Eu Sites Research Articles

Safety of C1-Esterase Inhibitor in Acute and Prophylactic Therapy of Hereditary Angioedema: Findings from the Ongoing International Berinert Patient Registry

The plasma-derived, pasteurized C1-inhibitor (C1-INH) concentrate, Berinert has a 4-decade history of use in hereditary angioedema (HAE), with a substantial literature base that demonstrates safety and efficacy. Thromboembolic events have rarely been reported with C1-INH products, typically with off-label use or at supratherapeutic doses. Active surveillance of safety and clinical usage patterns of pasteurized C1-inhibitor concentrate and the more recent pasteurized, nanofiltered C1-INH, with a particular interest in thromboembolic events. A registry was initiated in April 2010 at 27 US and 4 EU sites to obtain both prospective and retrospective safety and usage data on subjects who were administered C1-INH (Berinert). As of May 10, 2013, data were available for 135 subjects and 3196 infusions. By subject, 67.4% were using C1-INH as on-demand therapy and 23.0% as both on-demand therapy and prophylactic administration. Approximately half of the infusions (49.5%) were administered for prophylaxis and >90% were given by the patient or a caregiver in the home setting. A total of 299 adverse events were reported, for an overall rate of 0.09 events per infusion with only 6 considered related to C1-INH. Two thromboembolic events were reported, both in patients with prothrombotic risk factors. This large pool of real-world clinical usage data in HAE further supports the extensive safety profile of 2 Berinert formulations when used on demand and/or for prophylaxis in both home and health care settings. No evidence was found to suggest that Berinert is an independent, causative risk factor for thromboembolic events.

Anomalous Eu valence state and superconductivity in undoped Eu3Bi2S4F4.

We have synthesized a novel europium bismuth sulfofluoride, Eu3Bi2S4F4, by solid-state reactions in sealed evacuated quartz ampules. The compound crystallizes in a tetragonal lattice (space group I4/mmm, a = 4.0771(1) Å, c = 32.4330(6) Å, and Z = 2), in which CaF2-type Eu3F4 layers and NaCl-like BiS2 bilayers stack alternately along the crystallographic c axis. There are two crystallographically distinct Eu sites, Eu(1) and Eu(2) at the Wyckoff positions 4e and 2a, respectively. Our bond valence sum calculation, based on the refined structural data, indicates that Eu(1) is essentially divalent, while Eu(2) has an average valence of ∼ +2.64(5). This anomalous Eu valence state is further confirmed and supported, respectively, by Mössbauer and magnetization measurements. The Eu(3+) components donate electrons into the conduction bands that are mainly composed of Bi 6px and 6py states. Consequently, the material itself shows metallic conduction and superconducts at 1.5 K without extrinsic chemical doping.

Luminescence properties of different Eu sites in LiMgPO4:Eu2+, Eu3+

The effect of temperature on the luminescence properties of LiMgPO4 doped with Eu3+ and Eu2+ are presented. Depending on the excitation wavelength, luminescence spectra consist of two distinct broad emission bands peaking at 380 nm and 490 nm related to 4f65d1 → 4f7 (8S7/2) luminescence of Eu2+ and to europium-trapped exciton, respectively, and/or several sharp lines between the 580 nm and 710 nm region, ascribed to the 5D0 → 7FJ (J = 0, 1, 2, 3 and 4) transitions in Eu3+. To explain all the features of the Eu2+ and Eu3+ luminescence we discussed the existence of two different Eu sites substituting for Li+, with short and long distance compensation. The evident effect of increasing the intensity of the Eu2+ luminescence with increasing temperature was observed. It was considered that the charge compensation mechanism for Eu3+ and Li+ as well as Eu2+ replacing Li+ in the LiMgPO4 is a long distance compensation that allows for the existence of some of the europium ions either as Eu3+ at low temperature or as Eu2+ at high temperature. We concluded that Eu2+ in the Li+ site with long distance compensation yields only 4f65d1 → 4f7 luminescence, whereas Eu2+ in the Li+ site with short distance compensation yields 4f65d1 → 4f7 luminescence and europium-trapped exciton emission.

Synthesis and photoluminescence properties of red-emitting phosphors Ba2Gd8(SiO4)6O2:Eu3+

Red-emitting phosphors Ba2Gd8(SiO4)6O2:Eu3+ (BGS:Eu3+) with silicate apatite structure were prepared by the conventional high temperature solid state reaction method. Rietveld structural refinement based on X-ray diffraction data indicated that there are two different sites for Eu3+ occupying in the host. It was found that the phosphors BGS:Eu3+ exhibit red emission with high quenching concentration at ~70.75at%, then the critical transfer distance of Eu3+ in BGS:Eu3+ was calculated to be ~12.3Å. More importantly, it has better CIE chromaticity coordinate for white light-emitting diode (w-LED) application in comparison with the commercial phosphor (Y,Gd)BO3:Eu3+ (YGB:Eu3+) under near ultraviolet (n-UV) 393nm excitation.

Color-Tunable Luminescence and Energy Transfer Properties of Ca9Mg(PO4)6F2:Eu2+, Mn2+ Phosphors for UV-LEDs

Eu2+-, Mn2+-activated Ca9Mg(PO4)6F2 (CMPF) phosphors with blue to yellow color-tunable emission properties have been synthesized via high-temperature solid-state reaction method. The crystal structure of Ca9Mg(PO4)6F2 has been identified by Rietveld refinement. The different crystallographic sites of Eu2+ in CMPF:Eu2+ phosphors have been confirmed by virtue of their fluorescence decay lifetimes. The Eu2+-activated CMPF phosphors exhibit broad excitation spectra from 200 to 420 nm (which matches well with the UV-based LED chips) and emission spectra from 380 to 580 nm centered at 454 nm. Energy transfer from Eu2+ to Mn2+ ions in Eu2+, Mn2+codoped CMPF samples is possible because of the spectral overlap between Eu2+ emission and Mn2+ excitation spectra, and the constant fall of fluorescence decay lifetimes of Eu2+ ion with increasing Mn2+ concentration demonstrates the occurrence of it, which provides the color-tunable emission from blue to yellow through adjusting Mn2+ concentration. The energy transfer mechanism between Eu2+ and Mn2+ ions is verified to be electric dipole–quadrupole interaction by analyzing the experimental results. The critical distance between them calculated by concentration quenching (14.57 Å) and spectral overlap methods (14.90 Å) are consistent, which testifies the energy transfer mechanism above from Eu2+ to Mn2+ is appropriate. These results show CMPF:Eu2+, Mn2+ phosphors could be anticipated for UV-pumped white-light-emitting diodes (wLEDs).

Coexistence of long range magnetic order and intervalent state of Eu in EuCu2(Si x Ge1 − x )2: Evidence from neutron diffraction and spectroscopic studies

Experimental results of the Xray absorption spectr oscopy, Mossbauer spectroscopy (isomer shift) and neu� tron diffraction are presented for the series of EuCu2(SixGe 1- x)2 polycrystalline samples (0 < x < 0.75). Homogeneous intermediate valence state is established for Eu ions as well as long range magnetically ordered state at the temperatures below 10-15 K. Observation of the ordered magnetic moments at Eu site gives rise to the experimental statement for the coexistence of valence fluctuations and long range magnetic order takes place in the wide range of Ge concentrations for this substance.

Influence of metal loading and humic acid functional groups on the complexation behavior of trivalent lanthanides analyzed by CE-ICP-MS

The complexation behavior of Aldrich humic acid (AHA) and a modified humic acid (AHA-PB) with blocked phenolic hydroxyl groups for trivalent lanthanides (Ln) is compared, and their influence on the mobility of Ln(III) in an aquifer is analyzed. As speciation technique, capillary electrophoresis (CE) was hyphenated with inductively coupled plasma mass spectrometry (ICP-MS). For metal loading experiments 25mgL−1 of AHA and different concentrations (cLn(Eu+Gd)=100–6000μgL−1) of Eu(III) and Gd(III) in 10mM NaClO4 at pH 5 were applied. By CE-ICP-MS, three Ln-fractions, assumed to be uncomplexed, weakly and strongly AHA-complexed metal can be detected. For the used Ln/AHA-ratios conservative complex stability constants log βLnAHA decrease from 6.33 (100μgL−1 Ln3+) to 4.31 (6000μgL−1 Ln3+) with growing Ln-content. In order to verify the postulated weaker and stronger humic acid binding sites for trivalent Eu and Gd, a modified AHA with blocked functional groups was used. For these experiments 500μgL−1 Eu and 25mgL−1 AHA and AHA-PB in 10mM NaClO4 at pH-values ranging from 3 to 10 have been applied. With AHA-PB, where 84% of the phenolic OH-groups and 40% of the COOH-groups were blocked, Eu complexation was significantly lower, especially at the strong binding sites. The log β-values decrease from 6.11 (pH 10) to 5.61 at pH 3 (AHA) and for AHA-PB from 6.01 (pH 7) to 3.94 at pH 3. As a potential consequence, particularly humic acids with a high amount of strong binding sites (e.g. phenolic OH- and COOH-groups) can be responsible for a higher metal mobility in the aquifer due to the formation of dissolved negatively charged metal-humate species.

Abstract P2-16-01: A randomized, phase II, multicenter, double-blind, placebo-controlled trial evaluating onartuzumab with or without bevacizumab in combination with weekly paclitaxel in locally recurrent or metastatic triple-negative breast cancer (TNBC)

Abstract Background: Dysregulation of the hepatocyte growth factor (HGF)/MET pathway has been observed in many malignancies. In patients with TNBC, overexpression of MET has been shown to be associated with poor prognosis. Onartuzumab (MetMAb) is a recombinant, humanized, monovalent, monoclonal antibody directed against MET, which selectively blocks ligand binding and subsequent HGF activation. A recent phase 2 trial demonstrated improved progression-free survival (PFS) and overall survival (OS) when onartuzumab was added to erlotinib for patients with MET 2+/3+ non-small-cell lung cancer (NSCLC). Methods: Patients with locally recurrent or metastatic TNBC who had received 0 or 1 prior therapies for metastatic disease were enrolled, provided tumor sample, and randomized (1:1:1) to receive paclitaxel (P) + bevacizumab (B) + onartuzumab (O); P+O; or P+B. Dosing regimens were given IV q4w: P 90 mg/m2 d1, 8 &amp; 15; B 10 mg/kg d1 &amp; 15; O 10 mg/kg d1 &amp; 15. Treatment continued until disease progression or unacceptable toxicity or death; crossover was not permitted. Stratification was by number of metastatic sites (&amp;lt;3, ≥3), number of prior MBC regimens (1 vs 2), and disease-free interval for first-line patients (≤6 months, &amp;gt;6 months). The primary endpoint was PFS; secondary endpoints included OS, objective response rate (ORR), and safety. MET immunohistochemistry (IHC) was performed centrally for exploratory analyses. Results: 185 patients were enrolled from 30 US and 37 EU sites: median age was 53 years (range 30-79); 77% and 23% were treated in the first- and second-line settings, respectively. Baseline characteristics were balanced. Efficacy data for the ITT population are shown in Table 1. The distribution of MET expression using the NSCLC diagnostic algorithm is shown in Table 2. The MET 2+/3+ group was too small for efficacy analyses. Frequently observed AEs (all grades) included peripheral edema (58% vs 59% vs 18%), fatigue (47% vs 41% vs 48%) and diarrhea (53% vs 22% vs 50%), in the P+B+O vs P+O vs P+B arms, respectively. No new safety signals were observed. Table 1Table 1ITT populationP+B+O n = 63P+O n = 60P+B (control) n = 62Median PFS, months7.35.47.2HR vs control (95% CI)1.08 (0.69 - 1.70)1.74 (1.13 - 2.78)-Median OS, months14.713.417.4HR vs control (95% CI)1.35 (0.74 - 2.44)1.88 (1.00 - 3.54)-ORR,% (95% CI)42 (29 - 57)28 (16 - 41)55 (41 - 68) Conclusions: In the ITT population, the addition of O to either P+B or to P alone did not improve PFS and other clinical outcomes compared with P+B alone. Further exploratory subgroup analyses are ongoing. Table 2Table 2MET IHC score01+2+3+Not availablen (%)81 (44)75 (41)21 (11)1 (0.5)7 (4) Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-01.

Vibrationally induced center reconfiguration in co-doped GaN:Eu, Mg epitaxial layers: Local hydrogen migration vs. activation of non-radiative channels

Europium doped gallium nitride (GaN:Eu) is a promising candidate as a material for red light emitting diodes. When Mg was co-doped into GaN:Eu, additional incorporation environments were discovered that show high excitation efficiency at room temperature and have been attributed to the coupling of Mg-H complexes to the majority Eu site. Electron beam irradiation, indirect and resonant (direct) laser excitation were found to modify these complexes, indicating that vibrational energy alone can trigger the migration of the H while the presence of additional charges and excess energy controls the type of reconfiguration and the activation of non-radiative decay channels.

Defect roles in the excitation of Eu ions in Eu:GaN

Eu ions in situ doped in GaN with V/III ratios varying from 3200 to 9600 have been investigated using resonant site-selective photoluminescence (PL), power dependent cathodoluminescence (CL), and a unique electron beam power dependent dual excitation experiment combining the techniques of PL and CL. The results of these experiments reveal the role of defects in the electronic excitation of Eu ions and the link between the GaN host and Eu ion dopants. The relative number of beneficial defects present in each sample for a majority Eu site (Eu1) and a specific secondary site (Eu2) are revealed. Also, a room temperature activated non-radiative recombination pathway linked to a specific, sample dependent Eu2 excitation pathway is identified. Unlike conventional GaN LEDs, Eu:GaN device performance does not rely completely on crystalline quality, but on the presence of specific excitation enhancing defects and the absence of non-radiative de-excitation channels.

Evolution of Luminescence of Sr2–y–zCazSi(O1–xNx)4:yEu2+ with N3–, Eu2+, and Ca2+ Substitutions

Sr2–y–zCazSi(O1–xNx)4:yEu2+ (SCSON:Eu2+) solid solutions were prepared by substituting N3-, Eu2+, and Ca2+ ions into Sr2SiO4 (SSO). These ions contributed differently to the evolution of luminescence of SCSON:Eu2+. SSON:Eu2+ (z = 0) has two activation centers: Eu(I) and Eu(II). The nitridation effects led to a dramatic change in the crystal field surrounding the Eu(II) site but rarely affected the Eu(I) site. Accordingly, SSON:Eu2+ exhibited broad excitation spectra from ultraviolet to visible wavelengths. In comparison with the Eu(II) green emissions of SSO:Eu2+, the dominant peak wavelengths (DPWs) of the Eu(II) emissions were at red emission regions (605–630 nm), depending on the amount of Eu2+ ions. The Ca2+ ions of SCSON:Eu2+ preferentially changed the emission wavelength assigned to Eu(I) and affected the Eu(II) emission intensity. In addition to the spectral properties, the chromaticity coordinates and a low thermal quenching behavior of SCSON:Eu2+ powders demonstrated that they can be a novel red phosphors for use in white light emitting diodes.

The effect of different lattice sites substitution on photoluminescence characteristics of Eu2+/Ce3+ doped M5(ZO4)3X

The empirical formula of Van Uitert is applied to calculating the emission wavelengths of haloapatite and silicon apatite phosphors doped with Eu2+/Ce3+. The relationship between emission wavelengths and occupied lattice sites of Eu2+/Ce3+ is discussed in haloapatite crystal. For phosphors of haloapatite and silicon apatite doped with Eu2+, the emission bands of the long-wave region are interpreted reasonably. Phosphors Sr5(PO4)2SiO4 doped with Eu2+/Ce3+ are synthesized by high temperature solid state reaction under two different atmospheres, the spectral characteristics of Eu2+/Ce3+ occupying different lattice sites are studied. The luminescent materials Sr5(PO4)2SiO4 doped with Eu2+/Ce3+ are promising blue-green phosphors for application in white-LEDs.

A New Multinational Observational Study In Multiple Myeloma: Initial Report Of The PREAMBLE Study

IntroductionThe advent of novel immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) have improved clinical outcomes of multiple myeloma (MM) in the past decade. Clinical trial data have shown combination novel therapies (IMiD+PI) can provide even further improvement. The PREAMBLE (Prospective Research Assessment in Multiple Myeloma: an Observational Evaluation) is a global study designed to evaluate clinical effectiveness, healthcare resource utilization, and patient-reported outcomes associated with novel therapies for treatment of relapsed or refractory MM (R/R MM) in the real-world daily practices in the US and Europe. We describe the study design and baseline characteristics of the first 111 patients enrolled. MethodsThis is a prospective, observational, longitudinal cohort study of adult patients with R/R MM who received at least 1 prior therapy and initiated treatment with IMiDs, PIs, or IMiDs+PIs within 90 days prior to or 30 days after enrollment. Follow-up is up to 3 yrs after consent. Patients receive standard of care treatment as determined by the treating physician. Planned enrollment is 1000 patients in North America (NA) and Europe (EU; France, Germany, Italy, and UK). ResultsAs of June 28, 2013, 111 patients from 63 sites in NA (n=64) and EU (n=47) have been enrolled. Baseline characteristics are summarized in Table 1. Cytogenetics (by FISH) was determined in 51% (n=57) of patients; of these, 16% (n=9) were high risk with del 17p (78%) as the predominant abnormality. Baseline treatment varied by region: of the patients in NA, IMiDs were used in 44% (n=28), PIs in 36% (n=23), and IMiD+PI in 20% (n=13) versus 60% (n=28), 34% (n=16), and 6% (n=3), respectively, in EU. Of the 16% high risk patients and the 25% of patients initially diagnosed at ISS stage III, none received IMiD+PI. The percentage of patients who received only 1 prior regimen at enrollment was 46% (n=26) in the IMiD group, 41% (n=16) in the PI group, and 63% (n=10) in the IMiD+PI group while the percentage of patients who received 3 or more prior regimens was 16% (n=9) in the IMiD group, 36% (n=14) in the PI group, and 6% (n=1) in the IMiD+PI group. Median time from diagnosis to enrollment for patients receiving IMiDs was 43 months, PIs was 42 months, and IMiDs+PIs was 33 months. ConclusionPREAMBLE provides a rich data source for evaluation of clinical, economic, and humanistic outcomes in patients treated for R/R MM. Initial data suggest different treatment patterns between patients in the US and in EU. Continued follow-up and larger sample size may help identify factors associated with different treatment choices and impact on clinical effectiveness, tolerability, resource utilization, and humanistic outcomes in patients treated for R/R MM. Disclosures:Vij:Celgene: Research Funding, Speakers Bureau; Onyx: Research Funding, Speakers Bureau; Millennium: Speakers Bureau; BMS: Honoraria; Lilly: Honoraria. Palumbo:Amgen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Janssen Pharmaceuticals: Consultancy, Honoraria; Millenium: Consultancy, Honoraria; Onyx: Consultancy, Honoraria. Kaya:Millennium: Honoraria, Speakers Bureau. Durie:Millennium: Consultancy; Onyx: Consultancy; Celgene: Consultancy. Cella:BMS: Consultancy. Annemans:BMS: Consultancy. Su:BMS: Employment, Equity Ownership. Mukhopadhyay:BMS: Employment, Equity Ownership. Le:BMS: Employment. Petrucci:Celgene: Consultancy, Honoraria; Janssen-Cilag: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria.

2D‐ and 3D‐Photoluminescence Imaging of Eu(III) Embedded in CeO2 Nanomatrix

2D‐ and 3D‐photoluminescence characteristics of Eu(III) doped in CeO2 nanoparticles were fully imaged for the first time. Their fundamental natures were also examined by scanning electron microscopy (SEM), X‐ray diffraction (XRD) crystallography, and UV–visible absorption spectroscopy. The magnetic dipole 5D0 → 7F1 transition was dominated by an indirect transition associated with a O2−–Ce4+ charge‐transfer band of CeO2. The electric dipole 5D0 → 7F2 transition was dominated by a direct transition of Eu(III), indicating that Eu(III) replaces Ce(IV) at octahedral sites (Oh and O) with and without an inversion center. Upon annealing, the photoluminescence intensity caused by direct transition was dramatically decreased, whereas that induced by indirect transition was greatly enhanced. These findings indicate that charge transfer to the Eu(III) at the octahedral (Oh) site with the inversion center is more efficient than that to the Eu(III) site without an inversion center. The absolute quantum yield for the 10 mol% Eu(III)–CeO2 was found to be ϕ = 0.007 at an excitation wavelength of 350 nm. The photoluminescence of Tb‐doped CeO2 was briefly discussed for comparison.

Structural Phase Transitions in a New Compound Eu2AgGe3

A new intermetallic compound Eu2AgGe3 has been synthesized using high-frequency induction heating method. Single-crystal X-ray diffraction data showed that Eu2AgGe3 crystallizes in the orthorhombic Ba2LiSi3 structure type, with Fddd space group and lattice parameters a = 8.7069(17) Å, b = 15.011(3) Å, c = 17.761(4) Å. Eu2AgGe3 is composed of infinite arrays of hexagonal [Ag3Ge3] units stacked along the [001] direction, and the Eu sites are sandwiched between these parallel hexagonal networks. Temperature-dependent powder XRD data and DTA hint toward a structural phase transition from orthorhombic to hexagonal above 477 K and an unusual reversible transition to the original phase, i.e., orthorhombic phase at around 718 K. Magnetic measurements on Eu2AgGe3 sample show paramagnetic behavior above 100 K and weak ferromagnetic interactions below 80 K. Mössbauer spectroscopy and X-ray absorption near-edge spectroscopic (XANES) studies reveal that Eu atoms in Eu2AgGe3 exist in the divalent oxidation state.

Changes in particulate matter physical properties during Saharan advections over Rome (Italy): a four-year study, 2001–2004

Abstract. Particulate matter mass concentrations measured in the city of Rome (Italy) in the period 2001–2004 have been cross-analysed with concurrent Saharan dust advection events to infer the impact these natural episodes bear on the standard air quality parameter PM10 observed at two city stations and at one regional background station. Natural events such as Saharan dust advections are associated with a definite health risk. At the same time, the Directive 2008/50/EC allows subtraction of PM exceedances caused by natural contributions from statistics used to determine air quality of EU sites. In this respect, it is important to detect and characterise such advections by means of reliable, operational techniques. To assess the PM10 increase we used both the "regional-background method" suggested by EC Guidelines and a "local background" method, demonstrated to be most suited to this central Mediterranean region. In terms of exceedances, the two approaches provided results within ~20% of each other at background sites, and at ~50% of each other in traffic conditions. The sequence of Saharan advections over the city has been either detected by Polarization Lidar (laser radar) observations or forecast by the operational numerical regional mineral dust model BSC-DREAM8b of the Barcelona Supercomputing Centre. Lidar observations were also employed to retrieve the average physical properties of the dust clouds as a function of height. Over the four-year period, Lidar measurements (703 evenly distributed days) revealed Saharan plumes transits over Rome on 28.6% of the days, with minimum occurrence in wintertime. Dust was observed to reach the ground on 17.5% of the days totalling 88 episodes. Most (90%) of these advections lasted up to 5 days, averaging to ~3 days. Median time lag between advections was 7 days. Typical altitude range of the dust plumes was 0–6 km, with the centre of mass at ~3 km a.g.l. BSC-DREAM8b model simulations (1461 days) predicted Lidar detectable (532 nm extinction coefficient &gt; 0.005 km−1) dust advections on 25.9% of the days, with ground contacts on 13% of the days. As in the Lidar case, the average dust centre of mass was forecast at ~3 km. Along the 703 day Lidar dataset, model forecast and Lidar detection of the presence of dust coincided on 80% of the cases, 92% coincidences are found within a ±1 day window. Combination of the BSC-DREAM8b and Lidar records leads to about 21% of the days being affected by presence of Saharan dust at the ground. This combined dataset has been used to compute the increase in PM with respect to dust-unaffected previous days. This analysis has shown Saharan dust events to exert a meaningful impact on the PM10 records, causing average increases of the order of 11.9 μg m−3. Conversely, PM10 increases computed relying only on the Lidar detections (i.e., presence of dust layers actually observed) were of the order of 15.6 μg m−3. Both analyses indicate the annual average contribution of dust advections to the city PM10 mass concentrations to be of the order of 2.35 μg m−3. The number of exceedances attributable to Saharan advections at the three station types addressed in this study (urban traffic, urban background and regional background) were found to be 25%, 30% and 43%, respectively. These results confirm Saharan advections in the central Mediterranean as important modulators of PM10 loads and exceedances.

Comparison of pesticide leaching potential to groundwater under EU FOCUS and site specific conditions

The EU FOCUS scenarios are a set of nine standard scenarios based on a combination of crop, soil and weather data used throughout Europe to evaluate the leaching potential of pesticides to groundwater. In Ireland, two predefined EU FOCUS scenarios (Okehampton and Hamburg) appear to be the most appropriate to Irish conditions. However, there is concern that these scenarios may not accurately represent Irish specific conditions, especially in terms of soil and climatic weather. Therefore, the objective of this study was to parameterise a number of site specific locations in Ireland (represented by Oakpark, Clonroche, Rathangan and Elton series soils) and to compare simulated leachate levels at these locations to EU FOCUS scenarios using the PELMO (Pesticide Leaching Model) simulation model. The hydrological processes were validated using observed data for soil tension and leachate. The appropriate EU FOCUS scenarios were then simulated for the given locations and compared to the parameterised scenario. All scenarios were run using the same version of PELMO, therefore eliminating any software impacts. The models were run for 26years using appropriate meteorological data. The results showed significant difference between the parameterised model pesticide leaching and that resulting from the EU FOCUS scenarios, the latter overestimating site pesticide leaching from 42 to 99%. The results indicated a significant conservatism in using EU FOCUS scenarios to determine potential pesticide concentration in the leachate under Irish specific conditions and ensure the desired level of protection against pesticide contamination of national water resources.

What Factors Affect the5D0Energy of Eu3+? An Investigation of Nephelauxetic Effects

Relationships involving the interelectronic repulsion parameters, F(k) (k = 2, 4, 6), the spin-orbit coupling constant, ζf, and J-mixing, with the (5)D0-(7)F0 energy, E, have been investigated for Eu(3+) using various approaches. First, the linear relationship between E and the (7)F1 splitting (or the second rank crystal field parameter) is shown to be applicable not only to glasses but also to solid-state crystalline systems with Eu(3+) site symmetry of C2, C2v, or lower. In these cases, the change in (5)D0-(7)F0 energy is mainly due to the J-mixing effect of (7)F(J) (J = 2, 4, 6: most notably J = 2) which depresses (7)F0, whereas the (5)D0 energy is relatively constant. The (5)D0-(7)F0 energy also depends upon certain energy parameters in the Hamiltonian, in particular, F(k) and ζf. Model calculations show that increase in F(4) or F(6) produces an increase in E, whereas increase in F(2) produces a decrease in E. An increase in ζf produces a decrease in E. These findings are rationalized. Most previous 4f(6) crystal field calculations have only considered the F and D terms of Eu(3+) so that the Slater parameters are not well-determined. More reliable energy level data sets and crystal field calculations for Eu(3+) with fluoride, oxide, or chloride ligands have been selected, and certain of these have been repeated since most previous calculations have errors in matrix elements. The fitted Slater parameters have been corrected for the effects of three-body Coulomb interactions. Some systems do not follow the ligand trend F ~ O > Cl for Slater and spin-orbit parameters. From the limited data available, the average values of the corrected Slater parameters are greater for fluoride compared with chloride ligands, but the differences are comparable with the standard deviations of the parameters. There is no clear nephelauxetic series for these three types of ligands, with respect to spin-orbit coupling. Previous correlations of E with various parameters are of limited value because the (5)D0-(7)F0 energy difference not only depends upon the F(k) and ζf parameters but in addition is sensitive to the importance of J-mixing for low symmetry systems.

On the nature of carrier relaxation and ion–ion interactions in ultrasmall β-NaYF4:Eu3+nanocrystals – effect of the surface

The purely hexagonal phase of ultrasmall (~10 nm) NaYF(4) nanocrystals (NCs), containing different Eu concentrations, has been obtained by a modified co-thermolysis method. Detailed investigations of the excitation and relaxation mechanisms of the Eu ions in such NCs are reported. Based on the photoluminescence excitation, absorbance, photoluminescence and emission decay times measured as a function of the excitation wavelengths, it has been shown that two Eu sites with different excitation and relaxation characteristics are present in the case of ultrasmall NaYF(4) NCs. It has been shown that, when the Eu concentration increases, strong ion-ion interactions influence the relaxation phenomena in Eu ions, changing their optical properties. Moreover, these ion-ion interactions enable connections between the surface ions and the internal ones via energy transfer from the surface to the NCs core. Furthermore, it has been proposed that the different kinetic properties of the surface Eu ions are mainly caused by the formation of a charge transfer state between the ions and ligand groups attached to the NCs surface.

Identification of the crystallographic sites of Eu2+ in Ca9NaMg(PO4)7: structure and luminescence properties study

The substituted activator ions Eu(2+) in the β-Ca3(PO4)2-type structure, Ca9NaMg(PO4)7 compound, have been studied as emission centers, as well as structural probes. The crystal structure and crystallographic sites of Eu(2+) in Ca9NaMg(PO4)7 have been identified by Rietveld refinements, electron paramagnetic resonance (EPR) spectroscopy analysis and combined photoluminescence spectral analysis, respectively. Ca9NaMg(PO4)7:Eu(2+) phosphor exhibits a broad emission band in the visible light region with three distinguished peaks centered at 415, 458, and 615 nm, which are ascribed to different Eu(2+) emission centers occupied in three different Ca crystallographic sites. The concentration quenching behavior, variation in lifetimes and the temperature dependent luminescence properties have been investigated as a function of different emission centers, 415, 458, and 625 nm for Ca9NaMg(PO4)7:Eu(2+) phosphor. Accordingly, the relationship among three different Eu(2+) luminescence centers originating from three different Ca(2+) crystallographic sites has been found and verified.