Alternative method to determine Specific Activity of (177)Lu by HPLC.

PubMed

Breeman, Wouter A P; de Zanger, Rory M S; Chan, Ho Sze; de Blois, Erik

2015-01-01

Peptide Receptor Radionuclide Therapy (PRRT) with (177)Lu-DOTA-peptides requires (177)Lu with high specific activity (SA) and values >740 GBq (177)Lu per mg Lu to maximise the atom% of (177)Lu over total Lu. Vendors provide SA values which are based on activity and mass of the target, whereas due to "burn-up" of target, these SA values are not accurate. For a radiochemist the SA of (177)Lu is of interest prior to radiolabeling. An alternative method to determine SA was developed by HPLC, which includes a metal titration of a known amount of DOTA-peptide with a known amount of activity ((177)Lu), and a unknown amount of metal ((177+nat)Lu). Based on an HPLC separation of radiometal-DOTA-peptide and DOTA-peptide, and the concordant ratio of these components the metal content ((177+nat)Lu) can be calculated, and eventually the SA of (177)Lu can be accurately determined. These experimentally determined SA values exceeded the estimated values provided by vendors by 27 ± 16%, (range 6-73 %). The deviation of SA values for samples from the same Lu batch was <2% (n ≥ 10). the SA of (177)Lu is apparently often higher as stated by vendors in comparison to the experimentally determined actual values. For this reason, the SA of (177)Lu-DOTA-TATE and other Lu-DOTA-peptides could be increased accordingly.

The Bad Berka dose protocol: comparative results of dosimetry in peptide receptor radionuclide therapy using (177)Lu-DOTATATE, (177)Lu-DOTANOC, and (177)Lu-DOTATOC.

PubMed

Schuchardt, Christiane; Kulkarni, Harshad R; Prasad, Vikas; Zachert, Carolin; Müller, Dirk; Baum, Richard P

2013-01-01

The objective of this study is to analyze the in vivo behavior of the (177)Lu-labeled peptides DOTATATE, DOTANOC, and DOTATOC used for peptide receptor radionuclide therapy (PRRNT) of neuroendocrine tumors (NETs), by measuring organ and tumor kinetics and by performing dosimetric calculations. Two hundred fifty-three patients (group 1) with metastasized NET who underwent PRRNT were examined. Out of these, 185 patients received (177)Lu-DOTATATE, 9 were treated with (177)Lu-DOTANOC, and 59 with (177)Lu-DOTATOC. Additionally, 25 patients receiving, in consecutive PRRNT cycles, DOTATATE followed by DOTATOC (group 2) and 3 patients receiving DOTATATE and DOTANOC (group 3) were analyzed. Dosimetric calculations (according to MIRD scheme) were performed using OLINDA software. In group 1, DOTATOC exhibited the lowest and DOTANOC the highest uptake and therefore mean absorbed dose in normal organs (whole body, kidney, and spleen). In group 2, there was a significant difference between DOTATATE and DOTATOC concerning kinetics and normal organ doses. (177)Lu-DOTATOC had the lowest uptake/dose delivered to normal organs and highest tumor-to-kidney ratio. There were no significant differences between the three peptides concerning tumor kinetics and mean absorbed tumor dose. The study demonstrates a correlation between high affinity of DOTANOC in vitro and high uptake in normal organs/whole body in vivo, resulting in a higher whole-body dose. DOTATOC exhibited the lowest uptake and dose delivered to normal tissues and the best tumor-to-kidney ratio. Due to large interpatient variability, individual dosimetry should be performed for each therapy cycle.

Quasi four-level Tm:LuAG laser

NASA Technical Reports Server (NTRS)

Jani, Mahendra G. (Inventor); Barnes, Norman P. (Inventor); Hutcheson, Ralph L. (Inventor); Rodriguez, Waldo J. (Inventor)

1997-01-01

A quasi four-level solid-state laser is provided. A laser crystal is disposed in a laser cavity. The laser crystal has a LuAG-based host material doped to a final concentration between about 2% and about 7% thulium (Tm) ions. For the more heavily doped final concentrations, the LuAG-based host material is a LuAG seed crystal doped with a small concentration of Tm ions. Laser diode arrays are disposed transversely to the laser crystal for energizing the Tm ions.

Prediction of Normal Organ Absorbed Doses for [177Lu]Lu-PSMA-617 Using [44Sc]Sc-PSMA-617 Pharmacokinetics in Patients With Metastatic Castration Resistant Prostate Carcinoma.

PubMed

Khawar, Ambreen; Eppard, Elisabeth; Sinnes, Jean Phlippe; Roesch, Frank; Ahmadzadehfar, Hojjat; Kürpig, Stefan; Meisenheimer, Michael; Gaertner, Florian C; Essler, Markus; Bundschuh, Ralph A

2018-04-23

In vivo pharmacokinetic analysis of [Sc]Sc-PSMA-617 was used to determine the normal organ-absorbed doses that may result from therapeutic activity of [Lu]Lu-PSMA-617 and to predict the maximum permissible activity of [Lu]Lu-PSMA-617 for patients with metastatic castration-resistant prostate carcinoma. Pharmacokinetics of [Sc]Sc-PSMA-617 was evaluated in 5 patients with metastatic castration-resistant prostate carcinoma using dynamic PET/CT, followed by 3 static PET/CT acquisitions and blood sample collection over 19.5 hours, as well as urine sample collection at 2 time points. Total activity measured in source organs by PET imaging, as well as counts per milliliter measured in blood and urine samples, was decay corrected back to the time of injection using the half-life of Sc. Afterward, forward decay correction using the half-life of Lu was performed, extrapolating the pharmacokinetics of [Sc]Sc-PSMA-617 to that of [Lu]Lu-PSMA-617. Source organs residence times and organ-absorbed doses for [Lu]Lu-PSMA-617 were calculated using OLINDA/EXM software. Bone marrow self-dose was determined with indirect blood-based method, and urinary bladder contents residence time was estimated by trapezoidal approximation. The maximum permissible activity of [Lu]Lu-PSMA-617 was calculated for each patient considering external beam radiotherapy toxicity limits for radiation absorbed doses to kidneys, bone marrow, salivary glands, and whole body. The predicted mean organ-absorbed doses were highest in the kidneys (0.44 mSv/MBq), followed by the salivary glands (0.23 mSv/MBq). The maximum permissible activity was highly variable among patients; limited by whole body-absorbed dose (1 patient), marrow-absorbed dose (1 patient), and kidney-absorbed dose (3 patients). [Sc]Sc-PSMA-617 PET/CT imaging is feasible and allows theoretical extrapolation of the pharmacokinetics of [Sc]Sc-PSMA-617 to that of [Lu]Lu-PSMA-617, with the intent of predicting normal organ-absorbed doses and maximum

Growth and characterization of LuAs films and nanostructures

NASA Astrophysics Data System (ADS)

Krivoy, E. M.; Nair, H. P.; Crook, A. M.; Rahimi, S.; Maddox, S. J.; Salas, R.; Ferrer, D. A.; Dasika, V. D.; Akinwande, D.; Bank, S. R.

2012-10-01

We report the growth and characterization of nearly lattice-matched LuAs/GaAs heterostructures. Electrical conductivity, optical transmission, and reflectivity measurements of epitaxial LuAs films indicate that LuAs is semimetallic, with a room-temperature resistivity of 90 μΩ cm. Cross-sectional transmission electron microscopy confirms that LuAs nucleates as self-assembled nanoparticles, which can be overgrown with high-quality GaAs. The growth and material properties are very similar to those of the more established ErAs/GaAs system; however, we observe important differences in the magnitude and wavelength of the peak optical transparency, making LuAs superior for certain device applications, particularly for thick epitaxially embedded Ohmic contacts that are transparent in the near-IR telecommunications window around 1.3 μm.

Lu-Hf constraints on the evolution of lunar basalts

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

Fujimaki, H.; Tatsumoto, M.

1984-02-15

Very low Ti basalts andd green glass samples from the moon show high Lu/Hf ratios and low Hf concentrations. Low-Ti lunar basalts show high and variable Lu/Hf ratios and higher Hf concentrations, whereas high-Ti lunar basalts show low Lu/Hf ratios and high Hf concentrations. KREEP basalts have constant Lu/Hf ratios and high but variable Hf concentrations. Using the Lu-Hf behavior as a constraint, we propose a model for the mare basalts evolution. This constraint requires extensive crystallization of the primary lunar magma ocean prior to formation of the lunar mare basalt sources and the KREEP basalts. Mare basalts are producedmore » by the melting of the cumulate rocks, and KREEP basalts represent the residual liquid of the magma ocean.« less

Growth and characterization of LuAs films and nanostructures

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

Krivoy, E. M.; Nair, H. P.; Crook, A. M.

2012-10-01

We report the growth and characterization of nearly lattice-matched LuAs/GaAs heterostructures. Electrical conductivity, optical transmission, and reflectivity measurements of epitaxial LuAs films indicate that LuAs is semimetallic, with a room-temperature resistivity of 90 {mu}{Omega} cm. Cross-sectional transmission electron microscopy confirms that LuAs nucleates as self-assembled nanoparticles, which can be overgrown with high-quality GaAs. The growth and material properties are very similar to those of the more established ErAs/GaAs system; however, we observe important differences in the magnitude and wavelength of the peak optical transparency, making LuAs superior for certain device applications, particularly for thick epitaxially embedded Ohmic contacts that aremore » transparent in the near-IR telecommunications window around 1.3 {mu}m.« less

The role of phosphates for the Lu-Hf chronology of meteorites

NASA Astrophysics Data System (ADS)

Debaille, Vinciane; Van Orman, James; Yin, Qing-Zhu; Amelin, Yuri

2017-09-01

The 176Lu-176Hf isotopic system is widely used for dating and tracing cosmochemical and geological processes, but still suffers from two uncertainties. First, Lu-Hf isochrons for some early Solar System materials have excess slope of unknown origin that should not be expected for meteorites with ages precisely determined with other isotopic chronometers. This observation translates to an apparent Lu decay constant higher than the one calculated by comparing ages obtained with various dating methods on terrestrial samples. Second, unlike the well constrained Sm/Nd value (to within 2%) for the chondritic uniform reservoir (CHUR), the Lu/Hf ratios in chondrites vary up to 18% when considering all chondrites, adding uncertainty to the Lu/Hf CHUR value. In order to better understand the Lu-Hf systematics of chondrites, we analyzed mineral fractions from the Richardton H5 chondrite to construct an internal Lu-Hf isochron, and set up a numerical model to investigate the effect of preferential diffusion of Lu compared to Hf from phosphate, the phase with the highest Lu-Hf ratio in chondrites, to other minerals. The isochron yields an age of 4647 ± 210 million years (Myr) using the accepted 176Lu decay constant of 1.867 ± 0.008 ×10-11yr-1. Combining this study with the phosphate fractions measured in a previous study yields a slope of 0.08855 ± 0.00072, translating to a 176Lu decay constant of 1.862 ± 0.016 ×10-11yr-1 using the Pb-Pb age previously obtained, in agreement with the accepted value. The large variation of the Lu/Hf phosphates combined with observations in the present study identify phosphates as the key in perturbing Lu-Hf dating and generating the isochron slope discrepancy. This is critical as apatite has substantially higher diffusion rates of rare earth elements than most silicate minerals that comprise stony meteorites. Results of numerical modeling depending of temperature peak, size of the grains and duration of the metamorphic event, show that

Additional lesions detected in therapeutic scans with 177Lu-DOTATATE reflect higher affinity of 177Lu-DOTATATE for somatostatin receptors.

PubMed

Mirzaei, Siroos; Bastati, Brigitte; Lipp, Rainer W; Knoll, Peter; Zojer, Niklas; Ludwig, Heinz

2011-01-01

Peptide receptor-targeted radionuclide therapy (PRRT) of somatostatin receptor (SR)-expressing neuroendocrine tumors (NETs) has become an established therapeutic option in patients with advanced NETs. The aim of this study was to compare the lesion detection rate of (99m)Tc-EDDA/HYNIC-TOC, a newly developed tracer for NET imaging, with (177)Lu-DOTATATE used for PRRT. 8 patients (4 women, 4 men, age range 46-76 years) with histologically proven NETs, who showed high SR loads by (99m)Tc-EDDA/HYNIC-TOC scintigraphy, were treated with (177)Lu-DOTATATE. After treatment, all patients were subjected to whole-body scintigraphy with additional low-dose single-photon emission computed tomography (SPECT-CT) of the chest and abdomen. All patients demonstrated (177)Lu-DOTATATE accumulation in all lesions previously detected by (99m)Tc- EDDA/HYNIC-TOC scintigraphy. Three patients showed additional lesions in the liver and lungs. SPECT-CT after (177)Lu-DOTATATE therapy may be helpful in detecting additional lesions not seen using (99m)Tc-EDDA/HYNIC-TOC. This could reflect the broader affinity of (177)Lu-DOTATATE for SRs compared with (99m)Tc-EDDA/HYNIC-TOC. Copyright © 2011 S. Karger AG, Basel.

The NCU Lu-Lin Observatory Survived the Taiwan 921 Earthquake

NASA Astrophysics Data System (ADS)

Tsay, W. S.; Chang, K. H.; Li, H. H.

1999-12-01

The NCU (National Central University) Lu-Lin Observatory is located at Mt. Front Lu-Lin, 120o 52' 25" E and 23o 28' 07" N, a 2862-m peak in the Yu-Shan National Park. The construction of Lu-Lin Observatory was finished in January 1999. Fortunately the Lu-Lin Observatory survived the Taiwan 921 Earthquake that was 7.3 on the Ritcher scale. We are proud of the design of Lu-Lin Observatory adopted H-beam and steel wall even the center of earthquake was only 40 km away. The initial study of Lu-Lin site was started since late 1989. Later on, a three-year project was founded by the National Science Council , which supported the development of a modern seeing monitor for this site survey study from 1990 through 1993. The average seeing of Lu-Lin site is about 1.39 arc-second with average 200 clear nights annually. The sky background of this site is 20.72 mag/arcsec2 in V band and 21.22 mag/arcsec2 in B band. The Lu-Lin observatory is developed for both research and education activity. A homemade 76-cm Super Light Telescope (SLT) and three TAOS's 50-cm robotic telescopes will be the two major research facilities. This work is supported by the National Science Council of Taiwan.

Chen Ning Yang’s New Contributions After He Returned to Where He Started

NASA Astrophysics Data System (ADS)

Zhu, Bang-Fen

2018-01-01

Chen Ning Yang returned to Tsinghua University as a full professor in 2003. Regarding the fact that very few people know what Professor Yang has contributed to science and to China after his return, in this article new contributions of Chen Ning Yang are introduced as far as the author knows, including his leading role in China’s sciences, the research in statistical physics, the role in cultivating gifted students, his research in history of science, and all other aspects relating to China’s developments.

Mixed Messages from Garnet Lu-Hf and Sm-Nd Geochronology

NASA Astrophysics Data System (ADS)

Vervoort, J. D.; Wang, D.; Johnson, T. A.

2017-12-01

Garnet geochronology provides important information on the timing and conditions of metamorphism. As a major indicator mineral formed during metamorphism, its direct dating can not only help establish the timing of metamorphism, provide the "t" for P-T-t paths, but also, if the dated garnet can be placed in a textural context, can provide information on the timing of deformational features. With advances in chemistry and mass spectrometry, garnet Lu-Hf and Sm-Nd geochronology has become an important geochronological tool and we can now reliably (if not routinely) date a wide variety of garnet compositions formed under diverse conditions. In the course of dating a variety of lithologies using both Lu-Hf and Sm-Nd isotope systems, however, some intriguing results have emerged. Although there are many examples where the Lu-Hf and Sm-Nd systems give the same date within uncertainty, there are also many cases where these systems yield significantly different dates, and the differences between these dates can be considerable—many 10's of Ma of and even 100's of Ma. For example, in garnet-bearing Mesoproterozoic gneisses from across the Blue Ridge Province in Virginia, both Lu-Hf and Sm-Nd analyses (determined on the same solutions) define narrow time spans, but with the Sm-Nd dates systematically younger (for orthogneisses Lu-Hf dates are 1032 to 1019 Ma whereas Sm-Nd dates are 965 to 949 Ma—a difference of 67 to 80 Ma). There are many other examples of systematically younger Sm-Nd garnet dates in both the literature and with our ongoing research. Potential explanations for these differences include: 1) strong partitioning of Lu into garnet during growth yielding ages weighted toward the beginning of growth; 2) faster Lu diffusion from high Lu regions after garnet formation, potentially leading to isochron rotation and anomalously old Lu-Hf dates; and 3) differences in closure temperatures of the two isotope systems. We will review several examples of divergent Lu

Electronic, ductile, phase transition and mechanical properties of Lu-monopnictides under high pressures.

PubMed

Gupta, Dinesh C; Bhat, Idris Hamid

2013-12-01

The structural, elastic and electronic properties of lutatium-pnictides (LuN, LuP, LuAs, LuSb, and LuBi) were analyzed by using full-potential linearized augmented plane wave within generalized gradient approximation in the stable rock-salt structure (B1 phase) with space group Fm-3m and high-pressure CsCl structure (B2 phase) with space group Pm-3m. Hubbard-U and spin-orbit coupling were included to predict correctly the semiconducting band gap of LuN. Under compression, these materials undergo first-order structural transitions from B1 to B2 phases at 241, 98, 56.82, 25.2 and 32.3 GPa, respectively. The computed elastic properties show that LuBi is ductile by nature. The electronic structure calculations show that LuN is semiconductor at ambient conditions with an indirect band gap of 1.55 eV while other Lu-pnictides are metallic. It was observed that LuN shows metallization at high pressures. The structural properties, viz, equilibrium lattice constant, bulk modulus and its pressure derivative, transition pressure, equation of state, volume collapse, band gap and elastic moduli, show good agreement with available data.

Growth and luminescent properties of Lu2SiO5 and Lu2SiO5:Ce single crystalline films

NASA Astrophysics Data System (ADS)

Zorenko, Yu; Nikl, M.; Gorbenko, V.; Mares, J. A.; Savchyn, V.; Voznyak, T.; Solsky, I.; Grynyov, B.; Sidletskiy, O.; Kurtsev, D.; Beitlerova, A.; Kucerkova, R.

2010-11-01

Single crystalline films (SCF) of Lu2SiO5 (LSO) and Lu2SiO5:Ce (LSO:Ce) silicates with thickness of 2.5-21 μm were crystallised by liquid phase epitaxy method onto undoped LSO substrates from melt-solution based on PbO-B2O3 flux. The luminescence and scintillation properties of LSO and LSO:Ce SCFs were compared with the properties of a reference LSO:Ce and LYSO:Ce crystals. The light yield (LY) of LSO and LSO:Ce SCF reaches up 30 % and 145 %, respectively, of that of a reference LSO:Ce crystal under excitation by α-particles of 241Am source (5.5 MeV). We found that the luminescence spectrum of LSO:Ce SCF is red-shifted with respect to the spectrum of a reference LSO:Ce crystal. Differences in luminescence properties of LSO:Ce SCF and single crystal are explained by the different distribution of Ce3+ over the Lu1 and Lu2 positions of LSO host and are also due to Pb2+ contamination in the former.

Radiation exposure after 177Lu-DOTATATE and 177Lu-PSMA-617 therapy.

PubMed

Mair, Christian; Warwitz, Boris; Fink, Katharina; Scarpa, Lorenza; Nilica, Bernhard; Maffey-Steffan, Johanna; Buxbaum, Sabine; Virgolini, Irene J

2018-05-23

As radionuclide therapy is gaining importance in palliative treatment of patients suffering from neuroendocrine tumour (NET) as well as castration resistant prostate cancer (CRPC), the radiation protection of patients, staff, family members and the general public is of increasing interest. Here, we determine patient discharge dates according to European guidelines. In 40 patients with NET and 25 patients with CRPC organ and tumour doses based on the MIRD concept were calculated from data obtained during the first therapy cycle. Planar whole body images were recorded at 0.5, 4, 20, 68 und 92 h postinjection. Residence times were calculated from the respective time-activity-curves based on the conjugated view method. Residence times for critical organs were fitted into the commercially available OLINDA software to calculate the organ doses. The doses of tumours and salivary glands were calculated via their self-irradiation by approximation with spheres of equivalent volume. Kidney volumes were gained by organ segmentation, volumes of all other organs were estimated by means of OLINDA and hence were lean body mass corrected. Out of the whole body curves reference points for patient discharge were estimated. In patients with NET discharge dates could be properly estimated from dosimetric data, which is not only crucial for radiation protection, but also makes therapy planning easier. For 177 Lu-PSMA-617 ligand therapy it is difficult to seriously estimate a generalized discharge date due to large interpatient variation resulting from different tumor loads and heavy pre-treatment. Patient release is predictable for 177 Lu-DOTATATE therapy but not for 177 Lu-PSMA ligand therapy.

Energy Transfer Processes in (Lu,Gd)AlO3:Ce

DTIC Science & Technology

2001-01-01

studies on energy transfer processes in Ce-activated Lu, Y and Gd aluminum perovskite crystals that contribute to production of scintillation light in...LuAIO3, GdA10 3, cerium, scintillators, VUV spectroscopy, luminescence, time profiles, energy transfer 1. INTRODUCTION The yttrium aluminum perovskite...The Czochralski-grown monocrystals of LuAP:Ce were first evaluated in a garnet -free perovskite phase by Lempicki et al. in 1994 .4 More detailed

177Lu-labeled Gold Nanoparticles for Radiation Therapy of Locally Advanced Breast Cancer

NASA Astrophysics Data System (ADS)

Yook, Simmyung

Locally advanced breast cancer (LABC) occurs in about 10-15% of patients diagnosed with breast cancer (BC) and 30% of these patients have triple negative breast cancer (TNBC) that are often epidermal growth factor receptor (EGFR)-positive. The goal of the proposed research was design and evaluate preclinically a novel radiation nanomedicine for LABC composed of EGFR-targeted gold nanoparticles (AuNP) by covalently conjugating panitumumab and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) complexing 177Lu incorporated into a metal-chelating polymer (MCP) (177 Lu-T-AuNP) which could be used as a neoadjuvant treatment to improve the outcome of patients with LABC. 177Lu-T-AuNP were efficiently internalized by EGFR-positive BC cells and were significantly more effective than 177Lu-labeled and non-targeted (NT)-AuNP for killing these cells. For radiation treatment of EGFR-positive tumours, both 177Lu-T-AuNP and 177Lu-NT-AuNP were intratumourally (i.t.) injected into athymic mice with MDA-MB-468 BC xenografts for comparison. Biodistribution studies showed that 177Lu-T-AuNPs exhibited 2-fold higher tumour retention than 177Lu-NT-AuNPs following i.t. injection at 48 h p.i. Both forms of radiolabeled AuNP were highly effective for inhibiting tumour growth without normal organ toxicity due to local tumour retention of both form of AuNP. To minimize the displacement of 177Lu-labeled MCP from AuNP, polyethylene glycol (PEG) ligands presenting a disulfide [ 177Lu-DOTA-PEG-ortho-pyridyl disulfide (OPSS)], a lipoic acid (LA) [177Lu-DOTA-PEG-lipoic acid (LA)] or multi-LA [PEG- pGlu(177Lu-DOTA)8-LA4] for multivalent binding were synthesized and the stability of MCP-AuNP complexes determined. In vitro challenge study with thiol-containing molecules or human plasma, PEG-pGlu(DOTA)8-LA4-AuNP were most stable. In whole body elimination study, elimination of radioactivity due to displacement of 177Lu-MCP from AuNP in mice injected with 177Lu-DOTA-PEG-OPSS-AuNP was more

Evaluation of root-knot nematode disease control and plant growth promotion potential of biofertilizer Ning shield on Trichosanthes kirilowii in the field.

PubMed

Jiang, Chun-Hao; Xie, Ping; Li, Ke; Xie, Yue-Sheng; Chen, Liu-Jun; Wang, Jin-Suo; Xu, Quan; Guo, Jian-Hua

Biofertilizer Ning shield was composed of different strains of plant growth promotion bacteria. In this study, the plant growth promotion and root-knot nematode disease control potential on Trichosanthes kirilowii in the field were evaluated. The application of Ning shield significantly reduced the diseases severity caused by Meloidogyne incognita, the biocontrol efficacy could reached up to 51.08%. Ning shield could also promote the growth of T. kirilowii in the field by increasing seedling emergence, height and the root weight. The results showed that the Ning shield could enhance the production yield up to 36.26%. Ning shield could also promote the plant growth by increasing the contents of available nitrogen, phosphorus, potassium and organic matter, and increasing the contents of leaf chlorophyll and carotenoid pigment. Moreover, Ning shield could efficiently enhance the medicinal compositions of Trichosanthes, referring to the polysaccharides and trichosanthin. Therefore, Ning shield is a promising biofertilizer, which can offer beneficial effects to T. kirilowii growers, including the plant growth promotion, the biological control of root-knot disease and enhancement of the yield and the medicinal quality. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

LU-HF Age and Isotope Systematics of ALH84001

NASA Technical Reports Server (NTRS)

Righter, M.; Lapen, T. J.; Brandon, A. D.; Beard, B. L.; Shafer, J. T.; Peslier, A. H.

2009-01-01

Allan Hills (ALH) 84001 is an orthopyroxenite that is unique among the Martian meteorites in having the oldest inferred crystallization age (approx..4.5 to 4.0 Gyr) [e.g., 1-6 and references therein 7]. Its ancient origin makes this stone a critical constraint on early history of Mars, in particular the evolution of different planetary crust and mantle reservoirs. However, because there is significant variability in reported crystallization ages, determination of initial isotope compositions is imprecise making assessment of planetary reservoirs difficult. Here we report a new Lu-Hf mineral isochron age, initial Hf-176/Hf-177 isotope composition, and inferred Martian mantle source compositions for ALH84001 that place constraints on longlived source reservoirs for the enriched shergottite suite of Martian meteorites including Shergotty, Zagami, NWA4468, NWA856, RBT04262, LAR06319, and Los Angeles. Sm-Nd isotope analyses are under way for the same mineral aliquots analyzed for Lu-Hf. The Lu-Hf system was utilized because Lu and Hf are both lithophile and refractory and are not easily redistributed during short-lived thermal pulses associated with shock metamorphism. Moreover, chromite has relatively modest Hf concentrations with very low Lu/Hf ratios [9] yielding tight constraints on initial Hf-176/Hf-177 isotope compositions

Comparison of structural and electrical properties of Lu{sub 2}O{sub 3} and Lu{sub 2}TiO{sub 5} gate dielectrics for α-InGaZnO thin-film transistors

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

Pan, Tung-Ming, E-mail: tmpan@mail.cgu.edu.tw; Chen, Ching-Hung; Her, Jim-Long

We compared the structural properties and electrical characteristics of high-κ Lu{sub 2}O{sub 3} and Lu{sub 2}TiO{sub 5} gate dielectrics for amorphous indium-gallium-zinc oxide (α-InGaZnO) thin-film transistor (TFT) applications. The Lu{sub 2}O{sub 3} film has a strong Lu{sub 2}O{sub 3} (400) peak in the X-ray diffraction pattern, while the Lu{sub 2}TiO{sub 5} sample shows a relatively weak Lu{sub 2}TiO{sub 5} (102) peak. Atomic force microscopy reveals that the Lu{sub 2}O{sub 3} dielectric exhibits a rougher surface (about three times) than Lu{sub 2}TiO{sub 5} one. In X-ray photoelectron spectroscopy analysis, we found that the intensity of the O 1s peak corresponding tomore » Lu(OH){sub x} for Lu{sub 2}O{sub 3} film was higher than that of Lu{sub 2}TiO{sub 5} film. Furthermore, compared with the Lu{sub 2}O{sub 3} dielectric, the α-InGaZnO TFT using the Lu{sub 2}TiO{sub 5} gate dielectric exhibited a lower threshold voltage (from 0.43 to 0.25 V), a higher I{sub on}/I{sub off} current ratio (from 3.5 × 10{sup 6} to 1.3 × 10{sup 8}), a smaller subthreshold swing (from 276 to 130 mV/decade), and a larger field-effect mobility (from 14.5 to 24.4 cm{sup 2}/V s). These results are probably due to the incorporation of TiO{sub x} into the Lu{sub 2}O{sub 3} film to form a Lu{sub 2}TiO{sub 5} structure featuring a smooth surface, a low moisture absorption, a high dielectric constant, and a low interface state density at the oxide/channel interface. Furthermore, the stability of Lu{sub 2}O{sub 3} and Lu{sub 2}TiO{sub 5} α-InGaZnO TFTs was investigated under positive gate-bias stress (PGBS) and negative gate-bias stress (NGBS). The threshold voltage of the TFT performed under NGBS is more degradation than that under PGBS. This behavior may be attributed to the electron charge trapping at the dielectric–channel interface under PGBS, whereas the oxygen vacancies occurred in the InGaZnO under NGBS.« less

Gamma radiation exposure of accompanying persons due to Lu-177 patients

NASA Astrophysics Data System (ADS)

Kovan, Bilal; Demir, Bayram; Tuncman, Duygu; Capali, Veli; Turkmen, Cuneyt

2015-07-01

Neuroendocrine tumours (NET) are cancers usually observed and arisen in the stomach, intestine, pancreas and breathing system. Recently, radionuclide therapy applications with Lu-177 peptide compound are rapidly growing; especially effective clinical results are obtained in the treatment of well-differentiated and metastatic NET. In this treatment, Lu-177-DOTA, a beta emitter radioisotope in the radiopharmaceutical form, is given to the patient by intravenous way. Lu-177 has also gamma rays apart from beta rays. Gamma rays have 175 keV average energy and these gamma rays should be under the control in terms of radiation protection. In this study, we measured the exposure dose from the Lu-177 patient.

Beauty and physics: 13 important contributions of Chen Ning Yang

NASA Astrophysics Data System (ADS)

Shi, Yu

2014-06-01

In 2012, Chen Ning Yang received a 90th birthday gift in the form of a black cube inscribed with his 13 most important contributions, which cover four major areas of physics: statistical mechanics, condensed matter physics, particle physics and field theory. We briefly describe these 13 contributions and make general comments about Yang's distinctive style as a trailblazing leader in research.

Incorporation of Pr into LuAG ceramics

NASA Astrophysics Data System (ADS)

Marchewka, M. R.; Chapman, M. G.; Qian, H.; Jacobsohn, L. G.

2017-06-01

An investigation of the effects of Pr in (Lu1-xPrx)3Al5O12 (LuAG:Pr) ceramics was carried out by means of x-ray diffraction (XRD), energy dispersive x-ray spectroscopy (EDX), and attenuated total reflection Fourier transform infrared spectroscopy (ATR FTIR) measurements coupled with luminescence measurements. It was found that the Pr concentration that maximizes luminescence emission depends on the thermal processing conditions. While the calcined LuAG:Pr powder showed maximum luminescence emission for Pr concentrations between 0.18 and 0.33 at.%, maximum emission of ceramic bodies sintered at 1500 °C for 20 h was obtained with Pr concentrations between 0.018 and 0.18 at.%. Further, for short sintering times up to about 3 h, luminescence emission intensity is maximum for Pr concentrations around 0.33 at.%. Longer sintering times lead to the formation of PrAlO3 as a secondary phase, concomitant with a reduction of the intensity of luminescence emission.

LuIII Parvovirus Selectively and Efficiently Targets, Replicates in, and Kills Human Glioma Cells

PubMed Central

Paglino, Justin C.; Ozduman, Koray

2012-01-01

Because productive infection by parvoviruses requires cell division and is enhanced by oncogenic transformation, some parvoviruses may have potential utility in killing cancer cells. To identify the parvovirus(es) with the optimal oncolytic effect against human glioblastomas, we screened 12 parvoviruses at a high multiplicity of infection (MOI). MVMi, MVMc, MVM-G17, tumor virus X (TVX), canine parvovirus (CPV), porcine parvovirus (PPV), rat parvovirus 1A (RPV1A), and H-3 were relatively ineffective. The four viruses with the greatest oncolytic activity, LuIII, H-1, MVMp, and MVM-G52, were tested for the ability, at a low MOI, to progressively infect the culture over time, causing cell death at a rate higher than that of cell proliferation. LuIII alone was effective in all five human glioblastomas tested. H-1 progressively infected only two of five; MVMp and MVM-G52 were ineffective in all five. To investigate the underlying mechanism of LuIII's phenotype, we used recombinant parvoviruses with the LuIII capsid replacing the MVMp capsid or with molecular alteration of the P4 promoter. The LuIII capsid enhanced efficient replication and oncolysis in MO59J gliomas cells; other gliomas tested required the entire LuIII genome to exhibit enhanced infection. LuIII selectively infected glioma cells over normal glial cells in vitro. In mouse models, human glioblastoma xenografts were selectively infected by LuIII when administered intratumorally; LuIII reduced tumor growth by 75%. LuIII also had the capacity to selectively infect subcutaneous or intracranial gliomas after intravenous inoculation. Intravenous or intracranial LuIII caused no adverse effects. Intracranial LuIII caused no infection of mature mouse neurons or glia in vivo but showed a modest infection of developing neurons. PMID:22553327

LuIII parvovirus selectively and efficiently targets, replicates in, and kills human glioma cells.

PubMed

Paglino, Justin C; Ozduman, Koray; van den Pol, Anthony N

2012-07-01

Because productive infection by parvoviruses requires cell division and is enhanced by oncogenic transformation, some parvoviruses may have potential utility in killing cancer cells. To identify the parvovirus(es) with the optimal oncolytic effect against human glioblastomas, we screened 12 parvoviruses at a high multiplicity of infection (MOI). MVMi, MVMc, MVM-G17, tumor virus X (TVX), canine parvovirus (CPV), porcine parvovirus (PPV), rat parvovirus 1A (RPV1A), and H-3 were relatively ineffective. The four viruses with the greatest oncolytic activity, LuIII, H-1, MVMp, and MVM-G52, were tested for the ability, at a low MOI, to progressively infect the culture over time, causing cell death at a rate higher than that of cell proliferation. LuIII alone was effective in all five human glioblastomas tested. H-1 progressively infected only two of five; MVMp and MVM-G52 were ineffective in all five. To investigate the underlying mechanism of LuIII's phenotype, we used recombinant parvoviruses with the LuIII capsid replacing the MVMp capsid or with molecular alteration of the P4 promoter. The LuIII capsid enhanced efficient replication and oncolysis in MO59J gliomas cells; other gliomas tested required the entire LuIII genome to exhibit enhanced infection. LuIII selectively infected glioma cells over normal glial cells in vitro. In mouse models, human glioblastoma xenografts were selectively infected by LuIII when administered intratumorally; LuIII reduced tumor growth by 75%. LuIII also had the capacity to selectively infect subcutaneous or intracranial gliomas after intravenous inoculation. Intravenous or intracranial LuIII caused no adverse effects. Intracranial LuIII caused no infection of mature mouse neurons or glia in vivo but showed a modest infection of developing neurons.

177Lu-DOTA-Bevacizumab: Radioimmunotherapy Agent for Melanoma.

PubMed

Camacho, Ximena; Calzada, Victoria; Fernandez, Marcelo; Alonso, Omar; Chammas, Roger; Riva, Eloisa; Gambini, Juan Pablo; Cabral, Pablo

2017-01-01

Vascular endothelial growth factor (VEGF) is one of the classic factors to tumor-induced angiogenesis in several types, including melanoma. Bevacizumab is a humanized monoclonal antibody directed against VEGF. To radiolabel Bevacizumab with 177-Lutetium as a potential radioimmunotherapy agent for melanoma. Bevacizumab was derivatized with DOTA-NHS-ester at 4 ºC for 18 h. DOTABevacizumab was radiolabeled with 177LuCl3 (15 MBq/mg) at 37 ºC for 1 h. The studies were performed in healthy and B16F1 tumor-bearing C57BL/6J mice at 24 and 48 h (n = 5). Scinthigraphic imaging studies were performed at 24 h to determine the radiochemical stability, targeting specificity and pharmacokinetics of the 177Lutetium-labeled antibody. DOTA-Bevacizumab was efficiently labeled with 177LuCl3 at 37 °C. The in-vitro stability of labeled product was optimal over 72 h. In-vivo biodistribution studies showed a high liver and tumor uptake of 177Lu-DOTA-Bevacizumab, with tumor-to-muscle ratios of 11.58 and 6.37 at 24 and 48 h p.i. Scintigraphic imaging of melanoma tumor-bearing C57BL/6J mice showed liver and a high tumor selective uptake of 177Lu-DOTA-Bevacizumab at 24 h. Our results support the potential role of 177Lu-DOTA-Bevacizumab as a novel radioimmunotherapy agent for melanoma. We hope that these novel molecular imaging agents will open the path to new diagnostic and therapeutic strategies for Melanoma disease. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Lu-Hf CONSTRAINTS ON THE EVOLUTION OF LUNAR BASALTS.

USGS Publications Warehouse

Fujimaki, Hirokazu; Tatsumoto, Mistunobu

1984-01-01

The authors show that a cumulate-remelting model best explains the recently acquired data on the Lu-Hf systematics of lunar mare basalts. The authors model is first constructed using the Lu and Hf concentration data and it is then further strengthened by the Hf isotopic evidence. The authors also show that the similarity of MgO/FeO ratios and the Cr//2O//3 contents between high-Ti and low-Ti basalts, which have been given significance by A. E. Ringwood and D. H. Green are not important constraints for lunar basalt petrogenesis. The authors principal aim is to revive the remelting model for further consideration with the powerful constraints of Lu-Hf systematics of lunar basalts.

Multiparticle configurations of excited states in 155Lu

NASA Astrophysics Data System (ADS)

Carroll, R. J.; Hadinia, B.; Qi, C.; Joss, D. T.; Page, R. D.; Uusitalo, J.; Andgren, K.; Cederwall, B.; Darby, I. G.; Eeckhaudt, S.; Grahn, T.; Gray-Jones, C.; Greenlees, P. T.; Jones, P. M.; Julin, R.; Juutinen, S.; Leino, M.; Leppänen, A.-P.; Nyman, M.; Pakarinen, J.; Rahkila, P.; Sandzelius, M.; Sarén, J.; Scholey, C.; Seweryniak, D.; Simpson, J.

2016-12-01

Excited states in the neutron-deficient N =84 nuclide 155Lu have been populated by using the 102Pd(58Ni,α p ) reaction. The 155Lu nuclei were separated by using the gas-filled recoil ion transport unit (RITU) separator and implanted into the Si detectors of the gamma recoil electron alpha tagging (GREAT) spectrometer. Prompt γ -ray emissions measured at the target position using the JUROGAM Ge detector array were assigned to 155Lu through correlations with α decays measured in GREAT. Structures feeding the (11 /2-) and (25 /2-)α -decaying states have been revised and extended. Shell-model calculations have been performed and are found to reproduce the excitation energies of several of the low-lying states observed to within an average of 71 keV. In particular, the seniority inversion of the 25 /2- and 27 /2- states is reproduced.

Phase 3 Trial of 177Lu-Dotatate for Midgut Neuroendocrine Tumors.

PubMed

Strosberg, Jonathan; El-Haddad, Ghassan; Wolin, Edward; Hendifar, Andrew; Yao, James; Chasen, Beth; Mittra, Erik; Kunz, Pamela L; Kulke, Matthew H; Jacene, Heather; Bushnell, David; O'Dorisio, Thomas M; Baum, Richard P; Kulkarni, Harshad R; Caplin, Martyn; Lebtahi, Rachida; Hobday, Timothy; Delpassand, Ebrahim; Van Cutsem, Eric; Benson, Al; Srirajaskanthan, Rajaventhan; Pavel, Marianne; Mora, Jaime; Berlin, Jordan; Grande, Enrique; Reed, Nicholas; Seregni, Ettore; Öberg, Kjell; Lopera Sierra, Maribel; Santoro, Paola; Thevenet, Thomas; Erion, Jack L; Ruszniewski, Philippe; Kwekkeboom, Dik; Krenning, Eric

2017-01-12

Patients with advanced midgut neuroendocrine tumors who have had disease progression during first-line somatostatin analogue therapy have limited therapeutic options. This randomized, controlled trial evaluated the efficacy and safety of lutetium-177 ( 177 Lu)-Dotatate in patients with advanced, progressive, somatostatin-receptor-positive midgut neuroendocrine tumors. We randomly assigned 229 patients who had well-differentiated, metastatic midgut neuroendocrine tumors to receive either 177 Lu-Dotatate (116 patients) at a dose of 7.4 GBq every 8 weeks (four intravenous infusions, plus best supportive care including octreotide long-acting repeatable [LAR] administered intramuscularly at a dose of 30 mg) ( 177 Lu-Dotatate group) or octreotide LAR alone (113 patients) administered intramuscularly at a dose of 60 mg every 4 weeks (control group). The primary end point was progression-free survival. Secondary end points included the objective response rate, overall survival, safety, and the side-effect profile. The final analysis of overall survival will be conducted in the future as specified in the protocol; a prespecified interim analysis of overall survival was conducted and is reported here. At the data-cutoff date for the primary analysis, the estimated rate of progression-free survival at month 20 was 65.2% (95% confidence interval [CI], 50.0 to 76.8) in the 177 Lu-Dotatate group and 10.8% (95% CI, 3.5 to 23.0) in the control group. The response rate was 18% in the 177 Lu-Dotatate group versus 3% in the control group (P<0.001). In the planned interim analysis of overall survival, 14 deaths occurred in the 177 Lu-Dotatate group and 26 in the control group (P=0.004). Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9%, respectively, of patients in the 177 Lu-Dotatate group as compared with no patients in the control group, with no evidence of renal toxic effects during the observed time frame. Treatment with 177 Lu

Optimization of irradiation conditions for {sup 177}Lu production at the LVR-15 research reactor

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

Lahodova, Z.; Viererbl, L.; Klupak, V.

2012-07-01

The use of lutetium in medicine has been increasing over the last few years. The {sup 177}Lu radionuclide is commercially available for research and test purposes as a diagnostic and radiotherapy agent in the treatment of several malignant tumours. The yield of {sup 177}Lu from the {sup 176}Lu(n,{gamma}){sup 177}Lu nuclear reaction depends significantly on the thermal neutron fluence rate. The capture cross-sections of both reaction {sup 176}Lu(n,{gamma}){sup 177}Lu and reaction {sup 177}Lu(n,{gamma}){sup 178}Lu are very high. Therefore a burn-up of target and product nuclides should be taken into account when calculating {sup 177}Lu activity. The maximum irradiation time, when themore » activity of the {sup 177}Lu radionuclide begins to decline, was found for different fluence rates. Two vertical irradiation channels at the LVR-15 nuclear research reactor were compared in order to choose the channel with better irradiation conditions, such as a higher thermal neutron fluence rate in the irradiation volume. In this experiment, lutetium was irradiated in a titanium capsule. The influence of the Ti capsule on the neutron spectrum was monitored using activation detectors. The choice of detectors was based on requirements for irradiation time and accurate determination of thermal neutrons. The following activation detectors were selected for measurement of the neutron spectrum: Ti, Fe, Ni, Co, Ag and W. (authors)« less

Comparative vectorial efficiency of Lutzomyia evansi and Lu. longipalpis for transmitting Leishmania chagasi.

PubMed

Montoya-Lerma, J; Cadena, H; Oviedo, M; Ready, P D; Barazarte, R; Travi, B L; Lane, R P

2003-01-01

The infection rates and development of Leishmania chagasi in two sandfly species, Lutzomyia evansi and Lutzomyia longipalpis, were evaluated under natural and experimental conditions. Natural infection rates of Lu. evansi in San Andrés de Sotavento (Colombia) and Montañas de Peraza (Venezuela) (0.05 and 0.2%, respectively) were similar to those previously recorded for this species in Colombia and Venezuela and for Lu. longipalpis in many foci of American Visceral Leishmaniasis (AVL). Both sand fly species were able to support the development of two Colombian strains of L. chagasi experimentally acquired from dogs, hamsters or membrane feeders. However, the experimental infection rates and the sequence of parasite development in the guts of these sand flies revealed that parasite colonisation, differentiation, migration and attachment were more frequent and uniform in Lu. longipalpis than in Lu. evansi. This is consistent with a more recent association between L. chagasi and Lu. evansi, and these results might help to explain the irregularity of AVL outbreaks in foci where Lu. evansi has been reported as the sole vector. Copyright 2002 Elsevier Science B.V.

The success and complementarity of Sm-Nd and Lu-Hf garnet geochronology

NASA Astrophysics Data System (ADS)

Baxter, E. F.; Scherer, E. E.

2013-12-01

Garnet's potential as a direct chronometer of tectonometamorphic processes and conditions was first realized over 30 years ago. Since then, the Sm-Nd and Lu-Hf systems have emerged as the most effective, with both permitting age precision < ×1 Myr. Both have proven successful not merely in dating garnet growth itself, but rather in constraining the ages, durations, and rates of particular earth processes or conditions that can be directly linked to garnet growth via chemical, thermodynamic, or petrographic, means. Appreciating important differences between Sm-Nd and Lu-Hf in terms of contaminant phases, partitioning, daughter element diffusivity, and isotopic analysis makes these two systems powerfully complementary when used and interpreted in concert. Well established, robust analytical methods mitigate the effects of ubiquitous mineral inclusions (monazite is most significant for Sm-Nd; zircon is most significant for Lu-Hf), improving the precision and accuracy of garnet dates from both systems. Parent-daughter ratios tend to be higher for Lu-Hf leading to the potential for better age precision in general. The Lu-176 decay rate is faster than Sm-147, meaning that Lu-Hf provides better age precision potential for young (Cenozoic) samples. However, Sm-Nd provides better precision potential for older (Precambrian) samples primarily because of the higher precisions on the parent-daughter ratios (i.e., 147Sm/144Nd) that can be achieved by ID-TIMS analysis. For dating microsampled zones or growth rings in single garnet crystals, Sm-Nd has proven most successful owing to more uniform distribution of Sm, and established methods to measure <10 ng quantities of Nd at high precision via TIMS. However, new MC-ICP-MS sample introduction technologies are closing this gap for small samples. For analyses of bulk garnet that grew over a protracted interval, Lu-Hf dates are expected to be older than Sm-Nd dates owing to differences in Lu and Sm zonation (i.e. Lu tends to be

Measurement of 173Lu(n,γ) Cross Sections at DANCE

NASA Astrophysics Data System (ADS)

Roig, O.; Theroine, C.; Ebran, A.; Méot, V.; Bond, E. M.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Jandel, M.; Nortier, F. M.; O'Donnell, J. M.; Rundberg, R. S.; Taylor, W. A.; Ullmann, J. L.; Vieira, D. J.

2014-05-01

A highly gamma-radioactive target, 3.7 GBq, of 173Lu isotope was placed inside the DANCE array (Detector for Advanced Neutron Capture Experiments) at Los Alamos to study the radiative neutron capture on an unstable isotope. The 173Lu element was produced by naturalHf(p,xn) reactions following by beta-decays at the Isotope Production Facility (IPF). Measurements of radiative neutron capture cross section on 173Lu were achieved at the Los Alamos Neutron Science Center (LANSCE) spallation neutron source facility over the neutron energy range from thermal up to 1 keV. A special configuration was necessary to perform the experiment using the DANCE [1] array due to the high gamma activity of the target. We will report on the target production, the experiment and the results obtained for the radiative neutron capture on 173Lu. The radiative capture cross section was obtained for the first time on this unstable nucleus. Some resonances have been characterized. A comparison with a recent data evaluation is presented.

Synthesis of Er-doped Lu2O3 nanoparticles and transparent ceramics

NASA Astrophysics Data System (ADS)

Serivalsatit, K.; Wasanapiarnpong, T.; Kucera, C.; Ballato, J.

2013-05-01

Transparent rare earth-doped Lu2O3 ceramics have received much attention for use in solid-state scintillator and laser applications. The fabrication of these ceramics, however, requires ultrafine and uniform powders as precursors. Presented here is the synthesis of Er-doped Lu2O3 nanopowders by a solution precipitation method using Er-doped lutetium sulfate solution and hexamethylenetetramine as a precipitant and the fabrication of Er-doped Lu2O3 transparent ceramics from these nanopowders. The precipitated precursors were calcined at 1100 °C for 4 h in order to convert the precursors into Lu2O3 nanoparticles with an average particle size of 60 nm. Thermal decomposition and phase evolution of the precursors were studied by simultaneous thermal analysis (STA), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Er-doped Lu2O3 transparent ceramics were fabricated from these nanopowders using vacuum sintering followed by hot isostatic pressing at 1700 °C for 8 h. The transparent ceramics exhibit an optical transmittance of 78% at a wavelength of 1.55 μm.

Characterization of Pr:LuAG scintillating crystals for X-ray spectroscopy

NASA Astrophysics Data System (ADS)

Bertoni, R.; Bonesini, M.; Cervi, T.; Clemenza, M.; De Bari, A.; Falcone, A.; Mazza, R.; Menegolli, A.; Nastasi, M.; Rossella, M.

2016-07-01

The main features of the Pr doped Lu3Al5O12 (Pr:LuAG) scintillating crystals for X-ray spectroscopy applications have been studied using different radioactive sources and photo-detectors. Pr:LuAG is cheaper, compared to a Germanium detector, but with remarkable properties which make it useful for many applications, from fundamental physics measurements to the PET imaging for medical purposes: high density, elevate light yield, fast response, high energy resolution, no hygroscopicity. A sample of Pr:LuAG crystals with 14 mm×14 mm surface area and 13 mm thickness and a NaI crystal of the same surface and 26 mm thickness used as a reference have been characterized with several radioactive sources, emitting photons in the range 100-1000keV. Different light detectors were adopted for the Pr:LuAG studies, sensitive to its UV emission (peak at 310 nm): a 3 in. PMT (Hamamatsu R11065) and new arrays of Hamamatsu SiPM S13361, with siliconic resin as a window. Preliminary results are presented on the performance of the Pr:LuAG crystals, to be mounted in a 2 × 2 array to be tested in the 2015 run of the FAMU experiment at RIKEN-RAL muon facility. The goal is the detection of the X-rays (around 130 keV) emitted during the de-excitation processes of the muonic hydrogen after the excitation with an IR laser with wavelength set at the resonance of the hyperfine splitting, to measure the muonic atom proton radius with unprecedented precision.

Superconductivity in single crystalline ThBe13 and LuBe13

NASA Astrophysics Data System (ADS)

Uhlířová, Klára; Miura, Naoyuki; Tkáč, Vladimír; Prokleška, Jan; Chrobak, Maciej; Tarnawski, Zbigniew; Hidaka, Hiroyki; Yanagisawa, Tatsuya; Sechovský, Vladimír; Amitsuka, Hiroshi

2018-05-01

Single crystals of ThBe13 and LuBe13 have been prepared using aluminum flux method. The crystals structure of both compounds was confirmed to be cubic of the NaZn13-type with the lattice parameters a = 10.183(6) Å and a = 10.395(3) Å for LuBe13 and ThBe13, respectively. The low temperature measurements of electrical resistance and ac susceptibility have revealed a BCS-type of superconductivity in ThBe13 below Tc = 125 mK. LuBe13 has been found to be superconducting below Tc = 630 mK.

Spectroscopic characterisation of Er-doped LuVO4 single crystals

NASA Astrophysics Data System (ADS)

Lisiecki, R.; Dominiak-Dzik, G.; Solarz, P.; Strzęp, A.; Ryba-Romanowski, W.; Łukasiewicz, T.

2010-12-01

The LuVO4:Er single crystals were grown by the Czochralski technique. The crystal-field split energy levels of Er3+ ion were derived experimentally employing absorption and emission spectra measured at T=10 K. The Judd-Ofelt phenomenological method was used to estimate intensity parameters, radiative lifetimes and branching ratios of luminescence. The excited state dynamics of the LuVO4:Er systems was investigated and experimental lifetimes of emitting levels were measured. The emission cross section of the 4I13/2→4I15/2 transition in the infrared was calculated by the Füchtbauer-Ladenburg method. The gain cross section, estimated for several inverse-population parameters, allowed us to evaluate a potential laser activity of the LuVO4:Er system at 1.6 μm. Also, the potential range of the optical pumping was assessed based on absorption spectra achieved at the room temperature. The optical losses related to the green up-converted emission, encountered under the 978 nm excitation between 300 and 670 K were indicated and discussed. Spectroscopic peculiarities of the Er3+-doped LuVO4 crystal were discussed in relation to optical properties of the YVO4:Er and GdVO4:Er crystals. Taking into account the high quantum efficiency of the 4I13/2 level, and satisfactory absorption and emission features, the LuVO4:Er crystal can be considered as a promising active material for laser operation near 1.6 μm.

Negative thermal expansion and anomalies of heat capacity of LuB 50 at low temperatures

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

Novikov, V. V.; Zhemoedov, N. A.; Matovnikov, A. V.

2015-07-20

Heat capacity and thermal expansion of LuB 50 boride were experimentally studied in the 2–300 K temperature range. The data reveal an anomalous contribution to the heat capacity at low temperatures. The value of this contribution is proportional to the first degree of temperature. It was identified that this anomaly in heat capacity is caused by the effect of disorder in the LuB 50 crystalline structure and it can be described in the soft atomic potential model (SAP). The parameters of the approximation were determined. The temperature dependence of LuB 50 heat capacity in the whole temperature range was approximatedmore » by the sum of SAP contribution, Debye and two Einstein components. The parameters of SAP contribution for LuB 50 were compared to the corresponding values for LuB 66, which was studied earlier. Negative thermal expansion at low temperatures was experimentally observed for LuB 50. The analysis of the experimental temperature dependence for the Gruneisen parameter of LuB 50 suggested that the low-frequency oscillations, described in SAP mode, are responsible for the negative thermal expansion. As a result, the glasslike character of the behavior of LuB 50 thermal characteristics at low temperatures was confirmed.« less

Radiative neutron capture cross sections on 176Lu at DANCE

NASA Astrophysics Data System (ADS)

Roig, O.; Jandel, M.; Méot, V.; Bond, E. M.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Keksis, A. L.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.

2016-03-01

The cross section of the neutron capture reaction 176Lu(n ,γ ) has been measured for a wide incident neutron energy range with the Detector for Advanced Neutron Capture Experiments at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be (1912 ±132 ) b for one of the Lu natural isotopes, 176Lu. The resonance part was measured and compared to the Mughabghab's atlas using the R -matrix code, sammy. At higher neutron energies the measured cross sections are compared to ENDF/B-VII.1, JEFF-3.2, and BRC evaluated nuclear data. The Maxwellian averaged cross sections in a stellar plasma for thermal energies between 5 keV and 100 keV were extracted using these data.

Tidal triggering of earthquakes in the Ning'er area of Yunnan Province, China

NASA Astrophysics Data System (ADS)

Xie, Chaodi; Lei, Xinglin; Zhao, Xiaoyan; Ma, Qingbo; Yang, Simeng; Wang, Yingnan

2017-05-01

To investigate the potential effect of tidal modulation on the seismicity in the Ning'er area, a seismically and geothermally active zone in Yunnan Province, China, we studied the correlation between Earth tides and the occurrence of M ≥ 6.0 earthquakes dating back to 1970, as well as their aftershock sequences, using theoretically calculated tidal stresses and a statistical test. The results show a significant correlation between Earth tides and the occurrence of earthquakes. Six of seven main events occurred when the Earth tide increased the Coulomb failure stress on the source fault. Four main events occurred in a narrow range of phase angle corresponding to the maximum loading rate of tidal stress. Furthermore, the histories of the aftershock sequence as a function of the tidal phases demonstrate clear tidal modulation with a high significance. Thus, we conclude that Earth tides have a clear role in triggering (or modulating) the rupture of the fault systems in the Ning'er area.

Investigation of luminescence from LuAG: Mn4+ for physiological temperature sensing

NASA Astrophysics Data System (ADS)

Li, Fei; Cai, Jiajia; Chi, FengFeng; Chen, Yonghu; Duan, Changkui; Yin, Min

2017-04-01

Optical thermometry based on luminescent materials has garnered much attention due to its many advantages. But higher sensitivity is still expected in physiological temperature range which is of special significance in medicine and biology. For this purpose, quadrivalent manganese doped lutetium aluminum garnet, Lu3Al5O12: Mn4+, or simply LuAG: Mn4+, has been successfully synthesized by sol-gel method and its temperature dependent luminescence has been investigated in the present work. Compared to the common red emission phosphors Y3Al5O12: Mn4+ (YAG:Mn4+) with same structure, LuAG:Mn4+ has a stronger crystal field strength and a higher thermal-quenching activation energy (ΔE) of 5732 cm-1. Rapid thermal quenching of the Mn4+ luminescence occurred above room temperature around 90 °C for our LuAG:Mn4+ sample. Temperature dependent decay curves of Mn4+ emission from LuAG:Mn4+ revealed that an extraordinary high sensitivity can be achieved from luminescence lifetime measurements covering physiological temperature range with a sensitivity of 3.75% K-1 at 38 °C.

A routine high-precision method for Lu-Hf isotope geochemistry and chronology

USGS Publications Warehouse

Patchett, P.J.; Tatsumoto, M.

1981-01-01

A method for chemical separation of Lu and Hf from rock, meteorite and mineral samples is described, together with a much improved mass spectrometric running technique for Hf. This allows (i) geo- and cosmochronology using the176Lu???176Hf+??- decay scheme, and (ii) geochemical studies of planetary processes in the earth and moon. Chemical yields for the three-stage ion-exchange column procedure average 90% for Hf. Chemical blanks are <0.2 ng for Lu and Hf. From 1 ??g of Hf, a total ion current of 0.5??10-11 Ampere can be maintained for 3-5 h, yielding 0.01-0.03% precision on the ratio176Hf/177Hf. Normalisation to179Hf/177Hf=0.7325 is used. Extensive results for the Johnson Matthey Hf standard JMC 475 are presented, and this sample is urged as an international mass spectrometric standard; suitable aliquots, prepared from a single batch of JMC 475, are available from Denver. Lu-Hf analyses of the standard rocks BCR-1 and JB-1 are given. The potential of the Lu-Hf method in isotope geochemistry is assessed. ?? 1980 Springer-Verlag.

2-micron lasing in Tm:Lu2O3 ceramic: initial operation

NASA Astrophysics Data System (ADS)

Vetrovec, John; Filgas, David M.; Smith, Carey A.; Copeland, Drew A.; Litt, Amardeep S.; Briscoe, Eldridge; Schirmer, Ernestina

2018-03-01

We report on initial lasing of Tm:Lu2O3 ceramic laser with tunable output in the vicinity of 2 μm. Tm:Lu2O3 ceramic gain materials offer a much lower saturation fluence than the traditionally used Tm:YLF and Tm:YAG materials. The gain element is pumped by 796 nm diodes via a "2-for-1" crossrelaxation energy transfer mechanism, which enables high efficiency. The high thermal conductivity of the Lu2O3 host ( 18% higher than YAG) in combination with low quantum defect of 20% supports operation at high-average power. Konoshima's ceramic fabrication process overcomes the scalability limits of single crystal sesquioxides. Tm:Lu2O3 offers wide-bandwidth amplification of ultrashort pulses in a chirped-pulse amplification (CPA) system. A laser oscillator was continuously tuned over a 230 nm range from 1890 to 2120 nm while delivering up to 43W QCW output with up to 37% efficiency. This device is intended for initial testing and later seeding of a multi-pass edge-pumped disk amplifier now being developed by Aqwest which uses composite Tm:Lu2O3 disk gain elements.

Preparation of LuAG Powders with Single Phase and Good Dispersion for Transparent Ceramics Using Co-Precipitation Method

PubMed Central

Pan, Liangjie; Jiang, Benxue; Fan, Jintai; Yang, Qiuhong; Zhou, Chunlin; Zhang, Pande; Mao, Xiaojian; Zhang, Long

2015-01-01

The synthesis of pure and well dispersed lutetium aluminum garnet (LuAG) powder is crucial and important for the preparation of LuAG transparent ceramics. In this paper, high purity and well dispersed LuAG powders have been synthesized via co-precipitation method with lutetium nitrate and aluminum nitrate as raw materials. Ammonium hydrogen carbonate (AHC) was used as the precipitant. The influence of aging time, pH value, and dripping speed on the prepared LuAG powders were investigated. It showed that long aging duration (>15 h) with high terminal pH value (>7.80) resulted in segregation of rhombus Lu precipitate and Al precipitate. By decreasing the initial pH value or accelerating the dripping speed, rhombus Lu precipitate was eliminated and pure LuAG nano powders were synthesized. High quality LuAG transparent ceramics with transmission >75% at 1064 nm were fabricated using these well dispersed nano LuAG powders. PMID:28793510

Preparation of LuAG Powders with Single Phase and Good Dispersion for Transparent Ceramics Using Co-Precipitation Method.

PubMed

Pan, Liangjie; Jiang, Benxue; Fan, Jintai; Yang, Qiuhong; Zhou, Chunlin; Zhang, Pande; Mao, Xiaojian; Zhang, Long

2015-08-19

The synthesis of pure and well dispersed lutetium aluminum garnet (LuAG) powder is crucial and important for the preparation of LuAG transparent ceramics. In this paper, high purity and well dispersed LuAG powders have been synthesized via co-precipitation method with lutetium nitrate and aluminum nitrate as raw materials. Ammonium hydrogen carbonate (AHC) was used as the precipitant. The influence of aging time, pH value, and dripping speed on the prepared LuAG powders were investigated. It showed that long aging duration (>15 h) with high terminal pH value (>7.80) resulted in segregation of rhombus Lu precipitate and Al precipitate. By decreasing the initial pH value or accelerating the dripping speed, rhombus Lu precipitate was eliminated and pure LuAG nano powders were synthesized. High quality LuAG transparent ceramics with transmission >75% at 1064 nm were fabricated using these well dispersed nano LuAG powders.

Growth and luminescent properties of Lu 2SiO 5:Ce and (Lu 1- xGd x) 2SiO 5:Ce single crystalline films

NASA Astrophysics Data System (ADS)

Zorenko, Yu.; Gorbenko, V.; Savchyn, V.; Voznyak, T.; Grinyov, B.; Sidletskiy, O.; Kurtsev, D.; Fedorov, A.; Baumer, V.; Nikl, M.; Mares, J. A.; Beitlerova, A.; Prusa, P.; Kucera, M.

2011-12-01

Single crystalline films (SCF) of Lu 2SiO 5:Ce (LSO:Ce), (Lu 1- xGd x) 2SiO 5:Ce (LGSO:Ce) and LGSO:Ce,Tb orthosilicates with thickness of 2.5-21 μm were crystallized by liquid phase epitaxy method onto undoped LSO substrates from melt-solution based on PbO-B 2O 3 flux. The concentration of Gd was varied in the range of x=0.2-0.7 formula units (f.u.). In the case of LGSO:Ce SCF growth we do not use any additional doping for reducing the misfit between the SCF and substrate lattices. The luminescence and scintillation properties of LSO:Ce, LGSO:Ce and LGSO:Ce,Tb SCFs were mutually compared and confronted with the performance of reference LSO:Ce and LYSO:Ce crystals. With increasing Gd content the luminescence spectrum of LGSO:Ce SCF is gradually red-shifted with respect to that of LSO:Ce SCF. The LY of (Lu 1- xGd x)SO:Ce SCF becomes lower in comparison with that for LSO:Ce SC at increasing Gd content in the range of x=0.2-0.7 f.u. The peculiarities of luminescence properties of LSO:Ce and LGSO:Ce SCFs in comparison with crystal analogs are explained by the different distribution of Ce 3+ over Lu1 and Lu2 positions of LSO host and by the influence of Pb 2+ contamination coming from the flux used for the film growth.

Overview of Development and Formulation of ¹⁷⁷Lu-DOTA-TATE for PRRT.

PubMed

Breeman, Wouter A P; Chan, Ho Sze; de Zanger, Rory M S; Konijnenberg, Mark K; de Blois, Erik

2016-01-01

Peptide receptor radionuclide therapy (PRRT) using radiolabeled somatostatin analogs has become an established procedure for the treatment of patients suffering from inoperable neuroendocrine cancers over-expressing somatostatin receptors. Success of PRRT depends on the availability of the radiolabeled peptide with adequately high specific activity, so that required therapeutic efficacy can be achieved without saturating the limited number of receptors available on the target lesions. Specific activity of the radionuclide and the radiolabeled somatostatin analog are therefore an important parameters. Although these analogs have been investigated and improved, and successfully applied for PRRT for more than 15 years, there are still many possibilities for further improvements that fully exploit PRRT with 177Lu-DOTA-TATE. The here summarized data presented herein on increased knowledge of the components of 177Lu-DOTA-TATE (especially the purity of 177Lu and specific activity of 177Lu) and the reaction kinetics during labeling 177Lu-DOTA-TATE clearly show that the peptide dose and dose in GBq can be varied. Here we present an overview of the development, formulation and optimisation of 177Lu-DOTA-TATE, mainly addressing radiochemical parameters.

Scintillation properties of Pr-activated LuAlO 3

NASA Astrophysics Data System (ADS)

Drozdowski, Winicjusz; Wojtowicz, Andrzej J.; Wiśniewski, Dariusz; Łukasiewicz, Tadeusz; Kisielewski, Jarosław

2006-01-01

Praseodymium activated LuAlO 3 (LuAP) crystals have been grown using the Czochralski method at ITME, Warsaw. In this communication the measurements of radioluminescence (RL), low temperature thermoluminescence (TL), room temperature afterglow (AG), scintillation light yields (LY), and scintillation time profiles (STP), performed on polished 2 × 2 × 10 mm pixels with three Pr concentrations (0.003, 0.04, and 0.08 at.%), are reported. Two sets of samples are compared: (i) "as grown", and (ii) annealed in H 2 atmosphere.

Single-crystal study of the charge density wave metal LuNiC2

NASA Astrophysics Data System (ADS)

Steiner, S.; Michor, H.; Sologub, O.; Hinterleitner, B.; Höfenstock, F.; Waas, M.; Bauer, E.; Stöger, B.; Babizhetskyy, V.; Levytskyy, V.; Kotur, B.

2018-05-01

We report on single-crystal growth, single-crystal x-ray diffraction, physical properties, and density functional theory (DFT) electronic structure as well as Fermi surface calculations for two ternary carbides, LuCoC2 and LuNiC2. Electrical resistivity measurements reveal for LuNiC2 a charge density wave (CDW) transition at TCDW≃450 K and, for T >TCDW , a significant anisotropy of the electrical resistivity, which is lowest along the orthorhombic a axis. The analysis of x-ray superstructure reflections suggest a commensurate CDW state with a Peierls-type distortion of the Ni atom periodicity along the orthorhombic a axis. DFT calculations based on the CDW modulated monoclinic structure model of LuNiC2 as compared to results of the orthorhombic parent type reveal the formation of a partial CDW gap at the Fermi level which reduces the electronic density of states from N (EF)=1.03 states/eV f.u. without CDW to N (EF)=0.46 states/eV f.u. in the CDW state. The corresponding bare DFT Sommerfeld value of the latter, γDFTCDW=0.90 mJ/mol K2, reaches reasonable agreement with the experimental value γ =0.83 (5 ) mJ/mol K2 of LuNiC2. LuCoC2 displays a simple metallic behavior with neither CDW ordering nor superconductivity above 0.4 K. Its experimental Sommerfeld coefficient, γ =5.9 (1) mJ/mol K2, is in realistic correspondence with the calculated, bare Sommerfeld coefficient, γDFT=3.82 mJ/mol K2, of orthorhombic LuCoC2.

Stability and Biodistribution of Thiol-Functionalized and (177)Lu-Labeled Metal Chelating Polymers Bound to Gold Nanoparticles.

PubMed

Yook, Simmyung; Lu, Yijie; Jeong, Jenny Jooyoung; Cai, Zhongli; Tong, Lemuel; Alwarda, Ramina; Pignol, Jean-Philippe; Winnik, Mitchell A; Reilly, Raymond M

2016-04-11

We are studying a novel radiation nanomedicine approach to treatment of breast cancer using 30 nm gold nanoparticles (AuNP) modified with polyethylene glycol (PEG) metal-chelating polymers (MCP) that incorporate 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelators for complexing the β-particle emitter, (177)Lu. Our objective was to compare the stability of AuNP conjugated to MCP via a single thiol [DOTA-PEG-ortho-pyridyl disulfide (OPSS)], a dithiol [DOTA-PEG-lipoic acid (LA)] or multithiol end-group [PEG-pGlu(DOTA)8-LA4] and determine the elimination and biodistribution of these (177)Lu-labeled MCP-AuNP in mice. Stability to aggregation in the presence of thiol-containing dithiothreitol (DTT), L-cysteine or glutathione was assessed and dissociation of (177)Lu-MCP from AuNP in human plasma measured. Elimination of radioactivity from the body of athymic mice and excretion into the urine and feces was measured up to 168 h post-intravenous (i.v.) injection of (177)Lu-MCP-AuNP and normal tissue uptake was determined. ICP-AES was used to quantify Au in the liver and spleen and these were compared to (177)Lu. Our results showed that PEG-pGlu(DOTA)8-LA4-AuNP were more stable to aggregation in vitro than DOTA-PEG-LA-AuNP and both forms of AuNP were more stable to thiol challenge than DOTA-PEG-OPSS-AuNP. PEG-pGlu((177)Lu-DOTA)8-LA4 was the most stable in plasma. Whole body elimination of (177)Lu was most rapid for mice injected with (177)Lu-DOTA-PEG-OPSS-AuNP. Urinary excretion accounted for >90% of eliminated (177)Lu. All (177)Lu-MCP-AuNP accumulated in the liver and spleen. Liver uptake was lowest for PEG-pGlu((177)Lu-DOTA)8-LA4-AuNP but these AuNP exhibited the greatest spleen uptake. There were differences in Au and (177)Lu in the liver for PEG-pGlu((177)Lu-DOTA)8-LA4-AuNP. These differences were not correlated with in vitro stability of the (177)Lu-MCP-AuNP. We conclude that conjugation of AuNP with PEG-pGlu((177)Lu-DOTA)8-LA4 via a multithiol

Development of 177Lu-phytate Complex for Radiosynovectomy

PubMed Central

Yousefnia, Hassan; Jalilian, Amir Reza; Bahrami-Samani, Ali; Mazidi, Mohammad; Ghannadi Maragheh, Mohammad; Abbasi-Davani, Fereydoun

2013-01-01

Objective(s): In this work a new possible agent for radiosynovectomy has been targeted for articular pain palliation. Materials and Methods: Lu-177 of 2.6-3 GBq/mg specific activity was obtained by irradiation of natural Lu2O3 sample with thermal neutron flux of 4 × 1013 n.cm-2.s-1. The product was converted into chloride form which was further used for labeling of 177Lu-phytate complex and checked using ITLC (MeOH: H2O: acetic acid, 4: 4: 2, as mobile phase). The complex stability and viscosity were checked in the final solution up to seven days. The prepared complex solution (100 µCi/100 µl) was injected intra-articularly to male rat knee joint. Leakage of radioactivity from injection site and its distribution in organs were investigated up to seven days. Results: The complex was successfully prepared with high radiochemical purity (>99.9 %). Approximately, the whole injected dose has remained in injection site seven days after injection. Conclusion: The complex was proved to be a feasible agent for cavital radiotherapy in oncology and rheumatology. PMID:23826493

Synthesis of transparent Lu3Al5O12 ceramic by solid-state reaction method

NASA Astrophysics Data System (ADS)

Basyrova, L. R.; Maksimov, R. N.; Shitov, V. A.; Aleksandrov, E. O.

2017-09-01

Transparent polycrystalline Lu3Al5O12 (LuAG) ceramic was fabricated by solid-state reactive sintering a mixture of Lu2O3 nanoparticles synthesized by laser ablation and commercial Al2O3 powder. The obtained Lu2O3 nanoparticles exhibited a metastable monoclinic phase and were fully converted into a main cubic phase after calcination at 1100 °C for 1 h in air. The powders were mixed in ethanol with the addition of 0.5 wt% tetraethoxysilane (TEOS), dried in a rotary evaporator, and uniaxially pressed into pellet at 200 MPa. Transparent 2 mm thick LuAG ceramic sample with an average grain size of 9.6 µm and an optical transmittance of 30 % at a wavelength of 1080 nm was obtained after sintering at 1780 °C for 20 h under vacuum. The average volume of the scattering centers (380 ppm) in the obtained LuAG ceramic and their distribution along the sample depth was evaluated by the direct count method using an optical microscope.

Forward to cryogenic temperature: laser cooling of Yb: LuLiF crystal

NASA Astrophysics Data System (ADS)

Zhong, Biao; Luo, Hao; Lei, Yongqing; Shi, Yanling; Yin, Jianping

2017-06-01

The high quality Yb-doped fluoride crystals have broad prospects for optical refrigeration. We have laser cooled the Yb:LuLiF crystal to a temperature below the limit of current thermoelectric coolers ( 180 K). The 5% Yb:LuLiF crystal sample has a geometry of 2 mm×2 mm×5 mm and was supported by two fibers of 200 μm in diameter. They were placed in a 2×10-4 Pa vacuum chamber with an environment temperature of 294.5 K. The 1019 nm CW laser of power 38.7 W was adopted to irradiate the sample. The temperature of the sample was measured utilizing the DLT methods. After 20 minutes of laser irradiation, the 5% Yb:LuLiF crystal sample was cooled down to 182.4 K. By further optimizing experimental conditions and increasing the doped Yb concentration, the Yb:LuLiF crystal might be optically cooled below the cryogenic temperature of 123K in the near future.

Meteorite zircon constraints on the bulk Lu-Hf isotope composition and early differentiation of the Earth.

PubMed

Iizuka, Tsuyoshi; Yamaguchi, Takao; Hibiya, Yuki; Amelin, Yuri

2015-04-28

Knowledge of planetary differentiation is crucial for understanding the chemical and thermal evolution of terrestrial planets. The (176)Lu-(176)Hf radioactive decay system has been widely used to constrain the timescales and mechanisms of silicate differentiation on Earth, but the data interpretation requires accurate estimation of Hf isotope evolution of the bulk Earth. Because both Lu and Hf are refractory lithophile elements, the isotope evolution can be potentially extrapolated from the present-day (176)Hf/(177)Hf and (176)Lu/(177)Hf in undifferentiated chondrite meteorites. However, these ratios in chondrites are highly variable due to the metamorphic redistribution of Lu and Hf, making it difficult to ascertain the correct reference values for the bulk Earth. In addition, it has been proposed that chondrites contain excess (176)Hf due to the accelerated decay of (176)Lu resulting from photoexcitation to a short-lived isomer. If so, the paradigm of a chondritic Earth would be invalid for the Lu-Hf system. Herein we report the first, to our knowledge, high-precision Lu-Hf isotope analysis of meteorite crystalline zircon, a mineral that is resistant to metamorphism and has low Lu/Hf. We use the meteorite zircon data to define the Solar System initial (176)Hf/(177)Hf (0.279781 ± 0.000018) and further to identify pristine chondrites that contain no excess (176)Hf and accurately represent the Lu-Hf system of the bulk Earth ((176)Hf/(177)Hf = 0.282793 ± 0.000011; (176)Lu/(177)Hf = 0.0338 ± 0.0001). Our results provide firm evidence that the most primitive Hf in terrestrial zircon reflects the development of a chemically enriched silicate reservoir on Earth as far back as 4.5 billion years ago.

Expedition Seven Science Officer Lu with laptop

NASA Image and Video Library

2003-07-16

ISS007-E-10478 (16 July 2003) --- Astronaut Edward T. Lu, Expedition 7 NASA ISS science officer and flight engineer, uses a computer in the Destiny laboratory on the International Space Station (ISS).

A potencial theranostic agent for EGF-R expression tumors: (177)Lu-DOTA-nimotuzumab.

PubMed

Calzada, Victoria; Zhang, Xiuli; Fernandez, Marcelo; Diaz-Miqueli, Arlhee; Iznaga-Escobar, Normando; Deutscher, Susan L; Balter, Henia; Quinn, Thomas P; Cabral, Pablo

2012-10-01

In this work Nimotuzumab (monoclonal antibody, recognizes the EGF-R) was radiolabeled with (177)Lu as a potential cancer therapy radiopharmaceutical. In-vitro cell binding studies and in-vivo biodistribution and imaging studies were performed to determine the radiochemical stability, targeting specificity and pharmacokinetics of the (177)Lu-labeled antibody. Nimotuzumab was derivatized with DOTA-NHS at room temperature for 2 hours. DOTA-Nimotuzumab was radiolabeled with (177)LuCl3 (15 MBq/mg) at 37°C for 1 h. The radiochemical purity was assessed by ITLC, silica gel and by RP-HPLC. Binding specificity studies were performed with EGF-R positive A431 human epithelial carcinoma and EGF-R negative MDA-MB-435 breast carcinoma cells. Biodistribution studies were performed in healthy female CD-1 mice at 1 h, 4 h, 24 h, and A431 xenografted nude mice at 10 min, 1 h, 4 h, 24 h, 48 h, and 96 h. SPECT-CT imaging studies were performed in A431 xenografted mice at 24 h post injection. DOTA-Nimotuzumab was efficiently labeled with (177) LuCl(3) at 37°C. The in vitro stability of labeled product was optimal over 24 h in buffered saline and mouse serum. Specific recognition of EGF-R by (177)Lu-DOTA-Nimotuzumab was observed in A431 cell binding studies. Biodistribution studies demonstrated increasing tumor uptake of (177)Lu-DOTA-Nimotuzumab over time, with tumor to muscle ratios of 6.26, 10.68, and 18.82 at 4 h, 24 h, and 96 h post injection. Imaging of A431 xenografted mice showed high uptake in the tumor. (177)Lu-DOTA-Nimotuzumab has the potential to be a promising therapy agent, which may be useful in the treatment of patients with EGF-R positive cancer.

Uniform, luminescent Eu:LuF3 nanoparticles

NASA Astrophysics Data System (ADS)

Becerro, Ana I.; Gonzalez-Mancebo, Daniel; Ocaña, Manuel

2015-01-01

A simple procedure for the synthesis of orthorhombic, uniform, LuF3 particles with two different morphologies (rhombus- and cocoon-like) and nanometer and sub-micrometer size, respectively, is reported. The method consists in the aging, at 120 °C for 2 h, a solution containing [BMIM]BF4 ionic liquid (0.5 mL) and lutetium acetate (in the case of the rhombi) or lutetium nitrate (in the case of the cocoons) (0.02 M) in ethylene glycol (total volume 10 mL). This synthesis method was also adequate for the synthesis of Eu3+-doped LuF3 particles of both morphologies, whose luminescence properties were investigated in detail. The experimental observations reported herein suggest that these materials are suitable phosphors for optoelectronic as well as in vitro biotechnological applications.

Production of {sup 177}Lu, a potential radionuclide for diagnostic and therapeutic applications

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

Khandaker, Mayeen Uddin; Kassim, Hasan Abu; Haba, Hiromitsu

2015-04-24

{sup 177g}Lu (T{sub 1/2}=6.647d; E{sub β{sup −max}}=498.3KeV, I{sub β{sup −total}}=100%; E{sub γ} = 112.9498 keV, I{sub γ} = 6.17%; E{sub γ} = 208.3662 keV, I {sub γ} = 10.36%) is widely used in many clinical procedures due to its excellent decay characteristics. Production cross-sections of the {sup nat}Yb(d,x){sup 177g}Lu reactions have been measured from a 24-MeV deuteron energy down to the threshold by using a stacked-foil activation technique combined with high resolution γ-ray spectrometry. An overall good agreement is found with some of the earlier measurements, whereas a partial agreement is obtained with the theoretical data extracted from the TENDL-2013 library.more » Physical thick target yield for the {sup 177g}Lu radionuclide was deduced using the measured cross-sections. The deduced yield curves indicate that a low energy (<11 MeV) cyclotron and a highly enriched {sup 176}Yb target could be used to obtain {sup 177g}Lu with negligible impurity from {sup 177m}Lu.« less

Thermal, vibrational and optical properties of PrLuO3 interlanthanides from hydrothermally-derived precursors.

PubMed

Soares, Júlia C; Siqueira, Kisla P F; de Sousa Filho, Paulo C; Moreira, Roberto L; Dias, Anderson

2017-01-17

PrLuO 3 interlanthanides were prepared at temperatures ranging from 800 °C to 1600 °C using hydrothermally-derived precursors. The chemical reactions observed include the conversion and segregation of Pr(OH) 3 and LuO(OH), respectively, into PrO 2 and Lu 2 O 3 cubic oxides below 1200 °C, followed by the production of a mixture of hexagonal P6 3 /mmc and orthorhombic Pnma PrLuO 3 phases at 1400 °C. Phase-pure orthorhombic PrLuO 3 was obtained at 1600 °C, which was corroborated by Raman and micro far-infrared spectroscopic analyses. Photoluminescence, colorimetric and lifetime measurements were carried out in PrLuO 3 samples. Dominant emission verified in samples calcined at 1400 °C corresponds to the hypersensitive 3 P 0 → 3 F 2 transition with a color purity of 97% (decay times of 12 μs and 3 μs), while emissions for the phase-pure samples correspond to the 3 P 0 → 3 H 6 and 3 P 0 → 3 H 5 transitions with a color purity of 94% (a single luminescence lifetime of 12 μs). The optical properties of PrLuO 3 interlanthanides thereby suggest that they can be used as luminescent materials in both structural arrangements.

Core-shell-shell heterostructures of α-NaLuF4:Yb/Er@NaLuF4:Yb@MF2 (M = Ca, Sr, Ba) with remarkably enhanced upconversion luminescence.

PubMed

Su, Yue; Liu, Xiuling; Lei, Pengpeng; Xu, Xia; Dong, Lile; Guo, Xianmin; Yan, Xingxu; Wang, Peng; Song, Shuyan; Feng, Jing; Zhang, Hongjie

2016-07-05

Core-shell-shell heterostructures of α-NaLuF4:Yb/Er@NaLuF4:Yb@MF2 (M = Ca, Sr, Ba) have been successfully fabricated via the thermal decomposition method. Upconversion nanoparticles (UCNPs) were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), upconversion luminescence (UCL) spectroscopy, etc. Under 980 nm excitation, the emission intensities of the UCNPs are remarkably enhanced after coating the MF2 (M = Ca, Sr, and Ba) shell. Among these samples, CaF2 coated UCNPs show the strongest overall emission, while BaF2 coated UCNPs exhibit the longest lifetime. These results demonstrate that alkaline earth metal fluorides are ideal materials to improve the UCL properties. Meanwhile, although the lattice mismatch between the ternary NaREF4 core and the binary MF2 (M = Sr and Ba) shell is relatively large, the successfully synthesized NaLuF4:Yb/Er@NaLuF4:Yb@MF2 indicates a new outlook on the fabrication of heterostructural core-shell UCNPs.

Luminescent and scintillation properties of Lu3Al5O12:Sc single crystal and single crystalline films

NASA Astrophysics Data System (ADS)

Zorenko, Y.; Gorbenko, V.; Voznyak, T.; Savchyn, V.; Nizhankovskiy, S.; Dan'ko, A.; Puzikov, V.; Laguta, V.; Mares, J. A.; Nikl, M.; Nejezchleb, K.; Batentschuk, M.; Winnacker, A.

2012-10-01

The work is dedicated to growth by the liquid phase epitaxy method and study of the luminescence and scintillation properties of Sc3+ doped single crystalline films (SCF) of Lu3Al5O12 (LuAG) garnet. The scintillation properties of SCF are compared with single crystal (SC) analogues grown by the Horizontal Direct Crystallization and Czochralski methods. We consider the dependence of intensity of the Sc3+ emission in LuAG host on the activator concentration and influence of flux contamination on the light yield (LY) of the Sc3+ luminescence in LuAG:Sc SCF with respect to their SC counterparts and the reference YAP:Ce scintillator. From the NMR investigations of LuAG:Sc SCF we confirm the substitution by Sc3+ ions both the octahedral and dodecahedral positions of LuAG host and formation of the ScAl and ScLu related emission centers, respectively. We also show that the luminescence spectrum in the UV range and decay kinetics of LuAG:Sc SCF can be effectively tuned by changing the scandium content.

Water-stable NaLuF4-based upconversion nanophosphors with long-term validity for multimodal lymphatic imaging.

PubMed

Zhou, Jing; Zhu, Xingjun; Chen, Min; Sun, Yun; Li, Fuyou

2012-09-01

Multimodal imaging is rapidly becoming an important tool for biomedical applications because it can compensate for the deficiencies of individual imaging modalities. Herein, multifunctional NaLuF(4)-based upconversion nanoparticles (Lu-UCNPs) were synthesized though a facile one-step microemulsion method under ambient condition. The doping of lanthanide ions (Gd(3+), Yb(3+) and Er(3+)/Tm(3+)) endows the Lu-UCNPs with high T(1)-enhancement, bright upconversion luminescence (UCL) emissions, and excellent X-ray absorption coefficient. Moreover, the as-prepared Lu-UCNPs are stable in water for more than six months, due to the protection of sodium glutamate and diethylene triamine pentacetate acid (DTPA) coordinating ligands on the surface. Lu-UCNPs have been successfully applied to the trimodal CT/MR/UCL lymphatic imaging on the modal of small animals. It is worth noting that Lu-UCNPs could be used for imaging even after preserving for over six months. In vitro transmission electron microscope (TEM), methyl thiazolyl tetrazolium (MTT) assay and histological analysis demonstrated that Lu-UCNPs exhibited low toxicity on living systems. Therefore, Lu-UCNPs could be multimodal agents for CT/MR/UCL imaging, and the concept can be served as a platform technology for the next-generation of probes for multimodal imaging. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effective lattice stabilization of gadolinium aluminate garnet (GdAG) via Lu3+ doping and development of highly efficient (Gd,Lu)AG:Eu3+ red phosphors

PubMed Central

Li, Jinkai; Li, Ji-Guang; Zhang, Zhongjie; Wu, Xiaoli; Liu, Shaohong; Li, Xiaodong; Sun, Xudong; Sakka, Yoshio

2012-01-01

The metastable garnet lattice of Gd3Al5O12 is stabilized by doping with smaller Lu3+, which then allows an effective incorporation of larger Eu3+ activators. The [(Gd1−xLux)1−yEuy]3Al5O12 (x = 0.1–0.5, y = 0.01–0.09) garnet solid solutions, calcined from their precursors synthesized via carbonate coprecipitation, exhibit strong luminescence at 591 nm (the 5D0 → 7F1 magnetic dipole transition of Eu3+) upon UV excitation into the charge transfer band (CTB) at ∼239 nm, with CIE chromaticity coordinates of x = 0.620 and y = 0.380 (orange-red). The quenching concentration of Eu3+ was estimated at ∼5 at.% (y = 0.05), and the quenching was attributed to exchange interactions. Partial replacement of Gd3+ with Lu3+ up to 50 at.% (x = 0.5) while keeping Eu3+ at the optimal content of 5 at.% does not significantly alter the peak positions of the CTB and 5D0 → 7F1 emission bands but slightly weakens both bands owing to the higher electronegativity of Lu3+. The effects of processing temperature (1000–1500 °C) and Lu/Eu contents on the intensity, quantum efficiency, lifetime and asymmetry factor of luminescence were thoroughly investigated. The [(Gd0.7Lu0.3)0.95Eu0.05]3Al5O12 phosphor processed at 1500 °C exhibits a high internal quantum efficiency of ∼83.2% under 239 nm excitation, which, in combination with the high theoretical density, favors its use as a new type of photoluminescent and scintillation material. PMID:27877495

Tracer level radiochemistry to clinical dose preparation of (177)Lu-labeled cyclic RGD peptide dimer.

PubMed

Chakraborty, Sudipta; Sarma, H D; Vimalnath, K V; Pillai, M R A

2013-10-01

Integrin αvβ3 plays a significant role in angiogenesis during tumor growth and metastasis, and is a receptor for the extracellular matrix proteins with the exposed arginine(R)-glycine(G)-aspartic acid(D) tripeptide sequence. The over-expression of integrin αvβ3 during tumor growth and metastasis presents an interesting molecular target for both early detection and treatment of rapidly growing solid tumors. Considering the advantages of (177)Lu for targeted radiotherapy and enhanced tumor targeting capability of cyclic RGD peptide dimer, an attempt has been made to optimize the protocol for the preparation of clinical dose of (177)Lu labeled DOTA-E[c(RGDfK)]2 (E=Glutamic acid, f=phenyl alanine, K=lysine) as a potential agent for targeted tumor therapy. (177)Lu was produced by thermal neutron bombardment on enriched Lu2O3 (82% in (176)Lu) target at a flux of 1 × 10(14) n/cm(2).s for 21 d. Therapeutic dose of (177)Lu-DOTA-E[c(RGDfK)]2 (7.4GBq) was prepared by adding the aqueous solution of the ligand and (177)LuCl3 to 0.1M NH4OAC buffer containing gentisic acid and incubating the reaction mixture at 90°C for 30 min. The yield and radiochemical purity of the complex was determined by HPLC technique. Parameters, such as, ligand-to-metal ratio, pH of the reaction mixture, incubation time and temperature were varied using tracer quantity of (177)Lu (37 MBq) in order to arrive at the optimized protocol for the preparation of clinical dose. Biological behavior of the radiotracer prepared was studied in C57/BL6 mice bearing melanoma tumors. (177)Lu was produced with a specific activity of 950 ± 50 GBq/mg (25.7 ± 1.4 Ci/mg) and radionuclidic purity of 99.98%. A careful optimization of several parameters showed that (177)Lu-DOTA-E[c(RGDfK)]2 could be prepared with adequately high radiochemical purity using a ligand-to-metal ratio ~2. Based on these studies therapeutic dose of the agent with 7.4 GBq of (177)Lu was formulated in ~63 GBq/μM specific activity with high

STS-106 Mission Specialist Lu suits up before launch

NASA Technical Reports Server (NTRS)

2000-01-01

STS-106 Mission Specialist Edward T. Lu smiles as he gets suited up in the Operations and Checkout Building before launch. This is Lu'''s second space flight. Space Shuttle Atlantis is set to lift off 8:45 a.m. EDT on the fourth flight to the International Space Station. During the 11-day mission, the seven-member crew will perform support tasks on orbit, transfer supplies and prepare the living quarters in the newly arrived Zvezda Service Module. The first long-duration crew, dubbed '''Expedition One,''' is due to arrive at the Station in late fall.

Lu plays with a droplet of liquid

NASA Image and Video Library

2003-10-25

ISS007-E-17985 (2003) --- Astronaut Edward T. Lu, Expedition 7 NASA ISS science officer and flight engineer, watches a water bubble float between him and the camera, showing his image refracted, on the International Space Station (ISS).

Lu-Hf isotope systematics of fossil biogenic apatite and their effects on geochronology

NASA Astrophysics Data System (ADS)

Herwartz, Daniel; Münker, Carsten; Tütken, Thomas; Hoffmann, J. Elis; Wittke, Andreas; Barbier, Bruno

2013-01-01

Reliable methods for direct dating of biogenic apatite from pre-Pleistocene fossils are currently not available, and recent attempts using the Lu-Hf decay system yielded highly inaccurate ages for both bones and teeth. The geological processes accounting for this poor accuracy of Lu-Hf chronometry are not yet understood. Here we explore Lu-Hf systematics in fossil bones and teeth in detail, by applying five different sample digestion techniques that are tested on bones and composites of bone and sediment. Our current dataset implies that dissolution methods only slightly affect the resulting Lu-Hf ages, while clear differences between the individual digestion techniques became apparent for element concentrations. By analysing the insoluble leftovers from incomplete sample dissolution, four main reservoirs of Hf in fossil bones were identified: (1) a radiogenic end-member associated with apatite; (2) an unradiogenic end-member represented by the authigenic minerals or the embedding sediment; (3) a highly unradiogenic end-member that can be attributed to detrital zircon; and (4) a moderately soluble phase (probably a Zr(Hf)-phosphate) that yielded very low Lu/Hf but a highly radiogenic Hf isotope composition at the same time. This Zr(Hf)-phase must have been precipitated within the fossil bone sample at a late stage of burial history, thereby incorporating radiogenic 176Hf released from apatite surfaces over geological timescales. A second focus of our study is the effect of different sediment matrices and of crystal size on the preservation of pristine Lu-Hf isotope compositions in bioapatite. Because near-depositional Lu-Hf ages of phosphate fossils have previously been reported for the London Clay (England) and a calcareous marl from Tendaguru (Tanzania), we herein investigate specimens fossilised in carbonate matrices (calcareous marl from Oker, Germany; carbonate concretions from the Santana Formation, Brazil; carbonate from the Eifel, Germany) and argillaceous

Preparation and evaluation of Lu-177 phytate Complex for Radiosynovectomy

PubMed Central

Yousefnia, Hassan; Jalilian, Amir Reza; Zolghadri, Samaneh

2014-01-01

Lu-177 of 2.6-3 GBq/mg specific activity was obtained by irradiation of natural Lu2O3 sample with thermal neutron flux of 4 × 1013 n/cm/s. The product was converted into chloride form which was further used for labeling of Lu-177 phytate complex successfully with high radiochemical purity (>99.9%, instant thin layer chromatography, MeOH: H2O: Acetic acid, 4:4:2, as mobile phase). The complex stability and viscosity were checked in the final solution up to 7 days. The prepared complex solution (100 μCi/100 μl) was injected intra-articularly to the male rat knee joint. Leakage of radioactivity from the injection site and its distribution in organs were investigated up to 7 days. Approximately, all injected dose has remained in injection site 7 days after injection. The complex was proved to be a feasible agent for cavital radiotherapy in oncology and rheumatology. PMID:25191108

[177Lu]pentixather: Comprehensive Preclinical Characterization of a First CXCR4-directed Endoradiotherapeutic Agent

PubMed Central

Schottelius, Margret; Osl, Theresa; Poschenrieder, Andreas; Hoffmann, Frauke; Beykan, Seval; Hänscheid, Heribert; Schirbel, Andreas; Buck, Andreas K.; Kropf, Saskia; Schwaiger, Markus; Keller, Ulrich; Lassmann, Michael; Wester, Hans-Jürgen

2017-01-01

Purpose: Based on the clinical relevance of the chemokine receptor 4 (CXCR4) as a molecular target in cancer and on the success of [68Ga]pentixafor as an imaging probe for high-contrast visualization of CXCR4-expression, the spectrum of clinical CXCR4-targeting was expanded towards peptide receptor radionuclide therapy (PRRT) by the development of [177Lu]pentixather. Experimental design: CXCR4 affinity, binding specificity, hCXCR4 selectivity and internalization efficiency of [177Lu]pentixather were evaluated using different human and murine cancer cell lines. Biodistribution studies (1, 6, 48, 96h and 7d p.i.) and in vivo metabolite analyses were performed using Daudi-lymphoma bearing SCID mice. Extrapolated organ doses were cross-validated with human dosimetry (pre-therapeutic and during [177Lu]pentixather PRRT) in a patient with multiple myeloma (MM). Results: [177Lu]pentixather binds with high affinity, specificity and selectivity to hCXCR4 and shows excellent in vivo stability. Consequently, and supported by >96% plasma protein binding and a logP=-1.76, delaying whole-body clearance of [177Lu]pentixather, tumor accumulation was high and persistent, both in the Daudi model and the MM patient. Tumor/background ratios (7d p.i.) in mice were 499±202, 33±7, 4.0±0.8 and 116±22 for blood, intestine, kidney and muscle, respectively. In the patient, high tumor/kidney and tumor/liver dose ratios of 3.1 and 6.4 were observed during [177Lu]pentixather PRRT (7.8 GBq), with the kidneys being the dose-limiting organs. Conclusions: [177Lu]pentixather shows excellent in vivo CXCR4-targeting characteristics and a suitable pharmacokinetic profile, leading to high tumor uptake and retention and thus high radiation doses to tumor tissue during PRRT, suggesting high clinical potential of this [68Ga]pentixafor/[177Lu]pentixather based CXCR4-targeted theranostic concept. PMID:28744319

Peculiarities of thermoelectric half-Heusler phase formation in Gd-Ni-Sb and Lu-Ni-Sb ternary systems

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

Romaka, V.V., E-mail: romakav@lp.edu.ua; Romaka, L.; Horyn, A.

The phase equilibria in the Gd–Ni–Sb and Lu-Ni-Sb ternary systems were studied at 873 K by X-ray and metallographic analyses in the whole concentration range. The interaction of the elements in the Gd–Ni–Sb system results the formation of five ternary compounds at investigated temperature: Gd{sub 5}Ni{sub 2}Sb (Mo{sub 5}SiB{sub 2}-type), Gd{sub 5}NiSb{sub 2} (Yb{sub 5}Sb{sub 3}-type), GdNiSb (MgAgAs-type), Gd{sub 3}Ni{sub 6}Sb{sub 5} (Y{sub 3}Ni{sub 6}Sb{sub 5}-type), and GdNi{sub 0.72}Sb{sub 2} (HfCuSi{sub 2}-type). At investigated temperature the Lu-Ni-Sb system is characterized by formation of the LuNiSb (MgAgAs-type), Lu{sub 5}Ni{sub 2}Sb (Mo{sub 5}SiB{sub 2}-type), and Lu{sub 5}Ni{sub 0.56}Sb{sub 2.44} (Yb{sub 5}Sb{sub 3}-type)more » compounds. The disordering in the crystal structure of half-Heusler GdNiSb and LuNiSb was revealed by EPMA and studied by means of Rietveld refinement and DFT modeling. The performed electronic structure calculations are in good agreement with electrical transport property studies. - Graphical abstract: Crystal structure model and electron localization function of Lu{sub 5}Ni{sub 2}Sb. Display Omitted - Highlights: • Gd-Ni-Sb and Lu-Ni-Sb phase diagrams were constructed at 873 K. • GdNiSb and LuNiSb are characterized by disordered crystal structure. • Crystal structure optimization with DFT calculations confirmed crystal structure disorder in GdNiSb and LuNiSb.« less

An electro-amalgamation approach to isolate no-carrier-added 177Lu from neutron irradiated Yb for biomedical applications.

PubMed

Chakravarty, Rubel; Das, Tapas; Dash, Ashutosh; Venkatesh, Meera

2010-10-01

A novel two-step separation process for the production of no-carrier-added (NCA) (177)Lu from neutron irradiated Yb target through an electrochemical pathway employing mercury-pool cathode has been developed. A two-cycle electrolysis procedure was adopted for separation of (177)Lu from (177)Lu/Yb mixture in lithium citrate medium. The influence of different experimental parameters on the separation process was investigated and optimized for the quantitative deposition of Yb in presence of (177)Lu. The first electrolysis was performed for 50 min in the (177)Lu/Yb feed solution at pH 6 applying a potential of 8 V using platinum electrode as anode and mercury as the cathode. The second electrolysis was performed under the same conditions using fresh electrodes. The radionuclidic and chemical purity of (177)Lu was determined by using gamma ray spectrometry and atomic absorption spectrometry. The suitability of (177)Lu for biomedical applications was ascertained by labeling 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid D-Phe(1)-Tyr(3)-octreotate(DOTA-TATE) with (177)Lu. This process could provide NCA (177)Lu with >99.99% radionuclidic purity and an overall separation yield of ∼99% was achieved within 3-4 h. The Hg content in the product was determined to be <1 ppm. Radiolabeling yield of >98% was obtained with DOTA-TATE under the optimized reaction conditions. An efficient strategy for the separation of NCA (177)Lu, suitable for biomedical applications, has been developed. Copyright © 2010 Elsevier Inc. All rights reserved.

Automatic Blocking Of QR and LU Factorizations for Locality

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

Yi, Q; Kennedy, K; You, H

2004-03-26

QR and LU factorizations for dense matrices are important linear algebra computations that are widely used in scientific applications. To efficiently perform these computations on modern computers, the factorization algorithms need to be blocked when operating on large matrices to effectively exploit the deep cache hierarchy prevalent in today's computer memory systems. Because both QR (based on Householder transformations) and LU factorization algorithms contain complex loop structures, few compilers can fully automate the blocking of these algorithms. Though linear algebra libraries such as LAPACK provides manually blocked implementations of these algorithms, by automatically generating blocked versions of the computations, moremore » benefit can be gained such as automatic adaptation of different blocking strategies. This paper demonstrates how to apply an aggressive loop transformation technique, dependence hoisting, to produce efficient blockings for both QR and LU with partial pivoting. We present different blocking strategies that can be generated by our optimizer and compare the performance of auto-blocked versions with manually tuned versions in LAPACK, both using reference BLAS, ATLAS BLAS and native BLAS specially tuned for the underlying machine architectures.« less

High-energy, ceramic-disk Yb:LuAG laser amplifier.

PubMed

Siebold, M; Loeser, M; Roeser, F; Seltmann, M; Harzendorf, G; Tsybin, I; Linke, S; Banerjee, S; Mason, P D; Phillips, P J; Ertel, K; Collier, J C; Schramm, U

2012-09-24

We report the first short-pulse amplification results to several hundred millijoule energies in ceramic Yb:LuAG. We have demonstrated ns-pulse output from a diode-pumped Yb:LuAG amplifier at a maximum energy of 580 mJ and a peak optical-to-optical efficiency of 28% at 550 mJ. In cavity dumped operation of a nanosecond oscillator we obtained 1 mJ at up to 100 Hz repetition rate. A gain bandwidth of 5.4 nm was achieved at room temperature by measuring the small-signal single-pass gain. Furthermore, we compared our results with Yb:YAG within the same amplifier system.

Magnetic and magnetotransport properties of the orthorhombic perovskites (Lu,Ca)MnO3

NASA Astrophysics Data System (ADS)

Imamura, N.; Karppinen, M.; Motohashi, T.; Yamauchi, H.

2008-01-01

Here we extend the research of the (R,Ca)MnO3 perovskites to the smallest- R end member (Lu,Ca)MnO3 . Magnetic and magnetotransport properties of the (Lu1-xCax)MnO3 system are systematically investigated in regard to carrier doping. It is found that hole doping into the antiferromagnetic x=0.0 phase, LuMnO3 , causes a spin-glass-like magnetic competition in the wide doping range of 0.1≤x≤0.6 , whereas electron doping into the antiferromagnetic x=1.0 phase, CaMnO3 , induces a large magnetoresistance effect for 0.8≤x≤0.95 .

Metastatic Bone Pain Palliation using (177)Lu-Ethylenediaminetetramethylene Phosphonic Acid.

PubMed

Alavi, Mehrosadat; Omidvari, Shapour; Mehdizadeh, Alireza; Jalilian, Amir R; Bahrami-Samani, Ali

2015-01-01

(177)Lu-ethylenediaminetetramethylene phosphonic acid (EDTMP) is presently suggested as an excellent bone seeking radionuclide for developing metastatic bone pain (MBP) palliation agent owing to its suitable nuclear decay characteristics. To find the exact dosage and its efficiency, this clinical study was performed on the human being, using (177)Lu-EDTMP for MBP palliation. (177)Lu-EDTMP was prepared by Iran, atomic energy organization. Thirty consecutive patients with determined tumors, incontrollable MBP, and positive bone scan at 4 weeks before the beginning of the study participated in this study in the nuclear medicine ward. (177)Lu-EDTMP in the form of sterile slow IV injection was administered with a dose of 29.6 MBq/kg. Short form of brief pain inventory questionnaire was used to evaluate the efficiency of the intervention. Questionnaires were filled out by an expert nuclear physician every 2 weeks while the cell blood count was also checked every 2 weeks up to 12 weeks for evaluation of bone marrow suppression and hematological toxicity. Furthermore, whole body scan was done at days 1, 3, and 7. Twenty-five patients showed a significant pain relief since 2 weeks after the injection, and continued until the end of the follow up period (12 weeks). There were no significant early complications such as bone marrow suppression, hematological toxicity, and no systemic adverse effects. No complication was observed in renal function. Twenty one patients showed flare phenomenon that was started after the 12.2 ± 1.78 h lasting for 38.4 ± 23.08. Sixteen patients (53%) were completely treated; nine patients (30%) showed a partial response, and five patients (17%) had no response to treatment. Total response to treatment was achieved in 25 patients (83%). At the end of the evaluation, no bone marrow suppression or hematologic toxicity was observed. (177)Lu-EDTMP has shown suitable physical and biological properties with good results in long term bone pain relief for

Metastatic Bone Pain Palliation using 177Lu-Ethylenediaminetetramethylene Phosphonic Acid

PubMed Central

Alavi, Mehrosadat; Omidvari, Shapour; Mehdizadeh, Alireza; Jalilian, Amir R.; Bahrami-Samani, Ali

2015-01-01

177Lu-ethylenediaminetetramethylene phosphonic acid (EDTMP) is presently suggested as an excellent bone seeking radionuclide for developing metastatic bone pain (MBP) palliation agent owing to its suitable nuclear decay characteristics. To find the exact dosage and its efficiency, this clinical study was performed on the human being, using 177Lu-EDTMP for MBP palliation. 177Lu-EDTMP was prepared by Iran, atomic energy organization. Thirty consecutive patients with determined tumors, incontrollable MBP, and positive bone scan at 4 weeks before the beginning of the study participated in this study in the nuclear medicine ward. 177Lu-EDTMP in the form of sterile slow IV injection was administered with a dose of 29.6 MBq/kg. Short form of brief pain inventory questionnaire was used to evaluate the efficiency of the intervention. Questionnaires were filled out by an expert nuclear physician every 2 weeks while the cell blood count was also checked every 2 weeks up to 12 weeks for evaluation of bone marrow suppression and hematological toxicity. Furthermore, whole body scan was done at days 1, 3, and 7. Twenty-five patients showed a significant pain relief since 2 weeks after the injection, and continued until the end of the follow up period (12 weeks). There were no significant early complications such as bone marrow suppression, hematological toxicity, and no systemic adverse effects. No complication was observed in renal function. Twenty one patients showed flare phenomenon that was started after the 12.2 ± 1.78 h lasting for 38.4 ± 23.08. Sixteen patients (53%) were completely treated; nine patients (30%) showed a partial response, and five patients (17%) had no response to treatment. Total response to treatment was achieved in 25 patients (83%). At the end of the evaluation, no bone marrow suppression or hematologic toxicity was observed. 177Lu-EDTMP has shown suitable physical and biological properties with good results in long term bone pain relief for patients

Half-life measurement of the medical radioisotope 177Lu produced from the 176Yb(n,γ) reaction

NASA Astrophysics Data System (ADS)

Ferreira, K. M.; Collins, S. M.; Fenwick, A. J.

2017-09-01

177Lu is a medium energy beta-emitter commonly used in Nuclear Medicine for radiotherapeutic applications. In this work, the half-life of 177Lu has been measured using a re-entrant ionisation chamber over a period of 82 days (approximately 12 half-lives). Unlike the majority of previous studies, the material used in this work was produced via the 176Yb(n,γ)177Yb reaction followed by the β-decay to 177Lu, producing insignificant quantities of 177mLu. This has resulted in the most precise half-life measurement of 177Lu to date. A half-life of 6.6430 (11) days has been determined. This value is in statistical agreement with the currently recommended half-life of 6.6463 (15) days (z-score = 1.8).

Erythrocytes from patients with myeloproliferative neoplasms and splanchnic venous thrombosis show greater expression of Lu/BCAM.

PubMed

Novitzky-Basso, I; Spring, F; Anstee, D; Tripathi, D; Chen, F

2018-05-13

Lutheran/BCAM protein (Lu) on the surface of erythrocytes is key for their adhesion to the endothelium, and erythrocytes from individuals with JAK2V617F-mutated myeloproliferative neoplasms (MPN) have increased endothelial adhesion. Splanchnic vein thrombosis (SVT) is a devastating thrombotic complication of MPN, and frequently, the only diagnostic feature is the JAK2V617F mutation. We sought to examine whether erythrocytes from patients with JAK2V617F mutated SVT (MPN-SVT) exhibited increased Lu expression, thereby supporting a mechanistic contribution to the development of thrombosis. We report the validation of a novel flow cytometry assay for Lu expression on erythrocytes. We examined the expression of Lu on erythrocytes from a cohort of MPN patients with and without SVT, and healthy controls. Samples were obtained from 20 normal individuals, 22 with MPN (both JAK2V617F-mutated and wild-type) and 8 with JAK2V617F-mutated MPN-SVT. Lu expression by erythrocytes from patients with MPN and MPN-SVT is significantly increased compared to erythrocytes from healthy individuals (P < .05), but there was no significant difference between patients with MPN-SVT and MPN. Patients with MPN have increased expression of the red cell Lu/BCAM adhesion molecule. Further work is required to determine the role of the increased Lu/BCAM adhesion to the endothelium in the development of thrombosis in MPN of all genotypes. © 2018 John Wiley & Sons Ltd.

Promise and Pitfalls of Lu/Hf-Sm/Nd Garnet Geochronology

NASA Astrophysics Data System (ADS)

King, R. L.; Vervoort, J. D.; Kohn, M. J.; Zirakparvar, N. A.; Hart, G. L.; Corrie, S. L.; Cheng, H.

2007-12-01

Our ability to routinely measure Lu-Hf and Sm-Nd isotopes in garnet allows broad new applications in geochronology, petrology, and tectonics. However, applications of these data can be limited by challenges in interpreting the petrologic record and preparing garnets for analysis. Here, we examine petrologic and chemical pitfalls encountered in garnet geochronology. Petrologic factors influencing trace element compositions in garnet include reactions that modify REE availability and partitioning (1,2), kinetically limited transfer of REEs to garnet (3), and bulk compositional heterogeneities (4). Interpreting the effects of these processes on Sm/Nd and Lu/Hf ages requires characterizing REE zonation prior to isotope analysis and age interpretation. Because garnet fractions are traditionally picked from crushed samples without regard to intracrystalline origins or chemistries, isochrons will represent mixtures derived to varying degrees from all periods of garnet growth. While measured zoning might generally indicate what garnet portion dominates the Lu/Hf or Sm/Nd budget, traditional mineral separation will rarely realize the chronologic potential afforded by high precision Hf and Nd isotope measurements. The potential use of alternative techniques, such as microsampling, necessitates selective digestion and/or leaching to eliminate inclusions within garnet. For Sm/Nd geochronology, H2SO4 leaching removes LREE-rich phosphates (e.g. apatite), but not silicates (e.g. epidote), precluding Sm-Nd dating of some rocks. For Lu/Hf geochronology, ubiquitous zircon microinclusions (c. 1 μm) can significantly disrupt age determinations. Microinclusions cannot be detected optically or separated physically, requiring selective chemical digestion. If complete digestion methods, such as bomb digestion, are used for garnet fractions, then "common Hf" from zircon will be contained in final solutions. These mixed analyses are of dubious utility and will fall into one of two

Radiation Nanomedicine for EGFR-Positive Breast Cancer: Panitumumab-Modified Gold Nanoparticles Complexed to the β-Particle-Emitter, (177)Lu.

PubMed

Yook, Simmyung; Cai, Zhongli; Lu, Yijie; Winnik, Mitchell A; Pignol, Jean-Philippe; Reilly, Raymond M

2015-11-02

Our objective was to construct a novel radiation nanomedicine for treatment of breast cancer (BC) expressing epidermal growth factor receptors (EGFR), particularly triple-negative tumors (TNBC). Gold nanoparticles (AuNP; 30 nm) were modified with polyethylene glycol (PEG) chains (4 kDa) derivatized with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelators for complexing the β-emitter, (177)Lu and with PEG chains (5 kDa) linked to panitumumab for targeting BC cells expressing EGFR. The AuNP were further coated with PEG chains (2 kDa) to stabilize the particles to aggregation. The binding and internalization of EGFR-targeted AuNP ((177)Lu-T-AuNP) into BC cells was studied and compared to nontargeted (177)Lu-NT-AuNP. The cytotoxicity of (177)Lu-T-AuNP and (177)Lu-NT-AuNP was measured in clonogenic assays using BC cells with widely different EGFR densities: MDA-MB-468 (10(6) receptors/cell), MDA-MB-231 (10(5) receptors/cell), and MCF-7 cells (10(4) receptors/cell). Radiation absorbed doses to the cell nucleus of MDA-MB-468 cells were estimated based on subcellular distribution. Darkfield and fluorescence microscopy as well as radioligand binding assays revealed that (177)Lu-T-AuNP were specifically bound by BC cells dependent on their EGFR density whereas the binding and internalization of (177)Lu-NT-AuNP was significantly lower. The affinity of binding of (177)Lu-T-AuNP to MDA-MB-468 cells was reduced by 2-fold compared to (123)I-labeled panitumumab (KD = 1.3 ± 0.2 nM vs 0.7 ± 0.4 nM, respectively). The cytotoxicity of (177)Lu-T-AuNP was dependent on the amount of radioactivity incubated with BC cells, their EGFR density and the radiosensitivity of the cells. The clonogenic survival (CS) of MDA-MB-468 cells overexpressing EGFR was reduced to <0.001% at the highest amount of (177)Lu-T-AuNP tested (4.5 MBq; 6 × 10(11) AuNP per 2.5 × 10(4)-1.2 × 10(5) cells). (177)Lu-T-AuNP were less effective for killing MDA-MB-231 cells or MCF-7 cells with

Somatostatin-based radiopeptide therapy with [177Lu-DOTA]-TOC versus [90Y-DOTA]-TOC in neuroendocrine tumours.

PubMed

Romer, A; Seiler, D; Marincek, N; Brunner, P; Koller, M T; Ng, Q K T; Maecke, H R; Müller-Brand, J; Rochlitz, C; Briel, M; Schindler, C; Walter, M A

2014-02-01

Somatostatin-based radiopeptide treatment is generally performed using the β-emitting radionuclides (90)Y or (177)Lu. The present study aimed at comparing benefits and harms of both therapeutic approaches. In a comparative cohort study, patients with advanced neuroendocrine tumours underwent repeated cycles of [(90)Y-DOTA]-TOC or [(177)Lu-DOTA]-TOC until progression of disease or permanent adverse events. Multivariable Cox regression and competing risks regression were employed to examine predictors of survival and adverse events for both treatment groups. Overall, 910 patients underwent 1,804 cycles of [(90)Y-DOTA]-TOC and 141 patients underwent 259 cycles of [(177)Lu-DOTA]-TOC. The median survival after [(177)Lu-DOTA]-TOC and after [(90)Y-DOTA]-TOC was comparable (45.5 months versus 35.9 months, hazard ratio 0.91, 95% confidence interval 0.63-1.30, p = 0.49). Subgroup analyses revealed a significantly longer survival for [(177)Lu-DOTA]-TOC over [(90)Y-DOTA]-TOC in patients with low tumour uptake, solitary lesions and extra-hepatic lesions. The rate of severe transient haematotoxicities was lower after [(177)Lu-DOTA]-TOC treatment (1.4 vs 10.1%, p = 0.001), while the rate of severe permanent renal toxicities was similar in both treatment groups (9.2 vs 7.8%, p = 0.32). The present results revealed no difference in median overall survival after [(177)Lu-DOTA]-TOC and [(90)Y-DOTA]-TOC. Furthermore, [(177)Lu-DOTA]-TOC was less haematotoxic than [(90)Y-DOTA]-TOC.

MS Lu installs the TVIS equipment in Zvezda during STS-106

NASA Image and Video Library

2000-09-16

STS106-390-024 (8-20 September 2000) --- Astronaut Edward T. Lu, mission specialist, handles part of the treadmill device on the Service Module for the International Space Station. The crew left this and a large number of other items of hardware and supplies for future inhabitants of the station. Lu and four other astronauts, along with two cosmonauts, are wrapping up a 4.9 million-mile mission in which more than three tons of equipment were delivered to the International outpost.

Lu{sub 2}O{sub 3}:Eu{sup 3+} glass ceramic films: Synthesis, structural and spectroscopic studies

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

Carrera Jota, M.L.; García Murillo, A., E-mail: angarciam@ipn.mx; Carrillo Romo, F.

2014-03-01

Graphical abstract: - Highlights: • Lu{sub 2}O{sub 3}:Eu{sup 3+}@SiO{sub 2} films were synthesized by sol–gel and by dip-coating technique. • Effects of incorporating PVP on structural properties were studied. • Effects of incorporating silica (SiO{sub 2}) luminescence characteristics were analyzed. • X-ray diffraction results showed that Lu{sub 2}O{sub 3}:Eu{sup 3+}@SiO{sub 2} crystallizes at 700 °C. • The 611 nm emission for the Lu:Si = 8:1 system presented an improvement. - Abstract: For the first time, transparent and crack free europium-doped lutetia silica sol–gel films were synthesized using the dip-coating technique on silica quartz substrates. In this study, we examined themore » effects of incorporating polyvinylpyrrolidone (PVP) and silica (SiO{sub 2}) into different precursor solutions for different Lu–Si molar ratios: 4:1, 6:1, 8:1 and 10:1. Different systems, such as Lu{sub 2}O{sub 3}:Eu{sup 3+}@SiO{sub 2} (using the above Lu:Si molar ratios), were synthesized by sol–gel and by dip-coating technique, employing acetylacetonate lutetium and tetraethylorthosilicate as Lu and Si precursors, in order to produce Lu{sub 2}O{sub 3}:Eu{sup 3+} (5 mol%)@SiO{sub 2} glass–ceramic films. The film microstructure was studied by microRaman spectroscopy (MRS) and X-ray diffraction (XRD) for different Lu:Si molar ratios on films annealed at 700 °C. X-ray diffraction results showed that the lutetium oxide cubic phase crystallizes in the silica matrix at 700 °C, and the crystallite size of Lu{sub 2}O{sub 3}:Eu{sup 3+}@SiO{sub 2} films varies from 5 nm to 17 nm according to the respective Lu:Si molar ratios. Opto-geometrical parameters determined by m-lines spectroscopy using a 632.5 nm He–Ne laser showed that the Eu{sup 3+} doped films heat-treated at 700 °C presented a thickness and density of 1.7 μm (8.8 g cm{sup −3}), 970 nm (9.2 g cm{sup −3}), 1 μm (9.3 g cm{sup −3}) and 1.3 μm (9.25 g cm{sup −3}) for the Lu:Si = 4:1, 6:1, 8

A Hybrid Approach Using Case-Based Reasoning and Rule-Based Reasoning to Support Cancer Diagnosis: A Pilot Study.

PubMed

Saraiva, Renata M; Bezerra, João; Perkusich, Mirko; Almeida, Hyggo; Siebra, Clauirton

2015-01-01

Recently there has been an increasing interest in applying information technology to support the diagnosis of diseases such as cancer. In this paper, we present a hybrid approach using case-based reasoning (CBR) and rule-based reasoning (RBR) to support cancer diagnosis. We used symptoms, signs, and personal information from patients as inputs to our model. To form specialized diagnoses, we used rules to define the input factors' importance according to the patient's characteristics. The model's output presents the probability of the patient having a type of cancer. To carry out this research, we had the approval of the ethics committee at Napoleão Laureano Hospital, in João Pessoa, Brazil. To define our model's cases, we collected real patient data at Napoleão Laureano Hospital. To define our model's rules and weights, we researched specialized literature and interviewed health professional. To validate our model, we used K-fold cross validation with the data collected at Napoleão Laureano Hospital. The results showed that our approach is an effective CBR system to diagnose cancer.

Overall survival and response pattern of castration-resistant metastatic prostate cancer to multiple cycles of radioligand therapy using [177Lu]Lu-PSMA-617.

PubMed

Ahmadzadehfar, Hojjat; Wegen, Simone; Yordanova, Anna; Fimmers, Rolf; Kürpig, Stefan; Eppard, Elisabeth; Wei, Xiao; Schlenkhoff, Carl; Hauser, Stefan; Essler, Markus

2017-08-01

Up to 30% of patients with castration-resistant prostate cancer (CRPC) do not show any response to the first cycle of radioligand therapy (RLT) with [ 177 Lu]Lu-PSMA-617 (Lu-PSMA). We evaluated patient response to the second and third cycles of RLT in patients that underwent at least three cycles. The second aim of this study was to calculate the median overall survival (OS) of responders and non-responders after the first cycle and after all three cycles of RLT. CRPC patients were treated with Lu-PSMA, with a median interval of 8 weeks between each cycle. The tumour marker prostate-specific antigen (PSA) was used as the marker for response evaluation. Fifty-two patients underwent a total of 190 cycles of RLT (3-6 cycles per patient). Of these, 80.8% showed a decline in PSA 2 months after the first cycle, with 44.2% showing a PSA decline of ≥50%. When compared to baseline PSA, 73.1% showed a PSA decline after the third cycle. 50% of patients that did not show any response to the first cycle also did not respond to the second and third cycles. The median OS was 60 weeks in all patients. The median OS was significantly longer for patients that showed any PSA decline after the first cycle compared to patients without PSA decline (68 vs. 33 weeks). There was a significant difference in median OS between responders and non-responders for a change in PSA after the third cycle compared to baseline PSA. Patients with a positive response to RLT, regardless of the rate of decline, had a significantly longer median OS. Of the patients that did not show any response to the first cycle, 50% responded to the second or third cycles.

The regulation of prostitution in Beyoğlu (1875-1915).

PubMed

özbek, Müge

2010-01-01

This study examines the development and nature of the regulation of prostitution in Beyoğlu during the late Ottoman Empire with special emphasis on the way the regulationist regime reinforced existing patterns of class and gender domination. The regulation of prostitution became a matter of urgency in the last decades of the nineteenth century in Istanbul, particularly in Beyoğlu, the cosmopolitan centre of the city. Through this process, the protests of the local residents of the area objecting to the proliferation of prostitution in their neighbourhoods played a crucial role in prompting the governmental authorities to tighten the regulations.

Performance Evaluation and Quantitative Accuracy of Multipinhole NanoSPECT/CT Scanner for Theranostic Lu-177 Imaging

NASA Astrophysics Data System (ADS)

Gupta, Arun; Kim, Kyeong Yun; Hwang, Donghwi; Lee, Min Sun; Lee, Dong Soo; Lee, Jae Sung

2018-06-01

SPECT plays important role in peptide receptor targeted radionuclide therapy using theranostic radionuclides such as Lu-177 for the treatment of various cancers. However, SPECT studies must be quantitatively accurate because the reliable assessment of tumor uptake and tumor-to-normal tissue ratios can only be performed using quantitatively accurate images. Hence, it is important to evaluate performance parameters and quantitative accuracy of preclinical SPECT systems for therapeutic radioisotopes before conducting pre- and post-therapy SPECT imaging or dosimetry studies. In this study, we evaluated system performance and quantitative accuracy of NanoSPECT/CT scanner for Lu-177 imaging using point source and uniform phantom studies. We measured recovery coefficient, uniformity, spatial resolution, system sensitivity and calibration factor for mouse whole body standard aperture. We also performed the experiments using Tc-99m to compare the results with that of Lu-177. We found that the recovery coefficient of more than 70% for Lu-177 at the optimum noise level when nine iterations were used. The spatial resolutions of Lu-177 with and without adding uniform background was comparable to that of Tc-99m in axial, radial and tangential directions. System sensitivity measured for Lu-177 was almost three times less than that of Tc-99m.

A comparison of SuperLU solvers on the intel MIC architecture

NASA Astrophysics Data System (ADS)

Tuncel, Mehmet; Duran, Ahmet; Celebi, M. Serdar; Akaydin, Bora; Topkaya, Figen O.

2016-10-01

In many science and engineering applications, problems may result in solving a sparse linear system AX=B. For example, SuperLU_MCDT, a linear solver, was used for the large penta-diagonal matrices for 2D problems and hepta-diagonal matrices for 3D problems, coming from the incompressible blood flow simulation (see [1]). It is important to test the status and potential improvements of state-of-the-art solvers on new technologies. In this work, sequential, multithreaded and distributed versions of SuperLU solvers (see [2]) are examined on the Intel Xeon Phi coprocessors using offload programming model at the EURORA cluster of CINECA in Italy. We consider a portfolio of test matrices containing patterned matrices from UFMM ([3]) and randomly located matrices. This architecture can benefit from high parallelism and large vectors. We find that the sequential SuperLU benefited up to 45 % performance improvement from the offload programming depending on the sparse matrix type and the size of transferred and processed data.

Scintillation properties of YAlO3 doped with Lu and Nd perovskite single crystals

NASA Astrophysics Data System (ADS)

Akatsuka, Masaki; Usui, Yuki; Nakauchi, Daisuke; Kato, Takumi; Kawano, Naoki; Okada, Go; Kawaguchi, Noriaki; Yanagida, Takayuki

2018-05-01

YAlO3 (YAP) single crystals doped with Lu and Nd were grown by the Floating Zone (FZ) method to evaluate their scintillation properties particularly emissions in the near-infrared (NIR) range. The Nd concentration was fixed to 0 or 1 mol% while the Lu concentration was varied from 0 to 30%. When X-ray was irradiated, the scintillation of Nd-doped samples was observed predominantly at 1064 nm due to 4F3/2 → 4I11/2 transition of Nd3+. In contrast, a weak emission around 700 nm appeared in the samples doped with only Lu, and the emission origin was attributed to defect centers. In the Nd3+-doped samples, the decay time was 94-157 μs due to the 4f-4f transitions of Nd3+ whereas the Lu-doped samples showed signal with the decay time of 1.45-1.54 ms. The emission origin of the latter signal was attributed to the perovskite lattice defect.

Phase stabilization in transparent Lu2O3:Eu ceramics by lattice expansion

NASA Astrophysics Data System (ADS)

Seeley, Z. M.; Dai, Z. R.; Kuntz, J. D.; Cherepy, N. J.; Payne, S. A.

2012-11-01

Gadolinium lutetium oxide transparent ceramics doped with europium (Gd,Lu)2O3:Eu were fabricated via vacuum sintering and hot isostatic pressing (HIP). Nano-scale starting powder with the composition GdxLu1.9-xEu0.1O3 (x = 0, 0.3, 0.6, 0.9, 1.0, and 1.1) were uniaxially pressed and sintered under high vacuum at 1625 °C to obtain ˜97% dense structures with closed porosity. Sintered compacts were then subjected to 200 MPa argon gas at temperatures between 1750 and 1900 °C to reach full density. It was observed that a small portion of the Eu3+ ions were exsolved from the Lu2O3 cubic crystal lattice and concentrated at the grain boundaries, where they precipitated into a secondary monoclinic phase creating optical scattering defects. Addition of Gd3+ ions into the Lu2O3 cubic lattice formed the solid solution (Gd,Lu)2O3:Eu and stretched the lattice parameter allowing the larger Eu3+ ions to stay in solid solution, reducing the secondary phase and improving the transparency of the ceramics. Excess gadolinium, however, resulted in a complete phase transformation to monoclinic at pressures and temperatures sufficient for densification. Light yield performance was measured and all samples show equal amounts of the characteristic Eu3+ luminescence, indicating gadolinium addition had no adverse effect. This material has potential to improve the performance of high energy radiography devices.

68Ga/177Lu-labeled DOTA-TATE shows similar imaging and biodistribution in neuroendocrine tumor model.

PubMed

Liu, Fei; Zhu, Hua; Yu, Jiangyuan; Han, Xuedi; Xie, Qinghua; Liu, Teli; Xia, Chuanqin; Li, Nan; Yang, Zhi

2017-06-01

Somatostatin receptors are overexpressed in neuroendocrine tumors, whose endogenous ligands are somatostatin. DOTA-TATE is an analogue of somatostatin, which shows high binding affinity to somatostatin receptors. We aim to evaluate the 68 Ga/ 177 Lu-labeling DOTA-TATE kit in neuroendocrine tumor model for molecular imaging and to try human-positron emission tomography/computed tomography imaging of 68 Ga-DOTA-TATE in neuroendocrine tumor patients. DOTA-TATE kits were formulated and radiolabeled with 68 Ga/ 177 Lu for 68 Ga/ 177 Lu-DOTA-TATE (M-DOTA-TATE). In vitro and in vivo stability of 177 Lu-DOTA-TATE were performed. Nude mice bearing human tumors were injected with 68 Ga-DOTA-TATE or 177 Lu-DOTA-TATE for micro-positron emission tomography and micro-single-photon emission computed tomography/computed tomography imaging separately, and clinical positron emission tomography/computed tomography images of 68 Ga-DOTA-TATE were obtained at 1 h post-intravenous injection from patients with neuroendocrine tumors. Micro-positron emission tomography and micro-single-photon emission computed tomography/computed tomography imaging of 68 Ga-DOTA-TATE and 177 Lu-DOTA-TATE both showed clear tumor uptake which could be blocked by excess DOTA-TATE. In addition, 68 Ga-DOTA-TATE-positron emission tomography/computed tomography imaging in neuroendocrine tumor patients could show primary and metastatic lesions. 68 Ga-DOTA-TATE and 177 Lu-DOTA-TATE could accumulate in tumors in animal models, paving the way for better clinical peptide receptor radionuclide therapy for neuroendocrine tumor patients in Asian population.

Calculations of steady and transient channel flows with a time-accurate L-U factorization scheme

NASA Technical Reports Server (NTRS)

Kim, S.-W.

1991-01-01

Calculations of steady and unsteady, transonic, turbulent channel flows with a time accurate, lower-upper (L-U) factorization scheme are presented. The L-U factorization scheme is formally second-order accurate in time and space, and it is an extension of the steady state flow solver (RPLUS) used extensively to solve compressible flows. A time discretization method and the implementation of a consistent boundary condition specific to the L-U factorization scheme are also presented. The turbulence is described by the Baldwin-Lomax algebraic turbulence model. The present L-U scheme yields stable numerical results with the use of much smaller artificial dissipations than those used in the previous steady flow solver for steady and unsteady channel flows. The capability to solve time dependent flows is shown by solving very weakly excited and strongly excited, forced oscillatory, channel flows.

Tumour control probability derived from dose distribution in homogeneous and heterogeneous models: assuming similar pharmacokinetics, 125Sn-177Lu is superior to 90Y-177Lu in peptide receptor radiotherapy

NASA Astrophysics Data System (ADS)

Walrand, Stephan; Hanin, François-Xavier; Pauwels, Stanislas; Jamar, François

2012-07-01

Clinical trials on 177Lu-90Y therapy used empirical activity ratios. Radionuclides (RN) with larger beta maximal range could favourably replace 90Y. Our aim is to provide RN dose-deposition kernels and to compare the tumour control probability (TCP) of RN combinations. Dose kernels were derived by integration of the mono-energetic beta-ray dose distributions (computed using Monte Carlo) weighted by their respective beta spectrum. Nine homogeneous spherical tumours (1-25 mm in diameter) and four spherical tumours including a lattice of cold, but alive, spheres (1, 3, 5, 7 mm in diameter) were modelled. The TCP for 93Y, 90Y and 125Sn in combination with 177Lu in variable proportions (that kept constant the renal cortex biological effective dose) were derived by 3D dose kernel convolution. For a mean tumour-absorbed dose of 180 Gy, 2 mm homogeneous tumours and tumours including 3 mm diameter cold alive spheres were both well controlled (TCP > 0.9) using a 75-25% combination of 177Lu and 90Y activity. However, 125Sn-177Lu achieved a significantly better result by controlling 1 mm-homogeneous tumour simultaneously with tumours including 5 mm diameter cold alive spheres. Clinical trials using RN combinations should use RN proportions tuned to the patient dosimetry. 125Sn production and its coupling to somatostatin analogue appear feasible. Assuming similar pharmacokinetics 125Sn is the best RN for combination with 177Lu in peptide receptor radiotherapy justifying pharmacokinetics studies in rodent of 125Sn-labelled somatostatin analogues.

Comparative biodistributions and dosimetry of [¹⁷⁷Lu]DOTA-anti-bcl-2-PNA-Tyr³-octreotate and [¹⁷⁷Lu]DOTA-Tyr³-octreotate in a mouse model of B-cell lymphoma/leukemia.

PubMed

Balkin, Ethan R; Liu, Dijie; Jia, Fang; Ruthengael, Varyanna C; Shaffer, Suzanne M; Miller, William H; Lewis, Michael R

2014-01-01

The B-cell lymphoma/leukemia-2 (bcl-2) proto-oncogene in non-Hodgkin's lymphoma (NHL) is a dominant inhibitor of apoptosis. We developed a (177)Lu-labeled bcl-2 antisense peptide nucleic acid (PNA)-peptide conjugate designed for dual modality NHL therapy, consisting of a radiopharmaceutical capable of simultaneously down-regulating apoptotic resistance and delivering cytotoxic internally emitted radiation. DOTA-anti-bcl-2-Tyr(3)-octreotate was synthesized, labeled with (177)Lu, and purified using RP-HPLC. The PNA-peptide conjugate was evaluated in Mec-1 NHL-bearing mice and compared to [(177)Lu]DOTA-Tyr(3)-octreotate in biodistribution and excretion studies. These data were then used to generate in vivo dosimetry models. The PNA-peptide conjugate was readily prepared and radiolabeled in high yield and radiochemical purity. An in vivo blocking study determined that administration of 50 μg of non-radioactive PNA-peptide was the optimal mass for maximum delivery to the tumor. Based on that result, a dosing regimen of (177)Lu-PNA-peptide, for radiologic effect, followed by the optimal mass of non-radioactive compound, for antisense effect, was designed. Using that dosing regimen, biodistribution of the PNA-peptide showed uptake in the tumor with minimal washout over a 4-day period. Uptakes in receptor-positive normal organs were low and displayed nearly complete washout by 24h. Dosimetry models showed that the tumor absorbed dose of the PNA-peptide conjugate was approximately twice that of the peptide-only conjugate. Biodistribution data showed specific tumor targeting of the (177)Lu-labeled PNA-peptide compound with minimal receptor-positive normal tissue uptake when compared to [(177)Lu]DOTA-Tyr(3)-octreotate. In vivo dosimetry models predicted a more favorable tumor absorbed dose from [(177)Lu]DOTA-anti-bcl-2-Tyr(3)-octreotate. © 2013.

Luminescent LuVO4:Ln3+ (Ln = Eu, Sm, Dy, Er) hollow porous spheres for encapsulation of biomolecules

NASA Astrophysics Data System (ADS)

Li, Dan; Liu, Chunlei; Jiang, Lianzhou

2015-10-01

In this study, LuVO4:Ln3+ (Ln = Eu, Sm, Dy, Er) hollow porous spheres, synthesized via self-sacrificing templated route, are developed for enzyme immobilization and protein adsorption. The four LuVO4 hollow spheres with diameter of 180 nm, 280 nm, 370 nm and 480 nm were obtained. The size of LuVO4 hollow sphere is dependent on Lu(OH)CO3 template. Upon excitation by UV light, hollow LuVO4:Ln3+ (Ln = Eu, Sm, Dy, Er) spheres exhibit red (Eu3+), orange (Sm3+), yellow-green (Dy3+), and green (Er3+) emissions. The good biocompatibility of sample is validated by MTT assay. Due to structure feature and size of obtained sample, the rapid encapsulation of biomolecules within samples has been achieved. Furthermore, the hollow spheres show different biomolecules adsorption capacities at different buffer solution pH values. The release behaviors of two kinds of biomolecules (lysozyme and bovine serum albumin) are also investigated. LuVO4 hollow spheres are suitable carriers for biomolecules. The emission intensity of Eu3+ in the LuVO4:Eu3+ varies with the released amount of LYZ. This enables the monitoring of release process by the change in the luminescence intensity.

Fabrication and properties of Eu:Lu2O3 transparent ceramics for X-ray radiation detectors

NASA Astrophysics Data System (ADS)

Xie, Weifeng; Wang, Jing; Cao, Maoqing; Hu, Zewang; Feng, Yagang; Chen, Xiaopu; Jiang, Nan; Dai, Jiawei; Shi, Yun; Babin, Vladimir; Mihóková, Eva; Nikl, Martin; Li, Jiang

2018-06-01

Europium-doped lutetium oxide (Eu:Lu2O3) nano-powders were synthesized by a co-precipitation method from europium and lutetium nitrates using ammonium hydrogen carbonate (AHC) as the precipitant. Fine and low-agglomerated powders with average particle size of 68 nm were obtained by calcining the precursor at 1100 °C for 4 h. Using this powder as starting material, Eu:Lu2O3 transparent ceramics with the average grain size of ∼46 μm were fabricated by vacuum sintering at 1650 °C for 30 h, whose in-line transmittance reaches 66.3% at 611 nm. The influences of air annealing on optical transmittance, decay time, spectroscopic properties, light output and thermally stimulated luminescence of Eu:Lu2O3 ceramics were investigated in detail. Based on radioluminescence spectra, the light output of the annealed Eu:Lu2O3 ceramics is 10 times higher than that of the commercially available BGO single crystal, and it indicates that transparent Eu:Lu2O3 scintillation ceramics is a promising candidate for X-ray radiation detectors.

Orthopaedic techniques of Sabuncuoğlu in the 15th century Ottoman period.

PubMed

Sarban, Sezgin; Aksoy, Sahin; Uzel, Ilter; Işikan, Uğur E; Atik, Sahap

2005-10-01

Serefeddin Sabuncuoğlu (1385-1468) was the author of the surgical textbook Cerrahiyyetü'l-Haniyye (Imperial Surgery). It was the first illustrated surgical textbook in the Turkish-Islamic medical literature. Cerrahiyyetü'l-Haniyye is significant because it includes Sabuncuoğlu's color illustrations of surgical procedures, incisions, fracture dislocation reduction techniques, and instruments. There are only three handwritten copies. Two originally were written by Sabuncuoğlu and are exhibited in Paris and Istanbul. The book was rediscovered in 1936, but some parts are suspected to be missing. The book currently consists of three chapters divided into 193 sections. The third chapter includes orthopaedics and traumatology, reduction techniques of lower and upper extremities, fractures and dislocations, and relevant Greek, Arabic, and Persian textbooks are cited. Sabuncuoğlu also wrote about surgical treatment of congenital hand anomalies. He was the first to advise placing a wooden splint under the palmar side after hand surgery. We reviewed the sections of Cerrahiyyetü'l-Haniyye related to orthopaedics and traumatology. Compared with previous writings by Hippocrates, Ibn-i Sina, and Al-Zahrawi, there are no major differences in the treatment of fracture dislocations.

Synthesis of Oligosaccharides Derived from Lactulose (OsLu) Using Soluble and Immobilized Aspergillus oryzae β-Galactosidase

PubMed Central

Cardelle-Cobas, Alejandra; Olano, Agustin; Irazoqui, Gabriela; Giacomini, Cecilia; Batista-Viera, Francisco; Corzo, Nieves; Corzo-Martínez, Marta

2016-01-01

β-Galactosidase from Aspergillus oryzae offers a high yield for the synthesis of oligosaccharides derived from lactulose (OsLu) by transgalactosylation. Oligosaccharides with degree of polymerization (DP) ≥ 3 have shown to possess higher in vitro bifidogenic effect than di- and tetrasaccharides. Thus, in this work, an optimization of reaction conditions affecting the specific selectivity of A. oryzae β-galactosidase for synthesis of OsLu has been carried out to enhance OsLu with DP ≥ 3 production. Assays with β-galactosidase immobilized onto a glutaraldehyde–agarose support were also carried out with the aim of making the process cost-effective and industrially viable. Optimal conditions with both soluble and immobilized enzyme for the synthesis of OsLu with DP ≥ 3 were 50 °C, pH 6.5, 450 g/L of lactulose, and 8 U/mL of enzyme, reaching yields of ca. 50% (w/v) of total OsLu and ca. 20% (w/v) of OsLu with DP 3, being 6′-galactosyl-lactulose the major one, after a short reaction time. Selective formation of disaccharides, however, was favored at 60 °C, pH 4.5, 450 g/L of lactulose and 8 U/mL of enzyme. Immobilization increased the enzymatic stability to temperature changes and allowed to reuse the enzyme. We can conclude that the use, under determined optimal conditions, of the A. oryzae β-galactosidase immobilized on a support of glutaraldehyde–agarose constitutes an efficient and cost-effective alternative to the use of soluble β-galactosidases for the synthesis of prebiotic OsLu mixtures. PMID:27014684

High speed corner and gap-seal computations using an LU-SGS scheme

NASA Technical Reports Server (NTRS)

Coirier, William J.

1989-01-01

The hybrid Lower-Upper Symmetric Gauss-Seidel (LU-SGS) algorithm was added to a widely used series of 2D/3D Euler/Navier-Stokes solvers and was demonstrated for a particular class of high-speed flows. A limited study was conducted to compare the hybrid LU-SGS for approximate Newton iteration and diagonalized Beam-Warming (DBW) schemes on a work and convergence history basis. The hybrid LU-SGS algorithm is more efficient and easier to implement than the DBW scheme originally present in the code for the cases considered. The code was validated for the hypersonic flow through two mutually perpendicular flat plates and then used to investigate the flow field in and around a simplified scramjet module gap seal configuration. Due to the similarities, the gap seal flow was compared to hypersonic corner flow at the same freestream conditions and Reynolds number.

A multigrid LU-SSOR scheme for approximate Newton iteration applied to the Euler equations

NASA Technical Reports Server (NTRS)

Yoon, Seokkwan; Jameson, Antony

1986-01-01

A new efficient relaxation scheme in conjunction with a multigrid method is developed for the Euler equations. The LU SSOR scheme is based on a central difference scheme and does not need flux splitting for Newton iteration. Application to transonic flow shows that the new method surpasses the performance of the LU implicit scheme.

A new photocatalyst of LuFeO3 for the dye degradation

NASA Astrophysics Data System (ADS)

Zhou, M.; Yang, H.; Xian, T.; Zhang, C. R.

2015-08-01

A polyacrylamide gel route was introduced to synthesize LuFeO3 particles, where the effects of calcination temperature, calcination time and chelating agent on the products were investigated. By varying the experimental conditions, several LuFeO3 samples with sphere-, ellipsoid- and worm-like morphologies and average particle sizes of 200-270 nm were prepared. The photocatalytic activity of LuFeO3 samples was evaluated by degrading rhodamine B (RhB) under simulated-sunlight irradiation, revealing that they exhibit a pronounced photocatalytic activity. The effects of p-benzoquinone (BQ), ethanol and oxalic acid (OA) on the photocatalytic efficiency were investigated. It is observed that BQ has almost no effect on the photocatalytic degradation of RhB, ethanol exhibits a substantial suppression of RhB degradation, while OA significantly enhances the photocatalytic efficiency. Hydroxyl (•OH) radicals were examined by fluorimetry using terephthalic acid as a probe molecule, and are found to be produced over the simulated-sunlight irradiated LuFeO3 particles. The addition of ethanol leads to a quenching of •OH radicals, whereas the yield of •OH radicals is highly increased on addition of OA. Based on the experimental results, •OH radicals are suggested to be the dominant active species responsible for the dye degradation, while superoxide (•O2-) radicals play a negligible role in the photocatalysis.

Lu-Hf total-rock age for the Amitsoq gneisses, West Greenland

NASA Technical Reports Server (NTRS)

Pettingill, H. S.; Patchett, P. J.

1981-01-01

Lu-Hf total-rock data for the Amitsoq gneisses of West Greenland yield an age of 3.55 + or - 0.22 billion years, based on the decay constant for Lu-176 of 1.96 x 10 to the -11th/year, and an initial Hf-176/Hf-177 ratio of 0.280482 + or - 33. The result is in good agreement with Rb-Sr total-rock and U-Pb zircon ages. In spite of severe metamorphism of the area at 2.9 billion years, zircons from two of the samples have remained on the total-rock line, and define points close to the initial Hf ratio. The initial Hf-176/Hf-177 lies close to a chondritic Hf isotopic evolution curve from 4.55 billion years to present. This is consistent with the igneous precursors to the Amitsoq gneisses having been derived from the mantle at or shortly before 3.6 billion years. Anomalous relationships between Hf concentration and the Lu-176/Hf-177 ratio may suggest that trace element abundances in the Amitsoq gneisses are partly controlled by processes related to metamorphism.

Fabrication and microstructure of cerium doped lutetium aluminum garnet (Ce:LuAG) transparent ceramics by solid-state reaction method

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

Li, Junlang, E-mail: lijunlangx@163.com; Xu, Jian, E-mail: xu.jian.57z@st.kyoto-u.ac.jp; Graduate School of Human and Environmental Studies, Division of Materials Function, Kyoto University, Kyoto 606-8501

2014-07-01

Highlights: • We fabricate Ce doped lutetium aluminum garnet ceramics by solid-state method. • The raw materials include Lu{sub 2}O{sub 3} nanopowders synthesized by co-precipitation method. • The density of the transparent ceramics reach 99.7% of the theoretical value. • The optical transmittance of the bulk ceramic at 550 nm was 57.48%. • Some scattering centers decrease the optical characteristic of the ceramic. - Abstract: Polycrystalline Ce{sup 3+} doped lutetium aluminum garnet (Ce:LuAG) transparent ceramics fabricated by one step solid-state reaction method using synthetic nano-sized Lu{sub 2}O{sub 3}, commercial α-Al{sub 2}O{sub 3} and CeO{sub 2} powders were investigated in thismore » paper. The green compacts shaped by the mixed powders were successfully densified into Ce:LuAG transparent ceramics after vacuum sintering at 1750 °C for 10 h. The in-line optical transmittance of the Ce:LuAG ceramic made by home-made Lu{sub 2}O{sub 3} powders could reach 57.48% at 550 nm, which was higher than that of the ceramic made by commercial Lu{sub 2}O{sub 3} powders (22.96%). The microstructure observation showed that light scattering centers caused by micro-pores, aluminum segregation and refraction index inhomogeneities induced the decrease of optical transparency of the Ce:LuAG ceramics, which should be removed and optimized in the future work.« less

Lu and Kaleri in Node 1/Unity module

NASA Image and Video Library

2003-10-26

ISS007-E-18035 (26 October 2003) --- Cosmonaut Alexander Y. Kaleri (left), Expedition 8 flight engineer, and astronaut Edward T. Lu, Expedition 7 NASA ISS science officer and flight engineer, hold tools in the Unity node on the International Space Station (ISS). Kaleri represents Rosaviakosmos.

Highly efficient passive mode locking of Nd:Lu2.9Gd0.1Al5O12 garnet crystal

NASA Astrophysics Data System (ADS)

Di, J. Q.; Xu, X. D.; Xia, C. T.; Tan, W. D.; Zhang, J.; Tang, D. Y.; Li, D. Z.; Zhou, D. H.; Wu, F.; Xu, J.

2013-05-01

Passive mode locking of Nd:Lu2.9Gd0.1Al5O12 (Nd:LuGdAG) crystal lasers was experimentally investigated. Stable mode-locked pulses with pulse widths as short as 9.7 ps were obtained for the Nd:LuGdAG crystal; the corresponding maximum output powers were 0.93 W while the mode-locked slope efficiencies were 43%, among the highest efficiencies ever reported for Nd3+ ps lasers. The results demonstrate that Nd:LuGdAG garnet crystal is a promising gain medium for efficient picosecond laser use.

Electronic structures and superconductivity in LuTE2Si2 phases (TE = d-electron transition metal)

NASA Astrophysics Data System (ADS)

Samsel-Czekała, M.; Chajewski, G.; Wiśniewski, P.; Romanova, T.; Hackemer, A.; Gorzelniak, R.; Pikul, A. P.; Kaczorowski, D.

2018-05-01

In the course of our search for unconventional superconductors amidst the 1:2:2 phases, we have re-investigated the LuTE2Si2 compounds with TE = Fe, Co, Ni, Ru, Pd and Pt. In this paper, we present the results of our fully relativistic ab initio calculations of the band structures, performed using the full-potential local-orbital code. The theoretical data are supplemented by the results of low-temperature electrical transport and specific heat measurements performed down to 0.35 K. All the materials studied but LuPt2Si2 crystallize with the body-centered tetragonal ThCr2Si2-type structure (space group I4/mmm). Their Fermi surfaces exhibit a three-dimensional multi-band character. In turn, the Pt-bearing compound adopts the primitive tetragonal CaBe2Ge2-type structure (space group P4/nmm), and its Fermi surface consists of predominantly quasi-two-dimensional sheets. Bulk superconductivity was found only in LuPd2Si2 and LuPt2Si2 (independent of the structure type and dimensionality of the Fermi surface). The key superconducting characteristics indicate a fully-gapped BCS type character. Though the electronic structure of LuFe2Si2 closely resembles that of the unconventional superconductor YFe2Ge2, this Lu-based silicide exhibits neither superconductivity nor spin fluctuations at least down to 0.35 K.

Antidepressant-like activity of the neuropeptide Y Y5 receptor antagonist Lu AA33810: behavioral, molecular, and immunohistochemical evidence.

PubMed

Domin, Helena; Szewczyk, Bernadeta; Pochwat, Bartłomiej; Woźniak, Monika; Śmiałowska, Maria

2017-02-01

It has recently been found that chronic treatment with the highly selective, brain-penetrating Y5 receptor antagonist, Lu AA33810 [N-[[trans-4-[(4,5-dihydro [1] benzothiepino[5,4-d] thiazol-2-yl) amino] cyclohexyl]methyl]-methanesulfonamide], produces antidepressant-like effects in the rat chronic mild stress model. In the present study, we investigated the possible antidepressant-like activity of Lu AA33810 in rats subjected to glial ablation in the prefrontal cortex (PFC) by the gliotoxin L-AAA, which is an astroglial degeneration model of depression. We observed that Lu AA33810 administered intraperitoneally at a single dose of 10 mg/kg both reversed depressive-like behavioral changes in the forced swim test (FST) and prevented degeneration of astrocytes in the mPFC. The mechanism of antidepressant and glioprotective effects of Lu AA33810 has not been studied, so far. We demonstrated the contribution of the noradrenergic rather than the serotonergic pathway to the antidepressant-like action of Lu AA33810 in the FST. Moreover, we found that antidepressant-like effect of Lu AA33810 was connected with the influence on brain-derived neurotrophic factor (BDNF) protein expression. We also demonstrated the antidepressant-like effect of Lu AA33810 in the FST in rats which did not receive the gliotoxin. We found that intracerebroventricular injection of the selective MAPK/ERK inhibitor U0126 (5 μg/2 μl) and the selective PI3K inhibitor LY294002 (10 nmol/2 μl) significantly inhibited the anti-immobility effect of Lu AA33810 in the FST in rats, suggesting that MAPK/ERK and PI3K signaling pathways could be involved in the antidepressant-like effect of Lu AA33810. Our results indicate that Lu AA33810 exerts an antidepressant-like effect and suggest the Y5 receptors as a promising target for antidepressant therapy.

Cubic sub-20 nm NaLuF(4)-based upconversion nanophosphors for high-contrast bioimaging in different animal species.

PubMed

Yang, Tianshe; Sun, Yun; Liu, Qian; Feng, Wei; Yang, Pengyuan; Li, Fuyou

2012-05-01

A new upconversion luminescence (UCL) nanophosphors based on host matrix of cubic NaLuF(4) with bright luminescence have been synthesized by a solvothermal method, facilitate the nanocrystals potential candidates for imaging in vivo, especially large-animals. The sub-20 nm NaLuF(4) co-doped Yb(3+) and Er(3+) (Tm(3+)) showed about 10-fold stronger UCL emission than that of corresponding hexagonal NaYF(4)-based nanocrystals with a 20 nm diameter. Near-infrared to near-infrared (NIR-to-NIR) UCL emission of PAA-coated NaLuF(4):20%Yb,1%Tm (PAA-Lu(Tm)) can penetrate >1.5 cm tissue of pork with high contrast. Based on super-strong UCL emission and deep penetration, PAA-Lu(Tm) as optical bioprobe has been demonstrated by in vivo UCL imaging of a normal black mouse, even rabbit with excellent signal-to-noise ratio. Furthermore, such cubic NaLuF(4)-based nanophosphor was applied in lymph node imaging of live Kunming mouse with rich white fur. Copyright © 2012 Elsevier Ltd. All rights reserved.

Isomeric ratio measurements for the radiative neutron capture 176Lu(n,γ) at DANCE

NASA Astrophysics Data System (ADS)

Denis-Petit, D.; Roig, O.; Méot, V.; Jandel, M.; Vieira, D. J.; Bond, E. M.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Keksis, A. L.; Rundberg, R. S.; Ullmann, J. L.

2016-03-01

The isomeric ratio for the neutron capture reaction 176Lu(n,γ) on the Jπ= 5/2-, 761.7 keV, T1/2=32.8 ns level of 177mLu, has been determined in the neutron energy range 8.5 eV-100 keV for the first time using the DANCE array at the Los Alamos National Laboratory.

A new scheduling algorithm for parallel sparse LU factorization with static pivoting

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

Grigori, Laura; Li, Xiaoye S.

2002-08-20

In this paper we present a static scheduling algorithm for parallel sparse LU factorization with static pivoting. The algorithm is divided into mapping and scheduling phases, using the symmetric pruned graphs of L' and U to represent dependencies. The scheduling algorithm is designed for driving the parallel execution of the factorization on a distributed-memory architecture. Experimental results and comparisons with SuperLU{_}DIST are reported after applying this algorithm on real world application matrices on an IBM SP RS/6000 distributed memory machine.

Atomic Resolution Structure of the Oncolytic Parvovirus LuIII by Electron Microscopy and 3D Image Reconstruction.

PubMed

Pittman, Nikéa; Misseldine, Adam; Geilen, Lorena; Halder, Sujata; Smith, J Kennon; Kurian, Justin; Chipman, Paul; Janssen, Mandy; Mckenna, Robert; Baker, Timothy S; D'Abramo, Anthony; Cotmore, Susan; Tattersall, Peter; Agbandje-McKenna, Mavis

2017-10-30

LuIII, a protoparvovirus pathogenic to rodents, replicates in human mitotic cells, making it applicable for use to kill cancer cells. This virus group includes H-1 parvovirus (H-1PV) and minute virus of mice (MVM). However, LuIII displays enhanced oncolysis compared to H-1PV and MVM, a phenotype mapped to the major capsid viral protein 2 (VP2). This suggests that within LuIII VP2 are determinants for improved tumor lysis. To investigate this, the structure of the LuIII virus-like-particle was determined using single particle cryo-electron microscopy and image reconstruction to 3.17 Å resolution, and compared to the H-1PV and MVM structures. The LuIII VP2 structure, ordered from residue 37 to 587 (C-terminal), had the conserved VP topology and capsid morphology previously reported for other protoparvoviruses. This includes a core β-barrel and α-helix A, a depression at the icosahedral 2-fold and surrounding the 5-fold axes, and a single protrusion at the 3-fold axes. Comparative analysis identified surface loop differences among LuIII, H-1PV, and MVM at or close to the capsid 2- and 5-fold symmetry axes, and the shoulder of the 3-fold protrusions. The 2-fold differences cluster near the previously identified MVM sialic acid receptor binding pocket, and revealed potential determinants of protoparvovirus tumor tropism.

Surgery on varicose veins in the early Ottoman period performed by Serefeddin Sabuncuoğlu.

PubMed

Darçin, Osman Tansel; Andaç, Mehmet Halit

2003-07-01

Serefeddin Sabuncuoğlu, a pioneer of surgery, is known to be the author of first illustrated surgery textbook, Cerrahiyyetu'l Haniyye (Imperial Surgery), which was written in Turkish in 1465 AD at the age of 80 years. The purpose of this article is to describe his contributions to varicose vein surgery. In addition to vascular surgery, Serefeddin Sabuncuoğlu was interested in a wide range of surgical specialities including thoracic surgery, general surgery, pediatric surgery, ophthalmology, orthopedic surgery, urologic surgery, and obstetrics and gynecology. His book was the first illustrated textbook of surgery in the Turkish medical literature, containing color illustrations of surgical procedures, incisions, and instruments. The book has been known of for only the past 60 years. There are 137 different medical observations and recommendations in Cerrahiyyetu'l Haniyye, along with translated passages from the works of Ebu Kasim-ul Zahravi (Albucasis), Al-Tasrif (Textbook of Surgery), including Sabuncuoğlu's additional original contributions. In chapter 90 of the book, Sabuncuoğlu describes lower extremity varices and their surgical treatment and provides a few color illustrations. Although not recognized and rewarded in his time, Serefeddin Sabuncuoğlu was a great surgeon in Turkish-Islamic medical history. This review demonstrates that his textbook, Cerrahiyyetu'l Haniyye, was the first illustrated textbook including various surgical procedures, incisions, and instruments of varicose vein surgery.

Synthesis and luminescent properties of uniform monodisperse LuPO4:Eu3+/Tb3+ hollow microspheres

PubMed Central

Gao, Yu; Yu, He; Shi, Cheng; Zhao, Guiyan; Bi, Yanfeng; Ding, Fu; Sun, Yaguang; Xu, Zhenhe

2017-01-01

Uniform monodisperse LuPO4:Eu3+/Tb3+ hollow microspheres with diameters of about 2.4 µm have been successfully synthesized by the combination of a facile homogeneous precipitation approach, an ion-exchange process and a calcination process. The possible formation mechanism for the hollow microspheres was presented. Furthermore, the luminescence properties revealed that the LuPO4:Eu3+ and LuPO4:Tb3+ phosphors show strong orange-red and green emissions under ultraviolet excitation, respectively, which endows this material with potential application in many fields, such as light display systems and optoelectronic devices. Since the synthetic process can be carried out at mild conditions, it should be straightforward to scale up the entire process for large-scale production of the LuPO4 hollow microspheres. Furthermore, this general and simple method may be of much significance in the synthesis of many other inorganic materials. PMID:29308268

Synthesis and luminescent properties of uniform monodisperse LuPO4:Eu3+/Tb3+ hollow microspheres

NASA Astrophysics Data System (ADS)

Gao, Yu; Yu, He; Shi, Cheng; Zhao, Guiyan; Bi, Yanfeng; Xu, Baotong; Ding, Fu; Sun, Yaguang; Xu, Zhenhe

2017-12-01

Uniform monodisperse LuPO4:Eu3+/Tb3+ hollow microspheres with diameters of about 2.4 µm have been successfully synthesized by the combination of a facile homogeneous precipitation approach, an ion-exchange process and a calcination process. The possible formation mechanism for the hollow microspheres was presented. Furthermore, the luminescence properties revealed that the LuPO4:Eu3+ and LuPO4:Tb3+ phosphors show strong orange-red and green emissions under ultraviolet excitation, respectively, which endows this material with potential application in many fields, such as light display systems and optoelectronic devices. Since the synthetic process can be carried out at mild conditions, it should be straightforward to scale up the entire process for large-scale production of the LuPO4 hollow microspheres. Furthermore, this general and simple method may be of much significance in the synthesis of many other inorganic materials.

Intrinsic electrical properties of LuFe2O4

NASA Astrophysics Data System (ADS)

Lafuerza, Sara; García, Joaquín; Subías, Gloria; Blasco, Javier; Conder, Kazimierz; Pomjakushina, Ekaterina

2013-08-01

We here revisit the electrical properties of LuFe2O4, compound candidate for exhibiting multiferroicity. Measurements of dc electrical resistivity as a function of temperature, electric-field polarization measurements at low temperatures with and without magnetic field, and complex impedance as a function of both frequency and temperature were carried out in a LuFe2O4 single crystal, perpendicular and parallel to the hexagonal c axis, and in several ceramic polycrystalline samples. Resistivity measurements reveal that this material is a highly anisotropic semiconductor, being about two orders of magnitude more resistive along the c axis. The temperature dependence of the resistivity indicates a change in the conduction mechanism at TCO ≈ 320 K from thermal activation above TCO to variable range hopping below TCO. The resistivity values at room temperature are relatively small and are below 5000 Ω cm for all samples but we carried out polarization measurements at sufficiently low temperatures, showing that electric-field polarization curves are a straight line as expected for a paraelectric or antiferroelectric material. Furthermore, no differences are found in the polarization curves when a magnetic field is applied either parallel or perpendicular to the electric field. The analysis of the complex impedance data corroborates that the claimed colossal dielectric constant is a spurious effect mainly derived from the capacitance of the electrical contacts. Therefore, our data unequivocally evidence that LuFe2O4 is not ferroelectric.

An In-Depth Analysis of the Chung-Lu Model

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

Winlaw, M.; DeSterck, H.; Sanders, G.

2015-10-28

In the classic Erd}os R enyi random graph model [5] each edge is chosen with uniform probability and the degree distribution is binomial, limiting the number of graphs that can be modeled using the Erd}os R enyi framework [10]. The Chung-Lu model [1, 2, 3] is an extension of the Erd}os R enyi model that allows for more general degree distributions. The probability of each edge is no longer uniform and is a function of a user-supplied degree sequence, which by design is the expected degree sequence of the model. This property makes it an easy model to work withmore » theoretically and since the Chung-Lu model is a special case of a random graph model with a given degree sequence, many of its properties are well known and have been studied extensively [2, 3, 13, 8, 9]. It is also an attractive null model for many real-world networks, particularly those with power-law degree distributions and it is sometimes used as a benchmark for comparison with other graph generators despite some of its limitations [12, 11]. We know for example, that the average clustering coe cient is too low relative to most real world networks. As well, measures of a nity are also too low relative to most real-world networks of interest. However, despite these limitations or perhaps because of them, the Chung-Lu model provides a basis for comparing new graph models.« less

Comparative study of optical and scintillation properties of Tm3+:YAG, and Tm3+:LuAG single crystals

NASA Astrophysics Data System (ADS)

Fujimoto, Yutaka; Sugiyama, Makoto; Yanagida, Takayuki; Wakahara, Shingo; Suzuki, Shotaro; Kurosawa, Shunsuke; Chani, Valery; Yoshikawa, Akira

2013-09-01

The optical and scintillation properties of Tm3+-doped yttrium aluminum garnet Y3Al5O12 (YAG) and Tm3+-doped lutetium aluminum garnet Lu3Al5O12 (LuAG) are compared. The Tm3+-doped single crystals were grown by the micro-pulling down (μ-PD) technique. Both crystals demonstrated some emission peaks originated from 4f-4f forbidden transition of Tm3+ under 241Am alpha-ray excitation. The scintillation decay time of Tm3+-doped YAG was similar to that of LuAG. When irradiated by the gamma-rays from a 137Cs source, the relative scintillation light yields of Tm:YAG was 90% greater than that of Tm:LuAG.

The {alpha}-particle excited scintillation response of the liquid phase epitaxy grown LuAG:Ce thin films

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

Prusa, P.; Cechak, T.; Mares, J. A.

2008-01-28

Liquid phase epitaxy grown Lu{sub 3}Al{sub 5}O{sub 12}:Ce (LuAG:Ce) 20 {mu}m thick films and plate cut from the bulk Czochralski-grown LuAG:Ce crystal were prepared for comparison of photoelectron yield (PhY) and PhY dependence on shaping time (0.5-10 {mu}s). {sup 241}Am ({alpha} particles) was used for excitation. At the 0.5 {mu}s shaping time, the best film shows comparable PhY with the bulk sample. PhY of bulk material increases noticeably more with shaping time than that of the films. Energy resolution of films is better. Influence of Pb{sup 2+} contamination in the films (from the flux) and antisite Lu{sub Al} defect inmore » bulk material is discussed.« less

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

PubMed

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

2012-06-01

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

CW and tunable performances of Yb3+:LuAG transparent ceramics with different doping concentrations

NASA Astrophysics Data System (ADS)

Ma, Chaoyang; Zhu, Jiangfeng; Liu, Kai; Wen, Zicheng; Ma, Ran; Long, Jiaqi; Yuan, Xuanyi; Cao, Yongge

2017-07-01

We report the CW laser operation and wavelength tunability of 10 at%, 15 at% and 20 at% Yb3+-doping LuAG ceramics pumped at 970 nm. The absorption saturation effects were taken into account herein. For 10 at% Yb3+-doping sample, the maximum slop efficiency and output power was 60.7% and 1.8 W, respectively. Furthermore, the slop efficiencies of 52.3% (15 at%) and 46.5% (20 at%) were reported. What's more, the maximum optical-to-optical efficiency for our samples was determined to be 40.1%, 36.8%, and 33.1% at the incident pump power of 4 W, respectively. The round-trip cavity loss of the laser system based on our Yb3+:LuAG ceramics were evaluated. The tuning curve of a 20 at% Yb3+:LuAG ceramic extended from 1018 nm up to 1062 nm, and that of 10 at% and 15 at% samples became much more broader, making Yb3+:LuAG ceramics possible candidates for ultrashort pulse generation.

Autonomous parvovirus LuIII encapsidates equal amounts of plus and minus DNA strands

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

Bates, R.C.; Snyder, C.E.; Banerjee, P.T.

1984-02-01

Autonomous parvoviruses are thought to uniquely encapsidate single-stranded DNA of minus polarity. In contrast, the defective adeno-associated viruses separately encapsidate equal amounts of plus and minus DNA strands. The uniqueness of minus strand encapsidation is reexamined for the autonomous parvoviruses. Although it was found that Kilham rat virus and H-1 virus encapsidate varying but small amounts of complementary-strand DNA, it was unexpected to find that LuIII virus encapsidated equal amounts of plus and minus DNA. The extracted LuIII DNA possessed properties of double-stranded replicative-form DNA, including insensitivity to S1 endonuclease, cleavage by restriction enzymes, and conversion to unit-length, single-stranded DNAmore » when electrophoresed under denaturing conditions. However, the inability of this DNA to form single-stranded DNA circles when denatured and then renatured in the presence of formamide and the lack of double-stranded DNA circle formation after treatment with exonuclease III and reannealing shows a lack of sequence homology of the 3' and 5' termini of LuIII DNA, in contrast to adeno-associated virus DNA. Digestion of LuIII double-stranded DNA with EcoRI and HincII and separation of plus and minus DNA strands on composite agarose-acrylamide gels identified a heterogeneity present only in the plus DNA strand. These results suggest that strand specificity of viral DNA encapsidation is not a useful property for differentiation between the autonomous and defective parvoviruses. Furthermore, encapsidation by LuIII of equal amounts of complementary DNA strands in contrast to encapsidation of minus strands by H-1 virus, when propagated in the same host cell type, suggests that selection of strands for encapsidation is a virus-coded rather than host-controlled event.« less

Adaptive control of servo system based on LuGre model

NASA Astrophysics Data System (ADS)

Jin, Wang; Niancong, Liu; Jianlong, Chen; Weitao, Geng

2018-03-01

This paper established a mechanical model of feed system based on LuGre model. In order to solve the influence of nonlinear factors on the system running stability, a nonlinear single observer is designed to estimate the parameter z in the LuGre model and an adaptive friction compensation controller is designed. Simulink simulation results show that the control method can effectively suppress the adverse effects of friction and external disturbances. The simulation show that the adaptive parameter kz is between 0.11-0.13, and the value of gamma1 is between 1.9-2.1. Position tracking error reaches level 10-3 and is stabilized near 0 values within 0.3 seconds, the compensation method has better tracking accuracy and robustness.

[177Lu-DOTA]0-D-Phe1-Tyr3-Octreotide (177Lu-DOTATOC) For Peptide Receptor Radiotherapy in Patients with Advanced Neuroendocrine Tumours: A Phase-II Study

PubMed Central

Baum, Richard P.; Kluge, Andreas W.; Kulkarni, Harshad; Schorr-Neufing, Ulrike; Niepsch, Karin; Bitterlich, Norman; van Echteld, Cees J.A.

2016-01-01

Purpose: To characterise efficacy and safety of 177Lu-DOTATOC as agent for peptide receptor radiotherapy (PRRT) of advanced neuroendocrine tumours (NET). Patients and methods: Fifty-six subjects with metastasized and progressive NET (50% gastroenteral, 26.8% pancreatic, 23.2% other primary sites) treated consecutively with 177Lu-DOTATOC were analysed retrospectively. Subjects were administered 177Lu-DOTATOC (mean 2.1 cycles; range 1-4) as 7.0GBq (median) doses at three-monthly intervals. Efficacy was analysed using CT and/or MRI according to RECIST 1.1 criteria and results were stratified for the number of administered cycles and the primary tumour origin. Results: In the total NET population (A), median progression-free (PFS) and overall survival (OS) were 17.4 and 34.2 months, respectively, assessed in a follow-up time (mean ± SD) of 16.1 ± 12.4 months. In patients receiving more than one cycle, mean follow-up time was 22.4 ± 11.0 months for all NETs (B) and PFS was 32.0 months for all NETs (B), 34.5 months for GEP-NET (C), and 11.9 months for other NETs (D). Objective response rates (Complete/Partial Responses) were 33.9%, 40.6%, 54.2%, and 0% for A, B, C, and D groups, respectively, while disease control rates in the same were 66.1%, 93.8%, 100%, and 75%. Complete responses (16.1%, 18.8% and 25.0% for groups A, B and C) were high, 78% of which were maintained throughout the follow up. There were no serious adverse events. One case of self-limiting grade 3 myelotoxicity was reported. Although 20% of patients had mild renal insufficiency at baseline, there was no evidence of exacerbated or de novo renal toxicity after treatment. Conclusion: 177Lu-DOTATOC is a novel agent for PRRT with major potential to induce objective tumour responses and sustained disease control in progressive neuroendocrine tumours, even when administered in moderate activities. The observed safety profile suggests a particularly favourable therapeutic index, including in patients with

Effects of Gd/Lu ratio on the luminescence properties and garnet phase stability of Ce3+ activated GdxLu3-xAl5O12 single crystals

NASA Astrophysics Data System (ADS)

Bartosiewicz, K.; Babin, V.; Kamada, K.; Yoshikawa, A.; Beitlerova, A.; Nikl, M.

2018-06-01

The luminescence properties of Ce3+ activated (Gd,Lu)3Al5O12 single crystals are investigated as a function of the Gd/Lu ratio with the aim of an improved understanding of the luminescence quenching, energy transfer processes, and garnet phase stability. Upon heavy substitution of Lu with Gd, the target garnet phase becomes thermodynamically unstable and unwanted secondary phase inclusions arise. The secondary phase shows luminescence properties in the UV spectral range. The thermal quenching process of the 5d→4f emission of Ce3+ in the garnet phase is determined by the temperature dependence of the photoluminescence decay time and delayed radiative recombination decays. The results show that the onset of the thermal quenching is moved to lower temperatures with increasing the Gd3+ content. The main mechanism responsible for the luminescence quenching is due to the non-radiative relaxation from 5d1 excited state to 4f ground state of Ce3+. The energy transfer processes between Gd3+ and Ce3+ as well as between secondary and garnet phase are evidenced by the photoluminescence excitation and emission spectra as well as decay kinetic measurements.

Crystal Growth and Scintillation Properties of Ho-Doped Lu3Al5O12 Single Crystals

NASA Astrophysics Data System (ADS)

Sugiyama, Makoto; Yanagida, Takayuki; Fujimoto, Yutaka; Totsuka, Daisuke; Yokota, Yuui; Kurosawa, Shunsuke; Futami, Yoshisuke; Yoshikawa, Akira

2012-10-01

The crystals of 0.1, 0.5, 1, and 3% Ho doped Lu3Al5O12 (Ho:LuAG) grown by the micro-pulling-down method were examined for their scintillation properties. At wavelengths longer than 300 nm, Ho:LuAG crystals demonstrated around 60% transparency with many absorption peaks attributed to Ho3+ 4f10-4 f10 transitions. When excited by 241Am α-ray to obtain radio luminescence spectra, broad host emission and four sharp Ho3+ 4f10-4 f10 emission peaks were detected in the visible region. Light yields and decay time profiles of the samples irradiated by 137Cs γ-ray were measured using photomultiplier tubes R7600 (Hamamatsu). Ho 0.5%:LuAG showed the highest light yield of 3100 ±310 photons/MeV among the present samples. The decay time profiles were well reproduced by two components exponential approximation consisting of 0.5-1 μs and 3-6 μs.

Comparative study of the compensated semi-metals LaBi and LuBi: a first-principles approach.

PubMed

Dey, Urmimala

2018-05-23

We have investigated the electronic structures of LaBi and LuBi, employing the full-potential all electron method as implemented in Wien2k. Using this, we have studied in detail both the bulk and the surface states of these materials. From our band structure calculations we find that LuBi, like LaBi, is a compensated semi-metal with almost equal and sizable electron and hole pockets. In analogy with experimental evidence in LaBi, we thus predict that LuBi will also be a candidate for extremely large magneto-resistance (XMR), which should be of immense technological interest. Our calculations reveal that LaBi, despite being gapless in the bulk spectrum, displays the characteristic features of a [Formula: see text] topological semi-metal, resulting in gapless Dirac cones on the surface, whereas LuBi only shows avoided band inversion in the bulk and is thus a conventional compensated semi-metal with extremely large magneto-resistance.

Comparative study of the compensated semi-metals LaBi and LuBi: a first-principles approach

NASA Astrophysics Data System (ADS)

Dey, Urmimala

2018-05-01

We have investigated the electronic structures of LaBi and LuBi, employing the full-potential all electron method as implemented in Wien2k. Using this, we have studied in detail both the bulk and the surface states of these materials. From our band structure calculations we find that LuBi, like LaBi, is a compensated semi-metal with almost equal and sizable electron and hole pockets. In analogy with experimental evidence in LaBi, we thus predict that LuBi will also be a candidate for extremely large magneto-resistance (XMR), which should be of immense technological interest. Our calculations reveal that LaBi, despite being gapless in the bulk spectrum, displays the characteristic features of a topological semi-metal, resulting in gapless Dirac cones on the surface, whereas LuBi only shows avoided band inversion in the bulk and is thus a conventional compensated semi-metal with extremely large magneto-resistance.

Atomic Resolution Structure of the Oncolytic Parvovirus LuIII by Electron Microscopy and 3D Image Reconstruction

PubMed Central

Misseldine, Adam; Geilen, Lorena; Halder, Sujata; Smith, J. Kennon; Kurian, Justin; Chipman, Paul; Janssen, Mandy; Mckenna, Robert; Baker, Timothy S.; D’Abramo, Anthony; Cotmore, Susan; Tattersall, Peter; Agbandje-McKenna, Mavis

2017-01-01

LuIII, a protoparvovirus pathogenic to rodents, replicates in human mitotic cells, making it applicable for use to kill cancer cells. This virus group includes H-1 parvovirus (H-1PV) and minute virus of mice (MVM). However, LuIII displays enhanced oncolysis compared to H-1PV and MVM, a phenotype mapped to the major capsid viral protein 2 (VP2). This suggests that within LuIII VP2 are determinants for improved tumor lysis. To investigate this, the structure of the LuIII virus-like-particle was determined using single particle cryo-electron microscopy and image reconstruction to 3.17 Å resolution, and compared to the H-1PV and MVM structures. The LuIII VP2 structure, ordered from residue 37 to 587 (C-terminal), had the conserved VP topology and capsid morphology previously reported for other protoparvoviruses. This includes a core β-barrel and α-helix A, a depression at the icosahedral 2-fold and surrounding the 5-fold axes, and a single protrusion at the 3-fold axes. Comparative analysis identified surface loop differences among LuIII, H-1PV, and MVM at or close to the capsid 2- and 5-fold symmetry axes, and the shoulder of the 3-fold protrusions. The 2-fold differences cluster near the previously identified MVM sialic acid receptor binding pocket, and revealed potential determinants of protoparvovirus tumor tropism. PMID:29084163

Comparative efficacy of 177Lu and 90Y for Anti-CD20 Pretargeted Radioimmunotherapy in Murine Lymphoma Xenograft Models

DOE PAGES

Frost, Sofia H. L.; Frayo, Shani L.; Miller, Brian W.; ...

2015-03-18

Purpose Pretargeted radioimmunotherapy (PRIT) is a multi-step method of selectively delivering high doses of radiotherapy to tumor cells while minimizing exposure to surrounding tissues. Yttrium-90 ( 90Y) and lutetium-177 ( 177Lu) are two of the most promising beta-particle emitting radionuclides used for radioimmunotherapy, which despite having similar chemistries differ distinctly in terms of radiophysical features. These differences may have important consequences for the absorbed dose to tumors and normal organs. Whereas 90Y has been successfully applied in a number of preclinical and clinical radioimmunotherapy settings, there have been few published pretargeting studies with 177Lu. We therefore compared the therapeutic potentialmore » of targeting either 90Y or 177Lu to human B-cell lymphoma xenografts in mice. Methods Parallel experiments evaluating the biodistribution, imaging, dosimetry, therapeutic efficacy, and toxicity were performed in female athymic nude mice bearing either Ramos (Burkitt lymphoma) or Granta (mantle cell lymphoma) xenografts, utilizing an anti-CD20 antibodystreptavidin conjugate (1F5-SA) and an 90Y- or 177Lu-labeled 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-biotin second step reagent. Results The two radionuclides displayed comparable biodistributions in tumors and normal organs; however, the absorbed radiation dose delivered to tumor was more than twice as high for 90Y (1.3 Gy/MBq) as for 177Lu (0.6 Gy/MBq). More importantly, therapy with 90Y-DOTAbiotin was dramatically more effective than with 177Lu-DOTA-biotin, with 100% of Ramos xenograft-bearing mice cured with 37 MBq 90Y, whereas 0% were cured using identical amounts of 177Lu-DOTA-biotin. Similar results were observed in mice bearing Granta xenografts, with 80% of the mice cured with 90Y-PRIT and 0% cured with 177Lu-PRIT. Toxicities were comparable with both isotopes. Conclusion 90Y was therapeutically superior to 177Lu for streptavidin-biotin PRIT

Comparative efficacy of 177Lu and 90Y for Anti-CD20 Pretargeted Radioimmunotherapy in Murine Lymphoma Xenograft Models

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

Frost, Sofia H. L.; Frayo, Shani L.; Miller, Brian W.

Purpose Pretargeted radioimmunotherapy (PRIT) is a multi-step method of selectively delivering high doses of radiotherapy to tumor cells while minimizing exposure to surrounding tissues. Yttrium-90 ( 90Y) and lutetium-177 ( 177Lu) are two of the most promising beta-particle emitting radionuclides used for radioimmunotherapy, which despite having similar chemistries differ distinctly in terms of radiophysical features. These differences may have important consequences for the absorbed dose to tumors and normal organs. Whereas 90Y has been successfully applied in a number of preclinical and clinical radioimmunotherapy settings, there have been few published pretargeting studies with 177Lu. We therefore compared the therapeutic potentialmore » of targeting either 90Y or 177Lu to human B-cell lymphoma xenografts in mice. Methods Parallel experiments evaluating the biodistribution, imaging, dosimetry, therapeutic efficacy, and toxicity were performed in female athymic nude mice bearing either Ramos (Burkitt lymphoma) or Granta (mantle cell lymphoma) xenografts, utilizing an anti-CD20 antibodystreptavidin conjugate (1F5-SA) and an 90Y- or 177Lu-labeled 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-biotin second step reagent. Results The two radionuclides displayed comparable biodistributions in tumors and normal organs; however, the absorbed radiation dose delivered to tumor was more than twice as high for 90Y (1.3 Gy/MBq) as for 177Lu (0.6 Gy/MBq). More importantly, therapy with 90Y-DOTAbiotin was dramatically more effective than with 177Lu-DOTA-biotin, with 100% of Ramos xenograft-bearing mice cured with 37 MBq 90Y, whereas 0% were cured using identical amounts of 177Lu-DOTA-biotin. Similar results were observed in mice bearing Granta xenografts, with 80% of the mice cured with 90Y-PRIT and 0% cured with 177Lu-PRIT. Toxicities were comparable with both isotopes. Conclusion 90Y was therapeutically superior to 177Lu for streptavidin-biotin PRIT

Lu-Hf and Sm-Nd evolution in lunar mare basalts

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

Unruh, D.M.; Stille, P.; Patchett, P.J.

1984-02-15

Lu-Hf and Sm-Nd data for mare basalts combined with Rb-Sr and total REE data taken from the literature suggest that the mare basalts were derived by small (< or =10%) degrees of partial melting of cumulate sources, but that the magma ocean from which these sources formed was light REE and Hf-enriched. Calculated source compositions range fromm lherzolite to olivine websterite. Nonmodal melting of small amounts of ilmenite (< or =3%) in the sources seems to be required by the Lu/Hf data. A comparison of the Hf and Nd isotopic characteristics between the mare basalts and terrestrial oceanic basalts revealsmore » that the epsilonHf/epsilonNd ratios of low-Ti mare basalts are much higher than in terrestrial oceanic basalts. The results are qualitatively consistent with the hypothesis that terrestrial basalt sources are partial melt residues whereas mare basalt sources are cumulates. Alternatively, the results may imply that the terrestrial mantle has evolved in two (or more) stages of evolution, and that the net effect was depletion of the mantle during the first approx.1-3 b.y. followed by enrichment during the last 1-2 b.y.; or simply that there is a difference in Lu-Hf crystal-liquid partitioning (relative to Sm-Nd) between the lunar and terrestrial mantles.« less

Competing exchanges and spin-phonon coupling in Eu(1-x)R(x)MnO3 (R=Y, Lu).

PubMed

Mota, D A; Barcelay, Y Romaguera; Tavares, P B; Chaves, M R; Almeida, A; Oliveira, J; Ferreira, W S; Moreira, J Agostinho

2013-06-12

This work is focused on the phase diagrams and physical properties of Y-doped and Lu-doped EuMnO3. The differences in the corresponding phase boundaries in the (x,T) phase diagram could be overcome by considering a scaling of the Y(3+) and Lu(3+) concentrations to the tolerance factor. This outcome evidences that the tolerance factor is in fact a more reliable representative of the lattice deformation induced by doping. The normalization of the phase boundaries using the tolerance factor corroborates previous theoretical outcomes regarding the key role of competitive FM and AFM exchanges in determining the phase diagrams of manganite perovskites. However, significant differences in the nature and number of phases at low temperatures and concentrations could not be explained by just considering the normalization to the tolerance factor. The vertical phase boundary observed just for Lu-doped EuMnO3, close to 10% Lu, is understood by considering a low temperature Peierls-type spin-phonon coupling, which stabilizes the AFM-4 phase in Lu-doped EuMnO3.

Reconciliation of the excess 176Hf conundrum in meteorites: Recent disturbances of the Lu-Hf and Sm-Nd isotope systematics

NASA Astrophysics Data System (ADS)

Bast, Rebecca; Scherer, Erik E.; Sprung, Peter; Mezger, Klaus; Fischer-Gödde, Mario; Taetz, Stephan; Böhnke, Mischa; Schmid-Beurmann, Hinrich; Münker, Carsten; Kleine, Thorsten; Srinivasan, Gopalan

2017-09-01

The long-lived 176Lu-176Hf and 147Sm-143Nd radioisotope systems are commonly used chronometers, but when applied to meteorites, they can reveal disturbances. Specifically, Lu-Hf isochrons commonly yield dates up to ∼300 Myr older than the solar system and varying initial 176Hf/177Hf values. We investigated this problem by attempting to construct mineral and whole rock isochrons for eucrites and angrites. Meteorites from different parent bodies exhibit similar disturbance features suggesting that a common process is responsible. Minerals scatter away from isochron regressions for both meteorite classes, with low-Hf phases such as plagioclase and olivine typically being most displaced above (or left of) reference isochrons. Relatively Hf-rich pyroxene is less disturbed but still to the point of steepening Lu-Hf errorchrons. Using our Lu-Hf and Sm-Nd data, we tested various Hf and Lu redistribution scenarios and found that decoupling of Lu/Hf from 176Hf/177Hf must postdate the accumulation of significant radiogenic 176Hf. Therefore early irradiation or diffusion cannot explain the excess 176Hf. Instead, disturbed meteorite isochrons are more likely caused by terrestrial weathering, contamination, or common laboratory procedures. The partial dissolution of phosphate minerals may predominantly remove rare earth elements including Lu, leaving relatively immobile and radiogenic Hf behind. Robust Lu-Hf (and improved Sm-Nd) meteorite geochronology will require the development of chemical or physical methods for removing unsupported radiogenic Hf and silicate-hosted terrestrial contaminants without disturbing parent-daughter ratios.

Magnetic ground state of the multiferroic hexagonal LuFe O3

NASA Astrophysics Data System (ADS)

Suresh, Pittala; Vijaya Laxmi, K.; Bera, A. K.; Yusuf, S. M.; Chittari, Bheema Lingam; Jung, Jeil; Anil Kumar, P. S.

2018-05-01

The structural, electric, and magnetic properties of bulk hexagonal LuFe O3 are investigated. Single phase hexagonal LuFe O3 has been successfully stabilized in the bulk form without any doping by sol-gel method. The hexagonal crystal structure with P 63c m space group has been confirmed by x-ray-diffraction, neutron-diffraction, and Raman spectroscopy study at room temperature. Neutron diffraction confirms the hexagonal phase of LuFe O3 persists down to 6 K. Further, the x-ray photoelectron spectroscopy established the 3+ oxidation state of Fe ions. The temperature-dependent magnetic dc susceptibility, specific heat, and neutron-diffraction studies confirm an antiferromagnetic ordering below the Néel temperature (TN)˜130 K . Analysis of magnetic neutron-diffraction patterns reveals an in-plane (a b -plane) 120∘ antiferromagnetic structure, characterized by a propagation vector k =(0 0 0 ) with an ordered moment of 2.84 μB/F e3 + at 6 K. The 120∘ antifferomagnetic ordering is further confirmed by spin-orbit coupling density functional theory calculations. The on-site coulomb interaction (U ) and Hund's parameter (JH) on Fe atoms reproduced the neutron-diffraction Γ1 spin pattern among the Fe atoms. P -E loop measurements at room temperature confirm an intrinsic ferroelectricity of the sample with remnant polarization Pr˜0.18 μ C /c m2 . A clear anomaly in the dielectric data is observed at ˜TN revealing the presence of magnetoelectric coupling. A change in the lattice constants at TN has also been found, indicating the presence of a strong magnetoelastic coupling. Thus a coupling between lattice, electric, and magnetic degrees of freedom is established in bulk hexagonal LuFe O3 .

Lu-Hf AND Sm-Nd EVOLUTION IN LUNAR MARE BASALTS.

USGS Publications Warehouse

Unruh, D.M.; Stille, P.; Patchett, P.J.; Tatsumoto, M.

1984-01-01

Lu-Hf and Sm-Nd data for mare basalts combined with Rb-Sr and total REE data taken from the literature suggest that the mare basalts were derived by small ( less than equivalent to 10%) degrees of partial melting of cumulate sources, but that the magma ocean from which these sources formed was light REE and hf-enriched. Calculated source compositions range from lherzolite to olivine websterite. Nonmodal melting of small amounts of ilmenite ( less than equivalent to 3%) in the sources seems to be required by the Lu/Hf data. A comparison of the Hf and Nd isotopic characteristics between the mare basalts and terrestrial oceanic basalts reveals that the epsilon Hf/ epsilon Nd ratios in low-Ti mare basalts are much higher than in terrestrial ocean basalts.

Structure and luminescence properties of Tb3+-doped Lu3Al5O12 films prepared by Pechini sol-gel method

NASA Astrophysics Data System (ADS)

Wang, Jian; Shen, Siqing; Xie, Jianjun; Shi, Ying; Ai, Fei

2011-02-01

Tb3+-doped Lu3Al5O12(hereinafter referred to as LuAG:Tb) films were successfully prepared by Pechini sol-gel process and spin-coating technique on carefully cleaned (111) silicon wafer. The microstructure and optical properties of the LuAG:Tb films were studied by X-ray diffraction (XRD), atomic force microscopy(AFM), as well as photoluminescence (PL) spectra. The XRD results showed that the precursor films started to crystallize at about 900°C. All as-calcined LuAG:Tb films showed the Tb3+ characteristic emission bands.

Structure and luminescence properties of Tb3+-doped Lu3Al5O12 films prepared by Pechini sol-gel method

NASA Astrophysics Data System (ADS)

Wang, Jian; Shen, Siqing; Xie, Jianjun; Shi, Ying; Ai, Fei

2010-10-01

Tb3+-doped Lu3Al5O12(hereinafter referred to as LuAG:Tb) films were successfully prepared by Pechini sol-gel process and spin-coating technique on carefully cleaned (111) silicon wafer. The microstructure and optical properties of the LuAG:Tb films were studied by X-ray diffraction (XRD), atomic force microscopy(AFM), as well as photoluminescence (PL) spectra. The XRD results showed that the precursor films started to crystallize at about 900°C. All as-calcined LuAG:Tb films showed the Tb3+ characteristic emission bands.

Ultra-fast LuI{sub 3}:Ce scintillators for hard x-ray imaging

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

Marton, Zsolt, E-mail: zmarton@rmdinc.com; Miller, Stuart R.; Ovechkina, Elena

We have developed ultra-fast cerium-coped lutetium-iodide (LuI{sub 3}:Ce) films thermally evaporated as polycrystalline, structured scintillator using hot wall epitaxy (HWE) method. The films have shown a 13 ns decay compared to the 28 ns reported for crystals. The fast speed coupled with its high density (∼5.6 g/cm{sup 3}), high effective atomic number (59.7), and the fact that it can be vapor deposited in a columnar form makes LuI{sub 3}:Ce an attractive candidate for high frame rate, high-resolution, hard X-ray imaging. In crystal form, LuI{sub 3}:Ce has demonstrated bright (>100,000 photons/MeV) green (540 nm) emission, which is well matched to commercialmore » CCD/CMOS sensors and is critical for maintaining high signal to noise ratio in light starved applications. Here, we report on the scintillation properties of films and those for corresponding crystalline material. The vapor grown films were integrated into a high-speed CMOS imager to demonstrate high-speed radiography capability. The films were also tested at Advanced Photon Source, Argonne National Laboratory beamline 1-ID under hard X-ray irradiation. The data show a factor of four higher efficiency than the reference LuAG:Ce scintillators, high image quality, and linearity of scintillation response over a wide energy range. The films were employed to perform hard X-ray microtomography, the results of which will also be discussed.« less

MS Malenchenko and MS Lu conduct electrical work in Zvezda during STS-106

NASA Image and Video Library

2000-09-13

S106-E-5202 (13 September 2000) --- Cosmonaut Yuri I. Malenchenko, mission specialist representing the Russian Aviation and Space Agency, teams up with astronaut Edward T. Lu for some electrical work aboard the Zvezda service module on the International Space Station (ISS). Electrical work was the hallmark of the day as four of the mission specialists aboard ISS (temporarily docked with the Space Shuttle Atlantis) replaced batteries inside the Zarya and Zvezda modules while supply transfer continued around them. Astronaut Edward T. Lu, is out of frame at right.

Isomeric ratio measurements for the radiative neutron capture 176Lu(n,γ) at DANCE

NASA Astrophysics Data System (ADS)

Denis-Petit, D.; Roig, O.; Méot, V.; Morillon, B.; Romain, P.; Jandel, M.; Kawano, T.; Vieira, D. J.; Bond, E. M.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Keksis, A. L.; Rundberg, R. S.; Ullmann, J. L.

2017-09-01

The isomeric ratios for the neutron capture reaction 176Lu(n,γ) to the Jπ = 5/2-, 761.7 keV, T1/2 = 32.8 ns and the Jπ = 15/2+, 1356.9 keV, T1/2 = 11.1 ns levels of 177Lu, have been measured for the first time with the Detector for Advanced Neutron Capture Experiments (DANCE) at the Los Alamos National Laboratory. These measured isomeric ratios are compared with TALYS calculations.

177Lu-3BP-227 for Neurotensin Receptor 1-Targeted Therapy of Metastatic Pancreatic Adenocarcinoma: First Clinical Results.

PubMed

Baum, Richard P; Singh, Aviral; Schuchardt, Christiane; Kulkarni, Harshad R; Klette, Ingo; Wiessalla, Stefan; Osterkamp, Frank; Reineke, Ulrich; Smerling, Christiane

2018-05-01

Neurotensin receptor 1 (NTR1) is overexpressed in ductal pancreatic adenocarcinoma, which is still one of the deadliest cancers, with a very poor prognosis. Eligible patients were offered salvage radiopharmaceutical therapy with the novel NTR1 antagonist 177 Lu-3BP-227. Methods: Six patients with confirmed ductal pancreatic adenocarcinoma who had exhausted all other treatment options received 177 Lu-3BP-227 for evaluation of NTR1 expression in vivo. Three patients received treatment activities of 5.1-7.5 GBq. Results: Administration of 177 Lu-3BP-227 was well tolerated by all patients. The kidneys were identified as the dose-limiting organ. The most severe adverse event was reversible grade 2 anemia. One patient achieved a partial response and experienced significant improvement of symptoms and quality of life. This patient survived 13 mo from diagnosis and 11 mo from the start of 177 Lu-3BP-227 therapy. Conclusion: This initial report provides clinical evidence of the feasibility of treatment of ductal pancreatic adenocarcinoma using 177 Lu-3BP-227. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

Sub-10 nm lanthanide doped BaLuF{sub 5} nanocrystals: Shape controllable synthesis, tunable multicolor emission and enhanced near-infrared upconversion luminescence

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

Rao, Ling; Lu, Wei; Wang, Haibo

2015-04-15

Highlights: • Sub-10 nm cubic phase BaLuF{sub 5} nanocrystals were synthesized by a hydrothermal method for the first time. • Tunable multicolor from yellow to yellow-green was achieved by controlling Gd{sup 3+} content in BaLuF{sub 5}:Yb/Er system. • Intense near-infrared upconversion luminescence in BaLuF{sub 5}:Gd/Yb/Tm nanocrystal. • The enhancement near-infrared luminescence can be realized by adjusting the content of Gd{sup 3+} in BaLuF{sub 5}:Gd/Yb/Tm system. - Abstract: In this study, sub-10 nm BaLuF{sub 5} nanocrystals with cubic phase structure were synthesized by a solvothermal method using oleic acid as the stabilizing agent. The as-prepared BaLuF{sub 5} nanocrystals were characterized bymore » transmission electron microscopy (TEM), X-ray diffraction (XRD), and analyzed by the upconversion (UC) spectra. The TEM results reveal that these samples present high uniformity. Compared with Gd-free samples, the size of BaLuF{sub 5}:Yb/Er doped with 10% Gd{sup 3+} decreased to 5.6 nm. In addition, BaLuF{sub 5}:Yb/Tm/Gd upconversion nanoparticles (UCNPs) presented efficient near-infrared (NIR)-NIR UC luminescence. Therefore, it is expected that these ultra-small BaLuF{sub 5} nanocrystals with well-controlled shape, size, and UC emission have potential applications in biomedical imaging fields.« less

Structural, microstructural and vibrational analyses of the monoclinic tungstate BiLuWO{sub 6}

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

Ait Ahsaine, H.; Taoufyq, A.; Institut Matériaux Microélectronique et Nanosciences de Provence, IM2NP, UMR CNRS 7334, Université de Toulon, BP 20132, 83957 La Garde Cedex

2014-10-15

The bismuth lutetium tungstate phase BiLuWO{sub 6} has been prepared using a solid state route with stoichiometric mixtures of oxide precursors. The obtained polycrystalline phase has been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. In the first step, the crystal structure has been refined using Rietveld method: the crystal cell was resolved using monoclinic system (parameters a, b, c, β) with space group A2/m. SEM images showed the presence of large crystallites with a constant local nominal composition (BiLuW). TEM analyses showed that the actual local structure could be better representedmore » by a superlattice (a, 2b, c, β) associated with space groups P2 or P2/m. The Raman spectroscopy showed the presence of vibrational bands similar to those observed in the compounds BiREWO{sub 6} with RE=Y, Gd, Nd. However, these vibrational bands were characterized by large full width at half maximum, probably resulting from the long range Bi/Lu disorder and local WO{sub 6} octahedron distortions in the structure. - Graphical abstract: The average structure of BiLuWO{sub 6} determined from X-ray diffraction data can be represented by A2/m space group. Experimental Electron Diffraction patterns along the [0vw] zone axes of the monoclinic structure and associated simulated patterns show the existence of a monoclinic superstructure with space group P2 or P2/m. - Highlights: • A new monoclinic BiLuWO{sub 6} phase has been elaborated from solid-state reaction. • The space group of the monoclinic disordered average structure should be A2/m. • Transmission electron microscopy leads to a superlattice with P2/m space group. • Raman spectroscopy suggests existence of local disorder.« less

High spin states in 162Lu

NASA Astrophysics Data System (ADS)

Gupta, S. L.; Pancholi, S. C.; Juneja, P.; Mehta, D.; Kumar, Ashok; Bhowmik, R. K.; Muralithar, S.; Rodrigues, G.; Singh, R. P.

1997-09-01

An experimental investigation of the odd-odd 162Lu nucleus, following the 148Sm(19F,5n) reaction at beam energy Elab=112 MeV, has been performed through in-beam gamma-ray spectroscopy. It revealed three signature-split bands. The yrast band based on πh11/2⊗νi13/2 configuration exhibits anomalous signature splitting (the unfavored signature Routhian lying lower than the favored one) whose magnitude Δe'~25 keV, is considerably reduced in contrast to sizable normal signature splitting Δe'~125 and 60 keV observed in the yrast πh11/2 bands of the neighboring odd-A 161,163Lu nuclei, respectively. The signature inversion in this band occurs at spin ~20ħ (frequency=0.37 MeV). The second signature-split band, observed above the band crossing associated with the alignment of a pair of i13/2 quasineutrons, is a band based on the four-quasiparticle [πh11/2[523]7/2-⊗νh9/2[521]3/2-⊗(νi13/2)2], i.e., EABAp(Bp), configuration. The third signature-split band is also likely to be a four-quasiparticle band with configuration similar to the second band but involving F quasineutron, i.e., FABAp(Bp). The experimental results are discussed in comparison with the existing data in the neighboring nuclei and in the framework of the cranking shell model.

Lu plays music with a keyboard in the Destiny module

NASA Image and Video Library

2003-10-26

ISS007-E-18033 (26 October 2003) --- Astronaut Edward T. Lu, Expedition 7 NASA ISS science officer and flight engineer, plays a musical keyboard during off-shift time in the Destiny laboratory on the International Space Station (ISS).

Temperature dependence of the electrical resistivity of LaxLu1-xAs

NASA Astrophysics Data System (ADS)

Rahimi, S.; Krivoy, E. M.; Lee, J.; Michael, M. E.; Bank, S. R.; Akinwande, D.

2013-08-01

We investigate the temperature-dependent resistivity of single-crystalline films of LaxLu1-xAs over the 5-300 K range. The resistivity was separated into lattice, carrier and impurity scattering regions. The effect of impurity scattering is significant below 20 K, while carrier scattering dominates at 20-80 K and lattice scattering dominates above 80 K. All scattering regions show strong dependence on the La content of the films. While the resistivity of 600 nm LuAs films agree well with the reported bulk resistivity values, 3 nm films possessed significantly higher resistivity, suggesting that interfacial roughness significantly impacts the scattering of carriers at the nanoscale limit.

Bright Lu2O3:Eu thin-film scintillators for high-resolution radioluminescence microscopy

PubMed Central

Sengupta, Debanti; Miller, Stuart; Marton, Zsolt; Chin, Frederick; Nagarkar, Vivek

2015-01-01

We investigate the performance of a new thin-film Lu2O3:Eu scintillator for single-cell radionuclide imaging. Imaging the metabolic properties of heterogeneous cell populations in real time is an important challenge with clinical implications. We have developed an innovative technique called radioluminescence microscopy, to quantitatively and sensitively measure radionuclide uptake in single cells. The most important component of this technique is the scintillator, which converts the energy released during radioactive decay into luminescent signals. The sensitivity and spatial resolution of the imaging system depend critically on the characteristics of the scintillator, i.e. the material used and its geometrical configuration. Scintillators fabricated using conventional methods are relatively thick, and therefore do not provide optimal spatial resolution. We compare a thin-film Lu2O3:Eu scintillator to a conventional 500 μm thick CdWO4 scintillator for radioluminescence imaging. Despite its thinness, the unique scintillation properties of the Lu2O3:Eu scintillator allow us to capture single positron decays with over fourfold higher sensitivity, a significant achievement. The thin-film Lu2O3:Eu scintillators also yield radioluminescence images where individual cells appear smaller and better resolved on average than with the CdWO4 scintillators. Coupled with the thin-film scintillator technology, radioluminescence microscopy can yield valuable and clinically relevant data on the metabolism of single cells. PMID:26183115

Controlled processing of (Gd,Ln)2O3:Eu (Ln = Y, Lu) red phosphor particles and compositional effects on photoluminescence

NASA Astrophysics Data System (ADS)

Lu, Bin; Li, Ji-Guang; Sakka, Yoshio

2013-12-01

Synthesis of (Gd0.95-xLnxEu0.05)2O3 (Ln = Y and Lu, x = 0-0.95) powders via ammonium hydrogen carbonate (AHC) precipitation has been systematically studied. The best synthesis parameters are found to be an AHC/total cation molar ratio of 4.5 and an ageing time of 3 h. The effects of Y3+ and Lu3+ substitution for Gd3+, on the nucleation kinetics of the precursors and structural features and optical properties of the oxides, have been investigated. The results show that (i) different nucleation kinetics exist in the Gd-Y-Eu and Gd-Lu-Eu ternary systems, which lead to various morphologies and particle sizes of the precipitated precursors. The (Gd,Y)2O3:Eu precursors display spherical particle morphologies and the particle sizes increase along with more Y3+ addition. The (Gd,Lu)2O3:Eu precursors, on the other hand, are hollow spheres and the particle sizes increase with increasing Lu3+ incorporation, (ii) the resultant oxide powders are ultrafine, narrow in size distribution, well dispersed and rounded in particle shape, (iii) lattice parameters of the two kinds of oxide solid solutions linearly decrease at a higher Y3+ or Lu3+ content. Their theoretical densities linearly decrease with increasing Y3+ incorporation, but increase along with more Lu3+ addition and (iv) the two kinds of phosphors exhibit typical red emissions at ˜613 nm and their charge-transfer bands blue shift at a higher Y3+ or Lu3+ content. Photoluminescence/photoluminescence excitation intensities and external quantum efficiency are found to decrease with increasing value of x, and the fluorescence lifetime mainly depends on the specific surface areas of the powders.

Therapeutic response and side effects of repeated radioligand therapy with 177Lu-PSMA-DKFZ-617 of castrate-resistant metastatic prostate cancer

PubMed Central

Ahmadzadehfar, Hojjat; Eppard, Elisabeth; Kürpig, Stefan; Fimmers, Rolf; Yordanova, Anna; Schlenkhoff, Carl Diedrich; Gärtner, Florian; Rogenhofer, Sebastian; Essler, Markus

2016-01-01

Prostate-specific membrane antigen (PSMA) is highly expressed on prostate epithelial cells and strongly up-regulated in prostate cancer (PC), making it an optimal target for the treatment of metastasized PC. Radioligand therapy (RLT) with 177Lu-PSMA-DKFZ-617 (Lu-PSMA) is a targeted therapy for metastatic PC. In this study, we retrospectively analyzed the side effects and the response rate of 24 hormone and/or chemorefractory PC patients with a mean age of 75.2 years (range: 64–82) with distant metastases and progressive disease according to the PSA level, who were treated with Lu-PSMA. Median PSA was 522 ng/ml (range: 17–2360). Forty-six cycles of Lu-PSMA were performed. Of the 24 patients, 22 received two cycles. Eight weeks after the first cycle of Lu-PSMA therapy 79.1% experienced a decline in PSA level. Eight weeks after the second cycle of Lu-PSMA therapy 68.2% experienced a decline in PSA relative to the baseline value. Apart from two cases of grade 3 anemia, there was no relevant hemato- or nephrotoxicity (grade 3 or 4). These results confirmed that Lu-PSMA is a safe treatment option for metastatic PC patients and has a low toxicity profile. A positive response to therapy in terms of decline in PSA occurs in about 70% of patients. PMID:26871285

ID ICPMS Lu-Hf Geochronology of Apatite from Iron-Oxide Apatite (IOA) Deposits, Northern Chilean Iron Belt.

NASA Astrophysics Data System (ADS)

Zhang, C.; Vervoort, J. D.; Barra, F.; Palma, G.

2017-12-01

Determining the age of mineralization of ore deposits is important for understanding the mechanisms and timing of ore formation. In many cases, however, conventional dateable mineral phases (e.g., zircon, monazite) are lacking in the ore mineral assemblages. For example, Iron Oxide Apatite (IOA) and Iron Oxide Gold Copper Gold (IOCG) deposits have the remaining fundamental question as to whether they have formed by hydrothermal or magmatic processes, or some combination of the two. In these deposits, the mineralization of iron oxide is often accompanied by the growth of apatites, which typically have REE concentrations of tens to several thousand ppm and which makes them potentially amenable to dating by the Lu-Hf isochron method. These apatites, however, also have very low concentrations of Hf, which makes determination of precise Hf isotope compositions challenging. In this study, we attempted to date these deposits using the apatite Lu-Hf isochron method, using procedures modified from that of Münker et al., 2001 and Barfod et al., 2003 and report the first Lu-Hf ages for apatites from Carmen, Fresia, and Mariela IOA deposits in northern Chilean Iron Belt. The concentration of Hf in analyzed apatite is 0.001 ppm. To ensure at least 0.5ng of Hf is collected for MS analysis, 0.5g apatite was dissolved for each sample. A single stage of Ln-spec resin chromatographic columns was used to separate Hf from REEs as multi stages of separation columns would decrease the Hf yield considerably. Using these procedures, we determined a Lu-Hf apatite age for the Carmen deposit of 130.0±1.7 Ma, which is in accordance with a previously published U-Pb apatite age of 131.0±1.0 Ma (Gelcich et al., 2005). The apatites from Fresia and Mariela yield Lu-Hf ages of 132.8±5.3 Ma and 117.3±0.4 Ma respectively. The lower points on the isochrons are either a low Lu/Hf phase (actinolite, magnetite) or bulk earth ratios. These are some of the first Lu-Hf ages of directly dating apatite

Scintillation properties of Tm-doped Lu 3Al 5O 12 single crystals

NASA Astrophysics Data System (ADS)

Sugiyama, Makoto; Fujimoto, Yutaka; Yanagida, Takayuki; Totsuka, Daisuke; Yokota, Yuui; Yoshikawa, Akira

2011-12-01

Using the micro-pulling-down (μ-PD) method, Tm-doped Lu 3Al 5O 12 (Tm:LuAG) single crystals were grown to examine their scintillation properties. In transmittance spectra, they exhibited about 80% transparency in the wavelengths longer than 320 nm and five absorption lines due to Tm 3+ 4f-4f transitions were observed. 241Am α-ray excited radioluminescence spectra were measured and intense 4f-4f emission peaks were observed with the host emission. When excited by 137Cs γ-Ray to obtain pulse height spectra, Tm 1% doped LuAG showed the highest light yield coupled with a photomultiplier (PMT) or a silicon avalanche photodiode (Si-APD). The light yield was estimated to be 5800 and 7300 photons/MeV for PMT and Si-APD, respectively. Decay time profiles consist of two exponential components and the fast and slow components are considered to be attributed to the host and the combination of the host and Tm 3+ 4f-4f emission, respectively.

Structural, microstructural and vibrational analyses of the monoclinic tungstate BiLuWO6

NASA Astrophysics Data System (ADS)

Ait Ahsaine, H.; Taoufyq, A.; Patout, L.; Ezahri, M.; Benlhachemi, A.; Bakiz, B.; Villain, S.; Guinneton, F.; Gavarri, J.-R.

2014-10-01

The bismuth lutetium tungstate phase BiLuWO6 has been prepared using a solid state route with stoichiometric mixtures of oxide precursors. The obtained polycrystalline phase has been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. In the first step, the crystal structure has been refined using Rietveld method: the crystal cell was resolved using monoclinic system (parameters a, b, c, β) with space group A2/m. SEM images showed the presence of large crystallites with a constant local nominal composition (BiLuW). TEM analyses showed that the actual local structure could be better represented by a superlattice (a, 2b, c, β) associated with space groups P2 or P2/m. The Raman spectroscopy showed the presence of vibrational bands similar to those observed in the compounds BiREWO6 with RE=Y, Gd, Nd. However, these vibrational bands were characterized by large full width at half maximum, probably resulting from the long range Bi/Lu disorder and local WO6 octahedron distortions in the structure.

Lu and Duque in Destiny laboratory with musical keyboard

NASA Image and Video Library

2003-10-26

ISS007-E-18044 (26 October 2003) --- Astronaut Edward T. Lu (at musical keyboard), Expedition 7 NASA ISS science officer and flight engineer, and European Space Agency (ESA) astronaut Pedro Duque of Spain share a light moment during off-shift time in the Destiny laboratory on the International Space Station (ISS).

Surprising luminescent properties of the polyphosphates Ln(PO3)3:Eu (Ln = Y, Gd, Lu).

PubMed

Höppe, Henning A; Kazmierczak, Karolina; Kacprzak, Sylwia; Schellenberg, Inga; Pöttgen, Rainer

2011-10-21

The optical emission properties of the lanthanoid catena-polyphosphates Ln(PO(3))(3) (Ln = Y, Gd, Lu) doped with europium were investigated. Incommensurately modulated β-Y(PO(3))(3):Eu (super space group Cc (0|0.364|0)0) and Gd(PO(3))(3):Eu (space group I2/a) show the usual emission characteristics of Eu(3+), while in Lu(PO(3))(3):Eu (space group Cc) the europium is unprecedentedly partially reduced to the divalent state, as proven by both a broad emission band at 406 nm excited at 279 nm and an EPR spectroscopic investigation. (151)Eu-Mössbauer spectroscopy showed that only a very small part of the europium is reduced in Lu(PO(3))(3):Eu. An explanation for this unusual behaviour is given. This journal is © The Royal Society of Chemistry 2011

High beam quality of a Q-switched 2-µm Tm,Ho:LuVO4 laser

NASA Astrophysics Data System (ADS)

Wang, Wei; Yang, Xining; Shen, Yingjie; Li, Linjun; Zhou, Long; Yang, Yuqiang; Bai, Yunfeng; Xie, Wenqiang; Ye, Guangchao; Yu, Xiaoyang

2018-05-01

A diode-end-pumped 2.05-µm Q-switched Tm,Ho:LuVO4 laser is reported in this paper. The cryogenic Tm3+ (5.0 at.%),Ho3+ (0.5 at.%):LuVO4 crystal was pumped by an 800-nm laser diode. At a pulse repetition frequency of 10 kHz, the maximum average output power of 3.77 W was achieved at 77 K when an incident pump power of 14.7 W was used. The slope efficiency and optical-optical conversion efficiency were 28.3 and 25.6%, respectively. The maximum per pulse energy was 2.54 mJ for a pulse duration of 69.9 ns. The beam quality factor Mx 2 was approximately 1.17 and My 2 was approximately 1.01 for the Tm,Ho:LuVO4 laser.

[177Lu]-PSMA-617 radionuclide treatment in patients with metastatic castration-resistant prostate cancer (LuPSMA trial): a single-centre, single-arm, phase 2 study.

PubMed

Hofman, Michael S; Violet, John; Hicks, Rodney J; Ferdinandus, Justin; Thang, Sue Ping; Akhurst, Tim; Iravani, Amir; Kong, Grace; Ravi Kumar, Aravind; Murphy, Declan G; Eu, Peter; Jackson, Price; Scalzo, Mark; Williams, Scott G; Sandhu, Shahneen

2018-06-01

Progressive metastatic castration-resistant prostate cancer is a highly lethal disorder and new effective therapeutic agents that improve patient outcomes are urgently needed. Lutetium-177 [ 177 Lu]-PSMA-617, a radiolabelled small molecule, binds with high affinity to prostate-specific membrane antigen (PSMA) enabling beta particle therapy targeted to metastatic castration-resistant prostate cancer. We aimed to investigate the safety, efficacy, and effect on quality of life of [ 177 Lu]-PSMA-617 in men with metastatic castration-resistant prostate cancer who progressed after standard treatments. In this single-arm, single-centre, phase 2 trial, we recruited men (aged 18 years and older) with metastatic castration-resistant prostate cancer and progressive disease after standard treatments, including taxane-based chemotherapy and second-generation anti-androgens, from the Peter MacCallum Cancer Centre, Melbourne, VIC, Australia. Patients underwent a screening PSMA and FDG-PET/CT to confirm high PSMA-expression. Eligible patients had progressive disease defined by imaging (according to Response Evaluation Criteria In Solid Tumours [RECIST] or bone scan) or new pain in an area of radiographically evident disease, and were required to have an Eastern Cooperative Oncology Group (ECOG) performance status score of 2 or lower. Eligible patients received up to four cycles of intravenous [ 177 Lu]-PSMA-617, at six weekly intervals. The primary endpoint was PSA response according to Prostate Cancer Clinical Trial Working Group criteria defined as a greater than 50% PSA decline from baseline and toxicity according to CTCAE. Additional primary endpoints were imaging responses (as measured by bone scan, CT, PSMA, and FDG PET/CT) and quality of life (assessed with the EORTC-Q30 and Brief Pain Inventory-Short Form questionnaires), all measured up to 3 months post completion of treatment. This trial is registered with the Australian New Zealand Clinical Trials Registry, number

Origin of the colossal dielectric permittivity and magnetocapacitance in LuFe2O4

NASA Astrophysics Data System (ADS)

Ren, P.; Yang, Z.; Zhu, W. G.; Huan, C. H. A.; Wang, L.

2011-04-01

We report the detailed study on the colossal dielectric constant and magnetocapacitance of LuFe2O4. The experimental results indicate that the large dielectric constant of LuFe2O4 is originated from two sources, (1) Maxwell Wagner-type contributions of depletion layers at grain boundaries and the interfaces between sample and contacts, (2) AC response of the constant phase element in the bulk. A detailed equivalent circuit analysis indicates that the conductivity variation can be responsible for the observed "magnetocapacitance."

Oxygen miscibility gap and spin glass formation in the pyrochlore Lu{sub 2}Mo{sub 2}O{sub 7}

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

Clark, L.; Ritter, C.; Harrison, A.

2013-07-15

Rare earth (R) molybdate pyrochlores, R{sub 2}Mo{sub 2}O{sub 7}, are of interest as frustrated magnets. Polycrystalline samples of Lu{sub 2}Mo{sub 2}O{sub 7−x} prepared at 1600 °C display a coexistence of cubic pyrochlore phases. Rietveld fits to powder neutron diffraction data and chemical analyses show that the miscibility gap is between a stoichiometric x=0 and an oxygen-deficient x≈0.4 phase. Lu{sub 2}Mo{sub 2}O{sub 7} behaves as a spin glass material, with a divergence of field cooled and zero field cooled DC magnetic susceptibilities at a spin freezing temperature T{sub f}=16 K, that varies with frequency in AC measurements following a Vogel–Fulcher law.more » Lu{sub 2}Mo{sub 2}O{sub 6.6} is more highly frustrated spin glass and has T{sub f}=20 K. - Graphical abstract: The cubic Lu{sub 2}Mo{sub 2}O{sub 7−x} system exhibits a miscibility gap between coexisting pyrochlore phases at 1600 °C. Neutron powder diffraction refinement and chemical analysis shows that the gap separates stoichiometric x=0 and oxygen-deficient x≈0.4 phases. Lu{sub 2}Mo{sub 2}O{sub 7−x} has a frustrated spin glass ground state that is sensitive to the oxygen content. - Highlights: • The cubic Lu{sub 2}Mo{sub 2}O{sub 7−x} system has a miscibility gap between coexisting pyrochlore phases at 1600 °C. • Neutron powder diffraction shows that the gap separates x=0 and oxygen-deficient x≈0.4 phases. • Lu{sub 2}Mo{sub 2}O{sub 7−x} has a frustrated spin glass ground state that is sensitive to the oxygen content.« less

A double-blind, randomized, placebo-controlled, active reference study of Lu AA21004 in patients with major depressive disorder

PubMed Central

Alvarez, Enric; Perez, Victor; Dragheim, Marianne; Loft, Henrik; Artigas, Francesc

2012-01-01

The efficacy, safety, and tolerability of Lu AA21004 vs. placebo using venlafaxine XR as active reference in patients with DSM-IV-TR major depressive disorder (MDD) were evaluated. Lu AA21004 is a novel antidepressant that is a 5-HT3 and 5-HT7 receptor antagonist, 5-HT1A receptor agonist, 5-HT1B receptor partial agonist and inhibitor of the 5-HT transporter in recombinant cell lines. In this 6-wk, multi-site study, 429 patients were randomly assigned (1:1:1:1) to 5 or 10 mg Lu AA21004, placebo or 225 mg venlafaxine XR. All patients had a baseline Montgomery–Åsberg Depression Rating Scale (MADRS) total score ⩾30. The primary efficacy analysis was based on the MADRS total score adjusting for multiplicity using a hierarchical testing procedure starting with the highest dose vs. placebo. Lu AA21004 was statistically significantly superior to placebo (n=105) in mean change from baseline in MADRS total score at week 6 (p<0.0001, last observation carried forward), with a mean treatment difference vs. placebo of 5.9 (5 mg, n=108), and 5.7 (10 mg, n=100) points. Venlafaxine XR (n=112) was also significantly superior to placebo at week 6 (p<0.0001). In total, 30 patients withdrew due to adverse events (AEs) – placebo: four (4%); 5 mg Lu AA21004: three (3%); 10 mg Lu AA21004: seven (7%); and venlafaxine: 16 (14%). The most common AEs were nausea, headache, hyperhidrosis, and dry mouth. No clinically relevant changes over time were seen in the clinical laboratory results, vital signs, weight, or ECG parameters. In this study, treatment with 5 mg and 10 mg Lu AA21004 for 6 wk was efficacious and well tolerated in patients with MDD. PMID:21767441

Charge ordering, ferroelectric, and magnetic domains in LuFe{sub 2}O{sub 4} observed by scanning probe microscopy

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

Yang, I. K.; Jeong, Y. H., E-mail: yhj@postech.ac.kr; Kim, Jeehoon

2015-04-13

LuFe{sub 2}O{sub 4} is a multiferroic system which exhibits charge order, ferroelectricity, and ferrimagnetism simultaneously below ∼230 K. The ferroelectric/charge order domains of LuFe{sub 2}O{sub 4} are imaged with both piezoresponse force microscopy (PFM) and electrostatic force microscopy (EFM), while the magnetic domains are characterized by magnetic force microscopy (MFM). Comparison of PFM and EFM results suggests that the proposed ferroelectricity in LuFe{sub 2}O{sub 4} is not of usual displacive type but of electronic origin. Simultaneous characterization of ferroelectric/charge order and magnetic domains by EFM and MFM, respectively, on the same surface of LuFe{sub 2}O{sub 4} reveals that both domains havemore » irregular patterns of similar shape, but the length scales are quite different. The domain size is approximately 100 nm for the ferroelectric domains, while the magnetic domain size is much larger and gets as large as 1 μm. We also demonstrate that the origin of the formation of irregular domains in LuFe{sub 2}O{sub 4} is not extrinsic but intrinsic.« less

In Vitro comparison of 213Bi- and 177Lu-radiation for peptide receptor radionuclide therapy.

PubMed

Chan, Ho Sze; de Blois, Erik; Morgenstern, Alfred; Bruchertseifer, Frank; de Jong, Marion; Breeman, Wouter; Konijnenberg, Mark

2017-01-01

Absorbed doses for α-emitters are different from those for β-emitters, as the high linear energy transfer (LET) nature of α-particles results in a very dense energy deposition over a relatively short path length near the point of emission. This highly localized and therefore high energy deposition can lead to enhanced cell-killing effects at absorbed doses that are non-lethal in low-LET type of exposure. Affinities of DOTA-DPhe1-Tyr3-octreotate (DOTATATE), 115In-DOTATATE, 175Lu-DOTATATE and 209Bi-DOTATATE were determined in the K562-SST2 cell line. Two other cell lines were used for radiation response assessment; BON and CA20948, with a low and high expression of somatostatin receptors, respectively. Cellular uptake kinetics of 111In-DOTATATE were determined in CA20948 cells. CA20948 and BON were irradiated with 137Cs, 177Lu-DTPA, 177Lu-DOTATATE, 213Bi-DTPA and 213Bi-DOTATATE. Absorbed doses were calculated using the MIRDcell dosimetry method for the specific binding and a Monte Carlo model of a cylindrical 6-well plate geometry for the exposure by the radioactive incubation medium. Absorbed doses were compared to conventional irradiation of cells with 137Cs and the relative biological effect (RBE) at 10% survival was calculated. IC50 of (labelled) DOTATATE was in the nM range. Absorbed doses up to 7 Gy were obtained by 5.2 MBq 213Bi-DOTATATE, in majority the dose was caused by α-particle radiation. Cellular internalization determined with 111In-DOTATATE showed a linear relation with incubation time. Cell survival after exposure of 213Bi-DTPA and 213Bi-DOTATATE to BON or CA20948 cells showed a linear-exponential relation with the absorbed dose, confirming the high LET character of 213Bi. The survival of CA20948 after exposure to 177Lu-DOTATATE and the reference 137Cs irradiation showed the typical curvature of the linear-quadratic model. 10% Cell survival of CA20948 was reached at 3 Gy with 213Bi-DOTATATE, a factor 6 lower than the 18 Gy found for 177Lu

In Vitro comparison of 213Bi- and 177Lu-radiation for peptide receptor radionuclide therapy

PubMed Central

de Blois, Erik; Morgenstern, Alfred; Bruchertseifer, Frank; de Jong, Marion; Breeman, Wouter; Konijnenberg, Mark

2017-01-01

Background Absorbed doses for α-emitters are different from those for β-emitters, as the high linear energy transfer (LET) nature of α-particles results in a very dense energy deposition over a relatively short path length near the point of emission. This highly localized and therefore high energy deposition can lead to enhanced cell-killing effects at absorbed doses that are non-lethal in low-LET type of exposure. Affinities of DOTA-DPhe1-Tyr3-octreotate (DOTATATE), 115In-DOTATATE, 175Lu-DOTATATE and 209Bi-DOTATATE were determined in the K562-SST2 cell line. Two other cell lines were used for radiation response assessment; BON and CA20948, with a low and high expression of somatostatin receptors, respectively. Cellular uptake kinetics of 111In-DOTATATE were determined in CA20948 cells. CA20948 and BON were irradiated with 137Cs, 177Lu-DTPA, 177Lu-DOTATATE, 213Bi-DTPA and 213Bi-DOTATATE. Absorbed doses were calculated using the MIRDcell dosimetry method for the specific binding and a Monte Carlo model of a cylindrical 6-well plate geometry for the exposure by the radioactive incubation medium. Absorbed doses were compared to conventional irradiation of cells with 137Cs and the relative biological effect (RBE) at 10% survival was calculated. Results IC50 of (labelled) DOTATATE was in the nM range. Absorbed doses up to 7 Gy were obtained by 5.2 MBq 213Bi-DOTATATE, in majority the dose was caused by α-particle radiation. Cellular internalization determined with 111In-DOTATATE showed a linear relation with incubation time. Cell survival after exposure of 213Bi-DTPA and 213Bi-DOTATATE to BON or CA20948 cells showed a linear-exponential relation with the absorbed dose, confirming the high LET character of 213Bi. The survival of CA20948 after exposure to 177Lu-DOTATATE and the reference 137Cs irradiation showed the typical curvature of the linear-quadratic model. 10% Cell survival of CA20948 was reached at 3 Gy with 213Bi-DOTATATE, a factor 6 lower than the 18 Gy

Lu1-xI3:Cex--A Scintillator for gamma ray spectroscopy and time-of-flight PET

DOEpatents

Shah, Kanai S [Newton, MA

2009-03-17

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

Lu-Hf and Sm-Nd Isotopic Studies of Shergottites and Nakhlites: Implications for Martian Mantle Sources

NASA Technical Reports Server (NTRS)

Debaille, V.; Yin, Q.-Z.; Brandon, A. D.; Jacobsen, B.; Treiman, A. H.

2007-01-01

We present a new Lu-Hf and Sm-Nd isotope systematics study of four enriched shergottites (Zagami, Shergotty, NWA856 and Los Angeles), and three nakhlites (Nakhla, MIL03346 and Yamato 000593) in order to further understand processes occurring during the early differentiation of Mars and the crystallization of its magma ocean. Two fractions of the terrestrial petrological analogue of nakhlites, the Archaean Theo's flow (Ontario, Canada) were also measured. The coupling of Nd and Hf isotopes provide direct insights on the mineralogy of the melt sources. In contrast to Sm/Nd, Lu/Hf ratios can be very large in minerals such as garnet. Selective partial melting of garnet bearing mantle sources can therefore lead to characteristic Lu/Hf signatures that can be recognized with Hf-176/Hf-177Hf ratios.

Photodynamic therapy trials with lutetium texaphyrin (Lu-Tex) in patients with locally recurrent breast cancer

NASA Astrophysics Data System (ADS)

Renschler, Markus F.; Yuen, Alan R.; Panella, Timothy J.; Wieman, Thomas J.; Dougherty, Shona; Esserman, Laura; Panjehpour, Masoud; Taber, Scott W.; Fingar, Victor H.; Lowe, Elizabeth; Engel, Julie S.; Lum, Bert; Woodburn, Kathryn W.; Cheong, Wai-Fung; Miller, Richard A.

1998-05-01

Photodynamic therapy (PDT) of locally recurrent breast cancer has been limited to treatment of small lesions because of non- selective necrosis of adjacent normal tissues in the treatment field. Lutetium Texaphyrin (PCI-0123, Lu-Tex) is a photosensitizer with improved tumor localization that is activated by 732 nm light, which can penetrate through larger tumors. We have evaluated Lu-Tex in a Phase I trial and in an ongoing Phase II trial in women with locally recurrent breast cancer with large tumors who have failed radiation therapy. Patients received Lu-Tex intravenously by rapid infusion 3 hours before illumination of cutaneous or subcutaneous lesions. In Phase I, Lu-Tex doses were escalated from 0.6 to 7.2 mg/kg in 7 cohorts. Sixteen patients with locally recurrent breast cancer lesions were treated. Dose limiting toxicities above 5.5 mg/kg were pain in the treatment field during therapy, and dysesthesias in light exposed areas. No necrosis of normal tissues in the treated field was noticed. Responses were observed in 60% of evaluable patients [n equals 15, 27% complete remission (CR), 33% partial remission (PR)], with 63% of lesions responding (n equals 73: 45% CR, 18% PR). In Phase II, 25 patients have been studied to date, receiving two treatments ranging from 1.0 to 3.0 mg/kg at a 21 day interval. Treatment fields up to 480 cm2 in size were treated successfully and activity has been observed. Patients have experienced pain at the treatment site but no tissue necrosis. These studies demonstrate the feasibility of Lu-Tex PDT to large chest wall areas in women who have failed radiation therapy for the treatment of locally recurrent breast cancer. Treatment conditions are currently being optimized in the ongoing Phase II trials.

Evaluation of SuperLU on multicore architectures

NASA Astrophysics Data System (ADS)

Li, X. S.

2008-07-01

The Chip Multiprocessor (CMP) will be the basic building block for computer systems ranging from laptops to supercomputers. New software developments at all levels are needed to fully utilize these systems. In this work, we evaluate performance of different high-performance sparse LU factorization and triangular solution algorithms on several representative multicore machines. We included both Pthreads and MPI implementations in this study and found that the Pthreads implementation consistently delivers good performance and that a left-looking algorithm is usually superior.

Influence of Lu2O3 on electrical and microstructural properties of CaCu3Ti4O12 ceramics

NASA Astrophysics Data System (ADS)

Xu, Dong; Wang, Biao; Lin, Yuanhua; Jiao, Lei; Yuan, Hongming; Zhao, Guoping; Cheng, Xiaonong

2012-07-01

In this work, the influence of Lu2O3 doped on the dielectric and electrical properties of CaCu3Ti4O12 was reported. Lu2O3-doped CCTO was prepared by a conventional solid state technique using CuO, TiO2, and CaCO3 as starting materials. The samples were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM); dielectric measurements were measured in the 102 Hz-107 Hz frequency range at room temperature; and the nonlinear behavior of all samples was measured. The doping of Lu2O3 resulted in an increase in the dielectric constant of CCTO, but decreased the stability of the frequency dependence. Increasing concentrations of Lu2O3 resulted in decreasing nonlinear coefficients.

Lu-Hf total-rock age for the Amîtsoq gneisses, West Greenland

USGS Publications Warehouse

Pettingill, H.S.; Patchett, P.J.

1981-01-01

Lu-Hf total-rock data for the Amîtsoq gneisses of West Greenland yield an age of 3.55±0.22Gy(2σ), based on the decay constant λ176Lu=1.96×10−11y−1, and an initial176Hf/177Hf ratio of 0.280482±33. The result is in good agreement with Rb-Sr total-rock and U-Pb zircon ages. In spite of severe metamorphism of the area at 2.9 Gy, zircons from two of the samples have remained on the total-rock line, and define points close to the initial Hf ratio. The initial176Hf/177Hf lies close to a chondritic Hf isotopic evolution curve from 4.55 Gy to present. This is consistent with the igneous precursors to the Amîtsoq gneisses having been derived from the mantle at or shortly before 3.6 Gy. Anomalous relationships between Hf concentration and the176Lu/177Hf ratio may suggest that trace element abundances in the Amîtsoq gneisses are partly controlled by processes related to metamorphism.

Shape evolution with angular momentum in Lu isotopes

NASA Astrophysics Data System (ADS)

Kardan, Azam; Sayyah, Sepideh

2016-06-01

The nuclear potential energies of Lu isotopes with neutron number N = 90 - 98 up to high spins are computed within the framework of the unpaired cranked Nilsson-Strutinsky method. The potential and the macroscopic Lublin-Strasbourg drop (LSD) energy-surface diagrams are analyzed in terms of quadrupole deformation and triaxiality parameter. The shape evolution of these isotopes with respect to angular momentum, as well as the neutron number is studied.

SAFETEA-LU 1808 : CMAQ, evaluation and assessment, phase I, final report.

DOT National Transportation Integrated Search

2008-10-01

In SAFETEA-LU Section 1808, Congress required the U.S. Department of Transportation, in consultation with the Environmental Protection Agency (EPA), to evaluate and assess the direct and indirect impacts of CMAQ-funded projects on air quality and con...

SAFETEA-LU 1808 : CMAQ, evaluation and assessment, phase II, final report.

DOT National Transportation Integrated Search

2009-07-01

In SAFETEA-LU Section 1808, Congress required the U.S. Department of Transportation, in consultation with the Environmental Protection Agency (EPA), to evaluate and assess the direct and indirect impacts of CMAQ-funded projects on air quality and con...

Lu-177 DOTATATE dosimetry for neuroendocrine tumor: single center experience

NASA Astrophysics Data System (ADS)

Said, MA; Masud, MA; Zaini, MZ; Salleh, RA; Lee, BN; Zainon, R.

2017-05-01

Lu-177 labelled with DOTATE is widely acceptable to treat Neuroendocrine Tumor (NET) disease and it better improvement of quality of patients’ life since few years ago. However, the radionuclide toxicity becomes the main limitation of the (NET) treatment. Therefore, we performed a pilot study aimed to estimate radiation absorbed doses to dose-limiting organs to develop a systemic therapy with Lu-177 in NET patients. In this study, five set of planar whole body images was acquired every 0.5 hour, 4 hours, 24 hours, 48 hours and 72 hours after Lu-177 administrations. The planar image acquisition was done using Philip Brightview X with Medium Energy General Purpose Collimator (MEGP) collimator. All patients’ images in Conjugate View (CV) format were transferred into PMOD 3.7 Software for Region of Interest (ROI) analysis. The ROI were drawn at selected organs such as kidneys, liver, spleen and bladder. This study found that the mean absorbed dose for kidneys 0.62 ± 0.26 Gy/GBq, liver 0.63 ± 0.28 Gy/GBq, spleen 0.83 ± 0.73 Gy/GBq and bladder 0.14 ± 0.07 Gy/GBq. The radionuclide kinetic for the whole body 99.7 ± 0.1 percent at 0.5 hours, 79.5 ± 10.7 percent at 4 hours, 56.6 ± 10.3 percent at 24 hours, 43.2 ± 7.9 percent at 48 hours and 37.1 ± 9.0 percent at 72 hours. This study verifies that this planar quantitative method able to determine organ at risk and the result line with other published data.

High treatment efficacy by dual targeting of Burkitt's lymphoma xenografted mice with a (177)Lu-based CD22-specific radioimmunoconjugate and rituximab.

PubMed

Weber, Tobias; Bötticher, Benedikt; Mier, Walter; Sauter, Max; Krämer, Susanne; Leotta, Karin; Keller, Armin; Schlegelmilch, Anne; Grosse-Hovest, Ludger; Jäger, Dirk; Haberkorn, Uwe; Arndt, Michaela A E; Krauss, Jürgen

2016-03-01

Dual-targeted therapy has been shown to be a promising treatment option in recurrent and/or refractory B-cell non-Hodgkin's lymphoma (B-NHL). We generated radioimmunoconjugates (RICs) comprising either a novel humanized anti-CD22 monoclonal antibody, huRFB4, or rituximab, and the low-energy β-emitter (177)Lu. Both RICs were evaluated as single agents in a human Burkitt's lymphoma xenograft mouse model. To increase the therapeutic efficacy of the anti-CD22 RIC, combination therapy with unlabelled anti-CD20 rituximab was explored. The binding activity of CHX-A″-DTPA-conjugated antibodies to target cells was analysed by flow cytometry. To assess tumour targeting of (177)Lu-labelled antibodies, in vivo biodistribution experiments were performed. For radioimmunotherapy (RIT) studies, non-obese diabetic recombination activating gene-1 (NOD-Rag1 (null) ) interleukin-2 receptor common gamma chain (IL2rγ (null) ) null mice (NRG mice) were xenografted subcutaneously with Raji Burkitt's lymphoma cells. (177)Lu-conjugated antibodies were administered at a single dose of 9.5 MBq per mouse. For dual-targeted therapy, rituximab was injected at weekly intervals (0.5 - 1.0 mg). Tumour accumulation of RICs was monitored by planar scintigraphy. Conjugation of CHX-A"-DTPA resulted in highly stable RICs with excellent antigen-binding properties. Biodistribution experiments revealed higher tumour uptake of the (177)Lu-labelled anti-CD22 IgG than of (177)Lu-labelled rituximab. Treatment with (177)Lu-conjugated huRFB4 resulted in increased tumour growth inhibition and significantly longer survival than treatment with (177)Lu-conjugated rituximab. The therapeutic efficacy of the anti-CD22 RIC could be markedly enhanced by combination with unlabelled rituximab. These findings suggest that dual targeting with (177)Lu-based CD22-specific RIT in combination with rituximab is a promising new treatment option for refractory B-NHL.

Synthesis and Photoluminescent Properties of Nanorod Bundle Ln4O(OH)9NO3:Eu(Ln = Y, Lu) Prepared by Hydrothermal Method.

PubMed

Li, Ling; Noh, Hyeon Mi; Liu, Xiaoguang; Moon, Byung Kee; Choi, Byung Chun; Jeong, Jung Hyun

2015-07-01

Well-crystallized nanorod bundles Ln4O(OH)9NO3:1%Eu(Ln = Y, Lu) have been successfully prepared by hydrothermal method. The crystalline phase, size and optical properties were characterized using powder X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), infrared (IR) spectrograph and photoluminescent (PL) spectra. Site occupations of Eu3+ in crystals Ln4O(OH)9NO3:Eu(Ln = Y, Lu) were discussed based on excitation spectra and the empirical relationship formula between the charge transfer (CT) energy and the environmental factor. The emission spectra exhibited that the strongest emission peaks with an excitation wavelength of 395 nm were at 617 and 626 nm in crystal Lu4O(OH)9NO3:1%Eu and Y4O(OH)9NO3:1%Eu, respectively, both of which come from 5D0-7F2 transition of the Eu3+ ions. The broad excitation peaks at about 254 and 255 nm were found when monitored at 617 and 628 nm in crystal Lu4O(OH)9NO3:1%Eu and Y4O(OH)9NO3:1%Eu, respectively, which were due to O-Eu CT transition. Based on the dielectric theory of complex crystal, the CT bands at about 254 and 255 nm in Ln4O(OH)9NO3:1%Eu(Ln = Y, Lu) were assigned to the transition of O-Eu at Ln3(Ln = Y, Lu) site, from which we can conclude that Eu3+ ions occupied the site of Ln3(Ln = Y, Lu) in crystal Ln4O(OH)9NO3:1%Eu(Ln = Y, Lu). It put forward a new route to investigate site occupation of luminescent center ions in rare earth doped complex inorganic luminescence materials.

Safety, Pharmacokinetics and Dosimetry of a Long-Acting Radiolabeled Somatostatin Analogue 177Lu-DOTA-EB-TATE in Patients with Advanced Metastatic Neuroendocrine Tumors.

PubMed

Zhang, Jingjing; Wang, Hao; Jacobson Weiss, Orit; Cheng, Yuejuan; Niu, Gang; Li, Fang; Bai, Chunmei; Zhu, Zhaohui; Chen, Xiaoyuan

2018-04-13

Radiolabeled somatostatin analogue therapy has become an established treatment method for patients with well to moderately differentiated unresectable or metastatic neuroendocrine tumors (NETs). The most frequently used somatostatin analogues in clinical practice are octreotide and octreotate. However, both peptides showed suboptimal retention within tumors. The aim of this first-in-human study is to explore the safety and dosimetry of a long-acting radiolabeled somatostatin analogue, lutetium-177-1, 4, 7, 10-tetra-azacyclododecane-1, 4, 7, 10-tetraacetic acid-Evans blue-octreotate ( 177 Lu-DOTA-EB-TATE). Methods: Eight patients (6 males and 2 females; age range, 27-61 y) with advanced metastatic neuroendocrine tumors were recruited. Five patients received a single dose 0.35-0.70 GBq (9.5-18.9 mCi) of 177 Lu-DOTA-EB-TATE and underwent serial whole body planar and single-photon emission computed tomography-computed tomography (SPECT-CT) scans at 2, 24, 72, 120 and 168 h after injection. The other 3 patients received intravenous injection of 0.28-0.41 GBq (7.5-11.1 mCi) of 177 Lu-DOTATATE for the same imaging acquisition procedures at 1, 3, 4, 24 and 72 h after injection. The dosimetry was calculated using the OLINDA/EXM 1.1 software. Results: Administration of 177 Lu-DOTA-EB-TATE was well tolerated, with no adverse symptoms being noticed or reported in any of the patients. Compared with 177 Lu-DOTATATE, 177 Lu-DOTA-EB-TATE showed extended circulation in the blood and achieved 7.9-fold increase of tumor dose delivery. The total body effective doses were 0.205 ± 0.161 mSv/MBq for 177 Lu-DOTA-EB-TATE and 0.174 ± 0.072 mSv/MBq for 177 Lu-DOTATATE. Significant dose delivery increases to the kidneys and bone marrow were also observed in patients receiving 177 Lu-DOTA-EB-TATE than those receiving 177 Lu-DOTATATE (3.2 and 18.2-fold, respectively). Conclusion: By introducing an albumin binding moiety, 177 Lu-DOTA-EB-TATE showed remarkably higher uptake and retention in NET

Flashlamp-pumped Ho:Tm:Cr:LuAG laser

NASA Technical Reports Server (NTRS)

Jani, Mahendra G. (Inventor); Barnes, Norman P. (Inventor); Murray, Keith E. (Inventor); Kokta, Milan R. (Inventor)

1997-01-01

A room temperature solid-state laser is provided. A laser crystal is disposed in a laser cavity. The laser crystal has a LuAG host material doped with a concentration of about 0.35% Ho ions, about 5.57% Tm ions and at least about 1.01% Cr ions. A broadband energizing source such as a flashlamp is disposed transversely to the laser crystal to energize the Ho ions, Tm ions and Cr ions.

Characterization of [11C]Lu AE92686 as a PET radioligand for phosphodiesterase 10A in the nonhuman primate brain.

PubMed

Yang, Kai-Chun; Stepanov, Vladimir; Amini, Nahid; Martinsson, Stefan; Takano, Akihiro; Nielsen, Jacob; Bundgaard, Christoffer; Bang-Andersen, Benny; Grimwood, Sarah; Halldin, Christer; Farde, Lars; Finnema, Sjoerd J

2017-02-01

[ 11 C]Lu AE92686 is a positron emission tomography (PET) radioligand that has recently been validated for examining phosphodiesterase 10A (PDE10A) in the human striatum. [ 11 C]Lu AE92686 has high affinity for PDE10A (IC 50  = 0.39 nM) and may also be suitable for examination of the substantia nigra, a region with low density of PDE10A. Here, we report characterization of regional [ 11 C]Lu AE92686 binding to PDE10A in the nonhuman primate (NHP) brain. A total of 11 PET measurements, seven baseline and four following pretreatment with unlabeled Lu AE92686 or the structurally unrelated PDE10A inhibitor MP-10, were performed in five NHPs using a high resolution research tomograph (HRRT). [ 11 C]Lu AE92686 binding was quantified using a radiometabolite-corrected arterial input function and compartmental and graphical modeling approaches. Regional time-activity curves were best described with the two-tissue compartment model (2TCM). However, the distribution volume (V T ) values for all regions were obtained by the Logan plot analysis, as reliable cerebellar V T values could not be derived by the 2TCM. For cerebellum, a proposed reference region, V T values increased by ∼30 % with increasing PET measurement duration from 63 to 123 min, while V T values in target regions remained stable. Both pretreatment drugs significantly decreased [ 11 C]Lu AE92686 binding in target regions, while no significant effect on cerebellum was observed. Binding potential (BP ND ) values, derived with the simplified reference tissue model (SRTM), were 13-17 in putamen and 3-5 in substantia nigra and correlated well to values from the Logan plot analysis. The method proposed for quantification of [ 11 C]Lu AE92686 binding in applied studies in NHP is based on 63 min PET data and SRTM with cerebellum as a reference region. The study supports that [ 11 C]Lu AE92686 can be used for PET examinations of PDE10A binding also in substantia nigra.

Immuno-PET Imaging and Radioimmunotherapy of 64Cu-/177Lu-Labeled Anti-EGFR Antibody in Esophageal Squamous Cell Carcinoma Model.

PubMed

Song, In Ho; Lee, Tae Sup; Park, Yong Serk; Lee, Jin Sook; Lee, Byung Chul; Moon, Byung Seok; An, Gwang Il; Lee, Hae Won; Kim, Kwang Il; Lee, Yong Jin; Kang, Joo Hyun; Lim, Sang Moo

2016-07-01

Immuno-PET provides valuable information about tumor location, phenotype, susceptibility to therapy, and treatment response, especially to targeted radioimmunotherapy. In this study, we prepared antiepidermal growth factor receptor (EGFR) antibody via identical chelator, 3,6,9,15-tetraazabicyclo[9.3.1]-pentadeca-1(15),11,13-trience-3,6,9,-triacetic acid (PCTA), labeled with (64)Cu or (177)Lu to evaluate the EGFR expression levels using immuno-PET and the feasibility of radioimmunotherapy in an esophageal squamous cell carcinoma (ESCC) model. Cetuximab was conjugated with p-SCN-Bn-PCTA and radiolabeled with (64)Cu or (177)Lu. In vitro EGFR expression levels were determined and compared using flow cytometry and cell binding assay. In vivo EGFR expression levels were evaluated via immuno-PET imaging of (64)Cu-cetuximab and biodistribution analysis. Micro-SPECT/CT imaging, biodistribution, and radioimmunotherapy studies of (177)Lu-cetuximab were performed in the ESCC model. Therapeutic responses were monitored using (18)F-FDG PET and immunohistochemical staining. (64)Cu- or (177)Lu-labeled antibodies showed high radiolabeling yield (>98%), stability (>90%), and favorable immunoreactivity. In vitro EGFR status measured by cell binding assay was correlated with the flow cytometry data. Immuno-PET, micro-SPECT/CT, and biodistribution demonstrated specific uptake in ESCC tumors depending on the EGFR expression levels. Tumor accumulation of (64)Cu- and (177)Lu-cetuximab was peaked at 48 and 120 h, respectively. Radioimmunotherapy with (177)Lu-cetuximab showed significant inhibition of tumor growth (P < 0.01) and marked reduction of (18)F-FDG SUV compared with that of control (P < 0.05). Terminal deoxynucleotidyl transferase dUTP nick-end labeling positivity and Ki-67 staining indices increased and decreased, respectively, in the radioimmunotherapy group compared with other groups (P < 0.01). (64)Cu-cetuximab immuno-PET represented EGFR expression levels in ESCC tumors, and

Bulk Scale Formulation of Therapeutic Doses of Clinical Grade Ready-to-Use 177Lu-DOTA-TATE: The Intricate Radiochemistry Aspects.

PubMed

Mathur, Anupam; Prashant, Vrinda; Sakhare, Navin; Chakraborty, Sudipta; Vimalnath, K V; Mohan, Repaka Krishna; Arjun, Chanda; Karkhanis, Barkha; Seshan, Ravi; Basu, Sandip; Korde, Aruna; Banerjee, Sharmila; Dash, Ashutosh; Sachdev, Satbir Singh

2017-09-01

177 Lu-DOTA-TATE is a clinically useful and promising therapeutic radiopharmaceutical for peptide receptor radionuclide therapy of neuroendocrine tumors (NETs) overexpressing somatostatin receptors. Currently, the radiopharmaceutical is prepared in-house at nuclear medicine centers, thereby restricting its use to limited centers only. In this article, the authors describe systematic studies toward bulk scale formulation of "ready-to-use" 177 Lu-DOTA-TATE using medium specific activity 177 Lu (740-1110 GBq/mg) at a centralized radiopharmacy facility. In an optimized protocol, 177 Lu-DOTA-TATE synthesis was carried out by direct heating of 177 LuCl 3 (Sp. act. 740-1110 GBq/mg) with DOTA-TATE peptide (1.5-3.0 equivalents) in ammonium acetate buffer (0.2 M) containing 2,5-dihydroxy benzoic acid (gentisic acid). Thereafter, the crude labeled product was purified using a Sep-Pak ® C18 column and diluted with acetate buffer-gentisic acid (1.5% w/v) solution to final radioactive concentration of 740 MBq/mL. This was further sterilized and dispensed as 7.4 GBq patient dose/vial with 2 days postformulation calibration. A peptide/metal ratio of 1.5-3.0 is essential for complexation wherein radiolabeling yields >90% are obtained minimizing free 177 Lu waste. For formulation of 7.4 GBq patient dose (2 days postproduction), even specific activity of about 555 GBq/mg was found to be adequate for the radiometal. The ready-to-use 740 MBq/mL 177 Lu-DOTA-TATE formulation with gentisic acid (1.5% w/v) is observed to be safe for human use for more than 1 week (radiochemical purity >98%) from the day of production when stored at -70°C. However, the target specificity may get affected beyond 2 days as the total peptide content for 7.4 GBq dose may exceed the critical peptide limit of 300 μg. Patient treatment carried with several batches of present formulation in diseased NET patients exhibited desired distribution at the tumor and its metastatic site. A ready

Synthesis of novel branched β-NaLuF4: Yb/Er upconversion luminescence material and investigation of its optical properties

NASA Astrophysics Data System (ADS)

Ding, Yanli; Yang, Tonghui; Yin, Naiqiang; Shu, Fangjie; Zhao, Ying; Zhang, Xiaodan

2018-05-01

Branched β-NaLuF4: Yb/Er was synthesized using a simple hydrothermal method by controlling the NaF/Ln molar ratio. In contrast to the β-NaYF4: Yb/Er hexagonal disks, the branched β-NaLuF4: Yb/Er has stronger emission intensity. The integrated intensities of green and red emission bands were as 6.2 and 3.3 times as that of NaYF4, respectively. The branched β-NaLuF4: Yb/Er has the smaller unit cell volume, the higher absorption intensity around 980 nm and the lower crystal field symmetry than NaYF4, which made a significant contribution to the stronger upconversion (UC) fluorescence emissions. The results indicate that the branched β-NaLuF4: Yb/Er is an excellent UC luminescence material. The current research has a great potential in improving near-infrared conversion efficiency of solar cells.

Development of (177)Lu-DOTA-Dendrimer and Determination of Its Effect on Metal and Ion Levels in Tumor Tissue.

PubMed

Kovacs, Luciana; Tassano, Marcos; Cabrera, Mirel; Zamboni, Cibele B; Fernández, Marcelo; Anjos, Roberto M; Cabral, Pablo

2015-12-01

Dendrimers are synthetic nanomolecules with well-defined chemical structures. Different strategies have been used for radiolabeling dendrimers with different radioisotopes. In this study, the aim was to conjugate dendrimers with (177)Lu, to observe the in vivo behavior of the labeled compound and to measure the elementary changes in tumor tissue that could be caused by ionizing radiation. PAMAM G4 dendrimers conjugated with DOTA were labeled with (177)Lu. The radiolabeled compound was characterized and its stability was evaluated by reverse phase high performance liquid chromatography. Radiolabeling yield was >98% and stable for 24 hours. Biodistribution studies of (177)Lu-DOTA-dendrimers in C57BL/6 melanoma-bearing mice showed blood clearance with hepatic and renal depuration and tumor uptake. The concentrations of Br, Ca, Cl, Fe, K, Mg, Na, Rb, S, and Zn were determined in tumor tissues of C57BL/6 mice treated with (177)Lu-DOTA-dendrimers and in untreated mice. The results showed decreased concentrations of Br (62%), Ca (24%), Cl (51%), K (12%) and Na (60%) and increased concentrations of Fe (8%), Mg (28%), Rb (100%), S (6%) and Zn (4%) in tumor tissues of mice treated with (177)Lu-DOTA-dendrimers. These data may be useful to evaluate changes in tumor tissues as indicators of damage that could be caused by ionizing radiation.

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

DOEpatents

Shah, Kanai S [Newton, MA

2008-02-12

The present invention includes very fast scintillator materials including lutetium iodide doped with Cerium (Lu.sub.1-xI.sub.3:Ce.sub.x; LuI.sub.3:Ce). The LuI.sub.3 scintillator material has surprisingly good characteristics including high light output, high gamma-ray stopping efficiency, fast response, low cost, good proportionality, and minimal afterglow that the material is useful for gamma-ray spectroscopy, medical imaging, nuclear and high energy physics research, diffraction, non-destructive testing, nuclear treaty verification and safeguards, and geological exploration.

The in vivo disposition and in vitro transmembrane transport of two model radiometabolites of DOTA-conjugated receptor-specific peptides labelled with (177) Lu.

PubMed

Volková, Marie; Mandíková, Jana; Bárta, Pavel; Navrátilová, Lucie; Lázníčková, Alice; Trejtnar, František

2015-01-01

In vivo metabolism of the radiolabelled receptor-specific peptides has been described; however, information regarding the pharmacokinetic behaviour of the degradation products within the body is very scarce. The present study was designed to obtain new knowledge on the disposition and elimination of low-molecular radiometabolites of receptor-specific peptides in the organism and to reveal the potential involvement of selected membrane transport mechanisms in the cellular uptake of radiometabolites, especially in the kidney. The study compared pharmacokinetics of two radiometabolites: a final metabolite of somatostatin analogues, (177)Lu-DOTA-DPhe, and a tripeptide metabolite of (177)Lu-DOTA-minigastrin 11, (177)Lu-DOTA-DGlu-Ala-Tyr. Their pharmacokinetics was compared with that of respective parent (177)Lu-radiopeptide. Both radiometabolites exhibited relative rapid clearing from most body tissues in rats in vivo along with predominant renal excretion. The long-term renal retention of the smaller radiometabolite (177)Lu-DOTA-DPhe was lower than that of (177)Lu-DOTA-DGlu-Ala-Tyr. An uptake of (177)Lu-DOTA-DPhe by human renal influx transporter organic cation transporter 2 was found in vitro in a cellular model. The study brings the first experimental data on the in vivo pharmacokinetics of radiometabolites of receptor-specific somatostatin and gastrin analogues. The found results may indicate a negative correlation between the degree of decomposition of the parent peptide chain and the renal retention of the metabolite. Copyright © 2015 John Wiley & Sons, Ltd.

Morphology evolution and pure red upconversion mechanism of β-NaLuF4 crystals.

PubMed

Lin, Hao; Xu, Dekang; Li, Anming; Teng, Dongdong; Yang, Shenghong; Zhang, Yueli

2016-06-16

A series of β-NaLuF4 crystals were synthesized via a hydrothermal method. Hexagonal phase microdisks, microprisms, and microtubes were achieved by simply changing the amount of citric acid in the initial reaction solution. Pure red upconversion (UC) luminescence can be observed in β-NaLuF4:Yb(3+), Tm(3+), Er(3+) and Li(+) doped β-NaLuF4:20% Yb(3+), 1% Tm(3+), 20% Er(3+). Based on the rate equations, we report the theoretical model about the pure red UC mechanism in Yb(3+)/Tm(3+)/Er(3+) doped system. It is proposed that the pure red UC luminescence is mainly ascribed to the energy transfer UC from Tm(3+):(3)F4 → (3)H6 to Er(3+):(4)I11/2 → (4)F9/2 and the cross-relaxation (CR) effect [Er(3+):(4)S3/2 + (4)I15/2 → (4)I9/2 + (4)I13/2] rather than the long-accepted mechanism [CR process among Er(3+):(4)F7/2 + (4)I11/2 → (4)F9/2 + (4)F9/2]. In addition, compared to the Li(+)-free counterpart, the pure red UC luminescence in β-NaLuF4:20% Yb(3+), 1% Tm(3+), 20% Er(3+) with 15 mol% Li(+) doping is enhanced by 13.7 times. This study provides a general and effective approach to obtain intense pure red UC luminescence, which can be applied to other synthetic strategies.

Morphology evolution and pure red upconversion mechanism of β-NaLuF4 crystals

PubMed Central

Lin, Hao; Xu, Dekang; Li, Anming; Teng, Dongdong; Yang, Shenghong; Zhang, Yueli

2016-01-01

A series of β-NaLuF4 crystals were synthesized via a hydrothermal method. Hexagonal phase microdisks, microprisms, and microtubes were achieved by simply changing the amount of citric acid in the initial reaction solution. Pure red upconversion (UC) luminescence can be observed in β-NaLuF4:Yb3+, Tm3+, Er3+ and Li+ doped β-NaLuF4:20% Yb3+, 1% Tm3+, 20% Er3+. Based on the rate equations, we report the theoretical model about the pure red UC mechanism in Yb3+/Tm3+/Er3+ doped system. It is proposed that the pure red UC luminescence is mainly ascribed to the energy transfer UC from Tm3+:3F4 → 3H6 to Er3+:4I11/2 → 4F9/2 and the cross-relaxation (CR) effect [Er3+:4S3/2 + 4I15/2 → 4I9/2 + 4I13/2] rather than the long-accepted mechanism [CR process among Er3+:4F7/2 + 4I11/2 → 4F9/2 + 4F9/2]. In addition, compared to the Li+-free counterpart, the pure red UC luminescence in β-NaLuF4:20% Yb3+, 1% Tm3+, 20% Er3+ with 15 mol% Li+ doping is enhanced by 13.7 times. This study provides a general and effective approach to obtain intense pure red UC luminescence, which can be applied to other synthetic strategies. PMID:27306720

Scintillation properties of Nd 3+, Tm 3+, and Er 3+ doped LuF 3 scintillators in the vacuum ultra violet region

NASA Astrophysics Data System (ADS)

Yanagida, Takayuki; Kawaguchi, Noriaki; Fukuda, Kentaro; Kurosawa, Shunsuke; Fujimoto, Yutaka; Futami, Yoshisuke; Yokota, Yuui; Taniue, Kojiro; Sekiya, Hiroyuki; Kubo, Hidetoshi; Yoshikawa, Akira; Tanimori, Toru

2011-12-01

In order to develop novel vacuum ultra violet (VUV) emitting scintillators, we grew Nd 0.5%, Tm 0.5%, and Er 0.5% doped LuF3 scintillators by the μ-pulling down method, because LuF3 has a very wide band gap and Nd3+, Tm3+, and Er3+ luminescence centers show fast and intense 5d-4f emission in VUV region. Transmittance and X-ray induced radioluminescence were studied in these three samples using our original spectrometer made by Bunkou-Keiki company. In the VUV region, transmittance of 20-60% was achieved for all the samples. The emission peaks appeared at approximately 180, 165, and 164 nm for Nd3+, Tm3+, and Er3+ doped LuF3, respectively. Using PMT R8778 (Hamamatsu), we measured their light yields under 241Am α-ray excitation. Compared with Nd:LaF3 scintillator, which has 33 photoelectrons/5.5 MeV α, Nd:LuF3 and Tm:LuF3 showed 900±90 and 170±20 ph/5.5 MeV-α, respectively. Only for the Nd doped one, we can detect 137Cs 662 keV γ-ray photoabsorption peak and the light yield of 1200±120 ph/MeV was measured. We also investigated their decay time profiles by picosecond pulse X-ray equipped streak camera, and the main decay component of Nd:LuF3 turned out to be 7.63 ns.

Low carrier semiconductor like behavior in Lu3Ir4Ge13 single crystal

NASA Astrophysics Data System (ADS)

Kumar, Anil; Matteppanavar, Shidaling; Thamizhavel, A.; Ramakrishnan, S.

2018-04-01

Single crystal of Lu3Ir4Ge13 crystallizing in the Yb3Rh4Sn13-type cubic crystal structure has been grown by Czochralski method in a tetra-arc furnace. In this paper we report on the crystal structure, magnetic and transport properties of Lu3Ir4Ge13. The analysis of the powder x-ray diffraction (XRD) studies revealed that Lu3Ir4Ge13 crystallizes in a cubic structure with the space group Pm-3n, no. 223. The lattice parameter was obtained from the Rietveld refinement of the room temperature XRD data which amounts to 8.904 (3) Å with low R factors. The temperature dependence of the resistivity exhibited semiconductor like behavior till 1.8 K, with a broad hump around 15 - 62 K. This hump was observed in both warming and cooling cycle with a very small hysteresis, it may be due to the existence of structural transition from high - low symmetry. The temperature dependent magnetization data shows the diamagnetic behavior with an anomaly around 70 K, which is well supported by the derivative of resistivity data.

Features of the band structure and conduction mechanisms of n-HfNiSn semiconductor heavily Lu-doped

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

Romaka, V. A., E-mail: vromaka@polynet.lviv.ua; Rogl, P.; Romaka, V. V.

2015-03-15

The crystal and electronic structures, energy, kinetic, and magnetic characteristics of n-HfNiSn semiconductor heavily doped with a Lu acceptor impurity in the ranges T = 80–400 K and N{sub A}{sup Lu} ≈ 1.9 × 10{sup 20}−1.9 × 10{sup 21} cm{sup −3} (x = 0.01–0.10) at H ≤ 10 kG is studied. The nature of the structural-defect generation mechanism leading to changes in the band gap and the degree of semiconductor compensation is determined. Its essence is the simultaneous reduction and elimination of donor-type structural defects due to the displacement of ∼1% of Ni atoms from the Hf (4a) site, themore » generation of acceptor-type structural defects by substituting Ni atoms with Lu atoms at the 4c site, and the generation of donor-type defects such as vacancies at the Sn (4b) site. The results of calculations of the electronic structure of Hf{sub 1−x}Lu{sub x}NiSn are in agreement with experimental data. The results are discussed within the model of a heavily doped and compensated Shklovskii-Efros semiconductor.« less

Characterization of 176Lu background in LSO-based PET scanners

NASA Astrophysics Data System (ADS)

Conti, Maurizio; Eriksson, Lars; Rothfuss, Harold; Sjoeholm, Therese; Townsend, David; Rosenqvist, Göran; Carlier, Thomas

2017-05-01

LSO and LYSO are today the most common scintillators used in positron emission tomography. Lutetium contains traces of 176Lu, a radioactive isotope that decays β - with a cascade of γ photons in coincidence. Therefore, Lutetium-based scintillators are characterized by a small natural radiation background. In this paper, we investigate and characterize the 176Lu radiation background via experiments performed on LSO-based PET scanners. LSO background was measured at different energy windows and different time coincidence windows, and by using shields to alter the original spectrum. The effect of radiation background in particularly count-starved applications, such as 90Y imaging, is analysed and discussed. Depending on the size of the PET scanner, between 500 and 1000 total random counts per second and between 3 and 5 total true coincidences per second were measured in standard coincidence mode. The LSO background counts in a Siemens mCT in the standard PET energy and time windows are in general negligible in terms of trues, and are comparable to that measured in a BGO scanner of similar size.

Treatment with tandem [90Y]DOTA-TATE and [177Lu]DOTA-TATE of neuroendocrine tumours refractory to conventional therapy.

PubMed

Seregni, E; Maccauro, M; Chiesa, C; Mariani, L; Pascali, C; Mazzaferro, V; De Braud, F; Buzzoni, R; Milione, M; Lorenzoni, A; Bogni, A; Coliva, A; Lo Vullo, S; Bombardieri, E

2014-02-01

Peptide receptor radionuclide therapy (PRRT) with radiolabelled somatostatin analogues has been demonstrated to be an effective therapeutic option in patients with disseminated neuroendocrine tumours (NET). Treatment with tandem [(90)Y]DOTA-TATE and [(177)Lu]DOTA-TATE may improve the efficacy of PRRT without increasing the toxicity. In a phase II study we evaluated the feasibility of combined PPRT with a high-energy beta emitter ((90)Y) and a medium-energy beta/gamma emitter ([(177)Lu) in patients with metastatic NET refractory to conventional therapy. A group of 26 patients with metastatic NET were treated with four therapeutic cycles of alternating [[(177)Lu]DOTA-TATE (5.55 GBq) and [(90)Y]DOTA-TATE (2.6 GBq). A dosimetric evaluation was carried out after administration of [[(177)Lu]DOTA-TATE to calculate the absorbed doses in healthy organs. The acute and long-term toxicities of repeated treatment were analysed. PRRT efficacy was evaluated according to RECIST. Administration of tandem [(90)Y]DOTA-TATE and [[(177)Lu]DOTA-TATE induced objective responses in 42.3 % of patients with metastatic NET with a median progression-free survival longer than 24 months. Of patients with pretreatment carcinoid syndrome, 90 % showed a symptomatic response or a reduction in tumour-associated pain. The cumulative biologically effective doses (BED) were below the toxicity limit in the majority of patients, in the absence of renal function impairment. The results of our study indicates that combined [(90)Y]DOTA-TATE and [(177)Lu]DOTA-TATE therapy is a feasible and effective therapeutic option in NET refractory to conventional therapy. Furthermore, the absence of kidney damage and the evaluated cumulative BEDs suggest that increasing the number of tandem administrations is an interesting approach.

The Spatial-Temporal Analysis of Ecological Environment of Red Bed Hills in East Sichuan - Taking LU County as a Case

NASA Astrophysics Data System (ADS)

Liu, H.; Liu, Y.; Wang, X.; Liu, J.

2018-04-01

Good ecological environment is the foundation of human existence and development, the development of society and economy must be based on the premise of maintaining the stability and balance of the ecological environment. RS and GIS technology are used in this paper while the red-bed hills of Sichuan Province-Lu County have been taken as an example. According to the ecological environment characteristics of the study areas and the principle of choosing evaluation index, this paper selected six evaluation indicators (elevation, slope, aspect, vegetation cover, land use, gully density) to establish evaluation index system of ecological environment of Lu County. This paper determine the weight of each evaluation index by AHP (Analytic Hierarchy Process) and establishes a comprehensive evaluation model by the weighted comprehensive evaluation method. This model is used to divide the ecological environment quality of Lu County into excellent, good, middle, poor and worse, and to analyze the ecological environment change in Lu County in recent ten years.

Spatial and temporal distribution of Mesozoic adakitic rocks along the Tan-Lu fault, Eastern China: Constraints on the initiation of lithospheric thinning

NASA Astrophysics Data System (ADS)

Gu, Hai-Ou; Xiao, Yilin; Santosh, M.; Li, Wang-Ye; Yang, Xiaoyong; Pack, Andreas; Hou, Zhenhui

2013-09-01

The Mesozoic tectonics in East China is characterized by significant lithospheric thinning of the North China Craton, large-scale strike-slip movement along the Tan-Lu fault, and regional magmatism with associated metallogeny. Here we address the possible connections between these three events through a systematic investigation of the geochemistry, zircon geochronology and whole rock oxygen isotopes of the Mesozoic magmatic rocks distributed along the Tan-Lu fault in the Shandong province. The characteristic spatial and temporal distributions of high-Mg adakitic rocks along the Tan-Lu fault with emplacement ages of 134-128 Ma suggest a strong structural control for the emplacement of these intrusions, with magma generation possibly associated with the subduction of the Pacific plate in the early Cretaceous. The low-Mg adakitic rocks (127-120 Ma) in the Su-Lu orogenic belt were formed later than the high-Mg adakitic rocks, whereas in the Dabie orogenic belt, most of the low-Mg adakitic rocks (143-129 Ma) were generated earlier than the high-Mg adakitic rocks. Based on available data, we suggest that the large scale strike-slip tectonics of the Tan-Lu fault in the Mesozoic initiated cratonic destruction at the south-eastern margin of the North China Craton, significantly affecting the lower continental crust within areas near the fault. This process resulted in crustal fragments sinking into the asthenosphere and reacting with peridotites, which increased the Mg# of the adakitic melts, generating the high-Mg adakitic rocks. The gravitationally unstable lower continental crust below the Tan-Lu fault in the Su-Lu orogenic belt triggered larger volume delamination of the lower continental crust or foundering of the root.

Block recursive LU preconditioners for the thermally coupled incompressible inductionless MHD problem

NASA Astrophysics Data System (ADS)

Badia, Santiago; Martín, Alberto F.; Planas, Ramon

2014-10-01

The thermally coupled incompressible inductionless magnetohydrodynamics (MHD) problem models the flow of an electrically charged fluid under the influence of an external electromagnetic field with thermal coupling. This system of partial differential equations is strongly coupled and highly nonlinear for real cases of interest. Therefore, fully implicit time integration schemes are very desirable in order to capture the different physical scales of the problem at hand. However, solving the multiphysics linear systems of equations resulting from such algorithms is a very challenging task which requires efficient and scalable preconditioners. In this work, a new family of recursive block LU preconditioners is designed and tested for solving the thermally coupled inductionless MHD equations. These preconditioners are obtained after splitting the fully coupled matrix into one-physics problems for every variable (velocity, pressure, current density, electric potential and temperature) that can be optimally solved, e.g., using preconditioned domain decomposition algorithms. The main idea is to arrange the original matrix into an (arbitrary) 2 × 2 block matrix, and consider an LU preconditioner obtained by approximating the corresponding Schur complement. For every one of the diagonal blocks in the LU preconditioner, if it involves more than one type of unknowns, we proceed the same way in a recursive fashion. This approach is stated in an abstract way, and can be straightforwardly applied to other multiphysics problems. Further, we precisely explain a flexible and general software design for the code implementation of this type of preconditioners.

Lu & Malenchenko work on storage batteries in Zvezda taken during STS-106

NASA Image and Video Library

2000-09-13

STS106-388-011 (8-20 September 2000) --- Cosmonaut Yuri I. Malenchenko (top), and astronaut Edward T. Lu, both mission specialists, work inside panels in the Zvezda Service Module on the International Space Station (ISS). Malenchenko represents Rosaviakosmos.

A New World: Redefining the Legacy of Min-Zhan Lu

ERIC Educational Resources Information Center

Ray, Brian

2008-01-01

This article discusses exchanges between a number of scholars during the 1990s centering on Min-Zhan Lu's controversial essay "Conflict and Struggle: The Enemies or Preconditions of Basic Writing?" In some ways, "Conflict and Struggle" blazed a trail for later work in "hybrid" or "mixed" forms of academic writing while at the same time igniting…

Development and biological studies of ¹⁷⁷Lu-DOTA-rituximab for the treatment of Non-Hodgkin's lymphoma.

PubMed

Massicano, Adriana V F; Pujatti, Priscilla B; Alcarde, Lais F; Suzuki, Miriam F; Spencer, Patrick J; Araújo, Elaine B

2016-01-01

The optimization of DOTA-NHS-ester conjugation to Rituximab using different Ab:DOTA molar ratios (1:10, 1:20, 1:50 and 1:100) was studied. High radiochemical yield, in vitro stability and immunoreactive fraction were obtained for the Rituximab conjugated at 1:50 molar ratio, resulting in the incorporation of an average number of 4.9 ± 1.1 DOTA per Rituximab molecule. Labeling with 177Lu was performed in high specific activity with great in vitro stability. Biodistribution in healthy and xenographed mice showed tumor uptake and high in vivo stability as evidenced by low uptake in bone. The properties of 177Lu-DOTA-Rituximab prepared from DOTA-NHS-ester suggest the potential for the application of the 177Lu-labeled antibody in preliminary clinical studies.

Pre-Clinical Assessment of Lu-Labeled Trastuzumab Targeting HER2 for Treatment and Management of Cancer Patients with Disseminated Intraperitoneal Disease.

PubMed

Ray, Geoffrey L; Baidoo, Kwamena E; Keller, Lanea M M; Albert, Paul S; Brechbiel, Martin W; Milenic, Diane E

2011-12-22

Studies from this laboratory have demonstrated the potential of targeting HER2 for therapeutic and imaging applications with medically relevant radionuclides. To expand the repertoire of trastuzumab as a radioimmunoconjugate (RIC) vector, use of (177)Lu was investigated. The combination of a 6.7 d half-life, lower energy β(-)-emissions (500 keV max; 130 keV ave), and an imagable γ-emission make (177)Lu an attractive candidate for radioimmunotherapy (RIT) regimens for treatment of larger tumor burdens not possible with α-zparticle radiation. Radiolabeling trastuzumab-CHX-A"-DTPA with (177)Lu was efficient with a specific binding of 60.8 ± 6.8% with HER2 positive SKOV-3 cells. Direct quantitation of tumor targeting and normal tissue uptake was performed with athymic mice bearing subcutaneous and intraperitoneal LS-174T xenografts; a peak tumor %ID/g of 24.70 ± 10.29 (96 h) and 31.70 ± 16.20 (72 h), respectively, was obtained. Normal tissue uptake of the RIC was minimal. Tumor targeting was also demonstrated by γ-scintigraphy. A therapy study administering escalating doses of (177)Lu-trastuzumab to mice bearing three day LS-174T i.p. xenografts established the effective therapeutic dose of i.p. administered (177)Lu-trastuzumab at 375 μCi with a median survival of 124.5 d while a median survival of 10 d was noted for the control (untreated) group. In conclusion, trastuzumab radiolabeled with (177)Lu has potential for treatment of disseminated, HER2 positive, peritoneal disease.

High efficiency microcolumnar Lu2O3:Eu scintillator thin film for hard X-ray microtomography

NASA Astrophysics Data System (ADS)

Marton, Z.; Bhandari, H. B.; Brecher, C.; Miller, S. R.; Singh, B.; Nagarkar, V. V.

2013-03-01

We have developed microstructured Lu2O3:Eu scintillator films capable of providing spatial resolution on the order of micrometers for hard X-ray imaging. In addition to their extraordinary resolution, Lu2O3:Eu films simultaneously provide high absorption efficiency for 20 to 100 keV X-rays, and bright 610 nm emission, with intensity rivalling that of the brightest known scintillators. At present, high spatial resolution of such a magnitude is achieved using ultra-thin scintillators measuring only about 1 to 5 μm in thickness, which limits absorption efficiency to ~3% for 12 keV X-rays and less than 0.1% for 20 to 100 keV X-rays, resulting in excessive measurement time and exposure to the specimen. Lu2O3:Eu would significantly improve that (99.9% @12 keV and 30% @ 70 keV). Important properties and features of our Lu2O3:Eu scintillator material, fabricated by our electron-beam physical vapour deposition (EB-PVD) process, combines superior density of 9.5 g/cm3, microcolumnar structure emitting 48000 photons/MeV whose wavelength is an ideal match for the underlying CCD detector array. We grew thin films measuring 5-50μm in thickness as well as covering areas up to 5 × 5 cm2 which can be a suitable basis for microtomography, digital radiography as well as CT and hard X-ray Micro-Tomography (XMT).

Cumulated Activity Comparison of 64Cu-/177Lu-Labeled Anti-Epidermal Growth Factor Receptor Antibody in Esophageal Squamous Cell Carcinoma Model.

PubMed

Laffon, Eric; Thumerel, Matthieu; Jougon, Jacques; Marthan, Roger

2017-06-01

This work aimed at estimating the kinetic parameters, and hence cumulated activity (A C ), of a diagnostic/therapeutic convergence radiopharmaceutical, namely 64 Cu-/ 177 Lu-labeled antibody ( 64 Cu-/ 177 Lu-cetuximab), that acts as anti-epidermal growth factor receptor. Methods: In mice bearing esophageal squamous cell carcinoma tumors, to estimate uptake (K), release rate constant (k R ), and hence A C , a kinetic model analysis was applied to recently published biodistribution data of immuno-PET imaging with 64 Cu-cetuximab and of small-animal SPECT/CT imaging with 177 Lu-cetuximab, including blood and TE-8 tumor. Results: K, k R , and A C were estimated to be 0.0566/0.0593 g⋅h -1 ⋅g -1 , 0.0150/0.0030 h -1 , and 2.3 × 10 10 /4.1 × 10 12 disintegrations (per gram of TE-8 tumor), with an injected activity of 3.70/12.95 MBq, for 64 Cu-/ 177 Lu-cetuximab, respectively. Conclusion: A model is available for comparing kinetic parameters and A C of the companion diagnostic/therapeutic 64 Cu-/ 177 Lu-cetuximab that may be considered as a step for determining whether one can really use the former to predict dosimetry of the latter. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Expedition Seven Lu with EMU in Quest airlock

NASA Image and Video Library

2003-09-05

ISS007-E-14470 (5 September 2003) --- Astronaut Edward T. Lu, Expedition 7 NASA ISS science officer and flight engineer, performs routine maintenance on an Extravehicular Mobility Unit (EMU) space suit in the Quest airlock on the International Space Station (ISS). The work represents a mid-term checkout and included emptying and refilling the suit’s water tank and loops, cycling relief valves, checking sensors and collecting data, a leak check and running the suit’s fan for two hours to lubricate it.

Expedition Seven Lu with EMU in Quest airlock

NASA Image and Video Library

2003-09-05

ISS007-E-14473 (5 September 2003) --- Astronaut Edward T. Lu, Expedition 7 NASA ISS science officer and flight engineer, performs routine maintenance on an Extravehicular Mobility Unit (EMU) space suit in the Quest airlock on the International Space Station (ISS). The work represents a mid-term checkout and included emptying and refilling the suit’s water tank and loops, cycling relief valves, checking sensors and collecting data, a leak check and running the suit’s fan for two hours to lubricate it.

Expedition Seven Lu with EMU in Quest airlock

NASA Image and Video Library

2003-09-05

ISS007-E-14469 (5 September 2003) --- Astronaut Edward T. Lu, Expedition 7 NASA ISS science officer and flight engineer, performs routine maintenance on an Extravehicular Mobility Unit (EMU) space suit in the Quest airlock on the International Space Station (ISS). The work represents a mid-term checkout and included emptying and refilling the suit’s water tank and loops, cycling relief valves, checking sensors and collecting data, a leak check and running the suit’s fan for two hours to lubricate it.

Expedition Seven Lu with EMU in Quest airlock

NASA Image and Video Library

2003-09-05

ISS007-E-14472 (5 September 2003) --- Astronaut Edward T. Lu, Expedition 7 NASA ISS science officer and flight engineer, performs routine maintenance on an Extravehicular Mobility Unit (EMU) space suit in the Quest airlock on the International Space Station (ISS). The work represents a mid-term checkout and included emptying and refilling the suit’s water tank and loops, cycling relief valves, checking sensors and collecting data, a leak check and running the suit’s fan for two hours to lubricate it.

Crystal growth and scintillation properties of Nd-doped Lu 3Al 5O 12 single crystals with different Nd concentrations

NASA Astrophysics Data System (ADS)

Sugiyama, Makoto; Fujimoto, Yutaka; Yanagida, Takayuki; Yokota, Yuui; Pejchal, Jan; Furuya, Yuki; Tanaka, Hidehiko; Yoshikawa, Akira

2011-04-01

Nd 0.1%, 0.5%, 1% and 3% doped Lu 3Al 5O 12 (Nd:LuAG) single crystals were grown in the nitrogen atmosphere by the micro-pulling down (μ-PD) method. The grown crystals had a single-phase confirmed by powder XRD analysis. In absorption spectra, some weak absorption lines due to Nd 3+ 4f-4f transitions were observed and their intensity increased with the increase of Nd concentration. When excited by 241Am α-ray, a broad emission peak due to defects in the host lattice at 320 nm and some sharp lines due to Nd 3+ 4f-4f transitions at wavelength longer than 400 nm were observed. The decay time profiles of Nd:LuAG under γ-ray excitation were well approximated by two exponential function of 340-760 ns and 3-5 μs for each sample. By pulse height measurement using 137Cs, Nd 0.5%:LuAG showed the highest light yield of 7600 ± 760 photons/MeV.

Enhanced room temperature multiferroic characteristics in hexagonal LuFe1-xNixO3 (x = 0 - 0.3) nanoparticles

NASA Astrophysics Data System (ADS)

Suresh, Pittala; Vijaya Laxmi, K.; Anil Kumar, P. S.

2018-02-01

Single phase polycrystalline LuFe1-xNixO3 (x = 0 - 0.3) (LFNO) nanoparticles are synthesized using the sol-gel method. X-ray diffraction measurements revealed that the crystal structure of Ni-doped samples is isomorphic to hexagonal LuFeO3 (LFO). The phase pure hexagonal P63cm symmetry exists for 0 ≤ x ≤ 0.3, and the secondary phases appear for x ≥ 0.4. Raman spectra show a shift in the mode frequency corresponding to the changes in Lu-O and Fe-O bond lengths with Ni doping. An enhancement in the magnetization is observed for LFNO throughout the temperature range (400-5 K) compared to LFO. The antiferromagnetic state of LFO becomes ferrimagnetic at low temperatures, and a net magnetization is observed at room temperature with Ni doping. As Ni concentration increases, a systematic increment in the ferroelectric polarization is observed. This enhancement in polarization is believed to be due to the distortion in FeO5 cage, while the improvement in magnetic properties is due to the induced magnetic interactions, caused by the Fe-Ni interactions on the triangular lattice with Ni doping in LuFeO3.

Importance of the Lu-Hf isotopic system in studies of planetary chronology and chemical evolution

USGS Publications Warehouse

Patchett, P.J.

1983-01-01

The 176Lu-176Hf isotope method and its applications in earth sciences are discussed. Greater fractionation of Lu/Hf than Sm/Nd in planetary magmatic processes makes 176Hf 177Hf a powerful geochemical tracer. In general, proportional variations of 176Hf 177Hf exceed those of 143Nd l44Nd by factors of 1.5-3 in terrestrial and lunar materials. Lu-Hf studies therefore have a major contribution to make in understanding of terrestrial and other planetary evolution through time, and this is the principal importance of Lu-Hf. New data on basalts from oceanic islands show unequivocally that whereas considerable divergences occur in 176Hf 177Hf- 87Sr 86Sr and 143Nd l44Nd- 87Sr 86Sr diagrams, 176Hf 177Hf and 143Nd 144Nd display a single, linear isotopic variation in the suboceanic mantle. These discordant 87Sr 86Sr relationships may allow, with the acquisition of further Hf-Nd-Sr isotopic data, a distinction between processes such as mantle metasomatism, influence of seawater-altered material in the magma source, or recycling of sediments into the mantle. In order to evaluate the Hf-Nd isotopic correlation in terms of mantle fractionation history, there is a need for measurements of Hf distribution coefficients between silicate minerals and liquids, and specifically for a knowledge of Hf behavior in relation to rareearth elements. For studying ancient terrestrial Hf isotopic variations, the best quality Hf isotope data are obtained from granitoid rocks or zircons. New data show that very U-Pb discordant zircons may have upwardly-biased 176Hf 177Hf, but that at least concordant to slightly discordant zircons appear to be reliable carriers of initial 176Hf 177Hf. Until the controls on addition of radiogenic Hf to zircon are understood, combined zircon-whole rock studies are recommended. Lu-Hf has been demonstrated as a viable tool for dating of ancient terrestrial and extraterrestrial samples, but because it offers little advantage over existing methods, is unlikely to find

Relevant tumor sink effect in prostate cancer patients receiving 177Lu-PSMA-617 radioligand therapy.

PubMed

Filss, Christian; Heinzel, Alexander; Miiller, Berthold; Vogg, Andreas T J; Langen, Karl-Josef; Mottaghy, Felix M

2018-02-01

In metastatic prostate cancer patients PSMA targeting radioligands have gained significant impact as theranostic probes. In this study a correlation between total tumor volume (TTV) and measured kidney dose as well as salivary glands (SG) uptake in 177 Lu-PSMA-617 therapy was evaluated. Eleven consecutive prostate cancer patients receiving a first cylcle of 177 Lu-PSMA-617 (administered activity of approximately 6GBq) were included. The 68 Ga-PSMA-11 PET/CT scan previous to therapy was used to determine TTV and SG uptake (glandulae submandibularis) employing PMOD version 3.403 with different 68 Ga-PSMA-11 thresholds based on the standardized uptake value (SUV).The kidney dose was estimated with the software ULMDOS using planar whole-body scintigrams. Kidney dose and SG uptake was inversely correlated to TTV, indicating high kidney dose and high SG uptake in case of low tumor load and low kidney dose and low SG uptake in case of high tumor load. Our data support the hypothesis that in 177 Lu-PSMA-617 therapy an individualized treatment activity based on total tumor volume could be beneficiary. Schattauer GmbH.

Illustrations of neurosurgical techniques in early period of Ottoman Empire by Serefeddin Sabuncuoğlu.

PubMed

Turgut, M

2007-10-01

Serefeddin Sabuncuoğlu (A.D. 1385-1468) was the author of the first illustrated surgery atlas Cerrahiyyetü'l Haniyye (Imperial Surgery), which was written in Turkish in 1465. The purpose of this report is to present his unique contribution to modern neurological surgery. Cerrahiyyetü'l Haniyye consists of 412 pages in three chapters, in which there are a total of 191 sections dealing with a variety of surgical specialties, including neurosurgery. In each section of the book, a sentence written in rhyme and meter gives the diagnosis, classification and surgical technique in detail. Serefeddin Sabuncuoğlu describes medical and surgical management of neurological diseases such as spinal trauma, epilepsy, migraine, facial palsy, hemiplegia, low back pain, cranial fracture, hydrocephalus and abscesses of the head in his textbook. Serefeddin Sabuncuoğlu was a great surgeon in Turkish medical history and the sections on neurological diseases in Cerrahiyyetü'l Haniyye are of great importance in neurosurgery. Today, he is justified as a pioneer of surgery, an investigator and a medical illustrator in the early period of Ottoman Empire. His atlas is a modification of original contributions from earlier treatises.

[Treatment of Gastroenteropancreatic Neuroendocrine Tumors with 177Lu-DOTA-TATE: Experience of the Portuguese Institute of Oncology in Porto].

PubMed

Sampaio, Inês Lucena; Luiz, Henrique Vara; Violante, Liliana Sobral; Santos, Ana Paula; Antunes, Luís; Torres, Isabel; Sanches, Cristina; Azevedo, Isabel; Duarte, Hugo

2016-11-01

The purpose of this article is to report the experience of the Portuguese Institute of Oncology - Porto in the treatment of gastroenteropancreatic neuroendocrine tumors with 177Lu-DOTA-TATE, regarding the safety and efficacy of this treatment modality. A retrospective analysis of clinical reports of patients with gastroenteropancreatic neuroendocrine tumors undergoing treatment with 177Lu-DOTA-TATE between April 2011 and November 2013 was performed. Thirty six cases were reviewed and 30 completed all 3 cycles of 177Lu-DOTA-TATE (83.3%). In these patients it was registered: acute side effects in 8.9% of cycles; grade 3 CTCAE liver toxicity in 13.3% of patients (all with previous abnormal liver function); absence of significant renal or hematologic toxicity; symptomatic improvement in 71.4% of patients; median overall time to progression of 25.6 months; median overall survival from diagnosis of 121.7 months. Patients with higher expression of somatostatin receptors had longer progression-free survival and overall survival times (p < 0.05). Peptide receptor radionuclide therapy with 177Lu-DOTA-TATE is an effective, safe and well-tolerated treatment, as evidenced in our study by the following findings: symptomatic improvement in most patients and increased time to disease progression and survival (especially in those with higher sstr expression), with acute and significant subacute/chronic side effects reported only in a minority of cases. Peptide receptor radionuclide therapy with 177Lu-DOTA-TATE is a promising treatment for patients with gastroenteropancreatic neuroendocrine tumors, with demonstrated benefits in terms of safety and efficacy.

Resolution, the key to unlocking granite petrogenesis using zircon U-Pb - Lu-Hf studies

NASA Astrophysics Data System (ADS)

Tapster, Simon; Horstwood, Matthew; Roberts, Nick M. W.; Deady, Eimear; Shail, Robin

2017-04-01

Coarse-scale understanding of crustal evolution and source contributions to igneous systems has been drastically enhanced by coupled zircon U-Pb and Lu-Hf data sets. These are now common place and potentially offer advantages over whole-rock analyses by resolving heterogeneous source components in the complex crystal cargos of single hand-samples. However, the application of coupled zircon U-Pb and Lu-Hf studies to address detailed petrogenetic questions faces a crisis of resolution - On the one hand, micro-beam analytical techniques have high spatial resolution, capable of interrogating crystals with complex growth histories. Yet, the >1-2% temporal resolution of these techniques places a fundamental limitation on their utility for developing petrogenetic models. This limitation in data interpretation arises from timescales of crystal recycling or changes in source evolution that are often shorter than the U-Pb analytical precision. Conversely, high-precision CA-ID-TIMS U-Pb analysis of single whole zircons and solution MC-ICP-MS Lu-Hf isotopes of column washes (Hf masses equating to ca. 10-50 ng) have much greater temporal resolution (<0.1%), yet lack the spatial resolution to deal with complex crystal growth. Analyses homogenize any heterogeneity within the zircon and convolute the petrogenetic model. A balance must be struck between spatial and temporal resolution to address petrogenetic issues. Here, we demonstrate that micro-sampling of complex xenocryst-rich zircon crystals (e.g. <40 µm zircon tips) from the granitic post-Variscan Cornubian Batholith (SW England), in tandem with low-common Pb blank CA-ID-TIMS U-Pb chemistry, permits the analysis of zircon volumes that approach those of LA-ICPMS analyses, whilst simultaneously retaining the majority of the temporal resolution associated with the CA-ID-TIMS U-Pb technique. The low volume of zircon within these analyses may only provide <5 ng Hf, and therefore gaining useful precision from Lu-Hf isotopes is

Evaluation of cytotoxic and tumor targeting capability of (177)Lu-DOTATATE-nanoparticles: a trailblazing strategy in peptide receptor radionuclide therapy.

PubMed

Arora, Geetanjali; Dubey, Priyanka; Shukla, Jaya; Ghosh, Sourabh; Bandopadhyaya, Gurupad

2016-06-01

We propose an innovative strategy of nanoparticle-mediated-peptide receptor radionuclide therapy (PRRT) employing PLGA-nanoparticles together with anti-β-hCG antibodies that can protect kidneys from radiation damage while simultaneously enhancing its tumor targeting and cytotoxic ability for somatostatin receptor (SSR) positive tumors. PEG-coated-(177)Lu-DOTATATE-PLGA-nanoparticles (PEG-LuD-NP) were formulated and characterized. In vitro toxicity of these particles was tested on human glioblastoma cell line U87MG over a radiation dose range of 19-78 Gy, using MTT assay and flow cytometry. To further enhance cytotoxicity and test the feasibility of active tumor targeting, apoptosis-inducing anti-β-hCG monoclonal antibodies were employed in vitro, after confirming expression of β-hCG on U87MG. In vivo tumor targeting ability of these particles, in comparison to uncoated particles and un-encapsulated (177)Lu-DOTATATE, was assessed by intravenous administration in tumor-induced wistar rats. Rats were first imaged in a gamma camera followed by euthanasia for organ extraction and counting in gamma counter. The particles were spherical in shape with mean diameter of 300 nm. Highest cytotoxicity that could be achieved with PEG-LuD-NP, on radio-resistant U87MG cells, was 35.8 % due to complex cellular response triggered by ionizing radiation. Interestingly, synergistic action of antibodies and PEG-LuD-NP doubled the cytotoxicity (80 %). PEG-LuD-NP showed the highest tumor uptake (4.3 ± 0.46 % ID/g) as compared to (177)Lu-DOTATATE (3.5 ± 0.31 %) and uncoated-(177)Lu-DOTATATE-nanoparticles (3.4 ± 0.35 %) in tumor-inoculated wistar rats (p < 0.001). Renal uptake/retention was decreased 3-4 folds with these particles, resulting in the highest tumor-to-kidney ratio (8.58; p < 0.01) while tumor-to-liver and tumor-to-bone ratios were comparable to un-encapsulated-drug. Nanocarrier-mediated-PRRT is an effective way of targeting SSR positive tumors for

177Lu-Labeled Prostate-Specific Membrane Antigen Radioligand Therapy of Metastatic Castration-Resistant Prostate Cancer: Safety and Efficacy.

PubMed

Baum, Richard P; Kulkarni, Harshad R; Schuchardt, Christiane; Singh, Aviral; Wirtz, Martina; Wiessalla, Stefan; Schottelius, Margret; Mueller, Dirk; Klette, Ingo; Wester, Hans-Jürgen

2016-07-01

The objective of this study was to analyze the safety and efficacy of the (177)Lu-labeled DOTAGA-based prostate-specific membrane antigen (PSMA) ligand (177)Lu-DOTAGA-(I-y)fk(Sub-KuE) ((177)Lu-PSMA) in patients with metastatic castration-resistant prostate cancer (mCRPC). Fifty-six mCRPC patients underwent PSMA radioligand therapy (RLT) with (177)Lu-PSMA. (68)Ga-PSMA-(N,N'-bis-[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N'-diacetic acid) ((68)Ga-PSMA) PET/CT was used for patient selection and follow-up after PSMA RLT. Hematologic status, renal function, and serum prostate-specific antigen levels were documented before and after therapy. Dosimetry was performed in 30 patients. (177)Lu-PSMA demonstrated high absorbed tumor doses (median, 3.3 mGy/MBq) compared with the levels in normal organs. Parotid glands received higher doses (1.3 mGy/MBq) than kidneys (0.8 mGy/MBq). All patients tolerated the therapy without any acute adverse effects. Except for mild reversible xerostomia in 2 patients, no long-term side effects were observed. There was a small but statistically significant reduction in erythrocyte and leukocyte counts; only the reduction in erythrocyte counts decreased slightly below the reference range. No thrombocytopenia occurred. The severity of pain was significantly reduced in 2 of 6 patients (33.3%). A decrease in prostate-specific antigen levels was noted in 45 of 56 patients (80.4%). Of 25 patients monitored for at least 6 mo after 2 or more PSMA RLT cycles, a molecular response evaluation ((68)Ga-PSMA PET/CT) revealed partial remission in 14, stable disease in 2, and progressive disease in 9 patients. Contrast-enhanced CT revealed partial remission in 5, stable disease in 13, and progressive disease in 7 patients. The median progression-free survival was 13.7 mo, and the median overall survival was not reached during follow-up for 28 mo. PSMA RLT with (177)Lu-PSMA is feasible, safe, and effective in end-stage progressive mCRPC with appropriate

Computing row and column counts for sparse QR and LU factorization

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

Gilbert, John R.; Li, Xiaoye S.; Ng, Esmond G.

2001-01-01

We present algorithms to determine the number of nonzeros in each row and column of the factors of a sparse matrix, for both the QR factorization and the LU factorization with partial pivoting. The algorithms use only the nonzero structure of the input matrix, and run in time nearly linear in the number of nonzeros in that matrix. They may be used to set up data structures or schedule parallel operations in advance of the numerical factorization. The row and column counts we compute are upper bounds on the actual counts. If the input matrix is strong Hall and theremore » is no coincidental numerical cancellation, the counts are exact for QR factorization and are the tightest bounds possible for LU factorization. These algorithms are based on our earlier work on computing row and column counts for sparse Cholesky factorization, plus an efficient method to compute the column elimination tree of a sparse matrix without explicitly forming the product of the matrix and its transpose.« less

Contribution of Auger/conversion electrons to renal side effects after radionuclide therapy: preclinical comparison of (161)Tb-folate and (177)Lu-folate.

PubMed

Haller, Stephanie; Pellegrini, Giovanni; Vermeulen, Christiaan; van der Meulen, Nicholas P; Köster, Ulli; Bernhardt, Peter; Schibli, Roger; Müller, Cristina

2016-12-01

The radiolanthanide (161)Tb has, in recent years, attracted increasing interest due to its favorable characteristics for medical application. (161)Tb exhibits similar properties to the widely-used therapeutic radionuclide (177)Lu. In contrast to (177)Lu, (161)Tb yields a significant number of short-ranging Auger/conversion electrons (≤50 keV) during its decay process. (161)Tb has been shown to be more effective for tumor therapy than (177)Lu if applied using the same activity. The purpose of this study was to investigate long-term damage to the kidneys after application of (161)Tb-folate and compare it to the renal effects caused by (177)Lu-folate. Renal side effects were investigated in nude mice after the application of different activities of (161)Tb-folate (10, 20, and 30 MBq per mouse) over a period of 8 months. Renal function was monitored by the determination of (99m)Tc-DMSA uptake in the kidneys and by measuring blood urea nitrogen and creatinine levels in the plasma. Histopathological analysis was performed by scoring of the tissue damage observed in HE-stained kidney sections from euthanized mice. Due to the co-emitted Auger/conversion electrons, the mean absorbed renal dose of (161)Tb-folate (3.0 Gy/MBq) was about 24 % higher than that of (177)Lu-folate (2.3 Gy/MBq). After application of (161)Tb-folate, kidney function was reduced in a dose- and time-dependent manner, as indicated by the decreased renal uptake of (99m)Tc-DMSA and the increased levels of blood urea nitrogen and creatinine. Similar results were obtained when (177)Lu-folate was applied at the same activity. Histopathological investigations confirmed comparable renal cortical damage after application of the same activities of (161)Tb-folate and (177)Lu-folate. This was characterized by collapsed tubules and enlarged glomeruli with fibrin deposition in moderately injured kidneys and glomerulosclerosis in severely damaged kidneys. Tb-folate induced dose-dependent radionephropathy over

Multidose formulation of ready-to-use 177Lu-PSMA-617 in a centralized radiopharmacy set-up.

PubMed

Chakraborty, Sudipta; Vimalnath, K V; Chakravarty, Rubel; Sarma, H D; Dash, Ashutosh

2018-04-26

Lutetium-177-labeled PSMA inhibitor has emerged as a promising modality for targeted therapy of prostate carcinoma. A protocol for regular multidose formulation of ready-to-use 177 Lu-PSMA-617 has been developed based on detailed and systematic radiochemical investigations. The formulation meets the requirements of clinical use and can be shipped to nuclear medicine centres for administration up to 4 days from the date of formulation. The reported protocol would be useful toward facilitating widespread clinical utilization of 177 Lu-PSMA-617 in the management of prostate cancer. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of composition modulation on the luminescence properties of Eu(3+) doped Li1-xAgxLu(MoO4)2 solid-solution phosphors.

PubMed

Cheng, Fangrui; Xia, Zhiguo; Molokeev, Maxim S; Jing, Xiping

2015-11-07

Double molybdate scheelite-type solid-solution phosphors Li1-xAgxLu1-y(MoO4)2:yEu(3+) were synthesized by the solid state reaction method, and their crystal structures and luminescence properties were investigated in detail. The composition modulation and structural evolution of this series of samples were studied and the selected AgEu(MoO4)2, AgLu(MoO4)2, LiLu(MoO4)2 and LiEu(MoO4)2 phases were analyzed based on the Rietveld refinement. Depending on the variation of the Li/Ag ratio in Li1-xAgxLu1-y(MoO4)2:yEu(3+) phosphors, the difference in the luminescence properties of Li1-xAgxLu1-y(MoO4)2:yEu(3+) phosphors was ascribed to two factors, one reason could be assigned to the coupling effect and the nonradiative transition between the energy levels of LixAg1-xLu(MoO4)2 matrices and the activator Eu(3+), another could be due to the near ultraviolet energy absorption and transmission efficiency between the charge-transfer (CT) band of O(2-)-Mo(6+) and the 4f → 4f emissive transitions of Eu(3+). The ultraviolet-visible diffuse reflection spectra (UV-vis DRS) and Raman spectra analysis were also used to verify the above mechanism.

Small Volume Isotopic Analysis of Zircon Using LA-MC-ICP-MS U-Pb and Lu-Hf and Sub-ng Amounts of Hf in Solution

NASA Astrophysics Data System (ADS)

Bauer, A.; Horstwood, M. S.

2016-12-01

Crust-mantle evolution studies are greatly informed by zircon U-Pb and Lu-Hf isotopic datasets and the ease with which these data can now be acquired has seen their application become commonplace. In order to deconvolute geochemical change and interpret geologic variation in complexly zoned zircons, this information is most ideally obtained on the smallest volume of zircon by successive SIMS U-Pb and LA-MC-ICP-MS Lu-Hf isotopic analyses. However, due to variations in zircon growth zone geometry at depth, the Lu-Hf analysis may not relate to the lower volume U-Pb analysis, potentially causing inaccuracy of the resultant age-corrected Hf isotope signature. Laser ablation split-stream methods are applied to be certain that U-Pb and Lu-Hf data represent the same volume of zircon, however, the sampling volume remains relatively large at 40x30µm1. Coupled ID-TIMS U-Pb and solution MC-ICP-MS Lu-Hf work traditionally utilize whole-zircon dissolution ( 10-50ng Hf), which has the potential to homogenize different zones of geologic significance within an analysis. Conversely, modern ID-TIMS U-Pb methods utilize microsampling of zircon grains, often providing < 5ng Hf, thereby challenging conventional Lu-Hf acquisition protocols to achieve the required precision. In order to obtain usable precision on minimal zircon volumes, we developed laser ablation methods using successive 25um spot U-Pb and Lu-Hf ablation pits with a combined depth of 18um, and low-volume solution introduction methods without Hf-REE separation utilizing Hf amounts as low as 0.4ng, while retaining an uncertainty level of ca. 1 ɛHf for both methods. We investigated methods of Yb interference correction and the potential for matrix effects, with a particular focus on the accurate quantification of 176Lu/177Hf. These improvements reduce the minimum amount of material required for U-Pb and Hf isotopic analysis of zircon by about an order of magnitude. 1Ibanez-Mejia et al (2015). PreRes, 267, 285-310.

Comparison of the pressure dependences of Tc in the trivalent d -electron superconductors Sc, Y, La, and Lu up to megabar pressures

NASA Astrophysics Data System (ADS)

Debessai, M.; Hamlin, J. J.; Schilling, J. S.

2008-08-01

Whereas double hcp (dhcp) La superconducts at ambient pressure with Tc≃5K , the other trivalent d -electron metals Sc, Y, and Lu only superconduct if high pressures are applied. Earlier measurements of the pressure dependence of Tc for Sc and Lu metal are here extended to much higher pressures. Whereas Tc for Lu increases monotonically with pressure to 12.4 K at 174 GPa (1.74 Mbar), Tc for Sc reaches 19.6 K at 107 GPa, the second highest value observed for any elemental superconductor. At higher pressures a phase transition occurs whereupon Tc drops to 8.31 K at 111 GPa. The Tc(P) dependences for Sc and Lu are compared with those of Y and La. An interesting correlation is pointed out between the value of Tc and the fractional free volume available to the conduction electrons outside the ion cores, a quantity which is directly related to the number of d electrons in the conduction band.

Dosimetric analysis of 177Lu-DOTA-rituximab in patients with relapsed/refractory non-Hodgkin's lymphoma.

PubMed

Yadav, Madhav P; Singla, Suhas; Thakral, Parul; Ballal, Sanjana; Bal, Chandrasekhar

2016-07-01

Radioimmunotherapy targeting CD20 receptors in lymphoma using radiolabeled chimeric antibodies may lead to better therapeutic responses than cold anti-CD20 antibodies. This study aimed to assess the biodistribution and present reasonable estimates of normal organ doses, including red marrow using Lu-DOTA-rituximab. Patients with relapsed/refractory CD20+ B-cell non-Hodgkin's lymphoma were recruited into this prospective study. In-house labeling of Lu-DOTA-rituximab was performed and administered after quality assurance. Rituximab (375 mg/m), followed by 50 mCi (1850 MBq) of Lu-DOTA-rituximab was administered as a slow intravenous infusion and emission images were acquired. Regions of interest were drawn for kidney, liver, heart, bladder, spleen, and tumor lesions on both anterior and posterior images. Internal dose estimation was performed using OLINDA v1.0 software. The mean age of the 10 patients (eight men and two women) was 52±13 years. The uptake of radiolabeled antibody was visualized within 30 min of administration in the liver, kidneys, heart, spleen, and bladder. The coefficient of determination (R) was greater than 0.95 for organs and the whole body in all patients. The effective half-life of radioimmunoconjugate was 100±28 h (42-126 h). The critical organ in our study was the red marrow. The average total body dose, effective dose, and effective dose equivalent calculated in all 10 patients were 0.13±0.02, 0.15±0.03, and 0.22±0.04 mGy/MBq, respectively. There may be considerable interindividual differences in absorbed doses of organs and generalization or extrapolation of doses in the clinical setting at present is not feasible with Lu-DOTA-rituximab in non-Hodgkin's lymphoma patients. Patient-specific dosimetry is thus recommended to eliminate the variations and reduce the possibility of dose-limiting toxicity.

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

DOEpatents

Shah, Kanai S.

2007-02-06

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

Expedition Seven Science Officer Lu works with IRED hardware in Node 1/Unity

NASA Image and Video Library

2003-06-23

ISS007-E-08023 (23 June 2003) --- Astronaut Edward T. Lu, Expedition 7 NASA ISS science officer and flight engineer, performs maintenance on the Interim Resistive Exercise Device (IRED) Assembly in the Unity node on the International Space Station (ISS).

Generation of 2 µm Laguerre-Gaussian mode in a Tm:LuYAG solid-state laser

NASA Astrophysics Data System (ADS)

Liu, Qiyao; Ding, Manman; Zhao, Yongguang; Zhou, Wei; Shen, Deyuan

2018-04-01

In this article, we discuss the first vortex laser in the 2 µm spectral range directly generated from a Tm:LuYAG oscillator, in which a pump beam with annular intensity distribution is employed in line with Laguerre-Gaussian modes. Laser thresholds of different-order Laguerre-Gaussian modes are theoretically analyzed and discussed. Vortex lasers with orbital angular momentum of ħ and  -ħ were experimentally produced with corresponding output powers of 1.75 W and 1.64 W, respectively. This directly emitted vortex laser generated in the ~2 µm region from a compact and robust Tm:LuYAG oscillator has potential applications in the areas of molecular spectroscopy and organic material processing amongst others.

MS Lu conducts electrical work in Zvezda during STS-106

NASA Image and Video Library

2000-09-13

S106-E-5213 (13 September 2000) --- Astronaut Edward T. Lu follows printed guidelines as he assumes the role of an electrician onboard the Zvezda service module on the International Space Station (ISS). Electrical work was the hallmark of the day as four of the mission specialists aboard ISS (temporarily docked with the Space Shuttle Atlantis) replaced batteries inside the Zarya and Zvezda modules while supply transfer continued around them.

Reply to Comment by Lu et al. on "An Efficient and Stable Hydrodynamic Model With Novel Source Term Discretization Schemes for Overland Flow and Flood Simulations"

NASA Astrophysics Data System (ADS)

Xia, Xilin; Liang, Qiuhua; Ming, Xiaodong; Hou, Jingming

2018-01-01

This document addresses the comments raised by Lu et al. (2017). Lu et al. (2017) proposed an alternative numerical treatment for implementing the fully implicit friction discretization in Xia et al. (2017). The method by Lu et al. (2017) is also effective, but not necessarily easier to implement or more efficient. The numerical wiggles observed by Lu et al. (2017) do not affect the overall solution accuracy of the surface reconstruction method (SRM). SRM introduces an antidiffusion effect, which may also lead to more accurate numerical predictions than hydrostatic reconstruction (HR) but may be the cause of the numerical wiggles. As suggested by Lu et al. (2017), HR may perform equally well if fine enough grids are used, which has been investigated and recognized in the literature. However, the use of refined meshes in simulations will inevitably increase computational cost and the grid sizes as suggested are too small for real-world applications.

Stability analysis of a controlled mechanical system with parametric uncertainties in LuGre friction model

NASA Astrophysics Data System (ADS)

Sun, Yun-Hsiang; Sun, Yuming; Wu, Christine Qiong; Sepehri, Nariman

2018-04-01

Parameters of friction model identified for a specific control system development are not constants. They vary over time and have a significant effect on the control system stability. Although much research has been devoted to the stability analysis under parametric uncertainty, less attention has been paid to incorporating a realistic friction model into their analysis. After reviewing the common friction models for controller design, a modified LuGre friction model is selected to carry out the stability analysis in this study. Two parameters of the LuGre model, namely σ0 and σ1, are critical to the demonstration of dynamic friction features, yet the identification of which is difficult to carry out, resulting in a high level of uncertainties in their values. Aiming at uncovering the effect of the σ0 and σ1 variations on the control system stability, a servomechanism with modified LuGre friction model is investigated. Two set-point position controllers are synthesised based on the servomechanism model to form two case studies. Through Lyapunov exponents, it is clear that the variation of σ0 and σ1 has an obvious effect on the stabiltiy of the studied systems and should not be overlooked in the design phase.

External radiation exposure, excretion, and effective half-life in 177Lu-PSMA-targeted therapies.

PubMed

Kurth, J; Krause, B J; Schwarzenböck, S M; Stegger, L; Schäfers, M; Rahbar, K

2018-04-12

Prostate-specific membrane antigen (PSMA)-targeted therapy with 177 Lu-PSMA-617 is a therapeutic option for patients with metastatic castration-resistant prostate cancer (mCRPC). To optimize the therapy procedure, it is necessary to determine relevant parameters to define radiation protection and safety necessities. Therefore, this study aimed at estimating the ambient radiation exposure received by the patient. Moreover, the excreted activity was quantified. In total, 50 patients with mCRPC and treated with 177 Lu-PSMA-617 (mean administered activity 6.3 ± 0.5 GBq) were retrospectively included in a bi-centric study. Whole-body dose rates were measured at a distance of 2 m at various time points after application of 177 Lu-PSMA-617, and effective half-lives for different time points were calculated and compared. Radiation exposure to the public was approximated using the dose integral. For the estimation of the excreted activity, whole body measurements of 25 patients were performed at 7 time points. Unbound 177 Lu-PSMA-617 was rapidly cleared from the body. After 4 h, approximately 50% and, after 12 h, approximately 70% of the administered activity were excreted, primarily via urine. The mean dose rates were the following: 3.6 ± 0.7 μSv/h at 2 h p. i., 1.6 ± 0.6 μSv/h at 24 h, 1.1 ± 0.5 μSv/h at 48 h, and 0.7 ± 0.4 μSv/h at 72 h. The mean effective half-life of the cohort was 40.5 ± 9.6 h (min 21.7 h; max 85.7 h). The maximum dose to individual members of the public per treatment cycle was ~ 250 ± 55 μSv when the patient was discharged from the clinic after 48 h and ~ 190 ± 36 μSv when the patient was discharged after 72 h. In terms of the radiation exposure to the public, 177 Lu-PSMA is a safe option of radionuclide therapy. As usually four (sometimes more) cycles of the therapy are performed, it must be conducted in a way that ensures that applicable legal requirements can be followed. In

Biokinetics and dosimetry with 177Lu-DOTA-TATE in athymic mice with induced pancreatic malignant tumours

NASA Astrophysics Data System (ADS)

Rodríguez-Cortés, J.; de Murphy, C. Arteaga; Ferro-Flores, Ge; Pedraza-López, M.; Murphy-Stack, E.

Malignant pancreatic tumours induced in athymic mice are a good model for peptide receptor targeted radiotherapy. The objective of this research was to determine biokinetic parameters in mice, in order to estimate the induced pancreatic tumour absorbed doses and to evaluate an `in house' 177Lu-DOTA-TATE radiopharmaceutical as part of preclinical studies for targeted therapy in humans. AR42J murine pancreas cancer cells expressing somatostatin receptors, were implanted in athymic mice (nD22) to obtain biokinetic and dosimetric data of 177Lu-DOTA-TATE. The mean tumour uptake 2 h post injection was 14.76±1.9% I.A./g; kidney and pancreas uptake, at the same time, were 7.27±1.1% I.A./g (1.71±0.90%/organ) and 4.20±0.98% I.A./g (0.42±0.03%/organ), respectively. The mean absorbed dose to tumour, kidney and pancreas was 0.58±0.02 Gy/MBq; 0.23±0.01 Gy/MBq and 0.14±0.01 Gy/MBq, respectively. These studies justify further dosimetric estimations to ensure that 177Lu-DOTA-TATE will act as expected in humans.

Neutron scattering studies of the RENi 2B 2C (RE = Lu, Y, Ho, Er): Lattice dynamics

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

Bullock, Max

1998-02-23

The first chapter gives a brief overview of the system discussed in this dissertation. Chapters 2-5 and Appendix B of this dissertation consist of papers that are published, or have been submitted, which show experimental data regarding the phonon softening of LuNi 2B 2C. These papers have been removed and processed separately. Chapter 6 will contain a summary of the conclusions up to date. Appendix A will consist of a brief derivation of χ(q) which is talked about in the introduction of the dissertation. Appendix B will contain a Born-von Karman model fit to the experimental LuNi 2B 2C datamore » and a comparison with experimental data. Appendix C will contain a brief summary of the work done on LuNi 2B 2C as well as a complete listing of experimental data taken on the crystals which may be needed later for theoretical models of this system. Appendix D will outline a brief introduction covering some of the field theory used in the theoretical work for this thesis.« less

Simultaneous tri-wavelength laser operation at 916, 1086, and 1089 nm of diode-pumped Nd:LuVO4 crystal

NASA Astrophysics Data System (ADS)

Shen, Bingjun; Jin, Lihong; Zhang, Jiajia; Tian, Jian

2016-09-01

We report a diode-pumped continuous-wave tri-wavelength Nd:LuVO4 laser operating at 916, 1086, and 1089 nm. A theoretical analysis has been introduced to determine the threshold conditions for simultaneous tri-wavelength laser operation. Using a T-shaped cavity, we realized efficient tri-wavelength operation at 4F3/2  →  4I9/2 and 4F3/2  →  4I11/2 transitions for Nd:LuVO4 crystal, simultaneously. The maximum output power was 2.8 W, which included 916, 1086, and 1089 nm, and the optical conversion efficiency was 15.1%. To our knowledge, this is the first work that realizes simultaneous tri-wavelength Nd:LuVO4 laser operation.

An implict LU scheme for the Euler equations applied to arbitrary cascades. [new method of factoring

NASA Technical Reports Server (NTRS)

Buratynski, E. K.; Caughey, D. A.

1984-01-01

An implicit scheme for solving the Euler equations is derived and demonstrated. The alternating-direction implicit (ADI) technique is modified, using two implicit-operator factors corresponding to lower-block-diagonal (L) or upper-block-diagonal (U) algebraic systems which can be easily inverted. The resulting LU scheme is implemented in finite-volume mode and applied to 2D subsonic and transonic cascade flows with differing degrees of geometric complexity. The results are presented graphically and found to be in good agreement with those of other numerical and analytical approaches. The LU method is also 2.0-3.4 times faster than ADI, suggesting its value in calculating 3D problems.

Transculturation of Madness: The Double Origin of Lu Xun's "Diary of a Madman".

PubMed

Ma, Xiaolu

2015-01-01

Over the years scholars have examined the allegorical features of the depiction of madness in Lu Xun's "Diary of a Madman," yet to date little research has taken into consideration the intercultural angle embedded in the narrative's intersection of three cultures, namely Russian, Japanese and Chinese. This paper traces the European-Japanese-Sino route of modern neologisms of madness to explore the introduction of such neologisms into the modern Chinese language and how it corresponds with changing patterns of knowledge and power. I use my study of transculturation on the macro scale to frame a reexamination of the lexicon in "Diary of a Madman." I focus especially on kuangren and pohaikuang, the two key words employed by Lu Xun, to see how they contribute to the ambiguity in his attitude towards the power struggle between the East and the West, the old and the new.

Jahn-Teller versus quantum effects in the spin-orbital material LuVO 3

DOE PAGES

Skoulatos, M.; Toth, S.; Roessli, B.; ...

2015-04-13

In this article, we report on combined neutron and resonant x-ray scattering results, identifying the nature of the spin-orbital ground state and magnetic excitations in LuVO 3 as driven by the orbital parameter. In particular, we distinguish between models based on orbital-Peierls dimerization, taken as a signature of quantum effects in orbitals, and Jahn-Teller distortions, in favor of the latter. In order to solve this long-standing puzzle, polarized neutron beams were employed as a prerequisite in order to solve details of the magnetic structure, which allowed quantitative intensity analysis of extended magnetic-excitation data sets. The results of this detailed studymore » enabled us to draw definite conclusions about the classical versus quantum behavior of orbitals in this system and to discard the previous claims about quantum effects dominating the orbital physics of LuVO 3 and similar systems.« less

Role of protein farnesylation events in the ABA-mediated regulation of the Pinoresinol-Lariciresinol Reductase 1 (LuPLR1) gene expression and lignan biosynthesis in flax (Linum usitatissimum L.).

PubMed

Corbin, Cyrielle; Decourtil, Cédric; Marosevic, Djurdjica; Bailly, Marlène; Lopez, Tatiana; Renouard, Sullivan; Doussot, Joël; Dutilleul, Christelle; Auguin, Daniel; Giglioli-Guivarc'h, Nathalie; Lainé, Eric; Lamblin, Frédéric; Hano, Christophe

2013-11-01

A Linum usitatissimum LuERA1 gene encoding a putative ortholog of the ERA1 (Enhanced Response to ABA 1) gene of Arabidopsis thaliana (encoding the beta subunit of a farnesyltransferase) was analyzed in silico and for its expression in flax. The gene and the protein sequences are highly similar to other sequences already characterized in plants and all the features of a farnesyltransferase were detected. Molecular modeling of LuERA1 protein confirmed its farnesyltransferase nature. LuERA1 is expressed in the vegetative organs and also in the outer seedcoat of the flaxseed, where it could modulate the previously observed regulation operated by ABA on lignan synthesis. This effect could be mediated by the regulation of the transcription of a key gene for lignan synthesis in flax, the LuPLR1 gene, encoding a pinoresinol lariciresinol reductase. The positive effect of manumycin A, a specific inhibitor of farnesyltransferase, on lignan biosynthesis in flax cell suspension systems supports the hypothesis of the involvement of such an enzyme in the negative regulation of ABA action. In Arabidopsis, ERA1 is able to negatively regulate the ABA effects and the mutant era1 has an enhanced sensitivity to ABA. When expressed in an Arabidopsis cell suspension (heterologous system) LuERA1 is able to reverse the effect of the era1 mutation. RNAi experiments in flax targeting the farnesyltransferase β-subunit encoded by the LuERA1 gene led to an increase LuPLR1 expression level associated with an increased content of lignan in transgenic calli. Altogether these results strongly suggest a role of the product of this LuERA1 gene in the ABA-mediated upregulation of lignan biosynthesis in flax cells through the activation of LuPLR1 promoter. This ABA signaling pathway involving ERA1 probably acts through the ABRE box found in the promoter sequence of LuPLR1, a key gene for lignan synthesis in flax, as demonstrated by LuPLR1 gene promoter-reporter experiments in flax cells using wild

Evaluation of 177Lu[Lu]-CHX-A″-DTPA-6A10 Fab as a radioimmunotherapy agent targeting carbonic anhydrase XII.

PubMed

Fiedler, L; Kellner, M; Gosewisch, A; Oos, R; Böning, G; Lindner, S; Albert, N; Bartenstein, P; Reulen, H-J; Zeidler, R; Gildehaus, F J

2018-05-01

Due to their infiltrative growth behavior, gliomas have, even after surgical resection, a high recurrence tendency. The approach of intracavitary radioimmunotherapy (RIT) is aimed at inhibiting tumor re-growth by directly administering drugs into the resection cavity (RC). Direct application of the radioconjugate into the RC has the advantage of bypassing the blood-brain barrier, which allows the administration of higher radiation doses than systemic application. Carbonic anhydrase XII (CA XII) is highly expressed on glioma cells while being absent from normal brain and thus an attractive target molecule for RIT. We evaluated a CA XII-specific 6A10 Fab (fragment antigen binding) labelled with 177 Lu as an agent for RIT. 6A10 Fab fragment was modified and radiolabelled with 177 Lu and characterized by MALDI-TOF, flow cytometry and radio-TLC. In vitro stability was determined under physiological conditions. Biodistribution studies, autoradiography tumor examinations and planar scintigraphy imaging were performed on SCID-mice bearing human glioma xenografts. The in vitro CA XII binding capacity of the modified Fab was confirmed. Radiochemical purity was determined to be >90% after 72 h of incubation under physiological conditions. Autoradiography experiments proved the specific binding of the Fab to CA XII on tumor cells. Biodistribution studies revealed a tumor uptake of 3.0%ID/g after 6 h and no detectable brain uptake. The tumor-to-contralateral ratio of 10/1 was confirmed by quantitative planar scintigraphy. The radiochemical stability in combination with a successful in vivo tumor uptake shows the potential suitability for future RIT applications with the 6A10 Fab. Copyright © 2018 Elsevier Inc. All rights reserved.

Strain dynamics during La{sub 2}O{sub 3}/Lu{sub 2}O{sub 3} superlattice and alloy formation

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

Proessdorf, André; Niehle, Michael; Grosse, Frank

The dynamics of strain relaxation and intermixing during molecular beam epitaxy of La{sub 2}O{sub 3} and Lu{sub 2}O{sub 3} superlattices and alloys consisting of both binaries on Si(111) have been studied by real-time in situ grazing incidence x-ray diffraction and high resolution transmission electron microscopy. The presence of both hexagonal and cubic polymorphs of La{sub 2}O{sub 3} influences the epitaxial formation within the superlattice. The process of strain relaxation is closely related to the presence of a (La,Lu){sub 2}O{sub 3} alloy adopting a cubic symmetry. It is formed by interdiffusion of La and Lu atoms reducing internal lattice mismatch withinmore » the superlattice. An interface thickness dominated by interdiffusion regions of about 3 monolayers is determined by high-angle annular dark field scanning transmission electron microscopy.« less

Effects of scandium substitution on the crystal structure and luminescence properties of LuBO{sub 3}: Ce{sup 3+}

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

Wu, Yuntao, E-mail: caswyt@hotmail.com; Ren, Guohao, E-mail: rgh@mail.sic.ac.cn; Ding, Dongzhou

2012-10-15

The calcite phase of LuBO{sub 3} and ScBO{sub 3} polycrystalline powders were synthesized by solid state reaction method, and the Lu{sub 1-x}Sc{sub x}BO{sub 3}:Ce (x=0.2, 0.5, 0.7) single crystals were grown by the Czochralski method. A large composition deviation between the initial polycrystalline powders and final single crystal was confirmed by electron probe micro-analysis. Raman spectroscopy revealed that moderate lattice disorder was induced by scandium substitution. However, based on the single crystal X-ray study, we finally concluded that the crystal structure of lutetium scandium orthoborate still crystallized in the rhombohedral system belonging to R3{sup -}c. Furthermore, the relationship between themore » energies of the five 5d levels of Ce{sup 3+} and the crystalline environment was revealed. The total redshift, total crystal field splitting, and centroid shift of Lu{sub 1-x}Sc{sub x}BO{sub 3}:Ce{sup 3+} were calculated based on their VUV excitation spectra. The variations trend of these observed spectroscopic parameters was in accordance with the predicted ones. - Graphical abstract: The crystal structure of Lu{sub 1-x}Sc{sub x}BO{sub 3}:Ce is rhombohedral system with R3{sup -}c space group. The relationship between the energies of the five Ce{sup 3+} 5d levels and the crystalline environment is established. Highlights: Black-Right-Pointing-Pointer Moderate lattice disorder is induced by scandium doping. Black-Right-Pointing-Pointer The crystal structure of Lu{sub 1-x}Sc{sub x}BO{sub 3}:Ce is rhombohedral system with R3{sup -}c space group. Black-Right-Pointing-Pointer Relationship between energies of Ce{sup 3+} 5d levels and crystalline environment is established. Black-Right-Pointing-Pointer The spectroscopic parameters are experimentally and theoretically calculated.« less

Multi-zonal Navier-Stokes code with the LU-SGS scheme

NASA Technical Reports Server (NTRS)

Klopfer, G. H.; Yoon, S.

1993-01-01

The LU-SGS (lower upper symmetric Gauss Seidel) algorithm has been implemented into the Compressible Navier-Stokes, Finite Volume (CNSFV) code and validated with a multizonal Navier-Stokes simulation of a transonic turbulent flow around an Onera M6 transport wing. The convergence rate and robustness of the code have been improved and the computational cost has been reduced by at least a factor of 2 over the diagonal Beam-Warming scheme.

Efficient Operation of Conductively Cooled Ho:Tm:LuLiF Laser Oscillator/Amplifier

NASA Technical Reports Server (NTRS)

Yu, Jirong; Bai, Yingxin; Trieu, Bo; Petros, M.; Petzar, Paul; Lee, Hyung; Singh, U.

2008-01-01

A conductively-cooled Ho:Tm:LuLiF laser oscillator generates 1.6J normal mode pulses at 10Hz with optical to optical efficiency of 20%. When the laser head module is used as the amplifier, the double-pass small-signal amplification excesses 25.

Structural, electronic and magnetic properties of layered REB{sub 2}C compounds (RE=Dy, Tm, Lu)

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

Babizhetskyy, Volodymyr, E-mail: v.babizhetskyy@googlemail.com; Department of Inorganic Chemistry, Ivan Franko National University of L'viv, Kyryla and Mefodiya Str. 6, UA-79005 Lviv; Simon, Arndt

2012-07-15

The crystal structure of LuB{sub 2}C has been determined from single crystal and powder X-ray diffraction data. It crystallizes in the orthorhombic space group Pbam (a=6.7429(1) A, b=6.7341(1) A, c=3.5890(1) A, Z=4, R1=0.024 (wR2=0.059) for 436 reflections with I{sub o}>2{sigma}(I{sub o})). The compounds REB{sub 2}C (RE=Y, Tb-Lu) are isotypic. The boron and carbon atoms form infinite, planar two-dimensional nets which alternate with sheets of rare-earth metal atoms. Inside the nonmetal atom nets, a coloring with fused B{sub 2}C{sub 2} rhombuses and B{sub 5}C{sub 2} heptagons is proposed, supported by NMR experiments and density functional theory calculations. The calculated density ofmore » states of LuB{sub 2}C indicates this compound to be metallic. The magnetic properties of the isotypic compound TmB{sub 2}C, has been measured in the temperature range 2 K3 T a metamagnetic transition is encountered. The temperature dependence of the electrical resistivity proves the metallic character of the TmB{sub 2}C compound as well as the AFM ordering. - Graphical abstract: The crystal structure of LuB{sub 2}C has been determined from single crystal and powder X-ray diffraction data. It crystallizes in the orthorhombic space group Pbam. The compounds REB{sub 2}C (RE=Y, Tb-Lu) are isotypic. The boron and carbon atoms form infinite, planar two-dimensional nets which alternate with sheets of rare-earth metal atoms. Inside the nonmetal atom nets, a coloring with fused B{sub 2}C{sub 2} rhombuses and B{sub 5}C{sub 2} heptagons is proposed, supported by NMR experiments and density functional theory calculations. The magnetic properties of the isotypic compound TmB{sub 2}C, has been measured in the temperature range 2 K3 T a metamagnetic transition is encountered. The temperature dependence of the electrical resistivity proves the metallic character of the TmB{sub 2}C compound as well as the AFM ordering. Highlights: Black-Right-Pointing-Pointer LuB{sub 2}C compound crystallizes

Mechanisms of Cell Killing Response from Low Linear Energy Transfer (LET) Radiation Originating from 177Lu Radioimmunotherapy Targeting Disseminated Intraperitoneal Tumor Xenografts

PubMed Central

Yong, Kwon Joong; Milenic, Diane E.; Baidoo, Kwamena E.; Brechbiel, Martin W.

2016-01-01

Radiolabeled antibodies (mAbs) provide efficient tools for cancer therapy. The combination of low energy β−-emissions (500 keVmax; 130 keVave) along with a γ-emission for imaging makes 177Lu (T1/2 = 6.7 day) a suitable radionuclide for radioimmunotherapy (RIT) of tumor burdens possibly too large to treat with α-particle radiation. RIT with 177Lu-trastuzumab has proven to be effective for treatment of disseminated HER2 positive peritoneal disease in a pre-clinical model. To elucidate mechanisms originating from this RIT therapy at the molecular level, tumor bearing mice (LS-174T intraperitoneal xenografts) were treated with 177Lu-trastuzumab comparatively to animals treated with a non-specific control, 177Lu-HuIgG, and then to prior published results obtained using 212Pb-trastuzumab, an α-particle RIT agent. 177Lu-trastuzumab induced cell death via DNA double strand breaks (DSB), caspase-3 apoptosis, and interfered with DNA-PK expression, which is associated with the repair of DNA non-homologous end joining damage. This contrasts to prior results, wherein 212Pb-trastuzumab was found to down-regulate RAD51, which is involved with homologous recombination DNA damage repair. 177Lu-trastuzumab therapy was associated with significant chromosomal disruption and up-regulation of genes in the apoptotic process. These results suggest an inhibition of the repair mechanism specific to the type of radiation damage being inflicted by either high or low linear energy transfer radiation. Understanding the mechanisms of action of β−- and α-particle RIT comparatively through an in vivo tumor environment offers real information suitable to enhance combination therapy regimens involving α- and β−-particle RIT for the management of intraperitoneal disease. PMID:27196891

Stellar Neutron Capture Cross Sections of the Lu and Hf Isotopes

NASA Astrophysics Data System (ADS)

Wisshak, K.; Voss, F.; Käppeler, F.; Kazakov, L.; Krtička, M.

2005-05-01

The neutron capture cross sections of 175,176Lu and 176,177,178,179,180Hf have been measured in the energy range from 3 to 225 keV at the Karlsruhe 3.7 MV Van de Graaff accelerator relative to the gold standard. Neutrons were produced by the 7Li(p,n)7Be reaction and capture events were detected by the Karlsruhe 4πBaF2 detector. The cross section ratios could be determined with uncertainties between 0.9 and 1.8% about a factor of five more accurate than previous data. A strong population of isomeric states was found in neutron capture of the Hf isotopes, which are only partially explained by CASINO/GEANT simulations based on the known level schemes. Maxwellian averaged neutron capture cross sections were calculated for thermal energies between kT = 8 keV and 100 keV. Severe differences up to40% were found to the data of a recent evaluation based on existing experimental results. The new data allow for a much more reliable analysis of the important branching in the s-process synthesis path at 176Lu which can be interpreted as an s-process thermometer.

1.88 Micrometers InGaAsP Pumped, Room Temperature Ho: LuAG Laser

NASA Technical Reports Server (NTRS)

Barnes, Norman P.; Amzajerdian, Farzin; Reichle, Donald J.; Busch, George; Leisher, Paul

2009-01-01

A room temperature, directly diode pumped Ho:LuAG laser oscillated for the first time. Direct pumping of the Ho upper laser manifold maximizes efficiency, minimizes heating, and eliminates Ho:Tm energy sharing. Design and performance are presented.

Electronic structure, optical and thermal/concentration quenching properties of Lu{sub 2−2x}Eu{sub 2x}WO{sub 6} (0 ≤ x ≤0.2)

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

Chen, Xiang-Yang; University of Chinese Academy of Science, Beijing 100039; Zhang, Zhi-Jun, E-mail: zhangzhijun@shu.edu.cn

Highlights: • The band gap of Lu{sub 2}WO{sub 6} is calculated to be 3.13 eV using the CASTEP mode. • Valent state and occupation site of Eu are clarified by X-ray absorption fine structure (XAFS) spectra. • The thermal/concentration quenching mechanisms of Eu in Lu{sub 2}WO{sub 6} have been investigated in detail. - Abstract: Density functional theory calculations on monoclinic Lu{sub 2}WO{sub 6} is carried out using the Cambridge Sequential Total Energy Package code. The result indicates that Lu{sub 2}WO{sub 6} is a broad band gap semiconductor with an indirect band gap of 3.13 eV. Eu ions are trivalency and themore » average coordination number is 7.6(5), indicating that the site of Lu is occupied by Eu. The activation energy ΔE is calculated as 0.314 eV. In addiation, the thermal quenching mechnism of Eu-activated Lu{sub 2}WO{sub 6} and the different concentration quenching mechanisms for {sup 5}D{sub 0} and {sup 5}D{sub 1} emissions of Eu ions have been proposed.« less

[Comparison of academic viewpoints between Yun Tie-qiao and Lu Yuan-lei].

PubMed

Yang, Zhi-qing; Bi, Li-juan; Yang, Xing-lin

2010-07-01

Both Yun Tie-qiao and Lu Yuan-lei are medical professionals coming from the literary field with versatile and in-depth knowledge and extensive experience in medical education and clinical practice, all closely related to modern TCM development. Yun, the elder, insisted on reforming TCM and was early to advocate the academic idea of amalgamating western and traditional Chinese medicine; while Lu, the younger, insisted on the idea of "scientizing TCM" and was the representative of amalgamating western and traditional Chinese medicine in the later stage. They shared many common viewpoints, including venerating Zhang Zhongjing, stressing exogenous cold pathogens, advocating reformation and amalgamation of western medicine and TCM and objecting to the abolishment of TCM. However, there were discrepancies between them, including the relationship between the Inner Canon and the Essay on Exogenous Cold Diseases, warm disease theory, pulse theory, titles of TCM diseases and Japanese Kampo medicine. A comparison of them and noting their valuable contributions will be beneficial for the promotion of the development of TCM.

Transparent Lu 2 O 3 :Eu ceramics by sinter and HIP optimization

NASA Astrophysics Data System (ADS)

Seeley, Z. M.; Kuntz, J. D.; Cherepy, N. J.; Payne, S. A.

2011-09-01

Evolution of porosity and microstructure was observed during densification of lutetium oxide ceramics doped with europium (Lu 2O 3:Eu) fabricated via vacuum sintering and hot isostatic pressing (HIP'ing). Nano-scale starting powder was uniaxially pressed and sintered under high vacuum at temperatures between 1575 and 1850 °C to obtain densities ranging between 94% and 99%, respectively. Sintered compacts were then subjected to 200 MPa argon gas at 1850 °C to reach full density. Vacuum sintering above 1650 °C led to rapid grain growth prior to densification, rendering the pores immobile. Sintering between 1600 and 1650 °C resulted in closed porosity yet a fine grain size to allow the pores to remain mobile during the subsequent HIP'ing step, resulting in a fully-dense highly transparent ceramic without the need for subsequent air anneal. Light yield performance was measured and Lu 2O 3:Eu showed ˜4 times higher light yield than commercially used scintillating glass indicating that this material has the potential to improve the performance of high energy radiography devices.

Mantle evolution on Mars: Constraints from Lu-Hf and Sm-Nd isotope systematics of SNC meteorites

NASA Astrophysics Data System (ADS)

Scherer, E. E.; Kurahashi, E.; Mezger, K.

2012-12-01

The long-lived 176Lu-176Hf and 147Sm-143Nd isotope systems are commonly employed to track the evolution of complementary mantle and crust reservoirs. The four elements involved are refractory and lithophile, and thus their relative abundances are not expected to have been changed by accretion or core formation. Subsequent silicate differentiation processes, however, e.g., the formation of crust by extraction of melts from the mantle, will fractionate Lu/Hf and Sm/Nd. This typically leaves a depleted mantle with higher Lu/Hf and Sm/Nd values than those of the undifferentiated, presumably chondritic parental reservoir. On the other hand, these same values in crustal rocks tend to be lower than those of their source. (Apparent exceptions are the Martian shergottites, which tend to have lower Lu/Hf as expected, but Sm/Nd higher than their presumed sources. Such decoupling of the two isotope systems may be explained by two-stage melting [e.g., 1, 5].) The ensuing chemical variability among secondary and later generation silicate reservoirs causes their isotopic compositions (e.g., 176Hf/177Hf and 143Nd/144Nd) to diverge from that of the bulk silicate planet over hundreds of millions of years. The resulting isotopic diversity preserved (SNC) meteorites is being used to constrain the differentiation history, melting mineralogy, and dynamics of the Martian mantle [e.g., 1-8]. However, interpretations based on the initial isotope compositions of Hf and Nd strongly depend on the accuracy of crystallization ages. The ages of shergottites in particular are debated (e.g., [3,4,7]). To resolve this issue and gain a better understanding of Martian mantle evolution, we are investigating the Lu-Hf and Sm-Nd systematics of bulk SNC meteorites and constructing internal (mineral) isochrons. Eleven bulk Martian meteorites (5 shergottites, 4 nakhlites, and 2 chassignites) were digested without prior leaching in high-pressure autoclaves for 5 days. Initial ɛ176Hf and ɛ143Nd values

A WLED based on LuAG:Ce3+ PiG coated red-emitting K2SiF6:Mn4+ phosphor by screen-printing

NASA Astrophysics Data System (ADS)

Cao, Rui; Wu, Lingchao; Di, Xiaoxuan; Li, Pengzhi; Hu, Guangcai; Liang, Xiaojuan; Xiang, Weidong

2017-08-01

It is high-profile that the use of phosphor-in-glass (PiG) is extensive because of its excellent advantages in thermal resistance and lifetime aspects, and so on. Here, white light-emitting diodes (WLED) based on LuAG:Ce3+ PiG coated red-emitting K2SiF6:Mn4+ (KSF) phosphors by screen-printing are fabricated. Among all of these, the commercial LuAG phosphors and glass raw materials of TeO2-based glass, were weighted and milled in an agate thoroughly. Then, the mixture was melted and sintered at 850 K or so for 20 min in the ambient atmosphere through low temperature co-fired method, cold-forming LuAG PiG clump and cut into different LuAG PiG thicknesses. After that, the commercial red phosphor KSF was coated on LuAG PiG by screen-printing technique. Finally, high-performance WLEDs based on the TeO2-based glass were obtained, tested and characterized, which exhibit a highest color rendering index of 94.1, a lowest color temperature of 3744 K and a largest luminous efficiency of 101.02 lm·W-1. Most noticeably of all, the promising method has excellent developing potential for industrialization in high-power WLED.

How deformed are the TSD bands in odd Lu isotopes?

NASA Astrophysics Data System (ADS)

Ragnarsson, I.

2017-12-01

The experimental fingerprints for large deformation in the triaxial strongly deformed (TSD) bands of 163,165,167Lu are discussed. It is argued that these fingerprints are not very convincing. On the contrary, especially the fact that there exist strong interactions between the TSD bands and normal-deformed (ND) bands indicates that the deformation of the TSD bands cannot be very different from that of the ND bands. The need for detailed new experimental data is underlined.

Microbial Diversity Analysis of Fermented Mung Beans (Lu-Doh-Huang) by Using Pyrosequencing and Culture Methods

PubMed Central

Chao, Shiou-Huei; Huang, Hui-Yu; Chang, Chuan-Hsiung; Yang, Chih-Hsien; Cheng, Wei-Shen; Kang, Ya-Huei; Watanabe, Koichi; Tsai, Ying-Chieh

2013-01-01

In Taiwanese alternative medicine Lu-doh-huang (also called Pracparatum mungo), mung beans are mixed with various herbal medicines and undergo a 4-stage process of anaerobic fermentation. Here we used high-throughput sequencing of the 16S rRNA gene to profile the bacterial community structure of Lu-doh-huang samples. Pyrosequencing of samples obtained at 7 points during fermentation revealed 9 phyla, 264 genera, and 586 species of bacteria. While mung beans were inside bamboo sections (stages 1 and 2 of the fermentation process), family Lactobacillaceae and genus Lactobacillus emerged in highest abundance; Lactobacillus plantarum was broadly distributed among these samples. During stage 3, the bacterial distribution shifted to family Porphyromonadaceae, and Butyricimonas virosa became the predominant microbial component. Thereafter, bacterial counts decreased dramatically, and organisms were too few to be detected during stage 4. In addition, the microbial compositions of the liquids used for soaking bamboo sections were dramatically different: Exiguobacterium mexicanum predominated in the fermented soybean solution whereas B. virosa was predominant in running spring water. Furthermore, our results from pyrosequencing paralleled those we obtained by using the traditional culture method, which targets lactic acid bacteria. In conclusion, the microbial communities during Lu-doh-huang fermentation were markedly diverse, and pyrosequencing revealed a complete picture of the microbial consortium. PMID:23700436

The radiometal makes a difference. Synthesis and preliminary characterisation of DOTA-minigastrin analogue complexes with Ga, Lu and Y.

PubMed

Maurin, Michał; Garnuszek, Piotr; Baran, Piotr; Pawlak, Dariusz; Mikołajczak, Renata

2015-01-01

The minigastrin analogue - CP04: DOTA-(DGlu)6-Ala-Tyr-Gly-Trp-Met-Asp-Phe-NH2 has been developed for CCK2R targeting. This analogue can be radiolabelled with 111In or 68Ga for imaging, or with 90Y and 177Lu for therapy. However, affinity of the chelator-peptide conjugates to the cell membrane receptors may vary depending on the metal incorporated into the complex. So far, there are no such studies for the ligands of gastrin/cholecystokinin receptor CCK2R. It is supposed that the reason for the differentiation of receptor affinity to the respective receptors is in the changes of structure of chelating system and their influence on the bioactive conformations of the metal conjugated peptides. Herein, we report on the radiolabeling of CP04 with 90Y, 177Lu and 68Ga and synthesis of cold CP04 complexes with respective stable metals for further structural and physico-chemical and biological studies. From 200 to 600 MBq of 90Y, 177Lu or 68Ga were used for radiolabelling of 20 μg of CP04 dissolved in ascorbic acid solution (50 mg/mL, pH 4.5). Non-radioactive complexes with Lu and Ga were synthesized in milligram amounts starting from 0.5 mg up to 5 mg of CP04 dissolved in ascorbic acid solution (50 mg/mL, pH 4.5) when using 2-molar excess of the metal ions. Complex formation needed 5 min in microwave oven or 12 min in thermo-block at 95°C. RP-HPLC isocratic method (Kinetex 150/4.6 mm; 25% AcN/0.1% TFA, 1 mL/min) with UV/Vis and radiometric detection was developed for investigation of the radiolabelled and "cold" complexes. For LC-MS investigations, HPLC method was modified replacing TFA by formic acid. Yields of CP04 radiolabelling were greater than 90% for all three radionuclides. The HPLC method enabled identification of these radio-complexes based on comparison to their non-radioactive equivalents. In all cases, chromatograms revealed peaks that could be attributed to the metal-CP04 complexes and to impurities (including methionine oxidation). LC-MS analysis of Ga and

Lu-Hf Garnet Geochronology Reveals the Tectonic History of Precambrian Rocks in the Southern Rocky Mountains

NASA Astrophysics Data System (ADS)

Aronoff, R.; Andronicos, C.; Vervoort, J. D.; Hunter, R. A.

2014-12-01

Lu-Hf garnet dating of Proterozoic rocks of the southwestern United States provides constraints on the timing and geographic extent of metamorphism associated with the Yavapai, Mazatzal, and newly recognized Picuris orogenies. Prior work focusing on U-Pb dating of plutons and Ar geochronology has left the timing of prograde metamorphism ambiguous, particularly in northern New Mexico and southern Colorado. Because the Lu-Hf system dates the onset of garnet growth, it can constrain the timing of the prograde P-T path. Garnet schist samples from central and northern New Mexico exhibit garnet growth restricted to the time period between ~1460 and 1400 Ma. In the Picuris and Manzano mountains, the oldest Lu-Hf garnet ages predate the U-Pb ages of ~1.4 Ga plutons located near the dated samples. This implies that garnet growth, and therefore the onset of amphibolite facies metamorphism, cannot be driven by contact metamorphism, as has been previously inferred. Garnet-bearing samples from the Needle and Wet Mountains in southern Colorado display a range of garnet ages between ~1750 and 1470 Ma. A garnet gneiss from the Needle Mountains in southwestern Colorado yields an age of 1748 Ma, which is consistent with the Yavapai orogeny. This Lu-Hf garnet age has not been reset by contact metamorphism associated with the emplacement of the ~1.4 Ga Eolus batholith. Anatectic garnet in an orthogneiss from the northern Wet Mountains yields an age of 1601 Ma and is interpreted to date partial melting at the close of the Mazatzal orogeny. A 1476 Ma garnet age from the aureole of the 1440 Ma Oak Creek pluton is interpreted to date upper amphibolite facies metamorphism. The age distribution of these samples shows that rocks in Colorado underwent a complex, poly-metamorphic history, while rocks in New Mexico underwent a single progressive metamorphic event. This contrast implies that the boundary between rocks deformed and metamorphosed during the ~1800-1600 Ma Yavapai and Mazatzal

Laser performance of in-band pumped Er : LiYF4 and Er : LiLuF4 crystals

NASA Astrophysics Data System (ADS)

Gorbachenya, K. N.; Kurilchik, S. V.; Kisel, V. E.; Yasukevich, A. S.; Kuleshov, N. V.; Nizamutdinov, A. S.; Korableva, S. L.; Semashko, V. V.

2016-02-01

Spectroscopic properties of Er : LiLuF4 and Er : LiYF4 crystals in the spectral region near 1.5 μm and the lasing characteristics of these crystals under in-band pumping at a wavelength of 1522 nm are studied. With the Er : LiLuF4 crystal, the maximum slope efficiency with respect to the absorbed pump power was 44% at a wavelength of 1609 nm. Continuous-wave operation of an inband pumped Er : LiYF4 laser is obtained for the first time. The output power at a wavelength of 1606 nm was 58 mW with a slope efficiency of 21%.

First principle study of AlX (X=3d, 4d, 5d elements and Lu) dimer.

PubMed

Ouyang, Yifang; Wang, Jianchuan; Hou, Yuhua; Zhong, Xiaping; Du, Yong; Feng, Yuanping

2008-02-21

The ground state equilibrium bond length, harmonic vibrational frequency, and dissociation energy of AlX (X=3d,4d,5d elements and Lu) dimers are investigated by density functional method B3LYP. The present results are in good agreement with the available experimental and other theoretical values except the dissociation energy of AlCr. The present calculations show that the late transition metal can combine strongly with aluminum compared with the former transition metal. The present calculation also indicates that it is more reasonable to replace La with Lu in the Periodic Table and that the bonding strengths of zinc, cadmium, and mercury with aluminum are very weak.

Luminescence and energy transfer in Lu3Al5O12 scintillators co-doped with Ce3+ and Tb3+.

PubMed

Ogiegło, Joanna M; Zych, Aleksander; Ivanovskikh, Konstantin V; Jüstel, Thomas; Ronda, Cees R; Meijerink, Andries

2012-08-23

Lu(3)Al(5)O(12) (LuAG) doped with Ce(3+) is a promising scintillator material with a high density and a fast response time. The light output under X-ray or γ-ray excitation is, however, well below the theoretical limit. In this paper the influence of codoping with Tb(3+) is investigated with the aim to increase the light output. High resolution spectra of singly doped LuAG (with Ce(3+) or Tb(3+)) are reported and provide insight into the energy level structure of the two ions in LuAG. For Ce(3+) zero-phonon lines and vibronic structure are observed for the two lowest energy 5d bands and the Stokes' shift (2 350 cm(-1)) and Huang-Rhys coupling parameter (S = 9) have been determined. Tb(3+) 4f-5d transitions to the high spin (HS) and low spin (LS) states are observed (including a zero-phonon line and vibrational structure for the high spin state). The HS-LS splitting of 5400 cm(-1) is smaller than usually observed and is explained by a reduction of the 5d-4f exchange coupling parameter J by covalency. Upon replacing the smaller Lu(3+) ion with the larger Tb(3+) ion, the crystal field splitting for the lowest 5d states increases, causing the lowest 5d state to shift below the (5)D(4) state of Tb(3+) and allowing for efficient energy transfer from Tb(3+) to Ce(3+) down to the lowest temperatures. Luminescence decay measurements confirm efficient energy transfer from Tb(3+) to Ce(3+) and provide a qualitative understanding of the energy transfer process. Co-doping with Tb(3+) does not result in the desired increase in light output, and an explanation based on electron trapping in defects is discussed.

The feasibility study of 177Lu production in Miniature Neutron Source Reactors using a multi-stage approach in Isfahan, Iran.

PubMed

Golabian, A; Hosseini, M A; Ahmadi, M; Soleimani, B; Rezvanifard, M

2018-01-01

Miniature neutron source reactors (MNSRs) are among the safest and economic research reactors with potentials to be used for neutron studies. This manuscript explores the feasibility of 177 Lu production in Isfahan MNSR reactor using direct production route. In this study, to assess the specific activity of the produced radioisotope, a simulation was carried out through the MCNPX2.6 code. The simulation was validated by irradiating a lutetium disc-like (99.98 chemical purity) at the thermal neutron flux of 5 × 10 11 ncm 2 s -1 and an irradiation time of 4min. After the spectrometry of the irradiated sample, the experimental results of 177 Lu production were compared with the simulation results. In addition, factor from the simulation was extracted by replacing it in the related equations in order to calculate specific activity through a multi-stage approach, and by using different irradiation techniques. The results showed that the simulation technique designed in this study is in agreement with the experimental approach (with a difference of approximately 3%). It was also found that the maximum 177 Lu production at the maximum flux and irradiation time allows access to 723.5mCi/g after 27 cycles. Furthermore, the comparison of irradiation techniques showed that increasing the irradiation time is more effective in 177 Lu production efficiency than increasing the number of irradiation cycles. In a way that increasing the irradiation time would postpone the saturation of the productions. On the other hand, it was shown that the choice of an appropriate irradiation technique for 177 Lu production can be economically important in term of the effective fuel consumption in the reactor. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of electron-phonon coupling on the superconducting transition temperature in dodecaboride superconductors: A comparison of LuB12 with ZrB12

NASA Astrophysics Data System (ADS)

Teyssier, J.; Lortz, R.; Petrovic, A.; van der Marel, D.; Filippov, V.; Shitsevalova, N.

2008-10-01

We report a detailed study of specific heat, electrical resistivity, and optical spectroscopy in the superconducting boride LuB12 (Tc=0.4K) , and compare it to the higher Tc compound ZrB12 (Tc=6K) . Both compounds have the same structure based on enclosed metallic Lu or Zr ions in oversized boron cages. The infrared reflectivity and ellipsometry in the visible range allow us to extract the optical conductivity from 6 meV to 4 eV in the normal state from 20 to 280 K. By extracting the superconducting properties, phonon density of states, and electron-phonon coupling function from these measurements, we discuss the important factors governing Tc and explain the difference between the two compounds. The phonon density of states seems to be insignificantly modified by substitution of Zr with Lu. However, the soft vibrations of the metal ions in boron cages, responsible for the relatively high Tc in ZrB12 , have almost no contribution to the electron-phonon coupling in LuB12 .

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

NASA Astrophysics Data System (ADS)

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

2013-10-01

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

68Ga/177Lu-NeoBOMB1, a Novel Radiolabeled GRPR Antagonist for Theranostic Use in Oncology.

PubMed

Dalm, Simone U; Bakker, Ingrid L; de Blois, Erik; Doeswijk, Gabriela N; Konijnenberg, Mark W; Orlandi, Francesca; Barbato, Donato; Tedesco, Mattia; Maina, Theodosia; Nock, Berthold A; de Jong, Marion

2017-02-01

Because overexpression of the gastrin-releasing peptide receptor (GRPR) has been reported on various cancer types, for example, prostate cancer and breast cancer, targeting this receptor with radioligands might have a significant impact on staging and treatment of GRPR-expressing tumors. NeoBOMB1 is a novel DOTA-coupled GRPR antagonist with high affinity for GRPR and excellent in vivo stability. The purpose of this preclinical study was to further explore the use of NeoBOMB1 for theranostic application by determining the biodistribution of 68 Ga-NeoBOMB1 and 177 Lu-NeoBOMB1. PC-3 tumor-xenografted BALB/c nu/nu mice were injected with either approximately 13 MBq/250 pmol 68 Ga-NeoBOMB1 or a low (∼1 MBq/200 pmol) versus high (∼1 MBq/10 pmol) peptide amount of 177 Lu-NeoBOMB1, after which biodistribution and imaging studies were performed. At 6 time points (15, 30, 60, 120, 240, and 360 min for 68 Ga-NeoBOMB1 and 1, 4, 24, 48, 96, and 168 h for 177 Lu-NeoBOMB1) postinjection tumor and organ uptake was determined. To assess receptor specificity, additional groups of animals were coinjected with an excess of unlabeled NeoBOMB1. Results of the biodistribution studies were used to determine pharmacokinetics and dosimetry. Furthermore, PET/CT and SPECT/MRI were performed. Injection of approximately 250 pmol 68 Ga-NeoBOMB1 resulted in a tumor and pancreas uptake of 12.4 ± 2.3 and 22.7 ± 3.3 percentage injected dose per gram (%ID/g) of tissue, respectively, at 120 min after injection. 177 Lu-NeoBOMB1 biodistribution studies revealed a higher tumor uptake (17.9 ± 3.3 vs. 11.6 ± 1.3 %ID/g of tissue at 240 min after injection) and a lower pancreatic uptake (19.8 ± 6.9 vs. 105 ± 13 %ID/g of tissue at 240 min after injection) with the higher peptide amount injected, leading to a significant increase in the absorbed dose to the tumor versus the pancreas (200 pmol, 570 vs. 265 mGy/MBq; 10 pmol, 435 vs. 1393 mGy/MBq). Using these data to predict patient dosimetry, we found

PET attenuation correction for rigid MR Tx/Rx coils from 176Lu background activity

NASA Astrophysics Data System (ADS)

Lerche, Christoph W.; Kaltsas, Theodoris; Caldeira, Liliana; Scheins, Jürgen; Rota Kops, Elena; Tellmann, Lutz; Pietrzyk, Uwe; Herzog, Hans; Shah, N. Jon

2018-02-01

One challenge for PET-MR hybrid imaging is the correction for attenuation of the 511 keV annihilation radiation by the required RF transmit and/or RF receive coils. Although there are strategies for building PET transparent Tx/Rx coils, such optimised coils still cause significant attenuation of the annihilation radiation leading to artefacts and biases in the reconstructed activity concentrations. We present a straightforward method to measure the attenuation of Tx/Rx coils in simultaneous MR-PET imaging based on the natural 176Lu background contained in the scintillator of the PET detector without the requirement of an external CT scanner or PET scanner with transmission source. The method was evaluated on a prototype 3T MR-BrainPET produced by Siemens Healthcare GmbH, both with phantom studies and with true emission images from patient/volunteer examinations. Furthermore, the count rate stability of the PET scanner and the x-ray properties of the Tx/Rx head coil were investigated. Even without energy extrapolation from the two dominant γ energies of 176Lu to 511 keV, the presented method for attenuation correction, based on the measurement of 176Lu background attenuation, shows slightly better performance than the coil attenuation correction currently used. The coil attenuation correction currently used is based on an external transmission scan with rotating 68Ge sources acquired on a Siemens ECAT HR  +  PET scanner. However, the main advantage of the presented approach is its straightforwardness and ready availability without the need for additional accessories.

Lattice stabilities, mechanical and thermodynamic properties of Al3Tm and Al3Lu intermetallics under high pressure from first-principles calculations

NASA Astrophysics Data System (ADS)

Xu-Dong, Zhang; Wei, Jiang

2016-02-01

The effects of high pressure on lattice stability, mechanical and thermodynamic properties of L12 structure Al3Tm and Al3Lu are studied by first-principles calculations within the VASP code. The phonon dispersion curves and density of phonon states are calculated by using the PHONONPY code. Our results agree well with the available experimental and theoretical values. The vibrational properties indicate that Al3Tm and Al3Lu keep their dynamical stabilities in L12 structure up to 100 GPa. The elastic properties and Debye temperatures for Al3Tm and Al3Lu increase with the increase of pressure. The mechanical anisotropic properties are discussed by using anisotropic indices AG, AU, AZ, and the three-dimensional (3D) curved surface of Young’s modulus. The calculated results show that Al3Tm and Al3Lu are both isotropic at 0 GPa and anisotropic under high pressure. In the present work, the sound velocities in different directions for Al3Tm and Al3Lu are also predicted under high pressure. We also calculate the thermodynamic properties and provide the relationships between thermal parameters and temperature/pressure. These results can provide theoretical support for further experimental work and industrial applications. Project supported by the Scientific Technology Plan of the Educational Department of Liaoning Province and Liaoning Innovative Research Team in University, China (Grant No. LT2014004) and the Program for the Young Teacher Cultivation Fund of Shenyang University of Technology, China (Grant No. 005612).

Optical Temperature Sensor Based on Infrared Excited Green Upconversion Emission in Hexagonal Phase NaLuF4:Yb3+/Er3+ Nanorods.

PubMed

Li, Dongyu; Tian, Linlin; Huang, Zhen; Shao, Lexi; Quan, Jun; Wang, Yuxiao

2016-04-01

Hexagonal phase NaLuF4:Yb3+/Er3+ nanorods were synthesized hydrothermally. An analysis of the intense green upconversion emissions at 525 nm and 550 nm in hexagonal phase NaLuF4:Yb3/+Er3+ nanorods under excitation power density of 4.2 W/cm2 available from a diode laser emitting at 976 nm, have been undertaken. Fluorescence intensity ratio (FIR) variation of temperature-sensitive green upconversion emissions at 525 nm and 550 nm in this material was recorded in the physiological range from 295 to 343 K. The maximum sensitivity derived from the FIR technique of the green upconversion emissions is approximately 0.0044 K-1. Experimental results implied that hexagonal phase NaLuF4:Yb3/+Er3+ nanorods was a potential candidate for optical temperature sensor.

Efficient high-resolution hard x-ray imaging with transparent Lu2O3:Eu scintillator thin films

NASA Astrophysics Data System (ADS)

Marton, Zsolt; Miller, Stuart R.; Brecher, Charles; Kenesei, Peter; Moore, Matthew D.; Woods, Russell; Almer, Jonathan D.; Miceli, Antonino; Nagarkar, Vivek V.

2015-09-01

We have developed microstructured Lu2O3:Eu scintillator films that provide spatial resolution on the order of micrometers for hard X-ray imaging. In addition to their outstanding resolution, Lu2O3:Eu films also exhibits both high absorption efficiency for 20 to 100 keV X-rays, and bright 610 nm emission whose intensity rivals that of the brightest known scintillators. At present, high spatial resolution of such a magnitude is achieved using ultra-thin scintillators measuring only about 1 to 5 μm in thickness, which limits absorption efficiency to ~3% for 12 keV X-rays and less than 0.1% for 20 to 100 keV X-rays; this results in excessive measurement time and exposure to the specimen. But the absorption efficiency of Lu2O3:Eu (99.9% @12 keV and 30% @ 70 keV) is much greater, significantly decreasing measurement time and radiation exposure. Our Lu2O3:Eu scintillator material, fabricated by our electron-beam physical vapor deposition (EB-PVD) process, combines superior density of 9.5 g/cm3, a microcolumnar structure for higher spatial resolution, and a bright emission (48000 photons/MeV) whose wavelength is an ideal match for the underlying CCD detector array. We grew thin films of this material on a variety of matching substrates, measuring some 5-10μm in thickness and covering areas up to 1 x 1 cm2, which can be a suitable basis for microtomography, digital radiography as well as CT and hard X-ray Micro-Tomography (XMT). The microstructure and optical transparency of such screens was optimized, and their imaging performance was evaluated in the Argonne National Laboratory's Advanced Photon Source. Spatial resolution and efficiency were also characterized.

Synthesis of Multicolor Core/Shell NaLuF4:Yb3+/Ln3+@CaF2 Upconversion Nanocrystals

PubMed Central

Li, Hui; Hao, Shuwei; Yang, Chunhui; Chen, Guanying

2017-01-01

The ability to synthesize high-quality hierarchical core/shell nanocrystals from an efficient host lattice is important to realize efficacious photon upconversion for applications ranging from bioimaging to solar cells. Here, we describe a strategy to fabricate multicolor core @ shell α-NaLuF4:Yb3+/Ln3+@CaF2 (Ln = Er, Ho, Tm) upconversion nanocrystals (UCNCs) based on the newly established host lattice of sodium lutetium fluoride (NaLuF4). We exploited the liquid-solid-solution method to synthesize the NaLuF4 core of pure cubic phase and the thermal decomposition approach to expitaxially grow the calcium fluoride (CaF2) shell onto the core UCNCs, yielding cubic core/shell nanocrystals with a size of 15.6 ± 1.2 nm (the core ~9 ± 0.9 nm, the shell ~3.3 ± 0.3 nm). We showed that those core/shell UCNCs could emit activator-defined multicolor emissions up to about 772 times more efficient than the core nanocrystals due to effective suppression of surface-related quenching effects. Our results provide a new paradigm on heterogeneous core/shell structure for enhanced multicolor upconversion photoluminescence from colloidal nanocrystals. PMID:28336867

Agro-pastoral expansion and land use/land cover (LU/LC) change dynamics in Central-western Brazil

NASA Astrophysics Data System (ADS)

Sanga-Ngoie, K.; Yoshikawa, S.; Kanae, S.

2011-12-01

In Brazil, large-scale land cover changes following extensive deforestations are expected to generate big impacts onto the climate and the environment over this area, with eventually many negative feedbacks on the global scale. Mato Grosso State, located in the central western Brazil, is known to be the Brazilian state with the highest deforestation rate. Land use/land cover (LU/LC) changes have been reported to occur over large areas in this state due to the introduction of large-scale mechanized agriculture, extensive cattle ranching and uncontrolled slash-and-burn cultivation since the 1980s. In this study, we specifically aim at doing more detailed analysis for the causes of deforestation and savannization in this area, with special attention to agriculture and cattle ranching industry at the municipal district level in this state. Using GIS techniques and remotely-sensed NOAA/AVHRR data, we created 5-year Digital Vegetation Model Maps characterizing LU/LC features for every five years during the 1981-2001 periods using the PCA first components of the NOAA/AVHRR multi-spectral data. Our results make it clear that: (1) LU/LC changes among the phases are of the following 3 major types: degradation, recovery or transition; (2) The changes in LU/LC features are concomitant with the advance of cattle ranching and corn production activities toward the northern parts of the state, and with the expansion of soybean production in the central and western Mato Grosso; (3) Most of the agro-pastoral business are found in the southern Mato Grosso where about 46% of the state's deforestation during the 1981-2001 period occurred; (4) Rates of vegetation change are larger over non-inhabited areas (56%), especially in the north, than over the populated zones in the south (42%). Moreover, this work sheds some new light on the patterns of the changes in LU/LC features (deforestation and savannization) for each municipal district of Mato Grosso. In general, the following activities

Heavy ion irradiation-induced microstructural evolution in pyrochlore Lu{sub 2}Ti{sub 2}O{sub 7} at room temperature and 723 K

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

Xie, Q.R.; Zhang, J., E-mail: zhangjian@xmu.edu.cn; Dong, X.N.

Polycrystalline pyrochlore Lu{sub 2}Ti{sub 2}O{sub 7} pellets were irradiated with 600 keV Kr{sup 3+} at room temperature and 723 K to a fluence of 4×10{sup 15} ions/cm{sup 2}, corresponding to an average ballistic damage dose of 10 displacements per atom in the peak damage region. Irradiation-induced microstructural evolution was examined by grazing incidence X-ray diffraction, and cross-sectional transmission electron microscopy. Incomplete amorphization was observed in the sample irradiated at room temperature due to the formation of nano-crystal which has the identical structure of pyrochlore, and the formation of nano-crystal is attributed to the mechanism of epitaxial recrystallization. However, an orderedmore » pyrochlore phase to a swelling disordered fluorite phase transformation is occurred for the Lu{sub 2}Ti{sub 2}O{sub 7} sample irradiated at 723 K, which is due to the disordering of metal cations and anion vacancies. - Graphical Abstract: Polycrystalline pyrochlore Lu{sub 2}Ti{sub 2}O{sub 7} pellets were irradiated with 600 keV Kr{sup 3+} to a fluence of 4×10{sup 15} ions/cm{sup 2} at room temperature and 723 K, Incomplete amorphization was observed in the sample irradiated at room temperature due to the formation of nano-crystal. However, an ordered pyrochlore phase to a swelling disordered fluorite phase transformation is occurred for the Lu{sub 2}Ti{sub 2}O{sub 7} sample irradiated at 723 K, which is due to the disordering of metal cations and anion vacancies. - Highlights: Pyrochlore Lu{sub 2}Ti{sub 2}O{sub 7} pellets were irradiated by heavy ions at RT and 723 K. At RT irradiation, ~75% of amorphization was achieved. The nano-crystals were formed in the damage layer at RT irradiation. The formed nano-crystals enhanced the radiation tolerance of Lu{sub 2}Ti{sub 2}O{sub 7}. A pyrochlore to fluorite phase transformation was observed at 723 K irradiation.« less

German Multicenter Study Investigating 177Lu-PSMA-617 Radioligand Therapy in Advanced Prostate Cancer Patients.

PubMed

Rahbar, Kambiz; Ahmadzadehfar, Hojjat; Kratochwil, Clemens; Haberkorn, Uwe; Schäfers, Michael; Essler, Markus; Baum, Richard P; Kulkarni, Harshad R; Schmidt, Matthias; Drzezga, Alexander; Bartenstein, Peter; Pfestroff, Andreas; Luster, Markus; Lützen, Ulf; Marx, Marlies; Prasad, Vikas; Brenner, Winfried; Heinzel, Alexander; Mottaghy, Felix M; Ruf, Juri; Meyer, Philipp Tobias; Heuschkel, Martin; Eveslage, Maria; Bögemann, Martin; Fendler, Wolfgang Peter; Krause, Bernd Joachim

2017-01-01

177 Lu-labeled PSMA-617 is a promising new therapeutic agent for radioligand therapy (RLT) of patients with metastatic castration-resistant prostate cancer (mCRPC). Initiated by the German Society of Nuclear Medicine, a retrospective multicenter data analysis was started in 2015 to evaluate efficacy and safety of 177 Lu-PSMA-617 in a large cohort of patients. One hundred forty-five patients (median age, 73 y; range, 43-88 y) with mCRPC were treated with 177 Lu-PSMA-617 in 12 therapy centers between February 2014 and July 2015 with 1-4 therapy cycles and an activity range of 2-8 GBq per cycle. Toxicity was categorized by the common toxicity criteria for adverse events (version 4.0) on the basis of serial blood tests and the attending physician's report. The primary endpoint for efficacy was biochemical response as defined by a prostate-specific antigen decline ≥ 50% from baseline to at least 2 wk after the start of RLT. A total of 248 therapy cycles were performed in 145 patients. Data for biochemical response in 99 patients as well as data for physician-reported and laboratory-based toxicity in 145 and 121 patients, respectively, were available. The median follow-up was 16 wk (range, 2-30 wk). Nineteen patients died during the observation period. Grade 3-4 hematotoxicity occurred in 18 patients: 10%, 4%, and 3% of the patients experienced anemia, thrombocytopenia, and leukopenia, respectively. Xerostomia occurred in 8%. The overall biochemical response rate was 45% after all therapy cycles, whereas 40% of patients already responded after a single cycle. Elevated alkaline phosphatase and the presence of visceral metastases were negative predictors and the total number of therapy cycles positive predictors of biochemical response. The present retrospective multicenter study of 177 Lu-PSMA-617 RLT demonstrates favorable safety and high efficacy exceeding those of other third-line systemic therapies in mCRPC patients. Future phase II/III studies are warranted to

Comparison of sequential planar 177Lu-DOTA-TATE dosimetry scans with 68Ga-DOTA-TATE PET/CT images in patients with metastasized neuroendocrine tumours undergoing peptide receptor radionuclide therapy.

PubMed

Sainz-Esteban, Aurora; Prasad, Vikas; Schuchardt, Christiane; Zachert, Carolin; Carril, José Manuel; Baum, Richard P

2012-03-01

The aim of the study was to compare sequential (177)Lu-DOTA-TATE planar scans ((177)Lu-DOTA-TATE) in patients with metastasized neuroendocrine tumours (NET) acquired during peptide receptor radionuclide therapy (PRRT) for dosimetry purposes with the pre-therapeutic (68)Ga-DOTA-TATE positron emission tomography (PET)/CT ((68)Ga-DOTA-TATE) maximum intensity projection (MIP) images obtained in the same patients concerning the sensitivity of the different methods. A total of 44 patients (59 ± 11 years old) with biopsy-proven NET underwent (68)Ga-DOTA-TATE and (177)Lu-DOTA-TATE imaging within 7.9 ± 7.5 days between the two examinations. (177)Lu-DOTA-TATE planar images were acquired at 0.5, 2, 24, 48 and 72 h post-injection; lesions were given a score from 0 to 4 depending on the uptake of the radiopharmaceutical (0 being lowest and 4 highest). The number of tumour lesions which were identified on (177)Lu-DOTA-TATE scans (in relation to the acquisition time after injection of the therapeutic dose as well as with regard to the body region) was compared to those detected on (68)Ga-DOTA-TATE studies obtained before PRRT. A total of 318 lesions were detected; 280 (88%) lesions were concordant. Among the discordant lesions, 29 were (68)Ga-DOTA-TATE positive and (177)Lu-DOTA-TATE negative, whereas 9 were (68)Ga-DOTA-TATE negative and (177)Lu-DOTA-TATE positive. The sensitivity, positive predictive value and accuracy for (177)Lu-DOTA-TATE as compared to (68)Ga-DOTA-TATE were 91, 97 and 88%, respectively. Significantly more lesions were seen on the delayed (72 h) (177)Lu-DOTA-TATE images (91%) as compared to the immediate (30 min) images (68%). The highest concordance was observed for bone metastases (97%) and the lowest for head/neck lesions (75%). Concordant lesions (n = 77; mean size 3.8 cm) were significantly larger than discordant lesions (n = 38; mean size 1.6 cm) (p < 0.05). No such significance was found for differences in maximum standardized uptake value (SUV

Isomeric ratio measurements for the radiative neutron capture 176Lu(n ,γ ) at the LANL DANCE facility

NASA Astrophysics Data System (ADS)

Denis-Petit, D.; Roig, O.; Méot, V.; Morillon, B.; Romain, P.; Jandel, M.; Kawano, T.; Vieira, D. J.; Bond, E. M.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Keksis, A. L.; Rundberg, R. S.; Ullmann, J. L.

2016-11-01

The isomeric ratios for the neutron capture reaction 176Lu(n ,γ ) to the Jπ=5 /2- , 761.7 keV, T1 /2=32.8 ns and the Jπ=15 /2+ , 1356.9 keV, T1 /2=11.1 ns levels of 177Lu have been measured for the first time. The experiment was carried out with the Detector for Advanced Neutron Capture Experiments (DANCE) at the Los Alamos National Laboratory. Measured isomeric ratios are compared with talys calculations using different models for photon strength functions, level densities, and optical potentials. In order to reproduce the experimental γ -ray spectra, a low-energy resonance must be added in the photon strength function used in our Hauser-Feshbach calculations.

Family history in breast cancer in São Luís, Maranhão, Brazil.

PubMed

Ribeiro, Maria Hilda Araújo; da Silva, Marcos Antonio Custódio Neto; Muniz Filho, Walbert Edson; Nascimento, Anna Cyntia Brandão; Souza, Rodrigo Duart Martins; Machado, Carlos Eduardo Everton; Silva, Dulcelena Ferreira; de Barros Bezerra, Geusa Felipa; de Castro Viana, Graça Maria; Soares Brandão Nascimento, Maria do Desterro

2016-03-10

Familial cancer includes some types of cancer aggregation without a well-defined inheritance pattern. Cancer genetics is an essential component of clinical practice in oncology. In Brazil, breast cancer is the leading cause of death in women. In Maranhão, studies on genetic predisposition are necessary to investigate the incidence and mortality rates. The aim of this study was to investigate familial cancer among relatives of women who died of breast cancer in São Luís, Brazil, constructing a pedigree to identify families with a hereditary predisposition, an important step in the early diagnosis of malignant tumors. The city of São Luís is located on the Island of Maranhão, northeastern Brazil, with a population of 997,098 inhabitants mainly comprising blacks and mulattoes, including descendants of runaway slaves from the Amazon region itself. Data for pedigree construction were obtained from the records of 54 patients seen at the Aldenora Bello Institute of Oncology, São Luís, between 2000 and 2007, as well as by interview with relatives of the patients. The mean patient age at diagnosis was 39.5 years. Most women were mulattoes (36/54, 66.6%). A history of cancer was observed in 18 families, with 16 families possessing cases of cancer among first-degree relatives and five among second-degree relatives. A concentration of cancer cases was found in families of patients diagnosed until the age of 40, a finding demonstrating the importance of a family history prior to genetic counseling.

Facile synthesis and color-tunable properties of BaLuF5:Ce,Tb,Eu(Sm) submicrospheres via a facile ionic liquid/EG two-phase system.

PubMed

Song, Yanhua; Li, Yi; Zhao, Tianqi; Wang, Yuexin; Cui, Tingting; Sheng, Ye; Zheng, Keyan; Zhou, Xiuqing; You, Hongpeng; Zou, Haifeng

2017-02-01

BaLuF 5 :Ce,Tb,Eu(Sm) submicrospheres were synthesized via an ILs/ethylene glycol(EG) two-phase system. The crystalline phase, size, morphology, and luminescence properties were characterized using powder X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectra. The results show that 1-methyl-3-octylimidazolium hexafluorophosphate ([Omim]PF 6 ) was used as fluoride source and capping agent to tune morphology and size of the crystals. The formation mechanism has been supposed. Under the excitation of ultraviolet, the BaLuF 5 :5%Ce 3+ ,5%Tb 3+ , BaLuF 5 :Eu 3+ , and BaLuF 5 :5%Ce 3+ ,5%Sm 3+ exhibit green and red emission, which was derived from Tb 3+ , Eu 3+ , and Sm 3+ emission. When codoping Ce 3+ , Tb 3+ , Sm 3+ or Eu 3+ together, multi-color emission can be realized. Furthermore, this synthetic route may have potential applications for fabricating other lanthanide fluorides. Copyright © 2016 Elsevier Inc. All rights reserved.

(177)Lu: DDEP Evaluation of the decay scheme for an emerging radiopharmaceutical.

PubMed

Kellett, M A

2016-03-01

A new decay scheme evaluation using the DDEP methodology for (177)Lu is presented. Recently measured half-life measurements have been incorporated, as well as newly available γ-ray emission probabilities. For the first time, a thorough investigation has been made of the γ-ray multipolarities. The complete data tables and detailed evaluator comments are available through the DDEP website. Copyright © 2015 Elsevier Ltd. All rights reserved.

Neutron capture measurement on {sup 173}Lu at LANSCE with DANCE detector

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

Theroine, C.; Ebran, A.; Meot, V.

2013-06-10

The (n,{gamma}) cross section on the unstable {sup 173}Lu(t{sub 1/2} = 1.37y) has been measured from thermal energy up to 200 eV at Los Alamos Neutron Science Center (LANSCE) with The Detector for Advanced Neutron Capture Experiements (DANCE). The main aim of this study is to validate and optimize reaction models for unstable nucleus. A preliminary capture yield will be presented in this paper.

A Flexible CUDA LU-based Solver for Small, Batched Linear Systems

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

Tumeo, Antonino; Gawande, Nitin A.; Villa, Oreste

This chapter presents the implementation of a batched CUDA solver based on LU factorization for small linear systems. This solver may be used in applications such as reactive flow transport models, which apply the Newton-Raphson technique to linearize and iteratively solve the sets of non linear equations that represent the reactions for ten of thousands to millions of physical locations. The implementation exploits somewhat counterintuitive GPGPU programming techniques: it assigns the solution of a matrix (representing a system) to a single CUDA thread, does not exploit shared memory and employs dynamic memory allocation on the GPUs. These techniques enable ourmore » implementation to simultaneously solve sets of systems with over 100 equations and to employ LU decomposition with complete pivoting, providing the higher numerical accuracy required by certain applications. Other currently available solutions for batched linear solvers are limited by size and only support partial pivoting, although they may result faster in certain conditions. We discuss the code of our implementation and present a comparison with the other implementations, discussing the various tradeoffs in terms of performance and flexibility. This work will enable developers that need batched linear solvers to choose whichever implementation is more appropriate to the features and the requirements of their applications, and even to implement dynamic switching approaches that can choose the best implementation depending on the input data.« less

Growth and luminescent properties of scintillators based on the single crystalline films of Lu{sub 3−x}Gd{sub x}Al{sub 5}O{sub 12}:Ce garnet

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

Zorenko, Yu, E-mail: zorenko@ukw.edu.pl; Laboratory for Optoelectronic Materials, Department of Electronics of Ivan Franko National University of Lviv, 79017 Lviv; Gorbenko, V.

Highlights: • Single crystalline films of Lu{sub 3−x}Gd{sub x}Al{sub 5}O{sub 12} garnets at x = 0 ÷ 3.0 were grown by LPE method onto YAG substrates. • Lattice constant of Lu{sub 3−}Gd{sub x}Al{sub 5}O{sub 12}:Ce film and the misfit m between films and YAG substrate changed linearly with increasing of Gd content. • Effective Gd{sup 3+}–Ce{sup 3+} energy transfer occurs in the Lu{sub 3−x}Gd{sub x}Al{sub 5}O{sub 12}:Ce films. • Best scintillation light yield is observed in the Lu{sub 3}Al{sub 5}O{sub 12}:Ce and Lu{sub 2.4}Gd{sub 0.6}Al{sub 5}O{sub 12}:Ce films. • Increase of the Gd content in x = 1.5–2.5 range resultsmore » in decreasing the scintillation LY of Lu{sub 3−x}Gd{sub x}Al{sub 5}O{sub 12}:Ce films. - Abstract: The work is related to the growth of scintillators based on the single crystalline films (SCF) of Ce{sup 3+} doped Lu{sub 3−}Gd{sub x}Al{sub 5}O{sub 12} mixed rare-earth garnets by Liquid Phase Epitaxy (LPE) method. We have shown, that full set of Lu{sub 3−}Gd{sub x}Al{sub 5}O{sub 12} SCFs with x values ranging from 0 to 3.0 can be successfully crystallized by the LPE method onto Y{sub 3}Al{sub 5}O{sub 12} (YAG) substrates from the melt-solutions based on PbO-B{sub 2}O{sub 3} flux. The absorption, X-ray excited luminescence, photoluminescence, thermoluminescence and light yield measurements, the latter under excitation by α-particles of {sup 239}Pu and {sup 241}Am radioisotopes, were applied for their characterization.« less

Fate of Lu(III) sorbed on 2-line ferrihydrite at pH 5.7 and aged for 12 years at room temperature. II: insights from STEM-EDXS and DFT calculations.

PubMed

Yokosawa, Tadahiro; Prestat, Eric; Polly, Robert; Bouby, Muriel; Dardenne, Kathy; Finck, Nicolas; Haigh, Sarah J; Denecke, Melissa A; Geckeis, Horst

2018-04-18

Transformation products of two-line ferrihydrite associated with Lu(III) were studied after 12 years of aging using aberration-corrected high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), high-efficiency energy-dispersive X-ray spectroscopy (EDXS), and density functional theory (DFT). The transformation products consisted of hematite nanoparticles with overgrown goethite needles. High-efficiency STEM-EDXS revealed that Lu is only associated with goethite needles, and atomic-resolution HAADF-STEM reveals structural incorporation of Lu within goethite, partially replacing structural Fe sites. This finding corroborates those recently obtained by AsFlFFF and EXAFS spectroscopy on the same sample (Finck et al. 2018). DFT calculations indicate that Lu incorporation within goethite or hematite are almost equally likely, suggesting that experimental parameters such as temperature and reaction time which affect reaction kinetics, play important roles in determining the Lu uptake. It seems likely that these results may be transferable to predict the behavior of chemically homologous trivalent actinides.

Structural, magnetic and magnetoreactance studies in NiFe2-xRxO4 (x = 0, 0.05; R = Y, Yb and Lu)

NASA Astrophysics Data System (ADS)

Ugendar, Kodam; Chunchu, Venkatrao; Rani, G. Neeraja; Markaneyulu, G.

2018-04-01

Structural, magnetic and magnetoreactance (mr) properties of NiFe2-xRxO4 (x = 0, 0.05; R = Y, Yb and Lu) compounds were investigated and the results are discussed and presented in this paper. Rietveld refined X-ray diffraction (XRD) patterns and Raman spectroscopy revealed the cubic inverse spinel phase for all the compounds investigated. The former also identified small amounts of RFeO3 as the secondary phase. Lattice constant values were increased upon partial substitution of Fe3+ by R3+ (R = Y, Yb and Lu). Magnetization measurements revealed that the magnetic moment of R3+ (R = Y, Yb and Lu) substituted compounds decreased compared with NiFe2O4. mr was measured at 3 kHz and 3 MHz both longitudinal (LT) and transverse (TR) configuration. A maximum mr of 54 % was observed in Y3+ substituted NiFe2O4 in TR mode.

Standardization of Procedures for the Preparation of (177)Lu- and (90)Y-labeled DOTA-Rituximab Based on the Freeze-dried Kit Formulation.

PubMed

Wojdowska, Wioletta; Karczmarczyk, Urszula; Maurin, Michal; Garnuszek, Piotr; Mikołajczak, Renata

2015-01-01

Rituximab when radiolabelled with (177)Lu or (90)Y has been investigated for the treatment of patients with Non-Hodgkin's Lymphoma. In this study, we optimized the preparation of antibody conjugates with chelating agent in the freeze-dried kit. It shortens procedures needed for the successful radiolabeling with lutetium-177 and yttrium-90 and assures reproducible labelling yields. Various molar ratios of Rituximab:DOTA (from 1:5 to 1:100) were used at the conjugation step and different purification method to remove unbound DOTA were investigated (size-exclusion chromatography, dialysis, ultrafiltration). The final monoclonal antibody concentration was quantified by Bradford method, and the number of DOTA molecules was determined by radiolabeling assay using (64)Cu. The specific activity of (177)Lu-DOTA-Rituximab and (90)Y-DOTA-Rituximab were optimized using various amounts of radiometal. Quality control (SE-HPLC, ITLC) and stability study were performed. An average of 4.2 ± 0.8 p-SCN-Bz-DOTA molecules could be randomly conjugated to a single molecule of Rituximab. The ultrafiltration system was the most efficient for purification and resulted in the highest recovery efficiency (77.2%). At optimized conditions the (177)Lu-DOTARituximab and (90)Y-DOTA-Rituximab were obtained with radiochemical purity >99% and specific activity ca. 600 MBq/mg. The radioimmunoconjugates were stable in human serum and 0.9% NaCl. After 72 h of incubation the radiochemical purity of (177)Lu-DOTA-Rituximab decreased to 94% but it was still more than 88% for (90)Y-DOTA-Rituximab. The radioimmunoconjugate showed stability after six months storage at 2 - 8(0)C, as a lyophilized formulation. Our study shows that Rituximab-DOTA can be efficiently radiolabeled with (177)Lu and (90)Y via p-SCN-Bn-DOTA using a freezedried kit.

Photoluminescence properties of phosphors based on Lu3+-stabilized Gd3Al5O12:Tb3+/Ce3+ garnet solid solutions

NASA Astrophysics Data System (ADS)

Li, Jinkai; Li, Ji-Guang; Li, Xiaodong; Sun, Xudong

2016-12-01

The Gd3Al5O12:Tb/Ce (GdAG:Tb/Ce) garnet solutions effectively stabilized by Lu3+ have been achieved by calcining their precursor at 1300 °C. Detailed characterizations are given to the materials in terms of XRD, FE-SEM, BET, PL/PLE, and fluorescence decay analysis. The occurrence of Gd3+ and Tb3+ transitions from the photoluminescence excitation spectrum monitoring the Ce3+ yellow emission strongly confirmed the efficient Gd3+ → Ce3+ and Tb3+ → Ce3+ energy transfer. The [(Gd0.8Lu0.2)0.99-xCe0.01Tbx]AG (x = 0-0.1) phosphors with good dispersion and uniform particle size exhibit various luminescent properties under different excitation wavelength of 275, 338, and 457 nm, respectively. The photoluminescence comparison indicated that owing to the Gd3+ → Ce3+ and Tb3+ → Ce3+ energy transfer, the best luminescent phosphor [(Gd0.8Lu0.2)0.89Ce0.01 Tb0.1]AG is almost identical to the well-known YAG:Ce, higher than LuAG:Ce in emission intensity, and has a substantially red-shifted emission band that is desired for warm-white lighting. The Tb3+ → Ce3+ energy transfer was suggested to be electric multipolar interactions, and the processes of energy migration among the optically active Gd3+, Tb3+, and Ce3+ ions were discussed in detail. Fluorescence decay analysis found the lifetime for the Ce3+ emission hardly changes with the Tb3+ incorporation. The [(Gd0.8Lu0.2)0.99-xCe0.01Tbx]AG garnets developed in this work may serve as a new type of phosphor that hopefully meets the requirements of various lighting, optical display, and scintillation applications.

Lu-Hf and Sm-Nd isotope systematics of Korean spinel peridotites: A case for metasomatically induced Nd-Hf decoupling

NASA Astrophysics Data System (ADS)

Choi, Sung Hi; Mukasa, Samuel B.

2012-12-01

We determined the Lu-Hf and Sm-Nd isotope compositions of spinel peridotite xenoliths in alkali basalts from Baengnyeong and Jeju islands, South Korea, to constrain the timing of melt-depletion events and stabilization of the lithospheric mantle beneath the region. Equilibration temperatures estimated by two-pyroxene thermometry range from 780 to 950 °C, and from 960 to 1010 °C for Baengnyeong and Jeju peridotites, respectively. The Baengnyeong peridotite clinopyroxenes are characterized by extremely radiogenic Hf in association with isotopically less extreme Nd, resulting in strong Nd-Hf decoupling referenced to the mantle array. This is in stark contrast to the well-correlated isotopic compositions of Hf and Nd in the Jeju peridotite clinopyroxenes, which plot along the Nd-Hf mantle array. The Hf abundances and isotopic compositions of the Baengnyeong clinopyroxenes were less affected by relatively recent secondary enrichments that overprinted the light rare earth element abundances and Nd isotopes, causing the decoupling of the Nd-Hf isotopes. The Nd-Hf isotopic compositions of the Jeju peridotites appear to have been re-equilibrated, probably as a result of efficient diffusion at the relatively higher temperatures of the Jeju peridotites. Lu-Hf tie lines for clinopyroxene and orthopyroxene from four of the Korean peridotites have negative slopes on a Lu-Hf isochron diagram, yielding negative ages. This is interpreted to indicate recent isotopic exchange in orthopyroxene by reaction with metasomatic agents having low 176Hf/177Hf components. Secondary overprinting in orthopyroxene was facilitated by the considerably lower Hf concentrations than in co-located clinopyroxene. Baengnyeong lherzolite clinopyroxenes yield a Lu-Hf errorchron age of 1.9 ± 0.1 Ga, which is independently supported by a model Os age (based on Re depletion or TRD) of 1.8 Ga on a refractory Baengnyeong peridotite. We interpret this age range to mark the time of stabilization of the mantle

Lu-Hf and Sm-Nd isotope systematics of Korean spinel peridotites: A case for metasomatically induced Nd-Hf decoupling

NASA Astrophysics Data System (ADS)

Choi, S.; Mukasa, S. B.

2012-12-01

We determined the Lu-Hf and Sm-Nd isotope compositions of spinel peridotite xenoliths in alkali basalts from Baengnyeong and Jeju islands, South Korea, to constrain the timing of melt-depletion events and stabilization of the lithospheric mantle beneath the region. Equilibration temperatures estimated by two-pyroxene thermometry range from 780 to 950°C, and from 960 to 1010°C for Baengnyeong and Jeju peridotites, respectively. The Baengnyeong peridotite clinopyroxenes are characterized by extremely radiogenic Hf in association with isotopically less extreme Nd, resulting in strong Nd-Hf decoupling referenced to the mantle array. This is in stark contrast to the well-correlated isotopic compositions of Hf and Nd in the Jeju peridotite clinopyroxenes, which plot along the Nd-Hf mantle array. The Hf abundances and isotopic compositions of the Baengnyeong clinopyroxenes were less affected by relatively recent secondary enrichments that overprinted the light rare earth element abundances and Nd isotopes, causing the decoupling of the Nd-Hf isotopes. The Nd-Hf isotopic compositions of the Jeju peridotites appear to have been re-equilibrated, probably as a result of efficient diffusion at the relatively higher temperatures of the Jeju peridotites. Lu-Hf tie lines for clinopyroxene and orthopyroxene from four of the Korean peridotites have negative slopes on a Lu-Hf isochron diagram, yielding negative ages. This is interpreted to indicate recent isotopic exchange in orthopyroxene by reaction with metasomatic agents having low 176Hf/177Hf components. Secondary overprinting in orthopyroxene was facilitated by the considerably lower Hf concentrations than in co-located clinopyroxene. Baengnyeong lherzolite clinopyroxenes yield a Lu-Hf errorchron age of 1.9 ± 0.1 Ga, which is independently supported by a model Os age (based on Re depletion or TRD) of 1.8 Ga on a refractory Baengnyeong peridotite. We interpret this age range to mark the time of stabilization of the mantle

LuAG:Pr3+-porphyrin based nanohybrid system for singlet oxygen production: Toward the next generation of PDTX drugs.

PubMed

Popovich, Kseniya; Tomanová, Kateřina; Čuba, Václav; Procházková, Lenka; Pelikánová, Iveta Terezie; Jakubec, Ivo; Mihóková, Eva; Nikl, Martin

2018-02-01

A highly prospective drug for the X-ray induced photodynamic therapy (PDTX), LuAG:Pr 3+ @SiO 2 -PpIX nanocomposite, was successfully prepared by a three step process: photo-induced precipitation of the Lu 3 Al 5 O 12 :Pr 3+ (LuAG:Pr 3+ ) core, sol-gel technique for amorphous silica coating, and a biofunctionalization by attaching the protoporphyrin IX (PpIX) molecules. The synthesis procedure provides three-layer nanocomposite with uniform shells covering an intensely luminescent core. Room temperature radioluminescence (RT RL) spectra as well as photoluminescence (RT PL) steady-state and time resolved spectra of the material confirm the non-radiative energy transfer from the core Pr 3+ ions to the PpIX outer layer. First, excitation of Pr 3+ ions results in the red luminescence of PpIX. Second, the decay measurements exhibit clear evidence of mentioned non-radiative energy transfer (ET). The singlet oxygen generation in the system was demonstrated by the 3'-(p-aminophenyl) fluorescein (APF) chemical probe sensitive to the singlet oxygen presence. The RT PL spectra of an X-ray irradiated material with the APF probe manifest the formation of singlet oxygen due to which enhanced luminescence around 530 nm is observed. Quenching studies, using NaN 3 as an 1 O 2 inhibitor, also confirm the presence of 1 O 2 in the system and rule out the parasitic reaction with OH radicals. To summarize, presented features of LuAG:Pr 3+ @SiO 2 -PpIX nanocomposite indicate its considerable potential for PDTX application. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluation of dead-time corrections for post-radionuclide-therapy (177)Lu quantitative imaging with low-energy high-resolution collimators.

PubMed

Celler, Anna; Piwowarska-Bilska, Hanna; Shcherbinin, Sergey; Uribe, Carlos; Mikolajczak, Renata; Birkenfeld, Bozena

2014-01-01

Dead-time (DT) effects rarely cause problems in diagnostic single-photon emission computed tomography (SPECT) studies; however, in post-radionuclide-therapy imaging, DT can be substantial. Therefore, corrections may be necessary if quantitative images are used in image-based dosimetry or for evaluation of therapy outcomes. This task is particularly challenging if low-energy collimators are used. Our goal was to design a simple method to determine the dead-time correction factor (DTCF) without the need for phantom experiments and complex calculations. Planar and SPECT/CT scans of a water phantom containing a 70 ml bottle filled with lutetium-177 (Lu) were acquired over 60 days. Two small Lu markers were used in all scans. The DTCF based on the ratio of observed to true count rates measured over the entire spectrum and using photopeak primary photons only was estimated for phantom (DT present) and marker (no DT) scans. In addition, variations in counts in SPECT projections (potentially caused by varying bremsstrahlung and scatter) were investigated. For count rates that were about two-fold higher than typically seen in post-therapy Lu scans, the maximum DTCF reached a level of about 17%. The DTCF values determined directly from the phantom experiments using the total energy spectrum and photopeak counts only were equal to 13 and 16%, respectively. They were closely matched by those from the proposed marker-based method, which uses only two energy windows and measures photopeak primary photons (15-17%). A simple, marker-based method allowing for determination of the DTCF in high-activity Lu imaging studies has been proposed and validated using phantom experiments.

Robust tunability of magnetoresistance in half-Heusler R PtBi ( R = Gd , Dy, Tm, and Lu) compounds

DOE PAGES

Mun, Eundeok; Bud'ko, Sergey L.; Canfield, Paul C.

2016-03-15

We present the magnetic field dependencies of transport properties for RPtBi ( R = Gd, Dy, Tm, and Lu) half-Heusler compounds. Temperature- and field-dependent resistivity measurements of high-quality RPtBi single crystals reveal an unusually large, nonsaturating magnetoresistance (MR) up to 300 K under a moderate magnetic field of H = 140 kOe. At 300 K, the large MR effect decreases as the rare earth is traversed from Gd to Lu and the magnetic field dependence of MR shows a deviation from the conventional H2 behavior. The Hall coefficient ( RH) for R = Gd indicates a sign change around 120more » K, whereas RH curves for R = Dy, Tm, and Lu remain positive for all measured temperatures. At 300 K, the Hall resistivity reveals a deviation from the linear field dependence for all compounds. Thermoelectric power measurements on this family show strong temperature and magnetic field dependencies which are consistent with resistivity measurements. A highly enhanced thermoelectric power under applied magnetic field is observed as high as ~100 μV/K at 140 kOe. Furthermore, analysis of the transport data in this series reveals that the rare-earth-based half-Heusler compounds provide opportunities to tune MR effect through lanthanide contraction and to elucidate the mechanism of nontrivial MR.« less

Effects of biaxial strain on the improper multiferroicity in h – LuFe O 3 films studied using the restrained thermal expansion method

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

Sinha, Kishan; Zhang, Yubo; Jiang, Xuanyuan

Elastic strain is potentially an important approach in tuning the properties of the improperly multiferroic hexagonal ferrites, the details of which have however been elusive due to the experimental difficulties. Employing the method of restrained thermal expansion, we have studied the effect of isothermal biaxial strain in the basal plane of h-LuFeO 3 (001) films. The results indicate that a compressive biaxial strain significantly enhances the K 3 structural distortion (the order parameter of the improper ferroelectricity), and the effect is larger at higher temperatures. The compressive biaxial strain and the enhanced K 3 structural distortion together, cause an increasemore » in the electric polarization and a reduction in the canting of the weak ferromagnetic moments in h-LuFeO 3, according to our first principle calculations. These findings are important for understanding the strain effect as well as the coupling between the lattice and the improper multiferroicity in h-LuFeO 3. Finally, the experimental elucidation of the strain effect in h-LuFeO 3 films also suggests that the restrained thermal expansion can be a viable method to unravel the strain effect in many other thin film materials.« less

Effects of biaxial strain on the improper multiferroicity in h – LuFe O 3 films studied using the restrained thermal expansion method

DOE PAGES

Sinha, Kishan; Zhang, Yubo; Jiang, Xuanyuan; ...

2017-03-14

Elastic strain is potentially an important approach in tuning the properties of the improperly multiferroic hexagonal ferrites, the details of which have however been elusive due to the experimental difficulties. Employing the method of restrained thermal expansion, we have studied the effect of isothermal biaxial strain in the basal plane of h-LuFeO 3 (001) films. The results indicate that a compressive biaxial strain significantly enhances the K 3 structural distortion (the order parameter of the improper ferroelectricity), and the effect is larger at higher temperatures. The compressive biaxial strain and the enhanced K 3 structural distortion together, cause an increasemore » in the electric polarization and a reduction in the canting of the weak ferromagnetic moments in h-LuFeO 3, according to our first principle calculations. These findings are important for understanding the strain effect as well as the coupling between the lattice and the improper multiferroicity in h-LuFeO 3. Finally, the experimental elucidation of the strain effect in h-LuFeO 3 films also suggests that the restrained thermal expansion can be a viable method to unravel the strain effect in many other thin film materials.« less

Efficient upconversion-pumped continuous wave Er3+:LiLuF4 lasers

NASA Astrophysics Data System (ADS)

Moglia, Francesca; Müller, Sebastian; Reichert, Fabian; Metz, Philip W.; Calmano, Thomas; Kränkel, Christian; Heumann, Ernst; Huber, Günter

2015-04-01

We report on detailed spectroscopic investigations and efficient visible upconversion laser operation of Er3+:LiLuF4. This material allows for efficient resonant excited-state-absorption (ESA) pumping at 974 nm. Under spectroscopic conditions without external feedback, ESA at the laser wavelength of 552 nm prevails stimulated emission. Under lasing conditions in a resonant cavity, the high intracavity photon density bleaches the ESA at 552 nm, allowing for efficient cw laser operation. We obtained the highest output power of any room-temperature crystalline upconversion laser. The laser achieves a cw output power of 774 mW at a slope efficiency of 19% with respect to the incident pump power delivered by an optically-pumped semiconductor laser. The absorption efficiency of the pump radiation is estimated to be below 50%. To exploit the high confinement in waveguides for this laser, we employed femtosecond-laser pulses to inscribe a cladding of parallel tracks of modified material into Er3+:LiLuF4 crystals. The core material allows for low-loss waveguiding at pump and laser wavelengths. Under Ti:sapphire pumping at 974 nm, the first crystalline upconversion waveguide laser has been realized. We obtained waveguide-laser operation with up to 10 mW of output power at 553 nm.

Laser performance of in-band pumped Er : LiYF{sub 4} and Er : LiLuF{sub 4} crystals

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

Gorbachenya, K N; Kisel, V E; Yasukevich, A S

2016-02-28

Spectroscopic properties of Er : LiLuF{sub 4} and Er : LiYF{sub 4} crystals in the spectral region near 1.5 μm and the lasing characteristics of these crystals under in-band pumping at a wavelength of 1522 nm are studied. With the Er : LiLuF{sub 4} crystal, the maximum slope efficiency with respect to the absorbed pump power was 44% at a wavelength of 1609 nm. Continuous-wave operation of an inband pumped Er : LiYF{sub 4} laser is obtained for the first time. The output power at a wavelength of 1606 nm was 58 mW with a slope efficiency of 21%. (lasers)

Targeted radionuclide therapy with RAFT-RGD radiolabelled with (90)Y or (177)Lu in a mouse model of αvβ3-expressing tumours.

PubMed

Bozon-Petitprin, A; Bacot, S; Gauchez, A S; Ahmadi, M; Bourre, J C; Marti-Batlle, D; Perret, P; Broisat, A; Riou, L M; Claron, M; Boturyn, D; Fagret, D; Ghezzi, Catherine; Vuillez, J P

2015-02-01

The αvβ3 integrin plays an important role in tumour-induced angiogenesis, tumour proliferation, survival and metastasis. The tetrameric RGD-based peptide, regioselectively addressable functionalized template-(cyclo-[RGDfK])4 (RAFT-RGD), specifically targets the αvβ3 integrin in vitro and in vivo. The aim of this study was to evaluate the therapeutic potential of RAFT-RGD radiolabelled with β(-) emitters in a nude mouse model of αvβ3 integrin-expressing tumours. Biodistribution and SPECT/CT imaging studies were performed after injection of (90)Y-RAFT-RGD or (177)Lu-RAFT-RGD in nude mice subcutaneously xenografted with αvβ3 integrin-expressing U-87 MG cells. Experimental targeted radionuclide therapy with (90)Y-RAFT-RGD or (177)Lu-RAFT-RGD and (90)Y-RAFT-RAD or (177)Lu-RAFT-RAD (nonspecific controls) was evaluated by intravenous injection of the radionuclides into mice bearing αvβ3 integrin-expressing U-87 MG tumours of different sizes (small or large) or bearing TS/A-pc tumours that do not express αvβ3. Tumour volume doubling time was used to evaluate the efficacy of each treatment. Injection of 37 MBq of (90)Y-RAFT-RGD into mice with large αvβ3-positive tumours or 37 MBq of (177)Lu-RAFT-RGD into mice with small αvβ3-positive tumours caused significant growth delays compared to mice treated with 37 MBq of (90)Y-RAFT-RAD or 37 MBq of (177)Lu-RAFT-RAD or untreated mice. In contrast, injection of 30 MBq of (90)Y-RAFT-RGD had no effect on the growth of αvβ3-negative tumours. (90)Y-RAFT-RGD and (177)Lu-RAFT-RGD are potent agents targeting αvβ3-expressing tumours for internal targeted radiotherapy.

Synthesis, Structures, and Vibrational Spectroscopy of the Two-Dimensional Iodates Ln(IO) 3 and Ln(IO 3) 3(H 2O) ( Ln-Yb,Lu)

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

Assefa, Zerihun; Ling, Jie; Haire, Richard

2006-01-01

The reaction of Lu3+ or Yb3+ and H5IO6 in aqueous media at 180 C leads to the formation of Yb(IO3)3(H2O) or Lu(IO3)3(H2O), respectively, while the reaction of Yb metal with H5IO6 under similar reaction conditions gives rise to the anhydrous iodate, Yb(IO3)3. Under supercritical conditions Lu3+ reacts with HIO3 and KIO4 to yield the isostructural Lu(IO3)3. The structures have been determined by single-crystal X-ray diffraction. Crystallographic data are (MoKa, {lambda}=0.71073 {angstrom}): Yb(IO3)3, monoclinic, space group P21/n, a=8.6664(9) {angstrom}, b=5.9904(6) {angstrom}, c=14.8826(15) {angstrom}, {beta}=96.931(2){sup o}, V=766.99(13), Z=4, R(F)=4.23% for 114 parameters with 1880 reflections with I>2s(I); Lu(IO3)3, monoclinic, space group P21/n,more » a=8.6410(9), b=5.9961(6), c=14.8782(16) {angstrom}, {beta}=97.028(2){sup o}, V=765.08(14), Z=4, R(F)=2.65% for 119 parameters with 1756 reflections with I>2s(I); Yb(IO3)3(H2O), monoclinic, space group C2/c, a=27.2476(15), b=5.6296(3), c=12.0157(7) {angstrom}, {beta}=98.636(1){sup o}, V=1822.2(2), Z=8, R(F)=1.51% for 128 parameters with 2250 reflections with I>2s(I); Lu(IO3)3(H2O), monoclinic, space group C2/c, a=27.258(4), b=5.6251(7), c=12.0006(16) {angstrom}, {beta}=98.704(2){sup o}, V=1818.8(4), Z=8, R(F)=1.98% for 128 parameters with 2242 reflections with I>2s(I). The f elements in all of the compounds are found in seven-coordinate environments and bridged with monodentate, bidentate, or tridentate iodate anions. Both Lu(IO3)3(H2O) and Yb(IO3)3(H2O) display distinctively different vibrational profiles from their respective anhydrous analogs. Hence, the Raman profile can be used as a complementary diagnostic tool to discern the different structural motifs of the compounds.« less

Growth of Nd doped (Lu, Gd)3(Ga, Al)5O12 single crystal by the micro pulling down method and their scintillation properties

NASA Astrophysics Data System (ADS)

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

2015-03-01

Nd 1 mol% doped (Lu, Gd)3(Ga, Al)5O12 (LGGAG) single crystals were grown by the micro-pulling down (μ-PD) method. Luminescence and scintillation properties such as absorption, excitation and emission spectra, light yield and decay time were evaluated. Nd1%:Lu3Al5O12 showed the highest light output of around 8200 photons/MeV among the grown crystals. Scintillation decay time of Nd:Y3Al5O12 was 1.32 μs (36%) 2.02 μs (64%). Nd:Lu3Ga3Al2O12 was relatively high dense scintillator of 7.38 g/cm3 with good light yield of 6800 photons/MeV and scintillation decay time of 0.20 μs (5%) 2.60 μs (95%).

Phase transformation pathways of ultrafast-laser-irradiated Ln2O3 (Ln =Er -Lu )

NASA Astrophysics Data System (ADS)

Rittman, Dylan R.; Tracy, Cameron L.; Chen, Chien-Hung; Solomon, Jonathan M.; Asta, Mark; Mao, Wendy L.; Yalisove, Steven M.; Ewing, Rodney C.

2018-01-01

Ultrafast laser irradiation causes intense electronic excitations in materials, leading to transient high temperatures and pressures. Here, we show that ultrafast laser irradiation drives an irreversible cubic-to-monoclinic phase transformation in Ln2O3 (Ln =Er -Lu ), and explore the mechanism by which the phase transformation occurs. A combination of grazing incidence x-ray diffraction and transmission electron microscopy are used to determine the magnitude and depth-dependence of the phase transformation, respectively. Although all compositions undergo the same transformation, their transformation mechanisms differ. The transformation is pressure-driven for Ln =Tm -Lu , consistent with the material's phase behavior under equilibrium conditions. However, the transformation is thermally driven for Ln =Er , revealing that the nonequilibrium conditions of ultrafast laser irradiation can lead to novel transformation pathways. Ab initio molecular-dynamics simulations are used to examine the atomic-scale effects of electronic excitation, showing the production of oxygen Frenkel pairs and the migration of interstitial oxygen to tetrahedrally coordinated constitutional vacancy sites, the first step in a defect-driven phase transformation.

Vortex operation in Er:LuYAG crystal laser at ∼1.6 μm

NASA Astrophysics Data System (ADS)

Liu, Qiyao; Zhao, Yongguang; Zhou, Wei; Shen, Deyuan

2017-09-01

An Er3+-doped Lu1.5Y1.5Al5O12 (Er:LuYAG) solid-state laser with direct generation of optical vortex is reported. The vortex laser operation was realized through being pumped by an annular beam at 1532 nm, which was reformatted by a specially fabricated optical mirror. With two different laser output couplers of 10% and 20% transmissions, pure LG01 mode lasers with right-handedness at 1647.7 nm and 1619.5 nm were yielded from a simple two-mirror cavity, respectively, without any helicity control optical element. Furthermore, stable pulse trains at 1647.7 nm have been achieved via employing an acousto-optic Q-switch, and ∼0.66 mJ pulsed energy and ∼65 ns pulse duration were finally obtained at 1 kHz repetition rate, corresponding to a peak power of ∼10.2 kW. The generated pulse vortex maintained LG01 mode with well-determined right-handedness, as in the case of cw laser operation.

Effects of structural distortion induced by Sc substitution in LuFe2O4

NASA Astrophysics Data System (ADS)

Jeong, Jinwon; Noh, Han-Jin; Kim, Sung Baek

2014-06-01

We have studied the correlation between the structural distortion and the electronic/magnetic properties in single-crystalline (Lu,Sc)Fe2O4 (Sc = 0.05 and 0.3) by using X-ray diffraction (XRD), magnetic susceptibility, and X-ray absorption spectroscopy (XAS)/X-ray magnetic circular dichroism (XMCD) measurements. The Rietveld structure analysis of the XRD patterns revealed that the Sc substitution induced an elongation of the FeO5 bipyramidal cages in LuFe2O4 and increased the Fe2O4 bilayer thickness. A non-negligible decrease in the ferrimagnetic transition temperature T C is observed in the magnetic susceptibility curve of the Sc = 0.3 sample, but the XAS/XMCD spectra do not show any difference except for a small reduction of dichroism signals at the Fe3+absorption edge. We interpret this suppression of TC to be the result of a decreased spin-orbit coupling effect in the Fe2+ e 1 g doublet under D 3 h symmetry, which is induced by the weakened structural asymmetry of the FeO5 bipyramids.

Impact of Lu/Gd ratio and activator concentration on structure and scintillation properties of LGSO:Ce crystals

NASA Astrophysics Data System (ADS)

Sidletskiy, O.; Bondar, V.; Grinyov, B.; Kurtsev, D.; Baumer, V.; Belikov, K.; Katrunov, K.; Starzhinsky, N.; Tarasenko, O.; Tarasov, V.; Zelenskaya, O.

2010-02-01

We have studied the dependence of structural and scintillation characteristics of Lu 2 xGd 2-2 xSiO 5:Ce (LGSO:Ce) crystals on cation composition. LGSO:Ce crystals at x=0-1 have been obtained by the Czochralski method. We report here a strong correlation between ionic radii of trivalent cations and their distribution between non-equivalent sites in lattice. By choosing the optimal Lu/Gd ratio and Ce concentration we were able to obtain the light output by˜70%, as compared to LSO:Ce crystals, and energy resolution ˜7 at% 662 KeV ( 137Cs); the afterglow level was decreased by 1-3 orders of magnitude as compared to LSO:Ce. We also discuss the possible mechanisms of control on scintillation characteristics of mixed orthosilicates.

Strain-Induced Ferromagnetism in Antiferromagnetic LuMnO3 Thin Films

NASA Astrophysics Data System (ADS)

White, J. S.; Bator, M.; Hu, Y.; Luetkens, H.; Stahn, J.; Capelli, S.; Das, S.; Döbeli, M.; Lippert, Th.; Malik, V. K.; Martynczuk, J.; Wokaun, A.; Kenzelmann, M.; Niedermayer, Ch.; Schneider, C. W.

2013-07-01

Single phase and strained LuMnO3 thin films are discovered to display coexisting ferromagnetic and antiferromagnetic orders. A large moment ferromagnetism (≈1μB), which is absent in bulk samples, is shown to display a magnetic moment distribution that is peaked at the highly strained substrate-film interface. We further show that the strain-induced ferromagnetism and the antiferromagnetic order are coupled via an exchange field, therefore demonstrating strained rare-earth manganite thin films as promising candidate systems for new multifunctional devices.

Implementation of BT, SP, LU, and FT of NAS Parallel Benchmarks in Java

NASA Technical Reports Server (NTRS)

Schultz, Matthew; Frumkin, Michael; Jin, Hao-Qiang; Yan, Jerry

2000-01-01

A number of Java features make it an attractive but a debatable choice for High Performance Computing. We have implemented benchmarks working on single structured grid BT,SP,LU and FT in Java. The performance and scalability of the Java code shows that a significant improvement in Java compiler technology and in Java thread implementation are necessary for Java to compete with Fortran in HPC applications.

High spin states in 164Lu

NASA Astrophysics Data System (ADS)

Juneja, P.; Gupta, S. L.; Pancholi, S. C.; Kumar, Ashok; Mehta, D.; Chaturvedi, L.; Katoch, S. K.; Malik, S.; Shanker, G.; Bhowmik, R. K.; Muralithar, S.; Rodrigues, G.; Singh, R. P.

1996-03-01

High spin states in the odd-odd 164Lu nucleus have been investigated for the first time, through in-beam gamma-ray spectroscopy, following the 150Sm(19F,5n) reaction at beam energy Elab=105 MeV. Four bands, including two signature split bands are identified. The interpretation of the experimental results is discussed in comparison with the existing data in the neighboring nuclei and in the framework of the cranked shell model. The πh11/2⊗νi13/2 yrast band exhibits anomalous signature splitting and signature inversion is observed at a spin of 18ħ. This provides the missing datum for the systematics of staggering and signature inversion for the neighboring odd-odd N=93 isotones and supports the predictions of angular-momentum projection calculations by Hara and Sun. In the second signature split πh 11/2h9/2 band, the AB neutron crossing occurs at a rotational frequency of ~0.29 MeV. This is indicative of the disappearance of the blocking effect of the odd neutron.

An Implicit LU/AF FDTD Method

NASA Technical Reports Server (NTRS)

Beggs, John H.; Briley, W. Roger

2001-01-01

There has been some recent work to develop two and three-dimensional alternating direction implicit (ADI) FDTD schemes. These ADI schemes are based upon the original ADI concept developed by Peaceman and Rachford and Douglas and Gunn, which is a popular solution method in Computational Fluid Dynamics (CFD). These ADI schemes work well and they require solution of a tridiagonal system of equations. A new approach proposed in this paper applies a LU/AF approximate factorization technique from CFD to Maxwell s equations in flux conservative form for one space dimension. The result is a scheme that will retain its unconditional stability in three space dimensions, but does not require the solution of tridiagonal systems. The theory for this new algorithm is outlined in a one-dimensional context for clarity. An extension to two and threedimensional cases is discussed. Results of Fourier analysis are discussed for both stability and dispersion/damping properties of the algorithm. Results are presented for a one-dimensional model problem, and the explicit FDTD algorithm is chosen as a convenient reference for comparison.

A study of response of a LuYAP:Ce array with innovative assembling for PET

NASA Astrophysics Data System (ADS)

Pani, Roberto; Cinti, Maria Nerina; Scafè, Raffaele; Bennati, Paolo; Lo Meo, Sergio; Preziosi, Enrico; Pellegrini, Rosanna; De Vincentis, Giuseppe; Sacco, Donatella; Fabbri, Andrea

2015-09-01

We propose the characterization of a first array of 10×10 Lutetium Yttrium Orthoaluminate Perovskite (LuYAP:Ce) crystals, 2 mm×2 mm×10 mm pixel size, with an innovative assembling designed to enhance light output, uniformity and detection efficiency. The innovation consists of the use of 0.015 mm thick dielectric coating as inter-pixel light-insulators, manufactured by Crytur (Czech Republic) intended to improve crystal insulation and then light collection. Respect to the traditional treatment with 0.2 mm of white epoxy, a thinner pixel gap enhances packing fraction up to 98% with a consequent improvement of detection efficiency. Spectroscopic characterization of the array was performed by a Hamamatsu R6231 photomultiplier tube. A pixel-by-pixel scanning with a collimated 99mTc radioisotope (140 keV photon energy) highlighted a deviation in pulse height close to 3.5% respect to the overall mean value. Meanwhile, in term of energy resolution a difference between the response of single pixel and the array of about 10% was measured. Results were also supported and validated by Monte Carlo simulations performed with GEANT4. Although the dielectric coating pixel insulator cannot overcome the inherent limitations of LuYAP crystal due to its self-absorption of light (still present), this study demonstrated that the new coating treatment allows better light collection (nearly close to the expected one) with in addition a very good uniformity between different pixels. These results confirm the high potentiality of this coating for any other crystal array suited for imaging application and new expectations for the use of LuYAP for PET systems.

Controllable red, green, blue (RGB) and bright white upconversion luminescence of Lu2O3:Yb3+/Er3+/Tm3+ nanocrystals through single laser excitation at 980 nm.

PubMed

Yang, Jun; Zhang, Cuimiao; Peng, Chong; Li, Chunxia; Wang, Lili; Chai, Ruitao; Lin, Jun

2009-01-01

Light fantastic! Lu(2)O(3):Yb(3+)/Er(3+)/Tm(3+) nanocrystals with controllable red, green, blue (RGB) and bright white upconversion luminescence by a single laser excitation of 980 nm have been successfully synthesized (see picture). Due to abundant UC PL colors, it can potentially be used as fluorophores in the field of color displays, back light, UC lasers, photonics, and biomedicine.Lu(2)O(3):Yb(3+)/Er(3+)/Tm(3+) nanocrystals have been successfully synthesized by a solvothermal process followed by a subsequent heat treatment at 800 degrees C. Powder X-ray diffraction, transmission electron microscopy, upconversion photoluminescence spectra, and kinetic decay were used to characterize the samples. Under single-wavelength diode laser excitation of 980 nm, the bright blue emissions of Lu(2)O(3):Yb(3+), Tm(3+) nanocrystals near 477 and 490 nm were observed due to the (1)G(4)-->(3)H(6) transition of Tm(3+). The bright green UC emissions of Lu(2)O(3):Er(3+) nanocrystals appeared near 540 and 565 nm were observed and assigned to the (2)H(11/2)-->(4)I(15/2) and (4)S(3/2)-->(4)I(15/2) transitions, respectively, of Er(3+). The ratio of the intensity of green luminescence to that of red luminescence decreases with an increase of concentration of Yb(3+) in Lu(2)O(3):Er(3+) nanocrystals. In sufficient quantities of Yb(3+) with resprct to Er(3+), the bright red UC emission of Lu(2)O(3):Yb(3+)/Er(3+) centered at 662 nm was predominant, due to the (4)F(9/2)-->(4)I(15/2) transition of Er(3+). Based on the generation of red, green, and blue emissions in the different doped Lu(2)O(3):RE(3+) nanocrystals, it is possible to produce the luminescence with a wide spectrum of colors, including white, by the appropriate doping of Yb(3+), Tm(3+), and Er(3+) in the present Lu(2)O(3) nanocrystals. Namely, Lu(2)O(3):3 %Yb(3+)/0.2 %Tm(3+)/0.4 %Er(3+) nanocrystals show suitable intensities of blue, green, and red (RGB) emission, resulting in the production of perfect and bright white light

Hypocalcaemia after treatment with [177Lu-DOTA 0,Tyr3]octreotate.

PubMed

van Vliet, Esther I; de Herder, Wouter W; de Rijke, Yolanda B; Zillikens, M Carola; Kam, Boen L R; Teunissen, Jaap J M; Peeters, Robin P; Krenning, Eric P; Kwekkeboom, Dik J

2013-12-01

The aim of this study was to explore the possible mechanisms involved in an observed decline in serum calcium levels in patients with a neuroendocrine tumour (NET) treated with [(177)Lu-DOTA(0),Tyr(3)]octreotate ((177)Lu-octreotate). In 47 patients with NET who were normocalcaemic at baseline, serum calcium, albumin, creatinine, alkaline phosphatase, gamma glutamyl transpeptidase, magnesium, phosphate and 25-hydroxyvitamin D were prospectively analysed at baseline and up to 6 months after treatment. Parathyroid hormone (PTH), 1,25-dihydroxyvitamin D3, type 1 aminoterminal propeptide of procollagen, bone-specific alkaline phosphatase, carboxyterminal crosslinking telopeptide of bone collagen, collagen type I crosslinked N-telopeptide, and creatinine and calcium in 24-h urine samples, were evaluated at baseline and at 3 and 6 months. Another 153 patients with NET were included in a retrospective study to estimate the occurrence of hypocalcaemia in a larger patient group. In the prospectively included patients, the mean serum calcium level decreased significantly after treatment (2.31 ± 0.01 to 2.26 ± 0.02 mmol/l, p = 0.02). Eight patients (17%) showed a marked decrease in serum calcium levels with a nadir of ≤ 2.10 mmol/l. In five patients (11%), calcium substitution therapy was prescribed. PTH increased significantly (5.9 ± 0.6 to 6.7 ± 0.8 pmol/l, p = 0.02), presumably in response to the decreasing serum calcium levels. 25-Hydroxyvitamin D remained stable after treatment. Creatinine levels increased significantly (73 ± 3 to 77 ± 3 μmol/l, p = 0.01), but not enough to explain the hypocalcaemia. Phosphate levels remained unaffected. In the retrospectively analysed patients, the mean serum calcium level decreased significantly from 2.33 ± 0.01 at baseline to a nadir of 2.24 ± 0.01 mmol/l at 18 months after treatment (p < 0.001). Of the 153 patients, 33 (22%) showed a serum calcium nadir of ≤ 2.10 mmol/l, and 11 (7%) received calcium substitution therapy

L -subshell ionization of Ce, Nd, and Lu by 4-10-MeV C ions

NASA Astrophysics Data System (ADS)

Lapicki, G.; Mandal, A. C.; Santra, S.; Mitra, D.; Sarkar, M.; Bhattacharya, D.; Sen, P.; Sarkadi, L.; Trautmann, D.

2005-08-01

Ll,Lα,Lβ,Lγ,Lγ1+5,Lγ2+3,Lγ4+4' x-ray production cross sections of Ce58 , Nd60 and Lu71 induced by 4-, 6-, 8-, and 10-MeV carbon ions were measured. For Lu, Lγ2+3 is separated from Lγ2+3+6 after revision of the technique of Datz so that Lγ1+5 was used instead of Lγ1 , the Lγ4+4'/Lγ1+5 ratio was corrected for multiple ionization, and uncertainties in Lγ4+4' were incorporated in the fitting process. L -subshell ionization cross sections were extracted as a weighted average from two combinations of these cross sections, {Lα,Lγ1+5,Lγ2+3} and {Lα,Lγ1+5,Lγ} . It is shown that, to within a few percent, the first of these two combinations results in the identical cross sections as this weighted average. Within 10%, permutations of different sets of single-hole atomic parameters yielded the same ionization cross sections. These cross sections are typically within 15% and at most 35% of the cross sections obtained with atomic parameters that were altered in two different ways for multiple ionization. Extracted subshell and total L -shell ionization cross sections as well as Ce and Nd data of Braziewicz are compared with the ECPSSR theory of Brandt and Lapicki that accounts for the energy-loss (E), Coulomb-deflection (C), perturbed-stationary-state (PSS) and relativistic (R) effects. These measurements are also compared with the ECPSSR theory after its corrections—in a separated and united atom (USA) treatment, and for the intrashell (IS) transitions with the factors of Sarkadi and Mukoyama normalized to match L -shell cross section with the sum of L -subshell cross sections—as well as with the similarly improved semiclassical approximation of Trautmann. For Ce and Nd, the agreement of the extracted ionization cross sections with these theories is poor for L1 and good for L2 , L3 , and total L shell ionization. For the L2 subshell, this agreement is better for Ce and Nd than for Lu. The ECPSSR theory corrected for the USA and IS effects is surprisingly

Anomalies of magnetoresistance of compounds with atomic clusters RB{sub 12} (R = Ho, Er, Tm, Lu)

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

Sluchanko, N. E., E-mail: nes@lt.gpi.ru; Bogach, A. V.; Glushkov, V. V.

2009-04-15

The magnetoresistance and magnetization of single-crystal samples of rare-earth dodecaborides RB{sub 12} (R = Ho, Er, Tm, Lu) have been measured at low temperatures (1.8-35 K) in a magnetic field of up to 70 kOe. The effect of positive magnetoresistance that obeys the Kohler's rule {delta}{rho}/{rho} = f({rho}(0, 300 K)H/{rho}(0, T)) is observed for the nonmagnetic metal LuB{sub 12}. In the magnetic dodecaborides HoB{sub 12}, ErB{sub 12}, and TmB{sub 12}, three characteristic regimes of the magnetoresistance behavior have been revealed: the positive magnetoresistance effect similar to the case of LuB{sub 12} is observed at T > 25 K; in themore » range T{sub N} {<=} T {<=} 15 K, the magnetoresistance becomes negative and depends quadratically on the external magnetic field; and, finally, upon the transition to the antiferromagnetic phase (T < T{sub N}), the positive magnetoresistance is again observed and its amplitude reaches 150% for HoB{sub 12}. It has been shown that the observed anomalies of negative magnetoresistance in the paramagnetic phase can be explained within the Yosida model of conduction electron scattering by localized magnetic moments. The performed analysis confirms the formation of spin-polaron states in the 5d band in the vicinity of rare-earth ions in paramagnetic and magnetically ordered phases of RB{sub 12} and makes it possible to reveal a number of specific features in the transformation of the magnetic structure of the compounds under investigation.« less

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

NASA Astrophysics Data System (ADS)

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

2012-11-01

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

Syntheses, structures, and vibrational spectroscopy of the two-dimensional iodates Ln(IO 3) 3 and Ln(IO 3) 3(H 2O) ( Lndbnd Yb, Lu)

NASA Astrophysics Data System (ADS)

Assefa, Zerihun; Ling, Jie; Haire, Richard G.; Albrecht-Schmitt, Thomas E.; Sykora, Richard E.

2006-12-01

The reaction of Lu 3+ or Yb 3+ and H 5IO 6 in aqueous media at 180 °C leads to the formation of Yb(IO 3) 3(H 2O) or Lu(IO 3) 3(H 2O), respectively, while the reaction of Yb metal with H 5IO 6 under similar reaction conditions gives rise to the anhydrous iodate, Yb(IO 3) 3. Under supercritical conditions Lu 3+ reacts with HIO 3 and KIO 4 to yield the isostructural Lu(IO 3) 3. The structures have been determined by single-crystal X-ray diffraction. Crystallographic data are (Mo Kα, λ=0.71073 Å): Yb(IO 3) 3, monoclinic, space group P2 1/ n, a=8.6664(9) Å, b=5.9904(6) Å, c=14.8826(15) Å, β=96.931(2)°, V=766.99(13), Z=4, R( F)=4.23% for 114 parameters with 1880 reflections with I>2 σ( I); Lu(IO 3) 3, monoclinic, space group P2 1/ n, a=8.6410(9), b=5.9961(6), c=14.8782(16) Å, β=97.028(2)°, V=765.08(14), Z=4, R( F)=2.65% for 119 parameters with 1756 reflections with I>2 σ( I); Yb(IO 3) 3(H 2O), monoclinic, space group C2/ c, a=27.2476(15), b=5.6296(3), c=12.0157(7) Å, β=98.636(1)°, V=1822.2(2), Z=8, R( F)=1.51% for 128 parameters with 2250 reflections with I>2 σ( I); Lu(IO 3) 3(H 2O), monoclinic, space group C2/ c, a=27.258(4), b=5.6251(7), c=12.0006(16) Å, β=98.704(2)°, V=1818.8(4), Z=8, R( F)=1.98% for 128 parameters with 2242 reflections with I>2 σ( I). The f elements in all of the compounds are found in seven-coordinate environments and bridged with monodentate, bidentate, or tridentate iodate anions. Both Lu(IO 3) 3(H 2O) and Yb(IO 3) 3(H 2O) display distinctively different vibrational profiles from their respective anhydrous analogs. Hence, the Raman profile can be used as a complementary diagnostic tool to discern the different structural motifs of the compounds.

Data-driven discovery of energy materials: efficient BaM2Si3O10 : Eu2+ (M = Sc, Lu) phosphors for application in solid state white lighting.

PubMed

Brgoch, Jakoah; Hasz, Kathryn; Denault, Kristin A; Borg, Christopher K H; Mikhailovsky, Alexander A; Seshadri, Ram

2014-01-01

In developing phosphors for application in solid state lighting, it is advantageous to target structures from databases with highly condensed polyhedral networks that produce rigid host compounds. Rigidity limits channels for non-radiative decay that will decrease the luminescence quantum yield. BaM(2)Si(3)O(10) (M = Sc, Lu) follows this design criterion and is studied here as an efficient Eu(2+)-based phosphor. M = Sc(3+) and Lu(3+) compounds with Eu(2+) substitution were prepared and characterized using synchrotron X-ray powder diffraction and photoluminescence spectroscopy. Substitution with Eu(2+) according to Ba(1-x)Eu(x)Sc(2)Si(3)O(10) and Ba(1-x)Eu(x)Lu(2)Si(3)O(10) results in UV-to-blue and UV-to-blue-green phosphors, respectively. Interestingly, substitution with Eu(2+) in the Lu(3+) containing material produces two emission peaks at low temperature and with 365 nm excitation, as allowed by the two substitution sites. The photoluminescence of the Sc(3+) compound is robust at high temperature, decreasing by only 25% of its room temperature intensity at 503 K, while the Lu-analogue suffers a large drop (75%) from its room temperature intensity. The decrease in emission intensity is explained as stemming from charge transfer quenching due to the short distances separating the luminescent centers on the Lu(3+) substitution site. The correlation between structure and optical response in these two compounds indicates that even though the structures are three-dimensionally connected, high symmetry is required to prevent structural distortions that could impact photoluminescence.

Prevalence and conditions associated with chronic pelvic pain in women from São Luís, Brazil.

PubMed

Coelho, L S C; Brito, L M O; Chein, M B C; Mascarenhas, T S; Costa, J P L; Nogueira, A A; Poli-Neto, O B

2014-09-01

The objective of the present study was to estimate the prevalence of chronic pelvic pain in the community of São Luís, capital of the State of Maranhão, Northeastern Brazil, and to identify independent conditions associated with it. A cross-sectional study was conducted, including a sample of 1470 women older than 14 years predominantly served by the public health system. The interviews were held in the subject's home by trained interviewers not affiliated with the public health services of the municipality. The homes were visited at random according to the city map and the prevalence of the condition was estimated. To identify the associated conditions, the significant variables (P=0.10) were selected and entered in a multivariate analysis model. Data are reported as odds ratio and 95% confidence interval, with the level of significance set at 0.05. The prevalence of chronic pelvic pain was 19.0%. The independent conditions associated with this diagnosis were: dyspareunia (OR=3.94), premenopausal status (OR=2.95), depressive symptoms (OR=2.33), dysmenorrhea (OR=1.77), smoking (OR=1.72), irregular menstrual flow (OR=1.62), and irritative bladder symptoms (OR=1.90). The prevalence of chronic pelvic pain in Sao Luís is high and is associated with the conditions cited above. Guidelines based on prevention and/or early identification of risk factors may reduce the prevalence of chronic pelvic pain in São Luís, Brazil.

Theoretical investigation of the reactivity in the C-F bond activation of CH 3F by Lu + in the gas phase

NASA Astrophysics Data System (ADS)

Liu, Ze-Yu; Wang, Yong-Cheng; Geng, Zhi-Yuan; Yang, Xiao-Yan; Wang, Han-Qing

2006-11-01

The reaction of Lu + with CH 3F, which was selected as a representative system of the activation of C-F bond in fluorohydrocarbons by late lanthanide cations, has been examined using density functional theory (DFT). The potential energy surfaces (PESs) of [Lu, C, H 3, F] + were explored in detail in both singlet and triplet electronic states. The electron-transfer reactivity of the reaction was analyzed using the two-state model, and a strongly avoided crossing behaviour on the transition state (TS) area was shown. The theoretical results can act as a guide to further theoretical and experimental researches.

Manual on the proper use of lutetium-177-labeled somatostatin analogue (Lu-177-DOTA-TATE) injectable in radionuclide therapy (2nd ed.).

PubMed

Hosono, Makoto; Ikebuchi, Hideharu; Nakamura, Yoshihide; Nakamura, Nobutaka; Yamada, Takahiro; Yanagida, Sachiko; Kitaoka, Asami; Kojima, Kiyotaka; Sugano, Hiroyasu; Kinuya, Seigo; Inoue, Tomio; Hatazawa, Jun

2018-04-01

Here we present the guideline for the treatment of neuroendocrine tumors using Lu-177-DOTA-TATE on the basis of radiation safety aspects in Japan. This guideline was prepared by a study supported by Ministry of Health, Labour, and Welfare, and approved by Japanese Society of Nuclear Medicine. Lu-177-DOTA-TATE treatment in Japan should be carried out according to this guideline. Although this guideline is applied in Japan, the issues for radiation protection shown in this guideline are considered internationally useful as well. Only the original Japanese version is the formal document.

Comment on "Reconciliation of the excess 176Hf conundrum in meteorites: Recent disturbances of the Lu-Hf and Sm-Nd isotope systematics" [Geochim. Cosmochim. Acta 212 (2017) 303-323

NASA Astrophysics Data System (ADS)

Bloch, Elias; Watkins, James; Ganguly, Jibamitra

2018-06-01

In a recent paper, Bast et al. (2017) present an impressive set of mineral and whole rock isochrons and use them to investigate the cause(s) of excess 176Hf in eucrite and angrite meteorites. They argue that during terrestrial weathering of these samples, phosphates present as isolated grains or inclusions underwent partial dissolution during which Lu was mobilized more effectively than Hf. If this residual, unsupported Hf were not effectively excluded from analyses, then the data points would be shifted above the actual isochron, creating scatter and potentially spurious Lu-Hf ages. Bast et al. (2017) conclude that: (1) diffusive fractionation of Lu from Hf during a thermal metamorphic event on the parent body, as suggested by Bloch et al. (2017) and Debaille et al. (2011), did not contribute significantly to the anomalous Lu-Hf ages, and (2) terrestrial weathering effects are the primary cause of the older-than-solar-system Lu-Hf mineral ages retrieved from some eucrites and angrites (e.g. Bast et al., 2012; Bizzarro et al., 2012; Lapen et al., 2015; Sanborn et al., 2015). We find these conclusions to be unjustified in light of the authors' selective and incomplete consideration of results from the modeling by Bloch et al. (2017).

LU Factorization with Partial Pivoting for a Multi-CPU, Multi-GPU Shared Memory System

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

Kurzak, Jakub; Luszczek, Pitior; Faverge, Mathieu

2012-03-01

LU factorization with partial pivoting is a canonical numerical procedure and the main component of the High Performance LINPACK benchmark. This article presents an implementation of the algorithm for a hybrid, shared memory, system with standard CPU cores and GPU accelerators. Performance in excess of one TeraFLOPS is achieved using four AMD Magny Cours CPUs and four NVIDIA Fermi GPUs.

STS-84 Mission Specialist Edward Tsang Lu in white room

NASA Technical Reports Server (NTRS)

1997-01-01

KENNEDY SPACE CENTER, FLA. -- STS-84 Mission Specialist Edward T. Lu prepares to enter the Space Shuttle Atlantis at Launch Pad 39A with help from white room closeout crew members. The fourth Shuttle mission of 1997 will be the sixth docking of the Space Shuttle with the Russian Space Station Mir. The commander is Charles J. Precourt. The pilot is Eileen Marie Collins. The five mission specialists are C. Michael Foale, Carlos I. Noriega, Edward Tsang Lu, Jean-Francois Clervoy of the European Space Agency and Elena V. Kondakova of the Russian Space Agency. The planned nine-day mission will include the exchange of Foale for U.S. astronaut and Mir 23 crew member Jerry M. Linenger, who has been on Mir since Jan. 15. Linenger transferred to Mir during the last docking mission, STS-81; he will return to Earth on Atlantis. Foale is slated to remain on Mir for about four months until he is replaced in September by STS-86 Mission Specialist Wendy B. Lawrence. During the five days Atlantis is scheduled to be docked with the Mir, the STS-84 crew and the Mir 23 crew, including two Russian cosmonauts, Commander Vasily Tsibliev and Flight Engineer Alexander Lazutkin, will participate in joint experiments. The STS-84 mission also will involve the transfer of more than 7,300 pounds of water, logistics and science equipment to and from the Mir. Atlantis is carrying a nearly 300-pound oxygen generator to replace one of two Mir units which have experienced malfunctions. The oxygen it generates is used for breathing by the Mir crew.

177Lu-octreotate, alone or with radiosensitising chemotherapy, is safe in neuroendocrine tumour patients previously treated with high-activity 111In-octreotide.

PubMed

Hubble, Daniel; Kong, Grace; Michael, Michael; Johnson, Val; Ramdave, Shakher; Hicks, Rodney John

2010-10-01

The aim of this retrospective study was to determine whether patients with previous peptide receptor radionuclide therapy using high-activity (111)In-pentetreotide can be safely treated with (177)Lu-octreotate and whether addition of radiosensitising chemotherapy increases the toxicity of this agent. Records of 27 patients (aged 17-75) who received 69 (median 3 per patient) (177)Lu-octreotate administrations, including 29 in conjunction with radiosensitising infusional 5-fluorouracil (5-FU) (n = 27), or capecitabine (n = 2), between October 2005 and July 2007 subsequent to 1-8 prior cycles of (111)In-pentetreotide therapy were analysed. Toxicity was assessed during and at 8-12 weeks post-treatment, with further long-term assessments including survival status reviewed till death or study close-out date of 1 November 2009. Reduction in blood counts was most marked following the first dose of (177)Lu-octreotate but at early follow-up the only major haematological toxicity was a single case of grade 4 lymphopaenia. Both the presence of bone metastases and the administration of chemotherapy tended to result in greater reduction in blood counts, but these differences did not reach statistical significance. On long-term follow-up, 16 patients (59%) are alive with median overall survival of 36 months (32-44 months from first (177)Lu-octreotate therapy). None of the recorded deaths was directly related to treatment toxicity. One patient had late grade 4 anaemia and thrombocytopaenia secondary to bone marrow failure from progressive infiltration by tumour. No other significant long-term haematological toxicities were recorded and no leukaemia was observed. No renal toxicity was observed on serial serum creatinine or radionuclide glomerular filtration rate (GFR) determination on initial or long-term follow-up. (177)Lu-octreotate is a safe and well-tolerated therapy for patients who have previously been treated with (111)In-pentetreotide and can be safely combined with

A Randomized Phase 2 Trial of 177Lu Radiolabeled Anti-PSMA Monoclonal Antibody J591 in Patients With High-Risk Castrate Biochemically Relapsed Prostate Cancer

DTIC Science & Technology

2015-09-01

Award Number: W81XWH-09-1-0596 TITLE: A Randomized Phase 2 Trial of 177Lu Radiolabeled Anti- PSMA Monoclonal Antibody J591 in Patients With High...1-0596 A Randomized Phase 2 Trial of 177Lu Radiolabeled Anti- PSMA Monoclonal Antibody J591 in Patients With High-Risk Castrat Biochemically Relapsed...in December 2014 with approval to proceed without modifications. 15. SUBJECT TERMS Prostate cancer, PSA, PSMA , monoclonal antibody

Stochastic local operations and classical communication (SLOCC) and local unitary operations (LU) classifications of n qubits via ranks and singular values of the spin-flipping matrices

NASA Astrophysics Data System (ADS)

Li, Dafa

2018-06-01

We construct ℓ -spin-flipping matrices from the coefficient matrices of pure states of n qubits and show that the ℓ -spin-flipping matrices are congruent and unitary congruent whenever two pure states of n qubits are SLOCC and LU equivalent, respectively. The congruence implies the invariance of ranks of the ℓ -spin-flipping matrices under SLOCC and then permits a reduction of SLOCC classification of n qubits to calculation of ranks of the ℓ -spin-flipping matrices. The unitary congruence implies the invariance of singular values of the ℓ -spin-flipping matrices under LU and then permits a reduction of LU classification of n qubits to calculation of singular values of the ℓ -spin-flipping matrices. Furthermore, we show that the invariance of singular values of the ℓ -spin-flipping matrices Ω 1^{(n)} implies the invariance of the concurrence for even n qubits and the invariance of the n-tangle for odd n qubits. Thus, the concurrence and the n-tangle can be used for LU classification and computing the concurrence and the n-tangle only performs additions and multiplications of coefficients of states.

Phase transformation pathways of ultrafast-laser-irradiated Ln 2 O 3 ( Ln = Er – Lu )

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

Rittman, Dylan R.; Tracy, Cameron L.; Chen, Chien-Hung

Ultrafast laser irradiation causes intense electronic excitations in materials, leading to transient high temperatures and pressures. Here, we show that ultrafast laser irradiation drives an irreversible cubic-to-monoclinic phase transformation in Ln 2O 3 ( Ln = Er – Lu ) , and explore the mechanism by which the phase transformation occurs. A combination of grazing incidence x-ray diffraction and transmission electron microscopy are used to determine the magnitude and depth-dependence of the phase transformation, respectively. Although all compositions undergo the same transformation, their transformation mechanisms differ. The transformation is pressure-driven for Ln = Tm – Lu , consistent with themore » material's phase behavior under equilibrium conditions. However, the transformation is thermally driven for Ln = Er , revealing that the nonequilibrium conditions of ultrafast laser irradiation can lead to novel transformation pathways. Ab initio molecular-dynamics simulations are used to examine the atomic-scale effects of electronic excitation, showing the production of oxygen Frenkel pairs and the migration of interstitial oxygen to tetrahedrally coordinated constitutional vacancy sites, the first step in a defect-driven phase transformation.« less

Phase transformation pathways of ultrafast-laser-irradiated Ln 2 O 3 ( Ln = Er – Lu )

DOE PAGES

Rittman, Dylan R.; Tracy, Cameron L.; Chen, Chien-Hung; ...

2018-01-10

Ultrafast laser irradiation causes intense electronic excitations in materials, leading to transient high temperatures and pressures. Here, we show that ultrafast laser irradiation drives an irreversible cubic-to-monoclinic phase transformation in Ln 2O 3 ( Ln = Er – Lu ) , and explore the mechanism by which the phase transformation occurs. A combination of grazing incidence x-ray diffraction and transmission electron microscopy are used to determine the magnitude and depth-dependence of the phase transformation, respectively. Although all compositions undergo the same transformation, their transformation mechanisms differ. The transformation is pressure-driven for Ln = Tm – Lu , consistent with themore » material's phase behavior under equilibrium conditions. However, the transformation is thermally driven for Ln = Er , revealing that the nonequilibrium conditions of ultrafast laser irradiation can lead to novel transformation pathways. Ab initio molecular-dynamics simulations are used to examine the atomic-scale effects of electronic excitation, showing the production of oxygen Frenkel pairs and the migration of interstitial oxygen to tetrahedrally coordinated constitutional vacancy sites, the first step in a defect-driven phase transformation.« less

XRD and 29Si MAS-NMR spectroscopy across the β-Lu 2Si 2O 7- β-Y 2Si 2O 7 solid solution

NASA Astrophysics Data System (ADS)

Becerro, Ana I.; Escudero, Alberto

2005-01-01

Samples in the system Lu 2-xY xSi 2O 7 (0⩽ x⩽2) have been synthesized following the sol-gel method and calcined to 1300 °C, a temperature at which the β-polymorph is known to be the stable phase for the end-members Lu 2Si 2O 7 and Y 2Si 2O 7. The XRD patterns of all the compositions studied are compatible with the structure of the β-polymorph. Unit cell parameters are calculated as a function of composition from XRD patterns. They show a linear change with increasing Y content, which indicates a solid solubility of β-Y 2Si 2O 7 in β-Lu 2Si 2O 7 at 1300 °C. 29Si MAS NMR spectra of the different members of the system agree with the XRD results, showing a linear decrease of the 29Si chemical shift with increasing Y content. Finally, a correlation reported in the literature to predict 29Si chemical shifts in silicates is applied here to obtain the theoretical variation in 29Si chemical shift values in the system Lu 2Si 2O 7-Y 2Si 2O 7 and the results compare favorably with the values obtained experimentally.

Block matrix based LU decomposition to analyze kinetic damping in active plasma resonance spectroscopy

NASA Astrophysics Data System (ADS)

Roehl, Jan Hendrik; Oberrath, Jens

2016-09-01

``Active plasma resonance spectroscopy'' (APRS) is a widely used diagnostic method to measure plasma parameter like electron density. Measurements with APRS probes in plasmas of a few Pa typically show a broadening of the spectrum due to kinetic effects. To analyze the broadening a general kinetic model in electrostatic approximation based on functional analytic methods has been presented [ 1 ] . One of the main results is, that the system response function Y(ω) is given in terms of the matrix elements of the resolvent of the dynamic operator evaluated for values on the imaginary axis. To determine the response function of a specific probe the resolvent has to be approximated by a huge matrix which is given by a banded block structure. Due to this structure a block based LU decomposition can be implemented. It leads to a solution of Y(ω) which is given only by products of matrices of the inner block size. This LU decomposition allows to analyze the influence of kinetic effects on the broadening and saves memory and calculation time. Gratitude is expressed to the internal funding of Leuphana University.

Maternal socioeconomic factors and adverse perinatal outcomes in two birth cohorts, 1997/98 and 2010, in São Luís, Brazil.

PubMed

Cavalcante, Nádia Carenina Nunes; Simões, Vanda Maria Ferreira; Ribeiro, Marizélia Rodrigues Costa; Lamy-Filho, Fernando; Barbieri, Marco Antonio; Bettiol, Heloisa; Silva, Antônio Augusto Moura da

2017-01-01

Several studies have identified social inequalities in low birth weight (LBW), preterm birth (PTB), and intrauterine growth restriction (IUGR), which, in recent years, have diminished or disappeared in certain locations. Estimate the LBW, PTB, and IUGR rates in São Luís, Maranhão, Brazil, in 2010, and check for associations between socioeconomic factors and these indicators. This study is based on a birth cohort performed in São Luís. It included 5,051 singleton hospital births in 2010. The chi-square test was used for proportion comparisons, while simple and multiple Poisson regression models with robust error variance were used to estimate relative risks. LBW, PTB and IUGR rates were 7.5, 12.2, and 10.3% respectively. LBW was higher in low-income families, while PTB and IUGR were not associated with socioeconomic factors. The absence or weak association of these indicators with social inequality point to improvements in health care and/or in social conditions in São Luís.

High clinical and morphologic response using 90Y-DOTA-octreotate sequenced with 177Lu-DOTA-octreotate induction peptide receptor chemoradionuclide therapy (PRCRT) for bulky neuroendocrine tumours.

PubMed

Kong, Grace; Callahan, Jason; Hofman, Michael S; Pattison, David A; Akhurst, Tim; Michael, Michael; Eu, Peter; Hicks, Rodney J

2017-03-01

Bulky disease is an adverse prognostic factor for 177 Lu-DOTA-octreotate ( 177 Lu-DOTATATE) peptide receptor radionuclide therapy (PRRT). 90 Y-DOTA-octreotate ( 90 Y-DOTATATE) has theoretical advantages in this setting but may less effectively treat co-existent smaller deposits and have higher toxicity than 177 Lu-DOTATATE. The aim of this study was to assess the efficacy and safety of using these agents sequentially. We reviewed patients (pts) with at least one lesion of a transaxial diameter >4 cm who completed 1-2 cycles of 90 Y-DOTATATE followed by 2-3 cycles of 177 Lu-DOTATATE, with treatment empirically adapted to disease size and burden in individual patients. Data collected included morphological and molecular imaging response, toxicity, and progression-free and overall survival. Twenty-six pts (17 men; aged 27-74 years) received a median cumulative activity of 6.5 GBq 90 Y-DOTATATE, and 21 GBq 177 Lu-DOTATATE. All but one received radiosensitising chemotherapy. Adverse prognostic factors included ENETS grade 2 or 3 in 58 %, and FDG-avid disease in 73 %. Nineteen pts treated for progressive disease had stabilisation (37 %) or regression on CT (42 % partial response, 21 % minor response), with a mean 59 % (8-99 %) reduction in disease burden. All seven pts treated for uncontrolled symptoms reported improvement during PRRT with 4/7 having complete symptom resolution at 3 months. Eight patients had grade 3/4 lymphopaenia, and two patients grade 3/4 thrombocytopaenia without significant hepatic or renal toxicity. Median survival was not reached after a median follow-up of 35 months. Median progression-free survival was 33 months. PRCRT with 90 Y -DOTATATE followed by 177 Lu-DOTATATE in individualised regimens achieved high clinical and morphological response in patients with bulky tumours. Despite lack of a control arm, the efficacy of this treatment approach appears higher than reported results with either agent used alone or other approved

Formation of medical radioisotopes 111In, 117 m Sn, 124Sb, and 177Lu in photonuclear reactions

NASA Astrophysics Data System (ADS)

Danagulyan, A. S.; Hovhannisyan, G. H.; Bakhshiyan, T. M.; Avagyan, R. H.; Avetisyan, A. E.; Kerobyan, I. A.; Dallakyan, R. K.

2015-06-01

The possibility of the photonuclear production of radioisotopes 111In, 117 m Sn, 124Sb, and 177Lu is discussed. Reaction yields were measured by the gamma-activation method. The enriched tin isotopes 112, 118Sn and Te and HfO2 of natural isotopic composition were used as targets. The targets were irradiated at the linear electron accelerator of Alikhanian National Science Laboratory (Yerevan) at the energy of 40 MeV. The experimental results obtained in this way reveal that the yield and purity of radioisotopes 111In and 117 mSn are acceptable for their production via photonuclear reactions. Reactions proceeding on targets from Te and HfO2 of natural isotopic composition and leading to the formation of 124Sb and 177Lu have small yields and are hardly appropriate for the photoproduction of these radioisotopes even in the case of enriched targets.

On the effective implementation of a boundary element code on graphics processing units unsing an out-of-core LU algorithm

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

D'Azevedo, Ed F; Nintcheu Fata, Sylvain

2012-01-01

A collocation boundary element code for solving the three-dimensional Laplace equation, publicly available from \\url{http://www.intetec.org}, has been adapted to run on an Nvidia Tesla general purpose graphics processing unit (GPU). Global matrix assembly and LU factorization of the resulting dense matrix were performed on the GPU. Out-of-core techniques were used to solve problems larger than available GPU memory. The code achieved over eight times speedup in matrix assembly and about 56~Gflops/sec in the LU factorization using only 512~Mbytes of GPU memory. Details of the GPU implementation and comparisons with the standard sequential algorithm are included to illustrate the performance ofmore » the GPU code.« less

Multitasking the INS3D-LU code on the Cray Y-MP

NASA Technical Reports Server (NTRS)

Fatoohi, Rod; Yoon, Seokkwan

1991-01-01

This paper presents the results of multitasking the INS3D-LU code on eight processors. The code is a full Navier-Stokes solver for incompressible fluid in three dimensional generalized coordinates using a lower-upper symmetric-Gauss-Seidel implicit scheme. This code has been fully vectorized on oblique planes of sweep and parallelized using autotasking with some directives and minor modifications. The timing results for five grid sizes are presented and analyzed. The code has achieved a processing rate of over one Gflops.

HYPERFINE STRUCTURES AND NUCLEAR MOMENTS OF Lu$sup 176$m, Br$sup 80$, Br$sup 80$m, AND I$sup 132$ (thesis)

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

White, M.B.

1962-09-01

The method of atomic-beam radiofrequency spectroscopy was used to determine some nuclear and atomic properties of Lu/sup 176m/, Br/sup 80/, Br/sup 80m/, and I/sup 132/. Hyperfine structure me asurements were raade to determine the magnetic dipole interaction constants and the electric quadrupole interaction constants of all these isotopes. Also the nuclear spin and the electronic g/sub J/ factor were measured for Lu/sup 176m/, and the nuclear magnetic dipole moments and the electric quadrupole moments for the isotopes were calculated. All results are listed. 62 references. (auth)

Analysis of spatial pattern Change of LU/LC over the upper Tarim River region since 1990 using remote sensing data

NASA Astrophysics Data System (ADS)

Bai, L. Y.; Feng, J. Z.; Ma, Y. X.; Ran, Q. Y.; Wang, K.; Zhao, Y.

2017-02-01

The upper reaches of Tarim River (URTR) is an important port of trade between China and central Asia. The development of the URTR is thus significant for the SREB initiative. The LU/LC data in the URTR from 1990 to 2015 were used to quantitatively explore the dynamics of LU/LC changes, and its driving force was discussed from two aspects of nature and human. Results showed that the unused land and grassland were the main land use types in this area, accounting for more than 79%. Compared with the data of 1990, the areas of woodland, water, farmland, and building land of 2015 increased with 3.24%, 6.53%, 10.57%, and 0.40%, respectively, and the areas of unused land and grassland decreased, which accounted for 53.25% and 26.01%, respectively. The increases of the woodland and farmland areas mainly is originated from grassland and unused land. The woodland increased sharply around 2000 due to the abundant water during the period between 1998 and 2000. Subsequently, part of the woodland was shifted into the farmland. The extension of building land wasn’t obvious, but showed a salient feature of population urbanization. It was essential that the LU/LC patterns of the URTR were deeply influenced by human farming and living activities.

Preparation and Scintillating Properties of Sol-Gel Eu3+, Tb3+ Co-Doped Lu2O3 Nanopowders

PubMed Central

de Jesús Morales Ramírez, Ángel; Murillo, Antonieta García; de Jesús Carrillo Romo, Felipe; Hernández, Margarita García; Palmerin, Joel Moreno; Guerrero, Rosario Ruiz

2011-01-01

Nanocrystalline Eu3+, Tb3+ co-doped Lu2O3 powders with a maximum size of 25.5 nm were prepared by the sol-gel process, using lutetium, europium and terbium nitrates as precursors, and ethanol as a solvent. Differential thermal analysis (DTA) and infrared spectroscopy (IR) were used to study the chemical changes during the xerogel annealing. After the sol evaporation at 100 °C, the formed gel was annealed from 300 to 900 °C for 30 min under a rich O2 atmosphere, and the yielded product was analyzed by X-ray diffraction (XRD) to characterize the microstructural behavior and confirm the crystalline structure. The results showed that Lu2O3 nanopowders start to crystallize at 400 °C and that the crystallite size increases along with the annealing temperature. A transmission electron microscopy (TEM) study of samples annealed at 700 and 900 °C was carried out in order to analyze the microstructure, as well as the size, of crystallites. Finally, in regard to scintillating properties, Eu3+ dopant (5 mol%), Tb3+ codoped Lu2O3 exhibited a typical red emission at 611 nm (D°→7F2), furthermore, the effect of Tb3+ molar content (0.01, 0.015 and 0.02% mol) on the Eu3+ radioluminiscence was analyzed and it was found that the higher emission intensity corresponds to the lower Tb3+ content. PMID:22016655

Luminescent properties and energy transfer studies of color-tunable LuBO{sub 3}: Ce{sup 3+}/Tb{sup 3+}/Eu{sup 3+} phosphors

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

Zhang, Xinguo, E-mail: sysuzxg@gmail.com; School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004; Fu, Xionghui

Highlights: • A series of color-tunable LuBO{sub 3}: Ce{sup 3+}/Tb{sup 3+}/Eu{sup 3+} phosphors were synthesized. • Phosphors exhibit strong blue/green/red emission under UV excitation. • The reason of high Tb{sup 3+} content required for Ce{sup 3+} → Tb{sup 3+} → Eu{sup 3+} energy transfer is unveiled. • Green and red LED prototypes were fabricated and characterized. - Abstract: A series of LuBO{sub 3}: Ce{sup 3+}/Tb{sup 3+}/Eu{sup 3+} phosphors were synthesized via solid state reaction. The Ce{sup 3+}/Tb{sup 3+} co-doped and Ce{sup 3+}/Tb{sup 3+}/Eu{sup 3+} tri-doped phosphors absorb near UV light through 4f-5d transitions of Ce{sup 3+}, followed by sensitized Tb{supmore » 3+} green and Eu{sup 3+} red emission. Decay curves investigations for samples with various Tb{sup 3+} and Eu{sup 3+} contents reveal the occurrence of Ce{sup 3+} → Tb{sup 3+} → Eu{sup 3+} energy transfer. It is found that due to relative low Tb{sup 3+} → Eu{sup 3+} energy transfer rate, a high Tb{sup 3+} content (>40%) is required for efficient Ce{sup 3+} → Tb{sup 3+} → Eu{sup 3+} energy transfer. Emission color of LuBO{sub 3}: Ce{sup 3+}, Tb{sup 3+}, Eu{sup 3+} varies from blue through green to red with Ce{sup 3+}/Tb{sup 3+}/Eu{sup 3+} ratio. The quantum efficiency of LuBO{sub 3}: Ce{sup 3+}, Tb{sup 3+} green phosphor and LuBO{sub 3}: Ce{sup 3+}, Tb{sup 3+}, Eu{sup 3+} red phosphor is 50% and 30%, respectively. Green and red LED prototypes were fabricated. The results show that the obtained phosphors are potential candidates as down-converted phosphors for NUV LEDs.« less

Higher titers of some H5N1 and recent human H1N1 and H3N2 influenza viruses in Mv1 Lu vs. MDCK cells

PubMed Central

2011-01-01

Background The infectivity of influenza A viruses can differ among the various primary cells and continuous cell lines used for such measurements. Over many years, we observed that all things equal, the cytopathic effects caused by influenza A subtype H1N1, H3N2, and H5N1 viruses were often detected earlier in a mink lung epithelial cell line (Mv1 Lu) than in MDCK cells. We asked whether virus yields as measured by the 50% tissue culture infectious dose and plaque forming titer also differed in MDCK and Mv1 Lu cells infected by the same influenza virus subtypes. Results The 50% tissue culture infectious dose and plaque forming titer of many influenza A subtype H1N1, H3N2, and H5N1 viruses was higher in Mv1 Lu than in MDCK cells. Conclusions The yields of influenza subtype H1N1, H3N2, and H5N1 viruses can be higher in Mv1 Lu cells than in MDCK cells. PMID:21314955

Malenchenko and Lu in Pirs Docking Compartment (DC-1) module

NASA Image and Video Library

2003-10-20

ISS007-E-17761 (20 October 2003) --- The Expedition 7 crewmembers, cosmonaut Yuri I. Malenchenko, mission commander representing Rosaviakosmos; and astronaut Edward T. Lu, NASA ISS science officer and flight engineer, pose for a photo by a camera triggered for a change by something other than auto-set or remote means. The photographer in this case was one of the newly arrived Expedition 8 crewmembers, astronaut C. Michael Foale, American commander and NASA ISS science officer and cosmonaut Alexander Kaleri, Russian flight engineer and Soyuz commander; or possibly European Space Agency astronaut Pedro Duque, who joined the Expedition 8 crew for the trip "up" and who will return to Earth on Oct. 28 with the Expedition 7 crew.

2.7 MeV Ar11+ ion irradiation induced structural evolution in Lu2(Ti2-xLux)O7-x/2 pyrochlores

NASA Astrophysics Data System (ADS)

Yang, D. Y.; Liu, C. G.; Zhang, K. Q.; Xia, Y.; Chen, L. J.; Liu, H.; Li, Y. H.

2015-11-01

This paper aims to study the radiation effects of nonstoichiometric pyrochlore series Lu2(Ti2-xLux)O7-x/2 (x = 0-0.667). Polycrystalline Lu2(Ti2-xLux)O7-x/2 samples were irradiated with 2.7 MeV Ar11+ ions up to a fluence of 8 × 1014 ions/cm2. The irradiated samples were characterized using grazing incidence X-ray diffraction technique. The results reveal that Lu2(Ti2-xLux)O7-x/2 samples undergo significant amorphization and lattice swelling upon irradiation. Specifically, the amorphization process is predominantly driven by ballistic nuclear energy deposition of Ar11+ ions at this energy regime, which can be well described by a direct-impact/defect-stimulated model. Both the amorphization fraction and the relative variation of lattice parameter decrease with increasing x, showing a strong dependence on the chemical composition. The results are then discussed in the framework of the structural disorder and recovery ability from damage, applying an atomic layer model.

Phase II trial of yttrium-90-DOTA-biotin pretargeted by NR-LU-10 antibody/streptavidin in patients with metastatic colon cancer

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

Knox, S J.; Goris, M L.; Tempero, M

A Phase II study of yttrium-90-tetra-azacyclododecanetetra-acetic acid-biotin (Y-90-DOTA-biotin) pretargeted by NR-LU-10 antibody/streptavidin (SA) was performed. The primary objectives of the study were to evaluate the efficacy and safety of this therapy in patients with metastatic colon cancer. Twenty-five patients were treated with a single dose of 110 mCi/m{sup 2} (mean administered dose, 106.5-10.3 mCi/m{sup 2}) of Y-90-DOTA-biotin. There were three components of the therapy. Patients first received NR-LU-10/SA on day 1. A clearing agent (biotin-galactose-human serum albumin) was administered 48 h after the NR-LU-10/SA to remove residual circulating unbound NR-LU-10/SA. Lastly, 24 h after administration of clearing agent, patients receivedmore » biotin-DOTA-labeled with 110 mCi/m{sup 2} Y-90. All three components of the therapy were administered i.v. Both hematological and nonhematological toxicities were observed. Diarrhea was the most frequent grade 4 nonhematological toxicity (16%; with 16% grade 3 diarrhea). Hematological toxicity was less severe with 8% grade 3 and 8% grade 4 neutropenia and 8% grade 3 and 16% grade 4 thrombocytopenia. The overall response rate was 8%. Two partial responders had freedom from progression of 16 weeks. Four patients (16%) had stable disease with freedom from progression of 10-20 weeks. Despite the relatively disappointing results of this study in terms of therapeutic efficacy and toxicity, proof of principle was obtained for the pretargeting approach. In addition, valuable new information was obtained about normal tissue tolerance to low-dose-rate irradiation that will help to provide useful guidelines for future study designs.« less

Characterization of ErAs:GaAs and LuAs:GaAs Superlattice Structures for Continuous-Wave Terahertz Wave Generation through Plasmonic Photomixing

NASA Astrophysics Data System (ADS)

Yang, Shang-Hua; Salas, Rodolfo; Krivoy, Erica M.; Nair, Hari P.; Bank, Seth R.; Jarrahi, Mona

2016-07-01

We investigate the impact of ErAs:GaAs and LuAs:GaAs superlattice structures with different LuAs/ErAs nanoparticle depositions and superlattice geometries on terahertz radiation properties of plasmonic photomixers operating at a 780-nm optical wavelength. Our analysis indicates the crucial impact of carrier drift velocity and carrier lifetime on the performance of plasmonic photomixers. While higher carrier drift velocities enable higher optical-to-terahertz conversion efficiencies by offering higher quantum efficiencies, shorter carrier lifetimes allow achieving higher optical-to-terahertz conversion efficiencies by mitigating the negative impact of destructive terahertz radiation from slow photocarriers and preventing the carrier screening effect.

Uncertainty propagation for SPECT/CT-based renal dosimetry in 177Lu peptide receptor radionuclide therapy

NASA Astrophysics Data System (ADS)

Gustafsson, Johan; Brolin, Gustav; Cox, Maurice; Ljungberg, Michael; Johansson, Lena; Sjögreen Gleisner, Katarina

2015-11-01

A computer model of a patient-specific clinical 177Lu-DOTATATE therapy dosimetry system is constructed and used for investigating the variability of renal absorbed dose and biologically effective dose (BED) estimates. As patient models, three anthropomorphic computer phantoms coupled to a pharmacokinetic model of 177Lu-DOTATATE are used. Aspects included in the dosimetry-process model are the gamma-camera calibration via measurement of the system sensitivity, selection of imaging time points, generation of mass-density maps from CT, SPECT imaging, volume-of-interest delineation, calculation of absorbed-dose rate via a combination of local energy deposition for electrons and Monte Carlo simulations of photons, curve fitting and integration to absorbed dose and BED. By introducing variabilities in these steps the combined uncertainty in the output quantity is determined. The importance of different sources of uncertainty is assessed by observing the decrease in standard deviation when removing a particular source. The obtained absorbed dose and BED standard deviations are approximately 6% and slightly higher if considering the root mean square error. The most important sources of variability are the compensation for partial volume effects via a recovery coefficient and the gamma-camera calibration via the system sensitivity.

Rattling induced superconductivity in RV2Al20 (R = Sc, Lu, Y) aluminides - an experimental and theoretical study

NASA Astrophysics Data System (ADS)

Winiarski, Michal; Wiendlocha, Bartlomiej; Sternik, Malgorzata; Wisniewski, Piotr; Kaczorowski, Dariusz; Klimczuk, Tomasz

Polycrystalline samples of four ternary intermetallics RV2Al20 (R = Sc, Y, La, and Lu) were synthesized. Structural studies carried out using powder x-ray diffraction and Rietveld analysis show that all compounds crystallize in CeCr2Al20-type structure composed of icosahedral Al-R cages. Results of physical properties measurements reveal that ScV2Al20, YV2Al20, and LuV2Al20 are weakly-coupled BCS superconductors with critical temperatures Tc = 1.0, 0.57, and 0.60 K, respectively. Electronic and phonon structure calculations reveal the key role of low-frequency anharmonic vibrations of R atoms (rattling effect) for the appearance of superconductivity. A correlation between phonon and crystal structures was observed, allowing to search for new RV2Al20 superconductors. Project was financially supported by the National Science Centre (Poland) Grant (DEC-2012/07/E/ST3/00584).

Highly stable self-pulsed operation of an Er:Lu2O3 ceramic laser at 2.7 µm

NASA Astrophysics Data System (ADS)

Wang, Li; Huang, Haitao; Shen, Deyuan; Zhang, Jian; Chen, Hao; Tang, Dingyuan

2017-04-01

We report on the highly stable self-pulsed operation of a 2.74 µm Er:Lu2O3 ceramic laser pumped by a wavelength locked narrow bandwidth 976 nm laser diode. The operating pulse repetition rate is continuously tunable from 126 kHz to 270 kHz depending on the pump power level. For 12.3 W of absorbed diode pump power, the Er:Lu2O3 ceramic laser generates 820 mW of average output power at a 270 kHz repetition rate and with a pulse duration of 183 ns. The corresponding pulse-to-pulse amplitude fluctuation is estimated to be less than 0.7%. In the continues-wave (CW) mode of operation, the laser yields over 1.3 W of output power with a slope efficiency of 11.9% with respect to the 976 nm pump power.

Preparation of therapeutic dose of 177Lu-DOTA-TATE using a novel single vial freeze-dried kit: a comparison with 'in-situ' preparation at hospital radiopharmacy.

PubMed

Das, Tapas; Banerjee, Sharmila; Shinto, Ajit; Kamaleshwaran, K K; Sarma, H D

2014-01-01

Patient dose of (177)Lu-DOTA-TATE, used for providing radiotherapeutic treatment to the patients suffering from cancers of neuroendocrine origin, could be prepared at the hospital radiopharmacy either 'in-situ' or by using freezedried kits. The objective of the present work is to formulate and evaluate a single vial freeze-dried DOTA-TATE kit, which is capable of producing up to 7.4 GBq (200 mCi) dose of (177)Lu-DOTA-TATE and to compare the two methodologies presently used for the preparation of the agent. Freeze-dried DOTA-TATE kits, comprising a lyophilized mixture of DOTA-TATE, gentisic acid and ammonium acetate, were prepared and used for the formulation of patient doses of (177)Lu-DOTA-TATE. The kits were subjected to detailed radiochemical evaluation and the shelf-life of the kits was determined. The pharmacokinetic behavior of the agent was studied in normal Wistar rats. These kits were utilized for treating the patients suffering from various types of neuroendocrine cancers. The freeze-dried kits were used for the preparation of up to 7.4 GBq (200 mCi) therapeutic doses of (177)Lu- DOTA-TATE with a radiochemical purity of >99% and were found to have sufficiently long shelf-life. Biological studies carried out in normal Wistar rats exhibited no significant accumulation of activity in any of the vital organs/tissue except in kidneys and non-accumulated activity showed major renal clearance. Clinical studies carried out in cancer patients exhibited accumulation of activity in the cancerous lesions and metastatic sites. The kit was useful for the convenient preparation of therapeutic dose of (177)Lu-DOTA-TATE, suitable for human administration. The use of kit is expected to reduce the batch failure and radiation exposure to the working personnel.

In vivo enzyme inhibition improves the targeting of [177Lu]DOTA-GRP(13-27) in GRPR-positive tumors in mice.

PubMed

Marsouvanidis, Panteleimon J; Melis, Marleen; de Blois, Erik; Breeman, Wout A P; Krenning, Eric P; Maina, Theodosia; Nock, Berthold A; de Jong, Marion

2014-11-01

Gastrin-releasing peptide receptors (GRPR) and GRP-derived analogs have attracted attention due to high receptor expression in frequently occurring human neoplasia. The authors recently synthesized a series of GRPR-affine peptide analogs based on the 27-mer GRP and derivatized with the DOTA chelator at the N-terminus for (111)In-labeling. In this study, the authors evaluated the most promising from these series, DOTA-GRP(13-27), after radiolabeling with (177)Lu for future therapeutic applications. In addition, to improve in vivo stability of the peptide against in vivo degradation by the protease neutral endopeptidase (NEP), the authors coinjected [(177)Lu]DOTA-GRP(13-27) with the potent NEP inhibitor phosphoramidon (PA). The authors also aimed at reducing renal uptake by coadministration of lysine. In vivo stability studies were performed in Swiss albino mice. Biodistribution studies were conducted in NMRI nu/nu mice bearing prostate cancer (PC)-3 xenografts. Ex vivo autoradiography was performed using frozen sections from PC-3 xenografts and kidneys. Coadministration of PA significantly increased the percentage of intact radiopeptide in the mouse circulation. From biodistribution and ex vivo autoradiography studies, coadministration of both lysine and PA with [(177)Lu]DOTA-GRP(13-27) appeared to induce a clear improvement of tumor uptake as well as lower levels of renal radioactivity, causing a promising ninefold increase in tumor/kidney ratios.

BRCA2 Mutation as a Possible Cause of Poor Response to 177Lu-PSMA Therapy.

PubMed

Ahmadzadehfar, Hojjat; Gaertner, Florian; Lossin, Philipp S; Schwarz, Bettina; Essler, Markus

2018-05-14

We present the case of a 66-year-old man with castration-resistant prostate cancer, with an increasing prostate-specific antigen level, and a progressive disease during Lu-PSMA radionuclide therapy. Because the patient had a BRCA2 mutation, poly-ADP ribose polymerase inhibitor therapy was started. The patient showed a dramatic subjective and biological response to this therapy with a progression-free survival of 5 months.

Safety of multiple repeated cycles of 177Lu-octreotate in patients with recurrent neuroendocrine tumour.

PubMed

Yordanova, Anna; Mayer, Karin; Brossart, Peter; Gonzalez-Carmona, Maria A; Strassburg, Christian P; Essler, Markus; Ahmadzadehfar, Hojjat

2017-07-01

Peptide receptor radionuclide therapy (PRRT) is an effective therapy in patients with a somatostatin receptor-positive neuroendocrine tumour (NET). Still unclear is how many cycles of 177 Lu-octreotate can be repeated while maintaining an acceptable toxicity profile. The purpose of this study was to assess the safety of repeated PRRT in patients with recurrent NET. We retrospectively evaluated data from 15 patients treated with repeated PRRT between 2004 and 2015. The median administered activity was 63.8 GBq (range 52-96.6 GBq) in a median of 9 cycles (range 8-13 cycles). Nonhaematological and haematological toxicities were assessed from clinical reports and laboratory data. The rates of adverse events in three therapy groups were compared: during cycles 1 to 4, cycles 5 to 8, and cycles 9 to 13. Baseline laboratory assessments were also compared with data obtained at the end of treatment. The overall survival in the study patients was compared with survival data in patients who received only a baseline PRRT of three or four cycles. We observed no life-threatening adverse events (CTC-4) during 177 Lu-octreotate treatment. Reversible haematological toxicity (CTC-3) occurred in two patients (13%). No CTC-3/4 nephrotoxicity was recorded. More CTC-3 adverse events were recorded in the first therapy group than in the other two groups. Furthermore, there were no significant changes in the mean values of thrombocytes, leucocytes and serum creatinine before and after therapy. However, the mean haemoglobin levels fell from 14 g/dL to 11 g/dL. Finally, compared with those patients who received three or four cycles, there was a survival benefit in patients treated with repeated PRRT (censored overall survival 85.6 vs. 69.7 months, p < 0.001). Therapy with eight or more cycles of 177 Lu-octreotate was well tolerated and led to a survival benefit in patients with recurrent NET.

Structural, bonding, and electronic properties of the hexagonal ferroelectric and paraelectric phases of LuMnO{sub 3} compound: A density functional theory study

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

Sousa, A. M.; Coutinho, W. S.; Lima, A. F.

2015-02-21

We have investigated the structural, bonding, and electronic properties of both ferroelectric (FE) and paraelectric (PE) phases of the hexagonal LuMnO{sub 3} compound using calculations based on density functional theory. The structural properties have been determined by employing the generalized gradient approximation with Perdew-Burke-Ernzerhof and Wu-Cohen parameterization. The bonding and electronic properties have been treated by recently developed modified Becke-Johnson exchange potential, which succeeded to open a band gap for both PE and FE phases, in agreement with experimental predictions. The Bader’s topological analysis of electronic density showed that the character of the Lu–O axial bonds changes when the crystalmore » exhibits the PE → FE structural transition. This fact is in agreement with experimental findings. The covalent character of the Lu–O bond significantly increases due to orbital hybridization between the Lu 5d{sub z}{sup 2} and O 2p{sub z}-states. This bonding mechanism causes the ferroelectricity in the hexagonal LuMnO{sub 3} compound.« less

Skin dose saving of the staff in 90Y/177Lu peptide receptor radionuclide therapy with the automatic dose dispenser.

PubMed

Fioroni, Federica; Grassi, Elisa; Giorgia, Cavatorta; Sara, Rubagotti; Piccagli, Vando; Filice, Angelina; Mostacci, Domiziano; Versari, Annibale; Iori, Mauro

2016-10-01

When handling Y-labelled and Lu-labelled radiopharmaceuticals, skin exposure is mainly due to β-particles. This study aimed to investigate the equivalent dose saving of the staff when changing from an essentially manual radiolabelling procedure to an automatic dose dispenser (ADD). The chemist and physician were asked to wear thermoluminescence dosimeters on their fingertips to evaluate the quantity of Hp(0.07) on the skin. Data collected were divided into two groups: before introducing ADD (no ADD) and after introducing ADD. For the chemist, the mean values (95th percentile) of Hp(0.07) for no ADD and ADD are 0.030 (0.099) and 0.019 (0.076) mSv/GBq, respectively, for Y, and 0.022 (0.037) and 0.007 (0.023) mSv/GBq, respectively, for Lu. The reduction for ADD was significant (t-test with P<0.05) for both isotopes. The relative differences before and after ADD collected for every finger were treated using the Wilcoxon test, proving a significantly higher reduction in extremity dose to each fingertip for Lu than for Y (P<0.05). For the medical staff, the mean values of Hp(0.07) (95th percentile) for no ADD and ADD are 0.021 (0.0762) and 0.0143 (0.0565) mSv/GBq, respectively, for Y, and 0.0011 (0.00196) and 0.0009 (0.00263) mSv/GBq, respectively, for Lu. The t-test provided a P-value less than 0.05 for both isotopes, making the difference between ADD and no ADD significant. ADD positively affects the dose saving of the chemist in handling both isotopes. For the medical staff not directly involved with the introduction of the ADD system, the analysis shows a learning curve of the workers over a 5-year period. Specific devices and procedures allow staff skin dose to be limited.

Report to the U.S. Congress on the Outcomes of the Nonmotorized Transportation Pilot Program SAFETEA-LU Section 1807

DOT National Transportation Integrated Search

2012-04-30

Section 1807 of the Safe, Accountable, Flexible Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) P.L. 109-59 established the Nonmotorized Transportation Pilot Program (NTPP) in August 2005. Over the span of 4 years, the NTPP provi...

Labelling of 90Y- and 177Lu-DOTA-Bioconjugates for Targeted Radionuclide Therapy: A Comparison among Manual, Semiautomated, and Fully Automated Synthesis.

PubMed

Iori, Michele; Capponi, Pier C; Rubagotti, Sara; Esposizione, Luca Rosario; Seemann, Johanna; Pitzschler, Riccardo; Dreger, Thorsten; Formisano, Debora; Grassi, Elisa; Fioroni, Federica; Versari, Annibale; Asti, Mattia

2017-01-01

In spite of the hazard due to the radiation exposure, preparation of 90 Y- and 177 Lu-labelled radiopharmaceuticals is still mainly performed using manual procedures. In the present study the performance of a commercial automatic synthesizer based on disposable cassettes for the labelling of 177 Lu- and 90 Y-DOTA-conjugated biomolecules (namely, DOTATOC and PSMA-617) was evaluated and compared to a manual and a semiautomated approach. The dose exposure of the operators was evaluated as well. More than 300 clinical preparations of both 90 Y- and 177 Lu-labelled radiopharmaceuticals have been performed using the three different methods. The mean radiochemical yields for 90 Y-DOTATOC were 96.2 ± 4.9%, 90.3 ± 5.6%, and 82.0 ± 8.4%, while for 177 Lu-DOTATOC they were 98.3%  ± 0.6, 90.8%  ± 8.3, and 83.1 ± 5.7% when manual, semiautomated, and automated approaches were used, respectively. The mean doses on the whole hands for yttrium-90 preparations were 0.15 ± 0.4 mSv/GBq, 0.04 ± 0.1 mSv/GBq, and 0.11 ± 0.3 mSv/GBq for manual, semiautomated, and automated synthesis, respectively, and for lutetium-177 preparations, they were 0.02 ± 0.008 mSv/GBq, 0.01 ± 0.03 mSv/GBq, and 0.01 ± 0.02 mSv/GBq, respectively. In conclusion, the automated approach guaranteed reliable and reproducible preparations of pharmaceutical grade therapeutic radiopharmaceuticals in a decent RCY. The radiation exposure of the operators remained comparable to the manual approach mainly due to the fact that a dedicated shielding was still not available for the system.

Sci—Thur AM: YIS - 03: irtGPUMCD: a new GPU-calculated dosimetry code for {sup 177}Lu-octreotate radionuclide therapy of neuroendocrine tumors

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

Montégiani, Jean-François; Gaudin, Émilie; Després, Philippe

2014-08-15

In peptide receptor radionuclide therapy (PRRT), huge inter-patient variability in absorbed radiation doses per administered activity mandates the utilization of individualized dosimetry to evaluate therapeutic efficacy and toxicity. We created a reliable GPU-calculated dosimetry code (irtGPUMCD) and assessed {sup 177}Lu-octreotate renal dosimetry in eight patients (4 cycles of approximately 7.4 GBq). irtGPUMCD was derived from a brachytherapy dosimetry code (bGPUMCD), which was adapted to {sup 177}Lu PRRT dosimetry. Serial quantitative single-photon emission computed tomography (SPECT) images were obtained from three SPECT/CT acquisitions performed at 4, 24 and 72 hours after {sup 177}Lu-octreotate administration, and registered with non-rigid deformation of CTmore » volumes, to obtain {sup 177}Lu-octreotate 4D quantitative biodistribution. Local energy deposition from the β disintegrations was assumed. Using Monte Carlo gamma photon transportation, irtGPUMCD computed dose rate at each time point. Average kidney absorbed dose was obtained from 1-cm{sup 3} VOI dose rate samples on each cortex, subjected to a biexponential curve fit. Integration of the latter time-dose rate curve yielded the renal absorbed dose. The mean renal dose per administered activity was 0.48 ± 0.13 Gy/GBq (range: 0.30–0.71 Gy/GBq). Comparison to another PRRT dosimetry code (VRAK: Voxelized Registration and Kinetics) showed fair accordance with irtGPUMCD (11.4 ± 6.8 %, range: 3.3–26.2%). These results suggest the possibility to use the irtGPUMCD code in order to personalize administered activity in PRRT. This could allow improving clinical outcomes by maximizing per-cycle tumor doses, without exceeding the tolerable renal dose.« less

Optical and scintillation characteristics of Gd2YAl2Ga3O12:Ce and Lu2YAl2Ga3O12:Ce single crystals

NASA Astrophysics Data System (ADS)

Chewpraditkul, Warut; Sakthong, Ongsa; Pattanaboonmee, Nakarin; Chewpraditkul, Weerapong; Szczesniak, Tomasz; Swiderski, Lukasz; Moszynski, Marek; Kamada, Kei; Yoshikawa, Akira; Nikl, Martin

2017-06-01

The optical and scintillation characteristics of Gd2YAl2Ga3O12:Ce and Lu2YAl2Ga3O12:Ce single crystals are investigated. At 662 keV γ-rays, light yield (LY) of 37,900 ph/MeV and energy resolution of 7.0% obtained for Gd2YAl2Ga3O12:Ce are superior to those of 18,900 ph/MeV and 11.5% obtained for Lu2YAl2Ga3O12:Ce. Scintillation decays are measured using the time-correlated single photon counting technique. A fast component decay time of 45 ns with relative intensity of 88% obtained for Lu2YAl2Ga3O12:Ce is superior to that of 50 ns (65%) for Gd2YAl2Ga3O12:Ce. The linear attenuation coefficient at 662 keV γ-rays is also determined and discussed.

Study of Y and Lu iron garnets using Bethe-Peierls-Weiss method

NASA Astrophysics Data System (ADS)

Goveas, Neena; Mukhopadhyay, G.; Mukhopadhyay, P.

1994-11-01

We study here the magnetic properties of Y- and Lu- Iron Garnets using the Bethe- Peierls-Weiss method modified to suit complex systems like these Garnets. We consider these Garnets as described by Heisenberg Hamiltonian with two sublattices (a,d) and determine the exchange interaction parameters Jad, Jaa and Jdd by matching the exerimental susceptibility curves. We find Jaa and Jdd to be much smaller than those determined by Néel theory, and consistent with those obtained by the study of spin wave spectra; the spin wave dispersion relation constant obtained using these parameters gives good agreement with the experimental values.

Adaptive integral backstepping sliding mode control for opto-electronic tracking system based on modified LuGre friction model

NASA Astrophysics Data System (ADS)

Yue, Fengfa; Li, Xingfei; Chen, Cheng; Tan, Wenbin

2017-12-01

In order to improve the control accuracy and stability of opto-electronic tracking system fixed on reef or airport under friction and external disturbance conditions, adaptive integral backstepping sliding mode control approach with friction compensation is developed to achieve accurate and stable tracking for fast moving target. The nonlinear observer and slide mode controller based on modified LuGre model with friction compensation can effectively reduce the influence of nonlinear friction and disturbance of this servo system. The stability of the closed-loop system is guaranteed by Lyapunov theory. The steady-state error of the system is eliminated by integral action. The adaptive integral backstepping sliding mode controller and its performance are validated by a nonlinear modified LuGre dynamic model of the opto-electronic tracking system in simulation and practical experiments. The experiment results demonstrate that the proposed controller can effectively realise the accuracy and stability control of opto-electronic tracking system.

Structural features of single crystals of LuB{sub 12} upon a transition to the cage-glass phase

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

Bolotina, N. B., E-mail: nb-bolotina@mail.ru; Verin, I. A.; Shitsevalova, N. Yu.

2016-03-15

The unit-cell parameters of dodecaboride LuB{sub 12}, which undergoes a transition to the cage-glass phase, have been determined for the first time in the temperature range of 50–75 K by X-ray diffraction, and the single-crystal structure of this compound is established at 50 K. Nonlinear changes in the unit-cell parameters correspond to anomalies in the physical properties near the glass-transition temperature T* ~ 50–70 K. This compound has cubic symmetry at room temperature, and it is reduced to tetragonal symmetry at lower temperatures. Based on the X-ray diffraction data and relying on the physical properties of the crystals, the structuremore » model, in which a small part (~15%) of Lu atoms are displaced from the 2a sites at the centers of the B{sub 24} cuboctahedra to the 16n sites of sp. gr. I4/mmm, seems preferable.« less

Enhancing luminescence of Lu{sub 2}MoO{sub 6}:Eu{sup 3+} phosphors by doping with Li{sup +} ions for near ultraviolet based solid state lighting

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

Li, Li, E-mail: lilic@cqupt.edu.cn; Shen, Jun; Pan, Yu

Graphical abstract: The emission spectra of Lu{sub 2}MoO{sub 6}:3%Eu{sup 3+}, x%Li{sup +} phosphors under 365 nm excitation. The inset represents emission intensity of 610 nm as a function of Li{sup +} molar concentration. - Highlights: • Lu{sub 2}MoO{sub 6}:3%Eu{sup 3+}, x%Li{sup +} phosphors were synthesized by solid-state reaction method. • All the prepared phosphors can be assigned to its monoclinic phase. • The optimal concentration of Li{sup +} ions is 30mol%. • The luminescent intensity of Lu{sub 2}MoO{sub 6}:Eu{sup 3+} phosphors has been greatly enhanced by codoping Li{sup +} ions. - Abstract: Lu{sub 2}MoO{sub 6}: 3% Eu{sup 3+} co-doped withmore » x% Li{sup +} (x = 0–40 mol) phosphors were synthesized by high-temperature solid-state reaction method. The structure and luminescent properties of these phosphors were investigated. The X-ray diffraction (XRD) results show that all prepared phosphors can be assigned to monoclinic phase and codoping with Li{sup +} ions does not change their crystallographic structure. The excitation and emission spectra show that the samples can be effectively excited by the near ultraviolet light at 365 nm and exhibit strong red emission centered at 610 nm. The experimental results indicate the red luminescent intensity of Lu{sub 2}MoO{sub 6}:Eu{sup 3+} phosphors has been greatly enhanced by codoping with Li{sup +} ions. The enhancement of the luminescent intensity can be the consequence of the modification of the local field symmetry around the Eu{sup 3+} ion, improved crystallization, and the enlarged grain size induced by the Li{sup +} ions.« less

Identification and characterization of cis-acting elements involved in the regulation of ABA- and/or GA-mediated LuPLR1 gene expression and lignan biosynthesis in flax (Linum usitatissimum L.) cell cultures.

PubMed

Corbin, Cyrielle; Renouard, Sullivan; Lopez, Tatiana; Lamblin, Frédéric; Lainé, Eric; Hano, Christophe

2013-03-15

Pinoresinol lariciresinol reductase 1, encoded by the LuPLR1 gene in flax (Linum usitatissimum L.), is responsible for the biosynthesis of (+)-secoisolariciresinol, a cancer chemopreventive phytoestrogenic lignan accumulated in high amount in the hull of flaxseed. Our recent studies have demonstrated a key role of abscisic acid (ABA) in the regulation of LuPLR1 gene expression and thus of the (+)-secoisolariciresinol synthesis during the flax seedcoat development. It is well accepted that gibberellins (GA) and ABA play antagonistic roles in the regulation of numerous developmental processes; therefore it is of interest to clarify their respective effects on lignan biosynthesis. Herein, using flax cell suspension cultures, we demonstrate that LuPLR1 gene expression and (+)-secoisolariciresinol synthesis are up-regulated by ABA and down-regulated by GA. The LuPLR1 gene promoter analysis and mutation experiments allow us to identify and characterize two important cis-acting sequences (ABRE and MYB2) required for these regulations. These results imply that a cross-talk between ABA and GA signaling orchestrated by transcription factors is involved in the regulation of lignan biosynthesis. This is particularly evidenced in the case of the ABRE cis-regulatory sequence of LuPLR1 gene promoter that appears to be a common target sequence of GA and ABA signals. Copyright © 2012 Elsevier GmbH. All rights reserved.

Spatial analysis of deaths from pulmonary tuberculosis in the city of São Luís, Brazil*

PubMed Central

Santos-Neto, Marcelino; Yamamura, Mellina; Garcia, Maria Concebida da Cunha; Popolin, Marcela Paschoal; Silveira, Tatiane Ramos dos Santos; Arcêncio, Ricardo Alexandre

2014-01-01

OBJECTIVE: To characterize deaths from pulmonary tuberculosis, according to sociodemographic and operational variables, in the city of São Luís, Brazil, and to describe their spatial distribution. METHODS: This was an exploratory ecological study based on secondary data from death certificates, obtained from the Brazilian Mortality Database, related to deaths from pulmonary tuberculosis. We included all deaths attributed to pulmonary tuberculosis that occurred in the urban area of São Luís between 2008 and 2012. We performed univariate and bivariate analyses of the sociodemographic and operational variables of the deaths investigated, as well as evaluating the spatial distribution of the events by kernel density estimation. RESULTS: During the study period, there were 193 deaths from pulmonary tuberculosis in São Luís. The median age of the affected individuals was 52 years. Of the 193 individuals who died, 142 (73.60%) were male, 133 (68.91%) were Mulatto, 102 (53.13%) were single, and 64 (33.16%) had completed middle school. There was a significant positive association between not having received medical care prior to death and an autopsy having been performed (p = 0.001). A thematic map by density of points showed that the spatial distribution of those deaths was heterogeneous and that the density was as high as 8.12 deaths/km2. CONCLUSIONS: The sociodemographic and operational characteristics of the deaths from pulmonary tuberculosis evaluated in this study, as well as the identification of priority areas for control and surveillance of the disease, could promote public health policies aimed at reducing health inequities, allowing the optimization of resources, as well as informing decisions regarding the selection of strategies and specific interventions targeting the most vulnerable populations. PMID:25410843

Spatial analysis of deaths from pulmonary tuberculosis in the city of São Luís, Brazil.

PubMed

Santos-Neto, Marcelino; Yamamura, Mellina; Garcia, Maria Concebida da Cunha; Popolin, Marcela Paschoal; Silveira, Tatiane Ramos Dos Santos; Arcêncio, Ricardo Alexandre

2014-10-01

To characterize deaths from pulmonary tuberculosis, according to sociodemographic and operational variables, in the city of São Luís, Brazil, and to describe their spatial distribution. This was an exploratory ecological study based on secondary data from death certificates, obtained from the Brazilian Mortality Database, related to deaths from pulmonary tuberculosis. We included all deaths attributed to pulmonary tuberculosis that occurred in the urban area of São Luís between 2008 and 2012. We performed univariate and bivariate analyses of the sociodemographic and operational variables of the deaths investigated, as well as evaluating the spatial distribution of the events by kernel density estimation. During the study period, there were 193 deaths from pulmonary tuberculosis in São Luís. The median age of the affected individuals was 52 years. Of the 193 individuals who died, 142 (73.60%) were male, 133 (68.91%) were Mulatto, 102 (53.13%) were single, and 64 (33.16%) had completed middle school. There was a significant positive association between not having received medical care prior to death and an autopsy having been performed (p = 0.001). A thematic map by density of points showed that the spatial distribution of those deaths was heterogeneous and that the density was as high as 8.12 deaths/km2. The sociodemographic and operational characteristics of the deaths from pulmonary tuberculosis evaluated in this study, as well as the identification of priority areas for control and surveillance of the disease, could promote public health policies aimed at reducing health inequities, allowing the optimization of resources, as well as informing decisions regarding the selection of strategies and specific interventions targeting the most vulnerable populations.

Manufacturing issues and optical properties of rare-earth (Y, Lu, Sc, Nd) aluminate garnets composite transparent ceramics

NASA Astrophysics Data System (ADS)

Bonnet, Loïck; Boulesteix, Rémy; Maître, Alexandre; Sallé, Christian; Couderc, Vincent; Brenier, Alain

2015-12-01

In this work, a comparative study of reactive sintering and optical properties of three laser composite transparent ceramics doped with neodymium: Nd:YAG/Nd:YS1AG, Nd:YAG/Nd:LuAG and Nd:YS1AG/Nd:LuAG has been achieved. Samples were manufactured thanks to pressureless co-sintering under vacuum of bilayer powder compacts. The reaction sequence from primary oxides to final garnet phases has been investigated. Similar dilatometric behavior was observed during reactive-sintering for each composition. Differential shrinkage can be thus accommodated to some extent. Second, this work has shown that the intermediate zone at composites interface is composed of single-phased garnet solid-solution with continuous evolution from one side to the other. The thickness of the interdiffusion zone was found to be limited to about 100 μm in all cases and appeared to be well described by classical diffusion laws of Fick and Whipple-Le Claire. The analyses of spectroscopic properties of transparent ceramics composites have finally shown that composite ceramics should be suitable to produce dual wavelength emission for terahertz generation.

Identification of Cr valence states in Cr and Nd co-doped Lu3Al5O12 laser ceramics

NASA Astrophysics Data System (ADS)

Zhang, Pande; Jiang, Benxue; Fan, Jintai; Mao, Xiaojian; Zhang, Long

2017-09-01

Cr and Nd co-doped laser ceramics, as the potential gain materials in inertial confinement fusion (ICF), have been widely investigated. And the study on valence states of chromium ions is important. The effects of sintering additives and annealing atmosphere on the valence state of chromium were studied in detail, and the results shown that the Cr valence states were demonstrated to be Cr2+ and Cr3+ ions in HIP-sintered Cr(0.2 at.%), Nd(0.8 at.%): LuAG laser ceramics. And the intensity of the near-infrared absorption band caused by Cr2+ ions was attenuated with the decreasing SiO2 concentration and increasing MgO amount. The near-infrared absorption could be eliminated by annealing in air. And the transformation of valence states of Cr ions in the Cr,Nd:LuAG ceramics were also confirmed by electron paramagnetic resonance and X-ray photoelectron spectroscopy.

Effects of a vegetable extract from Lupinus albus (LU105) on the production of matrix metalloproteinases (MMP1, MMP2, MMP9) and tissue inhibitor of metalloproteinases (TIMP1, TIMP2) by human gingival fibroblasts in culture.

PubMed

Gaultier, F; Foucault-Bertaud, A; Lamy, E; Ejeil, A L; Dridi, S M; Piccardi, N; Piccirilli, A; Msika, P; Godeau, G; Gogly, B

2003-12-01

This study examined the effects of a vegetable extract from Lupinus albus (LU105) on MMPs and TIMPs secreted by human gingival fibroblasts in culture. LU105 was extracted from seeds of L. albus and is freely soluble in water. Gelatin zymography showed that control human gingival fibroblasts maintained in culture for 48 h express pro-MMP2 (progelatinase A) in the culture medium while the active form of MMP2 (gelatinase A), the active form of MMP9 (gelatinase B), and pro-MMP9 (progelatinase B) are not detected. Fibroblasts derived from inflamed gingiva expressed in the culture medium increased amounts of pro-MMP2 (progelatinase A) compared with controls and significant amounts of pro-MMP9 (progelatinase B). LU105 diminished the expression by gingival fibroblasts derived from inflamed tissue of both pro-MMP2 and pro-MMP9. Furthermore LU105 did not modify the amount of TIMP2 expressed in culture by controls or by gingival fibroblasts derived from inflamed tissue. TIMP1 and MMP1 significantly decreased when LU105 was added in the culture media of gingival fibroblasts derived from inflamed tissue compared with control fibroblasts. Thus LU105 seems to offer an opportunity to restore a correct balance between MMP2, MMP9, MMP1, and their natural inhibitors, i.e., TIMP1 and TIMP2 in human inflamed gingiva.

Characteristics of Bremsstrahlung emissions of (177)Lu, (188)Re, and (90)Y for SPECT/CT quantification in radionuclide therapy.

PubMed

Uribe, Carlos F; Esquinas, Pedro L; Gonzalez, Marjorie; Celler, Anna

2016-05-01

Beta particles emitted by radioisotopes used in targeted radionuclide therapies (TRT) create Bremsstrahlung (BRS) which may affect SPECT quantification when imaging these isotopes. The purpose of the current study was to investigate the characteristics of Bremsstrahlung produced in tissue by three β-emitting radioisotopes used in TRT. Monte Carlo simulations of (177)Lu, (188)Re, and (90)Y sources placed in water filled cylinders were performed. BRS yields, mean energies and energy spectra for (a) all photons generated in the decays, (b) photons that were not absorbed and leave the cylinder, and (c) photons detected by the camera were analyzed. Next, the results of simulations were compared with those from experiments performed on a clinical SPECT camera using same acquisition conditions and phantom configurations as in simulations. Simulations reproduced relatively well the shapes of the measured spectra, except for (90)Y which showed an overestimation in the low energy range. Detailed analysis of the results allowed us to suggest best collimators and imaging conditions for each of the investigated isotopes. Finally, our simulations confirmed that the BRS contribution to the energy spectra in quantitative imaging of (177)Lu and (188)Re could be ignored. For (177)Lu and (188)Re, BRS contributes only marginally to the total spectra recorded by the camera. Our analysis shows that MELP and HE collimators are the best for imaging these two isotopes. For (90)Y, HE collimator should be used. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Correlation consistent basis sets for lanthanides: The atoms La–Lu

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

Lu, Qing; Peterson, Kirk A., E-mail: kipeters@wsu.edu

Using the 3rd-order Douglas-Kroll-Hess (DKH3) Hamiltonian, all-electron correlation consistent basis sets of double-, triple-, and quadruple-zeta quality have been developed for the lanthanide elements La through Lu. Basis sets designed for the recovery of valence correlation (defined here as 4f5s5p5d6s), cc-pVnZ-DK3, and outer-core correlation (valence + 4s4p4d), cc-pwCVnZ-DK3, are reported (n = D, T, and Q). Systematic convergence of both Hartree-Fock and correlation energies towards their respective complete basis set (CBS) limits are observed. Benchmark calculations of the first three ionization potentials (IPs) of La through Lu are reported at the DKH3 coupled cluster singles and doubles with perturbative triples,more » CCSD(T), level of theory, including effects of correlation down through the 4s electrons. Spin-orbit coupling is treated at the 2-component HF level. After extrapolation to the CBS limit, the average errors with respect to experiment were just 0.52, 1.14, and 4.24 kcal/mol for the 1st, 2nd, and 3rd IPs, respectively, compared to the average experimental uncertainties of 0.03, 1.78, and 2.65 kcal/mol, respectively. The new basis sets are also used in CCSD(T) benchmark calculations of the equilibrium geometries, atomization energies, and heats of formation for Gd{sub 2}, GdF, and GdF{sub 3}. Except for the equilibrium geometry and harmonic frequency of GdF, which are accurately known from experiment, all other calculated quantities represent significant improvements compared to the existing experimental quantities. With estimated uncertainties of about ±3 kcal/mol, the 0 K atomization energies (298 K heats of formation) are calculated to be (all in kcal/mol): 33.2 (160.1) for Gd{sub 2}, 151.7 (−36.6) for GdF, and 447.1 (−295.2) for GdF{sub 3}.« less

Magnetization dynamics and frustration in the multiferroic double perovskite Lu 2MnCoO 6

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

Zapf, Vivien S.; Ueland, B. G.; Laver, Mark

2016-04-29

Here, we investigate the magnetic ordering and the magnetization dynamics (from kHz to THz time scales) of the double perovskite Lu 2MnCoO 6 using elastic neutron diffraction, muon spin relaxation, and micro-Hall magnetization measurements. This compound is known to be a type II multiferroic with the interesting feature that a ferromagneticlike magnetization hysteresis loop couples to an equally hysteretic electric polarization in the bulk of the material despite a zero-field magnetic ordering of the type ↑↑↓↓ along Co-Mn spin chains. Here we explore the unusual dynamics of this compound and find extremely strong fluctuations, consistent with the axial next-nearest-neighbor Isingmore » (ANNNI) model for frustrated spin chains. We identify three temperature scales in Lu 2MnCoO 6 corresponding to the onset of highly fluctuating long-range order below T N = 50±3 K identified from neutron scattering, the onset of magnetic and electric hysteresis, with change in kHz magnetic and electric dynamics below a 30 K temperature scale, and partial freezing of ~MHz spin fluctuations in the muon spin relaxation data below 12 ± 3 K. Our results provide a framework for understanding the multiferroic behavior of this compound and its hysteresis and dynamics.« less

Temperature dependence of the radiation tolerance of nanocrystalline pyrochlores A 2Ti 2O 7 (A = Gd, Ho and Lu)

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

Wen, J.; Sun, C.; Dholabhai, P. P.

A potentially enhanced radiation resistance of nanocrystalline materials, as a consequence of the high density of interfaces and surfaces, has attracted much attention both to understand the fundamental role of these defect sinks and to develop them for high-radiation environments. Here, irradiation response of nanocrystalline A 2Ti 2O 7 (A = Gd, Ho and Lu) pyrochlore powders with grain sizes of 20–30 nm was investigated by 1-MeV Kr 2+ ion bombardment. In situ transmission electron microscopy (TEM) revealed that the critical amorphization fluence for each nanocrystalline compound at room temperature was greater than that for their coarse-grained counterparts, indicating anmore » enhanced amorphization resistance. The effect of temperature on the irradiation response of one of these compounds, nanocrystalline Lu 2Ti 2O 7, was further examined by performing ion irradiation at an elevated temperature range of 480–600 K. The critical amorphization temperature (T c) was found to be noticeably higher in nanocrystalline Lu 2Ti 2O 7 (610 K) than its coarse-grained counterpart (480 K), revealing that nanocrystalline Lu 2Ti 2O 7 is less resistant to amorphization compared to its coarse-grained phase under high temperatures. We interpret these results with the aid of atomistic simulations. Molecular statics calculations find that cation antisite defects are less energetically costly to form near surfaces than in the bulk, suggesting that the nanocrystalline form of these materials is generally less susceptible to amorphization than coarse-grained counterparts at low temperatures where defect kinetics are negligible. In contrast, at high temperatures, the annealing efficiency of antisite defects by cation interstitials is significantly reduced due to the sink properties of the surfaces in the nanocrystalline pyrochlore, which contributes to the observed higher amorphization temperature in the nano-grained phase than in coarse-grained counterpart. Altogether, these

Temperature dependence of the radiation tolerance of nanocrystalline pyrochlores A 2Ti 2O 7 (A = Gd, Ho and Lu)

DOE PAGES

Wen, J.; Sun, C.; Dholabhai, P. P.; ...

2016-03-21

A potentially enhanced radiation resistance of nanocrystalline materials, as a consequence of the high density of interfaces and surfaces, has attracted much attention both to understand the fundamental role of these defect sinks and to develop them for high-radiation environments. Here, irradiation response of nanocrystalline A 2Ti 2O 7 (A = Gd, Ho and Lu) pyrochlore powders with grain sizes of 20–30 nm was investigated by 1-MeV Kr 2+ ion bombardment. In situ transmission electron microscopy (TEM) revealed that the critical amorphization fluence for each nanocrystalline compound at room temperature was greater than that for their coarse-grained counterparts, indicating anmore » enhanced amorphization resistance. The effect of temperature on the irradiation response of one of these compounds, nanocrystalline Lu 2Ti 2O 7, was further examined by performing ion irradiation at an elevated temperature range of 480–600 K. The critical amorphization temperature (T c) was found to be noticeably higher in nanocrystalline Lu 2Ti 2O 7 (610 K) than its coarse-grained counterpart (480 K), revealing that nanocrystalline Lu 2Ti 2O 7 is less resistant to amorphization compared to its coarse-grained phase under high temperatures. We interpret these results with the aid of atomistic simulations. Molecular statics calculations find that cation antisite defects are less energetically costly to form near surfaces than in the bulk, suggesting that the nanocrystalline form of these materials is generally less susceptible to amorphization than coarse-grained counterparts at low temperatures where defect kinetics are negligible. In contrast, at high temperatures, the annealing efficiency of antisite defects by cation interstitials is significantly reduced due to the sink properties of the surfaces in the nanocrystalline pyrochlore, which contributes to the observed higher amorphization temperature in the nano-grained phase than in coarse-grained counterpart. Altogether, these

Cohort study of somatostatin-based radiopeptide therapy with [(90)Y-DOTA]-TOC versus [(90)Y-DOTA]-TOC plus [(177)Lu-DOTA]-TOC in neuroendocrine cancers.

PubMed

Villard, Linda; Romer, Anna; Marincek, Nicolas; Brunner, Philippe; Koller, Michael T; Schindler, Christian; Ng, Quinn K T; Mäcke, Helmut R; Müller-Brand, Jan; Rochlitz, Christoph; Briel, Matthias; Walter, Martin A

2012-04-01

Radiopeptide therapy is commonly performed with a single radioisotope. We aimed to compare the effectiveness of somatostatin-based radiopeptide therapy with a single versus a combination of radioisotopes. In a cohort study, patients with metastasized neuroendocrine cancer were treated with repeated cycles of (90)yttrium-labeled tetraazacyclododecane-tetraacetic acid modified Tyr-octreotide ([(90)Y-DOTA]-TOC) or with cycles alternating between [(90)Y-DOTA]-TOC and (177)lutetium-labeled DOTA-TOC ([(177)Lu-DOTA]-TOC) until tumor progression or permanent toxicity. Multivariable Cox regression and competing risk regression were used to study predictors of survival and renal toxicity in patients completing three or more treatment cycles. A total of 486 patients completed three or more treatment cycles; 237 patients received [(90)Y-DOTA]-TOC and 249 patients received [(90)Y-DOTA]-TOC + [(177)Lu-DOTA]-TOC. Patients receiving [(90)Y-DOTA]-TOC + [(177)Lu-DOTA]-TOC had a significantly longer survival than patients receiving [(90)Y-DOTA]-TOC alone (5.51 v 3.96 years; hazard ratio, 0.64; 95% CI, 0.47 to 0.88; P = .006). The rates of severe hematologic toxicities (6.3% v 4.4%; P = .25) and severe renal toxicity (8.9% v 11.2%; P = .47) were comparable in both groups. [(90)Y-DOTA]-TOC + [(177)Lu-DOTA]-TOC was associated with improved overall survival compared with [(90)Y-DOTA]-TOC alone in patients completing three or more cycles of treatment. Contrary to the current practice in radiopeptide therapy, our results suggest an advantage of using a combination of radioisotopes.

Evaluation of (68)Ga- and (177)Lu-DOTA-PEG4-LLP2A for VLA-4-Targeted PET Imaging and Treatment of Metastatic Melanoma.

PubMed

Beaino, Wissam; Nedrow, Jessie R; Anderson, Carolyn J

2015-06-01

Malignant melanoma is a highly aggressive cancer, and the incidence of this disease is increasing worldwide at an alarming rate. Despite advances in the treatment of melanoma, patients with metastatic disease still have a poor prognosis and low survival rate. New strategies, including targeted radiotherapy, would provide options for patients who become resistant to therapies such as BRAF inhibitors. Very late antigen-4 (VLA-4) is expressed on melanoma tumor cells in higher levels in more aggressive and metastatic disease and may provide an ideal target for drug delivery and targeted radiotherapy. In this study, we evaluated (177)Lu- and (68)Ga-labeled DOTA-PEG4-LLP2A as a VLA-4-targeted radiotherapeutic with a companion PET agent for diagnosis and monitoring metastatic melanoma treatment. DOTA-PEG4-LLP2A was synthesized by solid-phase synthesis. The affinity of (177)Lu- and (68)Ga-labeled DOTA-PEG4-LLP2A to VLA-4 was determined in B16F10 melanoma cells by saturation binding and competitive binding assays, respectively. Biodistribution of the LLP2A conjugates was determined in C57BL/6 mice bearing B16F10 subcutaneous tumors, while PET/CT imaging was performed in subcutaneous and metastatic models. (177)Lu-DOTA-PEG4-LLP2A showed high affinity to VLA-4 with a Kd of 4.1 ± 1.5 nM and demonstrated significant accumulation in the B16F10 melanoma tumor after 4 h (31.5 ± 7.8%ID/g). The tumor/blood ratio of (177)Lu-DOTA-PEG4-LLP2A was highest at 24 h (185 ± 26). PET imaging of metastatic melanoma with (68)Ga-DOTA-PEG4-LLP2A showed high uptake in sites of metastases and correlated with bioluminescence imaging of the tumors. These data demonstrate that (177)Lu-DOTA-PEG4-LLP2A has potential as a targeted therapeutic for treating melanoma as well as other VLA-4-expressing tumors. In addition, (68)Ga-DOTA-PEG4-LLP2A is a readily translatable companion PET tracer for imaging of metastatic melanoma.

One-step synthesis of NaLu80-xGdxF4:Yb183+/Er23+(Tm3+) upconversion nanoparticles for in vitro cell imaging.

PubMed

Gerelkhuu, Zayakhuu; Huy, Bui The; Sharipov, Mirkomil; Jung, Dasom; Phan, The-Long; Conte, Eric D; Lee, Yong-Ill

2018-05-01

Upconversion nanoparticles (UCNPs) possess a unique type of photoluminescence (PL) in which lower-energy excitation is converted into higher-energy emission via multi-photon absorption processes. In this work, we have used a facile one-step hydrothermal method promoted water solubility to synthesis NaLuGdF 4 :Yb 3+ /Er 3+ (Tm 3+ ) UCNPs coated with malonic acid (MA). Scanning electron microscopy images and X-ray diffraction patterns reveal sphere-shaped UCNPs with an average size of ~80nm crystallized in the cubic NaLuF 4 structure. The characteristic vibrations of cubic UCNPs have been taken into account by using Fourier-transform infrared spectroscopy. Based on PL studies, we have determined an optimal concentration of Gd 3+ doping. The dependence of upconversion PL intensity on Gd 3+ concentration is discussed via the results of magnetization measurements, which is related to the coupling/uncoupling of Gd 3+ ions. Particularly, our study reveals that carboxyl-functionalized NaLuGdF 4 :Yb 3+ /Er 3+ (Tm 3+ ) UCNPs have a relatively high cell viability with HeLa cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Syntheses, structures, and vibrational spectroscopy of the two-dimensional iodates Ln(IO{sub 3}){sub 3} and Ln(IO{sub 3}){sub 3}(H{sub 2}O) (Ln =Yb, Lu)

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

Assefa, Zerihun; Ling Jie; Haire, Richard G.

2006-12-15

The reaction of Lu{sup 3+} or Yb{sup 3+} and H{sub 5}IO{sub 6} in aqueous media at 180 {sup o}C leads to the formation of Yb(IO{sub 3}){sub 3}(H{sub 2}O) or Lu(IO{sub 3}){sub 3}(H{sub 2}O), respectively, while the reaction of Yb metal with H{sub 5}IO{sub 6} under similar reaction conditions gives rise to the anhydrous iodate, Yb(IO{sub 3}){sub 3}. Under supercritical conditions Lu{sup 3+} reacts with HIO{sub 3} and KIO{sub 4} to yield the isostructural Lu(IO{sub 3}){sub 3}. The structures have been determined by single-crystal X-ray diffraction. Crystallographic data are (MoK{alpha}, {lambda}=0.71073 A): Yb(IO{sub 3}){sub 3}, monoclinic, space group P2{sub 1}/n, a=8.6664(9)more » A, b=5.9904(6) A, c=14.8826(15) A, {beta}=96.931(2){sup o}, V=766.99(13), Z=4, R(F)=4.23% for 114 parameters with 1880 reflections with I>2{sigma}(I); Lu(IO{sub 3}){sub 3}, monoclinic, space group P2{sub 1}/n, a=8.6410(9), b=5.9961(6), c=14.8782(16) A, {beta}=97.028(2){sup o}, V=765.08(14), Z=4, R(F)=2.65% for 119 parameters with 1756 reflections with I>2{sigma}(I); Yb(IO{sub 3}){sub 3}(H{sub 2}O), monoclinic, space group C2/c, a=27.2476(15), b=5.6296(3), c=12.0157(7) A, {beta}=98.636(1){sup o}, V=1822.2(2), Z=8, R(F)=1.51% for 128 parameters with 2250 reflections with I>2{sigma}(I); Lu(IO{sub 3}){sub 3}(H{sub 2}O), monoclinic, space group C2/c, a=27.258(4), b=5.6251(7), c=12.0006(16) A, {beta}=98.704(2){sup o}, V=1818.8(4), Z=8, R(F)=1.98% for 128 parameters with 2242 reflections with I>2{sigma}(I). The f elements in all of the compounds are found in seven-coordinate environments and bridged with monodentate, bidentate, or tridentate iodate anions. Both Lu(IO{sub 3}){sub 3}(H and Yb(IO{sub 3}){sub 3}(H{sub 2}O) display distinctively different vibrational profiles from their respective anhydrous analogs. Hence, the Raman profile can be used as a complementary diagnostic tool to discern the different structural motifs of the compounds. - Graphical abstract: Four new metal iodates, Yb

A comparative investigation of Lu2SiO5:Ce and Gd2O2S:Eu powder scintillators for use in x-ray mammography detectors

NASA Astrophysics Data System (ADS)

Michail, C. M.; Fountos, G. P.; David, S. L.; Valais, I. G.; Toutountzis, A. E.; Kalyvas, N. E.; Kandarakis, I. S.; Panayiotakis, G. S.

2009-10-01

The dominant powder scintillator in most medical imaging modalities for decades has been Gd2O2S:Tb due to the very good intrinsic properties and overall efficiency. Apart from Gd2O2S:Tb, there are alternative powder phosphor scintillators such as Lu2SiO5:Ce and Gd2O2S:Eu that have been suggested for use in various medical imaging modalities. Gd2O2S:Eu emits red light and can be combined mainly with digital mammography detectors such as CCDs. Lu2SiO5:Ce emits blue light and can be combined with blue sensitivity films, photocathodes and some photodiodes. For the purposes of the present study, two scintillating screens, one from Lu2SiO5:Ce and the other from Gd2O2S:Eu powders, were prepared using the method of sedimentation. The screen coating thicknesses were 25.0 and 33.1 mg cm-2 respectively. The screens were investigated by evaluating the following parameters: the output signal, the modulation transfer function, the noise equivalent passband, the informational efficiency, the quantum detection efficiency and the zero-frequency detective quantum efficiency. Furthermore, the spectral compatibility of those materials with various optical detectors was determined. Results were compared to published data for the commercially employed 'Kodak Min-R film-screen system', based on a 31.7 mg cm-2 thick Gd2O2S:Tb phosphor. For Gd2O2S:Eu, MTF data were found comparable to those of Gd2O2S:Tb, while the MTF of Lu2SiO5:Ce was even higher resulting in better spatial resolution and image sharpness properties. On the other hand, Gd2O2S:Eu was found to exhibit higher output signal and zero-frequency detective quantum efficiency than Lu2SiO5:Ce.

All-solid-state continuous-wave frequency doubling Nd:LuVO4/LBO laser with 2.17 W output power at 543 nm

NASA Astrophysics Data System (ADS)

Li, B.; Zhao, L.; Zhang, Y. B.; Zheng, Q.; Zhao, Y.; Yao, Y.

2013-03-01

Efficient and compact green-yellow laser output at 543 nm is generated by intracavity frequency doubling of a CW diode-pumped Nd:LuVO4 laser at 1086 nm under the condition of suppressing the higher gain transition near 1064 nm. With 16 W of diode pump power and the frequency-doubling crystal LBO, as high as 2.17 W of CW output power at 543 nm is achieved, corresponding to an optical-to-optical conversion efficiency of 13.6% and the output power stability over 8 hours is better than 2.86%. To the best of our knowledge, this is the highest watt-level laser at 543 nm generated by intracavity frequency doubling of a diode pumped Nd:LuVO4 laser at 1086 nm.

Dielectric and impedance properties of NiFe1.95R0.05O4 (R = Y, Yb and Lu)

NASA Astrophysics Data System (ADS)

Ugendar, Kodam; Kumar, Hanuma; Markaneyulu, G.; Rani, G. Neeraja

2018-04-01

The dielectric and impedance spectroscopic properties of NiFe1.95R0.05O4 (R = Y, Yb and Lu) were investigated. The materials were prepared by solid state reaction and crystallized in the cubic inverse spinel phase with a very small amount additional phase of RFeO3 (R = Y, Yb and Lu) as secondary phase. The scanning electron micrograph images clearly show grains (˜2μm) which are separated by thin grain boundaries. The presences of all elements were confirmed by the energy dispersive X-ray elemental mapping. The frequency variation of ɛ' shows the dispersion, following the Koop's phenomenological theory, which considers the dielectric structure as an inhomogeneous medium of two-layers of the Maxwell-Wagner type. Impedance spectroscopic analysis indicates the different relaxation mechanisms, which corresponds to bulk grain and grain-boundaries. Their contributions to the electrical conductivity and capacitance of these materials were discussed in detailed.

Radioluminescence studies of colloidal oleate-capped β-Na(Gd,Lu)F4:Ln3+ nanoparticles (Ln = Ce, Eu, Tb).

PubMed

Cooper, Daniel R; Capobianco, John A; Seuntjens, Jan

2018-04-26

We report on the synthesis, characterization, and radioluminescence quantification of several new varieties of nanoparticles with the general composition β-NaLnF4, incorporating known luminescent activator/sensitizer pairs. Using Monte Carlo modeling to complement luminescence measurements, we have calculated the radioluminescence yields and intrinsic conversion efficiencies of colloidally-dispersed nanoparticles by comparison to an organic liquid scintillator. While five of the compositions had low to modest radioluminescence yields relative to bulk materials, colloidal β-Na(Lu0.65Gd0.2Tb0.15)F4 displayed a strong output of 39 460 photons per MeV absorbed, comparable to some of the best non-hygroscopic bulk crystal scintillators and X-ray phosphors such as Gd2O2S:Tb. Measurements of β-Na(Lu0.65Gd0.2Tb0.15)F4 powder samples revealed persistent luminescence as well as stable charge trapping, warranting further investigation.

Improved LabPET Detectors Using Lu1.8Gd0.2SiO5:Ce (LGSO) Scintillator Blocks

NASA Astrophysics Data System (ADS)

Bergeron, Mélanie; Pepin, Catherine M.; Cadorette, Jules; Loignon-Houle, Francis; Fontaine, Réjean; Lecomte, Roger

2015-02-01

The scintillator is one of the key building blocks that critically determine the physical performance of PET detectors. The quest for scintillation crystals with improved characteristics has been crucial in designing scanners with superior imaging performance. Recently, it was shown that the decay time constant of high lutetium content Lu1.8Gd0.2SiO5: Ce (LGSO) scintillators can be adjusted by varying the cerium concentration from 0.025 mol% to 0.75 mol%, thus providing interesting characteristics for phoswich detectors. The high light output (90%-120% NaI) and the improved spectral match of these scintillators with avalanche photodiode (APD) readout promise superior energy and timing resolutions. Moreover, their improved mechanical properties, as compared to conventional LGSO ( Lu0.4Gd1.6SiO5: Ce), make block array manufacturing readily feasible. To verify these assumptions, new phoswich block arrays made of LGSO-90%Lu with low and high mol% Ce concentrations were fabricated and assembled into modules dedicated to the LabPET scanner. Typical crystal decay time constants were 31 ns and 47 ns, respectively. Phoswich crystal identification performed using a digital pulse shape discrimination algorithm yielded an average 8% error. At 511 keV, an energy resolution of 17-21% was obtained, while coincidence timing resolution between 4.6 ns and 5.2 ns was achieved. The characteristics of this new LGSO-based phoswich detector module are expected to improve the LabPET scanner performance. The higher stopping power would increase the detection efficiency. The better timing resolution would also allow the use of a narrower coincidence window, thus minimizing the random event rate. Altogether, these two improvements will significantly enhance the noise equivalent count rate performance of an all LGSO-based LabPET scanner.

Magnetic properties of RFe2Zn20 and RCo2Zn20 (R=Y,Nd,Sm,Gd-Lu)

NASA Astrophysics Data System (ADS)

Jia, Shuang; Ni, Ni; Bud'Ko, S. L.; Canfield, P. C.

2009-09-01

Magnetization, resistivity, and specific heat measurements were performed on solution-grown single crystals of RFe2Zn20 and RCo2Zn20 (R=Y,Nd,Sm,Gd-Lu) . Whereas LuCo2Zn20 and YCo2Zn20 manifest unremarkable metallic behavior, LuFe2Zn20 and YFe2Zn20 display behaviors such as characteristic of nearly ferromagnetic Fermi liquids. When the well-defined 4f local moments (Gd3+-Tm3+) are embedded into this strongly polarizable host, they manifest enhanced ferromagnetic ordering and the values of TC for RFe2Zn20 (R=Gd-Tm) scale with the de Gennes factor. In addition, data on the RFe2Zn20 compounds indicate a small crystal electric field (CEF) effect compared with the interaction energy scale. On the other hand, the local moment bearing members of RCo2Zn20 (R=Nd,Sm,Gd-Tm) manifest weak magnetic interactions and the magnetic properties for R=Dy-Tm members are strongly influenced by the CEF effect on the R ions. The magnetic anisotropy and specific heat data for the Co series were used to determine the CEF coefficient of R ion with its cubic point symmetry. These CEF coefficients, determined for the Co series, are consistent with the magnetic anisotropy and specific heat data for the Fe series, which indicates similar CEF effects for the Fe and Co series. Such analysis, combined with specific heat and resistivity data, indicates that for R=Tb-Ho , the CEF splitting scale is smaller than their TC values, whereas for ErFe2Zn20 and TmFe2Zn20 the 4f electrons lose part of their full Hund’s rule ground state degeneracy above TC . YbFe2Zn20 and YbCo2Zn20 manifest typical but distinct heavy fermion behaviors associated with different Kondo temperatures.

Ce(3+) /Tb(3+) non-/single-/co-doped K-Lu-F materials: synthesis, optical properties, and energy transfer.

PubMed

Cao, Chunyan; Xie, An; Noh, Hyeon Mi; Jeong, Jung Hyun

2016-08-01

Using a hydrothermal method, Ce(3+) /Tb(3+) non-/single-/co-doped K-Lu-F materials have been synthesized. The X-ray diffraction (XRD) results suggest that the Ce(3+) and/or Tb(3+) doping had great effects on the crystalline phases of the final samples. The field emission scanning electron microscopy (FE-SEM) images indicated that the samples were in hexagonal disk or polyhedron morphologies in addition to some nanoparticles, which also indicated that the doping also had great effects on the sizes and the morphologies of the samples. The energy-dispersive spectroscopy (EDS) patterns illustrated the constituents of different samples. The enhanced emissions of Tb(3+) were observed in the Ce(3+) /Tb(3+) co-doped K-Lu-F materials. The energy transfer (ET) efficiency ηT were calculated based on the fluorescence yield. The ET mechanism from Ce(3+) to Tb(3+) was confirmed to be the dipole-quadrupole interaction inferred from the theoretical analysis and the experimental data. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Diode pumped passively Q-switched Nd:LuAG laser at 1442.6 nm

NASA Astrophysics Data System (ADS)

Guan, Chen; Liu, Zhaojun; Cong, Zhenhua; Liu, Yang; Xu, Xiaodong; Xu, Jun; Huang, Qingjie; Rao, Han; Chen, Xia; Zhang, Yanmin; Wu, Qianwen; Bai, Fen; Zhang, Sasa

2017-02-01

A diode-end-pumped passively Q-switched Nd:LuAG laser at 1442.6 nm was demonstrated with a V3+:YAG crystal as the saturable absorber. Under continuous-wave (CW) operation, the maximum output power of 1.83 W was obtained with an absorbed pumping power of 11.1 W. The corresponding optical-to-optical conversion efficiency was 16.5%. Under Q-switched operation, the maximum average output power of 424 mW was obtained at the same pumping power. The pulse duration and pulse repetition rate were 72 ns and 17.4 kHz, respectively.

The LuWD40-1 gene encoding WD repeat protein regulates growth and pollen viability in flax (Linum Usitatissimum L.).

PubMed

Kumar, Santosh; Jordan, Mark C; Datla, Raju; Cloutier, Sylvie

2013-01-01

As a crop, flax holds significant commercial value for its omega-3 rich oilseeds and stem fibres. Canada is the largest producer of linseed but there exists scope for significant yield improvements. Implementation of mechanisms such as male sterility can permit the development of hybrids to assist in achieving this goal. Temperature sensitive male sterility has been reported in flax but the leakiness of this system in field conditions limits the production of quality hybrid seeds. Here, we characterized a 2,588 bp transcript differentially expressed in male sterile lines of flax. The twelve intron gene predicted to encode a 368 amino acid protein has five WD40 repeats which, in silico, form a propeller structure with putative nucleic acid and histone binding capabilities. The LuWD40-1 protein localized to the nucleus and its expression increased during the transition and continued through the vegetative stages (seed, etiolated seedling, stem) while the transcript levels declined during reproductive development (ovary, anthers) and embryonic morphogenesis of male fertile plants. Knockout lines for LuWD40-1 in flax failed to develop shoots while overexpression lines showed delayed growth phenotype and were male sterile. The non-viable flowers failed to open and the pollen grains from these flowers were empty. Three independent transgenic lines overexpressing the LuWD40-1 gene had ∼80% non-viable pollen, reduced branching, delayed flowering and maturity compared to male fertile genotypes. The present study provides new insights into a male sterility mechanism present in flax.

Vibrational and elastic properties of Ln2Sn2O7 (Ln = La, Sm, Gd, Dy, Ho, Er, Yb, or Lu)

NASA Astrophysics Data System (ADS)

Akbudak, S.; Kushwaha, A. K.

2018-04-01

In this study, an eight-parameter bond-bending force constant model was used to calculate the zone center phonon frequencies, elastic constants, and related properties of the stannate compounds Ln2Sn2O7 (Ln = La, Sm, Gd, Dy, Ho, Er, Yb, or Lu) with a pyrochlore structure. We found that the Snsbnd O bond strengths dominate the Ln-O and Osbnd O bonds. We also found that all of the materials are ductile and anisotropic in nature. The anisotropic nature of the compounds increases in the order of: La2Sn2O7 < Sm2Sn2O7 < Gd2Sn2O7 < Dy2Sn2O7 < Ho2Sn2O7 < Er2Sn2O7 < Yb2Sn2O7 < Lu2Sn2O7.

Low-temperature structure transition in hexagonal LuFeO3

NASA Astrophysics Data System (ADS)

Xu, Xiaoshan; Wang, Wenbin; Wang, Xiao; Zhu, Leyi; Kim, Jong-Woo; Ryan, Phillip; Keavney, David; Ward, Thomas; Shen, Jian; Cheng, Xuemei

2014-03-01

The structural change of h-LuFeO3 films at low temperature has been studied using x-ray diffraction and x-ray absorption experiments. The results are analyzed using the displacements of three phonon modes that are related to the P63/mmc to P63cm structural transition. The data indicate that the in-plane motion of the Fe and apex oxygen are responsible for the observed anomaly in both x-ray absorption and diffraction experiments. This subtle structural transition may be an origin of the low temperature magnetic phase transition at TR=130 K. Research supported by US DOE, Office of Basic Energy Sciences, Materials Science and Engineering Division. Work at BMC is supported by NSF Career award (DMR 1053854). Work at ANL is supported by US-DOE, Office of Science, BES (No. DE-AC02-06CH11357).

Continuous wave channel waveguide lasers in Nd:LuVO4 fabricated by direct femtosecond laser writing.

PubMed

Ren, Yingying; Dong, Ningning; Macdonald, John; Chen, Feng; Zhang, Huaijin; Kar, Ajoy K

2012-01-30

Buried channel waveguides in Nd:LuVO<4 were fabricated by femtosecond laser writing with the double-line technique. The photoluminescence properties of the bulk materials were found to be well preserved within the waveguide core region. Continuous-wave laser oscillation at 1066.4 nm was observed from the waveguide under ~809 nm optical excitation, with the absorbed pump power at threshold and laser slope efficiency of 98 mW and 14%, respectively.

WE-H-207A-01: Computational Evaluation of High-Resolution 18F Positron Imaging Using Radioluminescence Microscopy with Lu2O3: Eu Thin-Film Scintillator

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

Wang, Q; Sengupta, D; Pratx, G

2016-06-15

Purpose: Radioluminescence microscopy, an emerging and powerful tool for high resolution beta imaging, has been applied to molecular imaging of cellular metabolism to understand tumor biology. A novel thin-film (10 µm thickness) scintillator made of Lu{sub 2}O{sub 3}: Eu has been developed to enhance the system performance. However the advances of radioluminescence imaging with Lu{sub 2}O{sub 3}scintillator compared with that using conventional scintillator have not been explored theoretically to date. To validate the advantages of the thin-film scintillator, this study uses a novel computational simulation framework to evaluate the performance of radioluminescence microscopy using both conventional and thin-film scintillators. Methods:more » Numerical models for different stages of positron imaging are established. Positron from {sup 18}F passing through the scintillator and its neighbor structures are modeled by Monte-Carlo simulation using Geant4. The propagation and focus of photons by the microscope are modeled by convolution with a depth-varying point spread function generated by the Gibson-Lanni model. Photons focused on the detector plane are then captured and converted into electronic signals by an electron multiplication (EM) CCD camera, which is described by a photosensor model considering various noises and charge amplification. Results: The performance metrics of radioluminescence imaging with a thin-film Lu{sub 2}O{sub 3} and conventional CdWO{sub 4} scintillator are compared, including spatial resolution, sensitivity, positron track area and intensity. The spatial resolution of Lu{sub 2}O{sub 3} system can achieve 10 µm maximally, a 12 µm enhancement from that obtained from CdWO{sub 4} system. Meanwhile, the system with Lu{sub 2}O{sub 3} scintillator can provide a higher mean sensitivity: 40% compared with that (21.5%) obtained from CdWO{sub 4} system. Moreover, the simulation results are in good agreement with previous experimental measurements

Magnetic and superconducting phase diagrams of single-crystal Er0.8R0.2Ni2B2C (R=Tb,Lu) and ErNi1.9Co0.1B2C: Identification of pair-breaking mechanisms

NASA Astrophysics Data System (ADS)

Takeya, H.; El Massalami, M.

2004-01-01

We investigated the magnetism, superconductivity and their interplay in single crystals Er0.8R0.2Ni2B2C (R=Tb,Lu) and ErNi1.9Co0.1B2C. In contrast to Co substitution, R substitutions induce considerable modifications in the magnetism of Er sublattice: e.g., Tb (Lu) substitution enhances (reduces) TN and critical fields. Both R substitutions introduce size effects and pinning centers; the former modifies the magnon specific heat while the latter hinders the formation of a weak ferromagnetism. The superconductivity, on the other hand, is strongly (weakly) influenced by Tb and Co (Lu) substitution. Taking LuNi2B2C as a nonmagnetic superconducting limit, we analyzed their superconductivities, as well as that of ErNi2B2C, in terms of multiple pair breaking theory on dirty superconductors. Based on this analysis, many of their superconducting features can be explained: The breakdown of de Gennes scaling is due to the presence of multiple pair breakers, the anisotropy of Hc2(T) is related to the magnetic anisotropy, the absence of a structure in Hc2(T) at TN of Lu substitution (TNLu substitution, the strength of magnon mediated pair breaking process(es) is substantially reduced.

The low-energy β(-) and electron emitter (161)Tb as an alternative to (177)Lu for targeted radionuclide therapy.

PubMed

Lehenberger, Silvia; Barkhausen, Christoph; Cohrs, Susan; Fischer, Eliane; Grünberg, Jürgen; Hohn, Alexander; Köster, Ulli; Schibli, Roger; Türler, Andreas; Zhernosekov, Konstantin

2011-08-01

The low-energy β(-) emitter (161)Tb is very similar to (177)Lu with respect to half-life, beta energy and chemical properties. However, (161)Tb also emits a significant amount of conversion and Auger electrons. Greater therapeutic effect can therefore be expected in comparison to (177)Lu. It also emits low-energy photons that are useful for gamma camera imaging. The (160)Gd(n,γ)(161)Gd→(161)Tb production route was used to produce (161)Tb by neutron irradiation of massive (160)Gd targets (up to 40 mg) in nuclear reactors. A semiautomated procedure based on cation exchange chromatography was developed and applied to isolate no carrier added (n.c.a.) (161)Tb from the bulk of the (160)Gd target and from its stable decay product (161)Dy. (161)Tb was used for radiolabeling DOTA-Tyr3-octreotate; the radiolabeling profile was compared to the commercially available n.c.a. (177)Lu. A (161)Tb Derenzo phantom was imaged using a small-animal single-photon emission computed tomography camera. Up to 15 GBq of (161)Tb was produced by long-term irradiation of Gd targets. Using a cation exchange resin, we obtained 80%-90% of the available (161)Tb with high specific activity, radionuclide and chemical purity and in quantities sufficient for therapeutic applications. The (161)Tb obtained was of the quality required to prepare (161)Tb-DOTA-Tyr3-octreotate. We were able to produce (161)Tb in n.c.a. form by irradiating highly enriched (160)Gd targets; it can be obtained in the quantity and quality required for the preparation of (161)Tb-labeled therapeutic agents. Copyright © 2011 Elsevier Inc. All rights reserved.

Magnetic order and magnetoelectric properties of R2CoMn O6 perovskites (R =Ho , Tm, Yb, and Lu)

NASA Astrophysics Data System (ADS)

Blasco, J.; García-Muñoz, J. L.; García, J.; Subías, G.; Stankiewicz, J.; Rodríguez-Velamazán, J. A.; Ritter, C.

2017-07-01

We present a detailed study on the magnetic structure and magnetoelectric properties of several double perovskites R2CoMn O6 (R =Ho , Tm, Yb, and Lu). All of these samples show an almost perfect (˜94 %) ordering of C o2 + and M n4 + cations in the unit cell. Our research reveals that the magnetic ground state strongly depends on the R size. For samples with larger R (Ho and Tm), the ground state is formed by a ferromagnetic order (F type) of C o2 + and M n4 + moments, while R either remains mainly disordered (Ho) or is coupled antiferromagnetically (Tm) to the Co/Mn sublattice. For samples with smaller R (Yb or Lu), competitive interactions lead to the formation of an E -type arrangement for the C o2 + and M n4 + moments with a large amount of extended defects such as stacking faults. The Y b3 + is partly ordered at very low temperature. The latter samples undergo a metamagnetic transition from the E into the F type, which is coupled to a negative magnetodielectric effect. Actually, the real part of dielectric permittivity shows an anomaly at the magnetic transition for the samples exhibiting an E -type order. This anomaly is absent in samples with F -type order, and, accordingly, it vanishes coupled to the metamagnetic transition for R =Yb or Lu samples. At room temperature, the huge values of the dielectric constant reveal the presence of Maxwell-Wagner depletion layers. Pyroelectric measurements reveal a high polarization at low temperature, but the onset of pyroelectric current is neither correlated to the kind of magnetic ordering nor to the magnetic transition. Our study identified the pyroelectric current as thermally stimulated depolarization current and electric-field polarization curves show a linear behavior at low temperature. Therefore, no clear ferroelectric transition occurs in these compounds.

44Sc-PSMA-617 for radiotheragnostics in tandem with 177Lu-PSMA-617-preclinical investigations in comparison with 68Ga-PSMA-11 and 68Ga-PSMA-617.

PubMed

Umbricht, Christoph A; Benešová, Martina; Schmid, Raffaella M; Türler, Andreas; Schibli, Roger; van der Meulen, Nicholas P; Müller, Cristina

2017-12-01

The targeting of the prostate-specific membrane antigen (PSMA) is of particular interest for radiotheragnostic purposes of prostate cancer. Radiolabeled PSMA-617, a 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA)-functionalized PSMA ligand, revealed favorable kinetics with high tumor uptake, enabling its successful application for PET imaging ( 68 Ga) and radionuclide therapy ( 177 Lu) in the clinics. In this study, PSMA-617 was labeled with cyclotron-produced 44 Sc (T 1/2  = 4.04 h) and investigated preclinically for its use as a diagnostic match to 177 Lu-PSMA-617. 44 Sc was produced at the research cyclotron at PSI by irradiation of enriched 44 Ca targets, followed by chromatographic separation. 44 Sc-PSMA-617 was prepared under standard labeling conditions at elevated temperature resulting in a radiochemical purity of >97% at a specific activity of up to 10 MBq/nmol. 44 Sc-PSMA-617 was evaluated in vitro and compared to the 177 Lu- and 68 Ga-labeled match, as well as 68 Ga-PSMA-11 using PSMA-positive PC-3 PIP and PSMA-negative PC-3 flu prostate cancer cells. In these experiments it revealed similar in vitro properties to that of 177 Lu- and 68 Ga-labeled PSMA-617. Moreover, 44 Sc-PSMA-617 bound specifically to PSMA-expressing PC-3 PIP tumor cells, while unspecific binding to PC-3 flu cells was not observed. The radioligands were investigated with regard to their in vivo properties in PC-3 PIP/flu tumor-bearing mice. 44 Sc-PSMA-617 showed high tumor uptake and a fast renal excretion. The overall tissue distribution of 44 Sc-PSMA-617 resembled that of 177 Lu-PSMA-617 most closely, while the 68 Ga-labeled ligands, in particular 68 Ga-PSMA-11, showed different distribution kinetics. 44 Sc-PSMA-617 enabled distinct visualization of PC-3 PIP tumor xenografts shortly after injection, with increasing tumor-to-background contrast over time while unspecific uptake in the PC-3 flu tumors was not observed. The in vitro characteristics and in vivo

An analysis of supersonic flows with low-Reynolds number compressible two-equation turbulence models using LU finite volume implicit numerical techniques

NASA Technical Reports Server (NTRS)

Lee, J.

1994-01-01

A generalized flow solver using an implicit Lower-upper (LU) diagonal decomposition based numerical technique has been coupled with three low-Reynolds number kappa-epsilon models for analysis of problems with engineering applications. The feasibility of using the LU technique to obtain efficient solutions to supersonic problems using the kappa-epsilon model has been demonstrated. The flow solver is then used to explore limitations and convergence characteristics of several popular two equation turbulence models. Several changes to the LU solver have been made to improve the efficiency of turbulent flow predictions. In general, the low-Reynolds number kappa-epsilon models are easier to implement than the models with wall-functions, but require much finer near-wall grid to accurately resolve the physics. The three kappa-epsilon models use different approaches to characterize the near wall regions of the flow. Therefore, the limitations imposed by the near wall characteristics have been carefully resolved. The convergence characteristics of a particular model using a given numerical technique are also an important, but most often overlooked, aspect of turbulence model predictions. It is found that some convergence characteristics could be sacrificed for more accurate near-wall prediction. However, even this gain in accuracy is not sufficient to model the effects of an external pressure gradient imposed by a shock-wave/ boundary-layer interaction. Additional work on turbulence models, especially for compressibility, is required since the solutions obtained with base line turbulence are in only reasonable agreement with the experimental data for the viscous interaction problems.

Blood group genotyping for Jk(a)/Jk(b), Fy(a)/Fy(b), S/s, K/k, Kp(a)/Kp(b), Js(a)/Js(b), Co(a)/Co(b), and Lu(a)/Lu(b) with microarray beads.

PubMed

Karpasitou, Katerina; Drago, Francesca; Crespiatico, Loretta; Paccapelo, Cinzia; Truglio, Francesca; Frison, Sara; Scalamogna, Mario; Poli, Francesca

2008-03-01

Traditionally, blood group typing has been performed with serologic techniques, the classical method being the hemagglutination test. Serotyping, however, may present important limitations such as scarce availability of rare antisera, typing of recently transfused patients, and those with a positive direct antiglobulin test. Consequently, serologic tests are being complemented with molecular methods. The aim of this study was to develop a low-cost, high-throughput method for large-scale genotyping of red blood cells (RBCs). Single-nucleotide polymorphisms associated with some clinically important blood group antigens, as well as with certain rare blood antigens, were evaluated: Jk(a)/Jk(b), Fy(a)/Fy(b), S/s, K/k, Kp(a)/Kp(b), Js(a)/Js(b), Co(a)/Co(b), and Lu(a)/Lu(b). Polymerase chain reaction (PCR)-amplified targets were detected by direct hybridization to microspheres coupled to allele-specific oligonucleotides. Cutoff values for each genotype were established with phenotyped and/or genotyped samples. The method was validated with a blind panel of 92 blood donor samples. The results were fully concordant with those provided by hemagglutination assays and/or sequence-specific primer (SSP)-PCR. The method was subsequently evaluated with approximately 800 blood donor and patient samples. This study presents a flexible, quick, and economical method for complete genotyping of large donor cohorts for RBC alleles.

Multiferroic Properties of o-LuMnO3 Controlled by b-Axis Strain

NASA Astrophysics Data System (ADS)

Windsor, Y. W.; Huang, S. W.; Hu, Y.; Rettig, L.; Alberca, A.; Shimamoto, K.; Scagnoli, V.; Lippert, T.; Schneider, C. W.; Staub, U.

2014-10-01

Strain is a leading candidate for controlling magnetoelectric coupling in multiferroics. Here, we use x-ray diffraction to study the coupling between magnetic order and structural distortion in epitaxial films of the orthorhombic (o-) perovskite LuMnO3. An antiferromagnetic spin canting in the E-type magnetic structure is shown to be related to the ferroelectrically induced structural distortion and to a change in the magnetic propagation vector. By comparing films of different orientations and thicknesses, these quantities are found to be controlled by b-axis strain. It is shown that compressive strain destabilizes the commensurate E-type structure and reduces its accompanying ferroelectric distortion.

Multiferroic properties of o-LuMnO3 controlled by b-axis strain.

PubMed

Windsor, Y W; Huang, S W; Hu, Y; Rettig, L; Alberca, A; Shimamoto, K; Scagnoli, V; Lippert, T; Schneider, C W; Staub, U

2014-10-17

Strain is a leading candidate for controlling magnetoelectric coupling in multiferroics. Here, we use x-ray diffraction to study the coupling between magnetic order and structural distortion in epitaxial films of the orthorhombic (o-) perovskite LuMnO(3). An antiferromagnetic spin canting in the E-type magnetic structure is shown to be related to the ferroelectrically induced structural distortion and to a change in the magnetic propagation vector. By comparing films of different orientations and thicknesses, these quantities are found to be controlled by b-axis strain. It is shown that compressive strain destabilizes the commensurate E-type structure and reduces its accompanying ferroelectric distortion.

Accurate assessment of long-term nephrotoxicity after peptide receptor radionuclide therapy with (177)Lu-octreotate.

PubMed

Sabet, Amir; Ezziddin, Khaled; Pape, Ulrich-Frank; Reichman, Karl; Haslerud, Torjan; Ahmadzadehfar, Hojjat; Biersack, Hans-Jürgen; Nagarajah, James; Ezziddin, Samer

2014-03-01

Renal radiation during peptide receptor radionuclide therapy (PRRT) may result in glomerular damage, a potential reduction of glomerular filtration rate (GFR) and ultimately lead to renal failure. While reported PRRT nephrotoxicity is limited to data derived from serum creatinine-allowing only approximate estimates of GFR-the aim of this study is to accurately determine PRRT-induced long-term changes of renal function and associated risk factors according to state-of-the-art GFR measurement. Nephrotoxicity was analysed using (99m)Tc-diethylenetriaminepentaacetic acid (DTPA) clearance data of 74 consecutive patients with gastroenteropancreatic neuroendocrine tumours (GEP NET) undergoing PRRT with (177)Lu-octreotate. The mean follow-up period was 21 months (range 12-50) with a median of five GFR measurements per patient. The change of GFR was analysed by linear curve fit. Potential risk factors including diabetes mellitus, arterial hypertension, previous chemotherapy, renal impairment at baseline and cumulative administered activity were analysed regarding potential impact on renal function loss. In addition, Common Terminology Criteria for Adverse Events (CTCAE) v3.0 were used to compare nephrotoxicity determined by (99m)Tc-DTPA clearance versus serum creatinine. The alteration in GFR differed widely among the patients (mean -2.1 ± 13.1 ml/min/m(2) per year, relative yearly reduction -1.8 ± 18.9%). Fifteen patients (21%) experienced a mild (2-10 ml/min/m(2) per year) and 16 patients (22%) a significant (>10 ml/min/m(2) per year) decline of GFR following PRRT. However, 11 patients (15%) showed an increase of >10 ml/min/m(2) per year. Relevant nephrotoxicity according to CTCAE (grade ≥3) was observed in one patient (1.3%) with arterial hypertension and history of chemotherapy. Nephrotoxicity according to serum creatinine was discordant to that defined by GFR in 15% of the assessments and led to underestimation in 12% of patients. None of the investigated

New genotypes of Liao ning virus (LNV) in Australia exhibit an insect-specific phenotype.

PubMed

Prow, Natalie A; Mah, Marcus G; Deerain, Joshua M; Warrilow, David; Colmant, Agathe M G; O'Brien, Caitlin A; Harrison, Jessica J; McLean, Breeanna J; Hewlett, Elise K; Piyasena, Thisun B H; Hall-Mendelin, Sonja; van den Hurk, Andrew F; Watterson, Daniel; Huang, Bixing; Schulz, Benjamin L; Webb, Cameron E; Johansen, Cheryl A; Chow, Weng K; Hobson-Peters, Jody; Cazier, Chris; Coffey, Lark L; Faddy, Helen M; Suhrbier, Andreas; Bielefeldt-Ohmann, Helle; Hall, Roy A

2018-04-01

Liao ning virus (LNV) was first isolated in 1996 from mosquitoes in China, and has been shown to replicate in selected mammalian cell lines and to cause lethal haemorrhagic disease in experimentally infected mice. The first detection of LNV in Australia was by deep sequencing of mosquito homogenates. We subsequently isolated LNV from mosquitoes of four genera (Culex, Anopheles, Mansonia and Aedes) in New South Wales, Northern Territory, Queensland and Western Australia; the earliest of these Australian isolates were obtained from mosquitoes collected in 1988, predating the first Chinese isolates. Genetic analysis revealed that the Australian LNV isolates formed two new genotypes: one including isolates from eastern and northern Australia, and the second comprising isolates from the south-western corner of the continent. In contrast to findings reported for the Chinese LNV isolates, the Australian LNV isolates did not replicate in vertebrate cells in vitro or in vivo, or produce signs of disease in wild-type or immunodeficient mice. A panel of human and animal sera collected from regions where the virus was found in high prevalence also showed no evidence of LNV-specific antibodies. Furthermore, high rates of virus detection in progeny reared from infected adult female mosquitoes, coupled with visualization of the virus within the ovarian follicles by immunohistochemistry, suggest that LNV is transmitted transovarially. Thus, despite relatively minor genomic differences between Chinese and Australian LNV strains, the latter display a characteristic insect-specific phenotype.

Safety and efficacy of everolimus in gastrointestinal and pancreatic neuroendocrine tumors after (177)Lu-octreotate.

PubMed

Kamp, Kimberly; Gumz, Brenda; Feelders, Richard A; Kwekkeboom, Dik J; Kaltsas, Gregory; Costa, Frederico P; de Herder, Wouter W

2013-12-01

Although (177)Lu-octreotate is an effective treatment for patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs), some patients will fail or develop disease progression necessitating further treatment. We examined whether the safety and efficacy of everolimus after prior treatment with (177)Lu-octreotate is different from the published safety profile of everolimus in GEP-NETs. In this multicenter study, 24 GEP-NET patients were included. Adverse events were assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE), version 3.0. Tumor response was measured according to the Response Evaluation Criteria in Solid Tumors (RECIST), version 1.0. Major clinical adverse events (grade 3 or 4) during treatment with everolimus were hyperglycemia (20.8%), fatigue (8.3%), thrombocytopenia (8.3%), and elevated alanine transaminase levels (8.3%). By radiological review, there were four partial responses (16.7%), five patients (62.5%) with stable disease, and three patients (12.5%) with progressive disease. For two patients (8.3%), no data on tumor response were available. Median progression-free survival (PFS) was 13.1 months (95% CI, 11.5-21.2). Median PFS of the current study was longer when compared with the RADIANT-3 trial (13.1 vs 11.4 months) and shorter when compared with the RADIANT-1 trial (13.1 vs 16.7 months). In conclusion, the safety profile of everolimus is not influenced by previous treatment with peptide receptor radiotherapy.

Preparation and biological evaluation of (177)Lu conjugated PR81 for radioimmunotherapy of breast cancer.

PubMed

Salouti, Mojtaba; Babaei, Mohammad Hossein; Rajabi, Hossein; Rasaee, Mohammad javad

2011-08-01

PR81 is a monoclonal antibody that binds with high affinity to MUC1 antigen that is over expressed in 80% of breast cancers. In this study, we developed a method for indirect labeling of PR81 with lutetium-177 and performed all preclinical qualifications in production of a biologic agent for radioimmunotherapy of breast cancer. The radiochemical purity and in vitro stability of (177)Lu labeled PR81 was determined by instant thin layer chromatography. The immunoreactivity and cell toxicity of the complex were tested on MCF7 cell line. The biodistribution and scintigraphy studies were performed in BALB/c mice with breast tumor. The radiochemical purity was 91.2±3.8% after 2 h. The in vitro stabilities in phosphate buffer and human blood serum were 83.1±3.4% and 76.2±3.6% at 96 h, respectively. The immunoreactivity of the complex was 83.4±2.4%. The cell toxicity study showed that the complex inhibited 85.2±3.4% growth of MCF7 cells at a concentration of 2500 ng/ml after 96 h. The biodistribution and scintigraphy studies showed the accumulation of the complex at the site of tumors with high sensitivity and specificity. The results showed that one may consider (177)Lu-DOTA-PR81 as a potential radiopharmaceutical for therapy of human breast cancer, which needs further investigations. Copyright © 2011 Elsevier Inc. All rights reserved.

Efficient Ho:LuLiF4 laser diode-pumped at 1.15 μm.

PubMed

Wang, Sheng-Li; Huang, Chong-Yuan; Zhao, Cheng-Chun; Li, Hong-Qiang; Tang, Yu-Long; Yang, Nan; Zhang, Shuai-Yi; Hang, Yin; Xu, Jian-Qiu

2013-07-15

We report the first laser operation based on Ho(3+)-doped LuLiF(4) single crystal, which is directly pumped with 1.15-μm laser diode (LD). Based on the numerical model, it is found that the "two-for-one" effect induced by the cross-relaxation plays an important role for the laser efficiency. The maximum continuous wave (CW) output power of 1.4 W is produced with a beam propagation factor of M(2) ~2 at the lasing wavelength of 2.066 μm. The slope efficiency of 29% with respect to absorbed power is obtained.

Spatial distribution and seasonality of Biomphalaria spp. in São Luís (Maranhão, Brazil).

PubMed

David, Nathalia Ferreira; Cantanhede, Selma Patrícia Diniz; Monroe, Natanael Bezerra; Pereira, Luciana Patrícia Lima Alves; Silva-Souza, Nêuton; Abreu-Silva, Ana Lúcia; de Oliveira, Verônica Maria; Tchaicka, Ligia

2018-05-01

Two of the three vector species of Schistosoma mansoni Sambon, 1907 in Brazil occur in the state of Maranhão: Biomphalaria glabrata (Say, 1818) and Biomphalaria straminea (Dunker, 1848). For the implementation of effective measures to combat schistosomiasis, it is necessary to identify the spatial and seasonal dynamics of these snails. Therefore, this work brought together information from malacological survey carried out in São Luís (Maranhão, Brazil) to identify the spatial and seasonal distribution patterns of Biomphalaria spp. snails. We used data from malacological surveys of the Municipal Health Secretary of São Luís, conducted between 2006 and 2013 in 23 neighborhoods. We also used data from the mollusk surveys that we conducted for 2 years (2012-2014) in four of these neighborhoods. During the 8-year period (2006-2013), 15,990 specimens of Biomphalaria spp. were collected. There was a positive association between precipitation and the abundance of mollusks of the genus Biomphalaria. During 2012-2014, a total of 2487 snail specimens were obtained (B. glabrata: 1046 specimens; B. straminea: 1426 specimens). There was a positive correlation between precipitation and B. straminea abundance. High density of human occupation and high precipitation are two factors that affect the distribution and density of Biomphalaria spp.

LU-HF Age of Martian Meteorite Larkman Nunatek 06319

NASA Technical Reports Server (NTRS)

Shafer, J. T.; Brandon, A. D.; Lapen, T. J.; Righter, M.; Beard, B.; Peslier, A. H.

2009-01-01

Lu-Hf isotopic data were collected on mineral separates and bulk rock powders of LAR 06319, yielding an age of 197+/- 29 Ma. Sm-Nd isotopic data and in-situ LA-ICP-MS data from a thin section of LAR 06319 are currently being collected and will be presented at the 2009 LPSC. These new data for LAR 06319 extend the existing data set for the enriched shergottite group. Martian meteorites represent the only opportunity for ground truth investigation of the geochemistry of Mars [1]. At present, approximately 80 meteorites have been classified as Martian based on young ages and distinctive isotopic signatures [2]. LAR 06319 is a newly discovered (as part of the 2006 ANSMET field season) martian meteorite that represents an important opportunity to further our understanding of the geochemical and petrological constraints on the origin of Martian magmas. Martian meteorites are traditionally categorized into the shergottite, nakhlite, and chassignite groups. The shergottites are further classified into three distinct isotopic groups designated depleted, intermediate, and enriched [3,4] based on the isotope systematics and compositions of their source(s).

Formation of medical radioisotopes {sup 111}In, {sup 117m}Sn, {sup 124}Sb, and {sup 177}Lu in photonuclear reactions

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

Danagulyan, A. S.; Hovhannisyan, G. H., E-mail: hov-gohar@ysu.am; Bakhshiyan, T. M.

2015-06-15

The possibility of the photonuclear production of radioisotopes {sup 111}In, {sup 117m}Sn, {sup 124}Sb, and {sup 177}Lu is discussed. Reaction yields were measured by the gamma-activation method. The enriched tin isotopes {sup 112,} {sup 118}Sn and Te and HfO{sub 2} of natural isotopic composition were used as targets. The targets were irradiated at the linear electron accelerator of Alikhanian National Science Laboratory (Yerevan) at the energy of 40 MeV. The experimental results obtained in this way reveal that the yield and purity of radioisotopes {sup 111}In and {sup 117}mSn are acceptable for their production via photonuclear reactions. Reactions proceeding onmore » targets from Te and HfO{sub 2} of natural isotopic composition and leading to the formation of {sup 124}Sb and {sup 177}Lu have small yields and are hardly appropriate for the photoproduction of these radioisotopes even in the case of enriched targets.« less

Luminescence properties of Lu2O3: Tb film prepared by Pechini sol-gel method

NASA Astrophysics Data System (ADS)

Shen, Siqing; Wang, Jian; Xu, Zhibin; Xie, Jianjun; Shi, Ying

2010-10-01

Uniform and crack free Tb3+ doped lutetium oxide (Lu2O3:Tb) films were prepared by Pechini sol-gel method combined with the spin-coating technique. The influence of the different substrate (monocrystalline silicon (111) and silica glass) and atmosphere (N2 and Air) on the luminescence properties of films was investigated. According to the emission spectra, we found that the luminous intensity was higher on silica glass substrate. Moreover, it was found that the luminous intensity calcined in N2 was higher almost twice as that calcined in air.

Luminescence properties of Lu2O3: Tb film prepared by Pechini sol-gel method

NASA Astrophysics Data System (ADS)

Shen, Siqing; Wang, Jian; Xu, Zhibin; Xie, Jianjun; Shi, Ying

2011-02-01

Uniform and crack free Tb3+ doped lutetium oxide (Lu2O3:Tb) films were prepared by Pechini sol-gel method combined with the spin-coating technique. The influence of the different substrate (monocrystalline silicon (111) and silica glass) and atmosphere (N2 and Air) on the luminescence properties of films was investigated. According to the emission spectra, we found that the luminous intensity was higher on silica glass substrate. Moreover, it was found that the luminous intensity calcined in N2 was higher almost twice as that calcined in air.

Two-step photoconductivity in LiY x Lu1 - x F4:Ce,Yb crystals

NASA Astrophysics Data System (ADS)

Nurtdinova, L. A.; Korableva, S. L.; Leontiev, A. V.

2016-10-01

Photoconductivity of LiY x Lu1- x F4:Ce,Yb ( x = 0-1) crystals is measured under one- and two-step excitation. It is established that the photoconductivity is due to intra-center transitions from excited states of Ce3+ ions. The position of the ground 4 f-state of Ce3+ ion relative to the bottom of the conduction band is determined. The choice of pumping conditions to obtain the lasing on the 5 d-4 f transitions of trivalent cerium in these active media is substantiated.

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

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

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

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

Health-Related Quality of Life in Patients With Progressive Midgut Neuroendocrine Tumors Treated With 177Lu-Dotatate in the Phase III NETTER-1 Trial.

PubMed

Strosberg, Jonathan; Wolin, Edward; Chasen, Beth; Kulke, Matthew; Bushnell, David; Caplin, Martyn; Baum, Richard P; Kunz, Pamela; Hobday, Timothy; Hendifar, Andrew; Oberg, Kjell; Sierra, Maribel Lopera; Thevenet, Thomas; Margalet, Ines; Ruszniewski, Philippe; Krenning, Eric

2018-06-07

Purpose Neuroendocrine tumor (NET) progression is associated with deterioration in quality of life (QoL). We assessed the impact of 177 Lu-Dotatate treatment on time to deterioration in health-related QoL. Methods The NETTER-1 trial is an international phase III study in patients with midgut NETs. Patients were randomly assigned to treatment with 177 Lu-Dotatate versus high-dose octreotide. European Organisation for Research and Treatment of Cancer quality-of-life questionnaires QLQ C-30 and G.I.NET-21 were assessed during the trial to determine the impact of treatment on health-related QoL. Patients completed the questionnaires at baseline and every 12 weeks until tumor progression. QoL scores were converted to a 100-point scale according to European Organisation for Research and Treatment of Cancer instructions, and individual changes from baseline scores were assessed. Time to QoL deterioration (TTD) was defined as the time from random assignment to the first QoL deterioration ≥ 10 points for each patient in the corresponding domain scale. All analyses were conducted on the intention-to-treat population. Patients with no deterioration were censored at the last QoL assessment date. Results TTD was significantly longer in the 177 Lu-Dotatate arm (n = 117) versus the control arm (n = 114) for the following domains: global health status (hazard ratio [HR], 0.406), physical functioning (HR, 0.518), role functioning (HR, 0.580), fatigue (HR, 0.621), pain (HR, 0.566), diarrhea (HR, 0.473), disease-related worries (HR, 0.572), and body image (HR, 0.425). Differences in median TTD were clinically significant in several domains: 28.8 months versus 6.1 months for global health status, and 25.2 months versus 11.5 months for physical functioning. Conclusion This analysis from the NETTER-1 phase III study demonstrates that, in addition to improving progression-free survival, 177 Lu-Dotatate provides a significant QoL benefit for patients with progressive midgut NETs

Lu-Hf isotopic memory of plume-lithosphere interaction in the source of layered mafic intrusions, Windimurra Igneous Complex, Yilgarn Craton, Australia

NASA Astrophysics Data System (ADS)

Nebel, O.; Arculus, R. J.; Ivanic, T. J.; Nebel-Jacobsen, Y. J.

2013-10-01

Most layered mafic intrusions (LMI) are formed via multiple magma injections into crustal magma chambers. These magmas are originally sourced from the mantle, likely via plume activity, but may interact with the overriding lithosphere during ascent and emplacement in the crust. The magma injections lead to the establishment of different layers and zones with complex macroscopic, microscopic and cryptic compositional layering through magmatic differentiation and associated cumulate formation, sometimes accompanied by crustal assimilation. These complex mineralogical and petrological processes obscure the nature of the mantle sources of LMI, and typically have limited the degree to which parental liquids can be fully characterised. Here, we present Lu-Hf isotope data for samples from distinct layers of the Upper Zone of the Windimurra Igneous Complex (WIC), an immense late-Archean LMI in the West Australian Yilgarn Craton. Lu-Hf isotope systematics of whole rocks are well correlated (MSWD=5.6, n=17) with an age of ˜3.05±0.05 Ga and initial ɛHf˜+8. This age, however, is older than whole rock Sm-Nd and zircon U-Pb ages of the intrusion, both of which are ca. 2.8 Ga. Stratigraphically-controlled initial Hf isotope variations (associated with multiple episodes of emplacement at ca. 2.8 Ga) indicate isotope mixing between a near-chondritic and an ultra-radiogenic component, the latter with ɛHf[2.8 Ga]>+15. This Hf isotope mixing creates a pseudochron-relationship at the time of intrusion of ˜250 Myr that is superimposed on subsequent radiogenic ingrowth after crystallisation, generating an age that predates the actual emplacement event. Mixing between late-stage crystallisation products (melt + crystals) from the Middle Zone and replenishing, plume-derived liquids was followed by crystal accumulation in a chemically evolving magma chamber. The ultra-radiogenic Hf isotope endmember in the WIC mantle source requires parent-daughter ratios consistent with very early

Fate of Lu(III) sorbed on 2-line ferrihydrite at pH 5.7 and aged for 12 years at room temperature. I: insights from ICP-OES, XRD, ESEM, AsFlFFF/ICP-MS, and EXAFS spectroscopy.

PubMed

Finck, Nicolas; Bouby, Muriel; Dardenne, Kathy

2018-01-31

Two-line ferrihydrite (2LFh) was aged for 12 years under ambient conditions and sheltered from light in the presence of Lu(III) used as surrogate for trivalent actinides. 2LFh aging produced hematite rhombohedra with overgrown acicular goethite particles. Analysis of the homogeneous suspension by asymmetrical flow field-flow fractionation (AsFlFFF) coupled to ICP-MS indicated that particles have a mean hydrodynamic diameter of about 140 nm and the strong correlation of the Fe and Lu fractograms hinted at a structural association of the lanthanide with the solid phase(s). Unfortunately, recoveries were low and thus results cannot be considered representative of the whole sample. The suspension was centrifuged and X-ray absorption spectroscopy (XAS) at the Lu L 3 -edge on the settled particles indicated that Lu(III) is sixfold coordinated by oxygen atoms, pointing to a retention by structural incorporation within particles. This result is consistent with AsFlFFF results on the same suspension without centrifugation. The detection of next nearest Fe and O atoms were consistent with the structure of goethite, ruling out incorporation within hematite. After centrifugation of the suspension, only nanoparticulate needle-like particles, very likely goethite, could be detected in the supernatant by ESEM. AsFlFFF data of the supernatant were comparable to that obtained for the homogeneous suspension, whereas XAS indicated that Lu(III) is predominantly present as dissolved species in the supernatant. Results from both techniques can be interpreted as a major fraction of Lu present as aqueous ions and a minor fraction as structurally incorporated. Findings from this study are corroborated by STEM-HAADF data and results from DFT calculations in a companion paper.

Long-term hematotoxicity after peptide receptor radionuclide therapy with 177Lu-octreotate.

PubMed

Sabet, Amir; Ezziddin, Khaled; Pape, Ulrich-Frank; Ahmadzadehfar, Hojjat; Mayer, Karin; Pöppel, Thorsten; Guhlke, Stefan; Biersack, Hans-Jürgen; Ezziddin, Samer

2013-11-01

Myelosuppression may be the dose-limiting toxicity in peptide receptor radionuclide therapy (PRRT). The aim of this study was to investigate the incidence, severity, and reversibility of long-term hematotoxicity in a large cohort of patient undergoing PRRT with (177)Lu-octreotate for metastatic neuroendocrine tumors. The impact of potential risk factors, including initial cytopenia, advanced bone metastatic disease, previous chemotherapy, and cumulative administered activity, and the protective effects of splenectomy were of particular interest. A total of 632 PRRT courses were performed in 203 patients with metastatic neuroendocrine tumors. A mean activity of 7.9 GBq of (177)Lu-octreotate was administered per treatment cycle, with a goal of 4 courses at standard intervals of 3 mo. Hematologic parameters were determined before each treatment course, at 2- to 4-wk intervals between the courses, 8-12 wk after the last course of PRRT, and at 3-month intervals for further follow-up. Toxicity was recorded with Common Terminology Criteria for Adverse Events (version 3.0). Myelodysplastic syndrome as a delayed adverse event was documented in 3 patients (1.4%). Relevant but reversible hematotoxicity (grade 3 or 4) occurred in 23 patients (11.3%) and 29 administrations (4.6%), with leukopenia in 2.7% and thrombocytopenia in 1.7%. The mean time to blood count recovery was 12 mo after the termination of PRRT (range, 3-22 mo). The only preexisting factor that contributed to hematotoxicity was initial cytopenia (P < 0.001). A high level of cumulative administered activity (>29.6 GBq) was associated with relevant leukopenia (P < 0.001). None of the patients with a history of splenectomy developed grade 3 or 4 hematotoxicity, and splenectomy was inversely associated with the incidence and degree of leukopenia (P = 0.02) and thrombocytopenia (P = 0.03). PRRT-induced myelosuppression is almost invariably reversible and rarely requires clinical measures. Administered activity and

Proton and Gamma Radiation Effects in Undoped, Single-doped and co-doped YLiF4 and LuLiF4

NASA Technical Reports Server (NTRS)

Lee, Hyung; Bai, Yingxin; Yu, Kirong; Singh, U.

2009-01-01

Proton and gamma radiation effects in various YLiF4 and LuLiF4 crystals have been investigated. The radiation induced color centers compared with six different kinds of crystal samples in ranges up to 200 krads and 200 MeV. The radiation induced absorption coefficients are strongly dependent on polarization and concentration of rare-earth ions.

Molecular characterization of Hepatozoon sp. in cats from São Luís Island, Maranhão, Northeastern Brazil.

PubMed

de Bortoli, Caroline P; André, Marcos R; Braga, Maria do Socorro C; Machado, Rosangela Zacarias

2011-10-01

Few molecular studies have been done concerning the molecular characterization of Hepatozoon species among domestic and wild felids. The present work aimed to characterize molecularly the presence of Hepatozoon sp. DNA in cat blood samples from São Luís Island, Maranhão state, Northeastern Brazil. EDTA-whole blood samples were collected from 200 domestic cats with outdoor and wood areas access from São Luís, Maranhão, Brazil. Each sample of extracted DNA was used as a template in PCR reactions aiming to amplify a partial sequence of 18S rRNA of Hepatozoon spp. We also performed sequence alignment to establish the identity of the parasite species infecting these animals using DNA sequences based on 18S rRNA. From 200 sampled cats, Hepatozoon DNA was only found in one animal (0.5%). The found Hepatozoon DNA showed 97% of identity with Hemobartonella felis isolates 1 and 2 from Spain. When analyzing the phylogenetic tree, the found Hepatozoon DNA was in the same clade than H. felis isolates. Our findings suggest that more than one species of Hepatozoon could infect felids in Brazil.

PET/CT alignment calibration with a non-radioactive phantom and the intrinsic 176Lu radiation of PET detector

NASA Astrophysics Data System (ADS)

Wei, Qingyang; Ma, Tianyu; Wang, Shi; Liu, Yaqiang; Gu, Yu; Dai, Tiantian

2016-11-01

Positron emission tomography/computed tomography (PET/CT) is an important tool for clinical studies and pre-clinical researches which provides both functional and anatomical images. To achieve high quality co-registered PET/CT images, alignment calibration of PET and CT scanner is a critical procedure. The existing methods reported use positron source phantoms imaged both by PET and CT scanner and then derive the transformation matrix from the reconstructed images of the two modalities. In this paper, a novel PET/CT alignment calibration method with a non-radioactive phantom and the intrinsic 176Lu radiation of the PET detector was developed. Firstly, a multi-tungsten-alloy-sphere phantom without positron source was designed and imaged by CT and the PET scanner using intrinsic 176Lu radiation included in LYSO. Secondly, the centroids of the spheres were derived and matched by an automatic program. Lastly, the rotation matrix and the translation vector were calculated by least-square fitting of the centroid data. The proposed method was employed in an animal PET/CT system (InliView-3000) developed in our lab. Experimental results showed that the proposed method achieves high accuracy and is feasible to replace the conventional positron source based methods.

The Cell-CT 3D Cell Imaging Technology Platform Enables the Detection of Lung Cancer Using the Non-Invasive LuCED Sputum Test

PubMed Central

Meyer, Michael G.; Hayenga, Jon; Neumann, Thomas; Katdare, Rahul; Presley, Chris; Steinhauer, David; Bell, Timothy; Lancaster, Christy; Nelson, Alan C.

2015-01-01

The war against cancer has yielded important advances in the early diagnosis and treatment of certain cancer types, but the poor detection rate and 5-year survival rate for lung cancer remains little changed over the past 40 years. Early detection through emerging lung cancer screening programs promises the most reliable means of improving mortality. Sputum cytology has been tried without success because sputum contains few malignant cells that are difficult for cytologists to detect. However, research has shown that sputum contains diagnostic malignant cells and could serve as a means of lung cancer detection if those cells could be detected and correctly characterized. Recently, the National Lung Cancer Screening Trial reported that screening by three consecutive low-dose X-ray CT scans provides a 20% reduction in lung cancer mortality compared to chest X-ray. This reduction in mortality, however, comes with an unacceptable false positive rate that increases patient risks and the overall cost of lung cancer screening. This article reviews the LuCED® test for detecting early lung cancer. LuCED is based on patient sputum that is enriched for bronchial epithelial cells. The enriched sample is then processed on the Cell-CT®, which images cells in three dimensions with sub-micron resolution. Algorithms are applied to the 3D cell images to extract morphometric features that drive a classifier to identify cells that have abnormal characteristics. The final status of these candidate abnormal cells is established by the pathologist's manual review. LuCED promotes accurate cell classification which could enable cost effective detection of lung cancer. PMID:26148817

Effect of sintering temperature of Ce3+-doped Lu3Al5O12 phosphors on light emission and properties of crystal structure for white-light-emitting diodes

NASA Astrophysics Data System (ADS)

Koizumi, Hiroshi; Watabe, Junya; Sugiyama, Shin; Hirabayashi, Hideaki; Homma, Tetsuya

2018-06-01

The effect of the sintering temperature of Ce3+-doped Lu3Al5O12 (Ce-LuAG) phosphors on the emission and properties of the crystal structure was studied. A cathodoluminescence peak at 317 nm, which was assigned to lattice defects, was exhibited in addition to emission peaks at 508 and 540 nm for the Ce-LuAG phosphors. The intensities of the 317 nm emission peak for the phosphors with mean particle diameters of 5.0 and 10.0 µm formed at a low sintering temperature of 1430 °C were higher than those for the phosphors with mean particle diameters of 18.0 and 20.5 µm formed at a high sintering temperature of 1550 °C. In contrast, the electroluminescence spectra for fabricated white-light-emitting diodes (LEDs) using the phosphors revealed that the intensity of the peak at 540 nm was strong for the mean particle diameters of 18.0 and 20.5 µm. The intensity of the 540 nm peak, which is attributed to the 4f→5d transition of the Ce3+ activator, showed a dependence on the sintering temperature. The relationship between the optical properties and the lattice defects is discussed.

Broadly wavelength tunable acousto-optically Q-switched Tm:Lu2SiO5 laser.

PubMed

Feng, T; Yang, K; Zhao, S; Zhao, J; Qiao, W; Li, T; Zheng, L; Xu, J

2014-09-20

A broadly wavelength tunable acousto-optically Q-switched Tm:Lu2SiO5 (Tm:LSO) laser is presented for the first time, to our best knowledge. The emission wavelength was tuned in a broad spectral region over 111 nm ranging from 1959 to 2070 nm. A shortest pulse duration of 345 ns with beam quality of M(2)≤1.65 was obtained at pulse repetition frequency (PRF) of 1 kHz, corresponding to a maximum single pulse energy of 0.26 mJ and peak power of 0.75 kW. The experimental results indicated that Tm:LSO crystal has outstanding potential for obtaining broadly wavelength tunable and low-PRF laser pulses at 2 μm.

Application of single-vial ready-for-use formulation of 111In- or 177Lu-labelled somatostatin analogs.

PubMed

de Blois, Erik; Chan, Ho Sze; de Zanger, Rory; Konijnenberg, Mark; Breeman, Wouter A P

2014-02-01

For the sake of safety it would be desirable to store and transport the ready-for-use liquid formulation (diagnostics and therapeutics) of radiolabelled peptides. The use of ethanol, in combination with a mixture of gentisic- and ascorbic acid, has superior effects on stabilizing radiolabelled somatostatin analogs. As a consequence, (111)In- and (177)Lu-labelled somatostatin analogs can be stored and transported in a single-vial ready-for-use liquid formulation up to 7 days after radiolabelling. © 2013 Published by Elsevier Ltd.

Hybrid 2D photonic crystal-assisted Lu3Al5O12:Ce ceramic-plate phosphor and free-standing red film phosphor for white LEDs with high color-rendering index.

PubMed

Park, Hoo Keun; Oh, Ji Hye; Kang, Heejoon; Zhang, Jian; Do, Young Rag

2015-03-04

This paper reports the combined optical effects of a two-dimensional (2D) SiNx photonic crystal layer (PCL)-assisted Lu3Al5O12:Ce (LuAG:Ce) green ceramic-plate phosphor (CPP) and a free-standing (Sr,Ca)AlSiN3:Eu red film phosphor to enhance luminous efficacy, color rendering index (CRI), and special CRI (R9) of LuAG:Ce CPP-capped white light-emitting diodes (LEDs) for high-power white LEDs at 350 mA. By introducing the 2D SiNx PCL, the luminous efficacy was improved by a factor of 1.25 and 1.15 compared to that of the conventional flat CPP-capped LED and the thickness-increased CPP-capped LED (with a thickness of 0.15 mm), respectively, while maintaining low color-rendering properties. The combining of the free-standing red film phosphor in the flat CPP-capped, the 2D PCL-assisted CPP-capped, and the thickness-increased CPP-capped LEDs led to enhancement of the CRI and the special CRI (R9); it also led to a decrease of the correlated color temperature (CCT) due to broad wavelength coverage via the addition of red emission. High CRI (94), natural white CCT (4450 K), and acceptable luminous efficacy (71.1 lm/W) were attained from the 2D PCL-assisted LuAG:Ce CPP/free-standing red film phosphor-based LED using a red phosphor concentration of 7.5 wt %. It is expected that the combination of the 2D PCL and the free-standing red film phosphor will be a good candidate for achieving a high-power white CPP-capped LED with excellent CRI.

A temperature sensor based on the enhanced upconversion luminescence of Li+ doped NaLuF4:Yb3+,Tm3+/Er3+ nano/microcrystals.

PubMed

Qiang, Qinping; Du, Shanshan; Ma, Xinlong; Chen, Wenbo; Zhang, Gangyi; Wang, Yuhua

2018-05-09

In this paper, fluorescent and optical temperature sensing bi-functional Li+-doping NaLuF4:Ln (Ln = Yb3+, Tm3+/Er3+) nanocrystals were synthesized via a simple hydrothermal method using oleic acid as a capping ligand. The crystal phase, size, upconversion (UC) properties, and optical temperature sensing characteristics of the crystals can be easily modified by Li+ doping. The results reveal that additional Li+ can promote the transformation from the hexagonal phase to the cubic phase and reduce the size of the nanocrystals. In addition, NaLuF4:Ln (Ln = Yb3+, Tm3+, Li+) nanocrystals present efficient near infrared (NIR) emission, which is beneficial for in vivo biomedical applications due to the increased penetration depth and low radiation damage of NIR light in bio-tissues. More importantly, under 980 nm excitation, the temperature dependent UCL from the 2H11/2 and 4S3/2 levels of Er3+ ions in NaLuF4:Yb3+,Er3+,Li+ microcrystals was investigated systematically. The fluorescence intensity ratios (FIR) of the pairs of thermally coupled levels were studied as a function of temperature in the range of 298-523 K. The maximum sensor sensitivities were found to be about 0.0039 K-1 (523 K) by exploiting the UC emissions from the 2H11/2 and 4S3/2 levels. This suggests that the Li+-doped upconversion luminescence (UCL) materials are promising prototypes for application as multi-mode probes for use in bio-separation and optical thermometers.

Investigating the Effect of Ligand Amount and Injected Therapeutic Activity: A Simulation Study for 177Lu-Labeled PSMA-Targeting Peptides

PubMed Central

Schuchardt, Christiane; Kulkarni, Harshad R.; Shahinfar, Mostafa; Singh, Aviral; Glatting, Gerhard; Baum, Richard P.; Beer, Ambros J.

2016-01-01

In molecular radiotherapy with 177Lu-labeled prostate specific membrane antigen (PSMA) peptides, kidney and/or salivary glands doses limit the activity which can be administered. The aim of this work was to investigate the effect of the ligand amount and injected activity on the tumor-to-normal tissue biologically effective dose (BED) ratio for 177Lu-labeled PSMA peptides. For this retrospective study, a recently developed physiologically based pharmacokinetic model was adapted for PSMA targeting peptides. General physiological parameters were taken from the literature. Individual parameters were fitted to planar gamma camera measurements (177Lu-PSMA I&T) of five patients with metastasizing prostate cancer. Based on the estimated parameters, the pharmacokinetics of tumor, salivary glands, kidneys, total body and red marrow was simulated and time-integrated activity coefficients were calculated for different peptide amounts. Based on these simulations, the absorbed doses and BEDs for normal tissue and tumor were calculated for all activities leading to a maximal tolerable kidney BED of 10 Gy2.5/cycle, a maximal salivary gland absorbed dose of 7.5 Gy/cycle and a maximal red marrow BED of 0.25 Gy15/cycle. The fits yielded coefficients of determination > 0.85, acceptable relative standard errors and low parameter correlations. All estimated parameters were in a physiologically reasonable range. The amounts (for 25−29 nmol) and pertaining activities leading to a maximal tumor dose, considering the defined maximal tolerable doses to organs of risk, were calculated to be 272±253 nmol (452±420 μg) and 7.3±5.1 GBq. Using the actually injected amount (235±155 μg) and the same maximal tolerable doses, the potential improvement for the tumor BED was 1–3 fold. The results suggest that currently given amounts for therapy are in the appropriate order of magnitude for many lesions. However, for lesions with high binding site density or lower perfusion, optimizing the

Investigating the Effect of Ligand Amount and Injected Therapeutic Activity: A Simulation Study for 177Lu-Labeled PSMA-Targeting Peptides.

PubMed

Kletting, Peter; Schuchardt, Christiane; Kulkarni, Harshad R; Shahinfar, Mostafa; Singh, Aviral; Glatting, Gerhard; Baum, Richard P; Beer, Ambros J

2016-01-01

In molecular radiotherapy with 177Lu-labeled prostate specific membrane antigen (PSMA) peptides, kidney and/or salivary glands doses limit the activity which can be administered. The aim of this work was to investigate the effect of the ligand amount and injected activity on the tumor-to-normal tissue biologically effective dose (BED) ratio for 177Lu-labeled PSMA peptides. For this retrospective study, a recently developed physiologically based pharmacokinetic model was adapted for PSMA targeting peptides. General physiological parameters were taken from the literature. Individual parameters were fitted to planar gamma camera measurements (177Lu-PSMA I&T) of five patients with metastasizing prostate cancer. Based on the estimated parameters, the pharmacokinetics of tumor, salivary glands, kidneys, total body and red marrow was simulated and time-integrated activity coefficients were calculated for different peptide amounts. Based on these simulations, the absorbed doses and BEDs for normal tissue and tumor were calculated for all activities leading to a maximal tolerable kidney BED of 10 Gy2.5/cycle, a maximal salivary gland absorbed dose of 7.5 Gy/cycle and a maximal red marrow BED of 0.25 Gy15/cycle. The fits yielded coefficients of determination > 0.85, acceptable relative standard errors and low parameter correlations. All estimated parameters were in a physiologically reasonable range. The amounts (for 25-29 nmol) and pertaining activities leading to a maximal tumor dose, considering the defined maximal tolerable doses to organs of risk, were calculated to be 272±253 nmol (452±420 μg) and 7.3±5.1 GBq. Using the actually injected amount (235±155 μg) and the same maximal tolerable doses, the potential improvement for the tumor BED was 1-3 fold. The results suggest that currently given amounts for therapy are in the appropriate order of magnitude for many lesions. However, for lesions with high binding site density or lower perfusion, optimizing the peptide

Physiological and proteomic analyses of the drought stress response in Amygdalus Mira (Koehne) Yü et Lu roots.

PubMed

Cao, Yuan; Luo, Qiuxiang; Tian, Yan; Meng, Fanjuan

2017-02-27

Plants are oftentimes exposed to many types of abiotic stresses. Drought is one of the main environmental stresses which limits plant growth, distribution and crop yield worldwide. Amygdalus mira (Koehne) Yü et Lu is an important wild peach, and it is considered an ideal wild peach germplasm for improving cultivated peach plants. Because of the loss of genetic variation, cultivated peach plants are sensitive to biotic and abiotic stresses. Wild peach germplasm can offer many useful genes for peach improvement. Responses to drought by withholding water have been studied in Amygdalus mira (Koehne) Yü et Lu roots. In this study, plants were divided into well-watered (control) and water-stressed (treatment) groups, and the treatment group did not receive water until the recovery period (day 16). Several physiological parameters, including root water content and root length, were reduced by drought stress and recovered after rewatering. In addition, the relative conductivity, the levels of proline, MDA and H 2 O 2 , and the activities of ROS scavenging enzymes (POD, APX and CAT) were increased, and none of these factors, except the level of proline, recovered after rewatering. In total, 95 differentially expressed proteins were revealed after drought. The identified proteins refer to a extensive range of biological processes, molecular functions and cellular components, including cytoskeleton dynamics (3.16% of the total 95 proteins), carbohydrate and nitrogen metabolism (6.33% of the total 95 proteins), energy metabolism (7.37% of the total 95 proteins), transcription and translation (18.95% of the total 95 proteins), transport (4.21% of the total 95 proteins), inducers (3.16% of the total 95 proteins), stress and defense (26.31% of the total 95 proteins), molecular chaperones (9.47% of the total 95 proteins), protein degradation (3.16% of the total 95 proteins), signal transduction (7.37% of the total 95 proteins), other materials metabolism (5.26% of the total 95

The first Lu-Hf zircon isotope data for gabbro-diorite-tonalite associations of the Urals

NASA Astrophysics Data System (ADS)

Ronkin, Yu. L.; Smirnov, V. N.; Ivanov, K. S.; Gerdes, A.

2017-01-01

The Lu-Hf isotope systematics of zircon from the gabbro-plagiogranite association (gabbro, diorite, tonalite, and plagiogranite), which is one of the most typical associations of igneous rocks in the Urals, was studied for the first time. The isotope study yielded a unified age limit of 433 Ma, which corresponds to the time of formation of this rock association. The younger "rejuvenated" ages characterize superimposed thermal impact events, induced by the volcanic arc activity, as well as collisional and postcollisional processes. Here, the initial 176Hf/177Hf( t) ratio in the studied zircon from gabbro and plagiogranite corresponds in fact to a highly LILE-depleted (DM) mantle.

CW and passively Q-switched laser performance of Nd:Lu2SiO5 crystal

NASA Astrophysics Data System (ADS)

Xu, Xiaodong; Di, Juqing; Zhang, Jian; Tang, Dingyuan; Xu, Jun

2016-01-01

We demonstrated an efficient and controllable dual-wavelength continuous-wave (CW) laser of Nd:Lu2SiO5 (Nd:LSO) crystal. The maximum output power was 3.02 W at wavelength of 1075 nm and 1079 nm, and with increasing of absorbed pump power, the ratio of 1079 nm laser rose. The slope efficiency of 65.6% and optical-to-optical conversion efficiency of 63.3% were obtained. The passively Q-switched laser properties of Nd:LSO were investigated for the first time. The shortest pulse, maximum pulse energy and peak power were 11.58 ns, 29.05 μJ and 2.34 kW, respectively.

U-Th-Pb, Sm-Nd, Rb-Sr, and Lu-Hf systematics of returned Mars samples

NASA Technical Reports Server (NTRS)

Tatsumoto, M.; Premo, W. R.

1988-01-01

The advantage of studying returned planetary samples cannot be overstated. A wider range of analytical techniques with higher sensitivities and accuracies can be applied to returned samples. Measurement of U-Th-Pb, Sm-Nd, Rb-Sr, and Lu-Hf isotopic systematics for chronology and isotopic tracer studies of planetary specimens cannot be done in situ with desirable precision. Returned Mars samples will be examined using all the physical, chemical, and geologic methods necessary to gain information on the origin and evolution of Mars. A returned Martian sample would provide ample information regarding the accretionary and evolutionary history of the Martian planetary body and possibly other planets of our solar system.

Comparative study of fluvial lakes in floodplains of the Elbe, Lužnice and Svratka Rivers based on hydrochemical and biological approach.

PubMed

Havlíková, Petra; Chuman, Tomáš; Janský, Bohumír

2017-11-17

The aim of the thesis was to specify key differences in chemistry and biota (zooplankton communities) among fluvial lakes in three regions of the Czech Republic: the central part of the Elbe River, the upper part of the Lužnice River and the upper part of the Svratka River. The ten studied lakes of the three regions differ in size, geology, shading, connection with the river and the level of anthropogenic impact. The following hypotheses were tested: (1) The water chemistry of fluvial lakes significantly differs in different floodplains. In the central Elbe River floodplain, there are the highest values of conductivity and concentrations of organic matter and nutrients. Fluvial lakes of the Svratka River floodplain show the lowest level of these parameters, and fluvial lakes of the upper Lužnice River have levels intermediate between the two previous regions. (2) The chemistry of fluvial lakes that have contact with the river through surface connection is significantly influenced by the river. (3) The structure of zooplankton differs in different lakes due to the geographical distance between locations, their different altitude and water chemistry. The PCA analysis of selected parameters of the water chemistry revealed a close relationship of locations in the central Elbe River floodplain on the one side and close relationship of the locations in the upper Lužnice River and Svratka River on the other. However, the amount of organic matter, nitrogen (with the exception of nitrates) and phosphorus was independent of the region. The relationship between the extent of the lake-river connection and the water chemistry was not significant. The hypothesis that the zooplankton differ in different lakes was not proved-the species composition was similar in all the lakes.

Bonding in gold-rare earth [Au2M] (M = Eu, Yb, Lu) ions. A strong covalent gold-lanthanide bond

NASA Astrophysics Data System (ADS)

Páez-Hernández, Dayán; Muñoz-Castro, Alvaro; Arratia-Perez, Ramiro

2017-09-01

The electronic structure and bonding nature of a series of intermetallic gold-lanthanide [Au2Ln] molecules, where Ln = Eu, Yb, Lu is predicted via the DFT and CASSCF/CASPT2 calculations. The 2c-2e bond model shows a good description of the intermetallic bonding which have a large covalent component with important contribution from bonding interaction between the 6s-Au and the 6s-Ln shell of orbitals.

Red Marrow-Absorbed Dose for Non-Hodgkin Lymphoma Patients Treated with 177Lu-Lilotomab Satetraxetan, a Novel Anti-CD37 Antibody-Radionuclide Conjugate.

PubMed

Blakkisrud, Johan; Løndalen, Ayca; Dahle, Jostein; Turner, Simon; Holte, Harald; Kolstad, Arne; Stokke, Caroline

2017-01-01

Red marrow (RM) is often the primary organ at risk in radioimmunotherapy; irradiation of marrow may induce short- and long-term hematologic toxicity. 177 Lu-lilotomab satetraxetan is a novel anti-CD37 antibody-radionuclide conjugate currently in phase 1/2a. Two predosing regimens have been investigated, one with 40 mg of unlabeled lilotomab antibody (arm 1) and one without (arm 2). The aim of this work was to compare RM-absorbed doses for the two arms and to correlate absorbed doses with hematologic toxicity. Eight patients with relapsed CD37+ indolent B-cell non-Hodgkin lymphoma were included for RM dosimetry. Hybrid SPECT and CT images were used to estimate the activity concentration in the RM of L2-L4. Pharmacokinetic parameters were calculated after measurement of the 177 Lu-lilotomab satetraxetan concentration in blood samples. Adverse events were graded according to the Common Terminology Criteria for Adverse Events, version 4.0. The mean absorbed doses to RM were 0.9 mGy/MBq for arm 1 (lilotomab+) and 1.5 mGy/MBq for arm 2 (lilotomab-). There was a statistically significant difference between arms 1 and 2 (Student t test, P = 0.02). Total RM-absorbed doses ranged from 67 to 127 cGy in arm 1 and from 158 to 207 cGy in arm 2. For blood, the area under the curve was higher with lilotomab predosing than without (P = 0.001), whereas the volume of distribution and the clearance of 177 Lu-lilotomab satetraxetan was significantly lower (P = 0.01 and P = 0.03, respectively). Patients with grade 3/4 thrombocytopenia had received significantly higher radiation doses to RM than patients with grade 1/2 thrombocytopenia (P = 0.02). A surrogate, non-imaging-based, method underestimated the RM dose and did not show any correlation with toxicity. Predosing with lilotomab reduces the RM-absorbed dose for 177 Lu-lilotomab satetraxetan patients. The decrease in RM dose could be explained by the lower volume of distribution. Hematologic toxicity was more severe for patients

Adaptive back-stepping control of the harmonic drive system with LuGre model-based friction compensation

NASA Astrophysics Data System (ADS)

Liu, Sen; Gang, Tieqiang

2018-03-01

Harmonic drives are widely used in aerospace and industrial robots. Flexibility, friction and parameter uncertainty will result in transmission performance degradation. In this paper, an adaptive back-stepping method with friction compensation is proposed to improve the tracking performance of the harmonic drive system. The nonlinear friction is described by LuGre model and compensated with a friction observer, and the uncertainty of model parameters is resolved by adaptive parameter estimation method. By using Lyapunov stability theory, it is proved that all the errors of the closed-loop system are uniformly ultimately bounded. Simulations illustrate the effectiveness of our friction compensation method.

Tungsten ditelluride for a nanosecond Ho,Pr:LiLuF4 laser at 2.95 µm

NASA Astrophysics Data System (ADS)

Yan, Zhengyu; Li, Tao; Zhao, Jia; Zhao, Shengzhi; Yang, Kejian; Li, Guiqiu; Li, Dechun; Zhang, Shuaiyi; Li, Jian

2018-04-01

The linear and nonlinear absorption characteristics of a home-built multilayer tungsten ditelluride (WTe2) saturable absorber at ~3 µm were demonstrated for the first time. A passively Q-switched Ho,Pr:LiLuF4 laser was realized by inserting the WTe2-saturable absorber into a plane-concave laser cavity. A maximum average output power of 128 mW, with a pulse duration of 366 ns at a repetition rate of 92 kHz was obtained under an absorbed pump power of 3.67 W, corresponding to a pulse energy of 1.4 µJ.

Diode-pumped continuous-wave and passively Q-switched Nd:GdLuAG laser at 1443.9 nm

NASA Astrophysics Data System (ADS)

Wu, Qianwen; Liu, Zhaojun; Zhang, Sasa; Cong, Zhenghua; Guan, Chen; Xue, Feng; Chen, Hui; Huang, Qingjie; Xu, Xiaodong; Xu, Jun; Qin, Zengguang

2017-12-01

We investigated the 1443.9 nm laser characteristics of Nd:GdLuAG crystal. Diode-end-pumping configuration was employed under both continuous-wave (CW) and passively Q-switched operations. For CW operation, the maximum average output power was 1.36 W with a slope efficiency of 15%. By using a V3+:YAG crystal as the saturable absorber, we obtained the maximum average output power of 164 mW under Q-switched operation. The corresponding pulse energy was 29.3 μJ and pulse duration was 59 ns.

Electronic and structural properties of Lu under pressure: Relation to structural phases of the rare-earth metals

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

Min, B.I.; Oguchi, T.; Jansen, H.J.F.

1986-07-15

Ground-state electronic and structural properties of Lu under pressure are investigated with use of the self-consistent all-electron total-energy linear muffin-tin orbital band-structure method within a local-density-functional approximation. Pressure-induced structural transitions are found to occur in the following sequence: hcp--(Sm-type)--dhcp--fcc, which is the same as that observed in the crystal structures of the trivalent rare-earth metals with decreasing atomic number. This structural transition is correlated with the increase in the number of d-italic electrons under pressure.

[Luís Gomes Ferreira reports on the health of slaves in his work entitled Erário mineral (1735)].

PubMed

Eugênio, Alisson

2015-01-01

The article analyzes the reports of Luís Gomes Ferreira published in his manual on practical medicine entitled Erário mineral, of 1735, on the most common illnesses in captivity. It is shown that such reports can be interpreted as a criticism of the social relations of the slave era by issuing some warnings to the landowners who failed to look after the health of their slaves.

Re-Os and Lu-Hf isotopic constraints on the formation and age of mantle pyroxenites from the Bohemian Massif

NASA Astrophysics Data System (ADS)

Ackerman, Lukáš; Bizimis, Michael; Haluzová, Eva; Sláma, Jiří; Svojtka, Martin; Hirajima, Takao; Erban, Vojtěch

2016-07-01

We report on the Lu-Hf and Re-Os isotope systematics of a well-characterized suite of spinel and garnet pyroxenites from the Gföhl Unit of the Bohemian Massif (Czech Republic, Austria). Lu-Hf mineral isochrons of three pyroxenites yield undistinguishable values in the range of 336-338 Ma. Similarly, the slope of Re-Os regression for most samples yields an age of 327 ± 31 Ma. These values overlap previously reported Sm-Nd ages on pyroxenites, eclogites and associated peridotites from the Gföhl Unit, suggesting contemporaneous evolution of all these HT-HP rocks. The whole-rock Hf isotopic compositions are highly variable with initial εHf values ranging from - 6.4 to + 66. Most samples show a negative correlation between bulk rock Sm/Hf and εHf and, when taking into account other characteristics (e.g., high 87Sr/86Sr), this may be explained by the presence of recycled oceanic sediments in the source of the pyroxenite parental melts. A pyroxenite from Horní Kounice has decoupled Hf-Nd systematics with highly radiogenic initial εHf of + 66 for a given εNd of + 7.8. This decoupling is consistent with the presence of a melt derived from a depleted mantle component with high Lu/Hf. Finally, one sample from Bečváry plots close to the MORB field in Hf-Nd isotope space consistent with its previously proposed origin as metamorphosed oceanic gabbro. Some of the websterites and thin-layered pyroxenites have variable, but high Os concentrations paralleled by low initial γOs. This reflects the interaction of the parental pyroxenitic melts with a depleted peridotite wall rock. In turn, the radiogenic Os isotope compositions observed in most pyroxenite samples is best explained by mixing between unradiogenic Os derived from peridotites and a low-Os sedimentary precursor with highly radiogenic 187Os/188Os. Steep increase of 187Os/188Os at nearly uniform 187Re/188Os found in a few pyroxenites may be connected with the absence of primary sulfides, but the presence of minor

Optical spectroscopic study of multiferroic BiFeO3 and LuFe2O4

NASA Astrophysics Data System (ADS)

Xu, Xiaoshan

2010-03-01

Iron-based multiferroics such as BiFeO3 and LuFe2O4 exhibit the highest magnetic and ferroelectric ordering temperatures among known multiferroics. LuFe2O4 is a frustrated system with several phase transitions that result in electronically driven multiferroicity. To understand how this peculiar multiferroic mechanism correlates with magnetism, we studied electronic excitations by optical spectroscopy and other complementary techniques. We show that the charge order, which determines the dielectric properties, is due to the ``order by fluctuation'' mechanism, evidenced by the onset of charge fluctuation well below the charge ordering transition. We also find a low temperature monoclinic distortion driven by both temperature and magnetic field, indicating strong coupling between structure, magnetism and charge order. BiFeO3 is the only known single phase multiferroics with room temperature magnetism and ferroelectricity. To investigate the spin-charge coupling, we measured the optical properties of BiFeO3. We find that the absorption onset occurs due to on-site Fe^3+ excitations at 1.41 and 1.90 eV. Temperature and magnetic-field-induced spectral changes reveal complex interactions between on-site crystal-field and magnetic excitations in the form of magnon sidebands. The sensitivity of the magnon sidebands allows us to map out the magnetic-field temperature phase diagram which demonstrates optical evidence for spin spiral quenching above 20 T and suggests a spin domain reorientation near 10 T. Work done in collaboration with T.V. Brinzari, R.C. Rai, M. Angst, R.P. Hermann, A.D. Christianson, J.-W. Kim, Z. Islam, B.C. Sales, D. Mandrus, S. Lee, Y.H. Chu, L. W. Martin, A. Kumar, R. Ramesh, S.W. Cheong, S. McGill, and J.L. Musfeldt.

Radiosensitivity of Prostate Cancer Cell Lines for Irradiation from Beta Particle-emitting Radionuclide ¹⁷⁷Lu Compared to Alpha Particles and Gamma Rays.

PubMed

Elgqvist, Jörgen; Timmermand, Oskar Vilhelmsson; Larsson, Erik; Strand, Sven-Erik

2016-01-01

The purpose of the present study was to investigate the radiosensitivity of the prostate cancer cell lines LNCaP, DU145, and PC3 when irradiated with beta particles emitted from (177)Lu, and to compare the effect with irradiation using alpha particles or gamma rays. Cells were irradiated with beta particles emitted from (177)Lu, alpha particles from (241)Am, or gamma rays from (137)Cs. A non-specific polyclonal antibody was labeled with (177)Lu and used to irradiate cells in suspension with beta particles. A previously described in-house developed alpha-particle irradiator based on a (241)Am source was used to irradiate cells with alpha particles. External gamma-ray irradiation was achieved using a standard (137)Cs irradiator. Cells were irradiated to absorbed doses equal to 0, 0.5, 1, 2, 4, 6, 8, or 10 Gy. The absorbed doses were calculated as mean absorbed doses. For evaluation of cell survival, the tetrazolium-based WST-1 assay was used. After irradiation, WST-1 was added to the cell solutions, incubated, and then measured for level of absorbance at 450 nm, indicating the live and viable cells. LNCaP, DU145, and PC3 cell lines all had similar patterns of survival for the different radiation types. No significant difference in surviving fractions were observed between cells treated with beta-particle and gamma-ray irradiation, represented for example by the surviving fraction values (mean±SD) at 2, 6, and 10 Gy (SF2, SF6, and SF10) for DU145 after beta-particle irradiation: 0.700±0.090, 0.186±0.050 and 0.056±0.010, respectively. A strong radiosensitivity to alpha particles was observed, with SF2 values of 0.048±0.008, 0.018±0.006 and 0.015±0.005 for LNCaP, DU145, and PC3, respectively. The surviving fractions after irradiation using beta particles or gamma rays did not differ significantly at the absorbed dose levels and dose rates used. Irradiation using alpha particles led to a high level of cell killing. The results show that the beta-particle emitter

Luminescence and scintillation properties of XPO4:Nd3+ (X = Y, Lu, Sc, La) crystals

NASA Astrophysics Data System (ADS)

Makowski, Michał; Witkowski, Marcin E.; Drozdowski, Winicjusz; Wojtowicz, Andrzej J.; Wisniewski, Krzysztof; Boatner, Lynn A.

2018-05-01

Due to their very fast short-wavelength emission, neodymium-doped materials are a subject of current interest as potential scintillators. Although the initial reports regarding neodymium-doped orthophosphates (in crystalline form) and their scintillation properties appeared almost twenty years ago, they remain an interesting class of materials since there is no in-depth understanding of their fundamental scintillation mechanism. In the present research, we focus on the crystalline systems: XPO4:Nd3+, where X = Y, Lu, La, Sc. The pulse height, optical absorption, radioluminescence and photoluminescence spectra were investigated and are reported here for various temperatures from 10 to 350 K. Additionally, results of both low and high temperature thermoluminescence measurements are reported in this communication.

Facile hydrothermal crystallization of NaLn(WO4)2 (Ln=La-Lu, and Y), phase/morphology evolution, and photoluminescence

NASA Astrophysics Data System (ADS)

Shi, Xiaofei; Li, Ji-Guang; Wang, Xuejiao; Zhu, Qi; Kim, Byung-Nam; Sun, Xudong

2017-12-01

Hydrothermal reaction of Ln nitrate and Na2WO4 at pH=8 and 200 °C for 24 hours, in the absence of any additive, has directly produced the scheelite-type sodium lanthanide tungstate of NaLn(WO4)2 for the larger Ln3+ of Ln=La-Dy (including Y, Group I) and an unknown compound that can be transformed into NaLn(WO4)2 by calcination at the low temperature of 600 °C for the smaller Ln3+ of Ln=Ho-Lu (Group II). With the successful synthesis of NaLn(WO4)2 for the full spectrum of Ln, the effects of lanthanide contraction on the structural features, crystal morphology, and IR responses of the compounds were clarified. The temperature- and time-course phase/morphology evolutions and the phase conversion upon calcination were thoroughly studied for the Group I and Group II compounds with Ln=La and Lu for example, respectively. Unknown intermediates were characterized by elemental analysis, IR absorption, thermogravimetry, and differential scanning calorimetry to better understand their chemical composition and coordination. The photoluminescence properties of NaEu(WO4)2 and NaTb(WO4)2, including excitation, emission, fluorescence decay, and quantum efficiency of luminescence, were also comparatively studied for the as-synthesized and calcination products.

Efficient laser operation of Nd3+:Lu2O3 at various wavelengths between 917 nm and 1463 nm

NASA Astrophysics Data System (ADS)

von Brunn, P.; Heuer, A. M.; Fornasiero, L.; Huber, G.; Kränkel, C.

2016-08-01

Even though the first Nd3+-doped sesquioxide lasers have been realized more than 50 years ago, up to now no reports on efficient laser operation of Nd3+:doped sesquioxides can be found. In this work, we review the favorable spectroscopic properties of the sesquioxide Nd3+:Lu2O3 in terms of ground state absorption, stimulated emission, and excited state absorption cross sections as well as the upper level lifetime. Making use of these properties, we achieved efficient laser performance on eight different laser transitions in the wavelength range between 917 nm and 1463 nm under Ti:sapphire laser pumping using state-of-the-art HEM-grown Nd3+:Lu2O3 crystals with good optical quality. At the strongest transition around 1076 nm we determined a slope efficiency of 69%, which represents the highest efficiency ever obtained for a Nd3+-doped sesquioxide. Furthermore, we could generate watt level output powers and high slope efficiencies for seven other transitions. Lasers at 917 nm, 1053 nm, 1108 nm and 1463 nm were realized for the first time and the latter represents one of the longest laser wavelengths obtained on the 4F3/2  →  4I13/2 transition in Nd3+-doped materials.

Investigation of the magnetic properties in double perovskite R2CoMnO6 single crystals (R  =  rare earth: La to Lu).

PubMed

Kim, M K; Moon, J Y; Choi, H Y; Oh, S H; Lee, N; Choi, Y J

2015-10-28

We have successfully synthesized the series of the double-perovskite R2CoMnO6 (R  =  rare earth: La to Lu) single crystals and have investigated their magnetic properties. The ferromagnetic order of Co(2+)/Mn(4+) spins emerges mainly along the c axis. Upon decreasing the size of rare earth ion, the magnetic transition temperature decreases linearly from 204 K for La2CoMnO6 to 48 K for Lu2CoMnO6, along with the enhancement of monoclinic distortion. The temperature and magnetic-field dependences of magnetization reveal the various magnetic characteristics such as the metamagnetic transition in R  =  Eu, the isotropic nature of rare earth moment in R  =  Gd, and the reversal of magnetic anisotropy in R  =  Tb and Dy. Our results offer comprehensive information for understanding the roles of mixed-valent magnetic ions and rare earth magnetic moments on the magnetic properties.

Activation cross-sections of proton induced reactions on natHf in the 38-65 MeV energy range: Production of 172Lu and of 169Yb

NASA Astrophysics Data System (ADS)

Tárkányi, F.; Hermanne, A.; Ditrói, F.; Takács, S.; Ignatyuk, A. V.

2018-07-01

In the frame of a systematical study of light ion induced nuclear reactions on hafnium, activation cross sections for proton induced reactions were investigated. Excitation functions were measured in the 38-65 MeV energy range for the natHf(p,xn)180g,177,176,175,173Ta, natHf(p,x)180m,179m,175,173,172,171Hf, 177g,173,172,171,170,169Lu and natHf(p,x)169Yb reactions by using the activation method, combining stacked foil irradiation and off line gamma ray spectroscopy. The experimental results are compared with earlier results in the overlapping energy range, and with the theoretical predictions of the ALICE IPPE and EMPIRE theoretical codes and of the TALYS code reported in the TENDL-2015 and TENDL-2017 libraries. The production routes of 172Lu (and its parent 172Hf) and of 169Yb are reviewed.

Manifestations neuropsychiatriques révélant une hémorragie cérébro-méningée causée par un accident d’électrisation: à propos d'une observation et revue de la literature

PubMed Central

Bugeme, Marcellin; Mukuku, Olivier

2014-01-01

Le courant électrique est susceptible de léser tout tissu de l'organisme rencontré lors de son passage, de manière transitoire ou définitive. Les hémorragies cérébro-méningées secondaires à un accident d’électrisation par courant électrique à haute tension sont très rarement rapportées dans la littérature. Nous rapportons un cas d'hémorragie cérébro-méningée révélée par des manifestations neuropsychiatriques causée par un AE par courant électrique à haute tension observée chez un enfant âgé de 6 ans à Lubumbashi, en République Démocratique du Congo. La particularité que présente notre observation est les manifestations neuropsychiatriques observées tardivement. PMID:25419328

Frustrated spin- 1 2 molecular magnetism in the mixed-valence antiferromagnets Ba 3 M Ru 2 O 9 ( M = In , Y, Lu)

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

Ziat, D.; Aczel, Adam A.; Sinclair, R.

We have performed magnetic susceptibility, heat capacity, muon spin relaxation, and neutron-scattering measurements on three members of the family Ba 3MRu 2O 9, where M=In, Y, and Lu. These systems consist of mixed-valence Ru dimers on a triangular lattice with antiferromagnetic interdimer exchange. Although previous work has argued that charge order within the dimers or intradimer double exchange plays an important role in determining the magnetic properties, our results suggest that the dimers are better described as molecular units due to significant orbital hybridization, resulting in one spin-1/2 moment distributed equally over the two Ru sites. These molecular building blocksmore » form a frustrated, quasi-two-dimensional triangular lattice. Our zero- and longitudinal-field μSR results indicate that the molecular moments develop a collective, static magnetic ground state, with oscillations of the zero-field muon spin polarization indicative of long-range magnetic order in the Lu sample. In conclusion, the static magnetism is much more disordered in the Y and In samples, but they do not appear to be conventional spin glasses.« less

Frustrated spin- 1 2 molecular magnetism in the mixed-valence antiferromagnets Ba 3 M Ru 2 O 9 ( M = In , Y, Lu)

DOE PAGES

Ziat, D.; Aczel, Adam A.; Sinclair, R.; ...

2017-05-22

We have performed magnetic susceptibility, heat capacity, muon spin relaxation, and neutron-scattering measurements on three members of the family Ba 3MRu 2O 9, where M=In, Y, and Lu. These systems consist of mixed-valence Ru dimers on a triangular lattice with antiferromagnetic interdimer exchange. Although previous work has argued that charge order within the dimers or intradimer double exchange plays an important role in determining the magnetic properties, our results suggest that the dimers are better described as molecular units due to significant orbital hybridization, resulting in one spin-1/2 moment distributed equally over the two Ru sites. These molecular building blocksmore » form a frustrated, quasi-two-dimensional triangular lattice. Our zero- and longitudinal-field μSR results indicate that the molecular moments develop a collective, static magnetic ground state, with oscillations of the zero-field muon spin polarization indicative of long-range magnetic order in the Lu sample. In conclusion, the static magnetism is much more disordered in the Y and In samples, but they do not appear to be conventional spin glasses.« less

Growth and characterization of single crystal rocksalt LaAs using LuAs barrier layers

NASA Astrophysics Data System (ADS)

Krivoy, E. M.; Rahimi, S.; Nair, H. P.; Salas, R.; Maddox, S. J.; Ironside, D. J.; Jiang, Y.; Dasika, V. D.; Ferrer, D. A.; Kelp, G.; Shvets, G.; Akinwande, D.; Bank, S. R.

2012-11-01

We demonstrate the growth of high-quality, single crystal, rocksalt LaAs on III-V substrates; employing thin well-behaved LuAs barriers layers at the III-V/LaAs interfaces to suppress nucleation of other LaAs phases, interfacial reactions between GaAs and LaAs, and polycrystalline LaAs growth. This method enables growth of single crystal epitaxial rocksalt LaAs with enhanced structural and electrical properties. Temperature-dependent resistivity and optical reflectivity measurements suggest that epitaxial LaAs is semimetallic, consistent with bandstructure calculations in literature. LaAs exhibits distinct electrical and optical properties, as compared with previously reported rare-earth arsenide materials, with a room-temperature resistivity of ˜459 μΩ-cm and an optical transmission window >50% between ˜3-5 μm.

Influence of annealing temperature on structural and optical properties of Lu{sub 2}O{sub 3}:Eu{sup 3+}, Tb{sup 3+} transparent films

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

Morales-Ramírez, Ángel de Jesús; García-Murillo, Antonieta, E-mail: angarciam@ipn.mx; Carrillo-Romo, Felipe de Jesús

2015-10-15

Highlights: • Lu{sub 2}O{sub 3}:Eu{sup 3+}, Tb{sup 3+} films were synthesized by sol–gel and by dip-coating technique. • Effects of annealing treatment on structural and optical properties were studied. • Optogeometrical characteristics of synthesized films were analyzed. • X-ray diffraction results showed that Lu{sub 2}O{sub 3}:Eu{sup 3+}, Tb{sup 3+} crystallizes at 700 °C. • High reddish emission on transparent films with at least 1 μm thick was observed. - Abstract: High-optical quality Lu{sub 2}O{sub 3}:Eu{sup 3+} 5 mol%, X Tb{sup 3+} (X = 0–0.04 mol%) thin films were prepared by the sol–gel process and dip-coating technique. The procedure was asmore » follows: lutetium, europium and terbium nitrates were used as precursors, and ethanol as a solvent. Etylenglycol (EG) was added as a sol stabilizer, and the pH was adjusted by acetic acid. After 10 dipping-cycles, followed by an annealing process (600–900 °C) for 1 h, transparent, smooth and crack-free films (ra = 8–9 nm) were formed. The X-ray diffraction (XRD) results showed crystallized films into the cubic structure at 800 °C. The ellipsometry results showed that the thickness of the films varied from 1 to 1.4 μm at 1000 and 600 °C, respectively. Finally, the films presented a typical Eu{sup 3+} red emission at 611 nm ({sup 5}D{sub 0} → {sup 7}F{sub 2}); furthermore, the effect of the Tb{sup 3+} content showed that the highest emission intensity corresponded to the lower Tb{sup 3+} content.« less

Structural and Luminescence Properties of Lu2O3:Eu3+ F127 Tri-Block Copolymer Modified Thin Films Prepared by Sol-Gel Method

PubMed Central

de Jesus Morales Ramírez, Angel; Hernández, Margarita García; Murillo, Antonieta García; de Jesús Carrillo Romo, Felipe; Palmerin, Joel Moreno; Velazquez, Dulce Yolotzin Medina; Jota, María Luz Carrera

2013-01-01

Lu2O3:Eu3+ transparent, high density, and optical quality thin films were prepared using the sol-gel dip-coating technique, starting with lutetium and europium nitrates as precursors and followed by hydrolysis in an ethanol-ethylene glycol solution. Acetic acid and acetylacetonate were incorporated in order to adjust pH and as a sol stabilizer. In order to increment the thickness of the films and orient the structure, F127 Pluronic acid was incorporated during the sol formation. Structural, morphological, and optical properties of the films were investigated for different F127/Lu molar ratios (0–5) in order to obtain high optical quality films with enhanced thickness compared with the traditional method. X-ray diffraction (XRD) shows that the films present a highly oriented cubic structure <111> beyond 1073 K for a 3-layer film, on silica glass substrates. The thickness, density, porosity, and refractive index evolution of the films were investigated by means of m-lines microscopy along with the morphology by scanning electron microscope (SEM) and luminescent properties. PMID:28809336

Luminescence and scintillation properties of XPO 4:Nd 3+ (X = Y, Lu, Sc, La) crystals

DOE PAGES

Makowski, Michal; Witkowski, Marcin E.; Drozdowski, Winicjusz; ...

2018-04-12

Due to their very fast short-wavelength emission, neodymium-doped materials are a subject of current interest as potential scintillators. Although the initial reports regarding neodymium-doped orthophosphates (in crystalline form) and their scintillation properties appeared almost twenty years ago, they remain an interesting class of materials since there is no in-depth understanding of their fundamental scintillation mechanism. In the present research, we focus on the crystalline systems: XPO 4:Nd 3+, where X = Y, Lu, La, Sc. The pulse height, optical absorption, radioluminescence and photoluminescence spectra were investigated and are reported here for various temperatures from 10 to 350 K. Here, resultsmore » of both low and high temperature thermoluminescence measurements are reported in this communication.« less

Assessment of cell death mechanisms triggered by 177Lu-anti-CD20 in lymphoma cells.

PubMed

Azorín-Vega, E; Rojas-Calderón, E; Martínez-Ventura, B; Ramos-Bernal, J; Serrano-Espinoza, L; Jiménez-Mancilla, N; Ordaz-Rosado, D; Ferro-Flores, G

2018-08-01

The aim of this research was to evaluate the cell cycle redistribution and activation of early and late apoptotic pathways in lymphoma cells after treatment with 177 Lu-anti-CD20. Experimental and computer models were used to calculate the radiation absorbed dose to cancer cell nuclei. The computer model (Monte Carlo, PENELOPE) consisted of twenty spheres representing cells with an inner sphere (cell nucleus) embedded in culture media. Radiation emissions of the radiopharmaceutical located in cell membranes and in culture media were considered for nuclei dose calculations. Flow cytometric analyses demonstrated that doses as low as 4.8Gy are enough to induce cell cycle arrest and activate late apoptotic pathways. Copyright © 2017 Elsevier Ltd. All rights reserved.

Luminescence and scintillation properties of XPO 4:Nd 3+ (X = Y, Lu, Sc, La) crystals

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

Makowski, Michal; Witkowski, Marcin E.; Drozdowski, Winicjusz

Due to their very fast short-wavelength emission, neodymium-doped materials are a subject of current interest as potential scintillators. Although the initial reports regarding neodymium-doped orthophosphates (in crystalline form) and their scintillation properties appeared almost twenty years ago, they remain an interesting class of materials since there is no in-depth understanding of their fundamental scintillation mechanism. In the present research, we focus on the crystalline systems: XPO 4:Nd 3+, where X = Y, Lu, La, Sc. The pulse height, optical absorption, radioluminescence and photoluminescence spectra were investigated and are reported here for various temperatures from 10 to 350 K. Here, resultsmore » of both low and high temperature thermoluminescence measurements are reported in this communication.« less

Adaptive robust motion trajectory tracking control of pneumatic cylinders with LuGre model-based friction compensation

NASA Astrophysics Data System (ADS)

Meng, Deyuan; Tao, Guoliang; Liu, Hao; Zhu, Xiaocong

2014-07-01

Friction compensation is particularly important for motion trajectory tracking control of pneumatic cylinders at low speed movement. However, most of the existing model-based friction compensation schemes use simple classical models, which are not enough to address applications with high-accuracy position requirements. Furthermore, the friction force in the cylinder is time-varying, and there exist rather severe unmodelled dynamics and unknown disturbances in the pneumatic system. To deal with these problems effectively, an adaptive robust controller with LuGre model-based dynamic friction compensation is constructed. The proposed controller employs on-line recursive least squares estimation (RLSE) to reduce the extent of parametric uncertainties, and utilizes the sliding mode control method to attenuate the effects of parameter estimation errors, unmodelled dynamics and disturbances. In addition, in order to realize LuGre model-based friction compensation, the modified dual-observer structure for estimating immeasurable friction internal state is developed. Therefore, a prescribed motion tracking transient performance and final tracking accuracy can be guaranteed. Since the system model uncertainties are unmatched, the recursive backstepping design technology is applied. In order to solve the conflicts between the sliding mode control design and the adaptive control design, the projection mapping is used to condition the RLSE algorithm so that the parameter estimates are kept within a known bounded convex set. Finally, the proposed controller is tested for tracking sinusoidal trajectories and smooth square trajectory under different loads and sudden disturbance. The testing results demonstrate that the achievable performance of the proposed controller is excellent and is much better than most other studies in literature. Especially when a 0.5 Hz sinusoidal trajectory is tracked, the maximum tracking error is 0.96 mm and the average tracking error is 0.45 mm. This

Combined pressure-thermal inactivation effect on spores in lu-wei beef--a traditional Chinese meat product.

PubMed

Wang, B-S; Li, B-S; Du, J-Z; Zeng, Q-X

2015-08-01

This study investigated the inactivation effect and kinetics of Bacillus coagulans and Geobacillus stearothermophilus spores suspended in lu-wei beef by combining high pressure (500 and 600 MPa) and moderate heat (70 and 80 °C or 80 and 90 °C). During pressurization, the temperature of pressure-transmitting fluid was tested with a K-type thermocouple, and the number of surviving cells was determined by a plate count method. The pressure come-up time and corresponding inactivation of Bacillus coagulans and G. stearothermophilus spores were considered during the pressure-thermal treatment. For the two types of spores, the results showed a higher inactivation effect in phosphate buffer solution than that in lu-wei beef. Among the bacteria evaluated, G. stearothermophilus spores had a higher resistance than B. coagulans spores during the pressure-thermal processing. One linear model and two nonlinear models (i.e. the Weibull and log-logistic models) were fitted to the survivor data to obtain relevant kinetic parameters, and the performance of these models was compared. The results suggested that the survival curve of the spores could be accurately described utilizing the log-logistic model, which produced the best fit for all inactivation data. The compression heating characteristics of different pressure-transmitting fluids should be considered when using high pressure to sterilize spores, particularly while the pressure is increasing. Spores can be inactivated by combining high pressure and moderate heat. The study demonstrates the synergistic inactivation effect of moderate heat in combination with high pressure in real-life food. The use of mathematical models to predict the inactivation for spores could help the food industry further to develop optimum process conditions. © 2015 The Society for Applied Microbiology.

Krypton ion irradiation-induced amorphization and nano-crystal formation in pyrochlore Lu2Ti2O7 at room temperature

NASA Astrophysics Data System (ADS)

Xie, Qiu-Rong; Zhang, Jian; Yin, Dong-Min; Guo, Qi-Xun; Li, Ning

2015-12-01

Polycrystalline pyrochlore Lu2Ti2O7 pellets are irradiated with 600-keV Kr3+ ions up to a fluence of 1.45 × 1016 Kr3+/cm2. Irradiation induced structural modifications are examined by using grazing incidence x-ray diffraction (GIXRD) and cross-sectional transmission electron microscopy (TEM). The GIXRD reveals that amorphous fraction increases with the increase of fluences up to 2 × 1015 Kr3+/cm2, and the results are explained with a direct-impact model. However, when the irradiation fluence is higher than 2 × 1015 Kr3+/cm2, the amorphous fraction reaches a saturation of ∼80%. Further TEM observations imply that nano-crystal is formed with a diameter of ∼10 nm within the irradiation layer at a fluence of 4 × 1015 Kr3+/cm2. No full amorphization is achieved even at the highest fluence of 1.45 × 1016 Kr3+/cm2 (∼36 displacement per atom). The high irradiation resistance of pyrochlore Lu2Ti2O7 at higher fluence is explained on the basis of enhanced radiation tolerance of nano-crystal structure. Project sponsored by the National Natural Science Foundation of China (Grant No. 11205128) and the Fundamental Research Funds for the Central Universities, China (Grant No. 2012121034).

PEGylated NaLuF4: Yb/Er upconversion nanophosphors for in vivo synergistic fluorescence/X-ray bioimaging and long-lasting, real-time tracking.

PubMed

Yi, Zhigao; Lu, Wei; Xu, Yaru; Yang, Jing; Deng, Li; Qian, Chao; Zeng, Tianmei; Wang, Haibo; Rao, Ling; Liu, Hongrong; Zeng, Songjun

2014-12-01

Simultaneous in vivo luminescence and X-ray bioimaging in a tissue or animal integrates the advantages of each single-modal imaging technology, and will find widespread application in biological and clinical fields. However, synergistic dual-modal bioimaging that utilizes a new generation of upconversion nanoprobes is still limited. In addition, investigations concentrated on in vivo biodistribution of these nanoprobes may contribute to diagnosis and treatment, but long-term in vivo tracking based on these nanoprobes is rarely reported. In this work, water-soluble NaLuF4: Yb/Er nanophosphors were prepared through modified one-pot simultaneous synthesis and surface modification method. Owing to the outstanding upconverting emissions and large X-ray absorption coefficient/K-edge value of Lu and doped Yb ions, the obtained nanoprobes were successfully used as luminescent nanoprobes and X-ray contrast agents for in vivo synergistic upconversion luminescence and X-ray bioimaging. The in vivo biodistribution of these nanoprobes were observed, and the results based on long-term tracking reveal that the as-prepared nanoprobes first aggregated in the lung of the mouse, transferred to the liver, and finally moved to the spleen. Copyright © 2014 Elsevier Ltd. All rights reserved.

The influence of charge and magnetic order on polaron and acoustic phonon dynamics in LuFe 2O 4

DOE PAGES

Lee, J.; Trugman, S. A.; Zhang, C. L.; ...

2015-07-27

Femtosecond optical pump-probe spectroscopy is used to reveal the influence of charge and magnetic order on polarondynamics and coherent acoustic phonon oscillations in single crystals of charge-ordered, ferrimagnetic LuFe 2O 4. We experimentally observed the influence of magnetic order on polarondynamics. We also observed a correlation between charge order and the amplitude of the acoustic phonon oscillations, due to photoinduced changes in the lattice constant that originate from the photoexcited electrons. As a result, this provides insight into the general behavior of coherent acoustic phonon oscillations in charge-ordered materials.

Electron paramagnetic resonance of Cr{sup 3+} ions in ABO{sub 3} (A = Sc, Lu, In) diamagnetic crystals

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

Vorotynov, A. M., E-mail: sasa@iph.krasn.ru; Ovchinnikov, S. G.; Rudenko, V. V.

2016-04-15

A magnetic resonance method is applied to the investigation of a number of isostructural diamagnetic compounds ABO{sub 3} (A = Sc, Lu, In) with small additions of Cr{sup 3+} ions (S = 3/2) sufficient to observe single-ion spectra. It is shown that the resonance spectra for isolated Cr{sup 3+} ions can be described to a good accuracy by the ordinary axial spin Hamiltonian for 3d ions in octahedral oxygen environment. The parameters of the spin Hamiltonian are determined. It is established that Cr{sup 3+} ions in these crystals are characterized by easy-axis-type anisotropy.

Monte Carlo simulation of radiation transport and dose deposition from locally released gold nanoparticles labeled with 111In, 177Lu or 90Y incorporated into tissue implantable depots

NASA Astrophysics Data System (ADS)

Lai, Priscilla; Cai, Zhongli; Pignol, Jean-Philippe; Lechtman, Eli; Mashouf, Shahram; Lu, Yijie; Winnik, Mitchell A.; Jaffray, David A.; Reilly, Raymond M.

2017-11-01

Permanent seed implantation (PSI) brachytherapy is a highly conformal form of radiation therapy but is challenged with dose inhomogeneity due to its utilization of low energy radiation sources. Gold nanoparticles (AuNP) conjugated with electron emitting radionuclides have recently been developed as a novel form of brachytherapy and can aid in homogenizing dose through physical distribution of radiolabeled AuNP when injected intratumorally (IT) in suspension. However, the distribution is unpredictable and precise placement of many injections would be difficult. Previously, we reported the design of a nanoparticle depot (NPD) that can be implanted using PSI techniques and which facilitates controlled release of AuNP. We report here the 3D dose distribution resulting from a NPD incorporating AuNP labeled with electron emitters (90Y, 177Lu, 111In) of different energies using Monte Carlo based voxel level dosimetry. The MCNP5 Monte Carlo radiation transport code was used to assess differences in dose distribution from simulated NPD and conventional brachytherapy sources, positioned in breast tissue simulating material. We further compare these dose distributions in mice bearing subcutaneous human breast cancer xenografts implanted with 177Lu-AuNP NPD, or injected IT with 177Lu-AuNP in suspension. The radioactivity distributions were derived from registered SPECT/CT images and time-dependent dose was estimated. Results demonstrated that the dose distribution from NPD reduced the maximum dose 3-fold when compared to conventional seeds. For simulated NPD, as well as NPD implanted in vivo, 90Y delivered the most homogeneous dose distribution. The tumor radioactivity in mice IT injected with 177Lu-AuNP redistributed while radioactivity in the NPD remained confined to the implant site. The dose distribution from radiolabeled AuNP NPD were predictable and concentric in contrast to IT injected radiolabeled AuNP, which provided irregular and temporally variant dose distributions

Radioimmunotherapy (RIT) Dose-Escalation Studies in Prostate Cancer Using Anti-PSMA Antibody 177Lu-J591: RIT Alone and RIT in Combination with Docetaxel

DTIC Science & Technology

2009-10-01

product consists of DOTA-HuJ591 antibody in 0.3 M ammonium acetate, pH 7.2, in 2 mL thermoplastic vials with gray butyl rubber stoppers and blue flip-off...crimp seal closures . The nominal concentration is 8.0 mg/mL and the nominal fill volume is 1.3 mL. There are no other excipients added. 177Lu

Molecular identification of Plasmodium spp. and blood meal sources of anophelines in environmental reserves on São Luís Island, state of Maranhão, Brazil.

PubMed

Figueiredo, Mayra Araguaia Pereira; Di Santi, Silvia Maria; Manrique, Wilson Gómez; Gonçalves, Luiz Ricardo; André, Marcos Rogério; Machado, Rosangela Zacarias

2017-04-26

Considering the diversity of feeding habits that females of some species of anophelines present, it is important to understand which vertebrates are part of blood food sources and how important is the role of each in the ecoepidemiology of malaria. There are many vector species for Plasmodium spp. in the State of Maranhão, Brazil. In São Luís Island, Anopheles aquasalis is the main vector for human malaria; this species is abundant in areas with primates that are positive for Plasmodium. Anopheles aquasalis has natural exophilic and zoophilic feeding behavior, but in cases of high density and absence of animals, presents quite varied behavior, and feeds on human blood. In this context, the objective of the present study was to identify Plasmodium spp. and the blood meal sources of anophelines in two environmental reserves on São Luís Island, state of Maranhão, using molecular methods. Between June and July 2013, female anophelines were collected in the Sítio Aguahy Private Reserve, in the municipality of São José de Ribamar, and in the Sítio Mangalho Reserve, located within the Maracanã Environmental Protection Area, in the municipality of São Luís. CDC-type light traps, Shannon traps and protected human bait were used during three consecutive hours in peridomestic and wooded areas. Pools of anophelines were formed using mosquitoes of the same species that had been caught at the same site on the same date. A genus-specific amplification protocol based on the 18S rRNA gene was used for qPCR and cPCR. A total of 416 anophelines were collected, of the following species: An. aquasalis (399), An. mediopunctatus (3), An. shannoni (1), An. nuneztovari (sensu lato) (1), An. goeldii (1), An. evansae (2) and An. (Nyssorhynchus) sp. (9), comprising 54 pools. Two pools were positive for Plasmodium (2/54) based on the 18S rRNA gene. In the phylogenetic analysis using the maximum likelihood method, based on a 240 bp fragment of the 18S rRNA gene, it was found that

Preclinical evaluation of a diabody-based (177)Lu-radioimmunoconjugate for CD22-directed radioimmunotherapy in a non-Hodgkin lymphoma mouse model.

PubMed

Weber, Tobias; Bötticher, Benedikt; Arndt, Michaela A E; Mier, Walter; Sauter, Max; Exner, Evelyn; Keller, Armin; Krämer, Susanne; Leotta, Karin; Wischnjow, Artjom; Grosse-Hovest, Ludger; Strumberg, Dirk; Jäger, Dirk; Gröne, Hermann-Josef; Haberkorn, Uwe; Brem, Gottfried; Krauss, Jürgen

2016-10-28

Radioimmunotherapy is considered as treatment option in recurrent and/or refractory B-cell non-Hodgkin lymphoma (B-NHL). To overcome the dose limiting bone marrow toxicity of IgG-based radioimmunoconjugates (RICs), we modified a humanized diabody with 5-, 10-, or 20-kDa polyethylene glycol (PEG) for CD22-targeted radioimmunotherapy using the low-energy β-emitter lutetium-177 ((177)Lu). A favorable pharmacokinetic profile was observed for the 10-kDa-PEG-diabody in nude mice being xenografted with subcutaneous human Burkitt lymphoma. Even at high doses of 16 MBq this diabody RIC was well tolerated by NOD Rag1(null) IL2rγ(null) (NRG) mice and did not reveal signs of organ long-term toxicity 80 days post injection. Combination therapy of the diabody RIC with unconjugated anti-CD20 Rituximab demonstrated therapeutic efficacy in established disseminated mantle cell lymphoma xenograft models. When compared with the combination of the IgG formatted (177)Lu anti-CD22 antibody and Rituximab, dual targeted therapy with the diabody RIC achieved an improved reduction of disease burden in the first nine days following treatment. The data indicate that the PEGylated anti-CD22 diabody may have potential for extending the repertoire of radiopharmaceuticals for the treatment of patients with B-NHL. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effect of pH value on structural and photoluminescence properties of Tb3+ -doped Lu2O3 nanopowders synthesized by sol-gel route

NASA Astrophysics Data System (ADS)

Mendoud, A.; Guerbous, L.; Boukerika, A.; Boudine, B.; Benrekaa, N.

2018-01-01

Tb3+-doped Lu2O3 nanophosphors were prepared via simple sol-gel method, at different pH value of solution (2, 5, 8 and 11), using diethanolamine (DEA) as polymerization agent. The nanopowder samples were characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, room temperature steady and time resolved photoluminescence spectroscopy. The structural analysis reveals that all samples mainely crystallized in the cubic bixbyite structure with Ia3 space group. Also, it was found that the pH value of solution strongly influences the crystallite size, the vibrational frequency modes and the surface morphology of Lu2O3:Tb3+ nanocrystals. All samples show blue-greenish emissions, corresponding to 5D4 → 7FJ (J = 3, 4, 5 and 6) intraconfigurationnelles transitions. The intense green emission peak situated at 542 nm is assigned to 5D4 → 7F5 transition. The 4f8 → 4f75d1 spin-allowed and forbidden transitions, the charge transfer band (CTB) O2- → Tb3+ and the host absorption bands were observed and their dependence on pH value is discussed.

Study of 57Fe Mössbauer effect in RFe 2Zn 20 ( R = Lu, Yb, Gd)

DOE PAGES

Bud’ko, Sergey L.; Kong, Tai; Ma, Xiaoming; ...

2015-08-04

In this document we report measurements of 57Fe Mössbauer spectra for RFe 2Zn 20 ( R = Lu, Yb, Gd) from ~ 4.5 K to room temperature. The obtained isomer shift values are very similar for all three compounds, their temperature dependence was analyzed within the Debye model and resulted in an estimate of the Debye temperatures of 450-500 K. The values of quadrupole splitting at room temperature change with the cubic lattice constant a in a linear fashion. For GdFe 2Zn 20, ferromagnetic order is seen as an appearance of a sextet in the spectra. The 57Fe site hyperfinemore » field for T → 0 was evaluated to be ~ 2.4 T.« less

Revised model core potentials for third-row transition-metal atoms from Lu to Hg

NASA Astrophysics Data System (ADS)

Mori, Hirotoshi; Ueno-Noto, Kaori; Osanai, You; Noro, Takeshi; Fujiwara, Takayuki; Klobukowski, Mariusz; Miyoshi, Eisaku

2009-07-01

We have produced new relativistic model core potentials (spdsMCPs) for the third-row transition-metal atoms from Lu to Hg explicitly treating explicitly 5s and 5p electrons in addition to 5d and 6s electrons in the same manner for the first- and second-row transition-metal atoms given in the previous Letters [Y. Osanai, M.S. Mon, T. Noro, H. Mori, H. Nakashima, M. Klobukowski, E. Miyoshi, Chem. Phys. Lett. 452 (2008) 210; Y. Osanai, E. Soejima, T. Noro, H. Mori, M.S. Mon, M. Klobukowski, E. Miyoshi, Chem. Phys. Lett. 463 (2008) 230]. Using suitable correlating functions with the split-valence MCP functions, we demonstrate that the present MCP basis sets show reasonable performance in describing the electronic structures of atoms and molecules, bringing about accurate excitation energies for atoms and proper spectroscopic constants for Au 2, Hg 2, and AuH.

Electronic structure of R Sb ( R = Y , Ce, Gd, Dy, Ho, Tm, Lu) studied by angle-resolved photoemission spectroscopy

DOE PAGES

Wu, Yun; Lee, Yongbin; Kong, Tai; ...

2017-07-15

Here, we use high-resolution angle-resolved photoemission spectroscopy (ARPES) and electronic structure calculations to study the electronic properties of rare-earth monoantimonides RSb (R = Y, Ce, Gd, Dy, Ho, Tm, Lu). The experimentally measured Fermi surface (FS) of RSb consists of at least two concentric hole pockets at the Γ point and two intersecting electron pockets at the X point. These data agree relatively well with the electronic structure calculations. Detailed photon energy dependence measurements using both synchrotron and laser ARPES systems indicate that there is at least one Fermi surface sheet with strong three-dimensionality centered at the Γ point. Duemore » to the “lanthanide contraction”, the unit cell of different rare-earth monoantimonides shrinks when changing the rare-earth ion from CeSb to LuSb. This results in the differences in the chemical potentials in these compounds, which are demonstrated by both ARPES measurements and electronic structure calculations. Interestingly, in CeSb, the intersecting electron pockets at the X point seem to be touching the valence bands, forming a fourfold-degenerate Dirac-like feature. On the other hand, the remaining rare-earth monoantimonides show significant gaps between the upper and lower bands at the X point. Furthermore, similar to the previously reported results of LaBi, a Dirac-like structure was observed at the Γ point in YSb, CeSb, and GdSb, compounds showing relatively high magnetoresistance. This Dirac-like structure may contribute to the unusually large magnetoresistance in these compounds.« less

Electronic structure of R Sb ( R = Y , Ce, Gd, Dy, Ho, Tm, Lu) studied by angle-resolved photoemission spectroscopy

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

Wu, Yun; Lee, Yongbin; Kong, Tai

Here, we use high-resolution angle-resolved photoemission spectroscopy (ARPES) and electronic structure calculations to study the electronic properties of rare-earth monoantimonides RSb (R = Y, Ce, Gd, Dy, Ho, Tm, Lu). The experimentally measured Fermi surface (FS) of RSb consists of at least two concentric hole pockets at the Γ point and two intersecting electron pockets at the X point. These data agree relatively well with the electronic structure calculations. Detailed photon energy dependence measurements using both synchrotron and laser ARPES systems indicate that there is at least one Fermi surface sheet with strong three-dimensionality centered at the Γ point. Duemore » to the “lanthanide contraction”, the unit cell of different rare-earth monoantimonides shrinks when changing the rare-earth ion from CeSb to LuSb. This results in the differences in the chemical potentials in these compounds, which are demonstrated by both ARPES measurements and electronic structure calculations. Interestingly, in CeSb, the intersecting electron pockets at the X point seem to be touching the valence bands, forming a fourfold-degenerate Dirac-like feature. On the other hand, the remaining rare-earth monoantimonides show significant gaps between the upper and lower bands at the X point. Furthermore, similar to the previously reported results of LaBi, a Dirac-like structure was observed at the Γ point in YSb, CeSb, and GdSb, compounds showing relatively high magnetoresistance. This Dirac-like structure may contribute to the unusually large magnetoresistance in these compounds.« less

Multiscale Modeling of Drug-induced Effects of ReDuNing Injection on Human Disease: From Drug Molecules to Clinical Symptoms of Disease

NASA Astrophysics Data System (ADS)

Luo, Fang; Gu, Jiangyong; Zhang, Xinzhuang; Chen, Lirong; Cao, Liang; Li, Na; Wang, Zhenzhong; Xiao, Wei; Xu, Xiaojie

2015-05-01

ReDuNing injection (RDN) is a patented traditional Chinese medicine, and the components of it were proven to have antiviral and important anti-inflammatory activities. Several reports showed that RDN had potential effects in the treatment of influenza and pneumonia. Though there were several experimental reports about RDN, the experimental results were not enough and complete due to that it was difficult to predict and verify the effect of RDN for a large number of human diseases. Here we employed multiscale model by integrating molecular docking, network pharmacology and the clinical symptoms information of diseases and explored the interaction mechanism of RDN on human diseases. Meanwhile, we analyzed the relation among the drug molecules, target proteins, biological pathways, human diseases and the clinical symptoms about it. Then we predicted potential active ingredients of RDN, the potential target proteins, the key pathways and related diseases. These attempts may offer several new insights to understand the pharmacological properties of RDN and provide benefit for its new clinical applications and research.

A Randomized Phase 2 Trial of 177Lu Radiolabeled Anti-PSMA Monoclonal Antibody J591in Patients with High-Risk Castrate, Biochemically Relapsed Prostate Cancer

DTIC Science & Technology

2012-09-01

micrometastases that may be targeted with radioimmunotherapy. Prostate specific membrane antigen (PSMA) is the single, most well-established, highly restricted...Radiolabeled anti- prostate specific membrane antigen (PSMA) monoclonal antibody J591 (177Lu-J591) for nonmetastatic castration-resistant prostate cancer...rationale for systemic salvage targeted anti- prostate specific membrane antigen radioimmunotherapy. Adv Urol 2012, Article ID 921674, doi:10.1155

Imbricatolic acid from Juniperus communis L. prevents cell cycle progression in CaLu-6 cells.

PubMed

De Marino, Simona; Cattaneo, Fabio; Festa, Carmen; Zollo, Franco; Iaccio, Annalisa; Ammendola, Rosario; Incollingo, Filomena; Iorizzi, Maria

2011-11-01

Imbricatolic acid was isolated from the methanolic extract of the fresh ripe berries of Juniperus communis (Cupressaceae) together with sixteen known compounds and a new dihydrobenzofuran lignan glycoside named juniperoside A. Their structures were determined by spectroscopic methods and by comparison with the spectral data reported in literature. Imbricatolic acid was evaluated for its ability to prevent cell cycle progression in p53-null CaLu-6 cells. This compound induces the upregulation of cyclin-dependent kinase inhibitors and their accumulation in the G1 phase of the cell cycle, as well as the degradation of cyclins A, D1, and E1. Furthermore, no significant imbricatolic acid-induced apoptosis was observed. Therefore, this plant-derived compound may play a role in the control of cell cycle. © Georg Thieme Verlag KG Stuttgart · New York.

940  mW 1564  nm multi-longitudinal-mode and 440  mW 1537  nm single-longitudinal-mode continuous-wave Er:Yb:Lu2Si2O7 microchip lasers.

PubMed

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

2018-04-15

An Er:Yb:Lu 2 Si 2 O 7 microchip laser was constructed by placing a 1.2 mm thick, Y-cut Er:Yb:Lu 2 Si 2 O 7 microchip between two 1.2 mm thick sapphire crystals, in which input and output mirrors were directly deposited onto one face of each crystal. End-pumped by a continuous-wave 975.4 nm diode laser, a 1564 nm multi-longitudinal-mode laser with a maximum output power of 940 mW and slope efficiency of 20% was realized at an absorbed pump power of 5.5 W when the transmission of output mirror was 2.2%. When the transmission of the output mirror was increased to 6%, a 1537 nm single-longitudinal-mode laser with a maximum output power of 440 mW and slope efficiency of 12% was realized at an absorbed pump power of 4.3 W. The results indicate that the Er:Yb:Lu 2 Si 2 O 7 crystal is a promising microchip gain medium to realize a single-longitudinal-mode laser.

Spherical Lu2O2S:Eu3+ micro/nano-structure: Controlled synthesis and luminescence properties

NASA Astrophysics Data System (ADS)

Zhang, Bowen; Zou, Haifeng; Dai, Yunzhi; Guan, Hongxia; Song, Yanhua; Zheng, Keyan; Zhou, Xiuqing; Shi, Zhan; Sheng, Ye

2017-02-01

Monodisperse and uniform Lu2O2S:Eu3+ luminescent spheres have been successfully synthesized through a facile hydrothermal method followed by a subsequent calcination process. The sizes of the spheres can be tuned in the range of 65 nm-295 nm by only changing the pH value of the system. It is indicated that the luminescence properties of the spherical phosphors were strongly influenced by size of the spheres. Such a size-sensitive luminescence property was interpreted from the structures of the spheres, including the degree of crystallinity, band gap energy, crystal field symmetry around Eu3+. We expected that this study not only can provide important information for size-controlled synthesis of spherical phosphors, but also can give a reference for exploration of size-dependent luminescence.

Natural Plasmodium infection in neotropical primates in the island of São Luís, state of Maranhão, Brazil.

PubMed

Figueiredo, Mayra Araguaia Pereira; Di Santi, Silvia Maria Fátima; Figueiredo, Thaysa Araguaia Pereira; Machado, Rosangela Zacarias

2015-01-01

The states that make up the Legal Amazon Region, which include the state of Maranhão, account for 99% of registered cases of human malaria in Brazil. It is also believed that transmission of malaria from nonhuman primates (NHP) to humans occurs in this region, because of current reports of seroepidemiological results from samples from humans and NHP coexisting in the same areas. This study aimed to make morphological, serological and molecular diagnoses of Plasmodium spp. in neotropical primates on the island of São Luís, state of Maranhão, Brazil. The diagnostic techniques used were optical microscopy, the polymerase chain reaction (PCR) and the indirect immunofluorescence assay (IFA). From June 2009 to April 2010, 70 NHP were sampled: 50 at the Wild Animal Screening Center (CETAS), located in the municipality of São Luís and 20 free-living individuals that were caught in a private reserve located in the municipality of São Jose de Ribamar, state of Maranhão. Under an optical microscope, 140 slides (two from each animal) were evaluated and five animals (7.1%) were found to be positive. IFA did not detect anti-Plasmodium spp. From PCR on the 70 animals sampled, amplified Plasmodium spp. products were observed in 13 samples, of which eight (61.5%) were from free-living animals and five (38.5%) were from animals at CETAS.

Tunable Optical Properties and Increased Thermal Quenching in the Blue-Emitting Phosphor Series: Ba 2 (Y 1–x Lu x ) 5 B 5 O 17 :Ce 3+ ( x = 0–1)

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

Hermus, Martin; Phan, Phu-Cuong; Duke, Anna C.

The preparation of cerium-substituted barium lutetium borate, Ba2Lu5B5O17:Ce3+, is achieved using high temperature solid state synthesis. This compound crystallizes in the Ba2Y5B5O17-type structure and shows an efficient blue emission (λmax = 447 nm) when excited by UV-light (λex = 340 nm) with a photoluminescent quantum yield near 90%, a fast luminescence decay time (<40 ns), and a thermal quenching temperature of 452 K. Further, preparing a solid solution following Ba2(Y1–xLux)5B5O17:Ce3+ (x = 0, 0.25, 0.50, 0.75, 1) confirms that all compounds are isostructural and follow Vegard’s law. Substituting Y3+ for Lu3+ yields a nearly constant emission spectrum that blue-shifts bymore » only 9 nm and has a consistent luminescence lifetime across the range prepared. The photoluminescent quantum yield (PLQY) and thermal quenching (T50) of the solid solution, however, are dramatically impacted by the composition, with the PLQY decreasing to ≈70% and the T50 dropping 49 K going from x = 1 to x = 0. These significant changes in the optical properties likely stem from enhanced structural rigidity as the larger, more polarizable Y3+ is substituted for the smaller, harder Lu3+ cation. These results highlight the importance of optimizing chemical bonding to improve a phosphor’s optical properties.« less

Absorbed dose estimates from a single measurement one to three days after the administration of 177Lu-DOTATATE/-TOC.

PubMed

Hänscheid, Heribert; Lapa, Constantin; Buck, Andreas K; Lassmann, Michael; Werner, Rudolf A

2017-01-01

To retrospectively analyze the accuracy of absorbed dose estimates from a single measurement of the activity concentrations in tumors and relevant organs one to three days after the administration of 177 Lu-DOTA-TATE/TOC assuming tissue specific effective half-lives. Activity kinetics in 54 kidneys, 30 neuroendocrine tumor lesions, 25 livers, and 27 spleens were deduced from series of planar images in 29 patients. After adaptation of mono- or bi-exponential fit functions to the measured data, it was analyzed for each fit function how precise the time integral can be estimated from fixed tissue-specific half-lives and a single measurement at 24, 48, or 72 h after the administration. For the kidneys, assuming a fixed tissue-specific half-life of 50 h, the deviations of the estimate from the actual integral were median (5 % percentile, 95 % percentile): -3 °% (-15 %>; +16 °%) for measurements after 24 h, +2 %> (-9 %>; +12 %>) for measurements after 48 h, and 0 % (-2 %; +12 %) for measurements after 72 h. The corresponding values for the other tissues, assuming fixed tissue-specific half-lives of 67 h for liver and spleen and 77 h for tumors, were +2 % (-25 %; +20 %) for measurements after 24 h, +2 °% (-16 %>; +17 %>) for measurements after 48 h, and +2 %> (-11 %>; +10 %>) for measurements after 72 h. Especially for the kidneys, which often represent the dose limiting organ, but also for liver, spleen, and neuroendocrine tumors, a meaningful absorbed dose estimate is possible from a single measurement after 2, more preferably 3 days after the administration of 177 Lu-DOTA-TATE/-TOC assuming fixed tissue specific effective half-lives. Schattauer GmbH.

Fast GPU-based Monte Carlo code for SPECT/CT reconstructions generates improved 177Lu images.

PubMed

Rydén, T; Heydorn Lagerlöf, J; Hemmingsson, J; Marin, I; Svensson, J; Båth, M; Gjertsson, P; Bernhardt, P

2018-01-04

Full Monte Carlo (MC)-based SPECT reconstructions have a strong potential for correcting for image degrading factors, but the reconstruction times are long. The objective of this study was to develop a highly parallel Monte Carlo code for fast, ordered subset expectation maximum (OSEM) reconstructions of SPECT/CT images. The MC code was written in the Compute Unified Device Architecture language for a computer with four graphics processing units (GPUs) (GeForce GTX Titan X, Nvidia, USA). This enabled simulations of parallel photon emissions from the voxels matrix (128 3 or 256 3 ). Each computed tomography (CT) number was converted to attenuation coefficients for photo absorption, coherent scattering, and incoherent scattering. For photon scattering, the deflection angle was determined by the differential scattering cross sections. An angular response function was developed and used to model the accepted angles for photon interaction with the crystal, and a detector scattering kernel was used for modeling the photon scattering in the detector. Predefined energy and spatial resolution kernels for the crystal were used. The MC code was implemented in the OSEM reconstruction of clinical and phantom 177 Lu SPECT/CT images. The Jaszczak image quality phantom was used to evaluate the performance of the MC reconstruction in comparison with attenuated corrected (AC) OSEM reconstructions and attenuated corrected OSEM reconstructions with resolution recovery corrections (RRC). The performance of the MC code was 3200 million photons/s. The required number of photons emitted per voxel to obtain a sufficiently low noise level in the simulated image was 200 for a 128 3 voxel matrix. With this number of emitted photons/voxel, the MC-based OSEM reconstruction with ten subsets was performed within 20 s/iteration. The images converged after around six iterations. Therefore, the reconstruction time was around 3 min. The activity recovery for the spheres in the Jaszczak phantom was

PEGylation, increasing specific activity and multiple dosing as strategies to improve the risk-benefit profile of targeted radionuclide therapy with 177Lu-DOTA-bombesin analogues

PubMed Central

2012-01-01

Background Radiolabelled bombesin (BN) conjugates are promising radiotracers for imaging and therapy of breast and prostate tumours, in which BN2/gastrin-releasing peptide receptors are overexpressed. We describe the influence of the specific activity of a 177Lu-DOTA-PEG5k-Lys-B analogue on its therapeutic efficacy and compare it with its non-PEGylated counterpart. Methods Derivatisation of a stabilised DOTA-BN(7–14)[Cha13,Nle14] analogue with a linear PEG molecule of 5 kDa (PEG5k) was performed by PEGylation of the ϵ-amino group of a β3hLys-βAla-βAla spacer between the BN sequence and the DOTA chelator. The non-PEGylated and the PEGylated analogues were radiolabelled with 177Lu. In vitro evaluation was performed in human prostate carcinoma PC-3 cells, and in vivo studies were carried out in nude mice bearing PC-3 tumour xenografts. Different specific activities of the PEGylated BN analogue and various dose regimens were evaluated concerning their therapeutic efficacy. Results The specificity and the binding affinity of the BN analogue for BN2/GRP receptors were only slightly reduced by PEGylation. In vitro binding kinetics of the PEGylated analogue was slower since steady-state condition was reached after 4 h. PEGylation improved the stability of BN conjugate in vitro in human plasma by a factor of 5.6. The non-PEGylated BN analogue showed favourable pharmacokinetics already, i.e. fast blood clearance and renal excretion, but PEGylation improved the in vivo behaviour further. One hour after injection, the tumour uptake of the PEG5k-BN derivative was higher compared with that of the non-PEGylated analogue (3.43 ± 0.63% vs. 1.88 ± 0.4% ID/g). Moreover, the increased tumour retention resulted in a twofold higher tumour accumulation at 24 h p.i., and increased tumour-to-non-target ratios (tumour-to-kidney, 0.6 vs. 0.4; tumour-to-liver, 8.8 vs. 5.9, 24 h p.i.). In the therapy study, both 177Lu-labelled BN analogues significantly inhibited tumour

Growth, spectroscopy and continuous-wave laser performance of Nd3+:LiLu0.65Y0.35F4 crystal

NASA Astrophysics Data System (ADS)

Demesh, M. P.; Kurilchik, S. V.; Gusakova, N. V.; Yasukevich, A. S.; Kisel, V. E.; Nizamutdinov, A. S.; Marisov, M. M.; Aglyamov, R. D.; Korableva, S. L.; Naumov, A. K.; Semashko, V. V.; Kuleshov, N. V.

2018-04-01

A mixed fluoride crystal of LiLu0.65Y0.35F4 doped with Nd3+ ions was grown by the Bridgman-Stockbarger method. Polarized absorption and luminescence spectra as well as luminescence lifetime were measured at room temperature. Emission probabilities, branching ratios and radiative lifetime were studied within the Judd-Ofelt theory and the emission cross section spectra were calculated. Efficient continuous wave laser operation was demonstrated with the crystal. A maximum output power of 7.7 W and slope efficiency of 60% were achieved at 1047 nm for the TEM00 mode.

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

NASA Astrophysics Data System (ADS)

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

2016-11-01

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

Spontaneous decays of magneto-elastic excitations in non-collinear antiferromagnet (Y,Lu)MnO3

PubMed Central

Oh, Joosung; Le, Manh Duc; Nahm, Ho-Hyun; Sim, Hasung; Jeong, Jaehong; Perring, T. G.; Woo, Hyungje; Nakajima, Kenji; Ohira-Kawamura, Seiko; Yamani, Zahra; Yoshida, Y.; Eisaki, H.; Cheong, S. -W.; Chernyshev, A. L.; Park, Je-Geun

2016-01-01

Magnons and phonons are fundamental quasiparticles in a solid and can be coupled together to form a hybrid quasi-particle. However, detailed experimental studies on the underlying Hamiltonian of this particle are rare for actual materials. Moreover, the anharmonicity of such magnetoelastic excitations remains largely unexplored, although it is essential for a proper understanding of their diverse thermodynamic behaviour and intrinsic zero-temperature decay. Here we show that in non-collinear antiferromagnets, a strong magnon–phonon coupling can significantly enhance the anharmonicity, resulting in the creation of magnetoelastic excitations and their spontaneous decay. By measuring the spin waves over the full Brillouin zone and carrying out anharmonic spin wave calculations using a Hamiltonian with an explicit magnon–phonon coupling, we have identified a hybrid magnetoelastic mode in (Y,Lu)MnO3 and quantified its decay rate and the exchange-striction coupling term required to produce it. PMID:27759004

The 176Lu-176Hf System as a Tool to Date Meteorites and Trace Early Silicate Differentiation - Requirements and Pitfalls

NASA Astrophysics Data System (ADS)

Bast, R.; Scherer, E. E.; Sprung, P.; Mezger, K.; Bischoff, A.

2016-12-01

The long-lived 176Lu-176Hf system is a potentially precise and robust chronometer, but when applied to meteorites, several "isochrons" exhibit excessive scatter and yield dates up to 300 Myr older than the Solar System [1-3]. Samples from different parent bodies produce similar patterns of scatter, whereas different pieces of the same meteorite yield contradictory results [e.g., 4-5]. These observations are difficult to explain by early Solar System irradiation [6-7] or diffusion [8-11] events. Instead, we infer that terrestrial contamination and weathering are more plausible disturbance mechanisms. Similar effects can, however, also be induced during sample handling [12-13]. Precise and accurate Lu-Hf chronology requires fresh, unaltered samples, and contamination must be removed without disturbing the target minerals. We have investigated various fractions of ALM-A, a trachyandesite from the Almahata Sitta meteorite fall. Impure mineral separates and bulk fractions contain terrestrial contamination as evidenced by excess 176Hf, whereas the purest, handpicked grains and selectively digested phosphate minerals yield a 13-point isochron with an age of 4569 ±24 Ma (MSWD = 1.3) using λ176Lu = 1.867 × 10-11 yr-1 [14-16]. The initial 176Hf/177Hf of 0.279796 ±0.000011 agrees well with other estimates of the initial 176Hf/177Hf of the Solar System [17-18] and supports the assumption of initial isotopic homogeneity among rocky planetary bodies with respect to Hf. [1] Blichert-Toft et al. (2002) EPSL 202, 167-181. [2] Bizzarro et al. (2003) Nature 421, 931-933. [3] Bizzarro et al. (2012) G³ 13, 10.1029/2011GC004003. [4] Bast et al. (under review) GCA. [5] Sanborn et al. (2015) GCA 171, 80-99. [6] Albarède et al. (2006) GCA 70, 1261-1270. [7] Thrane et al. (2010) Astrophys J 717, 861-867. [8] Debaille et al. (2011) LPI Contrib, 1639, 9066. [9] Debaille et al. (2013) Min Mag, 77, 957. [10] Debaille et al. (2014) Meteorit Planet Sci, 49, A5238. [11] Bloch et al. (2016

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.

Europium(III)-doped A2Hf2O7 (A = Y, Gd, Lu) nanoparticles: Influence of annealing temperature, europium(III) concentration and host cation on the luminescent properties

NASA Astrophysics Data System (ADS)

Papan, Jelena; Jovanović, Dragana J.; Vuković, Katarina; Smits, Krisjanis; Đorđević, Vesna; Dramićanin, Miroslav

2016-11-01

The detailed analyses of structure and luminescence of europium(III)-doped A2Hf2O7 (A = Y, Gd, Lu) nanoparticles is presented. Samples were prepared by time and cost effective combustion method that utilize polyethylene glycol both as a chelating agent and as a fuel, with different europium(III) concentrations (from 1 to 12 at.%), annealed at temperatures ranging from 800 to 1400 °C, and with alternating A3+ cation in the A2Hf2O7 host. Then, structural variations between materials were analysed by X-ray diffraction and structural refinement, while the changes in the luminescence were assessed from the Judd-Ofelt analyses of emission spectra. Nanoparticles prepared at the lowest temperature (800 °C) had the smallest particle size of ∼6 nm and showed the highest quantum efficiency when doped with 1 and 2 at.% of europium(III). Radiative transition rate and quantum efficiency of emission showed Lu2Hf2O7 > Gd2Hf2O7 > Y2Hf2O7 trend.

[Population density of Phlebotomus (Diptera; Psychodidae; Phlebotomine) species and their relationship with cutaneous leishmaniasis in Hocalli and Iurunçlu Villages (Adana)].

PubMed

Atakan, Ekrem; Akbaba, Muhsin; Sütoluk, Zeynel; Alptekın, Davut; Demırhındı, Hakan; Uludağ, Selen Kıs

2010-01-01

The aim of this study was the detection of cutaneous leishmaniasis (CL) cases at Turunçlu and Hocalli Villages, Adana, Turkey, where local cases had been observed in recent years, and to determine possible vectors and their seasonal density distribution. This was for the purpose of encouraging public awareness and thus leading to prevention. An initial questionnaire was responded by 567 people, with a male-to-female ratio of 45% to 55%. The physician in the research group examined the whole population of both villages for CL and then made monthly visits in order to detect new cases. Adhesive paper traps and CDC light traps were placed in houses and animal stables in order to collect sandflies, whose species were later determined in the laboratory. The CL prevalence was found to be 7.2%, with 30 old cases and 11 new cases. The number of cases in the Turunçlu Village was high with 17 men and 24 women affected. The case frequencies were not different between men and women (p > 0.05). The houses being whitewashed or kind of animal feeding were not found to affect the frequency of CL. In the two villages, 88 Phlebotomus were detected. P. papatasi and P. tobbi were of the genus Phlebotomus, while the genus Sergentomia was also observed. P.papatasi was most frequent in adhesive paper traps, while P.tobbi was frequent in light traps.

Synthesis and characterization of Na(Gd0.5Lu0.5)F4: Nd3+,a core-shell free multifunctional contrast agent.

PubMed

Mimun, L Christopher; Ajithkumar, G; Rightsell, Chris; Langloss, Brian W; Therien, Michael J; Sardar, Dhiraj K

2017-02-25

Compared to conventional core-shell structures, core-shell free nanoparticles with multiple functionalities offer several advantages such as minimal synthetic complexity and low production cost. In this paper, we present the synthesis and characterization of Nd 3+ doped Na(Gd 0.5 Lu 0.5 )F 4 as a core-shell free nanoparticle system with three functionalities. Nanocrystals with 20 nm diameter, high crystallinity and a narrow particle size distributions were synthesized by the solvothermal method and characterized by various analytical techniques to understand their phase and morphology. Fluorescence characteristics under near infrared (NIR) excitation at 808 nm as well as X-ray excitation were studied to explore their potential in NIR optical and X-ray imaging. At 1.0 mol% Nd concentration, we observed a quantum yield of 25% at 1064 nm emission with 13 W/cm 2 excitation power density which is sufficiently enough for imaging applications. Under 130 kVp (5 mA) power of X-ray excitation, Nd 3+ doped Na(Gd 0.5 Lu 0.5 )F 4 shows the characteristic emission bands of Gd 3+ and Nd 3+ with the strongest emission peak at 1064 nm due to Nd 3+ . Furthermore, magnetization measurements show that the nanocrystals are paramagnetic in nature with a calculated magnetic moment per particle of ~570 μB at 2T. These preliminary results support the suitability of the present nanophosphor as a multimodal contrast agent with three imaging features viz. optical, magnetic and X-ray.

Lu2O3-SiO2-ZrO2 Coatings for Environmental Barrier Application by Solution Precursor Plasma Spraying and Influence of Precursor Chemistry

NASA Astrophysics Data System (ADS)

Darthout, Émilien; Quet, Aurélie; Braidy, Nadi; Gitzhofer, François

2014-02-01

As environmental barrier coatings are subjected to thermal stress in gas turbine engines, the introduction of a secondary phase as zircon (ZrSiO4) is likely to increase the stress resistance of Lu2Si2O7 coatings generated by induction plasma spraying using liquid precursors. In a first step, precursor chemistry effect is investigated by the synthesis of ZrO2-SiO2 nanopowders by induction plasma nanopowder synthesis technique. Tetraethyl orthosilicate (TEOS) as silicon precursor and zirconium oxynitrate and zirconium ethoxide as zirconium precursors are mixed in ethanol and produce a mixture of tetragonal zirconia and amorphous silica nanoparticles. The use of zirconium ethoxide precursor results in zirconia particles with diameter below 50 nm because of exothermic thermal decomposition of the ethoxide and its high boiling point with respect to solvent, while larger particles are formed when zirconium oxynitrate is employed. The formation temperature of zircon from zirconia and silica oxides is found at 1425 °C. Second, coatings are synthesized in Lu2O3-ZrO2-SiO2 system. After heat treatment, the doping effect of lutetium on zirconia grains totally inhibits the zircon formation. Dense coatings are obtained with the use of zirconium ethoxide because denser particles with a homogeneous diameter distribution constitute the coating.

Probing the superconducting ground state of the rare-earth ternary boride superconductors R RuB2 (R = Lu,Y) using muon-spin rotation and relaxation

NASA Astrophysics Data System (ADS)

Barker, J. A. T.; Singh, R. P.; Hillier, A. D.; Paul, D. McK.

2018-03-01

The superconductivity in the rare-earth transition-metal ternary borides R RuB2 (where R =Lu and Y) has been investigated using muon-spin rotation and relaxation. Measurements made in zero field suggest that time-reversal symmetry is preserved upon entering the superconducting state in both materials; a small difference in depolarization is observed above and below the superconducting transition in both compounds, however, this has been attributed to quasistatic magnetic fluctuations. Transverse-field measurements of the flux-line lattice indicate that the superconductivity in both materials is fully gapped, with a conventional s -wave pairing symmetry and BCS-like magnitudes for the zero-temperature gap energies. The electronic properties of the charge carriers in the superconducting state have been calculated, with effective masses m*/me=9.8 ±0.1 and 15.0 ±0.1 in the Lu and Y compounds, respectively, with superconducting carrier densities ns=(2.73 ±0.04 ) ×1028m-3 and (2.17 ±0.02 ) ×1028m-3 . The materials have been classified according to the Uemura scheme for superconductivity, with values for Tc/TF of 1 /(414 ±6 ) and 1 /(304 ±3 ) , implying that the superconductivity may not be entirely conventional in nature.

On the timing of high-pressure metamorphism in Alpine Corsica: the first Lu-Hf garnet and lawsonite ages

NASA Astrophysics Data System (ADS)

Vitale Brovarone, A.; Herwartz, D.; Castelli, D.; Malavieille, J.

2012-04-01

Timing of HP metamorphism in Alpine Corsica is highly debated. Controversial biostratigraphic and radiometric constraints results in a poor understanding of the evolution of Alpine Corsica and its meaning in the Western Mediterranean dynamics. Age estimates provided by means of several techniques (e.g. Ar-Ar, Sa-Nd, U-Pb) vary form Late Cretaceous to Late Eocene. Some authors favor a Late Cretaceous peak metamorphism under HP conditions followed by Late Eocene and Early Oligocene blueschist and greenschist retrogression, respectively. Others favor a Late Eocene peak metamorphism and consider the older estimates as affected by analytical inaccuracy. In order to unravel this debate, we provide new Lu-Hf constraints on garnet and lawsonite from the lawsonite-eclogite and lawsonite-blueschist units of Alpine Corsica, which represent a part of the so-called Schistes Lustrés complex. The two investigated units are interpreted to represent remnants of the former Corsican ocean-continent transition zone [2]. As Lu concentrates in the cores of the selected minerals during the early stages of growth and blocking temperatures are high, this method provides robust insight on the timing of prograde/peak metamorphism [1]. Garnet and lawsonite separated form three lawsonite-eclogite samples yield systematic Late Eocene ages at ~ 34 Ma, while lawsonite from the lawsonite-blueschist unit yields a slightly older age at ~ 37 Ma. These data are in agreement with U-Pb data on zircon from the lawsonite-eclogite unit (~ 34 Ma) [3], but are in contrast with a recent U-Pb estimate on the Corsican continental margin unit metamorphosed under blueschist condition, yielding an age of ~ 55 Ma [4]. These discrepancies indicate a complex paleogeographic setting and a diachronous metamorphic evolution along the Corsican ocean-continent transition zone. The Late Eocene HP metamorphism in the Schistes Lustrés of Alpine Corsica also provides important constraints in the evolution of the Alps

Lu/Hf dating of garnet constrains timing of metamorphism and deformation, Prince Rupert Area, British Columbia

NASA Astrophysics Data System (ADS)

Wolf, D. E.; Andronicos, C. L.; Vervoort, J. D.; Mansfield, M.

2008-12-01

We present new Lu-Hf garnet ages that constrain the timing of deformation and metamorphism in the Western Metamorphic Belt (WMB), near Prince Rupert, British Columbia. We examined four samples of grt- bearing schist collected within the aureole to the Ecstall Pluton in the WMB. Garnets were separated from these rocks and dated using the Lu-Hf method at Washington State University. We determined geologically meaningful ages from three of these samples. The tectonic history of the Prince Rupert area is marked by phases of transpressive deformation, which included the development of crustal scale strike-slip shear zones and thrust slices with inverted metamorphic gradients. The Grenville Channel shear zone (GCSZ) is a crustal-scale sinistral-slip shear zone over 300 km long that strikes NW with a steep dip and shallow lineation. The GCSZ cuts through the WMB, a ductile fold and thrust belt composed of gneiss and schist with an inverted metamorphic sequence. Index minerals range from: chl and chd-grade units at the bottom of the sequence, str-bearing rocks in the middle, and ky-grt schist and local migmatites at the top of the thrust stack. The WMB was deformed and intruded by the Ecstall Pluton after the inverted metamorphic sequence had formed. The Ecstall is an epi-bearing hbl-qtz diorite emplaced between 91 and 93.5±1 Ma (Butler et al., 2001). Sample G-16A from Kumeleon Inlet (W of the Ecstall pluton) is a schist containing grt+biot+musc+qtz+epi+amph+sil, with small (<1 mm) euhedral grt. Kinematic indicators, including grt porphyroclasts, indicate left-lateral, top to the south, strike-slip shear. This sample yields a Lu-Hf age of 102±3.6 Ma (2σ, MSWD=1.5) based on seven grt and three whole-rock fractions, and a P-T estimate of 5.5±1 kbar and 590°±50° C from garnet-biotite thermobarometry. Sample 98-114A from Ridley Island (NW of Ecstall pluton) is a schist containing musc+biot+qtz+grt+ky+plag+chl+ill and with syn-tectonic euhedral garnet (1 cm). Grt

Caliciviruses in hospitalized children, São Luís, Maranhão, 1997-1999: detection of norovirus GII.12.

PubMed

Portal, Thayara Morais; Siqueira, Jones Anderson Monteiro; Costa, Larissa Cristina Prado das Neves; Lima, Ian Carlos Gomes de; Lucena, Maria Silvia Sousa de; Bandeira, Renato da Silva; Linhares, Alexandre da Costa; Luz, Claudia Regina Nunes Eloi da; Gabbay, Yvone Benchimol; Resque, Hugo Reis

2016-01-01

Gastroenteritis is one of the most common diseases during childhood, with norovirus (NoV) and sapovirus (SaV) being two of its main causes. This study reports for the first time the incidence of these viruses in hospitalized children with and without gastroenteritis in São Luís, Maranhão. A total of 136 fecal samples were tested by enzyme immunoassays (EIA) for the detection of NoV and by reverse transcription-polymerase chain reaction (RT-PCR) for detection of both NoV and SaV. Positive samples for both agents were subjected to sequencing. The overall frequency of NoV as detected by EIA and RT-PCR was 17.6% (24/136) and 32.6% (15/46), respectively in diarrheic patients and 10.0% (9/90) in non-diarrheic patients (p<0.01). Of the diarrheic patients, 17% had fever, vomiting and anorexia, and 13% developed fever, vomiting and abdominal pain. Of the 24 NoV-positive samples, 50% (12/24) were sequenced and classified as genotypes GII.3 (n=1), GII.4 (6), GII.5 (1), GII.7 (2), GII.12 (1) and GII.16 (1). SaV frequency was 9.8% (11/112), with 22.6% (7/31) in diarrheic patients and 4.9% (4/81) in nondiarrheic (p=0.04) ones. In diarrheic cases, 27.3% had fever, vomiting and anorexia, whereas 18.2% had fever, anorexia and abdominal pain. One SaV-positive sample was sequenced and classified as GII.1. These results show a high genetic diversity of NoV and higher prevalence of NoV compared to SaV. Our data highlight the importance of NoV and SaV as enteropathogens in São Luís, Maranhão. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.