Occurrences of dendritic gold at the McLaughlin Mine hot-spring gold deposit

Science.gov (United States)

Sherlock, R. L.; Lehrman, N. J.

1995-06-01

Two styles of gold dendrites are variably developed at the McLaughlin Mine. The most abundant occurrence is hosted by amber-coloured hydrocarbon-rich opal. Silica likely precipitated from a boiling hydrothermal fluid and complexed with immiscible hydrocarbons forming an amorphous hydrocarbon-silica phase. This phase likely scavenged particulate gold by electrostatic attraction to the hydrocarbon-silica phase. The dendritic nature of the gold is secondary and is the result of dewatering of the amorphous hydrocarbon-silica phase and crystallization of gold into syneresis fractures. The second style of dendritic gold is hosted within vein swarms that focused large volumes of fluid flow. The dendrites occur along with hydrocarbon-rich silica at the upper contact of the vein margins which isolated the dendrites allowing sufficient time for them to grow. In a manner similar to the amber-coloured opal, the dendrites may have formed by scavenging particulate gold by electrostatic attraction to the hydrocarbon-silica phase.

Genesis and gold (Copper) Potential in Darestan-Baghu mining area (South of Damghan)

International Nuclear Information System (INIS)

Tajeddin, H. A.; Rashid Nezhad Omran, N.; Babakhani, A. R.

2000-01-01

Darestan-Baghu gold mining area is exposed at about 100 km south of Damghan. The area is a part of Torud-Chahshirin volcano-plutonic belt that crops out as a ho rst with a N E-S W trend in the northern limit Dasht-e-Kavir. The outcrops in the area are Middle-Eocene volcano-pyroclastics with andesite to da cite in composition, which are intruded by a number of intrusive s including granite to granodiorite bodies. Mineralization in Darestan gold occurrence consists of a copper (gold)-bearing silicic vein with 400 meter length occurring within a N-S trending normal fault in andesitic to dacitic- andesitic massive breccia tuff associated with silicic, argillic and propylitic alterations. Mineralization in the vein includes quartz, chalcopyrite, pyrite, gold, specularite, malachite, and iron-hydroxides. Gold mineralization in Baghu vein (at about 3 km N E of Darestan gold occurrence) is as a silicic vein with 700 meter length occurring within a granodiorite-granite sub volcanic with argillic alteration. Mineralization in Baghu vein consists of quartz, pyrite, chalcopyrite, gold, iron oxides and iron-hydroxides, malachite, chalcocite, covellite and tourmaline. Field observations indicate that considerable contents of gold in Darestan area mainly related to sulfide-bearing silicic veins are intruded within N-S normal faults that are generally associated with hydrothermal alteration of argillic, silicic and chloritic (± epi dote) zones. investigation on other mineralized zones of Darestan and Baghu areas suggests a clear genetic relationship between Darestan copper (gold) occurrence and gold-bearing silicic vein of Baghu. Field observations and laboratory studies show a close relationship between the copper (gold) mineralization and late-stage silicic solutions induced from sub volcanic intrusive s with acidic to intermediate composition in Darestan and Baghu districts. Some of the most important lines of evidence are spatial relationship between ore-bearing silicic veins

Flash vaporization during earthquakes evidenced by gold deposits

Science.gov (United States)

Weatherley, Dion K.; Henley, Richard W.

2013-04-01

Much of the world's known gold has been derived from arrays of quartz veins. The veins formed during periods of mountain building that occurred as long as 3 billion years ago, and were deposited by very large volumes of water that flowed along deep, seismically active faults. The veins formed under fluctuating pressures during earthquakes, but the magnitude of the pressure fluctuations and their influence on mineral deposition is not known. Here we use a simple thermo-mechanical piston model to calculate the drop in fluid pressure experienced by a fluid-filled fault cavity during an earthquake. The geometry of the model is constrained using measurements of typical fault jogs, such as those preserved in the Revenge gold deposit in Western Australia, and other gold deposits around the world. We find that cavity expansion generates extreme reductions in pressure that cause the fluid that is trapped in the jog to expand to a very low-density vapour. Such flash vaporization of the fluid results in the rapid co-deposition of silica with a range of trace elements to form gold-enriched quartz veins. Flash vaporization continues as more fluid flows towards the newly expanded cavity, until the pressure in the cavity eventually recovers to ambient conditions. Multiple earthquakes progressively build economic-grade gold deposits.

isotopic chronological study on gold-stibium deposits in Bayinbuluke area of Tianshan mountains

International Nuclear Information System (INIS)

Chen Fuwen; Li Huaqin

2003-01-01

Several gold-stibium deposits have recently been found in Bayinbuluke area of Tianshan Mountains, such as the Dashankou gold deposit and Chahansala stibium deposit. isotopic chronological study of mineralization show that the fluid inclusion Rb-Sr isochron age for gold-bearing pyrite-quartz veins and pyrite-limonite-quartz veins from the Dashankou gold mine are 354 ± 8.1 Ma (2 σ) and 344 ± 21 Ma (2 σ), respectively. The two ages are consistent in test errors, indicating the gold deposit was formed in early Carboniferous and related to regional shearing; the fluid inclusion Rb-Sr isochron age for quartz-stibnite veins and quartz-tetrahedrite-bismuthinite-stibnite veins from the Chahansala stibium mine is 257 ± 23 Ma (2 σ), indicating the deposit was formed during the late Hercynian-Early Indosinian Period and related to intracontinental deformation. (authors)

Evolution of the Bucium Rodu and Frasin magmatic-hydrothermal system, Metaliferi Mountains, Romania

Science.gov (United States)

Iatan, Elena Luisa; Berbeleac, Ion; Visan, Madalina; Minut, Adrian; Nadasan, Laurentiu

2013-04-01

The Miocene Bucium Rodu and Frasin maar-diatreme structures and related Au-Ag epithermal low sulfidation with passing to mesothermal mineralizations are located in the Bucium-Rosia Montana-Baia de Aries metallogenetic district, within so called the "Golden Quatrilaterum", in the northeastern part of the Metaliferi Mountains. These structures are situated at about 5 km southeast from Rosia Montana, the largest European Au-Ag deposit. The total reserves for Bucium Rodu-Frasin are estimated at 43.3 Mt with average contents of 1.3 g/t Au and 3 g/t Ag. The Miocene geological evolution of Bucium Rodu and Frasin magmatic-hydrothermal system took place in closely relationships with tectonic, magmatic and metallogenetic activity from Bucium-Rosia Montana-Baia de Aries district in general, and adjacent areas, in special. The hydrothermal alteration is pervasive; adularia followed by phyllic, carbonatization and silicification alterations, usually show a close relationship with the mineralizations. Propylitic alteration occurs dominantly towards the depth; argillic alteration shows a local character. The mineralization occurs in veins, breccias, stockworks and disseminations and is hosted within two volcanic structures emplaced into a sequence of Cretaceous sediments in closely genetically relations with the Miocene phreatomagmatic fracturing and brecciation events. Within Rodu maar-diatreme structure the mineralizations follow especially the contact between the diatreme and Cretaceous flysch. The vein sets with low, moderately and near vertical dippings, cover 400x400m with N-S trend. The most important mineralization style is represented by veins, accompanied by hydrothermal breccias and disseminations. The veins spatial distribution relives as "en echelon" tension veins. They carry gold, minor base metal sulphides (pyrite, chalcopyrite, sphalerite, galena, tetrahedrite, arsenopyrite). Gangue is represented by carbonates (calcite, dolomite, ankerite, siderite, rhodochrosite

Constraints on mineralisation and hydrothermal alteration in the Nalunaq gold deposit, South Greenland

DEFF Research Database (Denmark)

Bell, Robin-Marie Fairbairn

Summary: Nalunaq is located in South Greenland and is a small high gold-grade deposit, which for the majority of its operational life was Greenland's only metalliferous mine. Gold is hosted in narrow quartz veins which are cross-cut by late-stage faults. Gold-quartz veins are hosted by fine...

The wave model of mesothermal plasma near wakes and korteweg-de vries equation

International Nuclear Information System (INIS)

Shen, C.; Liu, V.C.

1982-01-01

The stationary two-dimensional (x,z) near wakes behind a flat-based projectile which moves at a constant mesothermal speed (V sub(infinity)) along a z-axis in a rarefied, fully ionized, plasma is studied using the wave model previously proposed by one of the authors (VCL). One-fluid theory is used to depict the free expansion of ambient plasma into the vacuum produced behind a fast-moving projectile. This nonstationary, one-dimensional (x,t) flow which is approximated by the K-dV equation can be transformed, through substitution, t=z/V sub(infinity), into a stationary two-dimensional(x,z) near wake flow seen by an observer moving with the body velocity (V sub(infinity)). The initial value problem of the K-dV equation in (x,t) variables is solved by a specially devised numerical method. Comparisons of the present numerical solution for the asymptotically small and large times with available analytical solutions are made and found in satisfactory agreements. (author)

Update of endovenous treatment modalities for insufficient saphenous veins-A review of literature

NARCIS (Netherlands)

van Eekeren, Ramon R. J. P.; Boersma, Doeke; de Vries, Jean-Paul P. M.; Zeebregts, Clark J.; Reijnen, Michel M. P. J.

Lower-limb venous insufficiency resulting from saphenous vein incompetence is a common disorder, increasing with age. For decades, surgical stripping of the great saphenous vein has been the gold standard in varicose vein treatment. The desire to optimize outcomes of treatment and reduce surgical

Gold-bearing hydrothermal veins in Chukotka

Energy Technology Data Exchange (ETDEWEB)

Davidenko, N.M.

1980-01-01

Indicators such as the correlation of mineralization to plutonic and vulcanic formations and various facies of metamorphism, the character of the structural-tectonic control of mineralization, characteristics of silica redistribution as well that of calcium, water, and other components in altering ore zones, the specificity of sygenetic fluid inclusions in minerals, morphology, the internal structure and other typomorphic indicators of native gold and its accessories are utilized in the working out of a genetic classification for compiling a complex of diagnostic indicators of post-magmatic mineralization on Chukotka at various depths. Those indicators, in addition to earlier known hydrothermal gold ore formations, can be used to identify still other types of mineralization, particularly pyrite group minerals.

Geology of the Vienna Mineralized Area, Blaine and Camas Counties, Idaho

Science.gov (United States)

Mahoney, J. Brian; Horn, Michael C.

2005-01-01

The Vienna mineralized area of south-central Idaho was an important silver-lead-producing district in the late 1800s and has intermittently produced lead, silver, zinc, copper, and gold since that time. The district is underlain by biotite granodiorite of the Cretaceous Idaho batholith, and all mineral deposits are hosted by the biotite granodiorite. The granodiorite intrudes Paleozoic sedimentary rocks of the Sun Valley Group, is overlain by rocks of the Eocene Challis Volcanic Group, and is cut by numerous northeast-trending Eocene faults and dikes. Two mineralogically and texturally distinct vein types are present in a northwest- and east-trending conjugate shear-zone system. The shear zones postdate granodiorite emplacement and joint formation, but predate Eocene fault and dike formation. Ribbon veins consist of alternating bands of massive vein quartz and silver-sulfide (proustite and pyrargyrite) mineral stringers. The ribbon veins were sheared and brecciated during multiple phases of injection of mineralizing fluids. A quartz-sericite-pyrite-galena vein system was subsequently emplaced in the brecciated shear zones. Both vein systems are believed to be the product of mesothermal, multiphase mineralization. K-Ar dating of shear-zone sericite indicates that sericitization occurred at 80.7?2.8 Ma; thus mineralization in the Vienna mineralized area probably is Late Cretaceous in age.

Geology, geochemistry, and geochronology of the East Bay gold trend, Red Lake, Ontario, Canada

Science.gov (United States)

Gallagher, Shaun; Camacho, Alfredo; Fayek, Mostafa; Epp, Mark; Spell, Terry L.; Armstrong, Richard

2018-01-01

The Red Lake greenstone belt is situated in northwestern Ontario within the Uchi Subprovince, Superior Province. Most gold deposits therein are associated with major deformation corridors; the east-west oriented "Mine trend" hosts most of the large deposits and the northeast-southwest "East Bay trend" hosts several small deposits and showings. Gold along the East Bay trend typically occurs in quartz replacement veins that were emplaced into pre-existing quartz-carbonate veins. Gold can occur as free gold or along vein margins associated with pyrite and pyrrhotite. Most primary fluid inclusions, preserved in relatively undeformed portions of veins, are carbonaceous with lesser quantities of aqueous inclusions. The average homogenization temperature of aqueous fluids is 250 °C; however, the abundance of three-phase inclusions, variation in liquid-vapor ratios, and a wide range in homogenization temperatures indicate that immiscibility, effervescence, and fluid mixing are mechanisms associated with gold deposition. The age ( 2550 Ma) of alteration minerals in the Abino area is considerably younger (by 100 Myr) than alteration minerals in other deposits in the Red Lake district, indicating that the mineralizing fluid history was more protracted than previously thought. Along the East Bay trend, barren veins generally have lower δ18OVSMOW values (0.0 to 8.5‰) relative to auriferous veins (9.6 and 13.1‰). Consequently, the oxygen isotopic composition of quartz could be used as a vector for gold mineralization. The genetic model for the East Bay trend involves several stages of vein formation. Auriferous veins formed near the upper boundary of the mesozonal regime (depth of 5-6 km).

Mineralogy of Copper-Gold Deposit, Masjid Daghi Area, Jolfa, IRAN

Science.gov (United States)

Zenoozi, Roya

2010-05-01

The Copper-Gold deposit of Masjid Daghi area is located in the Jolfa quadrangle (scale 1:100,000), East Azerbaijan Province, north-west Iran. The deposit, hosting by sub-volcanic bodies comprise of quartz monzonite composition whose intruded the Tertiary volcanic and volcanic-sedimentary rocks and turbidities. The Tertiary volcanic rocks consist of andesite, trachy andesite and quartz andesite. These mineral-bearing bodies related to Late Eocene sub-volcanic activities which intrudded the Eocene volcanic rocks. Mineralography, XRD and SEM studies showed that the variations in mineralization of the area. The main agent of mineralization is the intrusion of Late Eocene sub volcanic bodies inside the Tertiary volcanic units. The mineralography studies revealed two main groups of mineralization as oxides and sulfides. The sulfide minerals formed as veins, vein lets and stock work.The economic minerals comprise of native gold, copper sulfides. The native gold occurring in siliceous veins and almost as inclusions inside the sulfides minerals such as chalcopyrite. The copper sulfides, contain pyrite, chalcopyrite and chalco-pyrrhoyite. Pyrite is main sulfide in the area and formed as disseminations, cavity filling and colloform. The amount of pyrite, chalcopyrite and chalco-pyrrhoyite increases with depth. Supergene alteration produced digenite, covellite, bornite, and malachite. The alteration occurred as potassic, phyllic, argillic and propylitic minerals. Furthermore, selective sercitic, sericitic-chloritic and alunitic alterations are seen around the mineralized veins. The mineralography studies indicate that pyrite is main mineral phase and native gold occurred in silicious vein almost as inclusions inside the sulfide mineral. Most of economic mineral formed as veins, vein lets, disseminated, cavity filling and colloform which related to intrusions of Late Eocene quartz monzonite bodies into the Eocene volcanic rocks and turbiditse. Some types of alterations such as

Transcutaneous laser treatment of leg veins

NARCIS (Netherlands)

Meesters, Arne A.; Pitassi, Luiza H. U.; Campos, Valeria; Wolkerstorfer, Albert; Dierickx, Christine C.

2014-01-01

Leg telangiectasias and reticular veins are a common complaint affecting more than 80% of the population to some extent. To date, the gold standard remains sclerotherapy for most patients. However, there may be some specific situations, where sclerotherapy is contraindicated such as needle phobia,

Tectonic setting of synorogenic gold deposits of the Pacific Rim

Science.gov (United States)

Goldfarb, R.J.; Phillips, G.N.; Nokleberg, W.J.

1998-01-01

More than 420 million oz of gold were concentrated in circum-Pacific synorogenic quartz loades mainly during two periods of continental growth, one along the Gondwanan margin in the Palaeozoic and the other in the northern Pacific basin between 170 and 50 Ma. These ores have many features in common and can be grouped into a single type of lode gold deposit widespread throughout clastic sedimentary-rock dominant terranes. The auriferous veins contain only a few percent sulphide minerals, have gold:silver ratios typically greater than 1:1, show a distinct association with medium grade metamorphic rocks, and may be associated with large-scale fault zone. Ore fluids are consistently of low salinity and are CO2-rich. In the early and middle Palaeozoic in the southern Pacific basin, a single immense turbidite sequence was added to the eastern margin of Gondwanaland. Deformation of these rocks in southeastern Australia was accompanied by deposition of at least 80 million oz of gold in the Victorian sector of the Lachlan fold belt mainly during the Middle and Late Devonian. Lesser Devonian gold accumulations characterized the more northerly parts of the Gondwanan margin within the Hodgkinson-Broken River and Thomson fold belts. Additional lodes were emplaced in this flyschoid sequence in Devonian or earlier Palaeozoic times in what is now the Buller Terrane, Westland, New Zealand. Minor post-Devonian growth of Gondwanaland included terrane collision and formation of gold-bearing veins in the Permian in Australia's New England fold belt and in the Jurassic-Early Cretaceous in New Zealand's Otago schists. Collision and accretion of dozens of terranes for a 100-m.y.-long period against the western margin of North America and eastern margin of Eurasia led to widespread, lattest Jurassic to Eocene gold veining in the northern Pacific basin. In the former location, Late Jurassic and Early Cretaceous veins and related placer deposits along the western margin of the Sierra Nevada

Natural and mining-related mercury in an orogenic greywacke terrane, South Island, New Zealand

International Nuclear Information System (INIS)

Holley, E.A.; Craw, D.; Kim, J.P.

2010-01-01

Mercury (Hg) is naturally present in warm springs and mesothermal (orogenic) gold-bearing quartz vein systems in the South Island of New Zealand. Mercury amalgamation was used historically in ore processing at gold (Au) mines, resulting in composite natural and anthropogenic Hg signatures at these sites. This study compares natural Hg enrichment of the Au vein systems, residual anthropogenic Hg added for amalgamation, and enrichment of naturally present Hg during ore processing. Mercury concentration data are presented for solids and water at historic mine sites, the modern Macraes mine, fault-related warm springs, and zones of naturally occurring cinnabar and Hg-bearing Au. Arsenic (As) concentrations are also presented, as As is the most environmentally significant element in this tectonic setting. Tailings and processing residues at historic mine sites (Blackwater mine, West Coast; Golden Point and Golden Bar, Hyde-Macraes shear zone) contain up to 1000 mg/kg Hg, and in adjacent surface waters Hg is at or slightly above background from 0.6 to 0.8 ng/L. Relative to South Island Hg, As is more environmentally significant: solid wastes at some historic mine and mineral processing sites contain up to 30.5 wt% As due to enrichment of natural As in mineralised rocks. Shallow groundwater and processing waters at the modern Macraes mine are up to 0.01 mg/L Hg due to natural Hg in mineralised rocks, and no significant Hg elevation is evident in nearby surface waters, which are 3 to 10 4 times higher than primary ore, and Hg is disproportionally increased relative to As, indicating that much of the Hg was added during the amalgamation process. Natural cinnabar deposition from warm springs results in localised, strongly elevated Hg, equal to or less than the Hg contents in historic mine processing residues. Warm spring precipitates are up to 111 mg/kg Hg and waters are 0.3 μg/L Hg, comparable to data reported for active North Island geothermal (epithermal-style) systems

The Metamorphic Rocks-Hosted Gold Mineralization At Rumbia Mountains Prospect Area In The Southeastern Arm of Sulawesi Island, Indonesia

Directory of Open Access Journals (Sweden)

Hasria Hasria

2017-09-01

Full Text Available Recently, in Indonesia gold exploration activities  are not only focused along volcanic-magmatic belts, but also starting to shift along metamorphic and sedimentary terrains. The study area is located in Rumbia mountains, Bombana Regency, Southeast Sulawesi Province. This paper is aimed to describe characteristics of alteration and ore mineralization associated  with metamorphic rock-related gold deposits.  The study area is found the placer and  primary gold hosted by metamorphic rocks. The gold is evidently derived from gold-bearing quartz veins hosted by Pompangeo Metamorphic Complex (PMC. These quartz veins are currently recognized in metamorphic rocks at Rumbia Mountains. The quartz veins are mostly sheared/deformed, brecciated, irregular vein, segmented and  relatively massive and crystalline texture with thickness from 1 cm to 15.7 cm. The wallrock are generally weakly altered. Hydrothermal alteration types include sericitization, argillic, inner propylitic, propylitic, carbonization and carbonatization. There some precious metal identified consist of native gold and ore mineralization including pyrite (FeS2, chalcopyrite (CuFeS2, hematite (Fe2O3, cinnabar (HgS, stibnite (Sb2S3 and goethite (FeHO2. The veins contain erratic gold in various grades from below detection limit <0.0002 ppm to 18.4 ppm. Based on those characteristics, it obviously indicates that the primary gold deposit present in the study area is of orogenic gold deposit type. The orogenic gold deposit is one of the new targets for exploration in Indonesia

Geology and geochemistry of epithermal precious metal vein systems in the intra-oceanic arcs of Palau and Yap, western Pacific

Science.gov (United States)

Rytuba, J.J.; Miller, W.R.

1990-01-01

The Palau and Yap arcs are part of an intra-oceanic island-arc-trench system which separates the Pacific and Philippine plates in the western Pacific Ocean. The 350-km-long Palau arc consists of over 200 islands while the 400-km-long Yap arc located to the north has only four major islands exposed. Four of the largest islands in Palau are composed primarily of early Eocene to mid-Miocene volcanic rocks and the four islands comprising Yap contain only Miocene volcanic rocks. Basalt and basaltic andesites of the Babelthuap Formation are the oldest volcanic rocks in Palau and are characterized by high MgO, Ni and Cr and low TiO2 and have a boninitic affinity. They form the central and southeastern parts of Babelthuap Island. Oligocene arc tholeiite flows having an age of 34-35.5 Ma comprise most of the three smaller volcanic islands in Palau and the western part of Babelthuap. The youngest volcanic rocks are dacitic intrusions having an age of 22.7-23.2 Ma. The Yap arc is unusual in that metamorphic rocks up to amphibolite grade form most of the islands. These are underlain by a melange composed of igneous and volcanic clasts as well as clasts from a dismembered copper-gold skarn deposit. Miocene volcanic rocks consisting of flows and volcaniclastic deposits overlie the melange and metamorphic complex. An epithermal precious-metal vein system hosted by flows and flow breccias of the Babelthuap Formation occurs in an area 1.5 km by 1 km on the southeast side of Babelthuap Island. Over 50 veins and mineralized breccias ranging up to 2 m in width and having a strike length up to 500 m contain from trace to 13.0 ppm gold. The veins consist of quartz with varying amounts of sulfides and iron oxides after sulfides and the mineralized breccias consist of brecciated country rock cemented by quartz and iron oxides after sulfides. The veins and mineralized breccias generally dip within 15?? of vertical and have two preferred orientations, north-northwest and north

Late-Hercynian intrusion-related gold deposits: An integrated model on the Tighza polymetallic district, central Morocco

Science.gov (United States)

Éric, Marcoux; Khadija, Nerci; Yannick, Branquet; Claire, Ramboz; Gilles, Ruffet; Jean-Jacques, Peucat; Ross, Stevenson; Michel, Jébrak

2015-07-01

Gold have been recently recognized in the Tighza (formerly Jebel Aouam) district, in the Hercynian belt of central Morocco. This district has long been known for its W mineralization, as well as major Pb-Ag-Zn, and minor Sb-Ba deposits, all geographically associated with late-Hercynian calc-alkaline magmatism. Gold mineralization in the district is mainly hosted by thick W-Au quartz veins located around the "Mine granite" small granitic plug. Within the veins, gold grade is highest (up to 70 g/t) close to the granite but rapidly decreases going outward from the granite, defining a perigranitic zoning. Anomalous gold grades have also been measured in hydrothermal skarn layers close to two other granitic plugs (Kaolin granite and Mispickel granite), associated with disseminated As-Fe sulfides. The paragenetic sequence for the W-Au quartz veins shows three stages: (1) an early oxidized stage with wolframite-scheelite associated with early quartz (Q1), (2) an intermediate Bi-As-Te-Mo-Au sulfide stage with loellingite, bismuth minerals and native gold with a later quartz (Q2), restricted to a narrow distance from the granite, and (3) a late lower temperature As-Cu-Zn-(Pb) stage with abundant massive pyrrhotite, arsenopyrite and sphalerite, locally forming independent veins ("pyrrhotite vein"). Both Q1 hyaline and Q2 saccharoidal gold-bearing quartz display aqua-carbonic fluids with minor H2S and Cu and an homogeneous composition (81 mole% H2O, 18 mole% CO2 and about 1 mole% NaCl). The trapping pressure is estimated to 1.5-2 kbar with temperature ranging from 300 to 350 °C. Q1 inclusions have exploded indicating an uplift of the Tighza block, that lead to saccharoidal Q2 quartz deposition with multiphase NaCl-saturated fluid inclusions. 40Ar/39Ar dating demonstrates that the "Mine granite", tungsten skarnoid, scheelite-molybdenite veins, and very likely gold-bearing veins are coeval, emplaced at 286 ± 1 Ma. Multiple and widespread metal sources are indicated by

Gold mineralisation near the Main Divide, upper Wilberforce valley, Southern Alps, New Zealand

International Nuclear Information System (INIS)

Becker, J.A.; Craw, D.; Horton, T.; Chamberlain, C.P.

2000-01-01

Veins up to 8 m wide fill extensional fractures in Torlesse Terrane metasediments near the Main Divide in the upper Wilberforce valley, Canterbury, New Zealand. The upper Wilberforce veins are part of a prominent 40 km long, NNE-trending swarm of gold-bearing veins formed across the Main Divide during the Late Cenozoic rise of the Southern Alps. The veins occur within, and near, a prominent set of faults which constitute the Main Divide Fault Zone. The veins are irregular in shape due to contrasting host rock properties, and have been only weakly sheared and deformed. Veins cut across greywacke beds and follow irregularly along argillite beds, on the 1-10 m scale. Quartz dominates vein mineralogy, but albite forms up to 45% of some veins, and minor chlorite, pyrite, arsenopyrite, chalcopyrite, and gold occur sporadically, especially in breccias near vein margins. Fluid inclusions in vein quartz homogenise at 180-253 degrees C, and arsenopyrite composition (28.3-30.8 at.% As) suggest formation temperatures of 250-350 degrees C. Elevated arsenic levels (up to 200 ppm above a background of 10 ppm) in some host greywackes and argellites suggest that hydrothermal activity pervaded host rocks as well as forming veins, but there is no textural evidence for this fluid flow. Late-stage carbonates in faults adjacent to the quartz veins, but which postdate the quartz veins, have δ 18 O ranging from 11.1 to 25.6 per thousand, and δ 13 C ranging from -12.5 to -1.1 per thousand. These carbonates were deposited by a mixture of meteoric and crustally isotopically exchanged fluid as a shallow-level manifestation of the same hydrothermal system which deposited the quartz veins. The upper Wilberforce veins structurally and mineralogically resemble some Late Cenozoic gold-bearing vein systems in the Mt Cook area, 100 km to the southwest along the Southern Alps. (author). 52 refs., 9 figs., 3 tabs

Alteration zones: are they a good target for gold deposits in Egypt

International Nuclear Information System (INIS)

Botros, N.S.

2002-01-01

Extensive rock alterations are a clearly visible characteristic of most Egyptian gold deposits and occurrences. The alterations occur either surrounding the auriferous quartz veins and/or structurally controlled by specific structural features, such as fractures and shear surfaces. Some samples of these alteration zones have proved to be anomalously enriched in gold while others are completely barren. Accordingly there is a controversy on the merit of alteration zones as good lead to gold. Here, the various types of wall rocks wall-rock alteration are reviewed with a discussion on the possible reaction that could have generated them. It is concluded that two main styles of alterations could be recognized in the field. The first results during the liberation of gold from the source rocks, and is characterized by being widely distributed and spatial relation to major structures. The second style, however, is related to the deposition of gold and is recognizable only within a few meters of the auriferous quartz veins. The potentiality of each style is discussed and applications of concept are offered. In general, alterations accompanying the liberation of gold are not completely devoid of gold, but may still retain some gold depending on the mineralogical siting of gold in the source rocks. Moreover, this type of alteration is a good criterion for the presence of gold in the nearby sites. Alterations accompanying deposition of gold, on the other hand, constitute a good target for gold particularly the portions that are dissected by minor quartz veins, veinlets and stockworks (silicification) where gold is believed to migrate to such sites with silica liberated during the different types of alterations. The presence of some efficient precipitants, such as sulphides, carbonates, clay minerals, sericites, iron oxides, chlorite and graphite in the alteration zones is a good indicator of the alteration zone. (author)

Application of U-Th-Pb phosphate geochronology to young orogenic gold deposits: New age constraints on the formation of the Grass Valley gold district, Sierra Foothills province, California

Science.gov (United States)

Taylor, Ryan D.; Goldfarb, Richard J.; Monecke, Thomas; Fletcher, Ian R.; Cosca, Michael A.; Kelly, Nigel M.

2015-01-01

The Grass Valley orogenic gold district in the Sierra Nevada foothills province, central California, the largest historic gold producer of the North American Cordillera, comprises both steeply dipping east-west (E-W) veins located along lithologic contacts in accreted ca. 300 and 200 Ma oceanic rocks and shallowly dipping north-south (N-S) veins hosted by the Grass Valley granodiorite; the latter have yielded about 70 percent of the 13 million ounces of historic lode gold production in the district. The oceanic host rocks were accreted to the western margin of North America between 200 and 170 Ma, metamorphosed to greenschist and amphibolite facies, and uplifted between 175 and 160 Ma. Large-scale magmatism in the Sierra Nevada occurred between 170-140 Ma and 120-80 Ma, with the Grass Valley granodiorite being emplaced during the older episode of magmatism. Uranium-lead isotopic dating of hydrothermal xenotime yielded the first absolute age of 162±5 Ma for the economically more significant N-S veins. The vein-hosted xenotime, as well as associated monazite, are unequivocally of hydrothermal origin as indicated by textural and chemical characteristics, including grain shape, lack of truncated growth banding, lack of a Eu anomaly, and low U and Th concentrations. Furthermore, the crack-seal texture of the veins, with abundant wallrock slivers, suggests their formation as a result of episodic fluid flow possibly related to reoccurring seismic events, rather than a period of fluid exsolution from an evolving magma. The N-S veins are temporally distinct from a younger 153-151 Ma gold event that was previously reported for the E-W veins. Overlapping U-Pb zircon (159.9±2.2 Ma) and 40Ar/39Ar biotite and hornblende (159.7±0.6 to 161.9±1.4 Ma) ages and geothermobarometric calculations indicate that the Grass Valley granodiorite was emplaced at ca. 160 Ma at elevated temperatures (~800°C) within approximately 3 km of the paleosurface and rapidly cooled to the ambient

Some Observations on Gold in the Weathering Profile at Garimpo Porquinho, an Artisanal Mine in the Tapajós Region, Brazilian Amazon

OpenAIRE

Sonia Maria Barros de Oliveira; João Henrique Larizzatti

2006-01-01

At Garimpo Porquinho (Tapajós Province, Brazilian Amazon) gold-bearing quartz veins containing sulfides occur in anarrow zone affected by hydrothermal alteration. The artisanally mined veins are exposed in a saprolite zone extending downat least 9 m to the fresh rock and are covered by a 1 m thick residual soil. Lateral gold dispersion in the saprolite is notnoticeable whereas in the soil gold dispersion has been observed as far as 2 m from the vein. Trace metals associated with goldinclude A...

Determination of thorium in native gold by radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Liu, Y.; Kraehenbuehl, U.

1995-01-01

Thorium concentrations in 11 native gold samples from different sources, e.g. placer gold, vein and lode gold were determined. Thorium was determined by radiochemical separation and measurement of protactinium from irradiated native gold samples. The chemical yield of the separation procedures is 90%. Other elements were measured by gamma-ray spectroscopy. The radiochemical separation procedures described in this work make accurate determination of Th concentrations in native gold at picogram concentrations possible. (orig.)

A review of the anatomy and clinical significance of adrenal veins.

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Cesmebasi, Alper; Du Plessis, Maira; Iannatuono, Mark; Shah, Sameer; Tubbs, R Shane; Loukas, Marios

2014-11-01

The adrenal veins may present with a multitude of anatomical variants, which surgeons must be aware of when performing adrenalectomies. The adrenal veins originate during the formation of the prerenal inferior vena cava (IVC) and are remnants of the caudal portion of the subcardinal veins, cranial to the subcardinal sinus in the embryo. The many communications between the posterior cardinal, supracardinal, and subcardinal veins of the primordial venous system provide an explanation for the variable anatomy. Most commonly, one central vein drains each adrenal gland. The long left adrenal vein joins the inferior phrenic vein and drains into the left renal vein, while the short right adrenal vein drains immediately into the IVC. Multiple variations exist bilaterally and may pose the risk of surgical complications. Due to the potential for collaterals and accessory adrenal vessels, great caution must be taken during an adrenalectomy. Adrenal venous sampling, the gold standard in diagnosing primary hyperaldosteronism, also requires the clinician to have a thorough knowledge of the adrenal vein anatomy to avoid iatrogenic injury. The adrenal vein acts as an important conduit in portosystemic shunts, thus the nature of the anatomy and hypercoagulable states pose the risk of thrombosis. © 2014 Wiley Periodicals, Inc.

Some Key Features and Possible Origin of the Metamorphic Rock-Hosted Gold Mineralization in Buru Island, Indonesia

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Arifudin Idrus

2014-07-01

Full Text Available DOI: 10.17014/ijog.v1i1.172This paper discusses characteristics of some key features of the primary Buru gold deposit as a tool for a better understanding of the deposit genesis. Currently, about 105,000 artisanal and small-scale gold miners (ASGM are operating in two main localities, i.e. Gogorea and Gunung Botak by digging pits/shafts following gold-bearing quartz vein orientation. The gold extraction uses mercury (amalgamation and cyanide processing. The field study identifies two types/generations of quartz veins namely (1 Early quartz veins which are segmented, sigmoidal, dis­continous, and parallel to the foliation of host rock. The quartz vein is lack of sulfides, weak mineralized, crystalline, relatively clear, and maybe poor in gold, and (2 Quartz veins occurred within a ‘mineralized zone’ of about 100 m in width and ~1,000 m in length. The gold mineralization is strongly overprinted by an argillic alteration zone. The mineralization-alteration zone is probably parallel to the mica schist foliation and strongly controlled by N-S or NE-SW-trending structures. The gold-bearing quartz veins are characterized by banded texture particularly colloform following host rock foliation and sulphide banding, brecciated, and rare bladed-like texture. The alteration types consist of propylitic (chlorite, calcite, sericite, argillic, and carbonation represented by graphite banding and carbon flakes. The ore mineralization is characterized by pyrite, native gold, pyrrhotite, and arsenopyrite. Cinnabar, stibnite, chalcopyrite, galena, and sphalerite are rare or maybe absent. In general, sulphide minerals are rare (<3%. Fifteen rock samples were collected in Wamsaid area for geochemical assaying for Au, Ag, As, Sb, Hg, Cu, Pb, and Zn. Eleven of fifteen samples yielded more than 1.00 g/t Au, in which six of them are in excess of 3.00 g/t Au. It can be noted that all high-grade samples are originally or containing limonitic materials, that suggest

Relantionships between gold mineralization and granite - Discussion with the support of a pluridisciplinary study of the Passa Tres gold deposit (South Brazil)

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Dressel, Bárbara; Chauvet, Alain; Trzaskos, Barbara; Biondi, Joao Carlos; Bruguier, Olivier; Monie, Patrick; Villanova, Sandro; Bazille, Jose

2016-04-01

The Passa Três Granite, located at East of the Paraná State is elongated following a NNE-SSW direction. This sienogranite is emplaced within metapelites of the meso to neoproterozoic Açungui Group, between the Morro Agudo and Lancinha transcurrent faults, comprising the N040°E trending Lancinha Transcurrent Fault System. Gold mineralization within the Passa Três Granite is constituted by huge quartz veins with sulfides, variable quantities of fluorite and carbonates, forming orebodies with different internal textures, including massive, banded, sheared and brecciated. Structural data indicate the existence of two major fault systems, one N-S and the other E-W, with dips of 15-45°W and 20-75°S, respectively. Both NS and EW systems are interpreted to be contemporaneous and conjugate. Normal motions are everywhere suspected and main mineralized veins are located at opening sites at these fault systems, such as pull-aparts. The structural model suggests that the normal motion can be initiated by shearing along a "guide" level, in which sulfides and clay minerals are concentrated. This configuration can be observed at several scales, such as field, hand samples and thin section. Mineralized veins mainly contain, in addition to the quartz of the gangue, sulphides (pyrite, chalcopyrite, galena, molybdenite), fluorite, chlorite, muscovite, sericite, and carbonate. The presence of sericite, kaolinite and chlorite indicate the occurrence of, at least, propylitic and phyllic-type alterations, both in core of the granite and best-expressed at the rim of quartz-rich orebodies. Gold occurs as native grains in core of the quartz veins, within fractures that affect pyrite and frequently exhibiting normal motions consistent with the one observed at larger scale and systematically associated with chalcopyrite and galena. Quartz veins are sometimes bordered by aplitic dike. Additionally, some of the veins can exhibit a very thin margin of adularia minerals that seems to

Geology of epithermal silver-gold bulk-mining targets, bodie district, Mono County, California

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Hollister, V.F.; Silberman, M.L.

1995-01-01

The Bodie mining district in Mono County, California, is zoned with a core polymetallic-quartz vein system and silver- and gold-bearing quartz-adularia veins north and south of the core. The veins formed as a result of repeated normal faulting during doming shortly after extrusion of felsic flows and tuffs, and the magmatic-hydrothermal event seems to span at least 2 Ma. Epithermal mineralization accompanied repeated movement of the normal faults, resulting in vein development in the planes of the faults. The veins occur in a very large area of argillic alteration. Individual mineralized structures commonly formed new fracture planes during separate fault movements, with resulting broad zones of veinlets growing in the walls of the major vein-faults. The veinlet swarms have been found to constitute a target estimated at 75,000,000 tons, averaging 0.037 ounce gold per ton. The target is amenable to bulkmining exploitation. The epithermal mineralogy is simple, with electrum being the most important precious metal mineral. The host veins are typical low-sulfide banded epithermal quartz and adularia structures that filled voids created by the faulting. Historical data show that beneficiation of the simple vein mineralogy is very efficient. ?? 1995 Oxford University Press.

Geochemistry of Gold Deposits in Anka Schist Belt, Northwestern ...

African Journals Online (AJOL)

HP USER

ABSTRACT. Gold quartz veins have been identified associated with the rock formations of the Anka Schist Belt forming eight gold deposits that include Kuba I, Kuba II, Doka, Dumi I, Dumi II, Zurzurfa I, Zurzurfa II, Jameson and Kwali. The present study involves the use of major and trace elements to characterize some of the.

Gold placer and Quaternary stratigraphy of the Jabal Mokhyat area, southern Najd Province, Kingdom of Saudi Arabia

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Schmidt, D.L.; Puffett, W.P.; Campbell, W.L.; Al-Koulak, Z. H.

1981-01-01

An ancient gold placer at Jabal Mokhyat (lat 20?12.2'N., long 43?28'E.), about 90 km east of Qalat Bishah in the southern Najd Province, Kingdom of Saudi Arabia, was studied in 1973. Seven hundred and twenty-eight samples in 25 measured sections were collected along trenches and pits 2.5 m in depth and 2,600 m in total length. Alluvium was thicker than the excavation depth along about 50 percent of the trench length. The average gold content was 4.4 mg per m3, and the highest grade trench contained 40 mg gold per m 3. Because fine particulate gold is rare in the alluvium, a few large particles, 1 to 5 mm in diameter, greatly affected the sampling results. The ancient placer diggings are in small headwater wadis distributed over a 30-km 2 area, and the total dug area is about 1.2 km2. The placer produced an estimated 50 kg of gold and was worked about 2,600 + 250 years ago. The potential for a present-day placer operation is small. The gold is sparsely distributed in locally derived, flood-deposited, immature gravels throughout a stratigraphic section that consists of 1) calichified, saprolitic bedrock of Precambrian age; 2) basal, intensely calichified, saprolitic gravel (0-3 m thick) of Pleistocene age; 3) disconformable, slightly consolidated gravel and sand (0-1 m thick) of late Pleistocene age containing sparse, disseminated caliche; 4) firm loessic silt (0-1 m thick) of early Holocene age; and 5) loose sand and gravel (0.3-1 m thick) of late Holocene age. The loessic silt accumulated during the Holocene pluvial. The top of the loessic silt unit is dated at about 6,000 years B.P. by using charcoal from hearths of ancient man. Following the Holocene pluvial, the climate became arid, and extreme desiccation resulted in abundant eolian sand that progressively diluted the late Holocene gravels. The remnants of the pre-Holocene stratigraphy suggest similar climatic cycles during the Pleistocene. Abundant, sparsely mineralized, gold-bearing quartz veins (0-1 m wide

Structure, alteration, and geochemistry of the Charlotte quartz vein stockwork, Mt Charlotte gold mine, Kalgoorlie, Australia: time constraints, down-plunge zonation, and fluid source

Science.gov (United States)

Mueller, Andreas G.

2015-02-01

The Kalgoorlie district in the Archean Yilgarn Craton, Western Australia, comprises two world-class gold deposits: Mt Charlotte (144 t Au produced to 2013) in the northwest and the Golden Mile (1,670 t Au) in the southeast. Both occur in a folded greenschist-facies gabbro sill adjacent to the Golden Mile Fault (D2) in propylitic alteration associated with porphyry dikes. At Mt Charlotte, a shear array of fault-fill veins within the Golden Mile Fault indicates sinistral strike-slip during Golden Mile-type pyrite-telluride mineralization. The pipe-shaped Charlotte quartz vein stockwork, mined in bulk more than 1 km down plunge, is separated in time by barren D3 thrusts from Golden Mile mineralization and alteration, and occurs between two dextral strike-slip faults (D4). Movement on these faults generated an organized network of extension and shear fractures opened during the subsequent infiltration of high-pressure H2S-rich fluid at 2,655 ± 13 Ma (U-Pb xenotime). Gold was deposited during wall rock sulphidation in overlapping vein selvages zoned from deep albite-pyrrhotite (3 g/t Au) to upper muscovite-pyrite assemblages (5 g/t Au bulk grade). Chlorite and fluid inclusion thermometry indicate that this kilometre-scale zonation is due to fluid cooling from 410-440 °C at the base to 350-360 °C at the top of the orebody, while the greenstone terrane remained at 250 °C ambient temperature and at 300 MPa lithostatic pressure. The opened fractures filled with barren quartz and scheelite during the retrograde stage (300 °C) of the hydrothermal event. During fracture sealing, fluid flux was periodically restricted at the lower D3 thrust. Cycles of high and low up-flow, represented by juvenile H2O-CO2 and evolved H2O-CO2-CH4 fluid, respectively, are recorded by the REE and Sr isotope compositions of scheelite oscillatory zones. The temperature gradient measured in the vein stockwork points to a hot (>600 °C) fluid source 2-4 km below the mine workings, and several

First evidence of epithermal gold occurrences in the SE Afar Rift, Republic of Djibouti

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Moussa, N.; Fouquet, Y.; Le Gall, B.; Caminiti, A. M.; Rolet, J.; Bohn, M.; Etoubleau, J.; Delacourt, C.; Jalludin, M.

2012-06-01

The geology of the Republic of Djibouti, in the SE Afar Triangle, is characterized by intense tectonic and bimodal volcanic activity that began as early as 25-30 Ma. Each magmatic event was accompanied by hydrothermal activity. Mineralization generally occurs as gold-silver bearing chalcedony veins and is associated with felsic volcanism. Eighty samples from mineralized hydrothermal chalcedony, quartz ± carbonate veins and breccias were studied from ten sites representing four major volcanic events that range in age from early Miocene to the present. The most recent veins are controlled by fractures at the edges of grabens established during the last 4 Myr. Gold in excess of 200 ppb is present in 30% of the samples, with values up to 16 ppm. Mineralogical compositions allowed us to identify different types of mineralization corresponding to different depths in the hydrothermal system: (1) surface and subsurface mineralization characterized by carbonate chimneys, gypsum, silica cap and quartz ± carbonate veins that are depleted in metals and Au; (2) shallow banded chalcedony ± adularia veins related to boiling that contain up to 16 ppm Au, occurring as native gold and electrum with pyrite, and tetradymite; (3) quartz veins with sulfides, and (4) epidote alteration in the deepest hydrothermal zones. Samples in which pyrite is enriched in As tend to have a high Au content. The association with bimodal volcanism, the occurrence of adularia and the native Au and electrum in banded chalcedony veins are typical of epithermal systems and confirm that this type of mineralization can occur in a young intracontinental rift system.

Geochemistry of Gold Deposits in Anka Schist Belt, Northwestern ...

African Journals Online (AJOL)

Gold quartz veins have been identified associated with the rock formations of the Anka Schist Belt forming eight gold deposits that include Kuba I, Kuba II, Doka, Dumi I, Dumi II, Zurzurfa I, Zurzurfa II, Jameson and Kwali. The present study involves the use of major and trace elements to characterize some of the features that ...

Noble Gases in Alpine Gold: U/Th-He Dating and Excesses of Radiogenic He and AR

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Eugster, O.; Hofmann, B.; Krahenbuhl, U.; Neuenschwander, J.

1992-07-01

Gold precipitates in hydrothermal fluids along with other heavy elements, such as Ag and Pt. In order to explore the possibility of dating the formation of gold we determined the concentrations of U, Th, and their decay product ^4He, as well as the K and ^40Ar concentrations in vein-type gold and in placer gold samples. The gold-quartz veins at Brusson in the south-western alps were formed approximately 32 Ma ago during an episode of tectonic uplift (Diamond, 1990). Alpine material was deposited as sediment layers in the region of central Switzerland and placer gold is thus relatively abundant in the rivers of the Napf area. We washed placer gold from the river Grosse Fontanne in 1990 and 1991. Placer gold that had been collected from the river Kruempelgraben in 1933 and a sample of vein-type free gold grown on quartz rock from the Brusson area (Val d'Ayas) have been obtained from the Museum of Natural History in Bern. Table 1 gives the results. Most of the ^4He is released above 1050 degrees C, that is when gold melts, indicating that gold is extremely well retentive for He. From the ^4He concentration of (269 +- 20) x 10^-8 cm^3 STP/g, (0.4 +- 0.1) ppm U, and (0.9 +- 0.3) ppm Th for vein-type gold we calculate a U/Th-He age of (36 +- 8)Ma. This age agrees within errors with the proposed age of 32 Ma. The data given in Table 1 show that all placer gold samples contain excesses of radiogenic ^4He and ^40Ar relative to the concentrations expected from the U/Th and K decay, respectively, if we assume a formation age of 32 Ma. The quartz sample is depleted in ^4He but strongly enriched in radiogenic ^40Ar. The excess of ^40Ar(sub)rad is easier to explain than that of ^4He. Vein-type gold and placer gold contain quartz inclusions (Schmid, 1973). The high ^40Ar(sub)rad content of quartz (Table 1) indicates that the ^40Ar(sub)rad excess of gold originates from quartz inclusions. Excess ^4He in gold must be of radiogenic origin. Taking ^20Ne and ^36Ar as a measure for the

Gold deposits in the western sector of the Central Spanish System

International Nuclear Information System (INIS)

Barrios, S.; Florido, P.; Reguilon, R.

2010-01-01

The gold deposits in the western sector of the Central Spanish System can be grouped in: (1) gold quartz veins type (El Chivote, La Pedrera), (2) paleoplacers: gold nuggets in tertiary alluvial deposits (Las Cavenes, Sierro de Coria), (3) quaternary placers (Rio Erjas), (4) gold nuggets in a regolith developed on the Schist and Graywacke Complex (CEG) (Casillas de Coria). The morphological study of gold nuggets will provide physical, chemical, bacteriological and climatic characteristics. Mining works are located on these deposits from roman time to the present day. (Author)

Geostatistical Approach to Estimating the Gold Ore Characteristics and Gold Reserves: A Case Study Daksa Area, Quang Nam Province, Viet Nam

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Luan Truong, Xuan; Luong Le, Van; Quang Truong, Xuan

2015-04-01

Daksa gold deposit is the biggest gold deposits in Vietnam. The Daksa geological structure complicated, distributed mainly metamorphosed sedimentary NuiVu formation (PR3-?1nv2). The sulfide gold ore bodies distributed in quartz schist, quartz - biotite related to faut and distribution wing anticline. The gold ore bodies form circuits, network circuits, circuits lenses; fill the cup surface layer of the developing northeast - southwest; is the less than or west longitude north - SE. The results show that, Au and accompanying elements (Ag, Pb and Zn) have correlated pretty closely. All of its consistent with the logarithmic distribution standard, in accordance with the law of distribution of content mineral rare. The structure functions have nugget effect and spherical models with show that Au and accompanying elements special variation are changes. Au contents shown local anisotropy, no clearly anisotropy (K=1,17) and weakly anisotropy (K=1,4). Intensity mineralization of the ore bodies are quite high with demand spherical conversion coefficient ranging from 0.49 to 0.75 and from 0.66 to 0.97 (for other body). With nugget effects, ore bodies shown that it is consistent with mineralization in the ore bodies study, ore erasable, micro vein, infilling fractures in quartz vein. All of variogram presents local anisotropy, indicated gold mineralization at study area has least two-mineralization stages, consistent with the analysis of mineralography samples. By the results of the structure function study, the authors present the system optimization for exploration deposit and used to evaluate gold reserves by Ordinary Kriging. High accuracy of Kriging estimation results are expressed in the minimum Kriging variance, by compare the results calculated by some other methods (such as distance inverse weighting method, ..) and specially compare to the results of a some blocks have been exploited. Key words: Geostat and gold deposits VN. Daksa and gold mineralization. Geostat

Genetic Affiliation of Gold and Uranium Mineralization in El-Missikat Granite, Central Eastern Desert, Egypt

International Nuclear Information System (INIS)

Ammar, F.A.; Omar, S.A.M.; El Sawey, El.H.

2016-01-01

Gabal El-Missikat granitic pluton is affected by two fault systems trending NW-SE (the oldest) and ENE-WSW directions. It is one of the uranium occurrences in the Eastern Desert of Egypt. The northwestern margins of El-Missikat pluton, along its contact with the gneissose quartz diorite, are dissected by numerous reactivated fractured shear zones running generally ENE-WSW to NE-SW and dipping about 60°-70° to SE. Many white (oldest), smoky or black and jasperoid (youngest) silica veinlets fill the fractures of these shear zones. These veins are of irregular shape and variable thickness ranging from few centimeters to about three meters. They are chiefly affected by silicification, sericitization, hematitization , kaolinization and hydrothermal alterations processes. The smoky black veins are hosting secondary uranium and fluorite-, sulphide-gold mineralizations. Polished surface studies, ICP-ES and Atomic Absorption as well as Scanning Electron Microscope measurements recorded galena, pyrite chalcopyrite, sphalerite and molybdenite in the black and jasperoid mineralized veins. Gold associated with ore mineral assemblage as pyrite, chalcopyrite, sphalerite, galena, sheelite and iron oxides. The identified sulphide minerals not bearing gold are recorded. Gold are relatively coarse-grained, massive and metallic yellow or stretched bronze colored particles. The recorded secondary U minerals associates the sulphide gold-mineralization in the black and jasperoid silica veins. Regarding the mobility of both uranium and gold, U 4+ mobilized in oxidizing medium and migrate and transport as U 6+ , then deposited later as U 4+ when the medium changes to be reducing characterized by high /O 2 . On contrary, gold mobilized when the medium is complex AuCl 3- ion bearing. Consequently, El- Missikat granitic pluton affected by oxidizing Au and Cl 3- bearing high temperature hydrothermal solutions that leached U 4+ , W and Mo from the granitic mass as U 6 + , later decrease of

THE ROLE OF DYNAMOMETAMORPHISM IN THE FORMATION OF THE MUKODEK GOLD FIELD (NORTH PRIBAIKALIE

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V. A. Vanin

2017-01-01

Full Text Available The Mukodek gold field is discussed as an example proving that dynamometamorphism is a major factor in the formation of gold deposits in the Abchad fault zone. This deposit belongs to the gold‐silver‐ore zones of mylonitization and schistosity. The ore source is related to the original host rocks with an increased geochemical background concentration of Au. Due to dynamometamorphism processes, gold particles are abundant and mostly enlarged. From the primary rocks, the dynamometamorphites inherit a positive correlation between the number of particles and the concentrations of gold. The dynamometamorphic complex of the ore field developed in two stages, as a minimum. At the early stage (321.0±1.9 Ma, the host rocks were mechanochemically deformed and transformed into the gold‐ bearing mineralized dynamometamorphites containing sericite, chlorite, ankerite, albite, and quartz. In the second stage (280±15 Ma, the albite‐dolomite‐quartz ore veins were formed. Such veins have industrial gold contents.

Genesis of the hydrothermal gold deposits in the Canan area, Lepaguare District, Honduras

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Mattioli, Michele; Menichetti, Marco; Renzulli, Alberto; Toscani, Lorenzo; Salvioli-Mariani, Emma; Suarez, Pedro; Murroni, Alessandro

2014-04-01

The Canan area (Honduras) is characterized by a gold-bearing ore deposit that is associated with quartz-veined shear zones. Gold mineralization occurs in low-to medium-grade metamorphic host-rocks (graphitic and sericitic schists). Hydrothermal fluids, which are associated with the emplacement of Cretaceous-Tertiary granodioritic intrusions, are responsible for the formation of quartz veins and the hydrothermal alteration of wall-rocks. Three main altered zones have been detected in the wall-rocks as far as 150 cm from the quartz veins. The distal zone (up to 50-cm thick) contains quartz, chlorite and illite. The intermediate zone is the thickest (up to 80 cm) and is marked by quartz, muscovite, sulphides, kaolinite and native elements such as Au and Ag. The proximal zone, which is close to the quartz veins, is rather thin (up to 25 cm) and contains clay minerals, Al-oxides-hydroxides and sulphides. The transition from the distal to the proximal zone is accompanied by the enrichment of SiO2 and the depletion of all other major elements, except for Fe2O3(tot). Precious metals occur in the highest concentrations in the intermediate zone (Au up to 7.6 ppm and Ag up to 11 ppm). We suggest that gold was transported as a reduced sulphur complex and was precipitated from the hydrothermal solution by the reaction of the sulphur complexes with Fe2+ from the alteration of the mafic minerals of the host-rock. Fluid-wall-rock interactions seem to be the main cause of gold mineralization. Genetic relationships with a strike-slip fault system, hydrothermal alteration zones within the metamorphic wall-rocks, and an entire set of geochemical anomalies are consistent with orogenic-type gold deposits of the epizonal class.

Genesis of the Abu Marawat gold deposit, central Eastern Desert of Egypt

Science.gov (United States)

Zoheir, Basem A.; Akawy, Ahmed

2010-06-01

Gold mineralisation at the Abu Marawat mine, central Eastern Desert of Egypt, is related to a system of massive and sheared, milky quartz veins cutting a sequence of Neoproterozoic island arc metavolcanic/volcaniclastic rocks and related banded iron formation (BIF). Sulphide-bearing quartz veins and related hydrothermal breccia bodies display a range of textures including sheared, boudinaged and recrystallised quartz, open space filling and microbreccia. These variable textures imply a complex history of crack-seal mechanism characterising the relation between mineral deposition and a major N-S-trending shear zone, during a late brittle-ductile deformation event which affected the area at about 550 Ma. Gold-base metal mineralisation is associated with brecciation and fracturing of the iron ore bands, close to silicified shears and related quartz veins. The auriferous quartz lodes are characterised by the occurrence of visible pyrite-chalcopyrite ± pyrrhotite ± sphalerite ± galena mineralisation. Gold is refractory in pyrite and chalcopyrite, but rare visible gold/electrum and telluride specks were observed in a few samples. Hydrothermal alteration includes pervasive silicification, pyritisation, sericitisation, carbonatisation confined to a delicate set of veins and altered shears, and a more widespread propylitic alteration assemblage (quartz + chlorite + pyrite + calcite ± epidote). Fluid inclusion petrography and microthermometric studies suggest heterogeneous trapping of a low-salinity (1.4-6.7 wt.% eq. NaCl) aqueous solution and a carbonic fluid. Evidence for fluid immiscibility during ore formation includes variable liquid/vapour ratios in inclusions along individual trails and bulk inclusion homogenisation into liquid and occasionally to vapour at comparable temperatures. The trapping conditions of intragranular aqueous-carbonic inclusions approximate 264-378 °C at 700-1300 bar. Similar temperature estimates have been obtained from Al

Source of boron in the Palokas gold deposit, northern Finland: evidence from boron isotopes and major element composition of tourmaline

Science.gov (United States)

Ranta, Jukka-Pekka; Hanski, Eero; Cook, Nick; Lahaye, Yann

2017-06-01

The recently discovered Palokas gold deposit is part of the larger Rompas-Rajapalot gold-mineralized system located in the Paleoproterozoic Peräpohja Belt, northern Finland. Tourmaline is an important gangue mineral in the Palokas gold mineralization. It occurs as tourmalinite veins and as tourmaline crystals in sulfide-rich metasomatized gold-bearing rocks. In order to understand the origin of tourmaline in the gold-mineralized rocks, we have investigated the major element chemistry and boron isotope composition of tourmaline from three areas: (1) the Palokas gold mineralization, (2) a pegmatitic tourmaline granite, and (3) the evaporitic Petäjäskoski Formation. Based on textural evidence, tourmaline in gold mineralization is divided into two different types. Type 1 is located within the host rock and is cut by rock-forming anthophyllite crystals. Type 2 occurs in late veins and/or breccia zones consisting of approximately 80% tourmaline and 20% sulfides, commonly adjacent to quartz veins. All the studied tourmaline samples belong to the alkali-group tourmaline and can be classified as dravite and schorl. The δ11B values of the three localities lie in the same range, from 0 to -4‰. Tourmaline from the Au mineralization and from the Petäjäskoski Formation has similar compositional trends. Mg is the major substituent for Al; inferred low Fe3+/Fe2+ ratios and Na values (molybdenite related to the tourmaline-sulfide-quartz veins, we propose that the tourmaline-forming process is a result of a single magmatic-hydrothermal event related to the extensive granite magmatism at around 1.79-1.77 Ga. Tourmaline was crystallized throughout the hydrothermal process, which resulted in the paragenetic variation between type 1 and type 2. The close association of tourmaline and gold suggests that the gold precipitated from the same boron-rich source as tourmaline.

Structural geology mapping using PALSAR data in the Bau gold mining district, Sarawak, Malaysia

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Pour, Amin Beiranvand; Hashim, Mazlan

2014-08-01

The application of optical remote sensing data for geological mapping is difficult in the tropical environment. The persistent cloud coverage, dominated vegetation in the landscape and limited bedrock exposures are constraints imposed by the tropical climate. Structural geology investigations that are searching for epithermal or polymetallic vein-type ore deposits can be developed using Synthetic Aperture Radar (SAR) remote sensing data in tropical/sub-tropical regions. The Bau gold mining district in the State of Sarawak, East Malaysia, on the island of Borneo has been selected for this study. The Bau is a gold field similar to Carlin style gold deposits, but gold mineralization at Bau is much more structurally controlled. Geological analyses coupled with the Phased Array type L-band Synthetic Aperture Radar (PALSAR) remote sensing data were used to detect structural elements associated with gold mineralization. The PALSAR data were used to perform lithological-structural mapping of mineralized zones in the study area and surrounding terrain. Structural elements were detected along the SSW to NNE trend of the Tuban fault zone and Tai Parit fault that corresponds to the areas of occurrence of the gold mineralization in the Bau Limestone. Most of quartz-gold bearing veins occur in high-angle faults, fractures and joints within massive units of the Bau Limestone. The results show that four deformation events (D1-D4) in the structures of the Bau district and structurally controlled gold mineralization indicators, including faults, joints and fractures are detectable using PALSAR data at both regional and district scales. The approach used in this study can be more broadly applicable to provide preliminary information for exploration potentially interesting areas of epithermal or polymetallic vein-type mineralization using the PALSAR data in the tropical/sub-tropical regions.

Origin of ore-forming fluids of the Haigou gold deposit in the eastern Central Asian Orogenic belt, NE China: Constraints from H-O-He-Ar isotopes

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Zeng, Qingdong; He, Huaiyu; Zhu, Rixiang; Zhang, Song; Wang, Yongbin; Su, Fei

2017-08-01

The Haigou lode deposit contains 40 t of gold at an average grade of 3.5 g/t, and is one of the largest deposits in the Jiapigou gold belt located along the eastern segment of the northern margin of the North China Craton. The deposit comprises 15 gold-bearing quartz veins hosted in a Carboniferous monzonite-monzogranite stock. Cretaceous dikes consisting of diorite, diabase, and granodiorite porphyries are well developed in the deposit. The diorite porphyry dikes (130.4 ± 6.3 Ma) occur together with gold-bearing quartz veins in NNE- and NE-striking faults. Gold-bearing quartz veins crosscut the diorite porphyry dikes, and the veins are in turn crosscut by E-W-striking 124.6 ± 2.2 Ma granodiorite porphyry dikes. The mineralization mainly occurs as auriferous quartz veins with minor amounts of sulfide minerals, including pyrite, galena, chalcopyrite, and molybdenite. Gold occurs as either native gold or calaverite. Common gangue minerals in the deposit include quartz, sericite, and calcite. The deposit is characterized by various types of hydrothermal alteration, including silicification, sericitization, chloritization, potassic alteration, and carbonatization. Three stages of hydrothermal activity have been recognized in the deposit: (1) a barren quartz stage; (2) a polymetallic sulfide (gold) stage; (3) a calcite stage. Fluid inclusions in hydrothermal pyrites have 3He/4He ratios of 0.3 to 3.3 Ra and 40Ar/36Ar ratios of 351 to 1353, indicating mixing of fluids of mantle and crustal origin. Hydrothermal quartz yielded δ18O values of -1.3‰ to +7.2‰ and δD values of fluid inclusions in the quartz vary between -80‰ and -104‰. These stable isotope data also suggest mixing of magmatic and meteoric fluids. Noble gas and stable isotopic data suggest that the ore fluids have a predominant mantle source with a significant crustal component. Based on the spatial association of gold-bearing quartz veins with early Cretaceous intrusions, and the H-O-He-Ar isotopic

SPHERICAL MICROPARTICLES FROM GOLD–BEARING QUARTZ VEINS OF THE IROKINDA DEPOSIT, WESTERN TRANSBAIKALIA

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A. V. Tatarinov

2016-01-01

Full Text Available We have studied the material composition of ore microparticles extracted from gold concentrates of operating quartz vein No. 30 located in the Irokinda deposit, Western Transbaikalia. We consider the origin of such microparticles in connection with our observation data and the previously published structural and geological features revealed in formation of the ore field, as well as tectonophysical conditions of formation of many gold-bearing quartz veins, including vein No. 30.Gold-quartz veins, located in the allochthonous plate thrusted onto the Kelyano-Irokinda belt (Fig. 1, infill the NE-striking fault zones. E.A. Namolov conducted the tectonophysical analysis of the “elementary fracture – ore-bearing suture/joint” system, which provided a genetic explanation of the morphology of ore quartz veins (including vein No. 30 and conditions for formation of their host fault zones. Ore-bearing fractures are combinations of shear and cleavage cracks that occur in case of certain positions of the strain ellipsoid in conditions of horizontal compression. Due to repeated intra-mineralization displacements, the texture of the ores is strappy, and the quartz matrix of the veins contains numerous inclusions of host rocks.The spherical particles have zonal structures and consist of metal nodes and external continuous or discontinuous shells, which thickness ranges from 10 to 400 microns (Fig. 2, Fig. 3. The nodes are composed mainly of native Fe with admixtures of Fe, Mn, Al (Table, the contents of which are typically less than 1.0–1.5 wt %.Characteristic features of the mineral composition of shells of the spheroidal microparticles:– The widespread graphite matrix consisting of minerals of different classes, except for native;– Pyrite in the group of ore oxides of Fe, Mn, Cr, Ti;– A large group of carbonate minerals;– Feldspars and natrosilite among silicates;– The mineral with CaBr2 composition;– Mono-mineral quartz rims

Geochemical Characteristics of Metamorphic Rock-Hosted Gold Deposit At Onzon-Kanbani Area, Central Myanmar

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Aung Tay Zar

2017-09-01

Full Text Available Gold and associated base metal mineralization of Onzon-Kabani area located in the western border of generally N-S trending Mogoke Metamorphic Belt where well-known Sagaing fault is served as a western boundary of this area. In this research area, many artisanal and small-scale gold mines were noted in last three decades. Gold mineralization is hosted in marble and gneiss unit of research area but most common in marble unit. Variety of igneous intrusions are also observed in research area. Mineralizations are observed as fissure filling veins as well as lesser amount of disseminated nature in marble unit. Mineralogically, gold are associated with other base metal such as pyrite, galena, sphalerite, chalcopyrite, marcasite and arsenopyrite. Hydrothermal alteration halos are developed in peripheral of hydrothermal conduits or mineralization veins from proximal to distal such as 1 silicic, 2 sericite-illite, and 3 propylitic alteration.  Most of hydrothermal minerals from each altered zones showed that near neutral condition of pH (e.g. adularia, calcite, illite, sericite and chlorite. Alternatively, hydrothermal alteration zones that show with ore minerals such as native gold, electrum, sphalerite, galena, chalcopyrite, arsenopyrite and marcasite which mostly observed in silicic alteration zone. Typical boiling characters of vein textures and fluid inclusion petrography are observed in hydrothermal system of research area. Boiling, cooling and mixing are possiblily responsible for gold deposition in hydrothermal system. In this paper, authors are documented to clarify the type of mineralization based on hydrothermal alterations, ore and gangue mineral assemblages and fluid inclusion study. All of these data can describe and play an important role for both with respect to understanding deposit genesis and in mineral exploration.

Sclerotherapy of Varicose Veins and Spider Veins

Science.gov (United States)

... Index A-Z Sclerotherapy of Varicose Veins and Spider Veins Sclerotherapy uses injections from a very fine, ... Sclerotherapy? What is Sclerotherapy of Varicose Veins and Spider Veins? Sclerotherapy is a minimally invasive treatment used ...

Study of tibial nerve regeneration in Wistar rats in primary neurorrhaphy with and without gap, wrapped in vein segments.

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Bastos Dos Santos, Ewerton; Fernandes, Marcela; Gomes Dos Santos, João Baptista; Mattioli Leite, Vilnei; Valente, Sandra Gomes; Faloppa, Flávio

2012-01-01

This study compared nerve regeneration in Wistar rats, using epineural neurorrhaphy with a gap of 1.0 mm and without a gap, both wrapped with jugular vein tubes. Motor neurons in the spinal cord between L3 and S1 were used for the count, marked by exposure of the tibial nerve to Fluoro-Gold (FG). The tibial nerves on both sides were cut and sutured, with a gap on one side and no gap in the other. The sutures were wrapped with a jugular vein. Four months after surgery the tibial nerves were exposed to Fluoro-Gold and the motor neuron count performed in the spinal cord. The results were statistically analyzed by the paired Wilcoxon test. There was a statistical difference between the groups with and without gap in relation to the motor neuron count (p=0.013). The epineural neurorraphy without gap wrapped with jugular vein showed better results for nerve regeneration than the same procedure with gap. Experimental Study .

Carbon-oxygen isotopes and rare earth elements as an exploration vector for Carlin-type gold deposits: A case study of the Shuiyindong gold deposit, Guizhou Province, SW China

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Tan, Qin-Ping; Xia, Yong; Wang, Xueqiu; Xie, Zhuo-Jun; Wei, Dong-Tian

2017-10-01

The Shuiyindong gold deposit is a deeply concealed strata-bound Carlin-type deposit in southwestern Guizhou Province, China. The deposit lies on the eastern limb of the Huijiabao anticline with ores mainly along the anticline axis and hosted in bioclastic limestone, containing calcite veins, of the Permian Longtan Formation units. In this study, we measured carbon and oxygen isotopic ratios and rare earth element (REE) concentrations of the host rocks and calcite veins along a profile across the Shuiyindong deposit. Orebodies in the upper unit of the Longtan Formation have higher δ18O values (20.6-22.4‰) and lower δ13C values (-3.7 to -0.5‰) than the country rocks (δ18O: 18.8-21.4‰; δ13C: -0.7 to 0.8‰). However, there are no obvious trends of δ18O and δ13C values from the country rocks to the orebodies in the middle unit of the Longtan Formation. The spatial distribution of the calcite veins displays distinct halos of δ13C and δ18O values and REE concentrations. Calcite veins along the anticlinal axis and major reverse fault are enriched in Middle REE (Sm, Eu, Gd, and Tb) and 18O and depleted in 13C. Surficial veining calcite-filled fractures/faults that connect to deep concealed strata-bound gold mineralization systems can be vectors toward deep ores in southwestern Guizhou Province, China.

Gold nanoparticles administration induced prominent inflammatory, central vein intima disruption, fatty change and Kupffer cells hyperplasia

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Abdelhalim Mohamed

2011-08-01

Full Text Available Abstract Background Advances in nanotechnology have identified promising candidates for many biological, biomedical and biomedicine applications. They are being increasingly exploited for medical uses and other industrial applications. The aim of the present study was to investigate the effects of administration of gold nanoparticles (GNPs on inflammatory cells infiltration, central vein intima disruption, fatty change, and Kupffer cells hyperplasia in the hepatic tissue in an attempt to cover and understand the toxicity and the potential threat of their therapeutic and diagnostic use. Methods A total of 70 healthy male Wistar-Kyoto rats were exposed to GNPs received 50 or 100 μl of GNPs infusion of 10, 20 and 50 nm GNPs for 3 or 7 days. Animals were randomly divided into groups, 12 GNPs-treated rats groups and one control group (NG. Groups 1, 2 and 3 received infusion of 50 μl GNPs of size 10 nm (3 or 7 days, size 20 nm (3 or 7 days and 50 nm (3 or 7 days, respectively; while groups 4, 5 and 6 received infusion of 100 μl GNPs of size 10 nm, size 20 nm and 50 nm, respectively. Results In comparison with respective control rats, exposure to GNPs doses has produced alterations in the hepatocytes, portal triads and sinusoids. The alterations in the hepatocytes were mainly vacuolar to hydropic degeneration, cytopasmic hyaline vacuolation, polymorphism, binucleation, karyopyknosis, karyolysis, karyorrhexis and necrosis. In addition, inflammatory cell infiltration, Kupffer cells hyperplasia, central veins intima disruption, hepatic strands dilatation and occasional fatty change together with a loss of normal architechiture of hepatic strands were also seen. Conclusions The alterations induced by the administration of GNPs were size-dependent with smaller ones induced more affects and related with time exposure of GNPs. These alterations might be an indication of injured hepatocytes due to GNPs toxicity that became unable to deal with the

Gold grade of epithermal gold ore at Lamuntet, Brang Rea, West Sumbawa District, West Nusa Tenggara Province, Indonesia

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Ernawati, Rika; Idrus, Arifudin; TBMP, Himawan

2017-06-01

Lamuntet is one of gold ore mining area carried out by the Artisanal Small scale Gold Mining (ASGM) located in West Sumbawa, Indonesia. Most of the miners at this area are not the local miners but also those from other regions. Mineralization of this area is strong identified as low sulfidation epithermal system. There are two blocks of this mining location, namely, Ngelampar block with an area of 0.164 km2 and Song block with an area of 0.067 km2. This study was focused on Ngelampar block. The characteristic of epithermal system is the existence of quartz vein with comb, vuggy, and sugary texture. The aim of this research was to analyze the gold grade and other metals, such as Cu, Ag, Pb, As, Zn, and Hg. The research methods included literature study from previous researches, field work, laboratory work, and interpretation. The literature study was performed on previous researches with similar study area. The field work comprised of direct observation and sampling. Fieldwork was done for a week to obtain gold ore/vein. Sixteen samples were analyzed to obtain the grade of ore/metal. The Hg laboratory analysis was then performed on the six samples with the highest gold grade. Laboratory works were conducted at Intertek Jakarta by using Fire Assay (FA) for gold grade and Atomic Absorption Spectrophotometry (AAS) for Cu, Ag, Pb, As, Zn, and Hg. Results of the analysis showed the range of Au was grade (0.1 ppm - 27.8 ppm), Cu was 26 ppm -1740 ppm, Pb was 101 ppm- >4000 ppm, Zn of 73 ppm- >10,000 ppm, Ag of 3 ppm -185 ppm, As was 150 ppm-6530 ppm, and Hg of 0.08 ppm - 1.89 ppm. L1 and L15 had high grade for all values (Au, Ag, Zn, Cu, As, and Hg). Gold mineralization was formed as electrum because of Ag content is higher than 20%. Associated minerals of the samples in the study area were galena, sphalerite, arsenopyrite, and chalcopyrite which showed the characteristic of rich base metal of Pb, Zn, and Cu at LS epithermal.

The usefulness and the limitation of MR angiography for the evaluation of colateral veins in portal hypertension

International Nuclear Information System (INIS)

Komazaki, Toshio

1994-01-01

The usefulness and the limitation of magnetic resonance angiography (MRA) for the assessment of the portal vein and its branches, i.e., the collateral veins of portal hypertensive patients, were studied. In a total of 22 patients with portal hypertension, both MRA and percutaneous transhepatic portography (PTP) were done at the same time. MRA and PTP images were read at random by three observers. The discriminative scores, decided from the grades of clearness of images, were calculated for six portal venous vessels. The discrimination of the portal vein, splenic vein, paraumbilical vein and gastrorenal shunt was easy on condition that they were clearly visualized by PTP. Thus the accuracy of MRA, which was calculated by comparing it with PTP, the gold standard, was high and above 95%. Regarding the left gastric vein and short gastric vein, the accuracy of MRA were lower than the former four vessels but were still above 80%. MRA, the noninvasive method, seems useful for the first choice to see the total image of portal venous system. (author)

Duplex scanning in the diagnosis of acute deep vein thrombosis of the lower extremity

NARCIS (Netherlands)

van Ramshorst, B.; Legemate, D. A.; Verzijlbergen, J. F.; Hoeneveld, H.; Eikelboom, B. C.; de Valois, J. C.; Meuwissen, O. J.

1991-01-01

In a prospective study the value of duplex scanning in the diagnosis of acute femoro-popliteal thrombosis was compared to conventional contrast venography (CV) as a gold standard. A total of 126 legs in 117 patients suspected of having deep vein thrombosis (DVT) or pulmonary embolism (PE) were

Impact of Laser Fiber Design on Outcome of Endovenous Ablation of Lower-Extremity Varicose Veins: Results from a Single Practice

International Nuclear Information System (INIS)

Prince, Ethan A.; Soares, Gregory M.; Silva, MaryLou; Taner, Anil; Ahn, SunHo; Dubel, Gregory J.; Jay, Bryan S.

2011-01-01

The design of laser fibers used for endovenous laser ablation (EVLA) in the management of lower-extremity varicose vein disease may affect treatment success. The purpose of this investigation is to report our experience using the gold-tip NeverTouch VenaCure laser fiber (AngioDynamics, Queensbury, NY) and to compare that to our experience with standard bare-tip fibers. A retrospective chart review of 363 consecutive EVLA treatments using the gold-tip laser fiber was performed. Demographic data including patient age, sex, history of previous varicose vein stripping, vein identity, laterality, treatment length, total applied energy in joules (J), use of adjuvant sclerotherapy and ambulatory phlebectomy, treatment-related complications, and treatment failure, which was defined as recanalization of any portion of the treated vein during follow-up as assessed by duplex ultrasound examination―were entered into a spreadsheet. These data were compared with a control group of 471 EVLA treatments performed with a standard bare-tip laser fiber. Data were analyzed using independent-samples Student’s t test, chi-square test, and multivariate analysis. Demographic data were similar between the two groups. Treatments with the gold-tip fiber had a failure rate of 11.1%, whereas treatment with a bare-tip fiber had a failure rate of 2.3% during a similar follow-up period. This difference was highly statistically significant (p < 0.0001). Multivariate analysis showed fiber type as the most significant factor associated with treatment failure. We conclude that laser fiber design has a significant effect on treatment success in the performance of EVLA.

Pelvic Vein Embolisation in the Management of Varicose Veins

International Nuclear Information System (INIS)

Ratnam, Lakshmi A.; Marsh, Petra; Holdstock, Judy M.; Harrison, Charmaine S.; Hussain, Fuad F.; Whiteley, Mark S.; Lopez, Anthony

2008-01-01

Pelvic vein incompetence is common in patients with atypical varicose veins, contributing to their recurrence after surgery. Therefore, refluxing pelvic veins should be identified and treated. We present our experience with pelvic vein embolisation in patients presenting with varicose veins. Patients presenting with varicose veins with a duplex-proven contribution from perivulval veins undergo transvaginal duplex sonography (TVUS) to identify refluxing pelvic veins. Those with positive scans undergo embolisation before surgical treatment of their lower limb varicose veins. A total of 218 women (mean age of 46.3 years) were treated. Parity was documented in the first 60 patients, of whom 47 (78.3%) were multiparous, 11 (18.3%) had had one previous pregnancy, and 2 (3.3%) were nulliparous. The left ovarian vein was embolised in 78%, the right internal iliac in 64.7%, the left internal iliac in 56.4%, and the right ovarian vein in 42.2% of patients. At follow-up TVUS, mild reflux only was seen in 16, marked persistent reflux in 6, and new reflux in 3 patients. These 9 women underwent successful repeat embolisation. Two patients experienced pulmonary embolisation of the coils, of whom 1 was asymptomatic and 1 was successfully retrieved; 1 patient had a misplaced coil protruding into the common femoral vein; and 1 patient had perineal thrombophlebitis. The results of our study showed that pelvic venous embolisation by way of a transjugular approach is a safe and effective technique in the treatment of pelvic vein reflux.

Geometallurgical Study of a Gravity Recoverable Gold Orebody

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Simon C. Dominy

2018-04-01

Full Text Available Sheeted vein gold deposits are often characterised by multiple sub-parallel veins and free-milling coarse gold. Inherent mineralisation heterogeneity results in grade and process parameter variability, which increases project risk if not quantified. Measured grade variability is often exacerbated by poorly designed sampling and testwork protocols. Protocols that are optimised within the framework of the Theory of Sampling (TOS to suit the ore type, together with quality assurance/quality control systems, will reduce variability and provide fit-for-purpose results. Geometallurgy can be broadly split into two key approaches: strategic and tactical (or operational. The strategic approach focuses on the whole orebody and long-term life-of-mine view, whereas tactical geometallurgy relates to a more short- to medium-term view during mining. The geometallurgical approach requires spatially distributed samples within a deposit to support variability modelling. Diverse attributes from core logging, mineralogical/textural determination and small-scale tests are used to measure variability. This contribution presents a case study that emphasises an early-stage strategic geometallurgical programme applied to a gravity recoverable gold (GRG dominated deposit. It exemplifies how data can be acquired from a well-designed and planned programme to support resource estimation, a pre-feasibility study, trial mining and fast-track to production. A tactical geometallurgical programme is embedded into the mine operation.

The formation of auriferous quartz-sulfide veins in the Pataz region, northern Peru: A synthesis of geological, mineralogical, and geochemical data

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Schreiber, D. W.; Amstutz, G. C.; Fontboté, L.

1990-12-01

The Pataz region in the eastern part of the North Peruvian Department La Libertad hosts a number of important gold mining districts like La Lima, El Tingo, Pataz, Parcoy, and Buldibuyo. Economic gold mineralization occurs in quartz-sulfide veins at the margin of the calc-alkaline Pataz Batholith, that mainly consists of granites, granodiorites, and monzodiorites. The batholith is of Paleozoic age and cuts the Precambrian to Early Paleozoic low-grade metamorphic basement series. Its intrusion was controlled by a NNW-trending fault of regional importance. The gold-bearing veins are characterized by a two-stage sulfide mineralization. Bodies of massive pyrite and some arsenopyrite were formed in stage 1, and after subsequent fracturing they served as sites for deposition of gold, electrum, galena, sphalerite, and chalcopyrite. It is concluded that gold was transported as a AuCl{2/-}-complex by oxidizing chloride solutions and deposited near older pyrite by micro-scale redox changes and a slight temperature decrease. Mineralogical, textural, geochemical, and microthermometric features are interpreted as a consequence of mineralization at considerable depth produced by a hydrothermal system linked with the emplacement of the Pataz Batholith. acteristics in order to outline a general physicochemical model of the hydrothermal ore-forming processes.

Morphology and composition of gold in a lateritic profile, Fazenda Pison “Garimpo”, Amazon, Brazil

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Larizzatti, J. H.; Oliveira, S. M. B.; Butt, C. R. M.

2008-05-01

This study describes the morphological evolution of gold grains in a lateritic weathering profile in an equatorial rainforest climate. Primary sources of gold are quartz veins associated with shallow granophyric intrusion. Gold grains were found in fresh ore, saprolite, transition zones, ferruginous duricrust, red latosol, and yellow latosol. Irregularly shaped grains predominate, with smaller proportions of dendritic and prismatic forms. Gold grains are weathered in the uppermost 10 m of the regolith. Mean gold grain size is maximum in the duricrust (>125 μm) and decreases progressively upward into the yellow latosol (duricrust formation may preserve some grains as large aggregates, but subsequent transformation into latosol further modifies them.

The Porgera gold deposit, Papua, New Guinea, 2: sources of metals

International Nuclear Information System (INIS)

Richards, J.P.; McCulloch, M.T.; Kerrich, R.

1991-01-01

Sr and Pb isotopic studies of mineralized rocks and veins from the Porgera gold deposit indicates that these components were derived from a mixture of sedimentary and igneous sources, probably located within the Om Formation which underlies (< 3 km depth) the presently exposed Porgera Intrusive Complex (PIC) and associated ore deposit. Gold abundances in least-altered samples correlate with PGE, and indicate that the parental magma was mil enriched in Au and Pt-group elements relative to the Ir-group. (author)

Alteration and petrology of Intrusive Rocks associated with Gold Mineralization at Kuh-E-Zar Gold Deposit, Torbat-e-Heydaryeh

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Alireza Mazloumi Bajestani

2009-09-01

Full Text Available Kuh- e -Zar gold deposit located 35 km west of Torbat-e-Heydaryeh, (Khorassan e- Razavi province, East of Iran. This deposit is a specularite-rich Iron oxide type (IOCG. This mine is situated within Khaf-Bardascan volcanic plutonic belt. Based on recent exploration along this belt, several IOCG type system plus Kuh-e-Zar deposit are discovered. In the study area, several type of tuff and lava having acid to intermediate composition are identified (upper Eocene. Oligo-Miocene granite, granodiorite, synogranite and monzonite intruded upper Eocene andesite-dacite-rhyolite. Intrusive rocks are meta-aluminous, medium to high-K series I-type. Based on spider diagram, intrusive rocks show enrichment in LILE = K, Th, Rb and depletion in HFSE = Nb, Sr, Ti. Based geochemistry of igneous rock, they formed in continental margin subduction zone. Propylitic (chlorite alteration is dominated and covers large area. Silicification is restricted only to mineralized zones. Argillic and albitization is found in certain location and cover small areas. The style of mineralization was controlled by the type and geometry of fault zones. Mineralization is found as vein, stockwork and breccias. Hypogene mineral Paragenesis include: specularite-quartz-gold-chlorite ± chalcopyrite ± pyrite ± galena ± barite. Secondary minerals formed due to oxidation are: goethite, limonite, lepidocrucite, Malachite, Azurite, Covelite, Cerucite, hydrocerucite, Pyrolusite and Smitsonite. In a few localities, chalcopyrite and minor pyrite and galena are found. Based on SEM analysis gold is present as electrum. Mineralization appeared in different type such as vein, stockwork and Hydrothermal breccia in strike sleep fault zone which are hidden inside volcano plutonic rocks. The average gold grade is between 3.02 ppm and ore reserve is estimated more than 3 million tons (cut off grade = 0.7 ppm.

Age of mineralization of the Nansatsu type gold deposits, Kagoshima, Japan

International Nuclear Information System (INIS)

Izawa, Eiji; Urashima, Yukitoshi; Okubo, Yoshikazu.

1984-01-01

Gold-bearing massive silicified rocks occur in the volcanic piles of the Neogene Tertiary age in the Makurazaki district, southern Kyushu and are termed as the Nansatsu type gold deposits. Currently three mines, Kasuga, Iwato and Akeshi, are operating. The argillized zones consisting mainly of quartz, kaolinite and minor goethite surround the silicified rocks. Alunite series minerals occur in and around the silicified rocks. Ages of mineralization have been discussed for many years but were unanswered. K-Ar dating of selected alunite and alunite-bearing rocks from three mines yields ages of 5.5 - 3.7 m.y. K-Ar ages at Mt. Sonomi of the Kasuga mine (5.5 +- 0.4 m.y.) and at the Arabira orebody of the Iwato mine (4.7 +- 1.0 m.y.) probably represent the ages of gold mineralization. Slightly younger ages at Mt. Iwato of the Iwato mine (4.4 +- 0.7 m.y.) and at the No. 1 orebody of the Akeshi mine (3.7 +- 1.1 m.y.) might reflect possible changes in chemical composition of alunite during weathering after mineralization. Gold-silver mineralization in southern Kyushu took place in the Pliocene to early Pleistocene, except minor silver-rich vein type deposits in the middle Miocene time. This study shows that four values are concordant with each other and indicate the latest Miocene to early Pliocene ages for mineralization of the Nansatsu type gold deposits in the Makurazaki district. The ages are comparable with the vein type gold deposits of the early Pliocene time such as Kushikino (4.0 +- 0.3 m.y.) and Hanakago (4.8 +- 2.9 m.y.). Another gold mineralization were known in the early Pleistocene time such as Hishikari (1.5 +- 0.3 m.y.) and Ora (1.8 +- 0.2 m.y.). At present there seems to be only minor gold mineralization between 4 and 2 m.y. (author)

Rb-Sr, K-Ar, and stable isotope evidence for the ages and sources of fluid components of gold-bearing quartz veins in the northern Sierra Nevada foothills metamorphic belt, California

Science.gov (United States)

Böhlke, John Karl; Kistler, R. W.

1986-01-01

Gold-bearing quartz veins occur in and near major fault zones in deformed oceanic and island-arc rocks west of the main outcrop of the Sierra Nevada composite batholith. Veins typically occupy minor reverse faults that crosscut blueschist to amphibolite-grade metamorphic rocks whose metamorphic ages range from early Paleozoic to Jurassic. Vein micas and carbonate-quartz-mica assemblages that formed by hydrothermal metasomatism of ultramafic wall rocks in the Alleghany, Grass Valley, Washington, and Mother Lode districts yield concordant K-Ar and Rb-Sr ages. The dated veins are significantly younger than prograde metamorphism, penetrative deformation, and accretion of their host rocks to the continental margin. New and previously published mineralization ages from 13 localities in the Sierra foothills range from about 140 to 110 m.y. ago, with mean and median between 120 and 115 m.y. The age relations suggest that mineralizing fluids were set in motion by deep magmatic activity related to the resumption of east-dipping subduction along the western margin of North America following the Late Jurassic Nevadan collision event.CO 2 -bearing fluids responsible for metasomatism and much of the vein mica, carbonate, albite, and quartz deposition in several northern mines were isotopically heavy (delta 18 O [asymp] 8-14ppm; delta D between about -10 and -50ppm) and do not resemble seawater, magmatic, or meteoric waters. Metasomatic and vein-filling mica, dolomite, magnesite, and quartz in altered ultramafic rocks generally formed from fluids with similar Sr and O isotope ratios at a given locality. Consistent quartz-mica delta 18 O fractionations (delta 18 O (sub Q-M) = 4.5-4.9ppm) from various localities imply uniform equilibration temperatures, probably between 300 degrees and 350 degrees C. On a local (mine) scale, fluids responsible for both carbonate alteration of mafic and ultramafic wall rocks and albitic alteration of felsic and pelitic rocks had similar Sr isotope

Characterization of gold mineralization in Garin Hawal area, Kebbi State, NW Nigeria, using remote sensing

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Talaat M. Ramadan

2010-12-01

Full Text Available Garin Hawal area, Kebbi State, NW Nigeria is part of the Neoproterozoic to Early Phanerozoic terrane separating the west African and Congo Cratons. Three main gold-bearing shear zones were detected in the study area from the processed Landsat ETM+ images and extensive ground investigation. Field and petrographical studies indicate that the Neoproterozoic rocks are represented by a highly folded and faulted belt constituted of hornblende, muscovite and graphite schist. They are intruded by granondiorites and late to post granitic dykes. Extensive alteration zones were identified using high resolution QuickBird image along Garin Hawal shear zone. The alteration zones and associated quartz veins are generally concordant with the main NE–SW regional structural trend and are dipping to the NW. Geochemical studies indicate that the gold content reaches 8 g/t in the alteration zones, while it reaches up to 35 g/t in the quartz veins. Mineralogical studies indicate that the alterations are strongly potassium-enriched. Pyrophyllite, kaolinite, illite, gypsum and quartz also occur. The main ore minerals are gold, chalcopyrite, arsenopyrite, pyrite, galena and iron oxides. This study indicates that the alteration zones and the associated quartz veins in the muscovite schist are promising and need more detailed exploration for Au and Ag mineralization to evaluate their potential.

Varicose vein stripping

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... stripping; Venous reflux - vein stripping; Venous ulcer - veins Patient Instructions Surgical wound care - open Varicose veins - what to ask your doctor Images Circulatory system References American Family Physician. Management of varicose veins. www.aafp.org/afp/2008/ ...

Application of geophysical methods to gold prospecting in Minas de Corrales, Uruguay

International Nuclear Information System (INIS)

Costa, Antonio Flavio U.; Dias, Rogerio Aguirre; Barcelos, Andre B.B. de

1993-01-01

Geophysical methods were tested in San Gregorio gold mine, Minas de Corrales, north region of Uruguay. The ores are mainly stockworks, sheeted veinlet zones, ore shoot and disseminated sulfides types, situated in a silicated and carbonated shear zone structure, over granitic mylonites, quartz diorites, quartz-feldspathic breccia, basic rocks and quartz veins. Magnetic and radiometric methods were applied . VLF and EM34-3 detected the high resistivity silicated and carbonated zone and IP detected a weak PFE anomaly associated with pyrite/gold zone. (author)

Uranium deposits in the Eureka Gulch area, Central City district, Gilpin County, Colorado

Science.gov (United States)

Sims, P.K.; Osterwald, F.W.; Tooker, E.W.

1954-01-01

The Eureka Gulch area of the Central City district, Gilpin County, Colo., was mined for ores of gold, silver, copper, lead, and zinc; but there has been little mining activity in the area since World War I. Between 1951 and 1953 nine radioactive mine dumps were discovered in the area by the U.S. Geological Survey and by prospectors. the importance of the discoveries has not been determined as all but one of the mines are inaccessible, but the distribution, quantity, and grade of the radioactive materials found on the mine dumps indicate that the area is worth of additional exploration as a possible source of uranium ore. The uranium ans other metals are in and near steeply dipping mesothermal veins of Laramide age intrusive rocks. Pitchblende is present in at least four veins, and metatorbernite, associated at places with kosolite, is found along two veins for a linear distance of about 700 feet. The pitchblends and metatorbernite appear to be mutually exclusive and seem to occur in different veins. Colloform grains of pitchblende were deposited in the vein essentially contemporaneously with pyrite. The pitchblende is earlier in the sequence of deposition than galena and sphalerite. The metatorbernite replaces altered biotite-quartz-plagioclase gneiss and altered amphibolite, and to a lesser extent forms coatings on fractures in these rocks adjacent to the veins; the kasolite fills vugs in highly altered material and in altered wall rocks. Much of the pitchblende found on the dumps has been partly leached subsequent to mining and is out of equilibrium. Selected samples of metatorbernite-bearing rock from one mine dump contain as much as 6.11 percent uranium. The pitchblende is a primary vein mineral deposited from uranium-bearing hydrothermal solutions. The metatorbernite probably formed by oxidation, solution, and transportation of uranium from primary pitchblende, but it may be a primary mineral deposited directly from fluids of different composition from these

A Palaeoproterozoic multi-stage hydrothermal alteration system at Nalunaq gold deposit, South Greenland

DEFF Research Database (Denmark)

Bell, Robin-Marie; Kolb, Jochen; Waight, Tod Earle

2017-01-01

Nalunaq is an orogenic, high gold grade deposit situated on the Nanortalik Peninsula, South Greenland. Mineralisation is hosted in shear zone-controlled quartz veins, located in fine- and medium-grained amphibolite. The deposit was the site of Greenland’s only operating metalliferous mine until i...

Portal Vein Thrombosis

Directory of Open Access Journals (Sweden)

Hakan Demirci

2016-01-01

Full Text Available Portal vein thrombosis is an important cause of presinusoidal portal hypertension. Portal vein thrombosis commonly occurs in patient with cirrhosis, malignancy and prothrombotic states. Patients with acute portal vein thrombosis have immediate onset. Patients with chronic portal vein thrombosis have developed portal hypertension and cavernous portal transformation. Portal vein thrombosis is diagnosed with doppler ultrasound, computed tomography and magnetic resonance imaging. Therapy with low molecular weight heparin achieves recanalization in more than half of acute cases.

Collateral veins in left renal vein stenosis demonstrated via CT

Energy Technology Data Exchange (ETDEWEB)

Lien, H.H.; Lund, G.; Talle, K.

1983-02-01

Twelve patients with left renal vein stenosis from tumor compression were studied with CT. All had distended collateral veins in the perirenal space which either formed a radiating or a cobweb pattern or appeared as marked longitudinal veins. Inferior phrenic vein branches were seen in seven patients and were considerably enlarged in two. Other major veins possibly taking part in collateral circulation could not be recognized due to obliteration of fat planes. The renal fascia was thickened in eleven patients, probably due to edema. A close study of the perirenal space with CT may give valuable information about collateral development.

Collateral veins in left renal vein stenosis demonstrated via CT

International Nuclear Information System (INIS)

Lien, H.H.; Lund, G.; Talle, K.

1983-01-01

Twelve patients with left renal vein stenosis from tumor compression were studied with CT. All had distended collateral veins in the perirenal space which either formed a radiating or a cobweb pattern or appeared as marked longitudinal veins. Inferior phrenic vein branches were seen in seven patients and were considerably enlarged in two. Other major veins possibly taking part in collateral circulation could not be recognized due to obliteration of fat planes. The renal fascia was thickened in eleven patients, probably due to edema. A close study of the perirenal space with CT may give valuable information about collateral development. (orig.)

Adrenal Vein Sampling for Conn's Syndrome: Diagnosis and Clinical Outcomes.

Science.gov (United States)

Deipolyi, Amy R; Bailin, Alexander; Wicky, Stephan; Alansari, Shehab; Oklu, Rahmi

2015-06-19

Adrenal vein sampling (AVS) is the gold standard test to determine unilateral causes of primary aldosteronism (PA). We have retrospectively characterized our experience with AVS including concordance of AVS results and imaging, and describe the approach for the PA patient in whom bilateral AVS is unsuccessful. We reviewed the medical records of 85 patients with PA and compared patients who were treated medically and surgically on pre-procedure presentation and post-treatment outcomes, and evaluated how technically unsuccessful AVS results were used in further patient management. Out of the 92 AVS performed in 85 patients, AVS was technically successful bilaterally in 58 (63%) of cases. Either unsuccessful AVS prompted a repeat AVS, or results from the contralateral side and from CT imaging were used to guide further therapy. Patients who were managed surgically with adrenalectomy had higher initial blood pressure and lower potassium levels compared with patients who were managed medically. Adrenalectomy results in significantly decreased blood pressure and normalization of potassium levels. AVS can identify surgically curable causes of PA, but can be technically challenging. When one adrenal vein fails to be cannulated, results from the contralateral vein can be useful in conjunction with imaging and clinical findings to suggest further management.

Gold in primary high thermal transformations of the Au porphyry deposit Biely vrch

International Nuclear Information System (INIS)

Kozak, J.; Kodera, P.; Lexa, J.; Chovan, M.

2014-01-01

Porphyry gold deposit Biely vrch is situated in northern part of the Javorie stratovolcano in eastern part of Central Slovakia Volcanic Field. Intrusion of diorite to andesite porphyry with andesites is affected by hydrothermal alterations with dominant intermediate argillic alteration. Accumulations of gold are spatially associated with stockwork, formed by different types of quartz veinlets. Gold grains occur in altered rocks in the vicinity of quartz veinlets and rarely also as inclusions in vein. Analysed gold grains are chemically very homogenous and have fineness between 87 to 99.50 wt % Au while silver is the only significant element in addition to gold. In deeper parts of the deposit gold also occurs associated with K and Ca-Na silicate alteration which confirms precipitation of gold already in early stages of the hydrothermal system from high salinity Fe-K rich salt melt based on analyses of corresponding fluid inclusions. Difference in the fineness of gold is not significant between primary and secondary hydrothermal alterations. The highest fineness of gold (more than 99 wt %) in advanced argillic alteration is probably caused by remobilisation by acidic hydrothermal fluids. (authors)

Focus on Varicose Veins

Science.gov (United States)

... because the valves of the veins no longer work. Under the pressure of gravity these veins can continue to expand and, in ... and to determine whether the vein valves are work- ing properly or have ... painless. How are varicose veins treated? Varicose veins are always ...

Ultrasonographic analysis in vitro of parietal thickness of lower limb varicose veins.

Science.gov (United States)

Bruschi, E; Como, G; Zuiani, C; Segatto, E; Rocco, M; Biasi, G; Bazzocchi, M

2006-09-01

The aim of this study was to evaluate the ability of ultrasound (US) to measure the parietal thickness of varicose veins. In a blind in vitro analysis, 28 great saphenous veins, obtained after stripping surgery from 28 patients with chronic venous insufficiency, were examined with a digital US scanner ATL-HDI5000, linear 5-1 to 2-MHz broadband probe, compound imaging technique and analogic-digital zooming. We obtained one to three progressive measurements for each vein wall (total 67 parietal thicknesses). The samples, fixed in formalin, were sent to the pathology laboratory: sections were obtained at the same level of the sonographic planes, and images were obtained by digital camera mounted on an optical microscope. Measurements obtained at histology were considered as the gold standard. K-statistic was applied to compare sonographic and histologic measurements. Considering only the hypoechoic wall portion, 29/29 (100%) diagnoses of hypotrophy (K=0.91), 19/22 (86%) diagnoses of normotrophy (K=0,47) and 12/16 (75%) diagnoses of hypertrophy (K=0.7) were obtained by sonography. In our preliminary experience, the in vitro study of varicose veins allows precise, at least morphological, detection of hypotrophic walls. If these preliminary data are confirmed in vivo, sonography could be used to discriminate patients eligible for conservative treatment instead of surgery.

Determination of gold by neutron activation analysis in some selected precambrian rocks from Eastern India

International Nuclear Information System (INIS)

Das, N.R.; Bhattacharyya, S.N.; Chakraborty, P.S.

1976-01-01

Gold was determined in epidiorite schist from Kunderkocha, in green phyllite from near Sausel in granodiorite from Kunderkocha and in galena quartz vein from Sausel by neutron activation analysis. The analysis was carried out both in destructive and non-destructive ways followed by γ-ray spectrometry. The process of preconcentration involves digestion of the rock samples with hydrofluoric acid and its dissolution in aqua regia solution, extraction of gold from the aqua regia solution by methylisobutyl ketone, back extraction of gold from the organic to the aqueous layer, and coprecipitation of gold by a known amount (0.7 g) of lead sulphide. The amounts of gold that were determined in the respective rock samples varied in the range 10 -4 -10 -6 %. Besides gold, some other trace constituents such as As, Ag, Sb, W, Se, La, Sn, etc. were also detected and their approximate order of occurence was determined. (T.G.)

A single-centre experience of the implementation of adrenal vein sampling procedure: the impact on the diagnostic work-up in primary aldosteronism

NARCIS (Netherlands)

Kadziela, J.; Prejbisz, A.; Michalowska, I.; Kolodziejczyk-Kruk, S.; Schultze Kool, L.J.; Kabat, M.; Janaszek-Sitkowska, H.; Toutounchi, S.; Galazka, Z.; Ambroziak, U.; Bednarczuk, T.; Ptasinska-Wnuk, D.; Hoffmann, M.; Januszewicz, M.; Januszewicz, A.; Witkowski, A.

2017-01-01

BACKGROUND: Primary aldosteronism is one of the most common causes of secondary hypertension. Adrenal vein sampling (AVS) remains a "gold standard" procedure in differentiation between unilateral (adenoma) and bilateral (hyperplasia) disease. AIM: The aim of this study was to present our

Adrenal vein sampling: substantial need for technical improvement at regional referral centres.

Science.gov (United States)

Elliott, Panda; Holmes, Daniel T

2013-10-01

Adrenal vein sampling (AVS) is the gold standard for localization of aldosterone producing adenoma. The anatomy of the right adrenal vein makes this procedure technically demanding and it may yield no clinical information if the adrenal veins are not adequately cannulated. Having frequently observed the technical failure of AVS, we undertook a review of 220 procedures in British Columbia, Canada. Subjects were retrospectively identified through the laboratory information system. The following were collected: demographics, screening aldosterone concentration and renin activity/mass, results of dynamic function tests, AVS aldosterone and cortisol results. Standard calculations were performed on AVS data and site-specific success rates were compared. The effect of adrenocorticotropin hormone (ACTH) stimulation on the selectivity index (SI) and lateralization index (LI) were explored. The overall technical success-rate of AVS procedures was only 44% in procedures where no ACTH-stimulation was used (n=200) but this rose significantly (psuccess of AVS is lower than reported elsewhere. Provided that effects on the LI are considered, the use of ACTH-stimulation during AVS assists in the identification of unilateral forms of PA. Copyright © 2013 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Composition and genesis of the Konevinsky gold deposit, Eastern Sayan, Russia

Science.gov (United States)

Damdinov, B. B.; Zhmodik, S. M.; Roshchektaev, P. A.; Damdinova, L. B.

2016-03-01

The Konevinsky gold deposit in southeast Eastern Sayan is distinguished from most known deposits in this region (Zun-Kholba, etc.) by the geological setting and composition of mineralization. To elucidate the cause of the peculiar mineralization, we have studied the composition, formation conditions, and origin of this deposit, which is related to the Ordovician granitoid pluton 445-441 Ma in age cut by intermediate and basic dikes spatially associated with metavolcanic rocks of the Devonian-Carboniferous Ilei Sequence. Four mineral assemblages are recognized: (1) quartz-pyrite-molybdenite, (2) quartz-gold-pyrite, (3) gold-polysulfide, and (4) telluride. Certain indications show that the ore was formed as a result of the superposition of two distinct mineral assemblages differing in age. The first stage dated at ~440 Ma is related to intrusions generating Cu-Mo-Au porphyry mineralization and gold-polysulfide veins. The second stage is controlled by dikes pertaining to the Devonian-Carboniferous volcanic-plutonic association. The second stage is characterized by gain of Hg and Te and formation of gold-mercury-telluride paragenesis.

Spider Vein Removal

Science.gov (United States)

Spider veins: How are they removed? I have spider veins on my legs. What options are available ... M.D. Several options are available to remove spider veins — thin red lines or weblike networks of ...

Conjugation of gold nanoparticles and recombinant human endostatin modulates vascular normalization via interruption of anterior gradient 2-mediated angiogenesis.

Science.gov (United States)

Pan, Fan; Yang, Wende; Li, Wei; Yang, Xiao-Yan; Liu, Shuhao; Li, Xin; Zhao, Xiaoxu; Ding, Hui; Qin, Li; Pan, Yunlong

2017-07-01

Several studies have revealed the potential of normalizing tumor vessels in anti-angiogenic treatment. Recombinant human endostatin is an anti-angiogenic agent which has been applied in clinical tumor treatment. Our previous research indicated that gold nanoparticles could be a nanoparticle carrier for recombinant human endostatin delivery. The recombinant human endostatin-gold nanoparticle conjugates normalized vessels, which improved chemotherapy. However, the mechanism of recombinant human endostatin-gold nanoparticle-induced vascular normalization has not been explored. Anterior gradient 2 has been reported to be over-expressed in many malignant tumors and involved in tumor angiogenesis. To date, the precise efficacy of recombinant human endostatin-gold nanoparticles on anterior gradient 2-mediated angiogenesis or anterior gradient 2-related signaling cohort remained unknown. In this study, we aimed to explore whether recombinant human endostatin-gold nanoparticles could normalize vessels in metastatic colorectal cancer xenografts, and we further elucidated whether recombinant human endostatin-gold nanoparticles could interrupt anterior gradient 2-induced angiogenesis. In vivo, it was indicated that recombinant human endostatin-gold nanoparticles increased pericyte expression while inhibit vascular endothelial growth factor receptor 2 and anterior gradient 2 expression in metastatic colorectal cancer xenografts. In vitro, we uncovered that recombinant human endostatin-gold nanoparticles reduced cell migration and tube formation induced by anterior gradient 2 in human umbilical vein endothelial cells. Treatment with recombinant human endostatin-gold nanoparticles attenuated anterior gradient 2-mediated activation of MMP2, cMyc, VE-cadherin, phosphorylation of p38, and extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) in human umbilical vein endothelial cells. Our findings demonstrated recombinant human endostatin-gold nanoparticles might normalize

Gold and other metals in big sagebrush (Artemisia tridentata Nutt.) as an exploration tool, Gold Run District, Humboldt County, Nevada

Science.gov (United States)

Erdman, J.A.; Cookro, T.M.; O'Leary, R. M.; Harms, T.F.

1988-01-01

Big sagebrush - a cold-desert species that dominates the terrain over large parts of western United States - was sampled along several traverses that crossed thermally metamorphosed limestone, phyllitic shale, and schist of the Middle and Upper Cambrian Preble Formation that host skarn-, disseminated gold and silver-, and hot springs gold-type mineral occurrences. Patterns of detectable levels of gold (8 to 28 ppb or ng g-1) in ash of new growth were consistent with areas affected by known or suspected gold mineralization. Soils collected along one of the traverses where a selenium-indicator plant was common contained no gold above background levels of 2ppb, but were consistently high in As, Sb, and Zn, and several samples were unusually high in Se (maximum 11 ppm or ??g g-1). Sagebrush along this traverse contained Li at levels above norms for this species. We also found a puzzling geochemical anomaly at a site basinward from active hot springs along a range-front fault scarp. Sagebrush at this site contained a trace of gold and an unusually high concentration of Cd (13 ppm) and the soil had anomalous concentrations of Cd and Bi (3.2 and 6 ppm, respectively). The source of this anomaly could be either metal-rich waters from an irrigation ditch or leakage along a buried fault. Despite the limited nature of the study, we conclude that gold in sagebrush could be a cost-effective guide to drilling locations in areas where the geology seems favorable for disseminated and vein precious metals. ?? 1988.

Stable Isotopes (O, H, and S) in the Muteh Gold Deposit, Golpaygan Area, Iran

International Nuclear Information System (INIS)

Abdollahi, M. J.; Karimpour, M. H.; Kheradmand, A.; Zarasvandi, A. R.

2009-01-01

The Muteh gold district with nine gold deposits is located in the Sanandaj-Sirjan metamorphic zone. Gold mineralization occurs in a pre-Permian complex which mainly consists of green schists, meta-volcanics, and gneiss rocks. Shear zones are the host of gold mineralization. Gold paragenesis minerals include pyrite, chalcopyrite, pyrrhotite, and secondary minerals. Pyrites occur as pre-, syn-, and post-metamorphism minerals. To determine the source of the ore-bearing fluids, fifty samples were selected for petrographical and stable isotope studies. The mean values of 12.4 per mille , and -42 per mille for δ 18 O and δD isotopes, respectively, and a mean value of 7.75 per mille of calculated fractionation factors for δ 18 O H 2 O, from quartz veins indicate that metamorphic host rocks are the most important source for the fluids and gold mineralization. Three generations of pyrite can be distinguished showing a wide range of δ 34 S. Gold mineralization is closely associated with intense hydrothermal alteration along the ductile shear zones. The characteristics of the gold mineralization in the study area are similar to those of orogenic gold deposits elsewhere

What Are Varicose Veins?

Science.gov (United States)

... Leer en español What Is Varicose (VAR-i-kos) veins are swollen, twisted veins that you can ... TA-ze-uhs), spider veins, varicoceles (VAR-i-ko-seals), and other vein problems. Telangiectasias Telangiectasias are ...

Adrenal Vein Sampling for Conn’s Syndrome: Diagnosis and Clinical Outcomes

Directory of Open Access Journals (Sweden)

Amy R. Deipolyi

2015-06-01

Full Text Available Adrenal vein sampling (AVS is the gold standard test to determine unilateral causes of primary aldosteronism (PA. We have retrospectively characterized our experience with AVS including concordance of AVS results and imaging, and describe the approach for the PA patient in whom bilateral AVS is unsuccessful. We reviewed the medical records of 85 patients with PA and compared patients who were treated medically and surgically on pre-procedure presentation and post-treatment outcomes, and evaluated how technically unsuccessful AVS results were used in further patient management. Out of the 92 AVS performed in 85 patients, AVS was technically successful bilaterally in 58 (63% of cases. Either unsuccessful AVS prompted a repeat AVS, or results from the contralateral side and from CT imaging were used to guide further therapy. Patients who were managed surgically with adrenalectomy had higher initial blood pressure and lower potassium levels compared with patients who were managed medically. Adrenalectomy results in significantly decreased blood pressure and normalization of potassium levels. AVS can identify surgically curable causes of PA, but can be technically challenging. When one adrenal vein fails to be cannulated, results from the contralateral vein can be useful in conjunction with imaging and clinical findings to suggest further management.

Varicose vein - noninvasive treatment

Science.gov (United States)

... spider veins. These are small varicose veins. Salt water (saline) or a chemical solution is injected into the varicose vein. The vein will harden and then disappear. Laser treatment can be used on the surface of the skin. Small bursts ...

Trace element mapping of pyrite from Archean gold deposits – A comparison between PIXE and EPMA

Energy Technology Data Exchange (ETDEWEB)

Agangi, A., E-mail: aagangi@uj.ac.za [University of Johannesburg, Department of Geology, Auckland Park 2006 (South Africa); Przybyłowicz, W., E-mail: przybylowicz@tlabs.ac.za [Materials Research Department, iThemba LABS, National Research Foundation, Somerset West 7129 (South Africa); AGH University of Science and Technology, Faculty of Physics & Applied Computer Science, Al. A. Mickiewicza 30, 30-059 Krakow (Poland); Hofmann, A., E-mail: ahofmann@uj.ac.za [University of Johannesburg, Department of Geology, Auckland Park 2006 (South Africa)

2015-04-01

Chemical zoning of pyrites can record the evolution of mineralising fluids at widely varying P–T conditions ranging from diagenesis to medium-grade metamorphism. If preserved, zoning can reveal growth textures, brecciation and veining, resorption and recrystallisation events, thus shedding light on the processes that contributed to ore formation. Chemical zoning of sulfides is invisible in optical microscopy, but can be studied by chemical etching, high-contrast back-scattering electron images, and elemental imaging. In this study we compared micro-PIXE and WDS-EPMA elemental maps on the chemically zoned pyrites in mineralised vein-bearing samples from the Sheba and Fairview gold mines in the Barberton Greenstone Belt, South Africa. Elemental images show complex distribution of trace elements, suggesting multiple events of pyrite crystallisation and gold deposition. EPMA maps show fine-scale variations reflecting growth and recrystallisation textures marked, in particular, by variations of As, Ni, and Co. In PIXE maps, gold occurs both as finely-distributed and discrete inclusions, suggesting incorporation in the pyrite structure as solid solution, and deposition as electrum inclusions, respectively. Micro-PIXE and EPMA provide complementary information, forming together a powerful tool to obtain information on chemical zoning of pyrites in ore deposits.

Ligation of superior mesenteric vein and portal to splenic vein anastomosis after superior mesenteric-portal vein confluence resection during pancreaticoduodenectomy - Case report.

Science.gov (United States)

Tang, Jianlin; Abbas, Jihad; Hoetzl, Katherine; Allison, David; Osman, Mahamed; Williams, Mallory; Zelenock, Gerald B

2014-12-01

62 year old Caucasian female with pancreatic head mass abutting the superior mesenteric vein (SMV) presented with fine needle aspiration biopsy confirmed diagnosis of ductal adenocarcinoma. CT scan showed near complete obstruction of portal vein and large SMV collateral development. After 3 months of neoadjuvant therapy, her portal vein flow improved significantly, SMV collateral circulation was diminished. Pancreaticoduodenectomy (PD) and superior mesenteric portal vein (SMPV) confluence resection were performed; A saphenous vein interposition graft thrombosed immediately. The splenic vein remnant was distended and adjacent to the stump of the portal vein. Harvesting an internal jugular vein graft required extra time and using a synthetic graft posed a risk of graft thrombosis or infection. As a result, we chose to perform a direct anastomosis of the portal and splenic vein in a desperate situation. The anastomosis decompressed the mesenteric venous system, so we then ligated the SMV. The patient had an uneventful postoperative course, except transient ascites. She redeveloped ascites more than one year later. At that time a PET scan showed bilateral lung and right femur metastatic disease. She expired 15 months after PD. The lessons we learned are (1) Before SMPV confluence resection, internal jugular vein graft should be ready for reconstruction. (2) Synthetic graft is an alternative for internal jugular vein graft. (3) Direct portal vein to SMV anastomosis can be achieved by mobilizing liver. (4) It is possible that venous collaterals secondary to SMV tumor obstruction may have allowed this patient's post-operative survival.

Raman and micro-thermometric investigation of the fluid inclusions in quartz in a gold-rich formation from Lepaguare mining district (Honduras, Central America).

Science.gov (United States)

Bersani, D; Salvioli-Mariani, E; Mattioli, M; Menichetti, M; Lottici, P P

2009-08-01

Fluid inclusions in the quartz crystals present in gold-rich veins from central Honduras have been studied by means of micro-thermometry and micro-Raman spectroscopy in order to provide information on the physico-chemical conditions and chemical composition of the mineralizing fluids. The use of a confocal micro-Raman apparatus allowed to obtain information on the fluid composition, in particular on the gas phase, minimizing the contributions of the host matrix to the Raman signal. The samples studied were collected from an area (Lepaguare mining district, Northern-Central Honduras) rich in ore deposits due to the Cenozoic magmatic activity, where the gold and sulphide mineralization is connected with a system of quartz veins (few decimetres thick) occurring in low-grade metamorphic rocks and produced by hydrothermal fluids. The quartz crystals present in the gold-rich veins often contain fluid inclusions. Four types of fluid inclusions have been observed, but their assemblage in the same clusters and fracture systems, as well as their comparable salinity and homogenization data, suggest that they have the same origin. Micro-thermometry and Raman spectroscopy provide a composition of the mineralizing fluids attributable to the system H(2)O-NaCl-KCl-CO(2)-CH(4), with temperature and pressure intervals of 210-413 degrees C and 1050-3850 bar, respectively. These data agree with an epigenetic origin of the gold deposit (depth < 6 km) related to granitoid or granodiorite intrusions associated to orogenic environments.

Trace elements and isotope data of the Um Garayat gold deposit, Wadi Allaqi district, Egypt

Science.gov (United States)

Zoheir, Basem; Emam, Ashraf; Pitcairn, Iain K.; Boskabadi, Arman; Lehaye, Yann; Cooper, Matthew J.

2018-04-01

Trace element composition of sulfides and O, C, Sr and S isotopic data are assessed to constrain the evolution and potential fluid and metal sources of the Um Garayat gold deposit. Ore microscopy and BSE investigations of quartz veins show blocky arsenopyrite and pyrite replaced in part by pyrrhotite, chalcopyrite, sphalerite, galena, and gersdorffite. Free-milling gold occurs commonly in close association with the late sulfides, and along fractures in pyrite. On the other hand, recrystallized pyrite is disseminated in host metavolcaniclastic/metasedimentary rocks that commonly contain carbonaceous material. In situ LA-ICP-MS analysis of sulfides shows the recrystallized pyrite enriched in most trace elements, while blocky pyrite contains only some traces of arsenic. Detected concentrations of gold (up to 17 ppm) were only reported in arsenopyrite disseminated in quartz veins. The δ34S values of blocky pyrite and pyrrhotite in quartz veins define a narrow range (1.6 to 3.7‰), suggesting a homogenous sulfur source which is consistent with the dominantly mafic host rocks. The recrystallized pyrite has a distinctive sulfur isotope composition (δ34S - 9.3 to - 10.6‰), which is rather comparable to diagenetic sulfides. Hydrothermal carbonate in quartz veins and wallrock have nearly constant values of δ18O (10.5 to 11.9‰) and δ13C (- 4.2 to - 5.5‰). Based on constraints from mineral assemblages and chlorite thermometry, data of six samples indicate that carbonate precipitation occurred at 280 °C from a homogenous hydrothermal fluid with δ18OH2O 4.4 ± 0.7‰ and δ13C = 3.7 ± 0.8‰. Strontium isotope values of two samples (87Sr/86Sr = 0.7024 and 0.7025) are similar to the initial 87Sr/86Sr ratios of island arc metabasalts ( 710 Ma) in the South Eastern Desert. The generally homogenous sulfur, C, O, Sr isotope data are suggestive of metamorphogenic fluids, likely produced from dominantly mafic volcanic rocks at the greenschist-amphibolite facies transition.

Accessory hepatic vein: MR imaging

International Nuclear Information System (INIS)

Lee, Chang Hee; Rho, Tack Soo; Cha, Sang Hoon; Park, Cheol Min; Cha, In Ho

1995-01-01

To evaluate the MR appearance of the accessory hepatic veins. The study included 87 consecutive patients for whom abdominal MR images were obtained. The subjects who had liver lesion or hepatic vascular abnormalities were excluded. Couinaud classified accessory hepatic veins into inferior and middle right hepatic veins. Our major interests were evaluation of the incidence, morphology, and location of the accessory hepatic vein. Inferior right hepatic vein was demonstrated in 43 out of 87 patients (49%). The morphology was linear in 35 patients (80.5%), and V-shaped in 8 patients (19.5%). In 40 patients (93%), the inferior right hepatic vein was located in the posteroinferior aspect of the right lobe. Middle right hepatic vein was demonstrated in 7 out of 87 patients (8%). All were single linear in morphology, combined with the inferior right hepatic vein, and located between the right hepatic vein and inferior right hepatic vein. The accessory hepatic vein was demonstrated in 49% among the Korean adult population, and was located in posteroinferior portion of the liver, in 93%

Ligation of superior mesenteric vein and portal to splenic vein anastomosis after superior mesenteric-portal vein confluence resection during pancreaticoduodenectomy – Case report

Science.gov (United States)

Tang, Jianlin; Abbas, Jihad; Hoetzl, Katherine; Allison, David; Osman, Mahamed; Williams, Mallory; Zelenock, Gerald B.

2014-01-01

62 year old Caucasian female with pancreatic head mass abutting the superior mesenteric vein (SMV) presented with fine needle aspiration biopsy confirmed diagnosis of ductal adenocarcinoma. CT scan showed near complete obstruction of portal vein and large SMV collateral development. After 3 months of neoadjuvant therapy, her portal vein flow improved significantly, SMV collateral circulation was diminished. Pancreaticoduodenectomy (PD) and superior mesenteric portal vein (SMPV) confluence resection were performed; A saphenous vein interposition graft thrombosed immediately. The splenic vein remnant was distended and adjacent to the stump of the portal vein. Harvesting an internal jugular vein graft required extra time and using a synthetic graft posed a risk of graft thrombosis or infection. As a result, we chose to perform a direct anastomosis of the portal and splenic vein in a desperate situation. The anastomosis decompressed the mesenteric venous system, so we then ligated the SMV. The patient had an uneventful postoperative course, except transient ascites. She redeveloped ascites more than one year later. At that time a PET scan showed bilateral lung and right femur metastatic disease. She expired 15 months after PD. Conclusion The lessons we learned are (1) Before SMPV confluence resection, internal jugular vein graft should be ready for reconstruction. (2) Synthetic graft is an alternative for internal jugular vein graft. (3) Direct portal vein to SMV anastomosis can be achieved by mobilizing liver. (4) It is possible that venous collaterals secondary to SMV tumor obstruction may have allowed this patient's post-operative survival. PMID:25568802

Varicose Veins - Multiple Languages

Science.gov (United States)

... Concerns and Discomforts of Pregnancy: Varicose Veins - English MP3 Concerns and Discomforts of Pregnancy: Varicose Veins - 简体中文 (Chinese, Simplified (Mandarin dialect)) MP3 Concerns and Discomforts of Pregnancy: Varicose Veins - English ...

Metallogeny of the Gold Quadrilateral: style and characteristics of epithermal - subvolcanic mineralized structures, South Apuseni Mts., Romania

Directory of Open Access Journals (Sweden)

S̡erban-Nicolae Vlad

2004-04-01

Full Text Available The Romanian territory contains numerous ore deposits mined since pre-Roman times. An assessment of historical gold production of the Gold Quadri-lateral (GQ yielded a total estimate of 55.7 Moz of gold throughout an area of 2400 km2. Interpreted in terms of mineralization density this is 23,208 oz of gold/ km2. The geological setting of the GQ is represented mainly by Tertiary (14.7 My to 7.4 My calc-alkaline volcano-plutonic complexes of intermediate character in sedimentary basins of molasse type. These basins are tectonically controlled by NW-SE lineation across early Alpine magmatic products, i.e. subduction related Jurassic-Lower Cretaceous igneous association (island arc ophiolites and granitoids and Upper Cretaceous igneous association (banatites. The Tertiary magmatism is associated with extensional tectonics caused by NE escape of the Pannonian region during Upper Oligocene-Lower Miocene times. As a result of tectono-magmatic and mineralization-alteration characteristics, two metallogenetical types were separated in the GQ, i.e. calc-alkaline andesitic (CAM and sub-alkaline rhyodacitic (SRM. Both develop almost entirely low-sulfidation type of Au epithermal mineralization. However, two subtypes, -rich in sulfide (2-7% and -poor in sulfide (7-20% were delineated and correlated with CAM type and SRM type respectively. Furthermore, CAM is connected at deeper levels with Cu-Au+/-Mo porphyry systems in contrast with SRM, which is a non-porphyry environment. The Brad-Săcărâmb district contains mainly CAM type andesitic structures. It is a porphyry environment with epithermal low-sulfidation-rich sulfide vein halo (Barza, Troiţa-Bolcana deposits. However, a few SRM type patterns, such as Măgura Ţebii, Băiţa-Crăciuneşti and Săcărâmb, deposits exhibit Au-Ag-Te low-sulfidation-poor sulfide epithermal vein halo. The Zlatna-Stănija district exhibits similar characteristics, with Au-Ag+/-Pb, Zn veins in Cu-Au subvolcanic

Valsalva and gravitational variability of the internal jugular vein and common femoral vein: Ultrasound assessment

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Beddy, P. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland)]. E-mail: pbeddy@eircom.net; Geoghegan, T. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Ramesh, N. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Buckley, O. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); O' Brien, J. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Colville, J. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Torreggiani, W.C. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland)

2006-05-15

Purpose: Central venous cannulation via the common femoral vein is an important starting point for many interventions. The purpose of this study was to determine the optimum conditions for cannulation of the femoral vein and to compare these with the relative changes in the internal jugular vein. Methods: High-resolution 2D ultrasound was utilised to determine variability of the calibre of the femoral and internal jugular veins in 10 healthy subjects. Venous diameter was assessed during the Valsalva manoeuvre and in different degrees of the Trendelenburg position. Results: The Valsalva manoeuvre significantly increased the size of the femoral and internal jugular veins. There was a relatively greater increase in femoral vein diameter when compared with the internal jugular vein of 40 and 29%, respectively. Changes in body inclination (Trendelenburg position) did not significantly alter the luminal diameter of the femoral vein. However, it significantly increased internal jugular vein diameter. Conclusions: Femoral vein cannulation is augmented by the Valsalva manoeuvre but not significantly altered by the gravitational position of the subject.

CT findings of portal vein aneurysm

International Nuclear Information System (INIS)

Yang, Dal Mo; Chang, Mi Son; Yoon, Myung Hwan; Kim, Hak Soo; Kim, Hyung Sik; Chung, Hyo Sun; Chung, Jin Woo

1999-01-01

To describe the CT findings of portal vein aneurysm in eight patients. All patients included in this study (two men and six women) underwent CT examinations between October 1996 and June1998. Of these eight, three were suffering from hepatic disease and portal hypertension. We determined the location, shape, size, and characteristics of the lesions, and the presence or absence of portal vein anomaly. Seven patients had intrahepatic portal vein aneurysm (at the umbilical portion of the left portal vein in five patients, between the transverse and umbilical portion of the left portal vein in one, and at the bifurcation of the anterior and posterior branch of the right portal vein in one), while extrahepatic portal vein aneurysm, at the confluence of the superior mesenteric and splenic vein was found in only one. Lesions were cyst-shaped in seven cases and saccular in one, and showed well-circumscribed, markedly enhanced mass, which communicated with the portal vein and/or gives off major branches. Portal vein anomaly, in which the right anterior segmental portal vein originated from the umbilical portion of the left portal vein, was seen in three patients. In all three, intrahepatic portal vein aneurysm was present at the umbilical portion of the left portal vein, and in one, the umbilical protion of the left portal vein was located to the right of the Cantlic line. CT examination can help reveal portal vein aneurysm by detecting a well-circumscribed, markedly enhanced mass which communicates with the portal vein and/or gives off major branches

Major Brazilian gold deposits - 1982 to 1999

Science.gov (United States)

Thorman, Charles H.; DeWitt, Ed; Maron, Marcos A.; Ladeira, Eduardo A.

2001-07-01

Brazil has been a major but intermittent producer of gold since its discovery in 1500. Brazil led the world in gold production during the 18th and early 19th centuries. From the late 19th century to the late 20th century, total mining company and garimpeiro production was small and relatively constant at about 5 to 8 t/year. The discovery of alluvial deposits in the Amazon by garimpeiros in the 1970s and the opening of eight mines by mining companies from 1983 to 1990 fueled a major boom in Brazil's gold production, exceeding 100 t/year in 1988 and 1989. However, garimpeiro alluvial production decreased rapidly in the 1990s, to about 10 t/year by 1999. Company production increased about tenfold from about 4 t/year in 1982 to 40 t in 1992. Production from 1992 to the present remained relatively stable, even though several mines were closed or were in the process of closing and no new major mines were put into production during that period. Based on their production history from 1982-1999, 17 gold mines are ranked as major (>20 t) and minor (3-8 t) mines. From 1982-1999, deposits hosted in Archean rocks produced 66% of the gold in Brazil, whereas deposits in Paleoproterozoic and Neoproterozoic rocks accounted for 19% and 15%, respectively. Deposits in metamorphosed sedimentary rocks, especially carbonate-rich rocks and carbonate iron-formation, yielded the great bulk of the gold. Deposits in igneous rocks were of much less importance. The Archean and Paleoproterozoic terranes of Brazil largely lack base-metal-rich volcanogenic massive sulfide deposits, porphyry deposits, and polymetallic veins and sedimentary exhalative deposits. An exception to this is in the Carajás Mineral Province.

Major brazilian gold deposits - 1982 to 1999

Science.gov (United States)

Thorman, C.H.; Dewitt, E.; Maron, M.A.; Ladeira, E.A.

2001-01-01

Brazil has been a major but intermittent producer of gold since its discovery in 1500. Brazil led the world in gold production during the 18th and early 19th centuries. From the late 19th century to the late 20th century, total mining company and garimpeiro production was small and relatively constant at about 5 to 8 t/year. The discovery of alluvial deposits in the Amazon by garimpeiros in the 1970s and the opening of eight mines by mining companies from 1983 to 1990 fueled a major boom in Brazil's gold production, exceeding 100 t/year in 1988 and 1989. However, garimpeiro alluvial production decreased 'rapidly in the 1990s, to about 10 t/year by 1999. Company production increased about tenfold from about 4 t/year in 1982 to 40 t in 1992. Production from 1992 to the present remained relatively stable, even though several mines were closed or were in the process of closing and no new major mines were put into production during that period. Based on their production history from 1982-1999, 17 gold mines are ranked as major (> 20 t) and minor (3-8 t) mines. From 1982-1999, deposits hosted in Archean rocks produced 66% of the gold in Brazil, whereas deposits in Paleoproterozoic and Neoproterozoic rocks accounted for 19% and 15%, respectively. Deposits in metamorphosed sedimentary rocks, especially carbonate-rich rocks and carbonate iron-formation, yielded the great bulk of the gold. Deposits in igneous rocks were of much less importance. The Archean and Paleoproterozoic terranes of Brazil largely lack base-metal-rich volcanogenic massive sulfide deposits, porphyry deposits, and polymetallic veins and sedimentary exhalative deposits. An exception to this is in the Caraja??s Mineral Province.

Are modern geothermal waters in northwest Nevada forming epithermal gold deposits?

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Breit, George N.; Hunt, Andrew G.; Wolf, Ruth E.; Koenig, Alan E.; Fifarek, Richard; Coolbaugh, Mark F.

2010-01-01

Hydrothermal systems currently are active near some gold deposits in northwestern Nevada. Possible links of these modern systems to gold mineralization were evaluated by chemically and isotopically analyzing water samples from the Brady, Dixie Valley, Humboldt House, San Emidio-Empire, Soda Lake, and Wabuska geothermal areas. In addition, quartz veins from Humboldt House and the adjacent Florida Canyon Mine were analyzed to compare ore and gangue phases with those predicted to form from proximal hydrothermal fluids.Nearly all water samples are alkali-chloride-type. Total dissolved solids range from 800 to 3900 mg/L, and pH varies from 5.6 to 7.8. Geochemical modeling with SOLVEQ, WATCH, and CHILLER predict the precipitation of silica in all systems during cooling. Anhydrite, calcite, barite, pyrite, base-metal sulfides, and alumino-silicates are variably saturated at calculated reservoir temperatures and also precipitate during boiling/cooling of some fluids. Measured dissolved gold concentrations are low (<0.2μg/L), but are generally consistent with contents predicted by equilibrium of sampled solutions with elemental gold at reservoir temperatures.  Although the modern geothermal waters can precipitate ore minerals, the low gold and other ore metal concentrations require very large fluid volumes to form a deposit of economic interest.

Comparison between mechanical properties of human saphenous vein and umbilical vein

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Hamedani Borhan

2012-08-01

Full Text Available Abstract Background As a main cause of mortality in developed countries, Coronary Artery Disease (CAD is known as silent killer with a considerable cost to be dedicated for its treatment. Coronary Artery Bypass Graft (CABG is a common remedy for CAD for which different blood vessels are used as a detour. There is a lack of knowledge about mechanical properties of human blood vessels used for CABG, and while these properties have a great impact on long-term patency of a CABG. Thus, studying these properties, especially those of human umbilical veins which have not been considered yet, looks utterly necessary. Methods Umbilical vein, as well as human Saphenous vein, are respectively obtained after cesarean and CABG. First, histological tests were performed to investigate different fiber contents of the samples. Having prepared samples carefully, force-displacement results of samples were rendered to real stress–strain measurements and then a fourth-order polynomial was used to prove the non-linear behavior of these two vessels. Results Results were analyzed in two directions, i.e. circumferentially and longitudinally, which then were compared with each other. The comparison between stiffness and elasticity of these veins showed that Saphenous vein’s stiffness is much higher than that of umbilical vein and also, it is less stretchable. Furthermore, for both vessels, longitudinal stiffness was higher than that of circumferential and in stark contrast, stretch ratio in circumferential direction came much higher than longitudinal orientation. Conclusion Blood pressure is very high in the region of aorta, so there should be a stiff blood vessel in this area and previous investigations showed that stiffer vessels would have a better influence on the flow of bypass. To this end, the current study has made an attempt to compare these two blood vessels’ stiffness, finding that Saphenous vein is stiffer than umbilical vein which is somehow as stiff as

Vein grafting in fingertip replantations.

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Yan, Hede; Jackson, William D; Songcharoen, Somjade; Akdemir, Ovunc; Li, Zhijie; Chen, Xinglong; Jiang, Liangfu; Gao, Weiyang

2009-01-01

In this retrospective study, the survival rates of fingertip replantation with and without vein grafting were evaluated along with their postoperative functional and cosmetic results. One hundred twenty-one-fingertip amputations were performed in 103 patients between September 2002 and July 2007. Thirty-four amputated fingertips were replanted without vein grafting, while 87 amputated fingertips were replanted with vein grafting for arterial and/or venous repairs. The overall survival rates of the replantations with and without vein grafting were 90% (78/87) and 85% (29/34), respectively. The survival rates were 88% (36/41) with venous repair, 93% (25/27) with arterial repair, and 89% (17/19) with both. Nineteen patients without vein grafting and 48 patients with vein grafting had a follow-up period of more than one year. Good cosmetic and functional outcomes were observed in both groups of patients. The results show that vein grafting is a reliable technique in fingertip replantations, showing no significant difference (P > 0.05) in survival between those with and without vein grafting. Furthermore, no significant difference (P > 0.05) in survival was found between cases with vein grafts for arterial and/or venous repairs. In fingertip replantations with vein grafting, favorable functional and esthetic results can be achieved without sacrificing replantation survival. (c) 2009 Wiley-Liss, Inc.

The Kharapeh orogenic gold deposit: Geological, structural, and geochemical controls on epizonal ore formation in West Azerbaijan Province, Northwestern Iran

Science.gov (United States)

Niroomand, Shojaeddin; Goldfarb, Richard J.; Moore, Farib; Mohajjel, Mohammad; Marsh, Erin E.

2011-01-01

The Kharapeh gold deposit is located along the northwestern margin of the Sanandaj–Sirjan Zone (SSZ) in the West Azerbaijan province, Iran. It is an epizonal orogenic gold deposit formed within the deformed zone between central Iran and the Arabian plate during the Cretaceous–Tertiary Zagros orogeny. The deposit area is underlain by Cretaceous schist and marble, as well as altered andesite and dacite dikes. Structural analysis indicates that the rocks underwent tight to isoclinal recumbent folding and were subsequently co-axially refolded to upright open folds during a second deformation. Late- to post-tectonic Cenozoic granites and granodiorites occur northeast of the deposit area. Mineralization mainly is recognized within NW-trending extensional structures as veins and breccia zones. Normal faults, intermediate dikes, and quartz veins, oriented subparallel to the axial surface of the Kharapeh antiform, indicate synchronous extension perpendicular to the fold axis during the second folding event. The gold-bearing quartz veins are >1 km in length and average about 6 m in width; breccia zones are 10–50 m in length and ≤1 m in width. Hydrothermal alteration mainly consists of silicification, sulfidation, chloritization, sericitization, and carbonatization. Paragenetic relationships indicate three distinct stages—replacement and silicification, brecciation and fracture filling, and cataclastic brecciation—with the latter two being gold-rich. Fluid inclusion data suggest mineral deposition at temperatures of at least 220–255°C and depths of at least 1.4–1.8 km, from a H2O–CO2±CH4 fluid of relatively high salinity (12–14 wt.% NaCl equiv.), which may reflect metamorphism of passive margin carbonate sequences. Ore fluid δ18O values between about 7‰ and 9‰ suggest no significant meteoric water input, despite gold deposition in a relatively shallow epizonal environment. Similarities to other deposits in the SSZ suggest that the deposit formed as

Vein matching using artificial neural network in vein authentication systems

Science.gov (United States)

Noori Hoshyar, Azadeh; Sulaiman, Riza

2011-10-01

Personal identification technology as security systems is developing rapidly. Traditional authentication modes like key; password; card are not safe enough because they could be stolen or easily forgotten. Biometric as developed technology has been applied to a wide range of systems. According to different researchers, vein biometric is a good candidate among other biometric traits such as fingerprint, hand geometry, voice, DNA and etc for authentication systems. Vein authentication systems can be designed by different methodologies. All the methodologies consist of matching stage which is too important for final verification of the system. Neural Network is an effective methodology for matching and recognizing individuals in authentication systems. Therefore, this paper explains and implements the Neural Network methodology for finger vein authentication system. Neural Network is trained in Matlab to match the vein features of authentication system. The Network simulation shows the quality of matching as 95% which is a good performance for authentication system matching.

Stable isotope and fluid inclusion signatures of hydrothermal fluids in transcrustal fault zones: significance for orogenic, Archean lode-gold mineralization

International Nuclear Information System (INIS)

Neumayr, P.; Hagemann, S.G.; Groves, D.I.

1999-01-01

Full text: Large to giant (>1t) gold deposits are typically hosted in second- and third-order structures adjacent to largely barren, transcrustal fault zones. Gold-bearing hydrothermal fluids have been channelled within the transcrustal fault zones from mantle and deep crustal sources into the second- and third-order structures, where gold has been deposited. Transcrustal fault zones are long-lived structures with specific deformation events relating to gold deposition in the second- and third-order structures. For example the Archaean Perseverance Fault in the Yilgarn Craton of Western Australia evolved from a wide (5km) ductile shear zone during D2 to a narrow ( 2 -CH 4 -dominated compositions with minor H 2 O and H 2 S components, whereas there are H 2 O-dominated H 2 O-CO 2 +CH 4 fluids with a significant H 2 S component in the second- and third-order shear zones at the Sigma gold deposit, a major gold deposit 5km to the north of the CTZ. These differences can be explained by continuous phase separation, with CO 2 -vapour escape into the upper portions of the ductile uncapped CTZ, contrasting with in-situ phase separation of the gold-bearing fluids in crack-seal veins in the second-order shear zones at Sigma, with trapping of both the episodic vapour and liquid components in individual sealed veins. Gold mineralization in the second- and third-order structures appears to be controlled by the high H 2 S activity of the aqueous hydrothermal fluids. because gold was likely carried in a bisulphide complex and was deposited during sulfidation reactions in the wallrock and phase separation in the quartz vein. In contrast, the carbonic fluids in the CTZ lacked the ability to carry significant metal ligands due to their low H 2 S activity. Oxygen isotopes from hydrothermal quartz within the CTZ (13.3 to 15.6 per mil, av. 14.0 per mil; VSMOW) are heavier than those from mineralized quartz veins in second- and third-order shear zones (11.8 to 19.6 per mil, av. 12.2 per

Absence of Middle Hepatic Vein Combined with Retro-Aortic Left Renal Vein: a Very Rare Case Report

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Sezer Akçer

2012-06-01

Full Text Available The hepatic and renal veins drain into the inferior vena cava. The upper group of hepatic veins consists of three veins which extend to the posterior face of the liver to join the inferior cava. The left renal vein passes anterior to the aorta just below the origin of the superior mesenteric artery. We detected a variation in the hepatic and renal veins in a multislice CT angiogram of a nine-year-old male patient in the Radiology Department of Afyon Kocatepe University Medical School. The upper group hepatic veins normally drains into the inferior vena cava as three separate trunks, namely the right, left and middle. In our case, we found that only the right and left hepatic veins existed and the middle hepatic vein was absent. Furthermore, the left renal vein, which normally passes anterior to the abdominal aorta, was retro-aortic. Left renal vein variations are of great importance in planning retroperitoneal surgery and vascular interventions. Knowledge of a patient’s hepatic vein and renovascular anatomy and determining their variations and anomalies are of critical importance to abdominal operations, transplantations and preoperative evaluation of endovascular interventions.

Surgical Access to Jejunal Veins for Local Thrombolysis and Stent Placement in Portal Vein Thrombosis

International Nuclear Information System (INIS)

Schellhammer, Frank; Esch, Jan Schulte am; Hammerschlag, Sascha; Knoefel, Wolfram Trudo; Fuerst, Guenter

2008-01-01

Portal vein thrombosis is an infrequent entity, which may cause high morbidity and mortality. We report a case of portal vein thrombosis due to benign stenosis following partial pancreatoduodenectomy with segmental replacement of the portal vein by a Gore-tex graft. Using a surgical access to jenunal veins, local thrombolysis, mechanical fragmentation of thrombus, and stent placement were successfully performed.

Uptake of gold nanoparticles in primary human endothelial cells

DEFF Research Database (Denmark)

Klingberg, Henrik; Oddershede, Lene B.; Löschner, Katrin

2015-01-01

Gold nanoparticles (AuNPs) are relevant in nanomedicine for drug delivery in the vascular system, where endothelial cells are the first point of contact. We investigated the uptake of 80 nm AuNPs in primary human umbilical vein endothelial cells (HUVECs) by flow cytometry, 3D confocal microscopy......–3 or more particles. Pre-treatment with chlorpromazine inhibited the AuNP-uptake in HUVECs, indicating that internalisation occurred mainly by clathrin-mediated endocytosis. Cell activation by exposure to tumour necrosis factor or lipopolysaccharide had a slight or no effect on the uptake of Au...

The economics of vein disease.

Science.gov (United States)

Sales, Clifford M; Podnos, Joan; Levison, Jonathan

2007-09-01

The management of cosmetic vein problems requires a very different approach than that for the majority of most other vascular disorders that occur in a vascular surgery practice. This article focuses on the business aspects of a cosmetic vein practice, with particular attention to the uniqueness of these issues. Managing patient expectations is critical to the success of a cosmetic vein practice. Maneuvering within the insurance can be difficult and frustrating for both the patient and the practice. Practices should use cost accounting principles to evaluate the success of their vein work. Vein surgery--especially if performed within the office--can undergo an accurate break-even analysis to determine its profitability.

Deep Vein Thrombosis

African Journals Online (AJOL)

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Deep Vein Thrombosis: Risk Factors and Prevention in Surgical Patients. Deep Vein ... preventable morbidity and mortality in hospitalized surgical patients. ... the elderly.3,4 It is very rare before the age ... depends on the risk level; therefore an .... but also in the post-operative period. ... is continuing uncertainty regarding.

Automated detection and classification of major retinal vessels for determination of diameter ratio of arteries and veins

Science.gov (United States)

Muramatsu, Chisako; Hatanaka, Yuji; Iwase, Tatsuhiko; Hara, Takeshi; Fujita, Hiroshi

2010-03-01

Abnormalities of retinal vasculatures can indicate health conditions in the body, such as the high blood pressure and diabetes. Providing automatically determined width ratio of arteries and veins (A/V ratio) on retinal fundus images may help physicians in the diagnosis of hypertensive retinopathy, which may cause blindness. The purpose of this study was to detect major retinal vessels and classify them into arteries and veins for the determination of A/V ratio. Images used in this study were obtained from DRIVE database, which consists of 20 cases each for training and testing vessel detection algorithms. Starting with the reference standard of vasculature segmentation provided in the database, major arteries and veins each in the upper and lower temporal regions were manually selected for establishing the gold standard. We applied the black top-hat transformation and double-ring filter to detect retinal blood vessels. From the extracted vessels, large vessels extending from the optic disc to temporal regions were selected as target vessels for calculation of A/V ratio. Image features were extracted from the vessel segments from quarter-disc to one disc diameter from the edge of optic discs. The target segments in the training cases were classified into arteries and veins by using the linear discriminant analysis, and the selected parameters were applied to those in the test cases. Out of 40 pairs, 30 pairs (75%) of arteries and veins in the 20 test cases were correctly classified. The result can be used for the automated calculation of A/V ratio.

C-Arm Computed Tomography-Assisted Adrenal Venous Sampling Improved Right Adrenal Vein Cannulation and Sampling Quality in Primary Aldosteronism.

Science.gov (United States)

Park, Chung Hyun; Hong, Namki; Han, Kichang; Kang, Sang Wook; Lee, Cho Rok; Park, Sungha; Rhee, Yumie

2018-05-04

Adrenal venous sampling (AVS) is a gold standard for subtype classification of primary aldosteronism (PA). However, this procedure has a high failure rate because of the anatomical difficulties in accessing the right adrenal vein. We investigated whether C-arm computed tomography-assisted AVS (C-AVS) could improve the success rate of adrenal sampling. A total of 156 patients, diagnosed with PA who underwent AVS from May 2004 through April 2017, were included. Based on the medical records, we retrospectively compared the overall, left, and right catheterization success rates of adrenal veins during the periods without C-AVS (2004 to 2010, n=32) and with C-AVS (2011 to 2016, n=134). The primary outcome was adequate bilateral sampling defined as a selectivity index (SI) >5. With C-AVS, the rates of adequate bilateral AVS increased from 40.6% to 88.7% (PAVS was an independent predictor of adequate bilateral sampling in the multivariate model (odds ratio, 9.01; PAVS improved the overall success rate of AVS, possibly as a result of better catheterization of right adrenal vein. Copyright © 2018 Korean Endocrine Society.

Arabidopsis thaliana Ei-5: Minor Vein Architecture Adjustment Compensates for Low Vein Density in Support of Photosynthesis.

Science.gov (United States)

Stewart, Jared J; Polutchko, Stephanie K; Demmig-Adams, Barbara; Adams, William W

2018-01-01

An Arabidopsis thaliana accession with naturally low vein density, Eifel-5 (Ei-5), was compared to Columbia-0 (Col-0) with respect to rosette growth, foliar vein architecture, photosynthesis, and transpiration. In addition to having to a lower vein density, Ei-5 grew more slowly, with significantly lower rates of rosette expansion, but had similar capacities for photosynthetic oxygen evolution on a leaf area basis compared to Col-0. The individual foliar minor veins were larger in Ei-5, with a greater number of vascular cells per vein, compared to Col-0. This compensation for low vein density resulted in similar values for the product of vein density × phloem cell number per minor vein in Ei-5 and Col-0, which suggests a similar capacity for foliar sugar export to support similar photosynthetic capacities per unit leaf area. In contrast, the product of vein density × xylem cell number per minor vein was significantly greater in Ei-5 compared to Col-0, and was associated not only with a higher ratio of water-transporting tracheary elements versus sugar-transporting sieve elements but also significantly higher foliar transpiration rates per leaf area in Ei-5. In contrast, previous studies in other systems had reported higher ratios of tracheary to sieve elements and higher transpiration rate to be associated with higher - rather than lower - vein densities. The Ei-5 accession thus further underscores the plasticity of the foliar vasculature by illustrating an example where a higher ratio of tracheary to sieve elements is associated with a lower vein density. Establishment of the Ei-5 accession, with a low vein density but an apparent overcapacity for water flux through the foliar xylem network, may have been facilitated by a higher level of precipitation in its habitat of origin compared to that of the Col-0 accession.

Mineralization and trace element distribution in pyrite using EMPA in exploration drill holes from Cheshmeh Zard gold district, Khorasan Razavi Province, Iran

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Zahra Alaminia

2015-10-01

Full Text Available Introduction Pyrite is the most abundant sulfide mineral in low sulfidation ore deposits. Experimental studies have shown that low-temperature ( 200°C from hydrothermal or metamorphic fluids (Butler and Rickard, 2000. Framboidal pyrite mostly occurs in sedimentary environments, though it could also form during metamorphism and hydrothermal alteration (Scott et al., 2009. The pyrite formed tends to be enriched in various trace elements such as Au and As. For this study we have combined the geology, alteration, mineralization with recent studies of the description of the deposit from core logging and underground mapping and geochemistry in the CheshmehZard gold district and also investigated the compositional variation and textural differences between pyrite types. This study is based on the results of our alteration and mineralization mapping and detailed logging of 1937.8 m of drill core. Materials and Methods Geology, hydrothermal alteration and mineralization were examined in drill holes along several cross sections. Host-rock alteration minerals and veins were determined for 11 samples using standard X-ray diffraction (XRD and X-ray fluorescence spectrometry (XRF techniques. Polished sections were studied by reflected light microscopy and backscattered electron images (BSE. In this study, the trace-element composition of pyrite samples from the Au-III vein system was obtained using electron microprobe analyzer (EMPA data. All analyseswere carried out at the department of Materials Engineering and Physics of the University of Salzburg in Austria. The EMPA measurements and BSE imaging were made using a JXA-8600 electron microprobe. Spot analyses of 30 pyrite grains from CheshmehZard are given in Table 1. Results The study area is located in the north of Khorasan Razavi Province 45 km to the south of Neyshabour. The area near CheshmehZard could become important as a site of economically significant gold mineralization. Six gold-bearing vein

Ligation of superior mesenteric vein and portal to splenic vein anastomosis after superior mesenteric-portal vein confluence resection during pancreaticoduodenectomy – Case report

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Jianlin Tang

2014-12-01

Conclusion: The lessons we learned are (1 Before SMPV confluence resection, internal jugular vein graft should be ready for reconstruction. (2 Synthetic graft is an alternative for internal jugular vein graft. (3 Direct portal vein to SMV anastomosis can be achieved by mobilizing liver. (4 It is possible that venous collaterals secondary to SMV tumor obstruction may have allowed this patient's post-operative survival.

Vein visualization: patient characteristic factors and efficacy of a new infrared vein finder technology.

Science.gov (United States)

Chiao, F B; Resta-Flarer, F; Lesser, J; Ng, J; Ganz, A; Pino-Luey, D; Bennett, H; Perkins, C; Witek, B

2013-06-01

We investigated the patient characteristic factors that correlate with identification of i.v. cannulation sites with normal eyesight. We evaluated a new infrared vein finding (VF) technology device in identifying i.v. cannulation sites. Each subject underwent two observations: one using the conventional method (CM) of normal, unassisted eyesight and the other with the infrared VF device, VueTek's Veinsite™ (VF). A power analysis for moderate effect size (β=0.95) required 54 samples for within-subject differences. Patient characteristic profiles were obtained from 384 subjects (768 observations). Our sample population exhibited an overall average of 5.8 [95% confidence interval (CI) 5.4-6.2] veins using CM. As a whole, CM vein visualization were less effective among obese [4.5 (95% CI 3.8-5.3)], African-American [4.6 (95% CI 3.6-5.5 veins)], and Asian [5.1 (95% CI 4.1-6.0)] subjects. Next, the VF technology identified an average of 9.1 (95% CI 8.6-9.5) possible cannulation sites compared with CM [average of 5.8 (95% CI 5.4-6.2)]. Seventy-six obese subjects had an average of 4.5 (95% CI 3.8-5.3) and 8.2 (95% CI 7.4-9.1) veins viewable by CM and VF, respectively. In dark skin subjects, 9.1 (95% CI 8.3-9.9) veins were visible by VF compared with 5.4 (95% CI 4.8-6.0) with CM. African-American or Asian ethnicity, and obesity were associated with decreased vein visibility. The visibility of veins eligible for cannulation increased for all subgroups using a new infrared device.

Palliative treatment of TIPS to portal vein tumor thrombosis complicated with portal vein hypertension

International Nuclear Information System (INIS)

Jiang Zaibo; Shan Hong; Guan Shouhai; Zhu Kangshun; Huang Mingsheng; Li Zhengran; Guo Tiansheng; Liu Lang

2002-01-01

Objective: To evaluate the palliative therapeutic effects of transjugular intrahepatic portosystemic shunt (TIPS) in portal vein tumor thrombosis (PVTT) complicated with portal vein hypertension, and to discuss the technical skills. Methods: There were 14 cases of end-stage hepatocellular carcinoma complicated with PVTT and portal vein hypertension, the average age was 53.6 yr. There were 8 cases with complete occlusion of main portal vein, 6 eases with incomplete thrombosis, and 5 cases combined with portal vein cavernous transformation. One case had simple hemorrhage, 3 eases had intractable ascites, and 10 cases had hemorrhage accompanied by intractable ascites. Results: The procedure of TIPS was successful in 10 cases, the successful rate was about 71%. The mean portal vein pressure was reduced from 37.2 mm Hg to 18.2 mm Hg, with an average reduction of 19.0 mm Hg. After the procedure of TIPS, the ascites decreased, hemorrhage stopped and the clinical symptoms disappeared. The average survival period was 132.3 days. The procedure were failing in 4 cases. Conclusion: TIPS was an effective palliative therapeutic methods to control the hemorrhage and ascites aroused by hepatic carcinoma complicated with PVTT

Concerns and Discomforts of Pregnancy - Varicose Veins

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Concerns and Discomforts of Pregnancy - Varicose Veins Varicose veins are enlarged veins you may see on your ... Healthy Roads Media project www. healthyroadsmedia. org English - Concerns and Discomforts of Pregnancy (Varicose Veins) Last reviewed ...

Corrosion cast study of the canine hepatic veins.

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Uršič, M; Vrecl, M; Fazarinc, G

2014-11-01

This study presents a detailed description of the distribution, diameters and drainage patterns of hepatic veins on the basis of the corrosion cast analysis in 18 dogs. We classified the hepatic veins in three main groups: the right hepatic veins of the caudate process and right lateral liver lobe, the middle hepatic veins of the right medial and quadrate lobes and the left hepatic veins of both left liver lobes and the papillary process. The corrosion cast study showed that the number of the veins in the Nomina Anatomica Veterinaria and most anatomical textbooks is underestimated. The number of various-sized hepatic veins of the right liver division ranged from 3 to 5 and included 1 to 4 veins from the caudate process and 2 to 4 veins from the right lateral liver lobe. Generally, in all corrosion casts, one middle-sized vein from the right part of the right medial lobe, which emptied separately in the caudal vena cava, was established. The other vein was a large-sized vein from the remainder of the central division, which frequently joined the common left hepatic vein from the left liver lobes. The common left hepatic vein was the largest of all the aforementioned hepatic veins.

Image Quality Enhancement Using the Direction and Thickness of Vein Lines for Finger-Vein Recognition

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Young Ho Park

2012-10-01

Full Text Available On the basis of the increased emphasis placed on the protection of privacy, biometric recognition systems using physical or behavioural characteristics such as fingerprints, facial characteristics, iris and finger-vein patterns or the voice have been introduced in applications including door access control, personal certification, Internet banking and ATM machines. Among these, finger-vein recognition is advantageous in that it involves the use of inexpensive and small devices that are difficult to counterfeit. In general, finger-vein recognition systems capture images by using near infrared (NIR illumination in conjunction with a camera. However, such systems can face operational difficulties, since the scattering of light from the skin can make capturing a clear image difficult. To solve this problem, we proposed new image quality enhancement method that measures the direction and thickness of vein lines. This effort represents novel research in four respects. First, since vein lines are detected in input images based on eight directional profiles of a grey image instead of binarized images, the detection error owing to the non-uniform illumination of the finger area can be reduced. Second, our method adaptively determines a Gabor filter for the optimal direction and width on the basis of the estimated direction and thickness of a detected vein line. Third, by applying this optimized Gabor filter, a clear vein image can be obtained. Finally, the further processing of the morphological operation is applied in the Gabor filtered image and the resulting image is combined with the original one, through which finger-vein image of a higher quality is obtained. Experimental results from application of our proposed image enhancement method show that the equal error rate (EER of finger-vein recognition decreases to approximately 0.4% in the case of a local binary pattern-based recognition and to approximately 0.3% in the case of a wavelet transform

Normal hepatic vein patterns on ultrasound

International Nuclear Information System (INIS)

Kim, Hae Jin; Chae, Yoo Soon; Park, Hea Yeoung; Park, Bok Hwan; Kim, Yang Sook

1987-01-01

Understanding of the anatomy of the hepatic vein is important in manipulation for transplantation of the liver, hepatectomy and the treatment of hepatic trauma with avulsion of the hepatic vein. Demonstrated of the inferior right hepatic vein (IRHV) is also important; in some cases of hepatocellular carcinoma, thrombus can be seen in the IRHV; in primary Budd-Chiari syndrome, the IRHV is main draining vein; during hepatectomy, the postero-inferior segment of the right lobe and draining IRHV can be preserved. For some 10 months ultrasound examination was done in a total of 124 patients with normal liver function with special emphasis on the hepatic vein, their branches, and the IRHV, and analysed in terms of branching pattern and relative size of the hepatic vein and the detection rate of the IRHV.

Sectional localization of a small hepatocellular carcinoma in the right hepatic lobe by computed tomography: Comparison between the conventional and portal vein tracing methods

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Zhou, Chun-Gao [Seoul National University Hospital, Department of Radiology, Jongro-gu, Seoul (Korea, Republic of); The First Affiliated Hospital of Nanjing Medical University, Department of Interventional Radiology, Nanjing (China); Chung, Jin Wook; Hur, Saebeom; Lee, Myungsu; Kim, Hyo-Cheol; Jae, Hwan Jun; Yin, Yong-Hu; Kim, Young Il [Seoul National University Hospital, Department of Radiology, Jongro-gu, Seoul (Korea, Republic of); Ahn, Sang-bu [Dongnam Institution of Radiological and Medical Sciences, Department of Radiology, Busan (Korea, Republic of); Cho, Baik Hwan [Chonbuk National University Hospital, Department of Radiology, Jeonju (Korea, Republic of)

2016-12-15

To compare the accuracy of the conventional and portal vein tracing methods in the right hepatic lobe in multidetector computed tomography (MDCT). This retrospective study included patients with hepatocellular carcinoma (HCC) lesions in the right hepatic lobe who underwent multiphasic MDCT and C-arm CT hepatic arteriography (C-arm CTHA) for chemoembolization. The accuracies of the conventional and portal vein tracing methods were evaluated using C-arm CTHA as the gold standard. A total of 147 patients with 205 HCC nodules were included. The C-arm CTHA could identify all the tumour-feeding arteries and consequently demonstrated that 120 lesions were located in the anterior section, 78 in the posterior section, and 7 in the border zone. The accuracy rates of conventional vs. portal vein tracing methods were 71.7 % vs. 98.3 % for the anterior section lesions, 67.9 % vs. 96.2 % for the posterior section, and 28.6 % vs. 57.1 % for the border zone. The portal vein tracing method was more accurate than the conventional method (P<0.001). The portal vein tracing method should be used for sectional localization of HCCs in the right lobe, because it predicts the location more accurately than the conventional method. (orig.)

40Ar/39Ar constraints on the timing and history of amphibolite facies gold mineralisation in the Southern Cross area, Western Australia

International Nuclear Information System (INIS)

Napier, R.W.; Guise, P.G.; Rex, D.C.

1998-01-01

The Southern Cross Greenstone Belt in Western Australia contains structurally controlled, hydrothermal gold deposits which are thought to have formed at or near the peak of amphibolite facies regional metamorphism during the Late Archaean. Although the geological features of deposits in the area are well documented. conflicting genetic models and ore-fluid sources have been used to explain the observed geological data. This paper presents new 40 Ar/ 39 Ar data which suggest that the thermal history of the Southern Cross area after the peak of regional metamorphism was more complex than has previously been suggested. After the main gold mineralisation event prior to ca 2620 Ma, the 40 Ar/ 39 Ar ages from amphiboles and biotites sampled from the alteration selvages of gold-bearing veins indicate that temperatures remained elevated in the region of 500 deg C for between 20 and 70 million years. These amphiboles and biotites from individual deposits yield ages that are in good agreement with one another to a high precision. implying increased cooling rates after the long period of elevated temperatures. Along the Southern Cross Greenstone Belt. however. amphibole-biotite pairs from the alteration selvages of gold-bearing quartz veins. while remaining in good agreement with one another, vary between deposits from ca 2560 Ma to ca 2440 Ma. Amphiboles from metabasalts that are associated with regional metamorphism and not hydrothermal alteration contain numerous exsolution lamellae that reduce the effective closure temperature of the amphiboles and yield geologically meaningless ages. These age relationships show that the thermal history of the area did not follow a simple cooling path and the area may have been tectonically active for a long period after the main gold mineralisation event before ca 2620 Ma. Such data may provide important constraints on subsequent genetic modelling of gold mineralisation and metamorphism. Copyright (1998) Blackwell Science Asia

The umbilical and paraumbilical veins of man.

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Martin, B F; Tudor, R G

1980-03-01

During its transit through the umbilicus structural changes occur in the thick wall of the extra-abdominal segment of the umbilical vein whereby the components of the intra-abdominal segment acquire an essentially longitudinal direction and become arranged in fibro-elastic and fibro-muscular zones. The vein lumen becomes largely obliterated by asymmetrical proliferation of loose subendothelial conective tissue. The latter forms a new inner zone within which a small segment of the lumen persists in an eccentric position. This residual lumen transmits blood to the portal system from paraumbilical and systemic sources, and is retained in the upper part of the vein, even in old age. A similar process of lumen closure is observed in the ductus venosus. In early childhood the lower third of the vein undergoes breakdown, with fatty infiltration, resulting in its complete division into vascular fibro-elastic strands, and in old age some breakdown occurs in the outermost part of the wall of the upper two thirds. The paraumbilical veins are thick-walled and of similar structure to the umbilical vein. Together they constitute an accessory portal system which is confined between the layers of the falciform ligament and is in communication with the veins of the ventral abdominal wall. The constituents form an ascending series, namely, Burow's veins, the umbilical vein, and Sappey's inferior and superior veins. The main channel of Sappey's inferior veins may be the remnant of the right umbilical vein since it communicates with the right rectus sheath and often communicates directly with the portal system within the right lobe of the liver. The results are of significance in relation to clinical usage of the umbilical vein.

Idiopathic Bilateral External Jugular Vein Thrombosis.

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Hindi, Zakaria; Fadhel, Ehab

2015-08-20

Vein thrombosis is mainly determined by 3 factors, which constitute a triad called Virchow's triad: hypercoagulability, stasis, and endothelial injury. Venous thrombosis commonly occurs in the lower extremities since most of the blood resides there and flows against gravity. The veins of the lower extremities are dependent on intact valves and fully functional leg muscles. However, in case of valvular incompetency or muscular weakness, thrombosis and blood stasis will occur as a result. In contrast, the veins of the neck, specially the jugulars, have distensible walls which allow flexibility during respiration. In addition, the blood directly flows downward towards the heart. Nevertheless, many case reports mentioned the thrombosis of internal jugular veins and external jugular veins with identified risk factors. Jugular vein thrombosis has previously been associated in the literature with a variety of medical conditions, including malignancy. This report is of a case of idiopathic bilateral external jugular vein thrombosis in a 21 year-old male construction worker of Southeast Asian origin with no previous medical history who presented with bilateral facial puffiness of gradual onset over 1 month. Doppler ultrasound and computed tomography were used in the diagnosis. Further work-up showed no evidence of infection or neoplasia. The patient was eventually discharged on warfarin. The patient was assessed after 6 months and his symptoms had resolved completely. Bilateral idiopathic external jugular veins thrombosis is extremely rare and can be an indicator of early malignancy or hidden infection. While previous reports in the literature have associated jugular vein thrombosis with malignancy, the present case shows that external jugular vein thrombosis can also be found in persons without malignancy.

Blood sampling from adrenal gland vein

International Nuclear Information System (INIS)

Sun Yong; Ni Caifang

2009-01-01

Adrenal gland vein sampling is an interventional method to get the blood samples from the adrenal gland vein. The blood is obtained via a catheter which is selectively inserted in the adrenal gland vein. This technique is mainly used to be diagnostic for primary hyperaldosteronism. A full knowledge of the anatomy and variations of the adrenal gland vein, serious preoperative preparation and skilled catheterization manipulation are necessary for obtaining sufficient blood sample and for reducing the occurrence of complications. Providing the physicians with definite diagnostic evidence and being technically feasible, adrenal gland vein sampling should become one of the routine examinations for clarifying the cause of primary hyperaldosteronism. (authors)

Isolated inferior mesenteric portal hypertension with giant inferior mesenteric vein and anomalous inferior mesenteric vein insertion

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G Raghavendra Prasad

2013-01-01

Full Text Available Extrahepatic portal hypertension is not an uncommon disease in childhood, but isolated inferior mesenteric portal varices and lower gastrointestinal (GI bleed have not been reported till date. A 4-year-old girl presented with lower GI bleed. Surgical exploration revealed extrahepatic portal vein obstruction with giant inferior mesenteric vein and colonic varices. Inferior mesenteric vein was joining the superior mesenteric vein. The child was treated successfully with inferior mesenteric - inferior vena caval anastomosis. The child was relieved of GI bleed during the follow-up.

Multimodal ultrasonographic assessment of leiomyosarcoma of the femoral vein in a patient misdiagnosed as having deep vein thrombosis

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Zhang, Mei; Yan, Feng; Huang, Bin; Wu, Zhoupeng; Wen, Xiaorong

2017-01-01

Abstract Rationale: Primary leiomyosarcoma (LMS) of the vein is a rare tumor that arises from the smooth muscle cells of the vessel wall and has an extremely poor prognosis. This tumor can occur in vessels such as the inferior vena cava, great saphenous vein, femoral vein, iliac vein, popliteal vein, and renal vein; the inferior vena cava is the most common site. LMS of the femoral vein can result in edema and pain in the lower extremity; therefore, it is not easy to be differentiated from deep vein thrombosis (DVT). Moreover, virtually no studies have described the ultrasonographic features of LMS of the vein in detail. Patient concerns: We present a case of a 55-year-old woman with LMS of the left femoral vein that was misdiagnosed as having deep vein thrombosis (DVT) on initial ultrasonographic examination. The patient began to experience edema and pain in her left leg seven months previously. She was diagnosed as having DVT on initial ultrasonographic examination, but the DVT treatment that she had received for 7 months failed to improve the status of her left lower limb. Diagnoses: She subsequently underwent re-examination by means of a multimodal ultrasonographic imaging approach (regular B-mode imaging, color Doppler imaging, pulsed-wave Doppler imaging, contrast-enhanced ultrasonography), which confirmed a diagnosis of LMS. Interventions: This patient was treated successfully with surgery. Outcomes: This case demonstrates that use of multiple ultrasonographic imaging techniques can be helpful to diagnose LMS accurately. Detection of vasculature in a dilated vein filled with a heterogeneous hypoechoic substance on ultrasonography is a sign of a tumor. Lessons: The pitfall of misdiagnosing this tumor as DVT is a useful reminder. PMID:29145269

Duplex sonography of the near-surface leg veins

International Nuclear Information System (INIS)

Mendoza, E.

2007-01-01

The book contains the following contributions: The ultrasonograph, selection of the ultrasonic transducer, anatomy of the near-surface vein system, physiology of the near-surface vein system, varicose status classification, systematics of the duplex sonography of near-surface leg veins, provocational maneuver for the duplex sonographic varicose diagnostics, exploration of vena saphena parva, perforans veins, side branches, phlebitis, sonography for varicose therapy, postsurgical sonography, deep leg veins, examination of near-surface leg veins for the pathology of the deep vein system, differential diagnostic clarification of leg oedema from the phlebologic-lymphological view, diagnostic side features along the near-surface leg veins

Self-taught axillary vein access without venography for pacemaker implantation: prospective randomized comparison with the cephalic vein access.

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Squara, Fabien; Tomi, Julien; Scarlatti, Didier; Theodore, Guillaume; Moceri, Pamela; Ferrari, Emile

2017-12-01

Axillary vein access for pacemaker implantation is uncommon in many centres because of the lack of training in this technique. We assessed whether the introduction of the axillary vein technique was safe and efficient as compared with cephalic vein access, in a centre where no operators had any previous experience in axillary vein puncture. Patients undergoing pacemaker implantation were randomized to axillary or cephalic vein access. All three operators had no experience nor training in axillary vein puncture, and self-learned the technique by reading a published review. Axillary vein puncture was fluoroscopy-guided without contrast venography. Cephalic access was performed by dissection of delto-pectoral groove. Venous access success, venous access duration (from skin incision to guidewire or lead in superior vena cava), procedure duration, X-ray exposure, and peri-procedural (1 month) complications were recorded. results We randomized 74 consecutive patients to axillary (n = 37) or cephalic vein access (n = 37). Axillary vein was successfully accessed in 30/37 (81.1%) patients vs. 28/37 (75.7%) of cephalic veins (P = 0.57). Venous access time was shorter in axillary group than in cephalic group [5.7 (4.4-8.3) vs. 12.2 (10.5-14.8) min, P < 0.001], as well as procedure duration [34.8 (30.6-38.4) vs. 42.0 (39.1-46.6) min, P = 0.043]. X-ray exposure and peri-procedural overall complications were comparable in both groups. Axillary puncture was safe and faster than cephalic access even for the five first procedures performed by each operator. Self-taught axillary vein puncture for pacemaker implantation seems immediately safe and faster than cephalic vein access, when performed by electrophysiologists trained to pacemaker implantation but not to axillary vein puncture. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For Permissions, please email: journals.permissions@oup.com.

Portal vein thrombosis.

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Chawla, Yogesh K; Bodh, Vijay

2015-03-01

Portal vein thrombosis is an important cause of portal hypertension. PVT occurs in association with cirrhosis or as a result of malignant invasion by hepatocellular carcinoma or even in the absence of associated liver disease. With the current research into its genesis, majority now have an underlying prothrombotic state detectable. Endothelial activation and stagnant portal blood flow also contribute to formation of the thrombus. Acute non-cirrhotic PVT, chronic PVT (EHPVO), and portal vein thrombosis in cirrhosis are the three main variants of portal vein thrombosis with varying etiological factors and variability in presentation and management. Procoagulant state should be actively investigated. Anticoagulation is the mainstay of therapy for acute non-cirrhotic PVT, with supporting evidence for its use in cirrhotic population as well. Chronic PVT (EHPVO) on the other hand requires the management of portal hypertension as such and with role for anticoagulation in the setting of underlying prothrombotic state, however data is awaited in those with no underlying prothrombotic states. TIPS and liver transplant may be feasible even in the setting of PVT however proper selection of candidates and type of surgery is warranted. Thrombolysis and thrombectomy have some role. TARE is a new modality for management of HCC with portal vein invasion.

Case report: Varicosity of the communicating vein between the left renal vein and the left ascending lumbar vein mimicking a renal artery aneurysm: Report of an unusual site of varicose veins and a novel hypothesis to explain its association with abdominal pain

Directory of Open Access Journals (Sweden)

Sandeep G Jakhere

2011-01-01

Full Text Available A communicating vein between the left renal vein and the left ascending lumbar vein has only rarely been reported in the imaging literature. There are very few reports of varicosity of this communicating vein. Nonetheless, awareness about this communicating vein is of utmost importance for surgeons performing aortoiliac surgeries and nephrectomies as it may pose technical difficulties during surgery or cause life-threatening retroperitoneal hemorrhage. Varicosity of this venous channel may be mistaken for paraaortic lymphadenopathy, adrenal pseudo-mass, or renal artery aneurysm. We report a case of a patient with varicosity of this communicating vein, which mimicked a left renal artery aneurysm. A novel hypothesis is also proposed to explain the relationship with abdominal pain.

Interventional treatment of iliac vein compression syndrome

International Nuclear Information System (INIS)

Li Xiaoqiang; Zhou Weiming; Nie Zhonglin; Yu Chaowen

2002-01-01

Objective: To explore the clinical significance of interventional treatment of iliac vein compression syndrome (IVCS). Methods: Percutaneous transluminal angioplasty (PTA) was performed in 40 cases. Thirty-three cases underwent endovascular stent implantation and 27 cases underwent second-stage left saphenous vein ligation and stripping and the valves of left femoral veins narrowing. Thirty-one cases were followed-up postoperatively and the duration was 6-66 months (mean 28 months). Results: The dilation of iliac veins was successful in 36 cases and there were god efficacy in all patients when they discharged from hospital. Followed-up during post-operation, all the limbs ulcers were cured and varicose veins disappeared. The skin pigmentation disappeared in 17 of 19 cases and markedly relieved in 2 cases. Left lower limb swelling disappeared in 15 of 17 cases and relieved in 2 cases. Conclusion: There is good efficacy in the interventional treatment of left iliac vein lesions, but second-stage procedures should be performed in secondary lesions of saphenous veins and valves of femoral veins

Superparamagnetic core/shell GoldMag nanoparticles: size-, concentration- and time-dependent cellular nanotoxicity on human umbilical vein endothelial cells and the suitable conditions for magnetic resonance imaging.

Science.gov (United States)

Gong, Mingfu; Yang, Hua; Zhang, Song; Yang, Yan; Zhang, Dong; Qi, Yueyong; Zou, Liguang

2015-03-25

GoldMag nanoparticles (GMNPs) possess the properties of colloid gold and superparamagnetic iron oxide nanoparticles, which make them useful for delivery, separation and molecular imaging. However, because of the nanometer effect, GMNPs are highly toxic. Thus, the biosafety of GMNPs should be fully studied prior to their use in biomedicine. The main purpose of this study was to evaluate the nanotoxicity of GMNPs on human umbilical vein endothelial cells (HUVECs) and determine a suitable size, concentration and time for magnetic resonance imaging (MRI). Transmission electron microscopy showed that GMNPs had a typical shell/core structure, and the shell was confirmed to be gold using energy dispersive spectrometer analysis. The average sizes of the 30 and 50 nm GMNPs were 30.65 ± 3.15 and 49.23 ± 5.01 nm, respectively, and the shell thickness were 6.8 ± 0.65 and 8.5 ± 1.36 nm, respectively. Dynamic light scattering showed that the hydrodynamic diameter of the 30 and 50 nm GMNPs were 33.2 ± 2.68 and 53.12 ± 4.56 nm, respectively. The r 2 relaxivity of the 50 nm GMNPs was 98.65 mM(-1) s(-1), whereas it was 80.18 mM(-1) s(-1) for the 30 nm GMNPs. The proliferation, cytoskeleton, migration, tube formation, apoptosis and ROS generation of labeled HUVECs depended on the size and concentration of GMNPs and the time of exposure. Because of the higher labeling rate, the 50 nm GMNPs exhibited a significant increase in nanotoxicity compared with the 30 nm GMNPs at the same concentration and time. At no more than 25 μg/mL and 12 hours, the 50 nm GMNPs exhibited no significant nanotoxicity in HUVECs, whereas no toxicity was observed at 50 μg/mL and 24 hours for the 30 nm GMNPs. These results demonstrated that the nanotoxicity of GMNPs in HUVECs depended on size, concentration and time. Exposure to larger GMNPs with a higher concentration for a longer period of time resulted in a higher labeling rate and ROS level for HUVECs. Coupled with r 2 relaxivity, it was suggested

Chemical changes during alteration of volcanic rocks and gold ore formation, La Libertad, Nicaragua

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Darce, M.; Levi, B.; Nyström, J. O.

A chemical comparison between altered and unaltered basic lavas from a Tertiary epithermal gold deposit at La Libertad and its surroundings in central Nicaragua shows that chemical changes associated with the geothermal field type of alteration centered at the mining district reach more than 5 km away from it. Titanium seems to have been immobile, H 2O, CO 2, K, and S have been added, and Ni, Mg, and Cl partly lost from the fossil geothermal system. Gold, originally concentrated in the glass of basic lavas, was leached during zeolite facies conditions and precipitated with silica in fractures, forming veins in the center of the geothermal field. An estimate shows that the amount of Au released during the alteration was sufficient to form the La Libertad deposit.

The angiographic demonstration of hepatic vein obstruction

International Nuclear Information System (INIS)

Zu Maoheng; Xu Hao; Li Guojun; Gu Yuming; Wei Ning; Wang Cheng; Xu Wei

2004-01-01

Objective: To evaluate the angiographic feature of hepatic vein obstruction. Methods Forty-five patients (male 23, female 22, age 9-54 years) suffered from hepatic vein obstruction. The inferior vena cavography and the hepatic venography were performed in all cases. Results: IVC was free in 37 patients with hepatic vein obstruction, both IVC and HV were obstructed in 8 patients. The local or long stenosis of IVC was found in 31 inferior vena cavography. The diameter of IVC was normal in 12 patients. The sign of membranous dome was found in hepatic vein orifice in 5 cases and in accessory hepatic vein orifice in 4 cases. Intrahepatic venous collaterals were found in 45 cases. Conclusion: Hepatic vein obstruction can be reproached primarily in inferior vena cavography, the membranous dome is a direct sign of membranous obstruction of HV and AHV in inferior vena cavography. The selected hepatic venography can provide reliable evidence to diagnose hepatic vein obstruction

A Vein Map Biometric System

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Felix Fuentes

2013-08-01

Full Text Available There is increasing demand world-wide, from government agencies and the private sector for cutting-edge biometric security technology that is difficult to breach but userfriendly at the same time. Some of the older tools, such as fingerprint, retina and iris scanning, and facial recognition software have all been found to have flaws and often viewed negatively because of many cultural and hygienic issues associated with them. Comparatively, mapping veins as a human barcode, a new technology, has many advantages over older technologies. Specifically, reproducing a three-dimensional model of a human vein system is impossible to replicate. Vein map technology is distinctive because of its state-of-the-art sensors are only able to recognize vein patterns if hemoglobin is actively flowing through the person

The gold nuggets of the lower Pliocene Alhambra Formation (Betic Cordillera, Southern Spain)

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Somma, Roberta; Bonvegna, Piero; Sanchez-Navas, Antonio

2017-04-01

The present research was devoted to the geochemical and textural characterization of gold nuggets extracted from auriferous siliciclastic deposits of the lower Pliocene continental Alhambra Formation (Betic Cordillera, Southern Spain). This Formation is mainly composed of metamorphic lithoclasts deriving both by the erosion of the Mulhacen Unit of the Nevado-Filabride Complex and the reworking of the upper Tortonian marine Dudar-Pinos Genil Formation, on its turn previously formed by erosion of the Veleta Unit of the Nevado-Filabride Complex. Particularly, the studied gold nuggets were separated from 1m3 of auriferous conglomerates sampled along the right side of the Genil River, in the abandoned Lancha de Cenes Mine, exploited since Roman time for gold mining. The recovered gold nuggets were 24 for a total weight of 0.125 g/m3. Textural analysis of gold nuggets was made by means mechanical sieving and visual comparison of roundness and form. They are sand-sized rounded to sub-rounded grains with spheroidal and cubic form. Surface analyses of the nuggets by SEM-EDS indicated that external portions show textures more porous than in the nuggets nuclei. Chemical analyses by EMPA indicated that they are constituted by pure gold with Ag and Hg as trace elements. The gold mine capacity of the studied auriferous deposits is at least of 0.125 g/m3 (lower than 0.5 g/m3; minimum value to be gold mine economically exploitable). Notwithstanding this value, the auriferous conglomerates of the Alhambra Formation reveal to be interesting under a gold mine exploitation point of view because of the gold high pureness degree. Finally, under a geological point of view, considering that the Alhambra Formation is mainly composed of lower Pliocene alluvial fan conglomerates and sandstones formed during the uplift of the Sierra Nevada, the selected gold nuggets are secondary deposits originally derived from primary deposits related to hydrothermal gold-bearing quartz veins included in

Deep vein thrombosis of the leg

Energy Technology Data Exchange (ETDEWEB)

Lee, Eun Hee; Rhee, Kwang Woo; Jeon, Suk Chul; Joo, Kyung Bin; Lee, Seung Ro; Seo, Heung Suk; Hahm, Chang Kok [College of Medicine, Hanyang University, Seoul (Korea, Republic of)

1987-04-15

Ascending contrast venography is the definitive standard method for the diagnosis of deep vein thrombosis (DVT) of the lower extremities. Authors analysed 22 cases of DVT clinically and radiographically. 1.The patients ranged in age from 15 to 70 yrs and the most prevalent age group was 7th decade (31%). There was an equal distribution of males and females. 2.In 11 cases of 22 cases, variable etiologic factors were recognized, such as abdominal surgery, chronic bedridden state, local trauma on the leg, pregnancy, postpartum, Behcet's syndrome, iliac artery aneurysm, and chronic medication of estrogen. 3.Nineteen cases out of 22 cases showed primary venographic signs of DVT, such as well-defined filling defect in opacified veins and narrowed, irregularly filled venous lumen. In only 3 cases, the diagnosis of DVT was base upon the segmental nonvisualization of deep veins with good opacification of proximal and distal veins and presence of collaterals. 4.Extent of thrombosis: 3 cases were confined to calf vein, 4 cases extended to femoral vein, and 15 cases had involvement above iliac vein. 5.In 17 cases involving relatively long segment of deep veins, propagation pattern of thrombus was evaluated by its radiologic morphology according to the age of thrombus: 9 cases suggested central or antegrade propagation pattern and 8 cases, peripheral or retrograde pattern. 6.None of 22 cases showed clinical evidence of pulmonary embolism. The cause of the rarity of pulmonary embolism in Korean in presumed to be related to the difference in major involving site and propagation pattern of DVT in the leg.

Deep vein thrombosis of the leg

International Nuclear Information System (INIS)

Lee, Eun Hee; Rhee, Kwang Woo; Jeon, Suk Chul; Joo, Kyung Bin; Lee, Seung Ro; Seo, Heung Suk; Hahm, Chang Kok

1987-01-01

Ascending contrast venography is the definitive standard method for the diagnosis of deep vein thrombosis (DVT) of the lower extremities. Authors analysed 22 cases of DVT clinically and radiographically. 1.The patients ranged in age from 15 to 70 yrs and the most prevalent age group was 7th decade (31%). There was an equal distribution of males and females. 2.In 11 cases of 22 cases, variable etiologic factors were recognized, such as abdominal surgery, chronic bedridden state, local trauma on the leg, pregnancy, postpartum, Behcet's syndrome, iliac artery aneurysm, and chronic medication of estrogen. 3.Nineteen cases out of 22 cases showed primary venographic signs of DVT, such as well-defined filling defect in opacified veins and narrowed, irregularly filled venous lumen. In only 3 cases, the diagnosis of DVT was base upon the segmental nonvisualization of deep veins with good opacification of proximal and distal veins and presence of collaterals. 4.Extent of thrombosis: 3 cases were confined to calf vein, 4 cases extended to femoral vein, and 15 cases had involvement above iliac vein. 5.In 17 cases involving relatively long segment of deep veins, propagation pattern of thrombus was evaluated by its radiologic morphology according to the age of thrombus: 9 cases suggested central or antegrade propagation pattern and 8 cases, peripheral or retrograde pattern. 6.None of 22 cases showed clinical evidence of pulmonary embolism. The cause of the rarity of pulmonary embolism in Korean in presumed to be related to the difference in major involving site and propagation pattern of DVT in the leg

Gold film with gold nitride - A conductor but harder than gold

International Nuclear Information System (INIS)

Siller, L.; Peltekis, N.; Krishnamurthy, S.; Chao, Y.; Bull, S.J.; Hunt, M.R.C.

2005-01-01

The formation of surface nitrides on gold films is a particularly attractive proposition, addressing the need to produce harder, but still conductive, gold coatings which reduce wear but avoid the pollution associated with conventional additives. Here we report production of large area gold nitride films on silicon substrates, using reactive ion sputtering and plasma etching, without the need for ultrahigh vacuum. Nanoindentation data show that gold nitride films have a hardness ∼50% greater than that of pure gold. These results are important for large-scale applications of gold nitride in coatings and electronics

Bilateral meandering pulmonary veins

Energy Technology Data Exchange (ETDEWEB)

Thupili, Chakradhar R.; Udayasankar, Unni [Pediatric Imaging, Imaging Institute Cleveland Clinic, Cleveland, OH (United States); Renapurkar, Rahul [Imaging Institute Cleveland Clinic, Thoracic Imaging, L10, Cleveland, OH (United States)

2015-06-15

Meandering pulmonary veins is a rare clinical entity that can be mistaken for more complex congenital syndromes such as hypogenetic lung syndrome. We report imaging findings in a rare incidentally detected case of bilateral meandering pulmonary veins. We briefly discuss the role of imaging in diagnosing this condition, with particular emphasis on contrast-enhanced CT. (orig.)

Magmatic-dominated fluid evolution in the Jurassic Nambija gold skarn deposits (southeastern Ecuador)

Science.gov (United States)

Vallance, Jean; Fontboté, Lluís; Chiaradia, Massimo; Markowski, Agnès; Schmidt, Susanne; Vennemann, Torsten

2009-05-01

The Jurassic (approximately 145 Ma) Nambija oxidized gold skarns are hosted by the Triassic volcanosedimentary Piuntza unit in the sub-Andean zone of southeastern Ecuador. The skarns consist dominantly of granditic garnet (Ad20-98) with subordinate pyroxene (Di46-92Hd17-42Jo0-19) and epidote and are spatially associated with porphyritic quartz-diorite to granodiorite intrusions. Endoskarn is developed at the intrusion margins and grades inwards into a potassic alteration zone. Exoskarn has an outer K- and Na-enriched zone in the volcanosedimentary unit. Gold mineralization is associated with the weakly developed retrograde alteration of the exoskarn and occurs mainly in sulfide-poor vugs and milky quartz veins and veinlets in association with hematite. Fluid inclusion data for the main part of the prograde stage indicate the coexistence of high-temperature (500°C to >600°C), high-salinity (up to 65 wt.% eq. NaCl), and moderate- to low-salinity aqueous-carbonic fluids interpreted to have been trapped at pressures around 100-120 MPa, corresponding to about 4-km depth. Lower-temperature (510-300°C) and moderate- to low-salinity (23-2 wt.% eq. NaCl) aqueous fluids are recorded in garnet and epidote of the end of the prograde stage. The microthermometric data (Th from 513°C to 318°C and salinity from 1.0 to 23 wt.% eq. NaCl) and δ18O values between 6.2‰ and 11.5‰ for gold-bearing milky quartz from the retrograde stage suggest that the ore-forming fluid was dominantly magmatic. Pressures during the early retrograde stage were in the range of 50-100 MPa, in line with the evidence for CO2 effervescence and probable local boiling. The dominance of magmatic low-saline to moderately saline oxidizing fluids during the retrograde stage is consistent with the depth of the skarn system, which could have delayed the ingression of external fluids until relatively low temperatures were reached. The resulting low water-to-rock ratios explain the weak retrograde alteration

Oxygen isotope zonation at the Golden Cross low-sulfidation epithermal gold deposit, New Zealand

International Nuclear Information System (INIS)

Mauk, J.L.; Simpson, M.P.

2001-01-01

Forty-one whole rock samples from the Gold Cross low-sulfidation epithermal Au-Ag deposit have δ 18 O values that range from 4.4 to 9.3 per mil, with an average value of 7.0 per mil. Unaltered and weakly altered rocks have δ 18 O values greater than 8 per mil, and the orebody is surrounded by samples that are depleted in 18 O. A strongly silicified sample adjacent to the Empire Vein System has a δ 18 O value of 9.0 per mil, similar to previously reported analyses of vein quartz (7.0 to 11.7 per mil, average 9.4 per mil). This suggests that, in detail, Golden Cross may have a zone of 18 O-enriched wall rocks in the core of the deposit, adjacent to the main underground veins. Although some workers have suggested that stable isotope geochemistry may provide useful information for epithermal mineral deposit exploration, at Golden Cross this is not the case. Alteration minerals, major elements and trace elements all define larger, less ambiguous halos than the zone of 18 O-depleted wall rocks. (author). 21 refs., 3 figs., 1 tab

Fault geometry and fluid-rock reaction: Combined controls on mineralization in the Xinli gold deposit, Jiaodong Peninsula, China

Science.gov (United States)

Yang, Lin; Zhao, Rui; Wang, Qingfei; Liu, Xuefei; Carranza, Emmanuel John M.

2018-06-01

The structures and fluid-rock reaction in the Xinli gold deposit, Jiaodong Peninsula, were investigated to further understand their combined controls on the development of permeability associated with ore-forming fluid migration. Orebodies in this deposit are hosted by the moderately SE-to S-dipping Sanshandao-Cangshang fault (SCF). Variations in both dip direction and dip angle along the SCF plane produced fault bends, which controlled the fluid accumulation and ore-shoot formation. Gold mineralizations occurred in early gold-quartz-pyrite and late gold-quartz-polymetallic sulphide stages following pervasive sericitization and silicification alterations. Theoretical calculation indicates that sericitization caused 8-57% volume decrease resulting in the development/enlargement of voids, further increase of grain-scale permeability, and resultant precipitation of the early gold-quartz-pyrite pods, which destroyed permeability. The rock softening produced by alterations promoted activities of SCF secondary faults and formation of new fractures, which rebuilt the permeability and controlled the late gold-quartz-polymetallic sulfide veins. Quantitative studies on permeability distributions show that the southwestern and northeastern bend areas with similar alteration and mineralization have persistent and anti-persistent permeability networks, respectively. These were likely caused by different processes of rebuilding permeability due to different stress states resulting from changes in fault geometry.

The veining phenomenon in unalloyed plutonium

International Nuclear Information System (INIS)

White, J.S.

1976-01-01

An investigation has been made of the veining phenomenon in unalloyed plutonium. The surface markings, or veins, which are sometimes seen on α-phase plutonium samples, arise as a result of the β→α transformation. As far as is known, this veining is unrivalled in its scale and form as compared with the solid state surface transformation effects shown by any other metal. The phenomenon has been explained by the application of the Le Chatelier principle to the phase change. In this instance, the large (10%) volume contraction associated with the β→α reaction and the anisotropy of the nonoclinic α-phase structure, account for the fact that the veins are so prominent in plutonium. On the basis of the proposed model, the veins can only form at temperatures where the transformation mechanism is non-martensitic. (Auth.)

Unusual termination of the right testicular vein | Woldeyes | Anatomy ...

African Journals Online (AJOL)

The testicular veins are formed by the veins emerging from the testis and epididymis forming the pampiniform venous plexus. The right testicular vein drains into inferior vena cava and the left testicular vein to the left renal vein. Testicular veins display a great variability with regard to their number, course and sites of ...

An unusual case: right proximal ureteral compression by the ovarian vein and distal ureteral compression by the external iliac vein

Directory of Open Access Journals (Sweden)

Halil Ibrahim Serin

2015-12-01

Full Text Available A 32-years old woman presented to the emergency room of Bozok University Research Hospital with right renal colic. Multidetector computed tomography (MDCT showed compression of the proximal ureter by the right ovarian vein and compression of the right distal ureter by the right external iliac vein. To the best of our knowledge, right proximal ureteral compression by the ovarian vein together with distal ureteral compression by the external iliac vein have not been reported in the literature. Ovarian vein and external iliac vein compression should be considered in patients presenting to the emergency room with renal colic or low back pain and a dilated collecting system.

Application of kinematic vorticity and gold mineralization for the wall rock alterations of shear zone at Dungash gold mining, Central Eastern Desert, Egypt

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Kassem, Osama M. K.; Abd El Rahim, Said H.; El Nashar, EL Said R.; AL Kahtany, Kaled M.

2016-11-01

The use of porphyroclasts rotating in a flowing matrix to estimate mean kinematic vorticity number (Wm) is important for quantifying the relative contributions of pure and simple shear in wall rocks alterations of shear zone at Dungash gold mine. Furthermore, it shows the relationship between the gold mineralization and deformation and also detects the orientation of rigid objects during progressive deformation. The Dungash gold mine area is situated in an EW-trending quartz vein along a shear zone in metavolcanic and metasedimentary host rocks in the Eastern Desert of Egypt. These rocks are associated with the major geologic structures which are attributed to various deformational stages of the Neoproterozoic basement rocks. We conclude that finite strain in the deformed rocks is of the same order of magnitude for all units of metavolcano-sedimentary rocks. The kinematic vorticity number for the metavolcanic and metasedimentary samples in the Dungash area range from 0.80 to 0.92, and together with the strain data suggest deviations from simple shear. It is concluded that nappe stacking occurred early during the underthrusting event probably by brittle imbrication and that ductile strain was superimposed on the nappe structure during thrusting. Furthermore, we conclude that disseminated mineralization, chloritization, carbonatization and silicification of the wall rocks are associated with fluids migrating along shearing, fracturing and foliation of the metamorphosed wall rocks.

Investigation of adverse events associated with an off-label use of arterial stents and CE-marked iliac vein stents in the iliac vein: insights into developing a better iliac vein stent.

Science.gov (United States)

Shida, Takuya; Umezu, Mitsuo; Iwasaki, Kiyotaka

2018-06-01

We analyzed the adverse events associated with an off-label use of arterial stents and CE-marked iliac vein stents for the treatment of iliac venous thromboembolism and investigated their relationships with the anatomical features of the iliac vein, to gain insights into the development of a better iliac vein stent. Reports of adverse events following the use of stents in the iliac vein were retrieved from the Manufacturer and User Facility Device Experience (MAUDE) database that contain suspected device-associated complications reported to the Food and Drug Administration. Data from 2006 to 2016 were investigated. The literature analysis was also conducted using PubMed, Cochrane Library, EMBASE, and Web of Science focusing on English articles published up to 4 October 2016. The analysis of 88 adverse events from the MAUDE database and 182 articles from the literature revealed that a higher number of adverse events had been reported following the use of arterial stents in the iliac vein compared to CE-marked iliac vein stents. While stent migration and shortening were reported only for the arterial stents, stent fracture and compression occurred regardless of the stent type, even though a vein does not pulsate. A study of the anatomical features of the iliac vein implies that bending, compression, and kink loads are applied to the iliac vein stents in vivo. For designing, developing, and pre-clinical testing of stents intended for use in the iliac vein, the above mechanical load environments induced by the anatomical features should be considered.

Preoperative mapping of the saphenous vein

DEFF Research Database (Denmark)

Levi-Mazloum, Niels Donald; Sillesen, H; Nielsen, Tina G

1995-01-01

A consecutive series of 92 patients had their greater saphenous vein assessed with duplex ultrasound scanning prior to planned infrainguinal bypass procedures. A naturally occurring optimal vein diameter was discovered. It was significantly correlated with higher postoperative ankle-brachial pres......-brachial pressure index (ABI) and lesser early postoperative thrombosis. A significant linear regression was found between the pre and postoperative vein diameter....

The CT appearance of the superior intercostal veins

International Nuclear Information System (INIS)

Lund, G.

1982-01-01

The CT appearance of the superior intercostal veins is described. The veins are more frequently seen on the right side. The right superior intercostal vein should not be misinterpreted as a paraspinal mass when it is large or bulges into the contour of the right lung. A case of stenosis of the left brachiocephalic vein is shown, where the left superior intercostal vein serves as a collateral. (orig.)

Balloon-occluded retrograde transvenous obliteration of gastric varix draining via the left inferior phrenic vein into the left hepatic vein

International Nuclear Information System (INIS)

Ibukuro, Kenji; Mori, Koichi; Tsukiyama, Toshitaka; Inoue, Yoshihiro; Iwamoto, Yukako; Tagawa, Kazumi

1999-01-01

We encountered a patient with gastric varix draining not via the usual left suprarenal vein but via the left inferior phrenic vein joining the left hepatic vein. Transfemoral balloon-occluded retrograde transvenous obliteration (BRTO) of the varix was performed under balloon occlusion of the left inferior phrenic vein via the left hepatic vein and retrograde injection of the sclerosing agent (5% of ethanolamine oleate) into the gastric varix. Disappearance of the gastric varix was confirmed on endoscopic examination 2 months later.

Thrombosed aneurysm of saphenous vein coronary artery bypass grafting

Energy Technology Data Exchange (ETDEWEB)

Queiroz, Rodolfo Mendes; Nastri Filho, Rogerio; Ferez, Marcus Antonio; Costa, Mauro Jose Brandao da; Laguna, Claudio Benedini; Valentin, Marcus Vinicius Nascimento, E-mail: rod_queiroz@hotmail.com [Documenta - Hospital Sao Francisco, Ribeirao Preto, SP (Brazil). Departamento de Radiologia e Diagnostico por Imagem; Hospital Sao Francisco, Ribeirao Preto, SP (Brazil). Centro de Terapia Intensiva

2017-06-15

We describe the case of a male patient, aged 76 years, referred for cardiac investigation due to retrosternal chest pain and dyspnea. He had a history of acute myocardial infarction and angioplasties in the last 30 years, including a saphenous vein coronary artery bypass grafting (SVCABG). Echocardiogram showed hypoechoic oval formation near the right ventricle, suggesting a pericardial cyst. Computed angiotomography revealed a predominantly fusiform and thrombosed aneurysmal dilation of the SVCABG to the right coronary artery. SVCABG aneurysms are very rare and potentially fatal. They usually appear in the late postoperative period, and patients are often asymptomatic. On radiography, it is frequently presented as enlargement of the mediastinum, with echocardiography, computed tomography and magnetic resonance imaging being very useful for diagnosis. Coronary angiography is the gold standard to detect these cases. Our report illustrates a rare situation arising late from a relatively common surgery. Due to its severity, proper recognition in the routine assessment of patients with a similar history is essential. (author)

Short-chain fatty acids production and microbial community in sludge alkaline fermentation: Long-term effect of temperature.

Science.gov (United States)

Yuan, Yue; Liu, Ye; Li, Baikun; Wang, Bo; Wang, Shuying; Peng, Yongzhen

2016-07-01

Sludge alkaline fermentation has been reported to achieve efficient short-chain fatty acids (SCFAs) production. Temperature played important role in further improved SCFAs production. Long-term SCFAs production from sludge alkaline fermentation was compared between mesotherm (30±2°C) and microtherm (15±2°C). The study of 90days showed that mesotherm led to 2.2-folds production of SCFAs as microtherm and enhanced the production of acetic acid as major component of SCFAs. Soluble protein and carbohydrate at mesotherm was 2.63-folds as that at microtherm due to higher activities of protease and α-glucosidase, guaranteeing efficient substrates to produce SCFAs. Illumina MiSeq sequencing revealed that microtherm increased the abundance of Corynebacterium, Alkaliflexus, Pseudomonas and Guggenheimella, capable of enhancing hydrolysis. Hydrolytic bacteria, i.e. Alcaligenes, Anaerolinea and Ottowia, were enriched at mesotherm. Meanwhile, acidogenic bacteria showed higher abundance at mesotherm than microtherm. Therefore, enrichment of functional bacteria and higher microbial activities resulted in the improved SCFAs at mesotherm. Copyright © 2016 Elsevier Ltd. All rights reserved.

Exploration for gold mineralization in the Arabo Nubian Shield: Using remote sensing Approach

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Ramadan, Talaat

2013-04-01

In the southern part of the Eastern Desert of Egypt, Landsat Thematic Mapper (ETM+) data and fieldwork was combined with mineralogical and geochemical investigations in order to detect and characterize alteration zones within Pan-African rocks. The processing of Landsat ETM+ data using ratioing (bands 5/7,5/1,4/3 in Red, Green, Blue) showed two different types of alteration zones (type l and 2). Type 1 is close to the ophiolitic ultramafic rocks and type 2 is located within island-arc related metavolcanic rocks at the study areas. Both of these alteration zones are concordant with the main NW-SE structural trend. Mineralogical studies indicate that the alteration zones of type 1 consist mainly of calcite, ankerite, magnesite, dolomite and quartz. Chromian spinel, pyrite, and Ni-bearing sulphides (gersdorffite, pentlandite and polydymite) are the main ore minerals within this zone. Alteration zones of type 2 are strongly potassium-enriched and pyrophyllite, kaolinite, illite, gypsum and quartz occur. The brecciated quartz-veins associated with theses alteration zones consist of quartz, Fe-hydroxides, hematite and native gold. The gold content reaches up to 5 g/t in the alteration zone, while it extends up to 50 g/t in the quartz veins. This study presents a mineralogical characterization of such zones and demonstrates the utility of orbital remote sensing for finding unknown alteration zones in the Eastern Desert and other arid areas with similar host rock lithologies.

Nature, diversity of deposit types and metallogenic relations of South China

Science.gov (United States)

Zaw, K.; Peters, S.G.; Cromie, P.; Burrett, C.; Hou, Z.

2007-01-01

the 'Northern Golden Triangle' of China. These deposits are mostly epigenetic hydrothermal micron-disseminated gold deposits with associated As, Hg, Sb + Tl mineralisation similar to Carlin-type deposits in USA. The important deposits in the Southern Golden Triangle are Jinfeng (Lannigou), Zimudang, Getang, Yata and Banqi in Guizhou Province, and the Jinya and Gaolong deposits in Guangxi District. The most important deposits in the Northern Golden Triangle are the Dongbeizhai and Qiaoqiaoshang deposits. Many porphyry-related polymetallic copper-lead-zinc and gold skarn deposits occur in South China. These deposits are related to Indosinian (Triassic) and Yanshanian (Jurassic to Cretaceous) magmatism associated with collision of the South China and North China Cratons and westward subduction of the Palaeo-Pacific Plate. Most of these deposits are distributed along the Lower to Middle Yangtze River metallogenic belt. The most significant deposits are Tonglushan, Jilongshan, Fengshandong, Shitouzui and Jiguanzui. Au-(Ag-Mo)-rich porphyry-related Cu-Fe skarn deposits are also present (Chengmenshan and Wushan in Jiangxi Province and Xinqiao, Mashan-Tianmashan, Shizishan and Huangshilaoshan in Anhui Province). The South China fold belt extending from Fujian to Zhejiang Provinces is characterised by well-developed Yanshanian intrusive to subvolcanic rocks associated with porphyry to epithermal type mineralisation and mesothermal vein deposits. The largest porphyry copper deposit in China, Dexing, occurs in Jiangxi Province and is hosted by Yanshanian granodiorite. The high-sulphidation epithermal system occurs at the Zijinshan district in Fujian Province and epithermal to mesothermal vein-type deposits are also found in the Zhejiang Province (e.g., Zhilingtou). Part of Shandong Province is located at the northern margin of the South China Craton and the province has unique world class granite-hosted orogenic gold deposits. Occurrences of Pt-Pd-Ni-Cu-Co are found in Permian

Vein Patch Closure Using Below the Knee Greater Saphenous Vein for Femoral Endarterectomy Procedures is Not Always a Safe Choice

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M. Berner

Full Text Available : Background: The complication of vein patch rupture is well described after carotid patch angioplasty; however, there is a paucity of data about the safety of vein patch closure in the setting of femoral endarterectomy. Methods/results: From May 2012 to May 2015, 115 femoral endarterectomies with patch closure were performed. A patch rupture occurred in three cases (2.6% with a mortality rate of 66% (2/3. In all cases the greater saphenous vein below the knee was used as patch material. Discussion/conclusion: Vein patches, particularly from small calibre veins, should be excluded in femoral endarterectomy procedures as they pose a substantial risk of rupture. Keywords: Angioplasty, Patch rupture, Femoral artery, Patch, Great saphenous vein

Varicose Veins: Role of Mechanotransduction of Venous Hypertension

Science.gov (United States)

Atta, Hussein M.

2012-01-01

Varicose veins affect approximately one-third of the adult population and result in significant psychological, physical, and financial burden. Nevertheless, the molecular pathogenesis of varicose vein formation remains unidentified. Venous hypertension exerted on veins of the lower extremity is considered the principal factor in varicose vein formation. The role of mechanotransduction of the high venous pressure in the pathogenesis of varicose vein formation has not been adequately investigated despite a good progress in understanding the mechanomolecular mechanisms involved in transduction of high blood pressure in the arterial wall. Understanding the nature of the mechanical forces, the mechanosensors and mechanotransducers in the vein wall, and the downstream signaling pathways will provide new molecular targets for the prevention and treatment of varicose veins. This paper summarized the current understanding of mechano-molecular pathways involved in transduction of hemodynamic forces induced by blood pressure and tries to relate this information to setting of venous hypertension in varicose veins. PMID:22489273

[Deep vein thrombosis prophylaxis.

Science.gov (United States)

Sandoval-Chagoya, Gloria Alejandra; Laniado-Laborín, Rafael

2013-01-01

Background: despite the proven effectiveness of preventive therapy for deep vein thrombosis, a significant proportion of patients at risk for thromboembolism do not receive prophylaxis during hospitalization. Our objective was to determine the adherence to thrombosis prophylaxis guidelines in a general hospital as a quality control strategy. Methods: a random audit of clinical charts was conducted at the Tijuana General Hospital, Baja California, Mexico, to determine the degree of adherence to deep vein thrombosis prophylaxis guidelines. The instrument used was the Caprini's checklist for thrombosis risk assessment in adult patients. Results: the sample included 300 patient charts; 182 (60.7 %) were surgical patients and 118 were medical patients. Forty six patients (15.3 %) received deep vein thrombosis pharmacologic prophylaxis; 27.1 % of medical patients received deep vein thrombosis prophylaxis versus 8.3 % of surgical patients (p < 0.0001). Conclusions: our results show that adherence to DVT prophylaxis at our hospital is extremely low. Only 15.3 % of our patients at risk received treatment, and even patients with very high risk received treatment in less than 25 % of the cases. We have implemented strategies to increase compliance with clinical guidelines.

Anomalous adrenal vein anatomy complicating the evaluation of primary hyperaldosteronism

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Kaitlin M. Ford, BS

2018-02-01

Full Text Available Adrenal vein development in utero occurs concurrently with the development of the inferior vena cava, the renal veins, and the gonadal veins. The embryologic formation of these veins involves communication of various venous systems. Although the left adrenal-renal vein complex is most commonly described as a shared emptying of the left adrenal vein and the left inferior phrenic vein into the left renal vein, there have been reports of numerous anatomic variations of this complex. In this report, we present a case of a rare variant of the left adrenal vein, in which the left adrenal vein empties into the left gonadal vein, which takes an atypical course superolateral to the left kidney.

On dynamics of uranium vein mineralization

International Nuclear Information System (INIS)

Petrosyan, R.V.

1981-01-01

The formation of urnaium vein deposits and the essence of consanguinity of the mineralization and wall metasomatites are considered. The formation of uranium mineralization is analysed from the positions of Korzhinsky D. S. : the formation of metasomatite aureole and associated vein ores take place as a result of the development of one solution flow while the formation of mineral vein associations occurs on the background of contineous filtration of the solution during metasomato is due to a repeated (pulse) half-opening of fractures and their filling with a part of filtrating solution. The analysis of the available information on the example of two different uranium manifestations permits to reveal certain relations both in the character of wall rock alterations and between the metasomatosis and the formation of ore minerals in veins. The conclusion is made that spatial-time correlations of vein formations with wall metasomatites attest that the pulse formation of ores in veinlets occurs on the background and in interrelation with a consecutive precipitation of components in the aureole volume. The analysis of element migration dynamics in wall aureole carried out from the positions of the Korzhinsky hypothesis of the advance wave of acid components that takes into account the interaction of continuous and pulse mechanisms of solution movement permits to avoid contradictions when interpreting the processes of wall rock alterations and vein ore-forming, and permits to make a common scheme of vein ore-genesis [ru

Determination of gold in gold ores

International Nuclear Information System (INIS)

Keedy, C.R.; Parson, L.; Shen, J.

1989-01-01

The gold content of placer gold flakes and gold bearing ores was determined by instrumental and radiochemical neutron activation analysis, respectively. It was discovered that significant errors result in the instrumental method for gold flakes as small as 10 mg due to sample self-absorption of neutrons during irradiation. Reliable results were obtained for both ore samples and gold flakes by dissolving the samples in aqua regia prior to irradiation. (author) 7 refs.; 3 tabs

A Morphological Insight of the Femoral Vein

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Ferreira AH

2015-10-01

Full Text Available A total of 13 cadavers (12 men and 1 women of different age group were used for the study with the purpose to determine the prevalence of femoral vein duplication. Lower limb regions (26 sides were carefully dissected as per the standard dissection procedure. Femoral vein (unitruncular was found in 96.15% of specimen. Bitruncular configurations (total bifidity was found in a male cadaver of 75 years of age (3.85%. In the right lower limb, 6.5 cms below the inguinal ligament the femoral vein - lateral ramus received the lateral circumflex femoral vein, and the medial circumflex femoral vein, and the lateral and medial ramii formed a common venous trunk. Knowledge of the truncular venous variations is important to recognize and avoid potential errors in diagnosis of deep venous thrombosis of the femoral vein, in the case of an occluded duplicated trunk.

Geological and geochemical implications of the genesis of the Qolqoleh orogenic gold mineralisation, Kurdistan Province (Iran)

Science.gov (United States)

Taghipour, Batoul; Ahmadnejad, Farhad

2015-03-01

The Qolqoleh gold deposit is located in the northwestern part of the Sanandaj-Sirjan Zone (SSZ), within the NE-SW trending Qolqoleh shear zone. Oligocene granitoids, Cretaceous meta-limestones, schists and metavolcanics are the main lithological units. Chondrite-normalised REE patterns of the ore-hosting metavolcanics indicate REE enrichment relative to hanging wall (chlorite-sericite schist) and footwall (meta-limestone) rocks. The pattern also reflects an enrichment in LREE relative to HREE. It seems that the LREE enrichment is related to the circulation of SO42- and CO2-bearing fluids and regional metamorphism in the Qolqoleh shear zone. Both positive and negative Eu anomalies are observed in shear-zone metavolcanics. These anomalies are related to the degree of plagioclase alteration during gold mineralisation and hydrothermal alteration. In progressing from a metavolcanic protomylonite to an ultramylonite, significant changes occurred in the major/trace element and REE concentration. Utilising an Al-Fe-Ti isocon for the ore-hosting metavolcanics shows that Sc, Y, K, U, P, and M-HREE (except Eu) are relatively unchanged; S, As, Ag, Au, Ca, LOI, Rb and LREE are enriched, and Sr, Ba, Eu, Cr, Co and Ni decrease with an increasing degree of deformation. Based on geochemical features and comparison with other well-known shear zones in the world, the study area is best classified as an Isovolume-Gain (IVG) type shear zone and orogenic type gold mineralisation. Based on the number of phases observed at room temperature and their microthermometric behaviour, three fluid inclusion types have been recognised in quartz-sulphide and quartz-calcite veins: Type I monophase aqueous inclusions, Type II two-phase liquid-vapour (L-V) inclusions which are subdivided into two groups based on the homogenisation temperature (Th): a) L-V inclusions with Th from 205 to 255°C and melting temperature of last ice (Tm) from -3 to -9°C. b) L-V inclusions with higher Th from 335 to 385�

Cavernous transformation of the portal vein

International Nuclear Information System (INIS)

Lehotska, V.; Dostalova, K.; Durkovsky, A.; Samal, V.

1995-01-01

In this contribution, the authors give an account of a rare case of a cavernous transformation of the portal vein that may have originated secondarily in a proliferative hematogenous disease with a polyglobulia and thrombosis in the periferal blood count as well as development of portal hypertension of a prehepatal type. The state of hyper-coagulation in a myeloproliferative disease may have lead to a chronic thrombosis of the portal vein with a subsequent malformation of the portal vein in terms of a cavernous transformation of the portal vein. The case is an interesting one because of the discrepancy between the gravity of the thrombotic complication and slightness of the symptoms in the clinical picture. The authors point out the importance of ultrasonography and computed tomography examination following the intravenous application of a water solution of a contrast medium in a morphologic diagnosing of a rare complication of a chronic thrombotic clot of the portal vein - the cavernous transformation. (authors)

Varicose Vein Treatment (Endovenous Ablation of Varicose Veins)

Science.gov (United States)

... associated veins. top of page What are the benefits vs. risks? Benefits No surgical incision is needed—only a small ... risk of infection. The chance of infection requiring antibiotic treatment appears to be less than one in ...

Preduodenal portal vein: its surgical significance.

Science.gov (United States)

Makey, D A; Bowen, J C

1978-11-01

Preduodenal portal vein is a rare anatomical variant which may be one of many anomalies in the neonate with duodenal "atresia." Preduodenal portal vein also may be an occasional finding in an adult undergoing biliary, gastric, or pancreatic surgery. Awareness and recognition of the anomaly are essential for the avoidance of injury during such operations. We report here a symptomless patient whose preduodenal portal vein was discovered at cholecystectomy.

Multimodal ultrasonographic assessment of leiomyosarcoma of the femoral vein in a patient misdiagnosed as having deep vein thrombosis: A case report.

Science.gov (United States)

Zhang, Mei; Yan, Feng; Huang, Bin; Wu, Zhoupeng; Wen, Xiaorong

2017-11-01

Primary leiomyosarcoma (LMS) of the vein is a rare tumor that arises from the smooth muscle cells of the vessel wall and has an extremely poor prognosis. This tumor can occur in vessels such as the inferior vena cava, great saphenous vein, femoral vein, iliac vein, popliteal vein, and renal vein; the inferior vena cava is the most common site. LMS of the femoral vein can result in edema and pain in the lower extremity; therefore, it is not easy to be differentiated from deep vein thrombosis (DVT). Moreover, virtually no studies have described the ultrasonographic features of LMS of the vein in detail. We present a case of a 55-year-old woman with LMS of the left femoral vein that was misdiagnosed as having deep vein thrombosis (DVT) on initial ultrasonographic examination. The patient began to experience edema and pain in her left leg seven months previously. She was diagnosed as having DVT on initial ultrasonographic examination, but the DVT treatment that she had received for 7 months failed to improve the status of her left lower limb. She subsequently underwent re-examination by means of a multimodal ultrasonographic imaging approach (regular B-mode imaging, color Doppler imaging, pulsed-wave Doppler imaging, contrast-enhanced ultrasonography), which confirmed a diagnosis of LMS. This patient was treated successfully with surgery. This case demonstrates that use of multiple ultrasonographic imaging techniques can be helpful to diagnose LMS accurately. Detection of vasculature in a dilated vein filled with a heterogeneous hypoechoic substance on ultrasonography is a sign of a tumor. The pitfall of misdiagnosing this tumor as DVT is a useful reminder.

Duplication of the Portal Vein: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang Won; Shin, Hyeong Cheol; Jou, Sung Shick; Han, Jong Kyu; Kim, Il Young [Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of)

2009-12-15

The duplication of the portal vein is an uncommon congenital anomaly. To date, only four cases have been reported in the medical literature. This anomaly can cause portal hypertension in pediatric patients. In addition, duplication of the portal vein has various patterns of connection with a splenic vein or mesenteric veins, and it can lie anterior or posterior to the duodenum. We report the MDCT findings of an adult patient with duplication of the portal vein that was found incidentally

Management of Post-Traumatic Phlegmasia Cerulea Dolens via Right-to-Left Femoral Vein to Femoral Vein Bypass (Palma Procedure).

Science.gov (United States)

Dua, Anahita; Heller, Jennifer; Lee, Cheong

2017-11-01

Phlegmasia cerulea dolens (PCD) is a rare condition resulting from venous occlusion that impairs arterial flow. We report a rare case of post-traumatic PCD after ligation of the iliac vein with successful treatment by right-to-left femoral vein to femoral vein bypass using left great saphenous vein (Palma procedure). The clinical presentation, diagnostic process, and approach to management along with a literature review on the operative management of PCD are presented in this case report.

Absent right superior caval vein in situs solitus

DEFF Research Database (Denmark)

Lytzen, Rebekka; Sundberg, Karin; Vejlstrup, Niels

2015-01-01

Introduction In up to 0.07% of the general population, the right anterior cardinal vein obliterates and the left remains open, creating an absent right superior caval vein and a persistent left superior caval vein. Absent right superior caval vein is associated with additional congenital heart...... disease in about half the patients. We wished to study the consequences of absent right superior caval vein as an incidental finding on prenatal ultrasonic malformation screening. Material and methods This is a retrospective case series study of all foetuses diagnosed with absent right superior caval vein...... no postnatal complications. All children were found to have healthy hearts at follow-up. CONCLUSIONS: In all cases, the findings proved to be a benign condition with no clinical manifestations or complications. Although isolated absent right superior caval vein does not seem to affect the outcome, associated...

Geological and Geochemical Criteria for the Estimation of the Area of The Lesser Hinggan for the Endogenous Gold Mineralization (The Far East, Russia)

Science.gov (United States)

Yurchenko, Yuriy

2015-04-01

intergrown with quartz, pyrite, arsenopyrite, galena in areas of intensive dislocation metamorphism and quartz-vein formation, accompanied by hydrothermal-metasomatic alteration of the bedrock in the mineral facies propylite, beresites and argillisites; 4. The transition some alluvial gold from lowland to the talus slope approaching the watershed areas; 5. The structural-geological similarity the area of the Lesser Hinggan with the gold mining areas of China and the northwestern part (Russia) of the Bureya array (Tandzhigou (Juanjiegou) (China), Noninskoe (Russia), Prognoznoe (Russia) and others). The Projected endogenous gold mineralization on the Lesser Hinggan include gold-quartz (including low-sulfide component) ore-formation type in the form of thin and not sustain the strike quartz veins in the surrounding strata (for example, gold deposit Lysoya Gora) and genetically related to the Early Cretaceous Hinggan-Olonoy complex of the subvolcanic felsic small intrusions . The ore-formation types associated with gold-bearing weathering crusts, carbon ("black") schist and ferruginous quartzite are the perspective in the area of the Lesser Hinggan also.

Finger vein extraction using gradient normalization and principal curvature

Science.gov (United States)

Choi, Joon Hwan; Song, Wonseok; Kim, Taejeong; Lee, Seung-Rae; Kim, Hee Chan

2009-02-01

Finger vein authentication is a personal identification technology using finger vein images acquired by infrared imaging. It is one of the newest technologies in biometrics. Its main advantage over other biometrics is the low risk of forgery or theft, due to the fact that finger veins are not normally visible to others. Extracting finger vein patterns from infrared images is the most difficult part in finger vein authentication. Uneven illumination, varying tissues and bones, and changes in the physical conditions and the blood flow make the thickness and brightness of the same vein different in each acquisition. Accordingly, extracting finger veins at their accurate positions regardless of their thickness and brightness is necessary for accurate personal identification. For this purpose, we propose a new finger vein extraction method which is composed of gradient normalization, principal curvature calculation, and binarization. As local brightness variation has little effect on the curvature and as gradient normalization makes the curvature fairly uniform at vein pixels, our method effectively extracts finger vein patterns regardless of the vein thickness or brightness. In our experiment, the proposed method showed notable improvement as compared with the existing methods.

Adventitial cystic disease of the common femoral vein presenting as deep vein thrombosis

Directory of Open Access Journals (Sweden)

Young-Kyun Kim

2016-07-01

Full Text Available Adventitial cystic disease of the common femoral vein is a rare condition. We herein report the case of a 50-year-old woman who presented with painless swelling in her left lower leg that resembled deep vein thrombosis. She underwent femoral exploration and excision of the cystic wall. The presentation, investigation, treatment, and pathology of this condition are discussed with a literature review.

Evidence for de-sulfidation to form native electrum in the Fire Creek epithermal gold-silver deposit, north-central Nevada

Science.gov (United States)

Perez, J.; Day, J. M.; Cook, G. W.

2012-12-01

The Fire Creek property is a newly developed and previously unstudied epithermal Au-Ag deposit located in the Northern Shoshone range of north central Nevada. The mineralization occurs within and above en echelon N-NW trending basaltic dykes that are hosted within a co-genetic and bimodal suite of mid-Miocene basalts and andesites formed in association with the Yellowstone hotspot-track. Previous studies of Au-Ag mineralization in the Great Basin have focused primarily on extensively mined and/or low-grade deposits. Therefore, the ability for unrestricted sampling of a major Au-Ag deposit early in its exploration and development represents an opportunity for refined understanding of epithermal ore genesis processes. New petrology reveals at least two distinct pulses of mineralization that in relative order of timing are: 1) S-rich veins which are associated with initial host-rock alteration; 2) quartz- and/or calcite-rich veins which vary from fine-grained to lath-like quartz crystals with large calcite crystals in vein centers. Native electrum occurs only within the second phase of mineralization and typically occurs within quartz and adjacent to cross-cut first-phase S-rich veins. In places the electrum appears to replace or form overgrowths around existing sulfide phases. High levels of gold and silver are found in both the first (0.8 g Au/tonne) and second-phase pulses (37 g Au/tonne). Fire Creek shares many similarities with its northern neighbor, the Mule Canyon Au-Ag deposit, with high Fe sulfide contents for some of the ores, altered wall-rocks and the presence of narrow and discontinuous gold-bearing siliceous veins. Like Fire Creek, Mule Canyon possesses two distinct mineralizing phases, a sulfide rich and a late stage calcite/silica assemblage. The first pulse appears to be identical in both locations with a variation of disseminated to euhedral iron-sulfides and associated intense alteration of host rock. However, Fire Creek differs from Mule Canyon in

Augmented reality based real-time subcutaneous vein imaging system.

Science.gov (United States)

Ai, Danni; Yang, Jian; Fan, Jingfan; Zhao, Yitian; Song, Xianzheng; Shen, Jianbing; Shao, Ling; Wang, Yongtian

2016-07-01

A novel 3D reconstruction and fast imaging system for subcutaneous veins by augmented reality is presented. The study was performed to reduce the failure rate and time required in intravenous injection by providing augmented vein structures that back-project superimposed veins on the skin surface of the hand. Images of the subcutaneous vein are captured by two industrial cameras with extra reflective near-infrared lights. The veins are then segmented by a multiple-feature clustering method. Vein structures captured by the two cameras are matched and reconstructed based on the epipolar constraint and homographic property. The skin surface is reconstructed by active structured light with spatial encoding values and fusion displayed with the reconstructed vein. The vein and skin surface are both reconstructed in the 3D space. Results show that the structures can be precisely back-projected to the back of the hand for further augmented display and visualization. The overall system performance is evaluated in terms of vein segmentation, accuracy of vein matching, feature points distance error, duration times, accuracy of skin reconstruction, and augmented display. All experiments are validated with sets of real vein data. The imaging and augmented system produces good imaging and augmented reality results with high speed.

Personal authentication through dorsal hand vein patterns

Science.gov (United States)

Hsu, Chih-Bin; Hao, Shu-Sheng; Lee, Jen-Chun

2011-08-01

Biometric identification is an emerging technology that can solve security problems in our networked society. A reliable and robust personal verification approach using dorsal hand vein patterns is proposed in this paper. The characteristic of the approach needs less computational and memory requirements and has a higher recognition accuracy. In our work, the near-infrared charge-coupled device (CCD) camera is adopted as an input device for capturing dorsal hand vein images, it has the advantages of the low-cost and noncontact imaging. In the proposed approach, two finger-peaks are automatically selected as the datum points to define the region of interest (ROI) in the dorsal hand vein images. The modified two-directional two-dimensional principal component analysis, which performs an alternate two-dimensional PCA (2DPCA) in the column direction of images in the 2DPCA subspace, is proposed to exploit the correlation of vein features inside the ROI between images. The major advantage of the proposed method is that it requires fewer coefficients for efficient dorsal hand vein image representation and recognition. The experimental results on our large dorsal hand vein database show that the presented schema achieves promising performance (false reject rate: 0.97% and false acceptance rate: 0.05%) and is feasible for dorsal hand vein recognition.

Thrombosis of right ovarian vein

International Nuclear Information System (INIS)

Forner, J.; Talens, A.; Flores, M.; Mendez, M.

2001-01-01

Ovarian vein thrombosis is a rare postpartum complication (0.1%). It can be fatal, since it can lead to sepsis, pulmonary thromboembolisms and inferior vena cava or renal vein thrombosis. Computed tomography and magnetic resonance imaging are the techniques of choice for its diagnosis, while the value of ultrasound is limited due to its low sensitivity and specificity. We report the case of a woman who, during puerperium, developed thrombosis of right ovarian vein that presented clinical, ultrasonographic and computed tomographic features of appendicitis. We describe the radiological sings and stress the fact that this diagnosis should be suspected in puerperal women. (Author) 9 refs

Assessment and management of patients with varicose veins.

Science.gov (United States)

Allen, Louise

Varicose veins are enlarged superficial veins found in the legs. This article explores the anatomy and physiology of the venous system to assist nurses to assess, manage and treat patients with varicose veins.

Biosynthesis of gold nanoparticles using diatoms-silica-gold and EPS-gold bionanocomposite formation

OpenAIRE

Schröfel, Adam; Kratošová, Gabriela; Bohunická, Markéta; Dobročka, Edmund; Vávra, Ivo

2011-01-01

Novel synthesis of gold nanoparticles, EPS-gold, and silica-gold bionanocomposites by biologically driven processes employing two diatom strains (Navicula atomus, Diadesmis gallica) is described. Transmission electron microscopy (TEM) and electron diffraction analysis (SAED) revealed a presence of gold nanoparticles in the experimental solutions of the diatom culture mixed with tetrachloroaureate. Nature of the gold nanoparticles was confirmed by X-ray diffraction studies. Scanning electron m...

Deep vein thrombosis: a clinical review

Directory of Open Access Journals (Sweden)

Kesieme EB

2011-04-01

Full Text Available Emeka Kesieme1, Chinenye Kesieme2, Nze Jebbin3, Eshiobo Irekpita1, Andrew Dongo11Department of Surgery, Irrua Specialist Teaching Hospital, Irrua, Nigeria; 2Department of Paediatrics, Irrua Specialist Teaching Hospital, Irrua, Nigeria; 3Department of Surgery, University of Port Harcourt Teaching Hospital, Port-Harcourt, NigeriaBackground: Deep vein thrombosis (DVT is the formation of blood clots (thrombi in the deep veins. It commonly affects the deep leg veins (such as the calf veins, femoral vein, or popliteal vein or the deep veins of the pelvis. It is a potentially dangerous condition that can lead to preventable morbidity and mortality.Aim: To present an update on the causes and management of DVT.Methods: A review of publications obtained from Medline search, medical libraries, and Google.Results: DVT affects 0.1% of persons per year. It is predominantly a disease of the elderly and has a slight male preponderance. The approach to making a diagnosis currently involves an algorithm combining pretest probability, D-dimer testing, and compression ultrasonography. This will guide further investigations if necessary. Prophylaxis is both mechanical and pharmacological. The goals of treatment are to prevent extension of thrombi, pulmonary embolism, recurrence of thrombi, and the development of complications such as pulmonary hypertension and post-thrombotic syndrome.Conclusion: DVT is a potentially dangerous condition with a myriad of risk factors. Prophylaxis is very important and can be mechanical and pharmacological. The mainstay of treatment is anticoagulant therapy. Low-molecular-weight heparin, unfractionated heparin, and vitamin K antagonists have been the treatment of choice. Currently anticoagulants specifically targeting components of the common pathway have been recommended for prophylaxis. These include fondaparinux, a selective indirect factor Xa inhibitor and the new oral selective direct thrombin inhibitors (dabigatran and selective

Dual Balloon-Occluded Retrograde Transvenous Obliteration of Gastric Varix Draining into the Left Adrenal Vein and Left Inferior Phrenic Vein

International Nuclear Information System (INIS)

Nishida, Norifumi; Ninoi, Teruhisa; Kitayama, Toshiaki; Yamamoto, Akira; Sakai, Yukimasa; Sato, Kimihiko; Hamuro, Masao; Nakamura, Kenji; Inoue, Yuichi; Yamada, Ryusaku

2004-01-01

A 66-year-old woman with a gastric varix, draining into a dilated left adrenal vein and a left inferior phrenic vein, was treated with dual balloon-occluded retrograde transvenous obliteration (B-RTO). Under balloon occlusion of the left adrenal vein and the left inferior phrenic vein, retrograde injection of a sclerosant (5% ethanolamine oleate) into the gastric varix was performed. Two weeks later, disappearance of flow in the gastric varix was confirmed on endoscopic ultrasound examination

The Tintina Gold Belt - A global perspective

Science.gov (United States)

Goldfarb, Richard J.; Hart, Craig J.R.; Miller, Marti L.; Miller, Lance D.; Farmer, G. Lang; Groves, David I.; Tucker, Terry L.; Smith, Moira T.

2000-01-01

The so-called Tintina Gold Belt extends for more than 1000 km along the length of the northern North American Cordillera. Middle to Late Cretaceous Au deposits within the belt have various similar characteristics, among which are a spatial and temporal association with magmatism; Bi-W-Te signatures in deposits hosted by granitod stocks and As-Sb signatures where hosted by sedimentary rocks and dyke systems; and δ180 values consistently > 12 per mil for Au-bearing quartz. Nevertheless significant differences in structural styles, levels of deposit emplacement, ore-fluid chemistry, and Au grades suggest that the characteristics represent a broad range of deposit types. Many of these are best classified as orogenic Au deposits in the Yukon-Tanana terrane, as epithermal and porphyry-style Au deposits in the Kuskokwim region, and as Au-bearing, granite-related veins and stockworks, replacements, and skarns, as well as associated polymetallic lodes, in central Yukon. The diverse types of Au deposits and associated plutons of the Tintina Gold Belt collectively define a 45-m.y.-long period of arc magmatism that migrated northwesterly, for about 1000 km, across the active collisional margin of Cretaceous northwestern North America. The initiation of fluid flow and plutonism in Albian time seems to correlate with the onset of oblique subduction and dextral strike-slip on the Denali-Farewell, Tintina-Kaltag, and related fault systems. Initial Au-vein formation and subduction-related magmatism at about 115-110 Ma (e.g., including the Goodpaster and Fortymile districts), within the seaward side of the Yukon-Tanana terrane, correlate with the arrival of the Wrangellia superterrane off the continental margin. Dextral translation of the allochthonous Wrangellia block was associated with the migration of the thermal pulse to the northwest at about 95-90 Ma. Orogenic (or so­ called mesotherrnal) and granitoid-related Au deposits formed across the width of the Yukon

Recurrence of superficial vein thrombosis in patients with varicose veins.

Science.gov (United States)

Karathanos, Christos; Spanos, Konstantinos; Saleptsis, Vassileios; Tsezou, Aspasia; Kyriakou, Despina; Giannoukas, Athanasios D

2016-08-01

To investigate which factors other than history of superficial vein thrombosis (SVT) are associated with recurrent spontaneous SVT episodes in patients with varicose veins (VVs). Patients with a history of spontaneous SVT and VVs were followed up for a mean period of 55 months. Demographics, comorbidities, and thrombophilia screening test were analyzed. Patients were grouped according to the clinical-etiology-anatomy-pathophysiology classification. A multiple logistic regression analysis with the forward likelihood ratio method was undertaken. Thirteen patients out of 97 had a recurrence SVT episode during the follow-up period. All those patients were identified to have a thrombophilia defect. Protein C and S, antithrombin, and plasminogen deficiencies were more frequently present in patients without recurrence. Gene mutations were present in 38% in the nonrecurrence group and 77% in the recurrence group. After logistic regression analysis, patients with dislipidemia and mutation in prothrombin G20210A (FII) had an increased risk for recurrence by 5.4-fold and 4.6-fold, respectively. No deep vein thrombosis or pulmonary embolism occurred. Dislipidemia and gene mutations of F II are associated with SVT recurrence in patients with VVs. A selection of patients may benefit from anticoagulation in the short term and from VVs intervention in the long term. © The Author(s) 2015.

Endovenous mechanochemical ablation of great saphenous vein incompetence using the ClariVein device: a safety study

NARCIS (Netherlands)

Eekeren, R. van; Boersma, D.; Elias, S.; Holewijn, S.; Werson, D.A.; Vries, J.P. de; Reijnen, M.M.P.J.

2011-01-01

PURPOSE: To evaluate the feasibility and safety of endovenous mechanochemical ablation (MOCA) for the treatment of great saphenous vein (GSV) incompetence. METHODS: The newly developed ClariVein device uses a technique that combines mechanical endothelial damage using a rotating wire with the

Gd-DTPA-enhanced MR venography for varicose veins of the calf

International Nuclear Information System (INIS)

Kohata, Yoshiko; Naito, Akira; Ito, Katuhide.

1995-01-01

2D time-of-flight MR venography (2D TOF MRV) was performed in 16 patients (25 calves) with varicose veins and 2 volunteers (4 calves), and compared with venography. Sequential SPGR (TR/TE/FA=45 ms/7 ms/60deg) transverse images and/or GRASS (TR/TE/FA=100 ms/13 ms/60deg) transverse images were obtained for MRV. Superior presaturation pulse (S-SAT) was placed in 21 calves, and 0.05 mmol/kg Gd-DTPA was used in all calves. Projection MRVs were generated with maximum intensity projection (MIP) reconstruction. Regarding sequence parameter, S-SAT was useful to eliminate signal from artery that would obscure the signal of deep veins. The detectability of deep veins was improved with the use of S-SAT. In the comparison with venography, MRV could more clearly demonstrate varicose veins more than 5 mm in diameter and their drainage veins than venography. But it could not so clearly demonstrate deep veins as venography. It could not detect fine varicose veins less than 5 mm in diameter and connecting veins with valve insufficiency. In the examination of varicose veins, detection of deep veins, large varicose veins and their main drainage veins is clinically important, because diagnosis of patency of deep veins and dilatation of the drainage veins is necessary to choose the treatment, concluding conservative therapy, stripping and sclerotherapy. However, detection of fine varicose veins and connecting veins are not so important because those veins seldom need treatment. MRV was not so suitable for detection of deep veins, but very useful for detection of varicose veins more than 5 mm in diameter and their main drainage veins. In conclusion, MRV is non-invasive and effective method in varicose veins of calf, and it can take the place of venography with the improvement of deep vein detectability. (author)

Leiomyosarcoma of the renal vein

Directory of Open Access Journals (Sweden)

Lemos Gustavo C.

2003-01-01

Full Text Available Leiomyosarcoma of the renal vein is a rare tumor of complex diagnosis. We presented a case of renal vein leiomyosarcoma detected in a routine study. The primary treatment was complete surgical removal of the mass. In cases where surgical removal is not possible the prognosis is poor, with high rates of local recurrence and distant spread.

Geochemical Peculiarities of Galena and Sphalerite from Polymetallic Deposits of the Dal'negorskii Ore Region (Primorsky Krai, Russia)

Science.gov (United States)

Rogulina, L. I.; Moiseenko, V. G.; Ponomarchuk, V. A.

2018-04-01

New data on the composition of the major minerals from the skarn and vein polymetallic deposits of the Dal'negorskii ore region are reported. Analysis of galena and sphalerite was carried out by the X-ray fluorescent energy-dispersive method of synchrotron radiation for the first time. It is shown that the minor elements in major minerals of different deposits are typomorphic. Among these elements are Fe, Cu, Ni, Cd, Ag, Sn, and Sb, as well as In in sphalerite and Te in galena. The high concentrations of Ag, Cu, Te, Cd, and In in the extracted minerals indicate the complex character of mineralization. The compositional patterns of ore minerals characterize the sequence of mineral formation from the skarn to vein ores, and the sequence of deposits from the mesothermal to epithermal conditions. This provides geochemical evidence for the stage model of the formation of mineralization in the Dal'negorskii ore region.

Petrology, chronology and sequence of vein systems: Systematic magmatic and hydrothermal history of a major intracontinental shear zone, Canadian Appalachians

Science.gov (United States)

Pe-Piper, Georgia; Piper, David J. W.; McFarlane, Chris R. M.; Sangster, Chris; Zhang, Yuanyuan; Boucher, Brandon

2018-04-01

Intra-continental shear zones developed during continental collision may experience prolonged magmatism and mineralization. The Cobequid Shear Zone formed part of a NE-SW-trending, orogen-parallel shear system in the late Devonian-early Carboniferous, where syn-tectonic granite-gabbro plutons and volcanic rocks 4 km thick were progressively deformed. In late Carboniferous to Permian, Alleghanian collision of Africa with Laurentia formed the E-W trending Minas Fault Zone, reactivating parts of the Cobequid Shear Zone. The 50 Ma history of hydrothermal mineralization following pluton emplacement is difficult to resolve from field relationships of veins, but SEM study of thin sections provides clear detail on the sequence of mineralization. The general paragenesis is: albite ± quartz ± chlorite ± monazite → biotite → calcite, allanite, pyrite → Fe-carbonates, Fe-oxides, minor sulfides, calcite and synchysite. Chronology was determined from literature reports and new U-Pb LA-ICPMS dating of monazite and allanite in veins. Vein mineralization was closely linked to magmatic events. Vein emplacement occurred preferentially during fault movement recognised from basin-margin inversion, as a result of fractures opening in the damage zone of master faults. The sequence of mineralization, from ca. 355 Ma riebeckite and albite veins to ca. 327 (-305?) Ma siderite-magnetite and sulfide mineralization, resembles Precambrian iron-oxide-copper-gold (IOCG) systems in the literature. The abundant magmatic Na, halogens and CO2 in veins and some magmatic bodies, characteristic of IOCG systems, were derived from the deeply subducted Rheic Ocean slab with little terrigenous sediment. Regional extension of the Magdalen Basin caused asthenospheric upwelling and melting of the previously metasomatized sub-continental lithospheric mantle. Crustal scale strike-slip faulting facilitated the rise of magmas, resulting in high heat flow driving an active hydrothermal system. Table S2

Ultrasound assessment of great saphenous vein insufficiency

Directory of Open Access Journals (Sweden)

Chander RK

2015-06-01

Full Text Available Rajiv K Chander,1 Thomas S Monahan1,2 1Section of Vascular Surgery, Department of Surgery, University of Maryland School of Medicine, 2Department of Surgery, Baltimore Veterans Affairs Medical Center, Baltimore, MD, USA Abstract: Duplex ultrasonography is the ideal modality to assess great saphenous vein insufficiency. Duplex ultrasonography incorporates both gray scale images to delineate anatomy and color-Doppler imaging that visualizes the flow of blood in a structure. Assessment of great saphenous vein requires definition of the anatomy, augmentation of flow, evaluation for both superficial and deep vein thrombosis, and determining the presence of reflux. Currently, evolution in the treatment of reflux also relies on ultrasound for the treatment of the disease. Understanding the utilization of the ultrasound for the diagnosis and treatment of greater saphenous vein reflux is important for practitioners treating reflux disease. Keywords: duplex ultrasonography, small saphenous vein 

Gonadal vein tumor thrombosis due to renal cell carcinoma

Directory of Open Access Journals (Sweden)

Hamidreza Haghighatkhah

2015-01-01

Full Text Available Renal cell carcinoma (RCC had a tendency to extend into the renal vein and inferior vena cava, while extension into the gonadal vein has been rarely reported. Gonadal vein tumor thrombosis appears as an enhancing filling defect within the dilated gonadal vein anterior to the psoas muscle and shows an enhancement pattern identical to that of the original tumor. The possibility of gonadal vein thrombosis should be kept in mind when looking at an imaging study of patients with RCC

Identifikasi Pepper vein yellows virus yang Berasosiasi dengan Penyakit Yellow Vein Banding pada Tanaman Mentimun di Bali

Directory of Open Access Journals (Sweden)

I Dewa Nyoman Nyana

2016-11-01

Full Text Available Yellowing vein banding disease has been reported infecting cucurbit plants in Bali since 2014. Similar vein banding symptom on chilli pepper was observed previously, and early diagnosis indicated infection of Polerovirus. The objective of this research was to confirm the presence of Polerovirus infection on cucumber plant showing yellow vein banding symptom in Bali. Reverse transcription polymerase chain reaction – based detection method was conducted using specific primer pairs PeVYV-CP-F-BamH1/ PeVYV-CP-R-Pst1followed by sequencing and nucleotide sequence analysis.  Specific DNA fragments of ± 650 bp was successfully amplified from field samples.  Nucleotide sequence analysis showed that the sequence has the highest similarity > 95% with Pepper vein yellow virus (PeVYV infecting chili pepper from Indonesia (Bali, and Rembang, Japan, and Greece.

Endovascular management for significant iatrogenic portal vein bleeding.

Science.gov (United States)

Kim, Jong Woo; Shin, Ji Hoon; Park, Jonathan K; Yoon, Hyun-Ki; Ko, Gi-Young; Gwon, Dong Il; Kim, Jin Hyoung; Sung, Kyu-Bo

2017-11-01

Background Despite conservative treatment, hemorrhage from an intrahepatic branch of the portal vein can cause hemodynamic instability requiring urgent intervention. Purpose To retrospectively report the outcomes of hemodynamically significant portal vein bleeding after endovascular management. Material and Methods During a period of 15 years, four patients (2 men, 2 women; median age, 70.5 years) underwent angiography and embolization for iatrogenic portal vein bleeding. Causes of hemorrhage, angiographic findings, endovascular treatment, and complications were reported. Results Portal vein bleeding occurred after percutaneous liver biopsy (n = 2), percutaneous radiofrequency ablation (n = 1), and percutaneous cholecystostomy (n = 1). The median time interval between angiography and percutaneous procedure was 5 h (range, 4-240 h). Common hepatic angiograms including indirect mesenteric portograms showed active portal vein bleeding into the peritoneal cavity with (n = 1) or without (n = 2) an arterioportal (AP) fistula, and portal vein pseudoaneurysm alone with an AP fistula (n = 1). Successful transcatheter arterial embolization (n = 2) or percutaneous transhepatic portal vein embolization (n = 2) was performed. Embolic materials were n-butyl cyanoacrylate alone (n = 2) or in combination with gelatin sponge particles and coils (n = 2). There were no major treatment-related complications or patient mortality within 30 days. Conclusion Patients with symptomatic or life-threatening portal vein bleeding following liver-penetrating procedures can successfully be managed with embolization.

Scattering properties of vein induced localized surface plasmon resonances on a gold disk

KAUST Repository

Amin, Muhammad

2011-12-01

It is demonstrated via simulations that a gold nano-disk with a non-concentric cavity supports localized surface plasmon resonances over a frequency band that includes the visible and the near-infrared parts of the spectrum. The charge distribution on the disk indicates that the two distinct peaks in the scattering cross section are due to the (hybridized) higher-order plasmon modes; plasmon hybridization that involves the dipole modes of the disk and the cavity enforces the "coupling" of the plane-wave excitation to the originally-dark higher-order modes. It is further demonstrated that the resonance frequencies can be tuned by varying the radius of the embedded non-concentric cavity. The near-field enhancement observed at these two tunable resonance frequencies suggests that the proposed structure can be used as a substrate in surface enhanced spectroscopy applications. © 2011 IEEE.

Gold deposits in the Xiaoqinling-Xiong'ershan region, Qinling mountains, central China

Science.gov (United States)

Mao, J.; Goldfarb, R.J.; Zhang, Z.; Xu, W.; Qiu, Yumin; Deng, J.

2002-01-01

The gold-rich Xiaoqinling-Xiong'ershan region in eastern Shaanxi and western Henan provinces, central China, lies about 30-50 km inland of the southern margin of the North China craton. More than 100 gold deposits and occurrences are concentrated in the Xiaoqinling (west), Xiaoshan (middle), and Xiong'ershan (east) areas. Late Archean gneiss of the Taihua Group, and Middle Proterozoic metavolcanic rocks of the Xiong'er Group are the main host rocks for the deposits. Mesozoic granitoids (ca. 178-104 Ma) are present in most gold districts, but deposits are typically hosted in the Precambrian basement rocks hundreds of meters to as far as 10 km from the intrusions and related hornfels zones. Deposits in the Xiaoqinling and Xiaoshan areas are best classified as orogenic gold deposits, with ores occurring in a number of distinct belts both in quartz veins and disseminated in altered metamorphic rocks. Alteration assemblages are dominated by quartz, sericite, pyrite, and carbonate minerals. The ore-forming fluids were low salinity, CO2-rich, and characterized by isotopically heavy ??18O. Four deposits (Dongchuang, Wenyu, Yangzhaiyu, and Dahu) in the Xiaoqinling area each contain resources of about 1 Moz Au. Some of the gold deposits in the Xiong'ershan area represent more shallowly emplaced tellurium-enriched orogenic systems, which include resources of approximately 1-1.5 Moz Au at Shanggong and Beiling (or Tantou). Others are epithermal deposits (e.g., Qiyugou and Dianfang) that are hosted in volcanic breccia pipes. Isotopic dates for all gold deposits, although often contradictory, generally cluster between 172-99 Ma and are coeval with emplacement of the post-kinematic granitoids. The gold deposits formed during a period of relaxation of far-field compressional stresses, clearly subsequent to the extensive Paleozoic-early Mesozoic accretion of are terranes and the Yangtze craton onto the southern margin of the North China craton. Hydrothermal and magmatic events

Conventional tomographic hilar anatomy emphasizing the pulmonary veins

International Nuclear Information System (INIS)

Genereux, G.P.

1983-01-01

The pulmonary hili are a frequent site of interpretive uncertainty because of thir complex anatomy. The right hilar shadow relates primarily to the ascending and descending pulmonary arteries and the right superior pulmonary vein, whereas the left hilar density accrues from the left pulmonary artery, left descending pulmonary artery, and left superior pulmonary vein. The right and left superoir pulmonary veins are intimately associated with and inseparable from the arteries. Knowledge of the course of these veins facilitates their identification on conventional tomograms. The right and left inferior pulmonary veins lie behind the lower hili and contribute only a small increment to the normal hilar density; the horizontal course of these vessels readily distinguishes them from the vertically oriented lower lobe arteries. Prominence of both the right and left superior and inferior veins may cause hilar pseudotumors. Conventional tomograms are most helpful in understanding plain radiographs. A multiview approach in anteroposterior, 55 0 posterior oblique, and lateral projections is recommended for a complete assessment. Computed tomography in transaxial sections adds further understanding of spatial relations in the hili, including the contributions of the pulmonary veins

Evaluation of the portal veins, hepatic veins and bile ducts using fat-suppressed segmented True FISP

International Nuclear Information System (INIS)

Ueda, Takashi; Uchikoshi, Masato; Imaoka, Izumi; Iwaya, Kazuo; Matsuo, Michimasa; Wada, Akihiko

2005-01-01

True FISP (fast imaging with steady-state free precession) is a fast imaging technique that provides high SNR (signal to noise ratio) and excellent delineation of parenchymal organs. The contrast of True FISP depends on the mixture of T 2 /T 1 . Vessels with slow flow are usually displayed as high signal intensity on True FISP images. The purpose of this study was to optimize fat-suppressed (FS) segmented True FISP imaging for portal veins, hepatic veins, and bile ducts. FS segmented True FISP images were applied to the phantoms of liver parenchyma, saline, and oil with various flip angles (every 10 degrees from 5-65 degrees) and k-space segmentations (3, 15, 25, 51, 75, 99). Five healthy volunteers were also examined to get optimized flip angle and k-space segmentation. The largest flip angle, 65 degrees, showed the best contrast between the liver parenchyma phantom, saline, and oil. The largest segmentations, 99, provided the best contrast between a liver parenchyma phantom and saline. However, the signal of the oil phantom exceeded that of the liver parenchyma phantom with 99 segmentations. As a result, the flip angle of 65 degrees and 75 segments is recommended to get the best contrast between the liver parenchyma phantom and saline, while suppressing the signal of oil. The volunteer studies also support the phantom studies and showed excellent anatomical delineation of portal veins, hepatic veins, and bile ducts when using these parameters. We conclude that True FISP is potentially suitable for the imaging of portal veins, hepatic veins, and bile ducts. The flip angle of 65 degrees with 75 segments is recommended to optimize FS segmented True FISP images. (author)

Paleozoic–early Mesozoic gold deposits of the Xinjiang Autonomous Region, northwestern China

Science.gov (United States)

Rui, Zongyao; Goldfarb, Richard J.; Qiu, Yumin; Zhou, T.; Chen, R.; Pirajno, Franco; Yun, Grace

2002-01-01

border and the epithermal and replacement deposits of the Kanggurtag belt to the east in the Chol Tagh range. Gold deposits of approximately the same age in the Yili block include the Axi hot springs/epithermal deposit near the Kazakhstan border and a series of small orogenic gold deposits south of Urumqi (e.g. Wangfeng). Gold-rich porphyry copper deposits (e.g. Tuwu) define important new exploration targets in the northern Tian Shan of Xinjiang. The northern foothills of the Kunlun Shan of southern Xinjiang host scattered, small placer gold deposits. Sources for the gold have not been identified, but are hypothesized to be orogenic gold veins beneath the icefields to the south. They are predicted to have formed in the Tianshuihai terrane during its early Mesozoic accretion to the amalgamated Tarim–Qaidam–Kunlun cratonic block.

Generating and analyzing synthetic finger vein images

OpenAIRE

Hillerström, Fieke; Kumar, Ajay; Veldhuis, Raymond N.J.

2014-01-01

Abstract: The finger-vein biometric offers higher degree of security, personal privacy and strong anti-spoofing capabilities than most other biometric modalities employed today. Emerging privacy concerns with the database acquisition and lack of availability of large scale finger-vein database have posed challenges in exploring this technology for large scale applications. This paper details the first such attempt to synthesize finger-vein images and presents analysis of synthesized images fo...

Endovascular Radiofrequency Ablation for Varicose Veins

Science.gov (United States)

2011-01-01

Executive Summary Objective The objective of the MAS evidence review was to conduct a systematic review of the available evidence on the safety, effectiveness, durability and cost–effectiveness of endovascular radiofrequency ablation (RFA) for the treatment of primary symptomatic varicose veins. Background The Ontario Health Technology Advisory Committee (OHTAC) met on August 26th, 2010 to review the safety, effectiveness, durability, and cost-effectiveness of RFA for the treatment of primary symptomatic varicose veins based on an evidence-based review by the Medical Advisory Secretariat (MAS). Clinical Condition Varicose veins (VV) are tortuous, twisted, or elongated veins. This can be due to existing (inherited) valve dysfunction or decreased vein elasticity (primary venous reflux) or valve damage from prior thrombotic events (secondary venous reflux). The end result is pooling of blood in the veins, increased venous pressure and subsequent vein enlargement. As a result of high venous pressure, branch vessels balloon out leading to varicosities (varicose veins). Symptoms typically affect the lower extremities and include (but are not limited to): aching, swelling, throbbing, night cramps, restless legs, leg fatigue, itching and burning. Left untreated, venous reflux tends to be progressive, often leading to chronic venous insufficiency (CVI). A number of complications are associated with untreated venous reflux: including superficial thrombophlebitis as well as variceal rupture and haemorrhage. CVI often results in chronic skin changes referred to as stasis dermatitis. Stasis dermatitis is comprised of a spectrum of cutaneous abnormalities including edema, hyperpigmentation, eczema, lipodermatosclerosis and stasis ulceration. Ulceration represents the disease end point for severe CVI. CVI is associated with a reduced quality of life particularly in relation to pain, physical function and mobility. In severe cases, VV with ulcers, QOL has been rated to be as bad

Umbilical vein draining into the inferior vena cava via the internal iliac vein, bypassing the liver

International Nuclear Information System (INIS)

Currarino, G.; Stannard, M.W.; Texas Univ., Dallas, TX; Kolni, H.

1991-01-01

This is the third report of an anomalous umbilical vein draining ectopically in a left pelvic vein, probably the left internal iliac, and through the inferior vena cava into the right atrium. The anomaly was encountered in a newborn infant with nonimmune hydrops fetalis, hypertrophic cardiomyopathy, multiorgan failure and possibly Noonan Syndrome. (orig.)

Umbilical vein draining into the inferior vena cava via the internal iliac vein, bypassing the liver

Energy Technology Data Exchange (ETDEWEB)

Currarino, G.; Stannard, M.W. (Children' s Medical Center, Dallas, TX (United States). Dept. of Radiology Texas Univ., Dallas, TX (United States). Southwestern Medical Center); Kolni, H. (Methodist Hospital, Dallas, TX (United States). Dept. of Pediatrics)

1991-05-01

This is the third report of an anomalous umbilical vein draining ectopically in a left pelvic vein, probably the left internal iliac, and through the inferior vena cava into the right atrium. The anomaly was encountered in a newborn infant with nonimmune hydrops fetalis, hypertrophic cardiomyopathy, multiorgan failure and possibly Noonan Syndrome. (orig.).

Patterning of leaf vein networks by convergent auxin transport pathways.

Science.gov (United States)

Sawchuk, Megan G; Edgar, Alexander; Scarpella, Enrico

2013-01-01

The formation of leaf vein patterns has fascinated biologists for centuries. Transport of the plant signal auxin has long been implicated in vein patterning, but molecular details have remained unclear. Varied evidence suggests a central role for the plasma-membrane (PM)-localized PIN-FORMED1 (PIN1) intercellular auxin transporter of Arabidopsis thaliana in auxin-transport-dependent vein patterning. However, in contrast to the severe vein-pattern defects induced by auxin transport inhibitors, pin1 mutant leaves have only mild vein-pattern defects. These defects have been interpreted as evidence of redundancy between PIN1 and the other four PM-localized PIN proteins in vein patterning, redundancy that underlies many developmental processes. By contrast, we show here that vein patterning in the Arabidopsis leaf is controlled by two distinct and convergent auxin-transport pathways: intercellular auxin transport mediated by PM-localized PIN1 and intracellular auxin transport mediated by the evolutionarily older, endoplasmic-reticulum-localized PIN6, PIN8, and PIN5. PIN6 and PIN8 are expressed, as PIN1 and PIN5, at sites of vein formation. pin6 synthetically enhances pin1 vein-pattern defects, and pin8 quantitatively enhances pin1pin6 vein-pattern defects. Function of PIN6 is necessary, redundantly with that of PIN8, and sufficient to control auxin response levels, PIN1 expression, and vein network formation; and the vein pattern defects induced by ectopic PIN6 expression are mimicked by ectopic PIN8 expression. Finally, vein patterning functions of PIN6 and PIN8 are antagonized by PIN5 function. Our data define a new level of control of vein patterning, one with repercussions on other patterning processes in the plant, and suggest a mechanism to select cell files specialized for vascular function that predates evolution of PM-localized PIN proteins.

Patterning of leaf vein networks by convergent auxin transport pathways.

Directory of Open Access Journals (Sweden)

Megan G Sawchuk

Full Text Available The formation of leaf vein patterns has fascinated biologists for centuries. Transport of the plant signal auxin has long been implicated in vein patterning, but molecular details have remained unclear. Varied evidence suggests a central role for the plasma-membrane (PM-localized PIN-FORMED1 (PIN1 intercellular auxin transporter of Arabidopsis thaliana in auxin-transport-dependent vein patterning. However, in contrast to the severe vein-pattern defects induced by auxin transport inhibitors, pin1 mutant leaves have only mild vein-pattern defects. These defects have been interpreted as evidence of redundancy between PIN1 and the other four PM-localized PIN proteins in vein patterning, redundancy that underlies many developmental processes. By contrast, we show here that vein patterning in the Arabidopsis leaf is controlled by two distinct and convergent auxin-transport pathways: intercellular auxin transport mediated by PM-localized PIN1 and intracellular auxin transport mediated by the evolutionarily older, endoplasmic-reticulum-localized PIN6, PIN8, and PIN5. PIN6 and PIN8 are expressed, as PIN1 and PIN5, at sites of vein formation. pin6 synthetically enhances pin1 vein-pattern defects, and pin8 quantitatively enhances pin1pin6 vein-pattern defects. Function of PIN6 is necessary, redundantly with that of PIN8, and sufficient to control auxin response levels, PIN1 expression, and vein network formation; and the vein pattern defects induced by ectopic PIN6 expression are mimicked by ectopic PIN8 expression. Finally, vein patterning functions of PIN6 and PIN8 are antagonized by PIN5 function. Our data define a new level of control of vein patterning, one with repercussions on other patterning processes in the plant, and suggest a mechanism to select cell files specialized for vascular function that predates evolution of PM-localized PIN proteins.

Quantification of deep medullary veins at 7 T brain MRI

Energy Technology Data Exchange (ETDEWEB)

Kuijf, Hugo J.; Viergever, Max A.; Vincken, Koen L. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Bouvy, Willem H.; Razoux Schultz, Tom B.; Biessels, Geert Jan [University Medical Center Utrecht, Department of Neurology, Brain Center Rudolf Magnus, Utrecht (Netherlands); Zwanenburg, Jaco J.M. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands)

2016-10-15

Deep medullary veins support the venous drainage of the brain and may display abnormalities in the context of different cerebrovascular diseases. We present and evaluate a method to automatically detect and quantify deep medullary veins at 7 T. Five participants were scanned twice, to assess the robustness and reproducibility of manual and automated vein detection. Additionally, the method was evaluated on 24 participants to demonstrate its application. Deep medullary veins were assessed within an automatically created region-of-interest around the lateral ventricles, defined such that all veins must intersect it. A combination of vesselness, tubular tracking, and hysteresis thresholding located individual veins, which were quantified by counting and computing (3-D) density maps. Visual assessment was time-consuming (2 h/scan), with an intra-/inter-observer agreement on absolute vein count of ICC = 0.76 and 0.60, respectively. The automated vein detection showed excellent inter-scan reproducibility before (ICC = 0.79) and after (ICC = 0.88) visually censoring false positives. It had a positive predictive value of 71.6 %. Imaging at 7 T allows visualization and quantification of deep medullary veins. The presented method offers fast and reliable automated assessment of deep medullary veins. (orig.)

Preoperative mapping of the saphenous vein

DEFF Research Database (Denmark)

Levi-Mazloum, Niels Donald; Sillesen, H; Nielsen, Tina G

1996-01-01

A series of 124 patients had their greater saphenous vein assessed with duplex ultrasound scanning prior to planned infrainguinal bypass procedures. 33 (27%) bypass procedures thrombosed within the first year. A naturally occurring optimal vein diameter was discovered: 5.0-6.5 mm at mid-thigh lev...

Recanalization after acute deep vein thrombosis

Directory of Open Access Journals (Sweden)

Gustavo Mucoucah Sampaio Brandao

2013-12-01

Full Text Available The process of recanalization of the veins of the lower limbs after an episode of acute deep venous thrombosis is part of the natural evolution of the remodeling of the venous thrombus in patients on anticoagulation with heparin and vitamin K inhibitors. This remodeling involves the complex process of adhesion of thrombus to the wall of the vein, the inflammatory response of the vessel wall leading to organization and subsequent contraction of the thrombus, neovascularization and spontaneous lysis of areas within the thrombus. The occurrence of spontaneous arterial flow in recanalized thrombosed veins has been described as secondary to neovascularization and is characterized by the development of flow patterns characteristic of arteriovenous fistulae that can be identified by color duplex scanning. In this review, we discuss some controversial aspects of the natural history of deep vein thrombosis to provide a better understanding of its course and its impact on venous disease.

Renal vein doppler sonography in rabbits with acute ureteral obstruction: usefulness of impedance index of renal vein

International Nuclear Information System (INIS)

Sohn, Kyung Myung; Chung, Su Kyo; Lee, Sung Yong

2004-01-01

To evaluate the usefulness of the impedance index of the renal vein for the diagnosis of acute obstructive uropathy in rabbits. Ligation of the left ureter was done in 12 rabbits. Doppler sonography of the interlobar veins in both kidneys was checked before and 30 minutes, 1, 3, 6, 9 and 24 hours after ureteral ligation. The venous impedance index [(peak flow signal-least flow signal)/peak flow signal] was compared between the obstructed and non-obstructed kidneys for all periods. The change in the impedance index after ureteral ligation was also compared between the obstructed and non-obstructed kidneys. A decrease in the impedance index of the intrarenal vein was observed starting from 30 mins atter ureteral ligation, and the index remained low up to 24 hours after ureteral ligation. The obstructed kidneys had a significantly lower impedance index than the contralateral kidneys for all six of the postligation measurements (p< 0.05). There were significant differences in the change of impedance index after ureteral ligation between the obstructed and non-obstructed kidneys (p< 0.05). The impedance index of the intrarenal vein was significantly decreased in the obstructed kidneys. The measurement of the impedance index of the intrarenal vein using Doppler sonography could provide a useful method of diagnosing obstructive uropathy

Percutaneous transhepatic portal vein stenting in a patient with benign non-transplant postoperative portal vein stenosis: A case report

OpenAIRE

Madhusudhan, KS; Agrawal, Nikhil; Srivastava, Deep N; Pal, Sujoy; Gupta, Arun K

2013-01-01

Extrahepatic portal vein stenosis is caused by a variety of benign and malignant diseases and results in development of symptoms due to portal hypertension. Benign post-surgical adhesions causing portal vein stenosis in non-transplant population is an uncommon etiology of portal hypertension. Endovascular treatment of such patients with angioplasty and stenting is uncommonly reported in literature. We report a case of portal hypertension caused by benign postoperative portal vein fibrosis, su...

Animal Model of Acute Deep Vein Thrombosis

International Nuclear Information System (INIS)

Roy, Sumit; Laerum, Frode; Brosstad, Frank; Kvernebo, Knut; Sakariassen, Kjell S.

1998-01-01

Purpose: To develop an animal model of acute deep vein thrombosis (DVT). Methods: In part I of the study nine juvenile domestic pigs were used. Each external iliac vein was transluminally occluded with a balloon catheter. Thrombin was infused through a microcatheter in one leg according to one of the following protocols: (1) intraarterial (IA): 1250 U at 25 U/min in the common femoral artery (n= 3); (2) intravenous (IV): 5000 U in the popliteal vein at 500 U/min (n= 3), or at 100 U/min (n= 3). Saline was administered in the opposite leg. After the animals were killed, the mass of thrombus in the iliofemoral veins was measured. The pudendoepiploic (PEV), profunda femoris (PF), and popliteal veins (PV) were examined. Thrombosis in the tributaries of the superficial femoral vein (SFVt) was graded according to a three-point scale (0, +, ++). In part II of the study IV administration was further investigated in nine pigs using the following three regimens with 1000 U at 25 U/min serving as the control: (1) 1000 U at 100 U/min, (2) 250 U at 25 U/min, (3) 250 U at 6.25 U/min. Results: All animals survived. In part I median thrombus mass in the test limbs was 1.40 g as compared with 0.25 g in the controls (p= 0.01). PEV, PFV and PV were thrombosed in all limbs infused with thrombin. IV infusion was more effective in inducing thrombosis in both the parent veins (mass 1.32-1.78 g) and SVFt (++ in 4 of 6 legs), as compared with IA infusion (mass 0.0-1.16 g; SFVt ++ in 1 of 3 legs). In part II thrombus mass in axial veins ranged from 1.23 to 2.86 g, and showed no relationship with the dose of thrombin or the rate of infusion. Tributary thrombosis was less extensive with 250 U at 25 U/min than with the other regimens. Conclusion: Slow distal intravenous thrombin infusion in the hind legs of pigs combined with proximal venous occlusion induces thrombosis in the leg veins that closely resembles clinical DVT in distribution

A Case Study of Deep Vein Thrombosis of the Right Internal Jugular Vein in a Healthy 21-Year-Old Male

Directory of Open Access Journals (Sweden)

Javier Corral

2016-01-01

Full Text Available We are reporting a case of a healthy 21-year-old male, with no significant past medical history, who was found to have an incidental nonocclusive deep vein thrombosis in the right internal jugular vein detected on a head MRI previously ordered for work-up of headaches. A follow-up upper extremity venous Doppler ultrasound confirmed the presence of a partially occlusive deep vein thrombosis in the right jugular vein. The case presented is unique for the reason that the patient is young and has no prior risk factor, personal or familial, for venous thrombosis except for associated polycythemia on clinical presentation.

Veins improve fracture toughness of insect wings.

Directory of Open Access Journals (Sweden)

Jan-Henning Dirks

Full Text Available During the lifetime of a flying insect, its wings are subjected to mechanical forces and deformations for millions of cycles. Defects in the micrometre thin membranes or veins may reduce the insect's flight performance. How do insects prevent crack related material failure in their wings and what role does the characteristic vein pattern play? Fracture toughness is a parameter, which characterises a material's resistance to crack propagation. Our results show that, compared to other body parts, the hind wing membrane of the migratory locust S. gregaria itself is not exceptionally tough (1.04±0.25 MPa√m. However, the cross veins increase the wing's toughness by 50% by acting as barriers to crack propagation. Using fracture mechanics, we show that the morphological spacing of most wing veins matches the critical crack length of the material (1132 µm. This finding directly demonstrates how the biomechanical properties and the morphology of locust wings are functionally correlated in locusts, providing a mechanically 'optimal' solution with high toughness and low weight. The vein pattern found in insect wings thus might inspire the design of more durable and lightweight artificial 'venous' wings for micro-air-vehicles. Using the vein spacing as indicator, our approach might also provide a basis to estimate the wing properties of endangered or extinct insect species.

Transvenous liver biopsy via the femoral vein

International Nuclear Information System (INIS)

Khosa, F.; McNulty, J.G.; Hickey, N.; O'Brien, P.; Tobin, A.; Noonan, N.; Ryan, B.; Keeling, P.W.N.; Kelleher, D.P.; McDonald, G.S.A.

2003-01-01

AIM: To study the safety, effectiveness and diagnostic value of transvenous forceps biopsy of the liver in 54 patients with coagulopathy, gross ascites or morbid obesity and suspected liver disease in whom percutaneous liver biopsy was contraindicated. MATERIAL AND METHODS: Forceps biopsy of the liver via the femoral vein was attempted in 54 adult patients with advanced liver disease of unknown aetiology who had coagulation disorders (41 cases), gross ascites (11 cases) or morbid obesity (two cases). In each patient two to six biopsies (average four) were taken using a radial jaw forceps inserted via the right or left femoral vein. RESULTS: The procedure was successful in 53 cases. Hepatic vein catheterization failed in one patient. Adequate liver tissue for diagnosis was obtained in 84% of cases. One patient developed delayed haemorrhage at 12 h from a capsular leak that was undetected during the biopsy procedure. This patient required blood transfusions and laparotomy to control bleeding. There were no deaths in the 53 patients studied. Transient minor chest and shoulder pain was encountered during sheath insertion into a hepatic vein in 23 patients. Three patients developed a femoral vein haematoma, which resolved with conservative treatment. CONCLUSION: Transvenous liver biopsy via the femoral vein is another safe, effective, simple alternative technique of biopsy when the percutaneous route is contraindicated

Computed tomographic evaluation of the portal vein in the hepatomas

Energy Technology Data Exchange (ETDEWEB)

Lee, Kee Hyung; Lee, Seung Chul; Bae, Man Gil; Seo, Heung Suk; Kim, Soon Yong; Lee, Min Ho; Kee, Choon Suhk; Park, Kyung Nam [Hanyang University College of Medicine, Seoul (Korea, Republic of)

1986-10-15

Computed tomography and pornographic findings of 63 patients with hepatoma, undergone hepatic angiography and superior mesenteric pornography for evaluation of tumor and thrombosis of portal vein and determination of indication of transcatheter arterial embolization for palliative treatment of hepatoma from April, 85 to June, 86 in Hanyang university hospital, were reviewed. The results were as follows: 1. In 36 cases, portal vein thrombosis was detected during photography. Nineteen of 37 cases which revealed localized hepatoma in the right lobe of the liver showed portal vein thrombosis; 9 of 11 cases of the left lobe; 8 of 14 cases which were involved in entire liver revealed thrombosis. One case localized in the caudate lobe showed no evidence of invasion to portal vein. 2. Twenty-four of 34 cases with diffuse infiltrative hepatoma revealed portal vein thrombosis and the incidence of portal vein thrombosis in this type were higher than in the cases of the nodular type. 3. The portal vein thrombosis appeared as filling defects of low density in the lumen of the portal veins in CT and they did not reveal contrast enhancement. 4. CT revealed well the evidence of obstructions in the cases of portal vein thrombosis and the findings were well-corresponded to the findings of the superior mesenteric photography. 5. Five of the cases of the portal vein thrombosis were missed in the CT and the causes were considered as due to partial volume effect of enhanced portal vein with partial occlusion or arterioportal shunts. 6. Six of 13 cases with occlusion of main portal vein showed cavernous transformation and they were noted as multiple small enhanced vascularities around the porta hepatis in the CT. According to the results, we conclude that CT is a useful modality to detect the changes of the portal veins in the patients of the hepatoma.

Computed tomographic evaluation of the portal vein in the hepatomas

International Nuclear Information System (INIS)

Lee, Kee Hyung; Lee, Seung Chul; Bae, Man Gil; Seo, Heung Suk; Kim, Soon Yong; Lee, Min Ho; Kee, Choon Suhk; Park, Kyung Nam

1986-01-01

Computed tomography and pornographic findings of 63 patients with hepatoma, undergone hepatic angiography and superior mesenteric pornography for evaluation of tumor and thrombosis of portal vein and determination of indication of transcatheter arterial embolization for palliative treatment of hepatoma from April, 85 to June, 86 in Hanyang university hospital, were reviewed. The results were as follows: 1. In 36 cases, portal vein thrombosis was detected during photography. Nineteen of 37 cases which revealed localized hepatoma in the right lobe of the liver showed portal vein thrombosis; 9 of 11 cases of the left lobe; 8 of 14 cases which were involved in entire liver revealed thrombosis. One case localized in the caudate lobe showed no evidence of invasion to portal vein. 2. Twenty-four of 34 cases with diffuse infiltrative hepatoma revealed portal vein thrombosis and the incidence of portal vein thrombosis in this type were higher than in the cases of the nodular type. 3. The portal vein thrombosis appeared as filling defects of low density in the lumen of the portal veins in CT and they did not reveal contrast enhancement. 4. CT revealed well the evidence of obstructions in the cases of portal vein thrombosis and the findings were well-corresponded to the findings of the superior mesenteric photography. 5. Five of the cases of the portal vein thrombosis were missed in the CT and the causes were considered as due to partial volume effect of enhanced portal vein with partial occlusion or arterioportal shunts. 6. Six of 13 cases with occlusion of main portal vein showed cavernous transformation and they were noted as multiple small enhanced vascularities around the porta hepatis in the CT. According to the results, we conclude that CT is a useful modality to detect the changes of the portal veins in the patients of the hepatoma.

Image Quality Enhancement Using the Direction and Thickness of Vein Lines for Finger-Vein Recognition

OpenAIRE

Park, Young Ho; Park, Kang Ryoung

2012-01-01

On the basis of the increased emphasis placed on the protection of privacy, biometric recognition systems using physical or behavioural characteristics such as fingerprints, facial characteristics, iris and finger‐vein patterns or the voice have been introduced in applications including door access control, personal certification, Internet banking and ATM machines. Among these, finger‐vein recognition is advantageous in that it involves the use of inexpensive and small devices that are diffic...

Usability of #betta#-spectrometric method to prospecting for copper-porphyric skarn and gold-quartz-sulfide deposits

International Nuclear Information System (INIS)

Syromyatnikov, N.G.; Ivanova, Eh.I.; Karpukhin, V.G.; Trofimova, L.A.; Tolmachev, I.I.

1982-01-01

Possibility of the prospecting for non-radioactive element deposits by means of radioactive elements as indicators is studied. Radioactive elements (uranium, thorium and potassium) were determined by gamma spectroscopy. Radiometric methods of prospecting are effective and economical. Clark contents of radioelements in rocks were determined in situ by field gamma spectrometers. It is established that copper-porphyric deposits are regularly controlled from the surface by aureoles of increased uranium contents, which sizes reach 400x500 m and can be revealed by gamma spectroscopy during 1:25000 and more large-scale survey. Skarn-ore zones of deposits of different mineral types (copper, polymetallic, iron ore ones) are fixed on the surface by increased radioactivity; this fact can be used as search criterion. Gold-bearing quartz veins differ from barren lodes by a higher level of total radioactivity and high potassium content. Top walls of ore-bearing quartz veins are mainly enriched by radioelements

Magmatic-vapor expansion and the formation of high-sulfidation gold deposits: Chemical controls on alteration and mineralization

Science.gov (United States)

Henley, R.W.; Berger, B.R.

2011-01-01

Large bulk-tonnage high-sulfidation gold deposits, such as Yanacocha, Peru, are the surface expression of structurally-controlled lode gold deposits, such as El Indio, Chile. Both formed in active andesite-dacite volcanic terranes. Fluid inclusion, stable isotope and geologic data show that lode deposits formed within 1500. m of the paleo-surface as a consequence of the expansion of low-salinity, low-density magmatic vapor with very limited, if any, groundwater mixing. They are characterized by an initial 'Sulfate' Stage of advanced argillic wallrock alteration ?? alunite commonly with intense silicification followed by a 'Sulfide' Stage - a succession of discrete sulfide-sulfosalt veins that may be ore grade in gold and silver. Fluid inclusions in quartz formed during wallrock alteration have homogenization temperatures between 100 and over 500 ??C and preserve a record of a vapor-rich environment. Recent data for El Indio and similar deposits show that at the commencement of the Sulfide Stage, 'condensation' of Cu-As-S sulfosalt melts with trace concentrations of Sb, Te, Bi, Ag and Au occurred at > 600 ??C following pyrite deposition. Euhedral quartz crystals were simultaneously deposited from the vapor phase during crystallization of the vapor-saturated melt occurs to Fe-tennantite with progressive non-equilibrium fractionation of heavy metals between melt-vapor and solid. Vugs containing a range of sulfides, sulfosalts and gold record the changing composition of the vapor. Published fluid inclusion and mineralogical data are reviewed in the context of geological relationships to establish boundary conditions through which to trace the expansion of magmatic vapor from source to surface and consequent alteration and mineralization. Initially heat loss from the vapor is high resulting in the formation of acid condensate permeating through the wallrock. This Sulfate Stage alteration effectively isolates the expansion of magmatic vapor in subsurface fracture arrays

A Modified Technique of Basilic Vein Transposition for Haemodialysis

International Nuclear Information System (INIS)

Chaudhary, F. A.; Parvez, Z.

2014-01-01

Objective: To modify the technique of basilic vein transposition for vascular accesss for haemodialysis aiming at better maturation rate, longer survival of fistula and lesser complications. Study Design: Case series. Place and Duration of Study: Shaikh Zayed Hospital and Omer Hospital, Lahore, from February 2008 to July 2011. Methodology: Patients referred for basilic vein transposition for haemodialysis vascular access were prospectively enrolled. The surgical technique included small tracking incisions, an extra 3 - 4 cm of vein length harvesting to avoid tension in the vein in its new course, an oval arteriotomy and a smooth curved pathway, away from vein harvesting incision to avoid entrapment of vein in the scar. Maturation rate, fistula survival and other complications were noted. Results: There was no immediate failure in 51 patients. The complications during follow-up period were infection and thrombosis, bleeding and non-development of basilic vein in 2 patients each; and false aneurysm formation in one. Four patients died during follow-up period. The maturation time was 4.9 A +- 1.1 weeks. The early patency rate was 92.2%, same at 6 months and 90.7% at 12 months. Conclusion: Arteriovenous fistula constructed with modified technique of basilic vein transposition is an acceptable and valid option of vascular access for haemodialysis. (author)

Fluid Inclusion Study of The Tumpangpitu High Sulfidation Epithermal Gold Deposit in Banyuwangi District, East Java, Indonesia

Directory of Open Access Journals (Sweden)

Yu Yu Myaing

2018-03-01

Full Text Available The Tumpangpitu high sulfidation (HS epithermal gold deposit is located in the south coast of East Java, Banyuwangi District, East Java Province, Indonesia. This area lies within the central portion of the Cenozoic Sunda‐Banda magmatic arc which trends southeast from northern Sumatra to west Java then eastward through east Java, Bali, Lombok, Sumbawa and terminating at Banda sea. The geology of the Tumpangpitu is predominantly occupied by Late Oligocene to Middle Miocene low-K calc-alkaline to alkaline andesitic volcanic rocks and interbedded with volcaniclastic rock sequences, which are associated with low-K intermediate intrusions. The mineralization style at the Tumpangpitu area is composed of a high‐sulfidation (HS epithermal gold-copper system which is typically associated with concealed gold-rich porphyry copper system. The HS epithermal mineralization is hosted by volcanic and volcaniclastic rocks in this research area. The mineralization domains are divided into Zone A, Zone B and Zone C which are situated along NW-SE-trending silica ledges zones. The HS epithermal mineralization is texturally occurs as vuggy replacements mineralization as well as stockworks, disseminated forms, fractures and veins. Fluid inclusion study was conducted for 6 quartz vein samples which petrographically entrapped fluid inclusions. Homogenization temperature (Th and melting temperature (Tm can microthermometrically be determined by fluid inclusion analysis. The average homogenization temperature (Th of the fluid inclusions gives 180˚C to 342˚C and melting temperature are from -0.1 ˚C to -1.4˚C. Tm corresponds to the salinities ranging from 0.1 to 4.5 wt% NaCl equivalent. The paleodepth of ore formation can be estimated from the salinity of fluid. Since the deposit was not formed at boiling condition, the minimum paleodepth of ore (quartz samples taken from both shallow level (53.35 m and deep level (135.15 m is determined at 650m and 1,220 m

Percutaneous transhepatic portal vein stenting in a patient with benign non-transplant postoperative portal vein stenosis: A case report

Directory of Open Access Journals (Sweden)

KS Madhusudhan

2013-01-01

Full Text Available Extrahepatic portal vein stenosis is caused by a variety of benign and malignant diseases and results in development of symptoms due to portal hypertension. Benign post-surgical adhesions causing portal vein stenosis in non-transplant population is an uncommon etiology of portal hypertension. Endovascular treatment of such patients with angioplasty and stenting is uncommonly reported in literature. We report a case of portal hypertension caused by benign postoperative portal vein fibrosis, successfully treated by self-expandable metallic stent.

Gold monetization and gold discipline

OpenAIRE

Robert P. Flood; Peter M. Garber

1981-01-01

The paper is a study of the price level and relative price effects of a policy to monetize gold and fix its price at a given future time and at the then prevailing nominal price. Price movements are analyzed both during the transition to the gold standard and during the post-monetization period. The paper also explores the adjustments to fiat money which are necessary to ensure that this type of gold monetization is non-inflationary. Finally, some conditions which produce a run on the governm...

Mineralogy and fluid inclusion studies in kalchoye Copper- gold deposit, East of Esfahan

Directory of Open Access Journals (Sweden)

Rezvan Mehvary

2009-09-01

Full Text Available Kalchoye Copper-gold deposit is located about 110 kilometers east of Esfahan province and within the Eocene volcano sedimentary rocks. Sandy tuff and andesite lava are important members of this complex.The form of mineralization in area is vein and veinlet and quartz as the main gangue phase. The main ore minerals are chalcopyrite, chalcocite, galena and weathered minerals such as goethite, iron oxides, malachite and azurite. Studies in area indicate that ore mineralization Kalchoye is low sulfide, quartz type of hydrothermal ore deposits and results of thermometry studies on quartz minerals low- medium fluid with low potential mineralization is responsible for mineralization in this area.

Applied anatomic study of testicular veins in adult cadavers and in human fetuses

Directory of Open Access Journals (Sweden)

Luciano A. Favorito

2007-04-01

Full Text Available OBJECTIVES: Analyze the anatomic variations of the testicular veins in human cadavers and fetuses. MATERIALS AND METHODS: One hundred male adult cadavers and 24 fetuses were studied. Four anatomic aspects were considered: 1 Number of testicular veins, 2 The local of vein termination, 3 Type and number of collaterals present and 4 Testicular vein termination angle. RESULTS: Cadavers - Right side - One testicular vein occurred in 85% and 2 veins in 5% of the cases. There were communicating veins with the colon in 21% of the cases. Left side - One testicular vein occurred in 82%, two veins in 15%, three veins in 2% and four veins in 1% of the cases. There were communicating veins with the colon in 31% of the cases. Fetuses - Right side -One testicular vein occurred in all cases. This vein drained to the vena cava in 83.3% of the cases, to the junction of the vena cava with the renal vein in 12.5% and to the renal vein in 4.2%. There were communicating veins with the colon in 25% of the cases. Left side - One testicular vein occurred in 66.6% of the cases, and 2 veins in occurred 33.3%. Communicating veins with the colon were found in 41.6% of the cases. CONCLUSION: The testicular vein presents numeric variations and also variations in its local of termination. In approximately 30% of the cases, there are collaterals that communicate the testicular vein with retroperitoneal veins. These anatomic findings can help understanding the origin of varicocele and its recurrence after surgical interventions.

Supracardiac total anomalous pulmonary venous connection with a descending vertical vein.

Science.gov (United States)

Shah, Sejal; Singh, Mukesh; John, Colin; Maheshwari, Sunita

2009-10-01

The commonly used Darling classification for total anomalous pulmonary venous connection (TAPVC) consists of supracardiac, cardiac, infracardiac, and mixed types (Craig et al., Lab Invest 6:44-64, 1967). In supracardiac TAPVC, the common pulmonary vein drains superiorly into the left innominate vein, the superior vena cava, or the azygos vein by way of an ascending vertical vein. We describe a case of supracardiac TAPVC draining into the azygos vein atypically by way of a descending vertical vein.

Induced chorioretinal venous anastomosis in experimental retinal branch vein occlusion.

OpenAIRE

McAllister, I L; Yu, D Y; Vijayasekaran, S; Barry, C; Constable, I

1992-01-01

Iatrogenic retinal vein to choroidal vein anastomoses were created using laser photocoagulation in six of seven dog eyes in which a partial branch retinal vein occlusion had previously been created photochemically. A similar attempt to create an anastomosis was made in six control eyes in which no branch vein occlusion was present. In the eyes in which a branch retinal vein had been created, a venous chorioretinal anastomosis appeared to be present by 3 to 6 weeks. In three control eyes simil...

Radiation Retinopathy Associated with Central Retinal Vein Occlusion

Institute of Scientific and Technical Information of China (English)

Yan; Liu; FengWen

2007-01-01

Purpose: To report a case of radiation retinopathy associated with central retinal vein occlusion.Methods: The clinical features and fundus fluorescein angiography of this case were analyzed.Results: The patient had been treated with radiotherapy for her nasopharyngeal carcinoma, and presented with sudden visual loss in the left eye. The funduscopic examination and fluorescein angiography showed the features of radiation retinopathy in both eyes, and central retinal vein occlusion in the left eye.Conclusions: Radiation retinopathy can be associated with central retinal vein occlusion in the same eye, and it seems that the endothelial cell loss caused by radiation retinopathy may lead to retinal vein occlusion.

Surface-modified gold nanorods for specific cell targeting

Science.gov (United States)

Wang, Chan-Ung; Arai, Yoshie; Kim, Insun; Jang, Wonhee; Lee, Seonghyun; Hafner, Jason H.; Jeoung, Eunhee; Jung, Deokho; Kwon, Youngeun

2012-05-01

Gold nanoparticles (GNPs) have unique properties that make them highly attractive materials for developing functional reagents for various biomedical applications including photothermal therapy, targeted drug delivery, and molecular imaging. For in vivo applications, GNPs need to be prepared with very little or negligible cytotoxicitiy. Most GNPs are, however, prepared using growth-directing surfactants such as cetyl trimethylammonium bromide (CTAB), which are known to have considerable cytotoxicity. In this paper, we describe an approach to remove CTAB to a non-toxic concentration. We optimized the conditions for surface modification with methoxypolyethylene glycol thiol (mPEG), which replaced CTAB and formed a protective layer on the surface of gold nanorods (GNRs). The cytotoxicities of pristine and surface-modified GNRs were measured in primary human umbilical vein endothelial cells and human cell lines derived from hepatic carcinoma cells, embryonic kidney cells, and thyroid papillary carcinoma cells. Cytotoxicity assays revealed that treating cells with GNRs did not significantly affect cell viability except for thyroid papillary carcinoma cells. Thyroid cancer cells were more susceptible to residual CTAB, so CTAB had to be further removed by dialysis in order to use GNRs for thyroid cell targeting. PEGylated GNRs are further modified to present monoclonal antibodies that recognize a specific surface marker, Na-I symporter, for thyroid cells. Antibody-conjugated GNRs specifically targeted human thyroid cells in vitro.

Disastrous Portal Vein Embolization Turned into a Successful Intervention

Energy Technology Data Exchange (ETDEWEB)

Dobrocky, Tomas, E-mail: tomas.dobrocky@insel.ch [University of Bern, Department of Interventional, Pediatric and Diagnostic Radiology, Inselspital, University Hospital (Switzerland); Kettenbach, Joachim, E-mail: joachim.kettenbach@stpoelten.lknoe.at [Universitätsklinikum St. Pölten-Lilienfeld, Institute of Medical Radiology, Diagnostic, Intervention (Austria); Lopez-Benitez, Ruben, E-mail: Ruben.lopez@insel.ch; Kara, Levent, E-mail: levent.kara@insel.ch [University of Bern, Department of Interventional, Pediatric and Diagnostic Radiology, Inselspital, University Hospital (Switzerland)

2015-10-15

Portal vein embolization (PVE) may be performed before hemihepatectomy to increase the volume of future liver remnant (FLR) and to reduce the risk of postoperative liver insufficiency. We report the case of a 71-year-old patient with hilar cholangiocarcinoma undergoing PVE with access from the right portal vein using a mixture of n-butyl-2-cyanoacrylate and ethiodized oil. During the procedure, nontarget embolization of the left portal vein occurred. An aspiration maneuver of the polymerized plug failed; however, the embolus obstructing portal venous flow in the FLR was successfully relocated into the right portal vein while carefully bypassing the plug with a balloon catheter, inflating the balloon, and pulling the plug into the main right portal vein.

Sulphur isotopes in a metamorphogenic gold deposit, Macraes mine, Otago Schist, New Zealand

International Nuclear Information System (INIS)

Craw, D.; Hall, A.J.; Fallick, A.E.; Boyce, A.J.

1995-01-01

The Macraes gold quartz vein deposit, New Zealand, is located in a shear zone cutting greenschist facies metasediments of the Otago Schist. The deposit has been interpreted as being metamorphogenic in origin as there is no evidence for coeval magmatic activity in the Otago Schist orogen. The immediate host rock at the Macraes deposit is pyritic (δ 34 S = -2.7 to -1.3 per mil ) and locally weakly graphitic schist, a rare rock type in the Otago Schist. Sulphur isotope analyses of pyrite and arsenopyrite extracts from auriferous veins and wall-rock schist provide a similar narrow range in δ 34 S values, from -3.0 to -1.0 per mil (n=9). The lack of isotopically depleted sulphur, the narrow range in values, and the replacement sulphide textures help discount a primary bacteriogenic origin for host-rock sulphide. Sulphide in both veins and wall rock is of hydrothermal origin. Sulphides in metasediments and metavolcanics elsewhere in the Otago Schist have δ 34 S in the narrow range -6 to +6 per mil. The sulphur isotope data are consistent with origin of hydrothermal sulphur within the metamorphic pile but provide no constraint on specific rock types which contributed the sulphur to the hydrothermal fluid. The study demonstrates that sulphur isotopic signatures near zero per mil can arise without any direct magmatic input into the mineralisation process. (author). 34 refs., 2 figs., 1 tab

Targeting of Gold Deposits in Amazonian Exploration Frontiers using Knowledge- and Data-Driven Spatial Modeling of Geophysical, Geochemical, and Geological Data

Science.gov (United States)

Magalhães, Lucíola Alves; Souza Filho, Carlos Roberto

2012-03-01

This paper reports the application of weights-of-evidence, artificial neural networks, and fuzzy logic spatial modeling techniques to generate prospectivity maps for gold mineralization in the neighborhood of the Amapari Au mine, Brazil. The study area comprises one of the last Brazilian mineral exploration frontiers. The Amapari mine is located in the Maroni-Itaicaiúnas Province, which regionally hosts important gold, iron, manganese, chromite, diamond, bauxite, kaolinite, and cassiterite deposits. The Amapari Au mine is characterized as of the orogenic gold deposit type. The highest gold grades are associated with highly deformed rocks and are concentrated in sulfide-rich veins mainly composed of pyrrhotite. The data used for the generation of gold prospectivity models include aerogeophysical and geological maps as well as the gold content of stream sediment samples. The prospectivity maps provided by these three methods showed that the Amapari mine stands out as an area of high potential for gold mineralization. The prospectivity maps also highlight new targets for gold exploration. These new targets were validated by means of detailed maps of gold geochemical anomalies in soil and by fieldwork. The identified target areas exhibit good spatial coincidence with the main soil geochemical anomalies and prospects, thus demonstrating that the delineation of exploration targets by analysis and integration of indirect datasets in a geographic information system (GIS) is consistent with direct prospecting. Considering that work of this nature has never been developed in the Amazonian region, this is an important example of the applicability and functionality of geophysical data and prospectivity analysis in regions where geologic and metallogenetic information is scarce.

Non-contact finger vein acquisition system using NIR laser

Science.gov (United States)

Kim, Jiman; Kong, Hyoun-Joong; Park, Sangyun; Noh, SeungWoo; Lee, Seung-Rae; Kim, Taejeong; Kim, Hee Chan

2009-02-01

Authentication using finger vein pattern has substantial advantage than other biometrics. Because human vein patterns are hidden inside the skin and tissue, it is hard to forge vein structure. But conventional system using NIR LED array has two drawbacks. First, direct contact with LED array raise sanitary problem. Second, because of discreteness of LEDs, non-uniform illumination exists. We propose non-contact finger vein acquisition system using NIR laser and Laser line generator lens. Laser line generator lens makes evenly distributed line laser from focused laser light. Line laser is aimed on the finger longitudinally. NIR camera was used for image acquisition. 200 index finger vein images from 20 candidates are collected. Same finger vein pattern extraction algorithm was used to evaluate two sets of images. Acquired images from proposed non-contact system do not show any non-uniform illumination in contrary with conventional system. Also results of matching are comparable to conventional system. We developed Non-contact finger vein acquisition system. It can prevent potential cross contamination of skin diseases. Also the system can produce uniformly illuminated images unlike conventional system. With the benefit of non-contact, proposed system shows almost equivalent performance compared with conventional system.

Management of reticular veins and telangiectases.

Science.gov (United States)

Smith, Philip Coleridge

2015-11-01

To review the literature related to the management of reticular varices and telangiectases of the lower limbs to provide guidance on the treatment of these veins. Very few randomised clinical trials are available in this field. A European Guideline has been published on the treatment of reticular varices and telangiectases, which is largely based on the opinion of experts. Older accounts written by individual phlebologists contain extensive advice from their own practice, which is valuable in identifying effective methods of sclerotherapy. All accounts indicate that a history should be taken combined with a clinical and ultrasound examination to establish the full extent of the venous disease. Sclerotherapy is commenced by injecting the larger veins first of all, usually the reticular varices. Later in the same session or in subsequent sessions, telangiectases can be treated by direct injection. Following treatment, the application of class 2 compression stockings for a period of up to three weeks is beneficial but not used universally by all phlebologists. Further sessions can follow at intervals of 2-8 weeks in which small residual veins are treated. Resistant veins can be managed by ultrasound-guided injection of underlying perforating veins and varices. Other treatments including RF diathermy and laser ablation of telangiectases have very limited efficacy in this condition. Sclerotherapy, when used with the correct technique, is the most effective method for the management of reticular varices and telangiectases. © The Author(s) 2015.

Kinetics of vein graft hyperplasia

International Nuclear Information System (INIS)

Zwolak, R.M.; Adams, M.C.; Clowes, A.W.

1986-01-01

Human aortocoronary vein grafts fail due to accelerated occlusive disease. The possibility that this is related to cellular hyperplasia was investigated in a rabbit model where kinetics of vein graft thickening, endothelial (EC) repair, and smooth muscle cell (SMC) proliferation were measured from 2 days to 24 weeks after implanting jugular vein segments in the carotid artery. Immediately after graft placement focal EC denudation was observed. These defects were repaired within 1 week and did not recur. By 4 weeks intimal area had increased 30 fold from 0.028 +/- 0.004 to 0.705 +/- 0.021 mm 2 , and a 24 weeks was 0.93 +/- 0.21 mm 2 . This response did not produce a reduction in graft lumen area. EC and SMC thymidine-labeling index were measured by en face and cross-section autoradiography after injection of 3 H-thymidine and perfusion fixation. Despite rapid EC surface repair EC labeling index remained elevated and only returned to normal levels at 12 weeks; SMC labeling was 10 fold greater than baseline even at 24 weeks (0.22% vs 0.02%). SMC mass demonstrated morphometrically increased between 2 and 12 weeks. Intimal thickening in vein grafts is due to SMC proliferation and develops after the EC layer has been restored. In contrast, intimal SMC proliferate in damaged arteries when the EC layer is absent and cease when the EC layer is regenerated

Interventional treatment for the occlusive hepatic veins in Budd-Chiari syndrome

International Nuclear Information System (INIS)

Zhang Xitong; Xu Ke; Feng Bo; Su Hongying; Li Hong; Zu Maoheng; Cui Jingguo; Yang Xueliang; Zhao Jinxu; Chen Kai

2003-01-01

Objective: To evaluate the interventional methods for occlusive hepatic veins in Budd-Chiari syndrome and its mid and long-term effects. Methods: Forty-two patients (male 17 cases and female 25 cases) aged from 18 to 57 years old (mean 34.5 years) were studied. The liver functions were Child A in 23 cases, Child B in 6 cases, and Child C in 13 cases, respectively. A total of 92 hepatic veins were occluded. Among them, 29 left hepatic veins, 24 middle hepatic veins, 36 right hepatic veins, and 3 accessory hepatic veins were occluded. Thirty-four patients were accompanied with the stenotic or occlusive inferior vena cave (IVC) . The interventional methods included: (1) recanalization of occlusive hepatic veins (by transjugular, transfemoral, and percutaneous transhepatic route, or the combination of above three methods); (2) percutaneous transluminal angioplasty; (3) self-expanding stent implantation. The occlusive IVC in 32 patients also accepted PTA and/or stent implantation. Results: The successful recanalization was carried out in forty hepatic veins in 40 patients. PTA of occlusive veins was followed by stent implantation in 8 patients. The pressure of hepatic veins dropped from 34.5 cm H 2 O (25.0-48.0 cm H 2 O) to 22.0 cm H 2 O (12.0-35.0 cm H 2 O) after intervention (T=11.50, P < 0.01). The symptoms and pathological signs improved obviously in 32 cases and improved partly in 8 cases. During the follow-up period from 1 month to 54 months (mean 27.5 months), one cases died of liver function failure at one month after intervention. The re-intervention of occlusive veins in two cases were performed and the better results were acquired again. Five cases didn't accept re-intervention. Neither recurrence of symptoms nor re-occlusion of hepatic veins was found in the other 32 patients. Conclusion: (1) Multiple and synthetical interventional methods for the occlusive hepatic veins in Budd-Chiari syndrome can be utilized. (2) The intervention of hepatic vein is mini

Duplex sonography of the near-surface leg veins; Duplexsonographie der oberflaechlichen Beinvenen

Energy Technology Data Exchange (ETDEWEB)

Mendoza, E.

2007-07-01

The book contains the following contributions: The ultrasonograph, selection of the ultrasonic transducer, anatomy of the near-surface vein system, physiology of the near-surface vein system, varicose status classification, systematics of the duplex sonography of near-surface leg veins, provocational maneuver for the duplex sonographic varicose diagnostics, exploration of vena saphena parva, perforans veins, side branches, phlebitis, sonography for varicose therapy, postsurgical sonography, deep leg veins, examination of near-surface leg veins for the pathology of the deep vein system, differential diagnostic clarification of leg oedema from the phlebologic-lymphological view, diagnostic side features along the near-surface leg veins.

Generating and analyzing synthetic finger vein images

NARCIS (Netherlands)

Hillerström, Fieke; Kumar, Ajay; Veldhuis, Raymond N.J.

2014-01-01

Abstract: The finger-vein biometric offers higher degree of security, personal privacy and strong anti-spoofing capabilities than most other biometric modalities employed today. Emerging privacy concerns with the database acquisition and lack of availability of large scale finger-vein database have

Coal-gold agglomeration: an alternative separation process in gold recovery

Energy Technology Data Exchange (ETDEWEB)

Akcil, A.; Wu, X.Q.; Aksay, E.K. [Suleyman Demirel University, Isparta (Turkey). Dept. of Mining Engineering

2009-07-01

Considering the increasing environmental concerns and the potential for small gold deposits to be exploited in the future, the uses of environmentally friendly processes are essential. Recent developments point to the potential for greatly increased plant performance through a separation process that combines the cyanide and flotation processes. In addition, this kind of alternative treatment processes to the traditional gold recovery processes may reduce the environmental risks of present small-scale gold mining. Gold recovery processes that applied to different types of gold bearing ore deposits show that the type of deposits plays an important role for the selection of mineral processing technologies in the production of gold and other precious metals. In the last 25 years, different alternative processes have been investigated on gold deposits located in areas where environmental issues are a great concern. In 1988, gold particles were first recovered by successful pilot trial of coal-gold agglomeration (CGA) process in Australia. The current paper reviews the importance of CGA in the production of gold ore and identifies areas for further development work.

Phage based green chemistry for gold ion reduction and gold retrieval.

Science.gov (United States)

Setyawati, Magdiel I; Xie, Jianping; Leong, David T

2014-01-22

The gold mining industry has taken its toll on the environment, triggering the development of more environmentally benign processes to alleviate the waste load release. Here, we demonstrate the use of bacteriophages (phages) for biosorption and bioreduction of gold ions from aqueous solution, which potentially can be applied to remediate gold ions from gold mining waste effluent. Phage has shown a remarkably efficient sorption of gold ions with a maximum gold adsorption capacity of 571 mg gold/g dry weight phage. The product of this phage mediated process is gold nanocrystals with the size of 30-630 nm. Biosorption and bioreduction processes are mediated by the ionic and covalent interaction between gold ions and the reducing groups on the phage protein coat. The strategy offers a simple, ecofriendly and feasible option to recover of gold ions to form readily recoverable products of gold nanoparticles within 24 h.

Complications of umbilical vein catherisation. Case Report

International Nuclear Information System (INIS)

Bothur-Nowacka, J.; Czech-Kowalska, J.; Gruszfeld, D.; Nowakowska-Rysz, M.; Dobrzanska, A.; Kosciesza, A.; Polnik, D.

2011-01-01

Umbilical vein catheterization is a relatively easy procedure performed routinely on the neonate intensive care units. It provides a fast central vein access, but some complications have been described in the literature. Case Reports: We presented a case report of a premature infant (34 hbd) with extravasation of the parenteral nutrition and drugs to the liver after umbilical vein catheterization. Fever and increasing biochemical markers of infection were observed. USG revealed a heterogenic, well-limited space of 4 cm in diameter, located in the right lobe of the liver. CT excluded liver abscess. Considering neoplastic process or incorrect location of the catheter of the central vein, we performed liver biopsy. Results: Cytological and biochemical analysis of the aspirated fluid revealed extravasation of parenteral nutrition to the liver.Our case confirms the necessity of controlling a proper location of the central catheter right after its insertion and during hospitalization. (authors)

[Treatment of nontumoral portal vein thrombosis in cirrhosis].

Science.gov (United States)

Bañares, Rafael; Catalina, María-Vega

2014-07-01

Portal vein thrombosis in cirrhosis is a relatively common complication associated with the presence of an accompanying prothrombotic phenotype of advanced cirrhosis. The consequences of portal vein thrombosis are relevant because it can be associated with impaired hepatic function, might contraindicate hepatic transplantation and could increase morbidity in the surgical procedure. There is controversy concerning the most effective treatment of portal vein thrombosis, which is based on information that is seldom robust and whose primary objective is to achieve a return to vessel patency. Various studies have suggested that starting anticoagulation therapy early is associated with portal vein repatency more frequently than without treatment and has a low rate of complications. There are no proven data on the type of anticoagulant (low-molecular-weight heparins or dicoumarin agents) and the treatment duration. The implementation of TIPS is technically feasible in thrombosis without cavernous transformation and is associated with portal vein recanalization in a significant proportion of cases. Thrombolytic therapy does not appear to present an adequate balance between efficacy and safety; its use is therefore not supported for this indication. The proper definition of treatment for portal vein thrombosis requires properly designed studies to delimit the efficacy and safety of the various alternatives. Copyright © 2014 Elsevier España, S.L. All rights reserved.

31 CFR 100.4 - Gold coin and gold certificates in general.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Gold coin and gold certificates in... EXCHANGE OF PAPER CURRENCY AND COIN In General § 100.4 Gold coin and gold certificates in general. Gold coins, and gold certificates of the type issued before January 30, 1934, are exchangeable, as provided...

VENOUS SAMPLING FOR CUSHING DISEASE: COMPARISON OF INTERNAL JUGULAR VEIN AND INFERIOR PETROSAL SINUS SAMPLING.

Science.gov (United States)

Radvany, Martin G; Quinones-Hinojosa, Alfredo; Gallia, Gary L; Wand, Gary S; Salvatori, Roberto

2016-09-01

Because magnetic resonance imaging (MRI) fails to detect many adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas, inferior petrosal sinus sampling (IPSS) is considered the gold standard to differentiate Cushing disease (CD) from ectopic ACTH secretion syndrome (EAS). Some authors have suggested internal jugular vein sampling (IJVS) as an alternative to IPSS. We simultaneously compared IJVS to IPSS in 30 consecutive patients referred for ACTH-dependent Cushing syndrome and equivocal MRI exams. Five sites were simultaneously sampled in each patient (right and left IPS, right and left IJV, and femoral vein) before and after the administration of corticotrophin-releasing hormone or desmopressin. The test was considered consistent with CD when the IPS to peripheral ratio was >2 at baseline or >3 after stimulus and the IJV to peripheral ratio was >1.7 at baseline or >2 after stimulus. In 27 of 30 patients, IPSS results were consistent with a central source of ACTH. Two of the other 3 patients had EAS (one lung carcinoid and one occult), and 1 patient had pathology-proven CD. The sensitivity of IPSS was 96.4%. Only 64.2% of these patients had results meeting criteria for a central source of ACTH by IJVS criteria. Twenty patients with centralizing IPPS have undergone pituitary surgery. Of these, the central origin of excessive ACTH was confirmed with certainty in 16 patients. Among these 16 patients, the IPSS sensitivity was 93.8%, whereas 5 patients had false-negative IJVS (68.7% sensitivity). These results do not support the routine use of IJVS in establishing if the pituitary is the source of excessive ACTH. ACTH = adrenocorticotropic hormone CD = Cushing disease CRH = corticotrophin-releasing hormone CS = Cushing syndrome DDAVP = desmopressin EAS = ectopic ACTH secretion IJVS = internal jugular vein sampling IPSS = inferior petrosal sinus sampling JVS = jugular venous sampling MRI = magnetic resonance imaging.

Gold and gold working in Late Bronze Age Northern Greece

Science.gov (United States)

Vavelidis, M.; Andreou, S.

2008-04-01

Numerous objects of gold displaying an impressive variety of types and manufacturing techniques are known from the Late Bronze Age (LBA) contexts of Mycenaean Greece, but very little is known about the origin and processing of gold during the second millennium b.c. Ancient literature and recent research indicate that northern Greece is probably the richest gold-bearing region in Greece, and yet, very little evidence exists regarding the exploitation of its deposits and the production as well as use of gold in the area during prehistory. The unusual find of a group of small stone crucibles at the prehistoric settlement of Thessaloniki Toumba, one with visible traces of gold melting, proves local production and offers a rare opportunity to examine the process of on-site gold working. Furthermore, the comparison of the chemical composition of prehistoric artefacts from two settlements with those of gold deposits in their immediate areas supports the local extraction of gold and opens up the prospect for some of the Mycenaean gold to have originated in northern Greece. The scarcity of gold items in northern Greek LBA contexts may not represent the actual amount of gold produced and consumed, but could be a result of the local social attitudes towards the circulation and deposition of artefacts from precious metals.

Catheter Displacement into Inferior Epigastric Vein Causing Local Phlebitis and Cellulitis

Directory of Open Access Journals (Sweden)

Noriko Hattori

2012-01-01

Full Text Available Catheter insertion for intravenous hyperalimentation is a commonly and widely used clinical technique. When compared with the incidence of complications associated with insertions into the internal jugular vein or the subclavian vein, complications associated with insertions into the femoral vein are less frequent. In this paper, we describe a very rare complication of femoral vein catheter insertion—namely, catheter displacement into the inferior epigastric vein.

Renal Vein Reconstruction for Harvesting Injury in Kidney Transplantation

Directory of Open Access Journals (Sweden)

Birkan Bozkurt

2014-03-01

Full Text Available Kidney transplantation is the best treatment choice in the end-stage renal disease. In the renal transplantation, renal vein damage or shortness which occurs during cadaveric or living donor nephrectomy causes technical difficulties for surgeons. The lack of the donors already especially cadaveric, the acquirement of the graft, gets very much importance. In this report, it is aimed to share the clinical experiment by which it seen, how anastomosis can become appropriate by using the renal vein which is damaged in the way that anastomosis cannot be done anyway by using cadaveric vena cava graft. The renal vein brought to length for anostomosis which is repaired by using cadaveric vena cava graft, is anastomosed successfully by becoming an end-to-side of the external iliac vein of the recipient. Vascular anastomoses are applied easily in technique. The time of the warm ischemia was under 2 hours and the kidney was functional in the post-operative period. Renal vein trombosis was not observed. The renal vein damage occured during cadaveric or living donor nephrectomy, can be repaired by some methods. In the kidneys in which vein requirement is done, the success rates are rather high although acute tubular necrosis and delayed function can be seen more.

Congestive index of portal vein

International Nuclear Information System (INIS)

Kim, Won Ho; Kim, H. K.; Lee, S. C.; Han, S. H.; Han, K. H.; Chung, J. B.; Choi, H. J.

1989-01-01

In patients with portal hypertension, the blood flow volume is maintained despite decreased blood flow velocity due to enlargement of the vascular cross sectional area. Thus, the 'congestion index' of the portal vein, which is the ratio between the cross sectional area (cm2) and the blood flow velocity (cm/sec) determined by a Doppler ultrasonography, may be a sensitive index by which to assess portal hypertension. We performed Doppler ultrasonography on 24 normal subjects, 14 patients with biopsy proved chronic active hepatitis and 55 patients with liver cirrhosis in order to assess the diagnostic value of the congestion index. The cross sectional area of the portal vein was significantly enlarged and the mean blood flow velocity was significantly reduced in patients with liver cirrhosis compared with controls. However, the blood flow volume was no difference. The congestion index of the portal vein was significantly increased in patients with liver cirrhosis (0.113+0.035) compared with patients with chronic active hepatitis(0.078+0.029) (p<0.001) and controls (0.053+0.016) (p<0.001). The sensitivity, specificity and predictability of the congestion index for detection of patients with the cirrhosis of the liver were 76.4%, 100% and 100% respectively, when the normal range was set at mean+2SD. The results suggest that the congestion index of the portal vein may pla a significant role in diagnosis of portal hypertensive patients

Gold-Mining

DEFF Research Database (Denmark)

Raaballe, J.; Grundy, B.D.

2002-01-01

  Based on standard option pricing arguments and assumptions (including no convenience yield and sustainable property rights), we will not observe operating gold mines. We find that asymmetric information on the reserves in the gold mine is a necessary and sufficient condition for the existence...... of operating gold mines. Asymmetric information on the reserves in the mine implies that, at a high enough price of gold, the manager of high type finds the extraction value of the company to be higher than the current market value of the non-operating gold mine. Due to this under valuation the maxim of market...

Phenotypic heterogeneity in the endothelium of the human vortex vein system.

Science.gov (United States)

Yu, Paula K; Tan, Priscilla E Z; Cringle, Stephen J; McAllister, Ian L; Yu, Dao-Yi

2013-10-01

The vortex vein system is the drainage pathway for the choroidal circulation and serves an important function in the effective drainage of the exceptionally high blood flow from the choroidal circulation. As there are only 4-6 vortex veins, a large volume of blood must be drained from many choroidal veins into each individual vortex vein. The vortex vein system must also cope with passing through tissues of different rigidity and significant pressure gradient as it transverses from the intrao-cular to the extra-ocular compartments. However, little is known about how the vortex vein system works under such complex situations in both physiological and pathological condition. Endothelial cells play a vital role in other vascular systems, but they have not been studied in detail in the vortex vein system. The purpose of this study is to characterise the intracellular structures and morphology in both the intra-and extra-ocular regions of the human vortex vein system. We hypothesise the presence of endothelial phenotypic heterogeneity through the vortex vein system. The inferior temporal vortex vein system from human donor eyes were obtained and studied histologically using confocal microscopy. The f-actin cytoskeleton and nuclei were labelled using Alexa Fluor conjugated Phalloidin and YO-PRO-1. Eight regions of the vortex vein system were examined with the venous endothelium studied in detail with quantitative data obtained for endothelial cell and nuclei size and shape. Significant endothelial phenotypic heterogeneity was found throughout the vortex vein system with the most obvious differences observed between the ampulla and its downstream regions. Variation in the distribution pattern of smooth muscle cells, in particular the absence of smooth muscle cells around the ampulla, was noted. Our results suggest the presence of significantly different haemodynamic forces in different regions of the vortex vein system and indicate that the vortex vein system may play

Isotopic characteristics of two kinds of hydrothermal carbonation in the Maria Lazara gold deposit. Goias Estate of Central Brazil

International Nuclear Information System (INIS)

Pulz, G.; Fuck, R.

1998-01-01

In the hydrothermal halo of the Maria Lazara gold deposit, two kinds of carbonation were identified: pervasive carbonation, which corresponds to the disseminations of calcite in the hydrothermal halo represented by the biotite-sulfide and carbonate-chlorite zones and, venular carbonation expressed by quartz and calcite veins inserted in the inner biotite-sulfide zone show an organic carbon component depleted in C. In the carbonate-chlorite zone the calcite isotopic behavior reflects the Co2 derived from the metamorphism o the basic host-rocks. (author)

Mistakes and Pitfalls Associated with Two-Point Compression Ultrasound for Deep Vein Thrombosis

Directory of Open Access Journals (Sweden)

Tony Zitek, MD

2016-03-01

Full Text Available Introduction: Two-point compression ultrasound is purportedly a simple and accurate means to diagnose proximal lower extremity deep vein thrombosis (DVT, but the pitfalls of this technique have not been fully elucidated. The objective of this study is to determine the accuracy of emergency medicine resident-performed two-point compression ultrasound, and to determine what technical errors are commonly made by novice ultrasonographers using this technique. Methods: This was a prospective diagnostic test assessment of a convenience sample of adult emergency department (ED patients suspected of having a lower extremity DVT. After brief training on the technique, residents performed two-point compression ultrasounds on enrolled patients. Subsequently a radiology department ultrasound was performed and used as the gold standard. Residents were instructed to save videos of their ultrasounds for technical analysis. Results: Overall, 288 two-point compression ultrasound studies were performed. There were 28 cases that were deemed to be positive for DVT by radiology ultrasound. Among these 28, 16 were identified by the residents with two-point compression. Among the 260 cases deemed to be negative for DVT by radiology ultrasound, 10 were thought to be positive by the residents using two-point compression. This led to a sensitivity of 57.1% (95% CI [38.8-75.5] and a specificity of 96.1% (95% CI [93.8-98.5] for resident-performed two-point compression ultrasound. This corresponds to a positive predictive value of 61.5% (95% CI [42.8-80.2] and a negative predictive value of 95.4% (95% CI [92.9-98.0]. The positive likelihood ratio is 14.9 (95% CI [7.5-29.5] and the negative likelihood ratio is 0.45 (95% CI [0.29-0.68]. Video analysis revealed that in four cases the resident did not identify a DVT because the thrombus was isolated to the superior femoral vein (SFV, which is not evaluated by two-point compression. Moreover, the video analysis revealed that the

Finger Vein Recognition Based on Personalized Weight Maps

Science.gov (United States)

Yang, Gongping; Xiao, Rongyang; Yin, Yilong; Yang, Lu

2013-01-01

Finger vein recognition is a promising biometric recognition technology, which verifies identities via the vein patterns in the fingers. Binary pattern based methods were thoroughly studied in order to cope with the difficulties of extracting the blood vessel network. However, current binary pattern based finger vein matching methods treat every bit of feature codes derived from different image of various individuals as equally important and assign the same weight value to them. In this paper, we propose a finger vein recognition method based on personalized weight maps (PWMs). The different bits have different weight values according to their stabilities in a certain number of training samples from an individual. Firstly we present the concept of PWM, and then propose the finger vein recognition framework, which mainly consists of preprocessing, feature extraction, and matching. Finally, we design extensive experiments to evaluate the effectiveness of our proposal. Experimental results show that PWM achieves not only better performance, but also high robustness and reliability. In addition, PWM can be used as a general framework for binary pattern based recognition. PMID:24025556

Finger Vein Recognition Based on Personalized Weight Maps

Directory of Open Access Journals (Sweden)

Lu Yang

2013-09-01

Full Text Available Finger vein recognition is a promising biometric recognition technology, which verifies identities via the vein patterns in the fingers. Binary pattern based methods were thoroughly studied in order to cope with the difficulties of extracting the blood vessel network. However, current binary pattern based finger vein matching methods treat every bit of feature codes derived from different image of various individuals as equally important and assign the same weight value to them. In this paper, we propose a finger vein recognition method based on personalized weight maps (PWMs. The different bits have different weight values according to their stabilities in a certain number of training samples from an individual. Firstly we present the concept of PWM, and then propose the finger vein recognition framework, which mainly consists of preprocessing, feature extraction, and matching. Finally, we design extensive experiments to evaluate the effectiveness of our proposal. Experimental results show that PWM achieves not only better performance, but also high robustness and reliability. In addition, PWM can be used as a general framework for binary pattern based recognition.

Deep Vein Thrombosis

Centers for Disease Control (CDC) Podcasts

2012-04-05

This podcast discusses the risk for deep vein thrombosis in long-distance travelers and ways to minimize that risk.  Created: 4/5/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 4/5/2012.

Characterization of a porcine model of chronic superficial varicose veins.

Science.gov (United States)

Jones, Gregory T; Grant, Mark W; Thomson, Ian A; Hill, B Geraldine; van Rij, André M

2009-06-01

Previous animal models of venous disease, while inducing venous hypertension and valvular insufficiency, do not produce superficial varicose veins. In this study, we aimed to develop and characterize a pig-based model of superficial varicose veins. Right femoral arteriovenous fistulae (AVF) were surgically fashioned in young adult pigs. Animals were examined at postoperative times up to 15 weeks to determine the development of varicose veins and measurement of both blood pressure and flow velocities within the superficial thigh veins. Histology and vascular corrosion casts were used to characterize the resulting structural venous alterations. Porcine pathophysiological features were compared with those of human primary superficial varicose veins. Gross superficial varicosities developed over the ipsilateral medial thigh region after an initial lag period of 1-2 weeks. Veins demonstrated retrograde filling with valvular incompetence, and a moderate, non-pulsatile, venous hypertension, which was altered by changes in posture and Valsalva. Venous blood flow velocities were elevated to 15-30 cm/s in varicose veins. Structurally, pig varicose veins were enlarged, tortuous, had valvular degeneration, and regions of focal medial atrophy with or without overlying intimal thickening. The superficial varicose veins, which developed within this model, have a pathophysiology that is consistent with that observed in humans. The porcine femoral AVF model is proposed as a suitable experimental model to evaluate the pathobiology of superficial venous disease. It may also be suitable for the evaluation of treatment interventions including drug therapy.

[Portal perfusion with right gastroepiploic vein flow in liver transplant].

Science.gov (United States)

Mendoza-Sánchez, Federico; Javier-Haro, Francisco; Mendoza-Medina, Diego Federico; González-Ojeda, Alejandro; Cortés-Lares, José Antonio; Fuentes-Orozco, Clotilde

Liver transplantation in patients with liver cirrhosis, portal vein thrombosis, and cavernous transformation of the portal vein, is a complex procedure with high possibility of liver graft dysfunction. It is performed in 2-19% of all liver transplants, and has a significantly high mortality rate in the post-operative period. Other procedures to maintain portal perfusion have been described, however there are no reports of liver graft perfusion using right gastroepiploic vein. A 20 year-old female diagnosed with cryptogenic cirrhosis, with a Child-Pugh score of 7 points (class "B"), and MELD score of 14 points, with thrombosis and cavernous transformation of the portal vein, severe portal hypertension, splenomegaly, a history of upper gastrointestinal bleeding due to oesophageal varices, and left renal agenesis. The preoperative evaluation for liver transplantation was completed, and the right gastroepiploic vein of 1-cm diameter was observed draining to the infrahepatic inferior vena cava and right suprarenal vein. An orthotopic liver transplantation was performed from a non-living donor (deceased on January 30, 2005) using the Piggy-Back technique. Portal vein perfusion was maintained using the right gastroepiploic vein, and the outcome was satisfactory. The patient was discharged 13 days after surgery. Liver transplantation was performed satisfactorily, obtaining an acceptable outcome. In this case, the portal perfusion had adequate blood flow through the right gastroepiploic vein. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

A study of images of Projective Angles of pulmonary veins

Energy Technology Data Exchange (ETDEWEB)

Wang Jue [Beijing Anzhen Hospital, Beijing (China); Zhaoqi, Zhang [Beijing Anzhen Hospital, Beijing (China)], E-mail: zhaoqi5000@vip.sohu.com; Yu Wei; Miao Cuilian; Yan Zixu; Zhao Yike [Beijing Anzhen Hospital, Beijing (China)

2009-09-15

Aims: In images of magnetic resonance and computed tomography (CT) there are visible angles between pulmonary veins and the coronary, transversal or sagittal section of body. In this study these angles are measured and defined as Projective Angles of pulmonary veins. Several possible influential factors and characters of distribution are studied and analyzed for a better understanding of this imaging anatomic character of pulmonary veins. And it could be the anatomic base of adjusting correctly the angle of the central X-ray of the angiography of pulmonary veins undergoing the catheter ablation of atrial fibrillation (AF). Method: Images of contrast enhanced magnetic resonance angiography (CEMRA) and contrast enhanced computer tomography (CECT) of the left atrium and pulmonary veins of 137 health objects and patients with atrial fibrillation (AF) are processed with the technique of post-processing, and Projective Angles to the coronary and transversal sections are measured and analyzed statistically. Result: Project Angles of pulmonary veins are one of real and steady imaging anatomic characteristics of pulmonary veins. The statistical distribution of variables is relatively concentrated, with a fairly good representation of average value. It is possible to improve the angle of the central X-ray according to the average value in the selective angiography of pulmonary veins undergoing the catheter ablation of AF.

Adrenal vein catheterization. Anatomic considerations

Energy Technology Data Exchange (ETDEWEB)

El-Sherief, M.A. (Akademiska Sjukhuset, Uppsala (Sweden))

1982-01-01

Twenty post-mortem specimens and 93 phlebographies (56 right side, 37 left side) from 44 patients were investigated with respect to the adrenal venous anatomy. At autopsy, the venous orifices displayed in the area of adrenal drainage were injected bilaterally to identify the adrenal vein(s), the surrounding channels and the presence of interconnections. The findings were correlated with those at clinical phlebography, and the different sources of error were elicited. These were mainly found on the right side. Some guidelines are suggested in the hope that these will contribute to eliminate misconceptions.

Treatment of hepatic encephalopathy by retrograde transcaval coil embolization of an ileal vein-to-right gonadal vein portosystemic shunt

International Nuclear Information System (INIS)

Nishie, Akihiro; Yoshimitsu, Kengo; Honda, Hiroshi; Kaneko, Kuniyuki; Kuroiwa, Toshiro; Fukuya, Tatsuro; Irie, Hiroyuki; Ninomiya, Toshiharu; Yoshimitsu, Takahiro; Hirakata, Hideki; Okuda, Seiya; Masuda, Kouji

1997-01-01

A 43-year-old non-cirrhotic woman suffered from encephalopathy caused by an extrahepatic portosystemic shunt between the ileal vein and inferior vena cava via the right gonadal vein. Percutaneous transcatheter embolization with stainless steel coils was performed by the retrograde systemic venous approach. Encephalopathy improved dramatically

Vein-type uranium deposits

International Nuclear Information System (INIS)

Rich, R.A.; Holland, H.D.; Petersen, U.

1975-01-01

A critical review is presented of published data bearing on the mineralogy, paragenesis, geochemistry, and origin of veiw-type uranium deposits. Its aim is to serve as a starting point for new research and as a basis for the development of new exploration strategies. During the formation of both vein and sandstone types of deposits uranium seems to have been dissolved by and transported in rather oxidized solutions, and deposited where these solutions encountered reducing agents such as carbon, sulfides, ferrous minerals and hydrocarbons. Granitic rocks abnormally enriched in uranium have apparently been the most common source for uranium in vein-type deposits. Oxidizing solutions have been derived either from the surface or from depth. Surface solutions saturated with atmospheric oxygen have frequently passed through red bed or clean sandstone conduits on their way to and from uranium source rocks. Deep solutions of non-surface origin have apparently become sufficiently oxidizing by passage through and equilibration with red beds. The common association of clean sandstones or red beds with uranium-rich granites in the vicinity of vein-type uranium deposits is probably not fortuitous, and areas where these rock types are found together are considered particularly favorable targets for uranium exploration

Interposition vein cuffs.

Science.gov (United States)

Harris, P; Da Silva, T; How, T

1996-01-01

A vein cuff interposed at the distal anastomosis between a prosthetic vascular graft and a recipient infrageniculate artery improves the chances of continued patency of the graft, at least in the short and medium term. The mode of effect appears to be suppression or modification of anastomotic myointimal hyperplasia (MIH). In the event of graft failure the recipient artery and run-off vessels remain free from MIH and their patency is preserved thereby improving the prospects for further vascular reconstruction and limb salvage. The mechanisms by which interposition vein cuffs might modulate MIH are reviewed. Experimental evidence is described to show that the geometry of a cuffed anastomosis promotes a characteristic haemodynamic flow structure with a stable vortex. It is suggested that this vortex exerts greater shear stress upon the wall of the artery than the normal laminar flow observed in conventional anastomoses. High shear stress is known to inhibit MIH.

Mineral resources of the South Mccullough Mountains Wilderness Study Area, Clark County, Nevada

International Nuclear Information System (INIS)

DeWitt, E.; Anderson, J.L.; Barton, H.N.; Jachens, R.C.; Podwysocki, M.H.; Brickey, D.W.; Close, T.J.

1989-01-01

The authors present a study of 19,558 acres of the South McCullough Mountains Wilderness Study Area. The study area contains no identified mineral resources and has no areas of high mineral resource potential. However, five areas that make up 20 percent of the study area have a moderate potential either for undiscovered silver, gold, lead, copper, and zinc resources in small vein deposits; for lanthanum and other rare-earth elements, uranium, thorium, and niobium in medium-size carbonatite bodies and dikes; for tungsten and copper in small- to medium-size vein deposits; or for silver and gold in small vein or breccia-pipe deposits. Six areas that makeup 24 percent of the study area have an unknown resource potential either for gold, silver, lead, and copper in small vein deposits; for gold, silver, lead, zinc, copper, and arsenic in small vein or breccia-pipe deposits; for lanthanum and other rare-earth elements, uranium, thorium, and niobium in medium-size carbonatite bodies and dikes; or for tungsten and copper in small vein deposits

Gold Nanoparticles Obtained by Bio-precipitation from Gold(III) Solutions

International Nuclear Information System (INIS)

Gardea-Torresdey, J.L.; Tiemann, K.J.; Gamez, G.; Dokken, K.; Tehuacanero, S.; Jose-Yacaman, M.

1999-01-01

The use of metal nanoparticles has shown to be very important in recent industrial applications. Currently gold nanoparticles are being produced by physical methods such as evaporation. Biological processes may be an alternative to physical methods for the production of gold nanoparticles. Alfalfa biomass has shown to be effective at passively binding and reducing gold from solutions containing gold(III) ions and resulting in the formation of gold(0) nanoparticles. High resolution microscopy has shown that five different types of gold particles are present after reaction with gold(III) ions with alfalfa biomass. These particles include: fcc tetrahedral, hexagonal platelet, icosahedral multiple twinned, decahedral multiple twinned, and irregular shaped particles. Further analysis on the frequency of distribution has shown that icosahedral and irregular particles are more frequently formed. In addition, the larger particles observed may be formed through the coalescence of smaller particles. Through modification of the chemical parameters, more uniform particle size distribution may be obtained by the alfalfa bio-reduction of gold(III) from solution

Internal jugular vein: Peripheral vein adrenocorticotropic hormone ratio in patients with adrenocorticotropic hormone-dependent Cushing′s syndrome: Ratio calculated from one adrenocorticotropic hormone sample each from right and left internal jugular vein during corticotrophin releasing hormone stimulation test

Directory of Open Access Journals (Sweden)

Sachin Chittawar

2013-01-01

Full Text Available Background: Demonstration of central: Peripheral adrenocorticotropic hormone (ACTH gradient is important for diagnosis of Cushing′s disease. Aim: The aim was to assess the utility of internal jugular vein (IJV: Peripheral vein ACTH ratio for diagnosis of Cushing′s disease. Materials and Methods: Patients with ACTH-dependent Cushing′s syndrome (CS patients were the subjects for this study. One blood sample each was collected from right and left IJV following intravenous hCRH at 3 and 5 min, respectively. A simultaneous peripheral vein sample was also collected with each IJV sample for calculation of IJV: Peripheral vein ACTH ratio. IJV sample collection was done under ultrasound guidance. ACTH was assayed using electrochemiluminescence immunoassay (ECLIA. Results: Thirty-two patients participated in this study. The IJV: Peripheral vein ACTH ratio ranged from 1.07 to 6.99 ( n = 32. It was more than 1.6 in 23 patients. Cushing′s disease could be confirmed in 20 of the 23 cases with IJV: Peripheral vein ratio more than 1.6. Four patients with Cushing′s disease and 2 patients with ectopic ACTH syndrome had IJV: Peripheral vein ACTH ratio less than 1.6. Six cases with unknown ACTH source were excluded for calculation of sensitivity and specificity of the test. Conclusion: IJV: Peripheral vein ACTH ratio calculated from a single sample from each IJV obtained after hCRH had 83% sensitivity and 100% specificity for diagnosis of CD.

Convolutional Neural Network-Based Finger-Vein Recognition Using NIR Image Sensors.

Science.gov (United States)

Hong, Hyung Gil; Lee, Min Beom; Park, Kang Ryoung

2017-06-06

Conventional finger-vein recognition systems perform recognition based on the finger-vein lines extracted from the input images or image enhancement, and texture feature extraction from the finger-vein images. In these cases, however, the inaccurate detection of finger-vein lines lowers the recognition accuracy. In the case of texture feature extraction, the developer must experimentally decide on a form of the optimal filter for extraction considering the characteristics of the image database. To address this problem, this research proposes a finger-vein recognition method that is robust to various database types and environmental changes based on the convolutional neural network (CNN). In the experiments using the two finger-vein databases constructed in this research and the SDUMLA-HMT finger-vein database, which is an open database, the method proposed in this research showed a better performance compared to the conventional methods.

The vein collar

DEFF Research Database (Denmark)

Lundgren, F; Schroeder, Torben Veith

2012-01-01

Randomized studies evaluating the effect of a vein collar at the distal anastomosis of PTFE-grafts show conflicting results. The study of the Joint Vascular Research Group (JVRG) of UK found improved primary patency while the Scandinavian Miller Collar Study (SCAMICOS) found neither any effect...

Mesenteric vein thrombosis after percitaneous transhepatic portal vein catheterisation for the localisation of an insulinoma

International Nuclear Information System (INIS)

Luska, G.; Langer, H.E.; Le Blanc, S.; Medizinische Hochschule Hannover

1984-01-01

The authors report on a fatal mesenteric vein thrombosis following an uncomplicated percutaneous transhepatic portal vein catheterisation for the localisation of an insulinoma. Several hours after the procedure the patient developed an acute abdomen. An emergency laparotomy revealed a haemorrhagic infarct of the ileum. The resected specimen showed an acute phlebitis with fresh thrombus. The cause of the phlebothrombosis was thought to be intimal damage from high osmolar contrast medium. There was no evidence of damage due to the catheder, either on the phlebogram or pathologically. (orig.) [de

Incidental retroaortic left innominate vein in adult patient

Directory of Open Access Journals (Sweden)

Alexandre Semionov, MD, PhD

2017-09-01

Full Text Available Retro-aortic left innominate vein is a rare vascular abnormality, usually associated with congenital heart disease. Here we report a case of isolated retro-aortic left innominate vein in an adult female.

TrapEase inferior vena cava filter placement: use of the subclavian vein.

Science.gov (United States)

Stone, Patrick A; Aburahma, Ali F; Hass, Stephen M; Hofeldt, Matthew J; Zimmerman, William B; Deel, John T; Deluca, John A

2004-01-01

The purpose of this paper was to evaluate the safety and technical success of TrapEase inferior vena cava filter placement via the subclavian vein. As of yet, no reports in the literature have specifically investigated the use of the subclavian vein as a route for deploying TrapEase vena cava filters. Retrospective chart review was conducted of 135 patients with attempted TrapEase inferior vena cava filter placement over a 2-year period. In a majority of cases, the choice of subclavian vein approach was based primarily on surgeon preference. Other circumstances for subclavian vein deployment included cervical immobilization secondary to trauma, desire for concomitant placement of a subclavian long-term central venous access catheter, and patient body habitus limiting exposure to the internal jugular vein. One hundred and thirty-five filters were placed over this 2-year period. The internal jugular vein approach was used in 56 patients, the femoral vein approach in 39 patients, and the subclavian vein approach in 40 patients. Thirty-nine of the 40 TrapEase filter placements using the subclavian vein were successful. Twenty-six were deployed through the right subclavian vein and 14 through the left subclavian vein. The single failed subclavian deployment was due to the inability to pass the guidewire adequately into the inferior vena cava after successful cannulation of the right subclavian vein. The average deployment time for subclavian vein placement was 26 minutes when TrapEase filter placement was the only procedure performed. No insertional complications were encountered, specifically no pneumothoraces confirmed by chest radiography or fluoroscopy. The subclavian vein provides an alternative site of access for the TrapEase inferior vena cava filter. This route is comparable to other alternative methods evaluated both in average deployment time and complication occurrence. Furthermore, the subclavian vein route is valuable in patients with limited central access

Intravitreal triamcinolone acetonide injections in the treatment of retinal vein occlusions.

Science.gov (United States)

Roth, Daniel B; Cukras, Catherine; Radhakrishnan, Ravi; Feuer, William J; Yarian, David L; Green, Stuart N; Wheatley, Harold M; Prenner, Jonathan

2008-01-01

To report the visual acuity response after intravitreal triamcinolone injection in patients with macular edema due to retinal vein occlusions. Retrospective nonrandomized interventional series of 172 consecutive patients with macular edema due to retinal vein occlusions who were treated with intravitreal triamcinolone acetonide injection. Patients underwent Snellen visual acuity testing and ophthalmoscopic examination at baseline and 1, 3, 6, and 12 months after intravitreal triamcinolone acetonide injection. All subtypes of retinal vein occlusions showed significant improvements in mean visual acuity 1 month after injection. This improvement in visual acuity was maintained over the 12-month period for all but the central retinal vein occlusion group. Seventy-one (41.3%) of the 172 patients received more than one intravitreal triamcinolone injection for unresolved or recurrent macular edema. This study demonstrates a benefit associated with intravitreal triamcinolone acetonide injection for retinal vein occlusions that was maintained by patients with branch retinal vein occlusions and hemiretinal vein occlusions over a 12-month period. Visual acuity improvement was not maintained in patients with central retinal vein occlusions with this course of treatment.

Size fraction assaying of gold bearing rocks (for gold extraction) by ...

African Journals Online (AJOL)

A novel method has been developed for processing and extraction of gold from gold bearing rocks for use by small-scale gold miners in Ghana. The methodology involved crushing of gold bearing hard rocks to fine particles to form a composite sample and screening at a range of sizes. Gold distribution in the composite ...

Robust finger vein ROI localization based on flexible segmentation.

Science.gov (United States)

Lu, Yu; Xie, Shan Juan; Yoon, Sook; Yang, Jucheng; Park, Dong Sun

2013-10-24

Finger veins have been proved to be an effective biometric for personal identification in the recent years. However, finger vein images are easily affected by influences such as image translation, orientation, scale, scattering, finger structure, complicated background, uneven illumination, and collection posture. All these factors may contribute to inaccurate region of interest (ROI) definition, and so degrade the performance of finger vein identification system. To improve this problem, in this paper, we propose a finger vein ROI localization method that has high effectiveness and robustness against the above factors. The proposed method consists of a set of steps to localize ROIs accurately, namely segmentation, orientation correction, and ROI detection. Accurate finger region segmentation and correct calculated orientation can support each other to produce higher accuracy in localizing ROIs. Extensive experiments have been performed on the finger vein image database, MMCBNU_6000, to verify the robustness of the proposed method. The proposed method shows the segmentation accuracy of 100%. Furthermore, the average processing time of the proposed method is 22 ms for an acquired image, which satisfies the criterion of a real-time finger vein identification system.

Robust Finger Vein ROI Localization Based on Flexible Segmentation

Directory of Open Access Journals (Sweden)

Dong Sun Park

2013-10-01

Full Text Available Finger veins have been proved to be an effective biometric for personal identification in the recent years. However, finger vein images are easily affected by influences such as image translation, orientation, scale, scattering, finger structure, complicated background, uneven illumination, and collection posture. All these factors may contribute to inaccurate region of interest (ROI definition, and so degrade the performance of finger vein identification system. To improve this problem, in this paper, we propose a finger vein ROI localization method that has high effectiveness and robustness against the above factors. The proposed method consists of a set of steps to localize ROIs accurately, namely segmentation, orientation correction, and ROI detection. Accurate finger region segmentation and correct calculated orientation can support each other to produce higher accuracy in localizing ROIs. Extensive experiments have been performed on the finger vein image database, MMCBNU_6000, to verify the robustness of the proposed method. The proposed method shows the segmentation accuracy of 100%. Furthermore, the average processing time of the proposed method is 22 ms for an acquired image, which satisfies the criterion of a real-time finger vein identification system.

Robust Finger Vein ROI Localization Based on Flexible Segmentation

Science.gov (United States)

Lu, Yu; Xie, Shan Juan; Yoon, Sook; Yang, Jucheng; Park, Dong Sun

2013-01-01

Finger veins have been proved to be an effective biometric for personal identification in the recent years. However, finger vein images are easily affected by influences such as image translation, orientation, scale, scattering, finger structure, complicated background, uneven illumination, and collection posture. All these factors may contribute to inaccurate region of interest (ROI) definition, and so degrade the performance of finger vein identification system. To improve this problem, in this paper, we propose a finger vein ROI localization method that has high effectiveness and robustness against the above factors. The proposed method consists of a set of steps to localize ROIs accurately, namely segmentation, orientation correction, and ROI detection. Accurate finger region segmentation and correct calculated orientation can support each other to produce higher accuracy in localizing ROIs. Extensive experiments have been performed on the finger vein image database, MMCBNU_6000, to verify the robustness of the proposed method. The proposed method shows the segmentation accuracy of 100%. Furthermore, the average processing time of the proposed method is 22 ms for an acquired image, which satisfies the criterion of a real-time finger vein identification system. PMID:24284769

Contact-free palm-vein recognition based on local invariant features.

Directory of Open Access Journals (Sweden)

Wenxiong Kang

Full Text Available Contact-free palm-vein recognition is one of the most challenging and promising areas in hand biometrics. In view of the existing problems in contact-free palm-vein imaging, including projection transformation, uneven illumination and difficulty in extracting exact ROIs, this paper presents a novel recognition approach for contact-free palm-vein recognition that performs feature extraction and matching on all vein textures distributed over the palm surface, including finger veins and palm veins, to minimize the loss of feature information. First, a hierarchical enhancement algorithm, which combines a DOG filter and histogram equalization, is adopted to alleviate uneven illumination and to highlight vein textures. Second, RootSIFT, a more stable local invariant feature extraction method in comparison to SIFT, is adopted to overcome the projection transformation in contact-free mode. Subsequently, a novel hierarchical mismatching removal algorithm based on neighborhood searching and LBP histograms is adopted to improve the accuracy of feature matching. Finally, we rigorously evaluated the proposed approach using two different databases and obtained 0.996% and 3.112% Equal Error Rates (EERs, respectively, which demonstrate the effectiveness of the proposed approach.

Contact-free palm-vein recognition based on local invariant features.

Science.gov (United States)

Kang, Wenxiong; Liu, Yang; Wu, Qiuxia; Yue, Xishun

2014-01-01

Contact-free palm-vein recognition is one of the most challenging and promising areas in hand biometrics. In view of the existing problems in contact-free palm-vein imaging, including projection transformation, uneven illumination and difficulty in extracting exact ROIs, this paper presents a novel recognition approach for contact-free palm-vein recognition that performs feature extraction and matching on all vein textures distributed over the palm surface, including finger veins and palm veins, to minimize the loss of feature information. First, a hierarchical enhancement algorithm, which combines a DOG filter and histogram equalization, is adopted to alleviate uneven illumination and to highlight vein textures. Second, RootSIFT, a more stable local invariant feature extraction method in comparison to SIFT, is adopted to overcome the projection transformation in contact-free mode. Subsequently, a novel hierarchical mismatching removal algorithm based on neighborhood searching and LBP histograms is adopted to improve the accuracy of feature matching. Finally, we rigorously evaluated the proposed approach using two different databases and obtained 0.996% and 3.112% Equal Error Rates (EERs), respectively, which demonstrate the effectiveness of the proposed approach.

Budd-Chiari and inferior caval vein syndromes due to membranous obstruction of the liver veins. Successful treatment with angioplasty and transcaval TIPS

DEFF Research Database (Denmark)

Holland-Fischer, Peter

2004-01-01

The case is presented of a 25-year-old Caucasian patient with Budd-Chiari syndrome due to membranous obstruction of the liver veins and inferior caval vein syndrome as a result of secondary hyperplasia of the caudate lobe of the liver, obstructing the caval vein. Diagnosis was established...... that angioplasty and TIPS are safe and efficient procedures to reduce liver engorgement and complications of portal hypertension in selected patients with Budd-Chiari syndrome....

Retinal vein occlusion: pathophysiology and treatment options

OpenAIRE

Karia, Niral

2010-01-01

Niral KariaDepartment of Ophthalmology, Southend Hospital, Prittlewell Chase, Westcliff on Sea, Essex, United KingdomAbstract: This paper reviews the current thinking about retinal vein occlusion. It gives an overview of its pathophysiology and discusses the evidence behind the various established and emerging treatment paradigms.Keywords: central, hemispheric, branch, retinal vein occlusion, visual loss

Percutaneous closure of patent ductus arteriosus in interrupted inferior caval vein through femoral vein approach

Directory of Open Access Journals (Sweden)

Endale Tefera

2014-01-01

Full Text Available Percutaneous closure of the patent arterial duct in patients with interrupted inferior caval vein poses a technical challenge. A 12-year-old girl with a patent ductus arteriosus (PDA and interrupted inferior caval vein is described in this report. The diagnosis of interrupted inferior caval vein and azygos continuation was made in the catheterization laboratory. A catheter was advanced and snared in the descending aorta. An exchange wire was advanced through the catheter and snared in the descending aorta. Then, an Amplatzer TorqVue 2 delivery sheath was advanced over the wire from the venous side and again snared in the descending aorta. An Amplatzer duct occluder (ADO size 8/6 was advanced through the sheath while still holding the sheath with a snare. The device was opened. The sheath was then unsnared once the aortic disc was completely out. The sheath and the device were pulled back into the duct and the device was successfully implanted. The device was then released and it attained a stable position. An aortic angiogram was performed which showed complete occlusion.

Percutaneous closure of patent ductus arteriosus in interrupted inferior caval vein through femoral vein approach

International Nuclear Information System (INIS)

Tefera, Endale; Bermudez-Cañete, Ramon

2014-01-01

Percutaneous closure of the patent arterial duct in patients with interrupted inferior caval vein poses a technical challenge. A 12-year-old girl with a patent ductus arteriosus (PDA) and interrupted inferior caval vein is described in this report. The diagnosis of interrupted inferior caval vein and azygos continuation was made in the catheterization laboratory. A catheter was advanced and snared in the descending aorta. An exchange wire was advanced through the catheter and snared in the descending aorta. Then, an Amplatzer TorqVue 2 delivery sheath was advanced over the wire from the venous side and again snared in the descending aorta. An Amplatzer duct occluder (ADO) size 8/6 was advanced through the sheath while still holding the sheath with a snare. The device was opened. The sheath was then unsnared once the aortic disc was completely out. The sheath and the device were pulled back into the duct and the device was successfully implanted. The device was then released and it attained a stable position. An aortic angiogram was performed which showed complete occlusion

[Intraosseous veins of the maxilla in the newborn].

Science.gov (United States)

Bogdanov, R A

1975-12-01

The intraosseous veins of the maxilla in newborns grow larger with enlargement of the bone and become disposed in three mutually perpendicular planes. The venous plexus of the alveolar process is large. V. v. vallares are thin and interlace forming a network. The veins of interdental septum are well pronounced. The thick venous network of the periosteum and the mucous membrane of the nasal surface of the palatine process includes the vessels transversal and longitudinal to the nasal septum. The venous loops of the incisor part are of triangular, pentagonal and polygonal shape. The veins of the palatine process are connected with 3-4 large vessels falling into the vessels of the tear duct. The transversal and oblique veins of the oral surface of the palatine process are connected with large vessels disposed in parallel to the medial structure of the hard palate. The venous network of the incisor part of the bone is restricted by densified small arc-shaped plexuses. Two-three largest veins lie sagittally and, connected by arc-shaped anastomoses, are tributaries of the vessels of the palate bone, soft palate and pharynx.

Native gold from the Inagli Pt-Au placer deposit (the Aldan Shield, Russia): geochemical characteristics and implications for possible bedrock sources

Science.gov (United States)

Svetlitskaya, Tatyana V.; Nevolko, Peter A.; Kolpakov, Vladislav V.; Tolstykh, Nadezhda D.

2018-03-01

The Inagli alluvial Pt-Au placer deposit in the Republic of Sakha (Yakutia), Russia, is linked to the Inagli massif, one of the several Uralian-Alaskan-type alkaline-ultrabasic complexes in the Aldan Shield. Gold from the placer is heterogeneous in composition and is represented by three types. Type 1 gold is the most abundant and is characterized by simple Au-Ag alloys with 4-34 wt% Ag, low Cu (up to 0.08 wt%) and negligible Hg, Pt, and Pd contents, and silver-tellurium sulfosalts (Ag-Cu-Te-S-As compounds) in the inclusion suite. Silicate inclusions are biotite, K-feldspar, Fe-Mg amphibole, chlorite, plagioclase, Fe-Mg pyroxene, zircon, and titanite. Distinctive features of this gold type are most similar to those derived from low-sulfidation systems linked to iron oxide copper-gold or iron skarn types of mineralization. The bedrock source of type 1 gold could be related with monzonite to syenite intrusions surrounding the Inagli massif. Distinctive features of type 2 gold include a wide discontinuous range of Ag content (1-18 wt%), elevated Cu (up to 0.5 wt%), and occasional Pd (up to 0.3 wt%) levels, non-detectable Pt and Hg contents, and rare inclusions of simple sulfides (digenite, pyrrhotite) and Na amphibole. Type 3 gold is distinguished by a narrow range in Ag content (5-8 wt%), elevated Hg (0.5-1 wt%) contents, negligible Cu, Pt and Pd levels, and Au-Pb compounds + K-feldspar inclusions. Microchemical characteristics of type 2 and type 3 gold are interpreted as suggestive of an alkaline-magmatic-related fluid. Based on the grain morphology and microchemical signatures, potential bedrock sources for both gold types could be related to the numerous alkaline veins and potassic alteration zones within the dunite core. A comparison of the Inagli and the Kondyor placer gold allows to generate distinctive generic signatures for gold from Uralian-Alaskan-type alkaline-ultrabasic complexes in the Aldan Shield.

Au-As (lead) vein mineralizations of the Cevennes and Chataigneraie regions (French Massif Central). Isotopic characterization (Pb). Mineralizing role of granites in the setting up of these mineralizations

International Nuclear Information System (INIS)

Havard, M.L.

1997-06-01

This work has been carried out in the Frame of the national program 'Geofrance 3D' jointly organized by the French office for geologic and mining researches (BRGM), and the CNRS-INSU/DSPT3. Its aim is the study of the formation of gold-bearing mineralizations of the Variscan chain in the Cevennes and Chataigneraie regions (French Massif Central). In the Cevennes region, the gold-bearing veins are linked with the intrusion of the late-tectonic granodioritic plutons. The aim of this study is to determine the chronology of the mineralizing episodes and to analyze the relationship between the metal concentrates and the setting up of the granites. In the Chataigneraie region, the granites are intrusive in ortho- and para-gneiss series. The hydrothermal activity associated with the contact metamorphism should be responsible for the deposition of gold-bearing wolfram mineralization. The geochemistry of lead isotopes is used to determine the origin of metals in the sulfide mineralizations. The scanning electron microscopy (SEM) is used for the visualization of the microstructure heterogeneities of the minerals and for the quantitative chemical analysis of their successive para-geneses. The comparison between the results obtained in both regions allows to make a difference between their relative degree of erosion and their gold potentialities. (J.S.)

Anatomical variation of thyroid veins on contrast-enhanced multi-detector row computed tomography

Energy Technology Data Exchange (ETDEWEB)

Tomita, Hayato, E-mail: m04149@yahoo.co.jp [Department of Radiology, St. Marianna University School of Medicine, Yokohama City Seibu Hospital, 1197-1 Yasashicho, Asahi-ku, Yokohama, Kanagawa 241-0811 (Japan); Yamada, Takayuki; Murakami, Kenji; Hashimoto, Kazuki; Tazawa, Yoko; Kumano, Reiko [Department of Radiology, St. Marianna University School of Medicine, Yokohama City Seibu Hospital, 1197-1 Yasashicho, Asahi-ku, Yokohama, Kanagawa 241-0811 (Japan); Nakajima, Yasuo [Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa 216-8511 (Japan)

2015-05-15

Highlights: • This is the first study to demonstrate the anatomy of thyroid veins on contrasted-enhanced MDCT. • Identifying the thyroid vein on MDCT prior to selective venous sampling of parathyroid hormone provides clinical information to interventional radiologist. • Detecting especially the inferior thyroid veins with individual variability in numbers, locations, and lengths may have an effect on SVS for HPT and decrease the difficulty and time of the procedure. - Abstract: Objective: The objective of this study was to clarify the anatomical variation of thyroid veins into the systemic vein using contrast-enhanced multi-detector row computed tomography (MDCT). Design and methods: : The subjects were 80 patients (34 males and 46 females; mean age, 50.1 years; age range, 15–92 years) with neck diseases who underwent MDCT. The number and location of inflow points of the thyroid veins into the systemic vein, and the length from the junction of bilateral brachiocephalic veins to the orifice of inferior thyroid vein were investigated by reviewing the axial and coronal images. Results: All superior thyroid veins were detected. Right and left middle thyroid veins were identified in 39 and 29 patients, respectively. Right inferior thyroid veins, left inferior thyroid veins, and common trunks were detected in 43, 46, and 39 patients, respectively; in five patients, two left thyroid veins were identified. All left inferior thyroid veins and 34 common trunks flowed into the innominate vein, while right ones had some variations in inflow sites. Mean lengths were 3.01 ± 1.30 cm (range, 0.5–6.19) and 2.04 ± 0.91 cm (0.5–4.4) in the left inferior thyroid vein and common trunk, and 1.96 ± 1.05 cm (0.81–4.8) and 1.65 ± 0.69 cm (0.63–2.94) in the right one flowing into the right internal jugular vein and the innominate vein, respectively. Conclusions: The numbers and orifices of thyroid veins were identified at high rates on contrast-enhanced MDCT. This

Multidetector CT venography and contrast-enhanced MR venography of the inferior mesenteric vein in paediatric extrahepatic portal vein obstruction

International Nuclear Information System (INIS)

Chennur, Vikash SrinivasaiahSetty; Sharma, Raju; Gamanagatti, Shivanand; Gupta, Arun Kumar; Bhatnagar, Veereshwar; Vishnubhatla, Sreenivas

2011-01-01

Extrahepatic portal vein obstruction (EHPVO) is a common cause of paediatric portal hypertension and the only permanent treatment is shunt surgery. The inferior mesenteric vein (IMV) is a portal venous channel that can be used for the shunt when the splenic vein/superior mesenteric vein is thrombosed or when a lienorenal shunt is not possible. To compare MDCT venography (MDCTV) and contrast-enhanced MR venography (CEMRV) for visualisation of the IMV in children with EHPVO. This was a prospective study of 26 children (4-12 years, median 10 years) who underwent MDCTV and CEMRV. The IMV visualisation was graded using 4- and 2-point scales and the difference in visualisation was assessed by calculating the exact significance probability (P). The IMV was visualised in all children on MDCTV and 25/26 children on CEMRV (96%). The images were diagnostic in 23/26 children (88%) on MDCTV and in 18/26 (69%) children on CEMRV (P = 0.063). MDCTV and CEMRV are comparable for IMV visualisation with a tendency toward MDCTV being superior. (orig.)

Multidetector CT venography and contrast-enhanced MR venography of the inferior mesenteric vein in paediatric extrahepatic portal vein obstruction

Energy Technology Data Exchange (ETDEWEB)

Chennur, Vikash SrinivasaiahSetty; Sharma, Raju; Gamanagatti, Shivanand; Gupta, Arun Kumar [All India Institute of Medical Sciences (AIIMS), Department of Radiology, New Delhi (India); Bhatnagar, Veereshwar [AIIMS, Department of Paediatric Surgery, New Delhi (India); Vishnubhatla, Sreenivas [AIIMS, Department of Biostatistics, New Delhi (India)

2011-03-15

Extrahepatic portal vein obstruction (EHPVO) is a common cause of paediatric portal hypertension and the only permanent treatment is shunt surgery. The inferior mesenteric vein (IMV) is a portal venous channel that can be used for the shunt when the splenic vein/superior mesenteric vein is thrombosed or when a lienorenal shunt is not possible. To compare MDCT venography (MDCTV) and contrast-enhanced MR venography (CEMRV) for visualisation of the IMV in children with EHPVO. This was a prospective study of 26 children (4-12 years, median 10 years) who underwent MDCTV and CEMRV. The IMV visualisation was graded using 4- and 2-point scales and the difference in visualisation was assessed by calculating the exact significance probability (P). The IMV was visualised in all children on MDCTV and 25/26 children on CEMRV (96%). The images were diagnostic in 23/26 children (88%) on MDCTV and in 18/26 (69%) children on CEMRV (P = 0.063). MDCTV and CEMRV are comparable for IMV visualisation with a tendency toward MDCTV being superior. (orig.)

Primary leiomyosarcoma of the innominate vein.

Science.gov (United States)

Illuminati, Giulio; Miraldi, Fabio; Mazzesi, Giuseppe; D'urso, Antonio; Ceccanei, Gianluca; Bezzi, Marcello

2007-01-01

Primary venous leiomyosarcoma is rare. We report the case of a primary leiomyosarcoma of the left innominate vein, with neoplastic thrombus extending into the left jugular and subclavian veins. The tumor was curatively resected en bloc with anterior mediastinal and laterocervical lymphatics, through a median sternotomy prolonged into left cervicotomy. Primary venous sarcomas may be associated with prolonged survival in individual cases, with curative resection recommended as the standard treatment, in the absence of distant spread.

Right top pulmonary vein: Evaluation with 64 section multidetector computed tomography

International Nuclear Information System (INIS)

Arslan, Gokhan; Dincer, Elvan; Kabaalioglu, Adnan; Ozkaynak, Can

2008-01-01

Purpose: To evaluate the incidence and anatomic features of the rare variant of the pulmonary veins named 'right top pulmonary vein' as depicted with 64 section multidetector computed tomography (MDCT). Materials and methods: MDCT of 610 patients obtained over 12 months period for diagnosis of suspected thoracic or cardiac pathology were routinely reviewed in transverse and 3D images. The frequency of right top pulmonary vein (RTPV) was determined and anatomic features were also documented. Results: Right top pulmonary vein (RTPV) is a supernumerary vein arising from the roof of the right part of the left atrium separately from the orifice of the right superior pulmonary vein. It crosses behind the intermediate bronchus and drains mainly posterior segment of the right upper lobe but also receives few subsegmental branches of superior segment of the right lower lobe. It was detected in 2.2% of patients (14/610). The mean diameter of RTPV was 5.1 mm. Conclusion: The RTPV is a rare venous drainage variation of pulmonary veins. It is important to be aware of this anatomic pattern for avoiding misinterpretation of pulmonary venographic findings, inadvertent ablation of pulmonary vein and perioperative bleeding during video assisted thorocoscopic lobectomy

Regional heterogeneity of endothelial cells in the porcine vortex vein system.

Science.gov (United States)

Tan, Priscilla Ern Zhi; Yu, Paula K; Cringle, Stephen J; Morgan, William H; Yu, Dao-Yi

2013-09-01

The aim of this study was to investigate whether region-dependent endothelial heterogeneity is present within the porcine vortex vein system. The superior temporal vortex vein in young adult pig eyes were dissected out and cannulated. The intact vortex vein system down to the choroidal veins was then perfused with labels for f-actin and nucleic acid. The endothelial cells within the choroidal veins, pre-ampulla, anterior portion of the ampulla, mid-ampulla, posterior portion of the ampulla, post-ampulla, intra-scleral canal and the extra-ocular vortex vein regions were studied in detail using a confocal microscopy technique. The endothelial cell and nuclei length, width, area and perimeter were measured and compared between the different regions. Significant regional differences in the endothelial cell and nuclei length, width, area and perimeter were observed throughout the porcine vortex vein system. Most notably, very narrow and elongated endothelia were found in the post-ampulla region. A lack of smooth muscle cells was noted in the ampulla region compared to other regions. Heterogeneity in endothelial cell morphology is present throughout the porcine vortex vein system and there is a lack of smooth muscle cells in the ampulla region. This likely reflects the highly varied haemodynamic conditions and potential blood flow control mechanisms in different regions of the vortex vein system. Copyright © 2013 Elsevier Inc. All rights reserved.

Management Strategy for Patients With Chronic Subclavian Vein Thrombosis.

Science.gov (United States)

Keir, Graham; Marshall, M Blair

2017-02-01

We performed a systematic review to determine best practice for the management of patients with chronic or subacute subclavian vein thrombosis. This condition is best managed with surgical excision of the first rib followed by long-term anticoagulation. Interventional techniques aimed at restoring patency are ineffective beyond 2 weeks postthrombosis. Additional therapeutic options should be made based on the severity of symptoms as well as vein status. Patients with milder symptoms are given decompression surgery followed by anticoagulation whereas patients with more severe symptoms are considered for either a jugular vein transposition or saphenous patch based on the vein characteristics. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

MULTIPLE VARIATIONS OF THE SUPERFICIAL JUGULAR VEINS: CASE REPORT AND CLINICAL RELEVANCE

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George Paraskevas

2014-01-01

Full Text Available The jugular venous system constitutes the primary venous drainage of the head and neck. It includes a profundus or subfascial venous system, formed by the two internal jugular veins, and a superficial or subcutaneous one, formed by the two anterior and two external jugular veins. We report one case of unilateral anatomical variations of the external and anterior jugular veins. Particularly, on the right side, three external jugular veins co-existed with two anterior jugular veins. Such a combination of venous anomalies is extremely rare. The awareness of the variability of these veins is essential to anesthesiologists and radiologists, since the external jugular vein constitutes a common route for catheterization. Their knowledge is also important to surgeons performing head and neck surgery.

Surgery for acquired cardiovascular disease: antiseptic treatment of contaminated vein grafts.

Science.gov (United States)

Schmidt, F P; Peivandi, A A; Kohnen, W; Jansen, B

2014-04-01

Saphenous vein grafts harvested for use as bypass conduits can be contaminated intraoperatively, e.g. by being inadvertently dropped to the floor of the operating room (OR). This study was performed to investigate microorganisms most likely contaminating vein grafts and to assess the possible efficacy of measures to treat potentially contaminated vein grafts antiseptically for further use. In a first step we determined the microbiological flora of the OR using surface cultures and cultures from intentionally dropped vein grafts. Several antiseptic agents (PVP-iodine 10%, octenidinhydrochloride 0.1%, polyhexanide 1%) were evaluated for their in vitro efficacy to disinfect artificially contaminated vein segments. The most promising antiseptic regimen was tested on veins contaminated in a real OR setting. Finally, we tested for possible alterations in mechanical properties of the veins caused by antiseptic treatment. Coagulase-negative staphylococci where the predominant bacteria recovered from the OR with 59.9%. Antiseptic treatment with a combination of octenidine and PVP-iodine resulted in a higher rate of negative cultures than any single agent. Treatment of 50 saphenous vein grafts contaminated in the OR with the combination regimen resulted in only 3 positive cultural results within 7 days. Mechanical tear-stress testing comparing antiseptically treated vein grafts with controls showed no difference in their resistance to tear stress. Antiseptic treatment of contaminated vein grafts was shown to be effective in a high percentage of cases without altering mechanical properties of grafts and may be an option for the surgeon in case of a contamination.

Clinicopathological comparisons of open vein harvesting and endoscopic vein harvesting in coronary artery bypass grafting patients in Mashhad.

Science.gov (United States)

Amouzeshi, Ahmad; Teshnisi, Mohamad Abbassi; Zirak, Nahid; Shamloo, Alireza Sepehri; Hoseinikhah, Hamid; Alizadeh, Behzad; Moeinipour, Aliasghar

2016-01-01

Harvesting of the greater saphenous vein is almost an inevitable part of coronary artery bypass grafting (CABG) operations, and it is done by two main techniques, i.e., conventional or open vein harvesting (OVH) and the minimally-invasive endoscopic vein harvesting (EVH). This study aimed to compare these two techniques in off-pump CABG procedures with respect to clinical and pathological outcomes. This cohort study was conducted on CABG candidates during a one-year period from October 2013 through September 2014 in the Department of Cardiac Surgery at Mashhad University of Medical Sciences. Eighty-seven patients voluntarily underwent EVH, and another 86 patients matched for age, gender, and other cardiovascular risk factors were selected for OVH. They were followed up for six weeks, and the main outcome measures were infections of the wound, pain, duration of hospital stay, and the costs of hospitalization. Paired sample t-test, independent t-test, or their non-parametric equivalents and the chi-squared test were used by SPSS version 17.0 for data analysis. The mean duration of time for vein harvesting was shorter in the EVH group (p < 0.001), and the pain score was lower (p = 0.04). No infections occurred at the site of the wound. The length of hospital stay was not significantly different for the two groups (OVH versus EVH: 8.5 ± 3.3 versus 8.4 ± 3.2 days; p-value: 0.08). Hospitalization costs were significantly higher in the EVH group (OVH versus EVH: 5.8 ± 4.7 versus 7.3 ± 2.0 million Tomman; p-value: 0.008), yet no difference was diagnosed with respect to endothelial damage in the vein grafts harvested by the EVH and OVH techniques. EVH is considered as a minimally invasive and safe vein harvesting technique in our Center, and it can reduce the harvesting time and post-operative pain. In addition, its efficiency was similar to that of OVH.

Leiomyosarcoma of inferior vena cava involving bilateral renal veins: Surgical challenges and reconstruction with upfront saphenous vein interposition graft for left renal vein outflow

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Rishi Nayyar

2010-01-01

Full Text Available Leiomyosarcoma of inferior vena cava (IVC involving bilateral renal veins presents a surgical challenge. Herein, we report the successful management of two such cases using restoration of left renal venous outflow by saphenous vein interposition graft as first step of surgery. Then radical resection of tumor and right kidney was done. IVC was lastly reconstructed using Gore-Tex graft. This report highlights the surgical challenges to ensure radical resection. Furthermore, the importance of restoring left renal outflow in presence of concomitant right nephrectomy is discussed. Both the patients were disease free at six months with no loss of left renal glomerular filtration rate.

Gold prices

OpenAIRE

Joseph G. Haubrich

1998-01-01

The price of gold commands attention because it serves as an indicator of general price stability or inflation. But gold is also a commodity, used in jewelry and by industry, so demand and supply affect its pricing and need to be considered when gold is a factor in monetary policy decisions.

Beta irradiation inhibits neo-intimal formation in vein grafts

International Nuclear Information System (INIS)

Lang Xiaoou; Ji Shenquan; Zeng Ke; Li Jun; Liu Bingbing; Ma Wenfeng; Zhang Qiang

2002-01-01

Objective: The study was to evaluate the effect of beta irradiation on intimal proliferation response in vein grafts. Methods: An autogenous vein graft model was established in 40 rats by transplanting internal branch of jugular vein to carotid artery by end-to-end anastomosis. The vein was irradiated by 32 P before anastomosis. Four dose schedules were studied: (1) control graft (nonirradiated); (2) irradiated with 8 Gy; (3) 18 Gy; and (4) 36 Gy. The grafted veins were harvested at 2 weeks after the operation. IH (intimal hyperplasia) and SMC (smooth muscle cell) proliferation were histologically and immuno-histochemically observed and analyzed by a computer digitalising system. Results: In 18 Gy and 36 Gy-irradiated grafts compared with the control, there was a significant decrease in the average intimal thickness (P 0.05). Immunohistochemical analysis of PCNA indicated decrease of positive cells in both 18 Gy and 36 Gy groups compared with 8 Gy and the control group (P 0.05) groups, and there was also no significant difference between 8 Gy and the control group (P > 0.05). Conclusion: These preliminary results demonstrate that proper dose of beta irradiation in vein graft inhibits smooth muscle cells proliferation and neo-intimal hyperplasia in rat

Geometric Analysis of Vein Fracture Networks From the Awibengkok Core, Indonesia

Science.gov (United States)

Khatwa, A.; Bruhn, R. L.; Brown, S. R.

2003-12-01

Fracture network systems within rocks are important features for the transportation and remediation of hazardous waste, oil and gas production, geothermal energy extraction and the formation of vein fillings and ore deposits. A variety of methods, including computational and laboratory modeling have been employed to further understand the dynamic nature of fractures and fracture systems (e.g. Ebel and Brown, this session). To substantiate these studies, it is also necessary to analyze the characteristics and morphology of naturally occurring vein systems. The Awibengkok core from a geothermal system in West Java, Indonesia provided an excellent opportunity to study geometric and petrologic characteristics of vein systems in volcanic rock. Vein minerals included chlorite, calcite, quartz, zeolites and sulphides. To obtain geometric data on the veins, we employed a neural net image processing technique to analyze high-resolution digital photography of the veins. We trained a neural net processor to map the extent of the vein using RGB pixel training classes. The resulting classification image was then converted to a binary image file and processed through a MatLab program that we designed to calculate vein geometric statistics, including aperture and roughness. We also performed detailed petrographic and microscopic geometric analysis on the veins to determine the history of mineralization and fracturing. We found that multi-phase mineralization due to chemical dissolution and re-precipitation as well as mechanical fracturing was a common feature in many of the veins and that it had a significant role for interpreting vein tortuosity and history of permeability. We used our micro- and macro-scale observations to construct four hypothetical permeability models that compliment the numerical and laboratory modeled data reported by Ebel and Brown. In each model, permeability changes, and in most cases fluctuates, differently over time as the tortuosity and aperture of

Preventing Deep Vein Thrombosis

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... Physicians Contact Us My ACOG ACOG Departments Donate Shop Career Connection Home Clinical Guidance & Publications Practice Management ... skin. A clot also can form if blood flow is too slow the lining of a vein ...

Finger Vein Recognition Based on Local Directional Code

Science.gov (United States)

Meng, Xianjing; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

2012-01-01

Finger vein patterns are considered as one of the most promising biometric authentication methods for its security and convenience. Most of the current available finger vein recognition methods utilize features from a segmented blood vessel network. As an improperly segmented network may degrade the recognition accuracy, binary pattern based methods are proposed, such as Local Binary Pattern (LBP), Local Derivative Pattern (LDP) and Local Line Binary Pattern (LLBP). However, the rich directional information hidden in the finger vein pattern has not been fully exploited by the existing local patterns. Inspired by the Webber Local Descriptor (WLD), this paper represents a new direction based local descriptor called Local Directional Code (LDC) and applies it to finger vein recognition. In LDC, the local gradient orientation information is coded as an octonary decimal number. Experimental results show that the proposed method using LDC achieves better performance than methods using LLBP. PMID:23202194

Finger Vein Recognition Based on Local Directional Code

Directory of Open Access Journals (Sweden)

Rongyang Xiao

2012-11-01

Full Text Available Finger vein patterns are considered as one of the most promising biometric authentication methods for its security and convenience. Most of the current available finger vein recognition methods utilize features from a segmented blood vessel network. As an improperly segmented network may degrade the recognition accuracy, binary pattern based methods are proposed, such as Local Binary Pattern (LBP, Local Derivative Pattern (LDP and Local Line Binary Pattern (LLBP. However, the rich directional information hidden in the finger vein pattern has not been fully exploited by the existing local patterns. Inspired by the Webber Local Descriptor (WLD, this paper represents a new direction based local descriptor called Local Directional Code (LDC and applies it to finger vein recognition. In LDC, the local gradient orientation information is coded as an octonary decimal number. Experimental results show that the proposed method using LDC achieves better performance than methods using LLBP.

Palm Vein Verification Using Multiple Features and Locality Preserving Projections

Directory of Open Access Journals (Sweden)

Ali Mohsin Al-juboori

2014-01-01

Full Text Available Biometrics is defined as identifying people by their physiological characteristic, such as iris pattern, fingerprint, and face, or by some aspects of their behavior, such as voice, signature, and gesture. Considerable attention has been drawn on these issues during the last several decades. And many biometric systems for commercial applications have been successfully developed. Recently, the vein pattern biometric becomes increasingly attractive for its uniqueness, stability, and noninvasiveness. A vein pattern is the physical distribution structure of the blood vessels underneath a person’s skin. The palm vein pattern is very ganglion and it shows a huge number of vessels. The attitude of the palm vein vessels stays in the same location for the whole life and its pattern is definitely unique. In our work, the matching filter method is proposed for the palm vein image enhancement. New palm vein features extraction methods, global feature extracted based on wavelet coefficients and locality preserving projections (WLPP, and local feature based on local binary pattern variance and locality preserving projections (LBPV_LPP have been proposed. Finally, the nearest neighbour matching method has been proposed that verified the test palm vein images. The experimental result shows that the EER to the proposed method is 0.1378%.

Portal vein branching order helps in the recognition of anomalous right-sided round ligament: common features and variations in portal vein anatomy.

Science.gov (United States)

Yamashita, Rikiya; Yamaoka, Toshihide; Nishitai, Ryuta; Isoda, Hiroyoshi; Taura, Kojiro; Arizono, Shigeki; Furuta, Akihiro; Ohno, Tsuyoshi; Ono, Ayako; Togashi, Kaori

2017-07-01

This study aimed to evaluate the common features and variations of portal vein anatomy in right-sided round ligament (RSRL), which can help propose a method to detect and diagnose this anomaly. In this retrospective study of 14 patients with RSRL, the branching order of the portal tree was analyzed, with special focus on the relationship between the dorsal branch of the right anterior segmental portal vein (P A-D ) and the lateral segmental portal vein (P LL ), to determine the common features. The configuration of the portal vein from the main portal trunk to the right umbilical portion (RUP), the inclination of the RUP, and the number and thickness of the ramifications branching from the right anterior segmental portal vein (P A ) were evaluated for variations. In all subjects, the diverging point of the P A-D was constantly distal to that of the P LL . The portal vein configuration was I- and Z-shaped in nine and five subjects, respectively. The RUP was tilted to the right in all subjects. In Z-shaped subjects, the portal trunk between the branching point of the right posterior segmental portal vein and that of the P LL was tilted to the left in one subject and was almost parallel to the vertical plane in four subjects. Multiple ramifications were radially distributed from the P A in eight subjects, whereas one predominant P A-D branched from the P A in six subjects. Based on the diverging points of the P A-D and P LL , we proposed a three-step method for the detection and diagnosis of RSRL.

A Tight Spot After Pulmonary Vein Catheter Ablation

NARCIS (Netherlands)

Amir, Rabia; Yeh, Lu; Montealegre-Gallegos, Mario; Saraf, Rabya; Matyal, Robina; Mahmood, Feroze

2016-01-01

A 52-YEAR-OLD woman with a history of embolic stroke due to paroxysmal atrial fibrillation was referred to the authors’ institution for epicardial surgical pulmonary vein isolation with left atrial appendage resection. The patient had 2 previous failed pulmonary vein catheter ablations. Dense

CO2-DSA in lower extremity veins: a clinical application

International Nuclear Information System (INIS)

Guo Jinhe; Teng Gaojun; Zhu Guangyu; Liu Zhensheng; Li Guozhao; Ding Huijuan; Shen Zhiping; He Shicheng; Deng Gang; Fang Wen

2005-01-01

Objective: To explore the feasibility and usefulness of carbon dioxide digital subtraction angiography (CO 2 -DSA) in deep veins of lower extremity via the dorsal is pedis vein. Methods: CO 2 -DSA in lower extremity veins was performed in 15 patients (15 limbs affected, male 9, female 6) by injection of CO 2 via the dorsal is pedis vein. Among them, 8 patients were suspected with deep venous thrombosis (DVT), 6 patients with saphena magna dilation, and 1 patient with a follow-up after thrombolysis due to DVT. Results: Excellent image was obtained in 12 cases, which showed branches of the venous system clearly, as well as the details of DVT. Good image was obtained in 2 cases. Technical failure was encountered in one patient due to inaccessible puncture veins. Mild discomfort (transient pain at the percutaneous site) during the procedure was demonstrated in 11 patients. There was no severe side effects or complications in this series. Conclusion: CO 2 -DSA in lower extremity veins is feasible and safe, the preliminary result is satisfactory. (authors)

Updated cannulation technique for tissue plasminogen activator injection into peripapillary retinal vein for central retinal vein occlusion.

Science.gov (United States)

van Overdam, Koen A; Missotten, Tom; Spielberg, Leigh H

2015-12-01

To update the surgical technique in which a vitrectomy is performed and a retinal branch vein is cannulated and infused with recombinant tissue plasminogen activator (RTPA) to treat central retinal vein occlusion (CRVO) in patients who present with very low visual acuity (VA). Twelve consecutive patients (12 eyes) with CRVO and low VA (logMAR >1.00) at presentation were treated using this method. Cannulation of a peripapillary retinal vein and stable injection of RTPA was successfully performed without surgery-related complications in all 12 eyes. At 12 months after surgery, 8 of the 12 patients (67%) experienced at least one line of improvement in best corrected visual acuity; 6 of the 12 (50%) improved ≥5 lines and 2 (17%) improved ≥8 lines. After additional grid laser and/or subconjunctival or intravitreal corticosteroids, the mean decrease in central foveal thickness was 260 μm, and the mean total macular volume decreased from 12.10 mm(3) to 9.24 mm(3) . Four patients received panretinal photocoagulation to treat either iris neovascularization (n = 2) or neovascularization of the retina and/or disc (n = 2). Administration of RTPA via a peripapillary vein using this updated technique provides an alternative or additional treatment option for patients with very low VA after CRVO. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

CT of portal vein tumor thrombosis. Usefulness of dynamic CT

Energy Technology Data Exchange (ETDEWEB)

Takemoto, Kazumasa; Inoue, Yuichi; Tanaka, Masahiro; Nemoto, Yutaka; Nakamura, Kenji [Osaka City Univ. (Japan). Faculty of Medicine

1983-08-01

We evaluated CT findings of portal vein tumor thrombosis in 16 hepatomas by plain, contrast and dynamic CT. Plain and contrast CT findings were an enlargement of the portal vein (81%), intraluminal low density area (63%). Dynamic CT enhanced the diagnostic capability of the tumor thrombus as a relatively low density area because of the marked enhancement of the portal vein. In addition, dynamic CT newly demonstrated hyperdense peripheral ring (35%) and arterio portal shunt (35%). It is advisable to select the scan level to include the portal vein when dynamic CT is performed in the patient of hepatocellular carcinoma.

Genetic Aspects of Gold Mineralization at Some Occurrences in the Eastern Desert of Egypt

Science.gov (United States)

Abd El Monsef, M.; Slobodník, M.; Salem, I. A.

2012-04-01

The Eastern Desert of Egypt is well known as a gold-mining area since ancient times, there're more than 95 gold deposits and occurrences spread the whole area covered by the basement rocks of Precambrian age. The basement rocks of the Eastern Desert of Egypt constitute the Nubian Shield that has formed a continuous part of the Arabian-Nubian Shield before the opening of Red Sea (Oligocene-Early Miocene). Commonly, the system of gold-bearing quartz veins in the Eastern Desert is clearly structural controlled related to brittle-ductile shear zones that mostly developed during late deformational stages of the evolution history for basement rocks in the Eastern Desert. This running study principally aims to contribute the mineral resource potential of the gold deposits in Egypt, so particularly Fatira, Gidami and Atalla occurrences have been involved into a comprehensive study based on field, structural, mineralogical, geochemical and genetic investigations. It is intended to better understanding for the characteristics, distribution controls, conditions and age of mineralization in relation to the age of the hosting rocks intrusion to find if there're genetic links between the gold mineralization and the evolution of the host intrusive complex. Several authors suggested that the gold mineralization was related to the intrusion of the (postorogenic) Younger granites. Other authors interpret these deposits as products of hydrothermal activity induced either by metamorphism or cooling effects of early Paleozoic magmatism or as combined metamorphic/magmatic episodes. The prime focus will be directed to the ore itself and the associated hydrothermal alteration zones based on detailed maps and well-distributed samples network and geochemical anomalies distribution. The laboratory studies included microscopic examination (reflecting and transmitting microscopy) to allow for determination of the hosting rocks types and mineralogical changes related to the gold mineralization

Palm vein recognition based on directional empirical mode decomposition

Science.gov (United States)

Lee, Jen-Chun; Chang, Chien-Ping; Chen, Wei-Kuei

2014-04-01

Directional empirical mode decomposition (DEMD) has recently been proposed to make empirical mode decomposition suitable for the processing of texture analysis. Using DEMD, samples are decomposed into a series of images, referred to as two-dimensional intrinsic mode functions (2-D IMFs), from finer to large scale. A DEMD-based 2 linear discriminant analysis (LDA) for palm vein recognition is proposed. The proposed method progresses through three steps: (i) a set of 2-D IMF features of various scale and orientation are extracted using DEMD, (ii) the 2LDA method is then applied to reduce the dimensionality of the feature space in both the row and column directions, and (iii) the nearest neighbor classifier is used for classification. We also propose two strategies for using the set of 2-D IMF features: ensemble DEMD vein representation (EDVR) and multichannel DEMD vein representation (MDVR). In experiments using palm vein databases, the proposed MDVR-based 2LDA method achieved recognition accuracy of 99.73%, thereby demonstrating its feasibility for palm vein recognition.

[Cockett's syndrome, May-Thurner syndrome, or iliac vein compression syndrome].

Science.gov (United States)

Gil Martín, A R; Carreras Aja, M; Arrieta Ardieta, I; Labayen Azparren, I

2014-01-01

Iliac vein compression syndrome (also known as May-Thurner syndrome or Cockett's syndrome) is a rare clinical entity in which the left common iliac vein is compressed when it passes between the right common iliac artery and the spine. The sustained compression and trauma caused by the pulsatile force of the artery on the vein damage the intima and lead to the formation of membranes or bands in the vascular lumen that hinder or obstruct the flow of blood in the vein, favoring thrombus formation. The current treatment strategy of choice is endovascular vein patch angioplasty and stenting with the aim of improving the caliber of the lumen and enabling normal venous drainage. We present two cases of May-Thurner syndrome and review the clinical and CT findings. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

Gold 100: proceedings of the international conference on gold. V. 2

International Nuclear Information System (INIS)

Fivaz, C.E.; King, R.P.

1986-01-01

The proceedings of Gold 100 have been published in three separate volumes. The first deals with the mining of gold, the second with the extractive metallurgy of gold, and the third with industrial uses of gold. In this second volume, the papers on extractive metallurgy presented at the Conference reflect most of the problems that are currently of significant technical interest to the industry. This volume is divided in six main parts covering plant design, carbon-in-pulp technology, refractory gold, new technology, grinding and concentration, and leaching. The part on new technology includes papers on x-ray fluorescence analyzers, Moessbauer spectroscopy and leaching processes for uranium, while the part on grinding and concentration includes papers on nuclear and radiotracer techniques for the recovery of gold as well as various flotation parameters in the flotation behaviour of gold and uranium

Pattern of venous collateral development after splenic vein occlusion in an extended Whipple procedure : comparison with collateral vein pattern in cases of sinistral portal hypertension.

Science.gov (United States)

Strasberg, Steven M; Bhalla, Sanjeev; Sanchez, Luis A; Linehan, David C

2011-11-01

The risks of developing sinistral portal hypertension as a result of occlusion of the splenic vein close to its termination during a Whipple procedure are unclear. Our purpose was to compare the pattern of venous collateral development after splenic vein ligation in an extended Whipple procedure with the pattern of collateral development in cases of sinistral portal hypertension. Five patients underwent an extended Whipple procedure in which the splenic vein was divided and not reconstructed. Six to eight months later detailed mapping of venous return from the spleen was determined by contrast-enhanced multidetector computed tomography or in one case by 3D contrast-enhanced MRI. Spleen size and length of residual patent splenic vein were also measured. The literature on sinistral portal hypertension was evaluated to ascertain whether the venous collateral pattern in cases of left-sided portal hypertension was similar to the pattern that developed when the splenic vein was ligated at its termination in the Whipple procedure. A length of splenic vein remained patent in all five patients, measuring 4.5 to 11.5 cm from the spleen. Splenomegaly did not develop. Blood returned from the spleen by multiple collaterals including collaterals in the omentum and mesocolon. These types of collaterals do not develop in sinistral portal hypertension, nor is residual patent splenic vein seen. Ligation of the splenic vein close to its termination in five patients resulted in a pattern of venous return different from patients that have developed left-sided portal hypertension.

A rare case of anastomosis between the external and internal jugular veins.

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Karapantzos, Ilias; Zarogoulidis, Paul; Charalampidis, Charalampos; Karapantzou, Chrysanthi; Kioumis, Ioannis; Tsakiridis, Kosmas; Mpakas, Andrew; Sachpekidis, Nikolaos; Organtzis, John; Porpodis, Konstantinos; Zarogoulidis, Konstantinos; Pitsiou, Georgia; Zissimopoulos, Athanasios; Kosmidis, Christoforos; Fouka, Evagelia; Demetriou, Theodoros

2016-01-01

Jugular veins bring deoxygenated blood from the head back to the heart. There are two sets of external and internal veins. The external jugular vein receives the greater part of the blood from the cranium and the deep parts of the face. It commences from the substance of the parotid gland and runs down the neck at the posterior border of sternocleidomastoideus and ends in the subclavian vein in front of the scalenus anterior. The external jugular vein is covered by the platysma and its upper half runs parallel with the great auricular nerve. There is also another minor jugular vein, the anterior, draining the submaxillary region. In our patient, we recognized a shunt between the external and internal jugular veins. It appeared in the middle of the veins, between the pair of valves, which are placed ~2.5 cm above the termination of the vessel. The anastomosis was fully functional, and there was no problem in the blood pressure of the patient. Moreover, the shunt was not associated with any systemic disease.

Quartz-molybdenite veins in the Priestly Lake granodiorite, north-central Maine

Science.gov (United States)

Ayuso, Robert A.; Shank, Stephen G.

1983-01-01

Quartz-molybdenite veins up to 15 cm in width occur in fine to medium-grained porphyritic biotite-hornblende granodiorite at Priestly Lake north-central Maine. An area of about 150 m x 150 m contains quartz-molybdenite veins; a larger area is characterized by barren quartz veins. Quartz-molybdenite veins are concentrated within the most felsic variants of the intrusion as suggested by lower mafic mineral contents. The pluton has a narrow range in SiO2 (67-70 wt.%), major oxides, and in trace-element compositions. Molybdenite occurs as coarse grained clusters in pockets within the quartz veins, and fills fractures in the quartz veins and host rocks. Disseminated molybdenite in the granodiorite is relatively rare and occurs only in the area characterized by a high density of quartz veins (up to 50 veins per square meter). Alteration envelopes along the quartz veins are very thin or absent, although in some areas the granodiorite appears to be selectively and pervasively altered. Sericite, chlorite, epidote, calcite, pyrite, and quartz are concentrated near the quartz-molybdenite veins. Many of the field and geochemical characteristics of the Priestly Lake pluton are unlike those of major molybdenum-producing areas (Climax, Henderson, Urad). For example, the area of alteration seems to be of limited extent, the host rock is not intensely altered hydrothermally at the surface, the density of fractures is rather low in the mineralized area, and the amount of disseminated molybdenite appears to be small. However, the Priestly Lake pluton may be a small fraction of a concealed batholith as suggested by geophysical data. It is conceivable that the type of mineralization at the surface might be the expression of more extensive molybdenite mineralization at depth. The quartz-molybdenite veins in the Priestly Lake pluton are significant because they indicate that potential molybdenum sources for producing mineralized granites were available at depth. Future studies should be

A new design concept for knitted external vein-graft support mesh.

Science.gov (United States)

Singh, Charanpreet; Wang, Xungai

2015-08-01

Autologous vein-graft failure significantly limits the long-term efficacy of coronary artery bypass procedures. The major cause behind this complication is biomechanical mismatch between the vein and coronary artery. The implanted vein experiences a sudden increase (10-12 fold) in luminal pressures. The resulting vein over-distension or 'ballooning' initiates wall thickening phenomenon and ultimate occlusion. Therefore, a primary goal in improving the longevity of a coronary bypass procedure is to inhibit vein over-distension using mechanical constriction. The idea of using an external vein-graft support mesh has demonstrated sustained benefits and wide acceptance in experimental studies. Nitinol based knitted structures have offered more promising mechanical features than other mesh designs owing to their unique loosely looped construction. However, the conventional plain knit construction still exhibits limitations (radial compliance, deployment ease, flexibility, and bending stresses) which limit this design from proving its real clinical advantage. The new knitted mesh design presented in this study is based on the concept of composite knitting utilising high modulus (nitinol and polyester) and low modulus (polyurethane) material components. The experimental comparison of the new design with a plain knit design demonstrated significant improvement in biomechanical (compliance, flexibility, extensibility, viscoelasticity) and procedural (deployment limit) parameters. The results are indicative of the promising role of new mesh in restoring the lost compliance and pulsatility of vein-graft at high arterial pressures. This way it can assist in controlled vein-graft remodelling and stepwise restoration of vein mechanical homoeostasis. Also, improvement in deployment limit parameter offers more flexibility for a surgeon to use a wide range of vein diameters, which may otherwise be rendered unusable for a plain knit mesh. Copyright © 2015 Elsevier Ltd. All rights

Paper Money but a Gold Debt. Italy in the Gold Standard

OpenAIRE

Giuseppe Tattara; or consequences)

2002-01-01

During the 52 years between the Unification of the Kingdom of Italy and World War 1, the lira was legally convertible into metal for a limited period of time. Although not formally committed to gold, the lira exchange towards the gold standard countries proved remarkably stable, \\223shadowing\\224 gold. It is widely claimed that being one of the successful members of the gold standard circle entailed a number of advantages. If the lira was closely linked to gold, suggesting that there was only...

Anatomical variations of the right hepatic veins and their relevance to surgery.

Science.gov (United States)

Hribernik, Marija; de Cecchis, Lucio; Trotovsek, Blaz; Gadzijev, Eldar M; Ravnik, Dean

2003-01-01

In a morphological study of the right hepatic veins anatomical characteristics of surgical importance were looked for. 110 cadaveric human livers were prepared by the corrosion casts method. The confluence patterns of the superior right hepatic vein, the hepatocaval confluence, the accessory right hepatic veins and the anastomoses between hepatic veins in the right hemiliver were examined. Four types of the superior right hepatic vein, based on the length of its trunk and the confluence pattern of its main tributaries were determined and their frequency was calculated. Type I was found in 20%, type II in 40%, type III in 25% and type IV in 15%. Accessory right hepatic veins with a minimal caliber of 0.4 cm, which were always present in type IV, were also found in other types, all together in 27% of the casts. The tributary-free part of the superior right hepatic vein at hepatocaval confluence was longer than 1 cm in 77%. In the right hemiliver 109 anastomoses were found in 29/110 liver casts. Knowing the characteristics of different superior right hepatic vein types and of the accessory right hepatic veins may be useful in segment-oriented liver resections and in right side living donor resections.

Inferior vena cava filter insertion through the popliteal vein: enabling the percutaneous endovenous intervention of deep vein thrombosis with a single venous access approach in a single session

Science.gov (United States)

Kim, Hyoung Ook; Kim, Jae Kyu; Park, Jin Gyoon; Yim, Nam Yeol; Kang, Yang Jun; Jung, Hye Doo

2016-01-01

PURPOSE We aimed to evaluate the efficiency of placing an inferior vena cava (IVC) filter through the same popliteal vein access site used for percutaneous endovenous intervention in patients with extensive lower extremity deep vein thrombosis. METHODS This retrospective study included 21 patients who underwent IVC filter insertion through the popliteal vein over a three-year period. Patient medical records were reviewed for the location of the deep vein thrombosis, result of filter removal, and total number of endovascular procedures needed for filter insertion and recanalization of the lower extremity venous system. Follow-up lower extremity computed tomography (CT) venography was also reviewed in each patient to assess the degree of filter tilt in the IVC. RESULTS All patients had extensive lower extremity deep vein thrombosis involving the iliac vein and/or femoral vein. Seventeen patients showed deep vein thrombosis of the calf veins. In all patients, IVC filter insertion and the recanalization procedure were performed during a single procedure through the single popliteal vein access site. In the 17 patients undergoing follow-up CT, the mean tilt angle of the filter was 7.14°±4.48° in the coronal plane and 8.77°±5.49° in the sagittal plane. Filter retrieval was successful in 16 of 17 patients (94.1%) in whom filter retrieval was attempted. CONCLUSION Transpopliteal IVC filter insertion is an efficient technique that results in low rates of significant filter tilt and enables a single session procedure using a single venous access site for filter insertion and percutaneous endovenous intervention. PMID:27559713

Formation of quartz veins by local dissolution and transport of silica

Energy Technology Data Exchange (ETDEWEB)

Wangen, Magnus; Munz, Ingrid Anne

2004-08-01

A simple model is proposed for the (often) thick quartz veins observed in the Modum Complex in Southern Norway. The formation of these veins cannot easily be explained by silica imported by hot ascending fluids. The proposed model has dissolution in the host rock adjacent to the veins as the source for silica. The suggested process for vein formation is represented by a reaction-diffusion equation, and the process is studied in terms of a Damkoehler number. Estimates for the growth rate of quartz cement are derived. The estimates for the growth rate can be used to constrain poorly known parameters of the vein formation process, like for instance, the degree of supersaturation in the host rock. (Author)

Primary extraskeletal mesenchymal chondrosarcoma arising from the iliac vein

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Hua Zhang

2017-10-01

Full Text Available The iliac vein is an extremely rare site for mesenchymal chondrosarcoma, and patients with primary extraskeletal mesenchymal chondrosarcoma arising from a vein always suffer a very poor prognosis. We report a case of a 45-year-old female who presented with a 5-month history of left leg edema in 2015. Contrast-enhanced computed tomography showed a large mass in the left iliac vein with scattered calcifications. Wide-margin resection was performed, and histopathologic and immunohistochemical analyses confirmed the presence of intraluminal mesenchymal chondrosarcoma with local invasion out of the vein wall. Due to poor patient compliance, postoperative neoadjuvant chemotherapy and radiotherapy were not started, and a bone scan performed 16 weeks postoperatively showed multiple bone metastases. The patient died on the twenty-fourth postoperative week.

Iliac Vein Compression Syndrome due to Bladder Distention Caused by Urethral Calculi

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Akiko Ikegami

2015-01-01

Full Text Available We report a rare case of iliac vein compression syndrome caused by urethral calculus. A 71-year-old man had a history of urethral stenosis. He complained of bilateral leg edema and dysuria for 1 week. Physical examination revealed bilateral distention of the superficial epigastric veins, so obstruction of both common iliac veins or the inferior vena cava was suspected. Plain abdominal computed tomography showed a calculus in the pendulous urethra, distention of the bladder (as well as the right renal pelvis and ureter, and compression of the bilateral common iliac veins by the distended bladder. Iliac vein compression syndrome was diagnosed. Bilateral iliac vein compression due to bladder distention (secondary to neurogenic bladder, benign prostatic hyperplasia, or urethral calculus as in this case is an infrequent cause of acute bilateral leg edema. Detecting distention of the superficial epigastric veins provides a clue for diagnosis of this syndrome.

The study of multi-detector CT on the grouping and measuring of the hepatic veins

International Nuclear Information System (INIS)

Wang Xianliang; Dong Guang; Geng Hai; Wang Wengang; Li Linkun; Gao Wei; Wang Rongfang

2007-01-01

Objective: To study the three-dimensional topography of the hepatic vein (HV), the inferior vena cava(IVC) and the inferior right hepatic vein(IRHV) in the retrohepatic and pre-IVC tunnel in human beings, and to provide an anatomic reference for liver surgery. Methods: One hundred and ten volunteers underwent CT scanning at 60 to 75 s after injection of contrast medium, and their HV, IVC and IRHV were reconstructed into MPR and 3D-MIP images. The hepatic veins were grouped according to the way by which the hepatic vein enters IVC. The angle between the right hepatic vein and the middle hepatic vein or the trunk of hepatic vein was measured, and the width from right hepatic vein to middle hepatic vein or to the trunk of hepatic vein on IVC was recorded. The frequency of IRHV was observed, and the length of the tunnel was measured. Results: Among the 110 volunteers, there were 6 cases (5.45%) with three hepatic veins respectively entering IVC, 98 cases (89.10%) with right hepatic vein and a common trunk of the middle hepatic vein and the left hepatic vein entering IVC, and 6 cases (5.45%) with left hepatic vein and a common trunk of the right hepatic vein and the middle hepatic vein entering IVC. The mean value of the angles between the right hepatic vein and the middle hepatic vein or the mink of hepatic vein was (55 ± 18) degree. The width from the right hepatic vein to the middle hepatic vein or to the trunk of hepatic vein was (21 ± 7)mm. The IRHV was observed in 30 cases(27.27%). The mean value of the tunnel length was (53 ± 11) mm. Conclusion: The parameters of the retrohepatic and pre-IVC tunnel in human beings can be measured accurately by the imaging of MPR, which can provide an anatomic reference for the liver surgery. (authors)

GOLD IS EARNED FROM THE PRODUCTION OF THAI GOLD LEAF

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Dirk Bax

2010-06-01

Full Text Available Thai people like to cover sacred objects or things dear to them with gold leaf.. Statues of Buddha are sometimes covered with so many layers of gold leaf that they become formless figures, that can hardly be recognized. Portraits of beloved ancestors, statues of elephants and grave tombs are often covered with gold leaf. If one considers the number of Thai people and the popularity of the habit, the amount of gold involved could be considerable.

Right ovarian vein drainage variant: Is there a relationship with pelvic varices?

International Nuclear Information System (INIS)

Koc, Zafer; Ulusan, Serife; Oguzkurt, Levent

2006-01-01

Objective: To correlate right ovarian vein (ROV) variations that drain into the right renal vein (RRV) with the presence of pelvic varices. Materials and methods: Routine abdominal multidetector-row computed tomography scans of 324 women were analyzed for the presence and type of ROV variations in this retrospective study. The subjects were divided into 2 groups: those with ROV variations and those without such variations. The diameters of the subjects' ROV, left ovarian vein (LOV), and parauterine veins were measured. Pelvic varices and the presence and degree of ovarian vein reflux were noted and compared between the 2 groups. The χ 2 -test and the Pearson correlation test were used for statistical analysis. Results: Thirty-two (9.9%) of 324 women studied exhibited ROV variant that drained into the right renal vein, and the remaining subjects (90.1%) exhibited a normal pattern of ROV drainage that flowed directly into the inferior vena cava. Pelvic varices were identified in 59 (18%) of the subjects. Reflux was not observed in any patient without pelvic varices. Fifty-seven of 59 women exhibited ovarian vein reflux. In 56 of those 57 individuals, reflux occurred only in the LOV, and in 1 subject, reflux was noted predominantly in the ROV. No significant relationship between the presence of an ROV that drained into the right renal vein and pelvic varices was noted. Conclusion: Although right-sided pelvic varices associated with right ovarian vein drainage variations are rare, anatomic variations of the right ovarian vein are not. This study did not find an association between the presence of right ovarian vein and pelvic varices

Right ovarian vein drainage variant: Is there a relationship with pelvic varices?

Energy Technology Data Exchange (ETDEWEB)

Koc, Zafer [Baskent Universitesi, Adana Hastanesi, Radyoloji Boeluemue, Serin Evler 39, Sok. No. 6 Yueregir, Adana (Turkey)]. E-mail: koczafer@gmail.com; Ulusan, Serife [Baskent Universitesi, Adana Hastanesi, Radyoloji Boeluemue, Serin Evler 39, Sok. No. 6 Yueregir, Adana (Turkey); Oguzkurt, Levent [Baskent Universitesi, Adana Hastanesi, Radyoloji Boeluemue, Serin Evler 39, Sok. No. 6 Yueregir, Adana (Turkey)

2006-09-15

Objective: To correlate right ovarian vein (ROV) variations that drain into the right renal vein (RRV) with the presence of pelvic varices. Materials and methods: Routine abdominal multidetector-row computed tomography scans of 324 women were analyzed for the presence and type of ROV variations in this retrospective study. The subjects were divided into 2 groups: those with ROV variations and those without such variations. The diameters of the subjects' ROV, left ovarian vein (LOV), and parauterine veins were measured. Pelvic varices and the presence and degree of ovarian vein reflux were noted and compared between the 2 groups. The {chi}{sup 2}-test and the Pearson correlation test were used for statistical analysis. Results: Thirty-two (9.9%) of 324 women studied exhibited ROV variant that drained into the right renal vein, and the remaining subjects (90.1%) exhibited a normal pattern of ROV drainage that flowed directly into the inferior vena cava. Pelvic varices were identified in 59 (18%) of the subjects. Reflux was not observed in any patient without pelvic varices. Fifty-seven of 59 women exhibited ovarian vein reflux. In 56 of those 57 individuals, reflux occurred only in the LOV, and in 1 subject, reflux was noted predominantly in the ROV. No significant relationship between the presence of an ROV that drained into the right renal vein and pelvic varices was noted. Conclusion: Although right-sided pelvic varices associated with right ovarian vein drainage variations are rare, anatomic variations of the right ovarian vein are not. This study did not find an association between the presence of right ovarian vein and pelvic varices.

Acute paraumbilical vein recanalization: an unusual complication of acute pancreatitis

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R J Foster

2015-04-01

Full Text Available Acute pancreatitis is associated with a number of well-known complications and imaging findings. Spontaneous recanalization of the paraumbilical veins as a consequence of pancreatitis in a patient with an otherwise normal liver is, however, a rare entity. This case report depicts this unusual complication as a consequence of gallstone pancreatitis in a patient with a non-cirrhotic liver and no clinical or radiological evidence of portal hypertension. There was recanalization of the paraumbilical veins followed by thrombosis, which is believed to have propagated in a retrograde fashion into distal branches of the otherwise patent portal vein. A literature search for similar cases such as this has yielded no results. Although rare, clinicians and radiologists alike need to be aware of this finding. This case discussion highlights the embryology and anatomy of the paraumbilical veins, as well as discusses the management of paraumbilical and portal vein thrombosis.

Finger Vein Recognition Using Optimal Partitioning Uniform Rotation Invariant LBP Descriptor

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Bang Chao Liu

2016-01-01

Full Text Available As a promising biometric system, finger vein identification has been studied widely and many relevant researches have been proposed. However, it is hard to extract a satisfied finger vein pattern due to the various vein thickness, illumination, low contrast region, and noise existing. And most of the feature extraction algorithms rely on high-quality finger vein database and take a long time for a large dimensional feature vector. In this paper, we proposed two block selection methods which are based on the estimate of the amount of information in each block and the contribution of block location by looking at recognition rate of each block position to reduce feature extraction time and matching time. The specific approach is to find out some local finger vein areas with low-quality and noise, which will be useless for feature description. Local binary pattern (LBP descriptors are proposed to extract the finger vein pattern feature. Two finger vein databases are taken to test our algorithm performance. Experimental results show that proposed block selection algorithms can reduce the feature vector dimensionality in a large extent.

Sliding Window-Based Region of Interest Extraction for Finger Vein Images

Science.gov (United States)

Yang, Lu; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

2013-01-01

Region of Interest (ROI) extraction is a crucial step in an automatic finger vein recognition system. The aim of ROI extraction is to decide which part of the image is suitable for finger vein feature extraction. This paper proposes a finger vein ROI extraction method which is robust to finger displacement and rotation. First, we determine the middle line of the finger, which will be used to correct the image skew. Then, a sliding window is used to detect the phalangeal joints and further to ascertain the height of ROI. Last, for the corrective image with certain height, we will obtain the ROI by using the internal tangents of finger edges as the left and right boundary. The experimental results show that the proposed method can extract ROI more accurately and effectively compared with other methods, and thus improve the performance of finger vein identification system. Besides, to acquire the high quality finger vein image during the capture process, we propose eight criteria for finger vein capture from different aspects and these criteria should be helpful to some extent for finger vein capture. PMID:23507824

Veias do sistema porta-hepático em gansos domésticos Veins from hepatic portal vein system in domestic geese

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Tatiana C. Santos

2009-04-01

Full Text Available A distribuição intraparenquimal das veias porta-hepáticas foi estudada em 30 gansos domésticos. Latex Neoprene corado foi injetado pela veia isquiática e os animais forma fixados por imersão e injeção intramuscular com formol a 10% e dissecados. O fígado esteve composto por um grande lobo hepático direito e por um lobo hepático esquerdo menor, os quais estiveram conectados por uma ponte de parênquima. O lobo direito do fígado teve exclusivamente vasos do sistema porta-hepático formados pela distribuição intraparenquimal da veia porta-hepática direita, enquanto que no lobo esquerdo estes originaram-se da veia porta-hepática direita e de pequenas veias porta-hepáticas esquerdas. A veia porta-hepática direita emitiu o ramo caudal direito, que emitiu um pequeno ramo caudolateral direito e um grande ramo caudomedial direito. Cranialmente esta veia emitiu os ramos craniais direito e ramos lateral direito. A porção transversa da veia porta-hepática direita cruzou para o lobo hepático esquerdo, emitindo de 1 a 6 pequenos ramos craniais e caudais para a região média do fígado. No lobo esquerdo, o ramo esquerdo da veia porta-hepática direita emitiu o ramo cranial esquerdo, o ramo lateral esquerdo e o ramo medial. De 1 a 6 veias porta-hepáticas esquerdas foram identificadas desembocando ou no ramo esquerdo da veia porta-hepática direita ou em sua porção transversa, oriundos do ventrículo gástrico e do pró-ventrículo. Em 40% dos gansos uma veia porta-hepática própria oriunda da confluência de vasos venosos da face esquerda do ventrículo distribuiu-se na extremidade caudal do lobo esquerdo isoladamente.The intraparenchymal distribution of the hepatic portal veins in 30 domestic geese were studied. Stained Neoprene latex was injected into the isquiatic vessels, and the animals were fixed in 10% formaldehyde by immersion and intramuscular injection. The liver of geese was composed of a large right and a smaller left

Arabidopsis thickvein mutation affects vein thickness and organ vascularization, and resides in a provascular cell-specific spermine synthase involved in vein definition and in polar auxin transport.

Science.gov (United States)

Clay, Nicole K; Nelson, Timothy

2005-06-01

Polar auxin transport has been implicated in the induction of vascular tissue and in the definition of vein positions. Leaves treated with chemical inhibitors of polar auxin transport exhibited vascular phenotypes that include increased vein thickness and vascularization. We describe a recessive mutant, thickvein (tkv), which develops thicker veins in leaves and in inflorescence stems. The increased vein thickness is attributable to an increased number of vascular cells. Mutant plants have smaller leaves and shorter inflorescence stems, and this reduction in organ size and height is accompanied by an increase in organ vascularization, which appears to be attributable to an increase in the recruitment of cells into veins. Furthermore, although floral development is normal, auxin transport in the inflorescence stem is significantly reduced in the mutant, suggesting that the defect in auxin transport is responsible for the vascular phenotypes. In the primary root, the veins appear morphologically normal, but root growth in the tkv mutant is hypersensitive to exogenous cytokinin. The tkv mutation was found to reside in the ACL5 gene, which encodes a spermine synthase and whose expression is specific to provascular cells. We propose that ACL5/TKV is involved in vein definition (defining the boundaries between veins and nonvein regions) and in polar auxin transport, and that polyamines are involved in this process.

Portal Vein Stenting for Portal Biliopathy with Jaundice

Energy Technology Data Exchange (ETDEWEB)

Hyun, Dongho, E-mail: mesentery@naver.com; Park, Kwang Bo, E-mail: kbjh.park@samsung.com [Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center (Korea, Republic of); Lim, Seong Joo [Konyang University, Department of Radiology, College of Medicine, Konyang University Hospital (Korea, Republic of); Hwang, Jin Ho [Hallym University Sacred Heart Hospital, Department of Radiology (Korea, Republic of); Sinn, Dong Hyun [Sungkyunkwan University School of Medicine, Department of Medicine, Samsung Medical Center (Korea, Republic of)

2016-04-15

Portal biliopathy refers to obstruction of the bile duct by dilated peri- or para-ductal collateral channels following the main portal vein occlusion from various causes. Surgical shunt operation or endoscopic treatment has been reported. Herein, we report a case of portal biliopathy that was successfully treated by interventional portal vein recanalization.

Near-infrared image formation and processing for the extraction of hand veins

Science.gov (United States)

Bouzida, Nabila; Hakim Bendada, Abdel; Maldague, Xavier P.

2010-10-01

The main objective of this work is to extract the hand vein network using a non-invasive technique in the near-infrared region (NIR). The visualization of the veins is based on a relevant feature of the blood in relation with certain wavelengths of the electromagnetic spectrum. In the present paper, we first introduce the image formation in the NIR spectral band. Then, the acquisition system will be presented as well as the method used for the image processing in order to extract the vein signature. Extractions of this pattern on the finger, on the wrist and on the dorsal hand are achieved after exposing the hand to an optical stimulation by reflection or transmission of light. We present meaningful results of the extracted vein pattern demonstrating the utility of the method for a clinical application like the diagnosis of vein disease, of primitive varicose vein and also for applications in vein biometrics.

Novel Percutaneous Radiofrequency Ablation of Portal Vein Tumor Thrombus: Safety and Feasibility

Energy Technology Data Exchange (ETDEWEB)

Mizandari, Malkhaz [High Technology Medical Center, Tbilisi State Medical University (Georgia); Ao, Guokun [The 309 Hospital of People' s Liberation Army, Department on Oncology (China); Zhang Yaojun; Feng Xi [Imperial College London, Department of Surgery and Cancer (United Kingdom); Shen Qiang [The First Minimally Invasive Department of Eastern Hepatobiliary Surgery Hospital (China); Chen Minshan [Cancer Centre of Sun Yat-Sen University, Department of Hepatobiliary Surgery (China); Lau, Wan Yee [Chinese University of Hong Kong, Department of Surgery, Faculty of Medicine (Hong Kong); Nicholls, Joanna; Jiao Long; Habib, Nagy, E-mail: nagy.habib@imperial.ac.uk [Imperial College London, Department of Surgery and Cancer (United Kingdom)

2013-02-15

We report our experience of the safety of partial recanalization of the portal vein using a novel endovascular radiofrequency (RF) catheter for portal vein tumor thrombosis. Six patients with liver cancer and tumor thrombus in the portal vein underwent percutaneous intravascular radiofrequency ablation (RFA) using an endovascular bipolar RF device. A 0.035-inch guidewire was introduced into a tributary of the portal vein and through which a 5G guide catheter was introduced into the main portal vein. After manipulation of the guide catheter over the thrombus under digital subtraction angiography, the endovascular RF device was inserted and activated around the thrombus. There were no observed technique specific complications, such as hemorrhage, vessel perforation, or infection. Post-RFA portography showed partial recanalization of portal vein. RFA of portal vein tumor thrombus in patients with hepatocellular carcinoma is technically feasible and warrants further investigation to assess efficacy compared with current recanalization techniques.

The color Doppler ultrasonography in in the diagnosis of deep vein thrombosis

International Nuclear Information System (INIS)

Ameneiro Perez, Santiago; Alvarez Sanchez, Jose A.; Rodriguez Villalonga, Luis; Borras Migues, Marisela; Quinnones Castro, Mayda

2004-01-01

The paper was aimed at evaluating the accuracy of color Doppler ultrasonography, a noninvasive method, in the diagnosis of deep vein thrombosis of the lower limbs, comparing it to the results of the cruel and costly diagnostic g olden rule , that is, phlebography. Methods: Color Doppler ultrasonography served to assess 102 patients clinically suspected of deep vein thrombosis of the lower limbs, taking into account the following criteria: vein compressibility, echographic images, color, Vein Doppler signal modulation after several maneuvers and distal compression. Sensitivity, specificity, positive and negative predictive values and diagnostic efficacy were estimated for each criteria, taking the phlebography as a reference. Results: Total or partial lack of vein compressibility combined with the vein flow evaluation is the ultrasonographic criterion that reveals higher degree of sensitivity, specificity and efficacy (0,98; 0,95 and 0,97 respectively. Color Doppler ultrasonography is a highly effective noninvasive diagnostic method that detects deep vein thrombosis in proximal areas of the lower limbs

Association between photosynthesis and contrasting features of minor veins in leaves of summer annuals loading phloem via symplastic versus apoplastic routes.

Science.gov (United States)

Muller, Onno; Cohu, Christopher M; Stewart, Jared J; Protheroe, Johanna A; Demmig-Adams, Barbara; Adams, William W

2014-09-01

Foliar vascular anatomy and photosynthesis were evaluated for a number of summer annual species that either load sugars into the phloem via a symplastic route (Cucumis sativus L. cv. Straight Eight; Cucurbita pepo L. cv. Italian Zucchini Romanesco; Citrullus lanatus L. cv. Faerie Hybrid; Cucurbita pepo L. cv. Autumn Gold) or an apoplastic route (Nicotiana tabacum L.; Solanum lycopersicum L. cv. Brandywine; Gossypium hirsutum L.; Helianthus annuus L. cv. Soraya), as well as winter annual apoplastic loaders (Spinacia oleracea L. cv. Giant Nobel; Arabidopsis thaliana (L.) Heynhold Col-0, Swedish and Italian ecotypes). For all summer annuals, minor vein cross-sectional xylem area and tracheid number as well as the ratio of phloem loading cells to phloem sieve elements, each when normalized for foliar vein density (VD), was correlated with photosynthesis. These links presumably reflect (1) the xylem's role in providing water to meet foliar transpirational demand supporting photosynthesis and (2) the importance of the driving force of phloem loading as well as the cross-sectional area for phloem sap flux to match foliar photosynthate production. While photosynthesis correlated with the product of VD and cross-sectional phloem cell area among symplastic loaders, photosynthesis correlated with the product of VD and phloem cell number per vein among summer annual apoplastic loaders. Phloem cell size has thus apparently been a target of selection among symplastic loaders (where loading depends on enzyme concentration within loading cells) versus phloem cell number among apoplastic loaders (where loading depends on membrane transporter numbers). © 2014 Scandinavian Plant Physiology Society.

Endovascular vein harvest: systemic carbon dioxide absorption.

Science.gov (United States)

Maslow, Andrew M; Schwartz, Carl S; Bert, Arthur; Hurlburt, Peter; Gough, Jeffrey; Stearns, Gary; Singh, Arun K

2006-06-01

Endovascular vein harvest (EDVH) requires CO(2) insufflation to expand the subcutaneous space, allowing visualization and dissection of the saphenous vein. The purpose of this study was to assess the extent of CO(2) absorption during EDVH. Prospective observational study. Single tertiary care hospital. Sixty patients (30 EDVH and 30 open-vein harvest) undergoing isolated coronary artery bypass graft surgery. Hemodynamic, procedural, and laboratory data were collected prior to (baseline), during, and at it the conclusion (final) of vein harvesting. Data were also collected during cardiopulmonary bypass (CPB). Data were compared by using t tests, analysis of variance, and correlation statistics when needed. There were significant increases in arterial CO(2) (PaCO(2), 35%) and decreases in pH (1.35%) during EDVH. These were associated with increases in heart rate, mean blood pressure, and cardiac output. Within the EDVH group, greater elevations (>10 mmHg) in PaCO2 were more likely during difficult harvest procedures, and these patients exhibited greater increase in heart rate. Elevated CO(2) persisted during CPB, requiring higher systemic gas flows and greater use of phenylephrine to maintain desired hemodynamics. EDVH was associated with systemic absorption of CO(2). Greater absorption was more likely in difficult procedures and was associated with greater hemodynamic changes requiring medical therapy.

Varicography in the preoperative evaluation of primary varicose veins

International Nuclear Information System (INIS)

Pinzani, A.; Paoli, G.; Gongolo, A.; Spreafico, G.

1989-01-01

Primary varicose veins in the lower limb are usually well evaluated by the surgeon, who avails himself of tornequet tests and Doppler US. However, the operation is often followed by failure or recurrence, or else it requires ugly skin dissection to eradicate an unforeseeably complicated varicose vein. The authors suggest that, whenever the surgeon considers the information obtained with tests and Doppler US inadequate for planning surgery, varicography be performed to get further morphological (and functional) data about the origin of varicose veins, which is of fundamental importance for an accurate surgical planning (crossectomy, stripping, ligation, sclerosis). Out of 100 varicographies consecutively carried out on patients in whom clinical examination was not conclusive, 62% allowed an already planned surgical approach to be changed. The figure rose to 100% in the case of unusual varicose veins. Such a results allowed the needs of both the surgeon (selectivity, effectiveness, radicality) and the patients (narrow scars, absence of relapse) to be respected. Furthermore, it has been pointed out that some vein segments are often only pathological, and they are to be adequately treated, while others can be undamaged, and they are to be preserved for both their function and an eventual by-pass surgery. Varicography is rapidly performed, without complication, and is well accepted by the patients. It is a fundamental help in the preoperative study of primary varicose veins, especially in case of unusual ones, whenever the surgeon is in the slightest diagnostic - and therefore surgical - doubt

Fluid inclusion study of the Witwatersrand gold-uranium ores

International Nuclear Information System (INIS)

Shepherd, T.J.

1977-01-01

Fluid inclusions, preserved in quartz pebbles of the uraniferous and auriferous Precambrian oligomictic conglomerates of the Witwatersrand Basin, provide a unique insight into the genesis of the ores. Using differences in inclusion characteristics in conjunction with intra- and inter-deformational textures for adjacent pebbles, a distinction is made between pre- and post-depositional inclusions. Excluding those related to subsequent brittle fracture, the former comprise five principal types; two of which are distinguished by the development of liquid carbon dioxide. Collectively they indicate a moderate to high pressure-temperature environment of vein quartz formation. Systematic variation in the relative abundance of these inclusion assemblages for different sections of the orefield demonstrates the importance of well-defined provenance areas or multiple entry points into the basins. A marked sympathetic relationship between uraniferous banket ores and the presence of vein quartz rich in liquid carbon dioxide inclusions, together with a corresponding antipathetic relationship for gold, strongly suggests separate sources for the metals. The temporal and spatial aspects of the association 'U-CO 2 ' also imply a uranium influx into the basin from discrete areas of the hinterland contemporaneous with the sediments. Post-depositional inclusions are subordinate and offer no support for the alternative epigenetic model and show only a later interaction of relatively cool circulating groundwaters. A discussion is given of the probable nature and origin of uranium in the source rocks and its mode of transportation. In conclusion, a proposal is made for the use of applied fluid inclusion research in the evaluation of and exploration for similar deposits. (author)

Clorities as geothermometer. La Bragada mine. Cordoba, Argentina

International Nuclear Information System (INIS)

Gonzalez, M.; Mas, G.

1998-01-01

Clorities have been proposed as geothermometer in geothermal and hydrothermal environments environments because they show a rather wide range of variation in their structural and chemical characteristics, regarded with the temperature of formation. Taking into account that this group of minerals constitute one of the main products of the hydrothermal alteration of the host rocks at the mesothermal gold deposit La Bragada. The optical and XRD study of these minerals have been performed in order to used them as geothermometer . The relation of this geothermometer with fluid inclusions thermometry in the same deposit has been analyzed in order to assess their use as a quick and simple mean for the thermometric characterization of an alteration zone. (author)

Palm-vein classification based on principal orientation features.

Directory of Open Access Journals (Sweden)

Yujia Zhou

Full Text Available Personal recognition using palm-vein patterns has emerged as a promising alternative for human recognition because of its uniqueness, stability, live body identification, flexibility, and difficulty to cheat. With the expanding application of palm-vein pattern recognition, the corresponding growth of the database has resulted in a long response time. To shorten the response time of identification, this paper proposes a simple and useful classification for palm-vein identification based on principal direction features. In the registration process, the Gaussian-Radon transform is adopted to extract the orientation matrix and then compute the principal direction of a palm-vein image based on the orientation matrix. The database can be classified into six bins based on the value of the principal direction. In the identification process, the principal direction of the test sample is first extracted to ascertain the corresponding bin. One-by-one matching with the training samples is then performed in the bin. To improve recognition efficiency while maintaining better recognition accuracy, two neighborhood bins of the corresponding bin are continuously searched to identify the input palm-vein image. Evaluation experiments are conducted on three different databases, namely, PolyU, CASIA, and the database of this study. Experimental results show that the searching range of one test sample in PolyU, CASIA and our database by the proposed method for palm-vein identification can be reduced to 14.29%, 14.50%, and 14.28%, with retrieval accuracy of 96.67%, 96.00%, and 97.71%, respectively. With 10,000 training samples in the database, the execution time of the identification process by the traditional method is 18.56 s, while that by the proposed approach is 3.16 s. The experimental results confirm that the proposed approach is more efficient than the traditional method, especially for a large database.

The umbilical and paraumbilical veins of man.

OpenAIRE

Martin, B F; Tudor, R G

1980-01-01

During its transit through the umbilicus structural changes occur in the thick wall of the extra-abdominal segment of the umbilical vein whereby the components of the intra-abdominal segment acquire an essentially longitudinal direction and become arranged in fibro-elastic and fibro-muscular zones. The vein lumen becomes largely obliterated by asymmetrical proliferation of loose subendothelial conective tissue. The latter forms a new inner zone within which a small segment of the lumen persis...

Aneurysmal malformation of the extrahepatic portal vein: a case report

International Nuclear Information System (INIS)

Lee, Jeong Min; Kang, Sung Soo; Kim, Chong Soo; Han, Hyeun Young

1999-01-01

Aneurysmal malformation of the portal vein is a rare entity. To our knowledge, only scattered reports of portal vein aneurysms appear in the literature in English, and there is no previously published report in Korean. We describe a case exhibiting aneurysmal malformation of the extrahepatic portal vein at the hepatic hilum ; the findings demonstrated by ultrasound, CT and angiography are discussed, a review of previously described cases is included

Congenital vascular malformations: the persistence of marginal and embryonal veins.

Science.gov (United States)

Weber, J; Daffinger, N

2006-05-01

In about 18% of cases with conginental vascular malformations we find a perspective of an atypical truncular vein, located along the outside of the leg, frequently extended from the dorsal foot up to the bottom. In presence of a normally developed system of the deep collecting veins of the lower limb and within the pelvic outflow we are talking about a persisting marginal vein (MV). Hypoplasia or even aplasia of the main deep veins in contrary defines the persisting embryonal vein (EV). Already in childhood these truncular dysplastic veins tend to develop varicose enlargement, causing severe reflux of a huge volume of blood--even more when being associated with av-fistulas (46%). In consequence a rapidly growing chronic venous insufficiency will guide to additional injuries. We have analysed 97 patients showing a persisting MV (n: 92 ) within a total of 102 legs. A persistent embryonal vein (EV) was seen 10 times within this clientel. The persisting truncular veins, associated with phlebectasias and typical clinical symptoms have been examined in a diagnostic "step-by-step" procedure, mainly phlebographically (ascending leg phlebography and varicography), including direct venous blood pressure measurements (phlebodynamometry) and--if needed--by arteriography, showing av-shunting fistulae in 46% of cases. CT and MRI were consulted for the exact therapy planing (frequently initially offered as a non-invasive, however, inadequate key of diagnostic). Actually now these techniques cannot replace pre-operatively the angiographic imaging techniques. The analysis of clinical, morphologic and functional signs, guiding to a specific therapy-relevant classification of MV's and EV's will be presented. And a specific strategy of surgical repair, interventional treatment of av-fistulas and conservative compressive follow-up treatment attempting palliative recompensation of the diseased venous outflow will be discussed also.

Contralateral Deep Vein Thrombosis after Iliac Vein Stent Placement in Patients with May-Thurner Syndrome.

Science.gov (United States)

Le, Trong Binh; Lee, Taeg Ki; Park, Keun-Myoung; Jeon, Yong Sun; Hong, Kee Chun; Cho, Soon Gu

2018-04-25

To investigate the incidence and potential causes of contralateral deep vein thrombosis (DVT) after common iliac vein (CIV) stent placement in patients with May-Thurner syndrome (MTS). Data of 111 patients (women: 73%) who had CIV stent implantation for symptomatic MTS at a single center were retrospectively analyzed. Mean patient age was 63.1 ± 15.2 years. Median follow-up was 36 months (range, 1-142 months). Stent location was determined by venogram and classified as extended to the inferior vena cava (IVC), covered the confluence, or confined to the iliac vein. Potential causes of contralateral DVT were presumed based on venographic findings. The relationship between stent location and contralateral DVT was analyzed. Ten patients (9%, men/women: 4/6) exhibited contralateral DVT at a median timing of 40 months (range, 6-98 months). Median age was 69 years (range, 42-85 years). Median follow-up was 73.5 months (range, 20-134 months). Potential causes were venous intimal hyperplasia (VIH) (n = 7), "jailing" (n = 2), and indeterminate (n = 1). All patients with VIH had previous CIV stents overextended to the IVC. Overextension of CIV stent was associated with contralateral DVT (P VIH should be considered a potential cause. Copyright © 2018 SIR. Published by Elsevier Inc. All rights reserved.

Morphology of congenital portosystemic shunts involving the left colic vein in dogs and cats.

Science.gov (United States)

White, R N; Parry, A T

2016-05-01

To describe the anatomy of congenital portosystemic shunts involving the left colic vein in dogs and cats. Retrospective review of a consecutive series of dogs and cats managed for congenital portosystemic shunts. For inclusion a shunt involving the left colic vein with recorded intraoperative mesenteric portovenography or computed tomography angiography along with direct gross surgical observations at the time of surgery was required. Six dogs and three cats met the inclusion criteria. All cases had a shunt which involved a distended left colic vein. The final communication with a systemic vein was variable; in seven cases (five dogs, two cats) it was via the caudal vena cava, in one cat it was via the common iliac vein and in the remaining dog it was via the internal iliac vein. In addition, two cats showed caudal vena cava duplication. The morphology of this shunt type appeared to be a result of an abnormal communication between either the left colic vein or the cranial rectal vein and a pelvic systemic vein (caudal vena cava, common iliac vein or internal iliac vein). This information may help with surgical planning in cases undergoing shunt closure surgery. © 2016 British Small Animal Veterinary Association.

Plantar vein thrombosis: a rare cause of plantar foot pain

International Nuclear Information System (INIS)

Siegal, Daniel S.; Wu, Jim S.; Brennan, Darren D.; Hochman, Mary G.; Challies, Tracy

2008-01-01

Plantar vein thrombosis is a rare condition, with only a handful of cases reported in the literature. The cause is unknown; however, the disease has been attributed to prior surgery, trauma, and paraneoplastic conditions. We present a case of a 32-year-old female runner with plantar vein thrombosis diagnosed on contrast-enhanced MRI and confirmed on ultrasound. The symptoms resolved with conservative treatment and evaluation revealed the presence of a prothrombin gene mutation and use of oral contraceptive pills. To our knowledge, this is the first case of plantar vein thrombosis diagnosed initially by MRI. Moreover, this case suggests that plantar vein thrombosis should be considered in patients with hypercoagulable states and plantar foot pain. (orig.)

Plantar vein thrombosis: a rare cause of plantar foot pain

Energy Technology Data Exchange (ETDEWEB)

Siegal, Daniel S.; Wu, Jim S.; Brennan, Darren D.; Hochman, Mary G. [Beth Israel Deaconess Medical Center, Department of Radiology, Boston, MA (United States); Challies, Tracy [Beth Israel Deaconess Medical Center, Department of Pathology, Boston, MA (United States)

2008-03-15

Plantar vein thrombosis is a rare condition, with only a handful of cases reported in the literature. The cause is unknown; however, the disease has been attributed to prior surgery, trauma, and paraneoplastic conditions. We present a case of a 32-year-old female runner with plantar vein thrombosis diagnosed on contrast-enhanced MRI and confirmed on ultrasound. The symptoms resolved with conservative treatment and evaluation revealed the presence of a prothrombin gene mutation and use of oral contraceptive pills. To our knowledge, this is the first case of plantar vein thrombosis diagnosed initially by MRI. Moreover, this case suggests that plantar vein thrombosis should be considered in patients with hypercoagulable states and plantar foot pain. (orig.)

Persistent Left Superior Vena Cava Associated with Hemiazygos Vein Draining in It and Absence of Left Brachiocephalic Vein, in a Patient with Congenital Heart Defect

Directory of Open Access Journals (Sweden)

Opincariu Diana

2016-09-01

Full Text Available Persistent left superior vena cava is an anomalous vein that derives from a malfunction of obliteration of the left common cardinal vein during intrauterine life. The diagnosis can be suggested by a dilated coronary sinus as seen in echocardiography, or other imagistic methods. Due to the lack of hemodynamic impairment, and consequently with few or no symptoms, this vascular anomaly is frequently discovered incidentally. In this brief report we present the case of a 35-year-old male known with a complex congenital cardiovascular malformation that included atrial septum defect, persistent left superior vena cava and anomalous right pulmonary vein drainage in the PLSVC, diagnosed with sinoatrial block that required pacemaker implantation. Due to the patient’s medical history, investigations to decide the best approach needed for pacemaker implantation were performed, including a thoracic CT that incidentally found additional anomalies — the hemiazygos vein draining in PLSVC and the lack of the left brachiocephalic vein.

Collateral veins in inferior caval vein occlusion demonstrated via CT

International Nuclear Information System (INIS)

Lien, H.H.; Lund, G.

1983-01-01

CT-scans of 12 patients with tumour-induced occlusion of the inferior vena cava were studied with regard to collateral veins. A comparison was performed with findings at phlebography in 10 patients and at autopsy in 2. The site and appearance of the main collateral pathway are presented. A close study of vascular structures renders useful information on collateral circulation in occlusion of the inferior vena cava. (orig.)

Enhancement of gold recovery using bioleaching from gold concentrate

Science.gov (United States)

Choi, S. H.; Cho, K. H.; Kim, B. J.; Choi, N. C.; Park, C. Y.

2012-04-01

The gold in refractory ores is encapsulated as fine particles (sometimes at a molecular level) in the crystal structure of the sulfide (typically pyrite with or without arsenopyrite) matrix. This makes it impossible to extract a significant amount of refractory gold by cyanidation since the cyanide solution cannot penetrate the pyrite/arsenopyrite crystals and dissolve gold particles, even after fine grinding. To effectively extract gold from these ores, an oxidative pretreatment is necessary to break down the sulfide matrix. The most popular methods of pretreatment include nitric acid oxidation, roasting, pressure oxidation and biological oxidation by microorganisms. This study investigated the bioleaching efficiency of Au concentrate under batch experimental conditions (adaptation cycles and chemical composition adaptation) using the indigenous acidophilic bacteria collected from gold mine leachate in Sunsin gold mine, Korea. We conducted the batch experiments at two different chemical composition (CuSO4 and ZnSO4), two different adaptation cycles 1'st (3 weeks) and 2'nd (6 weeks). The results showed that the pH in the bacteria inoculating sample decreased than initial condition and Eh increased. In the chemical composition adaptation case, the leached accumulation content of Fe and Pb was exhibited in CuSO4 adaptation bacteria sample more than in ZnSO4 adaptation bacteria samples, possibly due to pre-adaptation effect on chalcopyrite (CuFeS2) in gold concentrate. And after 21 days on the CuSO4 adaptation cycles case, content of Fe and Pb was appeared at 1'st adaptation bacteria sample(Fe - 1.82 and Pb - 25.81 times per control sample) lower than at 2'nd adaptation bacteria sample(Fe - 2.87 and Pb - 62.05 times per control sample). This study indicates that adaptation chemical composition and adaptation cycles can play an important role in bioleaching of gold concentrate in eco-/economic metallurgy process.

Characteristics of the streak clays of the hyacinth gold deposit by the techniques of DRX and AT

International Nuclear Information System (INIS)

Trueba Gaetano, R.; Cabrera Diaz, I.; Casanova Gomez, A.; Aguila Terry, A.; Martinez Montalvo, A.; Canel Carreras, L.; Rodriguez Garcia, J. C.; Alonso Perez, J. A.

2016-01-01

It is exposed the investigative work of the mineralogical characteristics of different types of clays present in the veins of the Oro Jacinto deposit through the use of XRD and TA analytical techniques, supported by a study of particle size in the range of 2 mm to 63 μm. Significant feature of these samples is that being crushed they generated high content of fine material below 0.074 mm. This size particles range is presented between 17.68% and 50.78% of samples volume, majority particles being smaller than 0.063 mm, this interstratificated fine material with different types of clay makes the fraction below 74 μm present characteristics of clayey material. The results of XRD analysis and comparative Thermo gravimetric that are achieved for samples of 'Jacinto' gold vein deposit indicate that the clays presented in the fine fractions are: chlorite-montmorillonite; illite; hidromoscovite and muscovite, which turned out to be higher in samples of the grain B eatriz . During the ores formation process of the veins S ur Elena , it is evident that the hydrothermal fluids that led to the formation of the rocks, experienced greater degree of alteration during its transformation into argillite, which is manifested in three mineralogical regularities: Low crystallinity of the chlorite-montmorillonite clay. Transformation of muscovite - hidromoscovite into illite. Presence of abundant calcite in some samples. Higher concentrations of iron oxides (goethite). (Author)

Arabidopsis thickvein Mutation Affects Vein Thickness and Organ Vascularization, and Resides in a Provascular Cell-Specific Spermine Synthase Involved in Vein Definition and in Polar Auxin Transport1

Science.gov (United States)

Clay, Nicole K.; Nelson, Timothy

2005-01-01

Polar auxin transport has been implicated in the induction of vascular tissue and in the definition of vein positions. Leaves treated with chemical inhibitors of polar auxin transport exhibited vascular phenotypes that include increased vein thickness and vascularization. We describe a recessive mutant, thickvein (tkv), which develops thicker veins in leaves and in inflorescence stems. The increased vein thickness is attributable to an increased number of vascular cells. Mutant plants have smaller leaves and shorter inflorescence stems, and this reduction in organ size and height is accompanied by an increase in organ vascularization, which appears to be attributable to an increase in the recruitment of cells into veins. Furthermore, although floral development is normal, auxin transport in the inflorescence stem is significantly reduced in the mutant, suggesting that the defect in auxin transport is responsible for the vascular phenotypes. In the primary root, the veins appear morphologically normal, but root growth in the tkv mutant is hypersensitive to exogenous cytokinin. The tkv mutation was found to reside in the ACL5 gene, which encodes a spermine synthase and whose expression is specific to provascular cells. We propose that ACL5/TKV is involved in vein definition (defining the boundaries between veins and nonvein regions) and in polar auxin transport, and that polyamines are involved in this process. PMID:15894745

Iliac vein stenosis is an underdiagnosed cause of pelvic venous insufficiency.

Science.gov (United States)

Santoshi, Ratnam K N; Lakhanpal, Sanjiv; Satwah, Vinay; Lakhanpal, Gaurav; Malone, Michael; Pappas, Peter J

2018-03-01

Reflux in the ovarian veins, with or without an obstructive venous outflow component, is reported to be the primary cause of pelvic venous insufficiency (PVI). The degree to which venous outflow obstruction plays a role in PVI is currently ill-defined. We retrospectively reviewed the charts of 227 women with PVI who presented to the Center for Vascular Medicine from January 2012 to September 2015. Assessments and interventions consisted of an evaluation for other causes of chronic pelvic pain by a gynecologist; preintervention and postintervention visual analog scale (VAS) pain score; complete venous duplex ultrasound examination; and Clinical, Etiology, Anatomy, and Pathophysiology classification. All patients underwent diagnostic venography of their pelvic and left ovarian veins as well as intravascular ultrasound of their iliac veins. Patients were treated in one of six ways: ovarian vein embolization (OVE) alone (chemical ± coils), OVE with staged iliac vein stenting, OVE with simultaneous iliac vein stenting, iliac vein stenting alone, OVE with venoplasty, and venoplasty alone. Of the 227 women treated, the average age and number of pregnancies was 46.4 ± 10.4 years and 3.36 ± 1.99, respectively. Treatment distribution was the following: OVE, n = 39; OVE with staged stenting, n = 94; OVE with simultaneous stenting, n = 33; stenting alone, n = 50; OVE with venoplasty, n = 8; and venoplasty alone, n = 3. Seven patients in the OVE and stenting groups (staged) and one patient in the OVE + venoplasty group required a second embolization of the left ovarian vein. Eighty percent (181/227) of patients demonstrated an iliac stenosis >50% by intravascular ultrasound. Average VAS scores for the entire cohort before and after intervention were 8.45 ± 1.11 and 1.86 ± 1.61 (P ≤ .001). In the staged group, only 9 of 94 patients reported a decrease in the VAS score with OVE alone. VAS score decreased from 8.6 ± 0.89 before OVE to 7.97 ± 2.10 after OVE

Enrichment of Gold in Antimony Matte by Direct Smelting of Refractory Gold Concentrate

Science.gov (United States)

Yang, Tianzu; Xie, Boyi; Liu, Weifeng; Zhang, Duchao; Chen, Lin

2018-06-01

Conventional cyanidation technology achieves low gold recovery when used to process refractory gold concentrate. Based on the geochemical characteristics of gold deposit mineralization, a new method is proposed herein for gold enrichment in antimony matte by smelting of refractory gold concentrate. The effects of the FeO/SiO2 and CaO/SiO2 ratios, smelting temperature, and smelting time on the gold recovery were investigated in detail. The optimum conditions were determined to be FeO/SiO2 ratio of 1.2, CaO/SiO2 ratio of 0.4, smelting temperature of 1200°C, and smelting time of 45 min. The gold content in antimony matte and smelting slag was 96.68 and 1.13 g/t, respectively. The gold, antimony, and arsenic recovery was 97.72%, 26.89%, and 6.56%, respectively, with most of the antimony and arsenic volatilized into dust. Mineral liberation analyzer results showed that the antimony matte mainly consisted of FeS and FeO, with three phases, viz. FeAs, SbAs, and AuSb, embedded between them, indicating that gold was easily enriched with antimony and arsenic during smelting of refractory gold concentrate.

Enrichment of Gold in Antimony Matte by Direct Smelting of Refractory Gold Concentrate

Science.gov (United States)

Yang, Tianzu; Xie, Boyi; Liu, Weifeng; Zhang, Duchao; Chen, Lin

2018-04-01

Conventional cyanidation technology achieves low gold recovery when used to process refractory gold concentrate. Based on the geochemical characteristics of gold deposit mineralization, a new method is proposed herein for gold enrichment in antimony matte by smelting of refractory gold concentrate. The effects of the FeO/SiO2 and CaO/SiO2 ratios, smelting temperature, and smelting time on the gold recovery were investigated in detail. The optimum conditions were determined to be FeO/SiO2 ratio of 1.2, CaO/SiO2 ratio of 0.4, smelting temperature of 1200°C, and smelting time of 45 min. The gold content in antimony matte and smelting slag was 96.68 and 1.13 g/t, respectively. The gold, antimony, and arsenic recovery was 97.72%, 26.89%, and 6.56%, respectively, with most of the antimony and arsenic volatilized into dust. Mineral liberation analyzer results showed that the antimony matte mainly consisted of FeS and FeO, with three phases, viz. FeAs, SbAs, and AuSb, embedded between them, indicating that gold was easily enriched with antimony and arsenic during smelting of refractory gold concentrate.

The response of thrombosis in the portal vein or hepatic vein in hepatocellular carcinoma to radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Bae, Bong Kyung; Kim, Jae Chul [Dept. of Radiation Oncology, Kyungpook National University School of Medicine, Daegu (Korea, Republic of)

2016-09-15

The purpose of current study is to evaluate the response of the patients with portal vein thrombosis (PVT) or hepatic vein thrombosis (HVT) in hepatocellular carcinoma (HCC) treated with three-dimensional conformal radiation therapy (3D-CRT). In addition, survival of patients and potential prognostic factors of the survival was evaluated. Forty-seven patients with PVT or HVT in HCC, referred to our department for radiotherapy, were retrospectively reviewed. For 3D-CRT plans, a gross tumor volume (GTV) was defined as a hypodense filling defect area in the portal vein (PV) or hepatic vein (HV). Survival of patients, and response to radiation therapy (RT) were analyzed. Potential prognostic factors for survival and response to RT were evaluated. The median survival time of 47 patients was 8 months, with 1-year survival rate of 15% and response rate of 40%. Changes in Child-Pugh score, response to RT, Eastern cooperative oncology group performance status (ECOG PS), hepatitis C antibody (HCVAb) positivity, and additional post RT treatment were statistically significant prognostic factors for survival in univariate analysis (p = 0.000, p = 0.018, p = 0.000, p = 0.013, and p = 0.047, respectively). Of these factors, changes in Child-Pugh score, and response to RT were significant for patients' prognosis in multivariate analysis (p = 0.001 and p = 0.035, respectively). RT could constitute a reasonable treatment option for patients with PVT or HVT in HCC with acceptable toxicity. Changes in Child-Pugh score, and response to RT were statistically significant factors of survival of patients.

The risk of varicose veins in standing female workers

Directory of Open Access Journals (Sweden)

Tony Hidayat

2013-07-01

Full Text Available AbstrakLatar belakang:Varises sering terjadi pada karyawan yang harus bekerja dalam posisi kerja berdiri. Tujuan penelitian ini untuk mengetahui beberapa faktor risiko terhadap varises tungkai dan atau kaki di antara pekerja perempuan. Metode:Penelitian potong lintang ini dilakukan pada Januari-Maret 2010. Sampel penelitian yang dipilih secara purposif yang memenuhi kriteria inklusi penelitian di antara pekerja perempuan perlu bekerja dalam  posisi  kerja  berdiri.  Data  dikumpulkan  dengan  wawancara,  pemeriksaan  fisik  dan  observasi posisi kerja berdiri. Pengolahan data untuk menentukan faktor dominan terhadap varises menggunakan pendekatan risiko relatif.Hasil:Dari 152 karyawan yang terdapat 111 yang bersedia mengikuti penelitian, dan yang menderita varises tungkai dan atau kaki sebanyak 52,3% (53 orang. Sebagian besar responden berusia 18-35 tahun, memiliki masa kerja 3-17 tahun, bekerja dalam posisi kerja banyak berdiri. Sebagian kecil responden memiliki riwayat varises di dalam keluarga (13,51%, memakai kontrasepsi oral (11,71%, memiliki kebiasaan olah raga (18,02% dan memakai sepatu hak tinggi (11,71%. Faktor umur, pemakaian kontrasepsi oral, pemakaian sepatu hak tinggi, kebiasaan olah raga, posisi kerja berdiri, tempat kerja, dan masa kerja tidak berhubungan dengan varises tungkai dan atau kaki. Karyawan yang mempunyai dibandingkan dengan yang tidak mempunyai riwayat keluarga varises, berisiko 69% lebih tinggi menderita varises [risiko relatif (RR = 1,69; P = 0.121]. Kesimpulan:Karyawan yang mempunyai riwayat keluarga varises berisiko lebih tinggi menderita varises. (Health Science Indones 2013;1:47-50 Kata kunci:varises, posisi kerja berdiriAbstractBackground: Varicose veins often occur in employees who have to work in a position of standing work. The purpose of this study to determine risk factors for varicose veins and leg or foot among women workers.Methods: In this cross-sectional study in January-March 2010 the

The geology of the gold deposits of Prestea gold belt of Ghana ...

African Journals Online (AJOL)

This paper presents the geology of the gold deposits along the Prestea gold belt of Ghana to assist exploration work for new orebodies along the belt. Prestea district is the third largest gold producer in West Africa after Obuasi and Tarkwa districts (over 250 metric tonnes Au during the last century). The gold deposits are ...

A free vein graft cap influences neuroma formation after nerve transection.

Science.gov (United States)

Galeano, Mariarosaria; Manasseri, Benedetto; Risitano, Giovanni; Geuna, Stefano; Di Scipio, Federica; La Rosa, Paola; Delia, Gabriele; D'Alcontres, Francesco Stagno; Colonna, Michele R

2009-01-01

: Neuroma formation is a major problem in nerve surgery and consensus about its prevention has not been reached. It has been suggested that vein covering can reduce neuroma formation in transected nerves. In this article, the Authors propose an easy and novel method of covering by nerve stump capping with a free vein graft. : Neuroma-like lesions were created on the rat thigh sectioning the femoral nerve above its division in 16 animals. The proximal nerve stump was invaginated into the lumen of a 1.5 cm long femoral free vein graft on the right side, and the vein was closed on itself by microsurgical sutures to form a cap for the nerve stump. On the left side acting as the control neuroma, the nerve was cut and left uncovered. Histological and immunohistochemical assessment was used to quantify the degree of neuroma formation. : Significant differences were found in both neuroma size and axon-glia organization between the treated and control sides indicating that free vein graft capping reduced neuroma formation in comparison to uncovered nerve stumps. : Our results confirm that vein-covering of a transected nerve stump can be effective in reducing neuroma formation. Moreover, unlike previous works that buried the nerve into an adjacent vein left in place, our experiments showed that also the use of a free vein graft cap can hinder neuroma formation. Although translation of rat experiments to the clinics should be dealt with caution, our data suggest a careful clinical use of the technique. (c) 2009 Wiley-Liss, Inc. Microsurgery, 2009.

Gold Leaching Characteristics and Intensification of a High S and As-Bearing Gold Concentrate

Science.gov (United States)

Yang, Yong-bin; Liu, Xiao-liang; Jiang, Tao; Li, Qian; Xu, Bin; Zhang, Yan

Some high sulfur and arsenic-bearing gold concentrate has a gold leaching rate less than 80% by oxidation roasting-pickling-cyanidation process. The characteristics and intensification of gold leaching were studied systemically. By combining chemical composition and phase analysis, the low gold leaching rate was found to lie in the capsulation of gold by iron-containing phases including iron oxides, arsenopyrite and pyrite. 96.66% of gold in the industrial leaching residue was capsulated and 95.88% of the capsulated turned out to be in the iron-containing phases. The results of laboratory pickling-cyanidation experiments on the calcine and industrial leaching residue presented further demonstration for the fact that gold capsulated in the iron-containing phases was hard to be leached. However, the gold cyanide leaching rate of calcine could be raised over 95% by a reduction roasting-pickling pretreatment which played such a significant role in exposing the capsulated gold that gold leaching was intensified remarkably.

Oxidation state of gold and arsenic in gold-bearing arsenian pyrite

Energy Technology Data Exchange (ETDEWEB)

Simon, G.; Huang, H.; Penner-Hahn, J.E.; Kesler, S.E.; Kao, L.S. [Univ. of Michigan, Ann Arbor, MI (United States)

1999-07-01

XANES measurements on gold-bearing arsenian pyrite from the Twin Creeks Carlin-type gold deposits show that gold is present as both Au{sup 0} and Au{sup 1+} and arsenic is present as As{sup 1{minus}}. Au{sup 0} is attributed to sub-micrometer size inclusions of free gold, whereas Au{sup 1+} is attributed to gold in the lattice of the arsenian pyrite. STEM observations suggest that As{sup 1{minus}} is probably concentrated in angstrom-scale, randomly distributed layers with a marcasite or arsenopyrite structure. Ionic gold (Au{sup 1+}) could be concentrated in these layers as well, and is present in both twofold- and fourfold-coordinated forms, with fourfold-coordinated Au{sup 1+} more abundant. Twofold-coordinated Au{sup 1+} is similar to gold in Au{sub 2}S in which it is linearly coordinated to two sulfur atoms. The nature of fourfold-coordinated Au{sup 1+} is not well understood, although it might be present as an Au-As-S compound where gold is bonded in fourfold coordination to sulfur and arsenic atoms, or in vacancy positions on a cation site in the arsenian pyrite. Au{sup 1+} was probably incorporated into arsenian pyrite by adsorption onto pyrite surfaces during crystal growth. The most likely compound in the case of twofold-coordinated Au{sup 1+} was probably a tri-atomic surface complex such as S{sub pyrite}-Au{sup 1+}-S{sub bi-sulfide}H or Au{sup 1+}-S-Au{sup 1+}. The correlation between gold and arsenic might be related to the role of arsenic in enhancing the adsorption of gold complexes of this type on pyrite surfaces, possibly through semiconductor effects.

Galen's vein aneurysm as cause of heart failure

International Nuclear Information System (INIS)

Echeverria, Claudia; Cassalett, Gabriel; Franco, Jaime; Carrillo, Gustavo

2005-01-01

We present the case of a newborn admitted to the intensive care unit with a heart failure of difficult medical management. A large ductus arteriosus was found. It was surgically corrected, but the heart failure persisted and did not improve with medical treatment. Incidentally, a big Galen's vein aneurysm was found. Galen's vein aneurysm is a rare congenital pathology, originated by a fusion defect of the internal cerebral veins. Due to its low resistance, it produces a picture of high-output heart failure. Large defects may contain 50% to 60% of cardiac output. An aneurysm may be suspected in each newborn or infant with clinical picture of heart failure and right cardiac chamber dilation without any evidence of structural cardiac anomaly

Renal computed angiography. Part I: Renal CT phlebography. Renal veins variants

International Nuclear Information System (INIS)

Al-Amin, M.; Krupev, M.; Hadjidekov, V.; Plachkov, I.

2012-01-01

The changing trend in renal surgery, transplantation and minimal invasive urology implies preprocedure evaluation of renal veins. Development of imaging methods offers new possibilities for venographic visualization. The goal of this study is to present authors experience in visualization of renal veins using 64 MDCT and to evaluate the utility in assessments of their variants. 128 patients (68 females and 60 males, mean age 53,3) with urological complaints underwent 64MDCT examination including CT angiography. Contrast enhancement includes 3-4ml/sec injection flow of 90 ml contrast medium followed by 20 ml saline at the same rate. In 23 out of 128 examined patients some of the common variants of the renal vein is found. 64 MDCT angiography visualize very well renal veins and becomes method of choice in preoperative assessment of renal vein anatomy. (authors)

The psychological aspects of everyday functioning in a group of patients with varicose veins – an assessment with VEINES Qol/Sym for patients before and after varicose veins surgery

Directory of Open Access Journals (Sweden)

Łukasz Migdalski

2015-10-01

Full Text Available Psychological functioning of patients in early stages of venous insufficiency has not been a common subject of scientific investigation so far, even though this group of patients experiences many limitations in daily functioning, as well as psychological distress. Varicose veins are the most common type of venous insufficiency, with an epidemiology of up to 50% of the western population. The present study is concerned with the functioning of a group undergoing surgery of varicose veins. The operation was carried out in an ambulatory mode, and such psychological factors as acceptance of illness, anxiety–state, anxiety–trait, and wellbeing (treated as personality construct have been considered. It is the first time that such variables have been used with the new tool for assessing quality of life in venous diseases (VEINES Qol/Sym, and no previous findings about applying VEINES Qol/Sym to assess patients after varicose veins operations exist. The results are promising, especially for combining such psychological variables as anxiety, acceptance of illness, or wellbeing with specific venous measures of quality of life. It has been proved that there is a need for monitoring psychological variables in the group of patients in an early stage of chronic venous illness. Further research on other venous patient groups is necessary to fully understand the specificity of these groups.

Analysis of hepatic vein variations in healthy people with 64-slice spiral CT

International Nuclear Information System (INIS)

Zhang Rong; Li Yong; Shen Jun; Zeng Weike; Li Jieting; Huang Suiqiao; Liang Biling; Liu Chao

2007-01-01

Objective: To analyze variations of hepatic vein in healthy people with 64-slice spiral CT. Methods: Seventy-five healthy subjects underwent multi-slice spiral computed (MSCT) hepatic venography. The anatomy of the junction of the hepatic veins with the inferior vena cava and the intrahepatic drainage territory of the hepatic veins and tributaries were evaluated. The hepatic veins were classified according to three anatomic classification (Nakamura's, Marcos's and Kawasaki's classification) methods respectively. Results: There was a common trunk of the middle and left hepatic veins before joining the IVC in 86.7% (65/75)of the cases. In 13.3% (10/75)of the cases, the three main hepatic veins joined the IVC separately. The ratios of Nakamma's classification type A, B, C of hepatic veins were 49.4% (37/75), 37.3% (28/75), and 13.3% (10/75) respectively. The ratios of Marcos's classification type A, B, C of hepatic veins were 56.0% (42/75), 24.0% (18/75), and 20.0% (15/75) respectively. The ratios of Kawasaki's classification type I, II of hepatic vein were 40.0% (30/75) and 60.0% (45/75). Conclusion: Multi-slice spiral CT hepatic venography can provide visualization of peripheral hepatic venous branches in details. (authors)

Lattice location of gold in natural pyrite crystals

International Nuclear Information System (INIS)

Besten, Jacinta den; Jamieson, David N.; Ryan, Chris G.

1999-01-01

The lattice location of gold atoms in naturally occurring Au-doped pyrite crystals has been investigated with a nuclear microprobe using ion channeling. The specimens consisted of 300-μm diameter pyrite crystals in veins embedded in a quartz matrix from the Emperor mine in Fiji. The specimens were prepared by standard geological specimen preparation techniques and the pyrite crystals were analysed in situ in the quartz matrix. Significant trace elements in the crystals, determined by Proton Induced X-ray Emission with a 3 MeV H + microprobe, were Cu, As, Mo, Zn, Te, Au and Pb. The Au concentration was about 0.2 wt%. By the use of 2 MeV He + ion channeling, the Miller indices of the lowest order crystal axes nearest to the normal were determined from backscattering yield maps from two-dimensional angular scanning and comparison of the resulting patterns with published gnomonic projections. Channeling angular yield curves were obtained from Fe, S, As and Au signals. The results indicate that at least 35% of the Au is substituted onto lattice sites

Influence of shear stress and size on viability of endothelial cells exposed to gold nanoparticles

Science.gov (United States)

Fede, C.; Albertin, Giovanna; Petrelli, L.; De Caro, R.; Fortunati, I.; Weber, V.; Ferrante, Camilla

2017-09-01

Screening nanoparticle toxicity directly on cell culture can be a fast and cheap technique. Nevertheless, to obtain results in accordance with those observed in live animals, the conditions in which cells are cultivated should resemble the one encountered in live systems. Microfluidic devices offer the possibility to satisfy this requirement, in particular with endothelial cell lines, because they are capable to reproduce the flowing media and shear stress experienced by these cell lines in vivo. In this work, we exploit a microfluidic device to observe how human umbilical vein endothelial cells (HUVEC) viability changes when subject to a continuous flow of culture medium, in which spherical citrate-stabilized gold nanoparticles of different sizes and at varying doses are investigated. For comparison, the same experiments are also run in multiwells where the cells do not experience the shear stress induced by the flowing medium. We discuss the results considering the influence of mode of exposure and nanoparticle size (24 and 13 nm). We observed that gold nanoparticles show a lower toxicity under flow conditions with respect to static and the HUVEC viability decreases as the nanoparticle surface area per unit volume increases, regardless of size.

Incidence of Central Vein Stenosis and Occlusion Following Upper Extremity PICC and Port Placement

International Nuclear Information System (INIS)

Gonsalves, Carin F.; Eschelman, David J.; Sullivan, Kevin L.; DuBois, Nancy; Bonn, Joseph

2003-01-01

The purpose of this study was to determine the incidence of central vein stenosis and occlusion following upper extremity placement of peripherally inserted central venous catheters(PICCs) and venous ports. One hundred fifty-four patients who underwent venography of the ipsilateral central veins prior to initial and subsequent venous access device insertion were retrospectively identified. All follow-up venograms were interpreted at the time of catheter placement by one interventional radiologist over a 5-year period and compared to the findings on initial venography. For patients with central vein abnormalities, hospital and home infusion service records and radiology reports were reviewed to determine catheter dwelltime and potential alternative etiologies of central vein stenosis or occlusion. The effect of catheter caliber and dwell time on development of central vein abnormalities was evaluated. Venography performed prior to initial catheter placement showed that 150 patients had normal central veins. Three patients had central vein stenosis, and one had central vein occlusion. Subsequent venograms (n = 154)at the time of additional venous access device placement demonstrated 8 patients with occlusions and 10 with stenoses. Three of the 18 patients with abnormal follow-up venograms were found to have potential alternative causes of central vein abnormalities. Excluding these 3 patients and the 4 patients with abnormal initial venograms, a 7% incidence of central vein stenosis or occlusion was found in patients with prior indwelling catheters and normal initial venograms. Catheter caliber showed no effect on the subsequent development of central vein abnormalities. Patients who developed new or worsened central vein stenosis or occlusion had significantly (p =0.03) longer catheter dwell times than patients without central vein abnormalities. New central vein stenosis or occlusion occurred in 7% of patients following upper arm placement of venous access devices

Research and implementation of finger-vein recognition algorithm

Science.gov (United States)

Pang, Zengyao; Yang, Jie; Chen, Yilei; Liu, Yin

2017-06-01

In finger vein image preprocessing, finger angle correction and ROI extraction are important parts of the system. In this paper, we propose an angle correction algorithm based on the centroid of the vein image, and extract the ROI region according to the bidirectional gray projection method. Inspired by the fact that features in those vein areas have similar appearance as valleys, a novel method was proposed to extract center and width of palm vein based on multi-directional gradients, which is easy-computing, quick and stable. On this basis, an encoding method was designed to determine the gray value distribution of texture image. This algorithm could effectively overcome the edge of the texture extraction error. Finally, the system was equipped with higher robustness and recognition accuracy by utilizing fuzzy threshold determination and global gray value matching algorithm. Experimental results on pairs of matched palm images show that, the proposed method has a EER with 3.21% extracts features at the speed of 27ms per image. It can be concluded that the proposed algorithm has obvious advantages in grain extraction efficiency, matching accuracy and algorithm efficiency.

C1-esterase inhibitor protects against early vein graft remodeling under arterial blood pressure.

Science.gov (United States)

Krijnen, Paul A J; Kupreishvili, Koba; de Vries, Margreet R; Schepers, Abbey; Stooker, Wim; Vonk, Alexander B A; Eijsman, Leon; Van Hinsbergh, Victor W M; Zeerleder, Sacha; Wouters, Diana; van Ham, Marieke; Quax, Paul H A; Niessen, Hans W M

2012-01-01

Arterial pressure induced vein graft injury can result in endothelial loss, accelerated atherosclerosis and vein graft failure. Inflammation, including complement activation, is assumed to play a pivotal role herein. Here, we analyzed the effects of C1-esterase inhibitor (C1inh) on early vein graft remodeling. Human saphenous vein graft segments (n=8) were perfused in vitro with autologous blood either supplemented or not with purified human C1inh at arterial pressure for 6h. The vein segments and perfusion blood were analyzed for cell damage and complement activation. In addition, the effect of purified C1inh on vein graft remodeling was analyzed in vivo in atherosclerotic C57Bl6/ApoE3 Leiden mice, wherein donor caval veins were interpositioned in the common carotid artery. Application of C1inh in the in vitro perfusion model resulted in significantly higher blood levels and significantly more depositions of C1inh in the vein wall. This coincided with a significant reduction in endothelial loss and deposition of C3d and C4d in the vein wall, especially in the circular layer, compared to vein segments perfused without supplemented C1inh. Administration of purified C1inh significantly inhibited vein graft intimal thickening in vivo in atherosclerotic C57Bl6/ApoE3 Leiden mice, wherein donor caval veins were interpositioned in the common carotid artery. C1inh significantly protects against early vein graft remodeling, including loss of endothelium and intimal thickening. These data suggest that it may be worth considering its use in patients undergoing coronary artery bypass grafting. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Prospects of gold mineralization in the Gilgit-Baltistan Province of Pakistan

Science.gov (United States)

Shah, M. T.; Khan, S. D.; Tahirkheli, T.; Ahmad, L.; Miandad, S.; Rehman, A. U.; Ali, L.

2012-12-01

mainly pyrite and chalcopyrite with subordinate amount of bornite and tetrahedrite. Surface leaching of these phases to malachite, azurite and limonite is common. Quartz veining, silicification, carbonization and at places brecciation are the common features of these alteration zones. The concentrations of gold were found in the range of 3ppb to 112ppb, of Golo Das, Bagrot valley, Shigri Bala, Machulu and Ranthak areas respectively. The barren rock samples have generally of the multi-times enrichment of gold in the alteration zones. The sulfide mineralization along with gold in the alteration zones could be attributed to the hydrothermal/epithermal activity involving meteoric, igneous and or metamorphic fluid individually or mixture of these. The occurrence of dioritic intrusions (igneous fluid source) and the transitional dilated zones (metamorphic fluid source) on the major reactivated thrust fault (i.e., NSZ) in the vicinity of these alteration zones strengthen these observations. However, isotopic studies are underway to solve this problem. This study suggests that the alteration zones in the studied areas have the potential to be explored in detail for possible economical gold mineralization.

Compressed sensing approach for wrist vein biometrics.

Science.gov (United States)

Lantsov, Aleksey; Ryabko, Maxim; Shchekin, Aleksey

2018-04-01

The work describes features of the compressed sensing (CS) approach utilized for development of a wearable system for wrist vein recognition with single-pixel detection; we consider this system useful for biometrics authentication purposes. The CS approach implies use of a spatial light modulation (SLM) which, in our case, can be performed differently-with a liquid crystal display or diffusely scattering medium. We show that compressed sensing combined with above-mentioned means of SLM allows us to avoid using an optical system-a limiting factor for wearable devices. The trade-off between the 2 different SLM approaches regarding issues of practical implementation of CS approach for wrist vein recognition purposes is discussed. A possible solution of a misalignment problem-a typical issue for imaging systems based upon 2D arrays of photodiodes-is also proposed. Proposed design of the wearable device for wrist vein recognition is based upon single-pixel detection. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metabolic effects of portal vein sensing.

Science.gov (United States)

Mithieux, G

2014-09-01

The extrinsic gastrointestinal nerves are crucial in the sensing of nutrients and hormones and its translation in terms of control of food intake. Major macronutrients like glucose and protein are sensed by the extrinsic nerves located in the portal vein walls, which signal to the brain and account for the satiety phenomenon they promote. Glucose is sensed in the portal vein by neurons expressing the glucose receptor SGLT3, which activate the main regions of the brain involved in the control of food intake. Proteins indirectly act on food intake by inducing intestinal gluconeogenesis and its sensing by the portal glucose sensor. The mechanism involves a prior antagonism by peptides of the μ-opioid receptors present in the portal vein nervous system and a reflex arc with the brain inducing intestinal gluconeogenesis. In a comparable manner, short-chain fatty acids produced from soluble fibre act via intestinal gluconeogenesis to exert anti-obesity and anti-diabetic effects. In the case of propionate, the mechanism involves a prior activation of the free fatty acid receptor FFAR3 present in the portal nerves and a reflex arc initiating intestinal gluconeogenesis. © 2014 John Wiley & Sons Ltd.

Female Pelvic Vein Embolization: Indications, Techniques, and Outcomes

Energy Technology Data Exchange (ETDEWEB)

Lopez, Anthony James, E-mail: consultant@radiologist.co.uk [The Imaging Clinic (United Kingdom)

2015-08-15

Until recently, the main indication for pelvic vein embolization (PVE) in women was to treat pelvic venous congestion syndrome (PVC) but increasingly, patients with refluxing pelvic veins associated with leg varicosities are also being treated. A more unusual reason for PVE is to treat pelvic venous malformations, although such lesions may be treated with sclerotherapy alone. Embolotherapy for treating PVC has been performed for many years with several published studies included in this review, whilst an emerging indication for PVE is to treat lower limb varicosities associated with pelvic vein reflux. Neither group, however, has been subjected to an adequate randomized, controlled trial. Consequently, some of the information presented in this review should be considered anecdotal (level III evidence) at this stage, and a satisfactory ‘proof’ of clinical efficacy remains deficient until higher-level evidence is presented. Furthermore, a wide range of techniques not accepted by all are used, and some standardization will be required based on future mandatory prospective studies. Large studies have also clearly shown an unacceptably high recurrence rate of leg varicose veins following venous surgery. Furthermore, minimally or non-invasive imaging is now revealing that there is a refluxing pelvic venous source in a significant percentage of women with de novo leg varicose veins, and many more with recurrent varicosities. Considering that just over half the world’s population is female and a significant number of women not only have pelvic venous reflux, but also have associated leg varicosities, minimally invasive treatment of pelvic venous incompetence will become a common procedure.

Female Pelvic Vein Embolization: Indications, Techniques, and Outcomes

International Nuclear Information System (INIS)

Lopez, Anthony James

2015-01-01

Until recently, the main indication for pelvic vein embolization (PVE) in women was to treat pelvic venous congestion syndrome (PVC) but increasingly, patients with refluxing pelvic veins associated with leg varicosities are also being treated. A more unusual reason for PVE is to treat pelvic venous malformations, although such lesions may be treated with sclerotherapy alone. Embolotherapy for treating PVC has been performed for many years with several published studies included in this review, whilst an emerging indication for PVE is to treat lower limb varicosities associated with pelvic vein reflux. Neither group, however, has been subjected to an adequate randomized, controlled trial. Consequently, some of the information presented in this review should be considered anecdotal (level III evidence) at this stage, and a satisfactory ‘proof’ of clinical efficacy remains deficient until higher-level evidence is presented. Furthermore, a wide range of techniques not accepted by all are used, and some standardization will be required based on future mandatory prospective studies. Large studies have also clearly shown an unacceptably high recurrence rate of leg varicose veins following venous surgery. Furthermore, minimally or non-invasive imaging is now revealing that there is a refluxing pelvic venous source in a significant percentage of women with de novo leg varicose veins, and many more with recurrent varicosities. Considering that just over half the world’s population is female and a significant number of women not only have pelvic venous reflux, but also have associated leg varicosities, minimally invasive treatment of pelvic venous incompetence will become a common procedure

[Transposition of the cephalic vein in free flap breast reconstruction: Technical note].

Science.gov (United States)

Silhol, T; Suffee, T; Hivelin, M; Lantieri, L

2018-02-01

Free flaps have become a reliable practice for breast reconstruction. However, the venous congestion is still the most frequent reason of flap failure. It is due to bad quality of the internal mammary veins, a preferential superficial venous outflow of the flap or due to venous thrombosis. The transposition of the cephalic vein could useful in some cases. We describe the surgical technique and suggest an intraoperative algorithm. Seventeen patients (15 DIEP and 2 PAP) were included. Twenty nine point four percent had an unusable internal mammary vein, 23.5% a preferential superficial venous outflow and 47.1% a venous thrombosis. The length of the cephalic vein dissected varied from 15 to 25cm. The mean time of dissection was 39min. There was no flap failure after cephalic vein transposition. The sequelae were one or two scars on the arm without any functional morbidity. The transposition of the cephalic vein is a reliable, less morbid alternative in case of bad quality internal mammary vein with a good quality internal mammary artery, in case of an additional venous outflow necessity or in case of venous thrombosis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Portal vein thrombosis after splenectomy for beta-thalassemia major

International Nuclear Information System (INIS)

Al-Hawsawi, Zakaria M.; Tarawah, Ahmed M.; Hassan, Ruhul Amin A.; Haouimi, Ammar S.

2004-01-01

Portal vein thrombosis is a recognized complication after splenectomy for beta-thalassemia major due to the chronic hypercoagulable state which has been recognized to exist in childhood thalassemia and contribute to thromboembolic events. We reporting one patient with beta-thalassemia major developed portal vein thrombosis following splenectomy. (author)

Gold Returns

OpenAIRE

Robert J. Barro; Sanjay P. Misra

2013-01-01

From 1836 to 2011, the average real rate of price change for gold in the United States is 1.1% per year and the standard deviation is 13.1%, implying a one-standard-deviation confidence band for the mean of (0.1%, 2.1%). The covariances of gold's real rate of price change with consumption and GDP growth rates are small and statistically insignificantly different from zero. These negligible covariances suggest that gold's expected real rate of return--which includes an unobserved dividend yiel...

LOCAL LINE BINARY PATTERN FOR FEATURE EXTRACTION ON PALM VEIN RECOGNITION

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Jayanti Yusmah Sari

2015-08-01

Full Text Available In recent years, palm vein recognition has been studied to overcome problems in conventional systems in biometrics technology (finger print, face, and iris. Those problems in biometrics includes convenience and performance. However, due to the clarity of the palm vein image, the veins could not be segmented properly. To overcome this problem, we propose a palm vein recognition system using Local Line Binary Pattern (LLBP method that can extract robust features from the palm vein images that has unclear veins. LLBP is an advanced method of Local Binary Pattern (LBP, a texture descriptor based on the gray level comparison of a neighborhood of pixels. There are four major steps in this paper, Region of Interest (ROI detection, image preprocessing, features extraction using LLBP method, and matching using Fuzzy k-NN classifier. The proposed method was applied on the CASIA Multi-Spectral Image Database. Experimental results showed that the proposed method using LLBP has a good performance with recognition accuracy of 97.3%. In the future, experiments will be conducted to observe which parameter that could affect processing time and recognition accuracy of LLBP is needed

Coal-oil gold agglomeration assisted flotation to recover gold from refractory ore

Science.gov (United States)

Otsuki, A.; Yue, C.

2017-07-01

This study aimed to investigate the applicability of coal-oil gold agglomeration (CGA) assisted flotation to recover gold from a refractory ore. The ore with the grade of 2-5 g/t was tested with the CGA-flotation process in six different size fractions from 38 to 300 urn using different collector types and dosages. In addition, the flotation without CGA was performed under the same condition for comparison. The results showed that the higher gold grade and recovery were achieved by applying the CGA-flotation, compared with the flotation without CGA. More than 20-60 times grade increase from the head grade was obtained with CGA-flotation. The elemental analysis of gold and sulphur explained their relationship with gold recovery. The results well indicated the applicability of CGA to upgrade the refractory gold ore.

Percutaneous sclerotherapy of testicular vein insufficiency in persistent and recurrent varicocele

International Nuclear Information System (INIS)

Sigmund, G.; Baehren, W.; Gall, H.; Thon, W.

1986-01-01

Among 1217 retrograde phlebographies of left-sided idiopathic varicoceles 66 patients presented because of persistence or recurrence of varicocele, 34 of them after operation and 32 after sclerotherapy. After operation without success there was always - except for one case - a reflux passing the site of ligature. If persistence or recurrence of varicocele occured after sclerotherapy, the testicular (internal spermatic) vein was most often found to be obliterated at the junction with the renal vein and the sonographically proven reflux went via collaterals or unidentified veins which prevented a repeat sclerotheraphy. In 12 out of 32 patients after sclerotherapy a persistent main stem of the testicular vein allowed a second attempt of sclerotherapy. If sclerotherapy in patients after operation or previous sclerotherapy could be performed, it was an effective, low risk procedure on an outpatient basis just as in primary sclerotherapy of testicular vein insufficiency causing varicocele. (orig.) [de

Prediction of renovascualar hypertension by captopril-stimulated renal vein renin ratios

International Nuclear Information System (INIS)

Roubidoux, M.A.; Dunnick, N.R.; Svetkey, L.; Newmann, G.E.; Cohan, R.H.; Kadir, S.; Klotman, P.

1989-01-01

The authors have prospectively studied 114 patients with suspected renovascular hypertension to determine whether captopril-stimulated, selective, renal vein renin ratios could be used to predict renovascular hypertension. As judged by the response to correction of renal artery lesions, 14 patients had renovascular hypertension, and renal vein renin ratios were significant in eight (sensitivity 57%). Overall, the positive predictive value of renal vein renin ratios was 33%, and the negative predictive value was 89%. The authors concluded that, in patients with renal artery stenosis, renal vein renin ratios predict neither the need for conventional arteriography nor potential benefit from the correction of vascular insufficiency

Pregnancy causes diminished myogenic tone and outward hypotrophic remodeling of the cerebral vein of Galen.

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van der Wijk, Anne-Eva; Schreurs, Malou P H; Cipolla, Marilyn J

2013-04-01

Pregnancy increases the risk of several complications associated with the cerebral veins, including thrombosis and hemorrhage. In contrast to the cerebral arteries and arterioles, few studies have focused on the effect of pregnancy on the cerebral venous side. Here, we investigated for the first time the effect of pregnancy on the function and structure of the cerebral vein of Galen in rats. Our major finding was that cerebral veins from late-pregnant (LP, n=11) rats had larger lumen diameters and thinner walls than veins from nonpregnant (NP, n=13) rats, indicating that pregnancy caused outward hypotrophic remodeling of the vein of Galen. Moreover, veins from NP animals had a small amount of myogenic tone at 10 mm Hg (3.9±1.0%) that was diminished in veins during pregnancy (0.8±0.3%; Ppregnancy. Using immunohistochemistry, we show that the vein of Galen receives perivascular innervation, and that serotonergic innervation of cerebral veins is significantly higher in veins from LP animals. Outward hypotrophic remodeling and diminished tone of cerebral veins during pregnancy may contribute to the development of venous pathology through elevated wall tension and wall stress, and possibly by promoting venous blood stasis.

Anatomical and embryological considerations of renal vein abnormalities: The value of preoperative CT

International Nuclear Information System (INIS)

Hruby, W.; Hoelti, W.

1986-01-01

Renal vein abnormalities are an uncommon kind of vascular abnormality. The distribution in the general population is 1.5%-2.5% in unselected pathologic material. In 354 autopsies we have seen six cases of renal vein abnormalities; in 215 cases of major retroperitoneal surgery, seven renal vein abnormalities; and in 4,500 patients who underwent CT examinations of the retroperitoneal areas, 36 cases of atypical renal vein anatomy. The radiologist must be familiar with embryologic details to understand the development of renal vein abnormalities. The authors discuss the value of preoperative diagnosis for preventing a surgical disaster in major retroperitoneal surgery

Gold and gold-copper nanoparticles in 2-propanol: A radiation chemical study

International Nuclear Information System (INIS)

Dey, G.R.

2011-01-01

The studies on the reduction of Au 3+ to gold nanoparticles in presence and absence of Cu 2+ under deoxygenated conditions in 2-propanol by radiolytic method have been carried out. On γ-radiolysis, preliminary yellow colored solution of Au 3+ changed to purple color owing to gold nanoparticles formation, which exhibits an absorption peak at around 540 nm. In the presence of Cu 2+ , absorption of gold-copper nanoparticles, which was also produced during γ-radiolysis, was red shifted in contrast to the system containing no Cu 2+ . Under DLS studies the sizes of gold nanoparticles in the absence and the presence of Cu 2+ were found to be larger (>400 nm). However, in presence of polyethylene glycol, a stabilizer the nanoparticle sizes became smaller, sizes measured for gold and gold-copper nanoparticles are 40 and 140 nm, respectively. Moreover, the change in UV-vis spectra in the Cu 2+ and Au 3+ mixed system highlights the formation of gold-copper nanoparticles in core-shell type arrangement. - Highlights: → Present radiation chemical study highlights high reactivity of Au ·2+ with Cu 2+ . → Absorption of gold-copper nanoparticles is blue shifted as compared to copper nanoparticles. → Change in UV-vis spectra with dose emphasizes core-shell type arrangement of Au-Cu nanoparticles.

Gold in plants

International Nuclear Information System (INIS)

Girling, C.A.; Peterson, P.J.

1980-01-01

Many plants have the ability to take up gold from the soil and to accumulate it in their tisssue. Advances have been made in understanding these processes to the point where their exploitation in the field of prospecting for gold appears practically feasible. Neutron activation analysis is used for the determination of the small quantities of gold in plants

Distribution and composition of gold in porphyry gold systems: example from the Biely Vrch deposit, Slovakia

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Koděra, Peter; Kozák, Jaroslav; Brčeková, Jana; Chovan, Martin; Lexa, Jaroslav; Jánošík, Michal; Biroň, Adrián; Uhlík, Peter; Bakos, František

2018-03-01

The Biely Vrch deposit in the Western Carpathians is assigned to the shallow, sulfide-poor porphyry gold deposit type and has an exceptionally low Cu/Au ratio. According to 3-D geochemical models, there is a limited spatial correlation between Au and Cu due to the primary introduction of gold by a salt melt and Cu by low-density vapor. Despite a rough spatial correlation of gold grades with quartz stockwork intensity, gold is hosted mostly by altered rock, exclusively in native form. Three main gold mineral assemblages were recognized here. In the deepest parts of the system, the K- and Ca-Na silicate gold assemblage is associated with minerals of high-temperature alteration (plagioclase, K-feldspar, actinolite), with gold grades and fineness depending on depth and potassium content of the host rock: K-silicate alteration hosts the lowest fineness gold ( 914), whereas Ca-Na silicate alteration has the highest ( 983). The intermediate argillic gold assemblage is the most widespread, with gold hosted mainly by chlorite, illite, smectite, and interstratified illite-chlorite-smectite minerals. The gold fineness is mostly variable (875-990) and inherited from the former gold mineral assemblages. The latest advanced argillic gold assemblage has its gold mostly in kaolinite. The extremely high fineness ( 994) results from gold remobilization by late-stage aqueous magmatic-hydrothermal fluids. Uncommon bonanza-grade appears where the earlier gold mineral assemblages were further enriched by this remobilized gold. Primary precipitation of gold occurred during ascent and cooling of salt melts at 450 to 309 °C, mostly during retrograde quartz solubility.

Moessbauer study of the chemical state of gold in gold ores

International Nuclear Information System (INIS)

Wagner, F.E.; Marion, P.H.; Regnard, J.-R.

1986-01-01

Information on the chemical state of gold in gold ores has been obtained by 197 Au Moessbauer spectroscopy in cases where the state of this element cannot be determined by such standard methods as optical or electron microscopy. Ore concentrates consisting mainly of pyrite or arsenopyrite and roasted ore and matte samples were studied. The results yielded directly the respective amounts of metallic and chemically bound gold. Unless the gold is metallic, its chemical state in the ores turns out to be different from that in the minerals studied so far as reference materials. The chemical processes taking place during various treatments of the ores, such as roasting or leaching, can also be followed by Moessbauer spectroscopy. It is hoped that Moessbauer spectroscopy will eventually facilitate the development of more efficient methods of gold extraction

An unusual presentation of postpartum ovarian vein thrombosis

International Nuclear Information System (INIS)

Hakim, Fayaz A.; Khan, Nadra N.; Qushmaq, Khalid A.; Al-Shami, Sadiq Y.

2007-01-01

Ovarian vein thrombosis is a rare but potentially serious complication following childbirth. The majority of patients present during the first week postpartum, with fever and right lower quadrant abdominal pain. We report an unusual case of postpartum ovarian vein thrombosis who presented with fever, low backache, and painful thighs. A high index of suspicion is crucial to diagnose and treat this condition in order to avoid serious consequences. (author)

Sarpogrelate hydrochloride reduced intimal hyperplasia in experimental rabbit vein graft.

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Kodama, Akio; Komori, Kimihiro; Hattori, Keisuke; Yamanouchi, Dai; Kajikuri, Junko; Itoh, Takeo

2009-05-01

The selective 5-HT(2A) receptor antagonist sarpogrelate has been clinically used for treatment in atherosclerotic diseases. However, it remains unknown whether administration of sarpogrelate inhibits intimal hyperplasia seen in autologous vein grafts. Therefore, we sought to clarify this question using an experimental rabbit vein graft model. Male rabbits were divided into two groups: a control group and a sarpogrelate-treated group. The jugular vein was interposed in the carotid artery in reversed fashion for 4 weeks and intimal hyperplasia of the grafted vein was measured (n = 8, in each group). Acetylcholine (ACh)-induced endothelium-dependent relaxation was tested by precontraction with prostaglandin F(2alpha) (PGF(2alpha), 5 muM) (n = 5, in each). endothelial nitric oxide synthase (eNOS) protein expression and superoxide production of these veins were also assessed. The suppression of intimal hyperplasia was significantly greater in the sarpogrelate-treated group than in the control group. ACh induced an endothelium-dependent relaxation in the sarpogrelate-treated group (but not in the control group). In endothelium-intact strips from the sarpogrelate-treated group, the nitric oxide (NO) synthase inhibitor nitroarginine enhanced the PGF(2alpha)-induced contraction and blocked the ACh-induced relaxation. Immunoreactive eNOS protein expression was similar between the two groups but superoxide production (estimated from ethidium fluorescence) in endothelial cells was significantly smaller in the sarpogrelate-treated group. The present results indicate that in vivo blockade of 5-HT(2A) receptors leads to an inhibition of intimal hyperplasia in rabbit vein graft. It is suggested that an increased function of endothelium-derived NO through a reduction in endothelial superoxide production may be a possible underlying mechanism for this. These novel findings support the clinical usefulness of sarpogrelate for preventing intimal hyperplasia in vein graft after bypass

Spoof Detection for Finger-Vein Recognition System Using NIR Camera

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Dat Tien Nguyen

2017-10-01

Full Text Available Finger-vein recognition, a new and advanced biometrics recognition method, is attracting the attention of researchers because of its advantages such as high recognition performance and lesser likelihood of theft and inaccuracies occurring on account of skin condition defects. However, as reported by previous researchers, it is possible to attack a finger-vein recognition system by using presentation attack (fake finger-vein images. As a result, spoof detection, named as presentation attack detection (PAD, is necessary in such recognition systems. Previous attempts to establish PAD methods primarily focused on designing feature extractors by hand (handcrafted feature extractor based on the observations of the researchers about the difference between real (live and presentation attack finger-vein images. Therefore, the detection performance was limited. Recently, the deep learning framework has been successfully applied in computer vision and delivered superior results compared to traditional handcrafted methods on various computer vision applications such as image-based face recognition, gender recognition and image classification. In this paper, we propose a PAD method for near-infrared (NIR camera-based finger-vein recognition system using convolutional neural network (CNN to enhance the detection ability of previous handcrafted methods. Using the CNN method, we can derive a more suitable feature extractor for PAD than the other handcrafted methods using a training procedure. We further process the extracted image features to enhance the presentation attack finger-vein image detection ability of the CNN method using principal component analysis method (PCA for dimensionality reduction of feature space and support vector machine (SVM for classification. Through extensive experimental results, we confirm that our proposed method is adequate for presentation attack finger-vein image detection and it can deliver superior detection results compared

Spoof Detection for Finger-Vein Recognition System Using NIR Camera.

Science.gov (United States)

Nguyen, Dat Tien; Yoon, Hyo Sik; Pham, Tuyen Danh; Park, Kang Ryoung

2017-10-01

Finger-vein recognition, a new and advanced biometrics recognition method, is attracting the attention of researchers because of its advantages such as high recognition performance and lesser likelihood of theft and inaccuracies occurring on account of skin condition defects. However, as reported by previous researchers, it is possible to attack a finger-vein recognition system by using presentation attack (fake) finger-vein images. As a result, spoof detection, named as presentation attack detection (PAD), is necessary in such recognition systems. Previous attempts to establish PAD methods primarily focused on designing feature extractors by hand (handcrafted feature extractor) based on the observations of the researchers about the difference between real (live) and presentation attack finger-vein images. Therefore, the detection performance was limited. Recently, the deep learning framework has been successfully applied in computer vision and delivered superior results compared to traditional handcrafted methods on various computer vision applications such as image-based face recognition, gender recognition and image classification. In this paper, we propose a PAD method for near-infrared (NIR) camera-based finger-vein recognition system using convolutional neural network (CNN) to enhance the detection ability of previous handcrafted methods. Using the CNN method, we can derive a more suitable feature extractor for PAD than the other handcrafted methods using a training procedure. We further process the extracted image features to enhance the presentation attack finger-vein image detection ability of the CNN method using principal component analysis method (PCA) for dimensionality reduction of feature space and support vector machine (SVM) for classification. Through extensive experimental results, we confirm that our proposed method is adequate for presentation attack finger-vein image detection and it can deliver superior detection results compared to CNN

Pulmonary vein stenosis in patients with Smith-Lemli-Opitz syndrome.

Science.gov (United States)

Prosnitz, Aaron R; Leopold, Jane; Irons, Mira; Jenkins, Kathy; Roberts, Amy E

2017-07-01

To describe a group of children with co-incident pulmonary vein stenosis and Smith-Lemli-Opitz syndrome and to generate hypotheses as to the shared pathogenesis of these disorders. Retrospective case series. Five subjects in a pulmonary vein stenosis cohort of 170 subjects were diagnosed with Smith-Lemli-Opitz syndrome soon after birth. All five cases were diagnosed with Smith-Lemli-Opitz syndrome within 6 weeks of life, with no family history of either disorder. All cases had pathologically elevated 7-dehydrocholesterol levels and two of the five cases had previously reported pathogenic 7-dehydrocholesterol reductase mutations. Smith-Lemli-Opitz syndrome severity scores ranged from mild to classical (2-7). Gestational age at birth ranged from 35 to 39 weeks. Four of the cases were male by karyotype. Pulmonary vein stenosis was diagnosed in all cases within 2 months of life, earlier than most published cohorts. All cases progressed to bilateral disease and three cases developed atresia of at least one vein. Despite catheter and surgical interventions, all subjects' pulmonary vein stenosis rapidly recurred and progressed. Three of the subjects died, at 2 months, 3 months, and 11 months. Survival at 16 months after diagnosis was 43%. Patients with pulmonary vein stenosis who have a suggestive syndromic presentation should be screened for Smith-Lemli-Opitz syndrome with easily obtainable serum sterol tests. Echocardiograms should be obtained in all newly diagnosed patients with Smith-Lemli-Opitz syndrome, with a low threshold for repeating the study if new respiratory symptoms of uncertain etiology arise. Further studies into the pathophysiology of pulmonary vein stenosis should consider the role of cholesterol-based signaling pathways in the promotion of intimal proliferation. © 2017 Wiley Periodicals, Inc.

Anatomic relationship of intrahepatic bile ducts to portal veins revisited

International Nuclear Information System (INIS)

Bret, P.M.; Stempel, J.; Atri, M.; Lough, J.O.; Illescas, F.F.

1987-01-01

It is well accepted that intrahepatic bile ducts lie in front of corresponding portal vein branches. Since the authors' clinical experience with US was different, they studied 18 normal necropsy cadaver livers. The common bile duct, main portal vein, and hepatic artery were cannulated and injected respectively with air, dilute contrast medium, and mineral oil. The livers were then examined in anatomic position with CT. In the left lobe of the liver, the bile ducts were anterior to the portal vein in seven cases, posterior in seven cases, and were tortuous both anterior and posterior in three cases. In the right lobe, the bile ducts were anterior in nine cases, posterior in five cases, tortuous in one case, and not seen in two cases. In the porta hepatis, the bile ducts were anterior in eight cases, posterior in one case, tortuous in five cases, and not seen in three cases. Histologic specimens confirmed the anterior and posterior location of the bile ducts relative to the portal veins. In conclusion, intrahepatic bile ducts can be either anterior or posterior to the corresponding portal vein branches

Isolated Subclavian Vein Injury: A Rare and High Mortality Case

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Sahin Iscan

2013-01-01

Full Text Available Isolated subclavian vein injuries are rarely seen without concomitant arterial injury, bone fracture, damage to brachial plexus, and thoracal traumas. Our case was brought to the emergency service 6 hours after he had been shot at the shoulder with a firearm. After detection of extravasation from the left axillary and subclavian vein on arteriographic and venographic examinations, he was operated on. An autogenous saphenous vein graft was interposed between subclavian and axillary veins. Cardiac arrest developed twice because of hypovolemia, which was resolved with medical therapy. Subclavian vein injuries have a more mortal course when compared with the injuries to the subclavian arteries. Its most important reason is excessive blood loss and air embolism because of delayed arrival to hospital. As is the case in all vascular injuries, angiography is the most important diagnostic examination. If the general health state of the patient permits, arteriography and venography should be performed in patients potentially exposed to vascular injuries. In patients with extreme blood loss and deteriorated health state, direct surgical exploration of the injury site, containment of the bleeding, and venous repair are life-saving approaches.

Large vein injection alleviates rocuronium-induced pain in gynaecologic patients.

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Zhang, Xing-Mei; Wang, Qun; Wang, Wei-Si; Wang, Meng

2017-08-01

Rocuronium-induced pain upon injection is very common in the clinical setting. Using the antecubital rather than the hand vein can avoid pain due to propofol injection. We aimed to investigate whether the use of the antecubital vein for injection would alleviate rocuronium-induced pain in a similar fashion. Sixty patients (ASA classes I and II) scheduled for gynaecologic laparoscopy were randomised into two groups. Rocuronium (0.6mg/kg) was injected either into the vein on the dorsum of the hand (group D) or a large vein in the antecubital fossa (group A). Pain was assessed and recorded using a four-point scale. Compared with group D, the incidence of pain and severe pain was lower in group A patients. The rate of no pain was also higher in group A patients. The incidence and severity of rocuronium-induced injection pain were significantly alleviated via use of a large vein for rocuronium injection. Copyright © 2016 Société française d'anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.

Mineralization and hydrothermal alteration of the Tajroud vein system, south of Neyshabour

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Mohsen Alikhani Banghani

2013-10-01

Full Text Available The Tajroud vein system is located 190 km southwest of Mashhad, and in the southern part of the Sabzevar zone. The vein host rocks consist of Eocene intermediate to silicic volcanic rocks. The mineralization occurs as open space filling, taking place as veins, veinlets and hydrothermal breccias. Based on field geology and textural evidence, three main stages of mineralization were identified. Stage I mainly contains quartz, pyrite, chalcopyrite and magnetite. Stage II, which has the same mineral assemblage as stage I, is the most important stage in terms of volume. Finally, stage III is characterized by repetitive quartz and calcite banding with negligible amounts of sulfide minerals. Hydrothermal alteration is developed around the veins and tends to be more intense in the vicinity of the veins. The plot of the Ishikawa alteration index (AI versus chlorite-carbonate-pyrite index (CCPI, known as alteration box plot, displays three main alteration trends. The hydrothermal alteration assemblage of quartz, adularia, chlorite, illite, calcite, and epidote that envelops the Tajroud vein system formed from the upwelling of near-neutral to weakly alkaline hydrothermal solutions. The mineralogic, alteration and geochemical characteristics of the studied area and comparison with epithermal ore deposits indicate that the Tajroud vein system represents an epithermal system of low-sulfidation type.

CT imaging of collaterals in stenoses of large mediastinal veins

International Nuclear Information System (INIS)

Goerich, J.; Flentje, M.; Gueckel, F.; Beyer-Enke, S.A.; Kaick, G. van; Heidelberg Univ.

1988-01-01

Scans of angio-computed tomography (CT) of 53 patients suffering from mediastinal space-occupying growths were reviewed: 16 patients showed stenosis of mediastinal veins with demonstration of subcutaneous venous channels, 17 showed an obstruction without collateral pathways and 20 patients had normal mediastinal vessels. Two thirds of the cases with external vein compression were caused by bronchogenic carcinoma. The degree of obstruction in patients showing collateral circulation was between 70 and 100 percent and significantly greater than in patients without collaterals (40%). The most important collaterals bypassing the upper mediastinal veins are discussed. (orig.) [de

Silver, gold, and alloyed silver-gold nanoparticles: characterization and comparative cell-biologic action

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Mahl, Dirk; Diendorf, Jörg; Ristig, Simon; Greulich, Christina; Li, Zi-An; Farle, Michael; Köller, Manfred; Epple, Matthias

2012-10-01

Silver, gold, and silver-gold-alloy nanoparticles were prepared by citrate reduction modified by the addition of tannin during the synthesis, leading to a reduction in particle size by a factor of three. Nanoparticles can be prepared by this easy water-based synthesis and subsequently functionalized by the addition of either tris(3-sulfonatophenyl)phosphine or poly( N-vinylpyrrolidone). The resulting nanoparticles of silver (diameter 15-25 nm), gold (5-6 nm), and silver-gold (50:50; 10-12 nm) were easily dispersable in water and also in cell culture media (RPMI + 10 % fetal calf serum), as shown by nanoparticle tracking analysis and differential centrifugal sedimentation. High-resolution transmission electron microscopy showed a polycrystalline nature of all nanoparticles. EDX on single silver-gold nanoparticles indicated that the concentration of gold is higher inside a nanoparticle. The biologic action of the nanoparticles toward human mesenchymal stem cells (hMSC) was different: Silver nanoparticles showed a significant concentration-dependent influence on the viability of hMSC. Gold nanoparticles showed only a small effect on the viability of hMSC after 7 days. Surprisingly, silver-gold nanoparticles had no significant influence on the viability of hMSC despite the silver content. Silver nanoparticles and silver-gold nanoparticles in the concentration range of 5-20 μg mL-1 induced the activation of hMSC as indicated by the release of IL-8. In contrast, gold nanoparticles led to a reduction of the release of IL-6 and IL-8.

Classical varicose vein surgery in a diverse ethnic community.

Science.gov (United States)

Murli, N L; Navin, I D

2008-08-01

Chronic venous disorders range from telangiactasia or spider veins to varicose veins, venous swellings, skin changes and venous ulcerations. The aim of this study is to assess outcome of varicose vein surgery in the ethnically diverse population of Penang, Malaysia. This study is a retrospective analysis of patients seen from 1999 to 2004. All patients who presented to the outpatient clinic of our surgical department with saphenofemoral junction (SFJ) and/or saphenopopliteal junction (SPJ) reflux associated with incompetence of the great saphenous vein (GSV) or small saphenous vein (SSV) respectively underwent classical varicose varicose vein surgery. A single surgeon at a single institution performed the surgeries. Data from pre-operative, post-operative and follow-up procedures were recorded in case report forms. A total of 202 cases were treated. Of these, 200 were qualified by the inclusion criteria and follow-ups, with 23 who were treated bilaterally. Of those treated, Chinese comprised 47.5%, Indians 27.0%, Malays 12.5% and foreigners 13.0% (largely Indonesian Chinese, British and Americans). The average age was 52.1 years. Indians had the highest average BMI of 29.2, compared to the Chinese who had the lowest of 24.6. Based on occupation, housewives (43.0%), blue collar workers (19.0%), salespersons (12.0%) and factory workers (9.5%) were among those afflicted with varicose veins. While local Chinese predominated in the business groups (salespersons and food-related workers), the Indians and Malays in this study were mainly factory workers and/or blue collar workers. Symptomatology in descending order of severity included pain in 80.0% of cases, swelling in 65.5%, heaviness in 53.5%, cramps in 53.0%, lipodermatosclerosis in 39.0%, superficial thrombophlebitis in 33.5%, venous ulceration in 32.0%, eczema 22.0% and cellulitis in 12.5% of patients. Post surgery pains dropped to 9.9%, cramps 6.4%, heaviness 5.5% and swelling 5.3% (p<0.0001 in all groups

Structural control on gold mineralization in the Satulinmäki and Riukka prospects, Häme Schist Belt, southern Finland

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Kerstin Saalmann

2007-01-01

Full Text Available The Satulinmäki and Riukka prospects located in the Häme Schist Belt in southern Finland are dominated by mafic and intermediate to felsic metavolcanic rocks of the Forssa Group formed in a continental arc setting. This magmatic belt formed some 1890–1880 Ma ago and has been deformed during the Svecofennian orogeny. The dominant penetrative foliation is represented by Sn+1, which is axial planar to cm- to dm-scale iscolinal Fn+1 folds and thus parallel to the layering Sn. Associated ductile shearing might reflect early thrusting. Dn+2 post-dating peak metamorphism is characterized by small-scale to regional-scale refolding of Fn+1 folds around ~SW-NE fold axes. This phase is transitional to development of SW-NE to WSW-ENE and NW-SE striking shear zones and faults formed due to dextral transpressionduring Dn+3 at retrograde conditions crossing the brittle-ductile transition. Many mineralized quartz veins have formed during this event. Later faults and quartz veins and reactivation of pre-existing structures during Dn+4 indicate rotation of the stress field to ~NESWoriented compression. A clear ~SW-NE trend of sulphide mineralization and elevated gold contents and the spatial association to Dn+3 quartz veins, shear zones and faults suggest a strong structural control, typical of orogenic gold deposits, and that mineralization took place during Dn+3. The controlling structures, (i WSW-ENE to SW-NE shear zones and faults and (ii NW-SE oriented fault, are second and third order structures to major regional-scale shear zones. The fault zones and their intersection points impart a directional permeability so that the mineralising fluids were channelled along dilatant zones. Approximately (WNW-(ESE trending faults being (reactivated as extensional faults or dilatant shear planes during Dn+3 transpression with WNW-ESE to NW-SE oriented compression direction could have acted as conduits for fluids during upward flow from deeper crustal level. Future

Gold and palladium minerals (including empirical PdCuBiSe3) from the former Roter Bär mine, St. Andreasberg, Harz Mountains, Germany: a result of low-temperature, oxidising fluid overprint

Science.gov (United States)

Cabral, Alexandre Raphael; Ließmann, Wilfried; Lehmann, Bernd

2015-10-01

At Roter Bär, a former underground mine in the polymetallic deposits of St. Andreasberg in the middle-Harz vein district, Germany, native gold and palladium minerals occur very locally in clausthalite-hematite pockets of few millimetres across in carbonate veinlets. The native gold is a Au-Ag intermetallic compound and the palladium minerals are characterised as mertieite-II [Pd8(Sb,As)3] and empirical PdCuBiSe3 with some S. The latter coexists with bohdanowiczite (AgBiSe2), a mineral that is stable below 120 °C. The geological setting of Roter Bär, underneath a post-Variscan unconformity, and its hematite-selenide-gold association suggest that oxidising hydrothermal brines of low temperature were instrumental to the Au-Pd mineralisation. The Roter Bär Au-Pd mineralisation can be explained by Permo-Triassic, red-bed-derived brines in the context of post-Variscan, unconformity-related fluid overprint.

Jugular veins in transient global amnesia: innocent bystanders.

Science.gov (United States)

Baracchini, Claudio; Tonello, Simone; Farina, Filippo; Viaro, Federica; Atzori, Matteo; Ballotta, Enzo; Manara, Renzo

2012-09-01

Transient global amnesia (TGA) has been associated with an increased prevalence of internal jugular valve insufficiency and many patients report Valsalva-associated maneuvers before TGA onset. These findings have led to the assumption of hemodynamic alterations in intracranial veins inducing focal hippocampal ischemia. We investigated this hypothesis in patients with TGA and control subjects. Seventy-five patients with TGA and 75 age- and sex-matched healthy subjects were enrolled into a cross-sectional study. Extracranial and transcranial high-resolution venous echo-color-Doppler sonography was performed blindly in all patients and control subjects. Blood flow direction and velocities were recorded at the internal jugular veins, basal veins of Rosenthal, and vein of Galen, both at rest and during Valsalva-associated maneuvers. Mean age of patients with TGA was 60.3±8.0 years (median, 60 years; range, 44-78 years); 44 (59%) were female (female/male ratio: 1.42). Internal jugular valve insufficiency (left, right, or bilateral) was found to be more frequent in patients with TGA than in control subjects: 53 (70.7%) versus 22 (29.3%; P<0.05). Blood flow velocities in the deep cerebral veins of patients with TGA did not differ from control subjects both at rest and during Valsalva-associated maneuvers. Intracranial venous reflux was neither observed in patients with TGA nor in control subjects despite unilateral or bilateral internal jugular valve insufficiency during prolonged and maximal Valsalva-associated maneuvers. This study, although confirming the association between TGA and internal jugular valve insufficiency, challenges the hypothesis that cerebral venous congestion plays a significant role in the pathogenesis of TGA.

The Short Saphenous Vein: A Viable Alternative Conduit for ...

African Journals Online (AJOL)

This novel position allowed for two members of the surgical team to operate at the same time, thus ... along the ultrasound-marked vein positions similar to when harvesting the LSV. Once the veins were harvested and ... occlusion compared to LSV grafts utilized in the same procedure,[8] it was brought back to prominence ...

A Rabbit Model for Testing Helper-Dependent Adenovirus-Mediated Gene Therapy for Vein Graft Atherosclerosis.

Science.gov (United States)

Bi, Lianxiang; Wacker, Bradley K; Bueren, Emma; Ham, Ervin; Dronadula, Nagadhara; Dichek, David A

2017-12-15

Coronary artery bypass vein grafts are a mainstay of therapy for human atherosclerosis. Unfortunately, the long-term patency of vein grafts is limited by accelerated atherosclerosis. Gene therapy, directed at the vein graft wall, is a promising approach for preventing vein graft atherosclerosis. Because helper-dependent adenovirus (HDAd) efficiently transduces grafted veins and confers long-term transgene expression, HDAd is an excellent candidate for delivery of vein graft-targeted gene therapy. We developed a model of vein graft atherosclerosis in fat-fed rabbits and demonstrated long-term (≥20 weeks) persistence of HDAd genomes after graft transduction. This model enables quantitation of vein graft hemodynamics, wall structure, lipid accumulation, cellularity, vector persistence, and inflammatory markers on a single graft. Time-course experiments identified 12 weeks after transduction as an optimal time to measure efficacy of gene therapy on the critical variables of lipid and macrophage accumulation. We also used chow-fed rabbits to test whether HDAd infusion in vein grafts promotes intimal growth and inflammation. HDAd did not increase intimal growth, but had moderate-yet significant-pro-inflammatory effects. The vein graft atherosclerosis model will be useful for testing HDAd-mediated gene therapy; however, pro-inflammatory effects of HdAd remain a concern in developing HDAd as a therapy for vein graft disease.

Straight configuration saphenous vein transposition to popliteal artery for vascular access.

Science.gov (United States)

Caco, Gentian; Golemi, Dhurata; Likaj, Eriola

2017-03-21

The saphenous vein is commonly used as a vascular graft in peripheral artery surgery but rarely used for vascular access. The literature on straight configuration saphenous vein transposition to the popliteal artery is scarce. Here we present two cases of straight configuration saphenous vein transposition to the popliteal artery for vascular access, the surgical technique and respective follow-up. Two young men, aged 29 and 36 years, were chosen for lower-limb vascular access for hemodialysis. The first patient was paraplegic since birth. He used his arms to move so upper extremity vascular access was avoided. The second patient presented with an infected upper extremity arteriovenous graft (AVG) and after multiple closed AVFs he had no more available arm veins. Both patients received autologous lower extremity straight configuration saphenous vein transpositions to the popliteal artery under spinal anesthesia in May and October 2012, respectively. Cannulation of the fistula was allowed after one month. There were no early complications. Slight swelling on the leg appeared in one of the patients. Both fistulas were still functional after 36 and 32 months, respectively. The straight configuration saphenous vein transposition to popliteal artery is simple to perform, offers a long and straight segment for cannulation and may be a suitable autologous vascular access in selected patients.