943 resultados para pacs: equipment and software evaluation methods


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The prototypes for tumor targeting with radiolabeled peptides are derivatives of somatostatin. Usually, they primarily have high affinity for somatostatin receptor subtype 2 (sst2), and they have moderate affinity for sst5. We aimed at developing analogs that recognize different somatostatin receptor subtypes for internal radiotherapy in order to extend the present range of accessible tumors. We synthesized DOTA-octapeptides based on octreotide by replacing Phe3 mainly with unnatural amino acids. The affinity profile was determined by using cell lines transfected with sst1-5. Internalization was determined by using AR42J, HEK-sst3, and HEK-sst5 cell lines, and biodistribution was studied in rat tumor models. Two of the derivatives thus obtained showed an improved binding affinity profile, enhanced internalization into cells expressing sst2 and sst3, respectively, and better tumor:kidney ratios in animals.

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OBJECTIVES: To develop and evaluate a short form of the 24-item Geriatric Pain Measure (GPM) for use in community-dwelling older adults. DESIGN: Derivation and validation of a 12-item version of the GPM in a European and an independent U.S. sample of community-dwelling older adults. SETTING: Three community-dwelling sites in London, United Kingdom; Hamburg, Germany; Solothurn, Switzerland; and two ambulatory geriatrics clinics in Los Angeles, California. PARTICIPANTS: European sample: 1,059 community-dwelling older persons from three sites (London, UK; Hamburg, Germany; Solothurn, Switzerland); validation sample: 50 persons from Los Angeles, California, ambulatory geriatric clinics. MEASUREMENTS: Multidimensional questionnaire including self-reported demographic and clinical information. RESULTS: Based on item-to-total scale correlations in the European sample, 11 of 24 GPM items were selected for inclusion in the short form. One additional item (pain-related sleep problems) was included based on clinical relevance. In the validation sample, the Cronbach alpha of GPM-12 was 0.92 (individual subscale range 0.77-0.92), and the Pearson correlation coefficient (r) between GPM-12 and the original GPM was 0.98. The correlation between the GPM-12 and the McGill Pain Questionnaire was 0.63 (P<.001), similar to the correlation between the original GPM and the McGill Pain Questionnaire (Pearson r=0.63; P<.001). Exploratory factor analysis indicated that the GPM-12 covers three subfactors (pain intensity, pain with ambulation, disengagement because of pain). CONCLUSION: The GPM-12 demonstrated good validity and reliability in these European and U.S. populations of older adults. Despite its brevity, the GPM-12 captures the multidimensional nature of pain in three subscales. The self-administered GPM-12 may be useful in the clinical assessment process and management of pain and in pain-related research in older persons.

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The amount and type of ground cover is an important characteristic to measure when collecting soil disturbance monitoring data after a timber harvest. Estimates of ground cover and bare soil can be used for tracking changes in invasive species, plant growth and regeneration, woody debris loadings, and the risk of surface water runoff and soil erosion. A new method of assessing ground cover and soil disturbance was recently published by the U.S. Forest Service, the Forest Soil Disturbance Monitoring Protocol (FSDMP). This protocol uses the frequency of cover types in small circular (15cm) plots to compare ground surface in pre- and post-harvest condition. While both frequency and percent cover are common methods of describing vegetation, frequency has rarely been used to measure ground surface cover. In this study, three methods for assessing ground cover percent (step-point, 15cm dia. circular and 1x5m visual plot estimates) were compared to the FSDMP frequency method. Results show that the FSDMP method provides significantly higher estimates of ground surface condition for most soil cover types, except coarse wood. The three cover methods had similar estimates for most cover values. The FSDMP method also produced the highest value when bare soil estimates were used to model erosion risk. In a person-hour analysis, estimating ground cover percent in 15cm dia. plots required the least sampling time, and provided standard errors similar to the other cover estimates even at low sampling intensities (n=18). If ground cover estimates are desired in soil monitoring, then a small plot size (15cm dia. circle), or a step-point method can provide a more accurate estimate in less time than the current FSDMP method.

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Understanding the canopy cover of an urban environment leads to better estimates of carbon storage and more informed management decisions by urban foresters. The most commonly used method for assessing urban forest cover type extent is ground surveys, which can be both timeconsuming and expensive. The analysis of aerial photos is an alternative method that is faster, cheaper, and can cover a larger number of sites, but may be less accurate. The objectives of this paper were (1) to compare three methods of cover type assessment for Los Angeles, CA: handdelineation of aerial photos in ArcMap, supervised classification of aerial photos in ERDAS Imagine, and ground-collected data using the Urban Forest Effects (UFORE) model protocol; (2) to determine how well remote sensing methods estimate carbon storage as predicted by the UFORE model; and (3) to explore the influence of tree diameter and tree density on carbon storage estimates. Four major cover types (bare ground, fine vegetation, coarse vegetation, and impervious surfaces) were determined from 348 plots (0.039 ha each) randomly stratified according to land-use. Hand-delineation was better than supervised classification at predicting ground-based measurements of cover type and UFORE model-predicted carbon storage. Most error in supervised classification resulted from shadow, which was interpreted as unknown cover type. Neither tree diameter or tree density per plot significantly affected the relationship between carbon storage and canopy cover. The efficiency of remote sensing rather than in situ data collection allows urban forest managers the ability to quickly assess a city and plan accordingly while also preserving their often-limited budget.

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Chronic diarrhea is defined as a decrease in fecal consistency lasting for four or more weeks. A myriad of disorders are associated with chronic diarrhea. In developed countries, chronic diarrhea is mostly caused by non-infectious diseases. There are four pathogenic mechanisms leading to chronic diarrhea: osmotic diarrhea, secretory diarrhea, inflammatory diarrhea, and dysmotility. Overlaps between these mechanisms are possible. A 72-hour fecal collection as well as the fasting test are important diagnostic tools to identify the underlying pathomechanism. The identification of the pathomechanism narrows down the possible etiologies of chronic diarrhea and allows therefore a cost-saving diagnostic workup. The endoscopy is well established in the workup of chronic diarrhea. This article gives an overview about the main causes and mechanisms leading to chronic diarrhea and proposes an algorithm for the diagnostic evalution.

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Montana's oil and gas industries aggregate a gross income of over 12,000,000 annually to the state. Oil and gas fields have been thoroughly discussed in liter­ature as to geology, location, production and future possibilities. The specific object of this report has been to compile a comprehensive study of the production methods as they occur.

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Over the past several decades, it has become apparent that anthropogenic activities have resulted in the large-scale enhancement of the levels of many trace gases throughout the troposphere. More recently, attention has been given to the transport pathway taken by these emissions as they are dispersed throughout the atmosphere. The transport pathway determines the physical characteristics of emissions plumes and therefore plays an important role in the chemical transformations that can occur downwind of source regions. For example, the production of ozone (O3) is strongly dependent upon the transport its precursors undergo. O3 can initially be formed within air masses while still over polluted source regions. These polluted air masses can experience continued O3 production or O3 destruction downwind, depending on the air mass's chemical and transport characteristics. At present, however, there are a number of uncertainties in the relationships between transport and O3 production in the North Atlantic lower free troposphere. The first phase of the study presented here used measurements made at the Pico Mountain observatory and model simulations to determine transport pathways for US emissions to the observatory. The Pico Mountain observatory was established in the summer of 2001 in order to address the need to understand the relationships between transport and O3 production. Measurements from the observatory were analyzed in conjunction with model simulations from the Lagrangian particle dispersion model (LPDM), FLEX-PART, in order to determine the transport pathway for events observed at the Pico Mountain observatory during July 2003. A total of 16 events were observed, 4 of which were analyzed in detail. The transport time for these 16 events varied from 4.5 to 7 days, while the transport altitudes over the ocean ranged from 2-8 km, but were typically less than 3 km. In three of the case studies, eastward advection and transport in a weak warm conveyor belt (WCB) airflow was responsible for the export of North American emissions into the FT, while transport in the FT was governed by easterly winds driven by the Azores/Bermuda High (ABH) and transient northerly lows. In the fourth case study, North American emissions were lofted to 6-8 km in a WCB before being entrained in the same cyclone's dry airstream and transported down to the observatory. The results of this study show that the lower marine FT may provide an important transport environment where O3 production may continue, in contrast to transport in the marine boundary layer, where O3 destruction is believed to dominate. The second phase of the study presented here focused on improving the analysis methods that are available with LPDMs. While LPDMs are popular and useful for the analysis of atmospheric trace gas measurements, identifying the transport pathway of emissions from their source to a receptor (the Pico Mountain observatory in our case) using the standard gridded model output, particularly during complex meteorological scenarios can be difficult can be difficult or impossible. The transport study in phase 1 was limited to only 1 month out of more than 3 years of available data and included only 4 case studies out of the 16 events specifically due to this confounding factor. The second phase of this study addressed this difficulty by presenting a method to clearly and easily identify the pathway taken by only those emissions that arrive at a receptor at a particular time, by combining the standard gridded output from forward (i.e., concentrations) and backward (i.e., residence time) LPDM simulations, greatly simplifying similar analyses. The ability of the method to successfully determine the source-to-receptor pathway, restoring this Lagrangian information that is lost when the data are gridded, is proven by comparing the pathway determined from this method with the particle trajectories from both the forward and backward models. A sample analysis is also presented, demonstrating that this method is more accurate and easier to use than existing methods using standard LPDM products. Finally, we discuss potential future work that would be possible by combining the backward LPDM simulation with gridded data from other sources (e.g., chemical transport models) to obtain a Lagrangian sampling of the air that will eventually arrive at a receptor.