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Sulphur hexafluoride

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https://www.readbyqxmd.com/read/30022817/feasibility-and-challenges-of-using-multiple-breath-washout-in-copd
#1
Alan S Bell, Philip J Lawrence, Dave Singh, Alexander Horsley
Background: Lung clearance index (LCI), derived from multiple-breath washout (MBW), is a well-established assessment of ventilation inhomogeneity in cystic fibrosis but has not been widely applied in other conditions characterized by heterogeneous airways disease, such as COPD. The aim of this study was to evaluate the sensitivity, repeatability, and practicality of LCI in patients with COPD. Methods: Fifty-four COPD patients completed MBW using nitrogen as the washout tracer gas (MBWN2 , measured using an Exhalyzer™ device), spirometry, and plethysmography...
2018: International Journal of Chronic Obstructive Pulmonary Disease
https://www.readbyqxmd.com/read/28886633/ir-spectroscopic-study-of-the-displacement-of-an-sf-6-monolayer-on-graphite-by-xe
#2
G B Hess, Yu Xia
We report a study of displacement by xenon of a monolayer of sulphur hexafluoride initially condensed on a graphite surface. Earlier work showed that, below 112 K, Xe displaces SF6 almost completely in a first-order transition. Working at higher temperatures, we show that this system has a simple eutectic-like phase diagram, at least for SF6 not too dilute. In our experiment, both adsorbates are in equilibrium with their respective vapors in a cold cell. In our infrared reflection-absorption spectroscopy measurements, the SF6 coverage on the surface is monitored by the frequency shift due to dynamic dipole coupling of the collective mode of the strong SF6 ν3 vibrational resonance...
September 7, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28885211/postoperative-control-of-functional-muscle-flaps-for-facial-palsy-reconstruction-ultrasound-guided-tissue-monitoring-using-contrast-enhanced-ultrasound-ceus-and-ultrasound-elastography
#3
Andreas Kehrer, Veronika Mandlik, Christian Taeger, Sebastian Geis, Lukas Prantl, Ernst-Michael Jung
BACKGROUND AND OBJECTIVES: Facial paralysis causes excruciating impairments including facial asymmetry, limited eye closure, oral incontinence and social dysfunction. Modern plastic surgical reconstructions render favorable results with well-perfused dynamic muscle flaps. Post-operative tissue monitoring is a critical determinant for success. Contrast-enhanced Ultrasound (CEUS) and elastography have proven superior properties to evaluate tissue perfusion in various organs. We evaluated their role for functional muscle flaps positioned at the sub-skin level in facial palsy patients...
2017: Clinical Hemorheology and Microcirculation
https://www.readbyqxmd.com/read/28769506/pneumatic-retinopexy-in-rhegmatogenous-retinal-detachment
#4
R P Gupta, M Deshpande, A Bharadwaj, V K Baranwal
Existing surgical modes for retinal detachment are elaborate and extremely complex. We have treated 20 cases of rhegmatogenous retinal detachment with pneumatic retinopexy which is Iess time consuming and does not require hospitalization. After pneumatic retinopexy reattachment of retina was achieved in 15 (75%) eyes. In 2 eyes retinal reattachment was achieved after repeating intravitreal injection of sulphur hexafluoride gas. Remaining 3 eyes were secondarily treated with scleral buckle surgery. One case needed vitreoretinal surgery...
October 1997: Medical Journal, Armed Forces India
https://www.readbyqxmd.com/read/28684705/measuring-the-transition-rates-of-coalescence-events-during-double-phase-separation-in-microgravity
#5
Ana Oprisan, Yves Garrabos, Carole Lecoutre, Daniel Beysens
Phase transition is a ubiquitous phenomenon in nature, science and technology. In general, the phase separation from a homogeneous phase depends on the depth of the temperature quench into the two-phase region. Earth's gravity masks the details of phase separation phenomena, which is why experiments were performed under weightlessness. Under such conditions, the pure fluid sulphur hexafluoride (SF 6 ) near its critical point also benefits from the universality of phase separation behavior and critical slowing down of dynamics...
July 6, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28527200/contrast-enhanced-ultrasound-ceus-in-renal-imaging-at-an-interdisciplinary-ultrasound-centre-possibilities-of-dynamic-microvascularisation-and-perfusion
#6
Franz Josef Putz, Anna Erlmeier, Isabel Wiesinger, Niklas Verloh, Christian Stroszczynski, Bernhard Banas, Ernst Michael Jung
OBJECTIVE: To identify the indications for CEUS in renal imaging in an interdisciplinary ultrasound department. METHODS: 102 CEUS examinations of the kidney in 82 patients between September 2014 and July 2016 were analysed regarding the indication for ultrasound. CEUS was performed by one experienced sonographer agent after bolus injection of 1.0 up to 2.4 ml sulphur hexafluoride microbubbles using multifrequency probes with Contrast Harmonic imaging. RESULTS: CEUS of the kidney was performed in patients from 20 to 87 years...
2017: Clinical Hemorheology and Microcirculation
https://www.readbyqxmd.com/read/28333880/twenty-five-gauge-pars-plana-vitrectomy-in-complex-retinal-detachments-associated-with-giant-retinal-tear
#7
Vinod Kumar, Devesh Kumawat, Anju Bhari, Parijat Chandra
PURPOSE: To study the structural and functional outcomes of 25-gauge pars plana vitrectomy in giant retinal tear-associated retinal detachments. METHODS: Seventeen eyes of 17 patients with giant retinal tear, who underwent 25-gauge pars plana vitrectomy over a period of 15 months at a tertiary eye care center by a single surgeon, were recruited in this retrospective interventional study. RESULTS: Giant retinal tears were mostly traumatic (35...
April 2018: Retina
https://www.readbyqxmd.com/read/28145108/detection-of-liver-metastases-in-cancer-patients-with-geographic-fatty-infiltration-of-the-liver-the-added-value-of-contrast-enhanced-sonography
#8
Tommaso Vincenzo Bartolotta, Adele Taibbi, Dario Picone, Andrea Anastasi, Massimo Midiri, Roberto Lagalla
PURPOSE: The aim of this study is to assess the role of contrast-enhanced ultrasonography (CEUS) in the detection of liver metastases in cancer patients with geographic liver fatty deposition on greyscale ultrasonography (US). METHODS: Thirty-seven consecutive cancer patients (24 women and 13 men; age, 33 to 80 years; mean, 58.1 years) with geographic liver fatty deposition, but without any detectable focal liver lesion on greyscale US, underwent sulphur hexafluoride-enhanced US...
April 2017: Ultrasonography
https://www.readbyqxmd.com/read/27983598/plasma-processing-with-fluorine-chemistry-for-modification-of-surfaces-wettability
#9
Veronica Satulu, Maria Daniela Ionita, Sorin Vizireanu, Bogdana Mitu, Gheorghe Dinescu
Using plasma in conjunction with fluorinated compounds is widely encountered in material processing. We discuss several plasma techniques for surface fluorination: deposition of fluorocarbon thin films either by magnetron sputtering of polytetrafluoroethylene targets, or by plasma-assisted chemical vapor deposition using tetrafluoroethane as a precursor, and modification of carbon nanowalls by plasma treatment in a sulphur hexafluoride environment. We showed that conformal fluorinated thin films can be obtained and, according to the initial surface properties, superhydrophobic surfaces can be achieved...
December 13, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/27906983/tithonia-diversifolia-as-a-supplementary-feed-for-dairy-cows
#10
Rafael Sandin Ribeiro, Stephanie Amelia Terry, João Paulo Sacramento, Sylvia Rocha E Silveira, Cláudia Braga Pereira Bento, Elsa Fernandes da Silva, Hilário Cuquetto Mantovani, Marco Antônio Sundfeld da Gama, Luiz Gustavo Ribeiro Pereira, Thierry Ribeiro Tomich, Rogério Martins Maurício, Alexandre Vieira Chaves
The objective of this study was to examine the effects of Tithonia diversifolia as a supplementary forage on dairy cow performance and methane production. Nine lactating Holstein × Zebu dairy cows (519 ± 53.3 kg of body weight and 66 ± 13.3 d in milk) were paired by milk yield (21.3 ± 2.34 kg/d) and body weight and randomly assigned to three dietary treatments in a Latin square design with 21-d experimental periods (14 d for diet adaptation and 7 d for measurements and sample collection). The dietary treatments included the control diet consisting of fresh sugar cane plus concentrate (44:56, % of diet DM), and two treatment diets containing different levels of fresh T...
2016: PloS One
https://www.readbyqxmd.com/read/27870287/potential-of-tannin-rich-plants-leucaena-leucocephala-glyricidia-sepium-and-manihot-esculenta-to-reduce-enteric-methane-emissions-in-sheep
#11
H Archimède, M Rira, D J Barde, F Labirin, C Marie-Magdeleine, B Calif, F Periacarpin, J Fleury, Y Rochette, D P Morgavi, M Doreau
An in vivo trial was conducted in sheep to investigate the effect of three tropical tannin-rich plants (TRP) on methane emission, intake and digestibility. The TRP used were leaves of Glyricidia sepium, Leucaena leucocephala and Manihot esculenta that contained, respectively, 39, 75 and 92 g condensed tannins/kg DM. Methane was determined with the sulphur hexafluoride tracer technique. Eight rumen-cannulated sheep of two breeds (four Texel, four Blackbelly) were used in two 4 × 4 Latin square designs. Four experimental diets were tested...
December 2016: Journal of Animal Physiology and Animal Nutrition
https://www.readbyqxmd.com/read/27595913/the-effect-of-air-sf6-and-c3f8-on-immortalized-human-corneal-endothelial-cells
#12
Marina Hesse, David Kuerten, Peter Walter, Niklas Plange, Sandra Johnen, Matthias Fuest
PURPOSE: While anterior chamber air bubbles aid attachment during posterior lamellar surgery only for few days, these periods can be prolonged with gases in non-expanding concentrations. To test the effects of different gas compositions on immortalized human corneal endothelial cells (HCEC-12), we utilized Transwell inserts with semipermeable membranes as an artificial anterior chamber model. METHODS: Human corneal endothelial cells (HCEC-12) were cultured on Transwell inserts for 24 hr, then flipped, burdened and sunk with titanium rings in medium (M1), as well as filled with 2 ml of air (A), 20% sulphur hexafluoride (SF6) (S), or 12% C3F8 (C)...
June 2017: Acta Ophthalmologica
https://www.readbyqxmd.com/read/27460279/duration-of-intraocular-gases-following-vitreoretinal-surgery
#13
Andreas Kontos, James Tee, Alastair Stuart, Zaid Shalchi, Tom H Williamson
BACKGROUND: Intraocular gas tamponades are an important tool in modern vitreoretinal surgery. However, there is considerable variation in their use and perceptions amongst clinicians regarding these agents. METHODS: An electronic survey of vitreoretinal surgeons in the UK was undertaken to establish the patterns of use and surgeons' estimates of the longevity and expansion timing of gas tamponades. In addition, data were prospectively collected on the longevity of gas tamponades in 114 patients from our unit...
February 2017: Graefe's Archive for Clinical and Experimental Ophthalmology
https://www.readbyqxmd.com/read/27433201/malignant-focal-liver-lesions-at-contrast-enhanced-ultrasonography-and-magnetic-resonance-with-hepatospecific-contrast-agent
#14
M D'Onofrio, S Crosara, R De Robertis, S Canestrini, V Cantisani, G Morana, R Pozzi Mucelli
The aim of this study was to compare the diagnostic accuracy of the late phase of CEUS and the hepatobiliary phase of CE-MR with Gd-BOPTA in the characterization of focal liver lesions in terms of benignity and malignancy. A total of 147 solid focal liver lesions (38 focal nodular hyperplasias, 1 area of focal steatosis, 3 regenerative nodules, 8 adenomas, 11 cholangiocarcinomas, 36 hepatocellular carcinomas and 49 metastases) were retrospectively evaluated in a multicentre study, both with CEUS, using sulphur hexafluoride microbubbles (SonoVue, Bracco, Milan, Italy) and CE-MR, performed with Gd-BOPTA (Multihance, Bracco, Milan, Italy)...
May 2014: Ultrasound: Journal of the British Medical Ultrasound Society
https://www.readbyqxmd.com/read/27375321/evaluation-of-vitreous-substitutes-in-managing-complicated-vitreo-retinal-surgeries
#15
V S Gurunadh, A Banarji, S Patyal, A K Upadhyay, T S Ahluwalia, R P Gupta, M Bhaduria
BACKGROUND: Vitreous substitutes presently in use for intraoperative tamponade are perfluorocarbon liquids (PFCL) and for post operative tamponade are silicon oil (SO), sulphur hexafluoride (SF6) and perfluorocarbon gas (PFC). Several factors are important for a thorough understanding of each of these vitreous substitutes. The absorption or necessity for removal, indications for use (including clinical studies and special surgical methods), additives and complications of use have to be considered...
April 2010: Medical Journal, Armed Forces India
https://www.readbyqxmd.com/read/27365283/a-methodological-approach-for-quantifying-and-characterizing-the-stability-of-agitated-saline-contrast-implications-for-quantifying-intrapulmonary-shunt
#16
Heather K Hackett, Lindsey M Boulet, Paolo B Dominelli, Glen E Foster
Agitated saline contrast echocardiography is often used to determine blood flow through intrapulmonary arteriovenous anastomoses (Q̇IPAVA). We applied indicator dilution theory to time-acoustic intensity curves obtained from a bolus injection of hand-agitated saline contrast to acquire a quantitative index of contrast mass. Using this methodology and an in vitro model of the pulmonary circulation, the purpose of this study was to determine the effect of transit time and gas composition [air vs. sulphur hexafluoride (SF6)] on contrast conservation between two detection sites separated by a convoluted network of vessels...
August 1, 2016: Journal of Applied Physiology
https://www.readbyqxmd.com/read/27330393/continuous-intraoperative-oct-guided-management-of-post-deep-anterior-lamellar-keratoplasty-descemet-s-membrane-detachment
#17
Namrata Sharma, Neelima Aron, Prateek Kakkar, Jeewan S Titiyal
Continuous intraoperative optical coherence tomography (iOCT) integrated into the operating microscope is a new modification in the current operating microscope to aid in the surgical procedures involving both the anterior and the posterior segment. This helps in intraoperative planning, modification of the surgical steps if required and confirmation of the surgical endpoint in the operating room itself. iOCT was used for the successful management of descemet's membrane detachment (DMD) following deep anterior lamellar keratoplasty (DALK) with intracameral injection of 20% Sulphur hexafluoride...
April 2016: Saudi Journal of Ophthalmology: Official Journal of the Saudi Ophthalmological Society
https://www.readbyqxmd.com/read/27104797/effects-of-boundary-layer-separation-controllers-on-a-desktop-fume-hood
#18
Rong Fung Huang, Jia-Kun Chen, Ching Min Hsu, Shuo-Fu Hung
A desktop fume hood installed with an innovative design of flow boundary-layer separation controllers on the leading edges of the side plates, work surface, and corners was developed and characterized for its flow and containment leakage characteristics. The geometric features of the developed desktop fume hood included a rearward offset suction slot, two side plates, two side-plate boundary-layer separation controllers on the leading edges of the side plates, a slanted surface on the leading edge of the work surface, and two small triangular plates on the upper left and right corners of the hood face...
October 2, 2016: Journal of Occupational and Environmental Hygiene
https://www.readbyqxmd.com/read/26999939/-managment-of-subretinal-heamorrhages-within-the-macular-area-using-intravitreal-injections-of-recombined-tissue-plasminogen-activator-sulphur-hexafluoride-and-ranihizumab-preliminary-report
#19
Joanna Miniewicz, Agnieszka Kubicka-Trząska, Izabella Karska-Basta, Boźena Romanowska-Dixon
Submacular hemorrhages cause serious vision impairment. Patient observation, waiting for the spontaneous blood reabsorption and resolution of the haemorrhage leads to the severe damage to retinal tissue as a result of scar formation. The paper presents 7 cases of patients with submacular haemorrhages treated with intravitreal injections of recombined tissue plasminogen activator (rtPA) and sulphur hexafluoride (SFG). In 4 cases, the haemorrhage was secondary to AMD, in two cases to trauma, and it was idiopathic in one case...
2015: Klinika Oczna
https://www.readbyqxmd.com/read/26825260/retention-efficacy-and-release-of-radioiodine-in-fume-hoods
#20
K Schomäcker, T Fischer, B Zimmermanns, J Bregulla, F Sudbrock, O Prante, A Drzezga
Procedures to determine the release of hazardous gaseous substances including radioactive iodine are covered by different norms such as the European standard EN 14175 and the German national standard DIN 25466. The detection of sulphur hexafluoride (SF6 ) is required to comply with the prescribed methodology. The detection limit of this test is 4.5·10-7  mol/m3 in exhaust air. This detection limit would represent a very high activity in the region of 0.27 TBq/m3 leading to an unacceptable risk. We therefore developed a test using a filter system, consisting of a combination of filters capable of separating various chemical forms of airborne radioiodine...
January 2017: Journal of Environmental Radioactivity
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