898 resultados para Pulmonary nodule


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This study was supported financially by an unrestricted grant from Teva Pharmaceuticals, Frazer, PA, USA. The authors thank Jenny Fanstone of Fanstone Medical Communications Ltd., UK, and Elizabeth V Hillyer for medical writing support, funded by Research in Real-Life. We acknowledge with gratitude Dr Ruchir Parikh for his review of and contributions to the manuscript.

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Sildenafil is a phosphodiesterase type-5 inhibitor approved for treatment of pulmonary arterial hypertension (PAH) in adults. Data from pediatric trials demonstrate a similar acute safety profile to the adult population but have raised concerns regarding the safety of long-term use in children. Interpretation of these trials remains controversial with major regulatory agencies differing in their recommendations - the US Food and Drug Administration recommends against the use of sildenafil for treatment of PAH in children, while the European Medicines Agency supports its use at "low doses". Here, we review the available pediatric data regarding dosing, acute, and long-term safety and efficacy of sildenafil for the treatment of PAH in children.

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The aim of this study was to explore symptom burden and its relationship to functional performance in patients with COPD. A descriptive, cross-sectional, correlational survey design was used and a sample of 214 patients with COPD. The sample was recruited from patients attending one of the major teaching hospitals in Dublin. Symptom burden was measured using the Memorial Symptom Assessment Scale (MSAS), and the functional performance was measured using the Functional Performance Inventory-Short Form (FPISF). Findings revealed that participants experienced a median of 13 symptoms. The most burdensome symptoms were shortness of breath, lack of energy, difficulty sleeping, worrying, dry mouth, feeling nervous, feeling irritable, and feeling sad. Participants with very severe COPD had the greatest symptom burden, followed by those with severe COPD, moderate COPD, and mild COPD. Symptom burden was higher for the psychological symptoms compared to the physical symptoms. Participants with mild COPD had the highest functional performance, followed by those with moderate COPD, very severe COPD, and severe COPD. Twenty symptoms were negatively correlated with overall functional performance, indicating that high symptom burden for those symptoms was associated with low overall functional performance. Moderate, negative, statistically significant correlations were found between the total symptom burden and overall functional performance, physical symptom burden and overall functional performance and psychological symptom burden and overall functional performance. A negative linear relationship was found between total symptom burden and overall functional performance among all stages of COPD except the mild group. No relationship was found between total symptom burden and overall functional performance for the moderate group. Healthcare professionals need to broaden the clinical and research assessment of physical and psychological symptoms in COPD; alleviating the burden of these symptoms may promote improved functional performance.

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The minor-element composition of concentric layers within a single ferromanganese nodule from the eastern North Pacific exhibits strong correlations with Fe and Mn contents but appears to be independent of pronounced mineralogic variations. On the basis of these correlations, the elemental composition of individual layers apparently is controlled by the relative contribution of two sources: seawater, and interstitial water of associated sediment. In contrast, the mineralogy of the nodule, consisting of birnessite in the outer few layers and todorokite in the inner layers, is considered to be a function of nodule diagenesis.

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C. W. Gümbel received nodules from J. Murray which were collected at a depth of 2740 fathoms, between Japan and the Sandwich Islands, by the "Challenger" Expedition. They were either round or long in shape, with a dull, dirty-brown coloured surface, and enclosed fragments of pumice-stone, and more rarely teeth of sharks or fragments of mussels. They were analysed by A. Schwager.

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Two Pacific Ocean manganese nodules, one from the ocean basin and one from a sea-mount, were examined in transmission electron microscopes at 100 and 650 kV. Of the many specimens examined, ten electron diffraction crystal spot patterns were identified. Sodium birnessite was observed six times and todorokite, Giavanoli's synthetic birnessite, hydrohausmanite and -Fe2O3 one time each. Ferric hydroxide was synthesized in the laboratory and shown to be the same as the primary iron mineral observed in the manganese nodules. The ferric hydroxide had a particle size range from 30 to 450 ?. Manganese oxide particles were frequently embedded in a mass of smaller ferric hydroxide particles.

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Processes of authigenic manganese ore formation in sediments of the North Equatorial Pacific are considered on the basis of a study of the surface layer (<2 mm) of a ferromanganese nodule and four micronodule size fractions from associated surface sediment (0-7 cm). Inhomogeneity of nodule composition is shown. Mn/Fe ratio is maximal in samples from lateral sectors of the nodule at the water-sediment interface. Compositional differences of nodules are related to preferential accumulation of trace elements in iron oxyhydroxides (P, Sr, Pb, U, Bi, Th, Y, and REE), manganese hydroxides (Co, Ni, Cu, Zn, Cd, Mo, Tl, W), and lithogenic component trapped during nodule growth (Ga, Rb, Ba, and Cs). Ce accumulation in the REE composition is maximal in the upper and lower parts of the nodule characterized by minimal Mn/Fe values. A compositional comparison of manganese micronodules and surface layers of the nodule demonstrates that micronodule material was subjected to more intense reworking during diagenesis of sediments. The micronodules are characterized by higher Mn/Fe and P/Fe, but lower Ni/Cu and Co/Ni ratios. The micronodules and nodules do not differ in terms of contents of Ce and Th that are the least mobile elements during diagenesis. Differences in chemical composition of the micronodules and nodules are related not only to additional input of Mn in the process of diagenesis, but also to transformation of iron oxyhydroxides after removal of Mn from the close association with Fe formed in suspended matter during sedimentation.

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Hydrogenous manganese nodules form on the ocean floor by slow authigenic precipitation (1-6 mm/Ma) of the oxyhydroxides of manganese and iron that continuously scavenge trace elements from the marine environment. Consequently, these nodules represent independent marine deposits useful for the study of the chemical signatures of the paleomarine environments. The results presented are a continuation of a study of the Zetes-3D nodule from the Pacific Ocean. It is a large (24x17x10 cm) hydrogenous nodule whose slow growth rate of 1.3 mm/Ma was detremined using 10Be techniques. A positive cerium anomaly is observed throughout the nodule and its Ir content indicates a sharp spike at 54-62 Ma in fair agreement with the K-T event.

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During June-August 1970 geologic investigations were carried out to the west of the Cape Verde Islands. One result of these investigations was a discovery of a new region of distribution of iron-manganese nodules. Data on chemical analysis of the nodules and their morphometric characteristics are presented in this paper. The report is illustrated by bottom-relief profiles, underwater photographs, and tables.

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A large manganese nodule (manganese slab) was dredged from 2100 m on the Scott Plateau by R.V. Valdivia in 1977. It is an irregular ellipsoid, with a maximum dimension of 28 cm, parallel to the sea floor. Chemical analyses show that Mn and Fe proportions are comparable, and total Ni + Cu + Co content averages 0.7%. The nodule has a complex growth history which started with radial upward growth leading to coalescing into a continuous crust. The crust was coated with horizontal layers. After fracturing and infilling of cracks with calcareous sediment, further layers encased the nodule.

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The area surveyed during project AMC-11-67 was the portion of the Blake Plateau between latitude 30°00'N and 33°00'N and between the 100 to 1000 fathom curves. The survey was conducted from 3 October until 18 October 1967. Survey operations included dredgings, camera and multi-sensor lowerings. A collection of manganese and phosphate concretions as well as coral and sediment samples were examined by the ESSA(NOAA) Atlantic Oceanographic Laboratories. Chemical analyses were conducted at the NASA Manned Spacecraft Center, Houston by Richard A. Laidley for X-Ray Fluorescence Analysis and H. Costello for Atomic Absorption Analysis. Later the whole collection of samples was transferred to the Smithsonian National Museum of Natural History were it is available for study (see, http://mineralsciences.si.edu/collections.htm).

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The rate of accumulation of a ferromanganese coating on a fragment of pillow basalt was estimated using a variety of techniques. Unsupported 230 Th activity decrease in the oxide layer, K/A dating of the basalt, fission tracks dating of the glassy layer around the basalt, thickness of the palagonitization rind, and integrated 230 Th activity give ages from approximately 3 x 10-6 years to 5 x 10-3 years. Data suggest that the ferromanganese material formed rapidly (33 mm/10-6 years) and by hydrothermal or volcanic processes.