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Sample records for spontaneous breathing sb

  1. Voluntary breath holding affects spontaneous brain activity measured by magnetoencephalography

    NARCIS (Netherlands)

    Schellart, N. A.; Reits, D.

    1999-01-01

    Spontaneous brain activity was measured by multichannel magnetoencephalography (MEG) during voluntary breath holds. Significant changes in the activity are limited to the alpha rhythm: 0.25 Hz frequency increase and narrowing of the peak. The area of alpha activity shifts slightly toward (fronto-)

  2. Changes in breathing variables during a 30-minute spontaneous breathing trial.

    Science.gov (United States)

    Figueroa-Casas, Juan B; Connery, Sean M; Montoya, Ricardo

    2015-02-01

    Spontaneous breathing trials (SBTs) are increasingly performed. Significant changes in monitored breathing variables and the timing of those changes during the trial have important implications for its outcome determination and supervision. We aimed to study the magnitude and timing of change in breathing variables during the course of a 30-min SBT. Breathing variables were continuously measured and averaged by minute during the SBT in 32 subjects with trial success and 8 subjects with trial failure from a general ICU population. Percentage changes in breathing variables during the trial and proportions of subjects showing a ≥20% change at different time points relative to the second minute of the trial were calculated. The commonly monitored breathing variables (frequency, tidal volume, their ratio, and minute ventilation) showed median coefficients of variation of breathing variables remain relatively constant, and potentially significant changes in these variables after 10 min into the trial are uncommon. These findings should be considered when addressing aspects of duration and supervision of SBTs in weaning protocols. Copyright © 2015 by Daedalus Enterprises.

  3. Spontaneous breathing with biphasic positive airway pressure attenuates lung injury in hydrochloric acid-induced acute respiratory distress syndrome.

    Science.gov (United States)

    Xia, Jingen; Zhang, Heng; Sun, Bing; Yang, Rui; He, Hangyong; Zhan, Qingyuan

    2014-06-01

    It has been proved that spontaneous breathing (SB) with biphasic positive airway pressure (BIPAP) can improve lung aeration in acute respiratory distress syndrome compared with controlled mechanical ventilation. The authors hypothesized that SB with BIPAP would attenuate lung injury in acute respiratory distress syndrome compared with pressure-controlled ventilation. Twenty male New Zealand white rabbits with hydrochloric acid aspiration-induced acute respiratory distress syndrome were randomly ventilated using the BIPAP either with SB (BIPAP plus SB group) or without SB (BIPAP minus SB group) for 5 h. Inspiration pressure was adjusted to maintain the tidal volume at 6 ml/kg. Both groups received the same positive end-expiratory pressure level at 5 cm H2O for hemodynamic goals. Eight healthy animals without ventilatory support served as the control group. The BIPAP plus SB group presented a lower ratio of dead space ventilation to tidal volume, a lower respiratory rate, and lower minute ventilation. No significant difference in the protein levels of interleukin-6 and interleukin-8 in plasma, bronchoalveolar lavage fluid, and lung tissue were measured between the two experimental groups. However, SB resulted in lower messenger ribonucleic acid levels of interleukin-6 (mean ± SD; 1.8 ± 0.7 vs. 2.6 ± 0.5; P = 0.008) and interleukin-8 (2.2 ± 0.5 vs. 2.9 ± 0.6; P = 0.014) in lung tissues. In addition, lung histopathology revealed less injury in the BIPAP plus SB group (lung injury score, 13.8 ± 4.6 vs. 21.8 ± 5.7; P hydrochloric acid-induced acute respiratory distress syndrome, SB with BIPAP attenuated lung injury and improved respiratory function compared with controlled ventilation with low tidal volume.

  4. Different spontaneous breathing trials in patients with atrial fibrillation

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    Y.-H. Tseng

    2015-09-01

    Full Text Available Introduction: Weaning from mechanical ventilation is one of the most important and challenging problems for most intensive care unit (ICU patients. Spontaneous breathing trial (SBT is the most common method used to evaluate patients’ ability to breathe by themselves and plays an important role in decision making for weaning. The aim of our study was to investigate the effect of different methods of SBT in respiratory care unit (RCU patients with atrial fibrillation (AF on weaning outcome. Methods: We retrospectively analyzed different methods of SBT in patients with and without AF. We enrolled RCU patients who required mechanical ventilation and had undergone transthoracic echocardiography from January 2011 to January 2012. Results: There was a higher SBT passing rate among AF patients who received pressure support ventilation (PSV trial than in those who received T-piece trail (92.5% vs. 73.1%, p = 0.041. The weaning rates between these two groups were not significantly different (83.8% vs. 94.7%, p = 0.403. Total ventilator days were longer in T-piece group than in PSV group (median 40.0, IQR: 18.2–125.1 days vs. 33.0, IQR: 29.6–51.0 days respectively, p = 0.580, but this difference was not statistically significant. These results were not found in patients without AF. Conclusions: The use of PSV trial might be considered first instead of T-piece trial for SBT when AF patients were ready to wean. Keywords: Atrial fibrillation (AF, Intensive care unit (ICU, Mechanical ventilation, Spontaneous breathing trial (SBT, Ventilator weaning

  5. THE DIFFERENCE IN RESPIRATORY AND BLOOD GAS VALUES DURING RECOVERY AFTER EXERCISE WITH SPONTANEOUS VERSUS REDUCED BREATHING FREQUENCY

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    Jernej Kapus

    2009-09-01

    Full Text Available Extrapolation from post-exercise measurements has been used to estimate respiratory and blood gas parameters during exercise. This may not be accurate in exercise with reduced breathing frequency (RBF, since spontaneous breathing usually follows exercise. This study was performed to ascertain whether measurement of oxygen saturation and blood gases immediately after exercise accurately reflected their values during exercise with RBF. Eight healthy male subjects performed an incremental cycling test with RBF at 10 breaths per minute. A constant load test with RBF (B10 was then performed to exhaustion at the peak power output obtained during the incremental test. Finally, the subjects repeated the constant load test with spontaneous breathing (SB using the same protocol as B10. Pulmonary ventilation (VE, end-tidal oxygen (PETO2, and carbon dioxide pressures (PETCO2 and oxygen saturation (SaO2 were measured during both constant load tests. The partial pressures of oxygen (PO2 and carbon dioxide (PCO2 in capillary blood were measured during the last minute of exercise, immediately following exercise and during the third minute of recovery. At the end of exercise RBF resulted in lower PETO2, SaO2 and PO2, and higher PETCO2 and PCO2 when compared to spontaneous breathing during exercise. Lower SaO2 and PETO2 were detected only for the first 16s and 20s of recovery after B10 compared to the corresponding period in SB. There were no significant differences in PO2 between SB and B10 measured immediately after the exercise. During recovery from exercise, PETCO2 remained elevated for the first 120s in the B10 trial. There were also significant differences between SB and B10 in PCO2 immediately after exercise. We conclude that RBF during high intensity exercise results in hypoxia; however, due to post-exercise hyperpnoea, measurements of blood gas parameters taken 15s after cessation of exercise did not reflect the changes in PO2 and SaO2 seen during

  6. [A respiratory microvalve for spontaneously breathing anesthetized small animals].

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    Barnikol, W K; Hiller, B; Guth, S

    1994-03-01

    For the accurate functional analysis of the gas exchange in the lungs or evaluation of artificial oxygen carriers in spontaneously breathing anaesthetized small animals, we developed a new respiratory micro-valve. The body of the valve is made of aluminium, and the flaps are made of silicone rubber. The maximum flow rate in a rat measured with a pneumotachograph and the micro-valve was an average of 19.9 ml/s during inspiration, and 17.8 ml/s during expiration. The pressure measured in the tracheal tube was -0.85 during inspiration, and +0.39 cm H2O during expiration; the end-expiratory pressure in the tube was zero. In two experiments with anaesthetised rats lasting 4-5 hours, ventilation, oxygen uptake, carbon dioxide release and the respiratory exchange ratio were 638 ml/min/kg, 21.7 ml O2(STPD)/min/kg, 16.6 ml CO2(STPD)/min/kg, and 0.77, respectively. There was no significant change in any parameter during the experiment. The micro-valve increases the dead space by approximately 35%, but this is well tolerated by the rats, which compensate by increasing their tidal volume by about 10 to 15%. The major advantage of using the micro-valve in comparison with other methods is the fact that the true difference between inspiratory and mean mixed expiratory gas can be measured with great accuracy. The micro-valve can readily be adjusted for optimal use with a range of animals.

  7. Effort to Breathe with Various Spontaneous Breathing Trial Techniques. A Physiologic Meta-analysis.

    Science.gov (United States)

    Sklar, Michael C; Burns, Karen; Rittayamai, Nuttapol; Lanys, Ashley; Rauseo, Michela; Chen, Lu; Dres, Martin; Chen, Guang-Qiang; Goligher, Ewan C; Adhikari, Neill K J; Brochard, Laurent; Friedrich, Jan O

    2017-06-01

    Spontaneous breathing trials (SBTs) are designed to simulate conditions after extubation, and it is essential to understand the physiologic impact of different methods. We conducted a systematic review and pooled measures reflecting patient respiratory effort among studies comparing SBT methods in a meta-analysis. We searched Medline, Excerpta Medica Database, and Web of Science from inception to January 2016 to identify randomized and nonrandomized clinical trials reporting physiologic measurements of respiratory effort (pressure-time product) or work of breathing during at least two SBT techniques. Secondary outcomes included the rapid shallow breathing index (RSBI), and effort measured before and after extubation. The quality of physiologic measurement and research design was appraised for each study. Outcomes were analyzed using ratio of means. Among 4,138 citations, 16 studies (n = 239) were included. Compared with T-piece, pressure support ventilation significantly reduced work by 30% (ratio of means [RoM], 0.70; 95% confidence interval [CI], 0.57-0.86), effort by 30% (RoM, 0.70; 95% CI, 0.60-0.82), and RSBI by 20% (RoM, 0.80; 95% CI, 0.75-0.86). Continuous positive airway pressure had significantly lower pressure-time product by 18% (RoM, 0.82; 95% CI, 0.68-0.999) compared with T-piece, and reduced RSBI by 16% (RoM, 0.84; 95% CI, 0.74-0.95). Studies comparing SBTs with the postextubation period demonstrated that pressure support induced significantly lower effort and RSBI; T-piece reduced effort, but not the work, compared with postextubation. Work, effort, and RSBI measured while intubated on the ventilator with continuous positive airway pressure of 0 cm H 2 O were no different than extubation. Pressure support reduces respiratory effort compared with T-piece. Continuous positive airway pressure of 0 cm H 2 O and T-piece more accurately reflect the physiologic conditions after extubation.

  8. Humidification performance of humidifying devices for tracheostomized patients with spontaneous breathing: a bench study.

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    Chikata, Yusuke; Oto, Jun; Onodera, Mutsuo; Nishimura, Masaji

    2013-09-01

    Heat and moisture exchangers (HMEs) are commonly used for humidifying respiratory gases administered to mechanically ventilated patients. While they are also applied to tracheostomized patients with spontaneous breathing, their performance in this role has not yet been clarified. We carried out a bench study to investigate the effects of spontaneous breathing parameters and oxygen flow on the humidification performance of 11 HMEs. We evaluated the humidification provided by 11 HMEs for tracheostomized patients, and also by a system delivering high-flow CPAP, and an oxygen mask with nebulizer heater. Spontaneous breathing was simulated with a mechanical ventilator, lung model, and servo-controlled heated humidifier at tidal volumes of 300, 500, and 700 mL, and breathing frequencies of 10 and 20 breaths/min. Expired gas was warmed to 37°C. The high-flow CPAP system was set to deliver 15, 30, and 45 L/min. With the 8 HMEs that were equipped with ports to deliver oxygen, and with the high-flow CPAP system, measurements were taken when delivering 0 and 3 L/min of dry oxygen. After stabilization we measured the absolute humidity (AH) of inspired gas with a hygrometer. AH differed among HMEs applied to tracheostomized patients with spontaneous breathing. For all the HMEs, as tidal volume increased, AH decreased. At 20 breaths/min, AH was higher than at 10 breaths/min. For all the HMEs, when oxygen was delivered, AH decreased to below 30 mg/L. With an oxygen mask and high-flow CPAP, at all settings, AH exceeded 30 mg/L. None of the HMEs provided adequate humidification when supplemental oxygen was added. In the ICU, caution is required when applying HME to tracheostomized patients with spontaneous breathing, especially when supplemental oxygen is required.

  9. The Lack, Magill and Bain anaesthetic breathing systems: a direct comparison in spontaneously-breathing anaesthetized adults.

    OpenAIRE

    Humphrey, D

    1982-01-01

    The performances of the Lack (Mapleson A), Magill (Mapleson A) and Bain (Mapleson D) anaesthetic breathing systems were compared in each of 20 anaesthetized adult patients breathing spontaneously with fresh gas flows of 70 ml kg-1 min-1. In every patient the Lack system caused the least rebreathing, as seen by the lowest inspired and end-expired CO2 tensions using capnography. The Magill caused more rebreathing than the Lack though less than the Bain. Comparative fresh gas flows for each syst...

  10. Time-varying respiratory system elastance: a physiological model for patients who are spontaneously breathing.

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    Chiew, Yeong Shiong; Pretty, Christopher; Docherty, Paul D; Lambermont, Bernard; Shaw, Geoffrey M; Desaive, Thomas; Chase, J Geoffrey

    2015-01-01

    Respiratory mechanics models can aid in optimising patient-specific mechanical ventilation (MV), but the applications are limited to fully sedated MV patients who have little or no spontaneously breathing efforts. This research presents a time-varying elastance (E(drs)) model that can be used in spontaneously breathing patients to determine their respiratory mechanics. A time-varying respiratory elastance model is developed with a negative elastic component (E(demand)), to describe the driving pressure generated during a patient initiated breathing cycle. Data from 22 patients who are partially mechanically ventilated using Pressure Support (PS) and Neurally Adjusted Ventilatory Assist (NAVA) are used to investigate the physiology relevance of the time-varying elastance model and its clinical potential. E(drs) of every breathing cycle for each patient at different ventilation modes are presented for comparison. At the start of every breathing cycle initiated by patient, E(drs) is 25 cmH2Os/l and thus can be used as an acute respiratory distress syndrome (ARDS) severity indicator. The E(drs) model captures unique dynamic respiratory mechanics for spontaneously breathing patients with respiratory failure. The model is fully general and is applicable to both fully controlled and partially assisted MV modes.

  11. Time-varying respiratory system elastance: a physiological model for patients who are spontaneously breathing.

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    Yeong Shiong Chiew

    Full Text Available BACKGROUND: Respiratory mechanics models can aid in optimising patient-specific mechanical ventilation (MV, but the applications are limited to fully sedated MV patients who have little or no spontaneously breathing efforts. This research presents a time-varying elastance (E(drs model that can be used in spontaneously breathing patients to determine their respiratory mechanics. METHODS: A time-varying respiratory elastance model is developed with a negative elastic component (E(demand, to describe the driving pressure generated during a patient initiated breathing cycle. Data from 22 patients who are partially mechanically ventilated using Pressure Support (PS and Neurally Adjusted Ventilatory Assist (NAVA are used to investigate the physiology relevance of the time-varying elastance model and its clinical potential. E(drs of every breathing cycle for each patient at different ventilation modes are presented for comparison. RESULTS: At the start of every breathing cycle initiated by patient, E(drs is 25 cmH2Os/l and thus can be used as an acute respiratory distress syndrome (ARDS severity indicator. CONCLUSION: The E(drs model captures unique dynamic respiratory mechanics for spontaneously breathing patients with respiratory failure. The model is fully general and is applicable to both fully controlled and partially assisted MV modes.

  12. Can a central blood volume deficit be detected by systolic pressure variation during spontaneous breathing?

    DEFF Research Database (Denmark)

    Dahl, Michael; Hayes, Chris; Steen Rasmussen, Bodil

    2016-01-01

    BACKGROUND: Whether during spontaneous breathing arterial pressure variations (APV) can detect a volume deficit is not established. We hypothesized that amplification of intra-thoracic pressure oscillations by breathing through resistors would enhance APV to allow identification of a reduced...... resistors. A brachial arterial catheter was used to measure blood pressure and thus systolic pressure variation (SPV), pulse pressure variation and stroke volume variation . Pulse contour analysis determined stroke volume (SV) and CO and we evaluated whether APV could detect a 10 % decrease in CO. RESULTS...... (from 21 (±15)% to 30 (±13)%). Yet during head-up tilt, a SPV ≥ 37 % predicted a decrease in CO ≥ 10 % with a sensitivity and specificity of 78 % and 100 %, respectively. CONCLUSION: In spontaneously breathing healthy volunteers combined inspiratory and expiratory resistors enhance SPV during head...

  13. Spontaneous breathing during anaesthesia: first, do no harm

    OpenAIRE

    Drummond, Gordon B

    2007-01-01

    Controlled respiration and mechanical ventilation have long been part of anaesthetic practice. Modern surgery, anaesthetic techniques, and new agents require a reappraisal of this established habit. In many circumstances the adverse effects of mechanical ventilation can be avoided by the use of the laryngeal mask and allowing spontaneous ventilation. In addition to the more prominent advantages, such as less sore throat, reliable assessment of anaesthetic depth, and good recovery, there may b...

  14. An expiratory assist during spontaneous breathing can compensate for endotracheal tube resistance.

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    Uchiyama, Akinori; Chang, Cheng; Suzuki, Shinya; Mashimo, Takashi; Fujino, Yuji

    2009-08-01

    Although inspiratory assist of spontaneous breathing in intubated patients is common, expiratory assist functions have rarely been reported. Effective expiratory support (ES) could be used to compensate for endotracheal tube (ETT) resistance during spontaneous breathing. In this study, we examined the performance of a new system designed to provide both inspiratory support (IS) and ES during spontaneous breathing with the goal of reducing the effective resistance of the ETT. The ES system consisted of a ventilator demand valve and a computer-controlled piston cylinder, which aspirated gas from the respiratory circuit during the expiratory phase. The movement of the piston was synchronized with spontaneous breathing. We compared the pressures at the tip of the ETT and in the breathing circuit during spontaneous breathing through an ETT of internal diameter (ID) 5 mm with that of an ETT with ID 8 mm in nine healthy adult male volunteers. The ventilatory mode was set to maintain a continuous airway pressure of 0 cm H(2)O. Three ventilator settings (no support, IS only, and IS plus ES) were compared using ID 5 mm ETT. We monitored pressure in the breathing circuit (P(aw)), ETT tip pressure (P(tip)), and respiratory flow. The P(tip) of the ID 5 mm ETT showed a large negative deflection during inspiration and a positive deflection during expiration without support. IS alone did not improve the respiratory pattern through the small ETT. However, IS plus ES resulted in negative P(aw) during expiration in addition to positive deflection of P(aw) during inspiration, making the pressure characteristics of P(tip) similar to those of ID 8 mm ETT. Moreover, IS plus ES produced a respiratory pattern through the ID 5 mm ETT that was similar to that through the ID 8 mm ETT. In this study of healthy volunteers, IS plus ES compensated for the airway resistance imposed by a ID 5.0 mm ETT to create pressure changes at the tip of the ETT similar to those of an ID 8.0 mm ETT.

  15. The Lack, Magill and Bain anaesthetic breathing systems: a direct comparison in spontaneously-breathing anaesthetized adults.

    Science.gov (United States)

    Humphrey, D

    1982-01-01

    The performances of the Lack (Mapleson A), Magill (Mapleson A) and Bain (Mapleson D) anaesthetic breathing systems were compared in each of 20 anaesthetized adult patients breathing spontaneously with fresh gas flows of 70 ml kg-1 min-1. In every patient the Lack system caused the least rebreathing, as seen by the lowest inspired and end-expired CO2 tensions using capnography. The Magill caused more rebreathing than the Lack though less than the Bain. Comparative fresh gas flows for each system at the point where rebreathing started to occur were examined in 10 further patients. The Lack system required approximately 51 ml kg-1 min-1, the Magill 72 ml kg-1 min-1 while the Bain required 153 ml kg-1 min-1. Of the three systems the Lack is concluded to be the most efficient and economical system for spontaneous respiration in adults, with the additional advantages of convenient access to the exhaust valve, easy scavenging and low expiratory resistance. In addition, it also offers many useful advantages over the circle absorber system. Images Figure 1. PMID:6806473

  16. [Nursing outcomes for ineffective breathing patterns and impaired spontaneous ventilation in intensive care].

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    do Canto, Débora Francisco; Almeida, Miriam de Abreu

    2013-12-01

    This study aimed to validate the results of Nursing selected from the link NANDA-I-NOC (Nursing Outcomes Classification--NANDA--International) for diagnosis Ineffective Breathing Pattern and Impaired Spontaneous Ventilation in adult intensive care unit. This is a content validation study conducted in a university hospital in southern Brazil with 15 expert nurses with clinical experience and knowledge of the ratings. The instruments contained five-point Likert scales to rate the importance of each outcome (1st step) and indicator (Step 2) for the diagnoses studied. We calculated weighted averages for each outcome/indicator, considering) 1 = 0. 2 = 0.25, 3 = 0.50 4 = 0.75 and 5 = 1. The outcomes suggested by the NOC with averages above 0.8 were considered validated as well as the indicators. The results Respiratory State--airway permeability (Ineffective Breathing Patterns) and 11 indicators, and Response to mechanical ventilation: adult (Impaired Spontaneous Ventilation) with 26 indicators were validated.

  17. In vitro evaluation of heat and moisture exchangers designed for spontaneously breathing tracheostomized patients.

    Science.gov (United States)

    Brusasco, Claudia; Corradi, Francesco; Vargas, Maria; Bona, Margherita; Bruno, Federica; Marsili, Maria; Simonassi, Francesca; Santori, Gregorio; Severgnini, Paolo; Kacmarek, Robert M; Pelosi, Paolo

    2013-11-01

    Heat and moisture exchangers (HMEs) are commonly used in chronically tracheostomized spontaneously breathing patients, to condition inhaled air, maintain lower airway function, and minimize the viscosity of secretions. Supplemental oxygen (O2) can be added to most HMEs designed for spontaneously breathing tracheostomized patients. We tested the efficiency of 7 HMEs designed for spontaneously breathing tracheostomized patients, in a normothermic model, at different minute ventilations (VE) and supplemental O2 flows. HME efficiency was evaluated using an in vitro lung model at 2 VE (5 and 15 L/min) and 4 supplemental O2 flows (0, 3, 6, and 12 L/min). Wet and dry temperatures of the inspiratory flow were measured, and absolute humidity was calculated. In addition, HME efficiency at 0, 12, and 24 h use was evaluated, as well as resistance to flow at 0 and 24 h. The progressive increase in O2 flow from 0 to 12 L/min was associated with a reduction in temperature and absolute humidity. Under the same conditions, this effect was greater at lower VE. The HME with the best performance provided an absolute humidity of 26 mg H2O/L and a temperature of 27.8 °C. No significant changes in efficiency or resistance were detected during the 24 h evaluation. The efficiency of HMEs in terms of temperature and absolute humidity is significantly affected by O2 supplementation and V(E).

  18. Comparison of trapezius squeeze test and jaw thrust as clinical indicators for laryngeal mask airway insertion in spontaneously breathing children

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    K K Dinesh Kumar

    2017-01-01

    Conclusion: Both JT and TPZ are equivalent clinical indicators in predicting the optimal conditions of LMA insertion in spontaneously breathing children; however, it takes a longer time to achieve a negative TPZ squeeze test.

  19. Respiratory variations in the photoplethysmographic waveform: acute hypovolaemia during spontaneous breathing is not detected

    International Nuclear Information System (INIS)

    Nilsson, Lena; Goscinski, Tomas; Lindenberger, Marcus; Länne, Toste; Johansson, Anders

    2010-01-01

    Recent studies using photoplethysmographic (PPG) signals from pulse oximeters have shown potential to assess hypovolaemia during spontaneous breathing. This signal is heavily filtered and reports are based on respiratory variations in the small pulse synchronous variation of PPG. There are stronger respiratory variations such as respiratory synchronous variation (PPGr) in the baseline of the unfiltered PPG signal. We hypothesized that PPGr would increase during hypovolaemia during spontaneous breathing. Hemodynamic and respiratory data were recorded together with PPG infrared signals from the finger, ear and forearm from 12 healthy male volunteers, at rest and during hypovolaemia created by the application of a lower body negative pressure (LBNP) of 15, 30 and 60 cmH 2 O. Hemodynamic and respiratory values changed significantly. From rest to the LBNP of 60 cmH 2 O systolic blood pressure fell from median (IQR) 116 (16) to 101 (23) mmHg, the heart rate increased from 58 (16) to 73 (16) beats min −1 , and the respiratory rate increased from 9.5 (2.0) to 11.5 (4.0) breaths min −1 . The amplitude of PPGr did not change significantly at any measurement site. The strongest effect was seen at the ear, where the LBNP of 60 cmH 2 O gave an amplitude increase from 1.0 (0.0) to 1.31 (2.24) AU. PPG baseline respiratory variations cannot be used for detecting hypovolaemia in spontaneously breathing subjects

  20. Whole body hyperthermia by extracorporeal circulation in spontaneously breathing sarcoma patients: hemodynamics and oxygen metabolism.

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    Locker, Gottfried J; Fuchs, Eva-Maria; Worel, Nina; Bojic, Andja; Heinrich, Gerhard; Brodowicz, Thomas; Clodi, Martin; Funk, Georg-Christian; Knöbl, Paul; Zielinski, Christoph C; Köstler, Wolfgang J

    2011-11-01

    This phase I study was performed to evaluate the feasibility and toxicity of a new method of extracorporeal perfusion-induced whole body hyperthermia (WBHT) in patients with advanced sarcoma avoiding the need of intubation and general anesthesia. One double-lumen femoral venous access was inserted by Seldinger's technique to obtain WBHT (41.8°C for 120 minutes) via an extracorporeal circuit. No concomitant chemotherapy was applied. Up to 4 treatments of WBHT were performed under moderate sedation in 6 spontaneously breathing patients. Invasive hemodynamic monitoring was performed by use of a pulmonary artery catheter. After their first WBHT session, 2 patients were excluded from further treatment due to transient liver toxicity or catheter-related complication, so a total of 12 cycles remained for analyses. In all patients, conscious sedation resulted in sufficient spontaneous respiration without the need for mandatory ventilation. Median time to reach the target temperature was 84 minutes (range 60-142). Hemodynamic changes revealed the expected hyperdynamic state: heart rate, cardiac index, and stroke volume index significantly increased (pmean; 0.062 µg·kg¹·min⁻¹) were necessary to maintain the mean arterial blood pressure >60 mmHg. Our data demonstrate the feasibility of this method of extracorporeal WBHT without mandatory ventilation. Hemodynamic side effects in spontaneously breathing patients during perfusion-induced WBHT seem less severe than those observed in radiant heat WBHT.

  1. The effects of passive humidifier dead space on respiratory variables in paralyzed and spontaneously breathing patients.

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    Campbell, R S; Davis, K; Johannigman, J A; Branson, R D

    2000-03-01

    Passive humidifiers have gained acceptance in the intensive care unit because of their low cost, simple operation, and elimination of condensate from the breathing circuit. However, the additional dead space of these devices may adversely affect respiratory function in certain patients. This study evaluates the effects of passive humidifier dead space on respiratory function. Two groups of patients were studied. The first group consisted of patients recovering from acute lung injury and breathing spontaneously on pressure support ventilation. The second group consisted of patients who were receiving controlled mechanical ventilation and were chemically paralyzed following operative procedures. All patients used 3 humidification devices in random order for one hour each. The devices were a heated humidifier (HH), a hygroscopic heat and moisture exchanger (HHME) with a dead space of 28 mL, and a heat and moisture exchanger (HME) with a dead space of 90 mL. During each measurement period the following were recorded: tidal volume, minute volume, respiratory frequency, oxygen consumption, carbon dioxide production, ratio of dead space volume to tidal volume (VD/VT), and blood gases. In the second group, intrinsic positive end-expiratory pressure was also measured. Addition of either of the passive humidifiers was associated with increased VD/VT. In spontaneously breathing patients, VD/VT increased from 59 +/- 13 (HH) to 62 +/- 13 (HHME) to 68 +/- 11% (HME) (p < 0.05). In these patients, constant alveolar ventilation was maintained as a result of increased respiratory frequency, from 22.1 +/- 6.6 breaths/min (HH) to 24.5 +/- 6.9 breaths/min (HHME) to 27.7 +/- 7.4 breaths/min (HME) (p < 0.05), and increased minute volume, from 9.1 +/- 3.5 L/min (HH) to 9.9 +/- 3.6 L/min (HHME) to 11.7 +/- 4.2 L/min (HME) (p < 0.05). There were no changes in blood gases or carbon dioxide production. In the paralyzed patient group, VD/VT increased from 54 +/- 12% (HH) to 56 +/- 10% (HHME

  2. Using an expiratory resistor, arterial pulse pressure variations predict fluid responsiveness during spontaneous breathing: an experimental porcine study.

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    Dahl, Michael K; Vistisen, Simon T; Koefoed-Nielsen, Jacob; Larsson, Anders

    2009-01-01

    Fluid responsiveness prediction is difficult in spontaneously breathing patients. Because the swings in intrathoracic pressure are minor during spontaneous breathing, dynamic parameters like pulse pressure variation (PPV) and systolic pressure variation (SPV) are usually small. We hypothesized that during spontaneous breathing, inspiratory and/or expiratory resistors could induce high arterial pressure variations at hypovolemia and low variations at normovolemia and hypervolemia. Furthermore, we hypothesized that SPV and PPV could predict fluid responsiveness under these conditions. Eight prone, anesthetized and spontaneously breathing pigs (20 to 25 kg) were subjected to a sequence of 30% hypovolemia, normovolemia, and 20% and 40% hypervolemia. At each volemic level, the pigs breathed in a randomized order either through an inspiratory and/or an expiratory threshold resistor (7.5 cmH2O) or only through the tracheal tube without any resistor. Hemodynamic and respiratory variables were measured during the breathing modes. Fluid responsiveness was defined as a 15% increase in stroke volume (DeltaSV) following fluid loading. Stroke volume was significantly lower at hypovolemia compared with normovolemia, but no differences were found between normovolemia and 20% or 40% hypervolemia. Compared with breathing through no resistor, SPV was magnified by all resistors at hypovolemia whereas there were no changes at normovolemia and hypervolemia. PPV was magnified by the inspiratory resistor and the combined inspiratory and expiratory resistor. Regression analysis of SPV or PPV versus DeltaSV showed the highest R2 (0.83 for SPV and 0.52 for PPV) when the expiratory resistor was applied. The corresponding sensitivity and specificity for prediction of fluid responsiveness were 100% and 100%, respectively, for SPV and 100% and 81%, respectively, for PPV. Inspiratory and/or expiratory threshold resistors magnified SPV and PPV in spontaneously breathing pigs during hypovolemia

  3. Ventilation and Haemodynamic Indicators in Spontaneously Breathing Pigs under General Anaesthesia

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    Jiří Kobr

    2010-01-01

    Full Text Available The aim of this study was to obtain ventilation and haemodynamic data of healthy piglets under general anaesthesia for future patho-physiological experimental studies. A total of 34 domestic piglets of the Czech Black Pied (Přeštice breed were used in the study. The animals (male to female ratio 8 : 9 were six weeks old and their average body mass was 22 kg. A general anaesthetic (fentanyl and azaperon was introduced via a pulmonary artery catheter and the spontaneously breathing animals were monitored for 60 min. Cardiac output and haemodynamic indicators were established using intermittent pulmonary artery thermodilution. Blood gas data were deduced using fan dynamic parameters of ventilation and ventilation indices. The study yielded reliable data of dynamic lung indicators (p 2O/kg, and haemodynamic indicators (p < 0.01 such as cardiac output 2.12 ± 0.75 l/min, pulmonary vascular resistance 3.92 ± 0.52 and systemic vascular resistance 15.8 ± 6.81 Woods units. Reliable data regarding lung dynamics, cardiac output, preload and afterload of both heart ventricles in spontaneously breathing healthy piglets under general anaesthesia were achieved.

  4. Spontaneous breathing test in the prediction of extubation failure in the pediatric population.

    Science.gov (United States)

    Nascimento, Milena Siciliano; Rebello, Celso Moura; Vale, Luciana Assis Pires Andrade; Santos, Érica; Prado, Cristiane do

    2017-01-01

    To assess whether the spontaneous breathing test can predict the extubation failure in pediatric population. A prospective and observational study that evaluated data of inpatients at the Pediatric Intensive Care Unit between May 2011 and August 2013, receiving mechanical ventilation for at least 24 hours followed by extubation. The patients were classified in two groups: Test Group, with patients extubated after spontaneous breathing test, and Control Group, with patients extubated without spontaneous breathing test. A total of 95 children were enrolled in the study, 71 in the Test Group and 24 in the Control Group. A direct comparison was made between the two groups regarding sex, age, mechanical ventilation time, indication to start mechanical ventilation and respiratory parameters before extubation in the Control Group, and before the spontaneous breathing test in the Test Group. There was no difference between the parameters evaluated. According to the analysis of probability of extubation failure between the two groups, the likelihood of extubation failure in the Control Group was 1,412 higher than in the Test Group, nevertheless, this range did not reach significance (p=0.706). This model was considered well-adjusted according to the Hosmer-Lemeshow test (p=0.758). The spontaneous breathing test was not able to predict the extubation failure in pediatric population. Avaliar se o teste de respiração espontânea pode ser utilizado para predizer falha da extubação na população pediátrica. Estudo prospectivo, observacional, no qual foram avaliados todos os pacientes internados no Centro de Terapia Intensiva Pediátrica, no período de maio de 2011 a agosto de 2013, que utilizaram ventilação mecânica por mais de 24 horas e que foram extubados. Os pacientes foram classificados em dois grupos: Grupo Teste, que incluiu os pacientes extubados depois do teste de respiração espontânea; e Grupo Controle, pacientes foram sem teste de respiração espont

  5. Coupled and reduced dimensional modeling of respiratory mechanics during spontaneous breathing.

    Science.gov (United States)

    Ismail, M; Comerford, A; Wall, W A

    2013-11-01

    In this paper, we develop a total lung model based on a tree of 0D airway and acinar models for studying respiratory mechanics during spontaneous breathing. This model utilizes both computer tomography-based geometries and artificially generated lobe-filling airway trees to model the entire conducting region of the lung. Beyond the conducting airways, we develop an acinar model, which takes into account the alveolar tissue resistance, compliance, and the intrapleural pressure. With this methodology, we compare four different 0D models of airway mechanics and determine the best model based on a comparison with a 3D-0D coupled model of the conducting airways; this methodology is possible because the majority of airway resistance is confined to the lower generations, that is, the trachea and the first few bronchial generations. As an example application of the model, we simulate the flow and pressure dynamics under spontaneous breathing conditions, that is, at flow conditions driven purely by pleural space pressure. The results show good agreement, both qualitatively and quantitatively, with reported physiological values. One of the key advantages of this model is the ability to provide insight into lung ventilation in the peripheral regions. This is often crucial because this is where information, specifically for studying diseases and gas exchange, is needed. Thus, the model can be used as a tool for better understanding local peripheral lung mechanics without excluding the upper portions of the lung. This tool will be also useful for in vitro investigations of lung mechanics in both health and disease. Copyright © 2013 John Wiley & Sons, Ltd.

  6. Spontaneous Breathing Trials and Conservative Sedation Practices Reduce Mechanical Ventilation Duration in Subjects With ARDS.

    Science.gov (United States)

    Kallet, Richard H; Zhuo, Hanjing; Yip, Vivian; Gomez, Antonio; Lipnick, Michael S

    2018-01-01

    Spontaneous breathing trials (SBTs) and daily sedation interruptions (DSIs) reduce both the duration of mechanical ventilation and ICU length of stay (LOS). The impact of these practices in patients with ARDS has not previously been reported. We examined whether implementation of SBT/DSI protocols reduce duration of mechanical ventilation and ICU LOS in a retrospective group of subjects with ARDS at a large, urban, level-1 trauma center. All ARDS survivors from 2002 to 2016 ( N = 1,053) were partitioned into 2 groups: 397 in the pre-SBT/DSI group (June 2002-December 2007) and 656 in the post-SBT/DSI group (January 2009-April 2016). Patients from 2008, during the protocol implementation period, were excluded. An additional SBT protocol database (2008-2010) was used to assess the efficacy of SBT in transitioning subjects with ARDS to unassisted breathing. Comparisons were assessed by either unpaired t tests or Mann-Whitney tests. Multiple comparisons were made using either one-way analysis of variance or Kruskal-Wallis and Dunn's tests. Linear regression modeling was used to determine variables independently associated with mechanical ventilation duration and ICU LOS; differences were considered statistically significant when P mechanical ventilation duration (14 [6-29] vs 9 [4-17] d, respectively, P mechanical ventilation duration and ICU LOS. Among subjects with ARDS in the SBT performance database, most achieved unassisted breathing with a median of 2 SBTs. Evidenced-based protocols governing weaning and sedation practices were associated with both reduced mechanical ventilation duration and ICU LOS in subjects with ARDS. However, higher respiratory system compliance in the SBT/DSI cohort also contributed to these improved outcomes. Copyright © 2018 by Daedalus Enterprises.

  7. Measurement of end-tidal carbon dioxide in spontaneously breathing children after cardiac surgery.

    Science.gov (United States)

    Rasera, Carmen Caroline; Gewehr, Pedro Miguel; Domingues, Adriana Maria Trevisan; Junior, Fernando Faria

    2011-09-01

    Respiratory monitoring is important after surgery to prevent pulmonary complications. End-tidal carbon dioxide (Petco(2)) measurement by capnometry is an indirect and noninvasive measurement of Pco(2) in blood and is accepted and recognized in critical care. To determine the correlation and level of agreement between Petco(2) and Paco(2) in spontaneously breathing children after cardiac surgery and to determine whether Petco(2) measured by using tidal volume (Vt-Petco(2)) or vital capacity (VC-Petco(2)) shows more or less significant correlation with Paco(2). Vt-Petco(2) and VC-Petco(2) by capnometry and Paco(2) by blood gas analysis were measured once a day after tracheal extubation. The determination coefficient and degree of bias between the methods were assessed in children with and without supplemental oxygen. A total of 172 Vt-Petco(2), VC-Petco(2), and Paco(2) values from 48 children were analyzed. The overall coefficients of determination were 0.84 (P breathing children, Vt-Petco(2) provided a more accurate estimate of Paco(2) than did VC-Petco(2), especially in children given little or no supplemental oxygen. The difference between the methods was significantly larger in the groups given 2 to 5 L of oxygen per minute.

  8. Model-based estimation of loop gain using spontaneous breathing: A validation study

    Science.gov (United States)

    Gederi, Elnaz; Nemati, Shamim; Edwards, Bradley A.; Clifford, Gari D.; Malhotra, Atul; Wellman, Andrew

    2014-01-01

    Non-invasive assessment of ventilatory control stability or loop gain (which is a key contributor in a number of sleep-related breathing disorders) has proven to be cumbersome. We present a novel multivariate autoregressive model that we hypothesize will enable us to make time-varying measurements of loop gain using nothing more than spontaneous fluctuations in ventilation and CO2. The model is adaptive to changes in the feedback control loop and therefore can account for system non-stationarities (e.g. changes in sleep state) and it is resistant to artifacts by using a signal quality measure. We tested this method by assessing its ability to detect a known increase in loop gain induced by proportional assist ventilation (PAV). Subjects were studied during sleep while breathing on continuous positive airway pressure (CPAP) alone (to stabilize the airway) or on CPAP + PAV. We show that the method tracked the PAV-induced increase in loop gain, demonstrating its time-varying capabilities, and it remained accurate in the face of measurement related artifacts. The model was able to detect a statistically significant increase in loop gain from 0.14 ± 10 on CPAP alone to 0.21 ± 0.13 on CPAP + PAV (p PAV-induced increase in loop gain was predominantly driven by an increase in controller gain. Taken together, these data provide compelling evidence for the validity of this technique. PMID:25038522

  9. Spontaneous breathing or mechanical ventilation alters lung compliance and tissue association of exogenous surfactant in preterm newborn rabbits.

    Science.gov (United States)

    Bohlin, Kajsa; Bouhafs, Rabea K L; Jarstrand, Connie; Curstedt, Tore; Blennow, Mats; Robertson, Bengt

    2005-05-01

    In preterm infants with respiratory distress syndrome, surfactant administration followed by immediate extubation to spontaneous breathing with nasal continuous positive airway pressure reduces the need for mechanical ventilation. With this treatment approach, repeated doses of surfactant are rarely indicated. We used a rabbit model to test the hypothesis that exogenous surfactant therapy followed by spontaneous breathing results in a more sustained initial treatment response compared with treatment followed by mechanical ventilation. Preterm rabbits (gestational age 28.5 d) were treated with pharyngeal deposition of 200 mg/kg radiolabeled surfactant (14C-Curosurf) and randomized to 4 h of spontaneous breathing or mechanical ventilation or to a control group, killed immediately after surfactant administration. With pharyngeal deposition, 46 +/- 10% (mean +/- SEM) of the administered surfactant reached the lungs. The dynamic lung-thorax compliance was higher in spontaneously breathing compared with mechanically ventilated animals (median, 9.9 and 0.75 ml x cm H2O(-1) x kg(-1), respectively; p mechanically ventilated animals (p mechanically ventilated animals. We conclude that the initial lung tissue association of exogenous surfactant is impaired by mechanical ventilation. This is associated with a reduction of dynamic compliance and evidence of increased surfactant inactivation.

  10. A nasal catheter for the measurement of end-tidal carbon dioxide in spontaneously breathing patients: a preliminary evaluation.

    Science.gov (United States)

    Raheem, Mohamed Samy Abdel; Wahba, Olaa M

    2010-04-01

    Several devices have been proposed to monitor end-tidal carbon dioxide tension (Petco(2)) in spontaneously breathing patients; however, many have been reported to be inaccurate. We designed this study to investigate the accuracy of a balloon-tipped nasal catheter in measuring Petco(2) in nontracheally intubated, spontaneously breathing patients. The catheter was assembled using a 14-F rubber Foley catheter, a tracheal tube pilot balloon, and the plastic sheath from an 18-gauge needle. The catheter was connected to the sampling tube of a gas analyzer. Petco(2) and Paco(2) were determined simultaneously in 20 otherwise healthy postsurgical patients while receiving oxygen. The mean Petco(2) - Paco(2) difference was -4.4 +/- 1.6 (SD) mm Hg with a correlation coefficient r = +0.87 (P breathing patients.

  11. Comparative study of minimal fresh gas flow used in Lack-Plus and Lack's circuit in spontaneously breathing anesthetized adults.

    Science.gov (United States)

    Theerapongpakdee, Sunchai; Sathitkarnmanee, Thepakorn; Tribuddharat, Sirirat; Sucher, Siwalai; Thananun, Maneerat; Nonlhaopol, Duangthida

    2016-01-01

    The Lack's circuit is a co-axial Mapleson A breathing system commonly used in spontaneously breathing anesthetized adults but still requires high fresh gas flow (FGF). The Lack-Plus circuit was invented with the advantage of lower FGF requirement. The authors compared the Lack-Plus and Lack's circuit for the minimal FGF requirement with no rebreathing in spontaneously breathing anesthetized adults. This was a randomized crossover study. We enrolled 24 adult patients undergoing supine elective surgery, with a body mass index ≤30 kg/m 2 and an American Society of Anesthesiologists physical status I-II. They were randomly allocated to group 1 (LP-L) starting with Lack-Plus then switching to Lack's circuit or group 2 (L-LP) (with the reverse pattern). After induction and intubation, anesthesia was maintained with 50% N 2 O/O 2 and desflurane (4%-6%) plus fentanyl titration to maintain an optimal respiratory rate between 10 and 16/min. Starting with the first circuit, all the patients were spontaneously breathing with a FGF of 4 L/min for 10 min, gradually decreased by 0.5 L/min every 5 min until FGF was 2.5 L/min. End-tidal CO 2 , inspired minimum CO 2 (ImCO 2 ), mean arterial pressure, and oxygen saturation were recorded until rebreathing (ImCO 2 >0 mmHg) occurred. The alternate anesthesia breathing circuit was used and the measurements were repeated. The respective minimal FGF at the point of rebreathing for the Lack-Plus and Lack's circuit was 2.7±0.8 and 3.3±0.5 L/min, respectively, p Lack-Plus circuit can be used safely and effectively, and it requires less FGF than Lack's circuit in spontaneously breathing anesthetized adults.

  12. Spontaneous sleep-like brain state alternations and breathing characteristics in urethane anesthetized mice.

    Directory of Open Access Journals (Sweden)

    Silvia Pagliardini

    Full Text Available Brain state alternations resembling those of sleep spontaneously occur in rats under urethane anesthesia and they are closely linked with sleep-like respiratory changes. Although rats are a common model for both sleep and respiratory physiology, we sought to determine if similar brain state and respiratory changes occur in mice under urethane. We made local field potential recordings from the hippocampus and measured respiratory activity by means of EMG recordings in intercostal, genioglossus, and abdominal muscles. Similar to results in adult rats, urethane anesthetized mice displayed quasi-periodic spontaneous forebrain state alternations between deactivated patterns resembling slow wave sleep (SWS and activated patterns resembling rapid eye movement (REM sleep. These alternations were associated with an increase in breathing rate, respiratory variability, a depression of inspiratory related activity in genioglossus muscle and an increase in expiratory-related abdominal muscle activity when comparing deactivated (SWS-like to activated (REM-like states. These results demonstrate that urethane anesthesia consistently induces sleep-like brain state alternations and correlated changes in respiratory activity across different rodent species. They open up the powerful possibility of utilizing transgenic mouse technology for the advancement and translation of knowledge regarding sleep cycle alternations and their impact on respiration.

  13. Effects of ultraprotective ventilation, extracorporeal carbon dioxide removal, and spontaneous breathing on lung morphofunction and inflammation in experimental severe acute respiratory distress syndrome.

    Science.gov (United States)

    Güldner, Andreas; Kiss, Thomas; Bluth, Thomas; Uhlig, Christopher; Braune, Anja; Carvalho, Nadja; Quast, Theresa; Rentzsch, Ines; Huhle, Robert; Spieth, Peter; Richter, Torsten; Saddy, Felipe; Rocco, Patricia R M; Kasper, Michael; Koch, Thea; Pelosi, Paolo; de Abreu, Marcelo Gama

    2015-03-01

    To investigate the role of ultraprotective mechanical ventilation (UP-MV) and extracorporeal carbon dioxide removal with and without spontaneous breathing (SB) to improve respiratory function and lung protection in experimental severe acute respiratory distress syndrome. Severe acute respiratory distress syndrome was induced by saline lung lavage and mechanical ventilation (MV) with higher tidal volume (VT) in 28 anesthetized pigs (32.8 to 52.5 kg). Animals (n = 7 per group) were randomly assigned to 6 h of MV (airway pressure release ventilation) with: (1) conventional P-MV with VT ≈6 ml/kg (P-MVcontr); (2) UP-MV with VT ≈3 ml/kg (UP-MVcontr); (3) UP-MV with VT ≈3 ml/kg and SB (UP-MVspont); and (4) UP-MV with VT ≈3 ml/kg and pressure supported SB (UP-MVPS). In UP-MV groups, extracorporeal carbon dioxide removal was used. The authors found that: (1) UP-MVcontr reduced diffuse alveolar damage score in dorsal lung zones (median[interquartile]) (12.0 [7.0 to 16.8] vs. 22.5 [13.8 to 40.8]), but worsened oxygenation and intrapulmonary shunt, compared to P-MVcontr; (2) UP-MVspont and UP-MVPS improved oxygenation and intrapulmonary shunt, and redistributed ventilation towards dorsal areas, as compared to UP-MVcontr; (3) compared to P-MVcontr, UP-MVcontr and UP-MVspont, UP-MVPS yielded higher levels of tumor necrosis factor-α (6.9 [6.5 to 10.1] vs. 2.8 [2.2 to 3.0], 3.6 [3.0 to 4.7] and 4.0 [2.8 to 4.4] pg/mg, respectively) and interleukin-8 (216.8 [113.5 to 343.5] vs. 59.8 [45.3 to 66.7], 37.6 [18.8 to 52.0], and 59.5 [36.1 to 79.7] pg/mg, respectively) in dorsal lung zones. In this model of severe acute respiratory distress syndrome, MV with VT ≈3 ml/kg and extracorporeal carbon dioxide removal without SB slightly reduced lung histologic damage, but not inflammation, as compared to MV with VT = 4 to 6 ml/kg. During UP-MV, pressure supported SB increased lung inflammation.

  14. [Usefulness of monitoring anaesthesia with the bispectral index in upper gastrointestinal endoscopies with spontaneous breathing].

    Science.gov (United States)

    Alados-Arboledas, F J; Millán-Bueno, M P; Expósito-Montes, J F; Santiago-Gutierrez, C; Arévalo-Garrido, A; Pérez-Parras, A; Millán-Miralles, L; Martínez-Padilla, M C; de la Cruz-Moreno, J

    2013-08-01

    The objective of this investigation is to determine whether bispectral index (BIS®) monitoring during intravenous anaesthesia with spontaneous breathing for upper gastrointestinal endoscopy (UGE) in a pediatric population is useful for: a) decreasing the amount of drug, b) decreasing the time for awakening, and c) improving patient safety. A quasi-experimental case-control prospective study was conducted in the setting of a second level hospital pediatric intensive care unit. Children aged 1-13 years. ASA I patient who needed a diagnostic UGE; eligible, 36, participants, 30. historical cohort of patients who needed UGE (years 2008-2010): 50 patients. UGE performed with anaesthetic protocol, vital signs monitoring, sedation level (Ramsay scale) and BIS monitoring. propofol total dose (mg/kg), induction time, time in performing the UGE, awakening time (min); initial BIS (iBIS), and BIS during the UGE; adverse effects. There were no significant differences in sex, age or weight between case (B) and control (C) population. No significant differences in total propofol doses: (B 4.9 ± 1.4 mg/kg; C 5.2 ± 1.6 mg/kg, P=.492), awakening time (B 12.2 ± 4.6 min; C 12.8 ± 4.4 min, P=.402), time for execution of UGE (B 9.5 ± 4.8 min; C 11.3 ± 6.5 min, P=.335) and induction time (B 11.1 ± 2.6 min; C 10.1 ± 4.2 min, P=.059), iBIS 55.4 ± 6.9. There were no significant differences in adverse effects: 2 patients suffered from mild desaturation in the control group. BIS monitoring for diagnostic UGE in spontaneous breathing in a pediatric population is feasible, but does not appear to decrease awakening time or the amount of propofol needed. Furthermore, there was no statistically significant decrease in the number of adverse effects. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  15. Manual versus target-controlled infusion remifentanil administration in spontaneously breathing patients.

    Science.gov (United States)

    Moerman, Annelies T; Herregods, Luc L; De Vos, Martine M; Mortier, Eric P; Struys, Michel M R F

    2009-03-01

    The combination of propofol-remifentanil for procedural deep sedation in spontaneously breathing patients is characterized by the frequent incidence of side effects, especially respiratory depression. These side effects may be due to either the drug combination or the drug delivery technique. Target-controlled infusion (TCI) might optimize drug delivery. In this prospective, randomized, double-blind study in patients undergoing elective colonoscopy, we thus tried to answer two questions: first, if adding remifentanil to propofol surpasses the disadvantages of the combination of these two products, and second, if administration of remifentanil via TCI decreases the incidence of side effects, compared to manually controlled administration. Patients undergoing elective colonoscopy were randomly assigned to receive remifentanil via manually controlled continuous infusion (MCI) (0.125 microg x kg(-1) x min(-1) for 2 min followed by a continuous infusion of 0.05 microg x kg(-1) x min(-1)), TCI remifentanil (1 ng/mL), or placebo (normal saline either as TCI or manual infusion of equivalent rate). All patients received TCI propofol, adjusted to a target concentration level that provided deep sedation in which patients were not responsive to verbal commands, but maintained spontaneous ventilation without assistance. Significantly more patients in the placebo group showed movement, cough and hiccup, which transiently interfered with the examination. There were no clinically significant differences in hemodynamic or recovery variables among all groups. Remifentanil administered via TCI resulted in a decrease in propofol requirements. The incidence of hypopnea and apnea was less frequent when remifentanil was administered via TCI compared to MCI (TCI n = 7, MCI n = 16, P n = 7, MCI n = 16, P < 0.05), compared to manually controlled administration of remifentanil.

  16. Breathing

    Science.gov (United States)

    ... smaller structures called bronchi. The process of breathing (respiration) is divided into two distinct phases, inspiration (inhalation) and expiration (exhalation). During inspiration, the diaphragm contracts and pulls downward while the muscles between the ribs contract and pull upward. This ...

  17. Less invasive surfactant administration is associated with improved pulmonary outcomes in spontaneously breathing preterm infants.

    Science.gov (United States)

    Göpel, Wolfgang; Kribs, Angela; Härtel, Christoph; Avenarius, Stefan; Teig, Norbert; Groneck, Peter; Olbertz, Dirk; Roll, Claudia; Vochem, Matthias; Weller, Ursula; von der Wense, Axel; Wieg, Christian; Wintgens, Jürgen; Preuss, Michael; Ziegler, Andreas; Roth, Bernhard; Herting, Egbert

    2015-03-01

    Providing less invasive surfactant administration (LISA) to spontaneously breathing preterm infants has been reported to reduce mechanical ventilation and bronchopulmonary dysplasia (BPD) in randomised controlled trials. This large cohort study compared these outcome measures between LISA-treated infants and controls. Infants receiving LISA, who were born before 32 gestational weeks and enrolled in the German Neonatal Network, were matched to control infants by gestational age, umbilical cord pH, Apgar-score at 5 min, small for gestational age status, antenatal treatment with steroids, gender and highest supplemental oxygen during the first 12 h of life. Outcome data were compared with chi-square and Mann-Whitney U-tests and adjusted for multiple comparisons. Between 2009 and 2012, 1103 infants were treated with LISA at 37 centres. LISA infants had lower rates of mechanical ventilation (41% versus 62%, p mechanical ventilation and BPD. Additional large-scale randomised controlled trials are needed to assess the possible long-term benefits of LISA. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  18. Analysis of ineffective breathing pattern and impaired spontaneous ventilation of adults with oxygen therapy 1

    Science.gov (United States)

    Seganfredo, Deborah Hein; Beltrão, Beatriz Amorim; da Silva, Viviane Martins; Lopes, Marcos Venícios de Oliveira; Castro, Stela Maris de Jezus; Almeida, Miriam de Abreu

    2017-01-01

    ABSTRACT Objective: to analyze the manifestation of the defining characteristics of the nursing diagnoses of ineffective breathing pattern and impaired spontaneous ventilation, of the NANDA International and the defining characteristics identified in the literature for the concept of “ventilation” in adult patients hospitalized in an intensive care unit with use of oxygen therapy. Method: clinical diagnostic validation study, conducted with 626 patients in intensive care using oxygen therapy, in three different modalities. Multiple correspondence analysis was used to verify the discriminative capacity of the defining characteristics and latent class analysis to determine the diagnostic accuracy of them, based on the severity level defined by the ventilatory mode used. Results: in the multiple correspondence analysis, it was demonstrated that the majority of the defining characteristics presented low discriminative capacity and low percentage of explained variance for the two dimensions (diagnoses). Latent class models, separately adjusted for the two diagnoses, presented a worse fit, with sharing of some defining characteristics. Models adjusted by level of severity (ventilation mode) presented better fit and structure of the component defining characteristics. Conclusion: clinical evidence obtained in the present study seems to demonstrate that the set of defining characteristics of the two nursing diagnoses studied fit better in a single construct. PMID:29211196

  19. Transcutaneous carbon dioxide monitoring in spontaneously breathing, nonintubated patients in the early postoperative period.

    Science.gov (United States)

    Fanelli, G; Baciarello, M; Squicciarini, G; Malagutti, G; Zasa, M; Casati, A

    2008-01-01

    The authors investigated the accuracy of transcutaneous capnometry (TcPCO(2)) in estimating arterial blood carbon dioxide partial pressure (PaCO(2)) during spontaneous breathing in patients admitted to our surgical intensive care unit (ICU). Serial TcPCO(2) and PaCO(2) measurements were taken in stable patients undergoing postoperative monitoring after major abdominal, vascular, or thoracic surgery. Patients were enrolled 12 hours after extubation. Exclusion criteria were pulmonary dysfunction, hemodynamic instability, or anemia. Linear regression, mixed models, and Bland-Altman analyses were used to compare accuracy and correlation between the two variables. Data are presented as means (95% confidence intervals). PaCO(2) values ranged between 26 mmHg and 52 mmHg. Mean values for TcPCO(2) and PaCO(2) were 35.3 (33.8-36.8) mmHg and 39.2 (37.6-40.7) (Pbreathing, nonintubated patients in the early postoperative period.

  20. Analysis of ineffective breathing pattern and impaired spontaneous ventilation of adults with oxygen therapy

    Directory of Open Access Journals (Sweden)

    Deborah Hein Seganfredo

    2017-12-01

    Full Text Available ABSTRACT Objective: to analyze the manifestation of the defining characteristics of the nursing diagnoses of ineffective breathing pattern and impaired spontaneous ventilation, of the NANDA International and the defining characteristics identified in the literature for the concept of “ventilation” in adult patients hospitalized in an intensive care unit with use of oxygen therapy. Method: clinical diagnostic validation study, conducted with 626 patients in intensive care using oxygen therapy, in three different modalities. Multiple correspondence analysis was used to verify the discriminative capacity of the defining characteristics and latent class analysis to determine the diagnostic accuracy of them, based on the severity level defined by the ventilatory mode used. Results: in the multiple correspondence analysis, it was demonstrated that the majority of the defining characteristics presented low discriminative capacity and low percentage of explained variance for the two dimensions (diagnoses. Latent class models, separately adjusted for the two diagnoses, presented a worse fit, with sharing of some defining characteristics. Models adjusted by level of severity (ventilation mode presented better fit and structure of the component defining characteristics. Conclusion: clinical evidence obtained in the present study seems to demonstrate that the set of defining characteristics of the two nursing diagnoses studied fit better in a single construct.

  1. Quantifying Aerosol Delivery in Simulated Spontaneously Breathing Patients With Tracheostomy Using Different Humidification Systems With or Without Exhaled Humidity.

    Science.gov (United States)

    Ari, Arzu; Harwood, Robert; Sheard, Meryl; Alquaimi, Maher Mubarak; Alhamad, Bshayer; Fink, James B

    2016-05-01

    Aerosol and humidification therapy are used in long-term airway management of critically ill patients with a tracheostomy. The purpose of this study was to determine delivery efficiency of jet and mesh nebulizers combined with different humidification systems in a model of a spontaneously breathing tracheotomized adult with or without exhaled heated humidity. An in vitro model was constructed to simulate a spontaneously breathing adult (tidal volume, 400 mL; breathing frequency, 20 breaths/min; inspiratory-expiratory ratio, 1:2) with a tracheostomy using a teaching manikin attached to a test lung through a collecting filter (Vital Signs Respirgard II). Exhaled heat and humidity were simulated using a cascade humidifier set to deliver 37°C and >95% relative humidity. Albuterol sulfate (2.5 mg/3 mL) was administered with a jet nebulizer (AirLife Misty Max) operated at 10 L/min and a mesh nebulizer (Aeroneb Solo) using a heated pass-over humidifier, unheated large volume humidifier both at 40 L/min output and heat-and-moisture exchanger. Inhaled drug eluted from the filter was analyzed via spectrophotometry (276 nm). Delivery efficiency of the jet nebulizer was less than that of the mesh nebulizer under all conditions (P humidity decreased drug delivery up to 44%. The jet nebulizer was less efficient than the mesh nebulizer in all conditions tested in this study. Aerosol deposition with each nebulizer was lowest with the heated humidifier with high flow. Exhaled humidity reduced inhaled dose of drug compared with a standard model with nonheated/nonhumidified exhalation. Further clinical research is warranted to understand the impact of exhaled humidity on aerosol drug delivery in spontaneously breathing patients with tracheostomy using different types of humidifiers. Copyright © 2016 by Daedalus Enterprises.

  2. An evaluation of fresh gas flow rates for spontaneously breathing cats and small dogs on the Humphrey ADE semi-closed breathing system.

    Science.gov (United States)

    Gale, Elizabeth; Ticehurst, Kim E; Zaki, Sanaa

    2015-05-01

    To evaluate the fresh gas flow (FGF) rate requirements for the Humphrey ADE semi-closed breathing system in the Mapleson A mode; to determine the FGF at which rebreathing occurs, and compare the efficiency of this system to the Bain (Mapleson D) system in spontaneously breathing cats and small dogs. Prospective clinical study. Twenty-five healthy (ASA score I or II) client-owned cats and dogs (mean ± SD age 4.7 ± 5.0 years, and body weight 5.64 ± 3.26 kg) undergoing elective surgery or minor procedures. Anaesthesia was maintained with isoflurane delivered via the Humphrey ADE system in the A mode using an oxygen FGF of 100 mL kg(-1) minute(-1). The FGF was then reduced incrementally by 5-10 mL kg(-1) minute(-1) at approximately five-minute intervals, until rebreathing (inspired CO(2) >5 mmHg (0.7 kPa)) was observed, after which flow rates were increased. In six animals, once the minimum FGF at which rebreathing occurred was found, the breathing system was changed to the Bain, and the effects of this FGF delivery examined, before FGF was increased. Rebreathing did not occur at the FGF recommended by the manufacturer for the ADE. The mean ± SD FGF that resulted in rebreathing was 60 ± 20 mL kg(-1) minute(-1). The mean minimum FGF at which rebreathing did not occur with the ADE was 87 ± 39 mL kg(-1) minute(-1). This FGF resulted in significant rebreathing (inspired CO(2) 8.8 ± 2.6 mmHg (1.2 ± 0.3 kPa)) on the Bain system. The FGF rates recommended for the Humphrey ADE are adequate to prevent rebreathing in spontaneously breathing cats and dogs cats and small dogs. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

  3. Use of an Impedance Threshold Device in Spontaneously Breathing Patients with Hypotension Secondary to Trauma: An Observational Cohort Feasibility Study

    Science.gov (United States)

    2014-09-09

    hypotension due to multiple causes ; the patients of primary interest experienced a traumatic injury. Upon determination of hypotension (systolic blood...to vasovagal syncope , dehydration, and renal dialysis; (3) provide a treatment of right- sided heart failure after myocardial infarction; and (4...Research, the ITD has been used for treat- ment of hypotension due to multiple causes in spontaneously breathing patients.6,9 The US Army is specifically

  4. Comparison of Size 2 LMA-ProSeal™ and LMA-Supreme™ in Spontaneously Breathing Children: a Randomised Clinical Trial

    OpenAIRE

    Arslan, Zehra İpek; Balcı, Canan; Oysu, Duygu Akalın; Yılmaz, Mehmet; Gürbüz, Necla; İlce, Zekeriya

    2013-01-01

    Objective: The aim of this study was to compare size 2 Laryngeal Mask Airway ProSeal and size 2 Laryngeal Mask Airway Supreme in spontaneously breathing children undergoing lower abdominal elective surgery of <1 hour duration. Study Design: Randomized clinical trial. Material and Methods: Sixty children aged 1-7 years, weighing 10-20 kg, ASA I physical status were randomly allocated to the Laryngeal Mask Airway ProSeal and Laryngeal Mask Airway Supreme. Results: There w...

  5. Extracorporeal Carbon Dioxide Removal Enhanced by Lactic Acid Infusion in Spontaneously Breathing Conscious Sheep.

    Science.gov (United States)

    Scaravilli, Vittorio; Kreyer, Stefan; Belenkiy, Slava; Linden, Katharina; Zanella, Alberto; Li, Yansong; Dubick, Michael A; Cancio, Leopoldo C; Pesenti, Antonio; Batchinsky, Andriy I

    2016-03-01

    The authors studied the effects on membrane lung carbon dioxide extraction (VCO2ML), spontaneous ventilation, and energy expenditure (EE) of an innovative extracorporeal carbon dioxide removal (ECCO2R) technique enhanced by acidification (acid load carbon dioxide removal [ALCO2R]) via lactic acid. Six spontaneously breathing healthy ewes were connected to an extracorporeal circuit with blood flow 250 ml/min and gas flow 10 l/min. Sheep underwent two randomly ordered experimental sequences, each consisting of two 12-h alternating phases of ALCO2R and ECCO2R. During ALCO2R, lactic acid (1.5 mEq/min) was infused before the membrane lung. Caloric intake was not controlled, and animals were freely fed. VCO2ML, natural lung carbon dioxide extraction, total carbon dioxide production, and minute ventilation were recorded. Oxygen consumption and EE were calculated. ALCO2R enhanced VCO2ML by 48% relative to ECCO2R (55.3 ± 3.1 vs. 37.2 ± 3.2 ml/min; P less than 0.001). During ALCO2R, minute ventilation and natural lung carbon dioxide extraction were not affected (7.88 ± 2.00 vs. 7.51 ± 1.89 l/min, P = 0.146; 167.9 ± 41.6 vs. 159.6 ± 51.8 ml/min, P = 0.063), whereas total carbon dioxide production, oxygen consumption, and EE rose by 12% each (223.53 ± 42.68 vs. 196.64 ± 50.92 ml/min, 215.3 ± 96.9 vs. 189.1 ± 89.0 ml/min, 67.5 ± 24.0 vs. 60.3 ± 20.1 kcal/h; P less than 0.001). ALCO2R was effective in enhancing VCO2ML. However, lactic acid caused a rise in EE that made ALCO2R no different from standard ECCO2R with respect to ventilation. The authors suggest coupling lactic acid-enhanced ALCO2R with active measures to control metabolism.

  6. Successful protocol of anaesthesia for measuring transepithelial nasal potential difference in spontaneously breathing mice.

    Science.gov (United States)

    Leal, T; Lebacq, J; Vanbinst, R; Lederman, Ch; De Kock, M; Wallemacq, P

    2006-01-01

    Numerous difficulties arise during in vivo measurements of transepithelial nasal potential difference (PD) in mice, such as inadequate duration and depth of anaesthesia, bronchoaspiration of solutions perfused in the nose, and respiratory and/or cardiovascular depression. Anaesthesia was induced in adult C57 mice with intraperitoneal injection of a combination of fentanyl, droperidol and medetomidine, each of these at either a small dose (0.20, 10 and 0.33 mg/kg, respectively) or at a large dose (0.40, 20 and 0.40 mg/kg, respectively), combined with a fixed dose of 0.375 microg clonidine. In order to establish a pharmacokinetic-pharmacodynamic relationship, blood concentrations of the first three drugs were measured in 24 animals by liquid-chromatography tandem mass spectrometry. At the end of the experiment, naloxone, a competitive morphinic antagonist, and atipamezole, an alpha-2 adrenergic antagonist, were administered. Bronchoaspiration was prevented by tilting the animal head downwards and by absorbing the excess fluid from the opposite nostril and from the oral cavity. Optimal assessment of anaesthesia associated with regular respiration, loss of blink, pupillary and pedal withdrawal reflexes was obtained with doses of fentanyl, droperidol and medetomidine corresponding to 0.20, 20 and 0.40 mg/kg, respectively. Blood concentrations of fentanyl around 17 ng/mL induced loss of respiratory efforts and were followed by death during the experiment. Integrity of ion transport was demonstrated under continuous perfusion by successive depolarization after amiloride and repolarization after chloride-free solution. The combination investigated in this study lead to adequate surgical anaesthesia (stage III, plane 2) for prolonged nasal PD measurements in spontaneously breathing mice.

  7. Comparison of objective methods to classify the pattern of respiratory sinus arrhythmia during mechanical ventilation and paced spontaneous breathing

    International Nuclear Information System (INIS)

    Carvalho, N C; Beda, A; Granja-Filho, P; Jandre, F C; Giannella-Neto, A; De Abreu, M G; Spieth, P M

    2009-01-01

    Respiratory sinus arrhythmia (RSA) is a fluctuation of heart period that occurs during a respiratory cycle. It has been suggested that inspiratory heart period acceleration and expiratory deceleration during spontaneous ventilation (henceforth named positive RSA) improve the efficiency of gas exchange compared to the absence or the inversion of such a pattern (negative RSA). During mechanical ventilation (MV), for which maximizing the efficiency of gas exchange is of critical importance, the pattern of RSA is still the object of debate. In order to gain a better insight into this matter, we compared five different methods of RSA classification using the data of five mechanically ventilated piglets. The comparison was repeated using the data of 15 volunteers undergoing a protocol of paced spontaneous breathing, which is expected to result in a positive RSA pattern. The results showed that the agreement between the employed methods is limited, suggesting that the lack of a consensus about the RSA pattern during MV is, at least in part, of methodological origin. However, independently of the method used, the pattern of RSA within the respiratory cycle was not consistent among the subjects and conditions of MV considered. Also, the outcomes showed that even during paced spontaneous breathing a negative RSA pattern might be present, when a low respiratory frequency is imposed

  8. Heart rate variability and stroke volume variability to detect central hypovolemia during spontaneous breathing and supported ventilation in young, healthy volunteers

    International Nuclear Information System (INIS)

    Elstad, Maja; Walløe, Lars

    2015-01-01

    Cardiovascular oscillations exist in many different variables and may give important diagnostic and prognostic information in patients. Variability in cardiac stroke volume (SVV) is used in clinical practice for diagnosis of hypovolemia, but currently is limited to patients on mechanical ventilation. We investigated if SVV and heart rate variability (HRV) could detect central hypovolemia in spontaneously breathing humans: We also compared cardiovascular variability during spontaneous breathing with supported mechanical ventilation.Ten subjects underwent simulated central hypovolemia by lower body negative pressure (LBNP) with >10% reduction of cardiac stroke volume. The subjects breathed spontaneously and with supported mechanical ventilation. Heart rate, respiratory frequency and mean arterial blood pressure were measured. Stroke volume (SV) was estimated by ModelFlow (Finometer). Respiratory SVV was calculated by: 1) SVV% = (SVmax − SVmin)/SVmean during one respiratory cycle, 2) SVIntegral from the power spectra (Fourier transform) at 0.15–0.4 Hz and 3) SVV-norm = (√SVIntegral)/SVmean. HRV was calculated by the same methods.During spontaneous breathing two measures of SVV and all three measures of HRV were reduced during hypovolemia compared to baseline. During spontaneous breathing SVIntegral and HRV% were best to detect hypovolemia (area under receiver operating curve 0.81). HRV% ≤ 11% and SVIntegral ≤ 12 ml 2 differentiated between hypovolemia and baseline during spontaneous breathing.During supported mechanical ventilation, none of the three measures of SVV changed and two of the HRV measures were reduced during hypovolemia. Neither measures of SVV nor HRV were classified as a good detector of hypovolemia.We conclude that HRV% and SVIntegral detect hypovolemia during spontaneous breathing and both are candidates for further clinical testing. (paper)

  9. Airway management in spontaneously breathing anaesthetized children: comparison of the Laryngeal Mask Airway with the cuffed oropharyngeal airway.

    Science.gov (United States)

    Mamaya, Biruta

    2002-06-01

    The efficacy and safety of the smallest size of the cuffed oropharyngeal airway (COPA) for school age, spontaneously breathing children was investigated and compared with the Laryngeal Mask Airway (LMA). Seventy children of school age (7-16 years) were divided into two groups: the COPA (n=35) and the LMA (n=35). Induction was with propofol i.v. or halothane, nitrous oxide, oxygen and fentanyl. After depression of laryngopharyngeal reflexes, a COPA size 8 cm or an LMA was inserted. Ventilation was manually assisted until spontaneous breathing was established. For maintenance, propofol i.v. and fentanyl or halothane with nitrous oxide were used. Local anaesthesia or peripheral blocks were also used. Both extratracheal airways had a highly successful insertion rate, but more positional manoeuvres to achieve a satisfactory airway were required with the COPA, 28.6% versus LMA 2.9%. The need to change the method of airway management was higher (8.6%) in the COPA group. After induction, the need for assisted ventilation was higher in the LMA group 54.3% versus 20% in the COPA group. Airway reaction to cuff inflation was higher in the LMA group 14.3% versus COPA 5.7%. Problems during surgery were similar, except continuous chin support to establish an effective airway was more frequent (11.4%) in the COPA group. In the postoperative period, blood on the device and incidence of sore throat were detected less in the COPA group. The COPA is a good extratracheal airway that provides new possibilities for airway management in school age children with an adequate and well sealed airway, during spontaneous breathing or during short-term assisted manual ventilation.

  10. Extracorporeal Gas Exchange and Spontaneous Breathing for the Treatment of Acute Respiratory Distress Syndrome: An Alternative to Mechanical Ventilation?

    Science.gov (United States)

    2014-03-01

    Alveolar minute ventilation (L/min) 5.7 ± 2.7 2.7 ± 1.5 0.003 Dead space fraction 0.44 ± 0.10 0.81 ± 0.10 < 0.001 Pulmonary shunt fraction 0.01 ± 0.01 0.25...ventilation expressed as % of control values, MVALV reduction = reduction in alveolar minute ventilation expressed as percentage of control values...Data are expressed as mean ± sd. Online Laboratory Investigations Critical Care Medicine www.ccmjournal.org e217 of spontaneous breathing: preserved

  11. Tracheostomy as a bridge to spontaneous breathing and awake-ECMO in non-transplant surgical patients.

    Science.gov (United States)

    Swol, J; Strauch, J T; Schildhauer, T A

    2017-05-01

    The tracheostomy is a frequently used procedure for the respiratory weaning of ventilated patients allows sedation free ECLS use in awake patient. The aim of this study is to assess the possibility and highlight the benefits of lowering the impact of sedation in surgical non-transplant patients on ECLS. The specific objective was to investigate the use of tracheostomy as a bridge to spontaneous breathing on ECLS. Of the 95 patients, 65 patients received a tracheostomy, and 5 patients were admitted with a tracheostoma. One patient was cannulated without intubation, one is extubated during ECLS course after 48 hours. 4 patients were extubated after weaning and the removal of ECLS. 19 patients died before the indication to tracheostomy was given. Tracheostomy can bridge to spontaneous breathing and awake-ECMO in non-transplant surgical patients. The "awake ECMO" strategy may avoid complications related to mechanical ventilation, sedation, and immobilization and provide comparable outcomes to other approaches for providing respiratory support. © 2017 The Authors. European Journal of Heart Failure © 2017 European Society of Cardiology.

  12. Comparison of Size 2 LMA-ProSeal™ and LMA-Supreme™ in Spontaneously Breathing Children: a Randomised Clinical Trial

    Directory of Open Access Journals (Sweden)

    Zehra İpek Arslan

    2013-03-01

    Full Text Available Objective: The aim of this study was to compare size 2 Laryngeal Mask Airway ProSeal and size 2 Laryngeal Mask Airway Supreme in spontaneously breathing children undergoing lower abdominal elective surgery of <1 hour duration. Study Design: Randomized clinical trial. Material and Methods: Sixty children aged 1-7 years, weighing 10-20 kg, ASA I physical status were randomly allocated to the Laryngeal Mask Airway ProSeal and Laryngeal Mask Airway Supreme. Results: There were no differences in demographic variables, ease of gastric tube placement, ease of insertion and ventilation, number of insertion attempts, hemodynamic changes on insertion, postoperative complications and bloodstaining between the groups. Gastric insufflation was detected and gastric tube was placed in all patients except one in LMA Supreme. Postoperative cuff volumes were comparable with the preoperative values in group itself. Oropharyngeal leak pressures were higher in Laryngeal Mask Airway ProSeal (24.6±5.5 vs 21.3±4.2, respectively; p<0.01. Conclusion: As a result Laryngeal Mask Airway ProSeal and Laryngeal Mask Airway Supreme can safely be used in spontaneously breathing pediatric population undergoing lower abdominal elective surgery.

  13. Albuterol Delivery via Facial and Tracheostomy Route in a Model of a Spontaneously Breathing Child.

    Science.gov (United States)

    Cooper, Brandy; Berlinski, Ariel

    2015-12-01

    Some pediatric patients receiving therapeutic aerosols undergo tracheostomy, and others who are tracheostomized continue requiring inhaled therapies upon decannulation. It is unknown whether a dose adjustment is required. Different devices are available for facial and tracheostomy delivery, and in some instances, the assisted technique is used. We hypothesized that the change from face mask to tracheostomy would result in a decrease in the lung dose. A breathing simulator connected in series to a filter holder and an anatomically correct head model of a child was used. The drug captured in the filter was termed the lung dose. Breathing patterns with tidal volumes of 50, 155, and 300 mL were tested. Albuterol hydrofluoroalkane (pressurized metered-dose inhaler [pMDI]) with an AeroChamber Mini (face and 4.5-mm tracheostomy), AeroTrach (4.5-mm tracheostomy), and AeroChamber (face) and albuterol (2.5 mg/3 mL) with a continuous output nebulizer (face and 4.5-mm tracheostomy) were tested. Masks were used for facial delivery. Four units of each device were tested. Particle size of the pMDI was measured by cascade impaction. Albuterol concentration was determined via spectrophotometry (276 nm). Switching from facial to tracheostomy delivery increased lung dose with nebulizer (all breathing patterns). When a pMDI was used, lung dose was unchanged or increased for the 50- and 155-mL and decreased for the 300-mL breathing pattern. The use of the assisted technique increased lung dose only during nebulization with the 300-mL breathing pattern. The particle size of the pMDI decreased by 19-23% when traveling through the tracheostomy tube, which retained tracheostomy was variable and depended on the delivery device and the breathing pattern. There is no advantage of using the assisted technique to enhance aerosol delivery. Copyright © 2015 by Daedalus Enterprises.

  14. Can transcutaneous carbon dioxide pressure be a surrogate of blood gas samples for spontaneously breathing emergency patients? The ERNESTO experience.

    Science.gov (United States)

    Peschanski, Nicolas; Garcia, Léa; Delasalle, Emilie; Mzabi, Lynda; Rouff, Edwin; Dautheville, Sandrine; Renai, Fayrouz; Kieffer, Yann; Lefevre, Guillaume; Freund, Yonathan; Ray, Patrick

    2016-05-01

    It is known that the arterial carbon dioxide pressure (PaCO2) is useful for emergency physicians to assess the severity of dyspnoeic spontaneously breathing patients. Transcutaneous carbon dioxide pressure (PtcCO2) measurements could be a non-invasive alternative to PaCO2 measurements obtained by blood gas samples, as suggested in previous studies. This study evaluates the reliability of a new device in the emergency department (ED). We prospectively included patients presenting to the ED with respiratory distress who were breathing spontaneously or under non-invasive ventilation. We simultaneously performed arterial blood gas measurements and measurement of PtcCO2 using a sensor placed either on the forearm or the side of the chest and connected to the TCM4 CombiM device. The agreement between PaCO2 and PtcCO2 was assessed using the Bland-Altman method. Sixty-seven spontaneously breathing patients were prospectively included (mean age 70 years, 52% men) and 64 first measurements of PtcCO2 (out of 67) were analysed out of the 97 performed. Nineteen patients (28%) had pneumonia, 19 (28%) had acute heart failure and 19 (28%) had an exacerbation of chronic obstructive pulmonary disease. Mean PaCO2 was 49 mm Hg (range 22-103). The mean difference between PaCO2 and PtcCO2 was 9 mm Hg (range -47 to +54) with 95% limits of agreement of -21.8 mm Hg and 39.7 mm Hg. Only 36.3% of the measurement differences were within 5 mm Hg. Our results show that PtcCO2 measured by the TCM4 device could not replace PaCO2 obtained by arterial blood gas analysis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  15. Agreement between values for arterial and end-tidal partial pressures of carbon dioxide in spontaneously breathing, critically ill dogs.

    Science.gov (United States)

    Kelmer, Efrat; Scanson, Lindsey C; Reed, Ann; Love, Lydia C

    2009-12-01

    To determine agreement between arterial partial pressures of carbon dioxide (PaCO(2)) and end-tidal partial pressures of carbon dioxide (PETCO(2)) measured with a nasal catheter in spontaneously breathing, critically ill dogs. Validation study. 26 client-owned dogs admitted to an intensive care unit for various conditions. PaCO(2) was measured with a commercial blood gas analyzer, and PETCO(2) was measured with a sidestream capnograph attached to a nasal catheter. Measurements were obtained twice (ie, with and without supplemental oxygen). Paired values were compared by means of the Pearson correlation method. Level of agreement was assessed by means of the Bland-Altman method. Mean difference between PaCO(2) and PETCO(2) when dogs did not receive supplemental oxygen (mean +/- SD, 3.95 +/- 4.92 mm Hg) was significantly lower than mean difference when dogs did receive supplemental oxygen (6.87 +/- 6.42 mm Hg). Mean difference in dogs with a condition affecting the respiratory system (8.55 +/- 5.43 mm Hg) was significantly higher than mean difference in dogs without respiratory tract disease (3.28 +/- 3.23 mm Hg). There was a significant linear correlation and good agreement between measured values of PaCO(2) and PETCO(2). Catheter size, ventilatory status, and outcome were not significantly associated with mean difference between PaCO(2) and PETCO(2). Results suggested that nasal capnography is a clinically relevant method of estimating PaCO(2) in spontaneously breathing, critically ill dogs, but that values should be interpreted with caution in dogs receiving supplemental oxygen and in dogs with conditions affecting the respiratory system.

  16. Imposed Work of Breathing and Breathing Comfort of Nonintubated Volunteers Breathing with Three Portable Ventilators and a Critical Care Ventilator

    National Research Council Canada - National Science Library

    Austin, Paul

    2001-01-01

    .... The purpose of this study was to assess the imposed inspiratory work of breathing and breathing comfort of nonintubated healthy volunteers breathing spontaneously through three portable ventilators...

  17. Delivery of helium–oxygen mixture during spontaneous breathing: evaluation of three high-concentration face masks.

    Science.gov (United States)

    Roche-Campo, Ferran; Vignaux, Laurence; Galia, Fabrice; Lyazidi, Aissam; Vargas, Frédéric; Texereau, Joëlle; Apiou-Sbirlea, Gabriela; Jolliet, Philippe; Brochard, Laurent

    2011-11-01

    To evaluate the efficacy of delivering a mixture of helium and oxygen gas (He–O2) in spontaneous ventilation. Three high oxygen flow reservoir masks were tested: the Heliox21, specifically designed for helium; the Hi-Ox80 mask, with an inspiratory and an expiratory valve; and a standard high-concentration face mask. This prospective randomized crossover study was performed in six healthy volunteers in a laboratory setting. Volunteers breathed a mixture of 78% He/22% O2 through each of the masks under two different breathing conditions (rest and hyperventilation: minute ventilation of 14.9 ± 6.1 and 26.7 ± 8.7 L min(−1), respectively) and four different He–O2 flow rates (7, 10, 12, and 15 L min(−1)). A nasopharyngeal catheter was used to estimate He pharyngeal concentration (Fp [He]) in the airways in order to determine the percentage of contamination with room air (% air cont) at end-expiration. Under all testing conditions, the Hi-Ox80 mask presented a significantly lower % air cont. During resting breathing pattern, a Fp [He] higher than 50% was achieved in 54% of the tests performed with the Hi-Ox80 mask compared to 29% for the Heliox21 mask and only 17% for the standard mask. At hyperventilation, a Fp [He] higher than 50% was achieved in 17% of the tests performed with the Hi-Ox mask compared to 4% for the other two masks. He–O2 administration via the usual high-concentration reservoir masks results in significant dilution by room air. The Hi-Ox80 mask minimized room air contamination and much more frequently achieved a pharyngeal He concentration higher than 50%.

  18. Can baroreflex measurements with spontaneous sequence analysis be improved by also measuring breathing and by standardization of filtering strategies?

    International Nuclear Information System (INIS)

    Hollow, M R; Parkes, M J; Clutton-Brock, T H

    2011-01-01

    Baroreflex sensitivity (BRS) is known to be attenuated by inspiration and all the original BRS methodologies took this into account by measuring only in expiration. Spontaneous sequence analysis (SSA) is a non-invasive clinical tool widely used to estimate BRS in Man but does not take breathing into account. We have therefore modified it to test whether it too can detect inspiratory attenuation. Traditional SSA is also entangled with issues of distinguishing causal from random relationships between blood pressure and heart period and of the optimum choice of data filter settings. We have also tested whether the sequences our modified SSA rejects do behave as random relationships and show the limitations of the absence of filter standardization. SSA was performed on eupneic data from 1 h periods in 20 healthy subjects. Applying SSA traditionally produced a mean BRS of 23 ± 3 ms mmHg −1 . After modification to measure breathing, SSA detected significant inspiratory attenuation (11 ± 1 ms mmHg −1 ), and the mean expiratory BRS was significantly higher (26 ± 5 ms mmHg −1 ). Traditional SSA therefore underestimates BRS by an amount (3 ms mmHg −1 ) as big as the major physiological and clinical factors known to alter BRS. We show that the sequences rejected by SSA do behave like random associations between pressure and period. We also show the minimal effect of the r 2 filter and the biases that some pressure and heart period filters can introduce. We discuss whether SSA might be improved by standardization of filter settings and by also measuring breathing

  19. The reliability and validity of passive leg raise and fluid bolus to assess fluid responsiveness in spontaneously breathing emergency department patients

    DEFF Research Database (Denmark)

    Duus, Nicolaj; Shogilev, Daniel J; Skibsted, Simon

    2015-01-01

    PURPOSE: We investigated the reproducibility of passive leg raise (PLR) and fluid bolus (BOLUS) using the Non-Invasive Cardiac Output Monitor (NICOM; Cheetah Medical, Tel Aviv, Israel) for assessment of fluid responsiveness (FR) in spontaneously breathing emergency department (ED) patients. METHO...

  20. Comparative study of minimal fresh gas flow used in Lack-Plus and Lack’s circuit in spontaneously breathing anesthetized adults

    Directory of Open Access Journals (Sweden)

    Theerapongpakdee S

    2016-11-01

    Full Text Available Sunchai Theerapongpakdee, Thepakorn Sathitkarnmanee, Sirirat Tribuddharat, Siwalai Sucher, Maneerat Thananun, Duangthida Nonlhaopol Department of Anesthesiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand Background: The Lack’s circuit is a co-axial Mapleson A breathing system commonly used in spontaneously breathing anesthetized adults but still requires high fresh gas flow (FGF. The Lack-Plus circuit was invented with the advantage of lower FGF requirement. The authors compared the Lack-Plus and Lack’s circuit for the minimal FGF requirement with no rebreathing in spontaneously breathing anesthetized adults.Methods: This was a randomized crossover study. We enrolled 24 adult patients undergoing supine elective surgery, with a body mass index ≤30 kg/m2 and an American Society of Anesthesiologists physical status I–II. They were randomly allocated to group 1 (LP-L starting with Lack-Plus then switching to Lack’s circuit or group 2 (L-LP (with the reverse pattern. After induction and intubation, anesthesia was maintained with 50% N2O/O2 and desflurane (4%–6% plus fentanyl titration to maintain an optimal respiratory rate between 10 and 16/min. Starting with the first circuit, all the patients were spontaneously breathing with a FGF of 4 L/min for 10 min, gradually decreased by 0.5 L/min every 5 min until FGF was 2.5 L/min. End-tidal CO2, inspired minimum CO2 (ImCO2, mean arterial pressure, and oxygen saturation were recorded until rebreathing (ImCO2 >0 mmHg occurred. The alternate anesthesia breathing circuit was used and the measurements were repeated.Results: The respective minimal FGF at the point of rebreathing for the Lack-Plus and Lack’s circuit was 2.7±0.8 and 3.3±0.5 L/min, respectively, p<0.001. At an FGF of 2.5 L/min, the respective ImCO2 was 1.5±2.0 and 4.2±2.6 mmHg, respectively, p<0.001.Conclusion: The Lack-Plus circuit can be used safely and effectively, and it requires less FGF than Lack

  1. Aerosol delivery during spontaneous breathing with different types of nebulizers- in vitro/ex vivo models evaluation.

    Science.gov (United States)

    Lin, Hui-Ling; Fang, Tien-Pei; Cho, Hui-Sun; Wan, Gwo-Hwa; Hsieh, Meng-Jer; Fink, James B

    2018-02-01

    Nebulizers for spontaneous breathing have been evaluated through different study designs. There are limitations in simulated bench models related to patient and nebulizer factors. The aim of this study was to determine the correlation of inhaled drug mass between in vitro and ex vivo studies by testing aerosol deposition of various types of nebulizers. Ten healthy subjects were recruited to receive aerosol therapy with five nebulizers in random order: 1) a jet nebulizer (JN); 2) a breath-enhanced nebulizer (BEN); 3) a manually triggered nebulizer (MTN), 4) a breath-actuated nebulizer (BAN), and 5) a vibrating mesh nebulizer (VMN) with valved-adapter. A unit dose of salbutamol containing 5 mg in 2.5 mL was placed into the nebulizer and administered for 10 min. For the ex vivo study, minute ventilation of healthy subjects was recorded for 1 min. For the in vitro study a breathing simulator was utilized with adult breathing patterns. Aerosolized drug from the nebulizers and the accessory tubes was captured using inspiratory and expiratory collecting filters. Captured drug was eluted, measured and expressed as inhaled and exhaled mass using spectrophotometry at a wavelength of 276 nm. 10 healthy subjects were recruited, aged 20.8 ± 0.7 years old, with a mean height of 166.2 ± 9.2 cm and weight of 64.7 ± 12.4 kg. There was no significant difference in the inhaled drug dose between the JN and BEN (15.0 ± 1.94% and 17.74 ± 2.65%, respectively, p = .763), yet the inhaled doses were lower than the other three nebulizers (p vivo model (44.0 ± 0.9% and 35.5 ± 6.3% respectively, p = .003), whereas the JN in the ex vivo model resulted in a greater inhaled drug dose (15.0 ± 1.9% for ex vivo vs 11.6 ± 1.6% for in vitro, p = .008). These in vitro/ex vivo model comparisons of nebulizers performance indicated that breath-related nebulizers can be estimated using an in vitro model; however, the JN and VMN delivered

  2. [Is there an appropriate bispectral index for upper gastrointestinal endoscopy in spontaneous breathing in the pediatric patient?].

    Science.gov (United States)

    Alados-Arboledas, F J; Millán-Bueno, M P; Expósito-Montes, J F; Arévalo-Garrido, A; Pérez-Parras, A; de la Cruz-Moreno, J

    2015-03-01

    The bispectral index (BIS) values that predict appropriate anesthetic level to perform an upper gastrointestinal endoscopy in spontaneous breathing are not well established in Pediatrics. The objective of this study is to determine whether it is possible to find an appropriate, less profound, BIS level in the pediatric patient that would enable an upper gastrointestinal endoscopy (UGE) to be performed in spontaneous breathing without causing gag reflex or motor response. A prospective study was designed and included 61 patients from 12-167 months old, and an ASAI-II who needed a diagnostic UGE. The study was conducted from October 2011 to March 2013. UGE performed with an anesthetic protocol using propofol. The vital signs measured were heart and respiratory rate, pulse oximetry, non-invasive blood pressure. The sedation level score (Ramsay scale) and BIS values were also measured. The first attempt was performed at BIS level 60-69, and this was not feasible, then the anesthetic was deepened and a second attempt made at BIS level 50-59. If this was still not possible a deeper anesthetic level was then achieved and a third attempt made at BIS level 45-49. Variables of interest were: effective BIS level (eBIS), BIS level at which UGE was performed without gag reflex or motor response; propofol total dose (mgkg(-1)), induction time (time from onset of sedation to effective start of UGE). A logistic regression analysis was performed to obtain an equation to estimate the possibility of UGE success. The distribution of the patient was: male 40%, female 60%, with 11 (18%) patients under 36 months. The statistical values are expressed as mean and standard deviation, with following results; age (months): 95.9±45.86; weight (kg): 30.5±14.68; effective BIS: 56.41±4.63; induction time (minutes): 11.07±2.69; total propofol dose (per kg): 4.86±1.21. An additional intra-procedure propofol bolus was given in 38 patients (62%), with 7/38 of them (18%) due to movement, and 31

  3. Typical patterns of expiratory flow and carbon dioxide in mechanically ventilated patients with spontaneous breathing.

    Science.gov (United States)

    Rees, S E; Larraza, S; Dey, N; Spadaro, S; Brohus, J B; Winding, R W; Volta, C A; Karbing, D S

    2017-08-01

    Incomplete expiration of tidal volume can lead to dynamic hyperinflation and auto-PEEP. Methods are available for assessing these, but are not appropriate for patients with respiratory muscle activity, as occurs in pressure support. Information may exist in expiratory flow and carbon dioxide measurements, which, when taken together, may help characterize dynamic hyperinflation. This paper postulates such patterns and investigates whether these can be seen systematically in data. Two variables are proposed summarizing the number of incomplete expirations quantified as a lack of return to zero flow in expiration (IncExp), and the end tidal CO 2 variability (varETCO 2 ), over 20 breaths. Using these variables, three patterns of ventilation are postulated: (a) few incomplete expirations (IncExp  18) and small varETCO 2 . IncExp and varETCO 2 were calculated from data describing respiratory flow and CO 2 signals in 11 patients mechanically ventilated at 5 levels of pressure support. Data analysis showed that the three patterns presented systematically in the data, with periods of IncExp  18 having significantly lower variability in end-tidal CO 2 than periods with 2 ≤ IncExp ≤ 18 (p  18 to 2 ≤ IncExp ≤ 18 results in significant, rapid, change in the variability of end-tidal CO 2 p < 0.05. This study illustrates that systematic patterns of expiratory flow and end-tidal CO 2 are present in patients in supported mechanical ventilation, and that changes between these patterns can be identified. Further studies are required to see if these patterns characterize dynamic hyperinflation. If so, then their combination may provide a useful addition to understanding the patient at the bedside.

  4. Respiratory pattern and rebreathing in the Mapleson A, C and D breathing systems with spontaneous ventilation. A theory.

    Science.gov (United States)

    Cook, L B

    1996-04-01

    A theoretical analysis is presented of the Mapleson A, C and D breathing systems when used in spontaneous respiration. The influence of the respiratory pattern is explained diagrammatically. Simple equations are derived, predicting the fresh gas flow required to prevent rebreathing with different respiratory patterns. Further equations allow the degree of rebreathing caused by inadequate fresh gas flow to be quantified. These are used to examine the effects of different respiratory patterns on the efficiency of the three systems. It is demonstrated that the single most important determinant of efficiency is the duration of the expiratory pause. The nature of the inspiratory and expiratory waveforms is less important and the I:E ratio far less important. The analysis suggests that the Mapleson A system will always be the most efficient of the three systems. The Mapleson C system will be efficient if inspiration is long and the expiratory pause is minimal. The Mapleson D system will be efficient if the expiratory pause is sufficiently long.

  5. Comparison of trapezius squeeze test and jaw thrust as clinical indicators for laryngeal mask airway insertion in spontaneously breathing children.

    Science.gov (United States)

    Dinesh Kumar, K K; Bhardwaj, Neerja; Yaddanapudi, Sandhya

    2017-01-01

    It is not known whether trapezius squeeze test (TPZ) is a better clinical test than jaw thrust (JT) to assess laryngeal mask airway (LMA) insertion conditions in children under sevoflurane anesthesia. After the Institutional Ethics Committee approval and written informed parental consent, 124 American Society of Anesthesiologists I and II children of 2-8 years of age undergoing minor surgical procedures were randomized into TPZ and JT groups. The children were induced with 8% sevoflurane in oxygen at a fresh gas flow of 4 L/min. TPZ or JT was performed after 1 min of start of sevoflurane and then every 20 s till the test was negative, when end-tidal (ET) sevoflurane concentration was noted. Classic LMA of requisite size was inserted by a blinded anesthetist and conditions at the insertion of LMA, insertion time, and the number of attempts of LMA insertion were recorded. The mean LMA insertion time was significantly longer ( P insertion was comparable in the two groups. LMA insertion conditions were similar in the two groups. There was no difference between the two groups regarding total number of attempts of LMA insertion. Heart rate (HR) decreased in both groups after LMA insertion ( P insertion ( P = 0.03). Both JT and TPZ are equivalent clinical indicators in predicting the optimal conditions of LMA insertion in spontaneously breathing children; however, it takes a longer time to achieve a negative TPZ squeeze test.

  6. Combination of intravenous dexmedetomidine with topicalization of airway for placement of double lumen tube in a spontaneously breathing patient of giant lung bullae

    Directory of Open Access Journals (Sweden)

    Vikas Karne

    2016-10-01

    Here we present a patient with giant lung bulla in left lower lobe with severely reduced pulmonary reserves and significant air-trapping posted for VAT assisted bullectomy. Anaesthesia challenges including pathological changes, its effects during induction of anaesthesia, and issues related to placement of double lumen tube in a spontaneously breathing patient are discussed with possible advantages of dexmedetomidine in this special group of patients.

  7. Randomised Comparison of the AMBU AuraOnce Laryngeal Mask and the LMA Unique Laryngeal Mask Airway in Spontaneously Breathing Adults

    OpenAIRE

    Williams, Daryl Lindsay; Zeng, James M.; Alexander, Karl D.; Andrews, David T.

    2012-01-01

    We conducted a randomised single-blind controlled trial comparing the LMA-Unique (LMAU) and the AMBU AuraOnce (AMBU) disposable laryngeal mask in spontaneously breathing adult patients undergoing general anaesthesia. Eighty-two adult patients (ASA status I–IV) were randomly allocated to receive the LMAU or AMBU and were blinded to device selection. Patients received a standardized anesthetic and all airway devices were inserted by trained anaesthetists. Size selection was guided by manufactur...

  8. Comparative study of minimal fresh gas flow used in Lack-Plus and Lack’s circuit in spontaneously breathing anesthetized adults

    Science.gov (United States)

    Theerapongpakdee, Sunchai; Sathitkarnmanee, Thepakorn; Tribuddharat, Sirirat; Sucher, Siwalai; Thananun, Maneerat; Nonlhaopol, Duangthida

    2016-01-01

    Background The Lack’s circuit is a co-axial Mapleson A breathing system commonly used in spontaneously breathing anesthetized adults but still requires high fresh gas flow (FGF). The Lack-Plus circuit was invented with the advantage of lower FGF requirement. The authors compared the Lack-Plus and Lack’s circuit for the minimal FGF requirement with no rebreathing in spontaneously breathing anesthetized adults. Methods This was a randomized crossover study. We enrolled 24 adult patients undergoing supine elective surgery, with a body mass index ≤30 kg/m2 and an American Society of Anesthesiologists physical status I–II. They were randomly allocated to group 1 (LP-L) starting with Lack-Plus then switching to Lack’s circuit or group 2 (L-LP) (with the reverse pattern). After induction and intubation, anesthesia was maintained with 50% N2O/O2 and desflurane (4%–6%) plus fentanyl titration to maintain an optimal respiratory rate between 10 and 16/min. Starting with the first circuit, all the patients were spontaneously breathing with a FGF of 4 L/min for 10 min, gradually decreased by 0.5 L/min every 5 min until FGF was 2.5 L/min. End-tidal CO2, inspired minimum CO2 (ImCO2), mean arterial pressure, and oxygen saturation were recorded until rebreathing (ImCO2 >0 mmHg) occurred. The alternate anesthesia breathing circuit was used and the measurements were repeated. Results The respective minimal FGF at the point of rebreathing for the Lack-Plus and Lack’s circuit was 2.7±0.8 and 3.3±0.5 L/min, respectively, p<0.001. At an FGF of 2.5 L/min, the respective ImCO2 was 1.5±2.0 and 4.2±2.6 mmHg, respectively, p<0.001. Conclusion The Lack-Plus circuit can be used safely and effectively, and it requires less FGF than Lack’s circuit in spontaneously breathing anesthetized adults. PMID:27877068

  9. Development, implementation, and evaluation of an institutional daily awakening and spontaneous breathing trial protocol: a quality improvement project.

    Science.gov (United States)

    Kher, Sucharita; Roberts, Russel J; Garpestad, Erik; Kunkel, Chris; Howard, William; Didominico, Dorothy; Fergusson, Anne; Devlin, John W

    2013-01-01

    While one controlled trial found that a daily awakening and spontaneous breathing trial (DA-SBT) decreases time on mechanical ventilation (MV), there is a paucity of real-world data surrounding the development, implementation, and impact of DA-SBT protocols. We describe a multidisciplinary process improvement effort in 2, 10-bed medical intensive care units (MICUs) at a 330-bed academic medical center that focused on the development, implementation, and evaluation of a new DA-SBT protocol. A DA-SBT protocol, developed using results from a nursing survey literature and available institutional resources, was implemented after extensive clinician education and institution of quality reminders to boost use. Postprotocol compliance was evaluated. Use of sedation, DA and SBT practices, and clinical outcomes were retrospectively compared between the before and after DA-SBT protocol groups (ie, consecutive MICU patients requiring a continuously infused sedative [CIS] ≥24 hours). In the after group (n = 32), the DA and SBT compliances were 44% and 84%, respectively. Compared with the before group (n = 33), after group patients received CIS on fewer days of MV (100% vs 67%, P = .003) and had their CIS down-titrated by ≥25% on more days of CIS (40% vs 71%, P = .006). Neither total CIS dose (P = .49), total MV days (P = .75), days of MV where a SBT occurred (P = .38), nor episodes of self-extubation (15% vs 6%, P = .43) differed between the 2 groups. Despite the implementation of a DA-SBT protocol that was individualized to clinician preferences and institutional resources and accompanied by substantial education and reminders for use, compliance to the DA component of this protocol was low and duration of MV remained unchanged. Additional quality improvement strategies are needed to overcome barriers to DA-SBT protocol use that may not exist in controlled clinical trials.

  10. A novel approach using time-frequency analysis of pulse-oximeter data to detect progressive hypovolemia in spontaneously breathing healthy subjects.

    Science.gov (United States)

    Selvaraj, Nandakumar; Shelley, Kirk H; Silverman, David G; Stachenfeld, Nina; Galante, Nicholas; Florian, John P; Mendelson, Yitzhak; Chon, K

    2011-08-01

    Accurate and early detection of blood volume loss would greatly improve intraoperative and trauma care. This study has attempted to determine early diagnostic and quantitative markers for blood volume loss by analyzing photoplethysmogram (PPG) data from ear, finger and forehead sites with our high-resolution time-frequency spectral (TFS) technique in spontaneously breathing healthy subjects (n = 11) subjected to lower body negative pressure (LBNP). The instantaneous amplitude modulations present in heart rate (AM HR) and breathing rate (AMBR) band frequencies of PPG signals were calculated from the high-resolution TFS. Results suggested that the changes (P signals, respectively. The mean percent increase in AMBR values at 100% LBNP tolerance was 99.4% and 19.6% for ear and finger sites, respectively; AMBR values were not attainable for forehead PPG signal. Even without baseline AMHR values, our results suggest that hypovolemia detection is possible with specificity and sensitivity greater than 90% for the ear and forehead locations when LBNP tolerance is 100%. Therefore, the TFS analysis of noninvasive PPG waveforms is promising for early diagnosis and quantification of hypovolemia at levels not identified by vital signs in spontaneously breathing subjects.

  11. Spontaneous breathing trial in T-tube negatively impact on autonomic modulation of heart rate compared with pressure support in critically ill patients.

    Science.gov (United States)

    Güntzel Chiappa, Adriana M; Chiappa, Gaspar R; Cipriano, Gerson; Moraes, Ruy S; Ferlin, Elton L; Borghi-Silva, Audrey; Vieira, Silvia R

    2017-07-01

    Spontaneous breathing with a conventional T-piece (TT) connected to the tracheal tube orotraqueal has been frequently used in clinical setting to weaning of mechanical ventilation (MV), when compared with pressure support ventilation (PSV). However, the acute effects of spontaneous breathing with TT versus PSV on autonomic function assessed through heart rate variability (HRV) have not been fully elucidated. The purpose of this study was to examine the acute effects of spontaneous breathing in TT vs PSV in critically ill patients. Twenty-one patients who had received MV for ≥ 48 h and who met the study inclusion criteria for weaning were assessed. Eligible patients were randomized to TT and PSV. Cardiorespiratory responses (respiratory rate -ƒ, tidal volume-V T , mean blood pressure (MBP) and diastolic blood pressure (DBP), end tidal dioxide carbone (P ET CO 2 ), peripheral oxygen saturation (SpO 2 ) and HRV indices in frequency domain (low-LF, high frequency (HF) and LF/HF ratio were evaluated. TT increased ƒ (20 ± 5 vs 25 ± 4 breaths/min, P<0.05), MBP (90 ± 14 vs 94 ± 18 mmHg, P<0.05), HR (90 ± 17 vs 96 ± 12 beats/min, P<0.05), P ET CO 2 (33 ± 8 vs 48 ± 10 mmHg, P<0.05) and reduced SpO 2 (98 ± 1.6 vs 96 ± 1.6%, P<0.05). In addition, LF increased (47 ± 18 vs 38 ± 12 nu, P<0.05) and HF reduced (29 ± 13 vs 32 ± 16 nu, P<0.05), resulting in higher LF/HF ratio (1.62 ± 2 vs 1.18 ± 1, P<0.05) during TT. Conversely, V T increased with PSV (0.58 ± 0.16 vs 0.50 ± 0.15 L, P<0.05) compared with TT. Acute effects of TT mode may be closely linked to cardiorespiratory mismatches and cardiac autonomic imbalance in critically ill patients. © 2015 John Wiley & Sons Ltd.

  12. Intermittent hypoxia-induced respiratory long-term facilitation is dominated by enhanced burst frequency, not amplitude, in spontaneously breathing urethane-anesthetized neonatal rats.

    Science.gov (United States)

    Reid, Inefta M; Solomon, Irene C

    2014-01-01

    Acute intermittent hypoxia (AIH) triggers a form of respiratory plasticity known as long-term facilitation (LTF), which is manifested as a progressive increase in respiratory motor activity that lasts for minutes to hours after the hypoxic stimulus is removed. Respiratory LTF has been reported in numerous animal models, but it appears to be influenced by a variety of factors (e.g., species, age, and gender). While most studies focusing on respiratory LTF have been conducted in adult (including young adult) rat preparations, little is known about the influence of postnatal maturation on AIH-induced respiratory LTF. To begin to address this issue, we examined diaphragm EMG activity in response to and at 5-min intervals for 60 min following three 5-min episodes of hypoxia (8% O2) in urethane-anesthetized spontaneously breathing P14-P15 neonatal rats (n=15). For these experiments, the hypoxic episodes were separated by hyperoxia (40% O2), and all rats were continuously supplied with ~4% CO2. During the AIH trials, burst frequency was increased by ~20-90% above baseline in each of the rats examined while changes in burst amplitude were highly variable. Following the AIH episodes, respiratory LTF was characterized by predominantly an increase in burst frequency (fLTF) ranging from ~10% to 55%, with most rats exhibiting a 20-40% increase. In seven rats, however, an increase in amplitude (ampLTF) (~10%, n=3; ~20%, n=3; ~30%, n=1) was also noted. These data suggest that in contrast to observations in anesthetized ventilated adult rats, in anesthetized spontaneously breathing P14-P15 neonatal rats, respiratory LTF is dominated by fLTF, not ampLTF. © 2014 Elsevier B.V. All rights reserved.

  13. The cerebral cost of breathing: an FMRI case-study in congenital central hypoventilation syndrome.

    Directory of Open Access Journals (Sweden)

    Mike Sharman

    Full Text Available Certain motor activities--like walking or breathing--present the interesting property of proceeding either automatically or under voluntary control. In the case of breathing, brainstem structures located in the medulla are in charge of the automatic mode, whereas cortico-subcortical brain networks--including various frontal lobe areas--subtend the voluntary mode. We speculated that the involvement of cortical activity during voluntary breathing could impact both on the "resting state" pattern of cortical-subcortical connectivity, and on the recruitment of executive functions mediated by the frontal lobe. In order to test this prediction we explored a patient suffering from central congenital hypoventilation syndrome (CCHS, a very rare developmental condition secondary to brainstem dysfunction. Typically, CCHS patients demonstrate efficient cortically-controlled breathing while awake, but require mechanically-assisted ventilation during sleep to overcome the inability of brainstem structures to mediate automatic breathing. We used simultaneous EEG-fMRI recordings to compare patterns of brain activity between these two types of ventilation during wakefulness. As compared with spontaneous breathing (SB, mechanical ventilation (MV restored the default mode network (DMN associated with self-consciousness, mind-wandering, creativity and introspection in healthy subjects. SB on the other hand resulted in a specific increase of functional connectivity between brainstem and frontal lobe. Behaviorally, the patient was more efficient in cognitive tasks requiring executive control during MV than during SB, in agreement with her subjective reports in everyday life. Taken together our results provide insight into the cognitive and neural costs of spontaneous breathing in one CCHS patient, and suggest that MV during waking periods may free up frontal lobe resources, and make them available for cognitive recruitment. More generally, this study reveals how the

  14. Strain-dependent effects of diazepam and the 5-HT2B/2C receptor antagonist SB 206553 in spontaneously hypertensive and Lewis rats tested in the elevated plus-maze

    Directory of Open Access Journals (Sweden)

    Takahashi R.N.

    2001-01-01

    Full Text Available The 5-HT2B/2C receptor antagonist SB 206553 exerts anxiolytic effects in rat models of anxiety. However, these effects have been reported for standard rat strains, thus raising the issue of SB 206553 effects in rat strains displaying different levels of anxiety. Herein, the effects of SB 206553 in a 5-min elevated plus-maze test of anxiety were compared to those of the reference anxiolytic, diazepam, in two rat strains respectively displaying high (Lewis rats and low (spontaneously hypertensive rats, SHR anxiety. Diazepam (0.37, 0.75, or 1.5 mg/kg; 30 min before testing increased in a dose-dependent manner the behavioral measures in SHR, but not in Lewis rats. On the other hand, SB 206553 (1.25, 2.5, or 5 mg/kg; 30 min before testing failed to alter the anxiety parameters in both strains, whereas it increased closed arm entries in Lewis rats, suggesting that it elicited hyperactivity in the latter strain. Accordingly, the hypolocomotor effect of the nonselective 5-HT2B/2C receptor agonist m-chlorophenylpiperazine (1.5 mg/kg ip 20 min before a 15-min exposure to an activity cage was prevented by the 1.25 and 2.5 mg/kg doses of SB 206553 in Lewis rats and SHR, respectively. Compared with SHR, Lewis rats may display a lower response to benzodiazepine-mediated effects and a more efficient control of locomotor activity by 5-HT2B/2C receptors.

  15. The Cerebral Cost of Breathing: An fMRI Case-Study in Congenital Central Hypoventilation Syndrome

    Science.gov (United States)

    Sharman, Mike; Gallea, Cécile; Lehongre, Katia; Galanaud, Damien; Nicolas, Nathalie; Similowski, Thomas; Cohen, Laurent; Straus, Christian; Naccache, Lionel

    2014-01-01

    Certain motor activities - like walking or breathing - present the interesting property of proceeding either automatically or under voluntary control. In the case of breathing, brainstem structures located in the medulla are in charge of the automatic mode, whereas cortico-subcortical brain networks - including various frontal lobe areas - subtend the voluntary mode. We speculated that the involvement of cortical activity during voluntary breathing could impact both on the “resting state” pattern of cortical-subcortical connectivity, and on the recruitment of executive functions mediated by the frontal lobe. In order to test this prediction we explored a patient suffering from central congenital hypoventilation syndrome (CCHS), a very rare developmental condition secondary to brainstem dysfunction. Typically, CCHS patients demonstrate efficient cortically-controlled breathing while awake, but require mechanically-assisted ventilation during sleep to overcome the inability of brainstem structures to mediate automatic breathing. We used simultaneous EEG-fMRI recordings to compare patterns of brain activity between these two types of ventilation during wakefulness. As compared with spontaneous breathing (SB), mechanical ventilation (MV) restored the default mode network (DMN) associated with self-consciousness, mind-wandering, creativity and introspection in healthy subjects. SB on the other hand resulted in a specific increase of functional connectivity between brainstem and frontal lobe. Behaviorally, the patient was more efficient in cognitive tasks requiring executive control during MV than during SB, in agreement with her subjective reports in everyday life. Taken together our results provide insight into the cognitive and neural costs of spontaneous breathing in one CCHS patient, and suggest that MV during waking periods may free up frontal lobe resources, and make them available for cognitive recruitment. More generally, this study reveals how the active

  16. Hemorrhagic shock-induced endothelial cell activation in a spontaneous breathing and a mechanical ventilation hemorrhagic shock model is induced by a proinflammatory response and not by hypoxia.

    Science.gov (United States)

    van Meurs, Matijs; Wulfert, Francis M; Jongman, Rianne M; Schipper, Martin; Houwertjes, Martin C; Vaneker, Michiel; Scheffer, Gert Jan; Teppema, Luc J; Aarts, Leon P H J; Heeringa, Peter; Zijlstra, Jan G; Molema, Grietje

    2011-09-01

    The interaction between neutrophils and activated endothelium is essential for the development of multiple organ dysfunction in patients with hemorrhagic shock (HS). Mechanical ventilation frequently is used in patients with HS. The authors sought to investigate the consequences of mechanical ventilation of mice subjected to HS on microvascular endothelial activation in the lung and kidney. Anesthetized wild type C57BL/6 male mice were subjected to controlled hemorrhage; subgroups of mice were mechanically ventilated during the HS insult. To study the effect of acute hypoxia on the mice, the animals were housed in hypoxic cages. Gene expression levels was assessed by quantitative real-time polymerase chain reaction. Protein expression was assessed by immunohistochemistry and enzyme-linked immunosorbent assay. Ninety minutes after the shock induction, a vascular bed-specific, heterogeneous proinflammatory endothelial activation represented by E-selectin, vascular cell adhesion molecule 1, and intercellular adhesion molecule 1 expression was seen in kidney and lung. No differences in adhesion molecules between the spontaneously breathing and mechanically ventilated mice were found. Concentrations of the proinflammatory cytokines chemokine (C-X-C motif) ligand 1 (11.0-fold) and interleukin-6 (21.7-fold) were increased after 90 min of HS. Two hours of 6% oxygen did not induce the expression of E-selectin, vascular cell adhesion molecule 1, and intercellular adhesion molecule 1 in the kidneys and the lung. Hemorrhagic shock leads to an early and reversible proinflammatory endothelial activation in kidney and lung. HS-induced endothelial activation is not changed by mechanical ventilation during the shock phase. Hypoxia alone does not lead to endothelial activation. The observed proinflammatory endothelial activation is mostly ischemia- or reperfusion-dependent and not related to hypoxia.

  17. Effects of reduced rebreathing time, in spontaneously breathing patients, on respiratory effort and accuracy in cardiac output measurement when using a partial carbon dioxide rebreathing technique: a prospective observational study.

    Science.gov (United States)

    Tachibana, Kazuya; Imanaka, Hideaki; Takeuchi, Muneyuki; Nishida, Tomoyo; Takauchi, Yuji; Nishimura, Masaji

    2005-10-05

    New technology using partial carbon dioxide rebreathing has been developed to measure cardiac output. Because rebreathing increases respiratory effort, we investigated whether a newly developed system with 35 s rebreathing causes a lesser increase in respiratory effort under partial ventilatory support than does the conventional system with 50 s rebreathing. We also investigated whether the shorter rebreathing period affects the accuracy of cardiac output measurement. Once a total of 13 consecutive post-cardiac-surgery patients had recovered spontaneous breathing under pressure support ventilation, we applied a partial carbon dioxide rebreathing technique with rebreathing of 35 s and 50 s in a random order. We measured minute ventilation, and arterial and mixed venous carbon dioxide tension at the end of the normal breathing period and at the end of the rebreathing periods. We then measured cardiac output using the partial carbon dioxide rebreathing technique with the two rebreathing periods and using thermodilution. With both rebreathing systems, minute ventilation increased during rebreathing, as did arterial and mixed venous carbon dioxide tensions. The increases in minute ventilation and arterial carbon dioxide tension were less with 35 s rebreathing than with 50 s rebreathing. The cardiac output measures with both systems correlated acceptably with values obtained with thermodilution. When patients breathe spontaneously the partial carbon dioxide rebreathing technique increases minute ventilation and arterial carbon dioxide tension, but the effect is less with a shorter rebreathing period. The 35 s rebreathing period yielded cardiac output measurements similar in accuracy to those with 50 s rebreathing.

  18. Effect of body position on the arterial partial pressures of oxygen and carbon dioxide in spontaneously breathing, conscious dogs in an intensive care unit.

    Science.gov (United States)

    McMillan, Matthew W; Whitaker, Katie E; Hughes, Dez; Brodbelt, David C; Boag, Amanda K

    2009-12-01

    To evaluate the effect of body position on the arterial partial pressures of oxygen and carbon dioxide (PaO(2), PaCO(2)), and the efficiency of pulmonary oxygen uptake as estimated by alveolar-arterial oxygen difference (A-a difference). Prospective, randomized, crossover study. University teaching hospital, intensive care unit. Twenty-one spontaneously breathing, conscious, canine patients with arterial catheters placed as part of their management strategy. Patients were placed randomly into lateral or sternal recumbency. PaO(2) and PaCO(2) were measured after 15 minutes in this position. Patients were then repositioned into the opposite position and after 15 minutes the parameters were remeasured. Results presented as median (interquartile range). PaO(2) was significantly higher (P=0.001) when patients were positioned in sternal, 91.2 mm Hg (86.0-96.1 mm Hg), compared with lateral recumbency, 86.4 mm Hg (73.9-90.9 mm Hg). The median change was 5.4 mm Hg (1.1-17.9 mm Hg). All 7 dogs with a PaO(2)<80 mm Hg in lateral recumbency had improved arterial oxygenation in sternal recumbency, median increase 17.4 mm Hg with a range of 3.8-29.7 mm Hg. PaCO(2) levels when patients were in sternal recumbency, 30.5 mm Hg (27.3-32.7 mm Hg) were not significantly different from those in lateral recumbency, 32.2 mm Hg (28.3-36.0 mm Hg) (P=0.07). The median change was -1.9 mm Hg (-3.6-0.77 mm Hg). A-a differences were significantly lower (P=0.005) when patients were positioned in sternal recumbency, 21.7 mm Hg (17.3-27.7 mm Hg), compared with lateral recumbency, 24.6 mm Hg (20.4-36.3 mm Hg). The median change was -3.1 mm Hg (-14.6-0.9 mm Hg). PaO(2) was significantly higher when animals were positioned in sternal recumbency compared with lateral recumbency, predominantly due to improved pulmonary oxygen uptake (decreased A-a difference) rather than increased alveolar ventilation (decreased PaCO(2)). Patients with hypoxemia (defined as PaO(2)<80 mm Hg) in lateral recumbency may

  19. Mapleson's Breathing Systems

    OpenAIRE

    Kaul, Tej K; Mittal, Geeta

    2013-01-01

    Mapleson breathing systems are used for delivering oxygen and anaesthetic agents and to eliminate carbon dioxide during anaesthesia. They consist of different components: Fresh gas flow, reservoir bag, breathing tubes, expiratory valve, and patient connection. There are five basic types of Mapleson system: A, B, C, D and E depending upon the different arrangements of these components. Mapleson F was added later. For adults, Mapleson A is the circuit of choice for spontaneous respiration where...

  20. Efficacy and tolerability of yoga breathing in patients with chronic obstructive pulmonary disease: a pilot study.

    Science.gov (United States)

    Pomidori, Luca; Campigotto, Federica; Amatya, Tara Man; Bernardi, Luciano; Cogo, Annalisa

    2009-01-01

    Yoga-derived breathing has been reported to improve gas exchange in patients with chronic heart failure and in participants exposed to high-altitude hypoxia. We investigated the tolerability and effect of yoga breathing on ventilatory pattern and oxygenation in patients with chronic obstructive pulmonary disease (COPD). Patients with COPD (N = 11, 3 women) without previous yoga practice and taking only short-acting beta2-adrenergic blocking drugs were enrolled. Ventilatory pattern and oxygen saturation were monitored by means of inductive plethysmography during 30-minute spontaneous breathing at rest (sb) and during a 30-minute yoga lesson (y). During the yoga lesson, the patients were requested to mobilize in sequence the diaphragm, lower chest, and upper chest adopting a slower and deeper breathing. We evaluated oxygen saturation (SaO2%), tidal volume (VT), minute ventilation (E), respiratory rate (i>f), inspiratory time, total breath time, fractional inspiratory time, an index of thoracoabdominal coordination, and an index of rapid shallow breathing. Changes in dyspnea during the yoga lesson were assessed with the Borg scale. During the yoga lesson, data showed the adoption of a deeper and slower breathing pattern (VTsb L 0.54[0.04], VTy L 0.74[0.08], P = .01; i>fsb 20.8[1.3], i>fy 13.8[0.2], P = .001) and a significant improvement in SaO2% with no change in E (SaO2%sb 91.5%[1.13], SaO2%y 93.5%[0.99], P = .02; Esb L/min 11.2[1.1], Ey L/min 10.2[0.9]). All the participants reported to be comfortable during the yoga lesson, with no increase in dyspnea index. We conclude that short-term training in yoga is well tolerated and induces favorable respiratory changes in patients with COPD.

  1. Breathing difficulty

    Science.gov (United States)

    Shortness of breath; Breathlessness; Difficulty breathing; Dyspnea ... There is no standard definition for difficulty breathing. Some people ... even though they don't have a medical condition. Others may ...

  2. Spontaneous pneumothorax in weightlifters.

    Science.gov (United States)

    Marnejon, T; Sarac, S; Cropp, A J

    1995-06-01

    Spontaneous pneumothorax is infrequently caused by strenuous exertion. To our knowledge there has only been one case of spontaneous pneumothorax associated with weightlifting reported in the medical literature. We describe three consecutive cases of spontaneous pneumothorax associated with weightlifting. We postulate that spontaneous pneumothorax in these patients may be secondary to improper breathing techniques. It is important that physicians and weight trainers be aware of the association between weight lifting and spontaneous pneumothorax and assure that proper instruction is given to athletes who work with weights.

  3. Weaning by gradual pressure support (PS reduction without an initial spontaneous breathing trial (SBT versus PS-supported SBT: A pilot study

    Directory of Open Access Journals (Sweden)

    K. Gnanapandithan

    2011-11-01

    Full Text Available Background and aim: Studies on weaning strategies have yielded conflicting results regarding the superiority of different methods. The aim of this RCT was to compare the efficacy of gradual pressure support (PS reduction without an initial spontaneous breathing trial (SBT with PS-supported SBT. Methods: Patients mechanically ventilated for >24 h were randomized to weaning by gradual reduction of PS without an initial SBT versus once daily SBT (PS 7 cm H2O. The primary outcomes were the rates of successful weaning trial and time to successful extubation. The secondary outcomes were the ICU and hospital length of stay, hospital mortality and the occurrence of ventilator-associated pneumonia (VAP. Results: Of the 120 patients (61 males, median age 35 years, 58 were assigned to PS and 62 to the SBT group. The median (IQR duration of ventilation prior to weaning was 80.2 (50.5–175.6 h. The baseline characteristics were similar in the two groups except the PaO2/FiO2 ratio, which was significantly higher in SBT group. The rates of successful weaning trial (89.7% versus 69.4% were significantly higher in the PS group. The median duration of weaning (66 h versus 81.5 h, P = 0.05 and the median duration of ICU stay (8 days versus 9.4 days, P = 0.027 were lower in the PS group. There was no difference in hospital stay, mortality rates or occurrence of VAP in the two arms. On multivariate analysis, the duration of ventilation prior to weaning, baseline SOFA score and the weaning method were predictors of successful extubation. Conclusions: Gradual reduction of PS without an initial SBT was found to be associated with better outcomes compared to once daily PS-supported SBT. Resumo: Antecedentes e objetivo: Os estudos sobre estratégias de desmame tiveram resultados controversos em relação à superioridade de métodos diferentes. O objetivo deste RCT foi comparar a eficácia da redução gradual da press

  4. Breathing Problems

    Science.gov (United States)

    ... getting enough air. Sometimes you can have mild breathing problems because of a stuffy nose or intense ... panic attacks Allergies If you often have trouble breathing, it is important to find out the cause.

  5. Mapleson's Breathing Systems.

    Science.gov (United States)

    Kaul, Tej K; Mittal, Geeta

    2013-09-01

    Mapleson breathing systems are used for delivering oxygen and anaesthetic agents and to eliminate carbon dioxide during anaesthesia. They consist of different components: Fresh gas flow, reservoir bag, breathing tubes, expiratory valve, and patient connection. There are five basic types of Mapleson system: A, B, C, D and E depending upon the different arrangements of these components. Mapleson F was added later. For adults, Mapleson A is the circuit of choice for spontaneous respiration where as Mapleson D and its Bains modifications are best available circuits for controlled ventilation. For neonates and paediatric patients Mapleson E and F (Jackson Rees modification) are the best circuits. In this review article, we will discuss the structure of the circuits and functional analysis of various types of Mapleson systems and their advantages and disadvantages.

  6. Breathing Difficulties

    Science.gov (United States)

    ... symptoms. Symptoms associated with weak respiratory muscles: Air “hunger” (gasping, labored breathing) with an without activity Fatigue ... Start your own fundraising event & help create a world without ALS Start an Event Site Map | Press ...

  7. Breath sounds

    Science.gov (United States)

    ... described as moist, dry, fine, and coarse. Rhonchi. Sounds that resemble snoring. They occur when air is blocked or air flow becomes rough through the large airways. Stridor. Wheeze-like sound heard when a person breathes. Usually it is ...

  8. Bad Breath

    Science.gov (United States)

    ... fresh and healthy. Tips for preventing bad breath: Brush your teeth (and tongue!) for at least two minutes twice ... and drinks. This helps prevent damage to your teeth and is great for your overall health. Brush after sweets. If you eat or drink sugary ...

  9. Cd-Sb-Al system

    International Nuclear Information System (INIS)

    Belotskij, D.P.; Dundich, M.S.; Kotsyumakha, M.P.; Makhova, M.K.; Lesina, N.V.; Noval'kovskij, N.P.

    1985-01-01

    The methods of differential-thermal, microstructural analyses and measuring microhardness are used to investigate the phase diagrams of polythermal sections CdSb-AlSb, CdSb-Al, Cd-AlSb, Cdsub(0.5)Alsub(0.5)-Sb, CdSb-Alsub(0.2)Cdsub(0.8) of the ternary system Cd-Sb-Al. The liquidus projection of the Cd-Sb-Al system is plotted; it has been found that the surface of aluminium antimonide formation occupies a large part of the phase diagram in the field of which the lamination region is located

  10. Optical Characterization of AlAsSb Digital Alloy and Random Alloy on GaSb

    Directory of Open Access Journals (Sweden)

    Bor-Chau Juang

    2017-10-01

    Full Text Available III-(As, Sb alloys are building blocks for various advanced optoelectronic devices, but the growth of their ternary or quaternary materials are commonly limited by spontaneous formation of clusters and phase separations during alloying. Recently, digital alloy growth by molecular beam epitaxy has been widely adopted in preference to conventional random alloy growth because of the extra degree of control offered by the ordered alloying. In this article, we provide a comparative study of the optical characteristics of AlAsSb alloys grown lattice-matched to GaSb using both techniques. The sample grown by digital alloy technique showed stronger photoluminescence intensity, narrower peak linewidth, and larger carrier activation energy than the random alloy technique, indicating an improved optical quality with lower density of non-radiative recombination centers. In addition, a relatively long carrier lifetime was observed from the digital alloy sample, consistent with the results obtained from the photoluminescence study.

  11. Variability of exhaled breath condensate (EBC) volume and pH using a feedback regulated breathing pattern

    Science.gov (United States)

    Exhaled breath condensate (EBC) is a valuable biological medium for non-invasively measuring biomarkers with the potential to reflect organ systems responses to environmental and dietary exposures and disease processes. Collection of EBC has typically been with spontaneous breat...

  12. The Influence of Age on Interaction between Breath-Holding Test and Single-Breath Carbon Dioxide Test

    Directory of Open Access Journals (Sweden)

    Nikita Trembach

    2017-01-01

    Full Text Available Introduction. The aim of the study was to compare the breath-holding test and single-breath carbon dioxide test in evaluation of the peripheral chemoreflex sensitivity to carbon dioxide in healthy subjects of different age. Methods. The study involved 47 healthy volunteers between ages of 25 and 85 years. All participants were divided into 4 groups according to age: 25 to 44 years (n=14, 45 to 60 years (n=13, 60 to 75 years (n=12, and older than 75 years (n=8. Breath-holding test was performed in the morning before breakfast. The single-breath carbon dioxide (SB-CO2 test was performed the following day. Results. No correlation was found between age and duration of breath-holding (r=0.13 and between age and peripheral chemoreflex sensitivity to CO2 (r=0.07. In all age groups there were no significant differences in the mean values from the breath-holding test and peripheral chemoreflex sensitivity tests. In all groups there was a strong significant inverse correlation between breath-holding test and SB-CO2 test. Conclusion. A breath-holding test reflects the sensitivity of the peripheral chemoreflex to carbon dioxide in healthy elderly humans. Increasing age alone does not alter the peripheral ventilatory response to hypercapnia.

  13. The Influence of Age on Interaction between Breath-Holding Test and Single-Breath Carbon Dioxide Test.

    Science.gov (United States)

    Trembach, Nikita; Zabolotskikh, Igor

    2017-01-01

    Introduction . The aim of the study was to compare the breath-holding test and single-breath carbon dioxide test in evaluation of the peripheral chemoreflex sensitivity to carbon dioxide in healthy subjects of different age. Methods . The study involved 47 healthy volunteers between ages of 25 and 85 years. All participants were divided into 4 groups according to age: 25 to 44 years ( n = 14), 45 to 60 years ( n = 13), 60 to 75 years ( n = 12), and older than 75 years ( n = 8). Breath-holding test was performed in the morning before breakfast. The single-breath carbon dioxide (SB-CO 2 ) test was performed the following day. Results . No correlation was found between age and duration of breath-holding ( r = 0.13) and between age and peripheral chemoreflex sensitivity to CO 2 ( r = 0.07). In all age groups there were no significant differences in the mean values from the breath-holding test and peripheral chemoreflex sensitivity tests. In all groups there was a strong significant inverse correlation between breath-holding test and SB-CO 2 test. Conclusion . A breath-holding test reflects the sensitivity of the peripheral chemoreflex to carbon dioxide in healthy elderly humans. Increasing age alone does not alter the peripheral ventilatory response to hypercapnia.

  14. Breath holding spell

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000967.htm Breath holding spell To use the sharing features on this page, please enable JavaScript. Some children have breath holding spells. This is an involuntary stop in breathing ...

  15. Deep breathing after surgery

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000440.htm Deep breathing after surgery To use the sharing features on ... way to do so is by doing deep breathing exercises. Deep breathing keeps your lungs well-inflated ...

  16. Breathing difficulty - lying down

    Science.gov (United States)

    ... short of breath; Paroxysmal nocturnal dyspnea; PND; Difficulty breathing while lying down; Orthopnea; Heart failure - orthopnea ... Heart failure Obesity (does not directly cause difficulty breathing while lying down but often worsens other conditions ...

  17. Apolo Ohno: Breathing Easier

    Science.gov (United States)

    ... of this page please turn Javascript on. Feature: Breathing Easier Apolo Ohno: Breathing Easier Past Issues / Fall 2013 Table of Contents ... training, I started experiencing decreased exercise endurance, trouble breathing, and coughing. These symptoms affected my ability to ...

  18. Rapid shallow breathing

    Science.gov (United States)

    Tachypnea; Breathing - rapid and shallow; Fast shallow breathing; Respiratory rate - rapid and shallow ... Shallow, rapid breathing has many possible medical causes, including: Asthma Blood clot in an artery in the lung Choking Chronic obstructive ...

  19. Breathing and Relaxation

    Science.gov (United States)

    ... Home Health Insights Stress & Relaxation Breathing and Relaxation Breathing and Relaxation Make an Appointment Ask a Question ... level is often dependent on his or her breathing pattern. Therefore, people with chronic lung conditions may ...

  20. Breathing difficulties - first aid

    Science.gov (United States)

    Difficulty breathing - first aid; Dyspnea - first aid; Shortness of breath - first aid ... Breathing difficulty is almost always a medical emergency. An exception is feeling slightly winded from normal activity, ...

  1. Traveling with breathing problems

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000066.htm Traveling with breathing problems To use the sharing features on this page, please enable JavaScript. If you have breathing problems and you: Are short of breath most ...

  2. Breathing - slowed or stopped

    Science.gov (United States)

    ... bradypnea. Labored or difficult breathing is known as dyspnea. ... Premature birth Seizures Common causes of breathing trouble (dyspnea) in adults include: Allergic reaction that causes tongue, ...

  3. Effects of different levels of positive airway pressure on breathing pattern and heart rate variability after coronary artery bypass grafting surgery

    Directory of Open Access Journals (Sweden)

    C.B.F. Pantoni

    2011-01-01

    Full Text Available The application of continuous positive airway pressure (CPAP produces important hemodynamic alterations, which can influence breathing pattern (BP and heart rate variability (HRV. The aim of this study was to evaluate the effects of different levels of CPAP on postoperative BP and HRV after coronary artery bypass grafting (CABG surgery and the impact of CABG surgery on these variables. Eighteen patients undergoing CABG were evaluated postoperatively during spontaneous breathing (SB and application of four levels of CPAP applied in random order: sham (3 cmH2O, 5 cmH2O, 8 cmH2O, and 12 cmH2O. HRV was analyzed in time and frequency domains and by nonlinear methods and BP was analyzed in different variables (breathing frequency, inspiratory tidal volume, inspiratory and expiratory time, total breath time, fractional inspiratory time, percent rib cage inspiratory contribution to tidal volume, phase relation during inspiration, phase relation during expiration. There was significant postoperative impairment in HRV and BP after CABG surgery compared to the preoperative period and improvement of DFAα1, DFAα2 and SD2 indexes, and ventilatory variables during postoperative CPAP application, with a greater effect when 8 and 12 cmH2O were applied. A positive correlation (P < 0.05 and r = 0.64; Spearman was found between DFAα1 and inspiratory time to the delta of 12 cmH2O and SB of HRV and respiratory values. Acute application of CPAP was able to alter cardiac autonomic nervous system control and BP of patients undergoing CABG surgery and 8 and 12 cmH2O of CPAP provided the best performance of pulmonary and cardiac autonomic functions.

  4. Fast-starting for a breath: Air breathing in Hoplosternum littorale

    DEFF Research Database (Denmark)

    Domenici, Paolo; Norin, Tommy; Bushnell, Peter G.

    by the fall of a prey item on the water surface, and in tapping motions of goldfish, a behaviour that was interpreted to be food-related. Little is known about C-starts being used outside the context of escaping or feeding. Here, we test the hypothesis that air-breathing fish may use C-starts when gulping air...... at the surface. Air breathing is a common behaviour in many fish species when exposed to hypoxia, although certain species perform air-breathing in normoxia to fill their swim bladders for buoyancy control and/or sound transduction. Hoplosternum littorale is an air-breathing freshwater catfish found in South...... America. Field video observations reveal that their air-breathing behaviour consists of a fast air-gulping motion at the surface, followed by swimming towards the bottom. Using high-speed video in the laboratory, we compared the kinematics of spontaneous air-gulping performed by H. littorale in normoxia...

  5. Mapleson′s breathing systems

    Directory of Open Access Journals (Sweden)

    Tej K Kaul

    2013-01-01

    Full Text Available Mapleson breathing systems are used for delivering oxygen and anaesthetic agents and to eliminate carbon dioxide during anaesthesia. They consist of different components: Fresh gas flow, reservoir bag, breathing tubes, expiratory valve, and patient connection. There are five basic types of Mapleson system: A, B, C, D and E depending upon the different arrangements of these components. Mapleson F was added later. For adults, Mapleson A is the circuit of choice for spontaneous respiration where as Mapleson D and its Bains modifications are best available circuits for controlled ventilation. For neonates and paediatric patients Mapleson E and F (Jackson Rees modification are the best circuits. In this review article, we will discuss the structure of the circuits and functional analysis of various types of Mapleson systems and their advantages and disadvantages.

  6. Slow Breathing and Hypoxic Challenge: Cardiorespiratory Consequences and Their Central Neural Substrates

    OpenAIRE

    Critchley, Hugo D.; Nicotra, Alessia; Chiesa, Patrizia A.; Nagai, Yoko; Gray, Marcus A.; Minati, Ludovico; Bernardi, Luciano

    2015-01-01

    Controlled slow breathing (at 6/min, a rate frequently adopted during yoga practice) can benefit cardiovascular function, including responses to hypoxia. We tested the neural substrates of cardiorespiratory control in humans during volitional controlled breathing and hypoxic challenge using functional magnetic resonance imaging (fMRI). Twenty healthy volunteers were scanned during paced (slow and normal rate) breathing and during spontaneous breathing of normoxic and hypoxic (13% inspired O2)...

  7. Spontaneous pneumothorax

    Directory of Open Access Journals (Sweden)

    Davari R

    1996-07-01

    Full Text Available A case with bilateral spontaneous pneumothorax was presented. Etiology, mechanism, and treatment were discussed on the review of literature. Spontaneous Pneumothorax is a clinical entity resulting from a sudden non traumatic rupture of the lung. Biach reported in 1880 that 78% of 916 patients with spontaneous pneumothorax had tuberculosis. Kjergaard emphasized 1932 the primary importance of subpleural bleb disease. Currently the clinical spectrum of spontaneous pneumothorax seems to have entered a third era with the recognition of the interstitial lung disease and AIDS as a significant etiology. Standard treatment is including: observation, thoracocentesis, tube thoracostomy. Chemical pleurodesis, bullectomy or wedge resection of lung with pleural abrasion and occasionally pleurectomy. Little information has been reported regarding the efficacy of such treatment in spontaneous pneumothorax secondary to non bleb disease

  8. Structures of Ge15Sb x Se85- x chalcogenide glasses affect their Raman gain performance

    Science.gov (United States)

    Peng, Xuefeng; Dai, Shixun; Xu, Dong; Xu, Hang; Li, Xing; Lin, Changgui; Zhang, Peiqing; Xu, Tiefeng

    2017-10-01

    A series of Ge15Sb x Se85- x ( x = 5, 10, 15, 20, 25, and 30 mol%) chalcogenide glasses were prepared by traditional melt-quenching method. The refractive indexes, infrared transmissions, and spontaneous Raman spectra of the glass samples were measured. Based on the spontaneous Raman scattering theory and considering the measured Raman spectral data, we calculated the Raman gain coefficients of the chalcogenide glasses. The effect of Sb on the structures and Raman gain coefficients of the glass samples was then systematically investigated to understand the role of chemical composition in glass structure and Raman gain coefficient. In the Ge15Sb x Se85- x glasses, the number of heteropolar Ge-Se, Sb-Se bonds increased, whereas that of homopolar Se-Se bonds decreased at increased Sb concentration. The Raman gain coefficients increased until it reached a maximum value (290 × 10-13 m/W at Ge15Sb20Se65) and then decreased when the Sb concentration further increased. These results showed that the Raman gain coefficients of Ge-Sb-Se chalcogenide glasses without poisonous elements were over 300 times of that of commonly fused silica and closely correlated with the structures of the glasses, suggesting that the Raman gain coefficient can be adjusted by modifying the structures of the glasses. This work provides a new possibility for environment-friendly Raman fiber laser and amplifier materials.

  9. What Causes Bad Breath?

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español What Causes Bad Breath? KidsHealth / For Teens / What Causes Bad Breath? Print en español ¿Qué es lo ... through your mouth. Smoking is also a major cause of bad breath. There are lots of myths ...

  10. Breath-Holding Spells

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Breath-Holding Spells KidsHealth / For Parents / Breath-Holding Spells What's in ... Spells Print en español Espasmos de sollozo About Breath-Holding Spells Many of us have heard stories about stubborn ...

  11. Spontaneous deregulation

    NARCIS (Netherlands)

    Edelman, Benjamin; Geradin, Damien

    Platform businesses such as Airbnb and Uber have risen to success partly by sidestepping laws and regulations that encumber their traditional competitors. Such rule flouting is what the authors call “spontaneous private deregulation,” and it’s happening in a growing number of industries. The authors

  12. Exhaled Carbon Dioxide and Neonatal Breathing Patterns in Preterm Infants after Birth.

    Science.gov (United States)

    Nicoll, Jessica; Cheung, Po-Yin; Aziz, Khalid; Rajani, Vishaal; O'Reilly, Megan; Pichler, Gerhard; Schmölzer, Georg M

    2015-10-01

    To examine the amount of exhaled carbon dioxide (ECO2) with different breathing patterns in spontaneously breathing preterm infants after birth. Preterm infants had a facemask attached to a combined carbon dioxide/flow sensor placed over their mouth and nose to record ECO2 and gas flow. A breath-by-breath analysis of the first 5 minutes of the recording was performed. Thirty spontaneously breathing preterm infants, gestational age (mean ± SD) 30 ± 2 weeks and birth weight 1635 ± 499 g were studied. ECO2 from normal breaths and slow expirations was significantly larger than with other breathing patterns (P breath also increased with gestational age P breathing pattern both during the first minute of recording and overall. Breathing pattern proportions also varied by gestational age. Finally, ECO2 from the fifth minute of recording was significantly greater than that produced during the first 4 minutes of recording (P ≤ .029). ECO2 varies with different breathing patterns and increases with gestational age and over time. ECO2 may be an indicator of lung aeration and that postnatal ECO2 monitoring may be useful in preterm infants in the delivery room. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Imposed work of breathing during high-frequency oscillatory ventilation : a bench study

    NARCIS (Netherlands)

    van Heerde, Marc; van Genderingen, Huib R.; Leenhoven, Tom; Roubik, Karel; Ploetz, Frans B.; Markhorst, Dick G.

    2006-01-01

    Introduction The ventilator and the endotracheal tube impose additional workload in mechanically ventilated patients breathing spontaneously. The total work of breathing (WOB) includes elastic and resistive work. In a bench test we assessed the imposed WOB using 3100 A/3100 B SensorMedics

  14. How to breathe when you are short of breath

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000053.htm How to breathe when you are short of breath ... Watch TV Use your computer Read a newspaper How to do Pursed lip Breathing The steps to ...

  15. Breathing patterns and cardiovascular autonomic modulation during hypoxia induced by simulated altitude.

    Science.gov (United States)

    Bernardi, L; Passino, C; Wilmerding, V; Dallam, G M; Parker, D L; Robergs, R A; Appenzeller, O

    2001-05-01

    To assess the influence of different breathing patterns on autonomic cardiovascular modulation during acute exposure to altitude-induced hypoxia. We measured relative changes in minute ventilation (VE), oxygen saturation (%SaO2), spectral analysis of RR interval and blood pressure, and response to stimulation of carotid baroreceptors (neck suction) at baseline and after acute (1 h) hypobaric hypoxia (equivalent to 5,000 m, in a hypobaric chamber). We studied 19 human subjects: nine controls and 10 Western yoga trainees of similar age, while breathing spontaneously, at 15 breaths/min (controlled breathing) and during 'complete yogic breathing' (slow diaphragmatic + thoracic breathing, approximately 5 breaths/min) in yoga trainees, or simple slow breathing in controls. At baseline %SaO2, VE and autonomic pattern were similar in both groups; simulated altitude increased VE in controls but not in yoga trainees; %SaO2 decreased in all subjects (Pbreathing, controlled breathing and yogic or slow breathing, respectively). Simulated altitude decreased RR interval (from 879 +/- 45 to 770 +/- 39, P breathing. No effect of altitude was seen on stimulation of carotid baroreceptors in both groups. Well-performed slow yogic breathing maintains better blood oxygenation without increasing VE (i.e. seems to be a more efficient breathing) and reduces sympathetic activation during altitude-induced hypoxia.

  16. Molar and excess volumes of liquid In-Sb, Mg-Sb, and Pb-Sb alloys

    International Nuclear Information System (INIS)

    Hansen, A.R.; Kaminski, M.A.; Eckert, C.A.

    1990-01-01

    By a direct Archimedes' technique, volumetric data were obtained for liquid In, Mg, Pb, and Sb and mixtures of In-Sb, Mg-Sb, and Pb-Sb. In this paper the excess volumes for the alloys studied are presented and discussed

  17. Eldercare at Home: Breathing Problems

    Science.gov (United States)

    ... Join our e-newsletter! Resources Eldercare at Home: Breathing Problems Caregiving How Tos Understanding the Problem As ... However, aging sometimes brings on other more serious breathing problems including incapacitating shortness of breath, chest discomfort, ...

  18. From breathing to respiration.

    Science.gov (United States)

    Fitting, Jean-William

    2015-01-01

    The purpose of breathing remained an enigma for a long time. The Hippocratic school described breathing patterns but did not associate breathing with the lungs. Empedocles and Plato postulated that breathing was linked to the passage of air through pores of the skin. This was refuted by Aristotle who believed that the role of breathing was to cool the heart. In Alexandria, breakthroughs were accomplished in the anatomy and physiology of the respiratory system. Later, Galen proposed an accurate description of the respiratory muscles and the mechanics of breathing. However, his heart-lung model was hampered by the traditional view of two non-communicating vascular systems - veins and arteries. After a period of stagnation in the Middle Ages, knowledge progressed with the discovery of pulmonary circulation. The comprehension of the purpose of breathing progressed by steps thanks to Boyle and Mayow among others, and culminated with the contribution of Priestley and the discovery of oxygen by Lavoisier. Only then was breathing recognized as fulfilling the purpose of respiration, or gas exchange. A century later, a controversy emerged concerning the active or passive transfer of oxygen from alveoli to the blood. August and Marie Krogh settled the dispute, showing that passive diffusion was sufficient to meet the oxygen needs. © 2014 S. Karger AG, Basel.

  19. Breath alcohol test (image)

    Science.gov (United States)

    The breath alcohol test measures the amount of alcohol in the blood by testing exhaled air. The test is performed by blowing ... breath machine 15 minutes after alcohol consumption. The test determines how much alcohol it takes to raise the blood-alcohol level ...

  20. Minimizing Shortness of Breath

    Science.gov (United States)

    ... is also placed on proper use of the abdominal muscles to better control episodes of shortness of breath, limit overuse of the accessory muscles and manage respiratory symptoms. Monitor Breathing During an activity, it is important to pause frequently to check ...

  1. Sleep bruxism and sleep-disordered breathing: a systematic review.

    Science.gov (United States)

    De Luca Canto, Graziela; Singh, Vandana; Gozal, David; Major, Paul W; Flores-Mir, Carlos

    2014-01-01

    To carry out a systematic review to consolidate current knowledge on the potential association between sleep bruxism (SB) and sleep-disordered breathing (SDB). For this systematic review, articles were retained only if they reported studies using full ambulatory polysomnography as "the gold standard" reference test to determine SDB and the international diagnostic criteria proposed by the American Association of Sleep Medicine to determine SB. Detailed individual search strategies from MEDLINE, PubMed, Embase, the Cochrane Library, and LILACS databases were developed. The references cited in the selected articles were also checked, and a partial literature search was undertaken. The selection was completed independently by two reviewers in two phases. The methodology of selected studies was evaluated using the seven-item quality-assessment tool for experimental bruxism studies. During the initial search, 333 different citations were identified across the six electronic databases. After a comprehensive evaluation of the abstracts, and the full papers when considered necessary, only one study was finally selected for the qualitative/quantitative synthesis. This study did not support the putative association between SB and SDB, since SB was not observed during or in temporal conjunction with snoring or apneic events in any of the evaluated patients. In addition, masseter activity was not observed during apneic episodes. There is not sufficient scientific evidence either to confirm or discredit the association between SB and SDB.

  2. Liberation From Mechanical Ventilation in Critically Ill Adults: An Official American College of Chest Physicians/American Thoracic Society Clinical Practice Guideline: Inspiratory Pressure Augmentation During Spontaneous Breathing Trials, Protocols Minimizing Sedation, and Noninvasive Ventilation Immediately After Extubation.

    Science.gov (United States)

    Ouellette, Daniel R; Patel, Sheena; Girard, Timothy D; Morris, Peter E; Schmidt, Gregory A; Truwit, Jonathon D; Alhazzani, Waleed; Burns, Suzanne M; Epstein, Scott K; Esteban, Andres; Fan, Eddy; Ferrer, Miguel; Fraser, Gilles L; Gong, Michelle Ng; Hough, Catherine L; Mehta, Sangeeta; Nanchal, Rahul; Pawlik, Amy J; Schweickert, William D; Sessler, Curtis N; Strøm, Thomas; Kress, John P

    2017-01-01

    An update of evidence-based guidelines concerning liberation from mechanical ventilation is needed as new evidence has become available. The American College of Chest Physicians (CHEST) and the American Thoracic Society (ATS) have collaborated to provide recommendations to clinicians concerning liberation from the ventilator. Comprehensive evidence syntheses, including meta-analyses, were performed to summarize all available evidence relevant to the guideline panel's questions. The evidence was appraised using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach, and the results were summarized in evidence profiles. The evidence syntheses were discussed and recommendations developed and approved by a multidisciplinary committee of experts in mechanical ventilation. Recommendations for three population, intervention, comparator, outcome (PICO) questions concerning ventilator liberation are presented in this document. The guideline panel considered the balance of desirable (benefits) and undesirable (burdens, adverse effects, costs) consequences, quality of evidence, feasibility, and acceptability of various interventions with respect to the selected questions. Conditional (weak) recommendations were made to use inspiratory pressure augmentation in the initial spontaneous breathing trial (SBT) and to use protocols to minimize sedation for patients ventilated for more than 24 h. A strong recommendation was made to use preventive noninvasive ventilation (NIV) for high-risk patients ventilated for more than 24 h immediately after extubation to improve selected outcomes. The recommendations were limited by the quality of the available evidence. The guideline panel provided recommendations for inspiratory pressure augmentation during an initial SBT, protocols minimizing sedation, and preventative NIV, in relation to ventilator liberation. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights

  3. Growth and characterization of an InSb infrared photoconductor on Si via an AlSb/GaSb buffer

    Science.gov (United States)

    Jia, Bo Wen; Tan, Kian Hua; Loke, Wan Khai; Wicaksono, Satrio; Yoon, Soon Fatt

    2018-05-01

    A 99.6% relaxed InSb layer is grown on a 6° offcut (1 0 0) Si substrate via an AlSb/GaSb buffer using molecular beam epitaxy (MBE). A 200 nm GaSb buffer is first grown on Si and the lattice mismatch between them is accommodated by an interfacial misfit (IMF) array consisting of uniformly distributed 90° misfit dislocations. Si delta doping is introduced during the growth of GaSb to reduce the density of threading dislocation. Subsequently, a 50 nm AlSb buffer is grown followed by a 0.8 μm InSb layer. The InSb layer exhibits a 300 K electron mobility of 22,300 cm2/Vs. An InSb photoconductor on Si is demonstrated with a photoconductive gain from 77 K to 200 K under a 700 °C maintained blackbody.

  4. Molecular beam epitaxy of AlSb on GaAs and GaSb on AlSb films

    International Nuclear Information System (INIS)

    Gotoh, H.; Sasamoto, K.; Kuroda, S.; Kimata, M.

    1983-01-01

    Single crystalline AlSb films are successfully grown, by MBE on GaAs substrates at temperatures higher than 400 0 C. The surface gives a C(2 x 6) structure under Sb stabilized conditions. Undoped AlSb is p-type with resistivities of 10 2 to 10 3 Ωcm. Then, GaSb films are grown on AlSb/GaAs. It can be seen, from RHEED observation that the interface between AlSb and GaSb is very smooth, and the layer growth continues at the interface. Fabricating that structure improves the properties of GaSb in comparison with those of GaSb directly grown on GaAs by the relaxation of lattice mismatch. (author)

  5. Realization of single and double axial InSb-GaSb heterostructure nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Ghalamestani, Sepideh Gorji [Solid State Physics, Lund University, Lund (Sweden); Ek, Martin [Center for Analysis and Synthesis, Lund University, Lund (Sweden); Dick, Kimberly A. [Solid State Physics, Lund University, Lund (Sweden); Center for Analysis and Synthesis, Lund University, Lund (Sweden)

    2014-03-15

    Heteroepitaxial growth of III-Sb nanowires allows for the formation of various interesting complex structures and enables the combination of their remarkable properties. In this Letter, we investigate the heteroepitaxial growth of Au-seeded InSb and GaSb nanowires using metalorganic vapor phase epitaxy. We demonstrate successful single and double axial InSb-GaSb heterostructures in both directions. The formation properties of the grown nanowires including the compositional change of the particle and the interface sharpness are further discussed. In addition, the decomposition of InSb and GaSb segments and their side facet evolution are explained. XEDS compositional line scans overlaid on STEM HAADF image along the InSb-GaSb-InSb nanowire indicating sharp interface from GaSb to InSb segment and graded interface in the opposite direction. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Breath hydrogen analysis in patients with ileoanal pouch anastomosis

    DEFF Research Database (Denmark)

    Bruun, E; Meyer, J N; Rumessen, J J

    1995-01-01

    The possible influence on functional outcomes of hydrogen production in the ileoanal pouch after restorative proctocolectomy was investigated by means of lactulose H2 breath tests. Eight of 15 patients had significant increases in breath hydrogen after 10 g lactulose. One patient declined...... to participate in further investigations, the remaining seven responders had no evidence of small bowel bacterial overgrowth after glucose H2 breath tests. The ability to produce hydrogen by anaerobic fermentation of lactulose in the pouch was unrelated to the age of the patients or of the pouch. Seven of eight...... responders had successive breath tests after ingestion of lactulose 20 g and wheat starch 100 g. Five of seven had significant increases after lactulose but none after wheat starch. The overall function of the pouch continence, spontaneity of defecation, and 24 hour stool frequency was significantly better...

  7. Shortness of Breath

    Science.gov (United States)

    ... enough air. Shortness of breath — known medically as dyspnea — is often described as an intense tightening in ... properly. Schwartzstein RM. Approach to the patient with dyspnea. http://www.uptodate.com/home. Accessed Feb. 4, ...

  8. Slow breathing as a means to improve orthostatic tolerance: a randomized sham-controlled trial.

    Science.gov (United States)

    Lucas, Samuel J E; Lewis, Nia C S; Sikken, Elisabeth L G; Thomas, Kate N; Ainslie, Philip N

    2013-07-15

    Endogenous oscillations in blood pressure (BP) and cerebral blood flow have been associated with improved orthostatic tolerance. Although slow breathing induces such responses, it has not been tested as a therapeutic strategy to improve orthostatic tolerance. With the use of a randomized, crossover sham-controlled design, we tested the hypothesis that breathing at six breaths/min (vs. spontaneous breathing) would improve orthostatic tolerance via inducing oscillations in mean arterial BP (MAP) and cerebral blood flow. Sixteen healthy participants (aged 25 ± 4 yr; mean ± SD) had continuous beat-to-beat measurements of middle cerebral artery blood velocity (MCAv), BP (finometer), heart rate (ECG), and end-tidal carbon dioxide partial pressure during an incremental orthostatic stress test to presyncope by combining head-up tilt with incremental lower-body negative pressure. Tolerance time to presyncope was improved (+15%) with slow breathing compared with spontaneous breathing (29.2 ± 5.4 vs. 33.7 ± 6.0 min; P breathing) across time from baseline to presyncope. Our findings show that orthostatic tolerance can be improved within healthy individuals with a simple, nonpharmacological breathing strategy. The mechanisms underlying this improvement are likely mediated via the generation of negative intrathoracic pressure during slow and deep breathing and the related beneficial impact on cerebrovascular and autonomic function.

  9. DWPF SB6 INITIAL CPC FLOWSHEET TESTING SB6-1 TO SB6-4L TESTS OF SB6-A AND SB6-B SIMULANTS

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, D.; Pickenheim, B.; Best, D.

    2009-09-09

    The Defense Waste Processing Facility (DWPF) will transition from Sludge Batch 5 (SB5) processing to Sludge Batch 6 (SB6) processing in late fiscal year 2010. Tests were conducted using non-radioactive simulants of the expected SB6 composition to determine the impact of varying the acid stoichiometry during the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) processes. The work was conducted to meet the Technical Task Request (TTR) HLW/DWPF/TTR-2008-0043, Rev.0 and followed the guidelines of a Task Technical and Quality Assurance Plan (TT&QAP). The flowsheet studies are performed to evaluate the potential chemical processing issues, hydrogen generation rates, and process slurry rheological properties as a function of acid stoichiometry. These studies were conducted with the estimated SB6 composition at the time of the study. This composition assumed a blend of 101,085 kg of Tank 4 insoluble solids and 179,000 kg of Tank 12 insoluble solids. The current plans are to subject Tank 12 sludge to aluminum dissolution. Liquid Waste Operations assumed that 75% of the aluminum would be dissolved during this process. After dissolution and blending of Tank 4 sludge slurry, plans included washing the contents of Tank 51 to {approx}1M Na. After the completion of washing, the plan assumes that 40 inches on Tank 40 slurry would remain for blending with the qualified SB6 material. There are several parameters that are noteworthy concerning SB6 sludge: (1) This is the second batch DWPF will be processing that contains sludge that has had a significant fraction of aluminum removed through aluminum dissolution; (2) The sludge is high in mercury, but the projected concentration is lower than SB5; (3) The sludge is high in noble metals, but the projected concentrations are lower than SB5; and(4) The sludge is high in U and Pu - components that are not added in sludge simulants. Six DWPF process simulations were completed in 4-L laboratory-scale equipment using

  10. Molecular beam epitaxy of GaSb on GaAs substrates with AlSb/GaSb compound buffer layers

    International Nuclear Information System (INIS)

    Hao Ruiting; Deng Shukang; Shen Lanxian; Yang Peizhi; Tu Jielei; Liao Hua; Xu Yingqiang; Niu Zhichuan

    2010-01-01

    GaSb films with AlSb/GaSb compound buffer layers were grown by molecular beam epitaxy on GaAs (001) substrates. The crystal quality and optical properties were studied by high resolution transition electron microscopy and low temperature photoluminescence spectra (PL), respectively. It was found that the AlSb/GaSb compound buffer layers can restrict the dislocations into GaSb epilayers. The intensity of PL spectra of GaSb layer becomes large with the increasing the periods of AlSb/GaSb superlattices, indicating that the optical quality of GaSb films is improved.

  11. Model-based characterization of ventilatory stability using spontaneous breathing

    OpenAIRE

    Nemati, Shamim; Edwards, Bradley A.; Sands, Scott A.; Berger, Philip J.; Wellman, Andrew; Verghese, George C.; Malhotra, Atul; Butler, James P.

    2011-01-01

    Cyclic ventilatory instabilities are widely attributed to an increase in the sensitivity or loop gain of the chemoreflex feedback loop controlling ventilation. A major limitation in the conventional characterization of this feedback loop is the need for labor-intensive methodologies. To overcome this limitation, we developed a method based on trivariate autoregressive modeling using ventilation, end-tidal Pco2 and Po2; this method provides for estimation of the overall “loop gain” of the resp...

  12. Consciously controlled breathing decreases the high-frequency component of heart rate variability by inhibiting cardiac parasympathetic nerve activity.

    Science.gov (United States)

    Sasaki, Konosuke; Maruyama, Ryoko

    2014-07-01

    Heart rate variability (HRV), the beat-to-beat alterations in heart rate, comprises sympathetic and parasympathetic nerve activities of the heart. HRV analysis is used to quantify cardiac autonomic regulation. Since respiration could be a confounding factor in HRV evaluation, some studies recommend consciously controlled breathing to standardize the method. However, it remains unclear whether controlled breathing affects HRV measurement. We compared the effects of controlled breathing on HRV with those of spontaneous breathing. In 20 healthy volunteers, we measured respiratory frequency (f), tidal volume, and blood pressure (BP) and recorded electrocardiograms during spontaneous breathing (14.8 ± 0.7 breaths/min) and controlled breathing at 15 (0.25 Hz) and 6 (0.10 Hz) breaths/min. Compared to spontaneous breathing, controlled breathing at 0.25 Hz showed a higher heart rate and a lower high-frequency (HF) component, an index of parasympathetic nerve activity, although the f was the same. During controlled breathing at 0.10 Hz, the ratio of the low frequency (LF) to HF components (LF/HF), an index of sympathetic nerve activity, increased greatly and HF decreased, while heart rate and BP remained almost unchanged. Thus, controlled breathing at 0.25 Hz, which requires mental concentration, might inhibit parasympathetic nerve activity. During controlled breathing at 0.10 Hz, LF/HF increases because some HF subcomponents are synchronized with f and probably move into the LF band. This increment leads to misinterpretation of the true autonomic nervous regulation. We recommend that the respiratory pattern of participants should be evaluated before spectral HRV analysis to correctly understand changes in autonomic nervous regulation.

  13. Molecular beam epitaxial growth of AlSb/InAsSb heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuwei [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 (China); Department of Physics, Tsinghua University, Beijing, 100084 (China); Zhang, Yang, E-mail: zhang_yang@semi.ac.cn [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 (China); Guan, Min; Cui, Lijie; Li, Yanbo; Wang, Baoqiang; Zhu, Zhanping; Zeng, Yiping [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 (China)

    2014-09-15

    Highlights: • AlSb/InAsSb heterostructures have been successfully grown by MBE with electron mobility exceeding 16,000 cm{sup 2}/V s. • We present a new shutter sequence to reduce interface mixing and accurate control of Sb composition in InAsSb alloy. • Higher temperature could be applied for InAsSb growth with good crystalline quality, allowing relatively higher growth temperature for the subsequent AlSb barrier. • Raman spectra is used to examine interface mixing between AlSb and InAsSb layers. - Abstract: AlSb/InAsSb heterostructures have been successfully grown on GaAs substrate by modulated molecular-beam epitaxy (MMBE). New shutter sequence has been presented and room temperature mobility of 16,170 cm{sup 2}/V s has been achieved with our non-intentionally doped structures. With a view for optimization, we analyze variation of electron mobility induced by growth temperature and InAsSb thickness. By increasing growth temperature and thickness of InAsSb, improvement of electron mobility has been observed. With our optimized AlSb/InAsSb heterostructures, accurate control of composition in InAsSb alloy and reduced interface mixing have been confirmed by X-Ray diffraction and Raman spectroscopy measurements.

  14. Molecular beam epitaxial growth of AlSb/InAsSb heterostructures

    International Nuclear Information System (INIS)

    Zhang, Yuwei; Zhang, Yang; Guan, Min; Cui, Lijie; Li, Yanbo; Wang, Baoqiang; Zhu, Zhanping; Zeng, Yiping

    2014-01-01

    Highlights: • AlSb/InAsSb heterostructures have been successfully grown by MBE with electron mobility exceeding 16,000 cm 2 /V s. • We present a new shutter sequence to reduce interface mixing and accurate control of Sb composition in InAsSb alloy. • Higher temperature could be applied for InAsSb growth with good crystalline quality, allowing relatively higher growth temperature for the subsequent AlSb barrier. • Raman spectra is used to examine interface mixing between AlSb and InAsSb layers. - Abstract: AlSb/InAsSb heterostructures have been successfully grown on GaAs substrate by modulated molecular-beam epitaxy (MMBE). New shutter sequence has been presented and room temperature mobility of 16,170 cm 2 /V s has been achieved with our non-intentionally doped structures. With a view for optimization, we analyze variation of electron mobility induced by growth temperature and InAsSb thickness. By increasing growth temperature and thickness of InAsSb, improvement of electron mobility has been observed. With our optimized AlSb/InAsSb heterostructures, accurate control of composition in InAsSb alloy and reduced interface mixing have been confirmed by X-Ray diffraction and Raman spectroscopy measurements

  15. Respiratory hypoalgesia? Breath-holding, but not respiratory phase modulates nociceptive flexion reflex and pain intensity.

    Science.gov (United States)

    Jafari, Hassan; Van de Broek, Karlien; Plaghki, Léon; Vlaeyen, Johan W S; Van den Bergh, Omer; Van Diest, Ilse

    2016-03-01

    Several observations suggest that respiratory phase (inhalation vs. exhalation) and post-inspiratory breath-holds could modulate pain and the nociceptive reflex. This experiment aimed to investigate the role of both mechanisms. Thirty-two healthy participants received supra-threshold electrocutaneous stimulations to elicit both the Nociceptive Flexion Reflex (NFR) and pain, either during spontaneous inhalations or exhalations, or during three types of instructed breath-holds: following exhalation, at mid-inhalation and at full-capacity inhalation. Whether the electrocutaneous stimulus was applied during inhalation or exhalation did not affect the NFR or pain. Self-reported pain was reduced and the NFR was increased during breath-holding compared to spontaneous breathing. Whereas the type of breath-hold did not impact on self-reported pain, breath-holds at full-capacity inhalation and following exhalation were associated with a lower NFR amplitude compared to breath-holds at mid-inhalation. The present findings confirm that breath-holding can modulate pain (sensitivity) and suggest that both attentional distraction and changes in vagal activity may underlie the observed effects. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Breathing Like a Fish

    Science.gov (United States)

    Katsioloudis, Petros J.

    2010-01-01

    Being able to dive and breathe underwater has been a challenge for thousands of years. In 1980, Fuji Systems of Tokyo developed a series of prototype gills for divers as a way of demonstrating just how good its membranes are. Even though gill technology has not yet reached the point where recipients can efficiently use implants to dive underwater,…

  17. Breathing, feeding, and neuroprotection

    National Research Council Canada - National Science Library

    Homma, Ikuo; Shioda, S

    2006-01-01

    ... of knowledge of brain functions and morphology. Akiyoshi Hosoyamada, M.D., Ph.D. President Showa University, Tokyo 142-8555, Japan December 2005Preface Brain research is on the march, with several advanced technical developments and new findings uncovered almost daily. Within the brain-research fields, we focus on breathing, neuroprotection, an...

  18. The Breath of Chemistry

    DEFF Research Database (Denmark)

    Josephsen, Jens

    The present preliminary text is a short thematic presentation in biological inorganic chemistry meant to illustrate general and inorganic (especially coordination) chemistry in biochemistry. The emphasis is on molecular models to explain features of the complicated mechanisms essential to breathing...

  19. Radon-in-breath measurement

    International Nuclear Information System (INIS)

    Leach, V.A.

    1981-01-01

    A review of literature on the area of radon breath measurements has shown that respiratory factors have been largely ignored. The history of breathing room-air radon concentrations and the variations in respiratory parameters for each individual have been the major contributing factors for poor reproducibility in radon breath measurements performed by past researchers

  20. AlSb/InAs/AlSb quantum wells

    Science.gov (United States)

    Kroemer, Herbert

    1990-01-01

    Researchers studied the InAs/AlSb system recently, obtaining 12nm wide quantum wells with room temperature mobilities up to 28,000 cm(exp 2)/V center dot S and low-temperature mobilities up to 325,000 cm(exp 2)/V center dot S, both at high electron sheet concentrations in the 10(exp 12)/cm(exp 2) range (corresponding to volume concentrations in the 10(exp 18)/cm(exp 2) range). These wells were not intentionally doped; the combination of high carrier concentrations and high mobilities suggest that the electrons are due to not-intentional modulation doping by an unknown donor in the AlSb barriers, presumably a stoichiometric defect, like an antisite donor. Inasmuch as not intentionally doped bulk AlSb is semi-insulating, the donor must be a deep one, being ionized only by draining into the even deeper InAs quantum well. The excellent transport properties are confirmed by other observations, like excellent quantum Hall effect data, and the successful use of the quantum wells as superconductive weak links between Nb electrodes, with unprecendentedly high critical current densities. The system is promising for future field effect transistors (FETs), but many processing problems must first be solved. Although the researchers have achieved FETs, the results so far have not been competitive with GaAs FETs.

  1. Interfacial reactions and band offsets in the AlSb/GaSb/ZnTe material system

    OpenAIRE

    Yu, E. T.; Phillips, M. C.; Chow, D. H.; Collins, D. A.; Wang, M. W.; McCaldin, J. O.; McGill, T. C.

    1992-01-01

    We have used x-ray photoelectron spectroscopy to measure valence-band offsets in situ for AlSb/ZnTe, AlSb/GaSb, and GaSb/ZnTe(100) heterojunctions grown by molecular-beam epitaxy. For the AlSb/ZnTe heterojunction, a valence-band offset ΔEv=0.42±0.07 eV was obtained. Our data indicated that an intermediate compound, containing Al and Te, was formed at the AlSb/ZnTe(100) interface. Measurements of the AlSb/GaSb and GaSb/ZnTe valence-band offsets demonstrated a clear violation of band offset tra...

  2. [Sb4Au4Sb4]2−: A designer all-metal aromatic sandwich

    International Nuclear Information System (INIS)

    Tian, Wen-Juan; You, Xue-Rui; Guo, Jin-Chang; Li, Da-Zhi; Wang, Ying-Jin; Sun, Zhong-Ming; Zhai, Hua-Jin

    2016-01-01

    We report on the computational design of an all-metal aromatic sandwich, [Sb 4 Au 4 Sb 4 ] 2− . The triple-layered, square-prismatic sandwich complex is the global minimum of the system from Coalescence Kick and Minima Hopping structural searches. Following a standard, qualitative chemical bonding analysis via canonical molecular orbitals, the sandwich complex can be formally described as [Sb 4 ] + [Au 4 ] 4− [Sb 4 ] + , showing ionic bonding characters with electron transfers in between the Sb 4 /Au 4 /Sb 4 layers. For an in-depth understanding of the system, one needs to go beyond the above picture. Significant Sb → Au donation and Sb ← Au back-donation occur, redistributing electrons from the Sb 4 /Au 4 /Sb 4 layers to the interlayer Sb–Au–Sb edges, which effectively lead to four Sb–Au–Sb three-center two-electron bonds. The complex is a system with 30 valence electrons, excluding the Sb 5s and Au 5d lone-pairs. The two [Sb 4 ] + ligands constitute an unusual three-fold (π and σ) aromatic system with all 22 electrons being delocalized. An energy gap of ∼1.6 eV is predicted for this all-metal sandwich. The complex is a rare example for rational design of cluster compounds and invites forth-coming synthetic efforts.

  3. AlGaSb Buffer Layers for Sb-Based Transistors

    Science.gov (United States)

    2010-01-01

    1.5 lm to 3.0 lm buffer layers of AlSb and AlGaSb accommo- dating the lattice mismatch. We demonstrate that high electron mobility in the InAs (>20,000...buffer layers to accommodate the 4% to 15% lattice mismatch. AlSb or alloys of AlGaSb have usually been used as buffer layers. Nguyen et al. achieved...because it is much less reactive than pure AlSb .18 The substrate temperature was then low- ered to 500C for growth of an additional 100 nm of Al0.8Ga0.2Sb

  4. Learn More Breathe Better

    Centers for Disease Control (CDC) Podcasts

    2011-11-16

    Chronic obstructive pulmonary disease (COPD) is a serious lung disease that makes breathing very difficult and can affect your quality of life. Learn the causes of COPD and what you can do to prevent it.  Created: 11/16/2011 by National Center for Chronic Disease Prevention and Health Promotion, Division of Adult and Community Health (NCCDPHP, DACH).   Date Released: 11/16/2011.

  5. The atomistic mechanism for Sb segregation and As displacement of Sb in InSb(001) surfaces

    Science.gov (United States)

    Anderson, Evan M.; Millunchick, Joanna M.

    2018-01-01

    Interfacial broadening occurs in mixed-anion alloy heterostructures such as InAs/InAsSb due to both Sb-segregation and As-for-Sb exchange. In order to determine the atomistic mechanisms for these processes, we conduct ab initio calculations coupled with a cluster expansion formalism to determine the surface reconstructions of the pure and As-exposed InSb(001) surfaces. This approach provides a predicted phase diagram for pure InSb that is in better agreement with experiments. Namely, the α2(2 × 4) and α3c(4 × 4) structures are ultimately stable at 0K, but the α(4 × 3) and α2c(2 × 6) are within 1 meV/Å2. Exposure of the InSb(001) surface to As results in the As atoms infiltrating into the crystal and displacing subsurface Sb, thus providing the atomistic mechanisms for experimental observations of the As-for-Sb exchange reaction and Sb segregation. Experiments show that the widely reported A-(1 × 3) reconstruction is actually comprised of multiple reconstructions, which is consistent with the prediction of several nearly stable possible reconstructions.

  6. [TMJ, eating and breathing].

    Science.gov (United States)

    Cheynet, F

    2016-09-01

    The study of the relationship between temporomandibular joints (TMJ), mastication and ventilation and the involvement of these two functions in the genesis of primary Temporomandibular Disorders (TMD) and in some dentofacial deformities, was initiated in France, more than 30years, by Professor Raymond Gola. Once criticized the weakness of the scientific literature in this domain, the originality of the TMJ within the masticatory system is recalled with its huge adaptation potential to very different biomechanical constraints according to the age and masticatory activities during the day. But the biomechanics of the masticatory system does not stop at night and the positions of the mandible and head during sleep should be studied carefully. In case of nocturnal mouth breathing with open mouth, the predominant sleeping position (generating small but long-term strengths) may be deleterious to the condyle-disc complex, to the surrounding muscles and the occlusal relationships. Some condyle-disc displacements and asymmetric malocclusions occur in this long portion of life what sleep, especially as oral breathing leads to a lot of dysfunctions (low position of the tongue, labio-lingual dysfunctions, exacerbation of bruxism sleep…). The aim of this work was to share our multidisciplinary experience of the biomechanical consequences of the nocturnal mouth breathing on the face involving orthodontists, maxillofacial surgeons, ENT, allergists, speech therapists, physiotherapists and radiologists. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  7. Hemodinâmica de diferentes frações inspiradas de oxigênio em cães submetidos à infusão contínua de propofol sob ventilação espontânea Hemodyinamic effects of several inspired oxygen fractions in spontaneously breathing dogs submitted to continuous infusion of propofol

    Directory of Open Access Journals (Sweden)

    Newton Nunes

    2008-06-01

    Full Text Available Avaliaram-se os efeitos do fornecimento de diferentes frações inspiradas de oxigênio (FiO2 sobre os parâmetros hemodinâmicos em cães submetidos à infusão contínua de propofol e mantidos em ventilação espontânea. Foram utilizados oito cães, os quais foram empregados em cinco grupos com diferentes FiO2, G100 (FiO2 = 1, G80 (FiO2 = 0,8, G60 (FiO2 = 0,6, G40 (FiO2 = 0,4 e G20 (FiO2 = 0,21, respeitando-se um intervalo de dez dias entre cada procedimento anestésico. Os animais foram induzidos e mantidos sob anestesia com propofol na dose de 0,7mg kg-1 min-1 e, após a intubação orotraqueal, iniciou-se o fornecimento de oxigênio conforme a FiO2 determinada para cada grupo. As primeiras mensurações, da freqüência cardíaca (FC, das pressões arteriais sistólica, diastólica e média (PAS, PAD e PAM, da resistência vascular periférica e pulmonar (RPT e RPV, do débito cardíaco (DC; da pressão venosa central (PVC, da pressão média da artéria pulmonar (PMAP, da pressão média capilar pulmonar (PMCP, da pressão parcial de oxigênio (PaO2 e do dióxido de carbono (PaCO2 no sangue arterial, foram efetuadas 30 minutos após o início da infusão do anestésico (M0, seguidas de intervalos de 15 minutos (M15, M30, M45 e M60. Os dados numéricos obtidos foram submetidos à Análise de Variância, seguida pelo teste Tukey (PThe effects of several inspired oxygen fractions (FiO2 in hemodynamics parameters in spontaneously breathing dogs submitted to continuous infusion of propofol were evaluated. Eight adult mongrel dogs were studied and the animals underwent five anesthesias. In each procedure the patient was submitted to a different FiO2, thereby resulting in five groups, namely: G100 (FiO2 = 1, G80 (FiO2 = 0.8, G60 (FiO2 =0.6, G40 (FiO2 = 0.4, and G20 (FiO2 = 0.21. The dose of propofol was sufficient to abolish protector reflex and ensure endotracheal intubation, followed by immediate continuous infusion of that drug (0.7mg kg-1

  8. Redundant Sb condensation on GaSb epilayers grown by molecular beam epitaxy during cooling procedure

    International Nuclear Information System (INIS)

    Arpapay, B.; Şahin, S.; Arıkan, B.; Serincan, U.

    2014-01-01

    The effect of four different cooling receipts on the surface morphologies of unintentionally-doped GaSb epilayers on GaSb (100) substrates grown by molecular beam epitaxy is reported. Those receipts include three different Sb beam equivalent pressure (BEP) levels and two different termination temperatures. Surface morphologies of epilayers were examined by wet etching, surface profiler, atomic force microscopy, scanning electron microscopy and Raman spectroscopy. The results demonstrate that during the cooling period, a Sb BEP of 4.00 × 10 −4 Pa at a termination temperature of 400 °C induces a smooth surface without Sb condensation whereas same Sb BEP at a termination temperature of 350 °C forms a 300 nm thick Sb layer on the surface. In addition, it is revealed that by applying a wet etching procedure and using a surface profiler it is possible to identify this condensed layer from the two-sloped feature of mesa profile. - Highlights: • Sb beam flux termination temperature is crucial for redundant Sb condensation. • Sb beam flux level has a role on the thickness of redundant condensed Sb layer. • Redundant Sb layer thickness can be measured by two-sloped mesa structure

  9. Alternative synthetic route for the heterometallic CO-releasing [Sb@Rh12(CO27]3− icosahedral carbonyl cluster and synthesis of its new unsaturated [Sb@Rh12(CO24]4− and dimeric [{Sb@Rh12Sb(CO25}2Rh(CO2PPh3]7− derivatives

    Directory of Open Access Journals (Sweden)

    Cristina Femoni

    2016-10-01

    Full Text Available The hetero-metallic [Sb@Rh12(CO27]3− cluster has been known as for over three decades thanks to Vidal and co-workers, and represents the first example of an E-centered (E=heteroatom icosahedral rhodium carbonyl cluster. However, its synthesis required high temperature (140–160 °C and elevated CO pressure (400 atm. Applying the redox condensation method for cluster preparation, we herein report a new synthetic, high-yield route for preparing [Sb@Rh12(CO27]3− under much milder conditions of temperature and pressure. Notably, when the same synthesis was carried out under N2 instead of CO atmosphere, the new isostructural but unsaturated derivative [Sb@Rh12(CO24]4− was obtained, for which we report the full X-ray structural characterization. This species represents one of the few examples of an icosahedral cluster disobeying the electron-counting Wade-Mingos rules, possessing less than the expected 170 cluster valence electrons (CVEs. Judging from IR monitoring, the two species can be obtained one from the other by switching between N2 and CO atmosphere, making [Sb@Rh12(CO27]3− a spontaneous CO-releasing molecule. Finally, the study of the chemical reactivity of [Sb@Rh12(CO27]3− with PPh3 allowed us to obtain the new [{Sb@Rh12Sb(CO25}2Rh(CO2PPh3]7− dimeric compound, for which we herein report the full X-ray structural and 31P NMR analyses.

  10. Heart dose reduction by prone deep inspiration breath hold in left-sided breast irradiation.

    Science.gov (United States)

    Mulliez, Thomas; Veldeman, Liv; Speleers, Bruno; Mahjoubi, Khalil; Remouchamps, Vincent; Van Greveling, Annick; Gilsoul, Monique; Berwouts, Dieter; Lievens, Yolande; Van den Broecke, Rudy; De Neve, Wilfried

    2015-01-01

    Cardiac disease has been related to heart dose after left-sided breast radiotherapy. This trial evaluates the heart sparing ability and feasibility of deep inspiration breath hold (DIBH) in the prone position for left-sided whole breast irradiation (WBI). Twelve patients underwent CT-simulation in supine shallow breathing (SB), supine DIBH, prone SB and prone DIBH. A validation cohort of 38 patients received prone SB and prone DIBH CT-scans; the last 30 patients were accepted for prone DIBH treatment. WBI was planned with a prescription dose of 40.05 Gy. DIBH was able to reduce (p<0.001) heart dose in both positions, with results for prone DIBH at least as favorable as for supine DIBH. Mean heart dose was lowered from 2.2 Gy for prone SB to 1.3 Gy for prone DIBH (p<0.001), while preserving the lung sparing ability of prone positioning. Moreover prone DIBH nearly consistently reduced mean heart dose to less then 2 Gy, regardless of breast volume. All patients were able to perform the simulation procedure, 28/30 patients were treated with prone DIBH. This trial demonstrates the ability and feasibility of prone DIBH to acquire optimal heart and lung sparing for left-sided WBI. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Compressed breathing gas and liquefied breathing... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed breathing gas and liquefied breathing gas containers; minimum requirements. (a) Compressed breathing gas and...

  12. 121Sb and 125Te nuclear inelastic scattering in Sb2Te3 under high pressure

    Science.gov (United States)

    Simon, R. E.; Sergueev, I.; Kantor, I.; Kantor, A.; Perßon, J.; Hermann, R. P.

    2014-12-01

    We investigated the lattice dynamics of Sb2Te3 under high pressure using 121Sb and 125Te nuclear inelastic scattering of synchrotron radiation. We measured the room temperature 121Sb and 125Te inelastic spectra at 15(1) GPa and 77(3) GPa and extracted the Te and Sb element specific density of phonon states of δ-Sb2Te3 at 77(3) GPa. X-ray diffraction confirms the sample to be in the cubic δ-Sb2Te3 phase with space group Im\\bar{3}m and lattice constant a=3.268(4) \\overset{\\circ}{A} . The total density of phonon states of δ-Sb2Te3 strongly resembles the one of amorphous GeSb2Te4, suggesting the presence of covalent bonding in contrast to the resonance bonding in α-Sb2Te3. From the density of phonon states of δ-Sb2Te3 a mean speed of sound of 2.61(6) km {{s}-1} and Debye temperatures of 278(10) K for Te and 296(10) K for Sb were determined.

  13. Density functional simulations of Sb-rich GeSbTe phase change alloys

    Science.gov (United States)

    Gabardi, S.; Caravati, S.; Bernasconi, M.; Parrinello, M.

    2012-09-01

    We generated models of the amorphous phase of Sb-rich GeSbTe phase change alloys by quenching from the melt within density functional molecular dynamics. We considered the two compositions Ge1Sb1Te1 and Ge2Sb4Te5. Comparison with previous results on the most studied Ge2Sb2Te5 allowed us to draw some conclusions on the dependence of the structural properties of the amorphous phase on the alloy composition. Vibrational and electronic properties were also scrutinized. Phonons at high frequencies above 200 cm-1 are localized in tetrahedra around Ge atoms in Sb-rich compounds as well as in Ge2Sb2Te5. All compounds are semiconducting in the amorphous phase, with a band gap in the range 0.7-1.0 eV.

  14. High quality InAsSb grown on InP substrates using AlSb/AlAsSb buffer layers

    International Nuclear Information System (INIS)

    Wu, B.-R.; Liao, C.; Cheng, K. Y.

    2008-01-01

    High quality InAsSb grown on semi-insulating InP substrates by molecular beam epitaxy was achieved using AlSb/AlAsSb structure as the buffer layer. A 1000 A InAsSb layer grown on top of 1 μm AlSb/AlAsSb buffer layer showed a room temperature electron mobility of ∼12 000 cm 2 /V s. High structural quality and low misfit defect density were also demonstrated in the InAsSb layer. This novel AlSb/AlAsSb buffer layer structure with the AlAsSb layer lattice matched to InP substrates could enhance the performance of optoelectronic devices utilizing 6.1 A family of compound semiconductor alloys

  15. FMWC Radar for Breath Detection

    DEFF Research Database (Denmark)

    Suhr, Lau Frejstrup; Tafur Monroy, Idelfonso; Vegas Olmos, Juan José

    breathing through walls. Other remote breath tracking systems has been presented that are based on the Ultra-wideband radar technique. However, these systems have two drawbacks. Firstly, they penetrate walls. It is therefore harder to contain the emitted radiation and they could be used for unsolicited...

  16. Patient's breath controls comfort devices

    Science.gov (United States)

    Schrader, M.; Carpenter, B.; Nichols, C. D.

    1972-01-01

    Patient assist system for totally disabled persons was developed which permits a person, so paralyzed as to be unable to move, to activate by breathing, a call system to summon assistance, turn the page of a book, ajust his bed, or do any one of a number of other things. System consists of patient assist control and breath actuated switch.

  17. Investigation into breath meditation: Phenomenological ...

    African Journals Online (AJOL)

    This integral heuristic phenomenological investigation records participants' experiences of a single session of breath meditation with special reference to psychotherapy and sport psychology. There were 8 participants, 4 men and 4 women, with mean age of 45 years and age range from 31 to 62 years. Various breathing ...

  18. Cutaneous stimulation and generation of breathing in the fetus.

    Science.gov (United States)

    Scarpelli, E M; Condorelli, S; Cosmi, E V

    1977-01-01

    The generation of spontaneous regular breathing by cutaneous stimulation and by direct electrical stimulation of the sciatic nerve was examined in six previously apneic mature fetal lambs in utero. The fetuses were stable throughout the course of the experiments: PaO2 less than or equal to 27 mm Hg, PaCO2 less than 44 mm Hg, pH 7.29-7.34, blood pressure and heart rate steady and normal. It is shown that electrical stimulation of the fetal skin (66 cps, 4.0 msec, 6 V, 0.77 ma) can be as effective as direct stimulation of the sciatic nerve (66 cps, 4.0 msec, 1.5 V, 0.08 ma) when the higher voltage and current are used. Mechanical cutaneous stimulation also produced spontaneous breathing which, however, was short lived compared with that produced by electrical stimuli. The results are consonant with our concept of activation and recruitment of quiescent respiratory center neurones by somatic sensory stimulation, and they give fundamental support to the clinical observation of others that cutaneous stimulation is effective for the treatment of apnea of prematurity. Speculation Somatic sensory stimuli from the skin may be important determinants of the onset of breathing in the fetus and newborn.

  19. Crystallographic study of the intermediate compounds SbZn, Sb3Zn4 and Sb2Zn3

    International Nuclear Information System (INIS)

    Adjadj, Fouzia; Belbacha, El-djemai; Bouharkat, Malek; Kerboub, Abdellah

    2006-01-01

    The processes of development of semiconductor ceramics made up of bismuth, antimony and zinc often require during their preparation to know the nature of the involved phases. For that, it is always essential to refer to the diagrams of balance between phases of the binary systems or ternary. We presented in this work the study by X-rays diffraction relating to the intermediate compounds SbZn, Sb 3 Zn 4 and Sb 2 Zn 3 . The analysis by X-rays is often useful to give supplement the results of the other experimental methods

  20. Breath of hospitality.

    Science.gov (United States)

    Škof, Lenart

    2016-12-01

    In this paper we outline the possibilities of an ethic of care based on our self-affection and subjectivity in the ethical spaces between-two. In this we first refer to three Irigarayan concepts - breath, silence and listening from the third phase of her philosophy, and discuss them within the methodological framework of an ethics of intersubjectivity and interiority. Together with attentiveness, we analyse them as four categories of our ethical becoming. Furthermore, we argue that self-affection is based on our inchoate receptivity for the needs of the other(s) and is thus dialectical in its character. In this we critically confront some epistemological views of our ethical becoming. We wind up this paper with a proposal for an ethics towards two autonomous subjects, based on care and our shared ethical becoming - both as signs of our deepest hospitality towards the other.

  1. Origin of enhanced visible light driven water splitting by (Rh, Sb)-SrTiO3.

    Science.gov (United States)

    Modak, Brindaban; Ghosh, Swapan K

    2015-06-21

    A systematic calculation, using hybrid density functional theory, has been carried out to investigate the origin of the enhancement of photo-conversion efficiency of Rh-doped SrTiO3 with codoping of Sb. In the case of Rh-doped SrTiO3, partially unoccupied states are introduced above the valence band, thus lowering the hole oxidation at the valence band (VB) drastically, which explains the poor oxygen evolution activity of Rh-doped SrTiO3. We show that the partially occupied t2g subset of the Rh 4d orbital is completely filled in the presence of Sb due to the transfer of the extra electron to the Rh center. As a result, acceptor states are completely passivated in the case of (Rh, Sb)-codoped SrTiO3 and a continuous band structure with reduced band gap is formed, which is responsible for the observed enhanced photocatalytic activity of (Rh, Sb)-codoped SrTiO3. We have shown that the relative positions of the band edges of (Rh, Sb)-codoped SrTiO3 with respect to the water redox levels are in favor of the spontaneous release of both hydrogen and oxygen during water splitting, which is consistent with the experimental observation. We have also studied the effect of codoping in different proportions (1 : 2 and 2 : 1) of Rh and Sb. Although 1 : 2 (Rh, Sb)-codoping leads to the formation of a clean band structure with the reduction of the band gap by a larger extent, it shows lower photo-conversion efficiency due to its charge non-compensated nature. In addition, the presence of acceptor states above the VB limits the oxygen evolution efficiency of 2 : 1 (Rh, Sb)-codoped SrTiO3. Thus, the present approach successfully reproduces the experimental features of the Rh-monodoped as well as (Rh, Sb)-codoped SrTiO3 and also explains their origin.

  2. Periodic breathing in healthy humans at exercise in hypoxia.

    Science.gov (United States)

    Hermand, Eric; Pichon, Aurélien; Lhuissier, François J; Richalet, Jean-Paul

    2015-01-01

    Periodic breathing is frequent in heart failure or ventilatory disorders during sleep, and common during sleep at high altitude, but has been rarely studied in wakefulness and during exercise. A retrospective analysis of ventilation from hypoxia exercise tests was realized in 82 healthy subjects separated into two groups with either high or low ventilatory response to hypoxia at exercise (HVRe). A fast Fourier transform spectral analysis of the breath-by-breath ventilation (V̇e) signal, O2 saturation, and end-tidal PCO2 evidenced a periodic pattern with a period of 11.1 to 12.0 s. The peak power of the V̇e spectrum was higher in the high HVRe group (P hypoxia (0 to 4,000 m altitude). The period of V̇e was shorter at exercise (vs. rest, P hypoxia (vs. normoxia, P hypoxia (P hypoxia was positively related with the ventilatory response to CO2 (HCVR). This novel observation suggests that healthy subjects demonstrate a spontaneous periodic breathing, not clearly observable at rest and in normoxia, but triggered by hypoxic exercise. The periodic pattern is enhanced in subjects with high HVRe and high HCVR, suggesting that oxygen and CO2 play synergistic roles in the modulation of these oscillations. Copyright © 2015 the American Physiological Society.

  3. Spontaneous uterine rupture

    African Journals Online (AJOL)

    ABSTRACT. Rupture of a gravid uterus is a surgical emergency. Predisposing factors include a scarred uterus. Spontaneous rupture of an unscarred uterus during pregnancy is a rare occurrence. We hereby present the case of a spontaneous complete uterine rupture at a gestational age of 34 weeks in a 35 year old patient ...

  4. Spontaneous intracranial hypotension.

    LENUS (Irish Health Repository)

    Fullam, L

    2012-01-31

    INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.

  5. AlGaSb/GaSb quantum wells grown on an optimized AlSb nucleation layer

    International Nuclear Information System (INIS)

    Gao Hanchao; Wen Cai; Wang Wenxin; Jiang Zhongwei; Tian Haitao; He Tao; Li Hui; Chen Hong

    2010-01-01

    Five-period AlGaSb/GaSb multiple quantum wells (MQW) are grown on a GaSb buffer. Through optimizing the AlSb nucleation layer, the low threading dislocation density of the MQW is found to be (2.50 ± 0.91) x 10 8 cm -2 in 1-μm GaSb buffer, as determined by plan-view transmission election microscopy (TEM) images. High resolution TEM clearly shows the presence of 90 0 misfit dislocations with an average spacing of 5.4 nm at the AlSb/GaAs interface, which effectively relieve most of the strain energy. In the temperature range from T = 26 K to 300 K, photoluminescence of the MQW is dominated by the ground state electron to ground state heavy hole (e1-hh1) transition, while a high energy shoulder clearly seen at T > 76 K can be attributed to the ground state electron to ground state light hole (e1-lh1) transition. (semiconductor materials)

  6. Diverse presentation of breath holding spells: two case reports with literature review.

    Science.gov (United States)

    Rathore, Geetanjali; Larsen, Paul; Fernandez, Cristina; Parakh, Manish

    2013-01-01

    Breath holding spells are a common and dramatic form of syncope and anoxic seizure in infancy. They are usually triggered by an emotional stimuli or minor trauma. Based on the color change, they are classified into 3 types, cyanotic, pallid, and mixed. Pallid breath holding spells result from exaggerated, vagally-mediated cardiac inhibition, whereas the more common, cyanotic breathholding spells are of more complex pathogenesis which is not completely understood. A detailed and accurate history is the mainstay of diagnosis. An EKG should be strongly considered to rule out long QT syndrome. Spontaneous resolution of breath-holding spells is usually seen, without any adverse developmental and intellectual sequelae. Rare cases of status epilepticus, prolonged asystole, and sudden death have been reported. Reassurance and education is the mainstay of therapy. Occasionally, pharmacologic intervention with iron, piracetam; atropine may be of benefit. Here we present 2 cases, one of each, pallid and cyanotic breath holding spells.

  7. Diverse Presentation of Breath Holding Spells: Two Case Reports with Literature Review

    Directory of Open Access Journals (Sweden)

    Geetanjali Rathore

    2013-01-01

    Full Text Available Breath holding spells are a common and dramatic form of syncope and anoxic seizure in infancy. They are usually triggered by an emotional stimuli or minor trauma. Based on the color change, they are classified into 3 types, cyanotic, pallid, and mixed. Pallid breath holding spells result from exaggerated, vagally-mediated cardiac inhibition, whereas the more common, cyanotic breathholding spells are of more complex pathogenesis which is not completely understood. A detailed and accurate history is the mainstay of diagnosis. An EKG should be strongly considered to rule out long QT syndrome. Spontaneous resolution of breath-holding spells is usually seen, without any adverse developmental and intellectual sequelae. Rare cases of status epilepticus, prolonged asystole, and sudden death have been reported. Reassurance and education is the mainstay of therapy. Occasionally, pharmacologic intervention with iron, piracetam; atropine may be of benefit. Here we present 2 cases, one of each, pallid and cyanotic breath holding spells.

  8. Diverse Presentation of Breath Holding Spells: Two Case Reports with Literature Review

    Science.gov (United States)

    Rathore, Geetanjali; Larsen, Paul; Fernandez, Cristina; Parakh, Manish

    2013-01-01

    Breath holding spells are a common and dramatic form of syncope and anoxic seizure in infancy. They are usually triggered by an emotional stimuli or minor trauma. Based on the color change, they are classified into 3 types, cyanotic, pallid, and mixed. Pallid breath holding spells result from exaggerated, vagally-mediated cardiac inhibition, whereas the more common, cyanotic breathholding spells are of more complex pathogenesis which is not completely understood. A detailed and accurate history is the mainstay of diagnosis. An EKG should be strongly considered to rule out long QT syndrome. Spontaneous resolution of breath-holding spells is usually seen, without any adverse developmental and intellectual sequelae. Rare cases of status epilepticus, prolonged asystole, and sudden death have been reported. Reassurance and education is the mainstay of therapy. Occasionally, pharmacologic intervention with iron, piracetam; atropine may be of benefit. Here we present 2 cases, one of each, pallid and cyanotic breath holding spells. PMID:24191206

  9. Intersubband light absorption by holes in InAsSb/AlSb quantum well heterostructures

    International Nuclear Information System (INIS)

    Pavlov, N V; Zegrya, G G

    2016-01-01

    The absorption coefficients of intersubband optical transitions in the valence band of the AlSb/InAs_0_._8_4Sb_0_._1_6/AlSb quantum wells in framework of the four-band Kane model. It is established that the light absorption by holes may lead to the laser generation breakdown. It is shown that we need to decrease the quantum well width to range a<6 nm to neutralize the negative influence of this effect. (paper)

  10. Thermodynamic stability studies of Ce-Sb compounds with Fe

    Science.gov (United States)

    Xie, Yi; Zhang, Jinsuo; Benson, Michael T.; Mariani, Robert D.

    2018-02-01

    Lanthanide fission products can migrate to the fuel periphery and react with cladding, causing fuel-cladding chemical interaction (FCCI). Adding a fuel additive dopant, such as Sb, can bind lanthanide, such as Ce, into metallic compounds and thus prevent migration. The present study focuses on the thermodynamic stability of Ce-Sb compounds when in contact with the major cladding constituent Fe by conducting diffusion couple tests. Ce-Sb compounds have shown high thermodynamic stability as they did not react with Fe. When Fe-Sb compounds contacted with Ce, Sb was separated out of Fe-Sb compounds and formed the more stable Ce-Sb compounds.

  11. High-Current GaSb/InAs(Sb) Nanowire Tunnel Field-Effect Transistors

    OpenAIRE

    Dey, Anil; Borg, Mattias; Ganjipour, Bahram; Ek, Martin; Dick Thelander, Kimberly; Lind, Erik; Thelander, Claes; Wernersson, Lars-Erik

    2013-01-01

    We present electrical characterization of GaSb/InAs(Sb) nanowire tunnel field-effect transistors. The broken band alignment of the GaSb/InAs(Sb) heterostructure is exploited to allow for interband tunneling without a barrier, leading to high ON-current levels. We report a maximum drive current of 310 μA/μm at Vds = 0.5 V. Devices with scaled gate oxides display transconductances up to gm = 250 mS/mm at Vds = 300 mV, which are normalized to the nanowire circumference at the axial heterojunction...

  12. Defect Structure of High-Temperature-Grown GaMnSb/GaSb

    International Nuclear Information System (INIS)

    Romanowski, P.; Bak-Misiuk, J.; Dynowska, E.; Domagala, J.Z.; Wojciechowski, T.; Jakiela, R.; Sadowski, J.; Barcz, A.; Caliebe, W.

    2010-01-01

    GaMnSb/GaSb(100) layers with embedded MnSb inclusions have been grown at 720 K using MBE technique. This paper presents the investigation of the defect structure of Ga1-xMnxSb layers with different content of manganese (up to x = 0.07). X-ray diffraction method using conventional and synchrotron radiation was applied. Dimensions and shapes of inclusions were detected by scanning electron microscopy. Depth profiles of elements were measured using secondary ion mass spectroscopy technique. (authors)

  13. Microstructural characterization of a rapidly solidified Al-5 Sb alloy

    International Nuclear Information System (INIS)

    Zhang Zhonghua; Bian Xiufang; Wang Yan

    2003-01-01

    In the present work, the microstructure of a melt-spun Al-5 Sb alloy has been characterized using X-ray diffraction and transmission electron microscopy. The phases present in the melt-spun Al-5 Sb alloy were determined to be the equilibrium α-Al and AlSb, identical to those in the ingot-cast alloy. The microstructure of the melt-spun Al-5 Sb alloy is composed of primary AlSb phase embedded in the matrix comprising α-Al cells with intercellular nanoscale AlSb particles, different from that of the ingot-cast alloy composed of the primary AlSb phase within an α-Al/AlSb eutectic matrix. Rapid solidification has a marked effect on the morphology, size and distribution of the primary AlSb phase in the melt-spun Al-5 Sb alloy. Furthermore, some orientation relationships were determined in the melt-spun alloy

  14. Electroluminescence in p-InAs/AlSb/InAsSb/AlSb/p(n)-GaSb type II heterostructures with deep quantum wells at the interface

    International Nuclear Information System (INIS)

    Mikhailova, M. P.; Ivanov, E. V.; Moiseev, K. D.; Yakovlev, Yu. P.; Hulicius, E.; Hospodkova, A.; Pangrac, J.; Simecek, T.

    2010-01-01

    Luminescent characteristics of asymmetric p-InAs/AlSb/InAsSb/AlSb/p-GaSb type II heterostructures with deep quantum wells at the heterointerface are studied. The heterostructures were grown by metalorganic vapor phase epitaxy. Intense positive and negative luminescence was observed in the range of photon energies of 0.3-0.4 eV with a forward and reverse bias, respectively. Dependences of the spectra and intensities for positive and negative luminescence on the pumping current and on the temperature are studied in the range of 77-380 K. It is established that, at a temperature higher than 75 deg. C, intensity of negative luminescence surpasses that of positive luminescence by 60%. The suggested heterostructures can be used as lightemitting diodes (photodiodes) with switched positive and negative luminescence in the mid-IR spectral range of 3-4 μm.

  15. Practice It: Deep Conscious Breathing Exercise

    Science.gov (United States)

    No time to sit and breathe? No problem; take your breathing practice with you! Deep conscious breathing can also be done with the eyes open wherever you happen to be—simply pause and take two to three full deep breaths (inhale deeply and exhale completely).

  16. Growth mechanisms of GaSb heteroepitaxial films on Si with an AlSb buffer layer

    Energy Technology Data Exchange (ETDEWEB)

    Vajargah, S. Hosseini; Botton, G. A. [Department of Materials Science and Engineering, McMaster University, Hamilton, Ontario L8S 4L7 (Canada); Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Canadian Centre for Electron Microscopy, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Ghanad-Tavakoli, S. [Centre for Emerging Device Technologies, McMaster University, Hamilton, Ontario L8S 4L7 (Canada); Preston, J. S.; Kleiman, R. N. [Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Centre for Emerging Device Technologies, McMaster University, Hamilton, Ontario L8S 4L7 (Canada); Department of Engineering Physics, McMaster University, Hamilton, Ontario L8S 4L7 (Canada)

    2013-09-21

    The initial growth stages of GaSb epilayers on Si substrates and the role of the AlSb buffer layer were studied by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Heteroepitaxy of GaSb and AlSb on Si both occur by Volmer-Weber (i.e., island mode) growth. However, the AlSb and GaSb islands have distinctly different characteristics as revealed through an atomic-resolution structural study using Z-contrast of HAADF-STEM imaging. While GaSb islands are sparse and three dimensional, AlSb islands are numerous and flattened. The introduction of 3D island-forming AlSb buffer layer facilitates the nucleation of GaSb islands. The AlSb islands-assisted nucleation of GaSb islands results in the formation of drastically higher quality planar film at a significantly smaller thickness of films. The interface of the AlSb and GaSb epilayers with the Si substrate was further investigated with energy dispersive X-ray spectrometry to elucidate the key role of the AlSb buffer layer in the growth of GaSb epilayers on Si substrates.

  17. Growth mechanisms of GaSb heteroepitaxial films on Si with an AlSb buffer layer

    International Nuclear Information System (INIS)

    Vajargah, S. Hosseini; Botton, G. A.; Ghanad-Tavakoli, S.; Preston, J. S.; Kleiman, R. N.

    2013-01-01

    The initial growth stages of GaSb epilayers on Si substrates and the role of the AlSb buffer layer were studied by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Heteroepitaxy of GaSb and AlSb on Si both occur by Volmer-Weber (i.e., island mode) growth. However, the AlSb and GaSb islands have distinctly different characteristics as revealed through an atomic-resolution structural study using Z-contrast of HAADF-STEM imaging. While GaSb islands are sparse and three dimensional, AlSb islands are numerous and flattened. The introduction of 3D island-forming AlSb buffer layer facilitates the nucleation of GaSb islands. The AlSb islands-assisted nucleation of GaSb islands results in the formation of drastically higher quality planar film at a significantly smaller thickness of films. The interface of the AlSb and GaSb epilayers with the Si substrate was further investigated with energy dispersive X-ray spectrometry to elucidate the key role of the AlSb buffer layer in the growth of GaSb epilayers on Si substrates

  18. Visualizing Breath using Digital Holography

    Science.gov (United States)

    Hobson, P. R.; Reid, I. D.; Wilton, J. B.

    2013-02-01

    Artist Jayne Wilton and physicists Peter Hobson and Ivan Reid of Brunel University are collaborating at Brunel University on a project which aims to use a range of techniques to make visible the normally invisible dynamics of the breath and the verbal and non-verbal communication it facilitates. The breath is a source of a wide range of chemical, auditory and physical exchanges with the direct environment. Digital Holography is being investigated to enable a visually stimulating articulation of the physical trajectory of the breath as it leaves the mouth. Initial findings of this research are presented. Real time digital hologram replay allows the audience to move through holographs of breath-born particles.

  19. Formation of strained interfaces in AlSb/InAs multilayers grown by molecular beam epitaxy for quantum cascade lasers

    Energy Technology Data Exchange (ETDEWEB)

    Nicolaï, J.; Warot-Fonrose, B.; Gatel, C., E-mail: christophe.gatel@cemes.fr; Ponchet, A. [CEMES CNRS-UPR 8011, Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse (France); Transpyrenean Associated Laboratory for Electron Microscopy (TALEM), CEMES-INA, CNRS-Universidad de Zaragoza, Toulouse (France); Teissier, R.; Baranov, A. N. [IES CNRS-UMR 5214, 34095 Montpellier (France); Magen, C. [Transpyrenean Associated Laboratory for Electron Microscopy (TALEM), CEMES-INA, CNRS-Universidad de Zaragoza, Toulouse (France); Laboratorio de Microscopías Avanzadas (LMA), Instituto de Nanociencia de Aragón (INA)—ARAID and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50018 Zaragoza (Spain)

    2015-07-21

    Structural and chemical properties of InAs/AlSb interfaces have been studied by transmission electron microscopy. InAs/AlSb multilayers were grown by molecular beam epitaxy with different growth sequences at interfaces. The out-of-plane strain, determined using high resolution microscopy and geometrical phase analysis, has been related to the chemical composition of the interfaces analyzed by high angle annular dark field imaging. Considering the local strain and chemistry, we estimated the interface composition and discussed the mechanisms of interface formation for the different growth sequences. In particular, we found that the formation of the tensile AlAs-type interface is spontaneously favored due to its high thermal stability compared to the InSb-type interface. We also showed that the interface composition could be tuned using an appropriate growth sequence.

  20. Formation of strained interfaces in AlSb/InAs multilayers grown by molecular beam epitaxy for quantum cascade lasers

    International Nuclear Information System (INIS)

    Nicolaï, J.; Warot-Fonrose, B.; Gatel, C.; Ponchet, A.; Teissier, R.; Baranov, A. N.; Magen, C.

    2015-01-01

    Structural and chemical properties of InAs/AlSb interfaces have been studied by transmission electron microscopy. InAs/AlSb multilayers were grown by molecular beam epitaxy with different growth sequences at interfaces. The out-of-plane strain, determined using high resolution microscopy and geometrical phase analysis, has been related to the chemical composition of the interfaces analyzed by high angle annular dark field imaging. Considering the local strain and chemistry, we estimated the interface composition and discussed the mechanisms of interface formation for the different growth sequences. In particular, we found that the formation of the tensile AlAs-type interface is spontaneously favored due to its high thermal stability compared to the InSb-type interface. We also showed that the interface composition could be tuned using an appropriate growth sequence

  1. Blue breath holding is benign.

    OpenAIRE

    Stephenson, J B

    1991-01-01

    In their recent publication in this journal, Southall et al described typical cyanotic breath holding spells, both in otherwise healthy children and in those with brainstem lesions and other malformations. Their suggestions regarding possible autonomic disturbances may require further study, but they have adduced no scientific evidence to contradict the accepted view that in the intact child blue breath holding spells are benign. Those families in which an infant suffers an 'apparently life t...

  2. Molecular Beam Epitaxy of GaSb on GaAs Substrates with AlSb Buffer Layers

    International Nuclear Information System (INIS)

    Zhi-Qiang, Zhou; Ying-Qiang, Xu; Rui-Ting, Hao; Bao, Tang; Zheng-Wei, Ren; Zhi-Chuan, Niu

    2009-01-01

    We investigate the molecular beam epitaxy growth of GaSb films on GaAs substrates using AlSb buffer layers. Optimization of AlSb growth parameter is aimed at obtaining high GaSb crystal quality and smooth GaSb surface. The optimized growth temperature and thickness of AlSb layers are found to be 450° C and 2.1 nm, respectively. A rms surface roughness of 0.67nm over 10 × 10 μm 2 is achieved as a 0.5μm GaSb film is grown under optimized conditions

  3. Enhanced non-eupneic breathing following hypoxic, hypercapnic or hypoxic-hypercapnic gas challenges in conscious mice.

    Science.gov (United States)

    Getsy, Paulina M; Davis, Jesse; Coffee, Gregory A; May, Walter J; Palmer, Lisa A; Strohl, Kingman P; Lewis, Stephen J

    2014-12-01

    C57BL6 mice display non-eupneic breathing and spontaneous apneas during wakefulness and sleep as well as markedly disordered breathing following cessation of a hypoxic challenge. We examined whether (1) C57BL6 mice display marked non-eupneic breathing following hypercapnic or hypoxic-hypercapnic challenges, and (2) compared the post-hypoxia changes in non-eupneic breathing of C57BL6 mice to those of B6AF1 (57BL6 dam × A/J sire) and Swiss-Webster mice, which display different ventilatory responses than C57BL6 mice. C57BL6 mice displayed marked increases in respiratory frequency and non-eupneic breathing upon return to room-air after hypoxic (10% O2, 90% N2), hypercapnic (5% CO2, 21% O2 and 74% N2) and hypoxic-hypercapnic (10% O2, 5% CO2 and 85% N2) challenges. B6AF1 mice displayed less tachypnea and reduced non-eupneic breathing post-hypoxia, whereas Swiss-Webster mice displayed robust tachypnea with minimal increases in non-eupneic breathing post-hypoxia. These studies demonstrate that non-eupneic breathing increases after physiologically-relevant hypoxic-hypercapnic challenge in C57BL6 mice and suggest that further studies with these and B6AF1 and Swiss-Webster mice will help define the genetics of non-eupneic breathing. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. InSb semiconductors and (In,Mn)Sb diluted magnetic semiconductors. Growth and properties

    Energy Technology Data Exchange (ETDEWEB)

    Tran, Lien

    2011-04-13

    This dissertation describes investigations of the growth by molecular beam epitaxy and the characterization of the semiconductor InSb as well as the diluted magnetic semiconductor (DMS) In{sub 1-x}Mn{sub x}Sb. The InSb films were grown on GaAs (001) substrate and Si (001) offcut by 4 toward (110) substrate up to a thickness of about 2 {mu}m, in spite of a large lattice mismatch between the epi-layer and substrate (14.6% between InSb and GaAs, and 19.3% between InSb and Si). After optimizing the growth conditions, the best InSb films grown directly on GaAs without any special technique results in a high crystal quality, low noise, and an electron mobility of 41100 cm{sup 2}/V s Vs with associated electron concentration of 2.9.10{sup 6} cm{sup -3} at 300 K. Such structures could be used, for example, for infrared detector structures. The growth of InSb on Si, however, is a challenge. In order to successfully grow InSb on Si, tilted substrates and the insertion of buffer layers were used, which helps to reduce the lattice mismatch as well as the formation of defects, and hence to improve the crystal quality. An electron mobility of 24000 cm{sup 2}/V s measured at 300 K, with an associated carrier concentration of 2.6.10{sup 1}6 cm{sup -3} is found for the best sample that was grown at 340 C with a 0.06 {mu}m-thick GaSb/AlSb superlattice buffer layer. The smaller value of electron mobility (compared to the best GaAsbased sample) is related to a higher density of microtwins and stacking faults as well as threading dislocations in the near-interface region as shown by transmission electron microscopy. Deep level noise spectra indicate the existence of deep levels in both GaAs and Si-based samples. The samples grown on Si exhibit the lowest Hooge factor at 300 K, lower than the samples grown on GaAs. Taking the optimized growth conditions of InSb/GaAs, the diluted magnetic semiconductor In{sub 1-x}Mn{sub x}Sb/GaAs (001) is prepared by adding a few percent of Mn into the

  5. Standardization of exhaled breath condensate (EBC) collection using a feedback regulated breathing pattern

    Science.gov (United States)

    Collection of exhaled breath condensate (EBC) fluid by cooling of expired breath is a potentially valuable approach for the detection of biomarkers associated with disease or exposure to xenobiotics. EBC is generally collected using unregulated breathing patterns, perceived to el...

  6. Surface Reconstruction Phase Diagrams for InAs, AlSb, and GaSb

    National Research Council Canada - National Science Library

    Bracker, A. S; Yang, M. J; Bnnett, B. R; Culbertson, J. C; Moore, W. J

    2000-01-01

    ... for optimizing growth conditions. Phase boundaries for InAs (0 0 1) [(2*4)->(4*2)], AlSb (0 0 1) [c(4*4)->(1*3)], and GaSb (0 0 1) [(2*5)_>(1*3)] are presented as a function of substrate temperature and Group V-limited growth rate...

  7. Structure study of a GaSb/AlSb strained layer superlattice

    International Nuclear Information System (INIS)

    Pan, C.K.; Finstad, T.G.; Speriosu, V.S.; Zheng, D.C.; Chu, W.K.; Nicolet, M.A.; Barrett, J.H.

    1985-01-01

    Due to the lattice mismatch, a superlattice consisting of alternating layers of GaSb and AlSb will be strained. The specimen used in the present study was grown by molecular beam epitaxy on a GaSb (100) substrate and had ten 30-nm thick layers of each material. For layers of this thickness, the strain is expected to be purely elastic with no misfit dislocations. Because of the substrate's thickness, it and the GaSb layers are unstrained, and the strain in the AlSb layers is easily calculable from elasticity theory. The differing strains will cause crystallographic axes inclined to the growth direction to have slightly different directions in the two types of layers. For (110) this difference or kink angle is calculated to be 0.374 0 . Measurements to determine this angle were performed by ion channeling and backscattering and by X rays

  8. Study of GaSb and AlSb surface superstructures based on the (100) planes

    International Nuclear Information System (INIS)

    Lubyshev, D.I.; Gonzalez-Borrero, P.P.; Marega Junior, E.; La Scala Junior, N.; Basmaji, P

    1995-01-01

    Full text. Surface superstructure (SS) on semiconductor surfaces determines properties like Schottky barrier heights, vacancy densities and surface adatom migration length at the molecular beam epitaxy (MBE). In this work we have studied the evolution of surface structures as function of the substrate temperature on the (100) Al Sb and Ga Sb by RHEED analysis. Atomic smooth surfaces were produced by MBE on the (100) Ga As substrates. As the temperature of the Sb-rich surfaces of Al Sb and Ga Sb increases from the room temperature, it is observed that the surface superstructure is changed to the (4 x 2)metal stabilized one. On the Ga Sb (100) surfaces were observed the following number of SS: the (2 x 5)Sb-stabilized, (1 x 3) and (2 x 4)Ga stabilized SS. The phase transition from the (2 x 5)Sb-stabilized SS to (1 x 3) ones goes through unusual changing of superstructure strike positions. This can be explained considering the SS rotation during the phase transition relatively to the bulk lattice. The strike intensities for different azimuths of the (2 x 5)SS are altered in a factor 2, indicating a lower SS ordering across the domain axe (x2). On the Al Sb surfaces the following SS sequence were detected: at low temperature there is a superposition of the (6 x 1) and (2 x 1) SS, at higher temperatures (3 x 1), (3 x 3) and (2 x 4)Al-stabilized structures. We have supposed that the low temperature SS (6 x 1)+(2 x 1) have more than one monolayer coverage by Sb. We have also observed form the first time evidences of mixed surface superstructures (6 x 1)+(2 x 1) and SS (3 x 3). (author)

  9. DWPF simulant CPC studies for SB8

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, D. C.; Zamecnik, J. R.

    2013-06-25

    The Savannah River National Laboratory (SRNL) accepted a technical task request (TTR) from Waste Solidification Engineering to perform simulant tests to support the qualification of Sludge Batch 8 (SB8) and to develop the flowsheet for SB8 in the Defense Waste Processing Facility (DWPF). These efforts pertained to the DWPF Chemical Process Cell (CPC). Separate studies were conducted for frit development and glass properties (including REDOX). The SRNL CPC effort had two primary phases divided by the decision to drop Tank 12 from the SB8 constituents. This report focuses on the second phase with SB8 compositions that do not contain the Tank 12 piece. A separate report will document the initial phase of SB8 testing that included Tank 12. The second phase of SB8 studies consisted of two sets of CPC studies. The first study involved CPC testing of an SB8 simulant for Tank 51 to support the CPC demonstration of the washed Tank 51 qualification sample in the SRNL Shielded Cells facility. SB8-Tank 51 was a high iron-low aluminum waste with fairly high mercury and moderate noble metal concentrations. Tank 51 was ultimately washed to about 1.5 M sodium which is the highest wash endpoint since SB3-Tank 51. This study included three simulations of the DWPF Sludge Receipt and Adjustment Tank (SRAT) cycle and Slurry Mix Evaporator (SME) cycle with the sludge-only flowsheet at nominal DWPF processing conditions and three different acid stoichiometries. These runs produced a set of recommendations that were used to guide the successful SRNL qualification SRAT/SME demonstration with actual Tank 51 washed waste. The second study involved five SRAT/SME runs with SB8-Tank 40 simulant. Four of the runs were designed to define the acid requirements for sludge-only processing in DWPF with respect to nitrite destruction and hydrogen generation. The fifth run was an intermediate acid stoichiometry demonstration of the coupled flowsheet for SB8. These runs produced a set of processing

  10. Comparison of carbon monoxide (CO) single breath pulmonary diffusing capacity with non-rebreathing, open-circuit CO pulmonary diffusing capacity in healthy children.

    Science.gov (United States)

    Suman, Oscar E; Thomas, Suchmor; Beck, Kenneth C; Mlcak, Ronald P; Herndon, David N

    2006-11-01

    The standard technique for assessing pulmonary diffusing capacity of the lungs (DL) for carbon monoxide (CO) is the single breath (SB) technique. SB_DLco in children can be problematic because it requires a vital capacity >1.5 L. We have developed an open-circuit technique (OC), which uses the wash-in of CO over a series of 8-10 normal breaths that does not require rebreathing. In this study, we compared the SB_DLco against the OC_DLco. Nineteen healthy children between 7 and 18 years performed SB_DLco and OC_DLco tests. The mean SB_DLco was significantly larger than the mean OC_DLco. The mean difference OC_DLco minus SB_ DLco was: -2.92 +/- 4.21 ml/min/mm Hg, though the difference was negatively correlated with the mean of the two (r = 0.73). The lower mean OC_DLco was in part due to lower lung volume (as measured by alveolar volume (VA)) during the maneuver. In both groups there was a positive correlation between VA and DLco, and the mean VA was -2.17 +/- 1.07 L lower using OC compared to SB. The difference was again negatively correlated with the mean (r = 0.82). The mean OC minus SB difference in DLco/VA was: 6.06 +/- 1.98 ml/min/mm Hg/L, though this difference was positively correlated with the mean, r = 0.76. We found a good correlation between both techniques for DLco, VA, and DLco/VA. The OC offers the advantage of minimal subject cooperation, and may be preferable to use in children.

  11. Evaluation of Breath-Holding Test in Assessment of Peripheral Chemoreflex Sensitivity in Patients with Chronic Heart Failure.

    Science.gov (United States)

    Trembach, Nikita; Zabolotskikh, Igor

    2017-01-01

    The sensitivity of peripheral chemoreflex is a marker of the severity of heart failure and the prognosis of the outcome in these patients. The assessment of chemosensitivity in these patients remains an actual problem. The aim of the study was to explore the relationship between a Breath-Holding Test (BHT) and single-breath carbon dioxide test and to evaluate the reliability of both tests in patients with Heart Failure (HF). The study was performed in 43 patients with chronic heart failure. All subjects underwent BHT and single-breath carbon dioxide (CB-CO 2 ), the evaluation of both tests was repeated a month later. Relationship of two test was evaluated by correlation analysis. Reliability was assessed with calculation of Standard Error of Measurement (SEM), Coefficient of Variation (CV) and Intraclass Correlation Coefficient (ICC). The duration of the breath-holding was inversely correlated to the result of CB-CO 2 test (r = -0.86 at first measurement and r = -0.79 after a month) The ICC was 0.87 (95%CI: 0.78-0.93) for SB-CO 2 test and 0,93 (95%CI: 0.88-0.96) for BHT, the CV was 24% for SB-CO 2 and 13% for BHT. SEM for SB-CO 2 test was 0.04 L / min / mmHg and limits of variation was 0.11 L / min / mmHg; SEM for BHT was 3.6 sec and limits of variation was10 sec. Breath-holding test is a reliable and safe method for assessing the sensitivity of peripheral chemoreflex to carbon dioxide in patients with heart failure.

  12. Slow Breathing and Hypoxic Challenge: Cardiorespiratory Consequences and Their Central Neural Substrates

    Science.gov (United States)

    Critchley, Hugo D.; Nicotra, Alessia; Chiesa, Patrizia A.; Nagai, Yoko; Gray, Marcus A.; Minati, Ludovico; Bernardi, Luciano

    2015-01-01

    Controlled slow breathing (at 6/min, a rate frequently adopted during yoga practice) can benefit cardiovascular function, including responses to hypoxia. We tested the neural substrates of cardiorespiratory control in humans during volitional controlled breathing and hypoxic challenge using functional magnetic resonance imaging (fMRI). Twenty healthy volunteers were scanned during paced (slow and normal rate) breathing and during spontaneous breathing of normoxic and hypoxic (13% inspired O2) air. Cardiovascular and respiratory measures were acquired concurrently, including beat-to-beat blood pressure from a subset of participants (N = 7). Slow breathing was associated with increased tidal ventilatory volume. Induced hypoxia raised heart rate and suppressed heart rate variability. Within the brain, slow breathing activated dorsal pons, periaqueductal grey matter, cerebellum, hypothalamus, thalamus and lateral and anterior insular cortices. Blocks of hypoxia activated mid pons, bilateral amygdalae, anterior insular and occipitotemporal cortices. Interaction between slow breathing and hypoxia was expressed in ventral striatal and frontal polar activity. Across conditions, within brainstem, dorsal medullary and pontine activity correlated with tidal volume and inversely with heart rate. Activity in rostroventral medulla correlated with beat-to-beat blood pressure and heart rate variability. Widespread insula and striatal activity tracked decreases in heart rate, while subregions of insular cortex correlated with momentary increases in tidal volume. Our findings define slow breathing effects on central and cardiovascular responses to hypoxic challenge. They highlight the recruitment of discrete brainstem nuclei to cardiorespiratory control, and the engagement of corticostriatal circuitry in support of physiological responses that accompany breathing regulation during hypoxic challenge. PMID:25973923

  13. Performance improvement of Ge-Sb-Te material by GaSb doping for phase change memory

    International Nuclear Information System (INIS)

    Lu, Yegang; Zhang, Zhonghua; Song, Sannian; Cheng, Limin; Song, Zhitang; Shen, Xiang; Wang, Guoxiang; Dai, Shixun

    2013-01-01

    Effects of GaSb doping on phase change characteristics of Ge-Sb-Te material are investigated by in situ resistance and x-ray diffraction measurement, optical spectroscopy, and x-ray photoelectron spectroscopy. The crystallization temperature and data retention of Ge-Sb-Te material increase significantly by the addition of GaSb, which results from the high thermal stability of amorphous GaSb. In addition, GaSb-doped Ge-Sb-Te material exhibits faster crystallization speed due to the change in electronic states as a result of the formation of chemical bonds with Ga element. Incorporation of GaSb is highly effective way to enhance the comprehensive performance of Ge-Sb-Te material for phase change memory.

  14. Crystal orientations of InSb films grown on a Si(111) substrate by inserting AlSb buffer layer

    International Nuclear Information System (INIS)

    Murata, K.; Ahmad, N.B.; Mori, M.; Tambo, T.; Maezawa, K.

    2008-01-01

    The heteroepitaxial growth of InSb film via AlSb buffer layer on a Si(111) substrate was performed in an ultra high vacuum. The grown InSb films were characterized by X-ray diffraction and atomic force microscopy. XRD patterns (Φ-scan) of the samples showed different epitaxial relationship between InSb/Si and InSb/AlSb/Si. It is found that surface condition has a significant influence on the growth of InSb films and the surface of InSb films became rough due to the high mixture ratio of domains. The two-step growth procedure was also tried to further improve the crystal quality of the InSb films. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. The growth of GaSb/Al0.33Ga0.67Sb MQW on n-Silicon (1 0 0) with Al0.66Ga0.34Sb/AlSb SPS layers

    International Nuclear Information System (INIS)

    Yoen, Kyu Hyoek; Song, Jin Dong; Lee, Eun Hye; Jang, Hye Joung; Bae, Min Han; Kim, Jun Young; Han, Il Ki; Choi, Won Jun

    2014-01-01

    Highlights: • GaSb/Al 0.33 GaSb MQW layer was grown on Si (1 0 0) by MBE. • The effect of miscut angle of Si substrate was studied. • A lot of twins were removed by Al 0.66 Ga 0.34 Sb/AlSb SPS layers. • Good quality of GaSb/Al 0.33 Ga 0.67 Sb MQW layers were proved by PL spectra. • Optimum growth temperature of the AlSb buffer layer was studied. - Abstract: GaSb/Al 0.33 Ga 0.67 Sb multi-quantum well (MQW) film on n-Si (1 0 0) substrates is grown by molecular beam epitaxy. The effects of a miscut angle of the Si substrate (0°, 5°, and 7°) on the properties of an AlSb layer were also studied. The suppression of the anti-phase domains (APD) was observed at a miscut angle of 5° on Si (1 0 0). It was found that the growth temperature in the range of 510–670 °C affects the quality of AlSb layers on Si. Low root-mean-square surface (RMS) roughness values of 3–5 nm were measured by atomic force microscopy at growth temperatures ranging from 550 °C to 630 °C. In addition, Al 0.66 Ga 0.34 Sb/AlSb short period superlattice (SPS) layers were used to overcome problems associated with a large lattice mismatch. The RMS values of samples with a SPS were partially measured at approximately ∼1 nm, showing a larger APD surface area than samples without a SPS layer. Bright-field cross-sectional transmission electron microscopy images of the GaSb/Al 0.33 Ga 0.67 Sb MQW, the AlSb buffer layer and the Al 0.66 Ga 0.34 Sb/AlSb SPS layers show that numerous twins from the AlSb/Si interface were removed by the AlSb buffer layer and the Al 0.66 Ga 0.34 Sb/AlSb SPS. The GaSb/Al 0.33 Ga 0.67 Sb MQW PL spectra were obtained at 300 K and 10 K with a fixed excitation power of 103 mW. Emission peaks appeared at 1758 nm and 1620 nm, respectively

  16. Silver behaviour in InSb

    International Nuclear Information System (INIS)

    Khlystovskaya, M.D.; Kirichenko, L.S.; Popkov, A.N.; Kiseleva, E.V.

    1976-01-01

    Specimens of InSb, alloyed with silver at concentrations of 2.4x10 14 to 1.1x10 15 cm -3 , have been obtained and investigated. The distribution of Ag along the length of ingots was studied. The effective coefficient of silver distribution in InSb was found to be equal to 5.7x10 -6 . The limit solubility of silver was evaluated by the disturbance of the smooth front of solidification and the appearance of cubstructures and second phases on polished sections, said solubility corresponds to the concentration of approximately 1x10 15 cm -3 of silver. The properties of InSb, alloyed with Ag with various degrees of compensation by residual donors and tellurium were investigated. It was found that in the p-n junction range the specific resistance of specimens rises to 2.3x10 3 Ohm.cm

  17. Breathing adapted radiotherapy for breast cancer: comparison of free breathing gating with the breath-hold technique

    DEFF Research Database (Denmark)

    Korreman, Stine Sofia; Pedersen, Anders N; Nøttrup, Trine Jakobi

    2005-01-01

    BACKGROUND AND PURPOSE: Adjuvant radiotherapy after breast-conserving surgery for breast cancer implies a risk of late cardiac and pulmonary toxicity. This is the first study to evaluate cardiopulmonary dose sparing of breathing adapted radiotherapy (BART) using free breathing gating......, and to compare this respiratory technique with voluntary breath-hold. PATIENTS AND METHODS: 17 patients were CT-scanned during non-coached breathing manoeuvre including free breathing (FB), end-inspiration gating (IG), end-expiration gating (EG), deep inspiration breath-hold (DIBH) and end-expiration breath......-hold (EBH). The Varian Real-time Position Management system (RPM) was used to monitor respiratory movement and to gate the scanner. For each breathing phase, a population based internal margin (IM) was estimated based on average chest wall excursion, and incorporated into an individually optimised three...

  18. Sb(V) reactivity with human blood components: redox effects.

    Science.gov (United States)

    López, Silvana; Aguilar, Luis; Mercado, Luis; Bravo, Manuel; Quiroz, Waldo

    2015-01-01

    We assessed the reactivity of Sb(V) in human blood. Sb(V) reactivity was determined using an HPLC-HG-AFS hyphenated system. Sb(V) was partially reduced to Sb(III) in blood incubation experiments; however, Sb(III) was a highly unstable species. The addition of 0.1 mol L(-1) EDTA prevented Sb(III) oxidation, thus enabling the detection of the reduction of Sb(V) to Sb(III). The transformation of Sb(V) to Sb(III) in human whole blood was assessed because the reduction of Sb(V) in human blood may likely generate redox side effects. Our results indicate that glutathione was the reducing agent in this reaction and that Sb(V) significantly decreased the GSH/GSSG ratio from 0.32 ± 0.09 to 0.07 ± 0.03. Moreover, the presence of 200 ng mL(-1) of Sb(V) increased the activity of superoxide dismutase from 4.4 ± 0.1 to 7.0 ± 0.4 U mL(-1) and decreased the activity of glutathione peroxidase from 62 ± 1 to 34 ± 2 nmol min(-1) mL(-1).

  19. Sb(V reactivity with human blood components: redox effects.

    Directory of Open Access Journals (Sweden)

    Silvana López

    Full Text Available We assessed the reactivity of Sb(V in human blood. Sb(V reactivity was determined using an HPLC-HG-AFS hyphenated system. Sb(V was partially reduced to Sb(III in blood incubation experiments; however, Sb(III was a highly unstable species. The addition of 0.1 mol L(-1 EDTA prevented Sb(III oxidation, thus enabling the detection of the reduction of Sb(V to Sb(III. The transformation of Sb(V to Sb(III in human whole blood was assessed because the reduction of Sb(V in human blood may likely generate redox side effects. Our results indicate that glutathione was the reducing agent in this reaction and that Sb(V significantly decreased the GSH/GSSG ratio from 0.32 ± 0.09 to 0.07 ± 0.03. Moreover, the presence of 200 ng mL(-1 of Sb(V increased the activity of superoxide dismutase from 4.4 ± 0.1 to 7.0 ± 0.4 U mL(-1 and decreased the activity of glutathione peroxidase from 62 ± 1 to 34 ± 2 nmol min(-1 mL(-1.

  20. Compositional and structural characterisation of GaSb and GaInSb

    International Nuclear Information System (INIS)

    Corregidor, V.; Alves, E.; Alves, L.C.; Barradas, N.P.; Duffar, Th.; Franco, N.; Marques, C.; Mitric, A.

    2005-01-01

    Low band gap III-V semiconductors are researched for applications in thermophotovoltaic technology. GaSb crystal is often used as a substrate. Ga 1-x In x Sb is also a promising substrate material, because its lattice parameters can be adjusted by controlling x. We used a new method to synthesise GaSb and GaInSb, in which a high frequency alternate magnetic field is used to heat, to melt and to mix the elements. We present a compositional and structural characterisation of the materials using a combination of complementary techniques. Rutherford backscattering was used to determine accurately the composition of the GaSb. With proton induced X-ray emission in conjunction with a 3 x 3 μm 2 micro-beam we studied the homogeneity of the samples. Structural analysis and phase identification were done with X-ray diffraction. The results for GaSb show a homogeneous composition while the GaInSb samples were found to be strongly heterogeneous at the end of the ingot. The ingots produced are competitive feed material, when compared to other growth techniques, to be used in a second step for the production of good quality ternary crystals

  1. Blue breath holding is benign.

    Science.gov (United States)

    Stephenson, J B

    1991-01-01

    In their recent publication in this journal, Southall et al described typical cyanotic breath holding spells, both in otherwise healthy children and in those with brainstem lesions and other malformations. Their suggestions regarding possible autonomic disturbances may require further study, but they have adduced no scientific evidence to contradict the accepted view that in the intact child blue breath holding spells are benign. Those families in which an infant suffers an 'apparently life threatening event' deserve immense understanding and help, and it behoves investigators to exercise extreme care and self criticism in the presentation of new knowledge which may bear upon their management and their morale. PMID:2001115

  2. AlSb precipitate evolution during Sb implantation in Al: experiment and theory

    International Nuclear Information System (INIS)

    Kant, R.A.; Myers, S.M.; Picraux, S.T.

    1977-01-01

    Precipitate evolution during ion implantation has been studied in the model system Sb-implanted Al. Transmission electron microscopy was used to determine the size distribution of AlSb crystallites as a function of fluence, flux, and sample temperature. There was a dramatic increase in average size, accompanied by a decrease in number density, for increasing fluence, for decreasing flux, and for increasing temperature. A new theoretical model for the evolution of the precipitate size distribution has been developed which incorporates both thermal processes and implantation effects. Numerical solutions for the AlSb system using physically realistic parameters agree qualitatively with the experimentally observed evolutions

  3. Early abnormalities of post-sigh breathing in a mouse model of Rett syndrome.

    Science.gov (United States)

    Voituron, N; Zanella, S; Menuet, C; Lajard, A M; Dutschmann, M; Hilaire, G

    2010-02-28

    Rett syndrome is a neurodevelopmental disease accompanied by complex, disabling symptoms, including breathing symptoms. Because Rett syndrome is caused by mutations in the transcriptional repressor methyl-CpG-binding protein 2 (MeCP2), Mecp2-deficient mice have been generated as experimental model. Males of Mecp2-deficient mice (Mecp2(-/y)) breathe normally at birth but show abnormal respiratory responses to hypoxia and hypercapnia from postnatal day 25 (P25). After P30, Mecp2(-/y) mice develop breathing symptoms reminiscent of Rett syndrome, aggravating until premature death at around P60. Using plethysmography, we analyzed the sighs and the post-sigh breathing pattern of unrestrained wild type male mice (WT) and Mecp2(-/y) mice from P15 to P60. Sighs are spontaneous large inspirations known to prevent lung atelectasis and to improve alveolar oxygenation. However, Mecp2(-/y) mice show early abnormalities of post-sigh breathing, with long-lasting post-sigh apnoeas, reduced tidal volume when eupnoea resumes and lack of post-sigh bradypnoea which develop from P15, aggravate with age and possibly contribute to breathing symptoms to come. Copyright 2010 Elsevier B.V. All rights reserved.

  4. Spontaneous Atraumatic Mediastinal Hemorrhage

    Directory of Open Access Journals (Sweden)

    Morkos Iskander BSc, BMBS, MRCS, PGCertMedEd

    2013-04-01

    Full Text Available Spontaneous atraumatic mediastinal hematomas are rare. We present a case of a previously fit and well middle-aged lady who presented with acute breathlessness and an increasing neck swelling and spontaneous neck bruising. On plain chest radiograph, widening of the mediastinum was noted. The bruising was later confirmed to be secondary to mediastinal hematoma. This life-threatening diagnostic conundrum was managed conservatively with a multidisciplinary team approach involving upper gastrointestinal and thoracic surgeons, gastroenterologists, radiologists, intensivists, and hematologists along with a variety of diagnostic modalities. A review of literature is also presented to help surgeons manage such challenging and complicated cases.

  5. TEM observations of a rapidly solidified Al-20 Sb alloy

    International Nuclear Information System (INIS)

    Wang Yan; Zhang Zhonghua; Zheng Shaohua; Bian Xiufang

    2004-01-01

    In the present work, the microstructural characterization of a melt-spun Al-20 Sb alloy has been carried out using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The phases present in the melt-spun Al-20 Sb alloy were determined to be α-Al and AlSb, identical to those in the ingot-cast alloy. The microstructure of the melt-spun Al-20 Sb alloy is dominantly composed of primary AlSb dendrites embedded in the α-Al matrix, different from that of the ingot-cast alloy composed of primary AlSb plates within an α-Al/AlSb eutectic matrix. In addition, some areas comprise primary AlSb particles within the α-Al matrix in the melt-spun alloy

  6. Large hh-lh splitting energy for InAs/AlSb/GaSb based N-structure photodetectors

    Science.gov (United States)

    Akel, K.; Hostut, M.; Tansel, T.; Ergun, Y.

    2018-01-01

    We investigate the band properties of InAs/AlSb/GaSb (N-structure) and InAs/GaSb material based type II superlattice (T2SL) photodedectors. The superlattice empirical pseudopotential method is used to define band-structures such as the bandgap and heavy hole-light hole (hh-lh) splitting energies in the mid-wavelength infrared range (MWIR) and long wavelength range (LWIR). The calculations are carried out on the variation of AlSb/GaSb layer thickness for (InAs)10.5/(AlSb)x/(GaSb)9-x and the variation of InAs layer thickness for (InAs)x/(AlSb)3/(GaSb)6 T2SL structures at 77 K. For the same bandgap energy of 229 meV (5.4 μm in wavelength), hh-lh splitting energy is calculated as 194 meV for the (InAs)7.5/(AlSb)3/(GaSb)6 structure compared to the (InAs)10.5/(GaSb)9 structure with hh-lh splitting energy of 91 meV within the MWIR. Long wavelength performance of InAs/AlSb/GaSb structure shows superior electronic properties over the standard InAs/GaSb T2SL structure with larger hh-lh splitting energy which is larger than the bandgap energy. The best result is obtained for (InAs)17/(AlSb)3/(GaSb)6 with the minimum bandgap of 128 meV with hh-lh splitting energy of 194 meV, which is important for suppressing the Auger recombination process. These values are very promising for a photodetector design in both MWIR and LWIR in high temperature applications.

  7. Oral breathing and speech disorders in children

    Directory of Open Access Journals (Sweden)

    Silvia F. Hitos

    2013-07-01

    Conclusion: Mouth breathing can affect speech development, socialization, and school performance. Early detection of mouth breathing is essential to prevent and minimize its negative effects on the overall development of individuals.

  8. InSb semiconductors and (In,Mn)Sb diluted magnetic semiconductors: Growth and properties

    International Nuclear Information System (INIS)

    Tran, Lien

    2011-01-01

    This dissertation describes investigations of the growth by molecular beam epitaxy and the characterization of the semiconductor InSb as well as the diluted magnetic semiconductor (DMS) In 1-x Mn x Sb. The InSb films were grown on GaAs (001) substrate and Si (001) offcut by 4 toward (110) substrate up to a thickness of about 2 μm, in spite of a large lattice mismatch between the epi-layer and substrate (14.6% between InSb and GaAs, and 19.3% between InSb and Si). After optimizing the growth conditions, the best InSb films grown directly on GaAs without any special technique results in a high crystal quality, low noise, and an electron mobility of 41100 cm 2 /V s Vs with associated electron concentration of 2.9.10 6 cm -3 at 300 K. Such structures could be used, for example, for infrared detector structures. The growth of InSb on Si, however, is a challenge. In order to successfully grow InSb on Si, tilted substrates and the insertion of buffer layers were used, which helps to reduce the lattice mismatch as well as the formation of defects, and hence to improve the crystal quality. An electron mobility of 24000 cm 2 /V s measured at 300 K, with an associated carrier concentration of 2.6.10 1 6 cm -3 is found for the best sample that was grown at 340 C with a 0.06 μm-thick GaSb/AlSb superlattice buffer layer. The smaller value of electron mobility (compared to the best GaAsbased sample) is related to a higher density of microtwins and stacking faults as well as threading dislocations in the near-interface region as shown by transmission electron microscopy. Deep level noise spectra indicate the existence of deep levels in both GaAs and Si-based samples. The samples grown on Si exhibit the lowest Hooge factor at 300 K, lower than the samples grown on GaAs. Taking the optimized growth conditions of InSb/GaAs, the diluted magnetic semiconductor In 1-x Mn x Sb/GaAs (001) is prepared by adding a few percent of Mn into the host material InSb during growth. I have

  9. Volatile sulphur compounds in morning breath of human volunteers

    NARCIS (Netherlands)

    Snel, Johannes; Burgering, Maurits; Smit, Bart; Noordman, Wouter; Tangerman, Albert; Winkel, Edwin G.; Kleerebezem, Michiel

    Objective: Morning breath contains elevated concentrations of volatile sulphur components (VSCs). Therefore, morning breath is recognised as a surrogate target for interventions on breath quality. Nevertheless, factors influencing morning breath are poorly understood. Our aim was to evaluate

  10. Volatile sulphur compounds in morning breath of human volunteers.

    NARCIS (Netherlands)

    Snel, J.; Burgering, M.; Smit, B.; Noordman, W.; Tangerman, A.; Winkel, E.G.; Kleerebezem, M.

    2011-01-01

    OBJECTIVE: morning breath contains elevated concentrations of volatile sulphur components (VSCs). Therefore, morning breath is recognised as a surrogate target for interventions on breath quality. Nevertheless, factors influencing morning breath are poorly understood. Our aim was to evaluate

  11. Highly strained AlAs-type interfaces in InAs/AlSb heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Vallet, M., E-mail: maxime.vallet@cemes.fr; Warot-Fonrose, B.; Gatel, C.; Nicolai, J.; Ponchet, A. [CEMES CNRS-UPR 8011, Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse (France); Transpyrenean Associated Laboratory for Electron Microscopy (TALEM), CEMES-INA, CNRS-Universidad de Zaragoza, Toulouse (France); Claveau, Y.; Combe, N. [CEMES CNRS-UPR 8011, Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse (France); Magen, C. [Transpyrenean Associated Laboratory for Electron Microscopy (TALEM), CEMES-INA, CNRS-Universidad de Zaragoza, Toulouse (France); Laboratorio de Microscopias Avanzadas (LMA), Instituto de Nanociencia de Aragon (INA)—ARAID and Departamento de Fisica de la Materia Condensada, Universidad de Zaragoza, 50018 Zaragoza (Spain); Teissier, R.; Baranov, A. N. [Institute of Electronics and Systems, UMR 5214 CNRS – University of Montpellier, 34095 Montpellier (France)

    2016-05-23

    Spontaneously formed Al-As type interfaces of the InAs/AlSb system grown by molecular beam epitaxy for quantum cascade lasers were investigated by atomic resolution scanning transmission electron microscopy. Experimental strain profiles were compared to those coming from a model structure. High negative out-of-plane strains with the same order of magnitude as perfect Al-As interfaces were observed. The effects of the geometrical phase analysis used for strain determination were evidenced and discussed in the case of abrupt and huge variations of both atomic composition and bond length as observed in these interfaces. Intensity profiles performed on the same images confirmed that changes of chemical composition are the source of high strain fields at interfaces. The results show that spontaneously assembled interfaces are not perfect but extend over 2 or 3 monolayers.

  12. The effect of inert gas choice on multiple breath washout in healthy infants: differences in lung function outcomes and breathing pattern.

    Science.gov (United States)

    Gustafsson, Per M; Bengtsson, Lovisa; Lindblad, Anders; Robinson, Paul D

    2017-12-01

    The detrimental effects on breathing pattern during multiple breath inert gas washout (MBW) have been described with different inhaled gases [100% oxygen (O 2 ) and sulfur hexafluoride (SF 6 )] but detailed comparisons are lacking. N 2 - and SF 6 -based tests were performed during spontaneous quiet sleep in 10 healthy infants aged 0.7-1.3 yr using identical hardware. Differences in breathing pattern pre and post 100% O 2 and 4% SF 6 exposure were investigated, and the results obtained were compared [functional residual capacity (FRC) and lung clearance index (LCI)]. During 100% O 2 exposure. mean inspiratory flow ("respiratory drive") decreased transiently by mean (SD) 28 (9)% ( P pattern of change reversed. No significant effect on breathing pattern was observed during SF 6 testing. In vitro testing confirmed that technical artifacts did not explain these changes. Mean (SD) FRC and LCI in vivo were significantly higher with N 2 vs. SF 6 washout: 216 (33) vs. 186 (22) ml ( P pattern during test performance and the functional residual capacity and lung clearance index values obtained. Data suggest the detrimental effect of breathing pattern of 100% O 2 and movement of O 2 across the alveolar capillary membrane, with direct effects on MBW outcomes. SF 6 MBW during infancy avoids this and can be further optimized by addressing the sources of technical artifact identified in this work.

  13. 14CO2 in breath

    International Nuclear Information System (INIS)

    Rabinowitz, J.L.; Lopez-Majano, V.

    1981-01-01

    The diagnosis of metabolic disorders can be made by detecting 14 CO 2 in the breath. This is possible because 14 CO 2 can label any organic compound without any deteriorations in the nature of the compound. This type of analysis is dependable, noninvasive and simple to perform with a scintillation counter. (orig.)

  14. Submarines, Spacecraft, and Exhaled Breath

    Science.gov (United States)

    The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled b...

  15. Breathing retraining: a rational placebo?

    NARCIS (Netherlands)

    Garssen, B.; de Ruiter, C.; van Dyck, R.

    1992-01-01

    Breathing retraining of patients with Hyperventilation Syndrome (HVS) and/or panic disorder is discussed to evaluate its clinical effectiveness and to examine the mechanism that mediates its effect. In relation to this theoretical question, the validity of HVS as a scientific model is discussed and

  16. Functional Analysis and Intervention for Breath Holding.

    Science.gov (United States)

    Kern, Lee; And Others

    1995-01-01

    A functional analysis of breath-holding episodes in a 7-year-old girl with severe mental retardation and Cornelia-de-Lange syndrome indicated that breath holding served an operant function, primarily to gain access to attention. Use of extinction, scheduled attention, and a picture card communication system decreased breath holding. (Author/SW)

  17. 21 CFR 868.5620 - Breathing mouthpiece.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breathing mouthpiece. 868.5620 Section 868.5620...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5620 Breathing mouthpiece. (a) Identification. A breathing mouthpiece is a rigid device that is inserted into a patient's mouth and that...

  18. Relationships between breath ratios, spirituality and health ...

    African Journals Online (AJOL)

    The aim of this retrospective, quantitative study was to investigate relationships between breath ratios, spirituality perceptions and health perceptions, with special reference to breath ratios that best predict optimal health and spirituality. Significant negative correlations were found between breath ratios and spirituality ...

  19. Breath psychotherapy | Edwards | Inkanyiso: Journal of Humanities ...

    African Journals Online (AJOL)

    Breath psychotherapy is an approach that makes direct use of the breath in healing. There are many forms of breathbased healing: basic breathing and relaxation methods, with or without the practice of psychological skills such as imagery, centring and concentration; expressive physical and emotional techniques; ...

  20. Sulfuric Acid Corrosion of Low Sb - Pb Battery Alloys | Ntukogu ...

    African Journals Online (AJOL)

    The corrosion properties of low Sb - Pb alloys developed for maintenance free motive power industrial batteries was studied by a bare grid constant current method and compared to those of the conventional Pb- 6% Sb alloy. Low Sb-Pb alloys with Se and As grain refiners were found to have higher corrosion rates than the ...

  1. SULFURIC ACID CORROSION OF LOW Sb - Pb BATTERY ALLOYS

    African Journals Online (AJOL)

    user

    1983-09-01

    Sep 1, 1983 ... (Manuscript received February,1983). ABSTRACT. The corrosion properties of low Sb - Pb alloys developed for maintenance free motive power industrial batteries was studied by a bare grid constant current method and compared to those of the conventional. Pb- 6% Sb alloy. Low Sb-Pb alloys with Se and ...

  2. Microstructural characterization of a rapidly solidified Al-10 Sb alloy

    International Nuclear Information System (INIS)

    Wang Yan; Zhang Zhonghua; Geng Haoran; Wang Weimin; Bian Xiufang

    2006-01-01

    In the present work, the microstructure of a melt-spun Al-10 Sb alloy has been characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that rapid solidification has no influence on the phase constitution of the Al-10 Sb alloy. Moreover, the phase constitution does not change with increasing quenching rate (wheel speed). However, rapid solidification has a significant effect on the microstructure of the Al-10 Sb alloy. The microstructure of the melt-spun Al-10 Sb alloy dominantly comprises equiaxed primary AlSb dendrites and nanoscale α-Al/AlSb eutectic, different from that of the ingot-cast alloy consisting of coarse primary AlSb plates within the α-Al/AlSb eutectic matrix. Some epitaxial orientation relationships were found between AlSb particles and α-Al matrix in the melt-spun Al-10 Sb alloy as follows: α-Al [310] parallel AlSb [110] and α-Al (002) parallel AlSb (22-bar 0)

  3. Spontaneous Appendicocutaneous Fistula I

    African Journals Online (AJOL)

    M T0k0de* MB, BS and. Dr 0. A. AWOj0bi+ FMCS (Nig). ABSTRACT. Ruptured appendicitis is not a common cause of spontaneous enterocutaneous fistula. A case of ruptured retrocaecal appendicitis presenting as an enterocutaneous fistula in a Nigerian woman is presented. The literature on this disorder is also reviewed.

  4. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Strauss, Edna; Caly, Wanda Regina

    2003-01-01

    Spontaneous bacterial peritonitis occurs in 30% of patients with ascites due to cirrhosis leading to high morbidity and mortality rates. The pathogenesis of spontaneous bacterial peritonitis is related to altered host defenses observed in end-stage liver disease, overgrowth of microorganisms, and bacterial translocation from the intestinal lumen to mesenteric lymph nodes. Clinical manifestations vary from severe to slight or absent, demanding analysis of the ascitic fluid. The diagnosis is confirmed by a number of neutrophils over 250/mm3 associated or not to bacterial growth in culture of an ascites sample. Enterobacteriae prevail and Escherichia coli has been the most frequent bacterium reported. Mortality rates decreased markedly in the last two decades due to early diagnosis and prompt antibiotic treatment. Third generation intravenous cephalosporins are effective in 70% to 95% of the cases. Recurrence of spontaneous bacterial peritonitis is common and can be prevented by the continuous use of oral norfloxacin. The development of bacterial resistance demands the search for new options in the prophylaxis of spontaneous bacterial peritonitis; probiotics are a promising new approach, but deserve further evaluation. Short-term antibiotic prophylaxis is recommended for patients with cirrhosis and ascites shortly after an acute episode of gastrointestinal bleeding.

  5. Spontaneous Grammar Explanations.

    Science.gov (United States)

    Tjoo, Hong Sing; Lewis, Marilyn

    1998-01-01

    Describes one New Zealand university language teacher's reflection on her own grammar explanations to university-level students of Bahasa Indonesian. Examines form-focused instruction through the teacher's spontaneous answers to students' questions about the form of the language they are studying. The teacher's experiences show that it takes time…

  6. EDITORIAL SPONTANEOUS BACTERIAL PERITONITIS ...

    African Journals Online (AJOL)

    hi-tech

    Spontaneous bacterial peritonitis (SBP) frequent]y occurs in patients with liver cirrhosis and ascites. It is defined as an infection of previously sterile ascitic fluid without any demonstrable intrabdominal source of infection. It is now internationally agreed that a polymorphonuclear (PMN) cell count in the ascitic fluid of over 250 ...

  7. Spontaneous dimensional reduction?

    Science.gov (United States)

    Carlip, Steven

    2012-10-01

    Over the past few years, evidence has begun to accumulate suggesting that spacetime may undergo a "spontaneous dimensional reduction" to two dimensions near the Planck scale. I review some of this evidence, and discuss the (still very speculative) proposal that the underlying mechanism may be related to short-distance focusing of light rays by quantum fluctuations.

  8. High current density Esaki tunnel diodes based on GaSb-InAsSb heterostructure nanowires.

    Science.gov (United States)

    Ganjipour, Bahram; Dey, Anil W; Borg, B Mattias; Ek, Martin; Pistol, Mats-Erik; Dick, Kimberly A; Wernersson, Lars-Erik; Thelander, Claes

    2011-10-12

    We present electrical characterization of broken gap GaSb-InAsSb nanowire heterojunctions. Esaki diode characteristics with maximum reverse current of 1750 kA/cm(2) at 0.50 V, maximum peak current of 67 kA/cm(2) at 0.11 V, and peak-to-valley ratio (PVR) of 2.1 are obtained at room temperature. The reverse current density is comparable to that of state-of-the-art tunnel diodes based on heavily doped p-n junctions. However, the GaSb-InAsSb diodes investigated in this work do not rely on heavy doping, which permits studies of transport mechanisms in simple transistor structures processed with high-κ gate dielectrics and top-gates. Such processing results in devices with improved PVR (3.5) and stability of the electrical properties.

  9. Short wavelength infrared InAs/InSb/AlSb type-II superlattice photodetector

    Science.gov (United States)

    Cohen-Elias, D.; Uliel, Y.; Klin, O.; Snapi, N.; Weiss, E.; Shafir, I.; Westreich, O.; Katz, M.

    2017-08-01

    A photodetector based on InAs/InSb/AlSb type-II superlattice (T2SL) with thicknesses of 15, 1 and 4 monolayers respectively, was fabricated and characterized. The interface between InAs and AlAs of one InSb monolayer, increases the λcutoff to 3.3 μm, and improves the InAs/AlSb layer correlation and strain balancing. With a -0.5 V bias, the dark current at 300 and 200 K was 1.1 and 8.5 × 10-3 A/cm2 respectively, and the quantum efficiency at λ = 2.75 μm, for both 300 K and 200 K, was 34%. The detectivity was above 109 cm-Hz1/2/W for 300 K and above 1010 cm-Hz1/2/W for 200 K between 2.5 and 3 μm wavelength.

  10. Electroluminescence in p-InAs/AlSb/InAsSb/AlSb/p(n)-GaSb type II heterostructures with deep quantum wells at the interface

    Czech Academy of Sciences Publication Activity Database

    Mikhailova, M. P.; Ivanov, E.V.; Moiseev, K. D.; Yakovlev, Yu. P.; Hulicius, Eduard; Hospodková, Alice; Pangrác, Jiří; Šimeček, Tomislav

    2010-01-01

    Roč. 44, č. 1 (2010), 66-71 ISSN 1063-7826 Institutional research plan: CEZ:AV0Z10100521 Keywords : electroluninescence * MOVPE * GaSb * InAs * quantum well Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.603, year: 2010

  11. Does the supplementary motor area keep patients with Ondine's curse syndrome breathing while awake?

    Directory of Open Access Journals (Sweden)

    Lysandre Tremoureux

    Full Text Available BACKGROUND: Congenital central hypoventilation syndrome (CCHS is a rare neuro-respiratory disorder associated with mutations of the PHOX2B gene. Patients with this disease experience severe hypoventilation during sleep and are consequently ventilator-dependent. However, they breathe almost normally while awake, indicating the existence of cortical mechanisms compensating for the deficient brainstem generation of automatic breathing. Current evidence indicates that the supplementary motor area plays an important role in modulating ventilation in awake normal humans. We hypothesized that the wake-related maintenance of spontaneous breathing in patients with CCHS could involve supplementary motor area. METHODS: We studied 7 CCHS patients (5 women; age: 20-30; BMI: 22.1 ± 4 kg.m(-2 during resting breathing and during exposure to carbon dioxide and inspiratory mechanical constraints. They were compared with 8 healthy individuals. Segments of electroencephalographic tracings were selected according to ventilatory flow signal, from 2.5 seconds to 1.5 seconds after the onset of inspiration. After artefact rejection, 80 or more such segments were ensemble averaged. A slow upward shift of the EEG signal starting between 2 and 0.5 s before inspiration (pre-inspiratory potential was considered suggestive of supplementary motor area activation. RESULTS: In the control group, pre-inspiratory potentials were generally absent during resting breathing and carbon dioxide stimulation, and consistently identified in the presence of inspiratory constraints (expected. In CCHS patients, pre-inspiratory potentials were systematically identified in all study conditions, including resting breathing. They were therefore significantly more frequent than in controls. CONCLUSIONS: This study provides a neurophysiological substrate to the wakefulness drive to breathe that is characteristic of CCHS and suggests that the supplementary motor area contributes to this phenomenon

  12. Does the supplementary motor area keep patients with Ondine's curse syndrome breathing while awake?

    Science.gov (United States)

    Tremoureux, Lysandre; Raux, Mathieu; Hudson, Anna L; Ranohavimparany, Anja; Straus, Christian; Similowski, Thomas

    2014-01-01

    Congenital central hypoventilation syndrome (CCHS) is a rare neuro-respiratory disorder associated with mutations of the PHOX2B gene. Patients with this disease experience severe hypoventilation during sleep and are consequently ventilator-dependent. However, they breathe almost normally while awake, indicating the existence of cortical mechanisms compensating for the deficient brainstem generation of automatic breathing. Current evidence indicates that the supplementary motor area plays an important role in modulating ventilation in awake normal humans. We hypothesized that the wake-related maintenance of spontaneous breathing in patients with CCHS could involve supplementary motor area. We studied 7 CCHS patients (5 women; age: 20-30; BMI: 22.1 ± 4 kg.m(-2)) during resting breathing and during exposure to carbon dioxide and inspiratory mechanical constraints. They were compared with 8 healthy individuals. Segments of electroencephalographic tracings were selected according to ventilatory flow signal, from 2.5 seconds to 1.5 seconds after the onset of inspiration. After artefact rejection, 80 or more such segments were ensemble averaged. A slow upward shift of the EEG signal starting between 2 and 0.5 s before inspiration (pre-inspiratory potential) was considered suggestive of supplementary motor area activation. In the control group, pre-inspiratory potentials were generally absent during resting breathing and carbon dioxide stimulation, and consistently identified in the presence of inspiratory constraints (expected). In CCHS patients, pre-inspiratory potentials were systematically identified in all study conditions, including resting breathing. They were therefore significantly more frequent than in controls. This study provides a neurophysiological substrate to the wakefulness drive to breathe that is characteristic of CCHS and suggests that the supplementary motor area contributes to this phenomenon. Whether or not this "cortical breathing" can be taken

  13. Can iron plaque affect Sb(III) and Sb(V) uptake by plants under hydroponic conditions

    NARCIS (Netherlands)

    Ji, Ying; Lenz, Markus; Lenz, Markus; Schulin, Rainer; Tandy, Susan

    2018-01-01

    Antimony (Sb) contamination of soils is of concern due to h uman activities such as recycling of Sb containing Pb acid batteries, shooting and mining. However Sb uptake by plants is poorly documented, especially when plants are growing on waterlogged soils and iron plaques form on their roots. The

  14. Determination of traces of Sb(III) using ASV in Sb-rich water samples affected by mining

    Energy Technology Data Exchange (ETDEWEB)

    Cidu, Rosa, E-mail: cidur@unica.it; Biddau, Riccardo; Dore, Elisabetta

    2015-01-07

    Highlights: • Antimony speciation affects the toxicity of this element. • A simple method for Sb(III) analyses in Sb-rich waters was developed. • Sb(III) was determined by ASV in water stabilized with tartaric and nitric acids. • Pre-concentration and/or separation of Sb(III) prior to analysis are not required. - Abstract: Chemical speciation [Sb(V) and Sb(III)] affects the mobility, bioavailability and toxicity of antimony. In oxygenated environments Sb(V) dominates whereas thermodynamically unstable Sb(III) may occur. In this study, a simple method for the determination of Sb(III) in non acidic, oxygenated water contaminated with antimony is proposed. The determination of Sb(III) was performed by anodic stripping voltammetry (ASV, 1–20 μg L{sup −1} working range), the total antimony, Sb(tot), was determined either by inductively coupled plasma mass spectrometry (ICP-MS, 1–100 μg L{sup −1} working range) or inductively coupled plasma optical emission spectrometry (ICP-OES, 100–10,000 μg L{sup −1} working range) depending on concentration. Water samples were filtered on site through 0.45 μm pore size filters. The aliquot for determination of Sb(tot) was acidified with 1% (v/v) HNO{sub 3}. Different preservatives, namely HCl, L(+) ascorbic acid or L(+) tartaric acid plus HNO{sub 3}, were used to assess the stability of Sb(III) in synthetic solutions. The method was tested on groundwater and surface water draining the abandoned mine of Su Suergiu (Sardinia, Italy), an area heavily contaminated with Sb. The waters interacting with Sb-rich mining residues were non acidic, oxygenated, and showed extreme concentrations of Sb(tot) (up to 13,000 μg L{sup −1}), with Sb(III) <10% of total antimony. The stabilization with L(+) tartaric acid plus HNO{sub 3} appears useful for the determination of Sb(III) in oxygenated, Sb-rich waters. Due to the instability of Sb(III), analyses should be carried out within 7 days upon the water collection. The main

  15. Lower lattice thermal conductivity in SbAs than As or Sb monolayers: a first-principles study.

    Science.gov (United States)

    Guo, San-Dong; Liu, Jiang-Tao

    2017-12-06

    Phonon transport in group-VA element (As, Sb and Bi) monolayer semiconductors has been widely investigated in theory, and, of them, monolayer Sb (antimonene) has recently been synthesized. In this work, phonon transport in monolayer SbAs is investigated with a combination of first-principles calculations and the linearized phonon Boltzmann equation. It is found that the lattice thermal conductivity of monolayer SbAs is lower than those of both monolayer As and Sb, and the corresponding sheet thermal conductance is 28.8 W K -1 at room temperature. To understand the lower lattice thermal conductivity in monolayer SbAs than those in monolayer As and Sb, the group velocities and phonon lifetimes of monolayer As, SbAs and Sb are calculated. The calculated results show that the group velocities of monolayer SbAs are between those of monolayer As and Sb, but that the phonon lifetimes of SbAs are smaller than those of both monolayer As and Sb. Hence, the low lattice thermal conductivity in monolayer SbAs is attributed to very small phonon lifetimes. Unexpectedly, the ZA branch has very little contribution to the total thermal conductivity, only 2.4%, which is obviously different from those of monolayer As and Sb with very large contributions. This can be explained by very small phonon lifetimes for the ZA branch of monolayer SbAs. The lower lattice thermal conductivity of monolayer SbAs compared to that of monolayer As or Sb can be understood by the alloying of As (Sb) with Sb (As), which should introduce phonon point defect scattering. We also consider the isotope and size effects on the lattice thermal conductivity. It is found that isotope scattering produces a neglectful effect, and the lattice thermal conductivity with a characteristic length smaller than 30 nm can reach a decrease of about 47%. These results may offer perspectives on tuning the lattice thermal conductivity by the mixture of multiple elements for applications of thermal management and

  16. Liquidus Projection and Isothermal Section of the Sb-Se-Sn System

    Science.gov (United States)

    Chang, Jui-shen; Chen, Sinn-wen

    2017-12-01

    Sb-Se-Sn ternary alloys are promising chalcogenide materials. The liquidus projection and 673.2 K (400 °C) isothermal section of the Sb-Se-Sn ternary system are determined. Numerous Sb-Se-Sn alloys are prepared, and their primary solidification phases are examined. In addition to the three terminal phases, (Sb), (Se) and (Sn), there are Sb2Sn3, SbSn, SnSe, SnSe2, Sb2Se3, Sn2Sb9Se9, and SnSb2Se4 phases. In addition, there are two miscibility gaps along the Sb-Se and Se-Sn and sides. There are ten invariant reactions in the Sb-Se-Sn ternary system, and seven of them are experimentally determined in this study. The lowest reaction temperature of determined invariant reaction is L + SbSn = (Sn) + SnSe at 515.4 K ± 5 K (242.2 °C ± 5 °C). There are nine tie-triangles, which are Liquid + SbSn + SnSe, SbSn + SnSe + (Sb), SnSe + (Sb) + Sn2Sb9Se9, (Sb) + Sb2Se3 + Sn2Sb9Se9, SnSe + Sn2Sb9Se9 + SnSb2Se4, Sb2Se3 + Sn2Sb9Se9 + SnSb2Se4, SnSe + SnSe2 + SnSb2Se4, SnSe2 + SnSb2Se4 + Sb2Se3, and SnSe2 + Sb2Se3 + Liquid in the 673.2 K (400 °C) isothermal section of the Sb-Se-Sn ternary system.

  17. Analysis of Exhaled Breath for Disease Detection

    Science.gov (United States)

    Amann, Anton; Miekisch, Wolfram; Schubert, Jochen; Buszewski, Bogusław; Ligor, Tomasz; Jezierski, Tadeusz; Pleil, Joachim; Risby, Terence

    2014-06-01

    Breath analysis is a young field of research with great clinical potential. As a result of this interest, researchers have developed new analytical techniques that permit real-time analysis of exhaled breath with breath-to-breath resolution in addition to the conventional central laboratory methods using gas chromatography-mass spectrometry. Breath tests are based on endogenously produced volatiles, metabolites of ingested precursors, metabolites produced by bacteria in the gut or the airways, or volatiles appearing after environmental exposure. The composition of exhaled breath may contain valuable information for patients presenting with asthma, renal and liver diseases, lung cancer, chronic obstructive pulmonary disease, inflammatory lung disease, or metabolic disorders. In addition, oxidative stress status may be monitored via volatile products of lipid peroxidation. Measurement of enzyme activity provides phenotypic information important in personalized medicine, whereas breath measurements provide insight into perturbations of the human exposome and can be interpreted as preclinical signals of adverse outcome pathways.

  18. Spontaneous healing of spontaneous coronary artery dissection.

    Science.gov (United States)

    Almafragi, Amar; Convens, Carl; Heuvel, Paul Van Den

    2010-01-01

    Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome and sudden cardiac death. It should be suspected in every healthy young woman without cardiac risk factors, especially during the peripartum or postpartum periods. It is important to check for a history of drug abuse, collagen vascular disease or blunt trauma of the chest. Coronary angiography is essential for diagnosis and early management. We wonder whether thrombolysis might aggravate coronary dissection. All types of treatment (medical therapy, percutaneous intervention or surgery) improve the prognosis without affecting survival times if used appropriately according to the clinical stability and the angiographic features of the involved coronary arteries. Prompt recognition and targeted treatment improve outcomes. We report a case of SCAD in a young female free of traditional cardiovascular risk factors, who presented six hours after thrombolysis for ST elevation myocardial infarction. Coronary angiography showed a dissection of the left anterior descending and immediate branch. She had successful coronary artery bypass grafting, with complete healing of left anterior descending dissection.

  19. Bismuth distribution in InSb/Bi epitaxial layers

    International Nuclear Information System (INIS)

    Lantsov, A.F.; Akchurin, R.Kh.; Zinov'ev, V.G.

    1981-01-01

    Bismuth distribution in epitaxial layers of InSb/Bi, prepared by liquid-phase epitaxy (LPE) on InSb sublayers, is studied. The solution-melt, crystallization is carried out from the compositions corresponded to the cross sections InSb-Bi, InSb-InBi and InSb-In 2 Bi of ternary system In-Sb-Bi and changed in the limits, determined by the state diagram liquidus in the temperature range from 220 to 450 deg C. The temperature dependence of the coefficients of bismuth distribution in epitaxial layers of InSb(Bi) is specified. The dependence of bismuth concentration on the composition of initial liquid phase is established [ru

  20. Spontaneous spinal epidural abscess.

    LENUS (Irish Health Repository)

    Ellanti, P

    2011-10-01

    Spinal epidural abscess is an uncommon entity, the frequency of which is increasing. They occur spontaneously or as a complication of intervention. The classical triad of fever, back pain and neurological symptoms are not always present. High index of suspicion is key to diagnosis. Any delay in diagnosis and treatment can have significant neurological consequences. We present the case of a previously well man with a one month history of back pain resulting from an epidural abscess.

  1. In As{sub 1–x}Sb{sub x} heteroepitaxial structures on compositionally graded GaInSb and AlGaInSb buffer layers

    Energy Technology Data Exchange (ETDEWEB)

    Guseynov, R. R.; Tanriverdiyev, V. A. [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan); Kipshidze, G., E-mail: gela.kishidze@stonybrook.ede [Stony Brook, Stony Brook University (United States); Aliyeva, Ye. N.; Aliguliyeva, Kh. V.; Abdullayev, N. A., E-mail: abnadir@mail.ru; Mamedov, N. T. [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan)

    2017-04-15

    Unrelaxed InAs{sub 1–x}Sb{sub x} (x = 0.43 and 0.38) alloy layers are produced by molecular-beam epitaxy on compositionally graded GaInSb and AlGaInSb buffer layers. The high quality of the thin films produced is confirmed by the results of high-resolution X-ray diffraction analysis and micro-Raman studies. The twomode type of transformation of the phonon spectra of InAs{sub 1–x}Sb{sub x} alloys is established.

  2. [Stahl, Leibniz, Hoffmann and breathing].

    Science.gov (United States)

    Carvallo, Sarah

    2006-01-01

    At the beginning of the XVIII th century, Wilhelm Gottfried Leibniz and Friedrich Hoffmann criticize Georg Ernst Stahl's medical theory. They differenciate between unsound and true reasonings. Namely, they validate Stahl's definition of breath but extracting it from its animist basis and placing it in an epistemology obeying to the principle of sufficient reason and to the mechanical model. The stahlian discovery consists in understanding breath as a calorific ventilation against the ancient conception; the iatromechanists recognize its accuracy, but they try then to transpose it to a mechanical model of ventilation. Using it in a different epistemological context implies that they analyze the idea of discovery "true" in its contents, but "wrong" in its hypothesis. It impels to examine the epistemology of medical knowledge, as science and therapeutics, and in its links with the other scientific theories. Thus, if Leibniz as philosopher and Hoffmann as doctor consider Stahl's animism so important, it is because its discoveries question the fundamental principles of medicine.

  3. TR-BREATH: Time-Reversal Breathing Rate Estimation and Detection.

    Science.gov (United States)

    Chen, Chen; Han, Yi; Chen, Yan; Lai, Hung-Quoc; Zhang, Feng; Wang, Beibei; Liu, K J Ray

    2018-03-01

    In this paper, we introduce TR-BREATH, a time-reversal (TR)-based contact-free breathing monitoring system. It is capable of breathing detection and multiperson breathing rate estimation within a short period of time using off-the-shelf WiFi devices. The proposed system exploits the channel state information (CSI) to capture the miniature variations in the environment caused by breathing. To magnify the CSI variations, TR-BREATH projects CSIs into the TR resonating strength (TRRS) feature space and analyzes the TRRS by the Root-MUSIC and affinity propagation algorithms. Extensive experiment results indoor demonstrate a perfect detection rate of breathing. With only 10 s of measurement, a mean accuracy of can be obtained for single-person breathing rate estimation under the non-line-of-sight (NLOS) scenario. Furthermore, it achieves a mean accuracy of in breathing rate estimation for a dozen people under the line-of-sight scenario and a mean accuracy of in breathing rate estimation of nine people under the NLOS scenario, both with 63 s of measurement. Moreover, TR-BREATH can estimate the number of people with an error around 1. We also demonstrate that TR-BREATH is robust against packet loss and motions. With the prevailing of WiFi, TR-BREATH can be applied for in-home and real-time breathing monitoring.

  4. Antimony Redox Biotransformation in the Subsurface: Effect of Indigenous Sb(V) Respiring Microbiota.

    Science.gov (United States)

    Wang, Liying; Ye, Li; Yu, Yaqin; Jing, Chuanyong

    2018-02-06

    Anaerobic microbiological antimonate [Sb(V)] respiration is a newly discovered process regulating the Sb redox transformation in soils. However, little is known about the role microbiological Sb(V) respiration plays in the fate of Sb in the subsurface, especially in the presence of sulfate and electron shuttles. Herein, we successfully enriched a Sb(V) reducing microbiota (SbRM) from the subsurface near an active Sb mine. SbRM was dominated by genus Alkaliphilus (18-36%), Clostridiaceae (17-18%), Tissierella (24-27%), and Lysinibacillus (16-37%). The incubation results showed that SbRM reduced 88% of dissolved Sb(V) to Sb(III), but the total Sb mobility remained the same as in the abiotic control, indicating that SbRM alone did not increase the total Sb release but regulated the Sb speciation in the subsurface. Micro X-ray fluorescence (μ-XRF) analysis suggested the association of Sb and Fe, and electron shuttles such as anthraquinone-2,6-disulfonic disodium salt (AQDS) markedly enhanced the Sb release due to its ability to facilitate Fe mineral dissolution. Sb L-edge and S K-edge X-ray absorption near edge structure (XANES) results demonstrated that indigenous SbRM immobilized Sb via Sb 2 S 3 formation, especially in a sulfur-rich environment. The insights gained from this study shed new light on Sb mobilization and its risk assessment in the subsurface environment.

  5. Thoracic radiotherapy and breath control: current prospects

    International Nuclear Information System (INIS)

    Reboul, F.; Mineur, L.; Paoli, J.B.; Bodez, V.; Oozeer, R.; Garcia, R.

    2002-01-01

    Three-dimensional conformal radiotherapy (3D CRT) is adversely affected by setup error and organ motion. In thoracic 3D CRT, breathing accounts for most of intra-fraction movements, thus impairing treatment quality. Breath control clearly exhibits dosimetric improvement compared to free breathing, leading to various techniques for gated treatments. We review benefits of different breath control methods -i.e. breath-holding or beam gating, with spirometric, isometric or X-ray respiration sensor- and argument the choice of expiration versus inspiration, with consideration to dosimetric concerns. All steps of 3D-CRT can be improved with breath control. Contouring of organs at risk (OAR) and target are easier and more accurate on breath controlled CT-scans. Inter- and intra-fraction target immobilisation allows smaller margins with better coverage. Lung outcome predictors (NTCP, Mean Dose, LV20, LV30) are improved with breath-control. In addition, inspiration breath control facilitates beam arrangement since it widens the distance between OAR and target, and leaves less lung normal tissue within the high dose region. Last, lung density, as of CT scan, is more accurate, improving dosimetry. Our institutions choice is to use spirometry driven, patient controlled high-inspiration breath-hold; this technique gives excellent immobilization results, with high reproducibility, yet it is easy to implement and costs little extra treatment time. Breath control, whatever technique is employed, proves superior to free breathing treatment when using 3D-CRT. Breath control should then be used whenever possible, and is probably mandatory for IMRT. (authors)

  6. Hole-dominated transport in InSb nanowires grown on high-quality InSb films

    Energy Technology Data Exchange (ETDEWEB)

    Algarni, Zaina; George, David; Singh, Abhay; Lin, Yuankun; Philipose, U., E-mail: usha.philipose@unt.edu [University of North Texas, Department of Physics (United States)

    2016-12-15

    We have developed an effective strategy for synthesizing p-type indium antimonide (InSb) nanowires on a thin film of InSb grown on glass substrate. The InSb films were grown by a chemical reaction between Sb{sub 2}S{sub 3} and In and were characterized by structural, compositional, and optical studies. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies reveal that the surface of the substrate is covered with a polycrystalline InSb film comprised of sub-micron sized InSb islands. Energy dispersive X-ray (EDX) results show that the film is stoichiometric InSb. The optical constants of the InSb film, characterized using a variable-angle spectroscopic ellipsometer (VASE) shows a maximum value for refractive index at 3.7 near 1.8 eV, and the extinction coefficient (k) shows a maximum value 3.3 near 4.1 eV. InSb nanowires were subsequently grown on the InSb film with 20 nm sized Au nanoparticles functioning as the metal catalyst initiating nanowire growth. The InSb nanowires with diameters in the range of 40–60 nm exhibit good crystallinity and were found to be rich in Sb. High concentrations of anions in binary semiconductors are known to introduce acceptor levels within the band gap. This un-intentional doping of the InSb nanowire resulting in hole-dominated transport in the nanowires is demonstrated by the fabrication of a p-channel nanowire field effect transistor. The hole concentration and field effect mobility are estimated to be ≈1.3 × 10{sup 17} cm{sup −3} and 1000 cm{sup 2} V{sup −1} s{sup −1}, respectively, at room temperature, values that are particularly attractive for the technological implications of utilizing p-InSb nanowires in CMOS electronics.

  7. Synthesis and thermoelectric properties of Sb{sub 0.20}CoSb{sub 2.80} skutterudite

    Energy Technology Data Exchange (ETDEWEB)

    Figueirêdo, C.A., E-mail: camila_fig@hotmail.com [Universidade Federal do Rio Grande do Sul, PGCIMAT, Instituto de Física, 91501-970 Porto Alegre, RS (Brazil); Gallas, M.R. [Universidade Federal do Rio Grande do Sul, PGCIMAT, Instituto de Física, 91501-970 Porto Alegre, RS (Brazil); Institute for Multiscale Simulations, Friedrich-Alexander-Universität, Nägelsbachstrasse 49b, 91052 Erlangen (Germany); Zorzi, J.E. [Universidade de Caxias do Sul, Instituto de Materiais Cerâmicos, 95765-000 Bom Princípio, RS (Brazil); Perottoni, C.A. [Universidade Federal do Rio Grande do Sul, PGCIMAT, Instituto de Física, 91501-970 Porto Alegre, RS (Brazil); Universidade de Caxias do Sul, Instituto de Materiais Cerâmicos, 95765-000 Bom Princípio, RS (Brazil)

    2014-06-15

    Highlights: • A HP-HT Sb{sub 0.20}CoSb{sub 2.80} phase was prepared by processing cobalt antimonide at 7.7 GPa and 550 °C, for (at least) 5 min. • The mechanism of formation of this phase involves (i) decomposition of cobalt antimonide into CoSb{sub 2} and Sb, and (ii) insertion of Sb into the remaining cobalt antimonide. • The mechanism of formation is qualitatively different from that responsible for the formation of the high pressure (greater than 20 GPa) phase. - Abstract: Polycrystalline samples of cobalt antimonide (CoSb{sub 2.79}) were submitted to different conditions of pressure, temperature and processing time, in a high-pressure toroidal-type chamber, aiming to maximize the production of the high pressure phase previously observed in experiments with a diamond anvil cell. Rietveld refinements of X-ray powder diffraction data were performed to determine the phase composition and structural parameters. The maximum yield, 89(2) wt.% of Sb{sub x}CoSb{sub 3−x} phase, was obtained at 7.7 GPa, 550 °C and (at least) 5 min of processing time. The mechanism behind the formation of Sb{sub x}CoSb{sub 3−x} at high pressure and high temperature is actually not the same as that previously inferred from experiments at higher pressures (20 GPa) and room temperature with the diamond anvil cell. Indeed, evidences suggest that, at high pressure and high temperature, Sb{sub x}CoSb{sub 3−x} is formed by insertion of Sb resulting from decomposition of cobalt antimonide. Thermal conductivity, Seebeck coefficient and electrical conductivity were estimated for CoSb{sub 2.79} and Sb{sub 0.20}CoSb{sub 2.80}. The thermoelectric figure of merit at room temperature for Sb{sub 0.20}CoSb{sub 2.80} resulted 33% greater than that for CoSb{sub 2.79}.

  8. Change of central hemodynamics of qualified athletes for testing the use of controlled breathing and evaluation

    Directory of Open Access Journals (Sweden)

    A.P. Romanchuk

    2013-11-01

    Full Text Available Using spiroarteriocardiorhythmography surveyed 174 qualified athletes (121 male and 53 female. The examination consisted of three consecutive two-minute registrations - spontaneous, controlled breathing 6 and 15 breaths per minute. Found that the hemodynamic change substantially when the respiratory tests in the first place, cardiac output, cardiac index, total peripheral vascular resistance and specific peripheral vascular resistance. To develop criteria for evaluation of hemodynamic changes carried percentile variance analysis of all indicators in the performance tests. Testing of the evaluation criteria for different types of hemodynamics in athletes allowed to establish that eukinetic type characteristic is the reduction in heart rate and pulse blood pressure under test with controlled breathing 6 times per minute for hypokinetic – pronounced increase in systolic blood pressure and pulse blood pressure during the breath tests 6 and 15 times per minute for hyperkinetic – reducing end-diastolic volume, end-systolic volume, stroke volume, in vivo performance of both tests and an increase in systemic vascular resistance during test 15 breaths per minute.

  9. Masticatory Changes in Oral Breath Secondary to Allergic Rhinitis: Integrative Review

    Directory of Open Access Journals (Sweden)

    Bezerra, Luciana Ângelo

    2014-04-01

    Full Text Available Introduction The III Brazilian Consensus on Rhinitis (2012 defines allergic rhinitis as a nasal mucosa inflammation, mediated by immunoglobulin E, after exposure to allergens. The classic signs and symptoms of allergic rhinitis are nasal obstruction, watery rhinorrhea, sneezing, and nasal itching, often reversible either spontaneously or with treatment, and mouth breathing (breathing predominantly through the mouth, regardless of the cause, due to a nasal breathing impairment in some cases. Objective To evaluate the literature on masticatory changes in children with mouth breathing due to allergic rhinitis. Methods We conducted a search of the past 10 years, at Bireme and MEDLINE databases, for articles that covered masticatory changes in children with mouth breathing secondary to allergic rhinitis. Results We found 1,986 articles, including 15 repeated in databases, but only two articles met the inclusion criteria fully. Discussion We found few studies to answer the question raised in this review, and those studies have some methodological limitations. Most articles claimed no have statistically significant differences in masticatory changes in this population. Conclusion A better controlled study (isolating diseases, exposure time, with a larger sample (sample calculation appropriate, would be necessary to examine such changes.

  10. GaAs/GaSb nanowire heterostructures grown by MOVPE

    DEFF Research Database (Denmark)

    Jeppsson, Mattias; Dick, Kimberly A.; Wagner, Jakob Birkedal

    2008-01-01

    We report Au-assisted growth of GaAs/GaSb nanowire heterostructures on GaAs(1 1 1)B-substrates by metal-organic vapor phase epitaxy. The growth is studied at various precursor molar fractions and temperatures, in order to optimize the growth conditions for the GaSb nanowire segment. In contrast...... to most other III–V nanowire systems, the GaSb nanowire growth is Group V-limited under most conditions. We found that depending on the TMSb molar fraction, the seed particle is either supersaturated AuGa or AuGa2 during GaSb growth. The high Ga content in the particle gives a characteristic diameter...... increase between the GaAs and GaSb segment. From TEM and XEDS measurements we conclude that the GaSb nanowire growth occurs along either the AuGa–GaSb or AuGa2–GaSb pseudo-binaries of the Au–Ga–Sb ternary phase diagram. Finally, the GaSb nanowires exhibit untapered radial growth on the {1 1¯ 0} side facets....

  11. Microbiological reduction of Sb(V) in anoxic freshwater sediments

    Science.gov (United States)

    Oremland, Ronald S.; Kulp, Thomas R.; Miller, Laurence G.; Braiotta, Franco; Webb, Samuel M.; Kocar, Benjamin D; Blum, Jodi S.

    2014-01-01

    Microbiological reduction of millimolar concentrations of Sb(V) to Sb(III) was observed in anoxic sediments from two freshwater settings: (1) a Sb- and As-contaminated mine site (Stibnite Mine) in central Idaho and 2) an uncontaminated suburban lake (Searsville Lake) in the San Francisco Bay Area. Rates of Sb(V) reduction in anoxic sediment microcosms and enrichment cultures were enhanced by amendment with lactate or acetate as electron donors but not by H2, and no reduction occurred in sterilized controls. Addition of 2-14C-acetate to Stibnite Mine microcosms resulted in the production of 14CO2 coupled to Sb(V) reduction, suggesting that this process proceeds by a dissimilatory respiratory pathway in those sediments. Antimony(V) reduction in Searsville Lake sediments was not coupled to acetate mineralization and may be associated with Sb-resistance. The microcosms and enrichment cultures also reduced sulfate, and the precipitation of insoluble Sb(III)-sulfide complexes was a major sink for reduced Sb. The reduction of Sb(V) by Stibnite Mine sediments was inhibited by As(V), suggesting that As(V) is a preferred electron acceptor for the indigenous community. These findings indicate a novel pathway for anaerobic microbiological respiration and suggest that communities capable of reducing high concentrations of Sb(V) commonly occur naturally in the environment.

  12. Kidney motion during free breathing and breath hold for MR-guided radiotherapy

    Science.gov (United States)

    Stam, Mette K.; van Vulpen, Marco; Barendrecht, Maurits M.; Zonnenberg, Bernard A.; Intven, Martijn; Crijns, Sjoerd P. M.; Lagendijk, Jan J. W.; Raaymakers, Bas W.

    2013-04-01

    Current treatments for renal cell carcinoma have a high complication rate due to the invasiveness of the treatment. With the MRI-linac it may be possible to treat renal tumours non-invasively with high-precision radiotherapy. This is expected to reduce complications. To deliver a static dose distribution, radiation gating will be used. In this study the reproducibility and efficiency of free breathing gating and a breath hold treatment of the kidney was investigated. For 15 patients with a renal lesion the kidney motion during 2 min of free breathing and 10 consecutive expiration breath holds was studied with 2D cine MRI. The variability in kidney expiration position and treatment efficiency for gating windows of 1 to 20 mm was measured for both breathing patterns. Additionally the time trend in free breathing and the variation in expiration breath hold kidney position with baseline shift correction was determined. In 80% of the patients the variation in expiration position during free breathing is smaller than 2 mm. No clinically relevant time trends were detected. The variation in expiration breath hold is for all patients larger than the free breathing expiration variation. Gating on free breathing is, for gating windows of 1 to 5 mm more efficient than breath hold without baseline correction. When applying a baseline correction to the breath hold it increases the treatment efficiency. The kidney position is more reproducible in expiration free breathing than non-guided expiration breath hold. For small gating windows it is also more time efficient. Since free breathing also seems more comfortable for the patients it is the preferred breathing pattern for MRI-Linac treatments of the kidney.

  13. Kidney motion during free breathing and breath hold for MR-guided radiotherapy

    International Nuclear Information System (INIS)

    Stam, Mette K; Van Vulpen, Marco; Intven, Martijn; Crijns, Sjoerd P M; Lagendijk, Jan J W; Raaymakers, Bas W; Barendrecht, Maurits M; Zonnenberg, Bernard A

    2013-01-01

    Current treatments for renal cell carcinoma have a high complication rate due to the invasiveness of the treatment. With the MRI-linac it may be possible to treat renal tumours non-invasively with high-precision radiotherapy. This is expected to reduce complications. To deliver a static dose distribution, radiation gating will be used. In this study the reproducibility and efficiency of free breathing gating and a breath hold treatment of the kidney was investigated. For 15 patients with a renal lesion the kidney motion during 2 min of free breathing and 10 consecutive expiration breath holds was studied with 2D cine MRI. The variability in kidney expiration position and treatment efficiency for gating windows of 1 to 20 mm was measured for both breathing patterns. Additionally the time trend in free breathing and the variation in expiration breath hold kidney position with baseline shift correction was determined. In 80% of the patients the variation in expiration position during free breathing is smaller than 2 mm. No clinically relevant time trends were detected. The variation in expiration breath hold is for all patients larger than the free breathing expiration variation. Gating on free breathing is, for gating windows of 1 to 5 mm more efficient than breath hold without baseline correction. When applying a baseline correction to the breath hold it increases the treatment efficiency. The kidney position is more reproducible in expiration free breathing than non-guided expiration breath hold. For small gating windows it is also more time efficient. Since free breathing also seems more comfortable for the patients it is the preferred breathing pattern for MRI-Linac treatments of the kidney. (paper)

  14. GaSb-related materials for TPV cells

    Science.gov (United States)

    Mauk, M. G.; Andreev, V. M.

    2003-05-01

    A survey of materials options and technologies for GaSb-related thermophotovoltaic (TPV) cells is presented, followed by an overview of device design principles and issues. This device technology has been developed for thermal-to-electric generator systems with thermal emitter infrared sources operated in the 1000-1200 °C range. Significant results for the growth, material characterization and device performance of TPV cells based on InGaAsSb, InGaSb, AlGaAsSb and InAsSbP fabricated by LPE, MOCVD, MBE and diffusion methods are reviewed. For single-junction TPV cells, epitaxial heterostructures with a ~0.53 eV bandgap InGaAsSb base layer and wide-bandgap AlGaAsSb or GaSb window/cladding layers (all closely lattice matched to a GaSb substrate) represent the state of the art. As an alternative, a low-cost Zn-diffusion technology for fabrication of InGaAsSb p-n homojunction structures has been developed for producing the high efficiency TPV cells. External quantum yields as high as 90% at wavelengths (around 2000 nm wavelength), and response edges to about 2400 nm wavelength have been obtained with these TPV cells. Multijunction tandem TPV devices based on GaSb top cells and InGaAsSb bottom cells provide even higher performance. TPV cells based on InAsSbP, also reviewed here, have spectral responses in wavelengths in the 2.5-3.5 mum range, and thus provide a means for utilizing radiation from thermal emitters with lower temperatures.

  15. Horses Auto-Recruit Their Lungs by Inspiratory Breath Holding Following Recovery from General Anaesthesia.

    Directory of Open Access Journals (Sweden)

    Martina Mosing

    Full Text Available This study evaluated the breathing pattern and distribution of ventilation in horses prior to and following recovery from general anaesthesia using electrical impedance tomography (EIT. Six horses were anaesthetised for 6 hours in dorsal recumbency. Arterial blood gas and EIT measurements were performed 24 hours before (baseline and 1, 2, 3, 4, 5 and 6 hours after horses stood following anaesthesia. At each time point 4 representative spontaneous breaths were analysed. The percentage of the total breath length during which impedance remained greater than 50% of the maximum inspiratory impedance change (breath holding, the fraction of total tidal ventilation within each of four stacked regions of interest (ROI (distribution of ventilation and the filling time and inflation period of seven ROI evenly distributed over the dorso-ventral height of the lungs were calculated. Mixed effects multi-linear regression and linear regression were used and significance was set at p<0.05. All horses demonstrated inspiratory breath holding until 5 hours after standing. No change from baseline was seen for the distribution of ventilation during inspiration. Filling time and inflation period were more rapid and shorter in ventral and slower and longer in most dorsal ROI compared to baseline, respectively. In a mixed effects multi-linear regression, breath holding was significantly correlated with PaCO2 in both the univariate and multivariate regression. Following recovery from anaesthesia, horses showed inspiratory breath holding during which gas redistributed from ventral into dorsal regions of the lungs. This suggests auto-recruitment of lung tissue which would have been dependent and likely atelectic during anaesthesia.

  16. DWPF Simulant CPC Studies For SB8

    Energy Technology Data Exchange (ETDEWEB)

    Newell, J. D.

    2013-09-25

    Prior to processing a Sludge Batch (SB) in the Defense Waste Processing Facility (DWPF), flowsheet studies using simulants are performed. Typically, the flowsheet studies are conducted based on projected composition(s). The results from the flowsheet testing are used to 1) guide decisions during sludge batch preparation, 2) serve as a preliminary evaluation of potential processing issues, and 3) provide a basis to support the Shielded Cells qualification runs performed at the Savannah River National Laboratory (SRNL). SB8 was initially projected to be a combination of the Tank 40 heel (Sludge Batch 7b), Tank 13, Tank 12, and the Tank 51 heel. In order to accelerate preparation of SB8, the decision was made to delay the oxalate-rich material from Tank 12 to a future sludge batch. SB8 simulant studies without Tank 12 were reported in a separate report.1 The data presented in this report will be useful when processing future sludge batches containing Tank 12. The wash endpoint target for SB8 was set at a significantly higher sodium concentration to allow acceptable glass compositions at the targeted waste loading. Four non-coupled tests were conducted using simulant representing Tank 40 at 110-146% of the Koopman Minimum Acid requirement. Hydrogen was generated during high acid stoichiometry (146% acid) SRAT testing up to 31% of the DWPF hydrogen limit. SME hydrogen generation reached 48% of of the DWPF limit for the high acid run. Two non-coupled tests were conducted using simulant representing Tank 51 at 110-146% of the Koopman Minimum Acid requirement. Hydrogen was generated during high acid stoichiometry SRAT testing up to 16% of the DWPF limit. SME hydrogen generation reached 49% of the DWPF limit for hydrogen in the SME for the high acid run. Simulant processing was successful using previously established antifoam addition strategy. Foaming during formic acid addition was not observed in any of the runs. Nitrite was destroyed in all runs and no N2O was detected

  17. Relationships between hippocampal activity and breathing patterns

    DEFF Research Database (Denmark)

    Harper, R M; Poe, G R; Rector, D M

    1998-01-01

    Single cell discharge, EEG activity, and optical changes accompanying alterations in breathing patterns, as well as the knowledge that respiratory musculature is heavily involved in movement and other behavioral acts, implicate hippocampal regions in some aspects of breathing control. The control...... is unlikely to reside in oscillatory breathing movements, because such patterns emerge in preparations retaining only the medulla (and perhaps only the spinal cord). However, momentary changes in breathing patterns induced by affect, startle, whole-body movement changes, or compensatory ventilatory changes...... of hippocampal contributions to breathing control should be viewed in the context that significant interactions exist between blood pressure changes and ventilation, and that modest breathing challenges, such as exposure to hypercapnia or to increased resistive loads, bring into action a vast array of brain...

  18. Electronic structure and high pressure phase transition in LaSb and CeSb

    International Nuclear Information System (INIS)

    Mathi Jaya, S.; Sanyal, S.P.

    1992-09-01

    The electronic structure and high pressure structural phase transition in cerium and lanthanum antimonides have been investigated using the tight binding LMTO method. The calculation of total energy reveals that the simple tetragonal structure is found to be stable at high pressures for both the compounds. In the case of LaSb, the calculated value of the equilibrium cell volume and the cell volume at which phase transition occurs are found to have a fairly good agreement with the experimental results. However, in the case of CeSb, the agreement is not as good as in LaSb. We also predicted the most favoured c/a value in the high pressure phase (simple tetragonal) for these compounds. Further we present the calculated results on the electronic structure of these systems at the equilibrium as well as at the reduced cell volumes. (author). 8 refs, 11 figs, 1 tab

  19. Optical and structural properties of MOVPE-grown GaInSb/GaSb quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Wagener, Viera, E-mail: viera.wagener@nmmu.ac.z [Physics Department, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa); Olivier, E.J.; Botha, J.R. [Physics Department, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa)

    2009-12-15

    This paper reports on the optical and structural properties of strained type-I Ga{sub 1-x}In{sub x}Sb quantum wells embedded in GaSb from a metal-organic vapour phase epitaxial growth perspective. Photoluminescence measurements and transmission electron microscopy were used to evaluate the effect of the growth temperature on the quality of Ga{sub 1-x}In{sub x}Sb strained layers with varied alloy compositions and thicknesses. Although the various factors contributing to the overall quality of the strained layers are difficult to separate, the quantum well characteristics are significantly altered by the growth temperature. Despite the high growth rates (approx2 nm/s), quantum wells grown at 607 deg. C display photoluminescence emissions with full-width at half-maximum of 3.5-5.0 meV for an indium solid content (x) up to 0.15.

  20. Optical and structural properties of MOVPE-grown GaInSb/GaSb quantum wells

    International Nuclear Information System (INIS)

    Wagener, Viera; Olivier, E.J.; Botha, J.R.

    2009-01-01

    This paper reports on the optical and structural properties of strained type-I Ga 1-x In x Sb quantum wells embedded in GaSb from a metal-organic vapour phase epitaxial growth perspective. Photoluminescence measurements and transmission electron microscopy were used to evaluate the effect of the growth temperature on the quality of Ga 1-x In x Sb strained layers with varied alloy compositions and thicknesses. Although the various factors contributing to the overall quality of the strained layers are difficult to separate, the quantum well characteristics are significantly altered by the growth temperature. Despite the high growth rates (∼2 nm/s), quantum wells grown at 607 deg. C display photoluminescence emissions with full-width at half-maximum of 3.5-5.0 meV for an indium solid content (x) up to 0.15.

  1. (In)GaSb/AlGaSb quantum wells grown on Si substrates

    International Nuclear Information System (INIS)

    Akahane, Kouichi; Yamamoto, Naokatsu; Gozu, Shin-ichiro; Ueta, Akio; Ohtani, Naoki

    2007-01-01

    We have successfully grown GaSb and InGaSb quantum wells (QW) on a Si(001) substrate, and evaluated their optical properties using photoluminescence (PL). The PL emissions from the QWs at room temperature were observed at around 1.55 μm, which is suitable for fiber optic communications systems. The measured ground state energy of each QW matched well with the theoretical value calculated by solving the Schroedinger equation for a finite potential QW. The temperature dependence of the PL intensity showed large activation energy (∼ 77.6 meV) from QW. The results indicated that the fabricated QW structure had a high crystalline quality, and the GaSb QW on Si for optical devices operating at temperatures higher than room temperature will be expected

  2. Magneto-absorption in Narrow Gap InSb/AlInSb Parabolic Quantum Wells

    Science.gov (United States)

    Saha, D.; Sanders, G. D.; Stanton, C. J.; Kasturiarachchi, T.; Gempel, W.; Edirisooriya, M.; Mishima, T. D.; Doezema, R. E.; Santos, M. B.

    2010-03-01

    Because of its narrow gap, InSb has considerable promise as a quantum well material because its small conduction-band mass gives it the highest room temperature electron mobility among the III-V materials. We present experiments and calculations for the magneto-absorption spectra in a strained, narrow gap InSb/AlInSb parabolic quantum well. Our calculations are based on the 8-band Pidgeon-Brown model generalized to include the effects of the parabolic confinement potential as well as pseudomorphic strain. Optical properties are calculated within the golden rule approximation and compared with experiments. The magneto-optical absorption spectrum is calculated for magnetic fields from 1 to 8 T for x-linear, e-active and h-active polarizations. Comparison to experiment allows one to accurately determine the quantum confined, spin-split conduction and valence band energies. Results show a sensitive dependence on the strain at the pseudomorphic interfaces.

  3. Spontaneous Thigh Compartment Syndrome

    Directory of Open Access Journals (Sweden)

    Khan, Sameer K

    2011-02-01

    Full Text Available A young man presented with a painful and swollen thigh, without any history of trauma, illness, coagulopathic medication or recent exertional exercise. Preliminary imaging delineated a haematoma in the anterior thigh, without any fractures or muscle trauma. Emergent fasciotomies were performed. No pathology could be identified intra-operatively, or on follow-up imaging. A review of thigh compartment syndromes described in literature is presented in a table. Emergency physicians and traumatologists should be cognisant of spontaneous atraumatic presentations of thigh compartment syndrome, to ensure prompt referral and definitive management of this limb-threatening condition. [West J Emerg Med. 2011;12(1:134-138].

  4. Nucleosome breathing and remodeling constrain CRISPR-Cas9 function.

    Science.gov (United States)

    Isaac, R Stefan; Jiang, Fuguo; Doudna, Jennifer A; Lim, Wendell A; Narlikar, Geeta J; Almeida, Ricardo

    2016-04-28

    The CRISPR-Cas9 bacterial surveillance system has become a versatile tool for genome editing and gene regulation in eukaryotic cells, yet how CRISPR-Cas9 contends with the barriers presented by eukaryotic chromatin is poorly understood. Here we investigate how the smallest unit of chromatin, a nucleosome, constrains the activity of the CRISPR-Cas9 system. We find that nucleosomes assembled on native DNA sequences are permissive to Cas9 action. However, the accessibility of nucleosomal DNA to Cas9 is variable over several orders of magnitude depending on dynamic properties of the DNA sequence and the distance of the PAM site from the nucleosome dyad. We further find that chromatin remodeling enzymes stimulate Cas9 activity on nucleosomal templates. Our findings imply that the spontaneous breathing of nucleosomal DNA together with the action of chromatin remodelers allow Cas9 to effectively act on chromatin in vivo.

  5. Meigs′ syndrome in an elderly woman with short of breath

    Directory of Open Access Journals (Sweden)

    Wan-Chen Tsai

    2015-01-01

    Full Text Available The Meigs′ syndrome is a rare syndrome defined as the triad of benign solid ovarian tumors, ascites, and pleural effusion, which resolve spontaneously and permanently after tumor resection. Lung collapse due to a large amount of pleural effusion is a common mechanism of death. It always requires surgical treatment. We report an 84-year-old woman with a large ovarian fibroma associated with Meigs′ syndrome and short of breath. It is difficult to diagnose preoperatively and is usually misdiagnosed as an ovarian malignancy. Considering the patient′s serious clinical condition and assuming that she had Meigs′ syndrome with a large ovarian mass and possible lung collapse due to large amount of pleural effusion, we chose the most appropriate surgical treatment after pathologic examination, then enabled definitive diagnosis of the benign tumor and removed the huge ovarian fibroma. This resulted in a timely symptoms resolution, short hospitalization, and relatively low morbidity in elderly.

  6. Removal of Sb(III and Sb(V by Ferric Chloride Coagulation: Implications of Fe Solubility

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Inam

    2018-04-01

    Full Text Available Coagulation and precipitation appear to be the most efficient and economical methods for the removal of antimony from aqueous solution. In this study, antimony removal from synthetic water and Fe solubility with ferric chloride (FC coagulation has been investigated. The effects of pH, FC dosage, initial antimony loading and mixed Sb(III, Sb(V proportions on Fe solubility and antimony removal were studied. The results showed that the Sb(III removal efficiency increased with the increase of solution pH particularly due to an increase in Fe precipitation. The Sb(V removal was influenced by the solution pH due to a change in Fe solubility. However, the Fe solubility was only impaired by the Sb(III species at optimum pH 7. The removal efficiencies of both Sb species were enhanced with an increase in FC dose. The quantitative analysis of the isotherm study revealed the strong adsorption potential of Sb(III on Fe precipitates as compared to Sb(V. Furthermore, the removal behavior of antimony was inhibited in mixed proportion with high Sb(V fraction. In conclusion, this study contributes to better understanding the fate of Sb species, their mobilities, and comparative removal behavior, with implications for Fe solubility using ferric chloride in different aqueous environments.

  7. Voluntary breath-holding duration in healthy subjects with obesity: Role of peripheral chemosensitivity to carbon dioxide.

    Science.gov (United States)

    Trembach, N V; Zabolotskikh, I B

    2018-02-01

    The present study aimed to explore the peripheral chemoreflex sensitivity in healthy subjects with high body mass index (BMI). We studied 26 healthy men with obesity and 23 healthy men without obesity. All participants performed the breath-holding test in the morning, and the single-breath carbon dioxide (SB-CO 2 ) test on the next day. The sensitivity of peripheral chemoreceptors to CO 2 did not differ between two groups (P = .47). In contrast, the duration of breath-holding was significantly lower in participants with elevated BMI (40.6 ± 10.5 s versus 47.2 ± 8.7 s; P < .05). In the multifactor regression model, only differences in waist-to-hip ratio (WHR) and SB-CO 2 remained statistically significant (R 2 for the model = 0.62, P < .001). The sensitivity of peripheral chemoreflex to CO 2 was preserved in healthy men with obesity. The higher sensitivity of peripheral chemoreflex to CO 2 and higher WHR were associated with a decrease in the duration of voluntary apnea in subjects with obesity. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Volume magnetostriction at the AF-FRI metamagnetic transition in the itinerant-electron system Mn2-xTxSb (T=Co, Cr)

    International Nuclear Information System (INIS)

    Bartashevich, M.I.; Goto, T.; Baranov, N.V.; Gaviko, V.S.

    2004-01-01

    Mn 2 Sb is a ferrimagnet, and substitution of Co or Cr for Mn above the critical concentration results in the appearance of a spontaneous first-order magnetic phase transition from ferrimagnetic (FRI) to antiferromagnetic (AF) with decreasing temperature below T t . At T t a first-order field-induced AF-FRI transition is observed at a critical field B c . The spontaneous as well as the field induced AF-FRI transition is accompanied by a significant magnetovolume effect. Magnetization under high pressure up to 12 kbar, magnetostriction of Mn 1.8 Co 0.2 Sb and Mn 1.94 Cr 0.04 Sb as well as thermal expansion of the Mn 1-x Co x Sb system has been measured in order to clarify the origin of the contradictory experimental results on the pressure effect on B c and that on T t , implying opposite changes. The observed differences are explained by the found anomalous change of sign of the magnetovolume effect at the AF-FRI transition with decreasing temperature

  9. 42 CFR 84.79 - Breathing gas; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing gas; minimum requirements. 84.79 Section...-Contained Breathing Apparatus § 84.79 Breathing gas; minimum requirements. (a) Breathing gas used to supply... respiratory tract irritating compounds. (c) Compressed, gaseous breathing air shall meet the applicable...

  10. 42 CFR 84.72 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.72...-Contained Breathing Apparatus § 84.72 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with breathing apparatus shall be designed and constructed to prevent: (a) Restriction...

  11. 42 CFR 84.85 - Breathing bags; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing bags; minimum requirements. 84.85 Section...-Contained Breathing Apparatus § 84.85 Breathing bags; minimum requirements. (a) Breathing bags shall have.... (b) Breathing bags shall be constructed of materials which are flexible and resistant to gasoline...

  12. A structural analysis of W-Sb mixed oxide catalyst

    International Nuclear Information System (INIS)

    Lim, Y.S.; Jung, S.H.; Hong, S.-T.; Jung, S.M.; Kim, J.; Chae, J.H.; Lee, W.-H.

    2005-01-01

    An investigation on the structure of W-Sb mixed oxide catalyst, W 12 Sb x O y (x = 1, 3, 5), is proposed. The W-Sb mixed oxide powders were prepared by the calcination of aqueous precursors, antimony tartrate and ammoniummetatungstate, and characterized with scanning electron microscope, X-ray diffractometer, and transmission electron microscope. At low content of Sb (x = 1), the W-Sb mixed oxide powder consisted of polyhedral particles, and their crystal structure was triclinic WO 3 . At higher content (x = 3, 5), majority of the oxide powders were bar-shaped particles, consisting of triclinic WO 3 and tetragonal WO 3 . With electron diffraction pattern and simulation, Sb incorporation into the cuboctahedral sites of perovskite-like WO 3 was proved and its effect on the phase transition from triclinic to tetragonal was discussed

  13. Spontaneous Tumor Lysis Syndrome

    Directory of Open Access Journals (Sweden)

    Alicia C. Weeks MD

    2015-08-01

    Full Text Available Tumor lysis syndrome (TLS is a known complication of malignancy and its treatment. The incidence varies on malignancy type, but is most common with hematologic neoplasms during cytotoxic treatment. Spontaneous TLS is thought to be rare. This case study is of a 62-year-old female admitted with multisystem organ failure, with subsequent diagnosis of aggressive B cell lymphoma. On admission, laboratory abnormalities included renal failure, elevated uric acid (20.7 mg/dL, and 3+ amorphous urates on urinalysis. Oliguric renal failure persisted despite aggressive hydration and diuretic use, requiring initiation of hemodialysis prior to chemotherapy. Antihyperuricemic therapy and hemodialysis were used to resolve hyperuricemia. However, due to multisystem organ dysfunction syndrome with extremely poor prognosis, the patient ultimately expired in the setting of a terminal ventilator wean. Although our patient did not meet current TLS criteria, she required hemodialysis due to uric acid nephropathy, a complication of TLS. This poses the clinical question of whether adequate diagnostic criteria exist for spontaneous TLS and if the lack of currently accepted guidelines has resulted in the underestimation of its incidence. Allopurinol and rasburicase are commonly used for prevention and treatment of TLS. Although both drugs decrease uric acid levels, allopurinol mechanistically prevents formation of the substrate rasburicase acts to solubilize. These drugs were administered together in our patient, although no established guidelines recommend combined use. This raises the clinical question of whether combined therapy is truly beneficial or, conversely, detrimental to patient outcomes.

  14. Environmental contamination and breathing disease

    International Nuclear Information System (INIS)

    Cardona A, Jose D

    2003-01-01

    The atmospheric contamination is the main component of the environmental contamination and it can be defined as the presence in the atmosphere of an or several substances in enough quantity to produce alterations of the health, it is presented in aerosol form, with its gassy and specific components, altering the quality of the population's life and the degradation of the ecosystems. The main pollutant, as much for the frequency as for the importance of its effects, is the smoke of cigarettes. The paper mentions other types of polluting agents and their effects in the breathing apparatus

  15. Sleep disordered breathing in pregnancy

    Directory of Open Access Journals (Sweden)

    Bilgay Izci Balserak

    2015-12-01

    Sleep disordered breathing (SDB is very common during pregnancy, and is most likely explained by hormonal, physiological and physical changes. Maternal obesity, one of the major risk factors for SDB, together with physiological changes in pregnancy may predispose women to develop SDB. SDB has been associated with poor maternal and fetal outcomes. Thus, early identification, diagnosis and treatment of SDB are important in pregnancy. This article reviews the pregnancy-related changes affecting the severity of SDB, the epidemiology and the risk factors of SDB in pregnancy, the association of SDB with adverse pregnancy outcomes, and screening and management options specific for this population.

  16. Thermal instability of GaSb surface oxide

    Science.gov (United States)

    Tsunoda, K.; Matsukura, Y.; Suzuki, R.; Aoki, M.

    2016-05-01

    In the development of InAs/GaSb Type-II superlattice (T2SL) infrared photodetectors, the surface leakage current at the mesa sidewall must be suppressed. To achieve this requirement, both the surface treatment and the passivation layer are key technologies. As a starting point to design these processes, we investigated the GaSb oxide in terms of its growth and thermal stability. We found that the formation of GaSb oxide was very different from those of GaAs. Both Ga and Sb are oxidized at the surface of GaSb. In contrast, only Ga is oxidized and As is barely oxidized in the case of GaAs. Interestingly, the GaSb oxide can be formed even in DI water, which results in a very thick oxide film over 40 nm after 120 minutes. To examine the thermal stability, the GaSb native oxide was annealed in a vacuum and analyzed by XPS and Raman spectroscopy. These analyses suggest that SbOx in the GaSb native oxide will be reduced to metallic Sb above 300°C. To directly evaluate the effect of oxide instability on the device performance, a T2SL p-i-n photodetector was fabricated that has a cutoff wavelength of about 4 μm at 80 K. As a result, the surface leakage component was increased by the post annealing at 325°C. On the basis of these results, it is possible to speculate that a part of GaSb oxide on the sidewall surface will be reduced to metallic Sb, which acts as an origin of additional leakage current path.

  17. Electrochemically Synthesized Sb/Sb2O3 Composites as High-Capacity Anode Materials Utilizing a Reversible Conversion Reaction for Na-Ion Batteries.

    Science.gov (United States)

    Hong, Kyung-Sik; Nam, Do-Hwan; Lim, Sung-Jin; Sohn, DongRak; Kim, Tae-Hee; Kwon, HyukSang

    2015-08-12

    Sb/Sb2O3 composites are synthesized by a one-step electrodeposition process from an aqueous electrolytic bath containing a potassium antimony tartrate complex. The synthesis process involves the electrodeposition of Sb simultaneously with the chemical deposition of Sb2O3, which allows for the direct deposition of morula-like Sb/Sb2O3 particles on the current collector without using a binder. Structural characterization confirms that the Sb/Sb2O3 composites are composed of approximately 90 mol % metallic Sb and 10 mol % crystalline Sb2O3. The composite exhibits a high reversible capacity (670 mAh g(-1)) that is higher than the theoretical capacity of Sb (660 mAh g(-1)). The high reversible capacity results from the conversion reaction between Na2O and Sb2O3 that occurs additionally to the alloying/dealloying reaction of Sb with Na. Moreover, the Sb/Sb2O3 composite shows excellent cycle performance with 91.8% capacity retention over 100 cycles, and a superior rate capability of 212 mAh g(-1) at a high current density of 3300 mA g(-1). The outstanding cycle performance is attributed to an amorphous Na2O phase generated by the conversion reaction, which inhibits agglomeration of Sb particles and acts as an effective buffer against volume change of Sb during cycling.

  18. Extubation after breathing trials with automatic tube compensation, T-tube, or pressure support ventilation.

    Science.gov (United States)

    Haberthür, C; Mols, G; Elsasser, S; Bingisser, R; Stocker, R; Guttmann, J

    2002-09-01

    Automatic tube compensation (ATC) is a new option to compensate for the pressure drop across the endotracheal or tracheostomy tube (ETT), especially during ventilator-assisted spontaneous breathing. While several benefits of this mode have so far been documented, ATC has not yet been used to predict whether the ETT could be safely removed at the end of weaning, from mechanical ventilation. We undertook a systematic trial using a randomized block design. During a 2-year period, all eligible patients of a medical intensive care unit were treated with ATC, conventional pressure support ventilation (PSV, 5 cmH2O), or T-tube for 2-h. Tolerance of the breathing trial served as a basis for the decision to remove the endotracheal tube. Extubation failure was considered if reintubation was necessary or if the patient required non-invasive ventilatory assistance (both within 48 h). After the inclusion of 90 patients (30 per group) we did not observe significant differences between the modes. Twelve patients failed the initial weaning trial. However, half of the patients who appeared to fail the spontaneous breathing trial on the T-tube, PSV, or both, were successfully extubated after a succeeding trial with ATC. Extubation was thus withheld from four and three of these patients while breathing with PSV or the T-tube, respectively, but to any patient breathing with ATC. It seems that ATC can be used as an alternative mode during the final phase of weaning from mechanical ventilation. Furthermore, this study may promote a larger multicenter trial on weaning with ATC compared with standard modes.

  19. Spontaneous Fluctuations of PO2 in the Rabbit Somatosensory Cortex.

    Science.gov (United States)

    Linsenmeier, Robert A; Aksenov, Daniil P; Faber, Holden M; Makar, Peter; Wyrwicz, Alice M

    2016-01-01

    In many tissues, PO2 fluctuates spontaneously with amplitudes of a few mmHg. Here we further characterized these oscillations. PO2 recordings were made from the whisker barrel cortex of six rabbits with acutely or chronically placed polarographic electrodes. Measurements were made while rabbits were awake and while anesthetized with isoflurane, during air breathing, and during 100% oxygen inspiration. In awake rabbits, 90% of the power was between 0 and 20 cycles per minute (cpm), not uniformly distributed over this range, but with a peak frequently near 10 cpm. This was much slower than heart or respiratory rhythms and is similar to the frequency content observed in other tissues. During hyperoxia, total power was higher than during air-breathing, and the dominant frequencies tended to shift toward lower values (0-10 cpm). These observations suggest that at least the lower frequency fluctuations represent efforts by the circulation to regulate local PO2. There were no consistent changes in total power during 0.5 or 1.5% isoflurane anesthesia, but the power shifted to lower frequencies. Thus, both hyperoxia and anesthesia cause characteristic, but distinct, changes in spontaneous fluctuations. These PO2 fluctuations may be caused by vasomotion, but other factors cannot be ruled out.

  20. AlSb as a high-energy photon detector

    International Nuclear Information System (INIS)

    Yee, J.H.; Swierkowski, S.P.; Sherohman, J.W.

    1977-01-01

    The possibility of using AlSb as a potential material for high-energy photon detection is examined by comparing the mobilities of the free carriers, the energy gap, the atomic number, and the carrier recombination time for AlSb, CdTe, Si, and Ge. It is concluded that at room temperature AlSb should be an intrinsically better high-energy photon detector than the three other materials. Simulated detector spectra for AlSb and CdTe are compared for ambient temperature detector performance

  1. Intrinsic interface states in InAs-AlSb heterostructures.

    Science.gov (United States)

    Raouafi, F; Benchamekh, R; Nestoklon, M O; Jancu, J-M; Voisin, P

    2016-02-03

    We examine the formation of intrinsic interface states bound to the plane of In-Sb chemical bonds at InAs-AlSb interfaces. Careful parameterization of the bulk materials in the frame of the extended-basis spds (*)tight-binding model and recent progress in predictions of band offsets severely limit the span of tight-binding parameters describing this system. We find that a heavy-hole-like interface state bound to the plane of In-Sb bonds exists for a large range of values of the InSb-InAs band offset.

  2. The system Sb2Te3-InS

    International Nuclear Information System (INIS)

    Safarov, M.G.; Gamidov, R.S.; Poladov, P.M.

    1991-01-01

    The system Sb 2 Te 3 -InS was investigated by the methods of physicochemical analysis. Its state diagram was constructed. It represents the stable diagonal of the mutual ternary system InTe-Sb 2 Te 3 -Sb 2 S 3 -InS. It was established that limited regions of α- and β-solid solutions on the basis of Sb 2 Te 3 and InS, achieving 15.5 and 8 mol.% respectively, formed in the system. Lattice periods of α- and β-solid solutions, their lattice volumes, number of atoms in them and densities were calculated

  3. Three-dimensional band structure of LaSb and CeSb: Absence of band inversion

    Science.gov (United States)

    Oinuma, H.; Souma, S.; Takane, D.; Nakamura, T.; Nakayama, K.; Mitsuhashi, T.; Horiba, K.; Kumigashira, H.; Yoshida, M.; Ochiai, A.; Takahashi, T.; Sato, T.

    2017-07-01

    We have performed angle-resolved photoemission spectroscopy (ARPES) of LaSb and CeSb, a candidate of topological insulators. Using soft-x-ray photons, we have accurately determined the three-dimensional bulk band structure and revealed that the band inversion at the Brillouin-zone corner, a prerequisite for realizing the topological-insulator phase, is absent in both LaSb and CeSb. Moreover, unlike the ARPES data obtained with soft-x-ray photons, those with VUV photons were found to suffer significant kz broadening. These results suggest that LaSb and CeSb are topologically trivial semimetals, and unusual Dirac-cone-like states observed with VUV photons are not of the topological origin.

  4. Magneto-transport studies of GaSb/InAs/GaSb double heterostructures Semiconductors

    CERN Document Server

    Takashina, K

    2002-01-01

    The electrical transport properties of GaSb/lnAs/GaSb double-heterostructures are examined experimentally. The structures are studied at low temperatures and high magnetic field. InAs/GaSb is a crossed-gap system where the conduction band minimum of InAs lies lower in energy than the valence band maximum of GaSb. The samples examined exploit this property to contain two-dimensional layers of electrons and holes. A description of the general electrical magneto-transport properties is given. Effects due to anticrossing behaviour between the electron and hole dispersion relations are demonstrated and discussed. It is shown that the anticrossing can lead to a non-monotonic temperature dependence of the resistivity. Under quantum Hall conditions, the system displays two types of behaviour. An insulating behaviour where both Hall and diagonal conductivities become vanishingly small, and a more conventional metallic behaviour where the Hall resistance is quantized and the diagonal resistivity disappears. It is found...

  5. Synthesis of B–Sb by rapid thermal annealing of B/Sb multilayer films

    Indian Academy of Sciences (India)

    layer with predetermined thickness of boron and antimony and subsequently subjecting the multilayer to rapid thermal annealing. The films were characterized by measuring microstructural, optical and compositional properties. 2. Experimental. Multilayer films of B and Sb were deposited onto Si and fused silica substrates ...

  6. Landau level transitions in InAs/AlSb/GaSb quantum wells

    International Nuclear Information System (INIS)

    Wu Xiao-Guang; Pang Mi

    2015-01-01

    The electronic structure of InAs/AlSb/GaSb quantum wells embedded in AlSb barriers and in the presence of a perpendicular magnetic field is studied theoretically within the 14-band k·p approach without making the axial approximation. At zero magnetic field, for a quantum well with a wide InAs layer and a wide GaSb layer, the energy of an electron-like subband can be lower than the energy of hole-like subbands. As the strength of the magnetic field increases, the Landau levels of this electron-like subband grow in energy and intersect the Landau levels of the hole-like subbands. The electron–hole hybridization leads to a series of anti-crossing splittings of the Landau levels. The magnetic field dependence of some dominant transitions is shown with their corresponding initial-states and final-states indicated. The dominant transitions at high fields can be roughly viewed as two spin-split Landau level transitions with many electron–hole hybridization-induced splittings. When the magnetic field is tilted, the electron-like Landau level transitions show additional anti-crossing splittings due to the subband-Landau level coupling. (paper)

  7. Study of the Raman spectra of phonons in disordered GaSb/AlSb (001) superlattices

    International Nuclear Information System (INIS)

    Berdekas, D.

    2010-01-01

    In the present work, we study the influence of disorder in the Raman spectra of the phonons of (GaSb) n /(AlSb) n (001) superlattices (SLs), for n = 1, 2. The disordered superlattices are approximated with primitive cells that are much larger than the primitive cells of the corresponding perfect SLs. We propose that disorder appears because of deviations from the sequence of the GaSb and AlSb layers, which is imposed by symmetry, or because of intermixing of Ga and Al in the cation lattice planes. The dynamical matrix of each SL is constructed from the combination of the dynamical matrices of the bulk crystalline constituents, which have been calculated at certain points of the Brillouin zone with a ten-parameter valence overlap shell model. Further, we have calculated the Raman spectra of the disordered 1 x 1 and 2 x 2 superlattices grown along the (001) direction, using an eight-parameter bond polarizability model, away from resonance conditions. Our results show that intermixing of Ga and Al cations produce Raman activity that is not present in the phonon spectra of perfect superlattices. (author)

  8. Ultrasound modulation in n-InSb

    International Nuclear Information System (INIS)

    Kondrat'ev, M.V.

    1978-01-01

    Presented are experimental results on ultrasound modulation at the frequency of about 10 MHz in n-InSb monocrystal by the variable magnetic field. The measurements are made in the range of stationary magnetic fields H 0 =1.7-17 kOe at 300 K. The data on dispersion and absorption of ultrasound due to conduction electrons are obtained with the help of a stationary technique of nuclear magnetic resonance. Theoretical interpretation of results is made which has shown that the Alfer-Rubin mechanism makes the main contribution into sound wave dispersion and magnetoresistance effect - into absorption

  9. Submarines, spacecraft and exhaled breath.

    Science.gov (United States)

    Pleil, Joachim D; Hansel, Armin

    2012-03-01

    Foreword The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled breath. What may have escaped our notice is a complementary field of research that explores the creation and maintenance of artificial atmospheres practised by the submarine air monitoring and air purification (SAMAP) community. SAMAP is comprised of manufacturers, researchers and medical professionals dealing with the engineering and instrumentation to support human life in submarines and spacecraft (including shuttlecraft and manned rockets, high-altitude aircraft, and the International Space Station (ISS)). Here, the immediate concerns are short-term survival and long-term health in fairly confined environments where one cannot simply 'open the window' for fresh air. As such, one of the main concerns is air monitoring and the main sources of contamination are CO(2) and other constituents of human exhaled breath. Since the inaugural meeting in 1994 in Adelaide, Australia, SAMAP meetings have been held every two or three years alternating between the North American and European continents. The meetings are organized by Dr Wally Mazurek (a member of IABR) of the Defense Systems Technology Organization (DSTO) of Australia, and individual meetings are co-hosted by the navies of the countries in which they are held. An overriding focus at SAMAP is life support (oxygen availability and carbon dioxide removal). Certainly, other air constituents are also important; for example, the closed environment of a submarine or the ISS can build up contaminants from consumer products, cooking, refrigeration, accidental fires, propulsion and atmosphere maintenance. However, the most immediate concern is sustaining human metabolism: removing exhaled CO(2) and replacing metabolized O(2). Another

  10. Spontaneous Intracranial Hypotension

    International Nuclear Information System (INIS)

    Joash, Dr.

    2015-01-01

    Epidemiology is not only rare but an important cause of new daily persistent headaches among young & middle age individuals. The Etiology & Pathogenesis is generally caused by spinal CSF leak. Precise cause remains largely unknown, underlying structural weakness of spinal meninges is suspected. There are several MR Signs of Intracranial Hypotension that include:- diffuse pachymeningeal (dural) enhancement; bilateral subdural, effusion/hematomas; Downward displacement of brain; enlargement of pituitary gland; Engorgement of dural venous sinuses; prominence of spinal epidural venous plexus and Venous sinus thrombosis & isolated cortical vein thrombosis. The sum of volumes of intracranial blood, CSF & cerebral tissue must remain constant in an intact cranium. Treatment in Many cases can be resolved spontaneously or by use Conservative approach that include bed rest, oral hydration, caffeine intake and use of abdominal binder. Imaging Modalities for Detection of CSF leakage include CT myelography, Radioisotope cisternography, MR myelography, MR imaging and Intrathecal Gd-enhanced MR

  11. Spontaneous wave packet reduction

    International Nuclear Information System (INIS)

    Ghirardi, G.C.

    1994-06-01

    There are taken into account the main conceptual difficulties met by standard quantum mechanics in dealing with physical processes involving macroscopic system. It is stressed how J.A.Wheeler's remarks and lucid analysis have been relevant to pinpoint and to bring to its extreme consequences the puzzling aspects of quantum phenomena. It is shown how the recently proposed models of spontaneous dynamical reduction represent a consistent way to overcome the conceptual difficulties of the standard theory. Obviously, many nontrivial problems remain open, the first and more relevant one being that of generalizing the model theories considered to the relativistic case. This is the challenge of the dynamical reduction program. 43 refs, 2 figs

  12. Investigation of interfaces in AlSb/InAs/Ga₀.₇₁In₀.₂₉Sb quantum wells by photoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Junliang, Xing; Yu, Zhang; Yongping, Liao; Juan, Wang; Wei, Xiang; Hongyue, Hao; Yingqiang, Xu; Zhichuan, Niu, E-mail: zcniu@semi.ac.cn [State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, 100083 Beijing (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2014-09-28

    We have investigated excitation power and temperature dependent PL spectra to systematically study the influences of the interfaces in the both InAs/Ga₀.₇₁In₀.₂₉Sb and InAs/AlSb on the optical properties of AlSb/Ga₀.₇₁In₀.₂₉Sb/InAs quantum wells (QWs). The localized states as well as the activation energy were analyzed to discuss the possible thermal quenching and non-radiative recombination mechanisms. We found two non-radiative recombination processes were involved in the thermal quenching of radiative emission for the QW structures. The GaAs-like interface in InAs/Ga₀.₇₁In₀.₂₉Sb with higher activation energy (62.7 meV) in high temperature region (70 K–300 K) supplies a deeper hole confinement and less roughness than the InSb-like one, which suppress non-radiative recombination process and promote the optical qualities of the quantum wells. The peak energy of the InSb-like sample exhibited “step-curve” behavior with increase temperature. Neither InSb-like nor AlAs-like interface in InAs/AlSb favored the radiative emission efficiency.

  13. Real-time assessment of In surface segregation during the growth of AlSb/InAs(Sb) heterostructures

    International Nuclear Information System (INIS)

    Prevot, I.; Vinter, B.; Marcadet, X.; Massies, J.

    2002-01-01

    Indium surface segregation is evidenced in real time by reflection high-energy electron diffraction (RHEED) during the molecular beam epitaxial growth of AlSb on InAs(Sb). The resulting interface width is determined from the RHEED specular beam intensity variation during the growth. It extends over several nanometers and increases with the growth temperature. Band structure simulations show that the indium segregation leads to a strong localization of the wave function associated to the first bound hole level at the AlSb on InAs(Sb) interface

  14. Heteroepitaxial growth of InSb films on a Si(0 0 1) substrate via AlSb buffer layer

    International Nuclear Information System (INIS)

    Mori, M.; Akae, N.; Uotani, K.; Fujimoto, N.; Tambo, T.; Tatsuyama, C.

    2003-01-01

    AlSb is a more suitable material as buffer layers for the heteroepitaxial growth of InSb films on a Si(0 0 1) substrate than Ge. It reduces the large lattice mismatch of about 19.3% between Si and InSb to about 5.6%. The resistance of AlSb with stoichiometric composition is large enough for the measurement of electrical properties. InSb films grown on the AlSb/Si(0 0 1) substrates by the co-evaporation of elemental indium (In) and antimony (Sb) sources were characterized by Auger electron spectroscopy (AES), X-ray diffraction (XRD) and atomic force microscopy (AFM), as a function of growth temperature. The thickness of grown InSb films was about 0.8-1.0 μm. The surface morphology and the crystal quality of the grown films strongly depend on growth temperature. It is found that the optimized growth temperature is about 300 deg. C to obtain the InSb films with smooth surface and good crystal quality

  15. Method for breathing related ECG triggering

    Energy Technology Data Exchange (ETDEWEB)

    Waters, W.; Neeb, W.; Wellner, U.

    1984-02-01

    A method for breathing related ECG triggering has been developed. It can be applied in radionuclid-angiocardioscintigraphy promising new insights into the physiology and pathophysiology of breathing related heart function without invasive manipulations. High resolution images of the heart can be obtained using this method by steering the NMR (nuclear magnetic resonance) or the cine CT (ultrafast transmission computerized tomography) acquisition.

  16. How Does a Hopping Kangaroo Breathe?

    Science.gov (United States)

    Giuliodori, Mauricio J.; Lujan, Heidi L.; Janbaih, Hussein; DiCarlo, Stephen E.

    2010-01-01

    We developed a model to demonstrate how a hopping kangaroo breathes. Interestingly, a kangaroo uses less energy to breathe while hopping than while standing still. This occurs, in part, because rather than using muscle power to move air into and out of the lungs, air is pulled into (inspiration) and pushed out of (expiration) the lungs as the…

  17. Breathing Better with a COPD Diagnosis

    Science.gov (United States)

    ... out of the lungs. Normal luNg CoPD luNg breathiNg better with a CoPD DiagNosis 3 DiagNosis aND ... Using a machine called a spirometer, this noninvasive breathing test measures the amount of air a person ...

  18. Significantly extended cutoff wavelength of very long-wave infrared detectors based on InAs/GaSb/InSb/GaSb superlattices

    Science.gov (United States)

    Jiang, Dongwei; Han, Xi; Hao, Hongyue; Sun, Yaoyao; Jiang, Zhi; Lv, Yuexi; Guo, Chunyan; Wang, Guowei; Xu, Yingqiang; Yu, Yang; Niu, Zhichuan

    2017-10-01

    The authors report significant tunability of the bandgap in very long-wave infrared (VLWIR) InAs/GaSb/InSb/GaSb superlattices. Calculations using the empirical tight binding method have shown the flexibility in tuning the energy levels of the valence band by inserting a thin InSb layer in the middle of the GaSb layer of a normal type-II binary InAs/GaSb superlattice. Through the experimental realization of several barrier structure photodiodes with 15 ML InAs/7 ML GaSb active region, the cutoff wavelength was extended from 14.5 μm to 18.2 μm by inserting 0.6 ML InSb at different locations in GaSb layer. The agreement between the theoretical predictions and the experimental measurement suggests a way to exploit this advantage for the realization of very long-wave infrared detection without increasing the thickness of InAs layer. At 77 K, the quantum efficiency of a very long-wave detector with the cutoff wavelength of 16.9 μm reached at a maximum value of 30%, and the R0A is kept at a stable value of 10 Ω cm2 with the peak detectivity of 2.73 × 1011 cm Hz1/2/W. The operability and the uniformity in responsivity of the 320 × 256 very long-wave focal plane arrays were 88% and 80%. The noise equivalent temperature difference at 65 K presents a peak at 25 mK, corresponding to an average value of 60 mK, with an integration time of 0.5 ms, a 300 K background, and f/2 optics.

  19. The effect of breath freshener strips on two types of breath alcohol testing instruments.

    Science.gov (United States)

    Moore, Ronald L; Guillen, Jennifer

    2004-07-01

    The potential for breath freshener strips to interfere with the accuracy of a breath alcohol test was studied. Twelve varieties of breath freshener strips from five manufacturers were examined. Breath tests were conducted using the infrared based BAC DataMaster or the fuel cell based Alco-Sensor IV-XL, 30 and 150 seconds after placing a breath strip on the tongue. No effect was observed using the Alco-Sensor system. Some of the strips gave a small reading at 30 seconds (less than or equal to 0.010 g/210 L apparent alcohol) using the DataMaster. Readings on the DataMaster returned to zero by the 150 second test. A proper pre-test observation and deprivation period should prevent any interference from breath freshener strips on breath alcohol testing.

  20. Pattern of breathing in brachycephalic dogs.

    Science.gov (United States)

    Amis, T C; Kurpershoek, C

    1986-10-01

    The pattern of breathing was assessed in 19 brachycephalic dogs, using tidal breathing flow-volume loop (TBFVL) analysis. Fifteen dogs had TBFVL consistent with a fixed-type upper airway obstruction, whereas 4 dogs had a TBFVL indicative of a nonfixed upper airway obstruction. The dogs did not have a TBFVL shape the same as that considered normal for healthy nonbrachycephalic dogs. Tidal breathing flow-volume loops from brachycephalic dogs that were considered to have a normal respiratory tract (n = 11) were similar to those of dogs with clinical signs of upper airway obstruction (n = 8). Respiration was monitored continuously for short periods (20 to 50 minutes) in 3 brachycephalic dogs resting in a cage in a quiet, darkened laboratory; 2 of these dogs had periodic breathing patterns characterized by multiple episodes of alternating hypopnea and arousal. Brachycephalic dogs may be at risk for the development of disordered breathing during sleep.

  1. BREATH OF USE AND VOCAL TRAINING

    Directory of Open Access Journals (Sweden)

    Nuran ACAR

    2016-10-01

    Full Text Available Breathable, who escorted us in every aspect of our lives and our survival is our primary activity, allowing for quality of life in a healthy way. quality of breaths taken the right technique, you need both health professional sense should perhaps take advantage of individuals who want to achieve success in life is the primary rule. When the diaphragm is born with assisted breathing lungs of every person's life starts to grow to keep up with the flurry lose this special and important skills. First and foremost, which is important for our body health, including every aspect of proper breathing, especially correct use of the voice carries particular importance. In this article, breathing subject discussed, correct breathing and our lives have tried to give us information about the benefits of both vocal training.

  2. Rapid eye movement sleep in breath holders.

    Science.gov (United States)

    Kohyama, J; Hasegawa, T; Shimohira, M; Fukumizu, M; Iwakawa, Y

    2000-07-01

    One-night polysomnography was performed on seven subjects suffering from breath-holding spells, including one whose death was suggested to be a consequence of a breath-holding spell. The fatal case showed no rapid eye movements (REMs) during REM sleep, although he exhibited REMs during wakefulness. The average numbers of both REMs and bursts of REMs in REM sleep in the other six breath holders were significantly lower than those in age-matched controls. The breath holders showed no airway obstruction, desaturation, or sleep fragmentation. Since the rapid ocular activity in REM sleep is generated in the brain stem, we hypothesized that a functional brainstem disturbance is involved in the occurrence of breath-holding spells.

  3. Crystallographic study of the intermediate compounds SbZn, Sb{sub 3}Zn{sub 4} and Sb{sub 2}Zn{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Adjadj, Fouzia [Laboratoire des etudes Physico-chimiques des Materiaux, Departement de Physique, Faculte des Sciences, Universite de Batna, 05000 Batna (Algeria); Belbacha, El-djemai [Laboratoire des etudes Physico-chimiques des Materiaux, Departement de Physique, Faculte des Sciences, Universite de Batna, 05000 Batna (Algeria)]. E-mail: Beldjem@caramail.com; Bouharkat, Malek [Laboratoire des etudes Physico-chimiques des Materiaux, Departement de Physique, Faculte des Sciences, Universite de Batna, 05000 Batna (Algeria); Kerboub, Abdellah [Laboratoire des etudes Physico-chimiques des Materiaux, Departement de Physique, Faculte des Sciences, Universite de Batna, 05000 Batna (Algeria)

    2006-08-10

    The processes of development of semiconductor ceramics made up of bismuth, antimony and zinc often require during their preparation to know the nature of the involved phases. For that, it is always essential to refer to the diagrams of balance between phases of the binary systems or ternary. We presented in this work the study by X-rays diffraction relating to the intermediate compounds SbZn, Sb{sub 3}Zn{sub 4} and Sb{sub 2}Zn{sub 3}. The analysis by X-rays is often useful to give supplement the results of the other experimental methods.

  4. Effect of probenecid on breathing movements and cerebral clearance of prostaglandin E2 in fetal sheep

    Science.gov (United States)

    Walker, David W; Pratt, Naomi

    1998-01-01

    Intravenous infusion of probencid (79-160 mg kg−1) into unanaesthetized fetal sheep (127-143 days gestation) in utero significantly decreased the incidence and amplitude of spontaneous breathing movements, but did not change the incidence of low voltage electrocortical (ECoG) activity, plasma prostaglandin E2 (PGE2) concentrations, blood gases or pH. In fetuses pretreated with paracetamol (350 mg kg−1) to inhibit PG synthase activity, infusion of probenecid did not change the mean incidence or amplitude of breathing movements, indicating that the inhibitory effect of probenecid on breathing movements required the presence of active PG synthesis. Probenecid infusion in four unanaesthetized fetuses significantly increased the PGE2 concentrations in cisternal cerebrospinal fluid (CSF) by 6.6 ± 1.5-fold (P probenecid infusion decreased the clearance of [3H]PGE2 from CSF during ventriculo-cisternal perfusion of artificial CSF containing [3H]PGE2. These results suggest that there is active transport of PGs from CSF to blood in fetal sheep from at least 127 days gestation. Inhibition of this transport results in the accumulation of PGs within interstitial fluid of the brain, one effect of which is to suppress the spontaneous activity of the respiratory centres. PMID:9481686

  5. Spontaneous compactification to homogeneous spaces

    International Nuclear Information System (INIS)

    Mourao, J.M.

    1988-01-01

    The spontaneous compactification of extra dimensions to compact homogeneous spaces is studied. The methods developed within the framework of coset space dimensional reduction scheme and the most general form of invariant metrics are used to find solutions of spontaneous compactification equations

  6. Screening for spontaneous preterm birth

    NARCIS (Netherlands)

    van Os, M.A.; van Dam, A.J.E.M.

    2015-01-01

    Preterm birth is the most important cause of perinatal morbidity and mortality worldwide. In this thesis studies on spontaneous preterm birth are presented. The main objective was to investigate the predictive capacity of mid-trimester cervical length measurement for spontaneous preterm birth in a

  7. Spontaneous Pneumomediastinum: Hamman Syndrome

    Directory of Open Access Journals (Sweden)

    Tushank Chadha, BS

    2018-04-01

    significant fat stranding. The image also showed an intraluminal stent traversing the gastric antrum and gastric pylorus with no indication of obstruction. Circumferential mural thickening of the gastric antrum and body were consistent with the patient’s history of gastric adenocarcinoma. The shotty perigastric lymph nodes with associated fat stranding, along the greater curvature of the distal gastric body suggested local regional nodal metastases and possible peritoneal carcinomatosis. The thoracic CT scans showed extensive pneumomediastinum that tracked into the soft tissues of the neck, which given the history of vomiting also raised concern for esophageal perforation. There was still no evidence of mediastinal abscess or fat stranding. Additionally, a left subclavian vein port catheter, which terminates with tip at the cavoatrial junction of the superior vena cava can also be seen on the image. Discussion: Spontaneous Pneumomediastinum, also known as Hamman syndrome, is defined by the uncommon incidence of free air in the mediastinum due to the bursting of alveoli, as a result of extended spells of shouting, coughing, or vomiting.1,2 The condition is diagnosed when a clear cause (aerodigestive rupture, barotrauma, infection secondary to gas-forming organisms3 for pneumomediastinum cannot be clearly identified on diagnostic studies. Macklin and Macklin were the first to note the pathogenesis of the syndrome and explained that the common denominator to spontaneous pneumomediastinum was that increased alveolar pressure leads to alveolar rupture.3 Common clinical findings for spontaneous pneumomediastinum include: chest pain, dyspnea, cough, and emesis.4 The condition is not always readily recognized on initial presentation in part for its rare incidence, estimated to be approximately 1 in every 44,500 ED patients3and also because of the non-specific presenting symptoms. For this patient, there was no clear singular cause, and therefore she received care for spontaneous

  8. Acceleration sensors in abdominal wall position as a non-invasive approach to detect early breathing alterations induced by intolerance of increased airway resistance.

    Science.gov (United States)

    Breuer, Thomas; Bruells, Christian S; Rossaint, Rolf; Steffen, Henning; Disselhorst-Klug, Catherine; Czaplik, Michael; Zoremba, Norbert

    2017-11-10

    Early detection of respiratory overload is crucial to mechanically ventilated patients, especially during phases of spontaneous breathing. Although a diversity of methods and indices has been established, there is no highly specific approach to predict respiratory failure. This study aimed to evaluate acceleration sensors in abdominal and thoracic wall positions to detect alterations in breathing excursions in a setting of gradual increasing airway resistance. Twenty-nine healthy volunteers were committed to a standardized protocol of a two-minutes step-down spontaneous breathing on a 5 mm, 4 mm and then 3 mm orally placed endotracheal tube. Accelerator sensors in thoracic and abdominal wall position monitored breathing excursions. 15 participants passed the breathing protocol ("completed" group), 14 individuals cancelled the protocol due to subjective intolerance to the increasing airway resistance ("abandoned" group). Gradual increased respiratory workload led to a significant decrease of acceleration in abdominal wall position in the "abandoned" group compared to the "completed" group (p breathing alterations prior to respiratory failure. EK 309-15; by the Ethics Committee of the Faculty of Medicine, RWTH Aachen, Aachen, Germany. Retrospectively registered 28th of December 2015.

  9. Horses Auto-Recruit Their Lungs by Inspiratory Breath Holding Following Recovery from General Anaesthesia.

    Science.gov (United States)

    Mosing, Martina; Waldmann, Andreas D; MacFarlane, Paul; Iff, Samuel; Auer, Ulrike; Bohm, Stephan H; Bettschart-Wolfensberger, Regula; Bardell, David

    2016-01-01

    This study evaluated the breathing pattern and distribution of ventilation in horses prior to and following recovery from general anaesthesia using electrical impedance tomography (EIT). Six horses were anaesthetised for 6 hours in dorsal recumbency. Arterial blood gas and EIT measurements were performed 24 hours before (baseline) and 1, 2, 3, 4, 5 and 6 hours after horses stood following anaesthesia. At each time point 4 representative spontaneous breaths were analysed. The percentage of the total breath length during which impedance remained greater than 50% of the maximum inspiratory impedance change (breath holding), the fraction of total tidal ventilation within each of four stacked regions of interest (ROI) (distribution of ventilation) and the filling time and inflation period of seven ROI evenly distributed over the dorso-ventral height of the lungs were calculated. Mixed effects multi-linear regression and linear regression were used and significance was set at pbreath holding until 5 hours after standing. No change from baseline was seen for the distribution of ventilation during inspiration. Filling time and inflation period were more rapid and shorter in ventral and slower and longer in most dorsal ROI compared to baseline, respectively. In a mixed effects multi-linear regression, breath holding was significantly correlated with PaCO2 in both the univariate and multivariate regression. Following recovery from anaesthesia, horses showed inspiratory breath holding during which gas redistributed from ventral into dorsal regions of the lungs. This suggests auto-recruitment of lung tissue which would have been dependent and likely atelectic during anaesthesia.

  10. Spontaneous sigh rates during sedentary activity: watching television vs reading.

    Science.gov (United States)

    Hark, William T; Thompson, William M; McLaughlin, Timothy E; Wheatley, Lisa M; Platts-Mills, Thomas A E

    2005-02-01

    Spontaneous sighs are thought to play an important role in preventing atelectasis and in regulating airway tone. Recent studies have provided a mechanism by which expansion of the lungs could cause relaxation of smooth muscle. To investigate breathing patterns during 2 forms of sedentary behavior: reading and watching television. Breathing patterns were monitored for 1 to 2 hours to document respiratory rates and sigh rates. Each participant was monitored while reading and while watching a movie on videotape. During the first experiment (17 controls), metabolic rates were also measured. In the second experiment (18 controls and 9 patients with mild-to-moderate asthma), only breathing patterns were monitored. There were no significant differences in respiratory or metabolic rates between the 2 activities. In contrast, in the first experiment, 13 of 17 controls had lower sigh rates while watching a videotape than while reading (P < .01). In the second experiment, the sigh rate was significantly lower overall while watching a videotape (mean, 13.7 sighs per hour; range, 1.8-26.0 sighs per hour) than while reading (mean, 19.3 sighs per hour; range, 7.7-30.0 sighs per hour) (P < .001). A similar decrease was observed in patients with asthma (P < .01). Given that many children and adults watch television for 5 or more hours per day, breathing patterns during this time may be relevant to lung function. Our results demonstrate that prolonged periods of watching a videotape are associated with lower sigh rates than while reading. Further research is needed to determine whether these changes are relevant to increased bronchial reactivity.

  11. Infrared Emitters and Photodetectors with InAsSb Bulk Active Region

    Science.gov (United States)

    2013-04-29

    of the epitaxial layer and the substrate. Bulk lnAsSb layers with a narrow PL spectrum were grown with Al0.7Ino.3Sb/ AlSb Strained Layer Superlattice...Lett., 89, 201ll5 (2006). [17]. Wu B.-R., Liao C., and Cheng K. Y., "High quality InAsSb grown on InP substrates using AlSb /AlAsSb buffer layers

  12. Structural and Optical Characteristics of Metamorphic Bulk InAsSb

    Science.gov (United States)

    2014-01-01

    heterostructure detectors with bulk InAsSb absorbers and AlSb -based barriers. These structures can outperform InSb homojunction photodetectors operating...Wu B.-R., Liao C., and Cheng K. Y., “High quality InAsSb grown on InP substrates using AlSb /AlAsSb buffer layers”, Appl. Phys. Lett., 92, 062111

  13. Sleep disordered breathing in children.

    Science.gov (United States)

    Sinha, Deepti; Guilleminault, Christian

    2010-02-01

    Sleep disordered breathing (SDB) is increasingly being recognised as a cause of morbidity even in young children. With an estimated prevalence of 1 to 4 per cent, SDB results from having a structurally narrow airway combined with reduced neuromuscular tone and increased airway collapsibility. SDB in children differs from adults in a number of ways, including presenting symptoms and treatment. Presentation may differ according to the age of the child. Children have a more varied presentation from snoring and frequent arousals to enuresis to hyperactivity. Those with Down syndrome, midface hypoplasia or neuromuscular disorders are at higher risk for developing SDB. First line definitive treatment in children involves tonsillectomy and adenoidectomy. Rapid maxillary expansion, allergy treatment and continuous positive airway pressure (CPAP) are other options. As untreated SDB results in complications as learning difficulties, memory loss and a long term increase in risk of hypertension, depression and poor growth, it is important to diagnose SDB.

  14. Time Breath of Psychological Theories

    DEFF Research Database (Denmark)

    Tateo, Luca; Valsiner, Jaan

    2015-01-01

    Psychology as a self-aspiring, ambitious, developmental science faces the crucial limit of time—both theoretically and practically. The issue of time in constructing psychology’s theories is a major unresolved metatheoretical task. This raises several questions about generalization of knowledge......: which is the time length of breath of psychological theories? Which is the temporal dimension of psychological processes? In this article we discuss the role of different axiomatic assumptions about time in the construction of psychological theories. How could different theories include a concept...... of time—or fail to do that? How can they generalize with respect to time? The different conceptions of time often remain implicit, while shaping the concepts used in understanding psychological processes. Any preconception about time in human development will foster the generalizability of theory, as well...

  15. The indoor air we breathe.

    Science.gov (United States)

    Oliver, L C; Shackleton, B W

    1998-01-01

    Increasingly recognized as a potential public health problem since the outbreak of Legionnaire's disease in Philadelphia in 1976, polluted indoor air has been associated with health problems that include asthma, sick building syndrome, multiple chemical sensitivity, and hypersensitivity pneumonitis. Symptoms are often nonspecific and include headache, eye and throat irritation, chest tightness and shortness of breath, and fatigue. Air-borne contaminants include commonly used chemicals, vehicular exhaust, microbial organisms, fibrous glass particles, and dust. Identified causes include defective building design and construction, aging of buildings and their ventilation systems, poor climate control, inattention to building maintenance. A major contributory factor is the explosion in the use of chemicals in building construction and furnishing materials over the past four decades. Organizational issues and psychological variables often contribute to the problem and hinder its resolution. This article describes the health problems related to poor indoor air quality and offers solutions.

  16. Antiferromagnetism in semiconducting SrMn2Sb2 and BaMn2Sb2 single crystals

    Science.gov (United States)

    Sangeetha, N. S.; Smetana, V.; Mudring, A.-V.; Johnston, D. C.

    2018-01-01

    Crystals of SrMn2Sb2 and BaMn2Sb2 were grown using Sn flux and characterized by powder and single-crystal x-ray diffraction, respectively, and by single-crystal electrical resistivity ρ , heat capacity Cp, and magnetic susceptibility χ measurements versus temperature T , and magnetization versus field M (H ) isotherm measurements. SrMn2Sb2 adopts the trigonal CaAl2Si2 -type structure, whereas BaMn2Sb2 crystallizes in the tetragonal ThCr2Si2 -type structure. The ρ (T ) data indicate semiconducting behaviors for both compounds with activation energies of ≳0.35 eV for SrMn2Sb2 and 0.16 eV for BaMn2Sb2 . The χ (T ) and Cp(T ) data reveal antiferromagnetic (AFM) ordering at TN = 110 K for SrMn2Sb2 and 450 K for BaMn2Sb2 . The anisotropic χ (T ≤TN) data also show that the ordered moments in SrMn2Sb2 are aligned in the hexagonal a b plane, whereas the ordered moments in BaMn2Sb2 are aligned collinearly along the tetragonal c axis. The a b -plane M (H ) data for SrMn2Sb2 exhibit a continuous metamagnetic transition at low fields 0 survey of the literature for Mn pnictides with the CaAl2Si2 and ThCr2Si2 crystal structures show that the TN values for the CaAl2Si2 -type compounds are much smaller than those for the ThCr2Si2 -type materials.

  17. X-Ray Investigations on Molten Cu-Sb Alloys

    Science.gov (United States)

    Halm, Th.; Neumann, H.; Hoyer, W.

    1994-05-01

    Using X-ray diffraction, structure factors and pair correlation functions of several molten Cu-Sb alloys and pure antimony were determined and compared with published structural, thermodynamic and electronic properties. The eutectic concentration Cu37Sb63 was investigated in dependence on temperature, and a model structure factor was calculated applying a segregation model.

  18. Fast-starting after a breath: air-breathing motions are kinematically similar to escape responses in the catfish Hoplosternum littorale

    Directory of Open Access Journals (Sweden)

    Paolo Domenici

    2014-12-01

    Full Text Available Fast-starts are brief accelerations commonly observed in fish within the context of predator–prey interactions. In typical C-start escape responses, fish react to a threatening stimulus by bending their body into a C-shape during the first muscle contraction (i.e. stage 1 which provides a sudden acceleration away from the stimulus. Recently, similar C-starts have been recorded in fish aiming at a prey. Little is known about C-starts outside the context of predator–prey interactions, though recent work has shown that escape response can also be induced by high temperature. Here, we test the hypothesis that air-breathing fish may use C-starts in the context of gulping air at the surface. Hoplosternum littorale is an air-breathing freshwater catfish found in South America. Field video observations reveal that their air-breathing behaviour consists of air-gulping at the surface, followed by a fast turn which re-directs the fish towards the bottom. Using high-speed video in the laboratory, we compared the kinematics of the turn immediately following air-gulping performed by H. littorale in normoxia with those of mechanically-triggered C-start escape responses and with routine (i.e. spontaneous turns. Our results show that air-breathing events overlap considerably with escape responses with a large stage 1 angle in terms of turning rates, distance covered and the relationship between these rates. Therefore, these two behaviours can be considered kinematically comparable, suggesting that air-breathing in this species is followed by escape-like C-start motions, presumably to minimise time at the surface and exposure to avian predators. These findings show that C-starts can occur in a variety of contexts in which fish may need to get away from areas of potential danger.

  19. Evidence for a topological excitonic insulator in InAs/GaSb bilayers.

    Science.gov (United States)

    Du, Lingjie; Li, Xinwei; Lou, Wenkai; Sullivan, Gerard; Chang, Kai; Kono, Junichiro; Du, Rui-Rui

    2017-12-07

    Electron-hole pairing can occur in a dilute semimetal, transforming the system into an excitonic insulator state in which a gap spontaneously appears at the Fermi surface, analogous to a Bardeen-Cooper-Schrieffer (BCS) superconductor. Here, we report optical spectroscopic and electronic transport evidence for the formation of an excitonic insulator gap in an inverted InAs/GaSb quantum-well system at low temperatures and low electron-hole densities. Terahertz transmission spectra exhibit two absorption lines that are quantitatively consistent with predictions from the pair-breaking excitation dispersion calculated based on the BCS gap equation. Low-temperature electronic transport measurements reveal a gap of ~2 meV (or ~25 K) with a critical temperature of ~10 K in the bulk, together with quantized edge conductance, suggesting the occurrence of a topological excitonic insulator phase.

  20. Effect of applied orthorhombic lattice distortion on the antiferromagnetic phase of CeAuSb2

    Science.gov (United States)

    Park, Joonbum; Sakai, Hideaki; Erten, Onur; Mackenzie, Andrew P.; Hicks, Clifford W.

    2018-01-01

    We study the response of the antiferromagnetism of CeAuSb2 to orthorhombic lattice distortion applied through in-plane uniaxial pressure. The response to pressure applied along a 〈110 〉 lattice direction shows a first-order transition at zero pressure, which shows that the magnetic order spontaneously lifts the (110 ) /(1 1 ¯0 ) symmetry of the unstressed lattice. Sufficient 〈100 〉 pressure appears to rotate the principal axes of the order from 〈110 〉 to 〈100 〉 . At low 〈100 〉 pressure, the transition at TN is weakly first order; however, it becomes continuous above a threshold 〈100 〉 pressure. We discuss the possibility that this behavior is driven by order parameter fluctuations, with the restoration of a continuous transition being a result of reducing the point-group symmetry of the lattice.

  1. Substitutionality of Ge atoms in ion implanted AlSb

    International Nuclear Information System (INIS)

    Yu, K.M.; Moll, A.J.; Chan, N.; Walukiewicz, W.; Becla, P.

    1995-01-01

    The substitution of Ge atoms into ion implanted AlSb is investigated by extended x-ray absorption fine structure spectroscopy. Our results reveal that in the as-implanted material, the implanted Ge atoms are equally distributed between two specific sites, one surrounded by Al atoms and the other surrounded by Sb atoms. After annealing at 750 degree C for 5 s, the coordination number of the Ge atoms increases from ∼3 to ∼4 indicating solid phase regrowth of the implantation induced amorphous surface layer. Moreover, in the annealed AlSb, the substitution of Ge atoms into the Al sublattice dominates with an estimated Ge Al :[Ge Sb ]∼0.8:0.2. These results suggest that Ge atoms act preferentially as donor species in AlSb

  2. Effects of Y, Nd and Sb on microstructure of Mg-6Al alloy

    Science.gov (United States)

    Li, Ke-jie

    2017-09-01

    Effects of Y, Nd and Sb on the microstructure of Mg-6Al magnesium alloy were investigated by optical microscope, SEM, EDS, XRD and TEM. The results showed that, with the increase of Sb content from 0.5% to 2.0wt%, the formation of Sb3Y5 (at 1.0% Sb) or YSb (at 2.0% Sb) phase is observed. Sb3Y5 nano-phase and dispersed Al2Y, SbY phases are found in the alloy when the content of Sb reaches 2.0%.

  3. The synthesis and structure of two filled skutterudite compounds: BaFe 4Sb 12 and BaRu 4Sb 12

    Science.gov (United States)

    Stetson, Ned T.; Kauzlarich, Susan M.; Hope, Håkon

    1991-03-01

    Two compounds, Ba T4Sb 12 ( T = Fe, Ru), have been synthesized using high temperature methods. These compounds crystallize in the cubic LaFe 4P 12 structure type. Two methods are described for the synthesis of BaFe 4Sb 12. Single crystals of BaFe 4Sb 12 can be prepared by reacting BaSb, Fe, and Sb in a 1:4:18 (Ba:Fe:Sb) molar ratio (method I). Single crystal X-ray diffraction data (room temperature, a = 9.200(3) Å) for BaFe 4Sb 12 prepared by Method I were refined (cubic, Im overline3 (No. 204), Z = 2, R = 1.96%, Rw = 1.73% for 179 independent reflections). BaFe 4Sb 12 can also be prepared in ≥80% yield from the reaction of stoichiometric amounts of Ba 2Sb 3, FeSb 2, and Sb (method II). Low temperature (130 K, a = 9.188(2)) single crystal X-ray diffraction data on BaFe 4Sb 12 crystals produced from Method II were also measured and refined ( R = 2.29%, Rw = 2.45% for 179 independent reflections). The structure of BaFe 4Sb 12 will be compared to that of the LaFe 4Sb 12 and CoSb 3.

  4. Immediate effects of breath holding maneuvers onto composition of exhaled breath.

    Science.gov (United States)

    Sukul, Pritam; Trefz, Phillip; Schubert, Jochen K; Miekisch, Wolfram

    2014-09-01

    Rapid concentration changes due to physiological or pathophysiological effects rather than appearance of unique disease biomarkers are important for clinical application of breath research. Simple maneuvers such as breath holding may significantly affect breath biomarker concentrations. In this study, exhaled volatile organic compound (VOC) concentrations were assessed in real time before and after different breath holding maneuvers. Continuous breath-resolved measurements (PTR-ToF-MS-8000) were performed in 31 healthy human subjects in a side-stream sampling mode. After 1 min of tidal breathing participants held their breath for 10, 20, 40, 60 s and as long as possible. Afterwards they continued to breathe normally for another minute. VOC profiles could be monitored in real time by assigning online PTR-ToF-MS data to alveolar or inspired phases of breath. Sudden and profound changes of exhaled VOC concentrations were recorded after different breath holding maneuvers. VOC concentrations returned to base line levels 10-20 s after breath holding. Breath holding induced concentration changes depended on physico-chemical properties of the substances. When substance concentrations were normalized onto end-tidal CO2 content, variation of acetone concentrations decreased, whereas variations of isoprene concentrations were not affected. As the effects of breathing patterns on exhaled substance concentrations depend on individual substance properties, sampling procedures have to be validated for each compound by means of appropriate real-time analysis. Normalization of exhaled concentrations onto exhaled CO2 is only valid for substances having similar physico-chemical properties as CO2.

  5. Spontaneous breaking of supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Zumino, B.

    1981-12-01

    There has been recently a revival of interest in supersymmetric gauge theories, stimulated by the hope that supersymmetry might help in clarifying some of the questions which remain unanswered in the so called Grand Unified Theories and in particular the gauge hierarchy problem. In a Grand Unified Theory one has two widely different mass scales: the unification mass M approx. = 10/sup 15/GeV at which the unification group (e.g. SU(5)) breaks down to SU(3) x SU(2) x U(1) and the mass ..mu.. approx. = 100 GeV at which SU(2) x U(1) is broken down to the U(1) of electromagnetism. There is at present no theoretical understanding of the extreme smallness of the ratio ..mu../M of these two numbers. This is the gauge hierarchy problem. This lecture attempts to review the various mechanisms for spontaneous supersymmetry breaking in gauge theories. Most of the discussions are concerned with the tree approximation, but what is presently known about radiative correction is also reviewed.

  6. Spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Haritanti, A.; Karacostas, D.; Drevelengas, A.; Kanellopoulos, V.; Paraskevopoulou, E.; Lefkopoulos, A.; Economou, I.; Dimitriadis, A.S.

    2009-01-01

    Spontaneous intracranial hypotension (SIH) is an uncommon but increasingly recognized syndrome. Orthostatic headache with typical findings on magnetic resonance imaging (MRI) are the key to diagnosis. Delayed diagnosis of this condition may subject patients to unnecessary procedures and prolong morbidity. We describe six patients with SIH and outline the important clinical and neuroimaging findings. They were all relatively young, 20-54 years old, with clearly orthostatic headache, minimal neurological signs (only abducent nerve paresis in two) and diffuse pachymeningeal gadolinium enhancement on brain MRI, while two of them presented subdural hygromas. Spinal MRI was helpful in detecting a cervical cerebrospinal fluid leak in three patients and dilatation of the vertebral venous plexus with extradural fluid collection in another. Conservative management resulted in rapid resolution of symptoms in five patients (10 days-3 weeks) and in one who developed cerebral venous sinus thrombosis, the condition resolved in 2 months. However, this rapid clinical improvement was not accompanied by an analogous regression of the brain MR findings that persisted on a longer follow-up. Along with recent literature data, our patients further point out that SIH, to be correctly diagnosed, necessitates increased alertness by the attending physician, in the evaluation of headaches

  7. Spontaneous lateral temporal encephalocele.

    Science.gov (United States)

    Tuncbilek, Gokhan; Calis, Mert; Akalan, Nejat

    2013-01-01

    A spontaneous encephalocele is one that develops either because of embryological maldevelopment or from a poorly understood postnatal process that permits brain herniation to occur. We here report a rare case of lateral temporal encephalocele extending to the infratemporal fossa under the zygomatic arch. At birth, the infant was noted to have a large cystic mass in the right side of the face. After being operated on initially in another center in the newborn period, the patient was referred to our clinic with a diagnosis of temporal encephalocele. He was 6 months old at the time of admission. Computerized tomography scan and magnetic resonance imaging studies revealed a 8 × 9 cm fluid-filled, multiloculated cystic mass at the right infratemporal fossa. No intracranial pathology or connection is seen. The patient was operated on to reduce the distortion effect of the growing mass. The histopathological examination of the sac revealed well-differentiated mature glial tissue stained with glial fibrillary acid protein. This rare clinical presentation of encephaloceles should be taken into consideration during the evaluation of the lateral facial masses in the infancy period, and possible intracranial connection should be ruled out before surgery to avoid complications.

  8. Breathing changes accompanying balance improvement during biofeedback.

    Science.gov (United States)

    Hirjaková, Zuzana; Neumannová, Kateřina; Kimijanová, Jana; Šuttová, Kristína; Janura, Miroslav; Hlavačka, František

    2017-06-09

    The aim of this study was to determine whether respiration would be altered during visual biofeedback condition while standing on a foam surface. Fifty young, healthy subjects (24 men, 26 women) were divided into a spirometry group, in which additional spirometry analysis was performed, and a control group. All subjects were tested in two conditions: 1) standing on a foam surface and 2) standing on a foam surface with visual biofeedback (VF) based on the centre of pressure (CoP). CoP amplitude and velocity in anterior-posterior (Aap, Vap) and medial-lateral (Aml, Vml) directions were measured by the force platform. Breathing movements were recorded by two pairs of 3D accelerometers attached on the upper chest (upper chest breathing - UCB) and the lower chest (lower chest breathing - LCB). Results showed that significant decreases of CoP amplitude and velocity in both directions were accompanied by a significant decrease of lower chest breathing, and an increase of LCB frequency was seen during VF condition compared to control condition in both groups. Moreover, a significant decrease in tidal volume and increased breathing frequency during VF condition were confirmed by spirometric analysis. Reduced breathing movements and volumes as well as increased breathing frequency are probably part of an involuntary strategy activated to maximize balance improvement during VF condition. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Electrodeposition and electrochemical characterisation of thick and thin coatings of Sb and Sb/Sb{sub 2}O{sub 3} particles for Li-ion battery anodes

    Energy Technology Data Exchange (ETDEWEB)

    Bryngelsson, Hanna; Eskhult, Jonas; Edstroem, Kristina; Nyholm, Leif [Department of Materials Chemistry, The Aangstroem Laboratory, Uppsala University, P.O. Box 538, SE-751 21 Uppsala (Sweden)

    2007-12-20

    The possibilities to electrodeposit thick coatings composed of nanoparticles of Sb and Sb{sub 2}O{sub 3} for use as high-capacity anode materials in Li-ion batteries have been investigated. It is demonstrated that the stability of the coatings depends on their Sb{sub 2}O{sub 3} concentrations as well as microstructure. The electrodeposition reactions in electrolytes with different pH and buffer capacities were studied using chronopotentiometry and electrochemical quartz crystal microbalance measurements. The obtained deposits, which were characterised with XRD and SEM, were also tested as anode materials in Li-ion batteries. The influence of the pH and buffer capacity of the deposition solution on the composition and particle size of the deposits were studied and it is concluded that depositions from a poorly buffered solution of antimony-tartrate give rise to good anode materials due to the inclusion of precipitated Sb{sub 2}O{sub 3} nanoparticles in the Sb coatings. Depositions under conditions yielding pure Sb coatings give rise to deposits composed of large crystalline particles with poor anode stabilities. The presence of a plateau at about 0.8 V versus Li{sup +}/Li due to SEI forming reactions and the origin of another plateau at about 0.4 V versus Li{sup +}/Li seen during the lithiation of thin Sb coatings are also discussed. It is demonstrated that the 0.4 V plateau is present for Sb coatings for which the (0 1 2) peak is the main peak in the XRD diffractogram. (author)

  10. A new co-axial breathing system. A combination of the benefits of Mapleson A, D and E systems.

    Science.gov (United States)

    Burchett, K R; Bennett, J A

    1985-02-01

    A new, simple, versatile co-axial breathing system combining the features of Mapleson A, D and E type systems is described. The change from an A system to a D/E system is effected by a single switch and without reversal of the gas flow. Fresh gas flows in the order of 70 ml/kg/min are required for both spontaneous ventilation in the Mapleson A mode and controlled ventilation in the Mapleson D mode. The co-axial configuration offers the advantages of a single, lightweight breathing system with easy scavenging of anaesthetic gases, while the ability to switch between the A and D or E configurations offers the economic advantages of low fresh gas flows and the need for a single anaesthetic breathing system for all situations.

  11. New Insights into the Origins of Sb-Induced Effects on Self-Catalyzed GaAsSb Nanowire Arrays

    DEFF Research Database (Denmark)

    Ren, Dingding; Dheeraj, Dasa L.; Jin, Chengjun

    2016-01-01

    the development of high-performance nanowire devices based on such ternaries. Here, we report on the origins of Sb-induced effects affecting the morphology and crystal structure of self-catalyzed GaAsSb nanowire arrays. The, nanowire growth by molecular beam epitaxy is changed both kinetically...

  12. Void formation and structure change induced by heavy ion irradiation in GaSb and InSb

    International Nuclear Information System (INIS)

    Nitta, Noriko; Hasegawa, Tokiya; Yasuda, Hidehiro; Hayashi, Yoshihiko; Yoshiie, Toshimasa; Taniwaki, Masafumi; Mori, Hirotaro

    2010-01-01

    Void formation and structure change by heavy ion irradiation were investigated in GaSb and InSb thin films. The voids were formed after irradiation in both materials. The average diameter of the voids was about 15 nm in GaSb and 20 nm in InSb irradiated with 60 keV Sn + ions to a fluence of 0.25x10 18 ions/m 2 at room temperature. The void size in InSb is larger than that in GaSb. The large void size is quantitatively explained by the amount of induced vacancies obtained by the SRIM code simulation. The Debye-Scherrer rings were observed in the SAED patterns on both materials. The structure changes into a polycrystal by ion irradiation. Additionally, the 200 superlattice reflections in the [001] net pattern were almost absent, and the streak pattern along the direction was observed in InSb. It is considered that the anti phase domains of different lengths are formed by ion irradiation. Ion irradiation transforms the structure of InSb from chemical ordering to chemical disordering via the formation of anti phase boundaries. (author)

  13. Inverse population of spatially quantized levels in InAs/AlSb/GaSb 2D-systems

    International Nuclear Information System (INIS)

    Vasil'ev, Yu.B.; Suchalkin, S.D.

    1993-01-01

    Application possibilities of InAs/GaSb/AlSb-structures to obtain stimulated radiation at intersubband transitions within quantum hole, are analyzed. Numerical estimations of amplification coefficient and of relaxation times at intersubband transition within the magnetic field perpendicular at the structure surface, are presented. 15 refs.; 2 figs

  14. Air sampling unit for breath analyzers

    Science.gov (United States)

    Szabra, Dariusz; Prokopiuk, Artur; Mikołajczyk, Janusz; Ligor, Tomasz; Buszewski, Bogusław; Bielecki, Zbigniew

    2017-11-01

    The paper presents a portable breath sampling unit (BSU) for human breath analyzers. The developed unit can be used to probe air from the upper airway and alveolar for clinical and science studies. The BSU is able to operate as a patient interface device for most types of breath analyzers. Its main task is to separate and to collect the selected phases of the exhaled air. To monitor the so-called I, II, or III phase and to identify the airflow from the upper and lower parts of the human respiratory system, the unit performs measurements of the exhaled CO2 (ECO2) in the concentration range of 0%-20% (0-150 mm Hg). It can work in both on-line and off-line modes according to American Thoracic Society/European Respiratory Society standards. A Tedlar bag with a volume of 5 dm3 is mounted as a BSU sample container. This volume allows us to collect ca. 1-25 selected breath phases. At the user panel, each step of the unit operation is visualized by LED indicators. This helps us to regulate the natural breathing cycle of the patient. There is also an operator's panel to ensure monitoring and configuration setup of the unit parameters. The operation of the breath sampling unit was preliminarily verified using the gas chromatography/mass spectrometry (GC/MS) laboratory setup. At this setup, volatile organic compounds were extracted by solid phase microextraction. The tests were performed by the comparison of GC/MS signals from both exhaled nitric oxide and isoprene analyses for three breath phases. The functionality of the unit was proven because there was an observed increase in the signal level in the case of the III phase (approximately 40%). The described work made it possible to construct a prototype of a very efficient breath sampling unit dedicated to breath sample analyzers.

  15. Study of the vibrational modes of GaSb/AlSb (001 superlattices

    Directory of Open Access Journals (Sweden)

    D. Berdekas

    2009-01-01

    Full Text Available In the present work, we study the modes of vibration of small period (GaSbn/(AlSbn supelattices, n=1,2,3, grown along (001 direction. Any supelattice (SL is described by a three dimensional elementary cell several times bigger of the elementary cell of the zinc blend bulk constituents. The modes of vibration are calculated using a ten parameter (10 Valence Overlap Shell Model, with the interactions of the binaries GaSb and AlSb calculated with different parameter sets, for both short and long range forces. With the atomic displacements known, we calculated the Raman spectra, away of resonance conditions, based on the Bond Polarizability Model. Our results are in good agreement with the existing experimental data

  16. Bilateral spontaneous carotid artery dissection.

    Science.gov (United States)

    Townend, Bradley Scott; Traves, Laura; Crimmins, Denis

    2005-06-01

    Bilateral internal carotid artery dissections have been reported, but spontaneous bilateral dissections are rare. Internal carotid artery dissection can present with a spectrum of symptoms ranging from headache to completed stroke. Two cases of spontaneous bilateral carotid artery dissection are presented, one with headache and minimal symptoms and the other with a stroke syndrome. No cause could be found in either case, making the dissections completely spontaneous. Bilateral internal carotid artery dissection (ICAD) should be considered in young patients with unexplained head and neck pain with or without focal neurological symptoms and signs. The increasing availability of imaging would sustain the higher index of suspicion.

  17. Effect of different breathing aids on ventilation distribution in adults with cystic fibrosis.

    Directory of Open Access Journals (Sweden)

    Markus Wettstein

    Full Text Available BACKGROUND AND OBJECTIVES: We investigated the effect of different breathing aids on ventilation distribution in healthy adults and subjects with cystic fibrosis (CF. METHODS: In 11 healthy adults and 9 adults with CF electrical impedance tomography measurements were performed during spontaneous breathing, continuous positive airway pressure (CPAP and positive expiratory pressure (PEP therapy randomly applied in upright and lateral position. Spatial and temporal ventilation distribution was assessed. RESULTS: The proportion of ventilation directed to the dependent lung significantly increased in lateral position compared to upright in healthy and CF. This effect was enhanced with CPAP but neutralised with PEP, whereas the effect of PEP was larger in the healthy group. Temporal ventilation distribution showed exactly the opposite with homogenisation during CPAP and increased inhomogeneity with PEP. CONCLUSIONS: PEP shows distinct differences to CPAP with respect to its impact on ventilation distribution in healthy adults and CF subjects EIT might be used to individualise respiratory physiotherapy.

  18. Is breath acetone a biomarker of diabetes? A historical review on breath acetone measurements.

    Science.gov (United States)

    Wang, Zhennan; Wang, Chuji

    2013-09-01

    Since the ancient discovery of the 'sweet odor' in human breath gas, pursuits of the breath analysis-based disease diagnostics have never stopped. Actually, the 'smell' of the breath, as one of three key disease diagnostic techniques, has been used in Eastern-Medicine for more than three thousand years. With advancement of measuring technologies in sensitivity and selectivity, more specific breath gas species have been identified and established as a biomarker of a particular disease. Acetone is one of the breath gases and its concentration in exhaled breath can now be determined with high accuracy using various techniques and methods. With the worldwide prevalence of diabetes that is typically diagnosed through blood testing, human desire to achieve non-blood based diabetic diagnostics and monitoring has never been quenched. Questions, such as is breath acetone a biomarker of diabetes and how is the breath acetone related to the blood glucose (BG) level (the golden criterion currently used in clinic for diabetes diagnostic, monitoring, and management), remain to be answered. A majority of current research efforts in breath acetone measurements and its technology developments focus on addressing the first question. The effort to tackle the second question has begun recently. The earliest breath acetone measurement in clearly defined diabetic patients was reported more than 60 years ago. For more than a half-century, as reviewed in this paper, there have been more than 41 independent studies of breath acetone using various techniques and methods, and more than 3211 human subjects, including 1581 healthy people, 242 Type 1 diabetic patients, 384 Type 2 diabetic patients, 174 unspecified diabetic patients, and 830 non-diabetic patients or healthy subjects who are under various physiological conditions, have been used in the studies. The results of the breath acetone measurements collected in this review support that many conditions might cause changes to breath

  19. Crystal and magnetic study of the disordered perovskites Ca(Mn{sub 0.5}Sb{sub 0.5})O{sub 3} and Ca(Fe{sub 0.5}Sb{sub 0.5})O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Retuerto, M., E-mail: mretuerto@icmm.csic.es [Instituto de Ciencia de Materiales de Madrid, CSIC, Energia, Medio Ambiente y Tecnologias Sostenibles, Sor Juana Ines de la Cruz 3, Cantoblanco, E-28049 Madrid (Spain); Martinez-Lope, M.J.; Garcia-Hernandez, M. [Instituto de Ciencia de Materiales de Madrid, CSIC, Energia, Medio Ambiente y Tecnologias Sostenibles, Sor Juana Ines de la Cruz 3, Cantoblanco, E-28049 Madrid (Spain); Munoz, A. [Departamento de Fisica Aplicada, EPS, Universidad Carlos III, Avda. Universidad 30, E-28911 Leganes-Madrid (Spain); Fernandez-Diaz, M.T. [Institut Max Von Laue Paul Langevin, F-38042 Grenoble (France); Alonso, J.A. [Instituto de Ciencia de Materiales de Madrid, CSIC, Energia, Medio Ambiente y Tecnologias Sostenibles, Sor Juana Ines de la Cruz 3, Cantoblanco, E-28049 Madrid (Spain)

    2010-10-15

    We have investigated the double perovskites Ca{sub 2}MSbO{sub 6} (M = Mn, Fe) that have been prepared by solid-state reaction (M = Fe) and wet chemistry procedures (M = Mn). The crystal and magnetic structures have been studied from X-ray (XRD) and neutron powder diffraction (NPD) data. Rietveld refinements show that the crystal structures are orthorhombic (space group Pbnm) with complete disorder of M and Sb cations, so the formula should be rewritten as Ca(M{sub 0.5}Sb{sub 0.5})O{sub 3}. Due to this disorder no evidences of Jahn-Teller distortion can be observed in the MnO{sub 6} octahedra of Ca(Mn{sub 0.5}Sb{sub 0.5})O{sub 3}, in contrast with the ordered double perovskite Sr{sub 2}MnSbO{sub 6}. Ca(Fe{sub 0.5}Sb{sub 0.5})O{sub 3} behaves as an antiferromagnet with an ordered magnetic moment for Fe{sup 3+} of 1.53(4){mu}{sub B} and a propagation vector k = 0, as investigated by low-temperature NPD. The antiferromagnetic ordering is a result of the high degree of Fe/Sb anti-site disorder of the sample, which originates the spontaneous formation of Fe-rich islands, characterized by the presence of strong Fe-O-Fe antiferromagnetic couplings with enough long-range coherence to produce a magnetic contribution perceptible by NPD. By contrast, the magnetic structure of Ca(Mn{sub 0.5}Sb{sub 0.5})O{sub 3} cannot be observed by low-temperature NPD because the magnitude of the ordered magnetic moments is below the detection threshold for neutrons.

  20. Study for material analogs of FeSb2: Material design for thermoelectric materials

    Science.gov (United States)

    Kang, Chang-Jong; Kotliar, Gabriel

    2018-03-01

    Using the ab initio evolutionary algorithm (implemented in uspex) and electronic structure calculations we investigate the properties of a new thermoelectric material FeSbAs, which is a material analog of the enigmatic thermoelectric FeSb2. We utilize the density functional theory and the Gutzwiller method to check the energetics. We find that FeSbAs can be made thermodynamically stable above ˜30 GPa. We investigate the electronic structure and thermoelectric properties of FeSbAs based on the density functional theory and compare with those of FeSb2. Above 50 K, FeSbAs has higher Seebeck coefficients than FeSb2. Upon doping, the figure of merit becomes larger for FeSbAs than for FeSb2. Another material analog FeSbP, was also investigated, and found thermodynamically unstable even at very high pressure. Regarding FeSb2 as a member of a family of compounds (FeSb2, FeSbAs, and FeSbP) we elucidate what are the chemical handles that control the gaps in this series. We also investigate solubility (As or P for Sb in FeSb2) we found As to be more soluble. Finally, we study a two-band model for thermoelectric properties and find that the temperature dependent chemical potential and the presence of the ionized impurities are important to explain the extremum in the Seebeck coefficient exhibited in experiments for FeSb2.

  1. Noninvasive work of breathing improves prediction of post-extubation outcome.

    Science.gov (United States)

    Banner, Michael J; Euliano, Neil R; Martin, A Daniel; Al-Rawas, Nawar; Layon, A Joseph; Gabrielli, Andrea

    2012-02-01

    We hypothesized that non-invasively determined work of breathing per minute (WOB(N)/min) (esophageal balloon not required) may be useful for predicting extubation outcome, i.e., appropriate work of breathing values may be associated with extubation success, while inappropriately increased values may be associated with failure. Adult candidates for extubation were divided into a training set (n = 38) to determine threshold values of indices for assessing extubation and a prospective validation set (n = 59) to determine the predictive power of the threshold values for patients successfully extubated and those who failed extubation. All were evaluated for extubation during a spontaneous breathing trial (5 cmH(2)O pressure support ventilation, 5 cmH(2)O positive end expiratory pressure) using routine clinical practice standards. WOB(N)/min data were blinded to attending physicians. Area under the receiver operating characteristic curves (AUC), sensitivity, specificity, and positive and negative predictive values of all extubation indices were determined. AUC for WOB(N)/min was 0.96 and significantly greater (p indices. WOB(N)/min had a specificity of 0.83, the highest sensitivity at 0.96, positive predictive value at 0.84, and negative predictive value at 0.96 compared to all indices. For 95% of those successfully extubated, WOB(N)/min was ≤10 J/min. WOB(N)/min had the greatest overall predictive accuracy for extubation compared to traditional indices. WOB(N)/min warrants consideration for use in a complementary manner with spontaneous breathing pattern data for predicting extubation outcome.

  2. A mass balance model for the Mapleson D anaesthesia breathing system.

    Science.gov (United States)

    Lovich, M A; Simon, B A; Venegas, J G; Sims, N M; Cooper, J B

    1993-06-01

    A mathematical model is described which calculates the alveolar concentration of CO2(FACO2) in a patient breathing through a Mapleson D anaesthesia system. The model is derived using a series of mass balances for CO2 in the alveolar space, dead space, breathing system limb volume and reservoir. The variables included in the model are tidal volume (VT), respiratory rate, fresh gas flow rate (Vf), dead space volume, I:E ratio, and expiratory limb volume (Vl) time constant of lung expiration, and carbon dioxide production rate. The model predictions are compared with measurements made using a mechanical lung simulator in both spontaneous and controlled ventilation. Both the model and the experimental data predict that at high fresh gas flow rates and low respiratory rates, FACO2 is independent of Vf; at low fresh gas flow rates and high respiratory rates, FACO2 is independent of respiratory rate. The model and the data show that the VT influences FACO2, independent of minute ventilation alone, during both partial re-breathing and non-rebreathing operation. Therefore, describing the operation in terms of minute ventilation is ambiguous. It is also shown that Vl influences FACO2 such that, for any combination of patient and breathing-system variables, there is a Vl that minimizes the Vf required to maintain FACO2. In addition, expiratory resistance can increase the fresh gas flow rate required to maintain a given FACO2. The respiratory patterns observed with spontaneous and controlled ventilation are responsible for the difference in Vf required with each mode of ventilation.

  3. 42 CFR 84.141 - Breathing gas; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing gas; minimum requirements. 84.141 Section... Respirators § 84.141 Breathing gas; minimum requirements. (a) Breathing gas used to supply supplied-air respirators shall be respirable breathing air and contain no less than 19.5 volume-percent of oxygen. (b...

  4. 14 CFR 25.1439 - Protective breathing equipment.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Protective breathing equipment. 25.1439... Protective breathing equipment. (a) Fixed (stationary, or built in) protective breathing equipment must be installed for the use of the flightcrew, and at least one portable protective breathing equipment shall be...

  5. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation airflow will be measured in the facepiece or mouthpiece while the apparatus is operated by a breathing...

  6. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation...-circuit apparatus with a breathing machine as described in § 84.88, and the exhalation resistance shall...

  7. 42 CFR 84.88 - Breathing bag test.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing bag test. 84.88 Section 84.88 Public... RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.88 Breathing bag test. (a) Breathing bags will be tested in an air atmosphere saturated with...

  8. 14 CFR 121.337 - Protective breathing equipment.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Protective breathing equipment. 121.337... Protective breathing equipment. (a) The certificate holder shall furnish approved protective breathing equipment (PBE) meeting the equipment, breathing gas, and communication requirements contained in paragraph...

  9. 21 CFR 868.5270 - Breathing system heater.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breathing system heater. 868.5270 Section 868.5270...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5270 Breathing system heater. (a) Identification. A breathing system heater is a device that is intended to warm breathing gases before they enter...

  10. Unusual crystallization behavior in Ga-Sb phase change alloys

    Directory of Open Access Journals (Sweden)

    Magali Putero

    2013-12-01

    Full Text Available Combined in situ X-ray scattering techniques using synchrotron radiation were applied to investigate the crystallization behavior of Sb-rich Ga-Sb alloys. Measurements of the sheet resistance during heating indicated a reduced crystallization temperature with increased Sb content, which was confirmed by in situ X-ray diffraction. The electrical contrast increased with increasing Sb content and the resistivities in both the amorphous and crystalline phases decreased. It was found that by tuning the composition between Ga:Sb = 9:91 (in at.% and Ga:Sb = 45:55, the change in mass density upon crystallization changes from an increase in mass density which is typical for most phase change materials to a decrease in mass density. At the composition of Ga:Sb = 30:70, no mass density change is observed which should be very beneficial for phase change random access memory (PCRAM applications where a change in mass density during cycling is assumed to cause void formation and PCRAM device failure.

  11. Spontaneous intraorbital hematoma: case report

    Directory of Open Access Journals (Sweden)

    Vinodan Paramanathan

    2010-12-01

    Full Text Available Vinodan Paramanathan, Ardalan ZolnourianQueen's Hospital NHS Foundation Trust, Burton on Trent, Staffordshire DE13 0RB, UKAbstract: Spontaneous intraorbital hematoma is an uncommon clinical entity seen in ophthalmology practice. It is poorly represented in the literature. Current evidence attributes it to orbital trauma, neoplasm, vascular malformations, acute sinusitis, and systemic abnormalities. A 65-year-old female presented with spontaneous intraorbital hematoma manifesting as severe ocular pains, eyelid edema, proptosis, and diplopia, without a history of trauma. Computer tomography demonstrated a fairly well defined extraconal lesion with opacification of the paranasal sinuses. The principal differential based on all findings was that of a spreading sinus infection and an extraconal tumor. An unprecedented finding of a spontaneous orbital hematoma was discovered when the patient was taken to theater. We discuss the rarity of this condition and its management.Keywords: hemorrhage, ophthalmology, spontaneous, intra-orbital, hematoma

  12. Analysis for drugs in saliva and breath

    Science.gov (United States)

    1981-09-25

    Collection devices for saliva and breath that involved non-invasive techniques for sample collection were evaluated. Having subjects simply spit into a specially prepared glass vial was found to be an efficient, inexpensive and simple way to collect ...

  13. Analysis for drug in saliva and breath

    Science.gov (United States)

    1981-09-25

    Collection devices for saliva and breath that involved non-invasive : techniques for sample collection were evaluated. Having subjects simply : spit into a specially prepared glass vial was found to be an efficient, : inexpensive and simple way to co...

  14. Healthy Living: Helping Your Child Breathe Easier

    Science.gov (United States)

    ... Breathe Easier Font: Aerosol Delivery Oxygen Resources Immunizations Pollution Nutrition Exercise Coming Of Age Older Adults Allergy ... through these narrowed airways can produce a wheezing sound. Other forms the allergy may take are sneezing, ...

  15. Breath-holding spells in infants.

    Science.gov (United States)

    Goldman, Ran D

    2015-02-01

    I have children in my clinic who experience seizurelike episodes in which they cry and hold their breath to the point of cyanosis and loss of consciousness. Their examination or investigation findings are normal and referral to a pediatric specialist results in no further investigation. Are breath-holding spells common, and what type of investigation is needed? A breath-holding spell is a benign paroxysmal nonepileptic disorder occurring in healthy children 6 to 48 months of age. The episodes start with a provocation such as emotional upset or minor injury, and might progress to breath holding, cyanosis, and syncope. The episodes are extremely frightening to watch but have benign consequences. Once a clinical diagnosis is made, it is recommended to conduct an electrocardiogram and to rule out anemia, but no further investigation or referral is warranted. Copyright© the College of Family Physicians of Canada.

  16. Humidifiers: Air Moisture Eases Skin, Breathing Symptoms

    Science.gov (United States)

    Humidifiers: Air moisture eases skin, breathing symptoms Humidifiers can ease problems caused by dry air. But they need regular maintenance. Here ... that emit water vapor or steam to increase moisture levels in the air (humidity). There are several ...

  17. Alcohol breath test: gas exchange issues.

    Science.gov (United States)

    Hlastala, Michael P; Anderson, Joseph C

    2016-08-01

    The alcohol breath test is reviewed with a focus on gas exchange factors affecting its accuracy. The basis of the alcohol breath test is the assumption that alveolar air reaches the mouth during exhalation with no change in alcohol concentration. Recent investigations have shown that alcohol concentration is altered during its transit to the mouth. The exhaled alcohol concentration is modified by interaction with the mucosa of the pulmonary airways. Exhaled alcohol concentration is not an accurate indicator of alveolar alcohol concentration. Measuring alcohol concentration in the breath is very different process than measuring a blood level from air equilibrated with a blood sample. Airway exchange of alcohol leads to a bias against certain individuals depending on the anatomic and physiologic characteristics. Methodological modifications are proposed to improve the accuracy of the alcohol breath test to become fair to all. Copyright © 2016 the American Physiological Society.

  18. Seeking Allergy Relief: When Breathing Becomes Bothersome

    Science.gov (United States)

    ... Issues Subscribe June 2016 Print this issue Seeking Allergy Relief When Breathing Becomes Bothersome En español Send ... Preschoolers Benefit from Peanut Allergy Therapy Wise Choices Allergy Symptoms Runny or stuffy nose Sneezing Itchy nose, ...

  19. Atmospheric Breathing Electric Thruster for Planetary Exploration

    Data.gov (United States)

    National Aeronautics and Space Administration — This study will investigate the development of an atmosphere-breathing electric propulsion solar-powered vehicle to explore planets such as Mars. The vehicle would...

  20. Structural and optical properties of GaSb films grown on AlSb/Si (100) by insertion of a thin GaSb interlayer grown at a low temperature

    International Nuclear Information System (INIS)

    Noh, Young Kyun; Kim, Moon Deock; Oh, Jae Eung; Yang, Woo Chul

    2010-01-01

    We have investigated the structural and the optical properties of GaSb films with a thin AlSb buffer layer and a GaSb interlayer grown on Si (100) substrates by using molecular beam epitaxy. Reflection high-energy electron diffraction and atomic force microscopy measurements of the thin AlSb buffer layers showed that the surface had uniformly-sized quantum dots with a low defect density. The surface roughness of a GaSb film with a thin GaSb interlayer grown at a low temperature was decreased by a factor of about 5 compared with the roughness of the GaSb film without the thin GaSb interlayer. In addition, double-crystal X-ray diffraction and photoluminescence results showed that the structural and the optical properties of the GaSb layer with the GaSb interlayer were improved significantly. We suggest that the significant reduction of the dislocation density in the GaSb film was due to the dislocations being prevented from propagating into the GaSb overlayer by the thin GaSb interlayer.

  1. Comparison of work of breathing using drawover and continuous flow anaesthetic breathing systems in children.

    Science.gov (United States)

    Bell, G T; McEwen, J P J; Beaton, S J; Young, D

    2007-04-01

    We compared the work of breathing under general anaesthesia in children using drawover and continuous flow anaesthetic systems. A pilot study was conducted in four children weighing > 20 kg in whom it would usually be considered appropriate to use breathing systems designed for adult anaesthesia. The pilot study compared work of breathing using the Mapleson D breathing system and the Triservice Anaesthetic Apparatus (TSAA). Work of breathing was calculated using the modified Campbell technique that calculates work using a pressure volume loop derived from oesophageal pressure and airway gas volume measurements. We found no difference in the work of breathing when comparing the Mapleson D and the TSAA in children > 20 kg. Following completion of the pilot study, we conducted a study on 10 children weighing between 10 and 20 kg comparing work of breathing using the Mapleson F breathing system and the TSAA. We found no significant difference in the work of breathing between the Mapleson F and the TSAA for these children. The TSAA can therefore be recommended for use down to a lower weight limit of 10 kg.

  2. Spontaneous ischaemic stroke in dogs

    DEFF Research Database (Denmark)

    Gredal, Hanne Birgit; Skerritt, G. C.; Gideon, P.

    2013-01-01

    Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms.......Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms....

  3. Spontaneity and international marketing performance

    OpenAIRE

    Souchon, Anne L.; Hughes, Paul; Farrell, Andrew M.; Nemkova, Ekaterina; Oliveira, Joao S.

    2016-01-01

    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Purpose – The purpose of this paper is to ascertain how today’s international marketers can perform better on the global scene by harnessing spontaneity. Design/methodology/approach – The authors draw on contingency theory to develop a model of the spontaneity – international marketing performance relationship, and identify three potential m...

  4. High Performance InGaAsSb TPV Cells

    Energy Technology Data Exchange (ETDEWEB)

    ZA Shellengarger; GC Taylor; RU Martinelli; JM Carpinelli

    2004-06-09

    Lattice-matched 0.52 eV InGaAsSb/GaSb thermophotovoltaic (TPV) cells are grown using a multi-wafer metal-organic-chemical-vapor-deposition (MOCVD) system. MOCVD growth series of P/N junction epitaxial structures consisting of as many as 30 wafers demonstrate good run-to-run reproducibility, good uniformity across the wafer and exhibit high performance with open circuit voltages of {approx}300mV and fill factors of 70% at 25 C. Growth parameters, including temperature, surface preparation and substrate orientation, that directly affect growth have been optimized for the active 0.52 eV InGaAsSb region and GaSb confinement layers. Focus is on increasing TPV diode performance through architectural improvements, specifically by reducing the minority carrier recombination velocity at the emitter and base front and back interfaces. Work in support of incorporating a back surface reflector (BSR) including the growth of N/P diode architectures and the addition of a lattice-matched InAsSb etch stop layer for substrate removal and wafer bonding, is reported. The lattice matched InAsSb stop etch exhibits resiliency to the substrate removal and wafer bonding processes. Substantial improvement in carrier lifetime on test structures with P-type AlGaAsSb layers indicated incorporation of these layers into the TPV cell structure should provide significant improvement in open-circuit voltage. Addition of AlGaAsSb confinement layers to the standard P/N cell structure gave some of the best InGaAsSb TPV cell results to date.

  5. Long-term monitoring of breath methane.

    Science.gov (United States)

    Polag, Daniela; Keppler, Frank

    2018-05-15

    In recent years, methane as a component of exhaled human breath has been considered as a potential bioindicator providing information on microbial activity in the intestinal tract. Several studies indicated a relationship between breath methane status and specific gastrointestinal disease. So far, almost no attention has been given to the temporal variability of breath methane production by individual persons. Thus here, for the first time, long-term monitoring was carried out measuring breath methane of three volunteers over periods between 196 and 1002days. Results were evaluated taking into consideration the health status and specific medical intervention events for each individual during the monitoring period, and included a gastroscopy procedure, a vaccination, a dietary change, and chelate therapy. As a major outcome, breath methane mixing ratios show considerable variability within a person-specific range of values. Interestingly, decreased breath methane production often coincided with gastrointestinal complaints whereas influenza infections were mostly accompanied by increased breath methane production. A gastroscopic examination as well as a change to a low-fructose diet led to a dramatic shift of methane mixing ratios from high to low methane production. In contrast, a typhus vaccination as well as single chelate injections resulted in significant short-term methane peaks. Thus, this study clearly shows that humans can change from high to low methane emitters and vice versa within relatively short time periods. In the case of low to medium methane emitters the increase observed in methane mixing ratios, likely resulting from immune reactions and inflammatory processes, might indicate non-microbial methane formation under aerobic conditions. Although detailed reaction pathways are not yet known, aerobic methane formation might be related to cellular oxidative-reductive stress reactions. However, a detailed understanding of the pathways involved in human

  6. Quaternary InGaAsSb Thermophotovoltaic Diode Technology

    International Nuclear Information System (INIS)

    M Dashiell; J Beausang; H Ehsani; G Nichols; D DePoy; L Danielson; P Talamo; K Rahner; E Brown; S Burger; P Fourspring; W Topper; P Baldasaro; C Wang; R Huang; M Connors; G Turner; Z Shellenbarger; G Taylor; Jizhong Li; R Martinelli; D Donetski; S Anikeev; G Belenky; S Luryl

    2005-01-01

    Thermophotovoltaic (TPV) diodes fabricated from InGaAsSb alloys lattice-matched to GaSb substrates are grown by Metal Organic Vapor Phase Epitaxy (MOVPE). 0.53eV InGaAsSb TPV diodes utilizing front-surface spectral control filters have been tested in a vacuum cavity and a TPV thermal-to-electric conversion efficiency (η TPV ) and a power density (PD) of η TPV = 19% and PD=0.58 W/cm 2 were measured for T radiator = 950 C and T diode = 27 C. Recombination coefficients deduced from minority carrier measurements and the theory reviewed in this article predict a practical limit to the maximum achievable conversion efficiency and power density for 0.53eV InGaAsSb TPV. The limits for the above operating temperatures are projected to be η TPV = 26% and PD = 0.75 W/cm 2 . These limits are extended to η TPV = 30% and PD = 0.85W/cm 2 if the diode active region is bounded by a reflective back surface to enable photon recycling and a two-pass optical path length. The internal quantum efficiency of the InGaAsSb TPV diode is close to the theoretically predicted limits, with the exception of short wavelength absorption in GaSb contact layers. Experiments show that the open circuit voltage of the 0.53eV InGaAsSb TPV diodes is not strongly dependent on the device architectures studied in this work where both N/P and P/N double heterostructure diodes have been grown with various acceptor and donor doping levels, having GaSb and AlGaAsSb confinement, and also partial back surface reflectors. Lattice matched InGaAsSb TPV diodes were fabricated with bandgaps ranging from 0.6 to 0.5eV without significant degradation of the open circuit voltage factor, quantum efficiency, or fill factor as the composition approached the miscibility gap. The key diode performance parameter which is limiting efficiency and power density below the theoretical limits in InGaAsSb TPV devices is the open circuit voltage. The open circuit voltages of state-of-the-art 0.53eV InGaAsSb TPV diode are ∼10

  7. Cu doped AlSb polycrystalline thin films

    International Nuclear Information System (INIS)

    Wu Lili; Jin Shuo; Zeng Guanggen; Zhang Jingquan; Li Wei; Feng Lianghuan; Li Bing; Wang Wenwu

    2013-01-01

    Cu-doped AlSb polycrystalline films were grown on quartz glass by magnetron co-sputtering. The structural, morphological and electrical properties of the films were studied. The incorporation of copper atoms can result in the increase of lattice constants, and annealing is helpful to eliminate this deformation. Cu-doped AlSb films exhibit weak n-type conductivity. The results show that the doping effect has a close relationship with the annealing process, meaning that the position of Cu atom in AlSb polycrystalline films might influence the doping effect. (semiconductor materials)

  8. Swimming in air-breathing fishes.

    Science.gov (United States)

    Lefevre, S; Domenici, P; McKenzie, D J

    2014-03-01

    Fishes with bimodal respiration differ in the extent of their reliance on air breathing to support aerobic metabolism, which is reflected in their lifestyles and ecologies. Many freshwater species undertake seasonal and reproductive migrations that presumably involve sustained aerobic exercise. In the six species studied to date, aerobic exercise in swim flumes stimulated air-breathing behaviour, and there is evidence that surfacing frequency and oxygen uptake from air show an exponential increase with increasing swimming speed. In some species, this was associated with an increase in the proportion of aerobic metabolism met by aerial respiration, while in others the proportion remained relatively constant. The ecological significance of anaerobic swimming activities, such as sprinting and fast-start manoeuvres during predator-prey interactions, has been little studied in air-breathing fishes. Some species practise air breathing during recovery itself, while others prefer to increase aquatic respiration, possibly to promote branchial ion exchange to restore acid-base balance, and to remain quiescent and avoid being visible to predators. Overall, the diversity of air-breathing fishes is reflected in their swimming physiology as well, and further research is needed to increase the understanding of the differences and the mechanisms through which air breathing is controlled and used during exercise. © 2014 The Fisheries Society of the British Isles.

  9. Periodic breathing and apnea in preterm infants.

    Science.gov (United States)

    Barrington, K J; Finer, N N

    1990-02-01

    The relationship between periodic breathing and idiopathic apnea of prematurity was investigated. We recorded respiratory impedance, heart rate, pulse oximetry and end-tidal CO2 from 68 untreated infants of less than or equal to 34 wk gestation with a diagnosis of idiopathic apnea of prematurity. Mean birth wt was 1476 g (SD 420) and mean gestational age was 29.9 wk (SD 2.6). Apneas of more than 15 s duration that were associated with hypoxemia or bradycardia were identified by semiautomated analysis of computerized records. A total of 1116 significant apneic spells were identified, only one of which occurred during an epoch of periodic breathing, five others occurred within 2 min of the end of an epoch of periodic breathing. Less than 0.6% of significant apneic spells occur within 2 min of periodic breathing. In all of the 12 infants that were monitored starting in the first 12 h of life, significant apneic spells were identified before 36 h of age and no precipitating factors were identified. Periodic breathing did not occur during the first 48 h of life, a finding that supports the concept that the peripheral chemoreceptor is inactive in the first 48 h of life. Periodic breathing in the premature infant is not a precursor to significant apnea.

  10. Optoacoustic 13C-breath test analyzer

    Science.gov (United States)

    Harde, Hermann; Helmrich, Günther; Wolff, Marcus

    2010-02-01

    The composition and concentration of exhaled volatile gases reflects the physical ability of a patient. Therefore, a breath analysis allows to recognize an infectious disease in an organ or even to identify a tumor. One of the most prominent breath tests is the 13C-urea-breath test, applied to ascertain the presence of the bacterium helicobacter pylori in the stomach wall as an indication of a gastric ulcer. In this contribution we present a new optical analyzer that employs a compact and simple set-up based on photoacoustic spectroscopy. It consists of two identical photoacoustic cells containing two breath samples, one taken before and one after capturing an isotope-marked substrate, where the most common isotope 12C is replaced to a large extent by 13C. The analyzer measures simultaneously the relative CO2 isotopologue concentrations in both samples by exciting the molecules on specially selected absorption lines with a semiconductor laser operating at a wavelength of 2.744 μm. For a reliable diagnosis changes of the 13CO2 concentration of 1% in the exhaled breath have to be detected at a concentration level of this isotope in the breath of about 500 ppm.

  11. Growth and Optimization of 2 Micrometers InGaSb/AlGaSb Quantum-Well-Based VECSELs on GaAs/AlGaAs DBRs

    Science.gov (United States)

    2013-08-01

    active region consists of nine In0.2Ga0.8Sb QWs separated by pump absorbing Al0.25Ga0.75 Sb barriers. An AlSb confinement layer on each side of the...by pump absorbing Al0.25Ga0.75Sb barriers and AlSb top/bottom clad. The key feature of the antimonide VECSEL based on the GaAs/AlGaAs DBRs is the...also enhanced by the AlSb carrier con- finement layers. However, the “ABC” empirical model is not adequate to model the carrier losses at high carrier

  12. Reactive ion etching of GaSb, (Al,Ga)Sb, and InAs for novel device applications

    International Nuclear Information System (INIS)

    LaTulipe, D.C.; Frank, D.J.; Munekata, H.

    1991-01-01

    Although a variety of novel device proposals for GaSb/(Al,Ga)Sb/InAs heterostructures have been made, relatively little is known about processing these materials. The authors of this paper have studied the reactive ion etching characteristics of GaSb, (Al,Ga)Sb, and InAs in both methane/hydrogen and chlorine gas chemistries. At conditions similar to those reported elsewhere for RIE of InP and GaAs in CH 4 /H 2 , the etch rate of (Al,Ga)Sb was found to be near zero, while GaSb and InAs etched at 200 Angstrom/minute. Under conditions where the etch mechanism is primarily physical sputtering, the three compounds etch at similar rates. Etching in Cl 2 was found to yield anistropic profiles, with the etch rate of (Al,Ga)Sb increasing with Al mole fraction, while InAs remains unetched. Damage to the InAs stop layer was investigated by sheet resistance and mobility measurements. These etching techniques were used to fabricate a novel InAs- channel FET composed of these materials. Several scanning electron micrographs of etching results are shown along with preliminary electrical characteristics

  13. Formation Mechanism of Self Assembled Horizontal ErSb Nanowires Embedded in a GaSb(001) Matrix

    Science.gov (United States)

    Wilson, Nathaniel; Kraemer, Stephan; PalmstrøM, Chris

    The ErxGa1-xSb exhibits a variety of self-assembling nanostructures. In order to harness these nanostructures for use in devices and other material systems it is important to understand their formation. We have characterized the growth mechanism of self-assembled horizontal ErSb nanowires in a GaSb(001) matrix through the use of in-situ Scanning Tunneling Microscopy (STM) as well as ex-situ Transmission Electron Microscopy (TEM). We observe large GaSb macrosteps on the growth surface of Er.3Ga.7Sb samples. The areas near the ledge and base of the macrosteps show significant differences in size and distribution of ErSb nanowires. Results suggest that the formation of macrosteps drives the transition from vertical to horizontal nanowires in the ErxGa1-xSb system. We also observe a low temperature growth mode, which results in horizontal nanowire formation under a wide range of flux conditions. This new growth mode does not exhibit the embedded growth observed in the formation of nanowires at higher temperatures and may allow for horizontal nanowire formation without the presence of macrosteps, as well as the formation of smaller nanoparticles which may be useful for achieving smaller nanoparticle dimensions and electron confinement effects. This work was supported by NSF-DMR under 1507875.

  14. Investigations on MnSb and related compounds with b8-type structures

    NARCIS (Netherlands)

    Bouwma, Jakob

    1972-01-01

    This thesis describes investigations on phases with hexagonal B8-type structures in the systems Mn-Sb-Sn, Mn-Sb-Te, Mn-Cr-Sb and Mn-V-Sb. In -chapter 1 some general remarks are made on compounds with B8-type structures. The preparation of the samples, and the X-ray crystallographic investigations

  15. Effect of Continuous Promedol Infusion on Recovery of Spontaneous Breathing in Children in the Postoperative Period

    Directory of Open Access Journals (Sweden)

    E. V. Zilbert

    2011-01-01

    Full Text Available Objective: to study the impact of correcting immune disorders on the course of the disease in patients with abdominal sepsis. Subjects and methods. Ninety-five patients with abdominal sepsis were examined. APACHE III scores were 25—30. Humoral and cellular immunological parameters were studied in all the patients. The immunotropic drug Galavit was included into the combination treatment of 42 patients. Results. An immunodeficiency state was found in 74 (80% patients. The incorporation of targeted immunotherapy into the package of medical measures activated the immune system of patients and, in a number of cases, could elevate the level of T lymphocytes, reduced the rate of laparostomy wound suppurations by 1.9 times and the number of fatal outcomes by 10.1%. Conclusion. Incorporation of targeted immunotherapy into the package of medical measures activates cellular immunity and tissue regeneration processes and reduces the degree of endogenous intoxication, the rate of laparostomy wound suppurations, and the number of fatal outcomes. Key words: abdominal sepsis, immunomodulation, Galavit.

  16. [Weaning from prolonged mechanical ventilation at 72 hours of spontaneous breathing].

    Science.gov (United States)

    Villalba, Darío; Plotnikow, Gustavo; Feld, Viviana; Rivero Vairo, Noelia; Scapellato, José; Díaz Nielsen, Ernesto

    2015-01-01

    The aim of this study was to describe the population admitted to a weaning center (WC) to receive invasive mechanical ventilation (MV), analyze their evolution and identify weaning failure predictors. The medical records of 763 patients admitted to the respiratory care service in the period between May 2005 and January 2012 were reviewed; 372 were selected among 415 tracheotomized and mechanically ventilated. Different variables were analyzed as weaning failure predictors. The mean age of patients admitted was 69 years (SD 14.7), 57% were men. The median length of hospitalization in ICU was 33 days (IQR 26-46). Admission to ICU was due to medical causes in 86% of cases. During hospitalization in WC 186 (50%) patients achieved the successful weaning at a median of 13 days (interquartile range-IQR 5-38). A predictor of weaning failure was age. When we studied the subpopulation with partial disconnection of mechanical ventilation, we found a history of COPD and ageas predictors. Although 25% of the patients died, or required referral to a center of major complexity before 2 weeks of hospitalization, more than half of the patients were able to be removed permanently from the invasive mechanical ventilation (MV), this could support the care of chronic critical patients in MV and rehabilitation centers in Argentina because patients in these centers have a chance of weaning from MV, despite the high chances of developing complications.

  17. The Influence of the Thymine C5 Methyl Group on Spontaneous Base Pair Breathing in DNA

    Czech Academy of Sciences Publication Activity Database

    Wärmländer, S.; Šponer, Jiří; Leijon, M.; Šponer, Judit E.

    2002-01-01

    Roč. 277, č. 32 (2002), s. 28491-28497 ISSN 0021-9258 R&D Projects: GA MŠk LN00A016 Institutional research plan: CEZ:AV0Z4040901 Keywords : thymine * DNA * base pairs Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.696, year: 2002

  18. Synthesis, crystal structures, and physical properties of the new Zintl phases A21Zn4Pn18 (A=Ca, Eu; Pn=As, Sb)-Versatile arrangements of [ZnPn4] tetrahedra

    Science.gov (United States)

    Suen, Nian-Tzu; Wang, Yi; Bobev, Svilen

    2015-07-01

    Four new Zintl phases, Ca21Zn4As18, Ca21Zn4Sb18, Eu21Zn4As18 and Eu21Zn4Sb18 have been synthesized by metal flux reactions. Their structures have been established from single-crystal X-ray diffraction. Despite the similar chemical makeup and the identical formulae, the structures of the four compounds are not the same-Ca21Zn4As18, Ca21Zn4Sb18 and Eu21Zn4As18 crystallize in the monoclinic space group C2/m (No. 12, Z=4) with the β-Ca21Mn4Sb18 structure type, while Eu21Zn4Sb18 adopts the Ba21Cd4Sb18 structure type with the orthorhombic space group Cmce (No. 64, Z=8). Both structures are based on ZnAs4 or ZnSb4 tetrahedra, linked in slightly different ways, and Ca2+ and Eu2+ cations that fill the space between them. The structural relationships between the title compounds and other known ternary phases with intricate structures are discussed. Electrical resistivity measurement on single-crystalline Eu21Zn4Sb18 suggests an intrinsic semiconductor behavior with a band gap of ca. 0.2 eV. The temperature dependent DC magnetization measurement on the same material indicates Curie-Weiss paramagnetism in the high-temperature regime, and a spontaneous antiferromagnetic ordering below 8 K. The calculated effective moments of Eu confirm the divalent Eu2+ ground state, as expected from the Zintl-Klemm concept.

  19. In vivo proton MRS of normal pancreas metabolites during breath-holding and free-breathing

    International Nuclear Information System (INIS)

    Su, T.-H.; Jin, E.-H.; Shen, H.; Zhang, Y.; He, W.

    2012-01-01

    Aim: To characterize normal pancreas metabolites using in vivo proton magnetic resonance spectroscopy ( 1 H MRS) at 3 T under conditions of breath-holding and free-breathing. Materials and methods: The pancreases of 32 healthy volunteers were examined using 1 H MRS during breath-holding and free-breathing acquisitions in a single-voxel point-resolved selective spectroscopy sequence (PRESS) technique using a 3 T MRI system. Resonances were compared between paired spectra of the two breathing modes. Furthermore, correlations between lipid (Lip) content and age, body-mass index (BMI), as well as choline (Cho) peak visibility of the normal pancreas were analysed during breath-holding. Results: Twenty-nine pairs of spectra were successfully obtained showing three major resonances, Lip, Cho, cholesterol and the unsaturated parts of the olefinic region of fatty acids (Chol + Unsat). Breath-hold spectra were generally better, with higher signal-to-noise ratios (SNR; Z=–2.646, p = 0.008) and Cho peak visible status (Z=–2.449, p = 0.014). Correlations were significant between spectra acquired by the two breathing modes, especially for Lip height, Lip area, and the area of other peaks at 1.9–4.1 ppm. However, the Lip resonance was significantly different between the spectra of the two breathing modes (p 1 H MRS of the normal pancreas at 3 T is technically feasible and can characterize several metabolites. 1 H MRS during breath-holding acquisition is superior to that during free-breathing acquisition.

  20. Increasing the thermoelectric power factor of Ge17Sb2Te20 by adjusting the Ge/Sb ratio

    Science.gov (United States)

    Williams, Jared B.; Mather, Spencer P.; Page, Alexander; Uher, Ctirad; Morelli, Donald T.

    2017-07-01

    We have investigated the thermoelectric properties of Ge17Sb2Te20. This compound is a known phase change material with electronic properties that depend strongly on temperature. The thermoelectric properties of this compound can be tuned by altering the stoichiometry of Ge and Sb without the use of additional foreign elements during synthesis. This tuning results in a 26% increase in the thermoelectric power factor at 723 K. Based on a single parabolic band model we show that the pristine material is optimally doped, and thus, a reduction in the lattice thermal conductivity of pure Ge17Sb2Te20 should result in an enhanced thermoelectric figure of merit.

  1. Effect of subband nonparabolicity on optical properties of InSbAs/AlSb deep quantum well heterostructures

    International Nuclear Information System (INIS)

    Pavlov, N V; Zegrya, G G

    2015-01-01

    Optical properties of heterostructures with deep quantum wells have been studied in the framework of four-band Kane mode permitting a nonparabolic energy spectrum of charge carriers to be taken into account. The system AlSb/InAs 0.84 Sb 0.16 /AlSb was used as an example. It is established that the nonparabolicity weakly influences the overlap integral between s- and p-states, but notably increase the state density and optical absorption coefficient in the conduction band. (paper)

  2. Role of parafacial nuclei in control of breathing in adult rats.

    Science.gov (United States)

    Huckstepp, Robert T R; Cardoza, Kathryn P; Henderson, Lauren E; Feldman, Jack L

    2015-01-21

    Contiguous brain regions associated with a given behavior are increasingly being divided into subregions associated with distinct aspects of that behavior. Using recently developed neuronal hyperpolarizing technologies, we functionally dissect the parafacial region in the medulla, which contains key elements of the central pattern generator for breathing that are important in central CO2-chemoreception and for gating active expiration. By transfecting different populations of neighboring neurons with allatostatin or HM4D Gi/o-coupled receptors, we analyzed the effect of their hyperpolarization on respiration in spontaneously breathing vagotomized urethane-anesthetized rats. We identify two functionally separate parafacial nuclei: ventral (pFV) and lateral (pFL). Disinhibition of the pFL with bicuculline and strychnine led to active expiration. Hyperpolarizing pFL neurons had no effect on breathing at rest, or changes in inspiratory activity induced by hypoxia and hypercapnia; however, hyperpolarizing pFL neurons attenuated active expiration when it was induced by hypercapnia, hypoxia, or disinhibition of the pFL. In contrast, hyperpolarizing pFV neurons affected breathing at rest by decreasing inspiratory-related activity, attenuating the hypoxia- and hypercapnia-induced increase in inspiratory activity, and when present, reducing expiratory-related abdominal activity. Together with previous observations, we conclude that the pFV provides a generic excitatory drive to breathe, even at rest, whereas the pFL is a conditional oscillator quiet at rest that, when activated, e.g., during exercise, drives active expiration. Copyright © 2015 the authors 0270-6474/15/351052-16$15.00/0.

  3. Effect of AlSb buffer layer thickness on heteroepitaxial growth of InSb films on a Si(001) substrate

    Energy Technology Data Exchange (ETDEWEB)

    Mori, M. [Nano and Functional Material Sciences, Graduate School of Science and Engineering, University of TOYAMA, Gofuku 3190, Toyama 930-8555 (Japan)], E-mail: morimasa@eng.u-toyama.ac.jp; Murata, K.; Fujimoto, N.; Tatsuyama, C.; Tambo, T. [Nano and Functional Material Sciences, Graduate School of Science and Engineering, University of TOYAMA, Gofuku 3190, Toyama 930-8555 (Japan)

    2007-07-31

    Aluminum antimonide (AlSb) layers with various thickness ranged from about 8 to 250 nm were grown at 520 deg. C as the buffer layer for the heteroepitaxial growth of InSb films on Si(001) substrates. InSb films were grown at 400 deg. C on the AlSb/Si(001), and were characterized by X-ray diffraction (XRD), atomic force microscope, as a function of the thickness of the AlSb layer. The XRD patterns of the InSb films grown on the AlSb layers show that even if the AlSb buffer layer, whose surface consists of many islands, is as thin as 8 nm, it is effective for the heteroepitaxial growth of InSb film on a Si(001) substrate, and the AlSb layer of about 40 nm is thick enough to grow heteroepitaxial InSb films on the Si(001) substrate. The results of the {phi} scan patterns of the films show that InSb films on a Si(001) substrate with AlSb buffer layer were heteroepitaxially grown without any rotation in the growth plane.

  4. Sb{sub 7}Te{sub 3}/ZnSb multilayer thin films for high thermal stability and long data retention phase-change memory

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shiyu; Wu, Weihua [Functional Materials Research Laboratory, School of Materials Science & Engineering, Tongji University, Shanghai 201804 (China); Zhai, Jiwei, E-mail: apzhai@tongji.edu.cn [Functional Materials Research Laboratory, School of Materials Science & Engineering, Tongji University, Shanghai 201804 (China); Song, Sannian; Song, Zhitang [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Science, Shanghai 200050 (China)

    2017-04-15

    Highlights: • Sb{sub 7}Te{sub 3} (ST) provides a fast crystallization speed, low melting temperature. • The Sb{sub 7}Te{sub 3}/ZnSb films exhibits faster crystallization speed, high thermal stability. • The calculated temperature for 10-year data retention is about 127 {sup o}C. • The Sb{sub 7}Te{sub 3}/ZnSb multilayer configuration with low power consumption. - Abstract: Phase-change memory is regard as one of the most promising candidates for the next-generation non-volatile memory. In this work, we proposed a Sb{sub 7}Te{sub 3}/ZnSb multilayer thin films to improve the thermal stability of Sb-rich Sb{sub 3}Te{sub 7}. The sheet resistance ratio between amorphous and crystalline states reached up to 4 orders of magnitude. With regard to the thermal stability, the calculated temperature for 10-year data retention is about 127 °C. The threshold current and threshold voltage of a cell based on Sb{sub 7}Te{sub 3}/ZnSb are 6.9 μA and 1.9 V, respectively. The lower RESET power is presented in the PCM cells of Sb{sub 7}Te{sub 3}/ZnSb films, benefiting from its high resistivity.

  5. Study of conformational changes and protein aggregation of bovine serum albumin in presence of Sb(III) and Sb(V).

    Science.gov (United States)

    Verdugo, Marcelo; Ruiz Encinar, Jorge; Costa-Fernández, José Manuel; Menendez-Miranda, Mario; Bouzas-Ramos, Diego; Bravo, Manuel; Quiroz, Waldo

    2017-01-01

    Antimony is a metalloid that affects biological functions in humans due to a mechanism still not understood. There is no doubt that the toxicity and physicochemical properties of Sb are strongly related with its chemical state. In this paper, the interaction between Sb(III) and Sb(V) with bovine serum albumin (BSA) was investigated in vitro by fluorescence spectroscopy, and circular dichroism (CD) under simulated physiological conditions. Moreover, the coupling of the separation technique, asymmetric flow field-flow fractionation, with elemental mass spectrometry to understand the interaction of Sb(V) and Sb(III) with the BSA was also used. Our results showed a different behaviour of Sb(III) vs. Sb(V) regarding their effects on the interaction with the BSA. The effects in terms of protein aggregates and conformational changes were higher in the presence of Sb(III) compared to Sb(V) which may explain the differences in toxicity between both Sb species in vivo. Obtained results demonstrated the protective effect of GSH that modifies the degree of interaction between the Sb species with BSA. Interestingly, in our experiments it was possible to detect an interaction between BSA and Sb species, which may be related with the presence of labile complex between the Sb and a protein for the first time.

  6. Effect of AlSb buffer layer thickness on heteroepitaxial growth of InSb films on a Si(001) substrate

    International Nuclear Information System (INIS)

    Mori, M.; Murata, K.; Fujimoto, N.; Tatsuyama, C.; Tambo, T.

    2007-01-01

    Aluminum antimonide (AlSb) layers with various thickness ranged from about 8 to 250 nm were grown at 520 deg. C as the buffer layer for the heteroepitaxial growth of InSb films on Si(001) substrates. InSb films were grown at 400 deg. C on the AlSb/Si(001), and were characterized by X-ray diffraction (XRD), atomic force microscope, as a function of the thickness of the AlSb layer. The XRD patterns of the InSb films grown on the AlSb layers show that even if the AlSb buffer layer, whose surface consists of many islands, is as thin as 8 nm, it is effective for the heteroepitaxial growth of InSb film on a Si(001) substrate, and the AlSb layer of about 40 nm is thick enough to grow heteroepitaxial InSb films on the Si(001) substrate. The results of the φ scan patterns of the films show that InSb films on a Si(001) substrate with AlSb buffer layer were heteroepitaxially grown without any rotation in the growth plane

  7. Phase transformation in Mg—Sb3Te thin films

    International Nuclear Information System (INIS)

    Li Jun-Jian; Chen Yi-Min; Nie Qiu-Hua; Lü Ye-Gang; Wang Guo-Xiang; Shen Xiang; Dai Shi-Xun; Xu Tie-Feng

    2014-01-01

    Mg-doped Sb 3 Te films are proposed to improve the performance of phase-change memory (PCM). We prepare Mg-doped Sb 3 Te films and investigate their crystallization behaviors, structural, optical and electrical properties. We find that Mg-doping can increase the crystallization temperature, enhance the activation energy, and improve the 10-year data retention of Sb 3 Te. Especially Mg 25.19 (Sb 3 Te)74.81 shows higher T c (∼ 190 °C) and larger E a (∼ 3.49 eV), which results in a better data retention maintaining for 10 yr at ∼ 112 °C. Moreover R a /R c value is also improved. These excellent properties make Mg—Sb—Te material a promising candidate for the phase-change memory (PCM). (special topic — international conference on nanoscience and technology, china 2013)

  8. Hall Mobility of Amorphous Ge2Sb2Te5

    National Research Council Canada - National Science Library

    Baily, S. A; Emin, David; Li, Heng

    2006-01-01

    The electrical conductivity, Seebeck coefficient, and Hall coefficient of 3 micron thick films of amorphous Ge2Sb2Te5 have been measured as functions of temperature from room temperature down to as low as 200 K...

  9. Investigation of vibration spectrum ferroelectric semiconductor SbSBr nanowire

    International Nuclear Information System (INIS)

    Audzijonis, A.; Zigas, L.; Kvedaravicius, A.; Sereika, R.; Zaltauskas, R.; Cerskus, A

    2010-01-01

    The temperature dependence of vibration spectra of one SbSBr chain (nanowire) in the direction of the c(z)-axis has been calculated in quasiharmonic approximation by diagonalization of dynamical matrix. The vibrational frequencies in the direction of c(z)-axis have been derived by fitting of the experimental low-frequency ω s 2 of soft infrared (IR) mode of bulk-size SbSBr with the theoretical quasiharmonic low-frequency ω 2 of SbSBr nanowires. In this work the nature of anharmonism and temperature dependence of force constants between atoms in SbSBr crystal along c(z)-axis have been discussed. The anharmonism of all soft (at BZ k=0) modes has been created by the interaction between phonons.

  10. Electron transport in InAs/AlSb quantum wells

    International Nuclear Information System (INIS)

    Tuttle, G.; Kroemer, H.; English, J.H.

    1989-01-01

    The authors present data on electron transport in AlSb/InAs/AlSb quantum wells grown by molecular beam epitaxy. Because both anion and cation change across an InAs/Alsb interface, it is possible to grow such wells with two different types of interfaces, one with an InSb-like bond configuration, the other AlAs-like. Electron mobility and concentration were found to depend very strongly on the manner in which the quantum well's interfaces were grown, with high mobilities seen only if the bottom interface is InSb-like. An As-on-Al sites antisite defect model is postulated for bottom AlAs-like interfaces

  11. Investigation of impurity states in AlSb

    International Nuclear Information System (INIS)

    Agaev, Ya.; Bekmedova, N.G.; Mikhailov, A.P.

    1976-01-01

    The spectra of infrared absorption and the Hall effect have been investigated in the impurity region of aluminium antimonide crystals doped with sulphur and tellurium. By the measurements of the Hall effect temperature dependence in n-AlSb(S) and n-AlSb(Te) crystals determined is the activation energy of an impurity level equal to 0.24 eV and 0.068 eV respectively. The ionization energy for n-AlSb(S), equal to 0.22 eV, and for n-AlSb(Te) equal to 0.09 eV has been found from the infrared absorption curves. The absorption bands caused by the ionized impurity-band transition have been shown to be well described by the Callouway formula. Deep impurity centers have been revealed

  12. Defects in AlSb: a density functional study

    International Nuclear Information System (INIS)

    Du, Mao-Hua

    2009-01-01

    We carry out density functional calculations to study both intrinsic and extrinsic defects in AlSb. We focus on the carrier compensation and trapping properties of these defects, which are important to the radiation detection applications. We show that the Sb antisite is a low-energy defect, baring much similarity to the As antisite in GaAs. The SbAl is effective in compensating holes induced by the residual carbon, but is also a deep electron trap that reduces the carrier drifting length. We discuss the possibility of using hydrogenated isovalent N impurity in AlSb and GaAs to pin the Fermi level without causing efficient carrier trapping.

  13. Magneto-Optical Properties of InSb Semiconductor Heterostructures

    Science.gov (United States)

    Pan, X.; Saha, D.; Sanders, G. D.; Stanton, C. J.; Kasturiarachchi, T.; Edirisooriya, M.; Mishima, T. D.; Doezema, R. E.; Santos, M. B.

    2011-12-01

    We have theoretically and experimentally studied the spin-dependent Landau levels for electrons and holes in narrow-gap InSb/AlInSb quantum well systems. We use the envelope function approximation for the electronic and magneto-optical properties of InSb/AlInSb. Our model includes the conduction electrons, heavy holes, light holes and spin-orbit split-off holes for a total of 8 bands taking spin into account. The Pidgeon-Brown model is generalized to include the effects of confinement in the quantum wells. In addition, strain effects are taken into account by assuming pseudomorphic growth conditions. Comparing our calculated electronic structures with experimental magneto-absorption measurements, we obtain excellent agreement. Our results demonstrate that in addition to the major transitions, strong band mixing in the narrow gap material leads to several optical transitions which normally are forbidden.

  14. Chemical sensors for breath gas analysis: the latest developments at the Breath Analysis Summit 2013.

    Science.gov (United States)

    Tisch, Ulrike; Haick, Hossam

    2014-06-01

    Profiling the body chemistry by means of volatile organic compounds (VOCs) in the breath opens exciting new avenues in medical diagnostics. Gas sensors could provide ideal platforms for realizing portable, hand-held breath testing devices in the near future. This review summarizes the latest developments and applications in the field of chemical sensors for diagnostic breath testing that were presented at the Breath Analysis Summit 2013 in Wallerfangen, Germany. Considerable progress has been made towards clinically applicable breath testing devices, especially by utilizing chemo-sensitive nanomaterials. Examples of several specialized breath testing applications are presented that are either based on stand-alone nanomaterial-based sensors being highly sensitive and specific to individual breath compounds over others, or on combinations of several highly specific sensors, or on experimental nanomaterial-based sensors arrays. Other interesting approaches include the adaption of a commercially available MOx-based sensor array to indirect breath testing applications, using a sample pre-concentration method, and the development of compact integrated GC-sensor systems. The recent trend towards device integration has led to the development of fully integrated prototypes of point-of-care devices. We describe and compare the performance of several prototypes that are based on different sensing technologies and evaluate their potential as low-cost and readily available next-generation medical devices.

  15. X-ray photoelectron spectroscopic study of PuSb

    International Nuclear Information System (INIS)

    Baptist, R.; Chayrouse, J.; Courteix, D.; Heintz, L.; Damien, D.; Wojakowski, A.

    1983-01-01

    After presenting photoemission results for two uranium monopnictides, uranium nitride and antimonide, we present and analyse the X-ray photoemission spectroscopy results for PuSb. The increase of the 5f electron localization along the uranium monopnictides series is also observed when going from USb to PuSb. In this last case, the localization is due to an increase of the 5f intra-atomic Coulomb interaction in plutonium atoms compared to that in the uranium atoms [fr

  16. InSb as a γ-ray detector

    Science.gov (United States)

    McHarris, Wm. C.

    1986-01-01

    The III-V semiconductor InSb has the potential for being a superior γ-ray detector, with a possible improvement over Ge by the factors: resolution, 2 ×; peak-to-Compton ratio, 12 ×; efficiency (per mole), 9 ×. Recent availability of "intrinsic" InSb, coupled with pulse-height discrimination techniques to overcome geometrical dependence on charge collection, makes it feasible to investigate the practicality of this material for producing detectors. We discuss its advantages and disadvantages.

  17. Photoluminescence from narrow InAs-AlSb quantum wells

    Science.gov (United States)

    Brar, Berinder; Kroemer, Herbert; Ibbetson, James; English, John H.

    1993-01-01

    We report on photoluminescence spectra from narrow InAs-AlSb quantum wells. Strong, clearly resolved peaks for well widths from 2 to 8 monolayers were observed. Transmission electron micrographs show direct evidence for the structural quality of the quantum well structures. The transition energies of the narrowest wells suggest a strong influence of the AlSb X-barrier on the electronic states in the conduction band.

  18. A case of spontaneous ventriculocisternostomy

    International Nuclear Information System (INIS)

    Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru; Kuwabara, Satoshi.

    1983-01-01

    The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH 2 O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy. (J.P.N.)

  19. Optical antenna enhanced spontaneous emission.

    Science.gov (United States)

    Eggleston, Michael S; Messer, Kevin; Zhang, Liming; Yablonovitch, Eli; Wu, Ming C

    2015-02-10

    Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼ 200 THz optical frequency show a spontaneous emission intensity enhancement of 35 × corresponding to a spontaneous emission rate speedup ∼ 115 ×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼ 2,500 × spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d(2). Unfortunately, at d antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, I(o) = qω|x(o)|/d, feeding the antenna-enhanced spontaneous emission, where q|x(o)| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency.

  20. High Current Density InAsSb/GaSb Tunnel Field Effect Transistors

    OpenAIRE

    Dey, Anil; Borg, Mattias; Ganjipour, Bahram; Ek, Martin; Dick Thelander, Kimberly; Lind, Erik; Nilsson, Peter; Thelander, Claes; Wernersson, Lars-Erik

    2012-01-01

    Steep-slope devices, such as tunnel field-effect transistors (TFETs), have recently gained interest due to their potential for low power operation at room temperature. The devices are based on inter-band tunneling which could limit the on-current since the charge carriers must tunnel through a barrier to traverse the device. The InAs/GaSb heterostructure forms a broken type II band alignment which enables inter-band tunneling without a barrier, allowing high on-currents. We ha...

  1. Acoustic absorption in n=InSb

    International Nuclear Information System (INIS)

    Akhmedov, S.Eh.; Podoplelova, V.L.; Roj, V.F.

    1976-01-01

    The temperature dependence was studied of the electric conductivity (sigma), the acoustic electromotive force Esub(ae) and the coefficient of absorption of ultra sound (a) in a wide temperature range (1.4 to 300 deg K) of monocrystals n-InSb with a concentration of carriers n=2.3 10 14 cm -3 at the temperature of 77 K. The relationship sigma(T) is of a nature common to semiconductors throughout the temperature range. The relationship a(T) in the range from 80 to 180 K changes little with the temperature. In the range of 30 to 80 K, the absorption coefficient drops sharply. In the 4.2-30 K temperature range the value of the coefficient of absorption increases. The correlation should be noted between the relationships a(T) and sigma(T) practically throughout the whole range of the investigated temperatures. This is particularly observable at temperatures below 30 K and above 180 K. Peaks of a(T) at very low temperatures are observable only on excitation of non-equilibrium current carriers and are explainable in terms of the exciton-phonon interaction or interaction of the ultrasound with electron-hole drops

  2. Spontaneous baroreflex by sequence and power spectral methods in humans.

    Science.gov (United States)

    Hughson, R L; Quintin, L; Annat, G; Yamamoto, Y; Gharib, C

    1993-11-01

    Beat-by-beat variations in blood pressure and RR-interval are interrelated by the actions of baroreflex and non-baroreflex responses. This study had two purposes: (1) to examine the spontaneous relationships between RR-interval and systolic blood pressure to determine the relative occurrence of baroreflex and non-baroreflex responses in humans, and (2) to compare the beat-sequence method with a cross spectral estimate of the baroreflex response slope. Eight healthy men were studied during 10 h of quiet, seated rest, and six men and three women were studied during rest, rest plus fixed pace breathing, and a cold pressor test. RR-interval and continuous, non-invasive arterial blood pressure were measured with a computerized system. A baroreflex sequence was defined by a series of at least three consecutive heart beats in which systolic pressure and the following RR-interval either both increased or both decreased. A non-baroreflex relationship was defined by sequences of at least three beats by opposite directional changes of RR-interval and systolic pressure of that beat. The results showed that there were approximately 30% as many non-baroreflex compared to baroreflex slopes. Individual subject mean baroreflex and non-baroreflex slopes were highly correlated (r = 0.72, P < 0.001). Absolute slope values were not different, and they were unaffected by time, fixed pace breathing, or cold pressor test. The data showed the relatively simple beat-by-beat sequence method to yield spontaneous baroreflex response slopes that were quantitatively similar to, and highly correlated with (r = 0.85-0.94), baroreflex response slopes calculated by spectral analysis methods.

  3. Origin of p-type conductivity of Sb-doped ZnO nanorods and the local structure around Sb ions

    International Nuclear Information System (INIS)

    Liang, J. K.; Su, H. L.; Wu, Y. C.; Chuang, P. Y.; Kuo, C. L.; Huang, S. Y.; Chan, T. S.; Huang, J. C. A.

    2015-01-01

    To probe the origin of p-type conductivity in Sb-doped ZnO, a careful and detailed synchrotron radiation study was performed. The extended X-ray absorption fine structure and X-ray photoelectron spectroscopy investigations provided the evidence for the formation of the complex defects comprising substitution Sb ions at Zn sites (Sb Zn ) and Zn vacancies within the Sb-doped ZnO lattice. Such complex defects result in the increases of Sb-O coordination number and the Sb valence and thereby lead to the p-type conductivity of Sb-doped ZnO. The back-gate field-effect-transistors based on single nanorod of Sb-doped ZnO were constructed, and the stable p-type conduction behavior was confirmed

  4. The antimony-group 11 chemical bond: dissociation energies of the diatomic molecules CuSb, AgSb, and AuSb.

    Science.gov (United States)

    Carta, V; Ciccioli, A; Gigli, G

    2014-02-14

    The intermetallic molecules CuSb, AgSb, and AuSb were identified in the effusive molecular beam produced at high temperature under equilibrium conditions in a double-cell-like Knudsen source. Several gaseous equilibria involving these species were studied by mass spectrometry as a function of temperature in the overall range 1349-1822 K, and the strength of the chemical bond formed between antimony and the group 11 metals was for the first time measured deriving the following thermochemical dissociation energies (D°(0), kJ/mol): 186.7 ± 5.1 (CuSb), 156.3 ± 4.9 (AgSb), 241.3 ± 5.8 (AuSb). The three species were also investigated computationally at the coupled cluster level with single, double, and noniterative quasiperturbative triple excitations (CCSD(T)). The spectroscopic parameters were calculated from the potential energy curves and the dissociation energies were evaluated at the Complete Basis Set limit, resulting in an overall good agreement with experimental values. An approximate evaluation of the spin-orbit effect was also performed. CCSD(T) calculations were further extended to the corresponding group 11 arsenide species which are here studied for the first time and the following dissociation energies (D°(0), kJ/mol): 190 ± 10 (CuAs), 151 ± 10 (AgAs), 240 ± 15 (AuAs) are proposed. Taking advantage of the new experimental and computational information here presented, the bond energy trends along group 11 and 4th and 5th periods of the periodic table were analyzed and the bond energies of the diatomic species CuBi and AuBi, yet experimentally unobserved, were predicted on an empirical basis.

  5. Role of interlayer coupling for the power factor of CuSbS2 and CuSbSe2

    KAUST Repository

    Alsaleh, Najebah M.

    2016-09-26

    The electronic and transport properties of bulk and monolayer CuSbS2 and CuSbSe2 are determined by using density functional theory and semiclassical Boltzmann transport theory, in order to investigate the role of interlayer coupling for the thermoelectric properties. The calculated band gaps of the bulk compounds are in agreement with experiments and significantly higher than those of the monolayers, which thus show lower Seebeck coefficients. Since also the electrical conductivity is lower, the monolayers are characterized by lower power factors. Therefore, interlayer coupling is found to be essential for the excellent thermoelectric response of CuSbS2 and CuSbSe2, even though it is weak.

  6. Role of interlayer coupling for the power factor of CuSbS2 and CuSbSe2

    KAUST Repository

    Alsaleh, Najebah Mohammed Abdullah

    2017-01-08

    The electronic and transport properties of bulk and monolayer CuSbS2 and CuSbSe2 are determined by using density functional theory and semiclassical Boltzmann transport theory, in order to investigate the role of interlayer coupling for the thermoelectric properties. The calculated band gaps of the bulk compounds are in agreement with experiments and significantly higher than those of the monolayers, which thus show lower Seebeck coefficients. Since also the electrical conductivity is lower, the monolayers are characterized by lower power factors. Therefore, interlayer coupling is found to be essential for the excellent thermoelectric response of CuSbS2 and CuSbSe2, even though it is weak.

  7. Ferro electrical properties of GeSbTe thin films; Propiedades ferroelectricas de peliculas delgadas de GeSbTe

    Energy Technology Data Exchange (ETDEWEB)

    Gervacio A, J. J.; Prokhorov, E.; Espinoza B, F. J., E-mail: jgervacio@qro.cinvestav.m [IPN, Centro de Investigacion y de Estudios Avanzados, Unidad Queretaro, Libramiento Norponiente No. 2000, Juriquilla, 76230 Queretaro (Mexico)

    2011-07-01

    The aim of this work is to investigate and compare ferro electrical properties of thin GeSbTe films with composition Ge{sub 4}Sb{sub 1}Te{sub 5} (with well defined ferro electrical properties) and Ge{sub 2}Sb{sub 2}Te{sub 5} using impedance, optical reflection, XRD, DSc and Piezo response Force Microscopy techniques. The temperature dependence of the capacitance in both materials shows an abrupt change at the temperature corresponding to ferroelectric-paraelectric transition and the Curie-Weiss dependence. In Ge{sub 2}Sb{sub 2}Te{sub 5} films this transition corresponds to the end from a NaCl-type to a hexagonal transformation. Piezo response Force Microscopy measurements found ferroelectric domains with dimension approximately equal to the dimension of grains. (Author)

  8. Crystal structure, magnetism, {sup 89}Y solid state NMR, and {sup 121}Sb Moessbauer spectroscopic investigations of YIrSb

    Energy Technology Data Exchange (ETDEWEB)

    Benndorf, Christopher [Institut fuer Physikalische Chemie, Universitaet Muenster (Germany); Institut fuer Anorganische und Analytische Chemie, Universitaet Muenster (Germany); Heletta, Lukas; Block, Theresa; Poettgen, Rainer [Institut fuer Anorganische und Analytische Chemie, Universitaet Muenster (Germany); Eckert, Hellmut [Institut fuer Physikalische Chemie, Universitaet Muenster (Germany); Institute of Physics in Sao Carlos, University of Sao Paulo, Sao Carlos (Brazil)

    2017-02-15

    The ternary antimonide YIrSb was synthesized from the binary precursor YIr and elemental antimony by a diffusion controlled solid-state reaction. Single crystals were obtained by a flux technique with elemental bismuth as an inert solvent. The YIrSb structure (TiNiSi type, space group Pnma) was refined from single-crystal X-ray diffractometer data: a = 711.06(9), b = 447.74(5), c = 784.20(8) pm, wR{sub 2} = 0.0455, 535 F{sup 2} values, 20 variables. {sup 89}Y solid state MAS NMR and {sup 121}Sb Moessbauer spectra show single resonance lines in agreement with single-crystal X-ray data. YIrSb is a Pauli paramagnet. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Thermal annealing effects on AlGaAsSb/GaSb laser structure: Bandgap energy blueshift and thermal conductivity enhancement

    Science.gov (United States)

    Ilahi, S.; Yacoubi, N.; Genty, F.

    2017-07-01

    In this paper, we have investigated the effects of thermal annealing on optical properties and thermal conductivity of AlGaAsSb/GaSb laser structure using photo-thermal deflection spectroscopy PDS. In fact, optical absorption spectrum and thermal conductivity have been determined by comparison between experimental and theoretical phase of PDS signal. We have found that band gap energy is blue shifted of 70 meV for the as grown to the sample annealed for 1 h. Indeed, the highest thermal conductivity is found around of 11 W/m.K for AlGaAsSb/GaSb annealed for 1 h, which presents a promising result for vertical-cavity surface-emitting lasers (VCSELs).

  10. Effects of ion channel noise on neural circuits: an application to the respiratory pattern generator to investigate breathing variability.

    Science.gov (United States)

    Yu, Haitao; Dhingra, Rishi R; Dick, Thomas E; Galán, Roberto F

    2017-01-01

    Neural activity generally displays irregular firing patterns even in circuits with apparently regular outputs, such as motor pattern generators, in which the output frequency fluctuates randomly around a mean value. This "circuit noise" is inherited from the random firing of single neurons, which emerges from stochastic ion channel gating (channel noise), spontaneous neurotransmitter release, and its diffusion and binding to synaptic receptors. Here we demonstrate how to expand conductance-based network models that are originally deterministic to include realistic, physiological noise, focusing on stochastic ion channel gating. We illustrate this procedure with a well-established conductance-based model of the respiratory pattern generator, which allows us to investigate how channel noise affects neural dynamics at the circuit level and, in particular, to understand the relationship between the respiratory pattern and its breath-to-breath variability. We show that as the channel number increases, the duration of inspiration and expiration varies, and so does the coefficient of variation of the breath-to-breath interval, which attains a minimum when the mean duration of expiration slightly exceeds that of inspiration. For small channel numbers, the variability of the expiratory phase dominates over that of the inspiratory phase, and vice versa for large channel numbers. Among the four different cell types in the respiratory pattern generator, pacemaker cells exhibit the highest sensitivity to channel noise. The model shows that suppressing input from the pons leads to longer inspiratory phases, a reduction in breathing frequency, and larger breath-to-breath variability, whereas enhanced input from the raphe nucleus increases breathing frequency without changing its pattern. A major source of noise in neuronal circuits is the "flickering" of ion currents passing through the neurons' membranes (channel noise), which cannot be suppressed experimentally. Computational

  11. Trained breathing-induced oxygenation acutely reverses cardiovascular autonomic dysfunction in patients with type 2 diabetes and renal disease.

    Science.gov (United States)

    Esposito, Pasquale; Mereu, Roberto; De Barbieri, Giacomo; Rampino, Teresa; Di Toro, Alessandro; Groop, Per-Henrik; Dal Canton, Antonio; Bernardi, Luciano

    2016-04-01

    Cardiovascular autonomic dysfunction, evaluated as baroreflex sensitivity (BRS), could be acutely corrected by slow breathing or oxygen administration in patients with type 1 diabetes, thus suggesting a functional component of the disorder. We tested this hypothesis in patients with the type 2 diabetes with or without renal impairment. Twenty-six patients with type 2 diabetes (aged 61.0 ± 0.8 years, mean ± SEM; duration of diabetes 10.5 ± 2 years, BMI 29.9 ± 0.7 kg/m(2), GFR 68.1 ± 5.6 ml/min) and 24 healthy controls (aged 58.5 ± 1.0 years) were studied. BRS was obtained from recordings of RR interval and systolic blood pressure fluctuations during spontaneous and during slow, deep (6 breaths/min) controlled breathing in conditions of normoxia or hyperoxia (5 l/min oxygen). During spontaneous breathing, diabetic patients had lower RR interval and lower BRS compared with the control subjects (7.1 ± 1.2 vs. 12.6 ± 2.0 ms/mmHg, p breathing and oxygen administration significantly increased arterial saturation, reduced RR interval and increased BRS in both groups (to 9.6 ± 1.8 and 15.4 ± 2.4 ms/mmHg, respectively, p breathing and hyperoxia (p breathing during normoxia). Autonomic dysfunction present in patients with type 2 diabetes can be partially reversed by slow breathing, suggesting a functional role of hypoxia, also in patients with DKD. Interventions known to relieve tissue hypoxia and improve autonomic function, like physical activity, may be useful in the prevention and management of complications in patients with diabetes.

  12. Spontaneous subcapsular and perirrenal hemorrhage

    International Nuclear Information System (INIS)

    Fuster, M.J.; Saez, J.; Perez-Paya, F.J.; Fernandez, F.

    1997-01-01

    To assess the role of CT in the etiologic diagnosis of spontaneous subcapsular and perirrenal hemorrhage. The CT findings are described in 13 patients presenting subcapsular and perirrenal hemorrhage. Those patients in whom the bleeding was not spontaneous were excluded. Surgical confirmation was obtained in nine cases. In 11 of the 13 cases (84.6%), involving five adenocarcinomas, five angiomyolipoma, two complicated cysts and one case of panarterities nodosa, CT disclosed the underlying pathology. In two cases (15.4%), it only revealed the extension of the hematoma, but gave no clue to its origin. CT is the technique of choice when spontaneous subcapsular and perirrenal hemorrhage is suspected since, in most cases, it reveals the underlying pathology. (Author)

  13. Decreased chewing activity during mouth breathing.

    Science.gov (United States)

    Hsu, H-Y; Yamaguchi, K

    2012-08-01

    This study examined the effect of mouth breathing on the strength and duration of vertical effect on the posterior teeth using related functional parameters during 3 min of gum chewing in 39 nasal breathers. A CO(2) sensor was placed over the mouth to detect expiratory airflow. When no airflow was detected from the mouth throughout the recording period, the subject was considered a nasal breather and enrolled in the study. Electromyographic (EMG) activity was recorded during 3 min of gum chewing. The protocol was repeated with the nostrils occluded. The strength of the vertical effect was obtained as integrated masseter muscle EMG activity, and the duration of vertical effect was also obtained as chewing stroke count, chewing cycle variation and EMG activity duration above baseline. Baseline activity was obtained from the isotonic EMG activity during jaw movement at 1.6 Hz without making tooth contact. The duration represented the percentage of the active period above baseline relative to the 3-min chewing period. Paired t-test and repeated analysis of variance were used to compare variables between nasal and mouth breathing. The integrated EMG activity and the duration of EMG activity above baseline, chewing stroke count and chewing cycle significantly decreased during mouth breathing compared with nasal breathing (Pbreathing was significantly greater than nasal breathing (Pbreathing reduces the vertical effect on the posterior teeth, which can affect the vertical position of posterior teeth negatively, leading to malocclusion. © 2012 Blackwell Publishing Ltd.

  14. Sudarshan kriya yoga: Breathing for health

    Directory of Open Access Journals (Sweden)

    Sameer A Zope

    2013-01-01

    Full Text Available Breathing techniques are regularly recommended for relaxation, stress management, control of psychophysiological states, and to improve organ function. Yogic breathing, defined as a manipulation of breath movement, has been shown to positively affect immune function, autonomic nervous system imbalances, and psychological or stress-related disorders. The aim of this study was to assess and provide a comprehensive review of the physiological mechanisms, the mind-body connection, and the benefits of Sudarshan Kriya Yoga (SKY in a wide range of clinical conditions. Various online databases searched were Medline, Psychinfo, EMBASE, and Google Scholar. All the results were carefully screened and articles on SKY were selected. The references from these articles were checked to find any other potentially relevant articles. SKY, a unique yogic breathing practice, involves several types of cyclical breathing patterns, ranging from slow and calming to rapid and stimulating. There is mounting evidence to suggest that SKY can be a beneficial, low-risk, low-cost adjunct to the treatment of stress, anxiety, post-traumatic stress disorder, depression, stress-related medical illnesses, substance abuse, and rehabilitation of criminal offenders.

  15. The clinical value of breath hydrogen testing.

    Science.gov (United States)

    Yao, Chu K; Tuck, Caroline J

    2017-03-01

    Breath hydrogen testing for assessing the presence of carbohydrate malabsorption is frequently applied to refine dietary restrictions on a low fermentable carbohydrate (FODMAP) diet. Its application has also been extended for the detection of small intestinal bacterial overgrowth. Recently, several caveats of its methodology and interpretation have emerged. A review of the evidence surrounding its application in the management of patients with a functional bowel disorder was performed. Studies were examined to assess limitations of testing methodology, interpretation of results, reproducibility, and how this relates to clinical symptoms. A wide heterogeneity in testing parameters, definition of positive/negative response, and the use of clinically irrelevant doses of test carbohydrate were common methodological limitations. These factors can subsequently impact the sensitivity, specificity, and false positive or negative detection rates. Evidence is also increasing on the poor intra-individual reproducibility in breath responses with repeated testing for fructose and lactulose. On the basis of these limitations, it is not surprising that the diagnosis of small intestinal bacterial overgrowth based on a lactulose breath test yields a wide prevalence rate and is unreliable. Finally, symptom induction during a breath test has been found to correlate poorly with the presence of carbohydrate malabsorption. The evidence suggests that breath hydrogen tests have limited clinical value in guiding clinical decision for the patient with a functional bowel disorder. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  16. AgSbSe2 and AgSb(S,Se)2 thin films for photovoltaic applications

    International Nuclear Information System (INIS)

    Garza, J.G.; Shaji, S.; Rodriguez, A.C.; Das Roy, T.K.; Krishnan, B.

    2011-01-01

    Silver antimony selenide (AgSbSe 2 ) thin films were prepared by heating sequentially deposited multilayers of antimony sulphide (Sb 2 S 3 ), silver selenide (Ag 2 Se), selenium (Se) and silver (Ag). Sb 2 S 3 thin film was prepared from a chemical bath containing SbCl 3 and Na 2 S 2 O 3 , Ag 2 Se from a solution containing AgNO 3 and Na 2 SeSO 3 and Se thin films from an acidified solution of Na 2 SeSO 3 , at room temperature on glass substrates. Ag thin film was deposited by thermal evaporation. The annealing temperature was 350 deg. C in vacuum (10 -3 Torr) for 1 h. X-ray diffraction analysis showed that the thin films formed were polycrystalline AgSbSe 2 or AgSb(S,Se) 2 depending on selenium content in the precursor films. Morphology and elemental analysis of these films were done using scanning electron microscopy and energy dispersive X-ray spectroscopy. Optical band gap was evaluated from the UV-visible absorption spectra of these films. Electrical characterizations were done using Hall effect and photocurrent measurements. A photovoltaic structure: glass/ITO/CdS/AgSbSe 2 /Al was formed, in which CdS was deposited by chemical bath deposition. J-V characteristics of this structure showed V oc = 435 mV and J sc = 0.08 mA/cm 2 under illumination using a tungsten halogen lamp. Preparation of a photovoltaic structure using AgSbSe 2 as an absorber material by a non-toxic selenization process is achieved.

  17. InAs/GaSb/AlSb composite quantum well structure preparation with help of reflectance anisotropy spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Hospodková, Alice; Hulicius, Eduard; Pangrác, Jiří; Dominec, Filip; Mikhailova, M. P.; Veinger, A.I.; Kochman, I.V.

    2017-01-01

    Roč. 464, Apr (2017), s. 206-210 ISSN 0022-0248 R&D Projects: GA MŠk LM2015087; GA MŠk LO1603 Institutional support: RVO:68378271 Keywords : low dimensional structures * MOVPE * InAs/GaSb composite quantum wells * AlSb Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.751, year: 2016

  18. Modelling nasal high flow therapy effects on upper airway resistance and resistive work of breathing.

    Science.gov (United States)

    Adams, Cletus F; Geoghegan, Patrick H; Spence, Callum J; Jermy, Mark C

    2018-04-07

    The goal of this paper is to quantify upper airway resistance with and without nasal high flow (NHF) therapy. For adults, NHF therapy feeds 30-60 L/min of warm humidified air into the nose through short cannulas which do not seal the nostril. NHF therapy has been reported to increase airway pressure, increase tidal volume (V t ) and decrease respiratory rate (RR), but it is unclear how these findings affect the work done to overcome airway resistance to air flow during expiration. Also, there is little information on how the choice of nasal cannula size may affect work of breathing. In this paper, estimates of airway resistance without and with different NHF flow (applied via different cannula sizes) were made. The breathing efforts required to overcome airway resistance under these conditions were quantified. NHF was applied via three different cannula sizes to a 3-D printed human upper airway. Pressure drop and flow rate were measured and used to estimate inspiratory and expiratory upper airway resistances. The resistance information was used to compute the muscular work required to overcome the resistance of the upper airway to flow. NHF raises expiratory resistance relative to spontaneous breathing if the breathing pattern does not change but reduces work of breathing if peak expiratory flow falls. Of the cannula sizes used, the large cannula produced the greatest resistance and the small cannula produced the least. The work required to cause tracheal flow through the upper airway was reduced if the RR and minute volume are reduced by NHF. NHF has been observed to do so in COPD patients (Bräunlich et al., 2013). A reduction in I:E ratio due to therapy was found to reduce work of breathing if the peak inspiratory flow is less than the flow below which no inspiratory effort is required to overcome upper airway resistance. NHF raises expiratory resistance but it can reduce the work required to overcome upper airway resistance via a fall in inspiratory work of

  19. [Efficacy of preoxygenation using tidal volume breathing: a comparison of Mapleson A, Bain's and Circle system].

    Science.gov (United States)

    Arora, Suman; Gupta, Priyanka; Arya, Virender Kumar; Bhatia, Nidhi

    Efficacy of preoxygenation depends upon inspired oxygen concentration, its flow rate, breathing system configuration and patient characteristics. We hypothesized that in actual clinical scenario, where breathing circuit is not primed with 100% oxygen, patients may need more time to achieve EtO 2 ≥90%, and this duration may be different among various breathing systems. We thus studied the efficacy of preoxygenation using unprimed Mapleson A, Bain's and Circle system with tidal volume breathing at oxygen flow rates of 5L.min -1 and 10L.min -1 . Patients were randomly allocated into one of the six groups, wherein they were preoxygenated using either Mapleson A, Bain's or Circle system at O 2 flow rate of either 5L.min -1 or 10L.min -1 . The primary outcome measure of our study was the time taken to achieve EtO 2 ≥90% at 5 and 10L.min -1 flow rates. At oxygen flow rate of 5L.min -1 , time to reach EtO 2 ≥90% was significantly longer with Bain's system (3.7±0.67min) than Mapleson A and Circle system (2.9±0.6, 3.3±0.97min, respectively). However at oxygen flow rate of 10L.min -1 this time was significantly shorter and comparable among all the three breathing systems (2.33±0.38min with Mapleson, 2.59±0.50min with Bain's and 2.60±0.47min with Circle system). With spontaneous normal tidal volume breathing at oxygen flow rate of 5L.min -1 , Mapleson A can optimally preoxygenate patients within 3min while Bain's and Circle system require more time. However at O 2 flow rate of 10L.min -1 all the three breathing systems are capable of optimally preoxygenating the patients in less than 3min. Copyright © 2017 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  20. Spontaneous isolated celiac artery dissection

    Directory of Open Access Journals (Sweden)

    Tuba Cimilli Ozturk

    2011-01-01

    Full Text Available Dyspepsia with mild, stabbing epigastric discomfort without history of trauma is a very common symptom that emergency physicians see in their daily practice. Vascular emergencies, mostly the aortic dissection and aneurysm, are always described in the differential diagnosis with persistent symptoms. Isolated celiac artery dissection occurring spontaneously is a very rare diagnosis. The involvement of branch vessels is generally observed and patients show various clinical signs and symptoms according to the involved branch vessel. Here we are presenting a case with spontaneous isolated celiac artery dissection, without any branch vessel involvement or visceral damage, detected by computed tomography scans taken on admission.

  1. Spontaneous waves in muscle fibres

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Stefan; Kruse, Karsten [Department of Theoretical Physics, Saarland University, 66041 Saarbruecken (Germany); Max Planck Institute for the Physics of Complex Systems, Noethnitzer Street 38, 01187 Dresden (Germany)

    2007-11-15

    Mechanical oscillations are important for many cellular processes, e.g. the beating of cilia and flagella or the sensation of sound by hair cells. These dynamic states originate from spontaneous oscillations of molecular motors. A particularly clear example of such oscillations has been observed in muscle fibers under non-physiological conditions. In that case, motor oscillations lead to contraction waves along the fiber. By a macroscopic analysis of muscle fiber dynamics we find that the spontaneous waves involve non-hydrodynamic modes. A simple microscopic model of sarcomere dynamics highlights mechanical aspects of the motor dynamics and fits with the experimental observations.

  2. Photoluminescence and structural properties of unintentional single and double InGaSb/GaSb quantum wells grown by MOVPE

    Science.gov (United States)

    Ahia, Chinedu Christian; Tile, Ngcali; Botha, Johannes R.; Olivier, E. J.

    2018-04-01

    The structural and photoluminescence (PL) characterization of InGaSb quantum well (QW) structures grown on GaSb substrate (100) using atmospheric pressure Metalorganic Vapor Phase Epitaxy (MOVPE) is presented. Both structures (single and double-InGaSb QWs) were inadvertently formed during an attempt to grow capped InSb/GaSb quantum dots (QDs). In this work, 10 K PL peak energies at 735 meV and 740 meV are suggested to be emissions from the single and double QWs, respectively. These lines exhibit red shifts, accompanied by a reduction in their full-widths at half-maximum (FWHM) as the excitation power decreases. The presence of a GaSb spacer in the double QW was found to increase the strength of the PL emission, which consequently gives rise to a reduced blue-shift and broadening of the PL emission line observed for the double QW with an increase in laser power, while the low thermal activation energy for the quenching of the PL from the double QW is attributed to the existence of threading dislocations, as seen in the bright field TEM image for this sample.

  3. Optimization of growth parameters for MOVPE-grown GaSb and Ga1−xInxSb

    International Nuclear Information System (INIS)

    Miya, S.S.; Wagener, V.; Botha, J.R.

    2012-01-01

    The triethylgallium/trimethylantimony (TEGa/TMSb) precursor combination was used for the metal-organic vapour phase epitaxial growth of GaSb at a growth temperature of 520 °C at atmospheric pressure. Trimethylindium was added in the case of Ga 1−x In x Sb growth. The effects of group V flux to group III flux ratio (V/III ratio) on the crystallinity and optical properties of GaSb layers are reported. It has been observed from the crystalline quality and optical properties that nominal V/III ratios of values greater than unity are required for GaSb epitaxial layers grown at this temperature. It has also been shown that Ga 1−x In x Sb can be grown using TEGa as a source of gallium species at atmospheric pressure. The relationship between Ga 1−x In x Sb vapour composition and solid composition has been studied at a V/III ratio of 0.78.

  4. New Insights into the Origins of Sb-Induced Effects on Self-Catalyzed GaAsSb Nanowire Arrays.

    Science.gov (United States)

    Ren, Dingding; Dheeraj, Dasa L; Jin, Chengjun; Nilsen, Julie S; Huh, Junghwan; Reinertsen, Johannes F; Munshi, A Mazid; Gustafsson, Anders; van Helvoort, Antonius T J; Weman, Helge; Fimland, Bjørn-Ove

    2016-02-10

    Ternary semiconductor nanowire arrays enable scalable fabrication of nano-optoelectronic devices with tunable bandgap. However, the lack of insight into the effects of the incorporation of Vy element results in lack of control on the growth of ternary III-V(1-y)Vy nanowires and hinders the development of high-performance nanowire devices based on such ternaries. Here, we report on the origins of Sb-induced effects affecting the morphology and crystal structure of self-catalyzed GaAsSb nanowire arrays. The nanowire growth by molecular beam epitaxy is changed both kinetically and thermodynamically by the introduction of Sb. An anomalous decrease of the axial growth rate with increased Sb2 flux is found to be due to both the indirect kinetic influence via the Ga adatom diffusion induced catalyst geometry evolution and the direct composition modulation. From the fundamental growth analyses and the crystal phase evolution mechanism proposed in this Letter, the phase transition/stability in catalyst-assisted ternary III-V-V nanowire growth can be well explained. Wavelength tunability with good homogeneity of the optical emission from the self-catalyzed GaAsSb nanowire arrays with high crystal phase purity is demonstrated by only adjusting the Sb2 flux.

  5. Gel-combustion synthesis of CoSb2O6 and its reduction to powdery Sb2Co alloy

    Directory of Open Access Journals (Sweden)

    MAJA JOVIC

    2009-01-01

    Full Text Available Sb2Co alloy in powdery form was synthesized via reduction with gaseous hydrogen of the oxide CoSb2O6, obtained by the citrate gel-combustion technique. The precursor was an aqueous solution of antimony nitrate, cobalt nitrate and citric acid. The precursor solution with mole ratio Co(II/Sb(V of 1:2 was gelatinized by evaporation of water. The gel was heated in air up to the temperature of self-ignition. The product of gel combustion was a mixture of oxides and it had to be additionally thermally treated in order to be converted to pure CoSb2O6. The reduction of CoSb2O6 by gaseous hydrogen yielded powdery Sb2Co as the sole phase. The process of oxide reduction to alloy was controlled by thermogravimetry, while X-ray diffractometry was used to control the phase compositions of both the oxides and alloys.

  6. Two-band superlinear electroluminescence in GaSb based nanoheterostructures with AlSb/InAs{sub 1−x} Sb{sub x}/AlSb deep quantum well

    Energy Technology Data Exchange (ETDEWEB)

    Mikhailova, M. P.; Ivanov, E. V.; Danilov, L. V.; Petukhov, A. A.; Kalinina, K. V.; Slobozhanyuk, S. I.; Zegrya, G. G.; Stoyanov, N. D.; Yakovlev, Yu. P. [Ioffe Physical Technical Institute RAS, 194021, Polytekhnicheskaya 26, St. Petersburg (Russian Federation); Hospodková, A.; Pangrác, J.; Oswald, J.; Zíková, M.; Hulicius, E. [Institute of Physics, AS CR, v.v.i., 162 00, Cukrovarnická 10, Prague 6 (Czech Republic)

    2014-06-14

    We report on superlinear electroluminescent structures based on AlSb/InAs{sub 1−x}Sb{sub x}/AlSb deep quantum wells grown by MOVPE on n-GaSb:Te substrates. Dependence of the electroluminescence (EL) spectra and optical power on the drive current in nanoheterostructures with AlSb/InAs{sub 1−x}Sb{sub x}/AlSb quantum well at 77–300 K temperature range was studied. Intensive two-band superlinear EL in the 0.5–0.8 eV photon energy range was observed. Optical power enhancement with the increasing drive current at room temperature is caused by the contribution of the additional electron-hole pairs due to the impact ionization by the electrons heated at the high energy difference between AlSb and the first electron level E{sub e1} in the InAsSb QW. Study of the EL temperature dependence at 90–300 K range enabled us to define the role of the first and second heavy hole levels in the radiative recombination process. It was shown that with the temperature decrease, the relation between the energies of the valence band offset and the second heavy hole energy level changes due to the temperature transformation of the energy band diagram. That is the reason why the EL spectrum revealed radiative transitions from the first electron level E{sub e1} to the first hole level E{sub h1} in the whole temperature range (90–300 K), while the emission band related with the transitions to the second hole level occurred only at T > 200 K. Comparative examination of the nanostructures with high band offsets and different interface types (AlAs-like and InSb-like) reveals more intense EL and optical power enhancement at room temperature in the case of AlAs-like interface that could be explained by the better quality of the heterointerface and more efficient hole localization.

  7. Clinical Applications of CO2 and H2 Breath Test

    Directory of Open Access Journals (Sweden)

    ZHAO Si-qian;CHEN Bao-jun;LUO Zhi-fu

    2016-08-01

    Full Text Available Breath test is non-invasive, high sensitivity and high specificity. In this article, CO2 breath test, H2 breath test and their clinical applications were elaborated. The main applications of CO2 breath test include helicobacter pylori test, liver function detection, gastric emptying test, insulin resistance test, pancreatic exocrine secretion test, etc. H2 breath test can be applied in the diagnosis of lactose malabsorption and detecting small intestinal bacterial overgrowth. With further research, the breath test is expected to be applied in more diseases diagnosis.

  8. On-line determination of Sb(III) and total Sb using baker's yeast immobilized on polyurethane foam and hydride generation inductively coupled plasma optical emission spectrometry

    Science.gov (United States)

    Menegário, Amauri A.; Silva, Ariovaldo José; Pozzi, Eloísa; Durrant, Steven F.; Abreu, Cassio H.

    2006-09-01

    The yeast Saccharomyces cerevisiae was immobilized in cubes of polyurethane foam and the ability of this immobilized material to separate Sb(III) and Sb(V) was investigated. A method based on sequential determination of total Sb (after on-line reduction of Sb(V) to Sb(III) with thiourea) and Sb(III) (after on-line solid-liquid phase extraction) by hydride generation inductively coupled plasma optical emission spectrometry is proposed. A flow system assembled with solenoid valves was used to manage all stages of the process. The effects of pH, sample loading and elution flow rates on solid-liquid phase extraction of Sb(III) were evaluated. Also, the parameters related to on-line pre-reduction (reaction coil and flow rates) were optimized. Detection limits of 0.8 and 0.15 μg L - 1 were obtained for total Sb and Sb(III), respectively. The proposed method was applied to the analysis of river water and effluent samples. The results obtained for the determination of total Sb were in agreement with expected values, including the river water Standard Reference Material 1640 certified by the National Institute of Standards and Technology (NIST). Recoveries of Sb(III) and Sb(V) in spiked samples were between 81 ± 19 and 111 ±15% when 120 s of sample loading were used.

  9. Helping Babies Breathe implementation in Zanzibar, Tanzania.

    Science.gov (United States)

    Wilson, Gina Marie; Ame, Ame Masemo; Khatib, Maimuna Mohamed; Rende, Elizabeth K; Hartman, Ann Michelle; Blood-Siegfried, Jane

    2017-08-01

    To assess the efficacy and feasibility of implementing Helping Babies Breathe, a neonatal resuscitation programme for resource-limited environments. This quality improvement project focused on training midwives on Helping Babies Breathe to address high rates of neonatal mortality secondary to birth asphyxia. The convenience sample was 33 midwives in Zanzibar, Tanzania. The train-the-trainer strategy with repeated measures design was used to assess knowledge and skills at 3 time points. Observations were completed during "real-time" deliveries, and a focused interview generated feedback regarding satisfaction and sustainability. Knowledge scores and resuscitation skills significantly improved and were sustained, P < .05. Of the 62 birth observations, 19% needed intervention. All were appropriately resuscitated and survived. Results indicate that participants retained knowledge and skills and used them in clinical practice. Observations demonstrated that participants took appropriate actions when presented with a baby who was not breathing. © 2017 John Wiley & Sons Australia, Ltd.

  10. Human Papillomavirus Infection as a Possible Cause of Spontaneous Abortion and Spontaneous Preterm Delivery

    DEFF Research Database (Denmark)

    Ambühl, Lea Maria Margareta; Baandrup, Ulrik; Dybkær, Karen

    2016-01-01

    , and 10.9% (95% CI; 10.1–11.7) for umbilical cord blood. Summary estimates for HPV prevalence of spontaneous abortions and spontaneous preterm deliveries, in cervix (spontaneous abortions: 24.5%, and pretermdeliveries: 47%, resp.) and placenta (spontaneous abortions: 24.9%, and preterm deliveries: 50......%, resp.), were identified to be higher compared to normal full-term pregnancies (푃 spontaneous abortion, spontaneous preterm...

  11. Acoustic signal classification of breathing movements to virtually aid breath regulation.

    Science.gov (United States)

    Abushakra, Ahmad; Faezipour, Miad

    2013-03-01

    Monitoring breath and identifying breathing movements have settled importance in many biomedical research areas, especially in the treatment of those with breathing disorders, e.g., lung cancer patients. Moreover, virtual reality (VR) revolution and their implementations on ubiquitous hand-held devices have a lot of implications, which could be used as a simulation technology for healing purposes. In this paper, a novel method is proposed to detect and classify breathing movements. The overall VR framework is intended to encourage the subjects regulate their breath by classifying the breathing movements in real time. This paper focuses on a portion of the overall VR framework that deals with classifying the acoustic signal of respiration movements. We employ Mel-frequency cepstral coefficients (MFCCs) along with speech segmentation techniques using voice activity detection and linear thresholding to the acoustic signal of breath captured using a microphone to depict the differences between inhale and exhale in frequency domain. For every subject, 13 MFCCs of all voiced segments are computed and plotted. The inhale and exhale phases are differentiated using the sixth MFCC order, which carries important classification information. Experimental results on a number of individuals verify our proposed classification methodology.

  12. Adaptive neuro-fuzzy inference system for breath phase detection and breath cycle segmentation.

    Science.gov (United States)

    Palaniappan, Rajkumar; Sundaraj, Kenneth; Sundaraj, Sebastian

    2017-07-01

    The monitoring of the respiratory rate is vital in several medical conditions, including sleep apnea because patients with sleep apnea exhibit an irregular respiratory rate compared with controls. Therefore, monitoring the respiratory rate by detecting the different breath phases is crucial. This study aimed to segment the breath cycles from pulmonary acoustic signals using the newly developed adaptive neuro-fuzzy inference system (ANFIS) based on breath phase detection and to subsequently evaluate the performance of the system. The normalised averaged power spectral density for each segment was fuzzified, and a set of fuzzy rules was formulated. The ANFIS was developed to detect the breath phases and subsequently perform breath cycle segmentation. To evaluate the performance of the proposed method, the root mean square error (RMSE) and correlation coefficient values were calculated and analysed, and the proposed method was then validated using data collected at KIMS Hospital and the RALE standard dataset. The analysis of the correlation coefficient of the neuro-fuzzy model, which was performed to evaluate its performance, revealed a correlation strength of r = 0.9925, and the RMSE for the neuro-fuzzy model was found to equal 0.0069. The proposed neuro-fuzzy model performs better than the fuzzy inference system (FIS) in detecting the breath phases and segmenting the breath cycles and requires less rules than FIS. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Ultrasound for critical care physicians: take a deep breath

    Directory of Open Access Journals (Sweden)

    Ling D

    2015-07-01

    Full Text Available No abstract available. Article truncated at 150 words. A 40 year old man with a past medical history of intravenous drug abuse presented to the emergency department with difficulty walking and lower extremity weakness. He did admit to recent heroin use. He became somnolent in the ED and was given naloxone. However, he did not improve his level of consciousness sufficiently and was intubated for hypercarbia. The patient was transferred to the MICU and was evaluated for respiratory failure. He later that day passed a spontaneous breathing trial after he awoke and was extubated. However, he was soon thereafter was re-intubated for poor respiratory efforts and a weak cough. With an unexplained etiology for the respiratory failure, CT of the head, MRI of the brain and lab evaluation were pursued but were negative. At that point, a bedside ultrasound of the right hemi-diaphragm in the zone of apposition was obtained and is shown below: Figure 1. Ultrasound of ...

  14. Rebreathing, resistance and external work of breathing in three different coaxial Mapleson D systems.

    Science.gov (United States)

    Jonsson, L O; Zetterström, H

    1989-01-01

    Using a lung model, rebreathing characteristics, resistance against gas flow and the external work of breathing were tested in three different coaxial Mapleson D systems: the Medicvent D system, the Bain original system and the Coax-II system. The rebreathing characteristics were found to be similar in all systems in both spontaneous and controlled ventilation. The Bain system was found to have the lowest resistance and work of breathing and the Coax-II system the highest. The differences were small and clinically insignificant. Both the resistance and the work of breathing increased with fresh gas flow. The resistance against expiration was found to be in the range 135-160 Pa at a total gas flow of 31 1.min-1, which is well within the acceptable level. The resulting end-expiratory pressure was never above 100 Pa (1 cmH2O) in any system. We concluded that there was no clinically significant difference among the three systems despite differences in design. The coaxial Mapleson D systems can also be used safely with high fresh gas flows with regard to resistance and end-expiratory pressures.

  15. 13C Urea Breath Testing to Diagnose Helicobacter pylori Infection in Children

    Directory of Open Access Journals (Sweden)

    Colette Deslandres

    1999-01-01

    Full Text Available The causal relationship between Helicobacter pylori colonization of the gastric mucosa and gastritis has been proven. Endoscopy and subsequent histological examination of antral biopsies have been regarded as the gold standard for diagnosing H pylori gastritis. The 13C urea breath test is a noninvasive test with a high specificity and sensitivity for H pylori colonization. Increasingly, it is becoming an important tool for use in diagnosing H pylori infection in paediatric populations. This test is particularly well suited for epidemiological studies evaluating reinfection rates, spontaneous clearance of infection and eradication rates after therapy. However, few groups have validated the test in the pediatric age group. The testing protocol has not yet been standardized. Variables include fasting state, dose of urea labelled with 13C, delta cutoff level of 13C carbon dioxide, choice of test meal and timing of collection of expired breath samples. Further studies are urgently needed to evaluate critically the impact of H pylori infection in children. The 13C urea breath test should prove very useful in such prospective studies.

  16. Ab Initio Molecular Dynamics Studies of Pb m Sb n ( m + n ≤ 9) Alloy Clusters

    Science.gov (United States)

    Song, Bingyi; Xu, Baoqiang; Yang, Bin; Jiang, Wenlong; Chen, Xiumin; Xu, Na; Liu, Dachun; Dai, Yongnian

    2017-10-01

    Structure, stability, and dynamics of Pb m Sb n ( m + n ≤ 9) clusters were investigated using ab initio molecular dynamics. Size dependence of binding energies, the second-order energy difference of clusters, dissociation energy, HOMO-LUMO gaps, Mayer bond order, and the diffusion coefficient of Pb m Sb n clusters were discussed. Results suggest that Pb3Sb2, Pb4Sb2, and Pb5Sb4 ( n = 2 or 4) clusters have higher stability than other clusters, which is consistent with previous findings. In case of Pb-Sb alloy, the dynamics results show that Pb4Sb2 (Pb-22.71 wt pct Sb) can exist in gas phase at 1073 K (800 °C), which reasonably explains the azeotropic phenomenon, and the calculated values are in agreement with the experimental results (Pb-22 wt pct Sb).

  17. Spontaneous emission by moving atoms

    International Nuclear Information System (INIS)

    Meystre, P.; Wilkens, M.

    1994-01-01

    It is well known that spontaneous emission is not an intrinsic atomic property, but rather results from the coupling of the atom to the vacuum modes of the electromagnetic field. As such, it can be modified by tailoring the electromagnetic environment into which the atom can radiate. This was already realized by Purcell, who noted that the spontaneous emission rate can be enhanced if the atom placed inside a cavity is resonant with one of the cavity is resonant with one of the cavity modes, and by Kleppner, who discussed the opposite case of inhibited spontaneous emission. It has also been recognized that spontaneous emission need not be an irreversible process. Indeed, a system consisting of a single atom coupled to a single mode of the electromagnetic field undergoes a periodic exchange of excitation between the atom and the field. This periodic exchange remains dominant as long as the strength of the coupling between the atom and a cavity mode is itself dominant. 23 refs., 6 figs

  18. Spontaneous Development of Moral Concepts

    Science.gov (United States)

    Siegal, M.

    1975-01-01

    Moral competence is more difficult to attain than scientific competence. Since language comprehension plays a central role in conceptual development, and moral language is difficult to learn, there is a common deficiency in moral conceptual development. This suggests a theory of non-spontaneous solutions to moral problems. (Author/MS)

  19. Shell theorem for spontaneous emission

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Mortensen, Jakob Egeberg; Lodahl, Peter

    2013-01-01

    and therefore is given exactly by the dipole approximation theory. This surprising result is a spontaneous emission counterpart to the shell theorems of classical mechanics and electrostatics and provides insights into the physics of mesoscopic emitters as well as great simplifications in practical calculations....

  20. Prediction of Spontaneous Preterm Birth

    NARCIS (Netherlands)

    Dijkstra, Karolien

    2002-01-01

    Preterm birth is a leading cause of neonatal morbidity and mortality. It is a major goal in obstetrics to lower the incidence of spontaneous preterm birth (SPB) and related neonatal morbidity and mortality. One of the principal objectives is to discover early markers that would allow us to identify

  1. EAMJ Dec. Spontaneous.indd

    African Journals Online (AJOL)

    2008-12-12

    Dec 12, 2008 ... surgical abortion at one month gestation without any complication. The second pregnancy which was a year prior resulted in a spontaneous miscarriage at two months followed by evacuation of retained products of conception with no post abortion complications. Antibiotics were taken following both.

  2. Spontaneous fission of superheavy nuclei

    Indian Academy of Sciences (India)

    the Yukawa-plus-exponential potential. The microscopic shell and pairing corrections are obtained using the Strutinsky and BCS approaches and the cranking formulae yield the inertia tensor. Finally, the WKB method is used to calculate penetrabilities and spontaneous fission half-lives. Calculations are performed for the ...

  3. Characterization of U-Zr fuel with alloying additive Sb for immobilizing fission product lanthanides

    Science.gov (United States)

    Xie, Yi; Benson, Michael T.; King, James A.; Mariani, Robert D.; Zhang, Jinsuo

    2018-01-01

    Fission product lanthanides can migrate to the fuel periphery and enhance fuel-cladding chemical interaction (FCCI). Adding Sb into the fuel alloy to bind lanthanides and thus to prevent lanthanides from migration has been proposed. The U-Zr fuel alloys were fabricated with compositions of U-10Zr-4.1Sb, U-10Zr-4.1Sb-4Ce, U-10Zr-2.07Sb, and U-10Zr-2.07Sb-2Ce wt.% by arc melting, and analyzed under scanning electron microscope (SEM) for the microstructure and elemental compositions. In the Ce-free alloy, Sb was found in Sb-Zr precipitates; while in the Ce-contained alloy, Sb was found in the form of intermetallic compounds Ce4Sb3 and Ce2Sb without any Sb-Zr precipitates. Antimony has the preference to bind Ce over Zr, indicating Sb can effectively prevent Ce interaction with Fe to the extent. Cerium is bound to Sb and no ternary intermetallic Ce-Sb-Zr compound was found.

  4. Photovoltaic detector based on type II heterostructure with deep AlSb/InAsSb/AlSb quantum well in the active region for the midinfrared spectral range

    International Nuclear Information System (INIS)

    Mikhailova, M. P.; Andreev, I. A.; Moiseev, K. D.; Ivanov, E. V.; Konovalov, G. G.; Mikhailov, M. Yu.; Yakovlev, Yu. P.

    2011-01-01

    Photodetectors for the spectral range 2–4 μm, based on an asymmetric type-II heterostructure p-InAs/AlSb/InAsSb/AlSb/(p, n)GaSb with a single deep quantum well (QW) or three deep QWs at the heterointerface, have been grown by metal-organic vapor phase epitaxy and analyzed. The transport, luminescent, photoelectric, current-voltage, and capacitance-voltage characteristics of these structures have been examined. A high-intensity positive and negative luminescence was observed in the spectral range 3–4 μm at high temperatures (300–400 K). The photosensitivity spectra were in the range 1.2–3.6 μm (T = 77 K). Large values of the quantum yield (η = 0.6−0.7), responsivity (S λ = 0.9−1.4 A W –1 ), and detectivity (D* λ = 3.5 × 10 11 to 10 10 cm Hz 1/2 W −1 ) were obtained at T = 77–200 K. The small capacitance of the structures (C = 7.5 pF at V = −1 V and T = 300 K) enabled an estimate of the response time of the photodetector at τ = 75 ps, which corresponds to a bandwidth of about 6 GHz. Photodetectors of this kind are promising for heterodyne detection of the emission of quantum-cascade lasers and IR spectroscopy.

  5. In vivo proton MRS of normal pancreas metabolites during breath-holding and free-breathing

    Energy Technology Data Exchange (ETDEWEB)

    Su, T.-H. [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, 95 Yong-An Road, Beijing (China); Jin, E.-H., E-mail: erhujin1@hotmail.com [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, 95 Yong-An Road, Beijing (China); Shen, H. [GE China Company Ltd, Healthcare, General Electric Company, Beijing (China); Zhang, Y.; He, W. [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, 95 Yong-An Road, Beijing (China)

    2012-07-15

    Aim: To characterize normal pancreas metabolites using in vivo proton magnetic resonance spectroscopy ({sup 1}H MRS) at 3 T under conditions of breath-holding and free-breathing. Materials and methods: The pancreases of 32 healthy volunteers were examined using {sup 1}H MRS during breath-holding and free-breathing acquisitions in a single-voxel point-resolved selective spectroscopy sequence (PRESS) technique using a 3 T MRI system. Resonances were compared between paired spectra of the two breathing modes. Furthermore, correlations between lipid (Lip) content and age, body-mass index (BMI), as well as choline (Cho) peak visibility of the normal pancreas were analysed during breath-holding. Results: Twenty-nine pairs of spectra were successfully obtained showing three major resonances, Lip, Cho, cholesterol and the unsaturated parts of the olefinic region of fatty acids (Chol + Unsat). Breath-hold spectra were generally better, with higher signal-to-noise ratios (SNR; Z=-2.646, p = 0.008) and Cho peak visible status (Z=-2.449, p = 0.014). Correlations were significant between spectra acquired by the two breathing modes, especially for Lip height, Lip area, and the area of other peaks at 1.9-4.1 ppm. However, the Lip resonance was significantly different between the spectra of the two breathing modes (p < 0.05). In the breath-holding spectra, there were significant positive correlations between Lip peak height, area, and age (r = 0.491 and 0.521, p = 0.007 and 0.004), but not between Lip peak area and BMI. There was no statistical difference in Cho resonances between males and females. The Lip peak height and area were significantly higher in the Cho peak invisible group than in the Cho peak visible group (t = 2.661 and 2.353, p = 0.030 and 0.043). Conclusion: In vivo{sup 1}H MRS of the normal pancreas at 3 T is technically feasible and can characterize several metabolites. {sup 1}H MRS during breath-holding acquisition is superior to that during free-breathing

  6. Self contained compressed air breathing apparatus to facilitate personnel decontamination

    International Nuclear Information System (INIS)

    McDonald, C.W.

    1963-11-01

    This report describes the modification of a Self Contained Compressed Air Breathing Apparatus to provide extended respiratory protection to grossly contaminated personnel during a decontamination period which may exceed the duration of the Breathing Apparatus air supply. (author)

  7. Ion beam synthesis of Mn/Sb clusters in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Steinert, M; Wesch, W [Institut fuer Festkoerperphysik, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Undisz, A; Rettenmayr, M [Institut fuer Materialwissenschaft und Werkstofftechnologie, Friedrich-Schiller-Universitaet Jena, 07743 Jena (Germany); Nunes, W C; Borges, R P; Godinho, M [Centro de Fisica da Materia Condensada, Universidade de Lisboa, 1749-016 Lisboa (Portugal); Rubinger, R M; Carmo, M C; Sobolev, N A, E-mail: michael.steinert@uni-jena.d, E-mail: werner.wesch@uni-jena.d [Departamento de Fisica and I3N, Universidade de Aveiro, 3810-193 Aveiro (Portugal)

    2009-02-07

    In order to investigate the formation of Mn/Sb clusters embedded in crystalline silicon, sequential ion implantation with fluences of 1 x 10{sup 16} at cm{sup -2} and 2 x 10{sup 16} at cm{sup -2}, respectively, was used to incorporate Mn and Sb ions at high concentrations into Si(0 0 1). Based on investigations with Rutherford backscattering spectroscopy (RBS) and corresponding channelling measurements (RBS/c), we report on a temperature dependent redistribution of the implanted species during the rapid thermal annealing process governed by the radiation-induced defects. Additionally performed cross-sectional TEM analyses, including EDX measurements, clearly show the presence of hexagonal shaped elementary Sb precipitates as well as compound clusters consisting of Mn and Sb, which are aligned to the crystal structure of the host silicon. In electron magnetic resonance measurements many samples exhibit broad resonance bands persisting up to approximately 60 K. For out-of-plane rotations, the bands show a weak angular dependence of the resonance field but a strong angular dependence of the intensity. Zero-field-cooled and field-cooled magnetization curves were measured on selected samples with a SQUID magnetometer between 10 and 400 K at different applied fields. The curves show a weak magnetic signal generated by different magnetic phases while at least one can be ascribed to superparamagnetic nanoparticles of MnSb.

  8. The growth of GaSb/Al{sub 0.33}Ga{sub 0.67}Sb MQW on n-Silicon (1 0 0) with Al{sub 0.66}Ga{sub 0.34}Sb/AlSb SPS layers

    Energy Technology Data Exchange (ETDEWEB)

    Yoen, Kyu Hyoek [Nano-Electronic Engineering, University of Science Technology, Daejeon 305-350 (Korea, Republic of); Center for Opto-Electronic Convergence Systems, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Song, Jin Dong, E-mail: jdsong@kist.re.kr [Nano-Electronic Engineering, University of Science Technology, Daejeon 305-350 (Korea, Republic of); Center for Opto-Electronic Convergence Systems, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Lee, Eun Hye [Center for Opto-Electronic Convergence Systems, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Jang, Hye Joung [Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Bae, Min Han; Kim, Jun Young; Han, Il Ki; Choi, Won Jun [Center for Opto-Electronic Convergence Systems, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of)

    2014-09-15

    Highlights: • GaSb/Al{sub 0.33}GaSb MQW layer was grown on Si (1 0 0) by MBE. • The effect of miscut angle of Si substrate was studied. • A lot of twins were removed by Al{sub 0.66}Ga{sub 0.34}Sb/AlSb SPS layers. • Good quality of GaSb/Al{sub 0.33}Ga{sub 0.67}Sb MQW layers were proved by PL spectra. • Optimum growth temperature of the AlSb buffer layer was studied. - Abstract: GaSb/Al{sub 0.33}Ga{sub 0.67}Sb multi-quantum well (MQW) film on n-Si (1 0 0) substrates is grown by molecular beam epitaxy. The effects of a miscut angle of the Si substrate (0°, 5°, and 7°) on the properties of an AlSb layer were also studied. The suppression of the anti-phase domains (APD) was observed at a miscut angle of 5° on Si (1 0 0). It was found that the growth temperature in the range of 510–670 °C affects the quality of AlSb layers on Si. Low root-mean-square surface (RMS) roughness values of 3–5 nm were measured by atomic force microscopy at growth temperatures ranging from 550 °C to 630 °C. In addition, Al{sub 0.66}Ga{sub 0.34}Sb/AlSb short period superlattice (SPS) layers were used to overcome problems associated with a large lattice mismatch. The RMS values of samples with a SPS were partially measured at approximately ∼1 nm, showing a larger APD surface area than samples without a SPS layer. Bright-field cross-sectional transmission electron microscopy images of the GaSb/Al{sub 0.33}Ga{sub 0.67}Sb MQW, the AlSb buffer layer and the Al{sub 0.66}Ga{sub 0.34}Sb/AlSb SPS layers show that numerous twins from the AlSb/Si interface were removed by the AlSb buffer layer and the Al{sub 0.66}Ga{sub 0.34}Sb/AlSb SPS. The GaSb/Al{sub 0.33}Ga{sub 0.67}Sb MQW PL spectra were obtained at 300 K and 10 K with a fixed excitation power of 103 mW. Emission peaks appeared at 1758 nm and 1620 nm, respectively.

  9. Iron and zinc levels in breath-holding spells

    OpenAIRE

    DEDA, Gülhis; AKAR, M. Nejat; CİN, Şükrü; GENÇGÖNÜL, Handan

    2002-01-01

    Breath-Holding spells are a dramatic and commonly observed clinical phenomenon in childhood. The underlyingpathophysiologic mechanisms in breath-holding spells are result from autonomic nervous system dysregulation.Cerebral anoxia is the ultimate factor responsible for the loss of consciousness observed in the severe forms of breath-holding spells.It’s known that, there is relationbetween breath-holding spells and iron-deficiency anemia, and the spells resolve after oral iron supplemantation....

  10. Spontaneous Retropharyngeal Emphysema: A Case Report | Chi ...

    African Journals Online (AJOL)

    ... is a rare clinical condition in pediatric otolaryngology. The predominant symptoms are sore throat, odynophagia, dysphagia, and neck pain. Here, we report a case of spontaneous retropharyngeal emphysema. Keywords: Iatrogenic injury, retropharyngeal emphysema, spontaneous retropharyngeal emphysem, trauma ...

  11. La maladie de Grisel : Spontaneous atlantoaxial subluxation

    NARCIS (Netherlands)

    Meek, MF; Robinson, PH; Hermens, RAEC

    Objective: "La maladie de Grisel" (Grisel's syndrome) is a spontaneously occurring atlantoaxial subluxation with torticollis. We present a case of atlantoaxial subluxation occurring in a 20-year period of pharyngoplasty surgery. The occurrence of a "spontaneous" atlantoaxial subluxation after oral

  12. Oral breathing and speech disorders in children.

    Science.gov (United States)

    Hitos, Silvia F; Arakaki, Renata; Solé, Dirceu; Weckx, Luc L M

    2013-01-01

    To assess speech alterations in mouth-breathing children, and to correlate them with the respiratory type, etiology, gender, and age. A total of 439 mouth-breathers were evaluated, aged between 4 and 12 years. The presence of speech alterations in children older than 5 years was considered delayed speech development. The observed alterations were tongue interposition (TI), frontal lisp (FL), articulatory disorders (AD), sound omissions (SO), and lateral lisp (LL). The etiology of mouth breathing, gender, age, respiratory type, and speech disorders were correlated. Speech alterations were diagnosed in 31.2% of patients, unrelated to the respiratory type: oral or mixed. Increased frequency of articulatory disorders and more than one speech disorder were observed in males. TI was observed in 53.3% patients, followed by AD in 26.3%, and by FL in 21.9%. The co-occurrence of two or more speech alterations was observed in 24.8% of the children. Mouth breathing can affect speech development, socialization, and school performance. Early detection of mouth breathing is essential to prevent and minimize its negative effects on the overall development of individuals. Copyright © 2013 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  13. Application of stable isotope to breath test

    International Nuclear Information System (INIS)

    Sasaki, Yasuto

    1988-01-01

    Needles to say, radioisotopes have good characteristics as a tracer for examining biological functions. In fact, scyntigraphy is widely used over Japan. It is true, however, that there are some difficulties in applying radioisotopes to humans. Thus, greater attention began to be attracted to stable isotopes in the late 1960s, because these substances can be used for infants and pregnant women. They can be stored for a long period of time since they do not suffer damping as in the case of radioisotopes. In addition to serving as a tracer, stable isotopes can provide structural-chemical information including the position of isotope labels, and the mass and atomic composition of fragment ions. Such techniques as NMR spectroscopy is employed for this purpose. The method is currently used to perform examinations of congenital metabolic disorders. The carbon isotopes of 13 C and 14 C are used for breath test. Compounds labeled with these isotopes are administered and their ratio to the total CO 2 in breath is measured to diagnose diseases. In the early 1970s, 13 C has come into use for breath test. Similar breath test is applied to diagnosis of the bacterial overgrowth syndrome and ileal dysfunction syndrome. (Nogami, K.)

  14. Multi-layered breathing architectural envelope

    DEFF Research Database (Denmark)

    Lund Larsen, Andreas; Foged, Isak Worre; Jensen, Rasmus Lund

    2014-01-01

    A multi layered breathing envelope is developed as a method of natural ventilation. The two main layers consist of mineral wool and air permeable concrete. The mineral wool works as a dynamic insulation and the permeable concrete as a heat recovery system with a high thermal mass for heat storage...

  15. Extreme breathing excitations of atomic nuclei

    International Nuclear Information System (INIS)

    Antonov, A.N.; Nikolaev, V.A.; Petkov, I.Zh.

    1984-01-01

    In the present paper collective breathing nuclear states, that appear in the framework of the coherent density fluctuation model (CFM) are taken into consideration. Their excitation energies are large and comparable with the binding nuclear energies. The basic CFM equation obtain in the generator-coordinate method. The possible mechanisms for the excitations for the excitations of the breathing states are deeply inelastic interactions of particles (e - , p, etc.) with nuclei, the π - -absorbtion from nuclei. It should be noted, that the energy of the Roper-resonance is comparable with the breathing nuclear excitation energies. Therefore the decay of this resonance, in principle, can lead to the breathing nuclear vibrations. The results of this work, as well as the results of some papers, obtained by means of a similar method but related to different quantum-mechanical systems, give an evidence, that the structure in detail and the character of the forces between the particles are not decisive for the considered type of excitations

  16. Pulmonary Function Responses to Active Cycle Breathing ...

    African Journals Online (AJOL)

    Chronic heart failure patients experience restrictive respiratory dysfunction, resulting in alterations of FEV1, FVC and FEV /FVC as demonstrated in exercise 1 intolerance, dyspnoea and poor quality of life (QoL). Active Cycle of Breathing Techniques (ACBT) is traditionally used by Physiotherapists in the management of ...

  17. Practical recommendations for breathing-adapted radiotherapy

    International Nuclear Information System (INIS)

    Simon, L.; Giraud, P.; Rosenwald, J.C.; Dumas, J.L.; Lorchel, F.; Marre, D.; Dupont, S.; Varmenot, N.; Ginestet, C.; Caron, J.; Marchesi, V.; Ferreira, I.; Garcia, R.

    2007-01-01

    Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath-hold techniques or respiration synchronized gating techniques. Breath-hold techniques can be achieved with active techniques, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily holds his/her breath. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. This work summarizes the different experiences of the centers of the STIC 2003 project. It describes the different techniques, gives an overview of the literature and proposes a practice based on our experience. (authors)

  18. CONTINUOUS EXHALED BREATH ANALYSIS ON THE ICU

    International Nuclear Information System (INIS)

    Bos, Lieuwe D. J.; Sterk, Peter J.; Schultz, Marcus J.

    2011-01-01

    During admittance to the ICU, critically ill patients frequently develop secondary infections and/or multiple organ failure. Continuous monitoring of biological markers is very much needed. This study describes a new method to continuously monitor biomarkers in exhaled breath with an electronic nose.

  19. Breathing easier: Indonesia works towards cleaner air

    International Nuclear Information System (INIS)

    Madsen, Michael Amdi

    2015-01-01

    Indonesians can look forward to breathing cleaner air following upcoming changes in regulations introduced as a result of a study conducted using nuclear analytical techniques. Lead pollution and other fine particulate matter in the air is now, for the first time, being accurately monitored and is giving Indonesian officials a good understanding of their air pollution problem and how to manage it.

  20. ACTIVE CYCLE BREATHING TECHNIQUES IN HEART FAILURE ...

    African Journals Online (AJOL)

    RICHY

    47. Pulmonary Function Responses to Active Cycle. Breathing Techniques in Heart Failure Patients at the. University Teaching Hospital (UTH), Lusaka, Zambia. 1. 1. 2. 3. Charity Kapenda Muselema *, Methuselah Jere , Gershom Chongwe , Fastone M. Goma. 1Ministry of Community Development Mother and Child Health, ...

  1. A breath actuated dry powder inhaler

    NARCIS (Netherlands)

    de Boer, Anne; Frijlink, Henderik W.; Hagedoorn, Paul

    2015-01-01

    A breath actuated dry powder inhaler with a single air circulation chamber for de-agglomeration of entrained powdered medicament using the energy of the inspiratory air stream. The chamber has a substantially polygonal sidewall, a plurality of air supply channels entering the chamber substantially

  2. New magnetic semiconductors CuCr1.5+xSb0.5-xS4 (0<=x<=0.3)

    Science.gov (United States)

    Saifullaeva, Dilaram; Solieva, Shahlo; Muminov, Asamat

    2002-11-01

    New compounds with spinel structure CuCr1.5+xSb0.5-xS4(0semiconductores. The compounds (0<=x<=0.1) were found to have the magnetic properties characteristic for antiferromagnets. Compounds (0.2<=x<=0.3) have a spontaneous magnetization, with the Curie point of the compound with x=0.3, Tc = 334 K, being higher than room temperature. The re-entrant spin glass transition is observed in the compounds with x=0.17;0.2)

  3. The use of active breathing control (ABC) to reduce margin for breathing motion

    International Nuclear Information System (INIS)

    Wong, John W.; Sharpe, Michael B.; Jaffray, David A.; Kini, Vijay R.; Robertson, John M.; Stromberg, Jannifer S.; Martinez, Alavro A.

    1999-01-01

    Purpose: For tumors in the thorax and abdomen, reducing the treatment margin for organ motion due to breathing reduces the volume of normal tissues that will be irradiated. A higher dose can be delivered to the target, provided that the risk of marginal misses is not increased. To ensure safe margin reduction, we investigated the feasibility of using active breathing control (ABC) to temporarily immobilize the patient's breathing. Treatment planning and delivery can then be performed at identical ABC conditions with minimal margin for breathing motion. Methods and Materials: An ABC apparatus is constructed consisting of 2 pairs of flow monitor and scissor valve, 1 each to control the inspiration and expiration paths to the patient. The patient breathes through a mouth-piece connected to the ABC apparatus. The respiratory signal is processed continuously, using a personal computer that displays the changing lung volume in real-time. After the patient's breathing pattern becomes stable, the operator activates ABC at a preselected phase in the breathing cycle. Both valves are then closed to immobilize breathing motion. Breathing motion of 12 patients were held with ABC to examine their acceptance of the procedure. The feasibility of applying ABC for treatment was tested in 5 patients by acquiring volumetric scans with a spiral computed tomography (CT) scanner during active breath-hold. Two patients had Hodgkin's disease, 2 had metastatic liver cancer, and 1 had lung cancer. Two intrafraction ABC scans were acquired at the same respiratory phase near the end of normal or deep inspiration. An additional ABC scan near the end of normal expiration was acquired for 2 patients. The ABC scans were also repeated 1 week later for a Hodgkin's patient. In 1 liver patient, ABC scans were acquired at 7 different phases of the breathing cycle to facilitate examination of the liver motion associated with ventilation. Contours of the lungs and livers were outlined when applicable

  4. Human respiratory deposition of particles during oronasal breathing

    Science.gov (United States)

    Swift, David L.; Proctor, Donald F.

    Deposition of particles in the tracheobronchial and pulmonary airways is computed as a function of particle size, correcting for deposition in the parallel nasal and oral airways with oronasal breathing. Thoracic deposition is lower at all sizes for oronasal breathing than for mouth breathing via tube, and is negligible for aerodynamic equivalent diameters of 10 μm or larger.

  5. Oral Breathing Challenge in Participants with Vocal Attrition

    Science.gov (United States)

    Sivasankar, Mahalakshmi; Fisher, Kimberly V.

    2003-01-01

    Vocal folds undergo osmotic challenge by mouth breathing during singing, exercising, and loud speaking. Just 15 min of obligatory oral breathing, to dry the vocal folds, increases phonation threshold pressure (P[subscript th]) and expiratory vocal effort in healthy speakers (M. Sivasankar & K. Fisher, 2002). We questioned whether oral breathing is…

  6. 21 CFR 868.5240 - Anesthesia breathing circuit.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthesia breathing circuit. 868.5240 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5240 Anesthesia breathing circuit. (a) Identification. An anesthesia breathing circuit is a device that is intended to administer medical gases to a...

  7. 46 CFR 108.703 - Self-contained breathing apparatus.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Self-contained breathing apparatus. 108.703 Section 108... DESIGN AND EQUIPMENT Miscellaneous Equipment § 108.703 Self-contained breathing apparatus. (a) Each unit must be equipped with a self-contained breathing apparatus described in § 108.497(a) to use as...

  8. 46 CFR 197.340 - Breathing gas supply.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Breathing gas supply. 197.340 Section 197.340 Shipping... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.340 Breathing gas supply. (a) A primary breathing gas supply for surface-supplied diving must be sufficient to support the following for the...

  9. 21 CFR 868.5330 - Breathing gas mixer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breathing gas mixer. 868.5330 Section 868.5330...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5330 Breathing gas mixer. (a) Identification. A breathing gas mixer is a device intended for use in conjunction with a respiratory support...

  10. 46 CFR 197.450 - Breathing gas tests.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Breathing gas tests. 197.450 Section 197.450 Shipping....450 Breathing gas tests. The diving supervisor shall insure that— (a) The output of each air... or modification. (b) Purchased supplies of breathing mixtures supplied to a diver are checked before...

  11. 42 CFR 84.132 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.132 Section 84.132 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL... Respirators § 84.132 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with...

  12. 42 CFR 84.1132 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.1132 Section 84.1132 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL... Gas Masks § 84.1132 Breathing tubes; minimum requirements. (a) Flexible breathing tubes used in...

  13. 42 CFR 84.195 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.195 Section 84.195 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL... Cartridge Respirators § 84.195 Breathing tubes; minimum requirements. Flexible breathing tubes used in...

  14. 46 CFR 169.736 - Self-contained breathing apparatus.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Self-contained breathing apparatus. 169.736 Section 169... VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.736 Self-contained breathing apparatus. Each locker or space containing self-contained breathing apparatus must be marked “SELF-CONTAINED...

  15. 46 CFR 154.1852 - Air breathing equipment.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Air breathing equipment. 154.1852 Section 154.1852... STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Operations § 154.1852 Air breathing equipment. (a) The master shall ensure that a licensed officer inspects the compressed air breathing...

  16. 42 CFR 84.172 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.172... Air-Purifying Particulate Respirators § 84.172 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with respirators shall be designed and constructed to prevent: (a...

  17. 46 CFR 108.635 - Self-contained breathing apparatus.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Self-contained breathing apparatus. 108.635 Section 108... DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.635 Self-contained breathing apparatus. Each locker or space containing self-contained breathing apparatus must be marked: “SELF CONTAINED...

  18. The response of the vena cava to abdominal breathing.

    Science.gov (United States)

    Byeon, Kyeongmin; Choi, Jin-Oh; Yang, Jeong Hoon; Sung, Jidong; Park, Seung Woo; Oh, Jae K; Hong, Kyung Pyo

    2012-02-01

    Recently, abdominal-breathing or diaphragmatic-breathing methods have increased in popularity. Little is known how abdominal breathing affects the circulatory system. This study was designed to determine the impact of the respiratory pattern on central venous flow using echocardiography. The superior vena cava (SVC) and inferior vena cava (IVC) were observed in people who had practiced abdominal breathing for at least 2 years, while they were breathing in three different techniques: slow respiration, slow respiration with inspiratory pause, or normal respiration. In addition, the observation during normal respiration was compared with that of a control group. The abdominal-breathing group consisted of 20 people with mean duration of training of 9.6 years. The respiratory collapsibility index of IVC during slow respiration with inspiratory pause was 62±19% compared with 48±19% during normal respiration (p=0.012) in the abdominal-breathing group. The abdominal-breathing group had a higher IVC collapsibility index compared to the control group during normal respiration (48±19% versus 26±12%, pbreathing patterns or between groups. The IVC of people who practice abdominal breathing has a greater degree of collapse than those of normal people, suggesting that abdominal-breathing exercise can positively affect venous return via IVC. For those who practice abdominal breathing, the collapsibility of the IVC is the best during slow respiration with inspiratory pause. The SVC did not seem to be affected by abdominal-breathing training.

  19. 42 CFR 84.115 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.115 Section 84.115 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL... § 84.115 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with gas...

  20. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air respirators shall employ one or two flexible breathing tubes of the nonkinking type which extend from the...

  1. 14 CFR 29.1439 - Protective breathing equipment.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Protective breathing equipment. 29.1439... Protective breathing equipment. (a) If one or more cargo or baggage compartments are to be accessible in flight, protective breathing equipment must be available for an appropriate crewmember. (b) For...

  2. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be measured in the facepiece or mouthpiece of a gas mask mounted on a breathing machine both before and after...

  3. IMPLICATIONS OF MOUTH BREATHING AND ATYPICAL SWALLOWING IN BODY POSTURE

    Directory of Open Access Journals (Sweden)

    Veronique Sousa

    2017-07-01

    Conclusion: Statistically significant associations were established between the breathing pattern and the horizontal alignment of acromions, as well as the horizontal and vertical alignment of the head; between the pattern of breathing and swallowing with occlusal relationship anteroposterior and occlusal relationship vertical and also between breathing pattern and swallowing with digital sucking habits and pacifier use.

  4. 21 CFR 862.3050 - Breath-alcohol test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breath-alcohol test system. 862.3050 Section 862...) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test Systems § 862.3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened...

  5. The best breathing command for abdominal PETCT

    International Nuclear Information System (INIS)

    Berthold, T.; Goerres, G.; Burger, C.

    2002-01-01

    Aim: To evaluate the best breathing command for combined PETCT scanning on a in-line system (Discovery LS, GEMS). Material and Methods: Eight patients underwent FDG PET and CT for attenuation correction and image co-registration on a combined PETCT scanner. CT was acquired during maximum inspiration (MaxInsp) with a starting point at the level of the head. Patients kept their breath for approximately 20 seconds. Then, a CT scan was acquired during normal expiration (NormExp), which corresponded to the respiratory level reached when the patient first inhaled and then exhaled without forcing expiration. Again, CT started at the head and patients kept their breath for approximately 20 seconds. In a third run, patients performed again the NormExp breathing manoeuvre but the breathing command was given after the start of the CT scan. Using this respiration protocol, the hold on time for the patients was between 10 and 15 seconds. All PET images were corrected for attenuation using the CT-based attenuation maps acquired with these three respiration protocols and then were reconstructed using an iterative algorithm. Results: In all patients, attenuation correction of the PET image using the CT scan acquired during MaxInsp caused mis-correction, which mimicked a decrease of FDG concentration in the base of the lungs. During MaxInsp the upper abdominal organs change their position and air filling of the lower lung zone is increased, thus, causing an underestimation of correction values. Subtraction images of the CT scans acquired during MaxInsp and NormExp illustrate the range of organ movements. Subtraction images of the attenuation corrected PET scans illustrate the deterioration of the final PET image. CT acquisition during NormExp provides better PET and co-registered PET/CT images. Using the shorter breath hold time the visual image quality was good in all patients. Conclusion: CT based attenuation correction can severely deteriorate PET image quality, if the CT scan

  6. Effects upon metabolic pathways and energy production by Sb(III) and As(III)/Sb(III)-oxidase gene aioA in Agrobacterium tumefaciens GW4.

    Science.gov (United States)

    Li, Jingxin; Yang, Birong; Shi, Manman; Yuan, Kai; Guo, Wei; Li, Mingshun; Wang, Gejiao

    2017-01-01

    Agrobacterium tumefaciens GW4 is a heterotrophic arsenite [As(III)]/antimonite [Sb(III)]-oxidizing strain. The As(III) oxidase AioAB is responsible for As(III) oxidation in the periplasm and it is also involved in Sb(III) oxidation in Agrobacterium tumefaciens 5A. In addition, Sb(III) oxidase AnoA and cellular H2O2 are also responsible for Sb(III) oxidation in strain GW4. However, the deletion of aioA increased the Sb(III) oxidation efficiency in strain GW4. In the present study, we found that the cell mobility to Sb(III), ATP and NADH contents and heat release were also increased by Sb(III) and more significantly in the aioA mutant. Proteomics and transcriptional analyses showed that proteins/genes involved in Sb(III) oxidation and resistance, stress responses, carbon metabolism, cell mobility, phosphonate and phosphinate metabolism, and amino acid and nucleotide metabolism were induced by Sb(III) and were more significantly induced in the aioA mutant. The results suggested that Sb(III) oxidation may produce energy. In addition, without periplasmic AioAB, more Sb(III) would enter bacterial cells, however, the cytoplasmic AnoA and the oxidative stress response proteins were significantly up-regulated, which may contribute to the increased Sb(III) oxidation efficiency. Moreover, the carbon metabolism was also activated to generate more energy against Sb(III) stress. The generated energy may be used in Sb transportation, DNA repair, amino acid synthesis, and cell mobility, and may be released in the form of heat.

  7. Effects upon metabolic pathways and energy production by Sb(III and As(III/Sb(III-oxidase gene aioA in Agrobacterium tumefaciens GW4.

    Directory of Open Access Journals (Sweden)

    Jingxin Li

    Full Text Available Agrobacterium tumefaciens GW4 is a heterotrophic arsenite [As(III]/antimonite [Sb(III]-oxidizing strain. The As(III oxidase AioAB is responsible for As(III oxidation in the periplasm and it is also involved in Sb(III oxidation in Agrobacterium tumefaciens 5A. In addition, Sb(III oxidase AnoA and cellular H2O2 are also responsible for Sb(III oxidation in strain GW4. However, the deletion of aioA increased the Sb(III oxidation efficiency in strain GW4. In the present study, we found that the cell mobility to Sb(III, ATP and NADH contents and heat release were also increased by Sb(III and more significantly in the aioA mutant. Proteomics and transcriptional analyses showed that proteins/genes involved in Sb(III oxidation and resistance, stress responses, carbon metabolism, cell mobility, phosphonate and phosphinate metabolism, and amino acid and nucleotide metabolism were induced by Sb(III and were more significantly induced in the aioA mutant. The results suggested that Sb(III oxidation may produce energy. In addition, without periplasmic AioAB, more Sb(III would enter bacterial cells, however, the cytoplasmic AnoA and the oxidative stress response proteins were significantly up-regulated, which may contribute to the increased Sb(III oxidation efficiency. Moreover, the carbon metabolism was also activated to generate more energy against Sb(III stress. The generated energy may be used in Sb transportation, DNA repair, amino acid synthesis, and cell mobility, and may be released in the form of heat.

  8. Deep Breathing Improves End-Tidal Carbon Dioxide Monitoring of an Oxygen Nasal Cannula-Based Capnometry Device in Subjects Extubated After Abdominal Surgery.

    Science.gov (United States)

    Takaki, Shunsuke; Mizutani, Kenji; Fukuchi, Moeka; Yoshida, Tasuku; Idei, Masahumi; Matsuda, Yuko; Yamaguchi, Yoshikazu; Miyashita, Tetsuya; Nomura, Takeshi; Yamaguchi, Osamu; Goto, Takahisa

    2017-01-01

    Capnometry detects hypoventilation earlier than pulse oximetry while supplemental oxygen is being administered. We compared the end-tidal CO 2 (P ETCO 2 ) measured using a newly developed oxygen nasal cannula with a CO 2 -sampling port and the P aCO 2 in extubated subjects after abdominal surgery. We also investigated whether the difference between P aCO 2 and P ETCO 2 is affected by resting, by spontaneous breathing with the mouth consciously closed, and by deep breathing with the mouth closed. Adult post-abdominal surgery subjects admitted to the ICU were enrolled. After extubation, oxygen was supplied at 4 L/min using a capnometry-type oxygen cannula. The breathing frequency, P ETCO 2 , and P aCO 2 were measured after 30 min of oxygen supplementation. P ETCO 2 was continuously measured during rest, during breathing with the mouth consciously closed, and during deep breathing with the mouth closed. The difference between P ETCO 2 and P aCO 2 during various breathing patterns was analyzed using the Bland-Altman method. Twenty subjects were included. The bias ± SD (limits of agreement) for breathing frequency measured by capnometry compared with those obtained by direct measurement was 0.4 ± 3.6 (-6.7 to 7.4). In P ETCO 2 compared with P aCO 2 , the biases (limits of agreement) were 14.8 ± 8.2 (-1.3 to 30.9) at rest, 10.2 ± 6.4 (-2.3 to 22.7) with the mouth closed, and 7.7 ± 5.6 (-3.2 to 18.6) for deep breathing with the mouth closed. P ETCO 2 determined using the capnometry device yielded unreliable and widely ranging values under various breathing patterns. However, deep breathing with the mouth closed decreased the difference between P ETCO 2 and P aCO 2 , as compared with other breathing patterns. P ETCO 2 measurements under deep breathing with mouth closed with a capnometry-type oxygen cannula improved the prediction of the absolute value of P aCO 2 in extubated post-abdominal surgical subjects without respiratory dysfunction. Copyright © 2017 by

  9. Quaternary InGaAsSb Thermophotovoltaic Diode Technology

    Energy Technology Data Exchange (ETDEWEB)

    M Dashiell; J Beausang; H Ehsani; G Nichols; D DePoy; L Danielson; P Talamo; K Rahner; E Brown; S Burger; P Fourspring; W Topper; P Baldasaro; C Wang; R Huang; M Connors; G Turner; Z Shellenbarger; G Taylor; Jizhong Li; R Martinelli; D Donetski; S Anikeev; G Belenky; S Luryl

    2005-01-26

    Thermophotovoltaic (TPV) diodes fabricated from InGaAsSb alloys lattice-matched to GaSb substrates are grown by Metal Organic Vapor Phase Epitaxy (MOVPE). 0.53eV InGaAsSb TPV diodes utilizing front-surface spectral control filters have been tested in a vacuum cavity and a TPV thermal-to-electric conversion efficiency ({eta}{sub TPV}) and a power density (PD) of {eta}{sub TPV} = 19% and PD=0.58 W/cm{sup 2} were measured for T{sub radiator} = 950 C and T{sub diode} = 27 C. Recombination coefficients deduced from minority carrier measurements and the theory reviewed in this article predict a practical limit to the maximum achievable conversion efficiency and power density for 0.53eV InGaAsSb TPV. The limits for the above operating temperatures are projected to be {eta}{sub TPV} = 26% and PD = 0.75 W/cm{sup 2}. These limits are extended to {eta}{sub TPV} = 30% and PD = 0.85W/cm{sup 2} if the diode active region is bounded by a reflective back surface to enable photon recycling and a two-pass optical path length. The internal quantum efficiency of the InGaAsSb TPV diode is close to the theoretically predicted limits, with the exception of short wavelength absorption in GaSb contact layers. Experiments show that the open circuit voltage of the 0.53eV InGaAsSb TPV diodes is not strongly dependent on the device architectures studied in this work where both N/P and P/N double heterostructure diodes have been grown with various acceptor and donor doping levels, having GaSb and AlGaAsSb confinement, and also partial back surface reflectors. Lattice matched InGaAsSb TPV diodes were fabricated with bandgaps ranging from 0.6 to 0.5eV without significant degradation of the open circuit voltage factor, quantum efficiency, or fill factor as the composition approached the miscibility gap. The key diode performance parameter which is limiting efficiency and power density below the theoretical limits in InGaAsSb TPV devices is the open circuit voltage. The open circuit voltages of

  10. Extremely large magnetoresistance and electronic structure of TmSb

    Science.gov (United States)

    Wang, Yi-Yan; Zhang, Hongyun; Lu, Xiao-Qin; Sun, Lin-Lin; Xu, Sheng; Lu, Zhong-Yi; Liu, Kai; Zhou, Shuyun; Xia, Tian-Long

    2018-02-01

    We report the magnetotransport properties and the electronic structure of TmSb. TmSb exhibits extremely large transverse magnetoresistance and Shubnikov-de Haas (SdH) oscillation at low temperature and high magnetic field. Interestingly, the split of Fermi surfaces induced by the nonsymmetric spin-orbit interaction has been observed from SdH oscillation. The analysis of the angle-dependent SdH oscillation illustrates the contribution of each Fermi surface to the conductivity. The electronic structure revealed by angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations demonstrates a gap at the X point and the absence of band inversion. Combined with the trivial Berry phase extracted from SdH oscillation and the nearly equal concentrations of electron and hole from Hall measurements, it is suggested that TmSb is a topologically trivial semimetal and the observed XMR originates from the electron-hole compensation and high mobility.

  11. Radiation-modified structure of Ge25Sb15S60 and Ge35Sb5S60 glasses

    Science.gov (United States)

    Kavetskyy, T.; Shpotyuk, O.; Kaban, I.; Hoyer, W.

    2008-06-01

    Atomic structures of Ge25Sb15S60 and Ge35Sb5S60 glasses are investigated in the γ-irradiated and annealed after γ-irradiation states by means of high-energy synchrotron x-ray diffraction technique. The first sharp diffraction peak (FSDP) is detected at around 1.1 A˚-1 in the structure factors of both alloys studied. The FSDP position is found to be stable for radiation/annealing treatment of the samples, while the FSDP intensity shows some changes between γ-irradiated and annealed states. The peaks in the pair distribution functions observed between 2 and 4 A˚ are related to the Ge-S, Ge-Sb, and Sb-Sb first neighbor correlations and Ge-Ge second neighbor correlations in the edge-shared GeS4/2 tetrahedra, and S-S and/or Ge-Ge second neighbor correlations in the corner-shared GeS4/2 tetrahedra. Three mechanisms of the radiation-/annealing-induced changes are discussed in the framework of coordination topological defect formation and bond-free solid angle concepts.

  12. Growth and characterization of AlInAsSb layers lattice-matched to GaSb

    Science.gov (United States)

    Tournet, J.; Rouillard, Y.; Tournié, E.

    2017-11-01

    We report on the growth by solid-source MBE of random-alloy AlxIn1-xAsySb1-y layers lattice-matched to (0 0 1)-GaSb substrates, with xAl ∈ [0.25; 0.75]. The samples quality and morphology were characterized by X-ray diffraction, Nomarski microscopy and atomic force microscopy. Layers grown at 400 °C demonstrated smooth surfaces and no sign of phase decomposition. Samples with xAl ≤ 0.60 demonstrated photoluminescence (PL) at 300 K whereas samples with higher Al content only demonstrated PL at low temperature. Samples grown at 430 °C, in contrast, exhibited PL at low temperature only, whatever their composition. Inferred bandgap energies corroborate the estimation of a non-null quaternary bowing parameter made by Donati, Kaspi and Malloy in Journal of Applied Physics 94 (2003) 5814. Upon annealing, the PL peak energies increased, getting even closer to the theoretical values. These results are in agreement with recently published results on digital AlInAsSb alloys. Our work, which reports the first evidence for PL emission from random-alloy AlInAsSb layers lattice-matched to GaSb, opens the way to their use in optoelectronic devices.

  13. Nocturnal breathing in cyanotic congenital heart disease.

    Science.gov (United States)

    Legault, Sylvie; Lanfranchi, Paola; Montplaisir, Jacques; Nielsen, Tore; Dore, Annie; Khairy, Paul; Marcotte, François; Mercier, Lise-Andrée

    2008-08-18

    Sleep disordered breathing is frequently observed in patients with cardiovascular disease. Even in the absence of heart disease, acute and chronic hypoxia have been shown to promote sleep-related periodic breathing with central apnea characterized by a repetitive reduction or lack of respiratory activity. Cyanotic congenital heart disease (CCHD) is associated with chronic hypoxia, regardless of whether an increase in pulmonary artery pressures coexists. Sleep aggravated hypoxia has been observed in many such patients, but it remains to be determined whether sleep disordered breathing is contributory. We, therefore, sought to assess sleep-related breathing pattern in patients with CCHD. Adults with CCHD, resting arterial oxygen saturation 40% were prospectively enrolled in a cross-sectional study. To assess sleep and respiratory indices, subjects underwent a standardized clinical appraisal that included arterial blood gas analysis and a comprehensive sleep study with an ambulatory device. An apnea-hypopnea index (AHI) >or=5/h was considered to indicate sleep apnea. Ten adults with CCHD, aged 38+/-11 years, completed the study. Seven patients had elevated pulmonary artery pressures, with a mean systolic pressure of 86.3+/-18.1 mm Hg. All patients demonstrated normal sleep parameters. Oxygen saturation further declined in 5 patients during sleep. However, no associated alteration in respiratory parameters was observed and no significant arrhythmia. The mean AHI was 1.1+/-1.0/h. No subject met the pre-defined criterion for sleep apnea. Although further oxygen desaturation may be observed during sleep in patients with CCHD, it occurs in the absence of sleep disordered breathing.

  14. Enhanced Li- and Na-storage in Sb-Graphene nanocomposite anodes

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Yeongjae; Shim, Hyun-Woo; Seo, Seung-Deok [School of Civil, Environmental and Architectural Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Dar, Mushtaq Ahmad [Center of Excellence for Research in Engineering Materials, Advanced Manufacturing Institute, King Saud University,Riyadh 11421 (Saudi Arabia); Kim, Dong-Wan, E-mail: dongwan1@empal.com [School of Civil, Environmental and Architectural Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

    2016-04-15

    Highlights: • Antimony-graphene nanocomposite (Sb-GNP) was prepared by a wet-chemical approach. • Sb-GNP exhibits the well-dispersed Sb nanoparticles anchored on the graphenes. • Sb-GNP shows highly reversible capacities in both Li- and Na-storage. - Abstract: Antimony-graphene nanocomposite (Sb-GNP) was prepared from commercially available graphene nanoplatelets (GNPs) by a simple wet-chemical route at room temperature, and systematically investigated as an anode material for both lithium- and sodium-ion batteries (LIBs and NIBs). The microstructural features of Sb-GNP, and of pure Sb nanoparticles prepared without addition of GNPs, were characterized using X-ray diffraction, field-emission scanning electron microscopy, and high-resolution transmission electron microscopy. The successful formation of a nanocomposite structure was observed for Sb-GNP; the Sb nanoparticles are well dispersed and anchored on graphene nanoplatelets without significant aggregation of Sb nanoparticles, in contrast to the pure Sb nanoparticles. Furthermore, galvanostatic studies revealed that Sb-GNP displays better Li- and Na-storage performance than the pure Sb nanoparticles when utilized as an anode material. The enhanced electrochemical performance can be attributed to the effects of nanocomposite formation with GNPs.

  15. Systematics of spontaneous positron lines

    International Nuclear Information System (INIS)

    Mueller, U.; Reus, T. de; Reinhardt, J.; Mueller, B.; Greiner, W.

    1985-08-01

    Dynamical and spontaneous positron emission are investigated for heavy-ion collisions with long time delay using a semiclassical description. Numerical results and analytical expressions for the characteristic quantities of the resulting spontaneous positron line, i.e., its position, width, and cross section, are compared. The expected behaviour of the line position and cross section and its visibility against the spectrum of dynamically created positrons is discussed in dependence of the united charge Zsub(u) of projectile and target nucleus in a range of systems from Zsub(u)=180 up to Zsub(u)=188. The results are confronted with presently available experimental data, and possible implications on further experiments are worked out. (orig.)

  16. Spontaneous Rotational Inversion in Phycomyces

    KAUST Repository

    Goriely, Alain

    2011-03-01

    The filamentary fungus Phycomyces blakesleeanus undergoes a series of remarkable transitions during aerial growth. During what is known as the stagea IV growth phase, the fungus extends while rotating in a counterclockwise manner when viewed from above (stagea IVa) and then, while continuing to grow, spontaneously reverses to a clockwise rotation (stagea IVb). This phase lasts for 24-48Ah and is sometimes followed by yet another reversal (stageAIVc) before the overall growth ends. Here, we propose a continuum mechanical model of this entire process using nonlinear, anisotropic, elasticity and show how helical anisotropy associated with the cell wall structure can induce spontaneous rotation and, under appropriate circumstances, the observed reversal of rotational handedness. © 2011 American Physical Society.

  17. Spontaneous regression of colon cancer.

    Science.gov (United States)

    Kihara, Kyoichi; Fujita, Shin; Ohshiro, Taihei; Yamamoto, Seiichiro; Sekine, Shigeki

    2015-01-01

    A case of spontaneous regression of transverse colon cancer is reported. A 64-year-old man was diagnosed as having cancer of the transverse colon at a local hospital. Initial and second colonoscopy examinations revealed a typical cancer of the transverse colon, which was diagnosed as moderately differentiated adenocarcinoma. The patient underwent right hemicolectomy 6 weeks after the initial colonoscopy. The resected specimen showed only a scar at the tumor site, and no cancerous tissue was proven histologically. The patient is alive with no evidence of recurrence 1 year after surgery. Although an antitumor immune response is the most likely explanation, the exact nature of the phenomenon was unclear. We describe this rare case and review the literature pertaining to spontaneous regression of colorectal cancer. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Management of intractable spontaneous epistaxis

    Science.gov (United States)

    Rudmik, Luke

    2012-01-01

    Background: Epistaxis is a common otolaryngology emergency and is often controlled with first-line interventions such as cautery, hemostatic agents, or anterior nasal packing. A subset of patients will continue to bleed and require more aggressive therapy. Methods: Intractable spontaneous epistaxis was traditionally managed with posterior nasal packing and prolonged hospital admission. In an effort to reduce patient morbidity and shorten hospital stay, surgical and endovascular techniques have gained popularity. A literature review was conducted. Results: Transnasal endoscopic sphenopalatine artery ligation and arterial embolization provide excellent control rates but the decision to choose one over the other can be challenging. The role of transnasal endoscopic anterior ethmoid artery ligation is unclear but may be considered in certain cases when bleeding localizes to the ethmoid region. Conclusion: This article will focus on the management of intractable spontaneous epistaxis and discuss the role of endoscopic arterial ligation and embolization as it pertains to this challenging clinical scenario. PMID:22391084

  19. Development in Zn4Sb-based thermoelectric materials

    DEFF Research Database (Denmark)

    Yin, Hao

    or thermopower,  the electrical conductivity, the thermal conductivity and T the absolute temperature. The best thermoelectrics are heavily doped semiconductors with high thermoelectric power factors and low thermal conductivities, known as “Phonon Glasses Electrical Crystals”. Zn4Sb3 is one such material......-section. The following part reports the effect of nano-particles on the thermoelectric properties and thermal stability of Zn4Sb3. Though TiO2 nano particles have remarkably enhanced the stability, the thermoelectric performance of all the nano-composites deteriorates. Optimization of the content of the nano...

  20. Magnetic Phase Transitions of CeSb. I

    DEFF Research Database (Denmark)

    Fischer, Pernille Hertz; Lebech, Bente; Meier, G.

    1978-01-01

    The magnetic ordering of the anomalous antiferromagnet CeSb, which has a NaCl crystal structure, was determined in zero applied magnetic field by means of neutron diffraction investigations of single crystals and powder. Below the Neel temperature TN of (16.1+or-0.1)K, there exist six partially...... a first-order phase transition at TN. At approximately TN/2 there is a first-order phase transition to a FCC type IA low-temperature configuration. The unusual magnetic properties of CeSb, which result from anisotropic exchange and crystalline electric field effects, resemble those of certain actinide Na...