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Find video protocols related to scientific articles indexed in Pubmed.
90Sr content in 90Y-labeled SIR-spheres and Zevalin.
Health Phys
PUBLISHED: 10-02-2014
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Three different 90Y internally administered radionuclide therapies are currently used in both standard-of-care and clinical trial procedures atMD Anderson Cancer Center. TheraSphere and SIR-Spheres therapies utilize 90Y-labeled microspheres, while Zevalin is an 90Y-labeled radioimmunotherapeutic agent. Several publications have indicated radionuclidic impurities resulting from 90Y production methods. The 90Y in SIR-Spheres and Zevalin are produced from a 90Sr/90Y generator, which leaves measurable quantities of 90Sr in the final product. TheraSphere 90Y is produced in a nuclear reactor which results in a large number of impurities, most notably 88Y and 91Y. Product information sheets reference these impurities with specific limits given. These limits represent a tiny fraction of the total product activity, and in the case of TheraSphere and SIR-Spheres gamma-emitting impurities, this has been verified in the literature. An analysis of 90Sr impurities in SIR-Spheres and Zevalin is presented in this paper. Impurity quantities were found to be within the vendors’ documented limits.
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Plasmon enhanced water splitting mediated by hybrid bimetallic Au-Ag core-shell nanostructures.
Nanoscale
PUBLISHED: 09-05-2014
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In this work, we employed wet chemically synthesized bimetallic Au-Ag core-shell nanostructures (Au-AgNSs) to enhance the photocurrent density of mesoporous TiO2 for water splitting and we compared the results with monometallic Au nanoparticles (AuNPs). While Au-AgNSs incorporated photoanodes give rise to 14× enhancement in incident photon to charge carrier efficiency, AuNPs embedded photoanodes result in 6× enhancement. By varying nanoparticle concentration in the photoanodes, we observed ?245× less Au-AgNSs are required relative to AuNPs to generate similar photocurrent enhancement for solar fuel conversion. Power-dependent measurements of Au-AgNSs and AuNPs showed a first order dependence to incident light intensity, relative to half-order dependence for TiO2 only photoanodes. This indicated that plasmonic nanostructures enhance charge carriers formed on the surface of the TiO2 which effectively participate in photochemical reactions. Our experiments and simulations suggest the enhanced near-field, far-field, and multipolar resonances of Au-AgNSs facilitating broadband absorption of solar radiation collectively gives rise to their superior performance in water splitting.
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Engineered porous silicon counter electrodes for high efficiency dye-sensitized solar cells.
ACS Appl Mater Interfaces
PUBLISHED: 06-12-2014
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In this work, we demonstrate for the first time, the use of porous silicon (P-Si) as counter electrodes in dye-sensitized solar cells (DSSCs) with efficiencies (5.38%) comparable to that achieved with platinum counter electrodes (5.80%). To activate the P-Si for triiodide reduction, few layer carbon passivation is utilized to enable electrochemical stability of the silicon surface. Our results suggest porous silicon as a promising sustainable and manufacturable alternative to rare metals for electrochemical solar cells, following appropriate surface modification.
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Nanoporous TiO2 nanoparticle assemblies with mesoscale morphologies: nano-cabbage versus sea-anemone.
Nanoscale
PUBLISHED: 04-23-2014
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We report the novel synthesis of nanoporous TiO2 nanoparticle ensembles with unique mesoscale morphologies. Constituent nanoparticles evolved into multifaceted assemblies, exhibiting excellent crystallinity and enhanced photocatalytic activity compared with commercial TiO2. Such materials could be exploited for applications, like organic pollutant degradation.
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Antileishmanial phytochemical phenolics: molecular docking to potential protein targets.
J. Mol. Graph. Model.
PUBLISHED: 01-08-2014
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A molecular docking analysis has been carried out to examine potential Leishmania protein targets of antiprotozoal plant-derived polyphenolic compounds. A total of 352 phenolic phytochemicals, including 10 aurones, six cannabinoids, 34 chalcones, 20 chromenes, 52 coumarins, 92 flavonoids, 41 isoflavonoids, 52 lignans, 25 quinones, eight stilbenoids, nine xanthones, and three miscellaneous phenolic compounds, were used in the virtual screening study using 24 Leishmania enzymes (52 different protein structures from the Protein Data Bank). Noteworthy protein targets were Leishmania dihydroorotate dehydrogenase, N-myristoyl transferase, phosphodiesterase B1, pteridine reductase, methionyl-tRNA synthetase, tyrosyl-tRNA synthetase, uridine diphosphate-glucose pyrophosphorylase, nicotinamidase, and glycerol-3-phosphate dehydrogenase. Based on in-silico analysis of antiparasitic polyphenolics in this study, two aurones, one chalcone, five coumarins, six flavonoids, one isoflavonoid, three lignans, and one stilbenoid, can be considered to be promising drug leads worthy of further investigation.
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Evaluation of a semiautomated lung mass calculation technique for internal dosimetry applications.
Med Phys
PUBLISHED: 12-11-2013
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Purpose: The authors sought to evaluate a simple, semiautomated lung mass estimation method using computed tomography (CT) scans obtained using a variety of acquisition techniques and reconstruction parameters for mass correction of medical internal radiation dose-based internal radionuclide radiation absorbed dose estimates.Methods: CT scans of 27 patients with lung cancer undergoing stereotactic body radiation therapy treatment planning with PET?CT were analyzed retrospectively. For each patient, free-breathing (FB) and respiratory-gated 4DCT scans were acquired. The 4DCT scans were sorted into ten respiratory phases, representing one complete respiratory cycle. An average CT reconstruction was derived from the ten-phase reconstructions. Mid expiration breath-hold CT scans were acquired in the same session for many patients. Deep inspiration breath-hold diagnostic CT scans of many of the patients were obtained from different scanning sessions at similar time points to evaluate the effect of contrast administration and maximum inspiration breath-hold. Lung mass estimates were obtained using all CT scan types, and intercomparisons made to assess lung mass variation according to scan type. Lung mass estimates using the FB CT scans from PET?CT examinations of another group of ten male and ten female patients who were 21-30 years old and did not have lung disease were calculated and compared with reference lung mass values. To evaluate the effect of varying CT acquisition and reconstruction parameters on lung mass estimation, an anthropomorphic chest phantom was scanned and reconstructed with different CT parameters. CT images of the lungs were segmented using the OsiriX MD software program with a seed point of about -850 HU and an interval of 1000. Lung volume, and mean lung, tissue, and air HUs were recorded for each scan. Lung mass was calculated by assuming each voxel was a linear combination of only air and tissue. The specific gravity of lung volume was calculated using the formula (lung HU - air HU)?(tissue HU - air HU), and mass = specific gravity × total volume × 1.04 g?cm(3).Results: The range of calculated lung masses was 0.51-1.29 kg. The average male and female lung masses during FB CT were 0.80 and 0.71 kg, respectively. The calculated lung mass varied across the respiratory cycle but changed to a lesser degree than did lung volume measurements (7.3% versus 15.4%). Lung masses calculated using deep inspiration breath-hold and average CT were significantly larger (p < 0.05) than were some masses calculated using respiratory-phase and FB CT. Increased voxel size and smooth reconstruction kernels led to high lung mass estimates owing to partial volume effects.Conclusions: Organ mass correction is an important component of patient-specific internal radionuclide dosimetry. Lung mass calculation necessitates scan-based density correction to account for volume changes owing to respiration. The range of lung masses in the authors patient population represents lung doses for the same absorbed energy differing from 25% below to 64% above the dose found using reference phantom organ masses. With proper management of acquisition parameters and selection of FB or midexpiration breath hold scans, lung mass estimates with about 10% population precision may be achieved.
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Surface engineered porous silicon for stable, high performance electrochemical supercapacitors.
Sci Rep
PUBLISHED: 07-24-2013
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Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10-40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage.
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Hybrid Modality Fusion of Planar Scintigrams and CT Topograms to Localize Sentinel Lymph Nodes in Breast Lymphoscintigraphy: Technical Description and Phantom Studies.
Int J Mol Imaging
PUBLISHED: 08-20-2010
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Lymphoscintigraphy is a nuclear medicine procedure that is used to detect sentinel lymph nodes (SLNs). This project sought to investigate fusion of planar scintigrams with CT topograms as a means of improving the anatomic reference for the SLN localization. Heretofore, the most common lymphoscintigraphy localization method has been backlighting with a (57)Co sheet source. Currently, the most precise method of localization through hybrid SPECT/CT increases the patient absorbed dose by a factor of 34 to 585 (depending on the specific CT technique factors) over the conventional (57)Co backlighting. The new approach described herein also uses a SPECT/CT scanner, which provides mechanically aligned planar scintigram and CT topogram data sets, but only increases the dose by a factor of two over that from (57)Co backlighting. Planar nuclear medicine image fusion with CT topograms has been proven feasible and offers a clinically suitable compromise between improved anatomic details and minimally increased radiation dose.
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Acquisition parameters for oncologic imaging with a new SPECT/multislice CT scanner.
Mol Imaging Biol
PUBLISHED: 01-05-2010
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Single photon emission computed tomography/computed tomography (SPECT/CT) delivers in a single imaging modality the functional-metabolic information from the SPECT image, combined with the detailed anatomical information from a diagnostic quality CT scanner.
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Effect of voxel size and computation method on Tc-99m MAA SPECT/CT-based dose estimation for Y-90 microsphere therapy.
IEEE Trans Med Imaging
PUBLISHED: 11-04-2009
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The use of selective internal radiation therapy for treatment of hepatocellular carcinoma and liver metastases using Y-90 labeled microspheres has become an effective and widely used treatment regimen. However, dosimetric evaluations of this treatment are still primitive as uniform distribution models based only on injected activity are often used. This investigation attempts to quantify the effectiveness of several sophisticated patient-specific techniques which utilize the source distribution of Tc-99m MAA simulation studies to perform voxelized dosimetric computations. Among these techniques are complete Monte-Carlo radiation transport computation in patient-specific CT-based voxel phantoms, local energy deposition in patient specific phantoms and kernel transport techniques in water. Each technique was evaluated using three different phantom voxel dimensions and SPECT reconstruction matrix sizes. Dose evaluation results using all methods were compared to the exact solution, obtained using fully 3-D Monte-Carlo simulations with source distribution based not on SPECT data, but on the injected activity and exact boundaries of the anthropomorphic phantom used in the study. The results of this study show that at large voxel sizes and using SPECT reconstructions with a small matrix size (64 x 64), Monte-Carlo and local deposition methods are nearly equivalent. However, using a large SPECT reconstruction matrix (256 x 256) the local deposition method is significantly more accurate than full 3-D Monte-Carlo transport, and with a negligible computational burden.
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A novel method to evaluate gamma camera rotational uniformity and sensitivity variation.
Med Phys
PUBLISHED: 07-21-2009
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An alternative to the conventional method of performing the AAPM Report 52 rotational uniformity and sensitivity test has been developed. In contrast to the conventional method in which a Co-57 sheet source is fastened to the collimator, this new point-source method acquires the images intrinsically using a Tc-99m point source placed near the isocenter of gantry rotation. As with the conventional method, the point-source method acquires 5 x 10(6) count flood images at four distinct gantry positions to calculate the maximum sensitivity variation (MSV)--a quantitative metric of rotational uniformity and sensitivity variation. The point-source method incorporates corrections for the decay of Tc-99m between acquisitions, the curvature in the image intensity due to variation in photon flux across the detector from a near-field source, and the source-to-detector distance variations between views. The raw point-source images were fitted with an analytic function in order to compute curvature- and distance-corrected images prior to analysis. Five independent MSV measurements were performed using both conventional and point-source methods on a single detector of a dual-headed SPECT system to estimate the precision of each method. The precision of the point-source method was further investigated by performing ten independent measurements of MSV on six different detectors. Correlation between the MSV calculated by the two methods was investigated by performing the test on nine different detectors using both methods. Different levels of sensitivity variations were also simulated on four detectors to generate 40 additional paired points for correlation analysis. The effect of the total image counts on the MSV estimated with the new method was evaluated by acquiring image sequences with 5 x 10(6), 10 x 10(6), and 20 x 10(6) count images. The MSV calculated using the conventional and point-source methods exhibited a high degree of correlation and consistency with equivalence. The precision of the point-source method (0.145%) is lower than the conventional method (0.04%) but sufficient to test MSV. No statistically significant dependence of MSV with the point-source method on the total image counts over a range of (5-20) x 10(6) counts was observed. Curvature correction of the images prior to the generation of difference images renders images more conducive to qualitative inspection for structured, nonrandom patterns. The advantages of the new methodology are that multiple detectors of a gamma camera can be evaluated simultaneously which substantially reduces the time required for MSV testing and the reduced risk of accidental damage to the collimators and patient proximity detection system from having to mount a sheet source on each of the detectors.
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Estimation of yttrium-90 Zevalin tumor-absorbed dose in ocular adnexal lymphoma using quantitative indium-111 Zevalin radionuclide imaging.
Nucl Med Commun
PUBLISHED: 06-17-2009
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The purpose of this investigation was to estimate radiation-absorbed dose in orbital tumors from yttrium-90 ibritumomab tiuxetan (Zevalin) radioimmunotherapy of ocular adnexal lymphoma.
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Radiation dosimetry and biodistribution of (99m)Tc-ethylene dicysteine-deoxyglucose in patients with non-small-cell lung cancer.
Eur. J. Nucl. Med. Mol. Imaging
PUBLISHED: 03-23-2009
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To assess the radiation dosimetry and biodistribution of (99m)Tc-labeled ethylene dicysteine deoxyglucose ((99m)Tc-EC-DG) in patients with non-small-cell lung cancer (NSCLC).
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Yttrium-90 ibritumomab tiuxetan doses calculated to deliver up to 15 Gy to critical organs may be safely combined with high-dose BEAM and autologous transplantation in relapsed or refractory B-cell non-Hodgkins lymphoma.
J. Clin. Oncol.
PUBLISHED: 03-02-2009
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To determine the maximum-tolerated radiation-absorbed dose (RAD) to critical organs delivered by yttrium-90 ((90)Y) ibritumomab tiuxetan in combination with high-dose carmustine, etoposide, cytarabine, and melphalan (BEAM) chemotherapy with autologous transplantation.
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Long-lived impurities of 90Y-labeled microspheres, TheraSphere and SIR-spheres, and the impact on patient dose and waste management.
Health Phys
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Yittrium-90 microsphere brachytherapy procedures have increased in number due to their efficacy in treating some unresectable metastatic liver tumors. The discovery of long-lived impurities in two microsphere products, first reported between 2006 and 2007, has resulted in some radiation safety concerns. Since then, microsphere production processes have been refined, which reportedly lead to a reduction in detectable by-products. In this study unused vials of TheraSphere and SIR-Spheres, manufactured in early January 2011, were analyzed to identify and quantify the low-level radioactive impurities. Absorbed dose calculations were performed to assess the potential increased dose to the patient due to long-lived impurities. Results showed that while the SIR-Spheres vials contained no detectable impurities (contrary to other published results in the literature), the TheraSphere vials contained 17 radionuclides in one sample and 15 in the other. The dominant impurities were Y and Y, with specific activities ranging from 0.99 ± 3.40 × 10 kBq mg to 6.30 ± 0.40 kBq mg at vendor assay date. Other impurities were on the order of Bq mg. Based on Medical Internal Radiation Dose (MIRD) liver and lung dose estimates, the long-lived impurities would be expected to increase an administered dose by less than 0.1% from the prescribed dose.
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Nonmyeloablative allogeneic transplantation with or without 90yttrium ibritumomab tiuxetan is potentially curative for relapsed follicular lymphoma: 12-year results.
Blood
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In 2008, we reported favorable 5-year outcomes of nonmyeloablative allogeneic stem cell transplantation after fludarabine, cyclophosphamide, rituximab (FCR) conditioning for relapsed and chemosensitive follicular lymphoma. However, innovative strategies were still needed to treat patients with chemorefractory disease. We therefore subsequently performed a trial in which (90)Y-ibritumomab tiuxetan (0.4 mCi/kg) was added to the fludarabine, cyclophosphamide conditioning regimen ((90)YFC). Here, we report updated results of the FCR trial and outcomes after (90)YFC. For the FCR group (N = 47), since the last update, one patient developed recurrent disease. With a median follow-up of 107 months (range, 72-142 months), the 11-year overall survival and progression-free survival rates were 78%, and 72%, respectively. For the (90)YFC group (N = 26), more patients had chemorefractory disease than did those in the FCR group (38% and 0%, P < .001). With a median follow-up of 33 months (range,17-94 months), the 3-year progression-free survival rates for patients with chemorefractory and chemosensitive disease were 80% and 87%, respectively (P = .7). The low frequency of relapse observed after a long follow-up interval of 9 years in the FCR group suggests that these patients are cured of their disease. The addition of (90)Y to the conditioning regimen appears to be effective in patients with chemorefractory disease. This trial was registered at www.clinicaltrials.gov as NCT00048737.
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A preclinical investigation of the saturation and dosimetry of 153Sm-DOTMP as a bone-seeking radiopharmaceutical.
Nucl. Med. Biol.
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The therapeutic potential of the bone-seeking radiopharmaceutical 153Sm-labeled 1,4,7,10-tetraazacyclododecanetetramethylenephosphonic acid (153Sm-DOTMP) was assessed by measuring its dosage-dependent skeletal uptake at two chelant-to-metal ratios and its source organ residence times at a chelant-to-metal ratio of 1.5:1. A similar agent, 153Sm-labeled ethylenediaminetetramethylenephosphonic acid (153Sm-EDTMP), has been reported to exhibit dosage-limiting skeletal saturation.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.