Amount Of Tracers Research Articles

Количественная лимфосцинтиграфия с Tc-99m-технефитом у больных с постмастэктомической лимфедемой верхней конечности

The paper presents results of research on the potential of quantitative radionuclide lymphoscintigraphy (LS) with radioactive tracer (Tc-99m-technephyte) for evaluation of the upper limb lymphedema, developed in different time periods after mastectomy and axillary lymph nodes dissection in 56 breast cancer patients (females). Before LS-imaging the tracer was subcutaneously injected in the affected and normal extremities. The Tc-99m-technephyte clearance rate from the injection site on the affected hand was higher than the tracer clearance rate from the site of injection on the normal hand, the difference in the rates was statistically insignificant. This difference did not depend on the lymphoma stage (the difference between clearance rates was 4-9%, difference in the amount of tracers cleared was 6-8%). It means that informative value of Tc-99m-technephyte clearance is very low and cannot be used for differential diagnostics of lymphedema stage. To obtain more important information the quantitative asymmetry index (QAI) was used. It was shown that in all parts of the upper limb lymphedema (forearm, shoulder, and arm in general) there was a significant difference between QAI indices for lymphedema stages I, II and III. However, the significant variability of the QAI indices makes difficult proper interpretation of LS provided images. The obtained data show that the clinical and functional staging of the lymphedema is not identical, and also confirm the possibility of the presence of areas in the edematous extremity at different stages of lymph drainage disorder. The data also support the hypothesis that lymph drainage in the edematous extremity parts may be impaired in areas with different lymph drainage stages. Quantifying LS with QAI can be useful when choosing a treatment method, evaluating its effectiveness, and dynamic monitoring.

Subsurface monitoring and surveillance using inter-well gas tracers

Abstract Tracer technology has gained considerable attention recently as an effective tool in the reservoir monitoring and surveillance toolkit, particularly in improved oil recovery (IOR) operations. Gas flow paths within the reservoir can be quite different from liquid (oil and water) flow paths. This is primarily due to gravity override, and differences in density and relative permeability between the gas and liquid phases. An Inter Well Gas Tracer Test (IWGTT) is a key monitoring and surveillance tool for any IOR projects. IWGTT should be designed and implemented to track the flow behavior of gas phase. The test generally entails injecting a small amount of unique perflouro-hydrocarbon tracers into the gas phase injectant stream. IWGTT have been conducted on a limited number of fields across the globe, and sample results of some will be presented. The sampling frequency of the tracers from the producers should be designed carefully to collect the necessary data that will provide insights about the connectivity between the injectors and producers well pairs, gas breakthrough times (“time of flight”), and possible interwell fluid saturations. Different fit-for-purpose unique tracers can be deployed in the subject injector(s) stream and their elution can be monitored in the corresponding up-dip producer(s). In addition to reservoir connectivity and breakthrough times between injector and producer pairs, an IWGTT helps in optimizing water altering gas (WAG) operations and production strategies for gas injection projects, improve sweep efficiency and ultimately enhance oil recovery. It can also be used to identify source of inadvertent gas leakage into shallow aquifers or soil gas, and help in the planning and placement of future wells. This paper reviews the workflow and necessary logistics for the successful deployment of an interwell gas tracer test. It will provide the best practices for designing, sampling, analyzing and interpreting a gas tracer deployment. The paper also highlights the benefits of gas tracer data and their usefulness in understanding well interconnectivity and dynamic fluid flow in the reservoir. The results can be used to refine the reservoir simulation model and fine-tune its parameters. This effort should lead to better reservoir description and an improved dynamic simulation model. The challenges associated with IWGTT will also be shared.

Wine markers in archeological potteries: detection by GC-MS at ultratrace levels.

The detection of organic residues that remain absorbed into the pores of ceramic artifacts constitutes a source of information regarding their management. Taking into account the poor conservation state of the potteries and the low amount of the organic tracers together with the main drawbacks to get the relevant information concerning different aspects of past societies, the detection of organic biomarkers is still an analytical challenge. In this work, an improved analytical methodology to maximize the recovery of organic markers related to wine in archeological ceramics is presented. The developed method consists on the extraction of wine-related organic compounds including tartaric acid, malic acid, fumaric acid, succinic acid, citric acid, and syringic acid by means of ultrasonic probe-assisted extraction (UPAE) followed by a preconcentration step by mixed-mode strong anion exchange and reversed-phase solid-phase extraction (SPE) and a derivatization step prior to analysis by means of gas chromatography-mass spectrometry (GC-MS). Finally, the method was applied to real archeological ceramic fragments (two dolia), suspected to have been used to store wine, together with organic residues found inside two amphorae from Zaragoza (Spain). Graphical abstract.

Roles of the Ocean Mesoscale in the Horizontal Supply of Mass, Heat, Carbon, and Nutrients to the Northern Hemisphere Subtropical Gyres

AbstractHorizontal transport at the boundaries of the subtropical gyres plays a crucial role in providing the nutrients that fuel gyre primary productivity, the heat that helps restratify the surface mixed layer, and the dissolved inorganic carbon that influences air‐sea carbon exchange. Mesoscale eddies may be an important component of these horizontal transports; however, previous studies have not quantified the horizontal tracer transport due to eddies across the subtropical gyre boundaries. Here we assess the physical mechanisms that control the horizontal transport of mass, heat, nutrients, and carbon across the North Pacific and North Atlantic subtropical gyre boundaries using the eddy‐rich ocean component of a climate model (Geophysical Fluid Dynamics Laboratory Climate Model version 2.6) coupled to a simple biogeochemical model (mini‐BLING). Our results suggest that horizontal transport across the gyre boundaries supplies a substantial amount of mass and tracers to the ventilated layer of both Northern Hemisphere subtropical gyres, with the Kuroshio and Gulf Stream acting as main exchange gateways. Mass, heat, and dissolved inorganic carbon supply is principally driven by the time‐mean circulation, whereas nutrient transport differs markedly from the other tracers, as nutrients are mainly supplied to both subtropical gyres by downgradient eddy mixing across gyre boundaries. A budget analysis further reveals that the horizontal nutrient transport, combining the roles of both mean and eddy components, is responsible for more than three quarters of the total nutrient supply into the subtropical gyres, surpassing a recent estimate based on a coarse‐resolution model and thus further highlighting the importance of horizontal nutrient transport.

Optical Microrheology of Protein Solutions Using Tailored Nanoparticles.

This work represents a critical re-examination of the application of dynamic light scattering (DLS)-based tracer particle microrheology to measure the zero shear viscosity of aqueous solutions of different proteins up to very high concentrations. It is demonstrated that a combination of surface-functionalized tracer particles, the use of the so-called 3D-DLS technique, and carefully chosen parameters for the scattering experiments is essential for a reliable and artifact-free determination of the viscosity of highly diverse protein solutions, while keeping the amount of protein to a minimum. The major challenges that arise in such microrheology experiments with protein solutions are discussed and used as guiding principles for the synthesis of all-purpose tracer particles with optimal size and an efficient surface functionalization, and the choice of the appropriate amount of tracers in the sample. Potential problems arising from depletion attractions between the tracer particles induced by the proteins are addressed, and compelling evidences for the absence of such effects are presented. The validity of the approach is corroborated by the perfect agreement between the zero shear viscosity obtained from 3D-DLS-based microrheology and literature data from classical rheological measurements for two vastly different protein-solvent systems up to concentrations close to the arrest transition.

Stable isotopes as tracers can reveal resource allocation in juvenile golden gray mullets (Liza aurata, Risso, 1810)

Studies on the nutritional physiology of predator fish in the marine environment have contributed to our understanding of how they adapt to the environment and how they have evolved. Despite the fact that herbivorous and omnivorous fish species are numerous and play a significant role in the ecosystem, there is little information on how they process nutrients and how these are allocated to different tissues. This information could be particularly important for the juvenile stages, when small-sized fish are under high predation pressure and have a limited capability to intake and digest large quantities of food. The mullet Liza aurata ingests surface sediment and obtains its nutritional requirements from the organisms associated with the sediment, including microalgae and bacteria or small invertebrates. This paper examines how the carbon and nitrogen derived from benthic micro-organisms are allocated to the liver and muscle tissues of newborn (young-of-the-year, YOY) and one-year-old (OYO) individuals. After the animals were left feeding on 13C-enriched microalgae and 15N-enriched bacteria for 1 h, we traced the 13C and 15N in the liver and muscle tissues as well as in the blood and the gut. The YOY allocated 99% of the 13C and 88% of the 15N to the muscles, while the liver had a negligible amount of tracers (0.4% and 11% for 13C and 15N). Conversely, in the OYO experiment, the tracers were uniformly distributed throughout the muscle and liver (57% of 13C and 45% of 15N were found in the muscle, whereas 43% of 13C and 55% of 15N were in the liver). Negligible amounts were traced in the blood (<0.1%), while a part of the tracers was not assimilated and remained in the gut of both YOY and OYO fish. These results indicated a size-related shift in resource allocation during first year of growth of L. aurata, probably related to changes in the survival strategies among juveniles. Our results also indicated that stable isotope enrichment can be a helpful tool for studying resource allocation in fish.

Brown adipose tissue and lipid metabolism imaging.

Brown adipose tissue (BAT) research has evolved from an underestimated to a fast developing field. Its assumed curing properties for the world wide epidemic obesity, and its related diseases, makes this tissue an interesting target for a broad amount of non-invasive molecular BAT tracers. Apart from 18F-FDG PET/CT there are several methods to detect BAT and measure its metabolism in a more appropriate way. Especially interesting is the measure of lipid turnover, because fatty acids comprise the main fuel for active BAT. This review outlines different imaging modalities suitable for BAT imaging with the overall goal to explain the yet not completely understood mechanism in BAT and its quantitative contribution to whole body lipid and energy metabolism. Publications with focus on brown adipose tissue and lipid metabolism imaging are analyzed, different imaging approaches are introduced and promising BAT tracers are presented. Radiolabelled and fluorescent fatty acids, labelled particles, 3H-Triolein and ADIFAB staining can give information about the inflow and therefore about the utilization of fatty acids which represents the activation state in vivo/in vitro. Non-invasive scanning with CT or MRI is a useful addition to those techniques. Lipid metabolism imaging offers the opportunity to visualize and quantify yet undiscovered aspects of BAT metabolic activities and is key to completely clarify its role in whole body lipid and energy metabolism.

Experimental Validation of Extended Stratification Model: Part A—Ore with Tracer Particle Studies in a Batch Jig Operation

Particle stratification in gravity concentrators is influenced by both particle size and particle density. King’s stratification model defines very well the segregation of particles in bed forming separators but is based on mono-sized feed particles that are distributed in density. The model has been extended to incorporate particle size effects into it and to define segregation patterns of the bed (Venkoba Rao in Int J Miner Process 85:50, 2007). The extended stratification model shows that the segregation patterns evaluated from it at various cut heights conform to size-density partition surfaces. The model is more theoretical when proposed and lack experimental evidence. In Part A of this series of papers, the model is validated with segregation patterns measured from a batch jig operation by introducing small amount of tracer particles (of various sizes and densities) along with feed particles of fluorite ore. Such patterns formed by tracers are measured by slicing the segregated bed at various cut heights. The patterns of partition surfaces by tracers are in support of the extended stratification model. This exercise also shows that small amount of size-density tracers along with feed particles can quickly help to characterize the segregation patterns of a jig bed. Also, by inferring segregation patterns from Part B of this paper series, a single go approach is proposed to correct the errors of partition surfaces of the entire bed, arising from sparse measured tracer data at various bed heights.

Metal carbonyl tracers and the ferrocifen family: Two facets of bioorganometallic chemistry

Our contribution to the domain of bioorganometallic chemistry is mainly focused on two different topics, namely the use of metal carbonyl complexes for infrared quantification of minute amount of tracers and the development of new organometallic drugs. In this review associated with the awarding of the 2012 Elsevier prize for outstanding contribution to bioorganometallic chemistry, I will focus on these two aspects that we helped to develop with the emphasis on our most recent works. Regarding the first topic we have recently synthesized antibodies multilabelled with metal carbonyl tracers. They open the way for the development of a full solid phase Carbonyl Metallo Immuno Assay (CMIA) based on their quantification by infrared. We have also demonstrated the feasibility of the cellular imaging of a Re(CO)3 complex in a single cell, by AFM-IR spectromicroscopy, a cutting edge technique using a set-up coupling atomic force microscopy and a tunable pulsed infrared laser. Precise localization of the rhenium complex in the cell nucleus is obtained by using detection of the characteristic ν(CO) bands of the complex. Concerning the second topic, we have prepared a large series of molecules possessing a ferrocenyl-diphenyl-butadiene skeleton, and recently their corresponding [3] ferrocenophane complexes leading to the selection of three hits (Fc-OH-Tam, Fc-diOH and DP1). These three complexes show a significant antiproliferative effect on cancer cells. However they seem to act via different mechanisms. In vivo experiments performed with Fc-diOH on rat with implanted tumors (9L cells from glioma) have shown that its formulation in lipid nanocapsules led to almost total disappearance of implanted tumors.

In situ abrasion of marked pebbles on two coarse-clastic beaches (Marina di Pisa, Italy)

In this paper pebbles marked by passive integrated transpon ders from two artificial coarse-grained beaches at Marina di Pisa (Tuscany, Italy) were analyzed in order to measure the in situ abra sion rate. The beaches (Cella 7 and Barbarossa) were set up in 2006 as a form of coastal protection. They are both composed of pebbles (30-to-90 mm diameter) and bounded longshore by huge groynes. They differ in length (250 m and 110 m respectively) and in the prese nce of an additional defense structure, a submerged breakwater 50 m off the coastline, at Cella 7. The aim of the study is to reckon the abrasion rate of individual pebbles and evaluate abrasion differen ces of pebbles released on Cella 7 and on Barbarossa. The RFID technology (Radio Frequency Identification) was used to track the pebbles due to its reliability and limited costs. The tracers were released on the beaches in March 2009 along closely-spaced crossshore transects. The recovery campaign was carried out in May 2009. A total of 127 pebbles was detected, 83 of which were recov ered. Huge beach reworking during the storms determined high burial rates and consequently the loss of a definite amount of tracers. The pebbles that were recovered showed a significant increase in roundness, in particular the tracers that were released on Bar barossa. The average pebble weight loss measured at Cella 7 was slightly lower, which means lower mobilization rate at this site rather than at Barbarossa. The resulting values are significant considering the short time frame of the research (two months) and the limited energy of the storms occurred during the experiment.

The influence of mass of [11C]-laniquidar and [11C]-N-desmethyl-loperamide on P-glycoprotein blockage at the blood–brain barrier

An earlier report suggested that mass amount of PET tracers could be an important factor in brain uptake mediated by P-glycoprotein. Thereby, this study investigated the influence of mass dose of laniquidar, desmethyl-loperamide and loperamide on the P-glycoprotein-mediated brain uptake of, respectively, [(11)C]-laniquidar and [(11)C]-N-desmethyl-loperamide ([(11)C]-dLop). Wild-type (WT) mice were injected intravenously with solutions of 5.6 MBq [(11)C]-laniquidar (either no carrier added or 60 mg/kg laniquidar added) or with 5.0-7.4 MBq [(11)C]-dLop (either no carrier added or 3 mg/kg desmethyl loperamide). Mice were killed, and brain and blood were collected, weighted and counted for radioactivity. Mdr1a(-/-) knockout mice were incorporated as the control group. Injection of (11)C-laniquidar (no carrier added) in WT mice resulted in a statistical significant lower brain uptake (0.7±0.2 %ID/g) compared to the carrier-added formulation (60 mg/kg laniquidar) (3.1±0.3 %ID/g) (P=.004), while no statistical difference could be observed between formulations of [(11)C]-dLop. The [(11)C]-laniquidar and [(11)C]-dLop blood concentrations were not significantly different between the tested formulations in WT mice. In control animals, no effect of mass amount on brain uptake of both tracers could be demonstrated. These results demonstrate the bivalent character of laniquidar, acting as a substrate at low doses and as a blocking agent for P-glycoprotein transport in the brain at higher doses. In comparison, no difference was observed in [(11)C]-dLop uptake between carrier- and no-carrier-added formulations, which confirms that desmethyl-loperamide is a substrate of P-glycoprotein at the blood-brain barrier.

Spatial distributions of 137Cs and 239+240Pu in surface seawater within the Exclusive Economic Zone of East Coast Peninsular Malaysia

The studies of (137)Cs and (239+240)Pu distributions in surface seawater at South China Sea within the Exclusive Economic Zone (EEZ) of Peninsular Malaysia were carried out in June 2008. The analysis results will serve as additional information to the expanded baseline data for Malaysia's marine environment. Thirty locations from extended study area were identified in the EEZ from which large volumes of surface seawater samples were collected. Different co-precipitation techniques were employed to concentrate cesium and plutonium separately. A known amount of (134)Cs and (242)Pu tracers were used as yield determinant. The precipitate slurry was collected and oven dried at 60(o)C for 1-2 days. Cesium precipitate was fine-ground and counted using gamma-ray spectrometry system at 661.62keV, while plutonium was separated from other radionuclides using anion exchange, electrodeposited and counted using alpha spectrometry. The activity concentrations of (137)Cs and (239+240)Pu were in the range of 3.40-5.89Bq/m(3) and 2.3-7.9mBq/m(3), respectively. The (239+240)Pu/(137)Cs ratios indicate that there are no new inputs of these radionuclides into the area.

Quantification of pumping rate of Chironomus plumosus larvae in natural burrows

This paper investigates and compares experimentally determined water velocity field above natural macrozoobenthos burrows generated by Chironomus Plumosus larva during their bio-irrigation activity. All experiments were carried out using particle image velocimetry and performed in mesocosms filled with sediment burrowed by larvae, and the water velocity fields near the inlets and outlets of the U-shaped burrows were measured. From water velocity data the average volumetric flow rates between 54.6 and 61.1 mm3/s were calculated. Assuming an average burrow diameter of 2.25 mm, the volumetric flow rates suggest the average flow velocities through burrows during the pumping period between 13.7 and 15.4 mm/s. Two additional interesting phenomena could also be shown by analyzing the flow field generated by the larva. The analysis of the amount of tracers used for visualizations revealed that some of the tracer particles added to the water must have been consumed along their path from the inlet toward the outlet, hinting clearly to the so-called filter-feeding action of C. plumosus. The second phenomenon is due to the form of motion C. plumosus generates. By careful flow visualizations it was found that unlike other organisms such as Urechis caupo that use peristaltic body contractions, C. plumosus worms its body sinusoidally catapulting the fluid far into the overlying water body. This action is of ecological advantage for it avoids generating short oxygen circuits for their respiration and filter feeding.

Temperature effects on solute transport: In vivo imaging of the growth plate

Determining how the environment modulates bone elongation is central to understanding skeletal variation. Ambient temperature and physical activity can alter limb length, but the mechanisms by which they do so remain elusive. Solute delivery to cartilaginous growth plates could play a key role since nutrient supply is critical to bone elongation. Advances in imaging technology have revolutionized our ability to visualize growth plates in vivo, but quantitative methods are still lacking. We developed standards for measuring solute delivery ‐‐defined by amount and entry rate of intravenous tracers‐‐ in tibial growth plates of 5 week old mice using multiphoton microscopy. Following IACUC protocols, we employed an acute temperature model (N=6/group) to test the hypothesis that solute delivery is increased or decreased by warm (36C) or cool (23C) limb temperature, holding other physiological parameters constant. Solute delivery differed as predicted with significantly more tracer in growth plates at 36C. These data validate the sensitivity of the method, which we are now using to assess chronic temperature and exercise effects on limb length and nutrient supply to the growth plate. These results are relevant to strategies for delivering therapeutic agents to growth plates of children and have the potential to greatly advance our understanding of skeletal variability in mammals. Supported by NIH‐RO1AR052003‐04.Grant Funding SourceNIH‐RO1AR052003‐04

C105 ニューラルネットを用いた勾配法に基づくPIV

Conventional PIVs are not always capable of measuring the entire field of two-dimensional flow in rivers and oceans as they often contain an insufficient amount of tracers. However, Gradient-Based PIV using Neural Networks is potentially able to perform these field measurements. In a previous study, we evaluated its usefulness using artificially generated images. Here we apply this method to surface velocity measurements of experimental open channel flow. The open channel was filled with water and its flow was 100mm wide and 40mm depth. The flow rate was kept at a constant value of 60cm3/s. Floating tracers were used to measure the surface velocity. Several images were taken with the tracer population ranging from 18% to 81% of the water surface. The obtained velocity data were compared with those produced by conventional PIVs. As a result, it was found that Gradient-Based PIV using Neural Networks is capable of observing two-dimensional flow even when the tracer population is 18% of the water surface.

DEPOSITION ANALYSIS OF SEVERAL APPLICATION VOLUMES OF PESTICIDES ADAPTED TO THE GROWTH OF A GREENHOUSE TOMATO CROP

For the calculation of the pesticide-application volume in a greenhouse tomato crop, four spray tests have been made in different states of crop growth. For this, the spray tests were conducted sequentially with three application volumes for each growth stage. The tracers used were tartrazine, indigo carmine, and patent blue. For the characterization of crop canopy, the evolution of its growth were studied, measuring LAI (Leaf Area Index), which ranged from 0.68 and 3.16 m·m, and the geometric parameters that define the volume of the vegetation, in order to calculate the TRV (Tree Row Volume) and UCR (Unit Canopy Row). The tests were made with a vertical boom sprayer equipped with a variable number of flat fan nozzles, depending on the height of the crop. LAI was used to calculate the theoretical application volume applying the method of the optimal coverage, spraying the theoretically optimal amount, in addition to 33 % more and 33% less. The deposition was measured at three heights and four depths in the canopy, with four replications per treatment. From the results, the standardized depositions were calculated, based on the amount of tracers per surface ground unit, in addition to identifying the most suitable application volume, based on the standardized deposition and the degree of its uniformity in the canopy. The TRV values calculated were related to those of the application volume that better standardized deposition offered obtaining a regression model with a R of 0.9.

A211 ニューラルネットを用いた勾配法に基づくPIV

Conventional PIVs are not always capable of measuring the entire field of two-dimensional flow in rivers and oceans as they often contain an insufficient amount of tracers. However, Gradient-Based PIV using Neural Networks is potentially able to perform these field measurements. In a previous study, we evaluated its usefulness using artificially generated images. Here we apply this method to surface velocity measurements of experimental open channel flow. The open channel was filled with water and its flow was 100mm wide and 40mm depth. The flow rate was kept at a constant value of 60cm3/s. Floating tracers were used to measure the surface velocity. Several images were taken with the tracer population ranging from 18% to 81% of the water surface. The obtained velocity data were compared with those produced by conventional PIVs. As a result, it was found that Gradient-Based PIV using Neural Networks is capable of observing two-dimensional flow even when the tracer population is 18% of the water surface.

Oscillating time correlation functions from dynamic light scattering of gold-labeled tracers

Nanoparticles containing small gold clusters as labels have been used to study tracer diffusion in concentrated colloidal dispersions by dynamic light scattering. Our samples consisted of a small amount of gold tracers in a concentrated dispersion of nonlabeled matrix particles of similar size. Unexpectedly, the intensity time correlation functions showed oscillations. The unusual signal has been attributed to convection which may be caused by light absorption of the tracer particles, creating a thermal gradient within the sample. However, the origin of the oscillations in our homodyne light scattering experiment is still not perfectly understood. Here, we present a qualitative discussion concerning the dependency of oscillations both on laser light power and the concentration of matrix particles.

The simulation of the transport of aircraft emissions by a three-dimensional global model

Abstract. A three-dimensional off-line tracer transport model coupled to the ECMWF analyses has been used to study the transport of trace gases in the atmosphere. The model gives a reasonable description of their general transport in the atmosphere. The simulation of the transport of aircraft emissions (as NOx) has been studied as well as the transport of passive tracers injected at different altitudes in the North Atlantic flight corridor. A large zonal variation in the NOx concentrations as well as large seasonal and yearly variations was found. The altitude of the flight corridor influences the amount of tracers transported into the troposphere and stratosphere to a great extent.

The simulation of the transport of aircraft emissions by a three-dimensional global model

A three-dimensional off-line tracer transport model coupled to the ECMWF analyses has been used to study the transport of trace gases in the atmosphere. The model gives a reasonable description of their general transport in the atmosphere. The simulation of the transport of aircraft emissions (as NOx) has been studied as well as the transport of passive tracers injected at different altitudes in the North Atlantic flight corridor. A large zonal variation in the NOx concentrations as well as large seasonal and yearly variations was found. The altitude of the flight corridor influences the amount of tracers transported into the troposphere and stratosphere to a great extent.