Preparation & in vitro evaluation of 90Y-DOTA-rituximab

PubMed Central

Kameswaran, Mythili; Pandey, Usha; Dash, Ashutosh; Samuel, Grace; Venkatesh, Meera

2016-01-01

Background & objectives: Radioimmunotherapy is extensively being used for the treatment of non-Hodgkin's lymphoma (NHL). Use of rituximab, a chimeric anti-CD20 antibody directed against the CD20 antigen in combination with suitable beta emitters is expected to result in good treatment response by its cross-fire and bystander effects. The present work involves the conjugation of p-isothiocyanatobenzyl DOTA (p-SCN-Bn-DOTA) to rituximab, its radiolabelling with 90Y and in vitro and in vivo evaluation to determine its potential as a radioimmunotherapeutic agent. Methods: Rituximab was conjugated with p-SCN-Bn-DOTA at 1:1 antibody: DOTA molar ratio. The number of DOTA molecules linked to one molecule of rituximab was determined by radioassay and spectroscopic assay. Radiolabelling of rituximab with 90Y was carried out and its in vitro stability was evaluated. In vitro cell binding studies were carried out in Raji cells expressing CD20 antigen. Biodistribution studies were carried out in normal Swiss mice. Results: Using both radioassay and spectroscopic method, it was determined that about five molecules of DOTA were linked to rituximab. Radiolabelling of the rituximab conjugate with 90Y and subsequent purification on PD-10 column gave a product with radiochemical purity (RCP) > 98 per cent which was retained at > 90 per cent up to 72 h when stored at 37°C. In vitro cell binding experiments of 90Y-DOTA-rituximab with Raji cells exhibited specific binding of 20.7 ± 0.1 per cent with 90Y-DOTA-rituximab which reduced to 15.5 ± 0.2 per cent when incubated with cold rituximab. The equilibrium constant Kd for 90Y-DOTA-Rituximab was determined to be 3.38 nM. Radiolabelled antibody showed clearance via hepatobiliary and renal routes and activity in tibia was found to be quite low indicating in vivo stability of 90Y-DOTA-rituximab. Interpretation & conclusions: p-SCN-Bn-DOTA was conjugated with rituximab and radiolabelling with 90Y was carried out. In vitro studies carried

Performance of thin CaSO4:Dy pellets for calibration of a Sr90+Y90 source

NASA Astrophysics Data System (ADS)

Oliveira, M. L.; Caldas, L. V. E.

2007-09-01

Because of the radionuclide long half-life, Sr90+Y90, plane or concave sources, utilized in brachytherapy, have to be calibrated initially by the manufacturer and then routinely while they are utilized. Plane applicators can be calibrated against a conventional extrapolation chamber, but concave sources, because of their geometry, should be calibrated using relative dosimeters, as thermoluminescent (TL) materials. Thin CaSO4:Dy pellets are produced at IPEN specially for beta radiation detection. Previous works showed the feasibility of this material in the dosimetry of Sr90+Y90 sources in a wide range of absorbed dose in air. The aim of this work was to study the usefulness of these pellets for the calibration of a Sr90+Y90 concave applicator. To reach this objective, a special phantom was designed and manufactured in PTFE with semi spherical geometry. Because of the dependence of the TL response on the mass of the pellet, the response of each pellet was normalized by its mass in order to reduce the dispersion on TL response. Important characteristics of this material were obtained in reference of a standard Sr90+Y90 source, and the pellets were calibrated against a plane applicator; then they were utilized to calibrate the concave applicator.

Quantitative and Qualitative Assessment of Yttrium-90 PET/CT Imaging

PubMed Central

Büsing, Karen-Anett; Schönberg, Stefan O.; Bailey, Dale L.; Willowson, Kathy; Glatting, Gerhard

2014-01-01

Yttrium-90 is known to have a low positron emission decay of 32 ppm that may allow for personalized dosimetry of liver cancer therapy with 90Y labeled microspheres. The aim of this work was to image and quantify 90Y so that accurate predictions of the absorbed dose can be made. The measurements were performed within the QUEST study (University of Sydney, and Sirtex Medical, Australia). A NEMA IEC body phantom containing 6 fillable spheres (10–37 mm ∅) was used to measure the 90Y distribution with a Biograph mCT PET/CT (Siemens, Erlangen, Germany) with time-of-flight (TOF) acquisition. A sphere to background ratio of 8∶1, with a total 90Y activity of 3 GBq was used. Measurements were performed for one week (0, 3, 5 and 7 d). he acquisition protocol consisted of 30 min-2 bed positions and 120 min-single bed position. mages were reconstructed with 3D ordered subset expectation maximization (OSEM) and point spread function (PSF) for iteration numbers of 1–12 with 21 (TOF) and 24 (non-TOF) subsets and CT based attenuation and scatter correction. Convergence of algorithms and activity recovery was assessed based on regions-of-interest (ROI) analysis of the background (100 voxels), spheres (4 voxels) and the central low density insert (25 voxels). For the largest sphere, the recovery coefficient (RC) values for the 30 min –2-bed position, 30 min-single bed and 120 min-single bed were 1.12±0.20, 1.14±0.13, 0.97±0.07 respectively. For the smaller diameter spheres, the PSF algorithm with TOF and single bed acquisition provided a comparatively better activity recovery. Quantification of Y-90 using Biograph mCT PET/CT is possible with a reasonable accuracy, the limitations being the size of the lesion and the activity concentration present. At this stage, based on our study, it seems advantageous to use different protocols depending on the size of the lesion. PMID:25369020

One-neutron stripping processes to excited states of *90Y in the 89Y(6Li,5Li )*90Y reaction

NASA Astrophysics Data System (ADS)

Zhang, G. L.; Zhang, G. X.; Hu, S. P.; Yao, Y. J.; Xiang, J. B.; Zhang, H. Q.; Lubian, J.; Ferreira, J. L.; Paes, B.; Cardozo, E. N.; Sun, H. B.; Valiente-Dobón, J. J.; Testov, D.; Goasduff, A.; John, P. R.; Siciliano, M.; Galtarossa, F.; Francesco, R.; Mengoni, D.; Bazzacco, D.; Li, E. T.; Hao, X.; Qu, W. W.

2018-01-01

The measurement of one-neutron stripping cross sections for the 89Y(6Li,5Li )*90Y reaction at 22 MeV and 34 MeV is reported, using both in-beam and off-beam γ -ray spectroscopy methods. Characteristic γ lines of 90Y are clearly identified by both the γ -γ and proton-γ coincidence methods. The obtained cross section of one-neutron stripping at 34 MeV is found to be much smaller than that at 22 MeV. The one-neutron stripping cross sections measured for this system have the same order of magnitude as the one measured for the same reaction for the 6Li+96Zr system at energies around the Coulomb barrier. Parameter-free coupled reaction channel calculations agree quite well with the experimental data. Theoretical study of the effect of the one-neutron transfer on the elastic total fusion cross section is performed.

Assessment of acquisition protocols for routine imaging of Y-90 using PET/CT

PubMed Central

2013-01-01

Background Despite the early theoretical prediction of the 0+-0+ transition of 90Zr, 90Y-PET underwent only recently a growing interest for the development of imaging radioembolization of liver tumors. The aim of this work was to determine the minimum detectable activity (MDA) of 90Y by PET imaging and the impact of time-of-flight (TOF) reconstruction on detectability and quantitative accuracy according to the lesion size. Methods The study was conducted using a Siemens Biograph® mCT with a 22 cm large axial field of view. An IEC torso-shaped phantom containing five coplanar spheres was uniformly filled to achieve sphere-to-background ratios of 40:1. The phantom was imaged nine times in 14 days over 30 min. Sinograms were reconstructed with and without TOF information. A contrast-to-noise ratio (CNR) index was calculated using the Rose criterion, taking partial volume effects into account. The impact of reconstruction parameters on quantification accuracy, detectability, and spatial localization of the signal was investigated. Finally, six patients with hepatocellular carcinoma and four patients included in different 90Y-based radioimmunotherapy protocols were enrolled for the evaluation of the imaging parameters in a clinical situation. Results The highest CNR was achieved with one iteration for both TOF and non-TOF reconstructions. The MDA, however, was found to be lower with TOF than with non-TOF reconstruction. There was no gain by adding TOF information in terms of CNR for concentrations higher than 2 to 3 MBq mL−1, except for infra-centimetric lesions. Recovered activity was highly underestimated when a single iteration or non-TOF reconstruction was used (10% to 150% less depending on the lesion size). The MDA was estimated at 1 MBq mL−1 for a TOF reconstruction and infra-centimetric lesions. Images from patients treated with microspheres were clinically relevant, unlike those of patients who received systemic injections of 90Y. Conclusions Only

Radiation safety considerations with therapeutic 90Y Zevalin.

PubMed

Zhu, Xiaowei

2003-08-01

ABSTRACT Radioimmunotherapy with the 90Y-labeled Zevalin radioimmunoconjugate is a new and promising modality in cancer treatment that combines the targeting power of monoclonal antibodies with the cytotoxicity of localized radiation. 90Y is a pure beta emitter, with different physical characteristics than traditional therapeutic radionuclides such as 131I. It is important that radiation safety professionals understand the characteristics of this radionuclide so that effective radiation safety procedures can be implemented with the Zevalin regimen. Because 90Y is a pure beta emitter, the Zevalin regimen is routinely administered as an outpatient procedure and is administered by using plastic shielding. Once the radioimmunoconjugate has been administered, the risk of radiation exposure to healthcare workers and family members is minimal. The primary route of biologic elimination of 90Y Zevalin is through the urinary system, with approximately 7% of the total activity administered eliminated over the course of 1 wk. Standard universal precautions, which should already be in place in healthcare facilities, should be sufficient to prevent radiation exposure to personnel working with patients who have been treated with Zevalin. Written radiation safety instructions for patients are not required, but basic instructions to the patient and his or her family may help further minimize the risk of radiation exposure and help alleviate patient and family concerns.

Radioembolization with 90Y glass microspheres for hepatocellular carcinoma: significance of pretreatment 11C-acetate and 18F-FDG PET/CT and posttreatment 90Y PET/CT in individualized dose prescription.

PubMed

Ho, Chi Lai; Chen, Sirong; Cheung, Shing Kee; Leung, Yim Lung; Cheng, Kam Chau; Wong, Ka Nin; Wong, Yuet Hung; Leung, Thomas Wai Tong

2018-06-11

The aim of this study was to establish an algorithm for the prescription of 90 Y glass microsphere radioembolization ( 90 Y-GMRE) of HCC in individual patients based on the relationship between tumour dose (TD) and response validated by 90 Y PET/CT dosimetry and dual-tracer PET/CT metabolic parameters. The study group comprised 62 HCC patients prospectively recruited for 90 Y-GMRE who underwent pretreatment dual-tracer ( 11 C-acetate and 18 F-FDG) PET/CT as surrogate markers of HCC cellular differentiation. Pretreatment tumour-to-nontumour ratio on 99m Tc-MAA SPECT/CT (T/NT MAA ) was correlated with posttreatment 90 Y PET/CT T/NT 90Y after quantification validation. The TD-response relationship for HCC of different tracer groups was assessed on follow-up PET/CT 2 months after treatment. 90 Y PET/CT was accurate in the measurement of recovery of injected 90 Y activity (81.9-99.9%, median 94.8%). Pretreatment SPECT/CT T/NT MAA was strongly correlated with posttreatment 90 Y PET/CT T/NT 90Y (5.6 ± 3.2 versus 5.9 ± 3.5, T/NT 90Y 1.01 × T/NT MAA  + 0.161, r = 0.918, P < 0.05). The response rates were 72.4% (21/29), 70.6% (12/17) and 25% (4/16) for well, moderately and poorly differentiated HCC, respectively. The cut-off TD for a good response was significantly different between poorly differentiated and well/moderately differentiated HCC (262 Gy versus 152/174 Gy) with 89.2% sensitivity and 88% specificity. At a limiting tolerated liver dose of 70 Gy, the T/NT MAA thresholds for predicting a good response in poorly differentiated and well/moderately differentiated HCC were 3.5 and 2.0/2.3. Disregarding HCC cellular differentiation, the cut-off TD became 170 Gy, with lower sensitivity (70.3%) and specificity (76%). 90 Y PET/CT can provide accurate dosimetry for 90 Y-GMRE. Pretreatment T/NT MAA predicts posttreatment T/NT 90Y . The TD thresholds for a good response are tracer-dependent, with a strong correlation between HCC radiosensitivity

Y-90 SPECT ML image reconstruction with a new model for tissue-dependent bremsstrahlung production using CT information: a proof-of-concept study

NASA Astrophysics Data System (ADS)

Lim, Hongki; Fessler, Jeffrey A.; Wilderman, Scott J.; Brooks, Allen F.; Dewaraja, Yuni K.

2018-06-01

While the yield of positrons used in Y-90 PET is independent of tissue media, Y-90 SPECT imaging is complicated by the tissue dependence of bremsstrahlung photon generation. The probability of bremsstrahlung production is proportional to the square of the atomic number of the medium. Hence, the same amount of activity in different tissue regions of the body will produce different numbers of bremsstrahlung photons. Existing reconstruction methods disregard this tissue-dependency, potentially impacting both qualitative and quantitative imaging of heterogeneous regions of the body such as bone with marrow cavities. In this proof-of-concept study, we propose a new maximum-likelihood method that incorporates bremsstrahlung generation probabilities into the system matrix, enabling images of the desired Y-90 distribution to be reconstructed instead of the ‘bremsstrahlung distribution’ that is obtained with existing methods. The tissue-dependent probabilities are generated by Monte Carlo simulation while bone volume fractions for each SPECT voxel are obtained from co-registered CT. First, we demonstrate the tissue dependency in a SPECT/CT imaging experiment with Y-90 in bone equivalent solution and water. Visually, the proposed reconstruction approach better matched the true image and the Y-90 PET image than the standard bremsstrahlung reconstruction approach. An XCAT phantom simulation including bone and marrow regions also demonstrated better agreement with the true image using the proposed reconstruction method. Quantitatively, compared with the standard reconstruction, the new method improved estimation of the liquid bone:water activity concentration ratio by 40% in the SPECT measurement and the cortical bone:marrow activity concentration ratio by 58% in the XCAT simulation.

{sup 90}Y -PET imaging: Exploring limitations and accuracy under conditions of low counts and high random fraction

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

Carlier, Thomas, E-mail: thomas.carlier@chu-nantes.fr; Willowson, Kathy P.; Fourkal, Eugene

Purpose: {sup 90}Y -positron emission tomography (PET) imaging is becoming a recognized modality for postinfusion quantitative assessment following radioembolization therapy. However, the extremely low counts and high random fraction associated with {sup 90}Y -PET may significantly impair both qualitative and quantitative results. The aim of this work was to study image quality and noise level in relation to the quantification and bias performance of two types of Siemens PET scanners when imaging {sup 90}Y and to compare experimental results with clinical data from two types of commercially available {sup 90}Y microspheres. Methods: Data were acquired on both Siemens Biograph TruePointmore » [non-time-of-flight (TOF)] and Biograph microcomputed tomography (mCT) (TOF) PET/CT scanners. The study was conducted in three phases. The first aimed to assess quantification and bias for different reconstruction methods according to random fraction and number of true counts in the scan. The NEMA 1994 PET phantom was filled with water with one cylindrical insert left empty (air) and the other filled with a solution of {sup 90}Y . The phantom was scanned for 60 min in the PET/CT scanner every one or two days. The second phase used the NEMA 2001 PET phantom to derive noise and image quality metrics. The spheres and the background were filled with a {sup 90}Y solution in an 8:1 contrast ratio and four 30 min acquisitions were performed over a one week period. Finally, 32 patient data (8 treated with Therasphere{sup ®} and 24 with SIR-Spheres{sup ®}) were retrospectively reconstructed and activity in the whole field of view and the liver was compared to theoretical injected activity. Results: The contribution of both bremsstrahlung and LSO trues was found to be negligible, allowing data to be decay corrected to obtain correct quantification. In general, the recovered activity for all reconstruction methods was stable over the range studied, with a small bias appearing at

Pyclen Tri-n-butylphosphonate Ester as Potential Chelator for Targeted Radiotherapy: From Yttrium(III) Complexation to (90)Y Radiolabeling.

PubMed

Le Fur, Mariane; Beyler, Maryline; Lepareur, Nicolas; Fougère, Olivier; Platas-Iglesias, Carlos; Rousseaux, Olivier; Tripier, Raphaël

2016-08-15

The Y(3+) complex of PCTMB, the tri-n-butyl phosphonate ester of pyclen (3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene), was synthesized as well as its Ho(3+) and Lu(3+) analogues. X-ray diffraction analyses revealed isomorphous dimeric M2(PCTMB)2·9H2O (M = Y, Ho, Lu) structures that crystallize in the centrosymmetric P1̅ triclinic space group. (1)H NMR and UV studies in aqueous solutions indicated that Y(3+) complexation is fast, being quantitative in 167 min at pH 3.8 and in 13 min at pH 5.5 (25 °C, acetate buffer, I = 0.150 M, [Y(3+)] = [PCTMB] = 0.2 mM). (1)H NMR DOSY and photon correlation spectroscopy experiments evidenced the formation of aggregates in chloroform with a bimodal distribution that changes slightly with concentration (11-24 and 240-258 nm). The behavior of the acid-assisted dissociation of the complex of Y(3+) with PCTMB was studied under pseudo-first-order conditions, and the half-life of the [Y(PCTMB)] complex in 0.5 M HCl at 25 °C was found to be 37 min, a value that decreases to 2.6 min in 5 M HCl. The Y(3+) complex of PCTMB is thermodynamically very stable, with a stability constant of log KY-PCTMB = 19.49 and pY = 16.7 measured by potentiometry. (90)Y complexation studies revealed fast radiolabeling kinetics; optimal radiolabeling conditions were obtained for (90)Y in acetate medium, PCTMB at 10(-4) to 10(-2) M in acetate buffer pH = 4.75, 15 min at 45-60 °C. In vitro stability studies in human serum showed that [(90)Y(PCTMB)] is quite stable, with about 90% of the activity still in the form of the radiotracer at 24 h and 80% from 48 h to 72 h. A comparison with other ligands such as PCTA, DOTA, and DTPA already used for in vivo application shows that [(90)Y(PCTMB)] is an interesting lipophilic and neutral analogue of these reference chelates for therapeutic applications in aqueous and nonaqueous media.

Monte Carlo simulation of PET and SPECT imaging of {sup 90}Y

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

Takahashi, Akihiko, E-mail: takahsr@hs.med.kyushu-u.ac.jp; Sasaki, Masayuki; Himuro, Kazuhiko

2015-04-15

Purpose: Yittrium-90 ({sup 90}Y) is traditionally thought of as a pure beta emitter, and is used in targeted radionuclide therapy, with imaging performed using bremsstrahlung single-photon emission computed tomography (SPECT). However, because {sup 90}Y also emits positrons through internal pair production with a very small branching ratio, positron emission tomography (PET) imaging is also available. Because of the insufficient image quality of {sup 90}Y bremsstrahlung SPECT, PET imaging has been suggested as an alternative. In this paper, the authors present the Monte Carlo-based simulation–reconstruction framework for {sup 90}Y to comprehensively analyze the PET and SPECT imaging techniques and to quantitativelymore » consider the disadvantages associated with them. Methods: Our PET and SPECT simulation modules were developed using Monte Carlo simulation of Electrons and Photons (MCEP), developed by Dr. S. Uehara. PET code (MCEP-PET) generates a sinogram, and reconstructs the tomography image using a time-of-flight ordered subset expectation maximization (TOF-OSEM) algorithm with attenuation compensation. To evaluate MCEP-PET, simulated results of {sup 18}F PET imaging were compared with the experimental results. The results confirmed that MCEP-PET can simulate the experimental results very well. The SPECT code (MCEP-SPECT) models the collimator and NaI detector system, and generates the projection images and projection data. To save the computational time, the authors adopt the prerecorded {sup 90}Y bremsstrahlung photon data calculated by MCEP. The projection data are also reconstructed using the OSEM algorithm. The authors simulated PET and SPECT images of a water phantom containing six hot spheres filled with different concentrations of {sup 90}Y without background activity. The amount of activity was 163 MBq, with an acquisition time of 40 min. Results: The simulated {sup 90}Y-PET image accurately simulated the experimental results. PET image is

Method of separation of yttrium-90 from strontium-90

DOEpatents

Bray, Lane A.; Wester, Dennis W.

1996-01-01

A method for purifying Y-90 from a Sr-90/Y-90 "cow" wherein raw Sr-90/Y-90 source containing impurities is obtained from nuclear material reprocessing. Raw Sr-90/Y-90 source is purified to a fresh Sr-90/Y-90 source "cow" by removing impurities by addition of sodium hydroxide and by removing Cs-137 by further addition of sodium carbonate. The "cow" is set aside to allow ingrowth. An HDEHP organic extractant is obtained from a commercial supplier and further purified by saturation with Cu(II), precipitation with acetone, and washing with nitric acid. The "cow" is then dissolved in nitric acid and the purified HDEHP is washed with nitric acid and scrubbed with either nitric or hydrochloric acid. The dissolved "cow" and scrubbed HDEHP are combined in an organic extraction, separating Y-90 from Sr-90, resulting in a Sr-90/Y-90 concentration ratio of not more than 10(E-7), and a metal impurity concentration of not more than 10 ppm per curie of Y-90. The separated Y-90 may then be prepared for delivery.

Personnel dose reduction in 90Y microspheres liver-directed radioembolization: from interventional radiology suite to patient ward

PubMed Central

Wong, K K; Tso, W K; Lee, Victor; Luk, M Y; Tong, C C; Chu, Ferdinand

2017-01-01

Objective: To describe a method to reduce the external radiation exposure emitted from the patient after liver-directed radioembolization using 90Y glass microspheres, to quantitatively estimate the occupational dose of medical personnel providing patient care to the patient radioembolized with the use of the method and to discuss radiation exposure to patients who are adjacent if the patient radioembolized needs hospitalization. Methods: A lead-lined blanket of lead equivalence of 0.5 mm was used to cover the patient abdomen immediately after the 90Y radioembolization procedure, in order to reduce the radiation emitted from the patient. The interventional radiologist used a rod-type puncture site compressor for haemostasis to avoid direct contact with possible residual radioactivity at the puncture site. Dose rates were measured at the interventional radiologist chest and hand positions during puncture site pressing for haemostasis with and without the use of the blanket. The measurement results were applied to estimate the occupational dose of colleagues performing patient care to the patient radioembolized. The exposure to patients adjacent in the ward was estimated if the patient radioembolized was hospitalized. Results: The radiation exposures measured at the radiologist chest and hand positions have been significantly reduced with the lead-lined blanket in place. The radiologist, performing puncture site pressing at the end of radioembolization procedure, would receive an average hand dose of 1.95 μSv and body dose under his own lead apron of 0.30 μSv for an average 90Y microsphere radioactivity of 2.54 GBq. Other medical personnel, nurses and porters, would receive occupational doses corresponding to an hour of background radiation. If the patient radioembolized using 90Y needs hospitalization in a common ward, using the lead-lined blanket to cover the abdomen of the patient and keeping a distance of 2 m from the patient who is adjacent would

Radiation protection in radionuclide therapies with (90)Y-conjugates: risks and safety.

PubMed

Cremonesi, Marta; Ferrari, Mahila; Paganelli, Giovanni; Rossi, Annalisa; Chinol, Marco; Bartolomei, Mirco; Prisco, Gennaro; Tosi, Giampiero

2006-11-01

The widespread interest in (90)Y internal radionuclide treatments has drawn attention to the issue of radiation protection for staff. Our aim in this study was to identify personnel at risk and to validate the protection devices used. (90)Y-MoAb (Zevalin, 15 cases, 1.1 GBq/patient) and (90)Y-peptide ((90)Y-DOTATOC) systemic (i.v., 50 cases, 3.0 GBq/patient) and locoregional (l.r., 50 cases, 0.4 GBq/patient) treatments were considered. Radiolabelling was carried out in a dedicated hot cell. Tele-tongs, shielded (PMMA: polymethylmethacrylate) syringes/vials and an automatic dose fractionating system were used. Operators wore anti-X-ray and anti-contamination gloves, with TLD dosimeters placed over the fingertips. For i.v. administration, activity was administered by a dedicated system; for l.r. administration, during activity infusion in the brain cavity, tongs were used and TLDs were placed over the fingertips. The air kerma-rate was measured around the patients. The use of devices provided a 75% dose reduction, with mean fingertip doses of 2.9 mGy (i.v. MoAbs), 0.6 mGy (i.v. peptides)/radiolabelling procedure and 0.5 mGy/l.r. administration. The mean effective dose to personnel was 5 microSv/patient. The air kerma-rate around the patients administered i.v. (90)Y-peptides were 3.5 (1 h) and 1.0 (48 h) microGy/h at 1 m. Patient hospitalisation of 6 h (l.r.)/48 h (i.v.) guaranteed that the recommended limits of 3 mSv/year to family members and 0.3 mSv/year to the general population (Council Directive 97/43/Euratom) were respected. When specific procedures are adopted, a substantial improvement in (90)Y manipulation is attainable, reducing doses and increasing safety. For the widespread clinical use of (90)Y-conjugates, a completely automatic labelling procedure is desirable.

Method of separation of yttrium-90 from strontium-90

DOEpatents

Bray, L.A.; Wester, D.W.

1996-04-30

A method is described for purifying Y-90 from a Sr-90/Y-90 ``cow`` wherein raw Sr-90/Y-90 source containing impurities is obtained from nuclear material reprocessing. Raw Sr-90/Y-90 source is purified to a fresh Sr-90/Y-90 source ``cow`` by removing impurities by addition of sodium hydroxide and by removing Cs-137 by further addition of sodium carbonate. The ``cow`` is set aside to allow ingrowth. An HDEHP organic extractant is obtained from a commercial supplier and further purified by saturation with Cu(II), precipitation with acetone, and washing with nitric acid. The ``cow`` is then dissolved in nitric acid and the purified HDEHP is washed with nitric acid and scrubbed with either nitric or hydrochloric acid. The dissolved ``cow`` and scrubbed HDEHP are combined in an organic extraction, separating Y-90 from Sr-90, resulting in a Sr-90/Y-90 concentration ratio of not more than 10(E-7), and a metal impurity concentration of not more than 10 ppm per curie of Y-90. The separated Y-90 may then be prepared for delivery. 1 fig.

Y-90-DOTA-hLL2: An Agent for Radioimmunotherapy of Non-Hodgkin's Lymphoma

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

Griffiths, Gary L.; Govindan, Serengulam V.; Sharkey, Robert M.

2003-01-01

The goal of this work was to determine an optimal radioimmunotherapy agent for non-Hodgkin's lymphoma. We established the stability profile of yttrium-90-labeled humanized LL2 (hLL2) monoclonal antibody prepared with different chelating agents, and from these data estimated the improvement using the most stable yttrium-90 chelate-hLL2 complex. Methods: The complementary-determining region- (cdr)-grafted (humanized) anti-CD22 mAb, hLL2 (epratuzumab), was conjugated to derivatives of DTPA and 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA). The conjugates were labeled with Y-90 and tested against a 10,000-fold molar excess of free DTPA and against human serum. The conjugates were also labeled with Y-88 and compared for biodistribution in normal andmore » lymphoma xenograft-bearing athymic mice. In vivo data were analyzed for uptake of yttrium in bone and washed bone when either the DOTA or the Mx-DTPA chelates were used, and dosimetry calculations were made for each. Results: Y-90-DOTA -mAb were stable to either DTPA or serum challenge. DTPA complexes of hLL2 lost 3-4% of Y-90 (days 1-4) and 10-15% thereafter. In vivo, stability differences showed lower Y-90 uptake in bone using DOTA. Absorbed doses per 37 MBq (1 mCi) Y-90-mAb were 3555 and 5405 cGy for bone, and 2664 and 4524 cGy for washed-bone for 90Y-DOTA-hLL2 and 90Y-MxDTPA-hLL2, respectively, amounting to 52% and 69.8% increases in absorbed radiation doses for bone and washed-bone when switching from a DOTA to a Mx-DTPA chelate. Conclusion: Y-90-hLL2 prepared with the DOTA chelate represents a preferred agent for RAIT of non-Hodgkin's lymphoma, with an in vivo model demonstrating a large reduction in bone-deposited yttrium, as compared to yttrium-90-hLL2 agents prepared with open-chain DTPA-type chelating agents. Dosimetry suggests that this will result in a substantial toxicological advantage for a DOTA-based hLL2 conjugate.« less

Detection of bremsstrahlung radiation of 90Sr-90Y for emergency lung counting.

PubMed

Ho, A; Hakmana Witharana, S S; Jonkmans, G; Li, L; Surette, R A; Dubeau, J; Dai, X

2012-09-01

This study explores the possibility of developing a field-deployable (90)Sr detector for rapid lung counting in emergency situations. The detection of beta-emitters (90)Sr and its daughter (90)Y inside the human lung via bremsstrahlung radiation was performed using a 3″ × 3″ NaI(Tl) crystal detector and a polyethylene-encapsulated source to emulate human lung tissue. The simulation results show that this method is a viable technique for detecting (90)Sr with a minimum detectable activity (MDA) of 1.07 × 10(4) Bq, using a realistic dual-shielded detector system in a 0.25-µGy h(-1) background field for a 100-s scan. The MDA is sufficiently sensitive to meet the requirement for emergency lung counting of Type S (90)Sr intake. The experimental data were verified using Monte Carlo calculations, including an estimate for internal bremsstrahlung, and an optimisation of the detector geometry was performed. Optimisations in background reduction techniques and in the electronic acquisition systems are suggested.

Quantitative surface topography determination by Nomarski reflection microscopy. 2: Microscope modification, calibration, and planar sample experiments

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

Hartman, J.S.; Gordon, R.L.; Lessor, D.L.

1980-09-01

The application of reflective Nomarski differential interference contrast microscopy for the determination of quantitative sample topography data is presented. The discussion includes a review of key theoretical results presented previously plus the experimental implementation of the concepts using a commercial Momarski microscope. The experimental work included the modification and characterization of a commercial microscope to allow its use for obtaining quantitative sample topography data. System usage for the measurement of slopes on flat planar samples is also discussed. The discussion has been designed to provide the theoretical basis, a physical insight, and a cookbook procedure for implementation to allow thesemore » results to be of value to both those interested in the microscope theory and its practical usage in the metallography laboratory.« less

Monte Carlo simulation of depth-dose distributions in TLD-100 under 90Sr-90Y irradiation.

PubMed

Rodríguez-Villafuerte, M; Gamboa-deBuen, I; Brandan, M E

1997-04-01

In this work the depth-dose distribution in TLD-100 dosimeters under beta irradiation from a 90Sr-90Y source was investigated using the Monte Carlo method. Comparisons between the simulated data and experimental results showed that the depth-dose distribution is strongly affected by the different components of both the source and dosimeter holders due to the large number of electron scattering events.

Characterizing hydrophobicity of amino acid side chains in a protein environment via measuring contact angle of a water nanodroplet on planar peptide network

PubMed Central

Zhu, Chongqin; Gao, Yurui; Li, Hui; Meng, Sheng; Li, Lei; Francisco, Joseph S.; Zeng, Xiao Cheng

2016-01-01

Hydrophobicity of macroscopic planar surface is conventionally characterized by the contact angle of water droplets. However, this engineering measurement cannot be directly extended to surfaces of proteins, due to the nanometer scale of amino acids and inherent nonplanar structures. To measure the hydrophobicity of side chains of proteins quantitatively, numerous parameters were developed to characterize behavior of hydrophobic solvation. However, consistency among these parameters is not always apparent. Herein, we demonstrate an alternative way of characterizing hydrophobicity of amino acid side chains in a protein environment by constructing a monolayer of amino acids (i.e., artificial planar peptide network) according to the primary and the β-sheet secondary structures of protein so that the conventional engineering measurement of the contact angle of a water droplet can be brought to bear. Using molecular dynamics simulations, contact angles θ of a water nanodroplet on the planar peptide network, together with excess chemical potentials of purely repulsive methane-sized Weeks−Chandler−Andersen solute, are computed. All of the 20 types of amino acids and the corresponding planar peptide networks are studied. Expectedly, all of the planar peptide networks with nonpolar amino acids are hydrophobic due to θ > 90°, whereas all of the planar peptide networks of the polar and charged amino acids are hydrophilic due to θ < 90°. Planar peptide networks of the charged amino acids exhibit complete-wetting behavior due to θ = 0°. This computational approach for characterization of hydrophobicity can be extended to artificial planar networks of other soft matter. PMID:27803319

Characterizing hydrophobicity of amino acid side chains in a protein environment via measuring contact angle of a water nanodroplet on planar peptide network.

PubMed

Zhu, Chongqin; Gao, Yurui; Li, Hui; Meng, Sheng; Li, Lei; Francisco, Joseph S; Zeng, Xiao Cheng

2016-11-15

Hydrophobicity of macroscopic planar surface is conventionally characterized by the contact angle of water droplets. However, this engineering measurement cannot be directly extended to surfaces of proteins, due to the nanometer scale of amino acids and inherent nonplanar structures. To measure the hydrophobicity of side chains of proteins quantitatively, numerous parameters were developed to characterize behavior of hydrophobic solvation. However, consistency among these parameters is not always apparent. Herein, we demonstrate an alternative way of characterizing hydrophobicity of amino acid side chains in a protein environment by constructing a monolayer of amino acids (i.e., artificial planar peptide network) according to the primary and the β-sheet secondary structures of protein so that the conventional engineering measurement of the contact angle of a water droplet can be brought to bear. Using molecular dynamics simulations, contact angles θ of a water nanodroplet on the planar peptide network, together with excess chemical potentials of purely repulsive methane-sized Weeks-Chandler-Andersen solute, are computed. All of the 20 types of amino acids and the corresponding planar peptide networks are studied. Expectedly, all of the planar peptide networks with nonpolar amino acids are hydrophobic due to θ [Formula: see text] 90°, whereas all of the planar peptide networks of the polar and charged amino acids are hydrophilic due to θ [Formula: see text] 90°. Planar peptide networks of the charged amino acids exhibit complete-wetting behavior due to θ [Formula: see text] 0°. This computational approach for characterization of hydrophobicity can be extended to artificial planar networks of other soft matter.

Therapeutic equivalence in survival for hepatic arterial chemoembolization and 90Yttrium microspheres (Y90) treatments in unresectable hepatocellular carcinoma: a 2 cohort study

PubMed Central

Carr, Brian I.; Kondragunta, Venkateswarlu; Buch, Shama C.; Branch, Robert A.

2009-01-01

BACKGROUND Intra-hepatic arterial 90Yttrium (Y90) microspheres (Theraspheres) have been proposed as a less toxic, invasive therapeutic option to trans-hepatic arterial chemoembolization (TACE) for surgically unresectable hepatocellular carcinoma (HCC). TACE has been shown to prolong survival. However, long term survival remains uncertain. METHODS A 2 cohort experience of the treatment of advanced, unresectable and biopsy-proven HCC in North American patients is presented. 691 patients received repetitive cisplatin-based chemoembolization and a following 99 patient cohort with similar treatment criteria, received a planned single dose of Y90. Over this time period, an additional 142 patients were followed without treatment (total: 932 patients). RESULTS Overall survival was slightly better in the Y90 group compared to TACE, median of 11.5 vs. 8.5 months. However, selection criteria indicated a small but significant bias towards milder disease in the Y90 group. Using stratification in a 3 tier model, with cases dichotomized by bilirubin of less than 1.5 mg/dL, patients without PVT or with low alpha-fetoprotein plasma levels of less than 25 units/dL, analysis of survival in clinical subgroups showed that the 2 treatments resulted in similar survival. Similarly, patients with PVT or a high alpha-fetoprotein also had similar survival in the 2 treatment groups. CONCLUSION Given the present evidence of therapeutic equivalence in survival, Y90 and TACE seem to be equivalent regional therapies for patients with unresectable, non-metastatic HCC. PMID:20066715

A comparative evaluation of the chelators H4octapa and CHX-A″-DTPA with the therapeutic radiometal (90)Y.

PubMed

Price, Eric W; Edwards, Kimberly J; Carnazza, Kathryn E; Carlin, Sean D; Zeglis, Brian M; Adam, Michael J; Orvig, Chris; Lewis, Jason S

2016-09-01

To compare the radiolabeling performance, stability, and practical efficacy of the chelators CHX-A″-DTPA and H4octapa with the therapeutic radiometal (90)Y. The bifunctional chelators p-SCN-Bn-H4octapa and p-SCN-Bn-CHX-A″-DTPA were conjugated to the HER2-targeting antibody trastuzumab. The resulting immunoconjugates were radiolabeled with (90)Y to compare radiolabeling efficiency, in vitro and in vivo stability, and in vivo performance in a murine model of ovarian cancer. High radiochemical yields (>95%) were obtained with (90)Y-CHX-A″-DTPA-trastuzumab and (90)Y-octapa-trastuzumab after 15min at room temperature. Both (90)Y-CHX-A″-DTPA-trastuzumab and (90)Y-octapa-trastuzumab exhibited excellent in vitro and in vivo stability. Furthermore, the radioimmunoconjugates displayed high tumoral uptake values (42.3±4.0%ID/g for (90)Y-CHX-A″-DTPA-trastuzumab and 30.1±7.4%ID/g for (90)Y-octapa-trastuzumab at 72h post-injection) in mice bearing HER2-expressing SKOV3 ovarian cancer xenografts. Finally, (90)Y radioimmunotherapy studies performed in tumor-bearing mice demonstrated that (90)Y-CHX-A″-DTPA-trastuzumab and (90)Y-octapa-trastuzumab are equally effective therapeutic agents, as treatment with both radioimmunoconjugates yielded substantially decreased tumor growth compared to controls. Ultimately, this work demonstrates that the acyclic chelators CHX-A″-DTPA and H4octapa have comparable radiolabeling, stability, and in vivo performance, making them both suitable choices for applications requiring (90)Y. Copyright © 2016 Elsevier Inc. All rights reserved.

Yttrium-90 (Y-90) Resin Microsphere Therapy for Patients with Unresectable Hepatocellular Carcinoma: a Single-Center Experience.

PubMed

İnce, Semra; Karaman, Bülent; Alagoz, Engin; Karadurmuş, Nuri; Şan, Hüseyin; Erçin, Cemal Nuri; Arslan, Nuri

2017-09-01

Selective intraarterial radionuclide therapy (SIRT) with yttrium-90 (Y-90) resin microspheres presently has successful results in primary or metastatic inoperable liver tumors. This procedure, which is also known as radioembolisation, delivers high doses of radiation selectively to hepatic tumors while minimum healthy liver exposure. The aim of this study was to present our clinical experience of radiomicrosphere therapy for the treatment of patients with unresectable hepatocellular carcinoma (HCC). We performed 40 Y-90 microsphere therapies in 28 patients (5 females, 23 males; mean age ± SD 48 ± 8) with HCC during the period from April 2008 through December 2016. Pretreatment Tc-99m microaggregated albumin (MAA) scintigraphy was performed to all patients in order to detect eligibility for SIRT. All patients had pre- and post-biochemical tests (hemogram and serologic tests) and imaging methods (CT or MRI or PET/CT) at regular intervals to detect any possible complication and determine response rates. The mean shunting to the lungs on MAA scan was 6.5% and the mean ± SD administered dose of Y-90 was 1.55 ± 0.32 GBq in all patients. The estimated doses to the target tumors, normal liver parenchyma and lungs were 105.7 ± 55.3, 25.5 ± 8.2 and 5.8 ± 1.7 Gy, respectively. No significant complication was observed during or early after (first week) the treatment procedure and it was well tolerated by all the patients. Only one patient developed a treatment-related gastroduodenal ulcer 3 weeks after the treatment. In control imaging tests (MRI or FDG PET/CT) performed 2.5 months after the treatment, we observed complete response in 2 (7%) patients, partial response in 10 (36%) patients, stable disease in 5 (18%) patients and progressive disease in 11 (39%) patients. According to our clinical experience, we can conclude that Y-90 microsphere therapy is a safe and effective treatment option for the patients with unresectable HCC without any serious

Little effect of HSP90 inhibition on the quantitative wing traits variation in Drosophila melanogaster.

PubMed

Takahashi, Kazuo H

2017-02-01

Drosophila wings have been a model system to study the effect of HSP90 on quantitative trait variation. The effect of HSP90 inhibition on environmental buffering of wing morphology varies among studies while the genetic buffering effect of it was examined in only one study and was not detected. Variable results so far might show that the genetic background influences the environmental and genetic buffering effect of HSP90. In the previous studies, the number of the genetic backgrounds used is limited. To examine the effect of HSP90 inhibition with a larger number of genetic backgrounds than the previous studies, 20 wild-type strains of Drosophila melanogaster were used in this study. Here I investigated the effect of HSP90 inhibition on the environmental buffering of wing shape and size by assessing within-individual and among-individual variations, and as a result, I found little or very weak effects on environmental and genetic buffering. The current results suggest that the role of HSP90 as a global regulator of environmental and genetic buffering is limited at least in quantitative traits.

Spectral behavior of integrated optics asymmetric y-junction used for optimizing a planar optics telescope beam combiner

NASA Astrophysics Data System (ADS)

Schanen-Duport, Isabelle; Persegol, Dominique; Collomb, Virginie; Minier, Vincent; Haguenauer, Pierre

2017-11-01

Astronomical aperture synthesis requires to combine beams coming from telescopes, with constraints on mechanical and thermal stability, accuracy on the measurement of the interferences visibility. One adapted way for solving the problem is integrated planar optics. A first two telescope beam combiner made by ion exchange technique on glass substrate and build with symmetric Y-junction provides laboratory white light interferograms simultaneously with photometric calibration. In order to increase the interferometric signal without loss of photometric output, we propose to replace symmetric Y-junctions by asymmetric ones. In this paper, we report the conception, the manufacturing and the characterization of asymmetric Y-junction realized by ion exchange on glass substrate. The specific application of astronomical interferometry required the characterization of such component in term of spectral behavior, so we report the simulation and the measurement of asymmetric Y-junction response versus wavelength.

Piezo Voltage Controlled Planar Hall Effect Devices

PubMed Central

Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K. W.; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

2016-01-01

The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials. PMID:27329068

Piezo Voltage Controlled Planar Hall Effect Devices.

PubMed

Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K W; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

2016-06-22

The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

PET/MRI of Hepatic 90Y Microsphere Deposition Determines Individual Tumor Response

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

Fowler, Kathryn J.; Maughan, Nichole M.; Laforest, Richard

PurposeThe purpose of our study is to determine if there is a relationship between dose deposition measured by PET/MRI and individual lesion response to yttrium-90 ({sup 90}Y) microsphere radioembolization.Materials and Methods26 patients undergoing lobar treatment with {sup 90}Y microspheres underwent PET/MRI within 66 h of treatment and had follow-up imaging available. Adequate visualization of tumor was available in 24 patients, and contours were drawn on simultaneously acquired PET/MRI data. Dose volume histograms (DVHs) were extracted from dose maps, which were generated using a voxelized dose kernel. Similar contours to capture dimensional and volumetric change of tumors were drawn on follow-up imaging.more » Response was analyzed using both RECIST and volumetric RECIST (vRECIST) criteria.ResultsA total of 8 hepatocellular carcinoma (HCC), 4 neuroendocrine tumor (NET), 9 colorectal metastases (CRC) patients, and 3 patients with other metastatic disease met inclusion criteria. Average dose was useful in predicting response between responders and non-responders for all lesion types and for CRC lesions alone using both response criteria (p < 0.05). D70 (minimum dose to 70 % of volume) was also useful in predicting response when using vRECIST. No significant trend was seen in the other tumor types. For CRC lesions, an average dose of 29.8 Gy offered 76.9 % sensitivity and 75.9 % specificity for response.ConclusionsPET/MRI of {sup 90}Y microsphere distribution showed significantly higher DVH values for responders than non-responders in patients with CRC. DVH analysis of {sup 90}Y microsphere distribution following treatment may be an important predictor of response and could be used to guide future adaptive therapy trials.« less

Inflammation-induced synergetic enhancement of nanoparticle treatments with DOXIL® and 90Y-Lactosome for orthotopic mammary tumor

NASA Astrophysics Data System (ADS)

Kurihara, Kensuke; Ueda, Motoki; Hara, Isao; Hara, Eri; Sano, Kohei; Makino, Akira; Ozeki, Eiichi; Yamamoto, Fumihiko; Saji, Hideo; Togashi, Kaori; Kimura, Shunsaku

2016-05-01

Polymeric micelles (Lactosome) in the size of 20-30 nm were labeled with radionuclides of 111In (111In-DOTA-Lactosome) for SPECT imaging and 90Y (90Y-DOTA-Lactosome) for β-ray irradiation for mammary tumor in mice. The tumor site at the femoral right leg grafted with 4T1 cells was clearly imaged at 24 h after the intravenous injection. Biodistribution revealed that the half-life time of 111In-DOTA-Lactosome was 11 h, which enabled the nanoparticle selectively accumulated in tumor site due to the enhanced permeability and retention (EPR) effect. The anti-tumor therapeutic effect of 90Y-DOTA-Lactosome was observed depending on the dose frequency and amount. Under the condition of the percutaneous ethanol injection treatment, the therapeutic effect of 90Y-DOTA-Lactosome was enhanced due to the super EPR effect. Owing to the super EPR effect, co-administration of 90Y-DOTA-Lactosome and DOXIL® inhibited the tumor growth during 15 days with their administrations.

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.

Partition Model-Based 99mTc-MAA SPECT/CT Predictive Dosimetry Compared with 90Y TOF PET/CT Posttreatment Dosimetry in Radioembolization of Hepatocellular Carcinoma: A Quantitative Agreement Comparison.

PubMed

Gnesin, Silvano; Canetti, Laurent; Adib, Salim; Cherbuin, Nicolas; Silva Monteiro, Marina; Bize, Pierre; Denys, Alban; Prior, John O; Baechler, Sebastien; Boubaker, Ariane

2016-11-01

90 Y-microsphere selective internal radiation therapy (SIRT) is a valuable treatment in unresectable hepatocellular carcinoma (HCC). Partition-model predictive dosimetry relies on differential tumor-to-nontumor perfusion evaluated on pretreatment 99m Tc-macroaggregated albumin (MAA) SPECT/CT. The aim of this study was to evaluate agreement between the predictive dosimetry of 99m Tc-MAA SPECT/CT and posttreatment dosimetry based on 90 Y time-of-flight (TOF) PET/CT. We compared the 99m Tc-MAA SPECT/CT results for 27 treatment sessions (25 HCC patients, 41 tumors) with 90 Y SIRT (7 glass spheres, 20 resin spheres) and the posttreatment 90 Y TOF PET/CT results. Three-dimensional voxelized dose maps were computed from the 99m Tc-MAA SPECT/CT and 90 Y TOF PET/CT data. Mean absorbed dose ([Formula: see text]) was evaluated to compute the predicted-to-actual dose ratio ([Formula: see text]) in tumor volumes (TVs) and nontumor volumes (NTVs) for glass and resin spheres. The Lin concordance ([Formula: see text]) was used to measure accuracy ([Formula: see text]) and precision (ρ). Administered activity ranged from 0.8 to 1.9 GBq for glass spheres and from 0.6 to 3.4 GBq for resin spheres, and the respective TVs ranged from 2 to 125 mL and from 6 to 1,828 mL. The mean dose [Formula: see text] was 240 Gy for glass and 122 Gy for resin in TVs and 72 Gy for glass and 47 Gy for resin in NTVs. [Formula: see text] was 1.46 ± 0.58 (0.65-2.53) for glass and 1.16 ± 0.41 (0.54-2.54) for resin, and the respective values for [Formula: see text] were 0.88 ± 0.15 (0.56-1.00) and 0.86 ± 0.2 (0.58-1.35). DR variability was substantially lower in NTVs than in TVs. The Lin concordance between [Formula: see text] and [Formula: see text] (resin) was significantly better for tumors larger than 150 mL than for tumors 150 mL or smaller ([Formula: see text] = 0.93 and [Formula: see text] = 0.95 vs. [Formula: see text] = 0.57 and [Formula: see text] = 0.93; P < 0.05). In 90 Y radioembolization

Process improvement for the safe delivery of multidisciplinary-executed treatments-A case in Y-90 microspheres therapy.

PubMed

Cai, Bin; Altman, Michael B; Garcia-Ramirez, Jose; LaBrash, Jason; Goddu, S Murty; Mutic, Sasa; Parikh, Parag J; Olsen, Jeffrey R; Saad, Nael; Zoberi, Jacqueline E

To develop a safe and robust workflow for yttrium-90 (Y-90) radioembolization procedures in a multidisciplinary team environment. A generalized Define-Measure-Analyze-Improve-Control (DMAIC)-based approach to process improvement was applied to a Y-90 radioembolization workflow. In the first DMAIC cycle, events with the Y-90 workflow were defined and analyzed. To improve the workflow, a web-based interactive electronic white board (EWB) system was adopted as the central communication platform and information processing hub. The EWB-based Y-90 workflow then underwent a second DMAIC cycle. Out of 245 treatments, three misses that went undetected until treatment initiation were recorded over a period of 21 months, and root-cause-analysis was performed to determine causes of each incident and opportunities for improvement. The EWB-based Y-90 process was further improved via new rules to define reliable sources of information as inputs into the planning process, as well as new check points to ensure this information was communicated correctly throughout the process flow. After implementation of the revised EWB-based Y-90 workflow, after two DMAIC-like cycles, there were zero misses out of 153 patient treatments in 1 year. The DMAIC-based approach adopted here allowed the iterative development of a robust workflow to achieve an adaptable, event-minimizing planning process despite a complex setting which requires the participation of multiple teams for Y-90 microspheres therapy. Implementation of such a workflow using the EWB or similar platform with a DMAIC-based process improvement approach could be expanded to other treatment procedures, especially those requiring multidisciplinary management. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

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.

A look at 15 years of planar thallium-201 imaging

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

Kaul, S.

1989-09-01

Extensive experience has been accumulated over the past 15 years regarding planar thallium-201 imaging. Quantitation of technically superior images provides a high sensitivity and specificity for the detection of CAD. In addition, planar thallium-201 images provide very important prognostic information in different clinical situations. Although single photon emission computerized tomography offers potential theoretical advantages over planar imaging, because of the problems involved in reconstruction, specifically the creation of artifacts, it may not be the ideal imaging modality in all situations. Good quality planar thallium-201 imaging still has an important role in clinical cardiology today. 144 references.

(90)Y microspheres prepared by sol-gel method, promising medical material for radioembolization of liver malignancies.

PubMed

Łada, Wiesława; Iller, Edward; Wawszczak, Danuta; Konior, Marcin; Dziel, Tomasz

2016-10-01

A new technology for the production of radiopharmaceutical (90)Y microspheres in the form of spherical yttrium oxide grains obtained by sol-gel method has been described. The authors present and discuss the results of investigations performed in the development of new production technology of yttrium microspheres and determination of their physic-chemical properties. The final product has the structure of spherical yttrium oxide grains with a diameter 25-100μm, is stable and free from contaminants. Irradiation of 20mg samples of grains with diameter of 20-50μm in the thermal neutron flux of 1.7×10(14)cm(-2)s(-1) at the core of MARIA research nuclear reactor allowed to obtain microspheres labelled with the (90)Y isotope on the way of the nuclear reaction (89)Y(n, ɤ)(90)Y. Specific activity of irradiated microspheres has been determined by application of absolute triple to double coincidence ratio method (TDCR) and has been evaluated at 190MBq/mg Y. (90)Y microspheres prepared by the proposed technique can be regarded as a promising medical material for radioembolization of liver malignancies. Copyright © 2016 Elsevier B.V. All rights reserved.

Prognostic significance of normal quantitative planar thallium-201 stress scintigraphy in patients with chest pain

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

Wackers, F.J.; Russo, D.J.; Russo, D.

The prognostic significance of normal quantitative planar thallium-201 stress scintigraphy was evaluated in patients with a chest pain syndrome. The prevalence of cardiac events during follow-up was related to the pretest (that is, before stress scintigraphy) likelihood of coronary artery disease determined on the basis of symptoms, age, sex and stress electrocardiography. In a consecutive series of 344 patients who had adequate thallium-201 stress scintigrams, 95 had unequivocally normal studies by quantitative analysis. The pretest likelihood of coronary artery disease in the 95 patients had a bimodal distribution. During a mean follow-up period of 22 +/- 3 months, no patientmore » died. Three patients (3%) had a cardiac event: two of these patients (pretest likelihood of coronary artery disease 54 and 94%) had a nonfatal myocardial infarction 8 and 22 months, respectively, after stress scintigraphy, and one patient (pretest likelihood 98%) underwent percutaneous transluminal coronary angioplasty 16 months after stress scintigraphy for persisting anginal complaints. Three patients were lost to follow-up; all three had a low pretest likelihood of coronary artery disease. It is concluded that patients with chest pain and normal findings on quantitative thallium-201 scintigraphy have an excellent prognosis. Cardiac events are rare (infarction rate 1% per year) and occur in patients with a moderate to high pretest likelihood of coronary artery disease.« less

Large-scale purification of 90Sr from nuclear waste materials for production of 90Y, a therapeutic medical radioisotope.

PubMed

Wester, Dennis W; Steele, Richard T; Rinehart, Donald E; DesChane, Jaquetta R; Carson, Katharine J; Rapko, Brian M; Tenforde, Thomas S

2003-07-01

A major limitation on the supply of the short-lived medical isotope 90Y (t1/2 = 64 h) is the available quantity of highly purified 90Sr generator material. A radiochemical production campaign was therefore undertaken to purify 1,500 Ci of 90Sr that had been isolated from fission waste materials. A series of alkaline precipitation steps removed all detectable traces of 137Cs, alpha emitters, and uranium and transuranic elements. Technical obstacles such as the buildup of gas pressure generated upon mixing large quantities of acid with solid 90Sr carbonate were overcome through safety features incorporated into the custom-built equipment used for 90Sr purification. Methods are described for analyzing the chemical and radiochemical purity of the final product and for accurately determining by gravimetry the quantities of 90Sr immobilized on stainless steel filters for future use.

The origin and reduction of spurious extrahepatic counts observed in 90Y non-TOF PET imaging post radioembolization

NASA Astrophysics Data System (ADS)

Walrand, Stephan; Hesse, Michel; Jamar, François; Lhommel, Renaud

2018-04-01

Our literature survey revealed a physical effect unknown to the nuclear medicine community, i.e. internal bremsstrahlung emission, and also the existence of long energy resolution tails in crystal scintillation. None of these effects has ever been modelled in PET Monte Carlo (MC) simulations. This study investigates whether these two effects could be at the origin of two unexplained observations in 90Y imaging by PET: the increasing tails in the radial profile of true coincidences, and the presence of spurious extrahepatic counts post radioembolization in non-TOF PET and their absence in TOF PET. These spurious extrahepatic counts hamper the microsphere delivery check in liver radioembolization. An acquisition of a 32P vial was performed on a GSO PET system. This is the ideal setup to study the impact of bremsstrahlung x-rays on the true coincidence rate when no positron emission and no crystal radioactivity are present. A MC simulation of the acquisition was performed using Gate-Geant4. MC simulations of non-TOF PET and TOF-PET imaging of a synthetic 90Y human liver radioembolization phantom were also performed. Internal bremsstrahlung and long energy resolution tails inclusion in MC simulations quantitatively predict the increasing tails in the radial profile. In addition, internal bremsstrahlung explains the discrepancy previously observed in bremsstrahlung SPECT between the measure of the 90Y bremsstrahlung spectrum and its simulation with Gate-Geant4. However the spurious extrahepatic counts in non-TOF PET mainly result from the failure of conventional random correction methods in such low count rate studies and poor robustness versus emission-transmission inconsistency. A novel proposed random correction method succeeds in cleaning the spurious extrahepatic counts in non-TOF PET. Two physical effects not considered up to now in nuclear medicine were identified to be at the origin of the unusual 90Y true coincidences radial profile. TOF reconstruction removing

Preparation and dosimetry evaluation of a carrier- free 90Y labeled DOTMP as a Promising Agent for Bone marrow ablation.

PubMed

Salek, Nafise; Vosoghi, Sara; Arani, Simindokht Shirvani; Samani, Ali Bahrami; Mehrabi, Mohsen; Maraghe, Mohammad Ghannadi

2018-04-12

Skeletal uptake of 90Y-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetramethylene-phosphonate (DOTMP) is used to deliver high doses of this radiopharmaceutical to the bone marrow. In this research, carrier-free (c.f.) 90Y was obtained from an electrochemical 90Sr/90Y generator. The c.f. 90Y was mixed with 300 µL of DOTMP (20 mg/mL) and incubated under stirring conditions at room temperature for 45 min. The [90Y]Y-DOTMP that was obtained under optimized reaction conditions had the high radiochemical purities (>98%). Moreover, the radiolabeled complex exhibited excellent stability at room temperature, as well as in human serum. The biodistribution studies in rats showed the favorable selective skeletal uptake with rapid clearance from the blood, albeit with insignificant accumulation of activity in other non-target organs for the radiolabeled complex. Also the present work has utilized the Monte Carlo codes MCNP-4C to simulate the depth dose profile for 90Y in a mice femur bone and compared with that produced by 153Sm and 177Lu. The results show that the absorbed dose produced by 90Y in the bone marrow is higher than 153Sm and 177Lu per 1MBq of the injected activity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

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

Planar Inlet Design and Analysis Process (PINDAP)

NASA Technical Reports Server (NTRS)

Slater, John W.; Gruber, Christopher R.

2005-01-01

The Planar Inlet Design and Analysis Process (PINDAP) is a collection of software tools that allow the efficient aerodynamic design and analysis of planar (two-dimensional and axisymmetric) inlets. The aerodynamic analysis is performed using the Wind-US computational fluid dynamics (CFD) program. A major element in PINDAP is a Fortran 90 code named PINDAP that can establish the parametric design of the inlet and efficiently model the geometry and generate the grid for CFD analysis with design changes to those parameters. The use of PINDAP is demonstrated for subsonic, supersonic, and hypersonic inlets.

Quantitative separation of the anisotropic magnetothermopower and planar Nernst effect by the rotation of an in-plane thermal gradient

NASA Astrophysics Data System (ADS)

Reimer, Oliver; Meier, Daniel; Bovender, Michel; Helmich, Lars; Dreessen, Jan-Oliver; Krieft, Jan; Shestakov, Anatoly S.; Back, Christian H.; Schmalhorst, Jan-Michael; Hütten, Andreas; Reiss, Günter; Kuschel, Timo

2017-01-01

A thermal gradient as the driving force for spin currents plays a key role in spin caloritronics. In this field the spin Seebeck effect (SSE) is of major interest and was investigated in terms of in-plane thermal gradients inducing perpendicular spin currents (transverse SSE) and out-of-plane thermal gradients generating parallel spin currents (longitudinal SSE). Up to now all spincaloric experiments employ a spatially fixed thermal gradient. Thus, anisotropic measurements with respect to well defined crystallographic directions were not possible. Here we introduce a new experiment that allows not only the in-plane rotation of the external magnetic field, but also the rotation of an in-plane thermal gradient controlled by optical temperature detection. As a consequence, the anisotropic magnetothermopower and the planar Nernst effect in a permalloy thin film can be measured simultaneously. Thus, the angular dependence of the magnetothermopower with respect to the magnetization direction reveals a phase shift, that allows the quantitative separation of the thermopower, the anisotropic magnetothermopower and the planar Nernst effect.

SU-E-T-402: Y-90 Microspheres (SIR Spheres) for Treatment of Liver Metastasis : Technique

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

Nair, M

2014-06-01

Purpose: The purpose of this presentation is to discuss the radiation safety and dosimetric technique used for the therapeutic procedure using Y-90 microspheres through intra -arterial administration on patients with liver metastasis Methods: The radiation dosimetry, technique and safety aspects of 14 patients with primary and metastatic liver cancer, treated with Y-90 microsphere (SIR spheres) are discussed. The liver and tumor volumes were determined using the CT and MR scans . The images were imported into the treatment planning system and the liver and tumor volumes and the volume of the liver affected were outlined and the volume calculation wasmore » performed using the software. The lung shunt fraction (LSF) and tumor to liver uptake ratio (TLR) were determined using the nuclear medicine SPECT imaging with Tc-99m MAA. The absorbed dose to the target volume in liver was calculated using the following equation:Dose ? (Gy) = C x E? x 5.92 x 10-6 (Gy/s) x T(1/2)(days) x 1.44 x 8.64 x 104 (s) The distribution of activity in the tumor bed was confirmed by post Y-90 administration imaging using the Bremsstrahlung peak at 30% window. The patient and the procedure room were surveyed and radiation safety instructions were given to the patient Results: The tumor volume ranged from 77 cc to 700 cc, tumor to liver uptake ranged from 3 to 12. The lung shunt fraction varied from 1.08% to 9.0%. The activity administered ranged from 1.0GBq to 2.5 GBq, . The radiation survey in contact with the patient ranged from 1.8 mR/hr to 2.5 mR/hr and reading at 1 meter was less than 0.2 mR/hr Conclusion: The technique for radiation dosimetry and radiation safety for Y-90 microsphere therapy is established. The post treatment imaging helped to confirm the distribution of Y-90 microspheres inside the tumor bed.« less

Semi-Quantitative Analysis of Post-Transarterial Radioembolization (90)Y Microsphere Positron Emission Tomography Combined with Computed Tomography (PET/CT) Images in Advanced Liver Malignancy: Comparison With (99m)Tc Macroaggregated Albumin (MAA) Single Photon Emission Computed Tomography (SPECT).

PubMed

Rhee, Seunghong; Kim, Sungeun; Cho, Jaehyuk; Park, Jukyung; Eo, Jae Seon; Park, Soyeon; Lee, Eunsub; Kim, Yun Hwan; Choe, Jae-Gol

2016-03-01

The purpose of this study is to evaluate the correlation between pretreatment planning technetium-99m ((99m)Tc) macroaggregated albumin (MAA) SPECT images and posttreatment transarterial radioembolization (TARE) yttirum-90 ((90)Y) PET/CT images by comparing the ratios of tumor-to-normal liver counts. Fifty-two patients with advanced hepatic malignancy who underwent (90)Y microsphere radioembolization from January 2010 to December 2012 were retrospectively reviewed. Patients had undergone (99m)Tc MAA intraarterial injection SPECT for a pretreatment evaluation of microsphere distribution and therapy planning. After the administration of (90)Y microspheres, the patients underwent posttreatment (90)Y PET/CT within 24 h. For semiquantitative analysis, the tumor-to-normal uptake ratios in (90)Y PET/CT (TNR-yp) and (99m)Tc MAA SPECT (TNR-ms) as well as the tumor volumes measured in angiographic CT were obtained and analyzed. The relationship of TNR-yp and TNR-ms was evaluated by Spearman's rank correlation and Wilcoxon's matched pairs test. In a total of 79 lesions of 52 patients, the distribution of microspheres was well demonstrated in both the SPECT and PET/CT images. A good correlation was observed of between TNR-ms and TNR-yp (rho value = 0.648, p < 0.001). The TNR-yp (median 2.78, interquartile range 2.43) tend to show significantly higher values than TNR-ms (median 2.49, interquartile range of 1.55) (p = 0.012). The TNR-yp showed weak correlation with tumor volume (rho = 0.230, p = 0.041). The (99m)Tc MAA SPECT showed a good correlation with (90)Y PET/CT in TNR values, suggesting that (99m)Tc MAA can be used as an adequate pretreatment evaluation method. However, the (99m)Tc MAA SPECT image consistently shows lower TNR values compared to (90)Y PET/CT, which means the possibility of underestimation of tumorous uptake in the partition dosimetry model using (99m)Tc MAA SPECT. Considering that (99m)Tc MAA is the only clinically available surrogate

Dosimetry by 90Y internal pair production PET imaging after liver radioembolization: How well can we quantify the absorbed dose to lesions?

NASA Astrophysics Data System (ADS)

D'Arienzo, M.

2017-03-01

Radioembolization is a catheter-based liver-directed therapy indicated mainly in a palliative setting for primary and secondary hepatic malignancies. It involves the administration of 90Y -loaded microspheres in the arterial vasculature of the liver by use of percutaneous transarterial techniques. Previous studies showed that the decay of 90Y has a minor branch to the 0+ first excited state of 90Zr at 1.76MeV, that is followed by a β+ / β- emission. In recent years, a number of authors have used the small positronic emission of 90Y , (3.186± 0.047)\\cdot 10^{-5} , to obtain high-resolution positron emission tomography (PET) images of 90Y biodistribution after liver radioembolization. At present, it is generally accepted that the possibility of detecting β+ emissions from 90Y by PET scanners may pave the way for an accurate patient-specific dosimetry. The present paper has a twofold purpose. Firstly, a brief overview of imaging modalities currently used to assess microsphere biodistribution after liver radioembolization is presented. Secondly, the paper focuses on 90Y -PET dosimetry. A benchmark between a number of dosimetric approaches for accurate dosimetry after liver radioembolization with 90Y -PET dosimetry is presented.

Fundamental and practical limits of planar tracking solar concentrators.

PubMed

Grede, Alex J; Price, Jared S; Giebink, Noel C

2016-12-26

Planar microtracking provides an alternate paradigm for solar concentration that offers the possibility of realizing high-efficiency embedded concentrating photovoltaic systems in the form factor of standard photovoltaic panels. Here, we investigate the thermodynamic limit of planar tracking optical concentrators and establish that they can, in principal, achieve the sine limit of their orientationally-tracked counterparts provided that the receiver translates a minimum distance set by the field of view half-angle. We develop a phase space methodology to optimize practical planar tracking concentrators and apply it to the design of a two surface, catadioptric system that operates with > 90% optical efficiency over a 140° field of view at geometric gains exceeding 1000×. These results provide a reference point for subsequent developments in the field and indicate that planar microtracking can achieve the high optical concentration ratio required in commercial concentrating photovoltaic systems.

p53-Based Strategy for Protection of Bone Marrow From Y-90 Ibritumomab Tiuxetan

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

Su, Hang, E-mail: suh3@uthscsa.edu; Ganapathy, Suthakar; Li, Xiaolei

Purpose: The main drawbacks of radioimmunotherapy have been severe hematological toxicity and potential development of myelodysplastic syndrome and secondary leukemia. Activation of p53 follows a major pathway by which normal tissues respond to DNA-damaging agents, such as chemotherapy and radiation therapy, that result in injuries and pathological consequences. This pathway is separate from the tumor suppressor pathway of p53. We have previously reported that use of low-dose arsenic (LDA) temporarily and reversibly suppresses p53 activation, thereby ameliorating normal tissue toxicity from exposure to 5-fluorouracil and X rays. We have also demonstrated that LDA-mediated protection requires functional p53 and thus ismore » selective to normal tissues, as essentially every cancer cell has dysfunctional p53. Here we tested the protective efficacy of LDA for bone marrow tissue against radioimmunotherapy through animal experiments. Methods and Materials: Mice were subjected to LDA pretreatment for 3 days, followed by treatment with Y-90 ibritumomab tiuxetan. Both dose course (10, 25, 50, 100, and 200 μCi) and time course (6, 24, and 72 hours and 1 and 2 weeks) experiments were performed. The response of bone marrow cells to LDA was determined by examining the expression of NFκB, Glut1, and Glut3. Staining with hematoxylin and eosin, γ-H2AX, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was used to examine morphology, DNA damage response, and apoptotic cell populations. Results: Elevated levels of NFκB, Glut1, and Glut3 were observed in bone marrow cells after LDA treatment. Bone marrow damage levels induced by Y-90 ibritumomab tiuxetan were greatly reduced by LDA pretreatment. Consistent with this observation, significantly less DNA damage and fewer apoptotic cells were accumulated after Y-90 ibritumomab tiuxetan treatment in LDA-pretreated mice. Furthermore, in the mouse xenograft model implanted with human Karpas-422 lymphoma

THERAPY OF POLYCYTHEMIA VERA WITH RADIOYTTRIUM (Y-90)

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

Greenburg, J.; Sawitsky, A.; Dudley, H.C.

1962-01-01

BS>Nine patients with polycythemia vera were treated from 5-l7 months ago with a single intravenous injection of chelated radioactive yttrium (Y-90) in dosages ranging from 0.l0 to 0.25 mc/kg of body weight. An excellent response, both clinical and hematologic, was obtained in all the patients. This includes relief of symptoms, regression of organomegaly, and normalization of the hematologic picture. Two of these patients, treated l6 and 9 months ago, may possibly be going into relapse. The others are continuing in essentially complete remission. Toxicity was limtted to transient petechiosis and epistaxis, from which recovery was spontaneous. (auth)

Analysis and Synthesis of Leaky-Wave Devices in Planar Technology

NASA Astrophysics Data System (ADS)

Martinez Ros, Alejandro Javier

The work developed along this doctoral thesis has been focused on the analysis and synthesis of microwave devices in planar technology. In particular, several types of devices based on the radiation mechanism of leaky waves have been studied. Typically, the radiation properties in leaky-wave devices are determined by the complex propagation constant of the leaky mode, wherein the phase constant is responsible for the pointing angle and the leakage rate for the intensity of the radiated fields. In this manner, by controlling both amplitude and phase of the leaky mode, an effective control over the device's radiation diagram can be obtained. Moreover, with the purpose of efficiently obtaining the leaky mode's radiation properties as function of the main geometrical parameters of the structure, several modal tools based on the transverse resonance analysis of the structure have been performed. In order to demonstrate this simultaneous control over the complex propagation constant in planar technology, several types of leaky-wave devices, including antennas (LWAs), multiplexors and near-field focusing systems, have been designed and manufactured in the technology of substrate integrated waveguide (SIW). This recently proposed technology, allows the design of devices based on classical waveguide technology with standard manufacturing techniques used for printed circuit board (PCB) designs. In this way, most of the parts that form a communication system can be integrated into a single substrate, thus reducing its cost and providing a more robust and compact device, which has less losses compared to other planar technologies such as the microstrip. El trabajo llevado a cabo durante la realizacion de esta tesis doctoral, se ha centrado en el analisis y sintesis de dispositivos de microondas en tecnologia planar. En concreto, se han estudiado diferentes tipos de dispositivos basados en radiacion por ondas de fuga "leaky waves", en los cuales las propiedades de radiacion

Computed tomography hepatic arteriography has a hepatic falciform artery detection rate that is much higher than that of digital subtraction angiography and 99mTc-MAA SPECT/CT: implications for planning 90Y radioembolization?

PubMed

Burgmans, M C; Too, C W; Kao, Y H; Goh, A S W; Chow, P K H; Tan, B S; Tay, K H; Lo, R H G

2012-12-01

To compare the hepatic falciform artery (HFA) detection rates of digital subtraction angiography (DSA), computed tomography hepatic arteriography (CTHA) and 99mTc-macroaggregated albumin (99mTc-MAA) single photon emission computed tomography with integrated CT (SPECT/CT) and to correlate HFA patency with complication rates of yttrium-90 (90Y) radioembolization. From August 2008 to November 2010, 79 patients (range 23-83 years, mean 62.3 years; 67 male) underwent pre-treatment DSA, CTHA and 99mTc-MAA scintigraphy (planar/SPECT/CT) to assess suitability for radioembolization with 90Y resin microspheres. Thirty-seven patients were excluded from the study, because CTHA was performed with a catheter position that did not result in opacification of the liver parenchyma adjacent to the falciform ligament. DSA, CTHA and 99mTc-MAA SPECT/CT images and medical records were retrospectively reviewed. A patent HFA was detected in 22 of 42 patients (52.3%). The HFA detection rates of DSA, CTHA and 99mTc-MAA SPECT/CT were 11.9%, 52.3% and 13.3%, respectively (p<0.0001). An origin from the segment 4 artery was seen in 51.7% of HFAs. Prophylactic HFA coil-embolization prior to 90Y microspheres infusion was performed in 2 patients. Of the patients who underwent radioembolization with a patent HFA, none developed supra-umbilical radiation dermatitis. One patient experienced epigastric pain attributed to post-embolization syndrome and was managed conservatively. The HFA detection rate of CTHA is superior to that of DSA and 99mTc-MAA SPECT/CT. Complications related to non-target radiation of the HFA vascular territory rarely occur, even in patients undergoing radioembolization with a patent HFA. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Spin-flip isovector giant resonances from the 90Zr(n,p)90Y reaction at 198 MeV

NASA Astrophysics Data System (ADS)

Raywood, K. J.; Spicer, B. M.; Yen, S.; Long, S. A.; Moinester, M. A.; Abegg, R.; Alford, W. P.; Celler, A.; Drake, T. E.; Frekers, D.; Green, P. E.; Häusser, O.; Helmer, R. L.; Henderson, R. S.; Hicks, K. H.; Jackson, K. P.; Jeppesen, R. G.; King, J. D.; King, N. S.; Miller, C. A.; Officer, V. C.; Schubank, R.; Shute, G. G.; Vetterli, M.; Watson, J.; Yavin, A. I.

1990-06-01

Doubly differential cross sections of the reaction 90Zr(n,p)90Y have been measured at 198 MeV for excitations up to 38 MeV in the residual nucleus. An overall resolution of 1.3 MeV was achieved. The spectra show qualitative agreement in shape and magnitude with recent random phase approximation calculations; however, all of the calculations underestimate the high excitation region of the spectra. A multipole decomposition of the data has been performed using differential cross sections calculated in the distorted-wave impulse approximation. An estimate of the Gamow-Teller strength in the reaction is given. The isovector spin-flip dipole giant resonance has been identified and there is also an indication of isovector monopole strength.

Fractionated Radioimmunotherapy With 90Y-Clivatuzumab Tetraxetan and Low-Dose Gemcitabine Is Active in Advanced Pancreatic Cancer

PubMed Central

Ocean, Allyson J.; Pennington, Kenneth L.; Guarino, Michael J.; Sheikh, Arif; Bekaii-Saab, Tanios; Serafini, Aldo N.; Lee, Daniel; Sung, Max W.; Gulec, Seza A.; Goldsmith, Stanley J.; Manzone, Timothy; Holt, Michael; O’Neil, Bert H.; Hall, Nathan; Montero, Alberto J.; Kauh, John; Gold, David V.; Horne, Heather; Wegener, William A.; Goldenberg, David M.

2014-01-01

BACKGROUND It has been demonstrated that the humanized clivatuzumab tetraxetan (hPAM4) antibody targets pancreatic ductal carcinoma selectively. After a trial of radioimmunotherapy that determined the maximum tolerated dose of single-dose yttrium-90-labeled hPAM4 (90Y-hPAM4) and produced objective responses in patients with advanced pancreatic ductal carcinoma, the authors studied fractionated radioimmunotherapy combined with low-dose gemcitabine in this disease. METHODS Thirty-eight previously untreated patients (33 patients with stage IV disease and 5 patients with stage III disease) received gemcitabine 200 mg/m2 weekly for 4 weeks with 90Y-hPAM4 given weekly in Weeks 2, 3, and 4 (cycle 1), and the same cycle was repeated in 13 patients (cycles 2–4). In the first part of the study, 19 patients received escalating weekly 90Y doses of 6.5 mCi/m2, 9.0 mCi/m2, 12.0 mCi/m2, and 15.0 mCi/m2. In the second portion, 19 additional patients received weekly doses of 9.0 mCi/m2 or 12.0 mCi/m2. RESULTS Grade 3/4 thrombocytopenia or neutropenia (according to version 3.0 of the National Cancer Institute’s Common Terminology Criteria for Adverse Events) developed in 28 of 38 patients after cycle 1 and in all retreated patients; no grade >3 nonhematologic toxicities occurred. Fractionated dosing of cycle 1 allowed almost twice the radiation dose compared with single-dose radioimmunotherapy. The maximum tolerated dose of 90Y-hPAM4 was 12.0 mCi/m2 weekly for 3 weeks for cycle 1, with ≤9.0 mCi/m2 weekly for 3 weeks for subsequent cycles, and that dose will be used in future trials. Six patients (16%) had partial responses according to computed tomography-based Response Evaluation Criteria in Solid Tumors, and 16 patients (42%) had stabilization as their best response (58% disease control). The median overall survival was 7.7 months for all 38 patients, including 11.8 months for those who received repeated cycles (46% [6 of 13 patients] ≥1 year), with improved efficacy at

Catadioptric planar compound eye with large field of view.

PubMed

Deng, Huaxia; Gao, Xicheng; Ma, Mengchao; Li, Yunyang; Li, Hang; Zhang, Jin; Zhong, Xiang

2018-05-14

The planar compound eye has the advantages of simple structure and no requirement for complex relay optical elements, but the field of view (FOV) is very difficult to expand. Overcoming the limitation of FOV, especially with simple structures, is a great challenge for the development of planar compound eyes. Different from the existing designs that only considering refraction, this article proposes a catadioptric planar compound eye based on the reflection and refraction to expand the FOV. In the proposed design, the incident light from a large angle is reflected into the lenslet array by two rotationally symmetric mirrors whose surface equations are optimized by mathematical and optical softwares. The FOV of the proposed catadioptric planar compound eye theoretically can reach 96.6°, which is much wider than the opening record of 70°. Moreover, no distortion of the imaging system can be obtained theoretically in this design. Simulation results show a linearity of better than 99% for the most of the incident angles. The verification experiments show that the FOV of the proposed device can reach 90.7° while the FOV of the corresponding planar compound eye without mirrors is 41.6°. The proposed catadioptric planar compound eye has the great potential in monitoring, detection and virtual reality since the FOV has been widen significantly.

Multi-axis planar slide system

DOEpatents

Bieg, Lothar F.

2002-01-01

An apparatus for positioning an item that provides two-dimensional, independent orthogonal motion of a platform in a X-Y plane. A pair of master and slave disks engages opposite sides of the platform. Rotational drivers are connected to master disks so the disks rotate eccentrically about axes of rotation. Opposing slave disks are connected to master disks on opposite sides of the platform by a timing belt, or are electronically synchronized together using stepper motors, to effect coordinated motion. The coordinated eccentric motion of the pairs of master/slave disks compels smooth linear motion of the platform in the X-Y plane without backlash. The apparatus can be a planar mechanism implemented in a MEMS device.

Radioimmunotherapy of pancreatic cancer xenografts in nude mice using 90Y-labeled anti-α6β4 integrin antibody

PubMed Central

Aung, Winn; Tsuji, Atsushi B.; Sudo, Hitomi; Sugyo, Aya; Ukai, Yoshinori; Kouda, Katsushi; Kurosawa, Yoshikazu; Furukawa, Takako; Saga, Tsuneo

2016-01-01

The contribution of integrin α6β4 (α6β4) overexpression to the pancreatic cancer invasion and metastasis has been previously shown. We have reported immunotargeting of α6β4 for radionuclide-based and near-infrared fluorescence imaging in a pancreatic cancer model. In this study, we prepared yttrium-90 labeled anti-α6β4 antibody (90Y-ITGA6B4) and evaluated its radioimmunotherapeutic efficacy against pancreatic cancer xenografts in nude mice. Mice bearing xenograft tumors were randomly divided into 5 groups: (1) single administration of 90Y-ITGA6B4 (3.7MBq), (2) double administrations of 90Y-ITGA6B4 with once-weekly schedule (3.7MBq × 2), (3) single administration of unlabeled ITGA6B4, (4) double administrations of unlabeled ITGA6B4 with once-weekly schedule and (5) the untreated control. Biweekly tumor volume measurements and immunohistochemical analyses of tumors at 2 days post-administration were performed to monitor the response to treatments. To assess the toxicity, body weight was measured biweekly. Additionally, at 27 days post-administration, blood samples were collected through cardiac puncture, and hematological parameters, hepatic and renal functions were analyzed. Both 90Y-ITGA6B4 treatment groups showed reduction in tumor volumes (P < 0.04), decreased cell proliferation marker Ki-67-positive cells and increased DNA damage marker p-H2AX-positive cells, compared with the other groups. Mice treated with double administrations of 90Y-ITGA6B4, exhibited myelosuppression. There were no significant differences in hepatic and renal functions between the 2 treatment groups and the other groups. Our results suggest that 90Y-ITGA6B4 is a promising radioimmunotherapeutic agent against α6β4 overexpressing tumors. In the future studies, dose adjustment for fractionated RIT should be considered carefully in order to get the optimal effect while avoiding myelotoxicity. PMID:27246980

SU-F-T-687: Comparison of SPECT/CT-Based Methodologies for Estimating Lung Dose from Y-90 Radioembolization

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

Kost, S; Yu, N; Lin, S

2016-06-15

Purpose: To compare mean lung dose (MLD) estimates from 99mTc macroaggregated albumin (MAA) SPECT/CT using two published methodologies for patients treated with {sup 90}Y radioembolization for liver cancer. Methods: MLD was estimated retrospectively using two methodologies for 40 patients from SPECT/CT images of 99mTc-MAA administered prior to radioembolization. In these two methods, lung shunt fractions (LSFs) were calculated as the ratio of scanned lung activity to the activity in the entire scan volume or to the sum of activity in the lung and liver respectively. Misregistration of liver activity into the lungs during SPECT acquisition was overcome by excluding lungmore » counts within either 2 or 1.5 cm of the diaphragm apex respectively. Patient lung density was assumed to be 0.3 g/cm{sup 3} or derived from CT densitovolumetry respectively. Results from both approaches were compared to MLD determined by planar scintigraphy (PS). The effect of patient size on the difference between MLD from PS and SPECT/CT was also investigated. Results: Lung density from CT densitovolumetry is not different from the reference density (p = 0.68). The second method resulted in lung dose of an average 1.5 times larger lung dose compared to the first method; however the difference between the means of the two estimates was not significant (p = 0.07). Lung dose from both methods were statistically different from those estimated from 2D PS (p < 0.001). There was no correlation between patient size and the difference between MLD from PS and both SPECT/CT methods (r < 0.22, p > 0.17). Conclusion: There is no statistically significant difference between MLD estimated from the two techniques. Both methods are statistically different from conventional PS, with PS overestimating dose by a factor of three or larger. The difference between lung doses estimated from 2D planar or 3D SPECT/CT is not dependent on patient size.« less

High-precision planar magnetic levitation

NASA Astrophysics Data System (ADS)

Kim, Won-Jong

1997-11-01

This thesis presents the design and implementation of a high-precision magnetically levitated stage with large planar motion capability. This stage is the first which is capable of providing all the motions required for photolithography in semiconductor manufacturing with only one moving part, namely the platen. The platen is driven in all six-degree-of-freedom motions with small adjustments for focusing and alignment and with large planar motions for positioning across the wafer surface. The underlying electromechanical modeling and analysis, mechanical and electrical design, and real-time control of such a high-precision planar magnetic levitator are presented. The platen is levitated without contact by four novel permanent-magnet linear motors that provide both suspension and drive forces. The linear motors consist of Halbach-type magnet arrays attached to the underside of the levitated platen, and coil sets attached to the fixed machine platform. Since all the motor coils are fixed, no wires need to be connected to the moving part. The platen mass of 5.6 kg is supported against gravity by the combined forces of the four motors. Each motor consumes about 5.4 W to lift the platen. Two of the motors drive the stage in the x-direction, and the two other motors drive in the y-direction. The motor forces are coordinated appropriately to control the remaining four degrees of freedom. The present design has a travel of 50 mm in x and y, a travel of 400 μm in z, and is capable of milliradian-scale rotations about each of these three axes. The stage position in the plane is measured with three laser interferometers with sub-nanometer resolution. The stage position out of the plane is measured by three capacitance probes with nanometer resolution. The stage operates with a position noise of 5 nm rms in x and y, and is demonstrating acceleration capabilities in excess of 10 m/s2 (1 g). The control bandwidth of the system is 50 Hz. This design can readily be scaled to

Magnetically directed poly(lactic acid) [sup 90]Y-microspheres: Novel agents for targeted intracavitary radiotherapy

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

Haefeli, U.O.; Sweeney, S.M.; Beresford, B.A.

1994-08-01

High energy [beta]-emitting radioisotopes like Yttrium-90 have a radiotoxic range of about one centimeter. For cancer treatment they must be brought near the tumor cells and kept there for as long as they are radioactive. The authors developed as carriers for the ionic form of [sup 90]Y a matrix-type polymeric drug delivery system, poly(lactic acid) (PLA) microspheres. This radiopharmaceutical could be selectively delivered to the target site after incorporating 10% Fe[sub 3]O[sub 4] which made the magnetic microspheres (MMS) responsive to an external magnetic field. Furthermore, MMS are biodegradable and slowly hydrolyze into physiologic lactic acid after the radioactivity ismore » completely decayed. Previously prepared 10--40 [mu]m MMS were radiochemically loaded to high specific activity with [sup 90]Y at a pH of 5.7. Stability studies showed that approximately 95% of added [sup 90]Y is retained within the PLA matrix after 28 days (> 10 half-lives) at 37 C in serum, and electron microscopy showed that the microspheres retained their characteristic morphologic appearance for the same time period. Cytotoxicity studies with SK-N-SH neuroblastoma cells growing in monolayer showed that the radiocytotoxicity of the microspheres could be directed magnetically to either kill or spare specific cell populations, thus making them of great interest for targeted intracavitary tumor therapy. The authors are currently optimizing this system for use in the treatment of neoplastic meningitis.« less

Somatostatin-based radiotherapy with [90Y-DOTA]-TOC in neuroendocrine tumors: long-term outcome of a phase I dose escalation study.

PubMed

Marincek, Nicolas; Jörg, Ann-Catherine; Brunner, Philippe; Schindler, Christian; Koller, Michael T; Rochlitz, Christoph; Müller-Brand, Jan; Maecke, Helmut R; Briel, Matthias; Walter, Martin A

2013-01-15

We describe the long-term outcome after clinical introduction and dose escalation of somatostatin receptor targeted therapy with [90Y-DOTA]-TOC in patients with metastasized neuroendocrine tumors. In a clinical phase I dose escalation study we treated patients with increasing [90Y-DOTA]-TOC activities. Multivariable Cox regression and competing risk regression were used to compare efficacy and toxicities of the different dosage protocols. Overall, 359 patients were recruited; 60 patients were enrolled for low dose (median: 2.4 GBq/cycle, range 0.9-7.8 GBq/cycle), 77 patients were enrolled for intermediate dose (median: 3.3 GBq/cycle, range: 2.0-7.4 GBq/cycle) and 222 patients were enrolled for high dose (median: 6.7 GBq/cycle, range: 3.7-8.1 GBq/cycle) [90Y-DOTA]-TOC treatment. The incidences of hematotoxicities grade 1-4 were 65.0%, 64.9% and 74.8%; the incidences of grade 4/5 kidney toxicities were 8.4%, 6.5% and 14.0%, and the median survival was 39 (range: 1-158) months, 34 (range: 1-118) months and 29 (range: 1-113) months. The high dose protocol was associated with an increased risk of kidney toxicity (Hazard Ratio: 3.12 (1.13-8.59) vs. intermediate dose, p = 0.03) and a shorter overall survival (Hazard Ratio: 2.50 (1.08-5.79) vs. low dose, p = 0.03). Increasing [90Y-DOTA]-TOC activities may be associated with increasing hematological toxicities. The dose related hematotoxicity profile of [90Y-DOTA]-TOC could facilitate tailoring [90Y-DOTA]-TOC in patients with preexisting hematotoxicities. The results of the long-term outcome suggest that fractionated [90Y-DOTA]-TOC treatment might allow to reduce renal toxicity and to improve overall survival. (ClinicalTrials.gov number NCT00978211).

Radiopharmaceutical development based on human blood albumin microspheres and 90Y

NASA Astrophysics Data System (ADS)

Petriev, V. M.; Vlasova, O. P.; Postnov, A. A.; Epstein, N. B.

2017-01-01

New radiopharmaceutial (RP) based on human serum albumin microspheres (MSA) and 90Y was developed for treatment of liver cancer. The optimized synthesis using chelation resulted in approximately 80% yield with high specific activity. The RP developed was tested in mice with inoculated sarcoma-37. In two weeks the tumor size reduced by 43% after the treatment with the dose of 500 μCi injected into the tumor site.

Two solvable problems of planar geometrical optics.

PubMed

Borghero, Francesco; Bozis, George

2006-12-01

In the framework of geometrical optics we consider a two-dimensional transparent inhomogeneous isotropic medium (dispersive or not). We show that (i) for any family belonging to a certain class of planar monoparametric families of monochromatic light rays given in the form f(x,y)=c of any definite color and satisfying a differential condition, all the refractive index profiles n=n(x,y) allowing for the creation of the given family can be found analytically (inverse problem) and that (ii) for any member of a class of two-dimensional refractive index profiles n=n(x,y) satisfying a differential condition, all the compatible families of light rays can be found analytically (direct problem). We present appropriate examples.

Response, survival, and long-term toxicity after therapy with the radiolabeled somatostatin analogue [90Y-DOTA]-TOC in metastasized neuroendocrine cancers.

PubMed

Imhof, Anna; Brunner, Philippe; Marincek, Nicolas; Briel, Matthias; Schindler, Christian; Rasch, Helmut; Mäcke, Helmut R; Rochlitz, Christoph; Müller-Brand, Jan; Walter, Martin A

2011-06-10

To investigate response, survival, and safety profile of the somatostatin-based radiopeptide (90)yttrium-labeled tetraazacyclododecane-tetraacetic acid modified Tyr-octreotide ([(90)Y-DOTA]-TOC) in neuroendocrine cancers. In a clinical phase II single-center open-label trial, patients with neuroendocrine cancers were treated with repeated cycles of [(90)Y-DOTA]-TOC. Each cycle consisted of a single intravenous injection of 3.7GBq/m(2) body-surface [(90)Y-DOTA]-TOC. Additional cycles were withheld in case of tumor progression and/or permanent toxicity. Overall, 1,109 patients received 2,472 cycles of [(90)Y-DOTA]-TOC (median, two; range, one to 10 cycles per patient). Of the 1,109 patients, 378 (34.1%) experienced morphologic response; 172 (15.5%), biochemical response; and 329 (29.7%), clinical response. During a median follow-up of 23 months, 491 patients (44.3%) died. Longer survival was correlated with each: morphologic (hazard ratio [HR], 0.46; 95% CI, 0.38 to 0.56; median survival, 44.7 v 18.3 months; P < .001), biochemical (HR, 0.75; 95% CI, 0.59 to 0.96; 35.3 v 25.7 months; P = .023), and clinical response (HR, 0.68; 95% CI, 0.56 to 0.82; 36.8 v 23.5 months; P < .001). Overall, 142 patients (12.8%) developed grade 3 to 4 transient hematologic toxicities, and 103 patients (9.2%) experienced grade 4 to 5 permanent renal toxicity. Multivariable regression revealed that tumoral uptake in the initial imaging study was predictive for overall survival (HR, 0.45; 95% CI, 0.29 to 0.69; P < .001), whereas the initial kidney uptake was predictive for severe renal toxicity (HR, 1.59; 95% CI, 1.17 to 2.17; P = .003). This study documents the long-term outcome of [(90)Y-DOTA]-TOC treatment in a large cohort. Response to [(90)Y-DOTA]-TOC is associated with longer survival. Somatostatin receptor imaging is predictive for both survival after [(90)Y-DOTA]-TOC treatment and occurrence of renal toxicity.

SU-E-CAMPUS-I-06: Y90 PET/CT for the Instantaneous Determination of Both Target and Non-Target Absorbed Doses Following Hepatic Radioembolization

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

Pasciak, A; Kao, J

2014-06-15

Purpose The process of converting Yttrium-90 (Y90) PET/CT images into 3D absorbed dose maps will be explained. The simple methods presented will allow the medical physicst to analyze Y90 PET images following radioembolization and determine the absorbed dose to tumor, normal liver parenchyma and other areas of interest, without application of Monte-Carlo radiation transport or dose-point-kernel (DPK) convolution. Methods Absorbed dose can be computed from Y90 PET/CT images based on the premise that radioembolization is a permanent implant with a constant relative activity distribution after infusion. Many Y90 PET/CT publications have used DPK convolution to obtain 3D absorbed dose maps.more » However, this method requires specialized software limiting clinical utility. The Local Deposition method, an alternative to DPK convolution, can be used to obtain absorbed dose and requires no additional computer processing. Pixel values from regions of interest drawn on Y90 PET/CT images can be converted to absorbed dose (Gy) by multiplication with a scalar constant. Results There is evidence that suggests the Local Deposition method may actually be more accurate than DPK convolution and it has been successfully used in a recent Y90 PET/CT publication. We have analytically compared dose-volume-histograms (DVH) for phantom hot-spheres to determine the difference between the DPK and Local Deposition methods, as a function of PET scanner point-spread-function for Y90. We have found that for PET/CT systems with a FWHM greater than 3.0 mm when imaging Y90, the Local Deposition Method provides a more accurate representation of DVH, regardless of target size than DPK convolution. Conclusion Using the Local Deposition Method, post-radioembolization Y90 PET/CT images can be transformed into 3D absorbed dose maps of the liver. An interventional radiologist or a Medical Physicist can perform this transformation in a clinical setting, allowing for rapid prediction of treatment efficacy

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.

Gastric injury from (90)Y to left hepatic lobe tumors adjacent to the stomach: fact or fiction?

PubMed

Gates, Vanessa L; Hickey, Ryan; Marshall, Karen; Williams, Melissa; Salzig, Krystina; Lewandowski, Robert J; Salem, Riad

2015-12-01

Radioembolization with (90)Y microspheres is a locoregional radiation therapy for unresectable hepatic neoplasm. Non-target delivery of (90)Y microspheres resulting in gastrointestinal (GI) symptoms is a recognized complication; there is minimal knowledge regarding the radiation effect to the gastric wall from left hepatic lobe (90)Y treatments. Our aim was to study the incidence of GI complications when the target tissue (hepatic parenchyma ± tumor) is in close proximity to the gastric wall. We hypothesized that liver (tumor) to stomach proximity does not correlate with increased toxicity. Between November 2011 and September 2013, we studied all patients who underwent left lobe radioembolization with (90)Y glass microspheres. With Institutional Review Board (IRB) approval, we retrospectively reviewed MRI/CT images of these patients, identifying a subset of patients with the left hepatic lobe <1 cm from the gastric wall. Patients were seen in clinic 1 month posttreatment and subsequently at 3-month intervals. Short- and long-term gastric adverse events were tabulated. Ninety-seven patients successfully underwent left hepatic lobe (90)Y microsphere radioembolization in which the average distance from the liver to the stomach wall was 1.0 ± 2.8 mm. The average dose for patients who received radioembolization to the left hepatic lobe was 109 ± 57 Gy. Fifty patients had tumor within 1 cm of the gastric wall. The average dose for patients who received radioembolization to the left hepatic lobe with tumor within 1 cm of the gastric wall was 121 ± 41 Gy. There were no reportable or recordable medical events. Of the patients, 34% reported abdominal pain that was grade 1-2; 65% of the patients reported no abdominal pain. None of the 97 patients developed a clinically evident GI ulcer. Patients with left lobe tumors adjacent to or abutting the stomach do not exhibit acute or chronic radiation effects following radioembolization with glass microspheres.

Somatostatin-based radiotherapy with [90Y-DOTA]-TOC in neuroendocrine tumors: long-term outcome of a phase I dose escalation study

PubMed Central

2013-01-01

Background We describe the long-term outcome after clinical introduction and dose escalation of somatostatin receptor targeted therapy with [90Y-DOTA]-TOC in patients with metastasized neuroendocrine tumors. Methods In a clinical phase I dose escalation study we treated patients with increasing [90Y-DOTA]-TOC activities. Multivariable Cox regression and competing risk regression were used to compare efficacy and toxicities of the different dosage protocols. Results Overall, 359 patients were recruited; 60 patients were enrolled for low dose (median: 2.4 GBq/cycle, range 0.9-7.8 GBq/cycle), 77 patients were enrolled for intermediate dose (median: 3.3 GBq/cycle, range: 2.0-7.4 GBq/cycle) and 222 patients were enrolled for high dose (median: 6.7 GBq/cycle, range: 3.7-8.1 GBq/cycle) [90Y-DOTA]-TOC treatment. The incidences of hematotoxicities grade 1–4 were 65.0%, 64.9% and 74.8%; the incidences of grade 4/5 kidney toxicities were 8.4%, 6.5% and 14.0%, and the median survival was 39 (range: 1–158) months, 34 (range: 1–118) months and 29 (range: 1–113) months. The high dose protocol was associated with an increased risk of kidney toxicity (Hazard Ratio: 3.12 (1.13-8.59) vs. intermediate dose, p = 0.03) and a shorter overall survival (Hazard Ratio: 2.50 (1.08-5.79) vs. low dose, p = 0.03). Conclusions Increasing [90Y-DOTA]-TOC activities may be associated with increasing hematological toxicities. The dose related hematotoxicity profile of [90Y-DOTA]-TOC could facilitate tailoring [90Y-DOTA]-TOC in patients with preexisting hematotoxicities. The results of the long-term outcome suggest that fractionated [90Y-DOTA]-TOC treatment might allow to reduce renal toxicity and to improve overall survival. Trial registration ClinicalTrials.gov number:NCT00978211 PMID:23320604

Electrochemical planarization

DOEpatents

Bernhardt, A.F.; Contolini, R.J.

1993-10-26

In a process for fabricating planarized thin film metal interconnects for integrated circuit structures, a planarized metal layer is etched back to the underlying dielectric layer by electropolishing, ion milling or other procedure. Electropolishing reduces processing time from hours to minutes and allows batch processing of multiple wafers. The etched back planarized thin film interconnect is flush with the dielectric layer. 12 figures.

A systematic review of contralateral liver lobe hypertrophy after unilobar selective internal radiation therapy with Y90.

PubMed

Teo, Jin-Yao; Allen, John C; Ng, David C; Choo, Su-Pin; Tai, David W M; Chang, Jason P E; Cheah, Foong-Khoon; Chow, Pierce K H; Goh, Brian K P

2016-01-01

Curative liver resection is the treatment of choice for both primary and secondary liver malignancies. However, an inadequate future liver remnant (FLR) frequently precludes successful surgery. Portal vein embolization is the gold-standard modality for inducing hypertrophy of the FLR. In recent times, unilobar Yttrium-90 selective internal radiation therapy (SIRT) has been reported to induce hypertrophy of the contralateral, untreated liver lobe. The aim of this study is to review the current literature reporting on contralateral liver hypertrophy induced by unilobar SIRT. A systematic review of the English-language literature between 2000 and 2014 was performed using the search terms "Yttrium 90" OR "selective internal radiation therapy" OR "radioembolization" AND "hypertrophy". Seven studies, reporting on 312 patients, were included. Two hundred and eighty four patients (91.0%) received treatment to the right lobe. Two hundred and fifteen patients had hepatocellular carcinoma (HCC), 12 had intrahepatic cholangiocarcinoma, and 85 had liver metastases from mixed primaries. Y90 SIRT resulted in contralateral liver hypertrophy which ranged from 26 to 47% at 44 days-9 months. All studies were retrospective in nature, and heterogeneous, with substantial variations relative to pathology treated, underlying liver disease, dosage and delivery of Y90, number of treatment sessions and time to measurement of hypertrophy. Unilobar Y90 SIRT results in significant hypertrophy of the contralateral liver lobe. The rate of hypertrophy seems to be slower than that achieved by other methods. Copyright © 2015 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.

Relation of planar Hall and planar Nernst effects in thin film permalloy

NASA Astrophysics Data System (ADS)

Wesenberg, D.; Hojem, A.; Bennet, R. K.; Zink, B. L.

2018-06-01

We present measurements of the planar Nernst effect (PNE) and the planar Hall effect (PHE) of nickel-iron (Ni–Fe) alloy thin films. We suspend the thin-film samples, measurement leads, and lithographically-defined heaters and thermometers on silicon-nitride membranes to greatly simplify control and measurement of thermal gradients essential to quantitative determination of magnetothermoelectric effects. Since these thermal isolation structures allow measurements of longitudinal thermopower, or the Seebeck coefficient, and four-wire electrical resistivity of the same thin film, we can quantitatively demonstrate the link between the longitudinal and transverse effects as a function of applied in-plane field and angle. Finite element thermal analysis of this essentially 2D structure allows more confident determination of the thermal gradient, which is reduced from the simplest assumptions due to the particular geometry of the membranes, which are more than 350 μm wide in order to maximize sensitivity to transverse thermoelectric effects. The resulting maximum values of the PNE and PHE coefficients for the Ni–Fe film with 80% Ni we study here are and , respectively. All signals are exclusively symmetry with applied field, ruling out long-distance spin transport effects. We also consider a Mott-like relation between the PNE and PHE, and use both this and the standard Mott relation to determine the energy-derivative of the resistivity at the Fermi energy to be , which is very similar to values for films we previously measured using similar thermal platforms. Finally, using an estimated value for the lead contribution to the longitudinal thermopower, we show that the anisotropic magnetoresistance (AMR) ratio in this Ni–Fe film is two times larger than the magnetothermopower ratio, which is the first evidence of a deviation from strict adherence to the Mott relation between Seebeck coefficient and resistivity.

Preparation of silica coated and 90Y-radiolabeled β-NaYF4 upconverting nanophosphors for multimodal tracing

NASA Astrophysics Data System (ADS)

Najmr, Stan; Lu, Tianfeng; Keller, Austin W.; Zhang, Mingyue; Lee, Jennifer D.; Makvandi, Mehran; Pryma, Daniel A.; Kagan, Cherie R.; Murray, Christopher B.

2018-06-01

Rare-earth (RE) compounds have been actively pursued for therapeutic and diagnostic applications due to their ability to upconvert near infrared light into the UV–vis range. Through nanoengineering and bottom-up synthesis, additional functionality can be added to these upconverting systems. Herein, we report the synthesis of 90Y-doped β-NaYF4:Er, Yb upconverting nanophosphors (UCNPs) to enable β-particle emission and upconversion by the same UCNP. To homogenously incorporate the radionuclides, we employ a hydroxide metathesis method to produce the RE precursor required for the solvothermal synthesis of monodisperse UCNPs. Once incorporated, we find that the β-emitting 90Y dopants do not influence the energy pathways required for upconversion, enabling simultaneous radio- and optical-tracing. The resulting large (>100 nm in height and width), anisotropic, 90Y-radiolabeled β-NaYF4 UCNPs are then coated with silica using a modified, micelle-driven Stöber process to enable their dispersion in polar solvents. Doing so highlights the importance of surfactant (Igepal CO-520) and silica source (tetraethyl orthosilicate) interactions to the continuity of the silica shell and makes the vast library of silica surface chemistry and functionality accessible to upconverting radiotracers.

Survival After Accidental Extrahepatic Distribution of Y90 Microspheres to the Mesentery During a Radioembolization Procedure

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

Sabet, Amir; Ahmadzadehfar, Hojjat; Schaefer, Nico

2012-08-15

We present the acute management and outcome of a patient after an accidental mesenteric distribution of Y90 microspheres during radioembolization (RE). This report describes and highlights: (1) the incidence of a significant reflux during a RE session while injecting into a replaced right hepatic artery from the superior mesenteric artery, (2) the appearance of diffuse mesenteric Y90 distribution in bremsstrahlung-imaging, (3) the management protocol with the radiation protection agent amifostine, (4) the development of typical adverse effects in the expected time window, and (5) survival of the patient without long-term sequelae. This report should sensitize physicians to this particular problemmore » and may help to avoid as well as manage similar radioembolization incidences.« less

Dynamometer Testing of Planar Mixed-Potential Sensors

DOE PAGES

Kreller, C. R.; Sekhar, P. K.; Prikhodko, V.; ...

2014-09-22

Mixed-potential sensors for vehicle on-board emissions monitoring applications have been fabricated in an automotive planar sensor configuration using high temperature ceramic co-fire methods. The sensing element consists of dense Pt and LaSrCrO electrodes and a porous 3 mol% YSZ electrolyte. This sensor construct exhibits preferential selectivity to NO x (NO+NO 2) when operated at a positive current bias. The performance of the planar sensors under engine-out conditions was recently evaluated at the Oak Ridge National Laboratory National Transportation Research Center on a GM 1.9L CIDI diesel engine. The sensor response qualitatively tracked transients in NO x measured via FTIR undermore » transient engine operation. Additionally, quantitative correlation between sensor voltage response and total NO x concentration was obtained under steady-state engine speed and load while varying exhaust gas recirculation (EGR) levels.« less

Molecular dynamics simulations of field emission from a planar nanodiode

NASA Astrophysics Data System (ADS)

Torfason, Kristinn; Valfells, Agust; Manolescu, Andrei

2015-03-01

High resolution molecular dynamics simulations with full Coulomb interactions of electrons are used to investigate field emission in planar nanodiodes. The effects of space-charge and emitter radius are examined and compared to previous results concerning transition from Fowler-Nordheim to Child-Langmuir current [Y. Y. Lau, Y. Liu, and R. K. Parker, Phys. Plasmas 1, 2082 (1994) and Y. Feng and J. P. Verboncoeur, Phys. Plasmas 13, 073105 (2006)]. The Fowler-Nordheim law is used to determine the current density injected into the system and the Metropolis-Hastings algorithm to find a favourable point of emission on the emitter surface. A simple fluid like model is also developed and its results are in qualitative agreement with the simulations.

Structures and bonding of C2X2Y q (X=Si,Ge,Sn,Pb; Y=C,Si,Ge,Sn,Pb; q = +1,0,-1): π-type templates for planar tetracoordinate heavier group 14 atoms

NASA Astrophysics Data System (ADS)

Yu, Shuang; Sui, Jing-jing; Xu, Jing; Ding, Yi-hong

2018-05-01

Contrasting the big family of the planar tetracoordinate carbon (ptC), species featuring the planar tetracoordinate heavier group element M (ptM) have been largely limited. Effective structural frameworks to accommodate such ptM centres are thus highly desired. In the present article, we report an extensive computational study on 60 pentatomic systems C2X2Yq (X=Si,Ge,Sn,Pb; Y=C,Si,Ge,Sn,Pb; q = +1,0,-1) covering both the low and high spin states. Up to 34 systems were shown to have the very low-lying singlet planar tetracoordinate heavier group 14 (ptM with M=Si,Ge,Sn,Pb) structures bearing the 19 (q = +1), 20 (q = 0) and 21 (q = -1) valence electrons (ve). Structural and bonding analysis confirmed the effectiveness of the inherent π-type ligand skeleton XCCX or XCCY that each have several sets of π-bonding orbitals to stabilise the ptM centre. The structural and bonding motifs of these ptMs differ greatly from the classic ptMs, which have the σ-type ligand skeleton, smaller number of valence electrons (≤18ve), and the centre → ligand π-delocalisation.

Multi-planar bending properties of lumbar intervertebral joints following cyclic bending.

PubMed

Chow, Daniel H K; Luk, Keith D K; Holmes, Andrew D; Li, Xing-Fei; Tam, Steven C W

2004-02-01

To assess the changes in the multi-planar bending properties of intervertebral joints following cyclic bending along different directions. An in vitro biomechanical study using porcine lumbar motion segments. Repeated bending has been suggested as part of the etiology of gradual prolapse of the intervertebral disc, but the multi-planar changes in bending properties following cyclic loading have not been examined in detail. Porcine lumbar motion segments were subject to 1500 cycles of bending along directions of 0 degrees (flexion), 30 degrees, 60 degrees, or 90 degrees (right lateral bending). The multi-planar bending moments and hysteresis energies were recorded before loading and after various cycle numbers. Repeated bending at 30 degrees and 60 degrees resulted in greater decreases in mean bending moment and hysteresis energy than bending at 0 degrees or 90 degrees. No significant differences were seen between loading groups for the change in bending moment along the anterior testing directions, but significant differences were observed in the posterior and lateral testing directions, with bending at 30 degrees causing a significantly greater decrease in bending moment in the postero-lateral directions. The change in mechanical properties of porcine intervertebral joints due to cyclic bending depend on the direction of loading and the direction in which the properties are measured. Loading at 30 degrees provokes the most marked changes in bending moment and hysteresis energy.

Matched pairs dosimetry: 124I/131I metaiodobenzylguanidine and 124I/131I and 86Y/90Y antibodies.

PubMed

Lopci, Egesta; Chiti, Arturo; Castellani, Maria Rita; Pepe, Giovanna; Antunovic, Lidija; Fanti, Stefano; Bombardieri, Emilio

2011-05-01

The technological advances in imaging and production of radiopharmaceuticals are driving an innovative way of evaluating the targets for antineoplastic therapies. Besides the use of imaging to better delineate the volume of external beam radiation therapy in oncology, modern imaging techniques are able to identify targets for highly specific medical therapies, using chemotherapeutic drugs and antiangiogenesis molecules. Moreover, radionuclide imaging is able to select targets for radionuclide therapy and to give the way to in vivo dose calculation to target tissues and to critical organs. This contribution reports the main studies published on matched pairs dosimetry with (124)I/(131)I- and (86)Y/(90)Y-labelled radiopharmaceuticals, with an emphasis on metaiodobenzylguanidine (MIBG) and monoclonal antibodies.

Optimized conditions for chelation of yttrium-90-DOTA immunoconjugates.

PubMed

Kukis, D L; DeNardo, S J; DeNardo, G L; O'Donnell, R T; Meares, C F

1998-12-01

Radioimmunotherapy (RIT) with 90Y-labeled immunoconjugates has shown promise in clinical trials. The macrocyclic chelating agent 1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid (DOTA) binds 90Y with extraordinary stability, minimizing the toxicity of 90Y-DOTA immunoconjugates arising from loss of 90Y to bone. However, reported 90Y-DOTA immunoconjugate product yields have been typically only < or =50%. Improved yields are needed for RIT with 90Y-DOTA immunoconjugates to be practical. (S) 2-[p-(bromoacetamido)benzyl]-DOTA (BAD) was conjugated to the monoclonal antibody Lym-1 via 2-iminothiolane (2IT). The immunoconjugate product, 2IT-BAD-Lym-1, was labeled in excess yttrium in various buffers over a range of concentrations and pH. Kinetic studies were performed in selected buffers to estimate radiolabeling reaction times under prospective radiopharmacy labeling conditions. The effect of temperature on reaction kinetics was examined. Optimal radiolabeling conditions were identified and used in eight radiolabeling experiments with 2IT-BAD-Lym-1 and a second immunoconjugate, DOTA-peptide-chimeric L6, with 248-492 MBq (6.7-13.3 mCi) of 90Y. Ammonium acetate buffer (0.5 M) was associated with the highest uptake of yttrium. On the basis of kinetic data, the time required to chelate 94% of 90Y (four half-times) under prospective radiopharmacy labeling conditions in 0.5 M ammonium acetate was 17-148 min at pH 6.5, but it was only 1-10 min at pH 7.5. Raising the reaction temperature from 25 degrees C to 37 degrees C markedly increased the chelation rate. Optimal radiolabeling conditions were identified as: 30-min reaction time, 0.5 M ammonium acetate buffer, pH 7-7.5 and 37 degrees C. In eight labeling experiments under optimal conditions, a mean product yield (+/- s.d.) of 91%+/-8% was achieved, comparable to iodination yields. The specific activity of final products was 74-130 MBq (2.0-3.5 mCi) of 90Y per mg of monoclonal antibody. The immunoreactivity of 90Y

Improved scatter correction with factor analysis for planar and SPECT imaging

NASA Astrophysics Data System (ADS)

Knoll, Peter; Rahmim, Arman; Gültekin, Selma; Šámal, Martin; Ljungberg, Michael; Mirzaei, Siroos; Segars, Paul; Szczupak, Boguslaw

2017-09-01

Quantitative nuclear medicine imaging is an increasingly important frontier. In order to achieve quantitative imaging, various interactions of photons with matter have to be modeled and compensated. Although correction for photon attenuation has been addressed by including x-ray CT scans (accurate), correction for Compton scatter remains an open issue. The inclusion of scattered photons within the energy window used for planar or SPECT data acquisition decreases the contrast of the image. While a number of methods for scatter correction have been proposed in the past, in this work, we propose and assess a novel, user-independent framework applying factor analysis (FA). Extensive Monte Carlo simulations for planar and tomographic imaging were performed using the SIMIND software. Furthermore, planar acquisition of two Petri dishes filled with 99mTc solutions and a Jaszczak phantom study (Data Spectrum Corporation, Durham, NC, USA) using a dual head gamma camera were performed. In order to use FA for scatter correction, we subdivided the applied energy window into a number of sub-windows, serving as input data. FA results in two factor images (photo-peak, scatter) and two corresponding factor curves (energy spectra). Planar and tomographic Jaszczak phantom gamma camera measurements were recorded. The tomographic data (simulations and measurements) were processed for each angular position resulting in a photo-peak and a scatter data set. The reconstructed transaxial slices of the Jaszczak phantom were quantified using an ImageJ plugin. The data obtained by FA showed good agreement with the energy spectra, photo-peak, and scatter images obtained in all Monte Carlo simulated data sets. For comparison, the standard dual-energy window (DEW) approach was additionally applied for scatter correction. FA in comparison with the DEW method results in significant improvements in image accuracy for both planar and tomographic data sets. FA can be used as a user

Quantitative proteomics reveals molecular mechanism of gamabufotalin and its potential inhibition on Hsp90 in lung cancer.

PubMed

Zhang, Liyuan; Yu, Zhenlong; Wang, Yan; Wang, Xiaobo; Zhang, Lianru; Wang, Chao; Yue, Qingxi; Wang, Xun; Deng, Sa; Huo, Xiaokui; Tian, Xiangge; Huang, Shanshan; Zhang, Baojing; Ma, Xiaochi

2016-11-22

Gamabufotalin (CS-6) is a major bufadienolide of Chansu, which shows desirable metabolic stability and less adverse effect in cancer therapy. CS-6 treatment inhibited the proliferation of NSCLC in a nanomolar range. And CS-6 could induce G2/M cell cycle arrest and apoptosis in A549 cells. However, its molecular mechanism in antitumor activity remains poorly understood. We employed a quantitative proteomics approach to identify the potential cellular targets of CS-6, and found 38 possible target-related proteins. Among them, 31 proteins were closely related in the protein-protein interaction network. One of the regulatory nodes in key pathways was occupied by Hsp90. Molecular docking revealed that CS-6 interacted with the ATP-binding sites of Hsp90. In addition, CS-6 inhibited the chaperone function of Hsp90 and reduced expression of Hsp90-dependent client proteins. Moreover, CS-6 markedly down-regulated the protein level of Hsp90 in tumor tissues of the xenograft mice. Taken together, our results suggest that CS-6 might be a novel inhibitor of Hsp90, and the possible network associated with CS-6 target-related proteins was constructed, which provided experimental evidence for the preclinical value of using CS-6 as an effective antitumor agent in treatment of NSCLC.

Molecular dynamics simulations of field emission from a planar nanodiode

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

Torfason, Kristinn; Valfells, Agust; Manolescu, Andrei

High resolution molecular dynamics simulations with full Coulomb interactions of electrons are used to investigate field emission in planar nanodiodes. The effects of space-charge and emitter radius are examined and compared to previous results concerning transition from Fowler-Nordheim to Child-Langmuir current [Y. Y. Lau, Y. Liu, and R. K. Parker, Phys. Plasmas 1, 2082 (1994) and Y. Feng and J. P. Verboncoeur, Phys. Plasmas 13, 073105 (2006)]. The Fowler-Nordheim law is used to determine the current density injected into the system and the Metropolis-Hastings algorithm to find a favourable point of emission on the emitter surface. A simple fluid likemore » model is also developed and its results are in qualitative agreement with the simulations.« less

Note: A contraction channel design for planar shock wave enhancement

NASA Astrophysics Data System (ADS)

Zhan, Dongwen; Li, Zhufei; Yang, Jianting; Zhu, Yujian; Yang, Jiming

2018-05-01

A two-dimensional contraction channel with a theoretically designed concave-oblique-convex wall profile is proposed to obtain a smooth planar-to-planar shock transition with shock intensity amplification that can easily overcome the limitations of a conventional shock tube. The concave segment of the wall profile, which is carefully determined based on shock dynamics theory, transforms the shock shape from an initial plane into a cylindrical arc. Then the level of shock enhancement is mainly contributed by the cylindrical shock convergence within the following oblique segment, after which the cylindrical shock is again "bent" back into a planar shape through the third section of the shock dynamically designed convex segment. A typical example is presented with a combination of experimental and numerical methods, where the shape of transmitted shock is almost planar and the post-shock flow has no obvious reflected waves. A quantitative investigation shows that the difference between the designed and experimental transmitted shock intensities is merely 1.4%. Thanks to its advantage that the wall profile design is insensitive to initial shock strength variations and high-temperature gas effects, this method exhibits attractive potential as an efficient approach to a certain, controllable, extreme condition of a strong shock wave with relatively uniform flow behind.

Prior-knowledge Fitting of Accelerated Five-dimensional Echo Planar J-resolved Spectroscopic Imaging: Effect of Nonlinear Reconstruction on Quantitation.

PubMed

Iqbal, Zohaib; Wilson, Neil E; Thomas, M Albert

2017-07-24

1 H Magnetic Resonance Spectroscopic imaging (SI) is a powerful tool capable of investigating metabolism in vivo from mul- tiple regions. However, SI techniques are time consuming, and are therefore difficult to implement clinically. By applying non-uniform sampling (NUS) and compressed sensing (CS) reconstruction, it is possible to accelerate these scans while re- taining key spectral information. One recently developed method that utilizes this type of acceleration is the five-dimensional echo planar J-resolved spectroscopic imaging (5D EP-JRESI) sequence, which is capable of obtaining two-dimensional (2D) spectra from three spatial dimensions. The prior-knowledge fitting (ProFit) algorithm is typically used to quantify 2D spectra in vivo, however the effects of NUS and CS reconstruction on the quantitation results are unknown. This study utilized a simulated brain phantom to investigate the errors introduced through the acceleration methods. Errors (normalized root mean square error >15%) were found between metabolite concentrations after twelve-fold acceleration for several low concentra- tion (<2 mM) metabolites. The Cramér Rao lower bound% (CRLB%) values, which are typically used for quality control, were not reflective of the increased quantitation error arising from acceleration. Finally, occipital white (OWM) and gray (OGM) human brain matter were quantified in vivo using the 5D EP-JRESI sequence with eight-fold acceleration.

Cancer radiotheranostics targeting carbonic anhydrase-IX with 111In- and 90Y-labeled ureidosulfonamide scaffold for SPECT imaging and radionuclide-based therapy

PubMed Central

Iikuni, Shimpei; Ono, Masahiro; Watanabe, Hiroyuki; Shimizu, Yoichi; Sano, Kohei; Saji, Hideo

2018-01-01

Hypoxic cells dynamically translocate during tumor growth and after radiotherapy. The most desirable direction for therapy targeting hypoxic cells is combining imaging and therapy (theranostics), which may help realize personalized medicine. Here, we conducted cancer radiotheranostics targeting carbonic anhydrase-IX (CA-IX), which is overexpressed in many kinds of hypoxic cancer cells, using low-molecular-weight 111In and 90Y complexes with a bivalent ureidosulfonamide scaffold as the CA-IX-binding moiety ([111In/90Y]US2). Methods: The targeting ability of [111In]US2 was evaluated by in vivo biodistribution study in CA-IX high-expressing (HT-29) tumor-bearing mice. In vivo imaging of HT-29 tumors was carried out using single photon emission computed tomography (SPECT). [90Y]US2 was administered to HT-29 tumor-bearing mice to evaluate cancer therapeutic effects. Results: [111In]US2 highly and selectively accumulated within HT-29 tumors (4.57% injected dose/g tumor at 1 h postinjection), was rapidly cleared from the blood pool and muscle after 4 h based on a biodistribution study, and visualized HT-29 tumor xenografts in mice at 4 h postinjection with SPECT. Radionuclide-based therapy with [90Y]US2 significantly delayed HT-29 tumor growth compared with that of untreated mice (P = 0.02 on day 28, Student's t-test), without any critical hematological toxicity due to its rapid pharmacokinetics. Conclusion: These results indicate that cancer radiotheranostics with [111In/90Y]US2 provides a novel strategy of theranostics for cancer hypoxia.

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.

Evaluation of Efficacy of Radioimmunotherapy with 90Y-Labeled Fully Human Anti-Transferrin Receptor Monoclonal Antibody in Pancreatic Cancer Mouse Models

PubMed Central

Sugyo, Aya; Tsuji, Atsushi B.; Sudo, Hitomi; Okada, Maki; Koizumi, Mitsuru; Satoh, Hirokazu; Kurosawa, Gene; Kurosawa, Yoshikazu; Saga, Tsuneo

2015-01-01

Objective Pancreatic cancer is an aggressive tumor and the prognosis remains poor. Therefore, development of more effective therapy is needed. We previously reported that 89Zr-labeled TSP-A01, an antibody against transferrin receptor (TfR), is highly accumulated in a pancreatic cancer xenograft, but not in major normal organs. In the present study, we evaluated the efficacy of radioimmunotherapy (RIT) with 90Y-TSP-A01 in pancreatic cancer mouse models. Methods TfR expression in pancreatic cancer cell lines (AsPC-1, BxPC-3, MIAPaCa-2) was evaluated by immunofluorescence staining. 111In-labeled anti-TfR antibodies (TSP-A01, TSP-A02) were evaluated in vitro by cell binding assay with the three cell lines and by competitive inhibition assay with MIAPaCa-2. In vivo biodistribution was evaluated in mice bearing BxPC-3 and MIAPaCa-2 xenografts. Tumor volumes of BxPC-3 and MIAPaCa-2 were sequentially measured after 90Y-TSP-A01 injection and histological analysis of tumors was conducted. Results MIAPaCa-2 cells showed the highest TfR expression, followed by AsPC-1 and BxPC-3 cells. 111In-TSP-A01 and 111In-TSP-A02 bound specifically to the three cell lines according to TfR expression. The dissociation constants for TSP-A01, DOTA-TSP-A01, TSP-A02, and DOTA-TSP-A02 were 0.22, 0.28, 0.17, and 0.22 nM, respectively. 111In-TSP-A01 was highly accumulated in tumors, especially in MIAPaCa-2, but this was not true of 111In-TSP-A02. The absorbed dose for 90Y-TSP-A01 was estimated to be 8.3 Gy/MBq to BxPC-3 and 12.4 Gy/MBq to MIAPaCa-2. MIAPaCa-2 tumors treated with 3.7 MBq of 90Y-TSP-A01 had almost completely disappeared around 3 weeks after injection and regrowth was not observed. Growth of BxPC-3 tumors was inhibited by 3.7 MBq of 90Y-TSP-A01, but the tumor size was not reduced. Conclusion 90Y-TSP-A01 treatment achieved an almost complete response in MIAPaCa-2 tumors, whereas it merely inhibited the growth of BxPC-3 tumors. 90Y-TSP-A01 is a promising RIT agent for pancreatic cancer

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.

The Effect of Symmetry on the Hydrodynamic Stability of and Bifurcation from Planar Shear Flows

DTIC Science & Technology

1990-12-01

Effect of Symmetry on the Hydrodynamic Stability of ant Bifurcation from Planar Shear Flows AFOSR-88-0196 6. AUTHOR(S) 61102F 2304/A4 Thomas J. Bridges 7...December 1990 The Effect of Symmetry on the Hydrodynamic Stability of and Bifurcation from Planar Shear Flows TIIhOMAS J. BIUDGES MATl EM ATIc(AL...spatial stabili’.y into the nonlinear regime and a theory for spa- tial Hopf bifurcation , spatial Floquet theory, wavelength doubling and spatially quasi

PET/CT-Based Dosimetry in 90Y-Microsphere Selective Internal Radiation Therapy: Single Cohort Comparison With Pretreatment Planning on 99mTc-MAA Imaging and Correlation With Treatment Efficacy

PubMed Central

Song, Yoo Sung; Paeng, Jin Chul; Kim, Hyo-Cheol; Chung, Jin Wook; Cheon, Gi Jeong; Chung, June-Key; Lee, Dong Soo; Kang, Keon Wook

2015-01-01

Abstract 90Y PET/CT can be acquired after 90Y-microsphere selective radiation internal therapy (SIRT) to describe radioactivity distribution. We performed dosimetry using 90Y-microsphere PET/CT data to evaluate treatment efficacy and appropriateness of activity planning from 99mTc-MAA scan and SPECT/CT. Twenty-three patients with liver malignancy were included in the study. 99mTc-MAA was injected during planning angiography and whole body 99mTc-MAA scan and liver SPECT/CT were acquired. After SIRT using 90Y-resin microsphere, 90Y-microsphere PET/CT was acquired. A partition model (PM) using 4 compartments (tumor, intarget normal liver, out-target normal liver, and lung) was adopted, and absorbed dose to each compartment was calculated based on measurements from 99mTc-MAA SPECT/CT and 90Y-microsphere PET/CT, respectively, to be compared with each other. Progression-free survival (PFS) was evaluated in terms of tumor absorbed doses calculated by 99mTc-MAA SPECT/CT and 90Y-microsphere PET/CT results. Lung shunt fraction was overestimated on 99mTc-MAA scan compared with 90Y-microsphere PET/CT (0.060 ± 0.037 vs. 0.018 ± 0.026, P < 0.01). Tumor absorbed dose exhibited a close correlation between the results from 99mTc-MAA SPECT/CT and 90Y-microsphere PET/CT (r = 0.64, P < 0.01), although the result from 99mTc-MAA SPECT/CT was significantly lower than that from 90Y-microsphere PET/CT (135.4 ± 64.2 Gy vs. 185.0 ± 87.8 Gy, P < 0.01). Absorbed dose to in-target normal liver was overestimated on 99mTc-MAA SPECT/CT compared with PET/CT (62.6 ± 38.2 Gy vs. 45.2 ± 32.0 Gy, P = 0.02). Absorbed dose to out-target normal liver did not differ between 99mTc-MAA SPECT/CT and 90Y-microsphere PET/CT (P = 0.49). Patients with tumor absorbed dose >200 Gy on 90Y-microsphere PET/CT had longer PFS than those with tumor absorbed dose ≤200 Gy (286 ± 56 days vs. 92 ± 20 days, P = 0.046). Tumor absorbed dose calculated by 99m

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.

Silicon Dioxide Planarization: Impacts on Optical Coatings for High Energy Laser

NASA Astrophysics Data System (ADS)

Day, Travis E.

design were also damage tested. A 6-7 J/cm2 LIDT, with 220ps, was observed for HR coatings with SiO2 planarization layers within high electric-field areas within the coating. However, SiO2 planarization at the substrate-coating interface, where the electric-field is minimal, and control (non-planarized) was shown to have a LIDT of 63 +/- 1.2 J/cm 2 and 21.5 +/- 0.5 J/cm2 for 220ps, respectively. At 9ps, the LIDT varied less than 90% difference between the various planarization designs. The substrate-coating planarization multilayer and control coating had an equal LIDT of 9.6 +/- .3 J/cm2 at 9ps.

Assessing the Expected Impact of Global Health Treaties: Evidence From 90 Quantitative Evaluations

PubMed Central

Røttingen, John-Arne

2015-01-01

We assessed what impact can be expected from global health treaties on the basis of 90 quantitative evaluations of existing treaties on trade, finance, human rights, conflict, and the environment. It appears treaties consistently succeed in shaping economic matters and consistently fail in achieving social progress. There are at least 3 differences between these domains that point to design characteristics that new global health treaties can incorporate to achieve positive impact: (1) incentives for those with power to act on them; (2) institutions designed to bring edicts into effect; and (3) interests advocating their negotiation, adoption, ratification, and domestic implementation. Experimental and quasiexperimental evaluations of treaties would provide more information about what can be expected from this type of global intervention. PMID:25393196

Ultrathin two-dimensional MnO2/graphene hybrid nanostructures for high-performance, flexible planar supercapacitors.

PubMed

Peng, Lele; Peng, Xu; Liu, Borui; Wu, Changzheng; Xie, Yi; Yu, Guihua

2013-05-08

Planar supercapacitors have recently attracted much attention owing to their unique and advantageous design for 2D nanomaterials based energy storage devices. However, improving the electrochemical performance of planar supercapacitors still remains a great challenge. Here we report for the first time a novel, high-performance in-plane supercapacitor based on hybrid nanostructures of quasi-2D ultrathin MnO2/graphene nanosheets. Specifically, the planar structures based on the δ-MnO2 nanosheets integrated on graphene sheets not only introduce more electrochemically active surfaces for absorption/desorption of electrolyte ions, but also bring additional interfaces at the hybridized interlayer areas to facilitate charge transport during charging/discharging processes. The unique structural design for planar supercapacitors enables great performance enhancements compared to graphene-only devices, exhibiting high specific capacitances of 267 F/g at current density of 0.2 A/g and 208 F/g at 10 A/g and excellent rate capability and cycling stability with capacitance retention of 92% after 7000 charge/discharge cycles. Moreover, the high planar malleability of planar supercapacitors makes possible superior flexibility and robust cyclability, yielding capacitance retention over 90% after 1000 times of folding/unfolding. Ultrathin 2D nanomaterials represent a promising material platform to realize highly flexible planar energy storage devices as the power back-ups for stretchable/flexible electronic devices.

BCR-ABL1 molecular remission after 90Y-epratuzumab tetraxetan radioimmunotherapy in CD22+ Ph+ B-ALL: proof of principle.

PubMed

Chevallier, Patrice; Bodet-Milin, Caroline; Robillard, Nelly; Eugene, Thomas; Menard, Audrey; Le Houerou, Claire; Guillaume, Thierry; Delaunay, Jacques; Escoffre-Barbe, Martine; Wegener, William A; Goldenberg, David M; Kraeber-Bodéré, Francoise

2013-12-01

Although targeted therapies are used increasingly in hematologic malignancies, we are unaware of any prior studies of radioimmunotherapy (RAIT) in B-acute lymphoblastic leukemia (ALL), even though this radiosensitive tumor expresses CD22, potentially a good target for this approach. Here, we report a patient with Philadelphia chromosome-positive B-ALL in third relapse who received RAIT with (90) yttrium ((90) Y)-labeled anti-CD22 epratuzumab tetraxetan. Seven weeks after initiating therapy, the patient achieved a BCR-ABL1 molecular remission documented by RT-qPCR, which is now continuing at 6 months while awaiting an allogeneic hematopoietic stem cell transplant. (90) Y-Epratuzumab tetraxetan may be a promising therapeutic option for CD22(+) B-ALL patients. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Learning planar Ising models

DOE PAGES

Johnson, Jason K.; Oyen, Diane Adele; Chertkov, Michael; ...

2016-12-01

Inference and learning of graphical models are both well-studied problems in statistics and machine learning that have found many applications in science and engineering. However, exact inference is intractable in general graphical models, which suggests the problem of seeking the best approximation to a collection of random variables within some tractable family of graphical models. In this paper, we focus on the class of planar Ising models, for which exact inference is tractable using techniques of statistical physics. Based on these techniques and recent methods for planarity testing and planar embedding, we propose a greedy algorithm for learning the bestmore » planar Ising model to approximate an arbitrary collection of binary random variables (possibly from sample data). Given the set of all pairwise correlations among variables, we select a planar graph and optimal planar Ising model defined on this graph to best approximate that set of correlations. Finally, we demonstrate our method in simulations and for two applications: modeling senate voting records and identifying geo-chemical depth trends from Mars rover data.« less

Learning planar Ising models

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

Johnson, Jason K.; Oyen, Diane Adele; Chertkov, Michael

Inference and learning of graphical models are both well-studied problems in statistics and machine learning that have found many applications in science and engineering. However, exact inference is intractable in general graphical models, which suggests the problem of seeking the best approximation to a collection of random variables within some tractable family of graphical models. In this paper, we focus on the class of planar Ising models, for which exact inference is tractable using techniques of statistical physics. Based on these techniques and recent methods for planarity testing and planar embedding, we propose a greedy algorithm for learning the bestmore » planar Ising model to approximate an arbitrary collection of binary random variables (possibly from sample data). Given the set of all pairwise correlations among variables, we select a planar graph and optimal planar Ising model defined on this graph to best approximate that set of correlations. Finally, we demonstrate our method in simulations and for two applications: modeling senate voting records and identifying geo-chemical depth trends from Mars rover data.« less

Y90 Radioembolization in chemo-refractory metastastic, liver dominant colorectal cancer patients: outcome assessment applying a predictive scoring system.

PubMed

Damm, Robert; Seidensticker, Ricarda; Ulrich, Gerhard; Breier, Leonie; Steffen, Ingo G; Seidensticker, Max; Garlipp, Benjamin; Mohnike, Konrad; Pech, Maciej; Amthauer, Holger; Ricke, Jens

2016-07-20

In treatment-refractory liver dominant metastatic colorectal cancer, the role of liver directed therapies still is unclear. We sought to determine a prognostic score for Y90 radioembolization in these patients. We analyzed 106 patients with refractory liver dominant mCRC who had undergone a total of 178 Y90 radioembolizations with resin microspheres was collected. Potential factors influencing survival were analyzed using a Cox regression. The Log rank test served to establish prognostic factors and to form a clinical score for outcome prediction after Y90 radioembolization. Median survival of all patients was 6.7 months. Neither age nor prior surgical or systemic therapy nor metastatic spread had an effect on survival. In contrast, hepatic tumor load, Karnofsky index as well as CEA and CA19-9 serums level had a significant influence (p < 0.001, p = 0.037, p = 0.023 and p < 0.001, respectively). These three factors formed a score with 1 point each for tumor load >20 %, CEA >130 ng/ml or CA19-9 > 200U/ml and Karnofsky index <80 %. Patients with a score of 0 and 1 displayed a median OS of 10.4 months. Patients with a score of 2 and 3 demonstrated a median OS of 5.1 months only (p < 0.001). Overaggressive patient selection for Y90 radioembolization of liver dominant chemorefractory mCRC is of questionable benefit. A scoring system comprising hepatic tumor load, CEA and CA19-9 serum levels and Karnofsky index (TuCK-score) may support an improved patient selection. In our cohort of liver only versus liver dominant disease, extrahepatic lung or lymphatic metastases did not significantly alter the prognosis.

Quiet echo planar imaging for functional and diffusion MRI

PubMed Central

Price, Anthony N.; Cordero‐Grande, Lucilio; Malik, Shaihan; Ferrazzi, Giulio; Gaspar, Andreia; Hughes, Emer J.; Christiaens, Daan; McCabe, Laura; Schneider, Torben; Rutherford, Mary A.; Hajnal, Joseph V.

2017-01-01

Purpose To develop a purpose‐built quiet echo planar imaging capability for fetal functional and diffusion scans, for which acoustic considerations often compromise efficiency and resolution as well as angular/temporal coverage. Methods The gradient waveforms in multiband‐accelerated single‐shot echo planar imaging sequences have been redesigned to minimize spectral content. This includes a sinusoidal read‐out with a single fundamental frequency, a constant phase encoding gradient, overlapping smoothed CAIPIRINHA blips, and a novel strategy to merge the crushers in diffusion MRI. These changes are then tuned in conjunction with the gradient system frequency response function. Results Maintained image quality, SNR, and quantitative diffusion values while reducing acoustic noise up to 12 dB (A) is illustrated in two adult experiments. Fetal experiments in 10 subjects covering a range of parameters depict the adaptability and increased efficiency of quiet echo planar imaging. Conclusion Purpose‐built for highly efficient multiband fetal echo planar imaging studies, the presented framework reduces acoustic noise for all echo planar imaging‐based sequences. Full optimization by tuning to the gradient frequency response functions allows for a maximally time‐efficient scan within safe limits. This allows ambitious in‐utero studies such as functional brain imaging with high spatial/temporal resolution and diffusion scans with high angular/spatial resolution to be run in a highly efficient manner at acceptable sound levels. Magn Reson Med 79:1447–1459, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:28653363

Quantitative imaging of rhizosphere pH and CO2 dynamics with planar optodes.

PubMed

Blossfeld, Stephan; Schreiber, Christina Maria; Liebsch, Gregor; Kuhn, Arnd Jürgen; Hinsinger, Philippe

2013-07-01

Live imaging methods have become extremely important for the exploration of biological processes. In particular, non-invasive measurement techniques are key to unravelling organism-environment interactions in close-to-natural set-ups, e.g. in the highly heterogeneous and difficult-to-probe environment of plant roots: the rhizosphere. pH and CO2 concentration are the main drivers of rhizosphere processes. Being able to monitor these parameters at high spatio-temporal resolution is of utmost importance for relevant interpretation of the underlying processes, especially in the complex environment of non-sterile plant-soil systems. This study introduces the application of easy-to-use planar optode systems in different set-ups to quantify plant root-soil interactions. pH- and recently developed CO2-sensors were applied to rhizobox systems to investigate roots with different functional traits, highlighting the potential of these tools. Continuous and highly resolved real-time measurements were made of the pH dynamics around Triticum turgidum durum (durum wheat) roots, Cicer arietinum (chickpea) roots and nodules, and CO2 dynamics in the rhizosphere of Viminaria juncea. Wheat root tips acidified slightly, while their root hair zone alkalized their rhizosphere by more than 1 pH unit and the effect of irrigation on soil pH could be visualized as well. Chickpea roots and nodules acidified the surrounding soil during N2 fixation and showed diurnal changes in acidification activity. A growing root of V. juncea exhibited a large zone of influence (mm) on soil CO2 content and therefore on its biogeochemical surrounding, all contributing to the extreme complexity of the root-soil interactions. This technique provides a unique tool for future root research applications and overcomes limitations of previous systems by creating quantitative maps without, for example, interpolation and time delays between single data points.

Use of Chelex-100 for selectively removing Y-90 from its parent Sr-90

DOEpatents

Huntley, Mark W.

1996-01-01

A method for selectively removing yttrium-90 from its parent strontium-90 contained in an environmental sample includes loading the sample onto a column containing a chelating ion-exchange resin capable of retaining yttrium-90; washing the column with a solution capable of removing strontium, calcium, and other contaminants from the yttrium-90 fraction retained on the column; removing excess acetate salts from the column; eluting yttrium-90 solution from the column and adjusting the pH of this solution to about 2.7; filtering the yttrium-90 solution and weighing this solution for gravimetric yield; and, counting the yttrium-90 containing solution with a radiological counter for a time sufficient to achieve the statistical accuracy desired. It is preferred that the chelating ion-exchange resin is a bidente ligand having the chemical name iminodiacetic acid mounted on a divinyl benzene substrate, converted from sodium form to ammonia form.

Use of Chelex-100 for selectively removing Y-90 from its parent Sr-90

DOEpatents

Huntley, M.W.

1996-02-27

A method for selectively removing yttrium-90 from its parent strontium-90 contained in an environmental sample includes loading the sample onto a column containing a chelating ion-exchange resin capable of retaining yttrium-90; washing the column with a solution capable of removing strontium, calcium, and other contaminants from the yttrium-90 fraction retained on the column; removing excess acetate salts from the column; eluting yttrium-90 solution from the column and adjusting the pH of this solution to about 2.7; filtering the yttrium-90 solution and weighing this solution for gravimetric yield; and, counting the yttrium-90 containing solution with a radiological counter for a time sufficient to achieve the statistical accuracy desired. It is preferred that the chelating ion-exchange resin is a ligand having the chemical name iminodiacetic acid mounted on a divinyl benzene substrate, converted from sodium form to ammonia form.

99mTc-MAA/ 90Y-Bremsstrahlung SPECT/CT after simultaneous Tc-MAA/90Y-microsphere injection for immediate treatment monitoring and further therapy planning for radioembolization.

PubMed

Ahmadzadehfar, Hojjat; Sabet, Amir; Muckle, Marianne; Wilhelm, Kai; Reichmann, Karl; Biersack, Hans-Jürgen; Ezziddin, Samer

2011-07-01

An angiographic evaluation combined with (99m)Tc-macroaggregated albumin (Tc-MAA) scanning should precede the treatment of any selected candidates for radioembolization (RE) of the liver. If the tumours in one liver lobe have not been targeted in the test angiogram, it should be repeated. However, in a few cases treatment of one liver lobe or at least some segments is safe and feasible and performing a repeated test angiogram with Tc-MAA (Re-MAA) in a separate session leads to more radiation exposure and could be time consuming. Our aim was to evaluate the feasibility of concurrent RE of a part of the liver and therapy planning for another region by simultaneous injection of the Tc-MAA and (90)Y-microspheres in two different locations in the therapy session. Tc-MAA and bremsstrahlung (BS) single photon emission computed tomography (SPECT)/CT were performed separately in an effort to distinguish between the distributions of these two different radiopharmaceuticals. RE was combined with a simultaneous second test angiogram of another lobe or segments in the same session in six patients [44-70 years; five women (83%)]. Five patients suffered from colorectal carcinoma (CRC) and one from ovarian cancer. Tc-MAA and BS SPECT/CT were performed for all cases. Post-therapeutic Tc-MAA SPECT/CT showed in all patients only the distribution of Tc-MAA without any detectable BS. Evaluation of (90)Y-microsphere distribution was not always possible in the post-therapeutic BS scan performed 24 h later due to remaining Tc-MAA radiation. However, scans performed at 48 h post-intervention no longer showed any Tc-MAA "contamination". Combining RE and Re-MAA is feasible in appropriately selected patients.

Planar micromixer

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

Fiechtner, Gregory J; Singh, Anup K; Wiedenman, Boyd J

2008-03-18

The present embodiment describes a laminar-mixing embodiment that utilizes simple, three-dimensional injection. Also described is the use of the embodiment in combination with wide and shallow sections of channel to affect rapid mixing in microanalytical systems. The shallow channel sections are constructed using all planar micromachining techniques, including those based on isotropic etching. The planar construction enables design using minimum dispersion concepts that, in turn, enable simultaneous mixing and injection into subsequent chromatography channels.

Yttrium-90 -- current status, expected availability and applications of a high beta energy emitter.

PubMed

Montaña, R Leyva; González, I Hernández; Ramirez, A Alberti; Garaboldi, L; Chinol, M

2012-07-01

Yttrium-90 ((90)Y, T(1/2) 64.14 h) is a key example of a high beta energy-emitting radionuclide which is available from the strontium-90 ((90)Sr)/(90)Y radionuclide generator system. Clinical uses of (90)Y-labeled radiopharmaceutical agents have been pursued for many years and many applications have proven to be clinical effective. These most notably include the application of 90Y-labeled antibodies for a variety of applications such as for effective treatment of non-Hodgkin's lymphoma. One of the major advantages for use of (90)Y is ready availability from the very long-lived (90)Sr parent (T(1/2) 28.78 y). Because of the importance of maintaining generator performance and minimizing parent breakthrough, this paper describes development, use and quality control of both high capacity cation adsorption-type and electrochemical generator systems. In addition, the preparation and targeting to tumors in mice of DOTA-conjugated Nimotuzamab (h-R3) antibody which recognizes the external domain of the EPFR antibody radiolabeled with (90)Y obtained from the electrochemical generator is also described. As a key example for clinical applications of (90)Y, the use of (90)Y-labeled biotin for intra-operative pre-targeting for radionuclide therapy (IART®) of breast cancer is also described.

Influence of time delay on the estimated lung shunt fraction on 99mTc-labeled MAA scintigraphy for 90Y microsphere treatment planning.

PubMed

De Gersem, Ruth; Maleux, Geert; Vanbilloen, Hubert; Baete, Kristof; Verslype, Chris; Haustermans, Karin; Verbruggen, Alfons; Van Cutsem, Eric; Deroose, Christophe Michel

2013-12-01

90Y-microspheres therapy is used to treat selected patients with primary or metastatic liver tumors in a safe and effective way. As a preparation for 90Y-microspheres treatment, a 99mTc-macroaggregated albumin (99mTc-MAA) simulation procedure is essential to evaluate particle shunting to the lung or gastrointestinal tract. We investigated the effect of interval between injection of 99mTc-MAA and time of scanning on the lung shunt fraction (LSF). In 4 patients with secondary hepatic malignancies who underwent repeated whole-body scintigraphy up to 5 hours after injection of 99mTc-MAA, a marked change in LSF was observed. It appears that tracer degradation leads to an important overestimation of LSF at later time points. An overestimation of LSF can lead to dose reduction or canceling of the planned 90Y-microspheres treatment. It is concluded that the interval between injection and scanning should be kept as short as possible.

Progress in integrated-circuit horn antennas for receiver applications. Part 2: A 90 GHz quasi-integrated horn antenna receiver

NASA Technical Reports Server (NTRS)

Ali-Ahmad, Walid Y.; Eleftheriades, George V.; Rebeiz, Gabriel M.

1992-01-01

A receiver belonging to the family of integrated planar receivers has been developed at 90 GHz. It consists of a planar Schottky-diode placed at the feed of a dipole-probe suspended inside an integrated horn antenna. The measured planar mixer single-sideband conversion loss at 91.2 GHz (LO) with a 200 MHz IF frequency is 8.3dB plus or minus 0.3dB. The low cost of fabrication and simplicity of this design makes it ideal for millimeter and submillimeter-wave receivers.

Measurement of six-degree-of-freedom planar motions by using a multiprobe surface encoder

NASA Astrophysics Data System (ADS)

Li, Xinghui; Shimizu, Yuki; Ito, Takeshi; Cai, Yindi; Ito, So; Gao, Wei

2014-12-01

A multiprobe surface encoder for optical metrology of six-degree-of-freedom (six-DOF) planar motions is presented. The surface encoder is composed of an XY planar scale grating with identical microstructures in X- and Y-axes and an optical sensor head. In the optical sensor head, three paralleled laser beams were used as laser probes. After being divided by a beam splitter, the three laser probes were projected onto the scale grating and a reference grating with identical microstructures, respectively. For each probe, the first-order positive and negative diffraction beams along the X- and Y-directions from the scale grating and from the reference grating superimposed with each other and four pieces of interference signals were generated. Three-DOF translational motions of the scale grating Δx, Δy, and Δz can be obtained simultaneously from the interference signals of each probe. Three-DOF angular error motions θX, θY, and θZ can also be calculated simultaneously from differences of displacement output variations and the geometric relationship among the three probes. A prototype optical sensor head was designed, constructed, and evaluated. Experimental results verified that this surface encoder could provide measurement resolutions of subnanometer and better than 0.1 arc sec for three-DOF translational motions and three-DOF angular error motions, respectively.

Non-planar chemical preconcentrator

DOEpatents

Manginell, Ronald P [Albuquerque, NM; Adkins, Douglas R [Albuquerque, NM; Sokolowski, Sara S [Albuquerque, NM; Lewis, Patrick R [Albuquerque, NM

2006-10-10

A non-planar chemical preconcentrator comprises a high-surface area, low mass, three-dimensional, flow-through sorption support structure that can be coated or packed with a sorptive material. The sorptive material can collect and concentrate a chemical analyte from a fluid stream and rapidly release it as a very narrow temporal plug for improved separations in a microanalytical system. The non-planar chemical preconcentrator retains most of the thermal and fabrication benefits of a planar preconcentrator, but has improved ruggedness and uptake, while reducing sorptive coating concerns and extending the range of collectible analytes.

Enjoyment of Euclidean Planar Triangles

ERIC Educational Resources Information Center

Srinivasan, V. K.

2013-01-01

This article adopts the following classification for a Euclidean planar [triangle]ABC, purely based on angles alone. A Euclidean planar triangle is said to be acute angled if all the three angles of the Euclidean planar [triangle]ABC are acute angles. It is said to be right angled at a specific vertex, say B, if the angle ?ABC is a right angle…

Effects of radiolysis on yttrium-90-labeled Lym-1 antibody preparations.

PubMed

Salako, Q A; O'Donnell, R T; DeNardo, S J

1998-04-01

The physical half-life of 2.6 days and 2.2 MeV beta emissions of 90Y provide excellent properties for radioimmunotherapy applications. However, the clinically useful beta particles may be a source of radiation-induced damage of 90Y-labeled immunoconjugate radiopharmaceuticals during preparation or short-term storage. The stability of 90Y-labeled Lym-1 antibody was studied in standard radiopharmacy conditions to establish a formulation at which radiolysis is not a problem. Lym-1-21T-BAD immunoconjugate intermediate was prepared according to our standard procedure, then labeled with 90Y at 1, 2, 4 and 9.4 mCi/mg Lym-1 using 0.5 M tetramethylammonium acetate, pH 7, labeling buffer. Each mixture was challenged in diethylenetriaminepentaacetic acid to remove nonspecifically bound 90Y. The 90Y-21T-BAD-Lym-1 products were purified by centrifuged molecular sieving column chromatography. The radiochemical purity and immunoreactivity of each preparation was monitored daily by high-performance liquid chromatography (HPLC) and solid-phase radioimmunoassay, respectively, for 3 days. The preparation at 2 mCi/mg was also formulated in 4% (wt/vol) human serum albumin (HSA) overall and at 9.4 mCi/mg in five-fold water, 4 and 10% (wt/vol) HSA overall; all were monitored as above. The monomeric quality and purity profile of products at 1 and 2 mCi/mg were retained (> or = 80%) as was their immunoreactivity (> or = 75%) over 3 days. The radiochemical purity and immunoreactivity of the product at 4 mCi/mg declined to 65% and 28%, respectively, by 3 days after preparation and in just 48 hr, the product at 9.4 mCi/mg had degraded to 21% in radiochemical purity with only 3% immunoreactivity. The current HPLC data and earlier published chromatographic evidence did not support a compromised radiochemical integrity of 90Y-DOTA complexes by loss of 90Y from the DOTA chelate. Radiolysis of 90Y-labeled antibody preparations did not appear to be a problem at 90Y-21T-BAD-Lym-1 products < or = 2 m

Hybrid-integrated coherent receiver using silica-based planar lightwave circuit technology

NASA Astrophysics Data System (ADS)

Kim, Jong-Hoi; Choe, Joong-Seon; Choi, Kwang-Seong; Youn, Chun-Ju; Kim, Duk-Jun; Jang, Sun-Hyok; Kwon, Yong-Hwan; Nam, Eun-Soo

2011-12-01

A hybrid-integrated coherent receiver module has been achieved using flip-chip bonding technology, consisting of a silica-based 90°-hybrid planar lightwave circuit (PLC) platform, a spot-size converter integrated waveguide photodiode (SSC-WG-PD), and a dual-channel transimpedance amplifier (TIA). The receiver module shows error-free operation up to 40Gb/s and OSNR sensitivity of 11.5 dB for BER = 10-3 at 25 Gb/s.

SU-F-J-182: Investigation of Systems for Improved Accuracy in Clinical Y-90 Percent Delivered Calculations

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

McBeth, R; Elder, D; Kesner, A

2016-06-15

Purpose: Y-90 Selective Internal Radiation Therapy (SIRT) is used to treat liver tumors, and by nature has variability in the percent of the intended dose that is actually delivered. To determine the quality of the administration, pre and post activity measurements are taken, and used to infer percent delivered. Vendor specifications indicate the use of an ion chamber to take these measurements. In our work, we investigated the accuracy of ion chambers, and compared them to other detector systems. Methods: We have built phantoms, phantom holders, and protocols, which allow us to measure our Y90 doses with varying apparatuses: amore » dose calibrator, a Geiger-counter, an ion chamber, a crystal based thyroid probe, and a gamma camera. We have set up a system that has enabled us to gather data by measuring clinical Y90 doses as they are used in the clinic using all of the instrumental methods. Five initial doses (25 measurements/acquisitions) have been taken at the time of this abstract submission. Results: Our initial results show that measurements acquired using scintillation based detectors (thyroid probe and gamma camera) correlate better with the gold standard (i.e. the dose calibrator). Pearson correlations between the dose calibrator measurements and the GM counter, Ion chamber, thyroid probe, and gamma camera were found to be 0.88, 0.83, 0.98, 0.99, respectively. More acquisitions and analysis are planned to determine the precision of the systems, as well as optimal energy window settings. Conclusion: It is likely that current standard practice can be improved using scintillation crystal based detectors. Such systems are more sensitive, can integrate signal, and can use energy discrimination. Furthermore, phantoms can be built to integrate with probe and gamma camera systems that are robust and provide reproducibility. Future work will include expanded acquisition and analysis.« less

Experiments in Radiochemistry: Paper Electrophorectic Separation of Superscript 90 Sr and Superscript 90 Y.

ERIC Educational Resources Information Center

Miekely, N.; Roldao, L. A.

1982-01-01

Using different supporting electrolytes, the influence of complex-forming equilibria on migration velocities of strontium-90 and yttrium-90 can be demonstrated in this experiment. Includes procedures and materials needed. (SK)

Predictive Value of 99mTc-MAA SPECT for 90Y-Labeled Resin Microsphere Distribution in Radioembolization of Primary and Secondary Hepatic Tumors.

PubMed

Ilhan, Harun; Goritschan, Anna; Paprottka, Philipp; Jakobs, Tobias F; Fendler, Wolfgang P; Todica, Andrei; Bartenstein, Peter; Hacker, Marcus; Haug, Alexander R

2015-11-01

This study analyzed the predictive value of (99m)Tc-labeled macroaggregated albumin ((99m)Tc-MAA) SPECT for (90)Y-labeled resin microsphere therapy (radioembolization) by comparing uptake on pretherapeutic (99m)Tc-MAA SPECT with uptake on posttherapeutic (90)Y-bremsstrahlung SPECT. We included 502 patients (55% male; mean age ± SD, 62 ± 11 y) who underwent radioembolization between 2005 and 2013 because of primary or secondary liver malignancies (colorectal cancer [n = 195, 38.8%], neuroendocrine tumors [n = 77, 15.3%], breast cancer [n = 68, 13.5%], hepatocellular carcinoma [n = 59, 11.8%], cholangiocellular carcinoma [n = 40, 8.0%], or urologic tumors [n = 14, 2.8%]). Manually drawn regions of interest around tumors and adjacent healthy liver tissue for up to 3 lesions per patient on (99m)Tc-MAA and (90)Y-bremsstrahlung scans were used to quantify mean counts per pixel and evaluate the mean tumor-to-background ratio (TBR). Data were given as mean ± SD. Additionally, uptake in lesions on (99m)Tc-MAA and (90)Y-bremsstrahlung scans was graded visually as homogeneously higher than (grade 1), heterogeneously higher than (grade 2), equal to (grade 3), or lower than (grade 4) uptake in normal liver tissue. The Mann-Whitney U test and Spearman correlation were used to evaluate statistically significant differences between (99m)Tc-MAA and (90)Y-bremsstrahlung SPECT. In total, 1,008 lesions were analyzed. Of the 23% (230/1,008) of lesions that had grade 1 uptake on (99m)Tc-MAA SPECT, 81% (186/230) remained grade 1 after radioembolization whereas 16% (37/230) were grade 2. Of the lesions with grade 2 uptake on (99m)Tc-MAA SPECT, 16% had grade 1 uptake and 82% grade 2 uptake after radioembolization. Of the lesions with grade 3 uptake, however, 27% had grade 1 uptake and 47% grade 2 uptake after radioembolization. Even among the lesions with grade 4 uptake on (99m)Tc-MAA SPECT, 21% had grade 1 uptake and 46% grade 2 uptake after radioembolization. The mean TBR on (99m

Effect of pulmonary irradiation from inhaled /sup 90/Y on immunity to Listeria monocytogenes in mice

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

Sanchez, A.; Lundgren, D.L.; McClellan, R.O.

1976-01-01

The immunological response of mice subjected to irradiation from particles deposited in the lungs and challenged with Listeria monocytogenes was investigated. Mice, exposed by inhalation to /sup 90/Y (a beta-emitting radionuclide) in relatively insoluble fused aluminosilicate particles, were immunized with L. monocytogenes either before or after exposure. Two additional groups of mice were either immunized or irradiated only. A group of control mice received no irradiation or immunization. The beta radiation dose absorbed by the lungs of each mouse at time of challenge averaged 10,000 rads. Fourteen days after immunization, all mice were challenged with 2 LD/sub 50/ doses ofmore » L. monocytogenes via the respiratory route. Survival of all immunized mice either with or without exposure to /sup 90/Y varied from 90 to 100% as compared to 10 to 20% for the mice irradiated only and for control mice through 14 days after challenge. Pulmonary clearance of inhaled L. monocytogenes during the first 4 hr after challenge was suppressed in the mice irradiated only but not in those immunized only, or in the immunized and irradiated groups, and control mice. There appeared to be a suppression of proliferation of L. monocytogenes in lungs and spleen in the immunized groups 72 hr after challenge, whereas the lungs and spleens of the mice irradiated only and the control mice had extensive bacterial invasion. It was concluded that the 10,000 rads of beta radiation absorbed by the lungs did not suppress the immune mechanisms of the immunized mice.« less

Process for the separation and purification of yttrium-90 for medical applications

DOEpatents

Horwitz, P.E.; Dietz, M.L.

1994-11-29

An extraction chromatographic method for the preparation of [sup 90]Y of high chemical and radiochemical purity is disclosed. After an initial purification of a [sup 90]Sr stock solution and a suitable period of [sup 90]Y ingrowth, the solution is passed through a series of strontium-selective chromatographic columns, each of which lowers the [sup 90]Sr content of the mixture by a factor of about 10[sup 3]. The [sup 90]Y remaining is freed from any residual [sup 90]Sr, from its [sup 90]Zr daughter, and from any remaining impurities by passing the sample through a final column designed to selectively retain yttrium. 5 figures.

Process for the separation and purification of yttrium-90 for medical applications

DOEpatents

Horwitz, Philip E.; Dietz, Mark L.

1994-01-01

An extraction chromatographic method for the preparation of .sup.90 Y of high chemical and radiochemical purity is disclosed. After an initial purification of a .sup.90 Sr stock solution and a suitable period of .sup.90 Y ingrowth, the solution is passed through a series of strontium-selective chromatographic columns, each of which lowers the .sup.90 Sr content of the mixture by a factor of about 10.sup.3. The .sup.90 Y remaining is freed from any residual .sup.90 Sr, from its .sup.90 Zr daughter, and from any remaining impurities by passing the sample through a final column designed to selectively retain yttrium.

Analysis and design of planar and non-planar wings for induced drag minimization

NASA Technical Reports Server (NTRS)

Mortara, K.; Straussfogel, Dennis M.; Maughmer, Mark D.

1991-01-01

The goal of the work was to develop and validate computational tools to be used for the design of planar and non-planar wing geometries for minimum induced drag. Because of the iterative nature of the design problem, it is important that, in addition to being sufficiently accurate for the problem at hand, they are reasonably fast and computationally efficient. Toward this end, a method of predicting induced drag in the presence of a non-rigid wake is coupled with a panel method. The induced drag prediction technique is based on the Kutta-Joukowski law applied at the trailing edge. Until recently, the use of this method has not been fully explored and pressure integration and Trefftz-plane calculations favored. As is shown in this report, however, the Kutta-Joukowski method is able to give better results for a given amount of effort than the more common techniques, particularly when relaxed wakes and non-planar wing geometries are considered. Using these tools, a workable design method is in place which takes into account relaxed wakes and non-planar wing geometries. It is recommended that this method be used to design a wind-tunnel experiment to verify the predicted aerodynamic benefits of non-planar wing geometries.

New 2-D dosimetric technique for radiotherapy based on planar thermoluminescent detectors.

PubMed

Olko, P; Marczewska, B; Czopyk, L; Czermak, M A; Klosowski, M; Waligórski, M P R

2006-01-01

At the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ) in Kraków, a two-dimensional (2-D) thermoluminescence (TL) dosimetry system was developed within the MAESTRO (Methods and Advanced Equipment for Simulation and Treatment in Radio-Oncology) 6 Framework Programme and tested by evaluating 2-D dose distributions around radioactive sources. A thermoluminescent detector (TLD) foil was developed, of thickness 0.3 mm and diameter 60 mm, containing a mixture of highly sensitive LiF:Mg,Cu,P powder and Ethylene TetraFluoroEthylene (ETFE) polymer. Foil detectors were irradiated with (226)Ra brachytherapy sources and a (90)Sr/(90)Y source. 2-D dose distributions were evaluated using a prototype planar (diameter 60 mm) reader, equipped with a 12 bit Charge Coupled Devices (CCD) PCO AG camera, with a resolution of 640 x 480 pixels. The new detectors, showing a spatial resolution better than 0.5 mm and a measurable dose range typical for radiotherapy, can find many applications in clinical dosimetry. Another technology applicable to clinical dosimetry, also developed at IFJ, is the Si microstrip detector of size 95 x 95 mm(2), which may be used to evaluate the dose distribution with a spatial resolution of 120 microm along one direction, in real-time mode. The microstrip and TLD technology will be further improved, especially to develop detectors of larger area, and to make them applicable to some advanced radiotherapy modalities, such as intensity modulated radiotherapy (IMRT) or proton radiotherapy.

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

Siman, W.; Mikell, J. K.; Kappadath, S. C., E-mail

Purpose: To develop a practical background compensation (BC) technique to improve quantitative {sup 90}Y-bremsstrahlung single-photon emission computed tomography (SPECT)/computed tomography (CT) using a commercially available imaging system. Methods: All images were acquired using medium-energy collimation in six energy windows (EWs), ranging from 70 to 410 keV. The EWs were determined based on the signal-to-background ratio in planar images of an acrylic phantom of different thicknesses (2–16 cm) positioned below a {sup 90}Y source and set at different distances (15–35 cm) from a gamma camera. The authors adapted the widely used EW-based scatter-correction technique by modeling the BC as scaled images.more » The BC EW was determined empirically in SPECT/CT studies using an IEC phantom based on the sphere activity recovery and residual activity in the cold lung insert. The scaling factor was calculated from 20 clinical planar {sup 90}Y images. Reconstruction parameters were optimized in the same SPECT images for improved image quantification and contrast. A count-to-activity calibration factor was calculated from 30 clinical {sup 90}Y images. Results: The authors found that the most appropriate imaging EW range was 90–125 keV. BC was modeled as 0.53× images in the EW of 310–410 keV. The background-compensated clinical images had higher image contrast than uncompensated images. The maximum deviation of their SPECT calibration in clinical studies was lowest (<10%) for SPECT with attenuation correction (AC) and SPECT with AC + BC. Using the proposed SPECT-with-AC + BC reconstruction protocol, the authors found that the recovery coefficient of a 37-mm sphere (in a 10-mm volume of interest) increased from 39% to 90% and that the residual activity in the lung insert decreased from 44% to 14% over that of SPECT images with AC alone. Conclusions: The proposed EW-based BC model was developed for {sup 90}Y bremsstrahlung imaging. SPECT with AC + BC gave improved

Planarity constrained multi-view depth map reconstruction for urban scenes

NASA Astrophysics Data System (ADS)

Hou, Yaolin; Peng, Jianwei; Hu, Zhihua; Tao, Pengjie; Shan, Jie

2018-05-01

Multi-view depth map reconstruction is regarded as a suitable approach for 3D generation of large-scale scenes due to its flexibility and scalability. However, there are challenges when this technique is applied to urban scenes where apparent man-made regular shapes may present. To address this need, this paper proposes a planarity constrained multi-view depth (PMVD) map reconstruction method. Starting with image segmentation and feature matching for each input image, the main procedure is iterative optimization under the constraints of planar geometry and smoothness. A set of candidate local planes are first generated by an extended PatchMatch method. The image matching costs are then computed and aggregated by an adaptive-manifold filter (AMF), whereby the smoothness constraint is applied to adjacent pixels through belief propagation. Finally, multiple criteria are used to eliminate image matching outliers. (Vertical) aerial images, oblique (aerial) images and ground images are used for qualitative and quantitative evaluations. The experiments demonstrated that the PMVD outperforms the popular multi-view depth map reconstruction with an accuracy two times better for the aerial datasets and achieves an outcome comparable to the state-of-the-art for ground images. As expected, PMVD is able to preserve the planarity for piecewise flat structures in urban scenes and restore the edges in depth discontinuous areas.

Immune activation underlies a sustained clinical response to Yttrium-90 radioembolisation in hepatocellular carcinoma.

PubMed

Chew, Valerie; Lee, Yun Hua; Pan, Lu; Nasir, Nurul J M; Lim, Chun Jye; Chua, Camillus; Lai, Liyun; Hazirah, Sharifah Nur; Lim, Tony Kiat Hon; Goh, Brian K P; Chung, Alexander; Lo, Richard H G; Ng, David; Filarca, Rene L F; Albani, Salvatore; Chow, Pierce K H

2018-02-13

Yttrium-90 (Y90)-radioembolisation (RE) significantly regresses locally advanced hepatocellular carcinoma and delays disease progression. The current study is designed to deeply interrogate the immunological impact of Y90-RE, which elicits a sustained therapeutic response. Time-of-flight mass cytometry and next-generation sequencing (NGS) were used to analyse the immune landscapes of tumour-infiltrating leucocytes (TILs), tumour tissues and peripheral blood mononuclear cells (PBMCs) at different time points before and after Y90-RE. TILs isolated after Y90-RE exhibited signs of local immune activation: higher expression of granzyme B (GB) and infiltration of CD8 + T cells, CD56 + NK cells and CD8 + CD56 + NKT cells. NGS confirmed the upregulation of genes involved in innate and adaptive immune activation in Y90-RE-treated tumours. Chemotactic pathways involving CCL5 and CXCL16 correlated with the recruitment of activated GB + CD8 + T cells to the Y90-RE-treated tumours. When comparing PBMCs before and after Y90-RE, we observed an increase in tumour necrosis factor-α on both the CD8 + and CD4 + T cells as well as an increase in percentage of antigen-presenting cells after Y90-RE, implying a systemic immune activation. Interestingly, a high percentage of PD-1 + /Tim-3 + CD8 + T cells coexpressing the homing receptors CCR5 and CXCR6 denoted Y90-RE responders. A prediction model was also built to identify sustained responders to Y90-RE based on the immune profiles from pretreatment PBMCs. High-dimensional analysis of tumour and systemic immune landscapes identified local and systemic immune activation that corresponded to the sustained response to Y90-RE. Potential biomarkers associated with a positive clinical response were identified and a prediction model was built to identify sustained responders prior to treatment. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is

Polymer planar lightwave circuit based hybrid-integrated coherent receiver for advanced modulation signals

NASA Astrophysics Data System (ADS)

Wang, Jin; Han, Yang; Liang, Zhongcheng; Chen, Yongjin

2012-11-01

Applying coherent detection technique to advanced modulation formats makes it possible to electronically compensate the signal impairments. A key issue for a successful deployment of coherent detection technique is the availability of cost-efficient and compact integrated receivers, which are composed of an optical 90° hybrid mixer and four photodiodes (PDs). In this work, three different types of optical hybrids are fabricated with polymer planar lightwave circuit (PLC), and hybridly integrated with four vertical backside illuminated III-V PDs. Their performances, such as the insertion loss, the transmission imbalance, the polarization dependence and the phase deviation of 90° hybrid will be discussed.

An ultrathin terahertz quarter-wave plate using planar babinet-inverted metasurface.

PubMed

Wang, Dacheng; Gu, Yinghong; Gong, Yandong; Qiu, Cheng-Wei; Hong, Minghui

2015-05-04

Metamaterials promise an exotic approach to artificially manipulate the polarization state of electromagnetic waves and boost the design of polarimetric devices for sensitive detection, imaging and wireless communication. Here, we present the design and experimental demonstration of an ultrathin (0.29λ) terahertz quarter-wave plate based on planar babinet-inverted metasurface. The quarter-wave plate consisting of arrays of asymmetric cross apertures reveals a high transmission of 0.545 with 90 degrees phase delay at 0.870 THz. The calculated ellipticity indicates a high degree of polarization conversion from linear to circular polarization. With respect to different incident polarization angles, left-handed circular polarized light, right-handed circular polarized light and elliptically polarized light can be created by this novel design. An analytical model is applied to describe transmitted amplitude, phase delay and ellipticitiy, which are in good agreement with the measured and simulated results. The planar babinet-inverted metasurface with the analytical model opens up avenues for new functional terahertz devices design.

Comparison of TOF-PET and Bremsstrahlung SPECT Images of Yttrium-90: A Monte Carlo Simulation Study.

PubMed

Takahashi, Akihiko; Himuro, Kazuhiko; Baba, Shingo; Yamashita, Yasuo; Sasaki, Masayuki

2018-01-01

Yttrium-90 ( 90 Y) is a beta particle nuclide used in targeted radionuclide therapy which is available to both single-photon emission computed tomography (SPECT) and time-of-flight (TOF) positron emission tomography (PET) imaging. The purpose of this study was to assess the image quality of PET and Bremsstrahlung SPECT by simulating PET and SPECT images of 90 Y using Monte Carlo simulation codes under the same conditions and to compare them. In-house Monte Carlo codes, MCEP-PET and MCEP-SPECT, were employed to simulate images. The phantom was a torso-shaped phantom containing six hot spheres of various sizes. The background concentrations of 90 Y were set to 50, 100, 150, and 200 kBq/mL, and the concentrations of the hot spheres were 10, 20, and 40 times of those of the background concentrations. The acquisition time was set to 30 min, and the simulated sinogram data were reconstructed using the ordered subset expectation maximization method. The contrast recovery coefficient (CRC) and contrast-to-noise ratio (CNR) were employed to evaluate the image qualities. The CRC values of SPECT images were less than 40%, while those of PET images were more than 40% when the hot sphere was larger than 20 mm in diameter. The CNR values of PET images of hot spheres of diameter smaller than 20 mm were larger than those of SPECT images. The CNR values mostly exceeded 4, which is a criterion to evaluate the discernibility of hot areas. In the case of SPECT, hot spheres of diameter smaller than 20 mm were not discernable. On the contrary, the CNR values of PET images decreased to the level of SPECT, in the case of low concentration. In almost all the cases examined in this investigation, the quantitative indexes of TOF-PET 90 Y images were better than those of Bremsstrahlung SPECT images. However, the superiority of PET image became critical in the case of low activity concentrations.

Planarization of metal films for multilevel interconnects

DOEpatents

Tuckerman, D.B.

1985-06-24

In the fabrication of multilevel integrated circuits, each metal layer is planarized by heating to momentarily melt the layer. The layer is melted by sweeping lase pulses of suitable width, typically about 1 microsecond duration, over the layer in small increments. The planarization of each metal layer eliminates irregular and discontinuous conditions between successive layers. The planarization method is particularly applicable to circuits having ground or power planes and allows for multilevel interconnects. Dielectric layers can also be planarized to produce a fully planar multilevel interconnect structure. The method is useful for the fabrication of VLSI circuits, particularly for wafer-scale integration.

Planarization of metal films for multilevel interconnects

DOEpatents

Tuckerman, D.B.

1985-08-23

In the fabrication of multilevel integrated circuits, each metal layer is planarized by heating to momentarily melt the layer. The layer is melted by sweeping laser pulses of suitable width, typically about 1 microsecond duration, over the layer in small increments. The planarization of each metal layer eliminates irregular and discontinuous conditions between successive layers. The planarization method is particularly applicable to circuits having ground or power planes and allows for multilevel interconnects. Dielectric layers can also be planarized to produce a fully planar multilevel interconnect structure. The method is useful for the fabrication of VLSI circuits, particularly for wafer-scale integration.

A process for the separation and purification of yttrium-90 for medical applications

DOEpatents

Horwitz, P.E.; Dietz, M.L.

1993-01-01

An extraction chromatographic method for the preparation of {sup 90}Y of high chemical and radiochemical purity is disclosed. After an initial purification of a {sup 90}Sr stock solution and a suitable period of {sup 90}Y ingrowth, the solution is passed through a series of strontium-selective chromatographic columns, each of which lowers the {sup 90}Sr content of the mixture by a factor of about 10{sup 3}. The {sup 90}Y remaining is freed from any residual {sup 90}Sr, from its {sup 90}Zr daughter, and from any remaining impurities by passing the sample through a final column designed to selectively retain yttrium.

Monomer volume fraction profiles in pH responsive planar polyelectrolyte brushes

DOE PAGES

Mahalik, Jyoti P.; Yang, Yubo; Deodhar, Chaitra V.; ...

2016-03-06

Spatial dependencies of monomer volume fraction profiles of pH responsive polyelectrolyte brushes were investigated using field theories and neutron reflectivity experiments. In particular, planar polyelectrolyte brushes in good solvent were studied and direct comparisons between predictions of the theories and experimental measurements are presented. The comparisons between the theories and the experimental data reveal that solvent entropy and ion-pairs resulting from adsorption of counterions from the added salt play key roles in affecting the monomer distribution and must be taken into account in modeling polyelectrolyte brushes. Furthermore, the utility of this physics-based approach based on these theories for the predictionmore » and interpretation of neutron reflectivity profiles in the context of pH responsive planar polyelectrolyte brushes such as polybasic poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and polyacidic poly(methacrylic acid) (PMAA) brushes is demonstrated. The approach provides a quantitative way of estimating molecular weights of the polymers polymerized using surface-initiated atom transfer radical polymerization.« less

Feasibility assessment of yttrium-90 liver radioembolization imaging using amplitude-based gated PET/CT

PubMed Central

Acuff, Shelley N.; Neveu, Melissa L.; Syed, Mumtaz; Kaman, Austin D.; Fu, Yitong

2018-01-01

Purpose The usage of PET/computed tomography (CT) to monitor hepatocellular carcinoma patients following yttrium-90 (90Y) radioembolization has increased. Respiratory motion causes liver movement, which can be corrected using gating techniques at the expense of added noise. This work examines the use of amplitude-based gating on 90Y-PET/CT and its potential impact on diagnostic integrity. Patients and methods Patients were imaged using PET/CT following 90Y radioembolization. A respiratory band was used to collect respiratory cycle data. Patient data were processed as both standard and motion-corrected images. Regions of interest were drawn and compared using three methods. Activity concentrations were calculated and converted into dose estimates using previously determined and published scaling factors. Diagnostic assessments were performed using a binary scale created from published 90Y-PET/CT image interpretation guidelines. Results Estimates of radiation dose were increased (P<0.05) when using amplitude-gating methods with 90Y PET/CT imaging. Motion-corrected images show increased noise, but the diagnostic determination of success, using the Kao criteria, did not change between static and motion-corrected data. Conclusion Amplitude-gated PET/CT following 90Y radioembolization is feasible and may improve 90Y dose estimates while maintaining diagnostic assessment integrity. PMID:29351124

Stability of planar traveling waves in a Keller-Segel equation on an infinite strip domain

NASA Astrophysics Data System (ADS)

Chae, Myeongju; Choi, Kyudong; Kang, Kyungkeun; Lee, Jihoon

2018-07-01

We consider a simplified model of tumor angiogenesis, described by a Keller-Segel equation on the two dimensional domain (x , y) ∈ R ×Sλ where Sλ is the circle of perimeter λ. It is known that the system allows planar traveling wave solutions of an invading type. In case that λ is sufficiently small, we establish the nonlinear stability of traveling wave solutions in the absence of chemical diffusion if the initial perturbation is sufficiently small in some weighted Sobolev space. When chemical diffusion is present, it can be shown that the system is linearly stable. Lastly, we prove that any solution with our front condition eventually becomes planar under certain regularity conditions.

Planarization of metal films for multilevel interconnects

DOEpatents

Tuckerman, D.B.

1989-03-21

In the fabrication of multilevel integrated circuits, each metal layer is planarized by heating to momentarily melt the layer. The layer is melted by sweeping laser pulses of suitable width, typically about 1 microsecond duration, over the layer in small increments. The planarization of each metal layer eliminates irregular and discontinuous conditions between successive layers. The planarization method is particularly applicable to circuits having ground or power planes and allows for multilevel interconnects. Dielectric layers can also be planarized to produce a fully planar multilevel interconnect structure. The method is useful for the fabrication of VLSI circuits, particularly for wafer-scale integration. 6 figs.

Effects of planar and non-planar driver-side mirrors on age-related discomfort-glare responses

PubMed Central

Lockhart, Thurmon E.; Atsumi, Bunji; Ghosh, Arka; Mekaroonreung, Haruetai; Spaulding, Jeremy

2010-01-01

In this study, we evaluated subjective nighttime discomfort-glare responses on three different types of planar and non-planar driver-side mirrors on two age groups. Fifty-six individuals (28 young [18–35 years] and 28 old [65 years and over]) participated in this experiment. Subjective discomfort-glare rating scores on three different types of driver-side mirrors were assessed utilizing De Boer's rating scale in a controlled nighttime driving environment (laboratory ambient illuminant level—l lux with headlight turned off). Three driver-side mirrors included planar “flat mirror”: radius of curvature 242650.92 mm, reflectivity 0.60114, and surface reflectance 0.60568; “curved mirror”: radius of curvature 1433.3 mm, reflectivity 0.21652, and surface reflectance 0.58092; “blue mirror”: radius of curvature 1957.1 mm, reflectivity 0.25356, and surface reflectance 0.54585. The results indicated that with the same glare level (as measured by angle of incidence and illuminance in front of the eyes), older adults reported worse feelings of glare than their younger counterparts. Furthermore, the results indicated that both young and older adults reported worse feelings of glare for planar driver-side mirror than non-planar driver-side mirrors. These results suggest that older adults' criterion of discomfort-glare is more sensitive than their younger counterparts, and importantly, the non-planar driver-side mirrors can be beneficial in terms of reducing nighttime discomfort-glare for both the young and the elderly. PMID:20582252

Self-Paced Reaching after Stroke: A Quantitative Assessment of Longitudinal and Directional Sensitivity Using the H-Man Planar Robot for Upper Limb Neurorehabilitation.

PubMed

Hussain, Asif; Budhota, Aamani; Hughes, Charmayne Mary Lee; Dailey, Wayne D; Vishwanath, Deshmukh A; Kuah, Christopher W K; Yam, Lester H L; Loh, Yong J; Xiang, Liming; Chua, Karen S G; Burdet, Etienne; Campolo, Domenico

2016-01-01

Technology aided measures offer a sensitive, accurate and time-efficient approach for the assessment of sensorimotor function after neurological insult compared to standard clinical assessments. This study investigated the sensitivity of robotic measures to capture differences in planar reaching movements as a function of neurological status (stroke, healthy), direction (front, ipsilateral, contralateral), movement segment (outbound, inbound), and time (baseline, post-training, 2-week follow-up) using a planar, two-degrees of freedom, robotic-manipulator (H-Man). Twelve chronic stroke (age: 55 ± 10.0 years, 5 female, 7 male, time since stroke: 11.2 ± 6.0 months) and nine aged-matched healthy participants (age: 53 ± 4.3 years, 5 female, 4 male) participated in this study. Both healthy and stroke participants performed planar reaching movements in contralateral, ipsilateral and front directions with the H-Man, and the robotic measures, spectral arc length (SAL), normalized time to peak velocities ( T peakN ), and root-mean square error (RMSE) were evaluated. Healthy participants went through a one-off session of assessment to investigate the baseline. Stroke participants completed a 2-week intensive robotic training plus standard arm therapy (8 × 90 min sessions). Motor function for stroke participants was evaluated prior to training (baseline, week-0), immediately following training (post-training, week-2), and 2-weeks after training (follow-up, week-4) using robotic assessment and the clinical measures Fugl-Meyer Assessment (FMA), Activity-Research-Arm Test (ARAT), and grip-strength. Robotic assessments were able to capture differences due to neurological status, movement direction, and movement segment. Movements performed by stroke participants were less-smooth, featured longer T peakN , and larger RMSE values, compared to healthy controls. Significant movement direction differences were observed, with improved reaching performance for the front, compared to

Integration of planar transformer and/or planar inductor with power switches in power converter

DOEpatents

Chen, Kanghua; Ahmed, Sayeed; Zhu, Lizhi

2007-10-30

A power converter integrates at least one planar transformer comprising a multi-layer transformer substrate and/or at least one planar inductor comprising a multi-layer inductor substrate with a number of power semiconductor switches physically and thermally coupled to a heat sink via one or more multi-layer switch substrates.

In vitro quantification of the performance of model-based mono-planar and bi-planar fluoroscopy for 3D joint kinematics estimation.

PubMed

Tersi, Luca; Barré, Arnaud; Fantozzi, Silvia; Stagni, Rita

2013-03-01

Model-based mono-planar and bi-planar 3D fluoroscopy methods can quantify intact joints kinematics with performance/cost trade-off. The aim of this study was to compare the performances of mono- and bi-planar setups to a marker-based gold-standard, during dynamic phantom knee acquisitions. Absolute pose errors for in-plane parameters were lower than 0.6 mm or 0.6° for both mono- and bi-planar setups. Mono-planar setups resulted critical in quantifying the out-of-plane translation (error < 6.5 mm), and bi-planar in quantifying the rotation along bone longitudinal axis (error < 1.3°). These errors propagated to joint angles and translations differently depending on the alignment of the anatomical axes and the fluoroscopic reference frames. Internal-external rotation was the least accurate angle both with mono- (error < 4.4°) and bi-planar (error < 1.7°) setups, due to bone longitudinal symmetries. Results highlighted that accuracy for mono-planar in-plane pose parameters is comparable to bi-planar, but with halved computational costs, halved segmentation time and halved ionizing radiation dose. Bi-planar analysis better compensated for the out-of-plane uncertainty that is differently propagated to relative kinematics depending on the setup. To take its full benefits, the motion task to be investigated should be designed to maintain the joint inside the visible volume introducing constraints with respect to mono-planar analysis.

Method for rapid screening analysis of Sr-90 in edible plant samples collected near Fukushima, Japan.

PubMed

Amano, Hikaru; Sakamoto, Hideaki; Shiga, Norikatsu; Suzuki, Kaori

2016-06-01

A screening method for measuring (90)Sr in edible plant samples by focusing on (90)Y in equilibrium with (90)Sr is reported. (90)Y was extracted from samples with acid, co-precipitated with iron hydroxide, and precipitated with oxalic acid. The dissolved oxalate precipitate was loaded on an extraction chromatography resin, and the (90)Y-enriched eluate was analyzed by Cherenkov counting with a TDCR liquid scintillation counter. (90)Sr ((90)Y) concentration was determined in plant samples collected near the damaged Fukushima Daiichi Nuclear Power Plants with this method. Copyright © 2016 Elsevier Ltd. All rights reserved.

Early Dose Response to Yttrium-90 Microsphere Treatment of Metastatic Liver Cancer by a Patient-Specific Method Using Single Photon Emission Computed Tomography and Positron Emission Tomography

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

Campbell, Janice M.; Department of Radiation Oncology, Wayne State University, Detroit, MI; Wong, C. Oliver

2009-05-01

Purpose: To evaluate a patient-specific single photon emission computed tomography (SPECT)-based method of dose calculation for treatment planning of yttrium-90 ({sup 90}Y) microsphere selective internal radiotherapy (SIRT). Methods and Materials: Fourteen consecutive {sup 90}Y SIRTs for colorectal liver metastasis were retrospectively analyzed. Absorbed dose to tumor and normal liver tissue was calculated by partition methods with two different tumor/normal liver vascularity ratios: an average 3:1 and a patient-specific ratio derived from pretreatment technetium-99m macroaggregated albumin SPECT. Tumor response was quantitatively evaluated from fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography scans. Results: Positron emission tomography showed a significant decrease in total tumor standardizedmore » uptake value (average, 52%). There was a significant difference in the tumor absorbed dose between the average and specific methods (p = 0.009). Response vs. dose curves fit by linear and linear-quadratic modeling showed similar results. Linear fit r values increased for all tumor response parameters with the specific method (+0.20 for mean standardized uptake value). Conclusion: Tumor dose calculated with the patient-specific method was more predictive of response in liver-directed {sup 90}Y SIRT.« less

Planar photovoltaic solar concentrator module

DOEpatents

Chiang, Clement J.

1992-01-01

A planar photovoltaic concentrator module for producing an electrical signal from incident solar radiation includes an electrically insulating housing having a front wall, an opposing back wall and a hollow interior. A solar cell having electrical terminals is positioned within the interior of the housing. A planar conductor is connected with a terminal of the solar cell of the same polarity. A lens forming the front wall of the housing is operable to direct solar radiation incident to the lens into the interior of the housing. A refractive optical element in contact with the solar cell and facing the lens receives the solar radiation directed into the interior of the housing by the lens and directs the solar radiation to the solar cell to cause the solar cell to generate an electrical signal. An electrically conductive planar member is positioned in the housing to rest on the housing back wall in supporting relation with the solar cell terminal of opposite polarity. The planar member is operable to dissipate heat radiated by the solar cell as the solar cell generates an electrical signal and further forms a solar cell conductor connected with the solar cell terminal to permit the electrical signal generated by the solar cell to be measured between the planar member and the conductor.

Dose Range Evaluation of Mycograb C28Y Variant, a Human Recombinant Antibody Fragment to Heat Shock Protein 90, in Combination with Amphotericin B-Desoxycholate for Treatment of Murine Systemic Candidiasis ▿

PubMed Central

Louie, Arnold; Stein, Daniel S.; Zack, Julia Z.; Liu, Weiguo; Conde, Haley; Fregeau, Christine; VanScoy, Brian D.; Drusano, George L.

2011-01-01

Systemic candidiasis causes significant mortality in patients despite amphotericin B (AMB) therapy. Mycograb C28Y variant, a human recombinant antibody fragment to heat shock protein 90, is closely related to Mycograb, which showed a survival advantage in combination with AMB in a phase III human trial. The Mycograb C28Y variant could potentially increase the antifungal effect of AMB. In our study, the interaction between AMB-desoxycholate (DAMB) and the Mycograb C28Y variant was characterized in vitro by using a checkerboard method. Quantitative cultures of kidneys, livers, and spleens of neutropenic mice with systemic Candida albicans infections were used to assess the in vivo interaction between 1.4 mg/kg of body weight/day of DAMB and 0.15, 1.5, and 15 mg/kg/day of the Mycograb C28Y variant after 1, 3, and 5 days of therapy. DAMB and Mycograb C28Y variant monotherapies, vehicle, and a no-treatment arm served as controls. Also, single- and multidose pharmacokinetics for the Mycograb C28Y variant were determined. Indifference or synergy between DAMB and the Mycograb C28Y variant was seen in two trials by the checkerboard method. The pharmacokinetics of the Mycograb C28Y variant was best described by a 2-compartment model with a median serum t1/2α of ∼0.198 h and a t1/2β of ∼1.77 h. In mice, DAMB together with the Mycograb C28Y variant was no more effective than AMB alone (P > 0.05 by analysis of variance). The Mycograb C28Y variant alone had no antifungal activity. We therefore conclude that the Mycograb C28Y variant in combination with DAMB offered no benefit over DAMB monotherapy in a neutropenic murine model of systemic candidiasis. PMID:21502626

Inkjet-based adaptive planarization (Conference Presentation)

NASA Astrophysics Data System (ADS)

Singhal, Shrawan; Grigas, Michelle M.; Khusnatdinov, Niyaz; Sreenivasan, Srinivasan V.

2017-03-01

Planarization is a critical unit step in the lithography process because it enables patterning of surfaces with versatile pattern density without compromising on the stringent planarity and depth-of-focus requirements. In addition to nanoscale pattern density variation, parasitics such as pre-existing wafer topography, can corrupt the desired process output after planarization. The topography of any surface can be classified in three broad categories, depending upon the amplitude and spatial wavelength of the same [1], [2]: (i) nominal shape, (ii) nanotopography and (iii) roughness. The nominal shape is given by the largest spatial wavelengths, typically < 20mm. For spatial length scales of 1-20mm, height variations at this spatial wavelength range are classified as nanotopography. Roughness usually has lower spatial wavelengths. While the nominal shape of a substrate surface is usually decided by the nature of wafer preparation and the tooling and chucking infrastructure used in the same, roughness is usually mitigated by standard polishing techniques. It is the intermediate nanotopography that is probably the most critical surface topography parameter. This is because most traditional polishing techniques cannot selectively address pre-existing substrate topography, without introducing a parasitic signature at the scale of nanotopography. Moreover, fields with pattern density variation typically also have length scales that are commensurate with nanotopography. It is thus instructive to summarize existing planarization technology to understand current limitations. Spin on Glass and Etch back is one technique used for micron scale device manufacturing [3]. As the name implies, a glass dielectric is spin-coated on the substrate followed by etching in a chemistry that ensures equal etching rates for both the sacrificial glass and the underlying film or substrate material. Photoresists may also be used instead of glass. However, the global planarity that can be

Planar photovoltaic solar concentrator module

DOEpatents

Chiang, C.J.

1992-12-01

A planar photovoltaic concentrator module for producing an electrical signal from incident solar radiation includes an electrically insulating housing having a front wall, an opposing back wall and a hollow interior. A solar cell having electrical terminals is positioned within the interior of the housing. A planar conductor is connected with a terminal of the solar cell of the same polarity. A lens forming the front wall of the housing is operable to direct solar radiation incident to the lens into the interior of the housing. A refractive optical element in contact with the solar cell and facing the lens receives the solar radiation directed into the interior of the housing by the lens and directs the solar radiation to the solar cell to cause the solar cell to generate an electrical signal. An electrically conductive planar member is positioned in the housing to rest on the housing back wall in supporting relation with the solar cell terminal of opposite polarity. The planar member is operable to dissipate heat radiated by the solar cell as the solar cell generates an electrical signal and further forms a solar cell conductor connected with the solar cell terminal to permit the electrical signal generated by the solar cell to be measured between the planar member and the conductor. 5 figs.

Growth hormone-secreting macroadenoma of the pituitary gland successfully treated with the radiolabeled somatostatin analog (90)Y-DOTATATE: case report.

PubMed

Waligórska-Stachura, Joanna; Gut, Paweł; Sawicka-Gutaj, Nadia; Liebert, Włodzimierz; Gryczyńska, Maria; Baszko-Błaszyk, Daria; Blanco-Gangoo, Al Ricardo; Ruchała, Marek

2016-08-01

Pituitary tumors causing acromegaly are usually macroadenomas at the time of diagnosis, and they can grow aggressively, infiltrating surrounding tissues. Difficulty in achieving complete tumor removal at surgery can lead toward a strong tendency for recurrence, making it necessary to consider a means of treatment other than those currently used such as somatostatin analogs (SSAs), growth hormone (GH) receptor antagonist, surgical removal, and radiotherapy. The purpose of this paper is to describe a patient diagnosed with an aggressive, giant GH-secreting tumor refractory to medical therapy but ultimately treated with the radiolabeled somatostatin analog (90)Y-DOTATATE. A 26-year-old male with an invasive macroadenoma of the pituitary gland (5.6 × 2.5 × 3.6 cm) and biochemically confirmed acromegaly underwent 2 partial tumor resections: the first used the transsphenoidal approach and the second used the transcranial method. The patient received SSAs pre- and postoperatively. Because of the progression in pituitary tumor size, he underwent classic irradiation of the tumor (50 Gy). One and a half years later, the patient presented with clinically and biochemically active disease, and the tumor size was still 52 mm in diameter (height). Two neurosurgeons disqualified him from further surgical procedures. After confirming the presence of somatostatin receptors in the pituitary tumor by using (68)Ga-DOTATATE PET/CT, we treated the patient 4 times with an SSA bound with (90)Y-DOTATATE. After this treatment, the patient attained partial biochemical remission and a reduction in the tumor mass for the first time. Treatment with an SSA bound with (90)Y-DOTATATE may be a promising option for some aggressive GH-secreting pituitary adenomas when other methods have failed.

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

Coordinated X-Y stage apparatus

DOEpatents

Morimoto, Alan K.; Kozlowski, David M.; Charles, Steven T.; Spalding, James A.

2000-01-01

An apparatus based on precision X-Y stages that are stacked. Attached to arms projecting from each X-Y stage are a set of two axis gimbals. Attached to the gimbals is a rod, which provides motion along the axis of the rod and rotation around its axis. A dual-planar apparatus that provides six degrees of freedom of motion precise to within microns of motion.

Fast simulation of yttrium-90 bremsstrahlung photons with GATE.

PubMed

Rault, Erwann; Staelens, Steven; Van Holen, Roel; De Beenhouwer, Jan; Vandenberghe, Stefaan

2010-06-01

Multiple investigators have recently reported the use of yttrium-90 (90Y) bremsstrahlung single photon emission computed tomography (SPECT) imaging for the dosimetry of targeted radionuclide therapies. Because Monte Carlo (MC) simulations are useful for studying SPECT imaging, this study investigates the MC simulation of 90Y bremsstrahlung photons in SPECT. To overcome the computationally expensive simulation of electrons, the authors propose a fast way to simulate the emission of 90Y bremsstrahlung photons based on prerecorded bremsstrahlung photon probability density functions (PDFs). The accuracy of bremsstrahlung photon simulation is evaluated in two steps. First, the validity of the fast bremsstrahlung photon generator is checked. To that end, fast and analog simulations of photons emitted from a 90Y point source in a water phantom are compared. The same setup is then used to verify the accuracy of the bremsstrahlung photon simulations, comparing the results obtained with PDFs generated from both simulated and measured data to measurements. In both cases, the energy spectra and point spread functions of the photons detected in a scintillation camera are used. Results show that the fast simulation method is responsible for a 5% overestimation of the low-energy fluence (below 75 keV) of the bremsstrahlung photons detected using a scintillation camera. The spatial distribution of the detected photons is, however, accurately reproduced with the fast method and a computational acceleration of approximately 17-fold is achieved. When measured PDFs are used in the simulations, the simulated energy spectrum of photons emitted from a point source of 90Y in a water phantom and detected in a scintillation camera closely approximates the measured spectrum. The PSF of the photons imaged in the 50-300 keV energy window is also accurately estimated with a 12.4% underestimation of the full width at half maximum and 4.5% underestimation of the full width at tenth maximum

Short- and long-term quantitation reproducibility of brain metabolites in the medial wall using proton echo planar spectroscopic imaging.

PubMed

Tsai, Shang-Yueh; Lin, Yi-Ru; Wang, Woan-Chyi; Niddam, David M

2012-11-15

Proton echo planar spectroscopic imaging (PEPSI) is a fast magnetic resonance spectroscopic imaging (MRSI) technique that allows mapping spatial metabolite distributions in the brain. Although the medial wall of the cortex is involved in a wide range of pathological conditions, previous MRSI studies have not focused on this region. To decide the magnitude of metabolic changes to be considered significant in this region, the reproducibility of the method needs to be established. The study aims were to establish the short- and long-term reproducibility of metabolites in the right medial wall and to compare regional differences using a constant short-echo time (TE30) and TE averaging (TEavg) optimized to yield glutamatergic information. 2D sagittal PEPSI was implemented at 3T using a 32 channel head coil. Acquisitions were repeated immediately and after approximately 2 weeks to assess the coefficients of variation (COV). COVs were obtained from eight regions-of-interest (ROIs) of varying size and location. TE30 resulted in better spectral quality and similar or lower quantitation uncertainty for all metabolites except glutamate (Glu). When Glu and glutamine (Gln) were quantified together (Glx) reduced quantitation uncertainty and increased reproducibility was observed for TE30. TEavg resulted in lowered quantitation uncertainty for Glu but in less reliable quantification of several other metabolites. TEavg did not result in a systematically improved short- or long-term reproducibility for Glu. The ROI volume was a major factor influencing reproducibility. For both short- and long-term repetitions, the Glu COVs obtained with TEavg were 5-8% for the large ROIs, 12-17% for the medium sized ROIs and 16-26% for the smaller cingulate ROIs. COVs obtained with TE30 for the less specific Glx were 3-5%, 8-10% and 10-15%. COVs for N-acetyl aspartate, creatine and choline using TE30 with long-term repetition were between 2-10%. Our results show that the cost of more specific

Planarization of metal films for multilevel interconnects

DOEpatents

Tuckerman, David B.

1987-01-01

In the fabrication of multilevel integrated circuits, each metal layer is anarized by heating to momentarily melt the layer. The layer is melted by sweeping laser pulses of suitable width, typically about 1 microsecond duration, over the layer in small increments. The planarization of each metal layer eliminates irregular and discontinuous conditions between successive layers. The planarization method is particularly applicable to circuits having ground or power planes and allows for multilevel interconnects. Dielectric layers can also be planarized to produce a fully planar multilevel interconnect structure. The method is useful for the fabrication of VLSI circuits, particularly for wafer-scale integration.

Planarization of metal films for multilevel interconnects

DOEpatents

Tuckerman, David B.

1989-01-01

In the fabrication of multilevel integrated circuits, each metal layer is anarized by heating to momentarily melt the layer. The layer is melted by sweeping laser pulses of suitable width, typically about 1 microsecond duration, over the layer in small increments. The planarization of each metal layer eliminates irregular and discontinuous conditions between successive layers. The planarization method is particularly applicable to circuits having ground or power planes and allows for multilevel interconnects. Dielectric layers can also be planarized to produce a fully planar multilevel interconnect structure. The method is useful for the fabrication of VLSI circuits, particularly for wafer-scale integration.

Chemoembolic Hepatopulmonary Shunt Reduction to Allow Safe Yttrium-90 Radioembolization Lobectomy of Hepatocellular Carcinoma

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

Gaba, Ron C., E-mail: rgaba@uic.edu; VanMiddlesworth, Kyle A.

2012-12-15

Yttrium-90 ({sup 90}Y) radioembolization represents an emerging transcatheter treatment option for the management of hepatocellular carcinoma (HCC). Elevation of the hepatopulmonary shunt fraction risks nontarget radiation to the lungs and may limit the use of {sup 90}Y therapy in patients with locally advanced disease with vascular invasion, who often demonstrate increased shunting. We present two cases in which patients with HCC and portal vein invasion resulting in elevated hepatopulmonary shunt fractions underwent chemoembolic shunt closure to allow safe {sup 90}Y radioembolization. Both patients demonstrated excellent tumor response and patient survival. On this basis, we propose a role for chemoembolic reductionmore » of the lung shunt fraction before {sup 90}Y radioembolization in patients with extensive tumor-related hepatopulmonary shunting.« less

Contact planarization of ensemble nanowires

NASA Astrophysics Data System (ADS)

Chia, A. C. E.; LaPierre, R. R.

2011-06-01

The viability of four organic polymers (S1808, SC200, SU8 and Cyclotene) as filling materials to achieve planarization of ensemble nanowire arrays is reported. Analysis of the porosity, surface roughness and thermal stability of each filling material was performed. Sonication was used as an effective method to remove the tops of the nanowires (NWs) to achieve complete planarization. Ensemble nanowire devices were fully fabricated and I-V measurements confirmed that Cyclotene effectively planarizes the NWs while still serving the role as an insulating layer between the top and bottom contacts. These processes and analysis can be easily implemented into future characterization and fabrication of ensemble NWs for optoelectronic device applications.

Contact planarization of ensemble nanowires.

PubMed

Chia, A C E; LaPierre, R R

2011-06-17

The viability of four organic polymers (S1808, SC200, SU8 and Cyclotene) as filling materials to achieve planarization of ensemble nanowire arrays is reported. Analysis of the porosity, surface roughness and thermal stability of each filling material was performed. Sonication was used as an effective method to remove the tops of the nanowires (NWs) to achieve complete planarization. Ensemble nanowire devices were fully fabricated and I-V measurements confirmed that Cyclotene effectively planarizes the NWs while still serving the role as an insulating layer between the top and bottom contacts. These processes and analysis can be easily implemented into future characterization and fabrication of ensemble NWs for optoelectronic device applications.

Structural, microstructural and electrical characterization of BaSnO3 and Ba0.90Y0.10SnO3 synthesized by solution combustion method

NASA Astrophysics Data System (ADS)

Kumar, Upendra; Yadav, Dharmendra; Upadhyay, Shail; Thakur, Anukul K.

2018-04-01

Powder of perovskite oxides BaSnO3 and Ba0.90Y0.10SnO3 have been synthesized by solution combustion method. Rietveld profile analysis shows that the phases crystallize with cubic unit cell in the space group pm3m. Further purity of the synthesized powders was checked by Fourier transform of infrared (FTIR) spectroscopy. The average grain size of the sintered samples was obtained using Scanning electron microscopy (SEM) and found to be 4.9 and 2.8 1m for BaSnO3 and Ba0.90Y0.10SnO3, respectively. The AC conductivity (σac) of synthesized samples was measured in the frequency range from 24Hz-1MHz and temperature range 100 - 600°C. Conductivity spectra of both the samples followed universal Johnscher's power law at different temperatures. The value of bulk or dc conductivity (σdc) at different temperatures has been extracted by fitting the Johnscher's power law to AC conductivity spectra. The activation energy for σc has been obtained from the least square linear fit of data points and found to be 0.53 eV and 0.43 eV, respectively for BaSnO3 and Ba0.90Y0.10SnO3. Based on the value of activation energy it is proposed that conduction in these samples is govern via hopping of (OH)•. The value of conductivity at temperature 550°C of Ba0.90Y0.10SnO3 is 0.00406 S-cm-1 higher than BaSnO3 (0.00173 S-cm-1) at the same temperature.

Pentaatomic planar tetracoordinate silicon with 14 valence electrons: a large-scale global search of SiX(n)Y(m)(q) (n + m = 4; q = 0, ±1, -2; X, Y = main group elements from H to Br).

PubMed

Xu, Jing; Ding, Yi-hong

2015-03-05

Designing and characterizing the compounds with exotic structures and bonding that seemingly contrast the traditional chemical rules are a never-ending goal. Although the silicon chemistry is dominated by the tetrahedral picture, many examples with the planar tetracoordinate-Si skeletons have been discovered, among which simple species usually contain the 17/18 valence electrons. In this work, we report hitherto the most extensive structural search for the pentaatomic ptSi with 14 valence electrons, that is, SiXnYm(q) (n + m = 4; q = 0, ±1, -2; X, Y = main group elements from H to Br). For 129 studied systems, 50 systems have the ptSi structure as the local minimum. Promisingly, nine systems, that is, Li3SiAs(2-), HSiY3 (Y = Al/Ga), Ca3SiAl(-), Mg4Si(2-), C2LiSi, Si3Y2 (Y = Li/Na/K), each have the global minimum ptSi. The former six systems represent the first prediction. Interestingly, in HSiY3 (Y = Al/Ga), the H-atom is only bonded to the ptSi-center via a localized 2c-2e σ bond. This sharply contradicts the known pentaatomic planar-centered systems, in which the ligands are actively involved in the ligand-ligand bonding besides being bonded to the planar center. Therefore, we proposed here that to generalize the 14e-ptSi, two strategies can be applied as (1) introducing the alkaline/alkaline-earth elements and (2) breaking the peripheral bonding. In light of the very limited global ptSi examples, the presently designed six systems with 14e are expected to enrich the exotic ptSi chemistry and welcome future laboratory confirmation. © 2014 Wiley Periodicals, Inc.

Localized internal radiotherapy with 90Y particles embedded in a new thermosetting alginate gel: a feasibility study in pigs.

PubMed

Holte, Oyvind; Skretting, Arne; Bach-Gansmo, Tore; Hol, Per Kristian; Johnsrud, Kjersti; Tønnesen, Hanne Hjorth; Karlsen, Jan

2006-02-01

Internal radiotherapy requires the localization of the radionuclide to the site of action. A new injectable alginate gel formulation intended to undergo immediate gelation in tissues and capable of encapsulating radioactive particles containing 90Y was investigated. The formulation was injected intramuscularly, into the bone marrow compartment of the femur and intravenously, respectively, in pigs. The distribution of radioactivity in various tissues was determined. Following intramuscular injection, more than 90% of the radioactivity was found at the site of injection. Following injection into bone marrow, 30-40% of the radioactivity was retained at the site of injection, but a considerable amount of radioactivity was also detected in the lungs (35-45%) and the liver (5-18%). Following intravenous injection, 80-90% of the radioactivity was found in the lungs. The present formulation appears suitable for localized radiotherapy in organs and tissues having low perfusion.

Technical note: The calibration of {sup 90}Y-labeled SIR-Spheresusing a nondestructive spectroscopic assay

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

Selwyn, R.; Micka, J.; DeWerd, L.

2008-04-15

{sup 90}Y-labeled SIR-Spheres are currently used to treat patients with hepatic metastases secondary to colorectal adenocarcinoma. In general, the prescribed activity is based on empirical data collected during clinical trials. The activity of the source vial is labeled by the manufacturer as 3.0 GBq{+-}10% and is not independently verified by the end user. This technical note shows that the results of a nondestructive spectroscopic assay of a SIR-Spheressample was 26% higher than the activity stated by the manufacturer. This difference should not impact the current empirical prescription method but may be problematic for patient-specific dosimetry applications, such as image-based dosimetry.

Non-planar microfabricated gas chromatography column

DOEpatents

Lewis, Patrick R.; Wheeler, David R.

2007-09-25

A non-planar microfabricated gas chromatography column comprises a planar substrate having a plurality of through holes, a top lid and a bottom lid bonded to opposite surfaces of the planar substrate, and inlet and outlet ports for injection of a sample gas and elution of separated analytes. A plurality of such planar substrates can be aligned and stacked to provide a longer column length having a small footprint. Furthermore, two or more separate channels can enable multi-channel or multi-dimensional gas chromatography. The through holes preferably have a circular cross section and can be coated with a stationary phase material or packed with a porous packing material. Importantly, uniform stationary phase coatings can be obtained and band broadening can be minimized with the circular channels. A heating or cooling element can be disposed on at least one of the lids to enable temperature programming of the column.

Improving membrane based multiplex immunoassays for semi-quantitative detection of multiple cytokines in a single sample

PubMed Central

2014-01-01

Background Inflammatory mediators can serve as biomarkers for the monitoring of the disease progression or prognosis in many conditions. In the present study we introduce an adaptation of a membrane-based technique in which the level of up to 40 cytokines and chemokines can be determined in both human and rodent blood in a semi-quantitative way. The planar assay was modified using the LI-COR (R) detection system (fluorescence based) rather than chemiluminescence and semi-quantitative outcomes were achieved by normalizing the outcomes using the automated exposure settings of the Odyssey readout device. The results were compared to the gold standard assay, namely ELISA. Results The improved planar assay allowed the detection of a considerably higher number of analytes (n = 30 and n = 5 for fluorescent and chemiluminescent detection, respectively). The improved planar method showed high sensitivity up to 17 pg/ml and a linear correlation of the normalized fluorescence intensity with the results from the ELISA (r = 0.91). Conclusions The results show that the membrane-based technique is a semi-quantitative assay that correlates satisfactorily to the gold standard when enhanced by the use of fluorescence and subsequent semi-quantitative analysis. This promising technique can be used to investigate inflammatory profiles in multiple conditions, particularly in studies with constraints in sample sizes and/or budget. PMID:25022797

Yttrium-90 radioembolization as a bridge to liver transplantation: a single-institution experience.

PubMed

Tohme, Samer; Sukato, Daniel; Chen, Hui-Wei; Amesur, Nikhil; Zajko, Albert B; Humar, Abhinav; Geller, David A; Marsh, James W; Tsung, Allan

2013-11-01

To evaluate our experience with the use of yttrium-90 ((90)Y) radioembolization in maintaining potential candidacy and, in some instances, downstaging hepatocellular carcinoma (HCC) that does not meet Milan criteria for liver transplantation. A retrospective review of 20 consecutive patients with HCC who were listed to receive a liver transplant and were treated with (90)Y radioembolization as a sole modality for locoregional "bridge" therapy was performed. Demographics, radiographic and pathologic response, survival, and recurrences were examined. Twenty-two (90)Y treatments were performed in 20 patients before transplantation. Median time from first treatment to transplantation was 3.5 months. HCC in 14 patients met the Milan criteria at the time of the first (90)Y treatment, and HCC in six did not. All cases that originally met the Milan criteria remained within the criteria before transplantation, and two of six patients whose disease did not meet the criteria (33%) had their disease successfully downstaged to meet the criteria. Overall, nine patients (45%) had complete or partial radiologic response to (90)Y radioembolization according to modified Response Evaluation Criteria In Solid Tumors. Complete necrosis of tumor with no evidence of viable tumor on pathologic examination was observed in five patients (36%) whose disease met the Milan criteria. Particularly in regions with long wait list times, (90)Y treatment is effective in maintaining tumor size in potential liver transplantation candidates with HCC. In addition, it can also be considered as a downstaging therapy in select patients before transplantation. © SIR, 2013.

Experimental study of multichromatic terahertz wave propagation through planar micro-channels

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

Shin, Young-Min -Min; Northern Illinois Univ., Dekalb, IL; Fermi National Accelerator Lab.

2012-04-10

Previous theoretical and numerical studies [Y. M. Shin and L. R. Barnett, Appl. Phys. Lett. 92, 091501 (2008) and Y. M. Shin et al., Appl. Phys. Lett. 93, 221504 (2008)] have reported that a planar micro-channel with an asymmetric corrugation array supports strongly confined propagation of broadband THz plasmonic waves. The highly broad spectral response is experimentally demonstrated in the near-THz regime of 0.19-0.265 THz. Signal reflection and transmission tests on the three designed micro-channels including directional couplers resulted in a full-width-half-maximum bandwidth of ~ 50-60GHz with an insertion loss of approximately -5 dB, which is in good agreement withmore » simulation data. As a result, these micro-structures can be utilized for free electron beam and electronic/optic integrated devices« less

Liftings and stresses for planar periodic frameworks

PubMed Central

Borcea, Ciprian; Streinu, Ileana

2015-01-01

We formulate and prove a periodic analog of Maxwell’s theorem relating stressed planar frameworks and their liftings to polyhedral surfaces with spherical topology. We use our lifting theorem to prove deformation and rigidity-theoretic properties for planar periodic pseudo-triangulations, generalizing features known for their finite counterparts. These properties are then applied to questions originating in mathematical crystallography and materials science, concerning planar periodic auxetic structures and ultrarigid periodic frameworks. PMID:26973370

Analysis and design of planar and non-planar wings for induced drag minimization

NASA Technical Reports Server (NTRS)

Mortara, Karl W.; Straussfogel, Dennis M.; Maughmer, Mark D.

1992-01-01

The goal of the work reported herein is to develop and validate computational tools to be used for the design of planar and non-planar wing geometries for minimum induced drag. Because of the iterative nature of the design problem, it is important that, in addition to being sufficiently accurate for the problem at hand, these tools need to be reasonably fast and computationally efficient. Toward this end, a method of predicting induced drag in the presence of a free wake has been coupled with a panel method. The induced drag prediction technique is based on the application of the Kutta-Joukowski law at the trailing edge. Until now, the use of this method has not been fully explored and pressure integration and Trefftz-plane calculations favored. As is shown in this report, however, the Kutta-Joukowski method is able to give better results for a given amount of effort than the more commonly used techniques, particularly when relaxed wakes and non-planar wing geometries are considered. Using these methods, it is demonstrated that a reduction in induced drag can be achieved through non-planar wing geometries. It remains to determine what overall drag reductions are possible when the induced drag reduction is traded-off against increased wetted area. With the design methodology that is described herein, such trade studies can be performed in which the non-linear effects of the free wake are taken into account.

Molecular filter based planar Doppler velocimetry

NASA Astrophysics Data System (ADS)

Elliott, Gregory S.; Beutner, Thomas J.

1999-11-01

Molecular filter based diagnostics are continuing to gain popularity as a research tool for investigations in areas of aerodynamics, fluid mechanics, and combustion. This class of diagnostics has gone by many terms including Filtered Rayleigh Scattering, Doppler Global Velocimetry, and Planar Doppler Velocimetry. The majority of this article reviews recent advances in Planar Doppler Velocimetry in measuring up to three velocity components over a planar region in a flowfield. The history of the development of these techniques is given with a description of typical systems, components, and levels of uncertainty in the measurement. Current trends indicate that uncertainties on the order of 1 m/s are possible with these techniques. A comprehensive review is also given on the application of Planar Doppler Velocimetry to laboratory flows, supersonic flows, and large scale subsonic wind tunnels. The article concludes with a description of future trends, which may simplify the technique, followed by a description of techniques which allow multi-property measurements (i.e. velocity, density, temperature, and pressure) simultaneously.

An X-Y Platform for Randsight-Type Instruments.

ERIC Educational Resources Information Center

Clewett, R. W.; And Others

A hand-operated mechanical device, called an X-Y Platform because of its ability to undergo orthogonal planar motions reminiscent of X and Y coordinates, permits design simplifications and lower costs when used with RANDSIGHT-type closed circuit television to enable the partially sighted to read and write. This paper presents a detailed discussion…

Planar Cell Polarity Breaks the Symmetry of PAR Protein Distribution prior to Mitosis in Drosophila Sensory Organ Precursor Cells.

PubMed

Besson, Charlotte; Bernard, Fred; Corson, Francis; Rouault, Hervé; Reynaud, Elodie; Keder, Alyona; Mazouni, Khalil; Schweisguth, François

2015-04-20

During development, cell-fate diversity can result from the unequal segregation of fate determinants at mitosis. Polarization of the mother cell is essential for asymmetric cell division (ACD). It often involves the formation of a cortical domain containing the PAR complex proteins Par3, Par6, and atypical protein kinase C (aPKC). In the fly notum, sensory organ precursor cells (SOPs) divide asymmetrically within the plane of the epithelium and along the body axis to generate two distinct cells. Fate asymmetry depends on the asymmetric localization of the PAR complex. In the absence of planar cell polarity (PCP), SOPs divide with a random planar orientation but still asymmetrically, showing that PCP is dispensable for PAR asymmetry at mitosis. To study when and how the PAR complex localizes asymmetrically, we have used a quantitative imaging approach to measure the planar polarization of the proteins Bazooka (Baz, fly Par3), Par6, and aPKC in living pupae. By using imaging of functional GFP-tagged proteins with image processing and computational modeling, we find that Baz, Par6, and aPKC become planar polarized prior to mitosis in a manner independent of the AuroraA kinase and that PCP is required for the planar polarization of Baz, Par6, and aPKC during interphase. This indicates that a "mitosis rescue" mechanism establishes asymmetry at mitosis in PCP mutants. This study therefore identifies PCP as the initial symmetry-breaking signal for the planar polarization of PAR proteins in asymmetrically dividing SOPs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Availability of yttrium-90 from strontium-90: a nuclear medicine perspective.

PubMed

Chakravarty, Rubel; Dash, Ashutosh; Pillai, M R A

2012-12-01

Yttrium-90 (T(½) 64.1 hours, E(βmax)=2.28 MeV) is a pure β⁻ particle emitting radionuclide with well-established applications in targeted therapy. There are several advantages of ⁹⁰Y as a therapeutic radionuclide. It has a suitable physical half-life (∼64 hours) and decays to a stable daughter product ⁹⁰Zr by emission of high-energy β⁻ particles. Yttrium has a relatively simple chemistry and its suitability for forming complexes with a variety of chelating agents is well established. The ⁹⁰Sr/⁹⁰Y generator is an ideal source for the long-term continuous availability of no-carrier-added ⁹⁰Y suitable for the preparation of radiopharmaceuticals for radionuclide therapy. The parent radionuclide ⁹⁰Sr, which is a long-lived fission product, is available in large quantities from spent fuel. Several useful technologies have been developed for the preparation of ⁹⁰Sr/⁹⁰Y generators. There are several well-established radiopharmaceuticals based on monoclonal antibodies, peptides, and particulates labeled with ⁹⁰Y, that are in regular use for the treatment of some forms of primary cancers and arthritis. At present, there are no generators for the elution of ⁹⁰Y that can be set up in a hospital radiopharmacy. The radionuclide is procured from manufacturers and the radiopharmaceuticals are formulated on site. This article reviews the development of ⁹⁰Sr/⁹⁰Y generator and the development of ⁹⁰Y radiopharmaceuticals.

Recirculating planar magnetrons: simulations and experiment

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

Franzi, Matthew; Gilgenbach, Ronald; French, David

2011-07-01

The Recirculating Planar Magnetron (RPM) is a novel crossed-field device whose geometry is expected to reduce thermal load, enhance current yield as well as ease the geometric limitations in scaling to high RF frequencies as compared to the conventional cylindrical magnetrons. The RPM has two different adaptations: A. Axial B field and radial E field; B. Radial B field and axial E field. The preliminary configuration (A) to be used in experiments at the University of Michigan consists of two parallel planar sections which join on either end by cylindrical regions to form a concentric extruded ellipse. Similar to conventionalmore » magnetrons, a voltage across the AK gap in conjunction with an axial magnetic field provides the electrons with an ExB drift. The device is named RPM because the drifting electrons recirculate from one planar region to the other. The drifting electrons interact with the resonantly tuned slow wave structure on the anode causing spoke formation. These electron spokes drive a RF electric field in the cavities from which RF power may be extracted to Waveguides. The RPM may be designed in either a conventional configuration with the anode on the outside, for simplified extraction, or as an inverted magnetron with the anode at the inner conductor, for fast start-up. Currently, experiments at the Pulsed Power and Microwave Laboratory at the University of Michigan are in the setup and design phase. A conventional RPM with planar cavities is to be installed on the Michigan Electron Long Beam Accelerator (MELBA) and is anticipated to operate at -200kV, 0.2T with a beam current of 1-10 kA at 1GHz. The conventional RPM consists of 12 identical planar cavities, 6 on each planar side, with simulated quality factor of 20.« less

TEM characterization of planar defects in massively transformed TiAl alloy

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

Zhang, X.D.; Wiezorek, J.M.K.; Fraser, H.L.

1997-12-31

The microstructure of a massively transformed Ti-49at.%Al alloy has been studied by conventional transmission electron microscopy (CTEM) and high resolution TEM (HREM). A high density of planar defects, namely complex anti-phase domain boundaries (CAPDB) and thermal micro-twins (TMT) have been observed. CTEM images and diffraction patterns showed that two anti-phase related {gamma}-matrix domains were generally separated by a thin layer of a 90{degree}-domain, for which the c-axis is rotated 90{degree} over a common cube axis with respect to those of the {gamma}-matrix domains. HREM confirmed the presence of two crystallographically different types of 90{degree}-domains being associated with the CAPDB. Furthermore,more » interactions between the CAPDB and TMT have been observed. Local faceting of the generally wavy, non-crystallographic CAPDB parallel to the {l_brace}111{r_brace}-twinning planes occurred due to interaction with the TMT. The relaxation of the CAPDB onto {l_brace}111{r_brace} required diffusion which is proposed to be enhanced locally in the presence of the dislocations associated with the formation of TMT during the massive transformation.« less

Planar Poincare chart - A planar graphic representation of the state of light polarization

NASA Technical Reports Server (NTRS)

Tedjojuwono, Ken K.; Hunter, William W., Jr.; Ocheltree, Stewart L.

1989-01-01

The planar Poincare chart, which represents the complete planar equivalence of the Poincare sphere, is proposed. The four sets of basic lines are drawn on two separate charts for the generalization and convenience of reading the scale. The chart indicates the rotation of the principal axes of linear birefringent material. The relationships between parameters of the two charts are given as 2xi-2phi (orientation angle of the major axis-ellipticity angle) pair and 2alpha-delta (angle of amplitude ratio-phase difference angle) pair. The results are useful for designing and analyzing polarization properties of optical components with birefringent properties.

Hepatic Abscess After Yttrium-90 Radioembolization for Islet-Cell Tumor Hepatic Metastasis

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

Mascarenhas, Neil B., E-mail: neilmascarenhas1@gmail.co; Mulcahy, Mary F.; Lewandowski, Robert J.

2010-06-15

Infectious complications after yttrium-90 (y-90) radioembolization of hepatic tumors are rare. Most reports describe hepatic abscesses as complications of other locoregional therapies, such as transcatheter arterial embolization or chemoembolization. These usually occur in patients with a history of biliary intervention and present several weeks after treatment. We report a case of hepatic abscess formed immediately after y-90 radioembolization of a hepatic metastasis in a patient who had no history of previous biliary instrumentation.

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.

Enumeration of spanning trees in planar unclustered networks

NASA Astrophysics Data System (ADS)

Xiao, Yuzhi; Zhao, Haixing; Hu, Guona; Ma, Xiujuan

2014-07-01

Among a variety of subgraphs, spanning trees are one of the most important and fundamental categories. They are relevant to diverse aspects of networks, including reliability, transport, self-organized criticality, loop-erased random walks and so on. In this paper, we introduce a family of modular, self-similar planar networks with zero clustering. Relevant properties of this family are comparable to those networks associated with technological systems having low clustering, like power grids, some electronic circuits, the Internet and some biological systems. So, it is very significant to research on spanning trees of planar networks. However, for a large network, evaluating the relevant determinant is intractable. In this paper, we propose a fairly generic linear algorithm for counting the number of spanning trees of a planar network. Using the algorithm, we derive analytically the exact numbers of spanning trees in planar networks. Our result shows that the computational complexity is O(t) , which is better than that of the matrix tree theorem with O(m2t2) , where t is the number of steps and m is the girth of the planar network. We also obtain the entropy for the spanning trees of a given planar network. We find that the entropy of spanning trees in the studied network is small, which is in sharp contrast to the previous result for planar networks with the same average degree. We also determine an upper bound and a lower bound for the numbers of spanning trees in the family of planar networks by the algorithm. As another application of the algorithm, we give a formula for the number of spanning trees in an outerplanar network with small-world features.

MCM Polarimetric Radiometers for Planar Arrays

NASA Technical Reports Server (NTRS)

Kangaslahti, Pekka; Dawson, Douglas; Gaier, Todd

2007-01-01

A polarimetric radiometer that operates at a frequency of 40 GHz has been designed and built as a prototype of multiple identical units that could be arranged in a planar array for scientific measurements. Such an array is planned for use in studying the cosmic microwave background (CMB). All of the subsystems and components of this polarimetric radiometer are integrated into a single multi-chip module (MCM) of substantially planar geometry. In comparison with traditional designs of polarimetric radiometers, the MCM design is expected to greatly reduce the cost per unit in an array of many such units. The design of the unit is dictated partly by a requirement, in the planned CMB application, to measure the Stokes parameters I, Q, and U of the CMB radiation with high sensitivity. (A complete definition of the Stokes parameters would exceed the scope of this article. In necessarily oversimplified terms, I is a measure of total intensity of radiation, while Q and U are measures of the relationships between the horizontally and vertically polarized components of radiation.) Because the sensitivity of a single polarimeter cannot be increased significantly, the only way to satisfy the high-sensitivity requirement is to make a large array of polarimeters that operate in parallel. The MCM includes contact pins that can be plugged into receptacles on a standard printed-circuit board (PCB). All of the required microwave functionality is implemented within the MCM; any required supporting non-microwave ("back-end") electronic functionality, including the provision of DC bias and control signals, can be implemented by standard PCB techniques. On the way from a microwave antenna to the MCM, the incoming microwave signal passes through an orthomode transducer (OMT), which splits the radiation into an h + i(nu) beam and an h - i(nu) beam (where, using complex-number notation, h denotes the horizontal component, nu denotes the vertical component, and +/-i denotes a +/-90deg phase

Radioligand Therapy of Prostate Cancer with a Long-Lasting Prostate-Specific Membrane Antigen Targeting Agent 90Y-DOTA-EB-MCG.

PubMed

Wang, Zhantong; Jacobson, Orit; Tian, Rui; Mease, Ronnie C; Kiesewetter, Dale O; Niu, Gang; Pomper, Martin G; Chen, Xiaoyuan

2018-06-15

Several radioligands targeting prostate-specific membrane antigen (PSMA) have been clinically introduced as a new class of radiotheranostics for the treatment of prostate cancer. Among them, ((( R)-1-carboxy-2-mcercaptoethyl)carbamoyl)-l-glutamic acid (MCG) has been successfully labeled with radioisotopes for prostate cancer imaging. The aim of this study is to conjugate MCG with an albumin binding moiety to further improve the in vivo pharmacokinetics. MCG was conjugated with an Evans blue (EB) derivative for albumin binding and a DOTA chelator. PSMA positive (PC3-PIP) and PSMA negative (PC3) cells were used for both in vitro and in vivo studies. Longitudinal PET imaging was performed at 1, 4, 24, and 48 h post-injection to evaluate the biodistribution and tumor uptake of 86 Y-DOTA-EB-MCG. DOTA-EB-MCG was also labeled with 90 Y for radionuclide therapy. Besides tumor growth measurement, tumor response to escalating therapeutic doses were also evaluated by immunohistochemistry and fluorescence microscopy. Based on quantification from 86 Y-DOTA-EB-MCG PET images, the tracer uptake in PC3-PIP tumors increased from 22.33 ± 2.39%ID/g at 1 h post-injection (p.i.), to the peak of 40.40 ± 4.79%ID/g at 24 h p.i. Administration of 7.4 MBq of 90 Y-DOTA-EB-MCG resulted in significant regression of tumor growth in PSMA positive xenografts. No apparent toxicity or body weight loss was observed in all treated mice. Modification of MCG with an Evans blue derivative resulted in a highly efficient prostate cancer targeting agent (EB-MCG), which showed great potential in prostate cancer treatment after being labeled with therapeutic radioisotopes.

Motor Events during Healthy Sleep: A Quantitative Polysomnographic Study

PubMed Central

Frauscher, Birgit; Gabelia, David; Mitterling, Thomas; Biermayr, Marlene; Bregler, Deborah; Ehrmann, Laura; Ulmer, Hanno; Högl, Birgit

2014-01-01

Study Objectives: Many sleep disorders are characterized by increased motor activity during sleep. In contrast, studies on motor activity during physiological sleep are largely lacking. We quantitatively investigated a large range of motor phenomena during polysomnography in physiological sleep. Design: Prospective polysomnographic investigation. Setting: Academic referral sleep laboratory. Participants: One hundred healthy sleepers age 19-77 y were strictly selected from a representative population sample by a two-step screening procedure. Interventions: N/A. Measurements and Results: Polysomnography according to American Academy of Sleep Medicine (AASM) standards was performed, and quantitative normative values were established for periodic limb movements in sleep (PLMS), high frequency leg movements (HFLM), fragmentary myoclonus (FM), neck myoclonus (NM), and rapid eye movement (REM)-related electromyographic (EMG) activity. Thirty-six subjects had a PLMS index > 5/h, 18 had a PLMS index > 15/h (90th percentile: 24.8/h). Thirty-three subjects had HFLM (90th percentile: four sequences/night). All subjects had FM (90th percentile 143.7/h sleep). Nine subjects fulfilled AASM criteria for excessive FM. Thirty-five subjects had NM (90th percentile: 8.8/h REM sleep). For REM sleep, different EMG activity measures for the mentalis and flexor digitorum superficialis muscles were calculated: the 90th percentile for phasic mentalis EMG activity for 30-sec epochs according to AASM recommendation was 15.6%, and for tonic mentalis EMG activity 2.6%. Twenty-five subjects exceeded the recently proposed phasic mentalis cutoff of 11%. None of the subjects exceeded the tonic mentalis cutoff of 9.6%. Conclusion: Quantification of motor phenomena is a basic prerequisite to develop normative values, and is a first step toward a more precise description of the various motor phenomena present during sleep. Because rates of motor events were unexpectedly high even in physiological

Carcinoid crisis induced by receptor radionuclide therapy with 90Y-DOTATOC in a case of liver metastases from bronchial neuroendocrine tumor (atypical carcinoid).

PubMed

Davì, M V; Bodei, L; Francia, G; Bartolomei, M; Oliani, C; Scilanga, L; Reghellin, D; Falconi, M; Paganelli, G; Lo Cascio, V; Ferdeghini, M

2006-06-01

SS receptors are overexpressed in many tumors, mainly of neuroendocrine origin, thus enabling the treatment with SS analogs. The clinical experience of receptor radionuclide therapy with the new analog [90Y-DOTA0-Tyr3 ]-octreotide [90Y-DOTATOC] has been developed over the last decade and is gaining a pivotal role in the therapeutic workout of these tumors. It is well known that some procedures performed in diagnostic and therapeutic management of endocrine tumors, such as agobiopsy and hepatic chemoembolization, can be associated with the occurrence of symptoms related to the release of vasoactive amines and/or hormonal peptides from tumor cell lysis. This is the first report of a severe carcinoid crisis developed after receptor radionuclide therapy with 90Y-DOTATOC administered in a patient affected by liver metastases from bronchial neuroendocrine tumor (atypical carcinoid). Despite protection with H1 receptor antagonists, octreotide and corticosteroids, few days after the therapy the patient complained of persistent flushing of the face and upper trunk, severe labial and periocular oedema, diarrhoea and loss of appetite. These symptoms increased and required new hospitalisation. The patient received iv infusion of octreotide associated with H1 and H2 receptor antagonists and corticosteroid therapy, which induced symptom remission within few days. The case here reported confirms that radionuclide therapy is highly effective in determining early rupture of metastatic tissue and also suggests that pre-medication should be implemented before the radiopeptide administration associated with a close monitoring of the patient in the following days.

Atomic-scale identification of novel planar defect phases in heteroepitaxial YBa2Cu3O7-δ thin films

NASA Astrophysics Data System (ADS)

Gauquelin, Nicolas; Zhang, Hao; Zhu, Guozhen; Wei, John Y. T.; Botton, Gianluigi A.

2018-05-01

We have discovered two novel types of planar defects that appear in heteroepitaxial YBa2Cu3O7-δ (YBCO123) thin films, grown by pulsed-laser deposition (PLD) either with or without a La2/3Ca1/3MnO3 (LCMO) overlayer, using the combination of high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) imaging and electron energy loss spectroscopy (EELS) mapping for unambiguous identification. These planar lattice defects are based on the intergrowth of either a BaO plane between two CuO chains or multiple Y-O layers between two CuO2 planes, resulting in non-stoichiometric layer sequences that could directly impact the high-Tc superconductivity.

A methodology for efficiency optimization of betavoltaic cell design using an isotropic planar source having an energy dependent beta particle distribution.

PubMed

Theirrattanakul, Sirichai; Prelas, Mark

2017-09-01

Nuclear batteries based on silicon carbide betavoltaic cells have been studied extensively in the literature. This paper describes an analysis of design parameters, which can be applied to a variety of materials, but is specific to silicon carbide. In order to optimize the interface between a beta source and silicon carbide p-n junction, it is important to account for the specific isotope, angular distribution of the beta particles from the source, the energy distribution of the source as well as the geometrical aspects of the interface between the source and the transducer. In this work, both the angular distribution and energy distribution of the beta particles are modeled using a thin planar beta source (e.g., H-3, Ni-63, S-35, Pm-147, Sr-90, and Y-90) with GEANT4. Previous studies of betavoltaics with various source isotopes have shown that Monte Carlo based codes such as MCNPX, GEANT4 and Penelope generate similar results. GEANT4 is chosen because it has important strengths for the treatment of electron energies below one keV and it is widely available. The model demonstrates the effects of angular distribution, the maximum energy of the beta particle and energy distribution of the beta source on the betavoltaic and it is useful in determining the spatial profile of the power deposition in the cell. Copyright © 2017. Published by Elsevier Ltd.

Technical errors in planar bone scanning.

PubMed

Naddaf, Sleiman Y; Collier, B David; Elgazzar, Abdelhamid H; Khalil, Magdy M

2004-09-01

Optimal technique for planar bone scanning improves image quality, which in turn improves diagnostic efficacy. Because planar bone scanning is one of the most frequently performed nuclear medicine examinations, maintaining high standards for this examination is a daily concern for most nuclear medicine departments. Although some problems such as patient motion are frequently encountered, the degraded images produced by many other deviations from optimal technique are rarely seen in clinical practice and therefore may be difficult to recognize. The objectives of this article are to list optimal techniques for 3-phase and whole-body bone scanning, to describe and illustrate a selection of deviations from these optimal techniques for planar bone scanning, and to explain how to minimize or avoid such technical errors.

Preoperative Y-90 microsphere selective internal radiation treatment for tumor downsizing and future liver remnant recruitment: a novel approach to improving the safety of major hepatic resections.

PubMed

Gulec, Seza A; Pennington, Kenneth; Hall, Michael; Fong, Yuman

2009-01-08

Extended liver resections are being performed more liberally than ever. The extent of resection of liver metastases, however, is restricted by the volume of the future liver remnant (FLR). An intervention that would both accomplish tumor control and induce compensatory hypertrophy, with good patient tolerability, could improve clinical outcomes. A 53-year-old woman with a history of cervical cancer presented with a large liver mass. Subsequent biopsy indicated poorly differentiated carcinoma with necrosis suggestive of squamous cell origin. A decision was made to proceed with pre-operative chemotherapy and Y-90 microsphere SIRT with the intent to obtain systemic control over the disease, downsize the hepatic lesion, and improve the FLR. A surgical exploration was performed six months after the first SIRT (three months after the second). There was no extrahepatic disease. The tumor was found to be significantly decreased in size with central and peripheral scarring. The left lobe was satisfactorily hypertrophied. A formal right hepatic lobectomy was performed with macroscopic negative margins. Selective internal radiation treatment (SIRT) with yttrium-90 (Y-90) microspheres has emerged as an effective liver-directed therapy with a favorable therapeutic ratio. We present this case report to suggest that the portal vein radiation dose can be substantially increased with the intent of inducing portal/periportal fibrosis. Such a therapeutic manipulation in lobar Y-90 microsphere treatment could accomplish the end points of PVE with avoidance of the concern regarding tumor progression.

Histological Comparison of Kidney Tissue Following Radioembolization with Yttrium-90 Resin Microspheres and Embolization with Bland Microspheres

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

Silva, Suresh de, E-mail: suresh.desilva@unsw.edu.au; Mackie, Simon; Aslan, Peter

BackgroundIntra-arterial brachytherapy with yttrium-90 ({sup 90}Y) resin microspheres (radioembolization) is a procedure to selectively deliver high-dose radiation to tumors. The purpose of this research was to compare the radioembolic effect of {sup 90}Y-radioembolization versus the embolic effect of bland microspheres in the porcine kidney model.MethodsIn each of six pigs, ~25–33 % of the kidney volume was embolized with {sup 90}Y resin microspheres and an equivalent number of bland microspheres in the contralateral kidney. Kidney volume was estimated visually from contrast-enhanced fluoroscopy imaging. Morphologic and histologic analysis was performed 8–9 weeks after the procedure to assess the locations of the microspheres and extentmore » of tissue necrosis from {sup 90}Y-radioembolization and bland embolization. A semi-quantified evaluation of the non-acute peri-particle and perivascular tissue reaction was conducted. All guidelines for the care and use of animals were followed.ResultsKidneys embolized with {sup 90}Y-radioembolization decreased in mass by 30–70 % versus the contralateral kidney embolized with bland microspheres. These kidneys showed significant necrosis/fibrosis, avascularization, and glomerular atrophy in the immediate vicinity of the {sup 90}Y resin microspheres. By contrast, glomerular changes were not observed, even with clusters of bland microspheres in afferent arterioles. Evidence of a foreign body reaction was recorded in some kidneys with bland microspheres, and subcapsular scarring/infarction only with the highest load (4.96 × 10{sup 6}) of bland microspheres.ConclusionThis study showed that radioembolization with {sup 90}Y resin microspheres produces localized necrosis/fibrosis and loss of kidney mass in a porcine kidney model. This result supports the study of {sup 90}Y resin microspheres for the localized treatment of kidney tumors.« less

Contact-free trans-pars-planar illumination enables snapshot fundus camera for nonmydriatic wide field photography.

PubMed

Wang, Benquan; Toslak, Devrim; Alam, Minhaj Nur; Chan, R V Paul; Yao, Xincheng

2018-06-08

In conventional fundus photography, trans-pupillary illumination delivers illuminating light to the interior of the eye through the peripheral area of the pupil, and only the central part of the pupil can be used for collecting imaging light. Therefore, the field of view of conventional fundus cameras is limited, and pupil dilation is required for evaluating the retinal periphery which is frequently affected by diabetic retinopathy (DR), retinopathy of prematurity (ROP), and other chorioretinal conditions. We report here a nonmydriatic wide field fundus camera employing trans-pars-planar illumination which delivers illuminating light through the pars plana, an area outside of the pupil. Trans-pars-planar illumination frees the entire pupil for imaging purpose only, and thus wide field fundus photography can be readily achieved with less pupil dilation. For proof-of-concept testing, using all off-the-shelf components a prototype instrument that can achieve 90° fundus view coverage in single-shot fundus images, without the need of pharmacologic pupil dilation was demonstrated.

Overexpression of GmHsp90s, a Heat Shock Protein 90 (Hsp90) Gene Family Cloning from Soybean, Decrease Damage of Abiotic Stresses in Arabidopsis thaliana

PubMed Central

Xue, Dong; Zhao, Jinming; Gai, Junyi; Guo, Na; Xing, Han

2013-01-01

Hsp90 is one of the most conserved and abundant molecular chaperones and is an essential component of the protective stress response; however, its roles in abiotic stress responses in soybean (Glycine max) remain obscure. Here, 12 GmHsp90 genes from soybean were identified and found to be expressed and to function differentially under abiotic stresses. The 12 GmHsp90 genes were isolated and named GmHsp90A1–GmHsp90A6, GmHsp90B1, GmHsp90B2, GmHsp90C1.1, GmHsp90C1.2, GmHsp90C2.1 and GmHsp90C2.2 based on their characteristics and high homology to other Hsp90s according to a new nomenclature system. Quantitative real-time PCR expression data revealed that all the genes exhibited higher transcript levels in leaves and could be strongly induced under heat, osmotic and salt stress but not cold stress. Overexpression of five typical genes (GmHsp90A2, GmHsp90A4, GmHsp90B1, GmHsp90C1.1 and GmHsp90C2.1) in Arabidopsis thaliana provided useful evidences that GmHsp90 genes can decrease damage of abiotic stresses. In addition, an abnormal accumulation of proline was detected in some transgenic Arabidopsis plants suggested overexpressing GmHsp90s may affect the synthesis and response system of proline. Our work represents a systematic determination of soybean genes encoding Hsp90s, and provides useful evidence that GmHsp90 genes function differently in response to abiotic stresses and may affect the synthesis and response system of proline. PMID:23936107

Rapid method to determine 89Sr/ 90Sr in large concrete samples

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

Maxwell, Sherrod L.; Culligan, Brian; Hutchison, Jay B.

Here, a new rapid method has been developed that provides high quality low-level measurements of 89,90Sr in concrete samples with an MDA (Minimum Detectable Activity) of <1 mBq g -1. The new method is fast, meets new decommissioning regulatory limits and is robust even if refractory particles are present. The method utilizes a rapid fusion to ensure total dissolution of samples and rapid preconcentration and separation of 89,90Sr from 5-10 g concrete samples. When, the 89Sr/ 90Sr ratio is high, Sr can be isolated from up to 5g concrete samples, total 89/90Sr measured, and then 90Sr determined via 90Y separatedmore » after a period of ingrowth. Another approach allows the immediate determination of 90Sr in 10 g concrete aliquots without waiting for 90Y ingrowth, in instances where the shorter lived 89Sr is unlikely to be encountered.« less

Rapid method to determine 89Sr/ 90Sr in large concrete samples

DOE PAGES

Maxwell, Sherrod L.; Culligan, Brian; Hutchison, Jay B.; ...

2016-03-24

Here, a new rapid method has been developed that provides high quality low-level measurements of 89,90Sr in concrete samples with an MDA (Minimum Detectable Activity) of <1 mBq g -1. The new method is fast, meets new decommissioning regulatory limits and is robust even if refractory particles are present. The method utilizes a rapid fusion to ensure total dissolution of samples and rapid preconcentration and separation of 89,90Sr from 5-10 g concrete samples. When, the 89Sr/ 90Sr ratio is high, Sr can be isolated from up to 5g concrete samples, total 89/90Sr measured, and then 90Sr determined via 90Y separatedmore » after a period of ingrowth. Another approach allows the immediate determination of 90Sr in 10 g concrete aliquots without waiting for 90Y ingrowth, in instances where the shorter lived 89Sr is unlikely to be encountered.« less

Synthesis of square-planar aluminum(III) complexes.

PubMed

Thompson, Emily J; Myers, Thomas W; Berben, Louise A

2014-12-15

The synthesis of two four-coordinate and square planar (SP) complexes of aluminum(III) is presented. Reaction of a phenyl-substituted bis(imino)pyridine ligand that is reduced by two electrons, Na2((Ph)I2P(2-)), with AlCl3 afforded five-coordinate [((Ph)I2P(2-))Al(THF)Cl] (1). Square-planar [((Ph)I2P(2-))AlCl] (2) was obtained by performing the same reaction in diethyl ether followed by lyphilization of 2 from benzene. The four-coordinate geometry index for 2, τ4, is 0.22, where 0 would be a perfectly square-planar molecule. The analogous aluminum hydride complex, [((Ph)I2P(2-))AlH] (3), is also square-planar, and was characterized crystallographically and has τ4=0.13. Both 2 and 3 are Lewis acidic and bind 2,6-lutidine. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Strengthening the HIV Care Continuum in the Dominican Republic: Application of a Triadic Implementation Framework to Meet the UNAIDS 90-90-90 Treatment Goal.

PubMed

Bowman, Alex S; Mehta, Mili; Lerebours Nadal, Leonel; Halpern, Mina; Nicholas, Stephen W; Amesty, Silvia

2017-10-01

Innovative empirical frameworks to evaluate progress in efforts addressing HIV treatment and prevention barriers in resource-limited areas are sorely needed to achieve the UNAIDS 90-90-90 goal (90% diagnosed, 90% on treatment, and 90% virally suppressed). A triadic implementation framework (TIF) is a comprehensive conceptual tool for (1) monitoring attrition, (2) evaluating operational programs, and (3) measuring the impact of specific implementation goals within the care continuum. TIF will assess the effects of enhanced programs on adherence and virologic suppression within the HIV care continuum at a regional clinic in the Dominican Republic (Clínica de Familia La Romana [CFLR]) and its program serving high-risk, migratory batey (sugarcane cultivation) communities. A retrospective cohort study completed during 2015 collected deidentified data from a CFLR chart review of adult HIV patients diagnosed in 2013. The results were quantitatively analyzed and compared to 2011 cohort data. In 2013, 310 patients were diagnosed HIV positive. The results demonstrated 73% enrolling in care, 28% adhering to care, and 16% achieving viral load suppression. Engagement increased across all steps of the care continuum compared to a 2011 cohort, culminating in a significant increase in undetectable viral load from 4% to 16% (p < 0.001). The batey program showed significant increases in patient enrollment compared to the 2011 cohort (p < 0.001). Meeting the UNAIDS 90-90-90 goal requires enhanced services in high-burden, resource-limited regions. CFLR employs TIF to assess progress and programmatic areas in need of strengthening. Data suggest enhanced CFLR services improve outcomes. Given improvements, maintenance and expansion of similar programs are warranted to achieve the 90-90-90 goal.

Stress measurements of planar dielectric elastomer actuators

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

Osmani, Bekim; Aeby, Elise A.; Müller, Bert

Dielectric elastomer actuator (DEA) micro- and nano-structures are referred to artificial muscles because of their specific continuous power and adequate time response. The bending measurement of an asymmetric, planar DEA is described. The asymmetric cantilevers consist of 1 or 5 μm-thin DEAs deposited on polyethylene naphthalate (PEN) substrates 16, 25, 38, or 50 μm thick. The application of a voltage to the DEA electrodes generates an electrostatic pressure in the sandwiched silicone elastomer layer, which causes the underlying PEN substrate to bend. Optical beam deflection enables the detection of the bending angle vs. applied voltage. Bending radii as large asmore » 850 m were reproducibly detected. DEA tests with electric fields of up to 80 V/μm showed limitations in electrode’s conductivity and structure failures. The actuation measurement is essential for the quantitative characterization of nanometer-thin, low-voltage, single- and multi-layer DEAs, as foreseen for artificial sphincters to efficiently treat severe urinary and fecal incontinence.« less

Evaluation of Beta-Absorbed Fractions in a Mouse Model for 90Y, 188Re, 166Ho, 149Pm, 64Cu, and 177Lu Radionuclides

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

Miller, William H.; Hartmann-Siantar, Christine; Fisher, Darrell R.

2005-08-01

Several short-lived, high-energy beta emitters are being proposed as the radionuclide components for molecular-targeted potential cancer therapeutic agents. The laboratory mice used to determine the efficacy of these new agents have organs that are relatively small compared to the ranges of these high-energy particles. The dosimetry model developed by Hui et al. was extended to provide realistic beta-dose estimates for organs in mice that received therapeutic radiopharmaceuticals containing 90Y, 188Re, 166Ho, 149Pm, 64Cu, and 177 Lu. Major organs in this model included the liver, spleen, kidneys, lungs, heart, stomach, small and large bowel, thyroid, pancreas, bone, marrow, carcass, and amore » 0.025-g tumor. The study as reported in this paper verifies their results for 90Y and extends them by using their organ geometry factors combined with newly calculated organ self-absorbed fractions from PEREGRINE and MCNP. PEREGRINE and MCNP agree to within 8% for the worst-case organ with average differences (averaged over all organs) decreasing from 5% for 90Y to 1% for 177Lu. When used with typical biodistribution data, the three different models predict doses that are in agreement to within 5% for the worst-case organ. The beta-absorbed fractions and cross-organ-deposited energy provided in this paper can be used by researchers to predict mouse-organ doses and should contribute to an improved understanding of the relationship between dose and radiation toxicity in mouse models where use of these isotopes is favorable.« less

Strontium-90 in newborns and childhood disease.

PubMed

Mangano, J J; Sternglass, E J; Gould, J M; Sherman, J D; Brown, J; McDonnell, W

2000-01-01

Radioactive strontium-90 concentrations in baby teeth obtained from Suffolk County, New York, rose steadily during the 1980s. Recent levels of strontium-90 are similar to those reported for babies born in the late 1950s-at the height of atmospheric nuclear weapons testing in Nevada. Strontium-90 concentrations increased concomitantly with increases in cancer incidence among Suffolk children under the age of 5 y, a result that mimicked parallel trends observed in the 1950s and early 1960s. Given that effects of strontium-90 on developing cells are most pronounced during the fetal and infant periods, escalating levels should be viewed as a factor in the recent decline in various child health status measures.

Complete eradication of hepatic metastasis from colorectal cancer by Yttrium-90 SIRT

PubMed Central

Garrean, Sean; Muhs, Amanda; Bui, James T; Blend, Michael J; Owens, Charles; Helton, William S; Espat, N Joseph

2007-01-01

Yttrium-90 (Y-90) radioembolization, also known as selective internal radiation therapy (SIRT), is a regional hepatic therapy used in the treatment of unresectable colorectal cancer (CRC) liver metastases. In SIRT, Y-90 impregnated microspheres are injected into the VASCULAR SUPPLY of hepatic tumor, leading to selective irradiation and necrosis of tumor TISSUE. While several studies demonstrate improved local control and survival with SIRT, the specific indications for this therapy have yet to be defined. Typically, SIRT is given in combination with chemotherapy as multimodal treatment for unresectable hepatic CRC. However, it HAS ALSO FOUND INCREASING USE as a salvage therapy in chemo-refractory patients. Herein, the authors describe their experience with SIRT as “stand alone” therapy in a surgically-prohibitive, chemotherapy naive patient with hepatic CRC metastasis. The results suggest that Y-90 SIRT may have potential applications beyond its usual role as a palliative or salvage therapy for unresectable hepatic CRC. PMID:17589957

Analysis of radioactive strontium-90 in food by Čerenkov liquid scintillation counting.

PubMed

Pan, Jingjing; Emanuele, Kathryn; Maher, Eileen; Lin, Zhichao; Healey, Stephanie; Regan, Patrick

2017-08-01

A simple liquid scintillation counting method using DGA/TRU resins for removal of matrix/radiometric interferences, Čerenkov counting for measuring 90 Y, and EDXRF for quantifying Y recovery was validated for analyzing 90 Sr in various foods. Analysis of samples containing energetic β emitters required using TRU resin to avoid false detection and positive bias. Additional 34% increase in Y recovery was obtained by stirring the resin while eluting Y with H 2 C 2 O 4 . The method showed acceptable accuracy (±10%), precision (10%), and detectability (~0.09Bqkg -1 ). Published by Elsevier Ltd.

A Planar Two-Dimensional Superconducting Bolometer Array for the Green Bank Telescope

NASA Technical Reports Server (NTRS)

Benford, Dominic; Staguhn, Johannes G.; Chervenak, James A.; Chen, Tina C.; Moseley, S. Harvey; Wollack, Edward J.; Devlin, Mark J.; Dicker, Simon R.; Supanich, Mark

2004-01-01

In order to provide high sensitivity rapid imaging at 3.3mm (90GHz) for the Green Bank Telescope - the world's largest steerable aperture - a camera is being built by the University of Pennsylvania, NASA/GSFC, and NRAO. The heart of this camera is an 8x8 close-packed, Nyquist-sampled detector array. We have designed and are fabricating a functional superconducting bolometer array system using a monolithic planar architecture. Read out by SQUID multiplexers, the superconducting transition edge sensors will provide fast, linear, sensitive response for high performance imaging. This will provide the first ever superconducting bolometer array on a facility instrument.

A planar reacting shear layer system for the study of fluid dynamics-combustion interaction

NASA Technical Reports Server (NTRS)

Marek, C. J.; Chang, C. T.; Ghorashi, B.; Wey, C. C.; Wey, C.; Mularz, E. J.

1989-01-01

A versatile planar reacting shear layer facility is constructed at NASA-Lewis. The research objectives, as well as design, instrumentations and the operational procedures developed for the system are described. The fundamental governing equations and the type of quantitative information that are needed from experiments are described. Additionally, a review of earlier work is presented. Whenever appropriate, comparisons are made with similar systems in other facilities and the main differences are described. Finally, the nonintrusive measurement techniques (PLIF, PMS, LDV, and Schlieren photography) and the type of experiments that are planned are described.

Quantitative mapping of total choline in healthy human breast using proton echo planar spectroscopic imaging (PEPSI) at 3 Tesla.

PubMed

Zhao, Chenguang; Bolan, Patrick J; Royce, Melanie; Lakkadi, Navneeth; Eberhardt, Steven; Sillerud, Laurel; Lee, Sang-Joon; Posse, Stefan

2012-11-01

To quantitatively measure tCho levels in healthy breasts using Proton-Echo-Planar-Spectroscopic-Imaging (PEPSI). The two-dimensional mapping of tCho at 3 Tesla across an entire breast slice using PEPSI and a hybrid spectral quantification method based on LCModel fitting and integration of tCho using the fitted spectrum were developed. This method was validated in 19 healthy females and compared with single voxel spectroscopy (SVS) and with PRESS prelocalized conventional Magnetic Resonance Spectroscopic Imaging (MRSI) using identical voxel size (8 cc) and similar scan times (∼7 min). A tCho peak with a signal to noise ratio larger than 2 was detected in 10 subjects using both PEPSI and SVS. The average tCho concentration in these subjects was 0.45 ± 0.2 mmol/kg using PEPSI and 0.48 ± 0.3 mmol/kg using SVS. Comparable results were obtained in two subjects using conventional MRSI. High lipid content in the spectra of nine tCho negative subjects was associated with spectral line broadening of more than 26 Hz, which made tCho detection impossible. Conventional MRSI with PRESS prelocalization in glandular tissue in two of these subjects yielded tCho concentrations comparable to PEPSI. The detection sensitivity of PEPSI is comparable to SVS and conventional PRESS-MRSI. PEPSI can be potentially used in the evaluation of tCho in breast cancer. A tCho threshold concentration value of ∼0.7 mmol/kg might be used to differentiate between cancerous and healthy (or benign) breast tissues based on this work and previous studies. Copyright © 2012 Wiley Periodicals, Inc.

Quantitative Mapping of Total Choline in Healthy Human Breast Using Proton Echo Planar Spectroscopic Imaging (PEPSI) at 3 Tesla

PubMed Central

Zhao, Chenguang; Bolan, Patrick J.; Royce, Melanie; Lakkadi, Navneeth; Eberhardt, Steven; Sillerud, Laurel; Lee, Sang-Joon; Posse, Stefan

2012-01-01

Purpose To quantitatively measure tCho levels in healthy breasts using Proton-Echo-Planar-Spectroscopic-Imaging (PEPSI). Material and Methods The 2-dimensional mapping of tCho at 3 Tesla across an entire breast slice using PEPSI and a hybrid spectral quantification method based on LCModel fitting and integration of tCho using the fitted spectrum were developed. This method was validated in 19 healthy females and compared with single voxel spectroscopy (SVS) and with PRESS prelocalized conventional Magnetic Resonance Spectroscopic Imaging (MRSI) using identical voxel size (8 cc) and similar scan times (~7 min). Results A tCho peak with a signal to noise ratio larger than 2 was detected in 10 subjects using both PEPSI and SVS. The average tCho concentration in these subjects was 0.45 ± 0.2 mmol/kg using PEPSI and 0.48±0.3 mmol/kg using SVS. Comparable results were obtained in 2 subjects using conventional MRSI. High lipid content in the spectra of 9 tCho negative subjects was associated with spectral line broadening of more than 26 Hz, which made tCho detection impossible. Conventional MRSI with PRESS prelocalization in glandular tissue in two of these subjects yielded tCho concentrations comparable to PEPSI. Conclusion The detection sensitivity of PEPSI is comparable to SVS and conventional PRESS-MRSI. PEPSI can be potentially used in the evaluation of tCho in breast cancer. A tCho threshold concentration value of ~0.7mmol/kg might be used to differentiate between cancerous and healthy (or benign) breast tissues based on this work and previous studies. PMID:22782667

Dielectric Covered Planar Antennas

NASA Technical Reports Server (NTRS)

Llombart Juan, Nuria (Inventor); Lee, Choonsup (Inventor); Chattopadhyay, Goutam (Inventor); Gill, John J. (Inventor); Skalare, Anders J. (Inventor); Siegel, Peter H. (Inventor)

2014-01-01

An antenna element suitable for integrated arrays at terahertz frequencies is disclosed. The antenna element comprises an extended spherical (e.g. hemispherical) semiconductor lens, e.g. silicon, antenna fed by a leaky wave waveguide feed. The extended spherical lens comprises a substantially spherical lens adjacent a substantially planar lens extension. A couple of TE/TM leaky wave modes are excited in a resonant cavity formed between a ground plane and the substantially planar lens extension by a waveguide block coupled to the ground plane. Due to these modes, the primary feed radiates inside the lens with a directive pattern that illuminates a small sector of the lens. The antenna structure is compatible with known semiconductor fabrication technology and enables production of large format imaging arrays.

Planar differential mobility spectrometer as a pre-filter for atmospheric pressure ionization mass spectrometry

PubMed Central

Schneider, Bradley B.; Covey, Thomas R.; Coy, Stephen L.; Krylov, Evgeny V.

2010-01-01

Ion filters based on planar DMS can be integrated with the inlet configuration of most mass spectrometers, and are able to enhance the quality of mass analysis and quantitative accuracy by reducing chemical noise, and by pre-separating ions of similar mass. This paper is the first in a series of three papers describing the optimization of DMS / MS instrumentation. In this paper the important physical parameters of a planar DMS-MS interface including analyzer geometry, analyzer coupling to a mass spectrometer, and transport gas flow control are considered. The goal is to optimize ion transmission and transport efficiency, provide optimal and adjustable resolution, and produce stable operation under conditions of high sample contamination. We discuss the principles of DMS separations and highlight the theoretical underpinnings. The main differences between planar and cylindrical geometries are presented, including a discussion of the advantages and disadvantages of RF ion focusing. In addition, we present a description of optimization of the frequency and amplitude of the DMS fields for resolution and ion transmission, and a discussion of the influence and importance of ion residence time in DMS. We have constructed a mass spectrometer interface for planar geometries that takes advantage of atmospheric pressure gas dynamic principles, rather than ion focusing, to minimize ion losses from diffusion in the analyzer and to maximize total ion transport into the mass spectrometer. A variety of experimental results has been obtained that illustrate the performance of this type of interface, including tests of resistance to high contamination levels, and the separation of stereoisomers. In a subsequent publication the control of the chemical interactions that drive the separation process of a DMS / MS system will be considered. In a third publication we describe novel electronics designed to provide the high voltages asymmetric waveform fields (SV) required for these

Biodistribution of Yttrium-90-Labeled Anti-CD45 Antibody in a Nonhuman Primate Model

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

Nemecek, Eneida; Hamlin, Donald K.; Fisher, Darrell R.

2005-01-15

Radioimmunotherapy may improve the outcome of hematopoietic cell transplantation for hematologic malignancies by delivering targeted radiation to hematopoietic organs while relatively sparing nontarget organs. We evaluated the organ localization of yttrium-90-labeled anti-CD45 (90Y-anti-CD45) antibody in macaques, a model that had previously predicted iodine-131-labeled anti-CD-45 (131I-anti-CD45) antibody biodistribution in humans. Experimental Design: Twelve Macaca nemestrina primates received anti-CD45 antibody labeled with 1 to 2 mCi of 90Y followed by serial blood sampling and marrow and lymph node biopsies, and necropsy. The content of 90Y per gram of tissue was determined by liquid scintillation spectrometry. Time-activity curves were constructed using average isotopemore » concentrations in each tissue at measured time points to yield the fractional residence time and estimate radiation absorbed doses for each organ per unit of administered activity. The biodistribution of 90Y-anti-CD45 antibody was then compared with that previously obtained with 131I-anti-CD45 antibody in macaques. Results: The spleen received 2,120, marrow 1,060, and lymph nodes 315 cGy/mCi of 90Y injected. The liver and lungs were the nontarget organs receiving the highest radiation absorbed doses (440 and 285 cGy/mCi, respectively). Ytrrium-90-labeled anti-CD45 antibody delivered 2.5- and 3.7-fold more radiation to marrow than to liver and lungs, respectively. The ratios previously observed with 131I-antiCD45 antibody were 2.5-and 2.2-fold more radiation to marrow than to liver and lungs, respectively. Conclusions: This study shows that 90Y-anti-CD45 antibody can deliver relatively selective radiation to hematopoietic tissues, with similar ratios of radiation delivered to target versus nontarget organs, as compared with the 131I immunoconjugate in the same animal model.« less

Planar metasurface retroreflector

NASA Astrophysics Data System (ADS)

Arbabi, Amir; Arbabi, Ehsan; Horie, Yu; Kamali, Seyedeh Mahsa; Faraon, Andrei

2017-07-01

Metasurfaces are two-dimensional arrangements of subwavelength scatterers that control the propagation of optical waves. Here, we show that cascaded metasurfaces, each performing a predefined mathematical transformation, provide a new optical design framework that enables new functionalities not yet demonstrated with single metasurfaces. Specifically, we demonstrate that retroreflection can be achieved with two vertically stacked planar metasurfaces, the first performing a spatial Fourier transform and its inverse, and the second imparting a spatially varying momentum to the Fourier transform of the incident light. Using this concept, we fabricate and test a planar monolithic near-infrared retroreflector composed of two layers of silicon nanoposts, which reflects light along its incident direction with a normal incidence efficiency of 78% and a large half-power field of view of 60°. The metasurface retroreflector demonstrates the potential of cascaded metasurfaces for implementing novel high-performance components, and enables low-power and low-weight passive optical transmitters.

Chaotic non-planar vibrations of the thin elastica. Part I: Experimental observation of planar instability

NASA Astrophysics Data System (ADS)

Cusumano, J. P.; Moon, F. C.

1995-01-01

In this two-part paper, the results of an investigation into the non-linear dynamics of a flexible cantilevered rod (the elastica) with a thin rectangular cross-section are presented. An experimental examination of the dynamics of the elastica over a broad parameter range forms the core of Part I. In Part II, the experimental work is related to a theoretical study of the mechanics of the elastica, and the study of a two-degree-of-freedom model obtained by modal projection. The experimental system used in this investigation is a rod with clamped-free boundary conditions, forced by sinusoidally displacing the clamped end. Planar periodic motions of the driven elastica are shown to lose stability at distinct resonant wedges, and the resulting motions are shown in general to be non-planar, chaotic, bending-torsion oscillations. Non-planar motions in all resonances exhibit energy cascading and dynamic two-well phenomena, and a family of asymmetric, bending-torsion non-linear modes is discovered. Correlation dimension calculations are used to estimate the number of active degrees of freedom in the system.

Patient Selection and Activity Planning Guide for Selective Internal Radiotherapy With Yttrium-90 Resin Microspheres

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

Lau, Wan-Yee, E-mail: josephlau@surgery.cuhk.edu.hk; Kennedy, Andrew S.; Department of Biomedical Engineering, North Carolina State University, Raleigh, NC

Purpose: Selective internal radiotherapy (SIRT) with yttrium-90 ({sup 90}Y) resin microspheres can improve the clinical outcomes for selected patients with inoperable liver cancer. This technique involves intra-arterial delivery of {beta}-emitting microspheres into hepatocellular carcinomas or liver metastases while sparing uninvolved structures. Its unique mode of action, including both {sup 90}Y brachytherapy and embolization of neoplastic microvasculature, necessitates activity planning methods specific to SIRT. Methods and Materials: A panel of clinicians experienced in {sup 90}Y resin microsphere SIRT was convened to integrate clinical experience with the published data to propose an activity planning pathway for radioembolization. Results: Accurate planning is essentialmore » to minimize potentially fatal sequelae such as radiation-induced liver disease while delivering tumoricidal {sup 90}Y activity. Planning methods have included empiric dosing according to degree of tumor involvement, empiric dosing adjusted for the body surface area, and partition model calculations using Medical Internal Radiation Dose principles. It has been recommended that at least two of these methods be compared when calculating the microsphere activity for each patient. Conclusions: Many factors inform {sup 90}Y resin microsphere SIRT activity planning, including the therapeutic intent, tissue and vasculature imaging, tumor and uninvolved liver characteristics, previous therapies, and localization of the microsphere infusion. The influence of each of these factors has been discussed.« less

A PET reconstruction formulation that enforces non-negativity in projection space for bias reduction in Y-90 imaging

NASA Astrophysics Data System (ADS)

Lim, Hongki; Dewaraja, Yuni K.; Fessler, Jeffrey A.

2018-02-01

Most existing PET image reconstruction methods impose a nonnegativity constraint in the image domain that is natural physically, but can lead to biased reconstructions. This bias is particularly problematic for Y-90 PET because of the low probability positron production and high random coincidence fraction. This paper investigates a new PET reconstruction formulation that enforces nonnegativity of the projections instead of the voxel values. This formulation allows some negative voxel values, thereby potentially reducing bias. Unlike the previously reported NEG-ML approach that modifies the Poisson log-likelihood to allow negative values, the new formulation retains the classical Poisson statistical model. To relax the non-negativity constraint embedded in the standard methods for PET reconstruction, we used an alternating direction method of multipliers (ADMM). Because choice of ADMM parameters can greatly influence convergence rate, we applied an automatic parameter selection method to improve the convergence speed. We investigated the methods using lung to liver slices of XCAT phantom. We simulated low true coincidence count-rates with high random fractions corresponding to the typical values from patient imaging in Y-90 microsphere radioembolization. We compared our new methods with standard reconstruction algorithms and NEG-ML and a regularized version thereof. Both our new method and NEG-ML allow more accurate quantification in all volumes of interest while yielding lower noise than the standard method. The performance of NEG-ML can degrade when its user-defined parameter is tuned poorly, while the proposed algorithm is robust to any count level without requiring parameter tuning.

Design and performance evaluation of an interferometric controlled planar nanopositioning system

NASA Astrophysics Data System (ADS)

Hesse, S.; Schäffel, C.; Mohr, H.-U.; Katzschmann, M.; Büchner, H.-J.

2012-07-01

High technology applications for example in the semiconductor or the optical industry require positioning systems providing repeatability and uncertainty in the range of nanometers together with x-, y-travel ranges of several hundreds of millimeters. We contribute in this research by investigating the applicability of integrated planar direct drives for the realization of nanopositioning- and nanomeasuring machines (NPM/NMM). The paper introduces the concept of planar integrated direct drives and explains the engineering design of the realized system for a 100 mm circular travel range in x and y. It presents the drive system parameters and the arrangement and interaction of the main components. The results of the initial operation are presented with a special focus on the question how the closed loop system can be taken into operation with a free floating slider. The evaluation of the positioning performance leads to the result that a 2D servo error of less than exy = 1.3 nm is achieved at arbitrary positions within the travel range. As a result of repeated step response tests, the positioning resolution is 0.5 nm. The measurement of the coincidental z-movement of the aerostatically supported slider yields a z-vibration with a standard deviation of σz = 0.45 nm. Regarding the drive system these results represent the limit of what can be reached with this setup as the measured error motions are in the range of the noise of the fixed environment setup. By measuring the characteristics of the aerostatic slider support at the fully assembled system the present air bearing stiffness is determined and based on a FEM-simulation of the slider eigenfrequencies the influence on the force transfer behavior is expected to be only marginal.

Treatment of conjunctival lymphomas by beta-ray brachytherapy using a strontium-90-yttrium-90 applicator.

PubMed

Regueiro, C A; Valcárcel, F J; Romero, J; de la Torre, A

2002-12-01

We reviewed the outcome of the 10 patients (13 eyes) with localized, biopsy-proven, low-grade lymphoma of the conjunctiva treated at our Department between 1988 and 1997. All patients were treated by beta-ray brachytherapy using a bidirectional 90Sr-90Y ophthalmic applicator (Applicator SIA 2, Amersham plc). Total doses, prescribed at the surface of the applicator, varied between 40 Gy and 80 Gy. With a median follow-up of 78 months (range: 14 to 146 months), seven patients remained with no evidence of relapse (67.5% 10 year disease free survival). Local control was achieved in 10 out of 13 eyes (76.9%). Two of the three local relapses were marginal. One of these three patients also developed a metachronous lymphoma in the contralateral conjunctiva. These three patients underwent a second course of brachytherapy with 90Sr/90Y and remained free of second relapse 109, 68 and 33 months after salvage therapy. No cases of systemic relapse were observed. Late (LENT-SOMA) complications were of grade 2 in five eyes, of grade 3 in one eye and of grade 4 in one eye. Late complications of grade 2 or higher were observed in one out of five patients (20%) treated with doses lower or equal to 50 Gy and in six out of eight patients (75%) treated with doses higher than 50 Gy (P=0.086). Our data indicates that beta-ray brachytherapy was ultimately able to control most conjunctival lymphomas but carried a risk of late complications and marginal relapses that was possibly higher than the rates reported for other radiotherapy techniques.

Isotropic enhancement in the critical current density of YBCO thin films incorporating nanoscale Y2BaCuO5 inclusions

NASA Astrophysics Data System (ADS)

Jha, Alok K.; Matsumoto, Kaname; Horide, Tomoya; Saini, Shrikant; Mele, Paolo; Ichinose, Ataru; Yoshida, Yutaka; Awaji, Satoshi

2017-09-01

The effect of incorporation of nanoscale Y2BaCuO5 (Y211) inclusions on the vortex pinning properties of YBa2Cu3O7-δ (YBCO or Y123) superconducting thin films is investigated in detail on the basis of variation of critical current density (JC) with applied magnetic field and also with the orientation of the applied magnetic field at two different temperatures: 77 K and 65 K. Surface modified target approach is employed to incorporate nanoscale Y211 inclusions into the superconducting YBCO matrix. The efficiency of Y211 nanoinclusions in reducing the angular anisotropy of critical current density is found to be significant. The observed angular dependence of the critical current density is discussed on the basis of mutually occupied volume by a vortex and spherical and/or planar defect. A dip in JC near the ab-plane is also observed which has been analyzed on the basis of variation of pinning potential corresponding to a spherical (3-D) or planar (2-D) pinning center and has been attributed to a reduced interaction volume of the vortices with a pinning center and competing nature of the potentials due to spherical and planar defects.

Planarization of metal films for multilevel interconnects by pulsed laser heating

DOEpatents

Tuckerman, David B.

1987-01-01

In the fabrication of multilevel integrated circuits, each metal layer is planarized by heating to momentarily melt the layer. The layer is melted by sweeping laser pulses of suitable width, typically about 1 microsecond duration, over the layer in small increments. The planarization of each metal layer eliminates irregular and discontinuous conditions between successive layers. The planarization method is particularly applicable to circuits having ground or power planes and allows for multilevel interconnects. Dielectric layers can also be planarized to produce a fully planar multilevel interconnect structure. The method is useful for the fabrication of VLSI circuits, particularly for wafer-scale integration.

Synthesis, Radiolabelling and In Vitro Characterization of the Gallium-68-, Yttrium-90- and Lutetium-177-Labelled PSMA Ligand, CHX-A''-DTPA-DUPA-Pep.

PubMed

Baur, Benjamin; Solbach, Christoph; Andreolli, Elena; Winter, Gordon; Machulla, Hans-Jürgen; Reske, Sven N

2014-04-29

Since prostate-specific membrane antigen (PSMA) has been identified as a diagnostic target for prostate cancer, many urea-based small PSMA-targeting molecules were developed. First, the clinical application of these Ga-68 labelled compounds in positron emission tomography (PET) showed their diagnostic potential. Besides, the therapy of prostate cancer is a demanding field, and the use of radiometals with PSMA bearing ligands is a valid approach. In this work, we describe the synthesis of a new PSMA ligand, CHX-A''-DTPA-DUPA-Pep, the subsequent labelling with Ga-68, Lu-177 and Y-90 and the first in vitro characterization. In cell investigations with PSMA-positive LNCaP C4-2 cells, KD values of ≤14.67 ± 1.95 nM were determined, indicating high biological activities towards PSMA. Radiosyntheses with Ga-68, Lu-177 and Y-90 were developed under mild reaction conditions (room temperature, moderate pH of 5.5 and 7.4, respectively) and resulted in nearly quantitative radiochemical yields within 5 min.

Synthesis, Radiolabelling and In Vitro Characterization of the Gallium-68-, Yttrium-90- and Lutetium-177-Labelled PSMA Ligand, CHX-A''-DTPA-DUPA-Pep

PubMed Central

Baur, Benjamin; Solbach, Christoph; Andreolli, Elena; Winter, Gordon; Machulla, Hans-Jürgen; Reske, Sven N.

2014-01-01

Since prostate-specific membrane antigen (PSMA) has been identified as a diagnostic target for prostate cancer, many urea-based small PSMA-targeting molecules were developed. First, the clinical application of these Ga-68 labelled compounds in positron emission tomography (PET) showed their diagnostic potential. Besides, the therapy of prostate cancer is a demanding field, and the use of radiometals with PSMA bearing ligands is a valid approach. In this work, we describe the synthesis of a new PSMA ligand, CHX-A''-DTPA-DUPA-Pep, the subsequent labelling with Ga-68, Lu-177 and Y-90 and the first in vitro characterization. In cell investigations with PSMA-positive LNCaP C4-2 cells, KD values of ≤14.67 ± 1.95 nM were determined, indicating high biological activities towards PSMA. Radiosyntheses with Ga-68, Lu-177 and Y-90 were developed under mild reaction conditions (room temperature, moderate pH of 5.5 and 7.4, respectively) and resulted in nearly quantitative radiochemical yields within 5 min. PMID:24787458

40 CFR 90.321 - NDIR analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) Perform a linear least-square regression on the data generated. Use an equation of the form y=mx, where x... covering at least 80 percent of the 10 to 90 range (64 percent) is required (see following table). Example...

40 CFR 90.321 - NDIR analyzer calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Perform a linear least-square regression on the data generated. Use an equation of the form y=mx, where x... covering at least 80 percent of the 10 to 90 range (64 percent) is required (see following table). Example...

40 CFR 90.321 - NDIR analyzer calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Perform a linear least-square regression on the data generated. Use an equation of the form y=mx, where x... covering at least 80 percent of the 10 to 90 range (64 percent) is required (see following table). Example...

40 CFR 90.321 - NDIR analyzer calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Perform a linear least-square regression on the data generated. Use an equation of the form y=mx, where x... covering at least 80 percent of the 10 to 90 range (64 percent) is required (see following table). Example...

Optimization of yttrium-90 PET for simultaneous PET/MR imaging: A phantom study

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

Eldib, Mootaz

2016-08-15

Purpose: Positron emission tomography (PET) imaging of yttrium-90 in the liver post radioembolization has been shown useful for personalized dosimetry calculations and evaluation of extrahepatic deposition. The purpose of this study was to quantify the benefits of several MR-based data correction approaches offered by using a combined PET/MR system to improve Y-90 PET imaging. In particular, the feasibility of motion and partial volume corrections were investigated in a controlled phantom study. Methods: The ACR phantom was filled with an initial concentration of 8 GBq of Y-90 solution resulting in a contrast of 10:1 between the hot cylinders and the background.more » Y-90 PET motion correction through motion estimates from MR navigators was evaluated by using a custom-built motion stage that simulated realistic amplitudes of respiration-induced liver motion. Finally, the feasibility of an MR-based partial volume correction method was evaluated using a wavelet decomposition approach. Results: Motion resulted in a large (∼40%) loss of contrast recovery for the 8 mm cylinder in the phantom, but was corrected for after MR-based motion correction was applied. Partial volume correction improved contrast recovery by 13% for the 8 mm cylinder. Conclusions: MR-based data correction improves Y-90 PET imaging on simultaneous PET/MR systems. Assessment of these methods must be studied further in the clinical setting.« less

Directional solidification of a planar interface in the presence of a time-dependent electric current

NASA Technical Reports Server (NTRS)

Brush, L. N.; Coriell, S. R.; Mcfadden, G. B.

1990-01-01

Directional solidification of pure materials and binary alloys with a planar crystal-metal interface in the presence of a time-dependent electric current is considered. For a variety of time-dependent currents, the temperature fields and the interface velocity as functions of time are presented for indium antimonide and bismuth and for the binary alloys germanium-gallium and tin-bismuth. For the alloys, the solid composition is calculated as a function of position. Quantitative predictions are made of the effect of an electrical pulse on the solute distribution in the solidified material.

SU-D-201-05: Phantom Study to Determine Optimal PET Reconstruction Parameters for PET/MR Imaging of Y-90 Microspheres Following Radioembolization

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

Maughan, N; Conti, M; Parikh, P

2015-06-15

Purpose: Imaging Y-90 microspheres with PET/MRI following hepatic radioembolization has the potential for predicting treatment outcome and, in turn, improving patient care. The positron decay branching ratio, however, is very small (32 ppm), yielding images with poor statistics even when therapy doses are used. Our purpose is to find PET reconstruction parameters that maximize the PET recovery coefficients and minimize noise. Methods: An initial 7.5 GBq of Y-90 chloride solution was used to fill an ACR phantom for measurements with a PET/MRI scanner (Siemens Biograph mMR). Four hot cylinders and a warm background activity volume of the phantom were filledmore » with a 10:1 ratio. Phantom attenuation maps were derived from scaled CT images of the phantom and included the MR phased array coil. The phantom was imaged at six time points between 7.5–1.0 GBq total activity over a period of eight days. PET images were reconstructed via OP-OSEM with 21 subsets and varying iteration number (1–5), post-reconstruction filter size (5–10 mm), and either absolute or relative scatter correction. Recovery coefficients, SNR, and noise were measured as well as total activity in the phantom. Results: For the 120 different reconstructions, recovery coefficients ranged from 0.1–0.6 and improved with increasing iteration number and reduced post-reconstruction filter size. SNR, however, improved substantially with lower iteration numbers and larger post-reconstruction filters. From the phantom data, we found that performing 2 iterations, 21 subsets, and applying a 5 mm Gaussian post-reconstruction filter provided optimal recovery coefficients at a moderate noise level for a wide range of activity levels. Conclusion: The choice of reconstruction parameters for Y-90 PET images greatly influences both the accuracy of measurements and image quality. We have found reconstruction parameters that provide optimal recovery coefficients with minimized noise. Future work will include the

Integrated Optics for Planar imaging and Optical Signal Processing

NASA Astrophysics Data System (ADS)

Song, Qi

Silicon photonics is a subject of growing interest with the potential of delivering planar electro-optical devices with chip scale integration. Silicon-on-insulator (SOI) technology has provided a marvelous platform for photonics industry because of its advantages in integration capability in CMOS circuit and countless nonlinearity applications in optical signal processing. This thesis is focused on the investigation of planar imaging techniques on SOI platform and potential applications in ultra-fast optical signal processing. In the first part, a general review and background introduction about integrated photonics circuit and planar imaging technique are provided. In chapter 2, planar imaging platform is realized by a silicon photodiode on SOI chip. Silicon photodiode on waveguide provides a high numerical aperture for an imaging transceiver pixel. An erbium doped Y2O3 particle is excited by 1550nm Laser and the fluorescent image is obtained with assistance of the scanning system. Fluorescence image is reconstructed by using image de-convolution technique. Under photovoltaic mode, we use an on-chip photodiode and an external PIN photodiode to realize similar resolution as 5μm. In chapter 3, a time stretching technique is developed to a spatial domain to realize a 2D imaging system as an ultrafast imaging tool. The system is evaluated based on theoretical calculation. The experimental results are shown for a verification of system capability to imaging a micron size particle or a finger print. Meanwhile, dynamic information for a moving object is also achieved by correlation algorithm. In chapter 4, the optical leaky wave antenna based on SOI waveguide has been utilized for imaging applications and extensive numerical studied has been conducted. and the theoretical explanation is supported by leaky wave theory. The highly directive radiation has been obtained from the broadside with 15.7 dB directivity and a 3dB beam width of ΔØ 3dB ≈ 1.65° in free space

[Optical Design of Miniature Infrared Gratings Spectrometer Based on Planar Waveguide].

PubMed

Li, Yang-yu; Fang, Yong-hua; Li, Da-cheng; Liu, Yang

2015-03-01

In order to miniaturize an infrared spectrometer, we analyze the current optical design of miniature spectrometers and propose a method for designing a miniature infrared gratings spectrometer based on planar waveguide. Common miniature spectrometer uses miniature optical elements to reduce the size of system, which also shrinks the effective aperture. So the performance of spectrometer has dropped. Miniaturization principle of planar waveguide spectrometer is different from the principle of common miniature spectrometer. In planar waveguide spectrometer, the propagation of light is limited in a thin planar waveguide, which looks like the whole optical system is squashed flat. In the direction parallel to the planar waveguide, the light through the slit is collimated, dispersed and focused. And a spectral image is formed in the detector plane. This propagation of light is similar to the light in common miniature spectrometer. In the direction perpendicular to the planar waveguide, light is multiple reflected by the upper and lower surfaces of the planar waveguide and propagates in the waveguide. So the size of corresponding optical element could be very small in the vertical direction, which can reduce the size of the optical system. And the performance of the spectrometer is still good. The design method of the planar waveguide spectrometer can be separated into two parts, Czerny-Turner structure design and planar waveguide structure design. First, by using aberration theory an aberration-corrected (spherical aberration, coma, focal curve) Czerny-Turner structure is obtained. The operation wavelength range and spectral resolution are also fixed. Then, by using geometrical optics theory a planar waveguide structure is designed for reducing the system size and correcting the astigmatism. The planar waveguide structure includes a planar waveguide and two cylindrical lenses. Finally, they are modeled together in optical design software and are optimized as a whole. An

Planar zeros in gauge theories and gravity

NASA Astrophysics Data System (ADS)

Jiménez, Diego Medrano; Vera, Agustín Sabio; Vázquez-Mozo, Miguel Á.

2016-09-01

Planar zeros are studied in the context of the five-point scattering amplitude for gauge bosons and gravitons. In the case of gauge theories, it is found that planar zeros are determined by an algebraic curve in the projective plane spanned by the three stereographic coordinates labelling the direction of the outgoing momenta. This curve depends on the values of six independent color structures. Considering the gauge group SU( N) with N = 2 , 3 , 5 and fixed color indices, the class of curves obtained gets broader by increasing the rank of the group. For the five-graviton scattering, on the other hand, we show that the amplitude vanishes whenever the process is planar, without imposing further kinematic conditions. A rationale for this result is provided using color-kinematics duality.

Evanescent field refractometry in planar optical fiber.

PubMed

Holmes, Christopher; Jantzen, Alexander; Gray, Alan C; Gow, Paul C; Carpenter, Lewis G; Bannerman, Rex H S; Gates, James C; Smith, Peter G R

2018-02-15

This Letter demonstrates a refractometer in integrated optical fiber, a new optical platform that planarizes fiber using flame hydrolysis deposition (FHD). The unique advantage of the technology is survivability in harsh environments. The platform is mechanically robust, and can survive elevated temperatures approaching 1000°C and exposure to common solvents, including acetone, gasoline, and methanol. For the demonstrated refractometer, fabrication was achieved through wet etching an SMF-28 fiber to a diameter of 8 μm before FHD planarization. An external refractive index was monitored using fiber Bragg gratings (FBGs), written into the core of the planarized fiber. A direct comparison to alternative FBG refractometers is made, for which the developed platform is shown to have comparable sensitivity, with the added advantage of survivability in harsh environments.

Insight into Evolution, Processing and Performance of Multi-length-scale Structures in Planar Heterojunction Perovskite Solar Cells.

PubMed

Huang, Yu-Ching; Tsao, Cheng-Si; Cho, Yi-Ju; Chen, Kuan-Chen; Chiang, Kai-Ming; Hsiao, Sheng-Yi; Chen, Chang-Wen; Su, Chun-Jen; Jeng, U-Ser; Lin, Hao-Wu

2015-09-04

The structural characterization correlated to the processing control of hierarchical structure of planar heterojunction perovskite layer is still incomplete due to the limitations of conventional microscopy and X-ray diffraction. This present study performed the simultaneously grazing-incidence small-angle scattering and wide-angle scattering (GISAXS/GIWAXS) techniques to quantitatively probe the hierarchical structure of the planar heterojunction perovskite solar cells. The result is complementary to the currently microscopic study. Correlation between the crystallization behavior, crystal orientation, nano- and meso-scale internal structure and surface morphology of perovskite film as functions of various processing control parameters is reported for the first time. The structural transition from the fractal pore network to the surface fractal can be tuned by the chloride percentage. The GISAXS/GIWAXS measurement provides the comprehensive understanding of concurrent evolution of the film morphology and crystallization correlated to the high performance. The result can provide the insight into formation mechanism and rational synthesis design.

Insight into Evolution, Processing and Performance of Multi-length-scale Structures in Planar Heterojunction Perovskite Solar Cells

NASA Astrophysics Data System (ADS)

Huang, Yu-Ching; Tsao, Cheng-Si; Cho, Yi-Ju; Chen, Kuan-Chen; Chiang, Kai-Ming; Hsiao, Sheng-Yi; Chen, Chang-Wen; Su, Chun-Jen; Jeng, U.-Ser; Lin, Hao-Wu

2015-09-01

The structural characterization correlated to the processing control of hierarchical structure of planar heterojunction perovskite layer is still incomplete due to the limitations of conventional microscopy and X-ray diffraction. This present study performed the simultaneously grazing-incidence small-angle scattering and wide-angle scattering (GISAXS/GIWAXS) techniques to quantitatively probe the hierarchical structure of the planar heterojunction perovskite solar cells. The result is complementary to the currently microscopic study. Correlation between the crystallization behavior, crystal orientation, nano- and meso-scale internal structure and surface morphology of perovskite film as functions of various processing control parameters is reported for the first time. The structural transition from the fractal pore network to the surface fractal can be tuned by the chloride percentage. The GISAXS/GIWAXS measurement provides the comprehensive understanding of concurrent evolution of the film morphology and crystallization correlated to the high performance. The result can provide the insight into formation mechanism and rational synthesis design.

Process for forming planarized films

DOEpatents

Pang, Stella W.; Horn, Mark W.

1991-01-01

A planarization process and apparatus which employs plasma-enhanced chemical vapor deposition (PECVD) to form plarnarization films of dielectric or conductive carbonaceous material on step-like substrates.

Planar Submillimeter-Wave Mixer Technology with Integrated Antenna

NASA Technical Reports Server (NTRS)

Chattopadhyay, Gautam; Mehdi, Imran; Gill, John J.; Lee, Choonsup; lombart, Muria L.; Thomas, Betrand

2010-01-01

High-performance mixers at terahertz frequencies require good matching between the coupling circuits such as antennas and local oscillators and the diode embedding impedance. With the availability of amplifiers at submillimeter wavelengths and the need to have multi-pixel imagers and cameras, planar mixer architecture is required to have an integrated system. An integrated mixer with planar antenna provides a compact and optimized design at terahertz frequencies. Moreover, it leads to a planar architecture that enables efficient interconnect with submillimeter-wave amplifiers. In this architecture, a planar slot antenna is designed on a thin gallium arsenide (GaAs) membrane in such a way that the beam on either side of the membrane is symmetric and has good beam profile with high coupling efficiency. A coplanar waveguide (CPW) coupled Schottky diode mixer is designed and integrated with the antenna. In this architecture, the local oscillator (LO) is coupled through one side of the antenna and the RF from the other side, without requiring any beam sp litters or diplexers. The intermediate frequency (IF) comes out on a 50-ohm CPW line at the edge of the mixer chip, which can be wire-bonded to external circuits. This unique terahertz mixer has an integrated single planar antenna for coupling both the radio frequency (RF) input and LO injection without any diplexer or beamsplitters. The design utilizes novel planar slot antenna architecture on a 3- mthick GaAs membrane. This work is required to enable future multi-pixel terahertz receivers for astrophysics missions, and lightweight and compact receivers for planetary missions to the outer planets in our solar system. Also, this technology can be used in tera hertz radar imaging applications as well as for testing of quantum cascade lasers (QCLs).

Treatment Parameters and Outcome in 680 Treatments of Internal Radiation With Resin {sup 90}Y-Microspheres for Unresectable Hepatic Tumors

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

Kennedy, Andrew S.; McNeillie, Patrick M.S.; Dezarn, William A.

Purpose: Radioembolization (RE) using {sup 90}Y-microspheres is an effective and safe treatment for patients with unresectable liver malignancies. Radiation-induced liver disease (RILD) is rare after RE; however, greater understanding of radiation-related factors leading to serious liver toxicity is needed. Methods and Materials: Retrospective review of radiation parameters was performed. All data pertaining to demographics, tumor, radiation, and outcomes were analyzed for significance and dependencies to develop a predictive model for RILD. Toxicity was scored using the National Cancer Institute Common Toxicity Criteria Adverse Events Version 3.0 scale. Results: A total of 515 patients (287 men; 228 women) from 14 USmore » and 2 EU centers underwent 680 separate RE treatments with resin {sup 90}Y-microspheres in 2003-2006. Multifactorial analyses identified factors related to toxicity, including activity (GBq) Selective Internal Radiation Therapy delivered (p < 0.0001), prescribed (GBq) activity (p < 0.0001), percentage of empiric activity (GBq) delivered (p < 0.0001), number of prior liver treatments (p < 0.0008), and medical center (p < 0.0001). The RILD was diagnosed in 28 of 680 treatments (4%), with 21 of 28 cases (75%) from one center, which used the empiric method. Conclusions: There was an association between the empiric method, percentage of calculated activity delivered to the patient, and the most severe toxicity, RILD. A predictive model for RILD is not yet possible given the large variance in these data.« less

Hydrogenated arsenenes as planar magnet and Dirac material

NASA Astrophysics Data System (ADS)

Zhang, Shengli; Hu, Yonghong; Hu, Ziyu; Cai, Bo; Zeng, Haibo

2015-07-01

Arsenene and antimonene are predicted to have 2.49 and 2.28 eV band gaps, which have aroused intense interest in the two-dimensional (2D) semiconductors for nanoelectronic and optoelectronic devices. Here, the hydrogenated arsenenes are reported to be planar magnet and 2D Dirac materials based on comprehensive first-principles calculations. The semi-hydrogenated (SH) arsenene is found to be a quasi-planar magnet, while the fully hydrogenated (FH) arsenene is a planar Dirac material. The buckling height of pristine arsenene is greatly decreased by the hydrogenation, resulting in a planar and relatively low-mass-density sheet. The electronic structures of arsenene are also evidently altered after hydrogenating from wide-band-gap semiconductor to metallic material for SH arsenene, and then to Dirac material for FH arsenene. The SH arsenene has an obvious magnetism, mainly contributed by the p orbital of the unsaturated As atom. Such magnetic and Dirac materials modified by hydrogenation of arsenene may have potential applications in future optoelectronic and spintronic devices.

Assembly and positioning of actomyosin rings by contractility and planar cell polarity

PubMed Central

Sehring, Ivonne M; Recho, Pierre; Denker, Elsa; Kourakis, Matthew; Mathiesen, Birthe; Hannezo, Edouard; Dong, Bo; Jiang, Di

2015-01-01

The actomyosin cytoskeleton is a primary force-generating mechanism in morphogenesis, thus a robust spatial control of cytoskeletal positioning is essential. In this report, we demonstrate that actomyosin contractility and planar cell polarity (PCP) interact in post-mitotic Ciona notochord cells to self-assemble and reposition actomyosin rings, which play an essential role for cell elongation. Intriguingly, rings always form at the cells′ anterior edge before migrating towards the center as contractility increases, reflecting a novel dynamical property of the cortex. Our drug and genetic manipulations uncover a tug-of-war between contractility, which localizes cortical flows toward the equator and PCP, which tries to reposition them. We develop a simple model of the physical forces underlying this tug-of-war, which quantitatively reproduces our results. We thus propose a quantitative framework for dissecting the relative contribution of contractility and PCP to the self-assembly and repositioning of cytoskeletal structures, which should be applicable to other morphogenetic events. DOI: http://dx.doi.org/10.7554/eLife.09206.001 PMID:26486861

Fabrication of the planar angular rotator using the CMOS process

NASA Astrophysics Data System (ADS)

Dai, Ching-Liang; Chang, Chien-Liu; Chen, Hung-Lin; Chang, Pei-Zen

2002-05-01

In this investigation we propose a novel planar angular rotator fabricated by the conventional complementary metal-oxide semiconductor (CMOS) process. Following the 0.6 μm single poly triple metal (SPTM) CMOS process, the device is completed by a simple maskless, post-process etching step. The rotor of the planar angular rotator rotates around its geometric center with electrostatic actuation. The proposed design adopts an intelligent mechanism including the slider-crank system to permit simultaneous motion. The CMOS planar angular rotator could be driven with driving voltages of around 40 V. The design proposed here has a shorter response time and longer life, without problems of friction and wear, compared to the more common planar angular micromotor.

Yttrium-90 DOTA peptide chimeric L6 toxicity and therapeutic potential in nude mice with human breast tumors

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

DeNardo, S.J.; Zhong, G.R.; Miers, L.A.

1994-05-01

Chimeric L6 MoAb (ChL6) as I-131 ChL6 has shown therapeutic promise for radioimmunotherapy in breast cancer patients. In order to enhance this therapeutic potential, we have developed an yttrium-90 (Y-90) ChL6 radiopharmaceutical by conjugating Y-90 DOTA peptide to ChL6 using DOTA-Gly-3L(p-isothiocyanato)-Phe-NH2. This DOTA peptide forms neutral complexes with trivalent metals allowing excess chelating agents and divalent metal complexes to be removed by ion exchange chromatography prior to conjugation, thus yielding a high Y-90/DOTA ratio on the final immune conjugate. Groups of 9-10 nude mice bearing subcutaneous 40-200 mg HBT 3477 xenographs were given 150,250,350,400,450 or 500 {mu}Ci of Y-90 DOTAmore » peptide ChL6 (specific activity 1.1-3.5 {mu}Ci/{mu}g). Live cell immunoreactivity was 73-80% and 100% Y-90 moved with ChL6 on SEC3000 HPLC and TLC. Peripheral blood counts, weight, tumor size, blood and body clearance of Y-90 were monitored for 10 weeks. Whole body autoradiography was performed at 1,3 and 5 days post injection at the 250 and 450 {mu}Ci dose levels. No mouse that received less than 450 {mu}Ci of Y-90 died. The LD50/30 was 479 {mu}Ci. The nadirs of RBC, WBC and platelets were 10-20 days post 479 {mu}Ci. The nadirs of RBC, WBC and platelets were 10-20 days post injection. The depth of the nadir was dose dependent but occured in all groups. In the lowest dose group having substantial tumor response (350{mu}Ci) mean tumor volume decreased by >50% and 5 of 19 tumors completely regressed over the 10 week follow-up. This is the greatest LD50/30 for Y-90 immunoconjugate reported in nude mice to date. These results confirm the significance of the biodistribution and autoradiographic studies demonstrating tumor uptake of 18 {plus_minus} 8% ID/gm with 3/1 tumor to liver and 8/1 tumor to bone ratios 1, 3, and 5 days post injection.« less

Simulation of Electric Potentials and Ion Motion in Planar Electrode Structures for Lossless Ion Manipulations (SLIM)

DOE PAGES

Garimella, Sandilya V. B; Ibrahim, Yehia M.; Webb, Ian K.; ...

2014-09-26

Here we report a conceptual study and computational evaluation of novel planar electrode Structures for Lossless Ion Manipulations (SLIM). Planar electrode SLIM devices were designed that allow for flexible ion confinement, transport and storage using a combination of RF and DC fields. Effective potentials can be generated that provide near ideal regions for confining ions in the presence of a gas. Ion trajectory simulations using SIMION 8.1 demonstrated the capability for lossless ion motion in these devices over a wide m/z range and a range of electric fields at low pressures (e.g. a few torr). More complex ion manipulations, e.g.more » turning ions by 90° and dynamically switching selected ion species into orthogonal channels, are also feasible. Lastly, the performance of SLIM devices at ~4 torr pressure for performing ion mobility based separations (IMS) is computationally evaluated and compared to initial experimental results, and both of which agree closely with experimental and theoretical IMS performance for a conventional drift tube design.« less

Delivering both sum and difference beam distributions to a planar monopulse antenna array

DOEpatents

Strassner, II, Bernd H.

2015-12-22

A planar monopulse radar apparatus includes a planar distribution matrix coupled to a planar antenna array having a linear configuration of antenna elements. The planar distribution matrix is responsive to first and second pluralities of weights applied thereto for providing both sum and difference beam distributions across the antenna array.

Calibration of the NPL secondary standard radionuclide calibrator for 32P, 89Sr and 90Y

NASA Astrophysics Data System (ADS)

Woods, M. J.; Munster, A. S.; Sephton, J. P.; Lucas, S. E. M.; Walsh, C. Paton

1996-02-01

Pure beta particle emitting radionuclides have many therapeutic applications in nuclear medicine. The response of the NPL secondary standard radionuclide calibrator to 32P, 89Sr and 90Y has been measured using accurately calibrated solutions. For this purpose, high efficiency solid sources were prepared gravimetrically from dilute solutions of each radionuclide and assayed in a 4π proportional counter; the source activities were determined using known detection efficiency factors. Measurements were made of the current response (pA/MBq) of the NPL secondary standard radionuclide calibrator using the original concentrated solutions. Calibration figures have been derived for 2 and 5 ml British Standard glass ampoules and Amersham International plc P6 vials. Volume correction factors have also been determined. Gamma-ray emitting contaminants can have a disproportionate effect on the calibrator response and particular attention has been paid to this.

Planar Impacts in Rollover Crashes: Significance, Distribution and Injury Epidemiology

PubMed Central

Bose, Dipan; Kerrigan, Jason R.; Foster, Jonathan B.; Crandall, Jeff R.; Tobaru, Shigeo

2011-01-01

While one third of all fatal motor vehicle crashes involve rollover of the vehicle, a substantially large portion of these rollover crashes involve planar impacts (e.g., frontal, side or rear impact) that influence the crash kinematics and subsequently the injury outcome. The objective of the study was to evaluate the distribution of planar impacts in rollover crashes, and in particular, to describe the differences in the underlying crash kinematics, injury severity and the regional distribution of injuries when compared to the rollover-dominated crashes without significant planar impact (i.e., primary rollovers). Sampled cases (n=6,900) from the U.S. National Automotive Sampling System – Crashworthiness Data System, representing approximately 3.3 million belted drivers involved in a rollover crash in years 1998–2008, were analyzed. Single vehicle rollover crashes with significant planar impact (21% of all rollover crashes) were in general more likely to result in occupant fatality and involved higher incidence of moderate to severe injuries compared to single vehicle primary rollovers (p<0.05). A substantial proportion of the planar impact rollovers ended in single quarter turn crashes (30%), mostly resulting from a frontal impact (59%). While chest was the most frequently injured body region among all rollover victims sustaining severe injuries, severe injuries sustained in primary rollovers were more isolated (single body region) in comparison to the ones sustained in rollovers with planar impacts. The results emphasize the higher risk of rollover victims sustaining an injury and the differences in distribution of injuries sustained when a planar impact is associated with the rollover crash. PMID:22105400

Electrolytic Cell For Production Of Aluminum Employing Planar Anodes.

DOEpatents

Barnett, Robert J.; Mezner, Michael B.; Bradford, Donald R

2004-10-05

A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte, the method comprising providing a molten salt electrolyte having alumina dissolved therein in an electrolytic cell. A plurality of anodes and cathodes having planar surfaces are disposed in a generally vertical orientation in the electrolyte, the anodes and cathodes arranged in alternating or interleaving relationship to provide anode planar surfaces disposed opposite cathode planar surfaces, the anode comprised of carbon. Electric current is passed through anodes and through the electrolyte to the cathodes depositing aluminum at the cathodes and forming carbon containing gas at the anodes.

(90)Y-labelled anti-CD22 epratuzumab tetraxetan in adults with refractory or relapsed CD22-positive B-cell acute lymphoblastic leukaemia: a phase 1 dose-escalation study.

PubMed

Chevallier, Patrice; Eugene, Thomas; Robillard, Nelly; Isnard, Françoise; Nicolini, Franck; Escoffre-Barbe, Martine; Huguet, Françoise; Hunault, Mathilde; Marcais, Antoine; Gaschet, Joelle; Cherel, Michel; Guillaume, Thierry; Delaunay, Jacques; Peterlin, Pierre; Eveillard, Marion; Thomas, Xavier; Ifrah, Norbert; Lapusan, Simona; Bodet-Milin, Caroline; Barbet, Jacques; Faivre-Chauvet, Alain; Ferrer, Ludovic; Bene, Marie C; Le Houerou, Claire; Goldenberg, David M; Wegener, William A; Kraeber-Bodéré, Françoise

2015-03-01

Prognosis of patients with relapsed or refractory acute lymphoblastic leukaemia is poor and new treatments are needed. We aimed to assess the feasibility, tolerability, dosimetry, and efficacy of yttrium-90-labelled anti-CD22 epratuzumab tetraxetan ((90)Y-DOTA-epratuzumab) radioimmunotherapy in refractory or relapsed CD22-positive B-cell acute lymphoblastic leukaemia in a standard 3 + 3 phase 1 study. Adults (≥18 years) with relapsed or refractory B-cell acute lymphoblastic leukaemia (with CD22 expression on at least 70% of blast cells) were enrolled at six centres in France. Patients received one cycle of (90)Y-DOTA-epratuzumab on days 1 and 8 (give or take 2 days) successively at one of four dose levels: 2·5 mCi/m(2) (92·5 MBq/m(2); level 1), 5·0 mCi/m(2) (185 MBq/m(2); level 2), 7·5 mCi/m(2) (277·5 MBq/m(2); level 3), and 10·0 mCi/m(2) (370 MBq/m(2); level 4). The primary objective was to identify the maximum tolerated dose of (90)Y-DOTA-epratuzumab. We assessed safety during infusions and regularly after radioimmunotherapy over a 6-month period. Analyses included only patients who received radioimmunotherapy. The trial is closed to inclusion and is registered at ClinicalTrials.gov, NCT01354457. Between Aug 25, 2011, and June 11, 2014, 17 patients (median age 62 years; range 27-77) were treated (five at level 1, three at level 2, three at level 3, and six at level 4). Radioimmunotherapy infusion was overall well tolerated. One dose-limiting toxic effect (aplasia lasting 8 weeks) occurred at level 4, but the maximum tolerated dose was not reached. The most common grade 3-4 adverse events were pancytopenia (one patient at level 2, one at level 3, and six at level 4) and infections (three at level 1, one at level 2, and five at level 4). (90)Y-DOTA-epratuzumab radioimmunotherapy is well tolerated. We recommend the dose of 2 × 10·0 mCi/m(2) 1 week apart per cycle for phase 2 studies. Immunomedics and Direction de la Recherche Clinique of Nantes

90Y Liver Radioembolization Imaging Using Amplitude-Based Gated PET/CT.

PubMed

Osborne, Dustin R; Acuff, Shelley; Neveu, Melissa; Kaman, Austin; Syed, Mumtaz; Fu, Yitong

2017-05-01

The usage of PET/CT to monitor patients with hepatocellular carcinoma following Y radioembolization has increased; however, image quality is often poor because of low count efficiency and respiratory motion. Motion can be corrected using gating techniques but at the expense of additional image noise. Amplitude-based gating has been shown to improve quantification in FDG PET, but few have used this technique in Y liver imaging. The patients shown in this work indicate that amplitude-based gating can be used in Y PET/CT liver imaging to provide motion-corrected images with higher estimates of activity concentration that may improve posttherapy dosimetry.

Capillary rise between planar surfaces

NASA Astrophysics Data System (ADS)

Bullard, Jeffrey W.; Garboczi, Edward J.

2009-01-01

Minimization of free energy is used to calculate the equilibrium vertical rise and meniscus shape of a liquid column between two closely spaced, parallel planar surfaces that are inert and immobile. States of minimum free energy are found using standard variational principles, which lead not only to an Euler-Lagrange differential equation for the meniscus shape and elevation, but also to the boundary conditions at the three-phase junction where the liquid meniscus intersects the solid walls. The analysis shows that the classical Young-Dupré equation for the thermodynamic contact angle is valid at the three-phase junction, as already shown for sessile drops with or without the influence of a gravitational field. Integration of the Euler-Lagrange equation shows that a generalized Laplace-Young (LY) equation first proposed by O’Brien, Craig, and Peyton [J. Colloid Interface Sci. 26, 500 (1968)] gives an exact prediction of the mean elevation of the meniscus at any wall separation, whereas the classical LY equation for the elevation of the midpoint of the meniscus is accurate only when the separation approaches zero or infinity. When both walls are identical, the meniscus is symmetric about the midpoint, and the midpoint elevation is a more traditional and convenient measure of capillary rise than the mean elevation. Therefore, for this symmetric system a different equation is fitted to numerical predictions of the midpoint elevation and is shown to give excellent agreement for contact angles between 15° and 160° and wall separations up to 30mm . When the walls have dissimilar surface properties, the meniscus generally assumes an asymmetric shape, and significant elevation of the liquid column can occur even when one of the walls has a contact angle significantly greater than 90°. The height of the capillary rise depends on the spacing between the walls and also on the difference in contact angles at the two surfaces. When the contact angle at one wall is greater

Planar Tunneling Spectroscopy of Graphene Nanodevices

NASA Astrophysics Data System (ADS)

Wang, Joel I.-Jan; Bretheau, Landry; Pisoni, Riccardo; Watanabe, Kenji; Taniguchi, Takashi; Jarillo-Herrero, Pablo

2-D Van-der-Waals mesoscopic physics have seen a rapid development in the last 10 years, with new materials each year added to the toolbox. Stacking them like Lego enables the combination of their individual electronic properties. In particular, hexagonal boron nitride, which is an insulator, gives the possibility to perform planar (2-D to 2-D) tunneling spectroscopy within this type of heterostructures. Unlike standard transport measurements, tunneling spectroscopy enables to probe the electronic properties in the energy domain. Moreover, since planar tunneling probes a large area of the system, global quantum features such as quantum Hall effect, superconducting proximity effect or quantum confinement can be investigated. In this talk, we will present implementation of heterostructures consisting of graphene, hexagonal boron nitride, and graphite, fabricated for planar tunneling spectroscopy. In order to reveal the intrinsic properties of materials, the fabrication scheme aims at preserving the pristine nature of the 2-DEGS as well as minimizing the doping introduced by external probes. As a demonstration, measurements of these devices in normal states, high magnetic field environment, and induced superconducting state will be presented.

Cloning of a heat shock protein 90 (HSP90) gene and expression analysis in the ridgetail white prawn Exopalaemon carinicauda.

PubMed

Li, Jitao; Han, Junying; Chen, Ping; Chang, Zhiqiang; He, Yuying; Liu, Ping; Wang, Qingyin; Li, Jian

2012-06-01

Heat shock protein 90 (HSP90) is a highly conserved molecular chaperone contributing to the folding, maintenance of structural integrity and proper regulation of a subset of cytosolic proteins. In this study, a heat shock protein 90 cDNA named EcHSP90 was cloned from the hepatopancreas of ridgetail white prawn Exopalaemon carinicauda by reverse transcription polymerase chain reaction (RT-PCR) coupled with rapid amplification of cDNA ends (RACE) approaches. The full-length cDNA of EcHSP90 was of 2695 bp, including an open reading frame (ORF) of 2163 bp encoding a polypeptide of 720 amino acids with an estimated molecular mass of 82.73 kDa and an estimated isoelectric point of 4.83. BLAST analysis revealed that the EcHSP90 shared high similarity (87.6%-75.24%) with other known HSP90s. The five conserved amino acid blocks defined as HSP90 protein family signatures were also identified in EcHSP90, which indicated that EcHSP90 should be a cytosolic member of the HSP90 family. Quantitative real-time RT-PCR analysis revealed that EcHSP90 transcript could be detected in all the tested tissues, and strongly expressed in ovary of E. carinicauda. The transcript of EcHSP90 in hepatopancreas of E. carinicauda showed different expression profiles after pH and ammonia-N stresses. The results indicated that EcHSP90 was a constitutive and inducible expressed protein and could be induced by various stresses from environment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Complementary approaches for the evaluation of biocompatibility of 90Y-labeled superparamagnetic citric acid (Fe,Er)3O4 coated nanoparticles.

PubMed

Antic, Bratislav; Boskovic, Marko; Nikodinovic-Runic, Jasmina; Ming, Yue; Zhang, Hongguo; Bozin, Emil S; Janković, Drina; Spasojevic, Vojislav; Vranjes-Djuric, Sanja

2017-06-01

Magnetic nanoparticles (MNPs) are of immense interest for diagnostic and therapeutic applications in medicine. Design and development of new iron oxide-based MNPs for such applications is of rather limited breadth without reliable and sensitive methods to determine their levels in body tissues. Commonly used methods, such as ICP, are quite problematic, due to the inability to decipher the origin of the detected iron, i.e. whether it originates from the MNPs or endogenous from tissues and bodily fluids. One of the approaches to overcome this problem and to increase reliability of tracing MNPs is to partially substitute iron ions in the MNPs with Er. Here, we report on the development of citric acid coated (Fe,Er) 3 O 4 nanoparticles and characterization of their physico-chemical and biological properties by utilization of various complementary approaches. The synthesized MNPs had a narrow (6-7nm) size distribution, as consistently seen in atomic pair distribution function, transmission electron microscopy, and DC magnetization measurements. The particles were found to be superparamagnetic, with a pronounced maximum in measured zero-field cooled magnetization at around 90K. Reduction in saturation magnetization due to incorporation of 1.7% Er 3+ into the Fe 3 O 4 matrix was clearly observed. From the biological standpoint, citric acid coated (Fe,Er) 3 O 4 NPs were found to induce low toxicity both in human cell fibroblasts and in zebrafish (Danio rerio) embryos. Biodistribution pattern of the MNPs after intravenous administration in healthy Wistar rats was followed by the radiotracer method, revealing that 90 Y-labeled MNPs were predominantly found in liver (75.33% ID), followed by lungs (16.70% ID) and spleen (2.83% ID). Quantitative agreement with these observations was obtained by ICP-MS elemental analysis using Er as the detected tracer. Based on the favorable physical, chemical and biological characteristics, citric acid coated (Fe,Er) 3 O 4 MNPs could be

Complementary approaches for the evaluation of biocompatibility of 90Y-labeled superparamagnetic citric acid (Fe,Er) 3O 4 coated nanoparticles

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

Antic, Bratislav; Boskovic, Marko; Nikodinovic-Runic, Jasmina

Magnetic nanoparticles (MNPs) are of immense interest for diagnostic and therapeutic applications in medicine. Design and development of new iron oxide-based MNPs for such applications is of rather limited breadth without reliable and sensitive methods to determine their levels in body tissues. Commonly used methods, such as ICP, are quite problematic, due to the inability to decipher the origin of the detected iron, i.e. whether it originates from the MNPs or endogenous from tissues and bodily fluids. One of the approaches to overcome this problem and to increase reliability of tracing MNPs is to partially substitute iron ions in themore » MNPs with Er. Here, we report on the development of citric acid coated (Fe,Er) 3O 4 nanoparticles and characterization of their physico-chemical and biological properties by utilization of various complementary approaches. The synthesized MNPs had a narrow (6–7 nm) size distribution, as consistently seen in atomic pair distribution function, transmission electron microscopy, and DC magnetization measurements. The particles were found to be superparamagnetic, with a pronounced maximum in measured zero-field cooled magnetization at around 90 K. Reduction in saturation magnetization due to incorporation of 1.7% Er 3+ into the Fe 3O 4 matrix was clearly observed. From the biological standpoint, citric acid coated (Fe,Er) 3O 4 NPs were found to induce low toxicity both in human cell fibroblasts and in zebrafish ( Danio rerio) embryos. Biodistribution pattern of the MNPs after intravenous administration in healthy Wistar rats was followed by the radiotracer method, revealing that 90Y-labeled MNPs were predominantly found in liver (75.33% ID), followed by lungs (16.70% ID) and spleen (2.83% ID). Quantitative agreement with these observations was obtained by ICP-MS elemental analysis using Er as the detected tracer. Based on the favorable physical, chemical and biological characteristics, citric acid coated (Fe,Er) 3O 4 MNPs could

Complementary approaches for the evaluation of biocompatibility of 90Y-labeled superparamagnetic citric acid (Fe,Er) 3O 4 coated nanoparticles

DOE PAGES

Antic, Bratislav; Boskovic, Marko; Nikodinovic-Runic, Jasmina; ...

2017-02-10

Magnetic nanoparticles (MNPs) are of immense interest for diagnostic and therapeutic applications in medicine. Design and development of new iron oxide-based MNPs for such applications is of rather limited breadth without reliable and sensitive methods to determine their levels in body tissues. Commonly used methods, such as ICP, are quite problematic, due to the inability to decipher the origin of the detected iron, i.e. whether it originates from the MNPs or endogenous from tissues and bodily fluids. One of the approaches to overcome this problem and to increase reliability of tracing MNPs is to partially substitute iron ions in themore » MNPs with Er. Here, we report on the development of citric acid coated (Fe,Er) 3O 4 nanoparticles and characterization of their physico-chemical and biological properties by utilization of various complementary approaches. The synthesized MNPs had a narrow (6–7 nm) size distribution, as consistently seen in atomic pair distribution function, transmission electron microscopy, and DC magnetization measurements. The particles were found to be superparamagnetic, with a pronounced maximum in measured zero-field cooled magnetization at around 90 K. Reduction in saturation magnetization due to incorporation of 1.7% Er 3+ into the Fe 3O 4 matrix was clearly observed. From the biological standpoint, citric acid coated (Fe,Er) 3O 4 NPs were found to induce low toxicity both in human cell fibroblasts and in zebrafish ( Danio rerio) embryos. Biodistribution pattern of the MNPs after intravenous administration in healthy Wistar rats was followed by the radiotracer method, revealing that 90Y-labeled MNPs were predominantly found in liver (75.33% ID), followed by lungs (16.70% ID) and spleen (2.83% ID). Quantitative agreement with these observations was obtained by ICP-MS elemental analysis using Er as the detected tracer. Based on the favorable physical, chemical and biological characteristics, citric acid coated (Fe,Er) 3O 4 MNPs could

Practical sliced configuration spaces for curved planar pairs

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

Sacks, E.

1999-01-01

In this article, the author presents a practical configuration-space computation algorithm for pairs of curved planar parts, based on the general algorithm developed by Bajaj and the author. The general algorithm advances the theoretical understanding of configuration-space computation, but is too slow and fragile for some applications. The new algorithm solves these problems by restricting the analysis to parts bounded by line segments and circular arcs, whereas the general algorithm handles rational parametric curves. The trade-off is worthwhile, because the restricted class handles most robotics and mechanical engineering applications. The algorithm reduces run time by a factor of 60 onmore » nine representative engineering pairs, and by a factor of 9 on two human-knee pairs. It also handles common special pairs by specialized methods. A survey of 2,500 mechanisms shows that these methods cover 90% of pairs and yield an additional factor of 10 reduction in average run time. The theme of this article is that application requirements, as well as intrinsic theoretical interest, should drive configuration-space research.« less

Tissue distribution of co-planar and non-planar tetra- and hexa-chlorobiphenyl isomers in guinea pigs after oral ingestion

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

Jan, J.; Logar, B.; Jan, J.

1996-03-01

Food ingestion is the most important route for the uptake of lipophilic organochlorine contaminants. Uptake and transfer of the contaminants from the digestive tract to target organs can be used for risk evaluation. The bioconcentration and migration of polychlorobiphenyls (PCBs) is highly structure - dependent. Bioconcentration is correlated with lipophilicity on the basis of the n-octanol/water partition coefficient in its logarithmic form - logKow. However, some factors e.g. diffusion through cell membranes, accumulation in specific organs and tissues, uptake and deputation kinetics and metabolism can also influence the bioconcentration. Individual PCB compounds of commercial PCB preparation are taken up bymore » organisms to markedly different extents. Until now little is known about the distribution of non-planar and co-planar PCBs in different tissues. Co-planar PCBs have dioxin - like toxicity. This study examines differences in the bioconcentration of two pairs of tetra and hexa chlorobiphenyls from the digestive tract and their distribution in different tissues of guinea pigs.« less

Planar Lattice Instability in LA2CUO4.1 across the Superconducting Transition

NASA Astrophysics Data System (ADS)

Acosta-Alejandro, Manuel; Mustre-de Leon, Jose; Conradson, Steven

2001-03-01

The local atomic structure of La2CuO4.1 around Cu K-edge is analyzed for 10planar) EXAFS contribution using a Gaussian radial distribution function (RDF) and a double peeked RDF, derived from model double-well potentials. Away from the superconducting transition, we find that the spectra is consistent with a double-peeked RDF, in agreement with other studies. However, in th neighborhood of the superconducting transition the RDF becomes single peaked. This work was partially supported by Consejo Nacional de Ciencia y Tecnología (CONACYT, México) under Grant. No. 31274-U.

The significance of 99mTc-MAA SPECT/CT liver perfusion imaging in treatment planning for 90Y-microsphere selective internal radiation treatment.

PubMed

Ahmadzadehfar, Hojjat; Sabet, Amir; Biermann, Kim; Muckle, Marianne; Brockmann, Holger; Kuhl, Christiane; Wilhelm, Kai; Biersack, Hans-Jürgen; Ezziddin, Samer

2010-08-01

Selective internal radiation therapy (SIRT), a catheter-based liver-directed modality for treating primary and metastatic liver cancer, requires appropriate planning to maximize its therapeutic response and minimize its side effects. (99m)Tc-macroaggregated albumin (MAA) scanning should precede the therapy to detect any extrahepatic shunting to the lung or gastrointestinal tract. Our aim was to compare the ability of SPECT/CT with that of planar imaging and SPECT in the detection and localization of extrahepatic (99m)Tc-MAA accumulation and to evaluate the impact of SPECT/CT on SIRT treatment planning and its added value to angiography in this setting. Ninety diagnostic hepatic angiograms with (99m)Tc-MAA were obtained for 76 patients with different types of cancer. All images were reviewed retrospectively for extrahepatic MAA deposition in the following order: planar, non-attenuation-corrected SPECT, and SPECT/CT. Review of angiograms and follow-up of patients with abdominal shunting served as reference standards. Extrahepatic accumulation was detected by planar imaging, SPECT, and SPECT/CT in 12%, 17%, and 42% of examinations, respectively. The sensitivity for detecting extrahepatic shunting with planar imaging, SPECT, and SPECT/CT was 32%, 41%, and 100%, respectively; specificity was 98%, 98%, and 93%, respectively. The respective positive predictive values were 92%, 93%, and 89%, and the respective negative predictive values were 71%, 73%, and 100%. The therapy plan was changed according to the results of planar imaging, SPECT, and SPECT/CT in 7.8%, 8.9%, and 29% of patients, respectively. In pre-SIRT planning, (99m)Tc-MAA SPECT/CT is valuable for identifying extrahepatic visceral sites at risk for postradioembolization complications.

The planar shape of drumlins

NASA Astrophysics Data System (ADS)

Spagnolo, Matteo; Clark, Chris D.; Hughes, Anna L. C.; Dunlop, Paul; Stokes, Chris R.

2010-12-01

The asymmetry of the planar shape of drumlins is an established paradigm in the literature and characterizes drumlins as resembling tear drops with a blunt (bullet-shaped) stoss end and a tapering (pointed) lee end. It is widely cited and never been seriously questioned. In this paper, the planar shape of 44,500 drumlins mapped in various regional settings from drumlin fields in North America and Northern Europe were objectively analysed by means of Geographic Information System tools. Two parameters were considered. The first (denoted here as Aspl) focuses on the relative position of the point of intersection between the axes of the maximum length and the maximum width. It is defined as the distance between the upstream (i.e. beginning of the drumlin) and the intersection point (measured along the longitudinal axis) divided by the entire length of the long axis. Results indicate that the intersection point of the majority of drumlins (64%) is very close to the longitudinal midpoint (0.33 < Aspl < 0.66). The second parameter ( Aspl _A) is defined as the ratio between the area of the upstream half of the drumlin to that of the entire drumlin. Results show that for most drumlins (81%), the upper half area is almost as large as the down-half (0.45 < Aspl _A < 0.55). Taken together, these results concordantly indicate that drumlin planar shape has a strong tendency to be longitudinally symmetric and that the long-established paradigm of their plan form is false.

Modeling and analysis of a novel planar eddy current damper

NASA Astrophysics Data System (ADS)

Zhang, He; Kou, Baoquan; Jin, Yinxi; Zhang, Lu; Zhang, Hailin; Li, Liyi

2014-05-01

In this paper, a novel 2-DOF permanent magnet planar eddy current damper is proposed, of which the stator is made of a copper plate and the mover is composed of two orthogonal 1-D permanent magnet arrays with a double sided structure. The main objective of the planar eddy current damper is to provide two orthogonal damping forces for dynamic systems like the 2-DOF high precision positioning system. Firstly, the basic structure and the operating principle of the planar damper are introduced. Secondly, the analytical model of the planar damper is established where the magnetic flux density distribution of the permanent magnet arrays is obtained by using the equivalent magnetic charge method and the image method. Then, the analytical expressions of the damping force and damping coefficient are derived. Lastly, to verify the analytical model, the finite element method (FEM) is adopted for calculating the flux density and a planar damper prototype is manufactured and thoroughly tested. The results from FEM and experiments are in good agreement with the ones from the analytical expressions indicating that the analytical model is reasonable and correct.

Direct quantitation of thoracic gallium-67 uptake in sarcoidosis

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

Bourguet, P.; Delaval, P.; Herry, J.Y.

1986-10-01

A method of direct quantitation of /sup 67/Ga uptake in the lung is described. The attenuation coefficient requires calculation and is obtained simply for each patient by transmission using a planar radionuclide source. The validity of the method was tested with a phantom (error less than 10%). Forty-three patients with pulmonary and/or mediastinal sarcoidosis were classified. The different groups of patients as defined clinically and radiographically (controls, nonactive, and active sarcoidosis) were well-differentiated (p less than 0.001).

Dynamical analysis of surface-insulated planar wire array Z-pinches

NASA Astrophysics Data System (ADS)

Li, Yang; Sheng, Liang; Hei, Dongwei; Li, Xingwen; Zhang, Jinhai; Li, Mo; Qiu, Aici

2018-05-01

The ablation and implosion dynamics of planar wire array Z-pinches with and without surface insulation are compared and discussed in this paper. This paper first presents a phenomenological model named the ablation and cascade snowplow implosion (ACSI) model, which accounts for the ablation and implosion phases of a planar wire array Z-pinch in a single simulation. The comparison between experimental data and simulation results shows that the ACSI model could give a fairly good description about the dynamical characteristics of planar wire array Z-pinches. Surface insulation introduces notable differences in the ablation phase of planar wire array Z-pinches. The ablation phase is divided into two stages: insulation layer ablation and tungsten wire ablation. The two-stage ablation process of insulated wires is simulated in the ACSI model by updating the formulas describing the ablation process.

Hypersensitive Detection and Quantitation of BoNT/A by IgY Antibody against Substrate Linear-Peptide

PubMed Central

Li, Tao; Liu, Hao; Cai, Kun; Tian, Maoren; Wang, Qin; Shi, Jing; Gao, Xiang; Wang, Hui

2013-01-01

Botulinum neurotoxin A (BoNT/A), the most acutely poisonous substance to humans known, cleave its SNAP-25 substrate with high specificity. Based on the endopeptidase activity, different methods have been developed to detect BoNT/A, but most lack ideal reproducibility or sensitivity, or suffer from long-term or unwanted interferences. In this study, we developed a simple method to detect and quantitate trace amounts of botulinum neurotoxin A using the IgY antibody against a linear-peptide substrate. The effects of reaction buffer, time, and temperature were analyzed and optimized. When the optimized assay was used to detect BoNT/A, the limit of detection of the assay was 0.01 mouse LD50 (0.04 pg), and the limit of quantitation was 0.12 mouse LD50/ml (0.48 pg). The findings also showed favorable specificity of detecting BoNT/A. When used to detect BoNT/A in milk or human serum, the proposed assay exhibited good quantitative accuracy (88% < recovery < 111%; inter- and intra-assay CVs < 18%). This method of detection took less than 3 h to complete, indicating that it can be a valuable method of detecting BoNT/A in food or clinical diagnosis. PMID:23555605

Hypersensitive detection and quantitation of BoNT/A by IgY antibody against substrate linear-peptide.

PubMed

Li, Tao; Liu, Hao; Cai, Kun; Tian, Maoren; Wang, Qin; Shi, Jing; Gao, Xiang; Wang, Hui

2013-01-01

Botulinum neurotoxin A (BoNT/A), the most acutely poisonous substance to humans known, cleave its SNAP-25 substrate with high specificity. Based on the endopeptidase activity, different methods have been developed to detect BoNT/A, but most lack ideal reproducibility or sensitivity, or suffer from long-term or unwanted interferences. In this study, we developed a simple method to detect and quantitate trace amounts of botulinum neurotoxin A using the IgY antibody against a linear-peptide substrate. The effects of reaction buffer, time, and temperature were analyzed and optimized. When the optimized assay was used to detect BoNT/A, the limit of detection of the assay was 0.01 mouse LD50 (0.04 pg), and the limit of quantitation was 0.12 mouse LD50/ml (0.48 pg). The findings also showed favorable specificity of detecting BoNT/A. When used to detect BoNT/A in milk or human serum, the proposed assay exhibited good quantitative accuracy (88% < recovery < 111%; inter- and intra-assay CVs < 18%). This method of detection took less than 3 h to complete, indicating that it can be a valuable method of detecting BoNT/A in food or clinical diagnosis.

Anisotropic Magnus Force in Type-II Superconductors with Planar Defects

NASA Astrophysics Data System (ADS)

Monroy, Ricardo Vega; Gomez, Eliceo Cortés

2015-02-01

The effect of planar defects on the Magnus force in type-II superconductors is studied. It is shown that the deformation of the vortex due to the presence of a planar defect leads to a local decrease in the mean free path of electrons in the vortex. This effect reduces the effective Magnus coefficient in normal direction to the planar defect, leading to an anisotropic regime of the Hall effect. The presented developments here can qualitatively explain experimental observations of the anisotropic Hall effect in high- T c superconductors in the mixed state.

"Finite part" electric and magnetic stored energies for planar antennas

NASA Technical Reports Server (NTRS)

Cockrell, C. R.

1981-01-01

A pair of formulas representing the time-average "finite part" electric and magnetic stored energies for planar antennas are derived. It is also shown that the asymptotic reciprocal relationship between quality factor and relative bandwidth exists for planar antennas.

Quasi-planar elemental clusters in pair interactions approximation

NASA Astrophysics Data System (ADS)

Chkhartishvili, Levan

2016-01-01

The pair-interactions approximation, when applied to describe elemental clusters, only takes into account bonding between neighboring atoms. According to this approach, isomers of wrapped forms of 2D clusters - nanotubular and fullerene-like structures - and truly 3D clusters, are generally expected to be more stable than their quasi-planar counterparts. This is because quasi-planar clusters contain more peripheral atoms with dangling bonds and, correspondingly, fewer atoms with saturated bonds. However, the differences in coordination numbers between central and peripheral atoms lead to the polarization of bonds. The related corrections to the molar binding energy can make small, quasi-planar clusters more stable than their 2D wrapped allotropes and 3D isomers. The present work provides a general theoretical frame for studying the relative stability of small elemental clusters within the pair interactions approximation.

Multiple Optical Traps with a Single-Beam Optical Tweezer Utilizing Surface Micromachined Planar Curved Grating

NASA Astrophysics Data System (ADS)

Kuo, Ju-Nan; Chen, Kuan-Yu

2010-11-01

In this paper, we present a single-beam optical tweezer integrated with a planar curved diffraction grating for microbead manipulation. Various curvatures of the surface micromachined planar curved grating are systematically investigated. The planar curved grating was fabricated using multiuser micro-electro-mechanical-system (MEMS) processes (MUMPs). The angular separation and the number of diffracted orders were determined. Experimental results indicate that the diffraction patterns and curvature of the planar curved grating are closely related. As the curvature of the planar curved grating increases, the vertical diffraction angle increases, resulting in the strip patterns of the planar curved grating. A single-beam optical tweezer integrated with a planar curved diffraction grating was developed. We demonstrate a technique for creating multiple optical traps from a single laser beam using the developed planar curved grating. The strip patterns of the planar curved grating that resulted from diffraction were used to trap one row of polystyrene beads.

Isolated planar gyroscope with internal radial sensing and actuation

NASA Technical Reports Server (NTRS)

Challoner, A. Dorian (Inventor); Shcheglov, Kirill V. (Inventor)

2006-01-01

The present invention discloses an inertial sensor comprising a planar mechanical resonator with embedded sensing and actuation for substantially in-plane vibration and having a central rigid support for the resonator. At least one excitation or torquer electrode is disposed within an interior of the resonator to excite in-plane vibration of the resonator and at least one sensing or pickoff electrode is disposed within the interior of the resonator for sensing the motion of the excited resonator. In one embodiment, the planar resonator includes a plurality of slots in an annular pattern; in another embodiment, the planar mechanical resonator comprises four masses; each embodiment having a simple degenerate pair of in-plane vibration modes.

Application of holographic elements in displays and planar illuminators

NASA Astrophysics Data System (ADS)

Putilin, Andrew; Gustomiasov, Igor

2007-05-01

Holographic Optical Elements (HOE's) on planar waveguides can be used to design the planar optics for backlit units, color selectors or filters, lenses for virtual reality displays. The several schemes for HOE recording are proposed to obtain planar stereo backlit unit and private eye displays light source. It is shown in the paper that the specific light transformation grating permits to construct efficient backlit units for display holograms and LCD. Several schemes of reflection/transmission backlit units and scattering films based on holographic optical elements are also proposed. The performance of the waveguide HOE can be optimized using the parameters of recording scheme and etching parameters. The schemes of HOE application are discussed and some experimental results are shown.

Planar Supported Membranes with Mobile SNARE Proteins and Quantitative Fluorescence Microscopy Assays to Study Synaptic Vesicle Fusion

PubMed Central

Kiessling, Volker; Liang, Binyong; Kreutzberger, Alex J. B.; Tamm, Lukas K.

2017-01-01

Synaptic vesicle membrane fusion, the process by which neurotransmitter gets released at the presynaptic membrane is mediated by a complex interplay between proteins and lipids. The realization that the lipid bilayer is not just a passive environment where other molecular players like SNARE proteins act, but is itself actively involved in the process, makes the development of biochemical and biophysical assays particularly challenging. We summarize in vitro assays that use planar supported membranes and fluorescence microscopy to address some of the open questions regarding the molecular mechanisms of SNARE-mediated membrane fusion. Most of the assays discussed in this mini-review were developed in our lab over the last 15 years. We emphasize the sample requirements that we found are important for the successful application of these methods. PMID:28360838

Internal gain in Er-doped As₂S₃ chalcogenide planar waveguides.

PubMed

Yan, Kunlun; Vu, Khu; Madden, Steve

2015-03-01

Low-loss erbium-doped As₂S₃ planar waveguides are fabricated by cothermal evaporation and plasma etching. Internal gain in the telecommunications band is demonstrated for the first time in any chalcogenide glass and additionally in a thin film planar waveguide amplifier configuration.

Abdo-Man: a 3D-printed anthropomorphic phantom for validating quantitative SIRT.

PubMed

Gear, Jonathan I; Cummings, Craig; Craig, Allison J; Divoli, Antigoni; Long, Clive D C; Tapner, Michael; Flux, Glenn D

2016-12-01

The use of selective internal radiation therapy (SIRT) is rapidly increasing, and the need for quantification and dosimetry is becoming more widespread to facilitate treatment planning and verification. The aim of this project was to develop an anthropomorphic phantom that can be used as a validation tool for post-SIRT imaging and its application to dosimetry. The phantom design was based on anatomical data obtained from a T1-weighted volume-interpolated breath-hold examination (VIBE) on a Siemens Aera 1.5 T MRI scanner. The liver, lungs and abdominal trunk were segmented using the Hermes image processing workstation. Organ volumes were then uploaded to the Delft Visualization and Image processing Development Environment for smoothing and surface rendering. Triangular meshes defining the iso-surfaces were saved as stereo lithography (STL) files and imported into the Autodesk® Meshmixer software. Organ volumes were subtracted from the abdomen and a removable base designed to allow access to the liver cavity. Connection points for placing lesion inserts and filling holes were also included. The phantom was manufactured using a Stratasys Connex3 PolyJet 3D printer. The printer uses stereolithography technology combined with ink jet printing. Print material is a solid acrylic plastic, with similar properties to polymethylmethacrylate (PMMA). Measured Hounsfield units and calculated attenuation coefficients of the material were shown to also be similar to PMMA. Total print time for the phantom was approximately 5 days. Initial scans of the phantom have been performed with Y-90 bremsstrahlung SPECT/CT, Y-90 PET/CT and Tc-99m SPECT/CT. The CT component of these images compared well with the original anatomical reference, and measurements of volume agreed to within 9 %. Quantitative analysis of the phantom was performed using all three imaging techniques. Lesion and normal liver absorbed doses were calculated from the quantitative images in three dimensions using the

Arabidopsis AIP1-2 restricted by WER-mediated patterning modulates planar polarity

PubMed Central

Kiefer, Christian S.; Claes, Andrea R.; Nzayisenga, Jean-Claude; Pietra, Stefano; Stanislas, Thomas; Hüser, Anke; Ikeda, Yoshihisa; Grebe, Markus

2015-01-01

The coordination of cell polarity within the plane of the tissue layer (planar polarity) is crucial for the development of diverse multicellular organisms. Small Rac/Rho-family GTPases and the actin cytoskeleton contribute to planar polarity formation at sites of polarity establishment in animals and plants. Yet, upstream pathways coordinating planar polarity differ strikingly between kingdoms. In the root of Arabidopsis thaliana, a concentration gradient of the phytohormone auxin coordinates polar recruitment of Rho-of-plant (ROP) to sites of polar epidermal hair initiation. However, little is known about cytoskeletal components and interactions that contribute to this planar polarity or about their relation to the patterning machinery. Here, we show that ACTIN7 (ACT7) represents a main actin isoform required for planar polarity of root hair positioning, interacting with the negative modulator ACTIN-INTERACTING PROTEIN1-2 (AIP1-2). ACT7, AIP1-2 and their genetic interaction are required for coordinated planar polarity of ROP downstream of ethylene signalling. Strikingly, AIP1-2 displays hair cell file-enriched expression, restricted by WEREWOLF (WER)-dependent patterning and modified by ethylene and auxin action. Hence, our findings reveal AIP1-2, expressed under control of the WER-dependent patterning machinery and the ethylene signalling pathway, as a modulator of actin-mediated planar polarity. PMID:25428588

Arabidopsis AIP1-2 restricted by WER-mediated patterning modulates planar polarity.

PubMed

Kiefer, Christian S; Claes, Andrea R; Nzayisenga, Jean-Claude; Pietra, Stefano; Stanislas, Thomas; Hüser, Anke; Ikeda, Yoshihisa; Grebe, Markus

2015-01-01

The coordination of cell polarity within the plane of the tissue layer (planar polarity) is crucial for the development of diverse multicellular organisms. Small Rac/Rho-family GTPases and the actin cytoskeleton contribute to planar polarity formation at sites of polarity establishment in animals and plants. Yet, upstream pathways coordinating planar polarity differ strikingly between kingdoms. In the root of Arabidopsis thaliana, a concentration gradient of the phytohormone auxin coordinates polar recruitment of Rho-of-plant (ROP) to sites of polar epidermal hair initiation. However, little is known about cytoskeletal components and interactions that contribute to this planar polarity or about their relation to the patterning machinery. Here, we show that ACTIN7 (ACT7) represents a main actin isoform required for planar polarity of root hair positioning, interacting with the negative modulator ACTIN-INTERACTING PROTEIN1-2 (AIP1-2). ACT7, AIP1-2 and their genetic interaction are required for coordinated planar polarity of ROP downstream of ethylene signalling. Strikingly, AIP1-2 displays hair cell file-enriched expression, restricted by WEREWOLF (WER)-dependent patterning and modified by ethylene and auxin action. Hence, our findings reveal AIP1-2, expressed under control of the WER-dependent patterning machinery and the ethylene signalling pathway, as a modulator of actin-mediated planar polarity. © 2015. Published by The Company of Biologists Ltd.

Planar-type ferromagnetic tunnel junctions fabricated by SPM local oxidation

NASA Astrophysics Data System (ADS)

Tomoda, Y.; Kayashima, S.; Ogino, T.; Motoyama, M.; Takemura, Y.; Shirakashi, J.

Nanometer-scale oxide wires were fabricated by local oxidation nanolithography using scanning probe microscope (SPM). This technique was applied to the fabrication of planar-type Ni/Ni oxide/Ni ferromagnetic tunnel junctions. In order to induce magnetic shape anisotropy, asymmetrical channel structure was patterned by conventional photolithography and wet etching processes. The magnetoresistance (MR) characteristics were clearly shown in the planar-type Ni/Ni oxide/Ni ferromagnetic tunnel junctions. MR ratio of above 100% was obtained at 17 K. This result suggests that the local oxidation nanolithography using SPM is useful for the application to planar-type ferromagnetic tunnel junctions.

The precision seismometer based on planar electrochemical transducer

NASA Astrophysics Data System (ADS)

Shabalina, A. S.; Krishtop, V. G.

2016-12-01

In this paper we investigate the possibility of applying a planar electrochemical trancducer (ECT) as a sensing element for a precision seismometer with a high inertial mass. The precision seismometer based on simplest planar ECT was manufactured and tested. We investigated the amplitude-frequency and volt-ampere characteristics, self-noise level and the transducer's impedance frequency dependence. One of the key characteristics for the seismometer is the intrinsic noise level, this work focuses on the self-noise level.

Organic light-emitting diodes from homoleptic square planar complexes

DOEpatents

Omary, Mohammad A

2013-11-12

Homoleptic square planar complexes [M(N.LAMBDA.N).sub.2], wherein two identical N.LAMBDA.N bidentate anionic ligands are coordinated to the M(II) metal center, including bidentate square planar complexes of triazolates, possess optical and electrical properties that make them useful for a wide variety of optical and electrical devices and applications. In particular, the complexes are useful for obtaining white or monochromatic organic light-emitting diodes ("OLEDs"). Improved white organic light emitting diode ("WOLED") designs have improved efficacy and/or color stability at high brightness in single- or two-emitter white or monochrome OLEDs that utilize homoleptic square planar complexes, including bis[3,5-bis(2-pyridyl)-1,2,4-triazolato]platinum(II) ("Pt(ptp).sub.2").

Novel Planar and Integrated Microwave Antennas

NASA Technical Reports Server (NTRS)

Saed, Mohammad A.

2000-01-01

This project dealt with design, analysis, and testing of new types of planar and integrated antennas operating in the microwave frequency range. The following was accomplished during this project period:

A Planar Microfluidic Mixer Based on Logarithmic Spirals

PubMed Central

Scherr, Thomas; Quitadamo, Christian; Tesvich, Preston; Park, Daniel Sang-Won; Tiersch, Terrence; Hayes, Daniel; Choi, Jin-Woo; Nandakumar, Krishnaswamy

2013-01-01

A passive, planar micromixer design based on logarithmic spirals is presented. The device was fabricated using polydimethylsiloxane soft photolithography techniques, and mixing performance was characterized via numerical simulation and fluorescent microscopy. Mixing efficiency initially declined as Reynolds number increased, and this trend continued until a Reynolds number of 15 where a minimum was reached at 53%. Mixing efficiency then began to increase reaching a maximum mixing efficiency of 86% at Re = 67. Three-dimensional simulations of fluid mixing in this design were compared to other planar geometries such as the Archimedes spiral and Meandering-S mixers. The implementation of logarithmic curvature offers several unique advantages that enhance mixing, namely a variable cross-sectional area and a logarithmically varying radius of curvature that creates 3-D Dean vortices. These flow phenomena were observed in simulations with multilayered fluid folding and validated with confocal microscopy. This design provides improved mixing performance over a broader range of Reynolds numbers than other reported planar mixers, all while avoiding external force fields, more complicated fabrication processes, and the introduction of flow obstructions or cavities that may unintentionally affect sensitive or particulate-containing samples. Due to the planar design requiring only single-step lithographic features, this compact geometry could be easily implemented into existing micro-total analysis systems requiring effective rapid mixing. PMID:23956497

A planar microfluidic mixer based on logarithmic spirals

NASA Astrophysics Data System (ADS)

Scherr, Thomas; Quitadamo, Christian; Tesvich, Preston; Sang-Won Park, Daniel; Tiersch, Terrence; Hayes, Daniel; Choi, Jin-Woo; Nandakumar, Krishnaswamy; Monroe, W. Todd

2012-05-01

A passive, planar micromixer design based on logarithmic spirals is presented. The device was fabricated using polydimethylsiloxane soft photolithography techniques, and mixing performance was characterized via numerical simulation and fluorescent microscopy. Mixing efficiency initially declined as the Reynolds number increased, and this trend continued until a Reynolds number of 15 where a minimum was reached at 53%. Mixing efficiency then began to increase reaching a maximum mixing efficiency of 86% at Re = 67. Three-dimensional (3D) simulations of fluid mixing in this design were compared to other planar geometries such as the Archimedes spiral and Meandering-S mixers. The implementation of logarithmic curvature offers several unique advantages that enhance mixing, namely a variable cross-sectional area and a logarithmically varying radius of curvature that creates 3D Dean vortices. These flow phenomena were observed in simulations with multilayered fluid folding and validated with confocal microscopy. This design provides improved mixing performance over a broader range of Reynolds numbers than other reported planar mixers, all while avoiding external force fields, more complicated fabrication processes and the introduction of flow obstructions or cavities that may unintentionally affect sensitive or particulate-containing samples. Due to the planar design requiring only single-step lithographic features, this compact geometry could be easily implemented into existing micro-total analysis systems requiring effective rapid mixing.

Nonlinear Saturation Amplitude in Classical Planar Richtmyer-Meshkov Instability

NASA Astrophysics Data System (ADS)

Liu, Wan-Hai; Wang, Xiang; Jiang, Hong-Bin; Ma, Wen-Fang

2016-04-01

The classical planar Richtmyer-Meshkov instability (RMI) at a fluid interface supported by a constant pressure is investigated by a formal perturbation expansion up to the third order, and then according to definition of nonlinear saturation amplitude (NSA) in Rayleigh-Taylor instability (RTI), the NSA in planar RMI is obtained explicitly. It is found that the NSA in planar RMI is affected by the initial perturbation wavelength and the initial amplitude of the interface, while the effect of the initial amplitude of the interface on the NSA is less than that of the initial perturbation wavelength. Without marginal influence of the initial amplitude, the NSA increases linearly with wavelength. The NSA normalized by the wavelength in planar RMI is about 0.11, larger than that corresponding to RTI. Supported by the National Natural Science Foundation of China under Grant Nos. 11472278 and 11372330, the Scientific Research Foundation of Education Department of Sichuan Province under Grant No. 15ZA0296, the Scientific Research Foundation of Mianyang Normal University under Grant Nos. QD2014A009 and 2014A02, and the National High-Tech ICF Committee

Electrochemical impedance spectroscopy for quantitative interface state characterization of planar and nanostructured semiconductor-dielectric interfaces

NASA Astrophysics Data System (ADS)

Meng, Andrew C.; Tang, Kechao; Braun, Michael R.; Zhang, Liangliang; McIntyre, Paul C.

2017-10-01

The performance of nanostructured semiconductors is frequently limited by interface defects that trap electronic carriers. In particular, high aspect ratio geometries dramatically increase the difficulty of using typical solid-state electrical measurements (multifrequency capacitance- and conductance-voltage testing) to quantify interface trap densities (D it). We report on electrochemical impedance spectroscopy (EIS) to characterize the energy distribution of interface traps at metal oxide/semiconductor interfaces. This method takes advantage of liquid electrolytes, which provide conformal electrical contacts. Planar Al2O3/p-Si and Al2O3/p-Si0.55Ge0.45 interfaces are used to benchmark the EIS data against results obtained from standard electrical testing methods. We find that the solid state and EIS data agree very well, leading to the extraction of consistent D it energy distributions. Measurements carried out on pyramid-nanostructured p-Si obtained by KOH etching followed by deposition of a 10 nm ALD-Al2O3 demonstrate the application of EIS to trap characterization of a nanostructured dielectric/semiconductor interface. These results show the promise of this methodology to measure interface state densities for a broad range of semiconductor nanostructures such as nanowires, nanofins, and porous structures.

Far-infrared spectra of yttrium-doped gold clusters Au(n)Y (n=1-9).

PubMed

Lin, Ling; Claes, Pieterjan; Gruene, Philipp; Meijer, Gerard; Fielicke, André; Nguyen, Minh Tho; Lievens, Peter

2010-06-21

The geometric, spectroscopic, and electronic properties of neutral yttrium-doped gold clusters Au(n)Y (n=1-9) are studied by far-infrared multiple photon dissociation (FIR-MPD) spectroscopy and quantum chemical calculations. Comparison of the observed and calculated vibrational spectra allows the structures of the isomers present in the molecular beam to be determined. Most of the isomers for which the IR spectra agree best with experiment are calculated to be the energetically most stable ones. Attachment of xenon to the Au(n)Y cluster can cause changes in the IR spectra, which involve band shifts and band splittings. In some cases symmetry changes, as a result of the attachment of xenon atoms, were also observed. All the Au(n)Y clusters considered prefer a low spin state. In contrast to pure gold clusters, which exhibit exclusively planar lowest-energy structures for small sizes, several of the studied species are three-dimensional. This is particularly the case for Au(4)Y and Au(9)Y, while for some other sizes (n=5, 8) the 3D structures have an energy similar to that of their 2D counterparts. Several of the lowest-energy structures are quasi-2D, that is, slightly distorted from planar shapes. For all the studied species the Y atom prefers high coordination, which is different from other metal dopants in gold clusters.

Performance improvement of planar dielectric elastomer actuators by magnetic modulating mechanism

NASA Astrophysics Data System (ADS)

Zhao, Yun-Hua; Li, Wen-Bo; Zhang, Wen-Ming; Yan, Han; Peng, Zhi-Ke; Meng, Guang

2018-06-01

In this paper, a novel planar dielectric elastomer actuator (DEA) with magnetic modulating mechanism is proposed. This design can provide the availability of wider actuation range and larger output force, which are significant indicators to evaluate the performance of DEAs. The DEA tends to be a compact and simple design, and an analytical model is developed to characterize the mechanical behavior. The result shows that the output force induced by the DEA can be improved by 76.90% under a certain applied voltage and initial magnet distance. Moreover, experiments are carried out to reveal the performance of the proposed DEA and validate the theoretical model. It demonstrates that the DEA using magnetic modulating mechanism can enlarge the actuation range and has more remarkable effect with decreasing initial magnet distance within the stable range. It can be useful to promote the applications of DEAs to soft robots and haptic feedback.

Current Role of Selective Internal Irradiation With Yttrium-90 Microspheres in the Management of Hepatocellular Carcinoma: A Systematic Review

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

Lau, Wan Yee, E-mail: josephlau@cuhk.edu.hk; Lai, Eric C.H.; Leung, Thomas W.T.

2011-10-01

Purpose: This article reviews the role of selective internal irradiation (SIR) with yttrium-90 ({sup 90}Y) microspheres for hepatocellular carcinoma (HCC). Methods and Materials: Studies were identified by searching Medline and PubMed databases for articles from 1990 to 2009 using the keywords 'selective internal irradiation,' 'hepatocellular carcinoma,' 'therapeutic embolization,' and 'yttrium-90.' Results: {sup 90}Y microspheres are a safe and well-tolerated therapy for unresectable HCC (median survival range, 7 -21.6 months). The evidence was limited to cohort studies and comparative studies with historical control. {sup 90}Y microspheres have been reported to downstage unresectable HCC to allow for salvage treatments with curative intent,more » act as a bridging therapy before liver transplantation, and treat HCC with curative intent for patients who are not surgical candidates because of comorbidities. Conclusions: {sup 90}Y microsphere is recommended as an option of palliative therapy for large or multifocal HCC without major portal vein invasion or extrahepatic spread. It can also be used for recurrent unresectable HCC, as a bridging therapy before liver transplantation, as a tumor downstaging treatment, and as a curative treatment for patients with associated comorbidities who are not candidates for surgery.« less

On designing low pressure loss working spaces for a planar Stirling micromachine

NASA Astrophysics Data System (ADS)

Hachey, M.-A.; Léveillé, É.; Fréchette, L. G.; Formosa, F.

2015-12-01

In this paper, research was undertaken with the objective to design low pressure loss working spaces for a Stirling cycle micro heat engine operating from low temperature waste heat. This planar free-piston heat engine is anticipated to operate at the kHz level with mm3 displacement. Given the resonant nature of the free-piston configuration, the complexity of its working gas’ flow geometry and its projected high operating frequency, flow analysis is relatively complex. Design considerations were thus based on fast prototyping and experimentation. Results show that geometrical features, such as a sharp 90° corner between the regenerator and working spaces, are strong contributors to pressure losses. This research culminated into a promising revised working space configuration for engine start-up, as it considerably reduced total pressure losses, more than 80% at Re = 700, from the original design.

The growth rate of vertex-transitive planar graphs

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

Babai, L.

1997-06-01

A graph is vertex-transitive if all of its vertices axe equivalent under automorphisms. Confirming a conjecture of Jon Kleinberg and Eva Tardos, we prove the following trichotomy theorem concerning locally finite vertex-transitive planar graphs: the rate of growth of a graph with these properties is either linear or quadratic or exponential. The same result holds more generally for locally finite, almost vertex-transitive planar graphs (the automorphism group has a finite number of orbits). The proof uses the elements of hyperbolic plane geometry.

Recent progress in design and hybridization of planar grating-based transceivers

NASA Astrophysics Data System (ADS)

Bidnyk, S.; Pearson, M.; Balakrishnan, A.; Gao, M.

2007-06-01

We report on recent progress in simulations, physical layout, fabrication and hybridization of planar grating-based transceivers for passive optical networks (PONs). Until recently, PON transceivers have been manufactured using bulk micro-optical components. Today, advancements in modeling and simulation techniques has made it possible to design complex elements in the same silica-on silicon PLC platform and create an alternative platform for manufacturing of bi-directional transceivers. In our chips we simulated an integrated chip that monolithically combined planar reflective gratings and cascaded Mach-Zehnder interferometers. We used a combination of the finite element method and beam propagation method to model cascaded interferometers with enhanced coupling coefficients. Our simulations show that low-diffraction order planar reflective gratings, designed for small incidence and reflection angles, possess the required dispersion strength to meet the PON specifications. Subsequently, we created structures for passive alignment and hybridized photodetectors and lasers. We believe that advancements in simulation of planar lightwave circuits with embedded planar reflective gratings will result in displacement of the thin-film filters (TFFs) technology in many applications that require a high degree of monolithic and hybrid integration.

Paving the Way Towards Reactive Planar Spanner Construction in Wireless Networks

NASA Astrophysics Data System (ADS)

Frey, Hannes; Rührup, Stefan

A spanner is a subgraph of a given graph that supports the original graph's shortest path lengths up to a constant factor. Planar spanners and their distributed construction are of particular interest for geographic routing, which is an efficient localized routing scheme for wireless ad hoc and sensor networks. Planarity of the network graph is a key criterion for guaranteed delivery, while the spanner property supports efficiency in terms of path length. We consider the problem of reactive local spanner construction, where a node's local topology is determined on demand. Known message-efficient reactive planarization algorithms do not preserve the spanner property, while reactive spanner constructions with a low message overhead have not been described so far. We introduce the concept of direct planarization which may be an enabler of efficient reactive spanner construction. Given an edge, nodes check for all incident intersecting edges a certain geometric criterion and withdraw the edge if this criterion is not satisfied. We use this concept to derive a generic reactive topology control mechanism and consider two geometric criteria. Simulation results show that direct planarization increases the performance of localized geographic routing by providing shorter paths than existing reactive approaches.

Planar multijunction high voltage solar cells

NASA Technical Reports Server (NTRS)

Evans, J. C., Jr.; Chai, A. T.; Goradia, C.

1980-01-01

Technical considerations, preliminary results, and fabrication details are discussed for a family of high-voltage planar multi-junction (PMJ) solar cells which combine the attractive features of planar cells with conventional or interdigitated back contacts and the vertical multijunction (VMJ) solar cell. The PMJ solar cell is internally divided into many voltage-generating regions, called unit cells, which are internally connected in series. The key to obtaining reasonable performance from this device was the separation of top surface field regions over each active unit cell. Using existing solar cell fabricating methods, output voltages in excess of 20 volts per linear centimeter are possible. Analysis of the new device is complex, and numerous geometries are being studied which should provide substantial benefits in both normal sunlight usage as well as with concentrators.

Planar regions of GaAs (001) prepared by Ga droplet motion

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

Zheng, Changxi, E-mail: changxi.zheng@monash.edu; Tang, Wen-Xin; Jesson, David E., E-mail: jessonDE@cardiff.ac.uk

2016-07-15

The authors describe a simple method for obtaining planar regions of GaAs (001) suitable for surface science studies. The technique, which requires no buffer layer growth, atomic hydrogen source, or the introduction of As flux, employs controllable Ga droplet motion to create planar trail regions during Langmuir evaporation. Low-energy electron microscopy/diffraction techniques are applied to monitor the droplet motion and characterize the morphology and the surface reconstruction. It is found that the planar regions exhibit atomic flatness at the level of a high-quality buffer layer.

Negative refraction and planar focusing based on parity-time symmetric metasurfaces.

PubMed

Fleury, Romain; Sounas, Dimitrios L; Alù, Andrea

2014-07-11

We introduce a new mechanism to realize negative refraction and planar focusing using a pair of parity-time symmetric metasurfaces. In contrast to existing solutions that achieve these effects with negative-index metamaterials or phase conjugating surfaces, the proposed parity-time symmetric lens enables loss-free, all-angle negative refraction and planar focusing in free space, without relying on bulk metamaterials or nonlinear effects. This concept may represent a pivotal step towards loss-free negative refraction and highly efficient planar focusing by exploiting the largely uncharted scattering properties of parity-time symmetric systems.

Planar and non-planar nucleus-acoustic shock structures in self-gravitating degenerate quantum plasma systems

NASA Astrophysics Data System (ADS)

Zaman, D. M. S.; Amina, M.; Dip, P. R.; Mamun, A. A.

2017-11-01

The basic properties of planar and non-planar (spherical and cylindrical) nucleus-acoustic (NA) shock structures (SSs) in a strongly coupled self-gravitating degenerate quantum plasma system (containing strongly coupled non-relativistically degenerate heavy nuclear species, weakly coupled non-relativistically degenerate light nuclear species, and inertialess non-/ultra-relativistically degenerate electrons) have been investigated. The generalized quantum hydrodynamic model and the reductive perturbation method have been used to derive the modified Burgers equation. It is shown that the strong correlation among heavy nuclear species acts as the source of dissipation and is responsible for the formation of the NA SSs with positive (negative) electrostatic (self-gravitational) potential. It is also observed that the effects of non-/ultra-relativistically degenerate electron pressure, dynamics of non-relativistically degenerate light nuclear species, spherical geometry, etc., significantly modify the basic features of the NA SSs. The applications of our results in astrophysical compact objects like white dwarfs and neutron stars are briefly discussed.

Deterministic switching of hierarchy during wrinkling in quasi-planar bilayers

DOE PAGES

Saha, Sourabh K.; Culpepper, Martin L.

2016-04-25

Emergence of hierarchy during compression of quasi-planar bilayers is preceded by a mode-locked state during which the quasi-planar form persists. Transition to hierarchy is determined entirely by geometrically observable parameters. This results in a universal transition phase diagram that enables one to deterministically tune hierarchy even with limited knowledge about material properties.

Conservation of Planar Polarity Pathway Function Across the Animal Kingdom.

PubMed

Hale, Rosalind; Strutt, David

2015-01-01

Planar polarity is a well-studied phenomenon resulting in the directional coordination of cells in the plane of a tissue. In invertebrates and vertebrates, planar polarity is established and maintained by the largely independent core and Fat/Dachsous/Four-jointed (Ft-Ds-Fj) pathways. Loss of function of these pathways can result in a wide range of developmental or cellular defects, including failure of gastrulation and problems with placement and function of cilia. This review discusses the conservation of these pathways across the animal kingdom. The lack of vital core pathway components in basal metazoans suggests that the core planar polarity pathway evolved shortly after, but not necessarily alongside, the emergence of multicellularity.

Spin Vortex Resonance in Non-planar Ferromagnetic Dots

DOE PAGES

Ding, Junjia; Lapa, Pavel; Jain, Shikha; ...

2016-05-04

In planar structures, the vortex resonance frequency changes little as a function of an in-plane magnetic field as long as the vortex state persists. Altering the topography of the element leads to a vastly different dynamic response that arises due to the local vortex core confinement effect. In this work, we studied the magnetic excitations in non-planar ferromagnetic dots using a broadband microwave spectroscopy technique. Two distinct regimes of vortex gyration were detected depending on the vortex core position. The experimental results are in qualitative agreement with micromagnetic simulations.

Study of influence of plastic scintillators thicknesses to detect Beta particles and Gamma radiation by means of spectral analysis of {sup 90}Sr, {sup 90}Y and {sup 137}Cs sources

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

Cardenas, Jose Patricio Nahuel; Filho, Tufic Madi; Pereira, Maria da Conceicao Costa

2015-07-01

The Nuclear and Energy Research Institute - IPEN, offers post-graduate programs, namely: Nuclear Technology - Applications (TNA), Nuclear Technology - Materials (TNM), Nuclear Technology - Reactors (TNR). The Institute programs mission is to form expert technicians, physicists and engineers with a strong knowledge in their discipline to work in the nuclear area. The course: 'Theoretical Fundamentals and Practices of the Instrumentation used in Nuclear Data Acquisition' covers the use of laboratory nuclear instrumentation and the accomplishment of experiments to obtain nuclear parameters. One of these experimental exercises is object of this work: 'Study of influence of plastic scintillators to detectmore » Beta particles and Gamma radiation by means of spectral analysis of {sup 90}Sr, {sup 90}Y and {sup 137}Cs sources'. The use of scintillators plastic for the detection has the advantage of low cost, high mechanical strength, is not hygroscopic and can be manufactured in large volumes. This work aims to present the analysis of relative efficiency of detection of plastic scintillators of various thicknesses for beta particles and gamma radiation by the spectrum of {sup 137}Cs and {sup 90}Sr. Due to lack of resolution of the detectors plastic scintillators we worked with relative efficiency. The evaluation was done by reading deposited energy, using the software MAESTRO, for each detector thickness. For beta particles was observed an ideal thickness around 3 mm and the better photon efficiency was observed with increasing the thickness of the detector. The present experiment does not intend to establish a new technique for this subject: it solely aims student's practical exercises in nuclear properties of elements and detectors being part of the nuclear experimental course. (authors)« less

Reflected wavefront manipulation based on ultrathin planar acoustic metasurfaces

PubMed Central

Li, Yong; Liang, Bin; Gu, Zhong-ming; Zou, Xin-ye; Cheng, Jian-chun

2013-01-01

The introduction of metasurfaces has renewed the Snell's law and opened up new degrees of freedom to tailor the optical wavefront at will. Here, we theoretically demonstrate that the generalized Snell's law can be achieved for reflected acoustic waves based on ultrathin planar acoustic metasurfaces. The metasurfaces are constructed with eight units of a solid structure to provide discrete phase shifts covering the full 2π span with steps of π/4 by coiling up the space. By careful selection of the phase profiles in the transverse direction of the metasurfaces, some fascinating wavefront engineering phenomena are demonstrated, such as anomalous reflections, conversion of propagating waves into surface waves, planar aberration-free lens and nondiffracting Bessel beam generated by planar acoustic axicon. Our results could open up a new avenue for acoustic wavefront engineering and manipulations. PMID:23986034

Growth and characterization of textured well-faceted ZnO on planar Si(100), planar Si(111), and textured Si(100) substrates for solar cell applications.

PubMed

Tsai, Chin-Yi; Lai, Jyong-Di; Feng, Shih-Wei; Huang, Chien-Jung; Chen, Chien-Hsun; Yang, Fann-Wei; Wang, Hsiang-Chen; Tu, Li-Wei

2017-01-01

In this work, textured, well-faceted ZnO materials grown on planar Si(100), planar Si(111), and textured Si(100) substrates by low-pressure chemical vapor deposition (LPCVD) were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and cathode luminescence (CL) measurements. The results show that ZnO grown on planar Si(100), planar Si(111), and textured Si(100) substrates favor the growth of ZnO(110) ridge-like, ZnO(002) pyramid-like, and ZnO(101) pyramidal-tip structures, respectively. This could be attributed to the constraints of the lattice mismatch between the ZnO and Si unit cells. The average grain size of ZnO on the planar Si(100) substrate is slightly larger than that on the planar Si(111) substrate, while both of them are much larger than that on the textured Si(100) substrate. The average grain sizes (about 10-50 nm) of the ZnO grown on the different silicon substrates decreases with the increase of their strains. These results are shown to strongly correlate with the results from the SEM, AFM, and CL as well. The reflectance spectra of these three samples show that the antireflection function provided by theses samples mostly results from the nanometer-scaled texture of the ZnO films, while the micrometer-scaled texture of the Si substrate has a limited contribution. The results of this work provide important information for optimized growth of textured and well-faceted ZnO grown on wafer-based silicon solar cells and can be utilized for efficiency enhancement and optimization of device materials and structures, such as heterojunction with intrinsic thin layer (HIT) solar cells.

Detection of Sentinel Lymph Nodes in Gynecologic Tumours by Planar Scintigraphy and SPECT/CT

PubMed Central

Kraft, Otakar; Havel, Martin

2012-01-01

Objective: Assess the role of planar lymphoscintigraphy and fusion imaging of SPECT/CT in sentinel lymph node (SLN) detection in patients with gynecologic tumours. Material and Methods: Planar scintigraphy and hybrid modality SPECT/CT were performed in 64 consecutive women with gynecologic tumours (mean age 53.6 with range 30-77 years): 36 pts with cervical cancer (Group A), 21 pts with endometrial cancer (Group B), 7 pts with vulvar carcinoma (Group C). Planar and SPECT/CT images were interpreted separately by two nuclear medicine physicians. Efficacy of these two techniques to image SLN were compared. Results: Planar scintigraphy did not image SLN in 7 patients (10.9%), SPECT/CT was negative in 4 patients (6.3%). In 35 (54.7%) patients the number of SLNs captured on SPECT/CT was higher than on planar imaging. Differences in detection of SLN between planar and SPECT/CT imaging in the group of all 64 patients are statistically significant (p<0.05). Three foci of uptake (1.7% from totally visible 177 foci on planar images) in 2 patients interpreted on planar images as hot LNs were found to be false positive non-nodal sites of uptake when further assessed on SPECT/CT. SPECT/CT showed the exact anatomical location of all visualised sentinel nodes. Conclusion: In some patients with gynecologic cancers SPECT/CT improves detection of sentinel lymph nodes. It can image nodes not visible on planar scintigrams, exclude false positive uptake and exactly localise pelvic and paraaortal SLNs. It improves anatomic localization of SLNs. Conflict of interest:None declared. PMID:23486989

Mode structure of planar optical antennas on dielectric substrates

DOE PAGES

Word, Robert C.; Konenkamp, Rolf

2016-08-08

Here, we report a numerical study, supported by photoemission electron microscopy (PEEM), of sub-micron planar optical antennas on transparent substrate. We find these antennas generate intricate near-field spatial field distributions with odd and even numbers of nodes. We show that the field distributions are primarily superpositions of planar surface plasmon polariton modes confined to the metal/substrate interface. The mode structure provides opportunities for coherent switching and optical control in sub-micron volumes.

Lithographically-Scribed Planar Holographic Optical CDMA Devices and Systems

DTIC Science & Technology

2007-02-15

operate with quite high refractive index contrast (order 0.5). Thin -filn filter devices are viewed as relatively low in chromatic dispersion. We have...stack consists of planar interfaces between materials of refractive index n, and n,. Let An = In2 - nil and n = (n, - n1)/2. The planar interfaces are... index ). It may be desirable to have a relatively large refractive index differential when diffractive elements are formed from cladding material at a

SU-F-T-301: Planar Dose Pass Rate Inflation Due to the MapCHECK Measurement Uncertainty Function

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

Bailey, D; Spaans, J; Kumaraswamy, L

Purpose: To quantify the effect of the Measurement Uncertainty function on planar dosimetry pass rates, as analyzed with Sun Nuclear Corporation analytic software (“MapCHECK” or “SNC Patient”). This optional function is toggled on by default upon software installation, and automatically increases the user-defined dose percent difference (%Diff) tolerance for each planar dose comparison. Methods: Dose planes from 109 IMRT fields and 40 VMAT arcs were measured with the MapCHECK 2 diode array, and compared to calculated planes from a commercial treatment planning system. Pass rates were calculated within the SNC analytic software using varying calculation parameters, including Measurement Uncertainty onmore » and off. By varying the %Diff criterion for each dose comparison performed with Measurement Uncertainty turned off, an effective %Diff criterion was defined for each field/arc corresponding to the pass rate achieved with MapCHECK Uncertainty turned on. Results: For 3%/3mm analysis, the Measurement Uncertainty function increases the user-defined %Diff by 0.8–1.1% average, depending on plan type and calculation technique, for an average pass rate increase of 1.0–3.5% (maximum +8.7%). For 2%, 2 mm analysis, the Measurement Uncertainty function increases the user-defined %Diff by 0.7–1.2% average, for an average pass rate increase of 3.5–8.1% (maximum +14.2%). The largest increases in pass rate are generally seen with poorly-matched planar dose comparisons; the MapCHECK Uncertainty effect is markedly smaller as pass rates approach 100%. Conclusion: The Measurement Uncertainty function may substantially inflate planar dose comparison pass rates for typical IMRT and VMAT planes. The types of uncertainties incorporated into the function (and their associated quantitative estimates) as described in the software user’s manual may not accurately estimate realistic measurement uncertainty for the user’s measurement conditions. Pass rates listed in

Quantitation of intracellular metabolites of [35S]-6-mercaptopurine in L5178Y cells grown in time-course incubates.

PubMed

Breter, H J; Zahn, R K

1979-09-01

6-Mercaptopurine (6MP) metabolism was quantitatively determined in L5178Y murine lymphoma. Cells grown in time-course incubates with [35S]-6MP were extracted with cold perchloric acid, and the buffered extracts were subjected to high-performance liquid cation-exchange chromatography prior to and after hydrolysis with alkaline phosphatase. Free sulfate, 6-thiouric acid, 6-thioxanthosine, 6-thioguanosine, 6-thioinosine, free 6MP, and 6-methylthioinosine were separated from each other; identified in the radiochromatograms by elution volume, UV spectroscopic data, and enzymatic peak-shifting analyses with purine nucleoside phosphorylase; and quantitatively determined by means of 35S radioactivity. Gross intracellular 35S concentrations remained constant at 5 x 10(-5) M after 1 hr of incubation. 6MP metabolism in L5178Y cells was distinguished into an early phase (to 1 hr of incubation) in which 6MP was predominantly catabolized to 6-thiouric acid and free sulfate, into an intermediate phase (to 8 hr) in which substantial amounts of free 6MP and of ribonucleotides of 6-thioxanthosine and 6-thioguanosine were present while the concentrations of nonnucleotide oxidation products sharply decreased, and into a late phase (to 24 hr) in which the ribonucleotides of 6MP, of 6-thioguanosine and, in particular, of 6-methylthioinosine were the most abundant metabolites.

Comparison Of Planar And Wound Transformers For Flyback Forward And Half-Bridge Space Power Converters

NASA Astrophysics Data System (ADS)

Bjorklund, Thomas; Andreasen, John; Brosen, Finn; Matthiesen, Erik; Poulsen, Ole

2011-10-01

Planar technology has now entered the space domain. The big advantages of planar technology are; - Low profile - Excellent repeatability - Economical assembly - Mechanical integrity - Superior thermal characteristics This is why the general power industries increasingly are using planar magnetics in more and more applications, and therefore also why we see a rising demand for the usability of the planar technology among space application developers. The differences between wound and planar transformers have been mapped with a detailed look on the various parasitic component values, such as DC- and AC- resistance, Leakage Inductance and stray capacitance, and revealed the magnitude of the advantages of planar technology. This technical solution is proven in prototypes that have been built in different combination of PCB's and copper foil, with more or less interleaving of windings. Furthermore the transformers have been designed with several outputs stacked together with a fairly high number of primary turns, in order to have planar transformers similar to the wound types that are generally used for space applications.

Observing planar cell polarity in multiciliated mouse airway epithelial cells.

PubMed

Vladar, Eszter K; Lee, Yin Loon; Stearns, Tim; Axelrod, Jeffrey D

2015-01-01

The concerted movement of cilia propels inhaled contaminants out of the lungs, safeguarding the respiratory system from toxins, pathogens, pollutants, and allergens. Motile cilia on the multiciliated cells (MCCs) of the airway epithelium are physically oriented along the tissue axis for directional motility, which depends on the planar cell polarity (PCP) signaling pathway. The MCCs of the mouse respiratory epithelium have emerged as an important model for the study of motile ciliogenesis and the PCP signaling mechanism. Unlike other motile ciliated or planar polarized tissues, airway epithelial cells are relatively easily accessible and primary cultures faithfully model many of the essential features of the in vivo tissue. There is growing interest in understanding how cells acquire and polarize motile cilia due to the impact of mucociliary clearance on respiratory health. Here, we present methods for observing and quantifying the planar polarized orientation of motile cilia both in vivo and in primary culture airway epithelial cells. We describe how to acquire and evaluate electron and light microscopy images of ciliary ultrastructural features that reveal planar polarized orientation. Furthermore, we describe the immunofluorescence localization of PCP pathway components as a simple readout for airway epithelial planar polarization and ciliary orientation. These methods can be adapted to observe ciliary orientation in other multi- and monociliated cells and to detect PCP pathway activity in any tissue or cell type. Copyright © 2015 Elsevier Inc. All rights reserved.

Quantitative comparison of inflammatory infiltrate and linear contraction in human skin treated with 90-microsecond pulsed and 900-microsecond dwell time carbon dioxide lasers.

PubMed

Bucalo, B D; Moy, R L

1998-12-01

Skin resurfacing with 90-microsecond pulse duration carbon dioxide (CO2) resurfacing lasers has been reported to have shorter duration of erythema compared with skin resurfacing with 900-microsecond dwell time lasers. The presence of inflammatory infiltrate following resurfacing may correlate with the persistence of this erythema. Furthermore, skin treated with the 90-microsecond pulse duration laser and the 900-microsecond dwell time lasers both result in equivalent improvement of rhytids in the treated skin. To quantitative the inflammatory cell infiltrate and linear contraction of skin treated with the 90-microsecond pulsed and 900-microsecond dwell time CO2 lasers at intervals of 2 and 4 weeks after treatment. Volunteers were recruited from patients who were planning to undergo full face laser resurfacing under general anesthesia. Informed consent was obtained from all volunteers. In the posterior auricular areas of all volunteers, four separate rectangular areas were marked using a skin marking pen and a template. Two rectangular areas behind the right ear were treated with 6 passes of the 90-microsecond laser and two rectangular areas behind the left ear were treated with the 900-microsecond dwell time laser. The resurfaced areas were wiped with a moist cotton swab and then patted dry with dry gauze between passes. Contraction measurements of the resurfaced areas were taken before and immediately after laser treatment and again at 2 and 4 weeks following treatment. Punch biopsies were also performed at 2 and 4 weeks after treatment in an area of skin different from where contraction measurements were taken. The number of inflammatory cells present in the skin at 2 and 4 weeks after laser resurfacing are greater for skin resurfaced with a 900-microsecond dwell time laser than a 90-microsecond pulse time laser. Linear contraction of skin immediately after treatment was 18% greater with the 900-microsecond dwell time laser than with the 90-microsecond pulsed

Strontium-90 concentration measurements in human bones and teeth in Greece.

PubMed

Stamoulis, K C; Assimakopoulos, P A; Ioannides, K G; Johnson, E; Soucacos, P N

1999-05-19

Strontium-90 concentration was measured in human bones and teeth collected in Greece during the period 1992-1996. One hundred and five bone samples, mainly cancellous bone, and 108 samples, taken from a total of 896 individual teeth were processed. Samples were classified according to the age and sex of the donors. Samples were chemically pre-treated according to a specially devised method to enable extraction of 90Y, at equilibrium with 90Sr in the original sample. Subsequently, 90Y beta activity was measured with a gas proportional counter. Radiostrontium concentration in bone samples showed small variations with respect to age or sex, with an average value of 30 mBq 90Sr/g Ca. However, 90Sr concentration measurements in teeth demonstrated a pronounced structure, which clearly reflects contamination from the 1960s atmospheric nuclear weapons tests and the more recent Chernobyl accident. This difference is attributed to the different histological structure of skeletal bones and teeth, the later consisting mainly of compact bone. An age-dependent model for radiostrontium concentration in human bones and teeth is developed which is able to successfully reproduce the experimental data. Through a fitting process, the model also yielded calcium turnover rates for compact bone, as a function of age, as well as an estimate of radiostrontium contamination of foodstuffs in Greece for the past four decades. The results obtained in this study indicate that radiostrontium environmental contamination which resulted from the atmospheric nuclear weapons tests in the 1960s, exceed by far that caused by the Chernobyl accident.

Cloning of HSP90, expression and localization of HSP70/90 in different tissues including lactating/non-lactating yak (Bos grunniens) breast tissue.

PubMed

Liu, Penggang; Yu, Sijiu; Cui, Yan; He, Junfeng; Yu, Chuan; Wen, Zexing; Pan, Yangyang; Yang, Kun; Song, Liangli; Yang, Xue

2017-01-01

The aim of this study is to investigate the expression and localization of HSP70/90 in different tissues and explore the regulation effects of HSP70/90 at lactation period of female yaks. HSP90 mRNA was cloned from the heart samples of female yaks, Quantitative real-time (qRT-PCR), Western blotting (WB), immunohistochemistry and immunofluorescence assays were utilized to analyze the expressions of HSP70/90 mRNA and protein in different tissues. Sequence analysis showed that HSP90 is a conserved molecular chaperone of female yaks. The qRT-PCR, WB results showed that the expressions of HSP70/90 mRNA and protein were significantly different in different tissues, and 3-fold higher expression during the lactation period than the non-lactation period of breast tissue (P < 0.01). Immunohistochemistry and immunofluorescence assays results showed that HSP70/90 were located in the cardiac muscle cells, cerebellar medulla, theca cells lining at the reproductive system, and the mammary epithelia of the breasts. In addition, the expression level of HSP70 was higher than those of HSP90 in all examined tissues. Therefore, our results strongly suggest that the expression and localization of HSP70/90 could provide significant evidence to further research in tissue specific expression, and lactation function of female yaks.

Global geometry of non-planar 3-body motions

NASA Astrophysics Data System (ADS)

Salehani, Mahdi Khajeh

2011-12-01

The aim of this paper is to study the global geometry of non-planar 3-body motions in the realms of equivariant Differential Geometry and Geometric Mechanics. This work was intended as an attempt at bringing together these two areas, in which geometric methods play the major role, in the study of the 3-body problem. It is shown that the Euler equations of a three-body system with non-planar motion introduce non-holonomic constraints into the Lagrangian formulation of mechanics. Applying the method of undetermined Lagrange multipliers to study the dynamics of three-body motions reduced to the level of moduli space {bar{M}} subject to the non-holonomic constraints yields the generalized Euler-Lagrange equations of non-planar three-body motions in {bar{M}} . As an application of the derived dynamical equations in the level of {bar{M}} , we completely settle the question posed by A. Wintner in his book [The analytical foundations of Celestial Mechanics, Sections 394-396, 435 and 436. Princeton University Press (1941)] on classifying the constant inclination solutions of the three-body problem.

Helical axis stellarator with noninterlocking planar coils

DOEpatents

Reiman, Allan; Boozer, Allen H.

1987-01-01

A helical axis stellarator using only noninterlocking planar, non-circular coils, generates magnetic fields having a magnetic well and large rotational transform with resultant large equilibrium beta.

Cytokines and 90Y-Radioembolization: Relation to Liver Function and Overall Survival.

PubMed

Seidensticker, Max; Powerski, Maciej; Seidensticker, Ricarda; Damm, Robert; Mohnike, Konrad; Garlipp, Benjamin; Klopffleisch, Maurice; Amthauer, Holger; Ricke, Jens; Pech, Maciej

2017-08-01

To evaluate the course of pro- and anti-inflammatory cytokines after 90 Y-radioembolization (RE) of liver malignancies and to identify prognosticators for liver-related adverse events and survival. In 34 consecutive patients with secondary or primary liver tumors scheduled for RE, the following cytokines were measured prior to and 2 h, 3 days, and 6 weeks after RE: interleukin (IL) -1, IL-2, IL-4, IL-6, IL-8, tumor necrosis factor alpha (TNF-α), and interferon-γ. Liver function impairment was defined as an elevation of liver-related laboratory values as graded by CTCAE ≥ 2 and/or serum bilirubin ≥30 µmol/l and/or development of ascites at 6-week follow-up. Significant changes over time were seen in IL-1 (increase from 0.4 pg/ml (±0.7) at baseline to 1.1 pg/ml (±1.4) 3 days after RE (p = 0.02)), and in IL-6 (increase from 16.8 pg/ml (±21.8) at baseline to 54.6 pg/ml (±78.2) 3 days after RE (p = 0.003)). Baseline values of IL-6 and IL-8 were independently associated with liver function impairment at follow-up as well as decreased survival with an optimal cutoff at 6.53 and 60.8 pg/ml, respectively. Expected changes in pro- and anti-inflammatory cytokines after RE were shown. Furthermore, baseline values of IL-6 and IL-8 were associated with later liver dysfunction and survival. We hypothesize that these biomarkers are potential prognosticators and might help in patient selection for RE.

Three sets of crystallographic sub-planar structures in quartz formed by tectonic deformation

NASA Astrophysics Data System (ADS)

Derez, Tine; Pennock, Gill; Drury, Martyn; Sintubin, Manuel

2016-05-01

In quartz, multiple sets of fine planar deformation microstructures that have specific crystallographic orientations parallel to planes with low Miller-Bravais indices are commonly considered as shock-induced planar deformation features (PDFs) diagnostic of shock metamorphism. Using polarized light microscopy, we demonstrate that up to three sets of tectonically induced sub-planar fine extinction bands (FEBs), sub-parallel to the basal, γ, ω, and π crystallographic planes, are common in vein quartz in low-grade tectonometamorphic settings. We conclude that the observation of multiple (2-3) sets of fine scale, closely spaced, crystallographically controlled, sub-planar microstructures is not sufficient to unambiguously distinguish PDFs from tectonic FEBs.

Multi-projector auto-calibration and placement optimization for non-planar surfaces

NASA Astrophysics Data System (ADS)

Li, Dong; Xie, Jinghui; Zhao, Lu; Zhou, Lijing; Weng, Dongdong

2015-10-01

Non-planar projection has been widely applied in virtual reality and digital entertainment and exhibitions because of its flexible layout and immersive display effects. Compared with planar projection, a non-planar projection is more difficult to achieve because projector calibration and image distortion correction are difficult processes. This paper uses a cylindrical screen as an example to present a new method for automatically calibrating a multi-projector system in a non-planar environment without using 3D reconstruction. This method corrects the geometric calibration error caused by the screen's manufactured imperfections, such as an undulating surface or a slant in the vertical plane. In addition, based on actual projection demand, this paper presents the overall performance evaluation criteria for the multi-projector system. According to these criteria, we determined the optimal placement for the projectors. This method also extends to surfaces that can be parameterized, such as spheres, ellipsoids, and paraboloids, and demonstrates a broad applicability.

Planar-Processed Polymer Transistors.

PubMed

Xu, Yong; Sun, Huabin; Shin, Eul-Yong; Lin, Yen-Fu; Li, Wenwu; Noh, Yong-Young

2016-10-01

Planar-processed polymer transistors are proposed where the effective charge injection and the split unipolar charge transport are all on the top surface of the polymer film, showing ideal device characteristics with unparalleled performance. This technique provides a great solution to the problem of fabrication limitations, the ambiguous operating principle, and the performance improvements in practical applications of conjugated-polymer transistors. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental Assessment and Enhancement of Planar Laser-Induced Fluorescence Measurements of Nitric Oxide in an Inverse Diffusion Flame

NASA Technical Reports Server (NTRS)

Partridge, William P.; Laurendeau, Normand M.

1997-01-01

We have experimentally assessed the quantitative nature of planar laser-induced fluorescence (PLIF) measurements of NO concentration in a unique atmospheric pressure, laminar, axial inverse diffusion flame (IDF). The PLIF measurements were assessed relative to a two-dimensional array of separate laser saturated fluorescence (LSF) measurements. We demonstrated and evaluated several experimentally-based procedures for enhancing the quantitative nature of PLIF concentration images. Because these experimentally-based PLIF correction schemes require only the ability to make PLIF and LSF measurements, they produce a more broadly applicable PLIF diagnostic compared to numerically-based correction schemes. We experimentally assessed the influence of interferences on both narrow-band and broad-band fluorescence measurements at atmospheric and high pressures. Optimum excitation and detection schemes were determined for the LSF and PLIF measurements. Single-input and multiple-input, experimentally-based PLIF enhancement procedures were developed for application in test environments with both negligible and significant quench-dependent error gradients. Each experimentally-based procedure provides an enhancement of approximately 50% in the quantitative nature of the PLIF measurements, and results in concentration images nominally as quantitative as LSF point measurements. These correction procedures can be applied to other species, including radicals, for which no experimental data are available from which to implement numerically-based PLIF enhancement procedures.

3D spatially encoded and accelerated TE-averaged echo planar spectroscopic imaging in healthy human brain.

PubMed

Iqbal, Zohaib; Wilson, Neil E; Thomas, M Albert

2016-03-01

Several different pathologies, including many neurodegenerative disorders, affect the energy metabolism of the brain. Glutamate, a neurotransmitter in the brain, can be used as a biomarker to monitor these metabolic processes. One method that is capable of quantifying glutamate concentration reliably in several regions of the brain is TE-averaged (1) H spectroscopic imaging. However, this type of method requires the acquisition of multiple TE lines, resulting in long scan durations. The goal of this experiment was to use non-uniform sampling, compressed sensing reconstruction and an echo planar readout gradient to reduce the scan time by a factor of eight to acquire TE-averaged spectra in three spatial dimensions. Simulation of glutamate and glutamine showed that the 2.2-2.4 ppm spectral region contained 95% glutamate signal using the TE-averaged method. Peak integration of this spectral range and home-developed, prior-knowledge-based fitting were used for quantitation. Gray matter brain phantom measurements were acquired on a Siemens 3 T Trio scanner. Non-uniform sampling was applied retrospectively to these phantom measurements and quantitative results of glutamate with respect to creatine 3.0 (Glu/Cr) ratios showed a coefficient of variance of 16% for peak integration and 9% for peak fitting using eight-fold acceleration. In vivo scans of the human brain were acquired as well and five different brain regions were quantified using the prior-knowledge-based algorithm. Glu/Cr ratios from these regions agreed with previously reported results in the literature. The method described here, called accelerated TE-averaged echo planar spectroscopic imaging (TEA-EPSI), is a significant methodological advancement and may be a useful tool for categorizing glutamate changes in pathologies where affected brain regions are not known a priori. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Brachytherapy treatment simulation of strontium-90 and ruthenium-106 plaques on small size posterior uveal melanoma using MCNPX code

NASA Astrophysics Data System (ADS)

Barbosa, N. A.; da Rosa, L. A. R.; Facure, A.; Braz, D.

2014-02-01

Concave eye applicators with 90Sr/90Y and 106Ru/106Rh beta-ray sources are usually used in brachytherapy for the treatment of superficial intraocular tumors as uveal melanoma with thickness up to 5 mm. The aim of this work consisted in using the Monte Carlo code MCNPX to calculate the 3D dose distribution on a mathematical model of the human eye, considering 90Sr/90Y and 160Ru/160Rh beta-ray eye applicators, in order to treat a posterior uveal melanoma with a thickness 3.8 mm from the choroid surface. Mathematical models were developed for the two ophthalmic applicators, CGD produced by BEBIG Company and SIA.6 produced by the Amersham Company, with activities 1 mCi and 4.23 mCi respectively. They have a concave form. These applicators' mathematical models were attached to the eye model and the dose distributions were calculated using the MCNPX *F8 tally. The average doses rates were determined in all regions of the eye model. The *F8 tally results showed that the deposited energy due to the applicator with the radionuclide 106Ru/106Rh is higher in all eye regions, including tumor. However the average dose rate in the tumor region is higher for the applicator with 90Sr/90Y, due to its high activity. Due to the dosimetric characteristics of these applicators, the PDD value for 3 mm water is 73% for the 106Ru/106Rh applicator and 60% for 90Sr/90Y applicator. For a better choice of the applicator type and radionuclide it is important to know the thickness of the tumor and its location.

Novel planar field emission of ultra-thin individual carbon nanotubes.

PubMed

Song, Xuefeng; Gao, Jingyun; Fu, Qiang; Xu, Jun; Zhao, Qing; Yu, Dapeng

2009-10-07

In this work, we proposed and realized a new prototype of planar field emission device based on as-grown individual carbon nanotubes (CNTs) on the surface of a Si-SiO2 substrate. The anode, cathode and the CNT tip all lie on the same surface, so the electron emission is reduced from three-dimensional to two-dimensional. The benefits of such a design include usage of thinner CNT emitters, integrity with planar technology, stable construction, better heat dissipation, etc. A tip-to-tip field emission device was presented besides the tip-to-electrode one. Real-time, in situ observation of the planar field emission was realized in a scanning electron microscope (SEM). Measurements showed that the minimum voltage for 10 nA field emission current was only 8.0 V and the maximum emission current density in an individual CNT emitter (1.0 nm in diameter) exceeded 5.7 x 10(8) A cm(-2). These results stand out in the comparison with recent works on individual CNT field emission, indicating that the planar devices based on ultra-thin individual CNTs are more competitive candidates for next-generation electron field emitters.

Design and analysis of optical waveguide elements in planar geometry

NASA Astrophysics Data System (ADS)

Mirkov, Mirko Georgiev

1998-10-01

This dissertation presents the theoretical analysis and practical design considerations for planar optical waveguide devices. The analysis takes into account both transverse dimensions of the waveguides and is based on the supermode theory combined with the resonance method for determination of the propagation constants and field profiles of the supermodes. An improved accuracy has been achieved by including the corrections due to the fields in the corner regions of the waveguides using perturbation theory. The following two classes of devices have been analyzed in detail. Curved rectangular waveguides are a common element in an integrated optics circuit. The theoretical analysis in this work shows that some commonly used approximations for determination of the propagation constants of the quasi-modes of the bent waveguides are not necessary. Specifically the imaginary part of the mode propagation constant, which determines the power loss, is calculated exactly using the resonance method, combined with a two- dimensional optimization routine for determination of the real and the imaginary parts of the propagation constants. Subsequently, the results are corrected for the effects of the fields in the corner regions. The latter corrections have not been previously computed and are shown to be significant. Power splitters are another common element of an integrated optical circuit. A new 'bend-free' splitter is suggested and analyzed. The new splitter design consists of only straight parallel channels, which considerably simplify both the analysis and the fabrication of the device. It is shown that a single design parameter determines the power splitting ratio, which can take any given value. The intrinsic power loss in the proposed splitter is minimal, which makes it an attractive alternative to the conventional Y-splitters. The accurate methods of analysis of planar optical waveguides developed in the present work can easily be applied to other integrated optic

Study of curved and planar frequency-selective surfaces with nonplanar illumination

NASA Technical Reports Server (NTRS)

Caroglanian, Armen; Webb, Kevin J.

1991-01-01

A locally planar technique (LPT) is investigated for determining the forward-scattered field from a generally shaped inductive frequency-selective surface (FSS) with nonplanar illumination. The results of an experimental study are presented to assess the LPT accuracy. The effects of a nonplanar incident field are determined by comparing the LPT numerical results with a series of experiments with the feed source placed at varying distances from the planar FSS. The limitations of the LPT model due to surface curvature are investigated in an experimental study of the scattered fields from a set of hyperbolic cylinders of different curvatures. From these comparisons, guidelines for applying the locally planar technique are developed.

Three-Phase Time-Multiplexed Planar Power Transmission to Distributed Implants.

PubMed

Lee, Byunghun; Ahn, Dukju; Ghovanloo, Maysam

2016-03-01

A platform has been presented for wireless powering of receivers (Rx's) that are arbitrarily distributed over a large area. A potential application could be powering of small Rx implants, distributed over large areas of the brain. The transmitter (Tx) consists of three overlapping layers of hexagonal planar spiral coils (hex-PSC) that are horizontally shifted to provide the strongest and most homogeneous electromagnetic flux coverage. The three-layer hex-PSC array is driven by a three-phase time-division-multiplexed power Tx that takes the advantage of the carrier phase shift, coil geometries, and Rx time constant to homogeneously power the arbitrarily distributed Rx's regardless of their misalignments. The functionality of the proposed three-phase power transmission concept has been verified in a detailed scaled-up high-frequency structure simulator Advanced Design System simulation model and measurement setup, and compared with a conventional Tx. The new Tx delivers 5.4 mW to each Rx and achieves, on average, 5.8% power transfer efficiency to the Rx at the worst case 90° angular misalignment, compared with 1.4% by the conventional Tx.

Planar cell polarity: one or two pathways?

PubMed Central

Lawrence, Peter A; Struhl, Gary; Casal, José

2009-01-01

In multicellular organisms, cells are polarised in the plane of the epithelial sheet, demonstrated in some cell types by oriented hairs or cilia. Many of the genes involved have been identified in Drosophila and are conserved in vertebrates. Here we dissect the logic of planar cell polarity (PCP). We review studies of genetic mosaics in adult flies. Marked cells of different genotypes are confronted, the aim being to understand how polarising information is generated and how it passes from one cell to another. We argue that the prevailing opinion that planar polarity depends on a single genetic pathway is wrong and conclude there are (at least) two independently acting processes. This conclusion has major consequences for the PCP field. PMID:17563758

Isobaric analog resonances in (e,e'p) on $sup 90$Zr, $sup 89$Y, and $sup 88$Sr

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

Shoda, K.; Sugawara, M.; Saito, T.

1974-01-01

Photoproton energy and angular distributions were measured for the (e,e'p) reaction on /sup 90/Zr, /sup 89/Y and /sup 88/Sr at a number of elec tron bombarding energies. Proton groups passing through resonances are found in the energy distributions. The dependence on the residual states is studied, and it is found that a large contribution from core excitation exists in the strong E1 IAS. The configurations of these IAS are discussed with respect to the angular distributions. Cross sections of the ( gamma ,p/sub o/) reaction were extracted from the photoproton spectra. The results show a coherent T + 1 resonancemore » in good agreement with theory. The E1 IAS are compared with the results from various types of nuclear reactions. Strerigths of the IAR are found to depend on the type of reaction. (16 figures, 5 tables) (auth)« less

Weakly nonlinear incompressible Rayleigh-Taylor instability in spherical and planar geometries

NASA Astrophysics Data System (ADS)

Zhang, J.; Wang, L. F.; Ye, W. H.; Guo, H. Y.; Wu, J. F.; Ding, Y. K.; Zhang, W. Y.; He, X. T.

2018-02-01

The relationship between the weakly nonlinear (WN) solutions of the Rayleigh-Taylor instability in spherical geometry [Zhang et al., Phys. Plasmas 24, 062703 (2017)] and those in planar geometry [Wang et al., Phys. Plasmas 19, 112706 (2012)] is analyzed. In the high-mode perturbation limit ( Pn(cos θ), n ≫1 ), it is found that at the equator, the contributions of mode P2 n along with its neighboring modes, mode P3 n along with its neighboring modes, and mode Pn at the third order along with its neighboring modes are equal to those of the second harmonic, the third harmonic, and the third-order feedback to the fundamental mode, respectively, in the planar case with a perturbation of the same wave vector and amplitude as those at the equator. The trends of WN results in spherical geometry towards the corresponding planar counterparts are found, and the convergence behaviors of the neighboring modes of Pn, P2 n , and P3 n are analyzed. Moreover, the spectra generated from the high-mode perturbations in the WN regime are provided. For low-mode perturbations, it is found that the fundamental modes saturate at larger amplitudes than the planar result. The geometry effect makes the bubbles at or near the equator grow faster than the bubbles in planar geometry in the WN regime.

Experience with indium-111 and yttrium-90-labeled somatostatin analogs.

PubMed

Virgolini, I; Traub, T; Novotny, C; Leimer, M; Füger, B; Li, S R; Patri, P; Pangerl, T; Angelberger, P; Raderer, M; Burggasser, G; Andreae, F; Kurtaran, A; Dudczak, R

2002-01-01

The high level expression of somatostatin receptors (SSTR) on various tumor cells has provided the molecular basis for successful use of radiolabeled octreotide / lanreotide analogs as tumor tracers in nuclear medicine. Other (nontumoral) potential indications for SSTR scintigraphy are based on an increased lymphocyte binding at sites of inflammatory or immunologic diseases such as thyroid-associated ophthalmology. The vast majority of human tumors seem to over-express the one or the other of five distinct hSSTR subtype receptors. Whereas neuroendocrine tumors frequently overexpress hSSTR2, intestinal adenocarcinomas seem to overexpress more often hSSTR3 or hSSTR4, or both of these hSSTR. In contrast to In-DTPA-DPhe(1)-octreotide (OctreoScan(R)) which binds to hSSTR2 and 5 with high affinity (Kd 0.1-5 nM), to hSSTR3 with moderate affinity (K(d) 10-100 nM) and does not bind to hSSTR1 and hSSTR4, (111)In / (90)Y-DOTA-lanreotide was found to bind to hSSTR2, 3, 4, and 5 with high affinity, and to hSSTR1 with lower affinity (K(d) 200 nM). Based on its unique hSSTR binding profile, (111)In-DOTA-lanreotide was suggested to be a potential radioligand for tumor diagnosis, and (90)Y-DOTA-lanreotide suitable for receptor-mediated radionuclide therapy. As opposed to (111)In-DTPA-DPhe(1)-octreotide and (111)In-DOTA-DPhe(1)-Tyr(3)-octreotide, discrepancies in the scintigraphic results were seen in about one third of (neuroendocrine) tumor patients concerning both the tumor uptake as well as detection of tumor lesions. On a molecular level, these discrepancies seem to be based on a "higherrdquuo; high-affinity binding of (111)In-DOTA-DPhe(1)-Tyr(3)-octreotide to hSSTR2 (K(d) 0.1-1 nM). Other somatostatin analogs with divergent affinity to the five known hSSTR subtype receptors have also found their way into the clinics, such as (99m)Tc-depreotide (NeoSpect(R); NeoTect(R)). Most of the imaging results are reported for neuroendocrine tumors (octreotide analogs) or nonsmall cell

Cement As a Waste Form for Nuclear Fission Products: The Case of 90Sr and Its Daughters [Cement As a Container for Nuclear Fission Products: The Case of 90Sr and Its Daughters

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

Dezerald, Lucile; Kohanoff, Jorge J.; Correa, Alfredo A.

One of the main challenges faced by the nuclear industry is the long-term confinement of nuclear waste. Because it is inexpensive and easy to manufacture, cement is the material of choice to store large volumes of radioactive materials, in particular the low-level medium-lived fission products. It is therefore of utmost importance to assess the chemical and structural stability of cement containing radioactive species. Here, we use ab initio calculations based on density functional theory (DFT) to study the effects of 90Sr insertion and decay in C–S–H (calcium-silicate-hydrate) in order to test the ability of cement to trap and hold thismore » radioactive fission product and to investigate the consequences of its β-decay on the cement paste structure. We show that 90Sr is stable when it substitutes the Ca 2+ ions in C–S–H, and so is its daughter nucleus 90Y after β-decay. Interestingly, 90Zr, daughter of 90Y and final product in the decay sequence, is found to be unstable compared to the bulk phase of the element at zero K but stable when compared to the solvated ion in water. Furthermore, cement appears as a suitable waste form for 90Sr storage.« less

Cement As a Waste Form for Nuclear Fission Products: The Case of 90Sr and Its Daughters [Cement As a Container for Nuclear Fission Products: The Case of 90Sr and Its Daughters

DOE PAGES

Dezerald, Lucile; Kohanoff, Jorge J.; Correa, Alfredo A.; ...

2015-10-29

One of the main challenges faced by the nuclear industry is the long-term confinement of nuclear waste. Because it is inexpensive and easy to manufacture, cement is the material of choice to store large volumes of radioactive materials, in particular the low-level medium-lived fission products. It is therefore of utmost importance to assess the chemical and structural stability of cement containing radioactive species. Here, we use ab initio calculations based on density functional theory (DFT) to study the effects of 90Sr insertion and decay in C–S–H (calcium-silicate-hydrate) in order to test the ability of cement to trap and hold thismore » radioactive fission product and to investigate the consequences of its β-decay on the cement paste structure. We show that 90Sr is stable when it substitutes the Ca 2+ ions in C–S–H, and so is its daughter nucleus 90Y after β-decay. Interestingly, 90Zr, daughter of 90Y and final product in the decay sequence, is found to be unstable compared to the bulk phase of the element at zero K but stable when compared to the solvated ion in water. Furthermore, cement appears as a suitable waste form for 90Sr storage.« less

Planar triode pulser socket

DOEpatents

Booth, Rex

1994-01-01

A planar triode is mounted in a PC board orifice by means of a U-shaped capacitor housing and anode contact yoke removably attached to cathode leg extensions passing through and soldered to the cathode side of the PC board by means of a PC cathode pad. A pliant/flexible contact attached to the orifice make triode grid contact with a grid pad on the grid side of the PC board, permitting quick and easy replacement of bad triodes.

Screening effect in matrix graphene / SiC planar field emmiters

NASA Astrophysics Data System (ADS)

Jityaev, I. L.; Svetlichnyi, A. M.; Kolomiytsev, A. S.; Ageev, O. A.

2017-11-01

The paper describes simulation of matrix field emission nanostructures on the basis of graphene on a semi-insulating silicon carbide. The planar spike-type field emission cathodes were measured. The electric field distribution in an interelectrode gap of the emission structure was obtained. The models take into account the distance between cathode tops. Screening effect condition was detected in planar field emission structure and a way of eliminating was proposed.

Planar Diffractive Lenses: Fundamentals, Functionalities, and Applications.

PubMed

Huang, Kun; Qin, Fei; Liu, Hong; Ye, Huapeng; Qiu, Cheng-Wei; Hong, Minghui; Luk'yanchuk, Boris; Teng, Jinghua

2018-06-01

Traditional objective lenses in modern microscopy, based on the refraction of light, are restricted by the Rayleigh diffraction limit. The existing methods to overcome this limit can be categorized into near-field (e.g., scanning near-field optical microscopy, superlens, microsphere lens) and far-field (e.g., stimulated emission depletion microscopy, photoactivated localization microscopy, stochastic optical reconstruction microscopy) approaches. However, they either operate in the challenging near-field mode or there is the need to label samples in biology. Recently, through manipulation of the diffraction of light with binary masks or gradient metasurfaces, some miniaturized and planar lenses have been reported with intriguing functionalities such as ultrahigh numerical aperture, large depth of focus, and subdiffraction-limit focusing in far-field, which provides a viable solution for the label-free superresolution imaging. Here, the recent advances in planar diffractive lenses (PDLs) are reviewed from a united theoretical account on diffraction-based focusing optics, and the underlying physics of nanofocusing via constructive or destructive interference is revealed. Various approaches of realizing PDLs are introduced in terms of their unique performances and interpreted by using optical aberration theory. Furthermore, a detailed tutorial about applying these planar lenses in nanoimaging is provided, followed by an outlook regarding future development toward practical applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Edge effects on the fluttering characteristics of freely falling planar particles

NASA Astrophysics Data System (ADS)

Blay Esteban, Luis; Shrimpton, John; Ganapathisubramani, Bharathram

2018-06-01

The effect of particle edge geometry on the descent motion of freely falling planar particles is examined through experiments. Various planar particles, such as disk and polygons, with identical frontal areas (Ap) and different number of edges (or perimeter) are used. All particles are designed such that their values of Galileo number (G ) and dimensionless moment of inertia (I*) correspond to the previously identified fluttering regime of particle motion. Several modes of secondary motion are observed for the same particle and conditions, and these are not equally probable. This probability depends on the particle shape. Disks and heptagons were found to prefer a "planar zig-zag" behavior. These planar motions are composed of gliding sweeps and turning sections. As the number of sides in the polygon decreases, i.e., for hexagons and pentagons, the trajectory transitions to a more three-dimensional form. These trajectories were found to be restricted to one plane per swing, but the subsequent swings are in other planes. Further decrease in number of sides to a square results in the trajectories having a severe out-of-plane motion. These subregimes of particle motion within the fluttering regime are consistent with those reported for disks in previous studies. Based on this information, a length scale that accounts for the frontal area of the particles and its edge geometry (i.e., perimeter) is proposed. This length scale represents an approach to determine an equivalent disk for planar particles such that the phase diagram in the Reynolds number (Re) and dimensionless moment of inertia (I*) domain can be used to characterize the motion of planar particles with different frontal geometries. However, further experiments covering other domains of the regime map are needed to verify its universality.

Planar PCB Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review

USGS Publications Warehouse

Eisler, R.; Belisle, A.A.

1996-01-01

Ecological and toxicological aspects of polychlorinated biphenyls (PCBs) in the environment are reviewed with emphasis on biologically active congeners and fish and wildlife. Subtopics include sources and uses, chemical and biochemical properties, concentrations in field collections, lethal and sublethal effects, and recommendations for the protection of sensitive resources. All production of PCBs in the United States ceased in 1977. Of the 1.2 million tons of PCBs manufactured to date, about 65% are still in use in electrical equipment and 31% in various environmental compartments, and 4% were degraded or incinerated. The 209 PCB congeners and their metabolites show wide differences in biological effects. A significant part of the toxicity associated with commercial PCB mixtures is related to the presence of about 20 planar congeners, i.e., congeners without chlorine substitution in the ortho position. Toxic planar congeners, like other PCB congeners, have been detected in virtually all analyzed samples, regardless of collection locale. Planar PCB concentrations were usually highest in samples from near urban areas and in fat and liver tissues, filter-feeding bivalve mollusks, fish-eating birds, and carnivorous marine mammals. Adverse effects of planar PCBs on growth, survival, and reproduction are highly variable because of numerous biotic and abiotic modifiers, including interaction with other chemicals. In general, embryos and juveniles were the most sensitive stages tested to planar PCBs, and the chinook salmon, domestic chicken, mink, rhesus macaque, and laboratory white rat were among the most sensitive species. for protection of natural resources, most authorities now recommend (1) analyzation of environmental samples for planar and other potentially hazardous congeners; (2) exposure studies with representative species and specific congeners, alone and in combination with other environmental contaminants; (3) clarification of existing structure

Generation of whistler-wave heated discharges with planar resonant RF networks.

PubMed

Guittienne, Ph; Howling, A A; Hollenstein, Ch

2013-09-20

Magnetized plasma discharges generated by a planar resonant rf network are investigated. A regime transition is observed above a magnetic field threshold, associated with rf waves propagating in the plasma and which present the characteristics of whistler waves. These wave heated regimes can be considered as analogous to conventional helicon discharges, but in planar geometry.

Preparation & in vitro evaluation of ⁹⁰Y-DOTA-rituximab.

PubMed

Kameswaran, Mythili; Pandey, Usha; Dash, Ashutosh; Samuel, Grace; Venkatesh, Meera

2016-01-01

Radioimmunotherapy is extensively being used for the treatment of non-Hodgkin's lymphoma (NHL). Use of rituximab, a chimeric anti-CD20 antibody directed against the CD20 antigen in combination with suitable beta emitters is expected to result in good treatment response by its cross-fire and bystander effects. The present work involves the conjugation of p-isothiocyanatobenzyl DOTA (p-SCN-Bn-DOTA) to rituximab, its radiolabelling with [90] Y and in vitro and in vivo evaluation to determine its potential as a radioimmunotherapeutic agent. Rituximab was conjugated with p-SCN-Bn-DOTA at 1:1 antibody: DOTA molar ratio. The number of DOTA molecules linked to one molecule of rituximab was determined by radioassay and spectroscopic assay. Radiolabelling of rituximab with 90 Y was carried out and its in vitro stability was evaluated. In vitro cell binding studies were carried out in Raji cells expressing CD20 antigen. Biodistribution studies were carried out in normal Swiss mice. Using both radioassay and spectroscopic method, it was determined that about five molecules of DOTA were linked to rituximab. Radiolabelling of the rituximab conjugate with [90] Y and subsequent purification on PD-10 column gave a product with radiochemical purity (RCP) > 98 per cent which was retained at > 90 per cent up to 72 h when stored at 37°C. In vitro cell binding experiments of 90 Y-DOTA-rituximab with Raji cells exhibited specific binding of 20.7 ± 0.1 per cent with [90] Y-DOTA-rituximab which reduced to 15.5 ± 0.2 per cent when incubated with cold rituximab. The equilibrium constant K d for 90 Y-DOTA-Rituximab was determined to be 3.38 nM. Radiolabelled antibody showed clearance via hepatobiliary and renal routes and activity in tibia was found to be quite low indicating in vivo stability of [90] Y-DOTA-rituximab. p-SCN-Bn-DOTA was conjugated with rituximab and radiolabelling with 90 Y was carried out. In vitro studies carried out in Raji cells showed the specificity of the

Effects of planar shear on the three-dimensional instability in flow past a circular cylinder

NASA Astrophysics Data System (ADS)

Park, Doohyun; Yang, Kyung-Soo

2018-03-01

A Floquet stability analysis has been carried out in order to investigate how a planar shear in wake flow affects the three-dimensional (3D) instability in the near-wake region. We consider a circular cylinder immersed in a freestream with planar shear. The cylinder was implemented in a Cartesian grid system by means of an immersed boundary method. Planar shear tends to promote the primary instability, known as Hopf bifurcation where steady flow bifurcates into time-periodic flow, in the sense that its critical Reynolds number decreases with increasing planar shear. The effects of planar shear on the 3D instability are different depending on the type of 3D instability. The flow asymmetry caused by the planar shear suppresses a QP-type mode but generates a C-type mode. The conventional A and B modes are stabilized by the planar shear, whereas mode C is intensified with increasing shear. The criticality of each 3D mode is discussed, and the neutral stability curves for each 3D mode are presented. The current Floquet results have been validated by using direct numerical simulation for some selected cases of flow parameters.

Design and investigation of properties of nanocrystalline diamond optical planar waveguides.

PubMed

Prajzler, Vaclav; Varga, Marian; Nekvindova, Pavla; Remes, Zdenek; Kromka, Alexander

2013-04-08

Diamond thin films have remarkable properties comparable with natural diamond. Because of these properties it is a very promising material for many various applications (sensors, heat sink, optical mirrors, chemical and radiation wear, cold cathodes, tissue engineering, etc.) In this paper we report about design, deposition and measurement of properties of optical planar waveguides fabricated from nanocrystalline diamond thin films. The nanocrystalline diamond planar waveguide was deposited by microwave plasma enhanced chemical vapor deposition and the structure of the deposited film was studied by scanning electron microscopy and Raman spectroscopy. The design of the presented planar waveguides was realized on the bases of modified dispersion equation and was schemed for 632.8 nm, 964 nm, 1 310 nm and 1 550 nm wavelengths. Waveguiding properties were examined by prism coupling technique and it was found that the diamond based planar optical element guided one fundamental mode for all measured wavelengths. Values of the refractive indices of our NCD thin film measured at various wavelengths were almost the same as those of natural diamond.

Surface thermodynamics of planar, cylindrical, and spherical vapour-liquid interfaces of water

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

Lau, Gabriel V.; Müller, Erich A.; Jackson, George

2015-03-21

The test-area (TA) perturbation approach has been gaining popularity as a methodology for the direct computation of the interfacial tension in molecular simulation. Though originally implemented for planar interfaces, the TA approach has also been used to analyze the interfacial properties of curved liquid interfaces. Here, we provide an interpretation of the TA method taking the view that it corresponds to the change in free energy under a transformation of the spatial metric for an affine distortion. By expressing the change in configurational energy of a molecular configuration as a Taylor expansion in the distortion parameter, compact relations are derivedmore » for the interfacial tension and its energetic and entropic components for three different geometries: planar, cylindrical, and spherical fluid interfaces. While the tensions of the planar and cylindrical geometries are characterized by first-order changes in the energy, that of the spherical interface depends on second-order contributions. We show that a greater statistical uncertainty is to be expected when calculating the thermodynamic properties of a spherical interface than for the planar and cylindrical cases, and the evaluation of the separate entropic and energetic contributions poses a greater computational challenge than the tension itself. The methodology is employed to determine the vapour-liquid interfacial tension of TIP4P/2005 water at 293 K by molecular dynamics simulation for planar, cylindrical, and spherical geometries. A weak peak in the curvature dependence of the tension is observed in the case of cylindrical threads of condensed liquid at a radius of about 8 Å, below which the tension is found to decrease again. In the case of spherical drops, a marked decrease in the tension from the planar limit is found for radii below ∼ 15 Å; there is no indication of a maximum in the tension with increasing curvature. The vapour-liquid interfacial tension tends towards the planar limit

Integrated packaging of multiple double sided cooling planar bond power modules

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

Liang, Zhenxian

An integrated double sided cooled power module has one or multiple phase legs configuration including one or more planar power packages, each planar power package having an upper power switch unit and a lower power switch unit directly bonded and interconnected between two insulated power substrates, and further sandwiched between two heat exchangers via direct bonds. A segmented coolant manifold is interposed with the one or more planar power packages and creates a sealed enclosure that defines a coolant inlet, a coolant outlet and a coolant flow path between the inlet and the outlet. A coolant circulates along the flowmore » path to remove heat and increase the power density of the power module.« less

Effects of geometric configuration on droplet generation in Y-junctions and anti-Y-junctions microchannels

NASA Astrophysics Data System (ADS)

Liu, Zhao-Miao; Liu, Li-Kun; Shen, Feng

2015-10-01

Droplets generation in Y-junctions and anti-Y-junctions microchannels are experimentally studied using a high speed digital microscopic system and numerical simulation. Geometric configuration of a microchannel, such as Y-angle (90°, 135°, -90° and -135°), channel depth and other factors have been taken into consideration. It is found that droplets generated in anti-Y-junctions have a smaller size and a shorter generation cycle compared with those in Y-junctions under the same experimental conditions. Through observing the internal velocity field, the vortex appearing in continuous phase in anti-Y-junctions is one of the key factors for the difference of droplet size and generation cycle. It is found that droplet size is bigger and generation cycle is longer when the absolute angle value of the intersection between the continuous and the dispersed phases (i.e., the angle between the main channel and the continuous phase or the dispersed phase channel) increases. The droplet's size is influenced by the Y-angle, which varies with the channel depth in Y-junctions. The Y-angle has a positive effect on the droplet generation cycle, but a smaller height-width ratio will enhance the impact of a continuous and dispersed phase's intersection angle on the droplet generation cycle in Y-junctions microchannels.

Robust magnon-photon coupling in a planar-geometry hybrid of inverted split-ring resonator and YIG film.

PubMed

Bhoi, Biswanath; Kim, Bosung; Kim, Junhoe; Cho, Young-Jun; Kim, Sang-Koog

2017-09-20

We experimentally demonstrate strongly enhanced coupling between excited magnons in an Yttrium Iron Garnet (YIG) film and microwave photons in an inverted pattern of split-ring resonator (noted as ISRR). The anti-crossing effects of the ISRR's photon mode and the YIG's magnon modes were found from |S 21 |-versus-frequency measurements for different strengths and directions of externally applied magnetic fields. The spin-number-normalized coupling strength (i.e. single spin-photon coupling) [Formula: see text] was determined to 0.194 Hz ([Formula: see text] = 90 MHz) at 3.7 GHz frequency. Furthermore, we found that additional fine features in the anti-crossing region originate from the excitation of different spin-wave modes (such as the magnetostatic surface and the backward-volume magnetostatic spin-waves) rather than the Kittel-type mode. These spin-wave modes, as coupled with the ISRR mode, modify the anti-crossing effect as well as their coupling strength. An equivalent circuit model very accurately reproduced the observed anti-crossing effect and its coupling strength variation with the magnetic field direction in the planar-geometry ISRR/YIG hybrid system. This work paves the way for the design of new types of high-gain magnon-photon coupling systems in planar geometry.

Planar-integrated single-crystalline perovskite photodetectors

PubMed Central

Saidaminov, Makhsud I.; Adinolfi, Valerio; Comin, Riccardo; Abdelhady, Ahmed L.; Peng, Wei; Dursun, Ibrahim; Yuan, Mingjian; Hoogland, Sjoerd; Sargent, Edward H.; Bakr, Osman M.

2015-01-01

Hybrid perovskites are promising semiconductors for optoelectronic applications. However, they suffer from morphological disorder that limits their optoelectronic properties and, ultimately, device performance. Recently, perovskite single crystals have been shown to overcome this problem and exhibit impressive improvements: low trap density, low intrinsic carrier concentration, high mobility, and long diffusion length that outperform perovskite-based thin films. These characteristics make the material ideal for realizing photodetection that is simultaneously fast and sensitive; unfortunately, these macroscopic single crystals cannot be grown on a planar substrate, curtailing their potential for optoelectronic integration. Here we produce large-area planar-integrated films made up of large perovskite single crystals. These crystalline films exhibit mobility and diffusion length comparable with those of single crystals. Using this technique, we produced a high-performance light detector showing high gain (above 104 electrons per photon) and high gain-bandwidth product (above 108 Hz) relative to other perovskite-based optical sensors. PMID:26548941

Free space and waveguide Talbot effect: phase relations and planar light circuit applications

NASA Astrophysics Data System (ADS)

Nikkhah, H.; Zheng, Q.; Hasan, I.; Abdul-Majid, S.; Hall, T. J.

2012-10-01

Optical fields that are periodic in the transverse plane self-image periodically as they propagate along the optical axis: a phenomenon known as the Talbot effect. A transfer matrix may be defined that relates the amplitude and phase of point sources placed on a particular grid at the input to their respective multiple images at an image plane. The free-space Talbot effect may be mapped to the waveguide Talbot effect. Applying this mapping to the transfer matrix enables the prediction of the phase and amplitude relations between the ports of a Multimode Interference (MMI) coupler- a planar waveguide device. The transfer matrix approach has not previously been applied to the free-space case and its mapping to the waveguide case provides greater clarity and physical insight into the phase relationships than previous treatments. The paper first introduces the underlying physics of the Talbot effect in free space with emphasis on the positions along the optical axis at which images occur; their multiplicity; and their relative phase relations determined by the Gauss Quadratic Sum of number theory. The analysis is then adapted to predict the phase relationships between the ports of an MMI. These phase relationships are critical to planar light circuit (PLC) applications such as 90° optical hybrids for coherent optical receiver front-ends, external optical I-Q modulators for coherent optical transmitters; and optical phased array switches. These applications are illustrated by results obtained from devices that have been fabricated and tested by the PTLab in Si micro-photonic integration platforms.

Planar triode pulser socket

DOEpatents

Booth, R.

1994-10-25

A planar triode is mounted in a PC board orifice by means of a U-shaped capacitor housing and anode contact yoke removably attached to cathode leg extensions passing through and soldered to the cathode side of the PC board by means of a PC cathode pad. A pliant/flexible contact attached to the orifice make triode grid contact with a grid pad on the grid side of the PC board, permitting quick and easy replacement of bad triodes. 14 figs.

A wide-band 760-GHz planar integrated Schottky receiver

NASA Technical Reports Server (NTRS)

Gearhart, Steven S.; Hesler, Jeffrey; Bishop, William L.; Crowe, Thomas W.; Rebeiz, Gabriel M.

1993-01-01

A wideband planar integrated heterodyne receiver has been developed for use at submillimeter-wave to FIR frequencies. The receiver consists of a log-periodic antenna integrated with a planar 0.8-micron GaAs Schottky diode. The monolithic receiver is placed on a silicon lens and has a measured room temperature double side-band conversion loss and noise temperature of 14.9 +/- 1.0 dB and 8900 +/- 500 K, respectively, at 761 GHz. These results represent the best performance to date for room temperature integrated receivers at this frequency.

Efficient forward second-harmonic generation from planar archimedean nanospirals

DOE PAGES

Davidson, II, Roderick B.; Ziegler, Jed I.; Vargas, Guillermo; ...

2015-05-01

Here, the enhanced electric field at plasmonic resonances in nanoscale antennas can lead to efficient harmonic generation, especially when the plasmonic geometry is asymmetric on either inter-particle or intra-particle levels. The planar Archimedean nanospiral offers a unique geometrical asymmetry for second-harmonic generation (SHG) because the SHG results neither from arranging centrosymmetric nanoparticles in asymmetric groupings, nor from non-centrosymmetric nanoparticles that retain a local axis of symmetry. Here, we report forward SHG from planar arrays of Archimedean nanospirals using 15 fs pulses from a Ti:sapphire oscillator tuned to 800 nm wavelength.

Planar waveguide sensor of ammonia

NASA Astrophysics Data System (ADS)

Rogoziński, Roman; Tyszkiewicz, Cuma; Karasiński, Paweł; Izydorczyk, Weronika

2015-12-01

The paper presents the concept of forming ammonia sensor based on a planar waveguide structure. It is an amplitude sensor produced on the basis of the multimode waveguide. The technological base for this kind of structure is the ion exchange method and the sol-gel method. The planar multimode waveguide of channel type is produced in glass substrate (soda-lime glass of Menzel-Glaser company) by the selective Ag+↔Na+ ion exchange. On the surface of the glass substrate a porous (~40%) silica layer is produced by the sol-gel method. This layer is sensitized to the presence of ammonia in the surrounding atmosphere by impregnation with Bromocresol Purple (BCP) dye. Therefore it constitutes a sensor layer. Spectrophotometric tests carried out showed about 50% reduction of cross-transmission changes of such sensor layer for a wave λ=593 nm caused by the presence of 25% ammonia water vapor in its ambience. The radiation source used in this type of sensor structure is a light emitting diode LED. The gradient channel waveguide is designed for frontal connection (optical glue) with a standard multimode telecommunications waveguide 62.5/125μm.

Planar xanthomas secondary to post-transplantation cholangiopathy in a 16-month-old boy.

PubMed

Patel, Nirali; Norberg, Adam; Hogeling, Marcia

2018-05-01

Planar xanthomas in children represent rare dermatologic findings associated with abnormalities in lipid metabolism. While planar xanthomas in Alagille's syndrome have been well described in the literature, there have been no cases reported of eruptive xanthomas in pediatric liver transplant patients. Herein we report a case of a 16-month-old boy status post-liver transplantation who presents with planar xanthomas secondary to cholangiopathy. A brief review of xanthomas and the related literature is also provided. © 2018 Wiley Periodicals, Inc.

A Magnetic Resonance (MR) Microscopy System using a Microfluidically Cryo-Cooled Planar Coil

PubMed Central

Koo, Chiwan; Godley, Richard F.; Park, Jaewon; McDougall, Mary P.; Wright, Steven M.; Han, Arum

2011-01-01

We present the development of a microfluidically cryo-cooled planar coil for magnetic resonance (MR) microscopy. Cryogenically cooling radiofrequency (RF) coils for magnetic resonance imaging (MRI) can improve the signal to noise ratio (SNR) of the experiment. Conventional cryostats typically use a vacuum gap to keep samples to be imaged, especially biological samples, at or near room temperature during cryo-cooling. This limits how close a cryo-cooled coil can be placed to the sample. At the same time, a small coil-to-sample distance significantly improves the MR imaging capability due to the limited imaging depth of planar MR microcoils. These two conflicting requirements pose challenges to the use of cryo-cooling in MR microcoils. The use of a microfluidic based cryostat for localized cryo-cooling of MR microcoils is a step towards eliminating these constraints. The system presented here consists of planar receive-only coils with integrated cryo-cooling microfluidic channels underneath, and an imaging surface on top of the planar coils separated by a thin nitrogen gas gap. Polymer microfluidic channel structures fabricated through soft lithography processes were used to flow liquid nitrogen under the coils in order to cryo-cool the planar coils to liquid nitrogen temperature (−196°C). Two unique features of the cryo-cooling system minimize the distance between the coil and the sample: 1) The small dimension of the polymer microfluidic channel enables localized cooling of the planar coils, while minimizing thermal effects on the nearby imaging surface. 2) The imaging surface is separated from the cryo-cooled planar coil by a thin gap through which nitrogen gas flows to thermally insulate the imaging surface, keeping it above 0°C and preventing potential damage to biological samples. The localized cooling effect was validated by simulations, bench testing, and MR imaging experiments. Using this cryo-cooled planar coil system inside a 4.7 Tesla MR system

Revealing the planar chemistry of two-dimensional heterostructures at the atomic level.

PubMed

Chou, Harry; Ismach, Ariel; Ghosh, Rudresh; Ruoff, Rodney S; Dolocan, Andrei

2015-06-23

Two-dimensional (2D) atomic crystals and their heterostructures are an intense area of study owing to their unique properties that result from structural planar confinement. Intrinsically, the performance of a planar vertical device is linked to the quality of its 2D components and their interfaces, therefore requiring characterization tools that can reveal both its planar chemistry and morphology. Here, we propose a characterization methodology combining (micro-) Raman spectroscopy, atomic force microscopy and time-of-flight secondary ion mass spectrometry to provide structural information, morphology and planar chemical composition at virtually the atomic level, aimed specifically at studying 2D vertical heterostructures. As an example system, a graphene-on-h-BN heterostructure is analysed to reveal, with an unprecedented level of detail, the subtle chemistry and interactions within its layer structure that can be assigned to specific fabrication steps. Such detailed chemical information is of crucial importance for the complete integration of 2D heterostructures into functional devices.

Radioactive contamination of cistern waters along the Croatian coast of the Adriatic sea by 90Sr.

PubMed

Franić, Z; Lokobauer, N; Marović, G

1999-07-01

Measurements of radioactive contamination of water samples from cisterns collecting rainwater containing fission products from roofs and other surfaces have been carried out along the Croatian coast of the Adriatic sea since 1968. An exponential decline of radioactivity followed the nuclear moratorium. After the nuclear accident at Chernobyl, higher levels of 137Cs and 90Sr were detected again, with cistern waters being the only environmental samples in Croatia in which elevated 90Sr activities persisted for several years. For the pre-Chernobyl period, the observed mean residence time of 90Sr in cistern waters, estimated to be 6.2 +/- 1.9 y, was similar to that calculated for fallout. Contrary, for the post-Chernobyl time, observed 90Sr mean residence time was calculated to be considerably shorter, reflecting the tropospheric mean residence time. The annual dose for the critical adult population received from 90Sr and 137Cs by drinking cistern water was estimated to be very small, in the 1990's less than few microSv y(-1).

Insight on the proof of orientifold planar equivalence on the lattice

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

Patella, Agostino

2006-08-01

In a recent paper, Armoni, Shifman, and Veneziano (ASV) gave a formal nonperturbative proof of planar equivalence between the bosonic sectors of SU(N) super Yang-Mills theory and of a gauge theory with a massless quark in the antisymmetric two-indexes representation. In the case of three colors, the latter theory is nothing but one-flavor QCD. I will give a lattice version of the ASV proof of orientifold planar equivalence. It will be clear that it holds only in the strong-coupling and large-mass phase. Therefore, numerical simulations are necessary to test the validity of the orientifold planar equivalence in a physical regionmore » of the bare parameters on the lattice and to estimate the size of 1/N corrections.« less

A vision-based method for planar position measurement

NASA Astrophysics Data System (ADS)

Chen, Zong-Hao; Huang, Peisen S.

2016-12-01

In this paper, a vision-based method is proposed for three-degree-of-freedom (3-DOF) planar position (XY{θZ} ) measurement. This method uses a single camera to capture the image of a 2D periodic pattern and then uses the 2D discrete Fourier transform (2D DFT) method to estimate the phase of its fundamental frequency component for position measurement. To improve position measurement accuracy, the phase estimation error of 2D DFT is analyzed and a phase estimation method is proposed. Different simulations are done to verify the feasibility of this method and study the factors that influence the accuracy and precision of phase estimation. To demonstrate the performance of the proposed method for position measurement, a prototype encoder consisting of a black-and-white industrial camera with VGA resolution (480  ×  640 pixels) and an iPhone 4s has been developed. Experimental results show the peak-to-peak resolutions to be 3.5 nm in X axis, 8 nm in Y axis and 4 μ \\text{rad} in {θZ} axis. The corresponding RMS resolutions are 0.52 nm, 1.06 nm, and 0.60 μ \\text{rad} respectively.

A miniaturized planar patch-clamp system for transportable use.

PubMed

Boussaoud, Adrien; Fonteille, Isabelle; Collier, Guilhem; Kermarrec, Frédérique; Vermont, Fabien; Tresallet, Eric; De Waard, Michel; Arnoult, Christophe; Picollet-D'hahan, Nathalie

2012-02-15

In the last decade, planar patch-clamp (PPC) has emerged as an innovative technology allowing parallel recordings of cellular electrophysiological activity on planar substrates. If PPC is widely adopted by the pharmaceutical sector, it remains poorly extended to other areas (i.e. environment and safety organizations) probably because of the large, expensive and non-easily transportable format of those commercial equipments. The present work describes for the first time a new compact and transportable planar patch-clamp system (named Toxint'patch or TIP, for Toxin detection with integrated patch-clamp) focusing on environmental matters and meant to be used in coastal laboratories, for direct on-site monitoring of the seawater and shellfish quality. The TIP system incorporates silicon chips tailored to monitor cellular ionic currents from cultured cells stably expressing a phycotoxin molecular target. The functionality of this novel briefcase-sized PPC system is described in terms of fluidic control, electronic performances with amplifying and filtering boards and of user interface for data acquisition and control implemented on a computer. Copyright © 2011 Elsevier B.V. All rights reserved.

Diameter Dependence of Planar Defects in InP Nanowires

PubMed Central

Wang, Fengyun; Wang, Chao; Wang, Yiqian; Zhang, Minghuan; Han, Zhenlian; Yip, SenPo; Shen, Lifan; Han, Ning; Pun, Edwin Y. B.; Ho, Johnny C.

2016-01-01

In this work, extensive characterization and complementary theoretical analysis have been carried out on Au-catalyzed InP nanowires in order to understand the planar defect formation as a function of nanowire diameter. From the detailed transmission electron microscopic measurements, the density of stacking faults and twin defects are found to monotonically decrease as the nanowire diameter is decreased to 10 nm, and the chemical analysis clearly indicates the drastic impact of In catalytic supersaturation in Au nanoparticles on the minimized planar defect formation in miniaturized nanowires. Specifically, during the chemical vapor deposition of InP nanowires, a significant amount of planar defects is created when the catalyst seed sizes are increased with the lower degree of In supersaturation as dictated by the Gibbs-Thomson effect, and an insufficient In diffusion (or Au-rich enhancement) would lead to a reduced and non-uniform In precipitation at the NW growing interface. The results presented here provide an insight into the fabrication of “bottom-up” InP NWs with minimized defect concentration which are suitable for various device applications. PMID:27616584

Diameter Dependence of Planar Defects in InP Nanowires.

PubMed

Wang, Fengyun; Wang, Chao; Wang, Yiqian; Zhang, Minghuan; Han, Zhenlian; Yip, SenPo; Shen, Lifan; Han, Ning; Pun, Edwin Y B; Ho, Johnny C

2016-09-12

In this work, extensive characterization and complementary theoretical analysis have been carried out on Au-catalyzed InP nanowires in order to understand the planar defect formation as a function of nanowire diameter. From the detailed transmission electron microscopic measurements, the density of stacking faults and twin defects are found to monotonically decrease as the nanowire diameter is decreased to 10 nm, and the chemical analysis clearly indicates the drastic impact of In catalytic supersaturation in Au nanoparticles on the minimized planar defect formation in miniaturized nanowires. Specifically, during the chemical vapor deposition of InP nanowires, a significant amount of planar defects is created when the catalyst seed sizes are increased with the lower degree of In supersaturation as dictated by the Gibbs-Thomson effect, and an insufficient In diffusion (or Au-rich enhancement) would lead to a reduced and non-uniform In precipitation at the NW growing interface. The results presented here provide an insight into the fabrication of "bottom-up" InP NWs with minimized defect concentration which are suitable for various device applications.

Excretion pattern of co-planar and non-planar tetra- and hexa-chlorobiphenyls in ovine milk and faeces

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

Vrecl, Milka; Ursic, Matjaz; Pogacnik, Azra

This study employed the gas chromatography with electron capture detection to determine residual levels and excretion patterns of two pairs of structurally diverse polychlorinated biphenyl (PCB) congeners (IUPAC Nos. 54, 80, 155, and 169) administered to lactating sheep by intramuscular injection. PCB levels and excretion patterns in blood, milk, and faeces were time-dependent and differed from the composition of PCB congeners administered. Lactational transfer substantially exceeded the faecal transfer. Between days 3 and 7, the amount of PCB congeners 54 and 169 excreted in milk was around 50- and 800-fold higher than the amount of these two congeners excreted viamore » faeces. During the same period, the relative contribution of co-planar PCB congeners (80 and 169) in PCB pattern decreased in blood and increased in milk and faeces compared with non-planar PCBs (54 and 155). On day 3, the ratio PCB 169 to 54 was 7-fold higher in milk than in faeces. PCB congeners with log K{sub ow} values under 6.5 reached peaks of their excretion in milk within the first three days after administration, while the super-lipophilic PCB 169 congener with log K{sub ow} value of over 7 has not reached the plateau until day 10, but afterwards, its level remained relatively high throughout the observation period. During the 57-day follow-up period, the excretion of PCB 80, 155, and 169 in milk was 4.5-, 14-, and 46-fold greater compared with PCB 54. Differences in levels and patterns were explained with some physico-chemical properties of individual PCB congeners, such as lipophilicity, planarity, metabolic stability, sorption/diffusion properties.« less

Planar oscillatory stirring apparatus

NASA Technical Reports Server (NTRS)

Wolf, Martin F. (Inventor)

1987-01-01

Apparatus (11) for applying planar oscillations to a container (13). Pressurized air (99) is supplied to a moveable slide plate (27) which employs arms (19) having an air bearing vent structure (29, 31) which allows the slide plate to float and to translate. The container (13) to be oscillated is secured to the upper surface of the slide plate (27). A motor (39) driven rotating eccentric shaft (59) loosely extends into a center hole bearing (37) of the slide plate (27) to cause the oscillations.

Torsional Restraint Problem of Steel Cold-Formed Beams Restrained By Planar Members

NASA Astrophysics Data System (ADS)

Balázs, Ivan; Melcher, Jindřich; Pešek, Ondřej

2017-10-01

The effect of continuous or discrete lateral and torsional restraints of metal thinwalled members along their spans can positively influence their buckling resistance and thus contribute to more economical structural design. The prevention of displacement and rotation of the cross-section results in stabilization of the member. The restraints can practically be provided e.g. by planar members of cladding supported by metal members (purlins, girts). The rate of stabilization of a member can be quantified using values of shear and rotational stiffness provided by the adjacent planar members. While the lateral restraint effected by certain shear stiffness can be often considered as sufficient, the complete torsional restraint can be safely considered in some practical cases only. Otherwise the values of the appropriate rotational stiffness provided by adjacent planar members may not be satisfactory to ensure full torsional restraint and only incomplete restraint is available. Its verification should be performed using theoretical and experimental analyses. The paper focuses on problem of steel thin-walled coldformed beams stabilized by planar members and investigates the effect of the magnitude of the rotational stiffness provided by the planar members on the resistance of the steel members. Cold-formed steel beams supporting planar members of cladding are considered. Full lateral restraint and incomplete torsional restraint are assumed. Numerical analyses performed using a finite element method software indicate considerable influence of the torsional restraint on the buckling resistance of a steel thin-walled member. Utilization of the torsional restraint in the frame of sizing of a stabilized beam can result in more efficient structural design. The paper quantifies this effect for some selected cases and summarizes results of numerical analysis.

Spontaneous Planar Chiral Symmetry Breaking in Cells

NASA Astrophysics Data System (ADS)

Hadidjojo, Jeremy; Lubensky, David

Recent progress in animal development has highlighted the central role played by planar cell polarity (PCP) in epithelial tissue morphogenesis. Through PCP, cells have the ability to collectively polarize in the plane of the epithelium by localizing morphogenetic proteins along a certain axis. This allows direction-dependent modulation of tissue mechanical properties that can translate into the formation of complex, non-rotationally invariant shapes. Recent experimental observations[1] show that cells, in addition to being planar-polarized, can also spontaneously develop planar chirality, perhaps in the effort of making yet more complex shapes that are reflection non-invariant. In this talk we will present our work in characterizing general mechanisms that can lead to spontaneous chiral symmetry breaking in cells. We decompose interfacial concentration of polarity proteins in a hexagonal cell packing into irreducible representations. We find that in the case of polar concentration distributions, a chiral state can only be reached from a secondary instability after the cells are polarized. However in the case of nematic distributions, we show that a finite-amplitude (subcritical, or ``first-order'') nematic transition can send the system from disorder directly to a chiral state. In addition, we find that perturbing the system by stretching the hexagonal packing enables direct (supercritical, or ``second-order'') chiral transition in the nematic case. Finally, we do a Landau expansion to study competition between stretch-induced chirality and the tendency towards a non-chiral state in packings that have retained the full 6-fold symmetry.

Fast assessment of planar chromatographic layers quality using pulse thermovision method.

PubMed

Suszyński, Zbigniew; Świta, Robert; Loś, Joanna; Zarzycka, Magdalena B; Kaleniecka, Aleksandra; Zarzycki, Paweł K

2014-12-19

The main goal of this paper is to demonstrate capability of pulse thermovision (thermal-wave) methodology for sensitive detection of photothermal non-uniformities within light scattering and semi-transparent planar stationary phases. Successful visualization of stationary phases defects required signal processing protocols based on wavelet filtration, correlation analysis and k-means 3D segmentation. Such post-processing data handling approach allows extremely sensitive detection of thickness and structural changes within commercially available planar chromatographic layers. Particularly, a number of TLC and HPTLC stationary phases including silica, cellulose, aluminum oxide, polyamide and octadecylsilane coated with adsorbent layer ranging from 100 to 250μm were investigated. Presented detection protocol can be used as an efficient tool for fast screening the overall heterogeneity of any layered materials. Moreover, described procedure is very fast (few seconds including acquisition and data processing) and may be applied for fabrication processes online controlling. In spite of planar chromatographic plates this protocol can be used for assessment of different planar separation tools like paper based analytical devices or micro total analysis systems, consisted of organic and non-organic layers. Copyright © 2014 Elsevier B.V. All rights reserved.

Gibbs-Thomson Effect in Planar Nanowires: Orientation and Doping Modulated Growth.

PubMed

Shen, Youde; Chen, Renjie; Yu, Xuechao; Wang, Qijie; Jungjohann, Katherine L; Dayeh, Shadi A; Wu, Tom

2016-07-13

Epitaxy-enabled bottom-up synthesis of self-assembled planar nanowires via the vapor-liquid-solid mechanism is an emerging and promising approach toward large-scale direct integration of nanowire-based devices without postgrowth alignment. Here, by examining large assemblies of indium tin oxide nanowires on yttria-stabilized zirconia substrate, we demonstrate for the first time that the growth dynamics of planar nanowires follows a modified version of the Gibbs-Thomson mechanism, which has been known for the past decades to govern the correlations between thermodynamic supersaturation, growth speed, and nanowire morphology. Furthermore, the substrate orientation strongly influences the growth characteristics of epitaxial planar nanowires as opposed to impact at only the initial nucleation stage in the growth of vertical nanowires. The rich nanowire morphology can be described by a surface-energy-dependent growth model within the Gibbs-Thomson framework, which is further modulated by the tin doping concentration. Our experiments also reveal that the cutoff nanowire diameter depends on the substrate orientation and decreases with increasing tin doping concentration. These results enable a deeper understanding and control over the growth of planar nanowires, and the insights will help advance the fabrication of self-assembled nanowire devices.

The Sampling Issues in Quantitative Research

ERIC Educational Resources Information Center

Delice, Ali

2010-01-01

A concern for generalization dominates quantitative research. For generalizability and repeatability, identification of sample size is essential. The present study investigates 90 qualitative master's theses submitted for the Primary and Secondary School Science and Mathematics Education Departments, Mathematic Education Discipline in 10…

Shock-induced perturbation evolution in planar laser targets

NASA Astrophysics Data System (ADS)

Aglitskiy, Y.; Karasik, M.; Velikovich, A. L.; Serlin, V.; Weaver, J. L.; Kessler, T. J.; Schmitt, A. J.; Obenschain, S. P.; Metzler, N.; Oh, J.

2013-10-01

Experimental studies of hydrodynamic perturbation evolution triggered by a laser-driven shock wave in a planar target done on the KrF Nike laser facility are reported. The targets were made of solid plastic and/or plastic foam with single mode sinusoidal perturbation on the front or back surface or plastic/foam interface. Two specific cases are discussed. When a planar solid plastic target rippled at the front side is irradiated with a 350 ps long laser pulse, ablative Richtmyer-Meshkov (RM) oscillation of its areal mass modulation amplitude is detected while the laser is on, followed by observed strong oscillations of the areal mass in the unsupported shock flow after the laser pulse ends. When the target is rippled at the rear side, the nature of the perturbation evolution after the shock breakout is determined by the strength of the laser-driven shock wave. At pressure below 1 Mbar shock interaction with rear-surface ripples produces planar collimated jets manifesting the development of a classical RM instability in a weakly compressible shocked fluid. At shock pressure ~ 8 Mbar sufficient for vaporizing the shocked target material we observed instead the strong areal mass oscillations characteristic of a rippled centered rarefaction wave. Work supported by US DOE, Defense Programs.

Development of DOTA-Rituximab to be Labeled with 90Y for Radioimmunotherapy of B-cell Non-Hodgkin Lymphoma

PubMed Central

Johari doha, Fariba; Rahmani, Siyavash; Rikhtechi, Pedram; Rasaneh, Samira; Sheikholislam, Zahra; Shahhosseini, Soraya

2017-01-01

NHL is the most common hematologic cancer in adults. Rituximab is the FDA approved treatment of relapsed or refractory low grade B-cell Non-Hodgkin Lymphoma (NHL). But patients eventually become resistant to rituximab. Since lymphocytes and lymphoma cells are highly radiosensitive, low grade NHL that has relapsed or refractory to standard therapy is treated by RIT in which a beta-emitting radionuclide coupled to anti-CD20 antibody. The association of beta emitter radionuclide to rituximab enhances its therapeutic efficacy. The cells which lack antigen or cells which cannot be reached due to poor vascularization and intratumoral pressure in a bulky tumor would be irradiated and killed by cross fire effect of beta emitter. 90Y, a pure high energy β-emitter with a half-life of 64 h, a maximum energy of 2.28 MeV, and maximum board of 11.3 mm in tissue is radionuclide of choice for radioimmunotherapy of outpatient administration. In this study, rituximab was conjugated to DOTA and radiolabeled with 90YCl3. The stability, affinity, and immunoreactivity of radiolabeled antibody was determined in vitro and the conditions were optimized. Biodistribution studies were done in normal mice. The optimum conditions of conjugation and radiolabeling was 1-2 h at 37 °C and 1 h at 45 °C, respectively. Results showed approximately 4 DOTA molecules conjugated per antibody molecule. The purified antibody was stable and intact over 6 months stored at -20 °C. The result of immunoreactivity (≈70%), affinity (≈3 nM) and biodistribution in normal mice are acceptable. PMID:28979315

Model-Based Radiation Dose Correction for Yttrium-90 Microsphere Treatment of Liver Tumors With Central Necrosis

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

Liu, Ching-Sheng; Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Lin, Ko-Han

Purpose: The objectives of this study were to model and calculate the absorbed fraction {phi} of energy emitted from yttrium-90 ({sup 90}Y) microsphere treatment of necrotic liver tumors. Methods and Materials: The tumor necrosis model was proposed for the calculation of {phi} over the spherical shell region. Two approaches, the semianalytic method and the probabilistic method, were adopted. In the former method, the range--energy relationship and the sampling of electron paths were applied to calculate the energy deposition within the target region, using the straight-ahead and continuous-slowing-down approximation (CSDA) method. In the latter method, the Monte Carlo PENELOPE code wasmore » used to verify results from the first method. Results: The fraction of energy, {phi}, absorbed from {sup 90}Y by 1-cm thickness of tumor shell from microsphere distribution by CSDA with complete beta spectrum was 0.832 {+-} 0.001 and 0.833 {+-} 0.001 for smaller (r{sub T} = 5 cm) and larger (r{sub T} = 10 cm) tumors (where r is the radii of the tumor [T] and necrosis [N]). The fraction absorbed depended mainly on the thickness of the tumor necrosis configuration, rather than on tumor necrosis size. The maximal absorbed fraction {phi} that occurred in tumors without central necrosis for each size of tumor was different: 0.950 {+-} 0.000, and 0.975 {+-} 0.000 for smaller (r{sub T} = 5 cm) and larger (r{sub T} = 10 cm) tumors, respectively (p < 0.0001). Conclusions: The tumor necrosis model was developed for dose calculation of {sup 90}Y microsphere treatment of hepatic tumors with central necrosis. With this model, important information is provided regarding the absorbed fraction applicable to clinical {sup 90}Y microsphere treatment.« less

Enhanced and tunable electric dipole-dipole interactions near a planar metal film

NASA Astrophysics Data System (ADS)

Zhou, Lei-Ming; Yao, Pei-Jun; Zhao, Nan; Sun, Fang-Wen

2017-08-01

We investigate the enhanced electric dipole-dipole interaction of surface plasmon polaritons (SPPs) supported by a planar metal film waveguide. By taking two nitrogen-vacancy (NV) center electric dipoles in diamond as an example, both the coupling strength and collective relaxation of two dipoles are studied with the numerical Green Function method. Compared to two-dipole coupling on a planar surface, metal film provides stronger and tunable coupling coefficients. Enhancement of the interaction between coupled NV center dipoles could have applications in both quantum information and energy transfer investigation. Our investigation provides systematic results for experimental applications based on a dipole-dipole interaction mediated with SPPs on a planar metal film.

Planar Cell Polarity Pathway – Coordinating morphogenetic cell behaviors with embryonic polarity

PubMed Central

Gray, Ryan S.; Roszko, Isabelle; Solnica-Krezel, Lilianna

2011-01-01

Planar cell polarization entails establishment of cellular asymmetries within the tissue plane. An evolutionarily conserved Planar Cell Polarity (PCP) signaling system employs intra- and intercellular feedback interactions between its core components, including Frizzled, Van Gogh, Flamingo, Prickle and Dishevelled, to establish their characteristic asymmetric intracellular distributions and coordinate planar polarity of cell populations. By translating global patterning information into asymmetries of cell membranes and intracellular organelles, PCP signaling coordinates morphogenetic behaviors of individual cells and cell populations with the embryonic polarity. In vertebrates, by polarizing cilia in the node/Kupffer’s vesicle, PCP signaling links the anteroposterior to left-right embryonic polarity. PMID:21763613

Transfer-Efficient Face Routing Using the Planar Graphs of Neighbors in High Density WSNs

PubMed Central

Kim, Sang-Ha

2017-01-01

Face routing has been adopted in wireless sensor networks (WSNs) where topological changes occur frequently or maintaining full network information is difficult. For message forwarding in networks, a planar graph is used to prevent looping, and because long edges are removed by planarization and the resulting planar graph is composed of short edges, and messages are forwarded along multiple nodes connected by them even though they can be forwarded directly. To solve this, face routing using information on all nodes within 2-hop range was adopted to forward messages directly to the farthest node within radio range. However, as the density of the nodes increases, network performance plunges because message transfer nodes receive and process increased node information. To deal with this problem, we propose a new face routing using the planar graphs of neighboring nodes to improve transfer efficiency. It forwards a message directly to the farthest neighbor and reduces loads and processing time by distributing network graph construction and planarization to the neighbors. It also decreases the amount of location information to be transmitted by sending information on the planar graph nodes rather than on all neighboring nodes. Simulation results show that it significantly improves transfer efficiency. PMID:29053623

Quality control assurance of strontium-90 in foodstuffs by LSC.

PubMed

Lopes, I; Mourato, A; Abrantes, J; Carvalhal, G; Madruga, M J; Reis, M

2014-11-01

A method based on the separation of Sr-90 by extraction chromatography and beta determination by Liquid Scintillation Counting (LSC) technique was used for strontium analysis in food samples. The methodology consisted in prior sample treatment (drying and incineration) followed by radiochemical separation of Sr-90 by extraction chromatography, using the Sr-resin. The chemical yield was determined by gravimetric method, adding stable strontium to the matrix. Beta activity (Sr-90/Y-90) was determined using a low background liquid scintillation spectrometer (Tri-Carb 3170 TR/SL, Packard). The accuracy and the precision of the method, was performed previously through recovery trials with Sr-90 spiked samples, using the same type of matrices (milk, complete meals, meat and vegetables). A reference material (IAEA_321) was now used to measure the accuracy of the procedure. Participation in interlaboratory comparison exercises was also performed in order to establish an external control on the measurements and to ensure the adequacy of the method. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of Nomarski microscopy for quantitative determination of surface topography

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

Hartman, J. S.; Gordon, R. L.; Lessor, D. L.

1979-01-01

The use of Nomarski differential interference contrast (DIC) microscopy has been extended to provide nondestructive, quantitative analysis of a sample's surface topography. Theoretical modeling has determined the dependence of the image intensity on the microscope's optical components, the sample's optical properties, and the sample's surface orientation relative to the microscope. Results include expressions to allow the inversion of image intensity data to determine sample surface slopes. A commercial Nomarski system has been modified and characterized to allow the evaluation of the optical model. Data have been recorded with smooth, planar samples that verify the theoretical predictions.

Fabrication of small-scale structures with non-planar features

DOEpatents

Burckel, David B.; Ten Eyck, Gregory A.

2015-11-19

The fabrication of small-scale structures is disclosed. A unit-cell of a small-scale structure with non-planar features is fabricated by forming a membrane on a suitable material. A pattern is formed in the membrane and a portion of the substrate underneath the membrane is removed to form a cavity. Resonators are then directionally deposited on the wall or sides of the cavity. The cavity may be rotated during deposition to form closed-loop resonators. The resonators may be non-planar. The unit-cells can be formed in a layer that includes an array of unit-cells.

A Planar Hall Thruster for Investigating Electron Mobility in ExB Devices (Preprint)

DTIC Science & Technology

2007-08-24

Hall thruster that emits and collects the Hall current across a planar discharge channel is described. The planar Hall thruster (PHT) is being investigated for use as a test bed to study electron mobility in ExB devices. The planar geometry attempts to de-couple the complex electron motion found in annular thrusters by using simplified geometry. During this initial test, the PHT was operated at discharge voltages between 50-150 V to verify operability and stability of the device. Hall current was emitted by hollow cathode electron sources and

Planar embryos have poor prognosis in terms of blastocyst formation and implantation.

PubMed

Ebner, T; Maurer, M; Shebl, O; Moser, M; Mayer, R B; Duba, H C; Tews, G

2012-09-01

Normally, day-2 embryos show a crosswise arrangement of four cells with three blastomeres lying side by side. Cleavage anomalies include embryos that are characterized by a particular planar constellation of four blastomeres with presumed incomplete cleavage. Since little is known on the developmental fate of such conceptuses, within a 10-month period all consecutive patients were screened for day-2 planar embryos. A total of 64/2070 embryos with suboptimal blastomere configuration were detected (3.1%). In conventional IVF, planar embryos were significantly less frequent (0.7%) as compared with intracytoplasmic sperm injection (2.8%; P<0.05) and cases of testicular sperm extraction (5.4%; P<0.01). Interestingly, embryos with a cleavage anomaly showed better morphology both on day 2 (P<0.005) and day 3 (P<0.001). In contrast, blastocyst formation (P<0.001) and blastocyst quality (P=NS) was higher in tetrahedral embryos. There was a significant increase in implantation rate if tetrahedral embryos could be transferred compared with when planar embryos had to be transferred (P<0.01). It may be postulated that, in planar embryos, the mitotic spindle might have been affected, e.g. sperm centrosome composition or function, which in turn might have led to the observed cleavage anomaly. Normally, day-2 embryos show a crosswise arrangement of four cells with three blastomeres lying side by side. Cleavage anomalies include more planar embryos that are characterized by a particular flat constellation of four blastomeres with presumed premature cleavage (like a tetrafoliate clover). Since little is known on the developmental fate of such embryos within a 10-month study period, all consecutive patients were screened for the presence of day-2 planar embryos (study group). A total of 64 (out of 2070) embryos with abnormal blastomere configuration were detected (3.1%). Interestingly, in conventional IVF (0.7%), the presence of planar embryos was significantly less frequent as

A 5 meter range non-planar CMUT array for Automotive Collision Avoidance

NASA Astrophysics Data System (ADS)

Hernandez Aguirre, Jonathan

A discretized hyperbolic paraboloid geometry capacitive micromachined ultrasonic transducer (CMUT) array has been designed and fabricated for automotive collision avoidance. The array is designed to operate at 40 kHz, beamwidth of 40° with a maximum sidelobe intensity of -10dB. An SOI based fabrication technology has been used for the 5x5 array with 5 sensing surfaces along each x and y axis and 7 elevation levels. An assembly and packaging technique has been developed to realize the non-planar geometry in a PGA-68 package. A highly accurate mathematical method has been presented for analytical characterization of capacitive micromachined ultrasonic transducers (CMUTs) built with square diaphragms. The method uses a new two-dimensional polynomial function to more accurately predict the deflection curve of a multilayer square diaphragm subject to both mechanical and electrostatic pressure and a new capacitance model that takes into account the contribution of the fringing field capacitances.

Identifying Planar Deformation Features Using EBSD and FIB

NASA Astrophysics Data System (ADS)

Pickersgill, A. E.; Lee, M. R.

2015-09-01

Planar deformation features in quartz grains from the Gow Lake impact structure have been successfully identified and indexed using electron backscatter diffraction in combination with focused ion beam milling.

Motion video analysis using planar parallax

NASA Astrophysics Data System (ADS)

Sawhney, Harpreet S.

1994-04-01

Motion and structure analysis in video sequences can lead to efficient descriptions of objects and their motions. Interesting events in videos can be detected using such an analysis--for instance independent object motion when the camera itself is moving, figure-ground segregation based on the saliency of a structure compared to its surroundings. In this paper we present a method for 3D motion and structure analysis that uses a planar surface in the environment as a reference coordinate system to describe a video sequence. The motion in the video sequence is described as the motion of the reference plane, and the parallax motion of all the non-planar components of the scene. It is shown how this method simplifies the otherwise hard general 3D motion analysis problem. In addition, a natural coordinate system in the environment is used to describe the scene which can simplify motion based segmentation. This work is a part of an ongoing effort in our group towards video annotation and analysis for indexing and retrieval. Results from a demonstration system being developed are presented.

A magnetic resonance (MR) microscopy system using a microfluidically cryo-cooled planar coil.

PubMed

Koo, Chiwan; Godley, Richard F; Park, Jaewon; McDougall, Mary P; Wright, Steven M; Han, Arum

2011-07-07

We present the development of a microfluidically cryo-cooled planar coil for magnetic resonance (MR) microscopy. Cryogenically cooling radiofrequency (RF) coils for magnetic resonance imaging (MRI) can improve the signal to noise ratio (SNR) of the experiment. Conventional cryostats typically use a vacuum gap to keep samples to be imaged, especially biological samples, at or near room temperature during cryo-cooling. This limits how close a cryo-cooled coil can be placed to the sample. At the same time, a small coil-to-sample distance significantly improves the MR imaging capability due to the limited imaging depth of planar MR microcoils. These two conflicting requirements pose challenges to the use of cryo-cooling in MR microcoils. The use of a microfluidic based cryostat for localized cryo-cooling of MR microcoils is a step towards eliminating these constraints. The system presented here consists of planar receive-only coils with integrated cryo-cooling microfluidic channels underneath, and an imaging surface on top of the planar coils separated by a thin nitrogen gas gap. Polymer microfluidic channel structures fabricated through soft lithography processes were used to flow liquid nitrogen under the coils in order to cryo-cool the planar coils to liquid nitrogen temperature (-196 °C). Two unique features of the cryo-cooling system minimize the distance between the coil and the sample: (1) the small dimension of the polymer microfluidic channel enables localized cooling of the planar coils, while minimizing thermal effects on the nearby imaging surface. (2) The imaging surface is separated from the cryo-cooled planar coil by a thin gap through which nitrogen gas flows to thermally insulate the imaging surface, keeping it above 0 °C and preventing potential damage to biological samples. The localized cooling effect was validated by simulations, bench testing, and MR imaging experiments. Using this cryo-cooled planar coil system inside a 4.7 Tesla MR system

Method and apparatus for planar drag strip casting

DOEpatents

Powell, John C.; Campbell, Steven L.

1991-01-01

The present invention is directed to an improved process and apparatus for strip casting. The combination of a planar flow casting nozzle positioned back from the top dead center position with an attached nozzle extension, provides an increased level of casting control and quality. The nozzle extension provides a means of containing the molten pool above the rotating substrate to increase the control of molten metal at the edges of the strip and increase the range of coating thicknesses which may be produced. The level of molten metal in the containment means is regulated to be above the level of melt supplying the casting nozzle which produces a condition of planar drag flow with the casting substrate prior to solidification.

Method and apparatus for planar drag strip casting

DOEpatents

Powell, J.C.; Campbell, S.L.

1991-11-12

The present invention is directed to an improved process and apparatus for strip casting. The combination of a planar flow casting nozzle positioned back from the top dead center position with an attached nozzle extension, provides an increased level of casting control and quality. The nozzle extension provides a means of containing the molten pool above the rotating substrate to increase the control of molten metal at the edges of the strip and increase the range of coating thicknesses which may be produced. The level of molten metal in the containment means is regulated to be above the level of melt supplying the casting nozzle which produces a condition of planar drag flow with the casting substrate prior to solidification. 5 figures.

Breaking symmetry in non-planar bifurcations: distribution of flow and wall shear stress.

PubMed

Lu, Yiling; Lu, Xiyun; Zhuang, Lixian; Wang, Wen

2002-01-01

Non-planarity in blood vessels is known to influence arterial flows and wall shear stress. To gain insight, computational fluid dynamics (CFD) has been used to investigate effects of curvature and out-of-plane geometry on the distribution of fluid flows and wall shear stresses in a hypothetical non-planar bifurcation. Three-dimensional Navier-Stokes equations for a steady state Newtonian fluid were solved numerically using a finite element method. Non-planarity in one of the two daughter vessels is found to deflect flow from the inner wall of the vessel to the outer wall and to cause changes in the distribution of wall shear stresses. Results from this study agree to experimental observations and CFD simulations in the literature, and support the view that non-planarity in blood vessels is a factor with important haemodynamic significance and may play a key role in vascular biology and pathophysiology.

Diagnostic performance of semi-quantitative and quantitative stress CMR perfusion analysis: a meta-analysis.

PubMed

van Dijk, R; van Assen, M; Vliegenthart, R; de Bock, G H; van der Harst, P; Oudkerk, M

2017-11-27

Stress cardiovascular magnetic resonance (CMR) perfusion imaging is a promising modality for the evaluation of coronary artery disease (CAD) due to high spatial resolution and absence of radiation. Semi-quantitative and quantitative analysis of CMR perfusion are based on signal-intensity curves produced during the first-pass of gadolinium contrast. Multiple semi-quantitative and quantitative parameters have been introduced. Diagnostic performance of these parameters varies extensively among studies and standardized protocols are lacking. This study aims to determine the diagnostic accuracy of semi- quantitative and quantitative CMR perfusion parameters, compared to multiple reference standards. Pubmed, WebOfScience, and Embase were systematically searched using predefined criteria (3272 articles). A check for duplicates was performed (1967 articles). Eligibility and relevance of the articles was determined by two reviewers using pre-defined criteria. The primary data extraction was performed independently by two researchers with the use of a predefined template. Differences in extracted data were resolved by discussion between the two researchers. The quality of the included studies was assessed using the 'Quality Assessment of Diagnostic Accuracy Studies Tool' (QUADAS-2). True positives, false positives, true negatives, and false negatives were subtracted/calculated from the articles. The principal summary measures used to assess diagnostic accuracy were sensitivity, specificity, andarea under the receiver operating curve (AUC). Data was pooled according to analysis territory, reference standard and perfusion parameter. Twenty-two articles were eligible based on the predefined study eligibility criteria. The pooled diagnostic accuracy for segment-, territory- and patient-based analyses showed good diagnostic performance with sensitivity of 0.88, 0.82, and 0.83, specificity of 0.72, 0.83, and 0.76 and AUC of 0.90, 0.84, and 0.87, respectively. In per territory

Quantitation of Met tyrosine phosphorylation using MRM-MS.

PubMed

Meng, Zhaojing; Srivastava, Apurva K; Zhou, Ming; Veenstra, Timothy

2013-01-01

Phosphorylation has long been accepted as a key cellular regulator of cell signaling pathways. The recent development of multiple-reaction monitoring mass spectrometry (MRM-MS) provides a useful tool for measuring the absolute quantity of phosphorylation occupancy at pivotal sites within signaling proteins, even when the phosphorylation sites are in close proximity. Here, we described a targeted quantitation approach to measure the absolute phosphorylation occupancy at Y1234 and Y1235 of Met. The approach is utilized to obtain absolute occupancy of the two phosphorylation sites in the full-length recombinant Met. It is further applied to quantitate the phosphorylation state of these two sites in SNU-5 cells treated with a Met inhibitor.

A comparison of 30-day versus 90-day proton pump inhibitor therapy in prevention of marginal ulcers after laparoscopic Roux-en-Y gastric bypass.

PubMed

Kang, Xian; Zurita-Macias, Luis; Hong, Dennis; Cadeddu, Margherita; Anvari, Mehran; Gmora, Scott

2016-06-01

Marginal ulceration is one of the most common complications after laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery. Proton pump inhibitors (PPIs) are commonly administered to decrease the incidence of marginal ulcer development. We examine the differential impact of employing a 30-day versus 90-day postoperative PPI regimen on the development of marginal ulceration after LRYGB. University hospital. A retrospective cohort design was used to study all patients undergoing LRYGB at a single, high-volume bariatric center in Hamilton, Ontario, Canada. Three years previously, the duration of postoperative PPI administration was increased at our center from 30 to 90 days. Diagnosis of marginal ulceration was confirmed by upper endoscopy in patients presenting with epigastric pain and a clinical history suggestive of marginal ulceration. A χ(2) test of independence was performed to examine incidence of marginal ulceration and PPI duration. A total of 1016 patients underwent LRYGB at our center between January 2009 and January 2013. No differences in baseline characteristics were observed between groups. Of the 1016 patients followed, 614 received 30 days of PPI therapy and 402 received 90 days of PPI therapy. The incidence of marginal ulceration after LRYGB decreased significantly (P<.05) among patients receiving daily PPI for 90 days (n = 26, 6.5%) compared with those receiving PPI for 30 days (n = 76, 12.4%). This study suggests a significant benefit to longer duration prophylactic PPI administration after gastric bypass surgery to minimize the risk of symptomatic marginal ulceration. Copyright © 2016 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Identification, expression and phylogenetic analysis of EgG1Y162 from Echinococcus granulosus.

PubMed

Zhang, Fengbo; Ma, Xiumin; Zhu, Yuejie; Wang, Hongying; Liu, Xianfei; Zhu, Min; Ma, Haimei; Wen, Hao; Fan, Haining; Ding, Jianbing

2014-01-01

This study was to clone, identify and analyze the characteristics of egG1Y162 gene from Echinococcus granulosus. Genomic DNA and total RNAs were extracted from four different developmental stages of protoscolex, germinal layer, adult and egg of Echinococcus granulosus, respectively. Fluorescent quantitative PCR was used for analyzing the expression of egG1Y162 gene. Prokaryotic expression plasmid of pET41a-EgG1Y162 was constructed to express recombinant His-EgG1Y162 antigen. Western blot analysis was performed to detect antigenicity of EgG1Y162 antigen. Gene sequence, amino acid alignment and phylogenetic tree of EgG1Y162 were analyzed by BLAST, online Spidey and MEGA4 software, respectively. EgG1Y162 gene was expressed in four developmental stages of Echinococcus granulosus. And, egG1Y162 gene expression was the highest in the adult stage, with the relative value of 19.526, significantly higher than other three stages. Additionally, Western blot analysis revealed that EgG1Y162 recombinant protein had good reaction with serum samples from Echinococcus granulosus infected human and dog. Moreover, EgG1Y162 antigen was phylogenetically closest to EmY162 antigen, with the similarity over 90%. Our study identified EgG1Y162 antigen in Echinococcus granulosus for the first time. EgG1Y162 antigen had a high similarity with EmY162 antigen, with the genetic differences mainly existing in the intron region. And, EgG1Y162 recombinant protein showed good antigenicity.

Identification, expression and phylogenetic analysis of EgG1Y162 from Echinococcus granulosus

PubMed Central

Zhang, Fengbo; Ma, Xiumin; Zhu, Yuejie; Wang, Hongying; Liu, Xianfei; Zhu, Min; Ma, Haimei; Wen, Hao; Fan, Haining; Ding, Jianbing

2014-01-01

Objective: This study was to clone, identify and analyze the characteristics of egG1Y162 gene from Echinococcus granulosus. Methods: Genomic DNA and total RNAs were extracted from four different developmental stages of protoscolex, germinal layer, adult and egg of Echinococcus granulosus, respectively. Fluorescent quantitative PCR was used for analyzing the expression of egG1Y162 gene. Prokaryotic expression plasmid of pET41a-EgG1Y162 was constructed to express recombinant His-EgG1Y162 antigen. Western blot analysis was performed to detect antigenicity of EgG1Y162 antigen. Gene sequence, amino acid alignment and phylogenetic tree of EgG1Y162 were analyzed by BLAST, online Spidey and MEGA4 software, respectively. Results: EgG1Y162 gene was expressed in four developmental stages of Echinococcus granulosus. And, egG1Y162 gene expression was the highest in the adult stage, with the relative value of 19.526, significantly higher than other three stages. Additionally, Western blot analysis revealed that EgG1Y162 recombinant protein had good reaction with serum samples from Echinococcus granulosus infected human and dog. Moreover, EgG1Y162 antigen was phylogenetically closest to EmY162 antigen, with the similarity over 90%. Conclusion: Our study identified EgG1Y162 antigen in Echinococcus granulosus for the first time. EgG1Y162 antigen had a high similarity with EmY162 antigen, with the genetic differences mainly existing in the intron region. And, EgG1Y162 recombinant protein showed good antigenicity. PMID:25337206

Planar-Structure Perovskite Solar Cells with Efficiency beyond 21.

PubMed

Jiang, Qi; Chu, Zema; Wang, Pengyang; Yang, Xiaolei; Liu, Heng; Wang, Ye; Yin, Zhigang; Wu, Jinliang; Zhang, Xingwang; You, Jingbi

2017-12-01

Low temperature solution processed planar-structure perovskite solar cells gain great attention recently, while their power conversions are still lower than that of high temperature mesoporous counterpart. Previous reports are mainly focused on perovskite morphology control and interface engineering to improve performance. Here, this study systematically investigates the effect of precise stoichiometry, especially the PbI 2 contents on device performance including efficiency, hysteresis and stability. This study finds that a moderate residual of PbI 2 can deliver stable and high efficiency of solar cells without hysteresis, while too much residual PbI 2 will lead to serious hysteresis and poor transit stability. Solar cells with the efficiencies of 21.6% in small size (0.0737 cm 2 ) and 20.1% in large size (1 cm 2 ) with moderate residual PbI 2 in perovskite layer are obtained. The certificated efficiency for small size shows the efficiency of 20.9%, which is the highest efficiency ever recorded in planar-structure perovskite solar cells, showing the planar-structure perovskite solar cells are very promising. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An experimental study of the aerodynamic characteristics of planar and non-planar outboard wing planforms

NASA Technical Reports Server (NTRS)

Naik, D. A.; Ostowari, C.

1987-01-01

A series of wind tunnel experiments have been conducted to investigate the aerodynamic characteristics of several planar and nonplanar wingtip planforms. Seven different configurations: base-line rectangular, elliptical, swept and tapered, swept and tapered with dihedral, swept and tapered with anhedral, rising arc, and drooping arc, were investigated for two different spans. The data are available in terms of coefficient plots of force data, flow visualization photographs, and velocity and pressure flowfield surveys. All planforms, particularly the nonplanar, have some advantages over the baseline rectangular planform. Span efficiencies up to 20-percent greater than baseline are a possibility. However, it is suggested that the span efficiency concept might need refinement for nonplanar wings. Flow survey data show the change in effective span with vortex roll-up. The flow visualization shows the occurrence of mushroom-cell-separation flow patterns at angles of attack corresponding to stall. These grow with an increase in post-stall angle of attack. For the larger aspect ratios, the cells are observed to split into sub-cells at the higher angles of attack. For all angles of attack, some amount of secondary vortex flow is observed for the planar and nonplanar out-board planforms with sweep and taper.

Gibbs–Thomson Effect in Planar Nanowires: Orientation and Doping Modulated Growth

DOE PAGES

Shen, Youde; Chen, Renjie; Yu, Xuechao; ...

2016-06-02

Epitaxy-enabled bottom-up synthesis of self-assembled planar nanowires via the vapor–liquid–solid mechanism is an emerging and promising approach toward large-scale direct integration of nanowire-based devices without postgrowth alignment. In this paper, by examining large assemblies of indium tin oxide nanowires on yttria-stabilized zirconia substrate, we demonstrate for the first time that the growth dynamics of planar nanowires follows a modified version of the Gibbs–Thomson mechanism, which has been known for the past decades to govern the correlations between thermodynamic supersaturation, growth speed, and nanowire morphology. Furthermore, the substrate orientation strongly influences the growth characteristics of epitaxial planar nanowires as opposed tomore » impact at only the initial nucleation stage in the growth of vertical nanowires. The rich nanowire morphology can be described by a surface-energy-dependent growth model within the Gibbs–Thomson framework, which is further modulated by the tin doping concentration. Our experiments also reveal that the cutoff nanowire diameter depends on the substrate orientation and decreases with increasing tin doping concentration. Finally, these results enable a deeper understanding and control over the growth of planar nanowires, and the insights will help advance the fabrication of self-assembled nanowire devices.« less

Saturation pulse design for quantitative myocardial T1 mapping.

PubMed

Chow, Kelvin; Kellman, Peter; Spottiswoode, Bruce S; Nielles-Vallespin, Sonia; Arai, Andrew E; Salerno, Michael; Thompson, Richard B

2015-10-01

Quantitative saturation-recovery based T1 mapping sequences are less sensitive to systematic errors than the Modified Look-Locker Inversion recovery (MOLLI) technique but require high performance saturation pulses. We propose to optimize adiabatic and pulse train saturation pulses for quantitative T1 mapping to have <1 % absolute residual longitudinal magnetization (|MZ/M0|) over ranges of B0 and [Formula: see text] (B1 scale factor) inhomogeneity found at 1.5 T and 3 T. Design parameters for an adiabatic BIR4-90 pulse were optimized for improved performance within 1.5 T B0 (±120 Hz) and [Formula: see text] (0.7-1.0) ranges. Flip angles in hard pulse trains of 3-6 pulses were optimized for 1.5 T and 3 T, with consideration of T1 values, field inhomogeneities (B0 = ±240 Hz and [Formula: see text]=0.4-1.2 at 3 T), and maximum achievable B1 field strength. Residual MZ/M0 was simulated and measured experimentally for current standard and optimized saturation pulses in phantoms and in-vivo human studies. T1 maps were acquired at 3 T in human subjects and a swine using a SAturation recovery single-SHot Acquisition (SASHA) technique with a standard 90°-90°-90° and an optimized 6-pulse train. Measured residual MZ/M0 in phantoms had excellent agreement with simulations over a wide range of B0 and [Formula: see text]. The optimized BIR4-90 reduced the maximum residual |MZ/M0| to <1 %, a 5.8× reduction compared to a reference BIR4-90. An optimized 3-pulse train achieved a maximum residual |MZ/M0| <1 % for the 1.5 T optimization range compared to 11.3 % for a standard 90°-90°-90° pulse train, while a 6-pulse train met this target for the wider 3 T ranges of B0 and [Formula: see text]. The 6-pulse train demonstrated more uniform saturation across both the myocardium and entire field of view than other saturation pulses in human studies. T1 maps were more spatially homogeneous with 6-pulse train SASHA than the reference 90°-90°-90° SASHA in both

A planar comparison of actuators for vibration control of flexible structures

NASA Technical Reports Server (NTRS)

Clark, William W.; Robertshaw, Harry H.; Warrington, Thomas J.

1989-01-01

The methods and results of an analytical study comparing the effectiveness of four actuators in damping the vibrations of a planar clamped-free beam are presented. The actuators studied are two inertia-type actuators, the proof mass and reaction wheel, and two variable geometry trusses, the planar truss and the planar truss proof mass (a combination variable geometry truss/inertia-type actuator). Actuator parameters used in the models were chosen based on the results of a parametric study. A full-state, LQR optimal feedback control law was used for control in each system. Numerical simulations of each beam/actuator system were performed in response to initial condition inputs. These simulations provided information such as time response of the closed-loop system and damping provided to the beam. This information can be used to determine the 'best' actuator for a given purpose.

Geometrically induced surface polaritons in planar nanostructured metallic cavities

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

Davids, P. S.; Intravia, F; Dalvit, Diego A.

2014-01-14

We examine the modal structure and dispersion of periodically nanostructured planar metallic cavities within the scattering matrix formulation. By nanostructuring a metallic grating in a planar cavity, artificial surface excitations or spoof plasmon modes are induced with dispersion determined by the periodicity and geometric characteristics of the grating. These spoof surface plasmon modes are shown to give rise to new cavity polaritonic modes at short mirror separations that modify the density of modes in nanostructured cavities. The increased modal density of states form cavity polarirons have a large impact on the fluctuation induced electromagnetic forces and enhanced hear transfer atmore » short separations.« less

Resonance transparency with low-loss in toroidal planar metamaterial

NASA Astrophysics Data System (ADS)

Xiang, Tianyu; Lei, Tao; Hu, Sen; Chen, Jiao; Huang, Xiaojun; Yang, Helin

2018-03-01

A compact planar construction composed of asymmetric split ring resonators was designed with a low-loss, high Q-factor resonance transparency at microwave frequency. The singularity property of the proposed metamaterial owing to the enhanced toroidal dipole T is demonstrated via numerical and experimental methods. The transmission peak can reach up to 0.91 and the loss is perfectly repressed, which can be testified by radiated power, H-field distributions, and the imaginary parts of effective permittivity and permeability. The designed planar metamaterial may have numerous potential applications at microwave, terahertz, and optical frequency, e.g., for ultrasensitive sensing, slow-light devices, lasing spacers, even invisible information transfer.

Experimental investigation of non-planar sheared outboard wing planforms

NASA Technical Reports Server (NTRS)

Naik, D. A.; Ostowari, C.

1988-01-01

The outboard planforms of wings have been found to be of prime importance in studies of induced drag reduction. This conclusion is based on an experimental and theoretical study of the aerodynamic characteristics of planar and nonplanar outboard wing forms. Six different configurations; baseline rectangular, planar sheared, sheared with dihedral, sheared with anhedral, rising arc, and drooping arc were investigated for two different spans. Span efficiencies as much as 20 percent greater than baseline can be realized with nonplanar wing forms. Optimization studies show that this advantage can be achieved along with a bending moment benefit. Parasite drag and lateral stability estimations were not included in the analysis.

Safety of {sup 90}Y Radioembolization in Patients Who Have Undergone Previous External Beam Radiation Therapy

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

Lam, Marnix G.E.H.; Department of Radiology and Nuclear Medicine, University Medical Center Utrecht; Abdelmaksoud, Mohamed H.K.

2013-10-01

Purpose: Previous external beam radiation therapy (EBRT) is theoretically contraindicated for yttrium-90 ({sup 90}Y) radioembolization (RE) because the liver has a lifetime tolerance to radiation before becoming vulnerable to radiation-induced liver disease. We analyzed the safety of RE as salvage treatment in patients who had previously undergone EBRT. Methods and Materials: Between June 2004 and December 2010, a total of 31 patients who had previously undergone EBRT were treated with RE. Three-dimensional treatment planning with dose–volume histogram (DVH) analysis of the liver was used to calculate the EBRT liver dose. Liver-related toxicities including RE-induced liver disease (REILD) were reviewed andmore » classified according to Common Terminology Criteria for Adverse Events version 4.02. Results: The mean EBRT and RE liver doses were 4.40 Gy (range, 0-23.13 Gy) and 57.9 Gy (range, 27.0-125.9 Gy), respectively. Patients who experienced hepatotoxicity (≥grade2; n=12) had higher EBRT mean liver doses (7.96 ± 8.55 Gy vs 1.62 ± 3.39 Gy; P=.037), the only independent predictor in multivariate analysis. DVH analysis showed that the fraction of liver exposed to ≥30 Gy (V30) was the strongest predictor of hepatotoxicity (10.14% ± 12.75% vs 0.84% ± 3.24%; P=.006). All patients with V30 >13% experienced hepatotoxicity. Fatal REILD (n=2) occurred at the 2 highest EBRT mean liver doses (20.9 Gy and 23.1 Gy) but also at the highest cumulative liver doses (91.8 Gy and 149 Gy). Conclusions: Prior exposure of the liver to EBRT may lead to increased liver toxicity after RE treatment, depending on fractional liver exposure and dose level. The V30 was the strongest predictor of toxicity. RE appears to be safe for the treatment of hepatic malignancies only in patients who have had limited hepatic exposure to prior EBRT.« less

Planar CoB18- Cluster: a New Motif for - and Metallo-Borophenes

NASA Astrophysics Data System (ADS)

Chen, Teng-Teng; Jian, Tian; Lopez, Gary; Li, Wan-Lu; Chen, Xin; Li, Jun; Wang, Lai-Sheng

2016-06-01

Combined Photoelectron Spectroscopy (PES) and theoretical calculations have found that anion boron clusters (Bn-) are planar and quasi-planar up to B25-. Recent works show that anion pure boron clusters continued to be planar at B27-,B30-,B35- and B36-. B35- and B36- provide the first experimental evidence for the viability of the two-dimensional (2D) boron sheets (Borophene). The 2D to three-dimensional (3D) transitions are shown to happen at B40-,B39- and B28-, which possess cage-like structures. These fullerene-like boron cage clusters are named as Borospherene. Recently, borophenes or similar structures are claimed to be synthesized by several groups. Following an electronic design principle, a series of transition-metal-doped boron clusters (M©Bn-, n=8-10) are found to possess the monocyclic wheel structures. Meanwhile, CoB12- and RhB12- are revealed to adopt half-sandwich-type structures with the quasi-planar B12 moiety similar to the B12- cluster. Very lately, we show that the CoB16- cluster possesses a highly symmetric Cobalt-centered drum-like structure, with a new record of coordination number at 16. Here we report the CoB18- cluster to possess a unique planar structure, in which the Co atom is doped into the network of a planar boron cluster. PES reveals that the CoB18- cluster is a highly stable electronic system with the first adiabatic detachment energy (ADE) at 4.0 eV. Global minimum searches along with high-level quantum calculations show the global minimum for CoB18- is perfectly planar and closed shell (1A1) with C2v symmetry. The Co atom is bonded with 7 boron atoms in the closest coordination shell and the other 11 boron atoms in the outer coordination shell. The calculated vertical detachment energy (VDE) values match quite well with our experimental results. Chemical bonding analysis by the Adaptive Natural Density Partitioning (AdNDP) method shows the CoB18- cluster is π-aromatic with four 4-centered-2-electron (4c-2e) π bonds and one 19

Gender Differences in Isokinetic Strength after 60 and 90 d Bed Rest

NASA Technical Reports Server (NTRS)

English, K. L.; Ploutz-Snyder, R. J.; Cromwell, R. L.; Ploutz-Snyder, L. L.

2010-01-01

Recent reports suggest that changes in muscle strength following disuse may differ between males and females. PURPOSE: To examine potential gender differences in strength changes following 60 and 90 d of experimental bed rest. METHODS: Isokinetic extensor and flexor strength of the knee (60deg and 180deg/s, concentric only), ankle (30deg/s, concentric and eccentric), and trunk (60deg/s, concentric only) were measured following 60 d (males: n=4, 34.5+/-9.6 y; females: n=4, 35.5+/-8.2 y) and 90 d (males: n=10, 31.4+/-4.8 y; females: n=5, 37.6+/-9.9 y) of 6-degree head-down-tilt bed rest (BR; N=23). Subjects were fed a controlled diet (55%/15%/ 30%, CHO/PRO/FAT) that maintained body weight within 3% of the weight recorded on Day 3 of bed rest. After a familiarization session, testing was conducted 6 d before BR and 2 d after BR completion. Peak torque and total work were calculated for the tests performed. To allow us to combine data from both 60- and 90-d subjects, we used a mixed-model statistical analysis in which time and gender were fixed effects and bed rest duration was a random effect. Log-transformations of strength measures were utilized when necessary in order to meet statistical assumptions. RESULTS: Main effects were seen for both time and gender (p<0.05), showing decreased strength in response to bed rest for both males and females, and males stronger than females for most strength measures. Only one interaction effect was observed: females exhibited a greater loss of trunk extensor peak torque at 60 d versus pre-BR, relative to males (p=0.004). CONCLUSION: Sixty and 90 d of BR induced significant losses in isokinetic muscle strength of the locomotor and postural muscles of the knee, ankle, and trunk. Although males were stronger than females for most of the strength measures that we examined, only changes in trunk extensor peak torque were greater for females than males at day 60 of bed rest

Planar optical waveguides for optical panel having gradient refractive index core

DOEpatents

Veligdan, James T.

2001-01-01

An optical panel is disclosed. A plurality of stacked planar optical waveguides are used to guide light from an inlet face to an outlet face of an optical panel. Each of the optical waveguides comprises a planar sheet of core material having a central plane. The core material has an index of refraction which decreases as the distance from the central plane increases. The decrease in the index of refraction occurs gradually and continuously.

Planar optical waveguides for optical panel having gradient refractive index core

DOEpatents

Veligdan, James T.

2004-08-24

An optical panel is disclosed. A plurality of stacked planar optical waveguides are used to guide light from an inlet face to an outlet face of an optical panel. Each of the optical waveguides comprises a planar sheet of core material having a central plane. The core material has an index of refraction which decreases as the distance from the central plane increases. The decrease in the index of refraction occurs gradually and continuously.

A comparative quantitative analysis of magnetic susceptibility artifacts in echo planar and PROPELLER diffusion-weighted images

NASA Astrophysics Data System (ADS)

Cho, Jae-Hwan; Lee, Hae-Kag; Yang, Han-Joon; Lee, Gui-Won; Park, Yong-Soon; Chung, Woon-Kwan

2013-01-01

In this study, the authors investigated whether periodically-rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) diffusion-weighted imaging (DWI) can remove magnetic susceptibility artifacts and compared apparent diffusion coefficient (ADC) values for PROPELLER DWI and the common echo planar (EP) DWI. Twenty patients that underwent brain MRI with a metal dental implant were selected. A 3.0T MR scanner was then used to obtain EP DWI, PROPELLER DWI, and corresponding apparent diffusion coefficient (ADC) maps for a b-value of 0 and 1,000 s/mm2. The frequencies of magnetic susceptibility artifacts in four parts of the brain (bilateral temporal lobes, pons, and orbit) were selected. In the ADC maps, we measured the ADC values of both sides of the temporal lobe and the pons. According to the study results, the frequency of magnetic susceptibility artifacts in PROPELLER DW images was lower than it was in EP DW images. In ADC maps, the ADC values of the bilateral temporal lobes and the pons were all higher in PROPELLER ADC maps than in EP ADC maps. Our findings show that when a high-field MRI machine is used, magnetic susceptibility artifacts can distort anatomical structures and produce high-intensity signals. Furthermore, our findings suggest that in many cases, PROPELLER DWI would be helpful in terms of achieving a correct diagnosis.

A ten-element array of individually addressable channeled-substrate-planar AlGaAs diode lasers

NASA Technical Reports Server (NTRS)

Carlin, D. B.; Goldstein, B.; Bednarz, J. P.; Harvey, M. G.; Dinkel, N. A.

1987-01-01

The fabrication of arrays of channeled-substrate-planar (CSP) AlGaAs diode lasers which emit up to 150 mW CW in a single spatial mode and are applicable to mulitchannel optical recording systems is described. The CSP diode lasers are incorporated in ten-array geometry, and each array is 1.95 nm in width and 100 microns in thickness and is cleaved to have a cavity length of 200 microns and coated to produce 90-percent reflectivity on the back facet and 10-percent reflectivity on the front facet. The array is attached to a thermoelectrically cooled submount. The optical output power versus input current characteristics for the array are evaluated, and the lateral far-field intensity profiles for each of the lasers (at 30 mW CW) and CW spectra of the lasers are analyzed.

Defect images by planar ECT probe of meander-mesh coils

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

Yamada, Sotoshi; Katou, Masaki; Iwahara, Masayoshi

1996-09-01

This paper presents results pertaining to image data obtained from a planar meander-mesh coupled coil type ECT probe. The image data makes it possible to detect not only the existence of a defect but also to extract detailed information regarding the nature of the defect, such as its position, shape, length, and direction. In order to recognize a defect distinctly, the authors have fabricated the high sensitive planar coil which can be used to image a 2-D representation of the ECT signal. The relationships between the image pattern and defect shape are discussed.

Efficacy of 67 gallium ECT imaging in lymphoma, infection, and lung carcinoma: A comparison with planar imaging

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

Harwood, S.J.; Anderson, M.W.; Klein, R.C.

1984-01-01

Emission computed tomography (ECT) studies were performed on a GE 400 A/T camera and ADAC computers (system 3 and system 3300). Thirty-three sets of ECT and planar images were obtained in 20 patients over a six month period. Imaging was performed 48 hours after the intravenous administration of 5 mc of Gallium 67 citrate. No bowel preparation was employed. Comparison is made of the initial nuclear medicine report derived from planar and ECT imaging aided by clinical knowledge versus the consensus opinion of two nuclear medicine physicians reading the planar images along with minimal clinical information. The lymphoma series consistsmore » of 18 scans in 10 patients. There were 5 scans in which a false negative planar interpretation was changed to a true positive ECT interpretation. Sensitivity of planar imaging for lymphoma was 58% which rose to 100% with addition of ECT information. There were no false positives by either technique. There were 5 sets of scans in 5 lung carcinoma patients. Sensitivity of the planar images was 60% because of 2 false negative results. Sensitivity of the ECT technique was 100%. There were no false positives. The infection series consists of 10 scans in 5 patients. Sensitivity of ECT was 100%, sensitivity of planar was 66%. There was 1 false positive planar. For the total series the accuracy of planar imaging was 69% and the predictive value of a negative planar interpretation was 44%. Corresponding values for ECT imaging were 100%. The authors' experience demonstrates significant increase in sensitivity without loss of specificity resulting from the use of Emission Computed Tomography in both chest and abdomen in patients with lymphoma, infection, and lung cancer.« less

Soft tissue tumors among beagles injected with 90Sr, 228Ra, OR 228Th.

PubMed

Lloyd, R D; Angus, W; Taylor, G N; Miller, S C

1995-08-01

The occurrence of soft-tissue tumors in beagles given 90Sr (88 dogs), 228Ra (76 dogs), or 228Th (81 dogs) as young adults and followed throughout their lifespans was compared with that of 133 control beagles given no radioactivity. For animals injected with 228Ra, tumors of the eye were more prominent (p < 0.05) than in the controls, and soft-tissue tumors of cavities in the head (excluding the brain, mouth, and eye) were more prominent in dogs given 90Sr than in the controls (p < 0.05). There was some indication that eye tumors in animals given about 0.56 kBq 228Th kg-1 were associated with their radionuclide exposure. For tumors at a few other locations, the relative occurrence was greater (p < 0.05) in the controls. These included malignant tumors of the testis and malignant plus benign tumors of the mammae and vagina in 228Th dogs; both malignant and malignant plus benign tumors of the mouth and testis, and malignant plus benign tumors of the mammae and vagina in 228Ra dogs; and malignant plus benign tumors of the mammae in 90Sr dogs (p > 0.05 by Odds Ratio Chi Square analysis but p < 0.05 by Fisher's Exact Test). Differences in relative occurrence between radioactive dogs and controls of all other tumor types that appeared in any of the animals (notably lymphosarcoma, lymph node tumors, leukemia, mast cell tumors, liver tumors, etc.) were not statistically significant (p > 0.05). Intercurrent mortality, mainly from bone cancer, was higher in the radioactive dogs than in the controls. Mean survival was reduced in the dogs given 90Sr, 228Ra, or 228Th (13.17 +/- 2.64 y in controls, 10.95 +/- 4.06 y in 90Sr dogs, 9.07 +/- 3.61 y in 228Ra dogs, and 9.20 +/- 4.15 y in 228Th dogs). Attenuated lifespans could account, at least in part, for the relative paucity of soft-tissue tumors not induced by radiation among the groups of dogs given radioactivity and occurring near the end of life for control animals.

The Evolution of Ih C_60 Vibrational Modes in Planar Polymerized C_60.

NASA Astrophysics Data System (ADS)

Adams, G. B.; Page, J. B.

2001-03-01

We have used first-principles local-orbital-based molecular dynamics(O.F. Sankey and D.J. Niklewski, Phys. Rev. B40), 3979 (1989). to simulate a wide variety of planar polymers of C_60, including the orthorhombic (O), tetrahedral (T), and rhombohedral (R) polymers which have been reported experimentally. It has been customary to assume that the vibrational modes of the polymers are moderately perturbed Ih C_60 vibrational modes.(See, for example V.A. Davydov et al.), Phys. Rev. B61, 11936 (2000) or V.C. Long et al., Phys. Rev. B 61, 13191 (2000). To test this assumption, we have expanded the polymer vibrational eigenvectors in the eigenvectors of Ih C_60, thus determining quantitatively the percentage contribution of each Ih C_60 mode to each polymer vibrational mode. We find that for many polymer modes the assumption is not justified. We report our results for selected Raman- and IR-active vibrational modes of the observed polymers.

Recent Advances in the Inverted Planar Structure of Perovskite Solar Cells.

PubMed

Meng, Lei; You, Jingbi; Guo, Tzung-Fang; Yang, Yang

2016-01-19

Inorganic-organic hybrid perovskite solar cells research could be traced back to 2009, and initially showed 3.8% efficiency. After 6 years of efforts, the efficiency has been pushed to 20.1%. The pace of development was much faster than that of any type of solar cell technology. In addition to high efficiency, the device fabrication is a low-cost solution process. Due to these advantages, a large number of scientists have been immersed into this promising area. In the past 6 years, much of the research on perovskite solar cells has been focused on planar and mesoporous device structures employing an n-type TiO2 layer as the bottom electron transport layer. These architectures have achieved champion device efficiencies. However, they still possess unwanted features. Mesoporous structures require a high temperature (>450 °C) sintering process for the TiO2 scaffold, which will increase the cost and also not be compatible with flexible substrates. While the planar structures based on TiO2 (regular structure) usually suffer from a large degree of J-V hysteresis. Recently, another emerging structure, referred to as an "inverted" planar device structure (i.e., p-i-n), uses p-type and n-type materials as bottom and top charge transport layers, respectively. This structure derived from organic solar cells, and the charge transport layers used in organic photovoltaics were successfully transferred into perovskite solar cells. The p-i-n structure of perovskite solar cells has shown efficiencies as high as 18%, lower temperature processing, flexibility, and, furthermore, negligible J-V hysteresis effects. In this Account, we will provide a comprehensive comparison of the mesoporous and planar structures, and also the regular and inverted of planar structures. Later, we will focus the discussion on the development of the inverted planar structure of perovskite solar cells, including film growth, band alignment, stability, and hysteresis. In the film growth part, several

COMPUTER ANALYSIS OF PLANAR GAMMA CAMERA IMAGES

EPA Science Inventory

COMPUTER ANALYSIS OF PLANAR GAMMA CAMERA IMAGES

T Martonen1 and J Schroeter2

1Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. EPA, Research Triangle Park, NC 27711 USA and 2Curriculum in Toxicology, Unive...

Detecting Planar Surfaces in Outdoor Urban Environments

DTIC Science & Technology

2008-09-01

coplanar or parallel scene points and lines. Sturm and Maybank (18) perform 3D reconstruction given user-provided coplanarity, perpendicularity, and... Maybank , S. J. A method for intactive 3d reconstruction of piercewise planar objects from single images. in BMVC, 1999, 265–274 [19] Schaffalitzky, F

Planar induction of convergence and extension of the neural plate by the organizer of Xenopus.

PubMed

Keller, R; Shih, J; Sater, A K; Moreno, C

1992-03-01

This paper demonstrates that convergence and extension within the neural plate of Xenopus laevis are regulated by planar inductive interactions with the adjacent Spemann organizer. The companion article (Keller et al.: Developmental Dynamics 193:199-217, 1992) showed that the prospective hindbrain and spinal cord occupy a very short and very wide area just above the Spemann organizer in the early gastrula and that these regions converge and extend greatly during gastrulation and neurulation, using a sequence of radial and mediolateral cell intercalations. In this article, we show that "planar" contact of these regions with the organizer at their vegetal edge until stage 11 is sufficient to induce convergence and extension, after which their convergence and extension become autonomous. Grafts of the organizer in planar contact with uninduced ectodermal tissues induce these ectodermal tissues to converge and extend by a planar inductive signal from the organizer. Labeling of the inducing or responding tissues confirms that only planar interactions occur. Neural convergence and extension are actually hindered in explants deliberately constructed so that vertical interactions occur. These results show unambiguously that the Spemann organizer induces the extraordinary and precocious convergence and extension movements of the Xenopus neural plate by planar interactions acting over short distances.

Compact planar microwave blocking filters

NASA Technical Reports Server (NTRS)

U-Yen, Kongpop (Inventor); Wollack, Edward J. (Inventor)

2012-01-01

A compact planar microwave blocking filter includes a dielectric substrate and a plurality of filter unit elements disposed on the substrate. The filter unit elements are interconnected in a symmetrical series cascade with filter unit elements being organized in the series based on physical size. In the filter, a first filter unit element of the plurality of filter unit elements includes a low impedance open-ended line configured to reduce the shunt capacitance of the filter.