G.; Duque, J. G. S.
2018-04-01
In this work, we report on X-ray diffraction and magnetization measurements carried out in the low-dimensional hexagonal cobaltites BaxA1-xCoO3-δ (A = Mg or Ca, 0 ⩽ x ⩽ 0.20 and δ = 0 or 0.4). Polycrystalline samples have been synthesized by solid-state reaction. The Rietveld refinements of the X-ray diffraction patterns show clearly a phase coexistence of both BaCoO2.6 and BaCoO3 hexagonal polytype structures (space group: P63/mmc), which is dependent on both the dopant ion and doping level. At low temperatures (T < 50K), the ZFC-FC data recorded at H = 1 kOe for Ca-doped (x < 0.15) and Ba0.80Mg0.20CoO3-δ samples present a broad peak and strong thermal hysteresis. Besides, a second anomaly around room temperature is also observed in susceptibility curves for all samples. Further increasing in the Ca-doping produces a continuous decreasing of magnetization and for the samples with x > 0.10 the low temperature hysteresis is not observed anymore. The field-dependence of ZFC-FC curves taken for the sample grown with x = 0 show a displacement of the peak position into low temperature region. Except for the sample grown with x = 0.20, the MvsH loops taken at T = 2 K show multiple steps in the field region ranging - 15 ⩽ H ⩽ 15 kOe . Finally, the saturation magnetization values are consistent with a low-spin state for the Co2+ or Co4+ ions.
Li, Feng; Du, Ping; Chen, Wei; Zhang, Shusheng
2007-03-07
A new porous sorbent for wastewater treatment of metal ions was synthesized by covalent grafting of molecularly imprinted organic-inorganic hybrid on silica gel. With sucrose and polyethylene glycol 4000 (PEG 4000) being synergic imprinting molecules, covalent surface coating on silica gel was achieved by using polysaccharide-incorporated sol-gel process starting from the functional biopolymer, chitosan and an inorganic epoxy-precursor, gamma-glycidoxypropyltrimethoxysiloxane (GPTMS) at room temperature. The prepared porous sorbent was characterized by using simultaneous thermogravimetry and differential scanning calorimeter (TG/DSC), scanning electron microscopy (SEM), nitrogen adsorption porosimetry measurement and X-ray diffraction (XRD). Copper ion, Cu(2+), was chosen as the model metal ion to evaluate the effectiveness of the new biosorbent in wastewater treatment. The influence of epoxy-siloxane dose, buffer pH and co-existed ions on Cu(2+) adsorption was assessed through batch experiments. The imprinted composite sorbent offered a fast kinetics for the adsorption of Cu(2+). The uptake capacity of the sorbent imprinted by two pore-building components was higher than those imprinted with only a single component. The dynamic adsorption in column underwent a good elimination of Cu(2+) in treating electric plating wastewater. The prepared composite sorbent exhibited high reusability. Easy preparation of the described porous composite sorbent, absence of organic solvents, cost-effectiveness and high stability make this approach attractive in biosorption.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xu, Siyao; Lazarian, A.; Yan, Huirong, E-mail: hryan@pku.edu.cn
We address the problem of the different line widths of coexistent neutrals and ions observed in molecular clouds and explore whether this difference can arise from the effects of magnetohydrodynamic (MHD) turbulence acting on partially ionized gas. Among the three fundamental modes of MHD turbulence, we find that fast and slow modes do not contribute to line width differences. We focus on the Alfvénic component, and consider the damping of Alfvén modes by taking into account both neutral-ion collisions and neutral viscosity. We confirm that the line width difference can be explained by the differential damping of the Alfvénic turbulencemore » in ions and the hydrodynamic turbulence in neutrals, and find it strongly depends on the properties of MHD turbulence. We consider various regimes of turbulence corresponding to different media magnetizations and turbulent drivings. In the case of super-Alfvénic turbulence, when the damping scale of Alfvénic turbulence is below the Alfvénic scale l{sub A}, the line width difference does not depend on magnetic field strength. In other turbulence regimes, however, the dependence is present and evaluation of magnetic field from the observed line width difference is possible.« less
NASA Astrophysics Data System (ADS)
Mamun, A. A.
2018-02-01
A general (but realistic) self-gravitating degenerate quantum plasma system (SG-DQPS) containing inertialess degenerate electron species, inertial degenerate light, and heavy ion/nucleus species is considered to examine the possibility for the existence of degenerate pressure driven self-gravito-acoustic (DPD-SGA) solitary waves (SWs) formed in such a SG-DQPS. The pseudo-potential approach, which is valid for the arbitrary amplitude DPD-SGA SWs, is employed. It is found that depending on the value of the number density of heavy ion/nucleus species, the SG-DQPS under consideration supports the existence of positive or the coexistence of positive and negative DPD-SGA SWs. The basic features (polarity, amplitude, and width) of both positive and negative DPD-SGA SWs are found to be significantly modified by the dynamics of heavy ion/nucleus species. The theoretical investigation presented here is so general that it can be applied not only in astrophysical SG-DQPSs (such as white dwarf and neutron star SG-DQPSs), but also in laboratory SG-DQPSs (viz., solid density and laser-produced SG-DQPSs) to identify the salient features of the DPD-SGA SWs formed in them.
Nanofriction in Cavity Quantum Electrodynamics
NASA Astrophysics Data System (ADS)
Fogarty, T.; Cormick, C.; Landa, H.; Stojanović, Vladimir M.; Demler, E.; Morigi, Giovanna
2015-12-01
The dynamics of cold trapped ions in a high-finesse resonator results from the interplay between the long-range Coulomb repulsion and the cavity-induced interactions. The latter are due to multiple scatterings of laser photons inside the cavity and become relevant when the laser pump is sufficiently strong to overcome photon decay. We study the stationary states of ions coupled with a mode of a standing-wave cavity as a function of the cavity and laser parameters, when the typical length scales of the two self-organizing processes, Coulomb crystallization and photon-mediated interactions, are incommensurate. The dynamics are frustrated and in specific limiting cases can be cast in terms of the Frenkel-Kontorova model, which reproduces features of friction in one dimension. We numerically recover the sliding and pinned phases. For strong cavity nonlinearities, they are in general separated by bistable regions where superlubric and stick-slip dynamics coexist. The cavity, moreover, acts as a thermal reservoir and can cool the chain vibrations to temperatures controlled by the cavity parameters and by the ions' phase. These features are imprinted in the radiation emitted by the cavity, which is readily measurable in state-of-the-art setups of cavity quantum electrodynamics.
Warnke, Stephan; Baldauf, Carsten; Bowers, Michael T; Pagel, Kevin; von Helden, Gert
2014-07-23
Ultraviolet photodissociation (UVPD) of gas-phase proteins has attracted increased attention in recent years. This growing interest is largely based on the fact that, in contrast to slow heating techniques such as collision induced dissociation (CID), the cleavage propensity after absorption of UV light is distributed over the entire protein sequence, which can lead to a very high sequence coverage as required in typical top-down proteomics applications. However, in the gas phase, proteins can adopt a multitude of distinct and sometimes coexisting conformations, and it is not clear how this three-dimensional structure affects the UVPD fragmentation behavior. Using ion mobility-UVPD-mass spectrometry in conjunction with molecular dynamics simulations, we provide the first experimental evidence that UVPD is sensitive to the higher order structure of gas-phase proteins. Distinct UVPD spectra were obtained for different extended conformations of 11(+) ubiquitin ions. Assignment of the fragments showed that the majority of differences arise from cis/trans isomerization of one particular proline peptide bond. Seen from a broader perspective, these data highlight the potential of UVPD to be used for the structural analysis of proteins in the gas phase.
Nilchi, A; Saberi, R; Garmarodi, S Rasouli; Bagheri, A
2012-02-01
Hydrous manganese dioxide-polyacrylonitrile (MnO(2)-PAN) was chemically synthesized and evaluated, as an organic-inorganic composite material, for the removal of radio-contaminant cesium-137 from aqueous solutions. The physico-chemical characterization was carried out by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), CHN elemental analysis, scanning electron microscopy (SEM), nitrogen adsorption-desorption studies and thermogravimetry-differential scanning calorimetry (TGA-DSC). Batch experiments were carried out as a function of contact time, interference of the coexisting ions and initial pH of adsorptive solution applying a radiotracer technique. The effect of temperature on the distribution coefficient of cesium has been utilized in order to evaluate the changes in the standard thermodynamic parameters. The results indicated that Cs(+) ions could be efficiently removed using MnO(2)-PAN composite in the pH range of 4-9 from aqueous solutions and the uptake of cesium is affected to varying degrees by the presence of some diverse co-ions. The equilibrium isotherms have been determined and the sorption data were successfully modeled using Freundlich model. Copyright © 2011 Elsevier Ltd. All rights reserved.
Moderation of neoclassical impurity accumulation in high temperature plasmas of helical devices
NASA Astrophysics Data System (ADS)
Velasco, J. L.; Calvo, I.; Satake, S.; Alonso, A.; Nunami, M.; Yokoyama, M.; Sato, M.; Estrada, T.; Fontdecaba, J. M.; Liniers, M.; McCarthy, K. J.; Medina, F.; Van Milligen, B. Ph; Ochando, M.; Parra, F.; Sugama, H.; Zhezhera, A.; The LHD Experimental Team; The TJ-II Team
2017-01-01
Achieving impurity and helium ash control is a crucial issue in the path towards fusion-grade magnetic confinement devices, and this is particularly the case of helical reactors, whose low-collisionality ion-root operation scenarios usually display a negative radial electric field which is expected to cause inwards impurity pinch. In this work we discuss, based on experimental measurements and standard predictions of neoclassical theory, how plasmas of very low ion collisionality, similar to those observed in the impurity hole of the large helical device (Yoshinuma et al and The LHD Experimental Group 2009 Nucl. Fusion 49 062002, Ida et al and The LHD Experimental Group 2009 Phys. Plasmas 16 056111 and Yokoyama et al and LHD Experimental Group 2002 Nucl. Fusion 42 143), can be an exception to this general rule, and how a negative radial electric field can coexist with an outward impurity flux. This interpretation is supported by comparison with documented discharges available in the International Stellarator-Heliotron Profile Database, and it can be extrapolated to show that achievement of high ion temperature in the core of helical devices is not fundamentally incompatible with low core impurity content.
Tang, Shimei; Zhou, Jian; Zou, Hua-Hong; Liu, Xing; Zhang, Li
2018-02-05
A series of lanthanide selenidogermanates, (H 2 peha)[Ln 2 (μ-OH) 2 (tepa) 2 Cl 2 ]{[Ln 2 (μ-OH) 2 (tepa) 2 Cl] 2 (μ-Ge 2 Se 6 )}[Ge 2 Se 6 ]Cl 2 [Ln = Y (1a) and Er (1b); peha = pentaethylenexamine, tepa = tetraethylenepentamine], [Sm 2 (μ-OH) 2 (tepa) 2 (μ-Ge 2 Se 6 )] n (2), [Ho 2 (μ-OH) 2 (tepa) 2 (μ-Ge 2 Se 6 )] n (3), and [Ce 4 (tepa) 4 (μ-GeSe 4 )(μ-GeSe 5 )(μ-Ge 2 Se 6 )] n (4), were made under solvothermal conditions. Compounds 1a and 1b contain a protonated H 2 peha 2+ ion, the complex cation [Ln 2 (μ-OH) 2 (tepa) 2 Cl 2 ] 2+ , a [Ge 2 Se 6 ] 4- anion, free Cl - ions, and a {[Ln 2 (μ-OH) 2 (tepa) 2 Cl] 2 (μ-Ge 2 Se 6 )} 2+ cation constructed by two unsaturated [Ln 2 (μ-OH) 2 (tepa) 2 Cl] 3+ groups connecting via the trans terminal Se atoms of the [Ge 2 Se 6 ] 4- anion, which provides the first example of an organic decorated lanthanide selenidogermanate cation. Both compounds 2 and 3 contain one-dimensional chains [Ln 2 (μ-OH) 2 (tepa) 2 (μ-Ge 2 Se 6 )] n constructed by a combination of unsaturated complex cations [Ln 2 (μ-OH) 2 (tepa) 2 ] 4+ and [Ge 2 Se 6 ] 4- anions, but their stacking patterns of neutral chains are different. Compound 4 contains one-dimensional chain [Ce 4 (tepa) 4 (μ-GeSe 4 )(μ-GeSe 5 )(μ-Ge 2 Se 6 )] n , where three different selenidogermanate units acting as bridging ligands connect unsaturated [Ce(tepa)] 3+ ions. Compound 4 represents the first example of the coexistence of three different selenidogermanate anions in the same architecture. Their optical properties are studied, and the magnetic properties of compounds 1b and 2-4 are also investigated.
Li, Xiaomei; Xu, Feng; Liang, Dandan; Liang, Shaoshan; Zhu, Xiaodong; Zhang, Mingchao; Huang, Xianghua; Liu, Zhihong; Zeng, Caihong
2018-02-01
Light chain proximal tubulopathy (LCPT) associated with plasma cell dyscrasias is a rare abnormality, especially cases involving multiple cell types. The aim of this study is to explore the characteristics and outcomes of these diseases. We comprehensively evaluated the clinical-pathological data, treatment, and outcomes of 6 LCPT patients with involvement of multiple cell types. In 3 cases, we found that the inclusions largely existed in tubular cells, while in 2 cases they coexisted in podocytes and tubular cells, and in 1 case they coexisted in histiocytes and tubular cells. The stain features and appearances of inclusions were specific and varied. Five patients displayed κ-light chains with crystal formation, while 1 patient displayed a λ subtype with increased lysosomes instead of crystals. Six patients presented with proteinuria, 4 with renal insufficiency, and 4 with complete or partial Fanconi syndrome. Our findings indicate that tubular cells are the most common location of cytoplasmic inclusions. Cases with κ-light chain storage are more common than λ, and the formation of crystals may be associated with the subtype of light chains. Immunoelectron microscopy could be used to increase sensitivity for the detection and location of monoclonal light chains. Therefore, these patients have some common clinical features with varied pathologic characteristics and prognoses but the same subtype of light chains. .
Coexistence of Fe(II)- and Mn(II)-oxidizing bacteria govern the formation of deep sea umber deposits
NASA Astrophysics Data System (ADS)
Peng, Xiaotong; Ta, Kaiwen; Chen, Shun; Zhang, Lijuan; Xu, Hengchao
2015-11-01
The genesis of umber deposits has remained controversial for several decades. Recently, microbial Fe(II) oxidation associated with low-temperature diffuse venting has been identified as a key process for the formation of umber deposits, but the exact biogeochemical mechanisms involved to the precipitation of Mn oxides in umber deposits still remain unknown. Here, we used nano secondary ion mass spectrometer, synchrotron-based X-ray absorption spectroscopy, electron microscopy, and molecular techniques to demonstrate the coexistence of two types of metal-oxidizing bacteria within deep-sea hydrothermal umber deposits at the South Mid-Atlantic Ridge, where we found unique spheroids composed of biogenic Fe oxyhydroxides and Mn oxides in the deposits. Our data show that Fe oxyhydroxides and Mn oxides are metabolic by-products of lithotrophic Fe(II)-oxidizing bacteria and heterotrophic Mn(II)-oxidizing bacteria, respectively. The hydrothermal vents fuel lithotrophic microorganisms, which constitute a trophic base that might support the activities of heterogenic Mn(II)-oxidizing bacteria. The biological origin of umber deposits shed light on the importance of geomicrobiological interaction in triggering the formation of metalliferous deposits, with important implications for the generation of submarine Mn deposits and crusts.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mukerjee, S.; Thurston, T.R.; Jisrawi, N.M.
The authors describe synchrotron based X-ray diffraction techniques and issues related to in situ studies of intercalation processes in battery electrodes. They then demonstrate the utility of this technique, through a study of two batches of Li{sub x}Mn{sub 2}O{sub 4} cathode materials. The structural evolution of these spinel materials was monitored in situ during the initial charge of these electrodes in actual battery cells. Significant differences were observed in the two batches, particularly in the intercalation range of x = 0.45 to 0.20. The first-order structural transitions in this region indicated coexistence of two cubic phases in the batch 2more » material, whereas the batch 1 material showed suppressed two-phase coexistence. Batch 2 cells also indicated structural evolution in the low-potential region below 3.0 V in contrast to the batch 1 material. Differences in structural evolution between batches of Li{sub x}Mn{sub 2}O{sub 4} could have important ramifications in their cycle life and stability characteristics.« less
Parrón Collar, Dámaso; Pazos Guerra, Mario; Rodriguez, Paula; Gotera, Carolina; Mahíllo-Fernández, Ignacio; Peces-Barba, Germán; Seijo, Luis M
2017-01-01
Many patients with COPD are underdiagnosed, including patients with coexisting lung cancer. We conducted a retrospective study of COPD prevalence and outcomes among all patients diagnosed with lung cancer at our institution during a 2-year period. Patients with known COPD (group A) were compared with those who received a diagnosis of COPD at the time of their oncologic workup (group B). A total of 306 patients were diagnosed with lung cancer during the study period, including 87 with COPD (28.6%). Sixty percent of patients with coexisting lung cancer and COPD were unaware of their obstructive airways disease prior to the lung cancer diagnosis. Patients in group A were older (74+9 vs 69+9 years; P =0.03), had more severe obstruction (% of predicted forced expiratory volume in one second [FEV 1 %] 55+17 vs 71+13; P =0.04), more emphysema (91% vs 65%; P =0.02), and worse diffusing capacity of the lungs for carbon monoxide 59+19% vs 72+22%; P =0.01) than patients in group B, but the latter had more advanced lung cancer (27.3% vs 13.8% stage IV disease; P =0.01) and consumed more outpatient resources ( P =0.03). Overall mortality was similar (56% vs 58%). However, stage-adjusted mortality showed a trend toward greater mortality in group B patients (1.87 [0.91-3.85]; P =0.087). COPD infradiagnosis is common in patients with coexisting lung cancer and is associated with more advanced cancer stage, greater outpatient resource consumption, and may be associated with greater stage-adjusted mortality.
O’Toole, Orna; Lennon, Vanda A.; Ahlskog, J. Eric; Matsumoto, Joseph Y.; Pittock, Sean J.; Bower, James; Fealey, Robert; Lachance, Daniel H.
2013-01-01
Objectives: To determine the characteristics of adult-onset autoimmune chorea, and compare paraneoplastic and idiopathic subgroups. Methods: Thirty-six adults with autoimmune chorea were identified at Mayo Clinic (Rochester, MN) from 1997 to 2012. Medical record and laboratory data were recorded. Nonparaneoplastic (n = 22) and paraneoplastic cases (n = 14) were compared. Results: Women accounted for 21 patients (58%). Median age at symptom onset was 67 years (range 18–87 years). We estimated the incidence for Olmsted County was 1.5 per million person-years. Symptom onset was subacute in all. Chorea was focal (20 patients) or generalized (16 patients). Although chorea predominated, other neurologic disorders frequently coexisted (29 patients); abnormal eye movements were uncommon (4 patients). No patient had NMDA receptor antibody or any immunoglobulin (Ig)G yielding a detectable immunofluorescence binding pattern restricted to basal ganglia. Two had synaptic IgG antibodies novel to the context of chorea (GAD65, 1; CASPR2, 1). In the paraneoplastic group, 14 patients had evidence of cancer. Of 13 with a histopathologically confirmed neoplasm, small-cell carcinoma and adenocarcinoma were most common; 6 patients had a cancer-predictive paraneoplastic autoantibody, with CRMP-5–IgG and ANNA-1 being most common. In the idiopathic group, 19 of the 22 patients had a coexisting autoimmune disorder (most frequently systemic lupus erythematosus and antiphospholipid syndrome); autoantibodies were detected in 21 patients, most frequently lupus and phospholipid specificities (19 patients). The paraneoplastic group was older (p = 0.001), more frequently male (p = 0.006), had more frequent weight loss (p = 0.02), and frequently had peripheral neuropathy (p = 0.008). Conclusions: Autoimmune chorea is a rare disorder with rapid onset. Male sex, older age, severe chorea, coexisting peripheral neuropathy, and weight loss increase the likelihood of cancer. PMID:23427325
The coexistence of natural and supernatural explanations across cultures and development.
Legare, Cristine H; Evans, E Margaret; Rosengren, Karl S; Harris, Paul L
2012-01-01
Although often conceptualized in contradictory terms, the common assumption that natural and supernatural explanations are incompatible is psychologically inaccurate. Instead, there is considerable evidence that the same individuals use both natural and supernatural explanations to interpret the very same events and that there are multiple ways in which both kinds of explanations coexist in individual minds. Converging developmental research from diverse cultural contexts in 3 areas of biological thought (i.e., the origin of species, illness, and death) is reviewed to support this claim. Contrary to traditional accounts of cognitive development, new evidence indicates that supernatural explanations often increase rather than decrease with age and supports the proposal that reasoning about supernatural phenomena is an integral and enduring aspect of human cognition. © 2012 The Authors. Child Development © 2012 Society for Research in Child Development, Inc.
Coexistence of Mayer-Rokitansky-Küster-Hauser Syndrome and Turner Syndrome: A Case Report.
Białka, Agnieszka; Gawlik, Aneta; Drosdzol-Cop, Agnieszka; Wilk, Krzysztof; Małecka-Tendera, Ewa; Skrzypulec-Plinta, Violetta
2016-04-01
Turner syndrome is a common chromosomal disorder, with an incidence of 1 in 2000 live-born female infants. Mayer-Rokitansky-Küster-Hauser syndrome (MRKH) affects 1 in 4500 female births and, rarely, it might be associated with gonadal dysgenesis. A 17-year-old girl was referred to our clinic with short stature and primary amenorrhea. The patient was diagnosed with Turner syndrome and underwent estrogen therapy. At the age of 24 years, just after the patient's sexual initiation, the first complete gynecological examination was performed. A blind-ending vagina was revealed and the patient was diagnosed with MRKH. Early diagnosis of coexistence of MRKH and Turner syndrome, although very difficult, might prevent patients from developing serious complications. Copyright © 2016 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Singh, R.N.
One hundred and fifty patients with coronary artery disease (CAD), 14 (9.3%) of whom had coexisting peripheral vascular disease, underwent bilateral internal mammary arteriography to study the incidence and extent of atherosclerosis in these vessels. Significant atherosclerosis of the internal mammary arteries (IMAs) was present in three patients (2%), of whom one had coexisting peripheral vascular disease. Lesions in the IMAs were found either proximally, close to the origin or distally, around the terminal bifurcation. Six of the 14 patients with peripheral vascular disease (4% of total subjects) had significant atherosclerosis of the brachiocephalic arteries. Atherosclerotic involvement of the IMAmore » is very unusual and rarely interferes with the use of these vessels for coronary bypass. More common, however, is atherosclerosis of the subclavian arteries, a contraindication for IMA grafting if the lesion is proximal to the IMA origin.« less
ERIC Educational Resources Information Center
Jones, Beth A.; Smith, Heather Haynes; Hensley-Maloney, Lauren; Gansle, Kristin A.
2015-01-01
When visual impairments (VI) and learning disabilities (LD) coexist, it is common for one (i.e., typically LD) to go unidentified. Some school districts may be reluctant to identify students with both VI and LD, potentially causing students to miss out on much-needed services. Child study teams can find support to address this dual diagnosis using…
Seeds of Peace: Toward a Common Narrative
ERIC Educational Resources Information Center
van Woerkom, Marieke
2004-01-01
The Seeds of Peace program began in August 1993 when forty-eight Egyptian, Israeli, and Arabic boys met at a summer camp in Maine for a two-week coexistence program that gave them the opportunity not only to meet their "enemies" for the first time, but to live with them in cabins, share meals, and participate in typical summer camp activities. In…
Uebel-von Sandersleben, Henrik; Albrecht, Björn; Rothenberger, Aribert; Fillmer-Heise, Anke; Roessner, Veit; Sergeant, Joseph; Tannock, Rosemary; Banaschewski, Tobias
2017-01-01
Attention Deficit / Hyperactivity Disorder (ADHD) and Chronic Tic Disorder (CTD) are two common and frequently co-existing disorders, probably following an additive model. But this is not yet clear for the basic sensory function of colour processing sensitive to dopaminergic functioning in the retina and higher cognitive functions like attention and interference control. The latter two reflect important aspects for psychoeducation and behavioural treatment approaches. Colour discrimination using the Farnsworth-Munsell 100-hue Test, sustained attention during the Frankfurt Attention Inventory (FAIR), and interference liability during Colour- and Counting-Stroop-Tests were assessed to further clarify the cognitive profile of the co-existence of ADHD and CTD. Altogether 69 children were classified into four groups: ADHD (N = 14), CTD (N = 20), ADHD+CTD (N = 20) and healthy Controls (N = 15) and compared in cognitive functioning in a 2×2-factorial statistical model. Difficulties with colour discrimination were associated with both ADHD and CTD factors following an additive model, but in ADHD these difficulties tended to be more pronounced on the blue-yellow axis. Attention problems were characteristic for ADHD but not CTD. Interference load was significant in both Colour- and Counting-Stroop-Tests and unrelated to colour discrimination. Compared to Controls, interference load in the Colour-Stroop was higher in pure ADHD and in pure CTD, but not in ADHD+CTD, following a sub-additive model. In contrast, interference load in the Counting-Stroop did not reveal ADHD or CTD effects. The co-existence of ADHD and CTD is characterized by additive as well as sub-additive performance impairments, suggesting that their co-existence may show simple additive characteristics of both disorders or a more complex interaction, depending on demand. The equivocal findings on interference control may indicate limited validity of the Stroop-Paradigm for clinical assessments.
Kneitel, Jamie M.
2012-01-01
Trade-offs among species’ ecological interactions is a pervasive explanation for species coexistence. The traits associated with trade-offs are typically measured to mechanistically explain species coexistence at a single spatial scale. However, species potentially interact at multiple scales and this may be reflected in the traits among coexisting species. I quantified species’ ecological traits associated with the trade-offs expected at both local (competitive ability and predator tolerance) and regional (competitive ability and colonization rate) community scales. The most common species (four protozoa and a rotifer) from the middle trophic level of a pitcher plant (Sarracenia purpurea) inquiline community were used to link species traits to previously observed patterns of species diversity and abundance. Traits associated with trade-offs (competitive ability, predator tolerance, and colonization rate) and other ecological traits (size, growth rate, and carrying capacity) were measured for each of the focal species. Traits were correlated with one another with a negative relationship indicative of a trade-off. Protozoan and rotifer species exhibited a negative relationship between competitive ability and predator tolerance, indicative of coexistence at the local community scale. There was no relationship between competitive ability and colonization rate. Size, growth rate, and carrying capacity were correlated with each other and the trade-off traits: Size was related to both competitive ability and predator tolerance, but growth rate and carrying capacity were correlated with predator tolerance. When partial correlations were conducted controlling for size, growth rate and carrying capacity, the trade-offs largely disappeared. These results imply that body size is the trait that provides the basis for ecological interactions and trade-offs. Altogether, this study showed that the examination of species’ traits in the context of coexistence at different scales can contribute to our understanding of the mechanisms underlying community structure. PMID:22844526
Trait-fitness relationships determine how trade-off shapes affect species coexistence.
Ehrlich, Elias; Becks, Lutz; Gaedke, Ursula
2017-12-01
Trade-offs between functional traits are ubiquitous in nature and can promote species coexistence depending on their shape. Classic theory predicts that convex trade-offs facilitate coexistence of specialized species with extreme trait values (extreme species) while concave trade-offs promote species with intermediate trait values (intermediate species). We show here that this prediction becomes insufficient when the traits translate non-linearly into fitness which frequently occurs in nature, e.g., an increasing length of spines reduces grazing losses only up to a certain threshold resulting in a saturating or sigmoid trait-fitness function. We present a novel, general approach to evaluate the effect of different trade-off shapes on species coexistence. We compare the trade-off curve to the invasion boundary of an intermediate species invading the two extreme species. At this boundary, the invasion fitness is zero. Thus, it separates trait combinations where invasion is or is not possible. The invasion boundary is calculated based on measurable trait-fitness relationships. If at least one of these relationships is not linear, the invasion boundary becomes non-linear, implying that convex and concave trade-offs not necessarily lead to different coexistence patterns. Therefore, we suggest a new ecological classification of trade-offs into extreme-favoring and intermediate-favoring which differs from a purely mathematical description of their shape. We apply our approach to a well-established model of an empirical predator-prey system with competing prey types facing a trade-off between edibility and half-saturation constant for nutrient uptake. We show that the survival of the intermediate prey depends on the convexity of the trade-off. Overall, our approach provides a general tool to make a priori predictions on the outcome of competition among species facing a common trade-off in dependence of the shape of the trade-off and the shape of the trait-fitness relationships. © 2017 by the Ecological Society of America.
Rothenberger, Aribert; Fillmer-Heise, Anke; Roessner, Veit; Sergeant, Joseph; Tannock, Rosemary; Banaschewski, Tobias
2017-01-01
Objective Attention Deficit / Hyperactivity Disorder (ADHD) and Chronic Tic Disorder (CTD) are two common and frequently co-existing disorders, probably following an additive model. But this is not yet clear for the basic sensory function of colour processing sensitive to dopaminergic functioning in the retina and higher cognitive functions like attention and interference control. The latter two reflect important aspects for psychoeducation and behavioural treatment approaches. Methods Colour discrimination using the Farnsworth-Munsell 100-hue Test, sustained attention during the Frankfurt Attention Inventory (FAIR), and interference liability during Colour- and Counting-Stroop-Tests were assessed to further clarify the cognitive profile of the co-existence of ADHD and CTD. Altogether 69 children were classified into four groups: ADHD (N = 14), CTD (N = 20), ADHD+CTD (N = 20) and healthy Controls (N = 15) and compared in cognitive functioning in a 2×2-factorial statistical model. Results Difficulties with colour discrimination were associated with both ADHD and CTD factors following an additive model, but in ADHD these difficulties tended to be more pronounced on the blue-yellow axis. Attention problems were characteristic for ADHD but not CTD. Interference load was significant in both Colour- and Counting-Stroop-Tests and unrelated to colour discrimination. Compared to Controls, interference load in the Colour-Stroop was higher in pure ADHD and in pure CTD, but not in ADHD+CTD, following a sub-additive model. In contrast, interference load in the Counting-Stroop did not reveal ADHD or CTD effects. Conclusion The co-existence of ADHD and CTD is characterized by additive as well as sub-additive performance impairments, suggesting that their co-existence may show simple additive characteristics of both disorders or a more complex interaction, depending on demand. The equivocal findings on interference control may indicate limited validity of the Stroop-Paradigm for clinical assessments. PMID:28594866
Magneto-structural correlation in Co0.8Cu0.2Cr2O4 cubic spinel
NASA Astrophysics Data System (ADS)
Kumar, Ram; Rayaprol, S.; Siruguri, V.; Xiao, Y.; Ji, W.; Pal, D.
2018-05-01
Neutron and X-ray diffraction, magnetic susceptibility, and specific heat measurements have been used to investigate the magneto-structural phase transitions in 20% Cu substituted multiferroic CoCr2O4 spinel. The Jahn-Teller active Cu2+ ion in the tetrahedral A-site of the spinel configuration induces the Jahn-Teller distortion slightly above the Néel temperature. In this compound, we observe a Jahn-Teller distortion of the crystal structure at 90 K. It was further observed that the high temperature cubic (Fd 3 ‾ m) structure coexists with the low temperature orthorhombic (Fddd) structure till the lowest temperature of measurement.
Bio-derived hierarchically macro-meso-micro porous carbon anode for lithium/sodium ion batteries
NASA Astrophysics Data System (ADS)
Elizabeth, Indu; Singh, Bhanu Pratap; Trikha, Sunil; Gopukumar, Sukumaran
2016-10-01
Nitrogen doped hierarchically porous carbon derived from prawn shells have been efficiently synthesized through a simple, economically viable and environmentally benign approach. The prawn shell derived carbon (PSC) has high inherent nitrogen content (5.3%) and possesses a unique porous structure with the co-existence of macro, meso and micropores which can afford facile storage and transport channels for both Li and Na ions. PSC is well characterized using X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Transmission electron Microscopy (TEM), High resolution TEM (HR-TEM) and X-ray photoelectron spectroscopy (XPS). Electron Paramagnetic Resonance (EPR) and Solid state-Nuclear Magnetic Resonance (NMR) studies have been conducted on pristine PSC and Li/Na interacted PSC. PSC as anode for Lithium ion batteries (LIBs) delivers superior electrochemical reversible specific capacity (740 mAh g-1 at 0.1 Ag-1 current density for 150 cycles) and high rate capability. When used as anode material for Sodium ion batteries (SIBs), PSC exhibits excellent reversible specific capacity of 325 mAh g-1 at 0.1 Ag-1 for 200 cycles and rate capability of 107 mAh g-1 at 2 Ag-1. Furthermore, this study demonstrates the employment of natural waste material as a potential anode for both LIB and SIB, which will definitively make a strike in the energy storage field.
Chen, Qiang; Wu, Xiaojie; Wang, Dingzhong; Tang, Wei; Li, Na; Liu, Feng
2011-06-21
A quartz crystal microbalance with dissipation monitoring (QCM-D) sensor was developed for highly sensitive and specific detection of mercury(II) ions (Hg(2+)) with a tunable dynamic range, using oligonucleotide-functionalized gold nanoparticles (GNPs) for both frequency and dissipation amplification. The fabrication of the sensor employed a 'sandwich-type' strategy, and formation of T-Hg(2+)-T structures in linker DNA reduced the hybridization of the GNPs-tagged DNA on the gold electrode, which could be used as the molecular switch for Hg(2+) sensing. This QCM-D mercury sensor showed a linear response of 10-200 nM, with detection limits of 4 nM and 7 nM for frequency and dissipation measurements, respectively. Moreover, the dynamic range of the sensor could be tuned by simply altering the concentration of linker DNA without designing new sensors in the cases where detection of Hg(2+) at different levels is required. This sensor afforded excellent selectivity toward Hg(2+) compared with other potential coexisting metal ions. The feasibility of the sensor was demonstrated by analyzing Hg(2+)-spiked tap- and lake-water samples with satisfactory recoveries. The proposed approach extended the application of the QCM-D system in metal ions sensing, and could be adopted for the detection of other analytes when complemented with the use of functional DNA structures.
Adsorption and removal of arsenic(V) from drinking water by aluminum-loaded Shirasu-zeolite.
Xu, Yan-hua; Nakajima, Tsunenori; Ohki, Akira
2002-06-10
The demand for effective and inexpensive adsorbents is to increase in response to the widespread recognition of the deleterious health effects of arsenic exposure through drinking water. A novel adsorbent, aluminum-loaded Shirasu-zeolite P1 (Al-SZP1), was prepared and employed for the adsorption and removal of arsenic(V) (As(V)) ion from aqueous system. The process of adsorption follows first-order kinetics and the adsorption behavior is fitted with a Freundlich isotherm. The adsorption of As(V) is slightly dependent on the initial pH over a wide range (3-10). Al-SZP1 was found with a high As(V) adsorption ability, equivalent to that of activated alumina, and seems to be especially suitable for removal of As(V) in low concentration. The addition of arsenite, chloride, nitrate, sulfate, chromate, and acetate ions hardly affected the As(V) adsorption, whereas the coexisting phosphate greatly interfered with the adsorption. The adsorption mechanism is supposed as a ligand-exchange process between As(V) ions and the hydroxide groups present on the surface of Al-SZP1. The adsorbed As(V) ions were desorbed effectively by a 40 mM NaOH solution. Continuous operation was demonstrated in a column packed with Al-SZP1. The feasibility of this technique to practical utilization was also assessed by adsorption/desorption multiple cycles with in situ desorption/regeneration operation.
Banerjee, Malay; Takeuchi, Yasuhiro
2017-01-07
Maturation time delay for the predators is introduced in prey-predator models to implicitly model the stage-structure of predators. Most of the prey-predator models with maturation delay are known to exhibit destabilization of coexistence steady-state. Discrete time delay induced destabilization is a common finding, however, this is due to the introduction of time delay with lack of ecological justification. The main objective of the present work is to show the stabilizing role of maturation delay for a class of delayed prey-predator model. To be specific, we consider prey-predator models with strong and weak Allee effects in prey growth and Michaelis-Menten type functional response. We provide ecological justification for the introduction of maturation delay parameter in predator's growth equation. We obtain the conditions for stable and oscillatory coexistence of prey and their specialist predator in case of strong as well as weak Allee effect for non-delayed and delayed models. Apart from the analytical results for the models under consideration, we perform extensive numerical simulations to construct the relevant bifurcation diagrams. Our analytical and supportive numerical findings reveal that delay is not always a destabilizing factor rather the stable coexistence in the presence of time delay depends upon the formulation of the delayed model. The biological implications of the current investigation are provided in the conclusion section. We also explain the validity of obtained results for other types of prey-predator models with a specialist predator. Copyright © 2016 Elsevier Ltd. All rights reserved.
Disturbance facilitates the coexistence of antagonistic ecosystem engineers in California estuaries.
Castorani, Max C N; Hovel, Kevin A; Williams, Susan L; Baskett, Marissa L
2014-08-01
Ecological theory predicts that interactions between antagonistic ecosystem engineers can lead to local competitive exclusion, but disturbance can facilitate broader coexistence. However, few empirical studies have tested the potential for disturbance to mediate competition between engineers. We examined the capacity for disturbance and habitat modification to explain the disjunct distributions of two benthic ecosystem engineers, eelgrass Zostera marina and the burrowing ghost shrimp Neotrypaea californiensis, in two California estuaries. Sediment sampling in eelgrass and ghost shrimp patches revealed that ghost shrimp change benthic biogeochemistry over small scales (centimeters) but not patch scales (meters to tens of meters), suggesting a limited capacity for sediment modification to explain species distributions. To determine the relative competitive abilities of engineers, we conducted reciprocal transplantations of ghost shrimp and eelgrass. Local ghost shrimp densities declined rapidly following the addition of eelgrass, and transplanted eelgrass expanded laterally into the surrounding ghost shrimp-dominated areas. When transplanted into eelgrass patches, ghost shrimp failed to persist. Ghost shrimp were also displaced from plots with structural mimics of eelgrass rhizomes and roots, suggesting that autogenic habitat modification by eelgrass is an important mechanism determining ghost shrimp distributions. However, ghost shrimp were able to rapidly colonize experimental disturbances to eelgrass patch edges, which are common in shallow estuaries. We conclude that coexistence in this system is maintained by spatiotemporally asynchronous disturbances and a competition-colonization trade-off: eelgrass is a competitively superior ecosystem engineer, but benthic disturbances permit the coexistence of ghost shrimp at the landscape scale by modulating the availability of space.
Risk correlates for physical-mental multimorbidities in South Africa: a cross-sectional study.
Petersen, I; Rathod, S; Kathree, T; Selohilwe, O; Bhana, A
2017-12-04
The aim of this study was to identify the risk correlates for coexisting common mental disorders (CMDs) in the chronic care population in South Africa, with the view to identifying particularly vulnerable patient populations. The sample comprised 2549 chronic care patients enrolled in the baseline and endline rounds of a facility detection survey conducted by the Programme for Improving Mental Health Care in three large facilities in the Dr Kenneth Kaunda district in the North West province of South Africa. Participants were screened for depression using the Patient Health Questionnaire (PHQ9) and for alcohol misuse using the Alcohol Use Disorders Identification Test (AUDIT). Data were analysed according to the number of morbidities, disorder type (physical or mental) and demographic variables. Multimorbidity was defined as the presence of two or more disorders (physical and/or mental). Just over one-third of the sample reported two or more physical conditions. Women were more at risk of being depressed than were men, with men more at risk of alcohol misuse. Those who were employed were at lower risk of having coexisting CMDs, while being younger, HIV positive, and food deprived were all found to be associated with higher risk for having coexisting CMDs. In the face of the large treatment gap for CMDs in South Africa, and the role that coexisting CMDs can play in exacerbating the burden of chronic physical diseases, mental health screening and treatment interventions should target HIV-positive, younger patients living in circumstances where there is household food insecurity.
Ip, Philip Pun-Ching
2018-02-14
Benign proliferations that mimic malignancies are commonly encountered during the course of assessment of small and fragmented endometrial samples. Although benign, endometrial epithelial metaplasias often coexist with premalignant or malignant lesions causing diagnostic confusion. The difficulty with mucinous metaplasia lies in its distinction from atypical mucinous glandular proliferations and mucinous carcinomas, which are associated with significant interobserver variability. Papillary proliferation of the endometrium is commonly associated with hormonal drugs and endometrial polyps and is characterised by papillae with fibrovascular cores covered by epithelial cells without cytologic atypia. They are classified into simple or complex papillary proliferations depending on the architectural complexity and extent of proliferation. Complex papillary proliferations are associated with a high risk of concurrent or subsequent hyperplasia with atypia/carcinoma. Papillary proliferations may have coexisting epithelial metaplasias and, most commonly, mucinous metaplasia and syncytial papillary change. Those with striking mucinous metaplasia overlap morphologically with papillary mucinous metaplasia. The latter has been proposed as a precursor of endometrial mucinous carcinoma. Misinterpreting the Arias-Stella reaction as a malignant or premalignant lesion is more likely to occur if the pathologist is unaware that the patient is pregnant or on hormonal drugs. Endometrial hyperplasia with secretory changes may occasionally be difficult to distinguish from the torturous and crowded glands of a late secretory endometrium. Endometrial polyps may have abnormal features that can be misinterpreted as endometrial hyperplasia or Mullerian adenosarcoma. Awareness of these benign endometrial proliferations and their common association with hormonal medication or altered endogenous hormonal levels will help prevent the over-diagnosis of premalignant and malignant lesions.
The Reduction in the Rate of Hydrolysis of Diphenylbromomethane by the Common-Ion Effect
ERIC Educational Resources Information Center
Cameron-Holford, Richard; Ratneswaren, Tarini; Hughes, D. E. Peter
2010-01-01
Kinetic study on the hydrolysis of diphenylbromomethane does not provide clear-cut evidence for the mechanism of the reaction. The reduction in the rate of the reaction by added bromide ions suggested that the reaction took place by a S[subscript N]1 mechanism. A more detailed study of this common-ion effect, using conductivity to measure the rate…
Pattern formation in the iodate-sulfite-thiosulfate reaction-diffusion system.
Liu, Haimiao; Pojman, John A; Zhao, Yuemin; Pan, Changwei; Zheng, Juhua; Yuan, Ling; Horváth, Attila K; Gao, Qingyu
2012-01-07
Sodium polyacrylate-induced pH pattern formation and starch-induced iodine pattern formation were investigated in the iodate-sulfite-thiosulfate (IST) reaction in a one-side fed disc gel reactor (OSFR). As binding agents of the autocatalyst of hydrogen ions or iodide ions, different content of sodium polyacrylate or starch has induced various types of pattern formation. We observed pH pulses, striped patterns, mixed spots and stripes, and hexagonal spots upon increasing the content of sodium polyacrylate and observed iodine pulses, branched patterns, and labyrinthine patterns upon increasing the starch content in the system. Coexistence of a pH front and an iodine front was also studied in a batch IST reaction-diffusion system. Both pH and iodine front instabilities were observed in the presence of sodium polyacrylate, i.e., cellular fronts and transient Turing structures resulting from the decrease in diffusion coefficients of activators. The mechanism of multiple feedback may explain the different patterns in the IST reaction-diffusion system.
NASA Astrophysics Data System (ADS)
Peng, Qian; Hou, Faju; Jiang, Chongqiu
2006-09-01
A new spectrofluorimetric method was developed for determination of trace amount of Coenzyme II (NADP). Using europium ion-doxycycline (DC) as a fluorescent probe, in the buffer solution of pH 8.44, NADP can remarkably enhance the fluorescence intensity of the Eu 3+-DC complex at λ = 612 nm and the enhanced fluorescence intensity is in proportion to the concentration of NADP. Optimum conditions for the determination of NADP were also investigated. The dynamic range for the determination of NADP is 3.3 × 10 -7 to 6.1 × 10 -6 mol l -1 with detection limit of 6.8 × 10 -8 mol l -1. This method is simple, practical and relatively free interference from coexisting substances and can be successfully applied to determination of NADP in synthetic water samples and in serum samples. Moreover, the enhancement mechanisms of the fluorescence intensity in the Eu 3+-DC system and the Eu 3+-DC-NADP system have been also discussed.
NASA Astrophysics Data System (ADS)
Gunaydin-Sen, Ozge
2005-03-01
Natural abundance ^15N CPMAS NMR has been used to investigate the paraelectric-antiferroelectric phase transition of NH4H2AsO4 (ADA) (TN˜216K) and of NH4H2PO4 (ADP) (148K), with a focus on the role of the NH4^+ ion. Isotropic chemical shift of ^15N for ADA exhibits an almost linear temperature dependence to within TN±1K, and then changes discontinuously, followed by another almost linear dependence. The spectra of the paraelectric and antiferroelectric phases coexist around the TN. The sharp anomaly around TN implies that the NH4^+ ions undergo a displacive transition, whereas the protons in the O-HO bonds undergo an order-disorder transition. The ^15N data thus support a mixed order-disorder-displacive mechanism for this transition. The ^15N data on ADP exhibit somewhat different behavior. ^31P CPMAS measurements will also be presented and discussed in terms of the above model.
Temperature-Dependent Electric Field Poling Effects in CH3NH3PbI3 Optoelectronic Devices.
Zhang, Chuang; Sun, Dali; Liu, Xiaojie; Sheng, Chuan-Xiang; Vardeny, Zeev Valy
2017-04-06
Organo-lead halide perovskites show excellent optoelectronic properties; however, the unexpected inconsistency in forward-backward I-V characteristics remains a problem for fabricating solar panels. Here we have investigated the reasons behind this "hysteresis" by following the changes in photocurrent and photoluminescence under electric field poling in transverse CH 3 NH 3 PbI 3 -based devices from 300 to 10 K. We found that the hysteresis disappears at cryogenic temperatures, indicating the "freeze-out" of the ionic diffusion contribution. When the same device is cooled under continuous poling, the built-in electric field from ion accumulation brings significant photovoltaic effect even at 10 K. From the change of photoluminescence upon polling, we found a second dipole-related mechanism which enhances radiative recombination upon the alignment of the organic cations. The ionic origin of hysteresis was also verified by applying a magnetic field to affect the ion diffusion. These findings reveal the coexistence of ionic and dipole-related mechanisms for the hysteresis in hybrid perovskites.
Fukahori, S; Fujiwara, T; Funamizu, N; Matsukawa, K; Ito, R
2013-01-01
The adsorptive removal of seven sulfonamide antibiotics using the high-silica zeolite HSZ-385 from distilled water, synthetic urine and real porcine urine was investigated. The pH greatly affected the adsorption efficiency, and the amounts of all sulfonamide antibiotics adsorbed on HSZ-385 decreased at alkaline conditions compared with that at neutral conditions. During storage, the pH and ammonium-ion concentration increased with urea hydrolysis for porcine urine. We clarified that the adsorption efficiency of sulfonamides in synthetic urine was equivalent to that in distilled water, suggesting that adsorption behavior was not affected by coexistent ions. HSZ-385 could adsorb sulfonamide antibiotics in real porcine urine even though the non-purgeable organic carbon concentration of porcine urine was 4-7 g/L and was two orders of magnitude higher than those of sulfonamides (10 mg/L each). Moreover, the adsorption of sulfonamides reached equilibrium within 15 min, suggesting that HSZ-385 is a promising adsorbent for removing sulfonamides from porcine urine.
Chen, Jinyuan; Qian, Yi; Li, Herong; Cheng, Yanhong; Zhao, Meirong
2015-08-01
Nano-TiO2 is a widely applied nanoparticle (NPs) and co-exists with other pollutants such as heavy metals in aquatic environments. However, minimal knowledge is available concerning the ecological risk of these mixtures. Our study reported that at no toxic effect concentrations of TiO2 nanoparticles (5 mg/L), the toxicity of Cu ions to the algae Microcystis aeruginosa was significantly attenuated by TiO2 nanoparticles. Specifically, the concentration of photosynthetic pigments (i.e., concentration of Chla) increased 37% when comparing only Cu ions treated and the nano-TiO2-Cu co-incubation. The levels of phycocyanin (PC), allophycocyanin (APC), phycoerythrin (PE), and phycobiliprotein (PBPs) were also recovered at levels ranging from 23 to 35% after 72 h. For oxidative indexes, the decreased activities of the superoxide dismutase (SOD), peroxidase (POD) content, and malondialdehyde (MDA) with the existence of nano-TiO2 displayed a lower level compared to Cu ions treatment only at 24 and 48 h. This toxicity attenuation can be confirmed by subcellular structures because the impairment to cellular membranes and organelles reduced with the presence of nano-TiO2. The potential mechanisms of the antagonism between the nano-TiO2 and Cu ions can be partially attributed to the sorption of copper onto TiO2 nanoparticles, which fitted the Freundlich isotherm (coefficient = 0.967). The decreased bioavailability of Cu ions protected algae cells from being attacked by free Cu ions. Given the abundance of released nanoparticles and unique physicochemical property of nanoparticles, our results elucidated the ecosafety of nanoparticles and co-substrates in aquatic systems.
Wang, Yi-Min; Zhou, Dong-Mei; Yuan, Xu-Yin; Zhang, Xiao-Hui; Li, Yi
2018-05-01
Responses of wheat (Triticum aestivum L.) seedling roots to the mixtures of copper (Cu), cadmium (Cd) and humic acids (HA) were investigated using the solution culture experiments, focusing on the interaction patterns between multiple metals and their influences on root proton release. A concentration-addition multiplication (CA) model was introduced into the modeling analysis. In comparison with metal ion activities in bulk-phase solutions, the incorporation of ion activities at the root cell membrane surfaces (CMs) (denoted as {Cu 2+ } 0 and {Cd 2+ } 0 ) into the CA model could significantly improve their correlation with RRE (relative root elongation) from 0.819 to 0.927. Modeling analysis indicated that the co-existence of {Cu 2+ } 0 significantly enhanced the rhizotoxicity of {Cd 2+ } 0 , while no significant effect of {Cd 2+ } 0 on the {Cu 2+ } 0 rhizotoxicity. 10 mg/L HA stimulated the root elongation even under metal stress. Although high concentration of metal ions inhibited the root proton release rate (ΔH + ), both the low concentration of metal ions and HA treatments increased the values of ΔH + . In HA-Cu-Cd mixtures, actions of metal ions on ΔH + values were varied intricately among treatments but well modeled by the CA model. We concluded from the CA models that the electrostatic effect is vitally important for explaining the effect of {Cu 2+ } 0 on the rhizotoxicity of {Cd 2+ } 0 , while it plays no unique role in understanding the influence of {Cd 2+ } 0 on the rhizotoxicity of {Cu 2+ } 0. Thus our study provide a novel way for modeling multiple metals behaviors in the environment and understanding the mechanisms of ion interactions. Copyright © 2018 Elsevier Ltd. All rights reserved.
Collectivity in the light radon nuclei measured directly via Coulomb excitation
NASA Astrophysics Data System (ADS)
Gaffney, L. P.; Robinson, A. P.; Jenkins, D. G.; Andreyev, A. N.; Bender, M.; Blazhev, A.; Bree, N.; Bruyneel, B.; Butler, P. A.; Cocolios, T. E.; Davinson, T.; Deacon, A. N.; De Witte, H.; DiJulio, D.; Diriken, J.; Ekström, A.; Fransen, Ch.; Freeman, S. J.; Geibel, K.; Grahn, T.; Hadinia, B.; Hass, M.; Heenen, P.-H.; Hess, H.; Huyse, M.; Jakobsson, U.; Kesteloot, N.; Konki, J.; Kröll, Th.; Kumar, V.; Ivanov, O.; Martin-Haugh, S.; Mücher, D.; Orlandi, R.; Pakarinen, J.; Petts, A.; Peura, P.; Rahkila, P.; Reiter, P.; Scheck, M.; Seidlitz, M.; Singh, K.; Smith, J. F.; Van de Walle, J.; Van Duppen, P.; Voulot, D.; Wadsworth, R.; Warr, N.; Wenander, F.; Wimmer, K.; Wrzosek-Lipska, K.; Zielińska, M.
2015-06-01
Background: Shape coexistence in heavy nuclei poses a strong challenge to state-of-the-art nuclear models, where several competing shape minima are found close to the ground state. A classic region for investigating this phenomenon is in the region around Z =82 and the neutron midshell at N =104 . Purpose: Evidence for shape coexistence has been inferred from α -decay measurements, laser spectroscopy, and in-beam measurements. While the latter allow the pattern of excited states and rotational band structures to be mapped out, a detailed understanding of shape coexistence can only come from measurements of electromagnetic matrix elements. Method: Secondary, radioactive ion beams of 202Rn and 204Rn were studied by means of low-energy Coulomb excitation at the REX-ISOLDE in CERN. Results: The electric-quadrupole (E 2 ) matrix element connecting the ground state and first excited 21+ state was extracted for both 202Rn and 204Rn, corresponding to B (E 2 ;21+→01+) =29-8+8 and 43-12+17 W.u., respectively. Additionally, E 2 matrix elements connecting the 21+ state with the 41+ and 22+ states were determined in 202Rn. No excited 0+ states were observed in the current data set, possibly owing to a limited population of second-order processes at the currently available beam energies. Conclusions: The results are discussed in terms of collectivity and the deformation of both nuclei studied is deduced to be weak, as expected from the low-lying level-energy schemes. Comparisons are also made to state-of-the-art beyond-mean-field model calculations and the magnitude of the transitional quadrupole moments are well reproduced.
Haldiman, Tracy; Kim, Chae; Cohen, Yvonne; Chen, Wei; Blevins, Janis; Qing, Liuting; Cohen, Mark L.; Langeveld, Jan; Telling, Glenn C.; Kong, Qingzhong; Safar, Jiri G.
2013-01-01
The unique phenotypic characteristics of mammalian prions are thought to be encoded in the conformation of pathogenic prion proteins (PrPSc). The molecular mechanism responsible for the adaptation, mutation, and evolution of prions observed in cloned cells and upon crossing the species barrier remains unsolved. Using biophysical techniques and conformation-dependent immunoassays in tandem, we isolated two distinct populations of PrPSc particles with different conformational stabilities and aggregate sizes, which frequently co-exist in the most common human prion disease, sporadic Creutzfeldt-Jakob disease. The protein misfolding cyclic amplification replicates each of the PrPSc particle types independently and leads to the competitive selection of those with lower initial conformational stability. In serial propagation with a nonglycosylated mutant PrPC substrate, the dominant PrPSc conformers are subject to further evolution by natural selection of the subpopulation with the highest replication rate due to its lowest stability. Cumulatively, the data show that sporadic Creutzfeldt-Jakob disease PrPSc is not a single conformational entity but a dynamic collection of two distinct populations of particles. This implies the co-existence of different prions, whose adaptation and evolution are governed by the selection of progressively less stable, faster replicating PrPSc conformers. PMID:23974118
A case of desmoid tumor co-existing with recurrent squamous cell carcinoma in the larynx.
Shinohara, Shogo; Suehiro, Atsushi; Kikuchi, Masahiro; Harada, Hiroyuki; Kishimoto, Ippei; Imai, Yukihiro
2017-06-01
Extra-abdominal desmoid tumor, also known as aggressive fibromatosis, has aggressive behavior with local infiltration and tendency for recurrence. Though head and neck is reported to be one of the most common sites, a desmoid tumor in the larynx is extremely rare. A 67-year-old male visited our hospital with prolonged hoarseness and received laryngo-microsurgery with the diagnosis of laryngeal polyp. After the operation, he eventually developed a laryngeal squamous cell carcinoma with papilloma, confirmed by second laryngo-microsurgery and received radiation therapy. After the third laryngo-microsurgery to remove residual papilloma, white irregular mass appeared on the right vocal cord and grew rapidly beneath the glottis, causing dyspnea. After 2 additional laryngo-microsurgeries, he was diagnosed having the dermoid tumor co-existing with recurrent squamous cell carcinoma. He underwent near-total laryngectomy and is currently alive without disease, speaking using a vocal shunt. Only five cases of the desmoid tumors arising in the adult larynx have been reported in the English literature. In this case, repeated surgery and radiation were suspected as the causes. Also, the present report is the first to describe desmoid tumor co-existing with recurrent squamous cell carcinoma in the larynx. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Spatiotemporal Co-existence of Female Thyroid and Breast Cancers in Hangzhou, China
NASA Astrophysics Data System (ADS)
Fei, Xufeng; Christakos, George; Lou, Zhaohan; Ren, Yanjun; Liu, Qingmin; Wu, Jiaping
2016-06-01
Thyroid and breast cancers (TC, BC) are common female malignant tumors worldwide. Studies suggest that TC patients have a higher BC risk, and vice versa. However, it has not been investigated quantitatively if there is an association between the space-time TC and BC incidence distributions at the population level. This work aims to answer this question. 5358 TC and 8784 BC (female) cases were diagnosed in Hangzhou (China, 2008-2012). Pearson and Spearman rank correlation coefficients of the TC and BC incidences were high, and their patterns were geographically similar. The spatiotemporal co-existence of TC and BC distributions was investigated using the integrative disease predictability (IDP) criterion: if TC-BC association is part of the disease mapping knowledge bases, it should yield improved space-time incidence predictions. Improved TC (BC) incidence predictions were generated when integrating both TC and BC data than when using only TC (BC) data. IDP consistently demonstrated the spatiotemporal co-existence of TC and BC distributions throughout Hangzhou (2008-2012), which means that when the population experiences high incidences of one kind of cancer attention should be paid to the other kind of cancer too. The strength of TC-BC association was measured by the IDP coefficients and incidence prediction accuracy.
Spatiotemporal Co-existence of Female Thyroid and Breast Cancers in Hangzhou, China
Fei, Xufeng; Christakos, George; Lou, Zhaohan; Ren, Yanjun; Liu, Qingmin; Wu, Jiaping
2016-01-01
Thyroid and breast cancers (TC, BC) are common female malignant tumors worldwide. Studies suggest that TC patients have a higher BC risk, and vice versa. However, it has not been investigated quantitatively if there is an association between the space-time TC and BC incidence distributions at the population level. This work aims to answer this question. 5358 TC and 8784 BC (female) cases were diagnosed in Hangzhou (China, 2008–2012). Pearson and Spearman rank correlation coefficients of the TC and BC incidences were high, and their patterns were geographically similar. The spatiotemporal co-existence of TC and BC distributions was investigated using the integrative disease predictability (IDP) criterion: if TC-BC association is part of the disease mapping knowledge bases, it should yield improved space-time incidence predictions. Improved TC (BC) incidence predictions were generated when integrating both TC and BC data than when using only TC (BC) data. IDP consistently demonstrated the spatiotemporal co-existence of TC and BC distributions throughout Hangzhou (2008–2012), which means that when the population experiences high incidences of one kind of cancer attention should be paid to the other kind of cancer too. The strength of TC-BC association was measured by the IDP coefficients and incidence prediction accuracy. PMID:27341638
Abiotic vs. biotic influences on habitat selection of coexisting species: Climate change impacts?
Martin, T.E.
2001-01-01
Species are commonly segregated along gradients of microclimate and vegetation. I explore the question of whether segregation is the result of microhabitat partitioning (biotic effects) or choice of differing microclimates (abiotic effects). I explored this question for four ground-nesting bird species that are segregated along a microclimate and vegetation gradient in Arizona. Birds shifted position of their nests on the microhabitat and microclimate gradient in response to changing precipitation over nine years. Similarly, annual bird abundance varied with precipitation across 12 yr. Those shifts in abundance and nesting microhabitat with changing precipitation demonstrate the importance of abiotic influences on bird distributions and habitat choice. However, nest-site shifts and microhabitat use also appear to be influenced by interactions among coexisting species. Moreover, shifts in habitat use by all species caused nest predation (i.e., biotic) costs that increased with increasing distance along the microclimate gradient. These results indicate that abiotic and biotic costs can strongly interact to influence microhabitat choice and abundances of coexisting species. Global climate change impacts have been considered largely in terms of simple distributional shifts, but these results indicate that shifts can also increase biotic costs when species move into habitat types for which they are poorly adapted or that create new biotic interactions.
Coexistence of aspergilloma and pulmonary hydatid cyst in an immunocompetent individual.
Aala, F; Badali, H; Hashemi Fesharaki, S; Boroumand, M; Sotoudeh Anvari, M; Davari, H; Agha Kuchak Afshari, S; Khodavaisy, S
2017-09-01
Echinococcosis is a zoonotic disease caused by Echinococcus granulosus sensu lato. The liver and lungs are the most commonly sites of infections, but involvements of other organs were also observed. Recently, the coinfection of pulmonary hydatid cyst with aspergilloma has been reported in the literature. Herein, we report a successful treatment of coinfection of cystic echinoccosis with aspergilloma due to Aspergillus flavus in a 34-year-old female. In vitro antifungal susceptibility tests revealed that the MIC values for antifungals employed in this case were posaconazole (0.031μg/ml), itraconazole (0.125μg/ml), voriconazole (0.25μg/ml), and amphotericin B (1μg/ml). The minimum effective concentration for caspofungin was 0.008μg/ml. This coexistence of active pulmonary echinococcosis and aspergillosis is being reported because of its rarity and clinical importance for its management. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
Xu, Xinxin; Guo, Yinshi; Li, Qiuying; Yang, Ling; Kang, Jianqiang
2018-06-01
We observed a rare case of invasive mucinous adenocarcinoma (IMA) with a lepidic-predominant pattern accompanied by pulmonary tuberculosis. An 85-year-old man with repeated cough and sputum was admitted to Xinhua Hospital. T-SPOT test result was 212 pg/ml (reference value of negative is < 14 pg/ml), Mycobacterium tuberculosis culture was positive, and tuberculin skin test (PPD) was negative (skin induration < 5 mm). The patient was treated with several courses of antibiotics and anti-tuberculosis treatments. Repeated chest CT scans showed disease progression. Bronchoscopy yielded negative results. PET-CT scans showed negative results. A percutaneous lung biopsy revealed mucin-secreting cells lining the alveolar walls. IMA with a lepidic-predominant pattern was diagnosed after invasiveness was found after experimental treatments. Simultaneous occurrence of pulmonary tuberculosis and lung cancer are common; however, the present case of IMA having a lepidic-predominant pattern and coexisting with active tuberculosis has not been reported yet.
Evolutionary history and distance dependence control survival of dipterocarp seedlings.
Bagchi, Robert; Press, Malcolm C; Scholes, Julie D
2010-01-01
One important hypothesis to explain tree-species coexistence in tropical forests suggests that increased attack by natural enemies near conspecific trees gives locally rare species a competitive advantage. Host ranges of natural enemies generally encompass several closely related plant taxa suggesting that seedlings should also do poorly around adults of closely related species. We investigated the effects of adult Parashorea malaanonan on seedling survival in a Bornean rain forest. Survival of P. malaanonan seedlings was highest at intermediate distances from parent trees while heterospecific seedlings were unaffected by distance. Leaf herbivores did not drive this relationship. Survival of seedlings was lowest for P. malaanonan, and increased with phylogenetic dissimilarity from this species, suggesting that survival of close relatives of common species is reduced. This study suggests that distance dependence contributes to species coexistence and highlights the need for further investigation into the role of shared plant enemies in community dynamics.
Biomarkers in Sleep Apnea and Heart Failure.
Zhao, Ying Y; Mehra, Reena
2017-08-01
Sleep-disordered breathing (SDB) is highly prevalent in heart failure (HF) and may confer significant stress to the cardiovascular system and increases the risk for future cardiovascular events. The present review will provide updates on the current understanding of the relationship of SDB and common HF biomarkers and the effect of positive airway pressure therapy on these biomarkers, with particular emphasis in patients with coexisting SDB and HF. Prior studies have examined the relationship between HF biomarkers and SDB, and the effect of SDB treatment on these biomarkers, with less data available in the context of coexisting SDB and HF. Overall, however, the association of SDB and circulating biomarkers has been inconsistent. Further research is needed to elucidate the relationship between biomarkers and SDB in HF, to evaluate the clinical utility of biomarkers over standard methods in large, prospective studies and also to assess the impact of treatment of SDB on these biomarkers in HF via interventional studies.
[Coexistence of autoimmune polyglandular syndrome type 3 with diabetes insipidus].
Krysiak, Robert; Okopień, Bogusław
2015-01-01
Autoimmune polyglandular syndromes are conditions characterized by the combination of two or more organ-specific disorders. The underestimation oftheir real frequency probable results from physicians' inadequate knowledge of these clinical entities and sometimes their atypical clinical presentation. Because they comprise a wide spectrum of autoimmune disorders, autoimmune polyglandular syndromes are divided into four types, among which type-3 is the most common one. In this article, we report the case of a young female, initially diagnosed with diabetes mellitus who several years later developed full-blown autoimmune polyglandular syndrome type 3 consisting of autoimmune thyroid disorder and latent autoimmune diabetes in adults.The discussed case suggests that in selected patients diabetes insipidus may coexist with autoimmune endocrinopathies and nonendocrine autoimmunopathies, as well as that in some patients idiopathic diabetes insipidus may be secondary to lymphocytic infiltration and destruction of the hypothalamic supraoptic and paraventricular nuclei and/or the supraoptic-hypophyseal tract
Chimera States in Continuous Media: Existence and Distinctness
NASA Astrophysics Data System (ADS)
Nicolaou, Zachary G.; Riecke, Hermann; Motter, Adilson E.
2017-12-01
The defining property of chimera states is the coexistence of coherent and incoherent domains in systems that are structurally and spatially homogeneous. The recent realization that such states might be common in oscillator networks raises the question of whether an analogous phenomenon can occur in continuous media. Here, we show that chimera states can exist in continuous systems even when the coupling is strictly local, as in many fluid and pattern forming media. Using the complex Ginzburg-Landau equation as a model system, we characterize chimera states consisting of a coherent domain of a frozen spiral structure and an incoherent domain of amplitude turbulence. We show that in this case, in contrast with discrete network systems, fluctuations in the local coupling field play a crucial role in limiting the coherent regions. We suggest these findings shed light on new possible forms of coexisting order and disorder in fluid systems.
Bassereau, Maud; Chaintreau, Alain; Duperrex, Stéphanie; Joulain, Daniel; Leijs, Hans; Loesing, Gerd; Owen, Neil; Sherlock, Alan; Schippa, Christine; Thorel, Pierre-Jean; Vey, Matthias
2007-01-10
The performances of the GC-MS determination of suspected allergens in fragrance concentrates have been investigated. The limit of quantification was experimentally determined (10 mg/L), and the variability was investigated for three different data treatment strategies: (1) two columns and three quantification ions; (2) two columns and one quantification ion; and (3) one column and three quantification ions. The first strategy best minimizes the risk of determination bias due to coelutions. This risk was evaluated by calculating the probability of coeluting a suspected allergen with perfume constituents exhibiting ions in common. For hydroxycitronellal, when using a two-column strategy, this may statistically occur more than once every 36 analyses for one ion or once every 144 analyses for three ions in common.
Kander, M; Pasławska, U; Staszczyk, M; Cepiel, A; Pasławski, R; Mazur, G; Noszczyk-Nowak, A
2015-01-01
The study has focused on the retrospective analysis of cases of coexisting congenital aortic stenosis (AS) and pulmonary artery stenosis (PS) in dogs. The research included 5463 dogs which were referred for cardiological examination (including clinical examination, ECG and echocardiography) between 2004 and 2014. Aortic stenosis and PS stenosis were detected in 31 dogs. This complex defect was the most commonly diagnosed in Boxers - 7 dogs, other breeds were represented by: 4 cross-breed dogs, 2 Bichon Maltais, 3 Miniature Pinschers, 2 Bernese Mountain Dogs, 2 French Bulldogs, and individuals of following breeds: Bichon Frise, Bull Terrier, Czech Wolfdog, German Shepherd, Hairless Chinese Crested Dog, Miniature Schnauzer, Pug, Rottweiler, Samoyed, West Highland White Terrier and Yorkshire Terrier. In all the dogs, the murmurs could be heard, graded from 2 to 5 (on a scale of 1-6). Besides, in 9 cases other congenital defects were diagnosed: patent ductus arteriosus, mitral valve dysplasia, pulmonary or aortic valve regurgitation, tricuspid valve dysplasia, ventricular or atrial septal defect. The majority of the dogs suffered from pulmonary valvular stenosis (1 dog had supravalvular pulmonary artery stenosis) and subvalvular aortic stenosis (2 dogs had valvular aortic stenosis). Conclusions and clinical relevance - co-occurrence of AS and PS is the most common complex congenital heart defect. Boxer breed was predisposed to this complex defect. It was found that coexisting AS and PS is more common in male dogs and the degree of PS and AS was mostly similar.
Lichenoid keratosis is frequently misdiagnosed as basal cell carcinoma.
Maor, D; Ondhia, C; Yu, L L; Chan, J J
2017-08-01
Lichenoid keratosis (LK), also known as benign lichenoid keratosis or lichen planus-like keratosis, is a solitary, pink to red-brown scaly plaque representing a host immunological response to a variety of precursor lesions. LK is often misdiagnosed as a dermatological malignancy owing to its clinical resemblance to basal cell carcinoma (BCC) or Bowen disease. We performed a retrospective analysis of the pathology records of a series of LK lesions with reference to the demographic features and accuracy of clinical diagnosis. The pathology records from 2008 to 2009 of 263 consecutive patients with a histological diagnosis of LK from a specialized skin laboratory were retrieved. Data relating to clinical diagnosis, age, sex, anatomical location, time of year of presentation and any coexistent pathological lesions adjacent to the LK were recorded. Mean age at presentation was 64 years (range 34-96), and 58% of patients were female. The most common anatomical site was the chest/anterior torso, followed by the back and legs. The most common coexisting lesion was solar keratosis at 14%, followed by seborrhoeic keratosis (SK) at 7.8%. The correct clinical diagnosis of LK was made in 29.5% of cases. The most common clinical diagnosis was BCC (47%), while SK was the preferred diagnosis in 18%. A clinical diagnosis was not given in 5.5% of cases. In conclusion, it appears that LK is frequently misdiagnosed, with misdiagnosis occurring in > 70% of cases in this study. © 2017 British Association of Dermatologists.
Paull, Brett; Barron, Leon
2004-08-13
A review of the application of ion chromatography to the determination of haloacetic acids in drinking water is given. As it requires no sample derivatisation, ion chromatography in its various modes, such as ion-exchange, ion-interaction and ion-exclusion chromatography, is increasingly being investigated as a simpler alternative to gas chromatographic methods for the determination of polar disinfection by-products (DBPs) in drinking waters. Detection limits quoted for the regulated haloacetic acids (HAA5), are commonly in the mid to low microg/L range, however, in most cases analyte preconcentration is still necessary for detection at concentrations commonly found in actual drinking water samples. The coupling of ion chromatography to electrospray mass spectrometry provides a potential future direction, with improved sensitivity and selectivity compared to conductivity based detection, however associated cost and complexity for routine analysis is currently relatively high.
Feng, Xiao-Liang; He, Yun-biao; Liang, Yi-Zeng; Wang, Yu-Lin; Huang, Lan-Fang; Xie, Jian-Wei
2013-01-01
Gas chromatography-mass spectrometry and multivariate curve resolution were applied to the differential analysis of the volatile components in Agrimonia eupatoria specimens from different plant parts. After extracted with water distillation method, the volatile components in Agrimonia eupatoria from leaves and roots were detected by GC-MS. Then the qualitative and quantitative analysis of the volatile components in the main root of Agrimonia eupatoria was completed with the help of subwindow factor analysis resolving two-dimensional original data into mass spectra and chromatograms. 68 of 87 separated constituents in the total ion chromatogram of the volatile components were identified and quantified, accounting for about 87.03% of the total content. Then, the common peaks in leaf were extracted with orthogonal projection resolution method. Among the components determined, there were 52 components coexisting in the studied samples although the relative content of each component showed difference to some extent. The results showed a fair consistency in their GC-MS fingerprint. It was the first time to apply orthogonal projection method to compare different plant parts of Agrimonia eupatoria, and it reduced the burden of qualitative analysis as well as the subjectivity. The obtained results proved the combined approach powerful for the analysis of complex Agrimonia eupatoria samples. The developed method can be used to further study and quality control of Agrimonia eupatoria. PMID:24286016
Feng, Xiao-Liang; He, Yun-Biao; Liang, Yi-Zeng; Wang, Yu-Lin; Huang, Lan-Fang; Xie, Jian-Wei
2013-01-01
Gas chromatography-mass spectrometry and multivariate curve resolution were applied to the differential analysis of the volatile components in Agrimonia eupatoria specimens from different plant parts. After extracted with water distillation method, the volatile components in Agrimonia eupatoria from leaves and roots were detected by GC-MS. Then the qualitative and quantitative analysis of the volatile components in the main root of Agrimonia eupatoria was completed with the help of subwindow factor analysis resolving two-dimensional original data into mass spectra and chromatograms. 68 of 87 separated constituents in the total ion chromatogram of the volatile components were identified and quantified, accounting for about 87.03% of the total content. Then, the common peaks in leaf were extracted with orthogonal projection resolution method. Among the components determined, there were 52 components coexisting in the studied samples although the relative content of each component showed difference to some extent. The results showed a fair consistency in their GC-MS fingerprint. It was the first time to apply orthogonal projection method to compare different plant parts of Agrimonia eupatoria, and it reduced the burden of qualitative analysis as well as the subjectivity. The obtained results proved the combined approach powerful for the analysis of complex Agrimonia eupatoria samples. The developed method can be used to further study and quality control of Agrimonia eupatoria.
Genetic and forensic implications in epilepsy and cardiac arrhythmias: a case series.
Partemi, Sara; Vidal, Monica Coll; Striano, Pasquale; Campuzano, Oscar; Allegue, Catarina; Pezzella, Marianna; Elia, Maurizio; Parisi, Pasquale; Belcastro, Vincenzo; Casellato, Susanna; Giordano, Lucio; Mastrangelo, Massimo; Pietrafusa, Nicola; Striano, Salvatore; Zara, Federico; Bianchi, Amedeo; Buti, Daniela; La Neve, Angela; Tassinari, Carlo Alberto; Oliva, Antonio; Brugada, Ramon
2015-05-01
Epilepsy affects approximately 3% of the world's population, and sudden death is a significant cause of death in this population. Sudden unexpected death in epilepsy (SUDEP) accounts for up to 17% of all these cases, which increases the rate of sudden death by 24-fold as compared to the general population. The underlying mechanisms are still not elucidated, but recent studies suggest the possibility that a common genetic channelopathy might contribute to both epilepsy and cardiac disease to increase the incidence of death via a lethal cardiac arrhythmia. We performed genetic testing in a large cohort of individuals with epilepsy and cardiac conduction disorders in order to identify genetic mutations that could play a role in the mechanism of sudden death. Putative pathogenic disease-causing mutations in genes encoding cardiac ion channel were detected in 24% of unrelated individuals with epilepsy. Segregation analysis through genetic screening of the available family members and functional studies are crucial tasks to understand and to prove the possible pathogenicity of the variant, but in our cohort, only two families were available. Despite further research should be performed to clarify the mechanism of coexistence of both clinical conditions, genetic analysis, applied also in post-mortem setting, could be very useful to identify genetic factors that predispose epileptic patients to sudden death, helping to prevent sudden death in patients with epilepsy.
Enander, Jesper; Ivanov, Volen Z; Mataix-Cols, David; Kuja-Halkola, Ralf; Ljótsson, Brjánn; Lundström, Sebastian; Pérez-Vigil, Ana; Monzani, Benedetta; Lichtenstein, Paul; Rück, Christian
2018-02-28
Body dysmorphic disorder (BDD) usually begins during adolescence but little is known about the prevalence, etiology, and patterns of comorbidity in this age group. We investigated the prevalence of BDD symptoms in adolescents and young adults. We also report on the relative importance of genetic and environmental influences on BDD symptoms, and the risk for co-existing psychopathology. Prevalence of BDD symptoms was determined by a validated cut-off on the Dysmorphic Concerns Questionnaire (DCQ) in three population-based twin cohorts at ages 15 (n = 6968), 18 (n = 3738), and 20-28 (n = 4671). Heritability analysis was performed using univariate model-fitting for the DCQ. The risk for co-existing psychopathology was expressed as odds ratios (OR). The prevalence of clinically significant BDD symptoms was estimated to be between 1 and 2% in the different cohorts, with a significantly higher prevalence in females (1.3-3.3%) than in males (0.2-0.6%). The heritability of body dysmorphic concerns was estimated to be 49% (95% CI 38-54%) at age 15, 39% (95% CI 30-46) at age 18, and 37% (95% CI 29-42) at ages 20-28, with the remaining variance being due to non-shared environment. ORs for co-existing neuropsychiatric and alcohol-related problems ranged from 2.3 to 13.2. Clinically significant BDD symptoms are relatively common in adolescence and young adulthood, particularly in females. The low occurrence of BDD symptoms in adolescent boys may indicate sex differences in age of onset and/or etiological mechanisms. BDD symptoms are moderately heritable in young people and associated with an increased risk for co-existing neuropsychiatric and alcohol-related problems.
Thorn, Christine Johanna; Bissinger, Kerstin; Thorn, Simon; Bogner, Franz Xaver
2016-01-01
Successful learning is the integration of new knowledge into existing schemes, leading to an integrated and correct scientific conception. By contrast, the co-existence of scientific and alternative conceptions may indicate a fragmented knowledge profile. Every learner is unique and thus carries an individual set of preconceptions before classroom engagement due to prior experiences. Hence, instructors and teachers have to consider the heterogeneous knowledge profiles of their class when teaching. However, determinants of fragmented knowledge profiles are not well understood yet, which may hamper a development of adapted teaching schemes. We used a questionnaire-based approach to assess conceptual knowledge of tree assimilation and wood synthesis surveying 885 students of four educational levels: 6th graders, 10th graders, natural science freshmen and other academic studies freshmen. We analysed the influence of learner's characteristics such as educational level, age and sex on the coexistence of scientific and alternative conceptions. Within all subsamples well-known alternative conceptions regarding tree assimilation and wood synthesis coexisted with correct scientific ones. For example, students describe trees to be living on "soil and sunshine", representing scientific knowledge of photosynthesis mingled with an alternative conception of trees eating like animals. Fragmented knowledge profiles occurred in all subsamples, but our models showed that improved education and age foster knowledge integration. Sex had almost no influence on the existing scientific conceptions and evolution of knowledge integration. Consequently, complex biological issues such as tree assimilation and wood synthesis need specific support e.g. through repeated learning units in class- and seminar-rooms in order to help especially young students to handle and overcome common alternative conceptions and appropriately integrate scientific conceptions into their knowledge profile.
Diao, Zeng-Hui; Du, Jian-Jun; Jiang, Dan; Kong, Ling-Jun; Huo, Wen-Yi; Liu, Cui-Mei; Wu, Qi-Hang; Xu, Xiang-Rong
2018-06-13
Cr 6+ and Pb 2+ are both highly toxic pollutants and commonly co-exist in some industrial effluents and contaminated waters. In this study, simultaneous removal of Cr 6+ and Pb 2+ by a novel sewage sludge-derived biochar immobilized nanoscale zero-valent iron (SSB-nZVI) was systematically investigated. It was well demonstrated that a porous structure was successfully formed on the SSB-nZVI when the starch was used as an additive. A synergistic effect on the adsorption and reduction over the SSB-nZVI was achieved, resulting in nearly 90 and 82% of Cr 6+ and Pb 2+ removal within 30 min, respectively. Cr 6+ was reduced prior to Pb 2+ . A low pH could accelerate the corrosion of nZVI as well as phosphate leaching. When Malachite green was added as a coexisting organic pollutant, its effective removal was found due to the formation of a Fenton-like system. The SSB-nZVI could be run consecutively three times with a relatively satisfactory performance. Most of Cr 6+ was converted into Cr 2 O 3 and Cr(OH) 3 on the SSB-nZVI surface, whereas most of Pb 2+ species existed as Pb(OH) 2 (or PbO). A possible reaction mechanism on the SSB-nZVI involved the adsorption, reduction and precipitation of both Cr 6+ and Pb 2+ over the particles. Present study sheds light on the insight of the fate and transport of Cr 6+ and Pb 2+ in aquatic environment, as well provides helpful guide for the remediation of coexistence of pollutants in real applications. Copyright © 2018 Elsevier B.V. All rights reserved.
Gao, Yan; Jiang, Xiaoqiong; Lin, Dongjia; Chen, Yanhuo; Tong, Zhongchun
2016-08-01
Enterococcus faecalis is the most frequently detected species in root canal-treated teeth, and it is able to survive under starvation conditions. However, persistent periapical disease is often caused by multispecies. The aim of this study was to explore the survival of E. faecalis in starvation conditions and biofilm formation with the 4 common pathogenic species. A dual-species model of Candida albicans, Streptococcus gordonii, Actinomyces viscosus, or Lactobacillus acidophilus in combination with E. faecalis was established and allowed to grow in phosphate-buffered saline for the examination of starvation survival. Cefuroxime sodium and vancomycin at a concentration of 100 mg/L were added into brain-heart infusion plate agar to count the 2 bacteria separately in the dual species. Scanning electron microscopy was used to observe the dual species and multiple species on the root canal dentin of bovine teeth for 48 hours. A confocal laser scanning microscope was used to show the 4 groups of dual-species biofilms on substrates with glass bottoms for 48 hours. E. faecalis was more resistant to starvation in coexistence with C. albicans, S. gordonii, A. viscosus, or L. acidophilus, and S. gordonii was completely inhibited in coexistence with E. faecalis. The dual-species biofilm showed that E. faecalis formed thicker and denser biofilms on the root canal dentin and glass slides in coexistence with S. gordonii and A. viscosus than C. albicans and L. acidophilus. The multispecies community is conducive to the resistance to starvation of E. faecalis and biofilm formation in root canals. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
Thorn, Simon; Bogner, Franz Xaver
2016-01-01
Successful learning is the integration of new knowledge into existing schemes, leading to an integrated and correct scientific conception. By contrast, the co-existence of scientific and alternative conceptions may indicate a fragmented knowledge profile. Every learner is unique and thus carries an individual set of preconceptions before classroom engagement due to prior experiences. Hence, instructors and teachers have to consider the heterogeneous knowledge profiles of their class when teaching. However, determinants of fragmented knowledge profiles are not well understood yet, which may hamper a development of adapted teaching schemes. We used a questionnaire-based approach to assess conceptual knowledge of tree assimilation and wood synthesis surveying 885 students of four educational levels: 6th graders, 10th graders, natural science freshmen and other academic studies freshmen. We analysed the influence of learner’s characteristics such as educational level, age and sex on the coexistence of scientific and alternative conceptions. Within all subsamples well-known alternative conceptions regarding tree assimilation and wood synthesis coexisted with correct scientific ones. For example, students describe trees to be living on “soil and sunshine”, representing scientific knowledge of photosynthesis mingled with an alternative conception of trees eating like animals. Fragmented knowledge profiles occurred in all subsamples, but our models showed that improved education and age foster knowledge integration. Sex had almost no influence on the existing scientific conceptions and evolution of knowledge integration. Consequently, complex biological issues such as tree assimilation and wood synthesis need specific support e.g. through repeated learning units in class- and seminar-rooms in order to help especially young students to handle and overcome common alternative conceptions and appropriately integrate scientific conceptions into their knowledge profile. PMID:26807974
Prevalence and Impact of Coexistent Bicuspid Aortic Valve in Hypertrophic Cardiomyopathy.
Padang, Ratnasari; Gersh, Bernard J; Ommen, Steve R; Geske, Jeffrey B
2018-01-01
The association between bicuspid aortic valve (BAV) and hypertrophic cardiomyopathy (HCM) has been reported but its true prevalence is unknown. This study investigated the prevalence and clinical impact of coexistent BAV in a large referral HCM population. Retrospective analysis of 3765 echocardiograms between 2004 and 2014 in 2640 consecutive patients with HCM was performed to assess for BAV. Patients with coexistent conditions were studied. Twenty-three patients (0.9%) were identified with coexisting BAV and HCM. Mean age was 52±16years, 18 males (78%), 16 with NYHA functional class I/II at initial evaluation (70%). A family history of HCM was present in five patients (22%); none had a family history of BAV or aortopathy. Maximal left ventricular wall thickness was 24±6mm; the majority had either reverse curve or sigmoid septal morphology. Moderate or greater aortic valve dysfunction was present in seven patients (30%), BAV-related aortopathy in 18 patients (78%) and dynamic left ventricular outflow tract (LVOT) obstruction in nine patients (39%). Three patients had combined LVOT obstruction and aortic stenosis. Median time from diagnosis of BAV or HCM to last follow-up was 11±12.5years. At last follow-up, 22% had undergone BAV-related surgeries, 30% had septal reduction therapy (SRT), and 17% had combined SRT and BAV-related surgeries. Overall survival was 95% at 10 years. This study reported a 0.9% prevalence of BAV among HCM population, similar to the general population. Aortopathy and LVOT obstruction were common, necessitating cardiac interventions in over one-third of cases. Long-term survival appeared favourable. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.
The Differential Effects of Anesthetics on Bacterial Behaviors
Chamberlain, Matthew; Koutsogiannaki, Sophia; Schaefers, Matthew; Babazada, Hasan; Liu, Renyu; Yuki, Koichi
2017-01-01
Volatile anesthetics have been in clinical use for a long period of time and are considered to be promiscuous by presumably interacting with several ion channels in the central nervous system to produce anesthesia. Because ion channels and their existing evolutionary analogues, ion transporters, are very important in various organisms, it is possible that volatile anesthetics may affect some bacteria. In this study, we hypothesized that volatile anesthetics could affect bacterial behaviors. We evaluated the impact of anesthetics on bacterial growth, motility (swimming and gliding) and biofilm formation of four common bacterial pathogens in vitro. We found that commonly used volatile anesthetics isoflurane and sevoflurane affected bacterial motility and biofilm formation without any effect on growth of the common bacterial pathogens studied here. Using available Escherichia coli gene deletion mutants of ion transporters and in silico molecular docking, we suggested that these altered behaviors might be at least partly via the interaction of volatile anesthetics with ion transporters. PMID:28099463
Coexisting lumbar spondylosis in patients undergoing TKA: how common and how serious?
Chang, Chong Bum; Park, Kun Woo; Kang, Yeon Gwi; Kim, Tae Kyun
2014-02-01
Information on the coexistence of lumbar spondylosis and its influence on overall levels of pain and function in patients with advanced knee osteoarthritis (OA) undergoing total knee arthroplasty (TKA) would be valuable for patient consultation and management. The purposes of this study were to document the prevalence and severity of coexisting lumbar spondylosis in patients with advanced knee OA undergoing TKA and to determine whether the coexisting lumbar spondylosis at the time of TKA adversely affects clinical scores in affected patients before and 2 years after TKA. Radiographic lumbar spine degeneration and lumbar spine symptoms including lower back pain, radiating pain at rest, and radiating pain with activity were assessed in 225 patients undergoing TKA. In addition, the WOMAC score and the SF-36 scores were evaluated before and 2 years after TKA. Potential associations of radiographic lumbar spine degeneration and lumbar spine symptom severities with pre- and postoperative WOMAC subscales and SF-36 scores were examined. All 225 patients had radiographic degeneration of the lumbar spine, and the large majority (89% [200 of 225]) had either moderate or severe spondylosis (72% and 17%, respectively). A total of 114 patients (51%) had at least one moderate or severe lumbar spine symptom. No association was found between radiographic severity of lumbar spine degeneration and pre- and postoperative clinical scores. In terms of lumbar spine symptoms, more severe symptoms were likely to adversely affect the preoperative WOMAC and SF-36 physical component summary (PCS) scores, but most of these adverse effects improved by 2 years after TKA with the exception of the association between severe radiating pain during activity and a poorer postoperative SF-36 PCS score (regression coefficient = -5.41, p = 0.015). Radiographic lumbar spine degeneration and lumbar spine symptoms are common among patients with advanced knee OA undergoing TKA. Severe lumbar spine symptoms (visual analog scale score of ≥ 7) were likely to adversely affect the preoperative clinical scores of patients undergoing TKA; however, most of the adverse effects were not found 2 years after TKA. Nevertheless, because preexisting severe radiating pain during activity may be a source of a poorer outcome after TKA, careful patient consultation regarding this potential poorer prognosis after TKA needs to be provided to the patient with this symptom.
Hydration of copper(II): new insights from density functional theory and the COSMO solvation model.
Bryantsev, Vyacheslav S; Diallo, Mamadou S; van Duin, Adri C T; Goddard, William A
2008-09-25
The hydrated structure of the Cu(II) ion has been a subject of ongoing debate in the literature. In this article, we use density functional theory (B3LYP) and the COSMO continuum solvent model to characterize the structure and stability of [Cu(H2O)n](2+) clusters as a function of coordination number (4, 5, and 6) and cluster size (n = 4-18). We find that the most thermodynamically favored Cu(II) complexes in the gas phase have a very open four-coordinate structure. They are formed from a stable square-planar [Cu(H2O)8](2+) core stabilized by an unpaired electron in the Cu(II) ion d(x(2)-y(2)) orbital. This is consistent with cluster geometries suggested by recent mass-spectrometric experiments. In the aqueous phase, we find that the more compact five-coordinate square-pyramidal geometry is more stable than either the four-coordinate or six-coordinate clusters in agreement with recent combined EXAFS and XANES studies of aqueous solutions of Cu(II). However, a small energetic difference (approximately 1.4 kcal/mol) between the five- and six-coordinate models with two full hydration shells around the metal ion suggests that both forms may coexist in solution.
Li, Xiong; Zhang, Yufeng; Zeng, Xing; Yang, Liu; Deng, Yuanhui
2011-09-15
In this study, a fast and reliable method based on an ultra-high-pressure liquid chromatography coupled with photodiode-array detection (PDA) and a linear ion trap high-resolution mass spectrometer (LTQ-Orbitrap XL) has been developed for the identification of bioactive constituents in the whole plant of Sarcandra glabra and its related four preparations. By accurate mass measurements within 5 ppm error for each molecular ion and subsequent fragment ions in routine analysis, 50 compounds, including organic acids, caffeoyl derivatives, flavonoids, coumarins and terpenoids, were identified or tentatively characterized. Among them, 6,7,8-trihydroxycoumarin-O-rhamnopyranoside (17), (2R)-naringenin-6-C-B-D-glucopyranosyl-(6→1)-apiose (25) and (2S)-naringenin-6-C-B-D-glucopyranosyl-(6→1)-apiose (27) were tentatively identified as new compounds. Besides, 21 of these compounds were coexisting in four preparations of Sarcandra glabra. Fragmentation behaviors of the four major categories of compounds were also investigated. This established UPLC-PDA/ESI-MS(n) method was reliable and effective for the separation and identification of the major constituents and would be the basis for quality control of Sarcandra glabra and its related preparations. Copyright © 2011 John Wiley & Sons, Ltd.
Vipin, Adavan Kiliyankil; Fugetsu, Bunshi; Sakata, Ichiro; Isogai, Akira; Endo, Morinobu; Li, Mingda; Dresselhaus, Mildred S
2016-11-15
On 11 March 2011, the day of the unforgettable disaster of the 9 magnitude Tohoku earthquake and quickly followed by the devastating Tsunami, a damageable amount of radionuclides had dispersed from the Fukushima Daiichi's damaged nuclear reactors. Decontamination of the dispersed radionuclides from seawater and soil, due to the huge amounts of coexisting ions with competitive functionalities, has been the topmost difficulty. Ferric hexacyanoferrate, also known as Prussian blue (PB), has been the most powerful material for selectively trapping the radioactive cesium ions; its high tendency to form stable colloids in water, however, has made PB to be impossible for the open-field radioactive cesium decontamination applications. A nano/nano combinatorial approach, as is described in this study, has provided an ultimate solution to this intrinsic colloid formation difficulty of PB. Cellulose nanofibers (CNF) were used to immobilize PB via the creation of CNF-backboned PB. The CNF-backboned PB (CNF/PB) was found to be highly tolerant to water and moreover, it gave a 139 mg/g capability and a million (10 6 ) order of magnitude distribution coefficient (K d ) for absorbing of the radioactive cesium ion. Field studies on soil and seawater decontaminations in Fukushima gave satisfactory results, demonstrating high capabilities of CNF/PB for practical applications.
Lu, Chenyang; Jin, Ke; Béland, Laurent K; Zhang, Feifei; Yang, Taini; Qiao, Liang; Zhang, Yanwen; Bei, Hongbin; Christen, Hans M; Stoller, Roger E; Wang, Lumin
2016-02-01
Energetic ions have been widely used to evaluate the irradiation tolerance of structural materials for nuclear power applications and to modify material properties. It is important to understand the defect production, annihilation and migration mechanisms during and after collision cascades. In this study, single crystalline pure nickel metal and single-phase concentrated solid solution alloys of 50%Ni50%Co (NiCo) and 50%Ni50%Fe (NiFe) without apparent preexisting defect sinks were employed to study defect dynamics under ion irradiation. Both cross-sectional transmission electron microscopy characterization (TEM) and Rutherford backscattering spectrometry channeling (RBS-C) spectra show that the range of radiation-induced defect clusters far exceed the theoretically predicted depth in all materials after high-dose irradiation. Defects in nickel migrate faster than in NiCo and NiFe. Both vacancy-type stacking fault tetrahedra (SFT) and interstitial loops coexist in the same region, which is consistent with molecular dynamics simulations. Kinetic activation relaxation technique (k-ART) simulations for nickel showed that small vacancy clusters, such as di-vacancies and tri-vacancies, created by collision cascades are highly mobile, even at room temperature. The slower migration of defects in the alloy along with more localized energy dissipation of the displacement cascade may lead to enhanced radiation tolerance.
Vipin, Adavan Kiliyankil; Fugetsu, Bunshi; Sakata, Ichiro; Isogai, Akira; Endo, Morinobu; Li, Mingda; Dresselhaus, Mildred S.
2016-01-01
On 11 March 2011, the day of the unforgettable disaster of the 9 magnitude Tohoku earthquake and quickly followed by the devastating Tsunami, a damageable amount of radionuclides had dispersed from the Fukushima Daiichi’s damaged nuclear reactors. Decontamination of the dispersed radionuclides from seawater and soil, due to the huge amounts of coexisting ions with competitive functionalities, has been the topmost difficulty. Ferric hexacyanoferrate, also known as Prussian blue (PB), has been the most powerful material for selectively trapping the radioactive cesium ions; its high tendency to form stable colloids in water, however, has made PB to be impossible for the open-field radioactive cesium decontamination applications. A nano/nano combinatorial approach, as is described in this study, has provided an ultimate solution to this intrinsic colloid formation difficulty of PB. Cellulose nanofibers (CNF) were used to immobilize PB via the creation of CNF-backboned PB. The CNF-backboned PB (CNF/PB) was found to be highly tolerant to water and moreover, it gave a 139 mg/g capability and a million (106) order of magnitude distribution coefficient (Kd) for absorbing of the radioactive cesium ion. Field studies on soil and seawater decontaminations in Fukushima gave satisfactory results, demonstrating high capabilities of CNF/PB for practical applications. PMID:27845441
Removal of Cs+ from water and soil by ammonium-pillared montmorillonite/Fe3O4 composite.
Zheng, Xianming; Dou, Junfeng; Yuan, Jing; Qin, Wei; Hong, Xiaoxi; Ding, Aizhong
2017-06-01
To remove cesium ions from water and soil, a novel adsorbent was synthesized by following a one-step co-precipitation method and using non-toxic raw materials. By combining ammonium-pillared montmorillonite (MMT) and magnetic nanoparticles (Fe 3 O 4 ), an MMT/Fe 3 O 4 composite was prepared and characterized. The adsorbent exhibited high selectivity of Cs + and could be rapidly separated from the mixed solution under an external magnetic field. Above all, the adsorbent had high removal efficiency in cesium-contaminated samples (water and soil) and also showed good recycling performance, indicating that the MMT/Fe 3 O 4 composite could be widely applied to the remediation of cesium-contaminated environments. It was observed that the pH, solid/liquid ratio and initial concentration affected adsorption capacity. In the presence of coexisting ions, the adsorption capacity decreased in the order of Ca 2+ >Mg 2+ >K + >Na + , which is consistent with our theoretical prediction. The adsorption behavior of this new adsorbent could be expressed by the pseudo-second-order model and Freundlich isotherm. In addition, the adsorption mechanism of Cs + was NH 4 + ion exchange and surface hydroxyl group coordination, with the former being more predominant. Copyright © 2016. Published by Elsevier B.V.
Lu, Chenyang; Jin, Ke; Béland, Laurent K.; Zhang, Feifei; Yang, Taini; Qiao, Liang; Zhang, Yanwen; Bei, Hongbin; Christen, Hans M.; Stoller, Roger E.; Wang, Lumin
2016-01-01
Energetic ions have been widely used to evaluate the irradiation tolerance of structural materials for nuclear power applications and to modify material properties. It is important to understand the defect production, annihilation and migration mechanisms during and after collision cascades. In this study, single crystalline pure nickel metal and single-phase concentrated solid solution alloys of 50%Ni50%Co (NiCo) and 50%Ni50%Fe (NiFe) without apparent preexisting defect sinks were employed to study defect dynamics under ion irradiation. Both cross-sectional transmission electron microscopy characterization (TEM) and Rutherford backscattering spectrometry channeling (RBS-C) spectra show that the range of radiation-induced defect clusters far exceed the theoretically predicted depth in all materials after high-dose irradiation. Defects in nickel migrate faster than in NiCo and NiFe. Both vacancy-type stacking fault tetrahedra (SFT) and interstitial loops coexist in the same region, which is consistent with molecular dynamics simulations. Kinetic activation relaxation technique (k-ART) simulations for nickel showed that small vacancy clusters, such as di-vacancies and tri-vacancies, created by collision cascades are highly mobile, even at room temperature. The slower migration of defects in the alloy along with more localized energy dissipation of the displacement cascade may lead to enhanced radiation tolerance. PMID:26829570
Qiu, Hui; Liang, Chen; Zhang, Xiaolin; Chen, Mindong; Zhao, Yunxia; Tao, Tao; Xu, Zhengwen; Liu, Gang
2015-09-23
Advanced removal of phosphate by low-cost adsorbents from municipal wastewater or industrial effluents is an effective and economic way to prevent the occurrence of eutrophication. Here, we proposed a novel method to immobilize hydrous zirconium oxide nanoparticle within quaternary-aminated wheat straw, and obtained an inexpensive, eco-friendly nanocomposite Ws-N-Zr. The biomass-based Ws-N-Zr exhibited higher preference toward phosphate than commercial anion exchanger IRA-900 when competing sulfate ions coexisted at relatively high levels. Such excellent performance of Ws-N-Zr resulted from its specific hybrid structure, the quaternary ammonium groups bonded on the host favor the preconcentration of phosphate ions inside the wheat straw based on Donnan effect, and the encapsulated HZO nanoparticle exhibits preferable sequestration of phosphate ions through specific interaction, as further demonstrated by FTIR and X-ray photoelectron spectroscopy. Cycle adsorption and regeneration experiments demonstrated that Ws-N-Zr could be employed for repeated use without significant capacity loss, when the binary NaOH-NaCl solution was employed as the regenerant. The influence of solution pH and contact time was also examined. The results suggested that Ws-N-Zr has a great potential in efficient removal of phosphate in contaminated waters.
The pathway between conflict and reconciliation: coexistence as an evolutionary process.
Sluzki, Carlos E
2010-02-01
A normative sequence of six stages is proposed to describe the process of evolution from open conflict to harmonious coexistence, as well at its devolution from the latter to the former. The stages may be termed Confrontation, Truce, Collaboration, Cooperation, Interdependence and Integration. Each of the six stages constitutes an amalgam of practices, narratives and prevalent emotions in a relational "game" that tends to resist change. At the stage of Confrontation, each party assumes that any act of the other is motivated by ill intent, and active hostility prevails. In Truce or Freeze, acts of hostility are curtailed by a real or virtual "neutral zone" controlled by powerful third parties. The dominant emotions are resentment, anger, and mistrust. Collaboration retains some assumptions of ill intent while certain activities in common are carried out. The third party looses visibility, and the dominant emotions include ambivalence. Cooperation entails the assumption of neutral intent of self and other, while activities in common are planned and carried out. Key emotions include cautious compassion for the other. Interdependence is characterized by active involvement in planning toward the common good. The dominant emotions are trust and forgiveness. At the other end of the spectrum, parties at the stage of Integration are actively involved in projects aimed at the common good and each supports the other's growth. The dominant emotions are solidarity and a friendly trust. Movement from one stage to another shares certain characteristics with other complex systems. For professionals aiming to facilitate evolutionary change, whether in interpersonal or in international relations, the systemic cohesion of each stage constitutes the main challenge, and the promise of similar cohesion at the next stage provides the main hope.
Application of thermodynamics to silicate crystalline solutions
NASA Technical Reports Server (NTRS)
Saxena, S. K.
1972-01-01
A review of thermodynamic relations is presented, describing Guggenheim's regular solution models, the simple mixture, the zeroth approximation, and the quasi-chemical model. The possibilities of retrieving useful thermodynamic quantities from phase equilibrium studies are discussed. Such quantities include the activity-composition relations and the free energy of mixing in crystalline solutions. Theory and results of the study of partitioning of elements in coexisting minerals are briefly reviewed. A thermodynamic study of the intercrystalline and intracrystalline ion exchange relations gives useful information on the thermodynamic behavior of the crystalline solutions involved. Such information is necessary for the solution of most petrogenic problems and for geothermometry. Thermodynamic quantities for tungstates (CaWO4-SrWO4) are calculated.
Compact Dual Ion Composition Experiment for space plasmas—CoDICE
NASA Astrophysics Data System (ADS)
Desai, M. I.; Ogasawara, K.; Ebert, R. W.; Allegrini, F.; McComas, D. J.; Livi, S.; Weidner, S. E.
2016-07-01
The Compact Dual Ion Composition Experiment—CoDICE—simultaneously provides high-quality plasma and energetic ion composition measurements over six decades in energy in a wide variety of space plasma environments. CoDICE measures two critical ion populations in space plasmas: (1) Elemental and charge state composition, and 3-D velocity distributions of <10 eV/q-40 keV/q plasma ions; and (2) Elemental composition, energy spectra, and angular distributions of ˜30 keV->10 MeV energetic ions. CoDICE uses a novel, integrated, common time-of-flight subsystem that provides several advantages over the commonly used separate plasma and energetic ion sensors currently flying on several space missions. These advantages include reduced mass and volume compared to two separate instruments, reduced shielding in high-radiation environments, and simplified spacecraft interface and accommodation requirements. This paper describes the operation principles, electro-optic simulation results and applies the CoDICE concept for measuring plasma and energetic ion populations in Jupiter's magnetosphere.
Jin, Cheng; Liu, Huimin; Kong, Xianggui; Yan, Hong; Lei, Xiaodong
2018-02-27
Phytate intercalated MgAl layered double hydroxide (MgAl-LDH) was prepared by an anion exchange method with the precursor NO 3 - containing MgAl-LDH. The final as-synthesized product [Mg 0.69 Al 0.31 (OH) 2 ] (phytateNa 6 ) 0.05 (NO 3 ) 0.01 ·mH 2 O (phytate-LDH) has highly selective adsorption ability for some metal ions and can be used to enrich rare earth metal ions in mixed solution, such as Pr 3+ and Ce 3+ from a mixed solution of them with Pb 2+ and Co 2+ . At first, phytate-LDH has good adsorption performance for these ions in single metal ion solutions. At low concentration (below 10 mg L -1 ), all the capture rates of the four metal ions were more than 97%, for highly toxic Pb 2+ it was even up to nearly 100%, and a high capture rate (99.87%) was maintained for Pb 2+ at a high concentration (100 mg L -1 ). When all the four metal ions are co-existing in aqueous solution, the selectivity order is Pb 2+ ≫ Pr 3+ ≈ Ce 3+ > Co 2+ . In a solution containing mixtures of the three metal ions of Pr 3+ , Ce 3+ , and Co 2+ , the selectivity order is Pr 3+ ≈ Ce 3+ ≫ Co 2+ , and in a solution containing mixtures of Pr 3+ with Co 2+ and Ce 3+ with Co 2+ , the selectivity orders are Pr 3+ ≫ Co 2+ and Ce 3+ ≫ Co 2+ , respectively. The high selectivity and adsorption capacities for Pb 2+ , Co 2+ , Pr 3+ , and Ce 3+ result in the efficient removal of Pb 2+ and enrichment of the rare earth metal ions Pr 3+ and Ce 3+ by phytate-LDH. Based on the elemental analysis, it is found that the difference of the adsorption capacities is mainly due to the different coordination number of them with phytate-LDH. With molecular simulation, we believe that the adsorption selectivity is due to the difference of the binding energy between the metal ion and phytate-LDH. Therefore, the phytate-LDH is promising for the enrichment and/or purification of the rare earth metal ions and removal of toxic metal ions from waste water.
NASA Astrophysics Data System (ADS)
Laramie, Sydney M.; Milshtein, Jarrod D.; Breault, Tanya M.; Brushett, Fikile R.; Thompson, Levi T.
2016-09-01
Non-aqueous redox flow batteries (NAqRFBs) have recently received considerable attention as promising high energy density, low cost grid-level energy storage technologies. Despite these attractive features, NAqRFBs are still at an early stage of development and innovative design techniques are necessary to improve performance and decrease costs. In this work, we investigate multi-electron transfer, common ion exchange NAqRFBs. Common ion systems decrease the supporting electrolyte requirement, which subsequently improves active material solubility and decreases electrolyte cost. Voltammetric and electrolytic techniques are used to study the electrochemical performance and chemical compatibility of model redox active materials, iron (II) tris(2,2‧-bipyridine) tetrafluoroborate (Fe(bpy)3(BF4)2) and ferrocenylmethyl dimethyl ethyl ammonium tetrafluoroborate (Fc1N112-BF4). These results help disentangle complex cycling behavior observed in flow cell experiments. Further, a simple techno-economic model demonstrates the cost benefits of employing common ion exchange NAqRFBs, afforded by decreasing the salt and solvent contributions to total chemical cost. This study highlights two new concepts, common ion exchange and multi-electron transfer, for NAqRFBs through a demonstration flow cell employing model active species. In addition, the compatibility analysis developed for asymmetric chemistries can apply to other promising species, including organics, metal coordination complexes (MCCs) and mixed MCC/organic systems, enabling the design of low cost NAqRFBs.
Naked-eye sensor for rapid determination of mercury ion.
Liu, Jing; Wu, Dapeng; Yan, Xiaohui; Guan, Yafeng
2013-11-15
A naked-eye paper sensor for rapid determination of trace mercury ion in water samples was designed and demonstrated. The mercury-sensing rhodamine B thiolactone was immobilized in silica matrices and the silica matrices were impregnated firmly and uniformly in the filter paper. As water samples flow through the filter paper, the membrane color will change from white to purple red, which could be observed obviously with naked eye, when concentration of mercury ions equals to or exceeds 10nM, the maximum residue level in drinking water recommended by U.S. EPA. The color change can also be recorded by a flatbed scanner and then digitized, reducing the detection limit of Hg(2+) down to 1.2 nM. Moreover, this method is extremely specific for Hg(2+) and shows a high tolerance ratio of interferent coexisting ions. The presence of Na(+) (2 mM), K(+) (2 mM), Fe(3+) (0.1 mM), Zn(2+) (0.1 mM), Mg(2+) (0.1 mM), Ni(2+) (50 μM), Co(2+) (50 μM), Cd(2+) (50 μM), Pb(2+) (50 μM), Cu(2+) (50 μM) and Ag(+) (3.5 μM) did not interfere with the detection of Hg(2+) (25 nM). Finally, the present method was applied in the detection of Hg(2+) in mineral water, tap water and pond water. Copyright © 2013 Elsevier B.V. All rights reserved.
Chemical substitution study on magnetism and superconductivity in Ce1-xSmxCoIn5
NASA Astrophysics Data System (ADS)
Jang, Sooyoung; White, B. D.; Yazici, D.; Wong, A. S.; Maple, M. B.
2015-03-01
We have investigated the system Ce1-xSmxCoIn5 (0 < x < 1) by means of x-ray diffraction, electrical resistivity, specific heat, and magnetization measurements. We observe a crossover from a coherent Kondo lattice exhibiting superconductivity to a single-ion impurity Kondo effect coexisting with magnetic order on the Sm-rich side of the phase diagram. The superconducting transition temperature, Tc, and Kondo lattice coherence temperature, Tcoh, are suppressed near x ~ 0.2 and x ~ 0.5, respectively, which is consistent with the effect of substitution with other rare-earth (RE) ions on CeCoIn5. After Tcoh is suppressed to 0 K, a single-ion impurity Kondo effect is observed for 0.5 < x <= 0.85. The compound SmCoIn5 exhibits three distinct magnetic phase transitions at roughly 8, 10, and 12 K, which are presumably associated with magnetic order; similar features are observed in the related compound SmIn3. These transition temperatures are gradually suppressed by Ce substitution and completely vanish near x ~ 0.2. We establish the phase diagram of the system Ce1-xSmxCoIn5 and compare our results with those obtained from chemical substitution studies of CeCoIn5 involving other RE ions. Research at UCSD was supported by the U.S. Department of Energy, Office of Basic Energy Science, Division of Material Science and Engineering under Grant No. DE-FG02-04-ER46105.
Lesseux, G. G.; Garitezi, T. M.; Rosa, P. F. S.; ...
2016-02-24
Electron spin resonance (ESR) of diluted Nd 3+ ions in the topologically nontrivial semimetallic (TNSM) YBiPt compound is reported. The cubic YBiPt compound is a non-centrosymmetric half Heusler material which crystallizes in the F43m space group. The low temperature Nd 3+ ESR spectra showed a g-value of 2.66(4) corresponding to amore » $${{\\Gamma}_{6}}$$ cubic crystal field Kramers' doublet ground state. Remarkably, the observed metallic and diffusive (Dysonian) Nd 3+ lineshape presented an unusual dependence with grain size, microwave power, Nd 3+ concentration and temperature. Furthermore, the spin dynamic of the localized Nd 3+ ions in YBiPt was found to be characteristic of a phonon-bottleneck regime. It is claimed that, in this regime for YBiPt, phonons are responsible for mediating the diffusion of the microwave energy absorbed at resonance by the Nd 3+ ions to the thermal bath throughout the skin depth ($$\\delta \\simeq 15$$ μm). We argue that this is only possible because of the existence of highly mobile conduction electrons inside the skin depth of YBiPt that are strongly coupled to the phonons by spin–orbit coupling. Thus, our unexpected ESR results point to a coexistence of metallic and insulating behaviors within the skin depth of YBiPt. This scenario is discussed in the light of the TNSM properties of this compound.« less
Formation of ion clusters in the phase separated structures of neutral-charged polymer blends
NASA Astrophysics Data System (ADS)
Kwon, Ha-Kyung; Olvera de La Cruz, Monica
2015-03-01
Polyelectrolyte blends, consisting of at least one charged species, are promising candidate materials for fuel cell membranes, for their mechanical stability and high selectivity for proton conduction. The phase behavior of the blends is important to understand, as this can significantly affect the performance of the device. The phase behavior is controlled by χN, the Flory-Huggins parameter multiplied by the number of mers, as well as the electrostatic interactions between the charged backbone and the counterions. It has recently been shown that local ionic correlations, incorporated via liquid state (LS) theory, enhance phase separation of the blend, even in the absence of polymer interactions. In this study, we show phase diagrams of neutral-charged polymer blends including ionic correlations via LS theory. In addition to enhanced phase separation at low χN, the blends show liquid-liquid phase separation at high electrostatic interaction strengths. Above the critical strength, the charged polymer phase separates into ion-rich and ion-poor regions, resulting in the formation of ion clusters within the charged polymer phase. This can be shown by the appearance of multiple spinodal and critical points, indicating the coexistence of several charge separated phases. This work was performed under the following financial assistance award 70NANB14H012 from U.S. Department of Commerce, National Institute of Standards and Technology as part of the Center for Hierarchical Materials Design (CHiMaD).
Tuberculous otitis media with endobronchial tuberculosis.
Hwang, Ki-Eun; Kim, So-Young; Chung, Jin-Soo; Lee, Sang-Heon; Choi, Keum-Ha; Park, Do-Sim; Park, Seong-Hoon; Jeong, Eun-Taik; Kim, Hak-Ryul
2012-12-01
Although tuberculosis can affect various organs and tissues, the lung is the site most commonly involved. Extrapulmonary tuberculosis (EPTB) involves relatively inaccessible and variable sites and is consequently often overlooked by clinicians. The ear is a notably very rare site of EPTB, and the diagnosis is difficult because of the variable and confusing signs and symptoms. To our knowledge, this is the first case in which tuberculous otitis media and endobronchial tuberculosis coexisted.
Robazzi, Teresa Cristina M V; Alves, Crésio; Abreu, Laís; Lemos, Gabriela
2015-01-01
To report a case of coexisting systemic lupus erythematosus (SLE) and sickle cell disease (SCD) with a review of the literature on the topic. Report of case and research of the association between SLE and SCD in literature through scientific articles in health sciences databases, such as LILACS, MEDLINE/Pubmed and Scielo, until May 2012. Descriptors used: 1. Sickle cell anemia; 2. Sickle cell disease; 3. Systemic lupus erythematosus; 4. Hemoglobinopathies. The authors describe an association between SLE and SS hemoglobinopathy in an eight-year-old female patient displaying articular, hematologic and neuropsychiatric manifestations during clinical evolution. Forty-five cases of association between SLE and SCD are described in literature, mostly adult (62.2%), women (78%) and with the SS phenotype in 78% of the cases, and different clinical manifestations. Compared with our patient, articular, hematologic and neuropsychiatric manifestations were present in 76%, 36% and 27% of the cases, respectively. SLE and SCD are chronic diseases that have several clinical and laboratory findings in common, meaning difficult diagnosis and difficulty in finding the correct treatment. Although the association between these diseases is not common, it is described in literature, so it is imperative that physicians who treat such diseases be alert to this possibility. Copyright © 2012 Elsevier Editora Ltda. All rights reserved.
Yavuz, D; Gündüz, A; Ertan, S; Apaydın, H; Şifoğlu, A; Kiziltan, G; Kiziltan, M E
2015-05-01
We aimed to analyze functional changes at brainstem and spinal levels in essential tremor (ET), Parkinson's disease (PD) and coexisting essential tremor and Parkinson's disease (ET-PD). Age- and gender-matched patients with tremor (15 ET, 7 ET with resting tremor, 25 ET-PD and 10 PD) and 12 healthy subjects were enrolled in the study. Diagnosis was established according to standardized clinical criteria. Electrophysiological studies included blink reflex (BR), auditory startle reaction (ASR) and long latency reflex (LLR). Blink reflex was normal and similar in all groups. Probability of ASR was significantly lower in ET-PD group whereas it was similar to healthy subjects in ET and PD (P<0.001). LLR was recorded during voluntary activity in all three groups. LLR II was more common in ET, PD and ET-PD groups. LLR III was far more common in the PD group (n=3, 13.6% in ET; n=4, 16.0% in ET-PD and n=7, 46.7% in PD; p=0.037). Despite the integrity of BR pathways, ASR and LLR show distinctive abnormalities in ET-PD. In our opinion, our electrophysiological findings support the hypothesis that ET-PD is a distinct entity. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
Coexistence of superconductivity and antiferromagnetism in (Li0.8Fe0.2)OHFeSe.
Lu, X F; Wang, N Z; Wu, H; Wu, Y P; Zhao, D; Zeng, X Z; Luo, X G; Wu, T; Bao, W; Zhang, G H; Huang, F Q; Huang, Q Z; Chen, X H
2015-03-01
Iron selenide superconductors exhibit a number of unique characteristics that are helpful for understanding the mechanism of superconductivity in high-Tc iron-based superconductors more generally. However, in the case of AxFe2Se2 (A = K, Rb, Cs), the presence of an intergrown antiferromagnetic insulating phase makes the study of the underlying physics problematic. Moreover, FeSe-based systems intercalated with alkali metal ions, NH3 molecules or organic molecules are extremely sensitive to air, which prevents the further investigation of their physical properties. It is therefore desirable to find a stable and easily accessible FeSe-based superconductor to study its physical properties in detail. Here, we report the synthesis of an air-stable material, (Li0.8Fe0.2)OHFeSe, which remains superconducting at temperatures up to ~40 K, by means of a novel hydrothermal method. The crystal structure is unambiguously determined by a combination of X-ray and neutron powder diffraction and nuclear magnetic resonance. Moreover, antiferromagnetic order is shown to coexist with superconductivity. This synthetic route opens a path for exploring superconductivity in other related systems, and confirms the appeal of iron selenides as a platform for understanding superconductivity in iron pnictides more broadly.
A Rare Case Report of a Child Coexistence Thyroglossal Cyst and Second Branchial Cleft Fistulae.
Mahdoufi, Rachid; Barhmi, Ismail; Tazi, Nabil; Rouadi, Sami; Abada, Reda; Roubal, Mohamed; Mahtar, Mohamed
2017-06-01
Thyroglossal duct cysts followed by branchial cleft anomalies are the most common congenital neck masses encountered in practice, second branchial cleft cysts and sinuses are the most common type (LaRiviere and Waldhausen in Surg Clin North Am 92(3):583-597, 2012). Although both abnormalities are common individually, but rarely seen associated in same patient as described in our case. Congenitalcervical anomalies are important to consider in the differential of head and neck masses in children and adults. These lesions can present as palpable cystic masses, infected masses, draining sinuses, or fistulae. Thyroglossal duct cysts are most common, followed by branchial cleft anomalies. A synchronous presentation of both type of cyst and fistula in a same child patient is very rare with no such cases reported in literature till date.
Ion toxicity and the development of a salinity toxicity relationship (STR) model for marine species
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tietge, J.E.; Mount, D.R.
1994-12-31
Salinity in effluents can cause acute toxicity to marine organisms. The toxicity of the water can be due to an excess or deficiency of common ions, which usually are not thought of as toxicants. In order to develop an understanding of this phenomenon, laboratory toxicity tests were conducted to determine the effects of single ion deficiency, single ion excess, multiple ion deficiency, multiple ion excess, and total salinity on survival of three common marine test organisms (Mysidopsis bahia, Cyprinidon variegatus, and Menidia beryllina). The ions which were manipulated in these studies were Na{sup +}, K{sup +}, Ca{sup ++}, Mg{sup ++},more » Sr{sup ++}, Cl{sup {minus}}, Br{sup {minus}}, SO{sub 4}{sup {minus}{minus}}, HCO{sub 3}{sup {minus}}, and B{sub 4}O{sub 7}{sup {minus}{minus}}. Results indicate that Ca{sup ++} and K{sup +} are essential ions at normal salinities, since the deficiency of these two ions causes mortality. In contrast, the complete deficiency of Mg{sup ++}, Sr{sup ++}, B{sub 4}O{sub 7}{sup {minus}{minus}}, and HCO{sub 3}{sup {minus}} did not affect survival. The single ion excess studies demonstrated that K{sup +}, Ca{sup ++}, Mg{sup ++}, and B{sub 4}O{sub 7}{sup {minus}} were acutely toxic in excess at normal salinities. Total salinity studies determined the salinity tolerance range for each species, with upper and lower LC{sub 50}s for Mysidopsis bahia at 44 g/L and 8 g/L, for Cyprinidon variegatus at 73 g/L and < 0 g/L, and for Menidia beryllina at 45 g/L and < 0 g/L. These data will be used to develop a model to predict toxicity due to common ions.« less
Ion charge state distribution effects on elastic X-ray Thomson scattering
NASA Astrophysics Data System (ADS)
Iglesias, Carlos A.
2018-03-01
Analytic models commonly applied in elastic X-ray Thomson scattering cross-section calculations are used to generate results from a discrete ion charge distribution and an average charge description. Comparisons show that interchanging the order of the averaging procedure can appreciably alter the cross-section, especially for plasmas with partially filled K-shell bound electrons. In addition, two common approximations to describe the free electron density around an ion are shown to yield significantly different elastic X-ray Thomson scattering cross-sections.
Mullick, Aditi; Neogi, Sudarsan
2018-07-01
Environmental concern associated with the side effects of high fluoride content in ground water and surface water has prompted the researchers to look for an efficient, convenient and easy method. Considering the potential of a good adsorbent, present study reports the synthesis of a composite by impregnating zirconium on powdered activated carbon (AC) using ultrasound as the tool for synthesis and applying it for fluoride adsorption from water. The nature of the composite was determined through characterization by scanning electron microscopy (SEM), energy dispersive Xray (EDX), Xray diffraction (XRD), N 2 adsorption analysis (BET) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. The pH pzc (point of zero charge) of the adsorbent was found to be 5.03; with the optimum pH obtained at 4 for adsorption of strong electronegative fluoride ions. The initial fluoride concentration was varied from 2.5 up to 20 mg.L -1 and the maximum adsorption capacity of 5 mg.g -1 was obtained. A maximum fluoride removal of 94.4% was obtained for an initial concentration of 2.5 mg.L -1 within an equilibrium time of 180 min. The adsorption isotherm followed the Langmuir isotherm model indicating a monolayer adsorption process and the adsorption kinetics followed pseudo second order model. The effects of various coexisting ions (HCO 3 - , NO 3 - , SO 4 2- , Cl - ) commonly present in the water were found to have negligible impact on the process performance. Conducting the adsorption-desorption studies for five consecutive cycles for an initial fluoride concentration of 10 mg.L -1 , the removal efficiency reduced from 86.2 to 32.6%. The ultrasonic method provided an easy route to synthesize the composite in less time and significantly reduced energy consumption by more than 96% compared to the conventional method. Copyright © 2018 Elsevier B.V. All rights reserved.
An efficient approach to integrated MeV ion imaging.
Nikbakht, T; Kakuee, O; Solé, V A; Vosuoghi, Y; Lamehi-Rachti, M
2018-03-01
An ionoluminescence (IL) spectral imaging system, besides the common MeV ion imaging facilities such as µ-PIXE and µ-RBS, is implemented at the Van de Graaff laboratory of Tehran. A versatile processing software is required to handle the large amount of data concurrently collected in µ-IL and common MeV ion imaging measurements through the respective methodologies. The open-source freeware PyMca, with image processing and multivariate analysis capabilities, is employed to simultaneously process common MeV ion imaging and µ-IL data. Herein, the program was adapted to support the OM_DAQ listmode data format. The appropriate performance of the µ-IL data acquisition system is confirmed through a case study. Moreover, the capabilities of the software for simultaneous analysis of µ-PIXE and µ-RBS experimental data are presented. Copyright © 2017 Elsevier B.V. All rights reserved.
Abbott, M.; Einerson, J.; Schuster, P.; Susong, D.; Taylor, Howard E.; ,
2004-01-01
Snow sampling and analysis methods which produce accurate and ultra-low measurements of trace elements and common ion concentration in southeastern Idaho snow, were developed. Snow samples were collected over two winters to assess trace elements and common ion concentrations in air pollutant fallout across the southeastern Idaho. The area apportionment of apportionment of fallout concentrations measured at downwind location were investigated using pattern recognition and multivariate statistical technical techniques. Results show a high level of contribution from phosphates processing facilities located outside Pocatello in the southern portion of the Eastern Snake River Plain, and no obvious source area profiles other than at Pocatello.
Chotirmall, S H; Low, T B; Hassan, T; Branagan, P; Kernekamp, C; Flynn, M G; Gunaratnam, C; McElvaney, N G
2011-06-01
Cystic fibrosis (CF) is of particular importance in Ireland as the Irish population has both the highest incidence (2.98/10,000) and the highest carrier rate (1 in 19) in the world. Primary immunodeficiency has not been previously reported as co-existing with CF. We report a unique case of CF associated with a primary immunodeficiency syndrome--common variable immunodeficiency (CVID). Our patient has CF, CVID and the additional comorbidity of Aspergers syndrome. The challenges inherent in diagnosing and treating such a case are outlined herein and the successful management of this case is evidenced by the well-preserved lung function of our patient.
Cobaltites: Emergence of magnetism and metallicity from a non-magnetic, insulating state
NASA Astrophysics Data System (ADS)
Phelan, Daniel Patrick
In cobalt oxides, the energy splitting between different spin-states of Co3+ ions can be quite small, which means that more than one spin-state can simultaneously co-exist in the same compound and that transitions between different spin-state can occur. This makes understanding the magnetic coupling between cobalt sites rather complex. Such is the case for pure and hole-doped LaCoO3. In its ground state, LaCoO3 is a non-magnetic insulator. The lack of a magnetic moment, is due to the fact that the ground spin-state of Co3+ ions is a low-spin, S=0, state. However, since a spin-state that has a net spin is on the order of 100 K higher in energy than the ground spin-state, a magnetic moment appears as the temperature is increased, and the system behaves as a paramagnet above 100 K. The higher-energy spin-state is either an intermediate-spin (S=1) state of a high-spin (S=2) state - an issue that has been debated for quite some time. When holes are chemically doped into the system, as in La1- xSrxCoO3 (LSCO), the non-magnetic, insulating ground state evolves into a ferromagnetic, metallic state. This evolution is complicated because it occurs due to the convoluted effects of Co4+ ions being doped into the system and the fact that the ground spin-state of Co3+ ions changes as a function of the hole concentration. In this dissertation, the magnetic transitions in pure and hole-doped LaCoO3 are investigated by neutron scattering techniques. In the pure compound, it is shown that thermally excited spins have both fluctuating ferromagnetic and antiferro-magnetic spin-correlations, which is suggested to result from a dynamic orbital ordering of the occupied e. g orbitals of the intermediate-spin state. It is also shown that the thermally excited spin-state is split in energy by 0.6 meV. In the hole-doped compound, LSCO, it is shown that the evolution into a metallic ferromagnet occurs by the percolation of isotropic ferromagnetic droplets. It is also shown that incommensurate spin-correlations co-exist and compete with ferromagnetic spin correlations in LSCO, and it is argued that this competition is manifested in the thermodynamic properties. The role of the lattice upon the magnetic transitions in the hole-doped compounds is addressed by simultaneous analysis of magnetic Bragg peaks, the local atomic structure, and the average crystal structure from powder neutron diffraction patterns of La1- xCaxCoO3 and La 1-xBaxCoO3. It is suggested that the fraction of ions with intermediate spin-states at a fixed hole concentration depends on the radius of the A-site dopant.
Fawzy, Manal; Nasr, Mahmoud; Nagy, Heba; Helmi, Shacker
2018-02-01
In this study, batch biosorption experiments were conducted to determine the removal efficiency of Cd(II) ion from aqueous solutions by Gossypium barbadense waste. The biosorbent was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) connected with energy dispersive X-ray (EDX). The sorption mechanism was described by complexation/chelation of Cd 2+ with the functional groups of O-H, C=O, -COO-, and C-O, as well as, cation-exchange with Mg 2+ and K + . At initial Cd(II) ion concentration (C o ), 50 mg/L, the adsorption equilibrium of 89.2% was achieved after 15 min under the optimum experimental factors of pH 6.0, biosorbent dosage 10 g/L, and particle diameter 0.125-0.25 mm. Both Langmuir and Freundlich models fitted well to the sorption data, suggesting the co-existence of monolayer coverage along with heterogenous surface biosorption. Artificial neural network (ANN) with a structure of 5-10-1 was performed to predict the Cd(II) ion removal efficiency. The ANN model provided high fit (R 2 0.923) to the experimental data and indicated that C o was the most influential input. A pure-quadratic model was developed to determine the effects of experimental factors on Cd(II) ion removal efficiency, which indicated the limiting nature of pH and biosorbent dosage on Cd(II) adsorption. Based on the regression model (R 2 0.873), the optimum experimental factors were pH 7.61, biosorbent dosage 24.74 g/L, particle size 0.125-0.25 mm, and adsorption time 109.77 min, achieving Cd 2+ removal of almost 100% at C o 50 mg/L.
Gao, Limin; Li, Huifang; Li, Gandi; Liu, Weiping; Li, Jinnan; Zhang, Wenyan
2015-01-01
We report an uncommon 22-year-old male Pulmonary Langerhans Cell Histiocytosis (PLCH) case which co-existed with pulmonary tuberculosis (TB). Unlike the common PLCH cases, this PLCH case has cervical lymph node involvement and right pneumothorax. The diagnosis was established by the imaging of lung and the biopsies of the lung and left neck lymph node. Imaging of the chest showed characteristic small nodules and thin-walled cysts and right pneumothorax. The LCH cells in the lung and left neck lymph node were characterized by large convoluted nuclei with cerebriform indentations of the nuclear envelope and longitudinal grooves. The nuclei contained small eosinophilic nucleoli and moderate amount cytoplasm. Immunohistochemically, the histiocytoid cells were positive for Langerin, CD1a and S-100. Acid-fast bacilli were found in sputum and lung biopsy tissue. To the best of our knowledge, this is the first case of PLCH with cervical lymph node involvement, and coexisted with pulmonary tuberculosis, right pneumothorax. A contribution of this case and review three of the five cases of PLCH with extrapulmonary involvement to lymph nodes resolved spontaneously after smoking cessation constitute a novel addition that it is inappropriate to regard pulmonary/nodal LCH as multi-organ or disseminated disease, and the treatment methods are the same whether the PLCH patient with lymph node involvement or not.
Treatment of coexistent psoriasis and lupus erythematosus.
Varada, Sowmya; Gottlieb, Alice B; Merola, Joseph F; Saraiya, Ami R; Tintle, Suzanne J
2015-02-01
The coexistence of psoriasis and lupus erythematosus (LE) is rare. Anecdotal evidence suggests that anti-tumor necrosis factor alfa (TNF-α) agents may be efficacious in LE, although their use is commonly avoided in this disease because of concern for lupus flare. We sought to describe the epidemiology, serologic findings, and therapeutic choices in patients with coexistent psoriasis/psoriatic arthritis and LE and to determine the risk of lupus flares with TNF-α inhibitors. We performed a retrospective multicenter study of patients given the diagnoses of psoriasis (or psoriatic arthritis) and lupus erythematosus (systemic LE or cutaneous LE, including either subacute cutaneous LE or discoid LE) at 2 academic tertiary-care centers. A total of 96 patients with a mean age of 56 years was included. We report higher-than-expected rates of white race and psoriatic arthritis. One clinical lupus flare was observed in a patient receiving a TNF-α inhibitor, resulting in an incidence of 0.92% lupus flares per patient-year of TNF-α inhibitor use. Retrospective chart review, small sample size, and limited documentation. Anti-TNF-α agents, ustekinumab, and abatacept may be valid treatment options for patients with concomitant LE and psoriasis. Clinical lupus flares in LE patients treated with TNF-α inhibitors were infrequent. Copyright © 2014 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.
Hu, Maohong; Li, Xiaodan; Ni, Xiansheng; Wu, Jingwen; Gao, Rongbao; Xia, Wen; Wang, Dayan; He, Fenglan; Chen, Shengen; Liu, Yangqing; Guo, Shuangli; Li, Hui; Shu, Yuelong; Bethel, Jeffrey W; Liu, Mingbin; Moore, Justin B; Chen, Haiying
2015-01-01
Infection with the novel H10N8 virus in humans has raised concerns about its pandemic potential worldwide. We report the results of a cross-sectional study of avian influenza viruses (AIVs) in live poultry markets (LPMs) in Nanchang, China, after the first human case of H10N8 virus infection was reported in the city. A total of 201 specimens tested positive for AIVs among 618 samples collected from 24 LPMs in Nanchang from December 2013 to January 2014. We found that the LPMs were heavily contaminated by AIVs, with H9, H10, and H5 being the predominant subtypes and more than half of the LPMs providing samples that were positive for the H10 subtype. Moreover, the coexistence of different subtypes was common in LPMs. Of the 201 positive samples, 20.9% (42/201) had mixed infections with AIVs of different HA subtypes. Of the 42 mixed infections, 50% (21/42) showed the coexistence of the H9 and H10 subtypes, with or without H5, and were from chicken samples. This indicated that the H10N8 virus probably originated from segment reassortment of the H9 and H10 subtypes.
Spin Crossover in Solid and Liquid (Mg,Fe)O at Extreme Conditions
NASA Astrophysics Data System (ADS)
Stixrude, L. P.; Holmstrom, E.
2016-12-01
Ferropericlase, (Mg,Fe)O, is a major constituent of the Earth's lowermantle (24-136 GPa). Understanding the properties of this component is importantnot only in the solid state, but also in the molten state, as theplanet almost certainly hosted an extensive magma ocean initiallyWith increasing pressure, the Fe ions in the material begin to collapse from a magnetic to a nonmagnetic spin state. This crossover affects thermodynamic, transport, and electrical properties.Using first-principles molecular dynamics simulations,thermodynamic integration, and adiabatic switching, we present a phasediagram of the spin crossover In both solid and liquid, we find a broad pressure range of coexisting magnetic and non-magnetic ions due to the favorable enthalpy of mixing of the two. In the solid increasingtemperature favors the high spin state, while in the liquid the oppositeoccurs, due to the higher electronic entropy of the low spin state. Becausethe physics of the crossover differ in solid and liquid, melting produces a large change in spin state that may affect the buoyancy of crystals freezing from the magma ocean in the earliest Earth.
Electron-acoustic solitary waves in dense quantum electron-ion plasmas
DOE Office of Scientific and Technical Information (OSTI.GOV)
Misra, A. P.; Shukla, P. K.; Bhowmik, C.
2007-08-15
A quantum hydrodynamic (QHD) model is used to investigate the propagation characteristics of nonlinear electron-acoustic solitary waves (EASWs) in a dense quantum plasma whose constituents are two groups of electrons: one inertial cold electrons and other inertialess hot electrons, and the stationary ions which form the neutralizing background. By using the standard reductive perturbation technique, a Kadomtsev-Petviashvili (KP) equation, which governs the dynamics of EASWs, is derived in both spherical and cylindrical geometry. The effects of cold electrons and the density correlations due to quantum fluctuations on the profiles of the amplitudes and widths of the solitary structures are examinedmore » numerically. The nondimensional parameter {delta}=n{sub c0}/n{sub h0}, which is the equilibrium density ratio of the cold to hot electron component, is shown to play a vital role in the formation of both bright and dark solitons. It is also found that the angular dependence of the physical quantities and the presence of cold electrons in a quantum plasma lead to the coexistence of some new interesting novel solitary structures quite distinctive from the classical ones.« less
Capacity improvement by deficit of transition metals in inverse spinel LiNi1/3Co1/3Mn1/3VO4 cathodes
NASA Astrophysics Data System (ADS)
Kitajou, Ayuko; Yoshida, Jun; Nakanishi, Shinji; Matsuda, Yasuaki; Kanno, Ryoji; Okajima, Toshihiro; Okada, Shigeto
2016-01-01
Although inverse spinel materials have attracted attention because of their unusually high voltage characteristics, their rechargeable capacities are generally less than 50 mAh g-1, as a result of the coexistence of Li and transition metal ions at 16d octahedral sites. This work attempted to improve cathode functioning by optimizing the quantities of Li and transition metal ions residing at the 16d sites of LiNi1/3Co1/3Mn1/3VO4. The rechargeable capacity of the LiNi0.28Co0.28Mn0.26V0.80O4 synthesized in the present study was found to be above 120 mAh g-1, representing the largest capacity reported to date for an inverse spinel material. The results of in-situ XANES analysis demonstrated that the charge-discharge reactions of LiNi1/3Co1/3Mn1/3VO4 corresponds to the Mn2+/Mn4+ and Co2+/Co3+ redox couples, mainly.
Evolution of competing magnetic order in the J eff=1/2 insulating state of Sr 2Ir 1-xRu xO 4
Calder, Stuart A.; Kim, Jong-Woo; Cao, Guixin; ...
2015-10-27
We investigate the magnetic properties of the series Sr 2Ir 1-xRu xO 4 with neutron, resonant x-ray and magnetization measurements. The results indicate an evolution and coexistence of magnetic structures via a spin flop transition from ab-plane to c-axis collinear order as the 5d Ir4 + ions are replaced with an increasing concentration of 4d Ru4 + ions. The magnetic structures within the ordered regime of the phase diagram (x<0.3) are reported. Despite the changes in magnetic structure no alteration of the J eff=1/2 ground state is observed. This behavior of Sr 2Ir 1-xRu xO 4 is consistent with electronicmore » phase separation and diverges from a standard scenario of hole doping. The role of lattice alterations with doping on the magnetic and insulating behavior is considered. Our results presented here provide insight into the magnetic insulating states in strong spin-orbit coupled materials and the role perturbations play in altering the behavior.« less
Why square lattices are not seen on curved ionic membranes
NASA Astrophysics Data System (ADS)
Thomas, Creighton; Olvera de La Cruz, Monica
2013-03-01
Ionic crystalline membranes on curved surfaces are ubiquitous in nature, appearing for example on the membranes of halophilic organisms. Even when these membranes buckle into polyhedra with square or rectangular sides, the crystalline structure is seen to have hexagonal symmetry. Here, we theoretically and numerically investigate the effects of curvature on square lattices. Our model system consists of both positive and negative ions with a 1:1 charge ratio adsorbed onto the surface of a sphere. In flat space, the lowest-energy configuration of this system can be a square lattice. This bipartite arrangement is favored because there are two types of ions. It leads to a fundamentally different defect structure than what has been seen when triangular lattices are favored. We classify these defects and find that curvature disrupts long-range square symmetry in a crystal. Through numerical simulations, we see that small square regions are possible in some cases, but this phase coexists with other structures, limiting the scale of these square-lattice microstructures. Thus, at large length scales, curvature leads to triangular structures.
Theoretical investigation of the magnetoelectric properties of Bi2NiTiO6
NASA Astrophysics Data System (ADS)
Patra, Lokanath; Ravindran, P.
2018-04-01
We report the first principle investigations on the structural, electronic, magnetic and ferroelectric properties of a Pb free double perovskite multiferroic Bi2NiTiO6 using density functional theory within the general gradient approximation (GGA) and GGA+U method. Our results show that Bi2NiTiO6 will be an insulator with G-type magnetic ordering in its ground state with Ni2+ in a high spin state and a spin moment of 1.741μB. The paraelectric phase stabilizes in nonmagnetic state with Ni2+ in low spin configuration showing that spin state transition plays an important role in strong magnetoelectric coupling in Bi2NiTiO6. The bonding characteristics of the constituents are analyzed with the help of partial density of states and Born effective charges. The presence of Ti ions at Ni sites suppresses the disproportionation observed in case of BiNiO3 and results in a noncentrosymmetric crystal structure. The coexistence of Bi 6s lone pair and Ti4+ d0 ions which brings covalency produces a polarization of 32 µCcm-2.
Liang, Zhijie; Shi, Wenxin; Zhao, Zhiwei; Sun, Tianyi; Cui, Fuyi
2017-06-15
The spherical mesoporous silica (meso-silica) MCM-41 and those with different dosage of the retained templates were prepared and characterized. Particularly, effects of the retained template and its dosage on the adsorption of typical heavy metals (Cu 2+ and Cd 2+ ) in the synthesized materials were investigated. The results indicated that the retained templates acted as "helpers" for the adsorption of Cu 2+ and Cd 2+ in the spherical meso-silica MCM-41, and the maximum adsorption capacities (Q max ) increased with the increase of the retained template dosage. The interaction between the metal ions and the cationic heads of the templates contributed to the enhancement effect due to the anions (Cl - and OH - ) electronically adsorbed on the interface of the template micelles. Additionally, the presented results indicated that the adsorption of Cu 2+ and Cd 2+ depended on pH and high ion strength of the solution but not on the coexisted humic acid. Copyright © 2017 Elsevier Inc. All rights reserved.
Tail reconnection in the global magnetospheric context: Vlasiator first results
NASA Astrophysics Data System (ADS)
Palmroth, Minna; Hoilijoki, Sanni; Juusola, Liisa; Pulkkinen, Tuija I.; Hietala, Heli; Pfau-Kempf, Yann; Ganse, Urs; von Alfthan, Sebastian; Vainio, Rami; Hesse, Michael
2017-11-01
The key dynamics of the magnetotail have been researched for decades and have been associated with either three-dimensional (3-D) plasma instabilities and/or magnetic reconnection. We apply a global hybrid-Vlasov code, Vlasiator, to simulate reconnection self-consistently in the ion kinetic scales in the noon-midnight meridional plane, including both dayside and nightside reconnection regions within the same simulation box. Our simulation represents a numerical experiment, which turns off the 3-D instabilities but models ion-scale reconnection physically accurately in 2-D. We demonstrate that many known tail dynamics are present in the simulation without a full description of 3-D instabilities or without the detailed description of the electrons. While multiple reconnection sites can coexist in the plasma sheet, one reconnection point can start a global reconfiguration process, in which magnetic field lines become detached and a plasmoid is released. As the simulation run features temporally steady solar wind input, this global reconfiguration is not associated with sudden changes in the solar wind. Further, we show that lobe density variations originating from dayside reconnection may play an important role in stabilising tail reconnection.
Markantoni, Vasiliki; Kouris, Anargyros; Armyra, Kalliopi; Vavouli, Charitomeni; Kontochristopoulos, George
2014-01-01
Dyshidrotic hand eczema is a common condition, which can be resistant to various treatments. Although a number of etiologic factors are involved in the pathogenesis of dyshidrotic eczema, hyperhidrosis is assumed to play a significant role. Oxybutynin is an alternative treatment for hyperhidrosis. We present the cases of two patients suffering from hyperhidrosis and dyshidrotic eczema, who were treated with oxybutynin with impressive results. © 2014 Wiley Periodicals, Inc.
Deylami, Mohammad N; Jovanov, Emil
2014-01-01
The overlap of transmission ranges between wireless networks as a result of mobility is referred to as dynamic coexistence. The interference caused by coexistence may significantly affect the performance of wireless body area networks (WBANs) where reliability is particularly critical for health monitoring applications. In this paper, we analytically study the effects of dynamic coexistence on the operation of IEEE 802.15.4-based health monitoring WBANs. The current IEEE 802.15.4 standard lacks mechanisms for effectively managing the coexistence of mobile WBANs. Considering the specific characteristics and requirements of health monitoring WBANs, we propose the dynamic coexistence management (DCM) mechanism to make IEEE 802.15.4-based WBANs able to detect and mitigate the harmful effects of coexistence. We assess the effectiveness of this scheme using extensive OPNET simulations. Our results indicate that DCM improves the successful transmission rates of dynamically coexisting WBANs by 20%-25% for typical medical monitoring applications.
Microfabricated linear Paul-Straubel ion trap
Mangan, Michael A [Albuquerque, NM; Blain, Matthew G [Albuquerque, NM; Tigges, Chris P [Albuquerque, NM; Linker, Kevin L [Albuquerque, NM
2011-04-19
An array of microfabricated linear Paul-Straubel ion traps can be used for mass spectrometric applications. Each ion trap comprises two parallel inner RF electrodes and two parallel outer DC control electrodes symmetric about a central trap axis and suspended over an opening in a substrate. Neighboring ion traps in the array can share a common outer DC control electrode. The ions confined transversely by an RF quadrupole electric field potential well on the ion trap axis. The array can trap a wide array of ions.
NASA Astrophysics Data System (ADS)
Wright, Matthew D.; Buckley, Alison J.; Matthews, James C.; Shallcross, Dudley E.; Henshaw, Denis L.
2014-10-01
Corona ions produced by high-voltage power lines (HVPLs) can alter the nearby electrical environment, potentially increasing aerosol charge levels downwind. However, there is a lack of knowledge concerning the concentration and mobility of ions from AC HVPLs and their dispersion away from the line. We present ion concentration and mobility measurements made near AC HVPLs in South-West England. Examples of typical mobility spectra are shown highlighting features commonly observed. Corona was observed during 33 of 46 measurements, at 9 of 11 sites, with positive or ‘bipolar' (both polarities) ion production commonly seen. Ion production usually increases atmospheric concentrations by only a modest amount, but extreme cases can enhance concentration by an order of magnitude or more. A polarity imbalance is required to increase aerosol charge via ion attachment; this was observed on 15 of 24 days when positive corona was observed, but was not seen for negative ions. Ion mobility was higher downwind compared with upwind for both ion polarities, but the increase was not statistically significant. Future work should focus on identifying and characterising ‘heavy-producing' HVPLs, and obtaining results in conditions which may favour negative ion production e.g. high humidity, inclement weather or during nighttime.
Common Orbital Infections ~ State of the Art ~ Part I
Hamed-Azzam, Shirin; AlHashash, Islam; Briscoe, Daniel; Rose, Geoffrey E; Verity, David H.
2018-01-01
Infections of the orbit and periorbita are relatively frequent, and can cause significant local and systemic morbidity. Loss of vision occurs in more than 10% of patients, and systemic sequelae can include meningitis, intracranial abscess, and death. Numerous organisms infect the orbit, but the most common are bacteria. There are many methods through which orbital infections occur, with infection from the neighboring ethmoid sinuses the most likely cause for all age groups. Prompt management is essential in suspected orbital cellulitis, and involves urgent intravenous antibiotics, rehydration, and treatment of any co-existent underlying systemic disease, e.g., diabetes, renal failure. This review summarizes the common infectious processes of the orbit in both pediatric and adult groups. We review pathophysiology, symptoms, signs, and treatment for infectious orbital processes. PMID:29719647
Review on heavy ion radiotherapy facilities and related ion sources (invited)a)
NASA Astrophysics Data System (ADS)
Kitagawa, A.; Fujita, T.; Muramatsu, M.; Biri, S.; Drentje, A. G.
2010-02-01
Heavy ion radiotherapy awakens worldwide interest recently. The clinical results obtained by the Heavy Ion Medical Accelerator in Chiba at the National Institute of Radiological Sciences in Japan have clearly demonstrated the advantages of carbon ion radiotherapy. Presently, there are four facilities for heavy ion radiotherapy in operation, and several new facilities are under construction or being planned. The most common requests for ion sources are a long lifetime and good stability and reproducibility. Sufficient intensity has been achieved by electron cyclotron resonance ion sources at the present facilities.
Martínez-García, Ricardo; Tarnita, Corina E
2017-08-07
The social amoeba Dictyostelium discoideum has been recently suggested as an example of bet-hedging in microbes. In the presence of resources, amoebae reproduce as unicellular organisms. Resource depletion, however, leads to a starvation phase in which the population splits between aggregators, which form a fruiting body made of a stalk and resistant spores, and non-aggregators, which remain as vegetative cells. Spores are favored when starvation periods are long, but vegetative cells can exploit resources in environments where food replenishes quickly. The investment in aggregators versus non-aggregators can therefore be understood as a bet-hedging strategy that evolves in response to stochastic starvation times. A genotype (or strategy) is defined by the balance between each type of cells. In this framework, if the ecological conditions on a patch are defined in terms of the mean starvation time (i.e. time between the onset of starvation and the arrival of a new food pulse), a single genotype dominates each environment, which is inconsistent with the huge genetic diversity observed in nature. Here we investigate whether seasonality, represented by a periodic, wet-dry alternation in the mean starvation times, allows the coexistence of several strategies in a single patch. We study this question in a non-spatial (well-mixed) setting in which different strains compete for a common pool of resources over a sequence of growth-starvation cycles. We find that seasonality induces a temporal storage effect that can promote the stable coexistence of multiple genotypes. Two conditions need to be met in our model. First, there has to be a temporal niche partitioning (two well-differentiated habitats within the year), which requires not only different mean starvation times between seasons but also low variance within each season. Second, each season's well-adapted strain has to grow and create a large enough population that permits its survival during the subsequent unfavorable season, which requires the number of growth-starvation cycles within each season to be sufficiently large. These conditions allow the coexistence of two bet-hedging strategies. Additional tradeoffs among life-history traits can expand the range of coexistence and increase the number of coexisting strategies, contributing toward explaining the genetic diversity observed in D. discoideum. Although focused on this cellular slime mold, our results are general and may be easily extended to other microbes. Copyright © 2017 Elsevier Ltd. All rights reserved.
Observations of Ion Diffusion Regions in the Geomagnetic Tail
NASA Astrophysics Data System (ADS)
Rogers, A. J.; Farrugia, C. J.; Torbert, R. B.; Argall, M. R.; Strangeway, R. J.; Ergun, R.
2017-12-01
We present analysis of two Ion Diffusion Regions (IDRs) in the geomagnetic tail, as observed by the Magnetospheric Multiscale Mission (MMS). Analysis of each event is centered around discussion of parameters commonly associated with IDRs such as enhanced electric field magnitude, guiding center expansion parameter, and ion velocity. Characteristic values for these parameters are determined, as well as other common attributes of IDRs, and used to develop a searching algorithm to automate identification of possible IDRs for closer inspection. Preliminary results of applying this algorithm to in situ MMS observations are also presented
A high-density association screen of 155 ion transport genes for involvement with common migraine
Nyholt, Dale R.; LaForge, K. Steven; Kallela, Mikko; Alakurtti, Kirsi; Anttila, Verneri; Färkkilä, Markus; Hämaläinen, Eija; Kaprio, Jaakko; Kaunisto, Mari A.; Heath, Andrew C.; Montgomery, Grant W.; Göbel, Hartmut; Todt, Unda; Ferrari, Michel D.; Launer, Lenore J.; Frants, Rune R.; Terwindt, Gisela M.; de Vries, Boukje; Verschuren, W.M. Monique; Brand, Jan; Freilinger, Tobias; Pfaffenrath, Volker; Straube, Andreas; Ballinger, Dennis G.; Zhan, Yiping; Daly, Mark J.; Cox, David R.; Dichgans, Martin; van den Maagdenberg, Arn M.J.M.; Kubisch, Christian; Martin, Nicholas G.; Wessman, Maija; Peltonen, Leena; Palotie, Aarno
2008-01-01
The clinical overlap between monogenic Familial Hemiplegic Migraine (FHM) and common migraine subtypes, and the fact that all three FHM genes are involved in the transport of ions, suggest that ion transport genes may underlie susceptibility to common forms of migraine. To test this leading hypothesis, we examined common variation in 155 ion transport genes using 5257 single nucleotide polymorphisms (SNPs) in a Finnish sample of 841 unrelated migraine with aura cases and 884 unrelated non-migraine controls. The top signals were then tested for replication in four independent migraine case–control samples from the Netherlands, Germany and Australia, totalling 2835 unrelated migraine cases and 2740 unrelated controls. SNPs within 12 genes (KCNB2, KCNQ3, CLIC5, ATP2C2, CACNA1E, CACNB2, KCNE2, KCNK12, KCNK2, KCNS3, SCN5A and SCN9A) with promising nominal association (0.00041 < P < 0.005) in the Finnish sample were selected for replication. Although no variant remained significant after adjusting for multiple testing nor produced consistent evidence for association across all cohorts, a significant epistatic interaction between KCNB2 SNP rs1431656 (chromosome 8q13.3) and CACNB2 SNP rs7076100 (chromosome 10p12.33) (pointwise P = 0.00002; global P = 0.02) was observed in the Finnish case–control sample. We conclude that common variants of moderate effect size in ion transport genes do not play a major role in susceptibility to common migraine within these European populations, although there is some evidence for epistatic interaction between potassium and calcium channel genes, KCNB2 and CACNB2. Multiple rare variants or trans-regulatory elements of these genes are not ruled out. PMID:18676988
ERIC Educational Resources Information Center
Danen, Wayne C.; Blecha, M. Therese, Sr.
1982-01-01
Background information and experimental procedures are provided for three lecture-demonstrations (involving hydrolysis of tetra-butyl chloride) illustrating: (1) common-ion or mass law effect; (2) effect of changing ionizing power of a solvent on a solvolysis reaction; and (3) collecting/plotting data to illustrate a first-order reaction.…
Hickam's dictum: Myasthenia Gravis presenting concurrently with Graves' disease.
Sehgal, Shekhar; Rebello, Roshan; Wolmarans, Louise; Elston, Marianne
2017-09-07
We present two patients with Graves' disease and concurrent myasthenia gravis. The impact of the dual diagnosis on the clinical course and the potential for a delayed diagnosis of myasthenia gravis is discussed. Patient 1, a 28-year-old man was diagnosed with Graves' disease following his second respiratory arrest. His history was strongly suggestive of a second pathology. Patient 2, a 66-year-old Cantonese woman with established Graves' disease presented with thionamide-related neutropaenia. Examination revealed bilateral ptosis and right lateral rectus palsy. Both patients had thyrotoxicosis secondary to Graves' disease with concurrent myasthenia gravis. Although neuromuscular weakness is common in Graves' disease, coexisting myasthenia gravis (MG) is rare and can cause profound morbidity. Ocular signs in both diseases may cause diagnostic confusion although ptosis suggests coexisting MG. In both cases, the thyrotoxicosis delayed the diagnosis of MG. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Artificial two-dimensional polar metal at room temperature.
Cao, Yanwei; Wang, Zhen; Park, Se Young; Yuan, Yakun; Liu, Xiaoran; Nikitin, Sergey M; Akamatsu, Hirofumi; Kareev, M; Middey, S; Meyers, D; Thompson, P; Ryan, P J; Shafer, Padraic; N'Diaye, A; Arenholz, E; Gopalan, Venkatraman; Zhu, Yimei; Rabe, Karin M; Chakhalian, J
2018-04-18
Polar metals, commonly defined by the coexistence of polar crystal structure and metallicity, are thought to be scarce because the long-range electrostatic fields favoring the polar structure are expected to be fully screened by the conduction electrons of a metal. Moreover, reducing from three to two dimensions, it remains an open question whether a polar metal can exist. Here we report on the realization of a room temperature two-dimensional polar metal of the B-site type in tri-color (tri-layer) superlattices BaTiO 3 /SrTiO 3 /LaTiO 3 . A combination of atomic resolution scanning transmission electron microscopy with electron energy-loss spectroscopy, optical second harmonic generation, electrical transport, and first-principles calculations have revealed the microscopic mechanisms of periodic electric polarization, charge distribution, and orbital symmetry. Our results provide a route to creating all-oxide artificial non-centrosymmetric quasi-two-dimensional metals with exotic quantum states including coexisting ferroelectric, ferromagnetic, and superconducting phases.
Sutherland, Greg T; Sheedy, Donna; Kril, Jillian J
2014-01-01
Chronic alcohol consumption results in structural changes to the brain. In alcoholics without coexisting thiamine deficiency or liver disease this is largely restricted to a loss of white-matter volume. When it occurs, neuronal loss is limited in anatomic distribution and only detected with quantitative techniques. This relative paucity of neurodegeneration is reflected in studies of gene and protein expression in postmortem brain where findings are subtle and discordant between studies. In alcoholics with coexisting pathologies, neuronal loss is more marked and affects a wider range of anatomic regions, especially subcortical nuclei. Although this more widespread damage may reflect a more severe drinking history, there is evidence linking thiamine deficiency and the consequences of liver disease to the pathogenesis of alcohol-related brain damage. Furthermore, a range of other factors, such as cigarette smoking and mood disorders, that are common in alcoholics, have the potential to influence studies of brain pathology and should be considered in further studies of the neuropathology of alcoholism. © 2014 Elsevier B.V. All rights reserved.
A Rare Case of Myxedema Coma with Neuroleptic Malignant Syndrome (NMS).
Dixit, Siddharth; Dutta, Manoj Kumar; Namdeo, Mayank
2015-05-01
Myxedema coma or hypothyroid crisis is an endocrine emergency and needs ICU management. Neuroleptic malignant syndrome (NMS) is another medical emergency which needs high degree of clinical suspicion else mortality can be high. There is a paradox in co existence of myxedema coma and NMS. While one is hypometabolic state another is hypermetabolic state and both can be precipitated by antipsychotics use. Hypothermia and flaccidity commonly expected in myxedema coma may mask fever and rigidity of classical NMS contributing to diagnostic problem and treatment delay. Scientific literature on coexistance of myxedema coma and NMS is sparse. We hereby report first case with coexisting myxedema coma and NMS in a patient of schizophrenia treated with antipsychotic, where classical symptoms of NMS were masked by myxedema coma. Prompt diagnosis and effective management by a team resulted in favourable outcome in our patient. This case is reported to alert intensive care physicians to atypical manifestations of NMS in presence of hypothyroidism.
A Rare Case of Myxedema Coma with Neuroleptic Malignant Syndrome (NMS)
Dutta, Manoj Kumar; Namdeo, Mayank
2015-01-01
Myxedema coma or hypothyroid crisis is an endocrine emergency and needs ICU management. Neuroleptic malignant syndrome (NMS) is another medical emergency which needs high degree of clinical suspicion else mortality can be high. There is a paradox in co existence of myxedema coma and NMS. While one is hypometabolic state another is hypermetabolic state and both can be precipitated by antipsychotics use. Hypothermia and flaccidity commonly expected in myxedema coma may mask fever and rigidity of classical NMS contributing to diagnostic problem and treatment delay. Scientific literature on coexistance of myxedema coma and NMS is sparse. We hereby report first case with coexisting myxedema coma and NMS in a patient of schizophrenia treated with antipsychotic, where classical symptoms of NMS were masked by myxedema coma. Prompt diagnosis and effective management by a team resulted in favourable outcome in our patient. This case is reported to alert intensive care physicians to atypical manifestations of NMS in presence of hypothyroidism. PMID:26155541
Kaczorowska, Ewa; Zimowski, Janusz; Cichoń-Kotek, Monika; Mrozińska, Agnieszka; Purzycka, Joanna; Wierzba, Jolanta; Limon, Janusz; Lipska-Ziętkiewicz, Beata S
Turner syndrome is a relatively common chromosomal disorder which affects about one in 2000 live born females. Duchenne muscular dystrophy is an X-linked recessive disorder affecting 1:3600 live born males. Considering the above, the coexistence of these two diseases may occur only anecdotally. Here, we report a 4 ½ year-old female with classical 45,X Turner syndrome who also had Duchenne muscular dystrophy caused by a point mutation in the dystrophin gene (c.9055delG). The patient showed the typical phenotype of Turner syndrome including distinctive dysmorphic features (short neck, low posterior hairline, wide position of nipples), aortic coarctation and feet lymphedema. Besides, she presented with an unusually early beginning of muscular dystrophy symptoms with infantile-onset motor developmental delay, intellectual disability and early calf muscular hypertrophy. The coexistence of an X-linked recessive disorder should be considered in women affected by Turner syndrome presenting with additional atypical clinical features.
Artificial two-dimensional polar metal at room temperature
Cao, Yanwei; Wang, Zhen; Park, Se Young; ...
2018-04-18
Polar metals, commonly defined by the coexistence of polar crystal structure and metallicity, are thought to be scarce because the long-range electrostatic fields favoring the polar structure are expected to be fully screened by the conduction electrons of a metal. Moreover, reducing from three to two dimensions, it remains an open question whether a polar metal can exist. Here we report on the realization of a room temperature two-dimensional polar metal of the B-site type in tri-color (tri-layer) superlattices BaTiO 3/SrTiO 3/LaTiO 3. A combination of atomic resolution scanning transmission electron microscopy with electron energy-loss spectroscopy, optical second harmonic generation,more » electrical transport, and first-principles calculations have revealed the microscopic mechanisms of periodic electric polarization, charge distribution, and orbital symmetry. Lastly, our results provide a route to creating all-oxide artificial non-centrosymmetric quasi-two-dimensional metals with exotic quantum states including coexisting ferroelectric, ferromagnetic, and superconducting phases.« less
Artificial two-dimensional polar metal at room temperature
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cao, Yanwei; Wang, Zhen; Park, Se Young
Polar metals, commonly defined by the coexistence of polar crystal structure and metallicity, are thought to be scarce because the long-range electrostatic fields favoring the polar structure are expected to be fully screened by the conduction electrons of a metal. Moreover, reducing from three to two dimensions, it remains an open question whether a polar metal can exist. Here we report on the realization of a room temperature two-dimensional polar metal of the B-site type in tri-color (tri-layer) superlattices BaTiO 3/SrTiO 3/LaTiO 3. A combination of atomic resolution scanning transmission electron microscopy with electron energy-loss spectroscopy, optical second harmonic generation,more » electrical transport, and first-principles calculations have revealed the microscopic mechanisms of periodic electric polarization, charge distribution, and orbital symmetry. Lastly, our results provide a route to creating all-oxide artificial non-centrosymmetric quasi-two-dimensional metals with exotic quantum states including coexisting ferroelectric, ferromagnetic, and superconducting phases.« less
Zargar, Showkat A; Mushtaq, Mosin; Beg, Mashkoor A; Javaid, Gul; Khan, Bashir A; Hassan, Rayhana; Kasana, Reyaz A; Tabassum, Sameena
2014-03-01
Endoscopic sphincterotomy (ES) is one of the most important advances in the treatment of common bile duct (CBD) stones. However, the use of ES to remove CBD stones in high-risk patients without cholecystectomy is still debatable. The aim of this study was to compare the efficacy of a wait-and-see policy versus cholecystectomy after ES for CBD stones in high-risk patients with co-existing cholelithiasis. A total of 162 patients after undergoing ES with the clearance of CBD stones were randomised after informed consent to cholecystectomy or conservative management of their gallbladder stones. The results indicated that cholecystectomy after ES for CBD stones significantly reduced the biliary complications in high-risk patients. Every patient who has both CBD stones and gallstones with significant co-morbid illnesses, after clearance of CBD stones by ES, should undergo early cholecystectomy. Copyright © 2014 Arab Journal of Gastroenterology. Published by Elsevier Ltd. All rights reserved.
Chorazy, Szymon; Charytanowicz, Tomasz; Wang, Junhao; Ohkoshi, Shin-Ichi; Sieklucka, Barbara
2018-05-29
A near-infrared emissive and magnetically anisotropic Nd(iii) complex is formed within a hybrid organic-inorganic {[NdIII(pzdo)(H2O)4][CoIII(CN)6]}·0.5(pzdo)·4H2O (1) (pzdo = pyrazine-N,N'-dioxide) ladder chain built of coexisting Nd-pzdo-Nd and Nd-NC-Co molecular bridges. 1 reveals two NdIII-centered properties, a field-induced slow magnetic relaxation of a single-ion origin with a thermal energy barrier of ΔE/kB = 51(2) K at Hdc = 1 kOe, and a near-infrared fluorescence sensitized by organic and inorganic linkers.
Fujimori, Keiichi; Sakata, Yuta; Moriuchi-Kawakami, Takayo; Shibutani, Yasuhiko
2017-11-01
A new sensitized chemiluminescence method by acidic permanganate oxidation was developed for the sensitive determination of trazodone. A fluorescent dye as used rhodamine 6G to increase a chemiluminescence intensity. Under optimum conditions, the liner range of the calibration curve was obtained for 1-5000 nmol/L. The limit of detection was calculated from 3σ of a blank was 0.23 nmol/L. The coexistent ions and substances had no interference with the chemiluminescence measurement. The chemiluminescence spectra were measured to elucidate a possible mechanism for the system. The present method was satisfactorily used in the determination of the drugs in pharmaceutical samples and animal serums. Copyright © 2017 John Wiley & Sons, Ltd.
Observation of Resonant Quantum Magnetoelectric Effect in a Multiferroic Metal-Organic Framework.
Tian, Ying; Shen, Shipeng; Cong, Junzhuang; Yan, Liqin; Wang, Shouguo; Sun, Young
2016-01-27
A resonant quantum magnetoelectric coupling effect has been demonstrated in the multiferroic metal-organic framework of [(CH3)2NH2]Fe(HCOO)3. This material shows a coexistence of a spin-canted antiferromagnetic order and ferroelectricity as well as clear magnetoelectric coupling below TN ≈ 19 K. In addition, a component of single-ion quantum magnets develops below ∼ 8 K because of an intrinsic magnetic phase separation. The stair-shaped magnetic hysteresis loop at 2 K signals resonant quantum tunneling of magnetization. Meanwhile, the magnetic field dependence of dielectric permittivity exhibits sharp peaks just at the critical tunneling fields, evidencing the occurrence of resonant quantum magnetoelectric coupling effect. This resonant effect enables a simple electrical detection of quantum tunneling of magnetization.
Varying Eu2+ magnetic order by chemical pressure in EuFe2(As1-xPx)2
NASA Astrophysics Data System (ADS)
Zapf, S.; Wu, D.; Bogani, L.; Jeevan, H. S.; Gegenwart, P.; Dressel, M.
2011-10-01
Based on low-field magnetization measurements on a series of single crystals, we present a scheme of the Eu2+ spin alignment in EuFe2(As1-xPx)2. We explain observations of the Eu2+ ordering previously reported, reconciling different existing phase diagrams. The magnetic moments of the Eu2+ ions are slightly canted, yielding a ferromagnetic contribution along the c direction that becomes stronger with pressure, until superconductivity sets in. The spin-density wave as well as the superconducting phase coexist with an antiferromagnetic interlayer coupling of the canted spins. Reducing the interlayer distance finally leads to a ferromagnetic Eu2+ interlayer coupling and to the suppression of superconductivity.
Yang, Rui; Wang, Wen-Xu; Lai, Ying-Cheng; Grebogi, Celso
2010-06-01
Evolutionary-game based models of nonhierarchical, cyclically competing populations have become paradigmatic for addressing the fundamental problem of species coexistence in spatially extended ecosystems. We study the role of intraspecific competition in the coexistence and find that the competition can strongly promote the coexistence for high individual mobility in the sense that stable coexistence can arise in parameter regime where extinction would occur without the competition. The critical value of the competition rate beyond which the coexistence is induced is found to be independent of the mobility. We derive a theoretical model based on nonlinear partial differential equations to predict the critical competition rate and the boundaries between the coexistence and extinction regions in a relevant parameter space. We also investigate pattern formation and well-mixed spatiotemporal population dynamics to gain further insights into our findings. (c) 2010 American Institute of Physics.
Overhead Projector Demonstrations.
ERIC Educational Resources Information Center
Kolb, Doris, Ed.
1988-01-01
Provides two demonstrations: (1) electrolyte migration of ions using colored ions which cross a strip of gelatin allowing for noticeable migration; and (2) photochemical reduction of Fe+3 by the citrate ion. Points out both reactions can be done in a Petri dish using common lab materials. (MVL)
Pollinator Foraging Adaptation and Coexistence of Competing Plants.
Revilla, Tomás A; Křivan, Vlastimil
2016-01-01
We use the optimal foraging theory to study coexistence between two plant species and a generalist pollinator. We compare conditions for plant coexistence for non-adaptive vs. adaptive pollinators that adjust their foraging strategy to maximize fitness. When pollinators have fixed preferences, we show that plant coexistence typically requires both weak competition between plants for resources (e.g., space or nutrients) and pollinator preferences that are not too biased in favour of either plant. We also show how plant coexistence is promoted by indirect facilitation via the pollinator. When pollinators are adaptive foragers, pollinator's diet maximizes pollinator's fitness measured as the per capita population growth rate. Simulations show that this has two conflicting consequences for plant coexistence. On the one hand, when competition between pollinators is weak, adaptation favours pollinator specialization on the more profitable plant which increases asymmetries in plant competition and makes their coexistence less likely. On the other hand, when competition between pollinators is strong, adaptation promotes generalism, which facilitates plant coexistence. In addition, adaptive foraging allows pollinators to survive sudden loss of the preferred plant host, thus preventing further collapse of the entire community.
A Study on Coexistence Capability Evaluations of the Enhanced Channel Hopping Mechanism in WBANs
Wei, Zhongcheng; Sun, Yongmei; Ji, Yuefeng
2017-01-01
As an important coexistence technology, channel hopping can reduce the interference among Wireless Body Area Networks (WBANs). However, it simultaneously brings some issues, such as energy waste, long latency and communication interruptions, etc. In this paper, we propose an enhanced channel hopping mechanism that allows multiple WBANs coexisted in the same channel. In order to evaluate the coexistence performance, some critical metrics are designed to reflect the possibility of channel conflict. Furthermore, by taking the queuing and non-queuing behaviors into consideration, we present a set of analysis approaches to evaluate the coexistence capability. On the one hand, we present both service-dependent and service-independent analysis models to estimate the number of coexisting WBANs. On the other hand, based on the uniform distribution assumption and the additive property of Possion-stream, we put forward two approximate methods to compute the number of occupied channels. Extensive simulation results demonstrate that our estimation approaches can provide an effective solution for coexistence capability estimation. Moreover, the enhanced channel hopping mechanism can significantly improve the coexistence capability and support a larger arrival rate of WBANs. PMID:28098818
Nonequilibrium 2-Hydroxyoctadecanoic Acid Monolayers: Effect of Electrolytes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lendrum, Conrad D.; Ingham, Bridget; Lin, Binhua
2012-02-06
2-Hydroxyacids display complex monolayer phase behavior due to the additional hydrogen bonding afforded by the presence of the second hydroxy group. The placement of this group at the position {alpha} to the carboxylic acid functionality also introduces the possibility of chelation, a utility important in crystallization including biomineralization. Biomineralization, like many biological processes, is inherently a nonequilibrium process. The nonequilibrium monolayer phase behavior of 2-hydroxyoctadecanoic acid was investigated on each of pure water, calcium chloride, sodium bicarbonate and calcium carbonate crystallizing subphases as a precursor study to a model calcium carbonate biomineralizing system, each at a pH of {approx}6. Themore » role of the bicarbonate co-ion in manipulating the monolayer structure was determined by comparison with monolayer phase behavior on a sodium chloride subphase. Monolayer phase behavior was probed using surface pressure/area isotherms, surface potential, Brewster angle microscopy, and synchrotron-based grazing incidence X-ray diffraction and X-ray reflectivity. Complex phase behavior was observed for all but the sodium chloride subphase with hydrogen bonding, electrostatic and steric effects defining the symmetry of the monolayer. On a pure water subphase hydrogen bonding dominates with three phases coexisting at low pressures. Introduction of calcium ions into the aqueous subphase ensures strong cation binding to the surfactant head groups through chelation. The monolayer becomes very unstable in the presence of bicarbonate ions within the subphase due to short-range hydrogen bonding interactions between the monolayer and bicarbonate ions facilitated by the sodium cation enhancing surfactant solubility. The combined effects of electrostatics and hydrogen bonding are observed on the calcium carbonate crystallizing subphase.« less
López, Abraham; Vilaseca, Marta; Madurga, Sergio; Varese, Monica; Tarragó, Teresa; Giralt, Ernest
2016-07-01
Ion mobility mass spectrometry (IMMS) is a biophysical technique that allows the separation of isobaric species on the basis of their size and shape. The high separation capacity, sensitivity and relatively fast time scale measurements confer IMMS great potential for the study of proteins in slow (µs-ms) conformational equilibrium in solution. However, the use of this technique for examining dynamic proteins is still not generalized. One of the major limitations is the instability of protein ions in the gas phase, which raises the question as to what extent the structures detected reflect those in solution. Here, we addressed this issue by analyzing the conformational landscape of prolyl oligopeptidase (POP) - a model of a large dynamic enzyme in the µs-ms range - by native IMMS and compared the results obtained in the gas phase with those obtained in solution. In order to interpret the experimental results, we used theoretical simulations. In addition, the stability of POP gaseous ions was explored by charge reduction and collision-induced unfolding experiments. Our experiments disclosed two species of POP in the gas phase, which correlated well with the open and closed conformations in equilibrium in solution; moreover, a gas-phase collapsed form of POP was also detected. Therefore, our findings not only support the potential of IMMS for the study of multiple co-existing conformations of large proteins in slow dynamic equilibrium in solution but also stress the need for careful data analysis to avoid artifacts. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
NASA Astrophysics Data System (ADS)
Baruah, Upama; Chowdhury, Devasish
2016-04-01
Functionalized graphene oxide quantum dots (GOQDs)-poly(vinyl alcohol) (PVA) hybrid hydrogels were prepared using a simple, facile and cost-effective strategy. GOQDs bearing different surface functional groups were introduced as the cross-linking agent into the PVA matrix thereby resulting in gelation. The four different types of hybrid hydrogels were prepared using graphene oxide, reduced graphene oxide, ester functionalized graphene oxide and amine functionalized GOQDs as cross-linking agents. It was observed that the hybrid hydrogel prepared with amine functionalized GOQDs was the most stable. The potential applicability of using this solid sensing platform has been subsequently explored in an easy, simple, effective and sensitive method for optical detection of M2+ (Fe2+, Co2+ and Cu2+) in aqueous media involving colorimetric detection. Amine functionalized GOQDs-PVA hybrid hydrogel when put into the corresponding solution of Fe2+, Co2+ and Cu2+ renders brown, orange and blue coloration respectively of the solution detecting the presence of Fe2+, Co2+ and Cu2+ ions in the solution. The minimum detection limit observed was 1 × 10-7 M using UV-visible spectroscopy. Further, the applicability of the sensing material was also tested for a mixture of co-existing ions in solution to demonstrate the practical applicability of the system. Insight into the probable mechanistic pathway involved in the detection process is also being discussed.
Reuse of organobentonites with a carbon dioxide responsive solvent.
Luan, Ling-Yu; Zhang, Li; Wang, Li-Hong
2018-05-22
Synthesized organobentonite (SOB), montmorillonite (MMT), and commercial organobentonite (COB) were used as adsorbents for paraffin oil, a model pollutant in land-based oil spills and oil pipeline rupture. The characterization of clays was carried out with scanning electron microscopy (SEM), thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). After adsorption, oil was separated from adsorbents with a carbon dioxide responsive solvent N,N-dimethylcyclohexylamine (DMCHA), and DMCHA was subsequently separated from paraffin oil upon CO 2 bubbling instead of distillation with high energy cost. The adsorption capacity of oil to SOB, MMT, and COB was 0.686, 1.124, and 1.239 g/g, respectively. It was found that the adsorption capacity and rinsed amount of the adsorbents depended on the d-spacing, which is related to surfactant content. Electrical conductivity and pH measurements suggested that the separation process occurred via two steps. Firstly, during the initial 35 min, carbonate ions coexisted with bicarbonate ions. Then, only bicarbonate ions existed after the introduction of CO 2 gas for 120 min. Thus, organobentonites were feasible for hydrocarbon adsorption and could be simply reused by an amine-based responsive solvent. This work provided a cost-effective and sustainable method of recycling of organobentonites and the responsive solvent, which can be used to deal with leaked oil and oil spills.
NASA Astrophysics Data System (ADS)
Zulfiqar Ali Ahamed, Sd.; Madhukar Reddy, C.; Deva Prasad Raju, B.
2013-05-01
Lead containing barium zinc lithium fluoroborate (LBZLFB) glasses doped with different concentrations of trivalent dysprosium ions were synthesized by conventional melt quenching method and characterized through the XRD, DSC, FTIR, FT-Raman, optical absorption, photoluminescence and decay curve analysis. X-ray diffraction studies revealed amorphous nature of the studied glass matrices. The thermal behavior has been reported by recording DSC thermograms. Coexistence of trigonal BO3 and tetrahedral BO4 units was evidenced by IR and Raman spectroscopy. Judd-Ofelt intensity parameters have been evaluated for 1.0 mol% Dy3+ ions doped LBZLFB glass. The measuring branching ratios are reasonably high for transitions 4F9/2 → 6H15/2 and 6H13/2 suggesting that the emission at 486 and 577 nm, respectively can give rise to lasing action in the visible region. From the visible emission spectra, the yellow to blue (Y/B) intensity ratios and chromaticity color coordinates were estimated. A combination of blue and yellow emissions has emerged in the glasses, which allows the observation of white light when the glasses are excited by the ultraviolet/blue light. These Dy3+ doped glasses are studied for their utility for white light generation under 454 nm excitation and the present LBZLFB glass is more suitable for generation of white light for blue LED chips.
Capacitive deionization of arsenic-contaminated groundwater in a single-pass mode.
Fan, Chen-Shiuan; Liou, Sofia Ya Hsuan; Hou, Chia-Hung
2017-10-01
A single-pass-mode capacitive deionization (CDI) reactor was used to remove arsenic from groundwater in the presence of multiple ions. The CDI reactor involved an applied voltage of 1.2 V and six cell pairs of activated carbon electrodes, each of which was 20 × 30 cm 2 . The results indicate that this method achieved an effluent arsenic concentration of 0.03 mg L -1 , which is lower than the arsenic concentration standard for drinking water and irrigation sources in Taiwan, during the charging stage. Additionally, the ability of the CDI to remove other coexisting ions was studied. The presence of other ions has a significant influence on the removal of arsenic from groundwater. From the analysis of the electrosorption selectivity, the preference for anion removal could be ordered as follows: NO 3 - > SO 4 2- > F - > Cl - >As. The electrosorption selectivity for cations could be ordered as follows: Ca 2+ > Mg 2+ > Na + ∼ K + . Moreover, monovalent cations can be replaced by divalent cations at the electrode surface in the later period of the electrosorption stage. Consequently, activated carbon-based capacitive deionization is demonstrated to be a high-potential technology for remediation of arsenic-contaminated groundwater. Copyright © 2017 Elsevier Ltd. All rights reserved.
Marwani, Hadi M; Alsafrani, Amjad E; Asiri, Abdullah M; Rahman, Mohammed M
2016-06-29
A new ionic liquid loaded silica gel amine (SG-APTMS-N,N-EPANTf₂) was developed, as an adsorptive material, for selective adsorption and determination of zirconium, Zr(IV), without the need for a chelating intermediate. Based on a selectivity study, the SG-APTMS-N,N-EPANTf₂ phase showed a perfect selectivity towards Zr(IV) at pH 4 as compared to other metallic ions, including gold [Au(III)], copper [Cu(II)], cobalt [Co(II)], chromium [Cr(III)], lead [Pb(II)], selenium [Se(IV)] and mercury [Hg(II)] ions. The influence of pH, Zr(IV) concentration, contact time and interfering ions on SG-APTMS-N,N-EPANTf₂ uptake for Zr(IV) was evaluated. The presence of incorporated donor atoms in newly synthesized SG-APTMS-N,N-EPANTf₂ phase played a significant role in enhancing its uptake capacity of Zr(IV) by 78.64% in contrast to silica gel (activated). The equilibrium and kinetic information of Zr(IV) adsorption onto SG-APTMS-N,N-EPANTf₂ were best expressed by Langmuir and pseudo second-order kinetic models, respectively. General co-existing cations did not interfere with the extraction and detection of Zr(IV). Finally, the analytical efficiency of the newly developed method was also confirmed by implementing it for the determination of Zr(IV) in several water samples.
Lu, Chenyang; Jin, Ke; Béland, Laurent K.; ...
2016-02-01
We report that energetic ions have been widely used to evaluate the irradiation tolerance of structural materials for nuclear power applications and to modify material properties. It is important to understand the defect production, annihilation and migration mechanisms during and after collision cascades. In this study, single crystalline pure nickel metal and single-phase concentrated solid solution alloys of 50%Ni50%Co (NiCo) and 50%Ni50%Fe (NiFe) without apparent preexisting defect sinks were employed to study defect dynamics under ion irradiation. Both cross-sectional transmission electron microscopy characterization (TEM) and Rutherford backscattering spectrometry channeling (RBS-C) spectra show that the range of radiation-induced defect clusters farmore » exceed the theoretically predicted depth in all materials after high-dose irradiation. Defects in nickel migrate faster than in NiCo and NiFe. Both vacancy-type stacking fault tetrahedra (SFT) and interstitial loops coexist in the same region, which is consistent with molecular dynamics simulations. Kinetic activation relaxation technique (k-ART) simulations for nickel showed that small vacancy clusters, such as di-vacancies and tri-vacancies, created by collision cascades are highly mobile, even at room temperature. The slower migration of defects in the alloy along with more localized energy dissipation of the displacement cascade may lead to enhanced radiation tolerance.« less
Multiproteinopathy, neurodegeneration and old age: a case study.
Rojas, Julio C; Stephens, Melanie L; Rabinovici, Gil D; Kramer, Joel H; Miller, Bruce L; Seeley, William W
2018-02-01
A complex spectrum of mixed brain pathologies is common in older people. This clinical pathologic conference case study illustrates the challenges of formulating clinicopathologic correlations in late-onset neurodegenerative diseases featuring cognitive-behavioral syndromes with underlying multiple proteinopathy. Studies on the co-existence and interactions of Alzheimer's disease (AD) with neurodegenerative non-AD pathologies in the aging brain are needed to understand the pathogenesis of neurodegeneration and to support the development of diagnostic biomarkers and therapies.
Multiproteinopathy, neurodegeneration and old age: a case study
Rojas, Julio C.; Stephens, Melanie L.; Rabinovici, Gil D.; Kramer, Joel H.; Miller, Bruce L.; Seeley, William W.
2018-01-01
A complex spectrum of mixed brain pathologies is common in older people. This clinical pathologic conference case study illustrates the challenges of formulating clinicopathologic correlations in late-onset neurodegenerative diseases featuring cognitive-behavioral syndromes with underlying multiple proteinopathy. Studies on the co-existence and interactions of Alzheimer’s disease (AD) with neurodegenerative non-AD pathologies in the aging brain are needed to understand the pathogenesis of neurodegeneration and to support the development of diagnostic biomarkers and therapies. PMID:29307276
Spinal Intramedullary Abscess Secondary to Dermal Sinus in Children.
Prasad, G Lakshmi; Hegde, Ajay; Divya, S
2018-06-01
Congenital dermal sinuses (CDS) are uncommon lesions. They are most often noted in lumbosacral region and may lead to meningitis or spinal abscess. Intramedullary spinal cord abscess (IMSCA) due to CDS is rare and often co-exists with an inclusion tumor such as dermoid/epidermoid cyst. Literature review was done to analyze all cases of pediatric IMSCA secondary to CDS by searching online databases starting from the oldest case reported. Only 50 cases have been reported and were analyzed. Mean age was 22.6 months (range 1 month-15 years). Fever, acute flaccid lower limb weakness, and urinary disturbances were the most common presenting features. Dermal sinus was commonest in lumbosacral region. Inclusion cysts were observed in 50% of cases. Staphylococcus aureus was the most the common organism. Mean follow-up duration was 18.2 months (range 1 week-156 months). Majority of the cases underwent multilevel laminectomy with myelotomy and drainage of abscess. Outcome was good-to-excellent in around 60% cases with four deaths. Presence of fever and limb weakness was significantly associated with poor outcomes. Intramedullary abscess secondary to CDS is very rare. Complete sinus tract excision, myelotomy and drainage of abscess, and decompression of co-existent inclusion cysts with prolonged antibiotic therapy remain the standard treatment. Approximately 60% cases achieve good outcomes. Fever and limb weakness portend poorer outcomes than those without. Georg Thieme Verlag KG Stuttgart · New York.
Jiang, Li-Cheng; Cao, Jia-Yu; Chen, Mao
2017-12-01
Coronary artery aneurysm (CAA) with concomitant aneurysms at multiple sites is quite unusual and rare. The characteristics and the etiology of this phenomenon are unknown. Herein, we present a case with right coronary aneurysm with concomitant abdominal aorta as well as right renal artery aneurysm. A systematic review of the literatures regarding CAA with other coexisting aneurysms at multiple locations was also conducted on Medline and Embase databases. A total of 76 patients (male gender: 58; age: 37.4 ± 26.5) including the present case were included in the final study. The most common etiology of CAA with multiple aneurysms was Kawasaki (43.3%) and atherosclerotic disease (16.4%). CAA was the most frequently found at the right coronary artery (62.7%), following, left anterior descending (51%), left main (43.1%), and left circumflex (35.3%). The most common concomitant aneurysms were abdominal aorta (52.6%) and iliac artery (50%). In addition, 60.5% of the patients had an involved bilateral peripheral artery. CAA with coexisting systemic aneurysms in multiple sites is quite rare. And it usually involves multiple aneurysms at the coronary and bilateral peripheral arteries simultaneously. Currently, there are no general consensus regarding the clinical characteristics, diagnostic method, and treatment of these cases. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.
Gupta, Soham; Shenoy, Vishnu Prasad; Mukhopadhyay, Chiranjay; Bairy, Indira; Muralidharan, Sethumadhavan
2011-01-01
To determine the frequency of underlying risk factors and the socio-economic impact based on occupation in the development of tuberculosis. Retrospective analysis of 207 clinically and microbiologically diagnosed patients with pulmonary tuberculosis (PTB) admitted to Kasturba Hospital in 2005 and 2006. Demographic details and underlying risk factors were statistically evaluated. Diabetes mellitus (DM) (30.9%) was the most prevalent condition and significantly more common than other risk factors like smoking (16.9%), alcoholism (12.6%), HIV (10.6%), malignancy (5.8%), chronic liver diseases (3.9%), history of contact with TB (3.4%), chronic corticosteroid therapy (2.9%), chronic kidney diseases and malnourishment (1.5%). There were 82 patients (39.6%) with no underlying risk factor. Men (M:F = 3.7:1) and patients older than 40 years had a higher incidence of co-existing conditions. PTB was significantly more common in blue-collar (44%) and white-collar (27.1%) workers than household workers (12.1%), students (10.6%) and retired/unemployed people (6.3%). Pulmonary tuberculosis had a significant impact and predominated in male patients co-existing with DM. Patients with DM and suggestive pulmonary symptoms should be screened for tuberculosis. More stringent health education and awareness programme should be implemented at the grass root level. © 2010 Blackwell Publishing Ltd.
Khan, Nymul E; Adewuyi, Yusuf G
2011-01-21
A new method for the determination of peroxydisulfate using ion chromatography has been developed. Elution of peroxydisulfate was effected by isocratic elution using 200 mM NaOH at 40°C. A modification of the method using gradient elution was able to simultaneously determine other common inorganic ions (nitrate, nitrite, sulfate and chloride) down to significantly low concentrations in a peroxydisulfate matrix. The relative standard deviations (RSD) were in the range of 0.5-5%, for peak areas and <0.2% for peak retention times. The recoveries were between 95% and 120% for a concentration range of about 0.5-42 ppm. The limit of detection for peroxydisulfate ion was 0.2 ppm and for the other ions were ≤2×10(-2) ppm. The calibration curves were linear with slope and intercepts close to 1 and 0, respectively. Copyright © 2010 Elsevier B.V. All rights reserved.
Large area multiarc ion beam source {open_quote}MAIS{close_quote}
DOE Office of Scientific and Technical Information (OSTI.GOV)
Engelko, V.; Giese, H.; Schalk, S.
1996-12-31
A pulsed large area intense ion beam source is described, in which the ion emitting plasma is built up by an array of individual discharge units, homogeneously distributed over the surface of a common discharge electrode. A particularly advantageous feature of the source is that for plasma generation and subsequent acceleration of the ions only one common energy supply is necessary. This allows to simplify the source design and provides inherent synchronization of plasma production and ion extraction. The homogeneity of the plasma density was found to be superior to plasma sources using plasma expanders. Originally conceived for the productionmore » of proton beams, the source can easily be modified for the production of beams composed of carbon and metal ions or mixed ion species. Results of investigations of the source performance for the production of a proton beam are presented. The maximum beam current achieved to date is of the order of 100 A, with a particle kinetic energy of 15 - 30 keV and a pulse length in the range of 10 {mu}s.« less
Thymic pathology and cardiac myxomas: Coincidence or a closer relationship?
Moraitis, Sotirios D; Agrafiotis, Apostolos C; Pappas, Dimitrios; Pothitakis, Chrysovalantis; Stergianni, Maria; Koukis, Ioannis
2018-04-30
Myxomas are the most common benign cardiac tumors and are located more frequently in the left atrium. In the literature there are cases describing the coexistence of thymic tumors and cardiac myxomas. In the case reported herein, during the resection of a cardiac myxoma, an enlarged thymus gland was encountered and resected. The histological exam revealed a thymic hyperplasia. The aim of this case study is to assess the need of conducting further studies in order to identify a common histological pathway between thymic lesions and cardiac myxomas. The diagnosis of a cardiac myxoma could justify a further workup of the anterior mediastinum in order not to overlook a lesion of thymic origin.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ferguson, Jill Wisnewski
2006-01-01
The inductively coupled plasma (ICP) is an atmospheric pressure ionization source. Traditionally, the plasma is sampled via a sampler cone. A supersonic jet develops behind the sampler, and this region is pumped down to a pressure of approximately one Torr. A skimmer cone is located inside this zone of silence to transmit ions into the mass spectrometer. The position of the sampler and skimmer cones relative to the initial radiation and normal analytical zones of the plasma is key to optimizing the useful analytical signal [1]. The ICP both atomizes and ionizes the sample. Polyatomic ions form through ion-molecule interactionsmore » either in the ICP or during ion extraction [l]. Common polyatomic ions that inhibit analysis include metal oxides (MO +), adducts with argon, the gas most commonly used to make up the plasma, and hydride species. While high resolution devices can separate many analytes from common interferences, this is done at great cost in ion transmission efficiency--a loss of 99% when using high versus low resolution on the same instrument [2]. Simple quadrupole devices, which make up the bulk of ICP-MS instruments in existence, do not present this option. Therefore, if the source of polyatomic interferences can be determined and then manipulated, this could potentially improve the figures of merit on all ICP-MS devices, not just the high resolution devices often utilized to study polyatomic interferences.« less
Ataabadi, Mitra; Hoodaji, Mehran; Tahmourespour, Arezoo; Kalbasi, Mahmoud; Abdouss, Majid
2015-01-01
Hexavalent chromium is a mutagen and carcinogen that is of significant concern in water and wastewater. In the present study, magnetite nanoparticles (n-Mag) were investigated as a potential remediation technology for the decontamination of Cr (VI)-contaminated wastewater. Synthesized n-Mag was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and BET-N2 technology. To screen and optimize the factors affecting Cr (VI) removal efficiency by synthesized nanoparticles, Plackett-Burman (PB) and Taguchi experimental designs were used respectively. The crystalline produced n-Mag was in the size range of 60-70 nm and had a specific surface area (SSA) of 31.55 m(2) g(-1). Results of PB design showed that the most significant factors affecting Cr (VI) removal efficiency were initial Cr (VI) concentration, pH, n-Mag dosage, and temperature. In a pH of 2, 20 mg L(-1) of Cr (VI) concentration, 4 g L(-1)of n-Mag, temperature of 40 °C, 220 rpm of shaking speed, and 60 min of contact time, the complete removal efficiency of Cr (VI) was achieved. Batch experiments revealed that the removal of Cr (VI) by n-Mag was consistent with pseudo-second order reaction kinetics. The competition from common coexisting ions such as NO₃(-), SO₄(2-), and Cl(-) were not considerable, unless in the higher concentration of SO₄(2-). These results indicated that the readily synthesized magnetite nanoparticles have promising applications for the removal of Cr (VI) from aqueous solution.
Colorimetric detection of melamine based on p-chlorobenzenesulfonic acid-modified AuNPs
NASA Astrophysics Data System (ADS)
Li, Jianfang; Huang, Pengcheng; Wu, Fangying
2016-06-01
A highly selective and sensitive method is developed for colorimetric detection of melamine using gold nanoparticles (AuNPs) functionalized with p-chlorobenzenesulfonic acid. The addition of melamine induced the aggregation of AuNPs, as evidenced from the morphological characterizations and the color changed from red wine to blue, which could also be monitored by the UV-visible spectrometer and even naked eyes. This process caused a significant increase in the absorbance ratio (A650nm/A520nm) of p-chlorobenzenesulfonic acid-AuNPs. Under optimized conditions, the system exhibited a linear response to melamine in the range of 6.0 × 10-7-1.5 × 10-6 mol L-1 with a correlation coefficient of 0.997, and the limit of detection can even be 2.3 nM, which was much lower than some other methods and the safe limits (20 μM in both the USA and EU, 8.0 μM for infant formula in China, 1.2 μM in the CAC (Codex Alimentarius Commission) review for melamine in liquid infant formula). More importantly, the developed method presented excellent tolerance to coexisting common metal ions such as Ca2+, Zn2+, whose concentration is 1000 times of melamine, so that it had been applied to the analysis of melamine in liquid milk and milk powder with the recovery of 97.0-101 % and 100-103 %, respectively, indicating that the proposed method is quite a highly effective means to determine melamine in milk products.
NASA Astrophysics Data System (ADS)
Sun, Tianyi; Zhao, Zhiwei; Liang, Zhijie; Liu, Jie; Shi, Wenxin; Cui, Fuyi
2017-09-01
Bifunctional ZrO2-Fe3O4 magnetic nanoparticles were synthesized and characterized, to remove As(III) through photocatalyic oxidation and adsorption. With a saturation magnetization of 27.39 emu/g, ZrO2-Fe3O4 nanoparticles with size of 10-30 nm could be easily separated from solutions with a simple magnetic process. Under UV light, As(III) could be completely oxidized to less toxic As(V) by ZrO2-Fe3O4 nanoparticles within 40 min in the photocatalytic reaction. Simultaneously, As(V) could be adsorbed onto the surface of nanoparticles with high efficiency. The adsorption of As(V) was well fitted by the pseudo-second-order model and the Freundlich isotherm model, respectively, and the maximum adsorption capacities of the nanoparticles was 133.48 mg/g at pH 7.0. As(III) could be effectively removed by ZrO2-Fe3O4 nanoparticles at initial pH range from 4 to 8. Among all the common coexisting ions investigated, except for chloride and sulfate, carbonate, silicate and phosphate decreased the As(III) removal by competing with arsenic species for adsorption sites. The synthesized magnetic ZrO2-Fe3O4 combined the photocatalytic oxidation property of ZrO2 and the high adsorption capacity of both ZrO2 and Fe3O4, which make it have significant potential applications in the As(III)-contaminated water treatment.
Complex structures of different CaFe2As2 samples
Saparov, Bayrammurad; Cantoni, Claudia; Pan, Minghu; Hogan, Thomas C.; II, William Ratcliff; Wilson, Stephen D.; Fritsch, Katharina; Gaulin, Bruce D.; Sefat, Athena S.
2014-01-01
The interplay between magnetism and crystal structures in three CaFe2As2 samples is studied. For the nonmagnetic quenched crystals, different crystalline domains with varying lattice parameters are found, and three phases (orthorhombic, tetragonal, and collapsed tetragonal) coexist between TS = 95 K and 45 K. Annealing of the quenched crystals at 350°C leads to a strain relief through a large (~1.3%) expansion of the c-parameter and a small (~0.2%) contraction of the a-parameter, and to local ~0.2 Å displacements at the atomic-level. This annealing procedure results in the most homogeneous crystals for which the antiferromagnetic and orthorhombic phase transitions occur at TN/TS = 168(1) K. In the 700°C-annealed crystal, an intermediate strain regime takes place, with tetragonal and orthorhombic structural phases coexisting between 80 to 120 K. The origin of such strong shifts in the transition temperatures are tied to structural parameters. Importantly, with annealing, an increase in the Fe-As length leads to more localized Fe electrons and higher local magnetic moments on Fe ions. Synergistic contribution of other structural parameters, including a decrease in the Fe-Fe distance, and a dramatic increase of the c-parameter, which enhances the Fermi surface nesting in CaFe2As2, are also discussed. PMID:24844399
John, Rohit Abraham; Liu, Fucai; Chien, Nguyen Anh; Kulkarni, Mohit R; Zhu, Chao; Fu, Qundong; Basu, Arindam; Liu, Zheng; Mathews, Nripan
2018-06-01
Emulation of brain-like signal processing with thin-film devices can lay the foundation for building artificially intelligent learning circuitry in future. Encompassing higher functionalities into single artificial neural elements will allow the development of robust neuromorphic circuitry emulating biological adaptation mechanisms with drastically lesser neural elements, mitigating strict process challenges and high circuit density requirements necessary to match the computational complexity of the human brain. Here, 2D transition metal di-chalcogenide (MoS 2 ) neuristors are designed to mimic intracellular ion endocytosis-exocytosis dynamics/neurotransmitter-release in chemical synapses using three approaches: (i) electronic-mode: a defect modulation approach where the traps at the semiconductor-dielectric interface are perturbed; (ii) ionotronic-mode: where electronic responses are modulated via ionic gating; and (iii) photoactive-mode: harnessing persistent photoconductivity or trap-assisted slow recombination mechanisms. Exploiting a novel multigated architecture incorporating electrical and optical biases, this incarnation not only addresses different charge-trapping probabilities to finely modulate the synaptic weights, but also amalgamates neuromodulation schemes to achieve "plasticity of plasticity-metaplasticity" via dynamic control of Hebbian spike-time dependent plasticity and homeostatic regulation. Coexistence of such multiple forms of synaptic plasticity increases the efficacy of memory storage and processing capacity of artificial neuristors, enabling design of highly efficient novel neural architectures. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
NASA Astrophysics Data System (ADS)
Papanicolopoulos, Chrysanthos Dionisios
1987-11-01
The excited states of ^{185 }{rm Au} have been studied by the radioactive decay of {^ {185m,g}Hg.} Sources of {^{185m,g}Hg} were produced by the reaction ^{176 }Hf (^{16}O, 7n) ^{185}Hg using 140 MeV ^{16}O beams from the 25 MV folded tandem of the Holifield Heavy Ion Research Facility. Sources of ^{185}Hg were mass-separated on-line using the University Isotope Separator Oak Ridge (UNISOR) facility. Multiscaled spectra of rays, x rays and conversion electrons were obtained together with gamma- gamma - t, gamma- x - t, e ^{-} - gamma - t, and e^{-}- x - t coincidence data. A decay scheme consisting of 82 excited states and 182 transitions was constructed. Bands of states associated with the s_{1over 2}, d_{3over 2} , d_{5over 2}, h_{11over 2} proton -hole configurations and the h_{9over 2} and i_{13over 2} proton-particle (intruder) configurations were constructed. In addition, a number of EO transitions were located: these de-excite levels which are interpreted as resulting from shape coexistence in the ^ {184}Pt and ^{186 }Hg "particle" and "hole" cores. The h _{9over 2} band is compared with calculations made with the Lund model of Larsson et al.
NASA Astrophysics Data System (ADS)
Reim, J. D.; Rosén, E.; Zaharko, O.; Mostovoy, M.; Robert, J.; Valldor, M.; Schweika, W.
2018-04-01
The hexagonal swedenborgite, CaBaCo2Fe2O7 , is a chiral frustrated antiferromagnet, in which magnetic ions form alternating kagome and triangular layers. We observe a long-range √{3 }×√{3 } antiferromagnetic order setting in below TN=160 K by neutron diffraction on single crystals of CaBaCo2Fe2O7 . Both magnetization and polarized neutron single crystal diffraction measurements show that close to TN spins lie predominantly in the a b plane, while upon cooling the spin structure becomes increasingly canted due to Dzyaloshinskii-Moriya interactions. The ordered structure can be described and refined within the magnetic space group P 31 m' . Diffuse scattering between the magnetic peaks reveals that the spin order is partial. Monte Carlo simulations based on a Heisenberg model with two nearest-neighbor exchange interactions show a similar diffuse scattering and coexistence of the √{3 }×√{3 } order with disorder. The coexistence can be explained by the freedom to vary spins without affecting the long-range order, which gives rise to ground-state degeneracy. Polarization analysis of the magnetic peaks indicates the presence of long-period cycloidal spin correlations resulting from the broken inversion symmetry of the lattice, in agreement with our symmetry analysis.
Nakabayashi, Ryo; Tsugawa, Hiroshi; Kitajima, Mariko; Takayama, Hiromitsu; Saito, Kazuki
2015-01-01
In metabolomics, the analysis of product ions in tandem mass spectrometry (MS/MS) is noteworthy to chemically assign structural information. However, the development of relevant analytical methods are less advanced. Here, we developed a method to boost sensitivity in liquid chromatography–Fourier transform ion cyclotron resonance–tandem mass spectrometry analysis (MS/MS boost analysis). To verify the MS/MS boost analysis, both quercetin and uniformly labeled 13C quercetin were analyzed, revealing that the origin of the product ions is not the instrument, but the analyzed compounds resulting in sensitive product ions. Next, we applied this method to the analysis of monoterpene indole alkaloids (MIAs). The comparative analyses of MIAs having indole basic skeleton (ajmalicine, catharanthine, hirsuteine, and hirsutine) and oxindole skeleton (formosanine, isoformosanine, pteropodine, isopteropodine, rhynchophylline, isorhynchophylline, and mitraphylline) identified 86 and 73 common monoisotopic ions, respectively. The comparative analyses of the three pairs of stereoisomers showed more than 170 common monoisotopic ions in each pair. This method was also applied to the targeted analysis of MIAs in Catharanthus roseus and Uncaria rhynchophylla to profile indole and oxindole compounds using the product ions. This analysis is suitable for chemically assigning features of the metabolite groups, which contributes to targeted metabolome analysis. PMID:26734034
Coexistence of Colorectal Adenomas and Coronary Calcification in Asymptomatic Men and Women.
Yun, Kyung Eun; Chang, Yoosoo; Rampal, Sanjay; Zhang, Yiyi; Cho, Juhee; Jung, Hyun-Suk; Kim, Chan-Won; Jeong, Chul; Cainzos-Achirica, Miguel; Zhao, Di; Pastor-Barriuso, Roberto; Shin, Hocheol; Guallar, Eliseo; Ryu, Seungho
2018-07-01
Because of shared risk factors between clinically manifest cardiovascular disease and colorectal cancer, we hypothesized the coexistence of subclinical atherosclerosis measured by coronary artery calcium (CAC) and colorectal adenoma (CRA) and that these 2 processes would also share common risk factors. No study has directly compared the risk factors associated with subclinical coronary atherosclerosis and CRA. This was a cross-sectional study using multinomial logistic regression analysis of 4859 adults who participated in a health screening examination (2010 to 2011; analysis 2014 to 2015). CAC scores were categorized as 0, 1 to 100, or >100. Colonoscopy results were categorized as absent, low-risk, or high-risk CRA. The prevalence of CAC>0, CAC 1 to 100 and >100 was 13.0%, 11.0%, and 2.0%, respectively. The prevalence of any CRA, low-risk CRA, and high-risk CRA was 15.1%, 13.0%, and 2.1%, respectively. The adjusted odds ratios (95% confidence interval) for CAC>0 comparing participants with low-risk and high-risk CRA with those without any CRA were 1.35 (1.06-1.71) and 2.09 (1.29-3.39), respectively. Similarly, the adjusted odds ratios (95% confidence interval) for any CRA comparing participants with CAC 1 to 100 and CAC>100 with those with no CAC were 1.26 (1.00-1.6) and 2.07 (1.31-3.26), respectively. Age, smoking, diabetes, and family history of CRC were significantly associated with both conditions. We observed a graded association between CAC and CRA in apparently healthy individuals. The coexistence of both conditions further emphasizes the need for more evidence of comprehensive approaches to screening and the need to consider the impact of the high risk of coexisting disease in individuals with CAC or CRA, instead of piecemeal approaches restricted to the detection of each disease independently.
Coexisting calderite and spessartine garnets in eclogite-facies metacherts of the Western Alps
NASA Astrophysics Data System (ADS)
Cenki-Tok, B.; Chopin, C.
2006-09-01
The coexistence of a colourless and a yellow garnet was observed in eclogite-facies manganese concentrations of the Mesozoic ophiolitic Zermatt-Saas Unit, at the Praborna mine near Saint-Marcel, Val d’Aoste, Italy, and in the upper Maurienne Valley, France. They occur both in oxidised metachert with hematite and braunite (+ minor Mn-pyroxenoid and tirodite, rare tiragalloite; with ardennite or piemontite in distinct layers), and in more reduced, carbonate-rich boudins included in it. The co-occurrence takes a variety of textural aspects, from coexisting euhedral garnets (10-100 µm in size for the calderite to mm-size for spessartine) to sharp overgrowths of yellow calderitic garnet on colourless spessartine, to yellow cauliflower-like masses (a few hundreds of µm in size) overgrowing colourless spessartine and showing evidence of oscillatory zoning, resorption stages and resumed growth. Sector zoning and anisotropy are common, although not consistent features. Compositions can be expressed to 95% in the quadrilateral system (Ca, Mn2+)3 (Al, Fe3+)2 Si3O12, with less than 1.0 wt% MgO and 0.8 wt% TiO2 in colourless spessartine, and less than 0.2 wt% MgO and 1.6 wt% TiO2 in yellow garnet. Calcium partitions into the ferric garnet. Coexisting pairs define two compositional gaps, bounded by values of the Fe3+/(Al + Fe3+) ratio of 10 and 15% for the first one, of 40 and 65% for the other. The optically obvious discontinuity (colour change and Becke’s line) corresponds to the narrower gap, between colourless spessartine and yellow spessartine, whereas the broad compositional gap occurs within yellow garnet, between yellow spessartine and yellow calderite, and is only revealed by back-scattered electron images. Only the latter can be a candidate for a miscibility gap, if any.
Matteson, Kevin
2018-01-01
Understanding human-wildlife conflict is an important first step in the conservation of highly endangered species that can have adverse effects on human communities, such as elephants. To gain insights into variables that shape attitudes toward elephant conservation in Asia, we surveyed 410 households and 46 plantation owners in seven villages around the Salakpra Wildlife Sanctuary in western Thailand, an area of high human-elephant conflict. We sought to evaluate how past experiences with elephants (positive or negative), as well as socio-economic variables (age, income level, gender, and employment type) affect attitudes toward elephant conservation and coexistence in this area. In addition, we quantified deterrence methods currently used and identify potential mitigation strategies supported by community members. In general, less supportive attitudes toward elephant conservation and coexistence were held by individuals older than 35 years of age, those who had previously had experienced negative interactions with elephants, those with lower incomes, and those working in the agricultural sector. Conversely, those who had received benefits from living near elephants (e.g., supplemental income or feelings of pride from hosting volunteers or participating in conservation work) had more supportive views of elephant coexistence. Plantation owners reported using a variety of deterrence methods with varying success, with firecrackers being the most commonly utilized method. Community members identified several potentially beneficial mitigation strategies including forest restorations and patrol teams, adding water sources to wild elephant habitat, and education of local school and community groups. Overall, our results highlight the value of community members receiving benefits from living near elephants and suggest that special incentives may be needed for demographic groups disproportionately affected by elephants (e.g. those at lower income levels, those working in agriculture). A combination of these and other approaches will be required if human-elephant coexistence in western Thailand is to be realized. PMID:29856740
Coexistence: Threat to the Performance of Heterogeneous Network
NASA Astrophysics Data System (ADS)
Sharma, Neetu; Kaur, Amanpreet
2010-11-01
Wireless technology is gaining broad acceptance as users opt for the freedom that only wireless network can provide. Well-accepted wireless communication technologies generally operate in frequency bands that are shared among several users, often using different RF schemes. This is true in particular for WiFi, Bluetooth, and more recently ZigBee. These all three operate in the unlicensed 2.4 GHz band, also known as ISM band, which has been key to the development of a competitive and innovative market for wireless embedded devices. But, as with any resource held in common, it is crucial that those technologies coexist peacefully to allow each user of the band to fulfill its communication goals. This has led to an increase in wireless devices intended for use in IEEE 802.11 wireless local area networks (WLANs) and wireless personal area networks (WPANs), both of which support operation in the crowded 2.4-GHz industrial, scientific and medical (ISM) band. Despite efforts made by standardization bodies to ensure smooth coexistence it may occur that communication technologies transmitting for instance at very different power levels interfere with each other. In particular, it has been pointed out that ZigBee could potentially experience interference from WiFi traffic given that while both protocols can transmit on the same channel, WiFi transmissions usually occur at much higher power level. In this work, we considered a heterogeneous network and analyzed the impact of coexistence between IEEE 802.15.4 and IEEE 802.11b. To evaluate the performance of this network, measurement and simulation study are conducted and developed in the QualNet Network simulator, version 5.0.Model is analyzed for different placement models or topologies such as Random. Grid & Uniform. Performance is analyzed on the basis of characteristics such as throughput, average jitter and average end to end delay. Here, the impact of varying different antenna gain & shadowing model for this heterogeneous network is considered for the purpose of analysis.
Pollinator Foraging Adaptation and Coexistence of Competing Plants
Revilla, Tomás A.; Křivan, Vlastimil
2016-01-01
We use the optimal foraging theory to study coexistence between two plant species and a generalist pollinator. We compare conditions for plant coexistence for non-adaptive vs. adaptive pollinators that adjust their foraging strategy to maximize fitness. When pollinators have fixed preferences, we show that plant coexistence typically requires both weak competition between plants for resources (e.g., space or nutrients) and pollinator preferences that are not too biased in favour of either plant. We also show how plant coexistence is promoted by indirect facilitation via the pollinator. When pollinators are adaptive foragers, pollinator’s diet maximizes pollinator’s fitness measured as the per capita population growth rate. Simulations show that this has two conflicting consequences for plant coexistence. On the one hand, when competition between pollinators is weak, adaptation favours pollinator specialization on the more profitable plant which increases asymmetries in plant competition and makes their coexistence less likely. On the other hand, when competition between pollinators is strong, adaptation promotes generalism, which facilitates plant coexistence. In addition, adaptive foraging allows pollinators to survive sudden loss of the preferred plant host, thus preventing further collapse of the entire community. PMID:27505254
Narwani, Anita; Alexandrou, Markos A; Oakley, Todd H; Carroll, Ian T; Cardinale, Bradley J
2013-11-01
The coexistence of competing species depends on the balance between their fitness differences, which determine their competitive inequalities, and their niche differences, which stabilise their competitive interactions. Darwin proposed that evolution causes species' niches to diverge, but the influence of evolution on relative fitness differences, and the importance of both niche and fitness differences in determining coexistence have not yet been studied together. We tested whether the phylogenetic distances between species of green freshwater algae determined their abilities to coexist in a microcosm experiment. We found that niche differences were more important in explaining coexistence than relative fitness differences, and that phylogenetic distance had no effect on either coexistence or on the sizes of niche and fitness differences. These results were corroborated by an analysis of the frequency of the co-occurrence of 325 pairwise combinations of algal taxa in > 1100 lakes across North America. Phylogenetic distance may not explain the coexistence of freshwater green algae. © 2013 John Wiley & Sons Ltd/CNRS.
Zealotry promotes coexistence in the rock-paper-scissors model of cyclic dominance
NASA Astrophysics Data System (ADS)
Verma, Gunjan; Chan, Kevin; Swami, Ananthram
2015-11-01
Cyclic dominance models, such as the classic rock-paper-scissors (RPS) game, have found real-world applications in biology, ecology, and sociology. A key quantity of interest in such models is the coexistence time, i.e., the time until at least one population type goes extinct. Much recent research has considered conditions that lengthen coexistence times in an RPS model. A general finding is that coexistence is promoted by localized spatial interactions (low mobility), while extinction is fostered by global interactions (high mobility). That is, there exists a mobility threshold which separates a regime of long coexistence from a regime of rapid collapse of coexistence. The key finding of our paper is that if zealots (i.e., nodes able to defeat others while themselves being immune to defeat) of even a single type exist, then system coexistence time can be significantly prolonged, even in the presence of global interactions. This work thus highlights a crucial determinant of system survival time in cyclic dominance models.
Lehtinen, Sonja; Blanquart, François; Croucher, Nicholas J.; Turner, Paul; Lipsitch, Marc; Fraser, Christophe
2017-01-01
Understanding how changes in antibiotic consumption affect the prevalence of antibiotic resistance in bacterial pathogens is important for public health. In a number of bacterial species, including Streptococcus pneumoniae, the prevalence of resistance has remained relatively stable despite prolonged selection pressure from antibiotics. The evolutionary processes allowing the robust coexistence of antibiotic sensitive and resistant strains are not fully understood. While allelic diversity can be maintained at a locus by direct balancing selection, there is no evidence for such selection acting in the case of resistance. In this work, we propose a mechanism for maintaining coexistence at the resistance locus: linkage to a second locus that is under balancing selection and that modulates the fitness effect of resistance. We show that duration of carriage plays such a role, with long duration of carriage increasing the fitness advantage gained from resistance. We therefore predict that resistance will be more common in strains with a long duration of carriage and that mechanisms maintaining diversity in duration of carriage will also maintain diversity in antibiotic resistance. We test these predictions in S. pneumoniae and find that the duration of carriage of a serotype is indeed positively correlated with the prevalence of resistance in that serotype. These findings suggest heterogeneity in duration of carriage is a partial explanation for the coexistence of sensitive and resistant strains and that factors determining bacterial duration of carriage will also affect the prevalence of resistance. PMID:28096340
D'Amico, Marcello; Catry, Inês; Martins, Ricardo C; Ascensão, Fernando; Barrientos, Rafael; Moreira, Francisco
2018-02-24
Power-line grids are increasingly expanding worldwide, as well as their negative impacts on avifauna, namely the direct mortality through collision and electrocution, the reduction of breeding performance, and the barrier effect. On the other hand, some bird species can apparently benefit from the presence of power lines, for example perching for hunting purposes or nesting on electricity towers. In this perspective essay, we reviewed the scientific literature on both costs and benefits for avifauna coexisting with power lines. Overall, we detected a generalized lack of studies focusing on these costs or benefits at a population level. We suggest that a switch in research approach to a larger spatio-temporal scale would greatly improve our knowledge about the actual effects of power lines on bird populations. This research approach would facilitate suitable landscape planning encompassing both mitigation of costs and promotion of benefits for bird populations coexisting with power lines. For example, the strategic route planning of electricity infrastructures would limit collision risk or barrier effects for threatened bird populations. Concurrently, this strategic route planning would promote the range expansion of threatened populations of other bird species, by providing nesting structures in treeless but potentially suitable landscapes. We suggest establishing a collaborative dialogue among the scientific community, governments, and electricity companies, with the aim to produce a win-win scenario in which both biodiversity conservation and infrastructure development are integrated in a common strategy.
Li, Weihua; Qiu, Tian; Guo, Lei; Ling, Yun; Gao, Yibo; Ying, Jianming; He, Jie
2018-06-01
Primary EGFR T790M mutation is occasionally identified by routine mutation testing in tyrosine kinase inhibitor (TKI)-naive patients with non-small cell lung cancer (NSCLC). We herein aimed to compare the characteristics of primary and acquired T790M mutations in NSCLC patients, and their response to osimertinib. Using amplification refractory mutation system (ARMS) detection, primary T790M was identified in 0.5% (46/8723) of TKI-naive patients, whereas acquired T790M was detected in 49.7% (71/143) of TKI-relapsed patients. T790M always coexisted with a sensitizing EGFR mutation. Primary T790M more commonly coexisted with L858R, whereas acquired T790M was more likely to coexist with exon 19 deletions. Moreover, next-generation sequencing (NGS) showed that concomitant sensitizing EGFR and primary T790M mutant allele frequencies (MAFs) were highly concordant, but acquired T790M MAFs were significantly lower than the sensitizing EGFR MAFs. Sixteen acquired T790M-mutant patients received osimertinib. The median progression-free survival (PFS) was 8.1 months. Four primary T790M-mutant patients received osimertinib and the median PFS was 8.0 months. Together, our study demonstrates that primary and acquired T790M-mutant patients show distinct differences in some clinical and molecular characteristics, but may both respond to osimertinib treatment. Copyright © 2018 Elsevier B.V. All rights reserved.
WASP-ASSOCIATED FACTORS ACT IN INTERSPECIES COMPETITION DURING MULTIPARASITISM.
Magdaraog, Peter M; Tanaka, Toshiharu; Harvey, Jeffrey A
2016-06-01
Coexistence or displacement of parasitoids in hosts during intrinsic competitive interactions between different parasitoid species (multiparasitism) may depend on their life history traits and behavior. Intense competition for possession of hosts may lead to the elimination of the inferior competitor through physical attack and/or physiological suppression. However, the mechanisms of physiological suppression during multiparasitism remain unclear. Previous work has shown that first instar larvae of the solitary endoparasitoid Meteorus pulchricornis possess well-developed mandibles that are used to kill competitors. Two gregarious endoparasitoids, Cotesia kariyai and C. rufricus, share host resources especially when the time gap of oviposition is short. Here, we investigated the physiological influence of wasp-regulatory factors of the three endoparasitoids, M. pulchricornis, C. kariyai, and C. ruficrus, in their common host Mythimna separata. We found that MpVLP alone (or with venom) deleteriously affected the development of the two gregarious species. Similarly, CkPDV plus venom had toxic effect on M. pulchricornis eggs and immature larvae, although they were not harmful to immature stages of C. ruficrus. Cotesia kariyai and C. ruficrus were able to coexist mainly through the expression of regulatory factors and both could successfully emerge from a multiparasitized host. The injection of CkPDV plus venom after oviposition in L5 host larvae facilitated C. ruficrus development and increased the rate of successful parasitism from 9% to 62%. This suggests that the two gregarious parasitoid wasps exhibit strong phylogenetic affinity, favoring their coexistence and success in multiparasitized hosts. © 2016 Wiley Periodicals, Inc.
Traditional serrated adenoma (TSA): morphological questions, queries and quandaries.
Chetty, Runjan
2016-01-01
Traditional serrated adenoma (TSA) is an uncommon type of serrated adenoma that can be a precursor to biologically aggressive colorectal cancer that invokes the serrated (accelerated) pathway. The purpose of this review is to address some of the more contentious issues around nomenclature, diagnostic criteria, histological variants, coexistence with other polyp types, the occurrence of dysplasia and the differential diagnosis. While the vast majority of TSAs are exophytic villiform polyps composed of deeply eosinophilic cells, flat top luminal serrations and numerous ectopic crypt foci, histological variants include flat TSA, filiform TSA and one composed of large numbers of mucin-containing cells. It is unlikely that there is any biological difference between the histological variants. There is a contention that TSAs are not dysplastic ab initio and that the majority do not show cytological atypia. Two types of dysplasia are associated with TSA. Serrated dysplasia is less well recognised and less commonly encountered than adenomatous dysplasia. TSA with dysplasia must be separated from TSA with coexisting conventional adenoma. TSA is a characteristic polyp that may be extremely exophytic, flat or composed of mucin-rich cells and is typified by numerous ectopic crypt foci. They may coexist with other serrated polyps and conventional adenomas. Approximately 20-25% will be accompanied by adenomatous dysplasia. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
High frequency of coexistent mutations of PIK3CA and PTEN genes in endometrial carcinoma.
Oda, Katsutoshi; Stokoe, David; Taketani, Yuji; McCormick, Frank
2005-12-01
The phosphatidylinositol 3'-kinase (PI3K) pathway is activated in many human cancers. In addition to inactivation of the PTEN tumor suppressor gene, mutations or amplifications of the catalytic subunit alpha of PI3K (PIK3CA) have been reported. However, the coexistence of mutations in these two genes seems exceedingly rare. As PTEN mutations occur at high frequency in endometrial carcinoma, we screened 66 primary endometrial carcinomas for mutations in the helical and catalytic domains of PIK3CA. We identified a total of 24 (36%) mutations in this gene and coexistence of PIK3CA/PTEN mutations at high frequency (26%). PIK3CA mutations were more common in tumors with PTEN mutations (17 of 37, 46%) compared with those without PTEN mutations (7 of 29, 24%). Array comparative genomic hybridization detected 3q24-qter amplification, which covers the PIK3CA gene (3q26.3), in one of nine tumors. Knocking down PTEN expression in the HEC-1B cell line, which possesses both K-Ras and PIK3CA mutations, further enhances phosphorylation of Akt (Ser473), indicating that double mutation of PIK3CA and PTEN has an additive effect on PI3K activation. Our data suggest that the PI3K pathway is extensively activated in endometrial carcinomas, and that combination of PIK3CA/PTEN alterations might play an important role in development of these tumors.
Zhai, Hongyan; Zhang, Xiangru
2009-05-01
With the presence of bromide in source waters, numerous brominated disinfection byproducts (DBPs) are formed during chlorination. Many of them are polar/highly polar DBPs and thus hard to be detected by gas chromatography mass spectrometry. Electrospray ionization triple quadrupole mass spectrometry (ESI-MS/MS) is reported to be an effective method in finding polar brominated DBPs by setting precursor ion scans of m/z 79 and 81. But as a soft ionization technique, ESI could form adducts of common DBPs, which may complicate ESI-MS/MS spectra and hinder the efforts in finding new brominated DBPs. In this paper, a new method was developed for differentiating adducts of common DBPs from higher molecular weight DBPs. This method was based on the ESI-MS/MS precursor ion scans of the fragments that correspond to the molecular ions of common DBPs. Adducts of common DBPs were selectively detected in the ESI-MS/MS spectra of a simulated drinking water sample. Moreover, the structures of several new brominated DBPs in the sample were tentatively proposed.
Degradation mechanism of cyanide in water using a UV-LED/H2O2/Cu2+ system.
Kim, Tae-Kyoung; Kim, Taeyeon; Jo, Areum; Park, Suhyun; Choi, Kyungho; Zoh, Kyung-Duk
2018-06-01
In this study, we developed a UV-LED/H 2 O 2 /Cu 2+ system to remove cyanide, which is typically present in metal electroplating wastewater. The results showed the synergistic effects of UV-LED, H 2 O 2 , and Cu 2+ ions on cyanide removal in comparison with UV-LED photolysis, H 2 O 2 oxidation, UV-LED/H 2 O 2 , and H 2 O 2 /Cu 2+ systems. Cyanide was removed completely in 30 min in the UV-LED/H 2 O 2 /Cu 2+ system, and its loss followed pseudo-first order kinetics. Statistically, both H 2 O 2 and Cu 2+ ions showed positive effects on cyanide removal, but Cu 2+ ions exhibited a greater effect. The highest cyanide removal rate constant (k = 0.179 min -1 ) was achieved at pH 11, but the lowest was achieved at pH 12.5 (k = 0.064 min -1 ) due to the hydrolysis of H 2 O 2 (pK a of H 2 O 2 = 11.75). The presence of dissolved organic matter (DOM) inhibited cyanide removal, and the removal rate constant exhibited a negative linear correlation with DOM (R 2 = 0.987). The removal rate of cyanide was enhanced by the addition of Zn 2+ ions (from 0.179 to 0.457 min -1 ), while the co-existence of Ni 2+ or Cr +6 ion with Cu 2+ ion reduced cyanide removal. The formation of OH radicals in the UV-LED/H 2 O 2 /Cu 2+ system was verified using an aminophenyl fluorescence (APF) probe. Cyanate ions and ammonia were detected as the byproducts of cyanide decomposition. Finally, an acute toxicity reduction of 64.6% was achieved in the system within 1 h, despite a high initial cyanide concentration (100 mg/L). In terms of removal efficiency and toxicity reduction, the UV-LED/H 2 O 2 /Cu 2+ system may be an alternative method of cyanide removal from wastewaters. Copyright © 2018 Elsevier Ltd. All rights reserved.
Park, Ji-Won; Jeong, Hyobin; Kang, Byeongsoo; Kim, Su Jin; Park, Sang Yoon; Kang, Sokbom; Kim, Hark Kyun; Choi, Joon Sig; Hwang, Daehee; Lee, Tae Geol
2015-06-05
Time-of-flight secondary ion mass spectrometry (TOF-SIMS) emerges as a promising tool to identify the ions (small molecules) indicative of disease states from the surface of patient tissues. In TOF-SIMS analysis, an enhanced ionization of surface molecules is critical to increase the number of detected ions. Several methods have been developed to enhance ionization capability. However, how these methods improve identification of disease-related ions has not been systematically explored. Here, we present a multi-dimensional SIMS (MD-SIMS) that combines conventional TOF-SIMS and metal-assisted SIMS (MetA-SIMS). Using this approach, we analyzed cancer and adjacent normal tissues first by TOF-SIMS and subsequently by MetA-SIMS. In total, TOF- and MetA-SIMS detected 632 and 959 ions, respectively. Among them, 426 were commonly detected by both methods, while 206 and 533 were detected uniquely by TOF- and MetA-SIMS, respectively. Of the 426 commonly detected ions, 250 increased in their intensities by MetA-SIMS, whereas 176 decreased. The integrated analysis of the ions detected by the two methods resulted in an increased number of discriminatory ions leading to an enhanced separation between cancer and normal tissues. Therefore, the results show that MD-SIMS can be a useful approach to provide a comprehensive list of discriminatory ions indicative of disease states.
Park, Ji-Won; Jeong, Hyobin; Kang, Byeongsoo; Kim, Su Jin; Park, Sang Yoon; Kang, Sokbom; Kim, Hark Kyun; Choi, Joon Sig; Hwang, Daehee; Lee, Tae Geol
2015-01-01
Time-of-flight secondary ion mass spectrometry (TOF-SIMS) emerges as a promising tool to identify the ions (small molecules) indicative of disease states from the surface of patient tissues. In TOF-SIMS analysis, an enhanced ionization of surface molecules is critical to increase the number of detected ions. Several methods have been developed to enhance ionization capability. However, how these methods improve identification of disease-related ions has not been systematically explored. Here, we present a multi-dimensional SIMS (MD-SIMS) that combines conventional TOF-SIMS and metal-assisted SIMS (MetA-SIMS). Using this approach, we analyzed cancer and adjacent normal tissues first by TOF-SIMS and subsequently by MetA-SIMS. In total, TOF- and MetA-SIMS detected 632 and 959 ions, respectively. Among them, 426 were commonly detected by both methods, while 206 and 533 were detected uniquely by TOF- and MetA-SIMS, respectively. Of the 426 commonly detected ions, 250 increased in their intensities by MetA-SIMS, whereas 176 decreased. The integrated analysis of the ions detected by the two methods resulted in an increased number of discriminatory ions leading to an enhanced separation between cancer and normal tissues. Therefore, the results show that MD-SIMS can be a useful approach to provide a comprehensive list of discriminatory ions indicative of disease states. PMID:26046669
Pharmaceutical Applications of Ion-Exchange Resins
NASA Astrophysics Data System (ADS)
Elder, David P.
2005-04-01
The historical uses of ion-exchange resins and a summary of the basic chemical principles involved in the ion-exchange process are discussed. Specific applications of ion-exchange resins are provided. The utility of these agents to stabilize drugs are evaluated. Commonly occurring chemical and physical incompatibilities are reviewed. Ion-exchange resins have found applicability as inactive pharmaceutical constituents, particularly as disintegrants (inactive tablet ingredient whose function is to rapidly disrupt the tablet matrix on contact with gastric fluid). One of the more elegant approaches to improving palatability of ionizable drugs is the use of ion-exchange resins as taste-masking agents. The selection, optimization of drug:resin ratio and particle size, together with a review of scaleup of typical manufacturing processes for taste-masked products are provided. Ion-exchange resins have been extensively utilized in oral sustained-release products. The selection, optimization of drug:resin ratio and particle size, together with a summary of commonly occurring commercial sustained-release products are discussed. Ion-exchange resins have also been used in topical products for local application to the skin, including those where drug flux is controlled by a differential electrical current (ionotophoretic delivery). General applicability of ion-exchange resins, including ophthalmic delivery, nasal delivery, use as drugs in their own right (e.g., colestyramine, formerly referred to as cholestyramine), as well as measuring gastrointestinal transit times, are discussed. Finally, pharmaceutical monographs for ion-exchange resins are reviewed.
Pomahacova, Renata; Zamboryova, Jana; Paterova, Petra; Fiklik, Karel; Cerna, Zdenka; Lad, Vaclav; Skalicka, Eva; Huml, Michal; Sykora, Josef
2018-06-07
The prevalence of autoimmune thyroiditis (AIT), as the most common autoimmune disease (AD) and papillary thyroid cancer (PTC) is steadily rising in children. The aim of this study was to determine the coexistence of other AD and thyroid carcinoma (TC) in AIT. The cross-sectional study conducted at a tertiary center comprised AIT children (< 19 years). Data on age/sex, thyroid function and ultrasound, autoantibodies, associated AD, familial occurence of AD and the occurence of TC for each child were collected. In total, 231 eligible patients (77% females) were included. The most common onset (66%) was during adolescence. At onset, hypothyroidism was detected in 59.3%; hashitoxicosis in 1.3%. The positivity of both autoantibodies was present in 60.6%, the negativity was in 3,5%. We confirmed a high frequency (44.6%) of AD with AIT predominance in parents and/or grandparents of patients and in siblings (7.4%). 15.2% had at least 1 comorbid AD, of which type 1 diabetes mellitus was the most common (8.5%). Over a period of 7 years TC was diagnosed in 16 patients (mean age 13.5 years) with predominance of PTC in 15 (94%) patients. AIT had concurrently 69% patients. 56% of patients had metastases (89% in AIT subjects). An invasive PTC was present in 44% (86% in AIT subjects). The prevalence rate of AD in AIT and first-degree relatives is high, and several new associations have been reported. Providers should be aware of comorbidities and TC in AIT as this would help in early diagnoses and timely interventions.
Gales, Jordan M; Prayson, Richard A
2016-02-01
In patients undergoing surgery for temporal lobe epilepsy, hippocampal sclerosis remains the most commonly observed pathology. In addition to hippocampal sclerosis, 5% to 30% of these resections on magnetic resonance imaging contain a second independently epileptogenic lesion, commonly referred to as dual pathology. A second etiology of seizure activity, as seen in dual pathology, may serve as an important cause of treatment failure in striving for post-operative seizure control. Dual pathology, consisting of hippocampal sclerosis and a remote infarct of the adjacent cortex, has been rarely reported. Cases of pathologically confirmed hippocampal sclerosis diagnosed between January 2000 and December 2012 (n = 349) were reviewed, and 7 cases of coexistent infarct (2%) formed the study group. Seven individuals (mean age, 29years; range, 5-47 years) with a mean epilepsy duration of 12.5years (3.3-25 years) and a mean pre-surgery frequency of 15 seizures per week (range, 0.5-56 seizures/week) were followed up postoperatively for a mean duration of 64months (range, 3-137 months). Pathologically, the most common form of hippocampal sclerosis observed was International League against Epilepsy type Ib or severe variant (n = 4). Four of the six individuals with post-surgery follow-up were seizure free at last encounter. The reported incidence of dual pathology, including hippocampal sclerosis and remote infarct, is low (2% in the present study) but may indicate a slightly increased risk of developing hippocampal sclerosis in the setting of a remote infarct. Surgical intervention for such cases anecdotally appears effective in achieving seizure control. Copyright © 2015 Elsevier Inc. All rights reserved.
Fogel, Mark A.; Li, Christine; Elci, Okan U.; Pawlowski, Tom; Schwab, Peter J.; Wilson, Felice; Nicolson, Susan C.; Montenegro, Lisa M.; Diaz, Laura; Spray, Thomas L.; Gaynor, J William; Fuller, Stephanie; Mascio, Christopher; Keller, Marc S.; Harris, Matthew A.; Whitehead, Kevin K.; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J.
2017-01-01
Background Single ventricle patients experience a high rate of brain injury and adverse neurodevelopmental outcome, however, the incidence of brain abnormalities throughout surgical reconstruction and its relationship with cerebral blood flow, oxygen delivery and carbon dioxide reactivity remains unknown. Methods Single ventricle patients were studied with MRI scans immediately prior to bidirectional Glenn (pre-BDG), prior to Fontan and then 3–9 months after Fontan reconstruction. Results One hundred and sixty eight consecutive subjects recruited into the project underwent 235 scans: 63 pre-BDG (mean age 4.8+1.7 months), 118 BDG (2.9+1.4 years) and 54 after Fontan (2.4+1.0 years). Non-acute ischemic white matter changes on T2 weighted imaging, focal tissue loss, and ventriculomegaly were all more commonly detected in BDG and Fontans compared to pre-BDG (P<0.05). BDG patients has significantly higher CBF than Fontan patients. The odds of discovering brain injury adjusting for surgical stage as well as 2 or more co-existing lesions within a patient all decreased (63–75% and 44% respectively) with increasing amount of cerebral blood flow (P<0.05). In general, there was no association of oxygen delivery (with the exception of ventriculomegaly in the BDG group) or carbon dioxide reactivity with neurological injury. Conclusion Significant brain abnormalities are commonly present in single ventricle patients and detection of these lesions increase as children progress through staged surgical reconstruction with multiple co-existing lesions more common earlier than later. In addition, this study demonstrated that BDG patients had greater CBF than Fontan patients and that there exists an inverse association of various indices of CBF with these brain lesions, however, CO2 reactivity, oxygen delivery (with one exception) were not associated with brain lesion development. PMID:28031423
Khan, Fahmi Yousef; Abu-Khattab, Mohammed; Baagar, Khalid; Mohamed, Shehab Fareed; Elgendy, Islam; Anand, Deshmukh; Malallah, Hani; Sanjay, Doiphode
2013-07-01
The aim of this retrospective study was to determine the epidemiological and clinical characteristics, coexisting conditions, causative organisms, and outcomes of all adult patients 15 years of age or older who had definite septic arthritis at Hamad General Hospital, Qatar, from 2006 to 2011. During this period, 56 patients were diagnosed with septic arthritis (mean age ± SD, 49.0 ± 16.6 years). In 53 of 56 (94.6%) patients, arthritis was diagnosed in a single joint, while polyarthritis was diagnosed in 3 of 56 (5.4%) patients; the most commonly involved joint was the knee (40 of 59 joints, 67.7%). The most frequent coexisting condition was diabetes mellitus (24 of 56 patients, 42.8%). Joint pain and restriction of movement were reported by all patients. Gram-positive bacteria accounted for 36 of all 57 (63.0%) isolated microorganisms, and Staphylococcus aureus was the most common pathogen (20 of 57 microorganisms, 35.0%). Three cases of tuberculous arthritis were seen. The most favored antibiotic combinations were cloxacillin/ciprofloxacin, cefazolin/ciprofloxacin, and vancomycin/ciprofloxacin. Repeated needle aspiration, open joint drainage, and arthroscopic techniques were performed in 18 (32.1%), 22 (39.3%), and 11 (19.6%) of the 56 patients, respectively. The 30-day mortality was 3.6%, and the remaining patients showed clinical improvement upon discharge. In conclusion, there was no specific sign or symptom for diagnosing septic arthritis. Isolation of bacteria from the synovial fluid confirmed the diagnosis, and S. aureus and streptococci were the most common pathogens isolated. Prompt treatment with appropriate antibiotics and synovial drainage are mandatory to improve the outcome.
LGI1, CASPR2 and related antibodies: a molecular evolution of the phenotypes
Binks, Sophie N M; Klein, Christopher J; Waters, Patrick; Pittock, Sean J; Irani, Sarosh R
2018-01-01
Recent biochemical observations have helped redefine antigenic components within the voltage-gated potassium channel (VGKC) complex. The related autoantibodies may be now divided into likely pathogenic entities, which target the extracellular domains of leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-like 2 (CASPR2), and species that target intracellular neuronal components and are likely non-pathogenic. This distinction has enhanced clinical practice as direct determination of LGI1 and CASPR2 antibodies offers optimal sensitivity and specificity. In this review, we describe and compare the clinical features associated with pathogenic LGI1 and CASPR2 antibodies, illustrate emerging laboratory techniques for antibody determination and describe the immunological mechanisms that may mediate antibody-induced pathology. We highlight marked clinical overlaps between patients with either LGI1 or CASPR2 antibodies that include frequent focal seizures, prominent amnesia, dysautonomia, neuromyotonia and neuropathic pain. Although occurring at differing rates, these commonalities are striking and only faciobrachial dystonic seizures reliably differentiate these two conditions. Furthermore, the coexistence of both LGI1 and CASPR2 antibodies in an individual occurs surprisingly frequently. Patients with either antibody respond well to immunotherapies, although systematic studies are required to determine the magnitude of the effect beyond placebo. Finally, data have suggested that CASPR2 and LGI1 modulation via genetic or autoimmune mechanisms may share common intermediate molecules. Taken together, the biochemical distinction of antigenic targets has led to important clinical advances for patient care. However, the striking syndrome similarities, coexistence of two otherwise rare antibodies and molecular insights suggest the VGKC complex may yet be a common functional effector of antibody action. Hence, we argue for a molecular evolution alongside a clinical and phenotypic re-evaluation. PMID:29055902
Legg-Calvé-Perthes disease in a child with osteopetrosis
Sims, Alex L.; Barwick, Thomas W.; Montgomery, Richard J.
2011-01-01
Osteopetrosis is a rare inherited disorder of bone causing increased bone density. Legg-Calvé-Perthes disease (LCPD), by contrast, is a more common idiopathic condition leading to variable avascular necrosis of the immature femoral head. We present a case of a 5-year-old boy presenting with these co-morbidities. We have found only one previous reference suggesting these two conditions can coexist in the literature. We discuss the basic principles of management of this interesting case. PMID:24765380
Memory reconsolidation and psychotherapeutic process.
Liberzon, Israel; Javanbakht, Arash
2015-01-01
Lane et al. propose a heuristic model in which distinct, and seemingly irreconcilable, therapies can coexist. Authors postulate that memory reconsolidation is a key common neurobiological process mediating the therapeutic effects. This conceptualization raises a set of important questions regarding neuroscience and translational aspects of fear memory reconsolidation. We discuss the implications of the target article's memory reconsolidation model in the development of more effective interventions, and in the identification of less effective, or potentially harmful approaches, as well as concepts of contextualization, optimal arousal, and combined therapy.
Obsessive-compulsive personality disorder and behavioral disinhibition.
Villemarette-Pittman, Nicole R; Stanford, Matthew S; Greve, Kevin W; Houston, Rebecca J; Mathias, Charles W
2004-01-01
Although obsessive-compulsive personality disorder (OCPD) is an Axis II diagnosis that is not commonly associated with behavioral disinhibition, the literature contains reports of occasional explosive aggressive outbursts. Existing explanations of OCPD etiology do not address the coexistence of compulsive and impulsive features witnessed in some subpopulations of patients. In this study, the authors present a compensatory theory of OCPD in an effort to explain clinical observations of an unexpectedly large number of OCPD diagnoses among patients clinic referred and self-referred for aggression problems.
2013-11-19
CAPE CANAVERAL, Fla. -- A snake becomes part of the diet of a red-tailed hawk, hunting near the Headquarters Building on NASA's Kennedy Space Center in Florida. In the United States, the red-tailed hawk is commonly called a "chicken hawk." Kennedy coexists with the Merritt Island National Wildlife Refuge, which was established in 1963 as an overlay of the center. The 140,000-acre refuge is habitat to more than 320 species of birds. For more information, visit http://www.fws.gov/merrittisland/. Photo credit: NASA/Tony Gray
O’Meara, Wendy Prudhomme; Holland, Thomas L.; Armstrong, Janice
2017-01-01
Introduction The clinical features of UTI in young children may not localize to the urinary tract and closely resemble other febrile illnesses. In malaria endemic areas, a child presenting with fever is often treated presumptively for malaria without investigation for UTI. Delayed or inadequate treatment of UTI increases the risk of bacteremia and renal scarring in young children and subsequently complications as hypertension and end stage renal disease in adulthood. Methods A cross-sectional study was carried out in a hospital in western Kenya. Inpatients and outpatients 2 months to five years with axillary temperature ≥37.5°C and no antibiotic use in the previous week were enrolled between September 2012 and April 2013. Urine dipstick tests, microscopy, and cultures were done and susceptibility patterns to commonly prescribed antibiotics established. UTI was defined as presence of pyuria (a positive urine dipstick or microscopy test) plus a positive urine culture. Results A total of 260 subjects were recruited; 45.8% were female and the median age was 25months (IQR: 13, 43.5). The overall prevalence of UTI was 11.9%. Inpatients had a higher prevalence compared to outpatients (17.9% v 7.8%, p = 0.027). UTI co-existed with malaria but the association was not significant (OR 0.80, p = 0.570). The most common organisms isolated were Escherichia coli (64.5%) and Staphylococcus aureus (12.9%) and were sensitive to ciproflaxin, cefuroxime, ceftriaxone, gentamycin and nitrofurantoin but largely resistant to more commonly used antibiotics such as ampicillin (0%), amoxicillin (16.7%), cotrimoxazole (16.7%) and amoxicillin-clavulinate (25%). Conclusion Our study demonstrates UTI contributes significantly to the burden of febrile illness in young children and often co-exists with other infections. Multi-drug resistant organisms are common therefore choice of antimicrobial therapy should be based on local sensitivity pattern. PMID:28323886
Masika, Wechuli Geoffrey; O'Meara, Wendy Prudhomme; Holland, Thomas L; Armstrong, Janice
2017-01-01
The clinical features of UTI in young children may not localize to the urinary tract and closely resemble other febrile illnesses. In malaria endemic areas, a child presenting with fever is often treated presumptively for malaria without investigation for UTI. Delayed or inadequate treatment of UTI increases the risk of bacteremia and renal scarring in young children and subsequently complications as hypertension and end stage renal disease in adulthood. A cross-sectional study was carried out in a hospital in western Kenya. Inpatients and outpatients 2 months to five years with axillary temperature ≥37.5°C and no antibiotic use in the previous week were enrolled between September 2012 and April 2013. Urine dipstick tests, microscopy, and cultures were done and susceptibility patterns to commonly prescribed antibiotics established. UTI was defined as presence of pyuria (a positive urine dipstick or microscopy test) plus a positive urine culture. A total of 260 subjects were recruited; 45.8% were female and the median age was 25months (IQR: 13, 43.5). The overall prevalence of UTI was 11.9%. Inpatients had a higher prevalence compared to outpatients (17.9% v 7.8%, p = 0.027). UTI co-existed with malaria but the association was not significant (OR 0.80, p = 0.570). The most common organisms isolated were Escherichia coli (64.5%) and Staphylococcus aureus (12.9%) and were sensitive to ciproflaxin, cefuroxime, ceftriaxone, gentamycin and nitrofurantoin but largely resistant to more commonly used antibiotics such as ampicillin (0%), amoxicillin (16.7%), cotrimoxazole (16.7%) and amoxicillin-clavulinate (25%). Our study demonstrates UTI contributes significantly to the burden of febrile illness in young children and often co-exists with other infections. Multi-drug resistant organisms are common therefore choice of antimicrobial therapy should be based on local sensitivity pattern.
Markinson, Bryan C; Caldwell, Bryan D
2015-04-13
We sought to evaluate the efficacy of efinaconazole topical solution, 10%, in patients with onychomycosis and coexisting tinea pedis. We analyzed 1,655 patients, aged 18 to 70 years, randomized (3:1) to receive efinaconazole topical solution, 10%, or vehicle from two identical multicenter, double-blind, vehicle-controlled 48-week studies evaluating safety and efficacy. The primary end point was complete cure rate (0% clinical involvement of the target toenail and negative potassium hydroxide examination and fungal culture findings) at week 52. Three groups were compared: patients with onychomycosis and coexisting interdigital tinea pedis on-study (treated or left untreated) and those with no coexisting tinea pedis. Treatment with efinaconazole topical solution, 10%, was significantly more effective than vehicle use irrespective of the coexistence of tinea pedis or its treatment. Overall, 352 patients with onychomycosis (21.3%) had coexisting interdigital tinea pedis at baseline, with 215 of these patients (61.1%) receiving investigator-approved topical antifungal agents for their tinea pedis in addition to their randomized onychomycosis treatment. At week 52, efinaconazole complete cure rates of 29.4% were reported in patients with onychomycosis when coexisting tinea pedis was treated compared with 16.1% when coexisting tinea pedis was not treated. Both cure rates were significant compared with vehicle (P = .003 and .045, respectively), and in the latter subgroup, no patients treated with vehicle achieved a complete cure. Treatment of coexisting tinea pedis in patients with onychomycosis enhances the efficacy of once-daily topical treatment with efinaconazole topical solution, 10%.
Markinson, Bryan; Caldwell, Bryan
2015-09-01
We sought to evaluate the efficacy of efinaconazole topical solution, 10%, in patients with onychomycosis and coexisting tinea pedis. We analyzed 1,655 patients, aged 18 to 70 years, randomized (3:1) to receive efinaconazole topical solution, 10%, or vehicle from two identical multicenter, double-blind, vehicle-controlled 48-week studies evaluating safety and efficacy. The primary end point was complete cure rate (0% clinical involvement of the target toenail and negative potassium hydroxide examination and fungal culture findings) at week 52. Three groups were compared: patients with onychomycosis and coexisting interdigital tinea pedis on-study (treated or left untreated) and those with no coexisting tinea pedis. Treatment with efinaconazole topical solution, 10%, was significantly more effective than vehicle use irrespective of the coexistence of tinea pedis or its treatment. Overall, 352 patients with onychomycosis (21.3%) had coexisting interdigital tinea pedis, with 215 of these patients (61.1%) receiving investigator-approved topical antifungal agents for their tinea pedis in addition to their randomized onychomycosis treatment. At week 52, efinaconazole complete cure rates of 29.4% were reported in patients with onychomycosis when coexisting tinea pedis was treated compared with 16.1% when coexisting tinea pedis was not treated. Both cure rates were significant compared with vehicle (P = .003 and .045, respectively), and in the latter subgroup, no patients treated with vehicle achieved a complete cure. Treatment of coexisting tinea pedis in patients with onychomycosis enhances the efficacy of once-daily topical treatment with efinaconazole topical solution, 10%.
Szilágyi, András; Zachar, István; Szathmáry, Eörs
2013-01-01
Models of competitive template replication, although basic for replicator dynamics and primordial evolution, have not yet taken different sequences explicitly into account, neither have they analyzed the effect of resource partitioning (feeding on different resources) on coexistence. Here we show by analytical and numerical calculations that Gause's principle of competitive exclusion holds for template replicators if resources (nucleotides) affect growth linearly and coexistence is at fixed point attractors. Cases of complementary or homologous pairing between building blocks with parallel or antiparallel strands show no deviation from the rule that the nucleotide compositions of stably coexisting species must be different and there cannot be more coexisting replicator species than nucleotide types. Besides this overlooked mechanism of template coexistence we show also that interesting sequence effects prevail as parts of sequences that are copied earlier affect coexistence more strongly due to the higher concentration of the corresponding replication intermediates. Template and copy always count as one species due their constraint of strict stoichiometric coupling. Stability of fixed-point coexistence tends to decrease with the length of sequences, although this effect is unlikely to be detrimental for sequences below 100 nucleotides. In sum, resource partitioning (niche differentiation) is the default form of competitive coexistence for replicating templates feeding on a cocktail of different nucleotides, as it may have been the case in the RNA world. Our analysis of different pairing and strand orientation schemes is relevant for artificial and potentially astrobiological genetics. PMID:23990769
On the evidence for species coexistence: a critique of the coexistence program.
Siepielski, Adam M; McPeek, Mark A
2010-11-01
A major challenge in ecology is to understand how the millions of species on Earth are organized into biological communities. Mechanisms promoting coexistence are one such class of organizing processes, which allow multiple species to persist in the same trophic level of a given web of species interactions. If some mechanism promotes the coexistence of two or more species, each species must be able to increase when it is rare and the others are at their typical abundances; this invasibility criterion is fundamental evidence for species coexistence regardless of the mechanism. In an attempt to evaluate the level of empirical support for coexistence mechanisms in nature, we surveyed the literature for empirical studies of coexistence at a local scale (i.e., species found living together in one place) to determine whether these studies satisfied the invasibility criterion. In our survey, only seven of 323 studies that drew conclusions about species coexistence evaluated invasibility in some way in either observational or experimental studies. In addition, only three other studies evaluated necessary but not sufficient conditions for invasibility (i.e., negative density dependence and a trade-off in performance that influences population regulation). These results indicate that, while species coexistence is a prevalent assumption for why species are able to live together in one place, critical empirical tests of this fundamental assumption of community structure are rarely performed. These tests are central to developing a more robust understanding of the relative contributions of both deterministic and stochastic processes structuring biological communities.
Long-Term Coexistence of Rotifer Cryptic Species
Serra, Manuel; Gómez, Africa
2011-01-01
Despite their high morphological similarity, cryptic species often coexist in aquatic habitats presenting a challenge in the framework of niche differentiation theory and coexistence mechanisms. Here we use a rotifer species complex inhabiting highly unpredictable and fluctuating salt lakes to gain insights into the mechanisms involved in stable coexistence in cryptic species. We combined molecular barcoding surveys of planktonic populations and paleogenetic analysis of diapausing eggs to reconstruct the current and historical coexistence dynamics of two highly morphologically similar rotifer species, B. plicatilis and B. manjavacas. In addition, we carried out laboratory experiments using clones isolated from eight lakes where both species coexist to explore their clonal growth responses to salinity, a challenging, highly variable and unpredictable condition in Mediterranean salt lakes. We show that both species have co-occurred in a stable way in one lake, with population fluctuations in which no species was permanently excluded. The seasonal occurrence patterns of the plankton in two lakes agree with laboratory experiments showing that both species differ in their optimal salinity. These results suggest that stable species coexistence is mediated by differential responses to salinity and its fluctuating regime. We discuss the role of fluctuating salinity and a persistent diapausing egg banks as a mechanism for species coexistence in accordance with the ‘storage effect’. PMID:21738691
NASA Astrophysics Data System (ADS)
Tse, Mei-Yan; Tsang, Ming-Kiu; Wong, Yuen-Ting; Chan, Yi-Lok; Hao, Jianhua
2016-07-01
We have investigated the optical and dielectric properties of rutile TiO2 doped with Nb and Er, i.e., (Er0.5Nb0.5)xTi1-xO2. The up/downconversion photoluminescence was observed in the visible and near-infrared region from the materials under 980 nm laser diode excitation. The upconversion emissions are attributed to the energy transfer between Er ions in the excited states. Moreover, the dielectric measurements indicate that the fabricated materials simultaneously present colossal permittivity properties with relatively low dielectric loss. Our work demonstrates the coexistence of both interesting luminescence and attractive dielectric characteristics in (Er+Nb) co-doped TiO2, showing the potential for multifunctional applications.
Vasudevan, Subramanyan; Lakshmi, Jothinathan; Jayaraj, Jeganathan; Sozhan, Ganapathy
2009-05-30
The present study provides an electrocoagulation process for the remediation of phosphate-contaminated water using aluminium, aluminium alloy and mild steel as the anodes and stainless steel as the cathode. The various parameters like effect of anode materials, effect of pH, concentration of phosphate, current density, temperature and co-existing ions, and so forth, and the adsorption capacity was evaluated using both Freundlich and Langmuir isotherm models. The adsorption of phosphate preferably fitting the Langmuir adsorption isotherm suggests monolayer coverage of adsorbed molecules. The results showed that the maximum removal efficiency of 99% was achieved with aluminium alloy anode at a current density of 0.2 A dm(-2), at a pH of 7.0. The adsorption process follows second-order kinetics.
Separation of glycosidic catiomers by TWIM-MS using CO2 as a drift gas.
Bataglion, Giovana A; Souza, Gustavo Henrique Martins Ferreira; Heerdt, Gabriel; Morgon, Nelson H; Dutra, José Diogo Lisboa; Freire, Ricardo Oliveira; Eberlin, Marcos N; Tata, Alessandra
2015-02-01
Traveling wave ion mobility mass spectrometry (TWIM-MS) is shown to be able to separate and characterize several isomeric forms of diterpene glycosides stevioside (Stv) and rebaudioside A (RebA) that are cationized by Na(+) and K(+) at different sites. Determination and characterization of these coexisting isomeric species, herein termed catiomers, arising from cationization at different and highly competitive coordinating sites, is particularly challenging for glycosides. To achieve this goal, the advantage of using CO2 as a more massive and polarizable drift gas, over N2, was demonstrated. Post-TWIM-MS/MS experiments were used to confirm the separation. Optimization of the possible geometries and cross-sectional calculations for mobility peak assignments were also performed. Copyright © 2015 John Wiley & Sons, Ltd.
NASA Astrophysics Data System (ADS)
Li, Hongqi; Zheng, Tao; Zhao, Yong; Xu, Zhenxiang; Dai, Xuhang; Shao, Zhiyu
2018-03-01
A spiropyran-appended polysiloxane (SP-Si) was synthesized and characterized. The pH-responsive behavior of SP-Si was investigated. It was found that with the decrease of the pH of SP-Si solution the intensity of the absorption peak at 440 nm increased and the color of SP-Si solution turned from colorless to yellow gradually. The polymer serves as chemosensor for colorimetric detection of Ag+ and Fe3+ ions. Addition of Ag+ and Fe3+ ions to SP-Si solution induced color change from colorless to brown and earthy yellow, respectively. Sensing of Ag+ ions by SP-Si was not affected by common competitive metal ions except Hg2+ ions. Based on the transformation from colorless SP-Si solution with negligible absorption at 440 nm to brown SP-Si/Ag+ showing extremely strong absorption at 440 nm by addition of Ag+ ions and subsequent transformation from brown to colorless SP-Si/Ag+/Hg2+ with relatively weak absorption at 440 nm after addition of 1 equivalent of Hg2+ ions, SP-Si/Ag+ system serves as a dual colorimetric and spectroscopic probe for highly selective and sensitive detection of Hg2+ ions. The selective detection of Fe3+ ions by SP-Si is not interfered by common competitive metal ions including Na+, K+, Li+, Hg2+, Ni2+, Fe2+, Zn2+, Co2+, Sr2+, Cu2+, Al3+, Ce3+ and Cr3+. The detection limit of Ag+ and Fe3+ ions is 1.45 × 10-6 M and 3.52 × 10-6 M, respectively.
Factors Affecting the Production of Aromatic Immonium Ions in MALDI 157 nm Photodissociation Studies
NASA Astrophysics Data System (ADS)
DeGraan-Weber, Nick; Ashley, Daniel C.; Keijzer, Karlijn; Baik, Mu-Hyun; Reilly, James P.
2016-05-01
Immonium ions are commonly observed in the high energy fragmentation of peptide ions. In a MALDI-TOF/TOF mass spectrometer, singly charged peptides photofragmented with 157 nm VUV light yield a copious abundance of immonium ions, especially those from aromatic residues. However, their intensities may vary from one peptide to another. In this work, the effect of varying amino acid position, peptide length, and peptide composition on immonium ion yield is investigated. Internal immonium ions are found to have the strongest intensity, whereas immonium ions arising from C-terminal residues are the weakest. Peptide length and competition among residues also strongly influence the immonium ion production. Quantum calculations provide insights about immonium ion structures and the fragment ion conformations that promote or inhibit immonium ion formation.
The role of ion optics modeling in the design and development of ion mobility spectrometers
NASA Astrophysics Data System (ADS)
Griffin, Matthew T.
2005-05-01
Detection of trace gases by ion mobility spectroscopy (IMS) has become common in recent years. In fact, IMS devices are the most commonly deployed military devices for the detection of classical chemical warfare agents (CWA). IMS devices are protecting the homeland by aiding first responders in the identification of toxic industrial chemicals (TICs) and providing explosive and narcotic screening systems. Spurred by the asymmetric threat posed by new threat agents and the ever expanding list of toxic chemicals, research in the development, improvement, and optimization of IMS systems has increased. Much of the research is focused on increasing the sensitivity and selectivity of IMS systems. Ion optics is a large area of study in the field of mass spectrometry, but has been mostly overlooked in the design and development of IMS systems. Ion optics provides insight into particle trajectories, duty cycle, and efficiency of these systems. This paper will outline the role that ion optics can have in the development of IMS systems and introduce the trade space for traditional IMS as well as differential mobility spectroscopy.
New insights into the electrochemical desorption of alkanethiol SAMs on gold
Pensa, Evangelina; Vericat, Carolina; Grumelli, Doris; Salvarezza, Roberto C.; Park, Sung Hyun; Longo, Gabriel S.; Szleifer, Igal
2012-01-01
A combination of Polarization Modulation Infrared Reflection Absorption Spectroscopy (PMIRRAS) under electrochemical control, Electrochemical Scanning Tunneling Microscopy (ECSTM) and Molecular Dynamics (MD) simulations has been used to shed light on the reductive desorption process of dodecanethiol (C12) and octadecanethiol (C18) SAMs on gold in aqueous electrolytes. Experimental PMIRRAS, ECSTM and MD simulations data for C12 desorption are consistent with formation of randomly distributed micellar aggregates stabilized by Na+ ions, coexisting with a lying-down phase of molecules. The analysis of pit and Au island coverage before and after desorption is consistent with the thiolate-Au adatoms models. On the other hand, PMIRRAS and MD data for C18 indicate that the desorbed alkanethiolates adopt a Na+ ion-stabilized bilayer of interdigitated alkanethiolates, with no evidence of lying down molecules. MD simulations also show that both the degree of order and tilt angle of the desorbed alkanethiolates change with the surface charge on the metal, going from bilayers to micelles. These results demonstrate the complexity of the alkanethiol desorption in the presence of water and the fact that chain length and counterions play a key role in a complex structure. PMID:22870508
NASA Astrophysics Data System (ADS)
Hua, Yani; Xiao, Juan; Zhang, Qinqin; Cui, Chang; Wang, Chuan
2018-04-01
A new magnetic nano-adsorbent, polycatechol modified Fe3O4 magnetic nanoparticles (Fe3O4/PCC MNPs) were prepared by a facile chemical coprecipitation method using iron salts and catechol solution as precursors. Fe3O4/PCC MNPs owned negatively charged surface with oxygen-containing groups and showed a strong adsorption capacity and fast adsorption rates for the removal of cationic dyes in water. The adsorption capacity of methylene blue (MB), cationic turquoise blue GB (GB), malachite green (MG), crystal violet (CV) and cationic pink FG (FG) were 60.06 mg g- 1, 70.97 mg g- 1, 66.84 mg g- 1, 66.01 mg g- 1 and 50.27 mg g- 1, respectively. The adsorption mechanism was proposed by the analyses of the adsorption isotherms and adsorption kinetics of cationic dyes on Fe3O4/PCC MNPs. Moreover, the cationic dyes adsorbed on the MNPs as a function of contact time, pH value, temperature, coexisting cationic ions and ion strength were also investigated. These results suggested that the Fe3O4/PCC MNPs is promising to be used as a magnetic adsorbent for selective adsorption of cationic dyes in wastewater treatment.
Zhou, Yong-Ning; Yue, Ji-Li; Hu, Enyuan; ...
2016-08-08
Using fast time-resolved in situ X-ray diffraction, charge-rate dependent phase transition processes of layer structured cathode material LiNi 1/3Mn 1/3Co 1/3O 2 for lithium-ion batteries are studied. During first charge, intermediate phases emerge at high rates of 10C, 30C, and 60C, but not at low rates of 0.1C and 1C. These intermediate phases can be continuously observed during relaxation after the charging current is switched off. After half-way charging at high rate, sample studied by scanning transmission electron microscopy shows Li-rich and Li-poor phases' coexistence with tetrahedral occupation of Li in Li-poor phase. Also, the high rate induced overpotential ismore » thought to be the driving force for the formation of this intermediate Li-poor phase. The in situ quick X-ray absorption results show that the oxidation of Ni accelerates with increasing charging rate and the Ni 4+ state can be reached at the end of charge with 30C rate. Finally, these results give new insights in the understanding of the layered cathodes during high-rate charging.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sandoval-Paz, M.G., E-mail: myrnasandoval@udec.cl; Rodríguez, C.A.; Porcile-Saavedra, P.F.
Copper (I) selenide thin films with orthorhombic and cubic structure were deposited on glass substrates by using the chemical bath deposition technique. The effects of the solution pH on the films growth and subsequently the structural, optical and electrical properties of the films were studied. Films with orthorhombic structure were obtained from baths wherein both metal complex and hydroxide coexist; while films with cubic structure were obtained from baths where the metal hydroxide there is no present. The structural modifications are accompanied by changes in bandgap energy, morphology and electrical resistivity of the films. - Graphical abstract: “Study of themore » crystallographic phase change on copper (I) selenide thin films prepared through chemical bath deposition by varying the pH of the solution” by M. G. Sandoval-Paz, C. A. Rodríguez, P. F. Porcile-Saavedra, C. Trejo-Cruz. Display Omitted - Highlights: • Copper (I) selenide thin films were obtained by chemical bath deposition. • Orthorhombic to cubic phase change was induced by varying the reaction solution pH. • Orthorhombic phase is obtained mainly from a hydroxides cluster mechanism. • Cubic phase is obtained mainly from an ion by ion mechanism. • Structural, optical and electrical properties are presented as a function of pH.« less
Manzanilla-Granados, Héctor M; Saint-Martín, Humberto; Fuentes-Azcatl, Raúl; Alejandre, José
2015-07-02
The solubility of NaCl, an equilibrium between a saturated solution of ions and a solid with a crystalline structure, was obtained from molecular dynamics simulations using the SPC/E and TIP4P-Ew water models. Four initial setups on supersaturated systems were tested on sodium chloride (NaCl) solutions to determine the equilibrium conditions and computational performance: (1) an ionic solution confined between two crystal plates of periodic NaCl, (2) a solution with all the ions initially distributed randomly, (3) a nanocrystal immersed in pure water, and (4) a nanocrystal immersed in an ionic solution. In some cases, the equilibration of the system can take several microseconds. The results from this work showed that the solubility of NaCl was the same, within simulation error, for the four setups, and in agreement with previously reported values from simulations with the setup (1). The system of a nanocrystal immersed in supersaturated solution was found to equilibrate faster than others. In agreement with laser-Doppler droplet measurements, at equilibrium with the solution the crystals in all the setups had a slight positive charge.
NASA Technical Reports Server (NTRS)
McKeegan, Kevin D.
1998-01-01
NASA NAGW-4112 has supported development of the CAMECA ims 1270 ion microprobe at UCLA for applications in cosmochemistry. The instrument has been brought to an operational status and techniques developed for accurate, precise microbeam analysis of oxygen isotope ratios in polished thin-sections. We made the first oxygen isotopic (delta(18)O and delta(17)O) measurements of rare mafic silicates in the most chemically primitive meteorites, the a chondrites (Leshin et al., 1997). The results have implications for both high temperature processing in the nebula and low-T aqueous alteration on the CI asteroid. We have performed measurements of oxygen isotopic compositions of magnetite and co-existing olivine from carbonaceous (Choi et al., 1997) and unequilibrated ordinary chondrites (Choi et al., in press). This work has identified a significant new oxygen isotope reservoir in the early solar system: water characterized by a very high Delta(17)) value of approx. 5 % per thousand. We have determined the spatial distributions of oxygen isotopic anomalies in all major mineral phases of a type B CAI from Allende. We have also studied an unusual fractionated CAI from Leoville and made the first oxygen isotopic measurements in rare CAIs from ordinary chondrites.
PLASMA TURBULENCE AND KINETIC INSTABILITIES AT ION SCALES IN THE EXPANDING SOLAR WIND
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hellinger, Petr; Trávnícek, Pavel M.; Matteini, Lorenzo
The relationship between a decaying strong turbulence and kinetic instabilities in a slowly expanding plasma is investigated using two-dimensional (2D) hybrid expanding box simulations. We impose an initial ambient magnetic field perpendicular to the simulation box, and we start with a spectrum of large-scale, linearly polarized, random-phase Alfvénic fluctuations that have energy equipartition between kinetic and magnetic fluctuations and vanishing correlation between the two fields. A turbulent cascade rapidly develops; magnetic field fluctuations exhibit a power-law spectrum at large scales and a steeper spectrum at ion scales. The turbulent cascade leads to an overall anisotropic proton heating, protons are heatedmore » in the perpendicular direction, and, initially, also in the parallel direction. The imposed expansion leads to generation of a large parallel proton temperature anisotropy which is at later stages partly reduced by turbulence. The turbulent heating is not sufficient to overcome the expansion-driven perpendicular cooling and the system eventually drives the oblique firehose instability in a form of localized nonlinear wave packets which efficiently reduce the parallel temperature anisotropy. This work demonstrates that kinetic instabilities may coexist with strong plasma turbulence even in a constrained 2D regime.« less
Abdolmohammad-Zadeh, Hossein; Tavarid, Keyvan; Talleb, Zeynab
2012-01-01
Nanostructured nickel-aluminum-zirconium ternary layered double hydroxide was successfully applied as a solid-phase extraction sorbent for the separation and pre-concentration of trace levels of iodate in food, environmental and biological samples. An indirect method was used for monitoring of the extracted iodate ions. The method is based on the reaction of the iodate with iodide in acidic solution to produce iodine, which can be spectrophotometrically monitored at 352 nm. The absorbance is directly proportional to the concentration of iodate in the sample. The effect of several parameters such as pH, sample flow rate, amount of nanosorbent, elution conditions, sample volume, and coexisting ions on the recovery was investigated. In the optimum experimental conditions, the limit of detection (3s) and enrichment factor were 0.12 μg mL−1 and 20, respectively. The calibration graph using the preconcentration system was linear in the range of 0.2–2.8 μg mL−1 with a correlation coefficient of 0.998. In order to validate the presented method, a certified reference material, NIST SRM 1549, was also analyzed. PMID:22619590
NASA Astrophysics Data System (ADS)
Willigers, B. J. A.; Baker, J. A.; Krogstad, E. J.; Peate, D. W.
2002-03-01
To evaluate in situ Pb dating by laser ablation multiple-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS), we analysed apatite, sphene, and monazite from Paleoproterozoic metamorphic rocks from West Greenland. Pb isotope ratios were also determined in the National Institute of Standards and Technology (NIST) 610 glass standard and were corrected for mass fractionation by reference to the measured thallium isotope ratio. The NIST 610 glass was used to monitor Pb isotope mass fractionation in the low Tl/Pb accessory minerals. Replicate analyses of the glass (1 to 2 min) yielded ratios with an external reproducibility comparable to conventional analyses of standard reference material 981 by thermal ionisation mass spectrometry (TIMS). Mineral grains were generally analysed with a 100-μm laser beam, although some monazite crystals were analysed at smaller spot sizes (10 and 25 μm). The common Pb isotope ratios required for age calculations were either measured on coexisting plagioclase by LA-MC-ICP-MS or could be ignored, as individual crystals exhibit sufficient Pb isotopic heterogeneity to perform isochron calculations on replicate analyses of single crystals. Mean mineral ages with the 204Pb ion beam measured in the multiplier were as follows: apatite, 1715 ± 23 m.y.; sphene, 1789 ± 11 m.y.; and monazite, 1783 to 1888 m.y., with relative uncertainties on individual monazite ages of <0.2% but highly reproducible age determinations on single monazite crystals (≪1%). Isochron ages calculated from several mineral analyses without assumption of common Pb also yield precise age determinations. Apatite and monazite Pb ages determined by in situ Pb isotope analysis are identical to those determined by conventional TIMS analysis of bulk mineral separates, and the analytical uncertainties of these short laser analyses with no prior mechanical or chemical separation are comparable to those obtained by TIMS. Detailed examination of the sphene in situ age data does, however, show a small discrepancy between the LA-MC-ICP-MS and TIMS ages (˜1% younger). High-resolution mass scans of the sphene during ablation clearly showed several small and as yet unidentified isobaric interferences that overlap with the 207Pb peak at the resolution conditions for measurement of isotope ratios. These might account for the age discrepancy between the LA-MC-ICP-MS and TIMS sphene ages. LA-MC-ICP-MS is a rapid, accurate, and precise method for in situ determination of Pb isotope ratios that can be used for geochronological studies in a manner similar to an ion microprobe, albeit currently at a somewhat degraded spatial resolution. Further modifications to the LA-MC-ICP-MS system, such as improved sensitivity, ion transmission, and LA methodology, may lead to this type of instrument becoming the method of choice for many types of in situ Pb isotope dating.
Various Types of Coexisting Attractors in a New 4D Autonomous Chaotic System
NASA Astrophysics Data System (ADS)
Lai, Qiang; Akgul, Akif; Zhao, Xiao-Wen; Pei, Huiqin
An unique 4D autonomous chaotic system with signum function term is proposed in this paper. The system has four unstable equilibria and various types of coexisting attractors appear. Four-wing and four-scroll strange attractors are observed in the system and they will be broken into two coexisting butterfly attractors and two coexisting double-scroll attractors with the variation of the parameters. Numerical simulation shows that the system has various types of multiple coexisting attractors including two butterfly attractors with four limit cycles, two double-scroll attractors with a limit cycle, four single-scroll strange attractors, four limit cycles with regard to different parameters and initial values. The coexistence of the attractors is determined by the bifurcation diagrams. The chaotic and hyperchaotic properties of the attractors are verified by the Lyapunov exponents. Moreover, we present an electronic circuit to experimentally realize the dynamic behavior of the system.
Liu, Xiaoming; Xie, Weijie; Lü, Ying; Feng, Jingchun; Tang, Xinghua; Lin, Jun; Dai, Yuhua; Xie, Yu; Yan, Liushui
2017-11-20
Up to now, orchestrating the coexistence of Eu 2+ and Eu 3+ activators in a single host lattice has been an extremely difficult task, especially for the appearance of the characteristic emission of Eu 2+ and Eu 3+ in order to generate white light. Nevertheless, here we demonstrate a new Eu 2+ /Eu 3+ coactivated SrAl 3 BO 7 nanocrystalline phosphor with abundant and excellent multichannel luminescence properties. A series of Eu 2+ /Eu 3+ coactivated SrAl 3 BO 7 nanocrystalline phosphors were prepared through a Pechini-type sol-gel method followed by a reduction process. With excitation of UV/NUV light, the prepared SrAl 3 BO 7 :Eu 2+ ,Eu 3+ phosphors show not only the characteristic f-f transitions of Eu 3+ ion ( 5 D J → 7 F J,J' , J, J' = 0-3), but also the 5d → 4f transitions of Eu 2+ ion with comparable intensity from 400 to 700 nm in the whole visible spectral region. The luminescence color of the SrAl 3 BO 7 :Eu 2+ ,Eu 3+ phosphor can be tuned from blue, blue-green, white, and orange to orange-red by changing the excitation wavelength, the overall doping concentration of europium ions (Eu 2+ , Eu 3+ ), and the relative ratio of Eu 2+ to Eu 3+ ions to some extent. A single-phase white-light emission has been realized in SrAl 3 BO 7 :Eu 2+ ,Eu 3+ phosphor. The obtained SrAl 3 BO 7 :Eu 2+ ,Eu 3+ phosphor has potential application in the area of NUV white-light-emitting diodes.
Large-ion lithophile elements delivered by saline fluids to the sub-arc mantle
NASA Astrophysics Data System (ADS)
Kawamoto, Tatsuhiko; Mibe, Kenji; Bureau, Hélène; Reguer, Solenn; Mocuta, Cristian; Kubsky, Stefan; Thiaudière, Dominique; Ono, Shigeaki; Kogiso, Tetsu
2014-12-01
Geochemical signatures of arc basalts can be explained by addition of aqueous fluids, melts, and/or supercritical fluids from the subducting slab to the sub-arc mantle. Partitioning of large-ion lithophile elements between aqueous fluids and melts is crucial as these two liquid phases are present in the sub-arc pressure-temperature conditions. Using a micro-focused synchrotron X-ray beam, in situ X-ray fluorescence (XRF) spectra were obtained from aqueous fluids and haplogranite or jadeite melts at 0.3 to 1.3 GPa and 730°C to 830°C under varied concentrations of (Na, K)Cl (0 to 25 wt.%). Partition coefficients between the aqueous fluids and melts were calculated for Pb, Rb, and Sr ([InlineEquation not available: see fulltext.]). There was a positive correlation between [InlineEquation not available: see fulltext.] values and pressure, as well as [InlineEquation not available: see fulltext.] values and salinity. As compared to the saline fluids with 25 wt.% (Na, K)Cl, the Cl-free aqueous fluids can only dissolve one tenth (Pb, Rb) to one fifth (Sr) of the amount of large-ion lithophile elements when they coexist with the melts. In the systems with 13 to 25 wt.% (Na, K)Cl, [InlineEquation not available: see fulltext.] values were greater than unity, which is indicative of the capacity of such highly saline fluids to effectively transfer Pb and Rb. Enrichment of large-ion lithophile elements such as Pb and Rb in arc basalts relative to mid-oceanic ridge basalts (MORB) has been attributed to mantle source fertilization by aqueous fluids from dehydrating oceanic plates. Such aqueous fluids are likely to contain Cl, although the amount remains to be quantified.
The short range anion-H interaction is the driving force for crystal formation of ions in water.
Alejandre, José; Chapela, Gustavo A; Bresme, Fernando; Hansen, Jean-Pierre
2009-05-07
The crystal formation of NaCl in water is studied by extensive molecular dynamics simulations. Ionic solutions at room temperature and various concentrations are studied using the SPC/E and TIP4P/2005 water models and seven force fields of NaCl. Most force fields of pure NaCl fail to reproduce the experimental density of the crystal, and in solution some favor dissociation at saturated conditions, while others favor crystal formation at low concentration. A new force field of NaCl is proposed, which reproduces the experimental phase diagram in the solid, liquid, and vapor regions. This force field overestimates the solubility of NaCl in water at saturation conditions when used with standard Lorentz-Berthelot combining rules for the ion-water pair potentials. It is shown that precipitation of ions is driven by the short range interaction between Cl-H pairs, a term which is generally missing in the simulation of ionic solutions. The effects of intramolecular flexibility of water on the solubility of NaCl ions are analyzed and is found to be small compared to rigid models. A flexible water model, extending the rigid SPC/E, is proposed, which incorporates Lennard-Jones interactions centered on the hydrogen atoms. This force field gives liquid-vapor coexisting densities and surface tensions in better agreement with experimental data than the rigid SPC/E model. The Cl-H, Na-O, and Cl-O pair distribution functions of the rigid and flexible models agree well with experiment. The predicted concentration dependence of the electric conductivity is in fair agreement with available experimental data.
Canterbury, Jesse D.; Merrihew, Gennifer E.; Goodlett, David R.; MacCoss, Michael J.; Shaffer, Scott A.
2015-01-01
A common strategy in mass spectrometry analyses of complex protein mixtures is to digest the proteins to peptides, separate the peptides by microcapillary liquid chromatography and collect tandem mass spectra (MS/MS) on the eluting, complex peptide mixtures, a process commonly termed “shotgun proteomics”. For years, the most common way of data collection was via data-dependent acquisition (DDA), a process driven by an automated instrument control routine that directs MS/MS acquisition from the highest abundant signals to the lowest, a process often leaving lower abundant signals unanalyzed and therefore unidentified in the experiment. Advances in both instrumentation duty cycle and sensitivity allow DDA to probe to lower peptide abundance and therefore enable mapping proteomes to a more significant depth. An alternative to acquiring data by DDA is by data-independent acquisition (DIA), in which a specified range in m/z is fragmented without regard to prioritization of a precursor ion or its relative abundance in the mass spectrum. As a consequence, DIA acquisition potentially offers more comprehensive analysis of peptides than DDA and in principle can yield tandem mass spectra of all ionized molecules following their conversion to the gas-phase. In this work, we evaluate both DDA and DIA on three different linear ion trap instruments: an LTQ, an LTQ modified in-house with an electrodynamic ion funnel, and an LTQ-Velos. These instruments were chosen as they are representative of both older (LTQ) and newer (LTQ-Velos) ion trap designs i.e., linear ion trap and dual ion traps, respectively, and allow direct comparison of peptide identification using both DDA and DIA analysis. Further, as the LTQ-Velos has an improved “S-lens” ion guide in the high-pressure region to improve ion flux, we found it logical to determine if the former LTQ model could be leveraged by improving sensitivity by modifying with an electrodynamic ion guide of significantly different design to the S-lens. We find that the ion funnel enabled LTQ identifies more proteins in the insoluble fraction of a yeast lysate than the other two instruments in DIA mode, while the faster scanning LTQ-Velos performs better in DDA mode. We explore reasons for these results, including differences in scan speed, source ion optics, and linear ion trap design. PMID:25261218
Jiang, Meng-Jie; Weng, Shan-Shan; Cao, Ying; Li, Xiao-Fen; Wang, Liu-Hong; Xu, Jing-Hong; Yuan, Ying
2015-09-01
Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor in gastrointestinal tracts; however, the synchronous or metachronous coexistence of GIST with additional primary malignancy is not common.Here, we present an unusual case of gastric GIST with metachronous primary lung adenocarcinoma diagnosed during his adjuvant treatment with oral receptor tyrosine kinase inhibitor imatinib mesylate (400 mg daily). After 6-month use of imatinib, the patient suffered from dry cough and dyspnea. Subsequent lung biopsy demonstrated adenocarcinoma with diffuse interstitial changes.Our research emphasizes the possibility of an additional primary tumor with GIST, and reminds the clinicians to strengthen the surveillance of the additional cancer during the follow-up of GIST patients.
Airborne microbial allergens: Impact and risk assessment
DOE Office of Scientific and Technical Information (OSTI.GOV)
Solomon, W.R.
1990-01-01
Despite their evolution in more natural niches, a variety of microorganisms have also successfully colonized man-made interiors. Such adaptable agents require fairly simple carbon and nitrogen sources, in limited amounts, and find these on surfaces and in fluid collections. Available moisture is also a critical permissive factor. Survival and growth indoors are fostered by the presence of stored biogenic materials and by soiling of surfaces with organic films derived from foodstuffs, soaps, volatile hydrocarbons and organic dusts. Commonly, predators such as protozoa, mites, insects and nematodes graze on a variety of established early invaders so that complex mixed populations aremore » common. At the least, bacteria, fungi and their extracellular products regularly coexist on even marginal substrates.« less
Nutraceuticals against Neurodegeneration: A Mechanistic Insight.
Dadhania, Vivekkumar P; Trivedi, Priyanka P; Vikram, Ajit; Tripathi, Durga Nand
2016-01-01
The mechanisms underlying neurodegenerative disorders are complex and multifactorial; however, accumulating evidences suggest few common shared pathways. These common pathways include mitochondrial dysfunction, intracellular Ca2+ overload, oxidative stress and inflammation. Often multiple pathways co-exist, and therefore limit the benefits of therapeutic interventions. Nutraceuticals have recently gained importance owing to their multifaceted effects. These food-based approaches are believed to target multiple pathways in a slow but more physiological manner without causing severe adverse effects. Available information strongly supports the notion that apart from preventing the onset of neuronal damage, nutraceuticals can potentially attenuate the continued progression of neuronal destruction. In this article, we i) review the common pathways involved in the pathogenesis of the toxicants-induced neurotoxicity and neurodegenerative disorders with special emphasis on Alzheimer`s disease (AD), Parkinson`s disease (PD), Huntington`s disease (HD), Multiple sclerosis (MS) and Amyotrophic lateral sclerosis (ALS), and ii) summarize current research advancements on the effects of nutraceuticals against these detrimental pathways.
Nutraceuticals against Neurodegeneration: A Mechanistic Insight
Dadhania, Vivekkumar P.; Trivedi, Priyanka P.; Vikram, Ajit; Tripathi, Durga Nand
2016-01-01
The mechanisms underlying neurodegenerative disorders are complex and multifactorial; however, accumulating evidences suggest few common shared pathways. These common pathways include mitochondrial dysfunction, intracellular Ca2+ overload, oxidative stress and inflammation. Often multiple pathways co-exist, and therefore limit the benefits of therapeutic interventions. Nutraceuticals have recently gained importance owing to their multifaceted effects. These food-based approaches are believed to target multiple pathways in a slow but more physiological manner without causing severe adverse effects. Available information strongly supports the notion that apart from preventing the onset of neuronal damage, nutraceuticals can potentially attenuate the continued progression of neuronal destruction. In this article, we i) review the common pathways involved in the pathogenesis of the toxicants-induced neurotoxicity and neurodegenerative disorders with special emphasis on Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), Multiple sclerosis (MS) and Amyotrophic lateral sclerosis (ALS), and ii) summarize current research advancements on the effects of nutraceuticals against these detrimental pathways. PMID:26725888
Gonzales, Elena; Huamán-Espino, Lucio; Gutiérrez, César; Aparco, Juan Pablo; Pillaca, Jenny
2015-01-01
Characterize anemia in children aged between 12 and 59 months from urban areas in the provinces of Coronel Portillo and Huancavelica in Peru. Cross-sectional study carried out in two stages: a) population-based study to identify children with anemia using multistage probability sampling, and b) characterization of the serum levels of ferritin, vitamin B12, intraerythrocytic folic acid and presence of parasitosis in children with anemia. For the statistical analysis, expansion factors calculated from the sampling plan were applied. The prevalence of anemia was 55.9% in Huancavelica and 36.2% in Coronel Portillo. In Huancavelica, the coexistence of anemia with iron deficiency was 22.8% and anemia with vitamin B12 deficiency was 11%. In Coronel Portillo, the coexistence of anemia with iron deficiency and vitamin B12 deficiency was 15.2% and 29.7%, respectively. The most common types of anemia in Huancavelica were anemia with concurrent parasitosis (50.9%), iron deficiency anemia and parasitosis (12.3%), and iron deficiency alone (6.4%). In Coronel Portillo, it was anemia and parasitosis (54.4%), vitamin B12 deficiency and parasitosis (18.4%), and iron deficiency anemia and parasitosis (6.3%). The prevalence of anemia is higher than the national average, with anemia concurrent with parasitosis and anemia concurrent with two or more causes as the most common type. Consideration should be given to different causes other than iron deficiency in the programs of anemia contol for Peruvian children.
Williams Syndrome and 15q Duplication: Coincidence versus Association.
Khokhar, Aditi; Agarwal, Swashti; Perez-Colon, Sheila
2017-01-01
Williams syndrome is a multisystem disorder caused by contiguous gene deletion in 7q11.23, commonly associated with distinctive facial features, supravalvular aortic stenosis, short stature, idiopathic hypercalcemia, developmental delay, joint laxity, and a friendly personality. The clinical features of 15q11q13 duplication syndrome include autism, mental retardation, ataxia, seizures, developmental delay, and behavioral problems. We report a rare case of a girl with genetically confirmed Williams syndrome and coexisting 15q duplication syndrome. The patient underwent treatment for central precocious puberty and later presented with primary amenorrhea. The karyotype revealed 47,XX,+mar. FISH analysis for the marker chromosome showed partial trisomy/tetrasomy for proximal chromosome 15q (15p13q13). FISH using an ELN -specific probe demonstrated a deletion in the Williams syndrome critical region in 7q11.23. To our knowledge, a coexistence of Williams syndrome and 15q duplication syndrome has not been reported in the literature. Our patient had early pubertal development, which has been described in some patients with Williams syndrome. However, years later after discontinuing gonadotropin-releasing hormone analogue treatment, she developed primary amenorrhea.
Domain-wall superconductivity in superconductor-ferromagnet hybrids.
Yang, Zhaorong; Lange, Martin; Volodin, Alexander; Szymczak, Ritta; Moshchalkov, Victor V
2004-11-01
Superconductivity and magnetism are two antagonistic cooperative phenomena, and the intriguing problem of their coexistence has been studied for several decades. Recently, artificial hybrid superconductor-ferromagnet systems have been commonly used as model systems to reveal the interplay between competing superconducting and magnetic order parameters, and to verify the existence of new physical phenomena, including the predicted domain-wall superconductivity (DWS). Here we report the experimental observation of DWS in superconductor-ferromagnet hybrids using a niobium film on a BaFe(12)O(19) single crystal. We found that the critical temperature T(c) of the superconductivity nucleation in niobium increases with increasing field until it reaches the saturation field of BaFe(12)O(19). In accordance with the field-shift of the maximum value of T(c), pronounced hysteresis effects have been found in resistive transitions. We argue that the compensation of the applied field by the stray fields of the magnetic domains as well as the change in the domain structure is responsible for the appearance of the DWS and the coexistence of superconductivity and magnetism in the superconductor-ferromagnet hybrids.
Chimera at the phase-flip transition of an ensemble of identical nonlinear oscillators
NASA Astrophysics Data System (ADS)
Gopal, R.; Chandrasekar, V. K.; Senthilkumar, D. V.; Venkatesan, A.; Lakshmanan, M.
2018-06-01
A complex collective emerging behavior characterized by coexisting coherent and incoherent domains is termed as a chimera state. We bring out the existence of a new type of chimera in a nonlocally coupled ensemble of identical oscillators driven by a common dynamic environment. The latter facilitates the onset of phase-flip bifurcation/transitions among the coupled oscillators of the ensemble, while the nonlocal coupling induces a partial asynchronization among the out-of-phase synchronized oscillators at this onset. This leads to the manifestation of coexisting out-of-phase synchronized coherent domains interspersed by asynchronous incoherent domains elucidating the existence of a different type of chimera state. In addition to this, a rich variety of other collective behaviors such as clusters with phase-flip transition, conventional chimera, solitary state and complete synchronized state which have been reported using different coupling architectures are found to be induced by the employed couplings for appropriate coupling strengths. The robustness of the resulting dynamics is demonstrated in ensembles of two paradigmatic models, namely Rössler oscillators and Stuart-Landau oscillators.
Uduma, Uduma Felix; Pius, Fokam; Mathieu, Motah
2012-01-01
Objective: Intracranial calcifications underlie certain brain diseases which may be de novo or systemic. But calclfications un-connected to pathologies are classified physiological. Aim: To evaluate physiological intracranial calcifications in Douala with establishment of earliest age range of detection. Materials and Methods: Prospective study of brain computed tomograms was done from April to October 2009 using Schumadzu CT Scan machine. Axial, reconstructed and bone window images as well Hounsfield unit measurements were used for final evaluations. Results were analysed with SSPS 3. Results: 132 patients with 75 males and 57 females were studied and 163 separate calcifications were identified due to co-existent calcifications. The highest calcification was in choroid plexi, constituiting 56.82% of the studied population. This was followed by pineal gland. Both were commonly co-existent with advancing age. These calcifications were first seen at 10-19years. No type of physiological intracranial calcification was seen below age 10. The least calcification of 0.76% of population was in dentate nucleus. Conclusion: No intra-cranial physiological calcifications started earlier than 9years in Douala, a city in Cameroon, Central Africa. PMID:22980109
Uduma, Felix Uduma; Pius, Fokam; Mathieu, Motah
2011-12-29
Intracranial calcifications underlie certain brain diseases which may be de novo or systemic. But calcifications un-connected to pathologies are classified physiological. To evaluate physiological intracranial calcifications in Douala with establishment of earliest age range of detection. Prospective study of brain computed tomograms was done from April to October 2009 using Schumadzu CT Scan machine. Axial, reconstructed and bone window images as well Hounsfield unit measurements were used for final evaluations. RESULTS were analysed with SSPS 3. 132 patients with 75 males and 57 females were studied and 163 separate calcifications were identified due to co-existent calcifications. The highest calcification was in choroid plexi, constituting 56.82% of the studied population. This was followed by pineal gland. Both were commonly co-existent with advancing age. These calcifications were first seen at 10-19 years. No type of physiological intracranial calcification was seen below age 10. The least calcification of 0.76% of population was in dentate nucleus. No intra-cranial physiological calcifications started earlier than 9 years in Douala, a city in Cameroon, Central Africa.
Coexistence of Nerve Enlargement and Neuratrophy Detected by Ultrasonography in Leprosy Patients.
Chen, Xiaohua; Zhang, Liangfu; Huang, Meiying; Zhai, Xiuli; Wen, Yan; Pan, Chunzhi
2018-05-17
The purpose of this study was to evaluate peripheral neural impairment in leprosy patients by ultrasonography (US). The cross-sectional areas (CSAs) of the median (M), ulnar (U) and common fibular (CF) nerves were compared in 71 leprosy patients and 29 healthy controls, and the data were analyzed between the leprosy, multibacillary (MB)/paucibacillary (PB), reaction (R)/no reaction (NR), disability (D)/no disability (ND), and longer/shorter duration groups after treatment. We found that for the nerves located in upper limbs, the CSAs were significantly increased in the leprosy patients vs the controls; the PB group vs the MB group; the R group vs the NR group; the ND group vs the D group; and the longer duration group vs the shorter duration group at some positions of the M nerve and U nerve. In contrast, for the nerves located in lower limbs, the CSAs were significantly reduced in the leprosy patients vs the controls and in the longer duration group vs the shorter duration group at some positions of the CF nerve. This result indicated that nerve enlargement and neuratrophy coexist in leprosy patients.