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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,081 records · Page 60
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Fate of pathogens in a simulated bioreduction system for livestock carcasses

Highlights: Black-Right-Pointing-Pointer Bioreduction is a novel on-farm storage option for livestock carcasses. Black-Right-Pointing-Pointer Legislation demands that pathogens are contained and do not proliferate during carcass storage. Black-Right-Pointing-Pointer We examined the survival of key pathogens in lab-scale bioreduction vessels. Black-Right-Pointing-Pointer Pathogen numbers reduced in the resulting liquor waste and bioaerosols. Black-Right-Pointing-Pointer The results indicate that bioreduction should be validated for industry use. - Abstract: The EU Animal By-Products Regulations generated the need for novel methods of storage and disposal of dead livestock. Bioreduction prior to rendering or incineration has been proposed as a practical and potentially cost-effective method; however, its biosecurity characteristics need to be elucidated. To address this, Salmonella enterica (serovars Senftenberg and Poona), Enterococcus faecalis, Campylobacter jejuni, Campylobacter coli and a lux-marked strain of Escherichia coli O157 were inoculated into laboratory-scale bioreduction vessels containing sheep carcass constituents. Numbers of all pathogens and the metabolic activity of E. coli O157 decreased significantly within the liquor waste over time, and only E. faecalis remained detectable after 3 months. Only very low numbers of Salmonella spp. and E. faecalis were detected in bioaerosols, and only at initial stages of the trial. These results further indicate that bioreduction represents a suitable method of storing and reducing the volume of livestock carcasses prior to ultimate disposal.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2012

Methane and carbon dioxide production from simulated anaerobic degradation of cattle carcasses

Highlights: Black-Right-Pointing-Pointer This study evaluates methane and carbon dioxide production after land burial of cattle carcasses. Black-Right-Pointing-Pointer Disposal of animal mortalities is often overlooked in evaluating the environmental impacts of animal production. Black-Right-Pointing-Pointer we quantify annual emissions from cattle carcass disposal in the United States as 1.6 Tg CO{sub 2} equivalents. - Abstract: Approximately 2.2 million cattle carcasses require disposal annually in the United States. Land burial is a convenient disposal method that has been widely used in animal production for disposal of both daily mortalities as well as during catastrophic mortality events. To date, greenhouse gas production after mortality burial has not been quantified, and this study represents the first attempt to quantify greenhouse gas emissions from land burial of animal carcasses. In this study, anaerobic decomposition of both homogenized and unhomogenized cattle carcass material was investigated using bench-scale reactors. Maximum yields of methane and carbon dioxide were 0.33 and 0.09 m{sup 3}/kg dry material, respectively, a higher methane yield than that previously reported for municipal solid waste. Variability in methane production rates were observed over time and between reactors. Based on our laboratory data, annual methane emissions from burial of cattle mortalities in the United States could total 1.6 Tg CO{sub 2} equivalents. Although this represents less than 1% of total emissions produced by the agricultural sector in 2009, greenhouse gas emissions from animal carcass burial may be significant if disposal of swine and poultry carcasses is also considered.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2010

Animals In Synchrotrons: Overcoming Challenges For High-Resolution, Live, Small-Animal Imaging

Physiological studies in small animals can be complicated, but the complexity is increased dramatically when performing live-animal synchrotron X-ray imaging studies. Our group has extensive experience in high-resolution live-animal imaging at the Japanese SPring-8 synchrotron, primarily examining airways in two-dimensions. These experiments normally image an area of 1.8 mmx1.2 mm at a pixel resolution of 0.45 {mu}m and are performed with live, intact, anaesthetized mice.There are unique challenges in this experimental setting. Importantly, experiments must be performed in an isolated imaging hutch not specifically designed for small-animal imaging. This requires equipment adapted to remotely monitor animals, maintain their anesthesia, and deliver test substances while collecting images. The horizontal synchrotron X-ray beam has a fixed location and orientation that limits experimental flexibility. The extremely high resolution makes locating anatomical regions-of-interest slow and can result in a high radiation dose, and at this level of magnification small animal movements produce motion-artifacts that can render acquired images unusable. Here we describe our experimental techniques and how we have overcome several challenges involved in performing live mouse synchrotron imaging.Experiments have tested different mouse strains, with hairless strains minimizing overlying skin and hair artifacts. Different anesthetics have also be trialed due to the limited choices available at SPring-8. Tracheal-intubation methods have been refined and controlled-ventilation is now possible using a specialized small-animal ventilator. With appropriate animal restraint and respiratory-gating, motion-artifacts have been minimized. The animal orientation (supine vs. head-high) also appears to affect animal physiology, and can alter image quality. Our techniques and image quality at SPring-8 have dramatically improved and in the near future we plan to translate this experience to the Imaging and Medical Beamline at the Australian Synchrotron.Overcoming these challenges has permitted increasingly sophisticated imaging of animals with synchrotron X-rays, and we expect a bright future for these techniques.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Progress in Cell Marking for Synchrotron X-ray Computed Tomography

Recently there has been an increase in research activity into finding ways of marking cells in live animals for pre-clinical trials. Development of certain drugs and other therapies crucially depend on tracking particular cells or cell types in living systems. Therefore cell marking techniques are required which will enable longitudinal studies, where individuals can be examined several times over the course of a therapy or study. The benefits of being able to study both disease and therapy progression in individuals, rather than cohorts are clear. The need for high contrast 3-D imaging, without harming or altering the biological system requires a non-invasive yet penetrating imaging technique. The technique will also have to provide an appropriate spatial and contrast resolution. X-ray computed tomography offers rapid acquisition of 3-D images and is set to become one of the principal imaging techniques in this area. Work by our group over the last few years has shown that marking cells with gold nano-particles (GNP) is an effective means of visualising marked cells in-vivo using x-ray CT. Here we report the latest results from these studies. Synchrotron X-ray CT images of brain lesions in rats taken using the SYRMEP facility at the Elettra synchrotron in 2009 have been compared with histological examination of the tissues. Some deductions are drawn about the visibility of the gold loaded cells in both light microscopy and x-ray imaging.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2010

High Resolution X-Ray Microangiography of 4T1 Tumor in Mouse Using Synchrotron Radiation

Angiogenesis is very important in tumor growth and metastasis. But in clinic, only vessels lager than 200 {mu}m in diameter, can be observed using conventional medical imaging. Synchrotron radiation (SR) phase contrast imaging, whose spatial resolution can reach as high as 1 {mu}m, has great advantages in imaging soft tissue structures, such as blood vessels and tumor tissues. In this paper, the morphology of newly formed micro-vessels in the mouse 4T1 tumor samples was firstly studied with contrast agent. Then, the angiogenesis in nude mice tumor window model was observed without contrast agent using the SR phase contrast imaging at the beamline for X-ray imaging and biomedical applications, Shanghai Synchrotron Radiation Facility (SSRF). The images of tumors showed dense, irregular and tortuous tumor micro-vessels with the smallest size of 20-30 {mu}m in diameter.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Microangiography in Living Mice Using Synchrotron Radiation

Traditionally, there are no methods available to detect the fine morphologic changes of cerebrovasculature in small living animals such as rats and mice. Newly developed synchrotron radiation microangiography can achieve a fine resolution of several micrometers and had provided us with a powerful tool to study the cerebral vasculature in small animals. The purpose of this study is to identify the morphology of cerebrovasculature especially the structure of Lenticulostriate arteries (LSAs) in living mice using the synchrotron radiation source at Shanghai Synchrotron Radiation Facility (SSRF) in Shanghai, China. Adult CD-1 mice weighing 35-40 grams were anesthetized. Nonionic iodine (Omnipaque, 350 mg I /mL) was used as a contrast agent. The study was performed at the BL13W1 beam line at SSRF. The beam line was derived from a storage ring of electrons with an accelerated energy of 3.5 GeV and an average beam current of 200 mA. X-ray energy of 33.3 keV was used to produce the highest contrast image. Images were acquired every 172 ms by a x-ray camera (Photonic-Science VHR 1.38) with a resolution of 13 {mu}m/pixel. The optimal dose of contrast agent is 100 {mu}l per injection and the injecting rate is 33 {mu}l/sec. The best position for imaging is to have the mouse lay on its right or left side, with ventral side facing the X-ray source. We observed the lenticulostriate artery for the first time in living mice. Our result show that there are 4 to 5 lenticulostriate branches originating from the root of middle cerebral artery in each hemisphere. LSAs have an average diameter of 43{+-}6.8 {mu}m. There were no differences between LSAs from the left and right hemisphere (p<0.05). These results suggest that synchrotron radiation may provide a unique tool for experimental stroke research.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Blood Levels of Zinc in Creole Horses Used in Sera Production

Using Neutron Activation Analysis Zn concentrations were determined in blood of horses (Creole breed). No significant difference was observed between male (0.0029{+-}.0007 gL{sup -1}) and female (0.0031{+-}.0011 gL{sup -1}) animals. These data are an important support to understand the physiological functions of Zn in blood during the process of sera production at Butantan Institute (Sao Paulo, Brazil) using horses.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2010

Sodium Analysis in Whole Blood of Athletes Using NAA

In this investigation the sodium levels in blood were analyzed in athletes submitted to constant load exercise at treadmill (LABEX and UNICAMP) by NAA. These data were compared with the rest condition (before starting the exercise program) as well as with the sodium levels of the healthy group (control group) select from Blood Banks. The results showed alterations in sodium levels of the athletes during the exercise training, mainly increase, suggesting the necessity of its evaluation during physical activities.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2010

Environmental Levels Of 129I Present In Bovine Thyroid And Fresh Water In Argentina

Concentrations of {sup 129}I in bovine thyroid and fresh water samples coming from all over Argentina were analyzed by Accelerator Mass Spectrometry (AMS) and total iodine present in samples by Gas Chromatography (GC) and Inductive Coupled Plasma Mass Spectrometry (ICP-MS), respectively. Once we complete this study, it will be the first set of data of this kind from an extended region of the south American subcontinent.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗
DOE OSTI2010

Auger electron spectroscopy for the determination of sex and age related Ca/P ratio at different bone sites

The Ca/P ratio of normal cortical and trabecular rat bone was measured by Auger electron spectroscopy (AES). Semiquantitative analysis was carried out using ratio techniques to draw conclusions on how age, sex and bone site affect the relative composition of calcium and phosphorus. Results show that Ca/P ratio is not sex dependent; quite the opposite, bone sites exhibit variations in elemental stoichiometry where femoral sections demonstrate higher Ca/P ratio than rear and front tibias. Age-related changes are more distinct for cortical bone in comparison with the trabecular bone. The latter's Ca/P ratio remains unaffected from all the parameters under study. This study confirms that AES is able to successfully quantify bone mineral main elements when certain critical points, related to the experimental conditions, are addressed effectively.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2010

Breast Cancer Risk Estimation Using Parenchymal Texture Analysis in Digital Breast Tomosynthesis

Mammographic parenchymal texture has been shown to correlate with genetic markers of developing breast cancer. Digital breast tomosynthesis (DBT) is a novel x-ray imaging technique in which tomographic images of the breast are reconstructed from multiple source projections acquired at different angles of the x-ray tube. Compared to digital mammography (DM), DBT eliminates breast tissue overlap, offering superior parenchymal tissue visualization. We hypothesize that texture analysis in DBT could potentially provide a better assessment of parenchymal texture and ultimately result in more accurate assessment of breast cancer risk. As a first step towards validating this hypothesis, we investigated the association between DBT parenchymal texture and breast percent density (PD), a known breast cancer risk factor, and compared it to DM. Bilateral DBT and DM images from 71 women participating in a breast cancer screening trial were analyzed. Filtered-backprojection was used to reconstruct DBT tomographic planes in 1 mm increments with 0.22 mm in-plane resolution. Corresponding DM images were acquired at 0.1 mm pixel resolution. Retroareolar regions of interest (ROIs) equivalent to 2.5 cm{sup 3} were segmented from the DBT images and corresponding 2.5 cm{sup 2} ROIs were segmented from the DM images. Breast PD was mammographically estimated using the Cumulus scale. Overall, DBT texture features demonstrated a stronger correlation than DM to PD. The Pearson correlation coefficients for DBT were r = 0.40 (p<0.001) for contrast and r = -0.52 (p<0.001) for homogeneity; the corresponding DM correlations were r = 0.26 (p = 0.002) and r = -0.33 (p<0.001). Multiple linear regression of the texture features versus breast PD also demonstrated significantly stronger associations in DBT (R{sup 2} = 0.39) compared to DM (R{sup 2} = 0.33). We attribute these observations to the superior parenchymal tissue visualization in DBT. Our study is the first to perform DBT texture analysis in a screening population of women, showing that DBT could potentially provide better breast cancer risk assessment in the future.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Association Study between Lead and Zinc Accumulation at Different Physiological Systems of Cattle by Canonical Correlation and Canonical Correspondence Analyses

Pb pollution from automobile exhausts around highways is a persistent problem in India. Pb intoxication in mammalian body is a complex phenomenon which is influence by agonistic and antagonistic interactions of several other heavy metals and micronutrients. An attempt has been made to study the association between Pb and Zn accumulation in different physiological systems of cattles (n = 200) by application of both canonical correlation and canonical correspondence analyses. Pb was estimated from plasma, liver, bone, muscle, kidney, blood and milk where as Zn was measured from all these systems except bone, blood and milk. Both statistical techniques demonstrated that there was a strong association among blood-Pb, liver-Zn, kidney-Zn and muscle-Zn. From observations, it can be assumed that Zn accumulation in cattles' muscle, liver and kidney directs Pb mobilization from those organs which in turn increases Pb pool in blood. It indicates antagonistic activity of Zn to the accumulation of Pb. Although there were some contradictions between the observations obtained from the two different statistical methods, the overall pattern of Pb accumulation in various organs as influenced by Zn were same. It is mainly due to the fact that canonical correlation is actually a special type of canonical correspondence analyses where linear relationship is followed between two groups of variables instead of Gaussian relationship.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2010

Interpretation of the Moessbauer Spectra of the Magnetic Nanoparticles in Mouse Spleen

We have developed a stochastic model for description of relaxation effects in the system of homogeneously magnetized single-domain particles and applied the model to the analysis of Moessbauer spectra of magnetic nanoparticles (Chemicell ARA) and mouse spleen after i.v. injection into animals. We estimate that the fraction of exogenous iron in nanoparticles in the mouse spleen 3 months after injection was 0.27{+-}0.03. The spectra of the residual nanoparticles in the spleen had almost the same isomer shift but smaller mean hyperfine magnetic field values indicating decrease in the magnetic anisotropy energy (size) of the particles compared to the initial ones in the course of biodegradation. Concentration of ferritin-like iron was about three-fold higher than that in the spleen of untreated animals showing ferritin-like forms in the mouse spleen.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2010

Dosimetry of a Small-Animal Irradiation Model using a 6 MV Linear Accelerator

A custom made rat-like phantom was used to measure dose distributions using a 6 MV linear accelerator. The phantom has air cavities that simulate the lungs and cylindrical inserts that simulate the backbone. The calculated dose distributions were obtained with the BrainScan v.5.31 TPS software. For the irradiation two cases were considered: (a) near the region where the phantom has two air cavities that simulate the lungs, and (b) with an entirely uniform phantom. The treatment plan consisted of two circular cone arcs that imparted a 500 cGy dose to a simulated lesion in the backbone. We measured dose distributions using EBT2 GafChromic film and an Epson Perfection V750 scanner working in transmission mode. Vertical and horizontal profiles, isodose curves from 50 to 450 cGy, dose and distance to agreement (DTA) histograms and Gamma index were obtained to compare the dose distributions using DoseLab v4.11. As a result, these calculations show very good agreement between calculated and measured dose distribution in both cases. With a 2% 2 mm criteria 100% of the points pass the Gamma test for the uniform case, while 98.9% of the points do it for the lungs case.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Irradiation Design for an Experimental Murine Model

In radiotherapy and stereotactic radiosurgery, small animal experimental models are frequently used, since there are still a lot of unsolved questions about the biological and biochemical effects of ionizing radiation. This work presents a method for small-animal brain radiotherapy compatible with a dedicated 6MV Linac. This rodent model is focused on the research of the inflammatory effects produced by ionizing radiation in the brain. In this work comparisons between Pencil Beam and Monte Carlo techniques, were used in order to evaluate accuracy of the calculated dose using a commercial planning system. Challenges in this murine model are discussed.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Prevalence of Adverse Effects Post-Brachytherapy on Women with Uterine Cervix Cancer in Durango, Mexico

This work aimed at determining the local prevalence of adverse effects on women with CaCu that recieved LDR brachytherapy treatment at CECAN. The data was extracted from the patient's and medical physics' departement records. Non Gaussian statistics was used due to dose distribution characteristics. A total of 103 patients were studied with average age of 55{+-}13 years and Ia-IV FIGO clinical clasification. The observed prevalence is higher than that reported by other studies. It was observed that patients with proctitis were prescribed a slightly higher dose than those without adverse effects (90% confidence). Patients with proctitis also presented higher age (95% confidence) when compared with the mean of the studied population. The inverse applies to the group with other adverse effects, its average age is lower than the mean (90% confidence).

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Dosimetric evaluation for exposure of patient to a z-gradient coil in magnetic resonance imaging

In magnetic resonance imaging, time-varied gradient magnetic fields may stimulate nerves and muscles by inducing electric fields and currents in patients, which may potentially cause health problems. In this paper, a realistic z-gradient coil was numerically designed and the exposure level in a 3D real human man model was calculated by using the impedance method. It was found that the z-gradient coil produces a magnetic flux density (B-field) with two regions of good homogeneity along the coil length, separated by a very weak B-field in the middle of the coil. The spatially averaged B-field is 281 times greater than that of the International Commission on Non-Ionizing Radiation Protection's (ICNIRP) reference level. The 1-cm{sup 2}-averaged induced current density in the central nervous system is 87 times greater than that of the ICNIRP's basic restriction. The maximum current density in all of the body tissues is above the nerve stimulation threshold.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Toward a system to measure action potential on mice brain slices with local magnetoresistive probes

This work combines an electrophysiological system with a magnetoresistive chip to measure the magnetic field created by the synaptic/action potential currents. The chip, with 15 spin valve sensors, was designed to be integrated in a recording chamber for submerged mice brain slices used for synaptic potential measurements. Under stimulation (rectangular pulses of 0.1 ms every 10 s) through a concentric electrode placed near the CA3/CA1 border of the hippocampus, the spin valve sensor readout signals with 20 {mu}V amplitude and a pulse length of 20 to 30 ms were recorded only in the pyramidal cell bodies region and can be interpreted as being derived from action potentials/currents.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗