876 resultados para silver-loaded TiO2


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The Red Lodge and Silver Star chromite deposits of Montana have stimulated much interest during periods of war. The Red Lodge deposit is 25 miles southwest of Red Lodge which is also the nearest railroad point. Several workings are scattered throughout the area, exposing lense-like ore bodies averaging 33% chrome oxide. Silver Star is a much smaller deposit 5 miles west of Silver Star, Montana, which is its nearest rail­road point. Lenses of chromite are exposed by pits and trench­es, which average approximately 36% chromic oxide.

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Silver Bow Creek runs approximately 25 miles from Butte to Warm Springs, where it joins Warm Springs Creek to form the Clark Fork River. This historic creek was terribly contaminated with mine wastes around the turn of the 20th century, leaving many "slickens" that persisted into the 21st century, when it became a Superfund remediation project. More than 5.5 million cubic yards of stream-deposited mine waste have been removed and 1,650 acres revegetated. Chief contaminants are copper, zinc, and arsenic, but acidic soils are often equally or more limiting to plants. The stream was relocated, and mine wastes were replaced with biologically inert cover soil. Richard A. Prodgers is currently a plant ecologist with Bighorn Environmental Sciences in Dillon, Montana.

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The purpose of this project is to take preliminary steps towards the development of a QUAL2Kw model for Silver Bow Creek, MT. These preliminary steps include initial research and familiarization with QUAL2Kw, use of ArcGIS to fill in geospatial data gaps, and integration of QUAL2Kw and ArcGIS. The integration involves improvement of the QUAL2Kw model output through adding functionality to the model itself, and development of a QUAL2Kw specific tool in ArcGIS. These improvements are designed to help expedite and simplify the viewing of QUAL2Kw output data spatially in ArcGIS as opposed to graphically within QUAL2Kw. These improvements will allow users to quickly and easily view the many output parameters of each model run geographically within ArcGIS. This will make locating potential problem areas or “hot spots” much quicker and easier than interpreting the QUAL2Kw output data from a graph alone. The added functionality of QUAL2KW was achieved through the development of an excel Macro, and the tool in ArcGIS was developed using python scripting and the model builder feature in ArcGIS.

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The wartime demand for fluorspar has caused renewed interest in fluorite deposits. Near Silver Bow, Montana, a deposit of massive, coarsely crystalline fluorspar, which has not been described in the literature, has attracted the atten­tion of the United States Geological Survey.

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The Mike Horse mine, in the Huddelston mining district, is fifty-two miles northwest of Helena, Montana. The mine was discovered in 1898 by Joseph Heitmiller. There was only minor production from the date of discovery until 1915; the main drawback being lack of good road.

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BACKGROUND: One way to evaluate various implant restorations is to measure the amount of bone change that occurs at the crestal bone. The objective of this study was to histologically evaluate the alveolar bone change around a bone-level, non-matching implant-abutment diameter configuration that incorporated a horizontal offset and a Morse taper internal connection. METHODS: The study design included extraction of all mandibular premolars and first molars in five canines. After 3 months, 12 dental implants were placed at three levels in each dog: even with the alveolar crest, 1 mm above the alveolar crest, and 1 mm below the alveolar crest. The implants were submerged on one side of the mandible. On the other side, healing abutments were exposed to the oral cavity (non-submerged). Gold crowns were attached 2 months after implant placement. The dogs were sacrificed 6 months postloading, and specimens were processed for histologic and histometric analyses. RESULTS: Evaluation of the specimens indicated that the marginal bone remained near the top of the implants under submerged and non-submerged conditions. The amount of bone change for submerged implants placed even with, 1 mm below, and 1 mm above the alveolar crest was -0.34, -1.29, and 0.04 mm, respectively (negative values indicate bone loss). For non-submerged implants, the respective values were -0.38, -1.13, and 0.19 mm. For submerged and non-submerged implants, there were significant differences in the amount of bone change among the three groups (P <0.05). The percentage of bone-to-implant contact for submerged implants was 73.3%, 71.8%, and 71.5%. For non-submerged implants, the respective numbers were 73.2%, 74.5%, and 76%. No significant differences occurred with regard to the percentage of bone contact. CONCLUSIONS: Minimal histologic bone loss occurred when dental implants with non-matching implant-abutment diameters were placed at the bone crest and were loaded for 6 months in the canine. The bone loss was significantly less (five- to six-fold) than that reported for bone-level implants with matching implant-abutment diameters (butt-joint connections).

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Indocyanine green (ICG) is a chemically labile compound which needs to be stabilized in aqueous media to be used in biomedical applications. In the present study, poly(ε-caprolactone) (PCL), a semi-crystalline polyester, was used to encapsulate and stabilize ICG in a hydrophobic environment. A hydrophobic and biocompatible nanocomposite was obtained by the process of encapsulating inorganic silica. ICG was embedded in the hydrophobic polymer coating by starting from a well-defined silica (Si) core of either 80 nm or 120 nm diameter, which served as a template for a ‘grafting from’ approach using ε-caprolactone. The obtained nanocomposite Si grafted PCL/ICG was based on silica nanoparticles grafted with PCL, in which ICG was adsorbed. The nanoparticles were characterized by IR spectroscopy, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The change in the surface charge and the colloidal stability of the nanoparticles was followed by zeta potential measurements. This approach of synthesizing nanocomposite-based ICG demonstrates a new route to stabilize ICG. We synthesized biocompatible nanoparticles containing a high ICG concentration and exhibiting excellent stability to aqueous decomposition.

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OBJECTIVE: (1) To describe the ultrasonographic appearance of multiple congenital ocular anomalies (MCOA) in the eyes of horses with the PMEL17 (Silver) mutant gene. (2) To compare the accuracy of B-mode ocular ultrasound to conventional direct ophthalmoscopy. ANIMALS STUDIED: Sixty-seven Comtois and 18 Rocky Mountain horses were included in the study. PROCEDURES: Horses were classified as being carriers or noncarriers of the PMEL17 mutant allele based on coat color or genetic testing. Direct ophthalmoscopy followed by standardized ultrasonographic examination was performed in all horses. RESULTS: Seventy-five of 85 horses (88.24%) carried at least one copy of the Silver mutant allele. Cornea globosa, severe iridal hypoplasia, uveal cysts, cataracts, and retinal detachment could be appreciated with ultrasound. Carrier horses had statistically significantly increased anterior chamber depth and decreased thickness of anterior uvea compared with noncarriers (P < 0.05). Uveal cysts had a wide range of location and ultrasonographic appearances. In 51/73 (69.86%) carrier horses, ultrasound detected ciliary cysts that were missed with direct ophthalmoscopy. CONCLUSIONS: In this study, ultrasonography was useful to identify uveal cysts in PMEL17 mutant carriers and to assess anterior chamber depth.

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The role of Pleistocene glacial cycles in forming the contemporary genetic structure of organisms has been well studied in China with a particular focus on the Tibetan Plateau. However, China has a complex topography and diversity of local climates, and how glacial cycles may have shaped the subtropical and tropical biota of the region remains mostly unaddressed. To investigate the factors that affected the phylogeography and population history of a widely distributed and nondeciduous forest species, we analysed morphological characters, mitochondrial DNA sequences and nuclear microsatellite loci in the Silver Pheasant (Lophura nycthemera). In a pattern generally consistent with phenotypic clusters, but not nominal subspecies, deeply divergent mitochondrial lineages restricted to different geographic regions were detected. Coalescent simulations indicated that the time of main divergence events corresponded to major glacial periods in the Pleistocene and gene flow was only partially lowered by drainage barriers between some populations. Intraspecific cytonuclear discordance was revealed in mitochondrial lineages from Hainan Island and the Sichuan Basin with evidence of nuclear gene flow from neighbouring populations into the latter. Unexpectedly, hybridization was revealed in Yingjiang between the Silver Pheasant and Kalij Pheasant (Lophura leucomelanos) with wide genetic introgression at both the mtDNA and nuclear levels. Our results highlight a novel phylogeographic pattern in a subtropical area generated from the combined effects of climate oscillation, partial drainage barriers and interspecific hybridization. Cytonuclear discordance combined with morphological differentiation implies that complex historical factors shaped the divergence process in this biodiversity hot spot area of southern China.