Substitutional Cd and Cd-Oxygen Vacancy Complexes in ZrO2 and Ce-doped ZrO_2

NASA Astrophysics Data System (ADS)

Zacate, Matthew O.; Karapetrova, E.; Platzer, R.; Gardner, J. A.; Evenson, W. E.; Sommers, J. A.

1996-03-01

We are using Perturbed Angular Correlation Spectroscopy (PAC) to study oxygen vacancy (V_O) dynamics in tetragonal ZrO2 and Ce-doped ZrO_2. PAC requires a radioactive probe atom, Cd in this study, which sits substitutionally for a Zr ion. Cd is doubly-negatively charged relative to the lattice and attracts doubly-positively charged V_Os. Pure tetragonal zirconia exists only above 950 ^circC and in this temperature range, the V_Os are very mobile. Above 950 ^circC we observe V_Os rapidly hopping about the Cd allowing us to determine the VO concentration and the trapping energy. We have been Ce-doping to stabilize the tetragonal phase to lower temperature to determine the electric field gradient the Cd experiences due to a stationary V_O. As a consequence of the Ce-doping, we observe a local lattice distortion about the Cd which increases with Ce-doping.

Diagnostic yield of capsule endoscopy in refractory celiac disease.

PubMed

Barret, Maximilien; Malamut, Georgia; Rahmi, Gabriel; Samaha, Elia; Edery, Joël; Verkarre, Virginie; Macintyre, Elizabeth; Lenain, Emilie; Chatellier, Gilles; Cerf-Bensussan, Nadine; Cellier, Christophe

2012-10-01

Capsule endoscopy (CE) allows for the assessment of the small bowel in numerous intestinal diseases, including celiac disease (CD). The main advantage of CE is the complete visualization of the intestinal mucosal surface. The objective of this study was to investigate whether CE can predict the severity of CD and detect complications. We retrospectively studied the medical files of 9 patients with symptomatic CD, 11 patients with refractory celiac disease type I (RCDI) and 18 patients with refractory celiac disease type II (RCDII), and 45 patients without CD who were investigated both CE and upper endoscopy or enteroscopy. The type of CD was diagnosed on the basis of a centralized histological review, flow cytometry analysis of intraepithelial lymphocytes, and the analysis of T-cell receptor rearrangement by multiplex polymerase chain reaction. A total of 47 CEs (10, 11, and 26 CEs in the symptomatic CD, RCDI, and RCDII groups, respectively) from the 38 celiac patients and 47 CEs from the 45 nonceliac patients were retrospectively reviewed. Villous atrophy, numerous, or distally located ulcers were more frequent in celiac patients than in controls. Among celiac patients, CE was of acceptable quality in 96% of cases and was complete in 62% of cases. The concordance of CE with histology for villous atrophy was better than that of optic endoscopy (κ coefficient =0.45 vs. 0.24, P<0.001). Extensive mucosal damage on CE was associated with low serum albumin (P=0.003) and the RCDII form (P=0.02). Three cases of overt lymphoma were detected by CE during the follow-up. CE findings have a satisfactory concordance with histology and nutritional status in patients with symptomatic or refractory CD. Moreover, CE may predict the type of RCD and allows for the early detection of overt lymphoma.

Adsorption of cadmium on cerium oxide nanoparticles and oyster shells

NASA Astrophysics Data System (ADS)

Ji, Yongbo; Liu, Zhuomiao; Dang, Yonghui; Xu, Lina; Ning, Fangyuan; Xue, Yinhao; Wei, Yongpeng; Dai, Yanhui

2018-03-01

This study investigated the adsorption of cadmium (Cd(II)) by cerium oxide nanoparticles (CeO2 NPs) and oyster shells in seawater. The results showed that the addition of Cd(II) significantly inhibited the agglomeration of CeO2 NPs both in DI water and seawater, increased the positive charges of CeO2 NPs in DI water and neutralized the negative charges of CeO2 NPs in seawater. Additionally, CeO2 NPs could adsorb Cd and the bioavailability of Cd was reduced in the presence of oyster shells. This study demonstrated that the adsorption of metals on shells should not be neglected for the accumulation of metals by shellfish.

Restricted L1 Estimators and Their Covariances,

DTIC Science & Technology

1980-06-01

CD22 w =e 1-.< l’ -- I -M Ce -=, -2 C 22 CD -. 00 CD LJ L":v, wD .-C >-C CD U., -D -a 22J CD: CD. Vt. U.1 . CD* 31- a UOC CD I" -J zI == CŖ - 1- InCC.J...C 22 CC:.: 2 15Cb In0’C C 4 t’ 3 CD.2-cm I- I.- iC2 CD-3SJ U. cc CDam CC 22 0.-J~ I- iD C Me CC .JJ . A.2 Dt-2C. 2. D ~ 2 CD, Z-i- C -J 2Cn LI CD22 ...22 "I.- bII CD 0.-..CW I -- k- -o. CDCD-c =DDCCC-ce CDI- 22eCCDC.C I-L- 5 2wI-CDUct. I4.CDgCD Ci L., 2=9 E Mm t,2 cm CD22 ,,- D.-.2RCC Ce:CD .Cc n 9

Performances of some low-cost counter electrode materials in CdS and CdSe quantum dot-sensitized solar cells.

PubMed

Jun, Hieng Kiat; Careem, Mohamed Abdul; Arof, Abdul Kariem

2014-02-10

Different counter electrode (CE) materials based on carbon and Cu2S were prepared for the application in CdS and CdSe quantum dot-sensitized solar cells (QDSSCs). The CEs were prepared using low-cost and facile methods. Platinum was used as the reference CE material to compare the performances of the other materials. While carbon-based materials produced the best solar cell performance in CdS QDSSCs, platinum and Cu2S were superior in CdSe QDSSCs. Different CE materials have different performance in the two types of QDSSCs employed due to the different type of sensitizers and composition of polysulfide electrolytes used. The poor performance of QDSSCs with some CE materials is largely due to the lower photocurrent density and open-circuit voltage. The electrochemical impedance spectroscopy performed on the cells showed that the poor-performing QDSSCs had higher charge-transfer resistances and CPE values at their CE/electrolyte interfaces.

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.

Experimental constraints on the relative stabilities of the two systems monazite-(Ce) - allanite-(Ce) - fluorapatite and xenotime-(Y) - (Y,HREE)-rich epidote - (Y,HREE)-rich fluorapatite, in high Ca and Na-Ca environments under P-T conditions of 200-1000 MPa and 450-750 °C

NASA Astrophysics Data System (ADS)

Budzyń, Bartosz; Harlov, Daniel E.; Kozub-Budzyń, Gabriela A.; Majka, Jarosław

2017-04-01

The relative stabilities of phases within the two systems monazite-(Ce) - fluorapatite - allanite-(Ce) and xenotime-(Y) - (Y,HREE)-rich fluorapatite - (Y,HREE)-rich epidote have been tested experimentally as a function of pressure and temperature in systems roughly replicating granitic to pelitic composition with high and moderate bulk CaO/Na2O ratios over a wide range of P-T conditions from 200 to 1000 MPa and 450 to 750 °C via four sets of experiments. These included (1) monazite-(Ce), labradorite, sanidine, biotite, muscovite, SiO2, CaF2, and 2 M Ca(OH)2; (2) monazite-(Ce), albite, sanidine, biotite, muscovite, SiO2, CaF2, Na2Si2O5, and H2O; (3) xenotime-(Y), labradorite, sanidine, biotite, muscovite, garnet, SiO2, CaF2, and 2 M Ca(OH)2; and (4) xenotime-(Y), albite, sanidine, biotite, muscovite, garnet, SiO2, CaF2, Na2Si2O5, and H2O. Monazite-(Ce) breakdown was documented in experimental sets (1) and (2). In experimental set (1), the Ca high activity (estimated bulk CaO/Na2O ratio of 13.3) promoted the formation of REE-rich epidote, allanite-(Ce), REE-rich fluorapatite, and fluorcalciobritholite at the expense of monazite-(Ce). In contrast, a bulk CaO/Na2O ratio of 1.0 in runs in set (2) prevented the formation of REE-rich epidote and allanite-(Ce). The reacted monazite-(Ce) was partially replaced by REE-rich fluorapatite-fluorcalciobritholite in all runs, REE-rich steacyite in experiments at 450 °C, 200-1000 MPa, and 550 °C, 200-600 MPa, and minor cheralite in runs at 650-750 °C, 200-1000 MPa. The experimental results support previous natural observations and thermodynamic modeling of phase equilibria, which demonstrate that an increased CaO bulk content expands the stability field of allanite-(Ce) relative to monazite-(Ce) at higher temperatures indicating that the relative stabilities of monazite-(Ce) and allanite-(Ce) depend on the bulk CaO/Na2O ratio. The experiments also provide new insights into the re-equilibration of monazite-(Ce) via fluid-aided coupled dissolution-reprecipitation, which affects the Th-U-Pb system in runs at 450 °C, 200-1000 MPa, and 550 °C, 200-600 MPa. A lack of compositional alteration in the Th, U, and Pb in monazite-(Ce) at 550 °C, 800-1000 MPa, and in experiments at 650-750 °C, 200-1000 MPa indicates the limited influence of fluid-mediated alteration on volume diffusion under high P-T conditions. Experimental sets (3) and (4) resulted in xenotime-(Y) breakdown and partial replacement by (Y,REE)-rich fluorapatite to Y-rich fluorcalciobritholite. Additionally, (Y,HREE)-rich epidote formed at the expense of xenotime-(Y) in three runs with 2 M Ca(OH)2 fluid, at 550 °C, 800 MPa; 650 °C, 800 MPa; and 650 °C, 1000 MPa similar to the experiments involving monazite-(Ce). These results confirm that replacement of xenotime-(Y) by (Y,HREE)-rich epidote is induced by a high Ca bulk content with a high CaO/Na2O ratio. These experiments demonstrate also that the relative stabilities of xenotime-(Y) and (Y,HREE)-rich epidote are strongly controlled by pressure.

The Neuropsychology of Imagery Processing

DTIC Science & Technology

1989-12-01

14260 Providence RI 02912 Or Elizabeth B5ork Or John R Anderson Department of Psychology Department of Psychology University of California Carnegie...University Cornell University Fullerton CA 92634 Ithaca NY 14853 Or Norma Graham - r Murray Glanzer 314 Schermerhorn Hall, Psychology Department of...OF 01I4SPONSIGLE oINOiVtOUAL 3 . 2b TSLIP0ONS NUMIDEA 22c. Off"CE SVIMOOL Alfred R . Frealy I~~d 4IoCd 00 FORM 1473.83 APR 601TION 0P 1IJAN 72 IS

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.

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.

Investigation of structural and luminescent properties of Ce{sup 3+}/Mn{sup 2+} ions-doped Ca{sub 5}(PO{sub 4}){sub 3}F

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

Zhang, Lei; Fu, Zuoling, E-mail: zlfu@jlu.edu.cn; Wu, Zhijian

Graphical abstract: The structural and luminescent properties FAP: Ce{sup 3+} and FAP: Ce{sup 3+}, Mn{sup 2+} were investigated in detail by the spectral measurement and theoretical calculation. The emission of Ce{sup 3+} is fitted by two Gaussian functions dashed lines in wavenumber to further confirm the Ce{sup 3+} ion simultaneously occupy the 4f and 6h sites Ca{sub 5}(PO{sub 4})F host. - Highlights: • A simple hydrothermal method has been used to prepare Ca{sub 5}(PO{sub 4}){sub 3}F: Ce{sup 3+}, Mn{sup 2+} powders with structural and luminescent analysis. • The emission of Ce{sup 3+} is fitted by two Gaussian functions to confirmmore » the Ce{sup 3+} ion simultaneously to occupy the 4f and 6h sites in Ca{sub 5}(PO{sub 4}){sub 3}F host. • Due to an efficient energy transfer, the existence of Ce{sup 3+} (sensitizer) can dramatically enhance the green emission of Mn{sup 2+} (activator) in co-doped samples. - Abstract: Ce{sup 3+}/Mn{sup 2+} ions-doped oxyapatite calcium fluorapatite [Ca{sub 5}(PO{sub 4}){sub 3}F, FAP] has been successfully synthesized by a facile one-step hydrothermal method. The luminescent properties of Ce{sup 3+}- and Ce{sup 3+}/Mn{sup 2+}- activated FAP phosphors were investigated using the photoluminescence (PL) and photoluminescence excitation (PLE) spectra. The emission of Ce{sup 3+} was fitted by two Gaussian functions with dashed lines in wavenumber to confirm the Ce{sup 3+} ion simultaneously to occupy the 4f and 6h sites in Ca{sub 5}(PO{sub 4}){sub 3}F host, which was consistent with the calculated results of crystal field based on chemical bond theory. In addition, the existence of Ce{sup 3+} (sensitizer) can dramatically enhance the green emission of Mn{sup 2+} (activator) in Ce{sup 3+}/Mn{sup 2+} ions co-doped samples due to an efficient energy transfer from Ce{sup 3+} to Mn{sup 2+}. All of these results could help us understand the site assignments and optical properties of the rare earth ions doped in hexagonal Ca{sub 5}(PO{sub 4}){sub 3}F.« less

Multiple Loops of the Dihydropyridine Receptor Pore Subunit Are Required for Full-Scale Excitation-Contraction Coupling in Skeletal Muscle

PubMed Central

Carbonneau, Leah; Bhattacharya, Dipankar; Sheridan, David C.; Coronado, Roberto

2005-01-01

Understanding which cytosolic domains of the dihydropyridine receptor participate in excitation-contraction (EC) coupling is critical to validate current structural models. Here we quantified the contribution to skeletal-type EC coupling of the α1S (CaV1.1) II-III loop when alone or in combination with the rest of the cytosolic domains of α1S. Chimeras consisting of α1C (CaV1.2) with α1S substitutions at each of the interrepeat loops (I-II, II-III, and III-IV loops) and N- and C-terminal domains were evaluated in dysgenic (α1S-null) myotubes for phenotypic expression of skeletal-type EC coupling. Myotubes were voltage-clamped, and Ca2+ transients were measured by confocal line-scan imaging of fluo-4 fluorescence. In agreement with previous results, the α1C/α1S II-III loop chimera, but none of the other single-loop chimeras, recovered a sigmoidal fluorescence-voltage curve indicative of skeletal-type EC coupling. To quantify Ca2+ transients in the absence of inward Ca2+ current, but without changing the external solution, a mutation, E736K, was introduced into the P-loop of repeat II of α1C. The Ca2+ transients expressed by the α1C(E736K)/α1S II-III loop chimera were ∼70% smaller than those expressed by the Ca2+-conducting α1C/α1S II-III variant. The low skeletal-type EC coupling expressed by the α1C/α1S II-III loop chimera was confirmed in the Ca2+-conducting α1C/α1S II-III loop variant using Cd2+ (10−4 M) as the Ca2+ current blocker. In contrast to the behavior of the II-III loop chimera, Ca2+ transients expressed by an α1C/α1S chimera carrying all tested skeletal α1S domains (all α1S interrepeat loops, N- and C-terminus) were similar in shape and amplitude to wild-type α1S, and did not change in the presence of the E736K mutation or in the presence of 10−4 M Cd2+. Controls indicated that similar dihydropyridine receptor charge movements were expressed by the non-Ca2+ permeant α1S(E1014K) variant, the α1C(E736K)/α1S II-III loop chimera, and the α1C(E736K)/α1S chimera carrying all tested α1S domains. The data indicate that the functional recovery produced by the α1S II-III loop is incomplete and that multiple cytosolic domains of α1S are necessary for a quantitative recovery of the EC-coupling phenotype of skeletal myotubes. Thus, despite the importance of the II-III loop there may be other critical determinants in α1S that influence the efficiency of EC coupling. PMID:15849247

Results for aliovalent doping of CeBr3 with Ca2+

NASA Astrophysics Data System (ADS)

Guss, Paul; Foster, Michael E.; Wong, Bryan M.; Patrick Doty, F.; Shah, Kanai; Squillante, Michael R.; Shirwadkar, Urmila; Hawrami, Rastgo; Tower, Joshua; Yuan, Ding

2014-01-01

Despite the outstanding scintillation performance characteristics of cerium tribromide (CeBr3) and cerium-activated lanthanum tribromide, their commercial availability and application are limited due to the difficulties of growing large, crack-free single crystals from these fragile materials. This investigation employed aliovalent doping to increase crystal strength while maintaining the optical properties of the crystal. One divalent dopant (Ca2+) was used as a dopant to strengthen CeBr3 without negatively impacting scintillation performance. Ingots containing nominal concentrations of 1.9% of the Ca2+ dopant were grown, i.e., 1.9% of the CeBr3 molecules were replaced by CaBr2 molecules, to match our target replacement of 1 out of 54 cerium atoms be replaced by a calcium atom. Precisely the mixture was composed of 2.26 g of CaBr2 added to 222.14 g of CeBr3. Preliminary scintillation measurements are presented for this aliovalently doped scintillator. Ca2+-doped CeBr3 exhibited little or no change in the peak fluorescence emission for 371 nm optical excitation for CeBr3. The structural, electronic, and optical properties of CeBr3 crystals were studied using the density functional theory within the generalized gradient approximation. Calculated lattice parameters are in agreement with the experimental data. The energy band structures and density of states were obtained. The optical properties of CeBr3, including the dielectric function, were calculated.

Synthesis of CaO-CeO2 catalysts by soft template method for biodiesel production

NASA Astrophysics Data System (ADS)

Zheng, Y. C.; Yu, X. H.; Yang, J.

2017-06-01

Biodiesel has recently gained extensive attention. Catalysts play an important role in producing biodiesel by transesterification reaction. In this study, CaO-CeO2 catalysts are developed as the solid base catalyst. Using PDMS-PEO as a structure-directing agent, the prepared CaO-CeO2 catalysts have a three-dimensional interconnected porous structure, which benefits the transesterification reaction. While the added Ce slightly decreases the catalytic activity, the stability of the catalyst shows remarkable improvement. Considering the catalytic activity and stability, the best catalyst is determined to be catalyst 0.15-1073 (Ce/Ca molar ratio of 0.15 and calcination temperature of 1073 K). Under optimum reaction conditions, the biodiesel yield reaches to 97.5% and metal leaching is 117.7 ppm. For catalyst 0.15-1073 regenerated after four reaction cycles, the biodiesel yield is 94.1%. The results reveal that the CaO-CeO2 catalyst has good potential for application in large-scale biodiesel production in the future.

The crystal structure of galgenbergite-(Ce), CaCe2(CO3)4•H2O

NASA Astrophysics Data System (ADS)

Walter, Franz; Bojar, Hans-Peter; Hollerer, Christine E.; Mereiter, Kurt

2013-04-01

Galgenbergite-(Ce) from the type locality, the railroad tunnel Galgenberg between Leoben and St. Michael, Styria, Austria, was investigated. There it occurs in small fissures of an albite-chlorite schist as very thin tabular crystals building rosette-shaped aggregates associated with siderite, ancylite-(Ce), pyrite and calcite. Electron microprobe analyses gave CaO 9.49, Ce2O3 28.95, La2O3 11.70, Nd2O3 11.86, Pr2O3 3.48, CO2 30.00, H2O 3.07, total 98.55 wt.%. CO2 and H2O calculated by stoichiometry. The empirical formula (based on Ca + REE ∑3.0) is C{{a}_{1.00 }}{{( {C{{e}_{1.04 }}L{{a}_{0.42 }}N{{d}_{0.42 }}P{{r}_{0.12 }}} )}_{2.00 }}{{( {C{{O}_3}} )}_4}\\cdot {{H}_2}O , and the simplified formula is CaC{{e}_2}{{( {C{{O}_3}} )}_4}\\cdot {{H}_2}O . According to X-ray single crystal diffraction galgenbergite-(Ce) is triclinic, space group Poverline{1},a=6.3916(5) , b = 6.4005(4), c = 12.3898(9) Å, α = 100.884(4), β = 96.525(4), γ = 100.492(4)°, V = 483.64(6) Å3, Z = 2. The eight strongest lines in the powder X-ray diffraction pattern are [ d calc in Å/( I)/ hkl]: 5.052/(100)/011; 3.011/(70)/0-22; 3.006/(66)/004; 5.899/(59)/-101; 3.900/(51)/1-12; 3.125/(46)/-201; 2.526/(42)/022; 4.694/(38)/-102. The infrared absorption spectrum reveals H2O (OH-stretching mode at 3,489 cm-1, HOH bending mode at 1,607 cm-1) and indicates the presence of distinctly non-equivalent CO3-groups by double and quadruple peaks of their ν1, ν2, ν3 and ν4 modes. The crystal structure of galgenbergite-(Ce) was refined with X-ray single crystal data to R1 = 0.019 for 2,448 unique reflections ( I > 2 σ( I)) and 193 parameters. The three cation sites of the structure Ca(1), Ce(2) and Ce(3) have a modest mixed site occupation by Ca and small amount of REE (Ce, La, Pr, Nd) and vice versa. The structure is based on double layers parallel to (001), which are composed of Ca(1)Ce(2)(CO3)2 single layers with an ordered chessboard like arrangement of Ca and Ce, and with a roof tile-like stacking of the CO3 groups. Perpendicular to (001) the double layers are connected to a triclinic framework structure with good cleavage parallel to (001) by a differently organized and more open part of the structure formed by Ce(3)(CO3)2(H2O). Based on the topology of the CaCe(CO3)2 single layer in galgenbergite-(Ce), structural relationships to rutherfordine, to aragonite and ancylite type minerals, and to lanthanite are outlined.

PIK3C2A mRNA functions as a miR-124 sponge to facilitate CD151 expression and enhance malignancy of hepatocellular carcinoma cells.

PubMed

Liu, Tao; Zu, Cai-Hua; Wang, Shu-Sen; Song, Hong-Li; Wang, Zheng-Lu; Xu, Xin-Nv; Liu, Hong-Sheng; Wang, Yu-Liang; Shen, Zhong-Yang

2016-07-12

Competing endogenous RNAs (ceRNAs) are RNA transcripts that can crosstalk with each other by competing for shared microRNAs (miRNAs) through miRNA response elements (MREs). Involved in ceRNA networks, the RNA transcripts may be in a balance, disruption of which could lead to tumorigenesis. Here we reveal a ceRNA interaction between PIK3C2A and CD151 mRNAs in hepatocellular carcinoma (HCC) cells. PIK3C2A is a candidate ceRNA of CD151 because mRNA 3' untranslated regions (3'UTRs) of these two genes contain miR-124 binding sites. miR-124 is downregulated, while PIK3C2A and CD151 are upregulated in HCC cells compared with normal hepatocytes. Direct and negative regulation of PIK3C2A and CD151 by miR-124 was confirmed in HCC cells. miR-124 and the two potential ceRNAs are all recruited to the RNA-induced silencing complex (RISC). In HCC cell lines QGY- 7703 and SMMC-7721, and normal hepatic cell line HL-7702, miR-124 plays a tumor suppressor role by targeting PIK3C2A and CD151. The MREs within PIK3C2A 3'UTR can independently stimulate CD151 expression level by acting as miR-124 decoys. PIK3C2A MREs enhance HCC cell malignancy by absorbing endogenous miR-124 and activating CD151 in HCC cells. We conclude that PIK3C2A 3'UTR functions as a trans activator to stimulate CD151 by competing for miR-124 binding in HCC cells. The collaboration of PIK3C2A and CD151 through ceRNA mechanism may be implicated in HCC initiation and development.

Engineering and introduction of de novo disulphide bridges in organophosphorus hydrolase enzyme for thermostability improvement.

PubMed

Farnoosh, Gholamreza; Khajeh, Khosro; Latifi, Ali Mohammad; Aghamollaei, Hossein

2016-12-01

The organophosphorus hydrolase (OPH) has been used to degrade organophosphorus chemicals, as one of the most frequently used decontamination methods. Under chemical and thermal denaturing conditions, the enzyme has been shown to unfold. To utilize this enzyme in various applications, the thermal stability is of importance. The engineering of de novo disulphide bridges has been explored as a means to increase the thermal stability of enzymes in the rational method of protein engineering. In this study, Disulphide by Design software, homology modelling and molecular dynamics simulations were used to select appropriate amino acid pairs for the introduction of disulphide bridge to improve protein thermostability. The thermostability of the wild-type and three selected mutant enzymes were evaluated by half-life, delta G inactivation (ΔGi) and structural studies (fluorescence and far-UV CD analysis). Data analysis showed that half-life of A204C/T234C and T128C/E153C mutants were increased up to 4 and 24 min, respectively; however, for the G74C/A78C mutant, the half-life was decreased up to 9 min. For the T128C/E124C mutant, both thermal stability and Catalytic efficiency (kcat) were also increased. The half-life and ΔGi results were correlated to the obtained information from structural studies by circular dichroism (CD) spectrometry and extrinsic fluorescence experiments; as rigidity increased in A204C/T2234C and T128C/E153C mutants, half-life and ΔGi also increased. For G74C/A78C mutant, these parameters decreased due to its higher flexibility. The results were submitted a strong evidence for the possibility to improve the thermostability of OPH enzyme by introducing a disulphide bridge after bioinformatics design, even though this design would not be always successful.

Energy transfer in M₅(PO₄)₃  F:Eu²⁺,Ce³⁺ (M = Ca and Ba) phosphors.

PubMed

Shinde, K N; Dhoble, S J

2014-08-01

M5(PO4)3F:Eu(2+) (M = Ca and Ba) co-doped with Ce(3+) phosphors were successfully prepared by the combustion synthesis method. The introduction of co-dopant (Ce(3+)) into the host enhanced the luminescent intensity of the M5(PO4)3F:Eu(2+) (M = Ca and Ba) efficiently. Previously, we have reported the synthesis and photoluminescence properties of same phosphors. The aim of this article is to report energy transfer mechanism between Ce(3+) ➔Eu(2+) ions in M5(PO4)3F:Eu(2+) (M = Ca and Ba) phosphors, where Ce(3+) ions act as sensitizers and Eu(2+) ions act as activators. The M5(PO4)3F:Eu(2+) (M = Ca and Ba) co-doped with Ce(3+) phosphor exhibits great potential for use in white ultraviolet (UV) light-emitting diode applications to serve as a single-phased phosphor that can be pumped with near-UV or UV light-emitting diodes. Copyright © 2013 John Wiley & Sons, Ltd.

Tunable white light of a Ce3+,Tb3+,Mn2+ triply doped Na2Ca3Si2O8 phosphor for high colour-rendering white LED applications: tunable luminescence and energy transfer.

PubMed

Lü, Wei; Xu, Huawei; Huo, Jiansheng; Shao, Baiqi; Feng, Yang; Zhao, Shuang; You, Hongpeng

2017-07-18

A tunable white light emitting Na 2 Ca 3 Si 2 O 8 :Ce 3+ ,Tb 3+ ,Mn 2+ phosphor with a high color rendering index (CRI) has been prepared. Under UV excitation, Na 2 Ca 3 Si 2 O 8 :Ce 3+ phosphors present blue luminescence and exhibit a broad excitation ranging from 250 to 400 nm. When codoping Tb 3+ /Mn 2+ ions into Na 2 Ca 3 Si 2 O 8 , energy transfer from Ce 3+ to Tb 3+ and Ce 3+ to Mn 2+ ions is observed from the spectral overlap between Ce 3+ emission and Tb 3+ /Mn 2+ excitation spectra. The energy-transfer efficiencies and corresponding mechanisms are discussed in detail. The mechanism of energy transfer from Ce 3+ to Tb 3+ is demonstrated to be a dipole-quadrupole mechanism by the Inokuti-Hirayama model. The wavelength-tunable white light can be realized by coupling the emission bands centered at 440, 550 and 590 nm ascribed to the contribution from Ce 3+ , Tb 3+ and Mn 2+ , respectively. The commission on illumination value of color tunable emission can be tuned by controlling the content of Ce 3+ , Tb 3+ and Mn 2+ . Temperature-dependent luminescence spectra proved the good thermal stability of the as-prepared phosphor. White LEDs with CRI = 93.5 are finally fabricated using a 365 nm UV chip and the as-prepared Na 2 Ca 3 Si 2 O 8 :Ce 3+ ,Tb 3+ ,Mn 2+ phosphor. All the results suggest that Na 2 Ca 3 Si 2 O 8 :Ce 3+ ,Tb 3+ ,Mn 2+ can act as potential color-tunable and single-phase white emission phosphors for possible applications in UV based white LEDs.

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

Using elemental profiles and stable isotopes to trace the origin of green coffee beans on the global market.

PubMed

Santato, Alessandro; Bertoldi, Daniela; Perini, Matteo; Camin, Federica; Larcher, Roberto

2012-09-01

A broad elemental profile incorporating 54 elements (Li, Be, B, Na, Mg, Al, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Y, Mo, Pd, Ag, Cd, Sn, Sb, Te, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er, Tm, Yb, Re, Ir, Pt, Au, Hg, Tl, Pb, Bi and U) in combination with δ(2) H, δ(13) C, δ(15) N and δ(18) O was used to characterise the composition of 62 green arabica (Coffea arabica) and robusta (Coffea canephora) coffee beans grown in South and Central America, Africa and Asia, the four most internationally renowned areas of production. The δ(2) H, Mg, Fe, Co and Ni content made it possible to correctly assign 95% of green coffee beans to the appropriate variety. Canonical discriminant analysis, performed using δ(13) C, δ(15) N, δ(18) O, Li, Mg, P, K, Mn, Co, Cu, Se, Y, Mo, Cd, La and Ce correctly traced the origin of 98% of coffee beans. Copyright © 2012 John Wiley & Sons, Ltd.

Role of capsule endoscopy in suspected celiac disease: A European multi-centre study

PubMed Central

Luján-Sanchis, Marisol; Pérez-Cuadrado-Robles, Enrique; García-Lledó, Javier; Juanmartiñena Fernández, José-Francisco; Elli, Luca; Jiménez-García, Victoria-Alejandra; Egea-Valenzuela, Juan; Valle-Muñoz, Julio; Carretero-Ribón, Cristina; Fernández-Urién-Sainz, Ignacio; López-Higueras, Antonio; Alonso-Lázaro, Noelia; Sanjuan-Acosta, Mileidis; Sánchez-Ceballos, Francisco; Rosa, Bruno; González-Vázquez, Santiago; Branchi, Federica; Ruano-Díaz, Lucía; Prieto-de-Frías, César; Pons-Beltrán, Vicente; Borque-Barrera, Pilar; González-Suárez, Begoña; Xavier, Sofía; Argüelles-Arias, Federico; Herrerías-Gutiérrez, Juan-Manuel; Pérez-Cuadrado-Martínez, Enrique; Sempere-García-Argüelles, Javier

2017-01-01

AIM To analyze the diagnostic yield (DY), therapeutic impact (TI) and safety of capsule endoscopy (CE). METHODS This is a multi-centre, observational, analytical, retrospective study. A total of 163 patients with suspicion of celiac disease (CD) (mean age = 46.4 ± 17.3 years, 68.1% women) who underwent CE from 2003 to 2015 were included. Patients were divided into four groups: seronegative CD with atrophy (Group-I, n = 19), seropositive CD without atrophy (Group-II, n = 39), contraindication to gastroscopy (Group-III, n = 6), seronegative CD without atrophy, but with a compatible context (Group-IV, n = 99). DY, TI and the safety of CE were analysed. RESULTS The overall DY was 54% and the final diagnosis was villous atrophy (n = 65, 39.9%), complicated CD (n = 12, 7.4%) and other enteropathies (n = 11, 6.8%; 8 Crohn’s). DY for groups I to IV was 73.7%, 69.2%, 50% and 44.4%, respectively. Atrophy was located in duodenum in 24 cases (36.9%), diffuse in 19 (29.2%), jejunal in 11 (16.9%), and patchy in 10 cases (15.4%). Factors associated with a greater DY were positive serology (68.3% vs 49.2%, P = 0.034) and older age (P = 0.008). On the other hand, neither sex nor clinical presentation, family background, positive histology or HLA status were associated with DY. CE results changed the therapeutic approach in 71.8% of the cases. Atrophy was associated with a greater TI (92.3% vs 45.3%, P < 0.001) and 81.9% of the patients responded to diet. There was one case of capsule retention (0.6%). Agreement between CE findings and subsequent histology was 100% for diagnosing normal/other conditions, 70% for suspected CD and 50% for complicated CD. CONCLUSION CE has a high DY in cases of suspicion of CD and it leads to changes in the clinical course of the disease. CE is safe procedure with a high degree of concordance with histology and it helps in the differential diagnosis of CD. PMID:28216978

Pressure and temperature dependence of the Ce valence and c -f hybridization gap in Ce T2In5(T =Co ,Rh ,Ir ) heavy-fermion superconductors

NASA Astrophysics Data System (ADS)

Yamaoka, H.; Yamamoto, Y.; Schwier, E. F.; Honda, F.; Zekko, Y.; Ohta, Y.; Lin, J.-F.; Nakatake, M.; Iwasawa, H.; Arita, M.; Shimada, K.; Hiraoka, N.; Ishii, H.; Tsuei, K.-D.; Mizuki, J.

2015-12-01

Pressure- and temperature-induced changes in the Ce valence and c -f hybridization of the Ce115 superconductors have been studied systematically. Resonant x-ray-emission spectroscopy indicated that the increase of the Ce valence with pressure was significant for CeCoIn5, and moderate for CeIr (In0.925Cd0.075)5 . We found no abrupt change of the Ce valence in the Kondo regime for CeIr (In0.925Cd0.075)5 , which suggests that valence fluctuations are unlikely to mediate the superconductivity in this material. X-ray-diffraction results were consistent with the pressure-induced change in the Ce valence. High-resolution photoelectron spectroscopy revealed a temperature-dependent reduction of the spectral intensity at the Fermi level, indicating enhanced c -f hybridization on cooling.

Photocatalytic activity of binary metal oxide nanocomposites of CeO2/CdO nanospheres: Investigation of optical and antimicrobial activity.

PubMed

Magdalane, C Maria; Kaviyarasu, K; Vijaya, J Judith; Siddhardha, Busi; Jeyaraj, B

2016-10-01

We report the synthesis of high quality CeO2-CdO binary metal oxide nanocomposites were synthesized by a simple chemical precipitation and hydrothermal method. Cerium nitrate and cadmium nitrate were used as precursors. Composition, structure and morphology of the nanocomposites were analyzed by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). XRD pattern proves that the final product has cubic phase and the particle size diameter of the nanocomposites are 27nm, XRD results also indicated that the crystalline properties of the nanocomposite were improved without affecting the parent lattice, FESEM analysis indicates that the product is composed of spherical particles in clusters. The morphological and optical properties of CeO2-CdO nanosamples were characterized by HRTEM and DRS spectroscopy. The IR results showed high purity of products and indicated that the nanocomposites are made up of CeO2 and CdO bonds. Absorption spectra exhibited an upward shift in characteristic peaks caused by the addition of transition metal oxide, suggesting that crystallinity of both the metal oxide is improved due to specific doping level. TGA plots further confirmed the purity and stability of nanomaterials prepared. Hence the nanocomposite has cubic crystal lattice and form a homogeneous solid structure. From the result, Cd(2+) ions are embedded in the cubic crystal lattice of ceria. The growth rate increases which are ascribed to the cationic doping with a lower valence cation. Ce-Cd binary metal oxide nanocomposites showed antibacterial activity, it showed the better growth inhibition towards p.aeruginosa. Exploit of photodegradation and photocatalytic activity of large scale synthesis of CeO2-CdO binary metal oxide nanocomposites was reported. Copyright © 2016 Elsevier B.V. All rights reserved.

Tunable color and energy transfer in single-phase white-emitting Ca{sub 20}Al{sub 26}Mg{sub 3}Si{sub 3}O{sub 68}:Ce{sup 3+},Dy{sup 3+} phosphors for UV white light-emitting diodes

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

Yuan, Bo; Song, Yanhua; Sheng, Ye

Ce{sup 3+} and/or Dy{sup 3+} activated Ca{sub 20}Al{sub 26}Mg{sub 3}Si{sub 3}O{sub 68} phosphors were synthesized by high temperature solid state reaction and their luminescent properties were studied. There are two emissions peaking at 407 and 577 nm in the emission spectra of Ca{sub 20}Al{sub 26}Mg{sub 3}Si{sub 3}O{sub 68}:Ce{sup 3+}, Dy{sup 3+}, which are due to the transitions of Ce{sup 3+} and Dy{sup 3+} ions, respectively. More importantly, the effective energy transfer from Ce{sup 3+} to Dy{sup 3+} ions has been confirmed and investigated by emission/excitation spectra and luminescent decay behaviors. Furthermore, the energy level scheme and mechanism of energy transfermore » were investigated and it was demonstrated to be resonant type via dipole–dipole reaction. Under the excitation of 345 nm, the emitting color can change from blue to white by adjusting the relative doping concentration of Ce{sup 3+} and Dy{sup 3+} ions, indicating that the phosphors Ca{sub 20}Al{sub 26}Mg{sub 3}Si{sub 3}O{sub 68}:Ce{sup 3+}, Dy{sup 3+} are promising single-phase white-emitting phosphors for application in pc-white LEDs. - Highlights: • The Ca{sub 20}Al{sub 26}Mg{sub 3}Si{sub 3}O{sub 68}:Ce{sup 3+},Dy{sup 3+} are novel luminescent materials that have not been reported before. • The crystal structure of Ca{sub 20}Al{sub 26}Mg{sub 3}Si{sub 3}O{sub 68} and energy transfer from Ce{sup 3+} to Dy{sup 3+} were investigated. • The emission color of Ca{sub 20}Al{sub 26}Mg{sub 3}Si{sub 3}O{sub 68}:Ce{sup 3+},Dy{sup 3+} can be adjusted from blue to white. • The phosphors have great application value in WLEDs as a kind of blue-to-white emitting phosphors.« less

Evaluation of the Immunologic Impact of RAF Inhibitors to Guide Optimal Combination of RAF Inhibitors and Immunotherapy for the Treatment of Advanced Melanoma

DTIC Science & Technology

2016-03-01

TILS (Vehicle) Fr eq o f P ar en t CD4+ T cells CD4+CD25+Foxp3+ CD8+ CD8+PD1+ CD8+GrzB...PDL1+ CD 4+ T ce lls CD 4+ CD 25 +F ox p3 + CD 8+ CD 8+ PD 1+ CD 8+ Gr zB + CD 8+ Ki6 7+ 0 10 20 30 40 Day 5 - TILS (BRAFi) Fr eq o f P ar en t...ce lls CD 4+ CD 25 +F ox p3 + CD 8+ CD 8+ PD 1+ CD 8+ Gr zB + CD 8+ Ki6 7+ 0 10 20 30 40 Day 2 - TILS (Vehicle) Fr eq o f P ar en t CD4+ T cells

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.

Role of Ce4+ in the Scintillation Mechanism of Codoped Gd3Ga3Al2O12∶Ce

NASA Astrophysics Data System (ADS)

Wu, Yuntao; Meng, Fang; Li, Qi; Koschan, Merry; Melcher, Charles L.

2014-10-01

To control the time-response performance of widely used cerium-activated scintillators in cutting-edge medical-imaging devices, such as time-of-flight positron-emission tomography, a comprehensive understanding of the role of Ce valence states, especially stable Ce44, in the scintillation mechanism is essential. However, despite some progress made recently, an understanding of the physical processes involving Ce4+ is still lacking. The aim of this work is to clarify the role of Ce4+ in scintillators by studying Ca2+ codoped Gd3Ga3Al2O12∶Ce (GGAG ∶Ce). By using a combination of optical absorption spectra and x-ray absorption near-edge spectroscopies, the correlation between Ca2+ codoping content and the Ce4+ fraction is seen. The energy-level diagrams of Ce3+ and Ce4+ in the Gd3Ga3Al2O12 host are established by using theoretical and experimental methods, which indicate a higher position of the 5d1 state of Ce4+ in the forbidden gap in comparison to that of Ce3+. Underlying reasons for the decay-time acceleration resulting from Ca2+ codoping are revealed, and the physical processes of the Ce4+-emission model are proposed and further demonstrated by temperature-dependent radioluminescence spectra under x-ray excitation.

Relationship between domestic smoking and metals and rare earth elements concentration in indoor PM2.5.

PubMed

Drago, Gaspare; Perrino, Cinzia; Canepari, Silvia; Ruggieri, Silvia; L'Abbate, Luca; Longo, Valeria; Colombo, Paolo; Frasca, Daniele; Balzan, Martin; Cuttitta, Giuseppina; Scaccianoce, Gianluca; Piva, Giuseppe; Bucchieri, Salvatore; Melis, Mario; Viegi, Giovanni; Cibella, Fabio; Balzan, Martin; Bilocca, David; Borg, Charles; Montefort, Stephen; Zammit, Christopher; Bucchieri, Salvatore; Cibella, Fabio; Colombo, Paolo; Cuttitta, Giuseppina; Drago, Gaspare; Ferrante, Giuliana; L'Abbate, Luca; Grutta, Stefania La; Longo, Valeria; Melis, Mario R; Ruggieri, Silvia; Viegi, Giovanni; Minardi, Remo; Piva, Giuseppe; Ristagno, Rosaria; Rizzo, Gianfranco; Scaccianoce, Gianluca

2018-04-16

Cigarette smoke is the main source of indoor chemical and toxic elements. Cadmium (Cd), Thallium (Tl), Lead (Pb) and Antimony (Sb) are important contributors to smoke-related health risks. Data on the association between Rare Earth Elements (REE) Cerium (Ce) and Lanthanum (La) and domestic smoking are scanty. To evaluate the relationship between cigarette smoke, indoor levels of PM 2.5 and heavy metals, 73 children were investigated by parental questionnaire and skin prick tests. The houses of residence of 41 "cases" and 32 "controls" (children with and without respiratory symptoms, respectively) were evaluated by 48-h PM 2.5 indoor/outdoor monitoring. PM 2.5 mass concentration was determined by gravimetry; the extracted and mineralized fractions of elements (As, Cd, Ce, La, Mn, Pb, Sb, Sr, Tl) were evaluated by ICP-MS. PM 2.5 and Ce, La, Cd, and Tl indoor concentrations were higher in smoker dwellings. When corrected for confounding factors, PM 2.5 , Ce, La, Cd, and Tl were associated with more likely presence of respiratory symptoms in adolescents. We found that: i) indoor smoking is associated with increased levels of PM 2.5 , Ce, La, Cd, and Tl and ii) the latter with increased presence of respiratory symptoms in children. Copyright © 2018 Elsevier Inc. All rights reserved.

Increased expression of HOXB2 and HOXB13 proteins is associated with HPV infection and cervical cancer progression.

PubMed

Gonzalez-Herrera, Al; Salgado-Bernabe, M; Velazquez-Velazquez, Ck; Salcedo-Vargas, M; Andrade-Manzano, A; Avila-Moreno, F; Pina-Sanchez, P

2015-01-01

Cervical cancer (CeCa) is the second most common cancer in women in developing countries, and human papilloma virus (HPV) is the primary etiological factor. Aberrant expression of HOX transcription factors has been observed in several types of cancer. To date, however, no reports exist on the expression of HOXB2 and HOXB13 proteins during neoplastic progression in CeCa and its correlation with HPV infection. Expression of HOXB2 and HOXB13 proteins was assessed in tissue microarrays from normal cervical epithelium, cervical intraepithelial neoplasias grade 1-3, and CeCa. HPV was detected by PCR and sequencing. Expression of HOX-positive cells was determined in each diagnostic group. Percentage of HOXB2- and HOXB13-positive cells gradually increased from means of 10.9% and 16.7%, respectively, in samples from healthy women, to 75.2% and 88.6% in those from CeCa patients. Frequency of HPV infection also increased from 13% in healthy tissue samples to 92.3% in CeCa. Both HOXB2 and HOXB13 proteins were preferentially expressed in HPV+ samples. The present study represents the first report on the expression of both HOXB2 and HOXB13 proteins through cervix tumorigenesis, providing evidence that increased expression of such proteins is a common event during progression to CeCa.

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

Wen, Haiming; van Rooyen, Isabella J.

Here, detailed electron microscopy studies were performed to investigate the distribution and composition of fission products in the SiC layer of a tristructural isotropic coated particle exhibiting localized corrosion. Previous studies on this particle indicated that pure carbon areas in the SiC layer, resulting from localized corrosion of SiC by Pd, provide pathways for Ag, Cd and Cs migration. This study reveals the presence of Ag- and/or Cd-containing precipitates in un-corroded SiC areas. Ag/Cd may exist by themselves or coexist with Pd. Ag/Cd mainly transport along SiC grain boundaries. An Ag-Pd-Cd precipitate was identified at a stacking fault inside amore » SiC grain, suggesting that intragranular transport of Ag/Cd is possible. Ce is present with Pd or Pd-U in some precipitates >50 nm. U and Ce frequently coexist with each other, whereas Ag/Cd usually does not coexist with U or Ce. No Cs was detected in any precipitates in the areas examined.« less

Optical properties of white organic light-emitting devices fabricated utilizing a mixed CaAl12O19:Mn4+ and Y3Al5O12:Ce3+ color conversion layer.

PubMed

Jeong, H S; Kim, S H; Lee, K S; Jeong, J M; Yoo, T W; Kwon, M S; Yoo, K H; Kim, T W

2013-06-01

White organic light-emitting devices (OLEDs) were fabricated by combining a blue OLED with a color conversion layer made of mixed Y3Al5O12:Ce3+ green and Ca2AlO19:Mn4+ red phosphors. The X-ray diffraction patterns showed that Ce3+ ions in the Y3Al5O12:Ce3+ phosphors completely substituted for the Y3+ ions and the Mn4+ ions in the CaAl12O19:Mn4+ phosphors completely substituted for the Ca2+ ions. Electroluminescence spectra at 11 V for the OLEDs fabricated utilizing a color conversion layer showed that the Commission Internationale de l'Eclairage coordinates for the Y3Al5O12:Ce3+ and CaAl12O19:Mn4+ phosphors mixed at the ratio of 1:5 and 1:10 were (0.31, 0.34) and (0.32, 0.37), respectively, indicative of a good white color.

Investigation on microstructure characterization and property of rapidly solidified Mg-Zn-Ca-Ce-La alloys

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

Zhou Tao, E-mail: tzhou1118@163.com; Chen Zhenhua, E-mail: chenzhenhua45@hotmail.com; Yang Mingbo, E-mail: yangmingbo@cqit.edu.cn

2012-01-15

Rapidly solidified (RS) Mg-Zn-Ca-Ce-La (wt.%) alloys have been produced via atomizing the alloy melt and subsequent splat-quenching on the water-cooled copper twin-rollers in the form of flakes. Microstructure characterization, phase compositions and thermal stability of the alloys have been systematically investigated. The results showed that with addition of RE (Ce and La) to the Mg-6Zn-5Ca alloy, the stable intermetallic compounds i.e. the Mg{sub x}Zn{sub y}RE{sub z} phase with a few Ca (about 3 at.%), shortened as the T Prime phase, were formed at the expense of the binary Mg-Zn and Ca{sub 2}Mg{sub 6}Zn{sub 3} phases, which was possibly beneficial tomore » the enhanced thermal stability of the alloy. In the Mg-6Zn-5Ca-3Ce-0.5La alloy, the composition of the T Prime phase in the grain interior was different from that at the grain boundaries, in which the segregation of the La elements was found, and the atomic percentage ratio of Zn to Ce in the T Prime phase within the grains was close to 2. Moreover, the stable Mg{sub 2}Ca phases were detected around the T Prime phases at the grain boundaries in the alloy. - Research Highlights: Black-Right-Pointing-Pointer The phase constitution of RS Mg-6Zn-5Ca alloy can be improved by RE additions. Black-Right-Pointing-Pointer In the Mg-Zn-Ca-Ce-La alloys, the Mg{sub x}Zn{sub y}RE{sub z} phase with a few Ca (T Prime phase) is formed. Black-Right-Pointing-Pointer The formation of the T Prime phase leads to the loss of the Mg-Zn and Ca{sub 2}Mg{sub 6}Zn{sub 3} phases. Black-Right-Pointing-Pointer The composition of the T Prime phase differs from the grain interior to the grain boundary.« less

Role of Ce 4 + in the scintillation mechanism of codoped Gd 3 Ga 3 Al 2 O 12 : Ce

DOE PAGES

Wu, Yuntao; Meng, Fang; Li, Qi; ...

2014-10-17

To control the time-response performance of widely used cerium-activated scintillators in cutting-edge medical-imaging devices, such as time-of-flight positron-emission tomography, a comprehensive understanding of the role of Ce valence states, especially stable Ce 4+, in the scintillation mechanism is essential. However, despite some progress made recently, an understanding of the physical processes involving Ce 4+ is still lacking. The aim of this work is to clarify the role of Ce 4+ in scintillators by studying Ca 2+ codoped Gd 3Ga 3Al 2O1 2∶Ce (GGAG∶Ce). By using a combination of optical absorption spectra and x-ray absorption near-edge spectroscopies, the correlation between Ca 2+codopingmore » content and the Ce 4+ fraction is seen. The energy-level diagrams of Ce 3+ and Ce 4+ in the Gd 3Ga 3Al 2O 12 host are established by using theoretical and experimental methods, which indicate a higher position of the 5d 1 state of Ce 4+ in the forbidden gap in comparison to that of Ce 3+. Underlying reasons for the decay-time acceleration resulting from Ca 2+ codoping are revealed, and the physical processes of the Ce 4+-emission model are proposed and further demonstrated by temperature-dependent radioluminescence spectra under x-ray excitation.« less

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.

Pregnancy outcomes in women with chronic endometritis and recurrent pregnancy loss.

PubMed

McQueen, Dana B; Perfetto, Candice O; Hazard, Florette K; Lathi, Ruth B

2015-10-01

To evaluate the prevalence of chronic endometritis (CE) in women with recurrent pregnancy loss (RPL) and compare pregnancy outcomes in women with and without CE. Case-control observational study. Academic fertility practice. Women with two or more pregnancy losses. Hematoxylin and eosin (H & E) staining was performed on all endometrial biopsies and plasma cells were identified by morphology. Immunohistochemical (IHC) staining for CD138 was later applied to all tissue samples. Charts were reviewed to evaluate the outcome of the next clinical intrauterine pregnancy. Miscarriage rate and live birth rate. A total of 107 women met inclusion criteria. The use of CD138 IHC staining resulted in a significantly higher prevalence of CE compared with the use of H & E staining and morphological assessment alone (56% [60/107] vs. 13% [14/107]). The 51 women with untreated CE were compared with the 45 women without CE by CD138 staining. Among those women with a subsequent pregnancy, the live birth rate in the next clinical intrauterine pregnancy after endometrial evaluation was 67.6% (23/34) in women with untreated CE and 87.1% (27/31) in women without CE. Age, body mass index (BMI), results of RPL evaluation, and number of prior losses were not significantly different between the two groups. CD138 IHC staining of endometrial biopsies in women with RPL provides increased sensitivity when screening for CE compared with H & E staining and morphological assessment alone. Untreated CE may contribute to poor pregnancy outcomes and deserves further investigation in a larger cohort. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Contrast-enhanced transrectal ultrasound (CE-TRUS) with cadence-contrast pulse sequence (CPS) technology for the identification of prostate cancer.

PubMed

Seitz, Michael; Gratzke, Christian; Schlenker, Boris; Buchner, Alexander; Karl, Alexander; Roosen, Alexander; Singer, Bernhard B; Bastian, Patrick J; Ergün, Süleyman; Stief, Christian G; Reich, Oliver; Tilki, Derya

2011-01-01

Various imaging modalities, such as magnetic resonance imaging (MRI), have been assessed with regard to their value in the detection of prostate cancer (CaP). However, there is a need for less time-consuming and more cost effective procedures in urology. In order to determine the ability of contrast-enhanced transrectal ultrasound (CE-TRUS) to identify CaP, we investigated patients scheduled for radical prostatectomy for CaP and radical cystoprostatectomy for bladder cancer. Between May and August 2008, 35 consecutive patients with CaP and muscle-invasive bladder carcinoma were prospectively enrolled in this single center study. All patients underwent B-mode TRUS and CE-TRUS (Sequoia 512 unit with an endocavity probe EV8C4, 8 MHz; Siemens, Erlangen, Germany) by one investigator blinded to any clinical data before radical surgery. Contrast-enhanced images were obtained after intravenous infusion of a bolus (2.4 ml) of the contrast agent SonoVue (Bracco, Milan, Italy). Ultrasound findings (CE-TRUS and B-mode TRUS) were correlated with step-section histology. On a per-patient basis, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for detecting CaP with CE-TRUS were 71.0%, 50.0%, 91.7%, and 18.2%, respectively. In comparison with B-mode TRUS (sensitivity 45.2%, specificity 75.0%, PPV 93.3%, and NPV 18.0%), CE-TRUS performed significantly better (P=0.004, McNemar test). On a per-prostate-lobe basis sensitivity, specificity, PPV, and NPV were 69.0%, 33.3%, 83.3%, and 18.2%. CE-TRUS detected prostate cancer with a modest sensitivity and a high PPV in a selected patient cohort. Future randomized-controlled multicenter studies are needed to further validate the value of CE-TRUS in the detection of CaP. Based on our results, CE-TRUS may not be recommended as a routine procedure in the diagnosis of CaP at present. Copyright © 2011 Elsevier Inc. All rights reserved.

Luminescence and energy transfer properties of Ca2Ba3(PO4)3Cl and Ca2Ba3(PO4)3Cl:A (A = Eu2+/Ce3+/Dy3+/Tb3+) under UV and low-voltage electron beam excitation.

PubMed

Shang, Mengmeng; Geng, Dongling; Yang, Dongmei; Kang, Xiaojiao; Zhang, Yang; Lin, Jun

2013-03-18

Pure Ca2Ba3(PO4)3Cl and rare earth ion (Eu(2+)/Ce(3+)/Dy(3+)/Tb(3+)) doped Ca2Ba3(PO4)3Cl phosphors with the apatite structure have been prepared via a Pechini-type sol-gel process. X-ray diffraction (XRD) and structure refinement, photoluminescence (PL) spectra, cathodoluminescence (CL) spectra, absolute quantum yield, as well as lifetimes were utilized to characterize samples. Under UV light excitation, the undoped Ca2Ba3(PO4)3Cl sample shows broad band photoluminescence centered near 480 nm after being reduced due to the defect structure. Eu(2+) and Ce(3+) ion doped Ca2Ba3(PO4)3Cl samples also show broad 5d → 4f transitions with cyan and blue colors and higher quantum yields (72% for Ca2Ba3(PO4)3Cl:0.04Eu(2+); 67% for Ca2Ba3(PO4)3Cl:0.016Ce(3+)). For Dy(3+) and Tb(3+) doped Ca2Ba3(PO4)3Cl samples, they give strong line emissions coming from 4f → 4f transitions. Moreover, the Ce(3+) ion can transfer its energy to the Tb(3+) ion in the Ca2Ba3(PO4)3Cl host, and the energy transfer mechanism has been demonstrated to be a resonant type, via a dipole-quadrupole interaction. However, under the low voltage electron beam excitation, Tb(3+) ion doped Ca2Ba3(PO4)3Cl samples present different luminescence properties compared with their PL spectra, which is ascribed to the different excitation mechanism. On the basis of the good PL and CL properties of the Ca2Ba3(PO4)3Cl:A (A = Ce(3+)/Eu(2+)/Tb(3+)/Dy(3+)), Ca2Ba3(PO4)3Cl might be promising for application in solid state lighting and field-emission displays.

Weak hybridization and isolated localized magnetic moments in the compounds CeT 2Cd 20 (T = Ni, Pd)

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

White, B. D.; Yazici, D.; Ho, P. -C.

2015-07-20

Here, we report the physical properties of single crystals of the compounds CeT 2Cd 20 (T = Ni, Pd) that were grown in a molten Cd flux. Large separations of ~6.7- 6.8 Å between Ce ions favor the localized magnetic moments that are observed in measurements of the magnetization. The strength of the Ruderman-Kittel-Kasuya- Yosida magnetic exchange interaction between the localized moments is severely limited by the large Ce-Ce separations and by weak hybridization between localized Ce 4f and itinerant electron states. Measurements of electrical resistivity performed down to 0.138 K were unable to observe evidence for the emergence ofmore » magnetic order; however, magnetically-ordered ground states with very low transition temperatures are still expected in these compounds despite the isolated nature of the localized magnetic moments. Such a fragile magnetic order could be highly susceptible to tuning via applied pressure, but evidence for the emergence of magnetic order has not been observed so far in our measurements up to 2.5 GPa.« less

Effects of (LiCe) co-substitution on the structural and electrical properties of CaBi2Nb2O9 ceramics

NASA Astrophysics Data System (ADS)

Tian, Xiao-Xia; Qu, Shao-Bo; Du, Hong-Liang; Li, Ye; Xu, Zhuo

2012-03-01

The piezoelectric, dielectric, and ferroelectric properties of the (LiCe) co-substituted calcium bismuth niobate (CaBi2Nb2O9, CBNO) are investigated. The piezoelectric properties of CBNO ceramics are significantly enhanced and the dielectric loss tan δ decreased. This makes poling using (LiCe) co-substitution easier. The ceramics (where □ represents A-site Ca2+ vacancies, possess a pure layered structure phase and no other phases can be found. The Ca0.88(LiCe)0.04□0.04Bi2Nb2O9 ceramics possess optimal piezoelectric properties, with piezoelectric coefficient (d33) and Curie temperature (TC) found to be 13.3 pC/N and 960 °C, respectively. The dielectric and piezoelectric properties of the (LiCe) co-substituted CBNO ceramics exhibit very stable temperature behaviours. This demonstrates that the CBNO ceramics are a promising candidate for ultrahigh temperature applications.

Improved hole-injection and power efficiency of organic light-emitting diodes using an ultrathin cerium fluoride buffer layer

NASA Astrophysics Data System (ADS)

Lu, Hsin-Wei; Kao, Po-Ching; Chu, Sheng-Yuan

2016-09-01

In this study, the efficiency of organic light-emitting diodes (OLEDs) was enhanced by depositing a CeF3 film as an ultra-thin buffer layer between the ITO and NPB hole transport layer, with the structure configuration ITO/CeF3 (1 nm)/NPB (40 nm)/Alq3 (60 nm)/LiF (1 nm)/Al (150 nm). The enhancement mechanism was systematically investigated via several approaches. The work function increased from 4.8 eV (standard ITO electrode) to 5.2 eV (1-nm-thick UV-ozone treated CeF3 film deposited on the ITO electrode). The turn-on voltage decreased from 4.2 V to 4.0 V at 1 mA/cm2, the luminance increased from 7588 cd/m2 to 10820 cd/m2, and the current efficiency increased from 3.2 cd/A to 3.5 cd/A when the 1-nm-thick UV-ozone treated CeF3 film was inserted into the OLEDs.

Evolution of ground-state wave function in CeCoIn 5 upon Cd or Sn doping

DOE PAGES

Chen, K.; Strigari, F.; Sundermann, M.; ...

2018-01-17

We present linear polarization-dependent soft-x-ray absorption spectroscopy data at the Ce M 4,5 edges of Cd- and Sn-doped CeCoIn 5. The 4f ground-state wave functions have been determined for their superconducting, antiferromagnetic, and paramagnetic ground states. The absence of changes in the wave functions in CeCo (In 1- xCd x) 5 suggests that the 4f-conduction-electron (c f) hybridization is not affected by global Cd doping, thus supporting the interpretation of magnetic droplets nucleating long-range magnetic order. This is contrasted by changes in the wave function due to Sn substitution. Increasing Sn in CeCo (In 1 - ySn y) 5 compressesmore » the 4f orbitals into the tetragonal plane of these materials, suggesting enhanced c f hybridization with the in-plane In(1) atoms and a homogeneous altering of the electronic structure. As these experiments show, the 4 f wave functions are a very sensitive probe of small changes in the hybridization of 4f and conduction electrons, even conveying information about direction dependencies.« less

Evolution of ground-state wave function in CeCoIn 5 upon Cd or Sn doping

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

Chen, K.; Strigari, F.; Sundermann, M.

We present linear polarization-dependent soft-x-ray absorption spectroscopy data at the Ce M 4,5 edges of Cd- and Sn-doped CeCoIn 5. The 4f ground-state wave functions have been determined for their superconducting, antiferromagnetic, and paramagnetic ground states. The absence of changes in the wave functions in CeCo (In 1- xCd x) 5 suggests that the 4f-conduction-electron (c f) hybridization is not affected by global Cd doping, thus supporting the interpretation of magnetic droplets nucleating long-range magnetic order. This is contrasted by changes in the wave function due to Sn substitution. Increasing Sn in CeCo (In 1 - ySn y) 5 compressesmore » the 4f orbitals into the tetragonal plane of these materials, suggesting enhanced c f hybridization with the in-plane In(1) atoms and a homogeneous altering of the electronic structure. As these experiments show, the 4 f wave functions are a very sensitive probe of small changes in the hybridization of 4f and conduction electrons, even conveying information about direction dependencies.« less

Improvement of Corrosion Resistance of Binary Mg-Ca Alloys Using Duplex Aluminum-Chromium Coatings

NASA Astrophysics Data System (ADS)

Daroonparvar, Mohammadreza; Yajid, Muhamad Azizi Mat; Yusof, Noordin Mohd; Bakhsheshi-Rad, Hamid Reza; Adabi, Mohsen; Hamzah, Esah; Kamali, Hussein Ali

2015-07-01

Al-AlCr was coated on Mg-Ca and Mg-Zn-Ce-La alloys using physical vapor deposition method. The surface morphology of the specimens was characterized by x-ray diffraction, scanning electron microscopy equipped with energy-dispersive x-ray spectroscopy, and atomic force microscopy (AFM). The AFM results indicated that the average surface roughness of Al-AlCr coating on the Mg-Ca alloy is much lower than that of Al-AlCr coating on the Mg-Zn-Ce-La alloy. However, Al-AlCr coating on the Mg-Ca alloy presented a more compact structure with fewer pores, pinholes, and cracks than Al-AlCr coating on the Mg-Zn-Ce-La alloy. Electrochemical studies revealed that the novel coating (Al-AlCr) can remarkably reduce the corrosion rate of the Mg-Ca alloy in 3.5 wt.% NaCl solution. It was seen that the anodic current density of the Al-AlCr-coated Mg-Ca alloy was very small when compared to the Al-AlCr-coated Mg-Zn-Ce-La and uncoated alloys. Impedance modulus ( Z) of the Al-AlCr-coated samples was higher than that of the bare Mg alloys. Z of Al-AlCr-coated Mg-Ca alloy was higher than that of the Al-AlCr-coated Mg-Zn-Ce-La alloy at low frequency.

Impact of gadolinium-based contrast agent in the assessment of Crohn's disease activity: Is contrast agent injection necessary?

PubMed

Quaia, Emilio; Sozzi, Michele; Gennari, Antonio Giulio; Pontello, Michele; Angileri, Roberta; Cova, Maria Assunta

2016-03-01

To determine whether magnetic resonance enterography (MRE) performed without intravenous contrast injection is diagnostically noninferior to conventional contrast-enhanced MRE (CE-MRE) in patients with Crohn's disease (CD). This was an Institutional Review Board (IRB)-approved retrospective study. Ninety-six patients (52 male and 44 female; 47.18 years ± 13.6) with a diagnosis of CD underwent MRE at 1.5T including T2 -weighted single-shot turbo-spin-echo, T2 -weighted spectral fat presaturation with inversion recovery (SPAIR), T1 -weighted balanced fast-field-echo MR sequences, and CE-MRE consisting in T1 -weighted breath-hold THRIVE 3D MRI sequences after administration of gadobenate dimeglumine (0.2 mL/kg of body weight). Unenhanced MRE, CE-MRE, and unenhanced MRE plus CE-MRE were reviewed in separate sessions with blinding by two readers in consensus, and subsequently by two other readers independently considering a subgroup of 20 patients. Crohn's Disease Endoscopic Index of Severity (CDEIS) and/or histologic analysis of the surgical specimen were considered as reference standards for the assessment of inflammatory activity. Patients revealed prevalently active (n = 55 patients) or quiescent CD (n = 41 patients). The agreement between unenhanced MRE vs. CE-MRE in interpreting active bowel inflammation was 96% (123/128 bowel segments; one-sided 95% confidence interval [CI], >94.4%). Unenhanced MRE vs. CE-MRE vs. unenhanced MRE plus CE-MRE revealed a diagnostic accuracy of 93% [90/96] vs. 92% [88/96] vs. 97% [93/96] (P > 0.05) in the diagnosis of active CD. Interreader agreement was very good for all variables (κ value = 0.8-0.9) except for the measurement of the length of disease (κ value = 0.45). Unenhanced MRE was noninferior to CE-MRE in diagnosing active inflammation in patients with CD. © 2015 Wiley Periodicals, Inc.

Capsule endoscopy in Crohn’s disease: Are we seeing any better?

PubMed Central

Hudesman, David; Mazurek, Jonathan; Swaminath, Arun

2014-01-01

Crohn’s disease (CD) is a complex, immune-mediated disorder that often requires a multi-modality approach for optimal diagnosis and management. While traditional methods include ileocolonoscopy and radiologic modalities, increasingly, capsule endoscopy (CE) has been incorporated into the algorithm for both the diagnosis and monitoring of CD. Multiple studies have examined the utility of this emerging technology in the management of CD, and have compared it to other available modalities. CE offers a noninvasive approach to evaluate areas of the small bowel that are difficult to reach with traditional endoscopy. Furthermore, CE maybe favored in specific sub segments of patients with inflammatory bowel disease (IBD), such as those with IBD unclassified (IBD-U), pediatric patients and patients with CD who have previously undergone surgery. PMID:25278698

Pediatric capsule endoscopy: review of the small bowel and patency capsules.

PubMed

Cohen, Stanley A; Ephrath, Hagit; Lewis, Jeffery D; Klevens, Alan; Bergwerk, Ari; Liu, Steven; Patel, Dinesh; Reed-Knight, Bonney; Stallworth, Angela; Wakhisi, Tamara; Gold, Benjamin D

2012-03-01

Because capsule endoscopy (CE) avoids ionizing radiation, deep sedation, and general anesthesia, CE may be valuable in pediatrics. We report a single pediatric center's experience with the use and safety of CE. In a retrospective review of consecutive CE studies, 284 CE studies were performed in 277 patients with a mean age of 15 (±3.7) years during a 5-year period. The youngest to swallow the capsule was 4.6 years old. Twenty capsules were placed. Overall, 245 (86%) patients underwent CE for suspected (184, 65%) or confirmed (61, 21%) Crohn disease (CD); 27 (9.5%) anemia or gastrointestinal bleeding; 6 (2%) polyposis; and 4 (1.4%) celiac disease. Positive findings were observed in 205 (72%) of the studies, with 152 (54%) having small bowel findings. Of these, 72 (47%) were diagnostic. Gastric (95, 33%) and colonic (31, 11%) abnormalities were also identified. Five CE studies (1.8%) resulted in retention of the capsule in nonsurgical patients. A patency capsule before CE in 23 patients allowed 19 CE to proceed with only 1 retained capsule. In 65 (21%) patients, the video capsule did not enter the colon before the video's end. Of these, 36 (65%) had significant findings, including 27 (49%) documenting small bowel (SB) CD. CE is useful to diagnose SB disease in children. Even in a study population with a high prevalence of confirmed and suspected CD, the risk of retention remains small. The patency capsule may lessen that risk. CE may identify gastric or colonic disease even when SB lesions are not present.

Ternary rare earth sulfide CaCe2S4: Synthesis and characterization of stability, structure, and photoelectrochemical properties in aqueous media

NASA Astrophysics Data System (ADS)

Sotelo, Paola; Orr, Melissa; Galante, Miguel Tayar; Hossain, Mohammad Kabir; Firouzan, Farinaz; Vali, Abbas; Li, Jun; Subramanian, Mas; Longo, Claudia; Rajeshwar, Krishnan; Macaluso, Robin T.

2018-06-01

A red-orange rare earth ternary chalcogenide, CaCe2S4, was prepared in powder form by solid-state synthesis. The structural details of this compound were determined by powder X-ray diffraction. The optical band gap of CaCe2S4 was determined by diffuse reflectance spectroscopy (DRS) to be 2.1 eV, consistent with the observed red-orange color. Quantitative colorimetry measurements also support the observed color and band gap of CaCe2S4. Both direct and indirect optical transitions were gleaned from Tauc analyses of the DRS data. Photoelectrochemistry experiments on CaCe2S4 films showed n-type semiconductor behavior. Analyses of these data via the Butler-Gärtner model afforded a flat-band potential of - 0.33 V (vs. Ag/AgCl/KCl 4 M) in pH 9 aqueous sulfite electrolyte. The potential and limitations of this material for solar water splitting and photocatalytic environmental remediation (e.g., dye photodegradation) are finally presented against the backdrop of its photoelectrochemical stability and surface hole transfer kinetics in aqueous electrolytes.

Polymorphic Transitions in Cerium-Substituted Zirconolite (CaZrTi 2O 7)

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

Clark, Braeden M.; Sundaram, S. K.; Misture, Scott T.

Compounds with the formulae CaZr 1–xCe xTi 2O 7 with x = 0.1–0.5 were synthesized by solid state reaction. Cerium was used as a surrogate for actinide elements. A transition from the 2M polymorph to the 4M polymorph (expanded unit cell due to cation ordering) in zirconolite was observed with increasing cerium content. The presence of both tri- and tetravalent Ce, contrary to formulation, was confirmed using X-ray absorption near edge spectroscopy, suggesting substitution on both Ca and Zr sites. Sintering was carried out via spark plasma sintering, during which the perovskite phase (Ca 0.4Ce 0.4TiO 3) was stabilized duemore » to the reducing conditions of this technique. Scanning electron microscopy and energy dispersive spectrometry revealed that the 2M polymorph was dilute in Ce content in comparison to the 4M-zirconolite. High temperature X-ray diffraction was used to detail the kinetics of perovskite to zirconolite transition. It was found that CaCeTi 2O 7 (cubic pyrochlore) formed as an intermediate phase during the transition. Lastly, our results show that a transition from 2M- to 4M-zirconolite occurs with increasing Ce content and can be controlled by adjusting the P O2 and the heat treatment temperature.« less

Non-proportionality study of CaMoO4 and GAGG:Ce scintillation crystals using Compton coincidence technique.

PubMed

Kaewkhao, J; Limkitjaroenporn, P; Chaiphaksa, W; Kim, H J

2016-09-01

In this study, the CCT technique and nuclear instrument module (NIM) setup for the measurements of coincidence electron energy spectra of calcium molybdate (CaMoO4) and cerium doped gadolinium aluminium gallium garnet (Gd3Al2Ga3O12:Ce or GAGG:Ce) scintillation crystals were carried out. The (137)Cs irradiated gamma rays with an energy (Eγ) of 662keV was used as a radioactive source. The coincidence electron energy spectra were recorded at seven scattering angles of 30°-120°. It was found that seven corresponding electron energies were in the range of 100.5-435.4keV. The results show that, for all electron energies, the electron energy peaks of CaMoO4 crystal yielded higher number of counts than those of GAGG:Ce crystal. The electron energy resolution, the light yield and non-proportionality were also determined. It was found that the energy resolutions are inverse proportional to the square root of electron energy for both crystals. Furthermore, the results show that the light yield of GAGG:Ce crystal is much higher than that of CaMoO4 crystal. It was also found that both CaMoO4 and GAGG:Ce crystals demonstrated good proportional property in the electron energy range of 260-435.4keV. Copyright © 2016 Elsevier Ltd. All rights reserved.

Polymorphic Transitions in Cerium-Substituted Zirconolite (CaZrTi 2O 7)

DOE PAGES

Clark, Braeden M.; Sundaram, S. K.; Misture, Scott T.

2017-07-19

Compounds with the formulae CaZr 1–xCe xTi 2O 7 with x = 0.1–0.5 were synthesized by solid state reaction. Cerium was used as a surrogate for actinide elements. A transition from the 2M polymorph to the 4M polymorph (expanded unit cell due to cation ordering) in zirconolite was observed with increasing cerium content. The presence of both tri- and tetravalent Ce, contrary to formulation, was confirmed using X-ray absorption near edge spectroscopy, suggesting substitution on both Ca and Zr sites. Sintering was carried out via spark plasma sintering, during which the perovskite phase (Ca 0.4Ce 0.4TiO 3) was stabilized duemore » to the reducing conditions of this technique. Scanning electron microscopy and energy dispersive spectrometry revealed that the 2M polymorph was dilute in Ce content in comparison to the 4M-zirconolite. High temperature X-ray diffraction was used to detail the kinetics of perovskite to zirconolite transition. It was found that CaCeTi 2O 7 (cubic pyrochlore) formed as an intermediate phase during the transition. Lastly, our results show that a transition from 2M- to 4M-zirconolite occurs with increasing Ce content and can be controlled by adjusting the P O2 and the heat treatment temperature.« less

Identifying motor and sensory myelinated axons in rabbit peripheral nerves by histochemical staining for carbonic anhydrase and cholinesterase activities

NASA Technical Reports Server (NTRS)

Riley, Danny A.; Sanger, James R.; Matloub, Hani S.; Yousif, N. John; Bain, James L. W.

1988-01-01

Carbonic anhydrase (CA) and cholinesterase (CE) histochemical staining of rabbit spinal nerve roots and dorsal root ganglia demonstrated that among the reactive myeliated axons, with minor exceptions, sensory axons were CA positive and CE negative whereas motor axons were CA negative and CE positive. The high specificity was achieved by adjusting reaction conditions to stain subpopulations of myelinated axons selectively while leaving 50 percent or so unstained. Fixation with glutaraldehyde appeared necessary for achieving selectivity. Following sciatic nerve transection, the reciprocal staining pattern persisted in damaged axons and their regenerating processes which formed neuromas within the proximal nerve stump. Within the neuromas, CA-stained sensory processes were elaborated earlier and in greater numbers than CE-stained regenerating motor processes. The present results indicate that histochemical axon typing can be exploited to reveal heterogeneous responses of motor and sensory axons to injury.

Cordycepin-enriched WIB801C from Cordyceps militaris inhibits ADP-induced [Ca(2+)] i mobilization and fibrinogen binding via phosphorylation of IP 3R and VASP.

PubMed

Lee, Dong-Ha; Kwon, Hyuk-Woo; Kim, Hyun-Hong; Lim, Deok Hwi; Nam, Gi Suk; Shin, Jung-Hae; Kim, Yun-Yi; Kim, Jong-Lae; Lee, Jong-Jin; Kwon, Ho-Kyun; Park, Hwa-Jin

2015-01-01

In this study, we investigated the effect of cordycepin-enriched (CE)-WIB801C from Cordyceps militaris on ADP (20 µM)-stimulated platelet aggregation. CE-WIB801C dose-dependently inhibited ADP-induced platelet aggregation, and its IC50 value was 18.5 μg/mL. CE-WIB801C decreased TXA2 production, but did not inhibit the activities of COX-1 and thromboxane synthase (TXAS) in ADP-activated platelets, which suggests that the inhibition of TXA2 production by CE-WIB801C is not resulted from the direct inhibition of COX-1 and TXAS. CE-WIB801C inhibited ATP release and [Ca(2+)]i mobilization, and increased cAMP level and IP3RI (Ser(1756)) phosphorylation in ADP-activated platelets. cAMP-dependent protein kinase (A-kinase) inhibitor Rp-8-Br-cAMPS increased CE-WIB801C-inhibited [Ca(2+)]i mobilization, and strongly inhibited CE-WIB801C-increased IP3RI (Ser(1756)) phosphorylation. CE-WIB801C elevated the phosphorylation of VASP (Ser(157)), an A-kinase substrate, but inhibited fibrinogen binding to αIIb/β3. These results suggest that CE-WIB801C-elevated cAMP involved in IP3RI (Ser(1756)) phosphorylation to inhibit [Ca(2+)]i mobilization and, VASP (Ser(157)) phosphorylation to inhibit αIIb/β3 activation. Therefore, in this study, we demonstrate that CE-WIB801C may have a preventive or therapeutic potential for platelet aggregation-mediated diseases, such as thrombosis, myocardial infarction, atherosclerosis, and ischemic cerebrovascular disease.

Vegetation and landscape dynamics under natural and anthropogenic forcing on the Azores Islands: A 700-year pollen record from the São Miguel Island

NASA Astrophysics Data System (ADS)

Rull, Valentí; Lara, Arantza; Rubio-Inglés, María Jesús; Giralt, Santiago; Gonçalves, Vítor; Raposeiro, Pedro; Hernández, Armand; Sánchez-López, Guiomar; Vázquez-Loureiro, David; Bao, Roberto; Masqué, Pere; Sáez, Alberto

2017-03-01

The Azores archipelago has provided significant clues to the ecological, biogeographic and evolutionary knowledge of oceanic islands. Palaeoecological records are comparatively scarce, but they can provide relevant information on these subjects. We report the palynological reconstruction of the vegetation and landscape dynamics of the São Miguel Island before and after human settlement using the sediments of Lake Azul. The landscape was dominated by dense laurisilvas of Juniperus brevifolia and Morella faya from ca. 1280 CE to the official European establishment (1449 CE). After this date, the original forests were replaced by a complex of Erica azorica/Myrsine africana forests/shrublands and grassy meadows, which remained until ca. 1800 CE. Extractive forestry, cereal cultivation (rye, maize, wheat) and animal husbandry progressed until another extensive deforestation (ca. 1774 CE), followed by the large-scale introduction (1845 CE) of the exotic forest species Cryptomeria japonica and Pinus pinaster, which shaped the present-day landscape. Fire was a significant driver in these vegetation changes. The lake levels experienced a progressive rise during the time interval studied, reaching a maximum by ca. 1778-1852 CE, followed by a hydrological decline likely due to a combination of climatic and anthropogenic drivers. Our pollen record suggests that São Miguel were already settled by humans by ca. 1287 CE, approximately one century and a half prior to the official historically documented occupation of the archipelago. The results of this study are compared with the few palynological records available from other Azores islands (Pico and Flores).

Highly aqueous soluble CaF2:Ce/Tb nanocrystals: effect of surface functionalization on structural, optical band gap, and photoluminescence properties.

PubMed

Ansari, Anees A; Parchur, Abdul K; Kumar, Brijesh; Rai, S B

2016-12-01

The design of nanostructured materials with highly stable water-dispersion and luminescence efficiency is an important concern in nanotechnology and nanomedicine. In this paper, we described the synthesis and distinct surface modification on the morphological structure and optical (optical absorption, band gap energy, excitation, emission, decay time, etc.) properties of highly crystalline water-dispersible CaF 2 :Ce/Tb nanocrystals (core-nanocrystals). The epitaxial growth of inert CaF 2 and silica shell, respectively, on their surface forming as CaF 2 :Ce/Tb@CaF 2 (core/shell) and CaF 2 :Ce/Tb@CaF 2 @SiO 2 (core/shell/SiO 2 ) nanoarchitecture. X-ray diffraction and transmission electron microscope image shows that the nanocrystals were in irregular spherical phase, highly crystalline (~20 nm) with narrow size distribution. The core/shell nanocrystals confirm that the surface coating is responsible in the change of symmetrical nanostructure, which was determined from the band gap energy and luminescent properties. It was found that an inert inorganic shell formation effectively enhances the luminescence efficiency and silica shell makes the nanocrystals highly water-dispersible. In addition, Ce 3+ /Tb 3+ -co-doped CaF 2 nanocrystals show efficient energy transfer from Ce 3+ to Tb 3+ ion and strong green luminescence of Tb 3+ ion at 541 nm( 5 D 4 → 7 F 5 ). Luminescence decay curves of core and core/shell nanocrystals were fitted using mono and biexponential equations, and R 2 regression coefficient criteria were used to discriminate the goodness of the fitted model. The lifetime values for the core/shell nanocrystals are higher than core-nanocrystals. Considering the high stable water-dispersion and intensive luminescence emission in the visible region, these luminescent core/shell nanocrystals could be potential candidates for luminescent bio-imaging, optical bio-probe, displays, staining, and multianalyte optical sensing. A newly designed CaF 2 :Ce/Tb nanoparticles via metal complex decomposition rout shows high dispersibility in aqueous solvents with enhanced photoluminescence. The epitaxial growth of inert CaF 2 shell and further amorphous silica, respectively, enhanced their optical and luminescence properties, which is highly usable for luminescent biolabeling, and optical bioprobe etc.

Role of dimensionality in the Kondo Ce T X2 family: The case of CeCd0.7Sb2

NASA Astrophysics Data System (ADS)

Rosa, P. F. S.; Bourg, R. J.; Jesus, C. B. R.; Pagliuso, P. G.; Fisk, Z.

2015-10-01

Motivated by the presence of competing magnetic interactions in the heavy fermion family Ce T X2 (T = transitionmetal, X =pnictogen), here we study the novel parent compound CeCd0.7Sb2 by combining magnetization, electrical resistivity, and heat-capacity measurements. Contrary to the antiferromagnetic (AFM) ground state observed in most members of this family, the magnetic properties of our CeCd0.7Sb2 single crystals revealed a ferromagnetic ordering at Tc=3 K with an unusual soft behavior. By using a mean field model including anisotropic nearest-neighbor interactions and the tetragonal crystalline electric field (CEF) Hamiltonian, a systematic analysis of our macroscopic data was obtained. Our fits allowed us to extract a simple but very distinct CEF scheme, as compared to the AFM counterparts. As in the previously studied ferromagnet CeAgSb2, a pure |±1 /2 > ground state is realized, hinting at a general trend within the ferromagnetic members. More generally, we propose a scenario for the understanding of the magnetism in this family of compounds based on the subtle changes of dimensionality in the crystal structure.

Separation of enilconazole enantiomers in capillary electrophoresis with cyclodextrin-type chiral selectors and investigation of structure of selector-selectand complexes by using nuclear magnetic resonance spectroscopy.

PubMed

Gogolashvili, Ann; Tatunashvili, Elene; Chankvetadze, Lali; Sohajda, Tamas; Szeman, Julianna; Salgado, Antonio; Chankvetadze, Bezhan

2017-08-01

In the present study, the enantiomer migration order (EMO) of enilconazole in the presence of various cyclodextrins (CDs) was investigated by capillary electrophoresis (CE). Opposite EMO of enilconazole were observed when β-CD or the sulfated heptakis(2-O-methyl-3,6-di-O-sulfo)-β-CD (HMDS-β-CD) was used as the chiral selectors. Nuclear magnetic resonance (NMR) spectroscopy was used to study the mechanism of chiral recognition between enilconazole enantiomers and those two cyclodextrins. On the basis of rotating frame nuclear Overhauser (ROESY) experiments, the structure of an inclusion complex between enilconazole and β-CD was derived, in which (+)-enilconazole seemed to form a tighter complex than the (-)-enantiomer. This correlates well with the migration order of enilconazole enantiomers observed in CE. No evidence of complexation between enilconazole and HMDS-β-CD could be gathered due to lack of intermolecular nuclear Overhauser effect (NOE). Most likely the interaction between enilconazole and HMDS-β-CD leads to formation of a shallow external complex that is sufficient for separation of enantiomers in CE but cannot be evidenced based on ROESY experiment. Thus, in this particular case CE documents the presence of intermolecular interactions which are at least very difficult to be evidenced by other instrumental techniques. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CD147 reinforces [Ca2+]i oscillations and promotes oncogenic progression in hepatocellular carcinoma.

PubMed

Tang, Juan; Guo, Yun-Shan; Yu, Xiao-Ling; Huang, Wan; Zheng, Ming; Zhou, Ying-Hui; Nan, Gang; Wang, Jian-Chao; Yang, Hai-Jiao; Yu, Jing-Min; Jiang, Jian-Li; Chen, Zhi-Nan

2015-10-27

Oscillations in intracellular Ca2+ concentrations ([Ca2+]i) mediate various cellular function. Although it is known that [Ca2+]i oscillations are susceptible to dysregulation in tumors, the tumor-specific regulators of [Ca2+]i oscillations are poorly characterized. We discovered that CD147 promotes hepatocellular carcinoma (HCC) metastasis and proliferation by enhancing the amplitude and frequency of [Ca2+]i oscillations in HCC cells. CD147 activates two distinct signaling pathways to regulate [Ca2+]i oscillations. By activating FAK-Src-IP3R1 signaling pathway, CD147 promotes Ca2+ release from endoplasmic reticulum (ER) and enhances the amplitude of [Ca2+]i oscillations. Furthermore, CD147 accelerates ER Ca2+refilling and enhances the frequency of [Ca2+]i oscillations through activating CaMKP-PAK1-PP2A-PLB-SERCA signaling pathway. Besides, CD147-promoted ER Ca2+ release and refilling are tightly regulated by changing [Ca2+]i. CD147 may activate IP3R1 channel under low [Ca2+]i conditions and CD147 may activate SERCA pump under high [Ca2+]i conditions. CD147 deletion suppresses HCC tumorigenesis and increases the survival rate of liver-specific CD147 knockout mice by regulating [Ca2+]i oscillations in vivo. Together, these results reveal that CD147 functions as a critical regulator of ER-dependent [Ca2+]i oscillations to promote oncogenic progression in HCC.

CD147 reinforces [Ca2+]i oscillations and promotes oncogenic progression in hepatocellular carcinoma

PubMed Central

Zheng, Ming; Zhou, Ying-Hui; Nan, Gang; Wang, Jian-Chao; Yang, Hai-Jiao; Yu, Jing-Min; Jiang, Jian-Li; Chen, Zhi-Nan

2015-01-01

Oscillations in intracellular Ca2+ concentrations ([Ca2+]i) mediate various cellular function. Although it is known that [Ca2+]i oscillations are susceptible to dysregulation in tumors, the tumor-specific regulators of [Ca2+]i oscillations are poorly characterized. We discovered that CD147 promotes hepatocellular carcinoma (HCC) metastasis and proliferation by enhancing the amplitude and frequency of [Ca2+]i oscillations in HCC cells. CD147 activates two distinct signaling pathways to regulate [Ca2+]i oscillations. By activating FAK-Src-IP3R1 signaling pathway, CD147 promotes Ca2+ release from endoplasmic reticulum (ER) and enhances the amplitude of [Ca2+]i oscillations. Furthermore, CD147 accelerates ER Ca2+ refilling and enhances the frequency of [Ca2+]i oscillations through activating CaMKP-PAK1-PP2A-PLB-SERCA signaling pathway. Besides, CD147-promoted ER Ca2+ release and refilling are tightly regulated by changing [Ca2+]i. CD147 may activate IP3R1 channel under low [Ca2+]i conditions and CD147 may activate SERCA pump under high [Ca2+]i conditions. CD147 deletion suppresses HCC tumorigenesis and increases the survival rate of liver-specific CD147 knockout mice by regulating [Ca2+]i oscillations in vivo. Together, these results reveal that CD147 functions as a critical regulator of ER-dependent [Ca2+]i oscillations to promote oncogenic progression in HCC. PMID:26498680

High color rendering index WLED based on YAG:Ce phosphor and CdS/ZnS core/shell quantum dots

NASA Astrophysics Data System (ADS)

Shen, Changyu; Li, Ke

2009-08-01

White LED combining of blue chip and YAG:Ce phosphor suffers from a red spectral deficiency, resulting in a relatively low value of color rendering index (CRI). In our study, for an effort to improve color rendering properties of YAG:Ce phosphor-based white LEDs, highly luminescent red-orange emitting CdS/ZnS QDs were blended with YAG:Ce phosphors. Core/shell CdS/ZnS quantum dots with the emission wavelength of 618nm, was synthesized by thermal deposition using cadmium oxide and selenium as precursors in a hot lauric acid and hexadecylamine trioctylphosphine oxide hybrid. YAG:Ce phosphor was synthesized by high-temperature solid state reaction at 900-1200°C in a slightly reducing atmosphere for 4 hours. Blends of phosphors and QDs exhibited the prominent spectral evolution with an increasing content of QDs. A hybrid white LED, which combines a blue LED with the blend of YAG phosphor and QDs with a weight ratio of 1.5:1,was demonstrated with an improved CRI value of 86.

Evolution of ground-state wave function in CeCoIn5 upon Cd or Sn doping

NASA Astrophysics Data System (ADS)

Chen, K.; Strigari, F.; Sundermann, M.; Hu, Z.; Fisk, Z.; Bauer, E. D.; Rosa, P. F. S.; Sarrao, J. L.; Thompson, J. D.; Herrero-Martin, J.; Pellegrin, E.; Betto, D.; Kummer, K.; Tanaka, A.; Wirth, S.; Severing, A.

2018-01-01

We present linear polarization-dependent soft-x-ray absorption spectroscopy data at the Ce M4 ,5 edges of Cd- and Sn-doped CeCoIn5. The 4 f ground-state wave functions have been determined for their superconducting, antiferromagnetic, and paramagnetic ground states. The absence of changes in the wave functions in CeCo (In1-xCdx) 5 suggests that the 4 f -conduction-electron (c f ) hybridization is not affected by global Cd doping, thus supporting the interpretation of magnetic droplets nucleating long-range magnetic order. This is contrasted by changes in the wave function due to Sn substitution. Increasing Sn in CeCo (In1-ySny) 5 compresses the 4 f orbitals into the tetragonal plane of these materials, suggesting enhanced c f hybridization with the in-plane In(1) atoms and a homogeneous altering of the electronic structure. As these experiments show, the 4 f wave functions are a very sensitive probe of small changes in the hybridization of 4 f and conduction electrons, even conveying information about direction dependencies.

Distribution of fission products palladium, silver, cerium and cesium in the un-corroded areas of the locally corroded SiC layer of a neutron irradiated TRISO fuel particle

DOE PAGES

Wen, Haiming; van Rooyen, Isabella J.

2017-04-14

Here, detailed electron microscopy studies were performed to investigate the distribution and composition of fission products in the SiC layer of a tristructural isotropic coated particle exhibiting localized corrosion. Previous studies on this particle indicated that pure carbon areas in the SiC layer, resulting from localized corrosion of SiC by Pd, provide pathways for Ag, Cd and Cs migration. This study reveals the presence of Ag- and/or Cd-containing precipitates in un-corroded SiC areas. Ag/Cd may exist by themselves or coexist with Pd. Ag/Cd mainly transport along SiC grain boundaries. An Ag-Pd-Cd precipitate was identified at a stacking fault inside amore » SiC grain, suggesting that intragranular transport of Ag/Cd is possible. Ce is present with Pd or Pd-U in some precipitates >50 nm. U and Ce frequently coexist with each other, whereas Ag/Cd usually does not coexist with U or Ce. No Cs was detected in any precipitates in the areas examined.« less

The risk of retention of the capsule endoscope in patients with known or suspected Crohn's disease.

PubMed

Cheifetz, Adam S; Kornbluth, Asher A; Legnani, Peter; Schmelkin, Ira; Brown, Alphonso; Lichtiger, Simon; Lewis, Blair S

2006-10-01

Capsule endoscopy (CE) allows visualization of the mucosa of the entire small bowel and is therefore a potentially important tool in the evaluation of patients with known or suspected Crohn's disease (CD). However, small bowel strictures, which are not uncommon in Crohn's, are considered to be a contraindication to CE for fear of capsule retention. Our goal was to determine the risk of capsule retention in patients with suspected or known CD. We retrospectively reviewed the records of 983 CE cases performed at three private gastroenterology practices between December 2000 and December 2003, and selected those with suspected or proven Crohn's. A total of 102 cases were identified in which CE was used in patients with suspected (N = 64) or known (N = 38) CD. Only one of 64 patients (1.6%) with suspected CD had a retained capsule. However, in five of 38 (13%) patients with known Crohn's, the capsule was retained proximal to a stricture. Of the five cases of retained capsules, three strictures were previously unknown. In four cases, the obstructing lesions were resected without complications, leading to complete resolution of the patient's underlying symptoms. One patient chose not to undergo surgery and has remained without an episode of small bowel obstruction for over 38 months. Capsule retention occurred in 13% (95% CI 5.6%-28%) of patients with known CD, but only in 1.6% (95% CI 0.2%-10%) with suspected Crohn's. A retained capsule may indicate unsuspected strictures in Crohn's that may require an unexpected, but therapeutic, surgical intervention. Patients and physicians should be aware of these potential risks when using CE in CD.

International Conference (4th) on Nanostructured Materials Held in Stockholm, Sweden on 14-19 June 1998. Book of Abstracts

DTIC Science & Technology

1998-06-19

Coatings P2-67 Kuruvilla, B.A.; Nanda, J.; Sarma, D.D.; India Optical Properties ofPbS- CdS Coated Semiconductor Nanoparticles P2-68 Misra, S.; India...including phosphors, pigments and magnetic materials. In this study, the synthesis of ZnS, CdS and Ce2S3 nanoparticles by mechanochemical reaction has...formation of separated nanoparticles ; ZnS, CdS and Ce2S3 nanoparticles of ~7 nm, ɠ nm and -20 nm, respectively, were obtained. The average size of CdS

Luminescence properties of Ca2 Ga2 SiO7 :RE phosphors for UV white-light-emitting diodes.

PubMed

Jiao, Mengmeng; Lv, Wenzhen; Lü, Wei; Zhao, Qi; Shao, Baiqi; You, Hongpeng

2015-03-16

A series of Eu(2+) -, Ce(3+) -, and Tb(3+) -doped Ca2 Ga2 SiO7 phosphors is synthesized by using a high-temperature solid-state reaction. The powder X-ray diffraction and structure refinement data indicate that our prepared phosphors are single phased and the phosphor crystalizes in a tetrahedral system with the ${P\\bar 42m}$ (113) space group. The Eu(2+) - and Ce(3+) -doped phosphors both have broad excitation bands, which match well with the UV light-emitting diodes chips. Under irradiation of λ=350 nm, Ca2 Ga2 SiO7 :Eu(2+) and Ca2 Ga2 SiO7 :Ce(3+) , Li(+) have green and blue emissions, respectively. Luminescence of Ca2 Ga2 SiO7 :Tb(3+) , Li(+) phosphor varies with the different Tb(3+) contents. The thermal stability and energy-migration mechanism of Ca2 Ga2 SiO7 :Eu(2+) are also studied. The investigation results indicate that the prepared Ca2 Ga2 SiO7 :Eu(2+) and Ca2 Ga2 SiO7 :Ce(3+) , Li(+) samples show potential as green and blue phosphors, respectively, for UV-excited white-light-emitting diodes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ca2 Al2 SiO7 :Ce3+ phosphors for mechanoluminescence dosimetry.

PubMed

Tiwari, Geetanjali; Brahme, Nameeta; Sharma, Ravi; Bisen, D P; Sao, Sanjay Kumar; Sahu, Ishwar Prasad

2016-12-01

A series of Ce 3+ ion single-doped Ca 2 Al 2 SiO 7 phosphors was synthesized by a combustion-assisted method at an initiating temperature of 600 °C. The samples were annealed at 1100 °C for 3 h and their X-ray diffraction patterns confirmed a tetragonal structure. The phase structure, particle size, surface morphology and elemental analysis were analyzed using X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy techniques. Thermoluminescence (TL) intensity increased with increase in ultraviolet (UV) light exposure time up to 15 min. With further increase in the UV irradiation time the TL intensity decreases. The increase in TL intensity indicates that trap concentration increased with UV exposure time. A broad peak at 121 °C suggested the existence of a trapping level. The peak of mechanoluminescence (ML) intensity versus time curve increased linearly with increasing impact velocity of the moving piston. Mechanoluminescence intensity increased with increase in UV irradiation time up to 15 min. Under UV-irradiation excitation, the TL and ML emission spectra of Ca 2 Al 2 SiO 7 :Ce 3+ phosphor showed the characteristic emission of Ce 3+ peaking at 400 nm (UV-violet) and originating from the Ce 3+ transitions of 5d-4f ( 2 F 5/2 and 2 F 7/2 ). The photoluminescence (PL) emission spectra for Ca 2 Al 2 SiO 7 :Ce 3+ were similar to the ML/TL emission spectra. The mechanism of ML excitation and the suitability of the Ca 2 Al 2 SiO 7 :Ce 3+ phosphor for radiation dosimetry are discussed. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

The effects of ultra-thin cerium fluoride film as the anode buffer layer on the electrical characteristics of organic light emitting diodes

NASA Astrophysics Data System (ADS)

Lu, Hsin-Wei; Tsai, Cheng-Che; Hong, Cheng-Shong; Kao, Po-Ching; Juang, Yung-Der; Chu, Sheng-Yuan

2016-11-01

In this study, the efficiency of organic light-emitting diodes (OLEDs) was enhanced by depositing a CeF3film as an ultra-thin buffer layer between the indium tin oxide (ITO) electrode and α-naphthylphenylbiphenyldiamine (NPB) hole transport layer, with the structure configuration ITO/CeF3 (0.5, 1, and 1.5 nm)/α-naphthylphenylbiphenyl diamine (NPB) (40 nm)/tris(8-hydroxyquinoline) aluminum (Alq3) (60 nm)/lithium fluoride (LiF) (1 nm)/Al (150 nm). The enhancement mechanism was systematically investigated via several approaches. The X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy results revealed the formation of the UV-ozone treated CeF3 film. The work function increased from 4.8 eV (standard ITO electrode) to 5.22 eV (0.5-nm-thick UV-ozone treated CeF3 film deposited on the ITO electrode). The surface roughness of the UV-ozone treated CeF3 film was smoother than that of the standard ITO electrode. Further, the UV-ozone treated CeF3 film increased both the surface energy and polarity, as determined from contact angle measurements. In addition, admittance spectroscopy measurements showed an increased capacitance and conductance of the OLEDs. Accordingly, the turn-on voltage decreased from 4.2 V to 3.6 V at 1 mA/cm2, the luminance increased from 7588 cd/m2 to 24760 cd/m2, and the current efficiency increased from 3.2 cd/A to 3.8 cd/A when the 0.5-nm-thick UV-ozone treated CeF3 film was inserted into the OLEDs.

Incorporation of cerium oxide into hydroxyapatite coating regulates osteogenic activity of mesenchymal stem cell and macrophage polarization.

PubMed

Li, Kai; Shen, Qingyi; Xie, Youtao; You, Mingyu; Huang, Liping; Zheng, Xuebin

2017-02-01

Biomedical coatings for orthopedic implants should facilitate osseointegration and mitigate implant-induced inflammatory reactions. Cerium oxide (CeO 2 ) ceramics possess anti-oxidative properties and can be used to decrease mediators of inflammation, which makes them attractive for biomedical applications. In our work, two kinds of CeO 2 incorporated hydroxyapatite coatings (HA-10Ce and HA-30Ce) were prepared via plasma spraying technique and the effects of CeO 2 addition on the responses of bone mesenchymal stem cells (BMSCs) and RAW264.7 macrophages were investigated. An increase in CeO 2 content in the HA coatings resulted in better osteogenic behaviors of BMSCs in terms of cell proliferation, alkaline phosphatase (ALP) activity and mineralized nodule formation. RT-PCR and western blot analysis suggested that the incorporation of CeO 2 may promote the osteogenic differentiation of BMSCs through the Smad-dependent BMP signaling pathway, which activated Runx2 expression and subsequently enhanced the expression of ALP and OCN. The expression profiles of macrophages cultured on the CeO 2 modified coating revealed a tendency toward a M2 phenotype, because of an upregulation of M2 surface markers (CD163 and CD206), anti-inflammatory cytokines (TNF-α and IL-6) and osteoblastogenesis-related genes (BMP2 and TGF-β1) as well as a downregulation of M1 surface markers (CCR7 and CD11c), proinflammatory cytokines (IL-10 and IL-1ra) and reactive oxygen species production. The results suggested the regulation of BMSCs behaviors and macrophage-mediated responses at the coating's surface were associated with CeO 2 incorporation. The incorporation of CeO 2 in HA coatings can be a valuable strategy to promote osteogenic responses and reduce inflammatory reactions.

Capillary electrophoresis/mass spectrometry determination of inorganic ions using an ion spray-sheath flow interface.

PubMed

Huggins, T G; Henion, J D

1993-01-01

The determination of inorganic cations and anions by capillary electrophoresis/mass spectrometry (CE/MS) is reported using an ion spray-sheath flow interface coupling. A twelve-component synthetic mixture of cations which included the positive ions of K, Ba, Ca, Mn, Cd, Co, Pb, Cr, Ni, Zn, Ag, and Cu was loaded into the capillary column at levels ranging from 30 to 300 pg, separated by CE, and detected by indirect UV and in the full-scan (m/z 35-450) positive ion CE/MS mode using an aqueous buffer containing 30 mM creatinine and 8 mM alpha-hydroxyisobutyric acid, pH 4.8. Creatinine forms adducts with the cations which are observed in the gas phase and requires rather high (120 electron volts) declustering energy to dissociate. This produces a reduction in charge state to form the free, singly charged, inorganic cations which are observed in the mass spectra. CE/MS analysis of an aqueous acidic extract of used aircraft engine oil revealed high levels of lead as well as lower levels of chromium and nickel. CE-indirect UV analysis of a synthetic mixture containing 300 pg each of 11 inorganic ions, which included the anions of Br, Cl, NO2, NO3, S2O3, N3, SCN, SO4, SeO4, oxalate, and MoO4, is shown. The running buffer which affected this separation contained 5 mM ammonium dichromate, 10 mM ammonium acetate, and 20 mM diethylenetriamine at pH 9.3. Although indirect UV detection revealed good separation of these anions, CE/MS analysis of this mixture was complicated by interfering ion current signals from the cluster ions formed by the interaction between the additives and the analytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Multidimensional Analysis of Curved Root Canal Preparation Using Continuous or Reciprocating Nickel-titanium Instruments

PubMed Central

Mamede-Neto, Iussif; Borges, Álvaro Henrique; Alencar, Ana Helena Gonçalves; Duarte, Marco Antonio Hungaro; Sousa Neto, Manoel Damião; Estrela, Carlos

2018-01-01

Objective: To evaluate transportation (T) and centering ability (CA) of root canal preparations using continuous or reciprocating nickel-titanium endodontic files. Materials and Methods: Ninety-six mesiobuccal root canals of mandibular first and second molars were randomly divided into 6 groups (n=16) according to the rotary file used: 1. ProTaper Next; 2. ProTaper Gold; 3. Mtwo; 4. BioRaCe; 5. WaveOne Gold; 6. Reciproc. Root canals were prepared according to manufacturer’s instructions. Cone beam computed tomography scans were obtained before and after root canal preparation. Measurements were made at six different reference points: 2, 3 and 4 mm from the apex and 2, 3 and 4 mm below furcation in different directions. Results: The greatest Mesiodistal (MD) Transportation (T) was found for Reciproc files (p<0.05), and the greatest buccolingual (BL) T, for Reciproc, ProTaper Gold and ProTaper Next files (p<0.05). The greatest Mesiodistal (MD) Centering Ability (CA) was found for BioRaCe files (p<0.05), and the greatest Buccolingual (BL) CA, for BioRaCe and Mtwo files (p<0.05). Conclusion: All systems produced root canal transportation. No file system achieved perfect CA of root preparation. Reciproc files had the greatest MD T and BL T. BioRaCe files had the greatest MD CA, whereas BL CA was similar for BioRaCe and Mtwo files. PMID:29456772

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.

Mechanistic insights from DGT and soil solution measurements on the uptake of Ni and Cd by radish.

PubMed

Luo, Jun; Cheng, Hao; Ren, Jinghua; Davison, William; Zhang, Hao

2014-07-01

This work tests the previously proposed hypothesis that plant uptake of metals is determined dominantly by diffusional controlled or plant limiting uptake mechanisms at, respectively, low and high metal concentrations. Radish (Raphanus sativus) was grown in 13 soils spiked with Ni (10 and 100 mg kg(-1)) and Cd (0.5 and 4 mg kg(-1)) for 4 weeks to investigate the mechanisms affecting plant uptake. Soil solution concentrations, Css, of Ni and Cd were measured, along with the DGT interfacial concentration, CDGT, and the derived effective concentration in soil solution, CE. Free ion activities, aNi(2+) and aCd(2+), were obtained using WHAM 6. Although there was a poor relationship between Ni in radish roots and either Css or aNi(2+) in unamended soils, the distribution of data could be rationalized in terms of the extent of release of Ni from the soil solid phase, as identified by DGT and soil solution measurements. By contrast Ni in radish was linearly related to CE, demonstrating diffusion limited uptake. For soils amended with high concentrations of Ni, linear relationships were obtained for Ni in radish plotted against, Css, aNi(2+), and CE, consistent with the plant controlling uptake. For Ni the hypothesis concerning dominant diffusional and plant limiting uptake mechanisms was demonstrated. Poor relationships between Cd in radish and Css, aCd(2+), and CE, irrespective of amendment by Cd, showed the importance of factors other than diffusional supply, such as rhizosphere and inhibitory processes, and that fulfilment of this hypothesis is plant and metal specific.

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.

Photocatalytic degradation effect of malachite green and catalytic hydrogenation by UV-illuminated CeO2/CdO multilayered nanoplatelet arrays: Investigation of antifungal and antimicrobial activities.

PubMed

Maria Magdalane, C; Kaviyarasu, K; Judith Vijaya, J; Jayakumar, C; Maaza, M; Jeyaraj, B

2017-04-01

CeO 2 /CdO multi-layered nanoplatelet arrays have been synthesized by sol-gel method at two different temperatures using Citrus limonum fruit extract and the effect of particle size on the photocatalytic performance is studied. The particle size and phases was analysed by X-ray diffraction pattern (XRD) which brought out the formation of cubic phase in the synthesized samples. Field Emission Scanning electron microscopy (FESEM) revealed the surface morphology and made up of cumulative form of platelet shaped arrays with an average size of 10nm. The elemental composition and the purity of the nanomaterials were confirmed by Energy Dispersive X-ray spectroscopy (EDX). CeO 2 /CdO multilayered binary metal oxide nanoplatelet arrays were formed which was further explored with Fourier transform infrared spectroscopy (FTIR), it reveals that the nanocomposites contain CeO and CdO bonds. Determination of the direct and indirect bandgap energy of the nanoplatelet arrays was carried out by UV-Vis-DRS studies. In MG degradation, both the hole (h + ) and hydroxyl radical (OH) played a major role than the superoxide radical (O 2 - ). Possible photo degradation mechanisms are proposed and discussed in this article. CeO 2 /CdO multi-layered nanoplatelet arrays showed antibacterial activity and among the tested ones, it showed better growth inhibition towards P. aeruginosa MTCC73. Thus, this greener synthetic procedure was a highly effective method due to low-cost, highly effective UV light responsive material for environmental safety. Copyright © 2017. Published by Elsevier B.V.

A potential single-phased emission-tunable silicate phosphor Ca3Si2O7:Ce3+,Eu2+ excited by ultraviolet light for white light emitting diodes

NASA Astrophysics Data System (ADS)

Lv, Wenzhen; Guo, Ning; Jia, Yongchao; Zhao, Qi; You, Hongpeng

2013-03-01

Single-phased Ca3Si2O7:Ce3+,Eu2+ phosphor has been successfully prepared by the high temperature solid-state method. The phosphor shows efficient excitation bands from 200 to 400 nm and adjustable emission bands through the energy transfer from the Ce3+ to Eu2+ ions. The color hues can change from blue towards white ultimately to orange by adjusting the percentage content of doping ions. The investigation reveals that an electric dipole-dipole reaction mechanism should be responsible for the energy transfer from the Ce3+ to Eu2+ ions. The critical distance was obtained from the spectral overlap in terms of Dexter's theory. The developed phosphor Ca3Si2O7:Ce3+,Eu2+ exhibits two bands at 440 and 625 nm, respectively, which reveling that it has a great potentiality to be an UV-convertible phosphor for white-light emitting diodes with low color temperature.

Calcium Deficiency Triggers Phloem Remobilization of Cadmium in a Hyperaccumulating Species1

PubMed Central

Tian, Shengke; Xie, Ruohan; Wang, Haixin; Hu, Yan; Ge, Jun; Liao, Xingcheng; Gao, Xiaoyu; Brown, Patrick; Lin, Xianyong; Lu, Lingli

2016-01-01

Understanding cadmium (Cd) accumulation in plants is critical for the development of plant-based strategies for soil remediation and crop safety. Sedum alfredii is a nonbrassica plant species known to hyperaccumulate Cd. The characteristics of Cd uptake, distribution, and retranslocation affected by the Ca status were investigated at cellular levels in S. alfredii. Low Ca supply significantly increased Cd contents in shoots of S. alfredii, particularly in the young leaves. Micro x-ray fluorescence images confirmed that sequestration of Cd was greatly enhanced in the young leaves under Ca deficiency stress, with a significant amount of Cd localized in mesophyll cells, compared to the young leaves supplied with high Ca levels. Cd influx into protoplasts isolated from young leaves was significantly inhibited by the addition of Ca channel inhibitors, but not by pre-exposure to Ca deficiency. In stems, the Cd signal in vascular systems under low Ca levels was 10-fold higher than in those treated with higher Ca levels. A detailed investigation of vascular bundles revealed that an extremely high Cd signal induced by low Ca supply occurred in the phloem tissues, but not in the xylem tissues. Transfer of Cd pretreated plants to nutrient solutions at different Ca levels confirmed that a much higher amount of Cd was reallocated to the new growth tissues under low Ca stress compared to plants supplied with sufficient Ca. These results suggest that Ca deficiency triggered a highly efficient phloem remobilization of Cd in S. alfredii and subsequently enhanced Cd accumulation in its young leaves. PMID:27789737

Selection of metal oxides in the preparation of rice husk ash (RHA)/CaO sorbent for simultaneous SO2 and NO removal.

PubMed

Dahlan, Irvan; Lee, Keat Teong; Kamaruddin, Azlina Harun; Mohamed, Abdul Rahman

2009-07-30

In this work, the removal of SO(2) and NO from simulated flue gas from combustion process was investigated in a fixed-bed reactor using rice husk ash (RHA)/CaO-based sorbent. Various metal precursors were used in order to select the best metal impregnated over RHA/CaO sorbents. The results showed that RHA/CaO sorbents impregnated with CeO(2) had the highest sorption capacity among other impregnated metal oxides for the simultaneous removal of SO(2) and NO. Infrared spectroscopic results indicated the formation of both sulfate (SO(4)(2-)) and nitrate (NO(3)(-)) species due to the catalytic role played by CeO(2). Apart from that, the catalytic activity of the RHA/CaO/CeO(2) sorbent was found to be closely related to its physical properties (specific surface area, total pore volume and average pore diameter).

Does plant architectural complexity increase with increasing habitat complexity? A test with a pioneer shrub in the Brazilian Cerrado.

PubMed

Silveira, F A O; Oliveira, E G

2013-05-01

Understanding variation in plant traits in heterogeneous habitats is important to predict responses to changing environments, but trait-environment associations are poorly known along ecological gradients. We tested the hypothesis that plant architectural complexity increases with habitat complexity along a soil fertility gradient in a Cerrado (Neotropical savanna) area in southeastern Brazil. Plant architecture and productivity (estimated as the total number of healthy infructescences) of Miconia albicans (SW.) Triana were examined in three types of vegetation which together form a natural gradient of increasing soil fertility, tree density and canopy cover: grasslands (campo sujo, CS), shrublands (cerrado sensu strico, CE) and woodlands (cerradão, CD). As expected, plants growing at the CS were shorter and had a lower branching pattern, whereas plants at the CD were the tallest. Unexpectedly, however, CD plants did not show higher architectural complexity compared to CE plants. Higher architectural similarity between CE and CD plants compared to similarity between CS and CE plants suggests reduced expression of functional architectural traits under shade. Plants growing at the CE produced more quaternary shoots, leading to a larger number of infructescences. This higher plant productivity in CE indicates that trait variation in ecological gradients is more complex than previously thought. Nematode-induced galls accounted for fruit destruction in 76.5% infructescences across physiognomies, but percentage of attack was poorly related to architectural variables. Our data suggest shade-induced limitation in M. albicans architecture, and point to complex phenotypic variation in heterogeneous habitats in Neotropical savannas.

Synthesis and thermoluminescence characteristics of γ-irradiated K3Ca2(SO4)3F:Eu or Ce fluoride

NASA Astrophysics Data System (ADS)

Poddar, Anuradha; Gedam, S. C.; Dhoble, S. J.

2015-05-01

New halophosphor K3Ca2(SO4)3F activated by Eu and Ce has been synthesized by a co-precipitation method and characterized according to its thermoluminescence. The formation of traps in rare earth doped K3Ca2(SO4)3F and the effects of γ-radiation dose on the glow curve are discussed. The glow curve of K3Ca2(SO4)3F:Ce shows a prominent single peak at 150°C, whereas K3Ca2(SO4)3F:Eu and K3Ca2(SO4)3F:Ce,Eu at 142°C and 192°C, respectively. A single glow peak indicates that there is only one set of trap being activated within the particular temperature range. The presented phosphors are also studied because of its fading, reusability and trapping parameters. There was just 2% fading during a period of 10 days, indicating no serious fading problem. Trapping parameters such as order of kinetics (b), activation energy (E) and frequency factor (S) were calculated by using Chen's half-width method. The observations presented in this paper are good for lamp phosphors as well as solid-state dosimeter.

Thermoluminescence response of K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3} nanophosphor Co-doped with Eu and Ce for gamma ray dosimetry

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

Patil, B. J.; Bhadane, Mahesh S.; Dahiwale, S. S.

2015-06-24

K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3} nanophosphors co-doped with Eu and Ce were synthesized by the chemical co-precipitation method. These samples were further annealed at 700 °C structural reformation. The structural and morphological characteristics were studied using XRD and TEM techniques. The particle size calculated from XRD spectra was around 35 nm. The as synthesized sample shows cubic structure annealed at 700 °C. The as synthesized and annealed sample of K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}: EuCe were irradiated with Co{sup 60} gamma rays for the doses from 2Gy to 1kGy. The TL characteristic sample of co-doped were studied for the dosimetric applicationmore » by gamma radiation. The TL spectrum of annealed sample has single peaked at 160 °C. The Eu doped sample has a high TL sensitivity than Ce doped sample. But after co-doping with Eu and Ce, TL intensity observed to be decreased. The decrees in TL peak intensity of the phosphor on co-doping of Eu and Ce gives an insight into the emission mechanism of the phosphor which involves energy transfer from Eu to Ce. The TL response of all the samples were found to be linear for the dose from 2 Gy to 1 KGy. Therefore, K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}: EuCe nanophosphor can be used for the measurement of high dose of gamma radiation.« less

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.

Capsule endoscopy: Current practice and future directions

PubMed Central

Hale, Melissa F; Sidhu, Reena; McAlindon, Mark E

2014-01-01

Capsule endoscopy (CE) has transformed investigation of the small bowel providing a non-invasive, well tolerated means of accurately visualising the distal duodenum, jejunum and ileum. Since the introduction of small bowel CE thirteen years ago a high volume of literature on indications, diagnostic yields and safety profile has been presented. Inclusion in national and international guidelines has placed small bowel capsule endoscopy at the forefront of investigation into suspected diseases of the small bowel. Most commonly, small bowel CE is used in patients with suspected bleeding or to identify evidence of active Crohn’s disease (CD) (in patients with or without a prior history of CD). Typically, CE is undertaken after upper and lower gastrointestinal flexible endoscopy has failed to identify a diagnosis. Small bowel radiology or a patency capsule test should be considered prior to CE in those at high risk of strictures (such as patients known to have CD or presenting with obstructive symptoms) to reduce the risk of capsule retention. CE also has a role in patients with coeliac disease, suspected small bowel tumours and other small bowel disorders. Since the advent of small bowel CE, dedicated oesophageal and colon capsule endoscopes have expanded the fields of application to include the investigation of upper and lower gastrointestinal disorders. Oesophageal CE may be used to diagnose oesophagitis, Barrett’s oesophagus and varices but reliability in identifying gastroduodenal pathology is unknown and it does not have biopsy capability. Colon CE provides an alternative to conventional colonoscopy for symptomatic patients, while a possible role in colorectal cancer screening is a fascinating prospect. Current research is already addressing the possibility of controlling capsule movement and developing capsules which allow tissue sampling and the administration of therapy. PMID:24976712

CLC-mediated anion transport in plant cells

PubMed Central

De Angeli, Alexis; Monachello, Dario; Ephritikhine, Geneviève; Frachisse, Jean-Marie; Thomine, Sébastien; Gambale, Franco; Barbier-Brygoo, Hélène

2008-01-01

Plants need nitrate for growth and store the major part of it in the central vacuole of cells from root and shoot tissues. Based on few studies on the two model plants Arabidopsis thaliana and rice, members of the large ChLoride Channel (CLC) family have been proposed to encode anion channels/transporters involved in nitrate homeostasis. Proteins from the Arabidopsis CLC family (AtClC, comprising seven members) are present in various membrane compartments including the vacuolar membrane (AtClCa), Golgi vesicles (AtClCd and AtClCf) or chloroplast membranes (AtClCe). Through a combination of electrophysiological and genetic approaches, AtClCa was shown to function as a 2NO3−/1H+ exchanger that is able to accumulate specifically nitrate into the vacuole, in agreement with the main phenotypic trait of knockout mutant plants that accumulate 50 per cent less nitrate than their wild-type counterparts. The set-up of a functional complementation assay relying on transient expression of AtClCa cDNA in the mutant background opens the way for studies on structure–function relationships of the AtClCa nitrate transporter. Such studies will reveal whether important structural determinants identified in bacterial or mammalian CLCs are also crucial for AtClCa transport activity and regulation. PMID:18957376

Nonstoichiometry in inorganic fluorides: I. Nonstoichiometry in MF m - RF n ( m < n ≤ 4) systems

NASA Astrophysics Data System (ADS)

Sobolev, B. P.

2012-05-01

The manifestation of gross nonstoichiometry in MF m - RF n systems ( m < n ≤ 4) has been studied. Fluorides of 34 elements, in the systems of which phases of practical interest are formed, are chosen. To search for new phases of complex composition, a program for studying the phase diagrams of the condensed state (˜200 systems) has been carried out at the Institute of Crystallography, Russian Academy of Sciences. The main products of high-temperature interactions of the fluorides of elements with different valences ( m ≠ n) are grossly nonstoichiometric phases of two structural types: fluorite (CaF2) and tysonite (LaF3). Systems of fluorides of 27 elements ( M 1+ = Na, K; M 2+ = Ca, Sr, Ba, Cd, Pb; R 3+ = Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu; R 4+ = Zr, Hf, Th, U) are selected; nonstoichiometric M 1 - x R x F m(1 - x) + nx phases, which are of greatest practical interest, are formed in these systems. The gross nonstoichiometry in inorganic fluorides is most pronounced in 80 MF2 - RF3 systems ( M = Ca, Sr, Ba, Cd, Pb; R are rare earth elements). The problems related to the growth of single crystals of nonstoichiometric phases and basic fields of their application as new fluoride multicomponent materials, the properties of which are controlled by the defect structure, are considered.

Synthesis and characterization of cadmium-calcium hydroxyapatite solid solutions

NASA Astrophysics Data System (ADS)

Zhao, Xin; Zhu, Yi-nian; Dai, Liu-qin

2014-06-01

A series of cadmium-calcium hydroxyapatite solid solutions was prepared by an aqueous precipitation method. By various means, the characterizations confirmed the formation of continuous solid solutions over all ranges of Cd/(Cd+Ca) atomic ratio. In the results, both lattice parameters a and c display slight deviations from Vegard's rule when the Cd/(Cd+Ca) atomic ratio is greater than 0.6. The particles change from smaller acicular to larger hexagonal columnar crystals as the Cd/(Cd+Ca) atomic ratio increases from 0-0.60 to 0.60-1.00. The area of the phosphate peak for symmetric P-O stretching decreases with the increase in Cd/(Cd+Ca) atomic ratio, and the peak disappears when the Cd/(Cd+Ca) atomic ratio is greater than 0.6; the two phosphate peaks of P-O stretching gradually merge together for the Cd/(Cd+Ca) atomic ratio near 0.60. These variations can be explained by a slight tendency of larger Cd ions to occupy M(2) sites and smaller Ca ions to prefer M(1) sites in the structure.

Universal heat conduction in Ce 1-xYb xCoIn 5: Evidence for robust nodal d-wave superconducting gap

DOE PAGES

Xu, Y.; Petrovic, C.; Dong, J. K.; ...

2016-02-01

In the heavy-fermion superconductor Ce 1-xYb xCoIn 5, Yb doping was reported to cause a possible change from nodal d-wave superconductivity to a fully gapped d-wave molecular superfluid of composite pairs near x ≈ 0.07 (nominal value x nom = 0.2). Here we present systematic thermal conductivity measurements on Ce 1-xYb xCoIn 5 (x = 0.013, 0.084, and 0.163) single crystals. The observed finite residual linear term κ 0/T is insensitive to Yb doping, verifying the universal heat conduction of the nodal d-wave superconducting gap in Ce 1-xYb xCoIn 5. Similar universal heat conduction is also observed in the CeCo(Inmore » 1–yCd y) 5 system. Furthermore, these results reveal a robust nodal d-wave gap in CeCoIn 5 upon Yb or Cd doping.« less

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

Sakai, H.; Ronning, F.; Hattori, T.

Here, we have used nuclear quadrupole resonance (NQR) to probe microscopically the response of a prototypical quantum critical metal CeCoIn 5 to substitutions of small amounts of Cd for In. Approximately half of the Cd substituents induce local Ce moments in their close proximity, as observed by site-dependent longitudinal nuclear spin relaxation rates 1/T 1. In order to reaffirm that localized f moments are induced around the Cd substituents, we find a Gaussian spin-echo decay rate 1/T 2G of transverse nuclear spin relaxation. Furthermore,more » $${T}_{1}T/{T}_{2\\text{G}}^{2}$$ for the NQR subpeak is found to be proportional to temperatures, again indicating local moments fluctuations around the Cd substituents, while that for the NQR main peak shows a T 0.7-dependence. The latter temperature dependence is close to 0.75 in pure CeCoIn 5 and indicates that the bulk electronic state is located close to a two dimensional quantum critical instability.« less

Calcium Signaling Is Involved in Cadmium-Induced Neuronal Apoptosis via Induction of Reactive Oxygen Species and Activation of MAPK/mTOR Network

PubMed Central

Luo, Yan; Chen, Zi; Liu, Lei; Zhou, Hongyu; Chen, Wenxing; Shen, Tao; Han, Xiuzhen; Chen, Long; Huang, Shile

2011-01-01

Cadmium (Cd), a toxic environmental contaminant, induces oxidative stress, leading to neurodegenerative disorders. Recently we have demonstrated that Cd induces neuronal apoptosis in part by activation of the mitogen-activated protein kineses (MAPK) and mammalian target of rapamycin (mTOR) pathways. However, the underlying mechanism remains elusive. Here we show that Cd elevated intracellular calcium ion ([Ca2+]i) level in PC12, SH-SY5Y cells and primary murine neurons. BAPTA/AM, an intracellular Ca2+ chelator, abolished Cd-induced [Ca2+]i elevation, and blocked Cd activation of MAKPs including extracellular signal-regulated kinase 1/2 (Erk1/2), c-Jun N-terminal kinase (JNK) and p38, and mTOR-mediated signaling pathways, as well as cell death. Pretreatment with the extracellular Ca2+ chelator EGTA also prevented Cd-induced [Ca2+]i elevation, MAPK/mTOR activation, as well as cell death, suggesting that Cd-induced extracellular Ca2+ influx plays a critical role in contributing to neuronal apoptosis. In addition, calmodulin (CaM) antagonist trifluoperazine (TFP) or silencing CaM attenuated the effects of Cd on MAPK/mTOR activation and cell death. Furthermore, Cd-induced [Ca2+]i elevation or CaM activation resulted in induction of reactive oxygen species (ROS). Pretreatment with BAPTA/AM, EGTA or TFP attenuated Cd-induced ROS and cleavage of caspase-3 in the neuronal cells. Our findings indicate that Cd elevates [Ca2+]i, which induces ROS and activates MAPK and mTOR pathways, leading to neuronal apoptosis. The results suggest that regulation of Cd-disrupted [Ca2+]i homeostasis may be a new strategy for prevention of Cd-induced neurodegenerative diseases. PMID:21544200

Chiral discrimination of sibutramine enantiomers by capillary electrophoresis and proton nuclear magnetic resonance spectroscopy.

PubMed

Lee, Yong-Jae; Choi, Seungho; Lee, Jinhoo; Nguyen, NgocVan Thi; Lee, Kyungran; Kang, Jong Seong; Mar, Woongchon; Kim, Kyeong Ho

2012-03-01

Capillary electrophoresis (CE) and proton nuclear magnetic resonance spectroscopy ((1)H-NMR) have been used to discriminate the enantiomers of sibutramine using cyclodextrin derivatives. Possible correlation between CE and (1)H-NMR was examined. Good correlation between the (1)H-NMR shift non-equivalence data for sibutramine and the degree of enantioseparation in CE was observed. In CE study, a method of enantiomeric separation and quantitation of sibutramine was developed using enantiomeric standards. The method was based on the use of 50 mM of phosphate buffer of pH 3.0 with 10 mM of methyl-beta-cyclodextrin (M-β-CD). 0.05% of LOD, 0.2% of LOQ for S-sibutramine enantiomer was achieved, and the method was validated and applied to the quantitative determination of sibutramine enantiomers in commercial drugs. On a 600 MHz (1)H-NMR analysis, enantiomer signal separation of sibutramine was obtained by fast diastereomeric interaction with a chiral selector M-β-CD. For chiral separation and quantification, N-methyl proton peaks (at 2.18 ppm) were selected because of its being singlet and simple for understanding of diastereomeric interaction. Effects of temperature and concentration of chiral selector on enantiomer signal separation were investigated. The optimum condition was 0.5 mg/mL of sibutramine and 10 mg/mL of M-β-CD at 10°C. Distinguishment of 0.5% of S-sibutramine in R-sibutramine was found to be possible by (1)H-NMR with M-β-CD as chiral selector. Host-guest interaction between sibutramine and M-β-CD was confirmed by (1)H-NMR studies and CE studies. A Structure of the inclusion complex was proposed considering (1)H-NMR and 2D ROESY studies.

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.

Alleviation of cadmium toxicity in Brassica juncea L. (Czern. & Coss.) by calcium application involves various physiological and biochemical strategies.

PubMed

Ahmad, Parvaiz; Sarwat, Maryam; Bhat, Nazir Ahmad; Wani, Mohd Rafiq; Kazi, Alvina Gul; Tran, Lam-Son Phan

2015-01-01

Calcium (Ca) plays important role in plant development and response to various environmental stresses. However, its involvement in mitigation of heavy metal stress in plants remains elusive. In this study, we examined the effect of Ca (50 mM) in controlling cadmium (Cd) uptake in mustard (Brassica juncea L.) plants exposed to toxic levels of Cd (200 mg L(-1) and 300 mg L(-1)). The Cd treatment showed substantial decrease in plant height, root length, dry weight, pigments and protein content. Application of Ca improved the growth and biomass yield of the Cd-stressed mustard seedlings. More importantly, the oil content of mustard seeds of Cd-stressed plants was also enhanced with Ca treatment. Proline was significantly increased in mustard plants under Cd stress, and exogenously sprayed Ca was found to have a positive impact on proline content in Cd-stressed plants. Different concentrations of Cd increased lipid peroxidation but the application of Ca minimized it to appreciable level in Cd-treated plants. Excessive Cd treatment enhanced the activities of antioxidant enzymes superoxide dismutase, ascorbate peroxidase and glutathione reductase, which were further enhanced by the addition of Ca. Additionally, Cd stress caused reduced uptake of essential elements and increased Cd accumulation in roots and shoots. However, application of Ca enhanced the concentration of essential elements and decreased Cd accumulation in Cd-stressed plants. Our results indicated that application of Ca enables mustard plant to withstand the deleterious effect of Cd, resulting in improved growth and seed quality of mustard plants.

Structural and optical characterizations of Ca2Al2SiO7:Ce3+, Mn2+ nanoparticles produced via a hybrid route

NASA Astrophysics Data System (ADS)

Teixeira, V. C.; Montes, P. J. R.; Valerio, M. E. G.

2014-07-01

Pure, Ce3+ doped and Ce3+ and Mn2+ co-doped Ca2Al2SiO7 ceramic powders were prepared by two different methodologies which are the proteic sol-gel process and a new hybrid route combining the proteic sol-gel with solid state reaction processes. The second one is an eco-friendly method because it uses natural raw materials in replacement of the metal alkoxides used in the traditional sol-gel routes. X-ray diffraction showed that Ca2Al2SiO7 crystalline phase was obtained for both preparations. Differential thermal analysis indicated that the exothermic event around 850 °C, for sample produced by proteic sol-gel method, and around 927 °C, for ceramics prepared by hybrid synthesis, can be associated to crystallization of Ca2Al2SiO7. Transmission electron microscope indicates that regular and spherical nanoparticles were obtained with average sizes of about 12 nm. The Scherrer's method was used to determine the average crystallite sizes and it was shown that nanometric crystallites were obtained of about 74 nm for samples produced via hybrid route. For all the single phase samples, the crystallite sizes are about the same and that agrees with TEM results. Diffuse optical reflectance measurements were used to estimate the Ca2Al2SiO7 optical band gap and the obtained value is about 6 eV, photoluminescence (PL) spectra presented typical emissions of Ce3+ and Mn2+ ions. Upon excitation at 352 nm the emission spectra showed a broad band centered at 415 nm due to the Ce3+ 4f1 → 5d1 typical transition. This emission is resonant with Mn2+ excitation and it transfers energy to Mn ions generating a second broad emission band centered at 620 nm due to the Mn2+. The PL results were used to obtain, as a fist approach, the Ce3+ energy levels diagram and, using the Tanabe-Sugano diagrams, the transitions due to the Mn2+ were calculated. X-ray excited optical luminescence measurements showed the same emission spectra as the PL emission spectra. Luminescence lifetime decay constants were measured for Ce and Mn co-doped and for Ce doped samples and the results indicate Ca2Al2SiO7:Ce3+, Mn2+ showed quite fast responses with main time constants below 30 ns.

Baseline element concentrations in soils and plants, Wattenmeer National Park, North and East Frisian Islands, Federal Republic of Germany

USGS Publications Warehouse

Severson, R.C.; Gough, L.P.; van den Boom, G.

1992-01-01

Baseline element concentrations are given for dune grass (Ammophilia arenaria), willow (Salix repens), moss (Hylocomium splendens) and associated surface soils. Baseline and variability data for pH, ash, Al, As, Ba, C, Ca, Cd, Ce, Co, Cr, Cu, Fe, Hg, K, La, Li, Mg, Mn, Na, Nb, Nd, Ni, P, Pb, S, Sc, Se, Sr, Th, Ti, V, Y, Yb, and Zn are reported; however, not all variables are reported for all media because, in some media, certain elements were below the analytical detection limit. Spatial variation in element concentration between five Frisian Islands are given for each of the sample media. In general, only a few elements in each media showed statistically significant differences between the islands sampled. The measured concentrations in all sample media exhibited ranges that cannot be attributed to anthropogenic additions of trace elements, with the possible exception of Hg and Pb in surface soils.Baseline element concentrations are given for dune grass (Ammophilia arenaria), willow (Salix repens), moss (Hylocomium splendens) and associated surface soils. Baseline and variability data for pH, ash, Al, As, Ba, C, Ca, Cd, Ce, Co, Cr, Cu, Fe, Hg, K, La, Li, Mg, Mn, Na, Nb, Nd, Ni, P, Pb, S, Sc, Se, Sr, Th, Ti, V, Y, Yb, and Zn are reported; however, not all variables are reported for all media because, in some media, certain elements were below the analytical detection limit. Spatial variation in element concentration between five Frisian Islands are given for each of the sample media. In general, only a few elements in each media showed statistically significant differences between the islands sampled. The measured concentrations in all sample media exhibited ranges that cannot be attributed to anthropogenic additions of trace elements, with the possible exception of Hg and Pb in surface soils.

Targeted delivery of CD44s-siRNA by ScFv overcomes de novo resistance to cetuximab in triple negative breast cancer.

PubMed

Fu, Wenyan; Sun, Hefen; Zhao, Yang; Chen, Mengting; Yang, Lipeng; Yang, Xueli; Jin, Wei

2018-05-16

The overexpression of EGFR often occurs in TNBC, and the anti-EGFR receptor antibody cetuximab is used widely to treat metastatic cancer in the clinic. However, EGFR-targeted therapies have been developed for TNBC without clinical success. In this study, we show that impaired EGFR degradation is crucial for resistance to cetuximab, which depends on the cell surface molecule CD44. To further investigate the role of CD44 in EGFR signaling and its treatment potential, we developed a targeting fusion protein composed of an anti-EGFR scFv generated from cetuximab and truncated protamine, called Ce-tP. CD44 siRNA can be specifically delivered into EGFR-positive TNBC cells by Ce-tP. Efficient knockdown of CD44 and suppression of both EGFR and downstream signaling by the Ce-tP/siRNA complex were observed in EGFR-positive TNBC cells. More importantly, our results also showed that targeted delivery of siRNA specific for CD44 can efficiently overcome resistance to EGFR targeting in TNBC cells both in vitro and in vivo. Overall, our results establish a new principle to achieve EGFR inhibition in TNBC and limit drug resistance. Copyright © 2018 Elsevier Ltd. All rights reserved.

Influence of CeO2 addition on the preparation of foamed glass-ceramics from high-titanium blast furnace slag

NASA Astrophysics Data System (ADS)

Zhou, Hong-ling; Feng, Ke-qin; Chen, Chang-hong; Yan, Zi-di

2018-06-01

Foamed glass-ceramics doped with cerium oxide (CeO2) were successfully prepared from high-titanium blast furnace slag by one-step sintering. The influence of CeO2 addition (1.5wt%-3.5wt%) on the crystalline phases, microstructure, and properties of foamed glass-ceramics was studied. Results show that CeO2 improves the stability of the glass phase and changes the two-dimensional crystallization mechanism into three-dimensional one. XRD analysis indicates the presence of Ca(Mg, Fe)Si2O6 and Ca(Ti, Mg, Al)(Si, Al)2O6 in all sintered samples. Added with CeO2, TiCeO4 precipitates, and crystallinity increases, leading to increased thickness of pore walls and uniform pores. The comprehensive properties of foamed glass-ceramics are better than that of samples without CeO2. In particular, the sample added with a suitable amount of CeO2 (2.5wt%) exhibits bulk density that is similar to and compressive strength (14.9 MPa) that is more than twice of foamed glass-ceramics without CeO2.

Manipulation of Thermally Activated Delayed Fluorescence of Blue Exciplex Emission: Fully Utilizing Exciton Energy for Highly Efficient Organic Light Emitting Diodes with Low Roll-Off.

PubMed

Wang, Zixing; Wang, Hedan; Zhu, Jun; Wu, Peng; Shen, Bowen; Dou, Dehai; Wei, Bin

2017-06-28

The application of exciplex energy has become a unique way to achieve organic light-emitting diodes (OLEDs) with high efficiencies, low turn-on voltage, and low roll-off. Novel δ-carboline derivatives with high triplet energy (T 1 ≈ 2.92 eV) and high glass transition temperature (T g ≈ 153 °C) were employed to manipulate exciplex emissions in this paper. Deep blue (peak at 436 nm) and pure blue (peak at 468 nm) thermally activated delayed fluorescence (TADF) of exciplex OLEDs were demonstrated by utilizing them as emitters with the maximum current efficiency (CE) of 4.64 cd A -1 , power efficiency (PE) of 2.91 lm W -1 , and external quantum efficiency (EQE) of 2.36%. Highly efficient blue phosphorescent OLEDs doped with FIrpic showed a maximum CE of 55.6 cd A -1 , PE of 52.9 lm W -1 , and EQE of 24.6% respectively with very low turn on voltage at 2.7 V. The devices still remain high CE of 46.5 cd A -1 at 100 cd m -2 , 45.4 cd A -1 at 1000 cd m -2 and 42.3 cd A -1 at 5000 cd m -2 with EQE close to 20% indicating low roll-off. Manipulating blue exciplex emissions by chemical structure gives an ideal strategy to fully utilize all exciton energies for lighting of OLEDs.

CCR7(lo)PD-1(hi) CXCR5(+) CD4(+) T cells are positively correlated with levels of IL-21 in active and transitional cystic echinococcosis patients.

PubMed

Zhang, Fengbo; Pang, Nannan; Zhu, Yuejie; Zhou, Dexian; Zhao, Hui; Hu, Jinwei; Ma, Xiumin; Li, Jun; Wen, Hao; Samten, Buka; Fan, Haining; Ding, Jianbing

2015-10-26

In our study, we investigated whether circulating T follicular helper (Tfh) and the related cytokines are involved in human cystic echinococcosis (CE). A total of 64 patients with CE and 30 healthy controls were enrolled in this study. Percentages of CCR7(lo)PD-1(hi) cells within CXCR5(+) CD4(+) T cells (circulating Tfh cells) were detected by flow cytometry. Levels of IL-21 and IL-4 in peripheral blood were detected by cytometric bead array. The mRNA expression of IL-21, IL-4, Bcl-6, and Blimp-1 in peripheral blood mononuclear cells (PBMCs) were measured by real-time PCR. Levels of IgG1, IgG2, IgG3, and IgG4 in the patients' sera were measured using enzyme-linked immunosorbent assay. Percentages of circulating Tfh cells were significantly increased in the CE1, CE2, and CE3 groups (p < 0.05). The concentrations of IL-21 and IL-4 in the serum were significantly increased in CE1, CE2, and CE3 groups (p < 0.05). IL-21 was positively correlated with circulating Tfh cells in CE3 group (r = 0.779, p < 0.05). The mRNA levels of IL-21, IL-4, and Bcl-6 were increased in CE1, CE2, and CE3 groups. Levels of IgG1 and IgG4 in patients' sera were increased in CE1, CE2, and CE3 groups. Levels of IgG2 and IgG3 were increased in CE4-5 group. Additionally, after stimulation with hydatid fluid in vitro, the levels of circulating Tfh cells, IL-21 and IL-4 in PBMCs isolated from CE patients were significantly increased (p < 0.05). The levels of circulating Tfh and related cytokines were significantly increased in CE patients, suggesting that they are involved in human CE.

Enantiomeric separation of antimalarial drugs by capillary electrophoresis using neutral and negatively charged cyclodextrins.

PubMed

Németh, Krisztina; Tárkányi, Gábor; Varga, Erzsébet; Imre, Tímea; Mizsei, Réka; Iványi, Róbert; Visy, Júlia; Szemán, Julianna; Jicsinszky, László; Szente, Lajos; Simonyi, Miklós

2011-02-20

Capillary electrophoresis (CE) methods for chiral resolution of five antimalarial drugs (primaquine, tafenoquine, mefloquine, chloroquine and quinacrine) were developed by using a wide selection of neutral and anionic cyclodextrin (CD) derivatives. The use of sulfobutyl-β-CD and carboxymethyl-β-CD (CMBCD) resulted in good resolution of quinacrine and tafenoquine, respectively. New results are presented for resolutions of chloroquine and mefloquine. Application of carboxyalkyl- and sulfobutyl-CD derivatives provided improved resolution for primaquine. The impurity in primaquine sample detected by CE was identified as quinocide by MS and NMR. CMBCD provided not only the best separation of primaquine from quinocide but also the simultaneous complete resolution of both compounds. Copyright © 2010 Elsevier B.V. All rights reserved.

"Confused by Multiple Deities, Ancient Egyptians Embraced Monotheism": Analysing Historical Thinking and Inclusion in Egyptian History Textbooks

ERIC Educational Resources Information Center

Abdou, Ehaab D.

2016-01-01

Egyptian history textbooks are examined through the prism of historical thinking dimensions and skills, utilizing a critical discourse analysis. The analysis focuses on how the textbooks portray two historically significant events: the advent of Christianity (ca. 33 CE) and Islam (ca. 641 CE) to Egypt. It reveals that the historical narrative…

Testing Room-Temperature Ionic Liquid Solutions for Depot Repair of Aluminum Coatings

DTIC Science & Technology

2011-05-01

Ne 3 Na Mg IIIB IVB VB VIB VIIB ------ VIIIB ------ IB IIB Al Si P S Cl Ar 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 5 Rb Sr Y Zr Nb Mo Tc...Ru Rh Pd Ag Cd In Sn Sb Te I Xe 6 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 7 Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np...Electroplating Bath Lid Arrangement ;:::::::::::=== Thermometer Purge gas vent Anode lead Cathode lead (Extractable from the lid) Purge feed gas

Nonstoichiometry in inorganic fluorides: I. Nonstoichiometry in MF{sub m}-RF{sub n} (m < n {<=} 4) systems

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

Sobolev, B. P., E-mail: sobolevb@yandex.ru

The manifestation of gross nonstoichiometry in MF{sub m}-RF{sub n} systems (m < n {<=} 4) has been studied. Fluorides of 34 elements, in the systems of which phases of practical interest are formed, are chosen. To search for new phases of complex composition, a program for studying the phase diagrams of the condensed state ({approx}200 systems) has been carried out at the Institute of Crystallography, Russian Academy of Sciences. The main products of high-temperature interactions of the fluorides of elements with different valences (m {ne} n) are grossly nonstoichiometric phases of two structural types: fluorite (CaF{sub 2}) and tysonite (LaF{submore » 3}). Systems of fluorides of 27 elements (M{sup 1+} = Na, K; M{sup 2+} = Ca, Sr, Ba, Cd, Pb; R{sup 3+} = Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu; R{sup 4+} = Zr, Hf, Th, U) are selected; nonstoichiometric M{sub 1-x}R{sub x}F{sub m(1-x)+nx} phases, which are of greatest practical interest, are formed in these systems. The gross nonstoichiometry in inorganic fluorides is most pronounced in 80 MF{sub 2} - RF{sub 3} systems (M = Ca, Sr, Ba, Cd, Pb; R are rare earth elements). The problems related to the growth of single crystals of nonstoichiometric phases and basic fields of their application as new fluoride multicomponent materials, the properties of which are controlled by the defect structure, are considered.« less

Facile in-situ reduction: Crystal growth and magnetic studies of reduced vanadium (III/IV) silicates CaxLn1-xVSiO5 (Ln = Ce-Nd, Sm-Lu, Y)

NASA Astrophysics Data System (ADS)

Abeysinghe, Dileka; Smith, Mark D.; Morrison, Gregory; Yeon, Jeongho; zur Loye, Hans-Conrad

2018-04-01

A series of lanthanide containing mixed-valent vanadium (III/IV) silicates of the type CaxLn1-xVSiO5 (Ln = Ce-Nd, Sm-Lu, Y) was synthesized as high quality single crystals from a molten chloride eutectic flux, BaCl2/NaCl. Utilizing Ca metal as the reducing agent, an in-situ reduction of V5+ to V3+/4+ as well as of Ce4+ to Ce3+ was achieved. The structures of 14 reported isostructural compounds were determined by single crystal X-ray diffraction. They crystallize in the tilasite (CaMgAsO4F) structure type in the monoclinic space group C2/c. The extended structure contains 1D chains of VO6 octahedra that are connected to each other via SiO4 groups and (Ca/Ln)O7 polyhedra. The magnetic susceptibility and the field dependent magnetization data were measured for CaxLn1-xVSiO5 (Ln = Ce-Nd, Sm, Gd-Lu, Y), and support the existence of antiferromagnetic behavior at low temperatures.

Optical properties in the visible luminescence of SiO2:B2O3:CaO:GdF3 glass scintillators containing CeF3

NASA Astrophysics Data System (ADS)

Park, J. M.; Kim, H. J.; Karki, Sujita; Kaewkhao, J.; Damdee, B.; Kothan, S.; Kaewjaeng, S.

2017-12-01

CeF3-doped silicaborate-calcium-gadolinium glass scintillators, with the formula 10SiO2:(55-x)B2O3:10CaO:25GdF3:xCeF3, were fabricated by the melt-quenching technique. The doping concentration of the CeF3 was from 0.00 mol% to 0.20 mol%. The optical properties of the CeF3 doped glass scintillators were studied by using various radiation sources. The transition state of the CeF3-doped glass scintillators studied by using the absorption and photo-luminescence spectrum results. The X-ray, photo, proton and laser-induced luminescence spectra were also studied to understand the luminescence mechanism under various conditions. To understand the temperature dependence, the laser-induced luminescence and the decay component of the CeF3-doped glass scintillator were studied while the temperature was varied from 300 K to 10 K. The emission wavelength spectrum showed from 350 nm to 55 nm under various radiation sources. Also the CeF3-doped glass scintillator have one decay component as 34 ns at room temperature.

Magnetic resonance enterography or video capsule endoscopy – what do Crohn’s disease patients prefer?

PubMed Central

Lahat, Adi; Kopylov, Uri; Amitai, Marianne M; Neuman, Sandra; Levhar, Nina; Yablecovitch, Doron; Avidan, Benjamin; Yanai, Henit; Dotan, Iris; Chowers, Yehuda; Weiss, Batya; Ben-Horin, Shomron; Eliakim, Rami

2016-01-01

Background Despite differences in the information obtained by capsule endoscopy (CE) and magnetic resonance enterography (MRE), one of these modalities is usually needed when evaluating disease activity. There are no data on patients’ preference that would help guide the choice between these two modalities in these instances. Aim To compare patients’ tolerance and preference to MRE versus CE. Patients and methods Patients with known small bowel Crohn’s disease (CD) in clinical remission (Crohn’s disease activity index [CDAI] <150) or with mild symptoms (CDAI <220) were prospectively recruited. All patients underwent MRE followed by CE. Patients were asked to fill out a questionnaire addressing specific points regarding inconvenience during the preparation for the procedures, the procedures, and postprocedures. Side effects and procedure preference were addressed. Questionnaires were included for analysis only when more than 95% of the items were addressed. Results Fifty-six patients fulfilled inclusion criteria. Pre-exam discomfort, during-exam discomfort, nausea, vomiting, bloating, and abdominal pain were all significantly more prominent in MRE as compared to CE (P<0.0001, P<0.0001, P<0.0001, P=0.009, P=0.0002, P<0.0001, respectively). MRE was perceived as a more difficult procedure (P<0.0001). Furthermore, MRE was associated with a specific adverse event – claustrophobia. Seventy-eight percent of patients (44 patients) preferred to repeat CE as compared to 22% (P<0.0001) who preferred MRE. Conclusion CE was better tolerated by CD patients compared to MRE and was preferred by 78% of patients. The superior tolerability of CE should be considered along with the diagnostic features, and more data sought when choosing between these two modalities for CD patients for long-term follow-up. PMID:27354774

Inter-decadal changes in the intensity of the Oxygen Minimum Zone off Concepción, Chile (~ 36° S) over the last century

NASA Astrophysics Data System (ADS)

Srain, B.; Pantoja, S.; Sepúlveda, J.; Lange, C. B.; Muñoz, P.; Summons, R. E.; McKay, J.; Salamanca, M.

2015-04-01

We reconstructed oxygenation changes in the Oxygen Minimum Zone of the upwelling ecosystem off Concepción (36° S), Chile, using inorganic and organic proxies in a sediment core covering the last ca. 110 years of sedimentation in this area. Authigenic enrichments of Mo, U and Cd were observed between ca. 1935-1971 CE indicating a prolonged period of more reduced conditions in bottom waters and surface sediments. Significant positive correlations (p < 0.05; Spearman) between redox sensitive metals, algal sterols, biomarkers of anaerobic microorganisms, and archaeal glycerol dialkyl glycerol tetraether indicated a coupling among bottom water oxygen depletion, and increased primary and export production, suggesting that the period with low O2 of ca. 35 years, follows low frequency inter-decadal variation of the Pacific Decadal Oscillation, which may have resulted in O2 depletion over the entire continental shelf off Concepción. Taken together with the concurrent increase in sedimentary molecular indicators of anaerobic microbes allow us to suggest that the prokaryote community has been influenced by changes in oxygenation of the water column.

Charge-coupled Substituted Garnets (Y3-xCa0.5xM0.5x)Fe5O12 (M = Ce, Th): Structure and Stability as Crystalline Nuclear Waste Forms

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

Guo, Xiaofeng; Kukkadapu, Ravi K.; Lanzirotti, Anthony

2015-04-20

The garnet structure has been proposed as a potential crystalline nuclear waste form for accommodation of actinide elements, especially uranium (U). In this study, yttrium iron garnet (YIG) as a model garnet host was studied for the incorporation of U analogs, cerium (Ce), and thorium (Th), incorporated by a charge-coupled substitution with calci-um (Ca) for yttrium (Y) in YIG, namely 2Y3+ = Ca2+ + M4+, where M4+ = Ce4+ or Th4+. Single phase garnets Y3-xCa0.5xM0.5xFe5O12, synthesized by the citrate-nitrate combustion method, were obtained up to x = 0.7. Ce was confirmed to be tetravalent by X-ray absorption spectroscopy and X-raymore » photoelectron spectroscopy. X-ray diffraction and 57Fe-Mössbauer spectroscopy indicated that the samples are single phase, M4+ and Ca2+ cations are restricted to the c-site, the nature of M4+ has only a minor effect on the structure, and the local environments of both the tetrahedral and octahedral Fe3+ are systematically affected by the extent of substitution, especially on the tetrahedral sublattice. The charge coupled substitution has advantages in incorporating Ce/Th and in stabilizing the substituted phases, compared to a single substitution strategy. Enthalpies of formation of garnets were obtained by high temperature oxide melt solution calorimetry, and the enthalpies of substitution of Ce and Th were determined. The thermodynamic analysis demonstrates that the substituted garnets are entropically rather than energetically stabilized. This suggests that such garnets may form and persist in repositories at high temperature but might decompose near room temperature. These structural and thermodynamic findings shed light on possible incorporation of U in this garnet system.« less

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

USGS Publications Warehouse

DeLong, Kristine L.; Maupin, Christopher R.; Flannery, Jennifer A.; Quinn, Terrence M.; Shen, CC

2014-01-01

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.

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.

Effect of atomic disorder and Ce doping on superconductivity of Ca 3 Rh 4 Sn 13 : Electric transport properties under high pressure

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

Ślebarski, Andrzej; Goraus, Jerzy; Maśka, Maciej M.

2016-06-13

Here, we report the observation of a superconducting state below ~8 K coexistent with a spin-glass state caused by atomic disorder in Ce substituted Ca 3Rh 4Sn 13. Measurements of specific heat, resistivity, and magnetism reveal the existence of inhomogeneous superconductivity in samples doped with Ce with superconducting critical temperatures T c higher than those observed in the parent compound. For Ca 3Rh 4Sn 13, the negative value of the change in resistivity ρ with pressure P, dρ/dP correlates well with the calculated decrease in the density of states (DOS) at the Fermi energy with P. In conclusion, based onmore » band-structure calculations performed under pressure, we demonstrate how the change in DOS would affect T c of Ca 3Rh 4Sn 13 under negative lattice pressure in samples that are strongly defected by quenching.« less

Charge-coupled substituted garnets (Y 3–x Ca 0.5x M 0.5x )Fe₅O₁₂ (M = Ce, Th): Structure and stability as crystalline nuclear waste forms

DOE PAGES

Guo, Xiaofeng; Kukkadapu, Ravi K.; Lanzirotti, Antonio; ...

2015-04-20

The garnet structure has been proposed as a potential crystalline nuclear waste form for accommodation of actinide elements, especially uranium (U). In this study, yttrium iron garnet (YIG) as a model garnet host was studied for the incorporation of U analogs, cerium (Ce) and thorium (Th), incorporated by a charge-coupled substitution with calcium (Ca) for yttrium (Y) in YIG, namely, 2Y³⁺ = Ca²⁺ + M⁴⁺, where M⁴⁺ = Ce⁴⁺ or Th⁴⁺. Single-phase garnets Y 3–xCa 0.5xM 0.5xFe₅O₁₂ (x = 0.1–0.7) were synthesized by the citrate–nitrate combustion method. Ce was confirmed to be tetravalent by X-ray absorption spectroscopy and X-ray photoelectronmore » spectroscopy. X-ray diffraction and ⁵⁷Fe–Mössbauer spectroscopy indicated that M⁴⁺ and Ca²⁺ cations are restricted to the c site, and the local environments of both the tetrahedral and the octahedral Fe³⁺ are systematically affected by the extent of substitution. The charge-coupled substitution has advantages in incorporating Ce/Th and in stabilizing the substituted phases compared to a single substitution strategy. Enthalpies of formation of garnets were obtained by high-temperature oxide melt solution calorimetry, and the enthalpies of substitution of Ce and Th were determined. The thermodynamic analysis demonstrates that the substituted garnets are entropically rather than energetically stabilized. This suggests that such garnets may form and persist in repositories at high temperature but might decompose near room temperature.« less

Risk of capsule endoscope retention in pediatric patients: a large single-center experience and review of the literature.

PubMed

Atay, Orhan; Mahajan, Lori; Kay, Marsha; Mohr, Franziska; Kaplan, Barbara; Wyllie, Robert

2009-08-01

Capsule retention is a potential complication of capsule endoscopy (CE). The aims of our study were to determine the incidence of capsule retention in pediatric patients undergoing CE and to identify potential risk factors for capsule retention. We performed an institutional review board-approved retrospective chart review of pediatric patients undergoing CE studies at a single center. Data collected included patient age, sex, prior diagnosis of inflammatory bowel disease (IBD), CE indication, prior small bowel series results, study result, and complications. Two hundred seven CE procedures were performed in pediatric patients during the study period. Capsule retention occurred in 3 (1.4%) of the 207 studies. All 3 patients had known Crohn disease (CD). The risk of capsule retention in pediatric patients with known IBD was 5.2% (3/58). The risk of capsule retention for patients with suspected IBD and all other indications was 0%. If small bowel disease was identified on upper gastrointestinal series in patients with known CD, then the risk of capsule retention was 37.5% (3/8). Only 7 patients with known IBD had a body mass index (BMI) below the 5th percentile. Of these 7 patients, 3 (43%) had capsule retention. Red flags for potential CE retention identified in our study include known IBD (5.2% retention risk), previous small bowel follow-through demonstrating small bowel CD (37.5% retention risk), and BMI <5th percentile with known IBD (43% retention risk). Caution is advised in these pediatric patients before capsule ingestion.

Effects of cadmium, calcium, age and parity on bone mineral, density and strength in female rats

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

Hammond, B.F.

Weanling female rats were fed diets containing one of three levels of calcium and one of four levels of cadmium in the drinking water. Approximately 10 animals from each group were sacrificed after the first pregnancy and the remaining animals after the fourth pregnancy. Reproductive performance, plasma and bone Ca and P and bone density and strength were measured. After the first pregnancy, offspring of dams treated with 5 or 10 ppM Cd were smaller at birth than offspring of dams treated with 0 or 1 ppM Cd. Offspring of dams fed 5 or 10 ppM Cd or the 0.3%more » Ca diet had decreased weaning weight regardless of parity. Cadmium treatment had no effect on the plasma Ca or the Ca-P ratio. At Cd levels of 5 or 10 ppM the plasma P was increased. The 0.3% Ca diet depressed the plasma Ca and the 0.9% Ca diet elevated the plasma Ca and depressed the plasma P when compared to the 0.6% diet. Parity did not affect plasma Ca but, after four pregnancies, plasma P was decreased. Plasma Ca of mature dams was higher than that of adolescent dams but plasma P was unaffected. Bone mineral, density and strength were decreased by the 0.3% Ca diet especially when Cd levels reached 10 ppM. Increasing dietary Ca above normal increased femur Ca of dams fed 1 ppM Cd but did not increase the Ca of the femur of dams given higher levels of Cd. After the first pregnancy, femur Ca of mature dams was greater than that of adolescent dams. After the fourth pregnancy, femurs of mature dams were less strong than those of adolescent dams; however, the density was the same. Increasing dietary Ca above 0.6% lessened the detrimental effects of 5 ppM Cd ingestion on bone density. Mature dams were less affected by the 0.3% Ca 10 ppM Cd treatment than were adolescent dams. 60 refs., 3 figs., 26 tabs.« less

Cadmium is acutely toxic for murine hepatocytes: effects on intracellular free Ca(2+) homeostasis.

PubMed

Wang, S S; Chen, L; Xia, S K

2007-01-01

We studied cadmium toxicity in murine hepatocytes in vitro. Cadmium effects on intracellular free Ca(2+) concentration ([Ca(2+)](i)) were assayed, using a laser scanning confocal microscope with a fluorescent probe, Fluo-3/AM. The results showed that administration of cadmium chloride (CdCl(2), 5, 10, 25 microM) resulted in a dose-dependent decrease of hepatocyte viability and an elevated aspartate aminotransferase (AST) activity in the culture medium (p<0.05 for 25 microM CdCl(2) vs. control). Significant increases of lactate dehydrogenase (LDH) activities in 10 and 25 microM CdC1(2)-exposed groups were observed (p<0.05 and p<0.01, respectively). A greatly decreased albumin content and a more malondialdehyde (MDA) formation also occurred after CdC1(2) treatment. The Ca(2+) concentrations in the culture medium of CdCl(2)-exposed hepatocytes were significantly decreased, while [Ca(2+)](i) appeared to be significantly elevated (p<0.05 or p<0.01 vs. control). We found that in Ca(2+)-containing hydroxyethyl piperazine ethanesulfonic acid-buffered salt solution (HBSS) only, CdCl(2) elicited [Ca(2+)](i) increases, which comprised an initially slow ascent and a strong elevated phase. However, in Ca(2+)-containing HBSS with addition of 2-aminoethoxydiphenyl borane (2-APB), CdCl(2) caused a mild [Ca(2+)](i) elevation in the absence of an initial rise phase. Removal of extracellular Ca(2+) showed that CdCl(2) induced an initially slow [Ca(2+)](i) rise alone without being followed by a markedly elevated phase, but in a Ca(2+)-free HBSS with addition of 2-APB, CdCl(2) failed to elicit the [Ca(2+)](i) elevation. These results suggest that abnormal Ca(2+) homeostasis due to cadmium may be an important mechanism of the development of the toxic effect in murine hepatocytes. [Ca(2+)](i) elevation in acutely cadmium-exposed hepatocytes is closely related to the extracellular Ca(2+) entry and an excessive release of Ca(2+) from intracellular stores.

Redox-Sensitive Cerium Oxide Nanoparticles Protect Human Keratinocytes from Oxidative Stress Induced by Glutathione Depletion.

PubMed

Singh, Ragini; Karakoti, Ajay S; Self, William; Seal, Sudipta; Singh, Sanjay

2016-11-22

Cerium oxide nanoparticles (CeNPs) have gathered much attention in the biomedical field due to its unique antioxidant property. It can protect cells and tissues from oxidative stress induced damage due to its autoregenerative redox cycle. Our study explores the antioxidant and antigenotoxic behavior of PEGylated CeNPs toward oxidative insult produced by buthionine sulfoximine (BSO) in human keratinocytes (HaCaT cells). BSO inhibits the γ-glutamylcysteinesynthetase (γ-GCS) enzyme and thus acts as a glutathione (GSH) depleting agent to modulate the cellular redox potential. GSH is a natural ROS scavenger present in the mammalian cells, and its depletion causes generation of reactive oxygen species (ROS). In this study, we challenged HaCaT cells (keratinocytes) with BSO to alter the redox potential within the cell and monitored toxicity, ROS generation, and nuclear fragmentation. We also followed changes in expressions of related proteins and genes. We found that PEGylated CeNPs can protect HaCaT cells from BSO-induced oxidative damage. BSO-exposed cells, preincubated with PEGylated CeNPs, showed better cell survival and significant decrease in the intracellular levels of ROS. We also observed decrease in lactate dehydrogenase (LDH) release and nuclear fragmentation in CeNP-treated cells that were challenged with BSO as compared to treatment with BSO alone. Exposure of HaCaT cells with BSO leads to altered expression of antioxidant genes and proteins, i.e., thioredoxin reductase (TrxR) and peroxiredoxin 6 (Prx6) whereas, in our study, pretreatment of PEGylated CeNPs reduces the need for induction of genes that produce enzymes involved in the defense against oxidative stress. Since, growing evidence argued the involvement of ROS in mediating death of mammalian cells in several ailments, our finding reinforces the use of PEGylated CeNPs as a potent pharmacological agent under the lower cellular GSH/GSSG ratios for the treatment of diseases mediated by free radicals.

In Vitro and In Vivo Prostate Cancer Metastasis and Chemoresistance Can Be Modulated by Expression of either CD44 or CD147

PubMed Central

Hao, Jingli; Madigan, Michele C.; Khatri, Aparajita; Power, Carl A.; Hung, Tzong-Tyng; Beretov, Julia; Chang, Lei; Xiao, Weiwei; Cozzi, Paul J.; Graham, Peter H.; Kearsley, John H.; Li, Yong

2012-01-01

CD44 and CD147 are associated with cancer metastasis and progression. Our purpose in the study was to investigate the effects of down-regulation of CD44 or CD147 on the metastatic ability of prostate cancer (CaP) cells, their docetaxel (DTX) responsiveness and potential mechanisms involved in vitro and in vivo. CD44 and CD147 were knocked down (KD) in PC-3M-luc CaP cells using short hairpin RNA (shRNA). Expression of CD44, CD147, MRP2 (multi-drug resistance protein-2) and MCT4 (monocarboxylate tranporter-4) was evaluated using immunofluorescence and Western blotting. The DTX dose-response and proliferation was measured by MTT and colony assays, respectively. The invasive potential was assessed using a matrigel chamber assay. Signal transduction proteins in PI3K/Akt and MAPK/Erk pathways were assessed by Western blotting. An in vivo subcutaneous (s.c.) xenograft model was established to assess CaP tumorigenecity, lymph node metastases and DTX response. Our results indicated that KD of CD44 or CD147 decreased MCT4 and MRP2 expression, reduced CaP proliferation and invasive potential and enhanced DTX sensitivity; and KD of CD44 or CD147 down-regulated p-Akt and p-Erk, the main signal modulators associated with cell growth and survival. In vivo, CD44 or CD147-KD PC-3M-luc xenografts displayed suppressed tumor growth with increased DTX responsiveness compared to control xenografts. Both CD44 and CD147 enhance metastatic capacity and chemoresistance of CaP cells, potentially mediated by activation of the PI3K and MAPK pathways. Selective targeting of CD44/CD147 alone or combined with DTX may limit CaP metastasis and increase chemosensitivity, with promise for future CaP treatment. PMID:22870202

Liming effects on cadmium stabilization in upland soil affected by gold mining activity.

PubMed

Hong, Chang Oh; Lee, Do Kyoung; Chung, Doug Young; Kim, Pil Joo

2007-05-01

To reduce cadmium (Cd) uptake of plants cultivated in heavy metal-contaminated soil, the best liming material was selected in the incubation test. The effect of the selected material was evaluated in the field. In the incubation experimentation, CaCO(3), Ca(OH)(2), CaSO(4).2H(2)O, and oyster shell meal were mixed with soil at rates corresponding to 0, 400, 800, 1600, 3200 mg Ca kg(-1). The limed soil was moistened to 70% of field moisture capacity, and incubated at 25 degrees C for 4 weeks. Ca(OH)(2) was found to be more efficient on reducing soil NH(4)OAc extractable Cd concentration, due to pH increase induced net negative charge. The selected Ca(OH)(2) was applied at rates 0, 2, 4, 8 Mg ha(-1) and then cultivated radish (Raphanus sativa L.) in the field. NH(4)OAc extractable Cd concentration of soil and plant Cd concentration decreased significantly with increasing Ca(OH)(2) rate, since alkaline-liming material markedly increased net negative charge of soil induced by pH increase, and decreased bioavailable Cd fractions (exchangeable + acidic and reducible Cd fraction) during radish cultivation. Cadmium uptake of radish could be reduced by about 50% by amending with about 5 Mg ha(-1) Ca(OH)(2) without adverse effect on radish yield and growth. The increase of net negative charge of soil by Ca(OH)(2) application may suppress Cd uptake and the competition between Ca(2+) and Cd(2+) may additionally affect the suppression of Cd uptake.

New mathematic model for predicting chiral separation using molecular docking: mechanism of chiral recognition of triadimenol analogues.

PubMed

Zhang, Guoqing; Sun, Qingyan; Hou, Ying; Hong, Zhanying; Zhang, Jun; Zhao, Liang; Zhang, Hai; Chai, Yifeng

2009-07-01

The purpose of this paper was to study the enantioseparation mechanism of triadimenol compounds by carboxymethylated (CM)-beta-CD mediated CE. All the enantiomers were separated under the same experimental conditions to study the chiral recognition mechanism using a 30 mM sodium dihydrogen phosphate buffer at pH 2.2 adjusted by phosphoric acid. The inclusion courses between CM-beta-CD and enantiomers were investigated by the means of molecular docking technique. It was found that there were at least three points (one hydrophobic bond and two hydrogen bonds) involved in the interaction of each enantiomer with the chiral selectors. A new mathematic model has been built up based on the results of molecular mechanics calculations, which could analyze the relationship between the resolution of enantioseparation and the interaction energy in the docking area. Comparing the results of the separation by CE, the established mathematic model demonstrated good capability to predict chiral separation of triadimenol enantiomers using CM-beta-CD mediated CE.

High efficiency yellow organic light-emitting diodes with optimized barrier layers

NASA Astrophysics Data System (ADS)

Mu, Ye; Zhang, Shiming; Yue, Shouzhen; Wu, Qingyang; Zhao, Yi

2015-12-01

High efficiency Iridium (III) bis (4-phenylthieno [3,2-c] pyridinato-N,C2‧) acetylacetonate (PO-01) based yellow organic light-emitting devices are fabricated by employing multiple emission layers. The efficiency of the device using 4,4‧,4″-tris(N-carbazolyl) triphenylamine (TCTA) as potential barrier layer (PBL) outperforms those devices based on other PBLs and detailed analysis is carried out to reveal the mechanisms. A forward-viewing current efficiency (CE) of 65.21 cd/A, which corresponds to a maximum total CE of 110.85 cd/A is achieved at 335.8 cd/m2 in the optimized device without any outcoupling enhancement structures.

Divalent metal (Ca, Cd, Mn, Zn) uptake and interactions in the aquatic insect Hydropsyche sparna.

PubMed

Poteat, Monica D; Díaz-Jaramillo, Mauricio; Buchwalter, David B

2012-05-01

Despite their ecological importance and prevalent use as ecological indicators, the trace element physiology of aquatic insects remains poorly studied. Understanding divalent metal transport processes at the water-insect interface is important because these metals may be essential (e.g. Ca), essential and potentially toxic (e.g. Zn) or non-essential and toxic (e.g. Cd). We measured accumulation kinetics of Zn and Cd across dissolved concentrations ranging 4 orders of magnitude and examined interactions with Ca and Mn in the caddisfly Hydropsyche sparna. Here, we provide evidence for at least two transport systems for both Zn and Cd, the first of which operates at concentrations below 0.8 μmol l(-1) (and is fully saturable for Zn). We observed no signs of saturation of a second lower affinity transport system at concentrations up to 8.9 μmol l(-1) Cd and 15.3 μmol l(-1) Zn. In competition studies at 0.6 μmol l(-1) Zn and Cd, the presence of Cd slowed Zn accumulation by 35% while Cd was unaffected by Zn. At extreme concentrations (listed above), Cd accumulation was unaffected by the presence of Zn whereas Zn accumulation rates were reduced by 58%. Increasing Ca from 31.1 μmol l(-1) to 1.35 mmol l(-1) resulted in only modest decreases in Cd and Zn uptake. Mn decreased adsorption of Cd and Zn to the integument but not internalization. The L-type Ca(2+) channel blockers verapamil and nifedipine and the plasma membrane Ca(2+)-ATPase inhibitor carboxyeosin had no influence on Ca, Cd or Zn accumulation rates, while Ruthenium Red, a Ca(2+)-ATPase inhibitor, significantly decreased the accumulation of all three in a concentration-dependent manner.

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

Chu, Yaoqing; School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai 201418; Zhang, Qinghong

A new silicate garnet phosphor, Lu{sub 2−x}CaMg{sub 2}Si{sub 2.9}Ti{sub 0.1}O{sub 12}:xCe was synthesized by a high temperature solid-state reaction under reductive atmosphere. X-ray diffraction (XRD) showed that the powder was pure garnet phase. The emission and excitation spectrum indicated that the Lu{sub 2−x}CaMg{sub 2}Si{sub 2.9}Ti{sub 0.1}O{sub 12}:xCe phosphors could absorb blue light in the spectral range of 400–550 nm efficiently and exhibit bright yellow–orange emission in the range of 520–750 nm. With the increase of Ce{sup 3+} concentration, the emission band of Ce{sup 3+} showed a red shift. Interestingly, the concentration quenching occurred when the Ce{sup 3+} concentration exceeded 4more » mol%. The temperature-dependent luminescent properties of the phosphors were discussed and the Lu{sub 1.96}CaMg{sub 2}Si{sub 2.9}Ti{sub 0.1}O{sub 12}:0.04Ce phosphors showed good performances in color temperature (2430 K) and potential applications for warm white LEDs. - Graphical Abstract: This image shows that the phosphor of Lu{sub 1.96}CaMg{sub 2}Si{sub 2.9}Ti{sub 0.1}O{sub 12}:0.04Ce can generate a uniform yellow tint under natural light illumination and emit orange–red light when excited by blue light. With a fixed 467 nm emission light, warm white light can be produced by this phosphor, which indicates that the phosphor is potentially applicable in warm white light emitting diodes based on GaN chips. - Highlights: • A new silicate garnet phosphor was synthesized by solid-state method. • Secondary phases can be avoided when a small amount of Si{sup 4+} were replaced by Ti{sup 4+}. • A broad emission band of Ce{sup 3+} in the phosphors was described. • The phosphors are potentially applicable in warm white light emitting diodes.« less

Thermally stable green Ba(3)Y(PO(4))3:Ce(3+),Tb(3+) and red Ca(3)Y(AlO)(3)(BO(3))4:Eu(3+) phosphors for white-light fluorescent lamps.

PubMed

Huang, Chien-Hao; Kuo, Te-Wen; Chen, Teng-Ming

2011-01-03

A class of thermal stable of green-emitting phosphors Ba(3)Y(PO(4))(3):Ce(3+),Tb(3+) (BYP:Ce(3+),Tb(3+)) and red-emitting phosphors Ca(3)Y(AlO)(3)(BO(3))(4):Eu(3+) (CYAB:Eu(3+)) for white-light fluorescent lamps were synthesized by high temperature solid-state reaction. We observed a decay of only 3% at 150 °C for BYP:0.25Ce3+,0.25Tb3+ (3% for LaPO4:Ce(3+),Tb(3+)), and a decay of 4% for CYAB:0.5Eu(3+) (7% for Y(2)O(3):Eu(3+), 24% for Y(2)O(2)S:Eu(3+)). The emission intensity of composition-optimized Ba(3)(Y(0.5)Ce(0.25)Tb(0.25))(PO(4))(3) is 70% of that of commercial LaPO(4):Ce(3+),Tb(3+) phosphors, and the CIE chromaticity coordinates are found to be (0.323, 0.534). The emission intensity of Ca(3)(Y(0.5)Eu(0.5))(AlO)(3)(BO(3))(4) is 70% and 83% of those of Y(2)O(3):Eu(3+) and Y(2)O(2)S:Eu(3+) phosphors, respectively, and the CIE chromaticity coordinates are redder (0.652, 0.342) than those of Y(2)O(3):Eu(3+) (0.645, 0.347) and Y(2)O(2)S:Eu(3+) (0.647, 0.343). A white-light fluorescent lamp is fabricated using composition-optimized Ba(3)(Y(0.5)Ce(0.25)Tb(0.25))(PO(4))(3) and Ca(3)(Y(0.5)Eu(0.5))(AlO)(3)(BO(3))(4) phosphors and matching blue-emitting phosphors. The results indicate that the quality of the brightness and color reproduction is suitable for application in shortwave UV fluorescent lamps. The white-light fluorescent lamp displays CIE chromaticity coordinates of x = 0.33, y = 0.35, a warm white light with a correlated color temperature of 5646 K, and a color-rendering index of Ra = 70.

Alkali earth co-doping effects on luminescence and scintillation properties of Ce doped Gd3Al2Ga3O12 scintillator

NASA Astrophysics Data System (ADS)

Kamada, Kei; Nikl, Martin; Kurosawa, Shunsuke; Beitlerova, Alena; Nagura, Aya; Shoji, Yasuhiro; Pejchal, Jan; Ohashi, Yuji; Yokota, Yuui; Yoshikawa, Akira

2015-03-01

The Mg and Ca co-doped Ce:Gd3Al2Ga3O12 single crystals were prepared by micro pulling down method with a wide concentration range 0-1000 ppm of the codopants. 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 and Ca co-doping. The scintillation decays were accelerated by both Mg and Ca codopants. Comparing to Ca co-doping, the Mg co-doped samples showed much faster decay and comparatively smaller light output decrease with increasing Mg dopant concentration.

Elements and inorganic ions as source tracers in recent Greenland snow

NASA Astrophysics Data System (ADS)

Lai, Alexandra M.; Shafer, Martin M.; Dibb, Jack E.; Polashenski, Chris M.; Schauer, James J.

2017-09-01

Atmospheric transport of aerosols leads to deposition of impurities in snow, even in areas of the Arctic as remote as Greenland. Major ions (e.g. Na+, Ca2+, NH4+, K+, SO42-) are frequently used as tracers for common aerosol sources (e.g. sea spray, dust, biomass burning, anthropogenic emissions). Trace element data can supplement tracer ion data by providing additional information about sources. Although many studies have considered either trace elements or major ions, few have reported both. This study determined total and water-soluble concentrations of 31 elements (Al, As, Ca, Cd, Ce, Co, Cr, Dy, Eu, Fe, Gd, K, La, Mg, Mn, Na, Nb, Nd, Pb, Pr, S, Sb, Si, Sm, Sn, Sr, Ti, V, U, Y, Zn) in shallow snow pits at 22 sampling sites in Greenland, along a transect from Summit Station to sites in the northwest. Black carbon (BC) and inorganic ions were measured in colocated samples. Sodium, which is typically used as a tracer of sea spray, did not appear to have any non-marine sources. The rare earth elements, alkaline earth elements (Mg, Ca, Sr), and other crustal elements (Fe, Si, Ti, V) were not enriched above crustal abundances relative to Al, indicating that these elements are primarily dust sourced. Calculated ratios of non-sea salt Ca (nssCa) to estimated dust mass affirm the use of nssCa as a dust tracer, but suggest up to 50% uncertainty in that estimate in the absence of other crustal element data. Crustal enrichment factors indicated that As, Cd, Pb, non-sea-salt S, Sb, Sn, and Zn were enriched in these samples, likely by anthropogenic sources. Principal component analysis indicated more than one crustal factor, and a variety of factors related to anthropogenically enriched elements. Analysis of trace elements alongside major tracer ions does not change interpretation of ion-based source attribution for sources that are well-characterized by ions, but is valuable for assessing uncertainty in source attribution and identifying sources not represented by major ions.

Bio-based epoxy/chitin nanofiber composites cured with amine-type hardeners containing chitosan.

PubMed

Shibata, Mitsuhiro; Enjoji, Motohiro; Sakazume, Katsumi; Ifuku, Shinsuke

2016-06-25

Sorbitol polyglycidyl ether (SPE) which is a bio-based water-soluble epoxy resin was cured with chitosan (CS) and/or a commercial water-soluble polyamidoamine- or polyetheramine-type epoxy hardener (PAA or PEA). Furthermore, biocomposites of the CS-cured SPE (CS-SPE) and CS/PAA- or CS/PEA-cured SPE (SPE-CA or SPE-CE) biocomposites with chitin nanofiber (CNF) were prepared by casting and compression molding methods, respectively. The curing reaction of epoxy and amino groups of the reactants was confirmed by the FT-IR spectral analysis. SPE-CS and SPE-CA were almost transparent films, while SPE-CE was opaque. Transparency of SPE-CS/CNF and SPE-CA/CNF became a little worse with increasing CNF content. The tanδ peak temperature of SPE-CS was higher than those of SPE-PAA and SPE-PEA. SPE-CA or SPE-CE exhibited two tanδ peak temperatures related to glass transitions of the CS-rich and PAA-rich or PEA-rich moieties. The tanδ peak temperatures related to the CS-rich and PAA-rich moieties increased with increasing CNF content. A higher order of tensile strengths and moduli of the cured resins was SPE-CS≫SPE-CA>SPE-CE. The tensile strength and modulus of each sample were much improved by the addition of 3wt% CNF, while further addition of CNF caused a lowering of the strength and modulus. Copyright © 2016 Elsevier Ltd. All rights reserved.

Magnetic interactions in equi-atomic rare-earth intermetallic alloys RScGe (R = Ce, Pr, Nd and Gd) studied by time differential perturbed angular correlation spectroscopy and ab initio calculations.

PubMed

Mishra, S N

2009-03-18

Applying the time differential perturbed angular correlation (TDPAC) technique we have measured electric and magnetic hyperfine fields of the (111)Cd impurity in equi-atomic rare-earth intermetallic alloys RScGe (R = Ce, Pr and Gd) showing antiferro- and ferromagnetism with unusually high ordering temperatures. The Cd nuclei occupying the Sc site show high magnetic hyperfine fields with saturation values B(hf)(0) = 21 kG, 45 kG and 189 kG in CeScGe, PrScGe and GdScGe, respectively. By comparing the results with the hyperfine field data of Cd in rare-earth metals and estimations from the RKKY model, we find evidence for the presence of additional spin density at the probe nucleus, possibly due to spin polarization of Sc d band electrons. The principal electric field gradient component V(zz) in CeScGe, PrScGe and GdScGe has been determined to be 5.3 × 10(21) V m(-2), 5.5 × 10(21) V m(-2) and 5.6 × 10(21) V m(-2), respectively. Supplementing the experimental measurements, we have carried out ab initio calculations for pure and Cd-doped RScGe compounds with R = Ce, Pr, Nd and Gd using the full potential linearized augmented plane wave (FLAPW) method based on density functional theory (DFT). From the total energies calculated with and without spin polarization we find ferrimagnetic ground states for CeScGe and PrScGe while NdScGe and GdScGe are ferromagnetic. In addition, we find a sizable magnetic moment at the Sc site, increasing from ≈0.10 μ(B) in CeScGe to ≈0.3 μ(B) in GdScGe, confirming the spin polarization of Sc d band electrons. The calculated electric field gradient and magnetic hyperfine fields of the Cd impurity closely agree with the experimental values. We believe spin polarization of Sc 3d band electrons, strongly hybridized with spin polarized 5d band electrons of the rare-earth, enables a long range Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between RE 4f moments which in turn leads to high magnetic ordering temperatures in RScGe compounds.

Concentration of stable elements in food products

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

Montford, M.A.; Shank, K.E.; Hendricks, C.

1980-01-01

Food samples were taken from commercial markets and analyzed for stable element content. The concentrations of most stable elements (Ag, Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, K, La, Mg, Mn, Mo, Na, Rb, Sb, Sc, Se, Sr, Ta, Th, Ti, V, Zn, Zr) were determined using multiple-element neutron activation analysis, while the concentrations of other elements (Cd, Hg, Ni, Pb) were determined using atomic absorption. The relevance of the concentrations found are noted in relation to other literature values. An earlier study was extended to include the determination of the concentrationmore » of stable elements in home-grown products in the vicinity of the Oak Ridge National Laboratory. Comparisons between the commercial and local food-stuff values are discussed.« less

Ternary oxide nanostructures and methods of making same

DOEpatents

Wong, Stanislaus S [Stony Brook, NY; Park, Tae-Jin [Port Jefferson, NY

2009-09-08

A single crystalline ternary nanostructure having the formula A.sub.xB.sub.yO.sub.z, wherein x ranges from 0.25 to 24, and y ranges from 1.5 to 40, and wherein A and B are independently selected from the group consisting of Ag, Al, As, Au, B, Ba, Br, Ca, Cd, Ce, Cl, Cm, Co, Cr, Cs, Cu, Dy, Er, Eu, F, Fe, Ga, Gd, Ge, Hf, Ho, I, In, Ir, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os, P, Pb, Pd, Pr, Pt, Rb, Re, Rh, Ru, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Tc, Te, Ti, Tl, Tm, U, V, W, Y, Yb, and Zn, wherein the nanostructure is at least 95% free of defects and/or dislocations.

New insights into the crystal chemistry of agardite-(Ce): refinement of the crystal structure, hydrogen bonding, and epitaxial intergrowths with the Sb-analogue of auriacusite

NASA Astrophysics Data System (ADS)

Aksenov, Sergey M.; Chukanov, Nikita V.; Göttlicher, Jörg; Möckel, Steffen; Varlamov, Dmitriy; Van, Konstantin V.; Rastsvetaeva, Ramiza K.

2018-01-01

Agardite-(Ce) from Clara Mine, Schwarzwald, Germany, has been investigated by means of electron microprobe analysis, single-crystal X-ray analysis, XANES spectroscopy and IR spectroscopy. Hexagonal unit-cell parameters are: a = 13.598(6), c = 5.954(3) Å; V = 953.5(2) Å3; space group P63/ m. The structure has been solved and refined to final R 1 = 3.87%, w R 2 = 5.02 for 786 I > 3 σ( I). Hydrogen atoms have been localized. The crystal-chemical formula is ( Z = 2): A(1)(Ce0.82Ca0.14Sr0.04)Σ1.00 A(2)(Ca0.03Ce0.02)Σ0.05 [Cu5.75(Fe3+, Mn)0.20]Σ5.95 [ T(1)(AsO4) 2.96 T(2) (SbO4)0.04)]Σ3.00 (OH)5.96O0.04·3H2O. Hydrogen bonding in agardite-series minerals has been characterized for the first time. IR spectra of agardite-(Ce) and agardite-(Nd) from Lavrion used for comparison, as well as structural data indicate the presence of isolated H+ cations that do not form strong covalent bonds with coordinating O atoms. Agardite-(Ce) from Clara Mine forms epitaxial growths with the Sb-analogue of auriacusite. The latter mineral was characterized by EDS analyses; its typical empirical formulae are {Ca}_{0.0 6} {Ce}_{0.0 4} {Fe}^{ 3+ }{}_{ 1.0 6} {Cu}_{0. 8 9}[(SbO4)0.58(AsO4)0.38(SiO4)0.04]Σ1.00(O,OH) and {Ca}_{0.0 7 5} {Ce}_{0.0 4} {Fe}^{ 3+ }{}_{0. 9 3} {Cu}_{0. 9 7}[(SbO4)0.59(AsO4)0.35(SiO4)0.06]Σ1.00(O,OH). The formation of uniaxial growths of the Sb-analogue of auriacusite and agardite-(Ce) is caused by the close values of their c parameters (for auriacusite s.s. c = 5.9501(5) Å). Three-valence state of iron and five-valence of antimony in both minerals has been validated by means of Fe K- and Sb L 2,3-edge XANES spectroscopy.

Spectral and laser properties of Er3+/Yb3+/Ce3+ tri-doped Ca3NbGa3Si2O14 crystal at 1.55 µm

NASA Astrophysics Data System (ADS)

Gong, Guoliang; Chen, Yujin; Lin, Yanfu; Huang, Jianhua; Gong, Xinghong; Luo, Zundu; Huang, Yidong

2018-04-01

An Er3+/Yb3+/Ce3+ tri-doped Ca3NbGa3Si2O14 (CNGS) crystal was grown by the Czochralski method. Spectral properties of the crystal, including the polarized absorption and fluorescence spectra, the fluorescence decay, as well as the energy transfer efficiency from Yb3+ to Er3+ were investigated in detail. End-pumped by a 976 nm diode laser, a 1556 nm continuous-wave laser with a maximum output power of 202 mW and a slope efficiency of 11.4% was achieved in the Er,Yb,Ce:CNGS crystal. The results indicate the Er,Yb,Ce:CNGS crystal is a promising 1.55 µm laser gain medium.

Lanthanum-rich fluorbritholite-(Ce) from young alkaline volcanic rock of Eifel (Germany) and its crystal structure. Cation ordering in britholites

NASA Astrophysics Data System (ADS)

Zubkova, N. V.; Chukanov, N. V.; Pekov, I. V.; Schäfer, C.; Yapaskurt, V. O.; Pushcharovsky, D. Yu.

2015-09-01

Structure (R=0.0213) of lanthanum-rich fluorbritholite (Ce) [(Ce2.47La2.31Nd0.22Pr0.13Y0.07)5.20Ca4.20Th0.27Mn0.19Sr0.09]9.95(Si5.37P0.63)6O24.16F1.95 from sanidinite in Laacher See, Eifel, Germany was studied on a monocrystal. The structure [space group P63/m, a = 9.58949 (13), c = 7.0289 (11) Å, V = 559.770 (14)Å3] is identical to structures of members of apatite supergroup. Relationships of major cations in polyhedra M(1)O9 = (Ca0.6 REE 0.4), and in polyhedral M(2)O6F = ( REE 0.7Ca0.3). Substantial structural order M(1) and M(2) is defined, simplified structural formula: (Ca, LREE)2( LREE,Ca)3(SiO4)3F. Analysis of data on crystal chemistry of britholite was carried out. It was demonstrated that distribution of cations on M(1)and M(2)-positions is always characteristic of partial structural order. Clear tendency of LREE concentration in M(2) position was noted.

Magnetic properties of quadruple perovskite solid solutions Ca{sub 1–x}Y{sub x}Cu{sub 3}Fe{sub 4}O{sub 12} and Y{sub 1–y}Ce{sub x}Cu{sub 3}Fe{sub 4}O{sub 12}

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

Murakami, Makoto; Mori, Shigeo; Yamada, Ikuya, E-mail: i-yamada@21c.osakafu-u.ac.jp

Magnetic properties of the quadruple perovskite solid solutions Ca{sub 1–x}Y{sub x}Cu{sub 3}Fe{sub 4}O{sub 12} and Y{sub 1–y}Ce{sub y}Cu{sub 3}Fe{sub 4}O{sub 12} are investigated. Ca{sub 1–x}Y{sub x}Cu{sub 3}Fe{sub 4}O{sub 12} shows continuous increase in the ferromagnetic transition temperature as x increases. Y{sub 1–y}Ce{sub y}Cu{sub 3}Fe{sub 4}O{sub 12} exhibits a ferromagnetic-antiferromagnetic transition in the vicinity of y = 0.5. These observations demonstrate the electron doping effect on magnetic properties of charge-disproportionated ACu{sub 3}Fe{sub 4}O{sub 12} phases.

CD38 Mediates Angiotensin II–Induced Intracellular Ca2+ Release in Rat Pulmonary Arterial Smooth Muscle Cells

PubMed Central

Lee, Suengwon; Paudel, Omkar; Jiang, Yongliang; Yang, Xiao-Ru

2015-01-01

CD38 is a multifunctional enzyme that catalyzes the formation of the endogenous Ca2+-mobilizing messengers cyclic ADP-ribose (cADPR) and nicotinic acid adenosine dinucleotide phosphate (NAADP) for the activation of ryanodine receptors (RyRs) of sarcoplasmic reticulum and NAADP-sensitive Ca2+ release channels in endolysosomes, respectively. It plays important roles in systemic vascular functions, but there is little information on CD38 in pulmonary arterial smooth muscle cells (PASMCs). Earlier studies suggested a redox-sensing role of CD38 in hypoxic pulmonary vasoconstriction. This study sought to characterize its roles in angiotensin II (Ang II)–induced Ca2+ release (AICR) in PASMCs. Examination of CD38 expression in various rat arteries found high levels of CD38 mRNA and protein in pulmonary arteries. The Ang II–elicited Ca2+ response consisted of extracellular Ca2+ influx and intracellular Ca2+ release in PASMCs. AICR activated in the absence of extracellular Ca2+ was reduced by pharmacological or siRNA inhibition of CD38, by the cADPR antagonist 8-bromo-cADPR or ryanodine, and by the NAADP antagonist Ned-19 or disruption of endolysosomal Ca2+ stores with the vacuolar H+-ATPase inhibitor bafilomycin A1. Suppression of AICR by the inhibitions of cADPR- and NAADP-dependent pathways were nonadditive, indicating interdependence of RyR- and NAADP-gated Ca2+ release. Furthermore, AICR was inhibited by the protein kinase C inhibitor staurosporine, the nonspecific NADPH oxidase (NOX) inhibitors apocynin and diphenyleneiodonium, the NOX2-specific inhibitor gp91ds-tat, and the scavenger of reactive oxygen species (ROS) tempol. These results provide the first evidence that Ang II activates CD38-dependent Ca2+ release via the NOX2-ROS pathway in PASMCs. PMID:25078456

Characterization of cadmium uptake and cytotoxicity in human osteoblast-like MG-63 cells

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

Levesque, Martine; Martineau, Corine; Jumarie, Catherine

Since bone mass is maintained constant by the balance between osteoclastic bone resorption and osteoblastic bone formation, alterations in osteoblast proliferation and differentiation may disturb the equilibrium of bone remodeling. Exposure to cadmium (Cd) has been associated with the alteration of bone metabolism and the development of osteoporosis. Because little information is available about the direct effects of Cd on osteoblastic cells, we have characterized in vitro the cellular accumulation and cytotoxicity of Cd in human osteoblastic cells. Incubation of osteoblast-like MG-63 cells with increasing concentrations of Cd in serum-free culture medium reduced cell viability in a time- and concentration-dependentmore » manner, suggesting that Cd accumulates in osteoblasts. Consequently, an uptake time-course could be characterized for the cellular accumulation of {sup 109}Cd in serum-free culture medium. In order to characterize the mechanisms of Cd uptake, experiments have been conducted under well-defined metal speciation conditions in chloride and nitrate transport media. The results revealed a preferential uptake of Cd{sup 2+} species. The cellular accumulation and cytotoxicity of Cd increased in the absence of extracellular calcium (Ca), suggesting that Cd may enter the cells in part through Ca channels. However, neither the cellular accumulation nor the cytotoxicity of Cd was modified by voltage-dependent Ca channel (VDCC) modulators or potassium-induced depolarization. Moreover, exposure conditions activating or inhibiting capacitative Ca entry (CCE) failed to modify the cellular accumulation and cytotoxicity of Cd, which excludes the involvement of canonical transient receptor potential (TRPC) channels. The cellular accumulation and cytotoxicity of Cd were reduced by 2-APB, a known inhibitor of the Mg and Ca channel TRPM7 and were increased in the absence of extracellular magnesium (Mg). The inhibition of Cd uptake by Mg and Ca was not additive, suggesting that each ion inhibits the same uptake mechanism. Our results indicate that Cd uptake in human osteoblastic cells occurs, at least in part, through Ca- and Mg-inhibitable transport mechanisms, which may involve channels of the TRPM family. The effect of Cd on bone metabolism may be enhanced under low Ca and/or Mg levels.« less

Cluster Chemistry in Electron-Poor Ae-Pt-Cd Systems (Ae=Ca, Sr, Ba): (Sr,Ba)Pt2Cd4, Ca6Pt8Cd16, and Its Known Antitype Er6Pd16Sb8

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

Samal, Saroj L.; Gulo, Fakhili; Corbett, John D.

Three new ternary polar intermetallic compounds, cubic Ca6Pt8Cd16, and tetragonal (Sr, Ba)Pt2Cd4 have been discovered during explorations of the Ae–Pt–Cd systems. Cubic Ca6Pt8Cd16 (Fm-3m, Z = 4, a = 13.513(1) Å) contains a 3D array of separate Cd8 tetrahedral stars (TS) that are both face capped along the axes and diagonally bridged by Pt atoms to generate the 3D anionic network Cd8[Pt(1)]6/2[Pt(2)]4/8. The complementary cationic surface of the cell consists of a face-centered cube of Pt(3)@Ca6 octahedra. This structure is an ordered ternary variant of Sc11Ir4 (Sc6Ir8Sc16), a stuffed version of the close relative Na6Au7Cd16, and a network inverse ofmore » the recent Er6Sb8Pd16 (compare Ca6Pt8Cd16). The three groups of elements each occur in only one structural version. The new AePt2Cd4, Ae = Sr, Ba, are tetragonal (P42/mnm,Z = 2, a ≈ 8.30 Å, c ≈ 4.47 Å) and contain chains of edge-sharing Cd4 tetrahedra along c that are bridged by four-bonded Ba/Sr. LMTO-ASA and ICOHP calculation results and comparisons show that the major bonding (Hamilton) populations in Ca6Pt8Cd16 and Er6Sb8Pd16 come from polar Pt–Cd and Pd–Sb interactions, that Pt exhibits larger relativistic contributions than Pd, that characteristic size and orbital differences are most evident for Sb 5s, Pt8, and Pd16, and that some terms remain incomparable, Ca–Cd versus Er–Pd.« less

Effects of Cd{sup 2+} on cis-dimer structure of E-cadherin in living cells

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

Takeda, Hiroshi, E-mail: hirotake@sapmed.ac.jp

2014-02-21

Highlights: • The effects of Cd on the dimer of cadherin in living cells was analyzed. • Cd induced cadherin dimer formation was not detected in living cell with low Ca. • Ca mediated structural cooperativity and allostery in the native cadherin. • Ca concentration-dependent competitive displacement of Cd from cadherin is proposed. - Abstract: E-cadherin, a calcium (Ca{sup 2+})-dependent cell–cell adhesion molecule, plays a key role in the maintenance of tissue integrity. We have previously demonstrated that E-cadherin functions in vivo as a cis-dimer through chemical cross-linking reagents. Ca{sup 2+} plays an important role in the cis-dimer formation ofmore » cadherin. However, the molecular mechanisms by which Ca{sup 2+} interacts with the binding sites that regulate cis-dimer structures have not been completely elucidated. As expected for a Ca{sup 2+} antagonist, cadmium (Cd{sup 2+}) disrupts cadherin function by displacing Ca{sup 2+} from its binding sites on the cadherin molecules. We used Cd{sup 2+} as a probe for investigating the role of Ca{sup 2+} in the dynamics of the E-cadherin extracellular region that involve cis-dimer formation and adhesion. While cell–cell adhesion assembly was completely disrupted in the presence of Cd{sup 2+}, the amount of cis-dimers of E-cadherin that formed at the cell surface was not affected. In our “Cd{sup 2+}-switch” experiments, we did not find that Cd{sup 2+}-induced E-cadherin cis-dimer formation in EL cells when they were incubated in low-Ca{sup 2+} medium. In the present study, we demonstrated for the first time the effects of Cd{sup 2+} on the cis-dimer structure of E-cadherin in living cells using a chemical cross-link analysis.« less

Improving precipitation hardening behavior of Mg−Zn based alloys with Ce−Ca microalloying additions

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

Langelier, B., E-mail: langelb@mcmaster.ca

2016-10-15

The precipitation hardening behavior of newly developed Mg−Zn−Ca−Ce alloys, with modified texture and improved ductility, is studied to delineate the microstructural characteristics that lead to effective hardening upon ageing treatments. Advanced electron microscopy and atom probe techniques are used to analyze the structural characteristics in relevance to the hardening potential. It has been found that the formation of a new basal precipitate phase, which evolves from a single atomic layer GP zone, and is finely distributed in both under-aged and peak-aged microstructures, has a significant impact in the improvement of the hardening response compared with the base Mg−Zn alloys. Itmore » has also been found that the β′{sub 1} rod precipitates, commonly formed during ageing treatments of Mg−Zn alloys, have their size and distribution significantly refined in the Ca−Ce containing alloys. The role of alloy chemistry in the formation of the fine basal plate GP zones and the refinement in β′{sub 1} precipitation and their relationships to the hardening behavior are discussed. It is proposed that Ca microalloying governs the formation of the GP zones and the enhancement of hardening, particularly in the under-aged conditions, but that this is aided by a beneficial effect from Ce. - Highlights: • Ce−Ca microalloying additions improve hardening in Mg−Zn, over Ce or Ca alone. • Improved hardening is due to refined β′{sub 1} rods, and fine basal plate precipitates. • Atom probe tomography identifies Ca in both β′{sub 1} and the fine basal plates. • The fine basal plates originate as ordered monolayer GP zones with 1:1 Zn:Ca (at.%). • With ageing GP zones become more Zn-rich and transform to the fine basal plates.« less

The Effect of Risk Factors on the Levels of Chemical Elements in the Tibial Plateau of Patients with Osteoarthritis following Knee Surgery.

PubMed

Lanocha-Arendarczyk, Natalia; Kosik-Bogacka, Danuta Izabela; Prokopowicz, Adam; Kalisinska, Elzbieta; Sokolowski, Sebastian; Karaczun, Maciej; Zietek, Pawel; Podlasińska, Joanna; Pilarczyk, Bogumila; Tomza-Marciniak, Agnieszka; Baranowska-Bosiacka, Irena; Gutowska, Izabela; Safranow, Krzysztof; Chlubek, Dariusz

2015-01-01

The aim of this study was to evaluate the aforementioned chemical elements in tibial plateau samples obtained during knee arthroplasty. The gender-specific analysis of chemical element levels in the bone samples revealed that there were statistically significant differences in the concentration of Pb and Se/Pb ratio. The contents of elements in the tibial plateau in the patients with osteoarthritis (OA) can be arranged in the following descending order: F(-) > K > Zn > Fe > Sr > Pb > Mn > Se > Cd > THg. We observed statistical significant effects of environmental factors including smoking, seafood diet, and geographical distribution on the levels of the elements in tibial bone. Significant positive correlation coefficients were found for the relationships K-Cd, Zn-Sr, Zn-F(-), THg-Pb, Pb-Cd, Se-Se/Pb, Se-Se/Cd, Se/Pb-Se/Cd, Pb-Cd/Ca, Cd-Cd/Ca, and F(-)-F(-)/Ca·1000. Significant negative correlations were found for the relationships THg-Se/Pb, Pb-Se/Pb, Cd-Se/Pb, K-Se/Cd, Pb-Se/Cd, Cd-Se/Cd, THg-Se/THg, Pb-Se/THg, Se-Pb/Cd, Zn-Cd/Ca, and Se/Cd-Cd/Ca. The results reported here may provide a basis for establishing reference values for the tibial plateau in patients with OA who had undergone knee replacement surgery. The concentrations of elements in the bone with OA were determined by age, presence of implants, smoking, fish and seafood diet, and sport activity.

Cd(2+) sensitivity and permeability of a low voltage-activated Ca(2+) channel with CatSper-like selectivity filter.

PubMed

Garza-López, Edgar; Chávez, Julio César; Santana-Calvo, Carmen; López-González, Ignacio; Nishigaki, Takuya

2016-07-01

CatSper is a sperm-specific Ca(2+) channel that plays an essential role in the male fertility. However, its biophysical properties have been poorly characterized mainly due to its deficient heterologous expression. As other voltage-gated Ca(2+) channels (CaVs), CatSper possesses a conserved Ca(2+)-selective filter motif ([T/S]x[D/E]xW) in the pore region. Interestingly, CatSper conserves four aspartic acids (DDDD) as the negatively charged residues in this motif while high voltage-activated CaVs have four glutamic acids (EEEE) and low voltage-activated CaVs possess two glutamic acids and two aspartic acids (EEDD). Previous studies based on site-directed mutagenesis of L- and T-type channels showed that the number of D seems to have a negative correlation with their cadmium (Cd(2+)) sensitivity. These results suggest that CatSper (DDDD) would have low sensitivity to Cd(2+). To explore Cd(2+)-sensitivity and -permeability of CatSper, we performed two types of experiments: 1) Electrophysiological analysis of heterologously expressed human CaV3.1 channel and three pore mutants (DEDD, EDDD and DDDD), 2) Cd(2+) imaging of human spermatozoa with FluoZin-1. Electrophysiological studies showed a significant increase in Cd(2+) and manganese (Mn(2+)) currents through the CaV3.1 mutants as well as a reduction in the inhibitory effect of Cd(2+) on the Ca(2+) current. In fluorescence imaging with human sperm, we observed an increase in Cd(2+) influx potentiated by progesterone, a potent activator of CatSper. These results support our hypothesis, namely that Cd(2+)-sensitivity and -permeability are related to the absolute number of D in the Ca(2+)-selective filter independently to the type of the Cav channels. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fluvial response to the last Holocene rapid climate change in the Northwestern Mediterranean coastlands

NASA Astrophysics Data System (ADS)

Degeai, Jean-Philippe; Devillers, Benoît; Blanchemanche, Philippe; Dezileau, Laurent; Oueslati, Hamza; Tillier, Margaux; Bohbot, Hervé

2017-05-01

The variability of fluvial activity in the Northwestern Mediterranean coastal lowlands and its relationship with modes of climate change were analysed from the late 9th to the 18th centuries CE. Geochemical analyses were undertaken from a lagoonal sequence and surrounding sediments in order to track the fluvial inputs into the lagoon. An index based on the K/S and Rb/S ratios was used to evidence the main periods of fluvial activity. This index reveals that the Medieval Climate Anomaly (MCA) was a drier period characterized by a lower fluvial activity, while the Little Ice Age (LIA) was a wetter period with an increase of the river dynamics. Three periods of higher than average fluvial activity were evidenced at the end of the first millennium CE (ca. 900-950 cal yr CE), in the first half of the second millennium CE (ca. 1150-1550 cal yr CE), and during the 1600s-1700s CE (ca. 1650-1800 cal yr CE). The comparison of these fluvial periods with other records of riverine or lacustrine floods in Spain, Italy, and South of France seems to indicate a general increase in fluvial and flood patterns in the Northwestern Mediterranean in response to the climate change from the MCA to the LIA, although some episodes of flooding are not found in all records. Besides, the phases of higher than average fluvial dynamics are in good agreement with the North Atlantic cold events evidenced from records of ice-rafted debris. The evolution of fluvial activity in the Northwestern Mediterranean coastlands during the last millennium could have been driven by atmospheric and oceanic circulation patterns.

The influences of the AMO and NAO on the sedimentary infill in an Azores Archipelago lake since ca. 1350 CE

NASA Astrophysics Data System (ADS)

Hernández, Armand; Sáez, Alberto; Bao, Roberto; Raposeiro, Pedro M.; Trigo, Ricardo M.; Doolittle, Sara; Masqué, Pere; Rull, Valentí; Gonçalves, Vítor; Vázquez-Loureiro, David; Rubio-Inglés, María J.; Sánchez-López, Guiomar; Giralt, Santiago

2017-07-01

The location of the Azores Archipelago in the North Atlantic makes this group of islands an excellent setting to study the long-term behavior of large oceanic and atmospheric climate dynamic patterns, such as the Atlantic Multidecadal Oscillation (AMO) and the North Atlantic Oscillation (NAO). Here, we present the impacts of these patterns on Lake Empadadas (Azores Archipelago) from the Medieval Climate Anomaly (MCA) - Little Ice Age (LIA) transition to the present based on sedimentological, geochemical and biological characterizations of the sedimentary record. Multivariate analyses of a number of proxies including X-ray fluorescence (XRF), X-ray diffraction (XRD), total organic and inorganic carbon (TOC and TIC) and diatom life forms abundance reveal that the sedimentary infill evolution has been controlled by (i) fluctuations in the lake level and (ii) variations in organic matter accumulation. Both processes are governed by climate variability and modulated by anthropogenic activities associated with changes on the lake catchment. Changes in these two sedimentary processes have been used to infer five stages: (i) the MCA-LIA transition (ca. 1350-1450 CE) was characterized by a predominantly positive AMO phase, which led to intermediate lake levels and high organic matter concentration; (ii) the first half of the LIA (ca. 1450-1600 CE) was characterized by predominant lowstand conditions and intermediate organic matter deposition mainly related to negative AMO phases; (iii) the second half of the LIA (ca. 1600-1850 CE) was characterized by negative AMO and NAO phases, implying intermediate lake levels and high organic matter deposition; (iv) the Industrial era (ca. 1850-1980 CE) was characterized by the lowest lake level and organic matter accumulation associated with negative AMO phases; and (v) the period spanning between 1980 CE and the present reveals the highest lake levels and low organic matter deposition, being associated with very positive AMO conditions. At decadal-to-centennial scales, the influence of the AMO on Azorean climate plays a larger role than previously thought. In fact, the AMO appears to exert a stronger influence compared to the NAO, which is the main mode of climate variability at shorter time scales.

Conditional substance abuse and dependence by diagnosis of mood or anxiety disorder or schizophrenia in the U.S. population.

PubMed

Martins, Silvia S; Gorelick, David A

2011-12-01

Little is known about the association of various psychiatric disorders with the risk of developing dependence or abuse among users of various psychoactive substances (conditional dependence, CD; conditional abuse, CA). Evaluate the association of psychiatric disorders with CA only, CD only and CA+CD. Secondary analysis of data from 43,093 non-institutionalized US adults in the first wave (2001-2002) of the National Epidemiological Survey on Alcohol and Related Conditions. A structured diagnostic interview allowed classification by lifetime psychiatric diagnosis (DSM-IV criteria) and psychoactive substance use. Data were analyzed using weighted proportions, 95% CIs, and weighted logistic regression models to generate odds ratios (OR) adjusted for socio-demographic characteristics. Psychiatric disorders were associated with higher prevalence of psychoactive substance use, regardless of type of disorder or substance. CA, CD and CA+CD prevalence rates were generally higher than unconditional prevalence rates among respondents with and without psychiatric disorders. Respondents with multiple disorders (mainly mood and anxiety disorders) had higher rates of CA+CD on most, but not all, psychoactive substances (e.g., not heroin), while schizophrenia was associated only with higher rates of tranquilizer CA+CD. Psychiatric disorders had few associations with CA only and CD only on psychoactive substances. Study findings suggest that mood and anxiety disorders are associated with increased prevalence of substance use and increased transition from use to CA and CD, while schizophrenia is associated with increased transition from abstinence to use, especially for marijuana. Findings did not support the self-medication hypothesis of substance use disorders. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Conditional substance abuse and dependence by diagnosis of mood or anxiety disorder or schizophrenia in the U.S. population

PubMed Central

Martins, Silvia S.; Gorelick, David A.

2011-01-01

Background Little is known about the association of various psychiatric disorders with the risk of developing dependence or abuse among users of various psychoactive substances (conditional dependence, CD; conditional abuse, CA). Objectives Evaluate the association of psychiatric disorders with CA only, CD only and CA +CD. Method Secondary analysis of data from 43,093 non-institutionalized US adults in the first wave (2001–2002) of the National Epidemiological Survey on Alcohol and Related Conditions. A structured diagnostic interview allowed classification by lifetime psychiatric diagnosis (DSM-IV criteria) and psychoactive substance use. Data were analyzed using weighted proportions, 95% CIs, and weighted logistic regression models to generate odds ratios (OR) adjusted for socio-demographic characteristics. Results Psychiatric disorders were associated with higher prevalence of psychoactive substance use, regardless of type of disorder or substance. CA, CD and CA+ CD prevalence rates were generally higher than unconditional prevalence rates among respondents with and without psychiatric disorders. Respondents with multiple disorders (mainly mood and anxiety disorders) had higher rates of CA+CD on most, but not all, psychoactive substances (e.g., not heroin), while schizophrenia was associated only with higher rates of tranquilizer CA+ CD. Psychiatric disorders had few associations with CA only and CD only on psychoactive substances. Conclusion Study findings suggest that mood and anxiety disorders are associated with increased prevalence of substance use and increased transition from use to CA and CD, while schizophrenia is associated with increased transition from abstinence to use, especially for marijuana. Findings did not support the self-medication hypothesis of substance use disorders. PMID:21641123

Microprocessor Realization of a Linear Predictive Vocoder. Appendix C. LPCM Detail Drawings and Layouts

DTIC Science & Technology

1977-02-07

CHG12 1 Dr.%VC 8 DB ILA8 DC1II 29 FTLE: FDS TAPIRWLST Al 1/19/77 16:1~2 H.I.T. LINCOLN LAB3ORATORY 1 DB116 DB16 D11G12 1 DI)V8 DD V,"R DWl 1 DBV16 DBV...5 CD27 CA27 CDC.6 CAC6 "F23 CD25 CA25 CD%.4 CAt4 IN ,7 F2’ C!ൠ CA24 CDV3 CA.^ ELI 11 CI)22 CA23 CP,2 CA,2 1D1.. CA22 CDI CA. 1 "FH𔃼 CD39 CA38 CD17...FC17 FE22 ,26 FC19 UE24 1 ’P27 FC19 F21 1 IP 29 FA V7 EF21 1 !p33* FA10 FF12" I %P32 FG𔄀 EE1 1 IP3 FG ’i^7 EF15 1 ’P 34 FGF12 Ffl2 1 1115FG ’ 1 F12

Influence of Ca and pH on the uptake and effects of Cd in Folsomia candida exposed to simplified soil solutions.

PubMed

Ardestani, Masoud M; Ortiz, Maria Diez; van Gestel, Cornelis A M

2013-08-01

The present study sought to quantify the components of a biotic ligand model (BLM) for the effects of Cd on Folsomia candida (Collembola). Assuming that soil porewater is the main route of exposure and to exclude the effects of soil particles on metal availability, animals were exposed for 7 d to different Cd concentrations between 0.1 mM and 100 mM in simplified soil solutions at different Ca concentrations (0.2 mM, 0.8 mM, 3.2 mM, and 12.8 mM) or at different pH (5.0, 6.0, and 7.0). Higher Ca concentrations decreased the toxicity of Cd (adult survival) in test solutions, whereas toxicity was slightly lower at pH 7 and 6 than at pH 5, suggesting a mitigating effect of Ca and to a lesser extent pH on Cd toxicity to F. candida. Internal Cd concentrations in the animals increased with increasing exposure level but were significantly reduced by increasing Ca concentrations and were not significantly affected by pH. By using Langmuir isotherms, binding constants for Cd, Ca, and protons and the fraction of binding sites occupied by Cd were calculated and used to predict effects of Cd on survival. Predicted toxicity showed a good agreement with measured responses when Ca and pH were used as separate factors or combined together. The present study shows indications of protective effects of Ca but less of protons on the toxicity and uptake of Cd in F. candida on exposure to simplified soil solutions, which can be described using the principles of a biotic ligand model. Copyright © 2013 SETAC.

Comparison of EDTA- and citric acid-enhanced phytoextraction of heavy metals in artificially metal contaminated soil by Typha angustifolia.

PubMed

Muhammad, Dawood; Chen, Fei; Zhao, Jing; Zhang, Guoping; Wu, Feibo

2009-08-01

A pot experiment was conducted to study the performance of EDTA and citric acid (CA) addition in improving phytoextraction of Cd, Cu, Pb, and Cr from artificially contaminated soil by T. angustifolia. T. angustifolia showed the remarkable resistance to heavy metal toxicity with no visual toxic symptom including chlorosis and necrosis when exposed to metal stress. EDTA-addition significantly reduced plant height and biomass, compared with the control, and stunted plant growth, while 2.5 and 5 mM CA addition induced significant increases in root dry weight. EDTA, and 5 and 10 mM CA significantly increased shoot Cd, Pb, and Cr concentrations compared with the control, with EDTA being more effective. At final harvest, the highest shoot Cd, Cr, and Pb concentrations were recorded in the treatment of 5 mM EDTA addition, while maximal root Pb concentration was found at the 2.5 mM CA treatment. However, shoot Cd accumulation in the 10 mM CA treatment was 36.9% higher than that in 2.5 mM EDTA, and similar with that in 10 mM EDTA. Shoot Pb accumulation was lower in 10 mM CA than that in EDTA treatments. Further, root Cd, Cu, and Pb accumulation of CA treatments and shoot Cr accumulation in 5 or 10 mM CA treatments were markedly higher than that of control and EDTA treatments. The results also showed that EDTA dramatically increased the dissolution of Cu, Cr, Pb, and Cd in soil, while CA addition had less effect on water-soluble Cu, Cr, and Cd, and no effect on Pb levels. It is suggested that CA can be a good chelator candidate for T. angustifolia used for environmentally safe phytoextraction of Cd and Cr in soils.

Coral Cd/Ca and Mn/Ca records of ENSO variability in the Gulf of California

NASA Astrophysics Data System (ADS)

Carriquiry, J. D.; Villaescusa, J. A.

2010-06-01

We analyzed the trace element ratios Cd/Ca and Mn/Ca in three coral colonies (Porites panamensis (1967-1989), Pavona clivosa (1967-1989) and Pavona gigantea (1979-1989)) from Cabo Pulmo reef, Southern Gulf of California, Mexico, to assess the oceanographic changes caused by El Niño - Southern Oscillation (ENSO) events in the Eastern Tropical North Pacific (ETNP). Interannual variations in the coral Cd/Ca and Mn/Ca ratios showed clear evidence that incorporation of Cd and Mn in the coral skeleton was influenced by ENSO conditions, but the response for each metal was controlled by different processes. The Mn/Ca ratios were significantly higher during ENSO years (p<0.05) relative to non-ENSO years for the three species of coral. In contrast, the Cd/Ca was systematically lower during ENSO years, but the difference was significant (p<0.05) only in Pavona gigantea. A decrease in the incorporation of Cd and a marked increase in Mn indicated strongly reduced vertical mixing in the Gulf of California during the mature phase of El Niño. The oceanic warming during El Niño events produces a relaxation of upwelling and a stabilization of the thermocline, which may act as a physical barrier limiting the transport of Cd from deeper waters into the surface layer. In turn, this oceanic condition can increase the residence time of particulate-Mn in surface waters, allowing an increase in the photo-reduction of particulate-Mn and the release of available Mn into the dissolved phase. These results support the use of Mn/Ca and Cd/Ca ratios in biogenic carbonates as tracers of increases in ocean stratification and trade wind weakening and/or collapse in the ETNP during ENSO episodes.

Coral Cd/Ca and Mn/Ca records of El Niño variability in the Gulf of California

NASA Astrophysics Data System (ADS)

Carriquiry, J. D.; Villaescusa, J. A.

2010-02-01

We analyzed the trace element ratios Cd/Ca and Mn/Ca in three coral colonies (Pavona gigantea, Pavona clivosa and Porites panamensis) from Cabo Pulmo reef, Southern Gulf of California, Mexico, to assess the oceanographic changes caused by El Niño - Southern Oscillation (ENSO) events in the Eastern Tropical North Pacific (ETNP). The interannual variations in the coral Cd/Ca and Mn/Ca ratios show clear evidence that incorporation of Cd and Mn in the coral skeleton are influenced by ENSO conditions, but the response for each metal is controlled by different process. The Mn/Ca ratios were significantly higher during ENSO years (p<0.05) relative to non-ENSO years for the three species of coral. In contrast, the Cd/Ca was systematically lower during ENSO years, but it was significant (p<0.05) only in P. gigantea. The decrease in the incorporation of Cd, and the marked increase in Mn during the mature phase of El Niño indicate strongly reduced vertical mixing in the Gulf of California. The oceanic warming during El Niño events produces a relaxation of upwelling and a stabilization of the thermocline which acts as a physical barrier limiting the transport of Cd from deeper waters into the surface layer. In turn, this oceanic condition can increase the residence time of particulate-Mn in surface waters, which in turn increases the photo-reduction of particulate-Mn and the release of the available Mn into the dissolved phase. These results provide validation for using Mn/Ca and Cd/Ca in biogenic carbonates as tracers of changes in ocean stratification and trade wind weakening and/or collapse in the ETNP during ENSO episodes.

Characterization of Photochemical Processes for H2 Production by CdS Nanorod-[FeFe] Hydrogenase Complexes

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

Brown, K. A.; Wilker, M. B.; Boehm, M.

2012-03-28

We have developed complexes of CdS nanorods capped with 3-mercaptopropionic acid (MPA) and Clostridium acetobutylicum [FeFe]-hydrogenase I (CaI) that photocatalyze reduction of H{sup +} to H{sub 2} at a CaI turnover frequency of 380-900 s{sup -1} and photon conversion efficiencies of up to 20% under illumination at 405 nm. In this paper, we focus on the compositional and mechanistic aspects of CdS:CaI complexes that control the photochemical conversion of solar energy into H{sub 2}. Self-assembly of CdS with CaI was driven by electrostatics, demonstrated as the inhibition of ferredoxin-mediated H{sub 2} evolution by CaI. Production of H{sub 2} by CdS:CaImore » was observed only under illumination and only in the presence of a sacrificial donor. We explored the effects of the CdS:CaI molar ratio, sacrificial donor concentration, and light intensity on photocatalytic H{sub 2} production, which were interpreted on the basis of contributions to electron transfer, hole transfer, or rate of photon absorption, respectively. Each parameter was found to have pronounced effects on the CdS:CaI photocatalytic activity. Specifically, we found that under 405 nm light at an intensity equivalent to total AM 1.5 solar flux, H{sub 2} production was limited by the rate of photon absorption ({approx}1 ms{sup -1}) and not by the turnover of CaI. Complexes were capable of H{sub 2} production for up to 4 h with a total turnover number of 106 before photocatalytic activity was lost. This loss correlated with inactivation of CaI, resulting from the photo-oxidation of the CdS capping ligand MPA.« less

Application of eggshell waste for the immobilization of cadmium and lead in a contaminated soil.

PubMed

Ok, Yong Sik; Lee, Sang Soo; Jeon, Weon-Tai; Oh, Sang-Eun; Usman, Adel R A; Moon, Deok Hyun

2011-01-01

Liming materials have been used to immobilize heavy metals in contaminated soils. However, no studies have evaluated the use of eggshell waste as a source of calcium carbonate (CaCO₃) to immobilize both cadmium (Cd) and lead (Pb) in soils. This study was conducted to evaluate the effectiveness of eggshell waste on the immobilization of Cd and Pb and to determine the metal availability following various single extraction techniques. Incubation experiments were conducted by mixing 0-5% powdered eggshell waste and curing the soil (1,246 mg Pb kg⁻¹ soil and 17 mg Cd kg⁻¹ soil) for 30 days. Five extractants, 0.01 M calcium chloride (CaCl₂), 1 M CaCl₂, 0.1 M hydrochloric acid (HCl), 0.43 M acetic acid (CH₃COOH), and 0.05 M ethylendiaminetetraacetic acid (EDTA), were used to determine the extractability of Cd and Pb following treatments with CaCO₃ and eggshell waste. Generally, the extractability of Cd and Pb in the soils decreased in response to treatments with CaCO₃ and eggshell waste, regardless of extractant. Using CaCl₂ extraction, the lowest Cd concentration was achieved upon both CaCO₃ and eggshell waste treatments, while the lowest Pb concentration was observed using HCl extraction. The highest amount of immobilized Cd and Pb was extracted by CH₃COOH or EDTA in soils treated with CaCO₃ and eggshell waste, indicating that remobilization of Cd and Pb may occur under acidic conditions. Based on the findings obtained, eggshell waste can be used as an alternative to CaCO₃ for the immobilization of heavy metals in soils.

Exposure of children to metals via tap water ingestion at home: Contamination and exposure data from a nationwide survey in France.

PubMed

Le Bot, Barbara; Lucas, Jean-Paul; Lacroix, Françoise; Glorennec, Philippe

2016-09-01

29 inorganic compounds (Al, As, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Fe, Gd, K, Mg, Mn, Mo, Na, Nd, Ni, Pb, Sb, Se, Sr, Tl, U, V and Zn) were measured in the tap water of 484 representative homes of children aged 6months to 6years in metropolitan France in 2008-2009. Parents were asked whether their children consumed tap water. Sampling design and sampling weights were taken into account to estimate element concentrations in tap water supplied to the 3,581,991 homes of 4,923,058 children aged 6months to 6years. Median and 95th percentiles of concentrations in tap water were in μg/L: Al: <10, 48.3, As: 0.2, 2.1; B: <100, 100; Ba: 30.7, 149.4; Ca: 85,000, 121,700; Cd: <0.5, <0.5; Ce: <0.5, <0.5; Co: <0.5, 0.8; Cr: <5, <5; Cu: 70, 720; K: 2210, 6740; Fe: <20, 46; Mn: <5, <5; Mo: <0.5, 1.5; Na: 14,500, 66,800; Ni: <2, 10.2; Mg: 6500, 21,200; Pb: <1, 5.4; Sb: <0.5, <0.5; Se: <1, 6.7; Sr: 256.9, 1004; Tl: <0.5, <0.5; U: <0.5, 2.4; V: <1, 1; Zn: 53, 208. Of the 2,977,123 young children drinking tap water in France, some were drinking water having concentrations above the 2011 World Health Organization drinking-water quality guidelines: respectively 498 (CI 95%: 0-1484) over 700μg/L of Ba; 121,581 (CI 95%: 7091-236,070) over 50mg/L of Na; 2044 (CI 95%: 0-6132) over 70μg/L of Ni, and 78,466 (17,171-139,761) over 10μg/L of Pb. Since it is representative, this tap water contamination data can be used for integrated exposure assessment, in conjunction with diet and environmental (dust and soil) exposure data. Copyright © 2016 Elsevier Ltd. All rights reserved.

New Archeomagnetic Directional Records From Iron Age Southern Africa (ca. 425-1550 CE) and Implications for the South Atlantic Anomaly

NASA Astrophysics Data System (ADS)

Hare, Vincent J.; Tarduno, John A.; Huffman, Thomas; Watkeys, Michael; Thebe, Phenyo C.; Manyanga, Munyaradzi; Bono, Richard K.; Cottrell, Rory D.

2018-02-01

The paucity of Southern Hemisphere archeomagnetic data limits the resolution of paleosecular variation models. At the same time, important changes in the modern and historical field, including the recent dipole decay, appear to originate in this region. Here a new directional record from southern Africa is presented from analysis of Iron Age (ca. 425-1550 CE) archeological materials, which extends the regional secular variation curve back to the first millennium. Previous studies have identified a period of rapid directional change between 1225 and ˜1550 CE. The new data allow us to identify an earlier period of relatively rapid change between the sixth and seventh centuries CE. Implications for models of recurrent flux expulsion at the core-mantle boundary are discussed. In addition, we identify a possible relationship of changes recorded in these African data with archeomagnetic jerks.

Enhancement of white light emission from novel Ca3Y2Si3O12:Dy3+ phosphors with Ce3+ ion codoping

NASA Astrophysics Data System (ADS)

Bandi, Vengala Rao; Nien, Yung-Tang; Chen, In-Gann

2010-07-01

The luminescent properties of the Ce3+ or Dy3+ singly doped and Ce3+/Dy3+ codoped in Ca3Y2Si3O12 novel phosphors were investigated, which are prepared by a sol-gel method. Ce3+ doped phosphor showed a brighter and broader violet-blue color emission band with a maximum peak centered at 389 nm, which is attributed to the parity and spin allowed 5d-4f transition. Photoluminescence spectra reveals that the white color emission is originated from the mixtures of two characteristic emission bands of Dy3+ ion, viz., the 473 nm blue emission (F49/2-H615/2) and the 580 nm yellow emission (F49/2-H613/2). codoping of Ce3+ has enhanced the luminescence of Dy3+ quite significantly upon the UV excitation wavelength (242 nm) and the optimized codopant concentration of Ce3+ is found to be 3 mol %. The mechanism involved in the energy transfer between Ce3+ and Dy3+ has been elucidated by an energy level diagram. The structure and morphology of the prepared samples have been analyzed by x-ray diffraction and transmission electron microscope.

Crystal Structure, Piezoelectric and Dielectric Properties of (Li, Ce)4+, Nb5+ and Mn2+ Co-doped CaBi4Ti4O15 High-Temperature Ceramics

NASA Astrophysics Data System (ADS)

Xin, Deqiong; Chen, Qiang; Wu, Jiagang; Bao, Shaoming; Zhang, Wen; Xiao, Dingquan; Zhu, Jianguo

2016-07-01

Bismuth-layered structured ceramics Ca0.85(Li,Ce)0.075Bi4Ti4- x Nb x O15-0.01MnCO3 were prepared by the conventional solid-state reaction method. The evolution of microstructure and corresponding electrical properties were studied. All the samples presented a single bismuth layered-structural phase with m = 4, indicating that (Li, Ce)4+, Nb5+ and Mn2+ adequately enter into the pseudo-perovskite structure and form solid solutions. It was found that Ca0.85(Li,Ce)0.075Bi4Ti3.98Nb0.02O15-0.01MnCO3 (CBTLCM-0.02Nb) ceramics possess the optimum electrical properties. The piezoelectric coefficient d 33, dielectric constant ɛ r, loss tan δ, planar electromechanical coupling factor k p and Curie-temperature T C of CBTLCM-0.02Nb ceramics were found to be ˜19.6 pC/N, 160, 0.16%, 8.1% and 767°C, respectively. Furthermore, the thermal depoling behavior demonstrates that the d 33 value of x = 0.02 content remains at 16.8 pC/N after annealing at 500°C. These results suggest that the (Li, Ce)4+-, Nb5+- and Mn2+-doped CBT-based ceramics are promising candidates for high-temperature piezoelectric applications.

Relationship of HIV Reservoir Characteristics with Immune Status and Viral Rebound Kinetics in an HIV Therapeutic Vaccine Study

PubMed Central

Li, Jonathan Z.; Heisey, Andrea; Ahmed, Hayat; Wang, Hongying; Zheng, Lu; Carrington, Mary; Wrin, Terri; Schooley, Robert T.; Lederman, Michael M.; Kuritzkes, Daniel R.

2014-01-01

Objectives To evaluate the impact of therapeutic HIV vaccination on the HIV reservoir, and assess the relationship of the viral reservoir with HIV-specific immune status and viral rebound kinetics. Design Retrospective analysis of ACTG A5197, a randomized, placebo-controlled trial of a therapeutic rAd5 HIV-1 gag vaccine. Methods Participants received vaccine/placebo at weeks 0, 4, and 26 prior to a 16-week analytic treatment interruption (ATI) at week 38. Cell-associated HIV-1 RNA and DNA (CA-RNA and CA-DNA) and HIV-1 residual viremia (RV) were quantified at weeks 0, 8, and 38. HIV-specific CD4+/CD8+ activity were assessed by an intracellular cytokine staining assay. Results At study entry, CA-RNA and CA-DNA levels were correlated inversely with the numbers of HIV-specific CD4+ interferon-γ-producing cells (CA-RNA: r = −0.23, P=0.03 and CA-DNA: r = −0.28, P<0.01, N=93). Therapeutic HIV vaccination induced HIV-specific CD4+ activity, but did not significantly affect levels of CA-RNA or CA-DNA. Vaccine recipients with undetectable RV at week 8 had higher frequencies of HIV-specific CD4+ and CD8+ interferon-γ-producing cells (undetectable versus detectable RV: 277 versus 161 CD4+ cells/106 lymphocytes, P=0.03 and 1326 versus 669 CD8+ cells/106 lymphocytes, P=0.04). Pre-ATI CA-RNA and CA-DNA were associated with post-ATI plasma HIV set point (CA-RNA: r = 0.51, P<0.01 and CA-DNA: r = 0.47, P<0.01). Conclusions Vaccine-induced T-cell responses were associated with a modest transient effect on RV, but more potent immune responses and/or combination treatment with latency-reversing agents are needed to reduce the HIV reservoir. HIV reservoir measures may act as biomarkers of post-ATI viral rebound kinetics. PMID:25254301

Trapping effect on a small molecular drug with vascular-disrupting agent CA4P in rodent H22 hepatic tumor model: in vivo magnetic resonance imaging and postmortem inductively coupled plasma atomic emission spectroscopy.

PubMed

Gao, Meng; Yao, Nan; Huang, Dejian; Jiang, Cuihua; Feng, Yuanbo; Li, Yue; Lou, Bin; Peng, Fei; Sun, Ziping; Ni, Yicheng; Zhang, Jian

2015-06-01

The aim of the present study is to verify the trapping effect of combretastatin A-4-phosphate (CA4P) on small molecular drugs in rodent tumors. Mice with H22 hepatocarcinoma were randomized into groups A and B. Magnetic resonance imaging (MRI) of T1WI, T2WI, and DWI was performed as baseline. Mice in group A were injected with Gd-DTPA and PBS. Mice in group B were injected with Gd-DTPA and CA4P. All mice undergo CE-T1WI at 0 h, 3 h, 6 h, 12 h, and 24 h. Enhancing efficacy of the two groups on CE-T1WI was compared with the signal-to-noise ratio (SNR) calculated. Concentrations of gadolinium measured by ICP-AES in the tumor were compared between groups. On the early CE-T1WI, tumors were equally enhanced in both groups. On the delayed CE-T1WI, the enhancing effect of group A was weaker than that of group B. The SNR and the concentration of gadolinium within the tumor of group A were lower than that of group B at 6 h, 12 h, and 24 h after administration. This study indicates that CA4P could improve the retention of Gd-DTPA in the tumor and MRI allowed dynamically monitoring trapping effects of CA4P on local retention of Gd-DTPA as a small molecular drug.

Self-propagating high-temperature synthesis of Ce-bearing zirconolite-rich minerals using Ca(NO3)2 as the oxidant

NASA Astrophysics Data System (ADS)

Zhang, Kuibao; Wen, Guanjun; Yin, Dan; Zhang, Haibin

2015-12-01

Synroc is recognized as the second generation waste form for the immobilization of high-level radioactive waste (HLW). Zirconolite-rich (CaZrTi2O7) Synroc minerals were attempted by self-propagating high-temperature synthesis (SHS) using Fe2O3, CrO3, Ca(NO3)2 as the oxidants and Ti as the reductant. All designed reactions were ignited and sustained using Ca(NO3)2 as the oxidant, and zirconolite-rich ceramic matrices were successfully prepared with pyrochlore (Ca2Ti2O6), perovskite (CaTiO3) and rutile (TiO2) as the minor phases. The sample CN-4, which was designed using Ca(NO3)2 as the oxidant with TiO2/Ti ratio of 7:9, was readily solidified with density of 4.62 g/cm3 and Vickers hardness of 1052 HV. CeO2 was successfully stabilized by the CN-4 sample with resultant phase constituent of 2M-CaZrTi2O7 and CaTiO3.

A rule-based electronic phenotyping algorithm for detecting clinically relevant cardiovascular disease cases.

PubMed

Esteban, Santiago; Rodríguez Tablado, Manuel; Ricci, Ricardo Ignacio; Terrasa, Sergio; Kopitowski, Karin

2017-07-14

The implementation of electronic medical records (EMR) is becoming increasingly common. Error and data loss reduction, patient-care efficiency increase, decision-making assistance and facilitation of event surveillance, are some of the many processes that EMRs help improve. In addition, they show a lot of promise in terms of data collection to facilitate observational epidemiological studies and their use for this purpose has increased significantly over the recent years. Even though the quantity and availability of the data are clearly improved thanks to EMRs, still, the problem of the quality of the data remains. This is especially important when attempting to determine if an event has actually occurred or not. We sought to assess the sensitivity, specificity, and agreement level of a codes-based algorithm for the detection of clinically relevant cardiovascular (CaVD) and cerebrovascular (CeVD) disease cases, using data from EMRs. Three family physicians from the research group selected clinically relevant CaVD and CeVD terms from the international classification of primary care, Second Edition (ICPC-2), the ICD 10 version 2015 and SNOMED-CT 2015 Edition. These terms included both signs, symptoms, diagnoses and procedures associated with CaVD and CeVD. Terms not related to symptoms, signs, diagnoses or procedures of CaVD or CeVD and also those describing incidental findings without clinical relevance were excluded. The algorithm yielded a positive result if the patient had at least one of the selected terms in their medical records, as long as it was not recorded as an error. Else, if no terms were found, the patient was classified as negative. This algorithm was applied to a randomly selected sample of the active patients within the hospital's HMO by 1/1/2005 that were 40-79 years old, had at least one year of seniority in the HMO and at least one clinical encounter. Thus, patients were classified into four groups: (1) Negative patients (2) Patients with CaVD but without CeVD; (3) Patients with CeVD but without disease CaVD; (4) Patients with both diseases. To facilitate the validation process, a stratified sample was taken so that each of the groups represented approximately 25% of the sample. Manual chart review was used as the gold standard for assessing the algorithm's performance. One-third of the patients were assigned randomly to each reviewer (Cohen's kappa 0.91). Both coded and un-coded (free text) sections of the EMR were reviewed. This was done from the first present clinical note in the patients chart to the last one registered prior to 1/1/2005. The performance of the algorithm was compared against manual chart review. It yielded high sensitivity (0.99, 95% CI 0.938-0.9971) and acceptable specificity (0.86, 95% CI 0.818-0.895) for detecting cases of CaVD and CeVD combined. A qualitative analysis of the false positives and false negatives was performed. We developed a simple algorithm, using only standardized and non-standardized coded terms within an EMR that can properly detect clinically relevant events and symptoms of CaVD and CeVD. We believe that combining it with an analysis of the free text using an NLP approach would yield even better results.

Effects of fertilization, crop year, variety, and provenance factors on mineral concentrations in onions.

PubMed

Ariyama, Kaoru; Nishida, Tadashi; Noda, Tomoaki; Kadokura, Masashi; Yasui, Akemi

2006-05-03

Mineral concentrations of onions (Allium cepa L.) grown under various conditions, including factors (fertilization, crop year, variety, and provenance), were investigated to clarify how much each factor contributes to the variation of their concentrations. This was because the mineral concentrations might be affected by various factors. The ultimate goal of this study was to develop a technique to determine the geographic origins of onions by mineral composition. Samples were onions grown under various conditions at 52 fields in 18 farms in Hokkaido, Japan. Twenty-six elements (Li, Na, Mg, Al, P, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Mo, Cd, Cs, Ba, La, Ce, Nd, Gd, W, and Tl) in these samples were determined by inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry. Fertilization conditions and crop years of onions caused variations of P, Ni, Cu, Rb, Sr, Mo, Cs, and Tl concentrations in onions; different onion varieties also showed variations in numerous element concentrations. However, the variations of mineral compositions of onions by these factors were smaller than the differences between production places with a few exceptions. Furthermore, Na, Rb, and Cs in group IA of the periodic table, Ca, Sr, and Ba in group IIA, and Zn and Cd in group IIB showed similar concentration patterns by group; this result demonstrated that elements in the same periodic groups behaved similarly in terms of their absorption in onions.

Interdecadal changes in intensity of the oxygen minimum zone off Concepción, Chile (~ 36° S), over the last century

NASA Astrophysics Data System (ADS)

Srain, B.; Pantoja, S.; Sepúlveda, J.; Lange, C. B.; Muñoz, P.; Summons, R. E.; McKay, J.; Salamanca, M.

2015-10-01

We reconstructed oxygenation changes in the upwelling ecosystem off Concepción (36° S), Chile, using inorganic and organic proxies in a sediment core covering the last ca. 110 years of sedimentation in this area. Authigenic enrichments of Mo, U and Cd were observed between ca. 1935 and 1971 CE, implying a prolonged period with predominantly more reduced conditions in bottom waters and surface sediments. Significant positive correlations between redox-sensitive metals, algal sterols, biomarkers of micro-aerophilic and anaerobic microorganisms, and archaeal glycerol dialkyl glycerol tetraethers point to a tight coupling among bottom water O2 depletion and increased primary and export production. The time interval with low O2 of ca. 35 years seems to follow low-frequency interdecadal variation of the Pacific Decadal Oscillation, and it may have resulted in O2 depletion over the entire continental shelf off Concepción. Taking this together with the concurrent increase in sedimentary molecular indicators of micro-aerophilic and anaerobic microbes, we can suggest that changes in oxygenation of the water column are reflected by changes in microbial community. This study can inform our understanding of ecological consequences to projected trends in ocean deoxygenation.

CD36- and GPR120-mediated Ca²⁺ signaling in human taste bud cells mediates differential responses to fatty acids and is altered in obese mice.

PubMed

Ozdener, Mehmet Hakan; Subramaniam, Selvakumar; Sundaresan, Sinju; Sery, Omar; Hashimoto, Toshihiro; Asakawa, Yoshinori; Besnard, Philippe; Abumrad, Nada A; Khan, Naim Akhtar

2014-04-01

It is important to increase our understanding of gustatory detection of dietary fat and its contribution to fat preference. We studied the roles of the fat taste receptors CD36 and GPR120 and their interactions via Ca(2+) signaling in fungiform taste bud cells (TBC). We measured Ca(2+) signaling in human TBC, transfected with small interfering RNAs against messenger RNAs encoding CD36 and GPR120 (or control small interfering RNAs). We also studied Ca(2+) signaling in TBC from CD36(-/-) mice and from wild-type lean and obese mice. Additional studies were conducted with mouse enteroendocrine cell line STC-1 that express GPR120 and stably transfected with human CD36. We measured release of serotonin and glucagon-like peptide-1 from human and mice TBC in response to CD36 and GPR120 activation. High concentrations of linoleic acid induced Ca(2+) signaling via CD36 and GPR120 in human and mice TBC, as well as in STC-1 cells, and low concentrations induced Ca(2+) signaling via only CD36. Incubation of human and mice fungiform TBC with lineoleic acid down-regulated CD36 and up-regulated GPR120 in membrane lipid rafts. Obese mice had decreased spontaneous preference for fat. Fungiform TBC from obese mice had reduced Ca(2+) and serotonin responses, but increased release of glucagon-like peptide-1, along with reduced levels of CD36 and increased levels of GPR120 in lipid rafts. CD36 and GPR120 have nonoverlapping roles in TBC signaling during orogustatory perception of dietary lipids; these are differentially regulated by obesity. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

Comparison between nonspecific and necrosis-avid gadolinium contrast agents in vascular disrupting agent-induced necrosis of rodent tumors at 3.0T.

PubMed

Wang, Huaijun; Miranda Cona, Marlein; Chen, Feng; Li, Junjie; Yu, Jie; Feng, Yuanbo; Peeters, Ronald; De Keyzer, Frederik; Marchal, Guy; Ni, Yicheng

2011-09-01

: To compare a commercial contrast agent (CA) Dotarem and a necrosis-avid CA (NACA) for their ability to evaluate the therapeutic necrosis with a vascular disrupting agent (VDA) on magnetic resonance imaging in rodent liver tumors to determine which could better correlate with the histopathologic outcome. : After the VDA treatment, 16 rats with 32 liver rhabdomyosarcomas were randomized into Dotarem and NACA groups (n = 8 per group) for both interindividual and intraindividual comparisons. T2-weighted imaging, T1-weighted imaging (T1WI), contrast-enhanced T1-weighted imaging (CE-T1WI), and diffusion-weighted imaging were performed at baseline, after VDA treatment and CA injections. The enhancing efficacy of CAs at immediate and delayed enhancement on CE-T1WI in viable tumor and necrosis was compared. Tumor necrosis ratios calculated from NACA and Dotarem were compared and correlated with gold-standard histopathology. : On the immediate CE-T1WI, viable tumor was enhanced by either CA. On the delayed CE-T1WI at 30 minutes, both CAs failed to demarcate viable tumor from necrosis. At 24 hours post-NACA, the necrosis was clearly distinguished from viable tumor and thus derived necrosis ratio matched that from histopathology (P = 0.99); necrosis ratio from Dotarem was significantly lower than that from NACA and histopathology (P < 0.05, both), with a higher correlation of NACA than that of Dotarem with histopathology (r = 0.99 vs. r = 0.82). : NACA better evaluated VDA-induced tumor necrosis than nonspecific CA on T1WI in tumor models of rat liver. NACA showed a closer correlation with histopathology than nonspecific CA for the delineation of true necrosis. Delayed enhancement on T1WI with nonspecific CA is not suitable for the assessment of VDA-induced tumor necrosis.

Potentiation of amygdala AMPA receptor activity selectively promotes escalated alcohol self-administration in a CaMKII-dependent manner

PubMed Central

Cannady, Reginald; Fisher, Kristen R.; Graham, Caitlin; Crayle, Jesse; Besheer, Joyce; Hodge, Clyde W.

2015-01-01

Growing evidence indicates that drugs of abuse gain control over the individual by usurping glutamate-linked mechanisms of neuroplasticity in reward-related brain regions. Accordingly, we have shown that glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) activity in the amygdala is required for the positive reinforcing effects of alcohol, which underlie the initial stages of addiction. It is unknown, however, if enhanced AMPAR activity in the amygdala facilitates alcohol self-administration, which is a kernel premise of glutamate hypotheses of addiction. Here we show that low-dose alcohol (0.6 g/kg/30-min) self-administration increases phosphorylation (activation) of AMPAR subtype GluA1 S831 (pGluA1 S831) in the central amygdala (CeA), basolateral amygdala, and nucleus accumbens core (AcbC) of selectively bred alcohol-preferring P-rats as compared to behavior-matched (non-drug) sucrose controls. The functional role of enhanced AMPAR activity was assessed via site-specific infusion of the AMPAR positive modulator, aniracetam, in the CeA and AcbC prior to alcohol self-administration. Intra-CeA aniracetam increased alcohol- but not sucrose-reinforced responding, and was ineffective following intra-AcbC infusion. Since GluA1 S831 is a Ca2+/calmodulin-dependent protein kinase II (CaMKII) substrate, we sought to determine if AMPAR regulation of enhanced alcohol self-administration is dependent on CaMKII activity. Intra-CeA infusion of the cell-permeable CaMKII peptide inhibitor m-AIP dose-dependently reduced alcohol self-administration. A sub-threshold dose of m-AIP also blocked the aniracetam-induced escalation of alcohol self-administration, demonstrating that AMPAR-mediated potentiation of alcohol reinforcement requires CaMKII activity in the amygdala. Enhanced activity of plasticity-linked AMPAR-CaMKII signaling in the amygdala may promote escalated alcohol use via increased positive reinforcement during the initial stages of addiction. PMID:26742808

Activation Thermodynamics and H/D Kinetic Isotope Effect of the Hox to HredH+ Transition in [FeFe] Hydrogenase.

PubMed

Ratzloff, Michael W; Wilker, Molly B; Mulder, David W; Lubner, Carolyn E; Hamby, Hayden; Brown, Katherine A; Dukovic, Gordana; King, Paul W

2017-09-20

Molecular complexes between CdSe nanocrystals and Clostridium acetobutylicum [FeFe] hydrogenase I (CaI) enabled light-driven control of electron transfer for spectroscopic detection of redox intermediates during catalytic proton reduction. Here we address the route of electron transfer from CdSe→CaI and activation thermodynamics of the initial step of proton reduction in CaI. The electron paramagnetic spectroscopy of illuminated CdSe:CaI showed how the CaI accessory FeS cluster chain (F-clusters) functions in electron transfer with CdSe. The H ox →H red H + reduction step measured by Fourier-transform infrared spectroscopy showed an enthalpy of activation of 19 kJ mol -1 and a ∼2.5-fold kinetic isotope effect. Overall, these results support electron injection from CdSe into CaI involving F-clusters, and that the H ox →H red H + step of catalytic proton reduction in CaI proceeds by a proton-dependent process.

Insight into the optoelectronic and thermoelectric properties of Ca-based Zintl phase CaCd2X2 (X = P, As) from first principles calculation

NASA Astrophysics Data System (ADS)

Belfarh, T.; Batouche, M.; Seddik, T.; Uğur, G.; Omran, S. Bin; Bouhemadou, A.; Sandeep; Wang, Xiaotian; Sun, Xiao-Wei; Khenata, R.

2018-06-01

We have studied the structural, optical, electronic and thermoelectric properties of the CaCd2X2 (X = P, As) compounds by using the full-potential augmented plane wave plus local orbitals method (FP-APW + lo). The exchange-correlation potential was treated using both the gradient generalized approximation (WC-GGA) and local density approximation (LDA). The estimated structural parameters, including the lattice parameters and internal coordinates agree well with the available experimental data. Our computed band structure shows that both studied compounds are semiconductors, with direct band gaps (Γ-Γ) of approximately 1.78 eV and 1.2 eV for CaCd2P2 and CaCd2As2, respectively, using GGA-TB-mBJ approach. The calculated optical spectra reveal a strong response of these materials in the energy range between the visible light and extreme UV regions, making them a good candidate for optoelectronic devices. Thermoelectric parameters, such as thermal conductivity, electrical conductivity, Seebeck coefficient, power factor and figure of merit were calculated. We note that both the CaCd2P2 and CaCd2As2 compounds show promising thermoelectric properties.

Synthesis and structural studies on cerium substituted La0.4Ca0.6MnO3 as solid oxide fuel cell electrode material

NASA Astrophysics Data System (ADS)

Singh, Monika; Kumar, Dinesh; Singh, Akhilesh Kumar

2018-04-01

For solid oxide fuel cell electrode material, calcium doped lanthanum manganite La0.4Ca0.6MnO3 (LCMO) and cerium-incorporated on Ca-site with composition La0.40Ca0.55Ce0.05MnO3 (LCCMO) were synthesized using most feasible and efficient glycine-nitrate method. The formation of crystalline single phase was confirmed by x-ray diffraction (XRD). The Rietveld analysis reveals that both systems crystallize into orthorhombic crystal structure with Pnma space group. Additionally, 8 mole % Y2O3 stabilized ZrO2 (8YSZ) solid electrolyte was also synthesized using high energy ball mill to check the reaction with electrode materials. It was found that the substitution of Ce+4 cations in LCMO perovskite suppressed formation of undesired insulating CaZrO3 phase.

Short-sweep capillary electrophoresis with a selective zinc fluorescence imaging reagent FluoZin-3 for determination of free and metalothionein-2a-bound Zn2+ ions.

PubMed

Nejdl, Lukas; Moravanska, Andrea; Smerkova, Kristyna; Mravec, Filip; Krizkova, Sona; Pomorski, Adam; Krężel, Artur; Macka, Mirek; Adam, Vojtech; Vaculovicova, Marketa

2018-08-09

A capillary electrophoretic (CE) method using a short-sweep approach and laser-induced fluorescence (LIF) detection (ShortSweepCE-LIF) was developed for determination of Zn 2+ and Cd 2+ as complexes with highly selective and sensitive fluorescent probe FluoZin-3. The ShortSweepCE-LIF method, established in this work, can be used for examining competitive Zn 2+ and Cd 2+ binding properties of metalloproteins or peptides. The parameters including background electrolyte composition, injection pressure and time as well as separation voltage were investigated. Under the optimized conditions, 80 mM HEPES, pH 7.4, with 1.5 μM FluoZin-3 was used as an electrolyte, hydrodynamic injection was performed at 50 mbar for 5 s, and separation voltage of 25 kV. Limits of detection for Zn 2+ and Cd 2+ were 4 and 125 nM, respectively. The developed method was demonstrated in a study of interactions between metalothionein-2a isoform and metal ions Zn 2+ , Co 2+ and Cd 2+ . It was found that FluoZin-3 was able to extract a single Zn 2+ ion, while added Co 2+ (in surplus) extracted only 2.4 Zn 2+ ions, and Cd 2+ extracted all 7 Zn 2+ ions present in the metalothionein molecule. Copyright © 2018 Elsevier B.V. All rights reserved.

Modulation of Endoplasmic Reticulum Stress Controls CD4+ T-cell Activation and Antitumor Function.

PubMed

Thaxton, Jessica E; Wallace, Caroline; Riesenberg, Brian; Zhang, Yongliang; Paulos, Chrystal M; Beeson, Craig C; Liu, Bei; Li, Zihai

2017-08-01

The endoplasmic reticulum (ER) is an energy-sensing organelle with intimate ties to programming cell activation and metabolic fate. T-cell receptor (TCR) activation represents a form of acute cell stress and induces mobilization of ER Ca 2+ stores. The role of the ER in programming T-cell activation and metabolic fate remains largely undefined. Gp96 is an ER protein with functions as a molecular chaperone and Ca 2+ buffering protein. We hypothesized that the ER stress response may be important for CD4 + T-cell activation and that gp96 may be integral to this process. To test our hypothesis, we utilized genetic deletion of the gp96 gene Hsp90b1 in a CD4 + T cell-specific manner. We show that gp96-deficient CD4 + T cells cannot undergo activation-induced glycolysis due to defective Ca 2+ mobilization upon TCR engagement. We found that activating naïve CD4 + T cells while inhibiting ER Ca 2+ exchange, through pharmacological blockade of the ER Ca 2+ channel inositol trisphosphate receptor (IP 3 R), led to a reduction in cytosolic Ca 2+ content and generated a pool of CD62L high /CD44 low CD4 + T cells compared with wild-type (WT) matched controls. In vivo IP 3 R-inhibited CD4 + T cells exhibited elevated tumor control above WT T cells. Together, these data show that ER-modulated cytosolic Ca 2+ plays a role in defining CD4 + T-cell phenotype and function. Factors associated with the ER stress response are suitable targets for T cell-based immunotherapies. Cancer Immunol Res; 5(8); 666-75. ©2017 AACR . ©2017 American Association for Cancer Research.

Electronic self-organization in the single-layer manganite $$\\rm Pr_{1-x}Ca_{1+x}MnO4$$

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

Ye, Feng; Chi, Songxue; Fernandez-Baca, Jaime A

We use neutron scattering to investigate the doping evolution of the magnetic correlations in the single-layer manganitemore » $$\\rm Pr_{\\it 1-x}Ca_{\\it 1+x}MnO_4$$, away from the $x=0.5$ composition where the CE-type commensurate antiferromagnetic (AF) structure is stable. We find that short-range incommensurate spin correlations develop as the system is electron doped ($x<0.5$), which coexist with the CE-type AF order. This suggests that electron doping in this system induces an inhomogeneous electronic self-organization, where commensurate AF patches with $x=0.5$ are separated by electron-rich domain walls with short range magnetic correlations. This behavior is strikingly different than for the three-dimensional $$\\rm Pr_{\\it 1-x}Ca_{\\it x}MnO_3$$, where the long-range CE-type commensurate AF structure is stable over a wide range of electron or hole doping around $x=0.5$.« less

Efficiency of several leaching reagents on removal of Cu, Pb, Cd, and Zn from highly contaminated paddy soil.

PubMed

Gao, Ruili; Zhu, Pengfei; Guo, Guangguang; Hu, Hongqing; Zhu, Jun; Fu, Qingling

2016-11-01

The efficiency of five different single leaching reagents (tartaric acid (TA), citric acid (CA), CaCl 2 , FeCl 3 , EDTA) and two different composite leaching reagents (CA + FeCl 3 , CA + EDTA) on removing Cu, Pb, Zn, and Cd from contaminated paddy soil in Hunan Province (in China) was studied. The results indicated that the efficiencies of CA, FeCl 3 , and EDTA on extracting Cu, Pb, Cd, and Zn from soil were greater than that of TA and CaCl 2 , and their extraction efficiencies were EDTA ≥ FeCl 3 > CA. The efficiencies of CA + FeCl 3 on extracting Cu, Pb, Cd, and Zn were higher than that of single CA or FeCl 3 . The 25 mmol L -1 CA + 20 mmol L -1 FeCl 3 was a promising composite leaching reagent for paddy soil, and it could remove Cu (57.6 %), Pb (59.3 %), Cd (84.8 %), and Zn (28.0 %), respectively. With the same amount of leaching reagent, the efficiency of continuous leaching by several times was higher than that by once. In addition, the easily reducible and oxidizable fractions of heavy metals showed significant decrease during the process of leaching.

Probing structure-induced optical behavior in a new class of self-activated luminescent 0D/1D CaWO₄ metal oxide – CdSe nanocrystal composite heterostructures

DOE PAGES

Han, Jinkyu; McBean, Coray; Wang, Lei; ...

2015-01-30

In this report, we synthesize and characterize the structural and optical properties of novel heterostructures composed of (i) semiconducting nanocrystalline CdSe quantum dot (QDs) coupled with (ii) both one and zero-dimensional (1D and 0D) motifs of self-activated luminescence CaWO₄ metal oxides. Specifically, ~4 nm CdSe QDs have been anchored onto (i) high-aspect ratio 1D nanowires, measuring ~230 nm in diameter and ~3 μm in length, as well as onto (ii) crystalline 0D nanoparticles (possessing an average diameter of ~ 80 nm) of CaWO₄ through the mediation of 3-mercaptopropionic acid (MPA) as a connecting linker. Composite formation was confirmed by complementarymore » electron microscopy and spectroscopy (i.e. IR and Raman) data. In terms of luminescent properties, our results show that our 1D and 0D heterostructures evince photoluminescence (PL) quenching and shortened PL lifetimes of CaWO₄ as compared with unbound CaWO₄. We propose that a photo-induced electron transfer process occurs from CaWO₄ to CdSe QDs, a scenario which has been confirmed by NEXAFS measurements and which highlights a decrease in the number of unoccupied orbitals in the conduction bands of CdSe QDs. By contrast, the PL signature and lifetimes of MPA-capped CdSe QDs within these heterostructures do not exhibit noticeable changes as compared with unbound MPA-capped CdSe QDs. The striking difference in optical behavior between CaWO₄ nanostructures and CdSe QDs within our heterostructures can be correlated with the relative positions of their conduction and valence energy band levels. In addition, the PL quenching behaviors for CaWO₄ within the heterostructure configuration were examined by systematically varying (i) the quantities and coverage densities of CdSe QDs as well as (ii) the intrinsic morphology (and by extension, the inherent crystallite size) of CaWO₄ itself.« less

Calcium uptake in aquatic insects: influences of phylogeny and metals (Cd and Zn).

PubMed

Poteat, Monica D; Buchwalter, David B

2014-04-01

Calcium sequestration in the hypo-osmotic freshwater environment is imperative in maintaining calcium homeostasis in freshwater aquatic organisms. This uptake process is reported to have the unintended consequence of potentially toxic heavy metal (Cd, Zn) uptake in a variety of aquatic species. However, calcium uptake remains poorly understood in aquatic insects, the dominant invertebrate faunal group in most freshwater ecosystems. Here, we examined Ca uptake and interactions with heavy metals (Cd, Zn) at low ambient Ca levels (12.5 μmol l(-1)) in 12 aquatic insect species within Ephemerellidae (mayfly) and Hydropsychidae (caddisfly), two families differentially responsive to trace metal pollution. We found Ca uptake varied 70-fold across the 12 species studied. Body mass and clade (family) were found to significantly influence both Ca uptake and adsorption (P≤0.05). Zn and Cd uptake rate constants (ku) exhibited a strong correlation (r=0.96, P<0.0001), suggesting a shared transport system. Ca uptake failed to significantly correlate with either Zn or Cd ku values. Further, neither Zn nor Cd exhibited inhibitory effects toward Ca uptake. In fact, we saw evidence of modest stimulation of Ca uptake rates in some metal treatments. This work suggests that insects generally differ from other freshwater taxa in that aqueous Ca uptake does not appear to be compromised by Cd or Zn exposure. It is important to understand the trace metal and major ion physiology of aquatic insects because of their ecological importance and widespread use as ecological indicators.

Luminescence study of Dy or Ce activated LiCaBO3 phosphor for γ-ray and C5+ ion beam irradiation.

PubMed

Oza, Abha H; Dhoble, N S; Lochab, S P; Dhoble, S J

2015-11-01

The photoluminescence and thermoluminescence characteristics of rare earths (Dy or Ce) activated LiCaBO3 phosphors have been studied. Phosphors were synthesized by modified solid state synthesis. The phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) and thermoluminescence (TL) for structural, morphological and luminescence studies. Dy(3+) activated LiCaBO3 shows emission at 486 and 577 nm due to (4) F9/2 →(6) H15/2 and (4) F9/2 → (6) H13/2 transition, respectively, whereas the PL emission spectra of Ce(3+) activated LiCaBO3 phosphor shows a broad band peaking at 432 nm, which is due to the transition from 5d level to the ground state of the Ce(3+) ion. The thermoluminescence study was also carried out for both these phosphors for γ-ray irradiation and carbon beam irradiation. Linearity was studied for a 0.4-3.1 Rad dose γ-rays. Linear behaviour over this dose range was observed. Gamma ray-irradiated phosphors were shown to be negligible fading upon storage. All the samples were also studied for 75 MeV C(5+) ion beam exposure in the range of 3.75 × 10(12) - 7.5 × 10(13) ion cm(-2) fluence. In addition to this, trapping parameters of all the samples were also calculated using Chen's peak shape method. Copyright © 2015 John Wiley & Sons, Ltd.

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.

Osteoporotic-like effects of cadmium on bone mineral density and content in aged ovariectomized beagles

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

Sacco-Gibson, N.; Abrams, J.; Chaudhry, S.

1992-12-31

Our purpose was to evaluate the effects of ovariectomy in conjunction with cadmium (Cd) exposure on bone. Aged female beagles with {sup 45}Ca-labeled skeletons ovariectomized and exposed to Cd. Successive vertebral scans by dual photon absorptiometry monitored changes in bone mineral density (BMD) in each dog with time. Results showed that ovariectomy or Cd exposure alone caused significant decreases in BMD; ovariectomy with Cd exposure caused the greatest decrease. Ovariectomy alone did not decrease BMD in the distal end or mid-shaft of the tibia while BMD of the distal tibia decreased significantly due to Cd exposure alone. Combination treatment resultedmore » in significant decreases in BMD of both tibial regions. At necropsy, tibiae, humeri, lumbar vertebrae and ribs were obtained for biochemical analysis. No group-to-group differences in bone weights (wet, dry, ash), in ash/dry ratios, or in long bone and vertebral Ca/dry or Ca/ash ratios were observed. Significantly higher total {sup 45}Ca content and {sup 45}Ca/dry and {sup 45}Ca/ash ratios were observed in long bones and vertebrae of OV- and OV+ groups. In contrast, intact ribs showed significantly decreased Ca/dry and Ca/ash ratios compared to the SO-group. Quartered ribs demonstrated regional responses to specific treatment; decreases in total Ca content were greatest in the mid-rib region ({minus}36 to {minus}46%). Results suggest that in the aged female beagle, bone mineral loss associated with estrogen depletion is not only related to bone type (trabecular versus cortical) but also to bone Ca pools. Our results also suggest that a regional heterogeneity of bone plays a role in responsiveness to ovariectomy and Cd exposure. These aspects suggest that Cd is an exogenous factor affecting bone mineral loss independently of estrogen depletion. However, estrogen depletion primes bone for responsiveness to Cd-induced bone mineral loss.« less

Synthesis, Structure and bonding Analysis of the Polar Intermetallic Phase Ca2Pt2Cd

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

Samal, Saroj L.; Corbett, John D.

The polar intermetallic phase Ca2Pt2Cd was discovered during explorations of the Ca-Pt-Cd system. The compound was synthesized by high temperature reactions, and its structure refined by single-crystal X-ray diffraction as orthorhombic, Immm, a = 4.4514(5), b = 5.8415(6), c = 8.5976(9) Å, Z = 2. The structure formally contains infinite, planar networks of [Pt2Cd]4– along the ab plane, which can be described as tessellation of six and four-member rings of the anions, with cations stuffed between the anion layers. The infinite condensed platinum chains show a substantial long–short distortion of 0.52 Å, an appreciable difference between Ca2Pt2Cd (26 valence electrons)more » and the isotypic but regular Ca2Cu2Ga (29 VE). The relatively large cation proportion diminishes the usual dominance of polar (Pt–Cd) and 5d–5d (Pt–Pt) contributions to the total Hamilton populations.« less

Composition of plume-influenced mid-ocean ridge lavas and glasses from the Mid-Atlantic Ridge, East Pacific Rise, Galápagos Spreading Center, and Gulf of Aden

NASA Astrophysics Data System (ADS)

Kelley, Katherine A.; Kingsley, Richard; Schilling, Jean-Guy

2013-01-01

The global mid-ocean ridge system is peppered with localities where mantle plumes impinge on oceanic spreading centers. Here, we present new, high resolution and high precision data for 40 trace elements in 573 samples of variably plume-influenced mid-ocean ridge basalts from the Mid-Atlantic ridge, the Easter Microplate and Salas y Gomez seamounts, the Galápagos spreading center, and the Gulf of Aden, in addition to previously unpublished major element and isotopic data for these regions. Included in the data set are the unconventional trace elements Mo, Cd, Sn, Sb, W, and Tl, which are not commonly reported by most geochemical studies. We show variations in the ratios Mo/Ce, Cd/Dy, Sn/Sm, Sb/Ce, W/U, and Rb/Tl, which are expected not to fractionate significantly during melting or crystallization, as a function of proximity to plume-related features on these ridges. The Cd/Dy and Sn/Sm ratios show little variation with plume proximity, although higher Cd/Dy may signal increases in the role of garnet in the mantle source beneath some plumes. Globally, the Rb/Tl ratio closely approximates the La/SmN ratio, and thus provides a sensitive tracer of enriched mantle domains. The W/U ratio is not elevated at plume centers, but we find significant enrichments in W/U, and to a lesser extent the Mo/Ce and Sb/Ce ratios, at mid-ocean ridges proximal to plumes. Such enrichments may provide evidence of far-field entrainment of lower mantle material that has interacted with the core by deeply-rooted, upwelling mantle plumes.

Activation Thermodynamics and H/D Kinetic Isotope Effect of the H ox to H red H + Transition in [FeFe] Hydrogenase

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

Ratzloff, Michael W.; Wilker, Molly B.; Mulder, David W.

Molecular complexes between CdSe nanocrystals and Clostridium acetobutylicum [FeFe] hydrogenase I (CaI) enabled light-driven control of electron transfer for spectroscopic detection of redox intermediates during catalytic proton reduction. Here in this paper we address the route of electron transfer from CdSe→CaI and activation thermodynamics of the initial step of proton reduction in CaI. The electron paramagnetic spectroscopy of illuminated CdSe:CaI showed how the CaI accessory FeS cluster chain (F-clusters) functions in electron transfer with CdSe. The H ox→H redH + reduction step measured by Fourier-transform infrared spectroscopy showed an enthalpy of activation of 19 kJ mol -1 and a ~2.5-foldmore » kinetic isotope effect. Overall these results support electron injection from CdSe into CaI involving F-clusters, and that the H ox→H redH + step of catalytic proton reduction in CaI proceeds by a proton-dependent process.« less

Activation Thermodynamics and H/D Kinetic Isotope Effect of the H ox to H red H + Transition in [FeFe] Hydrogenase

DOE PAGES

Ratzloff, Michael W.; Wilker, Molly B.; Mulder, David W.; ...

2017-08-29

Molecular complexes between CdSe nanocrystals and Clostridium acetobutylicum [FeFe] hydrogenase I (CaI) enabled light-driven control of electron transfer for spectroscopic detection of redox intermediates during catalytic proton reduction. Here in this paper we address the route of electron transfer from CdSe→CaI and activation thermodynamics of the initial step of proton reduction in CaI. The electron paramagnetic spectroscopy of illuminated CdSe:CaI showed how the CaI accessory FeS cluster chain (F-clusters) functions in electron transfer with CdSe. The H ox→H redH + reduction step measured by Fourier-transform infrared spectroscopy showed an enthalpy of activation of 19 kJ mol -1 and a ~2.5-foldmore » kinetic isotope effect. Overall these results support electron injection from CdSe into CaI involving F-clusters, and that the H ox→H redH + step of catalytic proton reduction in CaI proceeds by a proton-dependent process.« less

Effects of calcium at toxic concentrations of cadmium in plants.

PubMed

Huang, Danlian; Gong, Xiaomin; Liu, Yunguo; Zeng, Guangming; Lai, Cui; Bashir, Hassan; Zhou, Lu; Wang, Dafei; Xu, Piao; Cheng, Min; Wan, Jia

2017-05-01

This review provides new insight that calcium plays important roles in plant growth, heavy metal accumulation and translocation, photosynthesis, oxidative damage and signal transduction under cadmium stress. Increasing heavy metal pollution problems have raised word-wide concerns. Cadmium (Cd), being a highly toxic metal, poses potential risks both to ecosystems and human health. Compared with conventional technologies, phytoremediation, being cost-efficient, highly stable and environment-friendly, is believed to be a promising green technology for Cd decontamination. However, Cd can be easily taken up by plants and may cause severe phytotoxicity to plants, thus limiting the efficiency of phytoremediation. Various researches are being done to investigate the effects of exogenous substances on the mitigation of Cd toxicity to plants. Calcium (Ca) is an essential plant macronutrient that involved in various plant physiological processes, such as plant growth and development, cell division, cytoplasmic streaming, photosynthesis and intracellular signaling transduction. Due to the chemical similarity between Ca and Cd, Ca may mediate Cd-induced physiological or metabolic changes in plants. Recent studies have shown that Ca could be used as an exogenous substance to protect plants against Cd stress by the alleviation of growth inhibition, regulation of metal uptake and translocation, improvement of photosynthesis, mitigation of oxidative damages and the control of signal transduction in the plants. The effects of Ca on toxic concentrations of Cd in plants are reviewed. This review also provides new insight that plants with enhanced Ca level have improved resistance to Cd stress.

Syntheses, topological analyses, and NLO-active properties of new Cd(II)/M(II) (M = Ca, Sr) metal-organic frameworks based on R-isophthalic acids (R = H, OH, and t-Bu).

PubMed

Lin, Jian-Di; Wu, Shu-Ting; Li, Zhi-Hua; Du, Shao-Wu

2010-11-28

Solvothermal syntheses of Cd(NO(3))(2)·4H(2)O and R-isophthalic acids (R = H, OH and t-Bu) in the presence of Ca(II) or Sr(II) lead to four new three-dimensional Cd(II)/Ca(II) or Cd(II)/Sr(II) heterometallic frameworks: [CdCa(m-BDC)(2)(DMF)(2)] (1), [CdSr(2)(m-BDC)(2)(NO(3))(2)(DMF)(4)] (2), [CdCa(OH-m-BDC)(2)(H(2)O)(2)]·2Me(2)NH (3), and (Me(2)NH(2))(2)[Cd(2)Ca(Bu(t)-m-BDC)(4)] (4) (m-H(2)BDC = isophthalate, OH-m-H(2)BDC = 5-hydroxyisophthalate and Bu(t)-m-H(2)BDC = 5-butylisophthalate). All of these compounds except for 4 crystallize in acentric (or chiral) space groups and the bulk materials for 1 and 3 display strong powder SHG efficiencies, approximately 1.54 and 2.31 times than that of a potassium dihydrogen phosphate (KDP) powder. Topological analyses show that 1 and 2 have structures with sxb and dia topologies, respectively, while both 3 and 4 exhibit pcu topological nets when the metal carboxylate clusters are viewed as nodes. The fluorescence properties and thermal stabilities for these compounds are also investigated.

Post-magmatic solid solutions of CaCeAl2(Fe3+ 2/3□1/3)[Si2O7][SiO4]O(OH), allanite-(Ce) and REE-bearing epidote in miarolitic pegmatites of Permian Baveno granite (Verbania, central-southern alps, Italy)

NASA Astrophysics Data System (ADS)

Guastoni, Alessandro; Nestola, Fabrizio; Schiazza, Mariangela

2017-06-01

CaCeAl2(Fe3+ 2/3□1/3)[Si2O7][SiO4]O(OH), allanite-(Ce) and rare earth element (REE)-bearing epidote occur as globular aggregates and platy prismatic crystals in miarolitic cavities in a niobium, yttrium, fluorine (NYF) granitic pegmatite at Baveno, Verbania, Southern Alps, Italy. These samples were investigated by means of an electron probe micro-analyser (EPMA) and single-crystal X-ray diffraction. Our EPMA results show that the globular aggregates have the highest REE content in the core portion and decreases to REE-bearing epidote towards the rim whereas the prismatic crystals are characterized by marked oscillatory zoning that have the highest REE contents at the rim of the crystal. The unit-cell parameters of "allanites" have an intermediate unit-cell between CaCeAl2(Fe3+ 2/3□1/3)[Si2O7][SiO4]O(OH), allanite-(Ce) and REE-free epidote, because reflect the strong chemical heterogeneity of the samples which form complete solid solutions. Hydrothermal fluids control the activity and precipitation of incompatible elements like high field strength elements (HFSE), Sc and REE by hydrous F-rich fluids below the critical temperature which allow to deposit accessory minerals in the cavities with decreasing temperature. The source of REE and Y are the sheet and REE-silicates like siderophyllite-annite, and gadolinite-(Y) which underwent partial to complete decomposition by the activity of aggressive F-rich hydrothermal fluids.

CD22 ligand-binding and signaling domains reciprocally regulate B-cell Ca2+ signaling

PubMed Central

Müller, Jennifer; Obermeier, Ingrid; Wöhner, Miriam; Brandl, Carolin; Mrotzek, Sarah; Angermüller, Sieglinde; Maity, Palash C.; Reth, Michael; Nitschke, Lars

2013-01-01

A high proportion of human B cells carry B-cell receptors (BCRs) that are autoreactive. Inhibitory receptors such as CD22 can downmodulate autoreactive BCR responses. With its extracellular domain, CD22 binds to sialic acids in α2,6 linkages in cis, on the surface of the same B cell or in trans, on other cells. Sialic acids are self ligands, as they are abundant in vertebrates, but are usually not expressed by pathogens. We show that cis-ligand binding of CD22 is crucial for the regulation of B-cell Ca2+ signaling by controlling the CD22 association to the BCR. Mice with a mutated CD22 ligand-binding domain of CD22 showed strongly reduced Ca2+ signaling. In contrast, mice with mutated CD22 immunoreceptor tyrosine-based inhibition motifs have increased B-cell Ca2+ responses, increased B-cell turnover, and impaired survival of the B cells. Thus, the CD22 ligand-binding domain has a crucial function in regulating BCR signaling, which is relevant for controlling autoimmunity. PMID:23836650

CD22 ligand-binding and signaling domains reciprocally regulate B-cell Ca2+ signaling.

PubMed

Müller, Jennifer; Obermeier, Ingrid; Wöhner, Miriam; Brandl, Carolin; Mrotzek, Sarah; Angermüller, Sieglinde; Maity, Palash C; Reth, Michael; Nitschke, Lars

2013-07-23

A high proportion of human B cells carry B-cell receptors (BCRs) that are autoreactive. Inhibitory receptors such as CD22 can downmodulate autoreactive BCR responses. With its extracellular domain, CD22 binds to sialic acids in α2,6 linkages in cis, on the surface of the same B cell or in trans, on other cells. Sialic acids are self ligands, as they are abundant in vertebrates, but are usually not expressed by pathogens. We show that cis-ligand binding of CD22 is crucial for the regulation of B-cell Ca(2+) signaling by controlling the CD22 association to the BCR. Mice with a mutated CD22 ligand-binding domain of CD22 showed strongly reduced Ca(2+) signaling. In contrast, mice with mutated CD22 immunoreceptor tyrosine-based inhibition motifs have increased B-cell Ca(2+) responses, increased B-cell turnover, and impaired survival of the B cells. Thus, the CD22 ligand-binding domain has a crucial function in regulating BCR signaling, which is relevant for controlling autoimmunity.

A new technique for promoting cyclic utilization of cyclodextrins in biotransformation.

PubMed

Shen, Yanbing; Yu, Ziqi; Yang, Xu; Wang, Fang; Luo, Jianmei; Wang, Min

2017-01-01

Cyclodextrins (CDs) can improve the productivity of steroid biotransformation by enhancing substrate solubility. CDs can be recycled by grafting them with appropriate carriers. Loofah fiber is an excellent grafting material for CDs, and can be applied to the biotransformation and recycling of β-cyclodextrin (β-CD). In this work, a technique for recycling β-CD in cortisone acetate (CA) biotransformation by Arthrobacter simplex CPCC 140451 was studied. Loofah fiber-grafted β-CD (LF-β-CD) was prepared using epichlorohydrin, which is a cross-linking agent. The grafting yield of β-CD was 74.8 mg g -1 dried fibers. LF-β-CD could increase the solubility of CA and enhance biotransformation. The initial conversion rate of CA was 1.5-fold higher than that of the blank group. LF-β-CD was also used in biocatalytic reactions for eight cycles, and it maintained the conversion ratio of CA at approximately 90%. Given the above positive results, LF-β-CD can be utilized in biotechnological recycling applications. This method can also be applied to CD derivatives and hydrophobic compounds.

Factors influencing intestinal cadmium uptake in pregnant Bangladeshi women-A prospective cohort study

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

Kippler, M.; Goessler, W.; Nermell, B.

Experimental studies indicate that zinc (Zn) and calcium (Ca) status, in addition to iron (Fe) status, affect gastrointestinal absorption of cadmium (Cd), an environmental pollutant that is toxic to kidneys, bone and endocrine systems. The aim of this study was to evaluate how various nutritional factors influence the uptake of Cd in women, particularly during pregnancy. The study was carried out in a rural area of Bangladesh, where malnutrition is prevalent and exposure to Cd via food appears elevated. The uptake of Cd was evaluated by associations between erythrocyte Cd concentrations (Ery-Cd), a marker of ongoing Cd exposure, and concentrationsmore » of nutritional markers. Blood samples, collected in early pregnancy and 6 months postpartum, were analyzed by inductively coupled plasma mass spectrometry (ICPMS). Ery-Cd varied considerably (range: 0.31-5.4 {mu}g/kg) with a median of 1.1 {mu}g/kg (approximately 0.5 {mu}g/L in whole blood) in early pregnancy. Ery-Cd was associated with erythrocyte manganese (Ery-Mn; positively), plasma ferritin (p-Ft; negatively), and erythrocyte Ca (Ery-Ca; negatively) in decreasing order, indicating common transporters for Cd, Fe and Mn. There was no evidence of Cd uptake via Zn transporters, but the association between Ery-Cd and p-Ft seemed to be dependent on adequate Zn status. On average, Ery-Cd increased significantly by 0.2 {mu}g/kg from early pregnancy to 6 months postpartum, apparently due to up-regulated divalent metal transporter 1 (DMT1). In conclusion, intestinal uptake of Cd appears to be influenced either directly or indirectly by several micronutrients, in particular Fe, Mn and Zn. The negative association with Ca may suggest that Cd inhibits the transport of Ca to blood.« less

Spatio-temporal propagation of Ca2+ signals by cyclic ADP-ribose in 3T3 cells stimulated via purinergic P2Y receptors

PubMed Central

Bruzzone, Santina; Kunerth, Svenja; Zocchi, Elena; De Flora, Antonio; Guse, Andreas H.

2003-01-01

The role of cyclic ADP-ribose in the amplification of subcellular and global Ca2+ signaling upon stimulation of P2Y purinergic receptors was studied in 3T3 fibroblasts. Either (1) 3T3 fibroblasts (CD38− cells), (2) 3T3 fibroblasts preloaded by incubation with extracellular cyclic ADP-ribose (cADPR), (3) 3T3 fibroblasts microinjected with ryanodine, or (4) 3T3 fibroblasts transfected to express the ADP-ribosyl cyclase CD38 (CD38+ cells) were used. Both preincubation with cADPR and CD38 expression resulted in comparable intracellular amounts of cyclic ADP-ribose (42.3 ± 5.2 and 50.5 ± 8.0 pmol/mg protein). P2Y receptor stimulation of CD38− cells yielded a small increase of intracellular Ca2+ concentration and a much higher Ca2+ signal in CD38-transfected cells, in cADPR-preloaded cells, or in cells microinjected with ryanodine. Confocal Ca2+ imaging revealed that stimulation of ryanodine receptors by cADPR or ryanodine amplified localized pacemaker Ca2+ signals with properties resembling Ca2+ quarks and triggered the propagation of such localized signals from the plasma membrane toward the internal environment, thereby initiating a global Ca2+ wave. PMID:14623867

The Role of CD38 in Fcγ Receptor (FcγR)-mediated Phagocytosis in Murine Macrophages*

PubMed Central

Kang, John; Park, Kwang-Hyun; Kim, Jwa-Jin; Jo, Eun-Kyeong; Han, Myung-Kwan; Kim, Uh-Hyun

2012-01-01

Phagocytosis is a crucial event in the immune system that allows cells to engulf and eliminate pathogens. This is mediated through the action of immunoglobulin (IgG)-opsonized microbes acting on Fcγ receptors (FcγR) on macrophages, which results in sustained levels of intracellular Ca2+ through the mobilization of Ca2+ second messengers. It is known that the ADP-ribosyl cyclase is responsible for the rise in Ca2+ levels after FcγR activation. However, it is unclear whether and how CD38 is involved in FcγR-mediated phagocytosis. Here we show that CD38 is recruited to the forming phagosomes during phagocytosis of IgG-opsonized particles and produces cyclic-ADP-ribose, which acts on ER Ca2+ stores, thus allowing an increase in FcγR activation-mediated phagocytosis. Ca2+ data show that pretreatment of J774A.1 macrophages with 8-bromo-cADPR, ryanodine, blebbistatin, and various store-operated Ca2+ inhibitors prevented the long-lasting Ca2+ signal, which significantly reduced the number of ingested opsonized particles. Ex vivo data with macrophages extracted from CD38−/− mice also shows a reduced Ca2+ signaling and phagocytic index. Furthermore, a significantly reduced phagocytic index of Mycobacterium bovis BCG was shown in macrophages from CD38−/− mice in vivo. This study suggests a crucial role of CD38 in FcγR-mediated phagocytosis through its recruitment to the phagosome and mobilization of cADPR-induced intracellular Ca2+ and store-operated extracellular Ca2+ influx. PMID:22396532

Hybrid Density Functional Study of the Local Structures and Energy Levels of CaAl2O4:Ce3.

PubMed

Lou, Bibo; Jing, Weiguo; Lou, Liren; Zhang, Yongfan; Yin, Min; Duan, Chang-Kui

2018-05-03

First-principles calculations were carried out for the electronic structures of Ce 3+ in calcium aluminate phosphors, CaAl 2 O 4 , and their effects on luminescence properties. Hybrid density functional approaches were used to overcome the well-known underestimation of band gaps of conventional density functional approaches and to calculate the energy levels of Ce 3+ ions more accurately. The obtained 4f-5d excitation and emission energies show good consistency with measured values. A detailed energy diagram of all three sites is obtained, which explains qualitatively all of the luminescent phenomena. With the results of energy levels calculated by combining the hybrid functional of Heyd, Scuseria, and Ernzerhof (HSE06) and the constraint occupancy approach, we are able to construct a configurational coordinate diagram to analyze the processes of capture of a hole or an electron and luminescence. This approach can be applied for systematic high-throughput calculations in predicting Ce 3+ activated luminescent materials with a moderate computing requirement.

Luminescence Properties of Ca19Ce(PO4)14:A (A = Eu3+/Tb3+/Mn2+) Phosphors with Abundant Colors: Abnormal Coexistence of Ce4+/3+-Eu3+ and Energy Transfer of Ce3+ → Tb3+/Mn2+ and Tb3+-Mn2.

PubMed

Shang, Mengmeng; Liang, Sisi; Lian, Hongzhou; Lin, Jun

2017-06-05

A series of Eu 3+ /Tb 3+ /Mn 2+ -ion-doped Ca 19 Ce(PO 4 ) 14 (CCPO) phosphors have been prepared via the conventional high-temperature solid-state reaction process. Under UV radiation, the CCPO host presents a broad blue emission band from Ce 3+ ions, which are generated during the preparation process because of the formation of deficiency. The Eu 3+ -doped CCPO phosphors can exhibit magenta to red-orange emission as a result of the abnormal coexistence of Ce 3+ /Ce 4+ /Eu 3+ and the metal-metal charge-transfer (MMCT) effect between Ce 3+ and Eu 3+ . When Tb 3+ /Mn 2+ are doped into the hosts, the samples excited with 300 nm UV light present multicolor emissions due to energy transfer (ET) from the host (Ce 3+ ) to the activators with increasing activator concentrations. The emitting colors of CCPO:Tb 3+ phosphors can be tuned from blue to green, and the CCPO:Mn 2+ phosphors can emit red light. The ET mechanism from the host (Ce 3+ ) to Tb 3+ /Mn 2+ is demonstrated to be a dipole-quadrapole interaction for Ce 3+ → Tb 3+ and an exchange interaction for Ce 3+ → Mn 2+ in CCPO:Tb 3+ /Mn 2+ . Abundant emission colors containing white emission were obtained in the Tb 3+ - and Mn 2+ -codoped CCPO phosphors through control of the levels of doped Tb 3+ and Mn 2+ ions. The white-emitted CCPO:Tb 3+ /Mn 2+ phosphor exhibited excellent thermal stability. The photoluminescence properties have shown that these materials might have potential for UV-pumped white-light-emitting diodes.

Synthesis, luminescence, and energy-transfer properties of β-Na2Ca4(PO4)2(SiO4):A (A = Eu(2+), Dy(3+), Ce(3+)/Tb(3+)) phosphors.

PubMed

Li, Kai; Shang, Mengmeng; Geng, Dongling; Lian, Hongzhou; Zhang, Yang; Fan, Jian; Lin, Jun

2014-07-07

A series of β-Na2Ca4(PO4)2(SiO4) (β-NCPS):A (A = Eu(2+), Dy(3+), Ce(3+)/Tb(3+)) phosphors were prepared via a high-temperature solid-state reaction route. The X-ray diffraction, Fourier transform infrared, photoluminescence (PL), cathodoluminescence (CL) properties, fluorescent lifetimes, and absolute quantum yield were exploited to characterize the samples. Under UV radiation, the β-NCPS:Eu(2+) phosphors present bright green emissions, and the β-NCPS:Ce(3+) phosphors show strong blue emissions, which are attributed to their 4f(6)5d(1) → 4f(7) and 5d-4f allowed transitions, respectively. The β-NCPS:Ce(3+), Tb(3+) phosphors display intense tunable color from blue to green and high absolute quantum yields (81% for β-NCPS:0.12Ce(3+) and 83% for β-NCPS:0.12Ce(3+), 0.08Tb(3+)) when excited at 365 nm. Simultaneously, the energy transfer from Ce(3+) to Tb(3+) ions is deduced from the spectral overlap between Ce(3+) emission and Tb(3+) excitation spectra and demonstrated by the change of emission spectra and decay lifetimes. Moreover, the energy-transfer mechanism from Ce(3+) to Tb(3+) ions is confirmed to be exchange interaction according to the discussion of expression from Dexter and Reisfeld. Under a low-voltage electron-beam excitation, the β-NCPS:A (A = Eu(2+), Dy(3+), Ce(3+)/Tb(3+)) phosphors exhibit their characteristic emissions, and the emission profiles of β-NCPS:Ce(3+),Tb(3+) phosphors are obviously different from those of the PL spectra; this difference might be ascribed to their different luminescence mechanisms. These results in PL and CL properties suggest that β-NCPS:A (A = Eu(2+), Dy(3+), Ce(3+)/Tb(3+)) phosphors are potential candidates for solid-state lighting and field-emission displays.

Calcium, zinc and vitamin E ameliorate cadmium-induced renal oxidative damage in albino Wistar rats.

PubMed

Adi, Pradeepkiran Jangampalli; Burra, Siva Prasad; Vataparti, Amardev Rajesh; Matcha, Bhaskar

2016-01-01

This study was aimed to examine the protective effects of supplementation with calcium + zinc (Ca + Zn) or vitamin E (Vit-E) on Cd-induced renal oxidative damage. Young albino Wistar rats (180 ± 10 g) (n = 6) control rats, Cd, Cd + Ca + Zn, and Cd + Vit-E experimental groups and the experimental period was 30 days. Rats were exposed to Cd (20 mg/kg body weight) alone treated as Cd treated group and the absence or presence of Ca + Zn (2 mg/kg each) or Vit-E (20 mg/kg body weight) supplementation treated as two separate groups. The activities of the stress marker enzymes superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and lipid peroxidase (LPx) were determined in renal mitochondrial fractions of experimental rats. We observed quantitative changes in SOD isoenzymatic patterns by non-denaturing PAGE analysis, and quantified band densities. These results showed that Cd exposure leads to decreases in SOD, CAT, GR, and GPx activities and a concomitant increase in LPx and GST activities. Ca + Zn and Vit-E administration with Cd significantly reversed Cd-induced perturbations in oxidative stress marker enzymes. However, Vit-E showed more inhibitory activity against Cd than did Ca + Zn, and it protected against Cd-induced nephrotoxicity.

Electron beam induced green luminescence and degradation study of CaS:Ce nanocrystalline phosphors for FED applications

NASA Astrophysics Data System (ADS)

Kumar, Vinay; Mishra, Varun; Biggs, M. M.; Nagpure, I. M.; Ntwaeaborwa, O. M.; Terblans, J. J.; Swart, H. C.

2010-01-01

Green luminescence and degradation of Ce 3+ doped CaS nanocrystalline phosphors were studied with a 2 keV, 10 μA electron beam in an O 2 environment. The nanophosphors were synthesized by the co-precipitation method. The samples were characterized using X-ray diffraction, Transmission electron microscopy, Scanning electron microscopy/electron dispersive X-ray spectroscopy and Photoluminescence (PL) spectroscopy. Cubic CaS with an average particle size of 42 ± 2 nm was obtained. PL emission was observed at 507 nm and a shoulder at 560 nm with an excitation wavelength of 460 nm. Auger electron spectroscopy and Cathodoluminescence (CL) were used to monitor the changes in the surface composition of the CaS:Ce 3+ nanocrystalline phosphors during electron bombardment in an O 2 environment. The effect of different oxygen pressures ranging from 1 × 10 -8 to 1 × 10 -6 Torr on the CL intensity was also investigated. A CaSO 4 layer was observed on the surface after the electron beam degradation. The CL intensity was found to decrease up to 30% of its original intensity at 1 × 10 -6 Torr oxygen pressure after an electron dose of 50 C/cm 2. The formation of oxygen defects during electron bombardment may also be responsible for the decrease in CL intensity.

Synthesis of Compositionally Defined Single-Crystalline Eu 3+ -Activated Molybdate–Tungstate Solid-Solution Composite Nanowires and Observation of Charge Transfer in a Novel Class of 1D CaMoO 4 –CaWO 4 :Eu 3+ –0D CdS/CdSe QD Nanoscale Heterostructures

DOE PAGES

Han, Jinkyu; McBean, Coray; Wang, Lei; ...

2015-02-10

As a first step, we have synthesized and optically characterized a systematic series of one-dimensional (1D) single-crystalline Eu³⁺-activated alkaline-earth metal tungstate/molybdate solid solution composite CaW₁₋ xMo xO₄ (0 ≤ ‘x’ ≤ 1) nanowires of controllable chemical composition using a modified template-directed methodology under ambient room-temperature conditions. Extensive characterization of the resulting nanowires has been performed using X-ray diffraction, electron microscopy, and optical spectroscopy. The crystallite size and single crystallinity of as-prepared 1D CaW₁₋ xMo xO₄: Eu³⁺ (0 ≤ ‘x’ ≤ 1) solid solution composite nanowires increase with increasing Mo component (‘x’). We note a clear dependence of luminescence output uponmore » nanowire chemical composition with our 1D CaW₁₋ xMo xO₄: Eu³⁺ (0 ≤ ‘x’ ≤ 1) evincing the highest photoluminescence (PL) output at ‘x’ = 0.8, amongst samples tested. Subsequently, coupled with either zero-dimensional (0D) CdS or CdSe quantum dots (QDs), we successfully synthesized and observed charge transfer processes in 1D CaW1-xMoxO4: Eu3+ (‘x’ = 0.8) – 0D QD composite nanoscale heterostructures. Our results show that CaW₁₋ xMo xO₄: Eu³⁺ (‘x’ = 0.8) nanowires give rise to PL quenching when CdSe QDs and CdS QDs are anchored onto the surfaces of 1D CaW₁₋ xMo xO₄: Eu³⁺ nanowires. The observed PL quenching is especially pronounced in CaW₁₋ xMo xO₄: Eu³⁺ (‘x’ = 0.8) – 0D CdSe QD heterostructures. Conversely, the PL output and lifetimes of CdSe and CdS QDs within these heterostructures are not noticeably altered as compared with unbound CdSe and CdS QDs. The difference in optical behavior between 1D Eu³⁺ activated tungstate and molybdate solid solution nanowires and the semiconducting 0D QDs within our heterostructures can be correlated with the relative positions of their conduction and valence energy band levels. We propose that the PL quenching can be attributed to a photo-induced electron transfer process from CaW₁₋ xMo xO₄: Eu³⁺ (‘x’ = 0.8) to both CdSe and CdS QDs, an assertion supported by complementary NEXAFS measurements.« less

Role of metal mixtures (Ca, Cu and Pb) on Cd bioaccumulation and phytochelatin production by Chlamydomonas reinhardtii.

PubMed

Abboud, Pauline; Wilkinson, Kevin J

2013-08-01

The goal of the study was to determine whether metal uptake and biological effects could be predicted by free ion concentrations when organisms were exposed to Cd and a second metal. Bioaccumulation and algal phytochelatin (PC) concentrations were determined for Chlamydomonas reinhardtii following a 6-h exposure. Bioaccumulation results, after six hours of exposure, showed that Cd uptake decreased in the presence of relatively high concentrations of Ca, Cu and Pb, however, Cd bioaccumulation increased in the presence of ca. equimolar concentrations of Cu. A good correlation was observed between the production of PCs and the amount of metals bioaccumulated for the binary mixtures of Cd-Pb and Cd-Cu, but not the Cd-Ca mixture. Overall, the results suggested that, in the case of mixtures, bioaccumulated metal rather than free ion concentrations would be a better predictor of biological effect. Copyright © 2013 Elsevier Ltd. All rights reserved.

Supported catalyst systems and method of making biodiesel products using such catalysts

DOEpatents

Kim, Manhoe; Yan, Shuli; Salley, Steven O.; Ng, K. Y. Simon

2015-10-20

A heterogeneous catalyst system, a method of preparing the catalyst system and a method of forming a biodiesel product via transesterification reactions using the catalyst system is disclosed. The catalyst system according to one aspect of the present disclosure represents a class of supported mixed metal oxides that include at least calcium oxide and another metal oxide deposited on a lanthanum oxide or cerium oxide support. Preferably, the catalysts include CaO--CeO.sub.2ZLa.sub.2O.sub.3 or CaO--La.sub.2O.sub.3/CeO.sub.2. Optionally, the catalyst may further include additional metal oxides, such as CaO--La.sub.2O.sub.3--GdOxZLa.sub.2O.sub.3.

A highly selective and simple fluorescent sensor for mercury (II) ion detection based on cysteamine-capped CdTe quantum dots synthesized by the reflux method.

PubMed

Ding, Xiaojie; Qu, Lingbo; Yang, Ran; Zhou, Yuchen; Li, Jianjun

2015-06-01

Cysteamine (CA)-capped CdTe quantum dots (QDs) (CA-CdTe QDs) were prepared by the reflux method and utilized as an efficient nano-sized fluorescent sensor to detect mercury (II) ions (Hg(2+) ). Under optimum conditions, the fluorescence quenching effect of CA-CdTe QDs was linear at Hg(2+) concentrations in the range of 6.0-450 nmol/L. The detection limit was calculated to be 4.0 nmol/L according to the 3σ IUPAC criteria. The influence of 10-fold Pb(2+) , Cu(2+) and Ag(+) on the determination of Hg(2+) was < 7% (superior to other reports based on crude QDs). Furthermore, the detection sensitivity and selectivity were much improved relative to a sensor based on the CA-CdTe QDs probe, which was prepared using a one-pot synthetic method. This CA-CdTe QDs sensor system represents a new feasibility to improve the detection performance of a QDs sensor by changing the synthesis method. Copyright © 2014 John Wiley & Sons, Ltd.

Potentiation of amygdala AMPA receptor activity selectively promotes escalated alcohol self-administration in a CaMKII-dependent manner.

PubMed

Cannady, Reginald; Fisher, Kristen R; Graham, Caitlin; Crayle, Jesse; Besheer, Joyce; Hodge, Clyde W

2017-05-01

Growing evidence indicates that drugs of abuse gain control over the individual by usurping glutamate-linked mechanisms of neuroplasticity in reward-related brain regions. Accordingly, we have shown that glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) activity in the amygdala is required for the positive reinforcing effects of alcohol, which underlie the initial stages of addiction. It is unknown, however, if enhanced AMPAR activity in the amygdala facilitates alcohol self-administration, which is a kernel premise of glutamate hypotheses of addiction. Here, we show that low-dose alcohol (0.6 g/kg/30 minutes) self-administration increases phosphorylation (activation) of AMPAR subtype GluA1 S831 (pGluA1 S831) in the central amygdala (CeA), basolateral amygdala and nucleus accumbens core (AcbC) of selectively bred alcohol-preferring P-rats as compared with behavior-matched (non-drug) sucrose controls. The functional role of enhanced AMPAR activity was assessed via site-specific infusion of the AMPAR positive modulator, aniracetam, in the CeA and AcbC prior to alcohol self-administration. Intra-CeA aniracetam increased alcohol-reinforced but not sucrose-reinforced responding and was ineffective following intra-AcbC infusion. Because GluA1 S831 is a Ca2+/calmodulin-dependent protein kinase II (CaMKII) substrate, we sought to determine if AMPAR regulation of enhanced alcohol self-administration is dependent on CaMKII activity. Intra-CeA infusion of the cell-permeable CaMKII peptide inhibitor myristolated autocamtide-2-related inhibitory peptide (m-AIP) dose-dependently reduced alcohol self-administration. A subthreshold dose of m-AIP also blocked the aniracetam-induced escalation of alcohol self-administration, demonstrating that AMPAR-mediated potentiation of alcohol reinforcement requires CaMKII activity in the amygdala. Enhanced activity of plasticity-linked AMPAR-CaMKII signaling in the amygdala may promote escalated alcohol use via increased positive reinforcement during the initial stages of addiction. © 2016 Society for the Study of Addiction.

Calcium protects Trifolium repens L. seedlings against cadmium stress.

PubMed

Wang, Chang Quan; Song, Heng

2009-09-01

The effect of calcium (Ca(2+)) on Trifolium repens L. seedlings subjected to cadmium (Cd(2+)) stress was studied by investigating plant growth and changes in activity of antioxidative enzymes. Physiological analysis was carried out on seedlings cultured for 2 weeks on half-strength Hoagland medium with Cd(2+) concentrations of 0, 400 and 600 microM, and on corresponding medium supplied with CaCl(2) (5 mM). Exposure to increasing Cd(2+) reduced the fresh weight of the upper part (stems + leaves) of the seedlings more strongly than that of the root system. In both parts of T. repens seedlings H(2)O(2) level and lipid peroxidation increased. In the upper part, Cd(2+) exposure led to a significant decrease in the activity of superoxide dismutase, catalase and glutathione peroxidase and an increase in ascorbate peroxidase activity. In contrast, the roots showed an increase in the activity of antioxidative enzymes under Cd(2+) stress. Ca(2+) addition to medium reduced the Cd(2+) accumulation, and considerably reversed the Cd(2+)-induced decrease in fresh mass as well as the changes in lipid peroxidation in the both parts of T. repens seedlings. Ca(2+) application diminished the Cd(2+) effect on the activity of antioxidative enzymes in the upper part, even though it did not significantly affect these enzymes in the roots. So the possible mechanisms for the action of Ca(2+) in Cd(2+) stress were considered to reduce Cd(2+) accumulation, alleviate lipid peroxidation and promote activity of antioxidative enzymes.

Critical Role for CD38-mediated Ca2+ Signaling in Thrombin-induced Procoagulant Activity of Mouse Platelets and Hemostasis*

PubMed Central

Mushtaq, Mazhar; Nam, Tae-Sik; Kim, Uh-Hyun

2011-01-01

CD38, a multifunctional enzyme that catalyzes the synthesis of intracellular Ca2+ messengers, cyclic ADP-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate (NAADP), is known to be expressed on platelets. However, the role of CD38 in platelets remains unclear. Our present results show that treatment of platelets with thrombin results in a rapid and sustained Ca2+ signal, resulting from a coordinated interplay of Ca2+-mobilizing messengers, inositol 1,4,5-trisphosphate, cADPR, and NAADP. By dissecting the signaling pathway using various agents, we delineated that cADPR and NAADP are sequentially produced through CD38 internalization by protein kinase C via myosin heavy chain IIA following phospholipase C activation in thrombin-induced platelets. An inositol 1,4,5-trisphosphate receptor antagonist blocked the thrombin-induced formation of cADPR and NAADP as well as Ca2+ signals. An indispensable response of platelets relying on cytosolic calcium is the surface exposure of phosphatidylserine (PS), which implicates platelet procoagulant activity. Scrutinizing this parameter reveals that CD38+/+ platelets fully express PS on the surface when stimulated with thrombin, whereas this response was decreased on CD38−/− platelets. Similarly, PS exposure and Ca2+ signals were attenuated when platelets were incubated with 8-bromo-cADPR, bafilomycin A1, and a PKC inhibitor. Furthermore, in vivo, CD38-deficient mice exhibited longer bleeding times and unstable formation of thrombus than wild type mice. These results demonstrate that CD38 plays an essential role in thrombin-induced procoagulant activity of platelets and hemostasis via Ca2+ signaling mediated by its products, cADPR and NAADP. PMID:21339289

A Set of Organizational-Climate Measures: Internal Consistency, Factor Structure, and Predictive Power.

DTIC Science & Technology

1983-10-01

E 5-- 4 5 5 5 5 5- * r 4.)Ce. 41 V V "a V V (Ai NC N NC C NCMC C NCc xC N C LUJ C ) 0 D 0 M Lc 0~ N flYN Lfl to 4/)44 (Y, LL. 41 4 4-W 0L t to 4,ia 4...tUo ) )4 ) C 4- 0 L. 1 0 4-- Li CA 0 C =4 apL 0 r -W wc -1 4- 4C- U+ d)1 4-4 C - L- U) E (1) CD (1) (1)- t0 0a L- -i CL LA- fC--A W3 07: - > " TO -- ~ * A...cninr-O 0 = (A .0 >n r -.4 0 0 i L 00 0 00 4-) 4. - 4 ,- E 0 .( CZ CJz V r CL 00

Air Pollution Study in the Republic of Moldova Using Moss Biomonitoring Technique.

PubMed

Zinicovscaia, Inga; Hramco, Constantin; Duliu, Octavian G; Vergel, Konstantin; Culicov, Otilia A; Frontasyeva, Marina V; Duca, Gheorghe

2017-02-01

Moss biomonitoring using the species Hypnum cupressiforme (Hedw.) and Pleurocarpous sp was applied to study air pollution in the Republic of Moldova. A total of 41 elements (Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Zr, Cd, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Gd, Tb, Tm, Yb, Hf, Ta, W, Pb, Th, and U) were determined by instrumental epithermal neutron activation analysis and atomic absorption spectrometry. Principal component analysis was used to identify and characterize different pollution sources. Geographical distribution maps were prepared to point out the regions most affected by air pollution and relate this to potential sources of contamination. Median values of the elements studied were compared with data from the European moss biomonitoring program. The cities of Chisinau and Balti were determined to experience particular environmental stress.

Socioecological transitions trigger fire regime shifts and modulate fire-climate interactions in the Sierra Nevada, USA, 1600-2015 CE.

PubMed

Taylor, Alan H; Trouet, Valerie; Skinner, Carl N; Stephens, Scott

2016-11-29

Large wildfires in California cause significant socioecological impacts, and half of the federal funds for fire suppression are spent each year in California. Future fire activity is projected to increase with climate change, but predictions are uncertain because humans can modulate or even override climatic effects on fire activity. Here we test the hypothesis that changes in socioecological systems from the Native American to the current period drove shifts in fire activity and modulated fire-climate relationships in the Sierra Nevada. We developed a 415-y record (1600-2015 CE) of fire activity by merging a tree-ring-based record of Sierra Nevada fire history with a 20th-century record based on annual area burned. Large shifts in the fire record corresponded with socioecological change, and not climate change, and socioecological 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 settlement (ca. 1865 CE), fire activity declined, and the strong multidecadal relationship between temperature and fire decayed and then disappeared after implementation of fire suppression (ca. 1904 CE). The amplification and buffering of fire-climate relationships by humans underscores the need for parameterizing thresholds of human- vs. climate-driven fire activity to improve the skill and value of fire-climate models for addressing the increasing fire risk in California.

Socioecological transitions trigger fire regime shifts and modulate fire–climate interactions in the Sierra Nevada, USA, 1600–2015 CE

PubMed Central

Taylor, Alan H.; Trouet, Valerie; Skinner, Carl N.; Stephens, Scott

2016-01-01

Large wildfires in California cause significant socioecological impacts, and half of the federal funds for fire suppression are spent each year in California. Future fire activity is projected to increase with climate change, but predictions are uncertain because humans can modulate or even override climatic effects on fire activity. Here we test the hypothesis that changes in socioecological systems from the Native American to the current period drove shifts in fire activity and modulated fire–climate relationships in the Sierra Nevada. We developed a 415-y record (1600–2015 CE) of fire activity by merging a tree-ring–based record of Sierra Nevada fire history with a 20th-century record based on annual area burned. Large shifts in the fire record corresponded with socioecological change, and not climate change, and socioecological 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 settlement (ca. 1865 CE), fire activity declined, and the strong multidecadal relationship between temperature and fire decayed and then disappeared after implementation of fire suppression (ca. 1904 CE). The amplification and buffering of fire–climate relationships by humans underscores the need for parameterizing thresholds of human- vs. climate-driven fire activity to improve the skill and value of fire–climate models for addressing the increasing fire risk in California. PMID:27849589

Photoemission study of absorption mechanisms in Bi2.0Sr1.8Ca0.8La0.3Cu2.1O8+δ, BaBiO3, and Nd1.85Ce0.15CuO4

NASA Astrophysics Data System (ADS)

Lindberg, P. A. P.; Shen, Z.-X.; Wells, B. O.; Dessau, D. S.; Ellis, W. P.; Borg, A.; Kang, J.-S.; Mitzi, D. B.; Lindau, I.; Spicer, W. E.; Kapitulnik, A.

1989-11-01

Photoemission measurements in the constant-final-state (absorption) mode were performed on three different classes of high-temperature superconductors Bi2.0Sr1.8Ca0.8La0.3Cu2.1O8+δ, BaBiO3, and Nd1.85Ce0.15CuO4 using synchrotron radiation from 20 to 200 eV. Absorption signals from all elements but Ce are identified. The results firmly show that the Bi 6s electrons are more delocalized in BaBiO3 than in Bi2.0Sr1.8Ca0.8La0.3Cu2.1O8+δ, in agreement with the results of band-structure calculations. Differences in the absorption signals due to O and Bi excitations between BaBiO3 and Bi2.0Sr1.8Ca0.8La0.3Cu2.1O8+δ are discussed. Delayed absorption onsets attributed to giant resonances (Ba 4d-->4f, La 4d-->4f, and Nd 4d-->4f transitions) are also reported.

Premalignant Genetic and Epigenetic Alterations in Tubal Epithelium from Women with BRCA1 Mutations

DTIC Science & Technology

2010-10-14

Homo sapiens , clone IMAGE:5590287, mRNA Unknown 1.8 .0044 3.0...RT-PCR W T -F T B 1- F T B 1 C an ce r 0 2 4 6 8 10 R el at iv e Q u an ti fi ca ti o n CDKN1C Array W T -F T B 1- F T B 1 C an ce r 0 100 200 300...S p o t In te n si ty CDKN1C RT-PCR W T -F T B 1- F T B 1 C an ce r 0.0 0.2 0.4 0.6 0.8 R el at iv e Q u an ti fi ca ti o n CYP3A5 Array W T

Influence of Ca2+ doped on structural and optical properties of RPO4 (R = Ce3+, Nd3+ and Pr3+) compounds

NASA Astrophysics Data System (ADS)

Lemdek, El Mokhtar; Benkhouja, Khalil; Touhtouh, Samira; Sbiaai, Khalid; Arbaoui, Abdezzahid; Bakasse, Mina; Hajjaji, Abdelowahed; Boughaleb, Yahia; Saez-Puche, Regino

2013-11-01

This paper investigates the effect of doping by Ca2+ ions on the structural and optical properties of RPO4 (R = Ce3+, Nd3+ and Pr3+) compounds. A simple ceramic method in air at 900 °C was used to prepare all compounds. The structural characterization of compounds was carried out by using X-ray powder diffraction (XRD) and IR spectroscopy. Optical properties were characterized by reflectance spectral data and by colorimeter. The results reveal a single monazite phase for x values up to 0.4. The lattice parameters of the synthesized samples decrease linearly with the reduction of ionic radius of the Ce3+. These rare earth phosphates based materials have a potential to be adopted for the eco-friendly colorants for paints and plastics.

Transfer of volatiles and metals from mafic to felsic magmas in composite magma chambers: An experimental study

NASA Astrophysics Data System (ADS)

Guo, Haihao; Audétat, Andreas

2017-02-01

In order to determine the behavior of metals and volatiles during intrusion of mafic magma into the base of silicic, upper crustal magma chambers, fluid-rock partition coefficients (Dfluid/rock) of Li, B, Na, S, Cl, K, Mn, Fe, Rb, Sr, Ba, Ce, Cu, Zn, Ag, Cd, Mo, As, Se, Sb, Te, W, Tl, Pb and Bi were determined experimentally at 2 kbar and 850 °C close to the solidus of mafic magma. In a first step, volatile-bearing mafic glasses were prepared by melting a natural basaltic trachyandesite in the presence of volatile-bearing fluids at 1200 °C/10 kbar in piston cylinder presses. The hydrous glasses were then equilibrated in subsequent experiments at 850 °C/2 kbar in cold-seal pressure vessels, which caused 80-90% of the melt to crystallize. After 0.5-2.0 days of equilibration, the exsolved fluid was trapped by means of in-situ fracturing in the form of synthetic fluid inclusions in quartz. Both the mafic rock residue and the fluid inclusions were subsequently analyzed by laser-ablation ICP-MS for major and trace elements. Reverse experiments were conducted by equilibrating metal-bearing aqueous solutions with rock powder and then trapping the fluid. In two additional experiments, information on relative element mobilities were obtained by reacting fluids that exsolved from crystallizing mafic magma with overlying silicic melts. The combined results suggest that under the studied conditions S, Cl, Cu, Se, Br, Cd and Te are most volatile (Dfluid/rock >10), followed by Li, B, Zn, As, Ag, Sb, Cs, W, Tl, Pb and Bi (Dfluid/rock = 1-10). Less volatile are Na, Mg, K, Ca, Mn, Fe, Rb, Sr, Mo and Rb (Dfluid/rock 0.1-1), and the least fluid-mobile elements are Al, Si, Ti, Zr, Ba and Ce (Dfluid/rock <0.1). This trend is broadly consistent with relative element volatilities determined on natural high-temperature fumarole gases, although some differences exist. Based on the volatility data and measured mineral-melt and sulfide-melt partition coefficients, volatile fluxing in felsic natural samples may be identified by Cu, Se, Te and Cd-enrichment in magmatic sulfides, and by As, Se, Cd and Bi-enrichment in magmatic apatite.

Multi-elemental analysis of Lentinula edodes mushrooms available in trade.

PubMed

Mleczek, Mirosław; Siwulski, Marek; Rzymski, Piotr; Niedzielski, Przemysław; Gąsecka, Monika; Jasińska, Agnieszka; Budzyńska, Sylwia; Budka, Anna

2017-03-04

The present study investigated the content of 62 elements in the fruiting bodies of Lentinula edodes (Shiitake mushroom) cultivated commercially in Poland on various substrates from 2007-2015. The general mean content (mg kg -1 dry weight (DW)) of the studied elements ranked in the following order: K (26,335) > P (11,015) > Mg (2,284) > Ca (607) > Na (131) > Zn (112) > Fe (69) > Mn (33) > B (32) > Rb (17) > Cu (14.5) > Al (11.2) > Te (2.9) > As (1.80) > Cd (1.76) > Ag (1.73) > Nd (1.70) > Sr (1.46) > Se (1.41) > U (1.11) > Pt (0.90) > Ce (0.80) > Ba (0.61) > Co (0.59) > Tl (0.58) > Er (0.50) > Pb (0.42) > Li (0.40) > Pr (0.39) > Ir (0.37) > In (0.35) > Mo (0.31) > Cr (0.29) > Ni (0.28) > Sb (0.26) > Re (0.24) > Ti (0.19) > Bi (0.18) > Th (0.12) > La (0.10) = Pd (0.10) > Os (0.09) = Zr (0.09) > Rh (0.08) > Ho (0.07) > Ru (0.06) > Sm (0.04) = Eu (0.04) = Tm (0.04) > Gd (0.03) > Sc (0.02) = Y (0.02) > Lu (0.01) = Yb (0.01) = V (0.01). The contents of Au, Be, Dy, Ga, Ge, Hf, and Tb were below the limits of detection (0.02, 0.02, 0.01, 0.01, 0.01, 0.01, 0.02 mg kg -1 respectively). The concentrations of Al, As, B, Ba, Ca, Cd, Cr, Er, Fe, In, Lu, Mn, Nd, Sr, Ti, Tm, and Zr were comparable over the period the mushrooms were cultivated. The study revealed that Lentinula edodes contained As and Cd at levels potentially adverse to human health. This highlights the need to monitor these elements in food products obtained from this mushroom species and ensure that only low levels of these elements are present in cultivation substrates.

Wind - Ceiling - Visibility Data at Selected Airports. Volume VIII. Northwest Region.

DTIC Science & Technology

1981-06-01

od C0.o.d DOT/Federal Aviation Administration FnlRpr Office of Aviation Policy and Plans FnlRpr 800 Independence Avenue, S.W. 14. $pnwn Agency Code...0000000000000000 0 :D m lCD o~ O) 0000000000000000 a CDCL a: CD CE cnCD 7 co . LUJ 0000000000000000o 0 Cr)- M O, - - MI0 z 7 0000 0000000000o 0.0 - ID Li 0 M

Modeling of Cd adsorption to goethite-bacteria composites

DOE PAGES

Qu, Chenchen; Ma, Mingkai; Chen, Wenli; ...

2017-11-21

The accurate modeling of heavy metal adsorption in complex systems is fundamental for risk assessments in soils and associated environments. Bacteria-iron (hydr)oxide associations in soils and sediments play a critical role in heavy metal immobilization. The reduced adsorption of heavy metals on these composites have been widely reported using the component additivity (CA) method. However, there is a lack of a mechanism model to account for these deviations. In this study, we established models for Cd adsorption on goethite-Pseudomonas putida composites at 1:1 and 5:1 mass ratios. Cadmium adsorption on the 5:1 composite was consistent with the additivity method. But,more » the CA method over predicted Cd adsorption by approximately 8% on the 1:1 composite at high Cd concentration. The deviation was corrected by adding the site blockage reactions between P. putida and goethite. Both CA and “CA-site masking” models for Cd adsorption onto the composites were in line with the ITC data. These results indicate that CA method in simulating Cd adsorption on bacteria-iron oxides composites is limited to low bacterial and Cd concentrations. Thus the interfacial complexation reactions that occur between iron (hydr)oxides and bacteria should be taken into account when high concentrations of bacteria and heavy metals are present.« less

Modeling of Cd adsorption to goethite-bacteria composites

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

Qu, Chenchen; Ma, Mingkai; Chen, Wenli

The accurate modeling of heavy metal adsorption in complex systems is fundamental for risk assessments in soils and associated environments. Bacteria-iron (hydr)oxide associations in soils and sediments play a critical role in heavy metal immobilization. The reduced adsorption of heavy metals on these composites have been widely reported using the component additivity (CA) method. However, there is a lack of a mechanism model to account for these deviations. In this study, we established models for Cd adsorption on goethite-Pseudomonas putida composites at 1:1 and 5:1 mass ratios. Cadmium adsorption on the 5:1 composite was consistent with the additivity method. But,more » the CA method over predicted Cd adsorption by approximately 8% on the 1:1 composite at high Cd concentration. The deviation was corrected by adding the site blockage reactions between P. putida and goethite. Both CA and “CA-site masking” models for Cd adsorption onto the composites were in line with the ITC data. These results indicate that CA method in simulating Cd adsorption on bacteria-iron oxides composites is limited to low bacterial and Cd concentrations. Thus the interfacial complexation reactions that occur between iron (hydr)oxides and bacteria should be taken into account when high concentrations of bacteria and heavy metals are present.« less

Role of the K(Ca)3.1 K+ channel in auricular lymph node CD4+ T-lymphocyte function of the delayed-type hypersensitivity model.

PubMed

Ohya, Susumu; Nakamura, Erina; Horiba, Sayuri; Kito, Hiroaki; Matsui, Miki; Yamamura, Hisao; Imaizumi, Yuji

2013-07-01

The intermediate-conductance Ca(2+)-activated K(+) channel (K(Ca)3.1) modulates the Ca(2+) response through the control of the membrane potential in the immune system. We investigated the role of K(Ca)3.1 on the pathogenesis of delayed-type hypersensitivity (DTH) in auricular lymph node (ALN) CD4(+) T-lymphocytes of oxazolone (Ox)-induced DTH model mice. The expression patterns of K(Ca)3.1 and its possible transcriptional regulators were compared among ALN T-lymphocytes of three groups [non-sensitized (Ox-/-), Ox-sensitized, but non-challenged (Ox+/-) and Ox-sensitized and -challenged (Ox+/+)] using real-time polymerase chain reaction, Western blotting and flow cytometry. KCa 3.1 activity was measured by whole-cell patch clamp and the voltage-sensitive dye imaging. The effects of K(Ca)3.1 blockade were examined by the administration of selective K(Ca)3.1 blockers. Significant up-regulation of K(Ca)3.1a was observed in CD4(+) T-lymphocytes of Ox+/- and Ox+/+, without any evident changes in the expression of the dominant-negative form, K(Ca)3.1b. Negatively correlated with this, the repressor element-1 silencing transcription factor (REST) was significantly down-regulated. Pharmacological blockade of K(Ca)3.1 resulted in an accumulation of the CD4(+) T-lymphocytes of Ox+/+ at the G0/G1 phase of the cell cycle, and also significantly recovered not only the pathogenesis of DTH, but also the changes in the K(Ca)3.1 expression and activity in the CD4(+) T-lymphocytes of Ox+/- and Ox+/+. The up-regulation of K(Ca)3.1a in conjunction with the down-regulation of REST may be involved in CD4(+) T-lymphocyte proliferation in the ALNs of DTH model mice; and K(Ca)3.1 may be an important target for therapeutic intervention in allergy diseases such as DTH. © 2013 The British Pharmacological Society.

Electrically driven cation exchange for in situ fabrication of individual nanostructures

DOE PAGES

Zhang, Qiubo; Yin, Kuibo; Dong, Hui; ...

2017-04-12

Cation exchange (CE) has been recognized as a particularly powerful tool for the synthesis of heterogeneous nanocrystals. Presently, CE can be divided into two categories, namely ion solvation-driven CE reaction and thermally activated CE reaction. Here we report an electrically driven CE reaction to prepare individual nanostructures inside a transmission electron microscope. During the process, Cd is eliminated due to Ohmic heating, whereas Cu + migrates into the crystal driven by the electrical field force. Contrast experiments reveal that the feasibility of electrically driven CE is determined by the structural similarity of the sulfur sublattices between the initial and finalmore » phases, and the standard electrode potentials of the active electrodes. These experimental results demonstrate a strategy for the selective growth of individual nanocrystals and provide crucial insights into understanding of the microscopic pathways leading to the formation of heterogeneous structures.« less

Decay of quadrupole-octupole 1- states in 40Ca and 140Ce

NASA Astrophysics Data System (ADS)

Derya, V.; Tsoneva, N.; Aumann, T.; Bhike, M.; Endres, J.; Gooden, M.; Hennig, A.; Isaak, J.; Lenske, H.; Löher, B.; Pietralla, N.; Savran, D.; Tornow, W.; Werner, V.; Zilges, A.

2016-03-01

Background: Two-phonon excitations originating from the coupling of two collective one-phonon states are of great interest in nuclear structure physics. One possibility to generate low-lying E 1 excitations is the coupling of quadrupole and octupole phonons. Purpose: In this work, the γ -decay behavior of candidates for the (21+⊗31-)1- state in the doubly magic nucleus 40Ca and in the heavier and semimagic nucleus 140Ce is investigated. Methods: (γ ⃗,γ') experiments have been carried out at the High Intensity γ -ray Source (HI γ S ) facility in combination with the high-efficiency γ -ray spectroscopy setup γ3 consisting of HPGe and LaBr3 detectors. The setup enables the acquisition of γ -γ coincidence data and, hence, the detection of direct decay paths. Results: In addition to the known ground-state decays, for 40Ca the decay into the 31- state was observed, while for 140Ce the direct decays into the 21+ and the 02+ state were detected. The experimentally deduced transition strengths and excitation energies are compared to theoretical calculations in the framework of EDF theory plus QPM approach and systematically analyzed for N =82 isotones. In addition, negative parities for two J =1 states in 44Ca were deduced simultaneously. Conclusions: The experimental findings together with the theoretical calculations support the two-phonon character of the 11- excitation in the light-to-medium-mass nucleus 40Ca as well as in the stable even-even N =82 nuclei.

Shape-programmed nanofabrication: understanding the reactivity of dichalcogenide precursors.

PubMed

Guo, Yijun; Alvarado, Samuel R; Barclay, Joshua D; Vela, Javier

2013-04-23

Dialkyl and diaryl dichalcogenides are highly versatile and modular precursors for the synthesis of colloidal chalcogenide nanocrystals. We have used a series of commercially available dichalcogenide precursors to unveil the molecular basis for the outcome of nanocrystal preparations, more specifically, how precursor molecular structure and reactivity affect the final shape and size of II-VI semiconductor nanocrystals. Dichalcogenide precursors used were diallyl, dibenzyl, di-tert-butyl, diisopropyl, diethyl, dimethyl, and diphenyl disulfides and diethyl, dimethyl, and diphenyl diselenides. We find that the presence of two distinctively reactive C-E and E-E bonds makes the chemistry of these precursors much richer and interesting than that of other conventional precursors such as the more common phosphine chalcogenides. Computational studies (DFT) reveal that the dissociation energy of carbon-chalcogen (C-E) bonds in dichalcogenide precursors (R-E-E-R, E=S or Se) increases in the order (R): diallyl

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.

Remediation of cadmium-contaminated paddy soils by washing with chemicals: effect of soil washing on cadmium uptake by soybean.

PubMed

Maejima, Yuji; Makino, Tomoyuki; Takano, Hiroyuki; Kamiya, Takashi; Sekiya, Naoki; Itou, Tadashi

2007-03-01

We conducted a pot experiment to evaluate the effect of soil washing with CaCl(2) on Cd absorption by two soybean cultivars. The results were as follows: (1) Soybean growth was not significantly different in washed and unwashed soils, but the seed Cd concentration for both cultivars decreased significantly, up to 25%, in the washed soils compared with the unwashed soils. (2) In the washed soils, the Cd concentration in the soil solution indicated an obviously lower value from sowing to the flowering stage; however, the change in Cd speciation was not evident in the CaCl(2)-washed soil solution. Consequently, the effect of soil washing using CaCl(2) on Cd-contaminated paddy soils can be expected to continue after a CaCl(2)-washed paddy field is converted to an upland field.

Adsorption and Desorption Characteristics of Cd2+ and Pb2+ by Micro and Nano-sized Biogenic CaCO3

PubMed Central

Liu, Renlu; Guan, Yong; Chen, Liang; Lian, Bin

2018-01-01

The purpose of this study was to elucidate the characteristics and mechanisms of adsorption and desorption for heavy metals by micro and nano-sized biogenic CaCO3 induced by Bacillus subtilis, and the pH effect on adsorption was investigated. The results showed that the adsorption characteristics of Cd2+ and Pb2+ are well described by the Langmuir adsorption isothermal equation, and the maximum adsorption amounts for Cd2+ and Pb2+ were 94.340 and 416.667 mg/g, respectively. The maximum removal efficiencies were 97% for Cd2+, 100% for Pb2+, and the desorption rate was smaller than 3%. Further experiments revealed that the biogenic CaCO3 could maintain its high adsorption capability for heavy metals within wide pH ranges (3–8). The FTIR and XRD results showed that, after the biogenic CaCO3 adsorbed Cd2+ or Pb2+, it did not produce a new phase, which indicated that biogenic CaCO3 and heavy metal ions were governed by a physical adsorption process, and the high adsorptive capacity of biogenic CaCO3 for Cd2+ and Pb2+ were mainly attributed to its large total specific surface area. The findings could improve the state of knowledge about biogenic CaCO3 formation in the environment and its potential roles in the biogeochemical cycles of heavy metals. PMID:29434577

Substantial Cd-Cd Bonding in Ca6PtCd11: A Condensed Intermetallic Phase Built of Pentagonal Cd7 and Rectangular Cd4/2Pt Pyramids

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

Gulo, Fakhili; Samal, Saroj L.; Corbett, John D.

The new trail-breaking compound Ca6PtCd11 has been synthesized and its structural and bonding properties investigated. This unusual phase features an unprecedented degree of cadmium aggregation, including linear chains, novel Cd7 PBP aggregates, and edge-shared chains of PtCd4/2 square pyramids. Manifestations of this chemistry elsewhere has evidently been precluded in earlier work by the inclusion of larger amounts of the strong d-metal bonding Au or Pt. Under the right conditions Cd seems quite effective as an open s,p-band metal.

Effect of Ce Substitution on the Magnetoresistivity and Flux Pinning Energy of the Bi2Sr2Ca1- x Ce x Cu2O8+ δ Superconductors

NASA Astrophysics Data System (ADS)

Özçelik, B.; Kaya, C.; Gündoğmuş, H.; Sotelo, A.; Madre, M. A.

2014-02-01

In this study, the effect of Ce doping on the properties of Bi2Sr2Ca1- x Ce x Cu2O8+ δ ceramic superconductors, with x=0.0, 0.01, 0.05, 0.1, and 0.25, has been investigated. Samples' precursors were prepared using the conventional solid state method and subsequently textured using the Laser Floating Zone technique. The magnetoresistance measurements were studied under various applied magnetic fields. The activation energies, irreversibility fields ( H irr ), upper critical fields ( H c2) and coherence lengths at 0 K ( ξ(0)) were calculated from the resistivity versus temperature ( ρ- T) curves, under DC magnetic fields up to 5 T. The thermally activated flux flow model has been applied in order to calculate the flux pinning energies. The results indicated that H c2(0) varied from 416.19 to 115 T and the flux pinning energies varied from 1.46 to 0.042 eV at 0 T.

T Cell Calcium Signaling Regulation by the Co-Receptor CD5

PubMed Central

Freitas, Claudia M. Tellez

2018-01-01

Calcium influx is critical for T cell effector function and fate. T cells are activated when T cell receptors (TCRs) engage peptides presented by antigen-presenting cells (APC), causing an increase of intracellular calcium (Ca2+) concentration. Co-receptors stabilize interactions between the TCR and its ligand, the peptide-major histocompatibility complex (pMHC), and enhance Ca2+ signaling and T cell activation. Conversely, some co-receptors can dampen Ca2+ signaling and inhibit T cell activation. Immune checkpoint therapies block inhibitory co-receptors, such as cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) and programmed death 1 (PD-1), to increase T cell Ca2+ signaling and promote T cell survival. Similar to CTLA-4 and PD-1, the co-receptor CD5 has been known to act as a negative regulator of T cell activation and to alter Ca2+ signaling and T cell function. Though much is known about the role of CD5 in B cells, recent research has expanded our understanding of CD5 function in T cells. Here we review these recent findings and discuss how our improved understanding of CD5 Ca2+ signaling regulation could be useful for basic and clinical research. PMID:29701673

Characterizing the interaction between enantiomers of eight psychoactive drugs and highly sulfated-β-cyclodextrin by counter-current capillary electrophoresis.

PubMed

Asensi-Bernardi, Lucía; Escuder-Gilabert, Laura; Martín-Biosca, Yolanda; Sagrado, Salvador; Medina-Hernández, María José

2014-01-01

The estimation of apparent binding constants and limit mobilities of the complexes of the enantiomers that characterize the interaction of enantiomers with chiral selectors, in this case highly sulfated β-cyclodextrin, was approached using a simple and economic electrophoretic modality, the complete filling technique (CFT) in counter-current mode. The enantiomers of eight psychoactive drugs, four antihistamines (dimethindene, promethazine, orphenadrine and terfenadine) and four antidepressants (bupropion, fluoxetine, nomifensine and viloxazine) were separated for the first time for this cyclodextrin (CD). Estimations of thermodynamic and electrophoretic enantioselectivies were also performed. Results indicate that, in general, thermodynamic enantioselectivity is the main component explaining the high resolution found, but also one case suggests that electrophoretic enantioselectivity itself is enough to obtain a satisfactory resolution. CFT results advantageous compared with conventional capillary electrophoresis (CE) and partial filling technique (PFT) for the study of the interaction between drugs and chiral selectors. It combines the use of a simple fitting model (as in CE), when the enantiomers do not exit the chiral selector plug during the separation (i.e. mobility of electroosmotic flow larger than mobility of CD), and drastic reduction of the consumption (and cost; ~99.7%) of the CD reagent (as in PFT) compared with the conventional CE. Copyright © 2013 John Wiley & Sons, Ltd.

Quantitation of underivatized branched-chain amino acids in sport nutritional supplements by capillary electrophoresis with direct or indirect UV absorbance detection.

PubMed

Qiu, Jun; Wang, Jinhao; Xu, Zhongqi; Liu, Huiqing; Ren, Jie

2017-01-01

The branched-chain amino acids (BCAAs) including leucine (Leu), isoleucine (Ile) and valine (Val) play a pivotal role in the human body. Herein, we developed capillary electrophoresis (CE) coupled with conventional UV detector to quantify underivatized BCAAs in two kinds of sport nutritional supplements. For direct UV detection at 195 nm, the BCAAs (Leu, two enantiomers of Ile and Val) were separated in a background electrolyte (BGE) consisting of 40.0 mmol/L sodium tetraborate, and 40.0 mmol/L β-cyclodextrin (β-CD) at pH 10.2. In addition, the indirect UV detection at 264 nm was achieved in a BGE of 2.0 mmol/L Na2HPO4, 10.0 mmol/L p-aminosalicylic acid (PAS) as UV absorbing probe, and 40.0 mmol/L β-CD at pH 12.2. The β-CD significantly benefited the isomeric separation of Leu, L- and D-Ile. The optimal conditions allowed the LODs (limit of detections) of direct and indirect UV absorption detection to be tens μmol/L level, which was comparable to the reported CE inline derivatization method. The RSDs (relative standard deviations) of migration time and peak area were less than 0.91% and 3.66% (n = 6). Finally, CE with indirect UV detection method was applied for the quantitation of BCAAs in two commercial sport nutritional supplements, and good recovery and precision were obtained. Such simple CE method without tedious derivatization process is feasible of quality control and efficacy evaluation of the supplemental proteins.

Quantitation of underivatized branched-chain amino acids in sport nutritional supplements by capillary electrophoresis with direct or indirect UV absorbance detection

PubMed Central

Liu, Huiqing; Ren, Jie

2017-01-01

The branched-chain amino acids (BCAAs) including leucine (Leu), isoleucine (Ile) and valine (Val) play a pivotal role in the human body. Herein, we developed capillary electrophoresis (CE) coupled with conventional UV detector to quantify underivatized BCAAs in two kinds of sport nutritional supplements. For direct UV detection at 195 nm, the BCAAs (Leu, two enantiomers of Ile and Val) were separated in a background electrolyte (BGE) consisting of 40.0 mmol/L sodium tetraborate, and 40.0 mmol/L β-cyclodextrin (β-CD) at pH 10.2. In addition, the indirect UV detection at 264 nm was achieved in a BGE of 2.0 mmol/L Na2HPO4, 10.0 mmol/L p-aminosalicylic acid (PAS) as UV absorbing probe, and 40.0 mmol/L β-CD at pH 12.2. The β-CD significantly benefited the isomeric separation of Leu, L- and D-Ile. The optimal conditions allowed the LODs (limit of detections) of direct and indirect UV absorption detection to be tens μmol/L level, which was comparable to the reported CE inline derivatization method. The RSDs (relative standard deviations) of migration time and peak area were less than 0.91% and 3.66% (n = 6). Finally, CE with indirect UV detection method was applied for the quantitation of BCAAs in two commercial sport nutritional supplements, and good recovery and precision were obtained. Such simple CE method without tedious derivatization process is feasible of quality control and efficacy evaluation of the supplemental proteins. PMID:28640882

Hematite (α-Fe2O3) - A potential Ce4+ carrier in red mud.

PubMed

Bolanz, Ralph M; Kiefer, Stefan; Göttlicher, Jörg; Steininger, Ralph

2018-05-01

Cerium is the most abundant rare earth element (REE) within the waste product of alumina production (red mud), but its speciation in this complex material is still barely understood. Previous studies showed evidence for a correlation between Ce and the main constituent of red mud, iron oxides, which led us to investigate the most abundant iron oxide in red mud, hematite, as possible carrier phase for Ce. Synthetic hematite can incorporate up to 1.70±0.01wt% Ce, which leads to a systematical increase of all unit cell parameters. Investigations by extended X-ray absorption fine structure spectroscopy suggest an incorporation of Ce 4+ O 6 into the hematite structure by a novel atomic arrangement, fundamentally different from the close-range order around Fe 3+ in hematite. Samples of red mud were taken in Lauta (Saxony), Germany and analyzed by powder X-ray diffraction, inductively coupled plasma mass and optical emission spectrometry, electron microprobe analysis and X-ray absorption near-edge structure spectroscopy. Red mud samples consist of hematite (Fe 2 O 3 ) (34-58wt%), sodalite (Na 8 Al 6 Si 6 O 24 Cl 2 ) (4-30wt%), gibbsite (Al(OH) 3 ) (0-25wt%), goethite (FeOOH) (10-23wt%), böhmite (AlOOH) (0-11wt%), rutile (TiO 2 ) (4-8wt%), cancrinite (Na 6 Ca 2 Al 6 Si 6 O 24 (CO 3 ) 2 ) (0-5wt%), nordstrandite (Al(OH) 3 ) (0-5wt%) and quartz (SiO 2 ) (0-4wt%). While the main elemental composition is Fe>Al>Na>Ti>Ca (Si not included), the average concentration of REE is 1109±6mg/kg with an average Ce concentration of 464±3mg/kg. The main carrier of Ce was located in the Fe-rich fine-grained fraction of red mud (0.10wt% Ce 2 O 3 ), while other potential Ce carriers like monazite, lead oxides, secondary Ce-minerals and particles of potentially anthropogenic origin are of subordinated relevance. Cerium in red mud occurs predominantly as Ce 4+ , which further excludes Ce 3+ minerals as relevant sources. Copyright © 2017. Published by Elsevier B.V.

Fine tuning the heavy fermion ground state: A new handle on cerium cobalt indium

NASA Astrophysics Data System (ADS)

Pham, Long D.

A Two Fluid Description of the Kondo Lattice CeCoIn5 has been extended to include additional entropy terms that were not considered in the original work by S. Nakatsuji et al. [1]. The use of a Matlab computer code was successful at iteratively solving for f, the fraction of itinerant interacting heavy quasiparticles, and showed that it converges to a temperature dependent function invariant under successive iterations. The linear specific heat coefficient, gamma, was extracted from transport consideration in conjunction with f(T) and the Kadowacki-Woods ratio to be 204mJ/mole-K2, in good agreement from heat capacity measurements of 290mJ/mole-K2 for CeCoIn 5 [32]. Antiferromagnetism has been induced in CeCoIn5 as well as its two isostructural, isovalent sister compounds CeRhIn5 and CeIrIn 5. Cadmium-doping the heavy-fermion superconductor CeCoIn5 at the percent level acts as an electronic tuning agent, sensitively shifting the balance between superconductivity and antiferromagnetism and opening new ambient-pressure phase space in the study of heavy-fermion ground states. At nominal concentrations of x>0.070, CeCo(In1-xCd x)5 displays a two phase region of antiferromagnetism coexisting with superconductivity up to x<0.15, above which no trace of superconductivity persists in specific heat. Similar results was seen in CeIr(In1-xCd x)5 where a quantum critical point (QCP) was observed, separating superconductivity from antiferromagnetism at a nominal critical concentration of x≈0.0475, while CeRh(In1-xCdx)5 goes through an incommensurate to commensurate antiferromagnetic transition nominally at x≈0.10. Amazingly, pressure completely recovers Tc in CeCo(In1-x Cdx)5 measured at nominal concentrations of x=0.10, and 0.15. Phase diagrams were constructed from specific heat and confirmed with resistivity and magnetization. An introduction to strongly correlated physics, relevant to the 115 family, will be worked out followed by a description of general techniques of synthesis and physical properties measurements central to this dissertation and in the study of material science in general.

Besides an ITIM/SHP-1-dependent pathway, CD22 collaborates with Grb2 and plasma membrane calcium-ATPase in an ITIM/SHP-1-independent pathway of attenuation of Ca2+i signal in B cells

PubMed Central

Chen, Jie; Wang, Hong; Xu, Wei-Ping; Wei, Si-Si; Li, Hui Joyce; Mei, Yun-Qing; Li, Yi-Gang; Wang, Yue-Peng

2016-01-01

CD22 is a surface immunoglobulin implicated in negative regulation of B cell receptor (BCR) signaling; particularly inhibiting intracellular Ca2+ (Ca2+i)signals. Its cytoplasmic tail contains six tyrosine residues (Y773/Y783/Y817/Y828/Y843/Y863, designated Y1~Y6 respectively), including three (Y2/5/6) lying within immunoreceptor tyrosine-based inhibitory motifs (ITIMs) that serve to recruit the protein tyrosine phosphatase SHP-1 after BCR activation-induced phosphorylation. The mechanism of inhibiting Ca2+i by CD22 has been poorly understood. Previous study demonstrated that CD22 associated with plasma membrane calcium-ATPase (PMCA) and enhanced its activity (Chen, J. et al. Nat Immunol 2004;5:651-7). The association is dependent on BCR activation-induced cytoplasmic tyrosine phosphorylation, because CD22 with either all six tyrosines mutated to phenylalanines or cytoplasmic tail truncated loses its ability to associate with PMCA. However, which individual or a group of tyrosine residues determine the association and how CD22 and PMCA interacts, are still unclear. In this study, by using a series of CD22 tyrosine mutants, we found that ITIM Y2/5/6 accounts for 34.3~37.1% Ca2+i inhibition but is irrelevant for CD22/PMCA association. Non-ITIM Y4 and its YEND motif contribute to the remaining 69.4~71.7% Ca2+i inhibition and is the binding site for PMCA-associated Grb2. Grb2, independently of BCR cross-linking, is constitutively associated with and directly binds to PMCA in both chicken and human B cells. Knockout of Grb2 by CRISPR/Cas9 completely disrupted the CD22/PMCA association. Thus, our results demonstrate for the first time that in addition to previously-identified ITIM/SHP-1-dependent pathway, CD22 holds a major pathway of negative regulation of Ca2+i signal, which is ITIM/SHP-1-independent, but Y4/Grb2/PMCA-dependent. PMID:27276708

Besides an ITIM/SHP-1-dependent pathway, CD22 collaborates with Grb2 and plasma membrane calcium-ATPase in an ITIM/SHP-1-independent pathway of attenuation of Ca2+i signal in B cells.

PubMed

Chen, Jie; Wang, Hong; Xu, Wei-Ping; Wei, Si-Si; Li, Hui Joyce; Mei, Yun-Qing; Li, Yi-Gang; Wang, Yue-Peng

2016-08-30

CD22 is a surface immunoglobulin implicated in negative regulation of B cell receptor (BCR) signaling; particularly inhibiting intracellular Ca2+ (Ca2+i)signals. Its cytoplasmic tail contains six tyrosine residues (Y773/Y783/Y817/Y828/Y843/Y863, designated Y1~Y6 respectively), including three (Y2/5/6) lying within immunoreceptor tyrosine-based inhibitory motifs (ITIMs) that serve to recruit the protein tyrosine phosphatase SHP-1 after BCR activation-induced phosphorylation. The mechanism of inhibiting Ca2+i by CD22 has been poorly understood. Previous study demonstrated that CD22 associated with plasma membrane calcium-ATPase (PMCA) and enhanced its activity (Chen, J. et al. Nat Immunol 2004;5:651-7). The association is dependent on BCR activation-induced cytoplasmic tyrosine phosphorylation, because CD22 with either all six tyrosines mutated to phenylalanines or cytoplasmic tail truncated loses its ability to associate with PMCA. However, which individual or a group of tyrosine residues determine the association and how CD22 and PMCA interacts, are still unclear. In this study, by using a series of CD22 tyrosine mutants, we found that ITIM Y2/5/6 accounts for 34.3~37.1% Ca2+i inhibition but is irrelevant for CD22/PMCA association. Non-ITIM Y4 and its YEND motif contribute to the remaining 69.4~71.7% Ca2+i inhibition and is the binding site for PMCA-associated Grb2. Grb2, independently of BCR cross-linking, is constitutively associated with and directly binds to PMCA in both chicken and human B cells. Knockout of Grb2 by CRISPR/Cas9 completely disrupted the CD22/PMCA association. Thus, our results demonstrate for the first time that in addition to previously-identified ITIM/SHP-1-dependent pathway, CD22 holds a major pathway of negative regulation of Ca2+i signal, which is ITIM/SHP-1-independent, but Y4/Grb2/PMCA-dependent.

Nuclear Microprobe using Elastic Recoil Detection (ERD) for Hydrogen Profiling in High Temperature Protonic Conductors

NASA Technical Reports Server (NTRS)

Berger, Pascal; Sayir, Ali; Berger, Marie-Helene

2004-01-01

The interaction between hydrogen and various high temperature protonic conductors (HTPC) has not been clearly understood due to poor densification and unreacted secondary phases. the melt-processing technique is used in producing fully dense simple SrCe(0.9)Y (0.10) O(3-delta) and complex Sr3Ca(1+x)Nb(2+x)O(9-delta) perovskites that can not be achieved by solid-state sintering. the possibilities of ion beam analysis have been investigated to quantify hydrogen distribution in HTPC perovskites subjected to water heat treatment. Nuclear microprobe technique is based on the interactions of a focused ion beam of MeV light ions (H-1, H-2, He-3, He-4,.) with the sample to be analyzed to determine local elemental concentrations at the cubic micrometer scale, the elastic recoil detection analysis technique (ERDA) has been carried out using He-4(+) microbeams and detecting the resulting recoil protons. Mappings of longitudinal sections of water treated SrCeO3 and Sr(Ca(1/3)Nb(2/3))O3 perovskites have been achieved, the water treatment strongly alters the surface of simple SrCe(0.9)Y(0.10)O(3-delta) perovskite. From Rutherford Back Scattering measurements (RBS), both Ce depletion and surface re-deposition is evidenced. the ERDA investigations on water treated Sr3Ca(1+x)Nb(2+x)O(9-delta) perovskite did not exhibit any spatial difference for the hydrogen incorporation from the surface to the centre. the amount of hydrogen incorporation for Sr3Ca(1+x)Nb(2+x)O(9-delta) was low and required further development of two less conventional techniques, ERDA in forward geometry and forward elastic diffusion H-1(p,p) H-1 with coincidence detection.

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.

Dipole-relaxation parameters for Ce3+-Fint- complexes in CaF2:Ce and CaF2:Ce,Mn

NASA Astrophysics Data System (ADS)

Jassemnejad, B.; McKeever, S. W. S.

1987-12-01

Dipole-relaxation parameters for Ce3+-Fint- centers (C4v symmetry) in CaF2 are calculated using the method of ionic thermocurrents (ITC). The data indicate concentration-dependent effects if analyzed using the traditional ITC equation, assuming a single value for the reorientation activation energy. This analysis is unable to account for an observed broadening of the ITC peak as more Ce is added to the crystals. However, as has been published for other MF2:R3+ systems, we find that the broadening can be successfully accounted for by adopting a modified ITC equation which allows for a Gaussian distribution of activation energies about a mean value E0 and with a distribution width p. The parameter E0 is found to be independent of dipole content while p is found to increase with increasing dipole concentration. The data are consistent with a perturbation of the dipole-relaxation parameters due to interactions with other defects within the system. However, the strength of the observed effects is difficult to explain by invoking electrostatic dipole-dipole interactions only. Other perturbations, due perhaps to monopole-dipole interactions or elastic interactions, must be taking place. The data indicate that dipole concentrations calculated by ITC will be in error in the presence of such interactions due to a reduction in the mean contribution per dipole to the overall polarization density. For samples in which interaction effects are negligible, we calculate a dipole moment of 3.12×10-29 C m. The data further indicate that that the addition of Mn to the system causes a decrease in the interaction effects via a reduction in the Ce C4v center dipole moment. It appears that the broadening of the ITC curve is sensitive to the defect structure surrounding the dipoles.

Analysis of tumour-infiltrating lymphocytes reveals two new biologically different subgroups of breast ductal carcinoma in situ.

PubMed

Beguinot, Marie; Dauplat, Marie-Melanie; Kwiatkowski, Fabrice; Lebouedec, Guillaume; Tixier, Lucie; Pomel, Christophe; Penault-Llorca, Frederique; Radosevic-Robin, Nina

2018-02-03

Tumour-infiltrating lymphocytes (TILs) have been demonstrated to significantly influence prognosis and response to therapy of invasive breast cancer (IBC). Thus, it has been suggested that TIL density or/and immunophenotype could serve as biomarkers for selection of IBC patients for immunotherapy. However, much less is known about significance of TILs in breast ductal carcinoma in situ (DCIS). We retrospectively investigated TIL density and immunophenotype in 96 pure DCIS and 35 microinvasive carcinomas (miCa). TIL density was assessed on H&E-stained breast biopsy sections as the percentage of tumour stromal area occupied by TILs, and classified into 4 grades: 0 (0%-9%), 1 (10-29%), 2 (30-49%) and 3 (50%-100%). TIL immunophenotype was assessed by immunohistochemistry for CD8, CD4, FoxP3, CD38 or CD20. Compared to pure DCIS, miCa contained significantly more cases with TIL density grade 3 (p = 0.028). Concordantly, CD8+, CD4+ and CD38+ cells were more numerous in miCa than in pure DCIS. In the pure DCIS subgroup with TIL density grades 2 and 3, all TIL subpopulations were more numerous than in the pure DCIS with TIL density grades 0 and 1, however the ratio between T-lymphocytes (CD8+ and CD4+) and B-lymphocytes (CD20+) was significantly lower (p = 0.029). On the other side, this ratio was significantly higher in miCa, in comparison with pure DCIS having TIL density grades 2 and 3 (p = 0.017). By cluster analysis of tumour cell pathobiological features we demonstrated similarity between miCa and the pure DCIS with TIL density grades 2 and 3. The only significant difference between those two categories was in the ratio of T- to B-TILs, higher in miCa. Results indicate that TIL density level can distinguish 2 biologically different DCIS subgroups, one of which (DCIS with ≥30% TILs, the TIL-rich DCIS) is like miCa. Similarity of TIL-rich pure DCIS and miCa as well as the role of B-lymphocytes in DCIS invasiveness are worth further investigating with regards to the potential development of immunotherapy-based prevention of DCIS progression.

Improving the efficiency of quantum-dot-sensitized solar cells by optimizing the growth time of the CuS counter electrode

NASA Astrophysics Data System (ADS)

Sunesh, Chozhidakath Damodharan; Gopi, Chandu V. V. M.; Muthalif, Mohammed Panthakkal Abdul; Kim, Hee-Je; Choe, Youngson

2017-09-01

CuS counter electrodes (CEs) were prepared to fabricate efficient quantum-dot-sensitized solar cells (QDSSCs) based on a CdS/CdSe photo sensitizer. The CEs were prepared on a fluorine-doped tin oxide (FTO) glass substrate by a facile chemical bath deposition (CBD) method by dissolving CuSO4·5H2O and CH3CSNH2 in water, followed by adding 0.25 mM polyvinylpyrrolidone (PVP). The CBD was performed at 60 °C for 1 h, 2 h, and 3 h, and the samples were labeled as CuS 1 h, CuS 2 h, and CuS 3 h, respectively. The QDSSCs were assembled using prepared CuS CEs and a TiO2/CdS/CdSe/ZnS photoanode, and the effect of the growth time of CuS CEs on the QDSSC performance was investigated. As the CuS growth time increases, the short-circuit current density (Jsc), fill factor (FF), and open-circuit voltage (Voc) of the QDSSCs gradually increases, leading to an enhanced power conversion efficiency (η). QDSSCs that use the CuS 2 h CE exhibit a high Jsc of 14.31 mA cm-2, Voc of 0.603 V, and FF of 0.49, which are higher than that using conventional Pt electrodes as well as CuS 1 h and CuS 3 h electrodes. The electrochemical impedance spectroscopy results show that the CuS 2 h CE exhibits an inferior charge transfer resistance of only 2.93 Ω, which is 33 times lesser than that of the Pt CE. The enhanced device performance of CuS 2 h is ascribed to the high catalytic activity and low charge transfer resistance of the CuS CE in the reduction process of oxidized polysulfide. Consequently, a superior power conversion efficiency of 4.27% is achieved for QDSSCs utilizing CuS 2 h.

Profiling calcium signals of in vitro polarized human effector CD4+ T cells.

PubMed

Kircher, Sarah; Merino-Wong, Maylin; Niemeyer, Barbara A; Alansary, Dalia

2018-06-01

Differentiation of naïve CD4 + T cells into effector subtypes with distinct cytokine profiles and physiological roles is a tightly regulated process, the imbalance of which can lead to an inadequate immune response or autoimmune disease. The crucial role of Ca 2+ signals, mainly mediated by the store operated Ca 2+ entry (SOCE) in shaping the immune response is well described. However, it is unclear if human effector CD4 + T cell subsets show differential Ca 2+ signatures in response to different stimulation methods. Herein, we provide optimized in vitro culture conditions for polarization of human CD4 + effector T cells and characterize their SOCE following both pharmacological store depletion and direct T-cell receptor (TCR) activation. Moreover, we measured whole cell Ca 2+ release activated Ca 2+ currents (I CRAC ) and investigated whether the observed differences correlate to the expression of CRAC genes. Our results show that Ca 2+ profiles of helper CD4 + Th1, Th2 and Th17 are distinct and in part shaped by the intensity of stimulation. Regulatory T cells (Treg) are unique being the subtype with the most prominent SOCE response. Analysis of in vivo differentiated Treg unraveled the role of differential expression of ORAI2 in fine-tuning signals in Treg vs. conventional CD4 + T cells. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

Preparation, characterization and molecular modeling studies of the inclusion complex of Caffeine with Beta-cyclodextrin

NASA Astrophysics Data System (ADS)

Prabu, Samikannu; Swaminathan, Meenakshisundaram; Sivakumar, Krishnamoorthy; Rajamohan, Rajaram

2015-11-01

The formation through supramolecular interaction of a host-guest inclusion complex of caffeine (CA) with nano-hydrophobic cavity beta-cyclodextrin (β-CD) is achieved by a physical mixture, a kneading method and a co-precipitation method. The formation of the inclusion complex of CA with β-CD in solution state is confirmed by UV-visible spectrophotometer, fluorescence spectrophotometer and time-resolved fluorescence spectrophotometer. The stoichiometry of the inclusion complex is 1:1; the imidazole ring and pyrimidine ring of caffeine is deeply entrapped in the beta-cyclodextrin as confirmed by spectral shifts. The Benesi-Hildebrand plot is used to calculate the binding constant of the inclusion complex of CA with β-CD at room temperature. The Gibbs free energy change of the inclusion complex process is calculated and the process is found to be spontaneous. The thermal stability of the inclusion complex of CA with β-CD is analyzed using differential scanning calorimetry. The crystal structure modification of a solid inclusion complex is confirmed by scanning electron microscopy image analysis. The formation of the inclusion complex of CA with β-CD in the solid phase is also confirmed by FT-IR and XRD. The formation of the inclusion complex between CA and β-CD, as confirmed by molecular docking studies, is in good relationship with the results obtained through different experimental methods.

Mechanochemical synthesis of magnetically hard anisotropic RFe10Si2 powders with R representing combinations of Sm, Ce and Zr

NASA Astrophysics Data System (ADS)

Gabay, A. M.; Hadjipanayis, G. C.

2017-01-01

Alloy synthesis consisting of mechanical activation followed by annealing was explored as a method of manufacturing medium-grade permanent magnet materials with a reduced content of the critical rare earth elements. Four RxFe10Si2 alloys with R=Sm, Sm0.7Zr0.3, Sm0.3Ce0.3Zr0.4 and Ce0.6Zr0.4 (nominal compositions) were prepared from mixtures of Sm2O3, CeO2, ZrO2, Fe2O3 and Si powders in the presence of a reducing agent Ca and a CaO dispersant. The collected alloy particles typically consisted of few joined submicron crystals. For R=Sm, X-ray diffraction analysis reveals a significant amount of the unwanted Th2Zn17-type compound forming alongside the desired ThMn12-type 1:12 compound. A more pure 1:12 phase could be obtained for R=Ce0.6Zr0.4, but it exhibited a room-temperature coercivity of less than 1 kOe. The most pure 1:12 phase and the highest values of the coercivity (10.8 kOe) and calculated maximum energy product (13.8 MGOe) were obtained for R=Sm0.7Zr0.3 processed at 1150 °C. The calculated maximum energy products of the Sm0.3Ce0.3Zr0.4Fe10Si2 particles, with half of their rare earths constituents represented by the relatively abundant Ce, was 10.1 MGOe.

A model predicting waterborne cadmium bioaccumulation in Gammarus pulex: the effects of dissolved organic ligands, calcium, and temperature.

PubMed

Pellet, Bastien; Geffard, Olivier; Lacour, Céline; Kermoal, Thomas; Gourlay-francé, Catherine; Tusseau-vuillemin, Marie-hélène

2009-11-01

Metal bioavailability depends on the presence of organic ligands in the water and on the concentrations of competitive cations. The present study aims at testing whether the diffusive gradient in thin films technique (DGT) could be used to take into account Cd speciation and its consequences on bioavailability in a bioaccumulation model and whether the influences of the Ca concentration and temperature also should be considered. Four kinetic experiments were conducted on Gammarus pulex: a calibration of Cd turnover rates and of the DGT lability in mineral water, a study of the influence f ethylenediaminetetraacetic acid (EDTA) and humic acids (HA) on uptake rates, and two experiments testing the influence of the Ca concentrations and temperature on Cd uptake clearance rates (ku). In mineral water, where Cd was considered fully labile, the ku was 0.46 L g⁻¹ d⁻¹, and the depuration rate was 0.032 d⁻¹. The initial Cd influxes were lowered significantly by additions of 10 μg L⁻¹ of EDTA or 10 mg L⁻¹ of HA in the water but not at 5 mg L⁻¹HA, even if DGT measurements proved that Cd formed Cd-HA complexes in that treatment. Increasing Ca concentrations lowered ku values, and a competitive inhibition model between Ca and Cd fitted the data. A 30% enhancement of k, values was observed when the temperature was increased by 8°C, which appeared comparatively as a weak effect. Thus, taking into account the metal speciation and the influence of the Ca concentration should improve Cd bioaccumulation modeling in amphipods. In freshwater, where metal bioavailability is reduced by the presence of dissolved organic matter, forecasting Cd waterborne uptake using the labile concentrations should allow robust comparisons between laboratory and field studies.

A model for trace metal sorption processes at the calcite surface: Adsorption of Cd2+ and subsequent solid solution formation

USGS Publications Warehouse

Davis, J.A.; Fuller, C.C.; Cook, A.D.

1987-01-01

The rate of Cd2+ sorption by calcite was determined as a function of pH and Mg2+ in aqueous solutions saturated with respect to calcite but undersaturated with respect to CdCO3. The sorption is characterized by two reaction steps, with the first reaching completion within 24 hours. The second step proceeded at a slow and nearly constant rate for at least 7 days. The rate of calcite recrystallization was also studied, using a Ca2+ isotopic exchange technique. Both the recrystallization rate of calcite and the rate of slow Cd2+ sorption decrease with increasing pH or with increasing Mg2+. The recrystallization rate could be predicted from the number of moles of Ca present in the hydrated surface layer. A model is presented which is consistent with the rates of Cd2+ sorption and Ca2+ isotopic exchange. In the model, the first step in Cd2+ sorption involves a fast adsorption reaction that is followed by diffusion of Cd2+ into a surface layer of hydrated CaCO3 that overlies crystalline calcite. Desorption of Cd2+ from the hydrated layer is slow. The second step is solid solution formation in new crystalline material, which grows from the disordered mixture of Cd and Ca carbonate in the hydrated surface layer. Calculated distribution coefficients for solid solutions formed at the surface are slightly greater than the ratio of equilibrium constants for dissolution of calcite and CdCO3, which is the value that would be expected for an ideal solid solution in equilibrium with the aqueous solution. ?? 1987.

Interactions of Stress and CRF in Ethanol-Withdrawal Induced Anxiety in Adolescent and Adult Rats

PubMed Central

Wills, Tiffany A.; Knapp, Darin J.; Overstreet, David H.; Breese, George R.

2010-01-01

Background Repeated stress or administration of corticotropin-releasing factor (CRF) prior to ethanol exposure sensitizes anxiety-like behavior in adult rats. Current experiments determined whether adolescent rats were more sensitive to these challenges in sensitizing ethanol withdrawal-induced anxiety and altering CRF levels in brain during withdrawal. Methods Male adult and adolescent Sprague–Dawley rats were restraint stressed (1 hour) twice 1 week apart prior to a single 5-day cycle of ethanol diet (ED; stress/withdrawal paradigm). Other rats received control diet (CD) and three 1-hour restraint stress sessions. Rats were then tested 5, 24, or 48 hours after the final withdrawal for anxiety-like behavior in the social interaction (SI) test. In other experiments, adolescent rats were given two microinjections of CRF icv 1 week apart followed by 5-days of either CD or ED and tested in social interaction 5 hours into withdrawal. Finally, CRF immunoreactivity was measured in the central nucleus of the amygdala (CeA) and paraventricular nucleus (PVN) after rats experienced control diet, repeated ethanol withdrawals, or stress/withdrawal. Results Rats of both ages had reduced SI following the stress/withdrawal paradigm, and this effect recovered within 24 hours. Higher CRF doses were required to reduce SI in adolescents than previously reported in adults. CRF immunohistochemical levels were higher in the PVN and CeA of CD-exposed adolescents. In adolescent rats, repeated ethanol withdrawals decreased CRF in the CeA but was not associated with decreased CRF cell number. There was no change in CRF from adult treatments. Conclusions In the production of anxiety-like behavior, adolescent rats have equal sensitivity with stress and lower sensitivity with CRF compared to adults. Further, adolescents had higher basal levels of CRF within the PVN and CeA and reduced CRF levels following repeated ethanol withdrawals. This reduced CRF within the CeA could indicate increased release of CRF, and future work will determine how this change relates to behavior. PMID:20586753

Carboxymethyl Hyaluronan-Stabilized Nanoparticles for Anticancer Drug Delivery.

PubMed

Woodman, Jessica L; Suh, Min Sung; Zhang, Jianxing; Kondaveeti, Yuvabharath; Burgess, Diane J; White, Bruce A; Prestwich, Glenn D; Kuhn, Liisa T

2015-01-01

Carboxymethyl hyaluronic acid (CMHA) is a semisynthetic derivative of HA that is recognized by HA binding proteins but contains an additional carboxylic acid on some of the 6-hydroxyl groups of the N-acetyl glucosamine sugar units. These studies tested the ability of CMHA to stabilize the formation of calcium phosphate nanoparticles and evaluated their potential to target therapy resistant, CD44(+)/CD24(-/low) human breast cancer cells (BT-474EMT). CMHA stabilized particles (nCaP(CMHA)) were loaded with the chemotherapy drug cis-diamminedichloroplatinum(II) (CDDP) to form nCaP(CMHA)CDDP. nCaP(CMHA)CDDP was determined to be poorly crystalline hydroxyapatite, 200 nm in diameter with a -43 mV zeta potential. nCaP(CMHA)CDDP exhibited a two-day burst release of CDDP that tapered resulting in 86% release by 7 days. Surface plasmon resonance showed that nCaP(CMHA)CDDP binds to CD44, but less effectively than CMHA or hyaluronan. nCaP(CMHA-AF488) was taken up by CD44(+)/CD24(-) BT-474EMT breast cancer cells within 18 hours. nCaP(CMHA)CDDP was as cytotoxic as free CDDP against the BT-474EMT cells. Subcutaneous BT-474EMT tumors were more reproducibly inhibited by a near tumor dose of 2.8 mg/kg CDDP than a 7 mg/kg dose nCaP(CMHA)CDDP. This was likely due to a lack of distribution of nCaP(CMHA)CDDP throughout the dense tumor tissue that limited drug diffusion.

Mitochondrial Ca2+ and membrane potential, an alternative pathway for Interleukin 6 to regulate CD4 cell effector function

PubMed Central

Yang, Rui; Lirussi, Dario; Thornton, Tina M; Jelley-Gibbs, Dawn M; Diehl, Sean A; Case, Laure K; Madesh, Muniswamy; Taatjes, Douglas J; Teuscher, Cory; Haynes, Laura; Rincón, Mercedes

2015-01-01

IL-6 plays an important role in determining the fate of effector CD4 cells and the cytokines that these cells produce. Here we identify a novel molecular mechanism by which IL-6 regulates CD4 cell effector function. We show that IL-6-dependent signal facilitates the formation of mitochondrial respiratory chain supercomplexes to sustain high mitochondrial membrane potential late during activation of CD4 cells. Mitochondrial hyperpolarization caused by IL-6 is uncoupled from the production of ATP by oxidative phosphorylation. However, it is a mechanism to raise the levels of mitochondrial Ca2+ late during activation of CD4 cells. Increased levels of mitochondrial Ca2+ in the presence of IL-6 are used to prolong Il4 and Il21 expression in effector CD4 cells. Thus, the effect of IL-6 on mitochondrial membrane potential and mitochondrial Ca2+ is an alternative pathway by which IL-6 regulates effector function of CD4 cells and it could contribute to the pathogenesis of inflammatory diseases. DOI: http://dx.doi.org/10.7554/eLife.06376.001 PMID:25974216

Enhanced Sorption of PAHs in Natural-Fire-Impacted Sediments from Oriole Lake, California

EPA Science Inventory

Surface sediment cores from Oriole Lake (CA) were analyzed for organic carbon (OC), black carbon (BC), and their δ13C isotope ratios. Sediments displayed high OC(20-25%) and increasing BC concentrations from ∼0.40% (in 1800 C.E.) to ∼0.60% dry weight (in 2000 C.E.). Petrographic...

Optically pumped cerium-doped LiSrAlF{sub 6} and LiCaAlF{sub 6}

DOEpatents

Marshall, C.D.; Payne, S.A.; Krupke, W.F.

1996-05-14

Ce{sup 3+}-doped LiSrAlF{sub 6} crystals are pumped by ultraviolet light which is polarized along the c axis of the crystals to effectively energize the laser system. In one embodiment, the polarized fourth harmonic light output from a conventional Nd:YAG laser operating at 266 nm is arranged to pump Ce:LiSrAlF{sub 6} with the pump light polarized along the c axis of the crystal. The Ce:LiSrAlF{sub 6} crystal may be placed in a laser cavity for generating tunable coherent ultraviolet radiation in the range of 280-320 nm. Additionally, Ce-doped crystals possessing the LiSrAlF{sub 6} type of chemical formula, e.g. Ce-doped LiCaAlF{sub 6} and LiSrGaF{sub 6}, can be used. Alternative pump sources include an ultraviolet-capable krypton or argon laser, or ultraviolet emitting flashlamps. The polarization of the pump light will impact operation. The laser system will operate efficiently when light in the 280-320 nm gain region is injected or recirculated in the system such that the beam is also polarized along the c axis of the crystal. The Ce:LiSrAlF{sub 6} laser system can be configured to generate ultrashort pulses, and it may be used to pump other devices, such as an optical parametric oscillator. 10 figs.

Optically pumped cerium-doped LiSrAlF.sub.6 and LiCaAlF.sub.6

DOEpatents

Marshall, Christopher D.; Payne, Stephen A.; Krupke, William F.

1996-01-01

Ce.sup.3+ -doped LiSrAlF.sub.6 crystals are pumped by ultraviolet light which is polarized along the c axis of the crystals to effectively energize the laser system. In one embodiment, the polarized fourth harmonic light output from a conventional Nd:YAG laser operating at 266 nm is arranged to pump Ce:LiSrAlF.sub.6 with the pump light polarized along the c axis of the crystal. The Ce:LiSrAlF.sub.6 crystal may be placed in a laser cavity for generating tunable coherent ultraviolet radiation in the range of 280-320 nm. Additionally, Ce-doped crystals possessing the LiSrAlF.sub.6 type of chemical formula, e.g. Ce-doped LiCaAlF.sub.6 and LiSrGaF.sub.6, can be used. Alternative pump sources include an ultraviolet-capable krypton or argon laser, or ultraviolet emitting flashlamps. The polarization of the pump light will impact operation. The laser system will operate efficiently when light in the 280-320 nm gain region is injected or recirculated in the system such that the beam is also polarized along the c axis of the crystal. The Ce:LiSrAlF.sub.6 laser system can be configured to generate ultrashort pulses, and it may be used to pump other devices, such as an optical parametric oscillator.

Emission properties of Ce-doped alkaline earth borate glasses for scintillator applications

NASA Astrophysics Data System (ADS)

Torimoto, Aya; Masai, Hirokazu; Okada, Go; Kawaguchi, Noriaki; Yanagida, Takayuki

2017-11-01

We investigate the photoluminescence (PL) and X-ray-induced luminescence properties of 0.1 mol% Ce-doped MO-B2O3 (M = Ca, Sr, and Ba) glasses. We also determine the Ce3+/(Ce3++Ce4+) ratio by X-ray absorption near-edge structure analyses. The emission intensities of PL, X-ray scintillation, and thermally stimulated luminescence (TSL) depend on the host glass composition. The order of the PL intensity from highest to lowest is as follows: Ca-substituted glass, Ba-substituted glass, and Sr-substituted glass. Our results suggest that the optical absorption edge and quantum yield (QY) are influenced by the local coordination state of Ce3+, which, in turn, is likely to be affected by the optical basicity. The order of the X-ray scintillation intensity from highest to lowest is reverse of that of the PL intensity. This is probably because the interaction probability of X-rays with matter depends on the effective atomic number of the material and the effective atomic number has a stronger influence on the scintillation intensity than does the QY. Though the TSL glow curves reveal that the density and energy depth of the trap sites depend on the substituted alkaline earth oxides, we are unable to correlate the electron spin resonance (ESR) spectra with the TSL results. Therefore, it is considered that the ESR active sites are not responsible for the TSL in these systems.

Synaptic plasticity and spatial working memory are impaired in the CD mouse model of Williams-Beuren syndrome.

PubMed

Borralleras, Cristina; Mato, Susana; Amédée, Thierry; Matute, Carlos; Mulle, Christophe; Pérez-Jurado, Luis A; Campuzano, Victoria

2016-08-02

Mice heterozygous for a complete deletion (CD) equivalent to the most common deletion found in individuals with Williams-Beuren syndrome (WBS) recapitulate relevant features of the neurocognitive phenotype, such as hypersociability, along with some neuroanatomical alterations in specific brain areas. However, the pathophysiological mechanisms underlying these phenotypes still remain largely unknown. We have studied the synaptic function and cognition in CD mice using hippocampal slices and a behavioral test sensitive to hippocampal function. We have found that long-term potentiation (LTP) elicited by theta burst stimulation (TBS) was significantly impaired in hippocampal field CA1 of CD animals. This deficit might be associated with the observed alterations in spatial working memory. However, we did not detect changes in presynaptic function, LTP induction mechanisms or AMPA and NMDA receptor function. Reduced levels of Brain-derived neurotrophic factor (BDNF) were present in the CA1-CA3 hippocampal region of CD mice, which could account for LTP deficits in these mice. Taken together, these results suggest a defect of CA1 synapses in CD mice to sustain synaptic strength after stimulation. These data represent the first description of synaptic functional deficits in CD mice and further highlights the utility of the CD model to study the mechanisms underlying the WBS neurocognitive profile.

Crystal Chemical Substitution at Ca and La Sites in CaLa4(SiO4)3O To Design the Composition Ca1- xM xLa4-xRE x(SiO4)3O for Nuclear Waste Immobilization and Its Influence on the Thermal Expansion Behavior.

PubMed

Ravikumar, Ramya; Gopal, Buvaneswari; Jena, Hrudananda

2018-06-04

The oxysilicate apatite host CaLa 4 (SiO 4 ) 3 O has been explored for immobilization of radioactive nuclides. Divalent ion, trivalent rare earth ion, and combined ionic substitutions in the silicate oxyapatite were carried out to optimize the simulated wasteform composition. The phases were characterized by powder X-ray diffraction, FT-IR, TGA, SEM-EDS, and HT-XRD techniques. The results revealed the effect of ionic substitutions on the structure and thermal expansion behavior. The investigation resulted in the formulation of simulated wasteforms such as La 3.4 Ce 0.1 Pr 0.1 Nd 0.1 Sm 0.1 Gd 0.1 Y 0.1 (SiO 4 ) 3 O (WF-1) and Ca 0.8 Sr 0.1 Pb 0.1 La 3.4 Ce 0.1 Pr 0.1 Nd 0.1 Sm 0.1 Gd 0.1 Y 0.1 (SiO 4 ) 3 O (WF-2). In comparison to the average axial thermal expansion coefficients of the hexagonal unit cell of the parent CaLa 4 (SiO 4 ) 3 O measured in the temperature range 298-1073 K (α' a = 9.74 × 10 -6 K -1 and α' c = 10.10 × 10 -6 K -1 ), rare earth ion substitution decreases the thermal expansion coefficients, as in the case of La 3.4 Ce 0.1 Pr 0.1 Nd 0.1 Sm 0.1 Gd 0.1 Y 0.1 (SiO 4 ) 3 O (α' a = 8.67 × 10 -6 K -1 and α' c = 7.94 × 10 -6 K -1 ). However, the phase Ca 0.8 Sr 0.1 Pb 0.1 La 3.4 Ce 0.1 Pr 0.1 Nd 0.1 Sm 0.1 Gd 0.1 Y 0.1 (SiO 4 ) 3 O shows an increase in the values of thermal expansion coefficients: α' a = 11.74 × 10 -6 K -1 and α' c = 11.70 × 10 -6 K -1 .

Development of an embryotoxicity test for Enchytraeus crypticus--the effect of Cd.

PubMed

Gonçalves, Micael F M; Bicho, Rita C; Rêma, Alexandra; Soares, Amadeu M V M; Faustino, Augusto M R; Amorim, Mónica J B

2015-11-01

The existing standard enchytraeid reproduction test (ERT) concerns the assessment of effects on survival and reproduction. In the present study we optimized and propose an embryotoxicity test using Enchytraeus crypticus. Cadmium (Cd) was used as a test substance. Endpoints evaluated were embryo development, number of embryonic structures, Calcium (Ca) channels quantification and hatching success with macroscopic monitoring, histological and immunohistochemistry analysis. Results showed that Cd is embryotoxic for this species, causing a decrease in the hatching success (EC50=3.1mg/kg), a delay or disruption in formation of embryonic structures depending on concentrations (<5mg Cd/kg or ⩾16mg Cd/kg). Results from immunohistochemistry suggest a competitive binding between Cd and Ca for Ca channels, resulting in changes in Ca homeostasis. The use of the E. crypticus embryotoxicity test with the combination of histological and immunohistological tools provided a good option towards mechanistic information enhancing the importance of these tests to evaluate the hazard of chemicals and possible use in risk assessment. Copyright © 2015 Elsevier Ltd. All rights reserved.

New insights into organic-inorganic hybrid perovskite CH₃NH₃PbI₃ nanoparticles. An experimental and theoretical study of doping in Pb²⁺ sites with Sn²⁺, Sr²⁺, Cd²⁺ and Ca²⁺.

PubMed

Navas, Javier; Sánchez-Coronilla, Antonio; Gallardo, Juan Jesús; Hernández, Norge Cruz; Piñero, Jose Carlos; Alcántara, Rodrigo; Fernández-Lorenzo, Concha; De los Santos, Desireé M; Aguilar, Teresa; Martín-Calleja, Joaquín

2015-04-14

This paper presents the synthesis of the organic-inorganic hybrid perovskite, CH3NH3PbI3, doped in the Pb(2+) position with Sn(2+), Sr(2+), Cd(2+) and Ca(2+). The incorporation of the dopants into the crystalline structure was analysed, observing how the characteristics of the dopant affected properties such as the crystalline phase, emission and optical properties. XRD showed how doping with Sn(2+), Sr(2+) and Cd(2+) did not modify the normal tetragonal phase. When doping with Ca(2+), the cubic phase was obtained. Moreover, DR-UV-Vis spectroscopy showed how the band gap decreased with the dopants, the values following the trend Sr(2+) < Cd(2+) < Ca(2+) < CH3NH3PbI3 ≈ Sn(2+). The biggest decrease was generated by Sr(2+), which reduced the CH3NH3PbI3 value by 4.5%. In turn, cathodoluminescence (CL) measurements confirmed the band gap obtained. Periodic-DFT calculations were performed to understand the experimental structures. The DOS analysis confirmed the experimental results obtained using UV-Vis spectroscopy, with the values calculated following the trend Sn(2+) ≈ Pb(2+) > Cd(2+) > Sr(2+) for the tetragonal structure and Pb(2+) > Ca(2+) for the cubic phase. The electron localization function (ELF) analysis showed similar electron localizations for undoped and Sn(2+)-doped tetragonal structures, which were different from those doped with Sr(2+) and Cd(2+). Furthermore, when Cd(2+) was incorporated, the Cd-I interaction was strengthened. For Ca(2+) doping, the Ca-I interaction had a greater ionic nature than Cd-I. Finally, an analysis based on the non-covalent interaction (NCI) index is presented to determine the weak-type interactions of the CH3NH3 groups with the dopant and I atoms. To our knowledge, this kind of analysis with these hybrid systems has not been performed previously.

Sodium alginate-grafted β-cyclodextrins as a matrix for immobilized Arthrobacter simplex for cortisone acetate biotransfromation

NASA Astrophysics Data System (ADS)

Shen, Yanbing; Niu, Lulu; Yu, Ziqi; Wang, Min; Shang, Zhihua; Yang, Yan

2018-06-01

Cyclodextrins (CDs) are used to resolve the low aqueous solubility of steroids, but the high cost of CDs is still a limiting factor in biotransformation process. This study, which is based on grafting and immobilization techniques, focused on synthesizing for the first time sodium alginate (SA)-grafted β-CD (SA-β-CD) and alginate-grafted β-CD for the immobilization of Arthrobacter simplex (ASP) cells (SA-β-CD-cells) and subsequent recycling of CDs and cells. FTIR spectium and X-ray diffraction proved that β-CD was successfully grafted with SA, whereas the grafting yield of β-CD was 10.3 μmol g-1. SA-β-CD could increase the solubility of CA by 3.5-fold, whereas the transformation rate was enhanced by 10%. The conversion ratio of CA was over 92% after the SA-β-CD recycling for nine cycles. In addition, after SA-β-CD-cells were applied in biocatalytic reactions for eight cycles, the conversion ratio of CA was over 90%. These advantages suggest great potential for using both grafting and immobilized techniques in steroid transformation.

Remediation of cadmium- and lead-contaminated agricultural soil by composite washing with chlorides and citric acid.

PubMed

Li, Yu-jiao; Hu, Peng-jie; Zhao, Jie; Dong, Chang-xun

2015-04-01

Composite washing of cadmium (Cd)- and lead (Pb)-contaminated agricultural soil from Hunan province in China using mixtures of chlorides (FeCl3, CaCl2) and citric acid (CA) was investigated. The concentrations of composite washing agents for metal removal were optimized. Sequential extraction was conducted to study the changes in metal fractions after soil washing. The removal of two metals at optimum concentration was reached. Using FeCl3 mixed with CA, 44% of Cd and 23% of Pb were removed, and 49 and 32% by CaCl2 mixed with CA, respectively. The mechanism of composite washing was postulated. A mixture of chlorides and CA enhanced metal extraction from soil through the formation of metal-chloride and metal-citrate complexes. CA in extract solutions promoted the formation of metal-chloride complexes and reduced the solution pH. Composite washing reduced Cd and Pb in Fe-Mn oxide forms significantly. Chlorides and CA exerted a synergistic effect on metal extraction during composite washing.

Cluster dynamics transcending chemical dynamics toward nuclear fusion

PubMed Central

Heidenreich, Andreas; Jortner, Joshua; Last, Isidore

2006-01-01

Ultrafast cluster dynamics encompasses femtosecond nuclear dynamics, attosecond electron dynamics, and electron-nuclear dynamics in ultraintense laser fields (peak intensities 1015–1020 W·cm−2). Extreme cluster multielectron ionization produces highly charged cluster ions, e.g., (C4+(D+)4)n and (D+I22+)n at IM = 1018 W·cm−2, that undergo Coulomb explosion (CE) with the production of high-energy (5 keV to 1 MeV) ions, which can trigger nuclear reactions in an assembly of exploding clusters. The laser intensity and the cluster size dependence of the dynamics and energetics of CE of (D2)n, (HT)n, (CD4)n, (DI)n, (CD3I)n, and (CH3I)n clusters were explored by electrostatic models and molecular dynamics simulations, quantifying energetic driving effects, and kinematic run-over effects. The optimization of table-top dd nuclear fusion driven by CE of deuterium containing heteroclusters is realized for light-heavy heteroclusters of the largest size, which allows for the prevalence of cluster vertical ionization at the highest intensity of the laser field. We demonstrate a 7-orders-of-magnitude enhancement of the yield of dd nuclear fusion driven by CE of light-heavy heteroclusters as compared with (D2)n clusters of the same size. Prospective applications for the attainment of table-top nucleosynthesis reactions, e.g., 12C(P,γ)13N driven by CE of (CH3I)n clusters, were explored. PMID:16740666

Cluster dynamics transcending chemical dynamics toward nuclear fusion.

PubMed

Heidenreich, Andreas; Jortner, Joshua; Last, Isidore

2006-07-11

Ultrafast cluster dynamics encompasses femtosecond nuclear dynamics, attosecond electron dynamics, and electron-nuclear dynamics in ultraintense laser fields (peak intensities 10(15)-10(20) W.cm(-2)). Extreme cluster multielectron ionization produces highly charged cluster ions, e.g., (C(4+)(D(+))(4))(n) and (D(+)I(22+))(n) at I(M) = 10(18) W.cm(-2), that undergo Coulomb explosion (CE) with the production of high-energy (5 keV to 1 MeV) ions, which can trigger nuclear reactions in an assembly of exploding clusters. The laser intensity and the cluster size dependence of the dynamics and energetics of CE of (D(2))(n), (HT)(n), (CD(4))(n), (DI)(n), (CD(3)I)(n), and (CH(3)I)(n) clusters were explored by electrostatic models and molecular dynamics simulations, quantifying energetic driving effects, and kinematic run-over effects. The optimization of table-top dd nuclear fusion driven by CE of deuterium containing heteroclusters is realized for light-heavy heteroclusters of the largest size, which allows for the prevalence of cluster vertical ionization at the highest intensity of the laser field. We demonstrate a 7-orders-of-magnitude enhancement of the yield of dd nuclear fusion driven by CE of light-heavy heteroclusters as compared with (D(2))(n) clusters of the same size. Prospective applications for the attainment of table-top nucleosynthesis reactions, e.g., (12)C(P,gamma)(13)N driven by CE of (CH(3)I)(n) clusters, were explored.

MIA PaCa-2 and PANC-1 - pancreas ductal adenocarcinoma cell lines with neuroendocrine differentiation and somatostatin receptors.

PubMed

Gradiz, Rui; Silva, Henriqueta C; Carvalho, Lina; Botelho, Maria Filomena; Mota-Pinto, Anabela

2016-02-17

Studies using cell lines should always characterize these cells to ensure that the results are not distorted by unexpected morphological or genetic changes possibly due to culture time or passage number. Thus, the aim of this study was to describe those MIA PaCa-2 and PANC-1 cell line phenotype and genotype characteristics that may play a crucial role in pancreatic cancer therapeutic assays, namely neuroendocrine chemotherapy and peptide receptor radionuclide therapy. Epithelial, mesenchymal, endocrine and stem cell marker characterization was performed by immunohistochemistry and flow cytometry, and genotyping by PCR, gene sequencing and capillary electrophoresis. MIA PaCa-2 (polymorphism) expresses CK5.6, AE1/AE3, E-cadherin, vimentin, chromogranin A, synaptophysin, SSTR2 and NTR1 but not CD56. PANC-1 (pleomorphism) expresses CK5.6, MNF-116, vimentin, chromogranin A, CD56 and SSTR2 but not E-cadherin, synaptophysin or NTR1. MIA PaCA-1 is CD24(-), CD44(+/++), CD326(-/+) and CD133/1(-), while PANC-1 is CD24(-/+), CD44(+), CD326(-/+) and CD133/1(-). Both cell lines have KRAS and TP53 mutations and homozygous deletions including the first 3 exons of CDKN2A/p16(INK4A), but no SMAD4/DPC4 mutations or microsatellite instability. Both have neuroendocrine differentiation and SSTR2 receptors, precisely the features making them suitable for the therapies we propose to assay in future studies.

Submicron-scale mineralogy of lithotypes and the implications for trace element associations: Blue Gem coal, Knox County, Kentucky

DOE PAGES

Hower, James C.; Berti, Debora; Hochella, Michael F.; ...

2018-04-16

Transmission electron microscopy accompanied by energy-dispersive spectroscopy and selected area electron diffraction of density-gradient separates from two lithotypes of the low-ash, low-sulfur Blue Gem coal, eastern Kentucky, revealed an array of previously unrecognized (in this coal, and arguable in most others) sub-micron minerals, some <10 nm in size. The first sample representing the 1.22–1.24 specific gravity fraction of the middle bench contains a mineral identified as a La-, Ce-, Nd-bearing monazite; other minerals with CrFe, CuFeS, FeZn-S, and Pb; and areas, probably comprising agglomerates of several grains, if not several minerals, with concentrations of Mg, Ca, Ti, Fe, Zn, Zr,more » and Mo. The second sample representing the 1.30–1.31 specific gravity fraction of the basal lithotype has aggregates of particles enriched in Mg, Ca, Ti, and Fe. Individual grains not specifically quantified include CrNiMnCuFeS, AgS, and CuS. Detailed investigation of one area (most of the variation within a <4 μm 2 region) demonstrates the presence of greenockite (CdS); minute phases containing NiCoGe and AgCdBi, the latter with a more evident S association than the former; metallic Bi; nisnite (Ni 3Sn); silver cadmium; manganosite (MnO); and siderite. Some minerals, such as the monazite, are most likely of detrital or tuffaceous origin. Many of the other assemblages could be of hydrothermal origin, a hypothesis supported by known regional geochemical and coal rank trends, but not previously demonstrated in mineral assemblages at the 10's of nm scale in this region.« less

Submicron-scale mineralogy of lithotypes and the implications for trace element associations: Blue Gem coal, Knox County, Kentucky

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

Hower, James C.; Berti, Debora; Hochella, Michael F.

Transmission electron microscopy accompanied by energy-dispersive spectroscopy and selected area electron diffraction of density-gradient separates from two lithotypes of the low-ash, low-sulfur Blue Gem coal, eastern Kentucky, revealed an array of previously unrecognized (in this coal, and arguable in most others) sub-micron minerals, some <10 nm in size. The first sample representing the 1.22–1.24 specific gravity fraction of the middle bench contains a mineral identified as a La-, Ce-, Nd-bearing monazite; other minerals with CrFe, CuFeS, FeZn-S, and Pb; and areas, probably comprising agglomerates of several grains, if not several minerals, with concentrations of Mg, Ca, Ti, Fe, Zn, Zr,more » and Mo. The second sample representing the 1.30–1.31 specific gravity fraction of the basal lithotype has aggregates of particles enriched in Mg, Ca, Ti, and Fe. Individual grains not specifically quantified include CrNiMnCuFeS, AgS, and CuS. Detailed investigation of one area (most of the variation within a <4 μm 2 region) demonstrates the presence of greenockite (CdS); minute phases containing NiCoGe and AgCdBi, the latter with a more evident S association than the former; metallic Bi; nisnite (Ni 3Sn); silver cadmium; manganosite (MnO); and siderite. Some minerals, such as the monazite, are most likely of detrital or tuffaceous origin. Many of the other assemblages could be of hydrothermal origin, a hypothesis supported by known regional geochemical and coal rank trends, but not previously demonstrated in mineral assemblages at the 10's of nm scale in this region.« 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

Calcium-calmodulin-dependent protein kinase mediates the intracellular signalling pathways of cardiac apoptosis in mice with impaired glucose tolerance.

PubMed

Federico, Marilen; Portiansky, Enrique L; Sommese, Leandro; Alvarado, Francisco J; Blanco, Paula G; Zanuzzi, Carolina N; Dedman, John; Kaetzel, Marcia; Wehrens, Xander H T; Mattiazzi, Alicia; Palomeque, Julieta

2017-06-15

Spontaneous sarcoplasmic reticulum (SR) Ca 2+ release events increased in fructose-rich diet mouse (FRD) myocytes vs. control diet (CD) mice, in the absence of significant changes in SR Ca 2+ load. In HEK293 cells, hyperglycaemia significantly enhanced [ 3 H]ryanodine binding and Ca 2+ /calmodulin-dependent protein kinase II (CaMKII) phosphorylation of RyR2-S2814 residue vs. normoglycaemia. These increases were prevented by CaMKII inhibition. FRD significantly augmented cardiac apoptosis in WT vs. CD-WT mice, which was prevented by co-treatment with the reactive oxygen species scavenger Tempol. Oxidative stress was also increased in FRD-SR-autocamide inhibitory peptide (AIP) mice, expressing the SR-targeted CaMKII inhibitor AIP, without any significant enhancement of apoptosis vs. CD-SR-AIP mice. FRD produced mitochondrial swelling and membrane depolarization in FRD-WT mice but not in FRD-S2814A mice, in which the CaMKII site on ryanodine receptor 2 was ablated. FRD decreased mitochondrial area, mean Feret diameter and the mean distance between SR and the outer mitochondrial membrane vs. CD hearts. This remodelling was prevented in AC3I mice, with cardiac-targeted CaMKII inhibition. The impact of cardiac apoptosis in pre-diabetic stages of diabetic cardiomyopathy is unknown. We show that myocytes from fructose-rich diet (FRD) animals exhibit arrhythmias produced by exacerbated Ca 2+ /calmodulin-protein kinase (CaMKII) activity, ryanodine receptor 2 (RyR2) phosphorylation and sarcoplasmic reticulum (SR) Ca 2+ leak. We tested the hypothesis that this mechanism also underlies cardiac apoptosis in pre-diabetes. We generated a pre-diabetic model in FRD mice. FRD mice showed an increase in oxidative stress, hypertrophy and systolic dysfunction. FRD myocytes exhibited enhanced SR Ca 2+ spontaneous events in the absence of SR Ca 2+ load alterations vs. control-diet (CD) myocytes. In HEK293 cells, hyperglycaemia significantly enhanced [ 3 H]ryanodine binding and CaMKII phosphorylation of RyR2-S2814 residue vs. normoglycaemia. CaMKII inhibition prevented hyperglycaemia-induced alterations. FRD also evoked cardiac apoptosis in WT mice vs. CD-WT mice. Co-treatment with the reactive oxygen species scavenger Tempol prevented FRD-induced apoptosis in WT mice. In contrast, FRD enhanced oxidative stress but not apoptosis in FRD-SR-AIP mice, in which a CaMKII inhibitor is targeted to the SR. FRD produced mitochondrial membrane depolarization in WT mice but not in S2814A mice, in which the CaMKII phosphorylation site on RyR2 was ablated. Furthermore, FRD decreased mitochondrial area, mean Feret diameter and mean SR-mitochondrial distance vs. CD-WT hearts. This remodelling was prevented in AC3I mice, with cardiac-targeted CaMKII inhibition. CaMKII phosphorylation of RyR2, SR Ca 2+ leak and mitochondrial membrane depolarization are critically involved in the apoptotic pathway of the pre-diabetic heart. The FRD-induced decrease in SR-mitochondrial distance is likely to additionally favour Ca 2+ transit between the two organelles. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Harnessing the bio-mineralization ability of urease producing Serratia marcescens and Enterobacter cloacae EMB19 for remediation of heavy metal cadmium (II).

PubMed

Bhattacharya, Amrik; Naik, S N; Khare, S K

2018-06-01

In the present study, urease positive Serratia marcescens (NCIM2919) and Enterobacter cloacae EMB19 (MTCC10649) were individually evaluated for remediation of cadmium (II) using ureolysis-induced calcium carbonate precipitation. Both the cultures were observed to efficiently remove cadmium from the media through co-precipitation of Cd (II) and Ca (II). S. marcescens and E. cloacae EMB19, respectively showed 96 and 98% removal of initial 5.0 mg L -1 soluble Cd (II) from the urea and CaCl 2 laden media at 96 h of incubation period. At higher Cd (II) concentrations of 10 and 15 mg L -1 , cadmium removal efficiency was much higher in case of E. cloacae EMB19 compared to S. marcescens. In-vitro cadmium (II) remediation study using urease containing cell-free culture supernatant of S. marcescens and E. cloacae EMB19 showed respective 98 and 53% removal of initial 50 mg L -1  Cd (II) from the reaction mixtures in co-presence of Ca (II). While in sole presence of Cd (II), only 16 and 8% removal of Cd (II) were detected for S. marcescens and E. cloacae EMB19, respectively. The elemental analysis of the co-precipitated mineral products using Energy Dispersive X-ray spectroscopy (EDX) clearly showed the prevalence of Ca and Cd ions. The morphology Cd-Ca composites formed with respect to both the cultures were observed to be of different shape and size as revealed through Scanning Electron Microscopy (SEM). Entire study hence comes out with a sustainable bioremediation option which could be effectively used to tackle Cd (II) or other heavy metal pollution. Copyright © 2018 Elsevier Ltd. All rights reserved.

Superconductivity at different T{sub c} in CdBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub y}

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

Balchev, N.; Lovchinov, V.; Gattef, E.

1995-06-01

A Cd analogue of the Tl and Hg n=3 series with nominal composition CdBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} has been synthesized. The samples were superconducting according to magnetic susceptibility measurements. The critical temperature was 103 or 107 K depending on the preparation conditions. The EDX analysis revealed the presence of Cd-1111, Cd-1121, and Cd-2333 as minor phases. The observed diamagnetic effects were attributed to the different T{sub c} of these phases.

Determination of Cd2+ in aqueous solution using polyindole-Ce(IV) vanadophosphate conductive nanocomposite ion-selective membrane electrode

NASA Astrophysics Data System (ADS)

Khan, Asif Ali; Quasim Khan, Mohd; Hussain, Rizwan

2017-09-01

In the present study an organic-inorganic nanocomposite ion exchanger Polyindole-Ce(IV) vanadophosphate (PIn-CVP) was synthesized via sol-gel process showing excellent ion exchange capacity (IEC‒1.90 meqg-1). The material was characterized by SEM, TEM, XRD, FTIR, and TGA. A heterogeneous ion exchange membrane of PIn-CVP (IEC‒0.90 meqg-1) was also prepared by solution casting method. PIn-CVP shows high electrical conductivity (5.5  ×  10-2 S cm-1) and it is stable up to 120 °C under ambient conditions. Cd2+ selective membrane electrode was fabricated and its linear working range (3.98  ×  10-7 M to 1.0  ×  10-1 M), response time (25 s), Nerstian slope 25.00 mV dec-1 and working pH range (4-7) were calculated. It was employed as an indicator electrode in the potentiometric titration of Cd2+.

Development and validation of a scoring index to predict the presence of lesions in capsule endoscopy in patients with suspected Crohn's disease of the small bowel: a Spanish multicenter study.

PubMed

Egea-Valenzuela, Juan; González Suárez, Begoña; Sierra Bernal, Cristian; Juanmartiñena Fernández, José Francisco; Luján-Sanchís, Marisol; San Juan Acosta, Mileidis; Martínez Andrés, Blanca; Pons Beltrán, Vicente; Sastre Lozano, Violeta; Carretero Ribón, Cristina; de Vera Almenar, Félix; Sánchez Cuenca, Joaquín; Alberca de Las Parras, Fernando; Rodríguez de Miguel, Cristina; Valle Muñoz, Julio; Férnandez-Urién Sainz, Ignacio; Torres González, Carolina; Borque Barrera, Pilar; Pérez-Cuadrado Robles, Enrique; Alonso Lázaro, Noelia; Martínez García, Pilar; Prieto de Frías, César; Carballo Álvarez, Fernando

2018-05-01

Capsule endoscopy (CE) is the first-line investigation in cases of suspected Crohn's disease (CD) of the small bowel, but the factors associated with a higher diagnostic yield remain unclear. Our aim is to develop and validate a scoring index to assess the risk of the patients in this setting on the basis of biomarkers. Data on fecal calprotectin, C-reactive protein, and other biomarkers from a population of 124 patients with suspected CD of the small bowel studied by CE and included in a PhD study were used to build a scoring index. This was first used on this population (internal validation process) and after that on a different set of patients from a multicenter study (external validation process). An index was designed in which every biomarker is assigned a score. Three risk groups have been established (low, intermediate, and high). In the internal validation analysis (124 individuals), patients had a 10, 46.5, and 81% probability of showing inflammatory lesions in CE in the low-risk, intermediate-risk, and high-risk groups, respectively. In the external validation analysis, including 410 patients from 12 Spanish hospitals, this probability was 15.8, 49.7, and 80.6% for the low-risk, intermediate-risk, and high-risk groups, respectively. Results from the internal validation process show that the scoring index is coherent, and results from the external validation process confirm its reliability. This index can be a useful tool for selecting patients before CE studies in cases of suspected CD of the small bowel.

Wound healing potential of a dimeric InlB variant analyzed by in vitro experiments on re-epithelialization of human skin models.

PubMed

Kolditz, F; Krausze, J; Heinz, D W; Niemann, H H; Müller-Goymann, C C

2014-02-01

A constitutively dimeric truncated variant of internalin B (InlB321-CD), acting as stimulator of the receptor tyrosine kinase MET, was tested for dermal wound-healing potential. Due to a lack of the endogenous MET agonist HGF/SF in chronic wounds, HGF/SF substitution by an InlB321-CD-loaded hydrogel might be beneficial in chronic wound therapy. In this study, InlB321-CD in solution and incorporated in a hydrogel was tested for mitogenic effects on immortalized human dermal keratinocytes (HaCaT) with an MTT assay. Cell migration was investigated with a scratch assay on primary keratinocytes (PHK) and on HaCaT. For the latter, scratching needed to be mitomycin C-controlled. InlB321-CD effects on a model of human skin were analyzed histologically with respect to viability. InlB321-CD led to dose-dependent proliferative effects on HaCaT cells whereas the equimolar dose of monomeric InlB321 did not. Upon hydrogel incorporation of InlB321-CD its mitogenic activity for HaCaT cells was maintained thus confirming the hydrogel as a promising drug delivery system. Motogenic effects were shown on both HaCaT and PHK cells. InlB321-CD neither possesses cytotoxic effects on the viability of a human skin model nor alters its organotypic cell morphology. Copyright © 2013 Elsevier B.V. All rights reserved.

Combined use of chiral ionic liquid surfactants and neutral cyclodextrins: evaluation of ionic liquid head groups for enantioseparation of neutral compounds in capillary electrophoresis.

PubMed

Liu, Yijin; Shamsi, Shahab A

2014-09-19

Cyclodextrins (CDs) are most commonly used chiral selectors in capillary electrophoresis (CE). Although the use of neutral CDs and its derivatives have shown to resolve plethora of charged enantiomers, they cannot resolve neutral enantiomers. The use of ionic liquids (ILs) surfactants forming successful complex with CDs present itself an opportunity to resolve neutral enantiomers. In this work, the effect of IL head groups and their complexation ability with heptakis (2,3,6-tri-O-methyl)-β-cyclodextrin (TM-β-CD) was studied for the separation of neutral enantiomers by CE. First, cationic IL type surfactants with different chiral head groups were synthesized. Physicochemical properties such as critical micelle concentration were determined by surface tension, whereas aggregation and polarity were determined by fluorescence spectroscopy. The complexation ability of ILs with TM-β-CD was characterized in the gas phase by CE-mass spectrometry. The influence of the type of ILs head group and its concentration on chiral resolution, resolution per unit time and selectivity were investigated for four structurally diverse neutral compounds. The binding constants of the neutral analytes to the IL-CD complex were estimated by y-reciprocal method. The hydrophobicity of the side chain of the IL head group displayed significant effect on the binding constants and enantioseparations. Copyright © 2014 Elsevier B.V. All rights reserved.

Chemical Analysis of a Carbon-enhanced Very Metal-poor Star: CD-27 14351

NASA Astrophysics Data System (ADS)

Karinkuzhi, Drisya; Goswami, Aruna; Masseron, Thomas

2017-01-01

We present, for the first time, an abundance analysis of a very metal-poor carbon-enhanced star CD-27 14351 based on a high-resolution (R ˜ 48,000) FEROS spectrum. Our abundance analysis performed using local thermodynamic equilibrium model atmospheres shows that the object is a cool star with stellar atmospheric parameters, effective temperature Teff = 4335 K, surface gravity log g = 0.5, microturbulence ξ = 2.42 km s-1, and metallicity [Fe/H] = -2.6. The star exhibits high carbon and nitrogen abundances with [C/Fe] = 2.89 and [N/Fe] = 1.89. Overabundances of neutron-capture elements are evident in Ba, La, Ce, and Nd, with estimated [X/Fe] > 1, the largest enhancement being seen in Ce with [Ce/Fe] = 2.63. While the first peak s-process elements Sr and Y are found to be enhanced with respect to Fe, ([Sr/Fe] = 1.73 and [Y/Fe] = 1.91), the third peak s-process element Pb could not be detected in our spectrum at the given resolution. Europium, primarily an r-process element also shows an enhancement with [Eu/Fe] = 1.65. With [Ba/Eu] = 0.12, the object CD-27 14351 satisfies the classification criterion for a CEMP-r/s star. The elemental abundance distributions observed in this star are discussed in light of the chemical abundances observed in other CEMP stars in the literature.

Folic acid-targeted magnetic Tb-doped CeF3 fluorescent nanoparticles as bimodal probes for cellular fluorescence and magnetic resonance imaging.

PubMed

Ma, Zhi-Ya; Liu, Yu-Ping; Bai, Ling-Yu; An, Jie; Zhang, Lin; Xuan, Yang; Zhang, Xiao-Shuai; Zhao, Yuan-Di

2015-10-07

Magnetic fluorescent nanoparticles (NPs) have great potential applications for diagnostics, imaging and therapy. We developed a facile polyol method to synthesize multifunctional Fe3O4@CeF3:Tb@CeF3 NPs with small size (<20 nm), high water solubility and good biocompatibility. The NPs were modified by ligand exchange reactions with citric acid (CA) to obtain carboxyl-functionalized NPs (Fe3O4@CeF3:Tb@CeF3-COOH). Folic acid (FA) as an affinity ligand was then covalently conjugated onto NPs to yield Fe3O4@CeF3:Tb@CeF3-FA NPs. They were then applied as multimodal imaging agents for simultaneous in vitro targeted fluorescence imaging and magnetic resonance imaging (MRI) of HeLa cells with overexpressed folate receptors (FR). The results indicated that these NPs had strong luminescence and enhanced T2-weighted MR contrast and would be promising candidates as multimodal probes for both fluorescence and MRI imaging.

Characterization of cadmium transport in hepatopancreatic cells of a mangrove crab Ucides cordatus: The role of calcium.

PubMed

Ortega, Priscila; Custódio, Marcio R; Zanotto, Flavia P

2017-07-01

Cadmium is a toxic metal, present in batteries and discarded in estuaries and mangrove habitats. Apart from that, it is a non-essential metal that causes toxic effects in many organisms. Cadmium accumulates in gills and hepatopancreas of crustaceans and its route into the cell is unknown. It is possible that occurs by calcium channels or calcium transporters. The objective of this study was to characterize the transport of cadmium and the role of calcium in different cell types from hepatopancreas of the mangrove crab Ucides cordatus. For this, the hepatopancreas was dissociated by magnetic stirring and after that separated by a sucrose gradient. Then, the cells were labeled with FluoZin-3 AM and different CdCl 2 concentrations were added together with a variety of inhibitors. The results showed that Cd 2+ transport occurs differently in each cell type from hepatopancreas and is partially explained by the function the cells perform in this organ. Embryonic (E) and Resorptive (R) cells transported more Cd 2+ compared to Fibrillar (F) and Blister (B) cells. R cells responded to Ca 2+ channel inhibitors and intracellular Ca 2+ manipulations positively, as the other cell types and in a stronger way. B cells were the least responsive to Ca 2+ channel inhibitors and, unlike the other cells, showed a competition of Cd 2+ with intracellular Ca 2+ manipulations. The results indicate that Ca 2+ affects the transport of Cd 2+ in hepatopancreatic cells of Ucides cordatus and uses Ca 2+ channels to enter these cells. In addition, information about Ca concentration could be used as a mitigating factor for Cd accumulation in crabs' hepatopancreas. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhanced heavy metal immobilization in soil by grinding with addition of nanometallic Ca/CaO dispersion mixture.

PubMed

Mallampati, Srinivasa Reddy; Mitoma, Yoshiharu; Okuda, Tetsuji; Sakita, Shogo; Kakeda, Mitsunori

2012-10-01

This study investigated the use of a nanometallic Ca and CaO dispersion mixture for the immobilization of heavy metals (As, Cd, Cr and Pb) in contaminated soil. Simple grinding achieved 85-90% heavy metal immobilization, but it can be enhanced further to 98-100% by addition of a nanometallic Ca/CaO dispersion mixture produced by grinding. Observations using SEM-EDS elemental maps and semi-quantitative analysis showed that the amounts of As, Cd, Cr, and Pb measurable on the soil particle surface decrease after nanometallic Ca/CaO treatment. The leachable heavy metal concentrations were reduced after nanometallic Ca/CaO treatment to concentrations lower than the Japan soil elution standard regulatory threshold: <0.01 mg L(-1) for As, Cd, and Pb; and 0.05 mg L(-1) for Cr. Effects of soil moisture and pH on heavy metal immobilization were not strongly influenced. The most probable mechanisms for the enhancement of heavy metal immobilization capacity with nanometallic Ca/CaO treatment might be due to adsorption and entrapment of heavy metals into newly formed aggregates, thereby prompting aggregation of soil particles and enclosure/binding with Ca/CaO-associated immobile salts. Results suggest that the nanometallic Ca/CaO mixture is suitable for use in immobilization of heavy-metal-contaminated soil under normal moisture conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Loparite, a rare-earth ore (Ce, Na, Sr, Ca)(Ti, Nb, Ta, Fe+3)O3

USGS Publications Warehouse

Hedrick, James B.; Sinha, Shyama P.; Kosynkin, Valery D.

1997-01-01

The mineral loparite (Ce, NA, Sr, Ca)(Ti, Nb, Ta, Fe+3)O3 is the principal ore of the light-group rare-earth elements (LREE) in Russia. The complex oxide has a perovskite (ABO3) structure with coupled substitutions, polymorphism, defect chemistry and a tendency to become metamict. The A site generally contains weakly bonded, easily exchanged cations of the LREE, Na and Ca. The B site generally contains smaller, highly charged cations of Ti, Nb or Fe+3. Mine production is from Russia's Kola Peninsula. Ore is beneficiated to produce a 95% loparite concentrate containing 30% rare-earth oxides. Loparite concentrate is refined by either a chlorination process or acid decomposition process to recover rare-earths, titanium, niobium and tantalum. Rare-earths are separated by solvent extraction and selective precipitation/dissolution. The concentrate is processed at plants in Russia, Estonia and Kazakstan.

Transparent perovskite light-emitting diodes by employing organic-inorganic multilayer transparent top electrodes

NASA Astrophysics Data System (ADS)

Liang, Junqing; Guo, Xiaoyang; Song, Li; Lin, Jie; Hu, Yongsheng; Zhang, Nan; Liu, Xingyuan

2017-11-01

Perovskite light-emitting diodes (PeLEDs) have attracted much attention in the past two years due to their high photoluminescence quantum efficiencies and wavelength tuneable characteristics. In this work, transparent PeLEDs (TPeLEDs) have been reported with organic-inorganic multilayer transparent top electrodes that have more convenient control of the organic/electrode interface. By optimizing the thickness of the MoO3 layer in the top electrode, the best average transmittance of 47.21% has been obtained in the TPeLED in the wavelength range of 380-780 nm. In addition, the TPeLED exhibits a maximum luminance of 6380 cd/m2, a maximum current efficiency (CE) of 3.50 cd/A, and a maximum external quantum efficiency (EQE) of 0.85% from the bottom side together with a maximum luminance of 3380 cd/m2, a maximum CE of 1.47 cd/A, and a maximum EQE of 0.36% from the top side. The total EQE of the TPeLED is about 86% of that of the reference device, indicating efficient TPeLED achieved in this work, which could have significant contribution to PeLEDs for see-through displays.

CAX1 suppresses Cd-induced generation of reactive oxygen species in Arabidopsis halleri.

PubMed

Ahmadi, Hassan; Corso, Massimiliano; Weber, Michael; Verbruggen, Nathalie; Clemens, Stephan

2018-06-07

The molecular analysis of metal hyperaccumulation in species such as Arabidopsis halleri offers the chance to gain insights into metal homeostasis and into the evolution of adaptation to extreme habitats. A prerequisite of metal hyperaccumulation is metal hypertolerance. Genetic analysis of a backcross population derived from A. lyrata x A. halleri crosses revealed three quantitative trait loci (QTLs) for Cd hypertolerance. A candidate gene for Cdtol2 is AhCAX1, encoding a vacuolar Ca 2+ /H + antiporter. We developed a method for the transformation of vegetatively propagated A. halleri plants and generated AhCAX1-silenced lines. Upon Cd 2+ exposure several-fold higher accumulation of reactive oxygen species (ROS) was detectable in roots of AhCAX1-silenced plants. In accordance with the dependence of Cdtol2 on external Ca 2+ concentration, this phenotype was exclusively observed in low Ca 2+ conditions. The effects of external Ca 2+ on Cd accumulation cannot explain the phenotype as they were not influenced by the genotype. Our data strongly support the hypothesis that higher expression of CAX1 in A. halleri relative to other Arabidopsis species represents a Cd hypertolerance factor. We propose a function of AhCAX1 in preventing a positive feedback loop of Cd-elicited ROS production triggering further Ca 2+ -dependent ROS accumulation. This article is protected by copyright. All rights reserved.

Photoluminescence, energy transfer and tunable color of Ce(3+), Tb(3+) and Eu(2+) activated oxynitride phosphors with high brightness.

PubMed

Lü, Wei; Huo, Jiansheng; Feng, Yang; Zhao, Shuang; You, Hongpeng

2016-06-21

New tuneable light-emitting Ca3Al8Si4O17N4:Ce(3+)/Tb(3+)/Eu(2+) oxynitride phosphors with high brightness have been prepared. When doped with trivalent cerium or divalent europium they present blue luminescence under UV excitation. The energy transfer from Ce(3+) to Tb(3+) and Ce(3+) to Eu(2+) ions is deduced from the spectral overlap between Ce(3+) emission and Tb(3+)/Eu(2+) excitation spectra. The energy-transfer efficiencies and corresponding mechanisms are discussed in detail, and the mechanisms of energy transfer from the Ce(3+) to Tb(3+) and Ce(3+) to Eu(2+) ions are demonstrated to be a dipole-quadrupole and dipole-dipole mechanism, respectively, by the Inokuti-Hirayama model. The International Commission on Illumination value of color tuneable emission as well as luminescence quantum yield (23.8-80.6%) can be tuned by controlling the content of Ce(3+), Tb(3+) and Eu(2+). All results suggest that they are suitable for UV light-emitting diode excitation.

Borrelidins C-E: New Antibacterial Macrolides from a Saltern-Derived Halophilic Nocardiopsis sp.

PubMed

Kim, Jungwoo; Shin, Daniel; Kim, Seong-Hwan; Park, Wanki; Shin, Yoonho; Kim, Won Kyung; Lee, Sang Kook; Oh, Ki-Bong; Shin, Jongheon; Oh, Dong-Chan

2017-06-06

Chemical investigation of a halophilic actinomycete strain belonging to the genus Nocardiopsis inhabiting a hypersaline saltern led to the discovery of new 18-membered macrolides with nitrile functionality, borrelidins C-E ( 1 - 3 ), along with a previously reported borrelidin ( 4 ). The planar structures of borrelidins C-E, which are new members of the rare borrelidin class of antibiotics, were elucidated by NMR, mass, IR, and UV spectroscopic analyses. The configurations of borrelidines C-E were determined by the interpretation of ROESY NMR spectra, J-based configuration analysis, a modified Mosher's method, and CD spectroscopic analysis. Borrelidins C and D displayed inhibitory activity, particularly against the Gram-negative pathogen Salmonella enterica , and moderate cytotoxicity against the SNU638 and K562 carcinoma cell lines.

Chemical data and statistical interpretations for rocks and ores from the Ranger uranium mine, Northern Territory, Australia

USGS Publications Warehouse

Nash, J. Thomas; Frishman, David

1983-01-01

Analytical results for 61 elements in 370 samples from the Ranger Mine area are reported. Most of the rocks come from drill core in the Ranger No. 1 and Ranger No. 3 deposits, but 20 samples are from unmineralized drill core more than 1 km from ore. Statistical tests show that the elements Mg, Fe, F, Be, Co, Li, Ni, Pb, Sc, Th, Ti, V, CI, As, Br, Au, Ce, Dy, La Sc, Eu, Tb, Yb, and Tb have positive association with uranium, and Si, Ca, Na, K, Sr, Ba, Ce, and Cs have negative association. For most lithologic subsets Mg, Fe, Li, Cr, Ni, Pb, V, Y, Sm, Sc, Eu, and Yb are significantly enriched in ore-bearing rocks, whereas Ca, Na, K, Sr, Ba, Mn, Ce, and Cs are significantly depleted. These results are consistent with petrographic observations on altered rocks. Lithogeochemistry can aid exploration, but for these rocks requires methods that are expensive and not amenable to routine use.

[LincRNA-ROR functions as a ceRNA to regulate Oct4, Sox2, and Nanog expression by sponging miR-145 and its effect on biologic characteristics of colonic cancer stem cells].

PubMed

Yan, Z Y; Sun, X C

2018-04-08

Objective: To investigate the impact of lincRNA-ROR, a ceRNA by binding miR-145 on the expression of the downstream genes Oct4, Sox2 and Nanog, and related biological characteristics of colon cancer stem cells, and to elucidate the clinical significance of this molecular regulatory network. Methods: Fifty-two cases of colorectal cancer tissue and adjacent tissue were collected at Nanyang City Central Hospital and Nanyang Second Hospital, Henan Province, from 2014 to 2016. Real-time quantitative polymerase chain reaction (qPCR) was used to detect the expression of lincRNA-ROR and miR-145 in colorectal cancer tissue and isolated colon cancer cells. The correlation between the expression of lincRNA-ROR, miR-145 and the clinicopathologic features of colon cancer was performed. CD44(-)CD133(-) and CD44(+) CD133(+) cells were isolated from SW1116 by using flow cytometry. The expression of CD44, CD133, Oct4, Sox2, Nanog, lincRNA-ROR and miR-145 in cells were detected by qPCR. The relationship between lincRNA-ROR, miR-145, Oct4, Sox2 and Nanog was analyzed by bioinformatics, dual luciferase reporter assay, qPCR and Western blot. The effects of silencing lincRNA-ROR on the proliferation and chemosensitivity of colon cancer stem cells were detected by MTT, colony formation. Results: LincRNA-ROR was frequently up-regulated and inversely correlated with miR-145 down-regulation in the colon cancer specimens( P <0.05). LincRNA-ROR was related to tumor size, lymph node involvement and distant metastasis( P <0.05), and miR-145 was found related to tumor size and tumor location( P <0.05). CD44(+) CD133(+) cells were successfully isolated from SW1116 by flow cytometry. The levels of CD44, CD133, Oct4, Sox2, Nanog, lincRNA-ROR in CD44(+) CD133(+) cells were significantly increased, while miR-145 was decreased compared with CD44(-)CD133(-)cells( P <0.05). The levels of CD44, CD133, lnc-ROR in CD44(+) CD133(+) cells were significantly reduced upon cell adherence, while miR-145 was significantly increased( P <0.05). Bioinformatics analysis revealed that lincRNA-ROR shared miRNA response elements with core transcription factors Oct4, Sox2 and Nanog. MiR-145 significantly inhibited the expression of lincRNA-ROR, Oct4, Sox2 and Nanog. Silencing lincRNA-ROR significantly inhibited colon cancer stem cells proliferation and increased the sensitivity to chemotherapy. Conclusions: Linc-ROR functions as a key ceRNA to prevent core TFs, e. g., Oct4, Sox2, Nanog, from miR-145-mediated suppression in colon cancer stem cells and regulates cell proliferation and chemosensitivity.The data may provide insights into the pathophysiological interactions of the components of genetic networks in the development of colon cancer and may lead to new therapies in the future.

LED-CE-DOAS measurements of NO2: intercomparison with CaRDS

NASA Astrophysics Data System (ADS)

Thalman, R. M.; Washenfelder, R.; Brown, S. S.; Volkamer, R.

2009-04-01

The combination of cavity enhanced absorption spectroscopy (CEAS) with Light Emitting Diode (LED) light sources lends itself to the application of the well established Differential Optical Absorption Spectroscopy (DOAS) technique (LED-CE-DOAS). In contrast to other broad band CEAS (BB-CEAS) techniques, CE-DOAS relies only on the measurement of relative intensity changes, i.e., does not require knowledge of the light intensity in the absence of trace gases (I0). With CE-DOAS there is no necessity for sampling lines to supply air samples into a cavity, or filters to remove aerosols from the airstream, as measurements are possible in a cavity that can be open to the atmosphere. A novel LED-CE-DOAS instrument was built at CU Boulder for the sensitive and selective detection of nitrogen dioxide (NO2), glyoxal (CHOCHO), iodine oxide (IO), water, and oxygen dimers (O4). CU Boulder's LED-CE-DOAS instrument was collocated to NOAA's NO2 Cavity Ring Down (CaRDS) instrument to test different CE-DOAS data retrieval algorithms for NO2 and O4. Both instruments were collocated to sample known NO2 concentrations from the same gas manifold, and to sample atmospheric air in a parking lot. This contribution focuses on the instrument components, challenges and means to retrieve quantitative concentrations of NO2 by LED-CE-DOAS, i.e., the distortion of NO2 and O4 absorption features due to different effective path lengths induced by (1) changes in the mirror reflectivity with wavelength, and (2) changes in light extinction across the absorption bands due to differential trace gas absorption features. We demonstrate that simultaneous measurements of O4 and NO2 enable to characterize the effective pathlength in the absence and presence of NO2 and perform absolute measurements based only on relative intensity measurements. To our knowledge these are the first CEAS measurements that rely solely on relative intensity measurements.

Underlying mechanism of the contractile dysfunction in atrophied ventricular myocytes from a murine model of hypothyroidism.

PubMed

Montalvo, Dolores; Pérez-Treviño, Perla; Madrazo-Aguirre, Katheryne; González-Mondellini, Fabio A; Miranda-Roblero, Hipólito O; Ramonfaur-Gracia, Diego; Jacobo-Antonio, Mariana; Mayorga-Luna, Maritza; Gómez-Víquez, Norma L; García, Noemí; Altamirano, Julio

2018-06-01

Hypothyroidism (Hypo) is a risk factor for cardiovascular diseases, including heart failure. Hypo rapidly induces Ca 2+ mishandling and contractile dysfunction (CD), as well as atrophy and ventricular myocytes (VM) remodeling. Hypo decreases SERCA-to-phospholamban ratio (SERCA/PLB), and thereby contributes to CD. Nevertheless, detailed spatial and temporal Ca 2+ cycling characterization in VM is missing, and contribution of other structural and functional changes to the mechanism underlying Ca 2+ mishandling and CD, as transverse tubules (T-T) remodeling, mitochondrial density (D mit ) and energy availability, is unclear. Therefore, in a rat model of Hypo, we aimed to characterize systolic and diastolic Ca 2+ signaling, T-T remodeling, D mit , citrate synthase (CS) activity and high-energy phosphate metabolites (ATP and phosphocreatine). We confirmed a decrease in SERCA/PLB (59%), which slowed SERCA activity (48%), reduced SR Ca 2+ (19%) and blunted Ca 2+ transient amplitude (41%). Moreover, assessing the rate of SR Ca 2+ release (dRel/dt), we found that early and maximum dRel/dt decreased, and this correlated with staggered Ca 2+ transients. However, dRel/dt persisted during Ca 2+ transient relaxation due to abundant late Ca 2+ sparks. Isoproterenol significantly up-regulated systolic Ca 2+ cycling. T-T were unchanged, hence, cannot explain staggered Ca 2+ transients and altered dRel/dt. Therefore, we suggest that these might be caused by RyR2 clusters desynchronization, due to diminished Ca 2+ -dependent sensitivity of RyR2, which also caused a decrease in diastolic SR Ca 2+ leak. Furthermore, D mit was unchanged and CS activity slightly decreased (14%), however, the ratio phosphocreatine/ATP did not change, therefore, energy deficiency cannot account for Ca 2+ and contractility dysregulation. We conclude that decreased SR Ca 2+ , due to slower SERCA, disrupts systolic RyR2 synchronization, and this underlies CD. Copyright © 2018 Elsevier Ltd. All rights reserved.

Hyperforin/HP-β-Cyclodextrin Enhances Mechanosensitive Ca2+ Signaling in HaCaT Keratinocytes and in Atopic Skin Ex Vivo Which Accelerates Wound Healing.

PubMed

Takada, Hiroya; Yonekawa, Jun; Matsumoto, Masami; Furuya, Kishio; Sokabe, Masahiro

2017-01-01

Cutaneous wound healing is accelerated by mechanical stretching, and treatment with hyperforin, a major component of a traditional herbal medicine and a known TRPC6 activator, further enhances the acceleration. We recently revealed that this was due to the enhancement of ATP-Ca 2+ signaling in keratinocytes by hyperforin treatment. However, the low aqueous solubility and easy photodegradation impede the topical application of hyperforin for therapeutic purposes. We designed a compound hydroxypropyl- β -cyclodextrin- (HP- β -CD-) tetracapped hyperforin, which had increased aqueous solubility and improved photoprotection. We assessed the physiological effects of hyperforin/HP- β -CD on wound healing in HaCaT keratinocytes using live imaging to observe the ATP release and the intracellular Ca 2+ increase. In response to stretching (20%), ATP was released only from the foremost cells at the wound edge; it then diffused to the cells behind the wound edge and activated the P2Y receptors, which caused propagating Ca 2+ waves via TRPC6. This process might facilitate wound closure, because the Ca 2+ response and wound healing were inhibited in parallel by various inhibitors of ATP-Ca 2+ signaling. We also applied hyperforin/HP- β -CD on an ex vivo skin model of atopic dermatitis and found that hyperforin/HP- β -CD treatment for 24 h improved the stretch-induced Ca 2+ responses and oscillations which failed in atopic skin.

Hyperforin/HP-β-Cyclodextrin Enhances Mechanosensitive Ca2+ Signaling in HaCaT Keratinocytes and in Atopic Skin Ex Vivo Which Accelerates Wound Healing

PubMed Central

Takada, Hiroya; Yonekawa, Jun; Matsumoto, Masami; Sokabe, Masahiro

2017-01-01

Cutaneous wound healing is accelerated by mechanical stretching, and treatment with hyperforin, a major component of a traditional herbal medicine and a known TRPC6 activator, further enhances the acceleration. We recently revealed that this was due to the enhancement of ATP-Ca2+ signaling in keratinocytes by hyperforin treatment. However, the low aqueous solubility and easy photodegradation impede the topical application of hyperforin for therapeutic purposes. We designed a compound hydroxypropyl-β-cyclodextrin- (HP-β-CD-) tetracapped hyperforin, which had increased aqueous solubility and improved photoprotection. We assessed the physiological effects of hyperforin/HP-β-CD on wound healing in HaCaT keratinocytes using live imaging to observe the ATP release and the intracellular Ca2+ increase. In response to stretching (20%), ATP was released only from the foremost cells at the wound edge; it then diffused to the cells behind the wound edge and activated the P2Y receptors, which caused propagating Ca2+ waves via TRPC6. This process might facilitate wound closure, because the Ca2+ response and wound healing were inhibited in parallel by various inhibitors of ATP-Ca2+ signaling. We also applied hyperforin/HP-β-CD on an ex vivo skin model of atopic dermatitis and found that hyperforin/HP-β-CD treatment for 24 h improved the stretch-induced Ca2+ responses and oscillations which failed in atopic skin. PMID:28210627

Colossal magnetoresistance accompanied with magnetorelaxor behavior in phase-separated Ca1-xCexMnO3 thin films and CaMnO3/Ca0.92Ce0.08MnO3 superlattices

NASA Astrophysics Data System (ADS)

Xiang, P.-H.; Yamada, H.; Sawa, A.; Akoh, H.

2010-03-01

We report on the transport properties of electron-doped manganite Ca1-xCexMnO3 (CCMO, 0≤x≤0.08) films and superlattices composed of insulating layers CaMnO3 (CMO) and Ca0.92Ce0.08MnO3 (CCMO8), deposited on nearly lattice-matched NdAlO3 substrates. The CCMO (x =0.06 and 0.07) films show colossal magnetoresistance (CMR) accompanied with magnetorelaxor behavior, which can be ascribed to the phase separation of canted G-type antiferromagnetic metal and C-type antiferromagnetic insulator. The (CMO)m/(CCMO8)n superlattices with 4≤m, n ≤8 (unit cells) resemble the solid-solution CCMO (x =0.06 and 0.07) films in CMR and magnetorelaxor behavior, suggesting that the phase separation takes place in the superlattices. The CMR and magnetorelaxor behavior of the (CMO)m/(CCMO8)n superlattices strongly depend on the thicknesses of constituent CMO and CCMO8 layers. The origin of the phase separation in the superlattices is discussed in terms of the charge transfer and the phase competition at the interfaces.

A-Site (MCe) Substitution Effects on the Structures and Properties of CaBi4Ti4O15 Ceramics

NASA Astrophysics Data System (ADS)

Yan, Haixue; Li, Chengen; Zhou, Jiaguang; Zhu, Weimin; He, Lianxin; Song, Yuxin

2000-11-01

We investigated the effect of A-site compound substitution on the structures and properties of Ca0.8(MCe)0.1Bi4Ti4O15 (M denotes Li, Na and K) ceramics. The samples were prepared by the conventional ceramic technique. Sintering characteristics of Ca0.8(MCe)0.1Bi4Ti4O15 and CaBi4Ti4O15 ceramics were discussed. X-ray powder diffraction patterns of the three modified CBT-based compounds show a single phase of bismuth oxide layer type structure with m=4. The hysteresis loops of polarization versus electric field of the four compounds were also measured. A-site compound substitution improves the piezoelectric properties and the high-temperature resistivity of these materials. A-site (LiCe) and (KCe) substitution not only improves the Curie temperature but also decreases the temperature coefficient of dielectric constant (TK\\varepsilon). Among the three modified ceramics, only the Curie temperature of Ca0.8(NaCe)0.1Bi4Ti4O15 is lower than that of CaBi4Ti4O15; however, its TK\\varepsilon is the lowest. As a result, all the three modified CBT-based ceramics were found to be excellent high-temperature piezoelectric materials.

Effect of ca+2 addition on the properties of ce0.8gd0.2o2-δ for it-sofc

NASA Astrophysics Data System (ADS)

Koteswararao, P.; Buchi Suresh, M.; Wani, B. N.; Bhaskara Rao, P. V.; Varalaxmi, P.

2018-03-01

This paper reports the effect of Ca2+ addition on the structural and electrical properties of Ce0.8Gd0.2O2-δ(GDC) electrolyte for low temperature solid oxide fuel cell application. The Ca (0, 0.5, 1 and 2 mol %) doped GDC solid electrolytes have been prepared by solid state method. The sintered densities of the samples are greater than 95%. XRD study reveals the cubic fluorite structure. The microstructure of the samples sintered at 1400°C resulted into grain sizes in the range of 1.72 to 10.20 μm. Raman spectra show the presence of GDC single phase. AC impedance analysis is used to measure the ionic conductivity of the electrolyte. Among all the compositions, the highest conductivity is observed in the GDC sample with 0.5 mol% Ca addition. Nyquist plots resulted in multiple redoxation process such as grain and grain boundary conductions to final conductivity. Estimated blocking factor is lower for the GDC electrolyte with 0.5mol% Ca, indicating that Ca addition was promoted grain boundary conduction. Activation energies were calculated from Arrhenius plot and are found in the range of 1eV.

Ceria-Based Anodes for Next Generation Solid Oxide Fuel Cells

NASA Astrophysics Data System (ADS)

Mirfakhraei, Behzad

Mixed ionic and electronic conducting materials (MIECs) have been suggested to represent the next generation of solid oxide fuel cell (SOFC) anodes, primarily due to their significantly enhanced active surface area and their tolerance to fuel components. In this thesis, the main focus has been on determining and tuning the physicochemical and electrochemical properties of ceria-based MIECs in the versatile perovskite or fluorite crystal structures. In one direction, BaZr0.1Ce0.7Y0.1 M0.1O3-delta (M = Fe, Ni, Co and Yb) (BZCY-M) perovskites were synthesized using solid-state or wet citric acid combustion methods and the effect of various transition metal dopants on the sintering behavior, crystal structure, chemical stability under CO2 and H 2S, and electrical conductivity, was investigated. BZCY-Ni, synthesized using the wet combustion method, was the best performing anode, giving a polarization resistance (RP) of 0.4 O.cm2 at 800 °C. Scanning electron microscopy and X-ray diffraction analysis showed that this was due to the exsolution of catalytic Ni nanoparticles onto the oxide surface. Evolving from this promising result, the effect of Mo-doped CeO 2 (nCMO) or Ni nanoparticle infiltration into a porous Gd-doped CeO 2 (GDC) anode (in the fluorite structure) was studied. While 3 wt. % Ni infiltration lowered RP by up to 90 %, giving 0.09 O.cm2 at 800 °C and exhibiting a ca. 5 times higher tolerance towards 10 ppm H2, nCMO infiltration enhanced the H2 stability by ca. 3 times, but had no influence on RP. In parallel work, a first-time study of the Ce3+ and Ce 4+ redox process (pseudocapacitance) within GDC anode materials was carried out using cyclic voltammetry (CV) in wet H2 at high temperatures. It was concluded that, at 500-600 °C, the Ce3+/Ce 4+ reaction is diffusion controlled, probably due to O2- transport limitations in the outer 5-10 layers of the GDC particles, giving a very high capacitance of ca. 70 F/g. Increasing the temperature ultimately diminished the observed capacitance, likely as the chemical reduction of GDC at high temperatures is irreversible.

An experimental study of the behaviour of cerium/molybdenum ratios during subduction: Implications for tracing the slab component in the Lesser Antilles and Mariana Arc

NASA Astrophysics Data System (ADS)

Skora, Susanne; Freymuth, Heye; Blundy, Jon; Elliott, Tim; Guillong, Marcel

2017-09-01

Arc magmas are very distinct in their geochemical signatures, a consequence of trace element enriched components from the subducting slab that are incorporated into melts of the overlying mantle wedge. However, it is not always straightforward to distinguish such slab components from assimilation of crustal rocks during subsequent differentiation, given that both reservoirs can share similar geochemical characteristics. This has prompted the development of new tools, such as 98Mo/95Mo analyses used in combination with Ce/Mo measurements. The diverse range of δ98/95Mo in the surface environment gives rise to variable isotopic compositions of subducted Mo. Most diagnostic of these is the extremely isotopically heavy Mo in marine black shales, such as those drilled in the vicinity of the Lesser Antilles. However, subducting assemblages are invariably complex and differing melting behaviours and contrasting δ98/95Mo of various crustal components may counter-balance one another, requiring a more detailed investigation of the behaviour of Mo and Ce in the down-going slab. This study is dedicated to identifying possible hosts for Mo and Ce in sediments and basalt at sub-arc depths. New melting experiments were performed (3 GPa, 800-900 °C), using synthetic carbon-rich black shale and calcareous sediment compositions from the Lesser Antilles arc. In addition, new analyses of Mo concentrations and Ce/Mo data of previously published partial melting studies on altered oceanic crust and volcaniclastics (Mariana Arc) are presented. Our study suggests that sulfide and to a lesser extent rutile are the major hosts for Mo in eclogites, whereas the presence or absence of monazite (Ca-poor sediments), epidote (Ca-rich sediments) and carbonate (CaCO3-rich sediments) controls Ce concentrations in sediments. Redox conditions are found to be of great importance for the Ce/Mo ratios of slab components derived from these lithologies because of their influence on sulfide and epidote stability. It is further shown that rutile only hosts Mo at suitably reducing conditions, in concordance with previous studies. The combination of measured Ce/Mo with our experimental results thus places important constrains on phase petrology and redox conditions in the subducted slab.

Characteristics of cadmium uptake and membrane transport in roots of intact wheat (Triticum aestivum L.) seedlings.

PubMed

Li, Lian-Zhen; Tu, Chen; Peijnenburg, Willie J G M; Luo, Yong-Ming

2017-02-01

Wheat is one of several cereals that is capable of accumulating higher amounts of Cd in plant tissues. It is important to understand the Cd 2+ transport processes in roots that result in excess Cd accumulation. Traditional destructive technologies have limited capabilities in analyzing root samples due to methodological limitations, and sometimes may result in false conclusions. The mechanisms of Cd 2+ uptake into the roots of wheat seedlings (Triticum aestivum L.) were investigated by assessing the impact of various inhibitors and channel blockers on Cd accumulation as well as the real-time net Cd 2+ flux at roots with the non-destructive scanning ion-selective electrode technique. The P-type ATPase inhibitor Na 3 VO 4 (500 μM) had little effect on Cd uptake (p < 0.05) and the kinetics of transport in the root of wheat, suggesting that Cd 2+ uptake into wheat root cells is not directly dependent on H + gradients. While, the uncoupler 2,4-dinitrophenol significantly limited Cd 2+ uptake (p < 0.05) and transport kinetics in the root of wheat, suggesting the existence of metabolic mediation in the Cd 2+ uptake process by wheat. The Cd content at the whole-plant level in wheat was significantly (p < 0.05) decreased upon pretreatment with the Ca 2+ channel blockers La 3+ or Gd 3+ and Verapamil, but not in case of pretreatment with the K + channel blocker tetraethylammonium (TEA). In addition, the inhibitors of the Ca 2+ channel, as well as high concentrations of Ca 2+ , reduced the real-time net Cd 2+ fluxes at the root surface in SIET experiments. These results indicate that Cd 2+ moves across the plasma lemma of the wheat root via Ca 2+ channels. In addition, our results suggested a role for protein synthesis in mediating Cd 2+ uptake and transport by wheat. Copyright © 2016. Published by Elsevier Ltd.

Mercury, cadmium and arsenic contents of calcium dietary supplements.

PubMed

Kim, Meehye

2004-08-01

The cadmium (Cd) and arsenic (As) contents of calcium (Ca) supplements available on the Korean market were determined by a graphite furnace atomic absorption spectrometer using Zeeman background correction and peak area mode after microwave digestion. The mercury (Hg) content of the supplements was measured using an Hg analyser. Recoveries ranged from 92 to 98% for Hg, Cd and As analyses. Fifty-five brands of Ca supplements were classified into seven categories based on the major composite: bone, milk, oyster/clam shell, egg shell, algae, shark cartilage and chelated. The means of Hg, Cd and As in Ca supplements were 0.01, 0.02, and 0.48 mg kg(-1), respectively. Ca supplements made of shark cartilage had the highest means of Hg (0.06 mg kg(-1)) and Cd (0.13 mg kg(-1)). The mean daily intakes of Hg and Cd from the supplement were estimated as about 0.1-0.2 microg, with both contributing less than 0.4% of provisional tolerable daily intakes set by the Food and Agricultural Organization/World Health Organization Joint Food Additive and Contaminants Committee.

Protective Effects of Calcium on Cadmium Accumulation in Co-Cultured Silver Carp (Hypophthalmichthys molitrix) and Triangle Sail Mussel (Hyriopsis cumingii).

PubMed

Li, Deliang; Pi, Jie; Wang, Jianping; Zhu, Pengfei; Lei, Liuping; Zhang, Ting; Liu, Deming

2016-12-01

Discovering cost effective strategies to reduce cadmium (Cd) uptake is of great concern for consumer food safety in the aquaculture industry. This study investigated the protective effects of calcium (Ca) on Cd uptake in co-cultured silver carp (Hypophthalmichthys molitrix) and triangle sail mussel (Hyriopsis cumingii). The results show that Ca-depending on its applied concentration-caused a significant decrease in the Cd uptake into muscle (by 48 %-72 %), gills (by 51 %-57 %), liver (by 52 %-81 %) and kidney (by 54 %-81 %) of silver carp (p < 0.001), as well as foot (by 8 %-32 %) and visceral mass (by 40 %-47 %) of triangle sail mussels (p < 0.05). The results indicate that Ca treatment is an effective means of reducing Cd accumulation in aquaculture. Since Ca is often used to increase the quality of pearls produced by triangle sail mussel, the quality of co-cultured edible fish might improve as a consequence of the potentially reduced Cd uptake.

The association between three promoter polymorphisms of IL-10 and inflammatory bowel diseases (IBD): a meta-analysis.

PubMed

Zou, Liwei; Wang, Longsheng; Gong, Xijun; Zhao, Hong; Jiang, Anhong; Zheng, Suisheng

2014-02-01

To assess the relationship of the Interleukin-10 (IL-10) -1082G/A (rs1800896), -819C/T (rs1800871) and -592C/A (rs1800872) polymorphism with inflammatory bowel disease (IBD) by means of meta-analysis. Published data addressing the association between polymorphism of the IL-10 with Crohn's disease (CD) and Ulcerative colitis (UC) were selected from electronic databases. A total of 17 studies including 4132 cases and 5109 controls were included in this meta-analysis which detected whether -1082G/A, -819C/T and -592C/A polymorphism were associated with CD or UC susceptibility. The IL-10 -819C/T and -519C/A variant allele observed a significant association with UC (OR 1.16, 95%CI 1.03-1.31 and OR 1.19, 95%CI 1.03-1.38) not CD while there is no significant association between -1082G/A and UC or CD. The IL-10 -819C/T and -592C/A polymorphisms contribute to susceptibility to UC, but IL-10 -1082G/A polymorphism neither associated with CD nor UC.

Improved thermoelectric performance of n-type Ca and Ca-Ce filled skutterudites

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

Thompson, Daniel R.; Liu, Chang; Ellison, Nicole D.

2014-12-28

Thermoelectric (TE) technology for use in automotive waste heat recovery is being advanced by General Motors with support from the US Department of Energy. Skutterudites are a very promising material for this application of TE technology due to their superior mechanical properties and good TE performance. Double-filled Yb{sub x}Ba{sub y}Co{sub 4}Sb{sub 12} with ZT values around 1.1 at 750 K are the best performing n-type skutterudites produced on a large scale using an economically viable approach of melt spinning (MS) in conjunction with spark plasma sintering (SPS). Another economical production method on the tons scale, the melt quench annealing (MQA) technique,more » has been recently claimed by Treibacher Industrie AG, further information is available [G. Rogl et al., Acta Mater. 76, 434–448 (2014)]. A possible hurdle to commercial implementation of these materials is the use of rare earths as the fillers to reduce thermal conductivity and improve the electrical transport properties. It will be shown herein that skutterudites double-filled with Ca and Ce, both of which are lower-cost fillers, display markedly different TE properties depending on whether they are produced by MQA or MS + SPS synthesis techniques. Ca and Ce double-filled skutterudites prepared by MS + SPS have TE properties that are superior to the same compositions prepared by MQA and that are comparable to the best performing Yb and Ba filled materials. Furthermore, the results of this study suggest that the unusually poor transport properties of MQA Ca-filled skutterudites can be ascribed to deleterious secondary phases, which is contrary to reports in the literature attempting to explain these irregularities via band structure features.« less

Improved thermoelectric performance of n-type Ca and Ca-Ce filled skutterudites

DOE PAGES

Thompson, Daniel R.; Liu, Chang; Ellison, Nicole D.; ...

2014-12-28

Thermoelectric (TE) technology for use in automotive waste heat recovery is being advanced by General Motors with support from the US Department of Energy. Skutterudites are a very promising material for this application of TE technology due to their superior mechanical properties and good TE performance. Double-filled Yb xBa yCo 4Sb 12 with ZT values around 1.1 at 750K are the best performing n-type skutterudites produced on a large scale using an economically viable approach of melt spinning (MS) in conjunction with spark plasma sintering (SPS). Another economical production method on the tons scale, the melt quench annealing (MQA) technique,more » has been recently claimed by Treibacher Industrie AG, further information is available [G. Rogl et al., Acta Mater. 76, 434-448 (2014)]. A possible hurdle to commercial implementation of these materials is the use of rare earths as the fillers to reduce thermal conductivity and improve the electrical transport properties. It will be shown herein that skutterudites double-filled with Ca and Ce, both of which are lower-cost fillers, display markedly different TE properties depending on whether they are produced by MQA or MS + SPS synthesis techniques. Finally, Ca and Ce double-filled skutterudites prepared by MS + SPS have TE properties that are superior to the same compositions prepared by MQA and that are comparable to the best performing Yb and Ba filled materials. Furthermore, the results of this study suggest that the unusually poor transport properties of MQA Ca-filled skutterudites can be ascribed to deleterious secondary phases, which is contrary to reports in the literature attempting to explain these irregularities via band structure features.« less

Manganite perovskite ceramics, their precursors and methods for forming

DOEpatents

Payne, David Alan; Clothier, Brent Allen

2015-03-10

Disclosed are a variety of ceramics having the formula Ln.sub.1-xM.sub.xMnO.sub.3, where 0.Itoreq.x.Itoreq.1 and where Ln is La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or Y; M is Ca, Sr, Ba, Cd, or Pb; manganite precursors for preparing the ceramics; a method for preparing the precursors; and a method for transforming the precursors into uniform, defect-free ceramics having magnetoresistance properties. The manganite precursors contain a sol and are derived from the metal alkoxides: Ln(OR).sub.3, M(OR).sub.2 and Mn(OR).sub.2, where R is C.sub.2 to C.sub.6 alkyl or C.sub.3 to C.sub.9 alkoxyalkyl, or C.sub.6 to C.sub.9 aryl. The preferred ceramics are films prepared by a spin coating method and are particularly suited for incorporation into a device such as an integrated circuit device.

Investigation of DOTA-Metal Chelation Effects on the Chemical Shift of 129 Xe

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

Jeong, Keunhong; Slack, Clancy C.; Vassiliou, Christophoros C.

2015-09-17

Recent work has shown that xenon chemical shifts in cryptophane-cage sensors are affected when tethered chelators bind to metals. Here in this paper, we explore the xenon shifts in response to a wide range of metal ions binding to diastereomeric forms of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) linked to cryptophane-A. The shifts induced by the binding of Ca 2+, Cu 2+, Ce 3+, Zn 2+, Cd 2+, Ni 2+, Co 2+, Cr 2+, Fe 3+, and Hg 2+ are distinct. In addition, the different responses of the diastereomers for the same metal ion indicate that shifts are affected by partial folding withmore » a correlation between the expected coordination number of the metal in the DOTA complex and the chemical shift of 129Xe. Lastly, these sensors may be used to detect and quantify many important metal ions, and a better understanding of the basis for the induced shifts could enhance future designs.« less

Multielement analysis of Canadian wines by inductively coupled plasma mass spectrometry (ICP-MS) and multivariate statistics.

PubMed

Taylor, Vivien F; Longerich, Henry P; Greenough, John D

2003-02-12

Trace element fingerprints were deciphered for wines from Canada's two major wine-producing regions, the Okanagan Valley and the Niagara Peninsula, for the purpose of examining differences in wine element composition with region of origin and identifying elements important to determining provenance. Analysis by ICP-MS allowed simultaneous determination of 34 trace elements in wine (Li, Be, Mg, Al, P, Cl, Ca, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Mo, Ag, Cd, Sb, I, Cs, Ba, La, Ce, Tl, Pb, Bi, Th, and U) at low levels of detection, and patterns in trace element concentrations were deciphered by multivariate statistical analysis. The two regions were discriminated with 100% accuracy using 10 of these elements. Differences in soil chemistry between the Niagara and Okanagan vineyards were evident, without a good correlation between soil and wine composition. The element Sr was found to be a good indicator of provenance and has been reported in fingerprinting studies of other regions.

Identification and integrated analysis of differentially expressed lncRNAs and circRNAs reveal the potential ceRNA networks during PDLSC osteogenic differentiation.

PubMed

Gu, Xiuge; Li, Mengying; Jin, Ye; Liu, Dongxu; Wei, Fulan

2017-12-02

Researchers have been exploring the molecular mechanisms underlying the control of periodontal ligament stem cell (PDLSC) osteogenic differentiation. Recently, long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) were shown to function as competitive endogenous RNAs (ceRNAs) to regulate the effect of microRNAs (miRNAs) on their target genes during cell differentiation. However, comprehensive identification and integrated analysis of lncRNAs and circRNAs acting as ceRNAs during PDLSC osteogenic differentiation have not been performed. PDLSCs were derived from healthy human periodontal ligament and cultured separately with osteogenic induction and normal media for 7 days. Cultured PDLSCs were positive for STRO-1 and CD146 and negative for CD31 and CD45. Osteo-induced PDLSCs showed increased ALP (alkaline phosphatase) activity and up-regulated expression levels of the osteogenesis-related markers ALP, Runt-related transcription factor 2 and osteocalcin. Then, a total of 960 lncRNAs and 1456 circRNAs were found to be differentially expressed by RNA sequencing. The expression profiles of eight lncRNAs and eight circRNAs were measured with quantitative real-time polymerase chain reaction and were shown to agree with the RNA-seq results. Furthermore, the potential functions of lncRNAs and circRNAs as ceRNAs were predicted based on miRanda and were investigated using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis. In total, 147 lncRNAs and 1382 circRNAs were predicted to combine with 148 common miRNAs and compete for miRNA binding sites with 744 messenger RNAs. These mRNAs were predicted to significantly participate in osteoblast differentiation, the MAPK pathway, the Wnt pathway and the signaling pathways regulating pluripotency of stem cells. Among them, lncRNAs coded as TCONS_00212979 and TCONS_00212984, as well as circRNA BANP and circRNA ITCH, might interact with miRNA34a and miRNA146a to regulate PDLSC osteogenic differentiation via the MAPK pathway. This study comprehensively identified lncRNAs/circRNAs and first integrated their potential ceRNA function during PDLSC osteogenic differentiation. These findings suggest that specific lncRNAs and circRNAs might function as ceRNAs to promote PDLSC osteogenic differentiation and periodontal regeneration.

Differential blockade of agonist- and depolarization-induced sup 45 Ca2+ influx in smooth muscle cells

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

Wallnoefer, A.C.; Cauvin, C.; Lategan, T.W.

1989-10-01

ATP stimulated {sup 45}Ca2+ influx in rat aortic smooth muscle cells in a concentration-dependent manner (EC50 = 3.6 +/- 0.5 X 10(-7) M). ADP and GTP were less effective than ATP in stimulating {sup 45}Ca2+ influx; AMP was weakly active and the adenosine agonist 5'-(N-ethyl-carboxamido)-adenosine (NECA) had no effect. ATP gamma S was about equieffective with ATP, whereas alpha,beta-methylene-ATP (APCPP) did not induce {sup 45}Ca2+ influx. Stimulation of {sup 45}Ca2+ influx by ATP was not abolished by the dihydropyridine Ca2+ channel antagonist darodipine (PY 108-068), which completely blocked depolarization-induced {sup 45}Ca2+ influx. Inorganic cations (La3+, Cd2+, Co2+, Ni2+, Mn2+, andmore » Mg2+) were able to inhibit both agonist- and depolarization-induced {sup 45}Ca2+ influx. Cd2+, however, was approximately 20 times more selective in blocking K+-stimulated than agonist-stimulated {sup 45}Ca2+ influx. These data indicate that ATP-stimulated Ca2+ influx in rat aortic smooth muscle cells is resistant to darodipine but is reduced by La3+, Cd2+, and other inorganic blockers of Ca2+ channels.« less

Development of a Highly Efficient Hybrid White Organic-Light-Emitting Diode with a Single Emission Layer by Solution Processing.

PubMed

Wu, Jun-Yi; Chen, Show-An

2018-02-07

We use a mixed host, 2,6-bis[3-(carbazol-9-yl)phenyl]pyridine blended with 20 wt % tris(4-carbazoyl-9-ylphenyl)amine, to lower the hole-injection barrier, along with the bipolar and high-photoluminescence-quantum-yield (Φ p = 84%), blue thermally activated delay fluorescence (TADF) material of 9,9-dimethyl-9,10-dihydroacridine-2,4,6-triphenyl-1,3,5-triazine (DMAC-TRZ) as a blue dopant to compose the emission layer for the fabrication of a TADF blue organic-light-emitting diode (BOLED). The device is highly efficient with the following performance parameters: maximum brightness (B max ) = 57586 cd/m 2 , maximum current efficiency (CE max ) = 35.3 cd/A, maximum power efficiency (PE max ) = 21.4 lm/W, maximum external quantum efficiency (EQE max ) = 14.1%, and CIE coordinates (0.18, 0.42). This device has the best performance recorded among the reported solution-processed TADF BOLEDs and has a low efficiency roll-off: at brightness values of 1000 and 5000 cd/m 2 , its CEs are close, being 35.1 and 30.1 cd/A, respectively. Upon further doping of the red phosphor Ir(dpm)PQ 2 (emission peak λ max = 595 nm) into the blue emission layer, we obtained a TADF-phosphor hybrid white organic-light-emitting diode (T-P hybrid WOLED) with high performance: B max = 43594 cd/m 2 , CE max = 28.8 cd/A, PE max = 18.1 lm/W, and CIE coordinates (0.38, 0.44). This B max = 43594 cd/m 2 is better than that of the vacuum-deposited WOLED with a blue TADF emitter, 10000 cd/m 2 . This is also the first report on a T-P hybrid WOLED with a solution-processed emitting layer.

Earth's partial pressure of CO2 over the past 100-500 Ma; evidence from Ce anomalies in mostly shallow seas (less than 200 m) as recorded in carbonate sediments, 2

NASA Technical Reports Server (NTRS)

Liu, Y.-G.; Reinhardt, J. W.; Schmitt, R. A.

1993-01-01

We reported the direct relationship of Ce anomalies recorded in 0.2-119 Ma CaCO3 sediments (Ce(sup A*)) to the Ce anomalies in the parental Pacific deep seawater (Ce(sup A)) and their relationship to atmospheric P(CO2) relative to present P(CO2). We have analyzed continental CaCO3 samples that were deposited in ancient oceans and shallow sea platforms less than 200 m over central USA, central Europe, China, and Saudi-Arabia/Oman. We have plotted Ce(sup A*) over the 75-470 Ma interval. For P(CO2) calculations, we assumed as a reference standard the less than 200 m mixed Pacific Ocean with a Ce(sup A) geometric mean of 0.22 and a range of 0.10-0.43. Because P(CO2) values obtained from reliable deep Pacific Ocean carbonates in the 67-119 Ma interval were similar to the present P(CO2) values, we have drawn a 1.0 ratio for that interval. Although there is considerable scatter among the approximately 150 Ma carbonates, the average Ce(sup A*) value suggests that P(CO2) increased during the early Cretaceous, from 1.0X at approximately 120 Ma to about 1.4X at approximately 150 Ma. At approximately 250 Ma, the average Ce(sup A*) in 13 shallow sea China carbonates agrees well with the single and more reliable approximately 250 Ma China carbonate deposited in deeper open platform. We suggest that P(CO2) ranged from 1.4-1.7X over the Jurassic and Triassic periods. At approximately 280 Ma, three China carbonates deposited in deeper open platforms and therefore considered more reliable are consistent with a European carbonate, which indicate Ce(sup A) and P(CO2) values similar to the present. The minimum at this time corresponds to the great Permo-Carboniferous glaciation. From 280 Ma to 470 Ma, the trend favors increasing Ce(sup A*) and corresponding P(CO2) values between 1.9-2.7X, with a more reliable value closer to 2.7X at 430 Ma because of the unknown higher temperature in the less than 100 m seawater over continental USA which was located just south of the equator at approximately 430 Ma.

Effects of habitual chitosan intake on bone mass, bone-related metabolic markers and duodenum CaBP D9K mRNA in ovariectomized SHRSP rats.

PubMed

Yang, Chu-Ya; Oh, Tae-Woong; Nakajima, Daito; Maeda, Atsuko; Naka, Tatsuki; Kim, Chang-Sun; Igawa, Shoji; Ohta, Fukio

2002-10-01

We have demonstrated that the habitual intake of chitosan can decrease bone mass in ovariectomized (OVX) SHRSP rats fed a low-Ca diet (0.1%). In the present study, we examined both the etiology of bone loss induced by dietary chitosan and the preventive effect of vitamin C supplementation. Rats were OVX and maintained on one of the following diets for 6 wk: 10% cellulose (CE). 10% chitosan (CH) or 10% chitosan with sodium ascorbate (CHVC). CH caused a significant reduction in bone mineral density (BMD) and stiffness in femurs and the fourth lumbar vertebrae (L4). There was no significant difference in intestinal Ca absorption between CH and CE, whereas CH intake significantly reduced intestinal P absorption. The bone loss in CH rats was accompanied with an increase in urinary Ca excretion and a decrease in serum Ca as well as a significant increment In serum PTH and 1,25(OH)2D3. The vitamin D receptor and calcium binding protein D9K mRNAs were also significantly increased in the duodenum of CH rats. Vitamin C supplementation to CH caused an increase in the Ca and P contents of femurs as well as BMD of the L4, with a decrease in urinary Ca excretion. These results indicate that dietary chitosan with low Ca intake possibly induces the loss of bone mass by enhancing urinary Ca excretion rather than by inhibiting Ca absorption, and that vitamin C supplementation could prevent bone loss caused by chitosan through the increment of retained Ca followed by suppression of urinary Ca excretion.

Recent advances in CD8+ regulatory T cell research

PubMed Central

Yu, Yating; Ma, Xinbo; Gong, Rufei; Zhu, Jianmeng; Wei, Lihua; Yao, Jinguang

2018-01-01

Various subgroups of CD8+ T lymphocytes do not only demonstrate cytotoxic effects, but also serve important regulatory roles in the body's immune response. In particular, CD8+ regulatory T cells (CD8+ Tregs), which possess important immunosuppressive functions, are able to effectively block the overreacting immune response and maintain the body's immune homeostasis. In recent years, studies have identified a small set of special CD8+ Tregs that can recognize major histocompatibility complex class Ib molecules, more specifically Qa-1 in mice and HLA-E in humans, and target the self-reactive CD4+ T ce lls. These findings have generated broad implications in the scientific community and attracted general interest to CD8+ Tregs. The present study reviews the recent research progress on CD8+ Tregs, including their origin, functional classification, molecular markers and underlying mechanisms of action.

Effects of soil properties on the transfer of cadmium from soil to wheat in the Yangtze River delta region, China--a typical industry-agriculture transition area.

PubMed

Wang, Cheng; Ji, Junfeng; Yang, Zhongfang; Chen, Lingxiao; Browne, Patrick; Yu, Ruilian

2012-08-01

In order to identify the effects of soil properties on the transfer of Cd from soil to wheat under actual field conditions, 126 pairs of topsoil and wheat samples were collected from the Yangtze River delta region, China. Relevant parameters (Cd, Ca, Mg, Fe, Mn, Zn, N, P, K, S, pH, total organic carbon, and speciation of soil Cd) in soil and wheat tissues were analyzed, and the results were treated by statistical methods. Soil samples (19.8%) and 14.3% of the wheat grain samples exceeded the relevant maximum permissible Cd concentrations in China for agricultural soil and wheat grain, respectively. The major speciations of Cd in soil were exchangeable, bound to carbonates and fulvic and humic acid fraction, and they were readily affected by soil pH, total Ca, Mg, S and P, DTPA-Fe, Ex-Ca, and Ex-Mg. Cadmium showed a strong correlation with Fe, S, and P present in the grain and the soil, whereas there was no significant correlation in the straw or root. Generally, soil pH, Ca, Mg, Mn, P, and slowly available K restricted Cd transfer from soil to wheat, whereas soil S, N, Zn, DTPA-Fe, and total organic carbon enhance Cd uptake by wheat.

Concentration addition and independent action model: Which is better in predicting the toxicity for metal mixtures on zebrafish larvae.

PubMed

Gao, Yongfei; Feng, Jianfeng; Kang, Lili; Xu, Xin; Zhu, Lin

2018-01-01

The joint toxicity of chemical mixtures has emerged as a popular topic, particularly on the additive and potential synergistic actions of environmental mixtures. We investigated the 24h toxicity of Cu-Zn, Cu-Cd, and Cu-Pb and 96h toxicity of Cd-Pb binary mixtures on the survival of zebrafish larvae. Joint toxicity was predicted and compared using the concentration addition (CA) and independent action (IA) models with different assumptions in the toxic action mode in toxicodynamic processes through single and binary metal mixture tests. Results showed that the CA and IA models presented varying predictive abilities for different metal combinations. For the Cu-Cd and Cd-Pb mixtures, the CA model simulated the observed survival rates better than the IA model. By contrast, the IA model simulated the observed survival rates better than the CA model for the Cu-Zn and Cu-Pb mixtures. These findings revealed that the toxic action mode may depend on the combinations and concentrations of tested metal mixtures. Statistical analysis of the antagonistic or synergistic interactions indicated that synergistic interactions were observed for the Cu-Cd and Cu-Pb mixtures, non-interactions were observed for the Cd-Pb mixtures, and slight antagonistic interactions for the Cu-Zn mixtures. These results illustrated that the CA and IA models are consistent in specifying the interaction patterns of binary metal mixtures. Copyright © 2017 Elsevier B.V. All rights reserved.

Involvement of dominant-negative spliced variants of the intermediate conductance Ca2+-activated K+ channel, K(Ca)3.1, in immune function of lymphoid cells.

PubMed

Ohya, Susumu; Niwa, Satomi; Yanagi, Ayano; Fukuyo, Yuka; Yamamura, Hisao; Imaizumi, Yuji

2011-05-13

The intermediate conductance Ca(2+)-activated K(+) channel (IK(Ca) channel) encoded by K(Ca)3.1 is responsible for the control of proliferation and differentiation in various types of cells. We identified novel spliced variants of K(Ca)3.1 (human (h) K(Ca)3.1b) from the human thymus, which were lacking the N-terminal domains of the original hK(Ca)3.1a as a result of alternative splicing events. hK(Ca)3.1b was significantly expressed in human lymphoid tissues. Western blot analysis showed that hK(Ca)3.1a proteins were mainly expressed in the plasma membrane fraction, whereas hK(Ca)3.1b was in the cytoplasmic fraction. We also identified a similar N terminus lacking K(Ca)3.1 variants from mice and rat lymphoid tissues (mK(Ca)3.1b and rK(Ca)3.1b). In the HEK293 heterologous expression system, the cellular distribution of cyan fluorescent protein-tagged hK(Ca)3.1a and/or YFP-tagged hK(Ca)3.1b isoforms showed that hK(Ca)3.1b suppressed the localization of hK(Ca)3.1a to the plasma membrane. In the Xenopus oocyte translation system, co-expression of hK(Ca)3.1b with hK(Ca)3.1a suppressed IK(Ca) channel activity of hK(Ca)3.1a in a dominant-negative manner. In addition, this study indicated that up-regulation of mK(Ca)3.1b in mouse thymocytes differentiated CD4(+)CD8(+) phenotype thymocytes into CD4(-)CD8(-) ones and suppressed concanavalin-A-stimulated thymocyte growth by down-regulation of mIL-2 transcripts. Anti-proliferative effects and down-regulation of mIL-2 transcripts were also observed in mK(Ca)3.1b-overexpressing mouse thymocytes. These suggest that the N-terminal domain of K(Ca)3.1 is critical for channel trafficking to the plasma membrane and that the fine-tuning of IK(Ca) channel activity modulated through alternative splicing events may be related to the control in physiological and pathophysiological conditions in T-lymphocytes.

Colloidal stability of CeO2 nanoparticles coated with either natural organic matter or organic polymers under various hydrochemical conditions

NASA Astrophysics Data System (ADS)

Dippon, Urs; Pabst, Silke; Klitzke, Sondra

2016-04-01

The worldwide marked for engineered nanoparticles (ENPs) is growing and concerns on the environmental fate- and toxicity of ENPs are rising. Understanding the transport of ENPs within and between environmental compartments such as surface water and groundwater is crucial for exposition modeling, risk assessment and ultimately the protection of drinking water resources. The transport of ENPs is strongly influenced by the surface properties and aggregation behavior of the particles, which is strongly controlled by synthetic and natural organic coatings. Both, surface properties and aggregation characteristics are also key properties for the industrial application of ENPs, which leads to the development and commercialization of an increasing number of surface-functionalized ENPs. These include metals and oxides such as Cerium dioxide (CeO2) with various organic coatings. Therefore, we investigate CeO2 ENPs with different surface coatings such as weakly anionic polyvinyl alcohol (PVA) or strongly anionic poly acrylic acid (PAA) with respect to their colloidal stability in aqueous matrix under various hydrochemical conditions (pH, ionic strength) and their transport behavior in sand filter columns. Furthermore, we investigate the interaction of naturally occurring organic matter (NOM) with CeO2 ENPs and its effect on surface charge (zeta potential), colloidal stability and transport. While uncoated CeO2 ENPs aggregate at pH > 4 in aqueous matrix, our results show that PAA and PVA surface coatings as well as NOM sorbed to CeO2-NP surfaces can stabilize CeO2 ENPs under neutral and alkaline pH conditions in 1 mM KCl solution. Under slightly acidic conditions, differences between the three particle types were observed. PVA can stabilize particle suspensions in presence of 1 mM KCl at pH > 4.3, PAA at pH >4.0 and NOM at >3.2. While the presence of KCl did not influence particle size of NOM-CeO2 ENPs, CaCl2 at >2 mM lead to aggregation. Further results on the influence of KCl and CaCl2 on aggregation of coated CeO2 ENPs and transport in sand filter columns will be presented.

Apical P2XR contribute to [Ca2+]i signaling and Isc in mouse renal MCD.

PubMed

Li, Liuzhe; Lynch, I Jeanette; Zheng, Wencui; Cash, Melanie N; Teng, Xueling; Wingo, Charles S; Verlander, Jill W; Xia, Shen-Ling

2007-08-03

We examined P2X receptor expression and distribution in the mouse collecting duct (CD) and their functional role in Ca(2+) signaling. Both P2X(1) and P2X(4) were detected by RT-PCR and Western blot. Immunohistochemistry demonstrated apical P2X(1) and P2X(4) immunoreactivity in principal cells in the outer medullary CD (OMCD) and inner medullary CD (IMCD). Luminal ATP induced an increase in Ca(2+) signaling in native medullary CD (MCD) as measured by fluorescence imaging. ATP also induced an increase in Ca(2+) signaling in MCD cells grown in primary culture but not in the presence of P2XR antagonist PPNDS. Short circuit current (I(sc)) measurement with mouse IMCD cells showed that P2XR agonist BzATP induced a larger I(sc) than did P2YR agonist UTP in the apical membrane. Our data reveal for the first time that P2X(1) and P2X(4) are cell-specific with prominent immunoreactivity in the apical area of MCD cells. The finding that P2XR blockade inhibits ATP-induced Ca(2+) signaling suggests that activation of P2XR is a key step in Ca(2+)-dependent purinergic signaling. The result that activation of P2XR produces large I(sc) indicates the necessity of P2XR in renal CD ion transport.

Protective effects of cinnamic acid and cinnamic aldehyde on isoproterenol-induced acute myocardial ischemia in rats.

PubMed

Song, Fan; Li, Hua; Sun, Jiyuan; Wang, Siwang

2013-10-28

Cinnamomum cassia is a well-known traditional Chinese herb that is widely used for the treatment of ischemic heart disease (IHD). It has favorable effects, but its mechanism is not clear. To investigate the effects of cinnamic aldehyde (CA) and cinnamic acid (CD) isolated from Cinnamomum cassia against myocardial ischemia produced in rats by isoproterenol (ISO). Ninety male Sprague-Dawley rats were randomized equally to nine groups: a control group, an untreated model group, CA (22.5, 45, 90 mg/kg) or CD (37.5, 75, 150 mg/kg) treatment, or propranolol (30 mg/kg). Rats were treated for 14 days and then given ISO, 4 mg/kg for 2 consecutive days by subcutaneous injection. ST-segment elevation was measured after the last administration. Serum levels of creatine kinase (CK), lactate dehydrogenase (LDH), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), nitric oxide (NO), and blood rheology were measured after the rats were sacrificed. The hearts were excised for determining heart weight index, microscopic examination, superoxide dismutase (SOD) and malondialdehyde (MDA) measurements. CA and CD decreased the ST elevation induced by acute myocardial ischemia, decreased serum levels of CK-MB, LDH, TNF-α and IL-6, and increased serum NO activity. CA and CD increased SOD activity and decreased MDA content in myocardial tissue. CA and CD were cardioprotective in a rat model of ischemic myocardial injury. The protection was attributable to anti-oxidative and anti-inflammatory properties, as well as increased NO. The results support further study of CA and CD as potential treatments for ischemic heart disease. © 2013 Elsevier Ireland Ltd. All rights reserved.

Impact of demographic and clinical parameters on video capsule transit time.

PubMed

Niv, Eva; Pinchasovich, Hadassa; Yanai, Henit

2016-10-01

Small bowel (SB) capsule endoscopy (CE) studies provide data on both gastric and SB transit times (GTT and SBTT, respectively). This study aimed to evaluate the influence of demographic and clinical parameters on the GTT and SBTT. Transit times for two generations of capsules (Pillcam SB2 and SB3) were also compared. Consecutive adult patients undergoing CE were included. GTT, SBTT, and cecum arrival rates were calculated and correlated to demographics and clinical characteristics. A total of 332 CE studies were analyzed. Neither GTT nor SBTT were impacted by age or sex. SBTT was prolonged in newly diagnosed Crohn's disease (CD) patients compared with all other patients (303.1±90.3 vs. 243.6±83.6 min, P=0.02 for SB2, 267.8±63 vs. 228.6±72.3, P=0.01 for SB3, respectively). Moreover, CD patients had higher incomplete study rates compared with patients with all other diagnoses (29.4 vs. 7.3%, respectively, P=0.0116) in the SB2 subgroup. Higher cecum arrival rates were achieved by the SB3 capsule compared with SB2 (97 vs. 91%, P=0.04). Patients with prolonged gastric time or patients with incomplete studies had similar demographic and clinical characteristics as others. Age and sex apparently do not influence intestinal kinetics. Newly diagnosed CD patients have relatively prolonged SBTTs. Demographic and clinical parameters cannot predict prolonged GTT or cecum nonarrival.

Ca2+ signaling in taste bud cells and spontaneous preference for fat: unresolved roles of CD36 and GPR120.

PubMed

Abdoul-Azize, Souleymane; Selvakumar, Subramaniam; Sadou, Hassimi; Besnard, Philippe; Khan, Naim Akhtar

2014-01-01

Recent compelling evidences from rodent and human studies raise the possibility for an additional sixth taste modality devoted to oro-gustatory perception of dietary lipids. Understanding the mechanisms underlying oro-gustatory detection of dietary fat is critical for the prevention and treatment of obesity. A number of studies have suggested that lingual CD36, a glycoprotein, highly expressed by circumvallate papillae of the tongue, is implicated in the perception of dietary fat taste. G protein-coupled receptors (GPCRs) are important signaling molecules for many aspects of cellular functions. It has been shown that these receptors, particularly GPR120, are also involved in lipid taste perception. We have shown that dietary long-chain fatty acids (LCFAs), in CD36-positive taste bud cells (TBC), induce increases in free intracellular Ca(2+) concentrations, [Ca(2+)]i, by recruiting Ca(2+) from endoplasmic reticulum (ER) pool via inositol 1,4,5-triphosphate production, followed by Ca(2+) influx via opening of store-operated Ca(2+) (SOC) channels. GPR120 is also coupled to increases in [Ca(2+)]i by dietary fatty acids. We observed that stromal interaction molecule 1 (STIM1), a sensor of Ca(2+) depletion in the ER, mediated fatty acid-induced Ca(2+) signaling and spontaneous preference for fat in the mouse. In this review article, we discuss the recent advances and unresolved roles of CD36 and GPR120 in lipid taste signaling in taste bud cells. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

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.

Growth and Cd uptake by rice (Oryza sativa) in acidic and Cd-contaminated paddy soils amended with steel slag.

PubMed

He, Huaidong; Tam, Nora F Y; Yao, Aijun; Qiu, Rongliang; Li, Wai Chin; Ye, Zhihong

2017-12-01

Contamination of rice (Oryza sativa) by Cd is of great concern. Steel slag could be used to amend Cd-contaminated soils and make them safe for cereal production. This work was conducted to study the effects of steel slag on Cd uptake and growth of rice plants in acidic and Cd-contaminated paddy soils and to determine the possible mechanisms behind these effects. Pot (rhizobag) experiments were conducted using rice plants grown on two acidic and Cd-contaminated paddy soils with or without steel slag amendment. Steel slag amendment significantly increased grain yield by 36-45% and root catalase activity, and decreased Cd concentrations in brown rice by 66-77% compared with the control, in both soils. Steel slag amendment also markedly decreased extractable soil Cd, Cd concentrations in pore-water and Cd translocation from roots to above-ground parts. It also significantly increased soil pH, extractable Si and Ca in soils and Ca concentrations in roots. Significant positive correlations were found between extractable soil Cd and Cd concentrations in rice tissues, but it was negatively correlated with soil pH and extractable Si. Calcium in root tissues significantly and negatively correlated with Cd translocation factors from roots to straw. Overall, steel slag amendment not only significantly promoted rice growth but decreased Cd accumulation in brown rice. These benefits appear to be related to improvements in soil conditions (e.g. increasing pH, extractable Si and Ca), a reduction in extractable soil Cd, and suppression of Cd translocation from roots to above-ground parts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Different fecal microbiotas and volatile organic compounds in treated and untreated children with celiac disease.

PubMed

Di Cagno, Raffaella; Rizzello, Carlo G; Gagliardi, Francesca; Ricciuti, Patrizia; Ndagijimana, Maurice; Francavilla, Ruggiero; Guerzoni, M Elisabetta; Crecchio, Carmine; Gobbetti, Marco; De Angelis, Maria

2009-06-01

This study aimed at investigating the fecal microbiotas of children with celiac disease (CD) before (U-CD) and after (T-CD) they were fed a gluten-free diet and of healthy children (HC). Brothers or sisters of T-CD were enrolled as HC. Each group consisted of seven children. PCR-denaturing gradient gel electrophoresis (DGGE) analysis with V3 universal primers revealed a unique profile for each fecal sample. PCR-DGGE analysis with group- or genus-specific 16S rRNA gene primers showed that the Lactobacillus community of U-CD changed significantly, while the diversity of the Lactobacillus community of T-CD was quite comparable to that of HC. Compared to HC, the ratio of cultivable lactic acid bacteria and Bifidobacterium to Bacteroides and enterobacteria was lower in T-CD and even lower in U-CD. The percentages of strains identified as lactobacilli differed as follows: HC (ca. 38%) > T-CD (ca. 17%) > U-CD (ca. 10%). Lactobacillus brevis, Lactobacillus rossiae, and Lactobacillus pentosus were identified only in fecal samples from T-CD and HC. Lactobacillus fermentum, Lactobacillus delbrueckii subsp. bulgaricus, and Lactobacillus gasseri were identified only in several fecal samples from HC. Compared to HC, the composition of Bifidobacterium species of T-CD varied, and it varied even more for U-CD. Forty-seven volatile organic compounds (VOCs) belonging to different chemical classes were identified using gas-chromatography mass spectrometry-solid-phase microextraction analysis. The median concentrations varied markedly for HC, T-CD, and U-CD. Overall, the r(2) values for VOC data for brothers and sisters were equal to or lower than those for unrelated HC and T-CD. This study shows the effect of CD pathology on the fecal microbiotas of children.

Calcium availability but not its content modulates metal toxicity in Scenedesmus quadricauda.

PubMed

Kováčik, Jozef; Dresler, Sławomir

2018-01-01

Impact of calcium nutrition (pre-culture on solid medium with standard or elevated Ca dose, i. e. 0.17 and 4.40mM marked as low and high Ca) on acute metal toxicity (Cd, Mn and Pb, 24h of exposure to 10µM) in freshwater green alga Scenedesmus quadricauda was studied. Surprisingly, Ca content differed only slightly between low and high Ca samples and applied metals rather suppressed its amount. Na content was higher in metal-exposed high Ca samples, indicating that Ca/Na ratio may affect accumulation of metals. Content of heavy metals increased in order Cd < Mn < Pb and high Ca samples contained less metal than low Ca samples at least in absorbed fraction. Accumulation of ascorbic acid and thiols (GSH - glutathione and PC2 - phytochelatin 2) was affected mainly by Cd, GSH also by Mn and PC2 by Pb with often significant differences between low Ca and high Ca samples. Calcium nutrition also affected responses of algae to metals at the level of antioxidative enzyme activities (SOD, APX, and CAT) and elevated values were typically found in high Ca samples while ROS (hydrogen peroxide and superoxide radical) were mainly depleted in Mn treatment. These data confirm that Ca nutrition affects accumulation of metals in algae and metabolic parameters as observed in vascular plants but, unlike them, rather Ca/Na ratio than absolute Ca content seems to regulate the uptake of metals. Copyright © 2017 Elsevier Inc. All rights reserved.

Department of Defense Annual Cost Analysis Symposium (17th) Held at Arlington, Virginia on 12-15 September 1982.

DTIC Science & Technology

1982-09-01

CA- 2: < C . V D CD LU CD C - U .- LU CA V) u 0.. VA 0 0.. L:U 0. - i LU u A C.D C u- C) LU wU 0.. 00 LUV ) - - ~ z C ci, ci, CA L L >- L" CDU CA 7: U...1 . o i s =Z.~ Irk: c 43- L a a I -cm I -ty Pa ea -~ c.C a I.f oIl sa a 1 !& amv 0-4 P 1- inj 0!6I o. i4. I e S!& I a DIVI ~ a Ip- w o cr 1, -40 e a...Data Entered) ___________________________________________READ INSTRUCTIONS REPORT DOCUMENTATION PAGE BEFORE COMPLETING FORM I . REPORT NUMBER 12. GOVT

Stable coordination of the inhibitory Ca2+ ion at MIDAS in integrin CD11b/CD18 by an antibody-derived ligand aspartate: Implications for integrin regulation and structure-based drug design

PubMed Central

Mahalingam, Bhuvaneshwari; Ajroud, Kaouther; Alonso, Jose Luis; Anand, Saurabh; Adair, Brian; Horenstein, Alberto L; Malavasi, Fabio; Xiong, Jian-Ping; Arnaout, M. Amin

2011-01-01

A central feature of integrin interaction with physiologic ligands is the monodentate binding of a ligand carboxylate to a Mg2+ ion hexacoordinated at the metal-ion-dependent-adhesion site (MIDAS) in the integrin A-domain. This interaction stabilizes the A-domain in the high-affinity state, which is distinguished from the default low-affinity state by tertiary changes in the domain that culminate in cell adhesion. Small molecule ligand-mimetic integrin antagonists act as partial agonists, eliciting similar activating conformational changes in the A-domain, which has contributed to paradoxical adhesion and increased patient mortality in large clinical trials. As with other ligand-mimetic integrin antagonists, the function-blocking monoclonal antibody (mAb) 107 binds MIDAS of integrin CD11b/CD18 A-domain (CD11bA), but in contrast, it favors the inhibitory Ca2+ ion over Mg2+ at MIDAS. We determined the crystal structures of the Fab fragment of mAb 107 complexed to the low- and high-affinity states of CD11bA. Favored binding of Ca2+ at MIDAS is caused by the unusual symmetric bidentate ligation of a Fab-derived ligand Asp to a heptacoordinated MIDAS Ca2+. Binding of Fab 107 to CD11bA did not trigger the activating tertiary changes in the domain or in the full-length integrin. These data show that denticity of the ligand Asp/Glu can modify divalent cation selectivity at MIDAS and hence integrin function. Stabilizing the Ca2+ ion at MIDAS by bidentate ligation to a ligand Asp/Glu may provide one approach for designing pure integrin antagonists. PMID:22095715

Comparison of competitive exclusion with classical cleaning and disinfection on bacterial load in pig nursery units.

PubMed

Luyckx, K; Millet, S; Van Weyenberg, S; Herman, L; Heyndrickx, M; Dewulf, J; De Reu, K

2016-09-06

Colonisation of the environment of nursery units by pathogenic micro-organisms is an important factor in the persistence and spread of endemic diseases in pigs and zoonotic pathogens. These pathogens are generally controlled by the use of antibiotics and disinfectants. Since an increasing resistance against these measures has been reported in recent years, methods such as competitive exclusion (CE) are promoted as promising alternatives. This study showed that the infection pressure in CE units after microbial cleaning was not reduced to the same degree as in control units. Despite sufficient administration of probiotic-type spores, the analysed bacteria did not decrease in number after 3 production rounds in CE units, indicating no competitive exclusion. In addition, no differences in feed conversion were found between piglets raised in CE and control units in our study. Also, no differences in faecal consistency (indicator for enteric diseases) was noticed. These results indicate that the CE protocol is not a valuable alternative for classical C&D.

Geosphere-biosphere circulation of chemical elements in soil and plant systems from a 100 km transect from southern central Norway.

PubMed

Reimann, Clemens; Fabian, Karl; Flem, Belinda; Andersson, Malin; Filzmoser, Peter; Englmaier, Peter

2018-05-17

Geochemical element separation is studied in 14 different sample media collected at 41 sites along an approximately 100-km long transect north of Oslo. At each site, soil C and O horizons and 12 plant materials (birch/spruce/cowberry/blueberry leaves/needles and twigs, horsetail, braken fern, pine bark and terrestrial moss) were sampled. The observed concentrations of 29 elements (K, Ca, P, Mg, Mn, S, Fe, Zn, Na, B, Cu, Mo, Co, Al, Ba, Rb, Sr, Ti, Ni, Pb, Cs, Cd, Ce, Sn, La, Tl, Y, Hg, Ag) were used to investigate soil-plant relations, and to evaluate the element differentiation between different plants, or between foliage and twigs of the same plant. In relation to the soil C horizon, the O horizon is strongly enriched (O/C ratio > 5) in Ag, Hg, Cd, Sn, S and Pb. Other elements (B, K, Ca, P, S, Mn) show higher concentrations in the plants than in the substrate represented by the C horizon, and often even higher concentrations than in the soil O horizon. Elements like B, K, Ca, S, Mg, P, Ba, and Cu are well tuned to certain concentration levels in most of the plants. This is demonstrated by their lower interquartile variability in the plants than in the soil. Cross-plots of element concentration, variance, and ratios, supported by linear discrimination analysis, establish that different plants are marked by their individual element composition, which is separable from, and largely independent of the natural substrate variability across the Gjøvik transect. Element allocation to foliage or twigs of the same plants can also be separated and thus dominantly depend on metabolism, physiology, and structure linked to biological functions, and only to a lesser degree on the substrate and environmental background. The results underline the importance of understanding the biological mechanisms of plant-soil interaction in order to correctly quantify anthropogenic impact on soil and plant geochemistry. Copyright © 2018 Elsevier B.V. All rights reserved.

Higher prevalence of chronic endometritis in women with endometriosis: a possible etiopathogenetic link.

PubMed

Cicinelli, Ettore; Trojano, Giuseppe; Mastromauro, Marcella; Vimercati, Antonella; Marinaccio, Marco; Mitola, Paola Carmela; Resta, Leonardo; de Ziegler, Dominique

2017-08-01

To evaluate the association between endometriosis end chronic endometritis (CE) diagnosed by hysteroscopy, conventional histology, and immunohistochemistry. Case-control study. University hospital. Women with and without endometriosis who have undergone hysterectomy. Retrospective evaluation of 78 women who have undergone hysterectomy and were affected by endometriosis and 78 women without endometriosis. CE diagnosed based on conventional histology and immunohistochemistry with anti-syndecan-1 antibodies to identify CD138 cells. The prevalence of CE was statistically significantly higher in the women with endometriosis as compared with the women who did not have endometriosis (33 of 78, 42.3% vs. 12 of 78, 15.4% according to hysteroscopy; and 30 of 78, 38.5% vs. 11 of 78, 14.1% according to histology). The women were divided into two groups, 115 patients without CE and 41 patients with CE. With univariate analysis, parity was associated with a lower risk for CE, and endometriosis was associated with a statistically significantly elevated risk of CE. Using multivariate analysis, parity continued to be associated with a lower incidence of CE, whereas endometriosis was associated with a 2.7 fold higher risk. The diagnosis of CE is more frequent in women with endometriosis. Although no etiologic relationships between CE and endometriosis can be established, this study suggests that CE should be considered and if necessary ruled out in women with endometriosis, particularly if they have abnormal uterine bleeding. Identification and appropriate treatment of CE may avoid unnecessary surgery. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Cadmium transfer from contaminated soils to the human body through rice consumption in southern Jiangsu Province, China.

PubMed

Li, Tianyuan; Chang, Qing; Yuan, Xuyin; Li, Jizhou; Ayoko, Godwin A; Frost, Ray L; Chen, Hongyan; Zhang, Xinjian; Song, Yinxian; Song, Wenzhi

2017-06-21

Consumption of crops grown in cadmium-contaminated soils is an important Cd exposure route to humans. The present study utilizes statistical analysis and in vitro digestion experiments to uncover the transfer processes of Cd from soils to the human body through rice consumption. Here, a model was created to predict the levels of bioaccessible Cd in rice grains using phytoavailable Cd quantities in the soil. During the in vitro digestion, a relatively constant ratio between the total and bioaccessible Cd in rice was observed. About 14.89% of Cd in soils was found to be transferred into rice grains and up to 3.19% could be transferred from rice grains to the human body. This model was able to sufficiently predict rice grain cadmium concentrations based on CaCl 2 extracted zinc and cadmium concentrations in soils (R 2 = 0.862). The bioaccessible Cd concentration in rice grains was also able to be predicted using CaCl 2 extracted cadmium from soil (R 2 = 0.892). The models established in this study demonstrated that CaCl 2 is a suitable indicator of total rice Cd concentrations and bioaccessible rice grain Cd concentrations. The chain model approach proposed in this study can be used for the fast and accurate evaluation of human Cd exposure through rice consumption based on the soil conditions in contaminated regions.

Protective role of zinc against the neurotoxicity induced by exposure to cadmium during gestation and lactation periods on hippocampal volume of pups tested in early adulthood.

PubMed

Ben Mimouna, Safa; Chemek, Marouane; Boughammoura, Sana; Haouas, Zohra; Messaoudi, Imed

2018-05-03

The present study was conducted to assess the possible effect of cadmium (Cd) throughout gestation and lactation on the volume of the subregion of the hippocampus as well as the potential protective role of zinc (Zn) against Cd neurotoxicity. For this purpose, female rats received either tap water, Cd, Zn or Cd + Zn in their drinking water during gestation and lactation. At postnatal day 35 (PND35), the male pups were sacrificed, and their brains were taken for histologic, chemical, and biochemical analysis. Hippocampal volume was measured in histologic brain slices using Cavalieri's principle. Zn depletion was observed in the brains of pups issued from mothers exposed to Cd. Biochemical analysis further revealed that Cd exposure significantly increases the superoxide dismutase (SOD) activity, as well as the metallothionein (MT) level. During histologic investigation, our results showed that gestational and lactational exposure to Cd significantly altered and decreased the volume of CA1, CA3 pyramidal cell layer and the dentate gyrus. However, there were no marked differences shown in CA2 subfield. Compared to Cd group, co-treatment with Cd and Zn provided correction of the changes induced by the Cd exposure. These results highlight the protective role of Zn against Cd-induced alteration in the hippocampus which is a crucial structure implicated in learning and memory processes.

Electrically assisted liquid-phase microextraction combined with capillary electrophoresis for quantification of propranolol enantiomers in human body fluids.

PubMed

Tabani, Hadi; Fakhari, Ali Reza; Shahsavani, Abolfath; Gharari Alibabaou, Hossein

2014-05-01

In this study, electromembrane extraction (EME) combined with cyclodextrin (CD)-modified capillary electrophoresis (CE) was applied for the extraction, separation, and quantification of propranolol (PRO) enantiomers from biological samples. The PRO enantiomers were extracted from aqueous donor solutions, through a supported liquid membrane (SLM) consisting of 2-nitrophenyl octyl ether (NPOE) impregnated on the wall of the hollow fiber, and into a 20-μL acidic aqueous acceptor solution into the lumen of hollow fiber. Important parameters affecting EME efficiency such as extraction voltage, extraction time, pH of the donor and acceptor solutions were optimized using a Box-Behnken design (BBD). Then, under these optimized conditions, the acceptor solution was analyzed using an optimized CD-modified CE. Several types of CD were evaluated and best results were obtained using a fused-silica capillary with ammonium acetate (80 mM, pH 2.5) containing 8 mM hydroxypropyl-β-CD as a chiral selector, applied voltage of 18 kV, and temperature of 20°C. The relative recoveries were obtained in the range of 78-95%. Finally, the performance of the present method was evaluated for the extraction and determination of PRO enantiomers in real biological samples. © 2014 Wiley Periodicals, Inc.

Interfacial engineering with ultrathin poly (9,9-di-n-octylfluorenyl-2,7-diyl) (PFO) layer for high efficient perovskite light-emitting diodes

NASA Astrophysics Data System (ADS)

Lin, Chunyan; Chen, Ping; Xiong, ZiYang; Liu, Debei; Wang, Gang; Meng, Yan; Song, Qunliang

2018-02-01

Organic-inorganic hybrid perovskites have attracted great attention in the field of lighting and display due to their very high color purity and low-cost solution-process. Researchers have done a lot of work in realizing high performance electroluminescent devices. However, the current efficiency (CE) of methyl-ammonium lead halide perovskite light-emitting diodes (PeLEDs) still needs to be improved. Herein, we demonstrate the enhanced performance of PeLEDs through introducing an ultrathin poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO) buffer layer between poly(3,4-ethylendioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and CH3NH3PbBr3 perovskite. Compared to the reference device without PFO, the optimal device luminous intensity, the maximum CE, and the maximum external quantum efficiency increases from 8139 cd m-2 to 30 150 cd m-2, from 7.20 cd A-1 (at 6.8 V) to 10.05 cd A-1 (at 6.6 V), and from 1.73% to 2.44%, respectively. The ultrathin PFO layer not only reduces the exciton quenching at the interface between the hole-transport layer and emission layer, but also passivates the shallow-trap ensure increasing hole injection, as well as increases the coverage of perovskite film.

Endothelial adhesion molecules and leukocyte integrins in preeclamptic patients.

PubMed

Haller, H; Ziegler, E M; Homuth, V; Drab, M; Eichhorn, J; Nagy, Z; Busjahn, A; Vetter, K; Luft, F C

1997-01-01

Endothelial cell activation is important in the pathogenesis of preeclampsia; however, the nature of the activation is unknown. We investigated 22 patients with preeclampsia. 29 normotensive pregnancies, and 18 nonpregnant women to test the hypothesis that serum from preeclamptic patients induces expression of intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) and stimulates intracellular free calcium concentrations [Ca2+]i in cultured endothelial cells. We then asked whether the corresponding integrin adhesive counter receptors lymphocyte function-associated antigen-1 (CD11a/CD18), macrophage-1 antigen (CD11b/CD18), p150,95 (CD11c/CD18), and very late activation antigen-4 (CD49/CD29) are increased in patients with preeclampsia. In the pregnant women, the measurements were conducted both before and after delivery. Integrin expression was measured by fluorescent antibody cell sorting analysis using monoclonal antibodies. ICAM-1 and VCAM-1 were analyzed on endothelial cells by enzyme-linked immunosorbent assay. [Ca2+]i was measured with fura 2. Serum from preeclamptic patients increased endothelial cell ICAM-1 expression but not VCAM-1 expression. Preeclamptic patients' serum also increased [Ca2+]i in endothelial cells compared with serum from normal nonpregnant or normal pregnant women. Endothelial cell [Ca2+]i concentrations were correlated with the ICAM-1 expression in preeclamptic patients (r = .80, P < .001) before but not after delivery. Expression of the integrin counter receptors on leukocytes was similarly increased in preclampsia and normal pregnancy compared with the nonpregnant state. The expression decreased significantly after delivery in both groups. Our results demonstrate that serum from preeclamptic women induces increased ICAM-1 surface expression on endothelial cells, while the expression of the integrin counterreceptors was not different. The effect on endothelial cells may be related to an increase in [Ca2+]i. The effect on cultured endothelial cells and the rapid decrease after delivery suggests the presence of a circulating serum factor which increases endothelial cell [Ca2+]i and enhances adhesion molecule expression.

Biaxially oriented CdTe films on glass substrate through nanostructured Ge/CaF2 buffer layers

NASA Astrophysics Data System (ADS)

Lord, R. J.; Su, P.-Y.; Bhat, I.; Zhang, S. B.; Lu, T.-M.; Wang, G.-C.

2015-09-01

Heteroepitaxial CdTe films were grown by metal organic chemical vapor deposition on glass substrates through nanostructured Ge/CaF2 buffer layers which were biaxially oriented. It allows us to explore the structural properties of multilayer biaxial semiconductor films which possess small angle grain boundaries and to test the principle of a solar cell made of such low-cost, low-growth-temperature semiconductor films. Through the x-ray diffraction and x-ray pole figure analysis, the heteroepitaxial relationships of the mutilayered films are determined as [111] in the out-of-plane direction and <1\\bar{1}0>CdTe//<1\\bar{1}0>Ge//{< \\bar{1}10> }{{{CaF}}2} in the in-plane direction. The I-V curves measured from an ITO/CdS/CdTe/Ge/CaF2/glass solar cell test structure shows a power conversion efficiency of ˜η = 1.26%, illustrating the initial success of such an approach. The observed non-ideal efficiency is believed to be due to a low shunt resistance and high series resistance as well as some residual large-angle grain boundary effects, leaving room for significant further improvement.

Field evaluation of in situ remediation of Cd-contaminated soil using four additives, two foliar fertilisers and two varieties of pakchoi.

PubMed

Feng, Renwei; Qiu, Weiwen; Lian, Fei; Yu, Zhihong; Yang, YiXin; Song, Zhengguo

2013-07-30

This study was conducted to determine the optimal planting mode for pakchoi (Brassica rapa chinensis) in Cd-contaminated soil to reduce the accumulation of Cd in the edible parts while maintaining yields. Four additives (red mud (RM), silicon calcium fertiliser (SC), spodium (SP) and calcium magnesium phosphate (CMP)), two foliar fertilisers (Ca and Zn) and two varieties of pakchoi (Aijiaohuang (AJ) and Baixuegongzhu (BX)) were used in this study. The results show that the addition of SC and RM had an effect, but the other additives did not appear to increase the biomasses of AJ and BX. In some cases, the growth responses of AJ and BX to the same treatment were different. Extra additions of Ca or Zn to additive-treated pakchoi did not help the additives stimulate the growth of AJ and BX, except for SC-treated AJ and BX and SP-treated AJ. The SC and CMP additives significantly reduced the available Cd concentration in both the AJ soil and the BX soil; however, they did not significantly decrease the Cd concentration in the aboveground parts of AJ and BX. The RM treatments (for both levels) and some treatments containing SP reduced the available Cd concentration in the soils and reduced the accumulation of Cd in the two pakchoi varieties. Additions of Ca or Zn fertiliser significantly reduced the Cd concentration in the aboveground parts of AJ and BX. However, when Ca or Zn was sprayed on the additive-treated AJ and BX, they did not help the additives reduce the Cd accumulation in the aboveground parts of AJ and BX, except for the additive CMP. This study shows that RM may be an optimal amendment to reduce the accumulation of Cd in the edible part of pakchoi while simultaneously maintaining yields. The utilisation of Ca or Zn as a foliar fertiliser to additive-treated pakchoi showed positive effects only under some conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cochineal dye-induced immediate allergy: Review of Japanese cases and proposed new diagnostic chart.

PubMed

Takeo, Naoko; Nakamura, Masashi; Nakayama, Satoshi; Okamoto, Osamu; Sugimoto, Naoki; Sugiura, Shinichi; Sato, Nayu; Harada, Susumu; Yamaguchi, Masao; Mitsui, Naoya; Kubota, Yumiko; Suzuki, Kayoko; Terada, Makoto; Nagai, Akiyo; Sowa-Osako, Junko; Hatano, Yutaka; Akiyama, Hiroshi; Yagami, Akiko; Fujiwara, Sakuhei; Matsunaga, Kayoko

2018-04-25

Cochineal dye is used worldwide as a red coloring in foods, drinks, cosmetics, quasi-drugs, and drugs. The main component of the red color is carminic acid (CA). Carmine is an aluminum- or calcium-chelated product of CA. CA and carmine usually contain contaminating proteins, including a 38-kDa protein thought to be the primary allergen. Severe allergic reactions manifest as anaphylaxis. The aim of this study was to review all Japanese reported cases and propose useful diagnostic chart. All reported Japanese cases of cochineal dye-induced immediate allergy were reviewed, and newly registered cases were examined by skin prick test (SPT) with cochineal extract (CE) and measurement of CE and carmine-specific serum IgE test. Two-dimensional (2D) western blotting using patient serum was conducted to identify the antigen. Twenty-two Japanese cases have been reported. SPT and the level of specific IgE test indicated that six cases should be newly registered as cochineal dye allergy. All cases were adult females, and all cases except three involved anaphylaxis; 13 cases involved past history of local symptoms associated with cosmetics use. Japanese strawberry juice and fish-meat sausage, and European processed foods (especially macarons made in France) and drinks were recent major sources of allergen. 2D western blotting showed that patient IgE reacted to the 38-kDa protein and other proteins. Serum from healthy controls also weakly reacted with these proteins. SPT with CE and determination of the level of CE and carmine-specific IgE test are useful methods for the diagnosis of cochineal dye allergy. Copyright © 2018 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

Interaction of chelating agents with cadmium in mice and rats.

PubMed Central

Eybl, V; Sýkora, J; Koutenský, J; Caisová, D; Schwartz, A; Mertl, F

1984-01-01

The influence of several chelating agents (CaDTPA, ZnDTPA, CaEDTA, ZnEDTA, DMSA, D-penicillamine and DMPS, DMP and DDC) on the acute toxicity of CdCl2 and on the whole body retention and tissue distribution of cadmium after the IV application of 115mCdCl2 was compared in mice. The chelating agents were applied immediately after the application of cadmium. CaDTPA, ZnDTPA and DMSA appeared to be the most effective antidotes. However, DMSA increased the amount of cadmium retained in kidneys. The treatment of cadmium-poisoned mice with the combination of DMSA (IP) and ZnDTPA (SC) (all the compounds were injected in equimolar dose) decreased the toxicity of cadmium more than treatment with one chelating agents (given in a 2:1 dose). However, by studying the effect of these chelating agents and their combination of the retention and distribution of Cd in mice, it was demonstrated that the combined application of the antidotes showed little or no improvement over the results obtained with the most effective of the individual components. In the urine of rats injected with CdCl2 and treated with the chelating agents (CaDTPA, ZnDTPA, DMSA), the presence of cadmium complexes was demonstrated. The formation of mixed ligand chelates in vivo was not proved. Experiments in mice given a single injection of 115mCd-labeled Cd complexes of DMPS, DMSA and DTPA showed a high retention of cadmium in the organisms after the IV application of CdDMPS and CdDMSA complexes. PMID:6734561

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.

Chemical stability and Ce doping of LiMgAlF 6 neutron scintillator

DOE PAGES

Du, M. H.

2014-11-13

We perform density functional calculations to investigate LiMgAlF 6 as a potential neutron scintillator material. The calculations of enthalpy of formation and phase diagram show that single-phase LiMgAlF 6 can be grown but it should be more difficult than growing LiCaAlF 6 and LiSrAlF 6. Moreover, the formation energy calculations for substitutional Ce show that the concentration of Ce on the Al site is negligible but a high concentration (>1 at.%) of Ce on the Mg site is attainable provided that the Fermi level is more than 5 eV lower than the conduction band minimum. Acceptor doping should promote Cemore » incorporation in LiMgAlF 6.« less

Fractionation of elements by particle size of ashes ejected from Copahue Volcano, Argentina.

PubMed

Gómez, Dario; Smichowski, Patricia; Polla, Griselda; Ledesma, Ariel; Resnizky, Sara; Rosa, Susana

2002-12-01

The volcano Copahue, Neuquén province, Argentina has shown infrequent explosive eruptions since the 18th century. Recently, eruptive activity and seismicity were registered in the period July-October, 2000. As a consequence, ash clouds were dispersed by winds and affected Caviahue village located at about 9 km east of the volcano. Samples of deposited particles from this area were collected during this episode for their chemical analysis to determine elements of concern with respect to the health of the local population and its environment. Different techniques were used to evaluate the distribution of elements in four particle size ranges from 36 to 300 microm. X-ray powder diffraction (XRD) was selected to detect major components namely, minerals, silicate glass, fragments of rocks and sulfurs. Major and minor elements (Al, Ca, Cl, Fe, K, Mg, Mn, Na, S, Si and Ti), were detected by energy dispersive X ray analysis (EDAX). Trace element (As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, U, V and Zn) content was quantified by inductively coupled plasma-mass spectrometry (ICP-MS). Nuclear activation analysis (NAA) was employed for the determination of Ce, Co, Cs, Eu, Hf, La, Lu, Rb, Sc, Sm, Ta and Yb. An enrichment was observed in the smallest size fraction of volcanic ashes for four elements (As, Cd, Cu and Sb) of particular interest from the environmental and human health point of view.

Mitigation of cadmium and arsenic in rice grain by applying different silicon fertilizers in contaminated fields.

PubMed

Wang, Hong-Yan; Wen, Shi-Lin; Chen, Peng; Zhang, Lu; Cen, Kuang; Sun, Guo-Xin

2016-02-01

A field experiment was established to support the hypothesis that application of different silicon (Si) fertilizers can simultaneously reduce cadmium (Cd) and arsenic (As) concentration in rice grain. The "semi-finished product of Si-potash fertilizer" treatment at the high application of 9000 kg/ha (NP+S-KSi9000) significantly reduced the As concentration in rice grain by up to 20.1%, compared with the control. Si fertilization reduces the Cd concentration in rice considerably more than the As concentration. All Si fertilizers apart from sodium metasilicate (Na2SiO3) exhibited a high ability to reduce Cd concentration in rice grain. The Si-calcium (CaSi) fertilizer is the most effective in the mitigation of Cd concentration in rice grain. The CaSi fertilizer applied at 9000 kg/ha (NPK+CaSi9000) and 900 kg/ha (NPK+CaSi900) reduced the Cd concentration in rice grain about 71.5 and 48.0%, respectively, while the Si-potash fertilizer at 900 kg/ha (NP+KSi900), the semi-finished product of Si-potash fertilizer at both 900 kg/ha (NP+S-KSi900) and 9000 kg/ha (NP+S-KSi9000), and the rice straw (NPK+RS) treatments reduced the Cd concentration in rice grain about 42, 26.5, 40.7, and 23.1%, respectively. The results of this investigation demonstrated the potential effects of Si fertilizers in reducing Cd and As concentrations in rice grain.

[Effect of Ca(OH)2 on the cytotoxicity of lipopolysaccharide extracted from Porphyromonas endodontalis in vitro].

PubMed

Guo, Jia-jie; Qiu, Li-hong; Yu, Ya-qiong; Xu, Li-ya; Fan, Yun-qian; Zhong, Ming

2014-02-01

To detect the degradation of Ca(OH)2 on lipopolysaccharide (LPS) extracted from Porphyromonas endodontalis (P.e) in vitro and estimate the influence of P.e LPS pretreated with Ca(OH)2 on the proliferation of MC3T3-E1 cells. The effect of Ca(OH)2 on MC3T3-E1 cell proliferation was detected by methyl thiazolyl tetrazolium (MTT) assay. Then P.e LPS was treated with Ca(OH)2 for 30 mins or 60 mins at 37 degrees centigrade in vitro and the activity of P.e LPS was evaluated by Chromogenic End-point Tachypleus Amebocyte Lysate (CE TAL) test. Finally, MC3T3-E1 cells were exposed to P.e LPS pretreated with 15% Ca(OH)2 for 1, 3 and 5 d, and the cell proliferation was measured using the MTT assay comparing with the P.e LPS control group. SPSS 13.0 software package was used for statistical analysis. Compared with the negative control, exposing cells to 5%, 10% and 15% Ca(OH)2 had greatly promoted MC3T3-E1 cell proliferation. P.e LPS treated with 10% and 15% Ca(OH)2 both presented the best results by CE TAL and significant difference compared with P.e LPS control group. When 10 μg/mL P.e LPS was pretreated with 15% Ca(OH)2, no inhibition of MC3T3-E1 cell proliferation was noted. Ca(OH)2 detoxifies P.e LPS in vitro, mitigates the impact of P.e LPS on MC3T3-E1 cell proliferation. Supported by Science and Technology Projects of Liaoning Province (2011225020).

A novel methodology to investigate isotopic biosignatures

NASA Astrophysics Data System (ADS)

Horner, T. J.; Lee, R. B. Y.; Henderson, G. M.; Rickaby, R. E. M.

2012-04-01

An enduring goal of trace metal isotopic studies of Earth History is to find isotopic 'fingerprints' of life or of life's individual physiochemical processes. Generally, such signatures are sought by relating an isotopic effect observed in controlled laboratory conditions or a well-characterized environment to a more complex system or the geological record. However, such an approach is ultimately limited because life exerts numerous isotopic fractionations on any one element so it is hard to dissect the resultant net fractionation into its individual components. Further, different organisms, often with the same apparent cellular function, can express different isotopic fractionation factors. We have used a novel method to investigate the isotopic fractionation associated with a single physiological process-enzyme specific isotopic fractionation. We selected Cd isotopes since only one biological use of Cd is known, CdCA (a Cd/Zn carbonic anhydrase from the coastal diatom T. Weissflogii). Thus, our investigation can also inform the long standing mystery as to why this generally toxic element appears to have a nutrient-like dissolved isotopic and concentration profile in the oceans. We used the pET-15b plasmid to insert the CdCA gene into the E. coli genome. There is no known biochemical function for Cd in E. coli, making it an ideal vector for studying distinct physiological processes within a single organism. The uptake of Cd and associated isotopic fractionation was determined for both normal cells and those expressing CdCA. It was found that whole cells always exhibited a preference for the light isotopes of Cd, regardless of the expression of CdCA; adsorption of Cd to cell surfaces was not seen to cause isotopic fractionation. However, the cleaning procedure employed exerted a strong control on the observed isotopic composition of cells. Using existing protein purification techniques, we measured the Cd isotopic composition of different subcellular fractions of E. coli (e.g. membranes, cytosol, etc.), including the catalytic metal atoms within CdCA. These experiments allow isotopic exchange reactions to be observed in biological systems at an unparalleled resolution, demonstrating that isotopic fractionation can occur, in vivo, on length scales as small as a few Å. We will explore future applications of this technique using the marine geochemistry of Cd as a case study. This experimental approach has great promise for studying the individual isotopic biosignatures of other biochemical reactions, in particular those which may have been active during early Earth History.

Inhibition of Cardiomyocytes Differentiation of Mouse Embryonic Stem Cells by CD38/cADPR/Ca2+ Signaling Pathway*

PubMed Central

Wei, Wen-Jie; Sun, Hai-Ying; Ting, Kai Yiu; Zhang, Li-He; Lee, Hon-Cheung; Li, Gui-Rong; Yue, Jianbo

2012-01-01

Cyclic adenosine diphosphoribose (cADPR) is an endogenous Ca2+ mobilizing messenger that is formed by ADP-ribosyl cyclases from nicotinamide adenine dinucleotide (NAD). The main ADP-ribosyl cyclase in mammals is CD38, a multi-functional enzyme and a type II membrane protein. Here we explored the role of CD38-cADPR-Ca2+ in the cardiomyogenesis of mouse embryonic stem (ES) cells. We found that the mouse ES cells are responsive to cADPR and possess the key components of the cADPR signaling pathway. In vitro cardiomyocyte (CM) differentiation of mouse ES cells was initiated by embryoid body (EB) formation. Interestingly, beating cells appeared earlier and were more abundant in CD38 knockdown EBs than in control EBs. Real-time RT-PCR and Western blot analyses further showed that the expression of several cardiac markers, including GATA4, MEF2C, NKX2.5, and α-MLC, were increased markedly in CD38 knockdown EBs than those in control EBs. Similarly, FACS analysis showed that more cardiac Troponin T-positive CMs existed in CD38 knockdown or 8-Br-cADPR, a cADPR antagonist, treated EBs compared with that in control EBs. On the other hand, overexpression of CD38 in mouse ES cells significantly inhibited CM differentiation. Moreover, CD38 knockdown ES cell-derived CMs possess the functional properties characteristic of normal ES cell-derived CMs. Last, we showed that the CD38-cADPR pathway negatively modulated the FGF4-Erks1/2 cascade during CM differentiation of ES cells, and transiently inhibition of Erk1/2 blocked the enhanced effects of CD38 knockdown on the differentiation of CM from ES cells. Taken together, our data indicate that the CD38-cADPR-Ca2+ signaling pathway antagonizes the CM differentiation of mouse ES cells. PMID:22908234

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

Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q.; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

2016-01-01

Phytoliths and biomolecular components extracted from ancient plant remains from Chang’an (Xi’an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang’an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE.

Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau.

PubMed

Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

2016-01-07

Phytoliths and biomolecular components extracted from ancient plant remains from Chang'an (Xi'an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang'an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE.

Investigation of the stability of glass-ceramic composites containing CeTi 2 O 6 and CaZrTi 2 O 7 after ion implantation

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

Paknahad, Elham; Grosvenor, Andrew P.

Glass-ceramic composite materials have been investigated for nuclear waste sequestration applications due to their ability to incorporate large amounts of radioactive waste elements. A key property that needs to be understood when developing nuclear waste sequestration materials is how the structure of the material responds to radioactive decay of nuclear waste elements, which can be simulated by high energy ion implantation. Borosilicate glass-ceramic composites containing brannerite-type (CeTi2O6) or zirconolite-type (CaZrTi2O7) oxides were synthesized at different annealing temperatures and investigated after being implanted with high-energy Au ions to mimic radiation induced structural damage. Backscattered electron (BSE) images were collected to investigatemore » the interaction of the brannerite crystallites with the glass matrix before and after implantation and showed that the morphology of the crystallites in the composite materials were not affected by radiation damage. Surface sensitive Ti K-edge glancing angle XANES spectra collected from the implanted composite materials showed that the structures of the CeTi2O6 and CaZrTi2O7 ceramics were damaged as a result of implantation; however, analysis of Si L2,3-edge XANES spectra indicated that the glass matrix was not affected by ion implantation.« less

Investigation of the stability of glass-ceramic composites containing CeTi2O6 and CaZrTi2O7 after ion implantation

NASA Astrophysics Data System (ADS)

Paknahad, Elham; Grosvenor, Andrew P.

2017-12-01

Glass-ceramic composite materials have been investigated for nuclear waste sequestration applications due to their ability to incorporate large amounts of radioactive waste elements. A key property that needs to be understood when developing nuclear waste sequestration materials is how the structure of the material responds to radioactive decay of nuclear waste elements, which can be simulated by high energy ion implantation. Borosilicate glass-ceramic composites containing brannerite-type (CeTi2O6) or zirconolite-type (CaZrTi2O7) oxides were synthesized at different annealing temperatures and investigated after being implanted with high-energy Au ions to mimic radiation induced structural damage. Backscattered electron (BSE) images were collected to investigate the interaction of the brannerite crystallites with the glass matrix before and after implantation and showed that the morphology of the crystallites in the composite materials were not affected by radiation damage. Surface sensitive Ti K-edge glancing angle XANES spectra collected from the implanted composite materials showed that the structures of the CeTi2O6 and CaZrTi2O7 ceramics were damaged as a result of implantation; however, analysis of Si L2,3-edge XANES spectra indicated that the glass matrix was not affected by ion implantation.

Use of reversible hydrides for hydrogen storage

NASA Technical Reports Server (NTRS)

Darriet, B.; Pezat, M.; Hagenmuller, P.

1980-01-01

The addition of metals or alloys whose hydrides have a high dissociation pressure allows a considerable increase in the hydrogenation rate of magnesium. The influence of temperature and hydrogen pressure on the reaction rate were studied. Results concerning the hydriding of magnesium rich alloys such as Mg2Ca, La2Mg17 and CeMg12 are presented. The hydriding mechanism of La2Mg17 and CeMg12 alloys is given.

The ion channel TRPV1 regulates the activation and proinflammatory properties of CD4+ T cells

PubMed Central

Bertin, Samuel; Aoki-Nonaka, Yukari; de Jong, Petrus Rudolf; Stanwood, Shawna R.; Srikanth, Sonal; Lee, Jihyung; To, Keith; Abramson, Lior; Yu, Timothy; Han, Tiffany; Touma, Ranim; Li, Xiangli; González-Navajas, José M.; Herdman, Scott; Corr, Maripat; Fu, Guo; Dong, Hui; Gwack, Yousang; Franco, Alessandra; Jefferies, Wilfred A.; Raz, Eyal

2016-01-01

TRPV1 is a Ca2+-permeable channel mostly studied as a pain receptor in sensory neurons. However, its role in other cell types is poorly understood. Here, we demonstrate that TRPV1 is functionally expressed in CD4+ T cells where it acts as a non-store-operated Ca2+ channel and contributes to T cell receptor (TCR)-induced Ca2+ influx, TCR signaling and T cell activation. In models of T cell-mediated colitis, TRPV1 promotes colitogenic T cell responses and intestinal inflammation. Furthermore, genetic and pharmacological inhibition of TRPV1 in human CD4+ T cells recapitulates the phenotype of murine Trpv1−/− CD4+ T cells. These findings suggest that TRPV1 inhibition could represent a new therapeutic strategy to restrain proinflammatory T cell responses. PMID:25282159

Effects of boron supplements on bones from rats fed calcium and magnesium deficient diets

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

McCoy, H.; Irwin, A.; Kenney, M.A.

1991-03-15

Sixty female, weanling rats were fed, for 6 wks, diets providing: casein, 20; CHO, 40; fat, 40. Vitamins and minerals, except Ca and Mg, were fed according to AIN'76 recommendations. Gp A (control) was fed 100% AIN Ca, Mg and P with no boron (B) added. Gps CD and CD+B were fed 30% AIN Ca and 100% AIN Mg and P; Gps MD and MD+B were fed 20% AIN Mg and 100% AIN Ca and P; Gps CMD and CMD+B were fed 20% AIN Mg, 30% AIN Ca and 100% AIN P. The +B groups were supplemented with B atmore » 12 mcg/g diet. Femurs (F) and 2 vertebrae (V) were scraped clean, weighed, sealed in saline-wet gauze, and refrigerated overnight. Bones were equilibrated at {sup {approximately}}25C. F lengths and diameters at the breakpoint were measured before a 3-point flexure test. V were subjected to a compression test. Maximum force (kg) at breakpoint was recorded. Data for right and left F and for 2 V were pooled. Although DIET' (CD, MD, CMD) affected numerous characteristics of F and V, B supplementation of diets affected only % moisture in F, Ca concentration in dry F and in F ash for CD and CMD diets. Interactions between B and diet affected F Mg concentrations in bone and in ash. Group CMD+B had higher Mg/g F than CMD. B increased Mg/g ash for CMD, decreased it for CD and did not affect it for MD.« less

Coordination of XeF2 to calcium and cadmium hexafluorophosphates(V).

PubMed

Bunic, Tina; Tavcar, Gasper; Tramsek, Melita; Zemva, Boris

2006-02-06

[M(XeF2)5](PF6)2 (M = Ca, Cd) complexes were prepared by the reaction of MF2 and XeF2 under pressure of gaseous PF5 in anhydrous HF as solvent. The coordination sphere of the Ca atom consists of nine fluorine atoms: three from two PF6(-) units (one bidentate and one monodentate) and one from each of six XeF2 molecules. The coordination sphere of the Cd atom consists of eight fluorine atoms: one from each of two PF6(-) units and one from each of six XeF2 molecules. Two of the XeF2 ligands about M in each compound are bridging ligands and are each linked to two M, generating infinite (-M-F-Xe-F-M-F-Xe-F-) chains along the b-axis in the Ca salt and along the c-axis in the Cd compound. The Cd2+ cation is smaller and more electronegative than the Ca2+ cation. These differences account for the higher F ligand coordination in the Ca2+ salt and for other structural features that distinguish them. The different stoichiometry of the PF6(-) salts when compared with their AsF6(-) analogues, which have the composition [M(XeF2)4](AsF6)2 (M = Ca, Cd), is in accord with the lower F ligand charge in the AsF6(-) when compared with that in the PF6(-) compound. Indeed, the AsF6(-) ligand charges appear to be similar to those in the XeF2-bridged species.

Aseptic hydroponics to assess rhamnolipid-Cd and rhamnolipid-Zn bioavailability for sunflower (Helianthus annuus): a phytoextraction mechanism study.

PubMed

Wen, Jia; McLaughlin, Mike J; Stacey, Samuel P; Kirby, Jason K

2016-11-01

The availability of cadmium (Cd) and zinc (Zn) to sunflower (Helianthus annuus) was investigated in rhamnolipid- and ethylenediaminetetraacetic acid (EDTA)-buffered solutions in order to evaluate the influence of aqueous speciation of the metals on their uptake by the plant, in relation to predictions of uptake by the free ion activity model (FIAM). Free metal ion activity was estimated using the chemical equilibrium program MINTEQ or measured by Donnan dialysis. The uptake of Cd followed the FIAM for the EDTA-buffered solution at EDTA concentrations below 0.4 μM; for the rhamnolipid-buffered solution, the uptake of both metals in roots was not markedly affected by increasing rhamnolipid concentrations in solution. This suggests rhamnolipid enhanced metal accumulation in plant roots (per unit free metal in solution) possibly through formation and uptake of lipophilic complexes. The addition of normal Ca concentrations (low millimetre range) to the rhamnolipid uptake solutions reduced Cd accumulation in shoots by inhibiting Cd translocation, whereas it significantly increased Zn accumulation in shoots. This study confirms that although rhamnolipid could enhance accumulation of Cd in plants roots at low Ca supply, it is not suitable for Cd phytoextraction in contaminated soil environments where Ca concentrations in soil solution are orders of magnitude greater than those of Cd.

Synthesis, characteristics and thermoluminescent dosimetry features of γ-irradiated Ce doped CaF2 nanophosphor.

PubMed

Zahedifar, M; Sadeghi, E; Mozdianfard, M R; Habibi, E

2013-08-01

Nanoparticles of cerium doped calcium fluoride (CaF2:Ce) were synthesized for the first time using the hydrothermal method. The formation of nanostructures was confirmed by X-ray diffraction (XRD) patterns, indicating cubic lattice structure for the particles produced. Their shape and size were observed by scanning electron microscopy (SEM). Thermoluminescence characteristics were studied by having the samples irradiated by gamma rays of (60)Co source. The optimum thermal treatment of 400 °C for 30 min was found for the produced nanoparticles. The Tm-Tstop and computerized glow curve deconvolution (CGCD) methods, used to determine the number of component glow peaks and kinetic parameters, indicated seven overlapping glow peaks on the TL glow curve at approximately 394, 411, 425, 445, 556, 594 and 632 K. A linear dose response of up to 2000 Gy, was observed for the prepared nanoparticles. Maximum TL sensitivity was found at 0.4 mol% of Ce impurity. Other TL dosimetry features, including reusability and fading, were also presented and discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Superficial roughness on composite surface, composite enamel and composite dentin junctions after different finishing and polishing procedures. Part I: roughness after treatments with tungsten carbide vs diamond burs.

PubMed

Ferraris, Federico; Conti, Alessandro

2014-01-01

The aim of this study is to investigate different instruments for finishing composite restorations, as well as examining different surfaces and interfaces of the same restoration. The null hypothesis is represented by the fact that there are no significant differences on roughness of composite restorations finishing between tungsten carbide and diamond burs, furthermore the null hypothesis is that there are no significant differences on roughness between finishing on composite surfaces (C), compositeenamel (CE) and composite-dentin (CD) interfaces. The study was performed on 28 teeth, and class V cavities were prepared on the extracted teeth. Restorations were done in Filtek XTE nanofilled composite (3M Espe) in a standardized method, to then be finished. A comparison was made in the phase 1 between tungsten carbide burs (16 blades), diamond burs (46 μm), with a similar shape by the same manufacturer (Komet). Each surface received 5 bur applications. Consequently, an analysis with a profilometer was performed. Phase 2 involved further confrontation of ulterior finishing with ultrafine tungsten carbide burs (30 blades) and with extra and ultrafine diamond burs (25 and 8 μm) (the same shape as previously mentioned). A second analysis was then performed with a profilometer. All measurements were taken on C surfaces, CE and CD interfaces. Statistical analyses were carried out with c2 test (a = 0.05). The finishing procedures with fine grit or toothing burs gave a better smoothness with tungsten carbide burs compared to diamond burs. While with the ultrafine grit no significant differences were noted between tungsten carbide and diamond burs on the CE and CD interfaces, the diamond bur left less superficial roughness on the C surfaces. With regards to the superficial roughness of the different areas of restoration, it can be concluded that: minor roughness was detected on C surfaces, while the CD interface had the most superficial roughness, regardless of whether the diamond burs or tungsten carbide burs were used. This study shows some statistical differences that could not be clinically perceivable. The clinical relevance could be resumed as follows: the fine tungsten carbide burs provided less roughness compared to a fine diamond bur. There were no differences between the ultrafine tungsten carbide and diamond burs. The less favourable interface to be finished is CD, compared to the CE interface and C surfaces.

The apoptotic members CD95, BclxL, and Bcl-2 cooperate to promote cell migration by inducing Ca2+ flux from the endoplasmic reticulum to mitochondria

PubMed Central

Fouqué, A; Lepvrier, E; Debure, L; Gouriou, Y; Malleter, M; Delcroix, V; Ovize, M; Ducret, T; Li, C; Hammadi, M; Vacher, P; Legembre, P

2016-01-01

Metalloprotease-processed CD95L (cl-CD95L) is a soluble cytokine that implements a PI3K/Ca2+ signaling pathway in triple-negative breast cancer (TNBC) cells. Accordingly, high levels of cl-CD95L in TNBC women correlate with poor prognosis, and administration of this ligand in an orthotopic xenograft mouse model accelerates the metastatic dissemination of TNBC cells. The molecular mechanism underlying CD95-mediated cell migration remains unknown. Here, we present genetic and pharmacologic evidence that the anti-apoptotic molecules BclxL and Bcl-2 and the pro-apoptotic factors BAD and BID cooperate to promote migration of TNBC cells stimulated with cl-CD95L. BclxL was distributed in both endoplasmic reticulum (ER) and mitochondrion membranes. The mitochondrion-localized isoform promoted cell migration by interacting with voltage-dependent anion channel 1 to orchestrate Ca2+ transfer from the ER to mitochondria in a BH3-dependent manner. Mitochondrial Ca2+ uniporter contributed to this flux, which favored ATP production and cell migration. In conclusion, this study reveals a novel molecular mechanism controlled by BclxL to promote cancer cell migration and supports the use of BH3 mimetics as therapeutic options not only to kill tumor cells but also to prevent metastatic dissemination in TNBCs. PMID:27367565

Cotransfection of DC with TLR4 and MART-1 RNA induces MART-1-specific responses.

PubMed

Abdel-Wahab, Zeinab; Cisco, Robin; Dannull, Jens; Ueno, Tomio; Abdel-Wahab, Omar; Kalady, Matthew F; Onaitis, Mark W; Tyler, Douglas S; Pruitt, Scott K

2005-04-01

Cotransfection of dendritic cells (DC) with MART-1 and constitutively active TLR4 (caTLR4) RNA enhances the maturation of DC. Immature DC were cotransfected with RNA constructs encoding MART-1 and caTLR4, and CTL responses were analyzed. Cotransfection of DC with MART-1 + caTLR4 enhanced the expression of CD80 and CD83 surface markers and increased the secretion of cytokines IL-6, IL-12, and TNFalpha. Neither the native nor the A27L-modified MART-1 RNA could induce significant DC maturation or cytokine secretion. More importantly, DC cotransfected with caTLR4 + MART-1 RNA induced MART-1-specific CTL responses of a higher magnitude than DC transfected with either the native or A27L MART-1 RNA. When the MART-1 RNA-transfected DC were treated with DC-maturing cytokines, the induced CTL were less frequent and less lytic than those induced with MART-1 + caTLR4. A 2- to 100-fold increase in MART-1 tetramer+ cells and 2- to 10-fold increases in IFNgamma secretion and cytotoxicity were seen in CTL induced with MART-1 + caTLR4 compared to CTL induced with either MART-1 or A27L RNA. CTL induced with the mixed RNA displayed high percentages of CD8+ cells coexpressing CD45RA, CD56, and 2B4 antigens. Transfection with caTLR4 alone induced DC maturation, but did not induce lytic CTL, suggesting that CTL responses were induced solely by MART-1 epitopes. caTLR4 increases the CTL-inducing capacity of DC generating a lytic response specific for the accompanying antigen. These results demonstrate the possibility of enhancing the immunogenicity of the native MART-1 and other RNA derived from weakly immunogenic tumors in DC-based immunotherapy.

Rational design of a conformation-switchable Ca2+- and Tb3+-binding protein without the use of multiple coupled metal-binding sites.

PubMed

Li, Shunyi; Yang, Wei; Maniccia, Anna W; Barrow, Doyle; Tjong, Harianto; Zhou, Huan-Xiang; Yang, Jenny J

2008-10-01

Ca2+, as a messenger of signal transduction, regulates numerous target molecules via Ca2+-induced conformational changes. Investigation into the determinants for Ca2+-induced conformational change is often impeded by cooperativity between multiple metal-binding sites or protein oligomerization in naturally occurring proteins. To dissect the relative contributions of key determinants for Ca2+-dependent conformational changes, we report the design of a single-site Ca2+-binding protein (CD2.trigger) created by altering charged residues at an electrostatically sensitive location on the surface of the host protein rat Cluster of Differentiation 2 (CD2).CD2.trigger binds to Tb3+ and Ca2+ with dissociation constants of 0.3 +/- 0.1 and 90 +/- 25 microM, respectively. This protein is largely unfolded in the absence of metal ions at physiological pH, but Tb3+ or Ca2+ binding results in folding of the native-like conformation. Neutralization of the charged coordination residues, either by mutation or protonation, similarly induces folding of the protein. The control of a major conformational change by a single Ca2+ ion, achieved on a protein designed without reliance on sequence similarity to known Ca2+-dependent proteins and coupled metal-binding sites, represents an important step in the design of trigger proteins.

Phytoaccumulation, interaction, toxicity and remediation of cadmium from Helianthus annuus L. (sunflower).

PubMed

Mani, Dinesh; Sharma, Bechan; Kumar, Chitranjan

2007-07-01

An investigation was conducted to study the interaction between Cd and Ca, Zn and organic matter for Cd-phytoremediation in sunflower on the alluvium soil of the Sheila Dhar Institute (SDI) experimental farm, Allahabad (India). Application of 40 ppm Zn produced 11.18% extra dry matter (DM) content and 5.8% extra seed yield over the control. We recommended 1.0% Ca, 40 ppm Zn and 20 tons/ha of compost to enhance dry matter yield and diminish the Cd accumulation in 15 ppm Cd- ethylenediaminetetraacetic (EDTA)-treated plots up to 1/12 folds in sunflower (<0.21 ppm), which indicated phytoremediation of Cd-contaminated soil through soil-plant-rhizospheric processes.

Cation hydrolysis and the regulation of trace metal composition in seawater

NASA Astrophysics Data System (ADS)

Kumar, M. Dileep

1987-08-01

Thermodynamic calculations have been performed for cation hydrolysis, including temperatures from 2°C to the high values of significance near Mid-Oceanic Ridge Systems (MORS). Eighteen elements with wide range of residence times ( t) in seawater (Mn, Th, Al, Bi, Ce, Co, Cr(III), Fe, Nd, Pb, Sc, Sm, Ag, Cd, Cu, Hg, Ni and Zn) have been considered. A model for the regulation of trace metal composition in seawater by cation hydrolytic processes, including those at MORS, is presented. Results show an increase in the abundance of neutral metal hydroxyl species with increase in temperature. During hydrothermal mixing, as the temperature increases, transformation from lower positive hydroxyl complexes to higher or neutral complexes would occur for Cd, Ce, Co, Cr(III), Cu, Mn, Nd, Ni, Pb, Sm and Zn. pH values for adsorption of the metal ion onto solid surfaces have direct relation with pH values of hydrolysis. Co, Mn and Pb could be oxidized to higher states (at Mn-oxide surfaces) that would occur even at MORS. Ce can also be oxidized at 25°C. Solubility calculations show that Al, Bi, Cr(III), Sc, Fe and Th are saturated while Ce, Nd and Sm are not with respect to their oxyhydroxide solids at their concentrations in seawater at 25°C. Cu, Hg, Ni and Zn reach saturation equilibrium at 250°C, whereas Co, Mn and Pb exhibit unsaturation. The results suggest an increase in scavenging capacity of a cation with rise in temperature.

CD10-bearing fibroblast inhibits matrigel invasive potency of interleukin-1α-producing squamous cell carcinoma by diminishing substance P levels in the tumor microenvironment.

PubMed

Xie, Lining; Moroi, Yoichi; Tsuji, Gaku; Liu, Min; Hayashida, Sayaka; Takahara, Masakazu; Fukagawa, Shuji; Takeuchi, Satoshi; Shan, Baoen; Nakahara, Takeshi; Uchi, Hiroshi; Yokomizo, Takehiko; Furue, Masutaka

2010-12-01

CD10 is a neutral endopeptidase, which cleaves various peptide substrates including substance P. CD10 expression has been detected in peritumoral fibroblasts (Fb) within the invasive area of various cancers such as squamous cell carcinoma (SCC). However, the biological significance of CD10-bearing Fb remains largely unknown. We examined dynamic interactions of Fb with tumorigenic A431 SCC cells or non-tumorigenic HaCaT squamous cells. The SCC and HaCaT cells did not synthesize CD10, while Fb constitutively expressed CD10. When co-cultured, SCC markedly upregulated fibroblastic CD10 expression compared with HaCaT, which was mainly attributable to SCC-derived interleukin-1α (IL-1α). Both SCC and Fb autonomously secreted substance P, which eventually enhanced the invasive capacity of SCC in a matrigel invasion assay by upregulating matrix metalloproteinase (MMP)-1 and MMP-2, but not MMP-9. Transfection of siRNA for CD10 successfully knocked down the CD10 expression in Fb (CD10ND-Fb). In the presence of CD10ND-Fb, substance P levels in supernatants as well as MMP production and the invasive potency of SCC were significantly augmented compared with control scramble RNA-transfected Fb. We also transfected CD10 vector to Fb and found that the matrigel invasive ability of SCC cells was downregulated co-cultured with CD10 vector-transfected Fb rather than empty vector-transfected Fb. In conclusion, the CD10-bearing Fb generated by SCC-derived IL-1 inhibited the invasive capacity of SCC by diminishing the microenvironmental concentration of substance P. © 2010 Japanese Cancer Association.

Enantioseparation of thalidomide and its hydroxylated metabolites using capillary electrophoresis with various cyclodextrins and their combinations as chiral buffer additives.

PubMed

Meyring, M; Chankvetadze, B; Blaschke, G

1999-09-01

The separation of thalidomide (TD) and its hydroxylated metabolites including their simultaneous enantioseparation was studied in capillary electrophoresis (CE) using four different randomly substituted charged cyclodextrin (CD) derivatives, the combinations of some of them with each other, and beta-CD. TD, as well as two metabolites recently found in incubations of human liver microsomes and human blood, 5-hydroxythalidomide (5-OH-TD) and one of the diastereomeric 5'-hydroxythalidomides (5'-OH-TD), are neutral compounds. Therefore, they were resolved using charged chiral selectors in CE. Two different separation modes (normal polarity and carrier mode) and two different capillaries (fused-silica and polyacrylamide-coated) were tested. Based on the behavior of the individual CDs, their designed combinations were selected in order to improve the separation selectivity and enantioselectivity. Under optimized conditions all three chiral compounds and their enantiomers were resolved simultaneously.

A mid-twentieth century reduction in tropical upwelling inferred from coralline trace element proxies

NASA Astrophysics Data System (ADS)

Reuer, Matthew K.; Boyle, Edward A.; Cole, Julia E.

2003-05-01

The Cariaco Basin is an important archive of past climate variability given its response to inter- and extratropical climate forcing and the accumulation of annually laminated sediments within an anoxic water column. This study presents high-resolution surface coral trace element records ( Montastrea annularis and Siderastrea siderea) from Isla Tortuga, Venezuela, located within the upwelling center of this region. A two-fold reduction in Cd/Ca ratios (3.5-1.7 nmol/mol) is observed from 1946 to 1952 with no concurrent shift in Ba/Ca ratios. This reduction agrees with the hydrographic distribution of dissolved cadmium and barium and their expected response to upwelling. Significant anthropogenic variability is also observed from Pb/Ca analysis, observing three lead maxima since 1920. Kinetic control of trace element ratios is inferred from an interspecies comparison of Cd/Ca and Ba/Ca ratios (consistent with the Sr/Ca kinetic artifact), but these artifacts are smaller than the environmental signal and do not explain the Cd/Ca transition. The trace element records agree with historical climate data and differ from sedimentary faunal abundance records, suggesting a linear response to North Atlantic extratropical forcing cannot account for the observed historical variability in this region.

Mission Connect Mild TBI Translational Research Consortium

DTIC Science & Technology

2010-08-01

Grill RJ, Parsley MA, Unabia G, Hulsebosch CE. Anti- inflammatory treatment of traumatic brain injury (TBI). Society for Neuroscience, 2009...Hulsebosch, CD, DeWitt DS, Dash PK, Grill RJ, Parsley MA, Unabia, BC, Rea HC, & Perez-Polo, JR Role of IL-1 and TNF receptor activation in neurological...deficits at TBI. Military health Research Forum, 2009. Hulsebosch, CD, DeWitt DS, Dash PK, Grill RJ, Parsley MA, Unabia, BC, Rea HC, & Perez-Polo, JR

Risk Factors for Chorioamnion Infection and Adverse Pregnancy Outcome Among Active-Duty Military women and Dependent Women

DTIC Science & Technology

1998-10-01

0 00 012 IIOTI -- 00 0 Z 0 0 REFERENCES 1. McGann, E. F., Winchester, M. I., Carter, D . P ., Martin, J. N., Jr., Bass, D ., Morrison, J. C. Factors...Women: 1982-1992. 0a014 14. Magann, E. F., Winchester, M. I., Carter, D . P ., Martin, J. N., Jr., Bass, D ., and Morrison, J. C. Factors adversely...D ZHI CE) 10T CD ZC I eC-) 3Z co 00 000 CD CD) z_ < zll CD 1a 1 1 S C) I 1 icD=---I i !! Iz .i 3, z6 z,- !0 D Iz~=3 S--I_ 11001D The current C

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

CD22 ligation inhibits downstream B cell receptor signaling and Ca(2+) flux upon activation.

PubMed

Sieger, N; Fleischer, S J; Mei, H E; Reiter, K; Shock, A; Burmester, G R; Daridon, C; Dörner, T

2013-03-01

CD22 is a surface molecule exclusively expressed on B cells that regulates adhesion and B cell receptor (BCR) signaling as an inhibitory coreceptor of the BCR. Central downstream signaling molecules that are activated upon BCR engagement include spleen tyrosine kinase (Syk) and, subsequently, phospholipase Cγ2 (PLCγ2), which results in calcium (Ca(2+)) mobilization. The humanized anti-CD22 monoclonal antibody epratuzumab is currently being tested in clinical trials. This study was undertaken to determine the potential mechanism by which this drug regulates B cell activation. Purified B cells were preincubated with epratuzumab, and the colocalization of CD22 and CD79α, without BCR engagement, was assessed by confocal microscopy. The phosphorylation of Syk (Y348, Y352) and PLCγ2 (Y759) as well as the Ca(2+) flux in the cells were analyzed by flow cytometry upon stimulation of the BCR and/or Toll-like receptor 9 (TLR-9). The influence of CD22 ligation on BCR signaling was assessed by pretreating the cells with epratuzumab or F(ab')(2) fragment of epratuzumab, in comparison with control cells (medium alone or isotype-matched IgG1). Epratuzumab induced colocalization of CD22 and components of the BCR independent of BCR engagement, and also reduced intracellular Ca(2+) mobilization and diminished the phosphorylation of Syk and PLCγ2 after BCR stimulation in vitro. Inhibition of kinase phosphorylation was demonstrated in both CD27- and CD27+ B cells, and this appeared to be independent of Fc receptor signaling. Preactivation of the cells via the stimulation of TLR-9 did not circumvent the inhibitory effect of epratuzumab on BCR signaling. These findings are consistent with the concept of targeting CD22 to raise the threshold of BCR activation, which could offer therapeutic benefit in patients with autoimmune diseases. Copyright © 2013 by the American College of Rheumatology.

Kondo lattice heavy fermion behavior in CeRh2Ga2

NASA Astrophysics Data System (ADS)

Anand, V. K.; Adroja, D. T.; Bhattacharyya, A.; Klemke, B.; Lake, B.

2017-04-01

The physical properties of an intermetallic compound CeRh2Ga2 have been investigated by magnetic susceptibility χ (T) , isothermal magnetization M(H), heat capacity {{C}\\text{p}}(T) , electrical resistivity ρ (T) , thermal conductivity κ (T) and thermopower S(T) measurements. CeRh2Ga2 is found to crystallize with CaBe2Ge2-type primitive tetragonal structure (space group P4/nmm). No evidence of long range magnetic order is seen down to 1.8 K. The χ (T) data show paramagnetic behavior with an effective moment {μ\\text{eff}}≈ 2.5~{μ\\text{B}} /Ce indicating Ce3+ valence state of Ce ions. The ρ (T) data exhibit Kondo lattice behavior with a metallic ground state. The low-T {{C}\\text{p}}(T) data yield an enhanced Sommerfeld coefficient γ =130(2) mJ/mol K2 characterizing CeRh2Ga2 as a moderate heavy fermion system. The high-T {{C}\\text{p}}(T) and ρ (T) show an anomaly near 255 K, reflecting a phase transition. The κ (T) suggests phonon dominated thermal transport with considerably higher values of Lorenz number L(T) compared to the theoretical Sommerfeld value L 0.

Modeling the interaction and toxicity of Cu-Cd mixture to wheat roots affected by humic acids, in terms of cell membrane surface characteristics.

PubMed

Wang, Yi-Min; Zhou, Dong-Mei; Yuan, Xu-Yin; Zhang, Xiao-Hui; Li, Yi

2018-05-01

Responses of wheat (Triticum aestivum L.) seedling roots to the mixtures of copper (Cu), cadmium (Cd) and humic acids (HA) were investigated using the solution culture experiments, focusing on the interaction patterns between multiple metals and their influences on root proton release. A concentration-addition multiplication (CA) model was introduced into the modeling analysis. In comparison with metal ion activities in bulk-phase solutions, the incorporation of ion activities at the root cell membrane surfaces (CMs) (denoted as {Cu 2+ } 0 and {Cd 2+ } 0 ) into the CA model could significantly improve their correlation with RRE (relative root elongation) from 0.819 to 0.927. Modeling analysis indicated that the co-existence of {Cu 2+ } 0 significantly enhanced the rhizotoxicity of {Cd 2+ } 0 , while no significant effect of {Cd 2+ } 0 on the {Cu 2+ } 0 rhizotoxicity. 10 mg/L HA stimulated the root elongation even under metal stress. Although high concentration of metal ions inhibited the root proton release rate (ΔH + ), both the low concentration of metal ions and HA treatments increased the values of ΔH + . In HA-Cu-Cd mixtures, actions of metal ions on ΔH + values were varied intricately among treatments but well modeled by the CA model. We concluded from the CA models that the electrostatic effect is vitally important for explaining the effect of {Cu 2+ } 0 on the rhizotoxicity of {Cd 2+ } 0 , while it plays no unique role in understanding the influence of {Cd 2+ } 0 on the rhizotoxicity of {Cu 2+ } 0. Thus our study provide a novel way for modeling multiple metals behaviors in the environment and understanding the mechanisms of ion interactions. Copyright © 2018 Elsevier Ltd. All rights reserved.

CHEMICAL ANALYSIS OF A CARBON-ENHANCED VERY METAL-POOR STAR: CD-27 14351

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

Karinkuzhi, Drisya; Goswami, Aruna; Masseron, Thomas

2017-01-01

We present, for the first time, an abundance analysis of a very metal-poor carbon-enhanced star CD-27 14351 based on a high-resolution ( R  ∼ 48,000) FEROS spectrum. Our abundance analysis performed using local thermodynamic equilibrium model atmospheres shows that the object is a cool star with stellar atmospheric parameters, effective temperature T {sub eff} = 4335 K, surface gravity log g  = 0.5, microturbulence ξ  = 2.42 km s{sup −1}, and metallicity [Fe/H] = −2.6. The star exhibits high carbon and nitrogen abundances with [C/Fe] = 2.89 and [N/Fe] = 1.89. Overabundances of neutron-capture elements are evident in Ba, La, Ce, and Nd, with estimated [X/Fe] > 1, the largest enhancementmore » being seen in Ce with [Ce/Fe] = 2.63. While the first peak s -process elements Sr and Y are found to be enhanced with respect to Fe, ([Sr/Fe] = 1.73 and [Y/Fe] = 1.91), the third peak s -process element Pb could not be detected in our spectrum at the given resolution. Europium, primarily an r -process element also shows an enhancement with [Eu/Fe] = 1.65. With [Ba/Eu] = 0.12, the object CD-27 14351 satisfies the classification criterion for a CEMP-r/s star. The elemental abundance distributions observed in this star are discussed in light of the chemical abundances observed in other CEMP stars in the literature.« less

Formulation of Newcastle disease virus coupled calcium phosphate nanoparticles: an effective strategy for oculonasal delivery to chicken.

PubMed

Viswanathan, Kaliyaperumal; Gopinath, Vadivel Ponnuswamy; Raj, Gopal Dhinakar

2014-04-01

In this report, calcium phosphate (CaP) nanoparticles were synthesized by continuous flow method using β-cyclodextrin (β-CD) as a medium and functionalized with amino propyl triethoxy silane (APTES). The blood biocompatibility of the nanoparticles was assessed using the whole blood haemolysis, erythrocytes haemolysis and erythrocyte aggregation tests. Based on the results, we found that the synthesized β-CD-CaP nanoparticles did not cause any remarkable toxic effect. The 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium bromide (MTT) assay of chicken peripheral blood mononucleated cells (PBMCs) incubated with these nanoparticles indicated that these particles did not exert any significant cytotoxicity. The aminosilane functional group modified β-CD-CaP was used as tool for coupling of Newcastle disease virus (NDV). The NDV conjugated nanoparticles were confirmed by using Fourier transformed infrared spectroscopy, X-ray diffraction patterns, Raman spectroscopy differential scanning calorimetry and energy-dispersive X-ray spectroscopy. Immunogenicity trials in chickens proved that β-CD-CaP-NDV used as a vaccine was better than the commercial vaccine when given oculonasally during the first 2 weeks post vaccination. The birds vaccinated with the above nano-NDV vaccine were completely protected against virulent NDV challenge. This study confirms that the oculonasal β-CD-CaP-NDV delivery of vaccines is a potential method for enhancing the immune responses of existing commercial vaccines. Copyright © 2013 Elsevier B.V. All rights reserved.

Distribution of Cd and other cations between the stroma and thylakoids: a quantitative approach to the search for Cd targets in chloroplasts.

PubMed

Lysenko, Eugene A; Klaus, Alexander A; Kartashov, Alexander V; Kusnetsov, Victor V

2018-06-21

Plant growth and photosynthetic activity are usually inhibited due to the overall action of Cd on a whole organism, though few cadmium cations can invade chloroplasts in vivo. We found that in vivo, the major portion of Cd in barley chloroplasts is located in the thylakoids (80%), and the minor portion is in the stroma (20%). Therefore, the electron-transport chain in the thylakoids would be the likely target for direct Cd action in vivo. In vitro, we found the distribution of Cd to be shifted to the stroma (40-60%). In barley chloroplasts, the major portions of Mg, Fe, Mn, and Cu were found to be located in the thylakoids, and most Ca, Zn, and K in the stroma. This finding was true for both control and Cu- or Fe-treated plants. Treatment with Cd affected the contents of all cations, and the largest portions of Ca and Zn were in the thylakoids. Alterations of the K and Mn contents were caused by Cd, Cu, or Fe treatment; the levels of other cations in chloroplasts were changed specifically by Cd treatment. The quantity of Cd in chloroplasts was small in comparison to that of Mg, Ca, and Fe. In thylakoids, the amount of Cd was similar to that of Cu and comparable to the levels of Zn and Mn. Accordingly, the possible targets for direct Cd action in thylakoids are the Mn cluster, plastocyanin, carbonic anhydrase, or FtsH protease. The quantity of Cd in thylakoids is sufficient to replace a cation nearly completely at one of these sites or partially (20-30%) at many of these sites.

Intracellular Cadmium Isotope Fractionation

NASA Astrophysics Data System (ADS)

Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

2011-12-01

Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

Synthesis, crystal structure, and magnetism of A 2Co 12As 7 (A=Ca, Y, Ce–Yb)

DOE PAGES

Tan, Xiaoyan; Ovidiu Garlea, V.; Chai, Ping; ...

2015-08-28

In this study, ternary intermetallics, A 2Co 12As 7 (A=Ca, Y, Ce–Yb), have been synthesized by annealing mixtures of elements in molten Bi at 1223 K. The materials obtained crystallize in the P6 3/m variant of the Zr 2Fe 12P 7 structure type. The unit cell volume shows a monotonic decrease with the increasing atomic number of the rare-earth metal, with the exception of Ce-, Eu-, and Yb-containing compounds. An examination of these outliers with X-ray absorption near edge structures (XANES) spectroscopy revealed mixed valence of Ce, Eu, and Yb, with the average oxidation states of +3.20(1), +2.47(5), and +2.91(1),more » respectively, at room temperature. Magnetic behavior of A 2Co 12As 7 is generally characterized by ferromagnetic ordering of Co 3d moments at 100–140 K, followed by low-temperature ordering of rare-earth 4f moments. The 3d-4f magnetic coupling changes from antiferromagnetic for A=Pr–Sm to ferromagnetic for A=Ce and Eu–Yb. Finally, polarized neutron scattering experiments were performed to support the postulated ferro- and ferrimagnetic ground states for Ce 2Co 12As 7 and Nd 2Co 12As 7, respectively.« less

The Medieval Climate Anomaly and Little Ice Age in Chesapeake Bay and the North Atlantic Ocean

USGS Publications Warehouse

Cronin, T. M.; Hayo, K.; Thunell, R.C.; Dwyer, G.S.; Saenger, C.; Willard, D.A.

2010-01-01

A new 2400-year paleoclimate reconstruction from Chesapeake Bay (CB) (eastern US) was compared to other paleoclimate records in the North Atlantic region to evaluate climate variability during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA). Using Mg/Ca ratios from ostracodes and oxygen isotopes from benthic foraminifera as proxies for temperature and precipitation-driven estuarine hydrography, results show that warmest temperatures in CB reached 16-17. ??C between 600 and 950. CE (Common Era), centuries before the classic European Medieval Warm Period (950-1100. CE) and peak warming in the Nordic Seas (1000-1400. CE). A series of centennial warm/cool cycles began about 1000. CE with temperature minima of ~. 8 to 9. ??C about 1150, 1350, and 1650-1800. CE, and intervening warm periods (14-15. ??C) centered at 1200, 1400, 1500 and 1600. CE. Precipitation variability in the eastern US included multiple dry intervals from 600 to 1200. CE, which contrasts with wet medieval conditions in the Caribbean. The eastern US experienced a wet LIA between 1650 and 1800. CE when the Caribbean was relatively dry. Comparison of the CB record with other records shows that the MCA and LIA were characterized by regionally asynchronous warming and complex spatial patterns of precipitation, possibly related to ocean-atmosphere processes. ?? 2010.

The role of transient receptor potential vanilloid type-2 ion channels in innate and adaptive immune responses

PubMed Central

Santoni, Giorgio; Farfariello, Valerio; Liberati, Sonia; Morelli, Maria B.; Nabissi, Massimo; Santoni, Matteo; Amantini, Consuelo

2013-01-01

The transient receptor potential vanilloid type-2 (TRPV2), belonging to the transient receptor potential channel family, is a specialized ion channel expressed in human and other mammalian immune cells. This channel has been found to be expressed in CD34+ hematopoietic stem cells, where its cytosolic Ca2+ activity is crucial for stem/progenitor cell cycle progression, growth, and differentiation. In innate immune cells, TRPV2 is expressed in granulocytes, macrophages, and monocytes where it stimulates fMet-Leu-Phe migration, zymosan-, immunoglobulin G-, and complement-mediated phagocytosis, and lipopolysaccharide-induced tumor necrosis factor-alpha and interleukin-6 production. In mast cells, activation of TRPV2 allows intracellular Ca2+ ions flux, thus stimulating protein kinase A-dependent degranulation. In addition, TRPV2 is highly expressed in CD56+ natural killer cells. TRPV2 orchestrates Ca2+ signal in T cell activation, proliferation, and effector functions. Moreover, messenger RNA for TRPV2 are expressed in CD4+ and CD8+ T lymphocytes. Finally, TRPV2 is expressed in CD19+ B lymphocytes where it regulates Ca2+ release during B cell development and activation. Overall, the specific expression of TRPV2 in immune cells suggests a role in immune-mediated diseases and offers new potential targets for immunomodulation. PMID:23420671

Non-Native Metal Ion Reveals the Role of Electrostatics in Synaptotagmin 1-Membrane Interactions.

PubMed

Katti, Sachin; Nyenhuis, Sarah B; Her, Bin; Srivastava, Atul K; Taylor, Alexander B; Hart, P John; Cafiso, David S; Igumenova, Tatyana I

2017-06-27

C2 domains are independently folded modules that often target their host proteins to anionic membranes in a Ca 2+ -dependent manner. In these cases, membrane association is triggered by Ca 2+ binding to the negatively charged loop region of the C2 domain. Here, we used a non-native metal ion, Cd 2+ , in lieu of Ca 2+ to gain insight into the contributions made by long-range Coulombic interactions and direct metal ion-lipid bridging to membrane binding. Using X-ray crystallography, NMR, Förster resonance energy transfer, and vesicle cosedimentation assays, we demonstrate that, although Cd 2+ binds to the loop region of C2A/B domains of synaptotagmin 1 with high affinity, long-range Coulombic interactions are too weak to support membrane binding of individual domains. We attribute this behavior to two factors: the stoichiometry of Cd 2+ binding to the loop regions of the C2A and C2B domains and the impaired ability of Cd 2+ to directly coordinate the lipids. In contrast, electron paramagnetic resonance experiments revealed that Cd 2+ does support membrane binding of the C2 domains in full-length synaptotagmin 1, where the high local lipid concentrations that result from membrane tethering can partially compensate for lack of a full complement of divalent metal ions and specific lipid coordination in Cd 2+ -complexed C2A/B domains. Our data suggest that long-range Coulombic interactions alone can drive the initial association of C2A/B with anionic membranes and that Ca 2+ further augments membrane binding by the formation of metal ion-lipid coordination bonds and additional Ca 2+ ion binding to the C2 domain loop regions.

Cellular Response of Pea Plants to Cadmium Toxicity: Cross Talk between Reactive Oxygen Species, Nitric Oxide, and Calcium1[W][OA

PubMed Central

Rodríguez-Serrano, María; Romero-Puertas, María C.; Pazmiño, Diana M.; Testillano, Pilar S.; Risueño, María C.; del Río, Luis A.; Sandalio, Luisa M.

2009-01-01

Cadmium (Cd) toxicity has been widely studied in different plant species; however, the mechanism involved in its toxicity as well as the cell response against the metal have not been well established. In this work, using pea (Pisum sativum) plants, we studied the effect of Cd on antioxidants, reactive oxygen species (ROS), and nitric oxide (NO) metabolism of leaves using different cellular, molecular, and biochemical approaches. The growth of pea plants with 50 μm CdCl2 affected differentially the expression of superoxide dismutase (SOD) isozymes at both transcriptional and posttranscriptional levels, giving rise to a SOD activity reduction. The copper/zinc-SOD down-regulation was apparently due to the calcium (Ca) deficiency induced by the heavy metal. In these circumstances, the overproduction of the ROS hydrogen peroxide and superoxide could be observed in vivo by confocal laser microscopy, mainly associated with vascular tissue, epidermis, and mesophyll cells, and the production of superoxide radicals was prevented by exogenous Ca. On the other hand, the NO synthase-dependent NO production was strongly depressed by Cd, and treatment with Ca prevented this effect. Under these conditions, the pathogen-related proteins PrP4A and chitinase and the heat shock protein 71.2, were up-regulated, probably to protect cells against damages induced by Cd. The regulation of these proteins could be mediated by jasmonic acid and ethylene, whose contents increased by Cd treatment. A model is proposed for the cellular response to long-term Cd exposure consisting of cross talk between Ca, ROS, and NO. PMID:19279198

ScMO(BO3) (M = Ca and Cd): new Sc-based oxyborates featuring interesting edge-sharing sandwich-like chains and UV cut-off edges.

PubMed

Ma, Ruru; Xu, Dongdong; Yang, Yun; Su, Xin; Lei, Binghua; Yang, Zhihua; Pan, Shilie

2017-11-07

Two new isostructural rare-earth oxyborates ScMO(BO 3 ) (M = Ca and Cd) with a three-dimensional (3D) cationic framework and parallel arranged [BO 3 ] triangles have been synthesized by the flux method. In the 3D cationic framework, an interesting sandwich-like basic building unit (BBU) is constructed by two [Ca(1)O 4 ] 6- chains and two [Sc(1)O 4 ] 5- chains. ScMO(BO 3 ) melt incongruently, which shows that title compounds can be grown by the flux method. The UV cut-off edges for ScCaO(BO 3 ) and ScCdO(BO 3 ) are 230 and 249 nm, respectively. In addition, the first-principles calculations are performed to gain further insights into the relationship between the microscopic electronic structures and associated optical properties.

Moderate Alcohol Drinking and the Amygdala Proteome: Identification and Validation of Calcium/Calmodulin Dependent Kinase II and AMPA Receptor Activity as Novel Molecular Mechanisms of the Positive Reinforcing Effects of Alcohol

PubMed Central

Salling, Michael C.; Faccidomo, Sara P.; Li, Chia; Psilos, Kelly; Galunas, Christina; Spanos, Marina; Agoglia, Abigail E.; Kash, Thomas L.; Hodge, Clyde W.

2015-01-01

BACKGROUND Despite worldwide consumption of moderate amounts of alcohol, the neural mechanisms that mediate the transition from use to abuse are not fully understood. METHODS Here, we conducted a high-through put screen of the amygdala proteome in mice after moderate alcohol drinking (n = 12/group) followed by behavioral studies (n = 6–8/group) to uncover novel molecular mechanisms of the positive reinforcing properties of alcohol that strongly influence the development of addiction. RESULTS Two-dimensional difference in-gel electrophoresis with matrix assisted laser desorption ionization tandem time-of-flight identified 29 differentially expressed proteins in the amygdala of nondependent C57BL/6J mice following 24 days of alcohol drinking. Alcohol-sensitive proteins included calcium/calmodulin-dependent protein kinase II alpha (CaMKIIα) and a network of functionally linked proteins that regulate neural plasticity and glutamate-mediated synaptic activity. Accordingly, alcohol drinking increased α-amino-3-hydroxy-5-methyl-4-isooxazole receptor (AMPAR) in central amygdala (CeA) and phosphorylation of AMPAR GluA1 subunit at a CaMKII locus (GluA1-Ser831) in CeA and lateral amygdala. Further, CaMKIIα-Thr286 and GluA1-Ser831 phosphorylation was increased in CeA and lateral amygdala of mice that lever-pressed for alcohol versus the nondrug reinforcer sucrose. Mechanistic studies showed that targeted pharmacologic inhibition of amygdala CaMKII or AMPAR activity specifically inhibited the positive reinforcing properties of alcohol but not sucrose. CONCLUSIONS Moderate alcohol drinking increases the activity and function of plasticity-linked protein networks in the amygdala that regulate the positive reinforcing effects of the drug. Given the prominence of positive reinforcement in the etiology of addiction, we propose that alcohol-induced adaptations in CaMKIIα and AMPAR signaling in the amygdala may serve as a molecular gateway from use to abuse. PMID:25579851

Elaboration, microstructure, propriétés électriques et magnétiques de matériaux textures dans les systèmes Nd-Ce-Cu-O et Bi-Sr-Ca-Cu-O

NASA Astrophysics Data System (ADS)

Dhalenne, G.; Trouilleux, L.; Jegoudez, J.; Revcolevschi, A.; Monod, P.; Kormann, R.; Ganne, J. P.; Motohira, N.; Kitazawa, K.

1991-11-01

Superconducting textured materials were grown from the melt by a floating zone technique in the Nd-Ce-Cu-O and Bi-Sr-Ca-Cu-O systems. The influence of growth conditions and starting compositions on the microstructures and phase composition of the samples were studied by optical microscopy under polarized light, electron microprobe analysis and X-ray diffraction. The superconducting properties of these samples were examined by both electrical resistivity and magnetic measurements. A very strong influence of the microstructure on the superconducting properties as well as a magnetic and electrical anisotropy were shown. In the case of the Bi-Sr-Ca-Cu-O system, critical current densities ranging from 1 600 to 3 000 A.cm^{-2} were measured at 77 K. Des matériaux supraconducteurs texturés ont été élaborés à partir de l'état liquide dans les systèmes Nd-Ce-Cu-O et Bi-Sr-Ca-Cu-O par une technique de fusion de zone. L'influence des conditions de croissance et des compositions initiales sur la microstructure des échantillons a été étudiée par microscopie optique en lumière polarisée, microsonde électronique et diffraction des rayons X. Les propriétés supraconductrices des échantillons ont été examinées par des mesures électriques et magnétiques. Il a été observé une forte influence de la microstructure sur les propriétés supraconductrices ainsi qu'une anisotropie électrique et magnétique. Dans le cas du système Bi-Sr-Ca-Cu-O, les densités de courant critique mesurées à 77 K sont comprises entre 1 600 et 3 000 A.cm^{-2}.

Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau

PubMed Central

Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q.; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

2016-01-01

Phytoliths and biomolecular components extracted from ancient plant remains from Chang’an (Xi’an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang’an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE. PMID:26738699

Somato-axodendritic release of oxytocin into the brain due to calcium amplification is essential for social memory.

PubMed

Higashida, Haruhiro

2016-07-01

Oxytocin (OT) is released into the brain from the cell soma, axons, and dendrites of neurosecretory cells in the hypothalamus. Locally released OT can activate OT receptors, form inositol-1,4,5-trisphosphate and elevate intracellular free calcium (Ca(2+)) concentrations [(Ca(2+)) i ] in self and neighboring neurons in the hypothalamus, resulting in further OT release: i.e., autocrine or paracrine systems of OT-induced OT release. CD38-dependent cyclic ADP-ribose (cADPR) is also involved in this autoregulation by elevating [Ca(2+)] i via Ca(2+) mobilization through ryanodine receptors on intracellular Ca(2+) pools that are sensitive to both Ca(2+) and cADPR. In addition, it has recently been reported that heat stimulation and hyperthermia enhance [Ca(2+)] i increases by Ca(2+) influx, probably through TRPM2 cation channels, suggesting that cADPR and TRPM2 molecules act as Ca(2+) signal amplifiers. Thus, OT release is not simply due to depolarization-secretion coupling. Both of these molecules play critical roles not only during labor and milk ejection in reproductive females, but also during social behavior in daily life in both genders. This was clearly demonstrated in CD38 knockout mice in that social behavior was impaired by reduction of [Ca(2+)] i elevation and subsequent OT secretion. Evidence for the associations of CD38 with social behavior and psychiatric disorder is discussed, especially in subjects with autism spectrum disorder.

Metformin plus oral contraceptive may decrease plasma sCD40 ligand in women with PCOS patients.

PubMed

Kebapcilar, Levent; Kebapcilar, Ayse Gul; Bilgir, Oktay; Taner, Cuneyt Eftal; Bozkaya, Giray; Yildiz, Yasar; Sari, Ismail

2011-02-01

To evaluate sCD40L levels in women with polycystic ovary syndrome (PCOS) who use combination therapy with metformin and oral contraceptives. Total of 60 patients with PCOS was studied to evaluate and compare with a non-PCOS group consisting of 30 subjects. A low-dose oral contraceptive containing ethinyl oestradiol-cyproterone acetate (EE/CA) and metformin (M; 850 mg metformin twice a day) were given for three cycles. Plasma sCD40L was measured before and after the treatment of 3 months. At baseline, the sCD40L levels of the patients with PCOS was significantly higher than those of control subjects (3.1 ± 2.0 vs. 2.05 ± 1.0, respectively; p=0.002). An average of 3 months of EE/CA-M therapy induced a significant decrease of sCD40L levels in the PCOS group (3.1 ± 2.0 vs. 2.5 ± 1.0; p=0.026). After having treated patients with PCOS, the sCD40L level was not completely normalised when compared to the healthy controls (2.5 ± 1.0 vs. 2.05 ± 1.0; p=0.039). PCOS is associated with elevated levels of sCD40L. Adding metformin therapy to EE/CA may decrease sCD40L levels in women PCOS. However, after the treatment for PCOS subjects, the sCD40L was not completely normalised when compared patients to healthy controls.

A chiral enantioseparation generic strategy for anti-Alzheimer and antifungal drugs by short end injection capillary electrophoresis using an experimental design approach.

PubMed

Abdel-Megied, Ahmed M; Hanafi, Rasha S; Aboul-Enein, Hassan Y

2018-02-01

The present study describes a generic strategy using capillary electrophoretic (CE) method for chiral enantioseparation of anti-Alzheimer drugs, namely, donepezil (DON), rivastigmine (RIV), and antifungal drugs, namely, ketoconazole (KET), Itraconazole (ITR), fluconazole (FLU), and sertaconazole (SRT) in which these drugs have different basic and acidic properties. Several modified cyclodextrins (CDs) were applied for enantioseparation of racemates such as highly sulfated α, γ CDs, hydroxyl propyl-β-CD, and Sulfobutyl ether-β-CD. The starting screening conditions consist of 50-mM phosphate-triethanolamine buffer at pH 2.5, an applied voltage of 15 kV, and a temperature of 25°C. The CE strategy implemented in the separation starts by screening prior to the optimization stage in which an experimental design is applied. The design of experiment (DOE) was based on a full factorial design of the crucial two factors (pH and %CD) at three levels, to make a total of nine (3 2 ) experiments with high, intermediate, and low values for both factors. Evaluation of the proposed strategy pointed out that best resolution was obtained at pH 2.5 for five racemates using low percentages of HS-γ-CD, while SBE-β-CD was the most successful chiral selector offering acceptable resolution for all the six racemates, with the best separation at low pH values and at higher %CD within 10-min runtime. Regression study showed that the linear model shows a significant lack of fit for all chiral selectors, anticipating that higher orders of the factors are most likely to be present in the equation with possible interactions. © 2017 Wiley Periodicals, Inc.

Regulation of gene expression in autoimmune disease loci and the genetic basis of proliferation in CD4+ effector memory T cells.

PubMed

Hu, Xinli; Kim, Hyun; Raj, Towfique; Brennan, Patrick J; Trynka, Gosia; Teslovich, Nikola; Slowikowski, Kamil; Chen, Wei-Min; Onengut, Suna; Baecher-Allan, Clare; De Jager, Philip L; Rich, Stephen S; Stranger, Barbara E; Brenner, Michael B; Raychaudhuri, Soumya

2014-06-01

Genome-wide association studies (GWAS) and subsequent dense-genotyping of associated loci identified over a hundred single-nucleotide polymorphism (SNP) variants associated with the risk of rheumatoid arthritis (RA), type 1 diabetes (T1D), and celiac disease (CeD). Immunological and genetic studies suggest a role for CD4-positive effector memory T (CD+ TEM) cells in the pathogenesis of these diseases. To elucidate mechanisms of autoimmune disease alleles, we investigated molecular phenotypes in CD4+ effector memory T cells potentially affected by these variants. In a cohort of genotyped healthy individuals, we isolated high purity CD4+ TEM cells from peripheral blood, then assayed relative abundance, proliferation upon T cell receptor (TCR) stimulation, and the transcription of 215 genes within disease loci before and after stimulation. We identified 46 genes regulated by cis-acting expression quantitative trait loci (eQTL), the majority of which we detected in stimulated cells. Eleven of the 46 genes with eQTLs were previously undetected in peripheral blood mononuclear cells. Of 96 risk alleles of RA, T1D, and/or CeD in densely genotyped loci, eleven overlapped cis-eQTLs, of which five alleles completely explained the respective signals. A non-coding variant, rs389862A, increased proliferative response (p=4.75 × 10-8). In addition, baseline expression of seventeen genes in resting cells reliably predicted proliferative response after TCR stimulation. Strikingly, however, there was no evidence that risk alleles modulated CD4+ TEM abundance or proliferation. Our study underscores the power of examining molecular phenotypes in relevant cells and conditions for understanding pathogenic mechanisms of disease variants.

Morphological structure and characteristics of hydroxyapatite/β-cyclodextrin composite nanoparticles synthesized at different conditions.

PubMed

Son, Kyoung Dan; Kim, Young-Jin

2013-01-01

Hydroxyapatite (HA) nanoparticles were prepared simply in the presence of β-cyclodextrin (β-CD). Mixing sequence of ion precursors during the synthesis of HA greatly affected the morphological structure of nanoparticles. Ca-P showed only the sphere-like structure, however P-Ca exhibited the mixture of spherical and rod-like nanoparticles. The size of nanoparticles slightly decreased with increasing the content of β-CD. The HAs synthesized in the presence of β-CD agglomerated, leading to the formation of aggregates with a size of hundreds nanometer and narrow size distribution. FT-IR, XRD and XRF analyses confirmed that the HA nanoparticles could be synthesized with using β-CD, in which the Ca/P molar ratio was ranged from 1.72 to 1.70. The crystalline phase of these HA nanoparticles was similar to that of the stoichiometric HA. In addition, the content of β-CD contained in the products could influence the initial deposition rate of bone-like apatite on the surface of HA nanoparticles in simulated body fluid (SBF). Copyright © 2012 Elsevier B.V. All rights reserved.

Evaluation of calcium alginate beads for Ce, La and Nd preconcentration from groundwater prior to ICP OES analysis.

PubMed

Arantes de Carvalho, Gabriel G; Kondaveeti, Stalin; Petri, Denise F S; Fioroto, Alexandre M; Albuquerque, Luiza G R; Oliveira, Pedro V

2016-12-01

Analytical methods for the determination of rare earth elements (REE) in natural waters by plasma spectrochemical techniques often require sample preparation procedures for analytes preconcentration as well as for removing matrix constituents, that may interfere on the analytical measurements. In the present work, calcium alginate (CA) beads were used for the first time aiming at Ce, La and Nd preconcentration from groundwater samples for further determination by inductively coupled plasma optical emission spectrometry (ICP OES). Test samples were analyzed in batch mode by transferring a 40mL test portion (pH=5±0.2) into a 50mL polyethylene flask containing 125mg CA beads. After 15min contact, the analytes were quantitatively extracted from the loaded CA beads with 2.0mL of 1.0molL -1 HCl solution for further determination by ICP OES, using Ce (II) 456.236, La (II) 379.478 and Nd (II) 430.358nm emission lines. The proposed approach is a reliable alternative for REE single-stage preconcentration from aqueous samples, as it provided accurate results based on the addition and recovery analysis of groundwater. The results obtained by the proposed method were also compared with those from reference method based on inductively coupled plasma mass spectrometry (ICP-MS) and no significant differences were observed after applying the Student's t-test at 95% confidence level. Copyright © 2016 Elsevier B.V. All rights reserved.

Simultaneous determination of phenylethanoid glycosides and aglycones by capillary zone electrophoresis with running buffer modifier.

PubMed

Dong, Shuqing; Gao, Ruibin; Yang, Yan; Guo, Mei; Ni, Jingman; Zhao, Liang

2014-03-15

Although the separation efficiency of capillary electrophoresis (CE) is much higher than that of other chromatographic methods, it is sometimes difficult to adequately separate the complex ingredients in biological samples. This article describes how one effective and simple way to develop the separation efficiency in CE is to add some modifiers to the running buffer. The suitable running buffer modifier β-cyclodextrin (β-CD) was explored to fast and completely separate four phenylethanoid glycosides and aglycones (homovanillyl alcohol, hydroxytyrosol, 3,4-dimethoxycinnamic acid, and caffeic acid) in Lamiophlomis rotata (Lr) and Cistanche by capillary zone electrophoresis with ultraviolet (UV) detection. It was found that when β-CD was used as running buffer modifier, a baseline separation of the four analytes could be accomplished in less than 20 min and the detection limits were as low as 10(-3) mg L(-1). Other factors affecting the CE separation, such as working potential, pH value and ionic strength of running buffer, separation voltage, and sample injection time, were investigated extensively. Under the optimal conditions, a successful practical application on the determination of Lr and Cistanche samples confirmed the validity and practicability of this method. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of a natural sepiolite bearing material and lime on the immobilization and persistence of cadmium in a contaminated acid agricultural soil.

PubMed

Cao, Xueying; Hu, Pengjie; Tan, Changyin; Wu, Longhua; Peng, Bo; Christie, Peter; Luo, Yongming

2018-05-25

Soil contamination with cadmium (Cd) represents a substantial threat to human health and environmental quality. Long-term effectiveness and persistence of remediation are two important criteria for the evaluation of amendment techniques used to remediate soils polluted with potentially toxic metals. In the current study, we investigated the remediation persistence of a natural sepiolite bearing material (NSBM, containing 15% sepiolite) and ground limestone (equivalent to > 98.0% CaO) on soil pH, Cd bioavailability, and Cd accumulation by pak choi (Brassica chinensis L.) during the growth of four consecutive crops in a Cd-contaminated acid soil with different amounts of NSBM (0, 0.2, 0.5, 1, 2, and 5%). Soil pH levels ranged from 5.21 to 7.76 during the first crop, 4.30 to 7.34 during the second, 4.23 to 7.80 during the third, and 4.33 to 6.98 during the fourth, and increased significantly with increasing the application rate of NSBM. Soil CaCl 2 -Cd and shoot Cd concentrations decreased by 8.11 to 99.2% and 6.58 to 94.5%, respectively, compared with the control throughout the four cropping seasons. A significant negative correlation was found between soil CaCl 2 -Cd and soil pH. Combined use of 0.1% lime and NSBM showed greater effects than NSBM alone, especially, when the application rate of NSBM was ˂ 2%. Moreover, pak choi tissue Cd concentrations in the treatments with NSBM addition alone at ≥ 2% or at ≥ 1% NSBM combined with 0.1% lime met the maximum permissible concentration (MPC) over the four crops, allowed by the Chinese and European regulations. Based on the present study, safe crop production in the test soil is possible at a soil pH > 6.38 and CaCl 2 -Cd < 14 μg kg -1 , and soil Cd immobilization by NSBM without or with lime is a potentially feasible method of controlling the transfer of soil Cd into the food chain.

Immunological effects of CaEDTA injection: observations in two lead workers.

PubMed

Sata, F; Araki, S; Sakai, T; Nakata, A; Yamashita, K; Morita, Y; Tanigawa, T; Miki, A

1997-12-01

To evaluate the effects of calcium disodium ethylenediamine tetraacetate (CaEDTA) injection on human immune system in relation to exposure to lead, we administered CaEDTA by intravenous injection for 1 hr three times (three consecutive days) a week to two male lead workers. They had been engaged in recycling lead for 31 and 22 years, aged 61 and 53 years (workers 1 and 2), respectively. Before the treatment of CaEDTA, their blood lead concentrations (PbB) were 81 and 68 micrograms/dl, respectively. The administration of CaEDTA had been carried out to worker 1 for 10 weeks and to worker 2 for 6 weeks. A significant decrease in PbB between before and after three-times CaEDTA injection was found in both workers. Significant increases in IgG, IgA, IgM, CD8+, and CD57+ cells were found in worker 1. A significant increase in IgD was found in worker 2. During the study period, IgG in worker 1 and CD4+ cells in worker 2 were gradually increasing. There was a significant negative correlation between IgG and PbB in worker 1. It is suggested that the immunological function such as antibody formation in lead workers might be improved by CaEDTA injection.

Luminescence in Sulfides: A Rich History and a Bright Future

PubMed Central

Smet, Philippe F.; Moreels, Iwan; Hens, Zeger; Poelman, Dirk

2010-01-01

Sulfide-based luminescent materials have attracted a lot of attention for a wide range of photo-, cathodo- and electroluminescent applications. Upon doping with Ce3+ and Eu2+, the luminescence can be varied over the entire visible region by appropriately choosing the composition of the sulfide host. Main application areas are flat panel displays based on thin film electroluminescence, field emission displays and ZnS-based powder electroluminescence for backlights. For these applications, special attention is given to BaAl2S4:Eu, ZnS:Mn and ZnS:Cu. Recently, sulfide materials have regained interest due to their ability (in contrast to oxide materials) to provide a broad band, Eu2+-based red emission for use as a color conversion material in white-light emitting diodes (LEDs). The potential application of rare-earth doped binary alkaline-earth sulfides, like CaS and SrS, thiogallates, thioaluminates and thiosilicates as conversion phosphors is discussed. Finally, this review concludes with the size-dependent luminescence in intrinsic colloidal quantum dots like PbS and CdS, and with the luminescence in doped nanoparticles.

Study on effect of L-arginine on solubility and dissolution of Zaltoprofen: Preparation and characterization of binary and ternary cyclodextrin inclusion complexes

NASA Astrophysics Data System (ADS)

Sherje, Atul P.; Patel, Forum; Murahari, Manikanta; Suvarna, Vasanti; Patel, Kavitkumar

2018-02-01

The present study demonstrated the binary and ternary complexes of Zaltoprofen (ZPF) with β-CD and HP-β-CD. The products were characterized using solubility, in vitro dissolution, and DSC studies. The mode of interaction of guest and host was revealed through 1H NMR and FT-IR studies. A significant increase was noticed in the stability constant (Kc) and complexation efficiency (CE) of β-CD and HP-β-CD due to addition of L-Arg in ternary complexes. The ternary complexes showed greater increase in solubility and dissolution of ZPF than binary complexes. Thus, ternary system of ZPF could be an innovative approach for its solubility and dissolution enhancement.

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.

Enantiomeric separation of the antiuremic drug colchicine by electrokinetic chromatography. Method development and quantitative analysis.

PubMed

Menéndez-López, Nuria; Valimaña-Traverso, Jesús; Castro-Puyana, María; Salgado, Antonio; García, María Ángeles; Marina, María Luisa

2017-05-10

Two analytical methodologies were developed by CE enabling the enantiomeric separation of colchicine, an antiuremic drug commercialized as pure enantiomer. Succinyl-γ-CD and Sulfated-γ-CD were selected as chiral selectors after a screening with different anionic CDs. Under the optimized conditions, chiral resolutions of 5.6 in 12min and 3.2 in 8min were obtained for colchicine with Succinyl-γ-CD and Sulfated-γ-CD, respectively. An opposite enantiomeric migration order was observed with these two CDs being S-colchicine the first-migrating enantiomer with Succinyl-γ-CD and the second-migrating enantiomer with Sulfated-γ-CD. H NMR experiments showed a 1:1 stoichiometry for the enantiomer-CD complexes in both cases. However, the apparent and averaged equilibrium constants for the enantiomer-CD complexes could be calculated only for Succinyl-γ-CD. The developed methods were applied to the analysis of pharmaceutical formulations but only the use of Succinyl-γ-CD enabled to detect a 0.1% of enantiomeric impurity in colchicine formulations. Copyright © 2017 Elsevier B.V. All rights reserved.

Coupling of non-aqueous electrokinetic chromatography using cationic cyclodextrins with electrospray ionization mass spectrometry.

PubMed

Mol, Roelof; de Jong, Gerhardus J; Somsen, Govert W

2008-01-01

Non-aqueous electrokinetic chromatography (NAEKC) using cationic cyclodextrins (CDs) was coupled to electrospray ionization mass spectrometry (ESI-MS). A methanolic background electrolyte (BGE) was used which contained the hydrochloride salts of the single-isomer derivative cyclodextrins 6-monodeoxy-6-mono(2-hydroxy)propylamino-beta-cyclodextrin (IPA-beta-CD) or 6-monodeoxy-6-mono(3-hydroxy)propylamino-beta-cyclodextrin (PA-beta-CD). Applying a reversed capillary electrophoresis (CE) polarity (-30 kV), efficient separation of negatively charged compounds was achieved with plate numbers of up to 190,000. PA-beta-CD appeared to be the most suitable for the separation of various acidic drugs while also providing a high chiral selectivity. Analyte detection was achieved by ESI-MS in the negative-ion mode using a sheath-liquid interface. In order to prevent current drops caused by the cathodic electroosmotic flow, a pressure of 15 mbar was applied on the inlet vial during NAEKC/MS analysis. The effect of the cationic CDs on the MS signal intensities of acidic test drugs was thoroughly studied. When a voltage is applied across the CE capillary, the overall mobility of the cationic CDs is towards the inlet vial so that no CD molecules enter the ion source. The chloride counter ions of the CDs, which migrated towards the capillary outlet, were found to cause ionization suppression, although significant analyte signals could still be detected. Depending on the CD concentration in the BGE, limits of detection for acidic drugs were in the 50-400 ng/mL range in full-scan mode.

Sensitivity enhancement of fluorescence detection in CE by coupling and conducting excitation light with tapered optical fiber.

PubMed

Yang, Xiupei; Huo, Feng; Yuan, Hongyan; Zhang, Bo; Xiao, Dan; Choi, Martin M F

2011-01-01

This paper reports the enhancement of sensitivity of detection for in-column fiber optic-induced fluorescence detection system in CE by tapered optical fiber (TOF). Two types of optical fiber, TOF and conventional cylindrical optical fiber (COF), were employed to construct the CE (TOF-CE and COF-CE) and were compared for sensitivity to riboflavin (RF). The fluorescence intensities from a RF sample with excitation light sources and fibers at various coupling angles were investigated. The fluorescence signal from TOF-CE was ca. ten times that of COF-CE. In addition, the detection performance of four excitation light source-fiber configurations including Laser-TOF, Laser-COF, LED-TOF, and LED-COF were compared. The LODs for RF were 0.21, 0.82, 0.80, and 7.5 nM, respectively, for the four excitation light source-fiber configurations. The results demonstrate that the sensitivity obtained by LED-TOF is close to that of Laser-COF. Both Laser-TOF and LED-TOF can greatly improve the sensitivity of detection in CE. TOF has the major attribute of collecting and focusing the excitation light intensity. Thus, the sensitivity obtained by LED-TOF without focusing lens is just same as that of LED-COF with a focusing lens. This demonstrates that the CE system can be further simplified by eliminating the focusing lens for excitation light. LED-TOF-CE and LED-COF-CE system were applied to the separation and determination of RF in real sample (green tea), respectively. The tapered fiber optic-induced fluorescence detection system in CE is an ideal tool for trace analysis. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Self-reported dietary adherence, disease-specific symptoms, and quality of life are associated with healthcare provider follow-up in celiac disease.

PubMed

Hughey, Jacob J; Ray, Bonnie K; Lee, Anne R; Voorhees, Kristin N; Kelly, Ciaran P; Schuppan, Detlef

2017-12-11

The only treatment for celiac disease (CeD) is a lifelong gluten-free diet (GFD). The restrictive nature of the GFD makes adherence a challenge. As an integral part of CeD management, multiple professional organizations recommend regular follow-up with a healthcare provider (HCP). Many CeD patients also participate in patient advocacy groups (PAGs) for education and support. Previous work found that follow-up of CeD patients is highly variable. Here we investigated the self-reported factors associated with HCP follow-up among individuals diagnosed with CeD who participate in a PAG. We conducted a survey of members of Beyond Celiac (a PAG), collecting responses from 1832 U.S. adults ages 19-65 who reported having CeD. The survey queried HCP follow-up related to CeD and included validated instruments for dietary adherence (CDAT), disease-specific symptoms (CSI), and quality of life (CD-QOL). Overall, 27% of respondents diagnosed with CeD at least five years ago reported that they had not visited an HCP about CeD in the last five years. The most frequent reason for not visiting an HCP was "doing fine on my own" (47.6%). Using multiple logistic regression, we identified significant associations between whether a respondent reported visiting an HCP about CeD in the last five years and the scores for all three validated instruments. In particular, as disease-specific symptoms and quality of life worsened, the probability of having visited an HCP increased. Conversely, as dietary adherence worsened, the probability decreased. Our results suggest that many individuals with CeD manage their disease without ongoing support from an HCP. Our results thus emphasize the need for greater access to high quality CeD care, and highlight an opportunity for PAGs to bring together patients and HCPs to improve management of CeD.

A Coral-based Reconstruction of Interannual Climate Variability at Vanuatu during the Medieval Climate Anomaly (950-1250 CE)

NASA Astrophysics Data System (ADS)

Lawman, A. E.; Quinn, T. M.; Partin, J. W.; Taylor, F. W.; Thirumalai, K.; WU, C. C.; Shen, C. C.

2016-12-01

The Medieval Climate Anomaly (MCA: 950-1250 CE) is identified as a period during the last 2 millennia with Northern Hemisphere surface temperatures similar to the present. However, our understanding of tropical climate variability during the MCA is poorly constrained due to a lack of proxy records. We investigate the El Niño-Southern Oscillation (ENSO), the leading mode of global interannual variability, during the MCA using geochemical records developed from well preserved fossilized corals from the tropical southwest Pacific (Tasmaloum, Vanuatu; 15° 37' S, 166° 54.5' E). We use paired coral Sr/Ca and δ18O measurements to reconstruct sea surface temperature (SST) and the δ18O of seawater (a proxy for salinity) variability associated with ENSO. We present Sr/Ca and δ18O data from a 1.68-m-long Porites lutea coral head collected from Tasmaloum, Vanuatu. An absolute U/Th date of 1127.1 ± 2.7 CE indicates that the selected coral lived during the MCA. Preliminary assessment of >65 years of monthly resolved Sr/Ca data yields a mean value of 8.937 ± 0.120 mmol/mol (2σ, n = 757), and an average seasonal cycle of 0.156 ± 0.009 mmol/mol or 2.7 ± 0.1°C based on modern Sr/Ca-SST calibrations. We find that the magnitude and variability of the SST seasonal cycle is comparable to gridded and in situ SST datasets for Vanuatu as well as a published, modern 165 year-long coral record from Sabine Bank, Vanuatu, located 90 km to the SW of Tasmaloum. Applying a 2-8 year band pass filter to the Sr/Ca time series, we identify 8 El Niño and 3 La Niña events based on Sr/Ca (SST) anomalies. Preliminary assessment of >45 years of paired δ18O measurements yields a mean value of -4.67 ± 0.43‰ (2σ, n = 373). We also identify ENSO activity in the 2-8 year band pass filtered data. We expect to develop a 120-year record of paired coral Sr/Ca and δ18O measurements when data acquisition is complete, which will be used to investigate the frequency and magnitude of ENSO events during the MCA.

Correlation between Lymphocyte CD4 Count, Treatment Duration, Opportunistic Infection and Cognitive Function in Human Immunodeficiency Virus-Acquired Immunodeficiency Syndrome (HIV-AIDS) Patients.

PubMed

Fitri, Fasihah Irfani; Rambe, Aldy Safruddin; Fitri, Aida

2018-04-15

Human immunodeficiency virus (HIV) infection is an epidemic worldwide, despite the marked benefits of antiretroviral therapy (ARV) in reducing severe HIV-associated dementia. A milder form of neurocognitive disorders are still prevalent and remain a challenge. This study aimed to determine the correlation between plasma cluster of differentiation 4 (CD4) lymphocyte, duration of ARV treatment, opportunistic infections, and cognitive function in HIV-AIDS patients. A cross-sectional study involving 85 HIV-AIDS patients was conducted at Adam Malik General Hospital Medan, Indonesia. All subjects were subjected to physical, neurologic examination and Montreal Cognitive Assessment-Indonesian Version (MoCA-INA) to assess cognitive function and measurement of lymphocyte CD4 counts. Out of the 85 subjects evaluated, the proportion concerning sexes include 52 males (61.2 %) and 33 females (38.8%). The mean age was 38.53 ± 9.77 years old. There was a significant correlation between CD4 lymphocyte counts and MoCA-INA score (r = 0.271, p = 0.012), but there was no significant correlation between duration of ARV treatment and MoCA-INA score. There was also no difference in MoCA-INA score based on the presence of opportunistic infection. Lymphocyte CD4 count was independently correlated with cognitive function in HIV-AIDS patients.

Genetics Home Reference: spondylocarpotarsal synostosis syndrome

MedlinePlus

... active (expressed) in the cell membranes of cartilage-forming cells (chondrocytes). Cartilage is a tough, flexible tissue ... D, Shapiro SS, Takafuta T, Aftimos S, Kim CA, Firth H, Steiner CE, Cormier-Daire V, Superti-Furga A, ...

Cadmium supplement triggers endoplasmic reticulum stress response and cytotoxicity in primary chicken hepatocytes.

PubMed

Shao, Cheng-Cheng; Li, Nan; Zhang, Zi-Wei; Su, Jian; Li, Shu; Li, Jin-Long; Xu, Shi-Wen

2014-08-01

Cadmium (Cd), a potent hepatotoxin, has been reported to induce endoplasmic reticulum (ER) stress in various cell types. However, whether such effect exists in bird is still unclear. To delineate the effects of Cd exposure on ER stress response, we examined the expression of 78-kDa glucose-regulated protein (GRP78) and alteration in calcium homeostasis in primary chicken hepatocytes treated with 2-22 µM Cd for 24 h. A significant decrease of cell viability was observed in chicken hepatocytes following Cd administration. In cells treated with Cd, GRP78 protein levels increased in a dose-dependent manner. In addition, GRP78 and GRP94mRNA levels were elevated in response to Cd exposure. The increase of the intracellular Ca(2+) concentration in chicken hepatocytes was found during Cd exposure. Cd significantly decreased the CaM mRNA levels in hepatocytes. These results show that Cd regulates the expression of GRP78 and calcium homeostasis in chicken hepatocytes, suggesting that ER stress induced by Cd plays an important role in the mechanisms of Cd cytotoxicity to the bird hepatocytes. Copyright © 2014 Elsevier Inc. All rights reserved.

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.

Heteroepitaxial growth of cadmium carbonate at dolomite and calcite surfaces: Mechanisms and rates

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

Callagon, Erika Blanca R.; Lee, Sang Soo; Eng, Peter J.

Here, the systematic variation of rates and the mechanism of cadmium uptake on the (104) surface of dolomite (CaMg(CO 3) 2) were investigated using in situ and ex situ atomic force microscopy (AFM), ex situ specular X-ray reflectivity (XR), and ex situ X-ray fluorescence (XRF). Selected experiments were performed on the calcite (CaCO 3) (104) surface for comparison. Aqueous solutions of CdCl 2, CaCl 2, and NaHCO 3, undersaturated with respect to calcite and supersaturated with respect to otavite (CdCO 3) and the (Cd xCa 1-x)CO 3 solid solution, were reacted with dolomite surfaces for minutes to days. Calcite substratesmore » were reacted with solutions containing 1-50 μM CdCl 2, and with no added Ca or CO 3. Thin carbonate films following the Stranski-Krastanov growth mode were observed on both substrates. Specular XR and XRF revealed the formation of nm-thick Cd-rich carbonate films that were structurally ordered with respect to the dolomite (104) plane. Epitaxial films adopted the calcite crystal structure with a d 104- spacing (3.00 Å) larger than those of pure dolomite (2.88 Å) and otavite (2.95 Å) indicating either a solid solution with x approximate to 0.5, or a strained Cd-rich carbonate with a composition near that of otavite. The growth rate r of this phase increases with the initial supersaturation of the solution with respect to the solid solution, beta max, and follows the empirical relationship, as determined from XRF measurements, given by: r = 10 -4.88 ± 0.42 (β 2.29 ± 0.24 max - 1), (in units of atoms of Cd/Å 2/h).The morphology of the overgrowth also varied with β max, as exemplified by AFM observations. Growth at step edges occurred over the entire β max range considered, and additional growth features including 3 Å high monolayer islands and ~ 25 Å high tall islands were observed when log β max > 1. On calcite, in situ XR indicated that this phase is similar to the Cd-rich overgrowth formed on dolomite and images obtained from X-ray reflection interface microscopy (XRIM) reveal the existence of laterally variable Cd-rich domains.« less

Heteroepitaxial growth of cadmium carbonate at dolomite and calcite surfaces: Mechanisms and rates

DOE PAGES

Callagon, Erika Blanca R.; Lee, Sang Soo; Eng, Peter J.; ...

2016-12-10

Here, the systematic variation of rates and the mechanism of cadmium uptake on the (104) surface of dolomite (CaMg(CO 3) 2) were investigated using in situ and ex situ atomic force microscopy (AFM), ex situ specular X-ray reflectivity (XR), and ex situ X-ray fluorescence (XRF). Selected experiments were performed on the calcite (CaCO 3) (104) surface for comparison. Aqueous solutions of CdCl 2, CaCl 2, and NaHCO 3, undersaturated with respect to calcite and supersaturated with respect to otavite (CdCO 3) and the (Cd xCa 1-x)CO 3 solid solution, were reacted with dolomite surfaces for minutes to days. Calcite substratesmore » were reacted with solutions containing 1-50 μM CdCl 2, and with no added Ca or CO 3. Thin carbonate films following the Stranski-Krastanov growth mode were observed on both substrates. Specular XR and XRF revealed the formation of nm-thick Cd-rich carbonate films that were structurally ordered with respect to the dolomite (104) plane. Epitaxial films adopted the calcite crystal structure with a d 104- spacing (3.00 Å) larger than those of pure dolomite (2.88 Å) and otavite (2.95 Å) indicating either a solid solution with x approximate to 0.5, or a strained Cd-rich carbonate with a composition near that of otavite. The growth rate r of this phase increases with the initial supersaturation of the solution with respect to the solid solution, beta max, and follows the empirical relationship, as determined from XRF measurements, given by: r = 10 -4.88 ± 0.42 (β 2.29 ± 0.24 max - 1), (in units of atoms of Cd/Å 2/h).The morphology of the overgrowth also varied with β max, as exemplified by AFM observations. Growth at step edges occurred over the entire β max range considered, and additional growth features including 3 Å high monolayer islands and ~ 25 Å high tall islands were observed when log β max > 1. On calcite, in situ XR indicated that this phase is similar to the Cd-rich overgrowth formed on dolomite and images obtained from X-ray reflection interface microscopy (XRIM) reveal the existence of laterally variable Cd-rich domains.« less

Functional properties of cells obtained from human cord blood CD34+ stem cells and mouse cardiac myocytes in coculture.

PubMed

Orlandi, Alessia; Pagani, Francesca; Avitabile, Daniele; Bonanno, Giuseppina; Scambia, Giovanni; Vigna, Elisa; Grassi, Francesca; Eusebi, Fabrizio; Fucile, Sergio; Pesce, Maurizio; Capogrossi, Maurizio C

2008-04-01

Prior in vitro studies suggested that different types of hematopoietic stem cells may differentiate into cardiomyocytes. The present work examined whether human CD34(+) cells from the human umbilical cord blood (hUCB), cocultured with neonatal mouse cardiomyocytes, acquire the functional properties of myocardial cells and express human cardiac genes. hUCB CD34(+) cells were cocultured onto cardiomyocytes following an infection with a lentivirus-encoding enhanced green fluorescent protein (EGFP). After 7 days, mononucleated EGFP(+) cells were tested for their electrophysiological features by patch clamp and for cytosolic [Ca(2+)] ([Ca(2+)](i)) homeostasis by [Ca(2+)](i) imaging of X-rhod1-loaded cells. Human Nkx2.5 and GATA-4 expression was examined in cocultured cell populations by real-time RT-PCR. EGFP(+) cells were connected to surrounding cells by gap junctions, acquired electrophysiological properties similar to those of cardiomyocytes, and showed action potential-associated [Ca(2+)](i) transients. These cells also exhibited spontaneous sarcoplasmic reticulum [Ca(2+)](i) oscillations and the associated membrane potential depolarization. However, RT-PCR of both cell populations showed no upregulation of human-specific cardiac genes. In conclusion, under our experimental conditions, hUCB CD34(+) cells cocultured with murine cardiomyocytes formed cells that exhibited excitation-contraction coupling features similar to those of cardiomyocytes. However, the expression of human-specific cardiac genes was undetectable by RT-PCR.

Diverse solid tumors expressing a restricted epitope of L1-CAM can be targeted by chimeric antigen receptor redirected T lymphocytes.

PubMed

Hong, Hao; Stastny, Michael; Brown, Christine; Chang, Wen-Chung; Ostberg, Julie R; Forman, Stephen J; Jensen, Michael C

2014-01-01

Adhesion molecule L1-CAM (CD171) was originally reported to be overexpressed on neuroblastoma and to play an important role during tumor progression. More recently, it has been shown to be overexpressed on many other solid tumors such as melanoma and carcinomas of the cervix, ovary, bladder, and others. Thus, there has been a growing interest in using this cell-surface molecule as a target for both antibody-based and cellular-based therapy-our group has previously examined the clinical utility of chimeric antigen receptor (CAR)-redirected cytolytic T cells that specifically target the CE7 epitope of L1-CAM on neuroblastoma patients. Here, we sought to determine whether this CE7 epitope is present on other recently identified L1-CAM tumors and whether it too can be targeted by CAR T cells. Our studies demonstrate that a diverse array of human tumor cell lines and primary solid tumors (ovarian, lung, and renal carcinoma, glioblastoma and neuroblastoma) do express the CE7 epitope and can efficiently stimulate CE7-specific CAR-redirected (CE7R) T-cell lytic activity and secretion of proinflamatory cytokines. L1-CAM was also detected on a limited number of normal tissues; however, L1-CAM expressed on normal human monocytes was not bound by the CE7 mAb nor was it targeted by CE7R T cells, suggesting that the CE7 epitope is more tumor restricted and not expressed on all L1-CAM tissues. Overall, the CE7 epitope of L1-CAM on a variety of tumors may be amenable to targeting by CE7R T cells, making it a promising target for adoptive immunotherapy.

AN IMPROVED UNDERSTANDING OF SOIL CD RISK TO HUMANS AND LOW COST METHODS TO PHYTOEXTRACT CD FROM CONTAMINATED SOILS TO PREVENT SOIL CD RISKS

EPA Science Inventory

We have described a new paradigm for human risk from soil Cd that reflects many years of agronomic, nutritional and toxicological research. This new model for soil Cd risk reflects the ability of rice to accumulate soil Cd in grain while excluding Fe, Zn and Ca even though the s...

Combined evaluation of a panel of protein and miRNA serum-exosome biomarkers for pancreatic cancer diagnosis increases sensitivity and specificity.

PubMed

Madhavan, Bindhu; Yue, Shijing; Galli, Uwe; Rana, Sanyukta; Gross, Wolfgang; Müller, Miryam; Giese, Nathalia A; Kalthoff, Holger; Becker, Thomas; Büchler, Markus W; Zöller, Margot

2015-06-01

Late diagnosis contributes to pancreatic cancer (PaCa) dismal prognosis, urging for reliable, early detection. Serum-exosome protein and/or miRNA markers might be suitable candidates, which we controlled for patients with PaCa. Protein markers were selected according to expression in exosomes of PaCa cell line culture supernatants, but not healthy donors' serum-exosomes. miRNA was selected according to abundant recovery in microarrays of patients with PaCa, but not healthy donors' serum-exosomes and exosome-depleted serum. According to these preselections, serum-exosomes were tested by flow cytometry for the PaCa-initiating cell (PaCIC) markers CD44v6, Tspan8, EpCAM, MET and CD104. Serum-exosomes and exosome-depleted serum was tested for miR-1246, miR-4644, miR-3976 and miR-4306 recovery by qRT-PCR. The majority (95%) of patients with PaCa (131) and patients with nonPa-malignancies reacted with a panel of anti-CD44v6, -Tspan8, -EpCAM and -CD104. Serum-exosomes of healthy donors' and patients with nonmalignant diseases were not reactive. Recovery was tumor grading and staging independent including early stages. The selected miR-1246, miR-4644, miR-3976 and miR-4306 were significantly upregulated in 83% of PaCa serum-exosomes, but rarely in control groups. These miRNA were also elevated in exosome-depleted serum of patients with PaCa, but at a low level. Concomitant evaluation of PaCIC and miRNA serum-exosome marker panels significantly improved sensitivity (1.00, CI: 0.95-1) with a specificity of 0.80 (CI: 0.67-0.90) for PaCa versus all others groups and of 0.93 (CI: 0.81-0.98) excluding nonPa-malignancies. Thus, the concomitant evaluation of PaCIC and PaCa-related miRNA marker panels awaits retrospective analyses of larger cohorts, as it should allow for a highly sensitive, minimally-invasive PaCa diagnostics. © 2014 UICC.

Surface complexation modeling of Cd(II) sorption to montmorillonite, bacteria, and their composite

NASA Astrophysics Data System (ADS)

Wang, Ning; Du, Huihui; Huang, Qiaoyun; Cai, Peng; Rong, Xingmin; Feng, Xionghan; Chen, Wenli

2016-10-01

Surface complexation modeling (SCM) has emerged as a powerful tool for simulating heavy metal adsorption processes on the surface of soil solid components under different geochemical conditions. The component additivity (CA) approach is one of the strategies that have been widely used in multicomponent systems. In this study, potentiometric titration, isothermal adsorption, zeta potential measurement, and extended X-ray absorption fine-structure (EXAFS) spectra analysis were conducted to investigate Cd adsorption on 2 : 1 clay mineral montmorillonite, on Gram-positive bacteria Bacillus subtilis, and their mineral-organic composite. We developed constant capacitance models of Cd adsorption on montmorillonite, bacterial cells, and mineral-organic composite. The adsorption behavior of Cd on the surface of the composite was well explained by CA-SCM. Some deviations were observed from the model simulations at pH < 5, where the values predicted by the model were lower than the experimental results. The Cd complexes of X2Cd, SOCd+, R-COOCd+, and R-POCd+ were the predominant species on the composite surface over the pH range of 3 to 8. The distribution ratio of the adsorbed Cd between montmorillonite and bacterial fractions in the composite as predicted by CA-SCM closely coincided with the estimated value of EXAFS at pH 6. The model could be useful for the prediction of heavy metal distribution at the interface of multicomponents and their risk evaluation in soils and associated environments.

Comparative study of the complex forming ability and enantioselectivity of cyclodextrin polymers by CE and 1H NMR.

PubMed

Danel, Cécile; Azaroual, Nathalie; Chavaria, Cédric; Odou, Pascal; Martel, Bernard; Vaccher, Claude

2013-02-15

The interactions between nine drugs (baclofen, bupivacaine, chlorpheniramine, ketoconazole, paliperidone, promethazine, propranolol, risperidone and verapamil) and six cyclodextrins (α-CD, β-CD, γ-CD, HP-β-CD, HP-γ-CD and Me-β-CD) or six polymers of cyclodextrins (polyα-CD, polyβ-CD, polyγ-CD, polyHP-β-CD, polyHP-γ-CD and polyMe-β-CD) were studied by affinity capillary electrophoresis and/or (1)H NMR at pH 2.5. An exhaustive qualitative study was performed through the determination of the retardation factor. Then, four compounds and both β-CD and polyβ-CD were selected for the quantitative study of the interactions at pH 2.5 and 7.0. By comparing the results obtained with the β-CD and polyβ-CD, it appears that the apparent binding constants are up to five times higher with the polymer. The 2D-NMR results seem to indicate that the structure of the polymeric network favours the inclusion of the guest in the hydrophobic cavity of the CD units. Moreover, the poly-CDs have shown very high enantioselective abilities at both pH. Copyright © 2012 Elsevier Ltd. All rights reserved.

Functionalized inorganic membranes for gas separation

DOEpatents

Ku, Anthony Yu-Chung [Rexford, NY; Ruud, James Anthony [Delmar, NY; Molaison, Jennifer Lynn [Marietta, GA; Schick, Louis Andrew ,; Ramaswamy, Vidya [Niskayuna, NY

2008-07-08

A porous membrane for separation of carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity. The porous membrane comprises a porous support layer comprising alumina, silica, zirconia or stabilized zirconia; a porous separation layer comprising alumina, silica, zirconia or stabilized zirconia, and a functional layer comprising a ceramic oxide contactable with the fluid stream to preferentially transport carbon dioxide. In particular, the functional layer may be MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3 or a mixture thereof; wherein A is Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; and A.sup.3 is Sr or Ba.

UV-vis spectroscopic studies of CaF2 photo-thermo-refractive glass

NASA Astrophysics Data System (ADS)

Stoica, Martina; Herrmann, Andreas; Hein, Joachim; Rüssel, Christian

2016-12-01

A photo-thermo-refractive glass based on the system Na2O/K2O/CaO/CaF2/Al2O3/ZnO/SiO2 doped with Ag2O, CeO2, SnO2, Sb2O3 and KBr was investigated. This glass undergoes a permanent refractive index change after UV irradiation and subsequent two step heat treatment at temperatures above Tg. This is due to the formation of Ag metal clusters which act as nucleation centers for CaF2 crystallization. Oxidation of Ce3+ by UV light is the initial reaction and acts as photosensitizer in the glass. The UV-vis absorption spectra during this photo-induced crystallization process were measured. The spectral components that form the absorption spectra of cerium were studied in detail by a band separation with Gaussian functions. Deconvolution of the cerium absorption bands shows an envelope of five spectral components for the trivalent cerium due to the 4f-5d transitions and two spectral components for the tetravalent cerium caused by charge transfer transitions. The effect of different dopants and melting conditions on the photo-thermal process were studied to investigate the influence of glass technology on the photoprocess.

Assessment of Pb, Cd and Hg soil contamination and its potential to cause cytotoxic and genotoxic effects in human cell lines (CaCo-2 and HaCaT).

PubMed

Sljivic Husejnovic, Maida; Bergant, Martina; Jankovic, Sasa; Zizek, Suzana; Smajlovic, Aida; Softic, Adaleta; Music, Omer; Antonijevic, Biljana

2018-01-23

Soil contamination by heavy metals is a serious global environmental problem, especially for developing countries. A large number of industrial plants, which continually pollute the environment, characterize Tuzla Canton, Bosnia and Herzegovina. The aim of this study was to assess the level of soil pollution by heavy metals and to estimate cytotoxicity and genotoxicity of soil leachates from this area. Lead (Pb), cadmium (Cd) and mercury (Hg) were analyzed by ICP-AES and AAS. Soil contamination was assessed using contamination factor, degree of contamination, geoaccumulation index and pollution load index. To determine the connection of variables and understanding their origin in soils, principal component analysis (PCA) and cluster analysis (CA) were used. The results indicate that Cd and Hg originated from natural and anthropogenic activities, while Pb is of anthropogenic origin. For toxicity evaluation, CaCo-2 and HaCaT cells were used. PrestoBlue assay was used for cytotoxicity testing, and γH2A.X for genotoxicity evaluation. Concerning cytotoxicity, Cd and Hg had a positive correlation with cytotoxicity in HaCaT cells, but only Hg induced cytotoxicity in CaCo-2 cells. We also demonstrate that soil leachates contaminated by heavy metals can induce genotoxicity in both used cell lines. According to these results, combining bioassays with standard physicochemical analysis can be useful for evaluating environmental and health risks more accurately. These results are important for developing proper management strategies to decrease pollution. This is one of the first studies from this area and an important indication of soil quality in Southeast Europe.

Charge and orbital orders and structural instability in high-pressure quadruple perovskite CeCuMn6O12

NASA Astrophysics Data System (ADS)

Zhang, Lei; Matsushita, Yoshitaka; Katsuya, Yoshio; Tanaka, Masahiko; Yamaura, Kazunari; Belik, Alexei A.

2018-02-01

We prepared a quadruple perovskite CeCuMn6O12 under high-pressure and high-temperature conditions at 6 GPa and about 1670 K and investigated its structural, magnetic and transport properties. CeCuMn6O12 crystallizes in space group Im-3 above T CO  =  297 K below this temperature, it adopts space group R-3 with the 1:3 (Mn4+:Mn3+) charge and orbital orders. Unusual compressed Mn3+O6 octahedra are realized in CeCuMn6O12 similar to CaMn7O12 with the  -Q 3 Jahn-Teller distortion mode. Below about 90 K, structural instability takes place with phase separation and the appearance of competing phases; and below 70 K, two R-3 phases coexist. CeCuMn6O12 exhibits a ferromagnetic-like transition below T C  =  140 K, and it is a semiconductor with the magnetoresistance reaching about  -40% at 140 K and 70 kOe. We argued that the valence of Ce is  +3 in CeCuMn6O12 with the Ce3+(C{{u}2+}Mn23+ )(Mn33+M{{n}4+} )O12 charge distribution in the charge-ordered R-3 phase and Ce3+(C{{u}2+}Mn23+ )(Mn43.25+ )O12 in the charge-disordered Im-3 phase.

Post-depositional redistribution processes and their effects on middle rare earth element precipitation and the cerium anomaly in sediments in the South Korea Plateau, East Sea

NASA Astrophysics Data System (ADS)

Kang, Jeongwon; Jeong, Kap-Sik; Cho, Jin Hyung; Lee, Jun Ho; Jang, Seok; Kim, Seong Ryul

2014-03-01

We sampled two box-core sediments from the slope of the eastern South Korea Plateau (SKP) in the East Sea (Sea of Japan) at water depths of 1400 and 1700 m. Two chemical fractions of extractable (hydroxylamine/acetic acid) and residual rare earth elements (REEs) together with Al, Ca, Fe, Mg, Mn, P, S, As, Mo, and U were analyzed to assess the post-depositional redistribution of REEs. Extractable Fe and Mn are noticeably abundant in the oxic topmost sediment layer (<3 cm). However, some trace elements (e.g., S, As, Mo, U) are more abundant at depth, where redox conditions are different. Analysis of upper continental crust (UCC)-normalized (La/Gd)UCC, (La/Yb)UCC, and (Ce/Ce*)UCC revealed that the extractable REE is characterized by middle REE (MREE) enrichment and a positive cerium (Ce) anomaly, different from the case of the residual fraction which shows slight enrichment in light REEs (LREEs) with no Ce anomaly. The extractable MREEs seem to have been incorporated into high-Mg calcite during reductive dissolution of Fe oxyhydroxides. In the top sediment layer, the positive Ce anomaly is attributed to Ce oxide, which can be mobilized in deeper oxygen-poor environments and redistributed in the sediment column. In addition, differential concentrations of Ce and other LREEs in pore water appear to result in variable (Ce/Ce*)UCC ratios in the extractable fraction at depth.

Natural seaweed waste as sorbent for heavy metal removal from solution.

PubMed

Ahmady-Asbchin, Salman; Andres, Yves; Gerente, Claire; Le Cloirec, Pierre

2009-06-01

Biosorption is a suitable heavy metal remediation technique for the treatment of aqueous effluents of large volume and low pollutant concentration. However, today industrial applications need the selection of efficient low-cost biosorbents. The aim of this work is to investigate brown alga such as Fucus serratus (FS) as a low-cost biosorbent, for the fixation of metallic ions, namely Cu(2+), Zn(2+), Pb(2+), Ni(2+), Cd(2+) and Ce(3+), in a batch reactor. Biosorption kinetics and isotherms have been performed at pH 5.5. For all of the studied metallic ions, the equilibrium time is about 450 min and a tendency based on the initial sorption rate has been established: Ce(3+) > Zn(2+) > Ni(2+) > Cu(2+) > Cd(2+) > Pb(2+). The adsorption equilibrium data are well described by the Langmuir equation. The sequence of the maximum adsorption capacity is Pb(2+) approximately equal Cu(2+) > Ce(3+) approximately equal Ni(2+) > Cd(2+) > Zn(2+) and values are ranged between 1.78 and 0.71 mmol g(-1). These results indicate that the FS biomass is a suitable biosorbent for the removal of heavy metals from wastewater and can be tested in a dynamic process. The selected pilot process involves a hybrid membrane process: a continuous stirred tank reactor is coupled with a microfiltration immersed membrane, in order to confine the FS particles. A mass balance model is used to describe the adsorption process and the breakthrough curves are correctly modelled. Based on these results, it is demonstrated that FS is an interesting biomaterial for the treatment of water contaminated heavy metals.

Dexamethasone attenuates echinococcosis-induced allergic reactions via regulatory T cells in mice.

PubMed

Zhang, Qin; Ye, Jianrong; Zheng, Hong

2016-03-11

Cystic echinococcosis (CE), caused by infection with Echinococcus granulosus larvae, is a potentially life-threatening disease in humans. Anaphylactic shock caused by CE is very dangerous, and is highly prevalent during surgery. Dexamethasone (DEX) is used clinically before operations to prevent allergic reactions; Regulatory T cells (Treg cells) are believed to be associated with negative immune response, which play an important role in alleviating allergic reactions. However, the association of Treg cells with DEX remains unknown. In this study, C57BL/6 mice were divided into uninfected group, untreated group and DEX group which were inoculated with protoscoleces from E. granulosus and sensitized using a cyst fluid suspension to induce anaphylactic shock. In addition, the mice in DEX group were treated with 10 mg/kg DEX by intraperitoneal injection 30 min before being sensitized. It was found that 93.75 % of all sensitized mice experienced allergic symptoms. The levels of IgE, IgE/IgG, and IgE/IgG1 were significantly higher in both untreated group and DEX group. The proportion of CD4 + CD25 + FOXP3 + Treg cells relative to CD4+ Treg cells, and the levels of interleukin-10 (IL-10) and tumor growth factor-β (TGF-β1) were significantly higher in DEX group. The level of IL-13 was significantly higher in the sensitized mice than in the other groups. These cells may play a key role in alleviating the immune response in CE-induced anaphylactic shock. The protective effect of DEX may be due to Treg cell upregulating IL-10 and TGF-β1 levels, and inhibiting helper T cell 2 cytokines.

Effects of membrane cholesterol manipulation on excitation-contraction coupling in skeletal muscle of the toad

PubMed Central

Launikonis, Bradley S; Stephenson, D George

2001-01-01

Single mechanically skinned fibres and intact bundles of fibres from the twitch region of the iliofibularis muscle of cane toads were used to investigate the effects of membrane cholesterol manipulation on excitation-contraction (E-C) coupling. The cholesterol content of membranes was manipulated with methyl-β-cyclodextrin (MβCD). In mechanically skinned fibres, depletion of membrane cholesterol with MβCD caused a dose- and time-dependent decrease in transverse tubular (t)-system depolarization-induced force responses (TSDIFRs). TSDIFRs were completely abolished within 2 min in the presence of 10 mm MβCD but were not affected after 2 min in the presence of a 10 mm MβCD-1 mm cholesterol complex. There was a very steep dependence between the change in TSDIFRs and the MβCD : cholesterol ratio at 10 mm MβCD, indicating that the inhibitory effect of MβCD was due to membrane cholesterol depletion and not to a pharmacological effect of the agent. Tetanic responses in bundles of intact fibres were abolished after 3-4 h in the presence of 10 mm MβCD. The duration of TSDIFRs increased markedly soon (< 2 min) after application of 10 mm MβCD and 10 mm MβCD-cholesterol complexes, but the Ca2+ activation properties of the contractile apparatus were minimally affected by 10 mm MβCD. The Ca2+ handling abilities of the sarcoplasmic reticulum appeared to be modified after 10 min exposure to 10 mm MβCD. Confocal laser scanning microscopy revealed that the integrity of the t-system was not compromised by either intra- or extracellular application of 10 mm MβCD and that a large [Ca2+] gradient was maintained across the t-system. Membrane cholesterol depletion caused rapid depolarization of the polarized t-system as shown independently by spontaneous TSDIFRs induced by MβCD and by changes in the fluorescence intensity of an anionic potentiometric dye (DiBAC4(3)) in the presence of MβCD. This rapid depolarization of the t-system by cholesterol depletion was not prevented by blocking the Na+ channels with TTX (10 μm) or the L-type Ca2+ channels with Co2+ (5 mm). The results demonstrate that cholesterol is important for maintaining the functional integrity of the t-system and sarcoplasmic reticulum, probably by having specific effects on different membrane proteins that may be directly or indirectly involved in E-C coupling. PMID:11432993

Effects of Pb plus Cd mixtures on toxicity, and internal electrolyte and osmotic balance in the rainbow trout (Oncorhynchus mykiss).

PubMed

Clemow, Yvonne H; Wilkie, Michael P

2015-04-01

The physiological and toxicological effects of Cd and Pb have been thoroughly studied, but relatively little work has been done to determine how mixtures of these metals affect fishes in soft (<100 μmol L(-1)Ca(2+)) slightly acidic (pH ∼6) waters typical of many lakes in the Canadian Shield and other regions. Recently, it has been suggested that acute exposure to Cd plus Pb mixtures (3h) had greater than additive effects on both Ca(2+) and Na(+) influx, which could potentially exacerbate disturbances to ion balance and result in greater toxicity in rainbow trout (Oncorhynchus mykiss). The goal of the present study was to test this hypothesis by assessing the physiological and toxicological effects of Cd plus Pb mixtures over longer time periods (3-5 days), but at relatively low, more environmentally relevant concentrations of these metals. Accordingly, toxicity and measurements of blood acid-base regulation (PaO2, pHa), hematology (Ht, Hb, MCHC, and Protein), ionic composition (body ions and plasma Ca(2+), Na(+), Cl(-), osmolality), unidirectional Na(+) fluxes and branchial Na(+)/K(+)-ATPase activity were measured in rainbow trout exposed to Cd plus Pb mixtures. Experiments on rainbow trout, implanted with dorsal aortic catheters for repetitive blood sampling, demonstrated that exposure to Pb alone (26 nmol PbL(-1)) was less toxic than Cd alone (6 nmol CdL(-1)), which was much less toxic to the fish than a Cd plus Pb mixture (7 nmol CdL(-1) plus 45 nmol PbL(-1)), which led to greater than additive 80% mortality by 5d. Both Cd and Pb inhibited Na(+) influx over 3d exposure to the metals, which was partially offset by decreases in the diffusive efflux (outflux) of Na(+) across the gill. Despite an absence of detectable effects of Pb alone on plasma ion balance, Cd plus Pb mixtures exacerbated Cd-induced reductions in plasma Ca(2+) concentration, and resulted in pronounced reductions in plasma Na(+), Cl(-), and osmolality. No effects on Na(+)/K(+)-ATPase activity were noted following exposure to Cd, Pb or Pb plus Cd mixtures. We conclude that the greater than additive toxicity of Cd plus Pb mixtures observed in the present and previous studies is because these metals not only have common, but also independent binding sites and mechanisms of action, which could exacerbate the pathophysiological effects caused by each metal alone. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of rare earth Ce on the far infrared radiation property of iron ore tailings ceramics

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

Liu, Jie; Institute of Power Source and Ecomaterials Science, Hebei University of Technology, Tianjin 300130; Meng, Junping, E-mail: srlj158@sina.com

2015-06-15

Highlights: • Detailed process proposed for preparation of iron ore tailings ceramics. • Replace natural minerals with iron ore tailings as raw materials for preparing functional ceramics. • Impact mechanism of Ce on far infrared ceramics, as well as its optimum addition amounts can be obtained. • Propose a new perspective on considering the mechanism of far infrared radiation. - Abstract: A kind of far infrared radiation ceramics was prepared by using iron ore tailings, CaCO{sub 3} and SiO{sub 2} as main raw materials, and Ce as additive. The result of Fourier transform infrared spectroscopy showed that the sample exhibitsmore » excellent radiation value of 0.914 when doping 7 wt.% Ce. Ce{sup 4+} dissolved into iron diopside and formed interstitial solid solution with it sintered at 1150 °C. The oxidation of Fe{sup 2+} to Fe{sup 3+} caused by Ce{sup 4+} led to a decrease of crystallite sizes and enhancement of Mg–O and Fe–O vibration in iron diopside, which consequently improved the far infrared radiation properties of iron ore tailings ceramics.« less

The effect of age and gender on 38 chemical element contents in human iliac crest investigated by instrumental neutron activation analysis.

PubMed

Zaichick, Sofia; Zaichick, Vladimir

2010-01-01

To understand the role of major, minor, and trace elements in the etiology of bone diseases including osteoporosis, it is necessary to determine the normal levels and age-related changes of bone chemical elements. The effect of age and gender on 38 chemical element contents in intact iliac crest of 84 apparently healthy 15-55 years old women (n=38) and men (n=46) was investigated by neutron activation analysis. Mean values (M+/-SEM) for mass fraction (on dry weight basis) of Ca, Cl, Co, Fe, K, Mg, Mn, Na, P, Rb, Sr, and Zn for both female and male taken together were Ca - 169+/-3g/kg, Cl - 1490+/-43 mg/kg, Co - 0.0073+/-0.0024 mg/kg, Fe - 177+/-24 mg/kg, K - 1820+/-79 mg/kg, Mg - 1840+/-48 mg/kg, Mn - 0.316+/-0.013 mg/kg, Na - 4970+/-87 mg/kg, P - 79.7+/-1.5 g/kg, Rb - 1.89+/-0.22 mg/kg, Sr - 312+/-15 mg/kg, and Zn - 65.9+/-3.4 mg/kg, respectively. The upper limit of mean contents of Cs, Eu, Hg, Sb, Sc, and Se were Cs < or = 0.09 mg/kg, Eu < or = 0.005 mg/kg, Hg < or = 0.005 mg/kg, Sb < or = 0.004 mg/kg, Sc < or = 0.001 mg/kg, and Se < or = 0.1mg/kg, respectively. In all bone samples the contents of Ag, As, Au, Ba, Br, Cd, Ce, Cr, Gd, Hf, La, Lu, Nd, Sm, Ta, Tb, Th, U, Yb, and Zr were under detection limits. The Ca, Mg, and P contents decrease with age, regardless of gender. Higher Ca, Mg, P, and Sr mass fractions as well as lower Fe content are typical of female iliac crest as compared to those in male bone. Copyright 2009 Elsevier GmbH. All rights reserved.

Late magmatic stage of the zoned Caleu pluton (Central Chile): insights from zircon crystallization conditions

NASA Astrophysics Data System (ADS)

Molina, P. G.; Parada, M.; Gutierrez, F. J.; Chang-Qiang, M.; Jianwei, L.; Yuanyuan, L.

2012-12-01

The Caleu pluton consists of three N-S elongated lithological zones: Gabbro-Diorite Zone (GDZ), Tonalite Zone (TZ) and Granodiorite Zone (GZ); western, middle and eastern portions of the pluton, respectively. The zones are thought to be previously differentiated in a common, isotopically depleted (Sr-Nd), subjacent magma reservoir at a 4 kbar equivalent depth. The emplacement should have occurred at the climax of the Cretaceous rifting. We present preliminary results of U238/Pb206 zircon geochronology; zircon saturation, Tsat(Zrn), and crystallization temperatures (Ti-in-Zrn); as well as relative oxidation states at time of crystallization, based on: (i) the sluggish REE and HFSE subsolidus diffusivities in zircon; (ii) the behavior of Ti4+↔Si4+ and Ce4+↔Zr4+ isovalent replacement, in addition to a constrained TiO2 activity in almost all typical crustal rocks; and (iii) relative oxidation states at time of crystallization, respectively. The latter are obtained by interpolation of the partition coefficients of trivalent (REE) and tetravalent (HFSE) curves in Onuma diagrams for each zircon, and then estimating relative Ce(IV)/Ce(III) ratios. Results obtained from 4 samples (a total of 77 zircon grains) collected from the three mentioned lithological zones indicate U/Pb ages of approximately 99.5 ±1.5 Ma, 96.8 ±0.6 Ma, and 94.4 +2.2 -0.8 Ma; and Ti-in Zrn ranges of ca. 720-870°C, ca. 680-820°C and ca. 750-840°C, for the GDZ, TZ and GZ samples, respectively. On the other hand Tsat(Zrn) of ca. 750-780°C in the TZ, and ca. 830-890°C in the GZ, were obtained. As expected saturation temperatures are similar or higher than Ti-in-Zrn obtained in zircon grains of TZ and GZ, respectively. Cathodoluminiscence images in zircon suggest a magmatic origin, due to absence of complex zoning patterns and fairly well conserved morphologies. Exceptionally the GDZ sample zircons show evidence of inheritance, indicating a xenocrystic and/or antecrystic origin. A relative Ce(IV)/Ce(III) decrease with temperature gives rise to separate trends for each zone, suggesting an independent unbuffered development at time of zircon formation. Taking into account variations in zircon ages, morphologies and crystallization ranges in the collected samples, it is suggested that zircon crystallization took place independent of the magma composition. Furthermore, old inherited zircon grains in the GDZ could be antecrysts, or products of a restricted and not major host rock assimilation, owing to the impossibility of basaltic magmas to saturate zircon crystals, and the isotopically depleted signature. This study is financed by CONICYT-FONDAP grant 15090013, Centro de Excelencia en Geotermia de los Andes (CEGA); and the CONICYT PBCT-PDA07, Programa Bicentenario de Ciencia y Tecnología.

ICP-AES Determination of Mineral Content in Boletus tomentipes Collected from Different Sites of China.

PubMed

Wang, Xue-mei; Zhang, Ji; Li, Tao; Li, Jie-qing; Wang, Yuan-zhong; Liu, Hong-gao

2015-05-01

P, Na, Ca, Cu, Fe, Mg, Zn, As, Cd, Co, Cr and Ni, contents have been examined in caps and stipes of Boletus tomentipes collected from different sites of Yunnan province, southwest China. The elements were determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES) with microwave digestion. P, Ca, Mg, Fe, Zn and Cu were the most abundant amongst elements determined in Boletus tomentipes. The caps were richer in P, Mg, Zn and Cd, and the stipes in Ca, Co and Ni. Cluster analysis showed a difference between Puer (BT7 and BT8) and other places. The PCA explained about 77% of the total variance, and the minerals differentiating these places were P (PC1) together with Ca, Cu, Fe, Mg, As and Ni, Na (PC2) together with Cd, and Zn (PC3). The results of this study imply that element concentrations of a mushroom are mutative when collected from the different bedrock soil geochemistry.

Anthropogenic land use estimates for the Holocene - HYDE 3.2

NASA Astrophysics Data System (ADS)

Klein Goldewijk, Kees; Beusen, Arthur; Doelman, Jonathan; Stehfest, Elke

2017-12-01

This paper presents an update and extension of HYDE, the History Database of the Global Environment (HYDE version 3.2). HYDE is an internally consistent combination of historical population estimates and allocation algorithms with time-dependent weighting maps for land use. Categories include cropland, with new distinctions for irrigated and rain-fed crops (other than rice) and irrigated and rain-fed rice. Grazing lands are also provided, divided into more intensively used pasture and less intensively used rangeland, and further specified with respect to conversion of natural vegetation to facilitate global change modellers. Population is represented by maps of total, urban, rural population, population density and built-up area. The period covered is 10 000 before Common Era (BCE) to 2015 Common Era (CE). All data can be downloaded from https://doi.org/10.17026/dans-25g-gez3. We estimate that global population increased from 4.4 million people (we also estimate a lower range < 0.01 and an upper range of 8.9 million) in 10 000 BCE to 7.257 billion in 2015 CE, resulting in a global population density increase from 0.03 persons (or capita, in short cap) km-2 (range 0-0.07) to almost 56 cap km-2 respectively. The urban built-up area evolved from almost zero to roughly 58 Mha in 2015 CE, still only less than 0.5 % of the total land surface of the globe. Cropland occupied approximately less than 1 % of the global land area (13 037 Mha, excluding Antarctica) for a long time period until 1 CE, quite similar to the grazing land area. In the following centuries the share of global cropland slowly grew to 2.2 % in 1700 CE (ca. 293 Mha, uncertainty range 220-367 Mha), 4.4 % in 1850 CE (578 Mha, range 522-637 Mha) and 12.2 % in 2015 CE (ca. 1591 Mha, range 1572-1604 Mha). Cropland can be further divided into rain-fed and irrigated land, and these categories can be further separated into rice and non-rice. Rain-fed croplands were much more common, with 2.2 % in 1700 CE (289 Mha, range 217-361 Mha), 4.2 % (549 Mha, range 496-606 Mha) in 1850 CE and 10.1 % (1316 Mha, range 1298-1325 Mha) in 2015 CE, while irrigated croplands used less than 0.05 % (4.3 Mha, range 3.1-5.5 Mha), 0.2 % (28 Mha, range 25-31 Mha) and 2.1 % (277 Mha, range 273-278 Mha) in 1700, 1850 and 2015 CE, respectively. We estimate the irrigated rice area (paddy) to be 0.1 % (13 Mha, range 9-16 Mha) in 1700 CE, 0.2 % (28 Mha, range 26-31 Mha) in 1850 CE and 0.9 % (118 Mha, range 117-120 Mha) in 2015 CE. The estimates for land used for grazing are much more uncertain. We estimate that the share of grazing land grew from 5.1 % in 1700 CE (667 Mha, range 507-820 Mha) to 9.6 % in 1850 CE (1192 Mha, range 1068-1304 Mha) and 24.9 % in 2015 CE (3241 Mha, range 3211-3270 Mha). To aid the modelling community we have divided land used for grazing into more intensively used pasture, less intensively used converted rangeland and less or unmanaged natural unconverted rangeland. Pasture occupied 1.1 % in 1700 CE (145 Mha, range 79-175 Mha), 1.9 % in 1850 CE (253 Mha, range 218-287 Mha) and 6.0 % (787 Mha, range 779-795 Mha) in 2015 CE, while rangelands usually occupied more space due to their occurrence in more arid regions and thus lower yields to sustain livestock. We estimate converted rangeland at 0.6 % in 1700 CE (82 Mha range 66-93 Mha), 1 % in 1850 CE (129 Mha range 118-136 Mha) and 2.4 % in 2015 CE (310 Mha range 306-312 Mha), while the unconverted natural rangelands occupied approximately 3.4 % in 1700 CE (437 Mha, range 334-533 Mha), 6.2 % in 1850 CE (810 Mha, range 733-881 Mha) and 16.5 % in 2015 CE (2145 Mha, range 2126-2164 Mha).

A chemically induced new pea (Pisum sativum) mutant SGECdt with increased tolerance to, and accumulation of, cadmium.

PubMed

Tsyganov, Viktor E; Belimov, Andrei A; Borisov, Alexey Y; Safronova, Vera I; Georgi, Manfred; Dietz, Karl-Josef; Tikhonovich, Igor A

2007-02-01

To date, there are no crop mutants described in the literature that display both Cd accumulation and tolerance. In the present study a unique pea (Pisum sativum) mutant SGECd(t) with increased Cd tolerance and accumulation was isolated and characterized. Ethylmethane sulfonate mutagenesis of the pea line SGE was used to obtain the mutant. Screening for Cd-tolerant seedlings in the M2 generation was performed using hydroponics in the presence of 6 microm CdCl2. Hybridological analysis was used to identify the inheritance of the mutant phenotype. Several physiological and biochemical characteristics of SGECd(t) were studied in hydroponic experiments in the presence of 3 microm CdCl2, and elemental analysis was conducted. The mutant SGECd(t) was characterized as having a monogenic inheritance and a recessive phenotype. It showed increased Cd concentrations in roots and shoots but no obvious morphological defects, demonstrating its capability to cope well with increased Cd levels in its tissues. The enhanced Cd accumulation in the mutant was accompanied by maintenance of homeostasis of shoot Ca, Mg, Zn and Mn contents, and root Ca and Mg contents. Through the application of La(+3) and the exclusion of Ca from the nutrient solution, maintenance of nutrient homeostasis in Cd-stressed SGECd(t) was shown to contribute to the increased Cd tolerance. Control plants of the mutant (i.e. no Cd treatment) had elevated concentrations of glutathione (GSH) in the roots. Through measurements of chitinase and guaiacol-dependent peroxidase activities, as well as proline and non-protein thiol (NPT) levels, it was shown that there were lower levels of Cd stress both in roots and shoots of SGECd(t). Accumulation of phytochelatins [(PCcalculated) = (NPT)-(GSH)] could be excluded as a cause of the increased Cd tolerance in the mutant. The SGECd(t) mutant represents a novel and unique model to study adaptation of plants to toxic heavy metal concentrations.

Effects of cadmium on intercellular junctions in a renal epithelial cell line grown on permeable membrane supports

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

Prozialeck, W.C.; Niewenhuis, R.J.

1991-03-11

Recent findings from the authors laboratories have shown that Cd{sup 2+} has relatively specific damaging effects on adhering and occluding junctions in the established porcine renal epithelial cell line, LLC-PK{sub 1}. The present studies were undertaken in order to further characterize the junction-perturbing effects of Cd{sup 2+} in polarized monolayers of LLC-PK{sub 1} cells, and to begin to identify the mechanisms underlying these effects. LLC-PK{sub 1} cells were grown to confluency on Millicell HA chambers and exposed to Cd{sup 2+} in polarized monolayers of LLC-PK{sub 1} cells, and to begin to identify the mechanisms underlying these effects. LLC-PK{sub 1} cellsmore » were grown to confluency on Millicell HA chambers an exposed to Cd{sup 2+} by adding CdCl{sub 2} to the solutions on either side of the cell monolayer. The integrity of cell-cell junctions was assessed by monitoring the transepithelial electrical resistance. The results showed that exposure to Cd{sup 2+} caused a pronounced decrease in transepithelial resistance without causing the cells to detach from the Millicell membrane. This decrease in resistance occurred more quickly and was much more pronounced when Cd{sup 2+} was added to the basolateral surface rather than the apical surface. Furthermore, the effects of Cd{sup 2+} were greatly reduced when excess Ca{sup 2+} was present in the medium. These results suggest that Cd{sup 2+} was present in the medium. These results suggest that Cd{sup 2+} may disrupt cell-cell junctions by interacting with Ca{sup 2+} binding sites or Ca{sup 2+} channels that are oriented toward the basolateral cell surface.« less

Competitive adsorption-desorption reactions of two hazardous heavy metals in contaminated soils.

PubMed

Davari, Masoud; Rahnemaie, Rasoul; Homaee, Mehdi

2015-09-01

Investigating the interactions of heavy metals is imperative for sustaining environment and human health. Among those, Cd is toxic for organisms at any concentration. While Ni acts as a micronutrient at very low concentration but is hazardous toxic above certain threshold value. In this study, the chemical adsorption and desorption reactions of Ni and Cd in contaminated soils were investigated in both single and binary ion systems. Both Ni and Cd experimental data demonstrated Langmuir type adsorption. In the competitive systems, an antagonistic effect was observed, implying that both ions compete for same type of adsorption sites. Adverse effect of Cd on Ni adsorption was slightly stronger than that of opposite system, consistent with adsorption isotherms in single ion systems. Variation in ionic strength indicated that Ca, a much weaker adsorbate, could also compete with Cd and Ni for adsorption on soil particles. Desorption data indicated that Cd and Ni are adsorbed very tightly such that after four successive desorption steps, less than 0.5 % of initially adsorbed ions released into the soil solution. This implies that Ca, at concentration in equilibrium with calcite mineral, cannot adequately compete with and replace adsorbed Ni and Cd ions. This adsorption behavior was led to considerable hysteresis between adsorption and desorption in both single and binary ion systems. In the binary ion systems, desorption of Cd and Ni was increased by increase in both equilibrium concentration of adsorbed ion and concentration of competitor ion. The overall results obtained in this research indicate that Cd and Ni are strongly adsorbed in calcareous soil and Ca, the major dissolved ion, insignificantly influences metal ions adsorption. Consequently, the contaminated soils by Ni and Cd can simultaneously be remediated by environmentally oriented technologies such as phytoremediation.

Metal-organic frameworks in cadmium(II) complexes with 5-methoxyindole-2-carboxylic acid: structure, vibrational spectra and DFT calculations

NASA Astrophysics Data System (ADS)

Morzyk-Ociepa, Barbara; Szmigiel, Ksenia; Dysz, Karolina; Turowska-Tyrk, Ilona; Michalska, Danuta

2016-11-01

Two new complexes of Cd(II) with an O-deprotonated anion of 5-methoxyindole-2-carboxylic acid (5-MeOI2CA), of the formulas [Cd(5-MeOI2CA)2(H2O)2]n (1) and [Cd3(5-MeOI2CA)6(H2O)4(DMSO)4]ṡ2DMSO (2) were synthesized. In the polymeric complex 1, the 5-MeOI2CA anion acts as a bidentate bridging ligand and the coordination environment around the Cd(II) ion can be described as a distorted octahedron. Single crystal X-ray diffraction analysis of 2 has revealed that this complex is a trimer and it crystallizes in the monoclinic system (space group P21/c with a = 20.3403(4), b = 14.3079(2), c = 15.0603(3) Å, β = 92.4341(17)°, V = 4379.00(14) Å3 and Z = 2). In 2, the 5-MeOI2CA anions act as bidentate bridging and bidentate chelating ligands. The asymmetric unit of 2 contains two crystallographically independent Cd(II) cations. One of the cations is coordinated to six oxygen atoms and shows an octahedral geometry with a rhombic deformation. The other Cd(II) cation adopts a distorted seven-coordinate pentagonal-bipyramidal geometry involving seven oxygen atoms. In 2, the DMSO solvent molecules play a key role in the formation of metal-organic frameworks by filling voids, which are created by the bridging and chelating 5-MeOI2CA anions, the cadmium cations and the other DMSO molecules coordinated to cadmium. Comprehensive theoretical calculations (including the optimized structural parameters, harmonic frequencies and vibrational intensities) were performed for 2 using the B3LYP method with the 6-311++G(d,p)/LanL2DZ basis sets. The infrared and Ramana spectra were measured and a detailed assignment of the experimental spectra of 2 was performed. All cadmium-oxygen stretching vibrations occur in the range below 400 cm-1.

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

Capillary electrophoresis-driven synthesis of water-soluble CdTe quantum dots in nanoliter scale

NASA Astrophysics Data System (ADS)

Nejdl, Lukas; Hynek, David; Adam, Vojtech; Vaculovicova, Marketa

2018-04-01

‘Green nanotechnology’ is a term used for the design of nanomaterials and processes that reduce or eliminate the use and/or generation of hazardous substances. In this paper, a capillary electrophoresis (CE)-driven synthesis of CdTe quantum dots (QDs) and their subsequent conjugation with a metal-binding protein metallothionein (isofom MT1) is reported. Even though the toxic materials (cadmium and potassium borohydride) were used for synthesis, the proposed method can be labeled as ‘environmentally friendly’ because the whole process (synthesis of QDs and MT1 conjugation) was carried out under mild conditions: ultra-low volume (nanoliter scale), relatively low temperature (50 °C), atmospheric pressure, and completed in a short time (under 90 s). Prepared QDs were also characterized by classical fluorescence spectroscopy and transmission electron microscopy. This study opens up new possibilities for the utilization of classical CE in the synthesis of nanoparticles and on-line labeling of biomolecules in the nanoliter scale in short period of time.

Capillary electrophoresis-driven synthesis of water-soluble CdTe quantum dots in nanoliter scale.

PubMed

Nejdl, Lukas; Hynek, David; Adam, Vojtech; Vaculovicova, Marketa

2018-04-20

'Green nanotechnology' is a term used for the design of nanomaterials and processes that reduce or eliminate the use and/or generation of hazardous substances. In this paper, a capillary electrophoresis (CE)-driven synthesis of CdTe quantum dots (QDs) and their subsequent conjugation with a metal-binding protein metallothionein (isofom MT1) is reported. Even though the toxic materials (cadmium and potassium borohydride) were used for synthesis, the proposed method can be labeled as 'environmentally friendly' because the whole process (synthesis of QDs and MT1 conjugation) was carried out under mild conditions: ultra-low volume (nanoliter scale), relatively low temperature (50 °C), atmospheric pressure, and completed in a short time (under 90 s). Prepared QDs were also characterized by classical fluorescence spectroscopy and transmission electron microscopy. This study opens up new possibilities for the utilization of classical CE in the synthesis of nanoparticles and on-line labeling of biomolecules in the nanoliter scale in short period of time.

Metabolic control of T-cell activation and death in SLE

PubMed Central

Fernandez, David; Perl, Andras

2009-01-01

Systemic lupus erythematosus (SLE) is characterized by abnormal T-cell activation and death, processes which are crucially dependent on the controlled production of reactive oxygen intermediates (ROI) and of ATP in mitochondria. The mitochondrial transmembrane potential (Δψm) has conclusively emerged as a critical checkpoint of ATP synthesis and cell death. Lupus T cells exhibit persistent elevation of Δψm or mitochondrial hyperpolarization (MHP) as well as depletion of ATP and glutathione which decrease activation-induced apoptosis and instead predispose T cells for necrosis, thus stimulating inflammation in SLE. NO-induced mitochondrial biogenesis in normal T cells accelerates the rapid phase and reduces the plateau of Ca2+ influx upon CD3/CD28 co-stimulation, thus mimicking the Ca2+ signaling profile of lupus T cells. Treatment of SLE patients with rapamycin improves disease activity, normalizes CD3/CD28-induced Ca2+ fluxing but fails to affect MHP, suggesting that altered Ca2+ fluxing is downstream or independent of mitochondrial dysfunction. Understanding the molecular basis and consequences of MHP is essential for controlling T-cell activation and death signaling in SLE. Lupus T cells exhibit mitochondrial dysfunctionMitochondrial hyperpolarization (MHP) and ATP depletion predispose lupus T cells to death by necrosis which is pro-inflammatoryMHP is caused by depletion of glutathione and exposure to nitric oxide (NO)NO-induced mitochondrial biogenesis regenerates the Ca2+ signaling profile of lupus T cellsRapamycin treatment normalizes Ca2+ fluxing but not MHP, suggesting that the mammalian target of rapamycin, acts as a sensor and effector of MHP in SLE PMID:18722557

Activated STAT5 promotes long-lived cytotoxic CD8+ T cells that induce regression of autochthonous melanoma.

PubMed

Grange, Magali; Buferne, Michel; Verdeil, Grégory; Leserman, Lee; Schmitt-Verhulst, Anne-Marie; Auphan-Anezin, Nathalie

2012-01-01

Immunotherapy based on adoptive transfer of tumor antigen-specific CD8(+) T cell (TC) is generally limited by poor in vivo expansion and tumor infiltration. In this study, we report that activated STAT5 transcription factors (STAT5CA) confer high efficiency on CD8(+) effector T cells (eTC) for host colonization after adoptive transfer. Engineered expression of STAT5CA in antigen-experienced TCs with poor replicative potential was also sufficient to convert them into long-lived antigen-responsive eTCs. In transplanted mastocytoma- or melanoma-bearing hosts, STAT5CA greatly enhanced the ability of eTCs to accumulate in tumors, become activated by tumor antigens, and to express the cytolytic factor granzyme B. Taken together, these properties contributed to an increase in tumor regression by STAT5CA-transduced, as compared with untransduced, TCs including when the latter control cells were combined with infusion of interleukin (IL)-2/anti-IL-2 complexes. In tumors arising in the autochthonous TiRP transgenic model of melanoma associated with systemic chronic inflammation, endogenous CD8(+) TCs were nonfunctional. In this setting, adoptive transfer of STAT5CA-transduced TCs produced superior antitumor effects compared with nontransduced TCs. Our findings imply that STAT5CA expression can render TCs resistant to the immunosuppressive environment of melanoma tumors, enhancing their ability to home to tumors and to maintain high granzyme B expression, as well as their capacity to stimulate granzyme B expression in endogenous TCs. ©2011 AACR.

New Antimony Selenide/Nickel Oxide Photocathode Boosts the Efficiency of Graphene Quantum-Dot Co-Sensitized Solar Cells.

PubMed

Kolay, Ankita; Kokal, Ramesh K; Kalluri, Ankarao; Macwan, Isaac; Patra, Prabir K; Ghosal, Partha; Deepa, Melepurath

2017-10-11

A novel assembly of a photocathode and a photoanode is investigated to explore their complementary effects in enhancing the photovoltaic performance of a quantum-dot solar cell (QDSC). While p-type nickel oxide (NiO) has been used previously, antimony selenide (Sb 2 Se 3 ) has not been used in a QDSC, especially as a component of a counter electrode (CE) architecture that doubles as the photocathode. Here, near-infrared (NIR) light-absorbing Sb 2 Se 3 nanoparticles (NPs) coated over electrodeposited NiO nanofibers on a carbon (C) fabric substrate was employed as the highly efficient photocathode. Quasi-spherical Sb 2 Se 3 NPs, with a band gap of 1.13 eV, upon illumination, release photoexcited electrons in addition to other charge carriers at the CE to further enhance the reduction of the oxidized polysulfide. The p-type conducting behavior of Sb 2 Se 3 , coupled with a work function at 4.63 eV, also facilitates electron injection to polysulfide. The effect of graphene quantum dots (GQDs) as co-sensitizers as well as electron conduits is also investigated in which a TiO 2 /CdS/GQDs photoanode structure in combination with a C-fabric CE delivered a power-conversion efficiency (PCE) of 5.28%, which is a vast improvement over the 4.23% that is obtained by using a TiO 2 /CdS photoanode (without GQDs) with the same CE. GQDs, due to a superior conductance, impact efficiency more than Sb 2 Se 3 NPs do. The best PCE of a TiO 2 /CdS/GQDs-nS 2- /S n 2- -Sb 2 Se 3 /NiO/C-fabric cell is 5.96% (0.11 cm 2 area), which, when replicated on a smaller area of 0.06 cm 2 , is seen to increase dramatically to 7.19%. The cell is also tested for 6 h of continuous irradiance. The rationalization for the channelized photogenerated electron movement, which augments the cell performance, is furnished in detail in these studies.

Simulated Impact of Climate Change on Fremont Native American Maize Farming in Utah at the MCA-LIA Transition, ca. 12-14th c. CE

NASA Astrophysics Data System (ADS)

Thomson, M. J.; MacDonald, G. M.

2016-12-01

We present the results of a computational crop modeling experiment for ancient Fremont Native American Zea mays farming in the Uinta Basin, Utah, at the Medieval Climate Anomaly to Little Ice Age (MCA-LIA) transition, ca. 850-1450 CE. This period coincides with the rapid disappearance of complex Native American cultures from the American Southwest. The crop model (the Environment Policy Impact Calculator, EPIC) was driven by statistically downscaled precipitation, temperature and shortwave radiative flux from the Community Earth System Model Last Millennium Ensemble (CESM LME). We found that maize yield responded to changes in the model-reconstructed temperature and precipitation; and periods of reduced maize yields corresponded to the abandonment of higher elevation Fremont 14C-dated archaeological sites. EPIC produces good agreement between modeled and historically reported maize yields for the 19th century.

Photosynthesis is improved by exogenous calcium in heat-stressed tobacco plants.

PubMed

Tan, Wei; Meng, Qing wei; Brestic, Marian; Olsovska, Katarina; Yang, Xinghong

2011-11-15

Effects of exogenous calcium chloride (CaCl(2)) (20 mM) on photosynthetic gas exchange, photosystem II photochemistry, and the activities of antioxidant enzymes in tobacco plants under high temperature stress (43°C for 2 h) were investigated. Heat stress resulted in a decrease in net photosynthetic rate (P(n)), stomatal conductance as well as the apparent quantum yield (AQY) and carboxylation efficiency (CE) of photosynthesis. Heat stress also caused a decrease of the maximal photochemical efficiency of primary photochemistry (F(v)/F(m)). On the other hand, CaCl(2) application improved P(n), AQY, and CE as well as F(v)/F(m) under high temperature stress. Heat stress reduced the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD), whereas the activities of these enzymes either decreased less or increased in plants pretreated with CaCl(2); glutathione reductase (GR) activity increased under high temperature, and it increased more in plants pretreated with CaCl(2). There was an obvious accumulation of H(2)O(2) and O(2)(-) under high temperature, but CaCl(2) application decreased the contents of H(2)O(2) and O(2)(-) under heat stress conditions. Heat stress induced the level of heat shock protein 70 (HSP70), while CaCl(2) pretreatment enhanced it. These results suggested that photosynthesis was improved by CaCl(2) application in heat-stressed plants and such an improvement was associated with an improvement in stomatal conductance and the thermostability of oxygen-evolving complex (OEC), which might be due to less accumulation of reactive oxygen species. Copyright © 2011 Elsevier GmbH. All rights reserved.

Effect of Heat Treatment Parameters on the Characteristics of Thin Wall Austempered Ductile Iron Casting

NASA Astrophysics Data System (ADS)

Upadhyaya, Rajat; Singh, K. K.; Kumar, Rajeev

2018-03-01

The technology of thin parts is necessary steps to designers for energy consuming equipment to choose accurate material based on material properties. Here austempering treatment process was utilized to acquire thin wall austempered ductile iron castings. The plate thickness (2-5) mm were austenitized at 900 °C for, 30 minutes took after by holding at 350°C, 400°C and 450°C inoculated by Ce-Ca-Al-S-O-FeSi,Zr-Mn-Ca-Al-Ba-FeSi and Sr-Al-Ca-FeSi at 0.2wt%,0.4wt% and 0.6wt% for 2,5 and 10 minutes for every temperature.The austempered samples are comparatively harder than the as-cast ductile iron plates. The micro hardness(HV20) also decreases with increase in austempering temperature for a given austempering time for thinner plates and also the micro hardness(HV20) is more for the samples treated at 350°C than those treated at 400°C and 450°C at 0.4wt% for a given austempering time. The yield strength and ultimate tensile strength of 2 mm thin wall austempered ductile iron are higher and ductility and impact strength are lower than that of as-cast 2 mm thin plate ductile iron inoculated by Ce-Ca-Al-S-O-FeSi compare to Zr-Mn-Ca-Al-Ba-FeSi and Sr-Al-Ca-FeSi at 0.4wt%. This may be attributed to the change in the structure change from ferrite-pearlite to austenite-bainite.

Effect of Soil Amendments on Cd accumulation by Spinach from a Cd-Mineralized Soil

USDA-ARS?s Scientific Manuscript database

Cadmium mineralized soils occur in many nations. When these soils are non-calcareous, crops and especially leafy vegetables such as lettuce and spinach accumulate levels of Cd which exceed international standards. Lockwood loam from Monterey Co., CA, has been found to cause excessive Cd in leafy veg...

Cyclic adenosine 5'-monophosphate and calcium induce CD152 (CTLA-4) up-regulation in resting CD4+ T lymphocytes.

PubMed

Vendetti, Silvia; Riccomi, Antonella; Sacchi, Alessandra; Gatta, Lucia; Pioli, Claudio; De Magistris, Maria Teresa

2002-12-01

The CTLA-4 (CD152) molecule is up-regulated upon T cell activation and proliferation, and plays a critical role in the inhibition of immune responses. We show in this study that cAMP induces up-regulation of CD152 in human CD4(+) T lymphocytes. This effect occurs in the absence of the up-regulation of CD69 and CD25 activation markers and T cell proliferation. In addition, we found that the Ca(2+) ionophore ionomycin also up-regulates CD152, and that the combination of a cAMP analog or cAMP inducers with ionomycin further enhances the expression of CD152 in resting CD4(+) T lymphocytes. However, cyclosporin A, which inhibits Ca(2+)/calcineurin signaling pathway, fully prevented the ionomycin- but not the cAMP-induced up-regulation of CD152. The effects of cAMP and ionomycin involve increase of both CD152 mRNA transcripts, coding for the membrane and the soluble forms of CD152. Furthermore, we show that CD152 molecules are translocated to the membrane and are functional, as their engagement by specific mAbs prevented NF-kappaB activation by anti-CD3/CD28 stimulation. These findings demonstrate that at least two novel signal pathways regulate CTLA-4 gene expression and CD152 molecule up-regulation in human CD4(+) T lymphocytes, in the absence of full T cell activation.

Design of a photoswitchable hollow microcapsular drug delivery system by using a supramolecular drug-loading approach.

PubMed

Xiao, Wang; Chen, Wei-Hai; Zhang, Jing; Li, Cao; Zhuo, Ren-Xi; Zhang, Xian-Zheng

2011-11-24

In this study, photoswitchable microcapsules were fabricated based on host-guest interactions between α-cyclodextrin (α-CD) and azobenzene (Azo). Carboxymethyl dextran-graft-α-CD (CMD-g-α-CD) and poly(acrylic acid) N-aminododecane p-azobenzeneaminosuccinic acid (PAA-C(12)-Azo) were assembled layer by layer on CaCO(3) particles. α-CD-rhodamine B (α-CD-RhB), used as a model drug, was loaded on PAA-C(12)-Azo layers by host-guest interaction. After removal of CaCO(3) particles by ethylenediaminetetraacetic acid (EDTA), hollow microcapsules loaded with α-CD-RhB were obtained. Since the interactions between α-CD and Azo were photosensitive, the capsules could be dissociated with the irradiation of UV light, followed by the release of the model drug, α-CD-RhB. Compared with traditional drug-loading approaches such as chemical bonding and physical adsorption, our supramolecular drug-loading system has a facile loading process, ideal bonding strength, and photoswitchable behavior. These photosensitive microcapsules exhibit great potential in biomedical applications. © 2011 American Chemical Society

Reading comprehension skills of young adults with childhood diagnoses of dyslexia.

PubMed

Ransby, Marilyn J; Swanson, H Lee

2003-01-01

This study explores the contribution of cognitive processes to comprehension skills in adults who suffered from childhood developmental dyslexia (CD). The performance of adults with CD (ages 17 to 23), chronological age-matched (CA) adults, and reading level-matched (RL) children was compared on measures of phonological processing, naming speed, working memory (WM), general knowledge, vocabulary, and comprehension. The results showed that adults with CD scored lower on measures of phonological processing, naming speed, WM, general knowledge, and vocabulary when compared to CA readers but were comparable to RL children on the majority of process measures. Phonological processing, naming speed, vocabulary, general knowledge, and listening comprehension contributed independent variance to reading comprehension accuracy, whereas WM, intelligence, phonological processing, and listening comprehension contributed independent variance to comprehension fluency. Adults with CD scored lower than CA adults and higher than RL children on measures of lexical processing, WM, and listening comprehension when word recognition and intelligence were partialed from the analysis. In summary, constraints in phonological processing and naming speed mediate only some of the influence of high-order processes on reading comprehension. Furthermore, adults with CD experience difficulties in WM, listening comprehension, and vocabulary independently of their word recognition problems and intellectual ability.

Using reduced graphene oxide-Ca:CdSe nanocomposite to enhance photoelectrochemical activity of gold nanoparticles functionalized tungsten oxide for highly sensitive prostate specific antigen detection.

PubMed

Wang, Xueping; Xu, Rui; Sun, Xu; Wang, Yaoguang; Ren, Xiang; Du, Bin; Wu, Dan; Wei, Qin

2017-10-15

An ultrasensitive sandwich-type photoelectrochemical (PEC) immunosensor was constructed for the detection of prostate specific antigen (PSA). In this work, Au-nanoparticle-loaded tungsten oxide (WO 3 -Au) hybrid composites was applied as PEC sensing platform, while Ca ions doped CdSe equipped on the conducting framework of reduced graphene oxide (rGO-Ca:CdSe) nanocomposites were employed as the signal amplification probe. As for WO 3 -Au, massive Au nanoparticles were formed on the surface of WO 3 without any additional reducing agent, providing a novel nanocarriers for anchoring plenty of the primary antibodies due to the large specific surface area and good biocompatibility by chemical bonding between Au nanoparticles and -NH 2 of antibodies. Besides, the incorporation of the rGO and the doping of Ca ions could improve the conductivity and hinder the recombination of electron-hole pairs of CdSe nanoparticles effectively, thereby enhancing the photocurrent conversion efficiency. Based on the sandwich immunoreaction, the primary antibody was immobilized onto WO 3 -Au substrate, after the formed rGO-Ca:CdSe labels were captured onto the electrode surface via the specific antibody-antigen interaction, the photocurrent intensity could be further enhanced due to the sensitization effect. Under the optimal conditions, the proposed PEC immunosensor shows a linear relationship between photocurrent variation and the logarithm of PSA concentration in the wide range of 5pgmL -1 to 50ngmL -1 with a low detection limit of 2.6pgmL -1 (S/N=3). Moreover, it also presented good stability and acceptable specificity, indicating the potential applications in clinical diagnostics. Copyright © 2017 Elsevier B.V. All rights reserved.

Cholesterol regulates contractility and inotropic response to β2-adrenoceptor agonist in the mouse atria: Involvement of Gi-protein-Akt-NO-pathway.

PubMed

Odnoshivkina, Yulia G; Sytchev, Vaycheslav I; Petrov, Alexey M

2017-06-01

Majority of cardiac β2-adrenoceptors is located in cholesterol-rich microdomains. Here, we have investigated the underlying mechanisms by which a slight to moderate cholesterol depletion with methyl-β-cyclodextrin (MβCD, 1 and 5mM) interferes with contractility and inotropic effect of β2-adrenergic agonist (fenoterol, 50μM) in the mouse atria. Treatment with MβCD itself increased amplitude of Ca 2+ transient but did not change the contraction amplitude due to a clamping action of elevated NO. Cholesterol depletion significantly attenuated the positive inotropic response to fenoterol which is accompanied by increase in NO generation and decrease in Ca 2+ transient. Influence of 1mM MβCD on the fenoterol-driven changes in both contractility and NO level was strongly attenuated by inhibition of G i -protein (pertussis toxin), Akt (Akt 1/2 kinase inhibitor) or NO-synthase (L-NAME). After exposure to 5mM MβCD, pertussis toxin or Akt inhibitor could recover the β2-agonist effects on contractility, NO production and Ca 2+ transient, while L-NAME only reduced NO level. An adenylyl cyclase activator (forskolin, 50nM) had no influence on the MβCD-induced changes in the β2-agonist effects. Obtained results suggest that slight cholesterol depletion upregulates G i -protein/Akt/NO-synthase signaling that attenuates the positive inotropic response to β2-adrenergic stimulation without altering the Ca 2+ transient. Whilst moderate cholesterol depletion additionally could suppress the enhancement of the Ca 2+ transient amplitude caused by the β2-adrenergic agonist administration in G i -protein/Akt-dependent but NO-independent manner. Copyright © 2016 Elsevier Ltd. All rights reserved.

ATP Releasing Connexin 30 Hemichannels Mediate Flow-Induced Calcium Signaling in the Collecting Duct

PubMed Central

Svenningsen, Per; Burford, James L.; Peti-Peterdi, János

2013-01-01

ATP in the renal tubular fluid is an important regulator of salt and water reabsorption via purinergic calcium signaling that involves the P2Y2 receptor, ENaC, and AQP2. Recently, we have shown that connexin (Cx) 30 hemichannels are localized to the non-junctional apical membrane of cells in the distal nephron-collecting duct (CD) and release ATP into the tubular fluid upon mechanical stimuli, leading to reduced salt and water reabsorption. Cx30−/− mice show salt-dependent elevations in BP and impaired pressure-natriuresis. Thus, we hypothesized that increased tubular flow rate leads to Cx30-dependent purinergic intracellular calcium ([Ca2+]i) signaling in the CD. Cortical CDs (CCDs) from wild type and Cx30−/− mice were freshly dissected and microperfused in vitro. Using confocal fluorescence imaging and the calcium-sensitive fluorophore pair Fluo-4 and Fura Red, we found that increasing tubular flow rate from 2 to 20 nl/min caused a significant 2.1-fold elevation in [Ca2+]i in wild type CCDs. This response was blunted in Cx30−/− CCDs ([Ca2+]i increased only 1.2-fold, p < 0.0001 vs. WT, n = 6 each). To further test our hypothesis we performed CD [Ca2+]i imaging in intact mouse kidneys in vivo using multiphoton microscopy and micropuncture delivery of the calcium-sensitive fluorophore Rhod-2. We found intrinsic, spontaneous [Ca2+]i oscillations in free-flowing CDs of wild type but not Cx30−/− mice. The [Ca2+]i oscillations were sensitive also to P2-receptor inhibition by suramin. Taken together, these data confirm that mechanosensitive Cx30 hemichannels mediate tubular ATP release and purinergic calcium signaling in the CD which mechanism plays an important role in the regulation of CD salt and water reabsorption. PMID:24137132

Epigallocatechin-3-gallate (EGCG) up-regulates miR-15b expression thus attenuating store operated calcium entry (SOCE) into murine CD4+ T cells and human leukaemic T cell lymphoblasts.

PubMed

Zhang, Shaqiu; Al-Maghout, Tamer; Bissinger, Rosi; Zeng, Ni; Pelzl, Lisann; Salker, Madhuri S; Cheng, Anchun; Singh, Yogesh; Lang, Florian

2017-10-27

CD4 + T cells are key elements in immune responses and inflammation. Activation of T cell receptors in CD4 + T cells triggers cytosolic Ca 2+ release with subsequent store operated Ca 2+ entry (SOCE), which is accomplished by the pore forming Ca 2+ release activated Ca 2+ (CRAC) channel Orai1 and its regulator stromal cell-interaction molecule 2 (STIM2). Green tea polyphenol epigallocatechin-3-gallate (EGCG) acts as a potent anti-inflammatory and anti-oxidant agent for various types of cells including immune cells. However, how post-transcriptional gene regulators such as miRNAs are involved in the regulation of Ca 2+ influx into murine CD4 + T cells and human Jurkat T cells through EGCG is not defined. EGCG treatment of murine CD4 + T cells significantly down-regulated the expression of STIM2 and Orai1 both at mRNA and protein levels. Furthermore, EGCG significantly decreased SOCE in both murine and human T cells. EGCG treatment increased miRNA-15b (miR-15b) abundance in both murine and human T cells. Bioinformatics analysis reveals that miR-15b, which has a STIM2 binding site, is involved in the down-regulation of SOCE. Overexpression of miR-15b significantly decreased the mRNA and protein expression of STIM2 and Orai1 in murine T cells. Treatment of Jurkat T cells with 10 μM EGCG further decreased mTOR and PTEN protein levels. EGCG decreased mitochondrial membrane potential (MMP) in both human and murine T cells. In conclusion, the observations suggest that EGCG inhibits the Ca 2+ entry into murine and human T cells, an effect accomplished at least in part by up-regulation of miR-15b.

Rubidium as an Alternative Cation for Efficient Perovskite Light-Emitting Diodes.

PubMed

Kanwat, Anil; Moyen, Eric; Cho, Sinyoung; Jang, Jin

2018-05-16

Incorporation of rubidium (Rb) into mixed lead halide perovskites has recently achieved record power conversion efficiency and excellent stability in perovskite solar cells. Inspired by these tremendous advances in photovoltaics, this study demonstrates the impact of Rb incorporation into MAPbBr 3 -based light emitters. Rb partially substitutes MA (methyl ammonium), resulting in a mixed cation perovskite with the formula MA (1- x) Rb x PbBr 3 . Pure MAPbBr 3 crystallizes into a polycrystalline layer with highly defective sub-micrometer grains. However, the addition of a small amount of Rb forms MA (1- x) Rb x PbBr 3 nanocrystals (10 nm) embedded in an amorphous matrix of MA/Rb Br. These nanocrystals grow into defect-free sub-micrometer-sized crystallites with further addition of Rb, resulting in a 3-fold increase in exciton lifetime when the molar ratio of MABr/RbBr is 1:1. A thin film fabricated with a 1:1 molar ratio of MABr/RbBr showed the best electroluminescent properties with a current efficiency (CE) of 9.45 cd/A and a luminance of 7694 cd/m 2 . These values of CE and luminance are, respectively, 19 and 10 times larger than those achieved by pure MAPbBr 3 devices (0.5 cd/A and 790 cd/m 2 ). We believe this work provides important information on the future compositional optimization of Rb + -based mixed cation perovskites for obtaining high-performance light-emitting diodes.

The performance of moss, grass, and 1- and 2-year old spruce needles as bioindicators of contamination: a comparative study at the scale of the Czech Republic.

PubMed

Suchara, Ivan; Sucharova, Julie; Hola, Marie; Reimann, Clemens; Boyd, Rognvald; Filzmoser, Peter; Englmaier, Peter

2011-05-01

Moss (Pleurozium schreberi), grass (Avenella flexuosa), and 1- and 2-year old spruce (Picea abies) needles were collected over the territory of the Czech Republic at an average sample density of 1 site per 290km(2). The samples were analysed for 39 elements (Ag, Al, As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, Hg, K, La, Li, Mg, Mn, Mo, Na, Nd, Ni, Pb, Pr, Rb, S, Sb, Se, Sn, Sr, Th, Tl, U, V, Y and Zn) using ICP-MS and ICP-AES techniques (the major nutrients Ca, K, Mg and Na were not analysed in moss). Moss showed by far the highest element concentrations for most elements. Exceptions were Ba (spruce), Mn (spruce), Mo (grass), Ni (spruce), Rb (grass) and S (grass). Regional distribution maps and spatial trend analysis were used to study the suitability of the four materials as bioindicators of anthropogenic contamination. The highly industrialised areas in the north-west and the far east of the country and several more local contamination sources were indicated in the distribution maps of one or several sample materials. At the scale of the whole country moss was the best indicator of known contamination sources. However, on a more local scale, it appeared that spruce needles were especially well suited for detection of urban contamination. Copyright © 2010 Elsevier B.V. All rights reserved.

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

Baljinnyam, N.; Frontasyeva, M. V.; Ostrovnaya, T. M.

Asian medicinal herbs Chrysanthemum (Spiraea aquilegifolia Pall.) and Red Sandalwood (Pterocarpus Santalinus) are widely used in folk and Ayurvedic medicine for healing and preventing some diseases. The modern medical science has proved that the Chrysanthemum (Spiraea aquilegifolia Pall.) possesses the following functions: reducing blood press, dispelling cancer cell, coronary artery's expanding and bacteriostating and Red Sandalwood (Pterocarpus Santalinus) is recommended against headache, toothache, skin diseases, vomiting and sometimes it is taken for treatment of diabetes. Species of Chrysanthemums were collected in the north-eastern and central Mongolia, and the Red Sandalwood powder was imported from India. Samples of Chrysanthemums (branches, flowersmore » and leaves)(0.5 g) and red sandalwood powder (0.5 g) were subjected to the multi-element instrumental neutron activation analysis using epithermal neutrons (ENAA) at the IBR-2 reactor, Frank Laboratory of Neutron Physics (FLNP) JINR, Dubna. A total of 41 elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Cd, Cs, Ba, La, Hf, Ta, W, Sb, Au, Hg, Ce, Nd, Sm, Eu, Tb, Dy, Yb, Th, U, Lu) were determined. For the first time such a large group of elements was determined in the herbal plants used in Mongolia. The quality control of the analytical results was provided by using certified reference material Bowen Cabbage. The results obtained are compared to the ''Reference plant? data (B. Markert, 1992) and interpreted in terms of excess of such elements as Se, Cr, Ca, Fe, Ni, Mo, and rare earth elements.« less

Roles of Ca(v) channels and AHNAK1 in T cells: the beauty and the beast.

PubMed

Matza, Didi; Flavell, Richard A

2009-09-01

T lymphocytes require Ca2+ entry though the plasma membrane for their activation and function. Recently, several routes for Ca2+ entry through the T-cell plasma membrane after activation have been described. These include calcium release-activated channels (CRAC), transient receptor potential (TRP) channels, and inositol-1,4,5-trisphosphate receptors (IP3Rs). Herein we review the emergence of a fourth new route for Ca2+ entry, composed of Ca(v) channels (also known as L-type voltage-gated calcium channels) and the scaffold protein AHNAK1 (AHNAK/desmoyokin). Both helper (CD4+) and killer (CD8+) T cells express high levels of Ca(v)1 alpha1 subunits (alpha1S, alpha1C, alpha1D, and alpha1F) and AHNAK1 after their differentiation and require these molecules for Ca2+ entry during an immune response. In this article, we describe the observations and open questions that ultimately suggest the involvement of multiple consecutive routes for Ca2+ entry into lymphocytes, one of which may be mediated by Ca(v) channels and AHNAK1.

Synthesis and characterization of lanthanide based nanomaterials for radiation detection and biomedical applications

NASA Astrophysics Data System (ADS)

Yao, Mingzhen

2011-12-01

Lanthanide based nanomaterials have shown a great potential in various areas such as luminescence imaging, luminescent labels, and detection of cellular functions. Due to the f-f transitions of the metal ion, luminescence of lanthanide ions is characterized by sharp and narrow emissions. In this dissertation lanthanide based nanoparticles such as Ce3+, Eu3+ and other lanthanide ions doped LaF3 were synthesized, their characterization, encapsulation and embedding into hybrid matrix were investigated and some of their biomedical and radiological applications were studied. DMSO is a common solvent which has been used widely for biological applications. LaF3:Ce nanoparticles were synthesized in DMSO and it was found that their fluorescent emission originates from the metal-to-ligand charge-transfer excited states. After conjugation with PpIX and then encapsulation within PLGA, the particles show efficient uptake by cancer cells and great cytotoxicity, which is promising for applications in cancer treatments. However, the emission of Eu3+ in DMSO is totally different from LaF3:Ce, very strong characteristic luminescence is observed but no emissions from metal-to-ligand charge-transfer excited states as observed in LaF3:Ce in DMSO. Besides, it is very interesting to see that the coupling of Eu 3+ with O-H oscillations after water was introduced has an opposite effect on emission peaks at 617 nm and its shoulder peak at 613 nm. As a result, the intensity ratio of these two emissions has a nearly perfect linear dependence on increasing water concentration in Eu-DMSO, which provides a very convenient and valuable method for water determination in DMSO. Ce3+ has been well known as an emitter for radiation detection due to its very short decay lifetime. However, its emission range limited the environment in which the detection system works. Whereas, Quantum dots have high luminescence quantum efficiency but their low stopping power results in very weak scintillation luminescence. Nanocompounds formed with CdTe quantum dots and LaF3:Ce nanoparticles optimize both stopping power and scintillation efficiency based on energy transfer from LaF3:Ce to CdTe. Hybrid matrix materials such as ORMOSIL have superior mechanical properties and a better processability than pure molecular material which could be used as carrier of radiation material. Moreover, embedding a lanthanide complex in a hybrid matrix enhances its thermal stability and luminescence output. LaF3:Ce doped ORMOSIL was synthesized by using two different LaF3:Ce, the nanoparticle doping concentration can reach up to 15.66% while its transparency and luminescent properties were maintained. These materials are very promising for radiation detection.

CD44v6 expression in human skin keratinocytes as a possible mechanism for carcinogenesis associated with chronic arsenic exposure.

PubMed

Huang, S; Guo, S; Guo, F; Yang, Q; Xiao, X; Murata, M; Ohnishi, S; Kawanishi, S; Ma, N

2013-01-14

Inorganic arsenic is a well-known human skin carcinogen. Chronic arsenic exposure results in various types of human skin lesions, including squamous cell carcinoma (SCC). To investigate whether mutant stem cells participate in arsenic-associated carcinogenesis, we repeatedly exposed the HaCaT cells line to an environmentally relevant level of arsenic (0.05 ppm) in vitro for 18 weeks. Following sodium arsenic arsenite administration, cell cycle, colony-forming efficiency (CFE), cell tumorigenicity, and expression of CD44v6, NF-κB and p53, were analyzed at different time points (0, 5, 10, 15, 20, 25 and 30 passages). We found that a chronic exposure of HaCaT cells to a low level of arsenic induced a cancer stem- like phenotype. Furthermore, arsenic-treated HaCaT cells also became tumorigenic in nude mice, their growth cycle was predominantly in G2/M and S phases. Relative to nontreated cells, they exhibited a higher growth rate and a significant increase in CFE. Western blot analysis found that arsenic was capable of increasing cell proliferation and sprouting of cancer stem-like phenotype. Additionally, immunohistochemical analysis demonstrated that CD44v6 expression was up-regulated in HaCaT cells exposed to a low level of arsenic during early stages of induction. The expression of CD44v6 in arsenic-treated cells was positively correlated with their cloning efficiency in soft agar (r=0.949, P=0.01). Likewise, the expressions of activating transcription factor NF-κB and p53 genes in the arsenic-treated HaCaT cells were significantly higher than that in non-treated cells. Higher expressions of CD44v6, NF-κB and p53 were also observed in tumor tissues isolated from Balb/c nude mice. The present results suggest that CD44v6 may be a biomarker of arsenic-induced neoplastic transformation in human skin cells, and that arsenic promotes malignant transformation in human skin lesions through a NF-κB signaling pathway-stimulated expression of CD44v6.

Structural plasticity: how intermetallics deform themselves in response to chemical pressure, and the complex structures that result.

PubMed

Berns, Veronica M; Fredrickson, Daniel C

2014-10-06

Interfaces between periodic domains play a crucial role in the properties of metallic materials, as is vividly illustrated by the way in which the familiar malleability of many metals arises from the formation and migration of dislocations. In complex intermetallics, such interfaces can occur as an integral part of the ground-state crystal structure, rather than as defects, resulting in such marvels as the NaCd2 structure (whose giant cubic unit cell contains more than 1000 atoms). However, the sources of the periodic interfaces in intermetallics remain mysterious, unlike the dislocations in simple metals, which can be associated with the exertion of physical stresses. In this Article, we propose and explore the concept of structural plasticity, the hypothesis that interfaces in complex intermetallic structures similarly result from stresses, but ones that are inherent in a defect-free parent structure, rather than being externally applied. Using DFT-chemical pressure analysis, we show how the complex structures of Ca2Ag7 (Yb2Ag7 type), Ca14Cd51 (Gd14Ag51 type), and the 1/1 Tsai-type quasicrystal approximant CaCd6 (YCd6 type) can all be traced to large negative pressures around the Ca atoms of a common progenitor structure, the CaCu5 type with its simple hexagonal 6-atom unit cell. Two structural paths are found by which the compounds provide relief to the Ca atoms' negative pressures: a Ca-rich pathway, where lower coordination numbers are achieved through defects eliminating transition metal (TM) atoms from the structure; and a TM-rich path, along which the addition of spacer Cd atoms provides the Ca coordination environments greater independence from each other as they contract. The common origins of these structures in the presence of stresses within a single parent structure highlights the diverse paths by which intermetallics can cope with competing interactions, and the role that structural plasticity may play in navigating this diversity.

Trace element evidence for abrupt changes in deep South Atlantic Ocean nutrient and carbonate chemistry across the Mid-Pleistocene Transition

NASA Astrophysics Data System (ADS)

Farmer, J. R.; Hoenisch, B.; Haynes, L.; Kroon, D.; Bell, D. B.; Jung, S.; Seguí, M. J.; Raymo, M. E.; Goldstein, S. L.; Pena, L. D.

2016-12-01

Pleistocene glaciations underwent a profound transition from lower amplitude 40 kyr cycles to high amplitude 100 kyr cycles between 1.2 and 0.8 Ma, an interval termed the Mid-Pleistocene Transition (MPT). While the underlying causes of the MPT are uncertain, previous studies show quasi-contemporaneous reductions in North Atlantic Deep Water (NADW) export1 and glacial atmospheric pCO22 around 0.9 Ma. Although this suggests a possible role for enhanced deep-ocean carbon storage in amplifying climate change across the MPT, few direct records of deep ocean carbonate chemistry exist for this interval to test this hypothesis. Here we present South Atlantic benthic foraminiferal B/Ca and Cd/Ca records from International Ocean Discovery Program Sites 1088, 1264 and 1267 (2.1 to 4.3 km water depth) as part of a larger study of Atlantic-wide changes in deep ocean chemistry and circulation spanning the MPT. Results show an abrupt 15-20% decrease in benthic B/Ca and 40-50% increase in Cd/Ca at 4.3 km depth (Site 1267) between 1.0 and 0.9 Ma. Site 1088, which at 2.1 km depth is sensitive to input of southern-sourced Upper Circumpolar Deep Water, shows a prolonged 25% decrease in B/Ca and 50% increase in Cd/Ca from 1.0 to 0.6 Ma. In contrast, at Site 1264 ( 2.5 km depth within the core of modern NADW) B/Ca and Cd/Ca changes across the MPT are more modest (-5% and +10%, respectively). These observations reflect on the accumulation of regenerated carbon and nutrients in the deep South Atlantic, and varying contributions of northern- and southern-sourced watermasses to each core site. Implications for deep-ocean carbon storage and forcing of the MPT will be discussed. 1Pena, L. and Goldstein, S. (2014), Science 345, 318 2Hönisch, B. et al. (2009), Science 324, 1551

Fate of Cd during microbial Fe(III) mineral reduction by a novel and Cd-tolerant Geobacter species.

PubMed

Muehe, E Marie; Obst, Martin; Hitchcock, Adam; Tyliszczak, Tolek; Behrens, Sebastian; Schröder, Christian; Byrne, James M; Michel, F Marc; Krämer, Ute; Kappler, Andreas

2013-12-17

Fe(III) (oxyhydr)oxides affect the mobility of contaminants in the environment by providing reactive surfaces for sorption. This includes the toxic metal cadmium (Cd), which prevails in agricultural soils and is taken up by crops. Fe(III)-reducing bacteria can mobilize such contaminants by Fe(III) mineral dissolution or immobilize them by sorption to or coprecipitation with secondary Fe minerals. To date, not much is known about the fate of Fe(III) mineral-associated Cd during microbial Fe(III) reduction. Here, we describe the isolation of a new Geobacter sp. strain Cd1 from a Cd-contaminated field site, where the strain accounts for 10(4) cells g(-1) dry soil. Strain Cd1 reduces the poorly crystalline Fe(III) oxyhydroxide ferrihydrite in the presence of at least up to 112 mg Cd L(-1). During initial microbial reduction of Cd-loaded ferrihydrite, sorbed Cd was mobilized. However, during continuous microbial Fe(III) reduction, Cd was immobilized by sorption to and/or coprecipitation within newly formed secondary minerals that contained Ca, Fe, and carbonate, implying the formation of an otavite-siderite-calcite (CdCO3-FeCO3-CaCO3) mixed mineral phase. Our data shows that microbially mediated turnover of Fe minerals affects the mobility of Cd in soils, potentially altering the dynamics of Cd uptake into food or phyto-remediating plants.

Visualization of Ca2+-Induced Phospholipid Domains

NASA Astrophysics Data System (ADS)

Haverstick, Doris M.; Glaser, Michael

1987-07-01

Large vesicles (5-15 μ m) were formed by hydrating a dried lipid film containing phospholipids labeled with a fluorophore in one fatty acid chain. By using a fluorescence microscope attached to a low-light-intensity charge-coupled-device camera and digital-image processor, the vesicles were easily viewed and initially showed uniform fluorescence intensity across the surface. The fluorescence pattern of vesicles made with a fluorophore attached to phosphatidylcholine or phosphatidylethanolamine was unaffected by the presence of divalent cations such as Ca2+, Mg2+, Mn2+, Zn2+, or Cd2+. The fluorescence pattern of vesicles containing a fluorophore attached to the acidic phospholipids phosphatidylserine or phosphatidic acid showed distinct differences when treated with Ca2+ or Cd2+, although they were unaffected by Mg2+, Mn2+, or Zn2+. Treatment with 2.0 mM Ca2+ or Cd2+ resulted in the movement of the fluorophore to a single large patch on the surface of the vesicle. When vesicles were formed in the presence of 33 mol% cholesterol, patching was seen at a slightly lower Ca2+ concentration (1.0 mM). The possibility of interactions between Ca2+ and acidic phospholipids in plasma membranes was investigated by labeling erythrocytes and erythrocyte ghosts with fluorescent phosphatidic acid. When Ca2+ was added, multiple (five or six) small patches were seen per individual cell. The same pattern was observed when vesicles formed from whole lipid extracts of erythrocytes were labeled with fluorescent phosphatidic acid and then treated with Ca2+. This shows that the size and distribution of the Ca2+-induced domains depend on phospholipid composition.

Optimized Ce:LiCAF amplifier pumping configurations

NASA Astrophysics Data System (ADS)

Cadatal-Raduban, Marilou; Pham, Minh Hong; Gabayno, Jacque Lynn; Yamanoi, Kohei; Empizo, Melvin John F.; Shimizu, Toshihiko; Sarukura, Nobuhiko; Nguyen, Hung Dai; Yoshikawa, Akira; Fukuda, Tsuguo

2018-02-01

Two side-pumping schemes suitable for the development of an ultraviolet femtosecond amplifier system using a Ce3+:LiCaAlF6 crystal are reported. Firstly, a Bethune-type prismatic cell configuration that uniformly illuminates the four sides of a micro-pulling down method-grown crystal is used to amplify 290 nm, femtosecond pulses with no significant increase in pulse duration and B-integral. The second pumping scheme uses a two-side-pumped large crystal. These two side-pumping schemes can pave new possibilities for achieving high-energy ultraviolet femtosecond pulses.

CD20+ T cell numbers are decreased in untreated HIV-1 patients and recover after HAART.

PubMed

Förster, Friederike; Singla, Anuj; Arora, Sunil K; Schmidt, Reinhold E; Jacobs, Roland

2012-08-30

To elucidate if CD20(+) T cells are affected by HIV-1 infection and may have a prognostic value for the course of disease, numbers of CD20(+) T cells were determined in healthy controls, untreated and HAART-treated HIV-1 patients. Coexpression patterns of CD4, CD8, and CD38 were analysed on CD3(+)CD20(+) and CD3(+)CD20(-) T cells. We found a significant decrease of CD20(+) T cell numbers in untreated HIV-1 patients (1.4%) as compared to healthy controls (2.5%) which recovered under HAART (1.9%). Particularly, the CD8(+) T cell compartment was affected revealing significant differences between healthy controls (3.4%) and both treated (1.7%) and untreated (1.1%) patients. CD38 was expressed on a few CD20(+) T cells but preferentially on CD20(-) cells in all three groups. IFN-γ production was measured upon cell activation using PMA alone or in combination with ionomycin in order to assess functional capacities of the cells. PMA alone was much more effective in CD20(+) cells regardless of CD38 coexpression, indicating a supportive role of CD20 but not CD38 in T cell activation. Here we present data showing that CD3(+)CD20(+) T cells are decreased in untreated HIV-1 patients and normal numbers are restored under HAART. Expression of CD20 and CD38 is independently regulated on T cells. Contrary to CD38, CD20 can substitute ionophores for Ca(2+) flux in early T cell activation and also strongly amplify cell stimulation in the presence of Ca(2+) ionophores, indicating that CD20 contributes to T cell activation. Copyright © 2012 Elsevier B.V. All rights reserved.

Materials Data on Ca(Ce2Se3)4 (SG:9) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-10

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

Materials Data on Ca(CeS2)2 (SG:122) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-10

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

Chronic endometritis in women with recurrent pregnancy loss and recurrent implantation failure: prevalence and role of office hysteroscopy and immunohistochemistry in diagnosis.

PubMed

Bouet, Pierre-Emmanuel; El Hachem, Hady; Monceau, Elise; Gariépy, Gilles; Kadoch, Isaac-Jacques; Sylvestre, Camille

2016-01-01

To determine the prevalence of chronic endometritis (CE) in patients with recurrent implantation failure (RIF) after IVF and unexplained recurrent pregnancy loss (RPL). Prospective observational study between November 2012 and March 2015. University-affiliated private IVF clinic. Women with RIF after IVF (group 1) and unexplained RPL (group 2). Office hysteroscopy followed by an endometrial biopsy was performed as part of the workup for RIF and RPL. The diagnosis of CE was histologically confirmed using immunohistochemistry stains for syndecan-1 (CD138). The prevalence of CE in each group and the sensitivity/specificity of office hysteroscopy in the diagnosis of CE. Ninety-nine patients were included (46 in group 1 and 53 in group 2). The mean age was 36.3 ± 4.9 years in group 1 and 34.5 ± 4.9 years in group 2. Five biopsies were uninterpretable (three in group 1 and two in group 2) because of insufficient specimen. The prevalence of CE was 14% (6/43) in group 1 and 27% (14/51) in group 2. The sensitivity and specificity of office hysteroscopy in the diagnosis of CE were 40% (8/20) and 80% (59/74), respectively. We found a high prevalence of immunohistochemically confirmed CE in women with RIF and RPL. Office hysteroscopy is a useful diagnostic tool but should be complemented by an endometrial biopsy for the diagnosis of CE. NCT01762098. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

The excessive enrichment of trace elements in migratory and breeding red-crowned cranes (Grus japonensis) in China.

PubMed

Jinming, Luo; Yongjie, Wang; Zhongyan, Gao; Wenfeng, Wang

2017-07-01

The excessive enrichment of trace elements, such as Pb and Cd, from food may contribute to the decline of migratory red-crowned cranes (Grus japonensis) in China. To test this prediction, we determined the concentrations of Pb and Cd, as well as further macro and trace elements (Ca, Mg, Cu, Zn) in the target species and their prey (sediment, reed root, mollusk, arthropods, and common fish species) in both the wintering (Yancheng wetland) and breeding sites (Zhalong wetland) of cranes in China. The maximum concentrations of Pb (130 mg kg -1 dry weight (dw)) and Cd (10.60 mg kg -1 dw) in the sediments of breeding site and the maximum concentration of Cd (4.50 mg kg -1 dw) in the sediments of wintering site exceeded the probable effect level values (91.30 mg kg -1 for Pb and 3.53 mg kg -1 for Cd), suggesting the potential exposure risk of the examined species. Indeed, Pb and Cd contents of essential foods, i.e., aquatic animals, sampled in two sites were above the limit of allowable concentration recommended by the Joint Food and Agriculture Organization of the United Nations/World Health Organization food standards program. Approximately 80, 31.4, and 60.3 mg kg -1 dw of Pb were detected in the eggshells, liver, and kidney, respectively, of the target species, and the values are above the levels of concern (1.7 mg kg -1 for eggshell and 30 mg kg -1 for liver and kidney) in common birds. Nevertheless, the increased Pb and Cd levels in the prey and bodies of the red-crowned cranes did not induce the levels of Ca and Mg depletion. Average contents of the macronutrients, Ca (1.38 g kg -1 dw) and Mg (1.32 g kg -1 dw), in the liver of the examined species exceeded the background concentrations (0.2-0.4 g kg -1 for Ca and 0.4-0.8 g kg -1 for Mg) in the liver of birds. Consumption of Ca-rich foods, e.g., grits and exoskeleton species, may aid in compensating the possible loss caused by the increased Pb and Cd concentrations in the bodies of the cranes.

Determining soil enzyme activities for the assessment of fungi and citric acid-assisted phytoextraction under cadmium and lead contamination.

PubMed

Mao, Liang; Tang, Dong; Feng, Haiwei; Gao, Yang; Zhou, Pei; Xu, Lurong; Wang, Lumei

2015-12-01

Microorganism or chelate-assisted phytoextraction is an effective remediation tool for heavy metal polluted soil, but investigations into its impact on soil microbial activity are rarely reported. Consequently, cadmium (Cd)- and lead (Pb)-resistant fungi and citric acid (CA) were introduced to enhance phytoextraction by Solanum nigrum L. under varied Cd and Pb pollution levels in a greenhouse pot experiment. We then determined accumulation of Cd and Pb in S. nigrum and the soil enzyme activities of dehydrogenase, phosphatase, urease, catalase, sucrase, and amylase. Detrended canonical correspondence analysis (DCCA) was applied to assess the interactions between remediation strategies and soil enzyme activities. Results indicated that the addition of fungi, CA, or their combination enhanced the root biomass of S. nigrum, especially at the high-pollution level. The combined treatment of CA and fungi enhanced accumulation of Cd about 22-47 % and of Pb about 13-105 % in S. nigrum compared with the phytoextraction alone. However, S. nigrum was not shown to be a hyperaccumulator for Pb. Most enzyme activities were enhanced after remediation. The DCCA ordination graph showed increasing enzyme activity improvement by remediation in the order of phosphatase, amylase, catalase, dehydrogenase, and urease. Responses of soil enzyme activities were similar for both the addition of fungi and that of CA. In summary, results suggest that fungi and CA-assisted phytoextraction is a promising approach to restoring heavy metal polluted soil.

Investigation of the structural, mechanical, dynamical and thermal properties of CsCaF3 and CsCdF3

NASA Astrophysics Data System (ADS)

Salmankurt, Bahadır; Duman, Sıtkı

2016-04-01

The structural, mechanical, dynamical and thermal properties of CsCaF3 and CsCdF3 are presented by using an ab initio pseudopotential method and a linear response scheme, within the generalized gradient approximation. The obtained structural and mechanical properties are in good agreement with other available theoretical and experimental studies. The calculated elastic constants of these materials obey the cubic stability conditions. It has been found that CsCaF3 is brittle whereas CsCdF3 has ductile manner. The full phonon dispersion curves of these materials are reported for the first time in the literature. We have found that calculated phonon modes are positive along the all symmetry directions, indicating that these materials are dynamically stable at the cubic structure. The obtained zone-center phonon modes for CsCaF3 (IR data) are found to be 83 (98) cm-1, 104 (115) cm-1, 120 cm-1, 180 (192) cm-1, 231 (250.5) cm-1, 361 (374) cm-1, 446 (449) cm-1. Also, we have calculated internal energy, Helmholtz free energy, constant-volume specific heat, entropy and Debye temperature as function of temperature. At the 300 K, specific heats are calculated to be 113.36 J mol-1 K-1 and 115.58 J mol-1 K-1 for CsCaF3 and CsCdF3 ,respectively, which are lower than Doulong-Petit limit (12 472 J mol-1 K-1).

Ocean acidification increases cadmium accumulation in marine bivalves: a potential threat to seafood safety.

PubMed

Shi, Wei; Zhao, Xinguo; Han, Yu; Che, Zhumei; Chai, Xueliang; Liu, Guangxu

2016-01-21

To date, the effects of ocean acidification on toxic metals accumulation and the underlying molecular mechanism remains unknown in marine bivalve species. In the present study, the effects of the realistic future ocean pCO2 levels on the cadmium (Cd) accumulation in the gills, mantle and adductor muscles of three bivalve species, Mytilus edulis, Tegillarca granosa, and Meretrix meretrix, were investigated. The results obtained suggested that all species tested accumulated significantly higher Cd (p < 0.05) in the CO2 acidified seawater during the 30 days experiment and the health risk of Cd (based on the estimated target hazard quotients, THQ) via consumption of M. meretrix at pH 7.8 and 7.4 significantly increased 1.21 and 1.32 times respectively, suggesting a potential threat to seafood safety. The ocean acidification-induced increase in Cd accumulation may have occurred due to (i) the ocean acidification increased the concentration of Cd and the Cd(2+)/Ca(2+) in the seawater, which in turn increased the Cd influx through Ca channel; (ii) the acidified seawater may have brought about epithelia damage, resulting in easier Cd penetration; and (iii) ocean acidification hampered Cd exclusion.

Ocean acidification increases cadmium accumulation in marine bivalves: a potential threat to seafood safety

PubMed Central

Shi, Wei; Zhao, Xinguo; Han, Yu; Che, Zhumei; Chai, Xueliang; Liu, Guangxu

2016-01-01

To date, the effects of ocean acidification on toxic metals accumulation and the underlying molecular mechanism remains unknown in marine bivalve species. In the present study, the effects of the realistic future ocean pCO2 levels on the cadmium (Cd) accumulation in the gills, mantle and adductor muscles of three bivalve species, Mytilus edulis, Tegillarca granosa, and Meretrix meretrix, were investigated. The results obtained suggested that all species tested accumulated significantly higher Cd (p < 0.05) in the CO2 acidified seawater during the 30 days experiment and the health risk of Cd (based on the estimated target hazard quotients, THQ) via consumption of M. meretrix at pH 7.8 and 7.4 significantly increased 1.21 and 1.32 times respectively, suggesting a potential threat to seafood safety. The ocean acidification-induced increase in Cd accumulation may have occurred due to (i) the ocean acidification increased the concentration of Cd and the Cd2+/Ca2+ in the seawater, which in turn increased the Cd influx through Ca channel; (ii) the acidified seawater may have brought about epithelia damage, resulting in easier Cd penetration; and (iii) ocean acidification hampered Cd exclusion. PMID:26795597

Promotional effect of Al2O3 on WO3/CeO2-ZrO2 monolithic catalyst for selective catalytic reduction of nitrogen oxides with ammonia after hydrothermal aging treatment

NASA Astrophysics Data System (ADS)

Xu, Haidi; Liu, Shuang; Wang, Yun; Lin, Qingjin; Lin, Chenlu; Lan, Li; Wang, Qin; Chen, Yaoqiang

2018-01-01

Hydrothermal stability of catalysts for selective catalytic reduction of NOx with NH3 (NH3-SCR) has always been recognized as a challenge in development of candidate catalysts for applications in diesel engine emissions. In this study, Al2O3 was introduced into CeO2-ZrO2 to improve the NH3-SCR activity of WO3/CeO2-ZrO2 after hydrothermal aging (HA) treatment at 800 °C for 12 h. The activity results indicated that the NH3-SCR activity of WO3/CeO2-ZrO2-HA was obviously improved in the whole reaction temperature range after doping Al2O3 into CeO2-ZrO2, for example, the average and maximum NOx conversion were separately increased by ca. 20% and 25% after HA treatment. XRD, Raman, TEM and EDX results revealed that the introduction of Al2O3 inhibited the sintering and agglomeration of CeO2-ZrO2 and WO3 and the formation of Ce2(WO4)3 after HA treatment. Accordingly, WO3/CeO2-ZrO2-Al2O3-HA showed remarkably improved structural stability and reducibility, increased surface acidity, and facilitated the reactivity between adsorbed NH3 and nitrate species, which together contributed to its better catalytic performance after hydrothermal aging treatment.

Determination of the Complex Elastic Moduli of Materials Using A Free- Free Bar Technique

DTIC Science & Technology

1994-03-01

LCDR, Dr. D. L alner 1 Dept. of Physics (Code PH) Naval Postgrdumt School Monterey, CA 93943 10 . Cgimd Ofric. Naval Reserh Labrary ATI’N: Dr. N...Postgraduate School ( fAp~hicbl) Naval Postgraduate School 6c. ADDRESS MclY- $Mae, 02t c7;w 3 7b. ADDRESS (city, MUk and ii? code) Mogntere CA 93943-5=0...Monery CA 93943-5000 Sa. NAME OF FUNDDOISIONS0R]NG G. OFMiCE SYMBOL 9. FUU1ENIICMN IDTFCTONNUMBER ORGANUAT1ON j (If Appkiabie) NSWC. CRANE. NPS

UV-emitting phosphors: synthesis, photoluminescence and applications

NASA Astrophysics Data System (ADS)

Thakare, D. S.; Omanwar, S. K.; Muthal, P. L.; Dhopte, S. M.; Kondawar, V. K.; Moharil, S. V.

2004-02-01

UV-emitting phosphors find uses in various applications, such as photocopying, phototherapy, sun tanning, etc. The phosphor requirements for these applications vary. Simple methods for preparing different UV-emitting phosphors are described. Novel syntheses for some borates (SrB4O7:Eu, CeMgB5O10:Gd, GdBO3:Pr, LaB3O6:Ce,Bi, LaB3O6:Gd,Bi, LaB3O6:Ce, Ba2B5O9Cl:Eu), a silicate (Ba2SiO5:Pb), phosphates (Sr2-xMgxP2O7:Eu) and a sulphate (CaSO4:Eu) are reported. Photoluminescence spectra of the phosphors so prepared are presented and discussed in the context of applications like phototherapy and photocopying lamps, photoluminescent liquid crystal displays, radiophotoluminescence, etc.

Geochemistry of K/T-boundary Chicxulub ejecta of NE-Mexico

NASA Astrophysics Data System (ADS)

Harting, M.; Deutsch, A.; Rickers, K.

2003-12-01

Many K/T sections all over the world contain impact spherules supposed related to the Chicxulub event. This study focus on ejecta layers in NE-Mexican profiles. We carried out systematic XRF and synchrotron radiation measurements on such spherules at the HASYLAB and ANKA facilities as well as microprobe analyses (CAMECA SX50). Area scans on tektite-like material of the Bochil section reveal a pronounced zonation in the inner part, dominated by Ba and Sr whereas secondary CaCO3 dominates in the altered margin. The composition of the spherules from the Mesa-Juan Perez section differ significantly from the Beloc (Haiti) and Bochil tektite glasses. At Mesa-Juan Perez, spherules are either extremely rich in Fe and Ca or consist of smectite, some of those carry carbonate inclusions. Yttrium, La and Ce are zoned within the smectite with concentrations below the detection limit and up to 20 æg/g The Ca-rich inclusions are enriched in Y (up to 35 æg/g) and La (18 æg/g) and, compared to the surrounding smectite, also in Ce (up to 34 æg/g). The Ce enrichment in spherules from the Mesa-Juan Perez section indicates impact-melted carbonates of the Yucatan carbonate platform as possible precursor rocks. Recent investigations focus on the chemistry of melt rock samples from the PEMEX wells Yucatan-6 and Chicxulub-1: Their average composition (mean of 250 data points in wt-percent ) is 61.6 for SiO2, 0.16 for TiO2, 18.07 for Al2O3, 0.01 for Cr2O3, 1.98 for Na2O, 1.5 for FeO, 0.05 for MnO, 0.01 for NiO, 0.31 for MgO, 9.14 for K2O, 3.44 for CaO, and 0.01 for SO2. These results are in some cases comparable to the geochemistry of ejecta glasses, e.g. from Beloc (Haiti).

Lactate-H+ Transport Is a Significant Component of the In Vivo Corneal Endothelial Pump

PubMed Central

Nguyen, Tracy T.; Bonanno, Joseph A.

2012-01-01

Purpose. To confirm the expression of monocarboxylate transporters (MCT) 1, 2, and 4 in rabbit CE and to test the hypothesis that cellular buffering contributed by HCO3−, NBCe1, and carbonic anhydrase (CA) activity facilitates lactate-H+ efflux thereby controlling corneal hydration in vivo. Methods. MCT1–4 expression of rabbit endothelium was examined by Western blotting and immunofluorescence staining. Lactate-induced acidification (LIA) was measured in perfused CE in the presence and absence of HCO3− and acetazolamide (ACTZ) using tissue treated with siRNA specific to MCT1, 2, and 4. Corneal thickness and lactate concentration were measured in New Zealand White rabbits treated with the topical CA inhibitor Azopt, and from eyes that were injected intracamerally with ouabain, disodium 4,4′-diisothiocyanatostilbene-2,2′-disulfonate (DIDS), and shRNA specific to the 1Na+:2HCO3− cotransporter NBCe1. Results. MCT1 and MCT4 are localized to the lateral membrane, while MCT2 is apical. Cell pH measurements showed LIA in response to 40 mM lactate in bicarbonate free (BF) Ringer's that was inhibited by niflumic acid and by MCT siRNA knockdown, and significantly reduced in the presence of HCO3−. Lactate-dependent proton flux in vitro was not significantly greater in the presence of HCO3− or reduced by ACTZ. However, when active transport, NBCe1, or CA activity was disrupted in vivo, corneal edema ensued and was associated with significant corneal lactate accumulation. Conclusions. MCT1, 2, and 4 are expressed in rabbit CE on both the apical and basolateral surfaces and function to transport lactate-H+. Lactate-H+ flux is facilitated by active transport, HCO3− transport and CA activity, disruption of which causes corneal edema in vivo and indicates that facilitation of lactate efflux is a component of the endothelial pump. PMID:22410572

Toxic metal interactions affect the bioaccumulation and dietary intake of macro- and micro-nutrients.

PubMed

Khan, Anwarzeb; Khan, Sardar; Alam, Mehboob; Khan, Muhammad Amjad; Aamir, Muhammad; Qamar, Zahir; Ur Rehman, Zahir; Perveen, Sajida

2016-03-01

The present study was conducted to evaluate the effects of heavy metals (cadmium (Cd), lead (Pb) and Cd-Pb mix) on bioaccumulation of different nutrients. Three plant species including potato, tomato and lettuce were grown in pots containing soil contaminated with Cd, Pb and Cd-Pb mix at four different levels. The edible portions of each plant were analysed for Cd, Pb and different macro- and micro-nutrients including protein, vitamin C, nitrogen (N), phosphorous (P), potassium (K), iron (Fe), manganese (Mn), calcium (Ca) and magnesium (Mg). Results indicated significant variations in selected elemental concentrations in all the three plants grown in different treatments. The projected daily dietary intake values of selected metals were significant (P < 0.001) for Fe, Mn, Ca and Mg but not significant for protein, vitamin C, N and P. The elemental contribution to Recommended Dietary Allowance (RDA) was significant for Mn. Similarly, Fe and Mg also showed substantial contribution to RDA, while Ca, N, P, K, protein and vitamin C showed the minimal contribution for different age groups. This study suggests that vegetables cultivated on Cd and Pb contaminated soil may significantly affect their quality, and the consumption of such vegetables may result in substantial negative effects on nutritional composition of the consumer body. Long term and continuous use of contaminated vegetables may result in malnutrition. Copyright © 2015 Elsevier Ltd. All rights reserved.

Anomalous Alkali-Olivine Basalts Associated with Arc-related Late Cenozoic Volcanism in Southern Hispaniola

NASA Astrophysics Data System (ADS)

Lewis, J.; Perfit, M. R.; Kamenov, G.

2006-12-01

Several eruptive centers of Pliocene-Quaternary age occur across southern Hispaniola that constitutes the youngest land-based magmatic activity in the Greater Antilles. Two main rock suites can be delineated based on petrography, geochemistry and location. The older larger centers in the Dominican Republic (DR) consist of basalts (45.81-53% SiO2 with TiO2 <1.2%), basaltic andesites and trachybasalts (54-55% SiO2) and trachyandesites (56-62% SiO2). These constitute a consanguineous high-K calc-alkaline (CA) series. Younger centers of Quaternary age (all probably < 1.0 Ma) occur to the west in Haiti, at San Juan de la Maguana (DR) and two small centers to the south of Yayas de Viajama (DR). The rocks are alkali-olivine basalts, limburgites and nephelenites (38.6-47.6% SiO2 with TiO2 >1.7 at MgO<12%) and are termed the mafic alkaline (MA) series. Although there is an overall similarity in the trace and minor element patterns of normalized multi-element plots of the rocks samples the CA series shows distinct depletions in the HFS elements Ta, Nb, Hf, Zr, and Ti compared to lavas in the MA series. MA series samples exhibit strong enrichment in LREE (Ce/Ybn = > 30) compared to the CA series basalts (Ce/Ybn = < 30) and greater HREE depletions. The CA suite has higher 143Nd/144Nd (0.51286 ? 0.5126) and lower 87Sr/86Sr (0.7040 ? 0.7053) than the MA suite (0.5126-0.51196; 0.7063- 0.7078). MA series lavas have unusually non-radiogenic Pb isotopic values (206Pb/204Pb < 17.9) whereas the CA suite has low but values more typical of the Greater Antilles. Incompatible trace element ratios such as Ba/Nb, Sr/Nd, Ce/Yb and Ba/La are well correlated with isotopes but the data form near continuous arrays suggesting mixing between sources. The data suggest the young alkaline lavas are derived from enriched mantle source similar to EM1 but that they are also mixing with a component reflected in the composition of the CA series that is related to previous subduction- related enrichment of the sub-arc mantle beneath Hispaniola. The presence of an EM1 component in the Greater Antilles has not been previously recognized and is unusual for an arc environment.

U.S. EPA, Pesticide Product Label, RCI CHLOROPHEN 49-411, 10/05/1972

EPA Pesticide Factsheets

2011-04-14

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The Tat Inhibitor Didehydro-Cortistatin A Prevents HIV-1 Reactivation from Latency

PubMed Central

Mousseau, Guillaume; Kessing, Cari F.; Fromentin, Rémi; Trautmann, Lydie; Chomont, Nicolas

2015-01-01

ABSTRACT Antiretroviral therapy (ART) inhibits HIV-1 replication, but the virus persists in latently infected resting memory CD4+ T cells susceptible to viral reactivation. The virus-encoded early gene product Tat activates transcription of the viral genome and promotes exponential viral production. Here we show that the Tat inhibitor didehydro-cortistatin A (dCA), unlike other antiretrovirals, reduces residual levels of viral transcription in several models of HIV latency, breaks the Tat-mediated transcriptional feedback loop, and establishes a nearly permanent state of latency, which greatly diminishes the capacity for virus reactivation. Importantly, treatment with dCA induces inactivation of viral transcription even after its removal, suggesting that the HIV promoter is epigenetically repressed. Critically, dCA inhibits viral reactivation upon CD3/CD28 or prostratin stimulation of latently infected CD4+ T cells from HIV-infected subjects receiving suppressive ART. Our results suggest that inclusion of a Tat inhibitor in current ART regimens may contribute to a functional HIV-1 cure by reducing low-level viremia and preventing viral reactivation from latent reservoirs. PMID:26152583

All Prime Contract Awards by State or Country, Place, and Contractor, FY 84. Part 7 (Aberdeen, Maryland - Wrentham, Massachusetts).

DTIC Science & Technology

1984-01-01

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CD4+CD25+ regulatory T cells suppress mast cell degranulation and allergic responses through OX40-OX40L interaction

PubMed Central

Gri, Giorgia; Piconese, Silvia; Frossi, Barbara; Manfroi, Vanessa; Merluzzi, Sonia; Tripodo, Claudio; Viola, Antonella; Odom, Sandra; Rivera, Juan; Colombo, Mario P.; Pucillo, Carlo E.

2008-01-01

Summary CD4+CD25+ T regulatory cells (Tregs) play a central role in the suppression of immune responses thus serving to induce tolerance and to control persistent immune responses that can lead to autoimmunity. Here we explore if Tregs also play a role in controlling the immediate hypersensitivity response of mast cells (MCs). Tregs directly inhibit the FcεRI-dependent degranulation of MCs through cell-cell contact involving OX40-OX40L interactions between Tregs and MCs, respectively. MCs show increased cAMP levels and reduced Ca2+ influx, independent of PLC-γ2 or Ca2+ release from intracellular stores. Antagonism of cAMP in MCs reverses the inhibitory effects of Tregs restoring normal Ca2+ responses and degranulation. Importantly, the in vivo depletion or inactivation of Tregs causes enhancement of the anaphylactic response. The demonstrated cross-talk between Tregs and MCs defines a previously unrecognized mechanism controlling MCs degranulation. Loss of this interaction may contribute to the severity of allergic responses. PMID:18993084

CE Needs in Geriatrics and Gerontology for Selected Health Professionals.

ERIC Educational Resources Information Center

Robinson, Betsy C.

1981-01-01

Describes a needs assessment model that offers practical suggestions to program planners in a multidisciplinary area of inquiry that is relatively new to continuing education in health sciences. (Available from University of California Press, Berkeley, CA 94720.) (Author/CT)

Influence of the baking process for chemically amplified resist on CD performance

NASA Astrophysics Data System (ADS)

Sasaki, Shiho; Ohfuji, Takeshi; Kurihara, Masa-aki; Inomata, Hiroyuki; Jackson, Curt A.; Murata, Yoshio; Totsukawa, Daisuke; Tsugama, Naoko; Kitano, Naoki; Hayashi, Naoya; Hwang, David H.

2002-12-01

CD uniformity and MTT (Mean to Target) control are very important in mask production for the 90nm node and beyond. Although it is well known that baking temperatures influence CD control in the CAR (chemically amplified resist) process for mask patterning, we found that 2 other process factors, which are related to acid diffusion and CA- reaction, greatly affect CD performance. We used a commercially available, negative CAR material and a 50kV exposure tool. We focused on the baking process for both PB (Pre Baking) and PEB (Post Exposure Bake). Film densification strength was evaluated from film thickness loss during PB. Plate temperature distribution was monitored with a thermocouple plate and IR camera. CA-reactions were also monitored with in-situ FTIR during PEB. CD uniformity was used to define the process influence. In conclusion, we found that airflow control and ramping temperature control in the baking process are very important factors to control CD in addition to conventional temperature control. These improvements contributed to a 30 % of reduction in CD variation.

Virus-like particle-based vaccine against coxsackievirus A6 protects mice against lethal infections.

PubMed

Shen, Chaoyun; Ku, Zhiqiang; Zhou, Yu; Li, Dapeng; Wang, Lili; Lan, Ke; Liu, Qingwei; Huang, Zhong

2016-07-25

Coxsackievirus A6 (CA6) is emerging as one of the major causative agents of hand, foot, and mouth disease (HFMD) worldwide. However, no vaccine is currently available for preventing CA6 infection. Here, we report the development of a virus-like particle (VLP)-based recombinant vaccine for CA6. We produced CA6 VLPs in insect cells by infecting the cells with a baculovirus coexpressing the genes encoding CA6 P1 and 3CD. Biochemical analyses showed that the produced VLPs consisted of VP0, VP1, and VP3 capsid subunit proteins generated by the cleavage of P1 by 3CD. Mice immunized with these VLPs produced CA6-specific serum antibodies. Passive transfer of antisera from CA6 VLP-immunized mice protected recipient mice from lethal infections caused by homologous and heterologous CA6 strains. Moreover, active immunization of mice with CA6 VLPs efficiently conferred protection against both homologous and heterologous CA6 infections. These results suggested that CA6 VLP-based recombinant vaccine is a promising candidate vaccine for preventing CA6 infection and can be incorporated into a multivalent HFMD vaccine formulation to achieve broad-spectrum and effective prevention of this disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

An ultra-sensitive impedimetric immunosensor for detection of the serum oncomarker CA-125 in ovarian cancer patients

NASA Astrophysics Data System (ADS)

Johari-Ahar, M.; Rashidi, M. R.; Barar, J.; Aghaie, M.; Mohammadnejad, D.; Ramazani, A.; Karami, P.; Coukos, G.; Omidi, Y.

2015-02-01

Effective treatment of ovarian cancer depends upon the early detection of the malignancy. Here, we report on the development of a new nanostructured immunosensor for early detection of cancer antigen 125 (CA-125). A gold electrode was modified with mercaptopropionic acid (MPA), and then consecutively conjugated with silica coated gold nanoparticles (AuNP@SiO2), CdSe quantum dots (QDs) and anti-CA-125 monoclonal antibody (mAb). The engineered MPA|AuNP@SiO2|QD|mAb immunosensor was characterised using transmission electron microscopy (TEM), atomic force microscopy (AFM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Successive conjugation of AuNP@SiO2, CdSe QD and anti-CA-125 mAb onto the gold electrode resulted in sensitive detection of CA-125 with a limit of detection (LOD) of 0.0016 U mL-1 and a linear detection range (LDR) of 0-0.1 U mL-1. Based on the high sensitivity and specificity of the immunosensor, we propose this highly stable and reproducible biosensor for the early detection of CA-125.Effective treatment of ovarian cancer depends upon the early detection of the malignancy. Here, we report on the development of a new nanostructured immunosensor for early detection of cancer antigen 125 (CA-125). A gold electrode was modified with mercaptopropionic acid (MPA), and then consecutively conjugated with silica coated gold nanoparticles (AuNP@SiO2), CdSe quantum dots (QDs) and anti-CA-125 monoclonal antibody (mAb). The engineered MPA|AuNP@SiO2|QD|mAb immunosensor was characterised using transmission electron microscopy (TEM), atomic force microscopy (AFM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Successive conjugation of AuNP@SiO2, CdSe QD and anti-CA-125 mAb onto the gold electrode resulted in sensitive detection of CA-125 with a limit of detection (LOD) of 0.0016 U mL-1 and a linear detection range (LDR) of 0-0.1 U mL-1. Based on the high sensitivity and specificity of the immunosensor, we propose this highly stable and reproducible biosensor for the early detection of CA-125. Electronic supplementary information (ESI) available: Additional materials including Figures and discussion as described in the text. See DOI: 10.1039/c4nr06687a

Predicting plant uptake of cadmium: validated with long-term contaminated soils.

PubMed

Lamb, Dane T; Kader, Mohammed; Ming, Hui; Wang, Liang; Abbasi, Sedigheh; Megharaj, Mallavarapu; Naidu, Ravi

2016-10-01

Cadmium accumulates in plant tissues at low soil loadings and is a concern for human health. Yet at higher levels it is also of concern for ecological receptors. We determined Cd partitioning constants for 41 soils to examine the role of soil properties controlling Cd partitioning and plant uptake. From a series of sorption and dose response studies, transfer functions were developed for predicting Cd uptake in Cucumis sativa L. (cucumber). The parameter log K f was predicted with soil pH ca , logCEC and log OC. Transfer of soil pore-water Cd 2+ to shoots was described with a power function (R 2  = 0.73). The dataset was validated with 13 long-term contaminated soils (plus 2 control soils) ranging in Cd concentration from 0.2 to 300 mg kg -1 . The series of equations predicting Cd shoot from pore-water Cd 2+ were able to predict the measured data in the independent dataset (root mean square error = 2.2). The good relationship indicated that Cd uptake to cucumber shoots could be predicted with Cd pore and Cd 2+ without other pore-water parameters such as pH or Ca 2+ . The approach may be adapted to a range of plant species.

Growth of mature boreal Norway spruce was not affected by elevated [CO(2)] and/or air temperature unless nutrient availability was improved.

PubMed

Sigurdsson, Bjarni D; Medhurst, Jane L; Wallin, Göran; Eggertsson, Olafur; Linder, Sune

2013-11-01

The growth responses of mature Norway spruce (Picea abies (L.) Karst.) trees exposed to elevated [CO(2)] (CE; 670-700 ppm) and long-term optimized nutrient availability or elevated air temperature (TE; ±3.9 °C) were studied in situ in northern Sweden in two 3 year field experiments using 12 whole-tree chambers in ca. 40-year-old forest. The first experiment (Exp. I) studied the interactions between CE and nutrient availability and the second (Exp. II) between CE and TE. It should be noted that only air temperature was elevated in Exp. II, while soil temperature was maintained close to ambient. In Exp. I, CE significantly increased the mean annual height increment, stem volume and biomass increment during the treatment period (25, 28, and 22%, respectively) when nutrients were supplied. There was, however, no significant positive CE effect found at the low natural nutrient availability. In Exp. II, which was conducted at the natural site fertility, neither CE nor TE significantly affected height or stem increment. It is concluded that the low nutrient availability (mainly nitrogen) in the boreal forests is likely to restrict their response to the continuous rise in [CO(2)] and/or TE.

Compositional variation in minerals of the chevkinite group

USGS Publications Warehouse

Macdonald, R.; Belkin, H.E.

2002-01-01

The composition of chevkinite and perrierite, the most common members of the chevkinite group, is closely expressed by the formula A4BC2D2Si4O22, where A = (La,Ce,Ca,Sr,Th), B = Fe2+, C = (Fe2+,Fe3+,Ti,Al,Zr,Nb) and D = Ti. The A site is dominated by a strong negative correlation between (Ca+Sr) and the REE. Chondrite-normalized REE patterns are very variable, e.g. in LREE/HREE and Eu/Eu*. The C site is dominated by Ti, Al and Fe2+, in very variable proportions. Most chevkinites and perrierites are close to stoichiometric, with cation sums between 12.9 and 13.5, compared to the theoretical 13. There is no single, generally applicable charge balancing substitution scheme in the group; however, the general relationship (Ca+Sr)A + TiC + REEA + M3C+2+ defines a linear array with r2 = 0.91. Chevkinite and perrierite are shown to be compositionally distinct on the basis of CaO, FeO* Al2O3 and Ce2O3 abundances. Chevkinite forms mainly in chemically evolved parageneses, such as syenites, rhyolites and fenites associated with carbonatite complexes. Perrierite is more commonly recorded from igneous rocks of mafic to intermediate composition. The compositional characteristics and possible structural formulae of other members of the chevkinite group are reviewed briefly.

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

Choi, Hong Seo; Lee, Hyun Min; Kim, Won-Tae

Highlights: • This study generates a monoclonal antibody CA27 against the mycoplasmal p37 protein. • CA27 isolates circulating tumor cells (CTCs) from the blood of liver cancer patients. • Results show the first evidence for mycoplasma infected-CTCs in cancer patients. - Abstract: Many studies have shown that persistent infections of bacteria promote carcinogenesis and metastasis. Infectious agents and their products can modulate cancer progression through the induction of host inflammatory and immune responses. The presence of circulating tumor cells (CTCs) is considered as an important indicator in the metastatic cascade. We unintentionally produced a monoclonal antibody (MAb) CA27 against themore » mycoplasmal p37 protein in mycoplasma-infected cancer cells during the searching process of novel surface markers of CTCs. Mycoplasma-infected cells were enriched by CA27-conjugated magnetic beads in the peripheral blood mononuclear cells in patients with hepatocellular carcinoma (HCC) and analyzed by confocal microscopy with anti-CD45 and CA27 antibodies. CD45-negative and CA27-positive cells were readily detected in three out of seven patients (range 12–30/8.5 ml blood), indicating that they are mycoplasma-infected circulating epithelial cells. CA27-positive cells had larger size than CD45-positive hematological lineage cells, high nuclear to cytoplasmic ratios and irregular nuclear morphology, which identified them as CTCs. The results show for the first time the existence of mycoplasma-infected CTCs in patients with HCC and suggest a possible correlation between mycoplasma infection and the development of cancer metastasis.« less

Pericellular activation of proMMP-7 (promatrilysin-1) through interaction with CD151.

PubMed

Shiomi, Takayuki; Inoki, Isao; Kataoka, Fumio; Ohtsuka, Takashi; Hashimoto, Gakuji; Nemori, Ryoichi; Okada, Yasunori

2005-12-01

Matrix metalloproteinase-7 (MMP-7) (also known as matrilysin-1) is secreted as a proenzyme (proMMP-7) and plays a key role in the degradation of various extracellular matrix (ECM) and non-ECM molecules after activation. To identify the binding proteins related to proMMP-7 activation, a human lung cDNA library was screened by yeast two-hybrid system using proMMP-7 as bait. We identified a candidate molecule CD151, which is a member of the transmembrane 4 superfamily. Complex formation of proMMP-7 with CD151 was demonstrated by immunoprecipitation of the molecules from CaR-1 cells, a human rectal carcinoma cell line, expressing both proMMP-7 and CD151, and CD151 stable transfectants incubated with proMMP-7. Yeast two-hybrid assays using deletion mutants of proMMP-7 and CD151 suggested an interaction between the propeptide of proMMP-7 and the COOH-terminal extracellular loop of CD151. The binding activity of (125)I-labeled proMMP-7 to CD151 on the cell membranes was shown with CD151 stable transfectants. Laser-scanning confocal microscopy demonstrated that proMMP-7 colocalizes with CD151 on the cell membranes of CD151 stable transfectants and CaR-1 cells. In situ zymography using crosslinked carboxymethylated transferrin, a substrate of MMP-7, demonstrated proteinase activity on and around CD151 stable transfectants and CaR-1 cells, while the activity was abolished by their treatment with MMP inhibitors, anti-MMP-7 antibody or anti-CD151 antibody. In human lung adenocarcinoma tissues, colocalization of MMP-7 and CD151 was demonstrated on the carcinoma cells. Metalloproteinase activity was present in these tissues and could be inhibited by antibodies to MMP-7 or CD151. These data demonstrate for the first time that proMMP-7 is captured and activated on the cell membranes through interaction with CD151, and suggest the possibility that similar to the MT1-MMP/MMP-2 system, MMP-7 is involved in the pericellular activation mechanism mediated by CD151, a crucial step in proteolysis on the cell membranes under various pathophysiological conditions including cancer invasion and metastasis.

Physiological Levels of Pik3ca H1047R Mutation in the Mouse Mammary Gland Results in Ductal Hyperplasia and Formation of ERα-Positive Tumors

PubMed Central

Tikoo, Anjali; Roh, Vincent; Montgomery, Karen G.; Ivetac, Ivan; Waring, Paul; Pelzer, Rebecca; Hare, Lauren; Shackleton, Mark; Humbert, Patrick; Phillips, Wayne A.

2012-01-01

PIK3CA, the gene coding for the p110α subunit of phosphoinositide 3-kinase, is frequently mutated in a variety of human tumors including breast cancers. To better understand the role of mutant PIK3CA in the initiation and/or progression of breast cancer, we have generated mice with a conditional knock-in of the common activating mutation, Pik3caH1047R, into one allele of the endogenous gene in the mammary gland. These mice developed a ductal anaplasia and hyperplasia by 6 weeks of age characterized by multi-layering of the epithelial lining of the mammary ducts and expansion of the luminal progenitor (Lin−; CD29lo; CD24+; CD61+) cell population. The Pik3caH1047R expressing mice eventually develop mammary tumors with 100% penetrance but with a long latency (>12 months). This is significantly longer than has been reported for transgenic models where expression of the mutant Pik3ca is driven by an exogenous promoter. Histological analysis of the tumors formed revealed predominantly ERα-positive fibroadenomas, carcinosarcomas and sarcomas. In vitro induction of Pik3caH1047R in immortalized mammary epithelial cells also resulted in tumor formation when injected into the mammary fat pad of immunodeficient recipient mice. This novel model, which reproduces the scenario of a heterozygous somatic mutation occurring in the endogenous PIK3CA gene, will thus be a valuable tool for investigating the role of Pik3caH1047R mutation in mammary tumorigenesis both in vivo and in vitro. PMID:22666336

Nicotinic Acid Adenine Dinucleotide Phosphate Plays a Critical Role in Naive and Effector Murine T Cells but Not Natural Regulatory T Cells.

PubMed

Ali, Ramadan A; Camick, Christina; Wiles, Katherine; Walseth, Timothy F; Slama, James T; Bhattacharya, Sumit; Giovannucci, David R; Wall, Katherine A

2016-02-26

Nicotinic acid adenine dinucleotide phosphate (NAADP), the most potent Ca(2+) mobilizing second messenger discovered to date, has been implicated in Ca(2+) signaling in some lymphomas and T cell clones. In contrast, the role of NAADP in Ca(2+) signaling or the identity of the Ca(2+) stores targeted by NAADP in conventional naive T cells is less clear. In the current study, we demonstrate the importance of NAADP in the generation of Ca(2+) signals in murine naive T cells. Combining live-cell imaging methods and a pharmacological approach using the NAADP antagonist Ned-19, we addressed the involvement of NAADP in the generation of Ca(2+) signals evoked by TCR stimulation and the role of this signal in downstream physiological end points such as proliferation, cytokine production, and other responses to stimulation. We demonstrated that acidic compartments in addition to the endoplasmic reticulum were the Ca(2+) stores that were sensitive to NAADP in naive T cells. NAADP was shown to evoke functionally relevant Ca(2+) signals in both naive CD4 and naive CD8 T cells. Furthermore, we examined the role of this signal in the activation, proliferation, and secretion of effector cytokines by Th1, Th2, Th17, and CD8 effector T cells. Overall, NAADP exhibited a similar profile in mediating Ca(2+) release in effector T cells as in their counterpart naive T cells and seemed to be equally important for the function of these different subsets of effector T cells. This profile was not observed for natural T regulatory cells. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Nicotinic Acid Adenine Dinucleotide Phosphate Plays a Critical Role in Naive and Effector Murine T Cells but Not Natural Regulatory T Cells*

PubMed Central

Ali, Ramadan A.; Camick, Christina; Wiles, Katherine; Walseth, Timothy F.; Slama, James T.; Bhattacharya, Sumit; Giovannucci, David R.; Wall, Katherine A.

2016-01-01

Nicotinic acid adenine dinucleotide phosphate (NAADP), the most potent Ca2+ mobilizing second messenger discovered to date, has been implicated in Ca2+ signaling in some lymphomas and T cell clones. In contrast, the role of NAADP in Ca2+ signaling or the identity of the Ca2+ stores targeted by NAADP in conventional naive T cells is less clear. In the current study, we demonstrate the importance of NAADP in the generation of Ca2+ signals in murine naive T cells. Combining live-cell imaging methods and a pharmacological approach using the NAADP antagonist Ned-19, we addressed the involvement of NAADP in the generation of Ca2+ signals evoked by TCR stimulation and the role of this signal in downstream physiological end points such as proliferation, cytokine production, and other responses to stimulation. We demonstrated that acidic compartments in addition to the endoplasmic reticulum were the Ca2+ stores that were sensitive to NAADP in naive T cells. NAADP was shown to evoke functionally relevant Ca2+ signals in both naive CD4 and naive CD8 T cells. Furthermore, we examined the role of this signal in the activation, proliferation, and secretion of effector cytokines by Th1, Th2, Th17, and CD8 effector T cells. Overall, NAADP exhibited a similar profile in mediating Ca2+ release in effector T cells as in their counterpart naive T cells and seemed to be equally important for the function of these different subsets of effector T cells. This profile was not observed for natural T regulatory cells. PMID:26728458

CdSe/ZnS Quantum Dot-Labeled Lateral Flow Strips for Rapid and Quantitative Detection of Gastric Cancer Carbohydrate Antigen 72-4

NASA Astrophysics Data System (ADS)

Yan, Xinyu; Wang, Kan; Lu, Wenting; Qin, Weijian; Cui, Daxiang; He, Jinghua

2016-03-01

Carbohydrate antigen 72-4 (CA72-4) is an important biomarker associated closely with diagnosis and prognosis of early gastric cancer. How to realize quick, sensitive, specific, and quantitative detection of CA72-4 in clinical specimens has become a great requirement. Herein, we reported a CdSe/ZnS quantum dot-labeled lateral flow test strip combined with a charge-coupled device (CCD)-based reader was developed for rapid, sensitive, and quantitative detection of CA72-4. Two mouse monoclonal antibodies (mAbs) against CA72-4 were employed. One of them was coated as a test line, while another mAb was labeled with quantum dots and coated onto conjugate pad. The goat anti-mouse IgG was immobilized as a control line. After sample was added, a sandwich structure was formed with CA72-4 and these two mAbs. The fluorescent signal from quantum dots (QD)-labeled mAb in sandwich structure was related to the amount of detected CA72-4. A CCD-based reader was used to realize quantitative detection of CA72-4. Results showed that developed QD-labeled lateral flow strips to detect CA72-4 biomarker with the sensitivity of 2 IU/mL and 10 min detection time. One hundred sera samples from clinical patients with gastric cancer and healthy people were used to confirm specificity of this strip method; results showed that established strip method own 100 % reproducibility and 100 % specificity compared with Roche electrochemiluminescence assay results. In conclusion, CdSe/ZnS quantum dot-labeled lateral flow strips for detection of CA72-4 could realize rapid, sensitive, and specific detection of clinical samples and could own great potential in clinical translation in near future.