This study aimed to compare gas exchange with heliox and oxygen-enriched air during piston-type high-frequency oscillatory ventilation (HFOV). We hypothesized that helium gas would improve both carbon dioxide elimination and arterial oxygenation during piston-type HFOV. Five rabbits were prepared and ventilated by piston-type HFOV with carrier 50% helium/oxygen (heliox50) or ...

The cerebral tissue oxygenation index (TOI) and fractional tissue oxygen extraction (FTOE) reflect the cerebral oxygenation. We studied the effect of glycaemia on the TOI and FTOE, as measured by near-infrared-spectroscopy (NIRS). We continuously measured TOI, glycaemia, mean arterial blood pressure (MABP), saturation (SaO(2)) and transcutaneous carbon dioxide pressure (tPCO(2)) ...

Anodized-aluminum pressure-sensitive paint (AA-PSP) has been used as a global pressure sensor for unsteady flow measurements. We use a dipping deposition method to apply a luminophore on a porous anodized-aluminum surface, controlling the luminophore concentration of the dipping method to optimize AA-PSP characteristics. The concentration is varied from 0.001 to ...

The American Society of Anesthesiologists published monitoring requirements for non-anesthesia providers performing sedation and analgesia in 2002. This manuscript covered not only the monitoring of patients under sedation and analgesia but pre-procedure evaluation and preparation, personnel availability and training, emergency equipment availability, use of supplemental oxygen, sedative-analgesic agents, and discharge ...

The effect of hydrostatic pressure on the waveguiding properties of high birefringence photonic crystal fibers (HiBi PCF) is evaluated both numerically and experimentally. A fiber design presenting form birefringence induced by two enlarged holes in the innermost ring defining the fiber core is investigated. Numerical results show that modal sensitivity ...

After studying the performance and characteristics of actual laminar flowmeters a new disposition for this type of sensors is proposed in such a way that the measurement errors introduced by the intrinsic nature of the device can be minimized. The preliminary study shows that the developing entry region introduces non-linearity ...

Fighter pilots may develop slowly progressive deformities of their noses during their flying careers. The spectrum of deformities that may be acquired ranges from soft tissue to osseous changes. The main cause is the varying pressure exerted by the oxygen mask on the skin and bony pyramid of the nose ...

BACKGROUND AND OBJECTIVE: Continuous monitoring of PaO(2) in seriously ill patients is an important aspect of clinical management, especially for patients with acute lung injury (ALI) or acute respiratory distress syndrome. We have developed a fibreoptic sensor to detect PaO(2)in vivo based on fluorescence quenching technology. In this study we ...

OBJECTIVE: To assess the effect of the duration of spontaneous hypoxic episodes and variations in haemodynamic parameters on cerebral and renal tissue oxygenation (rSo(2)C and rSo(2)R) in clinically stable preterm infants. DESIGN: Observational study. SETTING: Neonatal intensive care unit of a university-affiliated children's hospital. Patients rSo(2)C and rSo(2)R and haemodynamic ...

Ascent to altitude is associated with a fall in barometric pressure, and with it a decline in the partial pressure of atmospheric (and thus alveolar) oxygen. As a result, a variety of adaptive physiological processes are engaged to mitigate the fall in tissue convective oxygen delivery which might otherwise occur. ...

BACKGROUND: Oxygen supplies capable of supporting transtracheal jet ventilators can be lifesaving. There is not much information about which oxygen sources (readily available inside and outside operating rooms) have sufficient driving pressure for transtracheal jet ventilation. METHODS: We measured driving pressures (upstream or residual oxygen pressure) in a specially designed ...

We present the results of a plane wave based density functional study of the structure and properties of tetragonal zirconia in the range of pressures from 0 to 50 GPa. We predict a transition to a fluorite-type cubic structure at 37 GPa which is likely to be of a soft mode origin ...

Rh/SiO(2) model catalyst surfaces are prepared under ultra-high vacuum conditions and examined in situ using scanning tunneling microscope and CO infrared reflection absorption techniques, to quantify the number and kinds of active Rh surface sites available for kinetic reaction (CO oxidation) as a function of Rh particle size. The results ...

INTRODUCTION: Escape from a disabled submarine has many inherent risks including the development of venous gas emboli (VGE). Breathing hyperoxic gas during rapid ascent from 2500 kPa (240 msw) reduces VGE; we investigated whether it would also be beneficial during an escape from 3000 kPa (290 msw), thought to be ...

An increasing amount of evidence points to cerebral embolization during cardiopulmonary bypass (CPB) as the principal etiologic factor of neurologic complications. In this study, the capability of capturing and classification of gaseous emboli and pressure drop of three different membrane oxygenators (Sorin Apex, Terumo Capiox SX25, Maquet QUADROX) were measured ...

BACKGROUND: Guidelines recommend avoidance of excessive oxygen administration during neonatal resuscitation. Blenders are used in some but not all hospitals. It has been suggested that self-inflating bags without a reservoir deliver around 40% oxygen and could be used to provide an inexpensive and effective technique of avoiding oxygen toxicity. OBJECTIVE: ...

We investigated return of spontaneous circulation and of cerebral oxygenation after asphyxia-induced cardiac arrest, using ventilation with air, throughout, or with 100% oxygen for a shorter or longer period. Arterial pressure, heart rate, regional cerebral oxygen saturation (CrSO2), and brain tissue oxygen tension (PbtO2) were measured in 1-d-old piglets that ...

Calcium fluoride CaF(2) has been studied by using density functional theory (DFT) with the generalized gradient approximation (GGA). Our results demonstrate that the sequence of the pressure-induced structural transition of CaF(2) is the fluorite structure ([Formula: see text]), the orthorhombic cotunnite-type structure (Pnma), and the hexagonal Ni(2)In-type structure (P6(3)/mmc). The ...

The surface morphology of Al(2)O(3)-doped ZnO (AZO, 2 wt%) thin films varies from a uniform layer to nanorod structure by simply controlling oxygen pressure during growth. All AZO films were deposited on sapphire(0001) substrates using a pulsed laser deposition (PLD) technique. In the low oxygen pressure regime (vacuum approximately 50 ...

Cerium oxide (CeO2) thin films were prepared on (100) Si and glass substrates using pulsed laser ablation at different oxygen partial pressures (2.5 x 10(-5)-3.5 x 10(-1) mbar) and at a substrate temperature of 873 K. XRD studies on the films showed that the films are polycrystalline having fluorite structure. ...

OBJECTIVES: Treatment of cutaneous wounds is one of the many applications of hyperbaric oxygen therapy (HBO). However, the complex regulation of skin microcirculation during different phases of HBO is not completely understood. We therefore investigated skin microcirculation and oxygenation during HBO and normobaric oxygen (NBO) exposure. METHODS: Seven healthy volunteers ...

In Drosophila melanogaster and other insects, increases in atmospheric oxygen partial pressure (aPO(2)) tend to increase adult body size and decrease tracheal diameters and tracheolar proliferation. If changes in tracheal morphology allow for functional compensation for aPO(2), we would predict that higher aPO(2) would be associated with higher critical PO(2) ...

OBJECTIVE: The purpose of this study was to investigate the relationship between the ventilatory mode used during one-lung ventilation (OLV) and intraoperative and early postoperative arterial oxygenation in patients undergoing thoracic surgery. METHODS: A prospective, randomized clinical trial. SETTING: A tertiary care university hospital single institution. PARTICIPANTS: One hundred ten ...

OBJECTIVES: Delayed sternal closure after pediatric cardiac surgery can temporarily impair cardiac output. Cerebral and somatic regional oxygen saturation measured by using near-infrared spectroscopy (NIRS) have been used as potential surrogates of cerebral and somatic mixed venous oxygen saturation. We hypothesized that cerebral and somatic regional oxygen saturation correlate with ...

The magnetic properties of the antiferromagnet CeNiSnH and of the ferromagnet CeNiSnH(1.8) on hydrostatic pressure (0≤P≤10.8 bar) have been determined using a miniature piston-cylinder CuBe pressure cell. With increasing P, the Néel temperature of CeNiSnH increases weakly from 4.77 to 5.01 K whereas the Curie temperature of CeNiSnH(1.8) decreases rapidly from 7.16 ...

An asymmetric derivative of the triarylmethyl radical, TAM-H, containing one aldehyde and two carboxyl groups, was synthesized. The electron paramagnetic resonance (EPR) spectrum of TAM-H is characterized by a doublet of narrow lines with a linewidth of 105 mG under anoxic conditions and hyperfine interaction constant of 245 mG. The ...

BACKGROUND: Recent scientific evidence has demonstrated the importance of good quality chest compressions without interruption to improve cardiac arrest resuscitation rates, and suggested that a de-emphasis on minute ventilation is needed. However, independent of ventilation, the role of oxygen and the optimal oxygen concentration during CPR is not known. Previous ...

OBJECTIVE: Hemoglobin-based oxygen carriers (HBOC) of several types scavenge nitric oxide from the vasculature resulting in vasoconstriction and hypertension, both systemic and pulmonary. Phosphodiesterase-5 (PDE5) inhibitors promote nitric oxide activity and enhance vasodilation. The purpose of this study was to determine whether combined therapy of glutaraldehyde-polymerized bovine hemoglobin (HBOC) with ...

An 8-yr-old castrated male slender-tailed meerkat (Suricata suricatta) was anesthetized for physical examination and dental prophylaxis. To facilitate intubation, two short bursts of benzocaine spray were applied topically to the glottis. Shortly thereafter, the meerkat developed a muddy, blue-gray mucous membrane color and low oxygen saturation readings measured via pulse ...

The high-pressure induced phase transformation from the zinc blende to rocksalt structure in SiC has been studied by the ab initio molecular dynamics method. The simulations showed that SiC passes through a tetragonal intermediate state before transforming to a monoclinic phase at 160 GPa. The mechanism for this phase transformation agrees ...

This paper summarizes experimental evidence of anomalous luminescence in Eu(2+)-doped fluoride crystals Ba(x)Sr(1-x)F(2) (x = 0, 0.3, 0.5 and 1). Luminescence, luminescence excitation spectra and luminescence kinetics obtained at ambient and high hydrostatic pressure at various temperatures are discussed. Hydrostatic pressure was shown to cause a redshift of normal [Formula: ...

Hyperpolarized (3)He (HP (3)He) MRI shows promise to assess structural and functional pulmonary parameters in a sensitive, regional, and noninvasive way. Structural HP (3)He MRI has applied the apparent diffusion coefficient (ADC) for the detection of disease-induced lung microstructure changes at the alveolar level, and HP (3)He pulmonary partial pressure ...

We demonstrate the application of polydimethylsiloxane (PDMS) thin films in highly sensitive pressure and oxygen sensors, designed for pressure and oxygen content measurements within the heart and blood vessels. PDMS thin film displacement as a result of pressure changes was transduced by a capacitive detection technique to produce quantitative measurement ...

BACKGROUND: Vasopressor agents are commonly used to increase mean arterial pressure (MAP) in order to secure a pressure gradient to perfuse vital organs. The influence of norepinephrine on cerebral oxygenation is not clear. The aim of this study was to evaluate the impact of the infusion of norepinephrine on cerebral ...

The double perovskite Sr(2)FeMoO(6) has been prepared in polycrystalline form by high-pressure methods, starting from a precursor developed via a citrate technique, containing an elevated degree of anti-site disordering. The application of high external pressure (2 GPa) to Sr(2)FeMoO(6) promotes the long distance Fe/Mo cationic order, due to the smaller lattice ...

The influence of 2 different levels of the inspired oxygen fraction (FiO2) on blood gas variables was evaluated in dogs with high intracranial pressure (ICP) during propofol anesthesia (induction followed by a continuous rate infusion [CRI] of 0.6 mg/kg/min) and intermittent positive pressure ventilation (IPPV). Eight adult mongrel dogs were ...

A crystal phase in equilibrium under changing pressure traces out a line in structure space where each point corresponds to a structure. Along that equilibrium line the structure and all static properties describe the static behavior of the phase, including two sets of elastic constants and the bulk modulus. We ...

This paper describes the development and application of a novel method for the measurement of grain boundary electrical conductivity of rock at high temperature and pressure. In this method, the metal electrodes, the corresponding metal shielding case, and the sleeves are altered in order to appropriately adjust and monitor the ...

Membrane-aerated biofilms with oxygen and nutrients diffusing from the opposite sides possess distinct properties, including the ability to couple aerobic and anaerobic processes. The objective of this study was to examine the effects of oxygen partial pressure and chemical oxygen demand (COD) loading on biofilm properties. Two laboratory-scale membrane-aerated bioreactors ...

The relationship between metabolism of neuronal activity, microvascular organization, and blood flow dynamics is critical for interpreting functional brain imaging. Here we used the rat dorsal olfactory bulb as a model to determine in vivo the correlation between action potential propagation, synaptic transmission, oxygen consumption, and capillary density during odor ...

Recent theoretical simulations using density functional theory (DFT) and novel low temperature high energy x-ray diffraction experiments clearly show the existence of a high pressure morphotropic phase boundary (MPB) in pure PbTiO(3). The experiments show a richer phase diagram than the simulations, with multiple monoclinic phases (Pm and Cm) in ...

Pressure effects on the phase stability of cubic BNC alloys were examined by Monte Carlo simulations and the cluster expansion technique based on first-principles calculations. At pressure P = 10 GPa, solution energy of neighboring B-N and C-C atoms into diamond and cubic BN are both higher than those at P ...

BACKGROUND: The level of environmental hypobaric hypoxia that affects climbers at the summit of Mount Everest (8848 m [29,029 ft]) is close to the limit of tolerance by humans. We performed direct field measurements of arterial blood gases in climbers breathing ambient air on Mount Everest. METHODS: We obtained samples ...

Pressure perturbation calorimetry (PPC) is a new technique that makes possible to study the volumetric changes that occur upon protein unfolding. Here, we summarize the thermodynamic foundation of the method and introduce a two-state model for the analysis of the unfolding data monitored by PPC. Several examples of data analysis ...

Sagami Bay is an active tectonic area in Japan. In 1993, a real-time deep sea floor observatory was deployed at 1,175 m depth about 7 km off Hatsushima Island, Sagami Bay to monitor seismic activities and other geophysical phenomena. Video cameras monitored biological activities associated with tectonic activities. The observation ...

INTRODUCTION: Oxygen has been shown to improve morbidity, mortality and quality of life in hypoxaemic patients with chronic lung conditions. Assessing compliance has always been difficult and there are no accurate means of assessment available in clinical practice. We have trialled an oxygen compliance monitor called oxymon to address this. ...

Mortality of severe acute respiratory distress syndrome in adults is still unacceptably high. Extracorporeal membrane oxygenation (ECMO) could represent an important treatment option, if complications were reduced by new technical developments. Efficiency, side effects and outcome of treatment with a new miniaturized device for veno-venous extracorporeal gas transfer were analysed ...

The structural parameters, elastic constants and electronic structure of NbB(2) under pressure are investigated by using first-principles plane-wave pseudopotential density functional theory within the generalized gradient approximation (GGA). The obtained results are in agreement with the available theoretical data. It is found that the elastic constants and the Debye temperature ...

The lattice and elastic instabilities of rocksalt (RS) calcium oxide CaO under pressure are extensively studied to reveal the physically driven mechanism of the phase transition from RS to CsCl structure by using the pseudopotential plane-wave method within density-functional theory. The predicted phase transition pressure is 66.38 GPa, employing the total ...

Vitreous surgery has various physiological and clinical consequences, both beneficial and harmful. Vitrectomy reduces the risk of retinal neovascularization, while increasing the risk of iris neovascularization, reduces macular edema and stimulates cataract formation. These clinical consequences may be understood with the help of classical laws of physics and physiology. The ...