Analyzing the dependence of oxygen incorporation current density on overpotential and oxygen partial pressure in mixed conducting oxide electrodes.

Science.gov (United States)

Guan, Zixuan; Chen, Di; Chueh, William C

2017-08-30

The oxygen incorporation reaction, which involves the transformation of an oxygen gas molecule to two lattice oxygen ions in a mixed ionic and electronic conducting solid, is a ubiquitous and fundamental reaction in solid-state electrochemistry. To understand the reaction pathway and to identify the rate-determining step, near-equilibrium measurements have been employed to quantify the exchange coefficients as a function of oxygen partial pressure and temperature. However, because the exchange coefficient contains contributions from both forward and reverse reaction rate constants and depends on both oxygen partial pressure and oxygen fugacity in the solid, unique and definitive mechanistic assessment has been challenging. In this work, we derive a current density equation as a function of both oxygen partial pressure and overpotential, and consider both near and far from equilibrium limits. Rather than considering specific reaction pathways, we generalize the multi-step oxygen incorporation reaction into the rate-determining step, preceding and following quasi-equilibrium steps, and consider the number of oxygen ions and electrons involved in each. By evaluating the dependence of current density on oxygen partial pressure and overpotential separately, one obtains the reaction orders for oxygen gas molecules and for solid-state species in the electrode. We simulated the oxygen incorporation current density-overpotential curves for praseodymium-doped ceria for various candidate rate-determining steps. This work highlights a promising method for studying the exchange kinetics far away from equilibrium.

Real-Time Monitoring of Singlet Oxygen and Oxygen Partial Pressure During the Deep Photodynamic Therapy In Vitro.

Science.gov (United States)

Li, Weitao; Huang, Dong; Zhang, Yan; Liu, Yangyang; Gu, Yueqing; Qian, Zhiyu

2016-09-01

Photodynamic therapy (PDT) is an effective noninvasive method for the tumor treatment. The major challenge in current PDT research is how to quantitatively evaluate therapy effects. To our best knowledge, this is the first time to combine multi-parameter detection methods in PDT. More specifically, we have developed a set of system, including the high-sensitivity measurement of singlet oxygen, oxygen partial pressure and fluorescence image. In this paper, the detection ability of the system was validated by the different concentrations of carbon quantum dots. Moreover, the correlation between singlet oxygen and oxygen partial pressure with laser irradiation was observed. Then, the system could detect the signal up to 0.5 cm tissue depth with 660 nm irradiation and 1 cm tissue depth with 980 nm irradiation by using up-conversion nanoparticles during PDT in vitro. Furthermore, we obtained the relationship among concentration of singlet oxygen, oxygen partial pressure and tumor cell viability under certain conditions. The results indicate that the multi-parameter detection system is a promising asset to evaluate the deep tumor therapy during PDT. Moreover, the system might be potentially used for the further study in biology and molecular imaging.

Design and control of the oxygen partial pressure of UO2 in TGA using the humidification system

International Nuclear Information System (INIS)

Lee, S.; Knight, T.W.; Roberts, E.

2015-01-01

Highlights: • We focus on measurement of oxygen partial pressure and change of O/M ratio under specific conditions produced by the humidification system. • This shows that the humidification system is stable, accurate, and reliable enough to be used for experiments of the oxygen partial pressure measurement for the oxide fuels. • The humidification system has benefits of easy control and flexibility for producing various oxygen partial pressures with fixed hydrogen gas flow rate. - Abstract: The oxygen to uranium (O/U) ratio of UO 2±x is determined by the oxygen content of the sample and is affected by oxygen partial pressure (pO 2 ) of the surrounding gas. Oxygen partial pressure is controllable by several methods. A common method to produce different oxygen partial pressures is the use of equilibria of different reaction gases. There are two common methods: H 2 O/H 2 reaction and CO 2 /CO reaction. In this work, H 2 O/H 2 reaction using a humidifier was employed and investigated to ensure that this humidification system for oxygen partial pressure is stable and accurate for use in Thermogravimetric Analyzer (TGA) experiments with UO 2 . This approach has the further advantage of flexibility to make a wide range of oxygen partial pressure with fixed hydrogen gas flow rate only by varying temperature of water in the humidifier. The whole system for experiments was constructed and includes the humidification system, TGA, oxygen analyzer, and gas flow controller. Uranium dioxide (UO 2 ) samples were used for experiments and oxygen partial pressure was measured at the equilibrium state of stoichiometric UO 2.0 . Oxygen partial pressures produced by humidification (wet gas) system were compared to the approach using mixed dry gases (without humidification system) to demonstrate that the humidification system provides for more stable and accurate oxygen partial pressure control. This work provides the design, method, and analysis of a humidification system for

In vivo integrated photoacoustic and confocal microscopy of hemoglobin oxygen saturation and oxygen partial pressure.

Science.gov (United States)

Wang, Yu; Hu, Song; Maslov, Konstantin; Zhang, Yu; Xia, Younan; Wang, Lihong V

2011-04-01

We developed dual-modality microscope integrating photoacoustic microscopy (PAM) and fluorescence confocal microscopy (FCM) to noninvasively image hemoglobin oxygen saturation (sO₂) and oxygen partial pressure (pO₂) in vivo in single blood vessels with high spatial resolution. While PAM measures sO₂ by imaging hemoglobin optical absorption at two wavelengths, FCM quantifies pO₂ using phosphorescence quenching. The variations of sO₂ and pO₂ values in multiple orders of vessel branches under hyperoxic (100% oxygen) and normoxic (21% oxygen) conditions correlate well with the oxygen-hemoglobin dissociation curve. In addition, the total concentration of hemoglobin is imaged by PAM at an isosbestic wavelength.

Calibration Of Partial-Pressure-Of-Oxygen Sensors

Science.gov (United States)

Yount, David W.; Heronimus, Kevin

1995-01-01

Report and analysis of, and discussion of improvements in, procedure for calibrating partial-pressure-of-oxygen sensors to satisfy Spacelab calibration requirements released. Sensors exhibit fast drift, which results in short calibration period not suitable for Spacelab. By assessing complete process of determining total drift range available, calibration procedure modified to eliminate errors and still satisfy requirements without compromising integrity of system.

Oxygen supply in aquatic ectotherms: partial pressure and solubility together explain biodiversity and size patterns.

Science.gov (United States)

Verberk, Wilco C E P; Bilton, David T; Calosi, Piero; Spicer, John I

2011-08-01

Aquatic ectotherms face the continuous challenge of capturing sufficient oxygen from their environment as the diffusion rate of oxygen in water is 3 x 10(5) times lower than in air. Despite the recognized importance of oxygen in shaping aquatic communities, consensus on what drives environmental oxygen availability is lacking. Physiologists emphasize oxygen partial pressure, while ecologists emphasize oxygen solubility, traditionally expressing oxygen in terms of concentrations. To resolve the question of whether partial pressure or solubility limits oxygen supply in nature, we return to first principles and derive an index of oxygen supply from Fick's classic first law of diffusion. This oxygen supply index (OSI) incorporates both partial pressure and solubility. Our OSI successfully explains published patterns in body size and species across environmental clines linked to differences in oxygen partial pressure (altitude, organic pollution) or oxygen solubility (temperature and salinity). Moreover, the OSI was more accurately and consistently related to these ecological patterns than other measures of oxygen (oxygen saturation, dissolved oxygen concentration, biochemical oxygen demand concentrations) and similarly outperformed temperature and altitude, which covaried with these environmental clines. Intriguingly, by incorporating gas diffusion rates, it becomes clear that actually more oxygen is available to an organism in warmer habitats where lower oxygen concentrations would suggest the reverse. Under our model, the observed reductions in aerobic performance in warmer habitats do not arise from lower oxygen concentrations, but instead through organismal oxygen demand exceeding supply. This reappraisal of how organismal thermal physiology and oxygen demands together shape aerobic performance in aquatic ectotherms and the new insight of how these components change with temperature have broad implications for predicting the responses of aquatic communities to

[Effects of gap junction blocking on the oxygen partial pressure in acupoints of the bladder meridian].

Science.gov (United States)

Wang, Qi; Yu, Wei-Chang; Jiang, Hong-Zhi; Chen, Sheng-Li; Zhang, Ming-Min; Kong, E-Sheng; Huang, Guang-Ying

2010-12-01

To explore the relation between gap junction and meridian phenomenon. The oxygen partial pressure in acupoints [see text for formula] and in their corresponding non-acupoints of the Bladder Meridian was observed with the needle-type tissue oxygen tension sensor in the gap junction blocking goats by 1-Heptanol injection and the Connexin 43 (Cx43) gene knockout mice. (1) The oxygen partial pressure in acupoints of Bladder Meridian on goats was higher than that in non-acupoints after 1-Heptanol injection with significant differences between them (both P oxygen partial pressure in acupoints of Bladder Meridian on goats increased significantly after injecting 1-Heptanol as compare with that either injecting normal saline or injecting nothing with significant differences between them (all P oxygen partial pressure in acupoints of the Bladder Meridian was significantly higher than that in the non-acupoint controls in Cx43 wild type (WT) mice (all P oxygen partial pressure between acupoints and non-acupoint controls showed no significant differences (all P > 0.05). (4) In acupoints, the oxygen partial pressure in Cx43 WT mice was significantly higher than that in Cx43 HT mice (all P 0.05). Gap junction maybe the essential factor in signal transduction of acupuncture.

Effect of Electroacupuncture on Transcutaneous Oxygen Partial Pressure During Hyperbaric Oxygen Therapy in Healthy Individuals.

Science.gov (United States)

Qu, Lan; Ye, Yong; Li, Chunfeng; Gao, Guangkai

2015-01-01

The goal of hyperbaric oxygen therapy (HBOT) is to increase the oxygen (O₂) supply to the body significantly. Because of the toxic side effects and complications of hyperbaric oxygen (HBO₂), the environmental pressure and treatment time must be restricted. The research team hypothesized that other therapies administered during HBOT could safely improve the value of the arterial oxygen partial pressure (PaO₂) during HBOT and improve its therapeutic effect. The study intended to investigate whether electroacupuncture (EA) while receiving HBOT had a greater effect for healthy individuals than HBOT or EA alone or EA combined with normobaric pure oxygen (pure O₂). The research team designed a randomized, controlled trial. The study was performed in the Department of Hyperbaric Medicine at the No. 401 Hospital of the People's Liberation Army in Qingdao, China. A total of 81 volunteers were recruited. After thorough physical examination and laboratory testing, 21 volunteers were excluded from the study. Participants included 60 healthy volunteers. Participants were randomly assigned to 1 of 4 groups of 15 participants each: (1) an HBOT group, (2) an EA group, (3) an EA During HBOT group, and (4) an EA Combined With Pure O₂group. Because at the current technology level a blood gas analyzer cannot test PaO₂during HBOT, transcutaneous oxygen partial pressure (PtcO₂) of the participants was tested instead. Before, during, and after EA, variations in PtcO₂were monitored in each group. For the EA During HBOT group, (1) the increase in PtcO₂during EA was significantly greater than that observed for the other 3 groups (P > .05). The EA During HBOT method provided improvements in the efficacy, safety, and tolerability of HBOT, and the study's results partially demonstrated the accuracy of the research team's hypothesis that EA therapy applied during HBOT could safely improve the value of PtcO₂(PaO₂) during HBOT and produce a greater therapeutic effect.

Association between administered oxygen, arterial partial oxygen pressure and mortality in mechanically ventilated intensive care unit patients

NARCIS (Netherlands)

de Jonge, Evert; Peelen, Linda; Keijzers, Peter J.; Joore, Hans; de Lange, Dylan; van der Voort, Peter Hj; Bosman, Robert J.; de Waal, Ruud Al; Wesselink, Ronald; de Keizer, Nicolette F.

2008-01-01

Introduction The aim of this study was to investigate whether in-hospital mortality was associated with the administered fraction of oxygen in inspired air (FiO(2)) and achieved arterial partial pressure of oxygen (PaO2). Methods This was a retrospective, observational study on data from the first

Association between administered oxygen, arterial partial oxygen pressure and mortality in mechanically ventilated intensive care unit patients

NARCIS (Netherlands)

de Jonge, Evert; Peelen, Linda; Keijzers, Peter J.; Joore, Hans; de Lange, Dylan; van der Voort, Peter H. J.; Bosman, Robert J.; de Waal, Ruud A. L.; Wesselink, Ronald; de Keizer, Nicolette F.

2008-01-01

Introduction The aim of this study was to investigate whether in-hospital mortality was associated with the administered fraction of oxygen in inspired air (FiO(2)) and achieved arterial partial pressure of oxygen (PaO(2)). Methods This was a retrospective, observational study on data from the first

Oxidation of C/SiC Composites at Reduced Oxygen Partial Pressures

Science.gov (United States)

Opila, Elizabeth J.; Serra, Jessica

2009-01-01

Carbon-fiber reinforced SiC (C/SiC) composites are proposed for leading edge applications of hypersonic vehicles due to the superior strength of carbon fibers at high temperatures (greater than 1500 C). However, the vulnerability of the carbon fibers in C/SiC to oxidation over a wide range of temperatures remains a problem. Previous oxidation studies of C/SiC have mainly been conducted in air or oxygen, so that the oxidation behavior of C/SiC at reduced oxygen partial pressures of the hypersonic flight regime are less well understood. In this study, both carbon fibers and C/SiC composites were oxidized over a wide range of temperatures and oxygen partial pressures to facilitate the understanding and modeling of C/SiC oxidation kinetics for hypersonic flight conditions.

[Effect of oxygen tubing connection site on percutaneous oxygen partial pressure and percutaneous carbon dioxide partial pressure in patients with chronic obstructive pulmonary disease during noninvasive positive pressure ventilation].

Science.gov (United States)

Mi, S; Zhang, L M

2017-04-12

Objective: We evaluated the effects of administering oxygen through nasal catheters inside the mask or through the mask on percutaneous oxygen partial pressure (PcO(2))and percutaneous carbon dioxide partial pressure (PcCO(2)) during noninvasive positive pressure ventilation (NPPV) to find a better way of administering oxygen, which could increase PcO(2) by increasing the inspired oxygen concentration. Methods: Ten healthy volunteers and 9 patients with chronic obstructive pulmonary disease complicated by type Ⅱ respiratory failure were included in this study. Oxygen was administered through a nasal catheter inside the mask or through the mask (oxygen flow was 3 and 5 L/min) during NPPV. PcO(2) and PcCO(2) were measured to evaluate the effects of administering oxygen through a nasal catheter inside the mask or through the mask, indirectly reflecting the effects of administering oxygen through nasal catheter inside the mask or through the mask on inspired oxygen concentration. Results: Compared to administering oxygen through the mask during NPPV, elevated PcO(2) was measured in administering oxygen through the nasal catheter inside the mask, and the differences were statistically significant ( P 0.05). Conclusion: Administering oxygen through a nasal catheter inside the mask during NPPV increased PcO(2) by increasing the inspired oxygen concentration but did not increase PcCO(2). This method of administering oxygen could conserve oxygen and be suitable for family NPPV. Our results also provided theoretical basis for the development of new masks.

Oxygen partial pressure effects on the RF sputtered p-type NiO hydrogen gas sensors

Science.gov (United States)

Turgut, Erdal; Çoban, Ömer; Sarıtaş, Sevda; Tüzemen, Sebahattin; Yıldırım, Muhammet; Gür, Emre

2018-03-01

NiO thin films were grown by Radio Frequency (RF) Magnetron Sputtering method under different oxygen partial pressures, which are 0.6 mTorr, 1.3 mTorr and 2.0 mTorr. The effects of oxygen partial pressures on the thin films were analyzed through Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Hall measurements. The change in the surface morphology of the thin films has been observed with the SEM and AFM measurements. While nano-pyramids have been obtained on the thin film grown at the lowest oxygen partial pressure, the spherical granules lower than 60 nm in size has been observed for the samples grown at higher oxygen partial pressures. The shift in the dominant XRD peak is realized to the lower two theta angle with increasing the oxygen partial pressures. XPS measurements showed that the Ni2p peak involves satellite peaks and two oxidation states of Ni, Ni2+ and Ni3+, have been existed together with the corresponding splitting in O1s spectrum. P-type conductivity of the grown NiO thin films are confirmed by the Hall measurements with concentrations on the order of 1013 holes/cm-3. Gas sensor measurements revealed minimum of 10% response to the 10 ppm H2 level. Enhanced responsivity of the gas sensor devices of NiO thin films is shown as the oxygen partial pressure increases.

Effect of substrate temperature and oxygen partial pressure on RF sputtered NiO thin films

Science.gov (United States)

Cheemadan, Saheer; Santhosh Kumar, M. C.

2018-04-01

Nickel oxide (NiO) thin films were deposited by RF sputtering process and the physical properties were investigated for varying substrate temperatures and oxygen partial pressure. The variation of the crystallographic orientation and microstructure of the NiO thin films with an increase in substrate temperature were studied. It was observed that NiO thin films deposited at 350 °C shows relatively good crystalline characteristics with a preferential orientation along (111) plane. With the optimum substrate temperature of 350 °C, the NiO thin films were deposited under various oxygen partial pressures at the same experimental conditions. The structural, optical and electrical properties of NiO thin films under varying oxygen partial pressure of 10%–50% were investigated. From XRD it is clear that the films prepared in the pure argon atmosphere were amorphous while the films in oxygen partial pressure exhibited polycrystalline NiO phase. SEM and AFM investigations unveil that the higher substrate temperature improves the microstructure of the thin films. It is revealed that the NiO thin films deposited at oxygen partial pressure of 40% and a substrate temperature of 350 °C, showed higher electrical conductivity with p-type characteristics.

Classifying Acute Respiratory Distress Syndrome Severity: Correcting the Arterial Oxygen Partial Pressure to Fractional Inspired Oxygen at Altitude.

Science.gov (United States)

Pérez-Padilla, Rogelio; Hernández-Cárdenas, Carmen Margarita; Lugo-Goytia, Gustavo

2016-01-01

In the well-known Berlin definition of acute respiratory distress syndrome (ARDS), there is a recommended adjustment for arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FIO2) at altitude, but without a reference as to how it was derived.

Potential hydrogen and oxygen partial pressures in legacy plutonium oxide packages at Oak Ridge

Energy Technology Data Exchange (ETDEWEB)

Veirs, Douglas K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2014-07-07

An approach to estimate the maximum hydrogen and oxygen partial pressures within sealed containers is described and applied to a set of packages containing high-purity plutonium dioxide. The approach uses experimentally determined maximum hydrogen and oxygen partial pressures and scales the experimentally determined pressures to the relevant packaged material properties. The important material properties are the specific wattage and specific surface area (SSA). Important results from the experimental determination of maximum partial pressures are (1) the ratio of hydrogen to oxygen is stoichiometric, and (2) the maximum pressures increase with increasing initial rates of production. The material properties that influence the rates are the material specific wattage and the SSA. The unusual properties of these materials, high specific wattage and high SSA, result in higher predicted maximum pressures than typical plutonium dioxide in storage. The pressures are well within the deflagration range for mixtures of hydrogen and oxygen.

Partial pressures of oxygen, phosphorus and fluorine in some lunar lavas

Science.gov (United States)

Nash, W. P.; Hausel, W. D.

1973-01-01

Lunar sample 14310 is a feldspar-rich basalt which shows no evidence of shock deformation or recrystallization. Pyroxenes include Mg-rich orthopyroxene, pigeonite and augite; pyroxferroite occurs in the interstitial residuum. Plagioclase feldspars are zoned from An(96) to An(67), and variations in feldspar compositions do not necessarily indicate loss of Na during eruption of the lava. Opaque phases include ilmenite, ulvospinel, metallic iron, troilite, and schreibersite. Both whitlockite and apatite are present, and the interstitial residua contain baddeleyite, tranquillityite and barium-rich sanidine. Theoretical calculations provide estimates of partial pressures of oxygen, phosphorus, and fluorine in lunar magmas. In general, partial pressures of oxygen are restricted by the limiting assemblages of iron-wuestite and ilmenite-iron-rutile; phosphorus partial pressures are higher in lunar magmas than in terrestrial lavas. The occurrence of whitlockite indicates significantly lower fugacities of fluorine in lunar magmas than in terrestrial magmas.

Viscoelastic properties of doped-ceria under reduced oxygen partial pressure

DEFF Research Database (Denmark)

Teocoli, Francesca; Esposito, Vincenzo

2014-01-01

The viscoelastic properties of gadolinium-doped ceria (CGO) powder compacts are characterized during sintering and cooling under reduced oxygen partial pressure and compared with conventional sintering in air. Highly defective doped ceria in reducing conditions shows peculiar viscoelastic...

Case Report Pneumomediastinum and Subcutaneous Emphysema ...

African Journals Online (AJOL)

oxygen may enhance faster absorption of air from extra-pulmonary tissues while needle aspiration and/ or surgical decompression may be useful if mediastinal structures are compressed [2,9,]. Conclusion. Extra-pulmonary extravasations of air manifested as subcutaneous emphysema and pneumomediastinum.

Effect of oxygen partial pressure on oxidation of Mo-metal

Science.gov (United States)

Sharma, Rabindar Kumar; Kumar, Prabhat; Singh, Megha; Gopal, Pawar; Reddy, G. B.

2018-05-01

This report explains the effect of oxygen partial pressure (PO2 ) on oxidation of Mo-metal in oxygen plasma. XRD results indulge that oxide layers formed on Mo-surfaces at different oxygen partial pressures have two different oxide phases (i.e. orthorhombic MoO3 and monoclinic Mo8O23). Intense XRD peaks at high pressure (i.e. 2.0×10-1 Torr) points out the formation of thick oxide layer on Mo-surface due to presence of large oxygen species in chamber and less oxide volatilization. Whereas, at low PO2 (6.5×10-2 and 7.5×10-2 Torr.) the reduced peak strength is owing to high oxide volatilization rate. SEM micrographs and thickness measurements also support XRD results and confirm that the optimum -2value of PO2 to deposited thicker and uniform oxide film on glass substrate is 7.5×10-2 Torr through plasma assistedoxidation process. Further to study the compositional properties, EDX of the sample M2 (the best sample) is carried out, which confirms that the stoichiometric ratio is less than 3 (i.e. 2.88). Less stoichiometric ratio again confirms the presence of sub oxides in oxide layers on Mo metal as evidenced by XRD results. All the observed results are well in consonance with each other.

In vivo near real time imaging of oxygen partial pressures in the glass catfish (Kryptopterus bichirris)

DEFF Research Database (Denmark)

Steffensen, John Fleng

2012-01-01

of the transparent glass catfish (Kryptopterus bichirris), it is possible to measure near realtime oxygen partial pressure in vivo. We used a commercially-available digital single-lens reflex camera mounted with an optical long pass filter (II = 490 nm) and excited the phosphorescent dye in the microspheres inside...... the fish with externally-mounted blue light emitting diodes (lip = 470 nm) to image the oxygen partial pressure. This method makes it possible to investigate oxygen partial pressures in the vascular system and different tissues of fish without having to insert any probes into the animal. After injection...

Oxygen partial pressure effects on the magnetron sputtered WO3 films

International Nuclear Information System (INIS)

Muğlu, G Merhan; Gür, E

2016-01-01

Electrochromism is changing color of a substance in response to the applied an external electric field and the phenomenon is reversible. WO 3 is very attractive material due to its electrochromic properties as well as it is also attractive for many different applications such as gas sensors, phosphorous screen, textile, glass industry. In this study, it is aimed to provide optimization of the optical and structural characteristics of WO 3 by changing the growth parameters mainly the oxygen partial pressure. The partial pressure of oxygen was changed with increments of 0.7 mTorr. For the analysis, X-ray Diffraction (XRD), absorption, Raman spectroscopy measurements were used. When O 2 gas increased, peaks belong to the WO 3 was observed in XRD patterns at the 2 theta angles of 23.0, 11.0, 23.5 and 28.5 angles corresponding to the (002), (020) and (220) planes, respectively. This shows that there is a significant effect of increasing O 2 partial pressure in the formation of WO 3 films. The bandgap energy of the WO 3 thin films are found to be around 3.0 eV. Raman measurements showed vibrational modes of W-O-W stretching and bending modes which shows small shifts depending on the partial pressures of the O 2 . Obtained results indicated that better crystal structure is obtained with higher O 2 gas partial pressure. (paper)

SrRuO3 thin films grown on MgO substrates at different oxygen partial pressures

KAUST Repository

Zou, Bin

2013-01-08

A comprehensive study of SrRuO3 thin films growth on (001) MgO substrates by pulsed laser deposition in a wide oxygen pressure range from 10 to 300 mTorr was carried out. The experimental results showed a correlation between the lattice constants, resistivity, and oxygen partial pressures used. Ru deficiency detected only in films deposited at lower oxygen pressures (<50 mTorr), resulted in an elongation of the in-plane and out-of-plane lattice constants and an increase in the film resistivity. When deposited with oxygen partial pressure of 50 mTorr, SrRuO3 films had lattice parameters matching those of bulk SrRuO3 material and exhibited room temperature resistivity of 320 μΩ·cm. The resistivity of SrRuO 3/MgO films decreased with increasing oxygen partial pressure. Copyright © 2013 Materials Research Society.

Oxygen partial pressure dependence of electrical conductivity in γ'-Bi2MoO6

International Nuclear Information System (INIS)

Vera, C.M.C.; Aragon, R.

2008-01-01

The electrical conductivity of γ'-Bi 2 MoO 6 was surveyed between 450 and 750 deg. C as a function of oxygen partial pressure, in the range 0.01-1 atm. A -1/6 power law dependence, consistent with a Frenkel defect model of doubly ionized oxygen vacancies and interstitials, is evidence for an n-type semiconductive component, with an optical band gap of 2.9 eV. The absence of this dependence is used to map the onset of dominant ionic conduction. - Graphical abstract: Temporal dependence of electrical conductivity at 500 deg. C for γ'-Bi 2 MoO 6 at controlled partial pressures of oxygen

Growth of the microalgae Neochloris oleoabundans at high partial oxygen pressures and sub-saturating light intensity

NARCIS (Netherlands)

Sousa, C.A.; Winter, de L.; Janssen, M.G.J.; Vermue, M.H.; Wijffels, R.H.

2012-01-01

The effect of partial oxygen pressure on growth of Neochloris oleoabundans was studied at sub-saturating light intensity in a fully-controlled stirred tank photobioreactor. At the three partial oxygen pressures tested (PO2=0.24; 0.63; 0.84 bar), the specific growth rate was 1.38; 1.36 and 1.06

The influence of the oxygen partial pressure on the quasi-ternary system Cr-Mn-Ti-oxide

International Nuclear Information System (INIS)

Garcia-Rosales, C.; Schulze, H.A.; Naoumidis, A.; Nickel, H.

1991-05-01

The passivation layers formed by the oxidizing corrosion of high temperature alloys consist primarily of oxides and mixed oxides of the elements chromium, manganese and titanium. For a reproducible formation and characterization of such oxide layers it is necessary to know the phase equilibria of these oxide systems at temperature and oxygen partial pressure conditions which will be relevant during their application. For the investigation of the quasi-ternary system Cr-Mn-Ti-oxide, oxide powders were prepared and annealed at 1000deg C under different oxygen partial pressures ranging from 0.21 bar to 10 -21 bar. Phase identification and determination of lattice parameter using X-ray diffraction analysis as well as the direct measurement of phase boundaries as a function of oxygen partial pressure using the emf-methode were carried out for these investigations. In the quasi-ternary system Cr-Mn-Ti-oxide the spinels play a decisive role in the oxigen partial pressure range examined. The spinel MnCr 2 O 4 may be regarded as the most significant compound. Part of the chronium can be replaced by trivalent manganese at high oxygen partial pressures and by trivalent titanium at low pressures, and the formation of a solid solution with the spinel Mn 2 TiO 4 is possible in all cases. In this way a coherent single-phase spinel region is observed which extends over the entire oxygen partial pressure range form 0.21 bar to 10 -21 bar examined at 1000deg C. (orig.) [de

Evaluation of Nd:YAG laser on partial oxygen saturation of pulpal blood in anterior hypersensitive teeth.

Science.gov (United States)

Birang, Reza; Kaviani, Naser; Mohammadpour, Mehdi; Abed, Ahmad Moghareh; Gutknecht, Norbert; Mir, Maziar

2008-07-01

Dentine hypersensitivity has of long been known to be a common clinical problem in dental practices. Lasers have recently come to play a prominent role in the treatment of this disorder. They might, however, cause dental pulp damage. This study was conducted to evaluate the effect of Nd:yttrium-aluminum-garnet (YAG) laser on partial oxygen saturation of pulpal blood in sensitive anterior teeth. In this clinical trial, 65 hypersensitive teeth were selected and randomly allocated to two groups. The study group involved Nd:YAG laser treatment, while no treatment was employed for the control group. Using a pulse oximetry system, evaluations were preformed of the partial oxygen saturation in the pulpal blood before, immediately after, 1 week after, and 1 month after the treatment. The results were analyzed using the SPSS software and repeated-measures analysis of variance and paired-samples t tests. The mean partial oxygen saturation of the blood was found to be 85.4% in the study group, which was not significantly different from that of the control group. No significant differences were observed in the control group between the means obtained from pretreatment and post-treatment intervals (P > 0.05). The Post-treatment partial oxygen saturation mean rose to 89.3% (P = 0.001) and remained constant throughout the following week after it. However, no significant differences were found between the pretreatment partial oxygen saturation mean and the same measurement 1 month after treatment (P = 0.702). Nd:YAG laser therapy for dentine desensitization of anterior teeth caused no persistent changes in the partial oxygen saturation of pulpal blood. It may, therefore, be concluded that the diffusion of heat induced by the Nd:YAG laser into the pulp within the limit of the desensitization parameters cause no irreversible damages in the dental pulp.

Oxygen binding to partially nitrosylated hemoglobin.

Science.gov (United States)

Fago, Angela; Crumbliss, Alvin L; Hendrich, Michael P; Pearce, Linda L; Peterson, Jim; Henkens, Robert; Bonaventura, Celia

2013-09-01

Reactions of nitric oxide (NO) with hemoglobin (Hb) are important elements in protection against nitrosative damage. NO in the vasculature is depleted by the oxidative reaction with oxy Hb or by binding to deoxy Hb to generate partially nitrosylated Hb (Hb-NO). Many aspects of the formation and persistence of Hb-NO are yet to be clarified. In this study, we used a combination of EPR and visible absorption spectroscopy to investigate the interactions of partially nitrosylated Hb with O2. Partially nitrosylated Hb samples had predominantly hexacoordinate NO-heme geometry and resisted oxidation when exposed to O2 in the absence of anionic allosteric effectors. Faster oxidation occurred in the presence of 2,3-diphosphoglycerate (DPG) or inositol hexaphosphate (IHP), where the NO-heme derivatives had higher levels of pentacoordinate heme geometry. The anion-dependence of the NO-heme geometry also affected O2 binding equilibria. O2-binding curves of partially nitrosylated Hb in the absence of anions were left-shifted at low saturations, indicating destabilization of the low O2 affinity T-state of the Hb by increasing percentages of NO-heme, much as occurs with increasing levels of CO-heme. Samples containing IHP showed small decreases in O2 affinity, indicating shifts toward the low-affinity T-state and formation of inert α-NO/β-met tetramers. Most remarkably, O2-equilibria in the presence of the physiological effector DPG were essentially unchanged by up to 30% NO-heme in the samples. As will be discussed, under physiological conditions the interactions of Hb with NO provide protection against nitrosative damage without impairing O2 transport by Hb's unoccupied heme sites. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Proteins. Copyright © 2013 Elsevier B.V. All rights reserved.

Does intraoperative low arterial partial pressure of oxygen increase the risk of surgical site infection following emergency exploratory laparotomy in horses?

Science.gov (United States)

Costa-Farré, Cristina; Prades, Marta; Ribera, Thaïs; Valero, Oliver; Taurà, Pilar

2014-04-01

Decreased tissue oxygenation is a critical factor in the development of wound infection as neutrophil mediated oxidative killing is an essential mechanism against surgical pathogens. The objective of this prospective case series was to assess the impact of intraoperative arterial partial pressure of oxygen (PaO2) on surgical site infection (SSI) in horses undergoing emergency exploratory laparotomy for acute gastrointestinal disease. The anaesthetic and antibiotic protocol was standardised. Demographic data, surgical potential risk factors and PaO2, obtained 1h after induction of anaesthesia were recorded. Surgical wounds were assessed daily for infection during hospitalisation and follow up information was obtained after discharge. A total of 84 adult horses were included. SSI developed in 34 (40.4%) horses. Multivariate logistic regression showed that PaO2, anaesthetic time and subcutaneous suture material were predictors of SSI (AUC=0.76, sensitivity=71%, specificity=65%). The use of polyglycolic acid sutures increased the risk and horses with a PaO2 value 2h had the highest risk of developing SSI (OR=9.01; 95% CI 2.28-35.64). The results of this study confirm the hypothesis that low intraoperative PaO2 contributes to the development of SSI following colic surgery. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of oxygen partial pressure on defect concentrations and on oxygen diffusion in UO2+x

International Nuclear Information System (INIS)

Pizzi, Elisabetta

2013-01-01

The hyper-stoichiometric uranium dioxide (UO 2+x ) is stable over a wide range of temperature and compositions. Such variations of composition and the eventual presence of doping elements or impurities lead to a variation of anionic and electronic defect concentrations. Moreover, many properties of this material are affected by its composition modifications, in particular their atomic transport properties. Firstly we developed a point defect model to evaluate the dependence of the electronic and oxygen defect concentrations upon temperature, equilibrium oxygen partial pressure and impurity content. The physical constants of the model, in particular the equilibrium constants of the defect formation reactions were determined from deviation from stoichiometry and electrical conductivity measurements of literature. This work enabled us to interpret our measures of conductivity, oxygen chemical and self- diffusion coefficients. From a quantitative standpoint, the analysis of our experimental results allows to evaluate the oxygen interstitial diffusion coefficient but also its formation energy. Moreover, an estimate of oxygen di-interstitial formation energy is also provided. Presence of oxygen clusters leads oxygen self- and chemical diffusion to decrease. X-ray Absorption Spectroscopy characterization shows the presence of the same defect in the entire deviation from stoichiometry studied, confirming the approach used to develop the model. (author) [fr

Subcutaneous and Intramuscular Hemodynamics and Oxygenation After Cold-Spray Application as Monitored by Near-Infrared Spectroscopy

Science.gov (United States)

Shadgan, Babak; Pakravan, Amir H.; Hoens, Alison; Reid, W. Darlene

2015-01-01

Context Vapocoolant spray, commonly known as cold spray (CS), is a cryotherapy modality used in sports medicine, athletic training, and rehabilitation settings. Proposed physiologic effects of cryotherapy modalities include reductions in tissue blood flow, oxygenation, and cell metabolism in addition to attenuation of pain perception attributed to reduced superficial nerve conduction velocity. Objective To examine the effects of CS on subcutaneous and intramuscular blood flow and oxygenation on the thigh muscle using near-infrared spectroscopy, an optical method to monitor changes in tissue oxygenated (O2Hb), deoxygenated (HHb), and total (tHb) hemoglobin. Design Cross-sectional study. Setting Muscle Biophysics Laboratory. Patients or Other Participants Participants were 13 healthy adults (8 men, 5 women; age = 37.4 ± 6 years, body mass index = 27.4 ± 2.6, adipose tissue thickness = 7.2 ± 1.8 mm). Intervention(s) Conventional CS was applied to the vastus medialis muscles. Main Outcome Measure(s) Changes in chromophore concentrations of O2Hb, HHb, and tHb at superficial and deep layers were monitored for 5 minutes using a 2-channel near-infrared spectroscopy. Results Thirty seconds after CS application, we observed a decrease from baseline in O2Hb and tHb only in the superficial layer that was maintained for 3 minutes. Conclusions Application of CS induced a transient change in blood flow and oxygenation of the superficial tissues with no change in deeper tissues over the healthy vastus medialis muscle. The limited physiologic effect of CS on the superficial hemodynamics and oxygenation of limb muscles may limit the therapeutic benefit of this cryotherapy modality to a temporary analgesic effect, a hypothesis that warrants a clinical trial on traumatized muscles. PMID:26098273

TUNABLE MAGNETIC AND ELECTRICAL PROPERTIES OF Co-DOPED ZnO FILMS BY VARYING OXYGEN PARTIAL PRESSURE

OpenAIRE

L. G. WANG; H. W. ZHANG; X. L. TANG; Y. X. LI; Z. Y. ZHONG

2011-01-01

High quality Co-doped ZnO films with good reproducibility have been prepared under different oxygen partial pressure by radio-frequency magnetron sputtering. These films were characterized using numerous characterization techniques including X-ray diffraction, electrical transport, and magnetization measurements. The effect of oxygen partial pressure on the structural, magnetic, and electrical properties of Co-doped ZnO films has been systematically studied. It was found that the structural, ...

Neuroprotection of hyperbaric oxygen therapy in sub-acute traumatic brain injury: not by immediately improving cerebral oxygen saturation and oxygen partial pressure.

Science.gov (United States)

Zhou, Bao-Chun; Liu, Li-Jun; Liu, Bing

2016-09-01

Although hyperbaric oxygen (HBO) therapy can promote the recovery of neural function in patients who have suffered traumatic brain injury (TBI), the underlying mechanism is unclear. We hypothesized that hyperbaric oxygen treatment plays a neuroprotective role in TBI by increasing regional transcranial oxygen saturation (rSO 2 ) and oxygen partial pressure (PaO 2 ). To test this idea, we compared two groups: a control group with 20 healthy people and a treatment group with 40 TBI patients. The 40 patients were given 100% oxygen of HBO for 90 minutes. Changes in rSO 2 were measured. The controls were also examined for rSO 2 and PaO 2 , but received no treatment. rSO 2 levels in the patients did not differ significantly after treatment, but levels before and after treatment were significantly lower than those in the control group. PaO 2 levels were significantly decreased after the 30-minute HBO treatment. Our findings suggest that there is a disorder of oxygen metabolism in patients with sub-acute TBI. HBO does not immediately affect cerebral oxygen metabolism, and the underlying mechanism still needs to be studied in depth.

Plateau Waves of Intracranial Pressure and Partial Pressure of Cerebral Oxygen.

Science.gov (United States)

Lang, Erhard W; Kasprowicz, Magdalena; Smielewski, Peter; Pickard, John; Czosnyka, Marek

2016-01-01

This study investigates 55 intracranial pressure (ICP) plateau waves recorded in 20 patients after severe traumatic brain injury (TBI) with a focus on a moving correlation coefficient between mean arterial pressure (ABP) and ICP, called PRx, which serves as a marker of cerebrovascular reactivity, and a moving correlation coefficient between ABP and cerebral partial pressure of oxygen (pbtO2), called ORx, which serves as a marker for cerebral oxygen reactivity. ICP and ICPamplitude increased significantly during the plateau waves, whereas CPP and pbtO2 decreased significantly. ABP, ABP amplitude, and heart rate remained unchanged. In 73 % of plateau waves PRx increased during the wave. ORx showed an increase during and a decrease after the plateau waves, which was not statistically significant. Our data show profound cerebral vasoparalysis on top of the wave and, to a lesser extent, impairment of cerebral oxygen reactivity. The different behavior of the indices may be due to the different latencies of the cerebral blood flow and oxygen level control mechanisms. While cerebrovascular reactivity is a rapidly reacting mechanism, cerebral oxygen reactivity is slower.

Modelling the Molecular Transportation of Subcutaneously Injected Salubrinal

Directory of Open Access Journals (Sweden)

Andy Chen

2011-01-01

Full Text Available For the subcutaneous administration of a chemical agent (salubrinal, we constructed a mathematical model of molecule transportation and subsequently evaluated the kinetics of diffusion, convection, and molecular turnover. Salubrinal is a potential therapeutic agent that can reduce cellular damage and death. The understanding of its temporal profiles in local tissue as well as in a whole body is important to develop a proper strategy for its administration. Here, the diffusion and convection kinetics was formulated using partial and ordinary differential equations in one- and three-dimensional (semi-spherical coordinates. Several key parameters including an injection velocity, a diffusion coefficient, thickness of subcutaneous tissue, and a permeability factor at the tissue-blood boundary were estimated from experimental data in rats. With reference to analytical solutions in a simplified model without convection, numerical solutions revealed that the diffusion coefficient and thickness of subcutaneous tissue determined the timing of the peak concentration in the plasma, and its magnitude was dictated by the permeability factor. Furthermore, the initial velocity, induced by needle injection, elevated an immediate transport of salubrinal at t < 1h. The described analysis with a combination of partial and ordinary differential equations contributes to the prediction of local and systemic effects and the understanding of the transportation mechanism of salubrinal and other agents.

Effect of Oxygen Partial Pressure on the Electrical and Optical Properties of DC Magnetron Sputtered Amorphous TiO2 Films

OpenAIRE

Chandra Sekhar, M.; Kondaiah, P.; Radha Krishna, B.; Uthanna, S.

2013-01-01

Titanium dioxide (TiO2) thin films were deposited on p-Si (100) and Corning glass substrates held at room temperature by DC magnetron sputtering at different oxygen partial pressures in the range 9 × 10−3–9 × 10−2 Pa. The influence of oxygen partial pressure on the structural, electrical, and optical properties of the deposited films was systematically studied. XPS studies confirmed that the film formed at an oxygen partial pressure of 6×10−2 Pa was nearly stoichiometric. TiO2 films formed at...

Growth of the microalgae Neochloris oleoabundans at high partial oxygen pressures and sub-saturating light intensity.

Science.gov (United States)

Sousa, Cláudia; de Winter, Lenneke; Janssen, Marcel; Vermuë, Marian H; Wijffels, René H

2012-01-01

The effect of partial oxygen pressure on growth of Neochloris oleoabundans was studied at sub-saturating light intensity in a fully-controlled stirred tank photobioreactor. At the three partial oxygen pressures tested (P(O)₂= 0.24; 0.63; 0.84 bar), the specific growth rate was 1.38; 1.36 and 1.06 day(-1), respectively. An increase of the P(CO)₂from 0.007 to 0.02 bar at P(O₂) of 0.84 bar resulted in an increase in the growth rate from 1.06 to 1.36 day(-1). These results confirm that the reduction of algal growth at high oxygen concentrations at sub-saturating light conditions is mainly caused by competitive inhibition of Rubisco. This negative effect on growth can be overcome by restoring the O(2)/CO(2) ratio by an increase in the partial carbon dioxide pressure. In comparison to general practice (P(O(2)) = 0.42 bar), working at partial O(2) pressure of 0.84 bar could reduce the energy requirement for degassing by a factor of 3-4. Copyright © 2011 Elsevier Ltd. All rights reserved.

Oxygen Partial Pressure Is a Rate-Limiting Parameter for Cell Proliferation in 3D Spheroids Grown in Physioxic Culture Condition.

Science.gov (United States)

Gomes, Aurélie; Guillaume, Ludivine; Grimes, David Robert; Fehrenbach, Jérôme; Lobjois, Valérie; Ducommun, Bernard

2016-01-01

The in situ oxygen partial pressure in normal and tumor tissues is in the range of a few percent. Therefore, when studying cell growth in 3D culture systems, it is essential to consider how the physiological oxygen concentration, rather than the one in the ambient air, influences the proliferation parameters. Here, we investigated the effect of reducing oxygen partial pressure from 21% to 5% on cell proliferation rate and regionalization in a 3D tumor spheroid model. We found that 5% oxygen concentration strongly inhibited spheroid growth, changed the proliferation gradient and reduced the 50% In Depth Proliferation index (IDP50), compared with culture at 21% oxygen. We then modeled the oxygen partial pressure profiles using the experimental data generated by culturing spheroids in physioxic and normoxic conditions. Although hypoxia occurred at similar depth in spheroids grown in the two conditions, oxygen partial pressure was a major rate-limiting factor with a critical effect on cell proliferation rate and regionalization only in spheroids grown in physioxic condition and not in spheroids grown at atmospheric normoxia. Our findings strengthen the need to consider conducting experiment in physioxic conditions (i.e., tissue normoxia) for proper understanding of cancer cell biology and the evaluation of anticancer drugs in 3D culture systems.

Separating the effects of partial submergence and soil oxygen demand on plant physiology.

Science.gov (United States)

van Bodegom, Peter M; Sorrell, Brian K; Oosthoek, Annelies; Bakker, Chris; Aerts, Rien

2008-01-01

In wetlands, a distinct zonation of plant species composition occurs along moisture gradients, due to differential flooding tolerance of the species involved. However, "flooding" comprises two important, distinct stressors (soil oxygen demand [SOD] and partial submergence) that affect plant survival and growth. To investigate how these two flooding stressors affect plant performance, we executed a factorial experiment (water depth x SOD) for six plant species of nutrient-rich and nutrient-poor conditions, occurring along a moisture gradient in Dutch dune slacks. Physiological, growth, and biomass responses to changed oxygen availability were quantified for all species. The responses were consistent with field zonation, but the two stressors affected species differently. Increased SOD increased root oxygen deprivation, as indicated by either raised porosity or increased alcohol dehydrogenase (ADH) activity in roots of flood-intolerant species (Calamagrostis epigejos and Carex arenaria). While SOD affected root functioning, partial submergence tended more to reduce photosynthesis (as shown both by gas exchange and 13C assimilation), leaf dark respiration, 13C partitioning from shoots to roots, and growth of these species. These processes were especially affected if the root oxygen supply was depleted by a combination of flooding and increased SOD. In contrast, the most flood-tolerant species (Juncus subnodulosus and Typha latifolia) were unaffected by any treatment and maintained high internal oxygen concentrations at the shoot : root junction and low root ADH activity in all treatments. For these species, the internal oxygen transport capacity was well in excess of what was needed to maintain aerobic metabolism across all treatments, although there was some evidence for effects of SOD on their nitrogen partitioning (as indicated by 865N values) and photosynthesis. Two species intermediate in flooding tolerance (Carex nigra and Schoenus nigricans) responded more

Quantitative and qualitative differences in subcutaneous adipose tissue stores across lipodystrophy types shown by magnetic resonance imaging

International Nuclear Information System (INIS)

Al-Attar, Salam A; Pollex, Rebecca L; Robinson, John F; Miskie, Brooke A; Walcarius, Rhonda; Little, Cynthia Harper; Rutt, Brian K; Hegele, Robert A

2007-01-01

Lipodystrophies are characterized by redistributed subcutaneous fat stores. We previously quantified subcutaneous fat by magnetic resonance imaging (MRI) in the legs of two patients with familial partial lipodystrophy subtypes 2 and 3 (FPLD2 and FPLD3, respectively). We now extend the MRI analysis across the whole body of patients with different forms of lipodystrophy. We studied five subcutaneous fat stores (supraclavicular, abdominal, gluteal, thigh and calf) and the abdominal visceral fat stores in 10, 2, 1, 1 and 2 female subjects with, respectively, FPLD2, FPLD3, HIV-related partial lipodystrophy (HIVPL), acquired partial lipodystrophy (APL), congenital generalized lipodystrophy (CGL) and in six normal control subjects. Compared with normal controls, FPLD2 subjects had significantly increased supraclavicular fat, with decreased abdominal, gluteal, thigh and calf subcutaneous fat. FPLD3 subjects had increased supraclavicular and abdominal subcutaneous fat, with less severe reductions in gluteal, thigh and calf fat compared to FPLD2 subjects. The repartitioning of fat in the HIVPL subject closely resembled that of FPLD3 subjects. APL and CGL subjects had reduced upper body, gluteal and thigh subcutaneous fat; the APL subject had increased, while CGL subjects had decreased subcutaneous calf fat. Visceral fat was markedly increased in FPLD2 and APL subjects. Semi-automated MRI-based adipose tissue quantification indicates differences between various lipodystrophy types in these studied clinical cases and is a potentially useful tool for extended quantitative phenomic analysis of genetic metabolic disorders. Further studies with a larger sample size are essential for confirming these preliminary findings

Four-Hour Dives with Exercise While Breathing Oxygen Partial Pressure of 1.3 ATM

National Research Council Canada - National Science Library

Shykoff, B

2006-01-01

...) or less but does not address the possible accumulation of effects over multiple days. We have conducted experimental four-hour dives with oxygen partial pressure (Po2) of approximately 1.4 atmospheres (atm...

Three-Hour Dives with Exercise While Breathing Oxygen Partial Pressure of 1.3 ATM

National Research Council Canada - National Science Library

Shykoff, B

2007-01-01

...) or less but does not address the possible accumulation of effects over multiple days. When we conducted experimental four-hour dives with oxygen partial pressure (Po2) of approximately 1.4 atmospheres (atm...

The change of steel surface chemistry regarding oxygen partial pressure and dew point

Science.gov (United States)

Norden, Martin; Blumenau, Marc; Wuttke, Thiemo; Peters, Klaus-Josef

2013-04-01

By investigating the surface state of a Ti-IF, TiNb-IF and a MnCr-DP after several series of intercritical annealing, the impact of the annealing gas composition on the selective oxidation process is discussed. On behalf of the presented results, it can be concluded that not the general oxygen partial pressure in the annealing furnace, which is a result of the equilibrium reaction of water and hydrogen, is the main driving force for the selective oxidation process. It is shown that the amounts of adsorbed gases at the strip surface and the effective oxygen partial pressure resulting from the adsorbed gases, which is mainly dependent on the water content of the annealing furnace, is driving the selective oxidation processes occurring during intercritical annealing. Thus it is concluded, that for industrial applications the dew point must be the key parameter value for process control.

Residual oxygen time model for oxygen partial pressure near 130 kPa (1.3 atm).

Science.gov (United States)

Shykoff, Barbara E

2015-01-01

A two-part residual oxygen time model predicts the probability of detectible pulmonary oxygen toxicity P(P[O2tox]) after dives with oxygen partial pressure (PO2) approximately 130 kPa, and provides a tool to plan dive series with selected risk of P[O2tox]. Data suggest that pulmonary oxygen injury at this PO2 is additive between dives. Recovery begins after a delay and continues during any following dive. A logistic relation expresses P(P[O2tox]) as a function of dive duration (T(dur)) [hours]: P(P[O2tox]) = 100/[1+exp (3.586-0.49 x T(dur))] This expression maps T(dur) to P(P[O2tox]) or, in the linear mid-portion of the curve, P(P[O2tox]) usefully to T(dur). For multiple dives or during recovery, it maps to an equivalent dive duration, T(eq). T(eq) was found after second dives of duration T(dur 2). Residual time from the first dive t(r) = T(eq) - T(dur2). With known t(r), t and T(dur) a recovery model was fitted. t(r) = T(dur) x exp [-k x((t-5)/T(dur)2], where t = t - 5 hours, k = 0.149 for resting, and 0.047 for exercising divers, and t represents time after surfacing. The fits were assessed for 1,352 man-dives. Standard deviations of the residuals were 8.5% and 18.3% probability for resting or exercise dives, respectively.

Reversible effects of oxygen partial pressure on genes associated with placental angiogenesis and differentiation in primary-term cytotrophoblast cell culture.

Science.gov (United States)

Debiève, F; Depoix, C; Gruson, D; Hubinont, C

2013-09-01

Timely regulated changes in oxygen partial pressure are important for placental formation. Disturbances could be responsible for pregnancy-related diseases like preeclampsia and intrauterine growth restriction. We aimed to (i) determine the effect of oxygen partial pressure on cytotrophoblast differentiation; (ii) measure mRNA expression and protein secretion from genes associated with placental angiogenesis; and (iii) determine the reversibility of these effects at different oxygen partial pressures. Term cytotrophoblasts were incubated at 21% and 2.5% O2 for 96 hr, or were switched between the two oxygen concentrations after 48 hr. Real-time PCR and enzyme-linked immunosorbent assays (ELISAs) were used to evaluate cell fusion and differentiation, measuring transcript levels for those genes involved in cell fusion and placental angiogenesis, including VEGF, PlGF, VEGFR1, sVEGFR1, sENG, INHA, and GCM1. Cytotrophoblasts underwent fusion and differentiation in 2.5% O2 . PlGF expression was inhibited while sVEGFR1 expression increased. VEGF and sENG mRNA expressions increased in 2.5% compared to 21% O2 , but no protein was detected in the cell supernatants. Finally, GCM1 mRNA expression increased during trophoblast differentiation at 21% O2 , but was inhibited at 2.5% O2 . These mRNA expression effects were reversed by returning the cells to 21% O2 . Thus, low-oxygen partial pressure does not inhibit term-cytotrophoblast cell fusion and differentiation in vitro. Lowering the oxygen partial pressure from 21% to 2.5% caused normal-term trophoblasts to reversibly modify their expression of genes associated with placental angiogenesis. This suggests that modifications observed in pregnancy diseases such as preeclampsia or growth retardation are probably due to an extrinsic effect on trophoblasts. Copyright © 2013 Wiley Periodicals, Inc.

Influence of Oxygen Partial Pressure during Processing on the Thermoelectric Properties of Aerosol-Deposited CuFeO₂.

Science.gov (United States)

Stöcker, Thomas; Exner, Jörg; Schubert, Michael; Streibl, Maximilian; Moos, Ralf

2016-03-24

In the field of thermoelectric energy conversion, oxide materials show promising potential due to their good stability in oxidizing environments. Hence, the influence of oxygen partial pressure during synthesis on the thermoelectric properties of Cu-Delafossites at high temperatures was investigated in this study. For these purposes, CuFeO₂ powders were synthetized using a conventional mixed-oxide technique. X-ray diffraction (XRD) studies were conducted to determine the crystal structures of the delafossites associated with the oxygen content during the synthesis. Out of these powders, films with a thickness of about 25 µm were prepared by the relatively new aerosol-deposition (AD) coating technique. It is based on a room temperature impact consolidation process (RTIC) to deposit dense solid films of ceramic materials on various substrates without using a high-temperature step during the coating process. On these dense CuFeO₂ films deposited on alumina substrates with electrode structures, the Seebeck coefficient and the electrical conductivity were measured as a function of temperature and oxygen partial pressure. We compared the thermoelectric properties of both standard processed and aerosol deposited CuFeO₂ up to 900 °C and investigated the influence of oxygen partial pressure on the electrical conductivity, on the Seebeck coefficient and on the high temperature stability of CuFeO₂. These studies may not only help to improve the thermoelectric material in the high-temperature case, but may also serve as an initial basis to establish a defect chemical model.

A flowing liquid test system for assessing the linearity and time-response of rapid fibre optic oxygen partial pressure sensors.

Science.gov (United States)

Chen, R; Hahn, C E W; Farmery, A D

2012-08-15

The development of a methodology for testing the time response, linearity and performance characteristics of ultra fast fibre optic oxygen sensors in the liquid phase is presented. Two standard medical paediatric oxygenators are arranged to provide two independent extracorporeal circuits. Flow from either circuit can be diverted over the sensor under test by means of a system of rapid cross-over solenoid valves exposing the sensor to an abrupt change in oxygen partial pressure, P O2. The system is also capable of testing the oxygen sensor responses to changes in temperature, carbon dioxide partial pressure P CO2 and pH in situ. Results are presented for a miniature fibre optic oxygen sensor constructed in-house with a response time ≈ 50 ms and a commercial fibre optic sensor (Ocean Optics Foxy), when tested in flowing saline and stored blood. Copyright © 2012 Elsevier B.V. All rights reserved.

Oxidation of SiC/BN/SiC Composites in Reduced Oxygen Partial Pressures

Science.gov (United States)

Opila, Elizabeth J.; Boyd, Meredith

2010-01-01

SiC fiber-reinforced SiC composites with a BN interphase are proposed for use as leading edge structures of hypersonic vehicles. The durability of these materials under hypersonic flight conditions is therefore of interest. Thermogravimetric analysis was used to characterize the oxidation kinetics of both the constituent fibers and composite coupons at four temperatures: 816, 1149, 1343, and 1538 C (1500, 2100, 2450, and 2800 F) and in oxygen partial pressures between 5% and 0.1% (balance argon) at 1 atm total pressure. One edge of the coupons was ground off so the effects of oxygen ingress into the composite could be monitored by post-test SEM and EDS. Additional characterization of the oxidation products was conducted by XPS and TOF-SIMS. Under most conditions, the BN oxidized rapidly, leading to the formation of borosilicate glass. Rapid initial oxidation followed by volatilization of boria lead to protective oxide formation and further oxidation was slow. At 1538C in 5% oxygen, both the fibers and coupons exhibited borosilicate glass formation and bubbling. At 1538C in 0.1% oxygen, active oxidation of both the fibers and the composites was observed leading to rapid SiC degradation. BN oxidation at 1538C in 0.1% oxygen was not significant.

[Generation of Superoxide Radicals by Complex III in Heart Mitochondria and Antioxidant Effect of Dinitrosyl Iron Complexes at Different Partial Pressure of Oxygen].

Science.gov (United States)

Dudylina, A L; Ivanova, M V; Shumaev, K B; Ruuge, E K

2016-01-01

The EPR spin-trapping technique and EPR-oximetry were used to study generation of superoxide radicals in heart mitochondria isolated from Wistar rats under conditions of variable oxygen concentration. Lithium phthalocyanine and TEMPONE-15N-D16 were chosen to determine oxygen content in a gas-permeable capillary tube containing mitochondria. TIRON was used as a spin trap. We investigated the influence of different oxygen concentrations in incubation mixture and demonstrated that heart mitochondria can generate superoxide in complex III at different partial pressure of oxygen as well as under the conditions of deep hypoxia (partial pressure of oxygen, but the magnitude and kinetic characteristics of the effect depended on the concentration of the drug.

Intraoperative transfusion threshold and tissue oxygenation

DEFF Research Database (Denmark)

Nielsen, K; Dahl, B; Johansson, P I

2012-01-01

Transfusion with allogeneic red blood cells (RBCs) may be needed to maintain oxygen delivery during major surgery, but the appropriate haemoglobin (Hb) concentration threshold has not been well established. We hypothesised that a higher level of Hb would be associated with improved subcutaneous...... oxygen tension during major spinal surgery....

Subcutaneous Injections

DEFF Research Database (Denmark)

Thomsen, Maria

This thesis is about visualization and characterization of the tissue-device interaction during subcutaneous injection. The tissue pressure build-up during subcutaneous injections was measured in humans. The insulin pen FlexTouchr (Novo Nordisk A/S) was used for the measurements and the pressure ...

Subcutaneous emphysema as a complication of tooth extraction

Directory of Open Access Journals (Sweden)

Vacić Aca

2004-01-01

Full Text Available Subcutaneous emphysema is a rare complication in dentistry, which may lead to diagnostic errors and inadequate therapy. A 17 years old female patient, in whom the separation of tooth roots was performed by the use of air-powered drill during the extraction of the first right lower molar, is presented in this paper. During the intervention, swelling of the right half of the face and the lower eyelid suddenly occurred, accompanied with simultaneous feeling of choking, and pressure in the neck and chest. Because of the suspicion of the allergic reaction, the patient was administered antihistaminic agent, together with parenteral corticosteroid, and was sent to an institution where she was treated as an in-patient. During hospitalization, subcutaneous emphysema of the face and neck was diagnosed by physical and x-ray examination. The emphysema completely disappeared after the use of oxygen and antibiotics.

Effects of varying oxygen partial pressure on molten silicon-ceramic substrate interactions

Science.gov (United States)

Ownby, D. P.; Barsoum, M. W.

1980-01-01

The silicon sessile drop contact angle was measured on hot pressed silicon nitride, silicon nitride coated on hot pressed silicon nitride, silicon carbon coated on graphite, and on Sialon to determine the degree to which silicon wets these substances. The post-sessile drop experiment samples were sectioned and photomicrographs were taken of the silicon-substrate interface to observe the degree of surface dissolution and degradation. Of these materials, silicon did not form a true sessile drop on the SiC on graphite due to infiltration of the silicon through the SiC coating, nor on the Sialon due to the formation of a more-or-less rigid coating on the liquid silicon. The most wetting was obtained on the coated Si3N4 with a value of 42 deg. The oxygen concentrations in a silicon ribbon furnace and in a sessile drop furnace were measured using the protable thoria-yttria solid solution electrolyte oxygen sensor. Oxygen partial pressures of 10 to the minus 7 power atm and 10 to the minus 8 power atm were obtained at the two facilities. These measurements are believed to represent nonequilibrium conditions.

Intracrystalline fractionation of oxygen isotopes between hydroxyl and non-hydroxyl sites in kaolinite measured by thermal dehydroxylation and partial fluorination

Science.gov (United States)

Girard, Jean-Pierre; Savin, Samuel M.

1996-02-01

Thermal dehydroxylation and partial fluorination techniques were used to measure intracrystalline fractionation of oxygen isotopes between hydroxyl and non-hydroxyl sites in kaolinite. Several aliquots of a well characterized, fine-grained (rates, and target temperatures. Measured δ18O values of both the liberated water and the dehydroxylated residue are consistent over a wide range of temperatures (550 850°C) when dehydroxylation is performed in a single-step fashion at a rapid heating rate (>50°C/min.). Similar dehydroxylation experiments indicate that brucite dehydroxylation occurs without any significant isotopic fractionation of the oxygen isotopes. By extrapolation we postulate that no significant fractionation occurs during single-step thermal dehydroxylation of fine-grained kaolinite, provided that dehydroxylation is performed under well controlled conditions. In contrast, gibbsite dehydroxylation is accompanied by substantial isotopic fractionation. This is probably the result of the complex, multi-pathway dehydroxylation reaction of this mineral. Similarly, thermal dehydroxylation of coarsegrained (>1 μm) kaolinites and dickites of weathering and hydrothermal origin yield results that are dependent on the temperature of dehydroxylation. We suggest that this effect may be caused by isotopic exchange during diffusion of water molecules through coarse particles. Partial fluorination of fine-grained kaolinite in the presence of excess F2 at low temperatures (rate of reaction of hydroxyl oxygen than of non-hydroxyl oxygen, but examination of the isotopic data as well as XRD and IR analyses of the residues after partial fluorination indicates that the separation between the two types of oxygen is not complete. The results, therefore, do not yield a reliable δ18O value of the hydroxyl oxygen. The results of this study suggest that the thermal dehydroxylation technique may be appropriate for analysis of OH groups in fine-grained kaolinite. The partial

Comparing CT perfusion with oxygen partial pressure in a rabbit VX2 soft-tissue tumor model

International Nuclear Information System (INIS)

Sun Changjin; Li Chao; Lv Haibo

2014-01-01

The aim of this study was to evaluate the oxygen partial pressure of the rabbit model of the VX2 tumor using a 64-slice perfusion CT and to compare the results with that obtained using the oxygen microelectrode method. Perfusion CT was performed for 45 successfully constructed rabbit models of a VX2 brain tumor. The perfusion values of the brain tumor region of interest, the blood volume (BV), the time to peak (TTP) and the peak enhancement intensity (PEI) were measured. The results were compared with the partial pressure of oxygen (PO2) of that region of interest obtained using the oxygen microelectrode method. The perfusion values of the brain tumor region of interest in 45 successfully constructed rabbit models of a VX2 brain tumor ranged from 1.3–127.0 (average, 21.1 ± 26.7 ml/min/ml); BV ranged from 1.2–53.5 ml/100g (average, 22.2 ± 13.7 ml/100g); PEI ranged from 8.7–124.6 HU (average, 43.5 ± 28.7 HU); and TTP ranged from 8.2–62.3 s (average, 38.8 ± 14.8 s). The PO2 in the corresponding region ranged from 0.14–47 mmHg (average, 16 ± 14.8 mmHg). The perfusion CT positively correlated with the tumor PO2, which can be used for evaluating the tumor hypoxia in clinical practice. (author)

Comparing CT perfusion with oxygen partial pressure in a rabbit VX2 soft-tissue tumor model.

Science.gov (United States)

Sun, Chang-Jin; Li, Chao; Lv, Hai-Bo; Zhao, Cong; Yu, Jin-Ming; Wang, Guang-Hui; Luo, Yun-Xiu; Li, Yan; Xiao, Mingyong; Yin, Jun; Lang, Jin-Yi

2014-01-01

The aim of this study was to evaluate the oxygen partial pressure of the rabbit model of the VX2 tumor using a 64-slice perfusion CT and to compare the results with that obtained using the oxygen microelectrode method. Perfusion CT was performed for 45 successfully constructed rabbit models of a VX2 brain tumor. The perfusion values of the brain tumor region of interest, the blood volume (BV), the time to peak (TTP) and the peak enhancement intensity (PEI) were measured. The results were compared with the partial pressure of oxygen (PO2) of that region of interest obtained using the oxygen microelectrode method. The perfusion values of the brain tumor region of interest in 45 successfully constructed rabbit models of a VX2 brain tumor ranged from 1.3-127.0 (average, 21.1 ± 26.7 ml/min/ml); BV ranged from 1.2-53.5 ml/100g (average, 22.2 ± 13.7 ml/100g); PEI ranged from 8.7-124.6 HU (average, 43.5 ± 28.7 HU); and TTP ranged from 8.2-62.3 s (average, 38.8 ± 14.8 s). The PO2 in the corresponding region ranged from 0.14-47 mmHg (average, 16 ± 14.8 mmHg). The perfusion CT positively correlated with the tumor PO2, which can be used for evaluating the tumor hypoxia in clinical practice.

Hypothesis: the regulation of the partial pressure of oxygen by the serotonergic nervous system in hypoxia.

Science.gov (United States)

Devereux, Diana; Ikomi-Kumm, Julie

2013-03-01

The regulation of the partial pressure of oxygen by the serotonergic nervous system in hypoxia is a hypothesis, which proposes an inherent operative system in homo sapiens that allows central nervous system and endocrine-mediated vascular system adaption to variables in partial pressure of oxygen, pH and body composition, while maintaining sufficient oxygen saturation for the immune system and ensuring protection of major organs in hypoxic and suboptimal conditions. While acknowledging the importance of the Henderson-Hasselbalch equation in the regulation of acid base balance, the hypothesis seeks to define the specific neuroendocrine/vascular mechanisms at work in regulating acid base balance in hypoxia and infection. The SIA (serotonin-immune-adrenergic) system is proposed as a working model, which allows central nervous system and endocrine-mediated macro- and micro vascular 'fine tuning'. The neurotransmitter serotonin serves as a 'hypoxic sensor' in concert with other operators to orchestrate homeostatic balance in normal and pathological states. The SIA system finely regulates oxygen, fuel and metabolic buffering systems at local sites to ensure optimum conditions for the immune response. The SIA system is fragile and its operation may be affected by infection, stress, diet, environmental toxins and lack of exercise. The hypothesis provides new insight in the area of neuro-gastroenterology, and emphasizes the importance of diet and nutrition as a complement in the treatment of infection, as well as the normalization of intestinal flora following antibiotic therapy. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Effect of Humidity and Oxygen Partial Pressure on LSM–YSZ Cathode

DEFF Research Database (Denmark)

Knöfel, Christina; Chen, Ming; Mogensen, Mogens Bjerg

2011-01-01

Two series of anode supported solid oxide fuel cells (SOFC) were prepared, one with a composite cathode layer of lanthanum strontium manganite (LSM) and yttria stabilized zirconia (YSZ) on top and the other further has a LSM current collector layer on top. The fuel cells were heat treated at 1...... of manganese concentration and strontium enrichment on the surface of the materials. Formation of monoclinic zirconia and zirconate phases was also observed. These results give a closer insight into possible degradation mechanisms of SOFC composite cathode materials in dependence of humidity and oxygen partial...

Alteration of striatal dopamine levels under various partial pressure of oxygen in pre-convulsive and convulsive phases in freely-moving rats.

Science.gov (United States)

Lavoute, Cécile; Weiss, Michel; Risso, Jean-Jacques; Rostain, Jean-Claude

2014-02-01

The purpose of this study was to investigate the change in the striatal dopamine (DA) level in freely-moving rat exposed to different partial pressure of oxygen (from 1 to 5 ATA). Some works have suggested that DA release by the substantia nigra pars compacta (SNc) neurons in the striatum could be disturbed by hyperbaric oxygen (HBO) exposure, altering therefore the basal ganglia activity. Such changes could result in a change in glutamatergic and GABAergic control of the dopaminergic neurons into the SNc. Such alterations could provide more information about the oxygen-induced seizures observed at 5 ATA in rat. DA-sensitive electrodes were implanted into the striatum under general anesthesia. After 1 week rest, awaked rats were exposed to oxygen-nitrogen mixture at a partial pressure of oxygen of 1, 2, 3, 4 and 5 ATA. DA level was monitored continuously (every 3 min) by in vivo voltammetry before and during HBO exposure. HBO induced a decrease in DA level in relationship to the increase in partial pressure of oxygen from 1 ATA to 4 ATA (-15 % at 1 ATA, -30 % at 2 ATA, -40 % at 3 ATA, -45 % at 4 ATA), without signs of oxygen toxicity. At 5 ATA, DA level strongly decreases (-75 %) before seizure which occurred after 27 min ± 7 HBO exposure. After the epileptic seizure the decrease in DA level disappeared. These changes and the biphasic effect of HBO were discussed in function of HBO action on neurochemical regulations of the nigro striatal pathway.

Changes in oxygen partial pressure of brain tissue in an animal model of obstructive apnea

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Torres Marta

2010-01-01

Full Text Available Abstract Background Cognitive impairment is one of the main consequences of obstructive sleep apnea (OSA and is usually attributed in part to the oxidative stress caused by intermittent hypoxia in cerebral tissues. The presence of oxygen-reactive species in the brain tissue should be produced by the deoxygenation-reoxygenation cycles which occur at tissue level during recurrent apneic events. However, how changes in arterial blood oxygen saturation (SpO2 during repetitive apneas translate into oxygen partial pressure (PtO2 in brain tissue has not been studied. The objective of this study was to assess whether brain tissue is partially protected from intermittently occurring interruption of O2 supply during recurrent swings in arterial SpO2 in an animal model of OSA. Methods Twenty-four male Sprague-Dawley rats (300-350 g were used. Sixteen rats were anesthetized and non-invasively subjected to recurrent obstructive apneas: 60 apneas/h, 15 s each, for 1 h. A control group of 8 rats was instrumented but not subjected to obstructive apneas. PtO2 in the cerebral cortex was measured using a fast-response oxygen microelectrode. SpO2 was measured by pulse oximetry. The time dependence of arterial SpO2 and brain tissue PtO2 was carried out by Friedman repeated measures ANOVA. Results Arterial SpO2 showed a stable periodic pattern (no significant changes in maximum [95.5 ± 0.5%; m ± SE] and minimum values [83.9 ± 1.3%]. By contrast, brain tissue PtO2 exhibited a different pattern from that of arterial SpO2. The minimum cerebral cortex PtO2 computed during the first apnea (29.6 ± 2.4 mmHg was significantly lower than baseline PtO2 (39.7 ± 2.9 mmHg; p = 0.011. In contrast to SpO2, the minimum and maximum values of PtO2 gradually increased (p 2 were significantly greater relative to baseline and the first apnea dip, respectively. Conclusions These data suggest that the cerebral cortex is partially protected from intermittently occurring interruption of

Critical hematocrit and oxygen partial pressure in the beating heart of pigs.

Science.gov (United States)

Hiebl, B; Mrowietz, C; Ploetze, K; Matschke, K; Jung, F

2010-12-01

In cardiac surgery the substitution of lost blood volume by plasma substitutes is a common therapeutical approach. None of the currently available blood substitutes has a sufficient oxygen transport capacity. This can limit the functional integrity of the myocardium known as highly oxygen consumptive. The study was aimed to get information about the minimal hematocrit, also known as critical hematocrit (cHct), which guarantees a stable and adequate oxygen partial pressure in the myocardium (pO2). In adult female pigs (n=7) the hematocrit was reduced by isovolemic blood dilution with an intravenous infusion of isotonic 4% gelatine polysuccinate solution, The substituted blood volume ranged between 3000ml and 7780ml (mean: 5254±1672ml). In all animals the pO2 of the myocardium of the beating heart and of the resting skeletal muscle increased until blood dilution resulted in a Hct decrease down to 15%. Further blood dilution resulted in a decrease of the pO2. Only after the Hct was <10% the pO2 was lower than before blood dilution and accompanied by a lethal ischemia of the myocardium. These data indicate a cHct of about 10% in the pig animal model. Copyright © 2010 Elsevier Inc. All rights reserved.

Ce-Fe-O mixed oxide as oxygen carrier for the direct partial oxidation of methane to syngas

Institute of Scientific and Technical Information of China (English)

魏永刚; 王华; 李孔斋

2010-01-01

The Ce-Fe-O mixed oxide with a ratio of Ce/Fe=7:3, which was prepared by coprecipitation method and employed as oxygen carrier, for direct partial oxidation of methane to syngas in the absence of gaseous oxygen was explored. The mixed oxide was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), and the catalytic performances were studied in a fixed-bed quartz reactor and a thermogravimetric reactor, respectively. Approximately 99.4% H2 se...

Measurement of Local Partial Pressure of Oxygen in the Brain Tissue under Normoxia and Epilepsy with Phosphorescence Lifetime Microscopy

Science.gov (United States)

Zhang, Cong; Bélanger, Samuel; Pouliot, Philippe; Lesage, Frédéric

2015-01-01

In this work a method for measuring brain oxygen partial pressure with confocal phosphorescence lifetime microscopy system is reported. When used in conjunction with a dendritic phosphorescent probe, Oxyphor G4, this system enabled minimally invasive measurements of oxygen partial pressure (pO2) in cerebral tissue with high spatial and temporal resolution during 4-AP induced epileptic seizures. Investigating epileptic events, we characterized the spatio-temporal distribution of the "initial dip" in pO2 near the probe injection site and along nearby arterioles. Our results reveal a correlation between the percent change in the pO2 signal during the "initial dip" and the duration of seizure-like activity, which can help localize the epileptic focus and predict the length of seizure. PMID:26305777

Measurement of Local Partial Pressure of Oxygen in the Brain Tissue under Normoxia and Epilepsy with Phosphorescence Lifetime Microscopy.

Science.gov (United States)

Zhang, Cong; Bélanger, Samuel; Pouliot, Philippe; Lesage, Frédéric

2015-01-01

In this work a method for measuring brain oxygen partial pressure with confocal phosphorescence lifetime microscopy system is reported. When used in conjunction with a dendritic phosphorescent probe, Oxyphor G4, this system enabled minimally invasive measurements of oxygen partial pressure (pO2) in cerebral tissue with high spatial and temporal resolution during 4-AP induced epileptic seizures. Investigating epileptic events, we characterized the spatio-temporal distribution of the "initial dip" in pO2 near the probe injection site and along nearby arterioles. Our results reveal a correlation between the percent change in the pO2 signal during the "initial dip" and the duration of seizure-like activity, which can help localize the epileptic focus and predict the length of seizure.

[Peroxynitrite effect on the haemoglobin oxygen affinity in vitro in presence of different partial pressure of carbon dioxide].

Science.gov (United States)

Stepuro, T L; Zinchuk, V V

2011-08-01

Peroxynitrite (ONOO-) besides its toxic possesses regulatory action that includes the modulation of oxygen binding properties of blood. The aim of this work was to estimate ONOO- effect on the haemoglobin oxygen affinity (HOA) in vitro in presence of different partial pressure of carbon dioxide (CO2). The ONOO- presence in venous blood in conditions of hypercapnia induced oxyhaemoglobin dissociation curve shift leftward while in hypocapnic conditions the result of a different character was obtained. The revealed effect of ONOO- is realized, possibly, through various modifications ofhaemoglobin whose formation is dependent on the CO2 pressure. The ONOO- influences the HOA in different manner that can be important in regulation of blood oxygenation in lungs and maintenance of oxygen consumption in tissues.

[The effects of oxygen partial pressure changes on the osteometric markers of the bone tissue in rats].

Science.gov (United States)

Berezovs'kyĭ, V Ia; Zamors'ka, T M; Ianko, R V

2013-01-01

Our purpose was to investigate the oxygen partial pressure changes on the osteometric and biochemical markers of bone tissue in rats. It was shown that breathing of altered gas mixture did not change the mass, general length, sagittal diameter and density thigh-bones in 12-month Wistar male-rats. The dosed normobaric hypoxia increased the activity of alkaline phosphatase and decreased the activity of tartrate-resistant acid phosphatase. At the same time normobaric hyperoxia with 40 and 90% oxygen conversely decreased the activity of alkaline phosphatase and increased the activity of tartrate-resistant acid phosphatase.

Decline in arterial partial pressure of oxygen after exercise: a surrogate marker of pulmonary vascular obstructive disease in patients with atrial septal defect and severe pulmonary hypertension.

Science.gov (United States)

Laksmivenkateshiah, Srinivas; Singhi, Anil K; Vaidyanathan, Balu; Francis, Edwin; Karimassery, Sundaram R; Kumar, Raman K

2011-06-01

To examine the utility of decline in arterial partial pressure of oxygen after exercise as a marker of pulmonary vascular obstructive disease in patients with atrial septal defect and pulmonary hypertension. Treadmill exercise was performed in 18 patients with atrial septal defect and pulmonary hypertension. Arterial blood gas samples were obtained before and after peak exercise. A decline in the arterial pressure of oxygen of more than 10 millimetres of mercury after exercise was considered significant based on preliminary tests conducted on the controls. Cardiac catheterisation was performed in all patients and haemodynamic data sets were obtained on room air, oxygen, and a mixture of oxygen and nitric oxide (30-40 parts per million). There were 10 patients who had more than a 10 millimetres of mercury drop in arterial partial pressure of oxygen after exercise and who had a basal pulmonary vascular resistance index of more than 7 Wood units per square metre. Out of eight patients who had less than a 10 millimetres of mercury drop in arterial partial pressure of oxygen after exercise, seven had a basal pulmonary vascular resistance index of less than 7 Wood units per square metre, p equals 0.0001. A decline in arterial partial pressure of oxygen of more than 10 millimetres of mercury predicted a basal pulmonary vascular resistance index of more than 7 Wood units per square metre with a specificity of 100% and a sensitivity of 90%. A decline in arterial partial pressure of oxygen following exercise appears to predict a high pulmonary vascular resistance index in patients with atrial septal defect and pulmonary hypertension. This test is a useful non-invasive marker of pulmonary vascular obstructive disease in this subset.

Subcutaneous granuloma annulare

Directory of Open Access Journals (Sweden)

Dhar Sandipan

1993-01-01

Full Text Available Two cases of subcutaneous granuloma annulare are reported. Clinical presentation was in the form of hard subcutaneous nodules, histopathology confirmed the clinical diagnosis. The cases were unique because of onset in adult age, occurrence over unusual sites and absence of classical lesions of granuloma annulare elsewhere.

Structural phase diagram and equilibrium oxygen partial pressure of YBa₂Cu₃O_6+x

DEFF Research Database (Denmark)

Andersen, N.H.; Lebech, B.; Poulsen, H.F.

1990-01-01

of the ordering of oxygen. Oxygen equilibrium partial pressure shows significant variations with temperature and concentration which indicate that x = 0.15 and x = 0.92 are minimum and maximum oxygen concentrations. Measurements of oxygen in-diffusion flow show relaxation type behaviour: View the MathML source......An experimental technique by which in-situ gas volumetric measurements are carried out on a neutron powder diffractometer, is presented and used for simultaneous studies of oxygen equilibrium partial pressure and the structural phase diagram of YBa2Cu3O6 + x. Experimental data was collected under...... near equilibrium conditions at 350 points in (x,T)-space with 0.15 gas law in connection with iodiometric titration and structural analyses. The temperature...

Dependence of mitochondrial and cytosolic adenine nucleotides on oxygen partial pressure in isolated hepatocytes. Application of a new rapid high pressure filtration technique for fractionation.

OpenAIRE

Hummerich, H; de Groot, H; Noll, T; Soboll, S

1988-01-01

By using a new rapid high pressure filtration technique, mitochondrial and cytosolic ATP and ADP contents were determined in isolated hepatocytes at different oxygen partial pressures. At 670 mmHg, subcellular adenine nucleotide contents and ATP/ADP ratios were comparable with values obtained with the digitonin fractionation technique. However at lower oxygen partial pressure ADP appears to be rephosphorylated during digitonin fractionation whereas with high pressure filtration fractionation ...

Mathematical Modelling of Intraretinal Oxygen Partial Pressure

African Journals Online (AJOL)

Erah

The system of non-linear differential equations was solved numerically using Runge-kutta. Nystroms method. ... artery occlusion. Keywords: Mathematical modeling, Intraretinal oxygen pressure, Retinal capillaries, Oxygen ..... Mass transfer,.

Non-site-specific allosteric effect of oxygen on human hemoglobin under high oxygen partial pressure.

Science.gov (United States)

Takayanagi, Masayoshi; Kurisaki, Ikuo; Nagaoka, Masataka

2014-04-08

Protein allostery is essential for vital activities. Allosteric regulation of human hemoglobin (HbA) with two quaternary states T and R has been a paradigm of allosteric structural regulation of proteins. It is widely accepted that oxygen molecules (O2) act as a "site-specific" homotropic effector, or the successive O2 binding to the heme brings about the quaternary regulation. However, here we show that the site-specific allosteric effect is not necessarily only a unique mechanism of O2 allostery. Our simulation results revealed that the solution environment of high O2 partial pressure enhances the quaternary change from T to R without binding to the heme, suggesting an additional "non-site-specific" allosteric effect of O2. The latter effect should play a complementary role in the quaternary change by affecting the intersubunit contacts. This analysis must become a milestone in comprehensive understanding of the allosteric regulation of HbA from the molecular point of view.

Subcutaneous dissociative conscious sedation (sDCS an alternative method for airway regional blocks: a new approach

Directory of Open Access Journals (Sweden)

Javid Mihan J

2011-10-01

Full Text Available Abstract Background Predicted difficult airway is a definite indication for awake intubation and spontaneous ventilation. Airway regional blocks which are commonly used to facilitate awake intubation are sometimes impossible or forbidden. On the other hand deep sedation could be life threatening in the case of compromised airway. The aim of this study is evaluating "Subcutaneous Dissociative Conscious Sedation" (sDCS as an alternative method to airway regional blocks for awake intubation. Methods In this prospective, non-randomized study, 30 patients with predicted difficult airway (laryngeal tumors, who were scheduled for direct laryngoscopic biopsy (DLB, underwent "Subcutaneous Dissociative Conscious Sedation" (sDCS exerted by intravenous fentanyl 3-4ug/kg and subcutaneous ketamine 0.6-0.7 mg/kg. The tongue and pharynx were anesthetized with lidocaine spray (4%. 10 minutes after a subcutaneous injection of ketamine direct laryngoscopy was performed. Extra doses of fentanyl 50-100 ug were administered if the patient wasn't cooperative enough for laryngoscopy. Patients were evaluated for hemodynamic stability (heart rate and blood pressure, oxygen saturation (Spo2, patient cooperation (obedient to open the mouth for laryngoscopy and the number of tries for laryngoscopy, patient comfort (remaining moveless, hallucination, nystagmus and salivation (need for aspiration before laryngoscopy. Results Direct laryngoscopy was performed successfully in all patients. One patient needed extra fentanyl and then laryngoscopy was performed successfully on the second try. All patients were cooperative enough during laryngoscopy. Hemodynamic changes more than 20% occurred in just one patient. Oxygen desaturation (spo2 Conclusions Subcutaneous Dissociative Conscious Sedation (sDCS as a new approach to airway is an acceptable and safe method for awake intubation and it can be suggested as a noninvasive substitute of low complication rate for regional airway

Limitations of potentiometric oxygen sensors operating at low oxygen levels

DEFF Research Database (Denmark)

Lund, Anders; Jacobsen, Torben; Hansen, Karin Vels

2011-01-01

The electrochemical processes that limit the range of oxygen partial pressures in which potentiometric oxygen sensors can be used, were analysed using a theoretical and an experimental approach. Electrochemical impedance spectroscopy was performed on porous Pt/yttria stabilised zirconia (YSZ......) electrodes between 10−6 and 0.2 bar and at temperatures between 500 and 950 °C. The flow of oxide ions and electron holes through a sensor cell, with a YSZ electrolyte, were calculated under similar conditions. The oxygen permeation of the sensor cell was insignificant at an oxygen partial pressure of 10......−6 bar for an inlet flow rate higher than 2 L h−1 between 600 and 800 °C. The polarisation resistance measured between 10−6 and 10−4 bar was found to be inversely proportional to the oxygen partial pressure, nearly temperature independent and inversely proportional to the inlet gas flow rate, which shows...

Ionic conductivity ageing investigation of 1Ce10ScSZ in different partial pressures of oxygen

DEFF Research Database (Denmark)

Omar, Shobit; Belda, Adriana; Escardino, Agustín

2011-01-01

The conductivity and its ageing behaviour has been determined for zirconia co-doped with 10 mol% of Sc2O3 and 1 mol% CeO2 in different partial pressures of oxygen at 600 °C. After 3000 h, samples kept in air, in a humidified mixture of H2/N2 and in humidified H2 exhibited loss in the ionic...

Why is the partial oxygen pressure of human tissues a crucial parameter? Small molecules and hypoxia

Science.gov (United States)

Carreau, Aude; Hafny-Rahbi, Bouchra El; Matejuk, Agata; Grillon, Catherine; Kieda, Claudine

2011-01-01

Abstract Oxygen supply and diffusion into tissues are necessary for survival. The oxygen partial pressure (pO2), which is a key component of the physiological state of an organ, results from the balance between oxygen delivery and its consumption. In mammals, oxygen is transported by red blood cells circulating in a well-organized vasculature. Oxygen delivery is dependent on the metabolic requirements and functional status of each organ. Consequently, in a physiological condition, organ and tissue are characterized by their own unique ‘tissue normoxia’ or ‘physioxia’ status. Tissue oxygenation is severely disturbed during pathological conditions such as cancer, diabetes, coronary heart disease, stroke, etc., which are associated with decrease in pO2, i.e. ‘hypoxia’. In this review, we present an array of methods currently used for assessing tissue oxygenation. We show that hypoxia is marked during tumour development and has strong consequences for oxygenation and its influence upon chemotherapy efficiency. Then we compare this to physiological pO2 values of human organs. Finally we evaluate consequences of physioxia on cell activity and its molecular modulations. More importantly we emphasize the discrepancy between in vivo and in vitro tissue and cells oxygen status which can have detrimental effects on experimental outcome. It appears that the values corresponding to the physioxia are ranging between 11% and 1% O2 whereas current in vitro experimentations are usually performed in 19.95% O2, an artificial context as far as oxygen balance is concerned. It is important to realize that most of the experiments performed in so-called normoxia might be dangerously misleading. PMID:21251211

Effect of low oxygen partial pressure to the bumblebee respiration; Naruhanabachi ni okeru taikichu sanso bun'atsu henka no kokyu ni oyobosu eikyo

Energy Technology Data Exchange (ETDEWEB)

Komai, Y. [Japan Science and Technology Corp., Tokyo (Japan)

1999-06-25

Insects augment oxygen supply using convective transport during flight in two ways: with deforming tracheae by surrounding muscles movement (muscle pumping) and with contracting air sacs by exoskeleton movement (abdominal or thoracic pumping). However, because induced flow inside tracheae is difficult to measure, it is not known how the convective transport actually contributes. By comparison between direct measurement of oxygen partial pressure in a flight muscle based on electrochemical method and flight/ventilation activities in a bumblebee, Bumbus hypocrita hypocruta, a method was developed for estimating gas transport efficiency. Oxygen partial pressure, P{sub 02}, in the bee periodically fluctuated with discontinuous abdominal movement in normal air. While the P{sub 02} strongly varied among individuals in normal air, the P{sub 02} took a unique value in oxygen poor air ({<=}8%). By enhancing ventilation, the bee could respire in an oxygen poor atmosphere up to 2%. Furthermore, the bee could fly in an atmosphere of 6%, in which the P{sub 02} decreased to 0.7%. Estimated efficiency of the gas transport increases with atmospheric oxygen concentration decreases. (author)

Elucidating mechanisms for insect body size: partial support for the oxygen-dependent induction of moulting hypothesis.

Science.gov (United States)

Kivelä, Sami M; Viinamäki, Sonja; Keret, Netta; Gotthard, Karl; Hohtola, Esa; Välimäki, Panu

2018-01-25

Body size is a key life history trait, and knowledge of its mechanistic basis is crucial in life history biology. Such knowledge is accumulating for holometabolous insects, whose growth is characterised and body size affected by moulting. According to the oxygen-dependent induction of moulting (ODIM) hypothesis, moult is induced at a critical mass at which oxygen demand of growing tissues overrides the supply from the tracheal respiratory system, which principally grows only at moults. Support for the ODIM hypothesis is controversial, partly because of a lack of proper data to explicitly test the hypothesis. The ODIM hypothesis predicts that the critical mass is positively correlated with oxygen partial pressure ( P O 2 ) and negatively with temperature. To resolve the controversy that surrounds the ODIM hypothesis, we rigorously test these predictions by exposing penultimate-instar Orthosia gothica (Lepidoptera: Noctuidae) larvae to temperature and moderate P O 2  manipulations in a factorial experiment. The relative mass increment in the focal instar increased along with increasing P O 2 , as predicted, but there was only weak suggestive evidence of the temperature effect. Probably owing to a high measurement error in the trait, the effect of P O 2  on the critical mass was sex specific; high P O 2  had a positive effect only in females, whereas low P O 2  had a negative effect only in males. Critical mass was independent of temperature. Support for the ODIM hypothesis is partial because of only suggestive evidence of a temperature effect on moulting, but the role of oxygen in moult induction seems unambiguous. The ODIM mechanism thus seems worth considering in body size analyses. © 2018. Published by The Company of Biologists Ltd.

Influence of the oxygen partial pressure on the phase evolution during Bi-2212 wire melt processing

CERN Document Server

Scheuerlein, C.; Rikel, M.O.; Kadar, J.; Doerrer, C.; Di Michiel, M.; Ballarino, A.; Bottura, L.; Jiang, J.; Kametani, F.; Hellstrom, E.E.; Larbalestier, D.C.

2016-01-01

We have studied the influence of the oxygen partial pressure pO2 up to 5.5 bar on the phase changes that occur during melt processing of a state-of-the-art Bi-2212 multifilamentary wire. Phase changes have been monitored in situ by high energy synchrotron X-ray diffraction (XRD). We found that the stability of Bi-2212 phase is reduced with increasing pO2. For pO2>1 bar a significant amount of Bi-2212 phase decomposes upon heating in the range 400 to 650 °C. The extent of decomposition strongly increases with increasing pO2, and at pO2=5.5 bar Bi-2212 decomposes completely in the solid state. Textured Bi-2212 can be formed during solidification when pO2 is reduced to 0.45 bar when the precursor is molten. Since the formation of current limiting second phases is very sensitive to pO2 when it exceeds 1 bar, we recommend to reduce the oxygen partial pressure below the commonly used pO2=1 bar, in order to increase the pO2 margins and to make the overpressure process more robust.

Effects of inoculum type and bulk dissolved oxygen concentration on achieving partial nitrification by entrapped-cell-based reactors.

Science.gov (United States)

Rongsayamanont, Chaiwat; Limpiyakorn, Tawan; Khan, Eakalak

2014-07-01

An entrapment of nitrifiers into gel matrix is employed as a tool to fulfill partial nitrification under non-limiting dissolved oxygen (DO) concentrations in bulk solutions. This study aims to clarify which of these two attributes, inoculum type and DO concentration in bulk solutions, is the decisive factor for partial nitrification in an entrapped-cell based system. Four polyvinyl alcohol entrapped inocula were prepared to have different proportions of nitrite-oxidizing bacteria (NOB) and nitrite-oxidizing activity. At a DO concentration of 3 mg l(-1), the number of active NOB cells in an inoculum was the decisive factor for partial nitrification enhancement. However, when the DO concentration was reduced to 2 mg l(-1), all entrapped cell inocula showed similar degrees of partial nitrification. The results suggested that with the lower bulk DO concentration, the preparation of entrapped cell inocula is not useful as the DO level becomes the decisive factor for achieving partial nitrification. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Case of Spontaneous Pneumomediastinum with Subcutaneous Emphysema in Children

Directory of Open Access Journals (Sweden)

Said Benlamkaddem

2018-02-01

Full Text Available Spontaneous pneumomediastinum is defined as free air or gas contained within the mediastinum, which almost invariably originates from the alveolar space or the conducting airways. It is rare in pediatric patients; however, occasional cases are reported to result from forced Valsalva’s maneuver due to cough, emesis, a first attack of wheeze, or asthma exacerbations. We report the case of a 7-year-old previously healthy girl, with a history of persistent dry cough one day before, who was brought to our unit with face, neck and chest swelling. The chest X-ray and computed tomography (CT scan showed subcutaneous emphysema with pneumomediastinum and pneumopericardium without evidence of the origin of this air leak. Laboratory tests and the bronchoscopy were normal. The patient was admitted in the pediatric critical care and received noninvasive monitoring, analgesia, oxygen, and omeprazole as a prophylaxis for a gastric ulcer. The patient improved, subcutaneous emphysema resolved, and she was discharged on the third day.

Why is the partial oxygen pressure of human tissues a crucial parameter? Small molecules and hypoxia.

Science.gov (United States)

Carreau, Aude; El Hafny-Rahbi, Bouchra; Matejuk, Agata; Grillon, Catherine; Kieda, Claudine

2011-06-01

Oxygen supply and diffusion into tissues are necessary for survival. The oxygen partial pressure (pO(2)), which is a key component of the physiological state of an organ, results from the balance between oxygen delivery and its consumption. In mammals, oxygen is transported by red blood cells circulating in a well-organized vasculature. Oxygen delivery is dependent on the metabolic requirements and functional status of each organ. Consequently, in a physiological condition, organ and tissue are characterized by their own unique 'tissue normoxia' or 'physioxia' status. Tissue oxygenation is severely disturbed during pathological conditions such as cancer, diabetes, coronary heart disease, stroke, etc., which are associated with decrease in pO(2), i.e. 'hypoxia'. In this review, we present an array of methods currently used for assessing tissue oxygenation. We show that hypoxia is marked during tumour development and has strong consequences for oxygenation and its influence upon chemotherapy efficiency. Then we compare this to physiological pO(2) values of human organs. Finally we evaluate consequences of physioxia on cell activity and its molecular modulations. More importantly we emphasize the discrepancy between in vivo and in vitro tissue and cells oxygen status which can have detrimental effects on experimental outcome. It appears that the values corresponding to the physioxia are ranging between 11% and 1% O(2) whereas current in vitro experimentations are usually performed in 19.95% O(2), an artificial context as far as oxygen balance is concerned. It is important to realize that most of the experiments performed in so-called normoxia might be dangerously misleading. © 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

Simultaneous imaging of cerebral partial pressure of oxygen and blood flow during functional activation and cortical spreading depression

Science.gov (United States)

Sakadžić, Sava; Yuan, Shuai; Dilekoz, Ergin; Ruvinskaya, Svetlana; Vinogradov, Sergei A.; Ayata, Cenk; Boas, David A.

2009-01-01

We developed a novel imaging technique that provides real-time two-dimensional maps of the absolute partial pressure of oxygen and relative cerebral blood flow in rats by combining phosphorescence lifetime imaging with laser speckle contrast imaging. Direct measurement of blood oxygenation based on phosphorescence lifetime is not significantly affected by changes in the optical parameters of the tissue during the experiment. The potential of the system as a novel tool for quantitative analysis of the dynamic delivery of oxygen to support brain metabolism was demonstrated in rats by imaging cortical responses to forepaw stimulation and the propagation of cortical spreading depression waves. This new instrument will enable further study of neurovascular coupling in normal and diseased brain. PMID:19340106

Systematic trends of YBa2Cu3O7-δ thin films post annealed in low oxygen partial pressures

International Nuclear Information System (INIS)

Hou, S.Y.; Phillips, J.M.; Werder, D.J.; Tiefel, T.H.; Marshall, J.H.; Siegal, M.P.

1994-01-01

Systematic studies have been performed on 1000 A YBa 2 Cu 3 O 7-δ films produced by the BaF 2 process and annealed in an oxygen partial pressure (p O 2 ) range from 740 Torr to 10 mTorr as well as a temperature range from 600 to 1050 degree C. The results show that while high quality films can be annealed in a wide range of oxygen partial pressure, they have different characteristics. In general, crystalline quality and T c are optimized at high p O 2 and high annealing temperature, while strong flux pinning and low normal state resistivity are achieved at lower values of both variables. Under optimized low p O 2 conditions, an ion channeling χ min of 6% is obtained on films as thick as 5000 A. This study will serve as a useful guide to tailoring film properties to the application at hand

Frontal subcutaneous blood flow, and epi- and subcutaneous temperatures during scalp cooling in normal man

DEFF Research Database (Denmark)

Bülow, J; Friberg, L; Gaardsting, O

1985-01-01

Cooling of the scalp has been found to prevent hair loss following cytostatic treatment, but in order to obtain the hair preserving effect the subcutaneous temperature has to be reduced below 22 degrees C. In order to establish the relationship between epicutaneous and subcutaneous temperatures...... epicutaneous and subcutaneous temperatures could be demonstrated with the regression equation: s = 0.9 c + 4.9 (r = 0.99). In eight of the 10 subjects the subcutaneous temperature could be reduced below 22 degrees C with the applied technique. It is concluded that the hair preserving effect of scalp cooling...

Internal-reference solid-electrolyte oxygen sensor

International Nuclear Information System (INIS)

Haaland, D.M.

1977-01-01

A new solid-electrolyte oxygen sensor has been developed that eliminates the conventional oxygen reference in previous solid-electrolyte oxygen sensor designs and is, therefore, ideally suited as an insertion device for remote oxygen monitoring applications. It is constructed with two cells of stabilized zirconia sealed into a small unit using a new high-temperature platinum-zirconia seal. One electrochemical cell monitors the ratio of oxygen partial pressures inside and outside the sensor while the other solid-electrolyte cell is used for quantitative electrochemical pumping of oxygen. The internal oxygen reference is generated by initially pumping all oxygen out of the known internal volume of the sensor and then quantitatively pumping oxygen back in until oxygen partial pressures are equal inside and out. This information is used with the ideal gas law to calculate oxygen partial pressures. Tests were conducted from 400 to 1000 0 C in mixtures of oxygen and nitrogen spanning approximately 0.2 to 21 percent oxygen concentration range. Sensors with sputtered platinum and porous platinum paste electrodes were compared

Measurement of alveolar oxygen partial pressure in the rat lung using Carr-Purcell-Meiboom-Gill spin-spin relaxation times of hyperpolarized 3He and 129Xe at 74 mT.

Science.gov (United States)

Kraayvanger, Ryan J; Bidinosti, Christopher P; Dominguez-Viqueira, William; Parra-Robles, Juan; Fox, Matthew; Lam, Wilfred W; Santyr, Giles E

2010-11-01

Regional measurement of alveolar oxygen partial pressure can be obtained from the relaxation rates of hyperpolarized noble gases, (3) He and (129) Xe, in the lungs. Recently, it has been demonstrated that measurements of alveolar oxygen partial pressure can be obtained using the spin-spin relaxation rate (R(2) ) of (3) He at low magnetic field strengths (oxygen partial pressure measurements based on Carr-Purcell-Meiboom-Gill R(2) values of hyperpolarized (3) He and (129) Xe in vitro and in vivo in the rat lung at low magnetic field strength (74 mT) are presented. In vitro spin-spin relaxivity constants for (3) He and (129) Xe were determined to be (5.2 ± 0.6) × 10(-6) Pa(-1) sec(-1) and (7.3 ± 0.4) × 10(-6) Pa(-1) s(-1) compared with spin-lattice relaxivity constants of (4.0 ± 0.4) × 10(-6) Pa(-1) s(-1) and (4.3 ± 1.3) × 10(-6) Pa(-1) s(-1), respectively. In vivo experimental measurements of alveolar oxygen partial pressure using (3) He in whole rat lung show good agreement (r(2) = 0.973) with predictions based on lung volumes and ventilation parameters. For (129) Xe, multicomponent relaxation was observed with one component exhibiting an increase in R(2) with decreasing alveolar oxygen partial pressure. Copyright © 2010 Wiley-Liss, Inc.

Direct Synthesis of Methanol by Partial Oxidation of Methane with Oxygen over Cobalt Modified Mesoporous H-ZSM-5 Catalyst

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Yuni Krisyuningsih Krisnandi

2015-11-01

Full Text Available Partial oxidation of methane over mesoporous catalyst cobalt modified H-ZSM-5 has been carried out. Mesoporous Na-ZSM-5 (Si/Al = 35.4 was successfully synthesized using double template method which has high surface area (450 m2/g and average pore diameter distribution of 1.9 nm. The as-synthesized Na-ZSM-5 was converted to H-ZSM-5 through multi-exchange treatment with ammonium ion solution, causing decreased crystallinity and surface area, but increased porous diameter, due to dealumination during treatment process. Moreover, H-ZSM-5 was loaded with cobalt (Co = 2.5% w by the incipient impregnation method and calcined at 550 °C. Partial oxidation of methane was performed in the batch reactor with 0.75 bar methane and 2 bar of nitrogen (with impurities of 0.5% oxygen as the input at various reaction time (30, 60 and 120 min. The reaction results show that cobalt species in catalyst has an important role, because H-ZSM-5 cannot produce methanol in partial oxidation of methane. The presence of molecular oxygen increased the percentage of methanol yield. The reaction is time-dependent with the highest methanol yield (79% was acquired using Co/H-ZSM-5 catalyst for 60 min.

Brain tissue partial pressure of oxygen predicts the outcome of severe traumatic brain injury under mild hypothermia treatment

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Sun H

2016-08-01

Full Text Available Hongtao Sun,1,* Maohua Zheng,2,* Yanmin Wang,1 Yunfeng Diao,1 Wanyong Zhao,1 Zhengjun Wei1 1Sixth Department of Neurosurgery, Affiliated Hospital of Logistics University of People’s Armed Police Force, Tianjin, 2Department of Neurosurgery, The First Hospital of Lanzhou University, Lanzhou, People’s Republic of China *These authors contributed equally to this work Objective: The aim of this study was to investigate the clinical significance and changes of brain tissue partial pressure of oxygen (PbtO2 in the course of mild hypothermia treatment (MHT for treating severe traumatic brain injury (sTBI. Methods: There were 68 cases with sTBI undergoing MHT. PbtO2, intracranial pressure (ICP, jugular venous oxygen saturation (SjvO2, and cerebral perfusion pressure (CPP were continuously monitored, and clinical outcomes were evaluated using the Glasgow Outcome Scale score. Results: Of 68 patients with sTBI, PbtO2, SjvO2, and CPP were obviously increased, but decreased ICP level was observed throughout the MHT. PbtO2 and ICP were negatively linearly correlated, while there was a positive linear correlation between PbtO2 and SjvO2. Monitoring CPP and SjvO2 was performed under normal circumstances, and a large proportion of patients were detected with low PbtO2. Decreased PbtO2 was also found after MHT. Conclusion: Continuous PbtO2 monitoring could be introduced to evaluate the condition of regional cerebral oxygen metabolism, thereby guiding the clinical treatment and predicting the outcome. Keywords: severe traumatic brain injury, hypothermia, brain tissue partial pressure of oxygen, therapy

Microvascular oxygen partial pressure during hyperbaric oxygen in diabetic rat skeletal muscle.

Science.gov (United States)

Yamakoshi, Kohei; Yagishita, Kazuyoshi; Tsuchimochi, Hirotsugu; Inagaki, Tadakatsu; Shirai, Mikiyasu; Poole, David C; Kano, Yutaka

2015-12-15

Hyperbaric oxygen (HBO) is a major therapeutic treatment for ischemic ulcerations that perforate skin and underlying muscle in diabetic patients. These lesions do not heal effectively, in part, because of the hypoxic microvascular O2 partial pressures (PmvO2 ) resulting from diabetes-induced cardiovascular dysfunction, which alters the dynamic balance between O2 delivery (Q̇o2) and utilization (V̇o2) rates. We tested the hypothesis that HBO in diabetic muscle would exacerbate the hyperoxic PmvO2 dynamics due, in part, to a reduction or slowing of the cardiovascular, sympathetic nervous, and respiratory system responses to acute HBO exposure. Adult male Wistar rats were divided randomly into diabetic (DIA: streptozotocin ip) and healthy (control) groups. A small animal hyperbaric chamber was pressurized with oxygen (100% O2) to 3.0 atmospheres absolute (ATA) at 0.2 ATA/min. Phosphorescence quenching techniques were used to measure PmvO2 in tibialis anterior muscle of anesthetized rats during HBO. Lumbar sympathetic nerve activity (LSNA), heart rate (HR), and respiratory rate (RR) were measured electrophysiologically. During the normobaric hyperoxia and HBO, DIA tibialis anterior PmvO2 increased faster (mean response time, CONT 78 ± 8, DIA 55 ± 8 s, P < 0.05) than CONT. Subsequently, PmvO2 remained elevated at similar levels in CONT and DIA muscles until normobaric normoxic recovery where the DIA PmvO2 retained its hyperoxic level longer than CONT. Sympathetic nervous system and cardiac and respiratory responses to HBO were slower in DIA vs. CONT. Specifically the mean response times for RR (CONT: 6 ± 1 s, DIA: 29 ± 4 s, P < 0.05), HR (CONT: 16 ± 1 s, DIA: 45 ± 5 s, P < 0.05), and LSNA (CONT: 140 ± 16 s, DIA: 247 ± 34 s, P < 0.05) were greater following HBO onset in DIA than CONT. HBO treatment increases tibialis anterior muscle PmvO2 more rapidly and for a longer duration in DIA than CONT, but not to a greater level. Whereas respiratory, cardiovascular

Preretinal partial pressure of oxygen gradients before and after experimental pars plana vitrectomy.

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Petropoulos, Ioannis K; Pournaras, Jean-Antoine C; Stangos, Alexandros N; Pournaras, Constantin J

2013-01-01

To evaluate preretinal partial pressure of oxygen (PO2) gradients before and after experimental pars plana vitrectomy. Arteriolar, venous, and intervascular preretinal PO2 gradients were recorded in 7 minipigs during slow withdrawal of oxygen-sensitive microelectrodes (10-μm tip diameter) from the vitreoretinal interface to 2 mm into the vitreous cavity. Recordings were repeated after pars plana vitrectomy and balanced salt solution (BSS) intraocular perfusion. Arteriolar, venous, and intervascular preretinal PO2 at the vitreoretinal interface were 62.3 ± 13.8, 22.5 ± 3.3, and 17.0 ± 7.5 mmHg, respectively, before vitrectomy; 97.7 ± 19.9, 40.0 ± 21.9, and 56.3 ± 28.4 mmHg, respectively, immediately after vitrectomy; and 59.0 ± 27.4, 25.2 ± 3.0, and 21.5 ± 4.5 mmHg, respectively, 2½ hours after interruption of BSS perfusion. PO2 2 mm from the vitreoretinal interface was 28.4 ± 3.6 mmHg before vitrectomy; 151.8 ± 4.5 mmHg immediately after vitrectomy; and 34.8 ± 4.1 mmHg 2½ hours after interruption of BSS perfusion. PO2 gradients were still present after vitrectomy, with the same patterns as before vitrectomy. Preretinal PO2 gradients are not eliminated after pars plana vitrectomy. During BSS perfusion, vitreous cavity PO2 is very high. Interruption of BSS perfusion evokes progressive equilibration of vitreous cavity PO2 with concomitant progressive return of preretinal PO2 gradients to their previtrectomy patterns. This indicates that preretinal diffusion of oxygen is not altered after vitrectomy. The beneficial effect of vitrectomy in ischemic retinal diseases or macular edema may be related to other mechanisms, such as increased oxygen convection currents or removal of growth factors and cytokines secreted in the vitreous.

Role of oxygen partial pressure in microstructural development and properties of YBCO superconductors

International Nuclear Information System (INIS)

Singh, J.P.; Guttschow, R.; Dusek, J.T.; Poeppel, R.B.

1991-01-01

Results are presented for the effect of oxygen partial pressure (pO 2 ) on the sintered density and microstructure of YBCO superconductors. Extruded YBCO wires were sintered at 910C at different values of pO 2 . Generally, the density increased with decreasing pO 2 , and a density of 91% was achieved at pO 2 = 0.01 atm. Wires sintered at pO 2 = 0.01 atm had a fine microstructure with an average grain size of ∼3 μm and an average strength of 191 MPa. The high strength is due to the small grain size, which causes a decrease in residual tensile stress because of grain anisotropy

Subcutaneous granuloma annulare: radiologic appearance

International Nuclear Information System (INIS)

Kransdorf, M.J.; Murphey, M.D.; Temple, H.T.

1998-01-01

Objective. Granuloma annulare is an uncommon benign inflammatory dermatosis characterized by the formation of dermal papules with a tendency to form rings. There are several clinically distinct forms. The subcutaneous form is the most frequently encountered by radiologists, with the lesion presenting as a superficial mass. There are only a few scattered reports of the imaging appearance of this entity in the literature. We report the radiologic appearance of five cases of subcutaneous granuloma annulare. Design and patients. The radiologic images of five patients (three male, two female) with subcutaneous granuloma annulare were retrospectively studied. Mean patient age was 6.4 years (range, 2-13 years). The lesions occurred in the lower leg (two), foot, forearm, and hand. MR images were available for all lesions, gadolinium-enhanced imaging in three cases, radiographs in four, and bone scintigraphy in one. Results. Radiographs showed unmineralized nodular masses localized to the subcutaneous adipose tissue. The size range, in greatest dimension on imaging studies, was 1-4 cm. MR images show a mass with relatively decreased signal intensity on all pulse sequences, with variable but generally relatively well defined margins. There was extensive diffuse enhancement following gadolinium administration. Conclusion. The radiologic appearance of subcutaneous granuloma annulare is characteristic, typically demonstrating a nodular soft-tissue mass involving the subcutaneous adipose tissue. MR images show a mass with relatively decreased signal intensity on all pulse sequences and variable but generally well defined margins. There is extensive diffuse enhancement following gadolinium administration. Radiographs show a soft-tissue mass or soft-tissue swelling without evidence of bone involvement or mineralization. This radiologic appearance in a young individual is highly suggestive of subcutaneous granuloma annulare. (orig.)

Closed Loop Control of Oxygen Delivery and Oxygen Generation

Science.gov (United States)

2017-08-01

were used for this study and were connected via a USB cable to allow communication. The ventilator was modified to allow closed loop control of oxygen...connected via a USB cable to allow communication. The ventilator was modified to allow closed loop control of oxygen based on the oxygen saturation...2017-4119, 28 Aug 2017. oximetry (SpO2) and intermittent arterial blood sampling for arterial oxygen tension (partial pressure of oxygen [PaO2]) and

Oxygen partial pressure: a key to alloying and discovery in metal oxide--metal eutectic systems

International Nuclear Information System (INIS)

Holder, J.D.; Clark, G.W.; Oliver, B.F.

1978-01-01

Control of oxygen partial pressure is essential in the directional solidification of oxide--metal eutectic composites by techniques involving gas-solid and gas-liquid interactions. The existence of end components in the eutectic composite is Po 2 sensitive as are melt stoichiometry, solid phase compositions, and vapor losses due to oxidation-volatilization. Simple criteria are postulated which can aid the experimentalist in selecting the proper gas mixture for oxide--metal eutectic composite growth. The Cr 2 O 3 --Mo--Cr systems was used to verify certain aspects of the proposed criteria

Fuel cell serves as oxygen level detector

Science.gov (United States)

1965-01-01

Monitoring the oxygen level in the air is accomplished by a fuel cell detector whose voltage output is proportional to the partial pressure of oxygen in the sampled gas. The relationship between output voltage and partial pressure of oxygen can be calibrated.

Subcutaneous sarcoidosis associated with sarcoid tenosynovitis.

Science.gov (United States)

Enzenauer, R J; Waterhouse, W J; West, S G

1996-10-01

Subcutaneous sarcoidosis and sarcoid tenosynovitis are unusual manifestations of systemic sarcoidosis. We report two Japanese women with disseminated sarcoidosis presenting with subcutaneous and tenosynovial involvement demonstrated by computed tomography and magnetic resonance imaging. Sarcoidosis must be considered in the differential diagnosis of unexplained subcutaneous nodulosis or tenosynovitis in patients with or without a previous diagnosis of sarcoidosis.

The partial pressure of oxygen affects biomarkers of oxidative stress in cultured rainbow trout (Oncorhynchus mykiss) hepatocytes.

Science.gov (United States)

Finne, E F; Olsvik, P A; Berntssen, M H G; Hylland, K; Tollefsen, K E

2008-09-01

Oxidative stress, the imbalance between production of reactive oxygen species and the cellular detoxification of these reactive compounds, is believed to be involved in the pathology of various diseases. Several biomarkers for oxidative stress have been proposed to serve as tools in toxicological and ecotoxicological research. Not only may exposure to various pro-oxidants create conditions of cellular oxidative stress, but hyperoxic conditions may also increase the production of reactive oxygen species. The objective of the current study was to determine the extent to which differences in oxygen partial pressure would affect biomarkers of oxidative stress in a primary culture of hepatocytes from rainbow trout (Oncorhynchus mykiss). Membrane integrity, metabolic activity, levels of total and oxidized glutathione (tGSH/GSSG) was determined, as well as mRNA expression levels of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R), gamma-glutamyl-cystein synthetase (GCS) and thioredoxin (TRX). The results show that different biomarkers of oxidative stress are affected when the cell culture is exposed to atmospheric oxygen, and that changes such as increased GSSG content and induction of GSSG-R and GSH-Px can be reduced by culturing the cells under lower oxygen tension. Oxygen tension may thus influence results of in vitro based cell research and is particularly important when assessing parameters in the antioxidant defence system. Further research is needed to establish the magnitude of this effect in different cellular systems.

Influence of oxygen, partial vacuum, temperature and relative humidity combined with gamma radiation on the mosquito, culex pipiens complex L

International Nuclear Information System (INIS)

Abdel-rahman, A.M.; Wakid, A.M.; Hafez, M.; Hafez, M.K.

1992-01-01

Treatment of pupae of culex pipiens L. With gamma radiation only (60 Gy) caused 47-57.83% decrease in adult emergence. Treatment with oxygen or partial vacuum (0.1 torr) for one hour caused insignificant decrease in adult emergence. This decrease became significant when the exposure time was prolonged to two hours. Exposure of pupae to 10 degree C for one or two hours or to 31% R.H. for 3 hours caused highly significant decrease in adult emergence. When radiation was combined with any of the factors applied, a pronounced decrease in adult emergence was recorded, especially when combined with 31% R.H. for 3 hours. In all treatments, females lived longer than males. Exposure of pupae to oxygen gas or 31% R.H. Only, prolonged the life span of the produced adults, while exposure to radiation, partial vacuum or low temperature only shortened it. This effect was also observed when gamma radiation was combined with these two factors. 4 fig.,1 tab

[The influence of low partial oxygen pressure on the biolodical process of mesenchymal stromal cells].

Science.gov (United States)

Berezovskyĭ, V Ia; Plotnikova, L M; Vesel'skyĭ, S P; Litovka, I H

2014-01-01

The influence of low partial oxygen pressure (Po2) on the amino acid composition in culture medium of human mesenchymal stromal cell (MSC) lines 4BL has been studied. At 23 mm Hg (3% oxygen), a significant decrease (by 31%) in the concentration of proline and hydroxyproline was registered. Under these conditions, the concentration of serine and aspartic acid decreased by 45% compared to the control. Maximum consumption of free amino acids from the culture medium required for the synthesis of collagen (proline and hydroxyproline by 42%, serine and aspartic acid by 62%) was observed at a gas-phase Po2 of 38 mm Hg (5% O2). At Po2 76 mm Hg (10% O2), a lack of amino acids proline and hydroxyproline was only 21%, while that of glutamine and alanine amounted 12% compared to the control. This intensity ratio of consumption of amino acids may indicate that the maximum of MSC vital functions occurs at Po2 38 mm Hg.

Two-photon high-resolution measurement of partial pressure of oxygen in cerebral vasculature and tissue.

Science.gov (United States)

Sakadzić, Sava; Roussakis, Emmanuel; Yaseen, Mohammad A; Mandeville, Emiri T; Srinivasan, Vivek J; Arai, Ken; Ruvinskaya, Svetlana; Devor, Anna; Lo, Eng H; Vinogradov, Sergei A; Boas, David A

2010-09-01

Measurements of oxygen partial pressure (pO(2)) with high temporal and spatial resolution in three dimensions is crucial for understanding oxygen delivery and consumption in normal and diseased brain. Among existing pO(2) measurement methods, phosphorescence quenching is optimally suited for the task. However, previous attempts to couple phosphorescence with two-photon laser scanning microscopy have faced substantial difficulties because of extremely low two-photon absorption cross-sections of conventional phosphorescent probes. Here we report to our knowledge the first practical in vivo two-photon high-resolution pO(2) measurements in small rodents' cortical microvasculature and tissue, made possible by combining an optimized imaging system with a two-photon-enhanced phosphorescent nanoprobe. The method features a measurement depth of up to 250 microm, sub-second temporal resolution and requires low probe concentration. The properties of the probe allowed for direct high-resolution measurement of cortical extravascular (tissue) pO(2), opening many possibilities for functional metabolic brain studies.

Two-photon high-resolution measurement of partial pressure of oxygen in cerebral vasculature and tissue

Science.gov (United States)

Sakadžić, Sava; Roussakis, Emmanuel; Yaseen, Mohammad A.; Mandeville, Emiri T.; Srinivasan, Vivek J.; Arai, Ken; Ruvinskaya, Svetlana; Devor, Anna; Lo, Eng H.; Vinogradov, Sergei A.; Boas, David A.

2010-01-01

The ability to measure oxygen partial pressure (pO2) with high temporal and spatial resolution in three dimensions is crucial for understanding oxygen delivery and consumption in normal and diseased brain. Among existing pO2 measurement methods, phosphorescence quenching is optimally suited for the task. However, previous attempts to couple phosphorescence with two-photon laser scanning microscopy have faced substantial difficulties because of extremely low two-photon absorption cross-sections of conventional phosphorescent probes. Here, we report the first practical in vivo two-photon high-resolution pO2 measurements in small rodents’ cortical microvasculature and tissue, made possible by combining an optimized imaging system with a two-photon-enhanced phosphorescent nanoprobe. The method features a measurement depth of up to 250 µm, sub-second temporal resolution and requires low probe concentration. Most importantly, the properties of the probe allowed for the first direct high-resolution measurement of cortical extravascular (tissue) pO2, opening numerous possibilities for functional metabolic brain studies. PMID:20693997

High oxygen partial pressure increases photodynamic effect on HeLa cell lines in the presence of chloraluminium phthalocyanine.

Science.gov (United States)

Bajgar, Robert; Kolarova, Hana; Bolek, Lukas; Binder, Svatopluk; Pizova, Klara; Hanakova, Adela

2014-08-01

Photodynamic therapy (PDT) is linked with oxidative damage of biomolecules causing significant impairment of essential cellular functions that lead to cell death. It is the reason why photodynamic therapy has found application in treatment of different oncological, cardiovascular, skin and eye diseases. Efficacy of PDT depends on combined action of three components; sensitizer, light and oxygen. In the present study, we examined whether higher partial pressure of oxygen increases lethality in HeLa cell lines exposed to light in the presence of chloraluminium phthalocyanine disulfonate (ClAlPcS2). ClAlPcS2- sensitized HeLa cells incubated under different oxygen conditions were exposed to PDT. Production of singlet oxygen ((1)O2) and other forms of reactive oxygen species (ROS) as well as changes in mitochondrial membrane potential were determined by appropriately sensitive fluorescence probes. The effect of PDT on HeLa cell viability under different oxygen conditions was quantified using the standard methylthiazol tetrazolium (MTT) test. At the highest oxygen concentration of 28 ± 2 mg/l HeLa cells were significantly more sensitive to light-activated ClAlPcS2 (EC50=0.29 ± 0.05 μM) in comparison to cells incubated at lower oxygen concentrations of 8 ± 0.5 and 0.5 ± 0.1 mg/l, where the half maximal effective concentration was 0.42 ± 0.06 μM and 0.94 ± 0.14 μM, respectively. Moreover, we found that the higher presence of oxygen is accompanied with higher production of singlet oxygen, a higher rate of type II photodynamic reactions, and a significant drop in the mitochondrial membrane potential. These results demonstrate that the photodynamic effect in cervical cancer cells utilizing ClAlPcS2 significantly depends on oxygen level. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Structure and Electrical Properties of NdBa2Cu3Oy Thin Films by Laser Ablation at Low Oxygen Partial Pressure

DEFF Research Database (Denmark)

Mozhaev, Peter B.; Mozhaeva, Julia; Khoryushin, Alexey

2017-01-01

in the film can be suppressed by an increase of the deposition temperature or by a decrease of the oxygen partial pressure during deposition. The presence of Nd/Ba disorder during deposition stimulates the introduction of oxygen into the growing film. A simple model is proposed for estimation of oxygen......A deposition process for NdBa2Cu3Oy thin films by laser ablation at decreased deposition temperature was developed using substitution of oxygen with argon in the chamber during deposition. A low deposition rate is the crucial factor to obtain high-quality NBCO films. The Nd/Ba cation disorder...... contents in the film using structural parameters measured with XRD techniques. Studies of the post-deposition annealing process showed ordering of the Nd/Ba sub-lattice and intense oxygen in- and out-diffusion. The temperature of the post-deposition annealing step should be chosen low enough (∼400 °C...

Recombinant human hyaluronidase-enabled subcutaneous pediatric rehydration.

Science.gov (United States)

Allen, Coburn H; Etzwiler, Lisa S; Miller, Melissa K; Maher, George; Mace, Sharon; Hostetler, Mark A; Smith, Sharon R; Reinhardt, Neil; Hahn, Barry; Harb, George

2009-11-01

The Increased Flow Utilizing Subcutaneously-Enabled (INFUSE)-Pediatric Rehydration Study was designed to assess efficacy, safety, and clinical utility of recombinant human hyaluronidase (rHuPH20)-facilitated subcutaneous rehydration in children 2 months to 10 years of age. Patients with mild/moderate dehydration requiring parenteral treatment in US emergency departments were eligible for this phase IV, multicenter, single-arm study. They received subcutaneous injection of 1 mL rHuPH20 (150 U), followed by subcutaneous infusion of 20 mL/kg isotonic fluid over the first hour. Subcutaneous rehydration was continued as needed for up to 72 hours. Rehydration was deemed successful if it was attributed by the investigator primarily to subcutaneous fluid infusion and the child was discharged without requiring an alternative method of rehydration. Efficacy was evaluated in 51 patients (mean age: 1.9 years; mean weight: 11.2 kg). Initial subcutaneous catheter placement was achieved with 1 attempt for 46/51 (90.2%) of patients. Rehydration was successful for 43/51 (84.3%) of patients. Five patients (9.8%) were hospitalized but deemed to be rehydrated primarily through subcutaneous therapy, for a total of 48/51 (94.1%) of patients. No treatment-related systemic adverse events were reported, but 1 serious adverse event occurred (cellulitis at infusion site). Investigators found the procedure easy to perform for 96% of patients (49/51 patients), and 90% of parents (43/48 parents) were satisfied or very satisfied. rHuPH20-facilitated subcutaneous hydration seems to be safe and effective for young children with mild/moderate dehydration. Subcutaneous access is achieved easily, and the procedure is well accepted by clinicians and parents.

stausartikel: behandling af subcutane abscesser

DEFF Research Database (Denmark)

Hardgrib, Nina; Petersen, Klaus Kjær

2017-01-01

Simple subcutaneous abscesses are common, and we have examined the literature concerning the ideal treatment of subcutaneous abscesses. We recommend radical debridement with removal of all pus, the abscess wall and any necrosis. If primary suture is chosen, preoperative antibiotics should be admi...

Subcutaneous versus subcutaneous and intraperitoneal local anaesthetic in the management of post appendicectomy pain

International Nuclear Information System (INIS)

Qureshi, K.Z.; Gondal, Z.I.; Raza, A.

2014-01-01

To compare the efficacy of subcutaneous only and combined subcutaneous and peritoneal infiltration of 0.5% bupivacaine during appendicectomy for the management of early post operative pain. Study Design: Randomized controlled study. Place and Duration of Study: Department of Surgery, CMH Kohat from 13th December 2007 to 20th December 2008. Patients and Methods: Sixty patients of a cute appendicitis, divided into two groups of 30 each, were included in the study. Group A was given 0.5% bupivacaine subcutaneously, whereas group B was given the anaesthetic subcutaneously as well as intraperitoneally during appendectomy. Results: In group A, 24 (80%) were VAS (visual analoguescoring) 3 (uncomfortable) and 6 (20%) were VAS 2 (mild pain) whereas in study group B, 11 (36.6%) were VAS 3, 19 (63.3%) were VAS 2 and 19 (63.3%) were VAS 2 during 1st 12 hrs postoperatively (p=0.001). In 12-24 hrs post operatively, 15 (50%) patients were VAS 3 in group A and same number was VAS 2 and in group B, only 3 (10%) were in VAS 3 and 27 (90%) were VAS 2 (p=0.001). Conclusion: A combination of subcutaneous and peritoneal infiltration with bupivacaine is superior in relieving post appendectomy pain so patients require less dosage of analgesics in early post operative period along with early mobilization. (author)

The Effect of Sintering Oxygen Partial Pressure on a SmBiO3 Buffer Layer for Coated Conductors via Chemical Solution Deposition

Directory of Open Access Journals (Sweden)

Xiaolei Zhu

2016-10-01

Full Text Available The application of high-temperature YBa2Cu3O7−δ (YBCO superconducting material is a considerable prospect for the growing energy shortages. Here, SmBiO3 (SBO films were deposited on (100-orientated yttrium-stabilized zirconia (YSZ simple crystal substrates via the chemical solution deposition (CSD approach for coated conductors, and the effects of sintering oxygen partial pressure on SBO films were studied. The crystalline structures and surface morphologies of SBO films were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, and atomic force microscope (AFM. The optimized growth temperature, the intensity ratios of the SBO (200 peak to the SBO (111 peak, and the crystallinities of SBO films increased with the sintering oxygen partial pressure. The SEM and AFM images displayed a smooth and well-distributed surface in the argon atmosphere. The subsequent YBCO films with superconducting transition temperatures (Tc = 89.5 K, 90.2 K, and 86.2 K and critical current densities (Jc = 0.88 MA/cm2, 1.69 MA/cm2, and 0.09 MA/cm2; 77 K, self-field were deposited to further check the qualities of the SBO layer. These results indicated that sintering oxygen partial pressure had an effect on the epitaxial growth of the SBO buffer layer and YBCO superconducting properties. The experimental results may be a usable reference for the epitaxial growth of YBCO-coated conductors and other oxides.

[Observation on changes of oxygen partial pressure in the deep tissues along the large intestine meridian during acupuncture in healthy subjects].

Science.gov (United States)

Chen, Ming; Hu, Xiang-long; Wu, Zu-xing

2010-06-01

To observe changes of the partial oxygen pressure in the deep tissues along the Large Intestine Meridian (LIM) during acupuncture stimulation, so as to reveal the characteristics of energy metabolism in the tissues along the LIM. Thirty-one healthy volunteer subjects were enlisted in the present study. Partial oxygen pressure (POP) in the tissues (at a depth of about 1.5 cm) of acupoints Binao (LI 14), Shouwuli (LI 13), Shousanli (LI 10), 2 non-acupoints [the midpoints between Quchi (LI 11) and LI 14, and between Yangxi (LI 5) and LI 11) of the LIM, and 10 non-meridian points, 1.5-2.0 cm lateral and medial to each of the tested points of the LIM was detected before, during and after electroacupuncture (EA) stimulation of Hegu (LI 4) by using a tissue oxygen tension needle-like sensor. In normal condition, the POP values in the deep tissues along the LIM were significantly higher than those of the non-meridian control points on its bilateral sides. During and after EA of Hegu (LI 4), the POP levels decreased significantly in the deep tissues along the LIM in comparison with pre-EA (P 0.05). POP is significantly higher in the deep tissues along the LIM of healthy subjects under normal conditions, which can be downregulated by EA of Hegu (LI 4), suggesting an increase of both the utilization rate of oxygen and energy metabolism after EA.

The Relationship Between Oxygen Reserve Index and Arterial Partial Pressure of Oxygen During Surgery.

Science.gov (United States)

Applegate, Richard L; Dorotta, Ihab L; Wells, Briana; Juma, David; Applegate, Patricia M

2016-09-01

The use of intraoperative pulse oximetry (SpO2) enhances hypoxia detection and is associated with fewer perioperative hypoxic events. However, SpO2 may be reported as 98% when arterial partial pressure of oxygen (PaO2) is as low as 70 mm Hg. Therefore, SpO2 may not provide advance warning of falling arterial oxygenation until PaO2 approaches this level. Multiwave pulse co-oximetry can provide a calculated oxygen reserve index (ORI) that may add to information from pulse oximetry when SpO2 is >98%. This study evaluates the ORI to PaO2 relationship during surgery. We studied patients undergoing scheduled surgery in which arterial catheterization and intraoperative arterial blood gas analysis were planned. Data from multiple pulse co-oximetry sensors on each patient were continuously collected and stored on a research computer. Regression analysis was used to compare ORI with PaO2 obtained from each arterial blood gas measurement and changes in ORI with changes in PaO2 from sequential measurements. Linear mixed-effects regression models for repeated measures were then used to account for within-subject correlation across the repeatedly measured PaO2 and ORI and for the unequal time intervals of PaO2 determination over elapsed surgical time. Regression plots were inspected for ORI values corresponding to PaO2 of 100 and 150 mm Hg. ORI and PaO2 were compared using mixed-effects models with a subject-specific random intercept. ORI values and PaO2 measurements were obtained from intraoperative data collected from 106 patients. Regression analysis showed that the ORI to PaO2 relationship was stronger for PaO2 to 240 mm Hg (r = 0.536) than for PaO2 over 240 mm Hg (r = 0.0016). Measured PaO2 was ≥100 mm Hg for all ORI over 0.24. Measured PaO2 was ≥150 mm Hg in 96.6% of samples when ORI was over 0.55. A random intercept variance component linear mixed-effects model for repeated measures indicated that PaO2 was significantly related to ORI (β[95% confidence interval] = 0

Influence of partial pressure of oxygen in blood samples on measurement performance in glucose-oxidase-based systems for self-monitoring of blood glucose.

Science.gov (United States)

Baumstark, Annette; Schmid, Christina; Pleus, Stefan; Haug, Cornelia; Freckmann, Guido

2013-11-01

Partial pressure of oxygen (pO2) in blood samples can affect blood glucose (BG) measurements, particularly in systems that employ the glucose oxidase (GOx) enzyme reaction on test strips. In this study, we assessed the impact of different pO2 values on the performance of five GOx systems and one glucose dehydrogenase (GDH) system. Two of the GOx systems are labeled by the manufacturers to be sensitive to increased blood oxygen content, while the other three GOx systems are not. Aliquots of 20 venous samples were adjusted to the following pO2 values: oxygen sensitive. © 2013 Diabetes Technology Society.

Relations between pH, oxygen partial pressure and growth in cultured cell spheroids.

Science.gov (United States)

Carlsson, J; Acker, H

1988-11-15

The pH gradients, oxygen partial-pressure gradients and growth curves were measured for 7 different types of spheroids. Growth curves were measured in liquid overlay culture and thereafter the spheroids were attached to cover glasses and transferred to a chamber for micro-electrode measurements. The spheroids were randomly divided for pH or pO2 measurements which then were made under conditions as identical as possible. The decreases in pO2 and pH, delta pO2 and delta pH were calculated as the difference between the values in the culture medium and the values 200 micron inside the spheroids. Each type of spheroid had a certain relation between delta pO2 and delta pH. The human colon carcinoma HT29, the mouse mammary carcinoma EMT6 and the hamster lung V79-379A spheroids had high values of the quotient delta pO2/delta pH. The human thyroid carcinoma HTh7 spheroids and the 3 types of human glioma spheroids had lower quotients. There was a tendency for fast-growing spheroids to have high quotients. Two extreme types of spheroids, HT29 (high quotient) and U-118 MG (low quotient) were analyzed for lactate production and oxygen consumption. The U-118 MG spheroids produced about 3 times more lactate and consumed about 3 times less oxygen than the HT29 spheroids. The differences in lactate production could not be explained by differences in the pyruvate Km values of lactate dehydrogenase. The results indicate that there are significant metabolic differences between the spheroid systems studied.

Towards a subcutaneous optical biosensor based on thermally hydrocarbonised porous silicon.

Science.gov (United States)

Tong, Wing Yin; Sweetman, Martin J; Marzouk, Ezzat R; Fraser, Cara; Kuchel, Tim; Voelcker, Nicolas H

2016-01-01

Advanced biosensors in future medicine hinge on the evolvement of biomaterials. Porous silicon (pSi), a generally biodegradable and biocompatible material that can be fabricated to include environment-responsive optical characteristics, is an excellent candidate for in vivo biosensors. However, the feasibility of using this material as a subcutaneously implanted optical biosensor has never been demonstrated. Here, we investigated the stability and biocompatibility of a thermally-hydrocarbonised (THC) pSi optical rugate filter, and demonstrated its optical functionality in vitro and in vivo. We first compared pSi films with different surface chemistries and observed that the material was cytotoxic despite the outstanding stability of the THC pSi films. We then showed that the cytotoxicity correlates with reactive oxygen species levels, which could be mitigated by pre-incubation of THC pSi (PITHC pSi). PITHC pSi facilitates normal cellular phenotypes and is biocompatible in vivo. Importantly, the material also possesses optical properties capable of responding to microenvironmental changes that are readable non-invasively in cell culture and subcutaneous settings. Collectively, we demonstrate, for the first time, that PITHC pSi rugate filters are both biocompatible and optically functional for lab-on-a-chip and subcutaneous biosensing scenarios. We believe that this study will deepen our understanding of cell-pSi interactions and foster the development of implantable biosensors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Oxygen transport by oxygen potential gradient in dense ceramic oxide membranes

Energy Technology Data Exchange (ETDEWEB)

Maiya, P.S.; Balachandran, U.; Dusek, J.T.; Mieville, R.L. [Argonne National Lab., IL (United States). Energy Technology Div.; Kleefisch, M.S.; Udovich, C.A. [Amoco Exploration/Production, Naperville, IL (United States)

1996-05-01

Numerous studies have been conducted in recent years on the partial oxidation of methane to synthesis gas (syngas: CO + H{sub 2}) with air as the oxidant. In partial oxidation, a mixed-oxide ceramic membrane selectively transports oxygen from the air; this transport is driven by the oxygen potential gradient. Of the several ceramic materials the authors have tested, a mixed oxide based on the Sr-Fe-Co-O system has been found to be very attractive. Extensive oxygen permeability data have been obtained for this material in methane conversion experiments carried out in a reactor. The data have been analyzed by a transport equation based on the phenomenological theory of diffusion under oxygen potential gradients. Thermodynamic calculations were used to estimate the driving force for the transport of oxygen ions. The results show that the transport equation deduced from the literature describes the permeability data reasonably well and can be used to determine the diffusion coefficients and the associated activation energy of oxygen ions in the ceramic membrane material.

Histological case-control study of peeling-induced skin changes by different peeling agents in surgically subcutaneous undermined skin flaps in facelift patients.

Science.gov (United States)

Gonser, P; Kaestner, S; Jaminet, P; Kaye, K

2017-11-01

A histological evaluation of peeling-induced skin changes in subcutaneous undermined preauricular facial skin flaps of nine patients was performed. There were three treatment groups: Trichloroacetic acid (TCA) 25%, TCA 40% and phenol/croton oil; one group served as control. Two independent evaluators determined the epidermal and dermal thickness and the depth of necrosis (micrometre). The percentual tissue damage due to the peeling was calculated, and a one-sample t-test for statistical significance was performed. On the basis of the histomorphological changes, peeling depth was classified as superficial, superficial-partial, deep-partial and full thickness chemical burn. The histological results revealed a progression of wound depth for different peeling agents without full thickness necrosis. TCA peels of up to 40% can be safely applied on subcutaneous undermined facial skin flaps without impairing the vascular patency, producing a predictable chemical burn, whereas deep peels such as phenol/croton oil peels should not be applied on subcutaneous undermined skin so as to not produce skin slough or necrosis by impairing vascular patency. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Evaluation of Subcutaneous Phenobarbital Administration in Hospice Patients.

Science.gov (United States)

Hosgood, Jessica Richards; Kimbrel, Jason M; McCrate Protus, Bridget; Grauer, Phyllis A

2016-04-01

Phenobarbital is used in hospice and palliative care to treat refractory symptoms. In end-of-life care, Food and Drug Administration approved routes of administration may be unreasonable based on patients' status. In these cases, phenobarbital may be administered subcutaneously for symptom management. However, according to the American Hospital Formulary Service, subcutaneous administration of commercially available injectable phenobarbital is cautioned due to possible skin reactions. This study evaluates the tolerability of phenobarbital administered subcutaneously. Of 69 patients and 774 distinct subcutaneous phenobarbital injections, 2 site reactions were recorded (2.9% of patients; 0.3% of injections). Both were mild, grade 1 reactions. Each patient continued to receive subcutaneous phenobarbital via newly placed ports with no additional reactions. Based on these findings, phenobarbital appears to be well tolerated when administered subcutaneously. © The Author(s) 2014.

Influence of oxygen partial pressure on the characteristics of human hepatocarcinoma cells.

Science.gov (United States)

Trepiana, Jenifer; Meijide, Susana; Navarro, Rosaura; Hernández, M Luisa; Ruiz-Sanz, José Ignacio; Ruiz-Larrea, M Begoña

2017-08-01

Most of the in vitro studies using liver cell lines have been performed under atmospheric oxygen partial pressure (21% O 2 ). However, the oxygen concentrations in the liver and cancer cells are far from this value. In the present study, we have evaluated the influence of oxygen on 1) the tumor cell lines features (growth, steady-state ROS levels, GSH content, activities of antioxidant enzymes, p66 Shc and SOD expressions, metalloproteinases secretion, migration, invasion, and adhesion) of human hepatocellular carcinoma cell lines, and b) the response of the cells to an oxidant stimulus (aqueous leaf extract of the V. baccifera plant species). For this purpose, three hepatocarcinoma cell lines with different p53 status, HepG2 (wild-type), Huh7 (mutated), and Hep3B (deleted), were cultured (6-30 days) under atmospheric (21%) and more physiological (8%) pO 2 . Results showed that after long-term culturing at 8% versus 21% O 2 , the cellular proliferation rate and the steady-state levels of mitochondrial O 2 - were unaffected. However, the intracellular basal ROS levels were higher independently of the characteristics of the cell line. Moreover, the lower pO 2 was associated with lower glutathione content, the induction of p66 Shc and Mn-SOD proteins, and increased SOD activity only in HepG2. This cell line also showed a higher migration rate, secretion of active metalloproteinases, and a faster invasion. HepG2 cells were more resistant to the oxidative stress induced by V. baccifera. Results suggest that the long-term culturing of human hepatoma cells at a low, more physiological pO 2 induces antioxidant adaptations that could be mediated by p53, and may alter the cellular response to a subsequent oxidant challenge. Data support the necessity of validating outcomes from studies performed with hepatoma cell cultures under ambient O 2 . Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Ultra smooth NiO thin films on flexible plastic (PET) substrate at room temperature by RF magnetron sputtering and effect of oxygen partial pressure on their properties

International Nuclear Information System (INIS)

Nandy, S.; Goswami, S.; Chattopadhyay, K.K.

2010-01-01

Transparent p-type nickel oxide thin films were grown on polyethylene terephthalate (PET) and glass substrates by RF magnetron sputtering technique in argon + oxygen atmosphere with different oxygen partial pressures at room temperature. The morphology of the NiO thin films grown on PET and glass substrates was studied by atomic force microscope. The rms surface roughnesses of the films were in the range 0.63-0.65 nm. These ultra smooth nanocrystalline NiO thin films are useful for many applications. High resolution transmission electron microscopic studies revealed that the grains of NiO films on the highly flexible PET substrate were purely crystalline and spherical in shape with diameters 8-10 nm. XRD analysis also supported these results. NiO films grown on the PET substrates were found to have better crystalline quality with fewer defects than those on the glass substrates. The sheet resistances of the NiO films deposited on PET and glass substrates were not much different; having values 5.1 and 5.3 kΩ/□ and decreased to 3.05, 3.1 kΩ/□ respectively with increasing oxygen partial pressure. The thicknesses of the films on both substrates were ∼700 nm. It was also noted that further increase in oxygen partial pressure caused increase in resistivity due to formation of defects in NiO.

Synthesis of mixed-valent {alpha}- and {beta}-NaFe{sub 2}O{sub 3} polymorphs under controlled partial oxygen pressure

Energy Technology Data Exchange (ETDEWEB)

Bruno, Shaun R.; Blakely, Colin K. [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Poltavets, Viktor V., E-mail: poltavets@chemistry.msu.edu [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States)

2012-08-15

Synthesis of mixed valent compounds, especially when multiple polymorphs exist, requires careful control of the preparation conditions. {alpha}- and {beta}-NaFe{sub 2}O{sub 3} polymorphs were synthesized under controlled partial oxygen pressure (pO{sub 2}). pO{sub 2} regions of stability at 850 Degree-Sign C were determined for both phases for the first time. A modified oxygen buffer method was developed for the facile preparation of mixed valent oxides under controlled pO{sub 2}. {beta}-NaFe{sub 2}O{sub 3} is the only known n=2 member of the AM{sub n}O{sub n+1} (A=alkali metal, M=3d metal) rock-salt related homolog series with layered cation ordering. The possibility of new members of the homolog series with other 3d metals is considered. - Graphical abstract: Schematic section of phase composition vs. partial O{sub 2} pressure diagram at 850 Degree-Sign C for Na/Fe=1/2 and structure models of {alpha}- and {beta}-NaFe{sub 2}O{sub 3}. Highlights: Black-Right-Pointing-Pointer {alpha}- and {beta}-NaFe{sub 2}O{sub 3} polymorphs were synthesized under controlled oxygen pressure. Black-Right-Pointing-Pointer {beta}-NaFe{sub 2}O{sub 3} has rock-salt related structure with layered cation ordering. Black-Right-Pointing-Pointer Existence of the rock-salt related homolog series AM{sub n}O{sub n+1} is discussed.

Facilitated subcutaneous immunoglobulin administration (fSCIg)

DEFF Research Database (Denmark)

Blau, Igor-Wolfgang; Conlon, Niall; Petermann, Robert

2016-01-01

and diverse medical needs that treatments for SID management should strive to meet. In this special report, we study the opportunities provided by facilitated subcutaneous immunoglobulin administration (fSCIg) to treat patients for whom the conventional routes (intravenous and subcutaneous) are sub...

Ketogenic diet for high partial pressure oxygen diving.

Science.gov (United States)

Valadao, Jason M; Vigilante, John A; DiGeorge, Nicholas W; O'Connor, Sunila E; Bear, Alexandria; Kenyon, Jeffrey; Annis, Heather; Dituri, Joseph; Dituri, Amy E; Whelan, Harry T

2014-01-01

A ketogenic diet (KD) may decrease central nervous system oxygen toxicity symptoms in divers, and in view of this implication a feasibility/ toxicity pilot study was performed to demonstrate tolerance of KD while performing normal diving profiles. The exact mechanism of neuroprotection from the KD remains unknown; however, evidence to support the efficacy of the KD in reducing seizures is present in epilepsy and oxygen toxicity studies, and may provide valuable insight in diving activities. Three divers (two males and one female ages 32-45 with a history of deep diving and high pO2 exposure) on the KD made dives to varying depths in Hawaii using fully closed-circuit MK-15 and Inspiration rebreathers. These rebreathers have an electronically controlled set point, allowing the divers to monitor and control the oxygen level in the breathing loop, which can be varied manually by the divers. Oxygen level was varied during descent, bottom depth and ascent (decompression). Divers fasted for 12-18 hours before diet initiation. The ketosis level was verified by urinating on a Ketostix (reagent strips for urinalysis). Ketosis was achieved and was easily monitored with Ketostix in the simulated operational environment. The KD did not interfere with the diving mission; no seizure activity or signs or symptoms of CNS toxicity were observed, and there were no adverse effects noted by the divers while on the KD.

Effect of oxygen partial pressure on the density of antiphase boundaries in Fe3O4 thin films on Si(100)

Science.gov (United States)

Singh, Suraj Kumar; Husain, Sajid; Kumar, Ankit; Chaudhary, Sujeet

2018-02-01

Polycrystalline Fe3O4 thin films were grown on Si(100) substrate by reactive DC sputtering at different oxygen partial pressures PO2 for controlling the growth associated density of antiphase boundaries (APBs). The micro-Raman analyses were performed to study the structural and electronic properties in these films. The growth linked changes in the APBs density are probed by electron-phonon coupling strength (λ) and isothermal magnetization measurements. The estimated values of λ are found to vary from 0.39 to 0.56 with the increase in PO2 from 2.2 × 10-5 to 3.0 × 10-5 Torr, respectively. The saturation magnetization (saturation field) values are found to increase (decrease) from 394 (5.9) to 439 (3.0) emu/cm3 (kOe) with the increase in PO2 . The sharp Verwey transition (∼120 K), low saturation field, high saturation magnetization and low value of λ (comparable to the bulk value ∼0.51) clearly affirm the negligible amount of APBs in the high oxygen partial pressure deposited thin films.

[Cellular subcutaneous tissue. Anatomic observations].

Science.gov (United States)

Marquart-Elbaz, C; Varnaison, E; Sick, H; Grosshans, E; Cribier, B

2001-11-01

We showed in a companion paper that the definition of the French "subcutaneous cellular tissue" considerably varied from the 18th to the end of the 20th centuries and has not yet reached a consensus. To address the anatomic reality of this "subcutaneous cellular tissue", we investigated the anatomic structures underlying the fat tissue in normal human skin. Sixty specimens were excised from the surface to the deep structures (bone, muscle, cartilage) on different body sites of 3 cadavers from the Institut d'Anatomie Normale de Strasbourg. Samples were paraffin-embedded, stained and analysed with a binocular microscope taking x 1 photographs. Specimens were also excised and fixed after subcutaneous injection of Indian ink, after mechanic tissue splitting and after performing artificial skin folds. The aspects of the deep parts of the skin greatly varied according to their anatomic localisation. Below the adipose tissue, we often found a lamellar fibrous layer which extended from the interlobular septa and contained horizontally distributed fat cells. No specific tissue below the hypodermis was observed. Artificial skin folds concerned either exclusively the dermis, when they were superficial or included the hypodermis, but no specific structure was apparent in the center of the fold. India ink diffused to the adipose tissue, mainly along the septa, but did not localise in a specific subcutaneous compartment. This study shows that the histologic aspects of the deep part of the skin depend mainly on the anatomic localisation. Skin is composed of epidermis, dermis and hypodermis and thus the hypodermis can not be considered as being "subcutaneous". A difficult to individualise, fibrous lamellar structure in continuity with the interlobular septa is often found under the fat lobules. This structure is a cleavage line, as is always the case with loose connective tissues, but belongs to the hypodermis (i.e. fat tissue). No specific tissue nor any virtual space was

Stable subcutaneous cartilage regeneration of bone marrow stromal cells directed by chondrocyte sheet.

Science.gov (United States)

Li, Dan; Zhu, Lian; Liu, Yu; Yin, Zongqi; Liu, Yi; Liu, Fangjun; He, Aijuan; Feng, Shaoqing; Zhang, Yixin; Zhang, Zhiyong; Zhang, Wenjie; Liu, Wei; Cao, Yilin; Zhou, Guangdong

2017-05-01

In vivo niche plays an important role in regulating differentiation fate of stem cells. Due to lack of proper chondrogenic niche, stable cartilage regeneration of bone marrow stromal cells (BMSCs) in subcutaneous environments is always a great challenge. This study explored the feasibility that chondrocyte sheet created chondrogenic niche retained chondrogenic phenotype of BMSC engineered cartilage (BEC) in subcutaneous environments. Porcine BMSCs were seeded into biodegradable scaffolds followed by 4weeks of chondrogenic induction in vitro to form BEC, which were wrapped with chondrocyte sheets (Sheet group), acellular small intestinal submucosa (SIS, SIS group), or nothing (Blank group) respectively and then implanted subcutaneously into nude mice to trace the maintenance of chondrogenic phenotype. The results showed that all the constructs in Sheet group displayed typical cartilaginous features with abundant lacunae and cartilage specific matrices deposition. These samples became more mature with prolonged in vivo implantation, and few signs of ossification were observed at all time points except for one sample that had not been wrapped completely. Cell labeling results in Sheet group further revealed that the implanted BEC directly participated in cartilage formation. Samples in both SIS and Blank groups mainly showed ossified tissue at all time points with partial fibrogenesis in a few samples. These results suggested that chondrocyte sheet could create a chondrogenic niche for retaining chondrogenic phenotype of BEC in subcutaneous environment and thus provide a novel research model for stable ectopic cartilage regeneration based on stem cells. In vivo niche plays an important role in directing differentiation fate of stem cells. Due to lack of proper chondrogenic niche, stable cartilage regeneration of bone marrow stromal cells (BMSCs) in subcutaneous environments is always a great challenge. The current study demonstrated that chondrocyte sheet generated by

Microenvironmental oxygen partial pressure in acute myeloid leukemia: Is there really a role for hypoxia?

Science.gov (United States)

Rieger, Christina T; Fiegl, Michael

2016-07-01

Reduced oxygen partial pressure (pO2) has been recognized as being relevant in hematopoiesis and the pathophysiology of malignant diseases. Although hypoxic (meaning insufficient supply of oxygen) and anoxic areas are present and of pathophysiologic importance (by hypoxia-induced pathways such as HiF1α) in solid tumors, this may not be true for (malignant) hematologic cells. Hematopoiesis occurs in the stem cell niche, which is characterized, among other things, by extremely low pO2. However, in contrast to solid tumors, in this context, the low pO2 is physiological and this feature, among others, is shared by the malignant stem cell niche harboring leukemia-initiating cells. Upon differentiation, hematopoietic cells are constantly exposed to changes in pO2 as they travel throughout the human body and encounter arterial and venous blood and migrate into oxygen-carrier-free tissue with low pO2. Hematologic malignancies such as acute myeloid leukemia (AML) make little difference in this respect and, whereas low oxygen is the usual environment of AML cells, recent evidence suggests no role for real hypoxia. Although there is no evidence that AML pathophysiology is related to hypoxia, leukemic blasts still show several distinct biological features when exposed to reduced pO2: they down- or upregulate membrane receptors such as CXCR4 or FLT3, activate or inhibit intracellular signaling pathways such as PI3K, and specifically secrete cytokines (IL-8). In summary, reduced pO2 should not be mistaken for hypoxia (nor should it be so called), and it does not automatically induce hypoxia-response mechanisms; therefore, a strict distinction should be made between physiologically low pO2 (physoxia) and hypoxia. Copyright © 2016 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

Oxygen partial pressure control during in-situ high temperature X-ray diffraction on cerium dioxide

International Nuclear Information System (INIS)

Strach, M.; Belin, R.C.; Richaud, J-C.; Rogez, J.

2014-01-01

Cerium dioxide is widely used as a surrogate for plutonium dioxide in the studies of MOX type nuclear fuel. Thus, obtaining an accurate description of the structures present in this system in a range of temperatures is of importance to the development of fuel for the IV. generation of nuclear reactors. However, such a study requires appropriate scientific tools, in particular regarding the control and monitoring of the oxygen partial pressure (pO 2 ). Here we discuss several in-situ X-ray diffraction experiments performed to determine the phases present in the hypo-stoichiometric CeO 2-x region of the phase diagram and clearly demonstrate the need for controlling the pO 2 . (authors)

Changes in Cerebral Partial Oxygen Pressure and Cerebrovascular Reactivity During Intracranial Pressure Plateau Waves.

Science.gov (United States)

Lang, Erhard W; Kasprowicz, Magdalena; Smielewski, Peter; Pickard, John; Czosnyka, Marek

2015-08-01

Plateau waves in intracranial pressure (ICP) are frequently recorded in neuro intensive care and are not yet fully understood. To further investigate this phenomenon, we analyzed partial pressure of cerebral oxygen (pbtO2) and a moving correlation coefficient between ICP and mean arterial blood pressure (ABP), called PRx, along with the cerebral oxygen reactivity index (ORx), which is a moving correlation coefficient between cerebral perfusion pressure (CPP) and pbtO2 in an observational study. We analyzed 55 plateau waves in 20 patients after severe traumatic brain injury. We calculated ABP, ABP pulse amplitude (ampABP), ICP, CPP, pbtO2, heart rate (HR), ICP pulse amplitude (ampICP), PRx, and ORx, before, during, and after each plateau wave. The analysis of variance with Bonferroni post hoc test was used to compare the differences in the variables before, during, and after the plateau wave. We considered all plateau waves, even in the same patient, independent because they are separated by long intervals. We found increases for ICP and ampICP according to our operational definitions for plateau waves. PRx increased significantly (p = 0.00026), CPP (p pressure remains stable in ICP plateau waves, while cerebral autoregulatory indices show distinct changes, which indicate cerebrovascular reactivity impairment at the top of the wave. PbtO2 decreases during the waves and may show a slight overshoot after normalization. We assume that this might be due to different latencies of the cerebral blood flow and oxygen level control mechanisms. Other factors may include baseline conditions, such as pre-plateau wave cerebrovascular reactivity or pbtO2 levels, which differ between studies.

Subcutaneous phaeohyphomycosis caused by cladophialophora boppii

Directory of Open Access Journals (Sweden)

Pereira Rickson

2010-01-01

Full Text Available Subcutaneous phaeohyphomycosis is an infection of the skin and subcutaneous tissue, caused by dematiaceous fungi. An adult male presented with a history of multiple reddish nodules over the face and hands. Histopathological examination of the skin biopsies showed a dense granulomatous infiltrate of macrophages, containing intracytoplasmic basophilic bodies throughout the dermis. Gomori methenamine-silver stained sections revealed yeast cells within macrophages. Multiple cultures on Sabouraud′s dextrose agar grew Cladophialophora boppii. The patient was treated with oral itraconazole for a year and the response monitored with dermal ultrasound. This is the first case report of subcutaneous phaeohyphomycosis caused by Cl. boppii in India.

Advanced STEM/EDX investigation on an oxide scale thermally grown on a high-chromium iron–nickel alloy under very low oxygen partial pressure

International Nuclear Information System (INIS)

Latu-Romain, L.; Madi, Y.; Mathieu, S.; Robaut, F.; Petit, J.-P.; Wouters, Y.

2015-01-01

Highlights: • A scale grown on a high-chromium iron–nickel alloy under low oxygen partial pressure was studied. • STEM-EDX maps at high resolution on a transversal thin lamella have been conducted. • The real complexity of the oxide layer has been highlighted. • These results explain the elevated number of semiconducting contributions. - Abstract: A thermal oxide scale has been grown on a high-chromium iron-nickel alloy under very low oxygen partial pressure (1050 °C, 10"−"1"0 Pa). In this paper, a special attention has been paid to morphological and chemical characterizations of the scale by scanning transmission electron microscopy and energy dispersive X-ray analysis at high resolution on a cross-section thin lamella beforehand prepared by using a combined focused ion beam/scanning electron microscope instrument. The complexity of the oxide layer is highlighted, and the correlation between the present results and the ones of a photoelectrochemical study is discussed.

Brain tissue partial pressure of oxygen predicts the outcome of severe traumatic brain injury under mild hypothermia treatment.

Science.gov (United States)

Sun, Hongtao; Zheng, Maohua; Wang, Yanmin; Diao, Yunfeng; Zhao, Wanyong; Wei, Zhengjun

2016-01-01

The aim of this study was to investigate the clinical significance and changes of brain tissue partial pressure of oxygen (PbtO2) in the course of mild hypothermia treatment (MHT) for treating severe traumatic brain injury (sTBI). There were 68 cases with sTBI undergoing MHT. PbtO2, intracranial pressure (ICP), jugular venous oxygen saturation (SjvO2), and cerebral perfusion pressure (CPP) were continuously monitored, and clinical outcomes were evaluated using the Glasgow Outcome Scale score. Of 68 patients with sTBI, PbtO2, SjvO2, and CPP were obviously increased, but decreased ICP level was observed throughout the MHT. PbtO2 and ICP were negatively linearly correlated, while there was a positive linear correlation between PbtO2 and SjvO2. Monitoring CPP and SjvO2 was performed under normal circumstances, and a large proportion of patients were detected with low PbtO2. Decreased PbtO2 was also found after MHT. Continuous PbtO2 monitoring could be introduced to evaluate the condition of regional cerebral oxygen metabolism, thereby guiding the clinical treatment and predicting the outcome.

Measurement of forearm oxygen consumption

DEFF Research Database (Denmark)

Astrup, A; Simonsen, L; Bülow, J

1988-01-01

The classical forearm technique widely used for studies of skeletal muscle metabolism requires arterial cannulation. To avoid arterial puncture it is becoming more common to arterialize blood from a contralateral hand vein by local heating. This modification and the classical method have produced...... blood flow and decreases skeletal muscle blood flow. This facilitates mixing of superficial blood with deep venous blood. Contralateral heating increased deep venous oxygen saturation and abolished the pronounced glucose-induced increase in oxygen consumption observed in the control experiments after...... contradictory results regarding the contribution of skeletal muscle to glucose-induced thermogenesis. The effect on forearm circulation and the metabolism of heating the contralateral hand was examined before and after an oral glucose load. The results suggest that contralateral heating increases subcutaneous...

Primary Kaposi sarcoma of the subcutaneous tissue

Directory of Open Access Journals (Sweden)

Dezube Bruce J

2008-09-01

Full Text Available Abstract Background Involvement of the subcutis by Kaposi sarcoma (KS occurs primarily when cutaneous KS lesions evolve into deep penetrating nodular tumors. Primary KS of the subcutaneous tissue is an exceptional manifestation of this low-grade vascular neoplasm. Case presentation We present a unique case of acquired immune deficiency syndrome (AIDS-associated KS manifesting primarily in the subcutaneous tissue of the anterior thigh in a 43-year-old male, which occurred without overlying visible skin changes or concomitant KS disease elsewhere. Radiological imaging and tissue biopsy confirmed the diagnosis of KS. Conclusion This is the first documented case of primary subcutaneous KS occurring in the setting of AIDS. The differential diagnosis of an isolated subcutaneous lesion in an human immunodeficiency virus (HIV-infected individual is broad, and requires both imaging and a histopathological diagnosis to guide appropriate therapy.

Massive Preperitoneal Hematoma after a Subcutaneous Injection

Directory of Open Access Journals (Sweden)

Hideki Katagiri

2016-01-01

Full Text Available Preperitoneal hematomas are rare and can develop after surgery or trauma. A 74-year-old woman, receiving systemic anticoagulation, developed a massive preperitoneal hematoma after a subcutaneous injection of teriparatide using a 32-gauge, 4 mm needle. In this patient, there were two factors, the subcutaneous injection of teriparatide and systemic anticoagulation, associated with development of the hematoma. These two factors are especially significant, because they are widely used clinically. Although extremely rare, physicians must consider this potentially life-threatening complication after subcutaneous injections, especially in patients receiving anticoagulation.

Effect of systemic nitric oxide synthase inhibition on optic disc oxygen partial pressure in normoxia and in hypercapnia.

Science.gov (United States)

Petropoulos, Ioannis K; Pournaras, Jean-Antoine C; Stangos, Alexandros N; Pournaras, Constantin J

2009-01-01

To investigate the effect of systemic nitric oxide synthase (NOS) inhibition on optic disc oxygen partial pressure (PO(2)) in normoxia and hypercapnia. Intervascular optic disc PO(2) was measured in 12 anesthetized minipigs by using oxygen-sensitive microelectrodes placed 0.1), despite a 21% increase of mean arterial pressure. Optic disc PO(2) increase under hypercapnia was blunted after L-NAME injection (DeltaPO(2) = 0.6 +/- 1.1 mm Hg; 3%; P > 0.1), and this effect was reversible by L-arginine. Moreover, L-NAME reduced the response to carbogen by 29% (DeltaPO(2) = 9.1 +/- 4.4 mm Hg; 49%; P = 0.01 versus before L-NAME). The response to hyperoxia was not affected. Whereas systemic NOS inhibition did not affect optic disc PO(2) in normoxia, a blunting effect was noted on the CO(2)-induced optic disc PO(2) increase. Nitric oxide appears to mediate the hypercapnic optic disc PO(2) increase.

High temperature mechanisms and kinetics of SiC oxidation under low partial pressures of oxygen: application to the fuel cladding of gas fast reactors

International Nuclear Information System (INIS)

Hun, N.

2011-01-01

Gas Fast Reactor (GFR) is one of the different Generation IV concepts under investigation for energy production. SiC/SiC composites are candidates of primary interest for a GFR fuel cladding use, thanks to good corrosion resistance among other properties. The mechanisms and kinetics of SiC oxidation under operating conditions have to be identified and quantified as the corrosion can decrease the mechanical properties of the composite. An experimental device has been developed to study the oxidation of silicon carbide under high temperature and low oxygen partial pressure. The results pointed out that not only parabolic oxidation, but also interfacial reactions and volatilization occur under such conditions. After determining the kinetics of each mechanism, as functions of oxygen partial pressure and temperature, the data are used for the modeling of the composites oxidation. The model will be used to predict the lifetime of the composite in operating conditions. (author) [fr

Subcutaneous blood flow during insulin-induced hypoglycaemia

DEFF Research Database (Denmark)

Hilsted, J; Madsbad, S; Sestoft, L

1982-01-01

Subcutaneous blood flow was measured preceding insulin-induced hypoglycaemia, at the onset of hypoglycaemic symptoms and 2 h later in juvenile diabetics with and without autonomic neuropathy and in normal males. In all groups subcutaneous blood flow decreased at the onset of hypoglycaemic symptom...

Long-term operation of oxygen-limiting membrane bioreactor (MBR) for the development of simultaneous partial nitrification, anammox and denitrification (SNAD) process.

Science.gov (United States)

Zhao, Chuanqi; Wang, Gang; Xu, Xiaochen; Yang, Yuesuo; Yang, Fenglin

2017-07-18

In this study, an oxygen-limiting membrane bioreactor (MBR) with recirculation of biogas for relieving membrane fouling was successfully operated to realize the simultaneous partial nitrification, anammox and denitrification (SNAD) process. The MBR operation was considered effective in the long-term test with total nitrogen (TN) and chemical oxygen demand (COD) removal efficiencies of 94.86% and 98.91%, respectively. Membrane fouling was significantly alleviated due to the recirculation of biogas and the membrane had been cleaned four times with a normal filtration period of 52 days. The co-existence of ammonia-oxidizing bacteria (AOB), anammox and denitrifying bacteria in MBR was confirmed by scanning electron microscopy (SEM) and fluorescence in situ hybridizations (FISH) analysis. Furthermore, AOB were found close to the granule surface, while denitrifying bacteria and anammox were in the deeper layer of granules. Potential in excellent TN and COD removal, operational stability and sustainability, as well as in alleviating membrane fouling is expected by using this oxygen-limiting MBR.

Solar fuel processing efficiency for ceria redox cycling using alternative oxygen partial pressure reduction methods

International Nuclear Information System (INIS)

Lin, Meng; Haussener, Sophia

2015-01-01

Solar-driven non-stoichiometric thermochemical redox cycling of ceria for the conversion of solar energy into fuels shows promise in achieving high solar-to-fuel efficiency. This efficiency is significantly affected by the operating conditions, e.g. redox temperatures, reduction and oxidation pressures, solar irradiation concentration, or heat recovery effectiveness. We present a thermodynamic analysis of five redox cycle designs to investigate the effects of working conditions on the fuel production. We focused on the influence of approaches to reduce the partial pressure of oxygen in the reduction step, namely by mechanical approaches (sweep gassing or vacuum pumping), chemical approaches (chemical scavenger), and combinations thereof. The results indicated that the sweep gas schemes work more efficient at non-isothermal than isothermal conditions, and efficient gas phase heat recovery and sweep gas recycling was important to ensure efficient fuel processing. The vacuum pump scheme achieved best efficiencies at isothermal conditions, and at non-isothermal conditions heat recovery was less essential. The use of oxygen scavengers combined with sweep gas and vacuum pump schemes further increased the system efficiency. The present work can be used to predict the performance of solar-driven non-stoichiometric redox cycles and further offers quantifiable guidelines for system design and operation. - Highlights: • A thermodynamic analysis was conducted for ceria-based thermochemical cycles. • Five novel cycle designs and various operating conditions were proposed and investigated. • Pressure reduction method affects optimal operating conditions for maximized efficiency. • Chemical oxygen scavenger proves to be promising in further increasing efficiency. • Formulation of quantifiable design guidelines for economical competitive solar fuel processing

Subcutaneous self-injections of C1 inhibitor: an effective and safe treatment in a patient with hereditary angio-oedema.

Science.gov (United States)

Weller, K; Krüger, R; Maurer, M; Magerl, M

2016-01-01

A 25-year-old woman presented to our clinic with a history of recurrent swelling and abdominal symptoms for > 20 years. The patient's father was similarly affected. The patient was diagnosed with hereditary angio-oedema (HAE) due to C1 inhibitor deficiency. This was initially managed with systemic androgens, but the symptoms of hyperandrogenism eventually became intolerable. Treatment with icatibant (an antagonist of bradykinin B2 receptors) was partially successful. We changed the therapy to prophylactic treatment with C1 inhibitor. Although the patient became completely symptom-free under this regimen, she found the repeated intravenous injections unacceptable. Therefore, we changed the route of administration to subcutaneous injections of C1 inhibitor 1000 U in 10 mL twice weekly, using a subcutaneous infusion kit. Since that time (December 2013), she has remained completely free of symptoms under this regimen. To our knowledge, this is the first report documenting the efficacy and safety of subcutaneous injections of C1 inhibitor in a patient with HAE. © 2015 British Association of Dermatologists.

Partial deoxygenation of extender improves sperm quality, reduces lipid peroxidation and reactive oxygen species during cryopreservation of buffalo (Bubalus bubalis) semen.

Science.gov (United States)

Balamurugan, B; Ghosh, S K; Lone, S A; Prasad, J K; Das, G K; Katiyar, R; Mustapha, Abdul Rahman; Kumar, Ajay; Verma, M R

2018-02-01

The present study was designed to investigate the effect of partial deoxygenation of extender on sperm quality, lipid peroxidation (LPO) and reactive oxygen species (ROS) in buffalo (Bubalus bubalis) during cryopreservation of semen. Semen extender was prepared freshly and split into three sub-extenders [Extender I: control (non-deoxygenated), Extender II (partially deoxygenated by using LN 2 flushing) and Extender III (partially deoxygenated mechanically by vacuum pump)]. Amounts of dissolved oxygen (DO) were determined in all the three extenders and also in post-thaw semen. Ejaculates with mass motility of  ≥3+ and individual progressive motility of 70% or greater were collected from Murrah buffalo bulls and utilized in the study. Each semen sample was divided into Groups I (diluted with Extender I), II (diluted with Extender II) and III (diluted Extender III) with a maximum of 60 × 10 6 sperm/mL. French mini straws (0.25 mL) were filled with the extended semen samples, sealed with polyvinyl alcohol powder, kept for 3 h at 5 °C for equilibration and then stored in an automatic programmable freezer until the temperature of straws reached -145 °C followed by plunging the straws into liquid nitrogen (-196 °C). Semen samples were evaluated at pre-freeze and post-thaw stages for various variables [sperm motility, live sperm count, acrosomal integrity, hypo-osmotic swelling (HOS) response, LPO and ROS concentrations]. The mean DO was less (P fertility of frozen-thawed buffalo sperm. Copyright © 2017 Elsevier B.V. All rights reserved.

Penile Subcutaneous Fibrolipoma Postaugmentative Phalloplasty

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Patrizio Vicini

2013-01-01

Full Text Available Fibrolipomas are a rare subtype of lipomas. We describe a case of a man suffering from subcutaneous penile fibrolipoma, who three months earlier has been submitted to an augmentative phalloplasty due to aesthetic dysmorphophobia. After six months from the excision of the mass, the penile elongation and penile enlargement were stable, and the patient was satisfied with his sexual intercourse and sexual life. To our knowledge, this is the first reported penile subcutaneous fibrolipoma case in the literature. The diagnostics and surgical features of this case are discussed.

Subcutaneous blood flow in psoriasis

International Nuclear Information System (INIS)

Klemp, P.

1985-01-01

The simultaneously recorded disappearance rates of 133 xe from subcutaneous adipose tissue in the crus were studied in 10 patients with psoriasis vulgaris using atraumatic labeling of the tissue in lesional skin (LS) areas and symmetrical, nonlesional skin (NLS) areas. Control experiments were performed bilaterally in 10 younger, healthy subjects. The subcutaneous washout rate constant was significantly higher in LS, 0.79 +/- 0.05 min-1 x 10(2) compared to the washout rate constant of NLS, 0.56 +/- 0.07 min-1. 10(2), or the washout rate constant in the normal subjects, 0.46 +/- 0.17 min-1 x 10(2). The mean washout rate constant in NLS was 25% higher than the mean washout rate constant in the normal subjects. The difference was, however, not statistically significant. Differences in the washout rate constants might be due to abnormal subcutaneous tissue-to-blood partition (lambda) in the LS--and therefore not reflecting the real differences in the subcutaneous blood flow (SBF). The lambda for 133 Xe was therefore measured--using a double isotope washout method ( 133 Xe and [ 131 I]antipyrine)--in symmetrical sites of the lateral crus in LS and NLS of 10 patients with psoriasis vulgaris and in 10 legs of normal subjects. In LS the lambda was 4.52 +/- 1.67 ml/g, which was not statistically different from that of NLS, 5.25 +/- 2.19 ml/g, nor from that of normal subcutaneous tissue, 4.98 +/- 1.04 ml/g. Calculations of the SBF using the obtained lambda values gave a significantly higher SBF in LS, 3.57 +/- 0.23 ml/100 g/min, compared to SBF in the NLS, 2.94 +/- 0.37 ml/100 g/min. There was no statistically significant difference between SBF in NLS and SBF in the normal subjects. The increased SBF in LS of psoriatics might be a secondary phenomenon to an increased heat loss in the lesional skin

Effects of Partially Ionised Medical Oxygen, Especially with O2•−, in Vibration White Finger Patients

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Slavomír Perečinský

2014-05-01

Full Text Available A major symptom of hand-arm vibration syndrome is a secondary Raynaud’s phenomenon—vibration white finger (VWF—which results from a vasospasm of the digital arteries caused by work with vibration devices leading to occupational disease. Pharmacotherapy of VWF is often ineffective or has adverse effects. The aim of this work was to verify the influence of inhalation of partially ionized oxygen (O2•− on peripheral blood vessels in the hands of patients with VWF. Ninety one (91patients with VWF underwent four-finger adsorption plethysmography, and the pulse wave amplitude was recorded expressed in numeric parameters—called the native record. Next, a cold water test was conducted following with second plethysmography. The patients were divided in to the three groups. First and second inhaled 20-min of ionized oxygen O2•− or oxygen O2 respectively. Thirth group was control without treatment. All three groups a follow-up third plethysmography—the post-therapy record. Changes in the pulse wave amplitudes were evaluated. Inpatients group inhaling O2•− a modest increase of pulse wave amplitude was observed compared to the native record; patients inhaling medical oxygen O2 and the control showed a undesirable decline of pulse wave amplitude in VWF fingers. Strong vasodilatation were more frequent in the group inhaling O2•− compare to O2 (p < 0.05. Peripheral vasodilatation achieved by inhalation of O2•− could be used for VWF treatment without undesirable side effect in hospital as well as at home environment.

Vaporization study on vanadium-oxygen solid solution by mass spectrometric method

International Nuclear Information System (INIS)

Banchorndhevakul, W.; Matsui, Tsuneo; Naito, Keiji

1986-01-01

The vapor pressures over vanadium-oxygen solid solution (0.001 ≤ O/V ≤ 0.145) were measured by mass-spectrometric method in the temperature range of 1,855 ∼ 2,117 K. The main vapor species were observed to be V(g) and VO(g). The vapor pressure of V(g) is higher than that of VO(g) over the solid solutions with all O/V ratios except for O/V = 0.145. The vapor pressure of V(g) is nearly independent of O/V ratio. The vapor pressure of VO(g) decreases with decreasing O/V ratio. The oxygen partial pressure was calculated as a function of temperature and O/V ratio from the vapor pressures of V(g) and VO(g), from which the partial molar enthalpy and entropy of oxygen in the solid solution were determined. The partial molar enthalpy of oxygen was observed to be independent of composition, suggesting the presence of very weak interaction between interstitial oxygens. The compositional dependence of the partial molar entropy of oxygen can be explained by assuming the occupation of the octahedral site in bcc vanadium lattice by the interstitial oxygens. The excess partial molar entropy of oxygen was compared with the value derived from the sum of the contributions from the volume expansion, electronic heat capacity and vibrational terms. (author)

Monitoring in microvascular tissue transfer by measurement of oxygen partial pressure: four years experience with 125 microsurgical transplants.

Science.gov (United States)

Jonas, René; Schaal, Thomas; Krimmel, Michael; Gülicher, Dirk; Reinert, Siegmar; Hoffmann, Jürgen

2013-06-01

In a prospective study, the characteristics and benefit of an invasive measurement of oxygen partial pressure (pO(2)) with the aid of a polarographic sensor were investigated in 125 microsurgical reconstructions of the head and neck area over a period of 45 months. Measurements were performed over 96 h in eight different types of microsurgically revascularized flaps for extra- and intraoral reconstructions and were evaluated separately for each flap type. Of 125 reconstructions the system indicated malperfusion in 18 cases. Salvage surgery was performed in 17 cases due to venous thrombosis (6 cases), arterial thrombosis (3 cases), a combination of arterial and venous thrombosis (2 cases), rheological problems (3 cases), venous insufficiency by hematoma (2 cases) and kinking of vessels (1 case). In 10 cases salvage surgery was successful, 7 flaps were lost despite salvage surgery. In all these cases, the polarographic probe indicated the necessity of salvage surgery correctly. After 96 h no malperfusion was seen. Postoperatively, a common and characteristic development of the oxygen partial pressure in different types of flaps was seen. Initially, a clear increase of pO(2) could be measured. During 96 h, a slow decrease of pO(2) was observed. In conclusion polarographic measurement of pO(2) can be an excellent apparative supplement for the postoperative clinical control of microsurgically revascularized transplants. In buried flaps, this technique represents the only reliable method for transplant monitoring. Copyright © 2012 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

[The effect of altered oxygen partial pressure on the resisitance to hypoxia and expression of oxygen-sensitive genes in Drosophila melanogaster].

Science.gov (United States)

Berezovs'kyĭ, V Ia; Chaka, O H; Litovka, I H; Levashov, M I; Ianko, R V

2014-01-01

As a result of resistance test to hypoxia of Drosophilas melanogaster of Oregon strain, we identified a high resistance (Group II) and low resistance (Group III) subpopulations of flies. Flies from groups II and III were incubated in a constant normobaric hypoxia (Po2=62-64 mm Hg) for 10 generations. A highly resistant group (Group IV) were exposed to a shortterm anoxia (Po,=1,5 mm Hg, 5 min) every generation. Larvae from Groups II, III, and IV demonstrated significantly elevated levels of Sir and CG 14740 expression. Larvae from Group II had a significantly higher expression of CG 14740 compared to group III. The restitution time after exposure to anoxia was significantly reduced in Group II (on 31% of the control values) Our results suggest that long-term adaptation to low oxygen partial pressure of highly resistant Drosophila significantly reduces the time of restitution and increases the expression of Sir2 and CG14740 genes.

The structural phase diagram and oxygen equilibrium partial pressure of YBa 2Cu 3O 6+ x studied by neutron powder diffraction and gas volumetry

Science.gov (United States)

Andersen, N. H.; Lebech, B.; Poulsen, H. F.

1990-12-01

An experimental technique based on neutron powder diffraction and gas volumetry is presented and used to study the structural phase diagram of YBa 2Cu 3O 6+ x under equilibrium conditions in an extended part of ( x, T)-phase (0.15< x<0.92 and 25° C< T<725°C). Our experimental observations lend strong support to a recent two-dimensional anisotropic next-nearest-neighbour Ising model calculation (the ASYNNNI model) of the basal plane oxygen ordering based of first principle interaction parameters. Simultaneous measurements of the oxygen equilibrium partial pressure show anomalies, one of which proves the thermodynamic stability of the orthorhombic OII double cell structure. Striking similarity with predictions of recent model calculations support that another anomaly may be interpreted to result from local one-dimensional fluctuations in the distribution of oxygen atoms in the basal plane of tetragonal YBCO. Our pressure data also indicate that x=0.92 is a maximum obtainable oxygen concentration for oxygen pressures below 760 Torr.

Recurrent subcutaneous emphysema of the face: a challenging clinical problem.

Science.gov (United States)

Hojjati, Hossein; Davani, Sam Zeraatian Nejad; Johari, Hamed Ghoddusi

2007-01-01

In the neck or face, there are different causes for subcutaneous emphysema such as injury to the sinuses, the hypopharynx, the laryngotracheal complex, the pulmonary parenchyma, the esophagus or the presence of gas-forming organisms. However, factitious subcutaneous emphysema, a rare cause, must be considered in the differential diagnosis. In this clinical report, we discuss a 20-year-old girl who was under follow-up because of recurrent subcutaneous emphysema of the face and periorbital area. After 2 years of work-ups, including a period of close observation in the intensive care unit, self air injection by syringe was found as the cause of recurrent subcutaneous emphysema of the face, and the patient was labeled as having factitious recurrent subcutaneous emphysema. Therefore, when a patient presents with unexplained recurrent subcutaneous emphysema, one should suspect self-infliction and examine for puncture marks.

High temperature microcalorimetry. Study of metal-oxygen systems

International Nuclear Information System (INIS)

Tetot, R.; Picard, C.; Boureau, G.; Gerdanian, P.

1981-01-01

Determination of partial molar enthalpy in metal-oxygen systems at 1050 0 C. Three representative systems are studied: the solution of oxygen in titanium, the titanium-oxygen system and the uranium-oxygen system from UOsub(2.00) to UOsub(2.60) [fr

Seed storage at elevated partial pressure of oxygen, a fast method for analysing seed ageing under dry conditions

Science.gov (United States)

Groot, S. P. C.; Surki, A. A.; de Vos, R. C. H.; Kodde, J.

2012-01-01

Background and Aims Despite differences in physiology between dry and relative moist seeds, seed ageing tests most often use a temperature and seed moisture level that are higher than during dry storage used in commercial practice and gene banks. This study aimed to test whether seed ageing under dry conditions can be accelerated by storing under high-pressure oxygen. Methods Dry barley (Hordeum vulgare), cabbage (Brassica oleracea), lettuce (Lactuca sativa) and soybean (Glycine max) seeds were stored between 2 and 7 weeks in steel tanks under 18 MPa partial pressure of oxygen. Storage under high-pressure nitrogen gas or under ambient air pressure served as controls. The method was compared with storage at 45 °C after equilibration at 85 % relative humidity and long-term storage at the laboratory bench. Germination behaviour, seedling morphology and tocopherol levels were assessed. Key Results The ageing of the dry seeds was indeed accelerated by storing under high-pressure oxygen. The morphological ageing symptoms of the stored seeds resembled those observed after ageing under long-term dry storage conditions. Barley appeared more tolerant of this storage treatment compared with lettuce and soybean. Less-mature harvested cabbage seeds were more sensitive, as was the case for primed compared with non-primed lettuce seeds. Under high-pressure oxygen storage the tocopherol levels of dry seeds decreased, in a linear way with the decline in seed germination, but remained unchanged in seeds deteriorated during storage at 45 °C after equilibration at 85 % RH. Conclusions Seed storage under high-pressure oxygen offers a novel and relatively fast method to study the physiology and biochemistry of seed ageing at different seed moisture levels and temperatures, including those that are representative of the dry storage conditions as used in gene banks and commercial practice. PMID:22967856

Seed storage at elevated partial pressure of oxygen, a fast method for analysing seed ageing under dry conditions.

Science.gov (United States)

Groot, S P C; Surki, A A; de Vos, R C H; Kodde, J

2012-11-01

Despite differences in physiology between dry and relative moist seeds, seed ageing tests most often use a temperature and seed moisture level that are higher than during dry storage used in commercial practice and gene banks. This study aimed to test whether seed ageing under dry conditions can be accelerated by storing under high-pressure oxygen. methods: Dry barley (Hordeum vulgare), cabbage (Brassica oleracea), lettuce (Lactuca sativa) and soybean (Glycine max) seeds were stored between 2 and 7 weeks in steel tanks under 18 MPa partial pressure of oxygen. Storage under high-pressure nitrogen gas or under ambient air pressure served as controls. The method was compared with storage at 45 °C after equilibration at 85 % relative humidity and long-term storage at the laboratory bench. Germination behaviour, seedling morphology and tocopherol levels were assessed. The ageing of the dry seeds was indeed accelerated by storing under high-pressure oxygen. The morphological ageing symptoms of the stored seeds resembled those observed after ageing under long-term dry storage conditions. Barley appeared more tolerant of this storage treatment compared with lettuce and soybean. Less-mature harvested cabbage seeds were more sensitive, as was the case for primed compared with non-primed lettuce seeds. Under high-pressure oxygen storage the tocopherol levels of dry seeds decreased, in a linear way with the decline in seed germination, but remained unchanged in seeds deteriorated during storage at 45 °C after equilibration at 85 % RH. Seed storage under high-pressure oxygen offers a novel and relatively fast method to study the physiology and biochemistry of seed ageing at different seed moisture levels and temperatures, including those that are representative of the dry storage conditions as used in gene banks and commercial practice.

Determination of oxygen nonstoichiometry and diffusivity in mixed conducting oxides by oxygen Coulometric titration. II. Oxygen nonstoichiometry and defect model for La0.8Sr0.2CoO3-d

NARCIS (Netherlands)

Lankhorst, M.H.R.; Lankhorst, M.H.R.; Bouwmeester, Henricus J.M.

1997-01-01

The oxygen nonstoichiometry of La0.8Sr0.2CoO3-delta has been determined as a function of oxygen partial pressure and temperature using a high-temperature coulometric titration cell. For each measured value of the oxygen chemical potential, the oxygen nonstoichiometry is found to be nearly

Subcutaneous granuloma annulare

Directory of Open Access Journals (Sweden)

Dhar Sandipan

1994-01-01

Full Text Available Two cases of subcutaneos granuloma annulare are reported. Clinical presentation was in the form of hard subcutaneous nodules; histopathology confirmed the clinical diagnosis. The cases were unique because of onset in adult hood, occurrence over unusual sites and absence of classical lesions of granuloma annulare elsewhere.

Enfisema subcutâneo maciço - Tratamento com drenos subcutâneos Massive subcutaneous emphysema - Management using subcutaneous drains

Directory of Open Access Journals (Sweden)

Maria Sucena

2010-04-01

Full Text Available O enfisema subcutâneo é uma complicação relativamente comum na sequência de técnicas invasivas, procedimentos cirúrgicos e algumas patologias médicas. Na maior parte dos casos apenas causa sintomatologia minor e o tratamento é habitualmente conservador. Mesmo quando grave, raramente tem consequências patofisiológicas significativas, apesar de ser extremamente desconfortável para o doente. Os autores descrevem um caso clínico de enfisema subcutâneo maciço, de rápida instalação, após saída acidental de tubo de drenagem torácica, em doente com pneumotórax espontâneo secundário e fístula broncopleural. O enfisema foi tratado através da colocação, sob anestesia local, de dois drenos subcutâneos na parede anterossuperior do tórax, conectados a sacos de drenagem. Após a colocação dos drenos subcutâneos verificou-se uma franca melhoria clínica do doente, com descompressão eficaz do enfisema subcutâneo. No presente caso clínico, a técnica de drenagem do enfisema maciço mostrou-se simples, segura e eficaz, permitindo o alívio sintomático imediato.Massive subcutaneous emphysema is a relatively common complication in invasive techniques, surgical practice and some medical conditions. Subcutaneous emphysema is usually treated conservatively and may only cause minimal symptoms. Even when it is severe, subcutaneous emphysema rarely has pathophysiologic consequences, but it is extremely uncomfortable for the patient. The authors report a case of massive and rapid developing subcutaneous emphysema following chest tube displacement in a patient with spontaneous secondary pneumothorax and large air leak. The emphysema was treated with two subcutaneous drains, inserted using local anesthesia, on both sides of the chest (antero-superior thoracic wall, connected to drainage bags. The drains produced a dramatic clinical improvement and provided effective decompression of the subcutaneous emphysema. In this clinical case, the

Effect of oxygen partial pressure on the microstructural, optical and gas sensing characterization of nanostructured Gd doped ceria thin films deposited by pulsed laser deposition

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Nagaraju P.

2017-12-01

Full Text Available Microstructural properties of 10 mol% gadolinium doped ceria (CeO2 thin films that were deposited on quartz substrate at substrate temperature of 1023 K by using pulsed laser deposition with different oxygen partial pressures in the range of 50–200 mTorr. The influence of oxygen partial pressure on microstructural, morphological, optical and gas sensing characterization of the thin films was systematically studied. The microstructure of the thin films was investigated using X-ray diffraction, atomic force microscopy and Raman spectroscopy. Morphological studies have been carried out using scanning electron microscope. The experimental results confirmed that the films were polycrystalline in nature with cubic fluorite structure. Optical properties of the thin films were examined using UV–vis spectrophotometer. The optical band gap calculated from Tauc’s relation. Gas sensing characterization has been carried at different operating temperatures (room temperature to 523 K for acetone gas. Response and recovery times of the sensor were calculated using transient response plot.

Role of Liposuction Combined with Subcutaneous Mastectomy in ...

African Journals Online (AJOL)

deformity in two other patients. Conclusions: Liposuction combined with subcutaneous mastectomy is a reliable, versatile, less time consuming and valid procedure for the treatment of gynecomastia. This procedure provides satisfactory aesthetic results. KEY WORDS: Gynecomastia, liposuction, subcutaneous mastectomy.

Oxygen Exposure Resulting in Arterial Oxygen Tensions Above the Protocol Goal Was Associated With Worse Clinical Outcomes in Acute Respiratory Distress Syndrome.

Science.gov (United States)

Aggarwal, Neil R; Brower, Roy G; Hager, David N; Thompson, B Taylor; Netzer, Giora; Shanholtz, Carl; Lagakos, Adrian; Checkley, William

2018-04-01

High fractions of inspired oxygen may augment lung damage to exacerbate lung injury in patients with acute respiratory distress syndrome. Participants enrolled in Acute Respiratory Distress Syndrome Network trials had a goal partial pressure of oxygen in arterial blood range of 55-80 mm Hg, yet the effect of oxygen exposure above this arterial oxygen tension range on clinical outcomes is unknown. We sought to determine if oxygen exposure that resulted in a partial pressure of oxygen in arterial blood above goal (> 80 mm Hg) was associated with worse outcomes in patients with acute respiratory distress syndrome. Longitudinal analysis of data collected in these trials. Ten clinical trials conducted at Acute Respiratory Distress Syndrome Network hospitals between 1996 and 2013. Critically ill patients with acute respiratory distress syndrome. None. We defined above goal oxygen exposure as the difference between the fraction of inspired oxygen and 0.5 whenever the fraction of inspired oxygen was above 0.5 and when the partial pressure of oxygen in arterial blood was above 80 mm Hg. We then summed above goal oxygen exposures in the first five days to calculate a cumulative above goal oxygen exposure. We determined the effect of a cumulative 5-day above goal oxygen exposure on mortality prior to discharge home at 90 days. Among 2,994 participants (mean age, 51.3 yr; 54% male) with a study-entry partial pressure of oxygen in arterial blood/fraction of inspired oxygen that met acute respiratory distress syndrome criteria, average cumulative above goal oxygen exposure was 0.24 fraction of inspired oxygen-days (interquartile range, 0-0.38). Participants with above goal oxygen exposure were more likely to die (adjusted interquartile range odds ratio, 1.20; 95% CI, 1.11-1.31) and have lower ventilator-free days (adjusted interquartile range mean difference of -0.83; 95% CI, -1.18 to -0.48) and lower hospital-free days (adjusted interquartile range mean difference of -1.38; 95

Subcutaneous tissue flaps for hallux covering.

Science.gov (United States)

Vaienti, Luca; Urzola, Victor; Scotti, Andrea; Masetto, L

2010-03-01

With the understanding of the extensive vascular supply of the subcutaneous tissue, of its efficacy in the protection of the anatomical structures and of its capability of promoting the adequate functioning of very stressed regions of the human body, the use of subcutaneous adipose flaps has become a valid and sometimes the only reasonable therapeutic weapon in the treatment of small and medium-sized tissue loss. Such a defect represents a common complication of great toe injuries and surgery. Here subcutaneous flap reconstruction is proposed for the treatment of dorsal and medial soft tissue losses of the hallux complicated with infection. Two case are reported. To the best of the authors' knowledge, this application has not been reported in this anatomical site so far. The technique might be worth knowing both for orthopedic and plastic surgeons, as it may represent a safe, less invasive solution for most tegumentary problems of the dorso-medial side of the first ray.

Laser heating and oxygen partial pressure effects on the dynamic magnetic properties of perpendicular CoFeAlO films

Energy Technology Data Exchange (ETDEWEB)

Wu, Di [Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Li, Wei [State Key Laboratory of Precision Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062 (China); Tang, Minghong [Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Zhang, Zongzhi, E-mail: zzzhang@fudan.edu.cn [Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Lou, Shitao [State Key Laboratory of Precision Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062 (China); Jin, Q.Y. [Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); State Key Laboratory of Precision Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062 (China)

2016-07-01

The impact of oxidation and laser heating on the dynamic magnetic properties of perpendicularly magnetized Co{sub 50}Fe{sub 25}Al{sub 25}O films has been studied by time-resolved magneto-optical Kerr effect in a fs-laser pump-probe setup. We find that pump laser fluence F{sub p} can affect the effective magnetic anisotropy field and thus the precession frequency f seriously, leading to an increased dependence of effective magnetic damping factor α{sub eff} on the external field at higher fluences. Moreover, the α{sub eff} increases with increasing the oxygen partial pressure P{sub O2} while the uniaxial anisotropy energy K{sub u} and Landau factor g decrease, owing to the increased proportion of superparamagnetic CoFe oxides formed by over-oxidation. By optimizing both the F{sub p} and P{sub O2}, the intrinsic damping factor is determined to be lower than 0.028 for the perpendicular film showing a uniaxial anisotropy energy as high as 4.3×10{sup 6} erg/cm{sup 3}. The results in this study provide a promising approach to manipulate the magnetic parameters for possible applications in spintronic devices. - Highlights: • A new kind of perpendicular thin film material, oxidized CoFeAl, has been fabricated. • The precession frequency and effective damping are strongly affected by higher fluence. • The effective damping factor increases with oxygen partial pressure. • The intrinsic damping factor is below 0.028 for the CFAO film with K{sub u}=4.3×10{sup 6} erg/cm{sup 3}.

Cost-minimization of mabthera intravenous versus subcutaneous administration

NARCIS (Netherlands)

Bax, P.; Postma, M.J.

2013-01-01

Objectives: To identify and compare all costs related to preparing and administrating MabThera for the intravenous and subcutaneous formulations in Dutch hematological patients. The a priori notion is that the costs of subcutaneous MabThera injections are lower compared to intravenous infusion due

Effects of normobaric versus hyperbaric oxygen on cell injury induced by oxygen and glucose deprivation in acute brain slices

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Laurent Chazalviel

2016-01-01

Full Text Available Normobaric oxygen (NBO and hyperbaric oxygen (HBO are emerging as a possible co-treatment of acute ischemic stroke. Both have been shown to reduce infarct volume, to improve neurologic outcome, to promote endogenous tissue plasminogen activator-induced thrombolysis and cerebral blood flow, and to improve tissue oxygenation through oxygen diffusion in the ischemic areas, thereby questioning the interest of HBO compared to NBO. In the present study, in order to investigate and compare the oxygen diffusion effects of NBO and HBO on acute ischemic stroke independently of their effects at the vascular level, we used acute brain slices exposed to oxygen and glucose deprivation, an ex vivo model of brain ischemia that allows investigating the acute effects of NBO (partial pressure of oxygen (pO 2 = 1 atmospheres absolute (ATA = 0.1 MPa and HBO (pO 2 = 2.5 ATA = 0.25 MPa through tissue oxygenation on ischemia-induced cell injury as measured by the release of lactate dehydrogenase. We found that HBO, but not NBO, reduced oxygen and glucose deprivation-induced cell injury, indicating that passive tissue oxygenation (i.e. without vascular support of the brain parenchyma requires oxygen partial pressure higher than 1 ATA.

Iatrogenic Lower Extremity Subcutaneous Emphysema after Prolonged Robotic-Assisted Hysterectomy

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Monica Hagan Vetter

2015-01-01

Full Text Available Subcutaneous emphysema is a known complication of carbon dioxide insufflation, an essential component of laparoscopy. The literature contains reports of hypercarbia, pneumothorax, or pneumomediastinum. However, isolated lower extremity subcutaneous emphysema remains a seldom-reported complication. We report a case of unilateral lower extremity subcutaneous emphysema following robotic-assisted hysterectomy, bilateral salpingooophorectomy, staging, and anterior/posterior colporrhaphy for carcinosarcoma and vaginal prolapse. On postoperative day 1, the patient developed tender crepitus and bruising of her right ankle. Radiography confirmed presence of subcutaneous air. Vital signs and laboratory findings were unremarkable. Her symptoms spontaneously improved over time, and she was discharged in good condition on day 2. In stable patients with postoperative extremity swelling or pain with crepitus on exam, the diagnosis of iatrogenic subcutaneous emphysema must be considered.

Subcutaneous emphysema in cavitary pulmonary tuberculosis without pneumothorax or pneumomediastinum

Directory of Open Access Journals (Sweden)

Ramakant Dixit

2012-01-01

Full Text Available Extra-alveolar air in the form of subcutaneous tissue emphysema is observed in a variety of clinical settings. Spontaneous subcutaneous emphysema in the absence of pneumothorax or pneumomediastinum is very rare. We report a case of spontaneous subcutaneous emphysema secondary to cavitary pulmonary tuberculosis in the absence of pneumothorax or pneumomediastinum.

Time required for partial pressure of arterial oxygen equilibration during mechanical ventilation after a step change in fractional inspired oxygen concentration.

Science.gov (United States)

Cakar, N; Tuŏrul, M; Demirarslan, A; Nahum, A; Adams, A; Akýncý, O; Esen, F; Telci, L

2001-04-01

To determine the time required for the partial pressure of arterial oxygen (PaO2) to reach equilibrium after a 0.20 increment or decrement in fractional inspired oxygen concentration (FIO2) during mechanical ventilation. A multi-disciplinary ICU in a university hospital. Twenty-five adult, non-COPD patients with stable blood gas values (PaO2/FIO2 > or = 180 on the day of the study) on pressure-controlled ventilation (PCV). Following a baseline PaO2 (PaO2b) measurement at FIO2 = 0.35, the FIO2 was increased to 0.55 for 30 min and then decreased to 0.35 without any other change in ventilatory parameters. Sequential blood gas measurements were performed at 3, 5, 7, 9, 11, 15, 20, 25 and 30 min in both periods. The PaO2 values measured at the 30th min after a step change in FIO2 (FIO2 = 0.55, PaO2[55] and FIO2 = 0.35, PaO2[35]) were accepted as representative of the equilibrium values for PaO2. Each patient's rise and fall in PaO2 over time, PaO2(t), were fitted to the following respective exponential equations: PaO2b + (PaO2[55]-PaO2b)(1-e-kt) and PaO2[55] + (PaO2[35]-PaO2[55])(e-kt) where "t" refers to time, PaO2[55] and PaO2[35] are the final PaO2 values obtained at a new FIO2 of 0.55 and 0.35, after a 0.20 increment and decrement in FIO2, respectively. Time constant "k" was determined by a non-linear fitting curve and 90% oxygenation times were defined as the time required to reach 90% of the final equilibrated PaO2 calculated by using the non-linear fitting curves. Time constant values for the rise and fall periods were 1.01 +/- 0.71 min-1, 0.69 +/- 0.42 min-1, respectively, and 90% oxygenation times for rises and falls in PaO2 periods were 4.2 +/- 4.1 min-1 and 5.5 +/- 4.8 min-1, respectively. There was no significant difference between the rise and fall periods for the two parameters (p > 0.05). We conclude that in stable patients ventilated with PCV, after a step change in FIO2 of 0.20, 5-10 min will be adequate for obtaining a blood gas sample to measure a Pa

Mixed oxygen ion/electron-conducting ceramics for oxygen separation

Energy Technology Data Exchange (ETDEWEB)

Stevenson, J.W.; Armstrong, T.R.; Armstrong, B.L. [Pacific Northwest National Lab., Richland, WA (United States)

1996-08-01

Mixed oxygen ion and electron-conducting ceramics are unique materials that can passively separate high purity oxygen from air. Oxygen ions move through a fully dense ceramic in response to an oxygen concentration gradient, charge-compensated by an electron flux in the opposite direction. Compositions in the system La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y{minus}z}Fe{sub y}N{sub z}O{sub 3{minus}{delta}}, perovskites where M=Sr, Ca, and Ba, and N=Mn, Ni, Cu, Ti, and Al, have been prepared and their electrical, oxygen permeation, oxygen vacancy equilibria, and catalytic properties evaluated. Tubular forms, disks, and asymmetric membrane structures, a thin dense layer on a porous support of the same composition, have been fabricated for testing purposes. In an oxygen partial gradient, the passive oxygen flux through fully dense structures was highly dependent on composition. An increase in oxygen permeation with increased temperature is attributed to both enhanced oxygen vacancy mobility and higher vacancy populations. Highly acceptor-doped compositions resulted in oxygen ion mobilities more than an order of magnitude higher than yttria-stabilized zirconia. The mixed conducting ceramics have been utilized in a membrane reactor configuration to upgrade methane to ethane and ethylene. Conditions were established to balance selectivity and throughput in a catalytic membrane reactor constructed from mixed conducting ceramics.

Subcutaneous fibrosis after whole neck irradiation

International Nuclear Information System (INIS)

Hirota, Saeko; Tsujino, Kayoko; Oshitani, Takashi; Hishikawa, Yoshio; Takada, Yoshiki; Kono, Michio; Abe, Mitsuyuki

2002-01-01

Purpose: To identify the risk factors for moderate to severe subcutaneous fibrosis after whole neck irradiation. Methods and Materials: We analyzed 233 cases of patients who had undergone whole neck irradiation with 4-MV X-ray or 8-10-MeV electrons, or both, and had been followed with regard to their skin condition for at least 1 year. The prescribed dose to the whole neck ranged from 19.2 to 72.4 Gy (median 50). The skin-absorbed dose was specified as that at a depth of 4.1 mm (d4.1-mm depth ), and a biologically equivalent dose (BED) of d4.1-mm depth was also estimated (BED 1.8 4.1-mm depth ). Results: Univariate analysis revealed that previous neck dissection, concurrent chemotherapy, corticosteroid administration as a part of chemotherapy, fractionation, and BED 1.8 4.1-mm depth were significant prognostic variables. Multivariate analysis showed that BED 1.8 4.1-mm depth and previous neck dissection were the only prognostic variables for moderate to severe subcutaneous fibrosis. Conclusion: A high dose to a 4.1-mm depth of the skin and a history of neck dissection were identified as the predominant risk factors for moderate to severe subcutaneous fibrosis after whole neck irradiation. A subcutaneous dose should be considered in radiotherapy treatment planning involving the whole neck, especially in cases in which patients have undergone previous neck dissection

Oxygen partial pressure treatment of the electron-doped superconductor (Nd0.92Ce0.08)2CuO4-δ

International Nuclear Information System (INIS)

Suzuki, M.; Ami, T.; Isobe, M.; Tanaka, M.

1992-01-01

The condition under which the superconducting phase in (Nd 1-x Ce x ) 2 CuO 4-δ with x=0.08 is obtained was determined in the 1/T-log Po 2 phase diagram using an oxygen partial pressure (Po 2 ) controllable heat treatment system in conjunction with a quench system. The superconducting area is very narrow and is adjacent to the area of significant decomposition. We determined that the a-axis lattice constant increased slightly as the character of the electric conduction changed from semiconductive to metallic. (orig.)

Oxygen partial pressure treatment of the electron-doped superconductor (Nd0.92Ce0.08)2CuO4-δ

International Nuclear Information System (INIS)

Suzuki, M.; Ami, T.; Isobe, M.; Tanaka, M.

1992-01-01

The condition under which the superconducting phase in (Nd 1-x Ce x ) 2 CuO 4-δ with x = 0.08 is obtained was determined in the 1/T-log Po 2 phase diagram using an oxygen partial pressure (Po 2 ) controllable heat treatment system in conjunction with a quench system. The superconducting area is very narrow and is adjacent to the area of significant decomposition. In this paper, the authors determined that the a-axis lattice constant increased slightly as the character of the electric conduction changed from semiconductive to metallic

Oxygen permeation modelling of perovskites

NARCIS (Netherlands)

van Hassel, Bart A.; van Hassel, B.A.; Kawada, Tatsuya; Sakai, Natsuko; Yokokawa, Harumi; Dokiya, Masayuki; Bouwmeester, Henricus J.M.

1993-01-01

A point defect model was used to describe the oxygen nonstoichiometry of the perovskites La0.75Sr0.25CrO3, La0.9Sr0.1FeO3, La0.9Sr0.1CoO3 and La0.8Sr0.2MnO3 as a function of the oxygen partial pressure. Form the oxygen vacancy concentration predicte by the point defect model, the ionic conductivity

Subcutaneous encapsulated fat necrosis

DEFF Research Database (Denmark)

Aydin, Dogu; Berg, Jais O

2016-01-01

We have described subcutaneous encapsulated fat necrosis, which is benign, usually asymptomatic and underreported. Images have only been published on two earlier occasions, in which the necrotic nodules appear "pearly" than the cloudy yellow surface in present case. The presented image may help...

Influence of polymeric microspheres on the myocardial oxygen partial pressure in the beating heart of pigs.

Science.gov (United States)

Hiebl, B; Mrowietz, C; Lee, S; Braune, S; Knaut, M; Lendlein, A; Franke, R P; Jung, F

2011-07-01

Injection of labeled microspheres is an established method in animal models to analyze the capillary organ blood flow at different time points. However, the microspheres can lead to stenoses of the capillary lumen, which might affect tissue oxygen supply. Our study aimed to investigate the influence of repeated injections of microspheres into the left coronary artery on the tissue oxygen partial pressure (pO(2)) in the downstream supplied myocardium of Göttingen minipigs. Tests (n=6 pigs each) were performed with two differently sized microspheres (ø=10 ± 0.1 μm (M10) or ø=15 ± 0.15 μm (M15)) from polystyrene. The pO(2) was measured in the midmyocardium of the left and right ventricle for 6 min continuously after each of five injections (1 × 10(6) microspheres each). There was a time laps of 12 min between each injection. In addition, the influence of the carrier solution was analyzed solely in the identical time frame. pO(2) decreased significantly in the myocardial area supplied by the ramus interventricularis paraconalis after injection of M15 microspheres. In contrast, the application of the M10 microspheres did not change the myocardial pO(2). This finding suggests to use microspheres with diameters not exceeding 10 μm for the coronary blood flow assessment. Copyright © 2011 Elsevier Inc. All rights reserved.

The Effect of Oxygen Partial Pressure during Active Layer Deposition on Bias Stability of a-InGaZnO TFTs

International Nuclear Information System (INIS)

Huang Xiao-Ming; Zhu Hong-Bo; Wang Yong-Jin; Wu Chen-Fei; Lu Hai; Ren Fang-Fang

2015-01-01

The effect of oxygen partial pressure (P_O_2) during the channel layer deposition on bias stability of amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistors (TFTs) is investigated. As P_O_2 increases from 10% to 30%, it is found that the device shows enhanced bias stress stability with significantly reduced threshold voltage drift under positive gate bias stress. Based on the x-ray photoelectron spectroscopy measurement, the concentration of oxygen vacancies (O_V) within the a-IGZO layer is suppressed by increasing P_O_2. Meanwhile, the low-frequency noise analysis indicates that the average trap density near the channel/dielectric interface continuously drops with increasing P_O_2. Therefore, the improved interface quality with increasing P_O_2 during the channel layer deposition can be attributed to the reduction of interface O_V-related defects, which agrees with the enhanced bias stress stability of the a-IGZO TFTs. (paper)

Management of extensive surgical emphysema with subcutaneous drain: A case report

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Quoc Tran

Full Text Available Introduction: Subcutaneous emphysema (SE is a frequent and often self-limiting complication of tube thoracostomy or other cardiothoracic procedures. On rare occasions, severe and extensive surgical emphysema marked by palpable cutaneous tension, dysphagia, dysphonia, palpebral closure or associated with pneumoperitoneum, airway compromise, “tension phenomenon” and respiratory failure require treatment. Presentation of case: A 67 year old lady presented with a large spontaneous pneumothorax on the background of end-stage chronic obstructive pulmonary disease (COPD and newly diagnosed lung cancer, developed extensive surgical emphysema following insertion of a chest drain. Immediate improvement was observed after insertion of a large-bore, 26 French (Fr. intercostal catheter, subcutaneous drain which was maintained under low suction (−5 cm H2O for a further 24 h. Discussion: Several methods have been described in the literature for the treatment of extensive subcutaneous emphysema, including: emergency tracheostomy, multisite subcutaneous drainage, infraclavicular “blow holes” incisions and subcutaneous drains or simply increasing suction on an in situ chest drain. Here a large-bore, fenestrated, subcutaneous drain maintained on low negative pressure also provided the necessary decompression. Conclusion: In the absence of a comparative study to identify the most effective method to manage extensive subcutaneous emphysema, this case highlights an effective, simple and safe management option. Keywords: Pneumothorax, Subcutaneous emphysema, Drain, Low suction, Intercostal catheter, Case report

Increasing arterial oxygen partial pressure during cardiopulmonary resuscitation is associated with improved rates of hospital admission.

Science.gov (United States)

Spindelboeck, Walter; Schindler, Otmar; Moser, Adrian; Hausler, Florian; Wallner, Simon; Strasser, Christa; Haas, Josef; Gemes, Geza; Prause, Gerhard

2013-06-01

As recent clinical data suggest a harmful effect of arterial hyperoxia on patients after resuscitation from cardiac arrest (CA), we aimed to investigate this association during cardiopulmonary resuscitation (CPR), the earliest and one of the most crucial phases of recirculation. We analysed 1015 patients who from 2003 to 2010 underwent out-of-hospital CPR administered by emergency medical services serving 300,000 inhabitants. Inclusion criteria for further analysis were nontraumatic background of CA and patients >18 years of age. One hundred and forty-five arterial blood gas analyses including oxygen partial pressure (paO2) measurement were obtained during CPR. We observed a highly significant increase in hospital admission rates associated with increases in paO2 in steps of 100 mmHg (13.3 kPa). Subsequently, data were clustered according to previously described cutoffs (≤ 60 mmHg [8 kPa

Intermittent subcutaneous methadone administration in the management of cancer pain.

Science.gov (United States)

Centeno, Carlos; Vara, Francisco

2005-01-01

Methadone is a strong opioid analgesic that has been used successfully in cancer pain management. The oral route of administration is generally preferred for opioid analgesics. However that route sometimes cannot be used. Experience with continuous subcutaneous methadone infusions has produced local intolerance. The aim of this study was to analyze the use of intermittent subcutaneous methadone injections. Ten patients whose pain was well-controlled with oral methadone (average dose 30 mg, range 10 to 120 mg) participated in the study. A subcutaneous small vein needle (butterfly) was used exclusively for administration of methadone. Over a period of seven days the local discomfort of each injection was evaluated by means of a Verbal Numerical Rating Scale (NRS) and the site of infusion was observed. When any degree of erythema or inflammation was seen, the infusion site was changed. The initial subcutaneous dose was the same as the previously administered oral dose. A daily record was kept of the dose used, level of pain, and toxicity symptoms. This close vigilance was aimed at avoiding dosage errors due to variations among individuals in acceptance to previous oral medication. Changes in dosage were allowed according to standard medical criteria. Two patients were withdrawn from the study due to non-painful irritation at the infusion point. Another eight patients tolerated repeated administration of subcutaneous methadone over seven days. Any local irritation from subcutaneous methadone that occurred was managed satisfactorily by changing the infusion site and limiting doses to 30 mg. In seven of 182 repeat administration, injection site changes were necessitated by local irritation. The NRS for local discomfort was 2/10. The two patients who were intolerant of the subcutaneous injections were receiving injected doses which were significantly higher than the others (42 mg as compared to 25 mg). Dose adjustments needed when changing from the oral to the

Measurements of partial oxygen pressure pO2 using the OxyLite system in R3327-AT tumors under isoflurane anesthesia.

Science.gov (United States)

Wen, Bixiu; Urano, Muneyasu; O'Donoghue, Joseph A; Ling, C Clifton

2006-09-01

The presence of oxygen-deficient tumor cells is a critical issue in cancer therapy. To identify tumor hypoxia, tissue partial oxygen pressure (pO2) can be measured directly. The OxyLite system allows determination of pO2 in tumors and permits continuous measurements of pO2 at a fixed point. In this study, this system was used to continuously measure pO2 in R3327-AT tumors in animals anesthetized with isoflurane. In addition, continuous pO2 measurement was performed in the muscle in non-tumor-bearing animals. In animals breathing isoflurane balanced by air, tumor pO2 at fixed positions decreased rapidly within 1-2 min of probe positioning but remained stable thereafter. In animals breathing isoflurane balanced by pure oxygen, tumor pO2 was higher and remained high. We also measured pO2 values at multiple positions in R3327-AT tumors of various sizes, with anesthetized animals breathing either air or pure oxygen. Our data showed that the frequency of pO2 measurements below 2.5 or 5.0 mmHg was significantly higher in animals breathing air than in animals breathing pure oxygen. Measurements in different-sized tumors showed that the mean pO2 value decreased as tumor volume increased, with the largest change occurring between tumor volumes of 100 and 200 mm3. Our data demonstrate that the OxyLite system, when used with isoflurane anesthesia, is a valuable tool in the study of tumor hypoxia.

Diffusion coefficients of oxygen and hemoglobin as obtained simultaneously from photometric determination of the oxygenation of layers of hemoglobin solutions

NARCIS (Netherlands)

Spaan, J. A.; Kreuzer, F.; van Wely, F. K.

1980-01-01

The oxygenation of layers of deoxygenated hemoglobin solutions after a sudden exposure to a gas containing oxygen at a partial pressure P1 has been studied by a photometric method. Layer thicknesses varied between 50 and 250 micron, hemoglobin concentrations between 0.1 and 0.34kg/l, and oxygen

[The influence of oxygen partial pressure change and vascularization of rabbit wound through negative pressure wound therapy].

Science.gov (United States)

Yang, Fan; Hu, Duan; Bai, Xiang-jun; Zhang, Kun; Li, Ren-jie; Xue, Chen-chen

2012-07-01

To investigate the effect of vacuum sealing drainage (VSD) on variation of oxygen partial pressure (PtO2) and vascularization. The 12 cases of rabbit's wound models were undergoing the VSD (vacuum group, n = 6) or conventional therapy (conventional group, n = 6). Variation of PtO2 was measured by oxygen partial pressure admeasuring apparatus, expression of hypoxia inducible factor 1α (HIF-1α) mRNA was measured by real-time fluorescent quantitative PCR, content of vascular endothelial growth factor (VEGF) was measured by ELISA after tissue homogenate in 7 days. Vascular endothelial cell (VEC) and new blood capillary (NBC) of hematoxylin-eosin slice of tissue were counted by using light microscope. Average value of PtO2 of vacuum group was significant lower than conventional group (t = -99.780 to -5.305, P < 0.01). Expression of HIF-1α (30 minutes, 1, 6, 12 hours were 3.11 ± 0.07, 3.68 ± 0.26, 4.16 ± 0.13 and 3.91 ± 0.26 respectively) and content of VEGF (30 minutes, 1, 6, 12 hours were 103.3 ± 2.4, 134.2 ± 9.0, 167.8 ± 3.8 and 232.1 ± 9.5 respectively) of vacuum group were increased after 30 minutes and significant lower than conventional group (t = 13.038 - 80.208, P < 0.01), and both of them were reduced after 24 hours (P < 0.05). Counting numbers of VEC (2.47 ± 0.45 to 4.70 ± 0.38) and NBC (1.33 ± 0.49 to 4.33 ± 0.68) of vacuum group were increased at the same time-point and significant higher than conventional group (t = -0.670 to 16.500, P < 0.05). PtO2 of wound surface could be reduced significantly by VSD. Expression of HIF-1α and content of VEGF were increased by VSD for enhancing differentiated state of VEC and construction of NBC, which were better for vascularization and wound healing.

Recurrent, giant subcutaneous leiomyosarcoma of the thigh

Directory of Open Access Journals (Sweden)

Gao Chuanping, MD

2015-10-01

Full Text Available We present a case of recurrent, massive subcutaneous leiomyosarcoma involving the left thigh in a 29-year-old male from Madagascar. The patient had earlier undergone local resection of subcutaneous leiomyosarcoma a half year before. After surgical intervention, local recurrence developed at this site and was rapidly growing. The patient was surgically treated with a 2-cm-wide margin local excision in our hospital. The patient has remained recurrence free at 1-year follow-up.

Unsupervised Assessment of Subcutaneous and Visceral Fat by MRI

DEFF Research Database (Denmark)

Jørgensen, Peter Stanley; Larsen, Rasmus; Wraae, Kristian

2009-01-01

This paper presents a. method for unsupervised assessment of visceral and subcutaneous adipose tissue in the abdominal region by MRI. The identification of the subcutaneous and the visceral regions were achieved by dynamic programming constrained by points acquired from an active shape model...

Effects of dissolved oxygen and pH on nitrous oxide production rates in autotrophic partial nitrification granules.

Science.gov (United States)

Rathnayake, Rathnayake M L D; Oshiki, Mamoru; Ishii, Satoshi; Segawa, Takahiro; Satoh, Hisashi; Okabe, Satoshi

2015-12-01

The effects of dissolved oxygen (DO) and pH on nitrous oxide (N2O) production rates and pathways in autotrophic partial nitrification (PN) granules were investigated at the granular level. N2O was primarily produced by betaproteobacterial ammonia-oxidizing bacteria, mainly Nitrosomonas europaea, in the oxic surface layer (production increased with increasing bulk DO concentration owing to activation of the ammonia (i.e., hydroxylamine) oxidation in this layer. The highest N2O emissions were observed at pH 7.5, although the ammonia oxidation rate was unchanged between pH 6.5 and 8.5. Overall, the results of this study suggest that in situ analyses of PN granules are essential to gaining insight into N2O emission mechanisms in a granule. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impaired expression of mitochondrial and adipogenic genes in adipose tissue from a patient with acquired partial lipodystrophy (Barraquer-Simons syndrome: a case report

Directory of Open Access Journals (Sweden)

Guallar Jordi P

2008-08-01

Full Text Available Abstract Introduction Acquired partial lipodystrophy or Barraquer-Simons syndrome is a rare form of progressive lipodystrophy. The etiopathogenesis of adipose tissue atrophy in these patients is unknown. Case presentation This is a case report of a 44-year-old woman with acquired partial lipodystrophy. To obtain insight into the molecular basis of lipoatrophy in acquired partial lipodystrophy, we examined gene expression in adipose tissue from this patient newly diagnosed with acquired partial lipodystrophy. A biopsy of subcutaneous adipose tissue was obtained from the patient, and DNA and RNA were extracted in order to evaluate mitochondrial DNA abundance and mRNA expression levels. Conclusion The expression of marker genes of adipogenesis and adipocyte metabolism, including the master regulator PPARγ, was down-regulated in subcutaneous adipose tissue from this patient. Adiponectin mRNA expression was also reduced but leptin mRNA levels were unaltered. Markers of local inflammatory status were unaltered. Expression of genes related to mitochondrial function was reduced despite unaltered levels of mitochondrial DNA. It is concluded that adipogenic and mitochondrial gene expression is impaired in adipose tissue in this patient with acquired partial lipodystrophy.

Ultrasonographic Findings of Subcutaneous and Muscular Sparganosis

International Nuclear Information System (INIS)

Park, Hee Jin; Park, Noh Hyuck; Lee, Eun Ja; Park, Chan Sub; Lee, Sung Moon; Park, Sung Il

2009-01-01

This study was deigned to evaluate the ultrasonographic findings of subcutaneous and intramuscular sparganosis. Nine cases of histologically proven subcutaneous and intramuscular sparganosis lesions in seven patients (mean patient age, 59 years; M:F = 6:1) were reviewed retrospectively. Two patients had recurrent sparganosis. A color Doppler examination was performed in all cases. A prior history of ingestion of raw snake meat was noted for two patients. Patients presented with a palpable mass and induration (n = 7) and dull pain (n = 4). Lesion locations were in the thigh (n = 4), lower leg (n = 2), chest wall (n = 1), an inguinal location (n = 1) and the neck (n = 1). Five lesions were in the subcutaneous fat layer and four lesions had intramuscular locations. Calcification was noted in two cases. All cases showed heterogeneous hypoechoic serpiginous tubular-and-oval lesions. The lesions were conglomerated or discrete in appearance. All nine cases showed the presence of lesions with a multi-layered wall with variable intraluminal echogenicity, at least in one segment of the lesion. Increased vascularity was noted on color Doppler examinations in two patients with pain. Subcutaneous or intramuscular sparganosis should be included in the differential diagnosis when a serpiginous tubular-and-oval lesion is noted that is seen with a multi-layered wall with variable intraluminal echogenicity

Microsensor and transcriptomic signatures of oxygen depletion in biofilms associated with chronic wounds: Biofilms and oxygen

Energy Technology Data Exchange (ETDEWEB)

James, Garth A. [Center for Biofilm Engineering, Montana State University, Bozeman Montana; Ge Zhao, Alice [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Usui, Marcia [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Underwood, Robert A. [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Nguyen, Hung [The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman Washington; Beyenal, Haluk [The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman Washington; deLancey Pulcini, Elinor [Center for Biofilm Engineering, Montana State University, Bozeman Montana; Agostinho Hunt, Alessandra [Department of Microbiology and Molecular Genetics, 5180 Biomedical and Physical Sciences, Michigan State University, East Lansing Michigan; Bernstein, Hans C. [Pacific Northwest National Laboratory, Chemical and Biological Signature Science, Richland Washington; Fleckman, Philip [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Olerud, John [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Williamson, Kerry S. [Center for Biofilm Engineering, Montana State University, Bozeman Montana; Franklin, Michael J. [Center for Biofilm Engineering, Montana State University, Bozeman Montana; Stewart, Philip S. [Center for Biofilm Engineering, Montana State University, Bozeman Montana

2016-02-16

Polymicrobial biofilms have been implicated in delayed wound healing, although the mechanisms by which biofilms impair wound healing are poorly understood. Many species of bacteria produce exotoxins and exoenzymes that may inhibit healing. In addition, oxygen consumption by biofilms may impede wound healing. In this study, we used oxygen microsensors to measure oxygen transects through in vitro-cultured biofilms, biofilms formed in vivo in a diabetic (db/db) mouse model, and ex vivo human chronic wound specimens. The results show that oxygen levels within both euthanized and live mouse wounds had steep gradients that reached minima ranging from 19 to 61% oxygen partial pressure, compared to atmospheric oxygen levels. The oxygen gradients in the mouse wounds were similar to those observed for clinical isolates cultured in vitro and for human ex vivo scabs. No oxygen gradients were observed for heat-killed scabs, suggesting that active metabolism by the viable bacteria contributed to the reduced oxygen partial pressure of the wounds. To characterize the metabolic activities of the bacteria in the mouse wounds, we performed transcriptomics analyses of Pseudomonas aeruginosa biofilms associated with the db/db mice wounds using Affymetrix microarrays. The results demonstrated that the bacteria expressed genes for metabolic activities associated with cell growth. Interestingly, the transcriptome results indicated that the bacteria within the wounds also experienced oxygen-limitation stress. Among the bacterial genes that were expressed in vivo were genes associated with the Anr-mediated hypoxia-stress response. Other bacterial stress response genes highly expressed in vivo were genes associated with stationary-phase growth, osmotic stress, and RpoH-mediated heat shock stress. Overall, the results support the hypothesis that the metabolic activities of bacteria in biofilms act as oxygen sinks in chronic wounds and that the depletion of oxygen contributes to the

Impact of partial pressure of oxygen in blood samples on the performance of systems for self-monitoring of blood glucose.

Science.gov (United States)

Schmid, Christina; Baumstark, Annette; Pleus, Stefan; Haug, Cornelia; Tesar, Martina; Freckmann, Guido

2014-03-01

The partial pressure of oxygen (pO2) in blood samples can affect glucose measurements with oxygen-sensitive systems. In this study, we assessed the influence of different pO2 levels on blood glucose (BG) measurements with five glucose oxidase (GOD) systems and one glucose dehydrogenase (GDH) system. All selected GOD systems were indicated by the manufacturers to be sensitive to increased oxygen content of the blood sample. Venous blood samples of 16 subjects (eight women, eight men; mean age, 52 years; three with type 1 diabetes, four with type 2 diabetes, and nine without diabetes) were collected. Aliquots of each sample were adjusted to the following pO2 values: ≤45 mm Hg, approximately 70 mm Hg, and ≥150 mm Hg. For each system, five consecutive measurements on each sample were performed using the same test strip lot. Relative differences between the mean BG value at a pO2 level of approximately 70 mm Hg, which was considered to be similar to pO2 values in capillary blood samples, and the mean BG value at pO2 levels ≤45 mm Hg and ≥150 mm Hg were calculated. The GOD systems showed mean relative differences between 11.8% and 44.5% at pO2 values ≤45 mm Hg and between -14.6% and -21.2% at pO2 values ≥150 mm Hg. For the GDH system, the mean relative differences were -0.3% and -0.2% at pO2 values ≤45 mm Hg and ≥150 mm Hg, respectively. The magnitude of the pO2 impact on BG measurements seems to vary among the tested oxygen-sensitive GOD systems. The pO2 range in which oxygen-sensitive systems operate well should be provided in the product information.

Transmission of arterial oxygen partial pressure oscillations to the cerebral microcirculation in a porcine model of acute lung injury caused by cyclic recruitment and derecruitment.

Science.gov (United States)

Klein, K U; Boehme, S; Hartmann, E K; Szczyrba, M; Heylen, L; Liu, T; David, M; Werner, C; Markstaller, K; Engelhard, K

2013-02-01

Cyclic recruitment and derecruitment (R/D) play a key role in the pathomechanism of acute lung injury (ALI) leading to respiration-dependent oscillations of arterial partial pressure of oxygen (Pa(O(2))). These Pa(O(2)) oscillations could also be forwarded to the cerebral microcirculation. In 12 pigs, partial pressure of oxygen was measured in the thoracic aorta (Pa(O(2))) and subcortical cerebral tissue (Pbr(O(2))). Cerebral cortical haemoglobin oxygen saturation (Sbr(O(2))), cerebral blood flow (CBF), and peripheral haemoglobin saturation (Sp(O(2))) were assessed by spectroscopy and laser Doppler flowmetry. Measurements at different fractions of inspired oxygen (F(I(O(2)))) were performed at baseline and during cyclic R/D. frequency domain analysis, the Mann-Whitney test, linear models to test the influence of Pa(O(2)) and systolic arterial pressure (SAP) oscillations on cerebral measurements. Parameters [mean (SD)] remained stable during baseline. Pa(O(2)) oscillations [10.6 (8) kPa, phase(reference)], systemic arterial pressure (SAP) oscillations [20 (9) mm Hg, phase(Pa(O(2))-SAP) -33 (72)°], and Sp(O(2))oscillations [1.9 (1.7)%, phase(Pa(O(2))-Sp(O(2))) 264 (72)°] were detected during lung R/D at 1.0. Pa(O(2)) oscillations decreased [2.7 (3.5) kPa, P=0.0008] and Sp(O(2)) oscillations increased [6.8 (3.9)%, P=0.0014] at F(I(O(2))) 0.3. In the brain, synchronized Pbr(O(2)) oscillations [0.6 (0.4) kPa, phase(Pa(O(2))-Pbr(O(2))) 90 (39)°], Sbr(O(2)) oscillations [4.1 (1.5)%, phase(Pa(O(2))-Sbr(O(2))) 182 (54)°], and CBF oscillations [198 (176) AU, phase(Pa(O(2))-CBF) 201 (63)°] occurred that were dependent on Pa(O(2)) and SAP oscillations. Pa(O(2)) oscillations caused by cyclic R/D are transmitted to the cerebral microcirculation in a porcine model of ALI. These cyclic oxygen alterations could play a role in the crosstalk of acute lung and brain injury.

Scan Quality and Entrance Skin Dose in Thoracic CT: A Comparison between Bismuth Breast Shield and Posteriorly Centered Partial CT Scans

International Nuclear Information System (INIS)

Tappouni, Rafel; Mathers, Bradley

2012-01-01

Objectives. To compare the effectiveness of the bismuth breast shield and partial CT scan in reducing entrance skin dose and to evaluate the effect of the breast shield on image quality (IQ). Methods. Nanodots were placed on an adult anthropomorphic phantom. Standard chest CT, CT with shield, and partial CT were performed. Nanodot readings and effective doses were recorded. 50 patients with chest CTs obtained both with and without breast shields were reviewed. IQ was evaluated by two radiologists and by measuring Hounsfield units (HUs) and standard deviation (SD) of HU in anterior subcutaneous region. Results. Breast shield and the partial CT scans reduced radiation to the anterior chest by 38% and 16%, respectively. Partial CT increased dose to the posterior chest by 37% and effective dose by 8%. Change in IQ in shield CT was observed in the anterior chest wall. Significant change in IQ was observed in 5/50 cases. The shield caused an increase of 20 HU (P = 0.021) and a 1.86 reduction in SD of HU (P = 0.027) in the anterior compared to posterior subcutaneous regions. Summary. Bismuth breast shield is more effective than the partial CT in reducing entrance skin dose while maintaining image quality

Dependence of nitrite oxidation on nitrite and oxygen in low-oxygen seawater

Science.gov (United States)

Sun, Xin; Ji, Qixing; Jayakumar, Amal; Ward, Bess B.

2017-08-01

Nitrite oxidation is an essential step in transformations of fixed nitrogen. The physiology of nitrite oxidizing bacteria (NOB) implies that the rates of nitrite oxidation should be controlled by concentration of their substrate, nitrite, and the terminal electron acceptor, oxygen. The sensitivities of nitrite oxidation to oxygen and nitrite concentrations were investigated using 15N tracer incubations in the Eastern Tropical North Pacific. Nitrite stimulated nitrite oxidation under low in situ nitrite conditions, following Michaelis-Menten kinetics, indicating that nitrite was the limiting substrate. The nitrite half-saturation constant (Ks = 0.254 ± 0.161 μM) was 1-3 orders of magnitude lower than in cultivated NOB, indicating higher affinity of marine NOB for nitrite. The highest rates of nitrite oxidation were measured in the oxygen depleted zone (ODZ), and were partially inhibited by additions of oxygen. This oxygen sensitivity suggests that ODZ specialist NOB, adapted to low-oxygen conditions, are responsible for apparently anaerobic nitrite oxidation.

The relation between in vivo ethylene production and oxygen partial pressure

NARCIS (Netherlands)

Sanders, M.G.; Wild, de H.P.J.

2003-01-01

Modelling in vivo ethylene production rate in relation to O2 partial pressure was used to improve understanding of enzyme kinetics of 1-aminocyclopropane-1-carboxylate oxidase (ACC oxidase). Tomato fruit were stored in an extensive range of O2 partial pressures at 8, 13 and 18 °C. Ethylene

The comparison of the intestinal adaptation effects of subcutaneous ...

African Journals Online (AJOL)

Aim: Insulin has been reported to have positive effects on intestinal adaptation after short bowel syndrome when applicated oral or subcutaneously. The purpose of this study is to compare the intestinal adaptation effects of subcutaneous and oral routes of insulin in rats with short bowel syndrome. Materials and Methods: ...

Internal stress and opto-electronic properties of ZnO thin films deposited by reactive sputtering in various oxygen partial pressures

Science.gov (United States)

Tuyaerts, Romain; Poncelet, Olivier; Raskin, Jean-Pierre; Proost, Joris

2017-10-01

In this article, we propose ZnO thin films as a suitable material for piezoresistors in transparent and flexible electronics. ZnO thin films have been deposited by DC reactive magnetron sputtering at room temperature at various oxygen partial pressures. All the films have a wurtzite structure with a strong (0002) texture measured by XRD and are almost stoichiometric as measured by inductively coupled plasma optical emission spectroscopy. The effect of oxygen concentration on grain growth has been studied by in-situ multi-beam optical stress sensor, showing internal stress going from 350 MPa to -1.1 GPa. The transition between tensile and compressive stress corresponds to the transition between metallic and oxidized mode of reactive sputtering. This transition also induces a large variation in optical properties—from absorbent to transparent, and in the resistivity—from 4 × 10 - 2 Ω .cm to insulating. Finally, the piezoresistance of the thin film has been studied and showed a gauge factor (ΔR/R)/ɛ comprised between -5.8 and -8.5.

Subcutaneous emphysema, a different way to diagnose

Directory of Open Access Journals (Sweden)

Bruno José da Costa Medeiros

Full Text Available Summary Introduction: Subcutaneous emphysema (SE is a clinical condition that occurs when air gets into soft tissues under the skin. This can occur in any part of the body depending on the type of pathology. The most common site is under the skin that covers the chest wall or neck. It is characterized by painless swelling of tissues. The classic clinical sign is a crackling sensation upon touch, resembling that of touching a sponge beneath your fingers. Objective: To describe a new way to diagnose subcutaneous emphysema. Method: Our finding was a matter of serendipity while inspecting a patient with subcutaneous emphysema using a stethoscope. Instead only hearing the patient's chest, the stethoscope was gently pressed against the skin with SE and so we were able to detect a different sound. Results: This new way to diagnose subcutaneous emphysema consists in pressing the diaphragm part of stethoscope against the patient's skin where SE is supposed to be. Thus, we are able to hear a sound of small bubbles bursting. Crackle noise has an acoustic emission energy that varies between 750-1,200 Hz, considered high frequency. Conclusion: Although currently the use of imaging methods is widespread worldwide, we would like to strengthen the value of clinical examination. Auscultation is an essential diagnostic method that has become underestimated with the advances of healthcare and medicine as a whole. We therefore propose a different approach to diagnose SE.

Injectable agents affecting subcutaneous fats.

Science.gov (United States)

Chen, David Lk; Cohen, Joel L; Green, Jeremy B

2015-09-01

Mesotherapy is an intradermal or subcutaneous injection of therapeutic agents to induce local effects, and was pioneered in Europe during the 1950s. For the past 2 decades, there has been significant interest in the use of mesotherapy for minimally invasive local fat contouring. Based on the theorized lipolytic effects of the agent phosphatidylcholine, initial attempts involved its injection into subcutaneous tissue. With further studies, however, it became apparent that the activity attributed to phosphatidylcholine mesotherapy was due to the adipolytic effects of deoxycholate, a detergent used to solubilize phosphatidylcholine. Since then, clinical trials have surfaced that demonstrate the efficacy of a proprietary formulation of deoxycholate for local fat contouring. Current trials on mesotherapy with salmeterol, a b-adrenergic agonist and lipolysis stimulator, are underway-with promising preliminary results as well. ©2015 Frontline Medical Communications.

Principles of subcutaneous port placement.

Science.gov (United States)

Gonda, Shaun J; Li, Ruizong

2011-12-01

The introduction of totally implantable subcutaneous devices in the early 1980s provided patients with secure, reliable venous access and also gave them the ability to move more freely and have a more normal lifestyle with these devices in place. The most common totally implantable device used today is the subcutaneous port. These ports consist of an injection port connected to a catheter. Ports provide a number of advantages compared with other venous catheters; the most important is the reduced risk of infection. These devices have significantly lower rates of infection than nontunneled and tunneled catheters. Additional advantages include less frequent irrigation and minimal home care, and they are less prone to environmental or cutaneous contamination when not being accessed. This article will focus on the placement of these ports. Copyright © 2011 Elsevier Inc. All rights reserved.

Feasibility of subcutaneously implanted magnetic microarrays for site specific drug and gene targeting

Directory of Open Access Journals (Sweden)

M. Babincová

2010-01-01

Full Text Available The magnetic nanoparticles play a crucial role as a drug carriers in the human body. The wedge like magnetic arrays creatinga strongly non-homogeneous magnetic field are considered as a useful way to focus magnetic nanoparticles functionalizedwith various drugs or genes to desired sites. The goal of this study is to develop a numerical model of drug targetingusing subcutaneously implanted magnetic microarrays. The Finite Element Method is applied to solve partial differentialequations describing electromagnetic field (Maxwell equations and motion of these particles in a given magnetic field isobtained solving set of ordinary differential equations expressed by Newton law of motion. The results are encouragingshowing the potential to target drug to the tumour cell locally, without unwanted side effects.

Subcutaneous injections of low-dose veltuzumab (humanized anti-CD20 antibody) are safe and active in patients with indolent non-Hodgkin's lymphoma.

Science.gov (United States)

Negrea, George O; Elstrom, Rebecca; Allen, Steven L; Rai, Kanti R; Abbasi, Rashid M; Farber, Charles M; Teoh, Nick; Horne, Heather; Wegener, William A; Goldenberg, David M

2011-04-01

Subcutaneous injections of anti-CD20 antibodies may offer benefits to both patients and the healthcare system for treatment of B-cell malignancies. A pilot study was undertaken to evaluate the potential for subcutaneous dosing with 2(nd) generation anti-CD20 antibody veltuzumab in patients with CD20(+) indolent non-Hodgkin's lymphoma. Patients with previously untreated or relapsed disease received 4 doses of 80, 160, or 320 mg veltuzumab injected subcutaneously every two weeks. Responses were assessed by computed tomography scans, with other evaluations including adverse events, safety laboratories, B-cell blood levels, serum veltuzumab levels, and human anti-veltuzumab antibody (HAHA) titers. Seventeen patients (14 follicular lymphoma; 13 stage III or IV disease; 5 treatment-naive) completed treatment with only occasional, mild-moderate, transient injection reactions and no other safety issues. Subcutaneous veltuzumab demonstrated a slow release pattern over several days, achieving a mean Cmax of 19, 25 and 63 μg/mL at 80, 160, and 320 mg doses for a total of 4 administrations, respectively. Depletion of circulating B cells occurred after the first injection. The objective response rate (partial responses plus complete responses plus complete responses unconfirmed) was 47% (8/17) with a complete response/complete response unconfirmed rate of 24% (4/17); 4 of 8 objective responses continued for 60 weeks or more. All serum samples evaluated for human anti-veltuzumab antibody were negative. Subcutaneous injections of low-dose veltuzumab are convenient, well tolerated, and capable of achieving sustained serum levels, B-cell depletion, and durable objective responses in indolent non-Hodgkin's lymphoma. (Clinicaltrials.gov identifier: NCT00546793).

Relationship between arterial partial oxygen pressure after resuscitation from cardiac arrest and mortality in children.

Science.gov (United States)

Ferguson, Lee P; Durward, Andrew; Tibby, Shane M

2012-07-17

Observational studies in adults have shown a worse outcome associated with hyperoxia after resuscitation from cardiac arrest. Extrapolating from adult data, current pediatric resuscitation guidelines recommend avoiding hyperoxia. We investigated the relationship between arterial partial oxygen pressure and survival in patients admitted to the pediatric intensive care unit (PICU) after cardiac arrest. We conducted a retrospective cohort study using the Pediatric Intensive Care Audit Network (PICANet) database between 2003 and 2010 (n=122,521). Patients aged oxygen status and outcome was modeled with logistic regression, with nonlinearities explored via multivariable fractional polynomials. Covariates included age, sex, ethnicity, congenital heart disease, out-of-hospital arrest, year, Pediatric Index of Mortality-2 (PIM2) mortality risk, and organ supportive therapies. Of 1875 patients, 735 (39%) died in PICU. Based on the first arterial gas, 207 patients (11%) had hyperoxia (Pa(O)(2) ≥300 mm Hg) and 448 (24%) had hypoxia (Pa(O)(2) <60 mm Hg). We found a significant nonlinear relationship between Pa(O)(2) and PICU mortality. After covariate adjustment, risk of death increased sharply with increasing hypoxia (odds ratio, 1.92; 95% confidence interval, 1.80-2.21 at Pa(O)(2) of 23 mm Hg). There was also an association with increasing hyperoxia, although not as dramatic as that for hypoxia (odds ratio, 1.25; 95% confidence interval, 1.17-1.37 at 600 mm Hg). We observed an increasing mortality risk with advancing age, which was more pronounced in the presence of congenital heart disease. Both severe hypoxia and, to a lesser extent, hyperoxia are associated with an increased risk of death after PICU admission after cardiac arrest.

Changes in Oxygen Partial Pressure in the Vitreous Body and Arterial Blood of Rabbits Depending on Oxygen Concentration in Inspired Mixture.

Science.gov (United States)

Amkhanitskaya, L I; Nikolaeva, G V; Sokolova, N A

2015-07-01

We demonstrated that the vitreous body of one-month-old rabbits becomes a "reservoir" for storage and accumulation of oxygen after exposure to additional oxygenation of the organism (O2 concentrations in inspired gas mixture were 40, 60, 85, and 99%). The higher was O2 concentration in inspired mixture, the higher was oxygen saturation of the blood and vitreous body. O2 concentration of 40% was relatively safe for eye tissues. O2 concentration >60% induced oxygen accumulation in the vitreous body, which can be a provoking factor for the development of oxygen-induced pathologies.

Subcutaneous blood flow in man during sleep with continous epdural anaesthesia

DEFF Research Database (Denmark)

Sindrup, JH; Petersen, Lars Jelstrup; Kastrup, Jens

1996-01-01

BACKGROUND: Subcutaneous blood flow increases during sleep and we evaluated if this increase is affected by epidural anaesthesia. METHODS: Lower leg subcutaneous blood flow was determined by 133Xenon clearance in ten subjects during continous epidural anaesthesia at L2-L3 including eight hours...... of sleep, while the opper abdominal subcutaneous blood flow served as control. RESULTS: Epidural anaesthesia to the level of the umbilicus was followed by an increase in the lower leg subcutaneous blood flow fra 3.4 (1.8-6.3) to 7.8 (3.6-16.9) ml min-1 (median and range; P....4-7.6) ml min-1 100 g-1 after 88 (45-123) min. In contrast, until the period of sleep the upper abdominal region blood flow remained at 5.2 (3.2-6.4) ml min-1 100 g-1. During sleep, lower leg subcutaneous blood flow did not change significantly, but the upper abdominal flow increased to 6.2 (5.2-7.2) ml min...

Subcutaneous phaeohyphomycosis due to Pyrenochaeta romeroi mimicking a synovial cyst

Directory of Open Access Journals (Sweden)

Aurelien Dinh

2016-08-01

Full Text Available Opportunistic subcutaneous fungal infections are increasing nowadays due to the growing number of medical conditions causing immunosuppression, especially organ transplant. The incidence rate of subcutaneous phaeohyphomycosis is very low. Most studies found are case reports. They showed a wide variation of clinical presentations. Pyrenochaeta romeroi, a fungus from the Dematiaceae group is a saprophyte found in soil and plants and a possible causative agent of phaeohyphomycosis. We present a rare case of subcutaneous phaeohyphomycosis caused by P. romeroi mimicking a synovial cyst in a diabetic patient.

Spontaneous subcutaneous emphysema of the scalp following hair coloring/treatment

Directory of Open Access Journals (Sweden)

Sanjit O. Tewari, MD

2017-03-01

Full Text Available Subcutaneous emphysema of the scalp is a process often attributed to secondary factors such as trauma, infection, or a myriad of iatrogenic etiologies. Here, we are presenting a case report of an adult patient with spontaneous subcutaneous emphysema of the scalp following a hair coloring/treatment. We performed an extensive review of literature on this topic, however, could not find a single case with similar presentation of subcutaneous emphysema. This case demonstrates an unreported etiology for this diagnosis and is thus being reported for its uniqueness and to raise clinical awareness.

Symptomatic Tarlov Cysts: Surgical Treatment by Subcutaneous Infusion Port.

Science.gov (United States)

Huang, Ying; Zhu, Tong; Lin, Hongyi; Li, Jing; Zeng, Tao; Lin, Jian

2018-05-01

The treatment of Tarlov cysts is challenging and difficult. The objective of our study was to describe the security and efficacy of the subcutaneous infusion port for drainage of symptomatic Tarlov cysts. The authors executed a retrospective review of data from 5 symptomatic Tarlov cysts patients who were treated using a subcutaneous infusion port from June 2014 to July 2017. Numerical Rating Scale scores and the Japanese Orthopedic Association scores of back pain were analyzed. Complications and adverse effects on postoperative days 1, 7, 14, and 28 were also analyzed. The mean follow-up was 12.6 months. Five adults (3 females and 2 males) who had been symptomatic received a subcutaneous infusion port. After treatment, all patients experienced pain relief and pain alleviation lasted from 1 day to 3 years without complications and adverse effects. A subcutaneous infusion port is a useful treatment option for symptomatic Tarlov cysts. When the patients' symptoms returned and the cysts repressurized, we quickly and simply drained the cysts by using the infusion port. Copyright © 2018 Elsevier Inc. All rights reserved.

The effects of arterial carbon dioxide partial pressure and sevoflurane on capillary venous cerebral blood flow and oxygen saturation during craniotomy.

Science.gov (United States)

Klein, Klaus Ulrich; Glaser, Martin; Reisch, Robert; Tresch, Achim; Werner, Christian; Engelhard, Kristin

2009-07-01

Intraoperative routine monitoring of cerebral blood flow and oxygenation remains a technological challenge. Using the physiological principle of carbon dioxide reactivity of cerebral vasculature, we investigated a recently developed neuromonitoring device (oxygen-to-see, O2C device) for simultaneous measurements of regional cerebral blood flow (rvCBF), blood flow velocity (rvVelo), oxygen saturation (srvO2), and hemoglobin amount (rvHb) at the capillary venous level in patients subjected to craniotomy. Twenty-six neurosurgical patients were randomly assigned to anesthesia with 1.4% or 2.0% sevoflurane end-tidal concentration. After craniotomy, a fiberoptic probe was applied on a macroscopically healthy surface of cerebral tissue next to the site of surgery. Simultaneous measurements in 2 and 8 mm cerebral depth were performed in each patient during lower (35 mm Hg) and higher (45 mm Hg) levels (random order) of arterial carbon dioxide partial pressure (PaCO2). The principle of these measurements relies on the combination of laser-Doppler flowmetry (rvCBF, rvVelo) and photo-spectrometry (srvO2, rvHb). Linear models were fitted to test changes of end points (rvCBF, rvVelo, srvO2, rvHb) in response to lower and higher levels of PaCO2, 1.4% and 2.0% sevoflurane end-tidal concentration, and 2 and 8 mm cerebral depth. RvCBF and rvVelo were elevated by PaCO2 independent of sevoflurane concentration in 2 and 8 mm depth of cerebral tissue (P oxygen was decreased by elevated PaCO2. Unchanged levels of rvHb signify that there was no blood loss during measurements. Data suggest that the device allows detection of local changes in blood flow and oxygen saturation in response to different PaCO2 levels in predominant venous cerebral microvessels.

Response behaviour of oxygen sensing solid electrolytes

NARCIS (Netherlands)

Winnubst, Aloysius J.A.; Scharenborg, A.H.A.; Burggraaf, A.J.

1985-01-01

The response time (t r) after a step change in oxygen partial pressure was investigated for some solid electrolytes used in Nernst type oxygen sensors. The electrolyte as well as the (porous) electrode material affect the value oft r. Stabilized Bi2O3 materials exhibit slower response rates (largert

Filterability of freshly-collected sickle erythrocytes under venous oxygen pressure without exposure to air.

Science.gov (United States)

Shah, Siddharth; Acholonu, Rhonda Graves; Ohene-Frempong, Kwaku; Asakura, Toshio

2015-12-01

We previously found that blood samples collected from steady-state patients with sickle cell disease (SCD) without exposure to air contain a new type of reversibly sickled cells (RSCs) with blunt edges at a level of as high as 78%. Since partial oxygenation of once-deoxygenated sickled cells with pointy edges to near venous oxygen pressure generates similar sickled cells with blunt edges in vitro, we named them as partially oxygenated sickled cells (POSCs). On the other hand, partial deoxygenation of once-oxygenated SS cells to venous oxygen pressure generates partially deoxygenated sickled cells (PDSCs) with pointy edges. In this study, we obtained blood samples from 6 steady-state patients with SCD under venous oxygen pressure without exposure to air, subjected them to various oxygenation/deoxygenation/reoxygenation cycles, and studied their filterability through a membrane filter with pore diameter of 3μm, the theoretical minimum diameter of a capillary. Our results indicated that discocytes, POSCs with blunt edges, and irreversibly sickled cells could deform and pass through the filter, while PDSCs with pointy edges were rigid and could not. The filterability of SS cells seems to be related to the length and amount of deoxy-hemoglobin S fibers in the cells. Copyright © 2015. Published by Elsevier Inc.

Fabrication of subcutaneous veins phantom for vessel visualization system

Science.gov (United States)

Cheng, Kai; Narita, Kazuyuki; Morita, Yusuke; Nakamachi, Eiji; Honda, Norihiro; Awazu, Kunio

2013-09-01

The technique of subcutaneous veins imaging by using NIR (Near Infrared Radiation) is widely used in medical applications, such as the intravenous injection and the blood sampling. In the previous study, an automatic 3D blood vessel search and automatic blood sampling system was newly developed. In order to validate this NIR imaging system, we adopted the subcutaneous vein in the human arm and its artificial phantom, which imitate the human fat and blood vessel. The human skin and subcutaneous vein is characterized as the uncertainty object, which has the individual specificity, non-accurate depth information, non-steady state and hardly to be fixed in the examination apparatus. On the other hand, the conventional phantom was quite distinct from the human's characteristics, such as the non-multilayer structure, disagreement of optical property. In this study, we develop a multilayer phantom, which is quite similar with human skin, for improvement of NIR detection system evaluation. The phantom consists of three layers, such as the epidermis layer, the dermis layer and the subcutaneous fat layer. In subcutaneous fat layer, we built a blood vessel. We use the intralipid to imitate the optical scattering characteristics of human skin, and the hemoglobin and melanin for the optical absorption characteristics. In this study, we did two subjects. First, we decide the fabrication process of the phantom. Second, we compared newly developed phantoms with human skin by using our NIR detecting system, and confirm the availability of these phantoms.

Subcutaneous Fascial Bands—A Qualitative and Morphometric Analysis

Science.gov (United States)

Li, Weihui; Ahn, Andrew C.

2011-01-01

Background Although fascial bands within the subcutaneous (SQ) layer are commonly seen in ultrasound images, little is known about their functional role, much less their structural characteristics. This study's objective is to describe the morphological features of SQ fascial bands and to systematically evaluate the bands using image analyses tools and morphometric measures. Methods In 28 healthy volunteers, ultrasound images were obtained at three body locations: the lateral aspect of the upper arm, medial aspect of the thigh and posterior aspect of lower leg. Using image analytical techniques, the total SQ band area, fascial band number, fascial band thickness, and SQ zone (layer) thickness were determined. In addition, the SQ spatial coherence was calculated based on the eigenvalues associated with the largest and smallest eigenvectors of the images. Results Fascial bands at these sites were contiguous with the dermis and the epimysium forming an interconnected network within the subcutaneous tissue. Subcutaneous blood vessels were also frequently encased by these fascial bands. The total SQ fascial band area was greater at the thigh and calf compared to the arm and was unrelated to SQ layer (zone) thickness. The thigh was associated with highest average number of fascial bands while calf was associated with the greatest average fascial band thickness. Across body regions, greater SQ zone thickness was associated with thinner fascial bands. SQ coherence was significantly associated with SQ zone thickness and body location (calf with statistically greater coherence compared to arm). Conclusion Fascial bands are structural bridges that mechanically link the skin, subcutaneous layer, and deeper muscle layers. This cohesive network also encases subcutaneous vessels and may indirectly mediate blood flow. The quantity and morphological characteristics of the SQ fascial band may reflect the composite mechanical forces experienced by the body part. PMID:21931632

Homozygous LIPE Mutation in Siblings with Multiple Symmetric Lipomatosis, Partial Lipodystrophy, and Myopathy

OpenAIRE

Zolotov, Sagit; Xing, Chao; Mahamid, Riad; Shalata, Adel; Sheikh-Ahmad, Mohammed; Garg, Abhimanyu

2016-01-01

Despite considerable progress in identifying causal genes for lipodystrophy syndromes, the molecular basis of some peculiar adipose tissue disorders remains obscure. In an Israeli–Arab pedigree with a novel autosomal recessive, multiple symmetric lipomatosis (MSL), partial lipodystrophy and myopathy, we conducted exome sequencing of two affected siblings to identify the disease-causingmutation. The 41-year-old female proband and her 36-year-old brother reported marked accumulation of subcutan...

Influence of Partial Pressure of Oxygen in Blood Samples on Measurement Performance in Glucose-Oxidase-Based Systems for Self-Monitoring of Blood Glucose

Science.gov (United States)

Baumstark, Annette; Schmid, Christina; Pleus, Stefan; Haug, Cornelia; Freckmann, Guido

2013-01-01

Background Partial pressure of oxygen (pO2) in blood samples can affect blood glucose (BG) measurements, particularly in systems that employ the glucose oxidase (GOx) enzyme reaction on test strips. In this study, we assessed the impact of different pO2 values on the performance of five GOx systems and one glucose dehydrogenase (GDH) system. Two of the GOx systems are labeled by the manufacturers to be sensitive to increased blood oxygen content, while the other three GOx systems are not. Methods Aliquots of 20 venous samples were adjusted to the following pO2 values: pO2 ~70 mmHg, which is considered to be similar to pO2 in capillary blood samples, and the mean BG result at pO2 pO2 pO2 ≥150 mmHg. For both pO2 levels, relative differences of all tested GOx systems were significant (p pO2 values pO2 variations lead to clinically relevant BG measurement deviations in GOx systems, even in GOx systems that are not labeled as being oxygen sensitive. PMID:24351177

Subcutaneous injections of low-dose veltuzumab (humanized anti-CD20 antibody) are safe and active in patients with indolent non-Hodgkin’s lymphoma

Science.gov (United States)

Negrea, George O.; Elstrom, Rebecca; Allen, Steven L.; Rai, Kanti R.; Abbasi, Rashid M.; Farber, Charles M.; Teoh, Nick; Horne, Heather; Wegener, William A.; Goldenberg, David M.

2011-01-01

Background Subcutaneous injections of anti-CD20 antibodies may offer benefits to both patients and the healthcare system for treatment of B-cell malignancies. Design and Methods A pilot study was undertaken to evaluate the potential for subcutaneous dosing with 2nd generation anti-CD20 antibody veltuzumab in patients with CD20+ indolent non-Hodgkin’s lymphoma. Patients with previously untreated or relapsed disease received 4 doses of 80, 160, or 320 mg veltuzumab injected subcutaneously every two weeks. Responses were assessed by computed tomography scans, with other evaluations including adverse events, safety laboratories, B-cell blood levels, serum veltuzumab levels, and human anti-veltuzumab antibody (HAHA) titers. Results Seventeen patients (14 follicular lymphoma; 13 stage III or IV disease; 5 treatment-naive) completed treatment with only occasional, mild-moderate, transient injection reactions and no other safety issues. Subcutaneous veltuzumab demonstrated a slow release pattern over several days, achieving a mean Cmax of 19, 25 and 63 μg/mL at 80, 160, and 320 mg doses for a total of 4 administrations, respectively. Depletion of circulating B cells occurred after the first injection. The objective response rate (partial responses plus complete responses plus complete responses unconfirmed) was 47% (8/17) with a complete response/complete response unconfirmed rate of 24% (4/17); 4 of 8 objective responses continued for 60 weeks or more. All serum samples evaluated for human anti-veltuzumab antibody were negative. Conclusions Subcutaneous injections of low-dose veltuzumab are convenient, well tolerated, and capable of achieving sustained serum levels, B-cell depletion, and durable objective responses in indolent non-Hodgkin’s lymphoma. (Clinicaltrials.gov identifier: NCT00546793) PMID:21173095

Resistance-Based Ceramic Ho123 Ionic Conductor for Oxygen Gas Sensing

Science.gov (United States)

Idrus, L. H.; Yahya, A. K.

2009-07-01

Oxygen sensing properties of HoBa2Cu3O7-δ ceramic rods utilizing hot-spot phenomenon have been characterized. The rods were prepared from high purity oxides using the conventional solid-state reaction method. I-V characterization showed increase in output current with voltage before the appearance of the hot spot. After the appearance of the hot-spot, the output current strongly depended on oxygen partial pressure. The rod showed stable sensing characteristics with good electrical stability and reproducibility with higher sensitivity at low oxygen partial pressure. The sensing property is associated with the absorption of oxygen and dissociation into holes and oxide ions. Ho123 is more sensitive at pO2 below 20% compared to Er123 possibly due to differences in oxygen activation energy related to RE ionic radius.

Resistance-Based Ceramic Ho123 Ionic Conductor for Oxygen Gas Sensing

International Nuclear Information System (INIS)

Idrus, L. H.; Yahya, A. K.

2009-01-01

Oxygen sensing properties of HoBa 2 Cu 3 O 7-δ ceramic rods utilizing hot-spot phenomenon have been characterized. The rods were prepared from high purity oxides using the conventional solid-state reaction method. I-V characterization showed increase in output current with voltage before the appearance of the hot spot. After the appearance of the hot-spot, the output current strongly depended on oxygen partial pressure. The rod showed stable sensing characteristics with good electrical stability and reproducibility with higher sensitivity at low oxygen partial pressure. The sensing property is associated with the absorption of oxygen and dissociation into holes and oxide ions. Ho123 is more sensitive at pO 2 below 20% compared to Er123 possibly due to differences in oxygen activation energy related to RE ionic radius.

Chemical polishing of partially oxidized T-111 alloy

International Nuclear Information System (INIS)

Teaney, P.E.

1974-01-01

The specimens were pressure-mounted in Bakelite and ground through 600 grit on silicon carbide papers. The specimens were rough-polished on a vibratory polisher for 4 to 6 h, using a water slurry of one micron alumina on Texmet, followed by 0.3-μ alumina on Texmet overnight. Final polishing was accomplished by continuous swabbing with a chemical polish. A chemical polish consisting of ten parts lactic acid, four parts nitric acid, and four parts hydrofluoric acid worked well for the T-111 parent material specimens; however, in the partially oxidized specimens, considerable pitting and staining occurred in the oxygen-affected zone and in the transition zone between the oxygen-affected zone and the parent material. A chemical polish was developed for the partially oxidized specimens by adjusting the ratio of the acids to ten parts lactic acid, two parts nitric acid, and two parts hydrofluoric acid. This slowed the chemical attack on the oxygen-affected zone considerably and, with continuous swabbing, the pitting and stain could be avoided. The specimens were rinsed and checked occasionally on the metallograph to determine when the proper polish had been obtained. Some specimens required intermittent polishing times up to 1 / 2 hour. No relationship could be established between the oxygen content of the specimen and the time required for chemical polishing in the partially oxidized specimens. However, the microstructure of the transition zone was the most difficult to obtain, and specimens with uniform reaction zones across the width of the specimen polished quicker than those with the transition zone

Model Study of the Pressure Build-Up during Subcutaneous Injection

DEFF Research Database (Denmark)

Thomsen, Maria; Hernandez Garcia, Anier; Mathiesen, Joachim

2014-01-01

In this study we estimate the subcutaneous tissue counter pressure during drug infusion from a series of injections of insulin in type 2 diabetic patients using a non-invasive method. We construct a model for the pressure evolution in subcutaneous tissue based on mass continuity and the flow laws...

Subcutaneous Emphysema, Pneumomediastinum, Pneumoretroperitoneum, and Pneumoscrotum: Unusual Complications of Acute Perforated Diverticulitis

Directory of Open Access Journals (Sweden)

S. Fosi

2014-01-01

Full Text Available Pneumomediastinum, and subcutaneous emphysema usually result from spontaneous alveolar wall rupture and, far less commonly, from disruption of the upper airways or gastrointestinal tract. Subcutaneous neck emphysema, pneumomediastinum, and retropneumoperitoneum caused by nontraumatic perforations of the colon have been infrequently reported. The main symptoms of spontaneous subcutaneous emphysema are swelling and crepitus over the involved site; further clinical findings in case of subcutaneous cervical and mediastinal emphysema can be neck and chest pain and dyspnea. Radiological imaging plays an important role to achieve the correct diagnosis and extension of the disease. We present a quite rare case of spontaneous subcutaneous cervical emphysema, pneumomediastinum, and pneumoretroperitoneum due to perforation of an occult sigmoid diverticulum. Abdomen ultrasound, chest X-rays, and computer tomography (CT were performed to evaluate the free gas extension and to identify potential sources of extravasating gas. Radiological diagnosis was confirmed by the subsequent surgical exploration.

Robust high temperature oxygen sensor electrodes

DEFF Research Database (Denmark)

Lund, Anders

Platinum is the most widely used material in high temperature oxygen sensor electrodes. However, platinum is expensive and the platinum electrode may, under certain conditions, suffer from poisoning, which is detrimental for an oxygen sensor. The objective of this thesis is to evaluate electrode...... materials as candidates for robust oxygen sensor electrodes. The present work focuses on characterising the electrochemical properties of a few electrode materials to understand which oxygen electrode processes are limiting for the response time of the sensor electrode. Three types of porous platinum......-Dansensor. The electrochemical properties of the electrodes were characterised by electrochemical impedance spectroscopy (EIS), and the structures were characterised by x-ray diffraction and electron microscopy. At an oxygen partial pressures of 0.2 bar, the response time of the sensor electrode was determined by oxygen...

Oxygen permeation flux through La1-ySryFeO3 limited by the carbon monoxide oxidation rate

NARCIS (Netherlands)

van Hassel, B.A.; van Hassel, B.A.; ten Elshof, Johan E.; Bouwmeester, Henricus J.M.

1995-01-01

The oxygen permeation flux through La1-ySryFeO3-δ (y = 0.1, 0.2) in a large oxygen partial pressure gradient (air/CO, CO2 mixture) was found to be limited by the carbon monoxide oxidation rate at the low oxygen partial pressure side of the membrane. The oxygen permeation flux through the membrane

Numerical simulation of kinetic demixing and decomposition in a LaCoO3-δ oxygen membrane under an oxygen potential gradient

DEFF Research Database (Denmark)

Ta, Na; Chen, Ming; Zhang, Lijun

2018-01-01

A composition- and temperature-dependent mobility database of all ionic species in the LaCoO3-δ phase was developed and combined with a La-Co-O thermodynamic database to simulate kinetic demixing and partial decomposition in LaCoO3-δ oxygen membranes operated under a 0.0001/0.21 bar oxygen partial...... pressure difference at 1073 K for 1 year. Formation of La2O3, Co3O4 and CoO phases across the membrane is predicted. The kinetic demixing process can be divided into two stages, namely, establishment of the oxygen potential gradient (fast) and demixing of the cations (slow); the former is controlled...... by the mobility of oxygen ions, and the latter is determined by the higher mobility of Co ions as compared to the La ion in the ABO3-type perovskite. A drift motion of both oxide surfaces towards the high PO2 side occurs with the movement of cations....

Human Decompression Trial With 1.3 ATA Oxygen in Helium

National Research Council Canada - National Science Library

1998-01-01

The Naval Medical Research Institute (NMRI) was tasked to develop helium-oxygen decompression tables for a proposed closed circuit breathing apparatus which Will deliver a constant oxygen partial pressure of 1.3 atmospheres (ATA...

Regional perfusion and oxygenation of tumors upon methylxanthine derivative administration

International Nuclear Information System (INIS)

Kelleher, Debra K.; Thews, Oliver; Vaupel, Peter

1998-01-01

Purpose: The use of methylxanthine derivatives has been postulated as a means of increasing tumor perfusion and thus ameliorating tumor hypoxia. The aim of this study was to quantify and compare the effects of three methylxanthine derivatives: pentoxifylline (PX), torbafylline (TB), and HWA 138 (HW) on tumor perfusion and oxygenation. Methods and Materials: Anesthetized Sprague Dawley rats with DS-sarcomas implanted subcutaneously onto the hind foot dorsum were used in this study. Mean arterial blood pressure (MABP) was measured throughout experiments. Regional red blood cell (RBC) flux was monitored using a multichannel laser Doppler device and tumor oxygenation on a more global level was assessed polarographically using an O 2 -sensitive catheter electrode. The methylxanthine derivatives were administered as a single dose intraperitoneally (for PX 50 mg/kg; for TB and HW 75 mg/kg). Results: Following drug administration, initial decreases in MABP down to 75% of baseline values were observed for all three substances. PX, HW, and TB caused initial transient reductions in mean RBC flux followed by gradual increases to values of 137 ± 27 %, 139 ± 14 %, and 122 ± 14 % respectively at t = 60 min. Following a small initial decrease upon drug administration, O 2 partial pressure (pO 2 ) rose to 160 ± 31 %, 153 ± 34 %, and 121 ± 11 % for PX, HW, and TB, respectively at t = 60 min. At the end of the observation period (t = 90 min), increases in RBC flux and pO 2 were still evident. When individual tumors were considered, a variety of patterns (including opposing effects) for changes in RBC flux were seen, not necessarily reflected in the mean values. Thus, while the methylxanthine derivatives caused an increased average tumor perfusion, there is evidence suggesting that a redistribution of tumor blood flow occurs which may amplify preexisting heterogeneity. Conclusions: Substantial improvements in tumor oxygenation and perfusion were observed after administration of

Continuous subcutaneous insulin infusion in diabetes: patient populations, safety, efficacy, and pharmacoeconomics

OpenAIRE

Pozzilli, Paolo; Battelino, Tadej; Danne, Thomas; Hovorka, Roman; Jarosz?Chobot, Przemyslawa; Renard, Eric

2015-01-01

Summary The level of glycaemic control necessary to achieve optimal short?term and long?term outcomes in subjects with type 1 diabetes mellitus (T1DM) typically requires intensified insulin therapy using multiple daily injections or continuous subcutaneous insulin infusion. For continuous subcutaneous insulin infusion, the insulins of choice are the rapid?acting insulin analogues, insulin aspart, insulin lispro and insulin glulisine. The advantages of continuous subcutaneous insulin infusion ...

Study of atomic excitations in sputtering with targets partially covered with oxygen

International Nuclear Information System (INIS)

Weng, J.; Veje, E.

1984-01-01

We have bombarded pure, elemental targets of Be, B, Mg, Al, Si, Ti, and Au with 80 keV Ar + ions and studied excitation of sputtered atoms or ions under UHV conditions as well as with oxygen present at the target surface. The measurements on Mg, Al, Si, and Ti have been done at projectile incidence angles from 0 0 to 85 0 . Excitation probabilities for gold were found to be only very little influenced by oxygen, but for Be, B, Mg, Al, Si, and Ti, the excitation probabilities were in many, but not all, cases found to depend strongly on the oxygen pressure as well as on the beam current density. This indicates that the excitation mechanism is strongly dependent on the initial electronic conditions of the solid. (orig.)

Tracking of abdominal subcutaneous and preperitoneal fat mass during childhood. The Generation R Study.

Science.gov (United States)

Vogelezang, S; Gishti, O; Felix, J F; van der Beek, E M; Abrahamse-Berkeveld, M; Hofman, A; Gaillard, R; Jaddoe, V W V

2016-04-01

Overweight and obesity in early life tends to track into later life. Not much is known about tracking of abdominal fat. Our objective was to examine the extent of tracking of abdominal fat measures during the first six years of life. We performed a prospective cohort study among 393 Dutch children followed from the age of 2 years (90% range 1.9; 2.3) until the age of 6 years (90% range 5.7; 6.2). At both ages, we performed abdominal ultrasound to measure abdominal subcutaneous and preperitoneal fat distances and areas, and we calculated the preperitoneal/subcutaneous fat distance ratio. High abdominal fat measures were defined as values in the upper 15%. Abdominal subcutaneous fat distance and area, and preperitoneal fat area at 2 years were correlated with their corresponding measures at 6 years (all P-values abdominal subcutaneous fat measures. Preperitoneal fat distance at the age of 2 years was not correlated with the corresponding measure at 6 years. The tracking coefficient for preperitoneal/subcutaneous fat distance ratio from 2 to 6 years was r=0.36 (Pabdominal subcutaneous fat measures at 2 years had increased risk of having high abdominal subcutaneous fat measures at 6 years (odds ratios 9.2 (95% confidence interval (CI) 4.1-20.8) and 12.4 (95% CI 5.4-28.6) for subcutaneous fat distance and area, respectively). These associations were not observed for preperitoneal fat measures. Our findings suggest that both abdominal subcutaneous and preperitoneal fat mass measures track during childhood, but with stronger tracking for abdominal subcutaneous fat measures. An adverse abdominal fat distribution in early life may have long-term consequences.

Treatment with subcutaneous and transdermal fentanyl: results from a population pharmacokinetic study in cancer patients.

Science.gov (United States)

Oosten, Astrid W; Abrantes, João A; Jönsson, Siv; de Bruijn, Peter; Kuip, Evelien J M; Falcão, Amílcar; van der Rijt, Carin C D; Mathijssen, Ron H J

2016-04-01

Transdermal fentanyl is effective for the treatment of moderate to severe cancer-related pain but is unsuitable for fast titration. In this setting, continuous subcutaneous fentanyl may be used. As data on the pharmacokinetics of continuous subcutaneous fentanyl are lacking, we studied the pharmacokinetics of subcutaneous and transdermal fentanyl. Furthermore, we evaluated rotations from the subcutaneous to the transdermal route. Fifty-two patients treated with subcutaneous and/or transdermal fentanyl for moderate to severe cancer-related pain participated. A population pharmacokinetic model was developed and evaluated using non-linear mixed-effects modelling. For rotations from subcutaneous to transdermal fentanyl, a 1:1 dose conversion ratio was used while the subcutaneous infusion was continued for 12 h (with a 50 % tapering after 6 h). A 6-h scheme with 50 % tapering after 3 h was simulated using the final model. A one-compartment model with first-order elimination and separate first-order absorption processes for each route adequately described the data. The estimated apparent clearance of fentanyl was 49.6 L/h; the absorption rate constant for subcutaneous and transdermal fentanyl was 0.0358 and 0.0135 h(-1), respectively. Moderate to large inter-individual and inter-occasion variability was found. Around rotation from subcutaneous to transdermal fentanyl, measured and simulated plasma fentanyl concentrations rose and increasing side effects were observed. We describe the pharmacokinetics of subcutaneous and transdermal fentanyl in one patient cohort and report several findings that are relevant for clinical practice. Further research is warranted to study the optimal scheme for rotations from the subcutaneous to the transdermal route.

Subcutaneous metastasis from endometrial cancer; case report and literature review

Directory of Open Access Journals (Sweden)

Nicolae Bacalbasa

2018-05-01

Full Text Available Subcutaneous metastases from endometrial cancer are rare situations, only few cases being described so far. The main incriminated mechanisms leading to the apparition of such lesions include hematogenous and lymphatic spread. We present the case of a 66-year-old patient known with previous history of stage IIIA endometroid endometrial carcinoma initially treated by surgery and adjuvant chemotherapy who developed at 18 months follow-up a distant subcutaneous oligometastasis. At this time the patient was resubmitted to surgery, the lesion being successfully removed. The histopathological result confirmed the endometrial cancer origin of this lesion. Subcutaneous and cutaneous metastases from endometrial cancer are rare eventualities which are usually diagnosed as part of systemic dissemination of this malignancy; in these cases, the patient is only candidate for oncological treatment with palliative intent. In some cases, in which the lesions occur as oligometastatic disease, surgery might be performed with curative intent. In our case the diagnostic of the subcutaneous lesion as oligometastatic disease transformed the patient in a perfect candidate for curative oncological surgery.

Oxygen nonstoichiometry and transport properties of strontium substituted lanthanum cobaltite

DEFF Research Database (Denmark)

Søgaard, Martin; Hendriksen, Peter Vang; Mogensen, Mogens Bjerg

2006-01-01

Oxygen nonstoichiometry, structure and transport properties of the two compositions (La-0.6 Sr-0.4)(0.99)CoO3-delta (LSC40) and La0.85Sr0.15CoO3-delta (LSC15) were measured. It was found that the oxygen nonstoichiometry as a function of the temperature and oxygen partial pressure could be described...... using the itinerant electron model. The electrical conductivity, sigma, of the materials is high (sigma > 500 S cm(-1)) in the measured temperature range (650 - 1000 degrees C) and oxygen partial pressure range (0.209-10(-4) atm). At 900 degrees C the electrical conductivity is 1365 and 1491 S cm(-1......) in air for LSC40 and LSC15, respectively. A linear correlation between the electrical conductivity and the oxygen vacancy concentration was found for both samples. The mobility of the electron-holes was inversely proportional with the absolute temperature indicating a metallic type conductivity for LSC40...

Variations in alveolar partial pressure for carbon dioxide and oxygen have additive not synergistic acute effects on human pulmonary vasoconstriction.

Science.gov (United States)

Croft, Quentin P P; Formenti, Federico; Talbot, Nick P; Lunn, Daniel; Robbins, Peter A; Dorrington, Keith L

2013-01-01

The human pulmonary vasculature constricts in response to hypercapnia and hypoxia, with important consequences for homeostasis and adaptation. One function of these responses is to direct blood flow away from poorly-ventilated regions of the lung. In humans it is not known whether the stimuli of hypercapnia and hypoxia constrict the pulmonary blood vessels independently of each other or whether they act synergistically, such that the combination of hypercapnia and hypoxia is more effective than the sum of the responses to each stimulus on its own. We independently controlled the alveolar partial pressures of carbon dioxide (Paco 2) and oxygen (Pao 2) to examine their possible interaction on human pulmonary vasoconstriction. Nine volunteers each experienced sixteen possible combinations of four levels of Paco 2 (+6, +1, -4 and -9 mmHg, relative to baseline) with four levels of Pao 2 (175, 100, 75 and 50 mmHg). During each of these sixteen protocols Doppler echocardiography was used to evaluate cardiac output and systolic tricuspid pressure gradient, an index of pulmonary vasoconstriction. The degree of constriction varied linearly with both Paco 2 and the calculated haemoglobin oxygen desaturation (1-So2). Mixed effects modelling delivered coefficients defining the interdependence of cardiac output, systolic tricuspid pressure gradient, ventilation, Paco 2 and So2. No interaction was observed in the effects on pulmonary vasoconstriction of carbon dioxide and oxygen (p>0.64). Direct effects of the alveolar gases on systolic tricuspid pressure gradient greatly exceeded indirect effects arising from concurrent changes in cardiac output.

Absorption Kinetics of Subcutaneously Administered Ceftazidime in Hypoperfused Guinea Pigs

Directory of Open Access Journals (Sweden)

Tsuyoshi Ebihara, MS

2015-12-01

Conclusions: The application of MWCs or WCs enhanced subcutaneous CAZ absorption by increasing blood flow. MWCs and WCs are considered to be safe and routine methods to induce defecation after surgery on the digestive system; thus, the combination of these methods and subcutaneous CAZ administration is a potential method for treating pneumonia in patients with SMID.

Effects of oxygen on responses to heating in two lizard species sampled along an elevational gradient.

Science.gov (United States)

DuBois, P Mason; Shea, Tanner K; Claunch, Natalie M; Taylor, Emily N

2017-08-01

Thermal tolerance is an important variable in predictive models about the effects of global climate change on species distributions, yet the physiological mechanisms responsible for reduced performance at high temperatures in air-breathing vertebrates are not clear. We conducted an experiment to examine how oxygen affects three variables exhibited by ectotherms as they heat-gaping threshold, panting threshold, and loss of righting response (the latter indicating the critical thermal maximum)-in two lizard species along an elevational (and therefore environmental oxygen partial pressure) gradient. Oxygen partial pressure did not impact these variables in either species. We also exposed lizards at each elevation to severely hypoxic gas to evaluate their responses to hypoxia. Severely low oxygen partial pressure treatments significantly reduced the gaping threshold, panting threshold, and critical thermal maximum. Further, under these extreme hypoxic conditions, these variables were strongly and positively related to partial pressure of oxygen. In an elevation where both species overlapped, the thermal tolerance of the high elevation species was less affected by hypoxia than that of the low elevation species, suggesting the high elevation species may be adapted to lower oxygen partial pressures. In the high elevation species, female lizards had higher thermal tolerance than males. Our data suggest that oxygen impacts the thermal tolerance of lizards, but only under severely hypoxic conditions, possibly as a result of hypoxia-induced anapyrexia. Copyright © 2017. Published by Elsevier Ltd.

Case Report: Pneumomediastinum and subcutaneous cervical ...

African Journals Online (AJOL)

The occurrence of pneumomediastinum and subcutaneous cervical emphysema as complications of childhood pneumonia is very unusual. They results most often from respiratory manoeuvres that produce high intrathoracic pressure. Although they are largely benign, pneumomediastinum can cause compression of major ...

A method for measuring brain partial pressure of oxygen in unanesthetized unrestrained subjects: the effect of acute and chronic hypoxia on brain tissue PO(2).

Science.gov (United States)

Ortiz-Prado, E; Natah, Siraj; Srinivasan, Sathyanarayanan; Dunn, Jeff F

2010-11-30

The level of tissue oxygenation provides information related to the balance between oxygen delivery, oxygen utilization, tissue reactivity and morphology during physiological conditions. Tissue partial pressure of oxygen (PtO(2)) is influenced by the use of anesthesia or restraint. These factors may impact the absolute level of PtO(2). In this study we present a novel fiber optic method to measure brain PtO(2). This method can be used in unanesthetized, unrestrained animals, provides absolute values for PO(2), has a stable calibration, does not consume oxygen and is MRI compatible. Brain PtO(2) was studied during acute hypoxia, as well as before and after 28 days of high altitude acclimatization. A sensor was chronically implanted in the frontal cortex of eight Wistar rats. It is comprised of a fiber optic probe with a tip containing material that fluoresces with an oxygen dependent lifetime. Brain PtO(2) declines by 80% and 76% pre- and post-acclimatization, respectively, when the fraction of inspired oxygen declines from 0.21 to 0.08. In addition, a linear relationship between brain PtO(2) and inspired O(2) levels was demonstrated r(2)=0.98 and r(2)=0.99 (pre- and post-acclimatization). Hypoxia acclimatization resulted in an increase in the overall brain PtO(2) by approximately 35%. This paper demonstrates the use of a novel chronically implanted fiber optic based sensor for measuring absolute PtO(2). It shows a very strong linear relationship in awake animals between inspired O(2) and tissue O(2), and shows that there is a proportional increase in PtO(2) over a range of inspired values after exposure to chronic hypoxia. Copyright © 2010 Elsevier B.V. All rights reserved.

Relationship between subcutaneous blood flow and absorption of lente type insulin

DEFF Research Database (Denmark)

Hildebrant, P; Mehlsen, J; Birch, K

1987-01-01

To study the relationship between the absorption of intermediate acting insulin and the local subcutaneous blood flow (SBF) 8 diabetic patients were given subcutaneous injections of 125I labeled human lente type insulin and 133Xenon in the abdominal wall. External measurements of the tracer...

The effect of O2 partial pressure on the structure and photocatalytic property of TiO2 films prepared by sputtering

International Nuclear Information System (INIS)

Liu Baoshun; Zhao Xiujian; Zhao Qingnan; Li Chunling; He Xin

2005-01-01

The TiO 2 films were prepared on slide substrates by dc reactive magnetron sputtering at different oxygen partial pressure, and were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Fourier transform infrared spectrometry (FT-IR). The degradation of methyl orange aqueous solutions was used to evaluate the photocatalytic activity. The results show that all films show crystalline anatase structure irrespective of oxygen partial pressure. The surface oxygen element exists in three forms, the first one is TiO 2 , the second one is OH - and the last one is physical absorbed water. The films deposited at oxygen partial pressure of 0.035 and 0.040 mTorr present better photocatalytic activity, which shows clear tendency to increase with oxygen partial pressure. Such photocatalytic activity results are considered to correlate with the crystalline structure, grain sizes and the OH - concentration

Subcutaneous mercury injection by a child: A histopathology case report

Directory of Open Access Journals (Sweden)

Deepti Sukheeja

2014-01-01

Full Text Available Intentional subcutaneous injection of mercury by mentally healthy children is rare. Usually, it is seen as a part of suicidal attempt in severely depressed patients or by athletes to enhance their performance. We report a case of a 15-year-old child, inspired by a movie, who deliberately self-injected mercury subcutaneously into his forearm that led to the formation of a non-healing ulcer. Histopathology of the biopsy confirmed the diagnosis. A surgical procedure was thereby performed to treat the ulcer and reduce the blood and urinary levels of mercury. However, the patient did not develop clinical signs of chronic poisoning, proving that subcutaneous mercury injection has a low risk of systemic toxicity, and that histopathology plays an important role in diagnosis.

Clinical efficacy of sublingual and subcutaneous birch pollen allergen-specific immunotherapy

DEFF Research Database (Denmark)

Khinchi, M S; Poulsen, Lars K.; Carat, F

2004-01-01

Both sublingual allergen-specific immunotherapy (SLIT) and subcutaneous immunotherapy (SCIT) have a documented clinical efficacy, but only few comparative studies have been performed.......Both sublingual allergen-specific immunotherapy (SLIT) and subcutaneous immunotherapy (SCIT) have a documented clinical efficacy, but only few comparative studies have been performed....

Anatomy of the subcutaneous tissue of the trunk and lower extremity.

Science.gov (United States)

Markman, B; Barton, F E

1987-08-01

Dissections on 8 fresh and 10 embalmed cadavers were used to determine the anatomy of the subcutaneous adipose tissue in the trunk and extremities. These dissections, along with CT scans, confirmed Gray's original description of the subcutaneous tissue consisting of a superficial and deep adipose layer. The superficial adipose layer is contained within organized, compact fascial septa. The deep adipose layer demonstrated regional variations with respect to its fascial framework, but was contained within a relatively loose, less organized, and more widely spaced fascial septa. We observed that the adipose layers are partitioned by a discrete subcutaneous fascia which fuses with the underlying muscle fascia at particular anatomic locations. The deep layer is thus contained by the subcutaneous fascia above and the muscle fascia below to form what we termed the deep adipose compartments. The deep adipose compartments contributed significantly to overall adipose thickness, are bilateral, and are found in the abdomen and paralumbar and gluteal-thigh regions.

Oxygen potentials, oxygen diffusion coefficients and defect equilibria of nonstoichiometric (U,Pu)O{sub 2±x}

Energy Technology Data Exchange (ETDEWEB)

Kato, Masato, E-mail: kato.masato@jaea.go.jp [Fukushima Fuels and Materials Department, Japan Atomic Energy Agency, 4002 Narita-chou, O-arai machi, Ibaraki 311-1919 (Japan); Fast Reactor Fuel Cycle Technology Development Division, Japan Atomic Energy Agency, 4-33 Muramatsu Tokai-mura, Ibaraki 319-1194 (Japan); Watanabe, Masashi [Fukushima Fuels and Materials Department, Japan Atomic Energy Agency, 4002 Narita-chou, O-arai machi, Ibaraki 311-1919 (Japan); Fast Reactor Fuel Cycle Technology Development Division, Japan Atomic Energy Agency, 4-33 Muramatsu Tokai-mura, Ibaraki 319-1194 (Japan); Matsumoto, Taku; Hirooka, Shun; Akashi, Masatoshi [Fast Reactor Fuel Cycle Technology Development Division, Japan Atomic Energy Agency, 4-33 Muramatsu Tokai-mura, Ibaraki 319-1194 (Japan)

2017-04-15

Oxygen potential of (U,Pu)O{sub 2±x} was evaluated based on defect chemistry using an updated experimental data set. The relationship between oxygen partial pressure and deviation x in (U,Pu)O{sub 2±x} was analyzed, and equilibrium constants of defect formation were determined as functions of Pu content and temperature. Brouwer's diagrams were constructed using the determined equilibrium constants, and a relational equation to determine O/M ratio was derived as functions of O/M ratio, Pu content and temperature. In addition, relationship between oxygen potential and oxygen diffusion coefficients were described. - Highlights: •Brouwer’s diagrams for (U,Pu)O2 were constructed using the updated oxygen potential experimental data set. •Equilibrium constants of defect formation were determined as functions of Pu content and temperature. •Oxygen potential, oxygen diffusion coefficients, point defect concentration were described as functions of O/M ratio, Pu content and temperature.

Subcutaneous emphysema during third molar surgery: a case report.

Science.gov (United States)

Romeo, Umberto; Galanakis, Alexandros; Lerario, Francesco; Daniele, Gabriele Maria; Tenore, Gianluca; Palaia, Gaspare

2011-01-01

Extraction of third molars is the most common surgical procedure performed in oral surgery on a daily basis and, despite surgical skills and expertise, complications may occur. Complications observed during or after third molar removal may include pain, swelling, bleeding, infection, sinus perforation and nerve damage. Fortunately, with a proper management and a good surgical technique, the incidence of such events is low. Subcutaneous emphysema associated with dental extraction occurs when the air from the high-speed dental handpiece is forced into the soft tissue through the reflected flap and invades the adjacent tissues, leading to swelling, crepitus on palpation and occasionally spreading through the tissue spaces of the fascial planes. Although rare, iatrogenic subcutaneous emphysema can have serious and potentially life-threatening consequences. Care should be taken when using air-driven handpieces. The access of air into the facial tissues is not limited to tooth extractions, but may also occur through other portals of entrance, such as endodontically treated teeth, periodontium and lacerations of intraoral soft tissues. When subcutaneous emphysema occurs, it must be quickly diagnosed and properly managed to reduce the risk of further complications. This report presents a case of subcutaneous emphysema occurred during extraction of a mandibular third molar extraction with the use of an air turbine handpiece. Case management is described and issues relative to the diagnosis and prevention of this surgical complication are discussed.

A polygeneration from a dual-gas partial catalytic oxidation coupling with an oxygen-permeable membrane reactor

International Nuclear Information System (INIS)

Hao, Yanhong; Huang, Yi; Gong, Minhui; Li, Wenying; Feng, Jie; Yi, Qun

2015-01-01

Highlights: • A new polygeneration system (PL-PCO-OPMR) to DME/methanol/power is proposed. • Exergeo-economic analysis is adopted to disclose the performance of systems. • Key technological conditions and parameters for PL-PCO-OPMR are optimized. • PL-PCO-OPMR shows high energy efficiency and low CO_2 emission. • PL-PCO-OPMR is an attractive way for high efficient and clean use of COG and CGG. - Abstract: Polygeneration system, typically involving chemicals/fuels and electricity co-production, is a promising technology for the sustainable development of energy and environment. In this study, a new polygeneration system based on coal and coke oven gas (COG) inputs for co-production of dimethyl ether (DME)/methanol and electricity is proposed. In the new system, an appropriate syngas for the synthesis of DME is from coal gasified gas (CGG) reforming of COG coupled with an oxygen-permeable membrane reactor, in which both COG and CGG reforming process and fuel combustion process are incorporated, which reduces exergy destruction in the whole reforming process. In order to obtain the best performance of CO_2 reduction, energy saving and economic benefit, the key operation parameters of the proposed process are analyzed and optimized. The new system is compared with the process based on CH_4/CO_2 dry reforming, in terms of exergy efficiency, exergy cost and CO_2 emissions. Through the new system, the exergy efficiency can be increased by 7.8%, the exergy cost can be reduced by 0.88 USD/GJ and the CO_2 emission can be reduced by 0.023 kg/MJ. These results suggest that the polygeneration system from CGG and COG partial catalytic oxidation coupling with an oxygen-permeable membrane reactor (PL-PCO-OPMR) would be a more attractive way for highly efficient and clean use of CGG and COG.

Effects of Changes in Arterial Carbon Dioxide and Oxygen Partial Pressures on Cerebral Oximeter Performance.

Science.gov (United States)

Schober, Andrew; Feiner, John R; Bickler, Philip E; Rollins, Mark D

2018-01-01

Cerebral oximetry (cerebral oxygen saturation; ScO2) is used to noninvasively monitor cerebral oxygenation. ScO2 readings are based on the fraction of reduced and oxidized hemoglobin as an indirect estimate of brain tissue oxygenation and assume a static ratio of arterial to venous intracranial blood. Conditions that alter cerebral blood flow, such as acute changes in PaCO2, may decrease accuracy. We assessed the performance of two commercial cerebral oximeters across a range of oxygen concentrations during normocapnia and hypocapnia. Casmed FORE-SIGHT Elite (CAS Medical Systems, Inc., USA) and Covidien INVOS 5100C (Covidien, USA) oximeter sensors were placed on 12 healthy volunteers. The fractional inspired oxygen tension was varied to achieve seven steady-state levels including hypoxic and hyperoxic PaO2 values. ScO2 and simultaneous arterial and jugular venous blood gas measurements were obtained with both normocapnia and hypocapnia. Oximeter bias was calculated as the difference between the ScO2 and reference saturation using manufacturer-specified weighting ratios from the arterial and venous samples. FORE-SIGHT Elite bias was greater during hypocapnia as compared with normocapnia (4 ± 9% vs. 0 ± 6%; P oxygen saturation and mixed venous oxygen tension, as well as increased oxygen extraction across fractional inspired oxygen tension levels (P oxygen extraction (P < 0.0001). Changes in PaCO2 affect cerebral oximeter accuracy, and increased bias occurs with hypocapnia. Decreased accuracy may represent an incorrect assumption of a static arterial-venous blood fraction. Understanding cerebral oximetry limitations is especially important in patients at risk for hypoxia-induced brain injury, where PaCO2 may be purposefully altered.

Uranium dioxide sintering Kinetics and mechanisms under controlled oxygen potentials

International Nuclear Information System (INIS)

Freitas, C.T. de.

1980-06-01

The initial, intermediate, and final sintering stages of uranium dioxide were investigated as a function of stoichiometry and temperature by following the kinetics of the sintering reaction. Stoichiometry was controlled by means of the oxygen potential of the sintering atmosphere, which was measured continuously by solid-state oxygen sensors. Included in the kinetic study were microspheres originated from UO 2 gels and UO 2 pellets produced by isostatic pressing ceramic grade powders. The microspheres sintering behavior was examined using hot-stage microscopy and a specially designed high-temperature, controlled atmosphere furnace. This same furnace was employed as part of an optical dilatometer, which was utilized in the UO 2 pellet sintering investigations. For controlling the deviations from stoichiometry during heat treatment, the oxygen partial pressure in the sintering atmosphere was varied by passing the gas through a Cu-Ti-Cu oxygen trap. The trap temperature determined the oxygen partial pressure of the outflowing mixture. Dry hydrogen was also used in some of the UO sub(2+x) sintering experiments. The determination of diametrial shrinkages and sintering indices was made utilizing high-speed microcinematography and ultra-microbalance techniques. It was observed that the oxygen potential has a substantial influence on the kinetics of the three sintering stages. The control of the sintering atmosphere oxygen partial pressure led to very fast densification of UO sub(2+x). Values in the interval 95.0 to 99.5% of theoretical density were reached in less than one minute. Uranium volume diffusion is the dominant mechanism in the initial and intermediate sintering stages. For the final stage, uranium grain boundary diffusion was found to be the main sintering mechanism. (Author) [pt

High negative pressure subcutaneous suction drain for managing debilitating subcutaneous emphysema secondary to tube thoracostomy for an iatrogenic post computed tomography guided transthoracic needle biopsy pneumothorax: Case report and review of literature.

Science.gov (United States)

Ahmed, Zeeshan; Patel, Pinakin; Singh, Suresh; Sharma, Raj Govind; Somani, Pankaj; Gouri, Abdul Rauf; Singh, Shiv

2016-01-01

Subcutaneous emphysema is a common complication of tube thoracostomy. Though self-limiting, it should be treated when it causes palpebral closure, dyspnea, dysphagia or undue disfigurement resulting in anxiety and distress to the patient. A 72year old man who was a known case of COPD on bronchodilators developed a large pneumothorax and respiratory distress after a CT guided transthoracic lung biopsy done for a lung opacity (approx. 3×3cm) at the right hilar region on Chest X-ray. Within 24h of an urgent tube thoracostomy, patient developed intractable subcutaneous emphysema with closure of palpebral fissure and dyspnea unresponsive to increasing suction on chest tube. A subcutaneous fenestrated drain was placed mid-way between the nipple and clavicle in the mid-clavicular line bilaterally. Continuous negative suction (-150mmHg) resulted in immediate, sustained relief and complete resolution within 5days. Extensive and debilitating SE (subcutaneous emphysema) has to be treated promptly to relieve patient discomfort, dysphagia or imminent respiratory compromise. A variety of treatment have been tried including infraclavicular blow-hole incisions, subcutaneous drains +/- negative pressure suction, fenestrated angiocatheters, Vacuum assisted dressings and increasing suction on a pre-existing chest tube. We describe a high negative pressure subcutaneous suction drain which provides immediate and sustained relief in debilitating SE. Debilitating subcutaneous emphysema which causes distress, anxiety, palpebral closure, dyspnoea or dysphagia requires intervention. High negative pressure subcutaneous suction drain provides immediate and sustained relief in extensive and debilitating SE. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Immune response and reactogenicity of intradermal administration versus subcutaneous administration of varicella-zoster virus vaccine: an exploratory, randomised, partly blinded trial.

Science.gov (United States)

Beals, Chan R; Railkar, Radha A; Schaeffer, Andrea K; Levin, Yotam; Kochba, Efrat; Meyer, Brian K; Evans, Robert K; Sheldon, Eric A; Lasseter, Kenneth; Lang, Nancy; Weinberg, Adriana; Canniff, Jennifer; Levin, Myron J

2016-08-01

-response relation was observed with intradermal administration (1/3 dose subcutaneous GMFR 1·64 [90% CI 1·36-1·99], 1/3 dose intradermal 2·58 (2·13-3·13), 1/10 dose intradermal 2·22 [1·83-2·69], and 1/27 dose intradermal 1·64 [1·35-2·00]). Each partial dose of zoster vaccine given intradermaly had a gpELISA GMFR comparable to that of full dose zoster vaccine given subcutaneously. Transient erythema and induration were more common after intradermal administration (31% erythema for full subcutaneous dose and 77% for intradermal dose). Intradermal zoster vaccine showed a greater increase in varicella-zoster virus gpELISA antibody compared with subcutaneous zoster vaccine at comparable doses. Larger and longer studies of intradermal administration of live, attenuated zoster vaccine are needed to provide convincing evidence of improved cell mediated immunity. Merck & Co Inc. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ratiometric reactive oxygen species nanoprobe for noninvasive in vivo imaging of subcutaneous inflammation/infection

OpenAIRE

Zhou, Jun; Weng, Hong; Huang, Yihui; Gu, Yueqing; Tang, Liping; Hu, Wenjing

2016-01-01

Release of reactive oxygen species (ROS) accompanied with acute inflammation and infection often results in cell death and tissue injury. Several ROS-reactive bioluminescent probes have been investigated in recent years to detect ROS activity in vivo. Unfortunately, these probes cannot be used to quantify the degree of ROS activity and inflammatory responses due to the fact that the extent of the bioluminescent signals is also probe-concentration dependent. To address this challenge, we fabri...

Ultrasound-guided drainage of subcutaneous abscesses on the trunk is feasible

DEFF Research Database (Denmark)

Kjær, Søren; Rud, Bo; Bay-Nielsen, Morten

2013-01-01

Subcutaneous trunk abscesses are frequent, and current treatment options generally involve incision. By contrast, the standard care for breast abcesses is ultrasound-guided drainage. The aim of this study was to evaluate the feasibility of ultrasound-guided drainage combined with antibiotics...... in the treatment of subcutaneous abscesses on the trunk....

Intraportal islet oxygenation.

Science.gov (United States)

Suszynski, Thomas M; Avgoustiniatos, Efstathios S; Papas, Klearchos K

2014-05-01

Islet transplantation (IT) is a promising therapy for the treatment of diabetes. The large number of islets required to achieve insulin independence limit its cost-effectiveness and the number of patients who can be treated. It is believed that >50% of islets are lost in the immediate post-IT period. Poor oxygenation in the early post-IT period is recognized as a possible reason for islet loss and dysfunction but has not been extensively studied. Several key variables affect oxygenation in this setting, including (1) local oxygen partial pressure (pO(2)), (2) islet oxygen consumption, (3) islet size (diameter, D), and (4) presence or absence of thrombosis on the islet surface. We discuss implications of oxygen-limiting conditions on intraportal islet viability and function. Of the 4 key variables, the islet size appears to be the most important determinant of the anoxic and nonfunctional islet volume fractions. Similarly, the effect of thrombus formation on the islet surface may be substantial. At the University of Minnesota, average size distribution data from clinical alloislet preparations (n = 10) indicate that >150-µm D islets account for only ~30% of the total islet number, but >85% of the total islet volume. This suggests that improved oxygen supply to the islets may have a profound impact on islet survivability and function since most of the β-cell volume is within large islets which are most susceptible to oxygen-limiting conditions. The assumption that the liver is a suitable islet transplant site from the standpoint of oxygenation should be reconsidered. © 2014 Diabetes Technology Society.

A theoretical model for the effects of reduced hemoglobin-oxygen affinity on tumor oxygenation

International Nuclear Information System (INIS)

Kavanagh, Brian D.; Secomb, Timothy W.; Hsu, Richard; Lin, P.-S.; Venitz, Jurgen; Dewhirst, Mark W.

2002-01-01

Purpose: To develop a theoretical model for oxygen delivery to tumors, and to use the model to simulate the effects of changing the affinity of hemoglobin for oxygen on tumor oxygenation. Methods and Materials: Hemoglobin affinity is expressed in terms of P 50 , the partial pressure of oxygen (Po 2 ) at half saturation. Effects of changing P 50 on arterial Po 2 are predicted using an effective vessel approach to describe diffusive oxygen transport in the lungs, assuming fixed systemic oxygen demand and fixed blood flow rate. The decline in oxygen content of blood as it flows through normal tissue before entering the tumor region is assumed fixed. The hypoxic fraction of the tumor region is predicted using a three-dimensional simulation of diffusion from a network of vessels whose geometry is derived from observations of tumor microvasculature in the rat. Results: In air-breathing rats, predicted hypoxic fraction decreases with moderate increases in P 50 , but increases with further increases of P 50 , in agreement with previous experimental results. In rats breathing hyperoxic gases, and in humans breathing either normoxic or hyperoxic gases, increased P 50 is predicted to improve tumor oxygenation. Conclusions: The results support the administration of synthetic agents to increase P 50 during radiation treatment of tumors

Oxygen, the lung and the diver: friends and foes?

NARCIS (Netherlands)

van Ooij, Pieter-Jan A. M.; Sterk, Peter J.; van Hulst, Robert A.

2016-01-01

Worldwide, the number of professional and sports divers is increasing. Most of them breathe diving gases with a raised partial pressure of oxygen (PO2). However, if the PO2 is between 50 and 300 kPa (375-2250 mmHg) (hyperoxia), pathological pulmonary changes can develop, known as pulmonary oxygen

Mathematical modeling of oxygen transport in solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Svensson, Ann Mari

1997-12-31

This thesis develops mathematical models to describe the electrochemical performance of a solid oxide fuel cell cathode based on electrochemical kinetics and mass transfer. The individual effects of various coupled processes are investigated. A one-dimensional model is developed based on porous electrode theory. Two different mechanisms are investigated for the charge transfer reaction. One of these assumes that intermediately adsorbed oxygen atoms are reduced at the electrode/electrolyte interface, similar to the models proposed for metal electrodes. Simulated polarization curves exhibit limited currents due to depletion of oxygen adsorbates at high cathodic overvoltages. An empirical correlation is confirmed to exist between the limiting current an the oxygen partial pressure, however, a similar correlation often assumed to exist between the measured polarization resistance and the oxygen partial pressure could not be justified. For the other model, oxygen vacancies are assumed to be exchanged directly at the electrode/electrolyte interface. The electrochemical behaviour is improved by reducing the oxygen partial pressure, due to increased vacancy concentration of the electrode material. Simulated polarization curves exhibit Tafel-like slopes in the cathodic direction, which are due to polarization concentration, and not activation polarization in the conventional sense. Anodic limiting currents are predicted due to lack of available free sites for vacancy exchange at the cathode side. The thesis also presents a theoretical treatment of current and potential distributions in simple two-dimensional cell geometries, and a two-dimensional model for a porous electrode-electrolyte system for investigation of the effect of interfacial diffusion of adsorbates along the electrode/electrolyte interface. 172 refs., 60 figs., 11 tabs.

Oxygen effect of transparent conducting amorphous Indium Zinc Tin Oxide films on Polyimide substrate for flexible electrode

International Nuclear Information System (INIS)

Ko, Yoon Duk; Lee, Chang Hun; Moon, Doo Kyung; Kim, Young Sung

2013-01-01

This paper discusses the effect of oxygen on the transparent conducting properties and mechanical durability of the amorphous indium zinc tin oxide (IZTO) films. IZTO films deposited on flexible clear polyimide (PI) substrate using pulsed direct current (DC) magnetron sputtering at room temperature under various oxygen partial pressures. All IZTO films deposited at room temperature exhibit an amorphous structure. The electrical and optical properties of the IZTO films were sensitively influenced by oxygen partial pressures. At optimized deposition condition of 3.0% oxygen partial pressure, the IZTO film shows the lowest resistivity of 6.4 × 10 −4 Ωcm, high transmittance of over 80% in the visible range, and figure of merit value of 3.6 × 10 −3 Ω −1 without any heat controls. In addition, high work function and good mechanical flexibility of amorphous IZTO films are beneficial to flexible applications. It is proven that the proper oxygen partial pressure is important parameter to enhance the transparent conducting properties of IZTO films on PI substrate deposited at room temperature. - Highlights: • Indium zinc tin oxide (IZTO) films were deposited on polyimide at room temperature. • Transparent conducting properties of IZTO were influenced with oxygen partial pressure. • The smooth surface and high work function of IZTO were beneficial to anode layer. • The mechanical reliability of IZTO shows better performance to indium tin oxide film

Subcutaneous dirofilariosis (Dirofilaria repens: an infection spreading throughout the old world

Directory of Open Access Journals (Sweden)

Claudio Genchi

2017-11-01

Full Text Available Abstract Background Two main Dirofilaria species infect dogs: D. immitis and D. repens. While D. immitis has a worldwide distribution, D. repens is currently found only in Europe, Asia, and Africa. Adult D. repens are located in subcutaneous tissues of natural hosts where they survive for long periods of time. First-stage larvae, microfilariae, circulate in the peripheral bloodstream, where they are taken up by the mosquito intermediate hosts. Infected mosquitoes then transmit infective third-stage (L3 larvae to new hosts through the blood meal. In dogs, most infections are asymptomatic, although cutaneous disorders such as pruritus, dermal swelling, subcutaneous nodules, and ocular conjunctivitis can be observed. Currently, two factors have increased the concerns about this parasitic infection 1 its spread throughout the European countries and to other continents and its prevalence in dog populations, where in some cases it has overcome D. immitis; and 2 its zoonotic potential, which is much greater than that of D. immitis. Results Different hypotheses can be put forward to explain these concerns. First, climate change has allowed more favorable conditions for survival of culicid vectors. Second, accidental hosts such as humans may have a less efficient immune reaction against a parasite that is located in subcutaneous tissues, and thus less exposed to the host’s immune response than, for instance, D. immitis. Furthermore, the absence of clinical signs in the majority of canine infections and the difficulty in diagnosing the infection, due to the lack of serologic tests and thus the reliance on the identification of microfilariae and differentiation from D. immitis to confirm the presence of the parasite, favor the further spread of this species. Finally, among the macrocyclic lactones currently used to prevent heartworm infection, only moxidectin has been found to be fully effective against the infective larvae transmitted by mosquitoes and

A fibre-optic oxygen sensor for monitoring human breathing

International Nuclear Information System (INIS)

Chen, Rongsheng; Formenti, Federico; Hahn, Clive E W; Farmery, Andrew D; Obeid, Andy

2013-01-01

The development and construction of a tapered-tip fibre-optic fluorescence based oxygen sensor is described. The sensor is suitable for fast and real-time monitoring of human breathing. The sensitivity and response time of the oxygen sensor were evaluated in vitro with a gas pressure chamber system, where oxygen partial pressure was rapidly changed between 5 and 15 kPa, and then in vivo in five healthy adult participants who synchronized their breathing to a metronome set at 10, 20, 30, 40, 50, and 60 breaths min –1 . A Datex Ultima medical gas analyser was used to monitor breathing rate as a comparator. The sensor's response time in vitro was less than 150 ms, which allows accurate continuous measurement of inspired and expired oxygen pressure. Measurements of breathing rate by means of our oxygen sensor and of the Datex Ultima were in strong agreement. The results demonstrate that the device can reliably resolve breathing rates up to 60 breaths min –1 , and that it is a suitable cost-effective alternative for monitoring breathing rates and end-tidal oxygen partial pressure in the clinical setting. The rapid response time of the sensor may allow its use for monitoring rapid breathing rates as occur in children and the newborn. (note)

A CMOS self-powered front-end architecture for subcutaneous event-detector devices

CERN Document Server

Colomer-Farrarons, Jordi

2011-01-01

A CMOS Self-Powered Front-End Architecture for Subcutaneous Event-Detector Devices presents the conception and prototype realization of a Self-Powered architecture for subcutaneous detector devices. The architecture is designed to work as a true/false (event detector) or threshold level alarm of some substances, ions, etc. that are detected through a three-electrodes amperometric BioSensor approach. The device is conceived as a Low-Power subcutaneous implantable application powered by an inductive link, one emitter antenna at the external side of the skin and the receiver antenna under the ski

Composite Sr- and V-doped LaCrO3/YSZ sensor electrode operating at low oxygen levels

DEFF Research Database (Denmark)

Lund, Anders; Jacobsen, Torben; Hansen, Karin Vels

2012-01-01

A porous composite electrode of La0.8Sr0.2Cr0.97V0.03O3 -delta (LSCV) and yttria-stabilised zirconia (YSZ) was evaluated as a possible candidate for high-temperature potentiometric oxygen sensor measuring electrodes. The oxygen processes at the electrode were characterised by performing electroch....... The relatively low response time at 700º C at an oxygen partial pressure of around 5x10-6 bar and an inlet gas flow rate of 8 L h-1 makes the LSCV/YSZ electrode suitable for use as an potentiometric oxygen sensor electrodes.......A porous composite electrode of La0.8Sr0.2Cr0.97V0.03O3 -delta (LSCV) and yttria-stabilised zirconia (YSZ) was evaluated as a possible candidate for high-temperature potentiometric oxygen sensor measuring electrodes. The oxygen processes at the electrode were characterised by performing...... and 400 nm. At oxygen partial pressures around 0.2 bar at 700º C, the oxygen reaction is dominated by solid-state diffusion of oxide ions and surface reaction kinetics. At oxygen partial pressures around 10-5 bar above 800º C, gas phase mass transport processes dominate the impedance spectra...

Oxygenation level and hemoglobin concentration in experimental tumor estimated by diffuse optical spectroscopy

Science.gov (United States)

Orlova, A. G.; Kirillin, M. Yu.; Volovetsky, A. B.; Shilyagina, N. Yu.; Sergeeva, E. A.; Golubiatnikov, G. Yu.; Turchin, I. V.

2017-07-01

Using diffuse optical spectroscopy the level of oxygenation and hemoglobin concentration in experimental tumor in comparison with normal muscle tissue of mice have been studied. Subcutaneously growing SKBR-3 was used as a tumor model. Continuous wave fiber probe diffuse optical spectroscopy system was employed. Optical properties extraction approach was based on diffusion approximation. Decreased blood oxygen saturation level and increased total hemoglobin content were demonstrated in the neoplasm. The main reason of such differences between tumor and norm was significant elevation of deoxyhemoglobin concentration in SKBR-3. The method can be useful for diagnosis of tumors as well as for study of blood flow parameters of tumor models with different angiogenic properties.

Continuous subcutaneous infusion of opiates at end-of-life.

Science.gov (United States)

Anderson, Stacey L; Shreve, Scott T

2004-06-01

To review pertinent controlled trials using the continuous subcutaneous infusion of opioids (CSIO) at end-of-life and offer insight to pharmacists and clinicians into the appropriate use of this route of administration. A MEDLINE search for information regarding the subcutaneous administration of opioids in terminally ill patients (1975-December 2002) was conducted using the key words subcutaneous, narcotics, morphine, hydromorphone, fentanyl, pain, hospices, and palliative care. Additional references were located through review of bibliographies of the articles cited. Case reports and postsurgical studies were excluded. Searches were limited to English-language studies using humans. Experimental and observational studies were evaluated, using prospective trials as the evidence base for conclusions and including pertinent retrospective trials as they relate to the subcutaneous infusion of opioids at end-of-life. CSIO is effective and safe for use in terminal illness. Appropriate situations for consideration of CSIO are when difficulties arise in using the oral route, standard oral opiate therapy has failed adequate trials, the patient has limited intravenous access, adequate supervision of the CSIO is present, and CSIO will not unduly limit the functional activity of the patient. CSIO has a proven role in the management of pain at end-of-life. CSIO should not be considered the first route for administration of opiates, but does offer distinct advantages in the appropriate setting. CSIO continues to be a choice for end-of-life patients and is gradually becoming a standard practice in palliative medicine.

Optimal oxygen saturation in premature infants

Directory of Open Access Journals (Sweden)

Meayoung Chang

2011-09-01

Full Text Available There is a delicate balance between too little and too much supplemental oxygen exposure in premature infants. Since underuse and overuse of supplemental oxygen can harm premature infants, oxygen saturation levels must be monitored and kept at less than 95% to prevent reactive oxygen species-related diseases, such as retinopathy of prematurity and bronchopulmonary dysplasia. At the same time, desaturation below 80 to 85% must be avoided to prevent adverse consequences, such as cerebral palsy. It is still unclear what range of oxygen saturation is appropriate for premature infants; however, until the results of further studies are available, a reasonable target for pulse oxygen saturation (SpO2 is 90 to 93% with an intermittent review of the correlation between SpO2 and the partial pressure of arterial oxygen tension (PaO2. Because optimal oxygenation depends on individuals at the bedside making ongoing adjustments, each unit must define an optimal target range and set alarm limits according to their own equipment or conditions. All staff must be aware of these values and adjust the concentration of supplemental oxygen frequently.

Influence of circulating epinephrine on absorption of subcutaneously injected insulin

International Nuclear Information System (INIS)

Fernqvist, E.; Gunnarsson, R.; Linde, B.

1988-01-01

Effects of epinephrine (Epi) infusion on the absorption of subcutaneously injected 125I-labeled soluble human insulin (10 U) from the thigh or the abdomen were studied in 16 healthy subjects and from the thigh in 10 insulin-dependent diabetic (IDDM) patients. Epi was infused at 0.3 (high dose) or 0.1 (low dose; healthy subjects) nmol.kg-1.min-1 i.v., resulting in arterial plasma Epi levels of approximately 6 and 2 nM, respectively. Saline was infused on a control day. Insulin absorption was measured as disappearance of radioactivity from the injection site and as appearance of plasma immunoreactive insulin (IRI). Adipose tissue blood flow was measured with the 133Xe clearance technique. First-order disappearance rate constants of 125I from the thigh depot decreased approximately 40-50% during the high dose of Epi compared with control (P less than .001). The corresponding decrease from the abdominal depot was approximately 40% (P less than .001), whereas no significant change was found during the low Epi dose. IRI fell compared with control in all groups at the high Epi dose. The Epi-induced depression of insulin absorption occurred despite unaltered or even slightly increased subcutaneous blood flow. The results indicate that circulating Epi at levels seen during moderate physical stress depresses the absorption of soluble insulin from subcutaneous injection sites to an extent that might be important for glycemic control in IDDM patients. Furthermore, dissociation is found between changes in insulin absorption and subcutaneous blood flow during Epi infusion, suggesting that factors other than blood flow may also influence the absorption of subcutaneously injected insulin

In patients with extensive subcutaneous emphysema, which technique achieves maximal clinical resolution: infraclavicular incisions, subcutaneous drain insertion or suction on in situ chest drain?

Science.gov (United States)

Johnson, Charles H N; Lang, Sommer A; Bilal, Haris; Rammohan, Kandadai S

2014-06-01

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: 'In patients with extensive subcutaneous emphysema, which technique achieves maximal clinical resolution: infraclavicular incisions, subcutaneous drain insertion or suction on in situ chest drain?'. Altogether more than 200 papers were found using the reported search, of which 14 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Subcutaneous emphysema is usually a benign, self-limiting condition only requiring conservative management. Interventions are useful in the context of severe patient discomfort, respiratory distress or persistent air leak. In the absence of any comparative study, it is not possible to choose definitively between infraclavicular incisions, drain insertion and increasing suction on an in situ drain as the best method for managing severe subcutaneous emphysema. All the three techniques described have been shown to provide effective relief. Increasing suction on a chest tube already in situ provided rapid relief in patients developing SE following pulmonary resection. A retrospective study showed resolution in 66%, increasing to 98% in those who underwent video-assisted thoracic surgery with identification and closure of the leak. Insertion of a drain into the subcutaneous tissue also provided rapid sustained relief. Several studies aided drainage by using regular compressive massage. Infraclavicular incisions were also shown to provide rapid relief, but were noted to be more invasive and carried the potential for cosmetic defect. No major complications were illustrated. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Oxygen Toxicity and Special Operations Forces Diving: Hidden and Dangerous

NARCIS (Netherlands)

Wingelaar, Thijs T.; van Ooij, Pieter-Jan A. M.; van Hulst, Rob A.

2017-01-01

In Special Operations Forces (SOF) closed-circuit rebreathers with 100% oxygen are commonly utilized for covert diving operations. Exposure to high partial pressures of oxygen (PO2) could cause damage to the central nervous system (CNS) and pulmonary system. Longer exposure time and higher PO2 leads

Effect of oxygen at low and high light intensities on the growth of Neochloris oleoabundans

NARCIS (Netherlands)

Sousa, C.A.; Compadre, A.; Vermuë, M.H.; Wijffels, R.H.

2013-01-01

The effect of partial oxygen pressure on growth of Neochloris oleoabundans was studied at near-saturating light intensity in a fully-controlled photobioreactor. At the partial oxygen pressures tested (PO2=0.24; 0.42; 0.63; 0.84 bar), the specific growth rate was 1.36; 1.16; 0.93 and 0.68 day-1,

Temperature of cutaneous and subcutaneous tissue during the application of aerosols in rats

OpenAIRE

Andre de Oliveira Teixeira; Cassio Noronha Martins; Antônio Marcos Vargas da Silva; Alexandro Marques Tozetti; Rodrigo Della Méa Plentz; Luis Ulisses Signori

2014-01-01

This study compared the thermal changes of cutaneous and subcutaneous tissues exposed to different aerosols. Thirty-six adults Wistar rats were arranged in two treatment groups, one exposed to methyl salicylate (GSM; n = 9 skin and n = 9 subcutaneous) and the other exposed to diclofenac diethylammonium (GDD; n = 9 skin and n = 9 subcutaneous) aerosols. Five jets were applied for one-second through an apparatus to reduce spray dispersion (3 cmdiameter) in the lateral left thigh of the animals....

Photoacoustic Imaging in Oxygen Detection

Directory of Open Access Journals (Sweden)

Fei Cao

2017-12-01

Full Text Available Oxygen level, including blood oxygen saturation (sO2 and tissue oxygen partial pressure (pO2, are crucial physiological parameters in life science. This paper reviews the importance of these two parameters and the detection methods for them, focusing on the application of photoacoustic imaging in this scenario. sO2 is traditionally detected with optical spectra-based methods, and has recently been proven uniquely efficient by using photoacoustic methods. pO2, on the other hand, is typically detected by PET, MRI, or pure optical approaches, yet with limited spatial resolution, imaging frame rate, or penetration depth. Great potential has also been demonstrated by employing photoacoustic imaging to overcome the existing limitations of the aforementioned techniques.

Oxygen tension measurements of tumors growing in mice

International Nuclear Information System (INIS)

Adam, Markus F.; Dorie, Mary Jo; Brown, J. Martin

1999-01-01

Purpose: Clinical studies using the Eppendorf histograph have shown that patients whose tumors have a low pO 2 have worse local control after radiotherapy, and have higher metastatic rates. Because preclinical studies of methods of overcoming, or exploiting, hypoxia generally use transplanted tumors in mice, we have compared the oxygenation of mouse tumors with human tumors to determine the appropriateness of the transplanted mouse model for such preclinical studies. Methods and Materials: We evaluated the oxygenation status of subcutaneous (s.c.) tissue and of 12 intradermally (i.d.)- and 7 s.c.-growing mouse or human transplanted tumors in mice using the Eppendorf histograph, and compared the values obtained with measurements of human head and neck nodes. Results: The normal tissue pO 2 profile of air-breathing mice showed a nearly Gaussian distribution (38.2 ± 14.9 mmHg). Breathing 10% O 2 or carbogen resulted in dramatic changes in normal tissue oxygenation. Tumors growing intradermally in the back of air-breathing mice were extremely hypoxic and resistant to expected changes in oxygenation (carbogen breathing, size, and use of anesthetics). Tumors growing s.c. in the foot showed higher oxygen profiles with marked changes in oxygenation when exposing the animals to different levels of oxygen. However, the oxygenation of the mouse tumors transplanted in either site was only a fraction of that of the majority of human tumors. Conclusion: Experimental mouse tumors are markedly hypoxic, with median values of 10-20% of those of human tumors. Hence, mouse tumors are probably good models for the most hypoxic human tumors that respond poorly to radiotherapy; however, caution has to be exercised in extrapolating data from mouse to man

Subcutaneous metastasis from endometrial cancer; case report and literature review

OpenAIRE

Nicolae Bacalbasa; Irina Balescu; Alexandru Filipescu

2018-01-01

Subcutaneous metastases from endometrial cancer are rare situations, only few cases being described so far. The main incriminated mechanisms leading to the apparition of such lesions include hematogenous and lymphatic spread. We present the case of a 66-year-old patient known with previous history of stage IIIA endometroid endometrial carcinoma initially treated by surgery and adjuvant chemotherapy who developed at 18 months follow-up a distant subcutaneous oligometastasis. At this time the p...

Elephantine but not elephantiasis: Subcutaneous zygomycosis.

Science.gov (United States)

Girish, Meenakshi; Arora, Amit; Bhalla, Lucky; Salodkar, Atul

2011-09-01

Subcutaneous zygomycosis is an unusual disorder caused by a rare fungus, Basidiobolus ranarum. We report this entity in a 4- yr- old boy. Biopsy showed the Splendore Hoeppli phenomenon and the culture yielded Basidiobolus ranarum. The child responded to saturated solution of potassium iodide within 1 month of starting treatment.

The Effects of Synthetic Cannabinoids on Alveolar-Arterial Oxygen Gradient

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Egemen Kucuk

2016-09-01

Full Text Available Aim: Synthetic cannabinoids are chemicals that produce several marijuana-like effects in humans. Aim of this study is to investigate the effects of synthetic cannabinoids on to alveolar-arterial oxygen gradient. Material and Method: A total of 112 patients, who admitted directly to emergency clinic with synthetic cannabinoid usage, were determined between February 2014 and August 2014. Blood gases of 41 patients were determined as arterial blood gases on room air, and included in to study. Patients were evaluated according to age, sex, decade, partial pressure of arterial oxygen, partial pressure of arterial carbon dioxide, pH, bicarbonate, metabolic status, age consistent expected alveolar-arterial oxygen gradient and calculated alveolar-arterial oxygen gradient. Results: Synthetic cannabinoid using was higher in males, mean age of patients was 23.32±6.14 years. Number of patients in the third decade were significantly higher than the other decades. The calculated alveolar-arterial oxygen gradient value of patients was significantly higher than age consistent expected alveolar-arterial oxygen gradient value. Respiratory acidosis, was significantly higher than the other types of the metabolic disorders. The best cutoff point for calculated alveolar-arterial oxygen gradient was 12.70, with sensitivity of 90% and specifity of 85%. Area under curve was 0.70 for calculated alveolar-arterial oxygen gradient. Discussion: The value of alveolar-arterial oxygen gradient has been increased due to synthetic cannabinoid usage. This can be used as a supportive parameter in the diagnosis of synthetic cannabinoid usage.

Diffuse-type giant cell tumor of the subcutaneous thigh

International Nuclear Information System (INIS)

Sanghvi, D.A.; Purandare, N.C.; Jambhekar, N.A.; Agarwal, A.; Agarwal, M.G.

2007-01-01

Diffuse-type giant cell tumor is an extra-articular form of pigmented villonodular synovitis. The localized form of this lesion (tenosynovial giant cell tumor) is frequent, representing the most common subset arising from the synovium of a joint, bursa or tendon sheath, with 85% of cases occurring in the fingers. The less frequent diffuse-type giant cell tumors are commonly located in the periarticular soft tissues, but on rare occasions these lesions can be purely intramuscular or subcutaneous We report the case of a 26-year-old female with diffuse-type giant cell tumor of the subcutaneous thigh, remote from a joint, bursa or tendon sheath. A review of the literature did not reveal any similar description of a diffuse-type giant cell tumor completely within the subcutaneous thigh, remote from a joint, bursa or tendon sheath. These lesions were initially regarded as inflammatory or reactive processes, but since the identification of clonal abnormalities in these patients, and in view of their capacity for autonomous growth, they are now widely considered to represent benign neoplasms. (orig.)

Spatially monitoring oxygen level in 3D microfabricated cell culture systems using optical oxygen sensing beads.

Science.gov (United States)

Wang, Lin; Acosta, Miguel A; Leach, Jennie B; Carrier, Rebecca L

2013-04-21

Capability of measuring and monitoring local oxygen concentration at the single cell level (tens of microns scale) is often desirable but difficult to achieve in cell culture. In this study, biocompatible oxygen sensing beads were prepared and tested for their potential for real-time monitoring and mapping of local oxygen concentration in 3D micro-patterned cell culture systems. Each oxygen sensing bead is composed of a silica core loaded with both an oxygen sensitive Ru(Ph2phen3)Cl2 dye and oxygen insensitive Nile blue reference dye, and a poly-dimethylsiloxane (PDMS) shell rendering biocompatibility. Human intestinal epithelial Caco-2 cells were cultivated on a series of PDMS and type I collagen based substrates patterned with micro-well arrays for 3 or 7 days, and then brought into contact with oxygen sensing beads. Using an image analysis algorithm to convert florescence intensity of beads to partial oxygen pressure in the culture system, tens of microns-size oxygen sensing beads enabled the spatial measurement of local oxygen concentration in the microfabricated system. Results generally indicated lower oxygen level inside wells than on top of wells, and local oxygen level dependence on structural features of cell culture surfaces. Interestingly, chemical composition of cell culture substrates also appeared to affect oxygen level, with type-I collagen based cell culture systems having lower oxygen concentration compared to PDMS based cell culture systems. In general, results suggest that oxygen sensing beads can be utilized to achieve real-time and local monitoring of micro-environment oxygen level in 3D microfabricated cell culture systems.

Quadratic function between arterial partial oxygen pressure and mortality risk in sepsis patients: an interaction with simplified acute physiology score.

Science.gov (United States)

Zhang, Zhongheng; Ji, Xuqing

2016-10-13

Oxygen therapy is widely used in emergency and critical care settings, while there is little evidence on its real therapeutic effect. The study aimed to explore the impact of arterial oxygen partial pressure (PaO 2 ) on clinical outcomes in patients with sepsis. A large clinical database was employed for the study. Subjects meeting the diagnostic criteria of sepsis were eligible for the study. All measurements of PaO 2 were extracted. The primary endpoint was death from any causes during hospital stay. Survey data analysis was performed by using individual ICU admission as the primary sampling unit. Quadratic function was assumed for PaO 2 and its interaction with other covariates were explored. A total of 199,125 PaO 2 samples were identified for 11,002 ICU admissions. Each ICU stay comprised 18 PaO 2 samples in average. The fitted multivariable model supported our hypothesis that the effect of PaO 2 on mortality risk was in quadratic form. There was significant interaction between PaO 2 and SAPS-I (p = 0.007). Furthermore, the main effect of PaO 2 on SOFA score was nonlinear. The study shows that the effect of PaO 2 on mortality risk is in quadratic function form, and there is significant interaction between PaO 2 and severity of illness.

A woman with juxta-articular nodules—An uncommon form of subcutaneous granuloma annulare

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Lili Wang

2014-06-01

Full Text Available Granuloma annulare is a benign inflammatory dermatosis that is most common in children and young adults. The subcutaneous form of granuloma annulare, which occurs mainly on the extremities in children, is rare. Lesions usually occur as painless subcutaneous nodules without inflammation of the cutaneous surface; the most frequent sites are the legs, buttocks, and scalp. Nevertheless, we present a case of subcutaneous granuloma annulare confined to the dorsa of the hand joints and right knee in a 51-year-old woman.

Oxidation of ruthenium thin films using atomic oxygen

Energy Technology Data Exchange (ETDEWEB)

McCoy, A.P.; Bogan, J.; Brady, A.; Hughes, G.

2015-12-31

In this study, the use of atomic oxygen to oxidise ruthenium thin films is assessed. Atomic layer deposited (ALD) ruthenium thin films (~ 3 nm) were exposed to varying amounts of atomic oxygen and the results were compared to the impact of exposures to molecular oxygen. X-ray photoelectron spectroscopy studies reveal substantial oxidation of metallic ruthenium films to RuO{sub 2} at exposures as low as ~ 10{sup 2} L at 575 K when atomic oxygen was used. Higher exposures of molecular oxygen resulted in no metal oxidation highlighting the benefits of using atomic oxygen to form RuO{sub 2}. Additionally, the partial oxidation of these ruthenium films occurred at temperatures as low as 293 K (room temperature) in an atomic oxygen environment. - Highlights: • X-ray photoelectron spectroscopy study of the oxidation of Ru thin films • Oxidation of Ru thin films using atomic oxygen • Comparison between atomic oxygen and molecular oxygen treatments on Ru thin films • Fully oxidised RuO{sub 2} thin films formed with low exposures to atomic oxygen.

miRNAs in Human Subcutaneous Adipose Tissue

DEFF Research Database (Denmark)

Kristensen, Malene M.; Davidsen, Peter K.; Vigelso, Andreas

2017-01-01

Objective Obesity is central in the development of insulin resistance. However, the underlying mechanisms still need elucidation. Dysregulated microRNAs (miRNAs; post-transcriptional regulators) in adipose tissue may present an important link. Methods The miRNA expression in subcutaneous adipose ...

[Using the subcutaneous approach for symptoms control in a health center].

Science.gov (United States)

Pascual López, L; Portaceli Armiñana, A; Ros Sáez, A

2001-01-01

To describe the use of the subcutaneous tract for symptoms control in patients those are in phase of palliative treatment of their illness. Observational study. Primary care. Patients seen in a health center, in phase of palliative treatment of their illness, that needed for symptoms control the subcutaneous administration of drugs. Most of the patients were in terminal phase (19), the fundamental cause (17 cases) that justified the use of the subcutaneous tract was the difficulty to take drugs by oral tract in the last days of life, attention on death throes. The infusion continuous through injector type travenol, at an infusion speed of 2 ml/h, it was the most common way of drug administration (19 patients). The drugs and initial average dose most used were: morphine 19 patients dose 100 mg/24 h, hyoscine butylbromide (Buscapina), 13 patients, 60 mg/24 h, haloperidol 12 patients, 4 mg/24 h. The patients death was the main cause that justified the retirement of the continuous infusion (17 people sick), happening in its own home. Symptoms control was good or very good in the most of patients (14). The experience on using the subcutaneous tract for symptoms control in our health center is positive, being the fundamental cause for its use symptoms control in the last days of the patients life. The continuous subcutaneous infusion should be used in primary attention, as an usual technique for the symptoms control in patients that are in phase of palliative treatment of their illness.

'Multi-associations': predisposed to misinterpretation of peripheral tissue oxygenation and circulation in neonates.

Science.gov (United States)

Pichler, Gerhard; Pocivalnik, Mirjam; Riedl, Regina; Pichler-Stachl, Elisabeth; Morris, Nicholas; Zotter, Heinz; Müller, Wilhelm; Urlesberger, Berndt

2011-08-01

Interpretation of peripheral circulation in ill neonates is crucial but difficult. The aim was to analyse parameters potentially influencing peripheral oxygenation and circulation. In a prospective observational cohort study in 116 cardio-circulatory stable neonates, peripheral muscle near-infrared spectroscopy (NIRS) with venous occlusion was performed. Tissue oxygenation index (TOI), mixed venous oxygenation (SvO(2)), fractional oxygen extraction (FOE), fractional tissue oxygen extraction (FTOE), haemoglobin flow (Hbflow), oxygen delivery (DO(2)), oxygen consumption (VO(2)), and vascular resistance (VR) were assessed. Correlation coefficients between NIRS parameters and demographic parameters (gestational age, birth weight, age, actual weight, diameter of calf, subcutaneous adipose tissue), monitoring parameters (heart rate, arterial oxygen saturation (SaO(2)), mean blood pressure (MAP), core/peripheral temperature, central/peripheral capillary refill time) and laboratory parameters (haemoglobin concentration (Hb-blood), pCO(2)) were calculated. All demographic parameters except for Hbflow and DO(2) correlated with NIRS parameters. Heart rate correlated with TOI, SvO(2), VO(2) and VR. SaO(2) correlated with FOE/FTOE. MAP correlated with Hbflow, DO(2), VO(2) and VR. Core temperature correlated with FTOE. Peripheral temperature correlated with all NIRS parameters except VO(2). Hb-blood correlated with FOE and VR. pCO(2) levels correlated with TOI and SvO(2). The presence of multiple interdependent factors associated with peripheral oxygenation and circulation highlights the difficulty in interpreting NIRS data. Nevertheless, these findings have to be taken into account when analysing peripheral oxygenation and circulation data.

Temperature of cutaneous and subcutaneous tissue during the application of aerosols in rats

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Andre de Oliveira Teixeira

2014-10-01

Full Text Available This study compared the thermal changes of cutaneous and subcutaneous tissues exposed to different aerosols. Thirty-six adults Wistar rats were arranged in two treatment groups, one exposed to methyl salicylate (GSM; n = 9 skin and n = 9 subcutaneous and the other exposed to diclofenac diethylammonium (GDD; n = 9 skin and n = 9 subcutaneous aerosols. Five jets were applied for one-second through an apparatus to reduce spray dispersion (3 cmdiameter in the lateral left thigh of the animals. Temperatures were measured every minute (min. during 30 min., with a digital thermometer. In the skin tissue the sensor was positioned manually, in the subcutaneous tissue it was surgically inserted through the rear face and positioned in the lateral thigh. The skin temperature has homogeneously reduced in both groups. In the subcutaneous tissue the GDD has induced hypothermia from the 2nd to 20th min., the lowest temperature was recorded on the 7th min. (-3.6 ± 0.2ºC in relation to basal. Lowering the temperature by GSM took place from the 1st to 21st min, and the lowest temperature occurred on the 1st min (-9.7 ± 0.5ºC in relation to basal. In the three initial minutes the GSM had temperatures 25, 10 and 5% lower than the GDD. Aerosols have induced hypothermia in the tissues, while the GSM has decreased faster and reached lower values of temperature shown in the subcutaneous tissue.

High negative pressure subcutaneous suction drain for managing debilitating subcutaneous emphysema secondary to tube thoracostomy for an iatrogenic post computed tomography guided transthoracic needle biopsy pneumothorax: Case report and review of literature

Directory of Open Access Journals (Sweden)

Zeeshan Ahmed

2016-01-01

Conclusion: Debilitating subcutaneous emphysema which causes distress, anxiety, palpebral closure, dyspnoea or dysphagia requires intervention. High negative pressure subcutaneous suction drain provides immediate and sustained relief in extensive and debilitating SE.

Hyperbaric oxygen therapy in periodontal diseases

Directory of Open Access Journals (Sweden)

Swapna A. Mahale

2013-01-01

Full Text Available Hyperbaric oxygen (HBO 2 has been successfully used in several medical fields. The therapeutic effect is related to elevated partial oxygen pressure in the tissues. The pressure itself enhances oxygen solubility in the tissue fluids. HBO 2 has shown to affect angiogenesis, bone metabolism and bone turnover. Studies have been conducted to analyze the effects of HBO 2 therapy on periodontal disease. HBO 2 increases local oxygen distribution, especially at the base of the periodontal pocket, which inhibits the growth of anaerobic bacteria and allows the ischemic tissues to receive an adequate intake of oxygen sufficient for a rapid recovery of cell metabolism. It is increasingly being accepted as a beneficial adjunct to diverse clinical conditions. Nonhealing ulcers, chronic wounds and refractory osteomyelitis are a few conditions for which HBO therapy (HBOT has been extensively tried out. The dental surgeons have found a good ally in HBOT in managing dental condition.

Fabrication of lead-free piezoelectric Li2CO3-added (Ba,Ca)(Ti,Sn)O3 ceramics under controlled low oxygen partial pressure and their properties

Science.gov (United States)

Noritake, Kouta; Sakamoto, Wataru; Yuitoo, Isamu; Takeuchi, Teruaki; Hayashi, Koichiro; Yogo, Toshinobu

2018-02-01

Reduction-resistant lead-free (Ba,Ca)(Ti,Sn)O3 piezoceramics with high piezoelectric constants were fabricated by optimizing the amount of Li2CO3 added. Oxygen partial pressure was controlled during the sintering of (Ba,Ca)(Ti,Sn)O3 ceramics in a reducing atmosphere using H2-CO2 gas. Enhanced grain growth and a high-polarization state after poling treatment were achieved by adding Li2CO3. Optimizing the amount of Li2CO3 added to (Ba0.95Ca0.05)(Ti0.95Sn0.05)O3 ceramics sintered under a low oxygen partial pressure resulted in improved piezoelectric properties while maintaining the high sintered density. The prepared Li2CO3-added ceramic samples had homogeneous microstructures with a uniform dispersion of each major constituent element. However, the residual Li content in the 3 mol % Li2CO3-added (Ba0.95Ca0.05)(Ti0.95Sn0.05)O3 ceramics after sintering was less than 0.3 mol %. Sintered bodies of this ceramic prepared in a CO2 (1.5%)-H2 (0.3%)/Ar reducing atmosphere (PO2 = 10-8 atm at 1350 °C), exhibited sufficient electrical resistivity and a piezoelectric constant (d 33) exceeding 500 pC/N. The piezoelectric properties of this nonreducible ceramic were comparable or superior to those of the same ceramic sintered in air.

Subcutaneous infusion in palliative care: a focus on the neria soft 90 infusion set.

Science.gov (United States)

Gabriel, Janice

2014-11-01

Subcutaneous administration of medications and/or fluids can play a crucial part in supporting patients at home and thereby avoiding the need for hospitalisation. It is an area of patient care that has received little attention compared with other types of parenteral therapies. However, it is an effective and safe route for continuous administration for individuals requiring palliative care. Technological advancements have led to improved subcutaneous infusion devices, such as fine-gauge cannulae with integral sharps protection, as well as integral hypoallergenic dressings. These design features not only help to increase patient comfort but also minimise the potential for needlestick injuries, as well as providing the health professional with one sterile package containing all of the components needed to establish subcutaneous infusion. However, technological developments alone are insufficient to improve patient outcomes. Knowledge of the individual patient, together with their diagnosis and intended treatment, will influence the choice of subcutaneous infusion device, with the overall aim of minimising the potential for complications and improving comfort. This paper provides an overview of subcutaneous infusion, including the importance of patient assessment and the education and training needs of health professionals, and then focuses on one specific subcutaneous infusion device: the neria soft 90 infusion set.

Subcutaneous emphysema of the upper extremity following penetrating blackthorn injury to the wrist.

LENUS (Irish Health Repository)

Tiong, W H C

2009-02-01

SUMMARY: Noninfective subcutaneous emphysema of the upper extremity, albeit rare, has to be borne in mind when treating patients with subcutaneous emphysema. The misdiagnosis of this condition as its serious infective counterpart often leads to unnecessary aggressive treatment. Noninfective subcutaneous emphysema often accompanies a patient who has no systemic symptoms of illness. Unfortunately, the distinction is not always easy especially when history of injury suggests involvement of an infective or reactive element. Penetrating blackthorn injury is common, especially in rural communities, and often occurs from farming or gardening activities. Blackthorn penetration can cause numerous tissue reactions once embedded under the skin and they are often contaminated with soil. Here we present, for the first time, a case where penetrating blackthorn injury to the wrist resulted in noninfective subcutaneous emphysema involving the whole upper limb and neck, and its subsequent management.

Homozygous LIPE mutation in siblings with multiple symmetric lipomatosis, partial lipodystrophy, and myopathy.

Science.gov (United States)

Zolotov, Sagit; Xing, Chao; Mahamid, Riad; Shalata, Adel; Sheikh-Ahmad, Mohammed; Garg, Abhimanyu

2017-01-01

Despite considerable progress in identifying causal genes for lipodystrophy syndromes, the molecular basis of some peculiar adipose tissue disorders remains obscure. In an Israeli-Arab pedigree with a novel autosomal recessive, multiple symmetric lipomatosis (MSL), partial lipodystrophy and myopathy, we conducted exome sequencing of two affected siblings to identify the disease-causing mutation. The 41-year-old female proband and her 36-year-old brother reported marked accumulation of subcutaneous fat in the face, neck, axillae, and trunk but loss of subcutaneous fat from the lower extremities and progressive distal symmetric myopathy during adulthood. They had increased serum creatine kinase levels, hypertriglyceridemia and low levels of high-density lipoprotein cholesterol. Exome sequencing identified a novel homozygous NC_000019.9:g.42906092C>A variant on chromosome 19, leading to a NM_005357.3:c.3103G>T nucleotide change in coding DNA and corresponding p.(Glu1035*) protein change in hormone sensitive lipase (LIPE) gene as the disease-causing variant. Sanger sequencing further confirmed the segregation of the mutation in the family. Hormone sensitive lipase is the predominant regulator of lipolysis from adipocytes, releasing free fatty acids from stored triglycerides. The homozygous null LIPE mutation could result in marked inhibition of lipolysis from some adipose tissue depots and thus may induce an extremely rare phenotype of MSL and partial lipodystrophy in adulthood associated with complications of insulin resistance, such as diabetes, hypertriglyceridemia and hepatic steatosis. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Subcutaneous mycoses in Peru: a systematic review and meta-analysis for the burden of disease.

Science.gov (United States)

Ramírez Soto, Max Carlos; Malaga, German

2017-10-01

There is a worrying lack of epidemiological data on the geographical distribution and burden of subcutaneous mycoses in Peru, hindering the implementation of surveillance and control programs. This study aimed to estimate the disease burden of subcutaneous mycoses in Peru and identify which fungal species were commonly associated with these mycoses. We performed a meta-analysis after a systematic review of the published literature in PubMed, LILACS, and SciELO to estimate the burden of subcutaneous mycoses in 25 regions in Peru. The disease burden was determined in terms of prevalence (number of cases per 100,000 inhabitants) and the number of reported cases per year per region. A total of 26 studies were eligible for inclusion. Results showed that sporotrichosis was the most common subcutaneous mycosis (99.7%), whereas lobomycosis, chromoblastomycosis, and subcutaneous phaeohyphomycosis were rare. Cases of eumycetoma and subcutaneous zygomycosis were not found. Of the 25 regions, the burden of sporotrichosis was estimated for four regions classified as endemic; in nine regions, only isolated cases were reported. The highest burden of sporotrichosis was in Apurimac (15 cases/100,000 inhabitants; 57 cases/year), followed by Cajamarca (3/100,000 inhabitants; 30/year), Cusco (0.5/100,000 inhabitants; 4/year), and La Libertad (0.2/100,000 inhabitants; 2/year). In two regions, the mycoses predominantly affected children. Sporotrichosis is the most common subcutaneous mycosis in Peru, with a high disease burden in Apurimac. Chromoblastomycosis, lobomycosis, and subcutaneous phaeohyphomycosis are rare mycoses in Peru. © 2017 The International Society of Dermatology.

Diet-induced weight loss decreases adipose tissue oxygen tension with parallel changes in adipose tissue phenotype and insulin sensitivity in overweight humans

NARCIS (Netherlands)

Vink, R.G.; Roumans, N.J.; Čajlaković, M.; Cleutjens, J.P.M.; Boekschoten, M.V.; Fazelzadeh, P.; Vogel, M.A.A.; Blaak, E.E.; Mariman, E.C.; Baak, van M.A.; Goossens, G.H.

2017-01-01

Background/objectives: Although adipose tissue (AT) hypoxia is present in rodent models of obesity, evidence for this in humans is limited. Here, we investigated the effects of diet-induced weight loss (WL) on abdominal subcutaneous AT oxygen tension (pO 2), AT blood flow (ATBF), AT capillary

Study of the ZrO2-FeO-Fe2O3 system by thermogravimetry in partial pressure of oxygen and temperatures up to 15000C

International Nuclear Information System (INIS)

Goldschmidt, R.H.; Kiminami, A.

1987-01-01

The dissociation of iron oxide in the ZrO 2 -FeO-Fe 2 O 3 system was investigated in function of the temperature and the constant partial pressure of oxygen by thermal gravimetric analysis. The equilibrium diagram was constructed where the equilibrium relation between the solid phase of zirconium oxide, hematite and magnetite in 1437 0 C and PO 2 = 0.21 atm/m, as well as the equilibrium relation between the solid phase of zirconium oxide and hematite in lower temperatures than 1437 0 C were determined [pt

combined with either subcutaneous or intravenous administration of ...

African Journals Online (AJOL)

the time of sponge withdrawal, PMSG was administered either subcutaneously or ... Only the season of treatment had an effect on the percentage ... gestogen and Pregnant Mare Serum Gonackttrophin. (PMSG). ... artificial insemination.

A novel, non-invasive diagnostic clinical procedure for the determination of an oxygenation status of chronic lower leg ulcers using peri-ulceral transcutaneous oxygen partial pressure measurements: results of its application in chronic venous insufficiency (CVI).

Science.gov (United States)

Barnikol, Wolfgang K R; Pötzschke, Harald

2012-01-01

The basis for the new procedure is the simultaneous transcutaneous measurement of the peri-ulceral oxygen partial pressure (tcPO(2)), using a minimum of 4 electrodes which are placed as close to the wound margin as possible, additionally, as a challenge the patient inhales pure oxygen for approximately 15 minutes. In order to evaluate the measurement data and to characterise the wounds, two new oxygen parameters were defined: (1) the oxygen characteristic (K-PO(2)), and (2) the oxygen inhomogeneity (I-PO(2)) of a chronic wound. The first of these is the arithmetic mean of the two lowest tcPO(2) measurement values, and the second is the variation coefficient of the four measurement values. Using the K-PO(2) parameter, a grading of wound hypoxia can be obtained. To begin with, the physiologically regulated (and still compensated) hypoxia with K-PO(2) values of between 35 and 40 mmHg is distinguished from the pathological decompensated hypoxia with K-PO(2) values of between 0 and 35 mmHg; the first of these still stimulates self-healing (within the limits of the oxygen balance). The decompensated hypoxia can be (arbitrarily) divided into "simple" hypoxia (Grade I), intense hypoxia (Grade II) and extreme hypoxia (Grade III), with the possibility of intermediate grades (I/II and II/III).Measurements were carried out using the new procedure on the skin of the right inner ankle of 21 healthy volunteers of various ages, and in 17 CVI (chronic venous insufficiency) wounds. Sixteen of the 17 CVI wounds (i.e., 94%) were found to be pathologically hypoxic, a state which was not found in any of the healthy volunteers. The oxygen inhomogeneity (I-PO(2)) of the individual chronic wounds increased exponentially as a function of the hypoxia grading (K-PO(2)), with a 10-fold increase with extreme hypoxia in contrast to a constant value of approximately 14% in the healthy volunteers. This pronounced oxygen inhomogeneity explains inhomogeneous wound healing, resulting in the so

The influence of norepinephrine and phenylephrine on cerebral perfusion and oxygenation during propofol-remifentanil and propofol-remifentanil-dexmedetomidine anaesthesia in piglets

DEFF Research Database (Denmark)

Mikkelsen, Mai Louise Grandsgaard; Ambrus, Rikard; Rasmussen, Rune

2018-01-01

of dexmedetomidine. Cerebral perfusion measured by laser speckle contrast imaging was related to cerebral oxygenation as measured by an intracerebral Licox probe (partial pressure of oxygen) and transcranial near infrared spectroscopy technology (NIRS) (cerebral oxygen saturation). Results During propofol......–remifentanil anaesthesia, increases in blood pressure by norepinephrine and phenylephrine did not change cerebral perfusion significantly, but cerebral partial pressure of oxygen (Licox) increased following vasopressors in both groups and increases following norepinephrine were significant (NBP: P = 0.04, LBP: P = 0......–remifentanil–dexmedetomidine anaesthesia was not followed by significant changes in cerebral perfusion. Licox measures increased significantly following both vasopressors in both groups, whereas the decreases in NIRS measures were only significant in the NBP group. Conclusions Cerebral partial pressure of oxygen measured by Licox...

MRI and US findings of subcutaneous fat necrosis of the newborn

Energy Technology Data Exchange (ETDEWEB)

Vasireddy, Syam; Long, Scott D. [Southern Illinois University, Department of Radiology, Springfield, IL (United States); St. John' s Hospital, Department of Radiology, Springfield, IL (United States); Sacheti, Bhavna [Medical College of Wisconsin, Department of Pediatric Critical Care, Milwaukee, WI (United States); Children' s Hospital Wisconsin, Department of Critical Care, Milwaukee, WI (United States); Mayforth, Ruth D. [Southern Illinois University, Department of Surgery, Springfield, IL (United States); St. John' s Hospital, Department of Surgery, Springfield, IL (United States)

2009-01-15

Subcutaneous fat necrosis of the newborn (SCFN) is an uncommon, benign disorder found in full-term or post-mature neonates. It usually presents in neonates who have experienced perinatal difficulty such as asphyxia, peripheral hypoxemia, hypothermia, meconium aspiration or trauma. We present a newborn with abnormal findings on MRI and US within the axilla, neck, and abdominal walls that were pathologically proved via biopsy to be subcutaneous fat necrosis. (orig.)

MRI of a Subcutaneous Myolipoma in the Ankle: a Case Report

Energy Technology Data Exchange (ETDEWEB)

Lee, Yeon Soo; Park, Sang Eun; Lee, Jung Uee; Choi, Eun Seok [Daejeon St. Mary' s Hospital, The Catholic University of Korea, Daejeon (Korea, Republic of)

2011-10-15

Myolipoma is a rare benign tumor, composed of irregularly admixed adipose tissue and smooth muscle fibers. Few literature studies have described the radiologic appearance of myolipoma, especially in the soft tissue. No MRI findings in subcutaneous myolipoma of an extremity have been reported. Here, we report on the case of a 34-year-old woman with myolipoma in the subcutaneous tissue of the ankle and describe MRI features of the lesion.

Contrast of artificial subcutaneous hematomas in MRI over time.

Science.gov (United States)

Hassler, Eva Maria; Ogris, Kathrin; Petrovic, Andreas; Neumayer, Bernhard; Widek, Thomas; Yen, Kathrin; Scheurer, Eva

2015-03-01

In clinical forensic medicine, hematomas and other externally visible injuries build the basis for the reconstruction of events. However, dating of subcutaneous hematomas based on their external aspect is difficult. Magnetic resonance imaging (MRI) has proven its use in dating intracranial hemorrhage. Thus, the aim was to investigate if MRI can also be used for dating subcutaneous hematomas and to analyze an eventual influence of the hematoma shape. In 20 healthy volunteers (11 females, 9 males, aged 26.9 ± 3.8 years), 4 ml of autologous blood were injected subcutaneously in the thigh. The hematoma was scanned immediately after the injection, after 3 and 24 h and 3, 7, and 14 days using three sequences with different contrast. Data was analyzed by measuring signal intensities of the hematoma, the muscle, and the subcutaneous tissue over time, and the Michelson contrast coefficients between the tissues were calculated. In the analysis, hematoma shape was considered. Signal intensity of blood in the proton density-weighted sequence reached its maximum 3 h after the injection with a subsequent decrease, whereas the signal intensities of muscle and fatty tissue remained constant. The time course of the Michelson coefficient of blood versus muscle decreased exponentially with a change from hyperintensity to hypointensity at 116.9 h, depending on hematoma shape. In the other sequences, either variability was large or contrast coefficients stayed constant over time. The observed change of contrast of blood versus muscle permits a quick estimate of a hematoma's age. The consideration of the hematoma shape is expected to further enhance dating using MRI.

Combined impact of water column oxygen and temperature on internal oxygen status and growth of Zostera marina seedlings and adult shoots

DEFF Research Database (Denmark)

Raun, Ane-Marie Løvendahl; Borum, Jens

2013-01-01

Eelgrass (Zostera marina L.) occasionally experiences severe die-offs during warm summer periods with variable water column oxygen partial pressures (pO). Eelgrass is known to be very intolerant to tissue anoxia with reduced growth and increasing mortality after ≤12h anoxia in the dark...... at temperatures of ≥25°C. In the present study we experimentally examine the impact of combined water column oxygen and temperature on oxygen dynamics in leaf meristems of seedlings and adult shoots to better understand how stressful environmental conditions affect eelgrass oxygen dynamics and subsequent growth...... and mortality. There was a strong interaction between water column oxygen and temperature on meristem pO implying that eelgrass is rather resistant to unfavorable oxygen conditions in winter but becomes increasingly vulnerable in summer, especially at high temperatures. At 25°C meristems became anoxic...

Improved arterial blood oxygenation following intravenous infusion of cold supersaturated dissolved oxygen solution.

Science.gov (United States)

Grady, Daniel J; Gentile, Michael A; Riggs, John H; Cheifetz, Ira M

2014-01-01

One of the primary goals of critical care medicine is to support adequate gas exchange without iatrogenic sequelae. An emerging method of delivering supplemental oxygen is intravenously rather than via the traditional inhalation route. The objective of this study was to evaluate the gas-exchange effects of infusing cold intravenous (IV) fluids containing very high partial pressures of dissolved oxygen (>760 mm Hg) in a porcine model. Juvenile swines were anesthetized and mechanically ventilated. Each animal received an infusion of cold (13 °C) Ringer's lactate solution (30 mL/kg/hour), which had been supersaturated with dissolved oxygen gas (39.7 mg/L dissolved oxygen, 992 mm Hg, 30.5 mL/L). Arterial blood gases and physiologic measurements were repeated at 15-minute intervals during a 60-minute IV infusion of the supersaturated dissolved oxygen solution. Each animal served as its own control. Five swines (12.9 ± 0.9 kg) were studied. Following the 60-minute infusion, there were significant increases in PaO2 and SaO2 (P < 0.05) and a significant decrease in PaCO2 (P < 0.05), with a corresponding normalization in arterial blood pH. Additionally, there was a significant decrease in core body temperature (P < 0.05) when compared to the baseline preinfusion state. A cold, supersaturated dissolved oxygen solution may be intravenously administered to improve arterial blood oxygenation and ventilation parameters and induce a mild therapeutic hypothermia in a porcine model.

Solubility of oxygen in a seawater medium in equilibrium with a high-pressure oxy-helium atmosphere.

Science.gov (United States)

Taylor, C D

1979-06-01

The molar oxygen concentration in a seawater medium in equilibrium with a high-pressure oxygen-helium atmosphere was measured directly in pressurized subsamples, using a modified version of the Winkler oxygen analysis. At a partial pressure of oxygen of 1 atm or less, its concentration in the aqueous phase was adequately described by Henry's Law at total pressures up to 600 atm. This phenomenon, which permits a straightforward determination of dissolved oxygen within hyperbaric systems, resulted from pressure-induced compensatory alterations in the Henry's Law variables rather than from a true obedience to the Ideal Gas Law. If the partial pressure of a gas contributes significantly to the hydrostatic pressure, Henry's Law is no longer adequate for determining its solubility within the compressed medium.

Partial achilles tendon rupture presenting with giant hematoma; MRI findings of 4 year follow up.

Science.gov (United States)

Sarsilmaz, Aysegul; Varer, Makbule; Coskun, Gulten; Apaydın, Melda; Oyar, Orhan

2011-12-01

In the young population, spontaneous rupture of Achilles tendon is very rare. The big hematoma is also rare finding of the Achilles tendon partial rupture. It is usually seen with complete rupture. We presented imaging findings of 4 years follow up of the spontaneous partial rupture of Achilles tendon presenting with giant expanding hematoma and mimicking complete rupture radiologically. We discussed the alterations of tendon signal intensity and result of conservative therapy after partial rupture with big hematoma in the long term. A 29 year-old man, applied with pain and swelling in the retrocalcaneal region of left ankle. He did not have chronic metabolic disease. He was not active in physical activities. X-ray radiograms were normal. At magnetic resonance images (MRI), there was an intratendinous big hematoma, subcutanous fat planes were edematous around tendon. The diagnosis was partial rupture and giant hematoma. Hematoma was drained. The conservative treatment was applied and his complaints disappeared. After treatment, approximately 4 years later, control MRI showed thickened and hypointense tendon in all images. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Heavy-ion induced secondary electron emission from Mg, Al, and Si partially covered with oxygen

International Nuclear Information System (INIS)

Weng, J; Veje, E.

1984-01-01

We have bombarded Mg, Al, and Si with 80 keV Ar + ions and measured the secondary electron emission yields at projectile incidence angles from 0 0 to 85 0 , with oxygen present at the target as well as under UHV conditions. The total secondary electron emission yields are found to depend fairly much on the amount of oxygen present. The three elements studied show relatively large individual variations. For all three elements, and with as well as without oxygen present, the relative secondary electron emission yield is observed to vary as 1/cos v, where v is the angle of incidence of the projectiles. This seems to indicate that the secondary electron production is initiated uniformly along the projectile path in the solid, in a region close to the surface. The results are discussed, and it is tentatively suggested, that the increase in secondary electron emission, caused by the presence of oxygen, originates from neutralization of sputtered oxygen, which initially is sitting as O 2- ions. (orig.)

Rf-sputtered vanadium oxide thin films: effect of oxygen partial pressure on structural and electrochemical properties

CERN Document Server

Park, Y J; Ryu, K S; Chang, S H; Park, S C; Yoon, S M; Kim, D K

2001-01-01

Vanadium oxide thin films with thickness of about 2000 A have been prepared by radio frequency sputter deposition using a V sub 2 O sub 5 target in a mixed argon and oxygen atmosphere with different Ar/O sub 2 ratio ranging from 99/1 to 90/10. X-ray diffraction and X-ray absorption near edge structure spectroscopic studies show that the oxygen content higher than 5% crystallizes a stoichiometric V sub O sub 5 phase, while oxygen deficient phase is formed in the lower oxygen content. The oxygen content in the mixed Ar + O sub 2 has a significant influence on electrochemical lithium insertion/deinsertion property. The discharge-charge capacity of vanadium oxide film increases with increasing the reactive oxygen content. The V sub O sub 5 film deposited at the Ar/O sub 2 ratio of 90/10 exhibits high discharge capacity of 100 mu Ah/cm sup 2 -mu m along with good cycle performance.

Subcutaneous emphysema during status astmaticus

International Nuclear Information System (INIS)

Schwarz, E.

1985-01-01

Spontaneous subcutaneous accumulations of air in the soft parts of the thorax during an asthmatic crisis (status asthmaticus) are rarely seen. The pathomechanism of the phenomenon, which may lead to the formation of an emphysema of the soft parts via the pneumomediastinum, is discussed, and the possible complications which must be taken into account are pointed out. The value of radiological examination of the thorax in children suffering from asthma bronchiale, is explained briefly. (orig.) [de

Oxygen diffusion in nanocrystalline yttria-stabilized zirconia: the effect of grain boundaries.

Science.gov (United States)

De Souza, Roger A; Pietrowski, Martha J; Anselmi-Tamburini, Umberto; Kim, Sangtae; Munir, Zuhair A; Martin, Manfred

2008-04-21

The transport of oxygen in dense samples of yttria-stabilized zirconia (YSZ), of average grain size d approximately 50 nm, has been studied by means of 18O/16O exchange annealing and secondary ion mass spectrometry (SIMS). Oxygen diffusion coefficients (D*) and oxygen surface exchange coefficients (k*) were measured for temperatures 673oxygen partial pressure of 900 mbar. No evidence is found for fast diffusion along grain boundaries. Rather, the analysis indicates that grain boundaries hinder oxygen transport.

Subcutaneous endoscopically assisted ligation using miniport for ...

African Journals Online (AJOL)

Background This report describes the first miniport method using subcutaneous endoscopically assisted ligation (SEAL) for the treatment of girls with inguinal hernia. To validate its safety and efficacy, the authors evaluated their early experiences. Methods Between April 2014 and December 2014, 19 SEALs using miniport ...

Anthropometrical Profile, Skinfold Tickness and Subcutaneous Fat ...

African Journals Online (AJOL)

Background: The threatening health problems resulting from excess subcutaneous fat depositions have been reported by the world Health Organization. Also noteworthy is that childhood obesity is a pointer to adult obesity. This necessitated a study on the anthropometrical profiles of adolescents of Southeast Nigeria using ...

Detection and volume estimation of artificial hematomas in the subcutaneous fatty tissue: comparison of different MR sequences at 3.0 T.

Science.gov (United States)

Ogris, Kathrin; Petrovic, Andreas; Scheicher, Sylvia; Sprenger, Hanna; Urschler, Martin; Hassler, Eva Maria; Yen, Kathrin; Scheurer, Eva

2017-06-01

In legal medicine, reliable localization and analysis of hematomas in subcutaneous fatty tissue is required for forensic reconstruction. Due to the absence of ionizing radiation, magnetic resonance imaging (MRI) is particularly suited to examining living persons with forensically relevant injuries. However, there is limited experience regarding MRI signal properties of hemorrhage in soft tissue. The aim of this study was to evaluate MR sequences with respect to their ability to show high contrast between hematomas and subcutaneous fatty tissue as well as to reliably determine the volume of artificial hematomas. Porcine tissue models were prepared by injecting blood into the subcutaneous fatty tissue to create artificial hematomas. MR images were acquired at 3T and four blinded observers conducted manual segmentation of the hematomas. To assess segmentability, the agreement of measured volume with the known volume of injected blood was statistically analyzed. A physically motivated normalization taking into account partial volume effect was applied to the data to ensure comparable results among differently sized hematomas. The inversion recovery sequence exhibited the best segmentability rate, whereas the T1T2w turbo spin echo sequence showed the most accurate results regarding volume estimation. Both sequences led to reproducible volume estimations. This study demonstrates that MRI is a promising forensic tool to assess and visualize even very small amounts of blood in soft tissue. The presented results enable the improvement of protocols for detection and volume determination of hemorrhage in forensically relevant cases and also provide fundamental knowledge for future in-vivo examinations.

About Error in Measuring Oxygen Concentration by Solid-Electrolyte Sensors

Directory of Open Access Journals (Sweden)

V. I. Nazarov

2008-01-01

Full Text Available The paper evaluates additional errors while measuring oxygen concentration in a gas mixture by a solid-electrolyte cell. Experimental dependences of additional errors caused by changes in temperature in a sensor zone, discharge of gas mixture supplied to a sensor zone, partial pressure in the gas mixture and fluctuations in oxygen concentrations in the air.

Phase stability and oxygen diffusion in RBa2Cu3O6+x (R=Y, Nd)

International Nuclear Information System (INIS)

Mozhaev, A.P.; Mazo, G.N.; Galkin, A.A.; Khromova, N.V.

1996-01-01

Phase stability boundaries of RBa 2 Cu 3 O 6 + x (R=Y, Nd) compounds for oxygen partial pressure wide range were determined by means of Coulomb titration. Phase decomposition is shown to occur without formation of liquid phase. Principial differences in the chemical composition of decomposition product of Y- and Nd-containing phases were detected. Dependences of oxygen non-stoichiometry of the compounds on temperature were determined. Fragments of P o 2 -T-x-diagrams were plotted. Oxygen diffusion coefficients within wide range of temperatures and partial pressures of oxygen were determined. Dependence of diffusion parameters on oxygen non-stoichiometry and P o 2 was determined. Oxygen diffusion was determined to occur more rapidly in orthorhombic phase than in tetragonal one. Diffusion coefficients were shown to increase at transition from Y-to Nd-containing phase. 13 refs., 6 figs., 2 tabs

Injection Technique and Pen Needle Design Affect Leakage From Skin After Subcutaneous Injections

DEFF Research Database (Denmark)

Præstmark, Kezia Ann; Stallknecht, Bente; Jensen, Morten Lind

2016-01-01

BACKGROUND: After a subcutaneous injection fluid might leak out of the skin, commonly referred to as leakage or backflow. The objective was to examine the influence of needle design and injection technique on leakage after injections in the subcutaneous tissue of humans and pigs. METHOD: Leakage ...

An oxygen pressure sensor using surface acoustic wave devices

Science.gov (United States)

Leighty, Bradley D.; Upchurch, Billy T.; Oglesby, Donald M.

1993-01-01

Surface acoustic wave (SAW) piezoelectric devices are finding widespread applications in many arenas, particularly in the area of chemical sensing. We have developed an oxygen pressure sensor based on coating a SAW device with an oxygen binding agent which can be tailored to provide variable sensitivity. The coating is prepared by dissolving an oxygen binding agent in a toluene solution of a copolymer which is then sprayed onto the surface of the SAW device. Experimental data shows the feasibility of tailoring sensors to measure the partial pressure of oxygen from 2.6 to 67 KPa (20 to 500 torr). Potential applications of this technology are discussed.

Oxygen ordering in Nb(1 1 0) films

International Nuclear Information System (INIS)

Hellwig, O.; Zabel, H.

2003-01-01

Synchrotron X-ray diffraction (XRD) during the atmospheric oxidation of epitaxial Nb(1 1 0) films at elevated temperature reveals the formation of highly ordered oxygen phases within the Nb lattice. The oxygen is stored on interstitial lattice sites without destroying the basic BCC structure of the Nb host lattice. However the lattice exhibits an out-of-plane lattice expansion of up to 4.3%. During oxidation we observe the formation of a non-ordered lattice gas phase succeeded by a well-defined sequence of oxygen superstructures until finally the whole film is consumed by the formation of amorphous Nb 2 O 5 . We show that XRD is an excellent tool to monitor the exact evolution of the different oxygen phases. In addition we demonstrate that UHV post-annealing of partially oxidized films can be used to rearrange the oxygen within the sample while keeping the overall amount of oxygen constant

Extended analysis of AL-amyloid protein from abdominal wall subcutaneous fat biopsy

DEFF Research Database (Denmark)

Olsen, K E; Sletten, K; Westermark, Per

1998-01-01

a subcutaneous fat tissue biopsy and submitted to extended protein separation, typing and amino acid sequence analyses. The AL-protein belonged to the rare immunoglobulin light chain kappa, subtype kappa IV and contained unique amino acid substitutions, mostly in the highly preserved framework regions. The study...... shows that subcutaneous fat biopsies are useful sources of amyloid material for biochemical studies....

Pilot study assessment of dynamic vascular changes in breast cancer with near-infrared tomography from prospectively targeted manipulations of inspired end-tidal partial pressure of oxygen and carbon dioxide.

Science.gov (United States)

Jiang, Shudong; Pogue, Brian W; Michaelsen, Kelly E; Jermyn, Michael; Mastanduno, Michael A; Frazee, Tracy E; Kaufman, Peter A; Paulsen, Keith D

2013-07-01

The dynamic vascular changes in the breast resulting from manipulation of both inspired end-tidal partial pressure of oxygen and carbon dioxide were imaged using a 30 s per frame frequency-domain near-infrared spectral (NIRS) tomography system. By analyzing the images from five subjects with asymptomatic mammography under different inspired gas stimulation sequences, the mixture that maximized tissue vascular and oxygenation changes was established. These results indicate maximum changes in deoxy-hemoglobin, oxygen saturation, and total hemoglobin of 21, 9, and 3%, respectively. Using this inspired gas manipulation sequence, an individual case study of a subject with locally advanced breast cancer undergoing neoadjuvant chemotherapy (NAC) was analyzed. Dynamic NIRS imaging was performed at different time points during treatment. The maximum tumor dynamic changes in deoxy-hemoglobin increased from less than 7% at cycle 1, day 5 (C1, D5) to 17% at (C1, D28), which indicated a complete response to NAC early during treatment and was subsequently confirmed pathologically at the time of surgery.

Peripheral subcutaneous vulvar stimulation in the management of severe and refractory vulvodynia.

Science.gov (United States)

De Andres, Jose; Sanchis-Lopez, Nerea; Asensio-Samper, Juan Marcos; Fabregat-Cid, Gustavo; Dolz, Vicente Molsalve

2013-02-01

Vulvodynia is a complex and multifactorial clinical condition with severe pain that occurs in the absence of visible infectious, inflammatory, neoplastic, or neurological findings. A 35-year-old woman with 3 years of dysesthetic vulvodynia tried conventional and interventional medical treatment with inadequate relief. She was offered peripheral subcutaneous vulvar field stimulation and underwent implantation of two vulvar subcutaneous electrodes. At 15 days after treatment and during 1-year follow-up, the patient scored 1 out of 15 on Friedrich scale, 1 out of 10 on the visual analog scale, and 1 out of 10 on the tampon test. The patient no longer requires oral medication. Stimulation with subcutaneous electrodes provided relief from vulvodynia to a patient in whom all previous therapeutic approaches had failed.

The influence of target oxygen on the YBa2Cu3O6+δ DC Magnetron sputtering process

International Nuclear Information System (INIS)

Larsson, G.; Selinder, T.I.; Helmersson, U

1990-01-01

The oxygen partial pressure and the target potential have been monitored under a range of process conditions during single target dc magnetron sputtering of Y-Ba-Cu-O. The introduced sputtering gas consisted in all but one instance of pure argon and hence the oxygen present in the plasma originated mainly from the target. During the first hours of sputtering the oxygen partial pressure was of the same magnitude as the argon pressure (3.0 Pa). As the oxygen was released from the target and subsequently removed by pumping, the target potential increased and the film composition became more stoichiometric. After 30-40 hours of sputtering the target potential and the oxygen pressure stabilized and the film composition was equal to that of the stoichiometric target. If an oxygen flow exceeding a critical level was mixed into the sputtering gas the target potential and the deposition rate decreased swiftly. This was due to target oxidation, further manifested in changing plasma and target colours. In some instances the stabilization after 'presputtering' was incomplete and oscillations in target voltage and oxygen partial pressure were observed. The fluctuations made it virtually impossible to obtain stoichiometric films. The oscillative behaviour of the sputtering process is tentatively explained by a target temperature dependent oxygen diffusion. (au)

Large arteriolar component of oxygen delivery implies a safe margin of oxygen supply to cerebral tissue.

Science.gov (United States)

Sakadžić, Sava; Mandeville, Emiri T; Gagnon, Louis; Musacchia, Joseph J; Yaseen, Mohammad A; Yucel, Meryem A; Lefebvre, Joel; Lesage, Frédéric; Dale, Anders M; Eikermann-Haerter, Katharina; Ayata, Cenk; Srinivasan, Vivek J; Lo, Eng H; Devor, Anna; Boas, David A

2014-12-08

What is the organization of cerebral microvascular oxygenation and morphology that allows adequate tissue oxygenation at different activity levels? We address this question in the mouse cerebral cortex using microscopic imaging of intravascular O2 partial pressure and blood flow combined with numerical modelling. Here we show that parenchymal arterioles are responsible for 50% of the extracted O2 at baseline activity, and the majority of the remaining O2 exchange takes place within the first few capillary branches. Most capillaries release little O2 at baseline acting as an O2 reserve that is recruited during increased neuronal activity or decreased blood flow. Our results challenge the common perception that capillaries are the major site of O2 delivery to cerebral tissue. The understanding of oxygenation distribution along arterio-capillary paths may have profound implications for the interpretation of blood-oxygen-level dependent (BOLD) contrast in functional magnetic resonance imaging and for evaluating microvascular O2 delivery capacity to support cerebral tissue in disease.

Carbon Dioxide Fluctuations Are Associated with Changes in Cerebral Oxygenation and Electrical Activity in Infants Born Preterm.

Science.gov (United States)

Dix, Laura Marie Louise; Weeke, Lauren Carleen; de Vries, Linda Simone; Groenendaal, Floris; Baerts, Willem; van Bel, Frank; Lemmers, Petra Maria Anna

2017-08-01

To evaluate the effects of acute arterial carbon dioxide partial pressure changes on cerebral oxygenation and electrical activity in infants born preterm. This retrospective observational study included ventilated infants born preterm with acute fluctuations of continuous end-tidal CO 2 (etCO 2 ) as a surrogate marker for arterial carbon dioxide partial pressure, during the first 72 hours of life. Regional cerebral oxygen saturation and fractional tissue oxygen extraction were monitored with near-infrared spectroscopy. Brain activity was monitored with 2-channel electroencephalography. Spontaneous activity transients (SATs) rate (SATs/minute) and interval between SATs (in seconds) were calculated. Ten-minute periods were selected for analysis: before, during, and after etCO 2 fluctuations of ≥5  mm Hg. Thirty-eight patients (mean ± SD gestational age of 29 ± 1.8 weeks) were included, with 60 episodes of etCO 2 increase and 70 episodes of etCO 2 decrease. During etCO 2 increases, brain oxygenation increased (regional cerebral oxygen saturation increased, fractional tissue oxygen extraction decreased; P carbon dioxide partial pressure that may be harmful to the neonatal brain. Copyright © 2017 Elsevier Inc. All rights reserved.

Development and Validation of Noninvasive Magnetic Resonance Relaxometry for the In Vivo Assessment of Tissue-Engineered Graft Oxygenation.

Science.gov (United States)

Einstein, Samuel A; Weegman, Bradley P; Firpo, Meri T; Papas, Klearchos K; Garwood, Michael

2016-11-01

Techniques to monitor the oxygen partial pressure (pO 2 ) within implanted tissue-engineered grafts (TEGs) are critically necessary for TEG development, but current methods are invasive and inaccurate. In this study, we developed an accurate and noninvasive technique to monitor TEG pO 2 utilizing proton ( 1 H) or fluorine ( 19 F) magnetic resonance spectroscopy (MRS) relaxometry. The value of the spin-lattice relaxation rate constant (R 1 ) of some biocompatible compounds is sensitive to dissolved oxygen (and temperature), while insensitive to other external factors. Through this physical mechanism, MRS can measure the pO 2 of implanted TEGs. We evaluated six potential MRS pO 2 probes and measured their oxygen and temperature sensitivities and their intrinsic R 1 values at 16.4 T. Acellular TEGs were constructed by emulsifying porcine plasma with perfluoro-15-crown-5-ether, injecting the emulsion into a macroencapsulation device, and cross-linking the plasma with a thrombin solution. A multiparametric calibration equation containing R 1 , pO 2 , and temperature was empirically generated from MRS data and validated with fiber optic (FO) probes in vitro. TEGs were then implanted in a dorsal subcutaneous pocket in a murine model and evaluated with MRS up to 29 days postimplantation. R 1 measurements from the TEGs were converted to pO 2 values using the established calibration equation and these in vivo pO 2 measurements were simultaneously validated with FO probes. Additionally, MRS was used to detect increased pO 2 within implanted TEGs that received supplemental oxygen delivery. Finally, based on a comparison of our MRS data with previously reported data, ultra-high-field (16.4 T) is shown to have an advantage for measuring hypoxia with 19 F MRS. Results from this study show MRS relaxometry to be a precise, accurate, and noninvasive technique to monitor TEG pO 2 in vitro and in vivo.

Treatment of frozen shoulder with subcutaneous TNF-alpha blockade compared with local glucocorticoid injection

DEFF Research Database (Denmark)

Schydlowsky, Pierre; Szkudlarek, Marcin; Madsen, Ole Rintek

2012-01-01

We compared the effect of subcutaneous adalimumab injections with intraarticular glucocorticoid injections on frozen shoulder of 18 patients with unilateral joint involvement. Ten patients were randomised to subcutaneous injections with adalimumab and eight to intraarticular glucocorticoid inject...

Intramuscular versus Subcutaneous Administration of Iron Dextran in Suckling Piglets

Directory of Open Access Journals (Sweden)

M. Svoboda

2007-01-01

Full Text Available The aim of the study was to compare the development of red blood cell indices after subcutaneous versus intramuscular administration of iron dextran to suckling piglets during early postnatal period. The piglets in group I (n = 17 were injected subcutaneously (into groin with 200 mg Fe3+ as iron dextran on day 3 of life. In group II (n = 16, the piglets received intramuscular injection (into gluteal muscles of 200 mg Fe3+ as iron dextran on day 3 of life. In group III (n = 10, the piglets did not receive any iron till the age of 3 days. The blood was taken and analyzed (Hb, PCV, RBC, MCV, MCH, MCHC, Fe on days 3, 7, 14, 21, 28 and 35. Haematological indices of piglets in group III were characteristic for hypochromic anaemia. Anaemia in group III had a detrimental effect on the growth rate of piglets. The development of red blood cell indices and iron concentration in blood plasma in subcutaneously treated piglets did not differ significantly from that of intramuscularly-treated group. Both treatments prevented development of anaemia.

Cost-minimization analysis of subcutaneous abatacept in the treatment of rheumatoid arthritis in Spain

Directory of Open Access Journals (Sweden)

R. Ariza

2014-07-01

Full Text Available Objective: To compare the cost of treating rheumatoid arthritis patients that have failed an initial treatment with methotrexate, with subcutaneous aba - tacept versus other first-line biologic disease-modifying antirheumatic drugs. Method: Subcutaneous abatacept was considered comparable to intravenous abatacept, adalimumab, certolizumab pegol, etanercept, golimumab, infliximab and tocilizumab, based on indirect comparison using mixed treatment analysis. A cost-minimization analysis was therefore considered appropriate. The Spanish Health System perspective and a 3 year time horizon were selected. Pharmaceutical and administration costs (, 2013 of all available first-line biological disease-modifying antirheumatic drugs were considered. Administration costs were obtained from a local costs database. Patients were considered to have a weight of 70 kg. A 3% annual discount rate was applied. Deterministic and probabilistic sensitivity analyses were performed. Results: Subcutaneous abatacept proved in the base case to be less costly than all other biologic antirrheumatic drugs (ranging from -831.42 to -9,741.69 versus infliximab and tocilizumab, respectively. Subcutaneous abatacept was associated with a cost of 10,760.41 per patient during the first year of treatment and 10,261.29 in subsequent years. The total 3-year cost of subcutaneous abatacept was 29,953.89 per patient. Sensitivity analyses proved the model to be robust. Subcutaneous abatacept remained cost-saving in 100% of probabilistic sensitivity analysis simulations versus adalimumab, certolizumab, etanercept and golimumab, in more than 99.6% versus intravenous abatacept and tocilizumab and in 62.3% versus infliximab. Conclusions: Treatment with subcutaneous abatacept is cost-saving versus intravenous abatacept, adalimumab, certolizumab, etanercept, golimumab, infliximab and tocilizumab in the management of rheumatoid arthritis patients initiating

Relationship Between Cerebral Oxygenation and Hemodynamic and Oxygen Transport Parameters in Surgery for Acquired Heart Diseases

Directory of Open Access Journals (Sweden)

A. I. Lenkin

2012-01-01

Full Text Available Objective: to evaluate the relationship between cerebral oxygenation and hemodynamic and oxygen transport parameters in surgical correction of concomitant acquired heart diseases. Subjects and methods. Informed consent was received from 40 patients who required surgery because of concomitant (two or more acquired heart defects. During procedure, perioperative monitoring of oxygen transport and cerebral oxygenation was performed with the aid of PiCCO2 monitor (Pulsion Medical Systems, Germany and a Fore-Sight cerebral oximeter (CASMED, USA. Anesthesia was maintained with propofol and fen-tanyl, by monitoring the depth of anesthesia. Early postoperative intensive therapy was based on the protocol for early targeted correction of hemodynamic disorders. Oxygen transport and cerebral oxygenation parameters were estimated intraopera-tively and within 24 postoperative hours. A statistical analysis including evaluation of Spearman correlations was performed with the aid of SPSS 15.0. Results. During perfusion, there was a relationship between cerebral oximetry values and hemat-ocrit levels, and oxygen partial pressure in the venous blood. Furthermore, a negative correlation between cerebral oximetry values and blood lactate levels was found 30 minutes after initiation of extracorporeal circulation (EC. During the study, there was a positive correlation between cerebral oxygenation and values of cardiac index, central venous saturation, and oxygen delivery index. There was a negative relationship between cerebral oxygenation and extravascular lung water at the beginning of surgery and a correlation between cerebral oximetry values and oxygenation index by the end of the first 24 postoperative hours. Conclusion. The cerebral oxygenation values correlate -with the main determinants of oxygen transport during EC and after cardiac surgical procedures. Cerebral oximetry may be used in early targeted therapy for the surgical correction of acquired combined

Subcutaneous panniculitis-like T-cell lymphoma

Directory of Open Access Journals (Sweden)

Francis Abel

2010-01-01

Full Text Available This case report describes a 38 year-old lady with the clinical, histopathological, and immunohistochemical (IHC changes of subcutaneous panniculitis-like T-cell lymphoma (SPTCL. The IHC findings revealed CD8 + and CD56 - cells, which are indicative of tumors which have an indolent course. Our patient is being managed with tapering doses of corticosteroids for the last nine months with good improvement.

Determination of optimized oxygen partial pressure to maximize the liver regenerative potential of the secretome obtained from adipose-derived stem cells.

Science.gov (United States)

Lee, Sang Chul; Kim, Kee-Hwan; Kim, Ok-Hee; Lee, Sang Kuon; Hong, Ha-Eun; Won, Seong Su; Jeon, Sang-Jin; Choi, Byung Jo; Jeong, Wonjun; Kim, Say-June

2017-08-03

A hypoxic-preconditioned secretome from stem cells reportedly promotes the functional and regenerative capacity of the liver more effectively than a control secretome. However, the optimum oxygen partial pressure (pO 2 ) in the cell culture system that maximizes the therapeutic potential of the secretome has not yet been determined. We first determined the cellular alterations in adipose tissue-derived stem cells (ASCs) cultured under different pO 2 (21%, 10%, 5%, and 1%). Subsequently, partially hepatectomized mice were injected with the secretome of ASCs cultured under different pO 2 , and then sera and liver specimens were obtained for analyses. Of all AML12 cells cultured under different pO 2 , the AML12 cells cultured under 1% pO 2 showed the highest mRNA expression of proliferation-associated markers (IL-6, HGF, and VEGF). In the cell proliferation assay, the AML12 cells cultured with the secretome of 1% pO 2 showed the highest cell proliferation, followed by the cells cultured with the secretome of 21%, 10%, and 5% pO 2 , in that order. When injected into the partially hepatectomized mice, the 1% pO 2 secretome most significantly increased the number of Ki67-positive cells, reduced serum levels of proinflammatory mediators (IL-6 and TNF-α), and reduced serum levels of liver transaminases. In addition, analysis of the liver specimens indicated that injection with the 1% pO 2 secretome maximized the expression of the intermediate molecules of the PIP3/Akt and IL-6/STAT3 signaling pathways, all of which are known to promote liver regeneration. The data of this study suggest that the secretome of ASCs cultured under 1% pO 2 has the highest liver reparative and regenerative potential of all the secretomes tested here.

Subcutaneous endoscopically assisted ligation using miniport for ...

African Journals Online (AJOL)

miniport for the treatment of girls with inguinal hernia. Akinari Hinoki*, Ikeda ... method using subcutaneous endoscopically assisted ligation (SEAL) for the ... the open technique and an additional 2 mm miniport). A ... (unilateral, n = 9) or 42 ± 8 min (bilateral, n = 5). The mean .... Methods of laparoscopic repair have recently ...

Oxidation and microstrucure of V-Cr-Ti alloys exposed to oxygen-containing environments

Energy Technology Data Exchange (ETDEWEB)

Natesan, K. [Argonne National Lab., IL (United States); Uz, M. [Lafayette College, Easton, PA (United States); Ulie, T.

1997-08-01

The objectives of this task are to (a) evaluate the oxygen uptake of several V-Cr-Ti alloys as a function of temperature and oxygen partial pressure in the exposure environment, (b) examine the microstructural characteristics of oxide scales and oxygen trapped at the grain boundaries in the substrate alloys, and (c) evaluate the influence of alloy composition on oxygen uptake and develop correlation(s) between alloy composition, exposure environment, and temperature.

Oxidation and microstrucure of V-Cr-Ti alloys exposed to oxygen-containing environments

International Nuclear Information System (INIS)

Natesan, K.; Uz, M.; Ulie, T.

1997-01-01

The objectives of this task are to (a) evaluate the oxygen uptake of several V-Cr-Ti alloys as a function of temperature and oxygen partial pressure in the exposure environment, (b) examine the microstructural characteristics of oxide scales and oxygen trapped at the grain boundaries in the substrate alloys, and (c) evaluate the influence of alloy composition on oxygen uptake and develop correlation(s) between alloy composition, exposure environment, and temperature

Imaging features in calcinosis circumscripta, a rare type of subcutaneous calcification in localized scleroderma

Directory of Open Access Journals (Sweden)

Pratiksha Yadav

2013-01-01

Full Text Available Calcinosis cutis circumscripta is a rare condition in which abnormal deposition of calcium seen in the dermis and subcutaneous tissue, it is associated with localized scleroderma. A 30-year-old female presented with an area of extensive calcification involving the right gluteal region, lateral aspect of right thigh and a small area on left thigh detected on radiograph with atrophy of subcutaneous tissue. Magnetic resonance imaging and computed tomography were done for further evaluation and the findings were of calcification and atrophy involving the skin and subcutaneous tissue.

Abdominal Subcutaneous Fat Thickness Measured by Ultrasonography Correlates with Hyperlipidemia and Steatohepatitis in Obese Children.

Science.gov (United States)

Lee, Sung Hyun; Kim, Dongwan; Baek, Min Young; Tchah, Hann; Kim, Yeon Sun; Ryoo, Eell; Kim, Yun Mi

2015-06-01

The aim of this study is to evaluate the relationship between abdominal subcutaneous fat thickness measured by ultrasonography (US) and serum lipid profile and liver transaminases in obese children. One hundred and sixty-six children diagnosed with obesity from May 2001 to December 2013 were included in this study. Data on serum lipid profile and liver transaminases were collected from clinical records. Abdominal subcutaneous fat thickness and grade of hepatic steatosis were evaluated by US. Of the 166 children, 107 were diagnosed with hepatic steatosis by US, 46 with grade I, 56 with grade II, and five children with grade III. According to the grade of hepatic steasosis, the average values of midline abdominal subcutaneous fat thickness and right flank abdominal subcutaneous fat thickness measured 2.9±0.8 cm and 1.9±0.7 cm in the normal group, 3.3±0.8 cm and 2.0±0.7 cm in grade I, 3.8±0.8 cm and 2.3±0.8 cm in grade II, and 4.1±0.8 cm and 2.8±1.4 cm in grade III, respectively. Abdominal subcutaneous fat thickness correlated with grade of hepatic steatosis (pabdominal subcutaneous fat thickness correlated with concentration of serum lipids and liver transaminases in the age group of 12-14 years (pAbdominal subcutaneous fat thickness measured by US can be used as a reliable predictor of possible hyperlipidemia and steatohepatitis in children, especially during the adolescent stage.

EEG Signal Quality of a Subcutaneous Recording System Compared to Standard Surface Electrodes

Directory of Open Access Journals (Sweden)

Jonas Duun-Henriksen

2015-01-01

Full Text Available Purpose. We provide a comprehensive verification of a new subcutaneous EEG recording device which promises robust and unobtrusive measurements over ultra-long time periods. The approach is evaluated against a state-of-the-art surface EEG electrode technology. Materials and Methods. An electrode powered by an inductive link was subcutaneously implanted on five subjects. Surface electrodes were placed at sites corresponding to the subcutaneous electrodes, and the EEG signals were evaluated with both quantitative (power spectral density and coherence analysis and qualitative (blinded subjective scoring by neurophysiologists analysis. Results. The power spectral density and coherence analysis were very similar during measurements of resting EEG. The scoring by neurophysiologists showed a higher EEG quality for the implanted system for different subject states (eyes open and eyes closed. This was most likely due to higher amplitude of the subcutaneous signals. During periods with artifacts, such as chewing, blinking, and eye movement, the two systems performed equally well. Conclusions. Subcutaneous measurements of EEG with the test device showed high quality as measured by both quantitative and more subjective qualitative methods. The signal might be superior to surface EEG in some aspects and provides a method of ultra-long term EEG recording in situations where this is required and where a small number of EEG electrodes are sufficient.

The indium-oxygen system, ch. 5

International Nuclear Information System (INIS)

Dillen, A.J. van

1977-01-01

This chapter is divided into three sections: 1) a survey of the literature concerning the indiumoxygen system, 2) the adsorption of oxygen at pure and partially oxidized indium surfaces in the temperature range 20-180degC, and 3) the oxidation of indium at temperatures above 180degC. The oxygen uptake is determined volumetrically and gravimetrically. The influence of the melting point is considered and the results are compared with data from the literature. The oxide layer is amorphous at lower temperatures but above 350degC, crystallisation of In 2 O 3 takes place

Oxygen diffusion in high-Tc superconductors

International Nuclear Information System (INIS)

Rothman, S.J.; Routbort, J.L.

1992-07-01

The cuprate superconductors are fascinating not only because of their technical promise, but also because of their structures, especially the anisotropy of the crystal lattice. There are some structural similarities among these compounds, but also significant differences. Measurements of the oxygen tracer diffusion coefficients have been carried out as a function of temperature, oxygen partial pressure, crystal orientation, and doping in the La-Sr-Cu-0, Y-Ba-Cu-0, and Bi-Sr-Ca-Cu-0 systems. These measurements have revealed a variety of defect mechanisms operating in these compounds; the exact nature of the mechanism depends on the details of the structure

Radionuclide venography of lower limbs by subcutaneous injection

International Nuclear Information System (INIS)

Wu, Chung-Chieng; Jong, Shiang-Bin

1989-01-01

We have proved that subcutaneous injection (SC) of a small dose of Tc-99m pertechnetate (1 to 2 mCi: 37 to 74 MBq) at acupuncture points (K-3 and B-60) may offer an alternative method of radionuclide venography (RNV) of the lower limbs. In this study, we compared intravenous (IV) RNV and SC-RNV in 22 consecutive cases with typical signs and symptoms suggesting venous abnormality of the lower limb(s) from March to May 1988. They are 11 male and 11 female, aged 47.7±15.7 years. Among the 44 limbs of the 22 cases, 4 were normal, 12 (27.3%) were found to have varicose veins in the legs only, 18 (40.9%) had partial stenosis of the deep veins (14 poplito-tibial and 4 superficial femoral), and 13 (29.6%) had complete stenosis of the deep veins (4 poplito-tibial, 1 superficial femoral and 8 ilio-femoral. SC-RNV showed almost the same results as IV-RNV in 21 (47.7%), superior to IV-RNV in 22 (50%) (including 4.6% failure of IV-RNV), and inferior to IV-RNV in 1 (2.3%). We conclude that SC-RNV is definitely an alternative method of lower-limb venography. Since it is in most cases superior to IV-RNV, we suggest that it can take the place of IV-RNV in routine work. (author) 62 refs

Partial neuromuscular blockade in humans enhances muscle blood flow during exercise independently of muscle oxygen uptake and acetylcholine receptor blockade

DEFF Research Database (Denmark)

Hellsten, Ylva; Krustrup, Peter; Iaia, F Marcello

2009-01-01

This study examined the role of acetylcholine for skeletal muscle blood flow during exercise by use of the competitive neuromuscular blocking agent cisatracurium in combination with the acetylcholine receptor blocker glycopyrrone. Nine healthy male subjects performed a 10-min bout of one-legged k......This study examined the role of acetylcholine for skeletal muscle blood flow during exercise by use of the competitive neuromuscular blocking agent cisatracurium in combination with the acetylcholine receptor blocker glycopyrrone. Nine healthy male subjects performed a 10-min bout of one...... conductance during exercise, events that are not associated with either acetylcholine or an increased oxygen demand. The results do not support an essential role for acetylcholine, released form the neuromuscular junction, in exercise hyperaemia or for the enhanced blood flow during neuromuscular blockade....... The enhanced exercise hyperemia during partial neuromuscular blockade may be related to a greater recruitment of fast-twitch muscle fibres. Key words: blood flow, neuromuscular blockade, exercise, skeletal muscle....

Evaluation of pharmacokinetic model designs for subcutaneous infusion of insulin aspart

DEFF Research Database (Denmark)

Mansell, Erin J.; Schmidt, Signe; Docherty, Paul D.

2017-01-01

Effective mathematical modelling of continuous subcutaneous infusion pharmacokinetics should aid understanding and control in insulin therapy. Thorough analysis of candidate model performance is important for selecting the appropriate models. Eight candidate models for insulin pharmacokinetics...... included a range of modelled behaviours, parameters and complexity. The models were compared using clinical data from subjects with type 1 diabetes with continuous subcutaneous insulin infusion. Performance of the models was compared through several analyses: R2 for goodness of fit; the Akaike Information...

Partial nitrification using aerobic granules in continuous-flow reactor: rapid startup.

Science.gov (United States)

Wan, Chunli; Sun, Supu; Lee, Duu-Jong; Liu, Xiang; Wang, Li; Yang, Xue; Pan, Xiangliang

2013-08-01

This study applied a novel strategy to rapid startup of partial nitrification in continuous-flow reactor using aerobic granules. Mature aerobic granules were first cultivated in a sequencing batch reactor at high chemical oxygen demand in 16 days. The strains including the Pseudoxanthomonas mexicana strain were enriched in cultivated granules to enhance their structural stability. Then the cultivated granules were incubated in a continuous-flow reactor with influent chemical oxygen deamnad being stepped decreased from 1,500 ± 100 (0-19 days) to 750 ± 50 (20-30 days), and then to 350 ± 50 mg l(-1) (31-50 days); while in the final stage 350 mg l(-1) bicarbonate was also supplied. Using this strategy the ammonia-oxidizing bacterium, Nitrosomonas europaea, was enriched in the incubated granules to achieve partial nitrification efficiency of 85-90% since 36 days and onwards. The partial nitrification granules were successfully harvested after 52 days, a period much shorter than those reported in literature. Copyright © 2013 Elsevier Ltd. All rights reserved.

Development of oxygen sensing technology in an irradiated fuel rod. Characteristic test of oxygen sensor

International Nuclear Information System (INIS)

Saito, Junichi; Hoshiya, Taiji; Sakurai, Fumio; Sakai, Haruyuki

1996-03-01

At the Department of JMTR (Japan Materials Test Reactor), the re-instrumentation technologies to a high burnup fuel rod irradiated in an LWR have been developed to study irradiation behavior of the fuel during power transient. It has been progressed developing a chemical sensor as one of the re-instrumentation technologies. This report summarizes the results of characteristic tests of an oxygen sensor made of Yttria Stabilized Zirconia (YSZ) as a solid electrolyte. Several kinds of experiments were carried out to evaluate the electromotive force (emf) performance, stability and lifetime of the oxygen sensor with Ni/NiO, Cr/Cr 2 O 3 and Fe/FeO, respectively as a reference electrode. From the experimental data, it is suggested that the reference electrode of Ni/NiO reveals the most appropriate characteristic of the sensor to measure the partial oxygen pressure in a fuel rod. It is the final goal of this development to clarify the change of oxygen chemical potential in a fuel rod during power transient. (author)

Oxidation behavior of V-Cr-Ti alloys in low-partial-pressure oxygen environments

International Nuclear Information System (INIS)

Natesan, K.; Uz, M.

1998-01-01

A test program is in progress at Argonne National Laboratory to evaluate the effect of pO 2 in the exposure environment on oxygen uptake, scaling kinetics, and scale microstructure in V-Cr-Ti alloys. The data indicate that the oxidation process follows parabolic kinetics in all of the environments used in the present study. From the weight change data, parabolic rate constants were evaluated as a function of temperature and exposure environment. The temperature dependence of the parabolic rate constants was described by an Arrhenius relationship. Activation energy for the oxidation process was fairly constant in the oxygen pressure range of 1 x 10 -6 to 1 x 10 -1 torr for both the alloys. The activation energy for oxidation in air was significantly lower than in low-pO 2 environments, and for oxidation in pure O 2 at 760 torr was much lower than in low-pO 2 environments. X-ray diffraction analysis of the specimens showed that VO 2 was the dominant phase in low-pO 2 environments, while V 2 O 5 was dominant in air and in pure oxygen at 76f0 torr

Are there sex differences in Fetal Abdominal Subcutaneous Tissue (FAST) measurements?

LENUS (Irish Health Repository)

Farah, Nadine

2012-02-01

OBJECTIVE: To determine if Fetal Abdominal Subcutaneous Tissue (FAST) measurements using antenatal ultrasound differ between male and female fetuses. STUDY DESIGN: Women who had an ultrasound examination for fetal growth between 20 and 40 weeks gestation were studied. Women with diabetes mellitus were excluded. The fetal anterior abdominal subcutaneous tissue was measured on the anterior abdominal wall in millimetres anterior to the margins of the ribs, using magnification at the level of the abdominal circumference. The fetal sex was recorded after delivery. RESULTS: A total of 557 fetuses were measured, 290 male and 267 female. The FAST measurements increased with gestational age. The FAST increased at the same rate for both male and female fetuses and at any given week there was no sex difference. CONCLUSIONS: The increased fat composition in females reported after birth was not found in abdominal wall subcutaneous fat measurements using ultrasound during pregnancy. Antenatal centile charts for FAST do not need to be based on sex.

Partial clinical response to anakinra in severe palmoplantar pustular psoriasis.

Science.gov (United States)

Tauber, M; Viguier, M; Alimova, E; Petit, A; Lioté, F; Smahi, A; Bachelez, H

2014-09-01

Palmoplantar pustular psoriasis is a clinical psoriasis variant characterised by a high impact on quality of life and poor response to biologics approved for plaque type psoriasis.The recombinant interleukin-1 (IL-1) receptor antagonist anakinra has been recently used for the treatment of isolated refractory cases of generalised pustular psoriasis with contrasted results. To report the clinical response in two patients treated with anakinra as salvage therapy in two patients with severe palmoplantar pustular psoriasis refractory to currently available antipsoriatic systemic therapies. Anakinra was given subcutaneously at the daily dose of 100 mg, and clinical response was evaluated using the palmoplantar psoriasis area and severity index (PPPASI). Only partial and transient responses were observed in both patients, who had to stop anakinra due to lack of efficacy and to side effects. Anakinra appears to provide only partial clinical improvement in refractory palmoplantar pustular psoriasis. Prospective clinical studies on larger populations are warranted to investigate more accurately both efficacy and safety of IL-1-inhibiting strategies in pustular psoriasis. © 2014 British Association of Dermatologists.

'Multi-associations': predisposed to misinterpretation of peripheral tissue oxygenation and circulation in neonates

International Nuclear Information System (INIS)

Pichler, Gerhard; Pocivalnik, Mirjam; Pichler-Stachl, Elisabeth; Morris, Nicholas; Zotter, Heinz; Müller, Wilhelm; Urlesberger, Berndt; Riedl, Regina

2011-01-01

Interpretation of peripheral circulation in ill neonates is crucial but difficult. The aim was to analyse parameters potentially influencing peripheral oxygenation and circulation. In a prospective observational cohort study in 116 cardio-circulatory stable neonates, peripheral muscle near-infrared spectroscopy (NIRS) with venous occlusion was performed. Tissue oxygenation index (TOI), mixed venous oxygenation (SvO 2 ), fractional oxygen extraction (FOE), fractional tissue oxygen extraction (FTOE), haemoglobin flow (Hbflow), oxygen delivery (DO 2 ), oxygen consumption (VO 2 ), and vascular resistance (VR) were assessed. Correlation coefficients between NIRS parameters and demographic parameters (gestational age, birth weight, age, actual weight, diameter of calf, subcutaneous adipose tissue), monitoring parameters (heart rate, arterial oxygen saturation (SaO 2 ), mean blood pressure (MAP), core/peripheral temperature, central/peripheral capillary refill time) and laboratory parameters (haemoglobin concentration (Hb-blood), pCO 2 ) were calculated. All demographic parameters except for Hbflow and DO 2 correlated with NIRS parameters. Heart rate correlated with TOI, SvO 2 , VO 2 and VR. SaO 2 correlated with FOE/FTOE. MAP correlated with Hbflow, DO 2 , VO 2 and VR. Core temperature correlated with FTOE. Peripheral temperature correlated with all NIRS parameters except VO 2 . Hb-blood correlated with FOE and VR. pCO 2 levels correlated with TOI and SvO 2 . The presence of multiple interdependent factors associated with peripheral oxygenation and circulation highlights the difficulty in interpreting NIRS data. Nevertheless, these findings have to be taken into account when analysing peripheral oxygenation and circulation data

The utility of midtrimester ultrasound assessment of the subcutaneous space in predicting cesarean wound complications

Science.gov (United States)

Shainker, Scott A.; Raghuraman, Nandini; Modest, Anna M.; Schnettler, William T.; Hacker, Michele R.; Ralston, Steven J.

2016-01-01

Objective To evaluate the association between cesarean wound complications and thickness of the subcutaneous space within the anterior abdomen at the midtrimester fetal anatomical survey. Methods In this case-control study, cases were identified using an ICD9 code for wound complications of cesarean delivery. For each case, we identified the woman with the next consecutive midtrimester ultrasound who had a cesarean delivery without a wound complication, matched on age and race, as the control. A blinded investigator measured subcutaneous space at three distinct suprapubic levels in the midsagital plane. Results Of 7228 women with a cesarean delivery, 123 (1.7%) had a wound complication. Seventy-nine cases were eligible. Midline suprapubic subcutaneous thickness did not differ between cases and controls at the superior, middle or inferior locations (p ≥ 0.35). Body mass index was moderately correlated with ultrasound-derived measurements (r≥ 0.63; p<0.001). The incidence of vertical skin incision, stapled skin closure and classical hysterotomy differed between groups (p≤ 0.046). There was no significant increase in wound complication risk with increasing subcutaneous space thickness, even after adjustment (p≥ 0.34). Conclusion Prenatal ultrasound can quantify the subcutaneous space. Vertical skin incision, stapled wound closure, and a classical hysterotomy were associated with cesarean wound complication, but midtrimester subcutaneous thickness was not. PMID:25302863

The Effect of Subcutaneous Ketamine Infiltration on Postoperative Pain in Elective Cesarean Section under Spinal Anesthesia

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N. Manouchehrian

2015-01-01

Full Text Available Introduction & Objective: Appropriate analgesia after cesarean section helps women feel more comfortable and increase the mobility of the mother's and also their ability to take better care of their newborns. The purpose of this study was to investigate the effects of subcutaneous infiltration of ketamine on postoperative pain reduction and hemodynamic status of patients after elective cesarean section. Materials & Methods: This study was designed as a double blinded prospective, randomized clinical trial and 60 cases of women undergoing elective cesarean section under spinal anes-thesia were randomly assigned into two groups. For 30 cases in the ketamine group, infiltra-tion of subcutaneous ketamine 0.5 mg / kg was administered after closure of surgical inci-sion. 30 patients in the placebo group received subcutaneous infiltration of saline. During the patient's recovery time and after transferring to the ward, the VAS of pain and vital signs were continuously assessed. if VAS ? 3, 100 mg diclofenac suppository was administered and if there were no response, 30 mg intravenous pethidine was also administered. Prescribed number of suppositories and pethidine dosage were compared. The complications, such as hallucination, nystagmus, nausea, vomiting and drowsiness in patients were also recorded and compared. Statistical analysis was performed by SPSS16 software and ?2 and t-test. P< 0.05 was considered statistically significant in all of the cases. Results: In the course of systolic blood pressure, heart rate and arterial blood oxygen satura-tion during the first 24 hours, no significant differences were mentioned between the two groups. At the time of arrival to the recovery room and 30 minutes later, the mean VAS was not significantly different in the groups. However, the mean VAS at 1, 2 , 4 , 6 , 8 and 12 hours after surgery were significantly lower in the ketamine group (0.61±059 than in the sa-line group (3.37±096 (P<0.001. The mean

Protein 53 expression in a mixed Labrador subcutaneous lymphoma

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Annahita Rezaie

2012-06-01

Full Text Available An 11 year – old mixed female Labrador was presented with two masses in trunk and neck. The tumoral masses were excised and sent for histopathological and immunohistochemical analyses. Histopathological examination of masses revealed diffuse infiltration of small sized lymphoid cells in subcutaneous tissue which were intense around the blood vessels. More than 10% lymphoid cells were CD3 positive in the immunohistochemical staining and most of them were accumulated around vessels. Protein 53 (p53 expression was detected by brown nuclei in immunohistochemical staining. Subcutaneous lymphoma was diagnosed according to histopathological results. After 6 months the case was referred with multicentric lymphoma and based on the owner request euthanasia was performed. These findings emphasize on poor prognosis for tumors with p53 mutation.

Evaluation of tissue oxygen measurements for flap monitoring in an animal model

DEFF Research Database (Denmark)

Bonde, Christian; Elberg, Jens; Holstein-Rathlou, N.-H.

2008-01-01

Tissue oxygen tension (p(ti)O(2)) measurements are common in neurosurgery but uncommon in plastic surgery. We examined this technique as a monitoring method with probe placement in the subcutaneous tissue and addressed the importance of probe placement. Myocutaneous flaps were raised in an animal...... model and p(ti)O(2) measurements performed at different levels in the subcutaneous fat. Flap artery and vein were occluded until a 50% p(ti)O(2) reduction had occurred (T(1/2)). We found no significant effect of depth (P>0.10) on the level of p(ti)O(2). T(1/2)(arterial) was 7.2 minutes and T(1/2)(venous......) was 18 minutes. We found no significant relation between initial levels of p(ti)O(2) and T(1/2). Location of the probe and absolute p(ti)O(2) value is of little relevance for flap monitoring. It is the relative change in p(ti)O(2) that is important. The p(ti)O(2) technique is well suited for monitoring...

A determination of the oxygen non-stoichiometry of the oxygen storage materials LnBaMn2O5+δ (Ln=Gd, Pr)

Science.gov (United States)

Jeamjumnunja, Kannika; Gong, Wenquan; Makarenko, Tatyana; Jacobson, Allan J.

2016-07-01

The A-site ordered double-perovskite oxides, LnBaMn2O5+δ (Ln=Gd, Pr), were synthesized and investigated to understand the effect of A site cation substitution on the oxygen storage properties of these materials. The present results are compared with our previous data for YBaMn2O5+δ. The results clearly reveal that changing the Ln cation strongly influences the oxidation/reduction behavior of LnBaMn2O5+δ. Based on thermogravimetric analysis data, oxygen uptake begins at lower temperatures in both air and oxygen in compounds with Ln3+ ions larger than Y3+. These oxides exhibit almost complete and reversible oxygen uptake/release between fully-reduced LnBaMn2O5 and fully-oxidized LnBaMn2O6 during changes of the oxygen partial pressure between air and 1.99% H2/Ar. In addition, the oxygen non-stoichiometries of GdBaMn2O5+δ and PrBaMn2O5+δ were determined as a function of pO2 at 600, 650, 700 and 750 °C by Coulometric titration at near-equilibrium conditions. The results confirm that these materials have two distinct phases on oxidation/reduction with δ≈0, 0.5 and a third phase with a range of composition with an oxygen content (5+δ) approaching 6. The stabilities of the LnBaMn2O5+δ phases extend over a wide range of oxygen partial pressures (∼10-25≤pO2 (atm)≤∼1) depending on temperature. Isothermal experiments show that the larger the Ln3+ cation the lower pO2 for phase conversion. At some temperatures and pO2 conditions, the LnBaMn2O5+δ compounds are unstable with respect to decomposition to BaMnO3-δ and LnMnO3. This instability is more apparent in Coulometric titration experiments than in thermogravimetric analysis. The Coulometric titration experiments are necessarily slow in order to achieve equilibrium oxygen compositions.

Heterozygous CAV1 frameshift mutations (MIM 601047 in patients with atypical partial lipodystrophy and hypertriglyceridemia

Directory of Open Access Journals (Sweden)

Alston Lindsay

2008-01-01

Full Text Available Abstract Background Mice with a deleted Cav1 gene encoding caveolin-1 develop adipocyte abnormalities and insulin resistance. From genomic DNA of patients with atypical lipodystrophy and hypertriglyceridemia who had no mutations in any known lipodystrophy gene, we used DNA sequence analysis to screen the coding regions of human CAV1 (MIM 601047. Results We found a heterozygous frameshift mutation in CAV1, designated I134fsdelA-X137, in a female patient who had atypical partial lipodystrophy, with subcutaneous fat loss affecting the upper part of her body and face, but sparing her legs, gluteal region and visceral fat stores. She had severe type 5 hyperlipoproteinemia, with recurrent pancreatitis. In addition, she had some atypical features, including congenital cataracts and neurological findings. Her father was also heterozygous for this mutation, and had a similar pattern of fat redistribution, hypertriglyceridemia and congenital cataracts, with milder neurological involvement. An unrelated patient had a different heterozygous frameshift mutation in the CAV1 gene, designated -88delC. He also had a partial lipodystrophy phenotype, with subcutaneous fat loss affecting the arms, legs and gluteal region, but sparing his face, neck and visceral fat stores. He also had severe type 5 hyperlipoproteinemia, with recurrent pancreatitis; however he had no clinically apparent neurological manifestations. The mutations were absent from the genomes of 1063 healthy individuals. Conclusion Thus, very rare CAV1 frameshift mutations appear to be associated with atypical lipodystrophy and hypertriglyceridemia.

Worldwide experience with a totally subcutaneous implantable defibrillator

DEFF Research Database (Denmark)

Lambiase, Pier D; Barr, Craig; Theuns, Dominic A M J

2014-01-01

AIMS: The totally subcutaneous implantable-defibrillator (S-ICD) is a new alternative to the conventional transvenous ICD system to minimize intravascular lead complications. There are limited data describing the long-term performance of the S-ICD. This paper presents the first large internationa...

PHAEOHYPHOMYCOSIS: CUTANEOUS, SUBCUTANEOUS, NASOPHARYNGEAL LESIONS

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M. Rasoolinejad

1999-06-01

Full Text Available Phaeohyphomycosis is an amalgam of clinical diseases caused by a wide variety of dematiaceous fungi. We are reporting on a 16 year-old patient from Amol with subcutaneous cervical nodes and nasopharyngeal lesions of phaeohypho"nmycosis that were confirmed by pathological examination, direct smear, and culture. After treatment with an oral triazole (Itraconazole for 4 months, all nodes and lesions disappeared and treatment was stopped A new lesion appeared on his chest wall 8 months, therapy with itraconazole was restarted and commuted for a long time.

Radioprotection of mouse skin by WR-2721: the critical influence of oxygen tension

International Nuclear Information System (INIS)

Denekamp, J.; Michael, B.D.; Rojas, A.; Stewart, F.A.

1982-01-01

The epidermal clone assay has been used to study the radioprotective effect of WR-2721 on mouse skin under different conditions of oxygenation and under anoxia. The skin has shown a progressive decrease in sensitivity as the inspired gas has changed from 100% oxygen towards 0% oxygen. Compared with mice breathning 100% oxygen, those breathing air are partially protected. The inspired oxygen concentration to give half the full oxygen effect is 10-12%. The radioprotecton observed with 400 mg/kg WR-2721 is markedly dependent on the ambient oxygen concentration. The protection factor is 1.1 or less in mice breathing 5%, 1% or 0% oxygen. Protection is maximal (1.95) in air and in 50% oxygen and diminishes to 1.6 at higher oxygen tensions

Comparison of Mucosal, Subcutaneous and Intraperitoneal Routes of Rat Leptospira Infection

Science.gov (United States)

Zilber, Anne-Laure; Belli, Patrick; Grezel, Delphine; Artois, Marc; Kodjo, Angeli; Djelouadji, Zoheira

2016-01-01

Leptospirosis is a zoonosis found worldwide that is caused by a spirochete. The main reservoirs of Leptospira, which presents an asymptomatic infection, are wild rodents, including the brown rat (Rattus norvegicus). Experimental studies of the mechanisms of its renal colonization in rats have previously used an intraperitoneal inoculation route. However, knowledge of rat-rat transmission requires the use of a natural route of inoculation, such as a mucosal or subcutaneous route. We investigated for the first time the effects of subcutaneous and mucosal inoculation routes compared to the reference intraperitoneal route during Leptospira infection in adult rats. Infection characteristics were studied using Leptospira renal isolation, serology, and molecular and histological analyses. Leptospira infection was asymptomatic using each inoculation route, and caused similar antibody production regardless of renal colonization. The observed renal colonization rates were 8 out of 8 rats, 5 out of 8 rats and 1 out of 8 rats for the intraperitoneal, mucosal and subcutaneous inoculation routes, respectively. Thus, among the natural infection routes studied, mucosal inoculation was more efficient for renal colonization associated with urinary excretion than the subcutaneous route and induced a slower-progressing infection than the intraperitoneal route. These results can facilitate understanding of the infection modalities in rats, unlike the epidemiological studies conducted in wild rats. Future studies of other natural inoculation routes in rat models will increase our knowledge of rat-rat disease transmission and allow the investigation of infection kinetics. PMID:27031867

Clinical Trial of Subcutaneous Steroid Injection in Patients with Migraine Disorder

Directory of Open Access Journals (Sweden)

Karim Nikkhah

2016-02-01

Full Text Available Background: Neurologic literature on therapeutic effect of subcutaneous corticosteroids in patients with migrainous chronic daily headache is scarce. The aim of this research is to assess the therapeutic effects of this management in such patients. Methods: Consecutive patients with migrainous chronic daily headache enrolled a prospective before-after therapeutic study during 2010-2013. Methylprednisolone 40 mg was divided into four subcutaneous injection doses. Two injections were administered in the right and left suboccipital area (exactly at retromastoid cervicocranial junction and the other two injections in the lower medial frontal area (exactly at medial right and left eyebrows. A daily headache diary was filled out by the patients before and one month after the intervention. The severity of pain was classified based on a pain intensity instrument using numeric rating scale from 0-10 point scale. Paired t-test and Chi-square test were used for statistical analysis. Results: 504 patients (378 females, 126 males with migrainous chronic daily headache were enrolled in the study. Dramatic, significant, moderate, mild, or no improvements respectively constituted 28.6%, 33.3%, 23.8%, and 14.3% of the post treatment courses. Therapeutic effect of intervention on mean pain scores was significant; t=7.38, df=20, P=0.000. Two cases developed subcutaneous fat atrophy in frontal injection site and three cases experienced syncope during injection. Conclusion: Subcutaneous corticosteroids could be used as an adjunct therapy in patients with migrainous chronic daily headache.

Tailoring nanomaterial products through electrode material and oxygen partial pressure in a mini-arc plasma reactor

International Nuclear Information System (INIS)

Cui Shumao; Mattson, Eric C.; Lu, Ganhua; Hirschmugl, Carol; Gajdardziska-Josifovska, Marija; Chen Junhong

2012-01-01

Nanomaterials with controllable morphology and composition are synthesized by a simple one-step vapor condensation process using a mini-arc plasma source. Through systematic investigation of mini-arc reactor parameters, the roles of carrier gas, electrode material, and precursor on producing diverse nanomaterial products are revealed. Desired nanomaterial products, including tungsten oxide nanoparticles (NPs), tungsten oxide nanorods (NRs), tungsten oxide and tin oxide NP mixtures and pure tin dioxide NPs can thus be obtained by tailoring reaction conditions. The amount of oxygen in the reactor is critical to determining the final nanomaterial product. Without any precursor material present, a lower level of oxygen in the reactor favors the production of W 18 O 49 NRs with tungsten as cathode, while a high level of oxygen produces more round WO 3 NPs. With the presence of a precursor material, amorphous particles are favored with a high ratio of argon:oxygen. Oxygen is also found to affect tin oxide crystallization from its amorphous phase in the thermal annealing. Results from this study can be used for guiding gas phase nanomaterial synthesis in the future.

Effect of oxygen on the properties of Y-Ba-CuO ceramics

International Nuclear Information System (INIS)

Nemoshkalenko, V.V.; Ivanov, M.A.; Klimenko, G.A.

1988-01-01

The samples of Y-Ba-CuO ceramics 60x60x60 mm 3 in size were synthesized and investigated with provision for their impurity content, crystallography, superconductive and magnetic properties. The conditions of low temperature thermal treatments, as compared to the sintering ones, are offered that result in degradation of superconductive properties due to partial oxygen removal and their subsequent recovery. The mechanism of copper spin-paramagnetism growth in oxygen-deficient samples is discussed. The intensity of narrow (∼ 3 mrad half-width) component observed in the angular distribution of annihilation photons of partially de-oxygenized sample is found to increase in a constant magnetic field, suggesting the formation of positronium-like states. The intense CuOEH + 2 emission line is shown to be present in the spectra of superconductive samples, while it is absent in the non-superconductive state

Subcutaneous administration of carrier erythrocytes: slow release of entrapped agent

International Nuclear Information System (INIS)

DeLoach, J.R.; Corrier, D.E.

1988-01-01

Carrier erythrocytes administered subcutaneously in mice release encapsulated molecules at the injection site and through cells that escape the injection site. One day postinjection, the efflux of encapsulated [ 14 C]sucrose, [ 3 H]inulin, and 51 Cr-hemoglobin from the injection site was 45, 55, and 65%, respectively. Intact carrier erythrocytes escaped the injection site and entered the blood circulation carrying with them the encapsulated molecules. Most of the encapsulated [ 3 H]inulin that reached whole blood circulated within erythrocytes. Small but measurable numbers of encapsulated molecules were trapped within lymph nodes. Subcutaneous injection of carrier erythrocytes may allow for limited extravascular tissue targeting of drugs

The Upside-Down Biosphere: Evidence for the Partially Oxygenated Oceans During the Archean Eon

Science.gov (United States)

Domagal-Goldman, Shawn

2014-01-01

This is a commentary on the preceding chapter by Ohmoto et al., in which it is suggested that oxygen concentrations have been high throughout Earth history. This is a contentious suggestion at odds with the prevailing view in the field, which contends that atmospheric oxygen concentrations rose from trace levels to a few percent of modern-day levels around 2.5 b.y. ago. This comment notes that many of the data sets cited by Ohmoto et al. as evidence for a relatively oxidized environment come from deep-ocean settings. This presents a possibility to reconcile some of these data and suggestions with the overwhelming evidence for an atmosphere free of oxygen at that time. Specifically, it is possible that deep-ocean waters were relatively oxidized with respect to certain redox pairs. These deep-ocean waters would have been more oxidized than surface waters, thus representing an "upside-down biosphere," as originally proposed 25 years ago by Jim Walker.

Hypoxia Tolerance and Metabolic Suppression in Oxygen Minimum Zone Euphausiids: Implications for Ocean Deoxygenation and Biogeochemical Cycles

KAUST Repository

Seibel, Brad A.; Schneider, Jillian L.; Kaartvedt, Stein; Wishner, Karen F.; Daly, Kendra L.

2016-01-01

respiration experiments. Critical oxygen partial pressures were estimated for each species, and, for E. eximia, measured via oxygen consumption (2.1 kPa, 10 °C, n = 2) and lactate accumulation (1.1 kPa, 10 °C). A primary mechanism facilitating low oxygen

Study of the oxygen and substrate bias effects on the defect structure of reactive sputter-deposited SnOx films

International Nuclear Information System (INIS)

Misheva, M.; Nancheva, N.; Docheva, P.; Hadjijska, P.; Djourelov, N.; Elenkov, D.

1999-01-01

The effects of oxygen and substrate bias on the defect structure of reactive sputter-deposited SnOx films were investigated. Samples were analysed using transmission electron microscopy (TEM), transmission electron diffraction (TED), X-ray diffraction (XRD) and positron annihilation spectroscopy (PAS). The oxygen played an important role in the film growth and surface morphology. TEM, TED and XRD showed that increasing of the oxygen partial pressure leads to the formation of films with different crystal phases. The void sizes also depended on oxygen partial pressure. The positron lifetimes and their relative intensities depended on the void concentration, the partial annealing of the vacancies and oxidation of SnO to SnOx. This investigation also showed that the mechanical strength of the films obtained at negative substrate bias is higher and the concentration of vacancy defects is smaller, than in the films, prepared without substrate bias. (author)

Imaging characteristics of subcutaneous amyloid deposits in diabetic patients: the ''insulin ball''

Energy Technology Data Exchange (ETDEWEB)

Tanio, Noriko; Nozaki, Taiki; Matsusako, Masaki; Starkey, Jay [St. Luke' s International Hospital, Department of Radiology, Tokyo (Japan); Suzuki, Koyu [St. Luke' s International Hospital, Department of Pathology, Tokyo (Japan)

2018-01-15

The purpose of this study was to describe the imaging characteristics of subcutaneous amyloid deposits occurring at sites of insulin injection, commonly known as ''insulin balls,'' in diabetic patients on ultrasound, CT, and MRI with pathologic correlation. We retrospectively reviewed the radiographic findings of 14 lesions in 9 patients diagnosed with subcutaneous amyloid deposits at our institution between 2005-2015. Three board-certified radiologists analyzed the following: (1) the shape, size, margin, morphologic characteristics, and blood flow on US using the color Doppler signal, (2) shape, size, margin, attenuation, and presence or absence of contrast enhancement on CT, and (3) shape, size, margin, signal intensity, and presence or absence of contrast enhancement on MRI. All lesions showed ill-defined hypovascular subcutaneous nodules with irregular margins. The median diameter of lesions was 50.4 mm on US, 46.8 mm on CT, and 51.4 mm on MRI. The internal echogenicity of subcutaneous amyloid deposits was hypoechoic and heterogeneous on US. All lesions showed isodensity compared to muscle with irregular margins and minimal contrast enhancement on CT. Both T1- and T2-weighted MR images showed low signal intensity compared with subcutaneous fat. Normal diffusion and minimal contrast enhancement were seen. Subcutaneous amyloid deposits which cause insulin resistance are typically ill-defined and heterogeneous hypovascular subcutaneous nodules with irregular margins on imaging that correspond to insulin injection sites. It is also characteristic that T2WI shows low intensity compared with fat on MRI, reflective of the amyloid content. (orig.)

Imaging characteristics of subcutaneous amyloid deposits in diabetic patients: the ''insulin ball''

International Nuclear Information System (INIS)

Tanio, Noriko; Nozaki, Taiki; Matsusako, Masaki; Starkey, Jay; Suzuki, Koyu

2018-01-01

The purpose of this study was to describe the imaging characteristics of subcutaneous amyloid deposits occurring at sites of insulin injection, commonly known as ''insulin balls,'' in diabetic patients on ultrasound, CT, and MRI with pathologic correlation. We retrospectively reviewed the radiographic findings of 14 lesions in 9 patients diagnosed with subcutaneous amyloid deposits at our institution between 2005-2015. Three board-certified radiologists analyzed the following: (1) the shape, size, margin, morphologic characteristics, and blood flow on US using the color Doppler signal, (2) shape, size, margin, attenuation, and presence or absence of contrast enhancement on CT, and (3) shape, size, margin, signal intensity, and presence or absence of contrast enhancement on MRI. All lesions showed ill-defined hypovascular subcutaneous nodules with irregular margins. The median diameter of lesions was 50.4 mm on US, 46.8 mm on CT, and 51.4 mm on MRI. The internal echogenicity of subcutaneous amyloid deposits was hypoechoic and heterogeneous on US. All lesions showed isodensity compared to muscle with irregular margins and minimal contrast enhancement on CT. Both T1- and T2-weighted MR images showed low signal intensity compared with subcutaneous fat. Normal diffusion and minimal contrast enhancement were seen. Subcutaneous amyloid deposits which cause insulin resistance are typically ill-defined and heterogeneous hypovascular subcutaneous nodules with irregular margins on imaging that correspond to insulin injection sites. It is also characteristic that T2WI shows low intensity compared with fat on MRI, reflective of the amyloid content. (orig.)

High temperature thermodynamics of solutions of oxygen in vanadium, niobium and tantalum

International Nuclear Information System (INIS)

Boureau, G.; Gerdanian, P.

1981-01-01

The Tian-Calvet microcalorimetric method has been applied to the determination at 1323 K of ΔH(O 2 ), the partial molar enthalpy of mixing of oxygen in vanadium, niobium and tantalum. The present results are in good agreement with earlier studies using e.m.f. techniques. Nevertheless in the first two solutions, ΔH(O 2 ) has been found somewhat more negative than previously reported. The partial molar entropies of mixing have been recalculated. The low values of the excess entropies are explained by a strong increase of the Debye temperature and a decrease of the electronic density of states at the Fermi level as the oxygen content increases. (author)

[Experiences with a subcutaneous, fully resorbable bridge in construction a double loop ileo- and colostomy].

Science.gov (United States)

Wedell, J; Banzhaf, G; Meier zu Eissen, P; Schlageter, M

1990-01-01

Our experience with the subcutaneous absorbable bridge for constructing a temporary loop ileostomy and loop colostomy is described. The use of this subcutaneous absorbable bridge in 15 patients - 6 with loop ileostomy and 9 with loop colostomy - was almost without complications. The absorbable bridge is a progress for maturation of the stoma and for immediate postoperative as prospective fitting of a watertight appliance. The actual trend substituting the temporary loop colostomy by the loop ileostomy may be advanced by the unlimited use of the subcutaneous absorbable bridge for constructing a temporary loop ileostomy.

Localized Subcutaneous Acute Febrile Neutrophilic Dermatosis in a Dog

Directory of Open Access Journals (Sweden)

Karolin Schoellhorn

2012-01-01

Full Text Available A two-year-old spayed female mixed-breed dog was presented with a five-day history of hemorrhagic gastroenteritis and fever. On physical examination, the dog was lethargic and clinically dehydrated. The skin of the entire ventral abdomen extending to both flanks was erythematous, swollen and painful on palpation. Histopathological examination of skin biopsies revealed a severe diffuse neutrophilic dermatitis and panniculitis, resembling the subcutaneous form of Sweet’s syndrome in humans. A large part of the skin lesion developed full-thickness necrosis. After intensive care, three surgical wound debridements and wound adaptations, the wound healed by secondary intention within ten weeks. In the absence of infection of the skin or neoplasia, a diagnosis of neutrophilic dermatosis and panniculitis, resembling the subcutaneous form of acute febrile neutrophilic dermatosis, was made.

Growth of anodic oxide films on oxygen-containing niobium

Energy Technology Data Exchange (ETDEWEB)

Habazaki, H. [Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan)]. E-mail: habazaki@eng.hokudai.ac.jp; Ogasawara, T. [Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Konno, H. [Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Shimizu, K. [University Chemical Laboratory, Keio University, Yokohama 223-8522 (Japan); Asami, K. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Saito, K. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Nagata, S. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Skeldon, P. [Corrosion and Protection Centre, School of Materials, The University of Manchester, P.O. Box 88, Manchester M60 1QD (United Kingdom); Thompson, G.E. [Corrosion and Protection Centre, School of Materials, The University of Manchester, P.O. Box 88, Manchester M60 1QD (United Kingdom)

2005-09-20

The present study is directed at understanding of the influence of oxygen in the metal on anodic film growth on niobium, using sputter-deposited niobium containing from about 0-52 at.% oxygen, with anodizing carried out at high efficiency in phosphoric acid electrolyte. The findings reveal amorphous anodic niobia films, with no significant effect of oxygen on the field strength, transport numbers, mobility of impurity species and capacitance. However, since niobium is partially oxidized due to presence of oxygen in the substrate, less charge is required to form the films, hence reducing the time to reach a particular film thickness and anodizing voltage. Further, the relative thickness of film material formed at the metal/film interface is increased by the incorporation of oxygen species into the films from the substrate, with an associated altered depth of incorporation of phosphorus species into the films.

Pneumothorax and subcutaneous emphysema secondary to blunt chest injury

OpenAIRE

Porhomayon, Jahan; Doerr, Ralph

2011-01-01

This is the case of a patient with a history of blunt chest trauma associated with subcutaneous emphysema and pneumothorax. The patient complained of inspiratory stridor on presentation. Anatomical relationships can explain the pathophysiological process.

Oxygen depletion of bismuth molybdates

Energy Technology Data Exchange (ETDEWEB)

Yong, L.K.; Howe, R.F.; Keulks, G.W.; Hall, W.K.

1978-05-01

Pure ..cap alpha..-phase bismuth molybdate (Bi/sub 2/Mo/sub 3/O/sub 12/), which is known to be weakly active for selective oxidation, and pure ..gamma..-phase bismuth molybdate (Bi/sub 2/MoO/sub 6/), which has good activity, were subjected to oxidation-reduction cycles with known amounts of hydrogen and oxygen, at 300/sup 0/-570/sup 0/C and with evacuation steps between treatments. The volume of oxygen consumed during reoxidation was equal to half the hydrogen consumed during the reduction on the ..cap alpha..-phase, which indicated that no hydrogen was retained during reduction. For the ..gamma..-phase, the oxygen consumption was greater than half of the hydrogen consumption and it increased with extent of reduction. The excess oxygen was apparently consumed by filling anion vacancies formed during outgassing subsequent to the reduction step. ESR spectroscopy and temperature-programed oxidation-reduction indicated that lattice oxide ions which bridge between bismuth and molybdenum layers of the koechlinite structure become more labile when the catalyst is in a partially reduced state, and that this effect is greater in the ..gamma..- than the ..cap alpha..-phase. Table and 15 references.

Investigation of relation between visceral and subcutaneous abdominal fat volumes and calcified aortic plaques via multislice computed tomography.

Science.gov (United States)

Efe, Duran; Aygün, Fatih; Acar, Türker; Yildiz, Melda; Gemici, Kazım

2015-08-01

The present study investigated effect of subcutaneous fat volume and abdominal visceral fat volume on aortic atherosclerosis via multislice computed tomography. The present study comprised 424 subjects who underwent non-contrast-enhanced abdominal CT in our clinic between June 2012 and June 2013. Using dedicated software visceral fat volume was calculated for each individual and then subcutaneous fat volume was calculated by subtracting visceral fat volume from total fat volume. By dividing visceral fat volume/subcutaneous fat volume participants were assigned to three groups according to their mean visceral fat volume/subcutaneous fat volume: Group 1 consisted of subjects with visceral fat volume/subcutaneous fat volume lower than 0.48 (Group 1 fat volume/subcutaneous fat volume equal to or higher than 0.48 and lower than 0.69 (0.48 ≤ Group 2 fat volume/subcutaneous fat volume equal to or higher than 0.69 (Group 3 ≥ 0.69). The mean abdominal aortic calcium scores according to Agatston scoring (au) were 136.8 ± 418.7 au in Group 1, 179.9 ± 463 au in Group 2 and 212.2 ± 486.9 in Group 3, respectively. We have demonstrated a significant correlation between visceral fat volume and abdominal aorta atherosclerosis, while there was absence of significant correlation between subcutaneous fat volume and abdominal atherosclerosis. © The Author(s) 2014.

Oxygen nonstoichiometry and defects in Mn-doped Gd2Ti2O7+x

International Nuclear Information System (INIS)

Porat, O.; Tuller, H.L.

1996-01-01

The oxygen nonstoichiometry in Mn-doped Gd 2 Ti 2 O 7 , Gd 2 (Ti 0.975 Mn 0.025 ) 2 O 7+x , was measured electrochemically, as a function of temperature and oxygen partial pressure, with the aid of an oxygen titration cell. The analysis of the data shows that the defect equilibrium can be described by considering the dominant point defects to be neutral oxygen interstitials, doubly charged oxygen vacancies, and trivalent and quadrivalent Mn ions substituted in the Ti sites. The enthalpies for the formation of neutral oxygen interstitials and trivalent Mn are determined

Treatment with subcutaneous and transdermal fentanyl: Results from a population pharmacokinetic study in cancer patients

NARCIS (Netherlands)

A.W. Oosten (Astrid); J.A. Abrantes (João A.); S. Jönsson (Siv); P. de Bruijn (Peter); E.J.M. Kuip (Evelien); A. Falcão (Amílcar); C.C.D. van der Rijt (Carin); A.H.J. Mathijssen (Ron)

2016-01-01

textabstractPurpose: Transdermal fentanyl is effective for the treatment of moderate to severe cancer-related pain but is unsuitable for fast titration. In this setting, continuous subcutaneous fentanyl may be used. As data on the pharmacokinetics of continuous subcutaneous fentanyl are lacking, we

Subcutaneous face and neck surgical emphysema secondary to ...

African Journals Online (AJOL)

Subcutaneous face and neck surgical emphysema secondary to presumed spider bite. W Mulwafu. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

Gradually Increased Oxygen Administration Improved Oxygenation and Mitigated Oxidative Stress after Resuscitation from Severe Hemorrhagic Shock.

Science.gov (United States)

Luo, Xin; Yin, Yujing; You, Guoxing; Chen, Gan; Wang, Ying; Zhao, Jingxiang; Wang, Bo; Zhao, Lian; Zhou, Hong

2015-11-01

The optimal oxygen administration strategy during resuscitation from hemorrhagic shock (HS) is still controversial. Improving oxygenation and mitigating oxidative stress simultaneously seem to be contradictory goals. To maximize oxygen delivery while minimizing oxidative damage, the authors proposed the notion of gradually increased oxygen administration (GIOA), which entails making the arterial blood hypoxemic early in resuscitation and subsequently gradually increasing to hyperoxic, and compared its effects with normoxic resuscitation, hyperoxic resuscitation, and hypoxemic resuscitation in severe HS. Rats were subjected to HS, and on resuscitation, the rats were randomly assigned to four groups (n = 8): the normoxic, the hyperoxic, the hypoxemic, and the GIOA groups. Rats were observed for an additional 1 h. Hemodynamics, acid-base status, oxygenation, and oxidative injury were observed and evaluated. Central venous oxygen saturation promptly recovered only in the hyperoxic and the GIOA groups, and the liver tissue partial pressure of oxygen was highest in the GIOA group after resuscitation. Oxidative stress in GIOA group was significantly reduced compared with the hyperoxic group as indicated by the reduced malondialdehyde content, increased catalase activity, and the lower histologic injury scores in the liver. In addition, the tumor necrosis factor-α and interleukin-6 expressions in the liver were markedly decreased in the GIOA group than in the hyperoxic and normoxic groups as shown by the immunohistochemical staining. GIOA improved systemic/tissue oxygenation and mitigated oxidative stress simultaneously after resuscitation from severe HS. GIOA may be a promising strategy to improve resuscitation from HS and deserves further investigation.

Hyperbaric oxygen treatment for radiation proctitis

International Nuclear Information System (INIS)

Woo, Tony Choon Seng; Joseph, David; Oxer, Harry

1997-01-01

Purpose: Our objective was to assess, retrospectively, the efficacy of hyperbaric oxygen treatment in radiation proctitis in all patients who have completed treatment for this disease at the Fremantle Hyperbaric Oxygen Unit. This unit is the only one of its kind in Western Australia. Methods and Materials: Patients were assessed by a review of hospital records, blood bank records, and clinic review (if this was convenient), and all patients responded to a telephone survey. Patients were questioned regarding radiation proctitis symptoms and the degree to which each had improved. Results: Most patients had previously been treated with radiotherapy for prostate carcinoma. Patients with proctitis mainly suffered from bleeding, diarrhoea, incontinence, and pain. In more than half of these patients, symptoms partially or completely resolved after hyperbaric oxygen treatment. Conclusion: Radiation-induced proctitis is a difficult clinical problem to treat and will probably become more significant with the rising incidence of diagnosis of prostate cancer. Hyperbaric Oxygen should be considered in the treatment of radiation-induced proctitis. Further prospective trials with strict protocol guidelines are warranted

SIMS study of oxygen diffusion in monoclinic HfO2

Science.gov (United States)

Mueller, Michael P.; De Souza, Roger A.

2018-01-01

The diffusion of oxygen in dense ceramics of monoclinic HfO2 was studied by means of (18O/16O) isotope exchange annealing and subsequent determination of isotope depth profiles by Secondary Ion Mass Spectrometry. Anneals were performed in the temperature range of 573 ≤T /K ≤ 973 at an oxygen partial pressure of p O2=200 mbar . All measured isotope profiles exhibited two features: the first feature, closer to the surface, was attributed mainly to slow oxygen diffusion in an impurity silicate phase; the second feature, deeper in the sample, was attributed to oxygen diffusion in bulk monoclinic HfO2 . The activation enthalpy of oxygen tracer diffusion in bulk HfO2 was found to be ΔHD∗≈0.5 eV .

Diet-induced changes in subcutaneous adipose tissue blood flow in man

DEFF Research Database (Denmark)

Simonsen, L; Bülow, J; Astrup, A

1990-01-01

The effect of a carbohydrate-rich meal on subcutaneous adipose tissue blood flow was studied with and without continuous i.v. infusion of propranolol in healthy volunteers. The subcutaneous adipose tissue blood flow was measured with the 133Xe washout method in three different locations......: the forearm, the thigh and the abdomen. The subjects were given a meal consisting of white bread, jam, honey and apple juice (about 2300 kJ). The meal induced a twofold increase in blood flow in the examined tissues. Propranolol abolished the flow increase in the thigh and the abdomen and reduced...

Tolerability of continuous subcutaneous octreotide used in combination with other drugs.

Science.gov (United States)

Mercadante, S

1995-01-01

Continuous subcutaneous infusion of octreotide combined with other drugs has proved to be useful in some circumstances in palliative care setting when theoral route is no longer available. Forty-four patients were administered octreotide alone or in combination with other drugs in the same syringe driver for symptom control in advanced cancer patients. Good tolerability and compatibility were observed without visual drug precipitation for a period of 48 hours at room temperature, the standard clinical situation in patients' homes. Such a combination of drugs administered by the subcutaneous route makes possible the adequate control of symptoms in the final days of life.

Effect of mass-transport limitations on the performance of a packed bed membrane reactor for partial oxidations. Intraparticle mass transport

NARCIS (Netherlands)

Sint Annaland, van M.; Kurten, U.; Kuipers, J.A.M.

2007-01-01

For partial oxidation systems, where the reaction order in oxygen of the formation rate of the target product is smaller than the reaction order in oxygen of the consecutive reaction rate toward the waste product, a packed bed membrane reactor can be applied to distributively dose oxygen along the

Effect of Mass-Transport Limitations on the Performance of a Packed Bed Membrane Reactor for Partial Oxidations. Intraparticle Mass Transport

NARCIS (Netherlands)

van Sint Annaland, M.; Kurten, U.; Kuipers, J.A.M.

2007-01-01

For partial oxidation systems, where the reaction order in oxygen of the formation rate of the target product is smaller than the reaction order in oxygen of the consecutive reaction rate toward the waste product, a packed bed membrane reactor can be applied to distributively dose oxygen along the

The Ratio of Partial Pressure Arterial Oxygen and Fraction of Inspired Oxygen 1 Day After Acute Respiratory Distress Syndrome Onset Can Predict the Outcomes of Involving Patients.

Science.gov (United States)

Lai, Chih-Cheng; Sung, Mei-I; Liu, Hsiao-Hua; Chen, Chin-Ming; Chiang, Shyh-Ren; Liu, Wei-Lun; Chao, Chien-Ming; Ho, Chung-Han; Weng, Shih-Feng; Hsing, Shu-Chen; Cheng, Kuo-Chen

2016-04-01

The initial hypoxemic level of acute respiratory distress syndrome (ARDS) defined according to Berlin definition might not be the optimal predictor for prognosis. We aimed to determine the predictive validity of the stabilized ratio of partial pressure arterial oxygen and fraction of inspired oxygen (PaO2/FiO2 ratio) following standard ventilator setting in the prognosis of patients with ARDS.This prospective observational study was conducted in a single tertiary medical center in Taiwan and compared the stabilized PaO2/FiO2 ratio (Day 1) following standard ventilator settings and the PaO2/FiO2 ratio on the day patients met ARDS Berlin criteria (Day 0). Patients admitted to intensive care units and in accordance with the Berlin criteria for ARDS were collected between December 1, 2012 and May 31, 2015. Main outcome was 28-day mortality. Arterial blood gas and ventilator setting on Days 0 and 1 were obtained.A total of 238 patients met the Berlin criteria for ARDS were enrolled, and they were classified as mild (n = 50), moderate (n = 125), and severe (n = 63) ARDS, respectively. Twelve (5%) patients who originally were classified as ARDS did not continually meet the Berlin definition, and a total of 134 (56%) patients had the changes regarding the severity of ARDS from Day 0 to Day 1. The 28-day mortality rate was 49.1%, and multivariate analysis identified age, PaO2/FiO2 on Day 1, number of organ failures, and positive fluid balance within 5 days as significant risk factors of death. Moreover, the area under receiver-operating curve for mortality prediction using PaO2/FiO2 on Day 1 was significant higher than that on Day 0 (P = 0.016).PaO2/FiO2 ratio on Day 1 after applying mechanical ventilator is a better predictor of outcomes in patients with ARDS than those on Day 0.

In vivo detection of hemoglobin oxygen saturation and carboxyhemoglobin saturation with multiwavelength photoacoustic microscopy.

Science.gov (United States)

Chen, Zhongjiang; Yang, Sihua; Xing, Da

2012-08-15

A method for noninvasively detecting hemoglobin oxygen saturation (SO2) and carboxyhemoglobin saturation (SCO) in subcutaneous microvasculature with multiwavelength photoacoustic microscopy is presented. Blood samples mixed with different concentrations of carboxyhemoglobin were used to test the feasibility and accuracy of photoacoustic microscopy compared with the blood-gas analyzer. Moreover, fixed-point detection of SO2 and SCO in mouse ear was obtained, and the changes from normoxia to carbon monoxide hypoxia were dynamically monitored in vivo. Experimental results demonstrate that multiwavelength photoacoustic microscopy can detect SO2 and SCO, which has future potential clinical applications.

Treatment with subcutaneous and transdermal fentanyl: results from a population pharmacokinetic study in cancer patients

NARCIS (Netherlands)

Oosten, A.W.; Abrantes, J.A.; Jonsson, S.; Bruijn, P. de; Kuip, E.J.M.; Falcao, A.; Rijt, C.C. van der; Mathijssen, R.H.

2016-01-01

PURPOSE: Transdermal fentanyl is effective for the treatment of moderate to severe cancer-related pain but is unsuitable for fast titration. In this setting, continuous subcutaneous fentanyl may be used. As data on the pharmacokinetics of continuous subcutaneous fentanyl are lacking, we studied the

Tailoring properties of reduced graphene oxide by oxygen plasma treatment

Science.gov (United States)

Kondratowicz, Izabela; Nadolska, Małgorzata; Şahin, Samet; Łapiński, Marcin; Prześniak-Welenc, Marta; Sawczak, Mirosław; Yu, Eileen H.; Sadowski, Wojciech; Żelechowska, Kamila

2018-05-01

We report an easily controllable, eco-friendly method for tailoring the properties of reduced graphene oxide (rGO) by means of oxygen plasma. The effect of oxygen plasma treatment time (1, 5 and 10 min) on the surface properties of rGO was evaluated. Physicochemical characterization using microscopic, spectroscopic and thermal techniques was performed. The results revealed that different oxygen-containing groups (e.g. carboxyl, hydroxyl) were introduced on the rGO surface enhancing its wettability. Furthermore, upon longer treatment time, other functionalities were created (e.g. quinones, lactones). Moreover, external surface of rGO was partially etched resulting in an increase of the material surface area and porosity. Finally, the oxygen plasma-treated rGO electrodes with bilirubin oxidase were tested for oxygen reduction reaction. The study showed that rGO treated for 10 min exhibited twofold higher current density than untreated rGO. The oxygen plasma treatment may improve the enzyme adsorption on rGO electrodes by introduction of oxygen moieties and increasing the porosity.

Differential Activation of Peritoneal Cells by Subcutaneous Treatment of Rats with Cryptococcal Antigens▿

OpenAIRE

Baronetti, José L.; Chiapello, Laura S.; Garro, Ana P.; Masih, Diana T.

2009-01-01

Previous studies in our laboratory have shown that the subcutaneous pretreatment of rats with heat-killed cells (HKC) of Cryptococcus neoformans emulsified in complete Freund adjuvant (CFA) promotes protective immunity against an intraperitoneal challenge with C. neoformans. In contrast, subcutaneous treatment with the capsular polysaccharide (PSC) emulsified in CFA exacerbates the cryptococcal infection. The purpose of this study was to analyze the mechanisms involved in these phenomena. Adh...

The influence of a hyperbaric environment and increased oxygen partial pressure on the corrosion of dental alloys.

Science.gov (United States)

Mehl, Christian; Heblich, Frank; Lenz, Rudolf; Ludwig, Klaus; Kern, Matthias

2011-09-01

The purpose of this in-vitro study was to determine whether there is a correlation between a hyperbaric environment or increased oxygen partial pressure and the corrosion of dental alloys used for dental restorations in divers. Samples of three commercially available dental alloys (palladium-based, reduced-gold-content and high-gold-content) were tested in the DIN EN ISO 1562 static immersion test and the amount of dissolved ions measured by atomic absorption spectrometry. The specimens were exposed to one of the following three conditions: normobaric and normoxic conditions (PO2 21 kPa); 608 kPa (6 bar, PO2 127 kPa) pressurised air in a pressure chamber or 506 kPa (5 bar, PO2 304 kPa) pressurised nitrox in a pressure chamber. None of the exposures suggested a correlation between increased ion solubility as a measure of corrosion and increased ambient pressure of the three alloys. The reduced-gold-content alloy released zinc ions at twice the weekly recommended dose. When the palladium-based alloy was exposed to a hyperbaric or hyperbaric/hyperoxic environment, ion solubility increased only slightly for gallium and silver. Within the limited sample size of the current study it can be concluded that hyperbaric and/or hyperoxic conditions do not seem to be a risk for increased corrosion for any of the three tested alloys.

Effect of oxygen partial pressure on the structural and optical properties of dc sputtered ITO thin films

International Nuclear Information System (INIS)

Kerkache, L.; Layadi, A.; Mosser, A.

2009-01-01

We present results on the effect of the partial pressure of oxygen (ppo) on the structural and optical properties of tin-doped indium oxide, In 2 O 3 :Sn (ITO), thin films deposited on glass substrates by reactive dc diode sputtering. The deposition rate decreases with increasing ppo. The ppo did not affect the chemical composition of the ITO films as inferred from X-ray photoemission spectroscopy (XPS). From X-ray diffraction, we find out that the samples have crystalline structure in the ppo range 2 x 10 -4 to 6 x 10 -4 mbar and are amorphous outside this range. These samples have a preferred orientation for ppo between 2 x 10 -4 and 4.5 x 10 -4 mbar, but as the ppo increased beyond 4.7 x 10 -4 mbar, the texture dominates. This change occurs for the same substrate temperature (about 130 deg. C). The grain size decreases as the ppo increases. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) have been used to investigate the surface roughness and the morphology of these samples. The optical transmission is greater than 90% in the visible region and does depend on the ppo. The refractive index n values are found to be in the 1.68-1.86 range. The energy gap values are between 3.1 and 3.5 eV.

Subcutaneous fat necrosis of the newborn.

Science.gov (United States)

Oswalt, G C; Montes, L F; Cassady, G

1978-08-01

Subcutaneous fat necrosis of the newborn (SFNN) developed in a 1-week-old black boy. His mother had received numerous medications for eclampsia. Birth was by Caesarean section and complicated by meconium aspiration. There were numerous nodules over the back, buttocks and extremities that yielded a caseous-like material. Microscopically, these nodules showed crystallization and necrosis of the fat. Hypoglycemia, pneumonia, oliguria, thrombocytopenia, seizures and urinary infection were associated with the cutaneous problem and led to a fatal outcome 2 weeks after birth.

Cervicofacial subcutaneous air emphysema after dental extraction.

Science.gov (United States)

Reznick, J B; Ardary, W C

1990-04-01

A patient was seen by a general practitioner for surgical removal of his third molar. A standard high-speed handpiece was used to remove the tooth. During the procedure, subcutaneous emphysema developed. Later the same day, the patient's swelling increased and his airway was compromised. The patient's condition, the differential diagnosis, etiological factors, and treatment of this condition are all detailed within this clinical report.

Tensile properties of V-Cr-Ti alloys after exposure in helium and low-partial-pressure oxygen environments

Energy Technology Data Exchange (ETDEWEB)

Natesan, K.; Soppet, W.K. [Argonne National Lab., IL (United States)

1997-04-01

A test program is in progress to evaluate the effect of oxygen at low pO{sub 2} on the tensile properties of V-(4-5)wt% Cr-(4-5)wt% Ti alloys. Some of the tensile specimens were precharged with oxygen at low pO{sub 2} at 500{degrees}C and reannealed in vacuum at 500{degrees}C in environments with various pO{sub 2} levels and subsequently tensile tested at room temperature. The preliminary results indicate that both approaches are appropriate for evaluating the effect of oxygen uptake on the tensile properties of the alloys. The data showed that in the relatively short-time tests conducted thus far, the maximum engineering stress slightly increased after oxygen exposure but the uniform and total elongation values exhibited significant decrease after exposure in oxygen-containing environments. The data for a specimen exposed to a helium environment were similar to those obtained in low pO{sub 2} environments.

Tensile properties of V-Cr-Ti alloys after exposure in helium and low-partial-pressure oxygen environments

International Nuclear Information System (INIS)

Natesan, K.; Soppet, W.K.

1997-01-01

A test program is in progress to evaluate the effect of oxygen at low pO 2 on the tensile properties of V-(4-5)wt% Cr-(4-5)wt% Ti alloys. Some of the tensile specimens were precharged with oxygen at low pO 2 at 500 degrees C and reannealed in vacuum at 500 degrees C in environments with various pO 2 levels and subsequently tensile tested at room temperature. The preliminary results indicate that both approaches are appropriate for evaluating the effect of oxygen uptake on the tensile properties of the alloys. The data showed that in the relatively short-time tests conducted thus far, the maximum engineering stress slightly increased after oxygen exposure but the uniform and total elongation values exhibited significant decrease after exposure in oxygen-containing environments. The data for a specimen exposed to a helium environment were similar to those obtained in low pO 2 environments

Chordoma with postoperative subcutaneous implantation and meningeal dissemination: MRI

International Nuclear Information System (INIS)

Kinoshita, T.; Okudera, T.; Shimosegawa, E.; Hatazawa, J.; Yoshida, Y.; Yasui, N.; Ogawa, T.

2001-01-01

Chordomas are histologically benign tumours which are locally invasive. We present an unusual case of recurrent chordoma with subcutaneous implantation and widespread meningeal dissemination after surgery. Contrast-enhanced MRI was useful for determining the extent of the tumour. (orig.)

Effect of weight, sex and hunting period on fatty acid composition of intramuscular and subcutaneous fat from wild boar

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Artūras Šiukščius

2012-04-01

Full Text Available The study examined the influence of weight, sex and month of hunting on the fatty acid composition of intramuscular and subcutaneous fat from 49 free ranging wild boars hunted in Lithuania during the winter season. A total number of 27 and 25 fatty acids were identified in the intramuscular fat and subcutaneous tissue of wild boars, respectively. The weight of the wild boar had mainly affected only the levels of separate fatty acids both in the intramuscular and subcutaneous fat. Higher levels of saturated fatty acids (SFA were found in the intramuscular and subcutaneous fat of males compared with females. The effect of both weight and sex on the levels of fatty acids was higher in the subcutaneous fat than in the intramuscular fat. Weight, sex and hunting month had no effect on PUFA/SFA and n-6 PUFA/n-3 PUFA ratios in the intramuscular and subcutaneous fat. The atherogenic (AI and thrombogenic (TI indexes and hypocholesterolemic/hypercholesterolemic ratio in subcutaneous fat were more favorable in females compared with males and in the January hunting season than in November and December.

Ammonium excretion and oxygen respiration of tropical copepods and euphausiids exposed to oxygen minimum zone conditions

Science.gov (United States)

Kiko, R.; Hauss, H.; Buchholz, F.; Melzner, F.

2015-10-01

Calanoid copepods and euphausiids are key components of marine zooplankton communities worldwide. Most euphausiids and several copepod species perform diel vertical migrations (DVMs) that contribute to the export of particulate and dissolved matter to midwater depths. In vast areas of the global ocean, and in particular in the eastern tropical Atlantic and Pacific, the daytime distribution depth of many migrating organisms corresponds to the core of the oxygen minimum zone (OMZ). At depth, the animals experience reduced temperature and oxygen partial pressure (pO2) and an increased carbon dioxide partial pressure (pCO2) compared to their near-surface nighttime habitat. Although it is well known that low oxygen levels can inhibit respiratory activity, the respiration response of tropical copepods and euphausiids to relevant pCO2, pO2 and temperature conditions remains poorly parameterized. Further, the regulation of ammonium excretion at OMZ conditions is generally not well understood. It was recently estimated that DVM-mediated ammonium supply considerably fuels bacterial anaerobic ammonium oxidation - a major loss process for fixed nitrogen in the ocean. These estimates were based on the implicit assumption that hypoxia or anoxia in combination with hypercapnia (elevated pCO2) does not result in a downregulation of ammonium excretion. Here we show that exposure to OMZ conditions can result in strong depression of respiration and ammonium excretion in calanoid copepods and euphausiids from the Eastern Tropical North Atlantic and the Eastern Tropical South Pacific. These physiological responses need to be taken into account when estimating DVM-mediated fluxes of carbon and nitrogen into OMZs.

The first reported case of canine subcutaneous Cryptococcus flavescens infection.

Science.gov (United States)

Kano, Rui; Ishida, Rinei; Nakane, Shinsuke; Sekiguchi, Maiko; Hasegawa, Atsuhiko; Kamata, Hiroshi

2012-03-01

This report describes the first documented case of subcutaneous infection due to Cryptococcus flavescens in a dog. The chief symptoms of the patient dog were abscessed lesions on the dorsal muzzle, right eyelid, and lower jaw. Biopsy specimens from the lesions on the dorsal muzzle and lower jaw showed pyogranulomatous inflammation with numerous yeast cells. The patient dog was diagnosed with a subcutaneous fungal infection and orally received 5 mg/kg itraconazole once a day for 2 months, the abscesses disappeared. After 1 month at the end of treatment, the skin lesions did not redevelop. Isolates from the biopsy specimens were identified as C. flavescens by molecular analysis as well as morphologic and biochemical examination, indicating that C. flavescens is a potential canine pathogen.

Subcutaneous emphysema during root canal therapy: endodontic accident by sodium hypoclorite.

Science.gov (United States)

Tenore, Gianluca; Palaia, Gaspare; Ciolfi, Chiara; Mohsen, Mohamed; Battisti, Andrea; Romeo, Umberto

2017-01-01

Cervicofacial subcutaneous emphysema is defined as the abnormal introduction of air in the subcutaneous tissues of the head and neck. It is mainly caused by trauma, head and neck surgery, general anesthesia, and coughing or habitual performance of Valsalva manoeuvre. The occurrence of subcutaneous emphysema after dental treatment is rare, and diffusion of gas into the mediastinum is much rarer, especially when the procedure is a nonsurgical treatment. Presented here is a case of subcutaneous emphysema that occurred after sodium hypochlorite irrigation during endodontic treatment, and the description of its etiologies and prevention during nonsurgical endodontic treatment. Endodontic success can be essentially achieved via good debridement of a root canal, and an ideal endodontic irrigant is effective in removing the smear layer, opening the dentinal tubules, and producing a clean surface for closer obturation. A 60-years-old woman had an abnormal swelling and pain during an endodontic treatment accompanied by her dentist to the emergency room and was referred to our observation for complaining of severe pain, ecchymosis and severe swelling on the left side of her face. The aforementioned symptoms appeared after sodium hypochlorite irrigation and aggressive use of air spray for drying the root canal during the endodontic treatment of the upper left lateral incisor. An extrusion during an inappropriate endodontic treatment may occasionally be reported and can cause tissue damage. NaOCl is one of the best and most commonly used irrigating solutions because of its efficacy, but it can also negatively affect the periapical tissues. Determining the correct working length, even when performing an intraoperative periapical radiograph and confirming the root canal integrity, could help avoid these kinds of accidents.

Subcutaneous adipose tissue classification

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A. Sbarbati

2010-11-01

Full Text Available The developments in the technologies based on the use of autologous adipose tissue attracted attention to minor depots as possible sampling areas. Some of those depots have never been studied in detail. The present study was performed on subcutaneous adipose depots sampled in different areas with the aim of explaining their morphology, particularly as far as regards stem niches. The results demonstrated that three different types of white adipose tissue (WAT can be differentiated on the basis of structural and ultrastructural features: deposit WAT (dWAT, structural WAT (sWAT and fibrous WAT (fWAT. dWAT can be found essentially in large fatty depots in the abdominal area (periumbilical. In the dWAT, cells are tightly packed and linked by a weak net of isolated collagen fibers. Collagenic components are very poor, cells are large and few blood vessels are present. The deep portion appears more fibrous then the superficial one. The microcirculation is formed by thin walled capillaries with rare stem niches. Reinforcement pericyte elements are rarely evident. The sWAT is more stromal; it is located in some areas in the limbs and in the hips. The stroma is fairly well represented, with a good vascularity and adequate staminality. Cells are wrapped by a basket of collagen fibers. The fatty depots of the knees and of the trochanteric areas have quite loose meshes. The fWAT has a noteworthy fibrous component and can be found in areas where a severe mechanic stress occurs. Adipocytes have an individual thick fibrous shell. In conclusion, the present study demonstrates evident differences among subcutaneous WAT deposits, thus suggesting that in regenerative procedures based on autologous adipose tissues the sampling area should not be randomly chosen, but it should be oriented by evidence based evaluations. The structural peculiarities of the sWAT, and particularly of its microcirculation, suggest that it could represent a privileged source for

Pharmacokinetics of nebulized and subcutaneously implanted terbinafine in cottonmouths (Agkistrodon piscivorus).

Science.gov (United States)

Kane, L P; Allender, M C; Archer, G; Leister, K; Rzadkowska, M; Boers, K; Souza, M; Cox, S

2017-10-01

Ophidiomyces ophiodiicola, the causative agent of snake fungal disease, is proposed as a serious threat to the conservation of several snake populations. The objective of this study was to determine the pharmacokinetic parameters of terbinafine administered through nebulization and a sustained subcutaneous implant as potential treatments of Ophidiomyces in reptiles. Seven adult cottonmouths (Agkistrodon piscivorus) were used in single-dose trials. Each snake was nebulized with terbinafine (2 mg/ml) for 30 min and had blood collected before nebulization and up to 12 hr after nebulization. Following a 5-month washout, the same snakes were administered a subcutaneous implant containing 24.5 mg terbinafine; blood was collected at baseline, 1 day postimplant placement, and then once weekly for 9 weeks. Plasma for both studies was analyzed by high-performance liquid chromatography. The mean plasma concentrations of nebulized terbinafine peaked between 0.5 and 4 hr. The subcutaneously implanted terbinafine reached therapeutic concentrations on day 1 and maintained therapeutic for over 6 weeks. These methods and doses are recommended as potential treatment options for snake fungal disease in reptiles. © 2017 John Wiley & Sons Ltd.

The Subcutaneous Implantable Cardioverter-Defibrillator: A Practical Review and Real-World Use and Application

Directory of Open Access Journals (Sweden)

Mark E. Panna Jr, MD, FACC, FHRS

2016-02-01

Full Text Available The subcutaneous implantable cardioverter-defibrillator (ICD is a novel technology using a subcutaneous (extrathoracic system for treatment of potential lethal ventricular arrhythmias. It avoids many of the risks of transvenous ICD implantation. It may be considered in patients having an ICD indication who do not have a pacing and/or cardiac resynchronization therapy indication, and who are unlikely to benefit from antitachycardia pacing therapy. We review patient selection, system components, the implantation technique, and screening considerations for subcutaneous ICD implantation. Its uses in specific patient populations, including children, patients with congenital heart disease, hypertrophic cardiomyopathy, or end-stage renal disease, and patients with preexisting pacemakers, are highlighted. Areas of future investigation are reviewed, including potential use with leadless pacing and magnetic resonance imaging.

Associations of Infant Subcutaneous Fat Mass with Total and Abdominal Fat Mass at School-Age: The Generation R Study.

Science.gov (United States)

Santos, Susana; Gaillard, Romy; Oliveira, Andreia; Barros, Henrique; Abrahamse-Berkeveld, Marieke; van der Beek, Eline M; Hofman, Albert; Jaddoe, Vincent W V

2016-09-01

Skinfold thickness enables the measurement of overall and regional subcutaneous fatness in infancy and may be associated with total and abdominal body fat in later childhood. We examined the associations of subcutaneous fat in infancy with total and abdominal fat at school-age. In a population-based prospective cohort study among 821 children, we calculated total subcutaneous fat (sum of biceps, triceps, suprailiacal, and subscapular skinfold thicknesses) and central-to-total subcutaneous fat ratio (sum of suprailiacal and subscapular skinfold thicknesses/total subcutaneous fat) at 1.5 and 24 months. At 6 years, we measured fat mass index (total fat/height(3) ), central-to-total fat ratio (trunk fat/total fat), and android-to-gynoid fat ratio (android fat/gynoid fat) by dual-energy X-ray absorptiometry and preperitoneal fat mass area by abdominal ultrasound. Central-to-total subcutaneous fat ratio at 1.5 months was positively associated with fat mass index and central-to-total fat ratio at 6 years, whereas both total and central-to-total subcutaneous fat ratio at 24 months were positively associated with all childhood adiposity measures. A 1-standard-deviation scores higher total subcutaneous fat at 24 months was associated with an increased risk of childhood overweight (odds ratio 1.70, 95% confidence interval 1.36, 2.12). These associations were weaker than those for body mass index and stronger among girls than boys. Subcutaneous fat in infancy is positively associated with total and abdominal fat at school-age. Our results also suggest that skinfold thicknesses add little value to estimate later body fat, as compared with body mass index. © 2016 John Wiley & Sons Ltd.

Surgical Management of Gynecomastia: Subcutaneous Mastectomy and Liposuction.

Science.gov (United States)

Kim, Dae Hwa; Byun, Il Hwan; Lee, Won Jai; Rah, Dong Kyun; Kim, Ji Ye; Lee, Dong Won

2016-12-01

The treatment of gynecomastia depends on multiple factors, and the best modality is controversial. In this study, we aimed to determine the best management approach by comparing outcomes of two groups of patients with gynecomastia who received subcutaneous mastectomy combined with liposuction and liposuction only. We conducted a retrospective analysis of 64 patients who underwent surgery for gynecomastia. We divided the patients into two groups: group A, patients who underwent liposuction only; and group B, patients who underwent liposuction and subcutaneous mastectomy. The serial photographs of all patients were clinically evaluated with respect to size, shape, scarring, and overall outcome by three plastic surgeons, and patient satisfaction was surveyed with regard to palpable lumps, size, shape, scarring, and overall outcome. Of the 64 subjects, 16 received liposuction only, and 48 received the combination procedure. A total of 125 breasts were involved. The doctors' scores for size and overall outcome were significantly better in the combination group, whereas scarring was better in the liposuction-only group. Similarly, patient satisfaction regarding size was significantly higher in the combination group, and satisfaction regarding scarring was significantly higher in the liposuction-only group. The scores for scarring in the combination treatment group were acceptable. Our study shows that combination treatment with liposuction and subcutaneous mastectomy results in satisfactory outcomes, including the extent of scarring. We conclude that this combination treatment should be recommended as the standard surgical treatment for gynecomastia and can provide excellent results in cases where glandular tissue needs to be removed. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www

Kinetic bottlenecks to chemical exchange rates for deep-sea animals - Part 1: Oxygen

Science.gov (United States)

Hofmann, A. F.; Peltzer, E. T.; Brewer, P. G.

2012-10-01

Ocean warming will reduce dissolved oxygen concentrations which can pose challenges to marine life. Oxygen limits are traditionally reported simply as a static concentration thresholds with no temperature, pressure or flow rate dependency. Here we treat the oceanic oxygen supply potential for heterotrophic consumption as a dynamic molecular exchange problem analogous to familiar gas exchange processes at the sea surface. A combination of the purely physico-chemical oceanic properties temperature, hydrostatic pressure, and oxygen concentration defines the ability of the ocean to supply oxygen to any given animal. This general oceanic oxygen supply potential is modulated by animal specific properties such as the diffusive boundary layer thickness to define and limit maximal oxygen supply rates. Here we combine all these properties into formal, mechanistic equations defining novel oceanic properties that subsume various relevant classical oceanographic parameters to better visualize, map, comprehend, and predict the impact of ocean deoxygenation on aerobic life. By explicitly including temperature and hydrostatic pressure into our quantities, various ocean regions ranging from the cold deep-sea to warm, coastal seas can be compared. We define purely physico-chemical quantities to describe the oceanic oxygen supply potential, but also quantities that contain organism-specific properties which in a most generalized way describe general concepts and dependencies. We apply these novel quantities to example oceanic profiles around the world and find that temperature and pressure dependencies of diffusion and partial pressure create zones of greatest physical constriction on oxygen supply typically at around 1000 m depth, which coincides with oxygen concentration minimum zones. In these zones, which comprise the bulk of the world ocean, ocean warming and deoxygenation have a clear negative effect for aerobic life. In some shallow and warm waters the enhanced diffusion and

Diffusion and Monod kinetics model to determine in vivo human corneal oxygen-consumption rate during soft contact lens wear

Directory of Open Access Journals (Sweden)

Luis F. Del Castillo

2015-01-01

Conclusion: Present results are relevant for the calculation on the partial pressure of oxygen, available at different depths into the corneal tissue behind contact lenses of different oxygen transmissibility.

Energy Harvesting by Subcutaneous Solar Cells: A Long-Term Study on Achievable Energy Output.

Science.gov (United States)

Bereuter, L; Williner, S; Pianezzi, F; Bissig, B; Buecheler, S; Burger, J; Vogel, R; Zurbuchen, A; Haeberlin, A

2017-05-01

Active electronic implants are powered by primary batteries, which induces the necessity of implant replacement after battery depletion. This causes repeated interventions in a patients' life, which bears the risk of complications and is costly. By using energy harvesting devices to power the implant, device replacements may be avoided and the device size may be reduced dramatically. Recently, several groups presented prototypes of implants powered by subcutaneous solar cells. However, data about the expected real-life power output of subcutaneously implanted solar cells was lacking so far. In this study, we report the first real-life validation data of energy harvesting by subcutaneous solar cells. Portable light measurement devices that feature solar cells (cell area = 3.6 cm 2 ) and continuously measure a subcutaneous solar cell's output power were built. The measurement devices were worn by volunteers in their daily routine in summer, autumn and winter. In addition to the measured output power, influences such as season, weather and human activity were analyzed. The obtained mean power over the whole study period was 67 µW (=19 µW cm -2 ), which is sufficient to power e.g. a cardiac pacemaker.

Space Shuttle Orbiter oxygen partial pressure sensing and control system improvements

Science.gov (United States)

Frampton, Robert F.; Hoy, Dennis M.; Kelly, Kevin J.; Walleshauser, James J.

1992-01-01

A program aimed at developing a new PPO2 oxygen sensor and a replacement amplifier for the Space Shuttle Orbiter is described. Experimental design methodologies used in the test and modeling process made it possible to enhance the effectiveness of the program and to reduce its cost. Significant cost savings are due to the increased lifetime of the basic sensor cell, the maximization of useful sensor life through an increased amplifier gain adjustment capability, the use of streamlined production processes for the manufacture of the assemblies, and the refurbishment capability of the replacement sensor.

High-temperature equilibrium study of the oxygen-site occupancy in YBa2Cu3O7-δ by positron annihilation

International Nuclear Information System (INIS)

Hermes, H.; Forster, M.; Schaefer, H.

1991-01-01

Measurements of the positron lifetime and the Doppler broadening of the annihilation γ line were performed on sintered YBa 2 Cu 3 O 7-δ specimens between ambient temperature and 1140 K at oxygen partial pressures, p O2 , between 10 2 and 10 5 Pa in order to study the atomic processes of changes of the oxygen content in thermal equilibrium. Above 680 K the positron lifetime increases with increasing temperature and decreasing oxygen partial pressure. It is found that the normalized positron annihilation rate λ 1 * depends exclusively on the oxygen deficiency δ and decreases linearly with increasing δ. Our results demonstrate that the positrons are annihilated predominantly on the sites of the Cu(1)-O(1) chains where the oxygen atoms are removed (oxygen-deficient sites), as suggested by theoretical studies. A simple atomistic model of oxygen exchange is confirmed by the experimentally observed variation of the positron annihilation rate with (p O2 ) -0.27

Oxygen Toxicity and Special Operations Forces Diving: Hidden and Dangerous

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Thijs T. Wingelaar

2017-07-01

Full Text Available In Special Operations Forces (SOF closed-circuit rebreathers with 100% oxygen are commonly utilized for covert diving operations. Exposure to high partial pressures of oxygen (PO2 could cause damage to the central nervous system (CNS and pulmonary system. Longer exposure time and higher PO2 leads to faster development of more serious pathology. Exposure to a PO2 above 1.4 ATA can cause CNS toxicity, leading to a wide range of neurologic complaints including convulsions. Pulmonary oxygen toxicity develops over time when exposed to a PO2 above 0.5 ATA and can lead to inflammation and fibrosis of lung tissue. Oxygen can also be toxic for the ocular system and may have systemic effects on the inflammatory system. Moreover, some of the effects of oxygen toxicity are irreversible. This paper describes the pathophysiology, epidemiology, signs and symptoms, risk factors and prediction models of oxygen toxicity, and their limitations on SOF diving.

Interplay of the influence of oxygen partial pressure and rf power on ...

Indian Academy of Sciences (India)

2017-07-25

Jul 25, 2017 ... extra heating) and low pressure p = 0.5 mTorr, varying the rf power density between P = 0.57 and 2.83 W cm−2 at different relative oxygen ... thin films are used as window layers in solar cells [1–3]. Sput- tering (especially rf ... defect density [11,12]. In the literature there are works reporting the effect of rf.

Physico-chemical Stability of MabThera Drug-product Solution for Subcutaneous Injection under in-use Conditions with Different Administration Materials.

Science.gov (United States)

Mueller, Claudia; Dietel, Elke; Heynen, Severin R; Nalenz, Heiko; Goldbach, Pierre; Mahler, Hanns-Christian; Schmidt, Johannes; Grauschopf, Ulla; Schoenhamnmer, Karin

2015-01-01

MabThera is an essential component of the standard-of-care regimens in the treatment of non-Hodgkin lymphoma and Chronic Lymphatic Leukemia. MabThera for subcutaneous injection is a novel line extension that has been approved by the European Medicines Agency for the treatment of patients with follicular lymphoma and diffuse large B-cell lymphoma. This study aimed to evaluate in-use stability data of MabThera subcutaneous drug-product solution in single-use syringes for subcutaneous administration according to the European Medicines Agency guideline. The drug-product solution was exposed to material contact surfaces of five different administration setups commonly used in subcutaneous drug delivery. MabThera subcutaneous was transferred under aseptic conditions into polypropylene and polycarbonate syringes and stored for 1, 2, and 4 weeks at 2°C to 8°C followed by 24 hours at 30°C. After storage, subcutaneous administration was simulated and MabThera subcutaneous drug-product solution quality attributes were evaluated by using compendial physico-chemical tests, as well as suitable and validated molecule- and formulation-specific analytical methods. MabThera subcutaneous vials were treated and analyzed in parallel. The physico-chemical results of MabThera subcutaneous in the different setups were comparable to the control for all timepoints. No change in drug-product quality after storage and simulated administration was found compared to the control. However, since single-dose products do not contain preservatives, microbial contamination and growth needs to be avoided and product sterility needs to be ensured. The results showed that MabThera subcutaneous remains compatible and stable, from a physico-chemical perspective, for up to 4 weeks at 2°C to 8°C followed by 24 hours at 30°C with the contact materials tested in this study. In order to avoid and minimize microbial growth, MabThera subcutaneous should be used immediately after removal from the original

Catalytic reforming of methane to syngas in an oxygen-permeative membrane reactor

Energy Technology Data Exchange (ETDEWEB)

Urano, Takeshi; Kubo, Keiko; Saito, Tomoyuki; Hitomi, Atsushi, E-mail: turano@jp.tdk.com [Materials and Process Development Center, TDK Corporation 570-2, Matsugashita, Minamihatori, Narita, Chiba 286-8588 (Japan)

2011-05-15

For fuel cell applications, partial oxidative reforming of methane to syngas, hydrogen and carbon monoxide, was performed via a dense oxygen-permeative ceramic membrane composed by both ionic and electronic conductive materials. The modification of Ni-based catalyst by noble metals was investigated to increase oxygen permeation flux and decrease carbon deposition during reforming reaction. The role of each component in catalyst was also discussed.

Prolonged Survival of Subcutaneous Allogeneic Islet Graft by Donor Chimerism without Immunosuppressive Treatment

Directory of Open Access Journals (Sweden)

Brend Ray-Sea Hsu

2017-01-01

Full Text Available The aim of this study was to investigate whether tolerance-induced protection of islets in the renal subcapsular space can also prevent subcutaneous allogeneic islets from being rejected. We used bone marrow stem cells from C57BL/6 (H2b mice to construct donor chimerism in conditioned diabetic BALB/c (H2d mice and investigated the effect of donor chimerism on engraftment and survival of subcutaneously transplanted allogeneic islets in streptozotocin-induced diabetic mice. We also studied the anti-inflammatory effect of mesenchymal stem cell on islet engraftment. Full but not low-grade or no donor chimerism was associated with successful engraftment of allogeneic islets and restoration of normoglycemia in the treated diabetic mice. The temporary hyperglycemia was 11 ± 1 versus 19 ± 5 days (p<0.05 for the mice with full donor chimerism with transplanted islets in the renal subcapsular space versus the subcutaneous space, respectively. Cotransplantation of mesenchymal stem cell did not enhance alloislet engraftment. Full multilineage donor chimerism was associated with a higher transient expansion of CD11b+ and Gr-1+ myeloid progenitor cells and effector memory CD4 and CD8 T cells. In conclusion, full donor chimerism protected both renal subcapsular and subcutaneous allogeneic islets in this rodent transplantation model.

Electrochemical extraction of oxygen using PEM electrolysis technology

Directory of Open Access Journals (Sweden)

BOULBABA ELADEB

2012-11-01

Full Text Available Electrochemical extraction of oxygen from air can be carried out by chemical reduction of oxygen at the cathode and simultaneous oxygen evolution by water anode oxidation. The present investigation deals with the use of an electrolysis cell of PEM technology for this purpose. A dedicated 25 cm2 cell provided with a commercial water electrolysis MEA and titanium grooved plates has been designed for continuous operation at pressures close to the ambient level. The MEA consisted of a Nafion 117 membrane sandwiched between a Pt/C cathode and a non-supported Pt-Ir anode. Oxygen partial consumption in long-term runs was evaluated by analysis of the outlet air by gas chromatography, depending on the cell voltage - or the current density - and the excess in air oxygen fed to the cathode. Runs over more 50 hours indicated the relative stability of the components used for current densities ranging from 0.1 to 0.2 A cm-2 with high efficiency of oxygen reduction. Higher current density could be envisaged with more efficient MEA’s, exhibiting lower overpotentials for oxygen evolution to avoid too significant degradation of the anode material and the membrane. Interpretation of the data has been carried out by calculation of the cathode current efficiency.

Cutaneous and subcutaneous Ewing's sarcoma: an indolent disease

International Nuclear Information System (INIS)

Chow, Edward; Merchant, Thomas E.; Pappo, Alberto; Jenkins, Jesse J.; Shah, Amit B.; Kun, Larry E.

2000-01-01

Purpose: The occurrence of extraosseous Ewing's sarcoma (ES) in deep soft tissues has been well described, but cases in which this tumor occurs in a primary cutaneous or subcutaneous site have rarely been reported. The superficial variant may be less aggressive than are the more common bony and deep soft tissue counterparts with an apparently favorable outcome. A retrospective review of patients with cutaneous or subcutaneous ES was conducted to analyze outcome and patterns of failure. Methods and Materials: Between July 1985 and March 1997, 14 patients with cutaneous or subcutaneous ES were treated at St. Jude Children's Research Hospital. The median age at presentation was 16 years (range 7-21 years). Anatomic locations included trunk and pelvis (7), upper or lower extremity (4), and head and neck (3). The median size of the lesion was 3 cm (range, 1-12 cm). Thirteen had definitive surgical resections, and one had biopsy of the mass at the time of referral. They were enrolled on institutional (12) or cooperative group (2) protocols. All patients received chemotherapy, composed of vincristine, doxorubicin, cyclophosphamide, ifosfamide, etoposide, and dactinomycin. Patients on institutional protocols received radiation (36 Gy) to the operative bed (150-180 cGy/fraction/day). Postoperative radiotherapy was omitted for 2 patients who had complete resection on the cooperative group study. Results: No patients had metastatic disease at presentation. Thirteen patients had wide local excision of the primary tumors prior to enrollment on chemotherapy; surgical margins were negative (10), microscopically positive (2), and indeterminate (1). Eleven patients received radiotherapy to the tumor bed; 2 with clear surgical margins were treated without irradiation. The patient who had biopsy only received induction chemotherapy followed by definitive surgical resection and postoperative radiotherapy. The median follow-up was 77 months (range 17-111 months). None of the patients

Free Fatty Acid Storage in Human Visceral and Subcutaneous Adipose Tissue

Science.gov (United States)

Ali, Asem H.; Koutsari, Christina; Mundi, Manpreet; Stegall, Mark D.; Heimbach, Julie K.; Taler, Sandra J.; Nygren, Jonas; Thorell, Anders; Bogachus, Lindsey D.; Turcotte, Lorraine P.; Bernlohr, David; Jensen, Michael D.

2011-01-01

OBJECTIVE Because direct adipose tissue free fatty acid (FFA) storage may contribute to body fat distribution, we measured FFA (palmitate) storage rates and fatty acid (FA) storage enzymes/proteins in omental and abdominal subcutaneous fat. RESEARCH DESIGN AND METHODS Elective surgery patients received a bolus of [1-14C]palmitate followed by omental and abdominal subcutaneous fat biopsies to measure direct FFA storage. Long chain acyl-CoA synthetase (ACS) and diacylglycerol acyltransferase activities, CD36, fatty acid-binding protein, and fatty acid transport protein 1 were measured. RESULTS Palmitate tracer storage (dpm/g adipose lipid) and calculated palmitate storage rates were greater in omental than abdominal subcutaneous fat in women (1.2 ± 0.8 vs. 0.7 ± 0.4 μmol ⋅ kg adipose lipid−1 ⋅ min−1, P = 0.005) and men (0.7 ± 0.2 vs. 0.2 ± 0.1, P < 0.001), and both were greater in women than men (P < 0.0001). Abdominal subcutaneous adipose tissue palmitate storage rates correlated with ACS activity (women: r = 0.66, P = 0.001; men: r = 0.70, P = 0.007); in men, CD36 was also independently related to palmitate storage rates. The content/activity of FA storage enzymes/proteins in omental fat was dramatically lower in those with more visceral fat. In women, only omental palmitate storage rates were correlated (r = 0.54, P = 0.03) with ACS activity. CONCLUSIONS Some adipocyte FA storage factors correlate with direct FFA storage, but sex differences in this process in visceral fat do not account for sex differences in visceral fatness. The reduced storage proteins in those with greater visceral fat suggest that the storage factors we measured are not a predominant cause of visceral adipose tissue accumulation. PMID:21810594

Microcosting Study of Rituximab Subcutaneous Injection Versus Intravenous Infusion

NARCIS (Netherlands)

Mihajloviç, Jovan; Bax, Pieter; van Breugel, Erwin; Blommestein, Hedwig M.; Hoogendoorn, Mels; Hospes, Wobbe; Postma, Maarten J.

Purpose: The goal of this study is to identify and compare all direct costs of intravenous and subcutaneous rituximab given to patients with diffuse large B-cell lymphoma in the Netherlands.  Methods: Using a prospective, observational, bottom-up microcosting study, we collected primary data on the

Four-Hour Dives with Exercise While Breathing Oxygen Partial Pressure of 1.3 ATM

National Research Council Canada - National Science Library

Shykoff, B

2006-01-01

.... Still, because the increased ventilatory demands and blood flow to the lungs during underwater exercise may cause pulmonary injury or may increase oxygen-induced injury over those ventilatory demands...

Oxygen dependency of germinating Brassica seeds

Science.gov (United States)

Park, Myoung Ryoul; Hasenstein, Karl H.

2016-02-01

Establishing plants in space, Moon or Mars requires adaptation to altered conditions, including reduced pressure and composition of atmospheres. To determine the oxygen requirements for seed germination, we imbibed Brassica rapa seeds under varying oxygen concentrations and profiled the transcription patterns of genes related to early metabolism such as starch degradation, glycolysis, and fermentation. We also analyzed the activity of lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH), and measured starch degradation. Partial oxygen pressure (pO2) greater than 10% resulted in normal germination (i.e., protrusion of radicle about 18 hours after imbibition) but lower pO2 delayed and reduced germination. Imbibition in an oxygen-free atmosphere for three days resulted in no germination but subsequent transfer to air initiated germination in 75% of the seeds and the root growth rate was transiently greater than in roots germinated under ambient pO2. In hypoxic seeds soluble sugars degraded faster but the content of starch after 24 h was higher than at ambient oxygen. Transcription of genes related to starch degradation, α-amylase (AMY) and Sucrose Synthase (SUS), was higher under ambient O2 than under hypoxia. Glycolysis and fermentation pathway-related genes, glucose phosphate isomerase (GPI), 6-phosphofructokinase (PFK), fructose 1,6-bisphosphate aldolase (ALD), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate decarboxylase (PDC), LDH, and ADH, were induced by low pO2. The activity of LDH and ADH was the highest in anoxic seeds. Germination under low O2 conditions initiated ethanolic fermentation. Therefore, sufficient oxygen availability is important for germination before photosynthesis provides necessary oxygen and the determination of an oxygen carrying capacity is important for uniform growth in space conditions.

Simple method to enhance positive bias stress stability of In-Ga-Zn-O thin-film transistors using a vertically graded oxygen-vacancy active layer.

Science.gov (United States)

Park, Ji Hoon; Kim, Yeong-Gyu; Yoon, Seokhyun; Hong, Seonghwan; Kim, Hyun Jae

2014-12-10

We proposed a simple method to deposit a vertically graded oxygen-vacancy active layer (VGA) to enhance the positive bias stress (PBS) stability of amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs). We deposited a-IGZO films by sputtering (target composition; In2O3:Ga2O3:ZnO = 1:1:1 mol %), and the oxygen partial pressure was varied during deposition so that the front channel of the TFTs was fabricated with low oxygen partial pressure and the back channel with high oxygen partial pressure. Using this method, we were able to control the oxygen vacancy concentration of the active layer so that it varied with depth. As a result, the turn-on voltage shift following a 10 000 s PBS of optimized VGA TFT was drastically improved from 12.0 to 5.6 V compared with a conventional a-IGZO TFT, without a significant decrease in the field effect mobility. These results came from the self-passivation effect and decrease in oxygen-vacancy-related trap sites of the VGA TFTs.

Oxygen sensor using proton-conductor thick-film operative at room temperature. Puroton dodentai atsumaku wo mochiita joon sadogata sanso sensor

Energy Technology Data Exchange (ETDEWEB)

Miura, Norio; Yoshida, Nobuaki; Matayoshi, Naoko; Shimizu, Yoichi; Yamazoe, Noboru; Kuwata, Shigeki [Kyushu Univ., Fukuoka, (Japan) Niihama National College of Tech., Ehime, (Japan)

1989-10-01

An amperometric solid-state oxygen sensor using a proton-conductor thick-film was examined as a miniaturized and intelligent oxygen sensor operative at room temperature. The good-conditioned proton-conductor film of about 10{mu}m in thickness without holes was formed on a porous alumina substrate by spin-coating the paste containing antimonic acid and a polyvinyl alcohol binder. Using this material, the thick-film oxygen sensor was made. A limiting current, controlled by oxygen permeation through the gas-diffusion layer, was observed when an external voltage was over 1.4V. The limiting current increased linearly with an increase in oxygen partial pressure up to 1.0 atm at an external voltage of 1.6V. The 90% response time for increasing oxygen partial pressure was about 40 seconds at 30 centigrade. Moreover, it was found that the sensor could also respond to dissolved oxygen in water at room temperature. With a sensor using a hydrophobic gas-diffusion layer containing a polystyrene binder, the limiting current was linear to the dissolved oxygen concentration up to 20ppm. 15 refs., 5 figs.

Fast removal of oxygen from biological systems

International Nuclear Information System (INIS)

Dewey, D.L.; Michael, B.D.

1975-01-01

Reference is made to the fact that if radiation is given at a high enough dose rate, the biological effect of oxygen is less than at low dose rates. Examples are given of 'break-point' experiments showing the effect. It is stated that the rapid removal of a substance by radiation is not confined to oxygen: the only criterion required to demonstrate the effect is that the chemical causes a measurable sensitization or protection at a concentration small enough so that it can be depleted at a relatively low dose of radiation. Sufficient confidence is now placed in the effect that it can be used the other way round; that is, to measure the position of the break-point and from this measurement determine the oxygen concentration at the target site at the instant before irradiation. Examples are given of the use of the high dose rate technique for measuring the oxygen concentration inside mammalian cells (Chinese hamster cells). The effects of partial pressures of inert gases, and the effect of elevated gas pressures, are discussed. (U.K.)

Study on the preparation of boron-rich film by magnetron sputtering in oxygen atmosphere

Energy Technology Data Exchange (ETDEWEB)

Pan, Zhangmin; Yang, Yiming; Huang, Jian; Ren, Bing; Yu, Hongze; Xu, Run; Ji, Huanhuan; Wang, Lin; Wang, Linjun, E-mail: ljwang@shu.edu.cn

2016-12-01

Highlights: • Boron ({sup 10}B) oxide films were successfully grown using RF magnetron sputtering. • Effects of oxygen partial pressure on the property of the films were studied. • Substrates were covered with B-rich film and film surface was covered with B{sub 2}O{sub 3}. • The growth mechanism of films in oxygen atmosphere was analyzed using XPS. - Abstract: In this paper, the growth of boron ({sup 10}B) oxide films on (1 0 0) silicon substrate were achieved by radio frequency (r.f.) magnetron sputtering under the different oxygen partial pressure with a target of boron and boron oxide. The structure and properties of deposited films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy spectrometer (FTIR), X-ray photoelectron spectroscopy (XPS), respectively. The results showed that the substrate was covered with boron-rich films tightly and the surface of films was covered with B{sub 2}O{sub 3}. And the growth mechanism of boron-rich film in oxygen atmosphere was also analyzed.

Oxygen isotope studies of the Salton Sea geothermal field

International Nuclear Information System (INIS)

Olson, E.R.

1978-01-01

Interbedded shales and sandstones were drilled to a depth of 1588 metres in Sinclair Number Four Well, Salton Sea Geothermal Field. Bottom hole temperatures are approximately 290 0 C. The oxygen dels of hydrothermal and detrital calcite have a systematic relationship at any depth in the geothermal reservoir. Typical values are: vein calcite, +6 0 / 00 ; calcite in white sandstone, +10 0 / 00 ; calcite in dark gray shale, +11 0 / 00 ; calcite in light gray shale, +17 0 / 00 ; calcite in red-brown shale, +20 0 / 00 . This succession represents decreasing water-rock interaction that is also indicated by the clay mineralogy of the shales. Permeability has a marked effect on the equilibration of water and rocks at any given temperature. Original differences in permeability have resulted in partial preservation of original detrital sedimentary compositions. The fluids in the Salton Sea Geothermal Field are probabaly partially evaporated Colorado River water, and their oxygen del values vary as much as 4 0 / 00 throughout the field. Truesdell's (1974) data suggest that dissolved salts may make the water oxygen activity del as much as 6 0 / 00 greater than the concentration del in the geothermal reservoir. Such an uncertainty is a serious impediment to precise isotope geothermometry in this system.(auth.)

Phase relations and equilibrium oxygen partial pressures in the iron-titanium-oxygen system at 1373 K; Tetsu-chitan-sansokei no 1373K ni okeru sokankei to heiko sanso bun`atsu

Energy Technology Data Exchange (ETDEWEB)

Inoue, O.; Ito, S.; Azakami, T. [Tohoku University, Sendai (Japan). Faculty of Engineering

1996-09-20

Phase relations and the equilibrium oxygen partial pressures in the Fe-Ti-O ternary system at 1373 K have been studied using a thermogravimetric technique in various atmospheres buffered by a CO-CO2 gas mixture and X-ray diffraction technique. The results indicate that at 1373 K ilmenite (FeTiO3) can be reduced and decomposed to iron and rutile (TiO2). Consequently upgrading ilmenite to a rutile substitute is possible in principle. From the present results, the standard Gibbs energy of the following reactions was calculated to be -184.7, -196.0 kJ{center_dot}mol{sup -1} at 1373 K, respectively. Fe(s)+FeTiO3(s)+1/2O{sub 2}(g)=Fe2TiO4(s), Fe(s)+TiO{sub 2}(s)+1/2O{sub 2}(g)=`FeTiO3`(s). Both the activities of magnetite and ulv6spinel in the Fe2TiO4-Fe3O4 spinel solid solutions coexisting with metallic iron at 1373 K obtained exhibit negative deviations from Raoult`s law. 19 refs., 10 figs., 3 tabs.

Balance of oxygen throughout the conversion of a high-level waste melter feed to glass

Czech Academy of Sciences Publication Activity Database

Lee, S.M.; Hrma, P.; Kloužek, Jaroslav; Pokorný, R.; Hujová, Miroslava; Dixon, D.R.; Schweiger, M. J.; Kruger, A.A.

2017-01-01

Roč. 43, č. 16 (2017), s. 13113-13118 ISSN 0272-8842 Institutional support: RVO:67985891 Keywords : oxygen mass balance * feed-to-glass conversion * evolved gas * oxygen partial pressure * Fe redox ratio Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass OBOR OECD: Ceramics Impact factor: 2.986, year: 2016

Pneumoperitoneum with Subcutaneous Emphysema after Percutaneous Endoscopic Gastrostomy

Directory of Open Access Journals (Sweden)

Yalin Iscan

2014-01-01

Full Text Available Percutaneous endoscopic gastrostomy is a safe way for enteral nutrition in selected patients. Generally, complications of this procedure are very rare but due to patients general health condition, delayed diagnosis and treatment of complications can be life threatening. In this study, we present a PEG-related massive pneumoperitoneum and subcutaneous emphysema in a patient with neuro-Behçet.

Telomere length differences between subcutaneous and visceral adipose tissue in humans

Energy Technology Data Exchange (ETDEWEB)

Lakowa, Nicole; Trieu, Nhu; Flehmig, Gesine [Department of Medicine, University of Leipzig, Leipzig (Germany); Lohmann, Tobias [Municipal Clinic Dresden-Neustadt, Dresden (Germany); Schön, Michael R. [Städtisches Klinikum Karlsruhe, Clinic of Visceral Surgery, Karlsruhe (Germany); Dietrich, Arne [Department of Surgery, University of Leipzig, Leipzig (Germany); IFB AdiposityDiseases, University of Leipzig, Leipzig (Germany); Zeplin, Philip Helge; Langer, Stefan [Department of Orthopaedics, Traumatology and Plastic Surgery, University of Leipzig, Leipzig (Germany); Stumvoll, Michael; Blüher, Matthias [Department of Medicine, University of Leipzig, Leipzig (Germany); Klöting, Nora, E-mail: nora.kloeting@medizin.uni-leipzig.de [IFB AdiposityDiseases, Junior Research Group 2 “Animal Models of Obesity”, University of Leipzig, Leipzig (Germany)

2015-02-13

Adipocyte hypertrophy and hyperplasia have been shown to be associated with shorter telomere length, which may reflect aging, altered cell proliferation and adipose tissue (AT) dysfunction. In individuals with obesity, differences in fat distribution and AT cellular composition may contribute to obesity related metabolic diseases. Here, we tested the hypotheses that telomere lengths (TL) are different between: (1) abdominal subcutaneous and omental fat depots, (2) superficial and deep abdominal subcutaneous AT (SAT), and (3) adipocytes and cells of the stromal vascular fraction (SVF). We further asked whether AT TL is related to age, anthropometric and metabolic traits. TL was analyzed by quantitative PCR in total human genomic DNA isolated from paired subcutaneous and visceral AT of 47 lean and 50 obese individuals. In subgroups, we analyzed TL in isolated small and large adipocytes and SVF cells. We find significantly shorter TL in subcutaneous compared to visceral AT (P < 0.001) which is consistent in men and subgroups of lean and obese, and individuals with or without type 2 diabetes (T2D). Shorter TL in SAT is entirely due to shorter TL in the SVF compared to visceral AT (P < 0.01). SAT TL is most strongly correlated with age (r = −0.205, P < 0.05) and independently of age with HbA1c (r = −0.5, P < 0.05). We found significant TL differences between superficial SAT of lean and obese as well as between individuals with our without T2D, but not between the two layers of SAT. Our data indicate that fat depot differences in TL mainly reflect shorter TL of SVF cells. In addition, we found an age and BMI-independent relationship between shorter TL and HbA1c suggesting that chronic hyperglycemia may impair the regenerative capacity of AT more strongly than obesity alone. - Highlights: • Telomere lengths (TL) differ between fat depots mainly due to different lengths in SVF. • TL is not associated with gender, BMI and T2D. • The tendency for

Telomere length differences between subcutaneous and visceral adipose tissue in humans

International Nuclear Information System (INIS)

Lakowa, Nicole; Trieu, Nhu; Flehmig, Gesine; Lohmann, Tobias; Schön, Michael R.; Dietrich, Arne; Zeplin, Philip Helge; Langer, Stefan; Stumvoll, Michael; Blüher, Matthias; Klöting, Nora

2015-01-01

Adipocyte hypertrophy and hyperplasia have been shown to be associated with shorter telomere length, which may reflect aging, altered cell proliferation and adipose tissue (AT) dysfunction. In individuals with obesity, differences in fat distribution and AT cellular composition may contribute to obesity related metabolic diseases. Here, we tested the hypotheses that telomere lengths (TL) are different between: (1) abdominal subcutaneous and omental fat depots, (2) superficial and deep abdominal subcutaneous AT (SAT), and (3) adipocytes and cells of the stromal vascular fraction (SVF). We further asked whether AT TL is related to age, anthropometric and metabolic traits. TL was analyzed by quantitative PCR in total human genomic DNA isolated from paired subcutaneous and visceral AT of 47 lean and 50 obese individuals. In subgroups, we analyzed TL in isolated small and large adipocytes and SVF cells. We find significantly shorter TL in subcutaneous compared to visceral AT (P < 0.001) which is consistent in men and subgroups of lean and obese, and individuals with or without type 2 diabetes (T2D). Shorter TL in SAT is entirely due to shorter TL in the SVF compared to visceral AT (P < 0.01). SAT TL is most strongly correlated with age (r = −0.205, P < 0.05) and independently of age with HbA1c (r = −0.5, P < 0.05). We found significant TL differences between superficial SAT of lean and obese as well as between individuals with our without T2D, but not between the two layers of SAT. Our data indicate that fat depot differences in TL mainly reflect shorter TL of SVF cells. In addition, we found an age and BMI-independent relationship between shorter TL and HbA1c suggesting that chronic hyperglycemia may impair the regenerative capacity of AT more strongly than obesity alone. - Highlights: • Telomere lengths (TL) differ between fat depots mainly due to different lengths in SVF. • TL is not associated with gender, BMI and T2D. • The tendency for

SNP in TXNRD2 Associated With Radiation-Induced Fibrosis: A Study of Genetic Variation in Reactive Oxygen Species Metabolism and Signaling

International Nuclear Information System (INIS)

Edvardsen, Hege; Landmark-Høyvik, Hege; Reinertsen, Kristin V.; Zhao, Xi; Grenaker-Alnæs, Grethe Irene; Nebdal, Daniel; Syvänen, Ann-Christine; Rødningen, Olaug; Alsner, Jan; Overgaard, Jens; Borresen-Dale, Anne-Lise; Fosså, Sophie D.; Kristensen, Vessela N.

2013-01-01

Purpose: The aim of the study was to identify noninvasive markers of treatment-induced side effects. Reactive oxygen species (ROS) are generated after irradiation, and genetic variation in genes related to ROS metabolism might influence the level of radiation-induced adverse effects (AEs). Methods and Materials: 92 breast cancer (BC) survivors previously treated with hypofractionated radiation therapy were assessed for the AEs subcutaneous atrophy and fibrosis, costal fractures, lung fibrosis, pleural thickening, and telangiectasias (median follow-up time 17.1 years). Single-nucleotide polymorphisms (SNPs) in 203 genes were analyzed for association to AE grade. SNPs associated with subcutaneous fibrosis were validated in an independent BC survivor material (n=283). The influence of the studied genetic variation on messenger ribonucleic acid (mRNA) expression level of 18 genes previously associated with fibrosis was assessed in fibroblast cell lines from BC patients. Results: Subcutaneous fibrosis and atrophy had the highest correlation (r=0.76) of all assessed AEs. The nonsynonymous SNP rs1139793 in TXNRD2 was associated with grade of subcutaneous fibrosis, the reference T-allele being more prevalent in the group experiencing severe levels of fibrosis. This was confirmed in another sample cohort of 283 BC survivors, and rs1139793 was found significantly associated with mRNA expression level of TXNRD2 in blood. Genetic variation in 24 ROS-related genes, including EGFR, CENPE, APEX1, and GSTP1, was associated with mRNA expression of 14 genes previously linked to fibrosis (P≤.005). Conclusion: Development of subcutaneous fibrosis can be associated with genetic variation in the mitochondrial enzyme TXNRD2, critically involved in removal of ROS, and maintenance of the intracellular redox balance

X-ray photoelectron spectroscopy investigation of ion beam sputtered indium tin oxide films as a function of oxygen pressure during deposition

International Nuclear Information System (INIS)

Nelson, A.J.; Aharoni, H.

1987-01-01

X-ray photoelectron spectroscopy analysis was performed on ion beam sputter deposited films of indium tin oxide as a function of O 2 partial pressure during deposition. The oxygen partial pressure was varied over the range of 2.5 x 10 -6 --4.0 x 10 -5 Torr. Changes in composition as well as in the deconvoluted In 3d 5 /sub // 2 , Sn 3d 5 /sub // 2 , and O 1s core level spectra were observed and correlated with the variation of the oxygen partial pressure during deposition. Results show that the films become increasingly stoichiometric as P/sub =/ is increased and that the excess oxygen introduced during deposition is bound predominantly to the Sn and has little or no effect on the In--O bonding

Oxygen release technique as a method for the determination of "δ-pO2-T" diagrams for MIEC oxides.

Science.gov (United States)

Starkov, Ilya; Bychkov, Sergey; Matvienko, Alexander; Nemudry, Alexander

2014-03-28

A new approach to the determination of oxygen nonstoichiometry (δ) of MIEC oxides as a continuous function of pO2 at high temperatures was developed. The description of the model allowing one to distinguish the contribution of oxygen released from the samples to the partial pressure of oxygen at the outlet of the continuous-flow fixed-bed reactor after the stepwise change of the oxygen partial pressure of inlet gas from 0.2 to 10(-5) atm and to calculate the dependence of δ on pO2 is presented. The criterion for assessing the achievement of quasi equilibrium release of oxygen from the MIEC oxides is proposed. The adequacy of the method was confirmed by comparing the obtained and published data for well-studied SrCo0.8Fe0.2O3-δ and SrFeO3-δ MIEC oxides.

Cutaneous Involvement in the Deep Mycoses: A Literature Review. Part I-Subcutaneous Mycoses.

Science.gov (United States)

Carrasco-Zuber, J E; Navarrete-Dechent, C; Bonifaz, A; Fich, F; Vial-Letelier, V; Berroeta-Mauriziano, D

2016-12-01

The deep mycoses are uncommon in our setting. These fungal infections occur mainly in immunosuppressed patients or in tropical climates, and include subcutaneous infections and systemic infections. The skin is always involved in the former. In the first part of this review, we describe the main subcutaneous mycoses: sporotrichosis, chromoblastomycosis, mycetoma, phaeohyphomycosis, hyalohyphomycosis, and lacaziosis. Early recognition and treatment is important, as these infections are frequently associated with high morbidity. Copyright © 2016 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

Associations of infant subcutaneous fat mass with total and abdominal fat mass at school-age. The Generation R Study

Science.gov (United States)

Santos, Susana; Gaillard, Romy; Oliveira, Andreia; Barros, Henrique; Abrahamse-Berkeveld, Marieke; van der Beek, Eline M; Hofman, Albert; Jaddoe, Vincent WV

2017-01-01

Background Skinfold thickness enables the measurement of overall and regional subcutaneous fatness in infancy and may be associated with total and abdominal body fat in later childhood. We examined the associations of subcutaneous fat in infancy with total and abdominal fat at school-age. Methods In a population-based prospective cohort study among 821 children, we calculated total subcutaneous fat (sum of biceps, triceps, suprailiacal and subscapular skinfold thicknesses) and central-to-total subcutaneous fat ratio (sum of suprailiacal and subscapular skinfold thicknesses/total subcutaneous fat) at 1.5 and 24 months. At 6 years, we measured fat mass index (total fat/height3), central-to-total fat ratio (trunk fat/total fat) and android-to-gynoid fat ratio (android fat/gynoid fat) by dual-energy X-ray absorptiometry and preperitoneal fat mass area by abdominal ultrasound. Results Central-to-total subcutaneous fat ratio at 1.5 months was positively associated with fat mass index and central-to-total fat ratio at 6 years, whereas both total and central-to-total subcutaneous fat ratio at 24 months were positively associated with all childhood adiposity measures (pfat at 24 months was associated with an increased risk of childhood overweight (Odds Ratio 1.70 [95% Confidence Interval 1.36, 2.12]). These associations were weaker than those for body mass index and stronger among girls than boys. Conclusions Subcutaneous fat in infancy is positively associated with total and abdominal fat at school-age. Our results also suggest that skinfold thicknesses add little value to estimate later body fat, as compared to body mass index. PMID:27225335

Subcutaneous and intrahepatic growth of human hepatoblastoma in immunodeficient mice

NARCIS (Netherlands)

Schnater, J. Marco; Bruder, Elisabeth; Bertschin, Sibylle; Woodtli, Thomas; de Theije, Chiel; Pietsch, Torsten; Aronson, Daniel C.; von Schweinitz, Dietrich; Lamers, Wouter H.; Köhler, Eleonore S.

2006-01-01

BACKGROUND/AIMS: Hepatoblastoma is the most frequent malignant pediatric liver tumor. Approximately 25% of hepatoblastoma patients cannot be cured with current treatment protocols. Additional treatment options must, therefore, be developed. Subcutaneous animal models for hepatoblastoma exist, but a

Gigantic subcutaneous lipoma – A case report

Directory of Open Access Journals (Sweden)

Christian Lyngsaa Lang

2015-03-01

Full Text Available Lipomas are the most common benign mesenchymal tumour. The solitary subcutaneous lipoma accounts for approximately one-quarter to one-half of all soft tissue tumours. The preferred locations include the trunk, shoulder, upper arm, and the neck. In this case report, we present a gigantic axillary lipoma weighing 23.35 kg. Due to the tumour mass and its long-term presence, the lipoma caused anatomical changes in the axilla making its removal challenging and difficult.

The effect of loading and particle size on the oxygen reaction in CGO impregnated Pt electrodes

DEFF Research Database (Denmark)

Lund, Anders; Hansen, Karin Vels; Jacobsen, Torben

2012-01-01

Porous platinum electrodes impregnated with Gd x Ce1−x O2−δ (CGO) are investigated to characterise how nano-sized CGO grains affect the oxygen reaction. Impedance measurements were performed at temperatures between 450 and 750 °C and at oxygen partial pressures of 0.2 and 5 × 10−5 bar for electro......Porous platinum electrodes impregnated with Gd x Ce1−x O2−δ (CGO) are investigated to characterise how nano-sized CGO grains affect the oxygen reaction. Impedance measurements were performed at temperatures between 450 and 750 °C and at oxygen partial pressures of 0.2 and 5 × 10−5 bar...... for electrodes with various CGO loadings and electrodes annealed at various temperatures. The morphology was characterised by scanning electron microscopy and the CGO grain size was determined from X-ray diffraction peak broadening. The results showed that the polarisation resistance decreased with increasing...

Improvement of metabolic disorders by an EP2 receptor agonist via restoration of the subcutaneous adipose tissue in pulmonary emphysema.

Science.gov (United States)

Tsuji, Takao; Yamaguchi, Kazuhiro; Kikuchi, Ryota; Nakamura, Hiroyuki; Misaka, Ryoichi; Nagai, Atsushi; Aoshiba, Kazutetsu

2017-05-01

Chronic obstructive pulmonary disease (COPD) is often associated with co-morbidities. Metabolic disorders like hyperlipidemia and diabetes occur also in underweight COPD patients, although the mechanism is uncertain. Subcutaneous adipose tissue (SAT) plays an important role in energy homeostasis, since restricted capacity to increase fat cell number with increase in fat cell size occurring instead, is associated with lipotoxicity and metabolic disorders. The aim of this study is to show the protective role of SAT for the metabolic disorders in pulmonary emphysema of a murine model. We found ectopic fat accumulation and impaired glucose homeostasis with wasting of SAT in a murine model of elastase-induced pulmonary emphysema (EIE mice) reared on a high-fat diet. ONO-AE1-259, a selective E-prostanoid (EP) 2 receptor agonist, improved angiogenesis and subsequently adipogenesis, and finally improved ectopic fat accumulation and glucose homeostasis with restoration of the capacity for storage of surplus energy in SAT. These results suggest that metabolic disorders like hyperlipidemia and diabetes occured in underweight COPD is partially due to the less capacity for storage of surplus energy in SAT, though the precise mechanism is uncertained. Our data pave the way for the development of therapeutic interventions for metabolic disorders in emphysema patients, e.g., use of pro-angiogenic agents targeting the capacity for storage of surplus energy in the subcutaneous adipose tissue. Copyright © 2017 Elsevier Inc. All rights reserved.