How jurors use and misuse character evidence.

PubMed

Hunt, Jennifer S; Budesheim, Thomas Lee

2004-04-01

The Federal Rules of Evidence allow defendants to offer testimony about their good character, but that testimony can be impeached with cross-examination or a rebuttal witness. It is assumed that jurors use the defense's character evidence (CE) to form guilt and conviction judgments but use impeachment evidence only to assess the character witness's credibility. Two experiments tested these assumptions by presenting mock jurors with various forms of CE and impeachment. Participants made trait ratings for the character witness and defendant and guilt and conviction judgments. Positive CE did not affect guilt or conviction judgments, but cross-examination caused a backlash in which judgments were harsher than when no CE was given. Using path analysis, the authors tested a model of the process by which CE and impeachment affect defendant and witness impressions and guilt and conviction judgments. Implications for juror decision making are discussed.

Multitriggered Tumor-Responsive Drug Delivery Vehicles Based on Protein and Polypeptide Coassembly for Enhanced Photodynamic Tumor Ablation.

PubMed

Zhang, Ning; Zhao, Fenfang; Zou, Qianli; Li, Yongxin; Ma, Guanghui; Yan, Xuehai

2016-11-01

Tumor-responsive nanocarriers are highly valuable and demanded for smart drug delivery particularly in the field of photodynamic therapy (PDT), where a quick release of photosensitizers in tumors is preferred. Herein, it is demonstrated that protein-based nanospheres, prepared by the electrostatic assembly of proteins and polypeptides with intermolecular disulfide cross-linking and surface polyethylene glycol coupling, can be used as versatile tumor-responsive drug delivery vehicles for effective PDT. These nanospheres are capable of encapsulation of various photosensitizers including Chlorin e6 (Ce6), protoporphyrin IX, and verteporfin. The Chlorin e6-encapsulated nanospheres (Ce6-Ns) are responsive to changes in pH, redox potential, and proteinase concentration, resulting in multitriggered rapid release of Ce6 in an environment mimicking tumor tissues. In vivo fluorescence imaging results indicate that Ce6-Ns selectively accumulate near tumors and the quick release of Ce6 from Ce6-Ns can be triggered by tumors. In tumors the fluorescence of released Ce6 from Ce6-Ns is observed at 0.5 h postinjection, while in normal tissues the fluorescence appeared at 12 h postinjection. Tumor ablation is demonstrated by in vivo PDT using Ce6-Ns and the biocompatibility of Ce6-Ns is evident from the histopathology imaging, confirming the enhanced in vivo PDT efficacy and the biocompatibility of the assembled drug delivery vehicles. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The electrical and interfacial properties of metal-high-k oxide-semiconductor field effect transistors with CeO2/HfO2 laminated gate dielectrics

NASA Astrophysics Data System (ADS)

Chang, Ingram Yin-ku; Chen, Chun-Heng; Chiu, Fu-Chien; Lee, Joseph Ya-min

2007-11-01

Metal-oxide-semiconductor field-effect transistors with CeO2/HfO2 laminated gate dielectrics were fabricated. The transistors have a subthreshold slope of 74.9mV/decade. The interfacial properties were measured using gated diodes. The surface state density Dit was 9.78×1011cm-2eV-1. The surface-recombination velocity (s0) and the minority carrier lifetime in the field-induced depletion region (τ0,FIJ) measured from the gated diode were about 6.11×103cm /s and 1.8×10-8s, respectively. The effective capture cross section of surface state (σs) extracted using the subthreshold-swing measurement and the gated diode was about 7.69×10-15cm2. The effective electron mobility of CeO2/HfO2 laminated gated transistors was determined to be 212cm2/Vs.

Serological reactivity of patients with Echinococcus infections (E. granulosus, E. vogeli, and E. multilocularis) against three antigen B subunits.

PubMed

de la Rue, Mário L; Yamano, Kimiaki; Almeida, Cybele E; Iesbich, Margarete P; Fernandes, Cloé D; Goto, Akiko; Kouguchi, Hirokazu; Takahashi, Kenichi

2010-02-01

In serodiagnosis of cystic echinococcosis (CE) by Echinococcus granulosus infection, antigen B (AgB) has been utilized worldwide. However, it is known that about 40% of sera with alveolar echinococcosis (AE) by Echinococcus multilocularis infection recognize AgB. Furthermore, cross-reaction against AgB was also reported in sera from polycystic echinococcosis (PE) patients with Echinococcus vogeli infection. These findings indicate that AgB is widely common to the genus Echinococcus. On the other hand, AgB has several subunits, which are composed of the smallest 8-kDa subunit. In this study, reactivities of patient sera with three kinds of Echinococcus infections (CE, PE, and AE) were compared simultaneously under the same condition against three subunits of AgB (8, 16, and 24 kDa). Many articles have referred the fundamental 8- kDa subunit as a diagnostic antigen for CE. However, the reactivity for the 8-kDa subunit of the CE patient was not so high (47.7%) in this study. Furthermore, there are many cases in which serum of patients with PE or AE also recognizes this subunit (66.7% in PE; 45.9% in AE). AgB is effective for the detection of the genus Echinococcus infections, but it does not have high species specificity. Therefore, we need to pay attention to cross-reaction in serodiagnosis of CE in areas where plural species coexist.

Effect of Standardized Boesenbergia pandurata Extract and Its Active Compound Panduratin A on Skin Hydration and Barrier Function in Human Epidermal Keratinocytes.

PubMed

Woo, Seon Wook; Rhim, Dong-Bin; Kim, Changhee; Hwang, Jae-Kwan

2015-03-01

The skin plays a key role in protecting the body from the environment and from water loss. Cornified envelope (CE) and natural moisturizing factor (NMF) are considered as the primary regulators of skin hydration and barrier function. The CE prevents loss of water from the body and is formed by cross-linking of several proteins. Among these proteins, filaggrin is an important protein because NMF is produced by the degradation of filaggrin. Proteases, including matriptase and prostasin, stimulate the generation of filaggrin from profilaggrin and caspase-14 plays a role in the degradation of filaggrin. This study elucidated the effects of an ethanol extract of Boesenbergia pandurata (Roxb.) Schltr., known as fingerroot, and its active compound panduratin A on CE formation and filaggrin processing in HaCaT, human epidermal keratinocytes. B. pandurata extract (BPE) and panduratin A significantly stimulated not only CE formation but also the expression of CE proteins, such as loricrin, involucrin, and transglutaminase, which were associated with PPARα expression. The mRNA and protein levels of filaggrin and filaggrin-related enzymes, such as matriptase, prostasin, and caspase-14 were also up-regulated by BPE and panduratin A treatment. These results suggest that BPE and panduratin A are potential nutraceuticals which can enhance skin hydration and barrier function based on their CE formation and filaggrin processing.

Ferromagnetic quantum critical point in CePd2P2 with Pd → Ni substitution

NASA Astrophysics Data System (ADS)

Lai, Y.; Bone, S. E.; Minasian, S.; Ferrier, M. G.; Lezama-Pacheco, J.; Mocko, V.; Ditter, A. S.; Kozimor, S. A.; Seidler, G. T.; Nelson, W. L.; Chiu, Y.-C.; Huang, K.; Potter, W.; Graf, D.; Albrecht-Schmitt, T. E.; Baumbach, R. E.

2018-06-01

An investigation of the structural, thermodynamic, and electronic transport properties of the isoelectronic chemical substitution series Ce (Pd1-xNix) 2P2 is reported, where a possible ferromagnetic quantum critical point is uncovered in the temperature-concentration (T -x ) phase diagram. This behavior results from the simultaneous contraction of the unit cell volume, which tunes the relative strengths of the Kondo and Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions, and the introduction of disorder through alloying. Near the critical region at xcr≈ 0.7, the rate of contraction of the unit cell volume strengthens, indicating that the cerium f valence crosses over from trivalent to a noninteger value. Consistent with this picture, x-ray absorption spectroscopy measurements reveal that while CePd2P2 has a purely trivalent cerium f state, CeNi2P2 has a small (<10 %) tetravalent contribution. In a broad region around xcr, there is a breakdown of Fermi-liquid temperature dependences, signaling the influence of quantum critical fluctuations and disorder effects. Measurements of clean CePd2P2 furthermore show that applied pressure has an initial effect similar to alloying on the ferromagnetic order. From these results, CePd2P2 emerges as a keystone system to test theories such as the Belitz-Kirkpatrick-Vojta model for ferromagnetic quantum criticality, where distinct behaviors are expected in the dirty and clean limits.

Doping of Czochralski-grown bulk β-Ga2O3 single crystals with Cr, Ce and Al

NASA Astrophysics Data System (ADS)

Galazka, Zbigniew; Ganschow, Steffen; Fiedler, Andreas; Bertram, Rainer; Klimm, Detlef; Irmscher, Klaus; Schewski, Robert; Pietsch, Mike; Albrecht, Martin; Bickermann, Matthias

2018-03-01

We experimentally evaluated segregation of Cr, Ce and Al in bulk β-Ga2O3 single crystals grown by the Czochralski method, as well as the impact of these dopants on optical properties. The segregation of Cr and Ce and their incorporation into the β-Ga2O3 crystal structure strongly depends on O2 concentration in the growth atmosphere which has a noticeable impact on decomposition of Ga2O3 and Cr2O3, as well as on the charge state of Cr and Ce. Effective segregation coefficients for Cr are in the range of 3.1-1.5 at 7-24 vol% O2, while for Ce they are roughly below 0.01 at 1.5-34 vol% O2. The effective segregation coefficient for Al is 1.1 at 1.5-21 vol% O2. Both dopants Ce and Al have a thermodynamically stabilizing effect on β-Ga2O3 crystal growth by supressing decomposition. While Ce has no impact on the optical transmittance in the ultraviolet and visible regions, in Cr doped crystals we observe three absorption bands due to Cr3+ on octahedral Ga sites, one in the ultraviolet merging with the band edge absorption of β-Ga2O3 and two in the visible spectrum, for which we estimate the absorption cross sections. Al doping also does not induce dopant related absorption bands but clearly shifts the absorption edge as one expects for a solid-solution crystal Ga2(1-x)Al2xO3 still in the monoclinic phase. For the highest doping concentration (Ga1.9Al0.1O3) we estimate an increase of the energy gap by 0.11 eV.

Static (1)H dynamic nuclear polarization with the biradical TOTAPOL: a transition between the solid effect and the cross effect.

PubMed

Shimon, Daphna; Feintuch, Akiva; Goldfarb, Daniella; Vega, Shimon

2014-04-14

To study the solid state (1)H-DNP mechanism of the biradical TOTAPOL under static conditions the frequency swept DNP enhancement spectra of samples containing 20 mM and 5 mM TOTAPOL were measured as a function of MW irradiation time and temperature. We observed that under static DNP conditions the biradical TOTAPOL behaves similar to the monoradical TEMPOL, in contrast to MAS DNP where TOTAPOL is considerably more effective. As previously done for TEMPOL, the TOTAPOL DNP spectra were analyzed taking a superposition of a basic SE-DNP lineshape and a basic CE-DNP lineshape with different amplitudes. The analysis of the steady state DNP spectra showed that the SE was dominant in the 6-10 K range and the CE was dominant above 10 K. DNP spectra obtained as a function of MW irradiation time allowed resolving the individual SE and CE buildup times. At low temperatures the SE buildup time was faster than the CE buildup time and at all temperatures the CE buildup time was close to the nuclear spin-lattice relaxation time, T1n. Polarization calculations involving nuclear spin-diffusion for a model system of one electron and many nuclei suggested that the shortening of the T1n for increasing temperatures is the reason why the SE contribution to the overall enhancement was reduced.

Preferences for and Barriers to Formal and Informal Athletic Training Continuing Education Activities

PubMed Central

Armstrong, Kirk J.; Weidner, Thomas G.

2011-01-01

Context: Our previous research determined the frequency of participation and perceived effect of formal and informal continuing education (CE) activities. However, actual preferences for and barriers to CE must be characterized. Objective: To determine the types of formal and informal CE activities preferred by athletic trainers (ATs) and barriers to their participation in these activities. Design: Cross-sectional study. Setting: Athletic training practice settings. Patients or Other Participants: Of a geographically stratified random sample of 1000 ATs, 427 ATs (42.7%) completed the survey. Main Outcome Measure(s): As part of a larger study, the Survey of Formal and Informal Athletic Training Continuing Education Activities (FIATCEA) was developed and administered electronically. The FIATCEA consists of demographic characteristics and Likert scale items (1 = strongly disagree, 5 = strongly agree) about preferred CE activities and barriers to these activities. Internal consistency of survey items, as determined by Cronbach α, was 0.638 for preferred CE activities and 0.860 for barriers to these activities. Descriptive statistics were computed for all items. Differences between respondent demographic characteristics and preferred CE activities and barriers to these activities were determined via analysis of variance and dependent t tests. The α level was set at .05. Results: Hands-on clinical workshops and professional networking were the preferred formal and informal CE activities, respectively. The most frequently reported barriers to formal CE were the cost of attending and travel distance, whereas the most frequently reported barriers to informal CE were personal and job-specific factors. Differences were noted between both the cost of CE and travel distance to CE and all other barriers to CE participation (F1,411 = 233.54, P < .001). Conclusions: Overall, ATs preferred formal CE activities. The same barriers (eg, cost, travel distance) to formal CE appeared to be universal to all ATs. Informal CE was highly valued by ATs because it could be individualized. PMID:22488195

Contrast-enhanced magnetic resonance angiography for the detection of crossing renal vessels in children with symptomatic ureteropelvic junction obstruction: comparison with operative findings.

PubMed

Calder, Alistair D; Hiorns, Melanie P; Abhyankar, Aruna; Mushtaq, Imran; Olsen, Oystein E

2007-04-01

Crossing renal vessels (CRV) are associated with ureteropelvic junction (UPJ) obstruction, particularly when presentation is beyond the neonatal period. Their presence may influence surgical management. To evaluate the accuracy of contrast-enhanced magnetic resonance angiography (CE-MRA) in the identification of CRV in children requiring surgical treatment of symptomatic UPJ obstruction, against a gold standard of laparoscopic or open surgical findings. We reviewed CE-MRA studies (3-D T2-weighted turbo spin-echo and multiphase 3-D spoiled gradient echo following intravenous gadolinium administration) of 14 children, age range 6-15 years, performed prior to surgery for suspected CRV-related UPJ obstruction. Consensus reviews of the CE-MRA studies were compared with surgical findings. CE-MRA demonstrated CRV at the level of the obstruction in nine and no crossing vessels in five children. These were all verified intraoperatively (chi2=14.0; P<0.001). In eight of the nine patients with CRV there was no evidence of intrinsic obstruction at surgery. In the remaining patient there was fibrosis of the upper ureter. CE-MRA is an accurate means of identifying CRV in children older than 6 years with symptomatic UPJ obstruction.

CE-BLAST makes it possible to compute antigenic similarity for newly emerging pathogens.

PubMed

Qiu, Tianyi; Yang, Yiyan; Qiu, Jingxuan; Huang, Yang; Xu, Tianlei; Xiao, Han; Wu, Dingfeng; Zhang, Qingchen; Zhou, Chen; Zhang, Xiaoyan; Tang, Kailin; Xu, Jianqing; Cao, Zhiwei

2018-05-02

Major challenges in vaccine development include rapidly selecting or designing immunogens for raising cross-protective immunity against different intra- or inter-subtypic pathogens, especially for the newly emerging varieties. Here we propose a computational method, Conformational Epitope (CE)-BLAST, for calculating the antigenic similarity among different pathogens with stable and high performance, which is independent of the prior binding-assay information, unlike the currently available models that heavily rely on the historical experimental data. Tool validation incorporates influenza-related experimental data sufficient for stability and reliability determination. Application to dengue-related data demonstrates high harmonization between the computed clusters and the experimental serological data, undetectable by classical grouping. CE-BLAST identifies the potential cross-reactive epitope between the recent zika pathogen and the dengue virus, precisely corroborated by experimental data. The high performance of the pathogens without the experimental binding data suggests the potential utility of CE-BLAST to rapidly design cross-protective vaccines or promptly determine the efficacy of the currently marketed vaccine against emerging pathogens, which are the critical factors for containing emerging disease outbreaks.

Anti-CeHV1 antibodies of two cynomolgus macaques cross-react with HSV2 but not HSV1 antigens in ELISA.

PubMed

Coutrot, Edwin; Blancher-Sardou, Marie; Blancher, Antoine

2008-02-01

The aim of the study was to compare the cross-reactivity of macaque anti-CeHV1 antibodies with type 1 and type 2 human herpes simplex viruses (HSV1 and HSV2). We studied the serum of 344 animals which had been tested either positive (n = 39) or negative (n = 305) for the presence of CeHV1 antibodies by expert laboratories. Macaque serums were studied by means of two ELISA: one based on HSV1 antigen-coated wells, the other on polystyrene beads coated with HSV1 and HSV2 antigens in approximately equal proportions. In the serum of two animals originating from Vietnam, we found anti-CeHV1 antibodies cross-reacting with HSV2 but not with HSV1 antigens. For the serum with the highest titer, inhibition by soluble antigens confirmed the high affinity of the antibodies for HSV2 antigens. Tests using HSV1 and HSV2 in a combined way are better suited to macaque screening than tests using only HSV1 antigens.

An experimental study of interstitial lung tissue classification in HRCT images using ANN and role of cost functions

NASA Astrophysics Data System (ADS)

Dash, Jatindra K.; Kale, Mandar; Mukhopadhyay, Sudipta; Khandelwal, Niranjan; Prabhakar, Nidhi; Garg, Mandeep; Kalra, Naveen

2017-03-01

In this paper, we investigate the effect of the error criteria used during a training phase of the artificial neural network (ANN) on the accuracy of the classifier for classification of lung tissues affected with Interstitial Lung Diseases (ILD). Mean square error (MSE) and the cross-entropy (CE) criteria are chosen being most popular choice in state-of-the-art implementations. The classification experiment performed on the six interstitial lung disease (ILD) patterns viz. Consolidation, Emphysema, Ground Glass Opacity, Micronodules, Fibrosis and Healthy from MedGIFT database. The texture features from an arbitrary region of interest (AROI) are extracted using Gabor filter. Two different neural networks are trained with the scaled conjugate gradient back propagation algorithm with MSE and CE error criteria function respectively for weight updation. Performance is evaluated in terms of average accuracy of these classifiers using 4 fold cross-validation. Each network is trained for five times for each fold with randomly initialized weight vectors and accuracies are computed. Significant improvement in classification accuracy is observed when ANN is trained by using CE (67.27%) as error function compared to MSE (63.60%). Moreover, standard deviation of the classification accuracy for the network trained with CE (6.69) error criteria is found less as compared to network trained with MSE (10.32) criteria.

Multicolor tuning towards single red-emission band of upconversion nanoparticles for tunable optical component and optical/x-ray imaging agents via Ce(3+) doping.

PubMed

Yi, Zhigao; Zeng, Tianmei; Xu, Yaru; Lu, Wei; Qian, Chao; Liu, Hongrong; Zeng, Songjun; Hao, Jianhua

2015-09-25

A simple strategy of Ce(3+) doping is proposed to realize multicolor tuning and predominant red emission in BaLnF5:Yb(3+)/Ho(3+) (Ln(3+) = Gd(3+), Y(3+), Yb(3+)) systems. A tunable upconversion (UC) multicolor output from green/yellow to red can be readily achieved in a fixed Yb(3+)/Ho(3+) composition by doping Ce(3+), providing an effective route for multicolor tuning widely used for various optical components. Moreover, compared with Ce(3+)-free UC nanoparticles (UCNPs), a remarkable enhancement of the red-to-green (R/G) ratio is observed by doping 30% Ce(3+), arising from the two largely promoted cross-relaxation (CR) processes between Ce(3+) and Ho(3+). UCNPs with pure red emission are selected as in vivo UC bioimaging agents, demonstrating the merits of deep penetration depth, the absence of autofluorescence and high contrast in small animal bioimaging. Moreover, such fluorescence imaging nanoprobes can also be used as contrast agents for three-dimensional (3D) x-ray bioimaging by taking advantage of the high K-edge values and x-ray absorption coefficients of Ba(2+), Gd(3+), and Ce(3+) in our designed nanoprobes. Thus, the simultaneous realization of multicolor output, highly enhanced R/G ratio, and predominant red emission makes the Ce(3+)-doped UCNPs very useful for widespread applications in optical components and bioimaging.

Developing cross entropy genetic algorithm for solving Two-Dimensional Loading Heterogeneous Fleet Vehicle Routing Problem (2L-HFVRP)

NASA Astrophysics Data System (ADS)

Paramestha, D. L.; Santosa, B.

2018-04-01

Two-dimensional Loading Heterogeneous Fleet Vehicle Routing Problem (2L-HFVRP) is a combination of Heterogeneous Fleet VRP and a packing problem well-known as Two-Dimensional Bin Packing Problem (BPP). 2L-HFVRP is a Heterogeneous Fleet VRP in which these costumer demands are formed by a set of two-dimensional rectangular weighted item. These demands must be served by a heterogeneous fleet of vehicles with a fix and variable cost from the depot. The objective function 2L-HFVRP is to minimize the total transportation cost. All formed routes must be consistent with the capacity and loading process of the vehicle. Sequential and unrestricted scenarios are considered in this paper. We propose a metaheuristic which is a combination of the Genetic Algorithm (GA) and the Cross Entropy (CE) named Cross Entropy Genetic Algorithm (CEGA) to solve the 2L-HFVRP. The mutation concept on GA is used to speed up the algorithm CE to find the optimal solution. The mutation mechanism was based on local improvement (2-opt, 1-1 Exchange, and 1-0 Exchange). The probability transition matrix mechanism on CE is used to avoid getting stuck in the local optimum. The effectiveness of CEGA was tested on benchmark instance based 2L-HFVRP. The result of experiments shows a competitive result compared with the other algorithm.

Cumulative exposure to work-related traumatic events and current post-traumatic stress disorder in New York City's first responders.

PubMed

Geronazzo-Alman, Lupo; Eisenberg, Ruth; Shen, Sa; Duarte, Cristiane S; Musa, George J; Wicks, Judith; Fan, Bin; Doan, Thao; Guffanti, Guia; Bresnahan, Michaeline; Hoven, Christina W

2017-04-01

Cumulative exposure to work-related traumatic events (CE) is a foreseeable risk for psychiatric disorders in first responders (FRs). Our objective was to examine the impact of work-related CE that could serve as predictor of posttraumatic stress disorder (PTSD) and/or depression in FRs. Cross-sectional examination of previous CE and past-month PTSD outcomes and depression in 209 FRs. Logistic (probable PTSD; probable depression) and Poisson regressions (PTSD score) of the outcomes on work-related CE indexes, adjusting for demographic variables. Differences across occupational groups were also examined. Receiver operating characteristic analysis determined the sensitivity and specificity of CE indexes. All indexes were significantly and differently associated with PTSD; associations with depression were non-significant. The index capturing the sheer number of different incidents experienced regardless of frequency ('Variety') showed conceptual, practical and statistical advantages compared to other indexes. In general, the indexes showed poor to fair discrimination accuracy. Work-related CE is specifically associated with PTSD. Focusing on the variety of exposures may be a simple and effective strategy to predict PTSD in FRs. Further research on sensitivity and specificity of exposure indexes, preferably examined prospectively, is needed and could lead to early identification of individuals at risk. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of CeO2 and Y2O3 on microstructure, bioactivity and degradability of laser cladding CaO-SiO2 coating on titanium alloy.

PubMed

Li, H C; Wang, D G; Chen, C Z; Weng, F

2015-03-01

To solve the lack of strength of bulk biomaterials for load-bearing applications and improve the bioactivity of titanium alloy (Ti-6Al-4V), CaO-SiO2 coatings on titanium alloy were fabricated by laser cladding technique. The effect of CeO2 and Y2O3 on microstructure and properties of laser cladding coating was analyzed. The cross-section microstructure of ceramic layer from top to bottom gradually changes from cellular-dendrite structure to compact cellular crystal. The addition of CeO2 or Y2O3 refines the microstructure of the ceramic layer in the upper and middle regions. The refining effect on the grain is related to the kinds of additives and their content. The coating is mainly composed of CaTiO3, CaO, α-Ca2(SiO4), SiO2 and TiO2. Y2O3 inhibits the formation of CaO. After soaking in simulated body fluid (SBF), the calcium phosphate layer is formed on the coating surface, indicating the coating has bioactivity. After soaking in Tris-HCl solution, the samples doped with CeO2 or Y2O3 present a lower weight loss, indicating the addition of CeO2 or Y2O3 improves the degradability of laser cladding sample. Copyright © 2015 Elsevier B.V. All rights reserved.

Imaging properties of pixellated scintillators with deep pixels

PubMed Central

Barber, H. Bradford; Fastje, David; Lemieux, Daniel; Grim, Gary P.; Furenlid, Lars R.; Miller, Brian W.; Parkhurst, Philip; Nagarkar, Vivek V.

2015-01-01

We have investigated the light-transport properties of scintillator arrays with long, thin pixels (deep pixels) for use in high-energy gamma-ray imaging. We compared 10×10 pixel arrays of YSO:Ce, LYSO:Ce and BGO (1mm × 1mm × 20 mm pixels) made by Proteus, Inc. with similar 10×10 arrays of LSO:Ce and BGO (1mm × 1mm × 15mm pixels) loaned to us by Saint-Gobain. The imaging and spectroscopic behaviors of these scintillator arrays are strongly affected by the choice of a reflector used as an inter-pixel spacer (3M ESR in the case of the Proteus arrays and white, diffuse-reflector for the Saint-Gobain arrays). We have constructed a 3700-pixel LYSO:Ce Prototype NIF Gamma-Ray Imager for use in diagnosing target compression in inertial confinement fusion. This system was tested at the OMEGA Laser and exhibited significant optical, inter-pixel cross-talk that was traced to the use of a single-layer of ESR film as an inter-pixel spacer. We show how the optical cross-talk can be mapped, and discuss correction procedures. We demonstrate a 10×10 YSO:Ce array as part of an iQID (formerly BazookaSPECT) imager and discuss issues related to the internal activity of 176Lu in LSO:Ce and LYSO:Ce detectors. PMID:26236070

Imaging properties of pixellated scintillators with deep pixels

NASA Astrophysics Data System (ADS)

Barber, H. Bradford; Fastje, David; Lemieux, Daniel; Grim, Gary P.; Furenlid, Lars R.; Miller, Brian W.; Parkhurst, Philip; Nagarkar, Vivek V.

2014-09-01

We have investigated the light-transport properties of scintillator arrays with long, thin pixels (deep pixels) for use in high-energy gamma-ray imaging. We compared 10x10 pixel arrays of YSO:Ce, LYSO:Ce and BGO (1mm x 1mm x 20 mm pixels) made by Proteus, Inc. with similar 10x10 arrays of LSO:Ce and BGO (1mm x 1mm x 15mm pixels) loaned to us by Saint-Gobain. The imaging and spectroscopic behaviors of these scintillator arrays are strongly affected by the choice of a reflector used as an inter-pixel spacer (3M ESR in the case of the Proteus arrays and white, diffuse-reflector for the Saint-Gobain arrays). We have constructed a 3700-pixel LYSO:Ce Prototype NIF Gamma-Ray Imager for use in diagnosing target compression in inertial confinement fusion. This system was tested at the OMEGA Laser and exhibited significant optical, inter-pixel cross-talk that was traced to the use of a single-layer of ESR film as an inter-pixel spacer. We show how the optical cross-talk can be mapped, and discuss correction procedures. We demonstrate a 10x10 YSO:Ce array as part of an iQID (formerly BazookaSPECT) imager and discuss issues related to the internal activity of 176Lu in LSO:Ce and LYSO:Ce detectors.

Collective Efficacy in Sports and Physical Activities: Perceived Emotional Synchrony and Shared Flow.

PubMed

Zumeta, Larraitz N; Oriol, Xavier; Telletxea, Saioa; Amutio, Alberto; Basabe, Nekane

2015-01-01

This cross-sectional study analyzes the relationship between collective efficacy and two psychosocial processes involved in collective sport-physical activities. It argues that in-group identification and fusion with the group will affect collective efficacy (CE). A sample of 276 university students answered different scales regarding their participation in collective physical and sport activities. Multiple-mediation analyses showed that shared flow and perceived emotional synchrony mediate the relationship between in-group identification and CE, whereas the relationship between identity fusion and CE was only mediated by perceived emotional synchrony. Results suggest that both psychosocial processes explain the positive effects of in-group identification and identity fusion with the group in collective efficacy. Specifically, the role of perceived emotional synchrony in explaining the positive effects of participation in collective sport-physical activities is underlined. In sum, this study highlights the utility of collective actions and social identities to explain the psychosocial processes related to collective efficacy in physical and sports activities. Finally, practical implications are discussed.

Collective Efficacy in Sports and Physical Activities: Perceived Emotional Synchrony and Shared Flow

PubMed Central

Zumeta, Larraitz N.; Oriol, Xavier; Telletxea, Saioa; Amutio, Alberto; Basabe, Nekane

2016-01-01

This cross-sectional study analyzes the relationship between collective efficacy and two psychosocial processes involved in collective sport-physical activities. It argues that in-group identification and fusion with the group will affect collective efficacy (CE). A sample of 276 university students answered different scales regarding their participation in collective physical and sport activities. Multiple-mediation analyses showed that shared flow and perceived emotional synchrony mediate the relationship between in-group identification and CE, whereas the relationship between identity fusion and CE was only mediated by perceived emotional synchrony. Results suggest that both psychosocial processes explain the positive effects of in-group identification and identity fusion with the group in collective efficacy. Specifically, the role of perceived emotional synchrony in explaining the positive effects of participation in collective sport-physical activities is underlined. In sum, this study highlights the utility of collective actions and social identities to explain the psychosocial processes related to collective efficacy in physical and sports activities. Finally, practical implications are discussed. PMID:26779077

On the use temperature parameterized rate coefficients in the estimation of non-equilibrium reaction rates

NASA Astrophysics Data System (ADS)

Shizgal, Bernie D.; Chikhaoui, Aziz

2006-06-01

The present paper considers a detailed analysis of the nonequilibrium effects for a model reactive system with the Chapman-Eskog (CE) solution of the Boltzmann equation as well as an explicit time dependent solution. The elastic cross sections employed are a hard sphere cross section and the Maxwell molecule cross section. Reactive cross sections which model reactions with and without activation energy are used. A detailed comparison is carried out with these solutions of the Boltzmann equation and the approximation introduced by Cukrowski and coworkers [J. Chem. Phys. 97 (1992) 9086; Chem. Phys. 89 (1992) 159; Physica A 188 (1992) 344; Chem. Phys. Lett. A 297 (1998) 402; Physica A 275 (2000) 134; Chem. Phys. Lett. 341 (2001) 585; Acta Phys. Polonica B 334 (2003) 3607.] based on the temperature of the reactive particles. We show that the Cukrowski approximation has limited applicability for the large class of reactive systems studied in this paper. The explicit time dependent solutions of the Boltzmann equation demonstrate that the CE approach is valid only for very slow reactions for which the corrections to the equilibrium rate coefficient are very small.

Co-encapsulation of CdSe/ZnS and CeO2 nanoparticles in waterborne polymer dispersions: enhancement of fluorescence emission under sunlight.

PubMed

De San Luis, Alicia; Paulis, Maria; Leiza, Jose Ramon

2017-11-15

Hybrid core/shell polymer particles with co-encapsulated quantum dots (QDs) (CdSe/ZnS) and CeO 2 nanoparticles have been synthesized in a two stage semi-batch emulsion polymerization process. In the first stage, both inorganic nanoparticles are incorporated into cross-linked polystyrene (PS) particles by miniemulsion polymerization. This hybrid dispersion is then used as the seed to produce the core/shell particles by starved feeding of methyl methacrylate and divinylbenzene (MMA/DVB) monomers. The core/shell hybrid dispersions maintained in the dark exhibit stable fluorescence emission over time, and notably their fluorescence intensity increases under sunlight, likely due to the effect of the co-encapsulated CeO 2 nanoparticles that change the optical properties of the environment of the quantum dot particles. The fluorescence increase depends on the QD : CeO 2 ratio, with the 1 : 2 ratio resulting in the highest increase (280%). Furthermore, a film forming hybrid latex has been synthesized using the former core/shell PS/QD/CeO 2 /PMMA particles as seeds and feeding under semi-batch conditions methyl methacrylate, butyl acrylate and acrylic acid. Films cast from this core/shell/shell hybrid dispersion also exhibit fluorescence, and as for the core/shell latex the fluorescence increases under sunlight exposure. Interestingly, the increase in the film is at least two times higher than that in the latex, which is attributed to the additional effect of the neighboring coalesced particles containing CeO 2 affecting the environment of the QDs.

Double-cross hydrostatic pressure sample injection for chip CE: variable sample plug volume and minimum number of electrodes.

PubMed

Luo, Yong; Wu, Dapeng; Zeng, Shaojiang; Gai, Hongwei; Long, Zhicheng; Shen, Zheng; Dai, Zhongpeng; Qin, Jianhua; Lin, Bingcheng

2006-09-01

A novel sample injection method for chip CE was presented. This injection method uses hydrostatic pressure, generated by emptying the sample waste reservoir, for sample loading and electrokinetic force for dispensing. The injection was performed on a double-cross microchip. One cross, created by the sample and separation channels, is used for formation of a sample plug. Another cross, formed by the sample and controlling channels, is used for plug control. By varying the electric field in the controlling channel, the sample plug volume can be linearly adjusted. Hydrostatic pressure takes advantage of its ease of generation on a microfluidic chip, without any electrode or external pressure pump, thus allowing a sample injection with a minimum number of electrodes. The potential of this injection method was demonstrated by a four-separation-channel chip CE system. In this system, parallel sample separation can be achieved with only two electrodes, which is otherwise impossible with conventional injection methods. Hydrostatic pressure maintains the sample composition during the sample loading, allowing the injection to be free of injection bias.

Performance of thin long scintillator strips of GSO:Ce, LGSO:Ce and LuAG:Pr for low energy γ-rays

NASA Astrophysics Data System (ADS)

Kobayashi, Masaaki; Aogaki, Souichiro; Takeutchi, Fujio; Tamagawa, Yoichi; Usuki, Yoshiyuki

2012-11-01

Interest in fibers or strips of single crystalline scintillators is increasing for their possible applications in fine-segmented particle detectors for particle physics experiments as well as γ-ray detectors for medical diagnoses. We compared 2×2×100 mm3 strips of Gd2SiO5(GSO):Ce, Lu1.9Gd0.1SiO5 (LGSO):Ce, and Lu3Al5O12(LuAG):Pr single crystals for 0.511 MeV γ-rays with respect to the effective light attenuation length λa, light yield LY, FWHM energy resolution ΔE/E and rms position resolution σ(z) of the injection position z along the length. The obtained result was (λa, LY, ΔE/E, σ(z))=(128 mm, 380 phe/MeV, 17.7%, 8.7 mm) in GSO:Ce, (509 mm, 1760 phe/MeV, 12.2%, 10.9 mm) in LGSO:Ce, and (171 mm, 690 phe/MeV, 15.0%, 8.9 mm) in LuAG:Pr. The z position was obtained independently from the pulse height ratio as well as the timing difference between both ends of the strip. The latter method gave comparable or even smaller σ(z) than the former only in LGSO:Ce having both large LY and fast rise time. The λa in the 100 mm long GSO:Ce strip was found to be twice as large as that in the 200 mm long one [1] with the same cross-section. To obtain good ΔE/E and σ(z), large light yield, fast rise time, and moderately large attenuation length are important for the scintillators.

Effects of unilatral- and bilateral inhibition of rostral ventral tegmental area and central nucleus of amygdala on morphine-induced place conditioning in male Wistar rat.

PubMed

Mohammadian, Zahra; Sahraei, Hedayat; Meftahi, Gholam Hossein; Ali-Beik, Hengameh

2017-03-01

The rostral ventral tegmental area (VTAR) and central nucleus of amygdala (CeA) are considered the main regions for induction of psychological dependence on abused drugs, such as morphine. The main aim of this study was to investigate the transient inhibition of each right and left side as well as both sides of the VTAR and the CeA by lidocaine (2%) on morphine reward properties using the conditioned place preference (CPP) method. Male Wistar rats (250±20 g) 7 days after recovery from surgery and cannulation were conditioned to morphine (7.5 mg/kg) in CPP apparatus. Five minutes before morphine injection in conditioning phase, lidocaine was administered either uni- or bilaterally into the VTAR (0.25 μL/site) or CeA (0.5 μL/site). The results revealed that lidocaine administration into the left side, but not the right side of the VTAR and the CeA reduced morphine CPP significantly. The reduction was potentiated when lidocaine was injected into both sides of the VTAR and the CeA. The number of compartment crossings was reduced when lidocaine was injected into both sides of the VTAR and the CeA as well as the left side. Rearing was reduced when lidocaine was injected into the right, but not the left side of the VTAR. Sniffing and rearing increased when animals received lidocaine in the right side and reduced in the group that received lidocaine in the left side of the CeA. It was concluded that the right and the left side of VTAR and the CeA play different roles in morphine-induced activity and reward. © 2016 John Wiley & Sons Australia, Ltd.

A biomolecular electrostatics solver using Python, GPUs and boundary elements that can handle solvent-filled cavities and Stern layers

NASA Astrophysics Data System (ADS)

Cooper, Christopher D.; Bardhan, Jaydeep P.; Barba, L. A.

2014-03-01

The continuum theory applied to biomolecular electrostatics leads to an implicit-solvent model governed by the Poisson-Boltzmann equation. Solvers relying on a boundary integral representation typically do not consider features like solvent-filled cavities or ion-exclusion (Stern) layers, due to the added difficulty of treating multiple boundary surfaces. This has hindered meaningful comparisons with volume-based methods, and the effects on accuracy of including these features has remained unknown. This work presents a solver called PyGBe that uses a boundary-element formulation and can handle multiple interacting surfaces. It was used to study the effects of solvent-filled cavities and Stern layers on the accuracy of calculating solvation energy and binding energy of proteins, using the well-known APBS finite-difference code for comparison. The results suggest that if required accuracy for an application allows errors larger than about 2% in solvation energy, then the simpler, single-surface model can be used. When calculating binding energies, the need for a multi-surface model is problem-dependent, becoming more critical when ligand and receptor are of comparable size. Comparing with the APBS solver, the boundary-element solver is faster when the accuracy requirements are higher. The cross-over point for the PyGBe code is on the order of 1-2% error, when running on one GPU card (NVIDIA Tesla C2075), compared with APBS running on six Intel Xeon CPU cores. PyGBe achieves algorithmic acceleration of the boundary element method using a treecode, and hardware acceleration using GPUs via PyCuda from a user-visible code that is all Python. The code is open-source under MIT license.

The CE3R Network: current status and future perspectives

NASA Astrophysics Data System (ADS)

Lenhardt, Wolfgang; Pesaresi, Damiano; Živčić, Mladen; Costa, Giovanni; Kuk, Kresimir; Bondár, István; Duni, Llambro; Spacek, Petr

2016-04-01

In order to improve the monitoring of seismic activities in the border regions and to enhance the collaboration between countries and seismological institutions in Central Europe, the Environment Agency of the Slovenian Republic (ARSO), the Italian National Institute for Oceanography and Experimental Geophysics (OGS), the University of Trieste (UniTS) and the Austrian Central Institute for Meteorology and Geodynamics (ZAMG) established in 2001 the "South Eastern Alps Transfrontier Seismological Network". In May 2014 ARSO, OGS, UniTS and ZAMG agreed to formalize the transfrontier network, to name it "Central and East European Earthquake Research Network", (CE3RN or CE3R Network) in order to locate it geographically since cross-border networks can be established in other areas of the world and to expand their cooperation, including institutions in other countries. The University of Zagreb (UniZG) joined CE3RN in October 2014. The Kövesligethy Radó Seismological Observatory (KRSZO) of the Hungarian Academy of Sciences joined CE3RN in October 2015. The Institute of Geosciences, Energy, Water and Environment (IGEWE) of the Polytechnic University of Tirana joined CE3RN in November 2015. The Institute of Physics of the Earth (IPE) of the Masaryk University in Brno joined CE3RN in November 2015. CE3RN Parties intend to formalize and possibly extend their ongoing cooperation in the field of seismological data acquisition, exchange and use for seismological and earthquake engineering and civil protection purposes. The purpose of this cooperation is to retain and expand the existing cross-border network, specify the rules of conduct in the network management, improvements, extensions and enlargements, enhance seismological research in the region, and support civil protection activities. Since the formal establishment of CE3RN, several common projects have been completed, like the SeismoSAT project for the seismic data center connection over satellite funded by the Interreg IV-A Italy-Austria program, and the Earthquake Early Warning System (EEWS) PRESTo@CE3RN. We will here briefly introduce original and new CE3RN Parties, with a synthesis of the common results achieved so far and an indication of possible future developments.

Design of two-dimensional zero reference codes with cross-entropy method.

PubMed

Chen, Jung-Chieh; Wen, Chao-Kai

2010-06-20

We present a cross-entropy (CE)-based method for the design of optimum two-dimensional (2D) zero reference codes (ZRCs) in order to generate a zero reference signal for a grating measurement system and achieve absolute position, a coordinate origin, or a machine home position. In the absence of diffraction effects, the 2D ZRC design problem is known as the autocorrelation approximation. Based on the properties of the autocorrelation function, the design of the 2D ZRC is first formulated as a particular combination optimization problem. The CE method is then applied to search for an optimal 2D ZRC and thus obtain the desirable zero reference signal. Computer simulation results indicate that there are 15.38% and 14.29% reductions in the second maxima value for the 16x16 grating system with n(1)=64 and the 100x100 grating system with n(1)=300, respectively, where n(1) is the number of transparent pixels, compared with those of the conventional genetic algorithm.

Prediction of Depression in Cancer Patients With Different Classification Criteria, Linear Discriminant Analysis versus Logistic Regression.

PubMed

Shayan, Zahra; Mohammad Gholi Mezerji, Naser; Shayan, Leila; Naseri, Parisa

2015-11-03

Logistic regression (LR) and linear discriminant analysis (LDA) are two popular statistical models for prediction of group membership. Although they are very similar, the LDA makes more assumptions about the data. When categorical and continuous variables used simultaneously, the optimal choice between the two models is questionable. In most studies, classification error (CE) is used to discriminate between subjects in several groups, but this index is not suitable to predict the accuracy of the outcome. The present study compared LR and LDA models using classification indices. This cross-sectional study selected 243 cancer patients. Sample sets of different sizes (n = 50, 100, 150, 200, 220) were randomly selected and the CE, B, and Q classification indices were calculated by the LR and LDA models. CE revealed the a lack of superiority for one model over the other, but the results showed that LR performed better than LDA for the B and Q indices in all situations. No significant effect for sample size on CE was noted for selection of an optimal model. Assessment of the accuracy of prediction of real data indicated that the B and Q indices are appropriate for selection of an optimal model. The results of this study showed that LR performs better in some cases and LDA in others when based on CE. The CE index is not appropriate for classification, although the B and Q indices performed better and offered more efficient criteria for comparison and discrimination between groups.

Gardening Experience Is Associated with Increased Fruit and Vegetable Intake among First-Year College Students: A Cross-Sectional Examination.

PubMed

Loso, Jennifer; Staub, Daniel; Colby, Sarah E; Olfert, Melissa D; Kattelmann, Kendra; Vilaro, Melissa; Colee, James; Zhou, Wenjun; Franzen-Castle, Lisa; Mathews, Anne E

2018-02-01

Gardening interventions have been shown to increase fruit and vegetable (F/V) intake among school-aged children. It is unknown whether these effects persist into later adolescence or adulthood, and little is known about whether gardening in later adolescence is related to F/V intake. To identify the relationship between both childhood and recent (within the past 12 months) gardening experiences and current F/V intake among college students. A cross-sectional evaluation of 1,121 college freshmen with suboptimal F/V consumption from eight US universities. Participants completed the National Cancer Institute Fruit and Vegetable Screener and questions about gardening experiences. Respondents were grouped as having gardened or not gardened during childhood and recently. A linear mixed model was used to evaluate the relationship between childhood and recent gardening and current F/V intake. Of the student participants, 11% reported gardening only during childhood, 19% reported gardening only recently, 20% reported gardening both as a child and recently, and 49% of students reported never having gardened. Students who gardened both during childhood and recently had a significantly higher mean current intake of F/V compared with students who never gardened (2.5±0.6 vs 1.9±0.5 cup equivalents [CE], respectively; P<0.001). In addition, F/V intake increased with frequency of recent gardening engagement when comparing students who did not garden with those who gardened monthly or weekly (2.1±0.5 CE, 2.4±0.6 CE, and 2.8±0.7 CE, respectively; P<0.001). This analysis suggests that the combination of childhood and recent gardening experience is associated with greater current F/V intake among first-year college students not currently meeting national F/V recommendations. In addition, a greater frequency of gardening experience may further enhance this effect. Copyright © 2018 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

State of the art timing in TOF-PET detectors with LuAG, GAGG and L(Y)SO scintillators of various sizes coupled to FBK-SiPMs

NASA Astrophysics Data System (ADS)

Gundacker, S.; Acerbi, F.; Auffray, E.; Ferri, A.; Gola, A.; Nemallapudi, M. V.; Paternoster, G.; Piemonte, C.; Lecoq, P.

2016-08-01

Time of flight (TOF) in positron emission tomography (PET) has experienced a revival of interest after its first introduction in the eighties. This is due to a significant progress in solid state photodetectors (SiPMs) and newly developed scintillators (LSO and its derivatives). Latest developments at Fondazione Bruno Kessler (FBK) lead to the NUV-HD SiPM with a very high photon detection efficiency of around 55%. Despite the large area of 4×4 mm2 it achieves a good single photon time resolution (SPTR) of 180±5ps FWHM. Coincidence time resolution (CTR) measurements using LSO:Ce codoped with Ca scintillators yield best values of 73±2ps FWHM for 2×2×3 mm3 and 117±3ps for 2×2×20 mm3 crystal sizes. Increasing the crystal cross-section from 2×2 mm2 to 3×3 mm2 a non negligible CTR deterioration of approximately 7ps FWHM is observed. Measurements with LSO:Ce codoped Ca and LYSO:Ce scintillators with various cross-sections (1×1 mm2 - 4×4 mm2) and lengths (3mm - 30mm) will be a basis for discussing on how the crystal geometry affects timing in TOF-PET. Special attention is given to SiPM parameters, e.g. SPTR and optical crosstalk, and their measured dependency on the crystal cross-section. Additionally, CTR measurements with LuAG:Ce, LuAG:Pr and GGAG:Ce samples are presented and the results are interpreted in terms of their scintillation properties, e.g. rise time, decay time, light yield and emission spectra.

Computational methods for identifying miRNA sponge interactions.

PubMed

Le, Thuc Duy; Zhang, Junpeng; Liu, Lin; Li, Jiuyong

2017-07-01

Recent findings show that coding genes are not the only targets that miRNAs interact with. In fact, there is a pool of different RNAs competing with each other to attract miRNAs for interactions, thus acting as competing endogenous RNAs (ceRNAs). The ceRNAs indirectly regulate each other via the titration mechanism, i.e. the increasing concentration of a ceRNA will decrease the number of miRNAs that are available for interacting with other targets. The cross-talks between ceRNAs, i.e. their interactions mediated by miRNAs, have been identified as the drivers in many disease conditions, including cancers. In recent years, some computational methods have emerged for identifying ceRNA-ceRNA interactions. However, there remain great challenges and opportunities for developing computational methods to provide new insights into ceRNA regulatory mechanisms.In this paper, we review the publically available databases of ceRNA-ceRNA interactions and the computational methods for identifying ceRNA-ceRNA interactions (also known as miRNA sponge interactions). We also conduct a comparison study of the methods with a breast cancer dataset. Our aim is to provide a current snapshot of the advances of the computational methods in identifying miRNA sponge interactions and to discuss the remaining challenges. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Enhancement of red upconversion emission of cubic phase NaLuF{sub 4}: Yb{sup 3+}/Ho{sup 3+}/Ce{sup 3+} nanocrystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Wei, E-mail: gaowei@xupt.edu.com; Dong, Jun, E-mail: dongjun@xupt.edu.cn; Liu, Jihong

Highlights: • The upconversion emission of Ho{sup 3+} ions was tuned from green to red. • The upconversion mechanism of Ho{sup 3+} ions was discussed based on emission spectrum. • The conversion efficiency between Ho{sup 3+} and Ce{sup 3+} were studied and calculated. - Abstract: The red upconversion emission of lanthanide-doped fluoride nanocrystals have great potential applications in color display and anticounterfeiting applications, especially for biological imaging and biomedical. In this work, a significant enhancement of red upconversion emission of Ho{sup 3+} ions was successfully obtained in the cubic phase NaLuF{sub 4} nanocrystals through codoping Ce{sup 3+} ions under NIRmore » 980 nm excitation. The ratio of red-to-green emission of Ho{sup 3+} ions was enhanced about 10-fold, which is due to two efficient cross relaxation processes derived from Ho{sup 3+} and Ce{sup 3+} ions promoted the red emission and quenched the green emission. The upconversion emission and luminescent colors of NaLuF{sub 4}: Yb{sup 3+}/Ho{sup 3+} nanocrystals were carefully investigated by a confocal microscopy setup. The possible upconversion emission mechanism and conversion efficiency of cross relaxation between Ho{sup 3+} and Ce{sup 3+} ions were discussed in detail. The current study suggests that strong red emission of NaLuF{sub 4}: Yb{sup 3+}/Ho{sup 3+}/Ce{sup 3+} nanomaterials can be used for color display and anticounterfeiting techniques.« less

Low-cost and facile fabrication of a paper-based capillary electrophoresis microdevice for pathogen detection.

PubMed

Lee, Jee Won; Lee, Dohwan; Kim, Yong Tae; Lee, Eun Yeol; Kim, Do Hyun; Seo, Tae Seok

2017-05-15

This paper describes the development of a novel paper-based capillary electrophoresis (pCE) microdevice using mineral paper, which is durable, oil and tear resistant, and waterproof. The pCE device is inexpensive (~$1.6 per device for materials), simple to fabricate, lightweight, and disposable, so it is more adequate for point-of-care (POC) pathogen diagnostics than a conventional CE device made of glass, quartz, silicon or polymer. In addition, the entire fabrication process can be completed within 1h without using expensive clean room facilities and cumbersome photolithography procedures. A simple cross-designed pCE device was patterned on the mineral paper by using a plotter, and assembled with an OHP film via a double-sided adhesive film. After filling the microchannel with polyacrylamide gel, the injection, backbiasing, and separation steps were sequentially operated to differentiate single-stranded DNA (ssDNA) with 4 bp resolution in a 2.9cm-long CE separation channel. Furthermore, we successfully demonstrated the identification of the PCR amplicons of two target genes of Escherichia coli O157:H7 (rrsH gene, 121 bp) and Staphylococcus aureus (glnA gene, 225 bp). For accurate assignment of the peaks in the electropherogram, two bracket ladders (80 bp for the shortest and 326 bp for the longest) were employed, so the two amplicons of the pathogens were precisely identified on a pCE chip within 3min using the relative migration time ratio without effect of the CE environments. Thus, we believe that the pCE microdevice could be very useful for the separation of nucleic acids, amino acids, and ions as an analytical tool for use in the medical applications in the resource-limited environments as well as fundamental research fields. Copyright © 2016 Elsevier B.V. All rights reserved.

Dementia-Related Work Activities of Home Care Nurses and Aides: Frequency, Perceived Competence, and Continuing Education Priorities

ERIC Educational Resources Information Center

Morgan, Debra G.; Kosteniuk, Julie G.; O'Connell, Megan E.; Dal Bello-Haas, Vanina; Stewart, Norma J.; Karunanayake, Chandima

2016-01-01

An understanding of the specific dementia learning needs of home care staff is needed to plan relevant continuing education (CE) programs and supports. The study's objective was to examine frequency and perceived competence in performing 20 dementia-related work activities, and identify CE priorities among home care staff. A cross-sectional survey…

Monolithic Integration of Two-Dimensional Liquid Chromatography-Capillary Electrophoresis and Electrospray Ionization on a Microfluidic Device

PubMed Central

Chambers, Andrew G.; Mellors, J. Scott; Henley, W. Hampton; Ramsey, J. Michael

2011-01-01

A microfluidic device capable of two-dimensional reversed-phase liquid chromatography-capillary electrophoresis with integrated electrospray ionization (LC-CE-ESI) for mass spectrometry (MS)-based proteomic applications is described. Traditional instrumentation was used for the LC sample injection and delivery of the LC mobile phase. The glass microfabricated device incorporated a sample-trapping region and an LC channel packed with reversed-phase particles. Rapid electrokinetic injections of the LC effluent into the CE dimension were performed at a cross channel intersection. The CE separation channel terminated at a corner of the square device, which functioned as an integrated electrospray tip. In addition to LC-CE-ESI, this device was used for LC-ESI without any instrumental modifications. To evaluate the system, LC-MS and LC-CE-MS analysis of protein digests were performed and compared. PMID:21214194

Separation of sardine oil without heating from surimi waste and its effect on lipid metabolism in rats.

PubMed

Toyoshima, Kotoe; Noguchi, Ryoko; Hosokawa, Masashi; Fukunaga, Kenji; Nishiyama, Toshimasa; Takahashi, Riki; Miyashita, Kazuo

2004-04-21

Sardine oil was obtained by centrifugation of surimi wastewater without heating or chemical refining. This oil (CE) showed light yellow color and the peroxide value was less than 1.0 meq/kg. The main lipid class of CE was triacylglycerol (TG) (>99%). These features indicate that CE can be directly used as food materials without further purification. Commercial sardine oil (CO) is usually prepared via some kind of refining process with high temperature (250 degrees C) and chemical treatment. The comparative study on the physiological effects of these sardine oils (CE and CO) revealed that the dietary sardine oils were more effective in reducing abdominal fat pads, plasma total cholesterol, and TG levels of rats than was a soybean oil diet (control). Furthermore, these effects were greater in CE than CO, although there was little difference in the fatty acid composition of both oils. Although the main lipid class of CE was TG (>99%), CE was prepared by centrifugation from surimi waste and directly used as dietary fat without further purification. Therefore, CE may contain some kinds of minor components, which could be attributed to the higher physiological activity of CE. To reveal the involvement of the minor compounds in CE, we prepared TG from CE by column chromatography and measured its effect on lipid metabolism of rats. TG from CE also showed the reducing effects on abdominal fad pads and plasma lipid levels. The effect of TG from CE was almost the same as that of original CE, suggesting that the higher nutritional activity of CE than CO may not be due to the minor compounds in CE.

Effects of Ce additions on the age hardening response of Mg–Zn alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Langelier, Brian, E-mail: langelb@mcmaster.ca; Esmaeili, Shahrzad

2015-03-15

The effects of Ce additions on the precipitation hardening behaviour of Mg–Zn are examined for a series of alloys, with Ce additions at both alloying and microalloying levels. The alloys are artificially aged, and studied using hardness measurement and X-ray diffraction, as well as optical and transmission electron microscopy. It is found that the age-hardening effect is driven by the formation of fine precipitates, the number density of which is related to the Zn content of the alloy. Conversely, the Ce content is found to slightly reduce hardening. When the alloy content of Ce is high, large secondary phase particlesmore » containing both Ce and Zn are present, and remain stable during solutionizing. These particles effectively reduce the amount of Zn available as solute for precipitation, and thereby reduce hardening. Combining hardness results with thermodynamic analysis of alloy solute levels also suggests that Ce can have a negative effect on hardening when present as solutes at the onset of ageing. This effect is confirmed by designing a pre-ageing heat treatment to preferentially remove Ce solutes, which is found to restore the hardening capability of an Mg–Zn–Ce alloy to the level of the Ce-free alloy. - Highlights: • The effects of Ce additions on precipitation in Mg–Zn alloys are examined. • Additions of Ce to Mg–Zn slightly reduce the age-hardening response. • Ce-rich secondary phase particles deplete the matrix of Zn solute. • Hardening is also decreased when Ce is present in solution. • Pre-ageing to preferentially precipitate out Ce restores hardening capabilities.« less

Integrated polymerase chain reaction/electrophoresis instrument

DOEpatents

Andresen, Brian D.

2000-01-01

A new approach and instrument for field identification of micro-organisms and DNA fragments using a small and disposable device containing integrated polymerase chain reaction (PCR) enzymatic reaction wells, attached capillary electrophoresis (CE) channels, detectors, and read-out all on/in a small hand-held package. The analysis instrument may be made inexpensively, for example, of plastic, and thus is disposable, which minimizes cross contamination and the potential for false positive identification between samples. In addition, it is designed for multiple users with individual applications. The integrated PCR/CE is manufactured by the PCR well and CE channels are "stamped" into plastic depressions where conductive coatings are made in the wells and ends of the CE microchannels to carry voltage and current to heat the PCR reaction mixtures and simultaneously draw DNA bands up the CE channels. Light is transmitted through the instrument at appropriate points and detects PCR bands and identifies DNA fragments by size (retention time) and quantifies each by the amount of light generated as each phototransistor positioned below each CE channel detects a passing band. The instrument is so compact that at least 100 PCR/CE reactions/analyses can be performed easily on one detection device.

Functional integration of PCR amplification and capillary eletrophoresis in a microfabricated DNA analysis device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woolley, A.T.; deMello, A.J.; Mathies, R.A.

Microfabricated silicon PCR reactors and glass capillary electrophoresis (CE) chips have been successfully coupled to form an integrated DNA analysis system. This construct combines the rapid thermal cycling capabilities of microfabricated PCR devices (10{degree}C/s heating, 2.5{degree}C/s cooling) with the high-speed (<120 s) DNA separations provided by microfabricated CE chips. The PCR chamber and the CE chip were directly linked through a photolithographically fabricated channel filled with hydroxyethylcellulose sieving matrix. Electrophoretic injection directly from the PCR chamber through the cross injection channel was used as an `electrophoretic valve` to couple the PCR and CE devices on-chip. To demonstrate the functionality ofmore » this system, a 15 min PCR amplification of a {Beta}-globin target cloned in m13 was immediately followed by high-speed CE chip separation in under 120 s, providing a rapid PCR-CE analysis in under 20 min. A rapid assay for genomic Salmonella DNA was performed in under 45 min, demonstrating that challenging amplifications of diagnostically interesting targets can also be performed. Real-time monitoring of PCR target amplification in these integrated PCR-CE devices is also feasible. 33 refs., 6 figs.« less

Quantitative assessment of serum-specific IgE in the diagnosis of human cystic echinococcosis.

PubMed

Marinova, I; Nikolov, G; Michova, A; Kurdova, R; Petrunov, B

2011-07-01

Anti-Echinococcus serum immunoglobulin (Ig)E was assessed by the ImmunoCAP system and compared with anti-Echinococcus serum IgG assessed by enzyme-linked immunosorbent assay (ELISA) and Western blot. The ImmunoCAP system revealed very high specificity (one false positive of 110 healthy individuals), low cross-reactivity (one false positive of 58 patients with other diseases) and decreased sensitivity (73.55%). Receiver operating characteristic analysis displayed a beneficial diagnostic value with high accuracy. Comparison of the ImmunoCAP system with ELISA and Western blot showed significantly higher specificity and significantly lower cross-reactivity compared with the ELISA. Examination of sera from 155 patients with cystic echinococcosis (CE) showed varying levels of anti-Echinococcus IgE (range, 0.01-118.33 kUA/L). However, most samples had moderately elevated IgE levels. Analysis of serum-specific IgE revealed significantly higher sensitivity of the ImmunoCAP system and significantly higher antibody levels in hepatic CE compared with pulmonary CE. © 2011 Blackwell Publishing Ltd.

Plasma Centrifuge Heat Engine - a Route to Non-thermal p- 11 B Fusion

NASA Astrophysics Data System (ADS)

Barnes, D. C.

2007-06-01

An invention [US Patent and Trademark Office App. Nos. 60/596567 (2005) and 60/766791 (2006)] combines centrifugal and dipole confinement, with recent oscillating plasma theory. The plasma undergoes compression/expansion (C/E), parallel to B by centrifugal force and perpendicular to B by B variation, providing a thermal cycle which recovers most (>95%) of heating as mechanical energy. This gives a "Q-amplifier" for beam-target systems. Centrifugally confined Boron plasma undergoes C/E by slow, cross-B interchange activity. Parallel and perpendicular C/E are matched by the rotation profile which arises naturally. Hot plasma is heated and cold plasma is cooled. Beam-target fusion reactions occur in the hot plasma region and expansion returns most of the heat energy as rotation energy. Rotation energy, in turn, produces waves which drive protons to an energy near the fusion peak cross section. A possible machine, including the arrangement of magnets and HV, is described.

Osteoconduction of impacted porous titanium particles with a calcium-phosphate coating is comparable to osteoconduction of impacted allograft bone particles: in vivo study in a nonloaded goat model.

PubMed

Walschot, Lucas H B; Aquarius, René; Schreurs, Barend W; Verdonschot, Nico; Buma, Pieter

2012-08-01

Impaction grafting restores bone defects in hip arthroplasty. Defects are reconstructed with bone particles (BoP) as substitute materials with adequate mechanical and biological properties are not yet available. Ceramic particles (CeP) have mechanical drawbacks as opposed to porous titanium particles (TiP). In this in vivo study, bone ingrowth and bone volume in coated and noncoated TiP were compared to porous biphasic calcium-phospate CeP and allograft BoP. Coatings consisted of silicated calcium-phosphate and carbonated apatite. Materials were implanted in goats and impacted in cylindrical defects (diameter 8 mm) in the cancellous bone of the femur. On the basis of fluorochrome labeling and histology, bone ingrowth distance was measured at 4, 8, and 12 weeks. Cross-sectional bone area was measured at 12 weeks. TiP created a coherent matrix of entangled particles. CeP pulverized and were noncoherent. Bone ingrowth in TiP improved significantly by the coatings to levels comparable to BoP and CeP. Cross-sectional bone area was smaller in CeP and TiP compared to BoP. The osteoconductive properties of impacted TiP with a calcium-phosphate coating are comparable to impacted allograft bone and impacted biphasic ceramics. A more realistic loaded in vivo study should prove that coated TiP is an attractive alternative to allograft bone. Copyright © 2012 Wiley Periodicals, Inc.

Controllable upconversion luminescence and temperature sensing behavior in NaGdF4:Yb3+/Ho3+/Ce3+ nano-phosphors

NASA Astrophysics Data System (ADS)

Pang, Tao; Wang, Jiajun

2018-01-01

The hexagonal NaGdF4:Yb3+/Ho3+/Ce3+ nano-phosphors are synthesized by a hydrothermal method. Under 980 nm excitation, the phosphor emits green, red and far-red light in the visible wavelength region, corresponding to the 5S2/5F4 → 5I8, 5F5 → 5I8 and 5S2/5F4 → 5I7 transitions of Ho3+ ions, respectively. When adjusting the Ce3+ concentration from 0% to 16%, the dominant wavelength shifts ˜43 nm toward the longer wavelength. Two cross-relaxation processes between Ho3+ and Ce3+ are responsible for the change in chromaticity. Also, the ability of the Ce3+ concentration to regulate the luminescence color depends on the pumping power and temperature of samples. More interestingly, the phosphors are potentially applicable as the optical thermometric materials. In the case of 16% Ce3+ doping, the maximum sensitivity (0.1446 K-1) about 4-35 times as high as the reported values of several typical thermometric materials is obtained.

Further considerations of the Ce/Yb vs. Ba/Ce plot in volcanology and tectonics

USGS Publications Warehouse

Doe, B.R.

2002-01-01

A plot of Ce/Yh vs. Bd/Ce, for locality averages, effectively separates mid-ocean ridge basalts (MORB) (Ce/Yb 10, Ba/Ce 4.2). The conventional interpretation is that these three types of volcanic environments involve oceanic rift-related, large-volume partial melts (???20-30%) of a depleted source. (MORB), small volume melts (???5% for alkalic volcanics) of enriched sources related to plumes (OIV), and melts of hydrous-enriched sources during subduction, especially for Ba (IAV). There OIV sites, however, have average ratios that fall in the MORB field (e.g., Krafla Volcano, Iceland), and these localities also tend to have other geochemical data similar to MORB. Average ratios of Hawaiian tholeiitic shield basalts of Mauna Kea and Koolau volcanoes occupy a restricted field on a plot of Ce/Yb vs. Ba/Ce of 1O-18 for Ce/Yb and 2.8-3.1 for Ba/Ce, a field toward which other shield basalts and cone-building volcanics regress. In general, post-shield alkalic rocks have higher values of Ce/Yb than do tholeiites. Peralkalic basalts (basanites, melilitites, and phonolites) have even higher values of Ce/Yb, reflecting smaller degrees of partial melting (perhaps 1-2%) and melting of sources containing phlogopite that were enriched by CO2-dominated fluids. The minor post-erosion nephelinitic suites of Hawaii (e.g., the Honolulu Series on Oahu, and the Koloa suite on Kauai) generally have values both greater than IAV for Ce/Yb and greater than other kinds of OIV for Ba/Ce in a part of the plot previously not found to be occupied by data. Alkali basalts of both these nephelinitic series have the lowest and similar ratios (Ce/Yb ??? 25; Ba/Ce ??? 10). In the Hawaiian Islands. there are two trends. One (a), where phlogopite has heen interpreted tp remain in the source. generally has Ba/Ce decrease away from the alkali basalts as Ce/Yb increases. The other (b), where phlogopite has heen interpreted to enter the melt, occupies a field that is high in both Ce/Yb (>30) relative to IAV and in Ba/Ce (>8) relative to the OIV field. There are some exceptions, also, for IAV that plot outside the IAV field. The values of Ce/Yb in Mariana Islands samples, for example, are exceptionally low for the IAV (Ce/Yb <5 with many samples <2). Examples of two cross-chain Kasuga Islands, however, have average, values of Ce/Yb considerably greater than for any other Mariana Islands data, and individual samples extend from within the IAV field into the OIV field, which may indicate a mixture of IAV and OIV sources (rather than involvement of a hotspot, these island volcanics have been interpreted as magma of OIV entrapped "plums" in an IAV "pudding" by Stern et al., 1993). Not Surprisingly, continental are volcanics, (CAV) are generally similar to IAV, but with somewhat greater dispersion in Ce/Yb, perhaps representing a larger contribution of continental materials to the volcanics. Continental rift volcanics (CRV) are complex. The Antarctic rift data fall in the OIV field, and clearly define a hotspot origin for the rift with little contamination in the continental lithosphere, but most CRV data fall in the IAV field (Rio Grande rift tholeiites, Yellowstone Plateau basalts, Columbia River basalts. East African rift hasalts). The Yellowstone basalt samples judged to be least crustally contaminated from other considerations (e.g., through Pb and Sr isotopes) approach closest to the OIV or hotspot field in the Ce/Yb vs. Ba/Ce plot, compatible with a hotspot origin with variable continental lithosphere interactions. The data from the Rio Grande rift have no such trend in Ce/Yb vs. Ba/Ce. Other trace element and isotopic data are suggestive of a different kind of origin, perhaps melting in the continental lithosphere from pressure release or other causes as suggested in the literature. Carbonatites, kimberlites, and ultrap

The Information System at CeSAM

NASA Astrophysics Data System (ADS)

Agneray, F.; Gimenez, S.; Moreau, C.; Roehlly, Y.

2012-09-01

Modern large observational programmes produce important amounts of data from various origins, and need high level quality control, fast data access via easy-to-use graphic interfaces, as well as possibility to cross-correlate informations coming from different observations. The Centre de donnéeS Astrophysique de Marseille (CeSAM) offer web access to VO compliant Information Systems to access data of different projects (VVDS, HeDAM, EXODAT, HST-COSMOS,…), including ancillary data obtained outside Laboratoire d'Astrophysique de Marseille (LAM) control. The CeSAM Information Systems provides download of catalogues and some additional services like: search, extract and display imaging and spectroscopic data by multi-criteria and Cone Search interfaces.

Stop identity cue as a cue to language identity

NASA Astrophysics Data System (ADS)

Castonguay, Paula Lisa

The purpose of the present study was to determine whether language membership could potentially be cued by the acoustic-phonetic detail of word-initial stops and retained all the way through the process of lexical access to aid in language identification. Of particular interest were language-specific differences in CE and CF word-initial stops. Experiment 1 consisted of an interlingual homophone production task. The purpose of this study was to examine how word-initial stop consonants differ in terms of acoustic properties in Canadian English (CE) and Canadian French (CF) interlingual homophones. The analyses from the bilingual speakers in Experiment 1 indicate that bilinguals do produce language-specific differences in CE and CF word-initial stops, and that closure duration, voice onset time, and burst spectral SD may provide cues to language identity in CE and CF stops. Experiment 2 consisted of a Phoneme and Language Categorization task. The purpose of this study was to examine how stop identity cues, such as VOT and closure duration, influence a listener to identify word-initial stop consonants as belonging to Canadian English (CE) or Canadian French (CF). The RTs from the bilingual listeners in this study indicate that bilinguals do perceive language-specific differences in CE and CF word-initial stops, and that voice onset time may provide cues to phoneme and language membership in CE and CF stops. Experiment 3 consisted of a Phonological-Semantic priming task. The purpose of this study was to examine how subphonetic variations, such as changes in the VOT, affect lexical access. The results of Experiment 3 suggest that language-specific cues, such as VOT, affects the composition of the bilingual cohort and that the extent to which English and/or French words are activated is dependent on the language-specific cues present in a word. The findings of this study enhanced our theoretical understanding of lexical structure and lexical access in bilingual speakers. In addition, this study provides further insight on cross-language effects at the subphonetic level.

First upper limits on the radar cross section of cosmic-ray induced extensive air showers

NASA Astrophysics Data System (ADS)

Abbasi, R. U.; Abe, M.; Abou Bakr Othman, M.; Abu-Zayyad, T.; Allen, M.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Besson, D.; Blake, S. A.; Byrne, M.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Farhang-Boroujeny, B.; Fujii, T.; Fukushima, M.; Gillman, W. H.; Goto, T.; Hanlon, W.; Hanson, J. C.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jayanthmurthy, C.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kunwar, S.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, K.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nonaka, T.; Nozato, A.; Ogio, S.; Ogura, J.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Prohira, S.; Pshirkov, M. S.; Rezazadeh-Reyhani, A.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Schurig, D.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Suzawa, T.; Takai, H.; Takamura, M.; Takeda, M.; Takeishi, R.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Venkatesh, S.; Wong, T.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

2017-01-01

TARA (Telescope Array Radar) is a cosmic ray radar detection experiment colocated with Telescope Array, the conventional surface scintillation detector (SD) and fluorescence telescope detector (FD) near Delta, Utah, U.S.A. The TARA detector combines a 40 kW, 54.1 MHz VHF transmitter and high-gain transmitting antenna which broadcasts the radar carrier over the SD array and within the FD field of view, towards a 250 MS/s DAQ receiver. TARA has been collecting data since 2013 with the primary goal of observing the radar signatures of extensive air showers (EAS). Simulations indicate that echoes are expected to be short in duration (∼ 10 μs) and exhibit rapidly changing frequency, with rates on the order 1 MHz/μs. The EAS radar cross-section (RCS) is currently unknown although it is the subject of over 70 years of speculation. A novel signal search technique is described in which the expected radar echo of a particular air shower is used as a matched filter template and compared to waveforms obtained by triggering the radar DAQ using the Telescope Array fluorescence detector. No evidence for the scattering of radio frequency radiation by EAS is obtained to date. We report the first quantitative RCS upper limits using EAS that triggered the Telescope Array Fluorescence Detector. The transmitter is under the direct control of experimenters, and in a radio-quiet area isolated from other radio frequency (RF) sources. The power and radiation pattern are known at all times. Forward power up to 40 kW and gain exceeding 20 dB maximize energy density in the radar field. Continuous wave (CW) transmission gives 100% duty cycle, as opposed to pulsed radar. TARA utilizes a high sample rate DAQ (250 MS/s). TARA is colocated with a large state-of-the-art conventional CR observatory, allowing the radar data stream to be sampled at the arrival times of known cosmic ray events. Each of these attributes of the TARA detector has been discussed in detail in the literature [8]. A map showing the TA SD array and the location of the TARA transmitter and receiver is shown in Fig. 1.Section 2 of this paper includes a description of air shower plasmas and possible radio scattering mechanisms. Theoretical and experimental parameters that influence radio scattering are presented and discussed. We justify use of the thin wire model in a radar echo simulation that predicts echo waveforms, which we will subsequently (Section 6) use in placing limits on the air shower radar cross section (RCS). Sections 3 and 4 describe TARA data and offline processing techniques. In Section 5, we describe the signal search using simulated waveforms as matched filter (MF) templates in order to maximize sensitivity. Section 6 describes the procedure for calculating a scale factor to the RCS model described in Section 2, the results of which are used in placing the first quantitative upper limit on the EAS radar cross-section (RCS). In Section 7 we summarize these results and discuss the viability of radar detection of cosmic rays in light of the TARA findings.

Measurement of Lα and Lβ1,3,4 fluorescence cross sections of La, Ce, Pr and Nd induced by photons of energies between 7.01 keV and 8.75 keV

NASA Astrophysics Data System (ADS)

Reyes-Herrera, J.; Miranda, J.

2016-06-01

This study presents measurement results of x-ray production cross sections of Lα and Lβ1,3,4 emitted by four lanthanoid elements (La, Ce, Pr and Nd), after irradiation with Kα and Kβ X rays of the elements Co, Ni, Cu, and Zn (covering energies between 7.01 keV and 8.75 keV). Primary x-rays were induced in turn by the irradiation of thick targets of these elements with a beam of x-rays produced by a tube with an Rh anode, operating at 50 kV and 850 μA. The experimental results are compared with theoretical cross sections predicted using known tabulations of photoelectric cross sections. Dirac-Hartree-Slater (DHS) atomic parameters were used for these calculations. An acceptable match between experiment and both sets of tabulated data is found.

PceRBase: a database of plant competing endogenous RNA.

PubMed

Yuan, Chunhui; Meng, Xianwen; Li, Xue; Illing, Nicola; Ingle, Robert A; Wang, Jingjing; Chen, Ming

2017-01-04

Competition for microRNA (miRNA) binding between RNA molecules has emerged as a novel mechanism for the regulation of eukaryotic gene expression. Competing endogenous RNA (ceRNA) can act as decoys for miRNA binding, thereby forming a ceRNA network by regulating the abundance of other RNA transcripts which share the same or similar microRNA response elements. Although this type of RNA cross talk was first described in Arabidopsis, and was subsequently shown to be active in animal models, there is no database collecting potential ceRNA data for plants. We have developed a Plant ceRNA database (PceRBase, http://bis.zju.edu.cn/pcernadb/index.jsp) which contains potential ceRNA target-target, and ceRNA target-mimic pairs from 26 plant species. For example, in Arabidopsis lyrata, 311 candidate ceRNAs are identified which could affect 2646 target-miRNA-target interactions. Predicted pairing structure between miRNAs and their target mRNA transcripts, expression levels of ceRNA pairs and associated GO annotations are also stored in the database. A web interface provides convenient browsing and searching for specific genes of interest. Tools are available for the visualization and enrichment analysis of genes in the ceRNA networks. Moreover, users can use PceRBase to predict novel competing mimic-target and target-target interactions from their own data. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Tuning into single-band red upconversion luminescence in Yb(3+)/Ho(3+) activated nano-glass-ceramics through Ce(3+) doping.

PubMed

Chen, Daqin; Zhou, Yang; Wan, Zhongyi; Ji, Zhenguo; Huang, Ping

2015-03-28

Yb(3+)/Ho(3+) activated glass ceramics containing β-YF3 nanocrystals were successfully fabricated. The green ((5)S2/(5)F4→(5)I8) upconversion emission is dominant in the glass ceramics and is about 160 times stronger than that of the precursor glass, resulting from the partition of lanthanide activators into a low-phonon-energy crystalline lattice and the subsequent low probability of multi-phonon nonradiative relaxation from the (5)S2/(5)F4 and (5)I6 states to the lower ones. Upon the introduction of Ce(3+) ions into nano-glass-ceramics, two efficient cross-relaxation processes between Ho(3+) and Ce(3+), i.e., Ho(3+):(5)S2/(5)F4 + Ce(3+):(2)F5/2→Ho(3+):(5)F5 + Ce(3+):(2)F7/2 and Ho(3+):(5)I6 + Ce(3+):(2)F5/2→Ho(3+):(5)I7 + Ce(3+):(2)F7/2, are demonstrated to greatly suppress the population of the green-emitting (5)S2/(5)F4 state and to enhance the population of the red-emitting (5)F5 one, leading to the intense single-band red UC radiation of Ho(3+).

Prototyping of Poly(dimethylsiloxane) Interfaces for Flow Gating, Reagent Mixing, and Tubing Connection in Capillary Electrophoresis

PubMed Central

Zhang, Qiyang; Gong, Maojun

2014-01-01

Integrated microfluidic systems coupled with electrophoretic separations have broad application in biological and chemical analysis. Interfaces for the connection of various functional parts play a major role in the performance of a system. Here we developed a rapid prototyping method to fabricate monolithic poly(dimethylsiloxane) (PDMS) Interfaces for flow-gated injection, online reagent mixing, and tube-to-tube connection in an integrated capillary electrophoresis (CE) system. The basic idea was based on the properties of PDMS: elasticity, transparency, and suitability for prototyping. The molds for these interfaces were prepared by using commercially available stainless steel wires and nylon lines or silica capillaries. A steel wire was inserted through the diameter of a nylon line and a cross format was obtained as the mold for PDMS casting of flow gates and 4-way mixers. These interfaces accommodated tubing connection through PDMS elasticity and provided easy visual trouble shooting. The flow gate used smaller channel diameters thus reducing flow rate by 25 fold for effective gating compared with mechanically machined counterparts. Both PDMS mixers and the tube-to-tube connectors could minimize the sample dead volume by using an appropriate capillary configuration. As a whole, the prototyped PDMS interfaces are reusable, inexpensive, convenient for connection, and robust when integrated with the CE detection system. Therefore, these interfaces could see potential applications in CE and CE-coupled systems. PMID:24331370

Evaluation of the Coaches Educators training implementation of the PAPA project: A comparison between Norway and France.

PubMed

Van Hoye, A; Larsen, T; Sovik, M; Wold, B; Heuzé, J-P; Samdal, O; Ommundsen, Y; Sarrazin, P

2015-10-01

This study cross-culturally compares the implementation process of the Empowering Coaching™ training program to grassroots coaches (GCs) by trained Coach Educators (CEs) from the Promoting Adolescent Physical Activity project in Norway and France. This program targets children's health through coach training to create a more positive environment. Using the RE-AIM framework, indicators of implementation processes at staff level were defined for adoption, implementation, and maintenance. CEs (n = 18) were interviewed about their professional use of the training, and video-filmed delivering the intervention trial workshops. GCs (n = 185) responded to a questionnaire after the workshops. Results showed that CEs were keen to participate in this project (16/18; 89%), to stay involved (12/16; 75%), and to diffuse the principles after the research project (12/12; 100%). CE training seemed effective as results indicated that CEs applied the principles of the program during the workshops and covered a high degree of the content (78%). Cross-cultural differences were found as the French Football Federation CE dropped out of the program, as Norwegian CEs delivered the content with higher fidelity and had higher enjoyment and pace scores than French CEs. More indicators are needed to use the RE-AIM framework for cross-cultural comparison. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of feedback techniques for lower back pain on gluteus maximus and oblique abdominal muscle activity and angle of pelvic rotation during the clam exercise.

PubMed

Koh, Eun-Kyung; Park, Kyue-Nam; Jung, Do-Young

2016-11-01

This study was conducted in order to determine the effect of feedback tools on activities of the gluteus maximus (Gmax) and oblique abdominal muscles and the angle of pelvic rotation during clam exercise (CE). Comparative study using repeated measures. University laboratory. Sixteen subjects with lower back pain. Each subject performed the CE without feedback, the CE using a pressure biofeedback unit (CE-PBU), and the CE with palpation and visual feedback (CE-PVF). Electromyographic (EMG) activity and the angles of pelvic rotation were measured using surface EMG and a three-dimensional motion-analysis system, respectively. One-way repeated-measures ANOVA followed by the Bonferroni post hoc test were used to compare the EMG activity in each muscle as well as the angle of pelvic rotation during the CE, CE-PBU, and CE-PVF. The results of post-hoc testing showed a significantly reduced angle of pelvic rotation and significantly more Gmax EMG activity during the CE-PVF compared with during the CE and CE-PBU. These findings suggest that palpation and visual feedback is effective for activating the Gmax and controlling pelvic rotation during the CE in subjects with lower back pain. Copyright © 2016 Elsevier Ltd. All rights reserved.

The competing effects of microbially derived polymeric and low molecular-weight substances on the dispersibility of CeO2 nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakano, Yuriko; Ochiai, Asumi; Kawamoto, Keisuke

To understand the competing effects of the components in extracellular substances (ES), polymeric substances (PS) and low-molecular-weight small substances (SS) <1 kDa derived from microorganisms, on the colloidal stability of cerium dioxide nanoparticles (CeNPs), we investigated their adsorption to sparingly soluble CeNPs at room temperature at pH 6.0. The ES was extracted from the fungus S. cerevisiae. The polypeptides and phosphates in all components preferentially adsorbed onto the CeNPs. The zeta potentials of ES + CeNPs, PS + CeNPs, and SS + CeNPs overlapped on the plot of PS itself, indicating the surface charge of the polymeric substances controls themore » zeta potentials. The sizes of the CeNP aggregates, 100–1300 nm, were constrained by the zeta potentials. The steric barrier derived from the polymers, even in SS, enhanced the CeNP dispersibility at pH 1.5–10. Consequently, the PS and SS had similar effects on modifying the CeNP surfaces. The adsorption of ES, which contains PS + SS, can suppress the aggregation of CeNPs over a wider pH range than that for PS only. The present study addresses the non-negligible effects of small-sized molecules derived from microbial activity on the migration of CeNP in aquatic environments, especially where bacterial consortia prevail.« less

Quantum mechanical theory of dynamic nuclear polarization in solid dielectrics.

PubMed

Hu, Kan-Nian; Debelouchina, Galia T; Smith, Albert A; Griffin, Robert G

2011-03-28

Microwave driven dynamic nuclear polarization (DNP) is a process in which the large polarization present in an electron spin reservoir is transferred to nuclei, thereby enhancing NMR signal intensities. In solid dielectrics there are three mechanisms that mediate this transfer--the solid effect (SE), the cross effect (CE), and thermal mixing (TM). Historically these mechanisms have been discussed theoretically using thermodynamic parameters and average spin interactions. However, the SE and the CE can also be modeled quantum mechanically with a system consisting of a small number of spins and the results provide a foundation for the calculations involving TM. In the case of the SE, a single electron-nuclear spin pair is sufficient to explain the polarization mechanism, while the CE requires participation of two electrons and a nuclear spin, and can be used to understand the improved DNP enhancements observed using biradical polarizing agents. Calculations establish the relations among the electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) frequencies and the microwave irradiation frequency that must be satisfied for polarization transfer via the SE or the CE. In particular, if δ, Δ < ω(0I), where δ and Δ are the homogeneous linewidth and inhomogeneous breadth of the EPR spectrum, respectively, we verify that the SE occurs when ω(M) = ω(0S) ± ω(0I), where ω(M), ω(0S) and ω(0I) are, respectively, the microwave, and the EPR and NMR frequencies. Alternatively, when Δ > ω(0I) > δ, the CE dominates the polarization transfer. This two-electron process is optimized when ω(0S(1))-ω(0S(2)) = ω(0I) and ω(M)~ω(0S(1)) or ω(0S(2)), where ω(0S(1)) and ω(0S(2)) are the EPR Larmor frequencies of the two electrons. Using these matching conditions, we calculate the evolution of the density operator from electron Zeeman order to nuclear Zeeman order for both the SE and the CE. The results provide insights into the influence of the microwave irradiation field, the external magnetic field, and the electron-electron and electron-nuclear interactions on DNP enhancements.

Measurement of Cerium and Gadolinium in Solid Lithium Chloride-Potassium Chloride Salt Using Laser-Induced Breakdown Spectroscopy (LIBS).

PubMed

Williams, Ammon; Bryce, Keith; Phongikaroon, Supathorn

2017-10-01

Pyroprocessing of used nuclear fuel (UNF) has many advantages-including that it is proliferation resistant. However, as part of the process, special nuclear materials accumulate in the electrolyte salt and present material accountability and safeguards concerns. The main motivation of this work was to explore a laser-induced breakdown spectroscopy (LIBS) approach as an online monitoring technique to enhance the material accountability of special nuclear materials in pyroprocessing. In this work, a vacuum extraction method was used to draw the molten salt (CeCl 3 -GdCl 3 -LiCl-KCl) up into 4 mm diameter Pyrex tubes where it froze. The salt was then removed and the solid salt was measured using LIBS and inductively coupled plasma mass spectroscopy (ICP-MS). A total of 36 samples were made that varied the CeCl 3 and GdCl 3 (surrogates for uranium and plutonium, respectively) concentrations from 0.5 wt% to 5 wt%. From these samples, univariate calibration curves for Ce and Gd were generated using peak area and peak intensity methods. For Ce, the Ce 551.1 nm line using the peak area provided the best calibration curve with a limit of detection (LOD) of 0.099 wt% and a root mean squared error of cross-validation (RMSECV) of 0.197 wt%. For Gd, the best curve was generated using the peak intensities of the Gd 564.2 nm line resulting in a LOD of 0.027 wt% and a RMSECV of 0.295 wt%. The RMSECV for the univariate cases were determined using leave-one-out cross-validation. In addition to the univariate calibration curves, partial least squares (PLS) regression was done to develop a calibration model. The PLS models yielded similar results with RMSECV (determined using Venetian blind cross-validation with 17% left out per split) values of 0.30 wt% and 0.29 wt% for Ce and Gd, respectively. This work has shown that solid pyroprocessing salt can be qualitatively and quantitatively monitored using LIBS. This work has the potential of significantly enhancing the material monitoring and safeguards of special nuclear materials in pyroprocessing.

DYNAMICS AND STAGNATION IN THE MALTHUSIAN EPOCH.

PubMed

Ashraf, Quamrul; Galor, Oded

2011-08-01

This paper examines the central hypothesis of the influential Malthusian theory, according to which improvements in the technological environment during the pre-industrial era had generated only temporary gains in income per capita, eventually leading to a larger, but not significantly richer, population. Exploiting exogenous sources of cross-country variations in land productivity and the level of technological advancement the analysis demonstrates that, in accordance with the theory, technological superiority and higher land productivity had significant positive effects on population density but insignificant effects on the standard of living, during the time period 1-1500 CE.

Determination of optimum threshold values for EMG time domain features; a multi-dataset investigation

NASA Astrophysics Data System (ADS)

Nlandu Kamavuako, Ernest; Scheme, Erik Justin; Englehart, Kevin Brian

2016-08-01

Objective. For over two decades, Hudgins’ set of time domain features have extensively been applied for classification of hand motions. The calculation of slope sign change and zero crossing features uses a threshold to attenuate the effect of background noise. However, there is no consensus on the optimum threshold value. In this study, we investigate for the first time the effect of threshold selection on the feature space and classification accuracy using multiple datasets. Approach. In the first part, four datasets were used, and classification error (CE), separability index, scatter matrix separability criterion, and cardinality of the features were used as performance measures. In the second part, data from eight classes were collected during two separate days with two days in between from eight able-bodied subjects. The threshold for each feature was computed as a factor (R = 0:0.01:4) times the average root mean square of data during rest. For each day, we quantified CE for R = 0 (CEr0) and minimum error (CEbest). Moreover, a cross day threshold validation was applied where, for example, CE of day two (CEodt) is computed based on optimum threshold from day one and vice versa. Finally, we quantified the effect of the threshold when using training data from one day and test data of the other. Main results. All performance metrics generally degraded with increasing threshold values. On average, CEbest (5.26 ± 2.42%) was significantly better than CEr0 (7.51 ± 2.41%, P = 0.018), and CEodt (7.50 ± 2.50%, P = 0.021). During the two-fold validation between days, CEbest performed similar to CEr0. Interestingly, when using the threshold values optimized per subject from day one and day two respectively, on the cross-days classification, the performance decreased. Significance. We have demonstrated that threshold value has a strong impact on the feature space and that an optimum threshold can be quantified. However, this optimum threshold is highly data and subject driven and thus do not generalize well. There is a strong evidence that R = 0 provides a good trade-off between system performance and generalization. These findings are important for practical use of pattern recognition based myoelectric control.

Determination of optimum threshold values for EMG time domain features; a multi-dataset investigation.

PubMed

Kamavuako, Ernest Nlandu; Scheme, Erik Justin; Englehart, Kevin Brian

2016-08-01

For over two decades, Hudgins' set of time domain features have extensively been applied for classification of hand motions. The calculation of slope sign change and zero crossing features uses a threshold to attenuate the effect of background noise. However, there is no consensus on the optimum threshold value. In this study, we investigate for the first time the effect of threshold selection on the feature space and classification accuracy using multiple datasets. In the first part, four datasets were used, and classification error (CE), separability index, scatter matrix separability criterion, and cardinality of the features were used as performance measures. In the second part, data from eight classes were collected during two separate days with two days in between from eight able-bodied subjects. The threshold for each feature was computed as a factor (R = 0:0.01:4) times the average root mean square of data during rest. For each day, we quantified CE for R = 0 (CEr0) and minimum error (CEbest). Moreover, a cross day threshold validation was applied where, for example, CE of day two (CEodt) is computed based on optimum threshold from day one and vice versa. Finally, we quantified the effect of the threshold when using training data from one day and test data of the other. All performance metrics generally degraded with increasing threshold values. On average, CEbest (5.26 ± 2.42%) was significantly better than CEr0 (7.51 ± 2.41%, P = 0.018), and CEodt (7.50 ± 2.50%, P = 0.021). During the two-fold validation between days, CEbest performed similar to CEr0. Interestingly, when using the threshold values optimized per subject from day one and day two respectively, on the cross-days classification, the performance decreased. We have demonstrated that threshold value has a strong impact on the feature space and that an optimum threshold can be quantified. However, this optimum threshold is highly data and subject driven and thus do not generalize well. There is a strong evidence that R = 0 provides a good trade-off between system performance and generalization. These findings are important for practical use of pattern recognition based myoelectric control.

Transition of Emission Colours as a Consequence of Heat-Treatment of Carbon Coated Ce3+-Doped YAG Phosphors

PubMed Central

Yin, Liang-Jun; Dierre, Benjamin; Sekiguchi, Takashi; van Ommen, J. Ruud; Hintzen, Hubertus T. (Bert); Cho, Yujin

2017-01-01

To modify the luminescence properties of Ce3+-doped Y3Al5O12 (YAG) phosphors, they have been coated with a carbon layer by chemical vapor deposition and subsequently heat-treated at high temperature under N2 atmosphere. Luminescence of the carbon coated YAG:Ce3+ phosphors has been investigated as a function of heat-treatment at 1500 and 1650 °C. The 540 nm emission intensity of C@YAG:Ce3+ is the highest when heated at 1650 °C, while a blue emission at 400–420 nm is observed when heated at 1500 °C but not at 1650 °C. It is verified by X-ray diffraction (XRD) that the intriguing luminescence changes are induced by the formation of new phases in C@YAG:Ce3+-1500 °C, which disappear in C@YAG:Ce3+-1650 °C. In order to understand the mechanisms responsible for the enhancement of YAG:Ce3+ emission and the presence of the blue emission observed for C@YAG:Ce3+-1500 °C, the samples have been investigated by a combination of several electron microscopy techniques, such as HRTEM, SEM-CL, and SEM-EDS. This local and cross-sectional analysis clearly reveals a gradual transformation of phase and morphology in heated C@YAG:Ce3+ phosphors, which is related to a reaction between C and YAG:Ce3+ in N2 atmosphere. Through reaction between the carbon layer and YAG host materials, the emission colour of the phosphors can be modified from yellow, white, and then back to yellow under UV excitation as a function of heat-treatment in N2 atmosphere. PMID:29035336

Transition of Emission Colours as a Consequence of Heat-Treatment of Carbon Coated Ce3+-Doped YAG Phosphors.

PubMed

Yin, Liang-Jun; Dierre, Benjamin; Sekiguchi, Takashi; van Ommen, J Ruud; Hintzen, Hubertus T Bert; Cho, Yujin

2017-10-16

To modify the luminescence properties of Ce 3+ -doped Y₃Al₅O 12 (YAG) phosphors, they have been coated with a carbon layer by chemical vapor deposition and subsequently heat-treated at high temperature under N₂ atmosphere. Luminescence of the carbon coated YAG:Ce 3+ phosphors has been investigated as a function of heat-treatment at 1500 and 1650 °C. The 540 nm emission intensity of C@YAG:Ce 3+ is the highest when heated at 1650 °C, while a blue emission at 400-420 nm is observed when heated at 1500 °C but not at 1650 °C. It is verified by X-ray diffraction (XRD) that the intriguing luminescence changes are induced by the formation of new phases in C@YAG:Ce 3+ -1500 °C, which disappear in C@YAG:Ce 3+ -1650 °C. In order to understand the mechanisms responsible for the enhancement of YAG:Ce 3+ emission and the presence of the blue emission observed for C@YAG:Ce 3+ -1500 °C, the samples have been investigated by a combination of several electron microscopy techniques, such as HRTEM, SEM-CL, and SEM-EDS. This local and cross-sectional analysis clearly reveals a gradual transformation of phase and morphology in heated C@YAG:Ce 3+ phosphors, which is related to a reaction between C and YAG:Ce 3+ in N₂ atmosphere. Through reaction between the carbon layer and YAG host materials, the emission colour of the phosphors can be modified from yellow, white, and then back to yellow under UV excitation as a function of heat-treatment in N₂ atmosphere.

Nursing students' perceptions of using the Clinical Education Assessment tool AssCE and their overall perceptions of the clinical learning environment - A cross-sectional correlational study.

PubMed

Engström, Maria; Löfmark, Anna; Vae, Karen Johanne Ugland; Mårtensson, Gunilla

2017-04-01

Clinical education is a vital part of nursing students' learning; the importance of assessment tools and feedback in stimulating student learning has been stressed, but this needs to be studied in more detail. To examine relationships between nursing students' perceptions of using an Assessment tool in Clinical Education (AssCE) during their mid-course discussion and final assessment, the content discussed during these meetings between the student, preceptor and nurse teacher and the students' overall perception of the clinical learning environment. A cross-sectional, correlational design was used. A convenience sample of 110 nursing students from one Norwegian university college with two campuses. Data were collected with self-developed questionnaires and analysed using logistic regression with SPSS and the PROCESS macro for mediation analysis. There was a positive relationship between nursing students' perceptions of using the assessment tool AssCE and their overall perception of the clinical learning environment. This relationship was, in turn, mediated by the content discussed during the formative mid-course discussion and summative final assessment. Our conclusion is that the assessment tool AssCE supported students' clinical learning and that this relationship, in turn, was mediated by the degree to which the conversation during the assessment meeting focused on the student's knowledge, skills and professional judgement. Copyright © 2017 Elsevier Ltd. All rights reserved.

Photoeffect cross sections of some rare-earth elements at 145.4 keV

NASA Astrophysics Data System (ADS)

Umesh, T. K.; Ranganathaiah, C.; Sanjeevaiah, B.

1985-08-01

Total attenuation cross sections in the elements La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, and Er were derived from the measured total cross sections of their simple oxide compounds, by employing the mixture rule at 145.4-keV photon energy. The compound cross sections have been measured by performing transmission experiments in a good geometry setup. From the derived total cross sections of elements, photoeffect cross sections have been obtained by subtracting the theoretical scattering cross sections. A good agreement is observed between the present data of photoeffect cross sections and Scofield's theoretical data.

miRNA-mediated 'tug-of-war' model reveals ceRNA propensity of genes in cancers.

PubMed

Swain, Arpit Chandan; Mallick, Bibekanand

2018-06-01

Competing endogenous RNA (ceRNA) are transcripts that cross-regulate each other at the post-transcriptional level by competing for shared microRNA response elements (MREs). These have been implicated in various biological processes impacting cell-fate decisions and diseases including cancer. There are several studies that predict possible ceRNA pairs by adopting various machine-learning and mathematical approaches; however, there is no method that enables us to gauge as well as compare the propensity of the ceRNA of a gene and precisely envisages which among a pair exerts a stronger pull on the shared miRNA pool. In this study, we developed a method that uses the 'tug of war of genes' concept to predict and quantify ceRNA potential of a gene for the shared miRNA pool in cancers based on a score represented by SoCeR (score of competing endogenous RNA). The method was executed on the RNA-Seq transcriptional profiles of genes and miRNA available at TCGA along with CLIP-supported miRNA-target sites to predict ceRNA in 32 cancer types which were validated with already reported cases. The proposed method can be used to determine the sequestering capability of the gene of interest as well as in ranking the probable ceRNA candidates of a gene. Finally, we developed standalone applications (SoCeR tool) to aid researchers in easier implementation of the method in analysing different data sets or diseases. © 2018 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.

Properties of transparent (Gd,Lu)3(Al,Ga)5O12:Ce ceramic with Mg, Ca and Ce co-dopants

NASA Astrophysics Data System (ADS)

Wang, Yimin; Baldoni, Gary; Brecher, Charles; Rhodes, William H.; Shirwadkar, Urmila; Glodo, Jarek; Shah, Ishaan; Ji, Chuncheng

2015-08-01

Cerium activated mixed lutetium/gadolinium- and aluminum/gallium-based garnets have great potential as host scintillators for medical imaging applications. (Gd,Lu)3(Al,Ga)5O12:Ce and denoted as GLuGAG feature high effective atomic number and good light yield, which make it particularly attractive for Positron Emission Tomography (PET) and other γ-ray detection applications. For PET application, rapid decay and good timing resolution are extremely important. Most Ce-doped mixed garnet materials such as GLuGAG:Ce, have their main decay component at around 80 ns. However, it has been reported that the decays of some single crystal scintillators (e.g., LSO and GGAG) can be effectively accelerated by codoping with selected additives such as Ca, Mg and B. In this study, transparent polycrystalline (Gd,Lu)3(Al,Ga)5O12:Ce ceramics codoped with Ca or Mg or additional Ce, were fabricated by the sinter-HIP approach. It was found the transmission of the ceramics are closely related to the microstructure of the ceramics. As the co-dopant levels increase, 2nd phase occurs in the ceramic and thus transparency of the ceramic decreases. Ca and Mg co-doping in GLuGAG:Ce ceramic effectively accelerate decays of GLuGAG:Ce ceramics at a cost of light output. However, additional Ce doping in the GLuGAG:Ce has no benefit on improving decay time but, on the other hand, reduces transmission, light output. The mechanism under the different scintillation behaviors with Mg, Ca and Ce dopants are discussed. The results suggest that decay time of GLuGAG:Ce ceramics can be effectively tailored by co-doping GLuGAG:Ce ceramic with Mg and Ca for applications with optimal timing resolution.

Divergence of compost extract and bio-organic manure effects on lucerne plant and soil

PubMed Central

Hu, Jian; Hu, Yifei; Yang, Gaowen; Zhang, Yingjun

2017-01-01

Aim Application of organic materials into agricultural systems enhances plant growth and yields, and improves soil fertility and structure. This study aimed to examine the effects of “compost extract (CE)”, a soil conditioner, and bio-organic manure (BOM) on the growth of lucerne (Medicago sativa), and compare the efficiency between BOM (including numbers of microorganisms) and CE (including no added microorganisms). Method A greenhouse experiment was conducted with four soil amendment treatments (control, BOM, CE and CEBOM), and was arranged in a completely randomized design with 10 replicates for each treatment. Plant biomass, nutritive value and rhizobia efficacy as well as soil characteristics were monitored. Result CE rather than BOM application showed a positive effect on plant growth and soil properties when compared with the control. Lucerne nodulation responded equally to CE addition and rhizobium inoculation. CE alone and in combination with BOM significantly increased plant growth and soil microbial activities and improved soil structure. The synergistic effects of CE and BOM indicate that applying CE and BOM together could increase their efficiency, leading to higher economic returns and improved soil health. However, CE alone is more effective for legume growth since nodulation was suppressed by nitrogen input from BOM. CE had a higher efficiency than BOM for enriching soil indigenous microorganisms instead of adding microorganisms and favouring plant nodulation. PMID:28894647

[Evaluation of continuous education: from the satisfaction to the impact. With regard to a formative programme in minor surgery in a health area].

PubMed

Martín Fernández, J; Martínez Marcos, M; Ferrándiz Santos, J

2001-04-30

To compare the evaluation of reaction of an activity of continuous education (CE) in minor surgery (MS), with the impact in the realization of MS in a health area. Observational cross-sectional study. Setting. 27 centers in a health area that offer MS between their services. The valuation was studied in a scale from 1 to 10, of 9 theoretical-practical activities of CE in MS and the consideration of its utility. The number of activities of MS (NMS) carried out in all the units, was picked up during one year, and a model of lineal regression was built. The independent variable was the NMS, and the explanatory ones the assistance pressure (AP), the postgraduate formation (PF), the staff of the unit, the equipment (E), and the carried out CE. The valuation of the CE had a median of 8 (with interquartile range 1), 85.1% of the people who realized CE in MS said that this would be of utility. However in the explanatory regression model the PF was the only significant variable (beta = 6.7; 95% CI, 0.12-12.22). Neither the CE, nor the AP, nor the E, explained the variability among the NMS. The CE in MS with conventional methodology has a very positive reaction evaluation, but its impact in the later realization of MS is not significant.

Cinnamon extract regulates glucose transporter and insulin-signaling gene expression in mouse adipocytes.

PubMed

Cao, Heping; Graves, Donald J; Anderson, Richard A

2010-11-01

Cinnamon extracts (CE) are reported to have beneficial effects on people with normal and impaired glucose tolerance, the metabolic syndrome, type 2 diabetes, and insulin resistance. However, clinical results are controversial. Molecular characterization of CE effects is limited. This study investigated the effects of CE on gene expression in cultured mouse adipocytes. Water-soluble CE was prepared from ground cinnamon (Cinnamomum burmannii). Quantitative real-time PCR was used to investigate CE effects on the expression of genes coding for adipokines, glucose transporter (GLUT) family, and insulin-signaling components in mouse 3T3-L1 adipocytes. CE (100 μg/ml) increased GLUT1 mRNA levels 1.91±0.15, 4.39±0.78, and 6.98±2.18-fold of the control after 2-, 4-, and 16-h treatments, respectively. CE decreased the expression of further genes encoding insulin-signaling pathway proteins including GSK3B, IGF1R, IGF2R, and PIK3R1. This study indicates that CE regulates the expression of multiple genes in adipocytes and this regulation could contribute to the potential health benefits of CE. Published by Elsevier GmbH.

Fermi-surface topology of the heavy-fermion system Ce2PtIn8

NASA Astrophysics Data System (ADS)

Klotz, J.; Götze, K.; Green, E. L.; Demuer, A.; Shishido, H.; Ishida, T.; Harima, H.; Wosnitza, J.; Sheikin, I.

2018-04-01

Ce2PtIn8 is a recently discovered heavy-fermion system structurally related to the well-studied superconductor CeCoIn5. Here we report on low-temperature de Haas-van Alphen-effect measurements in high magnetic fields in Ce2PtIn8 and Pr2PtIn8 . In addition, we performed band-structure calculations for localized and itinerant Ce-4 f electrons in Ce2PtIn8 . Comparison with the experimental data of Ce2PtIn8 and of the 4 f -localized Pr2PtIn8 suggests the itinerant character of the Ce-4 f electrons. This conclusion is further supported by the observation of effective masses in Ce2PtIn8 , which are strongly enhanced with up to 26 bare electron masses.

Role of the long non-coding RNA PVT1 in the dysregulation of the ceRNA-ceRNA network in human breast cancer

PubMed Central

Conte, Federica; Fiscon, Giulia; Chiara, Matteo; Colombo, Teresa; Farina, Lorenzo

2017-01-01

Recent findings have identified competing endogenous RNAs (ceRNAs) as the drivers in many disease conditions, including cancers. The ceRNAs indirectly regulate each other by reducing the amount of microRNAs (miRNAs) available to target messenger RNAs (mRNAs). The ceRNA interactions mediated by miRNAs are modulated by a titration mechanism, i.e. large changes in the ceRNA expression levels either overcome, or relieve, the miRNA repression on competing RNAs; similarly, a very large miRNA overexpression may abolish competition. The ceRNAs are also called miRNA “decoys” or miRNA “sponges” and encompass different RNAs competing with each other to attract miRNAs for interactions: mRNA, long non-coding RNAs (lncRNAs), pseudogenes, or circular RNAs. Recently, we developed a computational method for identifying ceRNA-ceRNA interactions in breast invasive carcinoma. We were interested in unveiling which lncRNAs could exert the ceRNA activity. We found a drastic rewiring in the cross-talks between ceRNAs from the physiological to the pathological condition. The main actor of this dysregulated lncRNA-associated ceRNA network was the lncRNA PVT1, which revealed a net biding preference towards the miR-200 family members in normal breast tissues. Despite its up-regulation in breast cancer tissues, mimicked by the miR-200 family members, PVT1 stops working as ceRNA in the cancerous state. The specific conditions required for a ceRNA landscape to occur are still far from being determined. Here, we emphasized the importance of the relative concentration of the ceRNAs, and their related miRNAs. In particular, we focused on the withdrawal in breast cancer tissues of the PVT1 ceRNA activity and performed a gene expression and sequence analysis of its multiple isoforms. We found that the PVT1 isoform harbouring the binding site for a representative miRNA of the miR-200 family shows a drastic decrease in its relative concentration with respect to the miRNA abundance in breast cancer tissues, providing a plausibility argument to the breakdown of the sponge program orchestrated by the oncogene PVT1. PMID:28187158

Flexibility and torsional behaviour of rotary nickel-titanium PathFile, RaCe ISO 10, Scout RaCe and stainless steel K-File hand instruments.

PubMed

Nakagawa, R K L; Alves, J L; Buono, V T L; Bahia, M G A

2014-03-01

To assess and compare the flexibility and torsional resistance of PathFile, RaCe ISO 10 and Scout RaCe instruments in relation to stainless steel K-File hand instruments. Rotary PathFile (sizes 13, 16 and 19; .02 taper), Race ISO 10 (size 10; 0.02, 0.04 and 0.06 tapers), Scout RaCe (sizes 10, 15 and 20; 0.02 taper) and hand K-File (sizes 10, 15 and 20; 0.02 taper) instruments were evaluated. Alloy chemical composition, phases present and transformation temperatures were determined for the NiTi instruments. For all instruments, diameters at each millimetre from the tip as well as cross-sectional areas at 3 mm from the tip were measured based on ANSI/ADA Specification No. 101 using image analysis software. Resistance to bending and torsional resistance were determined according to specification ISO 3630-1. Vickers microhardness measurements were also taken in all instruments to assess their strength. Data were analysed using analysis of variance (α = 0.05). The alloys used in the manufacture of the three types of NiTi instruments had approximately the same chemical composition, but the PathFile instruments had a higher Af transformation temperature and contained a small amount of B19' martensite. All instruments had diameter values within the standard tolerance. The bending and torsional resistance values were significantly increased relative to the instrument diameter and cross-sectional area. PathFile instruments were the most flexible and the least torque resistant, whilst the stainless steel instruments were the least flexible although they were more torque resistant than the NiTi instruments. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Photodynamic inactivation of bacteria using polyethylenimine-chlorin(e6) conjugates: Effect of polymer molecular weight, substitution ratio of chlorin(e6) and pH.

PubMed

Huang, Liyi; Zhiyentayev, Timur; Xuan, Yi; Azhibek, Dulat; Kharkwal, Gitika B; Hamblin, Michael R

2011-04-01

Antimicrobial photodynamic therapy (APDT) is a novel technique to treat local infections. Previously we reported that the attachment of chlorin(e6) to polyethylenimine (PEI) polymers to form PEI-ce6 conjugates is an effective way to improve ce6 PDT activity against bacteria. The aim of this work was to explore how the polymer molecular weight, substitution ratio (SR) of ce6 and pH value affect the PDT efficacy. We have synthesized PEI-ce6(10) (MW = 60,000, SR = 1) and PEI-ce6(11) (MW = 60,000, SR = 5) and compared these with the previous PEI-ce6(9) (MW = 10,000, SR = 1). We tested the PDT efficacy of these three conjugates against Gram-negative E. coli and Gram-positive bacteria (S. aureus and E. fecalis) at three different pH values (5.0, 7.4, 10.0) that may affect the charge on both the bacterial cells and on the conjugate (that has both basic and acidic groups). PEI-ce6(9) and PEI-ce6(10) were the most effective against these tested bacteria. The PDT effect of all three conjugates depended on pH values. The effective order was pH = 10.0 > pH = 7.4 > pH = 5.0 on E. coli. For S. aureus and E. fecalis the order was pH = 5.0 > pH = 10.0 > pH = 7.4. PEI-ce6(11) PDT activity was worse than PEI-ce6(10) activity which is probably connected to the fact that ce6 molecules are self-quenched within the PEI-ce6(11) molecule. Ce6 quenching within the PEI-ce6 molecules was proved by analyzing fluorescence spectra of PEI-ce6 conjugates at different pH values. There were no differences in bacterial uptake between different pH values in three PEI-ce6 conjugates. We assume high pH (rather than low pH as was hypothesized) disaggregates the conjugates, so the higher pH was more effective than the lower pH against E. coli. But for Gram-positive bacteria, low pH was more effective possibly due to more overall positive charge on the conjugate. Copyright © 2011 Wiley-Liss, Inc.

Examining the cost-effectiveness of cancer screening promotion.

PubMed

Andersen, M Robyn; Urban, Nicole; Ramsey, Scott; Briss, Peter A

2004-09-01

Cost-effectiveness analyses (CEAs) can help to quantify the contribution of the promotion of a screening program to increased participation in screening. The cost-effectiveness (C/E) of screening promotion depends in large part on the endpoints of interest. At the most fundamental level, the C/E of a strategy for promoting screening would focus on the attendance rate, or cost per person screened, and the C/E would be influenced by the costs of promotion, as well as by the size and responsiveness of the target population. In addition, the costs of screening promotion (measured as the cost per additional participant in screening) can be included in a CEA estimate of the screening technology. In this case, depending on the efficacy of the screening test and the costs and influence of the promotion, the C/E of screening may improve or become poorer. In the current study, the authors reviewed the literature on the C/E of cancer screening promotion. The following lessons were learned regarding the C/E of screening and its promotion: 1) high-quality information on the C/E of screening is increasingly available; 2) cost-effective promotion of screening is dependent on cost-effective screening strategies; 3) quality-of-life effects may be important in assessing the overall C/E of screening programs; 4) research efforts aimed at identifying cost-effective approaches to screening promotion are useful but sparse; 5) C/E studies should be better incorporated into well designed effectiveness research efforts; 6) variations in C/E according to intervention characteristics, population characteristics, and context should be evaluated in greater depth; 7) the long-term effects of screening promotion are critical to assessing C/E; 8) the effects of promotion on costs of screening must be better understood; and 9) CEA must be interpreted in light of other information. The authors showed that CEA can be a valuable tool for understanding the merits of health promotion interventions and that CEA is particularly valuable in identifying screening strategies that might be promoted most cost-effectively.

Neuroprotective Effect of CeO2@PAA-LXW7 Against H2O2-Induced Cytotoxicity in NGF-Differentiated PC12 Cells.

PubMed

Jia, Jingjing; Zhang, Ting; Chi, Jieshan; Liu, Xiaoma; Sun, Jingjing; Xie, Qizhi; Peng, Sijia; Li, Changyan; Yi, Li

2018-06-07

CeO 2 nanoparticles (nanoceria) have been used in many studies as a powerful free radical scavenger, and LXW7, a small-molecule peptide, can specifically target the integrin αvβ3, whose neuroprotective effects have also been demonstrated. The objective of this study is to observe the neuroprotective effect and potential mechanism of CeO 2 @PAA-LXW7, a new compound that couples CeO 2 @PAA (nanoceria modified with the functional group of polyacrylic acid) with LXW7 via a series of chemical reactions, in H 2 O 2 -induced NGF-differentiated PC12 cells. We examined the effects of LXW7, CeO 2 @PAA, and CeO 2 @PAA-LXW7 on the viability of primary hippocampal neurons and found that there was no significant difference under control conditions, but increased cellular viability was observed in the case of H 2 O 2 -induced injury. We used H 2 O 2 -induced NGF-differentiated PC12 cells as the classical injury model to investigate the neuroprotective effect of CeO 2 @PAA-LXW7. In this study, LXW7, CeO 2 @PAA, and CeO 2 @PAA-LXW7 inhibit H 2 O 2 -induced oxidative stress by reducing the production of reactive oxygen species (ROS) and regulating Bax/Bcl-2, cleaved caspase-3 and mitochondrial cytochrome C (cyto C) in the apoptotic signaling pathways. We found that the levels of phosphorylation of focal adhesion kinase (FAK) and of signal transducer and activator of transcription 3 (STAT3) increased significantly in H 2 O 2 -induced NGF-differentiated PC12 cells, whereas LXW7, CeO 2 @PAA, and CeO 2 @PAA-LXW7 suppressed the increase to different degrees. Among the abovementioned changes, the inhibitory effect of CeO 2 @PAA-LXW7 on H 2 O 2 -induced changes, including the increases in the levels of p-FAK and p-STAT3, is more obvious than that of LXW7 or CeO 2 @PAA alone. In summary, these results suggest that integrin signaling participates in the regulation of apoptosis via the regulation of ROS and of the apoptosis pathway in H 2 O 2 -induced NGF-differentiated PC12 cells. LXW7, CeO 2 @PAA, and CeO 2 @PAA-LXW7 can play neuroprotective roles by counteracting the oxidative stress and apoptosis induced by H 2 O 2 in NGF-differentiated PC12 cells. CeO 2 @PAA-LXW7 exerting a more powerful synergistic effect via the conjunction of LXW7 and CeO 2 @PAA.

Assessing the Validity of Automated Webcrawlers as Data Collection Tools to Investigate Online Child Sexual Exploitation.

PubMed

Westlake, Bryce; Bouchard, Martin; Frank, Richard

2017-10-01

The distribution of child sexual exploitation (CE) material has been aided by the growth of the Internet. The graphic nature and prevalence of the material has made researching and combating difficult. Although used to study online CE distribution, automated data collection tools (e.g., webcrawlers) have yet to be shown effective at targeting only relevant data. Using CE-related image and keyword criteria, we compare networks starting from CE websites to those from similar non-CE sexuality websites and dissimilar sports websites. Our results provide evidence that (a) webcrawlers have the potential to provide valid CE data, if the appropriate criterion is selected; (b) CE distribution is still heavily image-based suggesting images as an effective criterion; (c) CE-seeded networks are more hub-based and differ from non-CE-seeded networks on several website characteristics. Recommendations for improvements to reliable criteria selection are discussed.

Stress response and tolerance of Zea mays to CeO2 nanoparticles: cross talk among H2O2, heat shock protein, and lipid peroxidation.

PubMed

Zhao, Lijuan; Peng, Bo; Hernandez-Viezcas, Jose A; Rico, Cyren; Sun, Youping; Peralta-Videa, Jose R; Tang, Xiaolei; Niu, Genhua; Jin, Lixin; Varela-Ramirez, Armando; Zhang, Jian-ying; Gardea-Torresdey, Jorge L

2012-11-27

The rapid development of nanotechnology will inevitably release nanoparticles (NPs) into the environment with unidentified consequences. In addition, the potential toxicity of CeO(2) NPs to plants and the possible transfer into the food chain are still unknown. Corn plants (Zea mays) were germinated and grown in soil treated with CeO(2) NPs at 400 or 800 mg/kg. Stress-related parameters, such as H(2)O(2), catalase (CAT), and ascorbate peroxidase (APX) activity, heat shock protein 70 (HSP70), lipid peroxidation, cell death, and leaf gas exchange were analyzed at 10, 15, and 20 days post-germination. Confocal laser scanning microscopy was used to image H(2)O(2) distribution in corn leaves. Results showed that the CeO(2) NP treatments increased accumulation of H(2)O(2), up to day 15, in phloem, xylem, bundle sheath cells and epidermal cells of shoots. The CAT and APX activities were also increased in the corn shoot, concomitant with the H(2)O(2) levels. Both 400 and 800 mg/kg CeO(2) NPs triggered the up-regulation of the HSP70 in roots, indicating a systemic stress response. None of the CeO(2) NPs increased the level of thiobarbituric acid reacting substances, indicating that no lipid peroxidation occurred. CeO(2) NPs, at both concentrations, did not induce ion leakage in either roots or shoots, suggesting that membrane integrity was not compromised. Leaf net photosynthetic rate, transpiration, and stomatal conductance were not affected by CeO(2) NPs. Our results suggest that the CAT, APX, and HSP70 might help the plants defend against CeO(2) NP-induced oxidative injury and survive NP exposure.

Stress Response and Tolerance of Zea mays to CeO2 Nanoparticles: Cross Talk among H2O2, Heat Shock Protein and Lipid Peroxidation

PubMed Central

Zhao, Lijuan; Peng, Bo; Hernandez-Viezcas, Jose A.; Rico, Cyren; Sun, Youping; Peralta-Videa, Jose R.; Tang, Xiaolei; Niu, Genhua; Jin, Lixin; Varela-Ramirez, Armando; Zhang, Jian-ying; Gardea-Torresdey, Jorge L.

2014-01-01

The rapid development of nanotechnology will inevitably release nanoparticles (NPs) into the environment with unidentified consequences. In addition, the potential toxicity of CeO2 NPs to plants, and the possible transfer into the food chain, are still unknown. Corn plants (Zea mays) were germinated and grown in soil treated with CeO2 NPs at 400 or 800 mg/kg. Stress related parameters, such as: H2O2, catalase (CAT) and ascorbate peroxidase (APX) activity, heat shock protein 70 (HSP 70), lipid peroxidation, cell death and leaf gas exchange were analyzed at 10, 15, and 20 days post germination. Confocal laser scanning microscopy was used to image H2O2 distribution in corn leaves. Results showed that the CeO2 NP treatments increased accumulation of H2O2, up to day 15, in phloem, xylem, bundle sheath cells, and epidermal cells of shoots. The CAT and APX activities were also increased in the corn shoot, concomitant with the H2O2 levels. Both 400 and 800 mg/kg CeO2 NPs triggered the up regulation of the HSP 70 in roots, indicating a systemic stress response. None of the CeO2 NPs increased the level of thiobarbituric acid reacting substances, indicating that no lipid peroxidation occurred. CeO2 NPs, at both concentrations, did not induce ion leakage in either roots or shoots, suggesting membrane integrity was not compromised. Leaf net photosynthetic rate, transpiration, and stomatal conductance were not affected by CeO2 NPs. Our results suggest that the CAT, APX and HSP 70 might help the plants defend against CeO2 NPs induced oxidative injury and survive NP exposure. PMID:23050848

Electronic structure of heavy fermion system CePt 2In 7 from angle-resolved photoemission spectroscopy

DOE PAGES

Shen, Bing; Yu, Li; Liu, Kai; ...

2017-06-01

We have carried out high-resolution angle-resolved photoemission measurements on the Cebased heavy fermion compound CePt 2In 7 that exhibits stronger two-dimensional character than the prototypical heavy fermion system CeCoIn 5. Multiple Fermi surface sheets and a complex band structure are clearly resolved. We have also performed detailed band structure calculations on CePt 2In 7. The good agreement found between our measurements and the calculations suggests that the band renormalization effect is rather weak in CePt 2In 7. A comparison of the common features of the electronic structure of CePt 2In 7 and CeCoIn5 indicates that CeCoIn 5 shows a muchmore » stronger band renormalization effect than CePt 2In 7. These results provide new information for understanding the heavy fermion behaviors and unconventional superconductivity in Ce-based heavy fermion systems.« less

Exposure of agricultural crops to nanoparticle CeO2 in biochar-amended soil.

PubMed

Servin, Alia D; De la Torre-Roche, Roberto; Castillo-Michel, Hiram; Pagano, Luca; Hawthorne, Joseph; Musante, Craig; Pignatello, Joseph; Uchimiya, Minori; White, Jason C

2017-01-01

Biochar is seeing increased usage as an amendment in agricultural soils but the significance of nanoscale interactions between this additive and engineered nanoparticles (ENP) remains unknown. Corn, lettuce, soybean and zucchini were grown for 28 d in two different soils (agricultural, residential) amended with 0-2000 mg engineered nanoparticle (ENP) CeO 2  kg -1 and biochar (350 °C or 600 °C) at application rates of 0-5% (w/w). At harvest, plants were analyzed for biomass, Ce content, chlorophyll and lipid peroxidation. Biomass from the four species grown in residential soil varied with species and biochar type. However, biomass in the agricultural soil amended with biochar 600 °C was largely unaffected. Biochar co-exposure had minimal impact on Ce accumulation, with reduced or increased Ce content occurring at the highest (5%) biochar level. Soil-specific and biochar-specific effects on Ce accumulation were observed in the four species. For example, zucchini grown in agricultural soil with 2000 mg CeO 2  kg -1 and 350 °C biochar (0.5-5%) accumulated greater Ce than the control. However, for the 600 °C biochar, the opposite effect was evident, with decreased Ce content as biochar increased. A principal component analysis showed that biochar type accounted for 56-99% of the variance in chlorophyll and lipid peroxidation across the plants. SEM and μ-XRF showed Ce association with specific biochar and soil components, while μ-XANES analysis confirmed that after 28 d in soil, the Ce remained largely as CeO 2 . The current study demonstrates that biochar synthesis conditions significantly impact interactions with ENP, with subsequent effects on particle fate and effects. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Opposing effects of dopamine antagonism in a motor sequence task—tiapride increases cortical excitability and impairs motor learning

PubMed Central

Lissek, Silke; Vallana, Guido S.; Schlaffke, Lara; Lenz, Melanie; Dinse, Hubert R.; Tegenthoff, Martin

2014-01-01

The dopaminergic system is involved in learning and participates in the modulation of cortical excitability (CE). CE has been suggested as a marker of learning and use-dependent plasticity. However, results from separate studies on either motor CE or motor learning challenge this notion, suggesting opposing effects of dopaminergic modulation upon these parameters: while agonists decrease and antagonists increase CE, motor learning is enhanced by agonists and disturbed by antagonists. To examine whether this discrepancy persists when complex motor learning and motor CE are measured in the same experimental setup, we investigated the effects of dopaminergic (DA) antagonism upon both parameters and upon task-associated brain activation. Our results demonstrate that DA-antagonism has opposing effects upon motor CE and motor sequence learning. Tiapride did not alter baseline CE, but increased CE post training of a complex motor sequence while simultaneously impairing motor learning. Moreover, tiapride reduced activation in several brain regions associated with motor sequence performance, i.e., dorsolateral PFC (dlPFC), supplementary motor area (SMA), Broca's area, cingulate and caudate body. Blood-oxygenation-level-dependent (BOLD) intensity in anterior cingulate and caudate body, but not CE, correlated with performance across groups. In summary, our results do not support a concept of CE as a general marker of motor learning, since they demonstrate that a straightforward relation of increased CE and higher learning success does not apply to all instances of motor learning. At least for complex motor tasks that recruit a network of brain regions outside motor cortex, CE in primary motor cortex is probably no central determinant for learning success. PMID:24994972

Neonate Auditory Brainstem Responses to CE-Chirp and CE-Chirp Octave Band Stimuli II: Versus Adult Auditory Brainstem Responses.

PubMed

Cobb, Kensi M; Stuart, Andrew

The purpose of the study was to examine the differences in auditory brainstem response (ABR) latency and amplitude indices to the CE-Chirp stimuli in neonates versus young adults as a function of stimulus level, rate, polarity, frequency and gender. Participants were 168 healthy neonates and 20 normal-hearing young adults. ABRs were obtained to air- and bone-conducted CE-Chirps and air-conducted CE-Chirp octave band stimuli. The effects of stimulus level, rate, and polarity were examined with air-conducted CE-Chirps. The effect of stimulus level was also examined with bone-conducted CE-Chirps and CE-Chirp octave band stimuli. The effect of gender was examined across all stimulus manipulations. In general, ABR wave V amplitudes were significantly larger (p < 0.0001) and latencies were significantly shorter (p < 0.0001) for adults versus neonates for all air-conducted CE-Chirp stimuli with all stimulus manipulations. For bone-conducted CE-Chirps, infants had significantly shorter wave V latencies than adults at 15 dB nHL and 45 dB nHL (p = 0.02). Adult wave V amplitude was significantly larger for bone-conducted CE-Chirps only at 30 dB nHL (p = 0.02). The effect of gender was not statistically significant across all measures (p > 0.05). Significant differences in ABR latencies and amplitudes exist between newborns and young adults using CE-Chirp stimuli. These differences are consistent with differences to traditional click and tone burst stimuli and reflect maturational differences as a function of age. These findings continue to emphasize the importance of interpreting ABR results using age-based normative data.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Fei; Wan, Xiangang; Phelan, Daniel

ZrCuSi 2-type CePd 1-xBi 2 crystals were obtained from excess Bi flux. Magnetic susceptibility measurements reveal that CePd 1-xBi 2 is a highly anisotropic antiferromagnet with transition temperature at 6 K, and a magnetic-field-induced metamagnetic transition at 5 T. An enhanced Sommerfeld coefficient of γ of 0.199 J-mol-Ce -1K -2 obtained from specific heat measurements suggests a moderate Kondo effect in CePd 1-xBi 2. In addition to the antiferromagnetic peak the resistivity curve shows a shoulder-like behavior which could be attributed to the presence of Kondo effect and crystal-electric-field effects in this compound. Magnetoresistance and Hall effect measurements suggest anmore » interplay between Kondo and crystal-electric-field effects which reconstructs the Fermi surface topology of CePd 1-xBi 2 around 75 K. Electronic structure calculations reveal the Pd vacancies are important to the magnetic structure and enhance the crystal-electric-field effects which quench the orbital moment of Ce at low temperatures.« less

DYNAMICS AND STAGNATION IN THE MALTHUSIAN EPOCH

PubMed Central

Ashraf, Quamrul; Galor, Oded

2013-01-01

This paper examines the central hypothesis of the influential Malthusian theory, according to which improvements in the technological environment during the pre-industrial era had generated only temporary gains in income per capita, eventually leading to a larger, but not significantly richer, population. Exploiting exogenous sources of cross-country variations in land productivity and the level of technological advancement the analysis demonstrates that, in accordance with the theory, technological superiority and higher land productivity had significant positive effects on population density but insignificant effects on the standard of living, during the time period 1–1500 CE. PMID:25506082

Antiferromagnetic Kondo lattice in the layered compound CePd 1 - x Bi 2 and comparison to the superconductor LaPd 1 - x Bi 2

DOE PAGES

Han, Fei; Wan, Xiangang; Phelan, Daniel; ...

2015-07-13

ZrCuSi 2-type CePd 1-xBi 2 crystals were obtained from excess Bi flux. Magnetic susceptibility measurements reveal that CePd 1-xBi 2 is a highly anisotropic antiferromagnet with transition temperature at 6 K, and a magnetic-field-induced metamagnetic transition at 5 T. An enhanced Sommerfeld coefficient of γ of 0.199 J-mol-Ce -1K -2 obtained from specific heat measurements suggests a moderate Kondo effect in CePd 1-xBi 2. In addition to the antiferromagnetic peak the resistivity curve shows a shoulder-like behavior which could be attributed to the presence of Kondo effect and crystal-electric-field effects in this compound. Magnetoresistance and Hall effect measurements suggest anmore » interplay between Kondo and crystal-electric-field effects which reconstructs the Fermi surface topology of CePd 1-xBi 2 around 75 K. Electronic structure calculations reveal the Pd vacancies are important to the magnetic structure and enhance the crystal-electric-field effects which quench the orbital moment of Ce at low temperatures.« less

Hall effect in Ce/sub 1-x/Y/sub x/Pd/sub 3/ mixed-valence alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fert, A.; Pureur, P.; Hamzic, A.

Mixed-valence and Kondo lattice systems exhibit large anomalous Hall coefficients with a striking change of sign at low temperature in several systems (CePd/sub 3/, CeCu/sub 6/,..., etc.). We have studied the Hall effect of Ce/sub 1-x/Y/sub x/Pd/sub 3/, in which the substitution of small amounts of Y for Ce prevents the development of coherence at low temperature. We find that the Hall coefficient does not change its sign at low temperature and can be well understood in the one-impurity model of Ramakrishnan, Coleman, and Anderson. We infer that the change of sign observed in CePd/sub 3/ is an effect ofmore » coherence.« less

Neonate Auditory Brainstem Responses to CE-Chirp and CE-Chirp Octave Band Stimuli I: Versus Click and Tone Burst Stimuli.

PubMed

Cobb, Kensi M; Stuart, Andrew

The purpose of the study was to generate normative auditory brainstem response (ABR) wave component peak latency and amplitude values for neonates with air- and bone-conducted CE-Chirps and air-conducted CE-Chirp octave band stimuli (i.e., 500, 1000, 2000, and 4000 Hz). A second objective was to compare neonate ABRs to CE-Chirp stimuli with ABR responses to traditional click and tone burst stimuli with the same stimulus parameters. Participants were 168 healthy neonates. ABRs were obtained to air- and bone-conducted CE-Chirp and click stimuli and air-conducted CE-Chirp octave band and tone burst stimuli. The effects of stimulus level, rate, and polarity were examined with air-conducted CE-Chirps and clicks. The effect of stimulus level was also examined with bone-conducted CE-Chirps and clicks and air-conducted CE-Chirp octave band stimuli. In general, ABR wave V amplitudes to air- and bone-conducted CE-Chirp stimuli were significantly larger (p < 0.05) than those evoked to traditional click and tone burst stimuli. Systematic statistically significant (p < 0.05) wave V latency differences existed between the air- and bone-conducted CE-Chirp and CE-Chirp octave band stimuli relative to traditional click and tone burst stimuli. ABRs to air- and bone-conducted CE-Chirps and CE-Chirp octave band stimuli may be valuable in the assessment of newborn infants. However, the prognostic value of such stimuli needs to be validated.

Co-doping effects on luminescence and scintillation properties of Ce doped (Lu,Gd)3(Ga,Al)5O12 scintillator

NASA Astrophysics Data System (ADS)

Yamaguchi, Hiroaki; Kamada, Kei; Kurosawa, Shunsuke; Pejchal, Jan; Shoji, Yasuhiro; Yokota, Yuui; Ohashi, Yuji; Yoshikawa, Akira

2016-11-01

Mg co-doping effects on scintillation properties of Ce:Lu1Gd2(Ga,Al)5O12 (LGGAG) were investigated. Mg 200 ppm co-doped Ce:LGGAG single crystals were prepared by micro pulling down method. Absorption and luminescence spectra were measured together with several other scintillation characteristics, namely the scintillation decay and light yield to reveal the effect of Mg co-doping. Ce4+ charge transfer absorption was observed below 300 nm in Mg,Ce:LGGAG which is in good agreement with previous reports. The scintillation decay times were accelerated by Mg co-doping.

The Use of Prescription Drugs, Recreational Drugs, and “Soft Enhancers” for Cognitive Enhancement among Swiss Secondary School Students

PubMed Central

Liakoni, Evangelia; Schaub, Michael P.; Maier, Larissa J.; Glauser, Gaëlle-Vanessa; Liechti, Matthias E.

2015-01-01

The use of prescription or recreational drugs for cognitive enhancement (CE) is prevalent among students. However, the prevalence of CE among Swiss school students is unknown. We therefore performed a cross-sectional online survey including ≥ 16-year-old students from bridge-year schools (10th grade), vocational schools, and upper secondary schools (10th-12th grade) in the Canton of Zurich to investigate the prevalence of and motives for the use of prescription drugs, recreational drugs, and/or freely available soft enhancers for CE. A total of 1,139 students were included. Of these, 54.5% reported the use of prescription drugs (9.2%), recreational drugs including alcohol (6.2%), or soft enhancers (51.3%) explicitly for CE at least once in their lives. The last-year and last-month prevalence for CE considering all substances was 45.5% and 39.5%, respectively. Soft enhancers were the substances that were most commonly used (ever, last-year, and last-month, respectively), including energy drinks (33.3%, 28.4%, and 24.6%), coffee (29.8%, 25.1%, and 21.9%), and tobacco (12.6%, 9.3%, and 8.3%). CE with methylphenidate was less prevalent (4.0%, 2.8%, and 2.0%). However, the use of prescription drugs, alcohol, or illegal drugs for CE was reported by 13.3% of the participants. The most common motives for use were to stay awake and improve concentration. CE was more prevalent among students who reported higher levels of stress or performance pressure and students with psychiatric disorders. In conclusion, half of the school students had used a substance at least once in their lives to improve school performance. Soft enhancers were most commonly used. Prevalence rates were similar to those reported by Swiss university students, indicating that the use of prescription or recreational drugs for CE already occurs before starting higher education. Performance pressure, stress, and psychiatric disorders may be associated with CE. PMID:26505633

Preclinical Assessment of CD171-Directed CAR T-cell Adoptive Therapy for Childhood Neuroblastoma: CE7 Epitope Target Safety and Product Manufacturing Feasibility.

PubMed

Künkele, Annette; Taraseviciute, Agne; Finn, Laura S; Johnson, Adam J; Berger, Carolina; Finney, Olivia; Chang, Cindy A; Rolczynski, Lisa S; Brown, Christopher; Mgebroff, Stephanie; Berger, Michael; Park, Julie R; Jensen, Michael C

2017-01-15

The identification and vetting of cell surface tumor-restricted epitopes for chimeric antigen receptor (CAR)-redirected T-cell immunotherapy is the subject of intensive investigation. We have focused on CD171 (L1-CAM), an abundant cell surface molecule on neuroblastomas and, specifically, on the glycosylation-dependent tumor-specific epitope recognized by the CE7 monoclonal antibody. CD171 expression was assessed by IHC using CE7 mAb in tumor microarrays of primary, metastatic, and recurrent neuroblastoma, as well as human and rhesus macaque tissue arrays. The safety of targeting the CE7 epitope of CD171 with CE7-CAR T cells was evaluated in a preclinical rhesus macaque trial on the basis of CD171 homology and CE7 cross reactivity. The feasibility of generating bioactive CAR T cells from heavily pretreated pediatric patients with recurrent/refractory disease was assessed. CD171 is uniformly and abundantly expressed by neuroblastoma tumor specimens obtained at diagnoses and relapse independent of patient clinical risk group. CD171 expression in normal tissues is similar in humans and rhesus macaques. Infusion of up to 1 × 10 8 /kg CE7-CAR + CTLs in rhesus macaques revealed no signs of specific on-target off-tumor toxicity. Manufacturing of lentivirally transduced CD4 + and CD8 + CE7-CAR T-cell products under GMP was successful in 4 out of 5 consecutively enrolled neuroblastoma patients in a phase I study. All four CE7-CAR T-cell products demonstrated in vitro and in vivo antitumor activity. Our preclinical assessment of the CE7 epitope on CD171 supports its utility and safety as a CAR T-cell target for neuroblastoma immunotherapy. Clin Cancer Res; 23(2); 466-77. ©2016 AACR. ©2016 American Association for Cancer Research.

The Use of Prescription Drugs, Recreational Drugs, and "Soft Enhancers" for Cognitive Enhancement among Swiss Secondary School Students.

PubMed

Liakoni, Evangelia; Schaub, Michael P; Maier, Larissa J; Glauser, Gaëlle-Vanessa; Liechti, Matthias E

2015-01-01

The use of prescription or recreational drugs for cognitive enhancement (CE) is prevalent among students. However, the prevalence of CE among Swiss school students is unknown. We therefore performed a cross-sectional online survey including ≥ 16-year-old students from bridge-year schools (10th grade), vocational schools, and upper secondary schools (10th-12th grade) in the Canton of Zurich to investigate the prevalence of and motives for the use of prescription drugs, recreational drugs, and/or freely available soft enhancers for CE. A total of 1,139 students were included. Of these, 54.5% reported the use of prescription drugs (9.2%), recreational drugs including alcohol (6.2%), or soft enhancers (51.3%) explicitly for CE at least once in their lives. The last-year and last-month prevalence for CE considering all substances was 45.5% and 39.5%, respectively. Soft enhancers were the substances that were most commonly used (ever, last-year, and last-month, respectively), including energy drinks (33.3%, 28.4%, and 24.6%), coffee (29.8%, 25.1%, and 21.9%), and tobacco (12.6%, 9.3%, and 8.3%). CE with methylphenidate was less prevalent (4.0%, 2.8%, and 2.0%). However, the use of prescription drugs, alcohol, or illegal drugs for CE was reported by 13.3% of the participants. The most common motives for use were to stay awake and improve concentration. CE was more prevalent among students who reported higher levels of stress or performance pressure and students with psychiatric disorders. In conclusion, half of the school students had used a substance at least once in their lives to improve school performance. Soft enhancers were most commonly used. Prevalence rates were similar to those reported by Swiss university students, indicating that the use of prescription or recreational drugs for CE already occurs before starting higher education. Performance pressure, stress, and psychiatric disorders may be associated with CE.

CE microchips: an opened gate to food analysis.

PubMed

Escarpa, Alberto; González, María Cristina; Crevillén, Agustín González; Blasco, Antonio Javier

2007-03-01

CE microchips are the first generation of micrototal analysis systems (-TAS) emerging in the miniaturization scene of food analysis. CE microchips for food analysis are fabricated in both glass and polymer materials, such as PDMS and poly(methyl methacrylate) (PMMA), and use simple layouts of simple and double T crosses. Nowadays, the detection route preferred is electrochemical in both, amperometry and conductivity modes, using end-channel and contactless configurations, respectively. Food applications using CE microchips are now emerging since food samples present complex matrices, the selectivity being a very important challenge because the total integration of analytical steps into microchip format is very difficult. As a consequence, the first contributions that have recently appeared in the relevant literature are based primarily on fast separations of analytes of high food significance. These protocols are combined with different strategies to achieve selectivity using a suitable nonextensive sample preparation and/or strategically choosing detection routes. Polyphenolic compounds, amino acids, preservatives, and organic and inorganic ions have been studied using CE microchips. Thus, new and exciting future expectations arise in the domain of food analysis. However, several drawbacks could easily be found and assumed within the miniaturization map.

Demonstration of spatial-light-modulation-based four-wave mixing in cold atoms

NASA Astrophysics Data System (ADS)

Juo, Jz-Yuan; Lin, Jia-Kang; Cheng, Chin-Yao; Liu, Zi-Yu; Yu, Ite A.; Chen, Yong-Fan

2018-05-01

Long-distance quantum optical communications usually require efficient wave-mixing processes to convert the wavelengths of single photons. Many quantum applications based on electromagnetically induced transparency (EIT) have been proposed and demonstrated at the single-photon level, such as quantum memories, all-optical transistors, and cross-phase modulations. However, EIT-based four-wave mixing (FWM) in a resonant double-Λ configuration has a maximum conversion efficiency (CE) of 25% because of absorptive loss due to spontaneous emission. An improved scheme using spatially modulated intensities of two control fields has been theoretically proposed to overcome this conversion limit. In this study, we first demonstrate wavelength conversion from 780 to 795 nm with a 43% CE by using this scheme at an optical density (OD) of 19 in cold 87Rb atoms. According to the theoretical model, the CE in the proposed scheme can further increase to 96% at an OD of 240 under ideal conditions, thereby attaining an identical CE to that of the previous nonresonant double-Λ scheme at half the OD. This spatial-light-modulation-based FWM scheme can achieve a near-unity CE, thus providing an easy method of implementing an efficient quantum wavelength converter for all-optical quantum information processing.

Lu.sub.1-xI.sub.3:Ce.sub.x--a scintillator for gamma ray spectroscopy and time-of-flight PET

DOEpatents

Shah, Kanai S.

2007-02-06

The present invention concerns very fast scintillator materials comprising lutetium iodide doped with Cerium (Lu.sub.1-xI.sub.3:Ce.sub.x; LuI.sub.3:Ce). The LuI.sub.3 scintillator material has surprisingly good characteristics including high light output, high gamma ray stopping efficiency, fast response, low cost, good proportionality, and minimal afterglow that the material is useful for gamma ray spectroscopy, medical imaging, nuclear and high energy physics research, diffraction, non-destructive testing, nuclear treaty verification and safeguards, and geological exploration. The timing resolution of the scintillators of the present invention provide compositions capable of resolving the position of an annihilation event within a portion of a human body cross-section.

Effects of local structure of Ce3+ ions on luminescent properties of Y3Al5O12:Ce nanoparticles

PubMed Central

He, Xiaowu; Liu, Xiaofang; Li, Rongfeng; Yang, Bai; Yu, Kaili; Zeng, Min; Yu, Ronghai

2016-01-01

Ce3+-doped yttrium aluminum garnet (YAG:Ce) nanocrystals were successfully synthesized via a facile sol-gel method. Multiple characterization techniques were employed to study the structure, morphology, composition and photoluminescence properties of YAG:Ce nanophosphors. The YAG:Ce0.0055 sintered at 1030 °C exhibited a typical 5d1-4f1 emission band with the maximum peak located at 525 nm, and owned a short fluorescence lifetime τ1 (~28 ns) and a long fluorescence lifetime τ2 (~94 ns). Calcination temperature and Ce3+ doping concentration have significant effects on the photoluminescence properties of the YAG:Ce nanophosphors. The emission intensity was enhanced as the calcination temperature increased from 830 to 1030 °C, but decreased dramatically with the increase of Ce3+ doping concentration from 0.55 to 5.50 at.% due to the concentration quenching. By optimizing the synthesized condition, the strongest photoluminescence emission intensity was achieved at 1030 °C with Ce3+ concentration of 0.55 at.%. PMID:26935980

Effect of Rare Earth Cerium Addition on Microstructures and Mechanical Properties of Low Carbon High Manganese Steels

NASA Astrophysics Data System (ADS)

Jiang, M. Z.; Yu, Y. C.; Li, H.; Ren, X.; Wang, S. B.

2017-02-01

Low carbon high manganese steels with different Ce contents were melted in medium frequency vacuum induction furnace. The microstructures and mechanical properties of steels were studied by OM, SEM, EDS and mechanical property testing. The results showed that the microstructures of experimental steels were refined remarkably, inclusions distributed more finely and uniformly, the tensile strength and impact toughness of tested steels both improved greatly after the addition of Ce. Thermodynamic calculation results demonstrated that Ce contained inclusions were Ce2O3 and Ce3S4, which agreed well with the results observed by SEM and EDS. By analysis of two-dimensional lattice disregistry, it was shown that the lattice misfit parameter between δ-Fe and Ce2O3, Ce3S4 are less than 6 %, which indicated that Ce2O3 and Ce3S4 could effectively act as the heterogeneous nuclei of initial δ-Fe. Therefore, the microstructures were refined significantly and the mechanical properties were improved correspondingly in Ce-added low carbon high manganese steels.

Protection against renal ischemia-reperfusion injury through hormesis? Dietary intervention versus cold exposure.

PubMed

Shushimita, Shushimita; Grefhorst, Aldo; Steenbergen, Jacobie; de Bruin, Ron W F; Ijzermans, Jan N M; Themmen, Axel P N; Dor, Frank J M F

2016-01-01

Dietary restriction (DR) and fasting (FA) induce robust protection against the detrimental effects of renal ischemia-reperfusion injury (I/RI). Several mechanisms of protection have been proposed, such as hormesis. Hormesis is defined as a life-supporting beneficial effect resulting from the cellular responses to single or multiple rounds of (mild) stress. The cold exposure (CE) model is a stress model similar to DR, and has been shown to have hormetic effects and has proved to increase longevity. CE is considered to be the most robust method to increase metabolism through activation of brown adipocytes. BAT has been considered important in etiology of obesity and its metabolic consequences. Since DR, FA, and CE models are proposed to work through hormesis, we investigated physiology of adipose tissue and effect on BAT in these models and compared them to ad libitum (AL) fed mice. We also studied the differential effect of these stress models on immunological changes, and effect of CE on renal I/RI. We show similar physiological changes in adiposity in male C57Bl/6 mice due to DR, FA and CE, but the CE mice were not protected against renal I/RI. The immunophenotypic changes observed in the CE mice were similar to the AL animals, in contrast to FA mice, that showed major immunophenotypic changes in the B and T cell development stages in primary and secondary lymphoid organs. Our findings thus demonstrate that DR, FA and CE are hormetic stress models. DR and FA protect against renal I/IR, whereas CE could not. Copyright © 2015 Elsevier Inc. All rights reserved.

Pygmy dipole resonance in 140Ce via inelastic scattering of 17O

NASA Astrophysics Data System (ADS)

Krzysiek, M.; Kmiecik, M.; Maj, A.; Bednarczyk, P.; Bracco, A.; Crespi, F. C. L.; Lanza, E. G.; Litvinova, E.; Paar, N.; Avigo, R.; Bazzacco, D.; Benzoni, G.; Birkenbach, B.; Blasi, N.; Bottoni, S.; Brambilla, S.; Camera, F.; Ceruti, S.; Ciemała, M.; de Angelis, G.; Désesquelles, P.; Eberth, J.; Farnea, E.; Gadea, A.; Giaz, A.; Görgen, A.; Gottardo, A.; Grebosz, J.; Hess, H.; Isocarte, R.; Jungclaus, A.; Leoni, S.; Ljungvall, J.; Lunardi, S.; Mazurek, K.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Milion, B.; Morales, A. I.; Napoli, D. R.; Nicolini, R.; Pellegri, L.; Pullia, A.; Quintana, B.; Recchia, F.; Reiter, P.; Rosso, D.; Salsac, M. D.; Siebeck, B.; Siem, S.; Söderström, P.-A.; Ur, C.; Valiente-Dobon, J. J.; Wieland, O.; Ziebliński, M.

2016-04-01

The γ decay from the high-lying states of 140Ce excited via inelastic scattering of 17O at a bombarding energy of 340 MeV was measured using the high-resolution AGATA-demonstrator array in coincidence with scattered ions detected in two segmented Δ E -E silicon detectors. Angular distributions of scattered ions and emitted γ rays were measured, as well as their differential cross sections. The excitation of 1- states below the neutron separation energy is similar to the one obtained in reactions with the α isoscalar probe. The comparison between the experimental differential cross sections and the corresponding predictions using the distorted-wave Born approximation allowed us to extract the isoscalar component of identified 1- pygmy states. For this analysis the form factor obtained by folding microscopically calculated transition densities and optical potentials was used.

Serological confirmatory testing of alveolar and cystic echinococcosis in clinical practice: results of a comparative study with commercialized and in-house assays.

PubMed

Reiter-Owona, Ingrid; Grüner, Beate; Frosch, Matthias; Hoerauf, Achim; Kern, Peter; Tappe, Dennis

2009-01-01

Sera of 50 patients with either cystic (CE) or alveolar echinococcosis (AE) in different clinical stages were examined for the presence of anti-Echinococcus-antibodies. Antibody-screening was performed with ELISA, IHA and IFAT, and confirmatory testing was done by the commercialized E. multilocularis-specific Em2plus-ELISA versus an in-house E. multilocularis-specific Em10-ELISA. Sera with discrepant confirmatory results were subjected to a commercial Echinococcus IgG Western blot (WB). In sera from patients with CE, the Em2plus-ELISA showed cross-reactions in 23.5%, whereas the Em10-ELISA did not exhibit any cross-reactivity. Cross-reactivity paralleled active infection with high antibody titers in the screening assays. In sera from patients with AE, confirmation by both ELISAs was achieved in 57.6%, mostly in patients with an advanced stage of the disease and high antibody titers in the screening assays. False-negative reactions of both ELISAs occurred in 30.3%, mostly in patients who had low antibody levels in the screening tests. The Em2plus-ELISA exhibited fewer false-negative reactions than the Em10-ELISA. The WB confirmed the positive results of either assay and was the assay with the highest reliability at different stages of CE and AE, followed by the Em2plus-ELISA for AE. High antibody titers in the screening assays will favour the detection of species-specific antibodies in either form.

Cross ketonization of Cuphea sp. oil with acetic acid over a composite oxide of Fe, Ce, and Al

USDA-ARS?s Scientific Manuscript database

The objective of this work was to demonstrate the viability of the cross ketonization reaction with the triacylglycerol from Cuphea sp. and acetic acid in a fixed-bed plug-flow reactor. The seed oil from Cuphea sp. contains up to 71% decanoic acid and the reaction of this fatty acid residue with ac...

Kondo effect with tunable spin-orbit interaction in LaTiO3/CeTiO3/SrTiO3 heterostructure.

PubMed

Ghising, Pramod; Das, Debarchan; Das, Shubhankar; Hossain, Z

2018-07-18

We have fabricated epitaxial films of CeTiO 3 (CTO) on (0 0 1) oriented SrTiO 3 (STO) substrates, which exhibit highly insulating and diamagnetic properties. X-ray photoelectron spectroscopy was used to establish the 3+  valence state of the Ce and Ti ions. Furthermore, we have also fabricated δ (CTO) doped LaTiO 3 (LTO)/SrTiO 3 thin films which exhibit variety of interesting properties including Kondo effect and spin-orbit interaction (SOI) at low temperatures. The SOI shows a non-monotonic behaviour as the thickness of the CTO layer is increased and is reflected in the value of characteristic SOI field ([Formula: see text]) obtained from weak anti-localization fitting. The maximum value of [Formula: see text] is 1.00 T for δ layer thickness of 6 u.c. This non-monotonic behaviour of SOI is attributed to the strong screening of the confining potential at the interface. The screening effect is enhanced by the CTO layer thickness and the dielectric constant of STO which increases at low temperatures. Due to the strong screening, electrons confined at the interface are spread deeper into the STO bulk where it starts to populate the Ti [Formula: see text] subbands; consequently the Fermi level crosses over from [Formula: see text] to the [Formula: see text] subbands. At the crossover region of [Formula: see text] where there is orbital mixing, SOI goes through a maximum.

Initial Reduction of CO2 on Pd-, Ru-, and Cu-Doped CeO2(111) Surfaces: Effects of Surface Modification on Catalytic Activity and Selectivity.

PubMed

Guo, Chen; Wei, Shuxian; Zhou, Sainan; Zhang, Tian; Wang, Zhaojie; Ng, Siu-Pang; Lu, Xiaoqing; Wu, Chi-Man Lawrence; Guo, Wenyue

2017-08-09

Surface modification by metal doping is an effective treatment technique for improving surface properties for CO 2 reduction. Herein, the effects of doped Pd, Ru, and Cu on the adsorption, activation, and reduction selectivity of CO 2 on CeO 2 (111) were investigated by periodic density functional theory. The doped metals distorted the configuration of a perfect CeO 2 (111) by weakening the adjacent Ce-O bond strength, and Pd doping was beneficial for generating a highly active O vacancy. The analyses of adsorption energy, charge density difference, and density of states confirmed that the doped metals were conducive for enhancing CO 2 adsorption, especially for Cu/CeO 2 (111). The initial reductive dissociation CO 2 → CO* + O* on metal-doped CeO 2 (111) followed the sequence of Cu- > perfect > Pd- > Ru-doped CeO 2 (111); the reductive hydrogenation CO 2 + H → COOH* followed the sequence of Cu- > perfect > Ru- > Pd-doped CeO 2 (111), in which the most competitive route on Cu/CeO 2 (111) was exothermic by 0.52 eV with an energy barrier of 0.16 eV; the reductive hydrogenation CO 2 + H → HCOO* followed the sequence of Ru- > perfect > Pd-doped CeO 2 (111). Energy barrier decomposition analyses were performed to identify the governing factors of bond activation and scission along the initial CO 2 reduction routes. Results of this study provided deep insights into the effect of surface modification on the initial reduction mechanisms of CO 2 on metal-doped CeO 2 (111) surfaces.

In-house-made capillary electrophoresis instruments coupled with contactless conductivity detection as a simple and inexpensive solution for water analysis: a case study in Vietnam.

PubMed

Duong, Hong Anh; Le, Minh Duc; Nguyen, Kim Diem Mai; Hauser, Peter C; Pham, Hung Viet; Mai, Thanh Duc

2015-11-01

A simple and inexpensive method for the determination of various ionic species in different water matrices is discussed in this study. The approach is based on the employment of in-house-made capillary electrophoresis (CE) instruments with capacitively coupled contactless conductivity detection (C(4)D), which can be realized even when only a modest financial budget and limited expertise are available. Advantageous features and considerations of these instruments are detailed following their pilot deployment in Vietnam. Different categories of ionic species, namely major inorganic cations (K(+), Na(+), Ca(2+), Mg(2+), and NH4(+)) and major inorganic anions (Cl(-), NO3(-), NO2(-), SO4(2-), and phosphate), in different water matrices in Vietnam were determined using these in-house fabricated instruments. Inorganic trivalent arsenic (As(iii)), which is the most abundant form of arsenic in reducing groundwater, was determined by CE-C(4)D. The effect of some interfering ions in groundwater on the analytical performance was investigated and is highlighted. The results from in-house-made CE-C(4)D-instruments were cross-checked with those obtained using the standard methods (AAS, AES, UV and IC), with correlation coefficients r(2) ≥ 0.9 and deviations from the referenced results less than 15%.

Long annealing effect on spin Seebeck devices fabricated using Ce x Y3- x Fe5O12 deposited by metal-organic decomposition

NASA Astrophysics Data System (ADS)

Ono, Tatsuyoshi; Hirata, Satoshi; Amemiya, Yoshiteru; Tabei, Tetsuo; Yokoyama, Shin

2018-04-01

The effects of Ce content and annealing temperature on the electromotive force produced by spin Seebeck devices fabricated using Ce x Y3- x Fe5O12 deposited by metal-organic decomposition was investigated. The Ce content was first varied (x = 0,1,2,3) for a fixed annealing condition of 3 h at 900 °C. It was found that increasing the Ce content led to a decrease in electromotive force, which meant that x = 0 was the optimum Ce content. Next, the effect of annealing temperature was investigated for a Ce1Y2Fe5O12 film for an annealing time of 14 h. The highest electromotive force of 24.0 µV/50 °C was obtained for a sample annealed for 14 h at 800 °C, although the X-ray diffraction peaks were weaker than those for a sample annealed for 14 h at 950 °C.

Influence of the physico-chemical properties of CeO 2-ZrO 2 mixed oxides on the catalytic oxidation of NO to NO 2

NASA Astrophysics Data System (ADS)

Atribak, Idriss; Guillén-Hurtado, Noelia; Bueno-López, Agustín; García-García, Avelina

2010-10-01

Commercial and home-made Ce-Zr catalysts prepared by co-precipitation were characterised by XRD, Raman spectroscopy, N 2 adsorption at -196 °C and XPS, and were tested for NO oxidation to NO 2. Among the different physico-chemical properties characterised, the surface composition seems to be the most relevant one in order to explain the NO oxidation capacity of these Ce-Zr catalysts. As a general trend, Ce-Zr catalysts with a cerium-rich surface, that is, high XPS-measured Ce/Zr atomic surface ratios, are more active than those with a Zr-enriched surface. The decrease in catalytic activity of the Ce-Zr mixed oxided upon calcinations at 800 °C with regard to 500 °C is mainly attributed to the decrease in Ce/Zr surface ratio, that is, to the surface segregation of Zr. The phase composition (cubic or t'' for Ce-rich compositions) seems not to be a direct effect on the catalytic activity for NO oxidation in the range of compositions tested. However, the formation of a proper solid solution prevents important surface segregation of Zr upon calcinations at high temperature. The effect of the BET surface area in the catalytic activity for NO oxidation of Ce-Zr mixed oxides is minor in comparison with the effect of the Ce/Zr surface ratio.

DOE Office of Scientific and Technical Information (OSTI.GOV)

You, Guoxiang

The extended DLVO (XDLVO) theory was applied to elucidate the potential effects of CeO{sub 2} nanoparticles (CeO{sub 2} NPs) on sludge aggregation and the role of extracellular polymeric substances (EPS). In this study, seven different concentrations of CeO{sub 2} NPs were added to activated sludge cultured in sequencing batch reactors (SBRs) and compared with a control test that received no CeO{sub 2} NPs. After exposure to 50 mg/L CeO{sub 2} NPs, a negligible change (p>0.1) occurred in the sludge volume index (SVI), whereas the flocculability and aggregation of the sludge decreased by 18.8% and 11.2%, respectively, resulting in a highmore » effluent turbidity. The XDLVO theory demonstrated that the adverse effects of the CeO{sub 2} NPs on sludge aggregation were due to an enhanced barrier energy. Compared to the van der Waals energies (W{sub A}) and the electric double layer (W{sub R}), the acid-base interaction (W{sub AB}) markedly changed for the various concentrations of CeO{sub 2} NPs. The EPS played a decisive role in the sludge surface characteristics, as the removal of EPS equals to the negative effects induced by 5–10 mg/L CeO{sub 2} NPs on the sludge flocculability and aggregation. The presence of CeO{sub 2} NPs induced negative contributions to the tight boundary EPS (TB-EPS) and core bacteria while positive contributions to the total interaction energy of the loose boundary EPS (LB-EPS). - Highlights: • CeO{sub 2} NPs adversely affected the flocculability and aggregation of the sludge. • The presence of CeO{sub 2} NPs increased the energy barrier and led to a stable suspension. • The removal of EPS equals to the negative effects induced by 5–10 mg/L CeO{sub 2} NPs. • The acid-base interaction was dominate and markedly changed for the CeO{sub 2} NPs. • CeO{sub 2} NPs induced negative contributions to the TB-EPS while positive to the LB-EPS.« less

Near-infrared quantum-cutting luminescence and energy transfer properties of Ca{sub 3}(PO{sub 4}){sub 2}:Tm{sup 3+},Ce{sup 3+} phosphors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, S. L.; Lin, H. H., E-mail: linhh@hstc.edu.cn, E-mail: qyzhang@scut.edu.cn; Yu, T.

2014-07-14

The phosphors Ca{sub 3}(PO{sub 4}){sub 2}:Tm{sup 3+} by co-doping Ce{sup 3+} have been synthesized by conventional high-temperature solid-state reaction method. Their spectroscopic properties in the UV-VIS-NIR range have been investigated. The first 5d crystal field level location and stokes shift have been determined from the UV excitation and emission spectra of Ca{sub 3}(PO{sub 4}){sub 2}:Ce{sup 3+}. The three-photon NIR quantum-cutting luminescence of Tm{sup 3+} assigned to the electronic transitions of {sup 1}G{sub 4}→{sup 3}H{sub 4}, {sup 3}H{sub 4}→{sup 3}F{sub 4} and {sup 3}F{sub 4}→{sup 3}H{sub 6} is observed, whether in Ca{sub 3}(PO{sub 4}){sub 2}:Tm{sup 3+} or Ca{sub 3}(PO{sub 4}){sub 2}:Tm{supmore » 3+},Ce{sup 3+}. The energy transfer from Ce{sup 3+} to Tm{sup 3+} takes place with energy-transfer efficiency up to 34.5% for the Ca{sub 3}(PO{sub 4}){sub 2}:Tm{sup 3+},Ce{sup 3+}. A cross relaxation scheme using the 5d states of Ce{sup 3+} and f-f transition of Tm{sup 3+} is proposed. The mechanism is revealed from energy level and decay measurements. The results show that the broadband absorption of Ce{sup 3+} sensitizer not only extends the spectrum conversion in UV region but also greatly enhances the photoluminescence intensities of the three-photon quantum cutting luminescence of Tm{sup 3+} doped Ca{sub 3}(PO{sub 4}){sub 2}.« less

Intergenerational responses of wheat (Triticum aestivum L.) to ...

EPA Pesticide Factsheets

The intergenerational impact of engineered nanomaterials in plants is a key knowledge gap in the literature. A soil microcosm study was performed to assess the effects of multi-generational exposure of wheat (Triticum aestivum L.) to cerium oxide nanoparticles (CeO2-NPs). Seeds from plants that were exposed to 0, 125, and 500 mg CeO2-NPs/kg soil (Ce-0, Ce-125 or Ce-500, respectively) in first generation (S1) were cultivated in factorial combinations of Ce-0, Ce-125 or Ce-500 to produce second generation (S2) plants. The factorial combinations for first/second generation treatments in Ce-125 were S1-Ce-0/S2-Ce-0, S1-Ce-0/S2-Ce-125, S1-Ce-125/S2-Ce-0 and S1-Ce-125/S2-Ce-125, and in Ce-500 were S1-Ce-0/S2-Ce-0, S1-Ce-0/S2-Ce-500, S1-Ce-500/S2-Ce-0 and S1-Ce-500/S2-Ce-500. Agronomic, elemental, and isotopic data were collected in second generation plants. Results showed that plants treated during the first generation only with either Ce-125 or Ce-500 (e.g. S1-Ce-125/S2-Ce-0 or S1-Ce-500/S2-Ce-0) had reduced accumulation of Ce (61 or 50%), Fe (49 or 58%) and Mn (34 or 41%) in roots, and δ15N (11 or 8%) in grains compared to the plants not treated in both generations (i.e. S1-Ce-0/S2-Ce-0). In addition, plants treated in both generations with Ce-125 (i.e. S1-Ce-125/S2-Ce-125) produced grains that had lower Mn, Ca, K, Mg and P relative to plants treated in the second generation only (i.e. S1-Ce-0/S2-Ce-125). The findings demonstrated that first generation exposure of

Cost-effectiveness analysis and innovation.

PubMed

Jena, Anupam B; Philipson, Tomas J

2008-09-01

While cost-effectiveness (CE) analysis has provided a guide to allocating often scarce resources spent on medical technologies, less emphasis has been placed on the effect of such criteria on the behavior of innovators who make health care technologies available in the first place. A better understanding of the link between innovation and cost-effectiveness analysis is particularly important given the large role of technological change in the growth in health care spending and the growing interest of explicit use of CE thresholds in leading technology adoption in several Westernized countries. We analyze CE analysis in a standard market context, and stress that a technology's cost-effectiveness is closely related to the consumer surplus it generates. Improved CE therefore often clashes with interventions to stimulate producer surplus, such as patents. We derive the inconsistency between technology adoption based on CE analysis and economic efficiency. Indeed, static efficiency, dynamic efficiency, and improved patient health may all be induced by the cost-effectiveness of the technology being at its worst level. As producer appropriation of the social surplus of an innovation is central to the dynamic efficiency that should guide CE adoption criteria, we exemplify how appropriation can be inferred from existing CE estimates. For an illustrative sample of technologies considered, we find that the median technology has an appropriation of about 15%. To the extent that such incentives are deemed either too low or too high compared to dynamically efficient levels, CE thresholds may be appropriately raised or lowered to improve dynamic efficiency.

The effect of crataegus fruit extract and some of its flavonoids on mitochondrial oxidative phosphorylation in the heart.

PubMed

Bernatoniene, J; Trumbeckaite, S; Majiene, D; Baniene, R; Baliutyte, G; Savickas, A; Toleikis, A

2009-12-01

Crataegus (Hawthorn) fruit extracts (CE) are widely used for the treatment of various cardiovascular diseases (arrhythmias, heart failure, myocardial weakness, etc). Despite the fact that many of these diseases are associated with disturbances of the mitochondria, no data have been found on the effect of CE on their function. The aim of this study was to perform an oxygraphic investigation of the effect of CE (in concentration range from 70 ng/mL to 13.9 microg/mL of Crataegus phenolic compounds (PC)) and its several pure flavonoids on isolated rat heart mitochondria respiring on pyruvate+malate, succinate and palmitoyl-L-carnitine+malate. CE at doses under 278 ng/mL of PC had no effect on mitochondrial functions. At concentrations from 278 ng/mL to 13.9 microg/mL of PC, CE stimulated State 2 respiration by 11%-34% with all used substrates, and decreased the mitochondrial membrane potential by 1.2-4.4 mV measured with a tetraphenylphosphonium-selective electrode and H2O2 production measured fluorimetrically. Similar uncoupling effects on mitochondrial respiration were observed with several pure CE flavonoids. The highest CE concentration also slightly reduced the maximal ADP-stimulated and uncoupled respiration, which might be due to inhibition of the mitochondrial respiratory chain between flavoprotein and cytochrome c. Whether or not the uncoupling and other effects of CE on mitochondria may be realized in vivo remains to be determined. Copyright (c) 2009 John Wiley & Sons, Ltd.

Near-infrared light activation of quenched liposomal Ce6 for synergistic cancer phototherapy with effective skin protection.

PubMed

Feng, Liangzhu; Tao, Danlei; Dong, Ziliang; Chen, Qian; Chao, Yu; Liu, Zhuang; Chen, Meiwan

2017-05-01

Current photodynamic therapy (PDT) is suffering from limited efficacy towards hypoxia tumors and severe post-treatment photo-toxicity such as light-induced skin damages. To make PDT more effective in cancer treatment while being patient-comfortable, herein, a hexylamine conjugated chlorin e6 (hCe6) as the photosensitizer together with a lipophilic near-infrared (NIR) dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide (DiR) are co-encapsulated into polyethylene glycol (PEG) shelled liposomes. In the obtained DiR-hCe6-liposome, the photosensitizing effect of hCe6 is quenched by DiR via fluorescence resonance energy transfer (FRET). Interestingly, upon irradiation with a 785-nm NIR laser to photobleach DiR, both fluorescence and photodynamic effect of hCe6 in DiR-hCe6-liposome would be activated. Meanwhile, such NIR irradiation applied on tumors of mice with intravenous injection of DiR-hCe6-liposome could result in mild photothermal heating, which in turn would promote intra-tumor blood flow and relieve tumor hypoxia, contributing to the enhanced photodynamic tumor treatment. Importantly, compared to hCe6-loaded liposomes, DiR-hCe6-liposome without being activated by the 785-nm laser shows much lower skin photo-toxicity, demonstrating its great skin protection effect. This work demonstrates a promising yet simple strategy to prepare NIR-light-activatable photodynamic theranostics for synergistic cancer phototherapy, which is featured high specificity/efficacy in tumor treatment with minimal photo-toxicity towards the skin. Copyright © 2016. Published by Elsevier Ltd.

Effect of the Cerium Oxide (CeO2) on the Structural and Electrochemical Properties of the LaNi5Ce Metal Hydride Anode

NASA Astrophysics Data System (ADS)

Utami Hapsari, Ade; Zulfia, Anne; Raharjo, Jarot; Agustanhakri

2017-07-01

One of negative electrode, AB5-type alloy electrodes, have been extensively studied and applied in rechargeable Ni-MH batteries due to their excellent electrochemical characteristics. Some researchers have found that addition of rare earth oxides (La, Ce, Pr, Er, Tm, Yb) to AB5-type alloy (MH) electrode improves battery performance significantly. Cerium Oxide (CeO2) is a light rare earth oxide is widely obtained from the processing of tailings in mining activities. During this time, there is still little data for research applications of cerium oxide for electrode materials. In this paper, the effects of adding CeO2 on the performance metal hydride electrode were investigated. In order to study the effects of CeO2 on the performance of anode material, 1%, 2%, and 3% of weight ratio CeO2 was mixed to LaNi5 as an negative electrode. The powder mixtures were mechanically milled at a speed of rpm 240 for 2 hours using ball mill. The powder mixtures were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). Electrochemical characteristics were measured using electrochemical impedance spectroscopy (EIS). The powder mixing showed the presence of Ce atom substitution into LaNi5 structures that affect the electrochemical properties of the material. The addition of cerium oxide at LaNi5 increase of the value of impedance. However, the addition of the value of impedance at 1% CeO2 is not significant when compared with the addition of 2% and 3% CeO2 that actually make the electrochemical properties of LaNi5 worst. Although the addition of 1% CeO2 also slightly increases the impedance value of LaNi5, but the addition of 1% CeO2 showed increase the corrosion resistance than without the addition of CeO2 and the addition of 2% and 3% CeO2.

Glutamatergic transmission in the central nucleus of the amygdala is selectively altered in Marchigian Sardinian alcohol-preferring rats: alcohol and CRF effects

PubMed Central

Herman, Melissa A.; Varodayan, Florence P.; Oleata, Christopher S.; Luu, George; Kirson, Dean; Heilig, Markus; Ciccocioppo, Roberto; Roberto, Marisa

2015-01-01

The CRF system of the central nucleus of the amygdala (CeA) is important for the processing of anxiety, stress, and effects of acute and chronic ethanol. We previously reported that ethanol decreases evoked glutamate transmission in the CeA of Sprague Dawley rats and that ethanol dependence alters glutamate release in the CeA. Here, we examined the effects of ethanol, CRF and a CRF1 receptor antagonist on spontaneous and evoked glutamatergic transmission in CeA neurons from Wistar and Marchigian Sardinian Preferring (msP) rats, a rodent line genetically selected for excessive alcohol drinking and characterized by heightened activity of the CRF1 system. Basal spontaneous and evoked glutamate transmission in CeA neurons from msP rats was increased compared to Wistar rats. Ethanol had divergent effects, either increasing or decreasing spontaneous glutamate release in the CeA of Wistar rats. This bidirectional effect was retained in msP rats, but the magnitude of the ethanol-induced increase in glutamate release was significantly smaller. The inhibitory effect of ethanol on evoked glutamatergic transmission was similar in both strains. CRF also either increased or decreased spontaneous glutamate release in CeA neurons of Wistar rats, however, in msP rats CRF only increased glutamate release. The inhibitory effect of CRF on evoked glutamatergic transmission was also lost in neurons from msP rats. A CRF1 antagonist produced only minor effects on spontaneous glutamate transmission, which were consistent across strains, and no effects on evoked glutamate transmission. These results demonstrate that the genetically altered CRF system of msP rats results in alterations in spontaneous and stimulated glutamate signaling in the CeA that may contribute to both the anxiety and drinking behavioral phenotypes. PMID:26519902

The effect of cerium (III) on the chlorophyll formation in spinach.

PubMed

Fashui, Hong; Ling, Wang; Xiangxuan, Meng; Zheng, Wei; Guiwen, Zhao

2002-12-01

The effect of Ce(3+) on the chlorophyll (chl) of spinach was studied in pot culture experiments. The results showed that Ce(3+) could obviously stimulate the growth of spinach and increase its chlorophyll contents and photosynthetic rate. It could also improve the PSII formation and enhance its electron transport rate of PSII as well. By inductively coupled plasma-mass spectroscopy and atom absorption spectroscopy methods, it was revealed that the rare-earth-element (REE) distribution pattern in the Ce(3+)-treated spinach was leaf > root > shoot in Ce(3+) contents. The spinach leaves easily absorbed REEs. The Ce(3+) contents of chloroplast and chlorophyll of the Ce(3+)-treated spinach were higher than that of any other rare earth and were much higher than that of the control; it was also suggested that Ce(3+) could enter the chloroplast and bind easily to chlorophyll and might replace magnesium to form Ce-chlorophyll. By ultraviolet-visible, Fourier transform infrared, and extended X-ray absorption fine structure (EXAFS) methods, Ce(3+)-coordinated nitrogen of porphyrin rings with eight coordination numbers and average length of the Ce-N bond of 0.251 nm.

Effects of Ce on Inclusions, Microstructure, Mechanical Properties, and Corrosion Behavior of AISI 202 Stainless Steel

NASA Astrophysics Data System (ADS)

Cai, Guojun; Li, Changsheng

2015-10-01

The sizes and morphologies of nonmetallic inclusions, microhardness, tensile strength, and Charpy impact toughness in AISI 202 stainless steel with different Ce contents were synthetically analyzed by means of SEM, TEM, microhardness tester, and tensile and Charpy impact tests. Effects of Ce addition on the corrosion behavior were investigated in 5 wt.% H2SO4 solution for different periods of time through measuring AC impedance. The EIS measurements indicate that the steels with Ce addition exhibit higher R p values than those without Ce, which illustrates the relative resistance to uniform corrosion is accompanied by an increasing Ce addition. Ce addition to AISI 202 stainless steel improves its uniform corrosion resistance owing to metamorphic inclusions and the improvement of electrode potential in matrix. Upon increasing Ce addition, the indentation morphology of samples transfers from sink-in types to pile-up types, explaining good machinability of steels containing Ce. It is witnessed from the fracture mode that Ce refines the grain size of steels, significantly increasing the strength; in the meantime, its plasticity is improved, thereby solving the contradiction between the strength and the plasticity of steels. It is concluded that AISI 202 stainless steel with 0.016 wt.% Ce addition in the mass fraction has the best mechanical properties and the uniform corrosion resistance.

Photosensitizer-Loaded Branched Polyethylenimine-PEGylated Ceria Nanoparticles for Imaging-Guided Synchronous Photochemotherapy.

PubMed

Yang, Zhang-You; Li, Hong; Zeng, Yi-Ping; Hao, Yu-Hui; Liu, Cong; Liu, Jing; Wang, Wei-Dong; Li, Rong

2015-11-04

A multifunctional theranostic platform based on photosensitizer (chlorin e6, Ce6)-loaded branched polyethylenimine-PEGylated ceria nanoparticles (PPCNPs-Ce6) was created for the development of effective cancer treatments involving the use of imaging-guided synchronous photochemotherapy. PPCNPs-Ce6 with high Ce6 photosensitizer loading (Ce6: cerium ∼40 wt %) significantly enhanced the delivery of Ce6 into cells and its accumulation in lysosomes, remarkably improving photodynamic therapeutic (PDT) efficacy levels compared to those in the administration of free Ce6 at ultralow drug doses (∼200 nM). Interestingly, PPCNPs-Ce6 efficiently induced HeLa cell death even at low concentrations (∼10 μM) without the use of laser irradiation and exhibit chemocytotoxicity. Inductively coupled plasma mass spectrometry (ICP-MS) and biology transmission electron microscopy (Bio-TEM) analyses demonstrated that ceria nanoparticles enter cells abundantly and accumulate in lysosomes or large vesicles. We then evaluated the effects of the different materials on lysosomal integrity and function, which revealed that PPCNPs-Ce6 catastrophically impaired lysosomal function compared to results with PPCNPs and Ce6. Studies of apoptosis revealed greater induction of apoptosis by PPCNPs-Ce6 treatment. This multifunctional nanocarrier also exhibited a high degree of solubility and stability in aqueous solutions, suggesting its applicability for extensive biomedical application.

Exploring the role of community engagement in improving the health of disadvantaged populations: a systematic review

PubMed Central

Cyril, Sheila; Smith, Ben J.; Possamai-Inesedy, Alphia; Renzaho, Andre M. N.

2015-01-01

Background Although community engagement (CE) is widely used in health promotion, components of CE models associated with improved health are poorly understood. This study aimed to examine the magnitude of the impact of CE on health and health inequalities among disadvantaged populations, which methodological approaches maximise the effectiveness of CE, and components of CE that are acceptable, feasible, and effective when used among disadvantaged populations. Design The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We carried out methodological assessments of the included studies using rating scales. The analysis focussed on model synthesis to identify the key CE components linked to positive study outcomes and comparative analysis between positive study outcomes, processes, and quality indicators of CE. Results Out of 24 studies that met our inclusion criteria, 21 (87.5%) had positively impacted health behaviours, public health planning, health service access, health literacy, and a range of health outcomes. More than half of the studies (58%) were of good quality, whereas 71% and 42% of studies showed good community involvement in research and achieved high levels of CE, respectively. Key CE components that affected health outcomes included real power-sharing, collaborative partnerships, bidirectional learning, incorporating the voice and agency of beneficiary communities in research protocol, and using bicultural health workers for intervention delivery. Conclusions The findings suggest that CE models can lead to improved health and health behaviours among disadvantaged populations if designed properly and implemented through effective community consultation and participation. We also found several gaps in the current measurement of CE in health intervention studies, which suggests the importance of developing innovative approaches to measure CE impact on health outcomes in a more rigorous way. PMID:26689460

Achieving High Strength and Good Ductility in As-Extruded Mg–Gd–Y–Zn Alloys by Ce Micro-Alloying

PubMed Central

Gao, Zhengyuan; Hu, Linsheng; Li, Jinfeng; An, Zhiguo; Li, Jun; Huang, Qiuyan

2018-01-01

In this study, the effect of Ce additions on microstructure evolution of Mg–7Gd–3.5Y–0.3Zn (wt %) alloys during the casting, homogenization, aging and extrusion processing are investigated, and novel mechanical properties are also obtained. The results show that Ce addition promotes the formation of long period stacking ordered (LPSO) phases in the as-cast Mg–Gd–Y–Zn–Ce alloys. A high content of Ce addition would reduce the maximum solubility of Gd and Y in the Mg matrix, which leads to the higher density of Mg12Ce phases in the as-homogenized alloys. The major second phases observed in the as-extruded alloys are micron-sized bulk LPSO phases, nano-sized stripe LPSO phases, and broken Mg12Ce and Mg5RE phases. Recrystallized grain size of the as-extruded 0.2Ce, 0.5Ce and 1.0Ce alloys can be refined to ~4.3 μm, ~1.0 μm and ~8.4 μm, respectively, which is caused by the synthesized effect of both micron phases and nano phases. The strength and ductility of as-extruded samples firstly increase and then decrease with increasing Ce content. As-extruded 0.5Ce alloy exhibits optimal mechanical properties, with ultimate strength of 365 MPa and ductility of ~15% simultaneously. PMID:29320471

Effect of Dopants on the Adsorption of Carbon Dioxide on Ceria Surfaces

DOE PAGES

Li, Meijun; Tumuluri, Uma; Wu, Zili; ...

2015-09-25

Here, high-surface-area nanosized CeO 2 and M-doped CeO 2 (M=Cu, La, Zr, and Mg) prepared by a surfactant-templated method were tested for CO 2 adsorption. Cu, La, and Zr are doped into the lattice of CeO 2, whereas Mg is dispersed on the CeO 2 surface. The doping of Cu and La into CeO 2 leads to an increase of the CO 2 adsorption capacity, whereas the doping of Zr has little or no effect. The addition of Mg causes a decrease of the CO 2 adsorption capacity at a low Mg content and a gradual increase at a highermore » content. The CO 2 adsorption capacity follows the sequence Cu-CeO 2>La-CeO 2>Zr-CeO 2≈CeO 2>Mg-CeO 2 at low dopant contents, in line with the relative amount of defect sites in the samples. It is the defect sites on the surface, not in the bulk of CeO 2, modified by the dopants that play the vital role in CO 2 chemisorption. Lastly, the role of surface oxygen vacancies is further supported by an in situ IR spectroscopic study of the surface chemistry during CO 2 adsorption on the doped CeO 2.« less

Magnetic properties and microstructure of melt-spun Ce17Fe78-xB6Hfx (x = 0-1.0) alloys

NASA Astrophysics Data System (ADS)

Jiang, Qingzheng; Zhong, Minglong; Quan, Qichen; Lei, Weikai; Zeng, Qingwen; Hu, Yongfeng; Xu, Yaping; Hu, Xianjun; Zhang, Lili; Liu, Renhui; Ma, Shengcan; Zhong, Zhenchen

2017-12-01

Ce17Fe78-xB6Hfx (x = 0-1.0) alloys were fabricated by a melt-spinning technique in order to study their magnetic properties and microstructure. Magnetic investigations of Ce17Fe78-xB6Hfx (x = 0-1.0) alloys show that the room-temperature coercivity increases linearly from 352 kA/m at x = 0 to 420 kA/m at x = 1.0. The Curie temperature (Tc) decreases monotonically from 424.5 K to 409.1 K. The Ce L3-edge X-ray absorption near edge structure (XANES) spectrums reveal that there is more Ce4+ in ribbons under total electron yield (TEY) than fluorescence yield (FY). Hf addition has no effect on the weight of Ce3+ and Ce4+ in CeFeB-based alloys. The grain refinement and microstructure uniformity are essential for improving the magnetic properties of Hf-doped alloys. This paper may shed light on the further development of the Ce-based magnets and offer a feasible way for using the rare earth resources effectively.

Working memory and intraindividual variability as neurocognitive indicators in ADHD: examining competing model predictions.

PubMed

Kofler, Michael J; Alderson, R Matt; Raiker, Joseph S; Bolden, Jennifer; Sarver, Dustin E; Rapport, Mark D

2014-05-01

The current study examined competing predictions of the default mode, cognitive neuroenergetic, and functional working memory models of attention-deficit/hyperactivity disorder (ADHD) regarding the relation between neurocognitive impairments in working memory and intraindividual variability. Twenty-two children with ADHD and 15 typically developing children were assessed on multiple tasks measuring intraindividual reaction time (RT) variability (ex-Gaussian: tau, sigma) and central executive (CE) working memory. Latent factor scores based on multiple, counterbalanced tasks were created for each construct of interest (CE, tau, sigma) to reflect reliable variance associated with each construct and remove task-specific, test-retest, and random error. Bias-corrected, bootstrapped mediation analyses revealed that CE working memory accounted for 88% to 100% of ADHD-related RT variability across models, and between-group differences in RT variability were no longer detectable after accounting for the mediating role of CE working memory. In contrast, RT variability accounted for 10% to 29% of between-group differences in CE working memory, and large magnitude CE working memory deficits remained after accounting for this partial mediation. Statistical comparison of effect size estimates across models suggests directionality of effects, such that the mediation effects of CE working memory on RT variability were significantly greater than the mediation effects of RT variability on CE working memory. The current findings question the role of RT variability as a primary neurocognitive indicator in ADHD and suggest that ADHD-related RT variability may be secondary to underlying deficits in CE working memory.

Role of cerium oxide nanoparticle-induced autophagy as a safeguard to exogenous H2O2-mediated DNA damage in tobacco BY-2 cells.

PubMed

Sadhu, Abhishek; Ghosh, Ilika; Moriyasu, Yuji; Mukherjee, Anita; Bandyopadhyay, Maumita

2018-04-13

The effect of cerium oxide nanoparticle (CeNP) in plants has elicited substantial controversy. While some investigators have reported that CeNP possesses antioxidant properties, others observed CeNP to induce reactive oxygen species (ROS). In spite of considerable research carried out on the effects of CeNP in metazoans, fundamental studies that can unveil its intracellular consequences linking ROS production, autophagy and DNA damage are lacking in plants. To elucidate the impact of CeNP within plant cells, tobacco BY-2 cells were treated with 10, 50 and 250 µg ml-1 CeNP (Ce10, Ce50 and Ce250), for 24 h. Results demonstrated concentration-dependent accumulation of Ca2+ and ROS at all CeNP treatment sets. However, significant DNA damage and alteration in antioxidant defence systems were noted prominently at Ce50 and Ce250. Moreover, Ce50 and Ce250 induced DNA damage, analysed by comet assay and DNA diffusion experiments, complied with the concomitant increase in ROS. Furthermore, to evaluate the antioxidant property of CeNP, treated cells were washed after 24 h (to minimise CeNP interference) and challenged with H2O2 for 3 h. Ce10 did not induce genotoxicity and H2O2 exposure to Ce10-treated cells showed lesser DNA breakage than cells treated with H2O2 only. Interestingly, Ce10 provided better protection over N-acetyl-L-cysteine against exogenous H2O2 in BY-2 cells. CeNP exposure to transgenic BY-2 cells expressing GFP-Atg8 fusion protein exhibited formation of autophagosomes at Ce10. Application of vacuolar protease inhibitor E-64c and fluorescent basic dye acridine orange, further demonstrated accumulation of particulate matters in the vacuole and occurrence of acidic compartments, the autophagolysosomes, respectively. BY-2 cells co-treated with CeNP and autophagy inhibitor 3-methyladenine exhibited increased DNA damage in Ce10 and cell death at all assessed treatment sets. Thus, current results substantiate an alternative autophagy-mediated, antioxidant and geno-protective role of CeNP, which will aid in deciphering novel phenomena of plant-nanoparticle interaction at cellular level.

The effects of physicochemical properties of CeO2 nanoparticles on toxicity to soil denitrification processes

NASA Astrophysics Data System (ADS)

Dahle, Jessica Teague

The studies presented in this thesis identify the impact of NP CeO 2 on soil denitrifying microbial communities and reveal that physical and chemical characteristics including particle size, speciation, concentration, pH, and presence of ligands are key to predicting environmental fate and reactivity of NP CeO2 in the soil. A review of the literature in Chapter 1 revealed a widespread lack of toxicological information for soil exposures to NP CeO2. Soil denitrifying bacteria are a keystone species because they serve an important role in the global nitrogen cycle controlling the atmospheric nitrogen input. Soil denitrifiers are important to this study because the reducing conditions during denitrification could induce phase transformation of Ce(IV) to Ce(III), potentially influencing the toxicity of Ce. Cerium is well known for being the only lanthanide that is thermodynamically stable in both the trivalent and tetravalent state in low temperature geochemical environments. Using well characterized NP Ce(IV)O 2 as well as bulk soluble Ce(III), batch denitrification experiments were conducted to evaluate the toxicity of Ce species to the denitrifying community in a Toccoa sandy loam soil. The statistical analysis on the antimicrobial effect on soil denitrifiers was conducted using both steady-state evaluation and zero-order kinetic models in order to compare the toxicity of the Ce(III) species to the NPs. These studies, presented in Chapter 3, show that soluble Ce(III) is far more toxic than Ce(IV)O2 NPs when an equal total concentration of Ce is used, though both species exhibit toxicity to the denitrifiers via statistically significant inhibition of soil denitrification processes. Particle-size dependent toxicity, species-dependent toxicity, and concentration-dependent toxicity were all observed in this study for both the steady-state and the kinetic evaluations. The possibility of toxicity enhancement and diminishment via dissolution and ligand complexation pathways was investigated thoroughly in Chapter 2. In addition to the equilibrium and kinetic-based toxicological assessments presented in Chapter 1, dissolution and sorption experiments were performed to gain an overall understanding of Ce biogeochemistry in the terrestrial environment post-release and reveal possible geochemical controls on toxicity. It was shown that dissolution of bioavailable Ce is pH-dependent; dissolution is only detectable at acidic pH values (< pH 5) and increases with increasing acidity. Dissolution of Ce from NP CeO2 was identified to be almost 100% Ce(III). It was also demonstrated that this dissolution is suppressed by the addition of phosphate ligand, which is largely bioavailable in soils, especially in agricultural lands. This suppression was explained by the strong sorption of phosphate ligand to NP CeO2. The elimination of bioavailable Ce(III) release from NP CeO2 by phosphate ligand is likely one of the most important controls on toxicity effects and should be a large consideration in determining the fate and transport of NP CeO2 in the aquatic and terrestrial environment. It was also demonstrated that both Ce(III) and NP CeO2 have extremely strong affinity for sorption to soil matter, which could serve as another controlling pathway. Experiments indicated that factors such as reductive transformation of NP CeO2 in soils and exchangeable Ce(III) impurity in the NPs could contribute to controls on toxicity as well. In conclusion, the studies presented in this thesis indicate that the toxicity effects of the studied Ce species to soil denitrifiers are strongly affected by physical and chemical characteristics such as speciation, pH, and bioavailable ligands. As the global market for nanomaterials rapidly expands, so does the need of the scientific community for an understanding of how these influences in environmental fate and reactivity may be key in assessing toxicological risks associated with environmental exposures to NP CeO2 as well as other engineered metal oxide nanoparticles. (Abstract shortened by UMI.)

The promoting effect of CeO2@Ce-O-P multi-core@shell structure on SO2 tolerance for selective catalytic reduction of NO with NH3 at low temperature

NASA Astrophysics Data System (ADS)

Yao, Weiyuan; Liu, Yue; Wu, Zhongbiao

2018-06-01

A series of CeO2@Ce-O-P "multi-core@shell" catalysts were synthesized in this paper for selective catalytic reduction (SCR) of NO with NH3. The experimental results had showed that CeO2@Ce-O-P-30:3 yielded best SO2 tolerance of an over 70% deNOx efficiency at 250 °C in the presence of 100 ppm SO2 for 20 h, which was much higher compared to pure Ce-O-P and CeO2 samples. Further characterization results indicated that Ce-O-P coating layer could somewhat inhibit sulfur depositing on the catalysts during SCR reaction in the presence of SO2, thereby protecting the active sites from SO2 poisoning. Especially, O2-TPD results illustrated that a great amount of active oxygen species were retained on used CeO2@Ce-O-P catalyst after a long term reaction. The synergetic effect of "multi-core@shell" structure could be attributed to such enhanced performances. The "core" CeO2 devoted abundant active oxygen sites to fulfill the SCR reaction. And the "shell" Ce-O-P could not only provide acid sites, but also protect the active oxygen species by avoiding the over-adsorption of SO2 on the catalyst. This work could provide a new way to increase the sulfur resistance for low temperature SCR catalysts.

Raman studies of nanocomposites catalysts: temperature and pressure effects of CeAl, CeMn and NiAl oxides

NASA Astrophysics Data System (ADS)

da Silva, Antonio N.; Neto, Antonio B. S.; Oliveira, Alcemira C.; Junior, Manoel C.; Junior, Jose A. L.; Freire, Paulo T. C.; Filho, Josué M.; Oliveira, Alcineia C.; Lang, Rossano

2018-06-01

High temperature and pressure effects on the physicochemical properties of binary oxides catalysts were investigated. The nanocomposites catalysts comprising of CeAl, CeMn and NiAl were characterized through various physicochemical techniques. A study of the temperature and pressure induced phenomena monitored by Raman spectroscopy was proposed and discussed. Spectral modifications of the Raman modes belonging to the CeMn suggest structural changes in the solid due to the MnO2 phase oxidation with increasing temperature. The thermal expansion and lattice anharmonicity effects were observed on CeMn due to lack of stability of the lattice vacancies. The CeAl and NiAl composites presented crystallographic stability at low temperatures however, undertake a phase transformation of NiO/Al2O3 into NiAl2O4, mostly without any deformation in its structure with increasing the temperature. It was also inferred that the binary oxides are more stables in comparison with monoxides. Detailed pressure-dependent Raman measurements of the T2g phonon mode of CeMn and NiAl revealed that the pressure contributes to modify bonds length and reduces the particles sizes of the solids. On the contrary, high pressure on CeAl sample improved the stability with addition of Al2O3 in the CeO2 lattice. The results then suggest a good stability of CeAl and NiAl composite catalysts at high pressure and low temperature and show how to prospect of tuning the catalysis for surface reactions entirely through in situ spectroscopic investigations means.

Genetic parameters for calving ease, gestation length, and birth weight in Charolais cattle.

PubMed

Mujibi, F D N; Crews, D H

2009-09-01

In this study, a 3-trait linear model was used to obtain genetic parameters for direct and maternal components of calving ease (CE), gestation length (GEST), and birth weight (BWT). Calving ease scores were transformed into Snell scores and expressed as percent unassisted calving (SC), ranging from 0 to 100% (least to greatest ease). A total of 40,420 records (n = 14,403 for CE) were obtained from the Canadian Charolais Association field database. The animal model included fixed effects of contemporary group (herd x year of birth combinations), age of heifer, and sex of calf (only for CE), whereas random effects included direct and maternal genetic effects, residual error, and permanent environmental effects (for CE). The BWT and GEST were preadjusted for age of dam and sex of calf effects. Variance components were estimated using REML. Mean SC was 83.31% (SD = 23.30) and ranged from 3.44 to 100%. Mean BWT was 46.54 kg (SD = 4.79), whereas mean GEST was 286.48 d (SD = 4.93). Direct heritability estimates for SC, BWT, and GEST were 0.14 +/- 0.02, 0.46 +/- 0.03, and 0.62 +/- 0.04, respectively, and maternal heritability estimates were 0.06 +/- 0.02, 0.14 +/- 0.02, and 0.10 +/- 0.02, respectively. The permanent environmental effect as a proportion of SC phenotypic variance was 0.35 +/- 0.11, indicating a large influence on CE. Genetic correlations of direct SC with direct BWT and GEST were -0.93 +/- 0.04 and -0.38 +/- 0.08, respectively, whereas maternal correlations were -0.69 +/- 0.14 and -0.49 +/- 0.17, respectively, illustrating the importance of including both traits in CE evaluations. Within trait direct x maternal genetic correlations were substantial and negative. Regression of average direct and average maternal EBV on year of birth yielded significant genetic trends for the direct effects of BWT, GEST, and CE, whereas no trends were detected for maternal effects. Even though CE is routinely analyzed, no study has evaluated transformed CE scores with 2 correlated traits. In these data, the large negative genetic correlation between BWT and CE suggests that increasing SC would also decrease BWT. Genetic improvement programs, therefore, should consider both CE and growth.

Studying Electron-Capture on ^64Zn in Supernovae with the (t,^3He) Charge-Exchange Reaction

NASA Astrophysics Data System (ADS)

Hitt, G. W.; Austin, Sam M.; Bazin, D.; Gade, A.; Guess, C. J.; Galaviz-Redondo, D.; Shimbara, Y.; Tur, C.; Zegers, R. G. T.; Horoi, M.; Howard, M. E.; Smith, E. E.

2008-10-01

A secondary, 115 MeV/u triton beam has been developed at NSCL for use in (t,^3He) charge-exchange(CE) reaction studies. This (n,p)-type CE reaction is useful for extracting the full Gamow-Teller (GT) response of the nucleus, overcoming Q-value restrictions present in conventional beta-decay studies. The strength (B(GT)) in ^64Cu has been determined from the absolute cross section measurement of ^64Zn(t,^3He) near zero-degrees, exploiting an empirical proportionality between cross section and B(GT). The detailed features of the B(GT) distribution in a nucleus has an important impact on electron-capture (EC) rates in Type Ia and Core-Collapse supernovae. The measured B(GT) in ^64Cu is directly compared with the results of modern shell model interactions which are used to calculate the GT contribution to EC on nuclei in supernova simulations.

Impeding effect of Ce on He bubble growth in bcc Fe

NASA Astrophysics Data System (ADS)

Hao, W.; Geng, W. T.

2012-06-01

Our first-principles density functional theory calculations suggest that the rare earth element Ce has a strong attraction to He (-1.31 eV/atom pair) in bcc Fe, even stronger than He-He attraction (-1.18 eV). The segregated Ce layer at the He bubble surface could introduce an additional energy barrier (0.40 eV) to trespassing He atoms. Therefore, Ce could not only have a pinning effect on mobile He atoms and hence reduce merging rate of He clusters, but also serve as a cover layer to repel further He atoms and thus slows down the bubble growth. The low cost makes Ce a great advantage over Au, which was recently predicted to have similar effect.

Study on the corrosion residual strength of the 1.0 wt.% Ce modified AZ91 magnesium alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li Chunfang; Liu Yaohui, E-mail: liuyaohui2005@yahoo.com; Wang Qiang

2010-01-15

The effect of corrosion on the tensile behaviour of the 1.0 wt.% Ce modified AZ91 magnesium alloy was investigated by the immersion of the test bar in 3.5 wt.% NaCl aqueous solution for 0, 12, 40, 108, 204, 372 and 468 h with the subsequent tensile tests in this paper. The fractography was analyzed by scanning electron microscopy. The results show that pitting corrosion should be responsible for the drop of the corrosion residual strength within the testing time. The depth of the corrosion pits was statistically and quantitatively obtained by an optical microscopy and the maximal value was recordedmore » as the extreme depth of the corrosion pit. Furthermore, the corrosion residual strength is linearly dependent on the extreme depth of the corrosion pit, which can be attributed to the loss of cross-sectional area and the emergence of stress concentration caused by the initiation and development of corrosion pits.« less

AT1 receptor blockade in the central nucleus of the amygdala attenuates the effects of muscimol on sodium and water intake.

PubMed

Hu, B; Qiao, H; Sun, B; Jia, R; Fan, Y; Wang, N; Lu, B; Yan, J Q

2015-10-29

The blockade of the central nucleus of the amygdala (CeA) with the GABAA receptor agonist muscimol significantly reduces hypertonic NaCl and water intake by sodium-depleted rats. In the present study we investigated the effects of previous injection of losartan, an angiotensin II type-1 (AT1) receptor antagonist, into the CeA on 0.3M NaCl and water intake reduced by muscimol bilaterally injected into the same areas in rats submitted to water deprivation-partial rehydration (WD-PR) and in rats treated with the diuretic furosemide (FURO). Male Sprague-Dawley rats with stainless steel cannulas bilaterally implanted into the CeA were used. Bilateral injections of muscimol (0.2 nmol/0.5 μl, n=8 rats/group) into the CeA in WD-PR-treated rats reduced 0.3M NaCl intake and water intake, and pre-treatment of the CeA with losartan (50 μg/0.5 μl) reversed the inhibitory effect of muscimol. The negative effect of muscimol on sodium and water intake could also be blocked by pretreatment with losartan microinjected into the CeA in rats given FURO (n=8 rats/group). However, bilateral injections of losartan (50 μg/0.5 μl) alone into the CeA did not affect the NaCl or water intake. These results suggest that the deactivation of CeA facilitatory mechanisms by muscimol injection into the CeA is promoted by endogenous angiotensin II acting on AT1 receptors in the CeA, which prevents rats from ingesting large amounts of hypertonic NaCl and water. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Quantifying and Comparing Effects of Climate Engineering Methods on the Earth System

NASA Astrophysics Data System (ADS)

Sonntag, Sebastian; Ferrer González, Miriam; Ilyina, Tatiana; Kracher, Daniela; Nabel, Julia E. M. S.; Niemeier, Ulrike; Pongratz, Julia; Reick, Christian H.; Schmidt, Hauke

2018-02-01

To contribute to a quantitative comparison of climate engineering (CE) methods, we assess atmosphere-, ocean-, and land-based CE measures with respect to Earth system effects consistently within one comprehensive model. We use the Max Planck Institute Earth System Model (MPI-ESM) with prognostic carbon cycle to compare solar radiation management (SRM) by stratospheric sulfur injection and two carbon dioxide removal methods: afforestation and ocean alkalinization. The CE model experiments are designed to offset the effect of fossil-fuel burning on global mean surface air temperature under the RCP8.5 scenario to follow or get closer to the RCP4.5 scenario. Our results show the importance of feedbacks in the CE effects. For example, as a response to SRM the land carbon uptake is enhanced by 92 Gt by the year 2100 compared to the reference RCP8.5 scenario due to reduced soil respiration thus reducing atmospheric CO2. Furthermore, we show that normalizations allow for a better comparability of different CE methods. For example, we find that due to compensating processes such as biogeophysical effects of afforestation more carbon needs to be removed from the atmosphere by afforestation than by alkalinization to reach the same global warming reduction. Overall, we illustrate how different CE methods affect the components of the Earth system; we identify challenges arising in a CE comparison, and thereby contribute to developing a framework for a comparative assessment of CE.

Estimation of the Thermodynamic Efficiency of a Solid-State Cooler Based on the Multicaloric Effect

NASA Astrophysics Data System (ADS)

Starkov, A. S.; Pakhomov, O. V.; Rodionov, V. V.; Amirov, A. A.; Starkov, I. A.

2018-03-01

The thermodynamic efficiency of using the multicaloric effect (μCE) in solid-state cooler systems has been studied in comparison to single-component caloric effects. This approach is illustrated by example of the Brayton cycle for μCE and magnetocaloric effect (MCE). Based on the results of experiments with Fe48Rh52-PbZr0.53Ti0.47O3 two-layer ferroic composite, the temperature dependence of the relative efficiency is determined and the temperature range is estimated in which the μCE is advantageous to MCE. The proposed theory of μCE is compared to experimental data.

Influence of CeO{sub 2} NPs on biological phosphorus removal and bacterial community shifts in a sequencing batch biofilm reactor with the differential effects of molecular oxygen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Yi; Wang, Chao

2016-11-15

The effects of CeO{sub 2} nanoparticles (CeO{sub 2} NPs) on a sequencing batch biofilm reactor (SBBR) with established biological phosphorus (P) removal were investigated from the processes of anaerobic P release and aerobic P uptake. At low concentration (0.1 mg/L), no significant impact was observed on total phosphorus (TP) removal after operating for 8 h. However, at a concentration of 20 mg/L, TP removal efficiency decreased from 83.68% to 55.88% and 16.76% when the CeO{sub 2} NPs were added at the beginning of the anaerobic and aerobic periods, respectively. Further studies illustrated that the inhibition of the specific P releasemore » rate was caused by the reversible states of Ce{sup 3+} and Ce{sup 4+}, which inhibited the activity of exopolyphosphatase (PPX) and transformation of poly-β-hydoxyalkanoates (PHA) and glycogen, as well as the uptake of volatile fatty acids (VFAs). The decrease in the specific P uptake rate was mainly attributed to the significantly suppressed energy generation and decreased abundance of Burkholderia caused by excess reactive oxygen species. The removal of chemical oxygen demand (COD) was not influenced by CeO{sub 2} NPs under aerobic conditions, due to the increased abundance of Acetobacter and Acidocella after exposure. The inhibitory effects of CeO{sub 2} NPs with molecular oxygen were reduced after anaerobic exposure due to the enhanced particle size and the presence of Ce{sup 3+}. - Highlights: • CeO{sub 2} NPs (20 mg/L) had a notable toxicity effect on P removal in SBBR system. • The deteriorated SPRR was caused by the inhibited key enzyme activity (PPX). • The decreased SPUR was caused by the bacterial community shifts. • Ce ions converting and excess ROS generation are related toxicity mechanisms.« less

Effect of mixing Ce{sup 3+} and Nd{sup 3+} ions in equimolar ratio on structural, optical and dielectric properties on pure cerium orthovanadate and neodymium orthovanadate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verma, Seema; Gupta, Rashmi; Bamzai, K.K., E-mail: kkbamz@yahoo.com

2016-09-15

Highlights: • CeV, NdV and mixed CeNdV nanoparticle prepared by chemical co precipitation method. • With mixing of Ce{sup 3+} and Nd{sup 3+} morphology is totally changed in mixed CeNdV. • Optical band energy of CeV, NdV and CeNdV shows good photocatalyst under UV light. • Conduction mechanism in CeV due to large polaron and small polaron in CeNdV. - Abstract: Cerium orthovanadate, neodymium orthovanadate and mixed cerium neodymium orthovanadate nanoparticles was prepared by co-precipitation method. Powder X-ray diffraction reveals tetragonal zircon structure. Slight increase in lattice parameter, volume and decrease in X-ray density inferred that Ce{sup 3+} and Nd{supmore » 3+} ion replaces each other. Transmission electron microscopy suggests change in morphology with the effect of mixing and validates formation of nanocrystalline material. The infrared transmittance spectrum confirmed the presence of various functional groups. Dielectric properties as function of frequency show dielectric constant and loss tangent decreases with increase in frequency which is due to Maxwell–Wagner type interfacial polarization. The variation of AC conductivity measurement with frequency suggests conduction mechanism due to large polaron hopping in CeV whereas small polaron in mixed CeNdV. The activation energy decreases with rising frequency indicates the conduction mechanism is based on polaron hopping between localized states in disordered manner.« less

Responses of catecholestrogen metabolism to acute graded exercise in normal menstruating women before and after training.

PubMed

De Crée, C; Ball, P; Seidlitz, B; Van Kranenburg, G; Geurten, P; Keizer, H A

1997-10-01

It has been hypothesized that exercise-related hypo-estrogenemia occurs as a consequence of increased competition of catecholestrogens (CE) for catechol-O-methyltransferase (COMT). This may result in higher norepinephrine (NE) concentrations, which could interfere with normal gonadotropin pulsatility. The present study investigates the effects of training on CE responses to acute exercise stress. Nine untrained eumenorrheic women (mean percentage of body fat +/-SD: 24.8 +/- 3.1%) volunteered for an intensive 5-day training program. Resting, submaximal, and maximal (tmax) exercise plasma CE, estrogen, and catecholamine responses were determined pre- and post training in both the follicular (FPh) and luteal phase (LPh). Acute exercise stress increased total primary estrogens (E) but had little effect on total 2-hydroxyestrogens (2-OHE) and 2-hydroxyestrogen-monomethylethers (2-MeOE) (= O-methylated CE after competition for catechol-O-methyltransferase). This pattern was not significantly changed by training. However, posttraining LPh mean (+/-SE) plasma E, 2-OHE, and 2-MeOE concentrations were significantly lower (P < 0.05) at each exercise intensity (for 2-OHE: 332 +/- 47 vs. 422 +/- 57 pg/mL at tmax; for 2-MeOE: 317 +/- 26 vs. 354 +/- 34 pg/mL at tmax). Training produced opposite effects on 2-OHE:E ratios (an estimation of CE formation) during acute exercise in the FPh (reduction) and LPh (increase). The 2-MeOE:2-OHE ratio (an estimation of CE activity) showed significantly higher values at tmax in both menstrual phases after training (FPh: +11%; LPh: +23%; P < 0.05). After training, NE values were significantly higher (P < 0.05). The major findings of this study were that: training lowers absolute concentrations of plasma estrogens and CE; the acute exercise challenge altered plasma estrogens but had little effect on CE; estimation of the formation and activity of CE suggests that formation and O-methylation of CE proportionately increases. These findings may be of importance for NE-mediated effects on gonadotropin release.

Effects of amorphous silica coating on cerium oxide nanoparticles induced pulmonary responses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Jane, E-mail: jym1@cdc.gov; Mercer, Robert R.; Barger, Mark

2015-10-01

Recently cerium compounds have been used in a variety of consumer products, including diesel fuel additives, to increase fuel combustion efficiency and decrease diesel soot emissions. However, cerium oxide (CeO{sub 2}) nanoparticles have been detected in the exhaust, which raises a health concern. Previous studies have shown that exposure of rats to nanoscale CeO{sub 2} by intratracheal instillation (IT) induces sustained pulmonary inflammation and fibrosis. In the present study, male Sprague–Dawley rats were exposed to CeO{sub 2} or CeO{sub 2} coated with a nano layer of amorphous SiO{sub 2} (aSiO{sub 2}/CeO{sub 2}) by a single IT and sacrificed at variousmore » times post-exposure to assess potential protective effects of the aSiO{sub 2} coating. The first acellular bronchoalveolar lavage (BAL) fluid and BAL cells were collected and analyzed from all exposed animals. At the low dose (0.15 mg/kg), CeO{sub 2} but not aSiO{sub 2}/CeO{sub 2} exposure induced inflammation. However, at the higher doses, both particles induced a dose-related inflammation, cytotoxicity, inflammatory cytokines, matrix metalloproteinase (MMP)-9, and tissue inhibitor of MMP at 1 day post-exposure. Morphological analysis of lung showed an increased inflammation, surfactant and collagen fibers after CeO{sub 2} (high dose at 3.5 mg/kg) treatment at 28 days post-exposure. aSiO{sub 2} coating significantly reduced CeO{sub 2}-induced inflammatory responses in the airspace and appeared to attenuate phospholipidosis and fibrosis. Energy dispersive X-ray spectroscopy analysis showed Ce and phosphorous (P) in all particle-exposed lungs, whereas Si was only detected in aSiO{sub 2}/CeO{sub 2}-exposed lungs up to 3 days after exposure, suggesting that aSiO{sub 2} dissolved off the CeO{sub 2} core, and some of the CeO{sub 2} was transformed to CePO{sub 4} with time. These results demonstrate that aSiO{sub 2} coating reduce CeO{sub 2}-induced inflammation, phospholipidosis and fibrosis. - Highlights: • Both CeO{sub 2} and aSiO{sub 2}/CeO{sub 2} particles were detected in the respective particle-exposed lungs. • The dissolution of aSiO{sub 2} coating from CeO{sub 2} particle core with time was demonstrated in the particle-exposed lungs. • aSiO{sub 2} coating significantly protected CeO{sub 2}-induced pulmonary inflammatory responses. • aSiO{sub 2} coating showed a protective effect on CeO{sub 2}-induced lung fibrosis.« less

Genetic evaluation using single-step genomic best linear unbiased predictor in American Angus.

PubMed

Lourenco, D A L; Tsuruta, S; Fragomeni, B O; Masuda, Y; Aguilar, I; Legarra, A; Bertrand, J K; Amen, T S; Wang, L; Moser, D W; Misztal, I

2015-06-01

Predictive ability of genomic EBV when using single-step genomic BLUP (ssGBLUP) in Angus cattle was investigated. Over 6 million records were available on birth weight (BiW) and weaning weight (WW), almost 3.4 million on postweaning gain (PWG), and over 1.3 million on calving ease (CE). Genomic information was available on, at most, 51,883 animals, which included high and low EBV accuracy animals. Traditional EBV was computed by BLUP and genomic EBV by ssGBLUP and indirect prediction based on SNP effects was derived from ssGBLUP; SNP effects were calculated based on the following reference populations: ref_2k (contains top bulls and top cows that had an EBV accuracy for BiW ≥0.85), ref_8k (contains all parents that were genotyped), and ref_33k (contains all genotyped animals born up to 2012). Indirect prediction was obtained as direct genomic value (DGV) or as an index of DGV and parent average (PA). Additionally, runs with ssGBLUP used the inverse of the genomic relationship matrix calculated by an algorithm for proven and young animals (APY) that uses recursions on a small subset of reference animals. An extra reference subset included 3,872 genotyped parents of genotyped animals (ref_4k). Cross-validation was used to assess predictive ability on a validation population of 18,721 animals born in 2013. Computations for growth traits used multiple-trait linear model and, for CE, a bivariate CE-BiW threshold-linear model. With BLUP, predictivities were 0.29, 0.34, 0.23, and 0.12 for BiW, WW, PWG, and CE, respectively. With ssGBLUP and ref_2k, predictivities were 0.34, 0.35, 0.27, and 0.13 for BiW, WW, PWG, and CE, respectively, and with ssGBLUP and ref_33k, predictivities were 0.39, 0.38, 0.29, and 0.13 for BiW, WW, PWG, and CE, respectively. Low predictivity for CE was due to low incidence rate of difficult calving. Indirect predictions with ref_33k were as accurate as with full ssGBLUP. Using the APY and recursions on ref_4k gave 88% gains of full ssGBLUP and using the APY and recursions on ref_8k gave 97% gains of full ssGBLUP. Genomic evaluation in beef cattle with ssGBLUP is feasible while keeping the models (maternal, multiple trait, and threshold) already used in regular BLUP. Gains in predictivity are dependent on the composition of the reference population. Indirect predictions via SNP effects derived from ssGBLUP allow for accurate genomic predictions on young animals, with no advantage of including PA in the index if the reference population is large. With the APY conditioning on about 10,000 reference animals, ssGBLUP is potentially applicable to a large number of genotyped animals without compromising predictive ability.

2Flux growth and characterization of Ce-substituted Nd 2 Fe 14 B single crystals

DOE PAGES

Susner, Michael A.; Conner, Benjamin S.; Saparov, Bayrammurad I.; ...

2016-10-27

Single crystals of (Nd 1-xCe x) 2Fe 14B are grown out of Fe-(Nd,Ce) flux. Chemical and structural analysis of the crystals indicate that (Nd 1-xCe x) 2Fe 14B forms a solid solution until at least x = 0.38 with a Vegard-like variation of the lattice constants with x. Refinements of single crystal neutron diffraction data indicate that Ce has a slight site preference (7:3) for the 4g rare earth site over the 4f site. Magnetization measurements at 300 K show only small decreases with increasing Ce content in saturation magnetization (M s) and anisotropy field (H A), and Curie temperaturemore » (T C). First principles calculations are carried out to understand the effect of Ce substitution on the electronic and magnetic properties. For a multitude of applications, it is expected that the advantage of incorporating lower-cost and more abundant Ce will outweigh the small adverse effects on magnetic properties. In conclusion, Ce-substituted Nd 2Fe 14B is therefore a potential high-performance permanent magnet material with substantially reduced Nd content.« less

[Effect of Ce3+ on volatile fatty acid concentrations during anaerobic granular sludge digestion].

PubMed

Liang, Rui; Xia, Qing; Ding, Li-Li; Shi, Xiao-Lei; Zhao, Ming-Yu; Ren, Hong-Qiang

2009-04-15

Batch experiments were conducted to investigate the effect of Ce3+ on volatile fatty acid(VFA) concentrations by anaerobic granular sludge digestion using D-Glucose and acetic sodium as substrate in the state of stabilization and restart-up. Results show that when the concentration of Ce3+ is lower than 1 mg/L, VFA concentration decreases, which suggests the transformation of butyric acid to acetic acid and acetic acid to methane is promoted. When the concentration of Ce3+ is 1-10 mg/L, the bacterial activity decreases and decomposition of the acetic acid and butyric acid becomes more difficult compared with the control. Adding Ce3+ brings little change in the constitution of VFA: 96% of VFA is acetic acid and butyric acid, while the propionic acid accounts for less than 3%. With the acetic sodium as the sole carbon and energy source, adding 0.05 mg/L Ce3+ could accelerate acetate degradation. After being conserved for 4 months, the activity of the Ce-containing anaerobic granular sludge is higher than that of the Ce-free sludge. The present of Ce contributes to the restart-up of anaerobic reactors.

The effect of intrauterine infusion of dextrose on clinical endometritis cure rate and reproductive performance of dairy cows.

PubMed

Machado, V S; Oikonomou, G; Ganda, E K; Stephens, L; Milhomem, M; Freitas, G L; Zinicola, M; Pearson, J; Wieland, M; Guard, C; Gilbert, R O; Bicalho, R C

2015-06-01

The main objective of this study was to evaluate the intrauterine administration use of 200 mL of 50% dextrose solution as a treatment against clinical endometritis (CE); CE cure rate and reproductive performance were evaluated. Additionally, the association of several relevant risk factors, such as retained placenta (RP), metritis, CE, anovulation, hyperketonemia, and body condition score with reproductive performance, early embryonic mortality, and CE were evaluated. A total of 1,313 Holstein cows housed on 4 commercial dairy farms were enrolled in the study. At 7±3 DIM cows were examined for metritis and had blood collected to determine serum β-hydroxybutyrate concentration. To determine if cows had ovulated at least once before 44±3 DIM, the presence of a corpus luteum was evaluated by ovarian ultrasonography at 30±3 DIM and at 44±3 DIM. At 30±3 DIM, CE was diagnosed using the Metricheck device (SimcroTech, Hamilton, New Zealand); cows with purulent or mucopurulent vaginal discharge were diagnosed as having CE. Cows diagnosed with CE (n=175) were randomly allocated into 2 treatment groups: treatment (intrauterine infusion of 200 mL of 50% dextrose) or control (no infusion). Clinical endometritis cows were re-evaluated as described above at 44±3 DIM, and cows that were free of purulent or mucopurulent vaginal discharge were considered cured. Intrauterine infusion of dextrose tended to have a detrimental effect on CE cure rate, and treatment did not have an effect on first-service conception rate and early embryonic mortality. A multivariable Cox's proportional hazard model was performed to evaluate the effect of several variables on reproductive performance; the variables RP, CE, parity, anovulation, and the interaction term between parity and anovulation were associated with hazard of pregnancy. Cows that did not have RP or CE were more likely to conceive than cows that were diagnosed with RP or CE. Cows that had RP were at 3.36 times higher odds of losing their pregnancy than cows that did not have RP. In addition, cows diagnosed with CE were at 2.16 higher odds of losing their pregnancy than cows without CE. In conclusion, intrauterine infusion of 200 mL of 50% dextrose solution as a treatment for CE had a strong statistical tendency to decrease CE cure rate, did not improve first-service conception rate and early embryonic mortality, and did not decrease calving-to-conception interval. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Electronic Continuing Education in the Health Professions: An Update on Evidence from RCTs

ERIC Educational Resources Information Center

Lam-Antoniades, Margarita; Ratnapalan, Savithiri; Tait, Gordon

2009-01-01

Introduction: Demonstrating the effectiveness of the rapidly expanding field of electronic continuing education (e-CE) has important implications for CE in the health professions. This study provides an update on evidence from randomized controlled trials (RCTs) assessing the effectiveness of e-CE in the health professions. Methods: A literature…

Evolution of quantum criticality in CeNi(9-x)Cu(x)Ge(4).

PubMed

Peyker, L; Gold, C; Scheidt, E-W; Scherer, W; Donath, J G; Gegenwart, P; Mayr, F; Unruh, T; Eyert, V; Bauer, E; Michor, H

2009-06-10

Crystal structure, specific heat, thermal expansion, magnetic susceptibility and electrical resistivity studies of the heavy fermion system CeNi(9-x)Cu(x)Ge(4) (0≤x≤1) reveal a continuous tuning of the ground state by Ni/Cu substitution from an effectively fourfold-degenerate non-magnetic Kondo ground state of CeNi(9)Ge(4) (with pronounced non-Fermi-liquid features) towards a magnetically ordered, effectively twofold-degenerate ground state in CeNi(8)CuGe(4) with T(N) = 175 ± 5 mK. Quantum critical behavior, [Formula: see text], is observed for [Formula: see text]. Hitherto, CeNi(9-x)Cu(x)Ge(4) represents the first system where a substitution-driven quantum phase transition is connected not only with changes of the relative strength of the Kondo effect and RKKY interaction, but also with a reduction of the effective crystal field ground state degeneracy.

Effect of CeO₂ on Microstructure and Wear Resistance of TiC Bioinert Coatings on Ti6Al4V Alloy by Laser Cladding.

PubMed

Chen, Tao; Liu, Defu; Wu, Fan; Wang, Haojun

2017-12-31

To solve the lack of wear resistance of titanium alloys for use in biological applications, various prepared coatings on titanium alloys are often used as wear-resistant materials. In this paper, TiC bioinert coatings were fabricated on Ti6Al4V by laser cladding using mixed TiC and ZrO₂ powders as the basic pre-placed materials. A certain amount of CeO₂ powder was also added to the pre-placed powders to further improve the properties of the TiC coatings. The effects of CeO₂ additive on the phase constituents, microstructures and wear resistance of the TiC coatings were researched in detail. Although the effect of CeO₂ on the phase constituents of the coatings was slight, it had a significant effect on the microstructure and wear resistance of the coatings. The crystalline grains in the TiC coatings, observed by a scanning electron microscope (SEM), were refined due to the effect of the CeO₂. With the increase of CeO₂ additive content in the pre-placed powders, finer and more compact dendrites led to improvement of the micro-hardness and wear resistance of the TiC coatings. Also, 5 wt % content of CeO₂ additive in the pre-placed powders was the best choice for improving the wear properties of the TiC coatings.

The effect of Ce3+ concentration and heat treatment on the luminescence efficiency of YAG phosphor

NASA Astrophysics Data System (ADS)

Valiev, Damir; Han, Tao; Vaganov, Vitaly; Stepanov, Sergey

2018-05-01

Y3Al5O12 (YAG) phosphor powders doped with Ce3+ at different concentrations (YAG:xCe, x = 0.02, 0.04, 0.06, 0.08, 0.1 wt%) were synthesized by the solid-state reaction method with the addition of BaF2 flux. The effects of cerium concentration and heat treatment on the luminescence efficiency of the YAG:Ce3+ phosphor were investigated. The introduction of Ce3+ ions leads to an increase in luminescent intensity of the YAG phosphor at 560 nm. The band at 530 nm is attributed to Ce3+ ions (optical transitions from the 4f-5d excited state). We assumed that such an increase in the luminescent intensity is due to the ability of Ce3+ to act as a luminescence sensitizer of intrinsic defects in YAG phosphor. The analysis of luminescence decay kinetics in the investigated samples has shown that the decay time in all samples does not differ significantly and equals τ ≈ 60 ± 3 ns. We showed experimentally that increasing the luminescence intensity has an effect observed with relatively low temperature treatment (T = 400 K). The nature of possible luminescence centers and the effect of low heat treatment on the luminescence properties of the powders are discussed.

Correlations between impairment, psychological distress, disability, and quality of life in peripheral facial palsy.

PubMed

Díaz-Aristizabal, U; Valdés-Vilches, M; Fernández-Ferreras, T R; Calero-Muñoz, E; Bienzobas-Allué, E; Moracén-Naranjo, T

2017-05-23

This paper analyses the correlations between scores on scales assessing impairment, psychological distress, disability, and quality of life in patients with peripheral facial palsy (PFP). We conducted a retrospective cross-sectional study including 30 patients in whom PFP had not resolved completely. We used tools for assessing impairment (Sunnybrook Facial Grading System [FGS]), psychological distress (Hospital Anxiety and Depression Scale [HADS]), disability (Facial Disability Index [FDI]), and quality of life (Facial Clinimetric Evaluation [FaCE] scale). We found no correlations between FGS and HADS scores, or between FGS and FDI social function scores. However, we did find a correlation between FGS and FDI physical function scores (r=0.54; P<.01), FDI total score (r=0.4; P<.05), FaCE total scores (ρ=0.66; P<.01), and FaCE social function scores (ρ=0.5; P<.01). We also observed a correlation between HADS Anxiety scores and FDI physical function (r=-0.47; P<.01), FDI social function (r=-0.47; P<.01), FDI total (r=-0.55; P<.01), FaCE total (ρ=-0.49; P<.01), and FaCE social scores (ρ=-0.46; P<.05). Significant correlations were also found between HADS Depression scores and FDI physical function (r=-0.61; P<.01), FDI social function (r=-0.53; P<.01), FDI total (r=-0.66; P<.01), FaCE total (ρ=-0.67; P<.01), and FaCE social scores (ρ=-0.68; P<.01), between FDI physical function scores and FaCE total scores (ρ=0.87; P<.01) and FaCE social function (ρ=0.74; P<.01), between FDI social function and FaCE total (ρ=0.66; P<.01) and FaCE social function scores (ρ=0.72; P<.01), and between FDI total scores and FaCE total (ρ = 0,87; P<.01) and FaCE social function scores (ρ=0.84; P<.01). In our sample, patients with more severe impairment displayed greater physical and global disability and poorer quality of life without significantly higher levels of social disability and psychological distress. Patients with more disability experienced greater psychological distress and had a poorer quality of life. Lastly, patients with more psychological distress also had a poorer quality of life. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

A Contralateral Esophagus-Sparing Technique to Limit Severe Esophagitis Associated With Concurrent High-Dose Radiation and Chemotherapy in Patients With Thoracic Malignancies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Halabi, Hani; Paetzold, Peter; Sharp, Gregory C.

2015-07-15

Purpose: Severe (Radiation Therapy Oncology Group [RTOG] grade 3 or greater) esophagitis generally occurs in 15% to 25% of non–small cell lung cancer (NSCLC) patients undergoing concurrent chemotherapy and radiation therapy (CCRT), which may result in treatment breaks that compromise local tumor control and pose a barrier to dose escalation. Here, we report a novel contralateral esophagus-sparing technique (CEST) that uses intensity modulated radiation therapy (IMRT) to reduce the incidence of severe esophagitis. Methods and Materials: We reviewed consecutive patients with thoracic malignancies undergoing curative CCRT in whom CEST was used. The esophageal wall contralateral (CE) to the tumor wasmore » contoured as an avoidance structure, and IMRT was used to guide a rapid dose falloff gradient beyond the target volume in close proximity to the esophagus. Esophagitis was recorded based on the RTOG acute toxicity grading system. Results: We identified 20 consecutive patients treated with CCRT of at least 63 Gy in whom there was gross tumor within 1 cm of the esophagus. The median radiation dose was 70.2 Gy (range, 63-72.15 Gy). In all patients, ≥99% of the planning and internal target volumes was covered by ≥90% and 100% of prescription dose, respectively. Strikingly, no patient experienced grade ≥3 esophagitis (95% confidence limits, 0%-16%) despite the high total doses delivered. The median maximum dose, V45, and V55 of the CE were 60.7 Gy, 2.1 cc, and 0.4 cc, respectively, indicating effective esophagus cross-section sparing by CEST. Conclusion: We report a simple yet effective method to avoid exposing the entire esophagus cross-section to high doses. By using proposed CE dose constraints of V45 <2.5 cc and V55 <0.5 cc, CEST may improve the esophagus toxicity profile in thoracic cancer patients receiving CCRT even at doses above the standard 60- to 63-Gy levels. Prospective testing of CEST is warranted.« less

Parameter optimization for constructing competing endogenous RNA regulatory network in glioblastoma multiforme and other cancers.

PubMed

Chiu, Yu-Chiao; Hsiao, Tzu-Hung; Chen, Yidong; Chuang, Eric Y

2015-01-01

In addition to direct targeting and repressing mRNAs, recent studies reported that microRNAs (miRNAs) can bridge up an alternative layer of post-transcriptional gene regulatory networks. The competing endogenous RNA (ceRNA) regulation depicts the scenario where pairs of genes (ceRNAs) sharing, fully or partially, common binding miRNAs (miRNA program) can establish coexpression through competition for a limited pool of the miRNA program. While the dynamics of ceRNA regulation among cellular conditions have been verified based on in silico and in vitro experiments, comprehensive investigation into the strength of ceRNA regulation in human datasets remains largely unexplored. Furthermore, pan-cancer analysis of ceRNA regulation, to our knowledge, has not been systematically investigated. In the present study we explored optimal conditions for ceRNA regulation, investigated functions governed by ceRNA regulation, and evaluated pan-cancer effects. We started by investigating how essential factors, such as the size of miRNA programs, the number of miRNA program binding sites, and expression levels of miRNA programs and ceRNAs affect the ceRNA regulation capacity in tumors derived from glioblastoma multiforme patients captured by The Cancer Genome Atlas (TCGA). We demonstrated that increased numbers of common targeting miRNAs as well as the abundance of binding sites enhance ceRNA regulation and strengthen coexpression of ceRNA pairs. Also, our investigation revealed that the strength of ceRNA regulation is dependent on expression levels of both miRNA programs and ceRNAs. Through functional annotation analysis, our results indicated that ceRNA regulation is highly associated with essential cellular functions and diseases including cancer. Furthermore, the highly intertwined ceRNA regulatory relationship enables constitutive and effective intra-function regulation of genes in diverse types of cancer. Using gene and microRNA expression datasets from TCGA, we successfully quantified the optimal conditions for ceRNA regulation, which hinge on four essential parameters of ceRNAs. Our analysis suggests optimized ceRNA regulation is related to disease pathways and essential cellular functions. Furthermore, although the strength of ceRNA regulation is dynamic among cancers, its governing functions are stably maintained. The findings of this report contribute to better understanding of ceRNA dynamics and its crucial roles in cancers.

Trivalent cerium coped crystals as tunable laser systems: two bad apples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamilton, D.S.

1985-01-01

The 5d-4f transitions of trivalent doped crystals have broad emission bands with large oscillator strengths and near unity quantum efficiency. These characteristics make cerium systems strong candidates for tunable solid state lasers. However, two such cerium crystals will probably never lase. The first is Ce/sup 3 +/:YAG where a strong excited state absorption quenches the lasing transition. Our recent measurements have indicated that the excited state absorption terminates in the YAG conduction band with a peak cross section of 1.0 x 10/sup -17/ cm/sup 2/ at 700 nm. Some of the general features of impurity ion to band spectra aremore » discussed. The second system is Ce/sup 3 +/:CaF/sub 2/ where a uv pump induced photochromic center is produced following excitation of the cerium ions. The initial measurements of cerium related transient absorptions in Ce/sup 3 +/:YLF are also presented.« less

RHCE*ceCF encodes partial c and partial e but not CELO an antigen antithetical to Crawford

PubMed Central

Hipsky, Christine Halter; Lomas-Francis, Christine; Fuchisawa, Akiko; Reid, Marion E.; Moulds, Marilyn; Christensen, JoAnn; Nickle, Pam; Vege, Sunitha; Westhoff, Connie

2010-01-01

Background RH43 (Crawford) is encoded by RHCE*ce with nucleotide changes 48G>C, 697C>G, and 733C>G (RHCE*ceCF). We investigated the Rh antigen expression and antibody specificities in four patients with this allele. Methods Hemagglutination tests, DNA extraction, PCR-RFLP, AS-PCR, reticulocyte RNA isolation, RT-PCR cDNA analyses, cloning, and sequencing were performed by standard procedures. Results RBCs from two patients typed D+C−E−c+e+/−, hrS−/+W, hrB− and their serum was reactive (3+) with all RBC samples of common Rh phenotype tested, but non reactive with Rhnull or D- - RBCs (apparent alloanti-Rh17). At the RHCE locus, Patient 1 was homozygous for RHCE*ceCF, and Patient 2 inherited RHCE*ceCF in trans to a silenced RHCE*cE. Cross testing of serum and RBCs from these two samples showed mutual compatibility, indicating that both antibodies define the same novel high prevalence antigen on Rhce. Two additional patients, one whose serum contained alloanti-c but the RBCs typed C+c+, and one whose serum contained anti-e but the RBCs typed E+e+, also had RHCE*ceCF. RHCE*Ce was present in trans in the former and RHCE*cE in the latter patient. Conclusion We report that amino acid changes on RhceCF (Trp16Cys, Gln233Glu, and Leu245Val) alter the protein to the extent that c and e antigens are partial, and a high prevalence antigen, we have named CELO (provisional ISBT number 004058; RH58) is not expressed. CELO is antithetical to RH43 (Crawford). PMID:20609196

The Use of a Binary Composite Endpoint and Sample Size Requirement: Influence of Endpoints Overlap.

PubMed

Marsal, Josep-Ramon; Ferreira-González, Ignacio; Bertran, Sandra; Ribera, Aida; Permanyer-Miralda, Gaietà; García-Dorado, David; Gómez, Guadalupe

2017-05-01

Although composite endpoints (CE) are common in clinical trials, the impact of the relationship between the components of a binary CE on the sample size requirement (SSR) has not been addressed. We performed a computational study considering 2 treatments and a CE with 2 components: the relevant endpoint (RE) and the additional endpoint (AE). We assessed the strength of the components' interrelation by the degree of relative overlap between them, which was stratified into 5 groups. Within each stratum, SSR was computed for multiple scenarios by varying the events proportion and the effect of the therapy. A lower SSR using CE was defined as the best scenario for using the CE. In 25 of 66 scenarios the degree of relative overlap determined the benefit of using CE instead of the RE. Adding an AE with greater effect than the RE leads to lower SSR using the CE regardless of the AE proportion and the relative overlap. The influence of overlapping decreases when the effect on RE increases. Adding an AE with lower effect than the RE constitutes the most uncertain situation. In summary, the interrelationship between CE components, assessed by the relative overlap, can help to define the SSR in specific situations and it should be considered for SSR computation. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Cross-cultural reliability and validity of ADHD assessed by the ADHD Rating Scale in a pan-European study.

PubMed

Döpfner, Manfred; Steinhausen, Hans-Christoph; Coghill, David; Dalsgaard, Søren; Poole, Lynne; Ralston, Stephen J; Rothenberger, Aribert

2006-12-01

To provide psychometric information on the Attention-Deficit/Hyperactivity Disorder (ADHD) Rating Scale-IV (ADHD-RS-IV) in a large population of children with ADHD. Patients aged 6-18 years (n=1,478 in baseline analysis) were rated by 244 physicians on the ADHD-RS-IV based on a semi-structured interview with the patient's parent. Physicians additionally rated functional impairment (CGAS) and health status (CGI-S), and parents rated their child's behavioural and emotional problems (SDQ) and quality of life (CHIP-CE). Inattention and hyperactivity-impulsivity as dimensions of ADHD were replicated. 3-factor solutions reflecting the ICD-10 definition, with hyperactivity, impulsivity and inattention as separate dimensions were extracted in some national sub-samples and in separate analyses for boys and younger children.Good internal consistencies, strong country effects and small effects of age were found. Based on ADHD-RS-IV, 88.5% of patients met the criteria for any ADHD diagnosis. Correlations between ADHD-RS-IV and measures of functional impairment were low but statistically significant. The correlations with SDQ and CHIP-CE scales confirm the convergent and divergent validity of ADHD-RS-IV. Impressive evidence for the cross-cultural factorial validity, internal consistency as well as convergent and divergent validity of ADHD-RS-IV was found. ADHD can be assessed reliably and validly in routine care across Europe. The ICD-10 3-factor model seems to be less robust than the DSM-IV 2-factor model, but may be a good description for special populations (boys, younger children).

In vitro study of the effects of ultrasound-mediated glycerol on optical attenuation of human normal and cancerous esophageal tissues with optical coherence tomography

NASA Astrophysics Data System (ADS)

Zhang, Y. Q.; Wei, H. J.; Yang, H. Q.; Guo, Z. Y.; Xie, S. S.; Gu, H. M.; Guo, X.; Zhu, Z. G.

2013-06-01

Previous studies from our group have demonstrated that glucose solution can induce optical clearing enhancement of esophageal tissues with optical coherence tomography (OCT). The aims of this study were to evaluate the optical clearing effects of ultrasound-mediated optical clearing agents (OCAs) and to find more effective methods to distinguish human normal esophageal tissues (NE) and cancerous esophageal tissues (CE). Here we used the OCT technique to investigate the optical attenuation of NE and CE in vitro after treatment with 30% glycerol alone and glycerol combined with ultrasound, respectively. Experimental results showed that the averaged attenuation coefficient of CE was significantly larger than that of NE. The maximal decreases of averaged attenuation coefficients of NE and CE were approximately 48.7% and 36.2% after treatment with 30% glycerol alone, and they were significantly lower than those treated with 30% glycerol and ultrasound (57.5% in NE and 44.8% in CE). Moreover, after treatment with 30% glycerol alone, the averaged attenuation coefficients of NE and CE reached their minima in about 80 min and 65 min, respectively. The times were much shorter in NE and CE after treatment with glycerol with ultrasound, being about 62 min and 50 min, respectively. The results suggest that there is a significant difference in the optical properties of NE and CE, and that OCT with an ultrasound-OCAs combination has the ability to distinguish CE from NE.

Intergenerational responses of wheat (Triticum aestivum L.) to cerium oxide nanoparticles exposure

DOE PAGES

Rico, Cyren M.; Johnson, Mark G.; Marcus, Matthew A.; ...

2017-02-06

The intergenerational impact of engineered nanomaterials in plants is a major knowledge gap in the literature. A soil microcosm study was performed to assess the effects of multi-generational exposure of wheat (Triticum aestivum L.) to cerium oxide nanoparticles (CeO 2 -NPs). Seeds from plants that were exposed to 0, 125, and 500 mg CeO 2-NPs kg -1 soil (Ce-0, Ce-125 or Ce-500, respectively) in first generation (S1) were cultivated in factorial combinations of Ce-0, Ce-125 or Ce-500 to produce second generation (S2) plants. The factorial combinations for first/second generation treatments in Ce-125 were S1-Ce-0/S2-Ce-0, S1-Ce-0/S2-Ce-125, S1-Ce-125/S2-Ce-0 and S1-Ce-125/S2-Ce-125, and inmore » Ce-500 were S1-Ce-0/S2-Ce-0, S1-Ce-0/S2-Ce-500, S1-Ce-500/S2-Ce-0 and S1-Ce-500/S2-Ce-500. Agronomic, elemental, isotopic, and synchrotron X-ray fluorescence (XRF) and X-ray absorption near-edge spectroscopy (XANES) data were collected on second generation plants. Results showed that plants treated during the first generation only with either Ce-125 or Ce-500 (e.g. S1-Ce-125/S2-Ce-0 or S1-Ce-500/S2-Ce-0) had reduced accumulation of Ce (61 or 50%), Fe (49 or 58%) and Mn (34 or 41%) in roots, and δ 15 N (11 or 8%) in grains compared to the plants not treated in both generations (i.e. S1-Ce-0/S2-Ce-0). Plants treated in both generations with Ce-125 (i.e. S1-Ce-125/S2-Ce-125) produced grains that had lower Mn, Ca, K, Mg and P relative to plants treated in the second generation only (i.e. S1-Ce-0/S2-Ce-125). In addition, synchrotron XRF elemental chemistry maps of soil/plant thin-sections revealed limited transformation of CeO 2-NPs with no evidence of plant uptake or accumulation. The findings demonstrated that first generation exposure of wheat to CeO 2-NPs affects the physiology and nutrient profile of the second generation plants. However, the lack of concentration-dependent responses indicate that complex physiological processes are involved which alter uptake and metabolism of CeO 2-NPs in wheat.« less

Intergenerational responses of wheat (Triticum aestivum L.) to cerium oxide nanoparticles exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rico, Cyren M.; Johnson, Mark G.; Marcus, Matthew A.

The intergenerational impact of engineered nanomaterials in plants is a major knowledge gap in the literature. A soil microcosm study was performed to assess the effects of multi-generational exposure of wheat (Triticum aestivum L.) to cerium oxide nanoparticles (CeO 2 -NPs). Seeds from plants that were exposed to 0, 125, and 500 mg CeO 2-NPs kg -1 soil (Ce-0, Ce-125 or Ce-500, respectively) in first generation (S1) were cultivated in factorial combinations of Ce-0, Ce-125 or Ce-500 to produce second generation (S2) plants. The factorial combinations for first/second generation treatments in Ce-125 were S1-Ce-0/S2-Ce-0, S1-Ce-0/S2-Ce-125, S1-Ce-125/S2-Ce-0 and S1-Ce-125/S2-Ce-125, and inmore » Ce-500 were S1-Ce-0/S2-Ce-0, S1-Ce-0/S2-Ce-500, S1-Ce-500/S2-Ce-0 and S1-Ce-500/S2-Ce-500. Agronomic, elemental, isotopic, and synchrotron X-ray fluorescence (XRF) and X-ray absorption near-edge spectroscopy (XANES) data were collected on second generation plants. Results showed that plants treated during the first generation only with either Ce-125 or Ce-500 (e.g. S1-Ce-125/S2-Ce-0 or S1-Ce-500/S2-Ce-0) had reduced accumulation of Ce (61 or 50%), Fe (49 or 58%) and Mn (34 or 41%) in roots, and δ 15 N (11 or 8%) in grains compared to the plants not treated in both generations (i.e. S1-Ce-0/S2-Ce-0). Plants treated in both generations with Ce-125 (i.e. S1-Ce-125/S2-Ce-125) produced grains that had lower Mn, Ca, K, Mg and P relative to plants treated in the second generation only (i.e. S1-Ce-0/S2-Ce-125). In addition, synchrotron XRF elemental chemistry maps of soil/plant thin-sections revealed limited transformation of CeO 2-NPs with no evidence of plant uptake or accumulation. The findings demonstrated that first generation exposure of wheat to CeO 2-NPs affects the physiology and nutrient profile of the second generation plants. However, the lack of concentration-dependent responses indicate that complex physiological processes are involved which alter uptake and metabolism of CeO 2-NPs in wheat.« less

CE-MRA for follow-up of aneurysms post stent-assisted coiling.

PubMed

Agid, R; Schaaf, M; Farb, Ri

2012-09-01

This study compared the accuracy of contrast-enhanced MR angiography (CE-MRA) to intra-arterial cerebral angiography (IA-DSA) for assessment of intracranial aneurysms after stent-assisted coiling and to check if the presence of a stent in the parent artery diminishes the accuracy of CE-MRA. Consecutive patients with cerebral aneurysms treated by stent-assisted coiling were evaluated retrospectively. Matching follow-up CE-MRA and IA-DSA were evaluated separately. Evaluation included the presence of aneurysmal remnant, patency and stenosis of parent artery. Twenty-seven patients with 28 aneurysms and 33 matched CE-MRA and IA-DSA studies were evaluated. Nineteen aneurysmal remnants were seen on CE-MRA and 16 on IA-DSA. CE-MRA diagnosed three aneurysmal remnants not appreciated on IA-DSA. Five other remnants were larger on CE-MRA than IA-DSA. None of the remnants were missed on CE-MRA. Parent arteries were patent on both modalities. CE-MRA showed false stenosis of the stented artery in six cases and exaggerated stenosis in two. In 18 cases, CE-MRA showed a short focal "pseudo-stenosis" where the stent's marker bands were located. This was noted whenever the stent's marker bands were located in an artery with luminal diameter ≤2 mm and was called "marker band effect". CE-MRA is an accurate technique for follow-up of aneurysms post stent-assisted coiling with excellent depiction of remnants in spite of the presence of a stent. Apparent stenosis of the stented parent artery on CE-MRA is often false or exaggerated. "Marker band effect" should be recognized as an artifact that appears when stent's marker bands are in a small artery.

Fe-doping effects on the structural, vibrational, magnetic, and electronic properties of ceria nanoparticles

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.

Li+, Na+ and K+ co-doping effects on scintillation properties of Ce:Gd3Ga3Al2O12 single crystals

NASA Astrophysics Data System (ADS)

Yoshino, Masao; Kamada, Kei; Kochurikhin, Vladimir V.; Ivanov, Mikhail; Nikl, Martin; Okumura, Satoshi; Yamamoto, Seiichi; Yeom, Jung Yeol; Shoji, Yasuhiro; Kurosawa, Shunsuke; Yokota, Yuui; Ohashi, Yuji; Yoshikawa, Akira

2018-06-01

Ce0.5%: Ce:Gd3Ga3Al2O12(GGAG) single crystals co-doped with 500at.ppm Li+, Na+ and K+ were grown by using the micro-pulling down method. The smooth Ce4+ charge transfer absorption below 350 nm and decay time acceleration were observed in Li co-doped sample. Na+ and K+ co-doping did not show a large effect on the acceleration of decay time compared with Li co-doping. Ce0.5%:GGAG single crystals co-doped with 500 at.ppm Li+ were also grown by the Czochralski method. Optical, scintillation properties and timing performance were evaluated to investigate the effect of univalent alkali metal ions co-doping on Ce:GGAG scintillators. The scintillation decay curves were accelerated by Li co-doping: the decay time was significantly accelerated to 54.8 ns (47%) for the faster component and 158 ns (53%) for the slower component. The light output was 94% of the non co-doped Ce:GGAG standard. The coincidence time resolution was improved to 258 ps by Li co-doping.

Ce3+-ion, Surface Oxygen Vacancy, and Visible Light-induced Photocatalytic Dye Degradation and Photocapacitive Performance of CeO2-Graphene Nanostructures.

PubMed

Khan, Mohammad Ehtisham; Khan, Mohammad Mansoob; Cho, Moo Hwan

2017-07-19

Cerium oxide nanoparticles (CeO 2 NPs) were fabricated and grown on graphene sheets using a facile, low cost hydrothermal approach and subsequently characterized using different standard characterization techniques. X-ray photoelectron spectroscopy and electron paramagnetic resonance revealed the changes in surface states, composition, changes in Ce 4+ to Ce 3+ ratio, and other defects. Transmission electron microscopy (TEM) and high resolution TEM revealed that the fabricated CeO 2 NPs to be spherical with particle size of ~10-12 nm. Combination of defects in CeO 2 NPs with optimal amount of two-dimensional graphene sheets had a significant effect on the properties of the resulting hybrid CeO 2 -Graphene nanostructures, such as improved optical, photocatalytic, and photocapacitive performance. The excellent photocatalytic degradation performances were examined by monitoring their ability to degrade Congo red ~94.5% and methylene blue dye ~98% under visible light irradiation. The photoelectrode performance had a maximum photocapacitance of 177.54 Fg -1 and exhibited regular capacitive behavior. Therefore, the Ce 3+ -ion, surface-oxygen-vacancies, and defects-induced behavior can be attributed to the suppression of the recombination of photo-generated electron-hole pairs due to the rapid charge transfer between the CeO 2 NPs and graphene sheets. These findings will have a profound effect on the use of CeO 2 -Graphene nanostructures for future energy and environment-related applications.

CeLa enhanced corrosion resistance of Al-Cu-Mn-Mg-Fe alloy for lithium battery shell

NASA Astrophysics Data System (ADS)

Du, Jiandi; Ding, Dongyan; Zhang, Wenlong; Xu, Zhou; Gao, Yongjin; Chen, Guozhen; Chen, Weigao; You, Xiaohua; Chen, Renzong; Huang, Yuanwei; Tang, Jinsong

2017-11-01

Effects of CeLa addition on the localized corrosion and electrochemical corrosion behavior of Al-Cu-Mn-Mg-Fe lithium battery shell alloy were investigated by immersion testing and electrochemical testing in 0.6 M NaCl solution at different temperatures. Experimental results indicated that CeLa addition resulted in the formation of AlCuCe/La (Al8Cu4Ce and Al6Cu6La) local cathodes and corrosion activity of the main intermetallic particles decreased in the order of Al2CuMg, AlCuCe/La, Al6(Mn, Fe). Corrosion potential shifted positively due to CeLa alloying. Corrosion current density of the CeLa-containing alloy was lower than that of the CeLa-free alloy at room temperature. At room temperature, there was no obvious surface passivation for both alloys. At 80 °C CeLa addition resulted in a wide passive region at the anode polarization region. Electrochemical impedance spectroscopy (EIS) analysis also indicated that corrosion resistance of the CeLa-containing alloy was much higher than that of the CeLa-free alloy.

Determination of Conjugation Efficiency of Antibodies and Proteins to the Superparamagnetic Iron Oxide Nanoparticles by Capillary Electrophoresis with Laser-Induced Fluorescence Detection

NASA Astrophysics Data System (ADS)

Wang, Fu-Hua; Yoshitake, Takashi; Kim, Do-Kyung; Muhammed, Mamoun; Bjelke, Börje; Kehr, Jan

2003-04-01

The method based on capillary electrophoresis with laser-induced fluorescence detection (CE/LIF) was developed for determination of magnetic iron oxide nanoparticles (hydrodynamic diameters of 100 nm) functionalized with molecules containing primary amino groups. The magnetic nanoparticles with carboxylic or aminopropyl-trimethoxysilane groups at their surface were conjugated to the model proteins (bovine serum albumin, BSA; streptavidin or goat anti-rabbit immunoglobulin G, IgG) using carbodiimide as a zero-length cross-linker. The nanoparticle-protein conjugates (hydrodynamic diameter 163-194 nm) were derivatized with naphthalene-2,3-dicarboxaldehyde reagent and separated by CE/LIF with a helium-cadmium laser (excitation at 442 nm, emission at 488 nm). The separations were carried out by using a fused-silica capillary (effective length 48 cm, inner diameter 75 um) and 100 mM sodium borate buffer (pH 9.2), the potential was 30 kV. The detection limit for BSA-conjugate was 1.3 pg/10 nl, i.e. about 20 amol. The present method provides an efficient and fast tool for sensitive determination of the efficacy of biomolecular functionalization of magnetic nanoparticles. The CE/LIF technique requires only negligible sample volumes for analysis, which is especially suitable for controlling the process of preparation of functionalized nanoparticles with unique properties aimed to be used for diagnostic or therapeutic purposes.

Ground truth seismic events and location capability at Degelen mountain, Kazakhstan

NASA Astrophysics Data System (ADS)

Trabant, Chad; Thurber, Clifford; Leith, William

2002-07-01

We utilized nuclear explosions from the Degelen Mountain sub-region of the Semipalatinsk Test Site (STS), Kazakhstan, to assess seismic location capability directly. Excellent ground truth information for these events was either known or was estimated from maps of the Degelen Mountain adit complex. Origin times were refined for events for which absolute origin time information was unknown using catalog arrival times, our ground truth location estimates, and a time baseline provided by fixing known origin times during a joint hypocenter determination (JHD). Precise arrival time picks were determined using a waveform cross-correlation process applied to the available digital data. These data were used in a JHD analysis. We found that very accurate locations were possible when high precision, waveform cross-correlation arrival times were combined with JHD. Relocation with our full digital data set resulted in a mean mislocation of 2 km and a mean 95% confidence ellipse (CE) area of 6.6 km 2 (90% CE: 5.1 km 2), however, only 5 of the 18 computed error ellipses actually covered the associated ground truth location estimate. To test a more realistic nuclear test monitoring scenario, we applied our JHD analysis to a set of seven events (one fixed) using data only from seismic stations within 40° epicentral distance. Relocation with these data resulted in a mean mislocation of 7.4 km, with four of the 95% error ellipses covering less than 570 km 2 (90% CE: 438 km 2), and the other two covering 1730 and 8869 km 2 (90% CE: 1331 and 6822 km 2). Location uncertainties calculated using JHD often underestimated the true error, but a circular region with a radius equal to the mislocation covered less than 1000 km 2 for all events having more than three observations.

Luminescent down shifting effect of Ce-doped yttrium aluminum garnet thin films on solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shao, Guojian; Lou, Chaogang; Kang, Jian

2015-12-21

Ce-doped yttrium aluminum garnet (YAG:Ce) thin films as luminescent down shifting (LDS) materials are introduced into the module of crystalline silicon solar cells. The films are deposited by RF magnetron sputtering on the lower surface of the quartz glass. They convert ultraviolet and blue light into yellow light. Experiments show that the introduction of YAG:Ce films improves the conversion efficiency from 18.45% of the cells to 19.27% of the module. The increasing efficiency is attributed to LDS effect of YAG:Ce films and the reduced reflection of short wavelength photons. Two intentionally selected samples with similar reflectivities are used to evaluatemore » roughly the effect of LDS alone on the solar cells, which leads to a relative increase by 2.68% in the conversion efficiency.« less

Effect of carbohydrate and protein solutions consumed during a moderate-intensity exercise on post-exercise appetite.

PubMed

Sun, Feng-Hua; Si, Gang-Yan

2017-10-01

This study aimed to investigate whether co-ingestion of carbohydrate and protein during exercise affect the post-exercise ad libitum food intake. Twelve healthy active male participants (mean±SD, age: 20±1; height: 176±6cm; weight: 63.6±5.3kg; VO 2peak : 51.2±7.1ml/kg/min) completed three main experimental trials in a randomized cross-over design. In each trial, the participants completed 1h of ergometer cycling at 60% VO 2peak , followed by 2h recovery. The participants were required to consume one of three solutions every 15min during exercise: distilled water (DW), carbohydrate-electrolyte solution (CE), and carbohydrate-electrolyte-protein solution (CEP). The energy was matched between the two latter solutions. The CHO-to-protein ratio in CEP was 2:1. At the end of recovery period, participants were provided with pizza lunch ad libitum, and the amount consumed was recorded. Several subjective feelings, appetite scores and blood glucose were determined during the experimental trials. No differences were found in either the amount of consumed pizza (DW vs. CE vs. CEP: 607±128 vs. 592±119 vs. 599±125g, P=0.845) or the appetite score before pizza was consumed (DW vs. CE vs. CEP: 14±9 vs. 12±14 vs. 14±10, P=0.357) among the three trials. The blood glucose concentrations during exercise were higher in the CE and CEP trials than in the DW trial. In conclusion, different solutions consumed during a 1h moderate-intensity exercise in the present study did not affect post-exercise appetite. Copyright © 2017 Elsevier Inc. All rights reserved.

Ce doped NiO nanoparticles as selective NO2 gas sensor

NASA Astrophysics Data System (ADS)

Gawali, Swati R.; Patil, Vithoba L.; Deonikar, Virendrakumar G.; Patil, Santosh S.; Patil, Deepak R.; Patil, Pramod S.; Pant, Jayashree

2018-03-01

Metal oxide gas sensors are promising portable gas detection devices because of their advantages such as low cost, easy production and compact size. The performance of such sensors is strongly dependent on material properties such as morphology, structure and doping. In the present study, we report the effect of cerium (Ce) doping on nickel oxide (NiO) nano-structured thin film sensors towards various gases. Bare NiO and Ce doped NiO nanoparticles (Ce:NiO) were synthesized by sol-gel method. To understand the effect of Ce doping in nickel oxide, various molar percentages of Ce with respect to nickel were incorporated. The structure, phase, morphology and band-gap energy of as-synthesized nanoparticles were studied by XRD, SEM, EDAX and UV-vis spectroscopy. Thin film gas sensors of all the samples were prepared and subjected to various gases such as LPG, NH3, CH3COCH3 and NO2. A systematic and comparative study reveals an enhanced gas sensing performance of Ce:NiO sensors towards NO2 gas. The maximum sensitivity for NO2 gas is around 0.719% per ppm at moderate operating temperature of 150 °C for 0.5% Ce:NiO thin film gas sensor. The enhanced gas sensing performance for Ce:NiO is attributed to the distortion of crystal lattice caused by doping of Ce into NiO.

The development of Ce3+-activated (Gd,Lu)3Al5O12 garnet solid solutions as efficient yellow-emitting phosphors

NASA Astrophysics Data System (ADS)

Li, Jinkai; Li, Ji-Guang; Liu, Shaohong; Li, Xiaodong; Sun, Xudong; Sakka, Yoshio

2013-10-01

Ce3+-activated Gd3Al5O12 garnet, effectively stabilized by Lu3+ doping, has been developed for new yellow-emitting phosphors. The powder processing of [(Gd1-xLux)1-yCey]3Al5O12 solid solutions was achieved through precursor synthesis via carbonate precipitation, followed by annealing. The resultant (Gd,Lu)AG:Ce3+ phosphor particles exhibit typical yellow emission at ˜570 nm (5d-4f transition of Ce3+) upon blue-light excitation at ˜457 nm (the 2F5/2-5d transition of Ce3+). The quenching concentration of Ce3+ was determined to be ˜1.0 at% (y = 0.01) and the quenching mechanism was suggested to be driven by exchange interactions. The best luminescent [(Gd0.9Lu0.1)0.99Ce0.01]AG phosphor is comparative to the well-known YAG:Ce3+ in emission intensity but has a substantially red-shifted emission band that is desired for warm-white lighting. The effects of processing temperature (1000-1500 °C) on the spectroscopic properties of the phosphors, especially those of Lu3+/Ce3+, were thoroughly investigated and discussed from the centroid position and crystal field splitting of the Ce3+ 5d energy levels.

Magnetic properties of Ce xY 1-xPt compared to Ce xLa 1-xPt ones

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ocko, M.; Zadro, K.; Drobac, D.

In this paper, we have investigated the magnetic properties of the Ce xY 1-xPt Kondo ferromagnetic alloy system in the temperature range from 1.8 K to 320 K. The results of these investigations can be summarized as follows: dc-susceptibility can be described by the Curie-Weiss law at higher temperatures down to about 100 K, but also at low temperatures above the ferromagnetic phase transition. At higher temperatures, the extracted Curie-Weiss parameter, θ p, is negative and at low temperature θ C is positive. The extracted effective magnetic moment above 100 K increases with the Ce content up to almost themore » theoretical value of the isolated Ce 3+ ion, μ = 2.54 μ B, for CePt. This suggests an increase of the hybridization with decreasing Ce content, or said equivalently, it means that the increase of the Kondo interaction diminishes effective magnetic moment. These observations confirm the main conclusions inferred from an earlier transport properties investigation of this alloy system. The corresponding θ C differs within 1 K from the Curie temperature, T C, which is determined by the resistivity measurements. The most intriguing result of the investigation of Ce xY 1-xPt is the linear concentration dependence of T C vs. x and, moreover, it is the same as in Ce xLa 1-xPt although in the former system the hybridization diminishes considerably the effective magnetic moment per Ce ion, while in the latter system, hybridization is minor and independent of x. Finally, we offer the explanations of these intriguing experimental results.« less

Magnetic properties of Ce xY 1-xPt compared to Ce xLa 1-xPt ones

DOE PAGES

Ocko, M.; Zadro, K.; Drobac, D.; ...

2017-12-05

In this paper, we have investigated the magnetic properties of the Ce xY 1-xPt Kondo ferromagnetic alloy system in the temperature range from 1.8 K to 320 K. The results of these investigations can be summarized as follows: dc-susceptibility can be described by the Curie-Weiss law at higher temperatures down to about 100 K, but also at low temperatures above the ferromagnetic phase transition. At higher temperatures, the extracted Curie-Weiss parameter, θ p, is negative and at low temperature θ C is positive. The extracted effective magnetic moment above 100 K increases with the Ce content up to almost themore » theoretical value of the isolated Ce 3+ ion, μ = 2.54 μ B, for CePt. This suggests an increase of the hybridization with decreasing Ce content, or said equivalently, it means that the increase of the Kondo interaction diminishes effective magnetic moment. These observations confirm the main conclusions inferred from an earlier transport properties investigation of this alloy system. The corresponding θ C differs within 1 K from the Curie temperature, T C, which is determined by the resistivity measurements. The most intriguing result of the investigation of Ce xY 1-xPt is the linear concentration dependence of T C vs. x and, moreover, it is the same as in Ce xLa 1-xPt although in the former system the hybridization diminishes considerably the effective magnetic moment per Ce ion, while in the latter system, hybridization is minor and independent of x. Finally, we offer the explanations of these intriguing experimental results.« less

The influence of different alkaline earth oxides on the structural and optical properties of undoped, Ce-doped, Sm-doped, and Sm/Ce co-doped lithium alumino-phosphate glasses

NASA Astrophysics Data System (ADS)

Othman, H. A.; Arzumanyan, G. M.; Möncke, D.

2016-12-01

Undoped, singly Sm doped, Ce doped, and Sm/Ce co-doped lithium alumino-phosphate glasses with different alkaline earth modifiers were prepared by melt quenching. The structure of the prepared glasses was investigated by FT-IR and Raman, as well as by optical spectroscopy. The effect of the optical basicity of the host glass matrix on the added active dopants was studied, as was the effect doping had on the phosphate structural units. The optical edge shifts toward higher wavelengths with an increase in the optical basicity due to the increased polarizability of the glass matrix, but also with increasing CeO2 concentration as a result of Ce3+/Ce4+ inter valence charge transfer (IV-CT) absorption. The optical band gap for direct and indirect allowed transitions was calculated for the undoped glasses. The glass sample containing Mg2+ modifier ions is found to have the highest value (4.16 eV) for the optical band gap while Ba2+ has the lowest value (3.61 eV). The change in the optical band gap arises from the structural changes and the overall polarizability (optical basicity). Refractive index, molar refractivity Rm and molar polarizability αm values increase with increasing optical basicity of the glasses. The characteristic absorption peaks of Sm3+ were also investigated. For Sm/Ce co-doped glasses, especially at high concentration of CeO2, the absorption of Ce3+ hinders the high energy absorption of Sm3+ and this effect becomes more obvious with increasing optical basicity.

CeO2 nanoparticles induce no changes in phenanthrene toxicity to the soil organisms Porcellionides pruinosus and Folsomia candida.

PubMed

Tourinho, Paula S; Waalewijn-Kool, Pauline L; Zantkuijl, Irene; Jurkschat, Kerstin; Svendsen, Claus; Soares, Amadeu M V M; Loureiro, Susana; van Gestel, Cornelis A M

2015-03-01

Cerium oxide nanoparticles (CeO2 NPs) are used as diesel fuel additives to catalyze oxidation. Phenanthrene is a major component of diesel exhaust particles and one of the most common pollutants in the environment. This study aimed at determining the effect of CeO2 NPs on the toxicity of phenanthrene in Lufa 2.2 standard soil for the isopod Porcellionides pruinosus and the springtail Folsomia candida. Toxicity tests were performed in the presence of CeO2 concentrations of 10, 100 or 1000mg Ce/kg dry soil and compared with results in the absence of CeO2 NPs. CeO2 NPs had no adverse effects on isopod survival and growth or springtail survival and reproduction. For the isopods, LC50s for the effect of phenanthrene ranged from 110 to 143mg/kg dry soil, and EC50s from 17.6 to 31.6mg/kg dry soil. For the springtails, LC50s ranged between 61.5 and 88.3mg/kg dry soil and EC50s from 52.2 to 76.7mg/kg dry soil. From this study it may be concluded that CeO2 NPs have a low toxicity and do not affect toxicity of phenanthrene to isopods and springtails. Copyright © 2014 Elsevier Inc. All rights reserved.

Comparative study of radical scavenger activities of crude extract and fractions from Cuphea carthagenensis leaves.

PubMed

Schuldt, E Z; Farias, M R; Ribeiro-do-Valle, R M; Ckless, K

2004-09-01

This study investigated the superoxide anion and hydroxyl radical scavenger properties, as well as the inhibition of lipid peroxidation by the crude hydroalcoholic extract (CE) and the butanolic (BF) and ethyl acetate (EAF) fractions of Cuphea carthagenensis leaves. In a enzymatic system of O2- production (xanthine/xanthine oxidase system) the CE, EAF and BF (0.1-100 microg ml(-1)) were effective at inhibiting both uric acid formation and NBT reduction by O2(-1). In the non-enzymatic system of O2- generation, the CE and fractions were effective only at the concentration of 100 microg ml(-1). The CE, EAF and BF were also evaluated for their ability to scavenge hydroxyl radicals and/or to chelate iron. The results showed that CE, BF and EAF from C. carthagenensis (0.1-100 microg ml(-1)) were able to inhibit deoxyribose degradation in a concentration-dependent manner. CE was more potent than the fractions. In a hydrophobic system, increasing concentrations of CE, EAF and BF (0.1-100 microg ml(-1)) caused graded inhibition of lipid peroxidation of rat liver homogenate. The EAF displayed the lowest median inhibitory concentration. The present study suggests that an extract (CE) and fractions (EAF and BF) from C. carthagenensis leaves are significant sources of phenolic compounds with antioxidant activity in vitro and may have important health effects, for example, in cardiovascular disease.

Protective effects of Curcuma longa against neurobehavioral and neurochemical damage caused by cerium chloride in mice.

PubMed

Kadri, Yamina; Nciri, Riadh; Brahmi, Noura; Saidi, Saber; Harrath, Abdel Halim; Alwasel, Saleh; Aldahmash, Waleed; El Feki, Abdelfatteh; Allagui, Mohamed Salah

2018-05-07

Cerium chloride (CeCl 3 ) is considered an environmental pollutant and a potent neurotoxic agent. Medicinal plants have many bioactive compounds that provide protection against damage caused by such pollutants. Curcuma longa is a bioactive compound-rich plant with very important antioxidant properties. To study the preventive and healing effects of Curcuma longa on cerium-damaged mouse brains, we intraperitoneally injected cerium chloride (CeCl 3 , 20 mg/kg BW) along with Curcuma longa extract, administrated by gavage (100 mg/kg BW), into mice for 60 days. We then examined mouse behavior, brain tissue damage, and brain oxidative stress parameters. Our results revealed a significant modification in the behavior of the CeCl 3 -treated mice. In addition, CeCl 3 induced a significant increment in lipid peroxidation, carbonyl protein (PCO), and advanced oxidation protein product levels, as well as a significant reduction in superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. Acetylcholinesterase (AChE) activity remarkably increased in the brain of CeCl 3 -treated mice. Histopathological observations confirmed these results. Curcuma longa attenuated CeCl 3 -induced oxidative stress and increased the activities of antioxidant enzymes. It also decreased AChE activity in the CeCl 3 -damaged mouse brain that was confirmed by histopathology. In conclusion, this study suggests that Curcuma longa has a neuroprotective effect against CeCl 3 -induced damage in the brain.

Direct stimulation of human fibroblasts by nCeO2 in vitro is attenuated with an amorphous silica coating.

PubMed

Davidson, Donna C; Derk, Raymond; He, Xiaoqing; Stueckle, Todd A; Cohen, Joel; Pirela, Sandra V; Demokritou, Philip; Rojanasakul, Yon; Wang, Liying

2016-05-04

Nano-scaled cerium oxide (nCeO2) is used in a variety of applications, including use as a fuel additive, catalyst, and polishing agent, yet potential adverse health effects associated with nCeO2 exposure remain incompletely understood. Given the increasing utility and demand for engineered nanomaterials (ENMs) such as nCeO2, "safety-by-design" approaches are currently being sought, meaning that the physicochemical properties (e.g., size and surface chemistry) of the ENMs are altered in an effort to maximize functionality while minimizing potential toxicity. In vivo studies have shown in a rat model that inhaled nCeO2 deposited deep in the lung and induced fibrosis. However, little is known about how the physicochemical properties of nCeO2, or the coating of the particles with a material such as amorphous silica (aSiO2), may affect the bio-activity of these particles. Thus, we hypothesized that the physicochemical properties of nCeO2 may explain its potential to induce fibrogenesis, and that a nano-thin aSiO2 coating on nCeO2 may counteract that effect. Primary normal human lung fibroblasts were treated at occupationally relevant doses with nCeO2 that was either left uncoated or was coated with aSiO2 (amsCeO2). Subsequently, fibroblasts were analyzed for known hallmarks of fibrogenesis, including cell proliferation and collagen production, as well as the formation of fibroblastic nodules. The results of this study are consistent with this hypothesis, as we found that nCeO2 directly induced significant production of collagen I and increased cell proliferation in vitro, while amsCeO2 did not. Furthermore, treatment of fibroblasts with nCeO2, but not amsCeO2, significantly induced the formation of fibroblastic nodules, a clear indicator of fibrogenicity. Such in vitro data is consistent with recent in vivo observations using the same nCeO2 nanoparticles and relevant doses. This effect appeared to be mediated through TGFβ signaling since chemical inhibition of the TGFβ receptor abolished these responses. These results indicate that differences in the physicochemical properties of nCeO2 may alter the fibrogenicity of this material, thus highlighting the potential benefits of "safety-by-design" strategies. In addition, this study provides an efficient in vitro method for testing the fibrogenicity of ENMs that strongly correlates with in vivo findings.

Synthesis, extraction and electronic structure of Ce@C2n

NASA Astrophysics Data System (ADS)

Liu, Bing-Bing; Zou, Guang-Tian; Yang, Hai-Bin; Yu, San; Lu, Jin-Shan; Liu, Zi-Yang; Liu, Shu-Ying; Xu, Wen-Guo

1997-11-01

In view of the growing interest in endohedral lanthanide fullerenes, Ce, as a typical+ 4 oxidation state lanthanide element, has been systematically studied. The synthesis, extraction and electronic structure of Ce @ C2n are investigated. Soot containing Ce@C2n was synthesized in high yield by carbonizing CeO2-containing graphite rods and are back-burning the CeC2-enriched cathode deposit in a DC arc plasma apparatus. Ce@C2n dominated by Ce@C82, can be efficiently extracted from the insoluble part of the soot after toluene Soxhlet extraction by pyridine at high temperature and high pressure in a closed vessel. About 60% Ce@C2n(2n = 82, 80, 78, 76) and 35% Ce@C82 can be enriched in the pyridine extract. This fact is identified by desorption electron impact mass spectrometry (DEI MS). The electronic structure of Ce@C2n is analyzed by using X-ray photoemission spectroscopy (XPS) of pyridine-free film. It is suggested that the encapsulated Ce atom is in a charge state close to+ 3 and was effectively protected from reaction with water and oxygen by the enclosing fullerene cage. Unlike theoretical expectation, the electronic state of Ce@C82 is formally described as Ce+3@C3-82.

High-resolution structural characterization and magnetic properties of epitaxial Ce-doped yttrium iron garnet thin films

NASA Astrophysics Data System (ADS)

Li, Zhong; Vikram Singh, Amit; Rastogi, Ankur; Gazquez, Jaume; Borisevich, Albina Y.; Mishra, Rohan; Gupta, Arunava

2017-07-01

Thin films of magnetic garnet materials, e.g. yttrium iron garnet (Y3Fe5O12, YIG), are useful for a variety of applications including microwave integrated circuits and spintronics. Substitution of rare earth ions, such as cerium, is known to enhance the magneto-optic Kerr effect (MOKE) as compared to pure YIG. Thin films of Ce0.75Y2.25Fe5O12 (Ce:YIG) have been grown using the pulsed laser deposition (PLD) technique and their crystal structure examined using high resolution scanning transmission electron microscopy. Homogeneous substitution of Ce in YIG, without oxidation to form a separate CeO2 phase, can be realized in a narrow process window with resulting enhancement of the MOKE signal. The thermally generated signal due to spin Seebeck effect for the optimally doped Ce:YIG films has also been investigated.

Reactor physics phenomena in additively manufactured control elements for the High Flux Isotope Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burns, Joseph R.; Petrovic, Bojan; Chandler, David

Additive manufacturing is under investigation as a novel method of fabricating the control elements (CEs) of the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory with greater simplicity, eliminating numerous highly complex fabrication steps and thereby offering potential for significant savings in cost, time, and effort. This process yields a unique CE design with lumped absorbers, a departure from traditionally manufactured CEs with uniformly distributed absorbing material. Here, this study undertakes a neutronics analysis of the impact of additively manufactured CEs on the HFIR core physics, seeking preliminary assessment of the feasibility of their practical use. The resultsmore » of the MCNP transport simulations reveal changes in the HFIR reactor physics arising from geometric and nuclear effects. Absorber lumping in the discrete CEs yields a large volume of unpoisoned material that is not present in the homogeneous design, in turn yielding increases in free thermal flux in the CE absorbing regions and their immediate vicinity. The availability of additional free thermal neutrons in the core yields an increase in fission rate density in the fuel closest to the CEs and a corresponding increase in neutron multiplication on the order of 100 pcm. The absorption behavior exhibited by the discrete CEs is markedly different from the homogeneous CEs due to several competing effects. Self-shielding arising from absorber lumping acts to reduce the effective absorption cross section of the discrete CEs, but this effect is offset by geometric and spectral effects. The operational performance of the discrete CEs is found to be comparable to the homogeneous CEs, with only limited deficiencies in reactivity worth that are expected to be operationally recoverable via limited adjustment of the CE positions and withdrawal rate. On the whole, these results indicate that the discrete CEs perform reasonably similarly to the homogeneous CEs and appear feasible for application in HFIR. In conclusion, the physical phenomena identified in this study provide valuable background for follow-up design studies.« less

Reactor physics phenomena in additively manufactured control elements for the High Flux Isotope Reactor

DOE PAGES

Burns, Joseph R.; Petrovic, Bojan; Chandler, David; ...

2018-02-22

Additive manufacturing is under investigation as a novel method of fabricating the control elements (CEs) of the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory with greater simplicity, eliminating numerous highly complex fabrication steps and thereby offering potential for significant savings in cost, time, and effort. This process yields a unique CE design with lumped absorbers, a departure from traditionally manufactured CEs with uniformly distributed absorbing material. Here, this study undertakes a neutronics analysis of the impact of additively manufactured CEs on the HFIR core physics, seeking preliminary assessment of the feasibility of their practical use. The resultsmore » of the MCNP transport simulations reveal changes in the HFIR reactor physics arising from geometric and nuclear effects. Absorber lumping in the discrete CEs yields a large volume of unpoisoned material that is not present in the homogeneous design, in turn yielding increases in free thermal flux in the CE absorbing regions and their immediate vicinity. The availability of additional free thermal neutrons in the core yields an increase in fission rate density in the fuel closest to the CEs and a corresponding increase in neutron multiplication on the order of 100 pcm. The absorption behavior exhibited by the discrete CEs is markedly different from the homogeneous CEs due to several competing effects. Self-shielding arising from absorber lumping acts to reduce the effective absorption cross section of the discrete CEs, but this effect is offset by geometric and spectral effects. The operational performance of the discrete CEs is found to be comparable to the homogeneous CEs, with only limited deficiencies in reactivity worth that are expected to be operationally recoverable via limited adjustment of the CE positions and withdrawal rate. On the whole, these results indicate that the discrete CEs perform reasonably similarly to the homogeneous CEs and appear feasible for application in HFIR. In conclusion, the physical phenomena identified in this study provide valuable background for follow-up design studies.« less

Differential effects of NAA and 2,4-D in reducing floret abscission in cestrum (Cestrum elegans) cut flowers are associated with their differential activation of Aux/IAA homologous genes.

PubMed

Abebie, Bekele; Lers, Amnon; Philosoph-Hadas, Sonia; Goren, Raphael; Riov, Joseph; Meir, Shimon

2008-01-01

A previous study showed that the relative effectiveness of 2,4-dichlorophenoxyacetic acid (2,4-D) compared with that of 1-naphthaleneacetic acid (NAA) in reducing floret bud abscission in cestrum (Cestrum elegans) cut flowers was due to its acropetal transport. The aim of the present study was to examine if the differential effect of these auxins on floret abscission is reflected in the expression of Aux/IAA genes in the floret abscission zone (AZ). cDNAs were isolated by PCR-based cloning from the floret AZ of auxin-treated cut flowers. The expression patterns of the cDNAs in various tissues and the effect of indole-3-acetic acid (IAA), applied with or without cycloheximide, on their expression in the floret AZ were examined by northern blot analysis. The regulation of transcript accumulation in the floret AZ in response to NAA or 2,4-D was measured by real-time PCR during auxin pulsing of cut flowers and vase life, concomitantly with floret abscission. Six isolated cDNAs were identified to represent Aux/IAA homologous genes, designated as Cestrum elegans (Ce)-IAA1 to Ce-IAA6. Four Ce-IAA genes were characterized as early auxin-responsive genes (ARGs), and two (Ce-IAA1 and Ce-IAA5) as late ARGs. Only Ce-IAA5 was AZ-specific in floret buds. A temporal regulation of Ce-IAA transcript levels in the floret AZ was found, with 2,4-D inducing higher expression levels than NAA in floret buds. These Ce-IAA expression levels were negatively correlated with floret abscission. The differential transport characteristics of NAA and 2,4-D in cestrum cut flowers were reflected in differential activation of the Ce-IAA genes identified in the floret AZ. Therefore, Aux/IAA genes can be used as molecular markers to measure auxin activity, which reflects free auxin level in the AZ. Two of the identified genes, Ce-IAA1 and Ce-IAA5, may also have a regulatory role in abscission.

Effect of CeO2 on Microstructure and Wear Resistance of TiC Bioinert Coatings on Ti6Al4V Alloy by Laser Cladding

PubMed Central

Wang, Haojun

2017-01-01

To solve the lack of wear resistance of titanium alloys for use in biological applications, various prepared coatings on titanium alloys are often used as wear-resistant materials. In this paper, TiC bioinert coatings were fabricated on Ti6Al4V by laser cladding using mixed TiC and ZrO2 powders as the basic pre-placed materials. A certain amount of CeO2 powder was also added to the pre-placed powders to further improve the properties of the TiC coatings. The effects of CeO2 additive on the phase constituents, microstructures and wear resistance of the TiC coatings were researched in detail. Although the effect of CeO2 on the phase constituents of the coatings was slight, it had a significant effect on the microstructure and wear resistance of the coatings. The crystalline grains in the TiC coatings, observed by a scanning electron microscope (SEM), were refined due to the effect of the CeO2. With the increase of CeO2 additive content in the pre-placed powders, finer and more compact dendrites led to improvement of the micro-hardness and wear resistance of the TiC coatings. Also, 5 wt % content of CeO2 additive in the pre-placed powders was the best choice for improving the wear properties of the TiC coatings. PMID:29301218

Cerium oxide nanoparticles, combining antioxidant and UV shielding properties, prevent UV-induced cell damage and mutagenesis

NASA Astrophysics Data System (ADS)

Caputo, Fanny; de Nicola, Milena; Sienkiewicz, Andrzej; Giovanetti, Anna; Bejarano, Ignacio; Licoccia, Silvia; Traversa, Enrico; Ghibelli, Lina

2015-09-01

Efficient inorganic UV shields, mostly based on refracting TiO2 particles, have dramatically changed the sun exposure habits. Unfortunately, health concerns have emerged from the pro-oxidant photocatalytic effect of UV-irradiated TiO2, which mediates toxic effects on cells. Therefore, improvements in cosmetic solar shield technology are a strong priority. CeO2 nanoparticles are not only UV refractors but also potent biological antioxidants due to the surface 3+/4+ valency switch, which confers anti-inflammatory, anti-ageing and therapeutic properties. Herein, UV irradiation protocols were set up, allowing selective study of the extra-shielding effects of CeO2vs. TiO2 nanoparticles on reporter cells. TiO2 irradiated with UV (especially UVA) exerted strong photocatalytic effects, superimposing their pro-oxidant, cell-damaging and mutagenic action when induced by UV, thereby worsening the UV toxicity. On the contrary, irradiated CeO2 nanoparticles, via their Ce3+/Ce4+ redox couple, exerted impressive protection on UV-treated cells, by buffering oxidation, preserving viability and proliferation, reducing DNA damage and accelerating repair; strikingly, they almost eliminated mutagenesis, thus acting as an important tool to prevent skin cancer. Interestingly, CeO2 nanoparticles also protect cells from the damage induced by irradiated TiO2, suggesting that these two particles may also complement their effects in solar lotions. CeO2 nanoparticles, which intrinsically couple UV shielding with biological and genetic protection, appear to be ideal candidates for next-generation sun shields.

The Rationale for Consuming Cognitive Enhancement Drugs in University Students and Teachers

PubMed Central

Sattler, Sebastian; Sauer, Carsten; Mehlkop, Guido; Graeff, Peter

2013-01-01

Cognitive enhancement (CE) is the pharmaceutical augmentation of mental abilities (e.g., learning or memory) without medical necessity. This topic has recently attracted widespread attention in scientific and social circles. However, knowledge regarding the mechanisms that underlie the decision to use CE medication is limited. To analyze these decisions, we used data from two online surveys of randomly sampled university teachers (N = 1,406) and students (N = 3,486). Each respondent evaluated one randomly selected vignette with regard to a hypothetical CE drug. We experimentally varied the characteristics of the drugs among vignettes and distributed them among respondents. In addition, the respondent’s internalization of social norms with respect to CE drug use was measured. Our results revealed that students were more willing to enhance cognitive performance via drugs than university teachers, although the overall willingness was low. The probability of side effects and their strength reduced the willingness to use CE drugs among students and university teachers, whereas higher likelihoods and magnitudes of CE increased this propensity. In addition, the internalized norm against CE drug use influenced decision making: Higher internalization decreased the willingness to use such medications. Students’ internalized norms more strongly affected CE abstinence compared with those of university teachers. Furthermore, internalized norms negatively interacted with the instrumental incentives for taking CE medication. This internalization limited the influence of and deliberation on instrumental incentives. This study is the first to provide empirical evidence regarding the importance of social norms and their influence on rational decision making with regard to CE. We identified previously undiscovered decision-making patterns concerning CE. Thus, this study provides insight into the motivators and inhibitors of CE drug use. These findings have implications for contending with CE behavior by highlighting the magnitude of potential side effects and by informing the debate regarding the ethics of CE use. PMID:23874778

The rationale for consuming cognitive enhancement drugs in university students and teachers.

PubMed

Sattler, Sebastian; Sauer, Carsten; Mehlkop, Guido; Graeff, Peter

2013-01-01

Cognitive enhancement (CE) is the pharmaceutical augmentation of mental abilities (e.g., learning or memory) without medical necessity. This topic has recently attracted widespread attention in scientific and social circles. However, knowledge regarding the mechanisms that underlie the decision to use CE medication is limited. To analyze these decisions, we used data from two online surveys of randomly sampled university teachers (N = 1,406) and students (N = 3,486). Each respondent evaluated one randomly selected vignette with regard to a hypothetical CE drug. We experimentally varied the characteristics of the drugs among vignettes and distributed them among respondents. In addition, the respondent's internalization of social norms with respect to CE drug use was measured. Our results revealed that students were more willing to enhance cognitive performance via drugs than university teachers, although the overall willingness was low. The probability of side effects and their strength reduced the willingness to use CE drugs among students and university teachers, whereas higher likelihoods and magnitudes of CE increased this propensity. In addition, the internalized norm against CE drug use influenced decision making: Higher internalization decreased the willingness to use such medications. Students' internalized norms more strongly affected CE abstinence compared with those of university teachers. Furthermore, internalized norms negatively interacted with the instrumental incentives for taking CE medication. This internalization limited the influence of and deliberation on instrumental incentives. This study is the first to provide empirical evidence regarding the importance of social norms and their influence on rational decision making with regard to CE. We identified previously undiscovered decision-making patterns concerning CE. Thus, this study provides insight into the motivators and inhibitors of CE drug use. These findings have implications for contending with CE behavior by highlighting the magnitude of potential side effects and by informing the debate regarding the ethics of CE use.

Effects of young barley leaf extract and antioxidative vitamins on LDL oxidation and free radical scavenging activities in type 2 diabetes.

PubMed

Yu, Y-M; Chang, W-C; Chang, C-T; Hsieh, C-L; Tsai, C E

2002-04-01

The effects of supplementation of young barley leaf extract (BL) and/or antioxidative vitamins C and E on different low-density lipoprotein (LDL) subfractions susceptibility to oxidation and free radical scavenging activities in patients with type 2 diabetes were evaluated. Thirty-six type 2 diabetic patients were enrolled in this study. The subjects received one of the following supplements daily for 4 weeks: 15 g BL, 200 mg vitamin C and 200 mg vitamin E (CE), or BL plus CE (BL + CE). The lucigenin-chemiluminescence (CL) and luminol-CL levels in blood were significantly reduced in all groups. Vitamin E content of LDL subfractions increased significantly following supplements, especially for BL + CE group. The percent increase of lag times in the BL + CE was significantly higher than those in the BL or CE group. The antioxidative effect of BL + CE was the greatest for small, dense LDL (Sd-LDL) with further increases in percentage of lag times 4 folds compared to BL alone. Our results indicate that supplementation with BL may help to scavenge oxygen free radicals, save the LDL-vitamin E content, and inhibit LDL oxidation. Furthermore, the addition of vitamins C and E to BL can inhibit the Sd-LDL oxidation more effectively, which may protect against vascular diseases in type 2 diabetic patients.

Differential genomic effects on signaling pathways by two different CeO2 nanoparticles in HepG2 cells

EPA Science Inventory

To investigate genomic effects, human liver hepatocellular carcinoma (HepG2) cells were exposed for three days to two different forms of nanoparticles both composed of Ce02 (0.3, 3 and 30 µg/mL). The two Ce02 nanopartices had dry primary particle sizes of 8 nanometers {(M) made b...

Biochemical effects of six TiO2 and four CeO2 nanomaterials in HepG2 cells

EPA Science Inventory

Biochemical effects of six TiO2 and four CeO2 nanomaterials in HepG2 cellsBecause of their growing number of uses, nanoparticles composed of CeO2 (cosmetics, polishing materials and automotive fuel additives) and TiO2 (pigments, sunscreens and photocatalysts) are of particular to...

Photoeffect cross sections of several rare-earth elements for 323-keV photons

NASA Astrophysics Data System (ADS)

Umesh, T. K.; Anasuya, S. J.; Shylaja Kumari, J.; Gowda, Channe; Gopinathan Nair, K. P.; Gowda, Ramakrishna

1992-02-01

Total-attenuation cross sections of the oxides of rare-earth elements such as La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, and Er, and also NaNO3 and NaNO2 have been measured in a narrow-beam geometry setup at 323 keV. The total-attenuation cross section for oxygen was obtained as the difference in NaNO3 and NaNO2 cross sections. Using this, the total-attenuation cross sections of the individual lanthanides have been obtained with the aid of the mixture rule. From these, the photoeffect cross sections were derived by subtracting the scattering contribution. These values are found to agree well with Scofield's theoretical data [University of California Report No. UCRL 51326, 1973 (unpublished)].

Enhancement of photocatalytic activity of combustion-synthesized CeO2/C3N4 nanoparticles

NASA Astrophysics Data System (ADS)

Li, Dong-Feng; Yang, Ke; Wang, Xiao-qin; Ma, Ya-Li; Huang, Gui-Fang; Huang, Wei-Qing

2015-09-01

Nanocrystalline CeO2/C3N4 was synthesized via a one-step solution combustion method using urea as fuel for the first time. The effects of the molar ratio of urea to cerium chloride on the photocatalytic activity of the synthesized samples were investigated. The synthesized nanocrystalline CeO2/C3N4 shows small size and large surface exposure area. Photocatalytic degradation of methylene blue demonstrates that the synthesized nanocrystalline CeO2/C3N4 possesses enhanced photocatalytic activity. It is proposed that the enhanced photocatalytic activity might be related to the favorable morphology and structure, and the effective charge separation between C3N4 and CeO2 in the photocatalytic process.

Cinnamon extract regulates plasma levels of adipose-derived factors and expression of multiple genes related to carbohydrate metabolism and lipogenesis in adipose tissue of fructose-fed rats.

PubMed

Qin, B; Polansky, M M; Anderson, R A

2010-03-01

We reported earlier that dietary cinnamon extract (CE) improves systemic insulin sensitivity and dyslipidemia by enhancing insulin signaling. In the present study, we have examined the effects of CE on several biomarkers including plasma levels of adipose-derived adipokines, and the potential molecular mechanisms of CE in epididymal adipose tissue (EAT). In Wistar rats fed a high-fructose diet (HFD) to induce insulin resistance, supplementation with a CE (Cinnulin PF, 50 mg/kg daily) for 8 weeks reduced blood glucose, plasma insulin, triglycerides, total cholesterol, chylomicron-apoB48, VLDL-apoB100, and soluble CD36. CE also inhibited plasma retinol binding protein 4 (RBP4) and fatty acid binding protein 4 (FABP4) levels. CE-induced increases in plasma adiponectin were not significant. CE did not affect food intake, bodyweight, and EAT weight. In EAT, there were increases in the insulin receptor ( IR) and IR substrate 2 ( IRS2) mRNA, but CE-induced increases in mRNA expression of IRS1, phosphoinositide-3-kinase, AKT1, glucose transporters 1 and 4 , and glycogen synthase 1 expression and decreased trends in mRNA expression of glycogen synthase kinase 3beta were not statistically significant. CE also enhanced the mRNA levels of ADIPOQ, and inhibited sterol regulatory element binding protein-1c mRNA levels. mRNA and protein levels of fatty acid synthase and FABP4 were inhibited by CE and RBP4, and CD36 protein levels were also decreased by CE. These results suggest that CE effectively ameliorates circulating levels of adipokines partially mediated via regulation of the expression of multiple genes involved in insulin sensitivity and lipogenesis in the EAT.

Magnesium deficiency results in damage of nitrogen and carbon cross-talk of maize and improvement by cerium addition.

PubMed

Zhao, Haiquan; Zhou, Qiuping; Zhou, Min; Li, Chunxiao; Gong, Xiaolan; Liu, Chao; Qu, Chunxiang; Si, Wenhui; Hong, Fashui

2012-07-01

Magnesium (Mg) deficiency has been reported to affect plant photosynthesis and growth, and cerium (Ce) was considered to be able to improve plant growth. However, the mechanisms of Mg deficiency and Ce on plant growth remain poorly understood. The main aim of this work is to identify whether or not Mg deprivation affects the interdependent nitrogen and carbon assimilations in the maize leaves and whether or not Ce modulates the assimilations in the maize leaves under Mg deficiency. Maize plants were cultivated in Hoagland’s solution. They were subjected to Mg deficiency and to cerium chloride administration in the Mg-present Hoagland’s media and Mg-deficient Hoagland’s media.After 2 weeks,we measured chlorophyll (Chl) a fluorescence and the activities of nitrate reductase (NR), sucrose-phosphate synthase(SPS), and phosphoenolpyruvate carboxylase (PEPCase)in metabolic checkpoints coordinating primary nitrogen and carbon assimilations in the maize leaves. The results showed that Mg deficiency significantly inhibited plant growth and decreased the activities of NR, SPS, and PEPCase and the synthesis of Chl and protein. Mg deprivation in maize also significantly decreased the oxygen evolution, electron transport,and efficiency of photochemical energy conversion by photosystem II (PSII). However, Ce addition may promote nitrogen and carbon assimilations, increase PSII activities,and improve maize growth under Mg deficiency. Moreover,our findings would help promote usage of Mg or Ce fertilizers in maize production.

Adult acetabulo - pelvic parameters in Turkish society: A descriptive radiological study.

PubMed

Aydin, Murat; Kircil, Cihan; Polat, Onur; Arikan, Murat; Erdemli, Bülent

2016-12-01

The aim of this study was to measure the prevalences of the acetabular index, collodiaphyseal angle, CE angle, articulo-trochanteric distance, cross-over sign and posterior wall sign in healthy Turkish people, in order to shed light on the production of orthopedic medical products. In this study, both hips (a total of 3960 hips) of 1980 individuals (1178 males, 802 females) from nine different cities between the ages of 18 and 65 years were measured and statistically analyzed. The right articulo-trochanteric distance of all participants was 19.67 ± 4.52 mm and the left articulo-trochanteric distance was 19.10 ± 4.58 mm. The CE angle was 35.11°±7.41° in the right hip and 35.37°±6.76° in the left hip. The acetabular index was 37.58°±5.30° in the right hip and 37.80°±4.82° in the left hip. The collodiaphyseal angle was 138.60°±8.27° in the right and 137.84°±8.01° in the left hip. The prevalence of cross-over sign in the right hip was 6.46% and 6.66% for the left hip. The prevalence of posterior wall sign was 4.24% for the right hip and 4.19% for the left hip. This study has provided prevalence values of cross-over sign, posterior wall sign, acetabular index, collodiaphyseal angle, CE angle and articulo-trochanteric distances of a healthy Turkish population between the ages of 18 and 65 years. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

Restoration of quinine-stimulated Fos-immunoreactive neurons in the central nucleus of the amygdala and gustatory cortex following reinnervation or cross-reinnervation of the lingual taste nerves in rats.

PubMed

King, Camille Tessitore; Garcea, Mircea; Spector, Alan C

2014-08-01

Remarkably, when lingual gustatory nerves are surgically rerouted to inappropriate taste fields in the tongue, some taste functions recover. We previously demonstrated that quinine-stimulated oromotor rejection reflexes and neural activity (assessed by Fos immunoreactivity) in subregions of hindbrain gustatory nuclei were restored if the posterior tongue, which contains receptor cells that respond strongly to bitter compounds, was cross-reinnervated by the chorda tympani nerve. Such functional recovery was not seen if instead, the anterior tongue, where receptor cells are less responsive to bitter compounds, was cross-reinnervated by the glossopharyngeal nerve, even though this nerve typically responds robustly to bitter substances. Thus, recovery depended more on the taste field being reinnervated than on the nerve itself. Here, the distribution of quinine-stimulated Fos-immunoreactive neurons in two taste-associated forebrain areas was examined in these same rats. In the central nucleus of the amygdala (CeA), a rostrocaudal gradient characterized the normal quinine-stimulated Fos response, with the greatest number of labeled cells situated rostrally. Quinine-stimulated neurons were found throughout the gustatory cortex, but a "hot spot" was observed in its anterior-posterior center in subregions approximating the dysgranular/agranular layers. Fos neurons here and in the rostral CeA were highly correlated with quinine-elicited gapes. Denervation of the posterior tongue eliminated, and its reinnervation by either nerve restored, numbers of quinine-stimulated labeled cells in the rostralmost CeA and in the subregion approximating the dysgranular gustatory cortex. These results underscore the remarkable plasticity of the gustatory system and also help clarify the functional anatomy of neural circuits activated by bitter taste stimulation. © 2014 Wiley Periodicals, Inc.

Artificial neural networks for the diagnosis of aggressive periodontitis trained by immunologic parameters.

PubMed

Papantonopoulos, Georgios; Takahashi, Keiso; Bountis, Tasos; Loos, Bruno G

2014-01-01

There is neither a single clinical, microbiological, histopathological or genetic test, nor combinations of them, to discriminate aggressive periodontitis (AgP) from chronic periodontitis (CP) patients. We aimed to estimate probability density functions of clinical and immunologic datasets derived from periodontitis patients and construct artificial neural networks (ANNs) to correctly classify patients into AgP or CP class. The fit of probability distributions on the datasets was tested by the Akaike information criterion (AIC). ANNs were trained by cross entropy (CE) values estimated between probabilities of showing certain levels of immunologic parameters and a reference mode probability proposed by kernel density estimation (KDE). The weight decay regularization parameter of the ANNs was determined by 10-fold cross-validation. Possible evidence for 2 clusters of patients on cross-sectional and longitudinal bone loss measurements were revealed by KDE. Two to 7 clusters were shown on datasets of CD4/CD8 ratio, CD3, monocyte, eosinophil, neutrophil and lymphocyte counts, IL-1, IL-2, IL-4, INF-γ and TNF-α level from monocytes, antibody levels against A. actinomycetemcomitans (A.a.) and P.gingivalis (P.g.). ANNs gave 90%-98% accuracy in classifying patients into either AgP or CP. The best overall prediction was given by an ANN with CE of monocyte, eosinophil, neutrophil counts and CD4/CD8 ratio as inputs. ANNs can be powerful in classifying periodontitis patients into AgP or CP, when fed by CE values based on KDE. Therefore ANNs can be employed for accurate diagnosis of AgP or CP by using relatively simple and conveniently obtained parameters, like leukocyte counts in peripheral blood. This will allow clinicians to better adapt specific treatment protocols for their AgP and CP patients.

Are the oxygen uptake and heart rate off-kinetics influenced by the intensity of prior exercise?

PubMed

do Nascimento Salvador, Paulo Cesar; de Aguiar, Rafael Alves; Teixeira, Anderson Santiago; Souza, Kristopher Mendes de; de Lucas, Ricardo Dantas; Denadai, Benedito Sérgio; Guglielmo, Luiz Guilherme Antonacci

2016-08-01

The aim of this study was to investigate the effect of prior exercise on the heart rate (HR) and oxygen uptake (VO2) off-kinetics after a subsequent high-intensity running exercise. Thirteen male futsal players (age 22.8±6.1years) performed a series of high-intensity bouts without prior exercise (control), preceded by a prior same intensity continuous exercise (CE+CE) and a prior sprint exercise (SE+CE). The magnitude of excess post-exercise oxygen consumption (EPOCm-4.25±0.19 vs. 3.69±0.20Lmin(-1) in CE+CE and 3.62±0.18Lmin(-1) in control; p<0.05) and the parasympathetic reactivation (HRR60s-33±3 vs. 37±3bpm in CE+CE and 42±3 bpm in control; p<0.05) in the SE+CE were higher and slower, compared with another two conditions. The EPOCτ (time to attain 63% of total response; 53±2s) and the heart rate time-course (HRτ-86±5s) were significantly longer after the SE+CE condition than control transition (48±2s and 69±5s, respectively; p<0.05). The SE+CE induce greater stress on the metabolic function, respiratory system and autonomic nervous system regulation during post-exercise recovery than CE, highlighting that the inclusion of sprint-based exercises can be an effective strategy to increase the total energy expenditure following an exercise session. Copyright © 2016 Elsevier B.V. All rights reserved.

Adsorption of Cr(VI) on cerium immobilized cross-linked chitosan composite in single system and coexisted with Orange II in binary system.

PubMed

Zhu, Tianyi; Huang, Wei; Zhang, Lingfan; Gao, Jie; Zhang, Wenqing

2017-10-01

In this work, cerium immobilized cross-linked chitosan (CTS-Ce) composite, employed as an efficient adsorbent for Cr(VI) in single system and coexisted with Orange II (OII) in binary system, was prepared by co-precipitation method. The as-obtained adsorbent was characterized by FTIR, SEM, EDS and XPS before and after adsorption. The adsorption behaviors of Cr(VI) in single and binary system were systematically studied. The maximum adsorption capacity of Cr(VI) on CTS-Ce (202.8mg/g) was calculated by Langmuir equation in single metal system, but it decreased to 112.9mg/g with initial concentration of 100mg/L OII in binary system at pH 2 and 293K. The adsorption data for Cr(VI) followed the Langmuir model in single system, while fitted Temkin model well in binary system. In both single and binary system, the kinetics of adsorption exhibited pseudo-second order behavior and adsorption capacity increased with increasing temperature. Moreover, the data of thermodynamic parameters (ΔG°<0, ΔH°>0) indicated that the adsorption was a spontaneous and endothermic process. Besides, |ΔG Cr |>|ΔG Cr-OII | at the same temperature further suggested that Cr(VI) was adsorbed on the CTS-Ce composite faster in binary system than in single system. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparative analysis of the diagnostic performance of crude sheep hydatid cyst fluid, purified antigen B and its subunit (12 Kda), assessed by ELISA, in the diagnosis of human cystic echinococcosis.

PubMed

Tawfeek, Gihan M; Elwakil, Hala S; El-Hoseiny, Laila; Thabet, Hala S; Sarhan, Rania M; Awad, Nabil S; Anwar, Wagida A

2011-02-01

The diagnosis of patients with cystic echinococcosis (CE) by means of serology has a limited support in clinical practice due to cross-reactivity with other helminthes leading to overestimation of the parasite's true prevalence. A wealth of reports on the diagnostic performance of antigen B (AgB) has been produced. This study was designed to comparatively assess the diagnostic efficacy of crude sheep hydatid cyst fluid (HCF), AgB and its subunit (12 KDa) to detect IgG or IgG4 antibodies in CE patients' sera using enzyme-linked immunosorbent assay (ELISA).The best diagnostic performance was obtained with anti-HCF IgG ELISA which gave 92.4% sensitivity and 92.6% specificity. Despite the low sensitivity of anti AgB IgG ELISA (84%), it gave the best specificity (94.4%) with less cross-reaction with sera of subjects infected with other parasites. In conclusion, it is recommended to use anti-HCF IgG ELISA for initial screening in large seroprevalence studies. Further analysis of positive serum samples with anti AgB IgG ELISA would allow the confirmation of true positives. Specific IgG4 ELISA may represent a complementary assay, useful as secondary confirmatory tests for patients with suspected CE and negative for total IgG ELISA.

Unusual Kondo-hole effect and crystal-field frustration in Nd-doped CeRhIn 5

DOE PAGES

Rosa, Priscila Ferrari Silveira; Oostra, Aaron; Thompson, Joe David; ...

2016-07-05

In this research, we investigate single crystals of Ce 1₋xNd xRhIn 5 by means of x-ray-diffraction, microprobe, magnetic susceptibility, heat capacity, and electrical resistivity measurements. Our data reveal that the antiferromagnetic transition of CeRhIn 5, at Tmore » $$Ce\\atop{N}$$=3.8 K, is linearly suppressed with x Nd. We associate this effect with the presence of a “Kondo hole” created by Nd substitution. The extrapolation of T$$Ce\\atop{N}$$ to zero temperature, however, occurs at x c~0.3, which is below the two-dimensional percolation limit found in Ce 1₋xLa xRhIn 5. This result strongly suggests the presence of a crystal-field induced magnetic frustration. Near x Nd~0.2, the Ising antiferromagnetic order from Nd 3+ ions is stabilized and T$$Nd\\atop{N}$$ increases up to 11 K in NdRhIn 5. Finally, our results shed light on the effects of magnetic doping in heavy-fermion antiferromagnets and stimulate the study of such systems under applied pressure.« less

In vivo and in vitro antidiabetic effects of aqueous cinnamon extract and cinnamon polyphenol-enhanced food matrix

PubMed Central

Cheng, Diana M.; Kuhn, Peter; Poulev, Alexander; Rojo, Leonel E.; Lila, Mary Ann; Raskin, Ilya

2012-01-01

Cinnamon has a long history of medicinal use and continues to be valued for its therapeutic potential for improving metabolic disorders such as type 2 diabetes. In this study, a phytochemically-enhanced functional food ingredient that captures water soluble polyphenols from aqueous cinnamon extract (CE) onto a protein rich matrix was developed. CE and cinnamon polyphenol-enriched defatted soy flour (CDSF) were effective in acutely lowering fasting blood glucose levels in diet-induced obese hyperglycemic mice at 300 and 600 mg/kg, respectively. To determine mechanisms of action, rat hepatoma cells were treated with CE and eluates of CDSF at a range of 1–25 µg/ml. CE and eluates of CDSF demonstrated dose-dependent inhibition of hepatic glucose production with significant levels of inhibition at 25 µg/ml. Furthermore, CE decreased the gene expression of two major regulators of hepatic gluconeogenesis, phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. The hypoglycemic and insulin-like effects of CE and CDSF may help to ameliorate type 2 diabetes conditions. PMID:22980902

[Effects of colorants on yttria stabilized tetragonal zirconia polycrystals powder].

PubMed

Wang, Bo; Chen, Jianfeng; Zhang, Yanchun; Wang, Ru

2015-10-01

To evaluate the effect of Fe2O3 and CeO2 as colorants on yttria stabilized tetragonal zirconia poly-crystals (Y-TZP) powder. The spray granulation slurry of colored zirconia was prepared with different concentrations of Fe2O3 (0.15%) and CeO2 (4%), which were added in Y-TZP. Zirconia powder was made by spray granulation. The powder specimens were divided into three groups: uncolored zirconia, Fe2O3 (0.15%) zirconia, and CeO2 (4%) zirconia. The particle morphologies of the powder specimens were measured with a laser particle size analyzer and an optical microscope. The differences in D50 among the three groups were statistically significant (P<0.05). Group Fe2O3 showed a significant difference from groups CeO2 and uncolored zirconia (P<0.05). Group uncolored zirconia showed no significant difference from group CeO2 (P>0.05). Mostly spherical powder was observed in the three groups. Fe2O3 as a colorant can affect particles, whereas CeO2 has no effect.

The effect of fission-energy Xe ion irradiation on the structural integrity and dissolution of the CeO2 matrix

NASA Astrophysics Data System (ADS)

Popel, A. J.; Le Solliec, S.; Lampronti, G. I.; Day, J.; Petrov, P. K.; Farnan, I.

2017-02-01

This work considers the effect of fission fragment damage on the structural integrity and dissolution of the CeO2 matrix in water, as a simulant for the UO2 matrix of spent nuclear fuel. For this purpose, thin films of CeO2 on Si substrates were produced and irradiated by 92 MeV 129Xe23+ ions to a fluence of 4.8 × 1015 ions/cm2 to simulate fission damage that occurs within nuclear fuels along with bulk CeO2 samples. The irradiated and unirradiated samples were characterised and a static batch dissolution experiment was conducted to study the effect of the induced irradiation damage on dissolution of the CeO2 matrix. Complex restructuring took place in the irradiated films and the irradiated samples showed an increase in the amount of dissolved cerium, as compared to the corresponding unirradiated samples. Secondary phases were also observed on the surface of the irradiated CeO2 films after the dissolution experiment.

In vivo and in vitro antidiabetic effects of aqueous cinnamon extract and cinnamon polyphenol-enhanced food matrix.

PubMed

Cheng, Diana M; Kuhn, Peter; Poulev, Alexander; Rojo, Leonel E; Lila, Mary Ann; Raskin, Ilya

2012-12-15

Cinnamon has a long history of medicinal use and continues to be valued for its therapeutic potential for improving metabolic disorders such as type 2 diabetes. In this study, a phytochemically-enhanced functional food ingredient that captures water soluble polyphenols from aqueous cinnamon extract (CE) onto a protein rich matrix was developed. CE and cinnamon polyphenol-enriched defatted soy flour (CDSF) were effective in acutely lowering fasting blood glucose levels in diet induced obese hyperglycemic mice at 300 and 600 mg/kg, respectively. To determine mechanisms of action, rat hepatoma cells were treated with CE and eluates of CDSF at a range of 1-25 μg/ml. CE and eluates of CDSF demonstrated dose-dependent inhibition of hepatic glucose production with significant levels of inhibition at 25 μg/ml. Furthermore, CE decreased the gene expression of two major regulators of hepatic gluconeogenesis, phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. The hypoglycemic and insulin-like effects of CE and CDSF may help to ameliorate type 2 diabetes conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Ce-Sn binary oxide catalyst for the selective catalytic reduction of NOx by NH3

NASA Astrophysics Data System (ADS)

Liu, Zhiming; Feng, Xu; Zhou, Zizheng; Feng, Yongjun; Li, Junhua

2018-01-01

Ce-Sn binary oxide catalysts prepared by the hydrothermal method have been investigated for the selective catalytic reduction (SCR) of NOx with NH3. Compared with pure CeO2 and SnO2, Ce-Sn binary oxide catalyst showed significantly higher NH3-SCR activity. Moreover, Ce-Sn catalyst showed high resistance against H2O and SO2. The high catalytic performance of Ce-Sn binary oxide is attributed to the synergetic effect between Ce and Sn species, which not only enhances the redox property of the catalyst but also increases the Lewis acidity, thus promoting the adsorption and activation of NH3 species, which contributes to improving the NH3-SCR performance.

Environmentally friendly synthesis of CeO2 nanoparticles for the catalytic oxidation of benzyl alcohol to benzaldehyde and selective detection of nitrite

NASA Astrophysics Data System (ADS)

Tamizhdurai, P.; Sakthinathan, Subramanian; Chen, Shen-Ming; Shanthi, K.; Sivasanker, S.; Sangeetha, P.

2017-04-01

Cerium oxide nanoparticles (CeO2 NPs) are favorable in nanotechnology based on some remarkable properties. In this study, the crystalline CeO2 NPs are successfully prepared by an efficient microwave combustion (MCM) and conventional route sol-gel (CRSGM) methods. The structural morphology of the as-prepared CeO2 NPs was investigated by various spectroscopic and analytical techniques. Moreover, the XRD pattern confirmed the formation of CeO2 NPs as a face centered cubic structure. The magnetometer studies indicated the low saturation magnetization (23.96 emu/g) of CeO2 NPs for weak paramagnetic and high saturation magnetization (32.13 emu/g) of CeO2 NPs for super paramagnetic. After that, the oxidation effect of benzyl alcohol was investigated which reveals good conversion and selectivity. Besides, the CeO2 NPs modified glassy carbon electrode (GCE) used for the detection of nitrite with linear concentration range (0.02-1200 μM), low limit of detection (0.21 μM) and higher sensitivity (1.7238 μAμM-1 cm-2). However, the CeO2 NPs modified electrode has the fast response, high sensitivity and good selectivity. In addition, the fabricated electrode is applied for the determination of nitrite in various water samples. Eventually, the CeO2 NPs can be regarded as an effective way to enhance the catalytic activity towards the benzyl alcohol and nitrite.

Environmentally friendly synthesis of CeO2 nanoparticles for the catalytic oxidation of benzyl alcohol to benzaldehyde and selective detection of nitrite

PubMed Central

Tamizhdurai, P.; Sakthinathan, Subramanian; Chen, Shen-Ming; Shanthi, K.; Sivasanker, S.; Sangeetha, P.

2017-01-01

Cerium oxide nanoparticles (CeO2 NPs) are favorable in nanotechnology based on some remarkable properties. In this study, the crystalline CeO2 NPs are successfully prepared by an efficient microwave combustion (MCM) and conventional route sol-gel (CRSGM) methods. The structural morphology of the as-prepared CeO2 NPs was investigated by various spectroscopic and analytical techniques. Moreover, the XRD pattern confirmed the formation of CeO2 NPs as a face centered cubic structure. The magnetometer studies indicated the low saturation magnetization (23.96 emu/g) of CeO2 NPs for weak paramagnetic and high saturation magnetization (32.13 emu/g) of CeO2 NPs for super paramagnetic. After that, the oxidation effect of benzyl alcohol was investigated which reveals good conversion and selectivity. Besides, the CeO2 NPs modified glassy carbon electrode (GCE) used for the detection of nitrite with linear concentration range (0.02–1200 μM), low limit of detection (0.21 μM) and higher sensitivity (1.7238 μAμM−1 cm−2). However, the CeO2 NPs modified electrode has the fast response, high sensitivity and good selectivity. In addition, the fabricated electrode is applied for the determination of nitrite in various water samples. Eventually, the CeO2 NPs can be regarded as an effective way to enhance the catalytic activity towards the benzyl alcohol and nitrite. PMID:28406231

Effects of NH₄⁺ on Ce(IV) electro-regeneration in simulated and real spent TFT-LCD Cr-etching solutions.

PubMed

Chen, Te-San; Huang, Kuo-Lin; Lai, Yu-Chan; Kuo, Yi-Ming

2012-08-15

This investigation studies the electro-regeneration of Ce(IV) from Ce(III) in 4 M HNO(3) in the presence/absence of NH(4)(+) and real spent thin-film transistor liquid-crystal display (TFT-LCD) Cr-etching solutions. On Pt, at 2 A and 70 °C for 100 min, the Ce(IV) yield and apparent rate constant of Ce(III) oxidation in 4 M HNO(3) without NH(4)(+) were 100% and 5.54 × 10(-4) s(-1), respectively (and the activation energy was 13.1 kJ mol(-1)). Cyclic voltammetric and electrolytic measurements consistently support the noticeable inhibition by NH(4)(+) of Ce(III) oxidation and lowering of the Ce(IV) yield, respectively. The apparent diffusion coefficients for 0.2 and 0.02 M Ce(III) oxidation in 4 M HNO(3) that contained 0-0.6 M NH(4)(+) were (0.38-0.25) × 10(-5) and (1.6-0.9) × 10(-5) cm(2) s(-1), respectively. Because of combined effects of NH(4)(+) and anion impurities, the 100 min Ce(IV) yield of a real spent TFT-LCD Cr-etching solution (with [NH(4)(+)]/[Ce(III)] = 0.74 M/0.39 M) was 82%, lower than that of 4 M HNO(3) without NH(4)(+), but higher than those of 4 M HNO(3) that contained anion impurities with/without 0.4 M NH(4)(+). Copyright © 2012 Elsevier Ltd. All rights reserved.

Toxicity of CeO2 nanoparticles - the effect of nanoparticle properties.

PubMed

Leung, Yu Hang; Yung, Mana M N; Ng, Alan M C; Ma, Angel P Y; Wong, Stella W Y; Chan, Charis M N; Ng, Yip Hang; Djurišić, Aleksandra B; Guo, Muyao; Wong, Mabel Ting; Leung, Frederick C C; Chan, Wai Kin; Leung, Kenneth M Y; Lee, Hung Kay

2015-04-01

Conflicting reports on the toxicity of CeO2 nanomaterials have been published in recent years, with some studies finding CeO2 nanoparticles to be toxic, while others found it to have protective effects against oxidative stress. To investigate the possible reasons for this, we have performed a comprehensive study on the physical and chemical properties of nanosized CeO2 from three different suppliers as well as CeO2 synthesized by us, and tested their toxicity. For toxicity tests, we have studied the effects of CeO2 nanoparticles on a Gram-negative bacterium Escherichia coli in the dark, under ambient and UV illuminations. We have also performed toxicity tests on the marine diatom Skeletonema costatum under ambient and UV illuminations. We found that the CeO2 nanoparticle samples exhibited significantly different toxicity, which could likely be attributed to the differences in interactions with cells, and possibly to differences in nanoparticle compositions. Our results also suggest that toxicity tests on bacteria may not be suitable for predicting the ecotoxicity of nanomaterials. The relationship between the toxicity and physicochemical properties of the nanoparticles is explicitly discussed in the light of the current results. Copyright © 2015 Elsevier B.V. All rights reserved.

Superior performance of Ni–W–Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

DOE PAGES

Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; ...

2014-11-26

In this study, the ethanol steam reforming (ESR) reaction was examined over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO₂ lattice, with the remaining Ni forming highly dispersed nano NiO (< 2 nm) outside the Ni-W-Ce oxide structure. The nano NiO was reduced to Nimore » under ESR conditions. The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.« less

Post-Treatment Follow-Up Study of Abdominal Cystic Echinococcosis in Tibetan Communities of Northwest Sichuan Province, China

PubMed Central

Li, Tiaoying; Ito, Akira; Pengcuo, Renqing; Sako, Yasuhito; Chen, Xingwang; Qiu, Dongchuan; Xiao, Ning; Craig, Philip S.

2011-01-01

Background Human cystic echinococcosis (CE), caused by the larval stage of Echinococcus granulosus, with the liver as the most frequently affected organ, is known to be highly endemic in Tibetan communities of northwest Sichuan Province. Antiparasitic treatment with albendazole remains the primary choice for the great majority of patients in this resource-poor remote area, though surgery is the most common approach for CE therapy that has the potential to remove cysts and lead to complete cure. The current prospective study aimed to assess the effectiveness of community based use of cyclic albendazole treatment in Tibetan CE cases, and concurrently monitor the changes of serum specific antibody levels during treatment. Methodology/Principal Findings Ultrasonography was applied for diagnosis and follow-up of CE cases after cyclic albendazole treatment in Tibetan communities of Sichuan Province during 2006 to 2008, and serum specific IgG antibody levels against Echinococcus granulosus recombinant antigen B in ELISA was concurrently monitored in these cases. A total of 196 CE cases were identified by ultrasound, of which 37 (18.9%) showed evidence of spontaneous healing/involution of hepatic cyst(s) with CE4 or CE5 presentations. Of 49 enrolled CE cases for treatment follow-up, 32.7% (16) were considered to be cured based on B-ultrasound after 6 months to 30 months regular albendazole treatment, 49.0% (24) were improved, 14.3% (7) remained unchanged, and 4.1% (2) became aggravated. In general, patients with CE2 type cysts (daughter cysts present) needed a longer treatment course for cure (26.4 months), compared to cases with CE1 (univesicular cysts) (20.4 months) or CE3 type (detached cyst membrane or partial degeneration of daughter cysts) (9 months). In addition, the curative duration was longer in patients with large (>10 cm) cysts (22.3 months), compared to cases with medium (5–10 cm) cysts (17.3 months) or patients with small (<5 cm) cysts (6 months). At diagnosis, seven (53.8%) of 13 cases with CE1 type cysts without any previous intervention showed negative specific IgG antibody response to E. granulosus recombinant antigen B (rAgB). However, following 3 months to 18 months albendazole therapy, six of these 7 initially seronegative CE1 cases sero-converted to be specific IgG antibody positive, and concurrently ultrasound scan showed that cysts changed to CE3a from CE1 type in all the six CE cases. Two major profiles of serum specific IgG antibody dynamics during albendazole treatment were apparent in CE cases: (i) presenting as initial elevation followed by subsequent decline, or (ii) a persistent decline. Despite a decline, however, specific antibody levels remained positive in most improved or cured CE cases. Conclusions This was the first attempt to follow up community-screened cystic echinococcosis patients after albendazole therapy using ultrasonography and serology in an endemic Tibetan region. Cyclic albendazole treatment proved to be effective in the great majority of CE cases in this resource-poor area, but periodic abdominal ultrasound examination was necessary to guide appropriate treatment. Oral albendazole for over 18 months was more likely to result in CE cure. Poor drug compliance resulted in less good outcomes. Serology with recombinant antigen B could provide additional limited information about the effectiveness of albendazole in CE cases. Post-treatment positive specific IgG antibody seroconversion, in initially seronegative, CE1 patients was considered a good indication for positive therapeutic efficacy of albendazole. PMID:22039558

Fast neutron measurements using Cs2LiYCl6:Ce (CLYC) scintillator

NASA Astrophysics Data System (ADS)

Smith, M. B.; Achtzehn, T.; Andrews, H. R.; Clifford, E. T. H.; Forget, P.; Glodo, J.; Hawrami, R.; Ing, H.; O'Dougherty, P.; Shah, K. S.; Shirwadkar, U.; Soundara-Pandian, L.; Tower, J.

2015-06-01

Samples of Cs2LiYCl6:Ce (CLYC) scintillator have been characterized using monoenergetic neutron beams in the energy range 4.1-5.5 MeV. Four crystals with dimensions (thickness×diameter) of 1″×1″, 1″×2″, and 2″×2″ were evaluated, including one crystal with natural concentrations of Li isotopes and three that were enriched in 6Li. The intrinsic efficiency of CLYC for fast-neutron detection has been determined for the natural-Li crystal. These measurements were translated into reaction cross-sections, and show good agreement with available cross-section data for neutron interactions with the 35Cl component of CLYC. Furthermore, it is shown that the charged-particle energy released in the fast-neutron reactions on 35Cl varies linearly with the energy of the incoming neutron. These results verify the efficacy of CLYC for fast-neutron spectroscopy in a range of applications.

Americium-241 integral radiative capture cross section in over-moderated neutron spectrum from pile oscillator measurements in the Minerve reactor

NASA Astrophysics Data System (ADS)

Geslot, Benoit; Gruel, Adrien; Ros, Paul; Blaise, Patrick; Leconte, Pierre; Noguere, Gilles; Mathieu, Ludovic; Villamarin, David; Becares, Vicente; Plompen, Arjan; Kopecky, Stefan; Schillebeeckx, Peter

2017-09-01

An experimental program, called AMSTRAMGRAM, was recently conducted in the Minerve low power reactor operated by CEA Cadarache within the frame of the CHANDA initiative (Solving CHAllenges in Nuclear Data). Its aim was to measure the integral capture cross section of 241Am in the thermal domain. Motivation of this work is driven by large differences in this actinide thermal point reported by major nuclear data libraries. The AMSTRAMGRAM experiment, that made use of well characterized EC-JRC americium samples, was based on the oscillation technique commonly implemented in the Minerve reactor. First results are presented and discussed in this article. A preliminary calculation scheme was used to compare measured and calculated results. It is shown that this work confirms a bias previously observed with JEFF-3.1.1 (C/E-1 = -10.5 ± 2%). On the opposite, the experiment is in close agreement with 241Am thermal point reported in JEFF-3.2 (C/E-1 = 0.5 ± 2%).

Innovating in the teaching of Chemical Equilibrium: Taking effective advantage of Information and Communication Technologies

NASA Astrophysics Data System (ADS)

Fonseca, Susana Cristina Morais da

Chemical Equilibrium (CE) is a good example of the specific nature of chemistry. The understanding of this theme requires the conceptualization of macroscopic events, as well as explanations of sub microscopic nature, application of symbolic language and mathematics. CE is commonly identified as a topic suitable for the pedagogical use of Information and Communication Technologies (ICT). However, the growth in the roll of digital resources for the teaching of CE, that took place in the last decades, was not accompanied by a decrease in the signalling of students' difficulties and misconceptions in the subject. This fact, points out the relevance of clarifying the circumstances under which digital resources turn out to be useful in the teaching of CE and develop educative modules that take into account the findings and recommendations from the literature. This project aims to bring a contribution to take advantage form ICT potential in the teaching of CE. The objectives underlying the main purpose of the project were defined according to literature review, which crosses three fundamental dimensions (scientific, pedagogical and technological). The project also benefited from the previous experience of the group and the collaboration with an European project (CROSSNET). The level of abstraction necessary for the understanding of the scientific model is pointed out as the major source of difficulties in the learning of CE, while also referred as a privileged target for the intervention of ICT. In this context, we introduce the expression "facilitating abstraction" to summarize the idea of supporting students' abstract thinking process during the learning of formal concepts. This idea has gained importance throughout the project leading to the development of a pedagogical approach to facilitate abstraction in the learning of CE. Although based on the use of ICT, the main purpose wasn't to introduce new digital resources in the saturated field of CE. Instead, the innovation resides in applying those resources in a properly planned approach, centred in promoting 'facilitated abstraction. The research model was designed in partnership with the CROSSNET project, consisting of the conduction of a case study for gathering information on the operation of the approach in classroom context (the major advantages, difficulties associated') Based on the results, a list of recommendations was established, as well as indicators for the upgrade of the resources used. Some hypotheses for further studies were also raised. The ultimate product of the project is the pedagogical approach that we refer to as 'FACE - Facilitating Abstraction in Chemical Equilibrium (learning), available online in Portuguese/English, uploaded on educational platforms based on Web 2.0. Keywords: Chemical Equilibrium, facilitated abstraction, digital resources, learning difficulties/ misconceptions, educational modules, case study, CROSSNET project. None None None None None None None None None None None None None None None

Surface Structure Dependence of SO 2 Interaction with Ceria Nanocrystals with Well-Defined Surface Facets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tumuluri, Uma; Li, Meijun; Cook, Brandon G.

2015-12-31

The effects of the surface structure of ceria (CeO2) on the nature, strength, and amount of species resulting from SO2 adsorption were studied using in situ IR and Raman spectroscopies coupled with mass spectrometry, along with first-principles calculations based on density functional theory (DFT). CeO2 nanocrystals with different morphologies, namely, rods (representing a defective structure), cubes (100 facet), and octahedra (111 facet), were used to represent different CeO2 surface structures. IR and Raman spectroscopic studies showed that the structure and binding strength of adsorbed species from SO2 depend on the shape of the CeO2 nanocrystals. SO2 adsorbs mainly as surfacemore » sulfites and sulfates at room temperature on CeO2 rods, cubes, and octahedra that were either oxidatively or reductively pretreated. The formation of sulfites is more evident on CeO2 octahedra, whereas surface sulfates are more prominent on CeO2 rods and cubes. This is explained by the increasing reducibility of the surface oxygen in the order octahedra < cubes < rods. Bulk sulfites are also formed during SO2 adsorption on reduced CeO2 rods. The formation of surface sulfites and sulfates on CeO2 cubes is in good agreement with our DFT results of SO2 interactions with the CeO2(100) surface. CeO2 rods desorb SO2 at higher temperatures than cubes and octahedra nanocrystals, but bulk sulfates are formed on CeO2 rods and cubes after high-temperature desorption whereas only some surface sulfates/sulfites are left on octahedra. This difference is rationalized by the fact that CeO2 rods have the highest surface basicity and largest amount of defects among the three nanocrystals, so they bind and react with SO2 strongly and are the most degraded after SO2 adsorption cycles. The fundamental understanding obtained in this work on the effects of the surface structure and defects on the interaction of SO2 with CeO2 provides insights for the design of more sulfur-resistant CeO2-based catalysts.« less

Surface Structure Dependence of SO 2 Interaction with Ceria Nanocrystals with Well-defined Surface Facets

DOE PAGES

Tumuluri, Uma; Li, Meijun; Cook, Brandon G.; ...

2015-12-02

The effects of the surface structure of ceria (CeO 2) on the nature, strength, and amount of species resulting from SO 2 adsorption were studied using in situ IR and Raman spectroscopies coupled with mass spectrometry, along with first-principles calculations based on density functional theory (DFT). CeO 2 nanocrystals with different morphologies, namely, rods (representing a defective structure), cubes (100 facet), and octahedra (111 facet), were used to represent different CeO 2 surface structures. IR and Raman spectroscopic studies showed that the structure and binding strength of adsorbed species from SO 2 depend on the shape of the CeO 2more » nanocrystals. SO 2 adsorbs mainly as surface sulfites and sulfates at room temperature on CeO 2 rods, cubes, and octahedra that were either oxidatively or reductively pretreated. The formation of sulfites is more evident on CeO 2 octahedra, whereas surface sulfates are more prominent on CeO 2 rods and cubes. This is explained by the increasing reducibility of the surface oxygen in the order octahedra < cubes < rods. Bulk sulfites are also formed during SO 2 adsorption on reduced CeO 2 rods. The formation of surface sulfites and sulfates on CeO 2 cubes is in good agreement with our DFT results of SO 2 interactions with the CeO 2(100) surface. CeO 2 rods desorb SO2 at higher temperatures than cubes and octahedra nanocrystals, but bulk sulfates are formed on CeO 2 rods and cubes after high-temperature desorption whereas only some surface sulfates/sulfites are left on octahedra. This difference is rationalized by the fact that CeO 2 rods have the highest surface basicity and largest amount of defects among the three nanocrystals, so they bind and react with SO 2 strongly and are the most degraded after SO 2 adsorption cycles. The fundamental understanding obtained in this work on the effects of the surface structure and defects on the interaction of SO 2 with CeO 2 provides insights for the design of more sulfur-resistant CeO 2-based catalysts.« less

Effects of amorphous silica coating on cerium oxide nanoparticles induced pulmonary responses.

PubMed

Ma, Jane; Mercer, Robert R; Barger, Mark; Schwegler-Berry, Diane; Cohen, Joel M; Demokritou, Philip; Castranova, Vincent

2015-10-01

Recently cerium compounds have been used in a variety of consumer products, including diesel fuel additives, to increase fuel combustion efficiency and decrease diesel soot emissions. However, cerium oxide (CeO2) nanoparticles have been detected in the exhaust, which raises a health concern. Previous studies have shown that exposure of rats to nanoscale CeO2 by intratracheal instillation (IT) induces sustained pulmonary inflammation and fibrosis. In the present study, male Sprague-Dawley rats were exposed to CeO2 or CeO2 coated with a nano layer of amorphous SiO2 (aSiO2/CeO2) by a single IT and sacrificed at various times post-exposure to assess potential protective effects of the aSiO2 coating. The first acellular bronchoalveolar lavage (BAL) fluid and BAL cells were collected and analyzed from all exposed animals. At the low dose (0.15mg/kg), CeO2 but not aSiO2/CeO2 exposure induced inflammation. However, at the higher doses, both particles induced a dose-related inflammation, cytotoxicity, inflammatory cytokines, matrix metalloproteinase (MMP)-9, and tissue inhibitor of MMP at 1day post-exposure. Morphological analysis of lung showed an increased inflammation, surfactant and collagen fibers after CeO2 (high dose at 3.5mg/kg) treatment at 28days post-exposure. aSiO2 coating significantly reduced CeO2-induced inflammatory responses in the airspace and appeared to attenuate phospholipidosis and fibrosis. Energy dispersive X-ray spectroscopy analysis showed Ce and phosphorous (P) in all particle-exposed lungs, whereas Si was only detected in aSiO2/CeO2-exposed lungs up to 3days after exposure, suggesting that aSiO2 dissolved off the CeO2 core, and some of the CeO2 was transformed to CePO4 with time. These results demonstrate that aSiO2 coating reduce CeO2-induced inflammation, phospholipidosis and fibrosis. Published by Elsevier Inc.

Quasi-zero-dimensional cobalt-doped CeO2 dots on Pd catalysts for alcohol electro-oxidation with enhanced poisoning-tolerance.

PubMed

Tan, Qiang; Zhu, Haiyan; Guo, Shengwu; Chen, Yuanzhen; Jiang, Tao; Shu, Chengyong; Chong, Shaokun; Hultman, Benjamin; Liu, Yongning; Wu, Gang

2017-08-31

Deactivation of an anode catalyst resulting from the poisoning of CO ad -like intermediates is one of the major problems for methanol and ethanol electro-oxidation reactions (MOR & EOR), and remains a grand challenge towards achieving high performance for direct alcohol fuel cells (DAFCs). Herein, we report a new approach for the preparation of ultrafine cobalt-doped CeO 2 dots (Co-CeO 2 , d = 3.6 nm), which can be an effective anti-poisoning promoter for Pd catalysts towards MOR and EOR in alkaline media. Compared to Pd/CeO 2 and pure Pd, the hybrid Pd/Co-CeO 2 nanocomposite catalyst exhibited a much enhanced activity and remarkable anti-poisoning ability for both MOR and EOR. The nanocomposite catalyst showed much higher mass activity (4×) than a state-of-the-art PtRu catalyst. The promotional mechanism was elucidated using extensive characterization and density-functional theory (DFT). A bifunctional effect of the Co-CeO 2 dots was discovered to be due to (i) an enhanced electronic interaction between Co-CeO 2 and Pd dots and (ii) the increased oxygen storage capacity of Co-CeO 2 dots to facilitate the oxidation of CO ad . Therefore, the Pd/Co-CeO 2 nanocomposite appears to be a promising catalyst for advanced DAFCs with low cost and high performance.

Heterogeneous catalytic ozonation of clofibric acid using Ce/MCM-48: Preparation, reaction mechanism, comparison with Ce/MCM-41.

PubMed

Li, Shangyi; Tang, Yiming; Chen, Weirui; Hu, Zhe; Li, Xukai; Li, Laisheng

2017-10-15

Three-dimensional mesoporous MCM-48 and Ce loaded MCM-48 (Ce/MCM-48) were synthesized by hydrothermal and impregnating methods, respectively. They were characterized by XRD, SEM, TEM, EDS, XPS, N 2 adsorption-desorption techniques, and the results showed that Ce/MCM-48 still retained a highly ordered cubic structure. A series of experiments were conducted to study the catalytic activity of Ce/MCM-48 and Ce/MCM-41 for ozonation of clofibric acid in aqueous solution. Total Organic Carbon (TOC) removal efficiency in Ce/MCM-48/O 3 can be improved to 64% at 120min reaction time, 54% by Ce/MCM-41/O 3 , only 24% by MCM-48/O 3 , 23% by single ozonation. Ce/MCM-48 did not show any adsorption capacity for CA. Effect of initial pH revealed that active sites were surface protonated hydroxyl groups. The restraint of phosphate and sodium hydrogen sulfite (NaHSO 3 ) on the mineralization of CA illustrated more hydroxyl radicals were generated by Ce/MCM-48 catalysts than Ce/MCM-41. The degradation pathway of CA was investigated by the alterations of pH under different conditions. Recycle tests of catalysts demonstrated that compared with Ce/MCM-41, Ce/MCM-48 exhibited more excellent catalytic efficiency and stability because of its unique pore systems. Copyright © 2017 Elsevier Inc. All rights reserved.

Gastroprotective activity of the chloroform extract of the roots from Arctium lappa L.

PubMed

Dos Santos, Ana C; Baggio, Cristiane H; Freitas, Cristina S; Lepieszynski, Juliana; Mayer, Bárbara; Twardowschy, André; Missau, Fabiana C; dos Santos, Elide P; Pizzolatti, Moacir G; Marques, Maria C A

2008-06-01

Arctium lappa L. is used in folk medicine as a diuretic, depurative and digestive stimulant and in dermatological conditions. The objective of this study was to evaluate the effect and the possible mechanisms involved in the gastroprotective effects of a chloroform extract (CE) of the roots from A. lappa and its fractions. Oral pretreatment with CE (10, 30 and 100 mg kg(-1)) significantly reduced gastric lesions induced by ethanol by 61%, 70% and 76%, respectively. Oral administration of CE (100 mg kg(-1) per day for 7 days) reduced the chronic gastric ulceration induced by acetic acid by 52%. Intraduodenal CE (100, 300 and 600 mg kg(-1)) reduced the total acidity of gastric secretion by 22%, 22% and 33%, respectively, while i.p. administration (10, 30 and 100 mg kg(-1)) inhibited total acidity by 50%, 60% and 67%, respectively. In-vitro, CE inhibited H+, K+ -ATPase activity with an EC50 of 53 microgmL(-1) and fraction A (30 and 100 microgmL(-1)) reduced this by 48% and 89%, respectively. CE had no effect on gastrointestinal motility. CE (250 microgmL(-1)) and fraction B (100 and 250 microgmL(-1)) had free-radical scavenging ability, inhibiting 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical activity by 50%, 20% and 55%, respectively. Collectively, the results show that the CE protects animals from gastric lesions by reducing gastric acid secretion via inhibition of gastric H+, K+ -ATPase.

The effect of amorphous selenium detector thickness on dual-energy digital breast imaging

PubMed Central

Hu, Yue-Houng; Zhao, Wei

2014-01-01

Purpose: Contrast enhanced (CE) imaging techniques for both planar digital mammography (DM) and three-dimensional (3D) digital breast tomosynthesis (DBT) applications requires x-ray photon energies higher than the k-edge of iodine (33.2 keV). As a result, x-ray tube potentials much higher (>40 kVp) than those typical for screening mammography must be utilized. Amorphous selenium (a-Se) based direct conversion flat-panel imagers (FPI) have been widely used in DM and DBT imaging systems. The a-Se layer is typically 200 μm thick with quantum detective efficiency (QDE) >87% for x-ray energies below 26 keV. However, QDE decreases substantially above this energy. To improve the object detectability of either CE-DM or CE-DBT, it may be advantageous to increase the thickness (dSe) of the a-Se layer. Increasing the dSe will improve the detective quantum efficiency (DQE) at the higher energies used in CE imaging. However, because most DBT systems are designed with partially isocentric geometries, where the gantry moves about a stationary detector, the oblique entry of x-rays will introduce additional blur to the system. The present investigation quantifies the effect of a-Se thickness on imaging performance for both CE-DM and CE-DBT, discussing the effects of improving photon absorption and blurring from oblique entry of x-rays. Methods: In this paper, a cascaded linear system model (CLSM) was used to investigate the effect of dSe on the imaging performance (i.e., MTF, NPS, and DQE) of FPI in CE-DM and CE-DBT. The results from the model are used to calculate the ideal observer signal-to-noise ratio, d′, which is used as a figure-of-merit to determine the total effect of increasing dSe for CE-DM and CE-DBT. Results: The results of the CLSM show that increasing dSe causes a substantial increase in QDE at the high energies used in CE-DM. However, at the oblique projection angles used in DBT, the increased length of penetration through a-Se introduces additional image blur. The reduced MTF and DQE at high spatial frequencies lead to reduced two-dimensional d′. These losses in projection image resolution may subsequently result in a decrease in the 3D d′, but the degree of which is largely dependent on the DBT reconstruction algorithm. For a filtered backprojection (FBP) algorithm with spectral apodization and slice-thickness filters, which dominate the blur for reconstructed images at oblique angles, the effect of oblique entry of x-rays on 3D d′ is minimal. Thus, increasing dSe results in an improvement in d′ for both CE-DM and CE-DBT with typical FBP reconstruction parameters. Conclusions: Increased dSe improves CE breast imaging performance by increasing QDE of detectors at higher energies, e.g., 49 kVp. Although there is additional blur in the oblique angled projections of a DBT scan, the overall 3D d′ for DBT is not degraded because the dominant source blur at these angles results from the reconstruction filters of the employed FBP algorithm. PMID:25370637

The effect of amorphous selenium detector thickness on dual-energy digital breast imaging.

PubMed

Hu, Yue-Houng; Zhao, Wei

2014-11-01

Contrast enhanced (CE) imaging techniques for both planar digital mammography (DM) and three-dimensional (3D) digital breast tomosynthesis (DBT) applications requires x-ray photon energies higher than the k-edge of iodine (33.2 keV). As a result, x-ray tube potentials much higher (>40 kVp) than those typical for screening mammography must be utilized. Amorphous selenium (a-Se) based direct conversion flat-panel imagers (FPI) have been widely used in DM and DBT imaging systems. The a-Se layer is typically 200 μm thick with quantum detective efficiency (QDE) >87% for x-ray energies below 26 keV. However, QDE decreases substantially above this energy. To improve the object detectability of either CE-DM or CE-DBT, it may be advantageous to increase the thickness (dSe) of the a-Se layer. Increasing the dSe will improve the detective quantum efficiency (DQE) at the higher energies used in CE imaging. However, because most DBT systems are designed with partially isocentric geometries, where the gantry moves about a stationary detector, the oblique entry of x-rays will introduce additional blur to the system. The present investigation quantifies the effect of a-Se thickness on imaging performance for both CE-DM and CE-DBT, discussing the effects of improving photon absorption and blurring from oblique entry of x-rays. In this paper, a cascaded linear system model (CLSM) was used to investigate the effect of dSe on the imaging performance (i.e., MTF, NPS, and DQE) of FPI in CE-DM and CE-DBT. The results from the model are used to calculate the ideal observer signal-to-noise ratio, d', which is used as a figure-of-merit to determine the total effect of increasing dSe for CE-DM and CE-DBT. The results of the CLSM show that increasing dSe causes a substantial increase in QDE at the high energies used in CE-DM. However, at the oblique projection angles used in DBT, the increased length of penetration through a-Se introduces additional image blur. The reduced MTF and DQE at high spatial frequencies lead to reduced two-dimensional d'. These losses in projection image resolution may subsequently result in a decrease in the 3D d', but the degree of which is largely dependent on the DBT reconstruction algorithm. For a filtered backprojection (FBP) algorithm with spectral apodization and slice-thickness filters, which dominate the blur for reconstructed images at oblique angles, the effect of oblique entry of x-rays on 3D d' is minimal. Thus, increasing dSe results in an improvement in d' for both CE-DM and CE-DBT with typical FBP reconstruction parameters. Increased dSe improves CE breast imaging performance by increasing QDE of detectors at higher energies, e.g., 49 kVp. Although there is additional blur in the oblique angled projections of a DBT scan, the overall 3D d' for DBT is not degraded because the dominant source blur at these angles results from the reconstruction filters of the employed FBP algorithm.

Human cystic echinococcosis in Heilongjiang Province, China: a retrospective study.

PubMed

Zhang, Tiemin; Zhao, Wei; Yang, Dong; Piao, Daxun; Huang, Shibo; Mi, Yuanyuan; Zhao, Xianqi; Cao, Jianping; Shen, Yujuan; Zhang, Weizhe; Liu, Aiqin

2015-03-10

Cystic echinococcosis (CE) is one of emerging zoonotic parasitic diseases throughout the world, having significant medical and economic importance in developing countries. The western and northwestern China is considered as CE endemic areas. In northeastern China's Heilongjiang Province, the increasing number of sporadic human CE cases has attracted more and more attention. The aims of the present study were to understand the clinical characteristics of human CE in the investigated area and to compare the coincidence rates of CT, ultrasound and serological test against the histopathology results among CE patients. Hospital data of 183 human CE cases in the period from January 2004 to July 2013 were collected from the two largest hospitals in Heilongjiang Province. Clinical data were analyzed, including age, gender, occupation and living residence of CE patients and localization, size and number of CE cysts as well as the diagnosis methods of CE before operation. The results revealed that the incidence of CE reached a peak in the age group of 41-50 years. Among the 183 CE patients, the females were observed to have a higher percentage of CE patients (60.66%, 111/183) than males (39.34%, 72/183). The majority of CE patients were farmers, followed by workers, employees, public servants, students and so on. CE cysts were most commonly found in the livers, with a 30 cm cyst in diameter being detected. CT showed the highest coincidence rate (96.64%) for hepatic CE among the three common diagnosis methods (CT, ultrasound imagine and serological test) compared against the histopathology results. This is the first retrospective analysis of human CE cases in Heilongjiang Province in recent ten years. Clinical characteristics of human CE were described here. CT appeared to be the most effective diagnosis method for hepatic CE.

Single crystal and optical ceramic multicomponent garnet scintillators: A comparative study

NASA Astrophysics Data System (ADS)

Wu, Yuntao; Luo, Zhaohua; Jiang, Haochuan; Meng, Fang; Koschan, Merry; Melcher, Charles L.

2015-04-01

Multicomponent garnet materials can be made in optical ceramic as well as single crystal form due to their cubic crystal structure. In this work, high-quality Gd3Ga3Al2O12:0.2 at% Ce (GGAG:Ce) single crystal and (Gd,Lu)3Ga3Al2O12:1 at% Ce (GLuGAG:Ce) optical ceramics were fabricated by the Czochralski method and a combination of hot isostatic pressing (HIPing) and annealing treatment, respectively. Under optical and X-ray excitation, the GLuGAG:Ce optical ceramic exhibits a broad Ce3+ transition emission centered at 550 nm, while the emission peak of the GGAG:Ce single crystal is centered at 540 nm. A self-absorption effect in GLuGAG:Ce optical ceramic results in this red-shift of the Ce3+ emission peak compared to that in the GGAG:Ce single crystal. The light yield under 662 keV γ-ray excitation was 45,000±2500 photons/MeV and 48,200±2410 photons/MeV for the GGAG:Ce single crystal and GLuGAG:Ce optical ceramic, respectively. An energy resolution of 7.1% for 662 keV γ-rays was achieved in the GLuGAG:Ce optical ceramic with a Hamamatsu R6231 PMT, which is superior to the value of 7.6% for a GGAG:Ce single crystal. Scintillation decay time measurements under 137Cs irradiation show two exponential decay components of 58 ns (47%) and 504 ns (53%) for the GGAG:Ce single crystal, and 84 ns (76%) and 148 ns (24%) for the GLuGAG:Ce optical ceramic. The afterglow level after X-ray cutoff in the GLuGAG:Ce optical ceramic is at least one order of magnitude lower than in the GGAG:Ce single crystal.

The Influence of Arc-Flash and Fire-Resistant Clothing on Thermoregulation during Exercise in the Heat.

PubMed

Poirier, Martin P; Meade, Robert D; McGinn, Ryan; Friesen, Brian J; Hardcastle, Stephen G; Flouris, Andreas D; Kenny, Glen P

2015-01-01

We evaluated the effect of arc-flash and fire-resistant (AFR) clothing ensembles (CE) on whole-body heat dissipation during work in the heat. On 10 occasions, 7 males performed four 15-min cycling bouts at a fixed rate of metabolic heat production (400 W) in the heat (35°C), each separated by 15-min of recovery. Whole-body heat loss and metabolic heat production were measured by direct and indirect calorimetry, respectively. Body heat storage was calculated as the temporal summation of heat production and heat loss. Responses were compared in a semi-nude state and while wearing two CE styles: (1) single-piece (coveralls) and (2) two-piece (workpant + long-sleeve shirt). For group 1, there was one non-AFR single-piece CE (CE1STD) and three single-piece CE with AFR properties (CE2AFR, CE3AFR, CE4AFR). For group 2, there was one non-AFR two-piece CE (CE5STD) and four two-piece CE with AFR properties (CE6AFR, CE7AFR, CE8AFR, CE9AFR). The workpants for CE6AFR were not AFR-rated, while a cotton undershirt was also worn for conditions CE8AFR and CE9AFR and for all single-piece CE. Heat storage for all conditions (CE1STD: 328 ± 55, CE2AFR: 335 ± 87, CE3AFR: 309 ± 95, CE4AFR: 403 ± 104, CE5STD: 253 ± 78, CE6AFR: 268 ± 89, CE7AFR: 302 ± 70, CE8AFR: 360 ± 36, CE9AFR: 381 ± 99 kJ) was greater than the semi-nude state (160 ± 124 kJ) (all p ≤ 0.05). No differences were measured between single-piece uniforms (p = 0.273). Among the two-piece uniforms, heat storage was greater for CE8AFR and CE9AFR relative to CE5STD and CE6AFR (all p ≤ 0.05), but not CE7AFR (both p > 0.05). Differences between clothing styles were measured such that greater heat storage was observed in both CE1STD and CE2-4AFR relative to CE5STD. Further, heat storage was greater in CE2AFR and CE4AFR relative to CE6AFR, while it was greater in CE4AFR compared to CE7AFR. Body heat storage during work in the heat was not influenced by the use of AFR fabrics in the single- or two-piece uniforms albeit less heat was stored in the two-piece uniforms when no undershirt was worn. However, heat storage was comparable between clothing styles when an undershirt was worn with the two-piece uniform.

Stress-State Effects on Strength and Fracture of Partially-Stabilized Zirconia

DTIC Science & Technology

1994-03-01

Ceramics and Test Procedures (1) Ce-TZP/AI 2 0 3 Ceramics A Ce-TZP/A120 3 powder of the nominal composition, 88 wt % of Ce-TZP (12 mol % CeO2 and 88...mol % ZrO2) and 10 wt % A120 3 and 2 wt % of proprietary dopants was obtained from a commercial source#. Billets of the Ce-TZP/A120 3 were prepared by...34Metastability of the Martensitic Transformation in a 12 mol % Ceria-Zirconia Alloy : 1, Deformation and Fracture Observations," J. Am. Ceram. Soc

Ce3+-ion-induced visible-light photocatalytic degradation and electrochemical activity of ZnO/CeO2 nanocomposite

PubMed Central

Rajendran, Saravanan; Khan, Mohammad Mansoob; Gracia, F.; Qin, Jiaqian; Gupta, Vinod Kumar; Arumainathan, Stephen

2016-01-01

In this study, pure ZnO, CeO2 and ZnO/CeO2 nanocomposites were synthesized using a thermal decomposition method and subsequently characterized using different standard techniques. High-resolution X-ray photoelectron spectroscopy measurements confirmed the oxidation states and presence of Zn2+, Ce4+, Ce3+ and different bonded oxygen species in the nanocomposites. The prepared pure ZnO and CeO2 as well as the ZnO/CeO2 nanocomposites with various proportions of ZnO and CeO2 were tested for photocatalytic degradation of methyl orange, methylene blue and phenol under visible-light irradiation. The optimized and highly efficient ZnO/CeO2 (90:10) nanocomposite exhibited enhanced photocatalytic degradation performance for the degradation of methyl orange, methylene blue, and phenol as well as industrial textile effluent compared to ZnO, CeO2 and the other investigated nanocomposites. Moreover, the recycling results demonstrate that the ZnO/CeO2 (90:10) nanocomposite exhibited good stability and long-term durability. Furthermore, the prepared ZnO/CeO2 nanocomposites were used for the electrochemical detection of uric acid and ascorbic acid. The ZnO/CeO2 (90:10) nanocomposite also demonstrated the best detection, sensitivity and performance among the investigated materials in this application. These findings suggest that the synthesized ZnO/CeO2 (90:10) nanocomposite could be effectively used in various applications. PMID:27528264

Interactions of soil-derived dissolved organic matter with phenol in peroxidase-catalyzed oxidative coupling reactions.

PubMed

Huang, Qingguo; Weber, Walter J

2004-01-01

The influence of dissolved soil organic matter (DSOM) derived from three geosorbents of different chemical composition and diagenetic history on the horseradish peroxidase (HRP) catalyzed oxidative coupling reactions of phenol was investigated. Phenol conversion and precipitate-product formation were measured, respectively, by HPLC and radiolabeled species analysis. Fourier transform infrared (FTIR) spectroscopy and capillary electrophoresis (CE) were used to characterize the products of enzymatic coupling, and the acute toxicities of the soluble products were determined by Microtox assay. Phenol conversion and precipitate formation were both significantly influenced by cross-coupling of phenol with dissolved organic matter, particularly in the cases of the more reactive and soluble DSOMs derived from two diagenetically "young" humic-type geosorbents. FTIR and CE characterizations indicate that enzymatic cross-coupling in these two cases leads to incorporation of phenol in DSOM macromolecules, yielding nontoxic soluble products. Conversely, cross-coupling appears to proceed in parallel with self-coupling in the presence of the relatively inert and more hydrophobic DSOM derived from a diagenetically "old" kerogen-type shale material. The products formed in this system have lower solubility and precipitate more readily, although their soluble forms tend to be more toxic than those formed by dominant cross-coupling reactions in the humic-type DSOM solutions. Several of the findings reported may be critically important with respect to feasibility evaluations and the engineering design of associated remediation schemes.

What makes community engagement effective?: Lessons from the Eliminate Dengue Program in Queensland Australia.

PubMed

Kolopack, Pamela A; Parsons, Janet A; Lavery, James V

2015-04-01

Worldwide, more than 40% of the population is at risk from dengue and recent estimates suggest that up to 390 million dengue infections are acquired every year. The Eliminate Dengue (ED) Program is investigating the use of Wolbachia-infected, transmission-compromised, mosquitoes to reduce dengue transmission. Previous introductions of genetically-modified strategies for dengue vector control have generated controversy internationally by inadequately engaging host communities. Community Engagement (CE) was a key component of the ED Program's initial open release trials in Queensland Australia. Their approach to CE was perceived as effective by the ED team's senior leadership, members of its CE team, and by its funders, but if and why this was the case was unclear. We conducted a qualitative case study of the ED Program's approach to CE to identify and critically examine its components, and to explain whether and how these efforts contributed to the support received by stakeholders. In-depth semi-structured interviews were conducted with 24 participants with a range of experiences and perspectives related to the ED Program's CE activities. Our analytic approach combined techniques of grounded theory and qualitative description. The ED Program's approach to CE reflected four foundational features: 1) enabling conditions; 2) leadership; 3) core commitments and guiding values; and 4) formative social science research. These foundations informed five key operational practices: 1) building the CE team; 2) integrating CE into management practices; 3) discerning the community of stakeholders; 4) establishing and maintaining a presence in the community; and 5) socializing the technology and research strategy. We also demonstrate how these practices contributed to stakeholders' willingness to support the trials. Our case study has identified, and explained the functional relationships among, the critical features of the ED Program's approach to CE. It has also illuminated how these features were meaningful to stakeholders and contributed to garnering support within the host communities for the open-release trials. Our findings reveal how translating ethical intentions into effective action is more socially complex than is currently reflected in the CE literature. Because our case study delineates the critical features of the ED Program's approach to CE, it can serve as a framework for other programs to follow when designing their own strategies. And because the findings outline a theory of change for CE, it can also serve as a starting point for developing an evaluation framework for CE.

Crystal Growth and Scintillation Properties of Ce Doped Gd3Ga,Al5O12 Single Crystals

NASA Astrophysics Data System (ADS)

Kamada, Kei; Yanagida, Takayuki; Pejchal, Jan; Nikl, Martin; Endo, Takanori; Tsutsumi, Kousuke; Fujimoto, Yutaka; Fukabori, Akihiro; Yoshikawa, Akira

2012-10-01

Ce1%, 2% and 3% doped Gd3(Ga,Al)5O12 (GAGG) single crystals were grown by the Cz method. Luminescence and scintillation properties were measured. Light yield change along the growth direction and effects of Ce concentration on scintillation properties in Ce:GAGG were studied. Ce3+ 5d-4f emission within 520-530 nm was observed in the Ce:GAGG crystals. The Ce1%:GAGG sample with 3×3×1 mm size showed the highest light yield of 46000 photon/MeV. The energy resolution was 7.8%@662 keV. With increasing solidification fraction, the LY were decreased. It is proposed that the increase of Ga concentration along the growth direction is the main cause of the decrease of LY. The scintillation decay times were accelerated with increasing Ce concentration in the Ce:GAGG crystals. The scintillation decay times were 92.0 ns, 79.1 ns and 68.3 ns in the Ce1, 2 and 3% GAGG, respectively.

Pd(0)-CMC@Ce(OH)(4) organic/inorganic hybrid as highly active catalyst for the Suzuki-Miyaura reaction.

PubMed

Lin, Bijin; Liu, Xiaoping; Zhang, Zhuan; Chen, Yang; Liao, Xiaojian; Li, Yiqun

2017-07-01

A very easy sequential metathesis for the synthesis of Pd(II)-CMC@Ce(OH) 4 organic/inorganic hybrid and its application as effective pre-catalyst for the Suzuki-Miyaura reaction have been reported. It was found that the Pd nanoparticles (Pd NPs) were formed in situ in the course of the Suzuki-Miyaura couplings when Pd(II)-CMC@Ce(OH) 4 was used as a pre-catalyst. The activity of the Pd NPs in the reaction was enhanced synergistically by the unique redox properties (Ce 3+ /Ce 4+ ) of Ce(OH) 4 and coordination with carboxyl groups as well as free hydroxyl groups of the hybrid of CMC@Ce(OH) 4 . The results exhibit the Pd(0)-CMC@Ce(OH) 4 is super over Pd(II)@CMC, Pd(II)@CeO 2 , and Pd(II)@Ce(OH) 4 catalysts in the Suzuki-Miyaura reaction. Moreover, the catalyst could be easily separated by simple filtration and reused at least seven runs without losing its activity. Copyright © 2017 Elsevier Inc. All rights reserved.

Preparation and Oxidation Performance of Y and Ce-Modified Cr Coating on open-cell Ni-Cr-Fe Alloy Foam by the Pack Cementation

NASA Astrophysics Data System (ADS)

Pang, Q.; Hu, Z. L.; Wu, G. H.

2016-12-01

Metallic foams with a high fraction of porosity, low density and high-energy absorption capacity are a rapidly emerging class of novel ultralight weight materials for various engineering applications. In this study, Y-Cr and Ce-Cr-coated Ni-Cr-Fe alloy foams were prepared via the pack cementation method, and the effects of Y and Ce addition on the coating microstructure and oxidation performance were analyzed in order to improve the oxidation resistance of open-cell nickel-based alloy foams. The results show that the Ce-Cr coating is relatively more uniform and has a denser distribution on the surface of the nickel-based alloy foam. The surface grains of the Ce-Cr-coated alloy foam are finer compared to those of the Y-Cr-coated alloy foam. An obvious Ce peak appears on the interface between the coating and the alloy foam strut, which gives rise to a "site-blocking" effect for the short-circuit transport of the cation in the substrate. X-ray diffraction analysis shows that the Y-Cr-coated alloy foam mainly consists of Cr, (Fe, Ni) and (Ni, Cr) phases in the surface layer. The Ce-Cr-coated alloy foam is mainly composed of Cr and (Ni, Cr) phases. Furthermore, the addition of Y and Ce clearly lead to an improvement in the oxidation resistance of the coated alloy foams in the temperature range of 900-1000 °C. The addition of Ce is especially effective in enhancing the diffusion of chromium to the oxidation front, thus, accelerating the formation of a Cr2O3 layer.

Evaluating the drivers of and obstacles to the willingness to use cognitive enhancement drugs: the influence of drug characteristics, social environment, and personal characteristics.

PubMed

Sattler, Sebastian; Mehlkop, Guido; Graeff, Peter; Sauer, Carsten

2014-02-01

The use of cognitive enhancement (CE) by means of pharmaceutical agents has been the subject of intense debate both among scientists and in the media. This study investigates several drivers of and obstacles to the willingness to use prescription drugs non-medically for augmenting brain capacity. We conducted a web-based study among 2,877 students from randomly selected disciplines at German universities. Using a factorial survey, respondents expressed their willingness to take various hypothetical CE-drugs; the drugs were described by five experimentally varied characteristics and the social environment by three varied characteristics. Personal characteristics and demographic controls were also measured. We found that 65.3% of the respondents staunchly refused to use CE-drugs. The results of a multivariate negative binomial regression indicated that respondents' willingness to use CE-drugs increased if the potential drugs promised a significant augmentation of mental capacity and a high probability of achieving this augmentation. Willingness decreased when there was a high probability of side effects and a high price. Prevalent CE-drug use among peers increased willingness, whereas a social environment that strongly disapproved of these drugs decreased it. Regarding the respondents' characteristics, pronounced academic procrastination, high cognitive test anxiety, low intrinsic motivation, low internalization of social norms against CE-drug use, and past experiences with CE-drugs increased willingness. The potential severity of side effects, social recommendations about using CE-drugs, risk preferences, and competencies had no measured effects upon willingness. These findings contribute to understanding factors that influence the willingness to use CE-drugs. They support the assumption of instrumental drug use and may contribute to the development of prevention, policy, and educational strategies.

Evaluating the drivers of and obstacles to the willingness to use cognitive enhancement drugs: the influence of drug characteristics, social environment, and personal characteristics

PubMed Central

2014-01-01

Background The use of cognitive enhancement (CE) by means of pharmaceutical agents has been the subject of intense debate both among scientists and in the media. This study investigates several drivers of and obstacles to the willingness to use prescription drugs non-medically for augmenting brain capacity. Methods We conducted a web-based study among 2,877 students from randomly selected disciplines at German universities. Using a factorial survey, respondents expressed their willingness to take various hypothetical CE-drugs; the drugs were described by five experimentally varied characteristics and the social environment by three varied characteristics. Personal characteristics and demographic controls were also measured. Results We found that 65.3% of the respondents staunchly refused to use CE-drugs. The results of a multivariate negative binomial regression indicated that respondents’ willingness to use CE-drugs increased if the potential drugs promised a significant augmentation of mental capacity and a high probability of achieving this augmentation. Willingness decreased when there was a high probability of side effects and a high price. Prevalent CE-drug use among peers increased willingness, whereas a social environment that strongly disapproved of these drugs decreased it. Regarding the respondents’ characteristics, pronounced academic procrastination, high cognitive test anxiety, low intrinsic motivation, low internalization of social norms against CE-drug use, and past experiences with CE-drugs increased willingness. The potential severity of side effects, social recommendations about using CE-drugs, risk preferences, and competencies had no measured effects upon willingness. Conclusions These findings contribute to understanding factors that influence the willingness to use CE-drugs. They support the assumption of instrumental drug use and may contribute to the development of prevention, policy, and educational strategies. PMID:24484640

Living target of Ce(III) action on horseradish cells: proteins on/in cell membrane.

PubMed

Yang, Guangmei; Sun, Zhaoguo; Lv, Xiaofen; Deng, Yunyun; Zhou, Qing; Huang, Xiaohua

2012-12-01

Positive and negative effects of rare earth elements (REEs) in life have been reported in many papers, but the cellular mechanisms have not been answered, especially the action sites of REEs on plasma membrane are unknown. Proteins on/in the plasma membrane perform main functions of the plasma membrane. Cerium (Ce) is the richest REEs in crust. Thus, the interaction between Ce(III) and the proteins on/in the plasma membrane, the morphology of protoplast, and the contents of nutrient elements in protoplast of horseradish were investigated using the optimized combination of the fluorescence microscopy, fluorescence spectroscopy, circular dichroism, scanning electron microscopy, and X-ray energy dispersive spectroscopy. It was found that Ce(III) at the low concentrations (10, 30 μM) could interact with proteins on/in the plasma membrane of horseradish, leading to the improvement in the structure of membrane proteins and the plasma membrane, which accelerated the intra-/extra-cellular substance exchange and further promoted the development of cells. When horseradish was treated with Ce(III) at the high concentrations (60, 80 μM), Ce(III) also could interact with the proteins on/in the plasma membrane of horseradish, leading to the destruction in the structure of membrane proteins and the plasma membrane. These effects decelerated the intra-/extra-cellular substance exchange and further inhibited the development of cells. Thus, the interaction between Ce(III) and proteins on/in the plasma membrane in plants was an important reason of the positive and negative effects of Ce(III) on plants. The results would provide some references for understanding the cellular effect mechanisms of REEs on plants.

Neuropeptide Y in the central nucleus of amygdala regulates the anxiolytic effect of agmatine in rats.

PubMed

Taksande, Brijesh G; Kotagale, Nandkishor R; Gawande, Dinesh Y; Bharne, Ashish P; Chopde, Chandrabhan T; Kokare, Dadasaheb M

2014-06-01

In the present study, modulation of anxiolytic action of agmatine by neuropeptide Y (NPY) in the central nucleus of amygdala (CeA) is evaluated employing Vogel's conflict test (VCT) in rats. The intra-CeA administration of agmatine (0.6 and 1.2µmol/rat), NPY (10 and 20pmol/rat) or NPY Y1/Y5 receptors agonist [Leu(31), Pro(34)]-NPY (30 and 60pmol/rat) significantly increased the number of punished drinking licks following 15min of treatment. Combination treatment of subeffective dose of NPY (5pmol/rat) or [Leu(31), Pro(34)]-NPY (15pmol/rat) and agmatine (0.3µmol/rat) produced synergistic anxiolytic-like effect. However, intra-CeA administration of selective NPY Y1 receptor antagonist, BIBP3226 (0.25 and 0.5mmol/rat) produced anxiogenic effect. In separate set of experiment, pretreatment with BIBP3226 (0.12mmol/rat) reversed the anxiolytic effect of agmatine (0.6µmol/rat). Furthermore, we evaluated the effect of intraperitoneal injection of agmatine (40mg/kg) on NPY-immunoreactivity in the nucleus accumbens shell (AcbSh), lateral part of bed nucleus of stria terminalis (BNSTl) and CeA. While agmatine treatment significantly decreased the fibers density in BNSTl, increase was noticed in AcbSh. In addition, agmatine reduced NPY-immunoreactive cells in the AcbSh and CeA. Immunohistochemical data suggest the enhanced transmission of NPY from the AcbSh and CeA. Taken together, this study suggests that agmatine produced anxiolytic effect which might be regulated via modulation of NPYergic system particularly in the CeA. Copyright © 2013 Elsevier B.V. and ECNP. All rights reserved.

Lung lavage therapy to lessen the biological effects of inhaled sup 144 Ce in dogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muggenburg, B.A.; Boecker, B.B.; Hahn, F.F.

1990-11-01

To evaluate the therapeutic effects of removal of an internally deposited radionuclide on long-term biological effects, lung lavage was used to treat dogs that had inhaled 144Ce in a relatively insoluble form, in fused aluminosilicate particles. Either 10 lung lavages were performed between Days 2 and 56 after exposure or 20 lung lavages were performed between Days 2 and 84 after exposure. Approximately one-half of the 144Ce was removed by the lavages, resulting in a corresponding reduction in the total absorbed beta dose to lung. The mean survival time of the treated dogs was 1270 days compared to 370 daysmore » for untreated dogs whose initial pulmonary burdens of 144Ce were similar. Treated dogs died late from cancers of the lung or liver, whereas the untreated dogs died at much earlier times from radiation pneumonitis. Dogs treated with lung lavage but not exposed to 144Ce had a mean survival of 4770 days. We concluded that removal of 144Ce from the lung by lavage resulted in increased survival time and in a change in the biological effects from inhaled 144Ce from early-occurring inflammatory disease to late-occurring effects, principally cancer. In addition, the biological effects occurring in the treated dogs could be better predicted from the total absorbed beta dose in the lung and the dose rate after treatment rather than from the original dose rate to the lung. Therefore, we concluded that prompt treatment to remove radioactive materials could be of significant benefit to persons accidentally exposed to high levels of airborne, relatively insoluble, radioactive particles.« less

Effect of Ga addition on the valence state of Ce and magnetic properties of melt-spun Ce17Fe78-xB6Gax (x = 0-1.0) ribbons

NASA Astrophysics Data System (ADS)

Jiang, Qingzheng; Zhong, Minglong; Lei, Weikai; Zeng, Qingwen; Hu, Yongfeng; Quan, Qichen; Xu, Yaping; Hu, Xianjun; Zhang, Lili; Liu, Renhui; Ma, Shengcan; Zhong, Zhenchen

2017-08-01

The Ce17Fe78-xB6Gax (x=0-1.0) ribbons were fabricated by a melt-spinning technique in order to study the mechanism of the valence variation of Ce and their magnetic properties as well as improve the thermal stability of Ce-based rare earth permanent magnets. The systematic investigations of the Ce17Fe78-xB6Gax (x=0-1.0) alloys show that the room-temperature coercivity increases significantly from 352 kA/m at x = 0 to 492 kA/m at x = 1.0. The Curie temperature (Tc) increases monotonically from 424.5 K to 433.6 K, and the temperature coefficients of remanence (α) and coercivity (β) of the ribbons are better off from -0.56 %/K, -0.75 %/K for x = 0 to -0.45 %/K, -0.65 %/K for x = 0.75 in the temperature range of 300-400 K, respectively. The Ce L3-edge X-ray absorption near edge structure (XANES) spectrums reveal that there is more Ce4+ in ribbons under total electron yield than fluorescence yield as Ce has a high affinity with oxygen. The weight of Ce3+ increases while the weight of Ce4+ decreases in Ga-added alloys. The refined grain size and a more uniform microstructure are mainly attributed to the improved magnetic properties and thermal stability with Ga doping. This paper may serve as a reference for further developing the so-called gap magnets and the effective utilization of the rare earth resources.

Enhanced Antitumor Effects of Epidermal Growth Factor Receptor Targetable Cetuximab-Conjugated Polymeric Micelles for Photodynamic Therapy.

PubMed

Chang, Ming-Hsiang; Pai, Chin-Ling; Chen, Ying-Chen; Yu, Hsiu-Ping; Hsu, Chia-Yen; Lai, Ping-Shan

2018-02-22

Nanocarrier-based delivery systems are promising strategies for enhanced therapeutic efficacy and safety of toxic drugs. Photodynamic therapy (PDT)-a light-triggered chemical reaction that generates localized tissue damage for disease treatments-usually has side effects, and thus patients receiving photosensitizers should be kept away from direct light to avoid skin phototoxicity. In this study, a clinically therapeutic antibody cetuximab (C225) was conjugated to the surface of methoxy poly(ethylene glycol)- b -poly(lactide) (mPEG- b -PLA) micelles via thiol-maleimide coupling to allow tumor-targetable chlorin e6 (Ce6) delivery. Our results demonstrate that more C225-conjugated Ce6-loaded polymeric micelles (C225-Ce6/PM) were selectively taken up than Ce6/PM or IgG conjugated Ce6/PM by epidermal growth factor receptor (EGFR)-overexpressing A431 cells observed by confocal laser scanning microscopy (CLSM), thereby decreasing the IC 50 value of Ce6-mediated PDT from 0.42 to 0.173 μM. No significant differences were observed in cellular uptake study or IC 50 value between C225-Ce6/PM and Ce6/PM groups in lower EGFR expression HT-29 cells. For antitumor study, the tumor volumes in the C225-Ce6/PM-PDT group (percentage of tumor growth inhibition, TGI% = 84.8) were significantly smaller than those in the Ce6-PDT (TGI% = 38.4) and Ce6/PM-PDT groups (TGI% = 53.3) ( p < 0.05) at day 21 through reduced cell proliferation in A431 xenografted mice. These results indicated that active EGFR targeting of photosensitizer-loaded micelles provides a possible way to resolve the dose-limiting toxicity of conventional photosensitizers and represents a potential delivery system for PDT in a clinical setting.

Fundamental Understanding of the Interaction of Acid Gases with CeO 2 : From Surface Science to Practical Catalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tumuluri, Uma; Rother, Gernot; Wu, Zili

Acid gases including CO 2, SO 2, and NO x are ubiquitous in large-scale energy applications including heterogeneous catalysis. The adverse environmental and health effects of these acid gases have resulted in high interest in the research and development of technologies to remove or convert these acid gases. The main challenge for the development of these technologies is to develop catalysts that are highly efficient, stable, and cost-effective, and many catalysts have been reported in this regard. CeO 2 and CeO 2-based catalysts have gained prominence in the removal and conversion of CO 2, SO 2, and NO x becausemore » of their structural robustness and redox and acid–base properties. In this article, we provide a brief overview of the application of CeO 2 and CeO 2-based catalysts for the removal of CO 2, SO 2, and NO x gases with an emphasis on the fundamental understanding of the interactions of these acid gases with CeO 2. The studies summarized in this review range from surface science using single crystals and thin films with precise crystallographic planes to practical catalysis applications of nanocrystalline and polycrystalline CeO 2 materials with defects and dopants. After an introduction to the properties of CeO 2 surfaces, their catalytic properties for conversions of different acid gases are reviewed and discussed. Lastly, we find that the surface atomic structure, oxygen vacancies, and surface acid–base properties of CeO 2 play vital roles in the surface chemistry and structure evolution during the interactions of acid gases with CeO 2 and CeO 2-based catalysts.« less

Silica coating influences the corona and biokinetics of cerium oxide nanoparticles.

PubMed

Konduru, Nagarjun V; Jimenez, Renato J; Swami, Archana; Friend, Sherri; Castranova, Vincent; Demokritou, Philip; Brain, Joseph D; Molina, Ramon M

2015-10-12

The physicochemical properties of nanoparticles (NPs) influence their biological outcomes. We assessed the effects of an amorphous silica coating on the pharmacokinetics and pulmonary effects of CeO2 NPs following intratracheal (IT) instillation, gavage and intravenous injection in rats. Uncoated and silica-coated CeO2 NPs were generated by flame spray pyrolysis and later neutron-activated. These radioactive NPs were IT-instilled, gavaged, or intravenously (IV) injected in rats. Animals were analyzed over 28 days post-IT, 7 days post-gavage and 2 days post-injection. Our data indicate that silica coating caused more but transient lung inflammation compared to uncoated CeO2. The transient inflammation of silica-coated CeO2 was accompanied by its enhanced clearance. Then, from 7 to 28 days, clearance was similar although significantly more (141)Ce from silica-coated (35%) was cleared than from uncoated (19%) (141)CeO2 in 28 days. The protein coronas of the two NPs were significantly different when they were incubated with alveolar lining fluid. Despite more rapid clearance from the lungs, the extrapulmonary (141)Ce from silica-coated (141)CeO2 was still minimal (<1%) although lower than from uncoated (141)CeO2 NPs. Post-gavage, nearly 100% of both NPs were excreted in the feces consistent with very low gut absorption. Both IV-injected (141)CeO2 NP types were primarily retained in the liver and spleen. The silica coating significantly altered the plasma protein corona composition and enhanced retention of (141)Ce in other organs except the liver. We conclude that silica coating of nanoceria alters the biodistribution of cerium likely due to modifications in protein corona formation after IT and IV administration.

Fundamental Understanding of the Interaction of Acid Gases with CeO 2 : From Surface Science to Practical Catalysis

DOE PAGES

Tumuluri, Uma; Rother, Gernot; Wu, Zili

2016-03-21

Acid gases including CO 2, SO 2, and NO x are ubiquitous in large-scale energy applications including heterogeneous catalysis. The adverse environmental and health effects of these acid gases have resulted in high interest in the research and development of technologies to remove or convert these acid gases. The main challenge for the development of these technologies is to develop catalysts that are highly efficient, stable, and cost-effective, and many catalysts have been reported in this regard. CeO 2 and CeO 2-based catalysts have gained prominence in the removal and conversion of CO 2, SO 2, and NO x becausemore » of their structural robustness and redox and acid–base properties. In this article, we provide a brief overview of the application of CeO 2 and CeO 2-based catalysts for the removal of CO 2, SO 2, and NO x gases with an emphasis on the fundamental understanding of the interactions of these acid gases with CeO 2. The studies summarized in this review range from surface science using single crystals and thin films with precise crystallographic planes to practical catalysis applications of nanocrystalline and polycrystalline CeO 2 materials with defects and dopants. After an introduction to the properties of CeO 2 surfaces, their catalytic properties for conversions of different acid gases are reviewed and discussed. Lastly, we find that the surface atomic structure, oxygen vacancies, and surface acid–base properties of CeO 2 play vital roles in the surface chemistry and structure evolution during the interactions of acid gases with CeO 2 and CeO 2-based catalysts.« less

A comparative study of the luminescence properties of LYSO:Ce, LSO:Ce, GSO:Ce and BGO single crystal scintillators for use in medical X-ray imaging.

PubMed

Valais, I; Michail, C; David, S; Nomicos, C D; Panayiotakis, G S; Kandarakis, I

2008-06-01

The present study is a comparative investigation of the luminescence properties of (Lu,Y)(2)SiO(5):Ce (LYSO:Ce), Lu(2)SiO(5):Ce (LSO:Ce), Gd(2)SiO(5):Ce (GSO:Ce) and (Bi(4)Ge(3)O(12)) BGO single crystal scintillators under medical X-ray excitation. All scintillating crystals have dimensions of 10 x 10 x 10 mm(3) are non-hygroscopic exhibiting high radiation absorption efficiency in the energy range used in medical imaging applications. The comparative investigation was performed by determining the absolute luminescence efficiency (emitted light flux over incident X-ray exposure) in X-ray energies employed in general X-ray imaging (40-140 kV) and in mammographic X-ray imaging (22-49 kV). Additionally, light emission spectra of crystals at various X-ray energies were measured, in order to determine the spectral compatibility to optical photon detectors incorporated in medical imaging systems and the overall efficiency (effective efficiency) of a scintillator-optical detector combination. The light emission performance of LYSO:Ce and LSO:Ce scintillators studied was found very high for X-ray imaging.

Human Muscle Protein Synthetic Responses during Weight-Bearing and Non-Weight-Bearing Exercise: A Comparative Study of Exercise Modes and Recovery Nutrition.

PubMed

Pasiakos, Stefan M; McClung, Holly L; Margolis, Lee M; Murphy, Nancy E; Lin, Gregory G; Hydren, Jay R; Young, Andrew J

2015-01-01

Effects of conventional endurance (CE) exercise and essential amino acid (EAA) supplementation on protein turnover are well described. Protein turnover responses to weighted endurance exercise (i.e., load carriage, LC) and EAA may differ from CE, because the mechanical forces and contractile properties of LC and CE likely differ. This study examined muscle protein synthesis (MPS) and whole-body protein turnover in response to LC and CE, with and without EAA supplementation, using stable isotope amino acid tracer infusions. Forty adults (mean ± SD, 22 ± 4 y, 80 ± 10 kg, VO 2peak 4.0 ± 0.5 L ∙ min(-1)) were randomly assigned to perform 90 min, absolute intensity-matched (2.2 ± 0.1 VO2 L ∙ m(-1)) LC (performed on a treadmill wearing a vest equal to 30% of individual body mass, mean ± SD load carried 24 ± 3 kg) or CE (cycle ergometry performed at the same absolute VO2 as LC) exercise, during which EAA (10 g EAA, 3.6 g leucine) or control (CON, non-nutritive) drinks were consumed. Mixed-muscle and myofibrillar MPS were higher during exercise for LC than CE (mode main effect, P < 0.05), independent of dietary treatment. EAA enhanced mixed-muscle and sarcoplasmic MPS during exercise, regardless of mode (drink main effect, P < 0.05). Mixed-muscle and sarcoplasmic MPS were higher in recovery for LC than CE (mode main effect, P < 0.05). No other differences or interactions (mode x drink) were observed. However, EAA attenuated whole-body protein breakdown, increased amino acid oxidation, and enhanced net protein balance in recovery compared to CON, regardless of exercise mode (P < 0.05). These data show that, although whole-body protein turnover responses to absolute VO2-matched LC and CE are the same, LC elicited a greater muscle protein synthetic response than CE.

Microstructural characterisation of Al-Si cast alloys containing rare earth additions

NASA Astrophysics Data System (ADS)

Elgallad, E. M.; Ibrahim, M. F.; Doty, H. W.; Samuel, F. H.

2018-05-01

This paper presents a thorough study on the effect of rare earth elements, specifically La and Ce, on the microstructure characteristics of non-modified and Sr-modified A356 and A413 alloys. Several alloys were prepared by adding 1% La and 1% Ce either individually or in combination. Microstructural characterisation was carried out using optical microscopy, scanning electron microscopy and electron probe microanalysis as well as differential scanning calorimetry (DSC) analysis. The results showed that the individual and combined additions of La and Ce did not bring about any modification or even refinement in the eutectic Si structure. Moreover, these additions were found to negate the modification effect of Sr, particularly in the presence of La. The A356 and A413 alloys containing La and/or Ce displayed high phase volume fractions owing to the formation of Al-Si-La/Ce/(La,Ce) and Al-Ti-La/Ce intermetallic phases. DSC analysis revealed that the formation temperatures of these phases varied from 560 to 568 °C and 568 to 574 °C, respectively. This analysis also showed that the addition of La and Ce whether individually or in combination resulted in a depression in the eutectic temperature and a considerable increase in the solidification range, particularly for the A413 alloy.

How BenMAP-CE Estimates the Health and Economic Effects of Air Pollution

EPA Pesticide Factsheets

The BenMAP-CE tool estimates the number and economic value of health impacts resulting from changes in air quality - specifically, ground-level ozone and fine particles. Learn what data BenMAP-CE uses and how the estimates are calculated.

Attapulgite-CeO2/MoS2 ternary nanocomposite for photocatalytic oxidative desulfurization

NASA Astrophysics Data System (ADS)

Li, Xiazhang; Zhang, Zuosong; Yao, Chao; Lu, Xiaowang; Zhao, Xiaobing; Ni, Chaoying

2016-02-01

Novel attapulgite(ATP)-CeO2/MoS2 ternary nanocomposites were synthesized by microwave assisted assembly method. The structures of the nanocomposites were characterized by XRD, FT-IR, UV-vis, XPS and in situ TEM. The photocatalytic activities of ATP-CeO2/MoS2 composites were investigated by degradating dibenzothiophene (DBT) in gasoline under visible light irradiation. The effect of the mass ratio of CeO2 to MoS2 on photocatalytic activity was investigated. The results indicate that the three-dimensional network structure is firmly constructed by ATP skeleton, CeO2 particles and MoS2 nanosheet which effectively increase the surface area of the composites and promote the separation of electrons and holes by resulting electronic transmission channels of multi-channel in space. The degradation rate of DBT can reach 95% under 3 h irradiation when the mass ratio of CeO2/MoS2 is 4/10. A plausible mechanism for the photocatalytic oxidative desulfurization of this nanocomposite is put forward.

CdS nanoparticles/CeO2 nanorods composite with high-efficiency visible-light-driven photocatalytic activity

NASA Astrophysics Data System (ADS)

You, Daotong; Pan, Bao; Jiang, Fan; Zhou, Yangen; Su, Wenyue

2016-02-01

Different mole ratios of CdS nanoparticles (NPs)/CeO2 nanorods (NRs) composites with effective contacts were synthesized through a two-step hydrothermal method. The crystal phase, microstructure, optical absorption properties, electrochemical properties and photocatalytic H2 production activity of these composites were investigated. It was concluded that the photogenerated charge carriers in the CdS NPs/CeO2 NRs composite with a proper mole ratio (1:1) exhibited the longest lifetime and highest separation efficiency, which was responsible for the highest H2-production rate of 8.4 mmol h-1 g-1 under visible-light irradiation (λ > 420 nm). The superior photocatalytic H2 evolution properties are attributed to the transfer of visible-excited electrons of CdS NPs to CeO2 NRs, which can effectively extend the light absorption range of wide-band gap CeO2 NRs. This work provides feasible routes to develop visible-light responsive CeO2-based nanomaterial for efficient solar utilization.

The Effect of Cerium Oxide Nanoparticle Valence State on Reactive Oxygen Species and Toxicity.

PubMed

Dunnick, Katherine M; Pillai, Rajalekshmi; Pisane, Kelly L; Stefaniak, Aleksandr B; Sabolsky, Edward M; Leonard, Stephen S

2015-07-01

Cerium oxide (CeO2) nanoparticles, which are used in a variety of products including solar cells, gas sensors, and catalysts, are expected to increase in industrial use. This will subsequently lead to additional occupational exposures, making toxicology screenings crucial. Previous toxicology studies have presented conflicting results as to the extent of CeO2 toxicity, which is hypothesized to be due to the ability of Ce to exist in both a +3 and +4 valence state. Thus, to study whether valence state and oxygen vacancy concentration are important in CeO2 toxicity, CeO2 nanoparticles were doped with gadolinium to adjust the cation (Ce, Gd) and anion (O) defect states. The hypothesis that doping would increase toxicity and decrease antioxidant abilities as a result of increased oxygen vacancies and inhibition of +3 to +4 transition was tested. Differences in toxicity and reactivity based on valence state were determined in RLE-6TN rat alveolar epithelial and NR8383 rat alveolar macrophage cells using enhanced dark field microscopy, electron paramagnetic resonance (EPR), and annexin V/propidium iodide cell viability stain. Results from EPR indicated that as doping increased, antioxidant potential decreased. Alternatively, doping had no effect on toxicity at 24 h. The present results imply that as doping increases, thus subsequently increasing the Ce(3+)/Ce(4+) ratio, antioxidant potential decreases, suggesting that differences in reactivity of CeO2 are due to the ability of Ce to transition between the two valence states and the presence of increased oxygen vacancies, rather than dependent on a specific valence state.

Performance comparison between ceramic Ce:GAGG and single crystal Ce:GAGG with digital-SiPM

NASA Astrophysics Data System (ADS)

Park, C.; Kim, C.; Kim, J.; Lee, Y.; Na, Y.; Lee, K.; Yeom, J. Y.

2017-01-01

The Gd3Al2Ga3O12 (Ce:GAGG) is a new inorganic scintillator known for its attractive properties such as high light yield, stopping power and relatively fast decay time. In this study, we fabricated a ceramic Ce:GAGG scintillator as a cost-effective alternative to single crystal Ce:GAGG and, for the first time, investigated their performances when coupled to the digital silicon photomultiplier (dSiPM)—a new type of photosensor designed for applications in medical imaging, high energy and astrophysics. Compared to 3 × 3 × 2 mm3 sized single crystal Ce:GAGG, the translucent ceramic Ce:GAGG, which has a much lower transmittance than the single crystal, was determined to give an output signal amplitude that is approximately 61% of single crystal Ce:GAGG. The energy resolution of the 511 keV annihilation peak of a 22Na source was measured to be 9.9 ± 0.2% and 13.0 ± 0.3% for the single and ceramic scintillators respectively. On the other hand, the coincidence resolving time (CRT) of ceramic Ce:GAGG was 307 ± 23 ps, better than the 465 ± 37 ps acquired with single crystals—probably attributed to its slightly faster decay time and higher proportion of the fast decay component. The ceramic Ce:GAGG may be a promising cost-effective candidate for applications that do not require thick scintillators such as x-ray detectors and charged particle detectors, and those that require time-of-flight capabilities.

Towards understanding the electronic structure of Fe-doped CeO2 nanoparticles with X-ray spectroscopy.

PubMed

Wang, Wei-Cheng; Chen, Shih-Yun; Glans, Per-Anders; Guo, Jinghua; Chen, Ren-Jie; Fong, Kang-Wei; Chen, Chi-Liang; Gloter, Alexandre; Chang, Ching-Lin; Chan, Ting-Shan; Chen, Jin-Ming; Lee, Jyh-Fu; Dong, Chung-Li

2013-09-21

This study reports on the electronic structure of Fe-doped CeO2 nanoparticles (NPs), determined by coupled X-ray absorption spectroscopy and X-ray emission spectroscopy. A comparison of the local electronic structure around the Ce site with that around the Fe site indicates that the Fe substitutes for the Ce. The oxygen K-edge spectra that originated from the hybridization between cerium 4f and oxygen 2p states are sensitive to the oxidation state and depend strongly on the concentration of Fe doping. The Ce M(4,5)-edges and the Fe L(2,3)-edges reveal the variations of the charge states of Ce and Fe upon doping, respectively. The band gap is further obtained from the combined absorption-emission spectrum and decreased upon Fe doping, implying Fe doping introduces vacancies. The oxygen vacancies are induced by Fe doping and the spectrum reveals the charge transfer between Fe and Ce. Fe(3+) doping has two major effects on the formation of ferromagnetism in CeO2 nanoparticles. The first, at an Fe content of below 5%, is that the formation of Fe(3+)-Vo-Ce(3+) introduces oxygen deficiencies favoring ferromagnetism. The other, at an Fe content of over 5%, is the formation of Fe(3+)-Vo-Fe(3+), which favors antiferromagnetism, reducing the Ms. The defect structures Fe(3+)-Vo-Ce(3+) and Fe(3+)-Vo-Fe(3+) are crucial to the magnetism in these NPs and the change in Ms can be described as the effect of competitive interactions of magnetic polarons and paired ions.

Amygdala central nucleus interacts with dorsolateral striatum to regulate the acquisition of habits

PubMed Central

Lingawi, Nura W.; Balleine, Bernard W.

2012-01-01

The role of the amygdala central nucleus (CeN) in habit learning was assessed in two experiments. First we examined the effects of bilateral lesions of the anterior CeN on an overtraining-induced lever press habit evaluated using an outcome devaluation protocol. Overtraining generated habitual performance and rendered sham lesioned rats insensitive to outcome devaluation, an effect that was also found in rats given control lesions of the posterior CeN. In contrast, rats with lesions of the anterior CeN did not show normal habit acquisition and their performance remained goal-directed and sensitive to outcome devaluation. Nevertheless, lesions of either the posterior or the anterior CeN abolished the general excitatory influence of a Pavlovian CS on instrumental performance. Next we assessed the functional interaction between the CeN and dorsolateral striatum (DLS), a region previously implicated in the acquisition of habits, using asymmetrical lesions to disconnect these structures. Rats were given a unilateral lesion of anterior CeN and a unilateral lesion of the DLS, made either ipsilateral (control) or contralateral (disconnection) to the CeN lesion, and given overtraining followed by outcome devaluation. Although the ipsilateral lesioned rats were insensitive to devaluation, the contralateral CeN-DLS lesion impaired habit acquisition rendering performance sensitive to the devaluation treatment. These results are the first to implicate the CeN and its connection with a circuit involving DLS in habit learning. They imply that, in instrumental conditioning, regions of amygdala parse the instrumental outcome into the reward and reinforcement signals mediating goal-directed and habitual actions, respectively. PMID:22262905

L1-CAM-targeted antibody therapy and (177)Lu-radioimmunotherapy of disseminated ovarian cancer.

PubMed

Fischer, Eliane; Grünberg, Jürgen; Cohrs, Susan; Hohn, Alexander; Waldner-Knogler, Karin; Jeger, Simone; Zimmermann, Kurt; Novak-Hofer, Ilse; Schibli, Roger

2012-06-01

The L1-cell adhesion molecule (L1-CAM) is highly expressed in various cancer types including ovarian carcinoma but is absent from most normal tissue. A chimeric monoclonal antibody, chCE7, specifically binds to human L1-CAM and exhibits anti-proliferative effects on L1-CAM-expressing tumor cells. The goal of this study was to evaluate the efficacy of a novel (177)Lu-chCE7 radioimmunotherapeutic agent and to compare it to a treatment protocol with unlabeled, growth-inhibiting chCE7 in a mouse xenograft model of disseminated ovarian cancer. chCE7agl, an aglycosylated IgG1 variant with improved pharmacokinetics, was conjugated with 1,4,7,10-tetraazacyclododecane-N-N'-N'-N‴-tetraacetic acid (DOTA) and labeled with the low-energy β-emitter (177)Lu. Tumor growth and survival were assessed after a single i.v. dose of 8 MBq (60 μg) radioimmunoconjugate in nude mice bearing either subcutaneous or intraperitoneal SKOV3.ip1 human ovarian cancer tumors. Therapeutic efficacy was compared with three times weekly i.p. administration of 10 mg/kg unconjugated chCE7. In vivo analysis of (177)Lu-chCE7agl biodistribution demonstrated high and specific accumulation of radioactivity at the tumor site with maximal tumor uptake of up to 48.0 ± 8.1% ID/g at 168 h postinjection. A single treatment with (177)Lu-DOTA-chCE7agl caused significant retardation of tumor growth and prolonged median survival from 33 to 71 days, while administration of a nontargeted (177)Lu-immunoconjugate had no beneficial effect. Three times weekly i.p. application of unlabeled chCE7 10 mg/kg similarly increased survival from 44 to 72 days. We conclude that a single dose of (177)Lu-DOTA-chCE7agl is as effective as repeated administration of nonradioactive chCE7 for treatment of small intraperitoneal tumors expressing L1-CAM. Copyright © 2011 UICC.

Experimental study on Hg0 removal from flue gas over columnar MnOx-CeO2/activated coke

NASA Astrophysics Data System (ADS)

Xie, Yine; Li, Caiting; Zhao, Lingkui; Zhang, Jie; Zeng, Guangming; Zhang, Xunan; Zhang, Wei; Tao, Shasha

2015-04-01

Mn-Ce mixed oxides supported on commercial columnar activated coke (MnCe/AC) were employed to remove elemental mercury (Hg0) at low temperatures (100-250 °C) without the assistance of HCl in flue gas. The samples were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD). Effects of some factors, including Mn-Ce loading values, active component, reaction temperatures and flue gas components (O2, SO2, NO, H2O), on Hg0 removal efficiency were investigated. Results indicated that the optimal Mn-Ce loading value and reaction temperature were 6% and 190 °C, respectively. Considerable high Hg0 removal efficiency (>90%) can be obtained over MnCe6/AC under both N2/O2 atmosphere and simulated flue gas atmosphere at 190 °C. Besides, it was observed that O2 and NO exerted a promotional effect on Hg0 removal, H2O exhibited a suppressive effect, and SO2 hindered Hg0 removal seriously when in the absence of O2. Furthermore, the XPS spectra of Hg 4f and Hg-TPD results showed that the captured mercury were existed as Hg0 and HgO on the MnCe6/AC, and HgO was the major species, which illustrated that adsorption and catalytic oxidation process were included for Hg0 removal over MnCe6/AC, and catalytic oxidation played the critical role. What's more, both lattice oxygen and chemisorbed oxygen or OH groups on MnCe6/AC contributed to Hg0 oxidation. MnCe6/AC, which exhibited excellent performance on Hg0 removal in the absence of HCl, appeared to be promising in industrial application, especially for low-rank coal fired flue gas.

Effect of temperature on the low-linear energy transfer radiolysis of the ceric-cerous sulfate dosimeter: a Monte Carlo simulation study.

PubMed

Kohan, Leila Mirsaleh; Meesungnoen, Jintana; Sanguanmith, Sunuchakan; Meesat, Ridthee; Jay-Gerin, Jean-Paul

2014-05-01

The stochastic modeling of the (60)Co γ/fast-electron radiolysis of the ceric-cerous chemical dosimeter has been performed as a function of temperature from 25-350°C. The system used is a dilute solution of ceric sulfate and cerous sulfate in aqueous 0.4 M sulfuric acid. In this system, H(•) (or HO2(•) in the presence of dissolved oxygen) and H2O2 produced by the radiolytic decomposition of water both reduce Ce(4+) ions to Ce(3+) ions, while (•)OH radicals oxidize the Ce(3+) present in the solution back to Ce(4+). The net Ce(3+) yield is given by G(Ce(3+)) = g(H(•)) + 2 g(H2O2) - g((•)OH), where the primary (or "escape") yields of H(•), H2O2 and (•)OH are represented by lower case g's. At room temperature, G(Ce(3+)) has been established to be 2.44 ± 0.8 molecules/100 eV. In this work, we investigated the effect of temperature on the yield of Ce(3+) and on the underlying chemical reaction kinetics using Monte Carlo track chemistry simulations. The simulations showed that G(Ce(3+)) is time dependent, a result of the differences in the lifetimes of the reactions that make up the radiolysis mechanism. Calculated G(Ce(3+)) values were found to decrease almost linearly with increasing temperature up to about 250°C, and are in excellent agreement with available experimental data. In particular, our calculations confirmed previous estimated values by Katsumura et al. (Radiat Phys Chem 1988; 32:259-63) showing that G(Ce(3+)) at ∼250°C is about one third of its value at room temperature. Above ∼250°C, our model predicted that G(Ce(3+)) would drop markedly with temperature until, instead of Ce(4+) reduction, Ce(3+) oxidation is observed. This drop is shown to occur as a result of the reaction of hydrogen atoms with water in the homogeneous chemical stage.

The selective catalytic reduction of NO with NH3 over a novel Ce-Sn-Ti mixed oxides catalyst: Promotional effect of SnO2

NASA Astrophysics Data System (ADS)

Yu, Ming'e.; Li, Caiting; Zeng, Guangming; Zhou, Yang; Zhang, Xunan; Xie, Yin'e.

2015-07-01

A series of novel catalysts (CexSny) for the selective catalytic reduction of NO by NH3 were prepared by the inverse co-precipitation method. The aim of this novel design was to improve the NO removal efficiency of CeTi by the introduction of SnO2. It was found that the Ce-Sn-Ti catalyst was much more active than Ce-Ti and the best Ce:Sn molar ratio was 2:1. Ce2Sn1 possessed a satisfied NO removal efficiency at low temperature (160-280 °C), while over 90% NO removal efficiency maintained in the temperature range of 280-400 °C at the gas hourly space velocity (GHSV) of 50,000 h-1. Besides, Ce2Sn1 kept a stable NO removal efficiency within a wide range of GHSV and a long period of reacting time. Meanwhile, Ce2Sn1 exhibited remarkable resistance to both respectively and simultaneously H2O and SO2 poisoning due to the introduction of SnO2. The promotional effect of SnO2 was studied by N2 adsorption-desorption, X-ray diffraction (XRD), Raman spectra, X-ray photoelectron spectroscopy (XPS) and H2 temperature programmed reduction (H2-TPR) for detail information. The characterization results revealed that the excellent catalytic performance of Ce2Sn1 was associated with the higher specific surface area, larger pore volume and poorer crystallization. Besides, the introduction of SnO2 could result in not only greater conversion of Ce4+ to Ce3+ but also the increase amount of chemisorbed oxygen, which are beneficial to improve the SCR activity. More importantly, a novel peak appearing at lower temperatures through the new redox equilibrium of 2Ce4+ + Sn2+ ↔ 2Ce3+ + Sn4+ and higher total H2 consumption can be obtained by the addition of SnO2. Finally, the possible reaction mechanism of the selective catalytic reduction over Ce2Sn1 was also proposed.

Cerocene Revisited: The Electronic Structure of and Interconversion Between Ce2(C8H8)3 and Ce(C8H8)2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walter, Marc D.; Booth, Corwin H.; Lukens, Wayne W.

2009-02-02

New synthetic procedures for the preparation of Ce(cot)2, cerocene, from [Li(thf)4][Ce(cot)2], and Ce2(cot)3 in high yield and purity are reported. Heating solid Ce(cot)2 yields Ce2(cot)3 and COT while heating Ce2(cot)3 with an excess of COT in C6D6 to 65oC over four months yields Ce(cot)2. The solid state magnetic susceptibility of these three organocerium compounds shows that Ce(cot)2 behaves as a TIP (temperature independent paramagnet) over the temperature range of 5-300 K, while that of Ce2(cot)3 shows that the spin carriers are antiferromagnetically coupled below 10 K; above 10 K, the individual spins are uncorrelated, and [Ce(cot)2]- behaves as an isolatedmore » f1 paramagnet. The EPR at 1.5K for Ce2(cot)3 and [Ce(cot)2]- have ground state of MJ= +- 1/2. The LIII edge XANES of Ce(cot)2 (Booth, C.H.; Walter, M.D.; Daniel, M.; Lukens, W.W., Andersen, R.A., Phys. Rev. Lett. 2005, 95, 267202) and 2Ce2(cot)3 over 30-500 K are reported; the Ce(cot)2 XANES spectra show Ce(III) and Ce(IV) signatures up to a temperature of approximately 500 K, whereupon the Ce(IV) signature disappears, consistent with the thermal behavior observed in the melting experiment. The EXAFS of Ce(cot)2 and Ce2(cot)3 are reported at 30 K; the agreement between the molecular parameters for Ce(cot)2 derived from EXAFS and single crystal X-ray diffraction data are excellent. In the case of Ce2(cot)3 no X-ray diffraction data are known to exist, but the EXAFS are consistent with a"triple-decker" sandwich structure. A molecular rationalization is presented for the electronic structure of cerocene having a multiconfiguration ground state that is an admixture of the two configurations Ce(III, 4f1)(cot1.5-)2 and Ce(IV, 4f0)(cot2-)2; the multiconfigurational ground state has profound effects on the magnetic properties and on the nature of the chemical bond in cerocene and, perhaps, other molecules.« less

Physiological and Biochemical Changes Imposed by CeO2 Nanoparticles on Wheat: A Life Cycle Field Study.

PubMed

Du, Wenchao; Gardea-Torresdey, Jorge L; Ji, Rong; Yin, Ying; Zhu, Jianguo; Peralta-Videa, Jose R; Guo, Hongyan

2015-10-06

Interactions of nCeO2 with plants have been mostly evaluated at seedling stage and under controlled conditions. In this study, the effects of nCeO2 at 0 (control), 100 (low), and 400 (high) mg/kg were monitored for the entire life cycle (about 7 months) of wheat plants grown in a field lysimeter. Results showed that at high concentration nCeO2 decreased the chlorophyll content and increased catalase and superoxide dismutase activities, compared with control. Both concentrations changed root and leaf cell microstructures by agglomerating chromatin in nuclei, delaying flowering by 1 week, and reduced the size of starch grains in endosperm. Exposed to low concentration produced embryos with larger vacuoles, while exposure to high concentration reduced number of vacuoles, compared with control. There were no effects on the final biomass and yield, Ce concentration in shoots, as well as sugar and starch contents in grains, but grain protein increased by 24.8% and 32.6% at 100 and 400 mg/kg, respectively. Results suggest that more field life cycle studies are needed in order to better understand the effects of nCeO2 in crop plants.

In-situ Characterization of Cu/CeO 2 Nanocatalysts during CO 2 Hydrogenation: Morphological Effects of Nanostructured Ceria on the Catalytic Activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Lili; Yao, Siyu; Liu, Zongyuan

Here, a combination of time-resolved X-ray diffraction (TR-XRD), ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was used to carry out an in-situ characterization of Cu/CeO 2 nanocatalysts during the hydrogenation of CO 2. Morphological effects of the ceria supports on the catalytic performances were investigated by examining the behavior of copper/ceria-nanorods (NR) and nanospheres (NS). At atmospheric pressures, the hydrogenation of CO 2 on the copper-ceria catalysts produced mainly CO through the reverse-water gas shift reaction (RWGS) and a negligible amount of methanol. The Cu/CeO 2-NR catalyst displayed the higher activity, which demonstrates thatmore » the RWGS is a structure sensitive reaction. In-situ TR-XRD and AP-XPS characterization showed significant changes in the chemical state of the catalysts under reaction conditions with the copper being fully reduced and a partial Ce 4+ to Ce 3+ transformation occurring. A more effective CO 2 dissociative activation at high temperature and a preferential formation of active bidentate carbonate and formate intermediates over CeO 2(110) terminations are probably the main reasons for the better performance of the Cu/CeO 2-NR catalyst in the RWGS reaction.« less

Effects of added CeCl3 on resistance of fifth-instar larvae of silkworm to Bombyx mori nucleopolyhedrovirus infection.

PubMed

Li, Bing; Xie, Yi; Cheng, Zhe; Cheng, Jie; Hu, Rengping; Cui, Yaling; Gong, Xiaolan; Shen, Weide; Hong, Fashui

2012-06-01

One of the most important agents causing lethal disease in the silkworm is the Bombyx mori nucleopolyhedrovirus (BmNPV), while low-dose rare earths are demonstrated to increase immune capacity in animals. However, very little is known about the effects of added CeCl(3) on decreasing BmNPV infection of silkworm. The present study investigated the effects of added CeCl(3) to an artificial diet on resistance of fifth-instar larvae of silkworm to BmNPV infection. Our findings indicated that added CeCl(3) significantly decreased inhibition of growth and mortality of fifth-instar larvae caused by BmNPV infection. Furthermore, the added CeCl(3) obviously decreased lipid peroxidation level and accumulation of reactive oxygen species such as O(2)(-), H(2)O(2), (·)OH, and NO and increased activities of the antioxidant enzymes including superoxide dismutase, catalase, ascorbate peroxidase, glutathione peroxidase, ascorbate, and glutathione contents in the BmNPV-infected fifth-instar larvae. In addition, the added CeCl(3) could significantly promote acetylcholine esterase activity and attenuate the activity of inducible nitric oxide synthase in the BmNPV-infected fifth-instar larvae. These findings suggested that added CeCl(3) may relieve oxidative damage and neurotoxicity of silkworm caused by BmNPV infection via increasing antioxidant capacity and acetylcholine esterase activity.

In-situ Characterization of Cu/CeO 2 Nanocatalysts during CO 2 Hydrogenation: Morphological Effects of Nanostructured Ceria on the Catalytic Activity

DOE PAGES

Lin, Lili; Yao, Siyu; Liu, Zongyuan; ...

2018-05-28

Here, a combination of time-resolved X-ray diffraction (TR-XRD), ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was used to carry out an in-situ characterization of Cu/CeO 2 nanocatalysts during the hydrogenation of CO 2. Morphological effects of the ceria supports on the catalytic performances were investigated by examining the behavior of copper/ceria-nanorods (NR) and nanospheres (NS). At atmospheric pressures, the hydrogenation of CO 2 on the copper-ceria catalysts produced mainly CO through the reverse-water gas shift reaction (RWGS) and a negligible amount of methanol. The Cu/CeO 2-NR catalyst displayed the higher activity, which demonstrates thatmore » the RWGS is a structure sensitive reaction. In-situ TR-XRD and AP-XPS characterization showed significant changes in the chemical state of the catalysts under reaction conditions with the copper being fully reduced and a partial Ce 4+ to Ce 3+ transformation occurring. A more effective CO 2 dissociative activation at high temperature and a preferential formation of active bidentate carbonate and formate intermediates over CeO 2(110) terminations are probably the main reasons for the better performance of the Cu/CeO 2-NR catalyst in the RWGS reaction.« less

Enhancement of nitric oxide decomposition efficiency achieved with lanthanum-based perovskite-type catalyst.

PubMed

Pan, Kuan Lun; Chen, Mei Chung; Yu, Sheng Jen; Yan, Shaw Yi; Chang, Moo Been

2016-06-01

Direct decompositions of nitric oxide (NO) by La0.7Ce0.3SrNiO4, La0.4Ba0.4Ce0.2SrNiO4, and Pr0.4Ba0.4Ce0.2SrNiO4 are experimentally investigated, and the catalysts are tested with different operating parameters to evaluate their activities. Experimental results indicate that the physical and chemical properties of La0.7Ce0.3SrNiO4 are significantly improved by doping with Ba and partial substitution with Pr. NO decomposition efficiencies achieved with La0.4Ba0.4Ce0.2SrNiO4 and Pr0.4Ba0.4Ce0.2SrNiO4 are 32% and 68%, respectively, at 400 °C with He as carrier gas. As the temperature is increased to 600 °C, NO decomposition efficiencies achieved with La0.4Ba0.4Ce0.2SrNiO4 and Pr0.4Ba0.4Ce0.2SrNiO4, respectively, reach 100% with the inlet NO concentration of 1000 ppm while the space velocity is fixed at 8000 hr(-1). Effects of O2, H2O(g), and CO2 contents and space velocity on NO decomposition are also explored. The results indicate that NO decomposition efficiencies achieved with La0.4Ba0.4Ce0.2SrNiO4 and Pr0.4Ba0.4Ce0.2SrNiO4, respectively, are slightly reduced as space velocity is increased from 8000 to 20,000 hr(-1) at 500 °C. In addition, the activities of both catalysts (La0.4Ba0.4Ce0.2SrNiO4 and Pr0.4Ba0.4Ce0.2SrNiO4) for NO decomposition are slightly reduced in the presence of 5% O2, 5% CO2, or 5% H2O(g). For durability test, with the space velocity of 8000 hr(-1) and operating temperature of 600 °C, high N2 yield is maintained throughout the durability test of 60 hr, revealing the long-term stability of Pr0.4Ba0.4Ce0.2SrNiO4 for NO decomposition. Overall, Pr0.4Ba0.4Ce0.2SrNiO4 shows good catalytic activity for NO decomposition. Nitrous oxide (NO) not only causes adverse environmental effects such as acid rain, photochemical smog, and deterioration of visibility and water quality, but also harms human lungs and respiratory system. Pervoskite-type catalysts, including La0.7Ce0.3SrNiO4, La0.4Ba0.4Ce0.2SrNiO4, and Pr0.4Ba0.4Ce0.2SrNiO4, are applied for direct NO decomposition. The results show that NO decomposition can be enhanced as La0.7Ce0.3SrNiO4 is substituted with Ba and/or Pr. At 600 °C, NO decomposition efficiencies achieved with La0.4Ba0.4Ce0.2SrNiO4 and Pr0.4Ba0.4Ce0.2SrNiO4 reach 100%, demonstrating high activity and good potential for direct NO decomposition. Effects of O2, H2O(g), and CO2 contents on catalytic activities are also evaluated and discussed.

Effect of Nano CeO2 Addition on the Microstructure and Properties of a Cu-Al-Ni Shape Memory Alloy

NASA Astrophysics Data System (ADS)

Pandey, Abhishek; Jain, Ashish Kumar; Hussain, Shahadat; Sampath, V.; Dasgupta, Rupa

2016-08-01

This article deals with the effect of adding nano CeO2 to act as a grain pinner/refiner to a known Cu-Al-Ni shape memory alloy. Elements were taken in a predefined ratio to prepare 300 g alloy per batch and melted in an induction furnace. Casting was followed by homogenization at 1173 K (900 °C) and rolling to make sheets of 0.5-mm thickness. Further, samples were characterized for microstructure using optical and electron microscope, hardness, and different phase studies by X-ray and transformation temperatures by differential scanning calorimetry. X-ray peak broadenings and changes were investigated to estimate the crystallite size, lattice strain, and phase changes due to different processing steps. A nearly uniform distribution of CeO2 and better martensitic structure were observed with increasing CeO2. The addition of CeO2 also shows a visible effect on the transformation temperature and phase formation.

Ethanol produces corticotropin releasing factor receptor-dependent enhancement of spontaneous glutamatergic transmission in the mouse central amygdala

PubMed Central

Silberman, Yuval; Fetterly, Tracy L.; Awad, Elias K.; Milano, Elana J.; Usdin, Ted B.; Winder, Danny G.

2015-01-01

Background Ethanol modulation of Central Amygdala (CeA) neurocircuitry plays a key role in the development of alcoholism via activation of the corticotropin releasing factor (CRF) receptor system. Previous work has predominantly focused on ethanol/CRF interactions on the CeA GABA circuitry; however our lab recently showed that CRF enhances CeA glutamatergic transmission. Therefore, this study sought to determine if ethanol modulates CeA glutamate transmission via activation of CRF signaling. Methods The effects of ethanol on spontaneous excitatory postsynaptic currents (sEPSCs) and basal resting membrane potentials were examined via standard electrophysiology methods in adult male C57BL/6J mice. Local ablation of CeA CRF neurons (CRFCeAhDTR) was achieved by targeting the human diphtheria toxin receptor (hDTR) to CeA CRF neurons with an adeno-associated virus. Ablation was quantified post-hoc with confocal microscopy. Genetic targeting of the diphtheria toxin active subunit to CRF neurons (CRFDTA mice) ablated CRF neurons throughout the CNS, as assessed by qRT-PCR quantification of CRF mRNA. Results Acute bath application of ethanol significantly increased sEPSC frequency in a concentration dependent manner in CeA neurons, and this effect was blocked by pretreatment of co-applied CRF receptor 1 and CRF receptor 2 antagonists. In experiments utilizing a CRF-tomato reporter mouse, ethanol did not significantly alter the basal membrane potential of CeA CRF neurons. The ability of ethanol to enhance CeA sEPSC frequency was not altered in CRFCeAhDTR mice despite a ~78% reduction in CeA CRF cell counts. The ability of ethanol to enhance CeA sEPSC frequency was also not altered in the CRFDTA mice despite a three-fold reduction in CRF mRNA levels. Conclusion These findings demonstrate that ethanol enhances spontaneous glutamatergic transmission in the CeA via a CRF receptor dependent mechanism. Surprisingly, our data suggest that this action may not require endogenous CRF. PMID:26503065

2D and 3D registration methods for dual-energy contrast-enhanced digital breast tomosynthesis

NASA Astrophysics Data System (ADS)

Lau, Kristen C.; Roth, Susan; Maidment, Andrew D. A.

2014-03-01

Contrast-enhanced digital breast tomosynthesis (CE-DBT) uses an iodinated contrast agent to image the threedimensional breast vasculature. The University of Pennsylvania is conducting a CE-DBT clinical study in patients with known breast cancers. The breast is compressed continuously and imaged at four time points (1 pre-contrast; 3 postcontrast). A hybrid subtraction scheme is proposed. First, dual-energy (DE) images are obtained by a weighted logarithmic subtraction of the high-energy and low-energy image pairs. Then, post-contrast DE images are subtracted from the pre-contrast DE image. This hybrid temporal subtraction of DE images is performed to analyze iodine uptake, but suffers from motion artifacts. Employing image registration further helps to correct for motion, enhancing the evaluation of vascular kinetics. Registration using ANTS (Advanced Normalization Tools) is performed in an iterative manner. Mutual information optimization first corrects large-scale motions. Normalized cross-correlation optimization then iteratively corrects fine-scale misalignment. Two methods have been evaluated: a 2D method using a slice-by-slice approach, and a 3D method using a volumetric approach to account for out-of-plane breast motion. Our results demonstrate that iterative registration qualitatively improves with each iteration (five iterations total). Motion artifacts near the edge of the breast are corrected effectively and structures within the breast (e.g. blood vessels, surgical clip) are better visualized. Statistical and clinical evaluations of registration accuracy in the CE-DBT images are ongoing.

Combined effects of cerium and cooling rate on microstructure and mechanical properties of AZ91 magnesium alloy

NASA Astrophysics Data System (ADS)

Cai, Huisheng; Guo, Feng; Su, Juan

2018-01-01

The specimens of AZ91-xCe(x = 0, 0.3, 0.6, 0.9, 1.2, mass fraction wt%) with different thicknesses were prepared by die casting process, their as-cast microstructure and room temperature mechanical properties were investigated to analyze the change rule of microstructure and mechanical properties of AZ91 magnesium alloy under combined effects of cooling rate and cerium content. The results show that, the microstructure and mechanical properties of AZ91 magnesium alloy were twofold influenced by cooling rate and cerium content. With the increase of cooling rate and Ce content, the average as-cast grain size is evidently refined; the amount of β-Mg17Al12 decreases and distribution becomes discrete. While decreasing cooling rate or increasing Ce content, Al4Ce phase is more and the morphology tends to strip and needle from granular and short rod-like. The tensile strength and elongation of AZ91-xCe magnesium alloy are improved with increasing cooling rate. With the increase of Ce content, the tensile strength and elongation of AZ91-xCe magnesium alloy increased first and decreased afterwards, besides the action of Ce to improve tensile strength and elongation is more evident under faster cooling rate. Mechanical properties of samples are optimal in this work, when Ce content is 0.96% and cooling rate is 39.6 K s-1, tensile strength (259.7 MPa) and elongation (5.5%) are reached maximum, respectively.

Comparing Laser Peripheral Iridotomy to Cataract Extraction in Narrow Angle Eyes Using Anterior Segment Optical Coherence Tomography

PubMed Central

Melese, Ephrem; Peterson, Jeffrey R.; Feldman, Robert M.; Baker, Laura A.; Bell, Nicholas P.; Chuang, Alice Z.

2016-01-01

Purpose To evaluate the changes in anterior chamber angle (ACA) parameters in primary angle closure (PAC) spectrum eyes before and after cataract extraction (CE) and compare to the changes after laser peripheral iridotomy (LPI) using anterior segment optical coherence tomography (ASOCT). Methods Twenty-eight PAC spectrum eyes of 18 participants who underwent CE and 34 PAC spectrum eyes of 21 participants who underwent LPI were included. ASOCT images with 3-dimensional mode angle analysis scans were taken with the CASIA SS-1000 (Tomey Corp., Nagoya, Japan) before and after CE or LPI. Mixed-effect model analysis was used to 1) compare best-corrected visual acuity, intraocular pressure, and ACA parameters before and after CE; 2) identify and estimate the effects of potential contributing factors affecting changes in ACA parameters; and 3) compare CE and LPI treatment groups. Results The increase in average angle parameters (TISA750 and TICV750) was significantly greater after CE than LPI. TICV750 increased by 102% (2.114 [±1.203] μL) after LPI and by 174% (4.546 [± 1.582] μL) after CE (P < 0.001). Change of TICV750 in the CE group was significantly affected by age (P = 0.002), race (P = 0.006), and intraocular lens power (P = 0.037). Conclusions CE results in greater anatomic changes in the ACA than LPI in PAC spectrum eyes. ASOCT may be used to follow anatomic changes in the angle after intervention. PMID:27606482

Knowledge, attitude, and practices (KAP) and risk factors analysis related to cystic echinococcosis among residents in Tibetan communities, Xiahe County, Gansu Province, China.

PubMed

Li, Dan; Gao, Qi; Liu, Jian; Feng, Yu; Ning, Wenhua; Dong, Yanqing; Tao, Lixin; Li, Jingyi; Tian, Xiujun; Gu, Junchao; Xin, Deli

2015-07-01

Cystic echinococcosis (CE) is a global parasitic zoonosis caused by Echinococcus granulosus. The disease is highly endemic in western China, especially in Tibetan areas, because of poor economic development and hygiene conditions, limited community knowledge of CE, a large scale of dogs, and home slaughtering of livestock. Although many researchers have analyzed risk factors of CE transmission in Tibetan Plateau, there are rare reports of knowledge, attitude, and practice (KAP) of residents about CE in Tibetan communities. In our current study, community based cross-sectional study was conducted in three townships in Xiahe County, Gannan Tibetan Autonomous Prefectures of Gansu Province from May to September 2013. A total of 972 participants originating from Tibetan communities of 31 villages in the 3 townships were registered and data were collected using structured questionnaires. From the total of 972 study participants (457 males and 515 females), 65.9% heard of the disease CE. Most of them (96.1%) would like to accept CE inspection. About half of the peoples feed their dogs often and major of them do not play with the dogs. Risk factors included resident, knowing dog could be infected, knowing eating could be route of infection, oldest dog's age, usually feed your dog by self, feed dogs with internal organs. In general our findings showed that most of residents had positive attitude toward treatments of the disease, but their practice about disease prevention and control was low. Therefore, our study called for continued and strengthened education of changing the life style, especially the behaviors related to dogs. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Long term effects of cerium dioxide nanoparticles on the nitrogen removal, micro-environment and community dynamics of a sequencing batch biofilm reactor.

PubMed

Xu, Yi; Wang, Chao; Hou, Jun; Wang, Peifang; Miao, Lingzhan; You, Guoxiang; Lv, Bowen; Yang, Yangyang; Zhang, Fei

2017-12-01

The influences of cerium dioxide nanoparticles (CeO 2 NPs) on nitrogen removal in biofilm were investigated. Prolonged exposure (75d) to 0.1mg/L CeO 2 NPs caused no inhibitory effects on nitrogen removal, while continuous addition of 10mg/L CeO 2 NPs decreased the treatment efficiency to 53%. With the progressive concentration of CeO 2 NPs addition, the removal efficiency could nearly stabilize at 67% even with the continues spike of 10mg/L. The micro-profiles of dissolved oxygen, pH, and oxidation reduction potential suggested the developed protection mechanisms of microbes to progressive CeO 2 NPs exposure led to the less influence of microenvironment, denitrification bacteria and enzyme activity than those with continuous ones. Furthermore, high throughput sequencing illustrated the drastic shifted communities with gradual CeO 2 NPs spiking was responsible for the adaption and protective mechanisms. The present study demonstrated the acclimated microbial community was able to survive CeO 2 NPs addition more readily than those non-acclimated. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis of Ce doped ZnO nanoparticles coupled with graphene oxide as efficient photocatalyst for the degradation of dye under day light

NASA Astrophysics Data System (ADS)

Labhane, P. K.; Patle, L. B.; Huse, V. R.; Sonawane, G. H.

2018-05-01

Ce doped ZnO nanoparticles coupled with graphene oxide (Ce-ZnO/GO) photocatalyst was prepared by co-precipitation and wet impregnation method. The effect of Ce doping on ZnO and ZnO-GO composite has been evaluated by using XRD, Williamson-Hall Plot, FESEM and EDX data. Solar light photocatalytic activities of samples were evaluated spectrophotometrically by the degradation of methylene blue (MB). Ce doped ZnO coupled with GO shows excellent catalytic efficiency compared to other samples, degrading MB completely within 120 min under day light.

Color-tunable and white luminescence properties via energy transfer in single-phase KNaCa2(PO4)2:A (A = Ce3+, Eu2+, Tb3+, Mn2+, Sm3+) phosphors.

PubMed

Geng, Dongling; Shang, Mengmeng; Zhang, Yang; Lian, Hongzhou; Lin, Jun

2013-12-02

A series of single-phase phosphors based on KNaCa2(PO4)2 (KNCP):A (A = Ce(3+), Eu(2+), Tb(3+), Mn(2+), Sm(3+)) have been prepared via the Pechini-type sol-gel method. Photoluminescence (PL) and cathodoluminescence (CL) properties of Ce(3+)-, Eu(2+)-, Tb(3+)-, Mn(2+)-, and Sm(3+)-activated KNCP phosphors were investigated. For the A singly doped KNCP samples, they exhibit the characteristic emissions of the A activator. Na(+) ions exhibit the best charge compensation result among Li(+), Na(+), and K(+) ions for Ce(3+)-, Tb(3+)-, and Sm(3+)-doped KNCP samples. The energy transfers from Ce(3+) to Tb(3+) and Mn(2+) ions as well as Eu(2+) to Tb(3+) and Mn(2+) have been validated. The emission colors of KNCP:Ce(3+)/Eu(2+), Tb(3+)/Mn(2+), Na(+) samples can be adjusted by energy transfer process and changing the Tb(3+)/Mn(2+) concentration. More importantly, white light emission in KNCP:Eu(2+), Mn(2+) system has been obtained. The KNCP:Tb(3+), Na(+) sample shows tunable luminescence from blue to cyan and then to green with the change of Tb(3+) concentration due to the cross-relaxation from (5)D3 to (5)D4. A white emission can also be realized in the single-phase KNCP host by reasonably adjusting the doping concentrations of Tb(3+) and Sm(3+) (reddish-orange emission) under low-voltage electron beam excitation. Additionally, the temperature-dependent PL properties of as-prepared phosphors reveal that the KNCP host has good thermal stability. Therefore, the KNCP:A (A = Ce(3+), Eu(2+), Tb(3+), Mn(2+), Sm(3+)) phosphors could be regarded as good candidates for UV W-LEDs and FEDs.

Evaluation of human cystic echinococcosis before and after surgery and chemotherapy by demonstration of antibodies in serum.

PubMed

Tenguria, Rajesh Kumar; Naik, Mohd Irfan

2014-01-01

Human cystic echinococcosis (CE), caused by Echinococcus granulosus, is one of the most important and widespread parasitic zoonoses. As one of the problems that can be encountered after treating CE patients is the risk of postsurgical relapses or treatment failure, a long-term clinical and serological follow-up is required to evaluate the success and failure of therapy. Therefore, the aim of the present study was to identify the best diagnostic and prognostic ELISA markers in patients with CE. The cohort comprised 50 patients with symptomatic CE treated with antihelminthic drugs and surgery, who were followed up clinically and radiologically for a mean of 6 years (range 4-8 years). The results clearly indicate that the hydatid specific antibodies of IgE, IgG1 and IgG4 are the most important antibodies for the serological diagnosis of cystic echinococcosis during the active stage of the disease. None of the serum samples from healthy controls gave a non-specific reaction with IgE, IgG1 or IgG4, and a considerably reduced cross-reaction was observed with these antibodies. During post-operative follow-up, the IgM, IgE, IgG1, IgG2 and IgG4 antibody response provided the best correlate of disease activity. The detection of total IgG and IgG3 subclass antibody response for the assessment of post-treatment disease activity among CE patients was insensitive. All patients responded to treatment except 2 women (32 and 36 years old), in whom multiple cysts (12 and 7 cysts) were detected in the liver and lung two years after the first operation. Hence, it can be concluded that the CE-specific antibodies of IgE, IgG1 and IgG4 are the best immunological markers for diagnosis and prognosis of CE patients.

The association between histological, macroscopic and magnetic resonance imaging assessed synovitis in end-stage knee osteoarthritis: a cross-sectional study.

PubMed

Riis, R G C; Gudbergsen, H; Simonsen, O; Henriksen, M; Al-Mashkur, N; Eld, M; Petersen, K K; Kubassova, O; Bay Jensen, A C; Damm, J; Bliddal, H; Arendt-Nielsen, L; Boesen, M

2017-02-01

To investigate the association between magnetic resonance imaging (MRI), macroscopic and histological assessments of synovitis in end-stage knee osteoarthritis (KOA). Synovitis of end-stage osteoarthritic knees was assessed using non-contrast-enhanced (CE), contrast-enhanced magnetic resonance imaging (CE-MRI) and dynamic contrast-enhanced (DCE)-MRI prior to (TKR) and correlated with microscopic and macroscopic assessments of synovitis obtained intraoperatively. Multiple bivariate correlations were used with a pre-specified threshold of 0.70 for significance. Also, multiple regression analyses with different subsets of MRI-variables as explanatory variables and the histology score as outcome variable were performed with the intention to find MRI-variables that best explain the variance in histological synovitis (i.e., highest R 2 ). A stepped approach was taken starting with basic characteristics and non-CE MRI-variables (model 1), after which CE-MRI-variables were added (model 2) with the final model also including DCE-MRI-variables (model 3). 39 patients (56.4% women, mean age 68 years, Kellgren-Lawrence (KL) grade 4) had complete MRI and histological data. Only the DCE-MRI variable MExNvoxel (surrogate of the volume and degree of synovitis) and the macroscopic score showed correlations above the pre-specified threshold for acceptance with histological inflammation. The maximum R 2 -value obtained in Model 1 was R 2  = 0.39. In Model 2, where the CE-MRI-variables were added, the highest R 2  = 0.52. In Model 3, a four-variable model consisting of the gender, one CE-MRI and two DCE-MRI-variables yielded a R 2  = 0.71. DCE-MRI is correlated with histological synovitis in end-stage KOA and the combination of CE and DCE-MRI may be a useful, non-invasive tool in characterising synovitis in KOA. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Associations between ankle-brachial index and cognitive function: results from the Lifestyle Interventions and Independence for Elders trial

USDA-ARS?s Scientific Manuscript database

OBJECTIVE: The objective of this study was to evaluate cross-sectional and longitudinal associations between ankle-brachial index (ABI) and indicators of cognitive function. DESIGN: Randomized clinical trial (Lifestyle Interventions and Independence for Elders Trial). SETTING: Eight US academic ce...

Biotechnology and Genetic Engineering Reviews. Volume 10

DTIC Science & Technology

1992-12-01

Johnson of Rice University for supplying the graphic of the ce-subunit haem pocket. and Yvonne Le Tellier and Conrad Wheeler of the Blood Research...human hemoglobin cross-linked between the c, chains. J. Bol. Chem. 266- 2697-2700. VANDEGRIFF, K.D., LE TELLIER , Y.C., WINSIoW, R.M., Roili.t:s, R.J...cross-linked between the ax subunits at lysine 99. J. Biol. Chenm. 266, 17 049-17 059. VANDEGRIFF, K.D.. LE TELLIER , Y.C., hESS. J.R. ANt) StIRAGER, R.I

Synthesis of feather-like CeO2 microstructures and enzymatic electrochemical catalysis for trichloroacetic acid

NASA Astrophysics Data System (ADS)

Xiao, Xin; Zhang, Dong En; Zhang, Fan; Gong, Jun Yan; Zhang, Xiao Bo; Wang, Yi Hui; Ma, Juan Juan; Tong, Zhi Wei

Novel feather-like CeO2 microstructures were achieved by a thermal decomposition approach of Ce(OH)CO3 precursor. The Ce(OH)CO3 was obtained from a solvothermal method employing Ce(NO3)3.6H2O with C6H12N4 and C16H33(CH3)3NBr (CTAB) at 190∘C in a water-PEG-200 mixed solution. The feather-like CeO2 dendrite was obtained by thermal conversion of the feather-like Ce(OH)CO3 at 650∘C in air. A reasonable growth mechanism was proposed with the soft-template effect of PEG-200. The electrochemical behavior and enzyme activity of myoglobin (Mb) immobilized on CeO2-Nafion modified glassy carbon electrode (GCE) are demonstrated by cyclic voltammetric measurements. The results indicate that CeO2 can obviously promote the direct electron transfer between the Mb redox centers and the electrode. The Mb on CeO2-Nafion behaves as an elegant performance on the electrochemical reduction of trichloroacetic acid (TCA) from 0.32μM to 2.28μM. The detection limit is estimated to be 0.08μM.

Redox Reactivity of Cerium Oxide Nanoparticles Induces the Formation of Disulfide Bridges in Thiol-Containing Biomolecules.

PubMed

Rollin-Genetet, Françoise; Seidel, Caroline; Artells, Ester; Auffan, Mélanie; Thiéry, Alain; Vidaud, Claude

2015-12-21

The redox state of disulfide bonds is implicated in many redox control systems, such as the cysteine-cystine couple. Among proteins, ubiquitous cysteine-rich metallothioneins possess thiolate metal binding groups susceptible to metal exchange in detoxification processes. CeO2 NPs are commonly used in various industrial applications due to their redox properties. These redox properties that enable dual oxidation states (Ce(IV)/Ce(III)) to exist at their surface may act as oxidants for biomolecules. The interaction among metallothioneins, cysteine, and CeO2 NPs was investigated through various biophysical approaches to shed light on the potential effects of the Ce(4+)/Ce(3+) redox system on the thiol groups of these biomolecules. The possible reaction mechanisms include the formation of a disulfide bridge/Ce(III) complex resulting from the interaction between Ce(IV) and the thiol groups, leading to metal unloading from the MTs, depending on their metal content and cluster type. The formation of stable Ce(3+) disulfide complexes has been demonstrated via their fluorescence properties. This work provides the first evidence of thiol concentration-dependent catalytic oxidation mechanisms between pristine CeO2 NPs and thiol-containing biomolecules.

First principle study of electronic structures and optical properties of Ce-doped SiO2

NASA Astrophysics Data System (ADS)

Cong, Wei-Yan; Lu, Ying-Bo; Zhang, Peng; Guan, Cheng-Bo

2018-05-01

Electronic structures and optical properties of Silicon dioxide (SiO2) systems with and without cerium(Ce) dopant were calculated using the density functional theory. We find that after the Ce incorporation, a new localized impurity band appears between the valance band maximum (VBM) and the conduction band minimum (CBM) of SiO2 system, which is induced mainly by the Ce-4f orbitals. The localized impurity band constructs a bridge between the valence band and the conduction band, making the electronic transition much easier. The calculated optical properties show that in contrast from the pure SiO2 sample, absorption in the visible-light region is found in Ce-doped SiO2 system, which originates from the transition between the valence band and Ce-4f dominated impurity band, as well as the electronic transition from Ce-4f states to Ce-5d states. All calculated results indicate that Ce doping is an effective strategy to improve the optical performance of SiO2 sample, which is in agreement with the experimental results.

The relevance of the alliance for CME competencies for planning, organizing, and sustaining an interorganizational educational collaborative.

PubMed

Balmer, Jann T; Bellande, Bruce J; Addleton, Robert L; Havens, Carol S

2011-01-01

The heightened demand for accountability, access, and quality performance from health care professionals has resulted in linkages between continuing education (CE), performance improvement (PI), and outcomes. CE health professionals must also expand their skills and abilities to design, implement, and measure CE activities consistent with these new expectations. In addition to administrative and meeting-planning activities, new competencies associated with educational consultation and performance coaching are needed. This article utilizes the Alliance competencies as the framework for discussion of the competencies of CE professionals and applies it to the unique setting of a collaborative. The CS2day initiative serves as an example of the application of these competencies in this environment. The framework of the Alliance competencies can serve as a guide and a tool for self-assessment, work design, and professional development at individual, organization, and systems levels. Continual reassessment of the Alliance competencies for CE in the health professions will be critical to the continued effectiveness of CE that is linked to performance improvement and outcomes for the CE professional and the health care professionals we serve. A collaborative can provide one option for meeting these new expectations for professional development for CE professionals and the creation of effective educational initiatives. Copyright © 2011 The Alliance for Continuing Medical Education, the Society for Academic Continuing Medical Education, and the Council on CME, Association for Hospital Medical Education.

Green synthesis and antibacterial effects of aqueous colloidal solutions of silver nanoparticles using camomile terpenoids as a combined reducing and capping agent.

PubMed

Parlinska-Wojtan, Magdalena; Kus-Liskiewicz, Małgorzata; Depciuch, Joanna; Sadik, Omowunmi

2016-08-01

Green synthesis method using camomile extract was applied to synthesize silver nanoparticles to tune their antibacterial properties merging the synergistic effect of camomile and Ag. Scanning transmission electron microscopy revealed that camomile extract (CE) consisted of porous globular nanometer sized structures, which were a perfect support for Ag nanoparticles. The Ag nanoparticles synthesized with the camomile extract (AgNPs/CE) of 7 nm average sizes, were uniformly distributed on the CE support, contrary to the pure Ag nanoparticles synthesized with glucose (AgNPs/G), which were over 50 nm in diameter and strongly agglomerated. The energy dispersive X-ray spectroscopy chemical analysis showed that camomile terpenoids act as a capping and reducing agent being adsorbed on the surface of AgNPs/CE enabling their reduction from Ag(+) and preventing them from agglomeration. Fourier transform infrared and ultraviolet-visible spectroscopy measurements confirmed these findings, as the spectra of AgNPs/CE, compared to pure CE, did not contain the 1109 cm(-1) band, corresponding to -C-O groups of terpenoids and the peaks at 280 and 320 nm, respectively. Antibacterial tests using four bacteria strains showed that the AgNPs/CE performed five times better compared to CE AgNPs/G samples, reducing totally all the bacteria in 2 h.

Mg Doping Induced Effects on Structural, Optical, and Electrical Properties as Well as Cytotoxicity of CeO2 Nanostructures

NASA Astrophysics Data System (ADS)

Iqbal, Javed; Jan, Tariq; Awan, M. S.; Naqvi, Sajjad Haider; Badshah, Noor; ullah, Asmat; Abbas, Fazzal

2016-04-01

Here, Mg x Ce1- x O2 (where x = 0, 0.01, 0.02, 0.03, 0.04, and 0.05) nanostructures have been successfully synthesized by using a simple, easy, and cost-effective soft chemical method. X-ray diffraction (XRD) patterns substantiate the single-phase formation of a CeO2 cubic fluorite structure for all samples. Infrared spectroscopy results depict the presence of peaks only related to Ce-O bonding, which confirms the XRD results. It has been observed via ultraviolet (UV)-visible spectroscopy that Mg doping has tuned the optical band gap of CeO2 significantly. The electrical conductivity of CeO2 nanostructures has been found to increase with Mg doping, which is attributed to enhancement in carrier concentration due to the different valance states of dopant and host ions. Selective cytotoxic behavior of Mg x Ce1- x O2 nanostructures has been determined for neuroblastoma (SH-SY5Y) cancerous and HEK-293 healthy cells. Both doped and undoped CeO2 nanostructures have been found to be toxic for cancer cells and safe toward healthy cells. This selective toxic behavior of the synthesized nanostructures has been assigned to the different levels of reactive oxygen species (ROS) generation in different types of cells. This makes the synthesized nanostructures a potential option for cancer therapy in the near future.

Microwave synthesis of pure and doped cerium (IV) oxide (CeO2) nanoparticles for methylene blue degradation.

PubMed

El Rouby, W M A; Farghali, A A; Hamdedein, A

2016-11-01

Cerium (IV) oxide (CeO 2 ), samarium (Sm) and gadolinium (Gd) doped CeO 2 nanoparticles were prepared using microwave technique. The effect of microwave irradiation time, microwave power and pH of the starting solution on the structure and crystallite size were investigated. The prepared nanoparticles were characterized using X-ray diffraction, FT-Raman spectroscopy, and transmission electron microscope. The photocatalytic activity of the as-prepared CeO 2 , Sm and Gd doped CeO 2 toward degradation of methylene blue (MB) dye was investigated under UV light irradiation. The effect of pH, the amount of catalyst and the dye concentration on the degradation extent were studied. The photocatalytic activity of CeO 2 was kinetically enhanced by trivalent cation (Gd and Sm) doping. The results revealed that Gd doped CeO 2 nanoparticles exhibit the best catalytic degradation activity on MB under UV irradiation. For clarifying the environmental safety of the by products produced from the degradation process, the pathways of MB degradation were followed using liquid chromatography/mass spectroscopy (LC/MS). The total organic carbon content measurements confirmed the results obtained by LC/MS. Compared to the same nanoparticles prepared by another method, it was found that Gd doped CeO 2 prepared by hydrothermal process was able to mineralize MB dye completely under UV light irradiation.

Reduction in secondary dendrite arm spacing in cast eutectic Al-Si piston alloys by cerium addition

NASA Astrophysics Data System (ADS)

Ahmad, R.; Asmael, M. B. A.; Shahizan, N. R.; Gandouz, S.

2017-01-01

The effects of Ce on the secondary dendrite arm spacing (SDAS) and mechanical behavior of Al-Si-Cu-Mg alloys were investigated. The reduction of SDAS at different Ce concentrations was evaluated in a directional solidification experiment via computer-aided cooling curve thermal analysis (CA‒CCTA). The results showed that 0.1wt%-1.0wt% Ce addition resulted in a rapid solidification time, Δ t s, and low solidification temperature, Δ T S, whereas 0.1wt% Ce resulted in a fast solidification time, Δ t a-Al, of the α-Al phase. Furthermore, Ce addition refined the SDAS, which was reduced to approximately 36%. The mechanical properties of the alloys with and without Ce were investigated using tensile and hardness tests. The quality index ( Q) and ultimate tensile strength of (UTS) Al-Si-Cu-Mg alloys significantly improved with the addition of 0.1wt% Ce. Moreover, the base alloy hardness was improved with increasing Ce concentration.

Pulmonary Cerium Dioxide Nanoparticles Exposure Differentially Impairs Coronary and Mesenteric Arteriolar Reactivity

PubMed Central

Minarchick, Valerie C; Stapleton, Phoebe A; Porter, Dale W; Wolfarth, Michael G; Çiftyürek, Engin; Barger, Mark; Sabolsky, Edward M.; Nurkiewicz, Timothy R

2013-01-01

Cerium dioxide nanoparticles (CeO2 NPs) are an engineered nanomaterial that possesses unique catalytic, oxidative and reductive properties. Currently, CeO2 NPs are being used as a fuel catalyst but these properties are also utilized in the development of potential drug treatments for radiation and stroke protection. These uses of CeO2 NPs present a risk for human exposure; however, to date no studies have investigated the effects of CeO2 NPs on the microcirculation following pulmonary exposure. Previous studies in our laboratory with other nanomaterials have shown impairments in normal microvascular function after pulmonary exposures. Therefore, we predicted that CeO2 NP exposure would cause microvascular dysfunction that is dependent on the tissue bed and dose. Twenty-four hour post exposure to CeO2 NPs (0–400 μg), mesenteric and coronary arterioles were isolated and microvascular function was assessed. Our results provided evidence that pulmonary CeO2 NP exposure impairs endothelium-dependent and -independent arteriolar dilation in a dose-dependent manner. The CeO2 NP exposure dose which causes a 50% impairment in arteriolar function (EC50) was calculated and ranged from 15 – 100 μg depending on the chemical agonist and microvascular bed. Microvascular assessments with acetylcholine revealed a 33–75% reduction in function following exposure. Additionally, there was a greater sensitivity to CeO2 NP exposure in the mesenteric microvasculature due to the 40% decrease in the calculated EC50 compared to the coronary microvasculature EC50. CeO2 NP exposure increased mean arterial pressure in some groups. Taken together these observed microvascular changes may likely have detrimental effects on local blood flow regulation and contribute to cardiovascular dysfunction associated with particle exposure. PMID:23645470

Evaluation of in vitro cytotoxicity, biocompatibility, and changes in the expression of apoptosis regulatory proteins induced by cerium oxide nanocrystals

NASA Astrophysics Data System (ADS)

Khan, Shahanavaj; Ansari, Anees A.; Rolfo, Christian; Coelho, Andreia; Abdulla, Maha; Al-Khayal, Khayal; Ahmad, Rehan

2017-12-01

Cerium oxide nanocrystals (CeO2-NCs) exhibit superoxide dismutase and catalase mimetic activities. Based on these catalytic activities, CeO2-NCs have been suggested to have the potential to treat various diseases. The crystalline size of these materials is an important factor that influences the performance of CeO2-NCs. Previous reports have shown that several metal-based nanocrystals, including CeO2-NCs, can induce cytotoxicity in cancer cells. However, the underlying mechanisms have remained unclear. To characterize the anticancer activities of CeO2-NCs, several assays related to the mechanism of cytotoxicity and induction of apoptosis has been performed. Here, we have carried out a systematic study to characterize CeO2-NCs phase purity (X-ray diffraction), morphology (electron microscopy), and optical features (optical absorption, Raman scattering, and photoluminescence) to better establish their potential as anticancer drugs. Our study revealed anticancer effects of CeO2-NCs in HT29 and SW620 colorectal cancer cell lines with half-maximal inhibitory concentration (IC50) values of 2.26 and 121.18 μg ml-1, respectively. Reductions in cell viability indicated the cytotoxic potential of CeO2-NCs in HT29 cells based on inverted and florescence microscopy assessments. The mechanism of cytotoxicity confirmed by estimating possible changes in the expression levels of Bcl2, BclxL, Bax, PARP, cytochrome c, and β-actin (control) proteins in HT29 cells. Down-regulation of Bcl2 and BclxL and up-regulation of Bax, PARP, and cytochrome c proteins suggested the significant involvement of CeO2-NCs exposure in the induction of apoptosis. Furthermore, biocompatibility assay showed minimum effect of CeO2-NCs on human red blood cells.

Physiological and biochemical responses of sunflower (Helianthus annuus L.) exposed to nano-CeO2 and excess boron: Modulation of boron phytotoxicity.

PubMed

Tassi, E; Giorgetti, L; Morelli, E; Peralta-Videa, J R; Gardea-Torresdey, J L; Barbafieri, M

2017-01-01

Little is known about the interaction of nanoparticles (NPs) with soil constituents and their effects in plants. Boron (B), an essential micronutrient that reduces crop production at both deficiency and excess, has not been investigated with respect to its interaction with cerium oxide NPs (nano-CeO 2 ). Considering conflicting results on the nano-CeO 2 toxicity and protective role as antioxidant, their possible modulation on B toxicity in sunflower (Helianthus annuus L.) was investigated. Sunflower was cultivated for 30 days in garden pots containing original or B-spiked soil amended with nano-CeO 2 at 0-800 mg kg -1 . At harvest, Ce and B concentrations in tissues, biomass, and activities of stress enzymes in leaves were determined. Results showed that in the original soil, Ce accumulated mainly in roots, with little translocation to stems and leaves, while reduced root Ce was observed in plants from B-spiked soil. In the original soil, higher levels of nano-CeO 2 reduced plant B concentration. Although morphological effects were not visible, changes in biomass and oxidative stress response were observed. Sunflower leaves from B-spiked soil showed visible symptoms of B toxicity, such as necrosis and chlorosis in old leaves, as well as an increase of superoxide dismutase (SOD) activity. However, at high nano-CeO 2 level, SOD activity decreased reaching values similar to that of the control. This study has shown that nano-CeO 2 reduced both the B nutritional status of sunflower in original soil and the B phytotoxicity in B-spiked soil. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Nutritional quality assessment of tomato fruits after exposure to uncoated and citric acid coated cerium oxide nanoparticles, bulk cerium oxide, cerium acetate and citric acid.

PubMed

Barrios, Ana Cecilia; Medina-Velo, Illya A; Zuverza-Mena, Nubia; Dominguez, Osvaldo E; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

2017-01-01

Little is known about the effects of surface modification on the interaction of nanoparticles (NPs) with plants. Tomato (Solanum lycopersicum L.) plants were cultivated in potting soil amended with bare and citric acid coated nanoceria (nCeO 2, nCeO 2 +CA), cerium acetate (CeAc), bulk cerium oxide (bCeO 2 ) and citric acid (CA) at 0-500 mg kg -1 . Fruits were collected year-round until the harvesting time (210 days). Results showed that nCeO 2 +CA at 62.5, 250 and 500 mg kg -1 reduced dry weight by 54, 57, and 64% and total sugar by 84, 78, and 81%. At 62.5, 125, and 500 mg kg -1 nCeO 2 +CA decreased reducing sugar by 63, 75, and 52%, respectively and at 125 mg kg -1 reduced starch by 78%, compared to control. The bCeO 2 at 250 and 500 mg kg -1 , increased reducing sugar by 67 and 58%. In addition, when compared to controls, nCeO 2 at 500 mg kg -1 reduced B (28%), Fe (78%), Mn (33%), and Ca (59%). At 125 mg kg -1 decreased Al by 24%; while nCeO 2 +CA at 125 and 500 mg kg -1 increased B by 33%. On the other hand, bCeO 2 at 62.5 mg kg -1 increased Ca (267%), but at 250 mg kg -1 reduced Cu (52%), Mn (33%), and Mg (58%). Fruit macromolecules were mainly affected by nCeO 2 +CA, while nutritional elements by nCeO 2 ; however, all Ce treatments altered, in some way, the nutritional quality of tomato fruit. To our knowledge, this is the first study comparing effects of uncoated and coated nanoceria on tomato fruit quality. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

In vitro skin decontamination of the organophosphorus pesticide Paraoxon with nanometric cerium oxide CeO2.

PubMed

Salerno, Alicia; Devers, Thierry; Bolzinger, Marie-Alexandrine; Pelletier, Jocelyne; Josse, Denis; Briançon, Stéphanie

2017-04-01

Organophosphorus compounds (OP), which mainly penetrate via the percutaneous pathway, represent a threat for both military and civilians. Body surface decontamination is vital to prevent victims poisoning. The development of a cost-effective formulation, which could be efficient and easy to handle in case of mass contamination, is therefore crucial. Metal oxides nanoparticles, due their large surface areas and the large amount of highly reactive sites, present high reactivity towards OP. First, this study aimed at evaluating the reaction of CeO 2 nanoparticles, synthetized by microwave path and calcined at 500 or 600 °C, with Paraoxon (POX) in aqueous solution. Results showed that both nanoparticles degraded 60%-70% of POX. CeO 2 calcined at 500 °C, owing to its larger specific area, was the most effective. Moreover, the degradation was significantly increased under Ultra-Violet irradiation (initial degradation rate doubled). Then, skin decontamination was studied in vitro using the Franz cell method with pig-ear skin samples. CeO 2 powder and an aqueous suspension of CeO 2 (CeO 2 -W) were applied 1 h after POX exposure. The efficiency of decontamination, including removal and/or degradation of POX, was compared to Fuller's earth (FE) and RSDL lotion which are, currently, the most efficient systems for skin decontamination. CeO 2 -W and RSDL were the most efficient to remove POX from the skin surface and decrease skin absorption by 6.4 compared to the control not decontaminated. FE reduced significantly (twice) the absorbed fraction of POX, contrarily to CeO 2 powder. Considering only the degradation rate of POX, the products ranged in the order CeO 2  > RSDL > CeO 2 -W > FE (no degradation). This study showed that CeO 2 nanoparticles are a promising material for skin decontamination of OP if formulated as a dispersion able to remove POX like CeO 2 -W and to degrade it as CeO 2 powder. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The Effect of Chilling and Ce Addition on the Microstructure and Mechanical Properties of Al-23Si Alloy

NASA Astrophysics Data System (ADS)

Vijeesh, V.; Narayan Prabhu, K.

2017-01-01

The present work involves the study of the effect of varying concentration of Ce addition on microstructure and mechanical properties of Al-23%Si alloys. Melt-treated alloys were solidified in copper, brass, stainless steel molds to assess the effect of cooling rate. The effect on microstructure was assessed by measuring the fineness of primary silicon and eutectic silicon particle characteristics. The Ce melt treatment transformed the coarse and irregular primary silicon into refined polyhedral silicon crystals, and the effect was more significant at higher cooling rates. Although the melt treatment had refined the eutectic silicon at lower cooling rates, it did not show any considerable effect on the eutectic silicon at higher cooling rates. The mechanical properties of the alloy increased significantly with increase in cooling rates and cerium concentration. Analysis of the results and literature reveals that the refined primary silicon was formed as a result of an invariant reaction between Ce compounds and primary silicon at higher temperatures.

Use the results of measurements on KBR facility for testing of neutron data of main structural materials for fast reactors

NASA Astrophysics Data System (ADS)

Koscheev, Vladimir; Manturov, Gennady; Pronyaev, Vladimir; Rozhikhin, Evgeny; Semenov, Mikhail; Tsibulya, Anatoly

2017-09-01

Several k∞ experiments were performed on the KBR critical facility at the Institute of Physics and Power Engineering (IPPE), Obninsk, Russia during the 1970s and 80s for study of neutron absorption properties of Cr, Mn, Fe, Ni, Zr, and Mo. Calculations of these benchmarks with almost any modern evaluated nuclear data libraries demonstrate bad agreement with the experiment. Neutron capture cross sections of the odd isotopes of Cr, Mn, Fe, and Ni in the ROSFOND-2010 library have been reevaluated and another evaluation of the Zr nuclear data has been adopted. Use of the modified nuclear data for Cr, Mn, Fe, Ni, and Zr leads to significant improvement of the C/E ratio for the KBR assemblies. Also a significant improvement in agreement between calculated and evaluated values for benchmarks with Fe reflectors was observed. C/E results obtained with the modified ROSFOND library for complex benchmark models that are highly sensitive to the cross sections of structural materials are no worse than results obtained with other major evaluated data libraries. Possible improvement in results by decreasing the capture cross section for Zr and Mo at the energies above 1 keV is indicated.

What Makes Community Engagement Effective?: Lessons from the Eliminate Dengue Program in Queensland Australia

PubMed Central

2015-01-01

Background Worldwide, more than 40% of the population is at risk from dengue and recent estimates suggest that up to 390 million dengue infections are acquired every year. The Eliminate Dengue (ED) Program is investigating the use of Wolbachia-infected, transmission-compromised, mosquitoes to reduce dengue transmission. Previous introductions of genetically-modified strategies for dengue vector control have generated controversy internationally by inadequately engaging host communities. Community Engagement (CE) was a key component of the ED Program’s initial open release trials in Queensland Australia. Their approach to CE was perceived as effective by the ED team’s senior leadership, members of its CE team, and by its funders, but if and why this was the case was unclear. We conducted a qualitative case study of the ED Program’s approach to CE to identify and critically examine its components, and to explain whether and how these efforts contributed to the support received by stakeholders. Methodology/Principal Findings In-depth semi-structured interviews were conducted with 24 participants with a range of experiences and perspectives related to the ED Program’s CE activities. Our analytic approach combined techniques of grounded theory and qualitative description. The ED Program’s approach to CE reflected four foundational features: 1) enabling conditions; 2) leadership; 3) core commitments and guiding values; and 4) formative social science research. These foundations informed five key operational practices: 1) building the CE team; 2) integrating CE into management practices; 3) discerning the community of stakeholders; 4) establishing and maintaining a presence in the community; and 5) socializing the technology and research strategy. We also demonstrate how these practices contributed to stakeholders’ willingness to support the trials. Conclusions/Significance Our case study has identified, and explained the functional relationships among, the critical features of the ED Program’s approach to CE. It has also illuminated how these features were meaningful to stakeholders and contributed to garnering support within the host communities for the open-release trials. Our findings reveal how translating ethical intentions into effective action is more socially complex than is currently reflected in the CE literature. Because our case study delineates the critical features of the ED Program’s approach to CE, it can serve as a framework for other programs to follow when designing their own strategies. And because the findings outline a theory of change for CE, it can also serve as a starting point for developing an evaluation framework for CE. PMID:25875485

Effects of smolt release timing and size on the survival of hatchery-origin coho salmon in the Strait of Georgia

NASA Astrophysics Data System (ADS)

Irvine, J. R.; O'Neill, M.; Godbout, L.; Schnute, J.

2013-08-01

Altering release sizes and timings of coho salmon smolts from hatcheries in the Strait of Georgia will not reverse the precipitous survival declines of the past three decades. We modeled the effects on survival of ocean entry year, mean smolt size (weight), and release day. Ocean entry year was by far the most important. During 1979-2006, smolt to adult survivals declined similarly for hatchery and wild coho salmon, although wild salmon consistently survived at higher rates. Best models differed among hatcheries, implying location-specific differences in the optimal size and timing of release. At four of five hatcheries, heavier smolts survived significantly better than lighter smolts. At one hatchery, a significant interaction between ocean entry year and smolt weight reflected an increased positive effect of weight later in the time series. At two Vancouver Island hatcheries, early release groups appeared to survive better than later releases in early years, while later release groups survived best in recent years. We recommend: (1) hatchery managers release coho salmon smolts throughout the outmigration period of higher surviving wild coho salmon smolts and (2) an experimental approach using hatcheries to evaluate density-dependent effects on coho salmon growth and survival.

Emission properties and back-bombardment for CeB{sub 6} compared to LaB{sub 6}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bakr, Mahmoud, E-mail: m-a-bakr@iae.kyoto-u.ac.jp; Kawai, M.; Kii, T.

The emission properties of CeB{sub 6} compared to LaB{sub 6} thermionic cathodes have been measured using an electrostatic DC gun. Obtaining knowledge of the emission properties is the first step in understanding the back-bombardment effect that limits wide usage of thermionic radio-frequency electron guns. The effect of back-bombardment electrons on CeB{sub 6} compared to LaB{sub 6} was studied using a numerical simulation model. The results show that for 6 μs pulse duration with input radio-frequency power of 8 MW, CeB{sub 6} should experience 14% lower temperature increase and 21% lower current density rise compared to LaB{sub 6}. We conclude that CeB{submore » 6} has the potential to become the future replacement for LaB{sub 6} thermionic cathodes in radio-frequency electron guns.« less

Effects of annealing process on magnetic properties and structures of Nd-Pr-Ce-Fe-B melt-spun powders

NASA Astrophysics Data System (ADS)

Pei, Kun; Lin, Min; Yan, Aru; Zhang, Xing

2016-05-01

The effects of annealing process on magnetic properties and structures of Nd-Pr-Ce-Fe-B melt-spun powders have been investigated. The magnetic properties improve a lot when the annealing temperature is 590-650 °C and the annealing time exceeds 1 min. The magnetic properties is stable when the annealing time is 590-650 °C. The powders contains obvious grains when the annealing time is only 1 min, while the grains grow up obviously, leading to the decrease of Br and (BH)max, when the annealing time is more than 9 min. The Hcj changes little for different annealing time. The cooling rate also affects the magnetic properties of powders with different Ce-content. Faster cooling rate is favorable to improve magnetic properties with low Ce-content powders, while high Ce-content powders need slower cooling rate.

Mg,Ce co-doped Lu2Gd1(Ga,Al)5O12 by micro-pulling down method and their luminescence properties

NASA Astrophysics Data System (ADS)

Kamada, Kei; Yamaguchi, Hiroaki; Yoshino, Masao; Kurosawa, Shunsuke; Shoji, Yasuhiro; Yokota, Yuui; Ohashi, Yuji; Pejchal, Jan; Nikl, Martin; Yoshikawa, Akira

2018-04-01

The effects of Mg co-doping on the scintillation properties of Ce:Lu2Gd1(Ga,Al)5O12 (LGGAG) single crystals with different Ga/Al ratios were investigated. Mg co-doped and non co-doped Ce:LGGAG single crystals were grown by the micro-pulling down (µ-PD) method and then cut, polished and annealed for each measurement. Absorption spectra, radioluminescence (RL) spectra, pulse height spectra, and scintillation decay were measured to reveal the effect of Mg co-doping. Ce4+ charge transfer (CT) absorption band peaking at ∼260 nm was observed in Mg co-doped samples, which is in good agreement with previous reports for the Ce4+ CT absorption band in other garnet-based crystals. The scintillation decay time tended to be accelerated and the light yield tended to be decreased by Mg co-doping at higher Ga concentrations.

Nonlinear autoregressive neural networks with external inputs for forecasting of typhoon inundation level.

PubMed

Ouyang, Huei-Tau

2017-08-01

Accurate inundation level forecasting during typhoon invasion is crucial for organizing response actions such as the evacuation of people from areas that could potentially flood. This paper explores the ability of nonlinear autoregressive neural networks with exogenous inputs (NARX) to predict inundation levels induced by typhoons. Two types of NARX architecture were employed: series-parallel (NARX-S) and parallel (NARX-P). Based on cross-correlation analysis of rainfall and water-level data from historical typhoon records, 10 NARX models (five of each architecture type) were constructed. The forecasting ability of each model was assessed by considering coefficient of efficiency (CE), relative time shift error (RTS), and peak water-level error (PE). The results revealed that high CE performance could be achieved by employing more model input variables. Comparisons of the two types of model demonstrated that the NARX-S models outperformed the NARX-P models in terms of CE and RTS, whereas both performed exceptionally in terms of PE and without significant difference. The NARX-S and NARX-P models with the highest overall performance were identified and their predictions were compared with those of traditional ARX-based models. The NARX-S model outperformed the ARX-based models in all three indexes, whereas the NARX-P model exhibited comparable CE performance and superior RTS and PE performance.

Magnetic field-induced Fermi surface reconstruction and quantum criticality in CeRhIn 5

DOE PAGES

Jiao, Lin; Weng, Z. F.; Smidman, Michael; ...

2017-02-06

Here, we present detailed results of the field evolution of the de Haas–van Alphen (dHvA) effect in CeRhIn 5. A magnetic field-induced reconstruction of the Fermi surface is clearly shown to occur inside the antiferromagnetic state, in an applied field of around B* ≃ 30 T, which is evidenced by the appearance of several new dHvA branches. The angular dependence of the dHvA frequencies reveals that the Fermi surfaces of CeRhIn 5 at B > B* and CeCoIn5 are similar. The results suggest that the Ce-4f electrons in become itinerant at B > B* due to the Kondo effect, priormore » to the field-induced quantum critical point (QCP) at Bc0 ≃ 50 T. The electronic states at the field-induced QCP are therefore different from that of the pressure-induced QCP where a dramatic Fermi surface reconstruction occurs exactly at the critical pressure, indicating that multiple types of QCP may exist in CeRhIn 5.« less

D-cycloserine combined with cue exposure therapy fails to attenuate subjective and physiological craving in cocaine dependence.

PubMed

Santa Ana, Elizabeth J; Prisciandaro, James J; Saladin, Michael E; McRae-Clark, Aimee L; Shaftman, Stephanie R; Nietert, Paul J; Brady, Kathleen T

2015-04-01

Based on preclinical studies showing that the partial N-methyl-D-aspartate (NMDA) agonist D-cycloserine (DCS) facilitates extinction of cocaine self-administration and cocaine-induced conditioned place preference, we evaluated whether 50 mg of DCS would reduce craving to cocaine cues when combined with cue exposure (CE) in cocaine dependent humans. In this double-blind placebo-controlled pilot study, 47 cocaine dependent participants were randomized to DCS or placebo (PBO), plus CE. Participants received DCS or PBO 30 minutes prior to two CE sessions, conducted one day apart. Craving and heart rate was assessed prior to CE sessions, during CE trials, and after CE trials. These measures were assessed again at a 1-week follow-up (session 3) after the second CE session. DCS failed to significantly attenuate cocaine cue reactivity based on subjective craving and physiological reactivity (heart rate) compared to PBO. The CE protocol, consisting of repeated exposure to drug cues combined with skills training, resulted in extinction to cocaine cues as suggested by decreased craving within and between sessions in both treatment conditions. All participants exhibited elevated heart rate with repeated exposures, demonstrating a potentiation in heart rate between sessions. 50 mg of DCS may not be effective for extinguishing reactivity to drug cues for individuals with cocaine dependence. Future studies examining the effect of DCS on facilitating extinction to drug cues should examine variations in cue exposure length, number of CE presentations, and timing of DCS dose administration prior to cue exposures, which may differentially impact drug cue reactivity. © American Academy of Addiction Psychiatry.

Constant envelope OFDM scheme for 6PolSK-QPSK

NASA Astrophysics Data System (ADS)

Li, Yupeng; Ding, Ding

2018-03-01

A constant envelope OFDM scheme with phase modulator (PM-CE-OFDM) for 6PolSK-QPSK modulation was demonstrated. Performance under large fiber launch power is measured to check its advantages in counteracting fiber nonlinear impairments. In our simulation, PM-CE-OFDM, RF-assisted constant envelope OFDM (RF-CE-OFDM) and conventional OFDM (Con-OFDM) are transmitted through 80 km standard single mode fiber (SSMF) single channel and WDM system. Simulation results confirm that PM-CE-OFDM has best performance in resisting fiber nonlinearity. In addition, benefiting from the simple system structure, the complexity and cost of PM-CE-OFDM system could be reduced effectively.

Ground truth seismic events and location capability at Degelen mountain, Kazakhstan

USGS Publications Warehouse

Trabant, C.; Thurber, C.; Leith, W.

2002-01-01

We utilized nuclear explosions from the Degelen Mountain sub-region of the Semipalatinsk Test Site (STS), Kazakhstan, to assess seismic location capability directly. Excellent ground truth information for these events was either known or was estimated from maps of the Degelen Mountain adit complex. Origin times were refined for events for which absolute origin time information was unknown using catalog arrival times, our ground truth location estimates, and a time baseline provided by fixing known origin times during a joint hypocenter determination (JHD). Precise arrival time picks were determined using a waveform cross-correlation process applied to the available digital data. These data were used in a JHD analysis. We found that very accurate locations were possible when high precision, waveform cross-correlation arrival times were combined with JHD. Relocation with our full digital data set resulted in a mean mislocation of 2 km and a mean 95% confidence ellipse (CE) area of 6.6 km2 (90% CE: 5.1 km2), however, only 5 of the 18 computed error ellipses actually covered the associated ground truth location estimate. To test a more realistic nuclear test monitoring scenario, we applied our JHD analysis to a set of seven events (one fixed) using data only from seismic stations within 40?? epicentral distance. Relocation with these data resulted in a mean mislocation of 7.4 km, with four of the 95% error ellipses covering less than 570 km2 (90% CE: 438 km2), and the other two covering 1730 and 8869 km2 (90% CE: 1331 and 6822 km2). Location uncertainties calculated using JHD often underestimated the true error, but a circular region with a radius equal to the mislocation covered less than 1000 km2 for all events having more than three observations. ?? 2002 Elsevier Science B.V. All rights reserved.

Evaluation of the effect of valence state on cerium oxide nanoparticle toxicity following intratracheal instillation in rats

PubMed Central

Dunnick, Katherine M.; Morris, Anna M.; Badding, Melissa A.; Barger, Mark; Stefaniak, Aleksandr B.; Sabolsky, Edward M.; Leonard, Stephen S.

2016-01-01

Cerium (Ce) is becoming a popular metal for use in electrochemical applications. When in the form of cerium oxide (CeO2), Ce can exist in both 3 + and 4 + valence states, acting as an ideal catalyst. Previous in vitro and in vivo evidence have demonstrated that CeO2 has either anti- or pro-oxidant properties, possibly due to the ability of the nanoparticles to transition between valence states. Therefore, we chose to chemically modify the nanoparticles to shift the valence state toward 3+. During the hydrothermal synthesis process, 10 mol% gadolinium (Gd) and 20 mol% Gd, were substituted into the lattice of the CeO2 nanoparticles forming a perfect solid solution with various A-site valence states. These two Gd-doped CeO2 nanoparticles were compared to pure CeO2 nanoparticles. Preliminary characteristics indicated that doping results in minimal size and zeta potential changes but alters valence state. Following characterization, male Sprague-Dawley rats were exposed to 0.5 or 1.0 mg/kg nanoparticles via a single intratracheal instillation. Animals were sacrificed and bronchoalveolar lavage fluid and various tissues were collected to determine the effect of valence state and oxygen vacancies on toxicity 1-, 7-, or 84-day post-exposure. Results indicate that damage, as measured by elevations in lactate dehydrogenase, occurred within 1-day post-exposure and was sustained 7-day post-exposure, but subsided to control levels 84-day post-exposure. Furthermore, no inflammatory signaling or lipid peroxidation occurred following exposure with any of the nanoparticles. Our results implicate that valence state has a minimal effect on CeO2 nanoparticle toxicity in vivo. PMID:26898289

Cognitive and Neuroplasticity Mechanisms by Which Congenital or Early Blindness May Confer a Protective Effect Against Schizophrenia

PubMed Central

Silverstein, Steven M.; Wang, Yushi; Keane, Brian P.

2013-01-01

Several authors have noted that there are no reported cases of people with schizophrenia who were born blind or who developed blindness shortly after birth, suggesting that congenital or early (C/E) blindness may serve as a protective factor against schizophrenia. By what mechanisms might this effect operate? Here, we hypothesize that C/E blindness offers protection by strengthening cognitive functions whose impairment characterizes schizophrenia, and by constraining cognitive processes that exhibit excessive flexibility in schizophrenia. After briefly summarizing evidence that schizophrenia is fundamentally a cognitive disorder, we review areas of perceptual and cognitive function that are both impaired in the illness and augmented in C/E blindness, as compared to healthy sighted individuals. We next discuss: (1) the role of neuroplasticity in driving these cognitive changes in C/E blindness; (2) evidence that C/E blindness does not confer protective effects against other mental disorders; and (3) evidence that other forms of C/E sensory loss (e.g., deafness) do not reduce the risk of schizophrenia. We conclude by discussing implications of these data for designing cognitive training interventions to reduce schizophrenia-related cognitive impairment, and perhaps to reduce the likelihood of the development of the disorder itself. PMID:23349646

Characterization and synergetic antibacterial properties of ZnO and CeO2 supported by halloysite

NASA Astrophysics Data System (ADS)

Shu, Zhan; Zhang, Yi; Ouyang, Jing; Yang, Huaming

2017-10-01

A novel antibacterial nanocomposite, CeO2-ZnO/HNTs was prepared by a homogeneous co-precipitation method in ethanol solution. ZnO and CeO2 nanoparticles with sizes of approximately 8 and 4 nm, respectively, were dispersively precipitated onto the surface of halloysite nanotubes (HNTs). HNTs served as a template for reducing the agglomeration of ZnO nanoparticles and improving the interface reactions between the nanocomposite and bacteria cells. CeO2 nanoparticles were introduced to suppress the recombination of electron-hole pairs, and narrow the energy gap of ZnO nanoparticles. The synergistic effects of ZnO, CeO2 nanoparticles and HNTs led to the superior antibacterial activity of the CeO2-ZnO/HNTs nanocomposite against gram-negative Escherichia coli.

Multigroup cross section library for GFR2400

NASA Astrophysics Data System (ADS)

Čerba, Štefan; Vrban, Branislav; Lüley, Jakub; Haščík, Ján; Nečas, Vladimír

2017-09-01

In this paper the development and optimization of the SBJ_E71 multigroup cross section library for GFR2400 applications is discussed. A cross section processing scheme, merging Monte Carlo and deterministic codes, was developed. Several fine and coarse group structures and two weighting flux options were analysed through 18 benchmark experiments selected from the handbook of ICSBEP and based on performed similarity assessments. The performance of the collapsed version of the SBJ_E71 library was compared with MCNP5 CE ENDF/B VII.1 and the Korean KAFAX-E70 library. The comparison was made based on integral parameters of calculations performed on full core homogenous models.

Ocimum basilicum L.: phenolic profile and antioxidant-related activity.

PubMed

Dorman, H J Damien; Hiltunen, Raimo

2010-01-01

Ocimum basilicum L. leaf material was extracted by maceration with (80:20:1 v/v/v) methanol: water: acetic acid to produce a crude extract (CE), which was further fractionated by liquid-liquid extraction to isolate light petroleum (PE), ethyl acetate (EtOAc), n-butanol (n-BuOH) and H2O-soluble sub-fractions. The total phenol and flavonoid contents of the resulting samples were estimated using colorimetric-based methods, and their iron(III) reductive and free radical scavenging activities were determined in a battery of in vitro assays. The CE and sub-fractions contained phenolic compounds and flavonoids. The samples, except for PE, gave a positive result for the presence of flavones and flavonols; however, flavanones only appeared to be present in the CE. In iron(III) reduction, CE and n-BuOH were the most potent followed by EtOAc and H2O (statistically indistinguishable, p > 0.05). However, in the ferric reducing antioxidant power assay, H2O was the most potent followed by CE and EtOAc (statistically indistinguishable, p > 0.05) and n-BuOH and PE. In 1,1-diphenyl-2-picrylhydrazyl scavenging, all the samples, except PE, were effective against this reactive nitrogen species, with CE, EtOAc and n-BuOH being the most potent (statistically indistinguishable, p > 0.05). In alkylperoxyl scavenging, all the samples, except for PE, were effective against this reactive oxygen species (ROS). In superoxide anion scavenging, all the samples were capable of scavenging this ROS with CE being the most effective, followed by n-BuOH and H2O (statistically indistinguishable, p > 0.05) and EtOAc and PE. Similarly, in hydroxyl scavenging, all the samples were capable of scavenging this ROS with CE and n-BuOH being the most effective (statistically indistinguishable, p > 0.05) followed by EtOAc and H2O (statistically indistinguishable, p > 0.05) and PE.

Rutin-Enriched Extract from Coriandrum sativum L. Ameliorates Ionizing Radiation-Induced Hematopoietic Injury

PubMed Central

Han, Xiaodan; Xue, Xiaolei; Zhao, Yu; Li, Yuan; Liu, Weili; Zhang, Junling; Fan, Saijun

2017-01-01

Hematopoietic injury is a major cause of mortality in radiation accidents and a primary side effect in patients undergoing radiotherapy. Ionizing radiation (IR)-induced myelosuppression is largely attributed to the injury of hematopoietic stem and progenitor cells (HSPCs). Coriander is a culinary herb with multiple pharmacological effects and has been widely used in traditional medicine. In this study, flavonoids were identified as the main component of coriander extract with rutin being the leading compound (rutin-enriched coriander extract; RE-CE). We evaluated the radioprotective effect of RE-CE against IR-induced HSPCs injury. Results showed that RE-CE treatment markedly improved survival, ameliorated organ injuries and myelosuppression, elevated HSPCs frequency, and promoted differentiation and proliferation of HSPCs in irradiated mice. The protective role of RE-CE in hematopoietic injury is probably attributed to its anti-apoptotic and anti-DNA damage effect in irradiated HSPCs. Moreover, these changes were associated with reduced reactive oxygen species (ROS) and enhanced antioxidant enzymatic activities in irradiated HSPCs. Collectively, these findings demonstrate that RE-CE is able to ameliorate IR-induced hematopoietic injury partly by reducing IR-induced oxidative stress. PMID:28468251

Synergistic enhancement in photocatalytic performance of Ce (IV) and Cr (III) co-substituted magnetite nanoparticles loaded on reduced graphene oxide sheets.

PubMed

Rad, Tannaz Sadeghi; Khataee, Alireza; Rahim Pouran, Shima

2018-05-24

Effective utilization of visible-light by a photocatalyst is of great significance in photocatalytic processes. Herein, magnetite structure was modified by co-incorporation of Ce 4+ and Cr 3+ cations, and deposition on reduced graphene oxide sheets. The as-prepared Fe 2.8 Cr 0.2 O 4 #rGO and Fe 2.5 Cr 0.2 Ce 0.3 O 4 #rGO nanocomposites were characterized by XRD, SEM, X-ray Dot mapping, EDX, BET, DRS, XPS, FT-IR and VSM techniques and assessed for their photocatalytic performance under visible light irradiation for treatment of methylene blue. The results confirmed the central role of the incorporated Cr and Ce in improving the photocatalytic performance of magnetite through enhanced light harvesting, and the role of Ce 3+ /Ce 4+ redox pair, and rGO sheets in extending the life span of photo-induced e - /h + . Moreover, the influence of enhancers and scavengers were evaluated and oxidation path and generated byproducts were estimated. The results established the Fe 2.5 Cr 0.2 Ce 0.3 O 4 #rGO nanocomposite as a visible-light-driven photocatalyst for effective degradation of recalcitrant compounds. Copyright © 2018 Elsevier Inc. All rights reserved.

The effect of zirconium doping of cerium dioxide nanoparticles on pulmonary and cardiovascular toxicity and biodistribution in mice after inhalation.

PubMed

Dekkers, Susan; Miller, Mark R; Schins, Roel P F; Römer, Isabella; Russ, Mike; Vandebriel, Rob J; Lynch, Iseult; Belinga-Desaunay, Marie-France; Valsami-Jones, Eugenia; Connell, Shea P; Smith, Ian P; Duffin, Rodger; Boere, John A F; Heusinkveld, Harm J; Albrecht, Catrin; de Jong, Wim H; Cassee, Flemming R

2017-08-01

Development and manufacture of nanomaterials is growing at an exponential rate, despite an incomplete understanding of how their physicochemical characteristics affect their potential toxicity. Redox activity has been suggested to be an important physicochemical property of nanomaterials to predict their biological activity. This study assessed the influence of redox activity by modification of cerium dioxide nanoparticles (CeO 2 NPs) via zirconium (Zr) doping on the biodistribution, pulmonary and cardiovascular effects in mice following inhalation. Healthy mice (C57BL/6 J), mice prone to cardiovascular disease (ApoE -/- , western-diet fed) and a mouse model of neurological disease (5 × FAD) were exposed via nose-only inhalation to CeO 2 NPs with varying amounts of Zr-doping (0%, 27% or 78% Zr), or clean air, over a four-week period (4 mg/m 3 for 3 h/day, 5 days/week). Effects were assessed four weeks post-exposure. In all three mouse models CeO 2 NP exposure had no major toxicological effects apart from some modest inflammatory histopathology in the lung, which was not related to the amount of Zr-doping. In ApoE -/- mice CeO 2 did not change the size of atherosclerotic plaques, but there was a trend towards increased inflammatory cell content in relation to the Zr content of the CeO 2 NPs. These findings show that subacute inhalation of CeO 2 NPs causes minimal pulmonary and cardiovascular effect four weeks post-exposure and that Zr-doping of CeO 2 NPs has limited effect on these responses. Further studies with nanomaterials with a higher inherent toxicity or a broader range of redox activities are needed to fully assess the influence of redox activity on the toxicity of nanomaterials.

Structural Properties and Sensing Performance of CeYxOy Sensing Films for Electrolyte-Insulator-Semiconductor pH Sensors.

PubMed

Pan, Tung-Ming; Wang, Chih-Wei; Chen, Ching-Yi

2017-06-07

In this study we developed CeY x O y sensing membranes displaying super-Nernstian pH-sensitivity for use in electrolyte-insulator-semiconductor (EIS) pH sensors. We examined the effect of thermal annealing on the structural properties and sensing characteristics of the CeY x O y sensing membranes deposited through reactive co-sputtering onto Si substrates. X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy revealed the structural, morphological, and chemical features, respectively, of the CeY x O y films after their annealing at 600-900 °C. Among the tested systems, the CeY x O y EIS device prepared with annealing at 800 °C exhibited the highest sensitivity (78.15 mV/pH), the lowest hysteresis voltage (1.4 mV), and the lowest drift rate (0.85 mV/h). Presumably, these annealing conditions optimized the stoichiometry of (CeY)O 2 in the film and its surface roughness while suppressing silicate formation at the CeY x O y -Si interface. We attribute the super-Nernstian pH-sensitivity to the incorporation of Y ions in the Ce framework, thereby decreasing the oxidation state Ce (Ce 4+  → Ce 3+ ) and resulting in less than one electron transferred per proton in the redox reaction.

Ce and La single- and double-substitutional defects in yttrium aluminum garnet: first-principles study.

PubMed

Muñoz-García, Ana Belén; Seijo, Luis

2011-02-10

The atomistic structure, energetics, and electronic structure of single-substitutional Ce and La defects and double-substitutional Ce-La defects in Ce,La-codoped yttrium aluminum garnet (YAG) Y(3)Al(5)O(12) have been studied by means of first-principles periodic boundary conditions density functional theory calculations. Single substitution of Y by Ce or by La produces atomistic expansions around the impurities, which are significantly smaller than the ionic radii mismatches and the overall lattice distortions are found to be confined within their second coordination spheres. In double-substitutional defects, the impurities tend to be as close as possible. La-codoping Ce:YAG provokes an anisotropic expansion around Ce defects. The Ce impurity introduces 4f occupied states in the 5.0 eV computed gap of YAG, peaking 0.25 eV above the top of the valence band, and empty 4f, 5d, and 6s states starting at 3.8 eV in the gap and spreading over the conduction band. La-codoping produces very small effects on the electronic structure of Ce:YAG, the most visible one being the decrease in covalent bonding with one of the oxygen atoms, which shifts 0.05 Å away from Ce and gets 0.04 Å closer to La in the most stable Ce-La double-substitutional defect.

Effect of CeO2 coprecipitation on the electrochemical performance of Li(Li,Ni,Mn,Co)O2-CeO2-C composite cathode materials

NASA Astrophysics Data System (ADS)

Kurilenko, K. A.; Shlyakhtin, O. A.; Petukhov, D. I.; Garshev, A. V.

2017-06-01

Composite electrode materials Li[Li0.13Ni0.2Mn0.47Co0.2]O2 (LNMC)-CeO2-С are obtained by the coprecipitation of Co, Ni, Mn and Ce hydroxides followed by the coating of LNMC-CeO2 composites with pyrolytic carbon. The introduction of 5% CeO2 promotes the reduction of LNMC grain size from 190-230 to 100-170 nm and the corresponding increase in the electrochemical capacity of LNMC-CeO2 composite. The pyrolytic coating consists of the network of 2-5 nm polymer-carbon particles at the surface of LNMC crystallites. The electrochemical impedance spectroscopy data, which was performed after the galvanostatic cycling, demonstrated considerably lower charge transfer resistance of the carbon-coated composites compared to the bare LNMC and the LNMC-CeO2 composites. The values of the discharge capacity of LNMC-CeO2-C composites are superior to the capacity of LMNC-CeO2 and LMNC-C composites at all discharge rates (C/10 - 5C). The increase of the upper boundary of potentials to 4.8 V after cycling at 5C (U - 2÷4.6 V) promotes the increase of low rate electrochemical capacity of LNMC-CeO2-C composite to 220 mAh g-1.

Synthesis of novel CeO2-BiVO4/FAC composites with enhanced visible-light photocatalytic properties.

PubMed

Zhang, Jin; Wang, Bing; Li, Chuang; Cui, Hao; Zhai, Jianping; Li, Qin

2014-09-01

To utilize visible light more effectively in photocatalytic reactions, a fly ash cenosphere (FAC)-supported CeO2-BiVO4 (CeO2-BiVO4/FAC) composite photocatalyst was prepared by modified metalorganic decomposition and impregnation methods. The physical and photophysical properties of the composite have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and UV-Visible diffuse reflectance spectra. The XRD patterns exhibited characteristic diffraction peaks of both BiVO4 and CeO2 crystalline phases. The XPS results showed that Ce was present as both Ce(4+) and Ce(3+) oxidation states in CeO2 and dispersed on the surface of BiVO4 to constitute a p-n heterojunction composite. The absorption threshold of the CeO2-BiVO4/FAC composite shifted to a longer wavelength in the UV-Vis absorption spectrum compared to the pure CeO2 and pure BiVO4. The composites exhibited enhanced photocatalytic activity for Methylene Blue (MB) degradation under visible light irradiation. It was found that the 7.5wt.% CeO2-BiVO4/FAC composite showed the highest photocatalytic activity for MB dye wastewater treatment. Copyright © 2014. Published by Elsevier B.V.

Divergent functions of the left and right central amygdala in visceral nociception

PubMed Central

Sadler, Katelyn E.; McQuaid, Neal A.; Cox, Abigail C.; Behun, Marissa N.; Trouten, Allison M.; Kolber, Benedict J.

2017-01-01

The left and right central amygdalae (CeA) are limbic regions involved in somatic and visceral pain processing. These 2 nuclei are asymmetrically involved in somatic pain modulation; pain-like responses on both sides of the body are preferentially driven by the right CeA, and in a reciprocal fashion, nociceptive somatic stimuli on both sides of the body predominantly alter molecular and physiological activities in the right CeA. Unknown, however, is whether this lateralization also exists in visceral pain processing and furthermore what function the left CeA has in modulating nociceptive information. Using urinary bladder distension (UBD) and excitatory optogenetics, a pronociceptive function of the right CeA was demonstrated in mice. Channelrhodopsin-2–mediated activation of the right CeA increased visceromotor responses (VMRs), while activation of the left CeA had no effect. Similarly, UBD-evoked VMRs increased after unilateral infusion of pituitary adenylate cyclase–activating polypeptide in the right CeA. To determine intrinsic left CeA involvement in bladder pain modulation, this region was optogenetically silenced during noxious UBD. Halorhodopsin (NpHR)-mediated inhibition of the left CeA increased VMRs, suggesting an ongoing antinociceptive function for this region. Finally, divergent left and right CeA functions were evaluated during abdominal mechanosensory testing. In naive animals, channelrhodopsin-2–mediated activation of the right CeA induced mechanical allodynia, and after cyclophosphamide-induced bladder sensitization, activation of the left CeA reversed referred bladder pain–like behaviors. Overall, these data provide evidence for functional brain lateralization in the absence of peripheral anatomical asymmetries. PMID:28225716

Divergent functions of the left and right central amygdala in visceral nociception.

PubMed

Sadler, Katelyn E; McQuaid, Neal A; Cox, Abigail C; Behun, Marissa N; Trouten, Allison M; Kolber, Benedict J

2017-04-01

The left and right central amygdalae (CeA) are limbic regions involved in somatic and visceral pain processing. These 2 nuclei are asymmetrically involved in somatic pain modulation; pain-like responses on both sides of the body are preferentially driven by the right CeA, and in a reciprocal fashion, nociceptive somatic stimuli on both sides of the body predominantly alter molecular and physiological activities in the right CeA. Unknown, however, is whether this lateralization also exists in visceral pain processing and furthermore what function the left CeA has in modulating nociceptive information. Using urinary bladder distension (UBD) and excitatory optogenetics, a pronociceptive function of the right CeA was demonstrated in mice. Channelrhodopsin-2-mediated activation of the right CeA increased visceromotor responses (VMRs), while activation of the left CeA had no effect. Similarly, UBD-evoked VMRs increased after unilateral infusion of pituitary adenylate cyclase-activating polypeptide in the right CeA. To determine intrinsic left CeA involvement in bladder pain modulation, this region was optogenetically silenced during noxious UBD. Halorhodopsin (NpHR)-mediated inhibition of the left CeA increased VMRs, suggesting an ongoing antinociceptive function for this region. Finally, divergent left and right CeA functions were evaluated during abdominal mechanosensory testing. In naive animals, channelrhodopsin-2-mediated activation of the right CeA induced mechanical allodynia, and after cyclophosphamide-induced bladder sensitization, activation of the left CeA reversed referred bladder pain-like behaviors. Overall, these data provide evidence for functional brain lateralization in the absence of peripheral anatomical asymmetries.

Tetravalent Ce in the Nitrate-Decorated Hexanuclear Cluster [Ce 6 (μ 3 -O) 4 (μ 3 -OH) 4 ] 12+ : A Structural End Point for Ceria Nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Estes, Shanna L.; Antonio, Mark R.; Soderholm, L.

2016-03-17

We describe the synthesis and characterization of three glycine-stabilized hexanuclear Cely cluster compounds, each containing the [Ce-6(mu(3)-O)(4)(mu(3)-OH)(4)](12+) core structure. Crystallized from aqueous nitrate solutions with pH < 0, the core cluster structures exhibit variable decoration by nitrate, glycine, and water ligands depending on solution conditions, where increased nitrate and glycine decoration of the cluster core was observed for crystals synthesized at high Ce and nitrate concentrations. No other crystalline products were observed using this synthetic route. In addition to confirming the tetravalent oxidation state of cerium in one of the reported clusters, cyclic voltammetry also indicates that Ce-IV is reducedmore » at similar to+0.60 V vs Ag/AgCl (3 M NaCl), which is significantly less than the standard electrode potential. This large decrease in the Ce-IV/Ce-III reduction potential suggests that Ce-IV is significantly stabilized relative to Ce-III within the examined cluster. These compounds are discussed in terms of their importance as small, end member, ceric oxide nanoparticles. Single-crystal structural solutions, together with voltammetry and electrolysis data, permit the decoupling of Ce-III defects and substoichiometry. In addition, Ce-Ce distances can be used to determine an "effective" CeO2-x lattice constant, providing a simple method for comparing literature descriptions. The results are discussed in terms of their potential implications for the mechanisms by which nanoparticle ceria serve as catalysts and oxygen-storage materials.« less

Health Effects Associated with Inhalation Exposure to Diesel Emission Generated with and without CeO2 Nano Fuel Additive

EPA Science Inventory

Diesel exhaust (DE) exposure induces adverse cardiopulmonary effects. Addition of nano cerium (Ce) oxide additive to diesel fuel (DECe) increases fuel burning efficiency resulting in altered emission characteristics and potentially altered health effects. We hypothesized that inh...

Rapid enrichment of rare-earth metals by carboxymethyl cellulose-based open-cellular hydrogel adsorbent from HIPEs template.

PubMed

Zhu, Yongfeng; Wang, Wenbo; Zheng, Yian; Wang, Feng; Wang, Aiqin

2016-04-20

A series of monolithic open-cellular hydrogel adsorbents based on carboxymethylcellulose (CMC) were prepared through high internal phase emulsions (HIPEs) and used to enrich the rare-earth metals La(3+) and Ce(3+). The changes of pore structure, and the effects of pH, contact time, initial concentration on the adsorption performance were systematically studied. The results show that the as-prepared monolithic hydrogel adsorbents possess good open-cellular framework structure and have fast adsorption kinetics and high adsorption capacity for La(3+) and Ce(3+). The involved adsorption system can reach equilibrium within 30min and the maximal adsorption capacity is determined to be 384.62mg/g for La(3+) and 333.33mg/g for Ce(3+). Moreover, these porous hydrogel adsorbents show an excellent adsorptive reusability for La(3+) and Ce(3+) through five adsorption-desorption cycles. Such a pore hierarchy structure makes this monolithic open-cellular hydrogel adsorbent be an effective adsorbent for effective enrichment of La(3+) and Ce(3+) from aqueous solution. Copyright © 2015 Elsevier Ltd. All rights reserved.

Plasma-assisted adsorption of elemental mercury on CeO2/TiO2 at low temperatures

NASA Astrophysics Data System (ADS)

Liu, Lu; Zheng, Chenghang; Gao, Xiang

2017-11-01

Mercury is a kind of pollutants contained in flue gas which is hazardous for human beings. In this work, CeO2 was packed in the discharge zone of a plasma reactor to adsorb elemental mercury at low temperatures. Plasma-catalyst reactor can remove Hg0 efficiently with CeO2/TiO2 catalysts packed in the discharge zone. The Hg0 concentration continued to decrease gradually when the plasma was turned on, but not sank rapidly. This tendency was different with other catalysts. The treatment of plasma to CeO2/TiO2 catalysts has a promotion effect on the adsorption of Hg0. Plasma has the effect of changing the surface properties of the catalysts and the changes would restitute if the condition changed. The long-running test demonstrated that this method is an effective way to remove Hg0. The removal efficiency remained at above 99% throughout 12 hours when plasma had been turned on (15kV, 0.5 g packed CeO2/TiO2).

Analgesic Effects of Duloxetine on Formalin-Induced Hyperalgesia and Its Underlying Mechanisms in the CeA

PubMed Central

Zhang, Lie; Yin, Jun-Bin; Hu, Wei; Zhao, Wen-Jun; Fan, Qing-Rong; Qiu, Zhi-Chun; He, Ming-Jie; Ding, Tan; Sun, Yan; Kaye, Alan D.; Wang, En-Ren

2018-01-01

In rodents, the amygdala has been proposed to serve as a key center for the nociceptive perception. Previous studies have shown that extracellular signal-regulated kinase (ERK) signaling cascade in the central nucleus of amygdala (CeA) played a functional role in inflammation-induced peripheral hypersensitivity. Duloxetine (DUL), a serotonin and noradrenaline reuptake inhibitor, produced analgesia on formalin-induced spontaneous pain behaviors. However, it is still unclear whether single DUL pretreatment influences formalin-induced hypersensitivity and what is the underlying mechanism. In the current study, we revealed that systemic pretreatment with DUL not only dose-dependently suppressed the spontaneous pain behaviors, but also relieved mechanical and thermal hypersensitivity induced by formalin hindpaw injection. Consistent with the analgesic effects of DUL on the pain behaviors, the expressions of Fos and pERK that were used to check the neuronal activities in the spinal cord and CeA were also dose-dependently reduced following DUL pretreatment. Meanwhile, no emotional aversive behaviors were observed at 24 h after formalin injection. The concentration of 5-HT in the CeA was correlated with the dose of DUL in a positive manner at 24 h after formalin injection. Direct injecting 5-HT into the CeA suppressed both the spontaneous pain behaviors and hyperalgesia induced by formalin injection. However, DUL did not have protective effects on the formalin-induced edema of hindpaw. In sum, the activation of CeA neurons may account for the transition from acute pain to long-term hyperalgesia after formalin injection. DUL may produce potent analgesic effects on the hyperalgesia and decrease the expressions of p-ERK through increasing the concentration of serotonin in the CeA. PMID:29692727

Analgesic Effects of Duloxetine on Formalin-Induced Hyperalgesia and Its Underlying Mechanisms in the CeA.

PubMed

Zhang, Lie; Yin, Jun-Bin; Hu, Wei; Zhao, Wen-Jun; Fan, Qing-Rong; Qiu, Zhi-Chun; He, Ming-Jie; Ding, Tan; Sun, Yan; Kaye, Alan D; Wang, En-Ren

2018-01-01

In rodents, the amygdala has been proposed to serve as a key center for the nociceptive perception. Previous studies have shown that extracellular signal-regulated kinase (ERK) signaling cascade in the central nucleus of amygdala (CeA) played a functional role in inflammation-induced peripheral hypersensitivity. Duloxetine (DUL), a serotonin and noradrenaline reuptake inhibitor, produced analgesia on formalin-induced spontaneous pain behaviors. However, it is still unclear whether single DUL pretreatment influences formalin-induced hypersensitivity and what is the underlying mechanism. In the current study, we revealed that systemic pretreatment with DUL not only dose-dependently suppressed the spontaneous pain behaviors, but also relieved mechanical and thermal hypersensitivity induced by formalin hindpaw injection. Consistent with the analgesic effects of DUL on the pain behaviors, the expressions of Fos and pERK that were used to check the neuronal activities in the spinal cord and CeA were also dose-dependently reduced following DUL pretreatment. Meanwhile, no emotional aversive behaviors were observed at 24 h after formalin injection. The concentration of 5-HT in the CeA was correlated with the dose of DUL in a positive manner at 24 h after formalin injection. Direct injecting 5-HT into the CeA suppressed both the spontaneous pain behaviors and hyperalgesia induced by formalin injection. However, DUL did not have protective effects on the formalin-induced edema of hindpaw. In sum, the activation of CeA neurons may account for the transition from acute pain to long-term hyperalgesia after formalin injection. DUL may produce potent analgesic effects on the hyperalgesia and decrease the expressions of p-ERK through increasing the concentration of serotonin in the CeA.

Chronic ethanol exposure decreases CB1 receptor function at GABAergic synapses in the rat central amygdala

PubMed Central

Varodayan, Florence P.; Soni, Neeraj; Bajo, Michal; Luu, George; Madamba, Samuel G.; Schweitzer, Paul; Parsons, Loren H.; Roberto, Marisa

2015-01-01

The endogenous cannabinoids (eCBs) influence the acute response to ethanol and the development of tolerance, dependence and relapse. Chronic alcohol exposure alters eCB levels and type 1 cannabinoid receptor (CB1) expression and function in brain regions associated with addiction. CB1 inhibits GABA release, and GABAergic dysregulation in the central nucleus of the amygdala (CeA) is critical in the transition to alcohol dependence. We investigated possible disruptions in CB1 signaling of rat CeA GABAergic transmission following intermittent ethanol exposure. In the CeA of alcohol-naïve rats, CB1 agonist WIN 55,212-2 (WIN) decreased the frequency of spontaneous and miniature GABAA receptor-mediated inhibitory postsynaptic currents (s/mIPSCs). This effect was prevented by CB1 antagonism, but not type 2 cannabinoid receptor (CB2) antagonism. After 2–3 weeks of intermittent ethanol exposure, these WIN inhibitory effects were attenuated, suggesting ethanol-induced impairments in CB1 function. The CB1 antagonist AM251 revealed a tonic eCB/CB1 control of GABAergic transmission in the alcohol-naïve CeA that was occluded by calcium chelation in the postsynaptic cell. Chronic ethanol exposure abolished this tonic CB1 influence on mIPSC, but not sIPSC, frequency. Finally, acute ethanol increased CeA GABA release in both naïve and ethanol exposed rats. Although CB1 activation prevented this effect, the AM251- and ethanol-induced GABA release were additive, ruling out a direct participation of CB1 signaling in the ethanol effect. Collectively, these observations demonstrate an important CB1 influence on CeA GABAergic transmission and indicate that the CeA is particularly sensitive to alcohol-induced disruptions of CB1 signaling. PMID:25940135

Mechanisms and Mitigation of Hearing Loss from Blast Injury

DTIC Science & Technology

2013-10-01

Approuvé par: Approved by: Page #: Échelle / Scale: Numéro Dessin / Drawing Nbr : Titre / Title: Mise en plan par: Drawn by: Date: Finition: Pièce...horn and exible rubber coupling will be replaced with larger PVC sections. � The cross-sectional area of the horn will be reduced smoothly, and the

Evaluation of a multiarray system for pharmaceutical analysis by microemulsion electrokinetic chromatography.

PubMed

Lynen, Frederic; Saavedra, Luis; Saveedra, Luis; Nickerson, Beverly; Sandra, Pat

2011-05-15

A multiplexed capillary electrophoresis (CE) system equipped with 96 channels was evaluated for high-throughput screening in drug discovery by microemulsion electrokinetic chromatography (MEEKC). Method transfer from a single channel to a multichannel CE system is described. Loss of efficiency and reduced migration times could be elucidated to the poor efficacy in Joule heat dissipation by forced air cooling in the multiarray system compared to liquid cooling in the single channel instrument. On the other hand, only 48 channels could actually be used because of the maximum total current of 3 mA. Precision data remained below 8% and 9% for migration times and peak areas, respectively. Some UV-detector cross-talk interference between neighboring capillary channels was noted. Impurities at 0.5% compared to the main peak (100%) could be detected with the multiplexed system which is 10 times lower compared to the single capillary system. Higher efficiency and improved figures of merit (absolute sensitivity and no cross-talk interferences) were obtained by using an array of only 24 capillaries. Copyright © 2011 Elsevier B.V. All rights reserved.

Pressure effects on the electronic properties in CeCoIn5: A first-principle study

NASA Astrophysics Data System (ADS)

Medeiros, Gustavo; Gonzalez, J. L.; Scopel, Wanderlã L.

2017-11-01

Superconducting heavy fermions are exotic materials with strong electronic correlations. The temperature-pressure phase diagrams of some of these materials show a complex interplay between superconductivity and magnetism that is essential to understand the physical properties of these systems. In this work, first principle calculations are performed in order to study the pressure effects on the electronic correlations in the CeCoIn5 system, which is superconducting at ambient pressure with Tc = 2.3 K. The density functional theory (DFT) method was used to include on-site coulomb repulsions (U) at the d (Co and In) and f (Ce) electrons of the CeCoIn5 compound. External applied pressures were simulated by correlating an applied pressure with a reduction of the volume of the unit cell, but keeping constant the c/a relation, as reported in experiments. Our findings reveal that the U parameters for all atomic species increase linearly with the pressure (P), being this effect higher for the f-electrons of the cerium ions, where dU / dP = 1.2 eV/GPa. In summary, these results not only suggest that the pressure effect can be correlated with an increase in the electronic correlations in the CeCoIn5 compound, as also, the work allows quantify this effect.

Heme Oxygenase-1 Protects Corexit 9500A-Induced Respiratory Epithelial Injury across Species

PubMed Central

Oliva, Octavio M.; Karki, Suman; Surolia, Ranu; Wang, Zheng; Watson, R. Douglas; Thannickal, Victor J.; Powell, Mickie; Watts, Stephen; Kulkarni, Tejaswini; Batra, Hitesh; Bolisetty, Subhashini; Agarwal, Anupam; Antony, Veena B.

2015-01-01

The effects of Corexit 9500A (CE) on respiratory epithelial surfaces of terrestrial mammals and marine animals are largely unknown. This study investigated the role of CE-induced heme oxygenase-1 (HO-1), a cytoprotective enzyme with anti-apoptotic and antioxidant activity, in human bronchial airway epithelium and the gills of exposed aquatic animals. We evaluated CE-mediated alterations in human airway epithelial cells, mice lungs and gills from zebrafish and blue crabs. Our results demonstrated that CE induced an increase in gill epithelial edema and human epithelial monolayer permeability, suggesting an acute injury caused by CE exposure. CE induced the expression of HO-1 as well as C-reactive protein (CRP) and NADPH oxidase 4 (NOX4), which are associated with ROS production. Importantly, CE induced caspase-3 activation and subsequent apoptosis of epithelial cells. The expression of the intercellular junctional proteins, such as tight junction proteins occludin, zonula occludens (ZO-1), ZO-2 and adherens junctional proteins E-cadherin and Focal Adhesion Kinase (FAK), were remarkably inhibited by CE, suggesting that these proteins are involved in CE-induced increased permeability and subsequent apoptosis. The cytoskeletal protein F-actin was also disrupted by CE. Treatment with carbon monoxide releasing molecule-2 (CORM-2) significantly inhibited CE-induced ROS production, while the addition of HO-1 inhibitor, significantly increased CE-induced ROS production and apoptosis, suggesting a protective role of HO-1 or its reaction product, CO, in CE-induced apoptosis. Using HO-1 knockout mice, we further demonstrated that HO-1 protected against CE-induced inflammation and cellular apoptosis and corrected CE-mediated inhibition of E-cadherin and FAK. These observations suggest that CE activates CRP and NOX4-mediated ROS production, alters permeability by inhibition of junctional proteins, and leads to caspase-3 dependent apoptosis of epithelial cells, while HO-1 and its reaction products protect against oxidative stress and apoptosis. PMID:25835394

Photoluminescence properties of phosphors based on Lu3+-stabilized Gd3Al5O12:Tb3+/Ce3+ garnet solid solutions

NASA Astrophysics Data System (ADS)

Li, Jinkai; Li, Ji-Guang; Li, Xiaodong; Sun, Xudong

2016-12-01

The Gd3Al5O12:Tb/Ce (GdAG:Tb/Ce) garnet solutions effectively stabilized by Lu3+ have been achieved by calcining their precursor at 1300 °C. Detailed characterizations are given to the materials in terms of XRD, FE-SEM, BET, PL/PLE, and fluorescence decay analysis. The occurrence of Gd3+ and Tb3+ transitions from the photoluminescence excitation spectrum monitoring the Ce3+ yellow emission strongly confirmed the efficient Gd3+ → Ce3+ and Tb3+ → Ce3+ energy transfer. The [(Gd0.8Lu0.2)0.99-xCe0.01Tbx]AG (x = 0-0.1) phosphors with good dispersion and uniform particle size exhibit various luminescent properties under different excitation wavelength of 275, 338, and 457 nm, respectively. The photoluminescence comparison indicated that owing to the Gd3+ → Ce3+ and Tb3+ → Ce3+ energy transfer, the best luminescent phosphor [(Gd0.8Lu0.2)0.89Ce0.01 Tb0.1]AG is almost identical to the well-known YAG:Ce, higher than LuAG:Ce in emission intensity, and has a substantially red-shifted emission band that is desired for warm-white lighting. The Tb3+ → Ce3+ energy transfer was suggested to be electric multipolar interactions, and the processes of energy migration among the optically active Gd3+, Tb3+, and Ce3+ ions were discussed in detail. Fluorescence decay analysis found the lifetime for the Ce3+ emission hardly changes with the Tb3+ incorporation. The [(Gd0.8Lu0.2)0.99-xCe0.01Tbx]AG garnets developed in this work may serve as a new type of phosphor that hopefully meets the requirements of various lighting, optical display, and scintillation applications.

Inhomogenous Broadening, Charge Compensation, and Luminescence Quenching in Ce 3+-Doped Sr 3AlO 4F Phosphors

DOE PAGES

Setlur, A. A.; Porob, D. G.; Happek, U.; ...

2015-09-24

The local coordination around luminescent ions in phosphors can affect the properties of these materials. Here, we analyze the Ce 3+ luminescence for the various Ce 3+ centers in Sr 3AlO 4F-based phosphors and use the excitation, emission, and quenching of these phosphors to infer aspects of the local coordination. It is shown that Ce 3+ centers with lower energy 4f 1→5d 1 absorption bands are likely from charge compensation effects by the replacement of F - by O 2-. In addition, at higher RE 3+ concentrations, additional Ce 3+ centers with even lower energy 4f 1→5d 1 absorption bandsmore » are present, presumably due to Ce 3+-RE 3+ pair formation and O 2- charge compensation. These Ce 3+ centers with lower energy 4f 1→5d 1 absorption bands have their luminescence strongly quenched at room temperature. The relationships between composition and Ce 3+ luminescence quenching for Sr 3AlO 4F-based phosphors are also discussed, giving evidence that Ce 3+(5d 1) ionization is the main cause for luminescence quenching in these materials.« less

Site Occupancies, Luminescence, and Thermometric Properties of LiY9(SiO4)6O2:Ce3+ Phosphors.

PubMed

Zhou, Weijie; Pan, Fengjuan; Zhou, Lei; Hou, Dejian; Huang, Yan; Tao, Ye; Liang, Hongbin

2016-10-04

In this work, we report the tunable emission properties of Ce 3+ in an apatite-type LiY 9 (SiO 4 ) 6 O 2 compound via adjusting the doping concentration or temperature. The occupancies of Ce 3+ ions at two different sites (Wyckoff 6h and 4f sites) in LiY 9 (SiO 4 ) 6 O 2 have been determined by Rietveld refinements. Two kinds of Ce 3+ f-d transitions have been studied in detail and then assigned to certain sites. The effects of temperature and doping concentration on Ce 3+ luminescence properties have been systematically investigated. It is found that the Ce 3+ ions prefer occupying Wyckoff 6h sites and the energy transfer between Ce 3+ at two sites becomes more efficient with an increase in doping concentration. In addition, the charge-transfer vibronic exciton (CTVE) induced by the existence of free oxygen ion plays an important role in the thermal quenching of Ce 3+ at 6h sites. Because of the tunable emissions from cyan to blue with increasing temperature, the phosphors LiY 9 (SiO 4 ) 6 O 2 :Ce 3+ are endowed with possible thermometric applications.

Cactus (Opuntia humifusa) water extract ameliorates loperamide-induced constipation in rats.

PubMed

Han, Sung Hee; Park, Kyungmi; Kim, Eun Young; Ahn, So Hyun; Lee, Hyun-Sun; Suh, Hyung Joo

2017-01-17

Korean cactus Cheonnyuncho (Opuntia humifusa) is rich in pectin, phenols, flavonoids, and minerals such as calcium and phosphorus. Some Koreans drink Cheonnyuncho juice prepared by grinding Cheonnyuncho with water. Cheonnyuncho is well known for its functional properties and antioxidant effects, but its effect on constipation has not been sufficiently studied. Loperamide (2 mg/kg) was injected subcutaneously to induce constipation in rats. The animals were divided into four groups: a normal group (NOR), constipation control group (CON), and two constipation groups receiving the Cheonnyuncho extract (CE) at two different concentrations in drinking water, 3% (L-CE group) and 6% (H-CE group), for 25 days. The fecal pellet numbers of NOR and L-CE were significantly increased from 35.67 ± 2.09 (CON) to 50.60 ± 1.38 and 46.50 ± 2.91 after loperamide treatment, respectively (p < 0.05). The water content of fecal excretions was significantly enhanced in only the L-CE group (33.05 ± 0.49%) compared to control (23.38 ± 1.26%) (p < 0.05) after loperamide treatment. The oral intake of CE (L-CE and H-CE groups) significantly increased levels of the intestinal transit ratio (45.25 ± 1.86% and 41.05 ± 2.47%, respectively) compared to the CON group (32.15 ± 2.05%) (p < 0.05). Treatment with the low concentration of CE significantly increased fecal levels of acetic, propionic, butyric, and valeric acids, as well as the total short-chain fatty acid (SCFA) concentration. Histological analyses revealed that the thickness of the distal colon also increased in the CE-treated groups in a dose-dependent manner. Constipation decreased when CE was fed to the rats. In particular, the fecal pellet number and water content, as well as histological parameters such as distal colon thickness, improved. The CE treatment also increased the fecal SCFA content. These results show that the extract of Cheonnyuncho (O. humifusa) alleviated the symptoms of loperamide-induced constipation.

Cinnamon water extracts increase glucose uptake but inhibit adiponectin secretion in 3T3-L1 adipose cells.

PubMed

Roffey, Benjamin; Atwal, Avtar; Kubow, Stan

2006-08-01

The effects of three concentrations (0.2, 0.3, and 0.4 mg/mL) of a cinnamon extract (CE) (Cinnamomum zeylanicum) on glucose uptake and adiponectin secretion in 3T3-L1 adipocytes were examined in the presence and absence of 0.5 nM and 50 nM insulin. In the absence of insulin, adipocytes exposed to 0.2 mg/mL CE showed an approximate two-fold increase in glucose uptake relative to controls although glucose uptake was unaffected by the two higher concentrations of CE. No effect of CE on glucose uptake was noted in the presence of 0.5 nM insulin whereas the two highest concentrations (0.3 and 0.4 mg/mL) of CE showed a significant dose-dependent decrease in glucose uptake in the presence of 50 nM insulin. Treatment of the adipocytes with 50 nM wortmannin, an irreversible inhibitor of the p110 isoform of phosphoinositide 3'-kinase, was associated with complete inhibition of the stimulated glucose uptake induced by 0.2 mg/mL CE. Treatment of the adipocytes with 0.2 mg/mL CE was associated with an inhibition of adiponectin secretion to levels that were nondetectable. The present study indicates that although 0.2 mg/mL CE has insulin-mimetic action in 3T3-adipocytes in terms of glucose uptake, secretion of the antidiabetic hormone adiponectin is adversely affected.

The role of charge transfer in the oxidation state change of Ce atoms in the TM13-CeO2(111) systems (TM = Pd, Ag, Pt, Au): a DFT + U investigation.

PubMed

Tereshchuk, Polina; Freire, Rafael L H; Ungureanu, Crina G; Seminovski, Yohanna; Kiejna, Adam; Da Silva, Juarez L F

2015-05-28

Despite extensive studies of transition metal (TM) clusters supported on ceria (CeO2), fundamental issues such as the role of the TM atoms in the change in the oxidation state of Ce atoms are still not well understood. In this work, we report a theoretical investigation based on static and ab initio molecular dynamics density functional theory calculations of the interaction of 13-atom TM clusters (TM = Pd, Ag, Pt, Au) with the unreduced CeO2(111) surface represented by a large surface unit cell and employing Hubbard corrections for the strong on-site Coulomb correlation in the Ce f-electrons. We found that the TM13 clusters form pyramidal-like structures on CeO2(111) in the lowest energy configurations with the following stacking sequence, TM/TM4/TM8/CeO2(111), while TM13 adopts two-dimensional structures at high energy structures. TM13 induces a change in the oxidation state of few Ce atoms (3 of 16) located in the topmost Ce layer from Ce(IV) (itinerant Ce f-states) to Ce(III) (localized Ce f-states). There is a charge flow from the TM atoms to the CeO2(111) surface, which can be explained by the electronegativity difference between the TM (Pd, Ag, Pt, Au) and O atoms, however, the charge is not uniformly distributed on the topmost O layer due to the pressure induced by the TM13 clusters on the underlying O ions, which yields a decrease in the ionic charge of the O ions located below the cluster and an increase in the remaining O ions. Due to the charge flow mainly from the TM8-layer to the topmost O-layer, the charge cannot flow from the Ce(IV) atoms to the O atoms with the same magnitude as in the clean CeO2(111) surface. Consequently, the effective cationic charge decreases mainly for the Ce atoms that have a bond with the O atoms not located below the cluster, and hence, those Ce atoms change their oxidation state from IV to III. This increases the size of the Ce(III) compared with the Ce(IV) cations, which builds-in a strain within the topmost Ce layer, and hence, also affecting the location of the Ce(III) cations and the structure of the TM13 clusters.

Redox potentials and kinetics of the Ce 3+/Ce 4+ redox reaction and solubility of cerium sulfates in sulfuric acid solutions

NASA Astrophysics Data System (ADS)

Paulenova, A.; Creager, S. E.; Navratil, J. D.; Wei, Y.

Experimental work was performed with the aim of evaluating the Ce 4+/Ce 3+ redox couple in sulfuric acid electrolyte for use in redox flow battery (RFB) technology. The solubility of cerium sulfates in 0.1-4.0 M sulfuric acid at 20-60 °C was studied. A synergistic effect of both sulfuric acid concentration and temperature on the solubility of cerous sulfate was observed. The solubility of cerous sulfate significantly decreased with rising concentration of sulfuric acid and rising temperature, while the solubility of ceric sulfate goes through a significant maximum at 40 °C. Redox potentials and the kinetics of the cerous/ceric redox reaction were also studied under the same temperature-concentration conditions. The redox potentials were measured using the combined redox electrode (Pt-Ag/AgCl) in equimolar Ce 4+/Ce 3+ solutions (i.e.[Ce 3+]=[Ce 4+]) in sulfuric acid electrolyte. The Ce 3+/Ce 4+ redox potentials significantly decrease (i.e. shift to more negative values) with rising sulfuric acid concentration; a small maximum is observed at 40 °C. Cyclic voltammetric experiments confirmed slow electrochemical kinetics of the Ce 3+/Ce 4+ redox reaction on carbon glassy electrodes (CGEs) in sulfuric acid solutions. The observed dependencies of solubilities, the redox potentials and the kinetics of Ce 3+/Ce 4+ redox reaction on sulfuric acid concentration are thought to be the result of inequivalent complexation of the two redox species by sulfate anions: the ceric ion is much more strongly bound to sulfate than is the cerous ion. The best temperature-concentration conditions for the RFB electrolytes appear to be 40 °C and 1 M sulfuric acid, where the relatively good solubility of both cerium species, the maximum of redox potentials, and the more or less satisfying stability of CGE s were found. Even so, the relatively low solubility of cerium salts in sulfuric acid media and slow redox kinetics of the Ce 3+/Ce 4+ redox reaction at carbon indicate that the Ce 3+/Ce 4+ may not be well suited for use in RFB technology.

Mixed valency and site-preference chemistry for cerium and its compounds: A predictive density-functional theory study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alam, Aftab; Johnson, Duane D.

Cerium and its technologically relevant compounds are examples of anomalous mixed valency, originating from two competing oxidation states—itinerant Ce4+ and localized Ce3+. Under applied stress, anomalous transitions are observed but not well understood. Here we treat mixed valency as an “alloy” problem involving two valences with competing and numerous site-occupancy configurations. We use density-functional theory with Hubbard U (i.e., DFT+U) to evaluate the effective valence and predict properties, including controlling the valence by pseudoternary alloying. For Ce and its compounds, such as (Ce,La)2(Fe,Co)14B permanent magnets, we find a stable mixed-valent α state near the spectroscopic value of νs=3.53. Ce valencymore » in compounds depends on its steric volume and local chemistry. For La doping, Ce valency shifts towards γ-like Ce3+, as expected from steric volume; for Co doping, valency depends on local Ce-site chemistry and steric volume. Our approach captures the key origins of anomalous valency and site-preference chemistry in complex compounds.« less

Realizing luminescent downshifting in ZnO thin films by Ce doping with enhancement of photocatalytic activity

NASA Astrophysics Data System (ADS)

Narayanan, Nripasree; Deepak, N. K.

2018-04-01

ZnO thin films doped with Ce at different concentration were deposited on glass substrates by spray pyrolysis technique. XRD analysis revealed the phase purity and polycrystalline nature of the films with hexagonal wurtzite geometry and the composition analysis confirmed the incorporation of Ce in the ZnO lattice in the case of doped films. Crystalline quality and optical transmittance diminished while electrical conductivity enhanced with Ce doping. Ce doping resulted in a red-shift of optical energy gap due to the downshift of the conduction band minimum after merging with Ce related impurity bands formed below the conduction band in the forbidden gap. In the room temperature photoluminescence spectra, UV emission intensity of the doped films decreased while the intensity of the visible emission band increased drastically implying the degradation in crystallinity as well as the incorporation of defect levels capable of luminescence downshifting. Ce doping showed improvement in photocatalytic efficiency by effectively trapping the free carriers and then transferring for dye degradation. Thus Ce doped ZnO thin films are capable of acting as luminescent downshifters as well as efficient photocatalysts.

Surface nucleation and independent growth of Ce(OH)4 within confinement space on modified carbon black surface to prepare nano-CeO2 without agglomeration

NASA Astrophysics Data System (ADS)

Zhang, Xinyue; Xia, Chunhui; Li, Kaitao; Lin, Yanjun

2018-06-01

Highly dispersed negative carboxyl groups can be formed on carbon black (CB) surface modified with strong nitric acid. Therefore positive cations can be uniformly absorbed by carboxyl groups and precipitated within a confinement space on modified CB surface to prepare highly dispersed nanomaterials. In this paper, the formation and dispersion status of surface negative carboxyl groups, adsorption status of Ce3+, surface confinement nucleation, crystallization and calcination process were studied by EDS, SEM, and laser particle size analysis. The results show that the carboxyl groups formed on modified CB surface are highly dispersed, and Ce3+ cations can be uniformly anchored by carboxyl groups. Therefore, highly dispersed Ce3+ can react with OH- within a confinement surface region to form positive nano-Ce(OH)4 nuclei which also can be adsorbed by electrostatic attraction. After independent growth of Ce(OH)4 without agglomeration, highly dispersed CeO2 nanoparticles without agglomeration can be prepared together with the help of effectively isolates by CO2 released in the combustion of CB.

Electrochemical Impedance Spectroscopy and Corrosion Behavior of Co/CeO2 Nanocomposite Coatings in Simulating Body Fluid Solution

NASA Astrophysics Data System (ADS)

Benea, Lidia

2013-02-01

A series of Co/CeO2 (25 nm) nanocomposite coating materials by electrodeposition were successfully prepared containing different cerium oxide composition in the cobalt-plating bath. Stainless steel (304L) was used as support material for nanocomposite coatings. The nano-CeO2 is uniformly incorporated into cobalt matrix, and the effect on surface morphologies was identified by scanning electron microscopy with energy-dispersive X-ray analysis. Codeposition of nano-CeO2 particles with cobalt disturbs the regular surface morphology of the cobalt coatings. It should be noted that the as-prepared Co/CeO2 nanocomposite coatings were found to be much superior in corrosion resistance over those of pure cobalt coatings materials based on a series of electrochemical impedance spectroscopy measurements in simulating body fluid solution. With increase in the nano-CeO2 particles concentration in the cobalt electrolyte, it is observed that the corrosion resistance of Co/CeO2 increases. Co/CeO2 nanocomposite coatings have higher polarization resistance as compared with pure cobalt layers in simulating body fluid solution.

Surface nucleation and independent growth of Ce(OH)4 within confinement space on modified carbon black surface to prepare nano-CeO2 without agglomeration

NASA Astrophysics Data System (ADS)

Zhang, Xinyue; Xia, Chunhui; Li, Kaitao; Lin, Yanjun

2018-04-01

Highly dispersed negative carboxyl groups can be formed on carbon black (CB) surface modified with strong nitric acid. Therefore positive cations can be uniformly absorbed by carboxyl groups and precipitated within a confinement space on modified CB surface to prepare highly dispersed nanomaterials. In this paper, the formation and dispersion status of surface negative carboxyl groups, adsorption status of Ce3+, surface confinement nucleation, crystallization and calcination process were studied by EDS, SEM, and laser particle size analysis. The results show that the carboxyl groups formed on modified CB surface are highly dispersed, and Ce3+ cations can be uniformly anchored by carboxyl groups. Therefore, highly dispersed Ce3+ can react with OH- within a confinement surface region to form positive nano-Ce(OH)4 nuclei which also can be adsorbed by electrostatic attraction. After independent growth of Ce(OH)4 without agglomeration, highly dispersed CeO2 nanoparticles without agglomeration can be prepared together with the help of effectively isolates by CO2 released in the combustion of CB.

Study of energy transfer and spectral downshifting in Ce, RE (RE = Nd and Yb) co-doped lanthanum phosphate

NASA Astrophysics Data System (ADS)

Sawala, N. S.; Omanwar, S. K.

2017-03-01

The phosphors LaPO4 (Lanthanum phosphate) doped with Ce(III)/Ce3+ and co-doped with Ce3+-Nd3+ and Ce3+-Yb3+ were effectively synthesized by conventional solid state reaction method. The prepared samples were characterized by powder X-ray diffraction (XRD) and surface morphology was studied by scanning electronic microscope (SEM). The photoluminescence (PL) properties were studied by spectrophotometers in near infrared (NIR) and ultraviolet visible (UV-VIS) region. Additionally the luminescence time decay curves of samples were investigated to confirm energy transfer (ET) process. The Ce3+-Nd3+ ion co-doped LaPO4 phosphors can convert a photon of UV region (278 nm) into photons of NIR region (1058 nm). While Ce3+-Yb3+ ion doped LaPO4 phosphors convert photons of UV region (278 nm) into photons of NIR region (979 nm). The Ce3+ ion acts like sensitizer and Nd3+/Yb3+ ions act as activators. Both kinds of emissions are suitable for improving spectral response of solar cells.

Lu1-xI3:Cex--A Scintillator for gamma ray spectroscopy and time-of-flight PET

DOEpatents

Shah, Kanai S [Newton, MA

2009-03-17

The present invention concerns very fast scintillator materials comprising lutetium iodide doped with Cerium Lu.sub.1-xI.sub.3:Ce.sub.x; LuI.sub.3:Ce). The LuI.sub.3 scintillator material has surprisingly good characteristics including high light output, high gamma ray stopping efficiency, fast response, low cost, good proportionality, and minimal afterglow that the material is useful for gamma ray spectroscopy, medical imaging, nuclear and high energy physics research, diffraction, non-destructive testing, nuclear treaty verification and safeguards, and geological exploration. The timing resolution of the scintillators of the present invention provide compositions capable of resolving the position of an annihilation event within a portion of a human body cross-section.

Rational design of octahedron and nanowire CeO2@MnO2 core-shell heterostructures with outstanding rate capability for asymmetric supercapacitors.

PubMed

Zhu, Shi Jin; Jia, Jia Qi; Wang, Tian; Zhao, Dong; Yang, Jian; Dong, Fan; Shang, Zheng Guo; Zhang, Yu Xin

2015-10-14

Two kinds of novel CeO2@MnO2 nanostructures have been synthesized via a self-assembly strategy. The as-prepared CeO2 nanowire@MnO2 nanostructures exhibited unprecedented pseudocapacitance performance (255 F g(-1)) with outstanding rate capability. A new mechanism based on the synergistic effect between CeO2 and MnO2 was proposed to interpret this phenomenon. When assembled as an asymmetric supercapacitor, an energy density of 27.5 W h kg(-1) with a maximum power density of 1.6 kW kg(-1) was achieved for CeO2 nanowire@MnO2 nanostructures.

The use of catalyst to enhance the wet oxidation process.

PubMed

Maugans, C; Kumfer, B

2007-01-01

Wet oxidation tests were performed on two pure compound streams: acetic acid and ammonia; and on two wastewater streams: acrylic acid wastewater and sulphide laden spent caustic. Test results showed that Mn/Ce and Pt/TiO2 were effective catalysts that greatly enhanced acetic acid, ammonia and acrylic acid wastewater destruction. However, the Mn/Ce catalyst performance appears to be inhibited by concentrated salts dissolved in solution. This could limit the applicability of this catalyst for the treatment of brackish wastewaters. Zr, Ce and Ce nanoparticles were also shown to exhibit some catalytic activity, however not to the extent of the Mn/Ce and the Pt/TiO2.

Effects of steaming on contaminants of emerging concern levels in seafood.

PubMed

Barbosa, Vera; Maulvault, Ana Luísa; Alves, Ricardo N; Kwadijk, Christian; Kotterman, Michiel; Tediosi, Alice; Fernández-Tejedor, Margarita; Sloth, Jens J; Granby, Kit; Rasmussen, Rie R; Robbens, Johan; De Witte, Bavo; Trabalón, Laura; Fernandes, José O; Cunha, Sara C; Marques, António

2018-05-19

Seafood consumption is a major route for human exposure to environmental contaminants of emerging concern (CeCs). However, toxicological information about the presence of CeCs in seafood is still insufficient, especially considering the effect of cooking procedures on contaminant levels. This study is one among a few who evaluated the effect of steaming on the levels of different CeCs (toxic elements, PFCs, PAHs, musk fragrances and UV-filters) in commercially relevant seafood in Europe, and estimate the potential risks associated with its consumption for consumers. In most cases, an increase in contaminant levels was observed after steaming, though varying according to contaminant and seafood species (e.g. iAs, perfluorobutanoate, dibenzo(ah)anthracene in Mytilus edulis, HHCB-Lactone in Solea sp., 2-Ethylhexyl salicylate in Lophius piscatorius). Furthermore, the increase in some CeCs, like Pb, MeHg, iAs, Cd and carcinogenic PAHs, in seafood after steaming reveals that adverse health effects can never be excluded, regardless contaminants concentration. However, the risk of adverse effects can vary. The drastic changes induced by steaming suggest that the effect of cooking should be integrated in food risk assessment, as well as accounted in CeCs regulations and recommendations issued by food safety authorities, in order to avoid over/underestimation of risks for consumer health. Copyright © 2018 Elsevier Ltd. All rights reserved.

Anodized porous titanium coated with Ni-CeO2 deposits for enhancing surface toughness and wear resistance

NASA Astrophysics Data System (ADS)

Zhou, Xiaowei; Ouyang, Chun

2017-05-01

In order to make large improvements of surface toughness and wear resistance for pure titanium (Ti) substrate, anodic titanium oxide (ATO) surface with nanoporous structure was coated with the Ni-CeO2 nanocomposite coatings. Regarding TiO2 barrier layer on Ti surface to inhibit its electrochemical activity, pre-treatments were successively processed with anodizing, sensitizing, activating, and then followed by electroless Ni-P film to be acted as an activated layer for electroplating Ni-CeO2 deposits. The existing Pd atoms around ATO nanopores were expected as the heterogeneous nucleation sites for supporting the growing locations of electroless Ni-P film. The innovative of interface design using porous structure was introduced for bonding pinholes to achieve a metallurgical adhesion interface between Ti substrate and surface coatings. Besides the objectives of this work were to elucidate how effects by the adding CeO2 nanoparticles on modifying microstructures and wear mechanisms of Ni-CeO2 nanocomposite coatings. Many efforts of XRD, FE-SEM, TEM and Nanoindentation tests were devoted to comparing different wear behaviors of Ni-CeO2 coatings relative to pure nickel. Results indicated that uniform-distributed Ti nanopores with an average diameter size of ∼200 nm was achieved using the Phosphate-type anodizing solution at DC 150 V. A worn surface without fatigue cracks was observed for TAO surface coated with Ni-CeO2 deposits, showing the existing Ce-rich worn products to be acted as a solid lubricant phase for making a self-healing effect on de-lamination failures. More important, this finding will be the guidelines for Ce-rich precipitations to be expected as the strengthening phase in anodized porous of Ti, Al and Mg alloys for intensifying their surface properties.

Cannabis for Cognitive Enhancement as a New Coping Strategy? Results From a Survey of Students at Four Universities in Germany.

PubMed

Franke, Andreas G; Roser, Patrik; Lieb, Klaus; Vollmann, Jochen; Schildmann, Jan

2016-12-05

Cognitive Enhancement (CE) is often discussed in relation to stimulant drugs, such as amphetamines (AMPH). However, there is some evidence that cannabis (CAN) can be used for CE. This study compares the knowledge, prevalence, and perceived effects of and factors associated with the knowledge of or use of CAN versus AMPH for CE among undergraduate students at four German universities. A survey was taken of 1,538 students at four German universities. It investigated their knowledge and use of CAN and AMPH for CE as well as associated factors. Descriptive and analytic (Mann-Whitney-U test, Fisher's exact test, logistic regression) statistics were obtained using SPSS. Responses were obtained from 1,026 participants (57.2%) at three universities from the Universitätsallianz Metropole Ruhr (UAR) (Bochum, Dortmund, Duisburg-Essen) and 512 respondents (68.3%) in Mainz. We observed lifetime prevalence rates of 3.5% for the use of CAN and 2.1% for the use of AMPH for the purpose of CE. CAN users perceived pressure to perform as more of a burden than AMPH users (mean: 3.2, CAN users: 4.7, AMPH: 2.9; p =.042). CAN users used the substances for studying for exams significantly less often than AMPH users (p =.025), and CAN users perceived less of an enhancing effect of the drug compared to AMPH users (p <.001). A considerable number of students report having used CAN for CE. However, our research indicates differences in perceptions and experiences of CE between CAN and AMPH users. Further research on the role of CAN for CE and conceptual analyses to differentiate between different understandings of CE are warranted.

Systemic administration of vitamins C and E attenuates nociception induced by chronic constriction injury of the sciatic nerve in rats.

PubMed

Riffel, Ana Paula K; de Souza, Jéssica A; Santos, Maria do Carmo Q; Horst, Andréa; Scheid, Taína; Kolberg, Carolina; Belló-Klein, Adriane; Partata, Wania A

2016-03-01

Antioxidants have been tested to treat neuropathic pain, and α-Tocopherol (vitamin E--vit. E) and ascorbic acid (vitamin C--vit. C) are potent antioxidants. We assessed the effect of intraperitoneal administration of vit. C (30 mg/kg/day) and vit. E (15 mg/kg/day), given alone or in combination, on the mechanical and thermal thresholds and the sciatic functional index (SFI) in rats with chronic constriction injury (CCI) of the sciatic nerve. We also determined the lipid hydroperoxides and total antioxidant capacity (TAC) in the injured sciatic nerve. Further, we assessed the effects of oral administration of vit. C+vit. E (vit. C+E) and of a combination of vit. C+E and gabapentin (100mg/kg/day, i.p.) on the mechanical and thermal thresholds of CCI rats. The vitamins, whether administered orally or i.p., attenuated the reductions in the mechanical and thermal thresholds induced by CCI. The antinociceptive effect was greater with a combination of vit. C+E than with each vitamin given alone. The SFI was also improved in vitamin-treated CCI rats. Co-administration of vit. C+E and gabapentin induced a greater antinociceptive effect than gabapentin alone. No significant change occurred in TAC and lipid hydroperoxide levels, but TAC increased (45%) while lipid hydroperoxides decreased (38%) in the sciatic nerve from vit. C+E-treated CCI rats. Thus, treatment with a combination of vit. C+E was more effective to treat CCI-induced neuropathic pain than vitamins alone, and the antinociceptive effect was greater with co-administration of vit. C+E and gabapentin than with gabapentin alone. Copyright © 2016 Elsevier Inc. All rights reserved.

Socio-ecological transitions trigger fire regime shifts and modulate fire-climate interactions in the Sierra Nevada, CA, 1600-2015 CE

NASA Astrophysics Data System (ADS)

Trouet, V.; Taylor, A. H.; Skinner, C. N.; Stephens, S.

2016-12-01

In California, large wildfires cause significant socio-ecological impacts and they incur high federal funding costs for fire suppression. Future fire activity is projected to increase with climate change, but anthropogenic effects can modulate or even override climatic effects causing large uncertainty in fire projections. We developed a 415-year fire history record (1600-2015 CE) based on tree-ring fire-scar data from 29 sites throughout the Sierra Nevada, California. Changes in socio-ecological systems from the Native American to the current period drove large historical fire regime shifts in our record and socio-ecological conditions amplified and buffered fire response to climate. Fire activity was highest and fire-climate relationships were strongest after Native American depopulation - following mission establishment ca. 1775 CE - reduced the self-limiting effect of Native American burns on fire spread. With the Gold Rush and Euro-American immigration (ca. 1865 CE), area burned declined and the strong multidecadal relationship between temperature and fire decayed and then disappeared after implementation of fire suppression (ca. 1900 CE). The past anthropogenic modulation of fire-climate relationships underscores the need for nuanced representations of human-fire interactions to improve the skill of future fire-climate projections. In California, large wildfires cause significant socio-ecological impacts and they incur high federal funding costs for fire suppression. Future fire activity is projected to increase with climate change, but anthropogenic effects can modulate or even override climatic effects causing large uncertainty in fire projections. We developed a 415-year fire history record (1600-2015 CE) based on tree-ring fire-scar data from 29 sites throughout the Sierra Nevada, California. Changes in socio-ecological systems from the Native American to the current period drove large historical fire regime shifts in our record and socio-ecological conditions amplified and buffered fire response to climate. Fire activity was highest and fire-climate relationships were strongest after Native American depopulation - following mission establishment ca. 1775 CE - reduced the self-limiting effect of Native American burns on fire spread. With the Gold Rush and Euro-American immigration (ca. 1865 CE), area burned declined and the strong multidecadal relationship between temperature and fire decayed and then disappeared after implementation of fire suppression (ca. 1900 CE). The past anthropogenic modulation of fire-climate relationships underscores the need for nuanced representations of human-fire interactions to improve the skill of future fire-climate projections.

Competing pseudogap and impurity effects on the normal-state specific heat properties of cuprate superconductors

NASA Astrophysics Data System (ADS)

Dzhumanov, S.; Karimboev, E. X.

2014-07-01

In this paper, we show that the pseudogap in the excitation spectra of high-Tc cuprates together with the impurity phase and charge inhomogeneity plays key roles in determining the essential features of their anomalous specific heat properties observed above Tc. We consider the doped cuprate superconductor as a multi-carrier model system (which consists of intrinsic and extrinsic polarons and pre-formed bosonic Cooper pairs) and study the competing pseudogap and impurity effects on the normal-state electronic specific heat of high-Tc cuprates taking into account charge inhomogeneities. We argue that unconventional electron-phonon interactions are responsible for the precursor Cooper pairing in the polaronic band below a mean-field temperature T∗ and the existence of a pseudogap above Tc in the cuprates. The electronic specific heat Ce(T) of doped cuprates below T∗ is calculated taking into account three contributions coming from the excited components of Cooper pairs, the ideal Bose-gas of incoherent Cooper pairs and the unpaired carriers in the impurity band. Above T∗, two contributions to Ce(T) coming from the unpaired intrinsic and extrinsic polarons are calculated within the two-component degenerate Fermi-gas model. By comparing our results with the experimental Ce(T) data obtained for La- and Y-based cuprates, we find that the observed behaviors of Ce(T) (below and above T∗) are similar to the calculated results for Ce(T) and the BCS-type jumps of Ce(T) at T∗ may be depressed by the impurity effects and may become more or less pronounced BCS-type anomalies in Ce(T) .

What part of working memory is not working in ADHD? Short-term memory, the central executive and effects of reinforcement.

PubMed

Dovis, Sebastiaan; Van der Oord, Saskia; Wiers, Reinout W; Prins, Pier J M

2013-08-01

Deficits in Working Memory (WM) are related to symptoms of Attention-Deficit/Hyperactivity Disorder (ADHD). In children with ADHD visuospatial WM is most impaired. WM is composed of Short-Term Memory (STM) and a Central Executive (CE). Therefore, deficits in either or both STM and the CE may account for WM impairments in children with ADHD. WM-component studies investigating this find deficits in both STM and the CE. However, recent studies show that not only cognitive deficits, but also motivational deficits give rise to the aberrant WM performance of children with ADHD. To date, the influence of these motivational deficits on the components of WM has not been investigated. This study examined the effects of a standard (feedback-only) and a high level of reinforcement (feedback + 10 euros) on the visuospatial WM-, visuospatial STM-, and the CE performance of 86 children with ADHD and 62 typically-developing controls. With standard reinforcement the STM, CE, and WM performance of children with ADHD was worse than that of controls. High reinforcement improved STM and WM performance more in children with ADHD than in controls, but was unable to normalize their performance. High reinforcement did not appear to improve the CE-related performance of children with ADHD and controls. Motivational deficits have a detrimental effect on both the visuospatial WM performance and the STM performance of children with ADHD. Aside from motivational deficits, both the visuospatial STM and the CE of children with ADHD are impaired, and give rise to their deficits in visuospatial WM.

Toxicity of binary mixtures of metal oxide nanoparticles to Nitrosomonas europaea.

PubMed

Yu, Ran; Wu, Junkang; Liu, Meiting; Zhu, Guangcan; Chen, Lianghui; Chang, Yan; Lu, Huijie

2016-06-01

Although the widely used metal oxide nanoparticles (NPs) titanium dioxide NPs (n-TiO2), cerium dioxide NPs (n-CeO2), and zinc oxide NPs (n-ZnO) have been well known for their potential cytotoxicities to environmental organisms, their combined effects have seldom been investigated. In this study, the short-term binary effect of n-CeO2 and n-TiO2 or n-ZnO on a model ammonia oxidizing bacterium, Nitrosomonas europaea were evaluated based on the examinations of cells' physiological, metabolic, and transcriptional responses. The addition of n-TiO2 mitigated the negative effect of more toxic n-CeO2 and the binary toxicity (antagonistic toxicity) of n-TiO2 and n-CeO2 was generally lower than the single NPs induced one. While the n-CeO2/n-ZnO mixture exerted higher cytotoxicity (synergistic cytotoxicity) than that from single NPs. The increased addition of the less toxic n-CeO2 exaggerated the binary toxicity of n-CeO2/n-ZnO mixture although the solubility of n-ZnO was not significantly affected, which excluded the contribution of the dissolved Zn ions to the enhancement of the combined cytotoxicity. The cell membrane disturbances and NP internalizations were detected for all the NP impacted cultures and the electrostatic interactions among the two distinct NPs and the cells were expected to play a key role in mediating their direct contacts and the eventual binary nanotoxicity to the cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Robustness of Cluster Expansion: Assessing the Role of Relaxation

NASA Astrophysics Data System (ADS)

Nguyen, Andrew H.; Rosenbrock, Conrad W.; Hart, Gus L. W.

Cluster expansion (CE) has been used widely in combination with first-principles calculations to predict stable structures of metal alloys. CE treats alloys as a purely configuration problem, i.e., a problem in the distribution of the alloying elements on a fixed lattice. CE models are usually built from data taken from ``relaxed'' first-principles calculations where the individual atoms assume positions that minimize the total energy. A perennial question in the cluster expansion community is how the accuracy of the CE is affected by relaxations--technically, the formalism of CE breaks down when the underlying lattice is not preserved--but practitioners often argue that there is a one-to-one correspondence between relaxed and unrelaxed structures so that the formalism holds. We quantify the effect of relaxation on the robustness of cluster expansions by comparing CE fits for relaxed and unrelaxed data sets. Our results give a heuristic for when CE models can be trusted. Onr (MURI N00014-13-1-0635).

Pt-Au/MOx-CeO₂ (M = Mn, Fe, Ti) Catalysts for the Co-Oxidation of CO and H₂ at Room Temperature.

PubMed

Hong, Xiaowei; Sun, Ye; Zhu, Tianle; Liu, Zhiming

2017-02-27

A series of nanostructured Pt-Au/MO x -CeO₂ (M = Mn, Fe, Ti) catalysts were prepared and their catalytic performance for the co-oxidation of carbon monoxide (CO) and hydrogen (H₂) were evaluated at room temperature. The results showed that MO x promoted the CO oxidation of Pt-Au/CeO₂, but only the TiO₂ could enhance co-oxidation of CO and H₂ over Pt-Au/CeO₂. Related characterizations were conducted to clarify the promoting effect of MO x . Temperature-programmed reduction of hydrogen (H₂-TPR) and X-ray photoelectron spectroscopy (XPS) results suggested that MO x could improve the charge transfer from Au sites to CeO₂, resulting in a high concentration of Ce 3+ and cationic Au species which benefits for the CO oxidation. In-situ diffuse reflectance infrared Fourier transform spectroscopy (In-situ DRIFTS) results indicated that TiO₂ could facilitate the oxidation of H₂ over the Pt-Au/TiO₂-CeO₂ catalyst.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelson, Nicholas C.; Boote, Brett W.; Naik, Pranjali

Ceria (CeO 2) and sodium-modified ceria (Ce-Na) were prepared through combustion synthesis. Palladium was deposited onto the supports (Pd/CeO 2 and Pd/Ce-Na) and their activity for the aqueous-phase transfer hydrogenation of phenol using 2-propanol under liquid flow conditions was studied. Pd/Ce-Na showed a marked increase (6×) in transfer hydrogenation activity over Pd/CeO 2. Material characterization indicated that water-stable sodium species were not doped into the ceria lattice, but rather existed as subsurface carbonates. Modification of ceria by sodium provided more adsorption and redox active sites (i.e. defects) for 2-propanol dehydrogenation. This effect was an intrinsic property of the Ce-Na supportmore » and independent of Pd. The redox sites active for 2-propanol dehydrogenation were thermodynamically equivalent on both supports/catalysts. At high phenol concentrations, the reaction was limited by 2-propanol adsorption. Furthermore, the difference in catalytic activity was attributed to the different numbers of 2-propanol adsorption and redox active sites on each catalyst.« less

Multiparity evaluation of calving ease and stillbirth with separate genetic effects by parity.

PubMed

Wiggans, G R; Cole, J B; Thornton, L L M

2008-08-01

Evaluations that analyze first and later parities as correlated traits were developed separately for calving ease (CE) from over 15 million calving records of Holsteins, Brown Swiss, and Holstein-Brown Swiss crossbreds and for stillbirth (SB) from 7.4 million of the Holstein CE records. Calving ease was measured on a scale of 1 (no difficulty) to 5 (difficult birth); SB status was designated as live or dead within 48 h. Scores for CE and SB were transformed separately for each trait by parity (first or later) and calf sex (male or female) and converted to a unit standard deviation scale. For variance component estimation, Holstein data were selected for the 2,968 bulls with the most records as sire or maternal grandsire (MGS). Six samples were selected by herd; samples ranged in size from 97,756 to 146,138 records. A multiparity sire-MGS model was used to calculate evaluations separately for CE and for SB with first and later parities as correlated traits. Fixed effects were year-season, calf sex, and sire and MGS birth years; random effects were herd-year interaction, sire, and MGS. For later parities, sex effects were separated by parity. The genetic correlation between first and later parities was 0.79 for sire and 0.81 for MGS for CE, and 0.83 for sire and 0.74 for MGS for SB. For national CE evaluations, which also include Brown Swiss, a fixed effect for breed was added to the model. Correlations between solutions on the underlying scale from the January 2008 USDA CE evaluation with those from the multiparity analysis for CE were 0.89 and 0.91 for first- and later-parity sire effects and 0.71 and 0.88 for first- and later-parity MGS effects; the larger value for later parity reflects that later parities comprised 64% of the data. Corresponding correlations for SB were 0.81 and 0.82 for first- and later-parity sire effects and 0.46 and 0.83 for first- and later-parity MGS effects, respectively. Correlations were higher when only bulls with a multiparity reliability of >65% were included. The multiparity analysis accounted for genetic differences in calving performance between first and later parities. Evaluations should become more stable as the portion of a bull's observations from different parities changes over his lifetime. Accuracy of the net merit index can be improved by adjusting weights to use evaluations for separate parities optimally.

Mandatory continuing education in physical therapy: survey of physical therapists in states with and states without a mandate.

PubMed

Landers, Merrill R; McWhorter, James W; Krum, Laura L; Glovinsky, David

2005-09-01

Although formal continuing education (CE) in physical therapy is one part of professional development, its value for renewing licensure is not shared by all states. The purpose of this study was to explore the differences in how physical therapists pursue formal continuing education on the basis of state mandate, sex, years of experience, practice specialty, American Physical Therapy Association membership, motivation, and perception of the benefits of CE. A survey questionnaire was sent to 3,000 physical therapists in 7 states--1,500 to physical therapists in states with mandatory CE and 1,500 to physical therapists in states without a requirement. A total of 1,145 usable survey questionnaires were returned, for a response rate of 38.2%. Physical therapists in states with mandatory CE averaged 33.8 hours of CE per year, whereas physical therapists in states without a mandate averaged 28.3 hours per year; 5.9% of therapists in states without a mandate reported taking no CE at all, and 10.8% reported taking 2 or fewer hours of CE within the preceding 5 years. No statistically significant relationships were observed between the amount of CE taken and years of experience, sex, or practice specialty. Therapists who reported membership in the American Physical Therapy Association participated in 7.2 more hours of CE per year than therapists who did not report membership. Significant motivational variables that respondents noted for taking CE were state mandate, increased clinical competence, and certification. Therapists overwhelmingly (96.2%) believed that CE had a beneficial effect on their clinical practice. Results from this study suggest that mandatory CE does have a significant association with the number of formal CE hours taken by physical therapists.

Is Routine Intraoperative Contrast-Enhanced Ultrasonography Useful During Whole Liver Transplantation?

PubMed

Golse, Nicolas; Santoni, Simone; Karam, Vincent; Ciacio, Oriana; Pittau, Gabriella; Allard, Marc-Antoine; Cherqui, Daniel; Sa Cunha, Antonio; Adam, René; Castaing, Denis; Vibert, Eric

2018-05-01

Vascular complications following liver transplantation (LT) may result from technical deficiencies. Intraoperative diagnosis remains challenging but can prevent serious delayed complications. Intraoperative Doppler ultrasonography (IOUS) represents the gold standard for imaging, although it requires radiological skills. Contrast-enhanced ultrasonography has been reported during postoperative assessments, but never intraoperatively (CE-IOUS). The aim of this study was to assess the feasibility of routine CE-IOUS, to evaluate its impact on surgical strategy and its usefulness. All 553 whole LTs performed in our tertiary centre between 01/2010 and 12/2014 were reviewed. We compared perioperative outcomes and long-term survival in IOUS (n = 370) versus CE-IOUS (n = 103) groups. Secondarily, the seven cases where the two imaging findings conflicted (CE+ Group) were matched 1:2 and compared with an exclusively IOUS procedure (CE- Group, n = 14) to assess the consequences of a specific CE-guided strategy. CE-IOUS assessments were successful in 100% of cases, without any adverse effects. Vascular complications and patient/graft survival rates were identical in the IOUS and CE-IOUS groups (p = 0.65, 0.95 and 0.86, respectively). CE-IOUS confirmed IOUS findings in 93% of cases (n = 96) and led to the realization of an additional procedure (median arcuate ligament lysis) and six conservative strategies despite poor arterial (n = 5) or venous flow (n = 1) under Doppler analysis. The CE+ and CE- groups presented statistically identical perioperative and long-term outcomes. This study demonstrated the feasibility of CE-IOUS during whole LT. However, we failed to demonstrate any advantages of CE-IOUS over IOUS. Therefore, IOUS currently remains the gold-standard imaging technique for the intraoperative assessment of vascular patency.

Poster — Thur Eve — 18: Cherenkov Emission By High-Energy Radiation Therapy Beams: A Characterization Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zlateva, Y.; El Naqa, I.; Quitoriano, N.

2014-08-15

We investigate Cherenkov emission (CE) by radiotherapy beams via radiation dose-versus-CE correlation analyses, CE detection optimization by means of a spectral shift towards the near-infrared (NIR) window of biological tissue, and comparison of CE to on-board MV imaging. Dose-CE correlation was investigated via simulation and experiment. A Monte Carlo (MC) CE simulator was designed using Geant4. Experimental phantoms include: water; tissue-simulating phantom composed of water, Intralipid®, and beef blood; plastic phantom with solid water insert. The detector system comprises an optical fiber and diffraction-grating spectrometer incorporating a front/back-illuminated CCD. The NIR shift was carried out with CdSe/ZnS quantum dots (QDs),more » emitting at (650±10) nm. CE and MV images were acquired with a CMOS camera and electronic portal imaging device. MC and experimental studies indicate a strong linear dose-CE correlation (Pearson coefficient > 0.99). CE by an 18-MeV beam was effectively NIR-shifted in water and a tissue-simulating phantom, exhibiting a significant increase at 650 nm for QD depths up to 10 mm. CE images exhibited relative contrast superior to MV images by a factor of 30. Our work supports the potential for application of CE in radiotherapy online imaging for patient setup and treatment verification, since CE is intrinsic to the beam and non-ionizing and QDs can be used to improve CE detectability, potentially yielding image quality superior to MV imaging for the case of low-density-variability, low-optical-attenuation materials (ex: breast/oropharynx). Ongoing work involves microenvironment functionalization of QDs and application of multi-channel spectrometry for simultaneous acquisition of dosimetric and tumor oxygenation signals.« less

Listeria monocytogenes infection enhances the interaction between rat non-classical MHC-Ib molecule and Ly49 receptors.

PubMed

Shegarfi, Hamid; Kane, Kevin P; Nestvold, Janne

2018-05-01

Murine NK cell Ly49 receptors, functionally analogous to KIRs in humans recognize MHC class I molecules and play a key role in controlling NK cell function. We have previously shown that the paired activating Ly49s4 and inhibitory Ly49i4 receptors recognize undefined non-classical MHC-Ib ligands from the RT1-CE region in rats. Here, the RT1-CE16 gene of the RT1 d haplotype was stably transfected into the mouse RAW macrophage cell line, termed RAW-CE16 d cells. Combining RAW-CE16 d cells with Ly49 expressing reporter cells demonstrated Ly49i4 and Ly49s4 specificity for CE16 d . The Ly49s4/i4:CE16 d interaction was confirmed by specific MHC-I blocking monoclonal Abs. Further, we used our in vitro model to study the effect of Listeria monocytogenes (LM) on CE16 d after infection. LM infection and IFN-γ stimulation both led to enhanced CE16 d expression on the surface of transfected RAW-CE16 d cells. Interestingly, the reporter cells displayed increased response to LM-infected RAW-CE16 d cells compared with IFN-γ-treated RAW-CE16 d cells, suggesting a fundamental difference between these stimuli in supporting enhanced Ly49 recognition of CE16 d . Collectively, our data show that Ly49s4 and Ly49i4 recognize the non-classical RT1-CE16 d molecule, which in turn is up-regulated during LM infection and thereby may contribute to NK-mediated responses against infected cells.

A theoretical insight into the catalytic effect of a mixed-metal oxide at the nanometer level: The case of the highly active metal/CeOx/TiO2(110) catalysts

NASA Astrophysics Data System (ADS)

Graciani, Jesús; Plata, José J.; Sanz, Javier Fdez.; Liu, Ping; Rodriguez, José A.

2010-03-01

The structural and electronic properties of CeOx species supported on the rutile TiO2(110) surface have been examined by means of periodic density-functional calculations that use a generalized gradient approximation functional including a Hubbard-like type correction. Deposition of Ce atoms leads in a first step to Ce3+ ions bound to the surface through bridge and in-plane oxygen atoms, the released electrons occupying the Ti 3d empty orbitals. Further addition of Ce and molecular oxygen gives place to Ce2O3 dimers diagonally arranged on the surface, in agreement with the spots observed in the scanning tunnel microscope images. The formation process of CeOx nanoparticles (NPs) on the TiO2 surface is highly exothermic and our calculations show that the redox properties of the Ce(III)-Ce(IV) couple are significantly altered when it is supported on TiO2. In particular the reactivity against CO/O2 indicates that on the surface the presence of Ce(III) is favored over Ce(IV) species. Our results also indicate that the CeOx/TiO2 interface should be seen like a real mixed-metal oxide rather than a supported NP of ceria. Finally, in the context of the high catalytic activity of the M /CeOx/TiO2 (M =Au,Cu,Pt) systems in the water-gas shift reaction, we have examined the dissociation of water on the CeOx/TiO2 surface and estimated a barrier as small as 0.04 eV, i.e. ˜8 times smaller than that computed for a TiO2 oxygen vacancy. This result agrees with the experimental superior catalytic activity of the M /CeOx/TiO2 systems over M /TiO2.

Effect of CeLa addition on the microstructures and mechanical properties of Al-Cu-Mn-Mg-Fe alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Du, Jiandi

Development of high strength lithium battery shell alloy is highly desired for new energy automobile industry. The microstructures and mechanical properties of Al-Cu-Mn-Mg-Fe alloy with different CeLa additions were investigated through optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Rietveld refinement and tensile testing. Experimental results indicate that Al{sub 8}Cu{sub 4}Ce and Al{sub 6}Cu{sub 6}La phases formed due to CeLa addition. Addition of 0.25 wt.% CeLa could promote the formation of denser precipitation of Al{sub 20}Cu{sub 2}Mn{sub 3} and Al{sub 6}(Mn, Fe) phases, which improved the mechanical properties of the alloy at room temperature.more » However, up to 0.50 wt.% CeLa addition could promote the formation of coarse Al{sub 8}Cu{sub 4}Ce phase, Al{sub 6}Cu{sub 6}La phase and Al{sub 6}(Mn, Fe) phase, which resulted in weakened mechanical properties. - Highlights: •Al-Cu-Mn-Mg-Fe alloys with different CeLa addition were fabricated through casting and rolling. •Al{sub 8}Cu{sub 4}Ce and Al{sub 6}Cu{sub 6}La phases formed after CeLa addition. •Addition of 0.25 wt.% CeLa promoted formation of denser precipitates of Al{sub 20}Cu{sub 2}Mn{sub 3} and Al{sub 6}(Mn, Fe). •Mechanical properties of the alloy was improved after 0.25 wt.% CeLa addition.« less

HIV prevention cost-effectiveness: a systematic review

PubMed Central

2009-01-01

Background After more than 25 years, public health programs have not been able to sufficiently reduce the number of new HIV infections. Over 7,000 people become infected with HIV every day. Lack of convincing evidence of cost-effectiveness (CE) may be one of the reasons why implementation of effective programs is not occurring at sufficient scale. This paper identifies, summarizes and critiques the CE literature related to HIV-prevention interventions in low- and middle-income countries during 2005-2008. Methods Systematic identification of publications was conducted through several methods: electronic databases, internet search of international organizations and major funding/implementing agencies, and journal browsing. Inclusion criteria included: HIV prevention intervention, year for publication (2005-2008), setting (low- and middle-income countries), and CE estimation (empirical or modeling) using outcomes in terms of cost per HIV infection averted and/or cost per disability-adjusted life year (DALY) or quality-adjusted life year (QALY). Results We found 21 distinct studies analyzing the CE of HIV-prevention interventions published in the past four years (2005-2008). Seventeen CE studies analyzed biomedical interventions; only a few dealt with behavioral and environmental/structural interventions. Sixteen studies focused on sub-Saharan Africa, and only a handful on Asia, Latin America and Eastern Europe. Many HIV-prevention interventions are very cost effective in absolute terms (using costs per DALY averted), and also in country-specific relative terms (in cost per DALY measured as percentage of GDP per capita). Conclusion There are several types of interventions for which CE studies are still not available or insufficient, including surveillance, abstinence, school-based education, universal precautions, prevention for positives and most structural interventions. The sparse CE evidence available is not easily comparable; thus, not very useful for decision making. More than 25 years into the AIDS epidemic and billions of dollars of spending later, there is still much work to be done both on costs and effectiveness to adequately inform HIV prevention planning. PMID:19922689

Ceria promoted deoxygenation and denitrogenation of Thalassiosira weissflogii and its model compounds by catalytic in-situ pyrolysis.

PubMed

Aysu, Tevfik; Maroto-Valer, M Mercedes; Sanna, Aimaro

2016-05-01

Pyrolysis of microcrystalline cellulose, egg white powder, palm-jojoba oils mixtures Thalassiosira weissflogii model compounds was performed with CeO2 at 500°C, to evaluate its catalytic upgrading mechanism. Light organics, aromatics and aliphatics were originated from carbohydrates, proteins and lipids, respectively. Dehydration and decarboxylation were the main reactions involved in the algae and model compounds deoxygenation, while nitrogen was removed as NH3 and HCN. CeO2 increased decarbonylation reactions compared to in absence of catalyst, with production of ketones. The results showed that the catalysts had a significant effect on the pyrolysis products composition of T. weissflogii. CeO2, NiCeAl2O3 and MgCe/Al2O3 catalysts increased the aliphatics and decreased the oxygen content in bio-oils to 6-7 wt% of the algae starting O2 content. Ceria catalysts were also able to consistently reduce the N-content in the bio-oil to 20-38% of that in the parent material, with NiCe/Al2O3 being the most effective. Copyright © 2016 Elsevier Ltd. All rights reserved.

Superparamagnetic Fe3O4-PEG2K-FA@Ce6 Nanoprobes for in Vivo Dual-mode Imaging and Targeted Photodynamic Therapy

NASA Astrophysics Data System (ADS)

Yin, Ting; Huang, Peng; Gao, Guo; Shapter, Joseph G.; Shen, Yulan; Sun, Rongjin; Yue, Caixia; Zhang, Chunlei; Liu, Yanlei; Zhou, Sui; Cui, Daxiang

2016-11-01

The development of targeted nanoprobes is a promising approach to cancer diagnostics and therapy. In the present work, a novel multifunctional photo/magnet-diagnostic nanoprobe (MNPs-PEG2K-FA@Ce6) has been developed. This nanoprobe is built using folic acid (FA), bifunctional polyethylene glycol (PEG2K) and photosensitizer chlorin e6 (Ce6). The MNPs-PEG2K-FA@Ce6 nanoprobes are superparamagnetic, can be synthesized on a large scale by a one-pot hydrothermal process without further surface modification and are stable in an aqueous environment for eight months. Compared with free Ce6 nanoprobes in vitro studies, the MNPs-PEG2K-FA@Ce6 nanoprobes significantly enhance cellular uptake efficiency and promote the effectiveness of photodynamic therapy (PDT) with the assistance of 633 nm laser irradiation. The unique nanoprobes show superior penetration and a retention time of more than six days with less accumulation in the liver allowing highly effective tumor recognition and monitoring. Additionally, there was little damage to healthy organs or tissues. These exciting new nanoprobes could be potential building blocks to develop new clinical therapies and translational medicine.

Additive assisted hydrothermal synthesis, characterization and optical properties of one dimensional DyPO4:Ce3+ nanostructures

NASA Astrophysics Data System (ADS)

Khajuria, H.; Kumar, M.; Singh, R.; Ladol, J.; Nawaz Sheikh, H.

2018-05-01

One dimensional nanostructures of cerium doped dysprosium phosphate (DyPO4:Ce3+) were synthesized via hydrothermal route in the presence of different surfactants [sodium dodecyl sulfate (SDS), dodecyl sulfosuccinate (DSS), polyvinyl pyrollidone (PVP)] and solvent [ethylene glycol and water]. The prepared nanostructures were characterized by Powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), UV-VIS-NIR absorption spectrophotometer and photoluminescence (PL) studies. The PXRD and FTIR results indicate purity, good crystallinity and effective doping of Ce3+ in nanostructures. SEM and TEM micrographs display nanorods, nanowires and nanobundles like morphology of DyPO4:Ce3+. Energy-dispersive X-ray spectra (EDS) of DyPO4:Ce3+nanostructures confirm the presence of dopant. UV-VIS-NIR absorption spectra of prepared compounds are used to calculate band gap and explore their optical properties. Luminescent properties of DyPO4:Ce3+ was studied by using PL emission spectra. The effect of additives and solvents on the uniformity, morphology and optical properties of the nanostructures were studied in detail.

Effect of Co doping on structural and mechanical properties of CeO2

NASA Astrophysics Data System (ADS)

Tiwari, Saurabh; Balasubramanian, Nivedha; Biring, Sajal; Sen, Somaditya

2018-05-01

Sol-gel synthesized nanocrystalline Co doped CeO2 powders [(Ce1-xCoxO2; x=0, 0.03)] were made into cylindrical discs by uniaxial pressing and sintered at 1500°C for 24h to measure mechanical properties. The pure phase formation of undoped and Co doped samples were confirmed by X-ray diffraction and Raman analysis. The scanning electron microscopy (SEM) was used for observing the microstructure of sintered samples to investigate density, porosity, and grain size. The grains size observed for 1500°C sintered samples 5-8 µm. Vickers indentation method used for investigating the micro-hardness. For undoped CeO2 micro-hardness was found 6.2 GPa which decreased with Co doping. It was found that samples follow indentation size effect (ISE) and follow elastic than plastic deformation. Enhanced ductile nature with Co doping in CeO2 made it more promising material for optoelectronic device applications.

Reduced Current Spread by Concentric Electrodes in Transcranial Electrical Stimulation (tES).

PubMed

Bortoletto, M; Rodella, C; Salvador, R; Miranda, P C; Miniussi, C

2016-01-01

We propose the use of a new montage for transcranial direct current stimulation (tDCS), called concentric electrodes tDCS (CE-tDCS), involving two concentric round electrodes that may improve stimulation focality. To test efficacy and focality of CE-tDCS, we modelled the current distribution and tested physiological effects on cortical excitability. Motor evoked potentials (MEPs) from first dorsal interosseous (FDI) and abductor digiti minimi (ADM) were recorded before and after the delivery of anodal, cathodal and sham stimulation on the FDI hotspot for 10 minutes. MEP amplitude of FDI increased after anodal-tDCS and decreased after cathodal-tDCS, supporting the efficacy of CE-tDCS in modulating cortical excitability. Moreover, modelled current distribution and no significant effects of stimulation on MEP amplitude of ADM suggest high focality of CE-tDCS. CE-tDCS may allow a better control of current distribution and may represent a novel tool for applying tDCS and other transcranial current stimulation approaches. Copyright © 2016 Elsevier Inc. All rights reserved.

Investigating effects of nano cerium oxide reinforcement on mechanical properties of composite based on natural rubber

NASA Astrophysics Data System (ADS)

Bao, Le Quoc; Phan, Vu Hoang Giang; Khuyen, Nguyen Quang

2018-04-01

Polymer nanocomposites that based on combination of nanomaterials (such as nanoparticles, nanotubes, nanorods, nanofibers, and nanosheets) and polymeric matrices are receiving great attention in research and application. However, separate and homogenous dispersion rather than aggregates of nanoparticles into matrices meet big difficulty due to large interaction between nanoparticles. The poor dispersion leads to low properties of nanocomposites. In this study, we find out the appropriate method to separately disperse cerium oxides (CeO2) nanoparticles into natural rubber, aiming to increase mechanical properties of natural rubber. The SEM images were used to evaluate the dispersion of nano CeO2 in natural rubber matrix. The mechanical properties of nanocomposites were measured after vulcanization to investigate effects of nano CeO2 amount on prepared composite. The findings exhibited that the addition of CeO2 by dispersion of nano CeO2 in water via ultrasonication before mixing with rubber latex, significantly increase modulus, tear and wear resistance of natural rubber.

Recruitment of rural healthcare professionals for live continuing education.

PubMed

Holuby, Ronnie Scott; Pellegrin, Karen L; Barbato, Anna; Ciarleglio, Anita

2015-01-01

Introduction The availability of rural healthcare is a growing concern in the United States as fewer healthcare providers choose to work in rural areas. Accessing quality continuing education (CE) for rural healthcare practitioners (HCPs) remains a challenge and may pose a barrier to quality care. Methods To maximize attendance at a live, in-person, free CE program focusing on geriatric medication and issues specifically targeted to HCPs in rural areas, two methods were implemented sequentially. The first method used formal advertising implemented by a professional marketing service to promote CE events. The second method enlisted local healthcare organizations and physician groups to promote the CE event to their employees. Cost per attendee was calculated for comparison. Results Professional marketing services recruited 31 HCPs (March 2011) and resulted in a per-participant recruitment cost of US$428.62. Local healthcare organizations and physician groups' marketing recruited 48 HCPs (July-August 2011) and resulted in a per-participant recruitment cost of US$55.19. Discussion Providing free CE coordinated through local healthcare organizations and physician groups was the most cost-effective method of recruiting rural HCPs for CE. Formal advertising added cost without increasing the number of participants per event. Although this is the first study of the cost-effectiveness of recruitment methods targeting HCPs in rural areas, results are consistent with research on cost-effectiveness of outreach to rural lay community members.

Effect of Adding Cerium on Microstructure and Morphology of Ce-Based Inclusions Formed in Low-Carbon Steel

PubMed Central

Adabavazeh, Z.; Hwang, W. S.; Su, Y. H.

2017-01-01

Intra-granular Acicular Ferrite (IAF), as one of the most well-known desirable microstructure of ferrite with a chaotic crystallographic orientation, can not only refine the microstructure and retard the propagation of cleavage crack but also provide excellent combination of strength and toughness in steel. The effect of adding cerium on microstructure and controlling proper cerium-based inclusions in order to improve properties in low-carbon commercial steel (SS400) were investigated. The type of inclusions can be controlled by changing S/O ratio and Ce content. Without Ce modification, MnS is a dominate inclusion. After adding Ce, the stable inclusion phases change from AlCeO3 to Ce2O2S. The optimum amount of cerium, 0.0235 wt.%, lead in proper grain refinement and formation of cerium oxide, oxy-sulfide and sulfide inclusions. Having a high amount of cerium results in increasing the number of inclusions significantly as a result it cannot be effective enough and the inclusions will act like barriers for others. It is found that the inclusions with a size of about 4∼7 μm can serve as heterogeneous nucleation sites for AF formation. Thermodynamic calculations have been applied to predict the inclusion formation in this molten steel as well, which show a good agreement with experimental one. PMID:28485376

Recruitment of rural healthcare professionals for live continuing education.

PubMed

Holuby, Ronnie Scott; Pellegrin, Karen L; Barbato, Anna; Ciarleglio, Anita

2015-01-01

The availability of rural healthcare is a growing concern in the United States as fewer healthcare providers choose to work in rural areas. Accessing quality continuing education (CE) for rural healthcare practitioners (HCPs) remains a challenge and may pose a barrier to quality care. To maximize attendance at a live, in-person, free CE program focusing on geriatric medication and issues specifically targeted to HCPs in rural areas, two methods were implemented sequentially. The first method used formal advertising implemented by a professional marketing service to promote CE events. The second method enlisted local healthcare organizations and physician groups to promote the CE event to their employees. Cost per attendee was calculated for comparison. Professional marketing services recruited 31 HCPs (March 2011) and resulted in a per-participant recruitment cost of US$428.62. Local healthcare organizations and physician groups' marketing recruited 48 HCPs (July-August 2011) and resulted in a per-participant recruitment cost of US$55.19. Providing free CE coordinated through local healthcare organizations and physician groups was the most cost-effective method of recruiting rural HCPs for CE. Formal advertising added cost without increasing the number of participants per event. Although this is the first study of the cost-effectiveness of recruitment methods targeting HCPs in rural areas, results are consistent with research on cost-effectiveness of outreach to rural lay community members.

Integrating environmental monitoring with cumulative effects management and decision making.

PubMed

Cronmiller, Joshua G; Noble, Bram F

2018-05-01

Cumulative effects (CE) monitoring is foundational to emerging regional and watershed CE management frameworks, yet monitoring is often poorly integrated with CE management and decision-making processes. The challenges are largely institutional and organizational, more so than scientific or technical. Calls for improved integration of monitoring with CE management and decision making are not new, but there has been limited research on how best to integrate environmental monitoring programs to ensure credible CE science and to deliver results that respond to the more immediate questions and needs of regulatory decision makers. This paper examines options for the integration of environmental monitoring with CE frameworks. Based on semistructured interviews with practitioners, regulators, and other experts in the Lower Athabasca, Alberta, Canada, 3 approaches to monitoring system design are presented. First, a distributed monitoring system, reflecting the current approach in the Lower Athabasca, where monitoring is delegated to different external programs and organizations; second, a 1-window system in which monitoring is undertaken by a single, in-house agency for the purpose of informing management and regulatory decision making; third, an independent system driven primarily by CE science and understanding causal relationships, with knowledge adopted for decision support where relevant to specific management questions. The strengths and limitations of each approach are presented. A hybrid approach may be optimal-an independent, nongovernment, 1-window model for CE science, monitoring, and information delivery-capitalizing on the strengths of distributed, 1-window, and independent monitoring systems while mitigating their weaknesses. If governments are committed to solving CE problems, they must invest in the long-term science needed to do so; at the same time, if science-based monitoring programs are to be sustainable over the long term, they must be responsive to the more immediate, often shorter term needs and CE information requirements of decision makers. Integr Environ Assess Manag 2018;14:407-417. © 2018 SETAC. © 2018 SETAC.

Effects of Zr/Ce molar ratio and water content on thermal stability and structure of ZrO{sub 2}–CeO{sub 2} mixed oxides prepared via sol–gel process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Wenzhi; Yang, Jili; Wang, Chunjie

2012-09-15

Highlights: ► Tetragonal t″ phase was stabilized in Zr{sub 0.5}Ce{sub 0.5}O{sub 2} solid solution at temperature as high as 1000 °C. ► Specific surface area of powders decreased with the increase of water addition and the Ce content. ► The single stable phase was controlled by adjusting the volume ratio of water and ethanol. ► Tetragonal (t″) phase dissociated into cubic and tetragonal (t′) phases at 1200 °C. -- Abstract: ZrO{sub 2}–CeO{sub 2} mixed oxides were synthesized via sol–gel process. Thermal stability, structure and morphology of samples were investigated by powder X-ray diffraction, FT-Raman spectroscopy, X-ray photoelectron spectroscopy and scanningmore » electron microscopy. In this approach, the solvent composition and Zr/Ce molar ratio have great influences on the structure and morphology of final products. With decreasing water content in the mixed solvent, specific surface area of powders increased and the single tetragonal phase was obtained. Only when the volume ratio of water and ethanol and the Zr/Ce molar ratio were 1:1, tetragonal t″-Zr{sub 0.5}Ce{sub 0.5}O{sub 2} could be stabilized in powders at temperature as high as 1000 °C. Meanwhile, tetragonal (t′) and (t″) phases coexisted in Zr{sub 0.5}Ce{sub 0.5}O{sub 2} solid solution without peak splitting after calcination at 1100 °C, further transforming into cubic and tetragonal (t′) phases at 1200 °C. The effective activation energy for Zr{sub 0.5}Ce{sub 0.5}O{sub 2} nanocrystallite growth during annealing is about 5.24 ± 0.15 kJ/mol.« less

Cation-exchange high-performance liquid chromatography for variant hemoglobins and HbF/A2: What must hematopathologists know about methodology?

PubMed

Sharma, Prashant; Das, Reena

2016-03-26

Cation-exchange high-performance liquid chromatography (CE-HPLC) is a widely used laboratory test to detect variant hemoglobins as well as quantify hemoglobins F and A2 for the diagnosis of thalassemia syndromes. It's versatility, speed, reproducibility and convenience have made CE-HPLC the method of choice to initially screen for hemoglobin disorders. Despite its popularity, several methodological aspects of the technology remain obscure to pathologists and this may have consequences in specific situations. This paper discusses the basic principles of the technique, the initial quality control steps and the interpretation of various controls and variables that are available on the instrument output. Subsequent sections are devoted to methodological considerations that arise during reporting of cases. For instance, common problems of misidentified peaks, totals crossing 100%, causes of total area being above or below acceptable limits and the importance of pre-integration region peaks are dealt with. Ultimately, CE-HPLC remains an investigation, the reporting of which combines in-depth knowledge of the biological basics with more than a working knowledge of the technological aspects of the technique.

New CeO2 nanoparticles-based topical formulations for the skin protection against organophosphates.

PubMed

Zenerino, Arnaud; Boutard, Tifenn; Bignon, Cécile; Amigoni, Sonia; Josse, Denis; Devers, Thierry; Guittard, Frédéric

2015-01-01

To reinforce skin protection against organophosphates (OPs), the development of new topical skin protectants (TSP) has received a great interest. Nanoparticles like cerium dioxide (CeO 2 ) known to adsorb and neutralize OPs are interesting candidates for TSP. However, NPs are difficult to disperse into formulations and they are suspected of toxicological issues. Thus, we want to study: (1) the effect of the addition of CeO 2 NPs in formulations for the skin protection (2) the impact of the doping of CeO 2 NPs by calcium; (3) the effect of two methods of dispersion of CeO 2 NPs: an O/W emulsion or a suspension of a fluorinated thickening polymer (HASE-F) grafted with these NPs. As a screening approach we used silicone membranes as a skin equivalent and Franz diffusion cells for permeation tests. The addition of pure CeO 2 NPs in both formulations permits the penetration to decrease by a 3-4-fold factor. The O/W emulsion allows is the best approach to obtain a film-forming coating with a good reproducibility of the penetration results; whereas the grafting of NPs to a thickener is the best way to obtain an efficient homogenous suspension of CeO 2 NPs with a decreased of toxicological impact but the coating is less film-forming which slightly impacts the reproducibility of the penetration results.

Lethality to leukemia cell lines of DNA interstrand cross-links generated by Cloretazine derived alkylating species

PubMed Central

Penketh, Philip G.; Baumann, Raymond P.; Ishiguro, Kimiko; Shyam, Krishnamurthy; Seow, Helen A.; Sartorelli, Alan C.

2010-01-01

Cloretazine [1, 2-bis(methylsulfonyl)-1-(2-chloroethyl)-2-[(methylamino)carbonyl]-hydrazine; VNP40101M; 101M] is a relatively new prodrug with activity in elderly acute myelogenous leukemia patients. Its therapeutic action is due largely to the production of 1-(3-cytosinyl),2-(1-guanyl)ethane cross-links (G-C ethane cross-links) in DNA. The number of cross-links produced in three experimental leukemia lines (L1210, U937 and HL-60) were fewer than 10 per genome at their respective LC50 concentrations. Only 1 in approximately 20,000 90CE molecules produce a cross-link in the AGT (O6-alkylguanine-DNA alkyltransferase) negative L1210 and U937 cell lines and 1 in 400,000 in the AGT positive HL-60 cell line. PMID:18479747

A comparison of nickel-titanium rotary instruments manufactured using different methods and cross-sectional areas: ability to resist cyclic fatigue.

PubMed

Oh, So-Ram; Chang, Seok-Woo; Lee, Yoon; Gu, Yu; Son, Won-Jun; Lee, Woocheol; Baek, Seung-Ho; Bae, Kwang-Shik; Choi, Gi-Woon; Lim, Sang-Min; Kum, Kee-Yeon

2010-04-01

This study examined the effect of the manufacturing methods (ground, electropolished, and twisted) and the cross-sectional area (CSA) of nickel-titanium (NiTi) rotary instruments on their cyclic fatigue resistance. A total of 80 NiTi rotary instruments (ISO 25/.06 taper) from 4 brands (K3, ProFile, RaCe, and TF) were rotated in a simulated root canal with pecking motion until fracture. The number of cycles to failure (NCF) was calculated. The CSA at 3 mm from the tip of new instruments of each brand was calculated. The correlation between the CSA and NCF was evaluated. All fractured surfaces were analyzed using a scanning electron microscope to determine the fracture mode. The TF instruments were the most resistant to fatigue failure. The resistance to cyclic failure increased with decreasing CSA. All fractured surfaces showed the coexistence of ductile and brittle properties. The CSA had a significant effect on the fatigue resistance of NiTi rotary instruments. Copyright 2010 Mosby, Inc. All rights reserved.

A Systematic Review of the Effects of Continuing Education Programs on Providing Clinical Community Pharmacy Services

PubMed Central

Marques dos Reis, Tiago; Guidoni, Camilo Molino; Girotto, Edmarlon; Guerra, Marisabelle Lima; de Oliveira Baldoni, André; Leira Pereira, Leonardo Régis

2016-01-01

Objective. To summarize the effects of media methods used in continuing education (CE) programs on providing clinical community pharmacy services and the methods used to evaluate the effectiveness of these programs. Methods. A systematic review was performed using Medline, SciELO, and Scopus databases. The timeline of the search was 1990 to 2013. Searches were conducted in English, Portuguese, and Spanish. Results. Nineteen articles of 3990 were included. Fourteen studies used only one media method, and the live method (n=11) was the most frequent (alone or in combination). Only two studies found that the CE program was ineffective or partially effective; these studies used only the live method. Most studies used nonrobust, nonvalidated, and nonstandardized methods to measure effectiveness. The majority of studies focused on the effect of the CE program on modifying the knowledge and skills of the pharmacists. One study assessed the CE program’s benefits to patients or clients. Conclusion. No evidence was obtained regarding which media methods are the most effective. Robust and validated methods, as well as assessment standardization, are required to clearly determine whether a particular media method is effective. PMID:27402991

Uptake and accumulation of bulk and nanosized cerium oxide particles and ionic cerium by radish (Raphanus sativus L.).

PubMed

Zhang, Weilan; Ebbs, Stephen D; Musante, Craig; White, Jason C; Gao, Cunmei; Ma, Xingmao

2015-01-21

The potential toxicity and accumulation of engineered nanomaterials (ENMs) in agricultural crops has become an area of great concern and intense investigation. Interestingly, although below-ground vegetables are most likely to accumulate the highest concentrations of ENMs, little work has been done investigating the potential uptake and accumulation of ENMs for this plant group. The overall objective of this study was to evaluate how different forms of cerium (bulk cerium oxide, cerium oxide nanoparticles, and the cerium ion) affected the growth of radish (Raphanus sativus L.) and accumulation of cerium in radish tissues. Ionic cerium (Ce(3+)) had a negative effect on radish growth at 10 mg CeCl3/L, whereas bulk cerium oxide (CeO2) enhanced plant biomass at the same concentration. Treatment with 10 mg/L cerium oxide nanoparticles (CeO2 NPs) had no significant effect on radish growth. Exposure to all forms of cerium resulted in the accumulation of this element in radish tissues, including the edible storage root. However, the accumulation patterns and their effect on plant growth and physiological processes varied with the characteristics of cerium. This study provides a critical frame of reference on the effects of CeO2 NPs versus their bulk and ionic counterparts on radish growth.

Facile synthesis of ferromagnetic Ni doped CeO2 nanoparticles with enhanced anticancer activity

NASA Astrophysics Data System (ADS)

Abbas, Fazal; Jan, Tariq; Iqbal, Javed; Ahmad, Ishaq; Naqvi, M. Sajjad H.; Malik, Maaza

2015-12-01

NixCe1-xO2 (where x = 0, 0.01, 0.03, 0.05 and 0.07) nanoparticles were synthesized by soft chemical method and were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman, UV-vis absorption spectroscopy and vibrating sample magnetometer (VSM). XRD and Raman results indicated the formation of single phase cubic fluorite structure for the synthesized nanoparticles. Ni dopant induced excessive structural changes such as decrease in crystallite size as well as lattice constants and enhancement in oxygen vacancies in CeO2 crystal structure. These structural variations significantly influenced the optical and magnetic properties of CeO2 nanoparticles. The synthesized NixCe1-xO2 nanoparticles exhibited room temperature ferromagnetic behavior. Ni doping induced effects on the cytotoxicity of CeO2 nanoparticles were examined against HEK-293 healthy cell line and SH-SY5Y neuroblastoma cancer cell line. The prepared NixCe1-xO2 nanoparticles demonstrated differential cytotoxicity. Furthermore, anticancer activity of CeO2 nanoparticles observed to be significantly enhanced with Ni doping which was found to be strongly correlated with the level of reactive oxygen species (ROS) production. The prepared ferromagnetic NixCe1-xO2 nanoparticles with differential cytotoxic nature may be potential for future targeted cancer therapy.

Monitoring the environmental effects of CeO2 and ZnO nanoparticles through the life cycle of corn (Zea mays) plants and in situ μ-XRF mapping of nutrients in kernels.

PubMed

Zhao, Lijuan; Sun, Youping; Hernandez-Viezcas, Jose A; Hong, Jie; Majumdar, Sanghamitra; Niu, Genhua; Duarte-Gardea, Maria; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

2015-03-03

Information about changes in physiological and agronomic parameters through the life cycle of plants exposed to engineered nanoparticles (NPs) is scarce. In this study, corn (Zea mays) plants were cultivated to full maturity in soil amended with either nCeO2 or nZnO at 0, 400, and 800 mg/kg. Gas exchange was monitored every 10 days, and at harvest, bioaccumulation of Ce and Zn in tissues was determined by ICP-OES/MS. The effects of NPs exposure on nutrient concentration and distribution in ears were also evaluated by ICP-OES and μ-XRF. Results showed that nCeO2 at both concentrations did not impact gas exchange in leaves at any growth stage, while nZnO at 800 mg/kg reduced net photosynthesis by 12%, stomatal conductance by 15%, and relative chlorophyll content by 10% at day 20. Yield was reduced by 38% with nCeO2 and by 49% with nZnO. Importantly, μ-XRF mapping showed that nCeO2 changed the allocation of calcium in kernels, compared to controls. In nCeO2 treated plants, Cu, K, Mn, and Zn were mainly localized at the insertion of kernels into cobs, but Ca and Fe were distributed in other parts of the kernels. Results showed that nCeO2 and nZnO reduced corn yield and altered quality of corn.

The CE marking in the dimension stone sector: difficulties, contradictions, possible solutions

NASA Astrophysics Data System (ADS)

Primavori, Piero

2017-04-01

In accordance with the requirements of the CPR 305/11, no stone products (covered by harmonized standards) can be introduced in the EU market, irrespective of their country of origin, unless they are supported with a Declaration of Performance (DoP) and CE certificate (= CE Marking). The CE marking became compulsory for all stone and marble products as early as 2003, under the legal framework of the CPD 89/106/CE, the EU Directive which, on July 1st, 2013, has been officially replaced by the CPR 305/11. The CE Marking of construction products has been described as one of the most significant change being faced by the construction industry for a decade. Nevertheless, after thirteen years from the introduction of the first products standard, serious difficulties for the CE Marking application still exist. The aim of this contribution is to draw the attention on the effective meaningfulness, applicability and reliability of the CE Marking, on the related aspects for the economic operators (manufacturers, authorized representatives, importers, distributors etc.) and, most of all, for the customers. The following topics and issues are dealt with: - Criteria of the mandatory tests; - Criteria for testing procedures (meaningfulness/reliability/frequency of the TT); - Non-applicability of the testing methods in particular circumstances; - Economic aspects for the companies; - Interpretation of the FPC philosophy; - Formulation of the finished products standards; - Traceability criteria of the stone material; - Threshold-values for the acceptance of a stone material; - Guarantees for the manufacturers and for the customers; - Effective precision and reliability of the DoP and related consequences for manufacturers and customers.

Preparation and Characterization of Graphite Waste/CeO2 Composites

NASA Astrophysics Data System (ADS)

Kusrini, E.; Utami, C. S.; Nasruddin; Prasetyanto, E. A.; Bawono, Aji A.

2018-03-01

In this research, the chemical modification of graphite waste with CeO2 was developed and characterized. Graphite waste was pretreated with mechanical to obtain the size 200 mesh (75 μm), and thermal methods at 110°C oven for 6 hours. Here, we demonstrate final properties of graphite before modification (GBM), activated graphite (GA) and graphite/CeO2 composite with variation of 0.5, 1 and 2 g of CeO2 (G0.5; G1; G2). The effect of CeO2 concentration was observed. The presence of cerium in modified graphite samples (G0.5; G1; G2) were analyzed using SEM-EDX. The results show that the best surface area was found in G2 is 26.82 m2/g. The presence of CeO2 onto graphite surface does not significantly increase the surface area of composites.

On what basis are medical cost-effectiveness thresholds set? Clashing opinions and an absence of data: a systematic review.

PubMed

Cameron, David; Ubels, Jasper; Norström, Fredrik

2018-01-01

The amount a government should be willing to invest in adopting new medical treatments has long been under debate. With many countries using formal cost-effectiveness (C/E) thresholds when examining potential new treatments and ever-growing medical costs, accurately setting the level of a C/E threshold can be essential for an efficient healthcare system. The aim of this systematic review is to describe the prominent approaches to setting a C/E threshold, compile available national-level C/E threshold data and willingness-to-pay (WTP) data, and to discern whether associations exist between these values, gross domestic product (GDP) and health-adjusted life expectancy (HALE). This review further examines current obstacles faced with the presently available data. A systematic review was performed to collect articles which have studied national C/E thresholds and willingness-to-pay (WTP) per quality-adjusted life year (QALY) in the general population. Associations between GDP, HALE, WTP, and C/E thresholds were analyzed with correlations. Seventeen countries were identified from nine unique sources to have formal C/E thresholds within our inclusion criteria. Thirteen countries from nine sources were identified to have WTP per QALY data within our inclusion criteria. Two possible associations were identified: C/E thresholds with HALE (quadratic correlation of 0.63), and C/E thresholds with GDP per capita (polynomial correlation of 0.84). However, these results are based on few observations and therefore firm conclusions cannot be made. Most national C/E thresholds identified in our review fall within the WHO's recommended range of one-to-three times GDP per capita. However, the quality and quantity of data available regarding national average WTP per QALY, opportunity costs, and C/E thresholds is poor in comparison to the importance of adequate investment in healthcare. There exists an obvious risk that countries might either over- or underinvest in healthcare if they base their decision-making process on erroneous presumptions or non-evidence-based methodologies. The commonly referred to value of 100,000$ USD per QALY may potentially have some basis.

On what basis are medical cost-effectiveness thresholds set? Clashing opinions and an absence of data: a systematic review

PubMed Central

Cameron, David; Ubels, Jasper; Norström, Fredrik

2018-01-01

ABSTRACT Background: The amount a government should be willing to invest in adopting new medical treatments has long been under debate. With many countries using formal cost-effectiveness (C/E) thresholds when examining potential new treatments and ever-growing medical costs, accurately setting the level of a C/E threshold can be essential for an efficient healthcare system. Objectives: The aim of this systematic review is to describe the prominent approaches to setting a C/E threshold, compile available national-level C/E threshold data and willingness-to-pay (WTP) data, and to discern whether associations exist between these values, gross domestic product (GDP) and health-adjusted life expectancy (HALE). This review further examines current obstacles faced with the presently available data. Methods: A systematic review was performed to collect articles which have studied national C/E thresholds and willingness-to-pay (WTP) per quality-adjusted life year (QALY) in the general population. Associations between GDP, HALE, WTP, and C/E thresholds were analyzed with correlations. Results: Seventeen countries were identified from nine unique sources to have formal C/E thresholds within our inclusion criteria. Thirteen countries from nine sources were identified to have WTP per QALY data within our inclusion criteria. Two possible associations were identified: C/E thresholds with HALE (quadratic correlation of 0.63), and C/E thresholds with GDP per capita (polynomial correlation of 0.84). However, these results are based on few observations and therefore firm conclusions cannot be made. Conclusions: Most national C/E thresholds identified in our review fall within the WHO’s recommended range of one-to-three times GDP per capita. However, the quality and quantity of data available regarding national average WTP per QALY, opportunity costs, and C/E thresholds is poor in comparison to the importance of adequate investment in healthcare. There exists an obvious risk that countries might either over- or underinvest in healthcare if they base their decision-making process on erroneous presumptions or non-evidence-based methodologies. The commonly referred to value of 100,000$ USD per QALY may potentially have some basis. PMID:29564962

Knowledge, attitudes and practices related to cystic echinococcosis endemicity in Pakistan.

PubMed

Khan, Aisha; Naz, Kashf; Ahmed, Haroon; Simsek, Sami; Afzal, Muhammad Sohail; Haider, Waseem; Ahmad, Sheikh Saeed; Farrakh, Sumaira; Weiping, Wu; Yayi, Guan

2018-01-22

Cystic echinococcosis (CE) is a human and animal health problem in many endemic areas worldwide. It is considered a neglected zoonotic disease caused by the larval form (hydatid cyst) of Echinococcus spp. tapeworm. There are limited studies on echinococcosis in Pakistan. A cross-sectional survey was conducted to find out recent knowledge, attitudes and practices on the occurrence of cystic echinococcosis in butchers and dog owners in both urban and rural areas of Rawalpindi/Islamabad regions, Pakistan. The quantitative data was collected in the form of questionnaires to investigate the knowledge and awareness of CE among community members and their routine practices that  were behind the factors involved in hydatid cyst infection. The practices and infrastructure of abattoirs/butcher shops and their role in transmission of cystic echinococcosis were also evaluated in the present study. The participants involved in the study were dog owners and people who kept animals. A total of 400 people were interviewed and 289 questionnaires were received. The results showed that only 4.1% of people have heard about the disease, and 58.1% were closely associated with dogs. Sixty-three percent of dogs in study area were consuming uncooked organs (e.g. liver, lung, etc.) of slaughtered animals, while 100% of dogs at butcher shops were consuming uncooked organs. Home slaughtering was common in 20.06%. Among butchers, 32.3% had heard about zoonoses and 7.61% knew about CE. The statistical analysis showed that there was highly significant difference (P < 0.05) among most of the practices that were associated with the prevalence of CE. It  was concluded from the present study that, the knowledge and awareness of CE among people of Rawalpindi/Islamabad were low. Because of dogs and poor knowledge of CE among community members and butchers, the transmission of echinococcosis is facilitated. Therefore, there is urgent need to strengthen awareness and health education among people, as well as proper practices related to the CE not only in the study area, but also in other areas of Pakistan.

The effect of target-controlled infusion of low-dose ketamine on heat pain and temporal summation threshold.

PubMed

Lee, Joon-Ho; Cho, Sung-Hwan; Kim, Sang-Hyun; Chae, Won-Soek; Jin, Hee-Cheol; Lee, Jeong-Seok; Kim, Yong-Ik

2011-08-01

We investigated the heat pain threshold (HPT) and temporal summation threshold (TST) before and after target-controlled infusion (TCI) of ketamine with an effect-site concentration (Ce) of 30 and 60 ng/ml. Healthy young volunteers (n = 20) were enrolled. A thermode was applied to the volar side of each volunteer's right forearm, and HPT and TST were measured before and after TCI of ketamine. Vital signs and psychedelic effects according to ketamine infusion were also observed before and after TCI of ketamine. Mean HPT after TCI of ketamine with a Ce of 30 and 60 ng/ml did not increase significantly. However, mean TST after TCI of ketamine with a Ce of 30 and 60 ng/ml increased significantly, in a dose-dependent fashion, compared with the value before ketamine TCI. Vital signs showed no significant difference before and after ketamine TCI. The visual analog scale score of psychedelic symptoms was higher with a Ce of 60 ng/ml than with 30 ng/ml. TCI of ketamine with a Ce of 30 and 60 ng/ml increased TST but not HPT.

Evidence of the differential biotransformation and genotoxicity of ZnO and CeO2 nanoparticles on soybean (Glycine max) plants.

PubMed

López-Moreno, Martha L; de la Rosa, Guadalupe; Hernández-Viezcas, José A; Castillo-Michel, Hiram; Botez, Cristian E; Peralta-Videa, José R; Gardea-Torresdey, Jorge L

2010-10-01

Concern and interest related to the effects of nanomaterials on living organisms are growing in both the scientific and public communities. Reports have described the toxicity of nanoparticles (NPs) on micro- and macro-organisms, including some plant species. Nevertheless, to the authors' knowledge there are no reports on the biotransformation of NPs by edible terrestrial plants. Here, shown for the first time, is evidence pertaining to the biotransformation of ZnO and CeO(2) NPs in plant seedlings. Although the NPs did not affect soybean germination, they produced a differential effect on plant growth and element uptake. By using synchrotron X-ray absorption spectroscopy we obtained clear evidence of the presence of CeO(2) NPs in roots, whereas ZnO NPs were not present. Random amplified polymorphic DNA assay was applied to detect DNA damage and mutations caused by NPs. Results obtained from the exposure of soybean plants to CeO(2) NPs show the appearance of four new bands at 2000 mg L(-1) and three new bands at 4000 mg L(-1) treatment. In this study we demonstrated genotoxic effects from the exposure of soybean plants to CeO(2) NPs.

Effect of cellooligosaccharide or synbiotic feeding on growth performance, fecal condition and hormone concentrations in Holstein calves.

PubMed

Hasunuma, Toshiya; Kawashima, Kenji; Nakayama, Hirofumi; Murakami, Toshiaki; Kanagawa, Hiroyuki; Ishii, Takashige; Akiyama, Kiyoshi; Yasuda, Kenji; Terada, Fuminori; Kushibiki, Shiro

2011-08-01

We investigated the effect of cellooligosaccharide (CE) or a combination of dextran and Lactobacillus casei ssp. casei strain JCM1134(T) (synbiotic; SB) feeding on growth performance, fecal condition and hormone concentrations in Holstein calves. Fifty-two female Holstein calves were randomly assigned to three treatment groups: CE feeding group (n = 16), SB feeding group (n = 18), and control group (n = 18). Body weight at 90 days of age, as well as daily body weight gain (DG) and feed efficiency after weaning to 90 days of age were greater (P < 0.05) in the CE feeding group than in the control group. The total fecal score tended to be lower (P < 0.1) in the SB feeding group than in the control group. Plasma insulin concentration was higher (P < 0.05) in the CE feeding group than in the control group at 90 days of age. Our results indicate that CE feeding improved DG and feed efficiency in calves. On the other hand, there was less effect on growth performance and fecal Escherichia coli counts in calves fed SB. 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.

The relationship between the target effective site concentration of rocuronium and the degree of recovery from neuromuscular blockade in elderly patients

PubMed Central

Fan, Xiaochong; Ma, Minyu; Li, Zhisong; Gong, Shengkai; Zhang, Wei; Wen, Yuanyuan

2015-01-01

Objective: To study the relationship between the target effective site concentration (Ce) of rocuronium and the degree of recovery from neuromuscular blockade in elderly patients. Methods: 50 elderly patients (ASA grade II) scheduled for selective surgical procedure under general anaesthesia were randomly divided into two groups, A and B, with 25 cases in each group. The Ce of rocuronium for intubation was 3 μg·ml-1 in both groups, and the Ce during operation were 0.8 and 1.0 μg·ml-1 in group A and B, respectively. When target controlled infusion of rocuronium was stopped, without the administration of reversal agents for neuromuscular blockade, the relationship between Ce and the first twitch height (T1) was studied by regression analysis. Results: There was a significant linear relationship between Ce and T1, and there was no statistical difference in regression coefficient and interception between group A and B (P>0.05). Conclusion: The degree of recovery from neuromuscular blockade could be judged by the target effective site concentration of rocuronium at the time of reversal from neuromuscular blockade in the elderly patients. PMID:26629159

[Catalytic performance of Ce/Zr series catalysts on soot combustion].

PubMed

Zhu, Ling; Wang, Xue-Zhong; Hao, Zheng-Ping

2005-09-01

Catalytic performances of Ce/Zr series catalysts (Ce(x)Zr(1-x)O2) on soot combustion and the influence of feed gas were investigated by TG and TPO. The catalytic activity is high, and affects by the Ce/Zr ratio. The concentration of O2 affects the speed-limited step during the process of soot combustion. H2O showed no effect on the catalytic activity for soot combustion on Ce(0.5)Zr(0.5)O2. NO could promote soot combustion by presenting NO2, a more powerful oxidant than O2, and the ignition temperature of soot decreased 30 degrees C. Results of TG and TPO show that the beta species oxygen on the catalyst take part in the combustion process.

Cerium enhances germination and shoot growth, and alters mineral nutrient concentration in rice

PubMed Central

García-Morales, Soledad; Pérez-Sato, Juan Antonio

2018-01-01

Cerium (Ce) belongs to the rare earth elements (REEs), and although it is not essential for plants, it can stimulate growth and other physiological processes. The objective of this research was to evaluate the effect of Ce on seed germination, initial seedling growth, and vegetative growth in rice (Oryza sativa L.) cv. Morelos A-98. During the germination process, the seeds were treated with Ce concentrations of 0, 4, 8, and 12 μM; after 5 d, germination percentage was recorded and after 10 d seedling growth was measured. For vegetative growth, a hydroponic system was established where 14-d-old plants without previous Ce treatment were transferred into nutrient solution. After two weeks of acclimatizing, 0, 25, 50, and 100 μM Ce were added to the nutrient solution for 28 d. Ce significantly increased germination and the initial growth variables of the seedlings. During vegetative growth, Ce increased plant height, number of tillers, root volume, and shoot fresh and dry biomass, without affecting root biomass weight. With low Ce concentrations (25 and 50 μM), the concentrations of chlorophylls and amino acids in the shoots were similar to those in the control, like amino acid concentration in the roots at a concentration of 25 μM Ce. Conversely, the concentration of total sugars increased in the shoot with the application of 25, 50, and 100 μM Ce, and in the roots with the application of 50 μM Ce. Also, Ce did not affect the concentration of macro or micronutrients in the shoots. However, in the roots, the high Ce concentration decreased the concentrations of Ca, Fe, Mn, and Zn, while the Mg concentration increased. Our results indicate that Ce, at the right concentrations, can function as a biostimulant in rice germination and growth. PMID:29579100

Rare earth elements (REEs): effects on germination and growth of selected crop and native plant species.

PubMed

Thomas, Philippe J; Carpenter, David; Boutin, Céline; Allison, Jane E

2014-02-01

The phytotoxicity of rare earth elements (REEs) is still poorly understood. The exposure-response relationships of three native Canadian plant species (common milkweed, Asclepias syriaca L., showy ticktrefoil, Desmodium canadense (L.) DC. and switchgrass, Panicum virgatum L.) and two commonly used crop species (radish, Raphanus sativus L., and tomato, Solanum lycopersicum L.) to the REEs lanthanum (La), yttrium (Y) and cerium (Ce) were tested. In separate experiments, seven to eight doses of each element were added to the soil prior to sowing seeds. Effects of REE dose on germination were established through measures of total percent germination and speed of germination; effects on growth were established through determination of above ground biomass. Ce was also tested at two pH levels and plant tissue analysis was conducted on pooled samples. Effects on germination were mostly observed with Ce at low pH. However, effects on growth were more pronounced, with detectable inhibition concentrations causing 10% and 25% reductions in biomass for the two native forb species (A. syriaca and D. canadense) with all REEs and on all species tested with Ce in both soil pH treatments. Concentration of Ce in aboveground biomass was lower than root Ce content, and followed the dose-response trend. From values measured in natural soils around the world, our results continue to support the notion that REEs are of limited toxicity and not considered extremely hazardous to the environment. However, in areas where REE contamination is likely, the slow accumulation of these elements in the environment could become problematic. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

On the Cutting Edge Professional Development Program - An effective model built from years of experience

NASA Astrophysics Data System (ADS)

Bruckner, M. Z.; Macdonald, H.; Beane, R. J.; Manduca, C. A.; Mcconnell, D. A.; Mogk, D. W.; Tewksbury, B. J.; Wiese, K.; Wysession, M. E.; Iverson, E. A. R.; Fox, S.

2015-12-01

The On the Cutting Edge (CE) program offers a successful model for designing and convening professional development events. Information about the model is now available on the CE website. The program model has evolved from more than 12 years of experience, building with input from strong leaders and participants. CE offers face-to-face, virtual, and hybrid events, and features a rich website that supports these professional development events as well as a growing community with a shared interest in effective geoscience teaching. Data from national surveys, participant feedback, and self-report data indicate the program's success in improving undergraduate geoscience education. Successes are also demonstrated in classroom observations using RTOP, indicating a significant difference in teaching style among participants and non-participants. A suite of web pages, with a planning timeline, provides guidance to those interested in designing and convening face-to-face or virtual events based on the CE model. The pages suggest ways to develop robust event goals and evaluation tools, how to choose strong leaders and recruit diverse participants, advice for designing effective event programs that utilize participant expertise, websites, and web tools, and suggestions for effectively disseminating event results and producing useful products. The CE model has been successfully transferred to projects that vary in scale and discipline. Best practices from the CE model include (1) thinking of the workshop as shared enterprise among conveners and participants; (2) incorporating conveners and participants who bring diverse viewpoints and approaches; (3) promoting structured discussions that utilize participants' expertise; (4) emphasizing practical strategies to effect change; and (5) using the website as a platform to prepare for the workshop, share ideas, and problem-solve challenges. Learn more about how to utilize this model for your project at:serc.carleton.edu/NAGTWorkshops/workshops/convene

Selective hydrogenation of amides to alcohols in water solvent over a heterogeneous CeO2-supported Ru catalyst.

PubMed

Tamura, Masazumi; Ishikawa, Susumu; Betchaku, Mii; Nakagawa, Yoshinao; Tomishige, Keiichi

2018-06-20

CeO2-supported Ru (Ru/CeO2) worked as an effective and reusable heterogeneous catalyst for the selective dissociation of the C-N bond in amides, particularly primary amides, with H2 in water solvent at low reaction temperature of 333 K, and high yields of the corresponding alcohols were obtained from primary amides.

Contrast-enhanced ultrasound in monitoring the efficacy of a bradykinin receptor 2 antagonist in painful knee osteoarthritis compared with MRI.

PubMed

Song, I H; Althoff, C E; Hermann, K G; Scheel, A K; Knetsch, T; Burmester, G R; Backhaus, M

2009-01-01

To evaluate contrast-enhanced ultrasound (CE-US) as a monitoring tool to assess hypervascularisation of synovial processes in knee osteoarthritis (OA) treated with intra-articular injections of the bradykinin-receptor 2 antagonist icatibant compared to contrast-enhanced magnetic resonance imaging (CE-MRI). In a randomised, double-blind, placebo-controlled trial, 41 patients with painful knee OA underwent US (12.5 MHz for B-mode and 3-8 MHz for CE-US), and 36 of the patients underwent additional MRI (0.2T) at baseline and after 3 injections of the study drug (after a mean of 22.2 days). A total of 15 patients received placebo (group A), 12 patients 500 microg icatibant (group B) and 14 patients 2000 microg icatibant (group C). Pain and the synovial process (B-mode, power Doppler US (PD-US), CE-US, CE-MRI) were assessed at both time points. At baseline, the placebo group showed more activity in terms of effusion in the superior and lateral recess in ultrasound as well as in PD-US in the lateral recess. Pain improved significantly in all subgroups. Effect sizes were 0.43 (pain at rest) and 0.52 (pain during activity) in group B vs 0.48 and 1.11 in group C. There was no change of US and MRI parameters. We found moderate to good correlation (r) and kappa values (kappa) for effusion in the superior recess (r = 0.591, k = 0.453), effusion in the lateral recess (r = 0.304, k = 0.440) and contrast enhancement (r = 0.601, k = 0.242) between US and MRI. Our results show that CE-US and CE-MRI have good agreement in assessing inflammatory changes in knee OA. For the 41 patients with OA, an analgesic effect of icatibant could clearly be shown, especially for pain during activity in the high dose icatibant group. However, we could not find an anti-inflammatory effect of icatibant by CE-US compared to CE-MRI.

Cystic echinococcosis amongst small ruminants and humans in central Ethiopia.

PubMed

Assefa, Habtamu; Mulate, Belay; Nazir, Shahid; Alemayehu, Alula

2015-08-21

This study was conducted to determine the prevalence of cystic echinococcosis (CE) in small ruminants and humans in Addis Ababa, central Ethiopia. A cross-sectional study involving systematic random sampling was conducted to estimate the prevalence of CE in 512 small ruminants (262 sheep and 250 goats) slaughtered at Addis Ababa Abattoir Enterprise between October 2011 and March 2012. Hydatid cysts were identified macroscopically during postmortem examination and their fertility and viability were determined. CE was observed in 21 (8.02%) sheep and 17 (6.80%) goats. In sheep 13 (4.96%) of the lungs, 10 (3.81%) livers and 1 (0.381%) heart were found to be infected with hydatid cysts. Involvement of lung and liver in goats was found to be 10 (4.0%) and 8 (3.2%) respectively, with no cysts recorded in the heart. Of the total of 77 and 47 cysts encountered in sheep and goats, 33 (42.85%) and 15 (31.91%) respectively were fertile. Viability of protoscoleces from fertile cysts in sheep (29 [87.87%]) was higher than in goats (6 [40.0%]). For humans, retrospective analysis covering five years of case reports at two major hospitals in Addis Ababa between January 2008 and December 2012 showed that of the total of 25 840 patients admitted for ultrasound examination, 27 CE cases were registered, a prevalence of 0.1% and mean annual incidence rate of approximately 0.18 cases per 100 000 population. Liver was the major organ affected in humans (81.5% in affected patients) followed by spleen (11.1%) and kidney (7.4%). Logistic regression analysis showed that prevalence of CE varied significantly in relation to host age in the small ruminants (OR = 3.93, P < 0.05) as well as in humans (95% CI, R = 4.8). This epidemiological study confirms the importance of CE in small ruminants and humans in central Ethiopia, emphasising the need for integrated approaches to controlling this neglected preventable disease.

DOI Determination by Rise Time Discrimination in Single-Ended Readout for TOF PET Imaging

PubMed Central

Wiener, R.I.; Surti, S.; Karp, J.S.

2013-01-01

Clinical TOF PET systems achieve detection efficiency using thick crystals, typically of thickness 2–3cm. The resulting dispersion in interaction depths degrades spatial resolution for increasing radial positions due to parallax error. Furthermore, interaction depth dispersion results in time pickoff dispersion and thus in degraded timing resolution, and is therefore of added concern in TOF scanners. Using fast signal digitization, we characterize the timing performance, pulse shape and light output of LaBr3:Ce, CeBr3 and LYSO. Coincidence timing resolution is shown to degrade by ~50ps/cm for scintillator pixels of constant cross section and increasing length. By controlling irradiation depth in a scintillator pixel, we show that DOI-dependence of time pickoff is a significant factor in the loss of timing performance in thick detectors. Using the correlated DOI-dependence of time pickoff and charge collection, we apply a charge-based correction to the time pickoff, obtaining improved coincidence timing resolution of <200ps for a uniform 4×4×30mm3 LaBr3 pixel. In order to obtain both DOI identification and improved timing resolution, we design a two layer LaBr3[5%Ce]/LaBr3[30%Ce] detector of total size 4×4×30mm3, exploiting the dependence of scintillator rise time on [Ce] in LaBr3:Ce. Using signal rise time to determine interaction layer, excellent interaction layer discrimination is achieved, while maintaining coincidence timing resolution of <250ps and energy resolution <7% using a R4998 PMT. Excellent layer separation and timing performance is measured with several other commercially-available TOF photodetectors, demonstrating the practicality of this design. These results indicate the feasibility of rise time discrimination as a technique for measuring event DOI while maintaining sensitivity, timing and energy performance, in a well-known detector architecture. PMID:24403611

DOI Determination by Rise Time Discrimination in Single-Ended Readout for TOF PET Imaging.

PubMed

Wiener, R I; Surti, S; Karp, J S

2013-06-01

Clinical TOF PET systems achieve detection efficiency using thick crystals, typically of thickness 2-3cm. The resulting dispersion in interaction depths degrades spatial resolution for increasing radial positions due to parallax error. Furthermore, interaction depth dispersion results in time pickoff dispersion and thus in degraded timing resolution, and is therefore of added concern in TOF scanners. Using fast signal digitization, we characterize the timing performance, pulse shape and light output of LaBr 3 :Ce, CeBr 3 and LYSO. Coincidence timing resolution is shown to degrade by ~50ps/cm for scintillator pixels of constant cross section and increasing length. By controlling irradiation depth in a scintillator pixel, we show that DOI-dependence of time pickoff is a significant factor in the loss of timing performance in thick detectors. Using the correlated DOI-dependence of time pickoff and charge collection, we apply a charge-based correction to the time pickoff, obtaining improved coincidence timing resolution of <200ps for a uniform 4×4×30mm 3 LaBr 3 pixel. In order to obtain both DOI identification and improved timing resolution, we design a two layer LaBr 3 [5%Ce]/LaBr 3 [30%Ce] detector of total size 4×4×30mm 3 , exploiting the dependence of scintillator rise time on [Ce] in LaBr 3 :Ce. Using signal rise time to determine interaction layer, excellent interaction layer discrimination is achieved, while maintaining coincidence timing resolution of <250ps and energy resolution <7% using a R4998 PMT. Excellent layer separation and timing performance is measured with several other commercially-available TOF photodetectors, demonstrating the practicality of this design. These results indicate the feasibility of rise time discrimination as a technique for measuring event DOI while maintaining sensitivity, timing and energy performance, in a well-known detector architecture.

A reconstruction of sea surface temperature variability in the southeastern Gulf of Mexico from 1734 to 2008 C.E. using cross-dated Sr/Ca records from the coral Siderastrea siderea

NASA Astrophysics Data System (ADS)

DeLong, Kristine L.; Flannery, Jennifer A.; Poore, Richard Z.; Quinn, Terrence M.; Maupin, Christopher R.; Lin, Ke; Shen, Chuan-Chou

2014-05-01

This study uses skeletal variations in coral Sr/Ca from three Siderastrea siderea coral colonies within the Dry Tortugas National Park in the southeastern Gulf of Mexico (24°42'N, 82°48'W) to reconstruct monthly sea surface temperature (SST) variations from 1734 to 2008 Common Era (C.E.). Calibration and verification of the replicated coral Sr/Ca-SST reconstruction with local, regional, and historical temperature records reveals that this proxy-temperature relationship is stable back to 1879 C.E. The coral SST reconstruction contains robust interannual ( 2.0°C) and multidecadal variability ( 1.5°C) for the past 274 years, the latter of which does not covary with the Atlantic Multidecadal Oscillation. Winter SST extremes are more variable than summer SST extremes (±2.2°C versus ±1.6°C, 2σ) suggesting that Loop Current transport in the winter dominates variability on interannual and longer time scales. Summer SST maxima are increasing (+1.0°C for 274 years, σMC = ±0.5°C, 2σ), whereas winter SST minima contain no significant trend. Colder decades ( 1.5°C) during the Little Ice Age (LIA) do not coincide with decades of sunspot minima. The coral SST reconstruction contains similar variability to temperature reconstructions from the northern Gulf of Mexico (planktic foraminifer Mg/Ca) and the Caribbean Sea (coral Sr/Ca) suggesting areal reductions in the Western Hemisphere Warm Pool during the LIA. Mean summer coral SST extremes post-1985 C.E. (29.9°C) exceeds the long-term summer average (29.2°C for 1734-2008 C.E.), yet the warming trend after 1985 C.E. (0.04°C for 24 years, σMC = ±0.5, 2σ) is not significant, whereas Caribbean coral Sr/Ca studies contain a warming trend for this interval.

A facile synthesis of high quality nanostructured CeO2 and Gd2O3-doped CeO2 solid electrolytes for improved electrochemical performance.

PubMed

Kuo, Yu-Lin; Su, Yu-Ming; Chou, Hung-Lung

2015-06-07

This study describes the use of a composite nitrate salt solution as a precursor to synthesize CeO2 and Gd2O3-doped CeO2 (GDC) nanoparticles (NPs) using an atmospheric pressure plasma jet (APPJ). The microstructures of CeO2 and GDC NPs were found to be cubical and spherical shaped nanocrystallites with average particle sizes of 10.5 and 6.7 nm, respectively. Reactive oxygen species, detected by optical emission spectroscopy (OES), are believed to be the major oxidative agents for the formation of oxide materials in the APPJ process. Based on the material characterization and OES observations, the study effectively demonstrated the feasibility of preparing well-crystallized GDC NPs by the APPJ system as well as the gas-to-particle mechanism. Notably, the Bader charge of CeO2 and Ce0.9Gd0.1O2 characterized by density function theory (DFT) simulation and AC impedance measurements shows that Gd helps in increasing the charge on Ce0.9Gd0.1O2 NPs, thus improving their conductivity and making them candidate materials for electrolytes in solid oxide fuel cells.

Growth, Crystal Structure and Magnetic Characterization of Zn-Stabilized CePtIn4

NASA Astrophysics Data System (ADS)

Carnicom, Elizabeth M.; Klimczuk, Tomasz; von Rohr, Fabian; Winiarski, Michal J.; Kong, Tai; Stolze, Karoline; Xie, Weiwei; Kushwaha, Satya K.; Cava, Robert J.

2017-08-01

The growth and characterization of CePtIn4, stabilized by 10% Zn substitution for In, is reported. The new material is orthorhombic, space group Cmcm (No. 63), with lattice parameters a = 4.51751(4) Å, b = 16.7570(2) Å, and c = 7.36682(8) Å, and the refined crystal composition has 10% of Zn substituted for In, i.e., the crystals are CePt(In0.9Zn0.1)4. Crystals were grown using a self-flux method: only growths containing Zn yielded CePtIn4 crystals, while Ce3Pt4In13 crystals formed when Zn was not present. Anisotropic temperature-dependent magnetic susceptibilities for single crystals show that Zn-stabilized CePtIn4 orders magnetically at ˜1.9 K. High-temperature Curie-Weiss fits indicate an effective moment of ˜2.49 μB/Ce and a directionally averaged Weiss-temperature of approximately -31 K. Specific heat data shows a peak consistent with the ordering temperature seen in the magnetic susceptibility data. Zn-stabilized CePtIn4 is metallic and displays no superconducting transition down to 0.14 K.

Effect of Yb(3+) on the Crystal Structural Modification and Photoluminescence Properties of GGAG:Ce(3+).

PubMed

Luo, Zhao-Hua; Liu, Yong-Fu; Zhang, Chang-Hua; Zhang, Jian-Xin; Qin, Hai-Ming; Jiang, Hao-Chuan; Jiang, Jun

2016-03-21

Gadolinium gallium aluminum garnet (GGAG) is a very promising host for the highly efficient luminescence of Ce(3+) and shows potential in radiation detection applications. However, the thermodynamically metastable structure would be slanted against it from getting high transparency. To stabilize the crystal structure of GGAG, Yb(3+) ions were codoped at the Gd(3+) site. It is found that the decomposition of garnet was suppressed and the transparency of GGAG ceramic was evidently improved. Moreover, the photoluminescence of GGAG:Ce(3+),xYb(3+) with different Yb(3+) contents has been investigated. When the Ce(3+) ions were excited under 475 nm, a typical near-infrared region emission of Yb(3+) ions can be observed, where silicon solar cells have the strongest absorption. Basing on the lifetimes of Ce(3+) ions in the GGAG:Ce(3+),xYb(3+) sample, the transfer efficiency from Ce(3+) to Yb(3+) and the theoretical internal quantum efficiency can be calculated and reach up to 86% and 186%, respectively. This would make GGAG:Ce(3+),Yb(3+) a potential attractive downconversion candidate for improving the energy conversion efficiency of crystalline silicon (c-Si) solar cells.

Auditory Brainstem Responses for Click and CE-chirp Stimuli in Individuals with and without Occupational Noise Exposure

PubMed Central

Pushpalatha, Zeena Venkatacheluvaiah; Konadath, Sreeraj

2016-01-01

Introduction: Encoding of CE-chirp and click stimuli in auditory system was studied using auditory brainstem responses (ABRs) among individuals with and without noise exposure. Materials and Methods: The study consisted of two groups. Group 1 (experimental group) consisted of 20 (40 ears) individuals exposed to occupational noise with hearing thresholds within 25 dB HL. They were further divided into three subgroups based on duration of noise exposure (0–5 years of exposure-T1, 5–10 years of exposure-T2, and >10 years of exposure-T3). Group 2 (control group) consisted of 20 individuals (40 ears). Absolute latency and amplitude of waves I, III, and V were compared between the two groups for both click and CE-chirp stimuli. T1, T2, and T3 groups were compared for the same parameters to see the effect of noise exposure duration on CE-chirp and click ABR. Result: In Click ABR, while both the parameters for wave III were significantly poorer for the experimental group, wave V showed a significant decline in terms of amplitude only. There was no significant difference obtained for any of the parameters for wave I. In CE-Chirp ABR, the latencies for all three waves were significantly prolonged in the experimental group. However, there was a significant decrease in terms of amplitude in only wave V for the same group. Discussion: Compared to click evoked ABR, CE-Chirp ABR was found to be more sensitive in comparison of latency parameters in individuals with occupational noise exposure. Monitoring of early pathological changes at the brainstem level can be studied effectively by using CE-Chirp stimulus in comparison to click stimulus. Conclusion: This study indicates that ABR's obtained with CE-chirp stimuli serves as an effective tool to identify the early pathological changes due to occupational noise exposure when compared to click evoked ABR. PMID:27762255

Effects of chlorimuron-ethyl application with or without urea fertilization on soil ammonia-oxidizing bacteria and archaea.

PubMed

Tan, Huanbo; Xu, Mingkai; Li, Xinyu; Zhang, Huiwen; Zhang, Chenggang

2013-09-15

Chlorimuron-ethyl (CE) has been widely used in modern agriculture, but little is known regarding the influence of CE on ammonia-oxidizing bacteria (AOB) and archaea (AOA) populations in soils. In this study, microcosm incubation of aquic brown soil was conducted for 60 d. Associated changes in the population sizes of AOB and AOA in response to CE application with or without urea fertilization were examined via quantitative real-time PCR (qPCR) assays of the ammonia monooxygenase gene (amoA). The half-life of CE ranged from 11.80 d to 14.54 d in the tested soil. Compared to the untreated control, the application of CE alone had no strong effects on soil pH, and urea fertilization temporarily increased soil pH in the first 7 days. The abundance of the AOA amoA gene was greater than the abundance of the AOB amoA gene in all treatments, but both were significantly suppressed by CE application in a dose-dependent manner. Urea fertilization generally increased AOB and AOA amoA gene abundances, except that the AOA amoA gene level was slightly reduced at the early stage of the incubation period. AOB and AOA preferred different N levels for growth, with AOB only growing significantly at high NH4(+) levels and AOA growing substantially at low NH₄(+) levels. The stimulation effects of urea fertilization on AOA and AOB amoA gene abundances were strongly suppressed by the CE application. This study indicated that the CE application substantially suppressed soil nitrification via inhibiting the AOB and AOA population regardless of urea fertilization, which resulted in significant changes in the soil NH₄(+)-N and NO₃(-)-N levels. Furthermore, AOB and AOA inhabiting separate ecological niches with different NH₄(+) levels played various roles in N cycling. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of injection rate on contrast-enhanced MR angiography image quality: Modulation transfer function analysis.

PubMed

Clark, Toshimasa J; Wilson, Gregory J; Maki, Jeffrey H

2017-07-01

Contrast-enhanced (CE)-MRA optimization involves interactions of sequence duration, bolus timing, contrast recirculation, and both R 1 relaxivity and R2*-related reduction of signal. Prior data suggest superior image quality with slower gadolinium injection rates than typically used. A computer-based model of CE-MRA was developed, with contrast injection, physiologic, and image acquisition parameters varied over a wide gamut. Gadolinium concentration was derived using Verhoeven's model with recirculation, R 1 and R2* calculated at each time point, and modulation transfer curves used to determine injection rates, resulting in optimal resolution and image contrast for renal and carotid artery CE-MRA. Validation was via a vessel stenosis phantom and example patients who underwent carotid CE-MRA with low effective injection rates. Optimal resolution for renal and carotid CE-MRA is achieved with injection rates between 0.5 to 0.9 mL/s and 0.2 to 0.3 mL/s, respectively, dependent on contrast volume. Optimal image contrast requires slightly faster injection rates. Expected signal-to-noise ratio varies with both contrast volume and cardiac output. Simulated vessel phantom and clinical carotid CE-MRA exams at an effective contrast injection rate of 0.4 to 0.5 mL/s demonstrate increased resolution. Optimal image resolution is achieved at intuitively low, effective injection rates (0.2-0.9 mL/s, dependent on imaging parameters and contrast injection volume). Magn Reson Med 78:357-369, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Role of flue gas components in mercury oxidation over TiO2 supported MnOx-CeO2 mixed-oxide at low temperature.

PubMed

Li, Hailong; Wu, Chang-Yu; Li, Ying; Li, Liqing; Zhao, Yongchun; Zhang, Junying

2012-12-01

MnO(x)-CeO(2) mixed-oxide supported on TiO(2) (Mn-Ce/Ti) was synthesized by an ultrasound-assisted impregnation method and employed to oxidize elemental mercury (Hg(0)) at 200°C in simulated coal combustion flue gas. Over 90% of Hg(0) oxidation was achieved on the Mn-Ce/Ti catalyst at 200°C under simulated flue gas representing those from burning low-rank coals with a high gas hourly space velocity of 60,000 h(-1). Gas-phase O(2) regenerated the lattice oxygen and replenished the chemisorbed oxygen, which facilitated Hg(0) oxidation. HCl was the most effective flue gas component responsible for Hg(0) oxidation. 10 ppm HCl plus 4% O(2) resulted in 100% Hg(0) oxidation under the experimental conditions. SO(2) competed with Hg(0) for active sites, thus deactivating the catalyst's capability in oxidizing Hg(0). NO covered the active sites and consumed surface oxygen active for Hg(0) oxidation, hence limiting Hg(0) oxidation. Water vapor showed prohibitive effect on Hg(0) oxidation due to its competition with HCl and Hg(0) for active adsorption sites. This study provides information about the promotional or inhibitory effects of individual flue gas components on Hg(0) oxidation over a highly effective Mn-Ce/Ti catalyst. Such knowledge is of fundamental importance for industrial applications of the Mn-Ce/Ti catalyst in coal-fired power plants. Copyright © 2012 Elsevier B.V. All rights reserved.

The Endocannabinoid System Tonically Regulates Inhibitory Transmission and Depresses the Effect of Ethanol in Central Amygdala

PubMed Central

Roberto, Marisa; Cruz, Maureen; Bajo, Michal; Siggins, George R; Parsons, Loren H; Schweitzer, Paul

2010-01-01

The central amygdala (CeA) has a major role in alcohol dependence and reinforcement, and behavioral and neurochemical evidence suggests a role for the endocannabinoid (eCB) system in ethanol binging and dependence. We used a slice preparation to investigate the physiological role of cannabinoids and their interaction with ethanol on inhibitory synaptic transmission in CeA. Superfusion of the cannabinoid receptor (CB1) agonist WIN55212-2 (WIN2) onto CeA neurons decreased evoked GABAA receptor-mediated inhibitory postsynaptic potentials (IPSPs) in a concentration-dependent manner, an effect prevented by the CB1 antagonists Rimonabant (SR141716, SR1) and AM251. SR1 or AM251 applied alone augmented IPSPs, revealing a tonic eCB activity that decreased inhibitory transmission in CeA. Paired-pulse analysis suggested a presynaptic CB1 mechanism. Intracellular BAPTA abolished the ability of AM251 to augment IPSPs, demonstrating the eCB-driven nature and postsynaptic origin of the tonic CB1-dependent control of GABA release. Superfusion of ethanol increased IPSPs and addition of WIN2 reversed the ethanol effect. Similarly, previous superfusion of WIN2 prevented subsequent ethanol effects on GABAergic transmission. The ethanol-induced augmentation of IPSPs was additive to CB1 blockade, ruling out a participation of CB1 in the action of acute ethanol. Our study points to an important role of CB1 in CeA in which the eCBs tonically regulate neuronal activity, and suggests a potent mechanism for modulating CeA tone during challenge with ethanol. PMID:20463657

Comparison of preparation methods for ceria catalyst and the effect of surface and bulk sulfates on its activity toward NH3-SCR.

PubMed

Chang, Huazhen; Ma, Lei; Yang, Shijian; Li, Junhua; Chen, Liang; Wang, Wei; Hao, Jiming

2013-11-15

A series of CeO2 catalysts prepared with sulfate (S) and nitrate (N) precursors by hydrothermal (H) and precipitation (P) methods were investigated in selective catalytic reduction of NOx by NH3 (NH3-SCR). The catalytic activity of CeO2 was significantly affected by the preparation methods and the precursor type. CeO2-SH, which was prepared by hydrothermal method with cerium (IV) sulfate as a precursor, showed excellent SCR activity and high N2 selectivity in the temperature range of 230-450 °C. Based on the results obtained by temperature-programmed reduction (H2-TPR), transmission infrared spectra (IR) and thermal gravimetric analysis (TGA), the excellent performance of CeO2-SH was correlated with the surface sulfate species formed in the hydrothermal reaction. These results indicated that sulfate species bind with Ce(4+) on the CeO2-SH catalyst, and the specific sulfate species, such as Ce(SO4)2 or CeOSO4, were formed. The adsorption of NH3 was promoted by these sulfate species, and the probability of immediate oxidation of NH3 to N2O on Ce(4+) was reduced. Accordingly, the selective oxidation of NH3 was enhanced, which contributed to the high N2 selectivity in the SCR reaction. However, the location of sulfate on the CeO2-SP catalyst was different. Plenty of sulfate species were likely deposited on CeO2-SP surface, covering the active sites for NO oxidation, which resulted in poor SCR activity in the test temperature range. Moreover, the resistance to alkali metals, such as Na and K, was improved over the CeO2-SH catalyst. Copyright © 2013 Elsevier B.V. All rights reserved.

Evaluation of Pd Nanoparticle-Decorated CeO2-MWCNT Nanocomposite as an Electrocatalyst for Formic Acid Fuel Cells

NASA Astrophysics Data System (ADS)

Saleem, Junaid; Safdar Hossain, SK.; Al-Ahmed, Amir; Rahman, Ateequr; McKay, Gordon; Hossain, Mohammed M.

2018-04-01

In this work, CeO2-modified Pd/CeO2-carbon nanotube (CNT) electrocatalyst for the electro-oxidation of formic acid has been investigated. The support CNT was first modified with different amounts (5-30 wt.%) of CeO2 using a precipitation-deposition method. The electrocatalysts were developed by dispersing Pd on the CeO2-CNT supports using the borohydride reduction method. The synthesized electrocatalysts were analyzed for composition, morphology and electronic structure using x-ray diffraction (XRD), scanning electron microscopy with energy-dispersive x-ray spectroscopy (SEM/EDX), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA) techniques. The formation of Pd nanoparticles on the CeO2-CNT support was confirmed using TEM. The activity of Pd/CeO2-CNT and of Pd-CNT samples upon oxidation of formic acid was evaluated by using carbon monoxide stripping voltammetry, cyclic voltammetry, and chronoamperometry. The addition of moderate amounts of cerium oxide (up to 10 wt.%) significantly improved the activity of Pd/CeO2-CNT compared to the unmodified Pd-CNT. Pd/10 wt.% CeO2-CNT showed a current density of 2 A mg-1, which is ten times higher than that of the unmodified Pd-CNT (0.2 A mg-1). Similarly, the power density obtained for Pd/10 wt.% CeO2-CNT in an air-breathing formic acid fuel cell was 6.8 mW/cm2 which is two times higher than Pd-CNT (3.2 mW/cm2), thus exhibiting the promotional effects of CeO2 to Pd/CeO2-CNT. A plausible justification for the improved catalytic performance and stability is provided in the light of the physical characterization results.

Photoluminescence properties and energy transfer in Ce(3+) /Dy(3+) co-doped Sr(3) MgSi(2) O(8) phosphors for potential application in ultraviolet white light-emitting diodes.

PubMed

Yu, Hong; Zi, Wenwen; Lan, Shi; Gan, Shucai; Zou, Haifeng; Xu, Xuechun; Hong, Guangyan

2013-01-01

Sr(3) MgSi(2) O(8) :Ce(3+) , Dy(3+) phosphors were prepared by a solid-state reaction technique and the photoluminescence properties were investigated. The emission spectra show not only a band due to Ce(3+) ions (403 nm) but also as a band due to Dy(3+) ions (480, 575 nm) (UV light excitation). The photoluminescence properties reveal that effective energy transfer occurs in Ce(3+) /Dy(3+) co-doped Sr(3) MgSi(2) O(8)phosphors, and the co-doping of Ce(3+) could enhance the emission intensity of Dy(3+) to a certain extent by transferring its energy to Dy(3+) . The Ce(3+) /Dy(3+) energy transfer was investigated by emission/excitation spectra, and photoluminescence decay behaviors. In Sr2.94 MgSi2 O8 :0.01Ce(3+) , 0.05Dy(3+) phosphors, the fluorescence lifetime of Dy(3+) (from 3.35 to 27.59 ns) is increased whereas that of Ce(3+) is greatly decreased (from 43.59 to 13.55 ns), and this provides indirect evidence of the Ce(3+) to Dy(3+) energy transfer. The varied emitted color of Sr(3) MgSi(2) O(8):Ce(3+) , Dy(3+) phosphors from blue to white were achieved by altering the concentration ratio of Ce(3+) and Dy(3+) . These results indicate Sr(3) MgSi(2) O(8):Ce(3+) , Dy(3+) may be as a candidate phosphor for white light-emitting diodes. Copyright © 2012 John Wiley & Sons, Ltd.

Synthesis and effect of Ce and Mn co-doping on photoluminescence characteristics of Ca6AlP5O20:Eu novel phosphors.

PubMed

Shinde, K N; Dhoble, S J

2013-01-01

A series of Ca6AlP5O20 doped with rare earths (Eu and Ce) and co-doped (Eu, Ce and Eu,Mn) were prepared by combustion synthesis. Under Hg-free excitation, Ca6AlP5O20:Eu exhibited Eu(2+) (486 nm) emission in the blue region of the spectrum and under near Hg excitation (245 nm), Ca6AlP5O20:Ce phosphor exhibited Ce(3+) emission (357 nm) in the UV range. Photoluminescence (PL) peak intensity increased in Ca6AlP5O20:Eu,Ce and Ca6AlP5O20:Eu, Mn phosphors due to co-activators of Ce(3+) and Mn(2+) ions. As a result, these ions played an important role in PL emission in the present matrix. Ca6AlP5O20:Eu, Ce and Ca6AlP5O20:Eu, Mn phosphors provided energy transfer mechanisms via Ce(3+) → Eu(2+) and Eu(2+) → Mn(2+), respectively. Eu ions acted as activators and Ce ions acted as sensitizers. Ce emission energy was well matched with Eu excitation energy in the case of Ca6AlP5O20:Eu, Ce and Eu ions acted as activators and Mn ions acted as sensitizers in Ca6AlP5O20:Eu, Mn. This study included synthesis of new and efficient phosphate phosphors. The impact of doping and co-doping on photoluminescence properties and energy transfer mechanisms were investigated and we propose a feasible interpretation. Copyright © 2012 John Wiley & Sons, Ltd.

A Strategy to enhance Eu3+ emission from LiYF4:Eu nanophosphors and green-to-orange multicolor tunable, transparent nanophosphor-polymer composites

PubMed Central

Kim, Su Yeon; Won, Yu-Ho; Jang, Ho Seong

2015-01-01

LiYF4:Eu nanophosphors with a single tetragonal phase are synthesized, and various strategies to enhance the Eu3+ emission from the nanophosphors are investigated. The optimized Eu3+ concentration is 35 mol%, and the red emission peaks due to the 5D0 →7FJ (J = 1 and 2) transitions of Eu3+ ions are further enhanced by energy transfer from a sensitizer pair of Ce3+ and Tb3+. The triple doping of Ce, Tb, and Eu into the LiYF4 host more effectively enhances the Eu3+ emission than the core/shell strategies of LiYF4:Eu(35%)/LiYF4:Ce(15%), Tb(15%) and LiYF4:Ce(15%), Tb(15%)/LiYF4:Eu(35%) architectures. Efficient energy transfer from Ce3+ to Eu3+ through Tb3+ results in three times higher Eu3+ emission intensity from LiYF4:Ce(15%), Tb(15%), Eu(1%) nanophosphors compared with LiYF4:Eu(35%), which contains the optimized Eu3+ concentration. Owing to the energy transfer of Ce3+ → Tb3+ and Ce3+ → Tb3+ → Eu3+, intense green and red emission peaks are observed from LiYF4:Ce(13%), Tb(14%), Eu(1-5%) (LiYF4:Ce, Tb, Eu) nanophosphors, and the intensity ratio of green to red emission is controlled by adjusting the Eu3+ concentration. With increasing Eu3+ concentration, the LiYF4:Ce, Tb, Eu nanophosphors exhibit multicolor emission from green to orange. In addition, the successful incorporation of LiYF4:Ce, Tb, Eu nanophosphors into polydimethylsiloxane (PDMS) facilitates the preparation of highly transparent nanophosphor-PDMS composites that present excellent multicolor tunability. PMID:25597900

Covalency in lanthanides. An X-ray absorption spectroscopy and density functional theory study of LnCl6(x-) (x = 3, 2).

PubMed

Löble, Matthias W; Keith, Jason M; Altman, Alison B; Stieber, S Chantal E; Batista, Enrique R; Boland, Kevin S; Conradson, Steven D; Clark, David L; Lezama Pacheco, Juan; Kozimor, Stosh A; Martin, Richard L; Minasian, Stefan G; Olson, Angela C; Scott, Brian L; Shuh, David K; Tyliszczak, Tolek; Wilkerson, Marianne P; Zehnder, Ralph A

2015-02-25

Covalency in Ln-Cl bonds of Oh-LnCl6(x-) (x = 3 for Ln = Ce(III), Nd(III), Sm(III), Eu(III), Gd(III); x = 2 for Ln = Ce(IV)) anions has been investigated, primarily using Cl K-edge X-ray absorption spectroscopy (XAS) and time-dependent density functional theory (TDDFT); however, Ce L3,2-edge and M5,4-edge XAS were also used to characterize CeCl6(x-) (x = 2, 3). The M5,4-edge XAS spectra were modeled using configuration interaction calculations. The results were evaluated as a function of (1) the lanthanide (Ln) metal identity, which was varied across the series from Ce to Gd, and (2) the Ln oxidation state (when practical, i.e., formally Ce(III) and Ce(IV)). Pronounced mixing between the Cl 3p- and Ln 5d-orbitals (t2g* and eg*) was observed. Experimental results indicated that Ln 5d-orbital mixing decreased when moving across the lanthanide series. In contrast, oxidizing Ce(III) to Ce(IV) had little effect on Cl 3p and Ce 5d-orbital mixing. For LnCl6(3-) (formally Ln(III)), the 4f-orbitals participated only marginally in covalent bonding, which was consistent with historical descriptions. Surprisingly, there was a marked increase in Cl 3p- and Ce(IV) 4f-orbital mixing (t1u* + t2u*) in CeCl6(2-). This unexpected 4f- and 5d-orbital participation in covalent bonding is presented in the context of recent studies on both tetravalent transition metal and actinide hexahalides, MCl6(2-) (M = Ti, Zr, Hf, U).

78 FR 38552 - Airworthiness Directives; Cessna Aircraft Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-27

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2012-1052; Directorate Identifier 2012-CE-014-AD; Amendment 39-17471; AD 2013-11-11] RIN 2120-AA64...; Docket No. FAA-2012-1052; Directorate Identifier 2012-CE-014-AD. (a) Effective Date This AD is effective...

Cerium dioxide nanoparticles exacerbate house dust mite induced type II airway inflammation.

PubMed

Meldrum, Kirsty; Robertson, Sarah B; Römer, Isabella; Marczylo, Tim; Dean, Lareb S N; Rogers, Andrew; Gant, Timothy W; Smith, Rachel; Tetley, Terry D; Leonard, Martin O

2018-05-23

Nanomaterial inhalation represents a potential hazard for respiratory conditions such as asthma. Cerium dioxide nanoparticles (CeO 2 NPs) have the ability to modify disease outcome but have not been investigated for their effect on models of asthma and inflammatory lung disease. The aim of this study was to examine the impact of CeO 2 NPs in a house dust mite (HDM) induced murine model of asthma. Repeated intranasal instillation of CeO 2 NPs in the presence of HDM caused the induction of a type II inflammatory response, characterised by increased bronchoalveolar lavage eosinophils, mast cells, total plasma IgE and goblet cell metaplasia. This was accompanied by increases in IL-4, CCL11 and MCPT1 gene expression together with increases in the mucin and inflammatory regulators CLCA1 and SLC26A4. CLCA1 and SLC26A4 were also induced by CeO 2 NPs + HDM co-exposure in air liquid interface cultures of human primary bronchial epithelial cells. HDM induced airway hyperresponsiveness and airway remodelling in mice were not altered with CeO 2 NPs co-exposure. Repeated HMD instillations followed by a single exposure to CeO 2 NPs failed to produce changes in type II inflammatory endpoints but did result in alterations in the neutrophil marker CD177. Treatment of mice with CeO 2 NPs in the absence of HDM did not have any significant effects. RNA-SEQ was used to explore early effects 24 h after single treatment exposures. Changes in SAA3 expression paralleled increased neutrophil BAL levels, while no changes in eosinophil or lymphocyte levels were observed. HDM resulted in a strong induction of type I interferon and IRF3 dependent gene expression, which was inhibited with CeO 2 NPs co-exposure. Changes in the expression of genes including CCL20, CXCL10, NLRC5, IRF7 and CLEC10A suggest regulation of dendritic cells, macrophage functionality and IRF3 modulation as key early events in how CeO 2 NPs may guide pulmonary responses to HDM towards type II inflammation. CeO 2 NPs were observed to modulate the murine pulmonary response to house dust mite allergen exposure towards a type II inflammatory environment. As this type of response is present within asthmatic endotypes this finding may have implications for how occupational or incidental exposure to CeO 2 NPs should be considered for those susceptible to disease.

Feasibility of liquid nitrogen cryotherapy after failed radiofrequency ablation for Barrett's esophagus.

PubMed

Trindade, Arvind J; Inamdar, Sumant; Kothari, Shivangi; Berkowitz, Joshua; McKinley, Matthew; Kaul, Vivek

2017-09-01

Radiofrequency ablation (RFA) for dysplastic Barrett's esophagus (BE) is highly effective. RFA failures are infrequent but can be a challenging cohort to manage. There are limited data on the feasibility of liquid nitrogen cryospray ablation for complete eradication of dysplasia (CE-D) and/or intestinal metaplasia (CE-IM) after RFA has failed to achieve CE-IM in patients with dysplastic BE. This is a retrospective review from two medical centers of prospectively maintained databases looking at patients that underwent liquid nitrogen cryospray ablation for refractory intestinal metaplasia post failed RFA. Eighteen patients were identified that met inclusion criteria. Eleven patients had persistent dysplasia and IM following RFA and seven had persistent non-dysplastic IM. More than 80% of patients were male with long-segment BE (median length 8 cm). Seventy two percent of patients with dysplasia achieved CE-D after cryotherapy. Fifty percent (9/18) of all RFA failures achieved CE-IM with cryotherapy. In comparison, RFA has a CE-IM of 78% in a less challenging treatment naïve cohort from a large-scale meta-analysis of 3802 patients. No adverse events occurred in our cohort. Cryospray ablation is feasible and safe for achieving CE-D and CE-IM after RFA failure. The CE-D rates are high with cryotherapy in this population. CE-IM with cryotherapy is acceptable in this difficult-to-treat cohort when compared to CE-IM rates with RFA in dysplastic BE treatment naïve patients (50% vs 78%). © 2017 Japan Gastroenterological Endoscopy Society.

Hydrodeoxygenation of p -Cresol over Pt/Al 2 O 3 Catalyst Promoted by ZrO 2 , CeO 2 , and CeO 2 –ZrO 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Weiyan; Wu, Kui; Liu, Pengli

2016-07-20

ZrO 2-Al 2O 3 and CeO 2-Al 2O 3 were prepared by a co-precipitation method and selected as supports for Pt catalysts. The effects of CeO 2 and ZrO 2 on the surface area and Brønsted acidity of Pt/Al 2O 3 were studied. In the hydrodeoxygenation (HDO) of p-cresol, the addition of ZrO 2 promoted the direct deoxygenation activity on Pt/ZrOO 2-Al 2O 3 via Caromatic-O bond scission without benzene ring saturation. Pt/CeOO 2-Al 2O 3 exhibited higher deoxygenation extent than Pt/Al 2O 3 due to the fact that Brønsted acid sites on the catalyst surface favored the adsorption ofmore » p-cresol. With the advantages of CeO 2 and ZrO 2 taken into consideration, CeO 2-ZrOO 2-Al 2O 3 was prepared, leading to the highest HDO activity of Pt/CeO 2-ZrOO 2-Al 2O 3. The deoxygenation extent for Pt/CeO 2-ZrOO 2-Al 2O 3 was 48.4% and 14.5% higher than that for Pt/ZrO2O 2-Al 2O 3 and Pt/CeOO 2-Al 2O 3, respectively.« less

Magnetic ordered mesoporous Fe3O4/CeO2 composites with synergy of adsorption and Fenton catalysis

NASA Astrophysics Data System (ADS)

Li, Keyan; Zhao, Yongqin; Song, Chunshan; Guo, Xinwen

2017-12-01

Magnetic Fe3O4/CeO2 composites with highly ordered mesoporous structure and large surface area were synthesized by impregnation-calcination method, and the mesoporous CeO2 as support was synthesized via the hard template approach. The composition, morphology and physicochemical properties of the materials were characterized by XRD, SEM, TEM, XPS, Raman spectra and N2 adsorption/desorption analysis. The mesoporous Fe3O4/CeO2 composite played a dual-function role as both adsorbent and Fenton-like catalyst for removal of organic dye. The methylene blue (MB) removal efficiency of mesoporous Fe3O4/CeO2 was much higher than that of irregular porous Fe3O4/CeO2. The superior adsorption ability of mesoporous materials was attributed to the abundant oxygen vacancies on the surface of CeO2, high surface area and ordered mesoporous channels. The good oxidative degradation resulted from high Ce3+ content and the synergistic effect between Fe and Ce. The mesoporous Fe3O4/CeO2 composite presented low metal leaching (iron 0.22 mg L-1 and cerium 0.63 mg L-1), which could be ascribed to the strong metal-support interactions for dispersion and stabilization of Fe species. In addition, the composite can be easily separated from reaction solution with an external magnetic field due to its magnetic property, which is important to its practical applications.

Transfer hydrogenation over sodium-modified ceria: Enrichment of redox sites active for alcohol dehydrogenation

DOE PAGES

Nelson, Nicholas C.; Boote, Brett W.; Naik, Pranjali; ...

2017-01-17

Ceria (CeO 2) and sodium-modified ceria (Ce-Na) were prepared through combustion synthesis. Palladium was deposited onto the supports (Pd/CeO 2 and Pd/Ce-Na) and their activity for the aqueous-phase transfer hydrogenation of phenol using 2-propanol under liquid flow conditions was studied. Pd/Ce-Na showed a marked increase (6×) in transfer hydrogenation activity over Pd/CeO 2. Material characterization indicated that water-stable sodium species were not doped into the ceria lattice, but rather existed as subsurface carbonates. Modification of ceria by sodium provided more adsorption and redox active sites (i.e. defects) for 2-propanol dehydrogenation. This effect was an intrinsic property of the Ce-Na supportmore » and independent of Pd. The redox sites active for 2-propanol dehydrogenation were thermodynamically equivalent on both supports/catalysts. At high phenol concentrations, the reaction was limited by 2-propanol adsorption. Furthermore, the difference in catalytic activity was attributed to the different numbers of 2-propanol adsorption and redox active sites on each catalyst.« less

A Systematic Review of the Literature on Cystic Echinococcosis Frequency Worldwide and Its Associated Clinical Manifestations

PubMed Central

Budke, Christine M.; Carabin, Hélène; Ndimubanzi, Patrick C.; Nguyen, Hai; Rainwater, Elizabeth; Dickey, Mary; Bhattarai, Rachana; Zeziulin, Oleksandr; Qian, Men-Bao

2013-01-01

A systematic literature review of cystic echinoccocosis (CE) frequency and symptoms was conducted. Studies without denominators, original data, or using one serological test were excluded. Random-effect log-binomial models were run for CE frequency and proportion of reported symptoms where appropriate. A total of 45 and 25 articles on CE frequency and symptoms met all inclusion criteria. Prevalence of CE ranged from 1% to 7% in community-based studies and incidence rates ranged from 0 to 32 cases per 100,000 in hospital-based studies. The CE prevalence was higher in females (Prevalence Proportion Ratio: 1.35 [95% Bayesian Credible Interval: 1.16–1.53]) and increased with age. The most common manifestations of hepatic and pulmonary CE were abdominal pain (57.3% [95% confidence interval [CI]: 37.3–76.1%]) and cough (51.3% [95% CI: 35.7–66.7%]), respectively. The results are limited by the small number of unbiased studies. Nonetheless, the age/gender prevalence differences could be used to inform future models of CE burden. PMID:23546806

A systematic review of the literature on cystic echinococcosis frequency worldwide and its associated clinical manifestations.

PubMed

Budke, Christine M; Carabin, Hélène; Ndimubanzi, Patrick C; Nguyen, Hai; Rainwater, Elizabeth; Dickey, Mary; Bhattarai, Rachana; Zeziulin, Oleksandr; Qian, Men-Bao

2013-06-01

A systematic literature review of cystic echinoccocosis (CE) frequency and symptoms was conducted. Studies without denominators, original data, or using one serological test were excluded. Random-effect log-binomial models were run for CE frequency and proportion of reported symptoms where appropriate. A total of 45 and 25 articles on CE frequency and symptoms met all inclusion criteria. Prevalence of CE ranged from 1% to 7% in community-based studies and incidence rates ranged from 0 to 32 cases per 100,000 in hospital-based studies. The CE prevalence was higher in females (Prevalence Proportion Ratio: 1.35 [95% Bayesian Credible Interval: 1.16-1.53]) and increased with age. The most common manifestations of hepatic and pulmonary CE were abdominal pain (57.3% [95% confidence interval [CI]: 37.3-76.1%]) and cough (51.3% [95% CI: 35.7-66.7%]), respectively. The results are limited by the small number of unbiased studies. Nonetheless, the age/gender prevalence differences could be used to inform future models of CE burden.

Homoleptic Ce(III) and Ce(IV) Nitroxide Complexes: Significant Stabilization of the 4+ Oxidation State

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bogart, Justin A.; Lewis, Andrew J.; Medling, Scott A.

2014-06-25

Electrochemical experiments performed on the complex Ce-IV[2-((BuNO)-Bu-t)py](4), where [2-((BuNO)-Bu-t)py](-) = N-tert-butyl-N-2-pyridylnitroxide, indicate a 2.51 V stabilization of the 4+ oxidation state of Ce compared to [(Bu4N)-Bu-n](2)[Ce(NO3)(6)] in acetonitrile and a 2.95 V stabilization compared to the standard potential for the ion under aqueous conditions. Density functional theory calculations suggest that this preference for the higher oxidation state is a result of the tetrakis(nitroxide) ligand framework at the Ce cation, which allows for effective electron donation into, and partial covalent overlap with, vacant 4f orbitals with delta symmetry. The results speak to the behavior of CeO2 and related solid solutions inmore » oxygen uptake and transport applications, in particular an inherent local character of bonding that stabilizes the 4+ oxidation state. The results indicate a cerium(IV) complex that has been stabilized to an unprecedented degree through tuning of its ligand-field environment.« less

Sci-Thur AM: YIS – 04: Stopping power-to-Cherenkov power ratios and beam quality specification for clinical Cherenkov emission dosimetry of electrons: beam-specific effects and experimental validation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zlateva, Yana; Seuntjens, Jan; El Naqa, Issam

Purpose: To advance towards clinical Cherenkov emission (CE)-based dosimetry by investigating beam-specific effects on Monte Carlo-calculated electron-beam stopping power-to-CE power ratios (SCRs), addressing electron beam quality specification in terms of CE, and validating simulations with measurements. Methods: The EGSnrc user code SPRRZnrc, used to calculate Spencer-Attix stopping-power ratios, was modified to instead calculate SCRs. SCRs were calculated for 6- to 22-MeV clinical electron beams from Varian TrueBeam, Clinac 21EX, and Clinac 2100C/D accelerators. Experiments were performed with a 20-MeV electron beam from a Varian TrueBeam accelerator, using a diffraction grating spectrometer with optical fiber input and a cooled back-illuminated CCD.more » A fluorophore was dissolved in the water to remove CE signal anisotropy. Results: It was found that angular spread of the incident beam has little effect on the SCR (≤ 0.3% at d{sub max}), while both the electron spectrum and photon contamination increase the SCR at shallow depths and decrease it at large depths. A universal data fit of R{sub 50} in terms of C{sub 50} (50% CE depth) revealed a strong linear dependence (R{sup 2} > 0.9999). The SCR was fit with a Burns-type equation (R{sup 2} = 0.9974, NRMSD = 0.5%). Below-threshold incident radiation was found to have minimal effect on beam quality specification (< 0.1%). Experiments and simulations were in good agreement. Conclusions: Our findings confirm the feasibility of the proposed CE dosimetry method, contingent on computation of SCRs from additional accelerators and on further experimental validation. This work constitutes an important step towards clinical high-resolution out-of-beam CE dosimetry.« less

Combined effects Na and SO2 in flue gas on Mn-Ce/TiO2 catalyst for low temperature selective catalytic reduction of NO by NH3 simulated by Na2SO4 doping

NASA Astrophysics Data System (ADS)

Zhou, Aiyi; Yu, Danqing; Yang, Liu; Sheng, Zhongyi

2016-08-01

A series of Mn-Ce/TiO2 catalysts were synthesized through an impregnation method and used for low temperature selective catalytic reduction (SCR) of NOx with ammonia (NH3). Na2SO4 was added into the catalyst to simulate the combined effects of alkali metal and SO2 in the flue gas. Experimental results showed that Na2SO4 had strong and fluctuant influence on the activity of Mn-Ce/TiO2, because the effect of Na2SO4 included pore occlusion and sulfation effect simultaneously. When Na2SO4 loading content increased from 0 to 1 wt.%, the SCR activities of Na2SO4-doped catalysts decreased greatly. With further increasing amount of Na2SO4, however, the catalytic activity increased gradually. XRD results showed that Na2SO4 doping could induce the crystallization of MnOx phases, which were also confirmed by TEM and SEM results. BET results showed that the surface areas decreased and a new bimodal mesoporous structure formed gradually with the increasing amount of Na2SO4. XPS results indicated that part of Ce4+ and Mn3+ were transferred to Ce3+ and Mn4+ due to the sulfation after Na2SO4 deposition on the surface of the catalysts. When the doped amounts of Na2SO4 increased, NH3-TPD results showed that the Lewis acid sites decreased and the Brønsted acid sites of Mn-Ce/TiO2 increased quickly, which could be considered as another reason for the observed changes in the catalytic activity. The decreased Mn and Ce atomic concentration, the changes of their oxidative states, and the variation in acidic properties on the surface of Na2SO4-doped catalysts could be the reasons for the fluctuant changes of the catalytic activity.

Bioaccumulation of CeO2 Nanoparticles by Earthworms in Biochar-Amended Soil: A Synchrotron Microspectroscopy Study.

PubMed

Servin, Alia D; Castillo-Michel, Hiram; Hernandez-Viezcas, Jose A; De Nolf, Wout; De La Torre-Roche, Roberto; Pagano, Luca; Pignatello, Joseph; Uchimiya, Minori; Gardea-Torresdey, Jorge; White, Jason C

2018-01-11

The interactions of nanoparticles (NPs) with biochar and soil components may substantially influence NP availability and toxicity to biota. In the present study, earthworms (Eisenia fetida) were exposed for 28 days to a residential or agricultural soil amended with 0-2000 mg of CeO 2 NP/kg and with biochar (produced by the pyrolysis of pecan shells at 350 and 600 °C) at various application rates [0-5% (w/w)]. After 28 days, earthworms were depurated and analyzed for Ce content, moisture content, and lipid peroxidation. The results showed minimal toxicity to the worms; however, biochar (350 or 600 °C) was the dominant factor, accounting for 94 and 84% of the variance for the moisture content and lipid peroxidation, respectively, in the exposed earthworms. For both soils with 1000 mg of CeO 2 /kg at 600 °C, biochar significantly decreased the accumulation of Ce in the worm tissues. Amendment with 350 °C biochar had mixed responses on Ce uptake. Analysis by micro X-ray fluorescence (μ-XRF) and micro X-ray absorption near edge structure (μ-XANES) was used to evaluate Ce localization, speciation, and persistence in CeO 2 - and biochar-exposed earthworms after depuration for 12, 48, and 72 h. Earthworms from the 500 mg of CeO 2 /kg and 0% biochar treatments eliminated most Ce after a 48 h depuration period. However, in the same treatment and with 5% BC-600 (biochar pyrolysis temperature of 600 °C), ingested biochar fragments (∼50 μm) with Ce adsorbed to the surfaces were retained in the gut after 72 h. Additionally, Ce remained in earthworms from the 2000 mg of CeO 2 /kg and 5% biochar treatments after depuration for 48 h. Analysis by μ-XANES showed that, within the earthworm tissues, Ce remained predominantly as Ce 4+ O 2 , with only few regions (2-3 μm 2 ) where it was found in the reduced form (Ce 3+ ). The present findings highlight that soil and biochar properties have a significant influence in the internalization of CeO 2 NPs in earthworms; such interactions need to be considered when estimating NP fate and effects in the environment.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Jane Y.C., E-mail: jym1@cdc.gov; Young, Shih-Houng; Mercer, Robert R.

Cerium compounds have been used as a fuel-borne catalyst to lower the generation of diesel exhaust particles (DEPs), but are emitted as cerium oxide nanoparticles (CeO{sub 2}) along with DEP in the diesel exhaust. The present study investigates the effects of the combined exposure to DEP and CeO{sub 2} on the pulmonary system in a rat model. Specific pathogen-free male Sprague–Dawley rats were exposed to CeO{sub 2} and/or DEP via a single intratracheal instillation and were sacrificed at various time points post-exposure. This investigation demonstrated that CeO{sub 2} induces a sustained inflammatory response, whereas DEP elicits a switch of themore » pulmonary immune response from Th1 to Th2. Both CeO{sub 2} and DEP activated AM and lymphocyte secretion of the proinflammatory cytokines IL-12 and IFN-γ, respectively. However, only DEP enhanced the anti-inflammatory cytokine IL-10 production in response to ex vivo LPS or Concanavalin A challenge that was not affected by the presence of CeO{sub 2}, suggesting that DEP suppresses host defense capability by inducing the Th2 immunity. The micrographs of lymph nodes show that the particle clumps in DEP + CeO{sub 2} were significantly larger than CeO{sub 2} or DEP, exhibiting dense clumps continuous throughout the lymph nodes. Morphometric analysis demonstrates that the localization of collagen in the lung tissue after DEP + CeO{sub 2} reflects the combination of DEP-exposure plus CeO{sub 2}-exposure. At 4 weeks post-exposure, the histological features demonstrated that CeO{sub 2} induced lung phospholipidosis and fibrosis. DEP induced lung granulomas that were not significantly affected by the presence of CeO{sub 2} in the combined exposure. Using CeO{sub 2} as diesel fuel catalyst may cause health concerns. - Highlights: • DEP induced acute lung inflammation and switched immune response from Th1 to Th2. • DEP induced lung granulomas were not affected by the presence of CeO{sub 2}. • CeO{sub 2} induced sustained lung inflammation, phospholipidosis, and fibrosis. • After the combined exposure, CeO{sub 2} and DEP are co-localized in the lung tissues. • CeO{sub 2} + DEP induced lung inflammation, phospholipidosis, granulomas, and fibrosis.« less

Exchange bias effect and glassy-like behavior of EuCrO{sub 3} and CeCrO{sub 3} nano-powders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taheri, M., E-mail: maryam.taheri@brocku.ca; Razavi, F. S.; Kremer, R. K.

2015-09-28

The magnetic properties of nano-sized EuCrO{sub 3} and CeCrO{sub 3} powders, synthesized by a solution combustion method, were investigated using DC/AC magnetization measurements. An exchange bias effect, magnetization irreversibility and AC susceptibility dispersion in these samples provided evidence for the presence of the spin disorder magnetic phase. The exchange bias phenomenon, which is assigned to the exchange coupling between the glassy-like shell and canted antiferromagnetic core, showed the opposite sign in EuCrO{sub 3} and CeCrO{sub 3} at low temperatures, suggesting different exchange interactions at the interfaces in these compounds. We also observed a sign reversal of exchange bias in CeCrO{submore » 3} at different temperatures.« less

Single cell transcriptome analysis of MCF-7 reveals consistently and inconsistently expressed gene groups each associated with distinct cellular localization and functions

PubMed Central

Chen, Tzu-Han; Shiau, Hsin-Chieh

2018-01-01

Single cell transcriptome (SCT) analysis provides superior resolution to illustrate tumor cell heterogeneity for clinical implications. We characterized four SCTs of MCF-7 using 143 housekeeping genes (HKGs) as control, of which lactate dehydrogenase B (LDHB) expression is silenced. These SCT libraries mapped to 11,423, 11,486, 10,380, and 11,306 RefSeq genes (UCSC), respectively. High consistency in HKG expression levels across all four SCTs, along with transcriptional silencing of LDHB, was observed, suggesting a high sensitivity and reproducibility of the SCT analysis. Cross-library comparison on expression levels by scatter plotting revealed a linear correlation and an 83–94% overlap in transcript isoforms and expressed genes were also observed. To gain insight of transcriptional diversity among the SCTs, expressed genes were split into consistently expressed (CE) (expressed in all SCTs) and inconsistently expressed (IE) (expressed in some but not all SCTs) genes for further characterization, along with the 142 expressed HKGs as a reference. Distinct transcriptional strengths were found among these groups, with averages of 1,612.0, 88.0 and 1.2 FPKM for HKGs, CE and IE, respectively. Comparison between CE and IE groups further indicated that expressions of CE genes vary more significantly than that of IE genes. Gene Ontology analysis indicated that proteins encoded by CE genes are mainly involved in fundamental intracellular activities, while proteins encoded by IE genes are mainly for extracellular activities, especially acting as receptors or ion channels. The diversified gene expressions, especially for those encoded by IE genes, may contribute to cancer drug resistance. PMID:29920548

DOSIMETRIC CONSEQUENCES OF USING CONTRAST-ENHANCED COMPUTED TOMOGRAPHIC IMAGES FOR INTENSITY-MODULATED STEREOTACTIC BODY RADIOTHERAPY PLANNING.

PubMed

Yoshikawa, Hiroto; Roback, Donald M; Larue, Susan M; Nolan, Michael W

2015-01-01

Potential benefits of planning radiation therapy on a contrast-enhanced computed tomography scan (ceCT) should be weighed against the possibility that this practice may be associated with an inadvertent risk of overdosing nearby normal tissues. This study investigated the influence of ceCT on intensity-modulated stereotactic body radiotherapy (IM-SBRT) planning. Dogs with head and neck, pelvic, or appendicular tumors were included in this retrospective cross-sectional study. All IM-SBRT plans were constructed on a pre- or ceCT. Contours for tumor and organs at risk (OAR) were manually constructed and copied onto both CT's; IM-SBRT plans were calculated on each CT in a manner that resulted in equal radiation fluence. The maximum and mean doses for OAR, and minimum, maximum, and mean doses for targets were compared. Data were collected from 40 dogs per anatomic site (head and neck, pelvis, and limbs). The average dose difference between minimum, maximum, and mean doses as calculated on pre- and ceCT plans for the gross tumor volume was less than 1% for all anatomic sites. Similarly, the differences between mean and maximum doses for OAR were less than 1%. The difference in dose distribution between plans made on CTs with and without contrast enhancement was tolerable at all treatment sites. Therefore, although caution would be recommended when planning IM-SBRT for tumors near "reservoirs" for contrast media (such as the heart and urinary bladder), findings supported the use of ceCT with this dose calculation algorithm for both target delineation and IM-SBRT treatment planning. © 2015 American College of Veterinary Radiology.

Continuing education needs assessment of pharmacists in the United Arab Emirates.

PubMed

Hasan, Sanah

2009-12-01

The main objective of this study was to offer an insight on the issue of continuing education (CE) in the UAE and to determine the type and format of CE pharmacists in this country prefer to attend and consider most effective. A multi-theme survey was developed to find the reasons pharmacists choose to attend different CE programs, the survey assessed continuing education needs and preferences of pharmacists. Survey items included the types of formats and topics pharmacists prefer to attend and think are most useful to enhance their knowledge and skill. Finally the survey explored some barriers pharmacists conceive as such to attending effective CE. One hundred thirty-two surveys were included in this study, the vast majority of the participants were bachelor's degree holders who were 40 years and younger. The participant's main types of employment were marketing and hospital practice. Pharmacists' preferences as for the format and topic type for programs they would like to attend were identified and compared to other practice settings. Barriers to attending effective CE programs were also elicited. Interactive workshops were recognized as the most favorable format for CE in this study, computer and internet-based formats were also ranked highly by participants followed by live-in person and printed material-based programs. Topics covering innovations in pharmacy practice and disease management were at the top of priorities for pharmacists who would also like to see more certificate programs be offered to them.

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.

Ethanol increases GABAergic transmission at both pre- and postsynaptic sites in rat central amygdala neurons

PubMed Central

Roberto, Marisa; Madamba, Samuel G.; Moore, Scott D.; Tallent, Melanie K.; Siggins, George R.

2003-01-01

We examined the interaction of ethanol with the γ-aminobutyric acid (GABA)ergic system in neurons of slices of the rat central amygdala nucleus (CeA), a brain region thought to be critical for the reinforcing effects of ethanol. Brief superfusion of 11–66 mM ethanol significantly increased GABA type A (GABAA) receptor-mediated inhibitory postsynaptic potentials (IPSPs) and currents (IPSCs) in most CeA neurons, with a low apparent EC50 of 20 mM. Acute superfusion of 44 mM ethanol increased the amplitude of evoked GABAA IPSPs and IPSCs in 70% of CeA neurons. The ethanol enhancement of IPSPs and IPSCs occurred to a similar extent in the presence of the GABA type B (GABAB) receptor antagonist CGP 55845A, suggesting that this receptor is not involved in the ethanol effect on CeA neurons. Ethanol superfusion also decreased paired-pulse facilitation of evoked GABAA IPSPs and IPSCs and always increased the frequency and sometimes the amplitude of spontaneous miniature GABAA IPSCs as well as responses to local GABA application, indicating both presynaptic and postsynaptic sites of action for ethanol. Thus, the CeA is the first brain region to reveal, without conditional treatments such as GABAB antagonists, consistent, low-dose ethanol enhancement of GABAergic transmission at both pre- and postsynaptic sites. These findings add further support to the contention that the ethanol–GABA interaction in CeA plays an important role in the reinforcing effects of ethanol. PMID:12566570

Growth of nano hexagon-like flake arrays cerium carbonate created with PAH as the substrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, M., E-mail: limei@imust.cn; School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Department of Inorganic and Metalloid Materials, Key Laboratory of New Technologies of Modern Metallurgy and Application of Rare Materials, Baotou 014010; Hu, Y.H., E-mail: bthyh@163.com

Petals-like Ce{sub 2}(CO{sub 3}){sub 3} on Ce{sub 2}(CO{sub 3}){sub 3} nano hexagon-like flake arrays have been precipitatingly fabricated using PAH substrates. By changing the way of feeding, PAH concentration and aging time, petals-like Ce{sub 2}(CO{sub 3}){sub 3} was created best when adding PAH into the Ce(NO{sub 3}){sub 3} solution, joined (NH{sub 4}){sub 2}CO{sub 3} solution along with mixing, PAH concentration is 0.9 g/L, aging time is 4 h. A growth mechanism was proposed to account for the growth of the petals-like Ce{sub 2}(CO{sub 3}){sub 3} with PAH as the substrate. Poly allylamine hydrochloride (PAH) is as template agent which formsmore » π-allyl complex with Ce{sup 3+} and controls the morphology of Ce{sub 2}(CO{sub 3}){sub 3} particle. PAH and Ce{sup 3+} form π-allyl complex, and then induce the formation of Ce{sub 2}(CO{sub 3}){sub 3} crystal nucleus. And infrared spectrum analysis verified. XRD show that after adding PAH which is adsorbed on the crystal plane, the growth of Ce{sub 2}(CO{sub 3}){sub 3} crystal is inhibited on (2 4 2), the growth is promoted on (2 0 2) which is differentiated into the new (1 5 1), (2 2 2) is unchanged, Ce{sub 2}(CO{sub 3}){sub 3} crystal is accumulated petals shape by hexagon-like flake. UV absorption spectra show that CeO{sub 2} as prepared precursor Ce{sub 2}(CO{sub 3}){sub 3} after calcinations in air at high temperatures, the petal-like CeO{sub 2} has strong UV absorption and reflection effects, and absorption interval changed significantly by the move to UVA from UVB. - Graphical abstract: Each Ce-atom connects three Cl-atoms and three allyls in three dimensional spaces. To take the plane as a reference plane which is arrayed with three Ce-atom as equilateral triangle. The triangular each vertex is Ce-atom, the triangular center place is Cl-atom, the equilateral triangle which is mutually perpendicular with Ce-triangle surface and the inclined angle is 60° is made up with three Cl-atoms. - Highlights: • Petals-like Ce{sub 2}(CO{sub 3}){sub 3} were synthesized with PAH. • PAH and Ce{sup 3+} form π-allyl complex. • The growth crystal is inhibited on (2 4 2) and promoted on (2 0 2). • CeO{sub 2} absorption interval changed by the move to UVA from UVB.« less

Highly transparent cerium doped gadolinium gallium aluminum garnet ceramic prepared with precursors fabricated by ultrasonic enhanced chemical co-precipitation.

PubMed

Zhang, Ji-Yun; Luo, Zhao-Hua; Jiang, Hao-Chuan; Jiang, Jun; Chen, Chun-Hua; Zhang, Jing-Xian; Gui, Zhen-Zhen; Xiao, Na

2017-11-01

Cerium doped gadolinium gallium aluminum garnet (GGAG:Ce) ceramic precursors have been synthesized with an ultrasonic chemical co-precipitation method (UCC) and for comparison with a traditional chemical co-precipitation method (TCC). The effect of ultra-sonication on the morphology of powders and the transmittance of GGAG:Ce ceramics are studied. The results indicate that the UCC method can effectively improve the homogenization and sinterability of GGAG:Ce powders, which contribute to obtain high transparent GGAG ceramic with the highest transmittance of 81%. Copyright © 2017 Elsevier B.V. All rights reserved.

Improve electrochemical performance of CeO2 surface modification LiNi0.80Co0.15Al0.05O2 cathode material

NASA Astrophysics Data System (ADS)

Xia, Shubiao; Zhang, Yingjie; Dong, Peng; Zhang, Yannan

2014-06-01

Lithium ion battery cathode material LiNi0.8Co0.15Al0.05O2 cathode has successfully prepared by co-precipitation. CeO2 surface modification has improved LiNi0.80Co0.15Al0.05O2 electrochemical performance use sol-gel method and subsequent heat treatment at 600 °C for 5 h. Different to other conventional coating material, CeO2 coating layer can not only inhibit the reaction of the electrode and the electrolyte, but also can reduce the impedance of electron transfer due to its high conductivity, and inhibit the production of Ni2+ because of its high oxidation. The surface-modified and pristine LiNi0.80Co0.15Al0.05O2 powders are characterized by XRD, SEM, TEM, XPS, CV and DSC. When CeO2 coating is 0.02% (mole ratio), contrast to pristine NCA, the CeO2-coated NCA cathode exhibits no decrease in its initial specific capacity of 184 mAh g -1 (at 0.2 C) and excellent capacity retention (86% of its initial capacity at 1 C) between 2.75 and 4.3 V after 100 cycles. The results indicate that the CeO2 surface treatment should be an effective way to improve cycle properties due to CeO2 inhibit the electrodes and the electrolyte side effects.

Effect of collagen and elastin content on the burst pressure of human blood vessel seals formed with a bipolar tissue sealing system.

PubMed

Latimer, Cassandra A; Nelson, Meghan; Moore, Camille M; Martin, Kimberly E

2014-01-01

Bipolar devices are routinely used to seal blood vessels instead of sutures and clips. Recent work examining the impact of vascular proteins on bipolar seal performance found that collagen and elastin (CE) content within porcine arteries was a significant predictor of a vessel's burst pressure (VBPr). This study examined seal performance across a range of human blood vessels to investigate whether a similar relationship existed. In addition, we compared VBPr and CE content between porcine and human blood vessels. Our primary hypothesis is that higher collagen-to-elastin ratio will predict higher VBPr in human vasculature. In six cadavers, 185 blood vessels from nine anatomic locations were sealed using a bipolar electrosurgical system. A linear mixed model framework was used to evaluate the impact of vessel diameter and CE content on VBPr. The effect of CE ratio on VBPr is modified by vessel size, with CE ratio having larger influence on VBPr in smaller diameter vessels. Seal burst pressure of vessels 2-5 mm in diameter was significantly associated with their CE content. Comparison of average VBPr between species revealed porcine carotid and iliac arteries (440-670 mmHg) to be the best vessel types for predicting the seal strength of most human blood vessels (420-570 mmHg) examined. CE content significantly modified the seal strength of small to medium sized blood vessels but had limited impact on vessels >5 mm. Copyright © 2014 Elsevier Inc. All rights reserved.

Pt-Ru/CeO2/carbon nanotube nanocomposites: an efficient electrocatalyst for direct methanol fuel cells.

PubMed

Sun, Zhenyu; Wang, Xiang; Liu, Zhimin; Zhang, Hongye; Yu, Ping; Mao, Lanqun

2010-07-20

Pt-Ru/CeO(2)/multiwalled carbon nanotube (MWNT) electrocatalysts were prepared using a rapid sonication-facilitated deposition method and were characterized by X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), and voltammetry. Morphological characterization by TEM revealed that CeO(2) nanoparticles (NPs) were in intimate contact with Pt-Ru NPs, and both were highly dispersed on the exteriors of nanotubes with a small size and a very narrow size distribution. Compared with the Pt-Ru/MWNT and Pt/MWNT electrocatalysts, the as-prepared Pt-Ru/CeO(2)/MWNT exhibited a significantly improved electrochemically active surface area (ECSA) and a remarkably enhanced activity toward methanol oxidation. The effects of the Pt-Ru loading and the Pt-to-Ru molar ratio on the electrocatalytic activity of Pt-Ru/CeO(2)/MWNT for methanol oxidation were investigated. We found that a maximum activity toward methanol oxidation reached at the 10 wt % of Pt-Ru loading and 1:1 of Pt-to-Ru ratio. Moreover, the role of CeO(2) in the catalysts for the enhancement of methanol oxidation was discussed in terms of both bifunctional mechanism and electronic effects.

Bio-Diesel Production from Deoxygenation Reaction Over Ce0.6Zr0.4O2 Supported Transition Metal (Ni, Cu, Co, and Mo) Catalysts.

PubMed

Shim, Jae-Oh; Jeong, Dae-Woon; Jang, Won-Jun; Jeon, Kyung-Won; Jeon, Byong-Hun; Kim, Seong-Heon; Roh, Hyun-Seog; Na, Jeong-Geol; Han, Sang Sup; Ko, Chang Hyun

2016-05-01

Ce0.6Zr0.4O2 supported transition metal (Me = Ni, Cu, Co, and Mo) catalysts have been investigated to screen for the catalytic activity and selectivity for deoxygenation reaction of oleic acid. Me-Ce0.6Zr0.4O2 catalysts were prepared by a co-precipitation method. Ni-Ce0.6Zr0.4O2 catalyst exhibited much higher oleic acid conversion, selectivity for C9 to C17 compounds, and oxygen removal efficiency than the others. This is mainly ascribed to the presence of free Ni species, synergy effects between Ni and Ce0.6Zr0.4O2, and the highest BET surface area.

Formation of TbCu7-type CeFe10Zr0.8 by rapid solidification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, C; Pinkerton, FE; Herbst, JF

2013-08-25

We report the discovery of a new ternary compound prepared by melt spinning induction melted ingot of nominal composition CeFe11Zr. The sample melt spun at v(s) = 25 m/s exhibits the hexagonal TbCu7-type structure of space group P6/mmm. Through fitting the experimental X-ray diffraction pattern by Rietveld method, we have successfully derived the crystal structure of the new compound melt spun at v(s) = 25 m/s to be CeFe10Zr0.8. Subsequent density function theory calculation fully supports the chemical stability of the new ternary compound. Annealing test showed that the melt spun CeFe10Zr0.8 is stable up to 700 degrees C andmore » annealing at higher temperature would cause it to decompose into hexagonal Ce2Fe17-type structure and ZrFe2. The Curie temperature measurement found that CeFe10Zr0.8 boasts a T-c = 181 degrees C, which is higher than the Tc values of all known Ce-Fe binary compounds, and 30 degrees C higher than that of Ce2Fe14B. These interesting properties stimulate continued search for new Ce-based permanent magnets that could be a cost effective solution to engineering needs in the future. (c) 2013 Elsevier B.V. All rights reserved.« less

High-k 3D-barium titanate foam/phenolphthalein poly(ether sulfone)/cyanate ester composites with frequency-stable dielectric properties and extremely low dielectric loss under reduced concentration of ceramics

NASA Astrophysics Data System (ADS)

Zheng, Longhui; Yuan, Li; Guan, Qingbao; Liang, Guozheng; Gu, Aijuan

2018-01-01

Higher dielectric constant, lower dielectric loss and better frequency stability have been the developing trends for high dielectric constant (high-k) materials. Herein, new composites have been developed through building unique structure by using hyperbranched polysiloxane modified 3D-barium titanate foam (BTF) (BTF@HSi) as the functional fillers and phenolphthalein poly(ether sulfone) (cPES)/cyanate ester (CE) blend as the resin matrix. For BTF@HSi/cPES/CE composite with 34.1 vol% BTF, its dielectric constant at 100 Hz is as high as 162 and dielectric loss is only 0.007; moreover, the dielectric properties of BTF@HSi/cPES/CE composites exhibit excellent frequency stability. To reveal the mechanism behind these attractive performances of BTF@HSi/cPES/CE composites, three kinds of composites (BTF/CE, BTF/cPES/CE, BTF@HSi/CE) were prepared, their structure and integrated performances were intensively investigated and compared with those of BTF@HSi/cPES/CE composites. Results show that the surface modification of BTF is good for preparing composites with improved thermal stability; while introducing flexible cPES to CE is beneficial to fabricate composites with good quality through effectively blocking cracks caused by the stress concentration, and then endowing the composites with good dielectric properties at reduced concentration of ceramics.

The impact of cerium oxide nanoparticles on the physiology of soybean (Glycine max (L.) Merr.) under different soil moisture conditions.

PubMed

Cao, Zhiming; Rossi, Lorenzo; Stowers, Cheyenne; Zhang, Weilan; Lombardini, Leonardo; Ma, Xingmao

2018-01-01

The ongoing global climate change raises concerns over the decreasing moisture content in agricultural soils. Our research investigated the physiological impact of two types of cerium oxide nanoparticles (CeO 2 NPs) on soybean at different moisture content levels. One CeO 2 NP was positively charged on the surface and the other negatively charged due to the polyvinylpyrrolidone (PVP) coating. The results suggest that the effect of CeO 2 NPs on plant photosynthesis and water use efficiency (WUE) was dependent upon the soil moisture content. Both types of CeO 2 NPs exhibited consistently positive impacts on plant photosynthesis at the moisture content above 70% of field capacity (θ fc ). Similar positive impact of CeO 2 NPs was not observed at 55% θ fc , suggesting that the physiological impact of CeO 2 NPs was dependent upon the soil moisture content. The results also revealed that V Cmax (maximum carboxylation rate) was affected by CeO 2 NPs, indicating that CeO 2 NPs affected the Rubisco activity which governs carbon assimilation in photosynthesis. In conclusion, CeO 2 NPs demonstrated significant impacts on the photosynthesis and WUE of soybeans and such impacts were affected by the soil moisture content. Graphical abstract Soil moisture content affects plant cerium oxide nanoparticle interactions.

Confined NaAlH4 nanoparticles inside CeO2 hollow nanotubes towards enhanced hydrogen storage.

PubMed

Gao, Qili; Xia, Guanglin; Yu, Xuebin

2017-10-05

NaAlH 4 has been widely regarded as a potential hydrogen storage material due to its favorable thermodynamics and high energy density. The high activation energy barrier and high dehydrogenation temperature, however, significantly hinder its practical application. In this paper, CeO 2 hollow nanotubes (HNTs) prepared by a simple electrospinning technique are adopted as functional scaffolds to support NaAlH 4 nanoparticles (NPs) towards advanced hydrogen storage performance. The nanoconfined NaAlH 4 inside CeO 2 HNTs, synthesized via the infiltration of molten NaAlH 4 into the CeO 2 HNTs under high hydrogen pressure, exhibited significantly improved dehydrogenation properties compared with both bulk and ball-milled CeO 2 HNTs-catalyzed NaAlH 4 . The onset dehydrogenation temperature of the NaAlH 4 @CeO 2 composite was reduced to below 100 °C, with only one main dehydrogenation peak appearing at 130 °C, which is 120 °C and 50 °C lower than for its bulk counterpart and for the ball-milled CeO 2 HNTs-catalyzed NaAlH 4 , respectively. Moreover, ∼5.09 wt% hydrogen could be released within 30 min at 180 °C, while only 1.6 wt% hydrogen was desorbed from the ball-milled NaAlH 4 under the same conditions. This significant improvement is mainly attributed to the synergistic effects contributed by the CeO 2 HNTs, which could act as not only a structural scaffold to fabricate and confine the NaAlH 4 NPs, but also as an effective catalyst to enhance the hydrogen storage performance of NaAlH 4 .

Human Carboxylesterase 1 Stereoselectively Binds the Nerve Agent Cyclosarin and Spontaneously Hydrolyzes the Nerve Agent Sarin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hemmert, Andrew C.; Otto, Tamara C.; Wierdl, Monika

Organophosphorus (OP) nerve agents are potent toxins that inhibit cholinesterases and produce a rapid and lethal cholinergic crisis. Development of protein-based therapeutics is being pursued with the goal of preventing nerve agent toxicity and protecting against the long-term side effects of these agents. The drug-metabolizing enzyme human carboxylesterase 1 (hCE1) is a candidate protein-based therapeutic because of its similarity in structure and function to the cholinesterase targets of nerve agent poisoning. However, the ability of wild-type hCE1 to process the G-type nerve agents sarin and cyclosarin has not been determined. We report the crystal structure of hCE1 in complex withmore » the nerve agent cyclosarin. We further use stereoselective nerve agent analogs to establish that hCE1 exhibits a 1700- and 2900-fold preference for the P{sub R} enantiomers of analogs of soman and cyclosarin, respectively, and a 5-fold preference for the P{sub S} isomer of a sarin analog. Finally, we show that for enzyme inhibited by racemic mixtures of bona fide nerve agents, hCE1 spontaneously reactivates in the presence of sarin but not soman or cyclosarin. The addition of the neutral oxime 2,3-butanedione monoxime increases the rate of reactivation of hCE1 from sarin inhibition by more than 60-fold but has no effect on reactivation with the other agents examined. Taken together, these data demonstrate that hCE1 is only reactivated after inhibition with the more toxic P{sub S} isomer of sarin. These results provide important insights toward the long-term goal of designing novel forms of hCE1 to act as protein-based therapeutics for nerve agent detoxification.« less

All-in-one light-tunable borated phosphors with chemical and luminescence dynamical control resolution.

PubMed

Lin, Chun Che; Liu, Yun-Ping; Xiao, Zhi Ren; Wang, Yin-Kuo; Cheng, Bing-Ming; Liu, Ru-Shi

2014-06-25

Single-composition white-emitting phosphors with superior intrinsic properties upon excitation by ultraviolet light-emitting diodes are important constituents of next-generation light sources. Borate-based phosphors, such as NaSrBO3:Ce(3+) and NaCaBO3:Ce(3+), have stronger absorptions in the near-ultraviolet region as well as better chemical/physical stability than oxides. Energy transfer effects from sensitizer to activator caused by rare-earth ions are mainly found in the obtained photoluminescence spectra and lifetime. The interactive mechanisms of multiple dopants are ambiguous in most cases. We adjust the doping concentration in NaSrBO3:RE (RE = Ce(3+), Tb(3+), Mn(2+)) to study the energy transfer effects of Ce(3+) to Tb(3+) and Mn(2+) by comparing the experimental data and theoretical calculation. The vacuum-ultraviolet experimental determination of the electronic energy levels for Ce(3+) and Tb(3+) in the borate host regarding the 4f-5d and 4f-4f configurations are described. Evaluation of the Ce(3+)/Mn(2+) intensity ratios as a function of Mn(2+) concentration is based on the analysis of the luminescence dynamical process and fluorescence lifetime measurements. The results closely agree with those directly obtained from the emission spectra. Density functional calculations are performed using the generalized gradient approximation plus an on-site Coulombic interaction correction scheme to investigate the forbidden mechanism of interatomic energy transfer between the NaSrBO3:Ce(3+) and NaSrBO3:Eu(2+) systems. Results indicate that the NaSrBO3:Ce(3+), Tb(3+), and Mn(2+) phosphors can be used as a novel white-emitting component of UV radiation-excited devices.

SCR atmosphere induced reduction of oxidized mercury over CuO-CeO2/TiO2 catalyst.

PubMed

Li, Hailong; Wu, Shaokang; Wu, Chang-Yu; Wang, Jun; Li, Liqing; Shih, Kaimin

2015-06-16

CuO-CeO2/TiO2 (CuCeTi) catalyst synthesized by a sol-gel method was employed to investigate mercury conversion under a selective catalytic reduction (SCR) atmosphere (NO, NH3 plus O2). Neither NO nor NH3 individually exhibited an inhibitive effect on elemental mercury (Hg(0)) conversion in the presence of O2. However, Hg(0) conversion over the CuCeTi catalyst was greatly inhibited under SCR atmosphere. Systematic experiments were designed to investigate the inconsistency and explore the in-depth mechanisms. The results show that the copresence of NO and NH3 induced reduction of oxidized mercury (Hg(2+), HgO in this study), which offset the effect of catalytic Hg(0) oxidation, and hence resulted in deactivation of Hg(0) conversion. High NO and NH3 concentrations with a NO/NH3 ratio of 1.0 facilitated Hg(2+) reduction and therefore lowered Hg(0) conversion. Hg(2+) reduction over the CuCeTi catalyst was proposed to follow two possible mechanisms: (1) direct reaction, in which NO and NH3 react directly with HgO to form N2 and Hg(0); (2) indirect reaction, in which the SCR reaction consumed active surface oxygen on the CuCeTi catalyst, and reduced species on the CuCeTi catalyst surface such as Cu2O and Ce2O3 robbed oxygen from adjacent HgO. Different from the conventionally considered mechanisms, that is, competitive adsorption responsible for deactivation of Hg(0) conversion, this study reveals that oxidized mercury can transform into Hg(0) under SCR atmosphere. Such knowledge is of fundamental importance in developing efficient and economical mercury control technologies for coal-fired power plants.

Nociceptin/orphanin FQ decreases glutamate transmission and blocks ethanol-induced effects in the central amygdala of naive and ethanol-dependent rats.

PubMed

Kallupi, Marsida; Varodayan, Florence P; Oleata, Christopher S; Correia, Diego; Luu, George; Roberto, Marisa

2014-04-01

The central nucleus of the amygdala (CeA) mediates several addiction-related processes and nociceptin/orphanin FQ (nociceptin) regulates ethanol intake and anxiety-like behaviors. Glutamatergic synapses, in the CeA and throughout the brain, are very sensitive to ethanol and contribute to alcohol reinforcement, tolerance, and dependence. Previously, we reported that in the rat CeA, acute and chronic ethanol exposures significantly decrease glutamate transmission by both pre- and postsynaptic actions. In this study, using electrophysiological techniques in an in vitro CeA slice preparation, we investigated the effects of nociceptin on glutamatergic transmission and its interaction with acute ethanol in naive and ethanol-dependent rats. We found that nociceptin (100-1000 nM) diminished basal-evoked compound glutamatergic receptor-mediated excitatory postsynaptic potentials (EPSPs) and spontaneous and miniature EPSCs (s/mEPSCs) by mainly decreasing glutamate release in the CeA of naive rats. Notably, nociceptin blocked the inhibition induced by acute ethanol (44 mM) and ethanol blocked the nociceptin-induced inhibition of evoked EPSPs in CeA neurons of naive rats. In neurons from chronic ethanol-treated (ethanol-dependent) rats, the nociceptin-induced inhibition of evoked EPSP amplitude was not significantly different from that in naive rats. Application of [Nphe1]Nociceptin(1-13)NH2, a nociceptin receptor (NOP) antagonist, revealed tonic inhibitory activity of NOP on evoked CeA glutamatergic transmission only in ethanol-dependent rats. The antagonist also blocked nociceptin-induced decreases in glutamatergic responses, but did not affect ethanol-induced decreases in evoked EPSP amplitude. Taken together, these studies implicate a potential role for the nociceptin system in regulating glutamatergic transmission and a complex interaction with ethanol at CeA glutamatergic synapses.

A daily single dose of a novel modafinil analogue CE-123 improves memory acquisition and memory retrieval.

PubMed

Kristofova, Martina; Aher, Yogesh D; Ilic, Marija; Radoman, Bojana; Kalaba, Predrag; Dragacevic, Vladimir; Aher, Nilima Y; Leban, Johann; Korz, Volker; Zanon, Lisa; Neuhaus, Winfried; Wieder, Marcus; Langer, Thierry; Urban, Ernst; Sitte, Harald H; Hoeger, Harald; Lubec, Gert; Aradska, Jana

2018-05-02

Dopamine reuptake inhibitors have been shown to improve cognitive parameters in various tasks and animal models. We recently reported a series of modafinil analogues, of which the most promising, 5-((benzhydrylsulfinyl)methyl) thiazole (CE-123), was selected for further development. The present study aims to characterize pharmacological properties of CE-123 and to investigate the potential to enhance memory performance in a rat model. In vitro transporter assays were performed in cells expressing human transporters. CE-123 blocked uptake of [3H] dopamine (IC50 = 4.606 μM) while effects on serotonin (SERT) and the norepinephrine transporter (NET) were negligible. Blood-brain barrier and pharmacokinetic studies showed that the compound reached the brain and lower elimination than R-modafinil. The Pro-cognitive effect was evaluated in a spatial hole-board task in male Sprague-Dawley rats and CE-123 enhances memory acquisition and memory retrieval, represented by significantly increased reference memory indices and shortened latency. Since DAT blockers can be considered as indirect dopamine receptor agonists, western blotting was used to quantify protein levels of dopamine receptors D1R, D2R and D5R and DAT in the synaptosomal fraction of hippocampal subregions CA1, CA3 and dentate gyrus (DG). CE-123 administration in rats increased total DAT levels and D1R protein levels were significantly increased in CA1 and CA3 in treated/trained groups. The increase of D5R was observed in DG only. Dopamine receptors, particularly D1R, seem to play a role in mediating CE-123-induced memory enhancement. Dopamine reuptake inhibition by CE-123 may represent a novel and improved stimulant therapeutic for impairments of cognitive functions. Copyright © 2018 Elsevier B.V. All rights reserved.

[Oxidation behavior and kinetics of representative VOCs emitted from petrochemical industry over CuCeOx composite oxides].

PubMed

Chen, Chang-Wei; Yu, Yan-Ke; Chen, Jin-Sheng; He, Chi

2013-12-01

CuCeOx composite catalysts were synthesized via coprecipitation (COP-CuCeO,) and incipient impregnation (IMP-CuCeOx) methods, respectively. The physicochemical properties of the samples were characterized by XRD, low-temperature N2 sorption, H2-TPR and O2-TPD. The influences of reactant composition and concentration, reaction space velocity, O2 content, H2O concentration, and catalyst type on the oxidation behaviors of benzene, toluene, and n-hexane emitted from petrochemical industry were systematically investigated. In addition, the related kinetic parameters were model fitted. Compared with IMP-CuCeOx, COP-CuCeOx had well-dispersed active phase, better low-temperature reducibility, and more active surface oxygen species. The increase of reactant concentration was unfavorable for toluene oxidation, while the opposite phenomenon could be observed in n-hexane oxidation. The inlet concentration of benzene was irrelevant to its conversion under high oxidation rate. The introduction of benzene obviously inhibited the oxidation of toluene and n-hexane, while the presence of toluene had a positive effect on beuzene conversion. The presence of n-hexane could promote the oxidation of toluene, while toluene had a negative influence on e-hexane oxidation. Both low space velocity and high oxygen concentration were beneficial for the oxidation process, and the variation of oxygen content had negligible effect on n-hexane and henzene oxidation. The presence of H2O noticeably inhibited the oxidation of toluene, while significantly accelerated the oxidation procedure of henzene and n-hexane. COP-CuCeOx had superior catalytic performance for toluene and benzene oxidation, while IMP-CuCeOx showed higher n-hexane oxidation activity under dry condition. The oxidation behaviors under different conditions could be well fitted and predicted by the pseudo first-order kinetic model.

Ce, Ti modified MCM-48 mesoporous photocatalysts: Effect of the synthesis route on support and metal ion properties

NASA Astrophysics Data System (ADS)

Mureseanu, Mihaela; Filip, Mihaela; Somacescu, Simona; Baran, Adriana; Carja, Gabriela; Parvulescu, Viorica

2018-06-01

New Ti-MCM-48 and CeTi-MCM-48 photocatalysts were obtained by impregnation of the MCM-48 silica support synthesized by a hydrothermal process with aqueous solution of Ti and Ce precursors. The immobilization of metal cations presented a low effect on the porosity, morphology and structure of MCM-48 mesoporous silica support as was evidenced by N2 adsorption-desorption, X-ray diffraction, SEM and TEM electron microscopy. EDAX analysis and X-ray photoelectron microscopy (XPS) indicated that titanium cations were present on the mesoporous silica surface only as Ti4+ species and the effect of ceria on titanium speciation was different, compared to the CeTi-MCM-48 sample, previously obtained by direct synthesis. The photocatalytic properties of mono- and bimetallic catalysts were evaluated in degradation of phenol from water and correlated with the active metallic species concentration, distribution, speciation and their interaction with the support or each other. An advanced oxidation mechanism for phenol degradation by radical species was proposed.

Effect of variable cerium concentration on photoluminescence behaviour in ZrO2 phosphor synthesized by combustion synthesis method

NASA Astrophysics Data System (ADS)

Dubey, Vikas; Kaur, Jagjeet

2016-05-01

Present paper reports synthesis and characterization of trivalent cerium (Ce3+) doped zirconium dioxide (ZrO2) phosphors. Effect of variable concentration of cerium on photoluminescence (PL) is studied. Samples were prepared by combustion synthesis technique which is suitable for less time taking techniques also for large scale production for phosphors. Starting material used for sample preparation are Zr(NO3)3 and Ce(NO3)3 and urea used as a fuel. All prepared phosphor with variable concentration of Ce3+ (0.1 to 2mol%) was studied by photoluminescence analysis it is found that the excitation spectra of prepared phosphor shows broad excitation centred at 390nm. The excitation spectra with variable concentration of Ce3+ show strong peaks at 447nm. Spectrophotometric determinations of peaks are evaluated by Commission Internationale de I'Eclairage technique. Using this phosphor, the desired CIE values including emissions throughout the violet (390 nm) and blue (427 nm) of the spectra were achieved. Efficient blue light emitting diodes were fabricated using Ce3+ doped phosphor based on near ultraviolet (NUV) excited LED lights.

Ce(3+) /Tb(3+) non-/single-/co-doped K-Lu-F materials: synthesis, optical properties, and energy transfer.

PubMed

Cao, Chunyan; Xie, An; Noh, Hyeon Mi; Jeong, Jung Hyun

2016-08-01

Using a hydrothermal method, Ce(3+) /Tb(3+) non-/single-/co-doped K-Lu-F materials have been synthesized. The X-ray diffraction (XRD) results suggest that the Ce(3+) and/or Tb(3+) doping had great effects on the crystalline phases of the final samples. The field emission scanning electron microscopy (FE-SEM) images indicated that the samples were in hexagonal disk or polyhedron morphologies in addition to some nanoparticles, which also indicated that the doping also had great effects on the sizes and the morphologies of the samples. The energy-dispersive spectroscopy (EDS) patterns illustrated the constituents of different samples. The enhanced emissions of Tb(3+) were observed in the Ce(3+) /Tb(3+) co-doped K-Lu-F materials. The energy transfer (ET) efficiency ηT were calculated based on the fluorescence yield. The ET mechanism from Ce(3+) to Tb(3+) was confirmed to be the dipole-quadrupole interaction inferred from the theoretical analysis and the experimental data. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Magnetic and electronic properties of Nd--La and Ce--La alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petersen, T.S.

1979-05-01

The electrical resistivity, thermoelectric power and magnetic susceptibility on Nd single crystals and polycrystalline dhcp Nd--La and Ce--La alloys have been measured at low temperatures. The measurements on the Nd--La alloys show features at the Neel temperatures and also show additional magnetic ordering phenomena. Some of these other features are dependent on the thermal history of the sample. Magnetic field studies are needed to correlate these features with observed neutron diffraction effects. Several magnetic features are seen in the Ce--La alloy system also, although the measurements are plagued with the problem of fcc contamination. In addition, alloys containing Ce showmore » Kondo effects. The logarithmic term in the resistivity is explained well by the theory of Liu et al. which uses a mean field to approximate the 4f-4f interactions in the nondilute alloys. The large peak in the thermopower of Ce--La alloys is explained well by the theory of Bhattacharjee and Coqblin which incorporates Kondo scattering from excited crystal field levels.« less

Verification of the antidiabetic effects of cinnamon (Cinnamomum zeylanicum) using insulin-uncontrolled type 1 diabetic rats and cultured adipocytes.

PubMed

Shen, Yan; Fukushima, Misato; Ito, Yoshimasa; Muraki, Etsuko; Hosono, Takashi; Seki, Taiichiro; Ariga, Toyohiko

2010-01-01

It has long been believed that an intake of cinnamon (Cinnamomum zeylanicum) alleviates diabetic pathological conditions. However, it is still controversial whether the beneficial effect is insulin-dependent or insulin-mimetic. This study was aimed at determining the insulin-independent effect of cinnamon. Streptozotocin-induced diabetic rats were divided into four groups and orally administered with an aqueous cinnamon extract (CE) for 22 d. The diabetic rats that had taken CE at a dose of more than 30 mg/kg/d were rescued from their hyperglycemia and nephropathy, and these rats were found to have upregulation of uncoupling protein-1 (UCP-1) and glucose transporter 4 (GLUT4) in their brown adipose tissues as well as in their muscles. This was verified by using 3T3-L1 adipocytes in which CE upregulates GLUT4 translocation and increases the glucose uptake. CE exhibited its anti-diabetic effect independently from insulin by at least two mechanisms: i) upregulation of mitochondrial UCP-1, and ii) enhanced translocation of GLUT4 in the muscle and adipose tissues.

The NH2 terminus regulates voltage-dependent gating of CALHM ion channels.

PubMed

Tanis, Jessica E; Ma, Zhongming; Foskett, J Kevin

2017-08-01

Calcium homeostasis modulator protein-1 (CALHM1) and its Caenorhabditis elegans (ce) homolog, CLHM-1, belong to a new family of physiologically important ion channels that are regulated by voltage and extracellular Ca 2+ (Ca 2+ o ) but lack a canonical voltage-sensing domain. Consequently, the intrinsic voltage-dependent gating mechanisms for CALHM channels are unknown. Here, we performed voltage-clamp experiments on ceCLHM-1 chimeric, deletion, insertion, and point mutants to assess the role of the NH 2 terminus (NT) in CALHM channel gating. Analyses of chimeric channels in which the ceCLHM-1 and human (h)CALHM1 NH 2 termini were interchanged showed that the hCALHM1 NT destabilized channel-closed states, whereas the ceCLHM-1 NT had a stabilizing effect. In the absence of Ca 2+ o , deletion of up to eight amino acids from the ceCLHM-1 NT caused a hyperpolarizing shift in the conductance-voltage relationship with little effect on voltage-dependent slope. However, deletion of nine or more amino acids decreased voltage dependence and induced a residual conductance at hyperpolarized voltages. Insertion of amino acids into the NH 2 -terminal helix also decreased voltage dependence but did not prevent channel closure. Mutation of ceCLHM-1 valine 9 and glutamine 13 altered half-maximal activation and voltage dependence, respectively, in 0 Ca 2+ In 2 mM Ca 2+ o , ceCLHM-1 NH 2 -terminal deletion and point mutant channels closed completely at hyperpolarized voltages with apparent affinity for Ca 2+ o indistinguishable from wild-type ceCLHM-1, although the ceCLHM-1 valine 9 mutant exhibited an altered conductance-voltage relationship and kinetics. We conclude that the NT plays critical roles modulating voltage dependence and stabilizing the closed states of CALHM channels. Copyright © 2017 the American Physiological Society.

Effect of Saccharomyces boulardii in dog with chronic enteropathies: double-blinded, placebo-controlled study.

PubMed

D'Angelo, Simona; Fracassi, Federico; Bresciani, Francesca; Galuppi, Roberta; Diana, Alessia; Linta, Nikolina; Bettini, Giuliano; Morini, Maria; Pietra, Marco

2018-03-03

Saccharomyces boulardii is used to treat acute and chronic enteropathies in humans, but to date, no studies have evaluated the use of this yeast in dogs. The current study, a prospective non-randomised, double-blinded, placebo-controlled study, evaluated the effects of S boulardii in healthy dogs and dogs with chronic enteropathies (CE). Four healthy dogs and 20 dogs with CE were included. In healthy dogs, S boulardii was administered for 10 days. Possible short-term adverse effects were recorded, and quantitative stool cultures for yeasts were performed. In dogs with CE, S boulardii or a placebo was administered in addition to standard treatment protocols. Canine Chronic Enteropathy Clinical Activity Index, abdominal ultrasonography, gastroenteroscopy and histology were performed at the time of diagnosis and after 60 days of treatment. In healthy dogs, S boulardii reached a steady state in five days and was completely eliminated on day 4 after administration. No short-term side effects were seen. Clinical activity index, stool frequency, stool consistency and body condition score improved significantly in dogs with CE receiving S boulardii versus the placebo. In conclusion, S boulardii can be safely used in dogs with CE and seems to achieve better control of clinical signs than standard therapy alone. © British Veterinary Association (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Nanoparticles formulation of Cuscuta chinensis prevents acetaminophen-induced hepatotoxicity in rats.

PubMed

Yen, Feng-Lin; Wu, Tzu-Hui; Lin, Liang-Tzung; Cham, Thau-Ming; Lin, Chun-Ching

2008-05-01

Cuscuta chinensis is a commonly used traditional Chinese medicine to nourish the liver and kidney. Due to the poor water solubility of its major constituents such as flavonoids and lignans, its absorption upon oral administration could be limited. The purpose of the present study was to use the nanosuspension method to prepare C. chinensis nanoparticles (CN), and to compare the hepatoprotective and antioxidant effects of C. chinensis ethanolic extract (CE) and CN on acetaminophen-induced hepatotoxicity in rats. An oral dose of CE at 125 and 250 mg/kg and CN at 25 and 50mg/kg showed a significant hepatoprotective effect relatively to the same extent (P<0.05) by reducing levels of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. These biochemical assessments were supported by rat hepatic biopsy examinations. In addition, the antioxidant activities of CE and CN both significantly increased superoxide dismutase, catalase, glutathione peroxidase, and reduced malondialdehyde (P<0.05). Moreover, the results also indicated that the hepatoprotective and antioxidant effects of 50 mg/kg CN was effectively better than 125 mg/kg CE (P<0.05), and an oral dose of CN that is five times as less as CE could exhibit similar levels of outcomes. In conclusion, we suggest that the nanoparticles system can be applied to overcome other water poorly soluble herbal medicines and furthermore to decrease the treatment dosage.

Crystal Structures of Human Carboxylesterase 1 in Covalent Complexes with the Chemical Warfare Agents Soman and Tabun†,‡

PubMed Central

Fleming, Christopher D.; Edwards, Carol C.; Kirby, Stephen D.; Maxwell, Donald M.; Potter, Philip M.; Cerasoli, Douglas M.; Redinbo, Matthew R.

2008-01-01

The organophosphorus nerve agents sarin, soman, tabun, and VX exert their toxic effects by inhibiting the action of human acetylcholinesterase, a member of the serine hydrolase superfamily of enzymes. The current treatments for nerve agent exposure must be administered quickly to be effective and they often do not eliminate long-term toxic side effects associated with organophosphate poisoning. Thus, there is significant need for effective prophylactic methods to protect at-risk personnel from nerve agent exposure, and protein-based approaches have emerged as promising candidates. We present the 2.7 Å resolution crystal structures of the serine hydrolase human carboxylesterase 1 (hCE1), a broad-spectrum drug metabolism enzyme, in covalent acyl-enzyme intermediate complexes with the chemical weapons soman and tabun. The structures reveal that hCE1 binds stereoselectively to these nerve agents; for example, hCE1 appears to react preferentially with the 104-fold more lethal PS stereoisomer of soman relative to the PR form. In addition, structural features of the hCE1 active site indicate that the enzyme may be resistant to dead-end organophosphate aging reactions that permanently inactivate other serine hydrolases. Taken together, these data provide important structural details toward the goal of engineering hCE1 into an organophosphate hydrolase and protein-based therapeutic for nerve agent exposure. PMID:17407327

Rare earth, major and trace element composition of Leg 127 sediments

USGS Publications Warehouse

Murray, R.W.; Buchholtz ten Brink, Marilyn R.; Brumsack, Hans-Juergen; Gerlach, David C.; Russ III, G. Price

1992-01-01

The relative effects of paleoceanographic and paleogeographic variations, sediment lithology, and diagenetic processes on the final preserved chemistry of Japan Sea sediments are evaluated by investigating the rare earth element (REE), major element, and trace element concentrations in 59 squeeze-cake whole-round and 27 physical-property sample residues from Sites 794, 795, and 797, cored during ODP Leg 127. The most important variation in sedimentary chemical composition is the increase in SiO2 concentration through the Pliocene diatomaceous sequences, which dilutes most other major and trace element components by various degrees. This biogenic input is largest at Site 794 (Yamato Basin), moderately developed at Site 797 (Yamato Basin), and of only minor importance at Site 795 (Japan Basin), potentially reflecting basinal contrasts in productivity with the Yamato Basin recording greater biogenic input than the Japan Basin and with the easternmost sequence of Site 794 lying beneath the most productive waters. There are few systematic changes in solid-phase chemistry resulting from the opal-A/opal-CT or opal-CT/quartz silica phase transformations. Most major and trace element concentrations are controlled by the aluminosilicate fraction of the sediment, although the effects of diagenetic silica phases and manganese carbonates are of localized importance. REE total abundances (IREE) in the Japan Sea are strongly dependent upon the paleoceanographic position of a given site with respect to terrigenous and biogenic sources. REE concentrations at Site 794 overall correspond well to aluminosilicate chemical indices and are strongly diluted by SiO2 within the upper Miocene-Pliocene diatomaceous sequence. Eu/Eu* values at Site 794 reach a maximum through the diatomaceous interval as well, most likely suggesting an association of Eu/Eu* with the siliceous component, or reflecting slight incorporation of a detrital feldspar phase. XREE at Site 795 also is affiliated strongly with aluminosilicate phases and yet is diluted only slightly by siliceous input. At Site 797, ΣRE E is not as clearly associated with the aluminosilicate fraction, is correlated moderately to siliceous input, and may be sporadically influenced by detrital heavy minerals originating from the nearby rifted continental fragment composing the Yamato Rise. Ce/Ce* profiles at all three sites increase essentially monotonically with depth and record progressive diagenetic LREE fractionation. The observed Ce/Ce* increases are not responding to changes in the paleoceanographic oxygenation state of the overlying water, as there is no independent evidence to suggest the proper Oceanographic conditions. Ce/Ce* correlates slightly better with depth than with age at the two Yamato Basin sites. The downhole increase in Ce/Ce* at Sites 794 and 797 is a passive response to the diagenetic transfer of LREE (except Ce) from sediment to interstitial water. At Site 795, the overall lack of correlation between Ce/Ce* and La/Y^ suggests that other processes mask the diagenetic behavior of all LREEs. First-order calculations of the Ce budget in Japan Sea waters and sediment indicate that ~20% of the excess Ce adsorbed by settling particles is recycled within the water column and that an additional -38% is recycled at or near the seafloor. Thus, because the remaining excess Ce is only -10% of the total Ce, there is not a large source of Ce to the deeply buried sediment, further suggesting that the downhole increase in Ce/Ce* is a passive response to diagenetic behavior of the other LREEs. The REE chemistry of Japan Sea sediment therefore predicts successive downhole addition of LREEs to deeply buried interstitial waters.

Thermoelectric properties of Zn4Sb3/CeFe(4-x)CoxSb12 nano-layered superlattices modified by MeV Si ion beam

NASA Astrophysics Data System (ADS)

Budak, S.; Guner, S.; Minamisawa, R. A.; Muntele, C. I.; Ila, D.

2014-08-01

We prepared multilayers of superlattice thin film system with 50 periodic alternating nano-layers of semiconducting half-Heusler β-Zn4Sb3 and skutterudite CeFe2Co2Sb12 compound thin films using ion beam assisted deposition (IBAD) with Au layers deposited on both sides as metal contacts. The deposited multilayer thin films have alternating layers about 5 nm thick. The total thickness of the multilayer system is 275 nm. The superlattices were then bombarded by 5 MeV Si ion at six different fluences to form nano-cluster structures. The film thicknesses and composition were monitored by Rutherford backscattering spectrometry (RBS) before and after MeV ion bombardment. We have measured the thermoelectric efficiency, Figure of Merit ZT, of the fabricated device by measuring the cross plane thermal conductivity by the 3rd harmonic (3ω) method, the cross plane Seebeck coefficient, and the electrical conductivity using the van der Pauw method before and after the MeV ion bombardments. We reached the remarkable thermoelectric Figure of Merit results at optimal fluences.

Overview of methods in economic analyses of behavioral interventions to promote oral health

PubMed Central

O’Connell, Joan M.; Griffin, Susan

2016-01-01

Background Broad adoption of interventions that prove effective in randomized clinical trials or comparative effectiveness research may depend to a great extent on their costs and cost-effectiveness (CE). Many studies of behavioral health interventions for oral health promotion and disease prevention lack robust economic assessments of costs and CE. Objective To describe methodologies employed to assess intervention costs, potential savings, net costs, CE, and the financial sustainability of behavioral health interventions to promote oral health. Methods We provide an overview of terminology and strategies for conducting economic evaluations of behavioral interventions to improve oral health based on the recommendations of the Panel of Cost-Effectiveness in Health and Medicine. To illustrate these approaches, we summarize methodologies and findings from a limited number of published studies. The strategies include methods for assessing intervention costs, potential savings, net costs, CE, and financial sustainability from various perspectives (e.g., health-care provider, health system, health payer, employer, society). Statistical methods for estimating short-term and long-term economic outcomes and for examining the sensitivity of economic outcomes to cost parameters are described. Discussion Through the use of established protocols for evaluating costs and savings, it is possible to assess and compare intervention costs, net costs, CE, and financial sustainability. The addition of economic outcomes to outcomes reflecting effectiveness, appropriateness, acceptability, and organizational sustainability strengthens evaluations of oral health interventions and increases the potential that those found to be successful in research settings will be disseminated more broadly. PMID:21656966

Overview of methods in economic analyses of behavioral interventions to promote oral health.

PubMed

O'Connell, Joan M; Griffin, Susan

2011-01-01

Broad adoption of interventions that prove effective in randomized clinical trials or comparative effectiveness research may depend to a great extent on their costs and cost-effectiveness (CE). Many studies of behavioral health interventions for oral health promotion and disease prevention lack robust economic assessments of costs and CE. To describe methodologies employed to assess intervention costs, potential savings, net costs, CE, and the financial sustainability of behavioral health interventions to promote oral health. We provide an overview of terminology and strategies for conducting economic evaluations of behavioral interventions to improve oral health based on the recommendations of the Panel of Cost-Effectiveness in Health and Medicine. To illustrate these approaches, we summarize methodologies and findings from a limited number of published studies. The strategies include methods for assessing intervention costs, potential savings, net costs, CE, and financial sustainability from various perspectives (e.g., health-care provider, health system, health payer, employer, society). Statistical methods for estimating short-term and long-term economic outcomes and for examining the sensitivity of economic outcomes to cost parameters are described. Through the use of established protocols for evaluating costs and savings, it is possible to assess and compare intervention costs, net costs, CE, and financial sustainability. The addition of economic outcomes to outcomes reflecting effectiveness, appropriateness, acceptability, and organizational sustainability strengthens evaluations of oral health interventions and increases the potential that those found to be successful in research settings will be disseminated more broadly.

808 nm-excited upconversion nanoprobes with low heating effect for targeted magnetic resonance imaging and high-efficacy photodynamic therapy in HER2-overexpressed breast cancer.

PubMed

Zeng, Leyong; Pan, Yuanwei; Zou, Ruifen; Zhang, Jinchao; Tian, Ying; Teng, Zhaogang; Wang, Shouju; Ren, Wenzhi; Xiao, Xueshan; Zhang, Jichao; Zhang, Lili; Li, Aiguo; Lu, Guangming; Wu, Aiguo

2016-10-01

To avoid the overheating effect of excitation light and improve the efficacy of photodynamic therapy (PDT) of upconversion nanoplatform, a novel nanoprobe based on 808 nm-excited upconversion nanocomposites (T-UCNPs@Ce6@mSiO2) with low heating effect and deep penetration has been successfully constructed for targeted upconversion luminescence, magnetic resonance imaging (MRI) and high-efficacy PDT in HER2-overexpressed breast cancer. In this nanocomposite, photosensitizers (Ce6) were covalently conjugated inside of mesoporous silica to enhance the PDT efficacy by shortening the distance of fluorescence resonance energy transfer and to decrease the cytotoxicity by preventing the undesired leakage of Ce6. Compared with UCNPs@mSiO2@Ce6, UCNPs@Ce6@mSiO2 greatly promoted the singlet oxygen generation and amplified the PDT efficacy under the excitation of 808 nm laser. Importantly, the designed nanoprobe can greatly improve the uptake of HER2-positive cells and tumors by modifying the site-specific peptide, and the in vivo experiments showed excellent MRI and PDT via intravenous injection by modeling MDA-MB-435 tumor-bearing nude mice. Our strategy may provide an effective solution for overcoming the heating effect and improving the PDT efficacy of upconversion nanoprobes, and has potential application in visualized theranostics of HER2-overexpressed breast cancer. Copyright © 2016 Elsevier Ltd. All rights reserved.

A community-based study to examine the epidemiology of human cystic echinococcosis in Rio Negro Province, Argentina.

PubMed

Bingham, Glenda M; Budke, Christine M; Larrieu, Edmundo; Del Carpio, Mario; Mujica, Guillermo; Slater, Margaret R; Moguillansky, Sergio

2014-08-01

Although cystic echinococcosis (CE) is an important public health problem in Rio Negro Province, current epidemiological data for CE, in this region of Argentina, are not available. Therefore, a community-based study, which incorporated diagnostic imaging and a questionnaire, was conducted in Ingeniero Jacobacci, a small town in southern Rio Negro Province. This study sought to assess the prevalence of human CE, in the study population, and to evaluate epidemiologic factors associated with CE transmission within the study area. Of the 560 individuals who volunteered to participate in the study, 189 (34%) were children and 371 (66%) were adults. All study participants were screened for CE using abdominal ultrasound scanning, with CE-positive or suspect individuals also receiving thoracic radiographs. The overall prevalence of CE was 7.1% (40/560), with 1.6% (3/189) of children, and 10% (37/371) of adults diagnosed as CE-positive. Although 92.5% (37/40) of the CE-positive individuals had only hepatic lesions, two participants had both hepatic and pulmonary lesions, and one participant had a single renal lesion. Approximately 92% (340/371) of the adult study participants completed the questionnaire, which was used to identify factors associated with an increased risk for human infection. Age, level of education, dog ownership, and contact with sheep were found to be significantly associated with CE status. This study demonstrated that CE continues to be highly endemic in this region of Rio Negro Province, Argentina. In addition, community-based ultrasound screening surveys are a noninvasive, effective approach to case detection at the community level. Copyright © 2014 Elsevier B.V. All rights reserved.

Design, synthesis, and structure-activity relationship study of glycyrrhetinic acid derivatives as potent and selective inhibitors against human carboxylesterase 2.

PubMed

Zou, Li-Wei; Li, Yao-Guang; Wang, Ping; Zhou, Kun; Hou, Jie; Jin, Qiang; Hao, Da-Cheng; Ge, Guang-Bo; Yang, Ling

2016-04-13

Human carboxylesterase 2 (hCE2), one of the major carboxylesterases in the human intestine and various tumour tissues, plays important roles in the oral bioavailability and treatment outcomes of ester- or amide-containing drugs or prodrugs, such as anticancer agents CPT-11 (irinotecan) and LY2334737 (gemcitabine). In this study, 18β-glycyrrhetinic acid (GA), the most abundant pentacyclic triterpenoid from natural source, was selected as a reference compound for the development of potent and specific inhibitors against hCE2. Simple semi-synthetic modulation on GA was performed to obtain a series of GA derivatives. Structure-activity relationship analysis brought novel insights into the structure modification of GA. Converting the 11-oxo-12-ene of GA to 12-diene moiety, and C-3 hydroxyl and C-30 carboxyl group to 3-O-β-carboxypropionyl and ethyl ester respectively, led to a significant enhancement of the inhibitory effect on hCE2 and the selectivity over hCE1. These exciting findings inspired us to design and synthesize the more potent compound 15 (IC50 0.02 μM) as a novel and highly selective inhibitor against hCE2, which was 3463-fold more potent than the parent compound GA and demonstrated excellent selectivity (>1000-fold over hCE1). The molecular docking study of compound 15 and the active site of hCE1 and hCE2 demonstrated that the potent and selective inhibition of compound 15 toward hCE2 could partially be attributed to its relatively stronger interactions with hCE2 than with hCE1. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Photoluminescence properties of Tb3Al5O12:Ce3+ garnet synthesized by the metal organic decomposition method

NASA Astrophysics Data System (ADS)

Onishi, Yuya; Nakamura, Toshihiro; Adachi, Sadao

2017-02-01

Tb3Al5O12:Ce3+ garnet (TAG:Ce3+) phosphor was synthesized by the metal organic decomposition (MOD) method and subsequent calcination at Tc = 800-1200°C for 1 h in air. The effects of Ce3+ concentration on the phosphor properties were investigated in detail using X-ray diffraction (XRD) analysis, photoluminescence (PL) analysis, PL excitation (PLE) spectroscopy, and PL decay measurements. The maximum intensity in the Ce3+ yellow emission was observed at the Ce3+ concentration of ∼0.20%. PLE and PL decay measurements suggested an evidence of the energy transfer from Tb3+ to Ce3+. Calcination temperature dependence of the XRD and PL intensities yielded an energy of ∼1.5 eV both for the TAG formation in the MOD process and for the optical activation of Ce3+ in its lattice sites. Temperature dependences of the PL intensity for the TAG:Ce3+ yellow-emitting and K2SiF6:Mn4+ red-emitting phosphors were also examined for the future solid-state lighting applications at T = 20-500 K in 10-K steps. The data of TAG:Ce3+ were analyzed using a theoretical model with considering a reservoir level of Et ∼9 meV, yielding a quenching energy of Eq ∼0.35 eV, whereas the K2SiF6:Mn4+ red-emitting phosphor data yielded a value of Eq ∼1.0 eV. The schematic energy-level diagrams for Tb3+ and Ce3+ were proposed for the sake of a better understanding of these ions in the TAG host.

Parvalbumin Interneurons of Central Amygdala Regulate the Negative Affective States and the Expression of Corticotrophin-Releasing Hormone During Morphine Withdrawal

PubMed Central

Wang, Li; Shen, Minjie; Jiang, Changyou

2016-01-01

Background: The central nucleus of the amygdala (CeA) is a crucial component of the neuronal circuitry mediating aversive emotion. Its role in the negative affective states during drug withdrawal includes changes in opioidergic, GABAergic, and corticotropin-releasing factor neurotransmission. However, the modulation of the neurobiological interconnectivity in the CeA and its effects in the negative reinforcement of drug dependents are poorly understood. Method: We performed electrophysiological recordings to assess the membrane excitability of parvalbumin (PV)+ interneurons in the CeA during chronic morphine withdrawal. We tested the morphine withdrawal–induced negative affective states, such as the aversive (assessed by conditioned place aversion), anxiety (assessed by elevated plus maze), and anhedonic-like (assessed by saccharin preference test) behaviors, as well as the mRNA level of corticotropin-releasing hormone (CRH) via optogenetic inhibition or activation of PV+ interneurons in the CeA. Result: Chronic morphine withdrawal increased the firing rate of CeA PV+ interneurons. Optogenetic inhibition of the activity of CeA PV+ interneurons attenuated the morphine withdrawal–induced negative affective states, such as the aversive, anxiety, and anhedonic-like behaviors, while direct activation of CeA PV+ interneurons could trigger those negative affective-like behaviors. Optogenetic inhibition of the CeA PV+ interneurons during the morphine withdrawal significantly attenuated the elevated CRH mRNA level in the CeA. Conclusion: The activity of PV+ interneurons in the CeA was up-regulated during chronic morphine withdrawal. The activation of PV+ interneurons during morphine withdrawal was crucial for the induction of the negative emotion and the up-regulation of CRH mRNA levels in the CeA. PMID:27385383

Factors Influencing Participation in Continuing Professional Development: A Focus on Motivation Among Pharmacists.

PubMed

Tjin A Tsoi, Sharon L N M; de Boer, Anthonius; Croiset, Gerda; Koster, Andries S; Kusurkar, Rashmi A

2016-01-01

The interest in continuing education (CE) for pharmacists has increased because of patient safety issues, advancing science and the quick changes in the profession. Therefore, contemporary pharmaceutical care requires an effective and sustainable system for pharmacists to maintain and improve competencies. Although motivation plays an important role both as a facilitator (desire to learn) and a barrier (lack of motivation), there is little investigated about this specific factor. The aim of the study was to explore what factors influence pharmacists' participation in CE with a focus on motivation. The theoretical framework was self-determination theory (SDT), which describes autonomous motivation (AM) representing motivation from an internal locus of causality, controlled motivation (CM) originating from an external locus of causality, and relative autonomous motivation (RAM) that measures the AM in an individual after correcting for the CM. The relationship between pharmacists' characteristics, especially their motivation (AM, CM and RAM) in CE, and their participation in CE activities was explored using the AMS-questionnaire and the Dutch online portfolio system. RAM was positively correlated with CE participation of pharmacists and explained 7.8% of the variance. The correlations between the independent variables AM and CM and CE hours were negative (-0.301 and -0.476, respectively). Other factors influencing CE participation were pharmacy school (6.8%), traineeship (10.9%), and work experience (7.8%). Pharmacists participated for 27.0 hours on average in CE during 11 months and preferred face-to-face-learning (85.5%) above e-learning (13.8%). Our findings show a positive relationship between RAM and CE participation. The current CE system is probably not conducive to stimulation of AM. Further research is needed to understand the factors that stimulate pharmacists' motivation and participation in CE.

Adsorption behavior of lead on aquatic sediments contaminated with cerium dioxide nanoparticles.

PubMed

Wang, Chao; Fan, Xiulei; Wang, Peifang; Hou, Jun; Ao, Yanhui; Miao, Lingzhan

2016-12-01

Aquatic sediments serve as an important sink for engineered nanomaterials (ENMs), such as metal oxide nanoparticles (MeO NPs) and carbon nanotubes (CNTs). Owing to their remarkable properties, ENMs demonstrate significant potential to disturb the adsorption behavior of other contaminants in aquatic sediments, thereby altering the bioavailability and toxicity of these contaminants. Thus far, most studies have investigated the effect of CNTs on the adsorption of other contaminants on sediments. Cerium dioxide nanoparticles (CeO 2 NPs), as one of the important MeO NPs, are also inevitably discharged into aquatic sediments because of their widespread use. In this study, we investigated the adsorption behavior of Pb 2+ on sediments spiked with CeO 2 NPs at a weight ratio of 5.0%. The results showed that the adsorption rates at three stages occurring during adsorption clearly increase for sediments contaminated with CeO 2 NPs. Moreover, the results obtained from the adsorption isotherms indicated that the Langmuir isotherm model best fits the isotherm data for both sediments and those contaminated with CeO 2 NPs. After spiking the sediments with CeO 2 NPs, the theoretical maximum monolayer adsorption capacity (Q max ) for Pb 2+ increased from 4.433 to 4.995 mg/g and the Langmuir isotherm coefficient (K L ) decreased from 8.813 to 7.730 L/g. The effects of CeO 2 NPs on the surface charge and pore surface properties of sediments were also studied as these properties affect the adsorption of several chemicals in sediments. The results showed that pH zpc , S BET , S ext , and average pore size of sediments clearly decrease for sediments contaminated with CeO 2 NPs. Hence, the strong adsorption capacity of CeO 2 NPs and the changes of sediment surface charge and pore surface properties caused by CeO 2 NPs are important factors affecting the adsorption behavior of Pb 2+ . The potential risk of Pb 2+ in aquatic environment may increase with CeO 2 NPs buried in sediments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of Ga3+ and Gd3+ ions substitution on the structural and optical properties of Ce3+ -doped yttrium aluminium garnet phosphor nanopowders.

PubMed

Wako, A H; Dejene, F B; Swart, H C

2016-11-01

The structural and optical properties of commercially obtained Y 3 Al 5 O 12 :Ce 3 + phosphor were investigated by replacing Al 3 + with Ga 3 + and Y 3 + with Gd 3 + in the Y 3 Al 5 O 12 :Ce 3 + structure to form Y 3 (Al,Ga) 5 O 12 :Ce 3 + and (Y,Gd) 3 Al 5 O 12 :Ce 3 + . X-Ray diffraction (XRD) results showed slight 2-theta peak shifts to lower angles when Ga 3 + was used and to higher angles when Gd 3 + was used, with respect to peaks from Y 3 Al 5 O 12 :Ce 3 + and JCPDS card no. 73-1370. This could be attributed to induced crystal-field effects due to the different ionic sizes of Ga 3 + and Gd 3 + compared with Al 3 + and Y 3 + . The photoluminescence (PL) spectra showed broad excitation from 350 to 550 nm with a maximum at 472 nm, and broad emission bands from 500 to 650 nm, centred at 578 nm for Y 3 Al 5 O 12 :Ce 3 + arising from the 5d → 4f transition of Ce 3 + . PL revealed a blue shift for Ga 3 + substitution and a red shift for Gd 3 + substitution. UV-Vis showed two absorption peaks at 357 and 457 nm for Y 3 Al 5 O 12 :Ce 3 + , with peaks shifting to 432 nm for Ga 3 + and 460 nm for Gd 3 + substitutions. Changes in the trap levels or in the depth and number of traps due to Ce 3 + were analysed using thermoluminescence (TL) spectroscopy. This revealed the existence of shallow and deep traps. It was observed that Ga 3 + substitution contributes to the shallowest traps at 74 °C and fewer deep traps at 163 °C, followed by Gd 3 + with shallow traps at 87 °C and deep traps at 146 °C. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Ce isotope systematics of island arc lavas from the Lesser Antilles

NASA Astrophysics Data System (ADS)

Bellot, Nina; Boyet, Maud; Doucelance, Régis; Pin, Christian; Chauvel, Catherine; Auclair, Delphine

2015-11-01

The La-Ce systematics has one of the longest half-lifes (T1/2 = 292.5 Ga) of radioactive decay systems used in isotope geochemistry. Variations of the 138Ce/142Ce ratio are expected to be small and the use of Ce as isotopic tracer requires a very precise measurement. Compared to Sm-Nd studies, the La-Ce decay system can provide additional information about the nature of sediments recycled in subduction zones, because unusually large Ce anomalies relative to the neighboring rare earth elements exist in marine sediments such as fish teeth or hydrothermal deposits. Here, we present a chemical purification technique for Ce, and mass spectrometric technique to perform accurate and reproducible analyses of Ce isotopes of natural samples. We report a large set of Ce isotope data including analysis of 2 Ce reference material solutions (AMES and JMC-304), 2 rock standards (BCR-2 and BHVO-2), 2 chondrites (the carbonaceous chondrite Allende and the enstatite chondrite Sahara 97072), 4 mid-ocean ridge basalts, 30 arc lavas from the Martinique Island and 5 oceanic sediments from DSDP-site 144 drilled on the Demerara rise. The long-term, external precision obtained on the AMES reference material is 80 ppm (2 s.d., 138Ce/142Ce = 0.0225732 ± 18, n = 89). However, we note an evolution of isotopic ratios measured in static mode over the duration of this study (33 months). When the reproducibility is calculated from the AMES reference material measured during the same analytical session, it averages 40 ppm. All the 138Ce/142Ce ratios have been normalized to the AMES value of 0.0225746 (measured in session 7, 2 s.d. = 14 ppm, n = 8), a session during which the chondritic value has been defined and the peak tailing was negligible. The 138Ce/142Ce ratio measured for the JMC-304 Ce reference reagent is 0.0225706 ± 9 (2 s.d. = 38 ppm, n = 10). The analytical precision on natural samples is improved by a factor of about 4 in relation to previous studies on island arcs (Tanaka et al., 1987; Shimizu et al., 1992). The 138Ce/142Ce ratios of the two chondrites are identical within uncertainty and similar to previous determinations done on other meteorites; the average value is 0.0225654 ± 7 (2 s.d. = 32 ppm). Martinique samples show a limited but significant range of variations for 138Ce/142Ce ratios (∼2 ε-units). The latter ratios correlate well with the Nd isotopes and define a binary mixing between a depleted mantle and subducted sediments that could be similar to those drilled at DSDP-site 144 (Leg 14). The Martinique lavas do not define a single curve in the εCe vs. εNd diagram, but a band. The apparent scattering can be explained by the involvement of sediments with different Ce isotope compositions and/or variations in the melting process itself such as the effect of melting on the light rare earth element ratios. The Ce isotopic signature of Martinique samples is dominated by the contribution of old terrigeneous sediments. However, according to our mixing models a low contribution of a few percent of marine sediment material in the source of the lavas is undetectable and therefore cannot be definitely excluded. Although the participation of marine sediments in this arc system is not demonstrated, our calculations show that the La-Ce system has a potential as geochemical tracer despite its very long half-life.

Interplay of antiferromagnetism and Kondo effect in (Ce1-xLax) 8Pd24 Al

NASA Astrophysics Data System (ADS)

Bashir, A. K.; Tchoula Tchokonté, M. B.; Britz, D.; Strydom, A. M.; Kaczorowski, D.

2017-07-01

The interplay of antiferromagnetic (AFM) and Kondo effect in Ce8Pd24 Al with the dilution of Ce with La is investigated by means of electrical and thermal transport and magnetic properties measurements. X - ray diffraction studies confirm a cubic AuCu3 - type crystal structure with space group Pm 3 bar m for all compositions in the alloy series (Ce1-xLax) 8Pd24 Al (0 ≤ x ≤ 1) . Electrical resistivity, ρ (T) results show evolution from coherent Kondo lattice scattering with a well defined Kondo peak at Tmax to incoherent single-ion Kondo scattering with increasing La content x. Magnetoresistivity MR measurements on Ce dilute alloys are negative and analyzed based on the calculations by Schlottmann for the Bethe - ansatz in the framework of the Coqblin - Schrieffer model and yield values of the Kondo temperature TK and the effective moment of the Kondo ion μK. The decrease of Tmax and TK is described by the compressible Kondo lattice model. The thermoelectric power, S(T) measurements are interpreted within the phenomenological resonance model. The Lorentz number, L /L0 increases rapidly on cooling the samples and reaches a maximum value around 6 K. The magnetic susceptibility, χ (T) data at high temperature follow the Curie - Weiss behaviour and yield effective magnetic moments, μeff values across the series close to the value of 2.54 μB expected for the free Ce3+ - ion. The low temperature χ (T) shows an AFM anomaly associated with a Néel temperature TN for alloys in the range 0 ≤ x ≤ 0.2 . No metamagnetic transition was observed from the magnetization results, M (μ0 H) .

In vitro and in vivo studies of an aqueous extract of Matricaria recutita (German chamomile) on the radiolabeling of blood constituents, on the morphology of red blood cells and on the biodistribution of the radiopharmaceutical sodium pertechnetate

PubMed Central

Garcia-Pinto, Angélica B.; Santos-Filho, Sebastião D.; Carvalho, Jorge J.; Pereira, Mário J. S.; Fonseca, Adenilson S.; Bernardo-Filho, Mário

2013-01-01

Background: Natural products might alter the labeling of blood constituents with technetium-99m (99mTc) and these results may be correlated with modifications of the shape of the red blood cells (RBC). The biodistribution of radiopharmaceuticals can be also altered. Objective: This investigation aimed to determine biological effects of an aqueous extract of chamomile (CE). Materials and Methods: To study the effect of the CE on the labeling of blood constituents with 99mTc, in vitro and in vivo assays were performed. The effect of the CE on the morphology of RBC was observed under light microscope. The images were acquired, processed, and the perimeter/area ratio of the RBC determined. To analyze the effect of the CE on biodistribution of the sodium pertechnetate (Na99mTcO4) in Wistar rats, these animals were treated or not with a CE. Na99mTcO4 was injected, the rats were sacrificed, the organs were removed, weighted and percentage of radioactivity/gram calculated. Result: In the in vitro experiment, the radioactivity on blood cells compartment and on insoluble fractions of plasma was diminished. The shape and the perimeter/area ratio of the RBC were altered in in vitro assays. An increase of the percentage of radioactivity of Na99mTcO4 was observed in stomach after in vivo treatment. Conclusion: These results could be due to substances of the CE or by the products of the metabolism of this extract in the animal organism. These findings are examples of drug interaction with a radiopharmaceutical, which could lead to misdiagnosis in clinical practice with unexpected consequences. PMID:24143045

Environmental Geochemistry of Cerium: Applications and Toxicology of Cerium Oxide Nanoparticles

PubMed Central

Dahle, Jessica T.; Arai, Yuji

2015-01-01

Cerium is the most abundant of rare-earth metals found in the Earth’s crust. Several Ce-carbonate, -phosphate, -silicate, and -(hydr)oxide minerals have been historically mined and processed for pharmaceutical uses and industrial applications. Of all Ce minerals, cerium dioxide has received much attention in the global nanotechnology market due to their useful applications for catalysts, fuel cells, and fuel additives. A recent mass flow modeling study predicted that a major source of CeO2 nanoparticles from industrial processing plants (e.g., electronics and optics manufactures) is likely to reach the terrestrial environment such as landfills and soils. The environmental fate of CeO2 nanoparticles is highly dependent on its physcochemical properties in low temperature geochemical environment. Though there are needs in improving the analytical method in detecting/quantifying CeO2 nanoparticles in different environmental media, it is clear that aquatic and terrestrial organisms have been exposed to CeO2 NPs, potentially yielding in negative impact on human and ecosystem health. Interestingly, there has been contradicting reports about the toxicological effects of CeO2 nanoparticles, acting as either an antioxidant or reactive oxygen species production-inducing agent). This poses a challenge in future regulations for the CeO2 nanoparticle application and the risk assessment in the environment. PMID:25625406

Method development of enantiomer separations by affinity capillary electrophoresis, cyclodextrin electrokinetic chromatography and capillary electrophoresis-mass spectrometry.

PubMed

Tanaka, Yoshihide

2002-07-01

Capillary electrophoresis (CE) has become a powerful tool for enantiomer separations during the last decade. Since 1993, the author has investigated enantiomer separations by affinity capillary electrophoresis (affinity CE) with some proteins and by cyclodextrin electrokinetic chromatography (CDEKC) with some charged cyclodextrins (CDs). Many successful enantiomer separations are demonstrated from our study in this review article. In the enantiomer separations by affinity CE, the deterioration of detection sensitivity was observed under high concentration of the protein in running solutions. The partial filling technique was practically useful to solve the serious problem. It allowed operation at high protein concentrations, such as 500 mumol/L, without the detection problem. Charged CDs had several advantages for the enantiomer separations over neutral ones. Strong electrostatic interactions between a charged CD and oppositely charged analytes should be effective for the formation of the complex. A large difference in electrophoretic mobility between the free analyte and the inclusion complex should also enhance the enantiomeric resolution. In CE-mass spectrometry (CE-MS), the partial filling technique was applied to avoid the introduction of nonvolatile chiral selectors into the CE-MS interface. By replacing the nonvolatile electrolytes in the running buffer by volatile ones, the separation conditions employed in CE with the UV detection method could be transferred to CE-MS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bidstrup, Morten, E-mail: bidstrup@plan.aau.dk; Kørnøv, Lone, E-mail: lonek@plan.aau.dk; Partidário, Maria Rosário, E-mail: mariapartidario@tecnico.ulisboa.pt

Cumulative effects (CE) assessment is lacking quality in impact assessment (IA) worldwide. It has been argued that the strategic environmental assessment (SEA) provides a suitable IA framework for addressing CE because it is applied to developments with broad boundaries, but few have tested this claim. Through a case study on the Danish mining sector, this article explores how plan boundaries influence the analytical boundaries applied for assessing CE in SEA. The case was studied through document analysis in combination with semi-structured group interviews of the responsible planners, who also serve as SEA practitioners. It was found that CE are tomore » some extent assessed and managed implicitly throughout the planning process. However, this is through a focus on lowering the cumulative stress of mining rather than the cumulative stress on and capacity of the receiving environment. Plan boundaries do influence CE assessment, though all boundaries are not equally influential. The geographical and time boundaries of the Danish mining plans are broad or flexible enough to accommodate a meaningful assessment of CE, but the topical boundary is restrictive. The study indicates that collaboration among planning authorities and legally appointed CE leadership may facilitate better practice on CE assessment in sector-specific SEA contexts. However, most pressing is the need for relating assessment to the receiving environment as opposed to solely the stress of a proposed plan.« less

Environmental geochemistry of cerium: applications and toxicology of cerium oxide nanoparticles.

PubMed

Dahle, Jessica T; Arai, Yuji

2015-01-23

Cerium is the most abundant of rare-earth metals found in the Earth's crust. Several Ce-carbonate, -phosphate, -silicate, and -(hydr)oxide minerals have been historically mined and processed for pharmaceutical uses and industrial applications. Of all Ce minerals, cerium dioxide has received much attention in the global nanotechnology market due to their useful applications for catalysts, fuel cells, and fuel additives. A recent mass flow modeling study predicted that a major source of CeO2 nanoparticles from industrial processing plants (e.g., electronics and optics manufactures) is likely to reach the terrestrial environment such as landfills and soils. The environmental fate of CeO2 nanoparticles is highly dependent on its physcochemical properties in low temperature geochemical environment. Though there are needs in improving the analytical method in detecting/quantifying CeO2 nanoparticles in different environmental media, it is clear that aquatic and terrestrial organisms have been exposed to CeO2 NPs, potentially yielding in negative impact on human and ecosystem health. Interestingly, there has been contradicting reports about the toxicological effects of CeO2 nanoparticles, acting as either an antioxidant or reactive oxygen species production-inducing agent). This poses a challenge in future regulations for the CeO2 nanoparticle application and the risk assessment in the environment.

Neuropeptide Y Opposes Alcohol Effects on GABA Release in Amygdala and Blocks the Transition to Alcohol Dependence

PubMed Central

Gilpin, Nicholas W.; Misra, Kaushik; Herman, Melissa A.; Cruz, Maureen T.; Koob, George F.; Roberto, Marisa

2011-01-01

Background During the transition to alcohol and drug addiction, neuromodulator systems in the extended amygdala are recruited to mediate aspects of withdrawal and relapse via convergence on inhibitory GABA neurons in central amygdala (CeA). Methods This study investigated the role of neuropeptide Y (NPY) in excessive alcohol drinking by making rats dependent on alcohol via alcohol vapor inhalation. This study also utilized intracellular and whole-cell recording techniques to determine the effects of NPY on GABAergic inhibitory transmission in CeA, synaptic mechanisms involved in these NPY effects, and NPY interactions with alcohol in the CeA of alcohol-naïve and alcohol-dependent rats. Results Chronic NPY treatment blocked excessive operant alcohol-reinforced responding associated with alcohol dependence, as well as gradual increases in alcohol responding by intermittently tested non-dependent controls. NPY decreased baseline GABAergic transmission and reversed alcohol-induced enhancement of inhibitory transmission in CeA by suppressing GABA release via actions at presynaptic Y2 receptors. Conclusions These results highlight NPY modulation of GABAergic signaling in central amygdala as a promising pharmacotheraputic target for the treatment of alcoholism. GABA neurons in the CeA likely constitute a major point of convergence for neuromodulator systems recruited during the transition to alcohol dependence. PMID:21459365

Effect of surface modification on photoluminescence properties of Y3Al5O12:Ce3+, Gd3+ nano-phosphors.

PubMed

Li, Jie; Zhao, Junfu; Zhou, Hefeng; Liang, Jian; Liu, Xuguang; Xu, Bingshe

2011-04-01

In this study, a series of Y(3)Al(5)O(12):Ce(3+), Gd(3+) nano-phosphors were prepared using a simply wet chemical process with polyvinyl pyrrolidone as a modifier. The crystal and bonding structures of Y(3)Al(5)O(12):Ce(3+), Gd(3+) nano-phosphors prepared with different weight percentages of polyvinyl pyrrolidone were characterized by X-ray diffractometry and infrared spectrometry. The decomposition process of dried precursor gel with adding 1.37 wt% polyvinyl pyrrolidone was investigated by differential thermal and thermogravimetric analysis. The effect of surface modification on photoluminescence properties for the samples was studied. The results show that the steric hindrance effect of polyvinyl pyrrolidone leads to high dispersion and good crystallinity of Y(3)Al(5)O(12):Ce(3+), Gd(3+) nano-phosphors prepared with adding a proper weight percentages of polyvinyl pyrrolidone. Adding polyvinyl pyrrolidone is beneficial for the photoluminescence enhancement of the samples, which is attributed to the promotion of the incorporation of Ce(3+) and Gd(3+) into the Y(3)Al(5)O(12) nanocrystal and the surface passivation of the nano-particles by the polyvinyl pyrrolidone molecules. Copyright © 2011 Elsevier B.V. All rights reserved.

Glutamate Receptors in the Central Nucleus of the Amygdala Mediate Cisplatin-Induced Malaise and Energy Balance Dysregulation through Direct Hindbrain Projections

PubMed Central

Alhadeff, Amber L.; Holland, Ruby A.; Nelson, Alexandra; Grill, Harvey J.

2015-01-01

Cisplatin chemotherapy is used commonly to treat a variety of cancers despite severe side effects such as nausea, vomiting, and anorexia that compromise quality of life and limit treatment adherence. The neural mechanisms mediating these side effects remain elusive despite decades of clinical use. Recent data highlight the dorsal vagal complex (DVC), lateral parabrachial nucleus (lPBN), and central nucleus of the amygdala (CeA) as potential sites of action in mediating the side effects of cisplatin. Here, results from immunohistochemical studies in rats identified a population of cisplatin-activated DVC neurons that project to the lPBN and a population of cisplatin-activated lPBN calcitonin gene-related peptide (CGRP, a marker for glutamatergic neurons in the lPBN) neurons that project to the CeA, outlining a neuroanatomical circuit that is activated by cisplatin. CeA gene expressions of AMPA and NMDA glutamate receptor subunits were markedly increased after cisplatin treatment, suggesting that CeA glutamate receptor signaling plays a role in mediating cisplatin side effects. Consistent with gene expression results, behavioral/pharmacological data showed that CeA AMPA/kainate receptor blockade attenuates cisplatin-induced pica (a proxy for nausea/behavioral malaise in nonvomiting laboratory rodents) and that CeA NMDA receptor blockade attenuates cisplatin-induced anorexia and body weight loss in addition to pica, demonstrating that glutamate receptor signaling in the CeA is critical for the energy balance dysregulation caused by cisplatin treatment. Together, these data highlight a novel circuit and CGRP/glutamatergic mechanism through which cisplatin-induced malaise and energy balance dysregulation are mediated. SIGNIFICANCE STATEMENT To treat cancer effectively, patients must follow prescribed chemotherapy treatments without interruption, yet most cancer treatments produce side effects that devastate quality of life (e.g., nausea, vomiting, anorexia, weight loss). Although hundreds of thousands of patients undergo chemotherapies each year, the neural mechanisms mediating their side effects are unknown. The current data outline a neural circuit activated by cisplatin chemotherapy and demonstrate that glutamate signaling in the amygdala, arising from hindbrain projections, is required for the full expression of cisplatin-induced malaise, anorexia, and body weight loss. Together, these data help to characterize the neural circuits and neurotransmitters mediating chemotherapy-induced energy balance dysregulation, which will ultimately provide an opportunity for the development of well tolerated cancer and anti-emetic treatments. PMID:26245970

Sea surface temperature variability in the Gulf of Mexico from 1734-2008 CE: A reconstruction using cross-dated Sr/Ca records from the coral Siderastrea siderea

NASA Astrophysics Data System (ADS)

DeLong, K. L.; Flannery, J. A.; Quinn, T. M.; Maupin, C. R.; Lin, K.; Shen, C.

2013-12-01

Sea surface temperature (SST) variability in the Gulf of Mexico impacts climate in Central and North America because the Gulf is a major source of moisture and is a source region for the Gulf Stream, which transports ocean heat northward. Here we use skeletal variations in coral Sr/Ca from three Siderastrea siderea coral colonies within the Dry Tortugas National Park in the southeastern Gulf of Mexico (24°42'N, 82°48'W) to develop 274 years of monthly-resolved SST variations. The cross-dated chronology, determined by counting annual density bands and correlating Sr/Ca variations, is verified by four replicated high precision 230Th dates (×1.7-37 years, 2σ). Calibration and verification of our replicated coral Sr/Ca-SST reconstruction with Dry Tortugas SST (r = 0.98 and 0.55 for monthly and 36-month smoothed, respectively; 1992-2008 CE) and Key West, Florida surface air temperature (1895-2008 CE) measurements reveals similar covariance (r = 0.96 and 0.56 for monthly and 36-month smoothed, respectively). The absolute coral SST reconstruction is consistent with SST recorded at the Dry Tortugas lighthouse from 1879-1907 CE indicating that this coral Sr/Ca-SST relationship is stable on centennial time scales. The Sr/Ca-SST reconstruction reveals ~2.0°C interannual variability, ~1.5°C decadal fluctuations, and a 0.7°C warming trend for the past 274 years. Secular variability in our reconstruction is similar to approximately decadally resolved planktic foraminifer Mg/Ca records from the northern Gulf of Mexico. The coral Sr/Ca-SST reconstruction reveals colder decades (~1.5°C) suggesting a reduction in moisture and ocean heat flux from the Gulf of Mexico. We find winter extremes are more variable than summer extremes (×2.2°C vs. ×1.6°C, 2σ) with a stronger warming trend (1°C) in the summers suggesting continued warming may increase coral bleaching.

Synthesis of CeO2 nanoparticles: Photocatalytic and antibacterial activities

NASA Astrophysics Data System (ADS)

Reddy Yadav, L. S.; Lingaraju, K.; Daruka Prasad, B.; Kavitha, C.; Banuprakash, G.; Nagaraju, G.

2017-05-01

We have successfully synthesized CeO2 nanoparticles (Nps) via the solution combustion method using sugarcane juice as a novel combustible fuel. The structural features, optical properties and morphology of the nanoparticles were characterized using XRD, FTIR, and Raman spectroscopy, UV-Vis, SEM and TEM. Structural characterization of the product shows cubic phase CeO2 . FTIR and Raman spectrum show characteristic peaks due to the presence of Ce-O vibration. SEM images show a porous structure and, from TEM images, the size of the nanoparticles were found to be ˜ 50 nm. The photocatalytic degradation of the methylene blue (MB) dye was examined using CeO2 Nps under solar irradiation as well as UV light irradiation and we studied the effect of p H, catalytic load and concentration on the degradation of the MB dye. Furthermore, the antibacterial properties of CeO2 Nps were investigated against Gram+ve and Gram- ve pathogenic bacterial strains using the agar well diffusion method.

2 inch size Czochralski growth and scintillation properties of Li+ co-doped Ce:Gd3Ga3Al2O12

NASA Astrophysics Data System (ADS)

Kamada, Kei; Shoji, Yasuhiro; Kochurikhin, Vladimir V.; Yoshino, Masao; Okumura, Satoshi; Yamamoto, Seiichi; Yeom, Jung Yeol; Kurosawa, Shunsuke; Yokota, Yuui; Ohashi, Yuji; Nikl, Martin; Yoshino, Masao; Yoshikawa, Akira

2017-03-01

The 2 inch size Li 0.15 and 1.35 mol% co-doped Ce:Gd3Al2Ga3O12 single crystals were prepared by the Czochralski (Cz) method. Absorption and luminescence spectra were measured together with several other scintillation characteristics, namely the scintillation decay and light yield to reveal the effect of Li co-doping. Ce4+ CT absorption below 350 nm is clearly enhanced by Li co-doping as same as divalent ions co-doping. By 1.35 at.% Li co-doping, light yield was decrease to 88% of the Ce: GAGG standard and decay time was accelerated to 34.3ns 21.0%, 84.6ns 68.7%, 480ns 10.3%. The timing resolution measurement for a pair of 3 × 3 × 3mm3 size Li,Ce:GAGG scintillator crystals was performed using Si-PMs and the timing resolution of the 1.35 at.% Li co-doped Ce:GAGG was 218ps.

Neural and Behavioral Correlates of PTSD and Alcohol Use

DTIC Science & Technology

2013-10-01

of GABAergic interneurons known as intercalated (ITC) cells located between the BLA and CeA [69], providing an effective means of gating CeA...across different experiments. Future studies directly comparing the effects of 5- HT manipulations within the different amygdala subregions across... effects make them poorly tolerated. Furthermore, because atypical antipsychotics also have high affinity for 5- HT receptors, the contribution of DA

Catalytic hydrolysis of COS over CeO2 (110) surface: A density functional theory study

NASA Astrophysics Data System (ADS)

Song, Xin; Ning, Ping; Wang, Chi; Li, Kai; Tang, Lihong; Sun, Xin

2017-08-01

Density functional theory (DFT) calculations were performed to investigate the reaction pathways for catalytic hydrolysis of COS over CeO2 (110) surface using Dmol3 model. The thermodynamic stability analysis for the suggested routes of COS hydrolysis to CO2 and H2S was evaluated. The absolute values of adsorption energy of H2O-CeO2 are higher than that of COS-CeO2. Meanwhile, the adsorption energy and geometries show that H2O is easier adsorbed on the surface of CeO2 (110) than COS. H2O plays a role as a bridge in the process of joint adsorption. H2O forms more Cesbnd Osbnd H groups on the CeO2 (110) surface. CeO2 decreases the maximum energy barrier by 76.15 kcal/mol. The migration of H from H2O to COS is the key for the hydrolysis reaction. Csbnd O channel is easier to occur than Csbnd S channel. Experimental result shows that adding of CeO2 can increase COS removal rate and prolong the 100% COS removal rate from 180 min to 210 min. The difference between Fe2O3 and CeO2 for the hydrolysis of COS is characterized in the atomic charge transfer and the formation of Hsbnd O bond and Hsbnd S bond. The transfer effect of H in H2O to S in COS over CeO2 decreases the energy barriers of hydrolysis reaction, and enhances the reaction activity of COS hydrolysis.

8 MeV electron beam induced modifications in the thermal, structural and electrical properties of nanophase CeO2 for potential electronics applications

NASA Astrophysics Data System (ADS)

Babitha, K. K.; Sreedevi, A.; Priyanka, K. P.; Ganesh, S.; Varghese, Thomas

2018-06-01

The effect of 8 MeV electron beam irradiation on the thermal, structural and electrical properties of CeO2 nanoparticles synthesized by chemical precipitation route was investigated. The dose dependent effect of electron irradiation was studied using various characterization techniques such as, thermogravimetric and differential thermal analyses, X-ray diffraction, Fourier transformed infrared spectroscopy and impedance spectroscopy. Systematic investigation based on the results of structural studies confirm that electron beam irradiation induces defects and particle size variation on CeO2 nanoparticles, which in turn results improvements in AC conductivity, dielectric constant and loss tangent. Structural modifications and high value of dielectric constant for CeO2 nanoparticles due to electron beam irradiation make it as a promising material for the fabrication of gate dielectric in metal oxide semiconductor devices.